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Biomedical subjects

S Wakui

Publications and source records attributed to S Wakui.

50 records · Page 3Linked to original sources
PubMed1989

Subepithelial elastic fibers in the bovine gastric mucosa.

The arrangement of subepithelial elastic fibers in the bovine gastric mucosa was studied by light and electron microscopy, with special reference to the elastic architecture of the cornified papillae. A common feature of their arrangement was that the fibers, derived from the elastic plexus in the deep layer of the lamina propria, extend perpendicularly toward the epithelium giving off the slender branches that end at the epithelial basement membrane. The connecting branches were observed electron microscopically in the form of oxytalan or slender elaunin fibers. The high frequency of fibers was found in the mucosa of the upper part of the ruminal atrium, the ruminal pillars, the reticular cristae and two kinds of cornified unguiculiform and omasal papillae. Each papilla consisted of the core of three-dimensional elastic network and numerous connecting-twigs arising from the superficial points of the network. The mucosae of the ruminal sacs, the floor of the reticular cells and the abomasum except the pyloric part were relatively poor in elastic fibers. These results suggest that the variation in fiber-arrangement may be relevant to the condition of mechanical stress inflicting on the gastric innersurface.

Animals↗
PubMed1989

The ultrastructure of bovine ileal follicle-associated epithelial (FAE) cells during the perinatal period.

The ileal follicle-associated epithelial (FAE) cells in bovine fetuses and neonates were examined by light and electron microscopy. In 7-9 months old fetuses (68, 82 and 86 cm CRL) the dome epithelium was usually a little thinner than elsewhere and contained more intra-epithelial leucocytes. FAE cells were already distinguishable by their being more cuboidal and eosinophilic than the other epithelial cells. The cytoplasm of the FAE cells bulged noticeably into the lumen and contained numerous mitochondria and vacuoles. At 18 hours and 21 hours after birth, the dome epithelium was more columnar and eosinophilic than previously and contained more intra-epithelial leucocytes. The FAE cells showed characteristic bulging of large cytoplasmic processes into the lumen, as seen in the previous stage. In the cytoplasm, moderate numbers of mitochondria, numerous vesicles and microtubules could be seen. Frequently degenerated FAE cells could also be found among normal FAE cells in the epithelium. After this stage the cytoplasmic processes almost disappeared but distribution of the other organelles was similar to that seen at the previous stage except that multivesicular bodies were frequently seen in the apical cytoplasm. These histological results suggest that bovine ileal FAE cells are histologically and functionally mature by birth and that at birth they seem to be able to react against the penetration of pathogenic substances from the extrauterine environment.

Animals↗
PubMed1989

Two- and three-dimensional ultrastructure of endothelium and pericyte interdigitations in capillary of human granulation tissue.

Two- and three-dimensional electron microscopic observation in the immature capillary of the human granulation tissue revealed cytoplasmic interdigitations (CID) between the endothelium and the pericyte. These were composed of a cytoplasmic projection and indentation, and there was a gap space without basement membrane-like components between the two cell membranes. Plasmalemmal vesicles were frequently found locating beneath and/or attached to the cell membranes at the indentated side of the interdigitation. Two kinds of cytoplasmic interdigitation, each having a characteristic configuration, were demonstrated. The CID which was composed of a cytoplasmic projection from the endothelium to the pericyte had a dull-shaped cytoplasmic projection, while the CID which was composed of a cytoplasmic projection from the pericyte to the endothelium had a slender and long finger-like configuration.

Capillaries↗
PubMed1989

[Distribution of the muscle coat at the pars pylorica in swine stomach].

Distribution of the muscle layers around the pars pylorica of the swine stomach was examined. In the antrum pyloricum of the pars pylorica, a distinct stratified structure of the tunica muscularis was found and the muscle bundles of the stratum longitudinale showed rectangular crossing over those of the stratum orbicularis. In the canalis pyloricus of the pars pylorica, on the contrary, stratified structure was indistinct. It is because the running direction of the muscle bundles changes continuously from longitudinal to orbicular layers. In the tunica muscularis of the canalis pyloricus, the authors successfully identified two wide streams of muscle bundles, which were supposed to play an important role in the mechanism of closing the ostium pyloricum. One of the streams was such muscle bundles that distributed annularly around the distal end of the canalis pyloricus forming a broad thick plate inside the curvature ventriculi major. The plate was thick at the curvatura ventriculi major, then became thin toward the curvature ventriculi minor, and finally disappeared. The second of the streams was such muscle bundles that distributed annularly in an area from distal to central part of the canalis pyloricus and, turning its direction to the distal end of the curvatura ventriculi minor, ran in the canalis pyloricus obliquely. Finally it entered into the torus pyloricus where it ran brush-wise, inclining distally, to the tip of the torus pyloricus, and ended as a stump-like form. It is clear that these two streams of muscle bundles functions to narrow the lumen of the distal portion of the canalis pyloricus at the phase of either contraction or relaxation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Two- and three-dimensional ultrastructural observation of two cell angiogenesis in human granulation tissue.

The growth of endothelial sprouts from capillary walls in human granulation tissue has been examined by two- and three-dimensional electron microscopy using a serial sectioning method. Within the parent capillary wall endothelial sprouts composed of two layers of relatively immature endothelium was demonstrated. Three-dimensional reconstruction revealed that the two layered endothelial projections extended and/or migrated outward in a bicellular configuration, the slit-like lumen of the endothelial sprout connecting with the parent capillary lumen. These ultrastructural appearances have not been reported previously with sequential composition to the morphological progression of the sprout. In the cytoplasm of the endothelial sprout, abundant intermediate filaments were assumed to play a mechanical role, tension resistance, in the development of the endothelial sprout. The active endothelial sprout in granulation tissue was considered to be at least partially responsible for the growth of the capillary network and subsequent development of granulation tissue.

Endothelium, Vascular↗
PubMed1988

Fine structural changes in the developing gastric gland cells in the ferret during the postnatal period.

The development of the gastric gland cells in the ferret was studied with particular reference to maturation during the postnatal period. In the newborn, the glands consist of immature parietal cells with numerous mitochondria, and shallow rudimentary intracellular canaliculus with numerous microvilli, and undifferentiated cells. At one week old, mucous neck cells are present containing scattered mucin granules and the parietal cells contain tubulovesicular components. At two weeks old chief cells can be seen with large secretory granules in their basal cytoplasm. The gastric gland cells subsequently increase considerably in size, and their epithelium undergoes rapid histological maturation towards weaning.

Animals↗
PubMed1987

Development of the bovine ileal mucosa.

The development of the bovine ileal mucosa was studied with particular reference to maturation during the fetal and neonatal period. In this region, by 4-5 months of fetal development, vacuolation of the epithelial cells had occurred on the villi, and the goblet and absorptive cells in the crypts were present. By 6-9 months, the villi were longer and more numerous than in the previous stages. At the same time, the vacuolated cells could be seen predominantly on the upper half of each villus. The absorptive cells and goblet cells were more distinct in the crypt and lower half of each villus. Moreover, the goblet cells showed differences in mucin, while in the submucosa the lymphoid follicles were seen to have enlarged to become a prominent feature of the Peyer's patches at this stage. At birth, in suckled animals, the ileal cells on the lower area of each villus and in the crypt appeared more like mature cells. In contrast, there were numerous inclusion bodies in epithelial cells on the upper half of each villus. They appeared in the apical portion of the cytoplasm as vacuoles with stainable or dense contents. By 1 week, however, epithelial cells no longer contained inclusion bodies, and absorptive and goblet cell populations had begun to emerge from the crypts. These histological results suggest that the bovine ileal mucosa has two distinct turning points during its development in the fetus and the neonate. Initially all the mucosal structures are present in fetuses at 6-7 months of gestation, and then the vacuolated cells covering the ileal villi are replaced by mature, nonpinocytosing epithelium which emerges from the crypts on or before the 7th day after birth (ileal closure).

Animals↗
PubMed1986

Nuclear bodies in human prostate with special reference to appearance rate.

The Nuclear Body Appearance Rate in seventeen human prostatic cases was statistically analyzed according to three lesion areas--the hyperplastic nodule, non-nodule and atrophic--in the secretory epithelium and basal cells. It was meaningfully high in the secretory epithelium of the hyperplastic nodule, but not in the other two lesion areas. There was no meaningful result in basal cells. Though there is a wide variety of reported data on the human prostate, particular care must be taken in analysis at the electron microscopic level, keeping in mind that even in a single specimen this organ has a notable variety of tissue changes. The Nuclear Body Appearance Rate reflects cellular hyperactivity although it does not have a specific known function at present.

Atrophy↗
PubMed1985

Histological development of bovine abomasum.

The histological development of the bovine abomasum during fetal and neonatal periods was studied. The abomasum in a fetus of 2.3 cm in length (estimated to be 1 month old) was a separated compartment situated to be caudo-ventral to the primordium on the median plane. On the later stages, the primitive stomach became distinctly separated into rumen, reticulum, omasum and abomasum. The epithelium of abomasum was pseudostratified histologically, consisting of cells low differentiation. The stomach in a fetus of 13-14 cm in length (estimated to be 3 months old) displayed the morphological feature with nearly same proportion as an adult stomach. In this stage, abomasal epithelium had a shape of simple column and also formed gastric pits. Pyloric gland cells could be recognized earliest of all the gastric exocrine cells in fetuses of 16-18 cm in length (estimated to be 3-4 months old). Mucous neck cells could be found in fetuses 43-45 cm in length (estimated to be 5-6 months old). Pyloric gland cell and mucous neck cell contained neutral and sialo- or sulfo mucosubstances in neonates. Chief cells, could be noticed in fetuses 58-65 cm in length (estimated to be 6-7 months old), and were devoid of demonstrable mucosubstance as well as parietal cells. Main abomasal gland cells began to develop to increase rapidly in number in the latter half period of gestation. All the types of gastric cells became to be present and mature in form at birth.

Abomasum↗
PubMedDate not supplied

Prognostic status of p53 gene mutation in canine mammary carcinoma.

BACKGROUND: The p53 gene mutations have been associated with the development of human breast and canine mammary neoplasms; breast carcinoma patients with alterations of p53 gene are considered to have a poor prognosis. Mammary carcinoma represents the most common malignant tumor in female dogs. However, the prognostic significance of p53 gene mutation in the dog has been unclear. STUDY DESIGN: The alteration in exons 5-8 of p53 gene in 69 canine mammary carcinomas were investigated by PCR-SSCP with direct sequence analysis and statistically analyzed to compare with other clinicopathological parameters including age, neuter, tumor size, stage, histology, p53 expression, recurrence and death from carcinoma. RESULTS: 12 out of 69 (17%) carcinomas showed p53 gene mutations. After a follow-up period of 30 months, multivariate regression analysis revealed that p53 gene mutation was only an independent risk factor for increased risk of the recurrence and death from mammary carcinoma. CONCLUSION: The p53 gene alterations might contribute to the prognostic status in canine mammary carcinomas, in a way comparable to that of human tumors.

Adenocarcinoma↗