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  • Rat  (238)
  • Bone  (222)
  • Chromatographie, Dünnschicht  (138)
  • Neurosecretion  (85)
  • Springer  (673)
  • American Geophysical Union
  • Irkutsk : Ross. Akad. Nauk, Sibirskoe Otd., Inst. Zemnoj Kory
  • Krefeld : Geologischer Dienst Nordhein-Westfalen
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  • 1975-1979  (305)
  • 1970-1974  (368)
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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 27 (1979), S. 177-185 
    ISSN: 1432-0827
    Keywords: Calcification ; Bone ; Glycoprotein ; Golgi ; Osteoblasts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The elaboration of bone matrix glycoprotein by osteoblasts of alveolar bone was investigated by radioautography after the intravenous injection of3H-fucose into young rats. At selected times after injection, animals were sacrificed by intracardiac perfusion and demineralized specimens were prepared for light and electron microscope radioautography. At 5 and 10 min after injection, when the blood fucose level was high, silver grains were restricted to the spheroidal and cylindrical saccules of the Golgi apparatus. At 20 min membrane-limited secretory granules were also labeled. By 35 min, the blood fucose level had dropped and silver grains were detected over the apical cortical cytoplasm, in association with secretory granules located therein. Some grains were present over osteoblast processes and the adjacent prebone matrix. By 4 h most of the silver grains had left the cell. At that time they were observed over prebone, adjacent to osteoblast processes, as well as over the prebone-bone junction where a distinct band of label was noted. In demineralized preparations an electron-dense granular material was present at the prebone-bone junction in association with collagen fibrils. These findings provide evidence that osteoblasts in alveolar bone synthesize fucose-containing glycoprotein and indicate that the addition of3H-fucose occurs in the Golgi apparatus. The glycoprotein passes to the apical cortical cytoplasm by way of membrane-limited secretory granules, is exteriorized, and accumulates at the site where prebone transforms into bone (the prebone-bone junction). Since this is also the site of the calcification front, the deposition of labeled glycoprotein may be related to the deposition of bone mineral.
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  • 2
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    Calcified tissue international 27 (1979), S. 95-99 
    ISSN: 1432-0827
    Keywords: Bone ; Fluoride ; Analysis ; Food ; Age
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Recently published bone fluoride values from Iowa are very high compared to earlier reports, suggesting an increase in fluoride intake. Reanalysis of the Iowa specimens shows levels one-fourth those reported by the Iowa laboratory indicating an error in the original report. Seventeen bone specimens, collected from long-term residents of Rochester, New York, drinking 1 ppm F− water, had a mean value of 2085±270 ppm F− on an ashed-weight basis. This value is not significantly different from that predicted by the data of Zipkin et al. in 1958. These data, therefore, do not support the contention that there has been an increase in fluoride intake.
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  • 3
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    Calcified tissue international 28 (1979), S. 103-105 
    ISSN: 1432-0827
    Keywords: Bone ; Photodensitometry, X-ray ; Radiography ; Spectrophotometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary A conventional spectrophotometer was used to do radiographic photodensitometry of bone mass. An experiment to produce osteoporosis in guinea pigs required quantification of changes in bone mass. Lack of a densitometer necessitated finding another method for quantification. The method developed involved using industrial film in a closed X-ray system. Optical density of X-rays was then read in a spectrophotometer at nine femur locations. Highly significant correlations between optical density and femur calcium content and femur dry weight per millimeter were obtained. Histological sections from an animal with low optical density measurements confirmed bone loss by showing decreased cortical width and loss of trabecular bone. In addition to using readily available equipment, this method offers the advantage of being able to detect bone loss in specific areas of the bones. In addition, bones are left intact and can be used for other purposes.
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  • 4
    ISSN: 1432-0827
    Keywords: ESR ; Bone ; Enamel ; CO3-Apatite ; Paramagnetism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Carbonate-containing hydroxyapatite, enamel, and bone were irradiated by an X-ray and investigated between 77° and 350°K by means of electron spin resonance (ESR) spectroscopy. The ESR spectrum of enamel irradiated at 77°K in vacuum and observed at the same temperature was almost the same as that of the carbonate-containing hydroxyapatite. The temperature dependence of signal intensities confirms a spin-energy exchange between the mineral and organic constituents in bone, but in enamel no or very little spinenergy exchange between the mineral and organic constituents. Considerable similarity among the ESR spectra of enamel, bone, and carbonate-containing apatite was obtained after X-ray irradiation in air at 300°K with both an X-band and a Q-band ESR spectrometer. The Q-band spectrum can be interpreted in terms of two paramagnetic species. One is identified as a CO 3 3− anion radical which has an axial symmetry withg factors of 2.0029 and 1.9972. The other species is found to be centered atg=2.0019.
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  • 5
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    Calcified tissue international 28 (1979), S. 33-36 
    ISSN: 1432-0827
    Keywords: Infrared, visible light ; Bone ; Collagen ; Apatite
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract Photovoltaic effect (infrared and visible light) is observed in bone and its two major components, collagen and apatite, at room temperature. A dimunition in the magnitude of photovoltage is observed after exposure to ultraviolet light in all the cases. The drift mobility of the charge carriers is obtained by measuring I versus V relationships in sandwich samples and relating them to the permitivity of the medium. Lifetime of the injected carriers is measured in the usual way. The data are consistent with the hypothesis that the effects are due to protonic conduction phenomena.
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  • 6
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    Calcified tissue international 27 (1979), S. 161-164 
    ISSN: 1432-0827
    Keywords: Osteoporosis ; Ovary ; Rat ; Vitamin D
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Fifty adult female rats were used to study the effect of 1-alpha-hydroxyvitamin D3 (1α-OH-D3)on bone after oophorectomy. The experimental period was 6 months. At the end of the experiment the femurs and the tibias were investigated for bone mass and composition. Significant signs of osteopenia occurred as a result of oophorectomy. The treatment with 1α-OH-D3 induced only minor changes in blood chemistry but increased bone mass significantly. The findings support the view that 1α-OH-D3 may be a valuable tool in the treatment of osteoporosis resulting from ovarian insufficiency.
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  • 7
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    Calcified tissue international 27 (1979), S. 33-40 
    ISSN: 1432-0827
    Keywords: Chick embryo ; Bone ; Organ culture ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The study describes the ultrastructure of the mineralized portion of chick tibiae from 10 days in ovo to 2 days post-hatch. At 10 days a single mineralized cylinder surrounds the diaphysis. On its outer surface columnar trabeculae join to form ridges parallel to the long axis of the bone. These ridges are covered by another cylinder and form the haversian canals. At 11 days vascular invasion of the marrow cavity occurs and resorption of the endosteal surface begins. This type of periosteal deposition and endosteal resorption is repeated during and subsequent to embryonic development. The mineralized portion of 10-day chick tibiae cultured for 2 days in modified BGJ medium was compared with 10-, 11-, and 12-day tibiae in ovo. Cultured tibiae were similar in length and calcium content to 11-day tibiae in ovo. The form of mineral deposited in ovo and in culture was the same, namely, aggregates of spherical mineral clusters. Differences in culture included the following: (a) few concentric cylinders were deposited as compared with tibiae in ovo; (b) trabeculae were not arranged in rows and ridges in culture; (c) osteocytic lacunae were restricted to bases of trabeculae rather than uniformly distributed as in ovo; and (d) the endosteal surface of tibiae in culture appeared etched.
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  • 8
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    Calcified tissue international 27 (1979), S. 57-64 
    ISSN: 1432-0827
    Keywords: Bone ; Bone formation ; Calcification ; Calcification nodule ; EM
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Osteolathyrism has been used as an experimental model for the study of calcification nodules during the mineralization process. Periosteal exostoses developing in osteolathyrism characteristically have spherical basophilic structures (calcification nodules) in the vicinity of developing bone spicules. In thin sections, the nodules were seen scattered between collagen fibers in the intercellular matrix. Collagen fibers did not appear to be present within the nodules but sometimes were packed just outside them. Matrix vesicles were also present in areas of early mineralization. After EDTA decalcification, the majority of the nodules consisted of a fine granular material surrounded by an electron-dense peripheral zone. The peripheral dense zone was occasionally incomplete in small nodules in areas of early mineralization. An electron-dense central area could be observed in the center of the nodules. Evidence has been presented indicating that the calcification nodules arise from smaller mineralization foci, presumably matrix vesicles. The calcification nodules enlarge to approximately 1.0 µm in size, at which point development is slowed or halted allowing the formation of the peripheral dense zone. Although coalescence of nodules was observed, this was more a random event. The further mineralization of the trabeculae was achieved by the calcification of the collagen fibers. The mineralized trabeculae reflected this pattern of nodular and collagenous calcification. It is suggested that this pattern of calcification is characteristic of rapidly developing woven bone.
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  • 9
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    Calcified tissue international 27 (1979), S. 105-108 
    ISSN: 1432-0827
    Keywords: Bone ; Femur ; Strength ; Density ; Age
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary In order to ascertain whether the intrinsic strength of human bone changes with age or not, we have determined the ultimate tensile strength and density of strips of femoral cortical bone. These femora were collected from cadavers varying in age from 13 to 97 years. The results show that both density and intrinsic strength of bone increase up to about the fourth decade of life and then decrease with age. However, the rate of decrease of strength is greater than that of density. This indicates that the density of bone is not the sole determining factor of its strength, and that some other factors play an important part.
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  • 10
    ISSN: 1432-0827
    Keywords: Bone ; Rickets ; Hypophosphatemia ; Microradiography ; D-resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The perilacunar areas of low mineral density in microradiographs from cortical bone of patients with hypophosphatemic (vitamin D-resistant) rickets are not evenly distributed throughout the bone tissue. Their frequency and distribution were determined in bone from 9 patients with this disease. It was found that the lesion was more frequent in haversian bone than in interstitial bone, and along the inner circumference of growing haversian systems as compared with the outer circumference. These findings indicate that the lesion is the result of retarded mineralization, and that mineralization slowly proceeds in these areas as the bone becomes older. A relatively high frequency of the lesion was also found in osteons with an elliptical cross section along the long axis of the ellipse. The cause of the abundance of the lesion at these sites is not clear, but it is possible to explain the uneven distribution in elliptical osteons by assuming an unequal rate of bone formation in these structures.
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  • 11
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    Calcified tissue international 27 (1979), S. 165-169 
    ISSN: 1432-0827
    Keywords: Oxygen uptake ; Bone ; Oxygen tension ; Carbon dioxide
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The present study was carried out to determine the influence of carbon dioxide and oxygen tension on the respiratory activity of bone cells in mouse calvaria in vitro. Five-day-old mouse calvaria were removed aseptically and incubated individually for 1 h at 37° C in a closed reaction chamber containing 1.5 ml of tissue culture medium made up of 60% horse serum in Gey's solution containing 100 unit/ml penicillin and 100µg/ml streptomycin. Before the calvaria were added, the medium in the incubation chamber was equilibrated with 10%, 20%, 30%, or 50% oxygen balanced with nitrogen. The effect of CO2 on oxygen utilization by the calvaria was determined by incubating the calvaria in a medium previously equilibrated with either 50% O2 balanced with N2 or 50% O2 and 5% CO2 balanced with N2. At each oxygen tension, the rate of oxygen utilization by the calvaria was measured polarographically by a Clark oxygen electrode. The results showed that the rate of oxygen uptake of bone increased as the oxygen tension increased and carbon dioxide stimulated significantly the rate of oxygen utilization by the bone cells. In view of the previous reports that both carbon dioxide and oxygen tension are implicated in the process of bone resorption, it is suggested that these two factors may affect bone resorption by influencing the oxygen utilization by bone cells and ultimately controlling their energy metabolism.
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  • 12
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    Calcified tissue international 28 (1979), S. 37-42 
    ISSN: 1432-0827
    Keywords: X-ray diffraction ; Hydroxyapatite ; Whitlockite ; Fish (Pisces) ; Bone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Pyrolyzed scales, fin spines, and bone from the ray-finned bony fishPolypterus (Actinopterygii) showed two mineral phases on X-ray diffraction: hydroxyapatite (HA), Ca5(PO4)3OH, and whitlockite, Ca3(PO4)2. The ratio of HA/whitlockite varied with the structure (scale, spine, bone) within each individual fish. The relative proportions of HA to whitlockite in pyrolyzed samples reflected the Ca/P ratio of the sample. Whitlockite appears after pyrolysis when the Ca/P is lower than 1.67. Among the five fish investigated, for each structure a general trend was noted. The proportion of HA relative to whitlockite increased with size (age) of the fish. Thus the smallest fish, a juvenile, exhibited a low Ca/P mineral in its calcified tissues, whereas the larger fish had progressively more HA and less whitlockite.
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  • 13
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    Calcified tissue international 28 (1979), S. 17-22 
    ISSN: 1432-0827
    Keywords: Anticonvulsant ; Ketogenic diet ; Calcium ; Vitamin D ; Bone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Vitamin D and mineral metabolism status was examined in five children maintained chronically on combined ketogenic diet-anticonvulsant drug therapy (KG), and the results compared to those obtained in 18 patients treated with anticonvulsant drugs alone (AD) and 15 normal controls. KG patients exhibited biochemical findings of vitamin D deficiency osteomalacia: decreased serum 25-hydroxyvitamin D (25OHD) and calcium concentrations, elevated serum alkaline phosphatase and parathyroid hormone concentrations, decreased urinary calcium and increased urinary hydroxyproline excretion, and decreased bone mass. Although the KG and AD groups demonstrated similar reductions in serum 25OHD concentration, the KG patients exhibited a significantly greater reduction in bone mass. In response to vitamin D supplementation (5000 IU/day), mean bone mass in the KG group increased by 8.1±0.9% (P〈0.001) over a 12-month period. These results suggest that ketogenic diet and anticonvulsant drug therapy have additive deleterious effects on bone mass and that these effects are partially reversible by vitamin D treatment.
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  • 14
    ISSN: 1432-0827
    Keywords: Bone ; Bone cells ; Cyclic AMP ; Osteoclast activating factor ; Lymphokine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Osteoclast activating factor (OAF) is a lymphokine which may participate in the pathologic destruction of bone observed in a number of disorders. In the current studies, we investigated the action of OAF on cAMP accumulation by bones and isolated bone cells in culture. OAF was shown to stimulate accumulation of cAMP in mouse cranial bones at doses between 1 and 1000 ng/ml. Stimulation of bone resorption was observed in bones treated with the same doses of OAF. In order to investigate the cell types responsible for cAMP responses to OAF, we isolated bone cells and grew them in monolayer culture. The cells were isolated by a variety of techniques which separate bone cells into two types of parathyroid hormone (PTH)-responsive populations: (a) cells derived from the periosteal regions of the bone, which also respond to calcitonin with increases in cAMP; and (b) cells derived from the matrix, which do not respond to calcitonin. OAF caused elevation of cAMP levels in both the periosteum-derived cells and the matrix-derived cells. The magnitudes and time courses of OAF effects in these populations resembled the effects previously reported for PTH in the same populations. OAF stimulated adenyl cyclase in both types of cell populations, but did not produce significant changes in cAMP phosphodiesterase activity. OAF differed from PTH in that its effects on cAMP accumulation decreased sharply at supramaximal doses in both bone and isolated cells, especially in the matrix-derived populations. Bone resorption did not decrease as markedly as did cAMP accumulation at high doses of OAF, suggesting that cAMP accumulation and resorption could be dissociated under some conditions. These results indicate that OAF has effects on cAMP production in the same cell populations as PTH, and suggest that OAF could modify not only resorption but also formation of bone in vivo. OAF may exert its effects on bone by means of cAMP-dependent mechanisms, but more data will be necessary to establish this unequivocally. The observed differences between OAF and PTH may be of relevance in the mechanism and treatment of pathologic bone destruction in vivo.
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  • 15
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    Calcified tissue international 27 (1979), S. 199-204 
    ISSN: 1432-0827
    Keywords: Bone ; Parathyroid hormone ; Calcitonin ; Osteoporosis ; Paraplegia ; Hydroxyproline
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary In paraplegia, osteoporosis below the neurological lesion occurs early after the spinal cord affection. The serum levels of parathyroid hormone (PTH) and calcitonin (CT), using a radioimmunoassay for the measurement of immunoreactivity, were studied in 12 paraplegic patients for 9 months following onset. Serum Ca and P levels, urinary hydroxyproline excretion, and the kinetic metabolic clearance of45Ca have also been measured. P and immunoreactive (i) CT levels were found the highest at the beginning of the observation and progressively decreased with time. Ca and iPTH serum levels varied inversely with time, the highest level of Ca and the lowest level of iPTH being recorded at the third month following the paraplegia. Mean values of Ca, iPTH, and iCT were in the normal range throughout the study. P levels were increased during the first 3 months. Hydroxyprolinuria was also high and45Ca kinetics showed increased values of Vt, Vo+, and Vu. These parameters indicate a high degree of bone turnover. The results were consistent with the assumption that PTH is not responsible for the increased resorption of bone in paraplegia. Likewise, a deficiency of CT does not seem to be responsible for this bone resorption. These endocrine modifications could be secondary to an increase in the calcium flux from bone to blood and resulting from bone destruction as attested by the increase of urinary calcium and urinary hydroxyproline excretion.
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  • 16
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    Calcified tissue international 27 (1979), S. 233-237 
    ISSN: 1432-0827
    Keywords: Bone ; Vitamin D ; Acidosis ; Phosphate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Vitamin D and phosphate deficiency were produced in rats in order (a) to evaluate the degree of bone mineral and matrix maturation using a bromoform/toluene density gradient technique; and (b) to compare the aforementioned bone maturational changes due to vitamin D and phosphate deprivation to those produced with superimposed severe acidosis. Rats were fed a diet deficient in vitamin D and phosphorus (0.2%) from 3 weeks through 7 weeks of age. To examine the additional contribution of dietary calcium, we gave one-half of the animals either a low (0.06%) or high (1.3%) calcium diet. Following the 4 weeks of vitamin D deficiency, one-half of each group was given 1.8% NH4Cl in the drinking water for 4 succeeding days to induce an acute, severe acidosis. The degree of bone maturation was quantitated via bromoformtoulene density gradient fractionation; total mineral and hydroxyproline (collagen) levels were quantitated as well. The vitamin D-deficient rats deprived of adequate dietary phosphate responded by conserving phosphorus, and as a consequence total bone phosphorus levels were maintained within that level for control rats. This conservation was independent of calcium intake but was extremely sensitive to acute acid loading, where a significant reduction in total bone phosphorus was noted. The bone maturational profile obtained from the vitamin D-phosphate deficient rats, however, revealed a significant accumulation of less mature or dense bone collagen and mineral with a corresponding decrease in the most mature or dense moieties. In contrast to the reduction of the total bone phosphorus content by acute acidosis, the skeletal collagen-mineral maturational profile was not significantly affected by the short-term systemic acidosis. The observed retardations in the bone collagen and mineral maturation of the vitamin D-deficient, phosphate-deprived state provide an additional observation which may well relate to the progressive osteopenia documented in states of chronic, mild acidosis.
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  • 17
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    Calcified tissue international 27 (1979), S. 275-279 
    ISSN: 1432-0827
    Keywords: Proline ; Cartilage ; Bone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Proline biosynthetic and degradative enzymes are unevenly distributed in differentiated mammalian tissues. Activities of the synthetic enzymes are relatively high in collagenous tissues, whereas activities of the degradative enzymes are high in noncollagenous tissues. In order to further characterize tissue-specific proline biosynthesis and degradation, we have determined proline enzyme activities during cartilage and bone formation induced by demineralized bone matrix. We can thus follow temporal changes in enzyme activity in a single tissue as different cell types develop. Ornithine aminotransferase and pyrroline-5-carboxylate reductase have peaks of activity which correlate with maximal type II collagen synthesis by chondrocytes. Both enzymes also are active during bone formation. In contrast, proline oxidase and pyrroline-5-carboxylate dehydrogenase are present at low levels and do not change as new cell types appear. Arginase activity peaks during the first 3 days and then rapidly decreases by the time cartilage and bone formation begin. These observations further substantiate the importance of proline biosynthesis in collagenous tissues. The close correlation between ornithine aminotransferase activity and type II collagen synthesis suggests that the pathway from ornithine to proline may be especially important during formation of type II collagen.
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  • 18
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    Calcified tissue international 27 (1979), S. 109-115 
    ISSN: 1432-0827
    Keywords: Bone ; Bending rigidity ; Disuse atrophy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The in vivo bending rigidity and bone mineral content of monkey ulnae and tibiae were measured. Bending rigidity in the anteroposterior plane was measured by an impedance probe technique. Forced vibrations of the bones were induced with an electromechanical shaker, and force and velocity at the driving point were determined. The responses over the range of 100–250 Hz were utilized to compute the bending rigidity. Bone mineral content in the cross section was determined by a photon absorption technique. Seventeen male monkeys (Macaca nemestrina) weighing 6–14 kg were evaluated. Repeatability of the rigidity measures was 4%. Bone mineral content was measured with a precision of 3.5%. Bending rigidity was correlated with the mineral content of the cross section,r=0.899. Two monkeys were evaluated during prolonged hypodynamic restraint. Restraint produced regional losses of bone most obviously in the proximal tibia. Local bone mineral content declines 17 to 24% and the average bending rigidity declines 12 to 22%. Changes in bones leading to a reduction in mineral content and stiffness are discussed.
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  • 19
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    Calcified tissue international 27 (1979), S. 13-18 
    ISSN: 1432-0827
    Keywords: Anticonvulsants ; Calcium ; Vitamin D ; Parathyroid hormone ; Bone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Parameters of mineral metabolism were examined in 6 patients with moderately severe anticonvulsant drug-induced osteomalacia. Compared to 15 matched controls, the patients exhibited significantly reduced serum calcium, inorganic phosphate, and 25-hydroxyvitamin D concentration, elevated serum alkaline phosphatase and immunoreactive parathyroid hormone (iPTH) concentration, reduced intestinal47Ca absorption, reduced urinary calcium and increased urinary hydroxyproline excretion, and reduced forearm bone mass. Intestinal absorption of vitamin D3 was normal. Following 4 months of treatment with vitamin D3 (4000 units/day), serum 25-OHD concentration was increased to 3 times mean normal values and all parameters except serum iPTH, urinary calcium excretion, and forearm bone mass were returned to levels not significantly different from normal. Serum iPTH concentration was reduced by 39% (P〈0.05); 24-h urinary calcium excretion rose by 98% (P〈0.001), and forearm bone mass increased by 5.6% (P〈0.05). It is concluded that moderate-dose vitamin D3 supplementation is effective in normalizing parameters of mineral metabolism in this disorder, despite evidence of resistance to the biologic effects of vitamin D.
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  • 20
    ISSN: 1432-0827
    Keywords: Calcium ; PTH ; 1,25(OH)2D ; Acid ; Bone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary We measured mineral and acid balances, serum iPTH, urinary cAMP/creatinine, and plasma concentrations of 25OHD and 1,25(OH)2D in 7 healthy adults during control conditions and during increased fixed acid production achieved either by the administration of NH4Cl (N=3) or by increased dietary protein intake (N=4). When acid production was increased, the subjects were in positive acid balance and negative Ca balance because of increased urinary Ca excretion. Serum iPTH fell slightly but urinary cAMP and the plasma levels of vitamin D metabolites did not change. We conclude that the accelerated skeletal and urinary losses of Ca that occur when fixed acid production is increased are not contributed to nor compensated for by the parathyroid-vitamin D endocrine systems.
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  • 21
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    Calcified tissue international 29 (1979), S. 169-171 
    ISSN: 1432-0827
    Keywords: Glycosaminoglycans ; Bone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Compact bone tissue chondroitin sulphate, previously considered to be pure chondroitin-4-sulphate, was isolated from three adult human femoral diaphyses and digested with chondroitinase ABC. Assaying these digests by means of high performance liquid chromatography we could demonstrate that 12 to 14% of the disaccharide residues were 6-sulphated. The 4/6-ratios were also studied in chondroitin sulphate fractions of different molecular size. Slightly increasing amounts of 6-sulphated disaccharides were found with increasing size of the chondroitin sulphates.
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  • 22
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    Calcified tissue international 29 (1979), S. 7-13 
    ISSN: 1432-0827
    Keywords: Bone ; Culture ; Resorption ; Acidosis ; Alkalosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary We have examined the effects of H+, CO2, and HCO3 − concentrations during metabolic and respiratory acidosis and alkalosis on bone resorption in vitro. Rat fetal bones prelabeled with45CaCl2 were cultured at 2%, 5%, and 10% CO2 for up to 120 h, and the release of45Ca was measured in devitalized bones (non-cell-mediated45Ca release) and in live bones (cell-mediated45Ca release) cultured with or without PTH and 1,25(OH)2D3. Non-cell-mediated mineral loss was linearly related to H+ concentration but not to CO2 or HCO3 − concentration. This effect was observed on both labeled and stable calcium. Over a wide pH range (6.9–7.5) H+, CO2, or HCO3 − concentrations did not influence cell-mediated bone resorption in control or in PTH-and 1,25(OH)2D3-stimulated cultures. However, inhibition of cell-mediated bone resorption was observed at higher or lower pH irrespective of CO2 or HCO3 − concentrations. These observations demonstrate that the bone mineral mobilizing effect of acidosis in vitro is mainly due to the effect of changing H+ concentration on devitalized bone. Effects on cell-mediated bone resorption and hormonal response were observed only at extremes of pH. The effects of H+ were independent of changes in CO2 or HCO3 − concentration and could be responsible for the negative calcium balance and increased urinary loss observed in metabolic acidosis in vivo, but do not explain the reported differences in effects on calcium metabolism between respiratory and metabolic acidosis.
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  • 23
    ISSN: 1432-0878
    Keywords: Catecholamine synthesizing enzymes ; Adrenal medulla ; Embryonic induction ; Adrenocortical hormones ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The cellular localization of the enzymes tyrosine hydroxylase (TH), aromatic amino-acid decarboxylase (or dopa decarboxylase, DDC), dopamine β-hydroxylase (DBH) and phenylethanolamine N-methyltransferase (PNMT) in the adrenal medulla of adult rats and rat fetuses (14th, 17th, 18th, 19th and 21st day) was examined. In the prenatal stages the medullary blastema and an adjacent part of the primitive sympathetic trunk were also investigated. Tissues were fixed in ice-cold 4% paraformaldehyde in 0.1 M phosphate buffer (pH 7.2). Cryostat sections (10 μm in thickness) were stained by the indirect immunofluorescence technique. Rabbit antibodies to TH (isolated from human pheochromocytoma), DDC, DBH and PNMT (the latter three isolated from bovine adrenal medulla) were used. Sections incubated with serum of non-immunized rabbits were used as controls. In the adult adrenal medulla, two cell types can be distinguished. One cell type contains only TH, DDC and DBH. The other cell type contains PNMT in addition. It is concluded that these cells correspond to the noradrenaline-(NA-) and adrenaline-(A-)storing cells respectively. In all prenatal stages TH, DDC and DBH are found in the primitive sympathetic trunk, in the medullary blastema, and in the medullary cells which have migrated into the cortical “anlage”. PNMT is observed for the first time on the 18th day. Moreover, PNMT could only be demonstrated inside the adrenal gland. From these observations it is concluded that the capacity to synthesize NA is developed even before the “medullary” cells have reached the cortical “anlage”. On the contrary, the capacity to synthesize A seems to be acquired only after this contact is established. The hypothesis is put forward that this phenomenon might indicate the induction of PNMT by glucocorticoids secreted by the fetal cortex.
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    Cell & tissue research 200 (1979), S. 135-146 
    ISSN: 1432-0878
    Keywords: Arcuate nucleus ; Cytogenesis ; Synaptogenesis ; Neuropil ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Morphogenesis of the arcuate nucleus of the rat from the 15th fetal day to the 6th postnatal day was investigated light and electron microscopically. The arcuate neurons exhibit a gradual development after the 15th fetal day. All cytoplasmic constituents are present in these nerve cells already during the last days of gestation. Nevertheless, they are not fully differentiated at birth. The first synapse-like structures (presynapses) were observed in 17 day-old, the first synapses in 18 day-old fetuses. During the early postnatal period the number of presynapses decreases, but at the same time there is a gradual increase in the number of the relatively mature synapses. This process starts already during the last days of prenatal life. Although all structural elements of the arcuate nucleus of the adult rat appear to be present at birth, the extent of the neuropil area and the number of the presynapses indicate that the arcuate nucleus is still in a fairly undeveloped stage during the first postnatal days.
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    Cell & tissue research 200 (1979), S. 329-334 
    ISSN: 1432-0878
    Keywords: Median eminence ; Axon terminals ; Tanycytes ; Electron microscopy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The present ultrastructural study proves the existence of nerve terminals closely apposed to the plasmalemmata of tanycytes in the rat median eminence. Several of these “axo-tanycytic” endings display remarkable accumulations of agranular endoplasmic reticulum in the form of pleomorphic vesicles which are closely apposed on either side of the plasma membrane of each cell compartment. Some of these vesicular profiles give the impression of structural continuity across both membrane systems. This phenomenon is discussed in the context of being a potential substratum for communication between both cell compartments.
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  • 26
    ISSN: 1432-0878
    Keywords: Vomeronasal organ ; Membrane particles ; Cell contacts ; Freeze-etching ; Rat
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    Notes: Summary The free surfaces and cell contacts in the epithelia of the vomeronasal organ of the rat were investigated by freeze-etching. The microvilli of receptor cells show a lower density of intramembranous particles (IMP) than the microvilli in the receptor-free epithelium. The ratio between the IMP on P and E-face is approximately 11∶1 in the receptor terminals, and 3.5∶1 in the cilia and microvilli of the receptor-free epithelium. Although atypical in length and only poorly equipped with rootlet fibers, the cilia of the receptor-free epithelium are furnished with typical ciliary necklace structures of up to 10 rows of membrane particles. Differences in the density of IMP on the P-faces of different cilia are probably due to continual ciliogenesis and also due to the different age of cilia in the receptor-free epithelium. Zonulae occludentes show different configurations in the neuroepithelium and in the receptor-free epithelium. In the former, they show a tendency to cross-link and form facet-like patterns, reflecting a constant morphology and relative stability for this apical region. In the receptor-free epithelium the junctional rows of zonulae occludentes display only loosely interconnected networks and a tendency to orient parallel to each other and to the free surface. In addition to zonulae occludentes, typical square aggregations of IMP are observed in the receptor-free epithelium. They are not exclusively restricted to the zone of intensive cell contacts by means of fine interdigitating cell processes, and their function has yet to be identified experimentally.
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    Cell & tissue research 200 (1979), S. 163-177 
    ISSN: 1432-0878
    Keywords: Gastrin cells ; Entero-endocrine cells ; Rat ; Cell isolation ; Pylorus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A technique has been developed to obtain viable, isolated and enriched populations of gastrin cells (G-cells) from the rat stomach. Restricted tissue samples from a small area of the pyloric antrum known to be particularly rich in G-cells, were sequentially digested with pronase followed by mechanical agitation, to remove the epithelial cells. This technique resulted in a significant enrichment of G-cells (3–4 fold) since the surface epithelial cells and upper portions of the glands were discarded before the initial G-cell fraction was collected. These cells in suspension were then isolated from each other by gentle pipetting in a DNase containing solution and designated the crude preparation (CP). The G-cells were then purified further by separating the cells according to size by velocity sedimentation. The greatest concentration of G-cells (15–25 %) was found in the fraction containing cells with diameters of 10 to 12 μm. The effectiveness of the technique was evaluated by counting G-cells as identified by electron microscopy and immunofluorescence and assessing gastrin activity by radioimmunoassay. All three methods indicated that cell separation by gravity velocity sedimentation enriched the G-cell population 15–20 fold over their concentration in the CP. The combined techniques of selective pronase digestion followed by gravity velocity sedimentation resulted in an isolated cell preparation containing a 50–100 fold increase of G-cells over their normal distribution in the intact gastric mucosa. Since these isolated G-cells retain features indicating viability, their usefulness for in vitro studies is suggested.
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    Fresenius' Zeitschrift für analytische Chemie 294 (1979), S. 287-287 
    ISSN: 1618-2650
    Keywords: Nachw. von Carbamatpesticiden in biolog. Material ; Chromatographie, Dünnschicht
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    Fresenius' Zeitschrift für analytische Chemie 294 (1979), S. 361-365 
    ISSN: 1618-2650
    Keywords: Chromatographie, Dünnschicht ; Informationsgehalt und »Äquivokation«
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Summary A method has been developed for the calculation of information contents of one-channel identification procedures, which is especially applicable in the area of thin-layer chromatography (TLC). The method can be considered as a refinement of the one proposed by Massart and can easily be extended to the combination of one-channel procedures. In addition, the quantity ‘equivocation’, which is complementary to the information content, is introduced. As an example the best TLC-systems and the best combinations of two TLC-systems for the identification of DDT and twelve related compounds are selected by using information contents or equivocations. The results for the individual systems are compared with those obtained by Massart.
    Notes: Zusammenfassung Eine Methode zur Berechnung von Informationsgehalten von Einkanal-Identifizierungsverfahren wurde entwickelt, die besonders gut für das Gebiet der Dünnschicht-Chromatographie (DC) anwendbar ist. Sie kann als eine Verfeinerung der von Massart vorgeschlagenen Methode angesehen werden und kann auf einfache Weise für Kombinationen von Einkanal-Verfahren erweitert werden. Dabei wird der Begriff »Äquivokation«, komplementär zum Informationsgehalt, eingeführt. Als Beispiel wurden die besten DC-Systeme und Kombinationen von zwei DC-Systemen für die Identifizierung von DDT und zwölf verwandten Verbindungen unter Benutzung von Informationsgehalten oder »Äquivokationen« ausgewählt. Die Ergebnisse für die einzelnen Systeme werden mit den nach Massart gefundenen verglichen.
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    Fresenius' Zeitschrift für analytische Chemie 294 (1979), S. 407-407 
    ISSN: 1618-2650
    Keywords: Trenn. von Arylbenzolsulfonylthiocarbamiden ; Chromatographie, Dünnschicht
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    Fresenius' Zeitschrift für analytische Chemie 295 (1979), S. 398-401 
    ISSN: 1618-2650
    Keywords: Analyse von pharmazeut. Produkten ; Chromatographie, Dünnschicht ; halogenfreie Fließmittelsysteme
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Mit 2 sauren, 2 basischen und einem neutralen Fließmittel mit unterschiedlichen Polaritäten und guten Trennleistungen konnten 151 von 157 geprüften Arzneisubstanzen mit hRf-Werten zwischen 10 und 90 chromatographiert werden.
    Notes: Summary Using two acidic, two alkaline and a neutral mobile phase of different polarities and high separation efficiencies 151 of 157 tested drug substances could be chromatographed with hRf-values between 10 and 90.
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    Fresenius' Zeitschrift für analytische Chemie 295 (1979), S. 24-29 
    ISSN: 1618-2650
    Keywords: Best. von Polycyclen in Wasser ; Chromatographie, Dünnschicht ; Änderung der Fluorescenzintensität
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Nach der Verordnung über Trinkwasser und Brauchwasser für Lebensmittelbetriebe (Trinkwasserverordnung) vom 31. Januar 1975 müssen 6 Einzelverbindungen aus der Gruppe der polycyclischen aromatischen Kohlenwasserstoffe nachgewiesen werden. Das empfohlene Analysenverfahren basiert auf der Messung der Fluorescenz nach vorangegangener chromatographischer Trennung auf Adsorberschichten. Sowohl bei dieser Trennung als auch in der anschließenden Zeit verändert sich die Fluorescenzintensität einzelner Verbindungen z.T. beträchtlich. Systematische Untersuchungen an Kieselgel und an Mischschichten aus Aluminiumoxid und Acetylcellulose sollen die kritischen Punkte und die möglichen Fehlerquoten offen legen.
    Notes: Summary According to the regulation on the use of drinking and industrial water in food industry (Drinking Water Regulation) of 31 January, 1975, six individual compounds of the group of polycyclic aromatic hydrocarbons must be traced. The analytical procedure recommended is based on the measurement of fluorescence after preceding Chromatographic separation on adsorber layers. In the course of this separation and during the time that follows, the fluorescence intensity of various compounds changes, in some cases considerably. Systematic studies with silica gel and mixed layers of aluminium oxide and acetyl cellulose are intended to reveal critical points and possible ranges of error.
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    Fresenius' Zeitschrift für analytische Chemie 297 (1979), S. 138-143 
    ISSN: 1618-2650
    Keywords: Trenn, der Metallchelate von 8-Mercaptochinolin ; Chromatographie, Dünnschicht
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung 8-Mercaptochinolin (Thiooxin) eignet sich zum Nachweis und zur Trennung von Metallen mit Hilfe der Dünnschicht-Chromatographie. Es bildet Neutralkomplexe definierter Zusammensetzung, die in wäßriger Phase schwerlöslich sind und in Chloroform extrahiert werden können. Fällung und Extraktion sind vom pH-Wert abhängig, wodurch eine Vortrennung der Metalle möglich ist. Beschrieben wird das dünnschicht-chromatographische Verhalten von 17 Metallchelaten. Die intensive Eigenfärbung der Komplexe erübrigt den Gebrauch von Anfärbereagentien. Die visuelle Nachweisgrenze der Metalle liegt zwischen 5 und 20 ng (Fluorescenzlöschung bei 254 nm). Spektralphotometrische Auswertung der Chromatogramme läßt eine Erniedrigung der Nachweisgrenze um etwa eine Zehnerpotenz erwarten.
    Notes: Summary 8-Mercaptoquinoline (thiooxine) is qualified for the detection and separation of metals by thin-layer chromatography. It forms neutral complexes in definite composition, which are insoluble in aqueous solution, but readily soluble in CHCl3. Precipitation and extraction are dependent on the pH value, whereby pre-separation of metals is possible. The thin-layer chromatographic behaviour of 17 metal chelates is described. No spraying is necessary for detection, since the complexes show different, characteristic colours. The visual detection limits of the metals are between 5 and 20 ng (fluorescence quenching at 254 nm). Spectrophotometric determination of the chromatograms lowers the detection limit by one power of ten.
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    Fresenius' Zeitschrift für analytische Chemie 297 (1979), S. 144-147 
    ISSN: 1618-2650
    Keywords: Trenn. der Metallchelate von 1-Hydroxy-2-pyridinthion ; Chromatographie, Dünnschicht
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung 1-Hydroxy-2-pyridinthion (HPT) bildet mit den Metallen der 8. Nebengruppe des Periodensystems intensiv gefärbte Chelatkomplexe. Führt man die Reaktion in wäßriger Phase bei pH 7 aus, so werden alle Elemente der Gruppe erfaßt und als schwerlösliche Neutralkomplexe gefällt. Diese lassen sich mit Chloroform extrahieren und dünnschichtchromatographisch trennen. Die Nachweisgrenze der Metalle liegt zwischen 3 und 40 ng (Fluorescenzlöschung bei 254 nm). Spektralphotometrische Auswertung der Chromatogramme läßt eine Erniedrigung der Nachweisgrenze um eine Zehnerpotenz erwarten.
    Notes: Summary 1-Hydroxy-2-pyridinethione (HPT) forms highly coloured chelate complexes with the metals of the 8th sub-group. If the reaction is carried out in aqueous solution at pH 7, all elements of the group precipitate as insoluble neutral complexes. They can be extracted with CHCl3 and separated by thin-layer chromatography. The detection limit is between 3 and 40 ng (fluorescence quenching at 254 nm). Spectrophotometric determination of the chromatograms lowers the detection limit by one power of ten.
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    Fresenius' Zeitschrift für analytische Chemie 298 (1979), S. 44-44 
    ISSN: 1618-2650
    Keywords: Trenn. von Guanylpyrazolnitraten ; Chromatographie, Dünnschicht
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    Cell & tissue research 200 (1979), S. 29-33 
    ISSN: 1432-0878
    Keywords: Magnocellular neurosecretory system ; Activation ; Rat ; Vasopressinergic neurons ; Oxytocinergic neurons ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The activated hypothalamic magnocellular neurosecretory system of the rat was studied in tissue sections, double stained with the unlabeled antibody peroxidase-antiperoxidase complex (PAP) technique. The results indicate that in animals with an activated hypothalamic magnocellular neuroendocrine system, as well as in normal animals, vasopressin and oxytocin are exclusively synthesized in separate vasopressinergic and oxytocinergic neurons.
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  • 37
    ISSN: 1432-0878
    Keywords: Synaptic contacts ; Neurosecretion ; Lymnaea stagnalis ; Tilting stage electron microscopy ; Serial section reconstruction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the central nervous system (CNS) of the freshwater snail Lymnaea stagnalis 3 types of interneuronal contacts can be distinguished electron-microscopically, viz. true synapses, “synapse-like structures” (SLS), and “spinules”. Use of the electron microscope specimen tilting stage reveals numerous true synapses. Both “terminal” and “en passant” contacts occur on neurones and on glial cells. Furthermore “bigeminal” synapses are present. Complex (combined) convergent and divergent synaptic arrangements are found. On the basis of the morphology of presynaptic vesicles 7 types of true synapses can be discerned. Histochemical data on the contents of the vesicles are lacking. However, vesicle morphology suggests that type IV is aminergic and type VII cholinergic. Terminal and en passant SLS may penetrate deeply into neuronal somata and large axons, and into glial cells. A cluster of synaptic vesicles is present in the presynapse-like element. Spinules (spine-coated “evagination-invagination” specializations of the plasma membranes of 2 adjacent neuronal elements) are observed between somata, between axons, and between soma and axon. The neurosecretory Light Green Cells (LGC) and Caudo-Dorsal Cells (CDC) receive complex synaptic input. Type V true synapses, 2 types of SLS, and spinules contact the LGC. The complex morphology of the relationship between type A SLS and LGC, studied in serial sections, reveals that adjacent glial cells are also contacted by type A SLS. Type II true synapses, 3 types of SLS, and spinules are identified on the CDC. The validity of the methods of identification and classification of interneuronal contacts in the CNS of L. stagnalis, as well as the role of these contacts in the regulation of the activity of “ordinary” neurones, neurosecretory cells, and glial cells is discussed.
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    ISSN: 1432-0878
    Keywords: LH-RH neurons ; Hypothalamus ; Rat ; Immunohistochemistry ; Radioimmunoassay
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    Topics: Biology , Medicine
    Notes: Summary The location of the perikarya of LH-RH neurons in the rat hypothalamus and their pathways to the median eminence were studied by immunohistochemistry and radioimmunoassay after placing stereotaxic electrolytic lesions in several parts of the hypothalamus. The principal location of the cell somata was found to be in the ventral part of the medial preoptic area; their pathways were classified into a main baso-lateral pathway and an accessory descending pathway branching off from the former. The main pathway was found to cross in the vicinity of the corresponding neuronal perikarya. The central median eminence and the dorsal and ventral walls of the tubero-infundibular sulcus of the caudal part of the median eminence are innervated mainly by the baso-lateral pathway. On the other hand, the rostral and most caudal portions of the median eminence are innervated principally by the descending pathway and have a subsidiary dual innervation. The projection of LH-RH neurons to the OVLT is believed to originate from perikarya adjacent to this circumventricular organ.
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    Cell & tissue research 198 (1979), S. 427-433 
    ISSN: 1432-0878
    Keywords: Arcuate nucleus ; Rat ; Hypothalamic deafferentation ; Synaptic plasticity ; Estrogen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In order to examine the effect of estrogen on the synaptic structures in the hypothalamic arcuate nucleus (ARCN), semi-quantitative studies were performed by counting synapses in an 18,000 μm2 area in the middle part of the ARCN in each brain. In ovariectomized female rats injected with 2 μg of estradiol benzoate (EB) for three weeks, the mean numbers of axodendritic and axosomatic synapses were not significantly different from those in the intact and ovariectomized controls. When the medial basal hypothalamus (MBH) including the ARCN was isolated by use of a Halász knife (MBH island), the mean number of axodendritic synapses was decreased to about half of the controls. However, EB treatment for three weeks from the day of surgery effectively restored the axodendritic synaptic population of the deafferented ARCN. This may suggest that estrogen has a facilitatory effect on axodendritic synapse formation in the deafferented ARCN, presumably by stimulating axonal sprouting and synaptic regeneration of intact axons in the MBH island.
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    Cell & tissue research 198 (1979), S. 441-454 
    ISSN: 1432-0878
    Keywords: Testis ; Rat ; Seminiferous tubule ; Transitional zone ; Fine structure
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    Topics: Biology , Medicine
    Notes: Summary An electron microscopic study was made on the structure of the testicular transitional zone (TZ) in the adult rat. The TZ proper consists of modified Sertoli cells, with only a few spermatogonia and macrophages, surrounding distally a very narrow lumen. The TZ Sertoli cells have nuclei with a somewhat coarser matrix and more peripheral heterochromatin than Sertoli cell nuclei of the nearby seminiferous tubules, and the electron density of the cytoplasm varies from cell to cell. Smooth endoplasmic reticulum is abundant, but usually there are also scattered ribosomal rosettes and an occasional profile of rough endoplasmic reticulum. Microtubules are very numerous in the columnar portion of the cell, and laminar structures seemingly joining the cell surfaces are sometimes seen. Lipid droplets and lysosomal structures are frequent cellular components in proximal TZ Sertoli cells. Empty intracellular vacuoles are abundant, sometimes arranged around areas of smooth endoplasmic reticulum. Occasionally, membrane-limited fine granules and vacuoles are seen within Sertoli cells and also in the TZ lumen, suggesting a possible secretory activity by these cells. The apical processes of the Sertoli cells form large vacuolar structures, and in the basal parts of the epithelium vacuoles with capillary-like appearance are frequently seen. Phagocytosis of germinal cells by the Sertoli cells occurs in the proximal region of the TZ. Round waste bodies in contact with the Sertoli cell apices protruding into the tubulus rectus, are also common. The tunica propria of the TZ is thickened and somewhat wrinkled, and in the proximal region the myoid cell layer loses its continuity and is replaced by fibroblasts. The epithelium of the tubulus rectus adjacent to the TZ consists of several overlapping epithelial cells. The typical junctional complexes between TZ Sertoli cells appear to be impermeable to the lanthanum tracer.
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    Cell & tissue research 198 (1979), S. 539-556 
    ISSN: 1432-0878
    Keywords: Neurosecretion ; Ground squirrel (Citellus erythrogenys Brandt) ; Seasonal changes ; Hibernation ; Quantitative analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Monthly observations of the “Gomori-positive” hypothalamo-hypophysial neurosecretory system (HHNS) of the ground squirrel, Citellus erythrogenys Brandt, were carried out light microscopically using several quantitative methods. From the beginning of hibernation, formation of neurosecretory material (NSM) in the neurosecretory cells (NSC) progressively decreases and release of neurohormones from the HHNS is almost fully inhibited. A maximal accumulation of NSM in the perikarya of the NSC and in the posterior pituitary (PP) is found in December. By this time the volume of the cell nuclei and nucleoli is at a minimum. Signs of activation of the HHNS appear and become more conspicuous as the time of arousal from torpor approaches. The amount of NSM in the NSC and the PP decreases simultaneously with the increase in volume of the NSC. Hyperemia and activation of glial elements is visible throughout the HHNS. The morphological signs of activation reach their peak in March. After reproduction is completed (April to beginning of May), the NSC and the PP are almost devoid of NSM. Beginning with June and during the summer and autumn months a progressive accumulation of NSM in the NSC and the PP parallels gradual diminution in the volume of the NSC structures and the glial cells. Mechanisms and effector pathways by which the HHNS influences seasonal adaptation of the organism and reproduction are discussed.
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    Cell & tissue research 199 (1979), S. 483-492 
    ISSN: 1432-0878
    Keywords: Pituitary gland ; Rat ; Luteotroph cells ; Pimozide ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effects of pimozide, a dopamine receptor-blocking agent, were studied in the pars distalis of the rat. The animals received 100μg/100 g pimozide daily for 5, 10, 15, and 20 days. Pimozide induces striking ultrastructural changes after 5 days of treatment. The number of luteotroph (LTH) cells is significantly increased; they display characteristics of stimulation. The extrusion of granules into the intercellular space via exocytosis is frequently observed. The intercellular spaces are highly dilated, forming a lacunar system filled with an amorphous material, erythrocytes and involuted LTH cells. Transitional stages in the process of involution are observed in LTH cells. Luteotroph cells also form a syncytium. Twenty days after treatment the abovedescribed changes decrease in magnitude. The present findings suggest that pimozide stimulates the mechanism of synthesis and release in the luteotroph cells, an effect that is less evident with longer treatment.
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    Cell & tissue research 199 (1979), S. 509-517 
    ISSN: 1432-0878
    Keywords: Olfactory bulb ; Giant cells ; Neurosecretion ; Electron microscopy ; Labyrinth fish
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    Topics: Biology , Medicine
    Notes: Summary The giant cells in the olfactory bulb of labyrinth fish, most likely belonging to the nervus terminalis, show ultrastructural features of active synthesis of secretory material. Dense core vesicles (70–100 nm in diameter), found in the perikaryon as well as in the axon, are the possible storage sites of the secretory substance. Its chemical nature is unknown. In some of these vesicles acid phosphatase is demonstrable. Large membrane-bound bodies (up to 2000 nm in diameter), either containing an electron dense matrix or debris of cytoplasmic organelles, are also acid phosphatase-positive, suggesting their lysosomal nature. Some other ultrastructural characteristics of these cells are also described.
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    ISSN: 1432-0878
    Keywords: Pars distalis ; Graft ; Ultrastructure ; Prolactin ; Rat
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    Topics: Biology , Medicine
    Notes: Summary Intact female rats received transplants of two hypophysial partes distales under the kidney capsule. The plasma levels of prolactin were determined, and the ultrastructure of the grafted gland was studied 15, 45 and 90 days after the operation. Although prolactin levels in the three experimental groups were significantly higher than those in control rats, a decrease in prolactin level was detected in the 45-day samples. Parallel ultrastructural changes suggest that between the 45th and 90th postoperative day a process is initiated leading to hyperplasia and hypertrophy of prolactotrophs.
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    Cell & tissue research 199 (1979), S. 271-279 
    ISSN: 1432-0878
    Keywords: Subsurface cisterns ; Neurons ; Paraventricular nucleus ; Hypothalamus ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Structures identified as subsurface cisterns (SSC's) were found in neurons of the paraventricular nuclei of the rat hypothalamus. They appeared as cytoplasmic organelles consisting most often of stacks of parallel cisterns apposed to the neuronal plasmalemma. These SSC's were located in the interneurons of the parvocellular system, but not in neurosecretory cells and glial cells. SSC's were seen at zones of cytoplasm apposed to neuronal or glial cell processes, showing in some instances specific relationships with synaptic areas. The morphological features of these SSC's are described, and their possible functional significance is briefly discussed.
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    ISSN: 1432-0878
    Keywords: Hypothalamo-hypophysial system ; Rat ; Tanycytes ; Ontogeny
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    Topics: Biology , Medicine
    Notes: Summary The differentiation of tanycytes was studied light and electron microscopically during the perinatal period in rats, the time when functional connections between hypothalamus and hypophysis are established. The 3rd ventricle is slit-like between 16 and 18 days of the prenatal period. Its wall is formed by intensively proliferating matrix cells with apical processes, ovoid perikarya and a basal process. The ventral region of the 3rd ventricle becomes funnel-shaped on the 20th day of the prenatal period. As the cells differentiate, the apical process becomes shorter and broader. Moreover, on day 20 of prenatal life cells without apical processes appear. Their number increases during the postnatal period. The concentration of endoplasmic reticulum, mitochondria, polysomes, lipid droplets, dense bodies (lysosomes), lamellated and multivesicular bodies increases. Initially the cells are similar but from the 3rd day of postnatal life differentiation occurs in different regions of the infundibular recess. After the 5th day, there are no marked changes in the structure and distribution of these cells.
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    Cell & tissue research 201 (1979), S. 377-408 
    ISSN: 1432-0878
    Keywords: Median eminence ; Tanycytes ; Nerve tracts ; Regional organization ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The structural organization of the rostral, lateral and postinfundibular regions of the median eminence (ME) of 5-day cyclic diestrous rats was studied with light and electron microscopic methods. The ependymal cells lining (i) the floor of the infundibular recess (IR) at rostral levels, (ii) the lateral extensions of the IR, and (iii) the floor of the premammillary recess appear to represent the same type of tanycyte ependyma (β1 tanycytes). In the entire width of the rostral and postinfundibular palisade regions, as well as in the lateral palisade region of the preinfundibular ME, the processes of the β1 tanycytes form a continuous cuff. This cuff separates the nerve endings from the blood vessels and the pars tuberalis. At this level, synaptoid contacts between neurosecretory axons and the ependymal cuff can be observed. The ultrastructural characteristics of the β1 tanycytes are described and their ependymal endings tentatively classified into three types. In the lateral regions of the ME, the Golgi study revealed the presence of two fiber systems: (i) one possessing a latero-medial trajectory and distributed in the subependymal region; (ii) the other formed by a loose longitudinal tract originating from neurons of the arcuate nucleus. Some functional implications of the cellular organization of the rat ME are discussed.
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    Cell & tissue research 201 (1979), S. 349-359 
    ISSN: 1432-0878
    Keywords: Hypothalamus ; Rat ; Somatostatin-containing neurons ; Immunocytochemistry
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    Topics: Biology , Medicine
    Notes: Summary The rat hypothalamus was studied at the light microscopic level with the use of single and double immunocytochemical staining methods. It was shown that the rat supraoptic and paraventricular hypothalamic nuclei, and their accessory neurosecretory nuclei, do not contain magnocellular somatostatin neurons. The distribution of the hypothalamic parvocellular somatostatin cells is described. The parvocellular component of the rat hypothalamic paraventricular nucleus is, at least partly, composed of somatostatin cells: they form a fairly well circumscribed periventricular cell mass. The rat suprachiasmatic nuclei contain separate somatostatin neurons and vasopressin neurons. Scattered somatostatin cells are present in the entire arcuate nucleus. In addition to the periventricular somatostatin cells located in the preopticanterior hypothalamic area and in the arcuate nucleus, the rat hypothalamus also contains numerous scattered somatostatin cells located distant from the third ventricle.
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  • 49
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    Cell & tissue research 201 (1979), S. 93-99 
    ISSN: 1432-0878
    Keywords: Pituitary cell ; Gonadotrophs ; Culture ; Cell lines ; Rat
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    Topics: Biology , Medicine
    Notes: Summary Gonadotroph-rich cell lines were established from multipotential pituitary clonal cells (2A8) which were implanted under kidney capsule of hypophysectomized female rats. These cell lines secrete gonadotrophins (FSH and LH) continuously over two months after establishment; LHRH stimulated the secretion of hormones into the culture medium. Many of the cells reacted immunohistochemically to antiserum to FSH or LH, while a small number reacted to antiserum to prolactin or TSH. They did not contain normal secretory granules such as those of gonadotrophs in vivo.
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  • 50
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    Cell & tissue research 201 (1979), S. 499-502 
    ISSN: 1432-0878
    Keywords: Monoamine fluorescence ; Microfluorometry ; Computer-assisted correction ; Hypothalamus ; Rat
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    Topics: Biology , Medicine
    Notes: Summary In a circumscribed area of the preoptic periventricular nucleus of a male rat, formaldehyde-induced monoamine fluorophores modified by treatment with HCl vapors were investigated microfluorometrically (measurement of excitation peak ratio 370∶320 nm) in all fluorescent terminals and preterminals. Microfluorometric recordings of an individual fluorescent structure were performed without UV irradiation of neighboring fluorophores. Recorded data were sampled and corrected by a microcomputer (WangPCS II). 19 neuronal processes (axons) contained noradrenaline fluorophores; 11 contained dopamine fluorophores; 6 exhibited uncharacteristic excitation peak ratios; and in 9 recordings technical problems did not allow identification of the fluorophore content.
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    Cell & tissue research 202 (1979), S. 1-7 
    ISSN: 1432-0878
    Keywords: Matrix vesicles ; Normal bone ; Rat
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    Notes: Summary The occurrence of vesicles in the extracellular matrix of alveolar bone of normal young rats was demonstrated by both ultrastructural and enzymatic studies. Transmission electron microscopy revealed abundant vesicles in the matrix. The presence of hydroxyapatite crystals, both within the vesicles and in the matrix, was affiliated with rupture of the vesicular membrane. Calcifying nodules were scarce. High levels of both specific and total activities of alkalineand pyrophosphatases were found in the fraction of isolated vesicles. This fraction also showed activities of different ATPases and acid phosphatase.
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  • 52
    ISSN: 1432-0878
    Keywords: Median eminence ; Rat ; Serotonin ; Quantitative light and electron microscopic radioautography
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    Notes: Summary Serotonin containing structures in the median eminence of the rat have been studied by quantitative light and electron microscopic radioautography following intraventricular infusion of tritiated 5-hydroxytryptophan. One hour after injection of the tracer the highest density of silver grains was recorded in the ependymal and external zones, especially in the lateral palisade zone. The proportion of labelled neurosecretory terminals was also larger in the lateral palisade zone (29%) as compared with the medial palisade zone (13%), although the mean number of developed silver grains per one terminal was higher in the latter. On the average, 16% of neurosecretory terminals sequestered radiolabelled 5-hydroxytryptophan in the external zone of the rat median eminence. It is suggested that serotonin, like catecholamines, is discharged from neurosecretory terminals localized in the external zone and via the portal circulation affects the function of the anterior pituitary. The sites of origin of serotoninergic structures of the median eminence as well as the possible role of monoamine (catecholamine and indolamine) neurohormones in a dual peptidergic and monoaminergic control of anterior pituitary functions are discussed.
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    Fresenius' Zeitschrift für analytische Chemie 296 (1979), S. 45-45 
    ISSN: 1618-2650
    Keywords: Chromatographie, Dünnschicht ; Diphenylamin als Detektionsmittel
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    Topics: Chemistry and Pharmacology
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    Fresenius' Zeitschrift für analytische Chemie 296 (1979), S. 369-373 
    ISSN: 1618-2650
    Keywords: Chromatographie, Dünnschicht ; vollautomat. Auswertung von Chromatogrammen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Es werden vollautomatische DC-Photometer beschrieben, bei denen ein Rechner die optimale Positionierung der DC-Flecke im Meßspalt steuert. Es lassen sich nicht nur die normalen Meßkurven, sondern auch die gemäß der Kubelka-Munk-Funktion transformierten Kurven für die Auswertung heranziehen. Infolge der Steuerung des Wellenlängenantriebes lassen sich auch Zweiwellenlängentechniken simulieren. Für die Auswertung eignet sich auch die 1. Ableitung der Meßkurve. Die Genauigkeit und Reproduzierbarkeit wird gesondert nach Auftragefehler, Meßfehler, Positionierfehler und Fehler der Chromatographie ausgewiesen.
    Notes: Summary Automated photometers for evaluating TLC plates by an optimized positioning of the spots in respect to the centre of the light beam are described. The evaluation can be performed by using the original measuring curve or a transformed one in respect to the Kubelka-Munk function. Two-wavelength techniques can be simulated, for the monochromator is controlled by the computer. This method has an advantage in measuring not well separated spots. In this case also an evaluation of the first derivative is often successful. The accuracy and reproducibility is given in respect to the different sources of errors: spotting, measurement, positioning and chromatography.
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    Cell & tissue research 197 (1979), S. 443-451 
    ISSN: 1432-0878
    Keywords: Ameloblasts ; Cell death ; Incisors ; Rat
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    Topics: Biology , Medicine
    Notes: Summary The migration of the ameloblasts in the continuously erupting incisors of the rat is accompanied by cell loss. Ameloblasts degenerate near the mesial and lateral cemento-enamel junctions in the secretory zone and in the middle two thirds of the region of postsecretory transition, degeneration being most marked where these areas merge. These findings support the hypothesis that the prism decussation in the enamel results from alternating transverse rows of secretory ameloblasts sliding past each other whilst elaborating their rods. The distribution of the degenerating cells suggests, however, that the sliding cell rows are not exactly transverse but arcuate, with the opening facing incisally. The progress of structural alterations of the nuclei in the degenerating ameloblasts appears to follow the pattern earlier described in vinblastine-damaged ameloblasts.
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    Cell & tissue research 198 (1979), S. 145-158 
    ISSN: 1432-0878
    Keywords: Dorsal prostate gland ; Rat ; Apocrine secretion ; Prolactin
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    Notes: Summary Rat dorsal prostate epithelium was studied in intact adult animals, in animals castrated for three days and in rats after inhibition of prolactin secretion. Thin sections, electron-microscopic autoradiographs and freeze-fracture replicas were used to analyze the process of apocrine secretion in this gland. The rough endoplasmic reticulum and the Golgi apparatus of the secretory cells are well developed, but secretory granules are absent. The only sign indicating release of secretory material is the appearance of blebs originating from the apical plasma membrane. Freeze-fracture replicas of the apical plasma membrane reveal that the blebs develop randomly from the bases of microvilli-like protrusions. In vitro pulse labeling of the proteins using 3H-leucine resulted in a labeling of the apical blebs. A post-castration period of three days was sufficient to reduce drastically the number and size of the apical blebs concomitant with regressive changes of the cell. Suppression of prolactin secretion for three weeks by application of lisuride, a synthetic ergot alkaloid, also induced regressive changes in the secretory cells. The apical blebs were still present, but they were shrunken and their content appeared condensed. These experimental conditions proved that the apical blebs are closely related to the functional activity of the cells and are interpreted as true apocrine secretion in the rat dorsal epithelium.
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    Cell & tissue research 203 (1979), S. 223-229 
    ISSN: 1432-0878
    Keywords: Nuclear inclusions ; Neurons ; Paraventricular nucleus ; Hypothalamus ; Rat
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    Topics: Biology , Medicine
    Notes: Summary This paper deals with the ultrastructure of two types of intranuclear inclusions, “microfilamentous spindle-shaped” and “crystalloid”, present in paraventricular nucleus neurons of adult normal rats. These inclusions appear occasionally in some non-secretory neurons of the parvocellular system, but have never been seen in neurosecretory cells of the magnocellular system. The microfilamentous spindle-shaped inclusions show a close spatial relationship with the granulofibrillar body and interchromatin granules. The distribution and functional significance of such structures are discussed in the light of recent ultrastructural and biochemical studies on nuclear inclusions.
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  • 58
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    Keywords: Neurohemal organ ; Neurosecretion ; Moulting gland ; Ultrastructure ; Crustaceans
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    Topics: Biology , Medicine
    Description / Table of Contents: Résumé Chez Sphaeroma serratum, la mue de puberté est suivie d'une dégénérescence de l'organe Y (glands de mue). Le plexus nerveux céphalique latéral, organe neurohémal accolé à cette glande a été l'objet de la présente étude ultrastructurale. Cet organe représente un centre de stockage de neurosécrétions qui proviennent d'une part, de deux cellules autochtones (cellules plexales) situées au sein même de ce plexus, d'autre part, de cellules neurosécrétrices situées dans le “ganglion mandibulaire” (cellules de type A). Chez les individus pubères, les cellules plexales et les cellules A du ganglion sous-oesophagien synthétisent des granules de neurosécrétion dont la taille est respectivement 1550±50Å et 1570±40Å. Il a été reconnu au sein du plexus 5 catégories de terminaisons dont les granules proviendraient pour deux d'entre elles des cellules plexales et des cellules A du “ganglion mandibulaire”. Chez les animaux pubères on observe un arrêt de la synthèse des granules de neurosécrétion au sein des cellules plexales et des cellules A du “ganglion mandibulaire”. Simultanément on enregistre dans le plexus la raréfaction puis la disparition des divers types de granules. Ce processus atteint en premier les terminaisons correspondant aux cellules plexales et aux cellules A du “ganglion mandibulaire”. La dégénérescence de la glande de mue chez les mâles pourrait être en relation avec l'arrêt de synthèse de ces cellules.
    Notes: Summary The present ultrastructural study deals with the lateral cephalic nerve plexus of Sphaeroma serratum, a neurohemal organ joined to the Y organ (ecdysial gland). This plexus acts as a storage centre for neurosecretory products from two sources: the two autochtonous cells (plexus cells) within the plexus itself, and the neurosecretory cells in various parts of the central nervous system, particulary the “mandibular ganglion” (A-cells). In prepuberal animals, plexus cells and subesophageal A-cells produce neurosecretory granules of two types measuring 1550±50Å and 1570±40Å respectively. Five categories of axon terminals were distinguished in the plexus. The granules found in two of these terminal types are believed to come from the plexus cells and from the “mandibular ganglion” A-cells. Cessation of production of neurosecretory granules in these A cells and plexus cells was observed in puberal animals, in the plexus with concomitant depletion and disappearance of different granule categories. The first axon terminals affected by this process are the two categories containing granules originating in the plexus and “mandibular ganglion” A-cells. Degeneration of the ecdysial gland in male Sphaeroma serratum might be connected with the cessation of granule formation in these two types of cell.
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  • 59
    ISSN: 1432-0878
    Keywords: Median eminence ; Rat ; Catecholamines ; Quantitative light and electron microscopic radioautography
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    Notes: Summary By means of light and electron microscopic radioautography a quantitative study of the regional distribution of catecholamines in the median eminence of the rat was carried out. One hour after intraventricular injection of 3H-dopamine the highest radioautographic reaction was recorded in the external zone, especially in the lateral palisade zone where many neurosecretory terminals are separated from the basal lamina of the portal pericapillary space by a glial “cuff”. This area showed the highest percentage (52%) of labelled catecholamine containing neurosecretory terminals as well as the maximal silver grain density per one terminal. In the medial palisade zone where direct neurovascular contacts with the capillary loops prevail, only 27 per cent of neurosecretory terminals were found to harbour tritiated dopamine. On the average 35 per cent of neurosecretory terminals in the median eminence of the rat contain catecholamines (both dopamine and noradrenaline). Pretreatment of animals with reserpine strongly reduced the binding of the label. Per cent of labelled neurosecretory terminals as well as grain density over terminals were decreased in both the medial and lateral palisade zones, although to a lesser degree in the latter. The site of origin of catecholamine fibers as well as the mode of catecholamine action at the level of the median eminence are discussed.
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    Cell & tissue research 204 (1979), S. 127-140 
    ISSN: 1432-0878
    Keywords: Somatostatin-like activity ; Retina ; Rat
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    Notes: Summary A somatostatin-like substance is demonstrated by light microscopic immunohistochemistry (PAP-method) in perikarya and cell processes of the retina of adult and infant rats. These perikarya are identified according to their size, arrangement and distribution. Each of the first two neuronal orders (receptors, bipolar cells, ganglionic cells) of the visual pathway can be associated with retinal cells reacting positively with anti-somatostatin. In the adult rat, perikarya and processes of (i) horizontal cells, (ii) amacrine cells and (iii) large neurons in the ganglionic layer are specifically labeled. The staining of middle-sized and small ganglion cells is probably caused by the close attachment of labeled fibers to non-reacting cells. Postnatally, the immunoreactive elements develop in parallel to the differentiation of the corresponding retinal layers. It is discussed whether the three types of retinal cells containing a somatostatin-like substance provide an inhibitory system to each of the two orders of retinal neurons.
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    Cell & tissue research 204 (1979), S. 379-385 
    ISSN: 1432-0878
    Keywords: Neurosecretion ; Immunofluorescence ; Crustacea ; X-organ ; Hyperglycemic Hormone
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    Topics: Biology , Medicine
    Notes: Summary Antiserum raised in rabbits against extracts of sinus glands from Carcinus and shown by several criteria to contain antibodies directed against the neurosecretory hyperglycemic hormone was used to locate the hormone-producing perikarya in the optic ganglia. By means of the double antibody fluorescence technique, selective staining of the large neurosecretory perikarya of the medulla terminalis ganglionic X-organ (MTGXO) and their axons is obtained. The axon endings of the sinus gland are also stained. None of the other groups of neurosecretory cells in the eyestalk shows fluorescence. Preabsorption of the antiserum with pure hyperglycemic hormone abolishes the fluorescence.
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    Cell & tissue research 196 (1979), S. 147-151 
    ISSN: 1432-0878
    Keywords: Submaxillary salivary gland ; Secretory granules ; Glycoproteins ; Effect of heat ; Rat
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    Topics: Biology , Medicine
    Notes: Summary Secretory granule area and glycoprotein concentration of the saliva in the submaxillary gland of rats were measured during various stages of acclimation to heat at 34±1° C. Granule size decreased by 18% during the first five days of heat acclimation (0.025〈p〈0.05) after which period it increased to reach 118% of the control levels after 28 days (p〈0.05). Glycoprotein concentration in the saliva of stimulated glands rose above control levels, reaching a maximum between the 2nd and 5th day of acclimation (p〈0.05). It was concluded that the initial decrease in granule size reflects a decrease in glycoprotein content following an increase in salivary flow known to occur at high ambient temperatures. The subsequent increase in granule size is considered an adaptation of the gland to continuous stimulation. The rise in salivary glycoprotein concentration suggests increased efficiency of the secretory mechanism.
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  • 63
    ISSN: 1432-0878
    Keywords: Hypothalamus ; Median eminence ; Intraependymal cisternae ; Rat
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    Notes: Summary Structure, three-dimensional arrangement and ontogeny of large intracellular cisternae located in the median eminence region of the rat hypothalamus were studied using toluidin-blue stained semithin sections and electron microscopy. The cisternae occur along the projections of ependymal cells lining the ventral portion of the third ventricle (infundibular recess). Small cisternae can be seen close to the ventricle, whereas larger ones, divided into smaller compartments by thin septa, cluster near the surface of the hypothalamus. The cisternae are encompassed by a thin layer of cytoplasm to which axon terminals containing synaptic and dense core vesicles are closely related. Cisternae are arranged around the median eminence in a characteristic pattern. They occupy the midline in the retrochiasmatic area, flank both margins of the median eminence and extend caudally behind the origin of the pituitary stalk. The cisternae appear first between the 15th and 17th postnatal days. At about the 30th day their size and distribution resemble the situation observed in adult animals. The ependymal cisternae are suggested to be closely related to the luteinizing-hormone releasing-hormone (LH-RH)-containing fibers.
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    Cell & tissue research 197 (1979), S. 337-346 
    ISSN: 1432-0878
    Keywords: Development ; Median eminence ; Neurohypophysial hormones ; Corticotrophin releasing factor ; Immunoperoxidase histochemistry ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Transverse sections of the median eminence from fetal and neonatal rats were examined by the immunoperoxidase technique to detect the presence of oxytocin, vasopressin and neurophysin. Neurophysin was observed in the 18-day fetus. Vasopressin and oxytocin were not detected until after birth, on the 4th and 8th days respectively. There was an accumulation of material crossreactive with neurophysin and vasopressin antibodies in the palisade layer of the median eminence between the 4th and 9th days after birth. This distribution of immunoreactive material in the palisade layer was suggestive of neurosecretory substances localized in two fibre tracts on either side of the median eminence. The data are consistent with the accumulation of corticotropin releasing factor and an associated neurophysin in this area. It is suggested that the accumulation of material occurs because of the relative immaturity of the capillary loops that constitute the primary plexus of the hypophysial portal system.
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    Cell & tissue research 198 (1979), S. 201-208 
    ISSN: 1432-0878
    Keywords: Neurosecretion ; Corpus cardiacum ; Corpus allatum ; Acheta domesticus
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    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of the corpus cardiacum (CC) and corpus allatum (CA) of the house cricket, Acheta domesticus, is described. Axon profiles within the CC contain neurosecretory granules 160–350 nm in diameter which are indistinguishable from those found in type I neurosecretory cells of the pars intercerebralis and in the nervus corporis cardiaci I. The CC itself contains two cell types: intrinsic neurosecretory cells and glial cells. Intrinsic NSC cytoplasm contains Golgi bodies and electron dense neurosecretory granules 160–350 nm in diameter. Synaptoid configurations with 20–50 nm diameter electron lucent vesicles were observed within axon profiles of the CC. The structure of the CA is relatively uniform with one cell type predominating. Typical CA cells possess large nucleoli, active Golgi complexes, numerous mitochondria, and occassional microtubules. Groups of dark staining cells scattered throughout the CA of some animals were interpreted as evidence of cellular death.
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    Cell & tissue research 196 (1979), S. 237-247 
    ISSN: 1432-0878
    Keywords: Liver ; Kupffer cells ; G6PDH activity ; Histochemistry ; Rat
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    Topics: Biology , Medicine
    Notes: Summary The aim of this study was to identify the G6PDH-active sinusoidal cells in the rat liver described by Rieder et al. (1978). Because of their number and distribution in the liver parenchyma, endothelial cells and pit cells could be excluded. Fat-storing cells were specifically marked by vital staining with vitamin A and identified by fluorescence microscopy. Kupffer cells could be detected after vital staining with carmine. Both staining methods allowed a subsequent incubation for the demonstration of G6PDH activity in the same unfixed cryostat section. Whereas more than 80% of the fluorescent particles were found outside the enzyme-positive cells, all G6PDH-active cells contained carmine particles. After counting the G6PDH-active cells, an estimation of 0.217 × 108 cells/g liver tissue was obtained. The results indicate that high G6PDH activity is common to all Kupffer cells, and is therefore a highly specific marker enzyme for this class of sinusoidal liver cells.
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  • 67
    ISSN: 1432-0878
    Keywords: Neurosecretion ; Hypothalamo-hindbrain pathway ; Rat ; Blood pressure ; Milk ejection
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    Topics: Biology , Medicine
    Notes: Summary 1. In lactating rats and in rats deprived of water, the amount of neurosecretory material in the fibres of the neurosecretory hypothalamohindbrain pathway exceeds that in untreated control animals. Under these experimental conditions the pathway and its target regions can be well analysed by means of fluorescence and electron microscopic methods. 2. The axons belonging to the hypothalamo-hindbrain pathway originate from perikarya located in the caudal portion of the nucleus paraventricularis and also from a small group of perikarya in the caudo-lateral hypothalamus. On the way to the hindbrain the neurosecretory fibres join other fibre bundles of the mid- and hindbrain. 3. In the hindbrain most of the neurosecretory fibres terminate in the area of the nucleus tractus solitarii and in the area of the dorsal column nuclei. The axon terminals form synapses with other neurones. 4. Using cytochemical methods at the ultrastructural level (Naumann and Sterba, 1976), the authors were able to prove that the vesicles in the exohypothalamic fibres and in their synaptic terminals contain the same sort of material as the neurophysin vesicles in the posterior lobe of the hypophysis. 5. The most distinct increase in neurophysin was observed in lactating females which were separated from their sucklings after a normal lactation period of 15 days and killed four days thereafter, and in rats deprived of water for different time periods. 6. The relationship of the neurosecretory hypothalamo-hindbrain pathway to the nucleus tractus solitarii and to the dorsal column nuclei suggests that, functionally, there may be a correlation between the system of blood-pressure control and the milk ejection reflex.
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    Fresenius' Zeitschrift für analytische Chemie 294 (1979), S. 135-139 
    ISSN: 1618-2650
    Keywords: Trenn. von Benzodiazepinen ; Chromatographie, Dünnschicht ; Metaboliten
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Die DC-Trennung von 14 1,4- bzw. 1,5-Benzodiazepinen und 17 Hauptmetaboliten sowie die Detektion mit Bratton-Marshall-, Dragendorff- und Jodoplateat-Reagens werden beschrieben. Rf-Werte sowie die Reaktionen mit den Reagentien sind tabellarisch zusammengestellt und Biotransformationsschemata angegeben.
    Notes: Summary Experimental details for the separation are described and data are compiled for Rf-values and reactions with Bratton-Marshall, Dragendorff and iodoplateate-reagents. Biotransformation schemes for the individual benzodiazepines are presented.
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    Fresenius' Zeitschrift für analytische Chemie 294 (1979), S. 288-288 
    ISSN: 1618-2650
    Keywords: Nachw. von Ioxynil in Biolog. Material ; Chromatographie, Dünnschicht
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    Topics: Chemistry and Pharmacology
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    Fresenius' Zeitschrift für analytische Chemie 295 (1979), S. 263-265 
    ISSN: 1618-2650
    Keywords: Trenn. von Alkoholen ; Chromatographie, Dünnschicht ; C1-C20, 6 Trennsysteme, Dinitrobenzoate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Summary Thin-layer chromatography on rice starch, maize starch, cellulose and talc makes possible the separation of the homologous series of 3,5-dinitrobenzoates of aliphatic alcohols C1 to C20. Six different solvent systems have been employed. Dependence of R f-values on the number of C-atoms on various supports is discussed.
    Notes: Zusammenfassung Mit Hilfe der Dünnschicht-Chromatographie auf Reisstärke, Maisstärke, Cellulose und Talk wurde die homologe Reihe der 3,5-Dinitrobenzoate von aliphatischen Alkoholen C1 bis C20 getrennt. Sechs verschiedene Fließmittel wurden benutzt. Die Abhängigkeit der R f-Werte von der Zahl der C-Atome auf verschiedene Schichten wird diskutiert.
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    Fresenius' Zeitschrift für analytische Chemie 295 (1979), S. 272-272 
    ISSN: 1618-2650
    Keywords: Trenn. von Arylazopyraolen ; Chromatographie, Dünnschicht
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    Fresenius' Zeitschrift für analytische Chemie 294 (1979), S. 36-41 
    ISSN: 1618-2650
    Keywords: Trenn. von Antimikrobiellen Verbindungen ; Chromatographie, Dünnschicht
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Die Trennung und Identifizierung von halogenierten, vorwiegend aliphatischen antimikrobiellen Verbindungen, von Formaldehyd abgebenden Substanzen und von Sulfonsäure-Derivaten auf dünnschicht-chromatographischem Wege wird beschrieben. Die Trennung erfolgt auf einer Kieselgel-Cellulose-Mischschicht mit Äthylacetat/Methanol/10% Ammoniak (65+30+5) als Laufmittel. Zur Sichtbarmachung und zur Identifizierung sind mehrere Sprühmittel notwendig: äthanolischeMethylgelb-Lösung mit anschließender UV-Bestrahlung, Phenylhydrazinsulfonat und Natronlauge sowie Hydroxylamin/Eisen(III)-chlorid und Nitroprussidnatrium-Kaliumhexacyanoferrat (III) u. a. Anhand der verschiedenen Rf-Werte und der Anfärbungen lassen sich die antimikrobiellen Verbindungen rasch und einfach identifizieren.
    Notes: Summary The analysis of halogenated, mainly aliphatic compounds, of formaldehyde donors and of derivatives of sulphonic acid is described. The separation is carried out on plates coated with a mixed layer of silica gel and cellulose and a solvent mixture of ethylacetate/methanol/10% ammonia (65+30+5), whereas for the detection and identification several spray reagents have to be used: ethanolic solution of Methyl Yellow with subsequent UV irradiation, phenylhydrazine-4-sulphonic acid and sodium hydroxide, hydroxylamine/iron(III) chloride, sodium nitroprusside/potassium hexacyanoferrate(III) and others. The Rf-values and the colourations of the spots allow to identify the examined compounds rapidly and without further chemical procedures.
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    Fresenius' Zeitschrift für analytische Chemie 294 (1979), S. 42-42 
    ISSN: 1618-2650
    Keywords: Trenn. von anorg. Ionen ; Chromatographie, Dünnschicht ; DCTA-imprägniert
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    Fresenius' Zeitschrift für analytische Chemie 294 (1979), S. 414-414 
    ISSN: 1618-2650
    Keywords: Identifizierung von Arylhydrazin-benzylsulfonylmethylpyrazolinonen ; Chromatographie, Dünnschicht
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    Fresenius' Zeitschrift für analytische Chemie 299 (1979), S. 207-207 
    ISSN: 1618-2650
    Keywords: Analyse von Sulfonamiden ; Chromatographie, Dünnschicht
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    Medical & biological engineering & computing 17 (1979), S. 471-475 
    ISSN: 1741-0444
    Keywords: Bone ; Strain
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    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Specimens of dry human cortical bone of a disc form were subjected to sinusoidal loading under controlled conditions. The results show a nonlinear increase of the measured peak potential with frequency which reaches a limiting value at about 200 Hz. The analysis, which is based on the circuit representation proposed previously by Shamos, indicates that such a behaviour can be attributed to the measuring circuit parameters. It was found that some relevant results can be interpreted qualitatively by similar analysis.
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    Calcified tissue international 26 (1978), S. 47-49 
    ISSN: 1432-0827
    Keywords: Matrix vesicles ; Calcospherites ; Mineralization ; Bone ; Dentin ; Cartilage ; SEM
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Mineral particle cluster, corresponding to calcospherites or matrix vesicle-initiated clusters in calcifying cartilage and dentin and to collagen bundle-related mineralization in lamellar bone, have been isolated from NaOCl solutions used to dissolve the organic matrix in preparation of anorganic mineralizing fronts for scanning electron microscopy.
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    Calcified tissue international 26 (1978), S. 81-84 
    ISSN: 1432-0827
    Keywords: Osteoclasts ; Bone ; Resorption
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Osteoclastic bone resorption involves the solubilization of the mineral salts and the degradation of noncollagen bone matrix and collagen fibrils. As no recognizable collagen fibrils have ever been reported within cytoplasmic vacuoles in osteoclasts, it is generally assumed that the collagen fibrils are digested extracellularly in the resorption zone. The extent to which lysis occurs extracellularly and whether or not the osteoclasts phagocytose the degradation products remain to be established. In the present communication, a hypothesis is presented suggesting the possibility that osteoclastic resorption of bone involves the participation of two different cell types. According to this hypothesis, osteoclastic bone resorption is initiated by osteoclasts that demineralize areas of bone and degrade noncollagen bone matrix. After the osteoclasts have moved away or become partially detached from the demineralized site, the exposed collagen fibrils are phagocytosed by mononuclear, fibroblast-like or monocyte-derived cells.
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    Calcified tissue international 26 (1978), S. 155-161 
    ISSN: 1432-0827
    Keywords: Plasma protein ; Glycoprotein ; Bone ; Glucosamine
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    Topics: Biology , Medicine , Physics
    Notes: Summary Plasmaα 2HS-glycoprotein is specifically accumulated in calcified tissues. In the present studies this glycoprotein was isolated from plasma and after iodination with iodine-125 was injected intravenously into young rabbits. The tissue distribution and plasma disappearance rate of this radioactively labeled material were determined. Of the various tissues studied, bone showed the greatest retention of labeled glycoprotein expressed as percentage of the injected dose per gram tissue relative to the plasma content. The rate of loss of iodinatedα 2HS-glycoprotein from plasma was similar to that ofα 2HS-glycoprotein labeled endogenously by using14C-glucosamine or3H-glucosamine. The uptake of exogenously labeled3I-α 2HS-glycoprotein into bone tissue expressed as a percentage of the injected dose was similar to that of endogenously labeled14C-α 2HS-glycoprotein. These results suggest that the125I-labeled material can be used to study further the metabolism ofα 2HS-glycoprotein by bone tissue.
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    Calcified tissue international 26 (1978), S. 209-213 
    ISSN: 1432-0827
    Keywords: Mithramycin ; Bone ; β-Glucuronidase ; KT medium
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    Topics: Biology , Medicine , Physics
    Notes: Summary Mithramycin suppresses bone resorption. Its effect on the synthesis and release of β-glucuronidase (a referent for lysosomal enzymes) in mouse calvarial explants was studied in an in vitro culture system. A newly described medium (designated as KT medium) was introduced in this specific study. Mithramycin initially inhibited the release of β-glucuronidase into the medium and resulted in an ultimate accumulation of this enzyme in the bone. These results suggest that inhibition of bone resorption by mithramycin may be attributed to interference in release of lysosomal enzymes from bone cells.
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    Calcified tissue international 25 (1978), S. 37-43 
    ISSN: 1432-0827
    Keywords: ESR ; Radiation free radicals ; CO3-Apatites ; Bone
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    Topics: Biology , Medicine , Physics
    Notes: Summary Exposure of bone mineral to X-rays generates free radicals. These are usually very labile, but can be stabilized at liquid nitrogen temperatures for study by electron spin resonance spectroscopy. The free radicals thus detected in the present study included one with resonances arising from an electron excess center and 2 species with electron-deficit centers: a phosphate anion radical and a radical associated with carbonate. Each of these radicals seemed to be located chiefly at the mineral surface and was sensitive to the surface environment. Presence of an organic phase, as in whole bone, modified free radical production in a manner that suggests interference with the formation of electron deficit centers. Comparison with other synthetic minerals suggests that precipitated carbonateapatites are good models for bone mineral.
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    Calcified tissue international 25 (1978), S. 227-232 
    ISSN: 1432-0827
    Keywords: Parathyroid hormone ; Bone ; Calcium ; Chick embryo ; Organ culture
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    Topics: Biology , Medicine , Physics
    Notes: Summary The purpose of this study was to measure in an in vitro system the movement of Ca and phosphate (Pi) out of bone when treated with parathyroid hormone (PTH). Tibiae from 13-day chick embryos were incubated for up to 8 h in a defined medium containing 1.8 mM Ca. Medium samples were collected every 2 h and were analyzed for Ca, Pi and lactate. Net effluxes from the bones were calculated. When bones were incubated with PTH in the medium (1 U/ml), net Ca efflux was increased 44, 60 and 100% at 4, 6 and 8 h, respectively. At no time was net Pi efflux affected by the hormone. The well known PTH-stimulated lactate production was not seen until 8 h. Lower doses of PTH (0.1 and 0.3 U/ml) were also effective. Comparing PTH (1 U/ml) responsiveness at higher (2.2 mM) and lower (0.9 mM) medium Ca concentrations, showed that with 2.2 mM Ca no increased Ca efflux was seen, while with 0.9 mM Ca significant elevation in medium Ca occurred 2 h sooner than in the experiments using 1.8 mM Ca. In another experiment, varying the medium Pi level from 1 to 2 mM had no effect on the Ca response to PTH. In neither experiment was Pi release affected by PTH. The results of this study have led to the following conclusions: (1) PTH acts on bone to cause an early dose related increase in net Ca efflux; (2) the effect is specific for Ca, since it is not accompanied by an increased Pi efflux, and may be saturated by raising the medium Ca level; and (3) PTH-stimulated Ca efflux in this system is not correlated with, and is probably not a result of increased lactate production.
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    Calcified tissue international 25 (1978), S. 233-240 
    ISSN: 1432-0827
    Keywords: Bone ; Bone resorption ; Albumin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary A fraction (brA), which causes resorption of fetal rat bones in vitro, has been concentrated from bovine serum albumin by anion exchange column chromatography on DEAE Sephadex. This active fraction has also been prepared using DEAE Sephadex A-50 by a batch method with a 0.09M NaCl, 0.1M TRIS buffer, pH 8.35. BrA was 10–30 times more potent than the original albumin. The retained material, which constitutes the bulk of the protein and has less activity than the original albumin, elutes with 0.45M NaCl. Similar treatment of serumα,β or γ globulins does not yield brA. Further enhancement of the bone resorbing activity of brA can be obtained with (NH4)2SO4 fractionation or extraction with CH3OH∶CHCl3. Heating at 55° C for 2 h or at 100° C for 10 min does not affect the activity; overnight incubation with protease destroys the bone resorbing effect. The bone resorbing activity is not removed by dialysis and does not correlate with the protease activity of the fraction. The action of brA is inhibited by 3 mM PO4, 1 μg/ml calcitonin or glucagon, 10−7 M dexamethasone or 0.02 μg/ml actinomycin D. The bone resorbing activity of brA is partially inhibited by 10−7–10−5 M indomethacin. PTH did not elicit bone resorption when added to cultures incubated in chemically defined medium supplemented with 0.1 mg/ml brA. However, brA did not inhibit PTH-induced resorption.
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    Calcified tissue international 25 (1978), S. 249-254 
    ISSN: 1432-0827
    Keywords: Bone ; Oestrogens ; Oestrogen receptors ; Binding proteins
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    Topics: Biology , Medicine , Physics
    Notes: Summary Attempts were made to demonstrate the presence of specific oestrogen binding proteins (“receptors”) in bone cells. High speed cytosol preparations of bone were incubated with several concentrations of radioactive oestradiol alone and with radioactive oestradiol in the presence of a specific antioestrogen, Nafoxidine. Separation of bound and free oestradiol was carried out by dextran coated charcoal treatment and by sucrose gradient ultracentrifugation. Several types of bones likely to be oestrogen-sensitive were investigated: human femoral heads, human phalanx, rat and rabbit calvaria, humeri and femora of female rats. In all experiments we were unable to demonstrate the presence of specific oestrogen receptors in bone cell cytosol indicating that the direct effect of oestrogens on bone, if present, is not mediated by specific oestrogen receptors.
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    Calcified tissue international 25 (1978), S. 75-83 
    ISSN: 1432-0827
    Keywords: Rat ; Fluorosis ; Enamel ; Scanning electron microscopy ; Low temperature incineration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Sixteen 58-day-old male rats of Wistar strain, with a mean body weight of 179 g, were divided into two equal groups. Each group of eight animals was maintained for 70 days on drinking water, ad lib., containing no fluorine (control group) and 100 ppm of fluorine (experimental group). All specimens examined were obtained from the incisal portions of the incisors. The following types of enamel specimens were prepared for scanning electron microscopy: (1) acid-etched specimens; (2) acid-etched specimens followed by low temperature microincineration; and (3) fractured specimens. The enamel formed during high fluoride exposure showed marked hypocalcification, that is, the crystallite density in the prism core and interprismatic region was lower than that of control animals. The organic substances appeared to increase in these regions. These changes were prominent in the outer and middle enamel layers. Such changes following fluoride administration appear to indicate an inhibition of enamel maturation, that is, an inhibition of the mineral deposition and/or an inhibition of organic matrix withdrawal.
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    Calcified tissue international 26 (1978), S. 85-89 
    ISSN: 1432-0827
    Keywords: Bone ; Histology ; Microradiography ; Densitometry ; Computer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary A comparatively simple quantitative method for assessing bone morphology has been evolved. Microradiographs of thin sections of mandible have been scanned with a Joyce-Loebl double beam recording microdensitometer with a scanning autodensidater attachment, using a white beam. For each image the optical densities for all the pixels (picture elements) were divided into 10 groups. The limits of the division were fixed by the maximum and minimum densities occurring within the image. A computer generated map was produced which indicated the spatial distribution of the pixels within each group to which an arbitrarily chosen shading was attached. The number of pixels within each group is also shown on the map. The computer map was compared with the photomicrograph and, where necessary, the original section. The fractional area of hard tissue was then readily determined using the numerical values of each group of pixels.
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    Calcified tissue international 26 (1978), S. 139-142 
    ISSN: 1432-0827
    Keywords: Chemisorption ; Surface area ; Hydroxyapatite ; Bone ; Enamel
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The surface areas of three different samples of hydroxyapatite, samples of deproteinized bone, and samples of whole and deproteinized enamel were determined by adsorption of an adduct (the diglycidyl ether of bisphenol A with N-phenylglycine) from methylene chloride solution. In all cases, the surface areas of these samples agree well with those obtained by the BET (N2) method.
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    Calcified tissue international 25 (1978), S. 105-110 
    ISSN: 1432-0827
    Keywords: Progesterone ; 17β estradiol ; Testosterone ; Tissue culture ; Bone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Although sex steroids are known to affect skeletal metabolism, their effects on bone collagen synthesis have not been studied. We have examined the direct effects of progesterone, 17β estradiol, testosterone, 5α dihydrotestosterone and dehydroepiandrosterone on bone collagen and noncollagen protein synthesis in cultures of calvaria obtained from 21-day fetal rats. Bones were incubated for 24 to 168 h and3H-proline was added for the last 2 h of culture. Incorporation of the label into collagenase-digestible protein (CDP)1 and noncollagen protein (NCP) was determined using repurified bacterial collagenase. Progesterone caused a dose dependent inhibition of the labeling of CDP at concentrations of 3×10−7 M to 10−5 M after 96 h of culture. A smaller inhibitory effect was observed on NCP. The inhibitory effect was slow in onset and persisted when bones were incubated for 48 h with progesterone and then transferred to control medium for 48 h. Progesterone also inhibited the incorporation of3H-thymidine and3H-uridine into fetal rat calvaria. After 24 h of culture, 17β estradiol and testosterone had no effects on the labeling of CDP and NCP. After 96 h, 17β estradiol had a small and inconsistent stimulatory effect on the labeling of CDP but testosterone had no effect. Neither hormone altered the inhibitory effects of parathyroid hormone, cortisol and progesterone. Dihydrotestosterone and dehydroepiandrosterone had no effects after 24 h and 96 h of culture. 17β estradiol, testosterone and dihydrotestosterone did not affect the incorporation of3H-uridine or3H-thymidine into fetal rat calvaria. Our studies indicate that progesterone is an inhibitor of bone collagen synthesis and estrogens and androgens are not major regulators of bone formation in vitro.
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    Calcified tissue international 25 (1978), S. 29-35 
    ISSN: 1432-0827
    Keywords: Albumin ; Bone ; Growth retardation ; Osteomalacia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary 125I-labeled rat albumin injected intravenously into rats was taken up by growing bone. Some of this radioactive albumin could be removed from bone by washing with saline, the proportion so removed decreasing from 82.5% at 1 day to 7.4% at 8 days. Both the total radioactivity, and that remaining in bone after saline wash, were reduced when growth was slowed by alteration or restriction of the diet. Although the amount of125I albumin in rachitic bone was reduced, autoradiography showed that radioactivity was present in rachitic osteoid. Immunoprecipitation using anti-rat-albumin serum showed that about half of the radioactivity released from normal bone by EDTA was still attached to albumin. These results suggest that albumin plays some part in the growth of bone.
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    Fresenius' Zeitschrift für analytische Chemie 292 (1978), S. 381-384 
    ISSN: 1618-2650
    Keywords: Best. von Aminen, aromat. ; Chromatographie, Dünnschicht ; Remissionsmessung
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Es wird eine Methode zur quantitativen Bestimmung von aromatischen Aminen beschrieben. Diese werden dünnschicht-chromatographisch auf Kieselgel 60 F254 Fertigplatten in den Laufmitteln n-Propanol/Methanol/Wasser/Eisessig (65∶15∶15∶20; Vol.) oder n-Butanol/Wasser/Eisessig (66∶17∶17; Vol.) von den Begleitstoffen abgetrennt. Die getrennten Aminflecke werden entweder im Ultraviolett-Bereich oder nach Diazotierung im sichtbaren Bereich mit dem Chromatogramm-Spektralphotometer PMQ II nach der Remissionsmethode gemessen und anhand der auf derselben Platte aufgestellten Eichgerade ausgewertet. Die quantitative Bestimmung wird anhand der beiden Amine 5-Amino-2,4,6-trijod-isophthalsäurebis-(2,3-dihydroxy-propyl-N-methylamid) (I) und 2,4,6-Trijod-3-aminobenzoesäure (II) in Röntgenkontrastmittelpräparaten (RKP) demonstriert. Sowohl im UV- als auch im sichtbaren Bereich, läßt sich in 3000 μg RK-Säure (RKS) noch 0,1 μg freies aromatisches Amin, das sind 0,003%, bezogen auf die eingesetzte Menge RKS, mit einer maximalen relativen Standardabweichung von 4% bestimmen. Diese Methode ist spezifischer und empfindlicher als die der Diazotierung in Lösung.
    Notes: Summary The aromatic amines are separated from impurities by thin-layer chromatography on silica gel 60 F254 precoated plates in the mobile solvents n-propanol/methanol/water/glacial acetic acid (65∶15∶15∶20; vol.) or n-butanol/water/glacial acetic acid (66∶17∶17; vol.). The separated amine spots are measured by the remission method by means of the TLC densitometer PMQ II, either in the u.v. region or, after diazotization, in the visible region, and evaluated on the basis of the linear calibration curve set up on the same plate. Quantitative determination is demonstrated by means of the two amines, 5-amino-2,4,6-triiodoisophthalic acid-bis-(2,3-dihydroxypropyl-N-methylamide) (I) and 2,4,6-triiodo-3-aminobenzoic acid (II), in radiopaque contrast media (RCM). Both in the u.v. and visible regions, it is still possible to determine 0.1 μg of free aromatic amine in 3000 μg of radiopaque contrast medium acid (RCA), or 0.003% in terms of the amount of RCA used, with a maximum relative standard deviation of 4%. This method is more specific and more sensitive than that of diazotization in solution.
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    Fresenius' Zeitschrift für analytische Chemie 293 (1978), S. 135-137 
    ISSN: 1618-2650
    Keywords: Analyse von Desodorantien, Phenolderivaten in Kosmetika ; Chromatographie, Dünnschicht
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Phenolische Desodorantien in kosmetischen Präparaten lassen sich durch Umsetzung mit Echtrotsalz Al (Anthrachinondiazonium-chlorid-1) in wäßrig-alkalischer Lösung, Extraktion des gebildeten Azofarbstoffes mit einem organischen Lösungsmittel und anschließender Dünnschicht-Chromatographie schnell identifizieren. In den meisten Fällen ist die Abhängigkeit zwischen der Extinktion der Farbstofflösung und der eingesetzten Menge des betreffenden Desodorants linear, wodurch dann auch quantitative Bestimmungen möglich sind.
    Notes: Summary Phenolic compounds, used as deodorants in cosmetic products can be identified quickly by reaction with anthraquinonediazonium chloride-1 (Echtrotsalz Al) in aqueous alkaline medium, extraction of the azo dye with an organic solvent and separation by thinlayer chromatography. The relation between the absorbance of the coloured solution and the concentration of the deodorant concerned is generally linear; in these cases quantitative determinations are always possible.
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    Fresenius' Zeitschrift für analytische Chemie 291 (1978), S. 366-368 
    ISSN: 1618-2650
    Keywords: Nachw. von N-Heterocycl. Verbindungen ; Chromatographie, Dünnschicht ; CuSO4-imprägnierte Schichten, Fluorescenz
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Durch die charakteristischen Fluorescenzfarben und die Fluorescenz-Thermochromie der CuJ-Komplexe lassen sich N-Heterocyclen auf Chromatogrammen meist einwandfrei identifizieren. Eine wesentliche Vereinfachung wird durch die Verwendung CuSO4-imprägnierter Kieselgelschichten erreicht. Die Nachweisempfindlichkeiten insbesondere bei tiefer Temperatur ändern sich im Vergleich zur ursprünglichen Technik kaum.
    Notes: Summary N-Heterocycles can usually be identified with certainty through the characteristic fluorescence colours and fluorescence-thermochromism of the CuI-complexes. The use of CuSO4-impregnated silica gel layers facilitates the procedure considerably, and scarcely reduces the sensitivity of detection, particularly at low temperature.
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    Fresenius' Zeitschrift für analytische Chemie 292 (1978), S. 415-416 
    ISSN: 1618-2650
    Keywords: Trenn. von Anorgan. Ionen ; Chromatographie, Dünnschicht ; mit p-Toluidin imprägnierte Schichten
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    Topics: Chemistry and Pharmacology
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    Cell & tissue research 186 (1978), S. 361-374 
    ISSN: 1432-0878
    Keywords: Subfornical organ ; Circumventricular organs ; CSF-contacting neurons ; Encephalo-chromaffin cells ; Neurosecretion ; Rana pipiens
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ventricular surface of the subfornical organ of the frog is made up of ependymal cells with numerous apical microvilli, occasional cytoplasmic protrusions and many vacuoles projecting into the lumen of the third ventricle. Between these cells dendrites of cerebrospinal fluid-contacting neurons reach the ventricle to terminate in bulbous enlargements. In addition, flask-shaped encephalo-chromaffin cells, containing granulated vesicles and aggregates of filaments in their cytoplasm, project into the cerebrospinal fluid. Surrounding the centrally located capillaries are enlarged dendrites and axons of heterogeneous morphology, some of which appear to originate within the subfornical organ, intermingled with dendrites and axons of normal structure. The glial cells in this region, especially the microglial cells, often contain large lipofuscin inclusions, suggestive of degeneration and subsequent phagocytosis of some of the enlarged dendrites and axons. The normally scarce neurosecretory peptidergic axons become more evident and form typical Herring bodies in stalk-transected animals. Neuronal perikarya of varying morphology are predominantly located peripheral to the region of enlarged dendrites and axons. Supraependymal macrophages are particularly numerous on the subfornical organ.
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    Cell & tissue research 189 (1978), S. 155-166 
    ISSN: 1432-0878
    Keywords: Levator ani muscle ; Rat ; Neuromuscular junction ; Castration ; Testosterone effect
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of the neuromuscular junction (n.m.j.) of the androgen-sensitive levator ani muscle was studied in normal adult male rats, in 8-month-old rats castrated at the age of one month and in castrated rats treated with testosterone propionate (TP). Castration does not result in significant changes of the n.m.j. The density of synaptic vesicles and the postsynaptic junctional folds remain practically normal in spite of marked atrophy of the muscle. TP administration for 7 days results in marked changes in preand postsynaptic structures. There is slow progressive depletion of synaptic vesicles, appearance of cisternae and coated vesicles in axon terminals, and coalescence of coated vesicles with the plasma membrane. Coated vesicles are also found inside Schwann cells and among junctional folds. Dense core vesicles appear both in the axon terminals and in the postsynaptic area. Collateral sprouting of terminal axons with the formation of new immature junctions is observed. After 35 days of TP administration depletion of synaptic vesicles continues. Glycogen β-particles, mostly freely dispersed, occasionally seen in axon terminals 7 days after TP administration, subsequently increase in number. In the endplate zone of the muscle fibre increased protein synthesis is indicated by a rapid increase in ribosomes and irregularly located myofilaments and myofibrils. The appearance of n.m.j. after testosterone administration resembles that described after nerve stimulation; the degree of change is however less pronounced.
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  • 96
    ISSN: 1432-0878
    Keywords: α-Endorphin ; Neurosecretion ; Fish pituitary ; Hypothalamohypophyseal relationships ; Immunocytology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A strong positive immunoreaction with an α-endorphin antiserum occurs in two distinct sites of the goldfish and carp neurohypophysis. Fluorescent nerve terminals are found in the laminar nerve processes located in the rostral pars distalis, but the immunocytological reaction is mainly localised on the nerve processes of the posterior neurohypophysis lying between the intermediate lobe cells. Almost all the digitations of the neurohypophysis are strongly fluorescent. The immunoreactive fibres probably originate from the hypothalamus, where perikarya displaying the same immunoreaction have been found in the pars lateralis of the nucleus lateralis tuberis and in some minor centres. The possibility that the immunoreactive substances revealed on the neurohypophyseal processes may originate in the intermediate lobe cells is also discussed. It has now to be established if this hypothalamo-hypophyseal system contains a substance with endorphic properties or only some immunologically related substance devoid of the corresponding physiological activities.
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  • 97
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    Cell & tissue research 189 (1978), S. 277-286 
    ISSN: 1432-0878
    Keywords: Maternal adrenalectomy ; Rat ; Influence on the adrenals of newborn animals ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Maternal adrenalectomy at 7 or 14 days of gestation produced increased cell necrosis within zona reticularis cells on the day of birth and at 24 or 48 h after birth. Small remnants or large portions of adrenocortical cells were present within macrophages. In otherwise normal adrenocortical cells, lipid droplets were incorporated within some mitochondria. Autophagocytosis of single mitochondria was observed within adrenocortical cells. Undoubtedly ultrastructural changes represent stimulation of adrenocortical cells in neonatal rats in response to maternal adrenalectomy.
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  • 98
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    Cell & tissue research 189 (1978), S. 435-440 
    ISSN: 1432-0878
    Keywords: Neurosecretion ; Sinus gland ; Synapses ; Palaemon ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Two types of neurosecretory fibers, designated as Type 5 and Type 6 axons, in the sinus gland of the freshwater prawn, Palaemon, establish contact with other neurosecretory axons by means of synaptic junctions. This finding strongly supports the view that release of some neurohormones from the eyestalk may be regulated by neurosecretory neurons through synaptic transmission.
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  • 99
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    Cell & tissue research 191 (1978), S. 501-506 
    ISSN: 1432-0878
    Keywords: Neurohypophysis ; Ultrastructure ; Perivascular space ; Hormonerelease ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Neural lobes from rats subjected to neurohypophysial hormone-releasing stimuli were examined electron microscopically following fixation in 4 % tannic acid in 2.5 % glutaraldehyde. This fixation allowed the delineation of the perivascular space in the neural lobe tissue. Measurement of the area of the perivascular space showed that it was significantly increased in the rats subjected to vagal stimulation and intraarterial calcium ions compared to the control rats. The rats which had been subjected to haemorrhage as a hormonereleasing stimulus did not show any significant change in the area of the perivascular space. The significance of these findings in relation to hormone release is discussed.
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  • 100
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    Cell & tissue research 191 (1978), S. 507-512 
    ISSN: 1432-0878
    Keywords: Odontoblasts ; Osteoblasts ; Cementoblasts ; Intercellular attachments ; Electron microscopy (SEM/TEM) ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Osteoblasts of the young rat cranium, and cementoblasts and odontoblasts of young rat molars were prepared by ethanol freeze-fracture prior to critical point drying for scanning electron microscopy (SEM) as well as conventional transmission electron microscopy (TEM) techniques. Critical point drying causes shrinkage which separates the lateral intercellular contacts between neighbours in the same sheet in the case of cementoblasts and osteoblasts, but not those between odontoblasts. These differences are considered to be of functional significance and need to be taken into consideration when formulating theories of calcium influx into the mineralizable matrix of the respective tissues.
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