ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Articles  (40)
  • Articles: DFG German National Licenses  (40)
  • Springer  (40)
  • Blackwell Science Ltd
  • 1995-1999  (21)
  • 1980-1984  (19)
  • Biology  (40)
Collection
  • Articles  (40)
Source
Years
Year
  • 1
    ISSN: 1432-1203
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Trisomy 21 human fibroblasts are more sensitive to human interferon-α (IFN-α) than are diploid controls, consistent with the location of the gene (IFRC) which codes for the IFN-α receptor on chromosome 21. When compared in the antiviral assay, the difference in sensitivity is five-to tenfold, much greater then the 50% difference in IFRC gene dosage. An understanding of the mechanism by which this amplification of gene dosage occurs is relevant to the specific pathology of Down's syndrome and as a model system for studying the pathogenic effects of chromosomal aneuploidy. The enzyme (2′–5′) oligoisoadenylate synthetase (2–5A synthetase), which is believed to be central to the interferon-induced antiviral response, is induced 50% more in trisomy 21 fibroblasts than in diploid controls. Thus the amplification in response occurs subsequent to the binding of IFN-α to its receptor and the triggering of the first set of intracellular events, the latter exemplified by the induction of 2–5A synthetase. Similar results were obtained with IFN-γ, consistent with other evidence which indicates that a gene coding for a separate IFN-γ receptor is also located on chromosome 21.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    The journal of membrane biology 75 (1983), S. 105-114 
    ISSN: 1432-1424
    Keywords: shark rectal gland ; ouabain binding ; (Na, K)-ATPase ; cyclic AMP ; slices ; isolated cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary In an attempt to examine the mechanisms of activation of (Na, K)-ATPase when epithelial transport is stimulated, the binding of ouabain to rectal gland tissue was measured before and after stimulation with dibutyryl cAMP and theophylline. Stimulation significantly altered the characteristics of ouabain binding to slices ofSqualus acanthias rectal gland and to isolated rectal gland cells, accelerating the rate of binding and increasing the amount of ouabain bound at equilibrium when low concentrations of ouabain (10−9 to 10−7 m) were present in the medium. Scatchard plots of ouabain binding were nonlinear, suggesting at least two classes of binding sites, one of higher and one of lower affinity. Stimulation with cAMP and theophylline appeared to increase the affinity of the high-affinity site. Ouabain binding was increased by cAMP and theophylline even in the presence of furosemide (10−4 m) or bumetanide (10−5 m), and when Li+ was substituted for Na+, or NO 3 − for Cl−-maneuvers known to inhibit rectal gland secretion. The changes in ouabain binding induced by cAMP and theophylline do not appear, therefore, to be secondary to secretory activity but may reflect a change in the configuration, environment or location of existing enzyme so as to enhance its activity. Stimulation of ouabain binding cannot be demonstrated in whole homogenates of rectal gland, indicating that intact cells are necessary for the cyclic AMP-induced increase in ouabain binding to become manifest.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Journal of comparative physiology 154 (1984), S. 139-144 
    ISSN: 1432-136X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary When the active sodium-potassium pump (Na−K-ATPase) of shark rectal glands is blocked by ouabain, the concentration of intracellular ions changes in the direction of equilibrium with extracellular fluid. These changes were examined when isolated perfused glands were in the basal state and also when they were stimulated to secrete with cAMP and theophylline, to see whether stimulation affected the passive movement of sodium, potassium and chloride across cell membranes. In basal glands 10−4M ouabain induced an increase of 30 meq/l in intracellular [Na+] and a decrease in intracellular [K+] of about 50 meq/l after 30 min, while intracellular [Cl−] was unchanged. In stimulated glands, these movements were exaggerated. The increase in intracellular [Na+] averaged 112 meq/l, and the decrease in intracellular [K+], 96 meq/l (P〈0.01), while mean intracellular [Cl−] rose by 80 meq/l. Furosemide, 10−4M, partially reversed the accelerated changes in intracellular electrolytes seen after ouabain was added to stimulated glands. These results are consistent with an action of cAMP upon a ouabaininsensitive cotransport of sodium, potassium and chloride in the rectal gland, analogous to that described in avian erythrocytes.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Medical & biological engineering & computing 18 (1980), S. 746-748 
    ISSN: 1741-0444
    Keywords: Autozeroing ; Barometric method ; Electronic circuit ; Instrumentation ; Plethysmography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract An electronic circuit is described which automatically rezeroes a physiologic signal whenever it reaches the limit of a display. This modified signal can be used for polygraph monitoring while the raw signal is processed by a wide-range high-resolution a.d. convertor. The device is currently used in conjunction with the barometric method for measuring tidal volume, but should find general use in plethysmography.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1432-0827
    Keywords: 1α25(OH)2D ; Hypercalcemia ; Normocalcemia ; Pulmonary tuberculosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Available evidence indicates that hypercalcemia in pulmonary tuberculosis results from increases in circulating 1α,25-dihydroxyvitamin D [1α,25(OH)2D]. To further characterize vitamin D metabolism in this disorder, the effects of vitamin D, 100,000 units a day for 4 days, were compared in 25 normal subjects and 11 patients with active pulmonary tuberculosis who were normocalcemic and had not had hypercalcemia. Serum calcium, phosphorus, 25-hydroxyvitamin D (25-OHD) and 1α,25(OH)2D were measured. Whereas vitamin D increased mean serum 25-OHD from 20±2 (±SE) to 40±5 ng/ml (P〈0.001) and did not change mean serum 1α,25(OH)2D in the normals (33±2 vs. 31±2 pg/ml), it increased mean serum 25-OHD from 21±4 to 55±13 ng/ml (P〈0.05) and mean serum 1α,25(OH)2D from 28±2 to 35±3 pg/ml (P〈0.05) in the patients. Serum calcium was normal and remained within the normal range in all subjects and patients. The findings indicate that there is a modest but significant abnormality in the regulation of circulating 1α,25(OH)2D in normocalcemic patients with pulmonary tuberculosis. The results are similar to those previously reported by us in normocalcemic patients with sarcoidosis.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1432-0827
    Keywords: Isoproterenol ; Dopamine ; Propranolol ; PTH ; Calcitonin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Available evidencein vitro andin vivo suggests that pharmacologic doses of isoproterenol stimulate the secretion of parathyroid hormone (PTH) and calcitonin (CT) and propranolol inhibits secretion. However, the findings in man are either quite modest or inconsistent. In view of this controversy, we examined the effects of isoproterenol, 0.15 µg intradermally (i.d.), dopamine, 5 µg/kg body weight over 60 min intravenously (i.v.), and propranolol, 1 mg over 5 min followed by 60 µg per min for 2 i.v. in normal human subjects. It was found that these agents did not alter serum calcium, serum immunoreactive PTH, or plasma immunoreactive CT. The findings do not support a physiologic role for biogenic amines in the control and regulation of PTH or CT secretion in normal man.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1432-0827
    Keywords: Key words: Cytokines — Bone mineral density — Premenopausal — Interleukin-1 — Interleukin-6 — Tumor necrosis factor.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract. Cytokines such as interleukin-1 (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor (TNF-α) can influence both bone resorption and bone formation. The objective of this cross-sectional study was to examine the relationship between cytokine production by peripheral blood mononuclear cells (PBMC) and bone mineral density (BMD); the annual rate of change in BMD was examined. Subjects participating in a randomized clinical trial entitled the Women's Healthy Lifestyle Project in Allegheny County, Pennsylvania were used. They included 50 healthy premenopausal women, aged 45–52 years, who had regular menses within the past 3 months and were not on replacement estrogens. Dual-energy X-ray absorptiometry measurements at the AP lumbar spine and femoral neck were made at baseline and at the first annual exam using a Hologic QDR 2000 densitometer. Cytokine production of IL-1β, IL-6, and TNF-α by PBMC was measured at the annual exam. The median values for stimulated cytokine production by PBMC were 3.92 ng/ml, 31.3 ng/ml, and 1.05 ng/ml, for IL-1β, IL-6, and TNF-α, respectively. There were modest correlations between cytokine production and cross-sectional BMD, ranging from r =−0.30 to r =−0.13. Trends of greater spinal bone loss were observed in women with ``high'' (≥75th percentile) cytokine production of stimulated IL-1β and IL-6 (IL-1β: ``high'' =−1.56% ± 0.70 versus ``low'' (〈75th percentile) =−0.56% ± 0.35, P= 0.21). In contrast, greater annual gains in femoral neck BMD were observed in those with high cytokine production of IL-1β and IL-6 (IL-1β: high = 3.39% ± 1.16 versus low =−0.85 ± 0.58, P= 0.002). There was no association between stimulated TNF production and annual change in BMD. In this population of healthy premenopausal women, the relationship between cytokine production by PBMC and the rate of change in BMD was significantly different for the lumbar spine and femoral neck, possibly reflecting differences in the proportion of trabecular and cortical bone at these sites.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1432-0975
    Keywords: Key words Coral Breakage ; Conservation ; Marine Protected Area ; Partial Mortality ; Reef Management ; Stylophora pistillata
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences
    Notes: Abstract  A small-scale, “no-use zone policy” has been implemented since 1992 at Eilat’s Coral Nature Reserve (Northern Red Sea). Six years later, the status of this closed-to-the-public reef area was compared to two nearby open-to-the-public sites, by evaluating populations of the scleractinian coral Stylophora pistillata in the strolling zone (0.5–1.5 m depth). Results from the open sites show that: (1) Live coral cover was three times lower than at the closed site; (2) numbers of small colonies (recruits) were significantly higher than in the closed site, while numbers of medium and large size colonies (geometric mean radius, r¯〉4.1 cm) per m2 were significantly lower; (3) maximum r¯ was almost half than that in the closed site (9.6 cm versus 16.7 cm); (4) average number of broken colonies was three times higher than in the closed site; (5) significantly fewer colonies were partially dead. The latter result may reflect senescence processes in the large colonies of the closed site. Although colony breakage is reduced, it appears that the “no-use zone” policy is not sufficient for protecting small reef areas. The intense exploitation of Eilat’s coral reef by the tourist industry requires’ in addition to the conventional protective measures, the initiation of novel management solutions such as reef restoration by sexual and asexual recruits.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1432-0827
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 56 (1995), S. 83-87 
    ISSN: 1432-0827
    Keywords: Immunoradiometric assay ; Parathyroid hormone ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract Measurement of parathyroid hormone (PTH) in the rat is most often performed with competitive ligand radioimmunoassays (RIA) utilizing heterologous antibodies. We report here the validation of a newly developed homologous immunoradiometric assay (IRMA) for rat PTH. Two different goat antibodies to the amino-terminal sequence of rat PTH are utilized; one is immobilized onto plastic beads to capture the PTH molecules and the other is radiolabeled for detection. To test this new IRMA, 30 Sprague-Dawley rats were randomized into three treatment groups to receive by intraperitoneal injection: (1) saline 1 ml/kg (control); (2) calcium chloride 40 mg/kg (hypercalcemic); and (3) EDTA 300 mg/kg (hypocalcemic). Blood samples were taken at 0, 30, 60, 180, and 300 minutes after administration of the assigned treatment for measurement of ionized calcium (Ca2+) and serum PTH. Most of the variance in PTH levels was found to be due to changes in Ca2+ (r2=0.780, P〈0.0001). There was also a close temporal relationship between the two, with the highest levels of PTH occurring at the same measured time points as the lowest Ca2+, and vice versa. The measured detection limit of the IRMA was 3 pg/ml with intra-and interassay coefficients of variation of 1.74% and 3.07%, respectively. Serial dilutions with pooled rat serum, synthetic rat PTH-(1–34), and synthetic human PTH-(1–34) showed good parallelism with increased specificity for the pooled and synthetic PTH, despite a degree of crossreactivity with hPTH. The assay is able to quantitate rapid changes in PTH, providing all the advantages of IRMA methodology including technical simplicity and speed of performance, and is likely to become a useful tool in investigations of bone, mineral, and renal homeostasis using the rat.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...