摘要:

The purpose of this study was to subject groups of hypophysectomized male and female rats each to a simulated specific 10% increase in body weight, to a maximum of a doubling of body weight, in order to study the effects of quantified, increased, intermittent, compressive forces on limb bone growth. Chronic centrifugation was employed. 21-day-old Sprague-Dawley rats were used. After 60 days of centrifugation, the rats were sacrificed. The humerus, radius, ulna, femur and tibia were removed from each animal, cleared of all soft tissues, and the bone lengths measured on Helios calipers with an accuracy of 1/20 mm. The data were corrected for differences due to individual body weight by dividing bone lengths by the cube root of the body weight of the same animal. Tukey’s studentized multiple-range test was performed to identify aggregations (sets) of force groups between which there are significant differences. The data suggest that the simulated increases in body weight, within the range used for this study, enhance bone growth in hypophysectomized female and male rats similarly – hypophysectomy being a condition known to inhibit bone gro

ISSN:1422-6405    

DOI:10.1159/000145932

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

The purpose of this study was to subject groups of male rats each to a specific 10% simulated increase in body weight, ranging from 1.1 to 2.0 g. Constant centrifugation was employed. After 30 and 60 days, rats were sacrificed and perfused with 10% BNF. The humerus, radius, ulna, femur, and tibia were removed, cleared of all soft tissues, weighed, decalcified with EDTA, and reweighed. Bone mineral content (BMC) was determined using the formula: [(Wu – Wd) ÷ Wu] × 100. Tukey’s multiple range test was used. The data suggest that male weanling rats subjected to simulated increases in body weight, within the range used in this study, undergo enhanced BMC, a bimodal curve describing the relationship between BMC and simulated increases in body w

ISSN:1422-6405    

DOI:10.1159/000145933

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

The purpose of this study was to subject groups of newborn male and female Sprague-Dawley rats each to a specific 10% simulated increase in body weight, to a maximum of a doubling of body weight, to study the effects of quantified, increased, intermittent, compressive forces on limb bone growth. Chronic centrifugation was employed. After 90 days of centrifugation the rats were sacrificed. The humerus, radius, ulna, femur, and tibia were removed from each animal, cleared of all soft tissues, measured and weighed. Tukey’s Studentized multiple range test was performed to identify aggregations (sets) of force groups between which there are significant differences. The data suggest that newborn male and female rats subjected to simulated increases in body weight, within the range used for this study, undergo enhanced general body growth and limb bone growt

ISSN:1422-6405    

DOI:10.1159/000145934

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

Rabbit uterine epithelium was examined by electron microscopy after treatment with two proteinase inhibitors, aprotinin and antipain, administered as a single injection. Both compounds had similar effects, those of antipain being slighter. After treatment, uterine epithelium showed an increased number of very enlarged cells. Lateral cell membranes were often brocken off; basal cell membrane and basement membrane integrities are impaired. The possible interference of the system proteinase-proteinase inhibitors with the implantation process was discussed.

ISSN:1422-6405    

DOI:10.1159/000145935

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

We studied 20 garden dormouses (Eliomys quercinus), 10 of which had hibernated. The renal tissue was fixed in Bouin’s fluid, embedded in paraffin and sectioned at 7 μm; the sections were stained with azocarmin. These preparations were studied with an optical microscope (Leitz SM-Lux). Hibernation causes an increase in the corpuscular, glomerular and Bowman capsular areas. We thought that this statistically significant increase in the size of the corpuscular structures might be due to the glomerular blood stasis and larger flow of plasma ultrafiltrated towards the capsular space, because of an intense vasoconstriction of the efferent arteriole; this vasoconstriction is due to sympathetic stimulation and renin hypersecreti

ISSN:1422-6405    

DOI:10.1159/000145936

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

It is generally accepted that chromosomes are not visible in interphase except in certain diptera, amphibia and rare unicellular organisms where they are represented by polytene, giant chromosomes. Such structures are exemplified by cells in which growth is evident by increase in size while the polytene structures increase in size rather than in number. These giant chromosomes are active metabolically, synthesizing mRNA and causing increasing activity in the corresponding cells. Experimental procedures leading to increased activity in neurones were accompanied by the appearance of nuclear inclusions which behaved very much like the polytene chromosomes metabolically and, as a result, an attempt was made to determine whether they had similar chemical behavior. This proved to be demonstrable and so it is concluded that the Roncoroni body represents a metabolically active interphase chromosomal segment and may be used as a sign of such activity.

ISSN:1422-6405    

DOI:10.1159/000145937

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

The cross-sectional areas of the masseter, temporalis, medial pterygoid and lateral pterygoid muscles were determined by means of computer tomography in 16 male subjects with healthy dentitions. The physiological cross-section (PCS) of these muscles was predicted from the previously determined relationship between PCS and scan cross-sections. In our subjects, mean total PCS of the jaw muscles was twice as high as in cadavers with few natural teeth. The average distribution of total PCS over the four muscles was the same in the two groups. There was considerable individual variation. Strong correlations in cross-sectional area were only found between the masseter and medial pterygoid muscles. Variation in PCS of these two muscles determines 80% of the variation in combined cross-sectional area.

ISSN:1422-6405    

DOI:10.1159/000145938

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

The development of the knee joint and synovial membrane in Wistar rats was studied from the 13th fetal day until adulthood by means of light microscopy, transmission electron microscopy and scanning electron microscopy. Using acid phosphatase and peroxidase methods, the different cell types of synovial membrane could be identified.

ISSN:1422-6405    

DOI:10.1159/000145939

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

The caudal heart is traditionally regarded as part of the lymphatic vessel system in fish. Recently, however, a secondary blood vessel system has been demonstrated in this class of vertebrates, while the existence of lymphatics was questioned. In corrosion casts of the secondary system it is shown that the caudal heart functions as a venous pump in the secondary circulation. Contrary to current views fish do not have true lymphatic vessels. Theories on the phylogeny of lymphatics therefore should be revised accordingly.

ISSN:1422-6405    

DOI:10.1159/000145940

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

Ultrastructural changes of the parathyroid glands of starved mice were examined. The parathyroid glands of the starved mice showed a decrease in the volume of Golgi complexes and storage granules and an increase in the volume of lipid droplets, and contained more heterogeneously dense bodies and multivesicular bodies compared with that of the control mice. In addition, the volume of mitochondria, cisternae of granular endoplasmic reticulum and secretory granules and the number of prosecretory granules appeared to be decreased compared to those of the control mice. Myelin-like structures were observed in the parathyroid glands of the starved mice. The results of our study provide support for the hypothesis that starvation exerts an inhibitory influence not only on the synthesis but also on release of parathyroid hormone.

ISSN:1422-6405    

DOI:10.1159/000145941

出版商:S. Karger AG    

年代:1985

数据来源: Karger