Search PubMed⌕ Search

Biomedical subjects

Y Nakazawa

Publications and source records attributed to Y Nakazawa.

At least 109 records · Page 6Linked to original sources
PubMed1994

Improvement of cerebral blood flow and cognitive function following pacemaker implantation in patients with bradycardia.

We investigated the effects of pacemaker implantation on cerebral blood flow and cognitive function in 14 severely bradycardic patients (mean age 75.2 years). Cerebral blood flow and verbal intelligence improved after the pacemaker implantation. Systolic and mean arterial blood pressure was significantly reduced after the implantation. Changes in cerebral blood flow significantly correlated with changes in heart rate in polynomial regression analysis, but not with changes in cardiac output. Before the implantation, verbal cognitive function was lower in bradycardic patients than in age-matched control subjects, and brain CT showed significant advanced atrophy in these patients. However, verbal cognitive function was also improved after the implantation. Pacemaker implantation in the severe bradycardic elderly should be beneficial not only for cardiac function but also for brain function. We concluded that these results suggest that heart rate is one of the important factors in the regulation of cerebral circulation in patients with severe bradycardia. Pacemaker implantation in the elderly improved quality of life and may prevent mental deterioration.

Aged↗
PubMed1994

[Effects of mianserin hydrochloride on delirium: comparison with the effects of oxypertine and haloperidol].

Mianserin (10-60 mg), haloperidol (2-6 mg) and oxypertine (20-60 mg) were administered once before bedtime in patients with delirium in Kurume University Hospital. The therapeutic effects of these drugs were investigated in the pre- and post-treatment using Delirium Rating Scale (DRS: Trzepacz et al., 1988). Mianserin was observed to be effective on 67% of the cases, and haloperidol and oxypertine in about 60%. Based on the clinical results and on the measurement of plasma concentration of mianserin, mianserin was considered to be an effective drug particularly against delirium in elderly patients because the effect and plasma concentration of mianserin were observed in the early stage of treatment without any side effects. The reduction of plasma free-MHPG was accompanied with improvement in the delirious state. The reason for the changes in plasma free-HVA was unclear.

Adult↗
PubMed1994

[Autosomal recessive hereditary cortical cerebellar atrophy with striatal degeneration--two siblings showing choreoathetoid movement, ataxia, dementia, and amenorrhea].

We present two siblings with hereditary cortical cerebellar atrophy (CCA), who showed peculiar clinical features. Their unaffected parents are cousins. The mode of inheritance in this family was autosomal recessive. Both patients developed involuntary movement and ataxia during the fourth decade. The proband (patient 1) was the elder sister. She developed choreoathetoid involuntary movement and cerebellar ataxia at the age of 32. At the age of 39, she showed mental deterioration and marked gait disturbance due to severe ataxia and amyotrophy. At the age of 40, she took medication for hypertension. At the age of 42, she was bedridden and had generalized convulsions and dysautonomia. Involuntary movement continued until her death at age 44. She had amenorrhea since the age of 25 years. Neuropathological findings. The brain weighed 1,010 g. We found marked degeneration in the cerebellar cortex including the molecular, Purkinje cells, and granular cell layers, and in the inferior olivary nuclei. In the basal ganglia, the putamen and caudate nuclei were moderately affected, but the substantia nigra and globus pallidus were spared. The cerebral cortex was spared, but the cerebral white matter showed diffuse myelin pallor without fibrillary gliosis. In the pons, the volume of the tegmentum was moderately decreased, but the base was spared. The spinal cord was normal. The findings of the patient differed from those of the case originally reported by Gordon Holmes in 1907. Holmes autopsied a case showing severe degeneration in both the cerebellar cortex including all three layers and the inferior olivary nucleus as in our patient. However, the striatum of his case spared and the patient did not develop involuntary movement as did other patients. The patients presented here should be distinguished from Holmes' original case clinicopathologically.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Histo-pathological study of a glass-ionomer/resin (Geristore) restoration system.

The purpose of this experiment was to investigate histo-pathologically the pulpal reaction to a glass-ionomer/resin (Geristore) restoration system in human teeth. Black's class I cavities were prepared in 22 human teeth; these were divided into 2 groups, one with the Geristore after cavity was cleaned with 10% NaOCl solution and 3% H2O2 solution (Group G) and the other with the Geristore after the cavity was applied with Mirage-Bond (Group MG). The treated teeth were observed clinically over 90 days after operation. They were then extracted for histological examination. No unpleasant symptoms were noted. A few pathological changes were observed. No histo-pathological score differences were observed between groups G and MG. The average evaluation score of pathological results in both groups G and MG were excellent. Microorganisms observed in the cavity dentin of the group G was fewer than in group MG. In some cases, microorganisms were observed along the dentin walls. In conclusion, the pulpal injury due to this Geristore restoration system was slight, and the system was considered to be safe for the pulp and clinically useful.

Adult↗
PubMed1993

Induction of metallothionein by CdCl2 administration in rat prostate.

Metallothionein (MT) induction in the rat prostate gland was investigated by means of cadmium chloride administration. Ten-week-old male Wistar rats housed with cadmium free food were divided into three groups of six rats each and castrated. After seven days, 1 mg of testosterone propionate per rat was injected subcutaneously once a day until the end of the experiment. After three weeks, rats were injected daily for six days with a physiological saline, 0.3 mg/kg CdCl2, and 0.9 mg/kg CdCl2. MT concentration of the ventral and dorsal lobes was significantly increased in the three groups in proportion to the dose of CdCl2. MT content of the lateral lobe in three groups was also increased, but was not significantly different. Immunohistochemically, MT was induced mainly in the ventral lobe in the basal cells, and in the lateral and dorsal lobes in the epithelial cells. The weights of the prostatic lobes were similar in the three groups, and no histological change was identified. These results suggested that MT in the prostate was induced by cadmium administration, and that it may prevent cellular damage from harmful metals.

Animals↗
PubMed1993

CDPcholine:1,2-diacylglycerol cholinephosphotransferase from rat liver microsomes. I. Solubilization and characterization of the partially purified enzyme and the possible existence of an endogenous inhibitor.

The solubilization and partial purification of cholinephosphotransferase (CDPcholine:1,2-diacylglycerol cholinephosphotransferase, EC 2.7.8.2) from rat liver microsomes were examined in the presence of ionic (sodium deoxycholate), nonionic (Triton X-100, n-octylglycoside), or zwitter ionic (CHAPS) detergents. Among the four detergents tested, only sodium deoxycholate was found to be an efficient solubilizer of cholinephosphotransferase activity from microsomal membranes, whereas the other three detergents caused irreversible inactivation of the enzyme at the solubilization step. Addition of phospholipids at the solubilization step, or after solubilization of the membrane proteins, could not preserve or reconstitute activity to any extent. The sodium deoxycholate-solubilized activity was partially purified by gel permeation chromatography (Superose 12HR). The partially purified preparation appeared to consist of a large aggregate containing phospholipids; further dissociation of the protein-phospholipid complex caused complete inactivation of the enzyme. The partially purified cholinephosphotransferase showed a specific activity of 100-130 nmol/min/mg protein, which is the highest activity reported to date from any tissue source; this amounts to a 4-fold enrichment of cholinephosphotransferase activity from the original KCl-washed rat liver microsomes. Ethanolaminephosphotransferase (CDPethanolamine:1,2-diacylglycerol ethanolaminephosphotransferase, EC 2.7.8.1) activity was copurified and 6-fold enriched with a total recovery of 60%. During the purification of cholinephosphotransferase activity, a putative endogenous inhibitor of cholinephosphotransferase was also solubilized and was isolated from the microsomal membranes. This heat-labile, nondialyzable inhibitor was shown to act specifically on cholinephosphotransferase and not on ethanolaminephosphotransferase. Further characterization of the inhibitory activity revealed that it may act at the binding step of the cholinephosphotransferase to its lipid substrate, diacylglycerol.

Animals↗
PubMed1993

Major histocompatibility antigen-restricted cytotoxicity in inflammatory bowel disease.

BACKGROUND: The role of cytotoxicity mediated by peripheral blood mononuclear cells for colonic epithelial cells in inflammatory bowel disease (IBD) is still controversial. To clarify it, we studied major histocompatibility antigen (MHC)-restricted T cell-mediated cytotoxicity (CTL). METHODS: Cytotoxicity was measured by 51Cr release from colonic cells after the 6-hour incubation with peripheral blood mononuclear cells in 11 IBD patients (6 with Crohn's disease and 5 with ulcerative colitis). RESULTS: CTL activity (E/T ratio = 200:1 or 100:1) for autologous target cells was significantly increased (22%-40%) in 5 of 6 CD and 4 of 5 UC patients (22%-64%) compared with that for allogeneic target cells. The increase in CTL activity was mainly inhibited by anti-MHC class I and CD8 monoclonal antibodies (50 micrograms/mL), while it was partially inhibited by anti-MHC class II or CD4 antibodies in some patients. Complement-mediated depletion of CD2+ cells also significantly decreased CTL activity. CONCLUSIONS: The results indicate that MHC-restricted T cell cytotoxicity may play a role in mucosal damage in some patients of IBD.

Adolescent↗
PubMed1993

Effects of indeloxazine HCl on kindled amygdaloid seizures in rats: comparison with the effects of phenytoin, diazepam, ethanol, and imipramine.

The anticonvulsant effect of [(+/-)-2-[(inden-7-yloxy)methyl]morpholine (indeloxazine) HCl, a new cerebral activator, was investigated in rats against kindled seizures from the amygdala, an assumed model of secondarily generalized seizures in human. Indeloxazine (0.25-10 mg/kg, IP) dose-dependently depressed the kindled seizure and shortened the evoked amygdaloid afterdischarge. A high dose of indeloxazine (40 mg/kg, IP), however, induced generalized seizures. Comparison of the effects on the kindled seizures of indeloxazine to those of phenytoin, diazepam, ethanol, and imipramine revealed that the anticonvulsant actions of indeloxazine are similar to those of imipramine but not to those of phenytoin, ethanol, and diazepam. The results suggest that indeloxazine may exert its action through the monoaminergic system in the brain.

Animals↗
PubMed1993

Effects of zopiclone on slow wave sleep and spontaneous K-complexes for normal healthy young adults.

Benzodiazepine (BZD) hypnotics have been known to decrease, to some degree, human slow wave sleep (SWS) although they elevate the arousal threshold during sleep. Zopiclone (ZPC), a cyclopyrrolone hypnotic, has attracted the interest of sleep researchers because an increase in human SWS has been reported. Since the increase has not been fully confirmed by all of the studies, the authors investigated the effects of ZPC 10 mg on SWS and the K-complexes for 7 healthy young adults because there is evidence indicating that delta waves consisting of SWS and the spontaneous K-complexes are identical. SWS and st. 4 sleep did not decrease on any of the ZPC nights but st. 3 sleep showed a tendency to reduce on the 1st ZPC night. The frequency of the K-complexes decreased significantly on the 2nd ZPC night and tended to reduce on the 1st ZPC night. Moreover, a significant positive correlation was noted between the decrease rates of SWS and the K-complexes on both the ZPC nights. The authors, therefore, could not obtain any findings suggesting an increase in SWS with ZPC.

Administration, Oral↗
PubMed1993

[Treatment of severe pneumonia due to methicillin-resistant Staphylococcus aureus (MRSA) and Candida krusei with granulocyte colony-stimulating factor (G-CSF): a case report].

A 24-year-old male with chronic renal failure on Continuous Ambulatory Peritoneal Dialysis (CAPD) complained of cough and dyspnea. Chest X-ray film showed a pneumonia shadow and MRSA and Candida krusei were detected in the sputum. Pneumonia improved with vancomycin and fluconazole. Treatment with methylprednisolone was needed for retinodialysis. After this treatment, pneumonia deteriorated. Pneumonia did not improve with vancomycin and anti-fungal agents. This severe pneumonia was improved with a combination therapy of vancomycin, miconazole and G-CSF. A combination therapy of antibiotics and G-CSF is considered to be effective for severe pneumonia.

Adult↗
PubMed1993

Study of pulpal response to an adhesive composite resin restoration using A NPG primer and a PMDM monomer (Mirage-Bond).

The purpose of this experiment was to investigate histo-pathologically and clinico-pathologically the pulpal reaction to a composite resin restoration system with a NPG primer and an adhesive bonding agent containing a carboxylate adhesive monomer, PMDM, using beagle dog and human teeth. The contact area between the composite resin with the primer and the monomer and the dentin cavity wall was observed through the SEM imaging. In the histo-pathological study, the average evaluation score of pathological results in group M (the composite resin restoration using the NPG primer and the bonding agent containing PMDM monomer "Mirage-Bond") was superior and almost the same as in group P as a contrast group (the composite resin restoration using a bonding agent "Clearfil Photo Bond" after enamel and dentin wall etching with 40% phosphoric acid). The dispersion of pathological results by score in group M was much narrower than in group P. Microorganism growth in group M was less than that of group P. Gap spaces caused by coming off in the region of contact area between the filled resin and the dentin cavity wall were observed through the SEM imaging. The number of cases coming off in group M were fewer than in group P. Gap spaces in group M were narrower in width than in group P. In the SEM imaging, microorganisms were observed in most cases with gap areas. In the clinico-pathological study on restoration with "Mirage-Bond", unpleasant sings symptoms had not occurred except in a few cases. The pathological result by score was comparatively superior. The pathological results of human teeth were similar to the pathological results of dog teeth. The pulpal irritation due to this composite resin restoration system with the NPG primer and the PMDM monomer containing adhesive bonding agents was generally minor, and the system was considered to be safe and useful even though the contraction gap spaces were found in some cases.

Adolescent↗
PubMed1992

CDP-choline: 1,2-diacylglycerol cholinephosphotransferase from rat liver microsomes. II. Photoaffinity labeling by radioactive CDP-choline analogs.

Photoaffinity labeling of cholinephosphotransferase from rat liver microsomes directly by its substrate, [32P]CDP-choline or by a synthetic photoreactive CDP-choline analog, 3'(2')-O-(4-benzoyl)benzoyl [32P]CDP-choline (BB-[32P]CDP-choline), was examined for the possible identification of its molecular form on subsequent SDS-PAGE followed by 32P-autoradiography. When the partially purified cholinephosphotransferase was photoirradiated in the presence of [32P]CDP-choline, a considerable amount of 32P-radioactivity was incorporated into the TCA-insoluble component. This incorporation was dependent on irradiation time, Mg2+ or Mn(2+)-requiring and inhibited strongly by the presence of Ca2+. Either CDP-choline or CDP-ethanolamine inhibited the ultraviolet irradiation-dependent incorporation of 32P-radioactivity into the TCA-insoluble component in a dose-dependent manner, whereas neither phosphocholine or 5'-CDP had any effect on this process. These results strongly suggested that the observed 32P-incorporation from [32P]CDP-choline into the protein component could be a consequence of the covalent interaction between cholinephosphotransferase and its substrate, [32P]CDP-choline. Two polypeptides, 25 kDa and 18 kDa, with high 32P-radioactivity were clearly identified on a SDS gel after the direct photoaffinity labeling with [32P]CDP-choline for more than 5 min of ultraviolet irradiation. On the other hand, when BB-[32P]CDP-choline was used as a photoaffinity ligand, a single polypeptide with apparent molecular size of 55 kDa could be rapidly photolabeled within 2.5 min, then this band gradually lost its 32P-radioactivity with increasing time of ultraviolet irradiation. Thus, the overall results strongly indicated that cholinephosphotransferase in rat liver microsomes exists most likely as a 55 kDa polypeptide (or subunit) and that 25 kDa and 18 kDa peptides identified after the direct photoaffinity labeling with [32P]CDP-choline were probably the photo-cleavage products of cholinephosphotransferase during the prolonged ultraviolet irradiation, both of which could contain the catalytic domain of the original enzyme protein(s).

Animals↗