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Biomedical subjects

S Yamagami

Publications and source records attributed to S Yamagami.

At least 145 records · Page 8Linked to original sources
PubMed1985

A crossover study of clocapramine and haloperidol in chronic schizophrenia.

Therapeutic efficacy and target symptoms with clocapramine were compared with those with haloperidol by the crossover method, in a total of 26 chronic schizophrenic patients, by administration of one of the drugs for the first 14 weeks and the other for the next 14 weeks. The final global improvement rating showed no significant difference between the two groups, but clocapramine administered as first drug appeared to have a more pronounced effect than haloperidol. According to the improvement rate in psychotic symptoms, clocapramine tended to be superior to haloperidol for motor retardation, scanty speech and disturbance of thought. In addition the frequency of side-effects was lower with clocapramine than with haloperidol. Neither the side-effects nor abnormal laboratory test results were severe enough to terminate the trial. Clocapramine is considered to be equivalent or superior to haloperidol in terms of anti-psychotic effect in chronic schizophrenia, and is relatively safer than haloperidol.

Adult↗
PubMed1984

Effect of convulsions of the synthesis of heterogeneous nuclear RNA associated with polyadenylate and oligoadenylate sequences from El mouse brain as a convulsive strain.

Animals from the El (susceptible to seizures) and ddy (nonsusceptible) mouse strains were subjected to vestibular stimulation by tossing. After convulsions in the El mice, both the stimulated El mice and ddY mice were intracranially injected with [14C]- and [3H]adenosine, respectively. In the control experiment, nonstimulated El and ddY mice received radioactive adenosines in the same manner. The rate of incorporation of adenosine into brain nuclear RNA, expressed as a percentage of the 3H; 14C ratio, was reduced to an average of 68% at 15 min after convulsions, then increased and reached a control value at 5 h. This reduction in nuclear RNA synthesis was not due to alteration of the adenosine triphosphate pool. Gel electrophoresis of RNA revealed no obvious differences in the labeling distribution between El and ddY mice, but the synthesis of RNA species larger than 35S in heterogeneous nuclear RNA (HnRNA) was impaired in convulsed El mice. Nuclear resistant segments of HnRNA with both T1 RNase and RNase A, were chromatographed with poly(U)-Sepharose followed by urea-polyacrylamide gel electrophoresis. The ologo(A) and poly(A) segments consisted of 29, 19, and 11, and 203, 135, and 69 nucleotides, respectively. The convulsions of El mice reduced the incorporation of radioactive adenosines into oligo(A) and poly(A) segments, suggesting that they inhibited transcription as well as polyadenylation within HnRNA.

Adenine Nucleotides↗
PubMed1984

Trace element concentrations in hair, fingernails and plasma of patients with chronic renal failure on hemodialysis and hemofiltration.

Trace element concentrations in hair and fingernails and plasma of nondialyzed, hemodialyzed and hemofiltered patients with chronic renal failure and healthy volunteers were measured by atomic and flameless atomic absorption spectrophotometry and neutron activation analysis. Plasma aluminum concentrations in all three groups of patients were higher than in the controls. Aluminum levels in plasma and red blood cells were higher in hemofiltered patients than in dialyzed patients. The aluminum concentrations in the hair of both nondialyzed and dialyzed patients was higher than in the controls, while that in the hemofiltered patients it was not. These elevated aluminum concentrations appear to be mainly caused by the use of aluminum-contaminated dialysate. Calcium concentrations in the hair of nondialyzed and dialyzed patients were higher than in the controls. Plasma zinc concentrations in all the patients were lower than the controls, and the concentrations in hemofiltered patients were lower than in the dialyzed patients.

Adult↗
PubMed1983

Muscarinic cholinergic receptors of the convulsive strain (E1) mouse.

The biochemical characteristics of the muscarinic acetylcholine receptors were studied on the E1 strain mouse brain by the binding assay using [3H]1- quinuclidinyl benzylate. Scatchard analyses showed that the receptor density (Bmax) of the hippocampus significantly decreased by 26.4% and the affinity (Kd) increased by 18.8% in E1(+) compared to dd-Y. It is suggested that this hippocampal subsensitivity found in E1(+) mouse might be strain-specific, because repeated megimide convulsions failed to produce the same down regulation.

Animals↗
PubMed1983

Salivary urea nitrogen as an index to renal function: a test-strip method.

To investigate the feasibility of using salivary urea nitrogen as an index of renal glomerular filtration rate, we developed and applied a new analytical system consisting of a urease-containing test strip and an automatic reflectance spectrometer. The concentrations of urea nitrogen so determined correlate well (r = 0.93) with concentrations in serum. These preliminary data suggest that our method can be used routinely as a simple and reliable means of detecting abnormalities of renal function.

Adolescent↗
PubMed1983

The effects of diffusion and ultrafiltration on cardiac output and organ blood flows.

The effects of diffusion and ultrafiltration on cardiac output (CO) and organ blood flow (BF) in the uraemic dog were studied by a modified microsphere technique. In the diffusion phase of sequential therapy, a decrease in mean arterial pressure (MAP) and total peripheral resistance (TPR) was noted despite no change in circulatory plasma volume (CPV) and CO. In the ultrafiltration (UF) phase, MAP recovered with an increase in TPR despite the decrease in CPV and CO. Muscle vascular resistance increased in UF phase but not in the diffusion phase. The results suggest that the decrease in CPV through UF resulted in CO decrease, but that the compensation mechanism for the decrease is impaired by diffusion.

Animals↗
PubMed1982

Cysteine sulfinic acid in the central nervous system: uptake and release of cysteine sulfinic acid by a rat brain preparation.

Uptake and release of cysteine sulfinic acid by synaptosomal fractions (P2) and slices of rat cerebral cortex were investigated. The P2 fraction had a Na+-dependent high-affinity uptake system for cysteine sulfinic acid (Km, 12 microM), which was restricted to the synaptosomes. High-affinity uptake of cysteine sulfinic acid was competitively inhibited by glutamate, aspartate, and cysteic acid. None of the various centrally acting drugs tested specifically inhibited this transport system. Release of [14C]cysteine sulfinic acid from preloaded cortical slices or P2 fractions was examined by a superfusion method, which avoided reuptake of released [14C]cysteine sulfinic acid. High K+ (56 mM) and veratridine (10 microM) stimulated the release of cysteine sulfinic acid from slices and the P2 fraction in a partly Ca2+-dependent manner. Diazepam at concentrations of 10 and 100 microM markedly inhibited the stimulated release, but not the spontaneous release, by cortisol slices. On the contrary, it had no effect on the stimulated release of cysteine sulfinic acid from the P2 fraction.

Animals↗
PubMed1982

Cysteine sulfinic acid in the central nervous system: specific binding of [35S]cysteic acid to cortical synaptic membranes--an investigation of possible binding sites for cysteine sulfinic acid.

Specific binding sites for cysteine sulfinic acid, an excitatory amino acid, in crude synaptic membrane fractions of rat cerebral cortex were examined, using L-[35S]cysteic acid as a ligand. Two specific binding systems of [35S]cysteic acid were found, one Na+-dependent and the other Na+-independent. The Na+-independent specific binding of [35S]cysteic acid was saturable, with a Kd of 474 nM and Bmax of 3.29 pmol/mg protein. The binding was optimal at pH 7.4 and at 37 degrees C. Treatment of the membranes with proteases, concanavalin A, or Triton X-100 markedly reduced the binding. Of various compounds related to cysteic acid, L-cysteine sulfinic acid was the most effective competitor of this binding. These results indicate the existence of an Na+-independent specific binding site for cysteic acid in the synaptic membrane of rat cerebral cortex, which may be different from that for glutamate. Possible involvement of cysteine sulfinic acid as an endogenous ligand for this binding site is discussed.

Amino Acids, Sulfur↗
PubMed1981

Developmental alteration in RNA metabolism of E1 mouse brain.

The contents of brain RNA rose rapidly until 14 days after birth and then dropped. They were lower in the E1 than in the non-convulsive mice between 56 and 100 days of life. The contents of acid-soluble UMP and their specific radioactivities, three hours after an intracranial injection of [3 H]-orotic acid, were not different in the same age of E1 and non-convulsive mouse brains. From four to 20 days after birth, the specific and relative specific radioactivities, representing the ratio of brain RNA synthesis, of the E1 mice were lower than those of the non-convulsive strains, while the E1 mice, applying convulsions once a week, exhibited higher values during the periods from 56 to 100 days of age as compared with the non-stimulated E1 or non-convulsive strains.

Aging↗
PubMed1980

Superiority of hemofiltration to hemodialysis for treatment of chronic renal failure: comparative studies between hemofiltration and hemodialysis on dialysis disequilibrium syndrome.

A significantly lower incidence of DDS, hypotension, and impending shock was found during and after hemofiltration as compared with conventional hemodialysis. Hemofiltration, in contrast to hemodialysis, showed less decrease of circulating plasma volume, mild change in plasma osmolality without red cell swelling, better compensation of acidosis despite less uptake of acetate, more stable PCO2 during the procedure, less paradoxical acidosis in cerebrospinal fluid, and a lower urea concentration gradient between cerebrospinal fluid and plasma. These phenomena might be explained by better mass transfer between compartments bithin the body during hemofiltration. Mass transfer from the intracellular as well as the extracellular space to circulating plasma occurred more rapidly and smoothly during HF than during HD. HF is preferable to HD in patients with severe cardiovascular complications such as hypertension, as well as hypotension and cardiac failure, and in those subject to DDS during HD. Accordingly, hemofiltration therapy promises patients more comfortable and more stable treatment of chronic uremia.

Acid-Base Equilibrium↗
PubMed1979

Increase of brain taurine contents of E1 mice by physiological stimulation.

We determined the effect of physiological stimulation on taurine contents in three regions (cerebral cortex, brain stem and cerebellum) of the brain of E1 mice, a genetically epileptic strain. Taurine contents in all regions of the brain increased significantly at the onset of convulsions, as induced by tossing the animals up many times. Levels in the cerebral cortex and cerebellum increased markedly in the early stage of the stimulation, yet convulsion did not occur. Taurine contents in the cerebral cortex and brain stem returned to the resting level with 30 min after the onset of convulsions, while levels in the cerebellum remained high for 3 hr. Concentration of taurine in the plasma also increased with the onset of convulsions. On the other hand, taurine administration increased the threshold of convulsion by the stimulation in E1 mice.

Animals↗