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Biomedical subjects

S Katayama

Publications and source records attributed to S Katayama.

512 records · Page 29Linked to original sources
PubMedDate not supplied

Risk of liver cirrhosis and hepatocellular carcinoma in subjects with hepatitis B and delta virus infection: a study from Kure, Japan.

To investigate the effect of hepatitis delta virus (HDV) superinfection on the long-term outcome of Japanese subjects with chronic hepatitis B virus (HBV) infection, we examined the presence of antibodies to hepatitis delta antigen (anti-HD) in serial serum samples collected from 1127 subjects with chronic HBV infection. The subjects were followed for at least 36 months (mean: 121.3 months) between 1973 and 1991. Among 69 cases where anti-HD was detected, eight (12%) developed liver cirrhosis (LC) and six (9%) developed hepatocellular carcinoma (HCC). However, among 1058 cases without anti-HD, there were 43 patients (4%) who developed LC and 29 (3%) who developed HCC. The prevalence of LC and HCC was significantly higher among the cases with anti-HD than those without anti-HD. The proportion of LC and HCC per 1000 person years was 10.46 and 7.84, respectively among cases with anti-HD, and 4.05 and 2.73 among those without anti-HD, respectively. The overall relative risk of LC and HCC was 2.58 and 2.87, respectively; 95% confidence interval (CI): LC, 1.14-5.13; HCC, 1.03-6.23. These results indicate that in the Kure district in Japan, where HDV infection of persons infected with HBV is about 6%, such superinfection increases the risk of LC and HCC.

Adolescent↗
PubMedDate not supplied

Prenatal diagnosis of Duchenne muscular dystrophy by polymerase chain reaction analysis.

The efficacy of the polymerase chain reaction (PCR) in the first-trimester prenatal diagnosis of Duchenne muscular dystrophy (DMD) was examined. Twenty-seven fetuses from 26 Japanese pedigrees at risk for DMD were analyzed. PCR-restriction fragment length polymorphism analysis, multiplex PCR, and dinucleotide repeat polymorphism analysis were used. Of 16 males, 11 were determined to be unaffected, 4 were affected, and the remaining 1 was undetermined. Of the 11 female fetuses, 1 was diagnosed as a noncarrier, 4 were carriers, and the carrier status of the remaining 6 was not determined at the option of the patients, although DNA polymorphisms could be detected in those patients. Prenatal diagnosis by PCR analysis was possible in 96% of the fetuses tested (26 of 27).

Exons↗
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Hypertension in experimental diabetes mellitus. Renin-prostaglandin interaction.

To investigate mechanisms involved in the high incidence of hypertension in diabetes mellitus, the relationship between renin-angiotensin production and renal prostaglandin E2 synthesis was studied in rats 1 week after diabetes mellitus had been induced by streptozotocin injection. The diabetic rats became hypertensive, although plasma renin activity did not increase despite the plasma volume contraction resulting from polyuria and natriuresis. Subcutaneous insulin injection resulted in a marked increase in plasma renin activity, while more rigid control of diabetes mellitus achieved by constant insulin infusion decreased blood pressure. Cortical renin content and renin release as well as papillary prostaglandin E2 synthesis in vitro were significantly lower in diabetic rats than in nondiabetic controls. Isoproterenol and prostaglandin E2 stimulated renin release in controls, while diabetic rats responded only to isoproterenol. Insulin infusion by pump reversed these abnormalities. An additive effect of a maximum dose of isoproterenol (10(-5) M) and prostaglandin E2 (10(-4) M) on renin release was observed in nondiabetic controls and in diabetic rats treated with insulin pump, but not in untreated diabetic rats. The results suggest that 1) renal renin release and prostaglandin E2 synthesis in diabetes mellitus are insulin dependent, 2) inappropriately lower plasma renin activity in diabetes mellitus may be attributed to a diminished renal renin pool and a lack of renin release in response to renal prostaglandin E2, the synthesis of which is also impaired in diabetes, prostaglandin E2-induced renin release may operate independently from isoproterenol-induced renin release, and impaired renal prostaglandin E2 synthesis may contribute to the development of hypertension in the face of an unchanged prohypertensive renin-angiotensin II system.

Animals↗
PubMedDate not supplied

The telmisartan renoprotective study from incipient nephropathy to overt nephropathy--rationale, study design, treatment plan and baseline characteristics of the incipient to overt: angiotensin II receptor blocker, telmisartan, Investigation on Type 2 Diabetic Nephropathy (INNOVATION) Study.

We planned the INNOVATION study to determine whether telmisartan, an angiotensin-2-receptor blocker, delays the progression of renal disease from incipient nephropathy to overt nephropathy in hypertensive or normotensive Japanese patients with type 2 diabetes mellitus. The INNOVATION study is a randomized, double-blind, placebo-controlled trial. Eligible patients must have incipient nephropathy (defined as a urinary albumin to creatinine ratio of 100-300 mg/g creatinine) and a serum creatinine concentration of < 1.5 mg/dl for men and < 1.3 mg/dl for women. Patients who need treatment with angiotensin II receptor blockers or angiotensin-converting enzyme inhibitors are excluded. Eligible patients are randomly assigned to three groups: telmisartan titrated to 40 mg; telmisartan titrated to 80 mg; or placebo. The primary endpoint is the time from baseline visit to first detection of overt nephropathy (defined by a urinary albumin to creatinine ratio that is > 300 mg/g creatinine and 30% higher than the baseline on at least two consecutive visits). A total of 1855 patients have been enrolled from 160 study centres. In 527 randomized patients (28.4% of the enrolled patients), mean (SD) urinary albumin to creatinine ratio and serum creatinine concentration at baseline were 173.3 (47.2) mg/g creatinine and 0.78 (0.19) mg/dl. Sixty-eight per cent of the patients had hypertension at baseline. Mean (SD) systolic and diastolic blood pressures at baseline were 137.1 (14.6) and 77.5 (10.3) mmHg. The INNOVATION study will determine whether telmisartan, an angiotensin II receptor blocker, provides clinical benefits in hypertensive or normotensive patients with diabetes mellitus and diabetic nephropathy.

Aged↗
PubMedDate not supplied

Gallyas- and tau-positive glial structures in motor neuron disease with dementia.

We have studied Gallyas- and tau-positive glial structures in three autopsied cases of motor neuron disease with dementia (MND-D). Gallyas-positive, tau-immunoreactive thread-like structures in the neuropil and crescent/coiled inclusions in the glial cells were mainly observed in the hippocampus, parahippocampal gyrus, and amygdaloid nucleus. Double staining using Gallyas staining and carbonic anhydrase 2 (CA2) immunohistochemistry revealed that some crescent/coiled inclusions occurred in the CA2-immunopositive cytoplasm of the oligodendroglia. Electron microscopic study with the Gallyas-Braak method revealed that the inclusion was a reticular, partly compact mass, containing 15 nm fibrils around round or oval nuclei. Since the regions where these structures appeared exhibited neuronal loss with gliosis, these data suggest that a cytoskeletal abnormality involving tau protein in glia might be associated with the degenerative process of MND-D.

Aged↗
PubMedDate not supplied

Effect of polaprezinc on healing of acetic acid-induced stomatitis in hamsters.

PURPOSE: The purpose of this work was to investigate the potential effectiveness of polaprezinc in the treatment of stomatitis. Its effect on oral mucous membrane lesions was studied focusing on acetic acid-induced stomatitis in an animal model. METHOD: Stomatitis was induced in hamsters by local injection of 30 microL of 10% acetic acid solution into both cheek pouches. Change of the size of the acetic acid-induced white lesion caused by polaprezinc injection was compared with that of control (water injection). The process of healing of damaged membrane was also investigated histopathologically. Selective adhesion of polaprezinc on mucous membrane was studied using color development by complexation between zinc and dithizone. RESULTS: On day 4 after acetic acid injection, round white lesions were observed in the central area of both pouches. Observation on days 7, 10, and 14 showed that the size of the lesions decreased with time. Comparison with the control group of animals, in which healing took place naturally, showed that daily administration of polaprezinc (10 mg/kg) applied to the cheek pouches significantly promoted healing of the lesion from day 7 onward. Histopathological investigation of the mucous membrane in the cheek pouches 7 days after the induction of stomatitis by acetic acid injection showed thickening, and cell damage was evident. In the group of animals treated with polaprezinc, the thickening of the mucous membrane was less than that in animals of the group receiving no treatment and regeneration of damaged tissue was observed after 6 days of polaprezinc treatment. CONCLUSION: Polaprezinc is an effective treatment in this animal model of acetic acid-induced stomatitis. This suggests that the drug may be useful in promoting healing of stomatitis in the clinical setting. Extrapolating these to humans suggests that the drug has healing effect to severe stomatitis induced by anticancer drug therapy.

Acetic Acid↗
PubMedDate not supplied

Functional brain studies with H2(15)O-PET: strategies and problems for approaching higher brain functions with H2(15)O-PET.

Activation study using H2(15)O and PET is promising as a noninvasive approach to higher brain functions in humans. However before reaching a more complex paradigm, many fundamental problems need to be solved. In this study, we investigated the following issues: (1) reproducibility of regional cerebral blood flow in the resting state as measured by this method, (2) effect of physiological stimulation on cerebral blood flow, and (3) identification of activated areas on anatomical structures. Our data suggest that relative CBF images and their paired subtraction are more suitable for tapping functional localization. Changes in rCBF in the association cortex for more complicated tasks are, in general, smaller than those in the primary cortex. Combined display of PET images with three-dimensional reconstructed brain surface MR images was the most reliable technique for anatomical identification of the activated site.

Acoustic Stimulation↗