摘要:

AbstractBackground: The connective tissue body of the dorsal finger is partitioned by multiple horizontal lamellae derived from expansions of intercellular spaces. These connective fibres are involved in providing gliding spaces for the extensor apparatus, and they formed spreading rooms of infection processes.Methods: In order to describe the topographical histological and histochemical behavior of cellular and intercellular elements of the border lamellae of the dorsal aponeurosis of the fingers, a modified method of Epoxid resin embedding technique without pre‐infiltration is used.Results: The bordering elements of the connective tissue lamellae described in this investigation are especially well defined in the region of the dorsal aponeurosis. The morphological examinations show that both the expansions of the intercellular space as well as defined fibrocytic cellular elements function in a manner equivalent to a synovial membrane of tendon sheaths.Conclusions: Saving or reconstructing these structures appears to be of importance in preventing for adhesive disorders of finger motion following surgical intervention in this region. © 1995 Wiley‐Liss,

ISSN:0003-276X    

DOI:10.1002/ar.1092430102

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

年代:1995

数据来源: WILEY

摘要:

AbstractBackground: The distribution and colocalization of nitric oxide synthase and NADPH‐diaphorase have been investigated quite extensively in the mammalian gut; however, no such study has been under‐taken in the avian gut. In the present report, we have therefore studied the distribution and coexpression of nitric oxide synthase (NOS), NADPH‐diaphorase, and vasoactive intestinal polypeptide (VIP) in enteric neurons of the newly hatched chicken gut.Methods: Immunohistochemical methods were used to detect NOS immunoreactivity (NOS‐IR) and VIP immunoreactivity (VIP‐IR). NADPH‐diaphorase activity was detected using a histochemical technique.Results: Neurons expressing NADPH‐diaphorase activity, NOS‐IR, and VIP‐IR were detected in both the myenteric and submucous plexus of all regions of the gastrointestinal tract examined. All NADPH‐diaphorase positive neurons were also NOS‐IR and all NOS‐IR neurons were NADPH‐diaphorase positive, in both plexuses, indicating that NADPH‐diaphorase can be used as a marker for NOS containing neurons in the chicken gut. The majority of VIP‐IR neurons also expressed NADPH‐diaphorase activity. Only few neurons that expressed NADPH‐diaphorase activity did not express VIP‐IR. The proportion of VIP immunopositive neurons that were NADPH‐diaphorase negative increased anally and these neurons were more prominent in the submucous than the myenteric plexus ganglia. NADPH‐diaphorase positive, NOS‐IR, and VIP‐IR nerve fibres were detected in the circular muscle, but very few, if any, were present in the longitudinal muscle. VIP‐IR, but not NOS‐IR or NADPH‐diaphorase activity, was detected in mucosal fibres, in contrast to the situation in the mammalian gut.Conclusions: These results indicate that in birds, as in mammals, nitric oxide may play a role in the neural control of the gut musculature, but that it is unlikely to be involved in the nervous co

ISSN:0003-276X    

DOI:10.1002/ar.1092430103

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

年代:1995

数据来源: WILEY

摘要:

AbstractOne of the major cell components of the rabbit follicle‐associated epithelium is represented by the M cells. M cells are able to harbour variable amounts of immunocompetent cells inside peculiar invaginations of their basolateral cytoplasmic membrane, currently referred to as “pockets.” This study provides a description of the exact spatial relationships between the M cells and the cells harboured in these so‐called “pockets.”Pieces of Peyer's patches, taken from the small intestine of an adult male rabbit, were treated as usual for conventional electron microscopy. Consecutive semithin and ultrathin sections were made through the entire thickness of the follicle‐associated epithelium along planes parallel to the mucosal surface. Micrographs, taken from the ultrathin sections, were transposed into a software MacDraw Pro to obtain a computerized three‐dimensional reconstruction.Three‐dimensional reconstruction of the M cells showed that the “pockets” were not formed by mere invaginations of the cytoplasmic membrane, but that they resulted from the branching of the supranuclear portion of the M cell cytoplasm around the M cell‐infiltrating lymphocytes. These intrusive cells could be found inside the “pockets” or lined up with one another, in vertical columns, bordering on the basal aspect of the M cells. The particular arrangement of the M cell apical cytoplasm created a labyrinth within the follicle‐associated epithelium, which could be assumed as a real intraepithelial compartment expandable virtually throughout all the epithelium.The functional meaning of the intraepithelial compartment delimited by the M cells and its possible role is discussed. In particular, the definition of a new intraepithelial compartment of the follicle‐associated epithelium, in order to differentiate it from the more generic intraepithelial compartment of the intestinal epithelium, is p

ISSN:0003-276X    

DOI:10.1002/ar.1092430104

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

年代:1995

数据来源: WILEY

摘要:

AbstractBackground: Removal of the uterine luminal epithelium and its basement membrane is necessary for successful implantation of invasive blastocysts. Few reports, however, have specifically addressed the penetration and loss of the uterine luminal epithelial basement membrane (UEBM). We investigated the loss of UEBM by examining the distribution of laminin and type IV collagen.Methods: Blastocyst implantation sites were collected from mice on days 5,6, and 7 of pregnancy. Paraffin sections were prepared from these tissues and processed with standard immunoperoxidase techniques to reveal the distribution of laminin and type IV collagen.Results: On day 5 of pregnancy blastocysts were adherent to the uterine epithelium. The epithelium and UEBM were complete and uninterrupted. On day 6 the juxtaembryonic uterine epithelium was lost and focal discontinuities were seen along the UEBM. By 1200 hr the UEBM had receded to the region near the ectoplacental cone, but staining was reduced for both antigens over the entire region surrounded by decidual cells. This decreased staining of the UEBM occurred in areas not yet occupied by trophoblast cells. On day 7 the UEBM was lost over the entire embryonic half of the uterine lining, corresponding to the distribution of decidual cells.Conclusions: Progressive loss of the UEBM occurred in a consistent spatiotemporal pattern following the onset of blastocyst implantation. Diminished immunoreactivity of laminin and type IV collagen in the UEBM was closely correlated with the area occupied by decidualized endometrial stroma and occurred in areas not yet in contact with trophoblast cells. We conclude that decidual cells are instrumental in the removal of UEBM during early pregnancy. © 1995 Wiley‐Liss, I

ISSN:0003-276X    

DOI:10.1002/ar.1092430105

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

年代:1995

数据来源: WILEY

摘要:

AbstractBackground: A quantitative integrated study of healthy ovarian follicles of different sizes and their mitotic activity and of clearly defined atretic stages of involuting large growing follicles at different stages of the guinea pig ovarian cycle is not available in the literature. We considered that such a study would reveal new aspects of ovarian tissue dynamics and provide new information in an organ with a continuous phenotypic transformation of its cellular components.Methods: Ovaries from guinea pigs were removed on days 1 (opening of the vagina), 3, 6, 9, 13, and 16 of the cycle, and the following were measured in serial sections: (1) total number of healthy follicles falling into categories based on the volume occupied by granulosa cells, (2) total number of atretic follicles falling into clearly defined morphological stages of the degenerative and involutionary process affecting medium to large follicles, and (3) proportion of metaphase‐arrested granulosa cells, after colcemid injection, in healthy follicles of different size categories.Results: Dynamic patterns of follicular growth and degeneration were revealed that permitted the following main conclusions and observations: (1) small to middle‐size follicles can reach the maximal category mass of granulosa mass within 6–7 days, and the number of granulosa cells can increase 6–7‐fold during this interval, (2) the cohort that gives rise to 2–6 preovulatory follicles and to the large follicles that will undergo atresia during each cycle varied from 68 to 108 follicles, (3) cell death starts in the granulosa cell layers of large follicles even when neighbouring cells maintain a high mitotic activity and it spreads rapidly; dead granulosa cells are cleare by nucleolysis and cytolysis in the absence of blood leucocytes or neovascularization, (4) foci of atresia are observed also in a few preovulatory follicles, (5) antral cavities of follicles with dead granulosa cells in the process of being lysed shrink and are filled within 2–3 days with large fibroblast‐like cells arising from phenotypic transformation of inner layers of theca interna, with no evidence of mitotic activity or angiogenesis; the outer layers of theca interna involute, and by progressive atrophy and a process of cell death, minute nodular structures arise with remnants of the ovum and zona pellucida, and (6) a transient wave of degeneration affects a proportion of small and middle‐size follicles during the metestrous period. This process does not resemble the morphological phenomenology of follicular involution, which affects only large follicles.Conclusions: This study contributes to a fuller understanding of the dynamics and time relationships of follicular growth and loss in the guinea pig ovary and provides new morphogenetic information on the atretic process. It would be valuable for the design of experiments on endocrine and paracrine interactions involved in follicular growth and atresia. © 19

ISSN:0003-276X    

DOI:10.1002/ar.1092430106

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

年代:1995

数据来源: WILEY

摘要:

AbstractBackground: Pulmonary type II pneumocytes have been examined by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and morphometry in numerous mammals. Until now, the fine structure of the human type II pneumocyte has not been studied by means of morphometry.Methods: Eleven human donor lungs, which could not be made available for a suitable recipient, were preserved with Euro Collins solution (ECS) according to clinical organ preservation techniques. The lungs were fixed via the airways. Systematic random samples were analyzed by SEM, TEM, and classical stereological methods.Results: Type II pneumocytes showed normal fine structural characteristics. Morphometry revealed that although inter‐individual variation due to some oedematous swelling was present, the cells were in a normal size range as indicated by an estimated mean volume of 763 ± 64 μm3. The volume densities were: nucleus 21.9 ± 2.2%, mitochondria 5.8 ± 0.9%, lamellar bodies 9.8 ± 3.6%, and remaining cytoplasmic components 62.4 ± 2.9% of the cell volume. Since the inter‐individual variations in the volume densities referred to the cell may, to variable degrees, reflect the variation in the reference space, the volume densities referred to the constant test point system and the respective volume‐to‐surface ratios were used for interindividual comparisons. These parameters indicate that lamellar bodies were independent of cellular swelling, while mitochondria nucleus remaining cytoplasmic components increased in size with increasing cell size.Conclusions: Two to 7.5 hours of cold ischemia following ECS preservation do not deteriorate the fine structure of type II pneumocytes of human donor lungs. For reliable assessment of fine structural variation, morphometric parameters are required that are independent of variations in cell size. © 1995 W

ISSN:0003-276X    

DOI:10.1002/ar.1092430107

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

年代:1995

数据来源: WILEY

摘要:

AbstractBackground: The elastic framework of the distal lung has been studied by light microscopy (LM) and transmission electron microscopy (TEM). The preservation of the elastic fibres, for the three‐dimensional observation in their relative positions, is difficult because they lack support when the normal methods of tissue processing are used. The goal of the present study was to understand the three‐dimensional ultrastructure and organization of the elastic fibres of the lung preserved in their relative positions.Methods: A combination of intravascular resin injection and formic acid digestion was used. The resin cast of the microvasculature acted as a scaffold to preserve the in vivo arrangement of the elastic fibres that are, otherwise, easily collapsible. Scanning electron microscopy (SEM) samples were further processed for TEM in order to confirm that the fibres were indeed components of the elastic system.Results: SEM demonstrated a fine framework of elastic fibres, representing remnants of the alveolar walls, with the casted capillaries interwoven with the network of elastin. Each individual elastic fibre is composed of a small bundle of discrete fibrils. Some of these fibrils emerge from the fibre and join other fibres, producing an anastomosing appearance. Several elastic fibres link the walls of the intrapulmonary conducting airways, the vessels walls and the alveolar network, thus establishing an interrelated and interlaced framework.Conclusions: The method we have applied to visualize the elastic fibres of the lung is a unique approach to define the spatial organization of the pulmonary elastic fibres. We have demonstrated here the close relationship between the elastic fibres and the capillaries of the septal alveoli. The arrangement of the interwoven network of elastin and its relationship with the capillaries offers the structural setting for the distending capacity of the alveolar wall. © 1995 Wiley‐Lis

ISSN:0003-276X    

DOI:10.1002/ar.1092430108

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

年代:1995

数据来源: WILEY

摘要:

AbstractBackground. Marsupials are born at an early stage of development after a short period of gestation. In this study the nature and timing of closure of the central cardiovascular shunts was investigated.Methods. Light and scanning electron microscopy were used to determine changes in central cardiovascular shunts in eight marsupial species with gestation periods of between 12.5 and 36.5 days and birth weights ranging from 12.5 mg to 740 mg. Laboratory mice with a birth weight of about 1,000 mg and a gestation period of 21 days were included for comparison.Results. Marsupials have a ductus arteriosus and an interatrial communication. The former closes rapidly after birth in the marsupial; however the interatrial communication is in the form of a fenestrated septum, which closes as result of tissue proliferation over a period of days after birth. An additional central shunt, an interventricular foramen, was found to persist in three species for a short time after birth. In one species, the eastern native cat,Dasyurus viverrinus, which has a gestation period of about 19 days and low birth weight of about 12.5 mg, in addition to the two common shunts there was a large interventricular communication and septation of the outflow tract was incomplete.Conclusion. In adapting from intra‐uterine life, it seems that marsupials have adopted different, but equally effective strategies, with regard to the circulatory system. © 1995 Wiley‐Liss,

ISSN:0003-276X    

DOI:10.1002/ar.1092430109

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

年代:1995

数据来源: WILEY

摘要:

AbstractBackground: Classic theories descibe that the common pulmonary vein develops as an outgrowth from either the sinus venosus or atrial segment. Recent studies show that the pulmonary veins are connected to the sinu‐atrial region before its differentiation into a sinus venosus and atrial segment.Methods: The development of the sinu‐atrial region with regard to the developing common pulmonary vein and the growth of the atrial septum was investigated in avian embryos, using both scanning electron microscopy and immunohistochemistry. Embryos ranging between stage HH12 and HH28 were incubated with QH‐1 that recognizes quail endothelial cells and precursors, HNK‐1, that appears in this study to detect the myocardium of the sinus venosus, or with HHF‐35, being specific for muscle actins. Also vascular casts of the heart were produced by injecting prepolymerized Mercox into the vascular system.Results: In preseptation stages the common pulmonary vein drains into the left part of the sinus venosus, that is clearly demarcated by the sinuatrial fold and HNK‐1 expression. During atrial septation the left part of the sinus venosus, in contrast to the right part, loses its HNK‐1 antigen from stage HH23 onwards, while at the same time the sinu‐atrial fold in the left atrial dorsal wall flattens and disappears. From stage HH25 onwards HNK‐1 expression is restricted to the right part of the sinus venosus, which contributes to the right atrium. The myocardial atrial septum never expresses the HNK‐1 antigen, suggesting that the septum is of atrial origin.Discussion: It appeared that the sinus venosus does not only contribute to the sinus venarum of the right atrium, but also to the left atrium. ©

ISSN:0003-276X    

DOI:10.1002/ar.1092430110

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

年代:1995

数据来源: WILEY

摘要:

AbstractBackground: Although the growth of the developing heart in relation to an increase of ventricular systolic pressure and the growth of the entire embryo during development has been described, no data are available on the growth of the individual segments and intersegmental junctions. Because these different portions are known to function differently, the need for data on their individual development is obvious.Methods: We have measured the volumes of these different compartments by Cavalieri's point counting method in rat embryos from 11 to 17 days.Results: It is shown that sinus venosus and sinu‐atrial junction as well as the main compartments atrium, inlet, and proximal outlet segment grow roughly proportional to the total myocardial volume. Atrio‐ventricular canal and distal outlet segment show a restricted growth and their proportional volumes decrease in time. The inlet segment is the most important part of the ventricular mass at 11 days of gestation, when it is still larger than the proximal outlet segment and, thus, takes the greater part in systolic action of the ventricular mass. The growth of the primary fold increases from day 13 onwards and can be considered as part of the wall of the inlet segment which gives rise to the main part of the ventricular septum.Conclusions: The timing of the septal volume increase fits with qualitative descriptions of ventricular septation. The atrio‐ventricular canal and distal outlet segment have an important constrictive function in early stages, when valves are not yet present. Slow conduction and contraction patterns have been reported to be a characteristic feature of these portions of the embryonic heart. With development of valves these segments are loosing their mechanical function and, thus, their proportional volume declines. © 1995 Wiley‐L

ISSN:0003-276X    

DOI:10.1002/ar.1092430111

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

年代:1995

数据来源: WILEY