摘要:

AbstractUltrastructural localization of carbonic anhydrase was determined by applying Hansson's histochemical method to glutaraldehyde‐fixed frozen sections of guinea pig peritoneal polymorphonuclear leukocytes (PMNs) and lysosomes isolated from rat liver tissue after the animal had been injected with Triton WR‐1339. A positive histochemical reaction for carbonic anhydrase in PMNs was found in the matrix of lysosomes. After PMNs phagocytized polystyrene latex particles or emulsified paraffin oil droplets, a positive reactivity for carbonic anhydrase was found in the space between the lysosomal membrane and the particle. Liver lysosomes also revealed positive carbonic anhydrase histochemical reactivity. To confirm the histochemical reaction, indirect immunoferritin labeling was conducted with rabbit antibody to human red blood cell carbonic anhydrase C on glutaraldehyde‐fixed, freezethawed human PMNs. Immunolabeling was observed in lysosomes. These results suggest that carbonic anhydrase is a constituent of lysosomes of PMNs and liver

ISSN:0003-276X    

DOI:10.1002/ar.1092110102

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractThe ability of PGE2to stimulate bone resorption in vitro and in vivo is well established but the effects of this compound on bone formation are still controversial. Recent clinical reports have suggested that long‐term infusion of PGE in infants with cyanotic heart diseases led to a stimulation of periosteal bone formation and to hyperostosis.In the present report, we describe the effects of PGE2(10−5M) in bone organ cultures on bone resorption, measured by the release of45Calcium and the number of osteoclasts in sections of cultured bones, and bone volume, by measuring separately medullary and cortical areas. PGE2induced a marked increase in45Ca release and in cortical and medullary osteoclast numbers over 4 days in vitro; despite this increase in bone resorption, cortical bone volume remained constant, indicating a parallel increase in bone resorption and formation at this site. Morphological and quantitative data demonstrated a higher extent of osteoblastic surface along the periosteum of PGE2‐treated bones when compared with control cultures. Medullary bone volume, on the other hand, decreased sharply during the culture period, demonstrating a lack of parallel increase in bone formation at this site.It is concluded that, under these experimental conditions, prostaglandin E2stimulated both resorption and formation along the periosteum and only bone resorption along the endosteum of the cultured bones. The overall effect of PGE2on bone as a whole, however, was net bone

ISSN:0003-276X    

DOI:10.1002/ar.1092110103

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractThe effect of adriamycin on rat incisor was investigated 1 day after administration. Rats were injected intravenously with adriamycin at a dose of 5 mg/kg body weight and sacrificed by perfusion with a 2.5% phosphate buffered glutaraldehyde solution. The principal effect of the drug on the incisor was the production of cell degeneration. This was extensive in the apical region, being present along the entire periphery of the dental papilla. In sections examined more incisally, cell degeneration gradually disappeared from the labial portion of the incisor but was present in the lingual portion. This degeneration of cells was not present at the site where mature odontoblasts had differentiated on the lingual surface of the pulp chamber. It appears that the affected cells were early preodontoblasts and the precursors of preodontoblasts. However, as these cells became more differentiated they apparently became more resistant to the drug's effect.

ISSN:0003-276X    

DOI:10.1002/ar.1092110104

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractThe external genitalia of four adult female pygmy chimpanzees(Pan paniscus)were examined during a 2‐year period. It was found that the labia majora are retained in adults of this species and that, when tumescent, the labia minora effectively relocate the frenulum and clitoris so that they point anteriorly between the thighs. When detumescent, the configuration of the labia minora and clitoris resembles that of immature common chimpanzees(P. troglodytes). It is suggested that the simple, structural relocation of the clitoris from the normal condition noted in adultP. troglodytesmakes possible the homosexual, intergenital rubbing observed inP. paniscus, when ventroventral juxtaposition of the individuals permits eye‐to‐eye contact. In addition, this change probably increases sexual stimulation of the female during heterosexual, ventroventral copulations. The possibility of intense, face‐to‐face sexual interactions has been achieved byP. paniscuswithout the evolution of bipedalism and the consequent reorientation of the genitalia seen inHom

ISSN:0003-276X    

DOI:10.1002/ar.1092110105

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractSince previous studies have shown that an active pineal gland exerts an inhibitory effect on circulating levels of thyroxin in the Syrian hamster, a study was conducted to determine whether the histology and ultrastructure of the thyroid gland supported the conclusions drawn from the hormone data. The ultrastructure of thyroid glands of blinded male Syrian hamsters was compared to that of intact controls kept under a 14L/10D photoperiod, to that of blinded hamsters also pinealectomized, and to that of blinded hamsters receiving 80 μg/ml of melatonin in the drinking water. Serum thyroxin (T4) and serum thyrotropin (TSH) concentrations were determined by radioimmunoassay. After 10 weeks serum thyroxin concentrations were less than 50% of controls and concentrations were significantly reduced. EM examination revealed that blinded hamsters had an increased number of follicular cells with flattened epithelium and nondilated endoplasmic reticulum compared to intact controls. In blinded hamsters that were pinealectomized or treated with melatonin in the drinking water, the ultrastructure of the thyroid was not different from controls and serum thyroxin concentrations were restored to near normal. These ultrastructural data support the conclusion that the pineal gland is required to obtain inhibition of the pituitary‐thyroid axis in blinded hamsters and that melatonin has a counter‐inhibitory effect when administered via the drinking w

ISSN:0003-276X    

DOI:10.1002/ar.1092110106

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractIn order to elucidate the functional significance of somatostatin in thyroid C cells, the alterations of immunoreactive somatostatin in the cells were investigated under various experimental conditions, i.e., hypercalcemia, hypocalcemia, and antithyroid drug treatment. Guinea pigs and rabbits, in which almost all C cells reveal the intense immunoreaction for somatostatin in addition to calcitonin, were used as experimental animals. After chronically induced hypercalcemia, somatostatin immunoreactivity conspicuously diminished coinciding with the decrease of calcitonin; somatostatin as well as calcitonin was responsive to induced hypercalcemia. After hypocalcemic tetany induced by injection ofEscherichia coliLasparaginase, C cells exhibited very intense immunoreactions for both calcitonin and somatostatin. After chronic treatment of ethylenethiourea, immunoreaction of somatostatin in C cells was the same as that of calcitonin. That is, when immunoreactivity for calcitonin remained unchanged, immunoreactivity for somatostatin was also intensive. However, when immunoreaction of calcitonin became very weak, the reaction of somatostatin was also weak. Thus, in all experimental conditions examined the alterations of immunoreactive somatostatin in C cells completely coincided with those of calcitonin. It seems likely that somatostatin in thyroid C cells exerts the synergistic effect on calcitonin action.

ISSN:0003-276X    

DOI:10.1002/ar.1092110107

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractThe distribution of the intermediate filament protein vimentin in peripheral lymphoid tissues was determined using a monoclonal antibody. Frozen sections of tissue were stained using an avidin‐biotin immunoperoxidase method. The antibody stained endothelial cells in spleen, lymph node, and tonsil. Unusual rod‐like structures were revealed in the sinusoid‐lining cells of the spleen. A variety of reticulum cells was detected, including fibroblastic reticulum cells, histiocytic reticulum cells (tingible body macrophages), and splenic marginal zone macrophages. Very few lymphocytes were immunoreactive. Only weak cytoplasmic immunoreactivity was observed in lymphocytes of the periarteriolar lymphocyte sheath of the spleen. The monoclonal antibody employed appears to be of limited usefulness in detecting normal lymphocytes, but is strongly reactive with endothelial structures and some types of reticulum

ISSN:0003-276X    

DOI:10.1002/ar.1092110108

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractMouse blastocysts were cultured in hanging drops for up to 6 days in order to study development under conditions that avoid the distortion of embryos typically seen when they are allowed to attach to a glass or plastic surface. The survival rate of embryos in hanging drops was equal to that of embryos attached to culture dishes and superior to that of embryos suspended in gyrating flasks. Development of the embryonic portion was similar to that in vivo and on culture dishes but slower than in vivo; the egg cylinder stage was reached after 8–10 equivalent gestation days (4 to 6 days in culture), while that stage is reached at 5.5 to 6 days in vivo. The trophectoderm, however, developed in a unique manner. The cells migrated away from the inner cell mass (ICM), similar to embryos on a culture dish, but without a surface on which to spread they clustered distal to the ICM. In vivo, trophectoderm remained covering the ICM. By 5 days in hanging drop culture the embryos had developed a segmented appearance with trophoblast giant cells at the abembryonic pole, extraembryonic cells not covered by vacuolated endoderm in the central region, and embryonic endoderm surrounding a developing proamniotic cavity in embryonic ectoderm at the embryonic pole. These observations suggest that the trophectoderm is able to follow a developmental program independent of that in the embryonic portion and that its behavior is dominated by the different adhesive properties of the trophoblastic and embryonic cell

ISSN:0003-276X    

DOI:10.1002/ar.1092110109

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractCephalic neural crest (NC) cells enter a cell‐free space (CFS) that contains an abundant extracellular matrix (ECM). Numerous in vitro investigations have shown that extracellular matrices can influence cellular activities including NC cell migration. However, little is known about the actual ECM composition of the CFS in vivo, how the components are distributed, or the nature of NC cell interactions with the CFS matrix. Using ultrastructural, autoradiographic, and histochemical techniques we analyzed the composition and spatial organization of the ECM found in the CFS and its interaction with mesencephalic NC cells. We have found that a specific distribution of glycoproteins and sulfated polyanions existed within the CFS prior to the translocation of NC cells and that this ECM was modified in areas occupied by NC. The interaction between the ECM components and the NC cells was not the same for all NC cells in the population. Subpopulations of the NC cell sheet became associated with ECM of the ectoderm (basal lamina) while other NC cells became associated with the ECM of the CFS. Trailing NC cells (NC cells that emerge after the initial appearance of NC cells) encountered a modified ECM due to extensive matrix modifications by the passage of the initial NC cell populatio

ISSN:0003-276X    

DOI:10.1002/ar.1092110110

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractIn goldfish new rods are continuously added to the entire retina at a rate that assures stable rod density, while the densities of other neurons decrease. Theb1bipolar, known to contact every rod within its dendritic domain, was used to determine the fate of these newly formed rods.Golgi‐stainedb1bipolars were sectioned serially at 0.5 μm in the plane of the receptor terminals and reconstructions of their rod and cone contacts were prepared from camera lucida drawings.The newly formed rods are accommodated within the dendritic trees of alreadyformedb1bipolars at a rate of about one new rod synapse/bipolar/month. During growth from about 6 months to 5 years of age the number of synapses onto eachb1bipolar increases by 50%. Concomitantly the dendritic tree area increases by about 50%, and the density of rod‐b1synapses remains constant at about one synapse/11 μm2.Assuming a dendritic coverage factor of 1, theb1bipolars will contact every retinal rod. The numbers of cones contacted and not contacted do not significantly change. The overall dimensions ofb1bipolars increase with retinal growth and new branches are added to their dendritic trees.These observations show that new rods added to adult goldfish retina form synapses with old bipolars. Some functional inferences are also

ISSN:0003-276X    

DOI:10.1002/ar.1092110111

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY