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Biomedical subjects

S Yamagami

Publications and source records attributed to S Yamagami.

At least 127 records · Page 7Linked to original sources
PubMed1990

Correlation between blood prostaglandins, plasma lipids and atherosclerosis in dialyzed patients.

The correlations between the degree of atherosclerosis, plasma prostaglandins (PGs) and plasma lipids were examined in maintenance hemodialyzed patients with and without diabetes mellitus. The degree of atherosclerosis was evaluated by pulse wave velocity (PWV) of the aorta. Plasma PGs were radioimmunoassayed. PWV was significantly higher in hemodialyzed patients compared to sex- and age-matched healthy controls. PWV correlated with the plasma thromboxane A2 (TXB2) level and TXB2/6-keto-PGF1 alpha ratio in hemodialyzed patients, without a significant difference between the diabetic and nondiabetic groups. The plasma lipid profile was type IV of the WHO classification in both the diabetic and nondiabetic groups, and PWV did not correlate with these lipid abnormalities. Though not significantly, the decreases in plasma PGE2 and 6-keto-PGF1 alpha and the increase in TXB2 correlated with the degree of type IV hyperlipidemia. The results suggest that plasma PG abnormalities might correlate with the degree of atherosclerosis in hemodialyzed patients.

Adult↗
PubMed1990

Novel endotoxin adsorbing materials, polymyxin-sepharose and polyporous polyethylene membrane for removal of endotoxin from dialysis systems.

In order to remove contaminated endotoxin from dialysis systems, we prepared and investigated two novel endotoxin adsorbing materials, Polymyxin-Sepharose (PxSeph) and polyporous polyethylene hollow fiber membrane (EHF). PxSeph was prepared by covalently immobilizing polymyxin B on Sepharose 4B beads by CNBr coupling method. It adsorbed various endotoxins with a high affinity constant and could effectively remove endotoxin from aqueous solution and human plasma. EHF also removed endotoxins from contaminated water by filtration through EHF modules, and its adsorption nature was demonstrated. Both PxSeph and EHF are stable in physiological conditions and proved to be useful adsorbents for removal of contaminated endotoxin from the hemodialysis systems.

Adsorption↗
PubMed1990

Detection of endotoxin antibody in long-term dialysis patients.

Endotoxins are often seen in dialysate. They are derived from Gram-negative bacteria especially Pseudomonas, E. coli and Serratia. Endotoxins are large-molecular-weight substances with an average molecular weight of 10(8). These large units can be divided into subunits down to a molecular weight of 10,000 which are thought to pass through dialyzer membranes. To investigate this, endotoxin antibody levels were measured in two groups of patients on chronic regular hemodialysis, a low-flux group using cellulosic membrane dialyzers (cuprophan and cuproammonium rayon (CAR) and a high-flux group using synthetic polymer membrane dialyzers (PMMA, EVAL). Using an ELISA based on standard endotoxin antibodies the percentages of patients in the low flux group with endotoxin antibodies were 26.9% with Cuprophan and 25% with CAR, not significantly different from a normal control group. In the PMMA and EVAL groups, it was 53.6% and 68.4% respectively. Back filtration of dialysate into blood is understood as the main reason for the entry of endotoxin in patients treated with high-flux dialyzers.

Antibodies↗
PubMed1989

Alteration of opioid receptors in seizure-susceptible El mouse brain.

The distribution density of opioid receptors in the brain of El mice (seizure-susceptible strain) was examined to determine the relation between seizures and the opioid system. Saturation curves and Scatchard plots of [3H]2-D-alanine-5-D-leucine enkephalin binding revealed that the opioid delta receptor density in adult El mice during interictal periods was significantly increased in the cerebral cortex, hippocampus, and septal area. It was further shown that the concentration of such receptors in 25-day-old El mice that had no seizures was also significantly increased in the hippocampus and septal area, with no changes in apparent affinities, as compared with in the corresponding regions in ddY mice (seizure-nonsusceptible strain; the mother strain of El). Such up-regulation of opioid receptors in the El mouse brain could result from deficits in endogenous opioid peptides, which could be associated with the pathogenesis of seizure diathesis in the El mouse.

Animals↗
PubMed1989

Alterations in polyadenylic acid-containing messenger RNA synthesis of brain polysomes after seizures of seizure-susceptible E1 mice.

The effect of seizures on synthesis of the polyadenylic acid (poly(A]-containing messenger RNA (mRNA) isolated from brain polysomes in a genetically seizure-susceptible E1 mouse was studied in vivo. The seizure in the E1 mice was induced by tossed-up stimulation. Immediately after the seizure ceased, the labeled orotic acid was injected into the brain. The incorporation rates of labeled orotic acid into poly(A)-containing mRNA isolated from polysomes are represented as the specific radioactivity (SR) (dpm/mg RNA) and the relative specific radioactivity (RSR) (dpm/mg RNA/dpm/mumoles of acid soluble uridine-5'-monophosphate (UMP]. Both the rates were reduced to 70% in SR and 65% in RSR at 1 h after the seizures. This reduction was gradually recovered to the level of interictal E1 mice at 6 h. The seizure-induced alterations are not attributable to the difference in the uridine nucleotide pool because the SR of UMP was not significantly affected by the seizure. The peak of labeled poly(A)-containing mRNA by analysis of gel electrophoresis displaced towards a lower molecular weight at 1 h after the seizures. The RNA showed a higher ratio of AMP and UMP per GMP and CMP in nucleotide composition, implying that this RNA is identical with DNA. These results suggest that the temporary decrease found in cytoplasmic mRNA synthesis induced by the seizures of E1 mice appears to be a result of impaired transcriptional processes in heterogeneous nuclear RNA synthesis and that the smaller mRNA coding for protein associated with seizures is newly synthesized during the postictal period.

Animals↗
PubMed1989

Leukocyte tissue-type plasminogen activator activity in dialysis patients.

Plasma fibrinopeptide B beta 15-42 was significantly high in undialyzed and hemodialyzed chronic renal failure (CRF) patients, indicating that the fibrinolytic system as well as the coagulation system is stimulated. There are two kinds of plasminogen activators (PA) for the fibrinolytic system: urokinase (UK) and tissue-type PA (t-PA). PA activity of peripheral leukocytes from healthy volunteers, continuous ambulatory peritoneal dialysis (CAPD) patients and hemodialysis (HD) patients was measured and compared. Peripheral leukocyte PA in the euglobulin fraction was purified using zinc-chelate-Sepharose 6B column and Concanavalin A-Sepharose column chromatography. The different PA activity was quantitatively identified by electrophoretic enzymography and was confirmed using antibody against UK and t-PA. PA activity of peripheral leukocytes was significantly higher in HD patients on the cupro-ammonium processing membrane dialyzer than in CAPD patients and healthy volunteers. All PA activity in the three groups was UK, and t-PA was not detected. This suggested that the inflammatory response was continuously induced in HD patients, resulting in the induction of PA activity of the leukocytes and plasma, and that different mechanisms were involved for the synthesis or secretion of UK and t-PA.

Adult↗
PubMed1989

Effect of maprotiline combined with conventional neuroleptics against negative symptoms of chronic schizophrenia.

The therapeutic efficacy and target symptoms of maprotiline were tested by administering it in addition to conventional neuroleptic treatment for 10 weeks to a total of 32 chronic schizophrenic patients who showed no, or only partial, response to the neuroleptic medication. The final global improvement rating was 68.8% for all patients. Average therapeutic doses administered were 150 mg per day. Changes in psychotic symptoms were assessed by the Brief Psychiatric Rating Scale (BPRS), Psychiatric Evaluating scale (PES), and the Scale for the Assessment of Negative Symptoms (SANS). All mean improvement rates of these rating scales were observed at the 2nd week after the start of treatment, and maprotiline produced a marked amelioration in negative symptoms such as decreased spontaneity, blunted affect, emotional withdrawal, impaired work or recreation, etc. The incidence of side-effects was 37.5%. Constipation was the most frequently occurring side-effect. Neither side-effects nor laboratory test results were serious enough to discontinue the trial, except in the case of one chronic patient who showed acute exacerbation of symptoms due to maprotiline-induced insomnia, elation and hallucination. These results suggest that maprotiline improves the negative symptoms of schizophrenia by a noradrenaline potentiating action not demonstrated by dopaminergic or serotonergic reward systems.

Adult↗
PubMed1988

A single-blind study of clocapramine and sulpiride in hospitalized chronic schizophrenic patients.

The therapeutic effects, safety and side-effects of clocapramine and sulpiride were evaluated in 52 hospitalized chronic schizophrenic patients using a single-blind method during an 8-week trial period. While the final global improvement rating showed clocapramine to be superior to sulpiride, the differences were not statistically significant. The time course of the total psychiatric rating scales (PRS) showed a progressive decline during treatment for both drugs, and at the end of treatment clocapramine proved significantly lower in total PRS than did sulpiride. In the improvement of psychotic symptoms, clocapramine seemed to be superior to sulpiride with respect to motor retardation, delusion, hallucination or disturbance of self-consciousness, social isolation or withdrawal, and recreation or work. Side-effects appeared more frequently with clocapramine than with sulpiride, but abnormal laboratory-test results appeared less in clocapramine-treated patients than in sulpiride-treated ones. Neither side-effects nor abnormal laboratory-test results induced by the two drugs were severe enough to terminate administration. Clocapramine is concluded to have a more favourable effect on negative symptoms, as well as on some positive symptoms of chronic schizophrenia, than sulpiride.

Adult↗
PubMed1987

Alteration of RNA synthesis in vitro in intact cerebral cortex nuclei induced by convulsions in seizure-susceptible El mice.

We examined the effects of convulsive seizures on in vitro RNA synthesis by cerebral cortex nuclei in El mice. The rate of incorporation of [3H]uridine-5'-triphosphate by intact nuclei during seizures was decreased to 47.4% compared with the rate during the interictal period, but gradually recovered. During the 30-min period after onset of seizures, the rate of RNA synthesis was significantly lower in El mice than in identically stimulated ddY mice. Seizures in El mice had no effect on liver RNA synthesis, suggesting that the alteration of RNA polymerase activity is specific to the brain. Analysis of gel electrophoresis of polyadenylated RNA synthesized in the presence of ammonium sulphate revealed a marked decrease in high-molecular weight RNA species 15 min after seizures in El mice compared with the pattern in nonstimulated ddY mice. This shift from high- to low-molecular weight RNA species was not attributable to RNase activity, but it appeared to be related RNA polymerase.

Animals↗
PubMed1987

Induction of tumouricidal macrophages by MTP-PE: its enhancement by a factor produced spontaneously by tumour cells.

Tumouricidal activity of rat alveolar macrophages is induced by MTP-PE in vitro. This tumouricidal activity is enhanced by a factor (tumour cell derived immunostimulating factor, TCIF) contained in tumour cell culture supernatants. TCIF is not species specific, since culture supernatants of rat MADB-200 as well as mouse B16 or Meth A tumour cells showed similar effects on rat alveolar macrophages. TCIF is not produced in cultures of normal cells, e.g. rat embryo cells. TCIF produced by MADB-200 tumour cells is relatively heat-stable and dialyzable. It is destroyed by treatment at pH 2 for 24 hrs. These results suggest that TCIF can participate in macrophage activation and could be of potential therapeutic value.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1987

Some properties of protein in synaptosomal fractions from El mouse cerebral cortices.

Synaptosomal and TCA insoluble proteins were prepared from the cerebral cortices of El(+) during the interictal periods, El(0) which did not stimulate and convulse at all, the seizure-nonsusceptible ddY mice. Both the proteins analyzed by SDS-PAGE electrophoresis indicated 5 major bands and 20-30 minor bands. In the major bands, 67K protein of the synaptosomal and TCA insoluble proteins in the El(+) mice was significantly lower than those of the ddY or El(0) mice and of the ddY mice, respectively.

Animals↗
PubMed1987

Correlation between blood prostaglandins and blood pressure in chronic renal failure.

Plasma prostaglandins (PGs; PGE2, PGF2 alpha, 6-keto-PGF 1 alpha and TXB2) and plasma renin activity (PRA) were measured in 94 end-stage renal disease (ESRD) patients including 15 undialyzed, 74 maintenance-hemodialyzed and 5 anephric patients, and in 27 healthy controls. In the healthy controls, 6-keto-PGF 1 alpha inversely correlated with age, while TXB2 and the TXB2/6-keto-PGF 1 alpha ratio correlated with age. In the ESRD patients, 6-keto-PGF 1 alpha showed a tendency to decrease with age, and the TXB2/6-keto-PGF 1 alpha ratio significantly correlated with age. The undialyzed group showed significantly higher blood pressure and TXB2 but significantly lower 6-keto-PGF1 alpha compared to the other groups. In the dialyzed group, PGE2 and 6-keto-PGF1 alpha tended to be lower and TXB2 higher compared to the healthy control group. In the dialyzed group, 6-keto-PGF1 alpha correlated inversely with blood pressure independently from PRA. As for PGF2 alpha, it was higher in the undialyzed, dialyzed and anephric groups than in the healthy control group. These results suggested that PGs were involved in blood pressure abnormalities, and that PGI2 played an important role in controlling blood pressure in ESRD patients as one of the depressor factors.

Adult↗
PubMed1986

Sequence complexity of polyadenylate ribonucleic acid in El mouse brain.

To elucidate the sequence complexity of polyadenylate messenger RNA [poly(A+)mRNA] regarding the seizure-susceptible El mouse brain, the proportion of complexity was measured by saturation hybridization using a single-copy DNA (scDNA) with excess RNA. At saturation, 3.81, 3.85 and 4.00% of scDNA hybridized with polysomal poly(A+)mRNAs of El(+), El(O) which had not been convulsed, and ddY (nonsusceptible) mice, respectively. The additive hybridization of a mixture of El(+) and ddY mouse mRNAs was 4.04%. The results suggest that there are considerable overlapping sets within the poly(A+)mRNA sequences between the ddY and El mice, but the complexity of ddY mice mRNA is slightly larger than that of the El mice, whereas poly(A+) heterogeneous nuclear RNA (hnRNA) hybridized with about 18% of scDNA in three strains of mice.

Animals↗