摘要:

AbstractBackground: Gravin, a novel, high molecular weight, intra‐cellular protein, is expressed in endothelial cells and several other adherent cell types in vitro. To gain insights into its function, we examined the distribution of gravin in tissues.Methods: Affinity‐purified polyclonal and monoclonal antibodies were raised against a bacterial fusion protein corresponding to the carboxyl terminus of gravin and against affinity‐isolated gravin. The specificity of the antibodies was characterized by immunoblotting bacterial, cell, and tissue extracts. The characterized antibodies were used to localize gravin in baboon tissue sections by immunocytochemistry and immunofluorescence microscopy.Results: The antibodies specifically immunoblotted the fusion protein and recognized either a band at 250 kDa or a doublet at 300 kDa on immunoblots of MG63 cells, HEL cells stimulated with phorbol ester, and several baboon tissues. In tissue sections, cell types that express gravin included fibroblasts, components of the peripheral and central nervous system, the adrenal medulla, the somatic layer of Bowman's capsule, cells associated with the glomerulus, and smooth muscle of certain organs. In contrast, most epithelia and all endothelia, with the exception of endothelia of the hepatic sinusoids and intestinal lacteals, lacked gravin. Levels of gravin mRNA expression in stimulated HEL cells increased dramatically when cells were stimulated in the presence of cycloheximide, suggesting that gravin expression may be partly regulated by protein‐dependent mRNA catabolism.Conclusions: These data indicate that gravin expression is regulated in endothelial cells, possibly through protein‐dependent mRNA catabolism. The strong expression of gravin in fibroblasts, neurons, and cells derived from neural crest in vivo and in adherent cells in vitro further suggests that this protein may play role in the modulation of cell motility and adhesion. © 1994 Wiley

ISSN:0003-276X    

DOI:10.1002/ar.1092390302

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

年代:1994

数据来源: WILEY

摘要:

AbstractBackground: Ovariectomy (OVX) and immobilization (IMM) in rats are useful models of osteopenia, replicating some aspects of osteoporosis in humans. The purpose of this study was to compare changes in cancellous bone after OVX and/or IMM.Methods: Differences in cancellous bone were determined at 6 and 12 weeks after OVX or IMM. Comparisons were also made when rats were ovariectomized or immobilized for 6 weeks and then immobilized (OVX/IMM) and ovariectomized (IMM/OVX), respectively, for 6 more weeks. The femurs were used to determine bone mineral content (BMC) using single photon absorptiometry (SPA) and for scanning electron microscopy (SEM). Tibias were collected for microradiography, image analysis, and histomorphometry of metaphyseal cancellous bone.Results: Six and 12 weeks after OVX, there was less cancellous bone mass, compared with controls, as indicated by SPA, SEM, microradiography, image analyses, and histomorphometry. Bone was lost primarily from the central metaphyseal regions in the OVX animals, whereas the loss occurred throughout the metaphyses in the IMM animals. There were more rodlike bone spicules and fewer platelike trabecule in the OVX and IMM groups compared with controls. Differences in the structural aspects of the cancellous bone, including differences in the types of bone struts and marrow star volumes, indicated less trabecular connectivity and greater trabecular separation in the OVX and IMM animals, compared with controls. Endochondral growth indices in the IMM groups tended to be less, whereas the OVX groups tended to be greater than controls. Cancellous bone formation rates were generally greater in the OVX groups but less in the IMM groups compared with controls. Osteoclastic resorption surfaces were substantially elevated in the IMM and OVX groups, particularly the IMM groups. Changes reflecting OVX and IMM, independently, were apparent in the OVX/IMM and IMM/OVX groups and indices of osteopenia were different from controls, including less bone mass, trabecular connectivity, and greater trabecular separation, bone turnover rates, and osteoclastic surface.Conclusions: These results demonstrate differences in the osteopenic changes that occur in cancellous bone following OVX or IMM. The changes were generally more dramatic in the IMM than in the OVX animals. When OVX and IMM were applied in combination, the osteopenic changes are particularly severe, emphasizing the importance of mechanical usage even with a deficiency of gonadal hormones. © 1994 Wiley‐Liss, I

ISSN:0003-276X    

DOI:10.1002/ar.1092390303

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

年代:1994

数据来源: WILEY

摘要:

AbstractBackground: It has been suggested that within the growth plate, the final volume and shape of hypertrophic chondrocytes are important variables in determining the rate of longitudinal bone growth. To better understand the organization and regulation of chondrocytic hypertrophy as related to longitudinal bone growth, the beginning and end, and the location and magnitude of chondrocytic volume and shape changes during the hypertrophic process were defined in the proximal tibial growth plate of 35‐day‐old rats.Methods: In this study we used two different approaches, a stereological analysis of chondrocytes in unbiasedly defined, narrow growth plate strata, and a serial section reconstruction and measurement of individual cells. In both experiments chondrocytes were preserved using optimal chemical fixation. Proliferating chondrocytes were identified using bromodeoxyruidine labelling, and the rat of longitudinal bone growth was determined using oxytetracycline labelling.Results: In both studies, immediately following cell division in the proliferative zone, chondrocytic volume gradually increased toward the midpoint of the growth plate. During this phase of about 30 hours, approximately 20% of the final cell volume was obtained. During the following 20 hours the remaining 80% was acquired. The estimatedrateof cell volume increased changed from approximately 50 μm3/hr during the first 30 hours to about 800 μm3/hr during the last 20 hours. The increase in cell volume resulted in an increase in both the vertical and the horizontal chondrocytic diameters. Cell parameters did not change during the final five hours of the maturation process.Conclusions: In this study we demonstrated that chondrocytic enlargement starts immediately following cell division in the proliferative zone, and that chondrocytic enlargement consists of two morphologically distinguishable phases. The transition point between the first and the second phase of chondrocytic enlargement corresponded with the junction between the proliferative zone and the maturation zone. © 1994 Wiley‐L

ISSN:0003-276X    

DOI:10.1002/ar.1092390304

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

年代:1994

数据来源: WILEY

摘要:

AbstractBackground: The isolation of cells termed type 5 from the bovine corpus luteum was recently reported. Since these cells were reminiscent of immature granulosa cells, their morphological and functional relationship requires further investigation in view of the novel concept of corpus luteum growth. It suggests that putative stem cells of unknown origin supply the pool of small luteal cells.Methods: Bovine corpora lutea were mechanically dispersed, cell suspensions separated over a Percoll® density gradient, and type 5 cells purified by colony transfer. Granulosa cells were harvested from small‐sized antral follicles. Observations were carried out at the light and electron microscopical level. 3β‐Hydroxy‐steroid‐dehydrogenase was localized histochemically in addition to intracellular lipid droplets stained with nile red. Immunolocalization was used to study Factor VIII antigen presence, the architecture of the cytoskeleton, as well as the occurrence of neuronal cell adhesion molecules, and of neuronal cadherin‐like molecules. The uptake of acetylated low density lipoprotein was examined. As for progesterone concentration, cells were seeded at low density on day zero. Cell numbers and progesterone levels of supernatants were determined on day 10 in culture.Results and Conclusions: Type 5 cells behaved morphologically like immature granulosa cells, yet the total cell number and the progesterone concentration differed for type 5 cells compared to granulosa cells. The addition of LH had no influence on the progesterone concentration as seen for either type 5 cells or for granulosa cells. It is concluded that type 5 cells, which were originally mistaken for microvascular endothelial cells, display similarities with immature granulosa cells. Type 5 cells may play a role in renewal of luteal cells. © 1994 Wil

ISSN:0003-276X    

DOI:10.1002/ar.1092390305

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

年代:1994

数据来源: WILEY

摘要:

AbstractBackground: The microvascular pattern of the duodenal papilla is unknown. Since the duodenal papilla is located in the transition zone between the stomach and duodenum, and because it regulates bile transfer into the duodenum, a particular microangioarchitecture can be expected. Therefore, we examined the microvasculature of the papilla using guinea pigs as a model.Methods: The microvascularization of the duodenal papilla and common bile duct was studied in 26 adult guinea pigs (Cavia porcellus), using scanning electron microscopy of microvascular corrosion casts and critical point dried specimens, and light microscopy of tissue sections.Results: The duodenal papilla is located in the cranial portion of the duodenum, approximately 5 mm beyond the pyloric valve. At the most luminal aspect of the cast papilla, ring‐shaped capillaries, resembling those of the cast gastric mucosa, are present. Deeper parts of the papilla are provided with villi. Subepithelial capillaries of the papilla are 15 μm thick in average. These capillaries have a dual blood supply either via the straight long arterioles arising from the submucosa or by the pericryptal capillaries. The common bile duct comprises numerous mucoid glands with their pits surrounded by ring‐shaped capillaries in corresponding casts.Conclusions: The special arrangement of different capillary patterns, together with their luminal size and the dual blood supply, favor their protective role from the gastric chyme. © 1994 Wiley‐Li

ISSN:0003-276X    

DOI:10.1002/ar.1092390306

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

年代:1994

数据来源: WILEY

摘要:

AbstractBackground: It was hypothesized that the evolution towards the senile lung is progressive, being initiated in the adult stage; and for this reason changes similar to those described in the senile lung can be detected in the lungs of middle‐aged rats. To test the hypothesis, the following design was used. The lungs of two groups of rats, adult (mean age of 16 weeks) and middle‐aged (mean age of 56 weeks) were morphometrically compared.Methods: Thirty‐one Wistar rats were used for the study; their lungs were processed histologically. The microscopic fields were analysed in a computer, and 20 variables were quantified. These were grouped into (a) variables which describe the shape and size of the distal airspace, (b) variables which describe the distal lung tissue, and (c) variables which describe elastic fibers. The results were statistically compared: correlation tests were carried out, and the specificity, sensitivity, and misclassification indices were calculated.Results: All the results of the variables which define the size of the air‐spaces were found to be significantly higher (P<0.0001) in the middle‐aged animals; the results obtained when the lung tissue was quantified directly from the histological section suggested a loss of tissue in the middle‐aged animals. However, when these data were converted into absolute values, no loss was indicated in the total lung tissue. The values of the variables which describe the elastic fiber were found to have increased significantly (P<0.0001) in the middle‐aged animals. The misclassification index was found to be lower than 10% in six variables and between 10% and 20% in four.Conclusion: The low misclassification indices found lead us to consider that our morphometric method is ideal for distringuishing the lungs of the two groups of animals used. The results of the quantification of the variables show that the middle‐aged animals exhibit simple enlargement of the distal airspaces, without tissue loss, which coincides with the current definition of the senile lung. © 1994

ISSN:0003-276X    

DOI:10.1002/ar.1092390307

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

年代:1994

数据来源: WILEY

摘要:

AbstractBackground: The lymphatics of Peyer's patches disseminate immunological information from the gut and thus play a key role in protection of the body against environmental pathogens. The aim of this project was to describe the lymphatic pathways of these Peyer's patches in pigs, and the mucosal intercellular spaces which lead to these lymphatics.Methods: Ileal tissue from living or freshly killed pigs was examined by light microscopy or electron microscopy, or was injected with Mercox (CL‐2B, Japan Vilene Hospital, Tokyo) for scanning electron microscopy of corrosion casts.Results: Intercellular fluid between intestinal epithelial cells passes through pores in the basal lamina to mix with that in the intercellular spaces and prelymphatic intercellular channels of the lamina propria and follicle domes. From there, lymph enters lacteals in the villi, or a branching network of vessels within the lamina propria. Small lymphatics penetrate the muscularis mucosae and are continuous with (1) lymphatic vessels which pass directly to the deep submucosa between follicles, or (2) lymphatic sinuses which lie adjacent to the follicles. This differes from the situation in sheep and rabbits. Basal lymphatics beneath the follicles convey lymph to vessels which leave the surface at the serosa.Conclusion: The differences in the structure and arrangement of the lymphatics of Peyer's patches between pigs, sheep, and rabbits will require further investigation to determine if such variation between species has an effect on the distribution of immune products to effector sites. © 1994 Wiley‐Liss,

ISSN:0003-276X    

DOI:10.1002/ar.1092390308

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

年代:1994

数据来源: WILEY

摘要:

AbstractBackground: Macrophage precursors are present early in embryonic life, being demonstrable in placental and embryonic connective tissues of rats at the neurula stage and as potential macrophagees in the brain, liver, and lungs near the onset of organogenesis. We examined the development of macrophages in the heart and the possibility that they initially appear at sites of programmed cell death (apoptosis).Methods: Precursors were recognized by the binding of peroxidase‐coupledGriffonia simplicifoliaisolectin B4(GSA) on the cell membrane. Their capacity for conversion into macrophages was assayed in organ cultures; confirmation of the progeny as bona fide macrophages was obtained from their responses to particle exposure and macrophage colony‐stimulating factor (M‐CSF).Results:GSA + cells were first seen on gestational day 12 (4 mm embryos) as 2–3 cycling, nonvacuolated cells located in cardiac tissue outside the blood vessels. This population increased to ∼︁ 12 cells by day 14 (9 mm embryos). Two‐thirds were distributed along the bulbus cordis in the jellylike endocardium and a more densely cellular connective tissue closer to the aortic arches where apoptotic sites are expected to develop. Such sites were not found in serial glycol methacrylate sections through our 14‐day specimens, although in whole heart explants of this age an area of necrosis developed along the prospective line of bulbar endocardial fusion on the second day of organ culturing, and by then macrophages were fairly abundant. Organ culturing of 13‐day embryonic hearts also yielded large, highly vacuolated, GSA + mononuclear phagocytes. After a few days in culture most of the macrophages migrated onto the medium where they formed a tight corona of cells about the explants. They readily ingested iron oxide particles and concentrated supravitally administered neutral red in their vacuoles. Macrophages from 14‐day cultures exposed to M‐CSF developed significantly larger coronas than macrophages from explants grown in serum‐rich control medium (p<0.001). In the presence of cytokines, moreover, these cardiac macrophages survived as many as 100 (92 “postnatal”) days.Conclusions: Macrophage precursors first appear in embryonic rat hearts well before they are needed to clear debris generated by programmed cell death and are capable of rapid conversion into outright phagocytic cells as early as the 13th prenatal

ISSN:0003-276X    

DOI:10.1002/ar.1092390309

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

年代:1994

数据来源: WILEY

摘要:

AbstractBackground: Chick coronary arteries orginate as penetrating channels from a subepithelial peritruncal ring into the wall of all three aortic coronary sinuses. Two of these capillaries develop a muscular wall and become the definitive coronary arteries. Since cardiac neural crest (CNC) contributes ectomesenchyme to the tunica media (TM) of the aortic arch vessels, we wished to learn if the CNC also contributes to the media of the coronary arteries and if CNC plays an inductive role in determining the site of aortic penetrations and influences which channels persist to hatching.Methods: Quail‐to‐chick chimeras were made by bilaterally removing the chick CNC and replacing it with quail CNC. The chimeras and unoperated controls were collected on embryonic days (ED) 7–18, fixed in Carnoy's fixative, serially sectioned, stained with Feulgen‐Rossenbeck stain, and analyzed. Several ED 18 controls and chimeras were also stained with Gomori's trichrome stain, or labeled with antineurofilament or antivascular smooth muscle alpha actin.Results: The TM of the coronary arteries and the aortic coronary sinuses did not consist of CNC cells. The media of the surviving coronary arteries was disrupted by clusters of CNC cells scattered in the wall of the base of the coronary artery on ED 14 and 18. Persisting coronary arteries were always associated with large neural crest‐derived parasympathetic ganglia near their origin. Branches from parasympathetic nerves entered the base of the coronary arteries where the clusters of neural crest cells were located. Quail cells were also associated with tiny vessels exiting the ostia of the coronary arteries and traveling in the outer aortic wall. Labeling with antibodies confirmed a disruption of the TM at the base of the coronary arteries, and showed innervated clusters of quail cells in the disrupted part of the TM.Conclusion: Although the TM of the coronary arteries and the aortic coronary sinuses contained no CNC cells, clusters of innervated quail cells disrupted the TM at the base of the coronary arteries. CNC does not appear to induce capillary penetration direclty; however, the exclusive association of CNC‐derived parasympathetic ganglia and nerves with persisting coronary arteries suggests that the presence of parasympathetic ganglia is essential to the survival of the definitive coronary arteries. CNC cells may also be associated with the development of the aortic vasa vasorum. © 1994 Wil

ISSN:0003-276X    

DOI:10.1002/ar.1092390310

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

年代:1994

数据来源: WILEY

摘要:

AbstractBackground: The pathophysiology of chronic supraspinatus tendinitis is not fully understood. This may be due to the scarcity of experimental studies on this issue.Methods: In search for a system suitable for experimental analysis, the present study describes the relevant gross anatomy of the rat shoulder region (dissection), and examines the fiber composition of relevant suprascapular nerve branches (electron microscopy, selective denervations).Results: The rat shoulder region is similar to the human shoulder in terms of gross anatomy. The average suprascapular nerve (SSC) is derived mainly from the spinal cord segment C5 and contains 3,435 axons, 74% of which are unmyelinated. The supraspinatus branch (SSP) contains 627 fibers. Of the SSP fibers, 52% are myelinated, including 32% motor and 20% sensory axons. Of the C‐fibers in the SSP 16% are sympathetic efferents and 32% are sensory. Many of the latter disappear after neonatal capsaicin treatment. The SSC emits a subacromial articular branch (ART), with some 260 axons, about 90% of which are unmyelinated. The myelinated ART fibers are sensory, and of the unmyelinated ones about 24% are sympathetic efferents and 66% are afferents. The latter resist neonatal capsaicin treatment.Conclusions: In view of the anatomy of the supraspinatus muscle, of the subacromial space, and of relevant nerves, the rat shoulder should be appropriate for experimental studies on inflammatory conditions in the subacromial space. © 1994 Wiley‐Liss,

ISSN:0003-276X    

DOI:10.1002/ar.1092390311

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

年代:1994

数据来源: WILEY