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Biomedical subjects

G Osawa

Publications and source records attributed to G Osawa.

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

The attitude of Japanese physicians regarding genetic service for autosomal dominant polycystic kidney disease (ADPKD).

A questionnaire carried out among Japanese physicians revealed that a strong demand for genetic counseling among patients and families with autosomal dominant polycystic kidney disease (ADPKD). In contrast, the awareness of physicians regarding genetic counseling for the disease seemed to be low. For example, 66.0% of the respondents to the questionnaire revealed a negative attitude to providing genetic counseling for patients, and 30.7% of the respondents did not know that most types of polycystic kidney disease are inherited disorders. With the advance of scientific research, the demand for genetic counseling among patients is bound to increase. Therefore, the providers of genetic counseling including the physicians are now pressed to improve their services.

Adult↗
PubMed1994

Renal hypouricemia: incomplete combined defect.

A 20-year-old man with hypouricemia with markedly increased renal uric acid clearance is described. He also exhibited idiopathic hypercalciuria and lipoid nephrosis on hospital admission. Urate excretion was minimally suppressed by pyrazinamide and minimally increased after administration of probenecid, whereas it decreased after administration of benzbromarone. These results suggest that not only presecretory reabsorption, but also postsecretory reabsorption of urate was incompletely defective and indicate that the latter is more defective than the former. The relationship between hypouricemia and hypercalciuria or lipoid nephrosis in this case is not clear. However, since the hypouricemia persisted despite the remission of minimal change nephrotic syndrome, it appears that at least his nephrosis was incidental.

Adult↗
PubMed1993

A splicing mutation in the alpha 5(IV) collagen gene of a family with Alport's syndrome.

DNA sequence analysis of the alpha 5(IV) collagen chain gene (COL4A5) was carried out between exon 47 and 51, which encode the noncollagenous (NC) domain, in eight Japanese families with Alport's syndrome. In one family with X-linked inheritance of the disease, a point mutation (G to C) was found at the 3' end of exon 49 in the COL4A5. This mutation converted the codon of a conserved methionine-1601 to the codon for isoleucine, and also altered the normal splicing process. The polymerase chain reaction (PCR) product amplified between exons 47 and 51 of cDNA in the affected male (hemizygote) of this family contained four fragments with various molecular weights, whereas that of a normal control contained one with the expected molecular weight. Sequence analysis of the PCR fragments of the male patient revealed various types of alternative splicing between the exons, reflecting the various sizes of PCR fragments. The PCR amplified product of the cDNA of the affected female (heterozygote), on the other hand, contained a fragment with the same molecular weight as the normal control. Sequence analysis of the PCR fragments of her cDNA revealed normal splicing and no point mutation at the 3' end of exon 49. These findings indicate that this point mutation at the consensus sequence not only converted the codon but also altered the splicing between these exons encoding the NC domain of the COL4A5. Resulting in missense of the alpha 5(IV) chain, changing a large portion of the carboxyl terminal crosslinking NC domain, this mutation can alter the normal structure of the type IV collagen network.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

A kinetic study of the glomerular cells of developing and mature rat kidneys using an anti-bromodeoxyuridine monoclonal antibody.

Newborn and mature Wistar rats received a single intraperitoneal injection of 5 bromo-2'-deoxyuridine (BrdU), a DNA precursor, to assess cellular proliferation by labeling S-phase cells. For immunohistochemical analysis, paraffin sections were prepared two hours after BrdU injection. The various stages of development of the glomeruli were observed within each newborn rat. The most primitive glomeruli were found close to the renal capsule, with progressively more mature glomeruli appearing in the deep renal cortex. BrdU-positive nuclei were frequently detected in the epithelia of nephrogenic vesicles, S-shaped vesicles and ureteral buds. When the capillaries invaded the S-shaped vesicles, the developing glomerular basement membrane was recognizable. In this and more mature stages of the glomeruli, presumptive podocytes no longer showed BrdU-positive nuclei, but they were easily detected in the mesangial and endothelial cells of the glomerular tufts. The mean labeling index of the glomerular tuft cells of mature rats was approximately 0.54%. The majority of labeled cells in the glomerular tufts were endothelial cells. Mesangial cells had a low labeling index. Podocytes revealed no evidence of proliferation. The labeling index of Bowman's epithelial cells, however, was approximately 0.71%, higher than that of the tuft cells. These findings may contribute to a better understanding of the mechanisms of cellular interplay within the glomeruli.

Animals↗
PubMed1993

Page kidney with constrictive perinephritis.

We describe a case of Page kidney following an infectious urinoma complicated by a pyelolithotomy. The most characteristic finding was the fact that this case resulted from constrictive perinephritis, not from any usual etiology such as perirenal hematoma. Knowledge of the patient's medical history and split venous renin measurements were helpful in making a diagnosis. She had refractory hypertension during conservative medical therapy. Finally, a nephrectomy improved her hypertension. The value of venous renin sampling for reaching a diagnosis, and the medical and surgical therapeutic options are discussed. This report also reviews all previously described cases of Page kidney without hematomas.

Constriction, Pathologic↗
PubMed1991

Case report: hypothyroidism as a possible cause of an acquired reversible hemolytic anemia.

The lipid composition of the red cell membrane and plasma was investigated in a patient with hypothyroidism, in whom an acquired hemolytic anemia was reversed after thyroid hormone replacement therapy. Before therapy, most of the plasma lipids were elevated. In the red cell membrane, phosphatidylcholine (PC) and free cholesterol (FC) were increased, and the free cholesterol to phospholipid (FC/PL) ratio was elevated. Erythrocyte sodium transport was also increased, while intracellular sodium and potassium concentrations were normal. After therapy, the derangement of lipid levels and sodium transport activity were normalized with improvement of the hemolytic anemia. The shape of peripheral red cells also returned to normal after treatment. These findings suggest that the derangement of the red cell membrane lipids and plasma lipids derived from hypothyroidism can be a major cause of hemolysis in this patient.

Adult↗
PubMed1991

[A case report on tuberculosis with remittent fever after tonsillectomy in a patient under CAPD].

This report pertains to a case of chronic renal failure with remittent fever after tonsillectomy. The patient was 45-year-old female who had been undergoing continuous ambulatory peritoneal dialysis (CAPD) for five years. She was admitted to our hospital after being diagnosed as having pyrexia with tonsillitis. A tonsillectomy was performed. Although several symptoms and signs, such as fever, positive CRP and accelerated ESR, improved transiently by the seventh postoperative day, remittent fever and cervical lymph node swelling suddenly recurred after the eighth postoperative day. In spite of the antibiotic therapy, the fever continued for two weeks thereafter. A culture to check for acid-fast bacilli was negative, but on epithelioid cell granuloma with a small central abscess was found in the biopsy specimen of the lymph node. INH was prescribed to her. After three days of INH administration, the patient became afebrile. Patients with long-term dialysis are known to be very susceptible to tuberculous diseases. However, to date, there has been no report of tuberculosis being accompanied by a fever after a tonsillectomy. As it might be difficult to make a tubercular diagnosis on such a febrile patient, early antituberculous chemotherapy is recommended for patients with antibiotic-refractory fever.

Female↗
PubMed1990

Treatment of a patient with end-stage renal disease, severe iron overload and ascites by weekly phlebotomy combined with recombinant human erythropoietin.

A 41-year-old hemodialyzed woman developed ascites and was found to have secondary iron overload. The dose of administered iron was approximately 11-12 g, and her serum ferritin level was 15,000 ng/ml (15,000 micrograms/l). There were no signs of congestive heart failure, fluid overload, or liver cirrhosis. A program of weekly phlebotomy combined with recombinant human erythropoietin (rhEPO) therapy was tried to eliminate the iron congestion. After 9 months of this therapy, about 5 g of iron had been removed. The ascites completely disappeared, and her serum ferritin level fell to 5,800 ng/ml (5,800 micrograms/l). This suggests that such combined therapy would be useful when iron overload must be corrected rapidly. Before therapy, the sterile ascitic fluid showed exudative characteristics with 3.7 g/dl (37 g/l) of total protein. The serum-ascites albumin difference was 0.6 g/dl (6 g/l), and the fluid contained 1,400 inflammatory cells/mm3 (1.4 X 10(9)/l). Notably, the serum-ascites albumin difference increased in parallel with iron elimination. These findings suggested that iron deposition may have played a role in changing the permeability of the peritoneum, or in impairing lymphatic drainage, both of which are presumed to be pathogenetic factors of nephrogenic ascites.

Adult↗
PubMed1990

Antimouse laminin antibodies in IgA nephropathy and various glomerular diseases.

IgG, IgA and IgM class antibodies to mouse laminin and human fibronectin in sera from patients with various glomerular diseases (50 cases of IgA nephropathy, 5 cases of minimal-change nephrotic syndrome; 6 cases of membranous nephropathy, 5 cases of systemic lupus erythematosus, 2 cases of Henoch-Schönlein purpura, 3 cases of poststreptococcal nephritis and 4 cases of preeclampsia) and from 30 normal controls were tested using a solid-phase enzyme-linked immunosorbent assay method. IgA antimouse laminin antibody titers in sera from IgA nephropathy patients were significantly higher (p less than 0.05) than in controls. There were no statistical differences in IgA antimouse laminin antibody titers between patients with other glomerular diseases and normal controls. IgM antimouse laminin antibody was significantly raised (p less than 0.01) in sera from patients with preeclampsia. The reaction of mouse laminin with the IgA nephropathy and preeclampsia sera on each of the IgA and IgM assay systems was inhibited by the antigen at up to 5 micrograms/ml. However, it was not inhibited by anti-C3d, anti-C1q, anti-J chain and antisecretory component sera or saccharides. The reaction of mouse laminin with an exceptionally high-titer IgA antimouse laminin antibody serum from a normal control on the IgA assay system was clearly inhibited by 1 mM of melibiose, which contains alpha-galactosyl residues. The same concentration of melibiose, however, did not inhibit the reaction of mouse laminin with IgA nephropathy sera on the same assay system. Treatment of mouse laminin with alpha-galactosidase did not alter any binding from IgA nephropathy sera but binding was lost from an exceptionally high-titer normal control serum. There were no correlations between serum IgA level and IgA antimouse laminin antibody titer in sera from IgA nephropathy patients. Immunoblot techniques revealed the presence of antibody in sera from IgA nephropathy patients reacting with both subunits A and B of laminin, somewhat stronger with laminin A. None of the sera tested contained antifibronectin antibodies. These results indicate that the IgA antimouse laminin antibody is a specific antibody in IgA nephropathy and might play a role in the pathogenesis of the nephritis since mouse laminin and human mesangial laminin present a common epitope.

Adolescent↗
PubMed1990

Aromatase inhibitors in cigarette smoke, tobacco leaves and other plants.

A chance observation that cigarette smoke interferes with the aromatase assay led us to investigate tobacco leaf and smoke extracts for the presence of aromatase inhibitors. The highest inhibitory activity was found in the basic fraction of cigarette smoke. Further purification of this fraction led to the identification of N-n-octanoylnornicotine. Synthesis and testing of a series of acylated nornicotines and anabasines for their ability to inhibit aromatase showed an interesting correlation of activity with the length of the acyl carbon chain, with maximum activity at C-11. The acylated derivatives showed activity which was significantly greater than that of nicotine and anabasine. In vivo studies in rats indicated that administration of this inhibitor delayed the onset of NMU-induced breast carcinoma and altered the estrus cycle. These in vivo studies suggest that tobacco alkaloid derivatives exert their effects by suppression of the aromatase enzyme system. Toxicity studies indicated relatively low toxicity with LD50 for N-n-octanoylnornicotine = 367 mg/kg body weight. When extracts from thirty five varieties of vegetables, plant leaves, and fruits were analyzed, seventeen showed quantitatively significant aromatase inhibition which was comparable to that of green tobacco leaf, suggesting that naturally occurring substances may affect endocrine function through aromatase inhibition.

Anabasine↗
PubMed1990

Focal glomerular sclerotic lesions in a patient with unilateral oligomeganephronia and agenesis of the contralateral kidney: a case report.

An open renal biopsy specimen from a twelve-year-old boy with a congenital solitary kidney was studied with light, electron, and fluorescent microscopy. Focal glomerular sclerotic lesions were disclosed by these microscopic examinations. Morphometric analysis revealed statistically significant hypertrophy of the glomeruli and significant reduction in the number of glomeruli when compared with controls of similar age. These findings suggested that not only the loss of one kidney, but also congenital reduction of nephrons contributed to the development of focal glomerular sclerotic lesions in this patient. There have been five reported cases of unilateral renal agenesis with oligomeganephronia in a solitary kidney [Van Acker et al. 1971, Griffel et al. 1972, Lam et al. 1982, Bhathena et al. 1985]. Our case, therefore, would be the sixth such case.

Biopsy↗