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Biomedical subjects

N Yamaguchi

Publications and source records attributed to N Yamaguchi.

At least 739 records · Page 41Linked to original sources
PubMed1986

A pharmacokinetic study of clomipramine in regions of the brain.

The pharmacokinetic profiles of clomipramine (CMP) and the serial changes of its concentration in specific brain regions were investigated in rats after an acute treatment with intravenous CMP (10 mg/kg). The CMP concentrations in plasma declined triexponentially and fitted a three-compartment open model. The brain to plasma concentration ratio showed a constant value, 22.2 +/- 4.9, 30 minutes after the injection. Regional brain differences in the CMP distribution and accumulation were also found. Four hours after the injections, the hippocampus was found to have the highest drug concentration, and the concentrations in this region were in the following order; thalamus, striatum, amygdala, cortex greater than pons + medulla oblongata greater than hypothalamus, bulbus olfactorius + septum, mesencephalon greater than cerebellum. Particularly, unique kinetics were observed in the cortex, amygdala and hippocampus.

Animals↗
PubMed1986

The effect of maternal antigenic stimulation upon the active immune responsiveness of their offspring: suppression induced by soluble protein antigen, ovalbumin, in mice.

The active immune responsiveness of the offspring of pregnant mice stimulated with heterologous protein antigen was investigated by measuring the plaque-forming cells (PFC). Mice (C57BL/10;B10) immunized once in pregnancy with ovalbumin (OVA) in the form of Al(OH)3 gel (in alum) or in a soluble form (in saline) developed no anti-OVA PFC response. The anti-OVA PFC response suppression induced in the offspring was high in the offspring of alum-treated mothers and low in those of saline-treated mothers. The optimal dose of OVA in alum that induces the highest immunological memory in pregnant mice caused the complete suppression of PFC development in their offspring. The same dose of OVA in saline induced a negative immunological memory in pregnant mice and partial suppression in the offspring. On the other hand, mice primed prior to conception and boosted during pregnancy developed anti-OVA PFC in significant numbers, and only a partial suppression was established in their young. Based on these data, we discussed the possible mechanisms concerned with the specific suppression induced in the young B10 mice stimulated by OVA.

Animals↗
PubMed1986

Presynaptic inhibitory effects of sotalol, propranolol, and acebutolol on noradrenaline release upon cardiac sympathetic nerve stimulation in anesthetized dogs.

Effect of sotalol (STL) was compared with that of (+/-)-propranolol, (+)-propranolol (PPL), and acebutolol (ABL) on noradrenaline (NA) release as measured in coronary sinus (CS) blood during postganglionic stimulation (2 Hz, 30 s) of the left cardiac sympathetic nerves in anesthetized dogs. In control dogs receiving saline, increasing responses of CS-NA concentration, mean CS blood flow, and CS-NA output to repetitive stimulation were relatively stable throughout a given experimental period. Both STL (1,2.5, and 5 mg/kg, i.v.) and (+/-)-PPL (0.5 and 2.5 mg/kg, i.v.) diminished the increased CS-NA concentration by approximately 35 (P less than 0.05) to 60% (P less than 0.01) in a dose-dependent fashion. However, (+)-PPL (0.02-2.5 mg/kg, i.v.) and ABL (0.5-5 mg/kg, i.v.) did not significantly alter the increasing response of CS-NA concentration upon stimulation. STL, (+/-)-PPL, and ABL markedly inhibited the CS blood flow response to stimulation at all doses tested, while (+)-PPL did not significantly diminish the flow response even at the highest dose tested. Consequently, CS-NA output decreased significantly (p less than 0.01) in the presence of STL, (+/-)-PPL, and ABL at all doses tested but not with (+)-PPL at any dose tested. The inhibitory effect of STL and (+/-)-PPL on the increasing response of CS-NA concentration upon stimulation could be related to their beta-blocking effect, which exerts presumably on postulated presynaptic beta-adrenoceptors, as (+)-PPL did not at all diminish the response.(ABSTRACT TRUNCATED AT 250 WORDS)

Acebutolol↗
PubMed1986

Effects of cytochrome b5 on aniline hydroxylation catalyzed by a reconstituted system containing acetone or 2,2'-bipyridine.

Cytochrome b5 did not exert any effect on NADPH-dependent aniline hydroxylation in the absence of acetone or 2,2'-bipyridine, whereas cytochrome b5 exhibited a stimulatory effect on the reaction in the presence of acetone or 2,2'-bipyridine. In addition, cytochrome b5 did not have any significant effect on the cumene hydroperoxide-dependent reaction in the presence of acetone or 2,2'-bipyridine.

2,2'-Dipyridyl↗
PubMed1986

New bioptic method for submucosal tumor of the gastrointestinal tract.

Biopsy for the submucosal tumor has not been established and it is extremely rare that tumor tissues are obtained by usual biopsy forceps except in cases showing ulceration. Moreover, tumor tissues from the ulcerated site often showed degeneration or necrosis, and are difficult for pathohistological diagnosis. In addition, the biopsies are often associated with bleeding. We have developed a new biopsy method. Briefly, a small amount of pure ethanol is injected topically into the surface of submucosal tumor to produce a small ulcer for biopsy, and several days later a biopsy specimen is obtained from the exposed tumor at the ulcer bottom. We performed this method for 12 lesions in 12 cases. In 64 of 100 bioptic specimens, tumor tissue was obtained and in all cases pathohistological diagnosis could be established. We believe this method will be important to determine the indication of endoscopic treatment or surgical operation, and for follow up observation.

Adult↗
PubMed1986

[Scintigraphic imaging of autotransplanted splenic grafts by 99mTc-labeled heat-damaged erythrocytes].

Splenectomy is known to increase the risk of bacterial infection. Recently splenic autotransplantation has been suggested as a method of preserving splenic function. In order to demonstrate the viability of transplanted tissue, spleen scintigraphy using 99mTc labeled heat damaged erythrocytes were carried out. So far 21 studies have done in 12 patients. Spleen scans were positive 1 month after surgery, though images showed poor contrast against considerable background of bone marrow and blood pool. The quality of the images much improved five to twelve months after surgery. Functioning splenic autografts could be also shown by scintigraphy using 99mTc sulfur colloid, but the image quality was poorer, particularly within the early stage after operation. Labeling yields were 79.8% on the average, ranging from 45.6-92.3%, that affected little the quality of images. Important techniques in the splenic autotransplantation imaging include a thorough elimination of free 99mTcO4- before injection and to use comparatively small volume of damaged erythrocytes.

Adolescent↗
PubMed1986

An electroencephalographic study of psychiatric inpatients with antipsychotic-induced tardive dyskinesia.

The awake EEGs of 48 psychiatric inpatients with tardive dyskinesia were compared with those of 29 matched controls without TD. EEGs of the TD patients were as follows: 22 (45.8%) were normal EEGs; 17 (35.4%), mildly abnormal EEGs; 8 (16.7%), moderately to severely abnormal EEGs. One record was excluded for severe artifacts. The control group showed a similar incidence of EEg abnormalities. EEGs with poor occipital alpha rhythm were significantly more frequent in the TD group than the control group. The TD patients tended to have an alpha rhythm of low voltage. Other characteristics of the alpha rhythm and amounts of theta, delta and beta activity showed no significant differences between the two groups. Severity of TD had no significant influence on EEG findings. The EEG similarities of TD and Huntington's chorea were discussed, and a suggestion was made that not only the basal ganglion, but also the cerebral cortex, could be involved in development of TD.

Adult↗
PubMed1986

[Adult T cell leukemia accompanied by marked swelling of the left thigh].

A patient with adult T cell leukemia (ATL) whose chief complaint was marked swelling of left thigh is reported. A 72-year-old woman was diagnosed as having ATL based on a high titer of anti-ATLA antibody and abnormal lymphocytes with convoluted nuclei. Computed tomography revealed swelling of her left thigh and a large low-attenuation mass in its muscles. Aspirate from her thigh contained many abnormal cells. Though chemotherapy reduced the swelling for two weeks, she had a relapse and died. This is the first case of ATL having such an onset reported in Japan.

Aged↗
PubMed1986

Acid protease secreted from human pancreatic carcinoma cell line HPC-YT into serum-free, chemically defined medium.

Active acid protease was found in serum-free spent medium of human pancreatic carcinoma cell line HPC-YT. These cells have been maintained for over 215 generations in a serum-free, chemically defined medium. Acid protease was partially purified about 3000-fold by Mono Q ion-exchange chromatography, pepstatin-aminohexyl-Sepharose affinity chromatography, hydroxylapatite affinity chromatography, lectin affinity chromatographies, and gel filtration on TSK G3000SW. The molecular weight of the purified enzyme was estimated to be 63,000. An acid protease isolated from normal pancreas has two forms with molecular weights of 11,000 and 32,000. Isoelectric focusing of acid protease derived from HPC-YT revealed five isotypes, whereas the enzyme from normal pancreas showed only three bands. The optimal pH using bovine hemoglobin as substrate was 3.0 for both the normal and the HPC-YT-derived acid proteases. The HPC-YT enzyme was more heat stable than the enzymes of normal pancreas. Sulfhydryl compounds and metal ions had no apparent effects on this enzyme; however, pepstatin strongly inhibited it. We suggest that acid protease secreted from cancer cells may play a role in the destruction of the surrounding tissue matrix.

Adenocarcinoma↗