摘要:

Morphology and distribution of epithelial foot processes (FP) were studied in hamster neonatal lung bronchioles. To correlate them with growth, bronchiolar mitotic index was determined, rat small intestine used as a reference tissue and the distribution of foot processes compared to the distribution of immunoreactivity against proliferating cell nuclear antigen (PCNA). In bronchioles, where growth occurs through dispersed mitoses, FP also occur dispersed throughout the whole perimeter of the epithelium; whereas in small intestine, where growth is localised in a specific region (crypts), FP are likewise confined to a distinct, but different, zone (villi). Staining the bronchioles for PCNA labels dispersed grouplets of nuclei; most of which being only weakly stained. In the intestines, strong immunostaining mainly occurs in the crypts, while the villi mainly display a weak nuclear stain. Additionally, in both types of tissue the distribution of FP and weak PCNA staining are parallel. Thus, an apparent association between FP, lack of proliferation and nucleoplasmic PCNA staining arises; the basis of which being presently unclear. However, a possible interrelating factor might be a growth inhibitory influence of epitheliostromal interactions on the epithelial cells.

ISSN:1422-6405    

DOI:10.1159/000147717

出版商:S. Karger AG    

年代:1995

数据来源: Karger

摘要:

In studying epithelio-stromal interactions in the neonatal hamster lung, basal centrioles, basal cilia and open-ring centrioles attracted our attention. The same structures are also found in bronchiolar epithelium of a 3-week-old fawn-hooded rat, indicating that they are not specific phenomena of hamster lung. Although cells with basal centrioles are not common, they are more readily observed in a sample of bronchioles at the second postnatal week as compared to the fourth neonatal day. The centrioles may often possess two satellites and function as microtubule organizing centers (MTOC). Open-ring centrioles are mature structures and also serve as MTOC. Apparently, triplets may de novo be added to and/or degraded from an open-ring centriole. The basal cilia and the cilia in the ciliated vacuoles/cysts, have a normal axonemal structure and may have a common origin from the basal centrioles. It is, however, unclear whether or not they are primary-like cilia. In addition, presence of the multiple basal MTOC and some morphologic features point to a high microtubule-associated vesicular transport activity and probably indicate an elevated interaction with the interstitium; thus, the cells have a different polarization then normal ciliated cells.

ISSN:1422-6405    

DOI:10.1159/000147718

出版商:S. Karger AG    

年代:1995

数据来源: Karger

摘要:

Basement membrane formation of fetal mouse intestinal epithelial cells was investigated in organoid cultures. Intestinal cells were dissociated with a commercial collagenase/dispase preparation, and the cells were grown at high density on a membrane filter at the interface between the medium and air. This type of culture allows the histotypical reorganization of cells. After 2 days in culture, epithelial cells began to accumulate on the surface, in particular at the periphery of the culture. These cells were usually cuboid, and small vesicles were formed in the center of the culture. Laminin-positive material was observed at peripheral sites. However, no basement membrane could be identified beneath the epithelial cells at the electron-microscopic level. After 3 days, epithelial cells that had gathered at the periphery became columnar in shape. Laminin-positive material extended across the surface of the culture. However, the vesicles formed in the center of the culture were not associated with laminin-positive material. Basement membrane was observed by electron microscopy at some sites beneath groups of epithelial cells, but did not extend continuously beneath these cells. Some epithelial cells made contact with the underlying mesenchymal cells through the discontinuous basement membrane via intercellular contacts. After 5-6 days, the surface of the culture was almost completely covered with epithelial cells and, at some sites, villus-like structures were visible. Laminin-positive material was clearly detectable under epithelial cells, as well as around epithelial vesicles located in the center of the culture. By electron microscopy, basement membrane was clearly visible between the epithelial and mesenchymal cells. After 9 days, villus-like structures were rarely observed. After 3 weeks, the cell mass had become smaller and villi had disappeared. Basement membrane was extensively folded and no basement membrane was visible at some sites. Formation of basement membrane by epithelial cells in monolayer culture occurs in an incomplete and irregular manner. It occurs rapidly in organoid cultures that include mesenchyme and epithelium. The organoid culture used here should be a useful tool for studies of the formation and degeneration of the basement membrane as well as interactions between the epithelium and mesenchyme.

ISSN:1422-6405    

DOI:10.1159/000147719

出版商:S. Karger AG    

年代:1995

数据来源: Karger

摘要:

The fine structure of the epidermal basement membrane at the electron-microscopic level has already been defined. To obtain more details, two techniques, dithiothreitol separation and ultrathin frozen sectioning, were applied either alone or in combination. Negatively stained ultrathin sections showed a much thicker lamina densa than ordinary plastic-embedded sections. In the lamina lucida, bridging filaments and subbasal dense plates were observed in negative images. After the treatment with dithiothreitol, the lamina densa could be peeled off mechanically from the underlying dermis, and the anchoring fibrils were pulled off the dermis, preserving the connection with the lamina densa. With this specimen, bundles of anchoring fibrils were observed clearly and their lengths could be measured. Negatively stained ultrathin sections of dithiothreitol-separated specimens showed the fine structure of the lamina lucida. Bridging filaments in the lamina lucida were resolved by negative staining.

ISSN:1422-6405    

DOI:10.1159/000147720

出版商:S. Karger AG    

年代:1995

数据来源: Karger

摘要:

Accumulation and cell death of neutrophils were studied by light and electron microscopy in neonatal mouse bone marrow. At the beginning of bone marrow hematopoiesis, the marrow cavity contained a large number of polymorphonuclear leukocytes. Polymorphs comprised approximately 75% of the total nucleated cells in the hematopoietic compartment of the newborn marrow, the majority being neutrophils. Mature neutrophils were sometimes crossing the endothelium of the marrow blood sinus. Neutrophils in neonatal marrow show features typical of apoptosis, e.g. formation of nuclear pockets and blebs, margination of compact nuclear chromatin to form sharply circumscribed masses, condensation of cytoplasm, and convolution of cell outlines. Dying neutrophils were devoured and digested by phagocytes. The occurrence of large-scale neutrophil death and removal of neutrophils by phagocytes in neonatal bone marrow are discussed in relation to programmed cell death in development of the fetal hematopoietic system.

ISSN:1422-6405    

DOI:10.1159/000147721

出版商:S. Karger AG    

年代:1995

数据来源: Karger

摘要:

In order to obtain a description of the innervation of the vaginal wall we employed an antiserum against the general neuronal marker, protein gene product 9.5, on normal human vaginal mucosa. Specimens were taken from the anterior and posterior fornices, from the anterior vaginal wall at the bladder neck level and from the introitus vaginae region, and then processed for indirect immunohistochemistry. All regions studied revealed a profound innervation, although regional differences were noted. The more distal areas of the vaginal wall had more nerve fibers compared to the more proximal parts. Also, biopsies from the anterior wall generally were more densely innervated than the posterior wall. Some large nerve coils were observed in lamina propria of the anterior wall as well as gatherings of thick-walled medium-sized blood vessels. Free intraepithelial nerve endings were only detected in the introitus vaginae region. These fibers were very thin, always varicose and could be observed just a few cell layers from the surface. In this part of the vagina, protein gene product 9.5 anti¬bodies also stained cells within the basal parts of the epithelium. These cells were also neurone-specific enolase positive and resembled, from a morphological point of view, Merkel cells

ISSN:1422-6405    

DOI:10.1159/000147722

出版商:S. Karger AG    

年代:1995

数据来源: Karger

摘要:

Despite numerous investigations on the enteric nervous system, the knowledge about the mucosal innervation of the human rectum and colon is very shallow and mainly based on ultrastructural studies. We performed an enzyme (NADH-Ach) and immunohistochemical (NF, synaptophysin, anti-Leu-19) study on cryostat sections of the human rectal mucosa in order to study the possible additional characteristics of the mucosal innervation in depth. Enzyme histochemistry reveals positively staining fibers in the muscularis mucosae. Staining with antibodies against neurofilaments and synaptophysin reveals positively staining fibers in the lamina propria and muscularis mucosae. The latter staining is comparable with the findings obtained with anti-Leu-19. The monoclonal antibody anti-Leu-19 is characterized by a nerve-like staining in the mucosa revealed by nerve-like fibers from the plexus submucosus internus (Meissner) penetrating the muscularis mucosae, and creating a real plexus of fine twisted fibers in the lamina propria, around the crypts and underneath the epithelium. The distribution of the mucosal nerve-like pattern in the areas with mucosa-associated lymphoid follicles differs from the pattern observed in the lamina propria in between. Since the monoclonal antibody anti-Leu-19 and the monoclonal antibody NKHla show a great similarity, we were interested also in the possible relation between the nerve like mucosal staining pattern and the lymphocytic population. Comparing the distribution pattern of anti-Leu-19 with other lymphocytic markers, there was an apparent similarity with the distribution of the T-helper subgroup. Our data indicate that the monoclonal antibody anti-Leu-19 shows a nerve-like staining pattern in the mucosa.

ISSN:1422-6405    

DOI:10.1159/000147723

出版商:S. Karger AG    

年代:1995

数据来源: Karger

摘要:

Vascular permeability in various rat sympathetic ganglia, including superior cervical ganglia, thoracic ganglia and the celiac-mesenteric ganglia (CMG) complex, was investigated by using lanthanum and horseradish peroxidase (HRP) as tracers with special attention to the neuronal and small granule-containing (SGC) cell area. After lanthanum perfusion, lanthanum tracer was present within the lumen of blood vessels. No lanthanum depositions were found in the extra-vascular space surrounding neurons in the superior cervical and thoracic ganglia. By contrast, an accumulation of lanthanum was observed in both luminal, abluminal and subendothelial surface of blood vessels in neuronal and SGC cell areas of the CMG complex and surrounding SGC cells in superior cervical ganglia. Injecting HRP revealed that all blood vessels of various sympathetic ganglia, either in neuronal or in SGC cell areas, were impermeable to HRP. HRP reaction product was limited to the vascular lumen and macrophages. The escape of HRP was obstructed by the junctional complex at intercellular clefts of endothelia and also by the diaphragms of the fenestrated capillaries associated with SGC cells. We conclude that there are different properties in the blood-ganglion barriers among rat sympathetic ganglia: (1) continuous capillaries in superior cervical ganglia and thoracic ganglia provide an efficient blood-ganglion barrier that prevents the penetration of tracers, and (2) capillaries in the CMG complex and in regions of the superior cervical ganglia that contain SGC cells possess a selective blood-ganglion barrier that discriminates between tracers based on their molecular sizes.

ISSN:1422-6405    

DOI:10.1159/000313647

出版商:S. Karger AG    

年代:1995

数据来源: Karger

摘要:

We have analyzed the morphometric effects on the dorsal vagal complex (DVC) of the rat of alcohol exposure and/or hypoproteic diet intake during 8 weeks. In the area postrema (AP), alcohol treatment (combined with normal isoproteic or hypoproteic diet) caused a significant decrease in karyometric parameters. In the dorsal motor nucleus of the vagus (DMV) and nucleus tractus solitarii (NTS), the alcohol isoproteic intake (Al) produced an increase in neuron size (expressed by an increase in the neuronal nuclear area and the cell/neuropil coefficient). The hypoproteic diets produced a reduction in the global volume of each structure of the DVC which was accompanied by a decrease in global brain volume. These results indicate that after 8 weeks of treatment, alcohol is the main cause of the morphometric alteration found in the DVC, while variations in the amount of protein intake appear to produce global effects on the whole brain.

ISSN:1422-6405    

DOI:10.1159/000313648

出版商:S. Karger AG    

年代:1995

数据来源: Karger

摘要:

Physiologically, the contractile characteristics and electromyography (EMG) of cat inferior oblique (IO) muscle fibers supplied by the medial and lateral 10 muscle nerve branches were studied by direct nerve stimulation. Anatomically, the brain stem locations and sizes of 10 motoneuron soma were evaluated after retrograde labeling by horseradish peroxidase (HRP) through whole 10 muscle nerves and/or through each medial or lateral 10 muscle nerve branch. Stimulation of the lateral nerve branch elicited significantly (p < 0.005) slower twitch contraction times (8.0 ± 1.5 ms) and lower fusion frequencies (217 ± 46 Hz) than when the medial branch of the 10 nerve was stimulated (average twitch contraction time = 6.8+1.1 ms; average fusion frequency = 260 ± 34 Hz). The EMG wave shape responses in the global and orbital layers could be differentiated when the individual nerve branches were stimulated, but the response differences were not consistent among animals. The average diameter of 10 motoneuron soma with axons in the lateral branch of the nerve were significantly smaller (p < 0.001) than the average diameter of those IO motoneuron soma associated with the medial branch of the nerve (27.9 ± 7.2 vs. 32.9 ± 7.2 μm). Regardless of which nerve branch was labeled, the full range of motoneuron soma sizes was found, and these were distributed throughout the IO subdivision of the oculomotor nucleus. These findings showed that muscle contraction time and motoneuron soma diameter were correlated with the IO nerve branch subjected to stimulation or exposed to HRP. But no topographic organization of motoneurons was found within the IO division of the oculomotor nucleus.

ISSN:1422-6405    

DOI:10.1159/000313649

出版商:S. Karger AG    

年代:1995

数据来源: Karger