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  • 1975-1979  (148)
  • 1965-1969  (70)
  • 1920-1924
  • 1840-1849
  • Bone
  • Insulin
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Skeletal radiology 4 (1979), S. 72-78 
    ISSN: 1432-2161
    Keywords: Sarcomas ; Bone ; Neoplasms ; Radiation induced
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Historically, the literature reveals that the incidence of radiation induced bone sarcomas is very low. Details related to epidemiology cannot be identified, however, because of the difficulty of identifying precisely the patient population at risk for development of the radiation induced sarcoma. The change in character of practice in cancer management with ever increasing numbers of patients receiving both radiation therapy and chemotherapy should alert physicians to the potential for increased incidence of this rare and unusual tumor.
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  • 2
    ISSN: 1432-2013
    Keywords: Adrenergic innervation ; Endocrine pancreas ; Insulin ; Exercise ; Glucagon
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The normal depression of plasma insulin concentration during exercise has been ascribed to adrenergic inhibition of insulin release and the role of humoral catecholamines in this hormonal adjustment has repeatedly been stressed. In the present study this contention has been investigated in 6 bilaterally adrenalectomized patients and in 6 sex- and age-matched controls who undertook exercise on an ergometer until they were exhausted. No differences were observed in any cardiovascular or metabolic adjustments between the two groups during strenous exercise. Mean plasma insulin concentration fell by about 50% in both groups. Phentolamine effectively abolished the fall in plasma insulin concentration during exercise in 2 adrenalectomized patients. The results suggest that the adrenergic nerves that supply the B-cells have a functional role in man during exercise.
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  • 3
    ISSN: 1432-1440
    Keywords: Papillary muscle ; Hypoxia ; Glucose ; Insulin ; Force of contraction ; Papillarmuskel ; Kontraktionskraft ; Hypoxie ; Glucose ; Insulin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die minimal verbleibende Kontraktionskraft unter dem Einfluß von Hypoxie wurde an isolierten, rechtsventrikulären Papillarmuskeln (Meerschweinchen) gemessen, die kurzdauernd (90 s) mit hypoxischem (pO2 90 mm Hg) statt oxygeniertem (pO2 630 mm Hg) Medium inkubiert wurden. Unter dem Einfluß von Insulin (0,05 IE/ml) bei erhöhter Glucosekonzentration (300 mg% im Vergleich mit 100 mg%) sank die Kontraktionskraft minimal nur auf 70±9% im Vergleich mit 38±11% des Ausgangswertes (Kontrolle,p〈0,001). Eine alleinige Erhöhung der Glucosekonzentration oder Zugabe von Insulin hatte geringere Effekte zur Folge. Diese Befunde dokumentieren eine erhebliche Steigerung der Hypoxietoleranz des Myokards durch Glucose-Insulin.
    Notes: Summary The minimally remaining force of contraction under the influence of hypoxia was measured in isolated right-ventricular papillary muscles of the guinea-pig, incubated in hypoxic (pO2 90 mm Hg) and oxygenated (pO2 630 mm Hg) buffer solution. With insulin (0.05 IE/ml) and elevated glucose (300 mg% compared to 100 mg%) the force of contraction fell to only 70±9% minimally instead of 38±11% (control,p〈0,001). Elevated glucose or insulin alone had less pronounced effects which were not statistically significant for insulin. The results show an increase of tolerance against hypoxia of isolated papillary muscles under the influence of glucose and insulin.
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    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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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    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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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    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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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    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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  • 8
    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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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    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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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    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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  • 11
    Electronic Resource
    Electronic Resource
    Springer
    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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  • 12
    Electronic Resource
    Electronic Resource
    Springer
    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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  • 13
    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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  • 14
    Electronic Resource
    Electronic Resource
    Springer
    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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  • 15
    Electronic Resource
    Electronic Resource
    Springer
    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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  • 16
    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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  • 17
    Electronic Resource
    Electronic Resource
    Springer
    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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  • 18
    ISSN: 1432-0428
    Keywords: Insulin ; NSILA-S ; adipocytes ; hypophysectomized rats ; insulin-receptor ; NSILA-S-receptor ; glucose metabolism ; glucose transport
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Isolated fat cells from normal and hypophysectomized rats have been compared with respect to: 1) binding of insulin and NSILA-S, and 2) effects of these two hormones on glucose transport and metabolism. Although both insulin and NSILA levels were decreased in the serum of hypophysectomized rats, insulin binding was decreased to about 63% of normal, whereas NSILA-S binding remained unchanged. Basal lipogenesis was similar in adipocytes of normal and hypophysectomized rats, but was not stimulated by either insulin or NSILA-S. Similarly, neither of the two hormones stimulated the net gas exchange of “intact” fat pads from hypophysectomized rats. In striking contrast to these findings, 3-O-methylglucose transport in unstimulated fat cells of hypophysectomized rats proceeded at a maximal rate which was not further enhanced by insulin or NSILA-S. These results suggest that the lack of one or several hormones of the pituitary causes one or several enzyme deficiencies responsible for the limited rate of lipogenesis, which otherwiese would proceed at a very rapid rate because of unrestrained glucose transport.
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  • 19
    ISSN: 1432-0428
    Keywords: Insulin ; glucagon ; rat ; fetus ; neonate ; isolated islets ; glucose ; arginine ; leucine ; somatostatin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Islets were isolated by mild collagenase digestion and microdissection from rat fetuses 2 days before term and pups 1 or 2 days after birth and their insulin and glucagon secretion studied in vitro. Fetal B cells were stimulated by 16.7 mmol/l glucose, 20 mmol/l leucine or 20 mmol/l arginine. Fetal A cells were not affected by glucose or leucine, but were significantly stimulated by arginine. Somatostatin abolished the effect of arginine on both IRI and IRG output. Neonatal islets proportionally released more insulin and glucagon than their fetal counterparts, but reacted to the tested agents in a similar fashion. During the perinatal period, pancreatic insulin storage increased at a higher rate than that of glucagon. It is concluded that fetal B cells are equipped with sensors to a variety of agents and able to modulate their secretory rate according to the concentration of these agents. A cells are reactive to arginine 2 days before term but do not become glucose reactive until several days after birth.
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  • 20
    ISSN: 1432-0428
    Keywords: Insulin ; glucagon ; portal blood ; glucose ; arginine ; liver cirrhosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The portal vein was catheterized via the umbilical vein under local anaesthesia in 10 non-diabetic subjects about to undergo exploratory laparotomy and in 8 patients with liver cirrhosis. Immunoreactive insulin (IRI) and glucagon (IRG) were assayed in portal and peripheral blood before and during IV infusion of glucose (0.33 g/kg) or arginine (25 g). Basal peripheral plasma (IRI) levels were raised in cirrhotic patients (19±2 versus 10±1 μU/ml; P〈0.001). Basal portal insulin values, however, did not differ in the two groups. After glucose cirrhotic patients had higher peripheral insulin concentrations, compared to controls, significant at 45 and 60 minutes. In contrast portal insulin levels were higher in controls than in cirrhotics by 1 minute (403±43 versus 158±38 μU/ml; P〈0.001) and remained so for the 60 minutes of study. Similarly, after arginine cirrhotics had significantly higher peripheral insulin concentrations and lower portal concentrations than controls. Peak portal vein insulin levels were delayed in cirrhotics (168±16 μU/ml at 3 min) compared with controls (413±25 μU/ml at 1 min). In the basal state both portal and peripheral glucagon levels were higher in cirrhotics than control subjects. Unlike in controls, IV glucose did not suppress glucagon secretion in cirrhotic patients. Peripheral plasma glucagon concentrations after arginine were also consistently higher in cirrhotics than controls, but unlike insulin portal venous glucagon levels were also raised (1800±360 pg/ml, cirrhotics; 960±87 pg/ml, controls; P〈0.001; 1 min after arginine infusion). We conclude that insulin secretion is decreased in liver cirrhosis and that the peripheral hyperinsulinaemia observed reflects diminished hormone metabolism. The high plasma glucagon levels observed in cirrhotic patients are the result of pancreatic hypersecretion of glucagon.
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  • 21
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    Diabetologia 16 (1979), S. 201-206 
    ISSN: 1432-0428
    Keywords: Insulin ; glucose ; newborn ; early insulin response to feeding ; insulin in suckled infant ; newborn lambs ; newborn rabbits ; atropine and insulin secretion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Developmental changes in the plasma insulin response to milk ingestion have been determined in neonatal lambs fed by bottle and in naturally suckled infant rabbits. In lambs at 4 days of age and older plasma insulin increased within 5 min of suckling and declined again before increasing to a second peak 60 to 120 min after the feed. The early insulin peak was not associated with any change in plasma glucose and was absent in lambs at 1 day of age. When the early insulin peak was absent the increase in plasma glucose following the meal was greater. The early, apparently reflex, release of insulin also occurred in some ‘sham-fed’ lambs. Atropine administration before feeding abolished the early peak in insulin. A marked early peak of insulin release, not accompanied by any consistent change in plasma glucose, was also observed in naturally-suckled infant rabbits at 1, 5, 10 and 15 days after birth.
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  • 22
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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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  • 23
    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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  • 24
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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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  • 25
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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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  • 26
    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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  • 27
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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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  • 28
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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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  • 29
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    European journal of pediatrics 132 (1979), S. 189-195 
    ISSN: 1432-1076
    Keywords: First feed ; Newborn ; Insulin ; Glucagon ; C-peptide
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Blood glucose, insulin, C-peptide and glucagon were evaluated in 36 newborn term infants at birth, and before and 60 min after the first feed during the first day of life. Under basal conditions glycaemia diminished during the first day of life and glucagon increased, while insulin and C-peptide did not show any variation. The C-peptide: insulin molar ratio was higher in the newborn than in adults because of the longer half-life of C-peptide, probably due to reduced renal function in the neonatal period. The subjects were divided into two groups: 18 newborn infants were given a feed of commercially available milk powder reconstituted in water at 10% (5 ml/kg); the other 18 were given a feed of 5 ml/kg 10% glucose solution. In each group 6 were given the first feed after a fast of 6 h, 6 after a fast of 12 h, and 6 after a fast of 24 h from birth. After the first feed with milk, the average increase of glycaemia was 19.83 mg%, of insulin 6.06 μU/ml, and of C-peptide 1.88 ng/ml. After the first feed with glucose the average increase of glycaemia was 13.59 mg%, of insulin 2.46 μU/ml, and of C-peptide 0.59 ng/ml. Glucagon did not show significant changes after the first feed.
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  • 30
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    European journal of pediatrics 131 (1979), S. 185-198 
    ISSN: 1432-1076
    Keywords: Growth hormone ; Somatomedin ; Chronic renal failure ; Uraemic children ; Haemodialysis ; Insulin ; Arginine ; Carbohydrate intolerance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Plasma growth hormone (GH) concentrations after insulin and arginine stimulation were estimated in 11 dialyzed and 6 non-dialyzed children with chronic renal failure. Twenty healthy children served as controls. Plasma GH peak concentration and estimation of the total area under the plasma GH concentration-time curve by the trapezoidal rule were used to evaluate results. Elevated basal GH levels and an exaggerated response to the stimuli were seen in several of the patients. The causes of the abnormal GH secretion and the role of high GH levels in carbohydrate intolerance are discussed. No consistent pattern was seen in GH secretion during haemodialysis without glucose in the dialysate. In children undergoing haemodialysis with a fluid containing glucose, plasma GH fell considerably.
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  • 31
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    Diabetologia 16 (1979), S. 275-279 
    ISSN: 1432-0428
    Keywords: Insulin ; receptors ; mouse embryo retina ; Simian virus 40 ; established cell lines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The binding of125I-insulin to uncloned and cloned cultures of mouse retinal cells has been investigated. At 15° C, binding of the hormone reached a steady state by 60 min, while at 37° C equilibrium was reached earlier but at a lower level than at 15° C. Porcine insulin, porcine proinsulin and guinea pig insulin displaced labelled insulin in proportion to their known biological potency. A sharp pH dependence of the hormone binding was observed with an optimum at pH 7.8. The dissociation rate of the125I-insulin was increased in the presence of unlabelled hormone, suggesting the existence of negative cooperativity in the insulin-receptor interaction. The availability of established retinal cell lines with insulin receptors should facilitate the study of the insulin-retina interactions in a controlled in vitro system.
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  • 32
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    European journal of applied physiology 41 (1979), S. 51-59 
    ISSN: 1439-6327
    Keywords: Exercise ; Training ; Free fatty acids ; Triglycerides ; Insulin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Twenty healthy athletes performed a heavy physical exercise before and after a controlled training period of 3 months. As a result of physical training there was a reduction in lactate concentration during and after exercise. Plasma free fatty acids and triglyceride levels were lower at rest as well as during and after exercise. Insulin concentrations decreased during exercise before the training period whereas they remained constant afterwards. The composition of individual free fatty acids changed in the same way during exercise before and after training: fatty acids with shorter hydrocarbon chains increased, those with longer chains decreased. Comparing the pattern of individual free fatty acids before and after training a higher percentage of saturated and a lower percentage of mono-unsaturated fatty acids was observed. It is concluded that changes in the plasma free fatty acid profile during heavy exercise reflect a preferential uptake and oxidation of certain individual free fatty acids. The significance of training-induced changes in the plasma free fatty acid pattern is discussed.
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  • 33
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    European journal of applied physiology 41 (1979), S. 211-219 
    ISSN: 1439-6327
    Keywords: Adrenaline ; Noradrenaline ; Glucagon ; Insulin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of 9 weeks of training on responses of plasma hormones to swimming were studied in eight competitive swimmers who had not trained for several months. Two types of swimming tests were used: (1) 200 yd, a high intensity, exhausting type of exercise in which maximal effort was required both before and after training, and (2) 1000 yd, a pace type of exercise in which subjects swam as fast as possible prior to training and at the same rate after training. Plasma levels of glucagon increased and of insulin decreased during 1000 yd of swimming, but were not altered by 200 yd of swimming. No training effects were apparent in responses of plasma insulin and glucagon to these short-term, high intensity exercise tests. During the 1000 yd swim, plasma adrenaline was 0.8 ng/ml before vs. 0.1 ng/ml after training. Plasma noradrenaline response decreased from 3.4 to 1.2 ng/ml as a result of training. In the 200 yd swim, adrenaline, but not noradrenaline, was lower after training.
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  • 34
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    Medical & biological engineering & computing 17 (1979), S. 471-475 
    ISSN: 1741-0444
    Keywords: Bone ; Strain
    Source: Springer Online Journal Archives 1860-2000
    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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  • 35
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    Skeletal radiology 2 (1978), S. 239-242 
    ISSN: 1432-2161
    Keywords: Blastomycosis ; Bone ; Pulmonary ; Skin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract North American blastomycosis is a multisystem disease, primarily affecting the lungs and skin. The skeleton is affected in approximately 50% of cases. Bone symptoms as the primary clinical complaint are exceedingly rare. Two such cases are presented together with a brief discussion of this rare disease.
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  • 36
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    International orthopaedics 2 (1978), S. 171-175 
    ISSN: 1432-5195
    Keywords: Bone ; Allograft
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé Les auteurs ont étudié chez des rats consanguins la capacité des greffes osseuses fraîches ou conservées à provoquer des réponses immunes cellulaires. Cette réaction a été estimée grâce au test du rejet accéléré et au test de migration des leucocytes. Le premier, bien que relativement imprécis, a mis en évidence une sensibilisation chez la plupart des receveurs de ces greffes fraîches ou congelées. L'importance de cette sensibilisation est fonction des souches de rats utilisées. La plupart des receveurs n'ont pas été sensibilisés par l'os lyophilisé. Par contre, le test de nigration des leucocytes a nettement montre que des greffes d'os frais, spongieux ou cortical, ainsi que celles d'os congelé, sensibilisent les receveurs, L'os lyophilisé n'a sensibilisé que 30% des receveurs. La suppression des cellules de la moëlle de ces greffes n'empêche pas le déclenchement de l'immunité cellulaire. Les auteurs discutent la signification de ces constatations.
    Notes: Summary The ability of fresh and preserved bone grafts to evoke cell mediated immune responses has been studied in inbred rats. The second set skin graft assay and leucocyte migration (LM) test have been used for this purpose. The former test proved to be rather insensitive but indicated sensitisation in most recipients of fresh and frozen bone grafts. The degree of sensitisation was dependent upon the strain combination used. Freeze-dried bone did not sensitise the majority of recipients. The leucocyte migration assay showed clearly that grafts of fresh cancellous or cortical bone, or frozen bone do sensitise the host. Freeze-dried bone sensitised only 30% of recipients. It was also found that removal of bone marrow cells from the grafts did not impair immunogenicity with respect to cell mediated immunity. The implications of these findings are discussed.
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  • 37
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    International orthopaedics 2 (1978), S. 333-341 
    ISSN: 1432-5195
    Keywords: Bone ; Neoplasm ; Chondrosarcoma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé 163 cas de chondrosarcome repertoriés dans le Swedish Cancer Registry entre 1958 et 1968 ont été soumis à une analyse multifactorielle. 25, 38 et 35% étaient respectivement, fortement, modérément, et faiblement différenciés, et 2% étaient du type mésenchymateux. Les formes modérément et faiblement différenciées montraient habituellement une anaplasie généralisée, des noyaux multiples et souvent pâles, des nucléoles distincts, des images de mitoses et parfois des foyers de cellules fusiformes. Le degré de cellularité n'était pas en rapport avec la différenciation. Le pronostic dépend de la taille de la tumeur, de l'importance de sa vascularisation ainsi que de son stade histologique. Le siège de la tumeur est un élément primordial pour décider de l'importance de l'exérèse chirurgicale. La survie est liée à l'ablation primitive et radicale de la tumeur, par résection ou amputation. Indépendamment des particularités cliniques ou de celles de la tumeur, le meilleur traitement dans chaque cas consiste dans l'exérèse complète de la tumeur, en préservant la fonction dans la mesure du possible.
    Notes: Summary All cases of unequivocal chondrosarcoma recorded in the Swedish Cancer Registry for the years 1958 to 1968 were subjected to a multifactorial analysis. Of a total of 163 chondrosarcomas 25, 38 and 35% respectively were well, moderately and poorly differentiated, and 2% were of mesenchymal type. The moderately and poorly differentiated tumours characteristically exhibited general anaplasia, multiple often pale nuclei, distinct nucleoli, mitotic figures and occasionally spindle cell foci. The degree of cellularity was not of decisive value in differentiation. The prognosis was influenced by the extent and degree of vascularisation of the tumour and by the histopathological grading. The localisation of the tumour was of major importance in deciding the extent of operative treatment and prognosis. Primary radical removalen bloc by resection or ablative surgery was decisive for survival. Irrespective of the clinical and tumour variations, optimum treatment in individual cases involves complete removal of the tumour and, as far as possible, preservation of function.
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  • 38
    ISSN: 1432-1440
    Keywords: Bone ; Bone marrow ; Bone marrow biopsy ; Immunhistology ; Diabetes mellitus ; Diabetic microangiopathy ; Diabetic osteomyelopathy ; Knochen ; Knochenmark ; Myelotomie ; Immunhistologie ; Diabetes mellitus ; Diabetische Mikroangiopathie ; Diabetische Osteomyelopathie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Beckenkammbiopsien von 118 Patienten mit manifestem Diabetes mellitus wurden histologisch und histomorphometrisch ausgewertet und mit den klinischen Daten verglichen. Die histobioptischen Ergebnisse zeigen, daß sich die „diabetische Mikroangiopathie“ auch im Gefäßsystem des Knochenmarkes manifestiert. Mit Betonung im Bereich der Arteriolen und Kapillaren waren einerseits exsudativ-degenerative Wandveränderungen, andererseits entzündlich-fibrosierende perivaskuläre Reaktionen nachweisbar. Pathogenetisch sind diese Gefäßveränderungen bei Diabetes mellitus im Rahmen einer biochemisch veränderten Basalmembran mit erhöhter Permeabilität für Plasmaproteine zu erklären, die wiederum eine perivaskuläre Entzündungsreaktion auslösen. Neben der angiologischen Beurteilung des Diabetikers ermöglicht die Beckenkammbiopsie auch differenzierte und quantifizierbare Aussagen über hämatologische und osteologische Probleme im Rahmen des diabetischen Spätsyndroms. Bisher unbekannt war bei Diabetes mellitus die ausgeprägte Entzündungsreaktion des Knochenmarkstromas, die mit den serologischen Entzündungsparametern korreliert und sich klinisch häufig als sog. Infektanämie äußert. Eine Beteiligung der beschriebenen Myelitis an der Pathogenese des markatrophisch-osteoporotischen Bildes bei Diabetes mellitus kann angenommen werden. Knochenveränderungen bei Diabetes mellitus treten gegenüber einem altersentsprechenden Normalkollektiv signifikant häufiger auf und manifestieren sich als rarefizierende Osteopathie ohne wesentliche Umbausteigerung. Als Ursache kommen neben der dia betischen Mikroangiopathie mit begleitender Myelitis zahlreiche andere Faktoren, wie Störung der Kollagensynthese, des Kalziumstoffwechsels sowie Bewegungsmangel in Frage. Übereinstimmend mit den Ergebnissen anderer Autoren wiesen die Patienten mit Insulin-Therapie gegenüber oral eingestellten Diabetikern einen geringeren Osteoporosegrad auf. Unsere Ergebnisse erlauben die morphologische und klinische Definition einer diabetischen Osteomyelopathie mit eigenständiger Pathogenese. Sie ist charakterisiert durch 1. exsudativ-entzündliche Veränderungen der Knochenmarkgefäße, 2. plasmazelluläre Myelitis mit markatrophischer Komponente, 3. Osteoporose ohne nachweisbare Umbausteigerung.
    Notes: Summary Iliac crest biopsies from 118 patients with manifest diabetes were evaluated histologically and histomorphometrically and compared with the clinical data. The histobioptic results show that “diabetic microangiopathy” is also manifest in the vascular system of the bone marrow. Exudative degenerative changes in the vessel wall on the one hand, and inflammatory fibrosing perivascular reactions on the other were accentuated in the region of the arterioles and capillaries. These vascular changes in diabetes mellitus can be attributed to a biochemically altered basal membrane with increased permeability for plasma protein which, in turn, set up a perivascular inflammatory reaction. In addition to the angiological assessment of diabetics, iliac crest biopsy also permits differentiated and quantifiable statements on the haematological and osteological problems involved in the late diabetic syndrome. The marked inflammatory reaction of the bone marrow stroma was previously unknown in diabetes mellitus; it correlates with the serological inflammatory parameters and frequently becomes manifest as “anemia of chronic disorders”. It can be assumed that this reaction also takes part in the pathogenesis of the atrophy of the bone marrow and osteoporosis in diabetes mellitus. Bone changes in the form of atrophic osteopathy without essentially increased bone remodeling are to be found more frequently in diabetes mellitus than in a normal collective of similar age. In addition to diabetic microangiopathy with concomitant inflammation, numerous other causes such as disturbances of collagen synthesis, of calcium metabolism and lack of movement are to be considered. In accordance with other authors, the patients on insulin therapy showed a smaller degree of osteoporosis than orally adjusted diabetics. For these pathogenetic reasons, a specific diabetic osteomyelopathy can be established. It is characterised by: 1. exudative inflammatory changes of the bone marrow vessels, 2. plasmocytic marrow reactions and parenchymal reduction 3. osteoporosis without signs of increased remodeling of the bone.
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  • 39
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    Journal of molecular medicine 56 (1978), S. 755-759 
    ISSN: 1432-1440
    Keywords: Knochenhistologie urämischer Osteopathie ; Calciumstoffwechsel ; metabolische Knochenerkrankungen ; Mikromorphometrie ; Bone ; Metabolic Bone Disease ; Uremic Osteodystrophy ; Calcium Metabolism ; Malignant Tumors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary It is unknown whether histomorphometric parameters of bone surface remodelling change uniformly throughout the skeleton in metabolic bone disease. In patients without skeletal disease (n=8), in patients with chronic renal failure (n=13) and in patients with malignant tumors (n=11), post mortem bone samples were taken from the core of the 5th lumbar vertebra, from the iliac crest, from the femural head and from the interepicondylar portion of the distal femur. Histomorphometric analysis was carried out in undecalcified sections stained after Masson-Goldner. The dispersion of histomorphometric parameters between the different skeletal sites (cancellous bone) was evaluated by analysis of variance. There existed marked differences in the surface extension of the histomorphometric parameters which are related to bone remodelling, suggesting marked differences in the local remodelling rates (iliac crest 〉 lumbar vertebra 〉 femural head 〉 distal femur). In patients with bone disease all histomorphometric parameters changed uniformly throughout the skeleton with the exception of inactive osteoid. The study shows that in metabolic bone disease local factors do not interfere with remodelling in response to systemic factors. It also provides evidence that bone biopsy samples from iliac crest spongiosa reflect with reasonable accuracy the changes occurring elsewhere in the skeleton, although inactive osteoid may accumulate in the iliac crest out of proportion to its increase in low-turnover sites.
    Notes: Zusammenfassung Bei skelettgesunden Kontrollpersonen (n=8), bei Patienten mit chronischer Niereninsuffizienz (n=13) und bei Patienten mit malignen Tumoren (n=11) wurden post mortem Knochenbiopsie-Proben aus dem 5. Lendenwirbelkörper, aus dem Bekkenkamm, aus dem Femurkopf und aus dem interepikondylären Teil des distalen Femur entnommen. Unentkalkte, nach Masson-Goldner gefärbte Dünnschnitte wurden histomorphometrisch untersucht. Die Varianz einzelner histomorphometrischer Parameter zwischen den unterschiedlichen Skelettorten wurde durch Varianzanalyse überprüft. Die histomorphometrischen Parameter, welche in Beziehung zum inneren Knochenumbau stehen, waren in den einzelnen Skelettorten außerordentlich unterschiedlich. Die lokalen Umbauraten differieren daher wahrscheinlich stark (Beckenkamm 〉 Lendenwirbelkörper 〉 Femurkopf 〉 distaler Femur). Bei Patienten mit Knochenerkrankungen änderten sich alle histomorphometrischen Parameter gleichsinnig an allen untersuchten Skelettorten. Lediglich die Volumendichte und die Oberflächendichte inaktiven Osteoids zeigte in den einzelnen Skelettorten ein signifikant unterschiedliches Verhalten. Die Untersuchung belegt, daß bei systemischen Knochenerkrankungen lokale Faktoren nicht die Antwort des Skeletts auf systemische Stimuli beeinträchtigen. Die Messergebnisse belegen, daß Knochenbiopsie-Proben aus der Beckenkammspongiosa mit hinreichender Genauigkeit die Vorgänge widerspiegeln, die in anderen Skelettorten ablaufen. Lediglich für inaktives Osteoid konnte bei urämischen Patienten gezeigt werden, daß in der Beckenkammspongiosa eine — im Vergleich zu Skelettorten mit niedrigerer Umbaugeschwindigkeit — überproportioniert starke Akumulation stattfindet.
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  • 40
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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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  • 41
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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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  • 42
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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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  • 43
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    Calcified tissue international 26 (1978), S. 209-213 
    ISSN: 1432-0827
    Keywords: Mithramycin ; Bone ; β-Glucuronidase ; KT medium
    Source: Springer Online Journal Archives 1860-2000
    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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  • 44
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    Calcified tissue international 25 (1978), S. 249-254 
    ISSN: 1432-0827
    Keywords: Bone ; Oestrogens ; Oestrogen receptors ; Binding proteins
    Source: Springer Online Journal Archives 1860-2000
    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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  • 45
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    Calcified tissue international 25 (1978), S. 37-43 
    ISSN: 1432-0827
    Keywords: ESR ; Radiation free radicals ; CO3-Apatites ; Bone
    Source: Springer Online Journal Archives 1860-2000
    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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  • 46
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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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  • 47
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    Calcified tissue international 25 (1978), S. 227-232 
    ISSN: 1432-0827
    Keywords: Parathyroid hormone ; Bone ; Calcium ; Chick embryo ; Organ culture
    Source: Springer Online Journal Archives 1860-2000
    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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  • 48
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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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  • 49
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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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  • 50
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    Anatomy and embryology 153 (1978), S. 321-329 
    ISSN: 1432-0568
    Keywords: Bone ; Femur ; Density ; Hypergravity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Sixteen male Beagle dogs, 293 to 509 days old, were exposed almost continuously for 3 months to 2.0 G on a 7.9 m radius centrifuge. The dogs were maintained on the centrifuge by means of a specially designed, automated waste disposal and life support system. Bone density was measured by a 125I Profile Scanner in the anterior, medial, posterior and lateral cortex of the femoral mid-shaft. As compared to mean density in the femora of normal gravity controls, centrifuged dogs showed a 0.8% (P〈0.05) lower mean linear absorption in their femora. However, the regression of density on the square-root of cross-sectional area/π differs very significantly in the animals living at earth gravity and those living at hypergravity. Thin hypergravic bones are denser, thick hypergravic ones are less dense than the corresponding ones of normal gravity controls.
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  • 51
    ISSN: 1432-0428
    Keywords: Insulin ; pyruvate dehydrogenase ; enzyme interconversion ; heart muscle ; alloxan-diabetes ; heart perfusion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Evidence is presented for regulation by insulin of pyruvate dehydrogenase (PDH) interconversion in rat heart muscle in vivo and in vitro. In the alloxan diabetic rat the active (dephospho) enzyme amounted only to 12% of total PDH and was restored to 42% by insulin. Antilipolytic treatment of the diabetic animals was ineffective, indicating that the action of insulin was independent of a lowering of plasma non-esterified fatty acid concentration. On perfusion of isolated hearts from diabetic rats in the presence of glucose the proportion of pyruvate dehydrogenase in the active form remained low but was fully restored upon addition of insulin (2 mU/ml) to the medium. No effect of insulin was obtained in the absence of glucose. The correlation between the rate of pyruvate decarboxylation in the perfused heart and of pyruvate dehydrogenase activity, in vitro, suggests that in the diabetic heart the entry of pyruvate into the citric acid cycle is largely controlled by covalent modification of the pyruvate dehydrogenase complex rather than by feedback inhibition. The possible role of insulin therein is discussed.
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  • 52
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    Diabetologia 14 (1978), S. 59-64 
    ISSN: 1432-0428
    Keywords: Insulin ; anti-insulin serum ; glucagon ; glycogen ; glucose ; lactate ; free fatty acids ; fetus ; newborn ; neonatal hypoglycaemia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effect of the administration of anti-insulin serum to newborn rats, surgically delivered under ether anaesthesia at term, was examined with respect to liver glycogen concentration and plasma concentrations of glucose, lactate and free fatty acids. Newborn rats thus treated showed decreased liver glycogen concentrations and elevated plasma concentrations of glucose, lactate and free fatty acids compared to untreated control animals one hour later. These effects were dose-dependent with respect to the amount of anti-insulin serum administered. The simultaneous administration of glucagon with anti-insulin serum at birth was no more effective in mobilising glycogen stores than anti-insulin serum alone, although plasma glucose concentrations in these animals were higher and plasma lactate concentrations were lower. Either anti-insulin serum or glucagon abolished the postnatal hypoglycaemia observed in untreated neonatal rats. The rate of fall in plasma lactate concentrations after birth was stimulated in glucagon-treated rats but was retarded in rats treated with anti-insulin serum. Hormonal control over the initiation of glycogenolysis and gluconeogenesis in the newborn rat appears to be different, a fall in plasma insulin being the prime factor involved in triggering glycogen mobilization and a rise in plasma glucagon the prime event that initiates gluconeogenesis.
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  • 53
    ISSN: 1432-0428
    Keywords: Insulin ; pancreatic B cells ; serotonin ; fluorescence microscopy ; monoamine oxidase ; L-aromatic amino acid decarboxylase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The role of intracellular pancreatic B cell serotonin in the dynamics of insulin release was investigated in an in situ perfused rat pancreas preparation. Animals were pretreated with 5-hydroxytryptophan (5-HTP) to increase the intracellular levels of serotonin (5-HT) as shown by fluorescence histochemistry. Despite a clear induction of intracellular 5-HT fluorescence in pancreatic islets neither the pattern nor the total amount of insulin released were significantly modified after perfusion with either glucose or tolbutamide. However, the L-amino acid decarboxylase inhibitor, RO 4-4602, significantly decreased both phases of glucose-mediated insulin release in normal animals as well as in those receiving 5-HTP.
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  • 54
    ISSN: 1432-0827
    Keywords: Nerve growth factor ; Bone resorption ; Parathyroid hormone ; Insulin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The effects of 7S nerve growth factor (NGF) and its isolated α, β, and γ subunits on bone resorption were assessed in a tissue culture system in which the degree of resorption was determined by measuring the release of45Ca from prelabeled fetal rat radii and ulnae. It was found that 7S-NGF, through the activity of its γ, subunit, inhibits parathyroid hormone (PTH)-stimulated but not-unstimulated bone resorption. The following observations suggest that γ-NGF, a trypsin-like molecule, blocks PTH-induced bone resorption by enzymatic degradation of PTH: (a) γ-NGF does not inhibit bone resorption stimulated by the steroid, 1,25-dihydroxycholecalciferol; (b) trypsin is as effective as γ-NGF in inhibiting PTH-stimulated bone resorption; (c) the PTH-inhibitory action of both γ-NGF and trypsin are eliminated by inactivating these enzymes with diisopropyl fluorophosphate; and (d) addition of γ-NGF to the cultures 2 days after the inclusion of PTH does not result in inhibition of bone resorption. Similarly, when the subunit is added to the culture medium before the hormone, there is no inhibition of resorption. The latter observation suggests that the target of γ-NGF is the PTH molecule rather than its membrane receptors. Crystalline bovine insulin inhibits the γ-NGF suppression of PTH-induced bone resorption. This effect, however, is not mimicked by the addition of zinc, which is present in commerical insulin preparations, to the culture medium. Consequently, insulin must inhibit NGF by some mechanism other than the influence of zinc.
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  • 55
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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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  • 56
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    Calcified tissue international 26 (1978), S. 155-161 
    ISSN: 1432-0827
    Keywords: Plasma protein ; Glycoprotein ; Bone ; Glucosamine
    Source: Springer Online Journal Archives 1860-2000
    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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  • 57
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    European journal of pediatrics 128 (1978), S. 187-195 
    ISSN: 1432-1076
    Keywords: Insulin ; Glucagon ; Glucose ; Free fatty acids ; Newborn infant ; Cord blood ; Arterio-venous difference
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Bei Geburt ist der Blutzucker bei der Mutter am höchsten, niedriger in der Nabelvene und am tiefsten in der Nabelarterie. Diese Unterschiede sind statistisch signifikant. Auch die Konzentration der freien Fettsäuren (FFS) weist ein Konzentrationsgefälle von der Mutter über die Nabelvene zur Nabelarterie auf. Diese Resultate unterstützen die Annahme, daß Glucose und FFS von der Mutter via Placenta auf den Fötus übergehen. Im mütterlichen Blut ist die Insulinkonzentration höher als im Nabelschnurblut. Es ist kein eindeutiger Unterschied zwischen Nabelvene und-arterie vorhanden. Nur im mütterlichen Blut ist eine signifikante Korrelation zwischen Glucose und Insulin nachweisbar. Hinsichtlich der Glucagonkonzentration bestehen nur geringe Unterschiede zwischen dem mütterlichen Blut und der Nabelarterie. Sie ist aber in der Nabelvene signifikant höher als bei der Mutter. Das Verhalten von Insulin und Glucagon ist vereinbar mit der Annahme, daß diese Hormone die Placenta nicht in wesentlichem Ausmaß passieren und im Fötus gebildet werden. In den ersten Stunden nach der Geburt sinkt die Glucose, die FFS steigen an, Insulin sinkt ab, und es erfolgt ein wesentlicher Anstieg von Glucagon.
    Notes: Abstract At birth there is a statistically significant correlation between the maternal blood sugar and the umbilical venous and arterial blood glucose. The glucose concentration in the mother is higher than in the umbilical vein, and in the latter higher than in the umbilical artery. The free fatty acids also show a falling gradient from the mother to the umbilical vein and artery. This supports the assumption that glucose and FFA pass the placenta from the mother to the foetus. Insulin concentration is significantly higher in the mother than in the cord blood. There is however no difference between umbilical venous and arterial plasma insulin. A statistically significant correlation between glucose and insulin is only demonstrable in the maternal blood. Glucagon levels are about the same in maternal and umbilical arterial blood, but are significantly higher in umbilical venous blood. These results are consistent with the supposition that insulin and glucagon do not cross the placenta to a significant extent and can be synthesised by the foetus. In the first few hours after birth, a fall of glucose and a rise in FFA occur at the same time. Insulin tends to be lower than at birth and glucagon rises.
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    Pflügers Archiv 373 (1978), S. 237-242 
    ISSN: 1432-2013
    Keywords: Pancreatic islets ; K+ ; Rb+ ; Glucose ; Insulin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effect of glucose upon the handling of K+ by islets of Langerhans removed from normal rats was investigated by measuring both the net uptake of86Rb+ and its efflux from prelabelled islets. The inflow of K+ into islet cells is mediated, in part at least, by an ouabain-sensitive pump. Glucose fails to affect the inflow rate of K+, but it apparently decreases the permeability of islet cells plasma membrane to effluent K+. The glucose-induced change in permeability is a rapid and rapidly reversible phenomenon. Under steady-state conditions, it leads to an increase in the islet cells K+ pool and a decrease of its fractional turnover rate.
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  • 59
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    Pflügers Archiv 375 (1978), S. 197-206 
    ISSN: 1432-2013
    Keywords: Pancreatic islets ; Na+−K+ ; Ouabain ; Veratridine ; Glucose ; Insulin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effect of glucose upon the handling of22Na+ by pancreatic islets was investigated. Using a triple-isotope technique, the apparent concentration of Na+ in islet cells was estimated at 50–75 mM. The pattern of22Na+ efflux from perifused islets indicates that this intracellular Na+ load is compartmentalized among a small, possibly organelle-bound pool characterized by a low fractional turnover rate (5%/min) and a large, presumably cystosolic pool displaying a much higher fractional turnover rate (20–34%/min). Glucose provokes a rapid, pronounced and sustained increase in the fractional outflow rate of Na+ across the plasma membrane and, under steady-state conditions, moderately reduces the concentration of Na+ inside the islet cells. The glucose-induced increase in Na+ outflow rate, which is also observed in response to glyceraldehyde and does not require the presence of extracellular Ca2+, might be mediated, in part at least, by an ouabain-resistant ionophoretic system. The experimental data suggest that glucose also increases the inward transport of Na+ in islet cells by a veratridine-sensitive channel.
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  • 60
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    Bulletin of experimental biology and medicine 86 (1978), S. 1621-1624 
    ISSN: 1573-8221
    Keywords: Insulin ; prednisolone ; glucose reabsorption ; tubular secretion ; excretion of sodium by the kidney
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract In experiments on dogs a single injection of insulin in a dose of 1 unit/kg body weight caused an increase in the maximal reabsorption of glucose and secretion of diodone and reduced the excretion of sodium without any change in glomerular filtration. These effects depend on the direct action of insulin, for when it was injected directly into one of the renal arteries its action was manifested only in the kidney on the side of infusion. Prednisolone had no significant effect on glucose and diodone transport when given as a single injection (3–4 mg/kg) or over a period of 10 days (1.5–2 mg/kg daily).
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  • 61
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    European journal of applied physiology 38 (1978), S. 301-305 
    ISSN: 1439-6327
    Keywords: 10,000 m run ; Glucose ; Insulin ; Lipids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Thirteen conditioned athletes were studied before and 5 min after running 10,000 m. This distance was run in an average of 41±4 min. All runners lost weight and accompanying this weight loss was an increase in the serum osmolality in the six runners in which it was measured. There was a significant increase in serum glucose (96±11 mg-% before run; 170±48 mg-% after run) and this increase was inversely correlated with running time. There was also a small, but significant, increase in serum insulin (15±2 ΜU/ml before run; 19±4 ΜU/ml after run). There was no consistent effect of running 10,000 m on serum cholesterol and triglyceride levels and on plasma lipoprotein electrophoresis patterns.
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  • 62
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    European journal of applied physiology 39 (1978), S. 53-61 
    ISSN: 1439-6327
    Keywords: Exercise ; Insulin ; Glucagon ; Lipolysis ; Glucose ingestion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of glucose ingestion on the changes in blood glucose, FFA, insulin and glucagon levels induced by a prolonged exercise at about 50% of maximal oxygen uptake were investigated. Healthy volunteers were submitted to the following procedures: 1. a control test at rest consisting of the ingestion of 100 g glucose, 2. an exercise test without, or 3. with ingestion of 100 g of glucose. Exercise without glucose induced a progressive decrease in blood glucose and plasma insulin; plasma glucagon rose significantly from the 60th min onward (+45 pg/ml), the maximal increase being recorded during the 4th h of exercise (+135 pg/ml); plasma FFA rose significantly from the 60th min onward and reached their maximal values during the 4th h of exercise (2177±144 ΜEq/l, m±SE). Exercise with glucose ingestion blunted almost completely the normal insulin response to glucose. Under these conditions, exercise did not increase plasma glucagon before the 210th min; similarly, the exercise-induced increase in plasma FFA was markedly delayed and reduced by about 60%. It is suggested that glucose availability reduces exercise-induced glucagon secretion and, possibly consequently, FFA mobilization.
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  • 63
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    Cell & tissue research 194 (1978), S. 387-398 
    ISSN: 1432-0878
    Keywords: Isolated pancreatic islets ; Temperature ; Exocytosis ; Insulin ; Calcium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Exposure of isolated pancreatic islets (mouse or rat) to low temperature (2° C) evoked a threefold increase in insulin release irrespective of the glucose concentration in the incubation medium. Cold-induced release was transient and rewarming to 37° C restored the sensitivity of B-cells to glucose stimulation. In islets cooled to 2° C, exocytotic profiles could easily be detected both by thin-section and freeze-fracture electron microscopy. As revealed by the freeze-fracture technique, the number of exocytotic profiles per membrane area was increased three-to fourfold as compared to islet cells incubated at 20° C. This was paralleled by intracellular fusion of secretory vesicles. Cold-induced insulin release was not affected by theophylline, cytochalasin B, omission of extracellular Ca++ or D600. Replacement of extracellular Na+ with choline or sucrose suppressed the increase in insulin release and in frequency of exocytotic profiles recorded after exposure to 2° C. It is suggested that a redistribution of Ca++ from intracellular stores, possibly mediated by an increase in intracellular Na+, triggers exocytosis of insulin granules upon exposure to cold.
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  • 64
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    Cell & tissue research 187 (1978), S. 535-550 
    ISSN: 1432-0878
    Keywords: Insulin ; Electron microscopy (serial sections) ; Optical diffraction ; Crystalline beta granules (rhombohedra, dodecahedra, dipyramids, prisms)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of crystalline beta granules of the islets of Langerhans in the alligator has been investigated. From optical diffraction analysis and serial sectioning, the existence of four distinct types of crystalline inclusions was established in ultrathin sections. The first type is the most frequent and is interpreted as a rhombohedroni with a base, the ortho-hexagonal unit-cell edges being a=18.9 nm, c=23.0 nm. The second type of crystal (not observed in serial sections) is found compatible with a rhomb-dodecahedron which indexes on a cubic cell with a=9.6 nm. The third type of crystal was assigned to dipyramids. Dipyramids are extremely rare, and only two diffraction patterns were obtained; their crystal system could not be determined. Prisms, which are second in abundance, represent the fourth type of crystal. Spacings as well as the symmetry differ from those of the above three crystal types and indicate a tetragonal cell with a=4.2 nm, c=14.2 nm. The data for the prismatic crystals are strikingly similar to those of proinsulin and may represent the first case of agreement between crystals (i) formed in vitro and studied by X-ray diffraction and (ii) those investigated in situ by electron microscopy.
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  • 65
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    International orthopaedics 1 (1977), S. 5-8 
    ISSN: 1432-5195
    Keywords: Bone ; Transplantation ; Antigens
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé Les réactions immunologiques, cellulaires et humorales, ont été étudiées sur des rats consanguins, chez lesquels ont été transplantés, tant de l'os que du tissu cortical, compte non tenu des principales barrières d'histocompatibilité. Les résultats obtenus après culture lymphocytaire et étude de la cytotoxicité sérologique font penser que les antigènes de transplantation se situent à la surface des cellules osseuses.
    Notes: Summary Cellular and humoral immune responses were studied in inbred rats grafted with complete bone and marrow-free cortical bones transplanted across major histocompatibility barriers. Mixed lymphocyte cultures and serum cytotoxicity results suggest that transplantation antigens are present on bone cells surfaces.
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  • 66
    ISSN: 1432-2013
    Keywords: Insulin ; Epinephrine ; Norepinephrine ; Glycogen ; Gluconeogenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The significance of glucagon for post-exercise glucose homeostasis has been studied in rats fasted overnight. Immediately after exhaustive swimming either rabbit-antiglucagon serum or normal rabbit serum was injected by cardiac puncture. Cardiac blood and samples of liver and muscle tissue were collected before exercise and repeatedly during a 120 min recovery period after exercise. During the post-exercise period plasma glucagon concentrations decreased but remained above pre-exercise values in rats treated with normal serum, while rats treated with antiglucagon serum had excess antibody in plasma throughout. Nevertheless, all other parameters measured showed similar changes in the two groups. Thus after exercise the grossly diminished hepatic glycogen concentrations remained constant, while the decreased blood glucose concentrations were partially restored. Simultaneously concentrations in blood and serum of the main gluconeogenic substrates, lactate, pyruvate, alanine and glycerol declined markedly. During the post-exercise period NEFA concentrations in serum and plasma insulin concentrations remained increased and decreased, respectively, while plasma catecholamines did not differ from basal values. Muscle glycogen concentrations decreased slightly. These findings suggest that in the recovery period after exhaustive exercise the increased glucagon concentrations in plasma do not influence gluconeogenesis.
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  • 67
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    Pflügers Archiv 369 (1977), S. 61-64 
    ISSN: 1432-2013
    Keywords: Development ; Monosaccharide transport ; Insulin ; Muscle ; Lamb
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Uptake of the nonmetabolizable model sugar 3-0-methylglucose (3-MG) into skeletal muscle (musculi cricothyreoidei) of the lamb decreases with advancing age. Forestomach development does not affect 3-MG uptake. The stimulating effect of insulin upon 3-MG uptake also declines with age. Forestomach development does not influence this insulin effect.
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  • 68
    ISSN: 1432-2013
    Keywords: Bone ; OTC induced fluorescence and autofluorescence ; Intensity and spectrofluorometry ; Age and sex relationship
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Simple and rapid methods for the determination and detection of autofluorescence and oxytetracycline (OTC) induced fluorescence in powdered and intact bone (without previous chemical extraction of the antibiotic) were used to estimate age and sex related differences in the rat femur. The autofluorescence always had collagen characteristics; it increased with age and was not sex dependent. The intensity of OTC induced fluorescence decreased with age, being higher in males than in females. In the oldest animals, however a slight increase in the fluorescence intensity was observed, and sex differences disappeared. The spectrofluorometric measurements of intact femora indicate a higher OTC retention on the bone surface of young animals and adult males but not in adult females. The results indicate that the determination of OTC retention in the bone using our quantitative fluorometric method and the detection of OTC deposition at bone surface using a spectrofluorometric technique can be a sensitive and inexpensive tool for experimental studies of bone changes in physiological and pathological conditions.
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  • 69
    ISSN: 1432-2307
    Keywords: Insulin ; Antibody ; Glomerulus ; Mesangium ; Quantitative morphology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Thirty rabbits were immunized with MC insulin and high-molecular impurities of commercial insulin preparations (a+b component) over 30, 60 and 90 days. The serum insulin antibody titer was determined in animals as the insulin binding capacity. Further, a quantitative morphological analysis of the various types of glomerular cells and of the mesangium was performed on the glomeruli as a blind study. Significant mesangial cell proliferation and an increase in mesangial matrix were found on treatment with the a+b component whereas the animals treated with MC insulin exhibited only a transient and slight mesangial activation after 30 days. There was a positive correlation between the magnitude of the insulin binding capacity and the mesangial activation. Hence, the glomerular changes which are observed after treatment with insulin which is not highly purified must be attributed to the high molecular weight contaminants. Heterologous pure insulin must be regarded as having virtually no immunological effect.
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  • 70
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    Calcified tissue international 22 (1977), S. 27-33 
    ISSN: 1432-0827
    Keywords: Protein ; Bone ; Blood plasma ; Dentine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract The spectrum of plasma proteins present in human cortical bone and permanent dentine has been determined. One plasma glycoprotein, theαHS-glycoprotein, was found to be present at a high concentration in both bone and dentine and was shown to be concentrated in the mineralized tissues with respect to the other plasma proteins by factors of between 30 and 100. In this respect theαHS-glycoprotein is analogous to the G2B-glycoprotein and α-glycoprotein of bovine and rabbit b one, respectively. The binding ofαHS-glycoprotein and albumin to calcium phosphates generated within serum samples has been studied at different serum: precipitate ratios. In each case all theαHS-glycoprotein was removed from the samples and theαHS-glycoprotein was concentrated with respect to albumin by factors ranging from 370 at the highest serum: precipitate ratio to 25 at the lowest ratio. The plasmaαHS-glycoprotein concentrations of patients with Paget's disease of bone were shown to be substantially lower than the normal range, with significant negative correlation between theαHS-glycoprotein concentration and the plasma alkaline phosphatase activity.
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  • 71
    ISSN: 1432-0827
    Keywords: Bone ; Calcium ; Strontium ; Apposition ; Tracer analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract 1. Evidence has accumulated that the rate of acceretion (A) of calcium to bone is the sum of two fluxes; apposition involving the laying down of new bone and augmentation which is the result of slow exchange of non-surface bone calcium with plasma calcium pools as the result of solid state diffusion. 2. A method has been devised for separating A into its two components. It requires the use of45Ca or, for clinical studies,85Sr as a calcium tracer. Studies which are initiated with a combined accretion rate-calcium balance study, are concluded with an estimate of the exponent of the power function which has been found to describe the whole body retention of tracer from the second month onward. 3. The impulse response function of the skeleton for the tracer is then calculated, making the assumption that in any uniform volume of bone, osteoclastic resorption is a first order process. Making in addition certain simplifying assumptions, which are shown to have a modest influence on the final results, a mean rate of bone resorption can be calculated using a development of the well known Stewart-Hamilton formula. The apposition rate is calculated as the sum of the resorption rate and the calcium balance. Augmentation and diminution, defined as equal and opposite exchange processes, are given by the difference between A and the apposition rate. 4. The results of our first thirteen studies in normal subjects and patients with metabolic bone disease are presented, together with analyses of some data from the literature. It is concluded that the development of an atraumatic method for measuring rates of bone formation and resorption in the whole body would be an important advance in the study of metabolic bone disease, and this work is presented so that critical comparisons may be initiated between this tracer method and independent histological methods for measuring these parameters.
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  • 72
    ISSN: 1432-0827
    Keywords: Bone ; Diphosphonates ; Bone resorption ; Bone formation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Male rats weighing 100 g were assigned to groups and injected daily for 10 days with vehicle (control), 0.4, 2.0, 4.0, 10.0, or 20.0 mg/kg/day of ethane-1-hydroxy-1,1-diphosphonate (EHDP) or dichloromethylene diphosphonate (Cl2MDP). The proximal tibial metaphysis and epiphysis were assayed for changes in percentage of hard tissue and bone formation parameters. From the data, information about hard tissue resorption was deduced. All doses of Cl2MDP and doses of 2.0 mg EHDP/kg/day and greater caused significant increases in percentage of hard tissues with Cl2MDP being more effective than similar doses of EHDP in decreasing bone resorption. Osteoclast population parameters were increased with all doses of both Cl2MDP and EHDP with Cl2MDP having a greater effect than similar doses of EHDP. Decreases in the proliferation of the osteoprogenitor pool parallel the decreases in osteoblasts and bone formation parameters. These decreases in osteoprogenitor pool proliferation do not account for the increases with diphosphonates in osteoclast population parameters.
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  • 73
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    Calcified tissue international 24 (1977), S. 65-72 
    ISSN: 1432-0827
    Keywords: Bone ; Strength ; Tension ; Microstructure ; Osteon
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Standardized human and beef femoral compact bone specimens were tested in tensile impact and the dynamic mechanical properties were determined. The microstructure of 45 beef and 47 human bone specimens were examined histologically to determine if there is a structural basis to account for strength differences in the bone samples. Strong negative correlations were obtained between the maximum stress and the percentage area of secondary osteons in each specimen. For human bone samples, the energy absorption capacity and the modulus of elasticity were also found to have strong negative correlations with the percentage area of secondary osteons present in each specimen. Linear regression equations were obtained describing the impact strength properties in terms of the percentage areas of secondary osteons and cavities in the samples. Fracture surfaces of the tested bone specimens were examined in a scanning electron microscope. Most surfaces exhibited a fairly rough texture indicating a quasi-cleavage type of failure. Fractographic analysis of bone fracture surface was helpful in understanding the micromechanics of bone fracture.
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  • 74
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    Calcified tissue international 23 (1977), S. 215-223 
    ISSN: 1432-0827
    Keywords: Amorphous mineral ; Bone ; Electron microscopy ; Ultracryotomy ; Ultramicro-incineration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The fine structure of the extracellular phase of avian medullary bone and embryonic chick femur was examined in thin sections prepared by ultracryotomy and ultramicroincineration. Since contact with solutions was completely avoided, little or no loss or dislocation of mineral constituents could occur. Amorphous bone mineral (ABM) was present in two forms: as 15–30 nm spheres and as a structure-free haze. Removal of all organic material by low temperature ashing left the ABM intact. Crystals were usually associated with the ABM. In newly ossifying regions clusters or nodules of randomly oriented crystals and ABM appeared to coalesce when they reached approximately 1 μm in diameter. In highly calcified regions crystals appeared to be oriented along collagen fibers. ABM did not appear to be associated with collagen. Unmineralized collagen was visible in osteoid after staining with dry OsO4 vapor and it appeared to be diverted around nodules. Structures which resembled matrix vesicles were present. Selected area electron diffraction patterns indicated the presence of hydroxyapatite.
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  • 75
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    Calcified tissue international 22 (1977), S. 183-189 
    ISSN: 1432-0827
    Keywords: Calcium ; Strontium ; Bone ; Mathematical modelling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract 1. A method has been devised for comparing the impulse response functions of the skeleton for two or more boneseeking tracers, and for estimating the contribution made by measurement errors to the differences between any pair of impulse response functions. 2. Comparisons were made between the calculated impulse response functions for47Ca and85Sr obtained in simultaneous double tracer studies in sixteen subjects. Collectively the differences between the47Ca and85Sr functions could be accounted for entirely by measurement errors. 3. Because the calculation of an impulse response function requires fewera priori assumptions than other forms of mathematical analysis, and automatically corrects for differences induced by recycling of tracer and non-identical rates of excretory plasma clearance of tracer, it is concluded that differences shown in previous in vivo studies between the fluxes of*Ca and*Sr into bone can be fully accounted for by undetermined oversimplifications in the various mathematical models used to analyse the results of those studies.85Sr is therefore an adequate tracer for bone calcium in most in vivo studies.
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  • 76
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    Calcified tissue international 22 (1977), S. 219-226 
    ISSN: 1432-0827
    Keywords: Hydroxyapatite ; Bone ; X-ray Diffraction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract Evidence relating to the existence of crystalline bone mineral in vivo is considered, and bone apatite crystal structure investigated using an x-ray powder diffraction technique. Specimens of femoral compacta excised post-mortem from male and female subjects ranging from 3 1/2 years to 87 years of age have been studied. Values of the ratio c/a of bone apatite crystal cell axes for females are significantly higher (p〈0.05) than for males. Moreover, significant change of c/a with age is observed for males (p=0.0005) but not for females (p=0.30). Differences in c/a are interpreted as indicating substitution of constituent ions in the bone apatite crystals.
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  • 77
    ISSN: 1432-0827
    Keywords: Diphosphonate ; Bone ; Osteoclasts ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract Male rats weighing 100 g were injected with vehicle (control group), 0.4 or 4.0 mg/kg/day of ethane-1-hydroxy-1,1-diphosphonate (EHDP). Beginning after 6 days of EHDP treatment all rats received six subcutaneous injections of3H-thymidine at 8 h intervals. The multiple labeling index of autoradiographically defined labeled cells was determined for the osteoprogenitor cells of the primary spongiosa of the proximal tibial metaphysis. The osteoclasts in the proximal tibial metaphysis were assayed for population parameters and incorporation of labeled nuclei at sequential intervals after the administration of3H-thymidine. After 6 days of EHDP pre-treatment the multiple labeling index of the osteoprogenitor cells was reduced with 4.0 mg/kg/day dose of EHDP. At the beginning of the experimental kinetic sampling period, after the 6 days of EHDP pre-treatment, EHDP treatment resulted in significant increases in the numbers of osteoclasts, nuclei per osteoclast profile, and total osteoclast nuclei. During the sampling period, the 4.0 mg/kg/day dose of EHDP caused further increases in the number of total osteoclasts. EHDP treatment caused a marked increase in the rate of incorporation and accumulation of3H-thymidine-labeled nuclei in osteoclasts. Thus, EHDP causes an accelerated rate of osteoclast production from precursor cells in spite of its ability to slow bone resorption. Although the origin of osteoclast nuclei is not clear, the kinetic data from this study suggests that osteoclast nuclei are not arising from osteoprogenitor cells or osteocytes in the EHDP-treated animals.
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  • 78
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    Calcified tissue international 22 (1977), S. 303-313 
    ISSN: 1432-0827
    Keywords: Osteoclasts ; Sedimentation ; Isolation ; Cells ; Bone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract A method is presented for separating osteoclasts from the heterogeneous population of bone and marrow cells. Cell suspensions were prepared from femora of young rabbits by mechanical dispersion. The starting cell suspension typically contained only 1.0%±0.5 osteoclasts. Following an initial 45 min of unit gravity sedimentation in a lucite chamber osteoclasts were primarily distributed in fractions 2–5. A second 45-min sedimentation of these pooled fractions yielded cell suspensions containing greater than 30% osteoclasts (as much as a 50-fold increase over starting percentages). Linear scan analysis, however, revealed that osteoclasts accounted for 73.14%±0.58 of the cell colume. Subsequent in vitro experiments demonstrated linear incorporation of3H-leucine into TCA precipitable protein for cells comprising the osteoclast fraction. Concomitant radiautographs revealed radioactive label in isolated osteoclasts.
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  • 79
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    Calcified tissue international 22 (1977), S. 275-284 
    ISSN: 1432-0827
    Keywords: Bone ; Calcium ; Collagen ; Dentine ; Phosphoprotein
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract Calcium-binding and biochemical studies have been applied to characterize the state of the carboxylate and protein-bound phosphate groups in the EDTA-demineralized matrices of rat bone and dentine. The organic phosphate and carboxylate content of demineralized bone is virtually identical to that of purified steer skin collagen whereas demineralized dentine has a significantly higher phosphate and carboxylate content, presumably due to the presence of an acidic non-collagenous phosphoprotein. Two classes of calcium-binding sites can be detected in demineralized bone, demineralized dentine, and purified, reconstituted collagen. The number of strong calcium-binding sites correlates with the number of protein-bound phosphate groups. Depending on the preparative procedure, seven to nine such sites (per collagen molecule) are present in dentine, and one to two in the purified reconstituted collagen and in bone. The binding constant for the dentinal sites (1.1×104 M−1), however, is 20 times greater than that for bone or reconstituted collagen fibrils from skin. We tentatively conclude that the strong calcium-binding site in bone and reconstituted collagen is of the form protein-PO 4 − Ca++ whereas in dentine it is of the form the weak binding sites in bone and dentine are of the form protein-COO-Ca++; and that approximately 160 of the 217 carboxylate groups of the collagen molecules of dentine or bone are present as electrostatic linkages of the form protein-COO−+H3N-protein.
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  • 80
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    Calcified tissue international 22 (1977), S. 315-327 
    ISSN: 1432-0827
    Keywords: Bone ; Bioelectricity ; Strain ; Locomotion ; Osteoporosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract Using wet dead specimens it was possible to show that the size and form of strain-related electrical potentials on the surface of sheep radii were related both to the amount of strain, and the strain rate, over the range of these recorded during locomotion. Using the same electrode and amplifier system in vivo changes in surface strain and surface charge were recorded from the radius of three sheep during locomotion. During slow locomotion electrical changes were negligible. At medium speed they were most variable, and profoundly influenced by small alterations in the timing and pattern of strain change. When locomotion was fast the electrical waveform reflected fairly faithfully the changes in strain on the bone surface.
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  • 81
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    Calcified tissue international 22 (1977), S. 329-331 
    ISSN: 1432-0827
    Keywords: Bone ; Fracture ; Mineral
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract The bone mineral content was measured by gamma absorptiometry in patients who had sustained fractures of the upper limb. Measurements were taken on the shafts of the forearm and in the trabecular bone immediately proximal to the wrist. Fractures of the surgical neck of the humerus and fractures of the shaft of the humerus did not significantly influence the bone mineral content of the ipsilateral forearm. Fracture of the radius and the ulna, however, caused a 15% loss of the bone mineral content in the trabecular bone proximal to the wrist, whereas the mineral content on the shafts of the fractured forearms increased or decreased depending on the fracture site. The findings suggest that measurements of bone mineral content of the forearm are not necessarily invalidated if there has been a fracture of the same limb. Only if the forearm itself is fractured should measurements on this site be avoided.
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  • 82
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    Calcified tissue international 23 (1977), S. 113-114 
    ISSN: 1432-0827
    Keywords: Bone ; Absorption Spectra ; Collagen ; Hydroxyapatite
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Absorption spectra of human bone and its two major constituents (collagen and apatite) were obtained in the wavelength region extending from 2000 to 12,000 Å. In the last two cases a, minimum transmission (maximum absorption) was uniformly observed in the ultraviolet region. The two samples after exposure to ultraviolet radiations show a shift in the peak positions. Absorption peaks in the total bone spectra are not reproducible in its two constituents. After exposure to UV radiations the position of maximum absorption is displaced. A possible interpretation of the observed results is presented.
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  • 83
    ISSN: 1432-0827
    Keywords: Parathyroidectomy ; Diphosphonates ; Bone ; Collagen ; Hydroxyproline
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Disodium ethane-1-hydroxy-1,1-diphosphonate (EHDP) may impair mineralization and reduce turnover of bone. However, its administration has been shown to lead to an accumulation of osteoid in both man and the rat. Using rats, the effects of surgical parathyroidectomy and administration of EHDP (30 mg EHDP/kg body weight by subcutaneous injection daily for 5 days) upon bone composition, uptake of3H-proline into hydroxyproline in bone and the subsequent urinary excretion of labelled and unlabelled hydroxyproline have been compared. Both parathyroidectomized (PTX) rats and EHDP-treated animals accumulated more hydroxyproline in bone and excreted less total urinary hydroxyproline than sham-PTX control animals, the changes induced by EHDP being of greater magnitude than those induced by surgical parathyroidectomy. Skeletal buildup of hydroxyproline was associated with decreased catabolism of mature collagen rather than enhanced synthesis of hydroxyproline in bone. EHDP administration, although decreasing urinary excretion of newly synthesised hydroxyproline, did not alter the skeletal synthesis of hydroxyproline as measured by uptake of3H-proline. In all parameters measured, responses to EHDP were similar in PTX and sham-PTX rats. It is concluded that depression of parathyroid hormone mediated bone turnover may have contributed to, but did not fully account for, the lowering of bone turnover and changes in bone composition induced by EHDP in sham-PTX rats in the present experiment.
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  • 84
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    Calcified tissue international 23 (1977), S. 161-170 
    ISSN: 1432-0827
    Keywords: Bone ; Growth ; Rat ; Remodeling ; Tetracyclines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Cortical bone remodeling along the femur diaphysis was determined in normal female rats (Sprague-Dawley) with the tetracycline technique. Three segments on the cortical bone circumference (the anterolateral, the medial, and the posterior) were found to be most suitable for the study of the remodeling process. Oxytetracycline was administered at age 60 and 75 days, and groups of animals were killed at age 75, 85, 95, and 105 days. The accumulated endosteal growth during age 60 to 75 days in the anterolateral segment was found to increase uniformly in the distal direction along the femur diaphysis. A method is described where this accumulated endosteal growth is used. This method eliminates the use of calipers to determine the section level and makes it possible to study comparable sections even after varying periods of time. The proximal part of the diaphysis showed periosteal apposition in all three segments. The periosteal apposition turned into resorption in the distal part of the diaphysis in the anterolateral and medial segments, whereas the periosteal appsition increased in the posterior segment. The endosteal growth increased in the distal direction in the anterolateral and medial segments. Irregular OTC bands made measurements of endosteal remodeling in the posterior segment impossible. The cortical width decreased in the distal direction along the femoral shaft. Comparison between the different age groups is described and also the relation between the accumulated endosteal growth and the diameter of the medullary cavity.
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  • 85
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    Calcified tissue international 23 (1977), S. 1-5 
    ISSN: 1432-0827
    Keywords: Water ; Bone ; Homeostasis ; Structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary A short review is given of the water in bone. Various analyses of bone water content are discussed, and its possible location is considered in relation to the behaviour of water in isolated components of bone. Some of the difficulties encountered in examining such microscopic phenomena as water structure in a heterogeneous system such as bone are also discussed.
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  • 86
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    Calcified tissue international 24 (1977), S. 41-46 
    ISSN: 1432-0827
    Keywords: Lead salt ; Bone ; Mobilization ; Hypercalcemia ; Hyperphosphatemia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The present study is an investigation of the mechanism of hypercalcemia and hyperphosphatemia induced by the intravenous injection of lead acetate (Pb-Ac). A total of 118 male rats were injected with 30 mg/kg of Pb-Ac, or with 16.5 mg/kg of sodium acetate as the control. The levels of serum calcium, phosphorus and lead were then determined at various time periods after the injections. Serum calcium and phosphorus levels increased with time after Pb-Ac injection and the maximum values of calcium (17 mg%) were found after 1 h and of phosphorus (13.5 mg%) after 30 min. Both calcium and phosphorus levels reverted to the normal range after 12 h. The maximum net rates of increase of calcium and phosphorus were found immediately after Pb-Ac injection. At that time, deposition of lead at the calcifying sites of bone and incisor dentin was demonstrated by a histochemical examination. In other experiments the changes in the calcium and phosphorus contents in the medium after shaking bone powder in serum with Pb-Ac in an in vitro system were studied. It was confirmed that the calcium and phosphorus were displaced from the bone mineral, the extent of the displacement being correlated with the concentration of the Pb-Ac added to the medium, and that these displacements were very rapid reactions. These results suggest that hypercalcemia and hyperphosphatemia following Pb-Ac injection results from a direct action of lead on the bone mineral.
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  • 87
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    Calcified tissue international 23 (1977), S. 103-112 
    ISSN: 1432-0827
    Keywords: Albumin ; Polyvinylpyrrolidone ; Tissue fluid ; Bone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The passage of tissue fluid through cortical bone has been investigated using radioactively labelled macromolecules as markers. The results suggest that in the cortex of young rabbit femur the movement of tissue fluid is in the same net direction as blood, mainly from the endosteal to the periosteal surface. Some albumin is incorporated from extravascular tissue fluid into calcified matrix at sites of bone formation. Polyvinylpyrrolidone, average molecular weight 35,000 is able to pass through extravascular tissue fluid in bone but isnot incorporated into calcified matrix. In rabbits made vitamin D deficient, much less albumin is retained in regions of bone formation than is the case with controls. Albumin adsorbs to the surface of calcium phosphate precipitates and it is suggested that this mechanism may be mainly responsible for its incorporation into bone.
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  • 88
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    Calcified tissue international 23 (1977), S. 185-188 
    ISSN: 1432-0827
    Keywords: Matrix vesicles ; Bone ; Ultracrytomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Matrix vesicles were observed in femurs of 8-day-old chick embryos prepared by ultracryotomy. Some of the sections were subjected to ultramicroincineration. The unfixed tissues never came into contact with solutions, and thereby artifacts due to dissolution, redistribution, or rearrangement of the mineral constituents were avoided. In the osteoid, electron dense objects with the size and appearance of matrix vesicles were seen, although limiting membranes were not visible. After ultramicroincineration the vesicles were observed to contain small crystals and a less dense amorphous mineral material which may be the precursor of bone mineral. In addition, a ring of ash enclosed the crystalline and amorphous mineral and appeared to occupy the position of the vesicle membrane as seen in conventionally prepared material.
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  • 89
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    Calcified tissue international 24 (1977), S. 93-98 
    ISSN: 1432-0827
    Keywords: Magnesium ; Bone ; Mineral ; Chick embryo ; Organ culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Using bone organ culture techniques, three concentrations of magnesium were evaluated for their effects on the mineral mass of embryonic chick tibiae incubated for 3 days with or without a metabolic inhibitor (1 mM iodoacetic acid) added to the media. Varying the medium Mg level from 0.3 to 3.0 mM had little effect on the net increase in mineral in live bones (without the inhibitor), but in dead tibiae (with the inhibitor) there was a marked net decrease in mineral deposition with increasing Mg concentration. Bone Mg mass varied directly with the level of Mg in the medium regardless of whether or not the tibiae were inhibited. Responsiveness to parathyroid hormone (PTH) with regard to mineral loss and increased lactate production was not affected by Mg even in tibiae incubated in Mg-free media. However, PTH-treated bones cultured in Mg-free media had a significantly elevated Mg mass, suggesting that the hormone may have a Mg-conserving effect on bone during severe Mg deficiency. The findings of this study support the hypothesis that bone cells regulate the level of Mg to which newly forming mineral is exposed and that PTH-responsiveness in embryonic chick tibiae is not dependent on the ambient Mg concentration.
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  • 90
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    Calcified tissue international 22 (1977), S. 9-17 
    ISSN: 1432-0827
    Keywords: Bone ; Fluoride ; Calcium ; Phosphorus ; Mechanical Strength
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract Four groups of weanling rats were fed for 2 weeks on a diet sufficient or insufficient in calcium and/or phosphorus. Each group was divided into four subgroups which were offered distilled water supplemented with 0, 50, 75, or 150 ppm fluoride. High levels of fluoride in drinking water inhibited weight gain. This inhibition was less in rats deficient in phosphorus than when normal-phosphorus diets were offered. At a low level, fluoride was without any effect on bone ash, thickness of femoral cortical bone, and mechanical strength, as measured by maximal load, ultimate stress to breaking, and limit of elasticity. Modulus of elasticity was decreased. At higher levels fluoride tended to decrease most of these parameters, except in rats deprived of both calcium and phosphorus. The effect of fluoride was modified by lack of dietary calcium and/or phosphorus and appeared to be weaker in rats deficient in these nutrients. Lack of dietary calcium and/or phosphorus decreased bone strength more than did fluoride content of water and of bone mineral. Concentration of bone ash and thickness of femoral cortical bone were closely correlated with parameters of mechanical strength.
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  • 91
    ISSN: 1432-0827
    Keywords: Parathyroid hormone ; Plasma calcium ; Radiocalcium ; Bone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract Acute changes in plasma calcium and45Ca were studied in young adult male thyroparathyroidectomized (TPTX) rats injected with moderate doses of parathyroid hormone (PTH). For plasma calcium changes, comparison was made between rats fasted or fed prior to PTH injection. For plasma45Ca changes, the effect of the time of administration of the radionuclide was also studied; this included rats injected with PTH 1 h after radionuclide (“1 h45Ca”), 18 h later (“18 h45Ca”) and more than 6 days later (“6 day45Ca”). The results can be summarized as follows: (1) Plasma calcium changes were greater when PTH was injected into “fed” rather than into “fasted” rats. (2) PTH always produced a relative increase (compared to controls tested concurrently) in plasma45Ca concentrations. This increase was the same in the “1 h45Ca” and the “18 h45Ca” groups. (3) Plasma45Ca rose at least temporarily following PTH injection in the “18 h45Ca” group. (4) The45Ca rise following PTH was always greater in “fed” than in “fasted” groups. (5) Plasma45Ca specific activities (S.A.) tended to rise in the “6 day45Ca” group and to fall in the “18 h45Ca” group, following PTH injection. However, the45Ca S.A. was always higher in fed than fasted groups. (6) In a few experiments in which32P was injected with45Ca, specific activity changes in plasma45Ca following PTH injection werenot accompanied by similar changes in32P specific activity. These results could not be adequately explained by PTH effects on bone resorption, but the data supported the postulate that PTH controls plasma calcium concentrations by increasing transport of calcium through the osteocyte-lining cell (osteoblast) bone cell complex from the bone fluid compartment to the ECF.
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  • 92
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    Anatomy and embryology 151 (1977), S. 223-232 
    ISSN: 1432-0568
    Keywords: Bone ; Femur ; Density ; Hypergravity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Alterations in density of the femur of female Sprague-Dawley rats exposed to chronic centrifugation of 2.76 G for 810 days were studied. The density was measured by photon absorptiometry, using a 125I Profile Scanner. The photon absorption measurements were taken: (1) on bone sections from the midshaft of the femur in the anterior, posterior, medial and lateral cortex with the beam path parallel to the shaft axis, and (2) on the femur near the midshaft with the beam path perpendicular to the shaft axis. The latter were correlated with the cross-sectional area in the midshaft. Compared with femora of age-matched rats (age controls) and of rats having body masses comparable to the centrifuged group (weight controls), kept under earth gravity, the chronically centrifuged animals showed on average no significant differences in photon absorption (density) in the four positions in midshaft. The absorption measurements perpendicular to the shaft axis in all groups differe significantly on average. In the relationship to the cross-sectional area there are significant differences between the centrifuged group and the control groups. When cross-sections of equal size are compared, the density of the rat femora is clearly higher in the centrifuged animals than in the control groups. In contrast, the age and weight controls do not differ significantly in density. The results suggest that the increased stress in the rat femora due to centrifugation is reflected in an increased bone density.
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  • 93
    ISSN: 1432-0428
    Keywords: Insulin ; NSILA ; adipocytes ; diabetic rats ; insulin-receptor ; NSILA-receptor ; glucose transport ; glucose metabolism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Isolated fat cells from normal and streptozotocin-diabetic rats were compared with respect to metabolic indices (glucose-uptake, 3-0-methylglucose efflux) with and without stimulation by insulin and nonsuppressible insulin-like activity (NSILA). In addition, binding studies were carried out with these two hormones. Basal14C-glucose oxidation and incorporation into lipids was decreased in diabetic cells and their response to insulin and NSILA was greatly reduced. Basal efflux of 3-0-methylglucose from diabetic cells was somewhat faster than from normal cells. The response to insulin and NSILA was less than in normal cells and it was delayed. The apparent number of insulin binding sites as well as their affinity for insulin was increased in diabetic cells. In contrast, the apparent number of binding sites for NSILA was decreased in diabetic cells and their affinity for NSILA was increased. In normal cells insulin enhanced binding of125I-NSILA more markedly than in diabetic cells. These findings show that the rate-limiting step of impaired glucose metabolism (oxidation and lipogenesis) in diabetic fat cells is beyond the interaction of the hormone with the receptor. They suggest that the apparent number of hormone receptors (insulin, NSILA) on the cell membrane is regulated individually for each binding site.
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  • 94
    ISSN: 1432-0428
    Keywords: hGH deficiency ; Insulin response to IV glucagon ; Insulin response to glucose ; Insulin ; Children and adolescents ; Glucagon ; OGTT
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Six children and adolescents (aged from 2 6/12 to 16 years) with isolated hGH deficiency were subjected to a standard oral glucose tolerance test (OGTT) followed by the administration of IV glucagon at 180 mins. Three of them underwent a second test after several months of hGH therapy. Nine patients underwent a separate IV glucagon test and two of these patients had both tests. As controls served 14 endocrinologically normal children and adolescents, who underwent both tests. It was found that the patients with isolated hGH deficiency had lower basal plasma insulin and blood glucose levels and that their insulin response to IV glucagon even after oral glucose preloading was significantly lower than in the control group. This response was partially restored by several months of hGH treatment in the three patients tested. These findings are interpreted as further evidence for an insulinotrophic effect of hGH.
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  • 95
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    Diabetologia 13 (1977), S. 177-186 
    ISSN: 1432-0428
    Keywords: Insulin ; receptor binding ; diabetes ; Sepharose-coupled insulin ; PVP-coupled insulin ; Chinese hamster ; streptozotocin-diabetes ; liver membranes ; translation of hormone-receptor in-teraction ; 3′5′-AMP in fat cells ; catecholamines ; adenylate cyclase ; phosphodiesterase ; NSILA-S ; 3′5′-GMP ; calcium ; local anaesthetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
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  • 96
    ISSN: 1432-0428
    Keywords: Insulin ; glycogen ; amino acid ; alloxan diabetes ; cultured hepatocytes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of insulin on net glycogen synthesis and amino acid incorporation into protein were studied in cultured hepatocytes from adult normal and alloxan diabetic rats. Insulin stimulated glycogen synthesis in monolayer cells throughout a four day culture period and enhanced leucine incorporation into protein more effectively in normal cells with high glycogen levels than in cultured diabetic cells. These differences correlate well with the observed cellular ultrastructures which were maintained much better in the presence of insulin. Restoration of the morphological changes of alloxan diabetic hepatocytes to normal liver cell structures can be observed at any time during the culture period by giving insulin continuously.
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  • 97
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    Calcified tissue international 24 (1977), S. 143-149 
    ISSN: 1432-0827
    Keywords: Bone ; Periodontal ligament ; Bone resorption ; Aryl sulfatase ; Mineralization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The distribution of aryl sulfatase in the rat periodontal ligament was investigated by ultrastructural histochemistry. In the periodontal ligament aryl sulfatase was localized specifically in osteoclasts and in vicinal perivascular macrophages. Macrophages associated with bone formation did not stain. The authors interpret this specificity as a potential marker for osteoclast differentiation from macrophages — or as a further indication of the capacity of macrophages to modulate their enzymatic complement in response to the environment. To explain the absence of aryl sulfatase in areas of bone formation we suggest that different sulfate esters are mobilized from resorbing and mineralizing matrices, and that only the enzyme associated with bone resorption is histochemically detectable with the artificial substrates currently used.
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  • 98
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    Calcified tissue international 24 (1977), S. 243-248 
    ISSN: 1432-0827
    Keywords: Paracrystallinity ; Hydroxyapatite ; Bone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary X-ray diffraction patterns from oriented bone sections show that the crystalline apatite content of untreated mature cortical bovine bone has, in fact, a paracrystalline structure (i.e., no long range order). There is anisotropy in both lattice distortions and the sizes of the coherently diffracting domains. The paracrystalline mean distance fluctuations, (g) were found to be 1.5 (±0.1)% and 2.9 (±0.2)% for the basal and prism planes respectively, the corresponding paracrystalline sizes being 220 (±20) and 70 (±10) Å. The paracrystalline structure became more ordered above 600°C, suggesting the association of hydroxyl and possibly carbonate and other ions with the paracrystalline structure. The paracrystalline model for bone apatite helps explain anomalies between X-ray and electron microscope measurements of crystal size and also some of the biological functions of the crystalline apatite.
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  • 99
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    Calcified tissue international 23 (1977), S. 283-289 
    ISSN: 1432-0827
    Keywords: Bone ; Resorption ; Osteoclast ; Quantitation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The stimulation of bone resorption, assessed by the release of45Ca from prelabeled bones, was associated with an increase in number of osteoclasts per bone section in parathyroid hormone (PTH)-treated bones, but not in lipopolysaccharide (LPS)-treated bones. By contrast the number of nuclei per osteoclast increased following LPS treatment, but was not affected by PTH. LPS-treated bones had more multinucleated cells, some having as many as 27 nuclei per osteoclast. More osteoclasts were adjacent to the bone collar in bones treated with LPS or PTH than in control bones. In LPS-treated bones this area also contained the largest osteoclasts, as determined by the greatest number of nuclei per osteoclast. The results suggest that LPS and PTH stimulate osteoclastic resorption by different mechanisms.
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  • 100
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    Calcified tissue international 23 (1977), S. 303-305 
    ISSN: 1432-0827
    Keywords: Albumin ; Bone ; Hydroxyapatite ; Plasma protein
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The extractability of125I-labelled plasma albumin from bone pieces and from powdered bone has been compared after both in vivo and in vitro incorporation. The results show that albumin is more readily extracted from bone pieces than from bone powder which implies that tissue disruption exposes additional protein adsorption sites. It is suggested that incorporation of plasma albumin into calcified matrix during bone formation occurs mainly as a result of its strong interaction with bone mineral.
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