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Biomedical subjects

H Nishitani

Publications and source records attributed to H Nishitani.

At least 109 records · Page 6Linked to original sources
PubMed1992

Evidence for the presence of differently glycosylated forms of prorenin in the plasma of anephric man.

Previously, we unexpectedly observed that plasma inactive renin (trypsin-activatable renin) in bilaterally nephrectomized rats is not prorenin. To determine whether plasma inactive renin in anephric man is prorenin, we examined the immunological and biochemical properties of plasma inactive renin from five anephric patients. There were significant concentrations of inactive renin (5.33 +/- 2.08 ng/L.s) in plasma of anephric patients, while active renin was negligible (0.06 +/- 0.01 ng/L.s). The inactive renin from anephric patients could be immunoprecipitated 97 +/- 1% by specific antiserum against the prosegment portion of prorenin. Specific antimature renin serum completely inhibited the angiotensin-I-generating activity of inactive renin induced by trypsin treatment. The molecular mass of inactive renin from anephric patients (49.0 +/- 0 kDa), estimated by gel permeation high performance liquid chromatography, was similar to that of normal human plasma prorenin (48.2 +/- 0.8 kDa). These results indicate that plasma inactive renin in anephric man is prorenin, findings different from our previous observations obtained in anephric rats. Concanavalin-A chromatography separated inactive renin from anephric patients into three forms, including the column-unbound form, the loosely bound form, and the tightly bound form. Thus, in anephric man, differently glycosylated multiple forms of prorenin are released into the circulation from an extrarenal organ(s).

Adult↗
PubMed1992

Intraarterial lymphocyte-injection therapy for lymphedema of the leg: an examination using indium-111 oxine labeled autologous lymphocytes.

A 58-year-old female patient with lymphedema of the left leg was treated by repeated intraarterial lymphocyte-injection therapy. To elucidate whether the injected lymphocytes act at the affected site of the leg, we examined the distribution of the In-111 oxine labeled lymphocytes injected into the proximal artery to the affected leg in comparison with the distribution in the other, healthy, leg. The radioactivity of the affected leg was almost two times higher than that of the healthy leg during the first 30 min after injection, and it remained higher even after 24 hours. The circumference of the affected leg of the patient decreased steadily during her hospital stay. These results, together with the clinical findings, suggest that some of the intraarterially-injected lymphocytes remained in the affected leg at least 24 hours and might play some role in reducing the volume of lymphedematous fluid.

Blood Component Transfusion↗
PubMed1992

Accuracy of the results measured by in vivo 1H-MRS using model solutions.

In in vivo 1H-MRS of human brain, main three metabolites such as N-acetyl-L-aspartate (NAA), creatine/phosphocreatine (PCr/Cr), and choline (Cho) have been observed. In this paper an accuracy of the results measured by in vivo 1H-MRS using above model solutions was discussed. 1.0 mmol/l choline and 1.5 mmol/l creatine/phosphocreatine saline solutions were measured with STEAM method (echo time 270 msec). The peak area of Cho was larger than that of PCr/Cr against their concentrations and was linearly increased with its concentration in the range of 5.8 and 29 mumol/27 cm3. Although both peak areas of Cho and Cr/PCr were varied with Volume-of-interest (VOI) coordinates, the ratio of Cho to PCr/Cr was approximately 1.6.

Brain↗
PubMed1992

Quantified application of MRI for diagnosis of head and neck tumors.

We evaluated T/M ratios and T2 values of 6 malignant lymphomas and 8 squamous cell carcinomas in the head and neck in order to differentiate these two entities. T/M ratios were calculated by dividing intensity of tumor by that of muscle in same slice images. T2 values were calculated from T2-weighted images and proton-weighted images. Statistical difference of T/M ratios was found between malignant lymphomas and squamous cell carcinomas, but no difference of T2 values was seen between two groups. T/M ratio was considered to be a useful and quantified index for evaluation of head and neck tumor.

Carcinoma, Squamous Cell↗
PubMed1992

High serum lipoprotein(a) concentrations in uremic patients treated with continuous ambulatory peritoneal dialysis.

We measured serum lipoprotein(a) [Lp (a)] concentrations in 50 uremic patients treated on continuous ambulatory peritoneal dialysis (CAPD) and compared them with those in 29 uremic patients on hemodialysis (HD) and those in 62 normal controls. The median values were 47.9 mg/dl in CAPD patients, 25.2 mg/dl in HD patients, and 11.7 mg/dl in controls, respectively. These differences were statistically significant when assessed by Kruskal-Wallis test (p < 0.0001). Thirty-five out of 50 patients on CAPD (70%) and 12 out of 29 patients on HD (41%) had Lp(a) concentrations above 30 mg/dl, whereas these high values were observed in only 15% of normal controls. This difference in prevalence of high Lp(a) was also significant by 2 x 3 chi-square test (p < 0.01). There was a significant positive correlation between Lp(a) and apolipoprotein B (r = 0.517, p < 0.0001). In CAPD patients, 9 with ischemic heart disease had a significantly higher median Lp(a) than those without it (67.4 vs 40.9 mg/dl, p < 0.01 by Mann-Whitney U-test). These results suggest that high levels of serum Lp(a) might contribute to an increased risk for ischemic heart disease in CAPD patients, and that there may be a relationship between Lp(a) and apolipoprotein B metabolism in CAPD patients.

Adult↗
PubMed1992

In vivo 19F MR spectroscopic study of metabolism of 5-fluorotryptophan in rat liver.

The metabolism of 5-fluorotryptophan in rat liver was examined by in vivo 19F MR spectroscopy. After i.v. injection of 200 mg/kg b.w. of 5-fluorotryptophan the substance was noted immediately as a strong peak, which decreased gradually. Another peak appeared about 40 min after the injection. The chemical shift value of this peak was 1.6 ppm from that of 5-fluorotryptophan. Kynurenine is known to be a major metabolite of tryptophan in the liver. We synthesized 5-fluorokynurenine from 5-fluorotryptophan by ozonolysis. The chemical shift value of 5-fluorokynurenine was confirmed to be coincident with that of the metabolite peak. This strongly suggests that the metabolite peak of 5-fluorotryptophan observed in this study was the 5-fluorokyrurenine signal. We also applied this method for the CCl4-injured liver. In the liver injury group, the metabolite peak appeared slowly and the intensity was low compared to that of the normal group, though the peak of 5-fluorotryptophan decreased similarly as in the normal liver. These results suggest that the decrease of 5-fluorotryptophan is due mainly to the renal excretion, as the injured liver could not metabolize 5-fluorotryptophan.

Animals↗
PubMed1991

Anti-skeletal muscle and anti-acetylcholine receptor antibodies in patients with thymoma without myasthenia gravis: relation to the onset of myasthenia gravis.

We measured the anti-skeletal muscle (SM) antibody titers in sera from 46 patients with thymoma but without Myasthenia gravis (MG) in order to determine whether the presence of anti-SM antibody is linked to the combination of thymoma-MG, or to thymoma alone. We detected anti-SM antibodies in 18 of these sera, of which 15 had concomitantly elevated titers of anti-AChR antibodies. Moreover, 9 of whom had experienced the onset of MG after surgery. In contrast, no patient without elevations in both antibodies developed MG during the followup. We conclude that the presence of anti-SM antibodies is linked strongly with thymoma associated with MG, but not with thymoma alone.

Adolescent↗
PubMed1991

Loss of RCC1, a nuclear DNA-binding protein, uncouples the completion of DNA replication from the activation of cdc2 protein kinase and mitosis.

The temperature-sensitive mutant cell line tsBN2, was derived from the BHK21 cell line and has a point mutation in the RCC1 gene. In tsBN2 cells, the RCC1 protein disappeared after a shift to the non-permissive temperature at any time in the cell cycle. From S phase onwards, once RCC1 function was lost at the non-permissive temperature, p34cdc2 was dephosphorylated and M-phase specific histone H1 kinase was activated. However, in G1 phase, shifting to the non-permissive temperature did not activate p34cdc2 histone H1 kinase. The activation of p34cdc2 histone H1 kinase required protein synthesis in addition to the presence of a complex between p34cdc2 and cyclin B. Upon the loss of RCC1 in S phase of tsBN2 cells and the consequent p34cdc2 histone H1 kinase activation, a normal mitotic cycle is induced, including the formation of a mitotic spindle and subsequent reformation of the interphase-microtubule network. Exit from mitosis was accompanied by the disappearance of cyclin B, and a decrease in p34cdc2 histone H1 kinase activity. The kinetics of p34cdc2 histone H1 kinase activation correlated well with the appearance of premature mitotic cells and was not affected by the presence of a DNA synthesis inhibitor. Thus the normal inhibition of p34cdc2 activation by incompletely replicated DNA is abrogated by the loss of RCC1.

Animals↗
PubMed1991

Mutation of the hamster cell cycle gene RCC1 is complemented by the homologous genes of Drosophila and S.cerevisiae.

The RCC1 gene has been isolated from several vertebrates, including human, hamster and Xenopus. Genes similar to RCC1, namely BJ1 and SRM1/PRP20, have been isolated from the insect Drosophila and from the budding yeast Saccharomyces cerevisiae. A mutation of the RCC1 gene in the hamster BHK21 cell line, tsBN2, confers pleiotropic phenotypes, including G1 arrest and premature induction of mitosis in cells synchronized at the G1/S boundary. Similarly, mutations of the SRM1/PRP20 gene are pleiotropic; the srm1 mutant shows G1 arrest and suppression of the mating defect of mutants lacking pheromone receptors, and the prp20 mutant shows an alteration in mRNA metabolism. Here we show that both BJ1 and SRM1/PRP20 complement the temperature sensitive phenotype of the tsBN2 cells. Like RCC1 proteins of vertebrates, the protein products of the Drosophila and yeast RCC1 homologues were located in the nuclei of the mammalian cells. These results suggest that the BJ1 and SRM1/PRP20 genes are functionally equivalent to the vertebrate RCC1 genes, and that the RCC1 gene plays an important role in the regulation of gene expression in the eukaryotic cell cycle.

Amino Acid Sequence↗
PubMed1991

Comparison of reliability of plasma fructosamine and glycosylated hemoglobin assays for assessing glycemic control in diabetic patients on hemodialysis.

To search for a reliable marker of medium-term integrated blood glucose level in diabetics on maintenance hemodialysis (HD), plasma fructosamine and glycosylated hemoglobin (Hb) levels were determined every week and blood glucose levels were determined four times every day over 3 weeks. The mean values of fructosamine (mol/L per 40 g of albumin) and of glycosylated Hb of other the study period correlated (r = .746, P less than .001) for combined materials of diabetic and nondiabetic subjects. However, plasma fructosamine values at the end of the study period did not correlate with the overall mean blood glucose values during the preceding 8 to 21 days (r = .372, NS). In contrast, glycosylated Hb values correlated closely with the same mean blood glucose values (r = .703, P less than .001). Fructosamine values significantly decreased during a HD, irrespective of the increases in albumin and total protein. In conclusion, glycosylated Hb was a reliable marker of long-term integrated blood glucose even in diabetics on HD. However, fructosamine was not a reliable marker of medium-term integrated blood glucose in these patients.

Blood Glucose↗
PubMed1991

Roles of hypoalbuminemia and lipoprotein lipase on hyperlipoproteinemia in continuous ambulatory peritoneal dialysis.

To assess the mechanism of serum lipoprotein abnormalities in continuous ambulatory peritoneal dialysis (CAPD), we measured serum lipids, apolipoproteins, and postheparin lipases in 46 patients with end-stage renal disease (ESRD) treated on CAPD, 26 patients on hemodialysis (HD), and 29 healthy subjects. HD patients had higher serum triglyceride levels than the healthy controls, showing type IV and type III phenotypes. They had significantly lower activities of hepatic triglyceride lipase (HTGL) in postheparin plasma compared with controls, and postheparin lipoprotein lipase (LPL) was also decreased by 15%, although the latter change was not statistically significant. CAPD patients had elevated levels in triglyceride, total cholesterol, low-density lipoprotein cholesterol (LDL-C), and apolipoprotein (apo) B, showing type IV, III, and II (IIb and IIa) phenotypes. The mean LPL and HTGL activities in CAPD patients were not different from those of HD patients. CAPD patients with hyperlipoproteinemia had significantly higher serum albumin levels than those with normolipidemia. There was a significant positive correlation between albumin and apo B levels in CAPD patients. In hyperlipidemic CAPD patients, there was no difference in serum albumin concentrations or HTGL activities among lipoprotein phenotypes, whereas LPL activities were significantly higher in the patients with type II than those with type IV hyperlipoproteinemia. These results suggest that there was some linkage between alterations in serum albumin and lipoproteins, and that LPL was related to phenotypic variation of hyperlipoproteinemia in CAPD.

Apolipoproteins↗
PubMed1991

A nationwide collaborative study on the long-term effects of bromocriptine in patients with Parkinson's disease. The fourth interim report.

The interim results of the nationwide collaborative study on the long-term effects of bromocriptine in patients with Parkinson's disease are reported. Four years ago, two prospective clinical studies were started to evaluate the long-term effects of bromocriptine in Parkinson's disease. The first was to investigate the long-term effects of bromocriptine monotherapy and the second to see the long-term effects of a combination therapy of bromocriptine with levodopa. Patients who had never been treated with levodopa were placed on bromocriptine monotherapy, and those who had been treated with levodopa for not more than 5 years were allocated randomly to either the combination or the levodopa group. Two hundred and eighty-six patients were enrolled in the former study and 416 in the latter. Among the 286 patients, 164 continued for further observation at the end of the fourth year, and 74 of them were still being treated with bromocriptine monotherapy. However, in 78, levodopa had to be added. Among the 416 patients in the second study, 216 were allocated to the combination group and 200 to the levodopa control group. At the end of the fourth year, 130 in the former and 140 in the latter group remained for further observation. In all three groups, a gradual loss of efficacy was noted. The rate of efficacy loss appeared largest in the monotherapy group and smallest in the combination group. Effects on tremor and rigidity are still maintained, but effects on akinesia and gait were lost by the end of the fourth year in all groups. Wearing-off and dyskinesias seem to be better managed by the combination therapy. The incidence of wearing-off was very small in the monotherapy group. No serious side effects were encountered except for 1 patient who died of pulmonary fibrosis in the combination group.

Bromocriptine↗
PubMed1991

Decreased bone mineral density in diabetic patients on hemodialysis.

Renal osteodystrophy in hemodialyzed patients with DM-HD shows different features from that in non-DM,HD. Two studies were done. One was a comparison of BMD in 30 non-DM,HD patients and 30 DM-HD patients. The second was a comparison of possible factors affecting calcium metabolism in the higher and lower BMD groups (n = 20/21) in the DM-HD patients. BMD was measured by dual-energy X-ray absorptiometry (DEXA; Hologic QDR 1,000/W) in the third lumbar vertebra (L3), head, pelvis, and whole body. The BMDs of the DM-HD group were lower in these areas and whole body than that in the non-DM,HD group. A significant difference was found in the head BMD (p less than 0.05). In the second study, factors which may contribute to the differences in BMD were compared in the DM-HD patients divided into higher and lower BMD of the head. The group with higher head BMD had a value 110% of the mean value or more. Clinical and biochemical test results (age, the time since the first dialysis, body weight, the degree of obesity, height, serum calcium, serum phosphate, serum aluminum, serum c-PTH level and the dose of 1 alpha-OH-D3) were compared. The degree of obesity of the patients with higher BMD was significantly larger than that with lower BMD (p less than 0.005).

Aged↗
PubMed1991

A multi-center, double-blind study on slow-release bromocriptine in the treatment of Parkinson's disease.

We report on the clinical efficacy of a slow-release formulation of bromocriptine studied in a multi-center, double-blind trial using standard bromocriptine as the control. We randomly allocated enrolled patients (N = 243) to either the slow-release or normal bromocriptine group. Sixty of them were de novo patients. The maintenance dose of slow-release bromocriptine was 14.2 +/- 0.7 mg/d and that of standard bromocriptine 13.5 +/- 0.7 mg/d (mean +/- SE). The slow-release formulation was taken twice and the standard three times a day. Forty-one percent of the patients treated with the slow-release bromocriptine and 32% of the patients treated with the standard bromocriptine showed moderate or marked improvement in the global improvement rating. There were no serious side effects, and the frequency of vomiting and epigastric discomfort was lower in the patients treated with the slow-release bromocriptine. Clinical efficacies for tremor, rigidity, akinesia, and gait disturbance were comparable between the two drugs tested. The slow-release bromocriptine seems to be a valuable drug for the treatment of Parkinson's disease with less severe side effects than regular bromocriptine.

Aged↗