Search PubMed⌕ Search

Biomedical subjects

M Nakaya

Publications and source records attributed to M Nakaya.

At least 91 records · Page 5Linked to original sources
PubMed1992

Fast skeletal myosin isoforms in thermally acclimated carp.

Fast skeletal myosins were isolated from carp acclimated to 10 and 30 degrees C, and their structural and enzymatic properties were compared. Myosins in 0.5 M KCl were subjected to limited proteolysis by using various proteases including alpha-chymotrypsin, trypsin, and papain, and different SDS-PAGE patterns were seen for the 10- and 30 degrees C-acclimated myosins in all cases. Myosin subfragment-1 (S1) prepared from the 10 degrees C-acclimated myosin by alpha-chymotryptic digestion in 0.12 M NaCl showed higher acto-S1 Mg(2+)-ATPase activity and lower thermostability than S1 from the warm-acclimated myosin. The peptide maps and ATP-induced spectral changes of tryptophan fluorescence also showed an obvious difference between the two types of S1. Temperature acclimation further caused changes in the rod region of myosin, since the apparent sizes of light meromyosin were different from each other for the two types of myosin. Myosin from carp acclimated to 20 degrees C showed intermediate properties between those of the 10- and 30 degrees C-acclimated myosins. Myosin isoforms might be expressed in a temperature-dependent manner to compensate for the effect of seasonal environmental temperature variation on swimming ability.

Acclimatization↗
PubMed1992

[A case report of spinal epidural hematoma complicated after open heart surgery].

The authors reported the first case of acute spinal epidural hematoma (SEH) developed after open heart surgery. The patient was noticed that her legs felt weak and numb on the first postoperative day evening. On the next day morning, neurological examination revealed that flaccid paralysis of both legs and also loss of all sensory perception below the level of Th-6 spine bilaterally. The prolonged effect of anesthesia and painless onset made delayed recognition of the lesion. SEH (Th5-7) was diagnosed with MRI and decompressive surgery was immediately done, sixty hours after the beginning of cardiac operation. But in this case neurological deficits were not changed. We concluded that a routine diagnostic approach was very important procedure to find out this serious complication for all patients underwent open heart surgery in early period of its onset.

Cardiac Surgical Procedures↗
PubMed1992

[Mitral valve surgery for patients after undergoing percutaneous transvenous mitral commissurotomy (PTMC)--investigation on indication of PTMC based on the intraoperative findings].

Ten patients underwent open heart surgery for mitral valve after PTMC because of post PTMC MS (n = 4) and MR (n = 6) out of 150 patients undergoing PTMC in our hospital between June 1987 and October 1991. Intraoperative findings of 4 patients with residual mitral stenosis included severe thickening, stiffening and calcification on anterior and posterior leaflets, commissures and subvalvular apparatus. Mitral valve repair was possible in 2 and mitral valve replacement (MVR) was necessary in the other 2. In all 6 cases who massive mitral regurgitation after PTMC, in repairable tears in the mitral leaflets necessitated MVR. Since in these cases changes in the leaflets were less severe than those of the commissures or subvalvular apparatus, surgical repair could have been possible if open mitral commissurotomy (OMC) was done primarily. Patients selection for PTMC versus OMC based on precise morphological evaluation of mitral valve would reduce occurrence of massive MR resulting in surgical replacement.

Adult↗
PubMed1991

[Long-term follow-up results on Bentall's and our modified procedure].

Replacement of the ascending aorta and the aortic valve with composite graft, including reimplantation of coronary ostia, were performed in 84 patients from October, 1978 to December, 1989. Annuloaortic ectasia was the most common indication for surgery (76 patients). Thirty patients (36%) had the Marfan syndrome. Thirty-five patients were performed with original Bentall's procedure. Thirty patients were carried out with our modified technique like Inberg's, the coronary arteries were excised with attachment of the selected piece of the aortic wall, and implanted to the tube prosthesis with continuous suture. Nineteen patients were operated with modified technique by Cabrol or other interposition graft method. The actuarial free of death related to the operation of 4 years was 83%, 88%, and 74% (p = NS) in each methods respectively. The complications of anastomosis, for example, leakage and dilatation of coronary ostia were not seen in our modified Bentall's procedure. In conclusion, our modified method is proved to be reliable and competent.

Adult↗
PubMed1990

A case of schizophrenia with the multiplication of other persons--the destruction of ambiguity.

We present a case of schizophrenia with the multiplication of other persons. The delusion in our case may be considered as that of Capgras syndrome but the former is different from the latter in some ways. In the delusion of our case, there occurred the disintegration of mind and body. We considered this disintegration in relation to schizophrenic destruction. We recognize the destruction of ambiguity in schizophrenia. That is, two dimensions that construct ambiguity are broken up and become independent from each other. In the delusion of our case, the ambiguity in the living body was destroyed. This destruction seems to be based on the schizophrenic though disorder: the cohesion of the concrete and overabstract.

Attention↗
PubMed1990

Disturbance of self-evidence and delusion.

Psychopathologically we study the process from the disturbance of self-evidence to the formation of delusions. When delusions arise on the basis of the disturbance of self-evidence, this disturbance impairs the way of judgment. We present a case of schizophrenia in which the unlimited questions about grounds make it impossible for the patient to establish the self-evident as itself and to judge inductively. The formation of delusions is the psychopathological extrication from the impairment of the inductive judgment. In the formation of delusions on the basis of the disturbance of self-evidence, we can observe the process from the weakening to the substantiation toward the outside of the transcendental organization.

Adult↗
PubMed1990

Sex differences in blood constituents of rats following tail suspension.

Tail suspension was utilized to study sex differences in the effects of hypokinesia on blood constituents of rats. Twelve male and twelve female rats were used. After four weeks of exposure to tail suspension or non-treatment, the rats were laparotomized under ether anesthesia and blood samples were obtained. Biochemical tests on the blood samples were then performed immediately. Hematocrit and serum iron were also estimated. The results were as follows: 1) The same tendencies were noted in blood constituents between male and female rats in the control group and the tail suspension group. 2) The average levels of blood albumin, creatinine, uric acid, glucose, triglyceride, serum iron and hemoglobin in the tail suspension group were lower than those in the control group, especially in male rats.

Animals↗
PubMed1989

Monoclonal antibody raised against tetrodonic acid, a derivative of tetrodotoxin.

Tetrodonic acid, a relatively non-toxic derivative of tetrodotoxin, was conjugated with bovine serum albumin and injected i.p. to BALB/c mice. After several injections, spleen cells were isolated, fused with myeloma cells X63-Ag8-6.5.3. and cloned by the limiting dilution method. The monoclonal antibody produced in ascites fluid in the mouse by the cloned cell showed an increasing reactivity with tetrodotoxin at concentrations ranging from 0.03 to 100 micrograms per well.

Animals↗
PubMed1988

Species differences in inhibitory effect of Li+ on high K+-induced contraction in the ileal longitudinal smooth muscle.

The effects of Li+ substitution for external Na+ in the medium on a 60 mN KCl (60K+)-induced contraction were compared in the ileal longitudinal smooth muscles isolated from monkey, rabbit, guinea pig and rat. Li+ substitution inhibited the 60K+-induced contraction in the ileum of all the animal species. Greater inhibitory effect was observed with the increase in external Li+ concentration and the increase in incubation period with Li+. Intracellular Li+ contents of these muscles also increased with the increase in external Li+ concentration and the incubation period. Thus, a good correlation was obtained between Li+-induced inhibition of 60K+-induced contraction and the increase in Li+ content. However, close examination revealed that the contraction in monkey and rat ileum was inhibited by much lower Li+ accumulation than that in guinea pig and rabbit ileum, suggesting the existence of species difference in the sensitivity of the ileal smooth muscle to the inhibitory effect of Li+ substitution, and a mechanism for the species differences in the inhibitory action of Li+-substitution was discussed.

Animals↗
PubMed1987

Distribution of tritiated tetrodotoxin administered intraperitoneally to pufferfish.

Tetrodotoxin was recoil-tritiated by the 3He(n,p)3H reaction and purified by gel filtration. The [3H]tetrodotoxin gave only one spot in both cellulose acetate strip electrophoresis and thin layer chromatography. The specific toxicity of tetrodotoxin did not decrease during the recoil tritiation and the [3H]tetrodotoxin showed a specific radioactivity of 25 x 10(-6) Ci/mmole. In spite of the low specific radioactivity, the [3H]tetrodotoxin was able to be used to investigate the anatomical distribution of tetrodotoxin in pufferfish. When intraperitoneally injected into 'torafugu' puffer, [3H]tetrodotoxin accumulated in most tissues, the level being highest in the skin, followed by the liver, intestines and muscle. With time, the [3H]tetrodotoxin radioactivity level in the injected pufferfish decreased in most tissues, except for skin and gallbladder. Based on these results, the metabolism of tetrodotoxin in pufferfish is discussed.

Animals↗
PubMed1986

[Experimental study on carbohydrate metabolism and pancreatic endocrine function after pancreatectomy--influence of islet activating protein (IAP)].

The influences of IAP on the residual pancreatic endocrine function and carbohydrate metabolism after extensive pancreatectomy in the rat were studied with oral glucose tolerance test (OGTT), arginine tolerance test (ATT), and measurement of hepatic glycogen, and hepatic glycolytic enzyme activity, and histological examination, etc. Wistar male rats weighing around 300 g were divided into the groups with IAP treatment and without it, and in the group with IAP treatment IAP 10 micrograms/kg was administered without anesthesia via the tail vein. In each group 60 and 90% pancreatectomies were performed in accordance with Scow's method, and the simple laparotomy group was used as control. Slight abnormality of glucose tolerance was shown in 60% pancreatectomy. The abnormality became worse with time in 90% pancreatectomy. Glucagon secretion was not damaged markedly even after extensive pancreatectomy. IAP stimulated IRI secretory response and improved glucose tolerance in 60% pancreatectomy group. IAP showed no effect in 90% pancreatectomy group. IAP did not stimulate IRG secretory response after pancreatectomy. Hepatic glycolytic enzyme activity was high in the group with IAP treatment. From the above observation, it has been suggested that IAP may be indicated for the abnormal carbohydrate metabolism after pancreatectomy, if pancreatectomy is not too extensive.

Animals↗
PubMed1985

Structure-activity relation among macrolide antibiotics in initiation of interdigestive migrating contractions in the canine gastrointestinal tract.

The relation between the chemical structure of commercially available macrolide antibiotics and their activity in inducing interdigestive migrating contractions (IMC) was studied in conscious dogs. It was found that the 14-membered macrolides erythromycin and oleandomycin are active in inducing IMC in the stomach in association with the endogenous release of motilin. These erythromycin- and oleandomycin-induced contractions in the stomach migrated through the small intestine in a caudad direction. Conversely, 16-membered macrolide antibiotics such as leucomycin, acetylspiramycin, and tylosin do not induce any contractions in the stomach or stimulate endogenous release of motilin. These findings suggest that the IMC-inducing activity in macrolides seems to be closely related to their chemical configuration, i.e., the structure of 14-membered macrolides with dimethylaminosugar (desosamine) bound at C-5 and neutralsugar at C-3 in glycosidic linkage in parallel is likely to be necessary for IMC-inducing activity. The mechanisms by which erythromycin and oleandomycin stimulate endogenous motilin release are not known.

Animals↗