ISSN:0003-276X    

DOI:10.1002/ar.1092340216

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

年代:1992

数据来源: WILEY

摘要:

AbstractFibroblasts cultured within free‐floating collagen gels can bind to and reorganize the surrounding collagen fibrils into a more dense and compact arrangement. Collagen gel contraction provides an in vitro model for studying fibroblast‐collagen interactions important in wound healing, fibrosis, scar contraction, and connective tissue morphogenesis. We have assessed the role of fibronectin and its interaction with the α5β1“high affinity” fibronectin‐specific integrin receptor in collagen gel contraction. A variety of agents, which specifically inhibit fibronectin‐α5β1interactions, were tested for their abilities to inhibit fibroblast‐mediated collagen gel contraction. These included anti‐α5β1monoclonal antibodies, the synthetic peptide GRGDSP, the cell adhesive fragment of fibronectin, and an antibody against the cell adhesive region of fibronectin. None of these agents inhibited collagen gel contraction. Therefore, it is concluded that fibronectin‐α5β1interactions are not necessary for collagen gel contraction. However, collagen gel contraction is dependent on a member or members of the β1subfamily of integrin matrix receptors. A polyclonal antiserum and a monoclonal antibody, both directed against the β1subunit of integrin matrix receptors, inhibited the spreading of fibroblasts in the collagen gel and inhibited collagen gel contraction. This study demonstrates that fibroblast‐mediated collagen gel contraction is independent of fibronectin‐α5β1interactions but dependent on an interaction of β1integrin matrix receptors with

ISSN:0003-276X    

DOI:10.1002/ar.1092340202

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

年代:1992

数据来源: WILEY

摘要:

AbstractThe peripheral blood cells of the gilthead seabream (Sparus aurata L.) were studied by light and transmission and scanning electron microscopic methods. Acidophilic erythroblasts and mature erythrocytes, round, oval, and fusiform thrombocytes, neutrophils, acidophils and basophils, lymphocytes, plasma cells, and monocyte‐macrophages were characterized. A comparison of our light and electron microscopic results was carried out. The results were discussed with those for other fish species and the main modifications from the common vertebrate haematological pattern observed being considered.© Willey‐Liss,

ISSN:0003-276X    

DOI:10.1002/ar.1092340203

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

年代:1992

数据来源: WILEY

摘要:

AbstractThe effects of daily prostaglandin E2(PGE2) treatment (on) and PGE2treatment followed by withdrawal (on‐off) on cancellous bone in lumbar vertebral bodies were studied in 7‐month‐old male Sprague‐Dawley rats. The first groups of rats were given daily subcutaneous injections of 0,1,3, and 6 mg PGE2/kg/dfor 60, 120, and 180 days, and the second group of rats were given PGE2for 60 days followed by withdrawal for 60 and 120 days. Histomorphometric analyses were performed on double‐fluorescent labeled undecalcified sections of fourth lumbar vertebral bodies. Systemic PGE2treatment elevated cancellous bone mass of lumbral vertebral bodies 26–60% above control levels within 60 days and continued treatment maintained it for another 120 days, but the excess bone was lost after the treatment was withdrawn. PGE2treatment for 60 days increased trabecular bone area, trabecular width, and bone formation parameters, and shortened remodeling periods in a dose‐response manner. These changes were sustained at the levels achieved by 60‐day treatment in the rats treated for 120 and 180 days. The eroded perimeter increased at day 60 and further at day 120 and then plateaued. In the on‐off treated rats, the cancellous bone area, bone formation, and resorption parameters returned to near agerelated controls by 60 days after withdrawal and were maintained there after 120 days of withdrawal. Therefore we conclude that the continuous treatment is needed in order to maintain the PGE2‐induced bone gain. When these findings were compared to those previously reported for the proximal tibial metaphyses, we found that the proximal tibial spongiosa was much more responsive to PGE2treatment than the fourth lumbar vertebral body

ISSN:0003-276X    

DOI:10.1002/ar.1092340204

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

年代:1992

数据来源: WILEY

摘要:

AbstractData are presented on the number of fibers and the proportion of different fiber types within fascicles of whole vastus lateralis muscles from 5 male children, 5 to 15 years of age, and compared with results from 25 male adults, middle aged and old individuals. The results verify a difference in the proportion of fibers with different properties within a fascicle. The proportion of type 2 (fast twitch) fibers on the border of fascicles is larger than the proportion internally: the children have (P<0.01) greater difference than the adults and the middle aged, whereas the old have (P<0.001) less difference than the other age groups. The mean number of fibers per fascicle increases (P<0.05) from childhood to adult age, and thereafter reduces (P<0.01). The results imply that fascicles continuously rearrange during the normal growth and development and the normal aging process. It is argued that the causes of the difference in fiber type proportions within fascicles are local factors in the muscle, secondary to the overall age related functional demands put on the fiber population.© Willey‐Liss, I

ISSN:0003-276X    

DOI:10.1002/ar.1092340205

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

年代:1992

数据来源: WILEY

摘要:

AbstractThe Na+, K+‐ATPase enzyme through itsp‐nitrophenyl phosphatase activity was localized in the ductuli efferentes of rats. Enzymatic activity was demonstrated along the cytoplasmic side of the plasmalemma of the ductular epithelial cells. The most intense deposition of reaction products was found on the plasmalemma delimiting the lower lateral and basal regions of the cells. The plasma membranes forming the microvilli, apical junctional complexes were devoid of reaction product while the midlateral membranes showed a weak reaction. The enzyme reaction was potassium‐dependent and was abolished by addition of 10 mM ouabain to the incubation media. Enzyme activity decreased significantly from proximal to distal regions of the ductules (8,101.47 ± 274.53, 6,658.95 ± 269.53 and 4,668.10 ± 575.41 pmolesp‐nitrophenol/mm/h, respectively in initial, conus vasculosus and terminal zones). A unified model for water absorption is proposed in the efferent ductules based upon this data and that of others.© Wille

ISSN:0003-276X    

DOI:10.1002/ar.1092340206

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

年代:1992

数据来源: WILEY

摘要:

AbstractRoutine light microscopy and transmission and scanning electron microscopy were used to describe and compare the biliary tree of larvalLampetra lamotteniibefore and during infestation of the bile ducts with the nematode,Truttaedacnitis stelmioides. The most prominent changes to the biliary tree following infection by the parasite are the dilation of the bile ducts, alterations to their epithelial cells, and an increase in periductal fibrous tissue. In recently infected animals, the simple epithelium of dilated bile ducts often contains many mitotic figures. In long‐term infestations, the epithelium is stratified or pseudostratified. Changes to the fine structure of the biliary epithelial cells include increase and/or dilation of the RER and SER, and increases in microfilaments, intermediate filaments, and microtubules. The abundance of dense bodies may reflect enhance reabsorption of biliary constituents, and their accumulation may ultimately result in cytolysis. There are increased mucous granules in the apical cytoplasm of biliary epithelial cells and an abundance of mucinous material within the bile duct lumen, and the basal lamina appears thickened. The changes to the liver ofL. lamotteniifollowing infection are discussed and compared to those reported in small mammals following bileduct ligation, in patients with extrahepatic biliary obstruction, and in parasitic infection of the biliary tree.© Willey‐Liss,

ISSN:0003-276X    

DOI:10.1002/ar.1092340207

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

年代:1992

数据来源: WILEY

摘要:

AbstractRat intestinal 15 kDa protein (I‐15P) is a member of the family of cytoplasmic fatty acid‐binding proteins. Using a specific antiserum against I‐15P, we studied the tissue distribution and subcellular localization of this protein in the entire rat body. By immunoblot analysis of cytosolic proteins, I‐15P was detected not only in the distal portion of small intestine but also in the ovary and adrenal gland. Immunohistochemically, I‐15P was localized to the absorptive epithelial cells as well as a subpopulation of enterochromaffin cells in the intestine, the lutein cells in the ovary, and subpopulations of cortical cells in the adrenal gland. Furthermore, I‐15P‐like immunoreactivity was also demonstrated in the surface mucous cells of stomach and the granular convoluted tubule cells of submandibular gland. Immuno‐electron microscopy showed that the immunoreactivity was confined to the cytoplasmic matrix region, except in the enterochromaffin cells and granular convoluted tubule cells, where it was localized in the secretory granules. The present findings suggest that I‐15P plays a role in the cellular metabolism of steroids.

ISSN:0003-276X    

DOI:10.1002/ar.1092340208

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

年代:1992

数据来源: WILEY

摘要:

AbstractWe previously reported that the pulmonary intravascular macrophages (PIMs) of sheep, goat, and calf lung contained a heparin and a lipolytic lipase sensitive surface coat by using tannic acid as a component of paraformaldehyde‐glutaraldehyde‐based fixative. The implication of this sensitivity was that the surface coat was predominantly comprised of lipoprotein‐like substance. In this study we report that monastral blue (MB) used as a vascular tracer interacted with the coat globules and lost its original particulate appearance. Its precise localization in the PIMs was in combination with altered macromolecules of the surface coat in the form of lipid droplets, which conformed to the conventional view of neutral lipids. In contrast, pigment particles examined in their native state resembled metalic particles as electron‐dense eliptical rods. The lipid droplets were subsequently internalized through endocytic route and found their access into the lysosomal compartments of PIMs at the electron microscopic level. Lamellar bodies (LLBs) arose from the lysosomal matrix after the entry of lipid droplets in the secondary lysosomes. Acid phosphatase activity was located in secondary lysosomes as well as in endosomes. These observations suggest that coat granules of the PIMs acted as a carrier of exogenous MB particles to deliver the complex to the lysosomal compartment where partial digestion lead to the formation of lamellar bodies. The implications of MB (cationic dye) as a vascular tracer for studying phagocytic index of PIMs in the light of their coat and the rapid development of LLBs are discussed. It is proposed that MB by initially combining with the surface coat provokes mobilization of intracellular lipid pools. In this way metabolism of vasoactive lipid in the PIMs is stimulated to influence the dynamics of pulmonary circulation in the calves.© Willey

ISSN:0003-276X    

DOI:10.1002/ar.1092340209

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

年代:1992

数据来源: WILEY

摘要:

AbstractThe bronchial and vascular patterns of the chicken lung, from specimens age 8–10 days, have been studied by serial, paraffin sections of the whole organ. According to the histological structure, the bronchial system consists of three airway types: primary bronchus or mesobronchus, secondary bronchi, and tertiary bronchi or parabronchi. The mesobronchus gives rise to three sets of secondary bronchi: four dorsomedial, four dorsal, and three lateral ones. The total number of secondary bronchi is 11, which is less than the number reported in adult birds by other authors until now. Nevertheless, the number and distribution of the major vessels, arteries and veins are in basic agreement with previous descriptions.© Willey‐Liss,

ISSN:0003-276X    

DOI:10.1002/ar.1092340210

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

年代:1992

数据来源: WILEY