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Biomedical subjects

Y Kadoya

Publications and source records attributed to Y Kadoya.

At least 55 records · Page 3Linked to original sources
PubMed1994

The expression of osteoclast markers on foreign body giant cells.

The expression of some candidate osteoclast markers, tartrate-resistant acid phosphatase (TRAP), macrophage associated antigens (M phi Ag), and vitronectin receptor (VNR) on foreign body giant cells (FBGCs) was investigated in peri-implant tissues of loosened total joint arthroplasties. Osteoclasts showed distinct staining characteristics. They were strongly TRAP-positive at tartrate concentrations of 50-200 mM and expressed VNR and a restricted range of M phi Ag. In contrast, FBGCs were shown to be significantly heterogeneous. Significant numbers of FBGCs were TRAP-positive at a 100 mM tartrate concentration and some were more intense than osteoclasts. A population of FBGCs did not express M phi Ag such as CD11b, but expressed VNR. It was demonstrated that these candidate osteoclast markers were also positive on FBGCs. These results have highlighted the difficulty in distinguishing these two cell lineages and suggested that there might be some uncertainty in defining osteoclast-like cells in culture studies.

Acid Phosphatase↗
PubMed1994

Role of mesenchymal nidogen for epithelial morphogenesis in vitro.

Recent biochemical studies suggested that the extracellular matrix protein nidogen is a binding molecule linking together basement membrane components. We studied its expression and role during development. By immunofluorescence and northern blotting, nidogen was found early during epithelial cell development of kidney and lung. Yet, in situ hybridization revealed that nidogen was not produced by epithelium but by the adjacent mesenchyme in both organs. Binding of mesenchymal nidogen to epithelial laminin may thus be a key event during epithelial development. This is supported by antibody perturbation experiments. Antibodies against the nidogen binding site on laminin B2 chain perturbed epithelial development in vitro in embryonic kidney and lung. Mesenchymal nidogen could be important for early stages of epithelial morphogenesis.

Animals↗
PubMed1993

Distribution of alpha 6 integrin subunit in developing mouse submandibular gland.

We examined the development of mouse submandibular gland by light and electron microscopy and determined the distribution of the alpha 6 integrin subunit and laminin in this process by immunofluorescence and immunoelectron microscopy. At Days 13.5 and 14 of gestation alpha 6 was localized over the entire cell surface of undifferentiated epithelial cells of the terminal cluster. On Day 15 the expression of alpha 6 could no longer be detected over central cells in the proximal portion of branched terminal cluster, whereas peripheral cells were stained over the entire surface. On Day 17 of gestation to day of birth, alpha 6 expression was restricted to the basolateral surface of the differentiated acinotubular structure. Its expression on acinar cells was uniformly distributed throughout the basolateral membrane, but on duct cells stronger staining towards the basal surface was noted. Similar expression was observed in adult acinar and duct cells. Expression of the alpha 6-subunit at the cell-cell contact in an early stage and its expression at the basolateral surface in an advanced stage indicate that integrin containing alpha 6 plays a significant role in cell-cell and cell-substrate interaction. Stage and cell type-specific change of integrin expression may be significant for submandibular development.

Animals↗
PubMed1993

[Factors for weight loss in patients with senile dementia].

The authors investigated causes for weight loss in inpatients with senile dementia, who could take diets. The 81 patients (80 +/- 8.3 years of mean age +/- S.D., 22 males and 59 females) included 48 cases of senile dementia of Alzheimer type (SDAT) and 25 cases of multi-infarct dementia (MID). Controls consisted of 77 non-demented patients (82 +/- 9.1 years, 29 males and 48 females) who were admitted because of cerebrovascular or cardiopulmonary diseases. Demented patients showed an average of -1.8 +/- 8.5% weight change per year, while that of non-demented patients was +4.4 +/- 6.3%, resulting in a significant difference between them (p < 0.0001). Between demented males and females, there was no significant difference. In male, SDAT cases showed more weight loss than MID cases (-5.0 +/- 5.1% vs +3.3 +/- 4.2%, P = 0.003), although in females there was no significant difference between SDAT and MID. Even when patients with a wandering tendency or complications were excluded, results essentially did not change. In demented patients, weight change did not correlated with age, amount of dietary intake, length of hospital stay or serum albumin level. However, it correlated with body weight (r = 0.26, P = 0.014), ADL index (GBS-A) (r = 0.22, P = 0.04), and with Mini-Mental State Examination score (r = 0.23, P = 0.048). In multiple regression analysis, the most powerful explanatory variable in demented males was the index for cerebral atrophy. These results confirmed previous studies reporting that reduced dietary intake, complications or hyperactivity do not fully explain weight loss in demented patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

Ultrastructure of the basement membrane and its precursor in developing rat submandibular gland as shown by alcian blue staining.

The ultrastructure of the epithelial basement membrane and membrane precursor was studied in rat submandibular rudiment and a model system of the reconstructed basement membrane, by transmission electron microscopy following alcian blue staining. Directly beneath the epithelial plasma membrane, a meshwork layer was found to consist of anastomosing thin fibers arranged as a three-dimensional meshwork (100-400 nm in thickness). Straight strands (5-10 nm in diameter) could sometimes be seen to pass through the meshwork. Adjacent to this layer, a coarse network composed of threads (20-40 nm in diameter) connected the meshwork layer with collagen fibers of the underlying connective tissue. The earliest precursors recognized in the reconstruction-model system were part of the fine-meshwork structure, and showed this structure to be a fundamental component of the basement membrane.

Alcian Blue↗
PubMed1992

[Mild hypothermia in patients with senile dementia].

From the viewpoint of the high frequency of mild hypothermia in patients with senile dementia, we investigated causative factors in comparison with accidental hypothermia. We also investigated the relationship between hypothermia and the type or grade of dementia. A total of 127 demented cases including 30 males and 97 females, whose mean age was 80.6 +/- 8.9 years, were classified into 3 groups according to the axillary temperature measured in August 1989. Group A consisted of 33 cases whose body temperature was below 36 degrees C on more than 25 days. Group C consisted of 24 cases whose body temperature was above 36 degrees C on more than 25 days, and the remaining 70 cases were classified as group B. The frequency of group A classification in demented patients was higher than age-matched non-demented controls (26% vs 13%, p less than 0.05). In demented males, serum total cholesterol, serum albumin, and hemoglobin were significantly higher in group A than in group B or C. Body weight and serum triglyceride were also higher in group A, but not significantly. In demented females, serum albumin and hemoglobin were higher in groups A and B than group C. In addition, cases with diabetes mellitus or cases receiving with major tranquilizers were more frequent in group A, and the index of activities of daily living was higher in group A, in both sexes. Factors such as age, CRP or thyroid hormone (free T3, free T4) showed no significant difference among the 3 groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

Reconstruction of the basement membrane in a cultured submandibular gland.

In a rat submandibular rudiment on day 16, both laminin (LM) and type IV collagen (Col-IV) were found in all cases to colocalize not only in the basement membrane, but also in the rough endoplasmic reticulum of the epithelial cells, indicating that the synthesis of the components of basement membrane is greatly enhanced at this particular stage of extensive branch formation. Using the submandibular gland from a 16-day embryo, the model system was developed to determine the structural organization of the basement membrane. The pre-existing basement membrane was digested with collagenase and dispase, causing its complete disappearance. The subsequent gradual reconstruction of an authentic basement membrane was confirmed by electron microscopy and immunohistochemistry of LM and Col-IV. In the model system, this recovery started at 4 h of culture, and formation was complete by 8 h. During the recovery, thick bundles of actin filaments appeared transitionally in the basal cytoplasm. Electron microscopic analysis indicated two precursor structures, aggregated fuzzy fibers (type 1 extracellular matrix (ECM)) and 10-nm-thick strand piles (type 2 ECM), and an authentic basement membrane structure appeared during the course of membrane reconstruction. LM and Col-IV were always located together in these three structures. These observations clearly indicate that the precursors, containing LM, Col-IV and most likely heparan sulfate proteoglycan, appeared to form immediately following their secretion into the extracellular space, and assembled into the rigid structure of basement membrane within 8 h. The ultrastructural and immunohistochemical process of basement membrane reconstruction appeared to coincide closely with that of the glomerular basement membrane in developing kidney.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Established mouse liver cell lines as a model system for studying epithelio-mesenchymal interactions in morphogenesis.

Four cell lines were established from both fetal and adult livers of mice (ddY strain) by colony isolation methods, and these were characterized by morphological, immunological and biochemical examination. An epithelial cell line from a fetus (eE1-10) was identified to be derived from the biliary tract epithelium. Another epithelial cell line from an adult (aE3) reconstructed bile canaliculi-like structures in aggregates and secreted several serum proteins, indicating that it was derived from the hepatic parenchyma. The other two lines (eF1 and aF1) are fibroblastic in morphology. These were derived from fetal and adult livers, respectively. Both eE1-10 and the fetal fibroblastic cell line (eF1) are hypotetraploid, whereas both aE3 and the adult fibroblastic cell line (aF1) are hypodiploid. All four cell lines showed both contact inhibition and anchorage dependency of growth. Luminal structures with basal laminar, similar to bile ducts, were reconstituted from eE1-10 cells when co-aggregated with aF1 fibroblastic cells. Luminal structures were also formed from eE1-10 cells embedded in collagen gel. These, however, had no basal lamina and there was less development of microvilli than in aggregates mixed with fibroblastic cells. These results indicate that the fibroblastic cells afford favourable conditions for maintenance of the elaborated luminal structure of epithelial cells through production of the basal lamina.

Animals↗
PubMed1990

Effects of thyroid hormone and actinomycin D on phosphate uptake of brush-border membrane vesicles from kidney of rachitic rats.

It is generally accepted that 3,5,3'-triiodothyronine (T3) is responsible for most of the known physiological actions of thyroid hormone. Our new rachitogenic diets, deficient in both vitamin D and iodine and low in phosphorus (1.13% calcium and 0.14% phosphorus), induced typical rachitic changes in rats. To know the possible role of T3 on bone and phosphate (Pi) metabolism and its related biochemical and molecular mechanism, weanling male Wistar rats were fed this diet for 28 days, and then treated with 6 micrograms/100g BW of T3 and/or 60 micrograms/100g BW of actinomycin D intraperitoneally. After 2 hours of treatment, renal brush-border membrane vesicles (BBMV) were prepared according to the calcium precipitation method, and their Na(+)-dependent Pi uptake was analyzed by Lineweaver-Burk plots. Km value was not significantly altered by all these treatments. In contrast, Vmax value as a Pi uptake index was significantly increased in T3-treated rats compared with rachitic control. This increase was evident as less as 2 hr after T3 administration, so it was assumed that T3 stimulated the Pi uptake not by mediation of the de novo protein synthesis. However this increase was suppressed by administration of actinomycin D, and then this result suggests that the antirachitic effect of T3 is mediated by somehow de novo protein synthesis. After all, T3 acting as an antirachitic agent, the most likely possibility is that T3 provides favorable conditions for mineralization of bone by improving Pi transport in various types of cells, even under rachitogenic condition, at least of hypophosphatemic type, and correction of phosphate metabolism may be the most essential prerequisite for cure of this type of rickets.

Animals↗
PubMed1990

IgA myeloma complicated by fractures of the bones and hyperviscosity syndrome--report of an autopsied case.

A case of IgA (kappa type) myeloma complicated by fractures of the bones and hyperviscosity syndrome is presented. A 56-year-old woman who had been followed as an outpatient with diabetes mellitus for about 16 years, developed multiple myeloma. She also showed symptoms and signs of hyperviscosity syndrome; hemorrhagic diathesis, blurred vision and episodes of transient ischemic attacks of the brain, and fractures of the bones by small powers of trauma. At autopsy, almost all bones showed infiltration of multiple myeloma of IgA-kappa type and severe osteoporosis accompanied with proliferation of osteoclasts. The association of IgA myeloma with hyperviscosity syndrome and/or bone destruction was discussed. The "serum hyperviscosity syndrome" has been described clinically as the triad of bleeding, visual signs and symptoms, and neurologic manifestations. And this syndrome has been associated frequently with macroglobulinemia of Waldenström, occasionally with immunoglobulin (Ig) G myeloma, rarely with IgA myeloma, and with other dysproteinemia. Myeloma is also characterized by extensive bone destruction and is accompanied by susceptibility to fracture, although Waldenström's macroglobulinemia, acute leukemia or chronic leukemia are rarely associated with bone resorption. The present report describes a patient with IgA myeloma complicated by hyperviscosity syndrome and multiple bone fractures.

Blood Viscosity↗
PubMed1989

Intracellular accumulation of basement membrane components during morphogenesis of rat submandibular gland.

The distribution of two basement membrane (BM) components, laminin (LN) and type IV collagen (COLL IV), during acino-tubular morphogenesis of rat submandibular gland was examined immunohistochemically to determine the role of BM in the development of acino-tubular structures. On day 14 of gestation, LN could be found only in the BM separating an undifferentiated cell cluster of gland epithelium from surrounding mesenchyme. However, during a short period through days 15 to 17, LN was detected not only in the BM but also in intracellular vesicles of the cells of the terminal cluster. Immunoelectron microscopy showed the intracellular immunoreactive sites to be rough endoplasmic reticulum, indicating that active LN synthesis occurs in the cells of the terminal cluster. Intracellular immunostaining of LN disappeared completely on day 19 with the development of simple epithelium from the cell cluster, even though BM remained reactive. COLL IV also was accumulated in the intracellular vesicles of terminal cluster cells on day 16 of gestation but not on day 19. These results indicate that synthesis of certain BM components is transiently stimulated in gland epithelium before the formation of simple epithelial structure, and that these components are significantly involved in morphogenesis of the submandibular gland.

Animals↗
PubMed1989

Immunohistochemical localization of two types of carbonic anhydrase isozymes in oncocytoma and oncocytic epithelial cells.

An immunohistochemical study was performed on the localization of carbonic anhydrase isozymes I and II (CA I and CA II, respectively) in oncocytoma and oncocytic epithelial cells. Tumors examined were those deserved to be called oncocytomas such as Warthin's tumor, Hürthle cell tumor of the thyroid gland and renal oncocytoma. In addition, the same immunostaining was done on several pathologic lesions, accompanying moderate number of cells similar in tinctorial character to oncocytes, such as some type of adenoma of the thyroid gland, endometrial hyperplasia, endometriosis and so on. Specific antibodies against CA I and CA II prepared from human erythrocytes were converted into Fab' fragment and labeled with horseradish peroxidase. In each tissue sample, the majority of oncocytes or oncocytic epithelial cells showed a tendency to exhibit an immunostaining reaction for CA I and II intenser than that of adjacent original normal epithelium from which they might derive. To the authors' knowledge, no reports have been appeared on biological relevance of an increased activities of carbonic anhydrase in conjunction with a large number of mitochondria appearing in such oncocytic cells. In the present study, it is revealed that the immunoreactivities of CA isozymes increased in oncocytes as the number of mitochondria increased, suggesting that oncocytes have a high level of carbonic anhydrase for catalyzing the hydration of an increased amount of carbon dioxide generated chiefly via oxidative metabolism by mitochondria, the number of which is notably increased compensatorily for their deficient coupling of oxidative phosphorylation or other metabolic anomaly.

Adenoma↗
PubMed1989

Pulmonary embolization-induced thymus hyperplasia in rabbits.

The effects of pulmonary embolization on the thymus glands of rabbits were studied morphologically, morphometrically and immunohistochemically. Pulmonary embolization was induced by an intravenous injection of 0.4 ml of Sephadex bead suspension (particle size; 150 to 300 microns, about 2,000 per ml). Both mean weight and volume of the thymus of rabbits killed at 2 weeks after embolization, were about 1.5 times more than those in control animals treated with physiologic saline. Histological examinations showed enlargement of the cortex and medulla of the thymus, and the embolized Sephadex beads in the branches of pulmonary arteries of the lung. The area ratios of medulla/cortex, in the embolization group and in control, were not significantly different. The cells with immunohistochemically positive staining of anti-nuclear antigen of monoclonal antibody of Ki-67, were found in both portions of the medulla and cortex. These data suggest that pulmonary embolization in the rabbit induces true thymic hyperplasia. An intravenous injection of India ink into the right highest intercostal artery revealed the distribution of bronchial arteries, which send the branches to the right lobe of the thymus. In 2 out of 4 animals killed 2 weeks after pulmonary embolization, the left lobe of the thymus as well as the right were stained with the injected ink. As it is known that pulmonary vascular obstruction caused a marked increase in the bronchial blood flow, these data suggest that the thymus blood supply from the bronchial arteries increases in the conditions of pulmonary embolization, which might contribute to thymus hyperplasia.

Animals↗
PubMed1987

Density dependent growth of corneal endothelial cells cultured in vitro.

Using the cornea of macaque monkey, we demonstrated the relationship between cell density and growth of endothelial cells in vitro. Corneal endothelial cells in a cell sheet grow most actively in regions with cell density of 1000 to 1800 cells/mm2, in explant cultures and cell sheets and in concentrated inocula dissociated cells. Cell morphology was well sustained in these cultures. Cells cultured at a higher cell density retained their potential to proliferate actively, showing clear contrast to cells cultured at a density lower than 200 cells/mm2. When dissociated cells were cultured at a low density and maintained for more than 4 weeks, they gradually lost their growth potential, altered into polymorphonuclear giant cells and eventually dedifferentiated. In addition, cells with no contact with each other did not express growth potential. Density dependent growth was confirmed by measuring the mitotic index against the cell density per square mm from the center to the peripheral regions in cultured explants. It is concluded that the growth pattern of corneal endothelial cells is closely related to cell density, and that growth of these cells might be regulated through intercellular communications.

Animals↗