ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • Articles  (18)
  • Articles: DFG German National Licenses  (18)
  • Latest Papers from Table of Contents or Articles in Press
  • Bone  (18)
  • Springer  (18)
  • Cambridge University Press
  • Wiley
  • 2010-2014
  • 1990-1994  (18)
  • 1950-1954
  • 1945-1949
  • 1935-1939
  • 1930-1934
  • 2014
  • 2010
  • 1994  (18)
  • 1947
  • 1937
  • Medicine  (18)
  • Ethnic Sciences
  • History
  • Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
  • Architecture, Civil Engineering, Surveying
  • Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
  • Electrical Engineering, Measurement and Control Technology
  • Energy, Environment Protection, Nuclear Power Engineering
Collection
  • Articles  (18)
Source
  • Articles: DFG German National Licenses  (18)
  • Latest Papers from Table of Contents or Articles in Press
Publisher
  • Springer  (18)
  • Cambridge University Press
  • Wiley
Years
  • 2010-2014
  • 1990-1994  (18)
  • 1950-1954
  • 1945-1949
  • 1935-1939
  • +
Year
Topic
  • Medicine  (18)
  • Ethnic Sciences
  • History
  • Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
  • Architecture, Civil Engineering, Surveying
  • +
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 50 (1994), S. 530-535 
    ISSN: 1420-9071
    Keywords: Bone ; collagen ; fulvic acids ; DNA ; ancient DNA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The amount of DNA in ancient bone was determined by ethidium bromide staining after the removal of the potent Taq inhibitor, fulvic acid. A complete decalcification and a perfusion protocol were used to recover DNA from bone. A variety of purification techniques including molecular sieve, hydroxyapatite binding and ‘Magic’ preparations yielded DNA that spanned from 3.4μg/g of bone to below detectable limits. Fulvic acid was shown to interfere with the quantification of DNA derived from ancient human skeletal material one hundred to over seven thousand years old. Scanning UV in the 300 to 230 nm range is a simple and sensitive technique for documenting fulvic acid contamination in ancient bone extracts.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 54 (1994), S. 44-49 
    ISSN: 1432-0827
    Keywords: Bone ; Stress ; Elasticity ; Mechanical properties ; Calcium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract Magnesium (Mg) participates in the normal formation and remodeling of bone. However, little is known about effects of Mg status on the biomechanical function of bone. We examined gross morphometry and composition as well as biomechanical properties of the femurs of male rats fed diets adequate or deficient in Mg. Comparison of deficient animals and controls yielded a number of differences (all significant at P〈0.05). Mg-depleted animals exhibited slow growth, inefficient food utilization, and greatly reduced concentrations of Mg in both serum and femur ash. Compared with controls, femurs from depleted animals were shorter, but wet weights, diameters, and midfemoral cross-sectional areas showed no differences. Bone length was reduced to a greater degree than could be accounted for by differences in body weights between the groups. Bones of Mg-deficient rats contained less dry matter and less ash (which contained more Ca/g) than those of controls, along with a higher percentage of moisture. Significantly reduced bone strength in depleted animals was evident from the lighter loads supported at the elastic limit (yield point) and at fracture and from decreased stresses accompanying those loads. Modulus of elasticity, however, was not affected by Mg depletion. Different yield and breaking loads were related to different body weights of groups, but stresses were reduced for deficient bones even after adjusting for body size. Our data establish abnormal biomechanical behavior of cortical bone in Mg-deficient animals and emphasize the importance of measuring such functional properties of bone in the assessment of responses to altered metabolic conditions under experimental conditions.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 54 (1994), S. 83-86 
    ISSN: 1432-0827
    Keywords: Ultrasound attenuation ; Bone ; Osteoporosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract Ultrasound transmission measurement through the os calcis is an emerging technique and a promising clinical tool for early assessment of osteoporosis. However, several previous studies showed that broadband ultrasonic attenuation (BUA) is sensitive to small variations in bone mass or structure. The os calcis is an inhomogeneous bone and therefore, the attenuation depends on the location in the os calcis. BUA distribution within the os calcis can be measured by rectilinear scanning over the entire bone. We used a mechanical scanning device with both unfocused and focused transducers. The spatial resolution of these was about 25 mm and 4 mm, respectively. There was good agreement (r=0.97) between the results with unfocused and focused transducers. In addition, imaging the variations of BUA is possible with the focused transducers, and high quality images are obtained. These images permit the selection of optimal regions of interest for ultrasound attenuation measurement.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 54 (1994), S. 96-100 
    ISSN: 1432-0827
    Keywords: Bone ; Material quality ; Sound transmission ; Frequency of resonance ; Age ; Bone width
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract In women before and after the age of peak bone mass, identical values of bone mineral density (BMD) can be obtained. However, there is a much higher incidence of osteoporotic fractures in older women. We investigated whether a deterioration of bone material quality with increasing age might contribute to this phenomenon. Material properties of bone tissue can be characterized by the modulus of elasticity, which is correlated to the square of sound transmission velocity. In this study, sound transmission velocity was determined in cortical bone by measuring the frequency of resonance in the ulna in the direction of the bone's longitudinal axis and correcting the values by multiplying by ulna length. Validation of this method indicated acceptable reproducibility: interobserver variability determined as the mean coefficient of variation was 1.82%. In a clinical study, 21 young women (22.5±1.2 years old) were compared with 21 middle-aged women (52.9±2.7 years old). Pairs were matched that had identical values of BMD in the nondominant forearm at a location representing mainly cortical bone (SPA). The product of ulna length and frequency of resonance in the ulna in the younger women was found to be 61.4±5.8 m/second, and in the middle-aged women 55.7±4.5 m/second. The difference was highly significant with P〈0.005. Our results confirm recent findings indicating a deterioration of bone material quality independent of BMD with increasing age. As shown by comparing ulna width at the site of measurement of bone mineral density between both groups of women, the deterioration of bone material quality in ulnar cortical bone with increasing age might at least in part be functionally compensated by an increase of the moment of inertia due to greater bone width [8, 10].
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1432-0827
    Keywords: Helodermin ; Bone ; Cyclic AMP
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract Helodermin and helospectin are peptides structurally similar to vasoactive intestinal polypeptide (VIP) which were recently isolated from the salivary gland venom of the lizard Heloderma suspectum. Pituitary adenylate cyclaseactivating polypeptide (PACAP) has been isolated from ovine hypothalamus and also shows sequence homology to VIP. A helodermin-like peptide has been detected by combined immunohistochemical and immunochemical techniques in the thyroid C-cells. In the present study, lizard helodermin was found to cause a time- and dose-dependent stimulation of cyclic AMP (cAMP) formation in neonatal mouse calvarial bones. Also, helospectin I, PACAP 27, and the C-terminally extended PACAP 38 stimulated cAMP accumulation in the mouse calvariae. The cAMP rise in response to helodermin was comparable to that induced by VIP, both in terms of potency and magnitude of the response. Helodermin, helospectin I, PACAP 27, and PACAP 38, at concentrations of 1 μmol/liter, stimulated cAMP accumulation in enzymatically isolated mouse calvarial bone cells. A significant response to all peptides was observed in both early and late released bone cells isolated from the calvariae, with low and high alkaline phosphatase activity, respectively. Helodermin and VIP stimulated cAMP accumulation in the cloned mouse calvarial osteoblastic cell line MC3T3-E1, in rat (UMR 106-01), and human (Saos-2) osteoblastic osteosarcoma cell lines, but not in the rat osteosarcoma cell line ROS 17/2.8. The effect of helodermin was synergistically and dose-dependently enhanced by forskolin (0.1 and 1 μmol/liter). These data show that bone cells, including osteoblasts, respond to several peptides of the VIP family, including helodermin, helospectin I, PACAP 27, and PACAP 38. Whether the responses are mediated via one or several receptor populations remains to be established. The finding that VIP and helodermin, at maximally effective concentrations, did not cause additive effect on cAMP formation in intact mouse calvariae suggests that these two agonists may use a common receptor.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1432-0827
    Keywords: IL-1α ; IL-1β ; IL-1 receptor antagonist ; Bone ; Calcium ; Parathyroid hormone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract Both interleukin-1α (IL-1α) and interleukin-1β (IL-1β) are powerful stimulators of bone resorption in vivo and in vitro. Interleukin-1 receptor antagonist (IL-1ra) binds to many interleukin-1 receptors. It does not activate the receptor and effectively blocks the action of IL-1α and IL-1β. In this study, human recombinant IL-1ra, at 100-fold excess, was found to block bone resorption in cultured mouse calvaria due to IL-1β but not IL-1α. These observations may be explained by differential affinities of receptors for IL-1α, IL-1β and rhIL-1ra on target bone cells.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 55 (1994), S. 376-380 
    ISSN: 1432-0827
    Keywords: Electromagnetic ; Bone ; Calcium ; Osteoblast
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract Low energy electromagnetic fields (EMF) exhibit a large number of biological effects. A major issue to be determined is “What is the lowest threshold of detection in which cells can respond to an EMF?” In these studies we demonstrate that a low-amplitude combined magnetic field (CMF) which induces a maximum potential gradient of 10-5 V/m is capable of increasing net calcium flux in human osteoblast-like cells. The increase in net calcium flux was frequency dependent, with a peak in the 15.3–16.3 Hz range with an apparent bandwidth of approximately 1 Hz. A model that characterizes the thermal noise limit indicates that nonspherical cell shape, resonant type dynamics, and signal averaging may all play a role in the transduction of lowamplitude EMF effects in biological systems.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 55 (1994), S. 381-386 
    ISSN: 1432-0827
    Keywords: Acoustic microscopy ; Bone ; Collagen fiber ; Elastic anisotropy ; Mineral crystal
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract It has long been thought that collagen fibers within the bone matrix are deposited in an aligned pattern that channels mineral growth. If this model of bone structure is correct, both organic and inorganic phases of bone should have similar elastic anisotropy. Using an acoustic microscope, we measured longitudinal and transverse acoustic velocities of cortical specimens taken from 10 dog femurs before and after removal of either the mineral (using 10% EDTA) or collagen phases (using 7% sodium hypochlorite) and calculated longitudinal (CL) and transverse (CT) elastic coefficients. The anisotropy ratio (CL/CT) decreased significantly after demineralization (1.61 before versus 1.06 after, P〈0.0001, paired t-test). However, there was no significant change after decollagenization (1.51 before versus 1.48 after, P=0.617, paired t-test). We conclude that the orientation of mineral crystals is the primary determinant of bone anisotropy, and the collagen matrix within osteonal bone has little directional orientation.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 54 (1994), S. 34-37 
    ISSN: 1432-0827
    Keywords: Magnesium ; Bone ; Aging ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract The present study was undertaken to reveal the magnesium distribution in human bone. Sixty human ribs, obtained from subjects aged 10–80 years of age, were used. Transverse sections were prepared from the middle region of the human ribs. Adjacent sections were ground to a thickness of about 1000 μm. One section was used for magnesium determination by atomic absorption spectrophotometry, and the other was used for analysis with X-ray microanalysis. Thirty micron thick samples were abraded continuously from the periosteal and the endosteal surfaces by abrasive microsampling, as previously described by Weatherell et al. [3]. Results showed that magnesium concentrations were higher in both the periosteal and endosteal surfaces and did not change with age in general, although it tended to be higher among teenagers and lower over 80 years old.
    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 54 (1994), S. 179-185 
    ISSN: 1432-0827
    Keywords: Bone ; Drugs ; Trabecular ; Turnover ; Computer ; Model ; Sensitivity ; Activation frequency
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract A computer model of trabecular bone turnover has been developed, based on concepts of Jonathan Reeve [1]. This model predicts changes in bone volume by summing bone resorption and formation over a large number of remodeling sites. Clinical data [histomorphometry and bone mineral content (BMC)] from two clinical studies using an antiresorptive drug (etidronate disodium, EHDP) in post-menopausal osteoporosis were used to test the model. The results for BMC obtained from the EHDP and placebo groups in each study at 60 and 120 weeks were correctly predicted by the model from the histomorphometric data obtained from baseline and week 60 biopsies. The parameter in this model having the greatest influence on predicted changes in bone volume was found by sensitivity analysis to be activation frequency. These results suggest that the contribution of bone turnover to BMC can be predicted solely by considering the cell kinetics of the basic multicellular unit (BMU), and that, in the case of antiresorptive drugs, maximal effects on bone volume may be achieved by pharmacological reduction of activation frequency. The results also suggest that the present model may be useful in predicting in clinical studies the effects of EHDP and similar drugs on bone turnover.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 11
    ISSN: 1432-0827
    Keywords: Calcium ; Lactate ; Acidosis ; Treadmill ; Bone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract The purpose of this study was to examine the influence of exercise on the serum concentrations of intact parathyroid hormone (PTH). Serum PTH and plasma lactate were measured in 15 well-trained men, 9 long-distance runners and 6 fire-fighters, during two running exercises. Test one consisted of 40-minute treadmill running with a stepwise increased load and test two consisted of 50-minute treadmill running with a constant velocity. When the load was step-wise increased, the PTH concentrations increased moderately at the slower running paces but reached a final value that was about 50% higher than the starting value. This rise occurred despite a concomitant increase of total serum calcium from 2.38±0.06 to 2.49±0.05 mmol/liter (P〈0.01). During the constant running exercise, the long-distance runners, but not the fire-fighters, displayed a significant increase in PTH concentrations although the rise in total serum calcium was similar in both groups. There was a weak correlation between the changes in PTH and lactate in both exercises. The findings demonstrate that both high and low intensity exercise enhance release of PTH in long-distance runners through a mechanism that does not involve serum calcium. This relationship might be of importance for bone mass in men performing long-distance training.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 12
    ISSN: 1432-0827
    Keywords: Bone ; Diphosphonate ; Osteoporosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract During intermittent cyclical etidronate treatment, a lower extremity pain syndrome associated with stress fractures was observed in three osteoporotic patients. This report describes the development of stress fractures during initial cycles of treatment, with recurrence of symptoms in two patients when etidronate therapy was resumed. Further studies are needed to confirm whether stress fractures are associated with cyclic etidronate treatment and if so, the incidence and pathophysiology need to be determined.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 13
    ISSN: 1432-0827
    Keywords: Pseudohypoparathyroidism ; Thiazide ; Kidney ; Bone ; Parathyroid hormone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract We compared the effect of orally administered 100 mg of hydrochlorothiazide (HCTZ) among eight patients with pseudohypoparathyroidism (PHP) type I, 11 patients with idiopathic hypoparathyroidism (IHP), and 12 patients with primary hyperparathyroidism (1oHPT). Patients with PHP type I or with IHP were studied during the treatment with 1α-hydroxylated metabolites of vitamin D3. HCTZ raised serum levels of calcium (Ca) in 1oHPT (P〈0.001) and PHP type I (P〈0.01) but did not increase urinary excretion of Ca. Serum parathyroid hormone (PTH) in PHP type I decreased (P〈0.02) after HCTZ administration in response to the increase in serum Ca. HCTZ did not raise serum levels of Ca in IHP but increased urinary excretion of Ca in this group (P〈0.01). HCTZ suppressed tubular reabsorption of phosphate (P) in IHP (P〈0.01) and 1oHPT (P〈0.05) but not in PHP type I. Urinary excretion of cAMP did not change after HCTZ administration in PHP type I, IHP, or 1oHPT. Endogenous PTH modulated the effects of HCTZ on Ca mobilization from bone and renal reabsorption of Ca in PHP type I with normal or high serum levels of PTH and in 1oHPT with high serum levels of PTH. The inhibitory effect of HCTZ on renal tubular reabsorption of P (probably from proximal tubules) was independent of PTH. The resistance to this inhibitory effect of HCTZ on P reabsorption in PHP type I suggested a proximal tubular dysfunction in this disorder.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 14
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 55 (1994), S. 230-235 
    ISSN: 1432-0827
    Keywords: Noncollagenous ; Proteins ; Bone ; Sialo-protein ; Osteopontin ; Osteocalcin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract Quantitative analyses of a wide variety of different solvents used for the extraction of several of the noncollagenous proteins of fully mineralized chicken bone powder were carried out to compare both the effectiveness of various procedures and the distribution of specific proteins which were solubilized. Extraction procedures included solutions of 6 M guanidine-HCl, pH 7.0, 0.5 M EDTA, pH 7.4, 0.3 N citric acid, 0.3 N HCl, 0.3 N formic acid, and 0.3 N acetic acid. Chelation of calcium ions by EDTA and dissolution of the mineral phase by acid extraction released 95% or more of the total calcium content of the bone powder by 48 hours, guanidine-HCl released less than 20% or less of the total calcium content even when extraction was carried out by 168 hours. Moreover, although guanidine-HCl solubilized a significant amount of collagen as gelatin, essentially none of the phosphoproteins, osteocalcin, or the proteoglycan decorin were solubilized, as detected by immunological techniques. In contrast, extraction of the mineralized bone powder by HCl and formic acid was very efficient in selectively solubilizing osteocalcin and osteopontin, while bone sialoprotein was selectively released by EDTA, and solubilized to a lesser extent by formic acid. Similarly, EDTA selectively removed decorin compared with HCl, formic, acetic, or citric acids. Only small amounts of osteopontin and osteocalcin were detected in the acetic acid extracts. These results provide methods for the selective solubilization of several different major, noncollagenous proteins from mineralized bone which should significantly aid in maximizing the amount of the specific protein recovered, and the ease with which the various proteins can be purified. The data also provide some insight into the intrinsic solubility characteristics of collaten, the specific noncollagenous proteins, and their potential association with each other and the mineral phase.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 15
    ISSN: 1432-0827
    Keywords: Bone ; Biochemical markers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract The influence of chronic and acute exposure to parathyroid hormone (PTH) on formation and breakdown of type I collagen, using two recently developed radioimmunoassays for serum PICP (the carboxyterminal propeptide of type I procollagen) and serum ICTP (the carboxyterminal telopeptide of type I collagen), have been evaluated. Fasting morning values were obtained from 18 women with primary hyperparathyroidism (HPT) and an equal number of age-matched, healthy controls. A 24-hour infusion of synthetic human parathyroid hormone (PTH 1-38) was performed in 14 healthy females. The patients with HPT had higher values for serum ICTP than the controls (6.0±3.0 and 4.1±2.1 μg/liter; P〈0.05), whereas the serum PICP concentrations were not different (170±72 and 151±65 μg/liter; n.s.). During infusion of PTH in healthy subjects, there was an increase of the serum ICTP concentrations (from 3.6±1.3 to 4.4±1.8 μg/liter; P〈0.001) whereas those of serum PICP decreased (from 185±78 to 118±42 μg/liter; P≤0.0001). The increase of serum ICTP during infusion of PTH was positively related to the increase of serum calcium and other indices of bone resorption, i.e., fasting urinary excretions of hydroxyproline and calcium. The decrease of serum PICP was also related to the changes of serum ICTP and hydroxyproline in urine, serum calcium, and alkaline phosphatase but not to osteocalcin, an established marker of osteoblastic activity. The findings support the fact that serum ICTP is a valuable method for evaluating bone resorption and is also easy to perform. Furthermore, the discordant results for the different markers of osteoblastic activity indicat that they reflect different functions of the cell.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 16
    ISSN: 1432-0878
    Keywords: Bone ; Ossification ; Cartilage ; Matrix ; Chondrocytes ; Complement ; Matrix metalloproteinase ; Immunocytochemistry ; Man
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The first component of complement $$C\bar 1s$$ has been shown to degrade type I and type II collagens (Yamaguchi et al. 1990), the latter of which is a major constituent of the cartilage matrix. In order to understand the physiological roles of $$C\bar 1s$$ in cartilage resorption, the expression of C1s was examined by immunohistochemistry in the primary ossification center where the matrix is removed and replaced by bone marrow. Hypertrophic chondrocytes, endothelium and hematogenous elements in the capillary buds were intensely stained by a monoclonal antibody against C1s. Matrix metalloproteinase 9 (MMP-9, 92kDa gelatinase/type IV collagenase) was also immunolocalized in hypertrophic chondrocytes, mesenchymal cells in the primitive bone marrow and the cartilage matrix adjacent to the marrow. In addition, $$C\bar 1s$$ was found to activate the zymogen of MMP-9. These observations suggest that $$C\bar 1s$$ and MMP-9 coordinately participate in matrix degradation in cartilage.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 17
    Electronic Resource
    Electronic Resource
    Springer
    Annals of biomedical engineering 22 (1994), S. 404-415 
    ISSN: 1573-9686
    Keywords: Bone ; Ultrasound ; Interfacial bonding ; Anisotropy ; Fluoride
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Technology
    Notes: Abstract The mechanical properties of composites are influenced, in part, by the volume fraction, orientation, constituent mechanical properties, and interfacial bonding. Cortical bone tissue represents a short-fibered biological composite where the hydroxyapatite phase is embedded in an organic matrix composed of type I collagen and other noncollagenous proteins. Destructive mechanical testing has revealed that fluoride ion treatment significantly lowers theZ-axis tensile and compressive properties of cortical bone through a constituent interfacial debonding mechanism. The present ultrasonic data indicates that fluoride ion treatment significantly alters the longitudinal velocity in theZ-axis as well as the circumferential and radial axes of cortical bone. This suggests that the distribution of constituents and interfacial bonding amongst them may contribute to the anisotropic nature of bone tissue.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 18
    Electronic Resource
    Electronic Resource
    Springer
    Annals of biomedical engineering 22 (1994), S. 194-201 
    ISSN: 1573-9686
    Keywords: Blood/Fluid flow ; Bone ; Laser ; Material properties
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Technology
    Notes: Abstract This project was undertaken to establish if the integral circulation had any effects upon the mechanical behavior of bone. The influence of blood flow in the rabbit tibia on the strain induced at the bone surface when under load was assessed. Recordings were taken from three adult and three immature New Zealand White rabbits which had previously had both their tibiae pinned with modified orthopedic pins. Strain readings were obtained from the exposed mid-shaft of the tibia of both hind legs before, during and after blood flow changes. The loading was static and used to maintain a strain of 250 μstrain in adult animals and 180 μstrain in immature animals prior to variation in blood flow. The blood flow was altered by means of a tourniquet inflated to 80 mm Hg and placed medial to the pinned tibia; it was inflated for a specific time (≈40 minutes) during the experimental loading. Reducing the blood flow appeared to alter the strain recorded at the bone surface while the applied load across the pins remained constant. An initial effect when there was reduced perfusion was that the strain increased following a reduction in blood flow. The strain then began to decrease in magnitude on the compressive aspect coincident with release of the cuff to a level below the value of the initial normally perfused bone. Upon return of the blood supply to normal levels following the initial hyperaemic phase, the strain value increased to a value comparable with that of normally perfused bone. During the hyperemic phase, found on the compressive aspect of the tibia, the measured strain decreased to a value below the initial loaded strain despite the load remaining constant. This demonstrates that the presence of a normal cardiovascular perfusion actually stiffens the bone while a reduction in perfusion allows the bone to deform more readily for the same external loading.
    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...