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Biomedical subjects

M Matsuda

Publications and source records attributed to M Matsuda.

At least 955 records · Page 53Linked to original sources
PubMed1988

Experimental glomerular tissue injury induced by immunization with cultured endothelial cell plasma membrane.

Damage to glomerular endothelial cells, which are the constituents of the size-dependent and charge-dependent glomerular barrier, may result in proteinuria. Brain endothelial cell plasma membrane possesses an intrinsic potential antigenicity which is capable of injuring the blood-brain barrier and causing widespread demyelination in the brain. To examine the pathogenetic effect on the glomerulus of plasma membrane sensitization, we injected guinea pigs with a single dose of plasma membrane products derived from cultured endothelial cells from the brain and umbilical cord, and observed the resulting effects both clinically and by histological, immunofluorescence and ultrastructural examinations of renal tissues. The animals immunized with plasma membrane products showed clinically mild proteinuria. Proliferative changes in the mesangial matrix with mild mononuclear cell infiltration was observed in the glomeruli of all experimental animals. Immunofluorescence studies showed finely granular, peripheral capillary loop and mesangial staining for IgG and C3. Electron microscopy revealed fine, electron-dense deposits in the subendothelial region. In addition, titers of anti-endothelial cell antibodies and circulating immune complexes were significantly high. It was suggested that antibody-mediated immune mechanisms might play a role in the pathogenesis of this glomerular tissue injury induced by immunization with cultured endothelial cell plasma membrane products.

Animals↗
PubMed1988

Evidence for disulfide bonds in membrane-bound and solubilized opioid receptors.

The effects of pretreatment with dithiothreitol (DTT) on opioid binding activities of membrane-bound and digitonin-solubilized opioid receptors from bovine adrenal medulla were studied. Pretreatment of membranes with DTT or mercaptoethanol inhibited [3H]diprenorphine binding by reducing the number of binding sites. The inhibitory action of DTT was time and dose dependent. The binding of [3H]D-Ala2-D-Leu5-enkephalin was also inhibited by DTT pretreatment. Pretreatment of digitonin-solubilized binding sites with DTT also reduced the number of [3H]diprenorphine binding sites. The action of DTT was diminished by preincubating the DTT solution with H2O2. [3H]Diprenorphine protected the opioid binding sites from the inhibitory action of DTT. The present results provide evidence that disulfide bonds are implicated in opioid binding activity of the opioid receptor system.

Adrenal Medulla↗
PubMed1988

The corneal endothelium following autokeratoplasty. A case report.

An autokeratoplasty was performed on the left eye of a 64-year-old female, with the graft transferred from the contralateral, blind eye. The endothelial morphology and thickness of the central cornea were studied pre-operatively and yearly for 6 years after surgery. The endothelial cell density decreased rapidly during the first 2 years post-operatively (55.5%), after which cell loss occurred at a considerably slower rate (about 2% of the pre-operative cell density per year). During the observation period, the coefficient of variation in cell size stayed relatively constant (approximately 0.3). When the corneal thickness returned to normal 2 months after surgery, the endothelium showed a significant decrease in the percentage of hexagonal cells (15.0%). Between 2 months and 2 years post-operatively, the percentage of hexagonal cells gradually returned to normal. These endothelial changes noted are remarkably similar to those previously seen in homografts, suggesting that cell damage due to immunologic reactions may not be a major factor in long-term endothelial changes after homografting.

Cornea↗
PubMed1988

Surgical repair of varicocele: effective treatment for subfertile men in a controlled study.

We performed a comparative study to evaluate the efficacy of surgical repair of varicoceles in improving fertility. A group of 224 subfertile men with varicoceles was divided into 141 patients who had their varicoceles surgically corrected and 83 who had not. A significant improvement in sperm density and percentage of progressive motile sperm was noted in the corrected group (p less than 0.01, p less than 0.05). Pregnancy rate was also higher in the corrected group (p less than 0.05). From this controlled study we conclude that the repair of a varicocele increases the chance of fertilization.

Adult↗
PubMed1988

Three types of vitronectin in human blood.

Vitronectin is a cell-adhesive glycoprotein in serum and plasma, also termed serum spreading factor and complement S-protein. It consists of a mixture of a polypeptide of molecular weight 75 kilodalton (kDa) and its nicked product of 65 kDa plus 10 kDa. By a quantitative immunoblotting assay, human blood samples could be classified into three distinct vitronectin types; type I (58% of the population) was 75 kDa rich and 65 kDa poor, type II (35% of the population) contained approximately equal amounts of 75 kDa and 65 kDa, and type III (5% of the population) was 75 kDa poor and 65 kDa rich. The vitronectin type did not correlate with age, sex, or ABO blood type.

ABO Blood-Group System↗
PubMed1988

Distribution and progression of coronary arterial and aortic lesions in the conventional Watanabe heritable hyperlipidemic rabbit--quantitative analysis.

The distribution and progression of coronary arterial and aortic lesions were examined in 40 conventional Watanabe heritable hyperlipidemic (WHHL) rabbits. They were classified according to age into stage I (3-5 months old, 14 rabbits), stage II (6-12 months old; 12 rabbits) and stage III (14-28 months old; 14 rabbits). Fifteen normal Japanese rabbits served as controls. The findings obtained from serial and transverse sections of each of the extramural coronary arteries (ECA) and transverse sections of 4 to 5 equal pieces of whole ventricle for intramural coronary arteries (ICA) were quantified by an image analyzer. Atherosclerosis with positive Sudan III stain was seen in aorta, ECA and ICA over 200 mu in diameter. Atherosclerotic lesions were noted in the aortic arch in stage I rabbits and in the whole aorta in stages II and III rabbits. In ECA, stenosis due to atherosclerosis was noted in 14, 33 and 93% of stages I, II and III rabbits, respectively. Stenosis of over 75% in the orifices of the left and right coronary arteries was noted frequently (71%), while mural thrombi, hemorrhage, intimal rupture and recanalization were seen rarely. Striking features were non-atherosclerotic stenosis with negative Sudan III, seen in the ICA less than 200 mu in diameter of almost all the hearts of stages II and III rabbits. Acute and old myocardial infarction appeared in 5 of the 14 hearts of the stage III rabbits and the infarct-related ECA showed severe stenosis of over 90%. In conclusion, to detect coronary atherosclerosis, serial and transverse sections of ECA are needed. In conventional WHHL rabbits, the incidence of stenosis in ECA is very high, compared with that of the previous reports, and myocardial infarction is due to severe stenosis in ECA. Non-atherosclerotic lesions in ICA occur before the appearance of the atherosclerotic lesions in ECA.

Animals↗
PubMed1988

Demonstration of gonadotropin-induced plasma renin activity in human internal spermatic vein.

In order to investigate the secretion of renin from the Leydig cells of human testis, plasma renin activity (PRA) in left internal spermatic vein (ISV) and cubital vein (CV) was measured at the time of surgical repair of varicocele in 19 patients aged from 21 to 39 years. Ten of them were given a single im administration of hCG (10,000 IU/m2) 4 days before the operation, whereas the remaining nine were not treated. Although mean PRA levels in CV in treated and non-treated groups were similar (1.25 +/- 0.45 and 1.14 +/- 0.38 nmol/l per h, respectively), mean PRA level of ISV in the treated group (3.52 +/- 0.76 nmol/l per h) was significantly higher than that in the non-treated group (1.30 +/- 0.32 nmol/l per h) (P less than 0.01); serum testosterone levels in the same ISV were also much higher in the treated than in non-treated group (P less than 0.001). These data show the following results; 1) under basal conditions, no release of renin from Leydig cells into testicular blood flow could be observed; 2) after treatment with hCG, the secretion of renin into the ISV seemed to be demonstrable. The present results suggest for the first time the secretion of hCG-induced renin from the human testis in vivo.

Adult↗
PubMed1988

Induction of renin-angiotensin system in human testis in vivo.

To better understand the local renin-angiotensin system in Leydig cells of the human testis, the plasma renin activity (PRA) and plasma concentration of angiotensin II (PAII) in the left internal spermatic vein (ISV) and cubital vein (CV) were measured at the time of surgical repair of varicocele in 27 patients. Fourteen of the patients were given a single i.m. injection of hCG (10,000 IU/m2) 4 days before the operation, whereas the remaining 13 were not treated. Although the mean PRA or PAII levels in the CV in the treated and nontreated groups were similar, both levels in the ISV in the treated group were significantly higher than in the nontreated group (p less than 0.05). For PAII levels in the treated group, nine of 11 patients with an increased PRA level showed significantly higher levels than the normal peripheral PAII value. The serum testosterone levels in the same ISV were also much higher in the treated group than in the nontreated group (p less than 0.001). These results suggested the possibility that sex steroids might influence the renin-angiotensin system in Leydig cells.

Adult↗
PubMed1988

Optimal temperature for synthesis of DNA, RNA, and protein by human testis in vitro.

To determine the optimal temperature for DNA, RNA, and protein syntheses in the human testis, the levels of incorporation of 3H-thymidine, 14C-uridine, and 14C-leucine into testicular tissue were studied at 28 degrees C, 31 degrees C, 34 degrees C, and 37 degrees C in vitro. The results suggest that the DNA synthesis is at a maximum at 31 degrees C and shows delicate temperature sensitivity, whereas the RNA and protein syntheses are at a maximum at 34 degrees C or 37 degrees C and are temperature-dependent. It is concluded that the temperature sensitivity of DNA synthesis may be one of the primary causes of delicate thermal inhibition of human spermatogenesis.

Cells, Cultured↗
PubMed1988

Transport and metabolism of pyridoxine in the intestine of the mouse.

The absorption of pyridoxine from the intestine of the mouse was studied in whole animals. [3H]Pyridoxine was orally administered and the distribution of isotope between the six recognized forms of vitamin B6 was determined in portal and peripheral blood after the administration. When small doses (1.4 or 14 nmol) were administered, labeled pyridoxine could hardly be found in the portal blood as well as in the peripheral blood, although labeled pyridoxal and pyridoxal phosphate were found both in the portal and peripheral blood. However, when a large amount (46 or 140 nmol) was given, a significant amount of labeled pyridoxine was found with labeled pyridoxal and pyridoxal phosphate both in the portal and peripheral blood. These results suggest that a physiological dose of pyridoxine is transformed to pyridoxal in the intestinal tissues and then is released in the form of pyridoxal into the portal blood.

Animals↗