Biomedical subjects

H Hirata

Publications and source records attributed to H Hirata.

341 records · Page 19Linked to original sources

PubMedDate not supplied

Effects of chronic codergocrine mesylate administration on the brain somatostatinergic system in aged rats.

Codergocrine mesylate (dihydroergotoxine; DHET), which is an ergot derivative, has been reported to counteract some age-induced impairments in brain function, but the mechanism of these effects is not known. We examined the effect of chronic DHET administration on the somatostatinergic system in the brains of aged rats. Intraperitoneal injections of DHET (1 mg/kg per day) or of vehicle were given to aged rats for 14 days, and resulted in a significant increase in somatostatin (SOM) receptor binding in all six brain regions examined except the hindbrain. DHET had no effect on SOM receptor binding in the brains of young-adult rats. However, the SOM concentration in aged rats was nearly identical to that in young-adult rats and the SOM concentration in different brain areas did not change after chronic administration of DHET. Thus, the present results suggest that chronic administration of DHET can ameliorate at least one of the age-induced impairments of brain somatostatinergic function.

Journal Article↗

PubMedDate not supplied

Cholinergic deficits in aged rat brain are corrected with nicergoline.

Choline acetyltransferase (CAT) and muscarinic cholinergic receptor (MCR) activities are markedly reduced in aged as compared with young-adult rat brain. Nicergoline was found to correct these reduced activities in most regions of the brain, especially in the cerebral cortex and hippocampus. Chronic administration of nicergoline had no effect on CAT activity or MCR binding in young-adult rat brain. Nicergoline thus appears to have a specific therapeutic effect on cholinergic functions in aged rat brain, where it acts both pre-synaptically and post-synaptically.

Journal Article↗

PubMedDate not supplied

Effects of repeated administration of rolipram, a cAMP-specific phosphodiesterase inhibitor, on acetylcholinergic indices in the aged rat brain.

The effects of repeated treatment of rolipram, a cAMP specific phosphodiesterase inhibitor (0.1 mg/kg/day i.p., 14 days), on several neuronal cholinergic indices, especially on those in aged rats were examined. In young-adult rats, rolipram treatment increased choline acetyltransferase (ChAT) activity (V(max)value) in the striatum as well as in thalamus + midbrain, whereas it decreased choline esterase activity in the hippocampus. The ChAT activity (V(max)value) and the M1-R binding (B(max)value) in the aged control rats were significantly reduced in all the brain regions examined, compared with the young-adult rats, but consecutive rolipram treatment ameliorated the reductions of both indices in the frontal cortex and the hippocampus to approximately the young-adult control levels. Since high membrane binding site concentrations for rolipram itself were revealed in the frontal cortex and the hippocampus, where the rolipram treatment showed ameliorating effects on the ChAT activity and the M1-R binding, the present findings indicate that repeated rolipram administration easily affects these two brain regions. Thus, repeated rolipram administration could restore both the presynaptic ChAT activity and the postsynaptic muscarinic cholinergic M1-R binding which are decreased with aging.

Journal Article↗

PubMedDate not supplied

Ultrasonography and magnetic resonance imaging in Leigh disease.

An infant with Leigh disease, who was the younger sister of a similarly affected infant, had been examined before the onset of the disease. Ultrasonography revealed hyperechoic lesions in the putamen and caudate nucleus during the preclinical stage. At onset, these changes extended into the cerebral cortex and medulla. These lesions were also detected by T2-weighted magnetic resonance imaging (MRI) as areas of increased signal intensity. Her brother demonstrated the same ultrasonographic results; cranial computed tomography disclosed low-density areas in the basal ganglia which were detected as hyperechoic lesions by ultrasonography. These findings suggest that ultrasonography is useful in detecting early intracranial lesions in Leigh disease.

Basal Ganglia↗

PubMedDate not supplied

Double-ring and double-layer sign of the anterior lens capsule during cataract surgery.

BACKGROUND: Splitting of the lens capsule with a double-ring contour during continuous curvilinear capsulorrhexis has not often been reported. CASE: An 86-year-old woman underwent phacoemulsification cataract extraction with intraocular lens implantation in the right eye. Preoperatively, the anterior lens capsule appeared normal. OBSERVATIONS: A double-ring sign was observed during capsulorrhexis. During intraocular lens implantation, the capsule developed radial tears, and a double layer of the capsule was noted. The patient's postoperative course was uneventful. CONCLUSIONS: The findings in our patient may be uncommon and may differ from but resemble true exfoliation.

Aged↗

PubMedDate not supplied

Tenascin-C levels in pseudosynovial fluid of loose hip prostheses.

OBJECTIVE: Aseptic loosening is one of the most important problems that can occur after total hip arthroplasty (THA). In this study, we analysed levels of large tenascin-C (TN-C) variants and compared them in pseudosynovial fluid from patients with aseptic loosening after THA with those in synovial fluid from patients undergoing primary THA (control). METHODS: Pseudosynovial fluid samples (n = 24) were obtained by aspiration at the time of revision THA performed due to aseptic loosening. Synovial fluid samples (n = 12) were obtained by aspiration at the time of primary THA. Expression of TN-C splice variants was examined using immunoblotting. TN-C levels were measured using an enzyme-linked immunosorbent assay (ELISA) system that we developed previously. RESULTS: Western blotting showed the presence of large TN-C variants in pseudosynovial fluid of artificial joints with loosening. TN-C levels were approximately three times higher in pseudosynovial fluid of loose artificial joints (median 151.9 ng/mL) than in synovial fluid controls (median 50.1 ng/mL) (p = 0.035). CONCLUSION: Levels of TN-C including large variant subunits are elevated in pseudosynovial fluid of loose artificial joints, indicating that TN-C is a useful novel biochemical marker of loose hip prostheses.

Aged↗

PubMedDate not supplied

A thermostable acid alpha-glucosidase from Tetrahymena thermophila: purification and characterization.

An acid alpha-glucosidase (EC 3.2.1.20) was purified to homogeneity from the culture medium of Tetrahymena thermophila CU 399. Its general molecular, catalytic and immunological properties were compared to those of the T. pyriformis W enzyme. The enzyme from T. thermophila was a 105-kD monomer and the N-terminus (25 amino acid residues) displayed some homology with that of T. pyriformis enzyme. The purified enzyme was most active at 56 degrees C and showed resistance to thermal inactivation. The acid alpha-glucosidase appears to have alpha-1,6-glucosidase as well as alpha-1,4-glucosidase activity. The Km values determined with p-nitrophenyl-alpha-glucopyranoside, maltose, isomaltose and glycogen were 0.7 mM, 2.5 mM, 28.5 mM and 18.5 mg/ml, respectively. The enzyme was antigenically distinct from T. pyriformis acid alpha-glucosidase.

Amino Acid Sequence↗

PubMedDate not supplied

Chronic lisuride hydrogen maleate administration enhances muscarinic receptor binding in senescent rat brain.

Changes in the regional density of muscarinic-1 (M1) receptors and the effect of lisuride hydrogen maleate on these changes were studied in senescent rat brain by in vitro autoradiography. In young adult controls, M1 receptor binding was most dense in the striatum and hippocampus, followed by the cerebral cortex and amygdala. Binding to M1 receptors was markedly lower in these areas of the senescent brain compared with the young adult brain. These decreases were reversed by intraperitoneal administration of 50 micrograms/kg.day lisuride for 14 days. The present results indicate that the therapeutic efficacy of lisuride depends on normalization of not only monoamine systems but also acetylcholine systems.

Age Factors↗

PubMedDate not supplied

A survey regarding the disclosure of the diagnosis of cancer in Toyama Prefecture, Japan.

A survey regarding the revelation of the diagnosis of cancer to patients was conducted on 116 medical doctors (MD), 206 paramedical personnel (PP) and 789 lay persons (LP) in June 1989 in Toyama prefecture, Japan. When asked in the case that their parents or spouse had cancer, only 29.8% of all respondents answered that they would reveal the diagnosis of cancer to their family member. On the contrary, if they themselves had cancer, 56.3% of all respondents answered that they wished the diagnosis to be revealed, and 77.4% of these answered that they wished to be informed of the cancer diagnosis by the doctor in charge. They wanted to know the details of their condition from their medical doctor, and thought that they could receive this knowledge calmly. Thirty-one percent (34/108) of the doctors questioned reveal the diagnosis of cancer to their patients and 79.4% of these answered that they felt that telling the true diagnosis was good. A serious responsibility for the medical doctor was indicated.

Adult↗

PubMedDate not supplied

Coronary risk factors in angiographically defined patients with chest pain.

Coronary risk factors were assessed in 186 consecutive patients who received coronary angiography. The severity of coronary luminal narrowing was scored as the coronary sclerosis index (CSI). Patients were divided into normal coronary arteries (N, n = 72), coronary sclerosis without infarction (C, n = 73) and previous myocardial infarction (MI, n = 41). The CSI increased with age. A significant difference in serum triglycerides, HDL cholesterol and atherogenic index was observed between Groups C or MI and N. Multivariate analysis revealed that CSI had correlated with total- and HDL-cholesterol, uric acid and age in subjects under 55 years; and with age, blood sugar, factor H and HDL cholesterol in those of 55 years or over. When patients were classified by their total and LDL cholesterol level, a significantly different CSI was found between the desirable and high cholesterol levels in subjects under the age of 55, but it was not significant in those over 55. Therefore, disorders in lipid metabolism should be corrected in early middle age.

Adult↗

PubMedDate not supplied

Cycloprodigiosin hydrochloride, a H+/Cl- symporter, induces apoptosis in human colon cancer cell lines in vitro.

Recently, we reported that cycloprodigiosin hydrochloride (cPrG.HCl), a novel H+/Cl- symporter, induces acidification of the cytosol and leads to apoptosis on rat and human liver cancer cells. In the present study, the effects of cPrG.HCl, a H+/Cl- symporter, were examined in colon cancer cell lines in vitro. In the MTT assay, cPrG.HCl inhibited the growth of two colon cancer cell lines (WiDr and SW480) in a dose- and time-dependent manner. The cPrG.HCl treatment of both types of cells induced apoptosis as confirmed by the appearance of a sub-G1 population and intranucleosomal DNA fragmentation. In addition, cPrG.HCl lowered pHi (below pH 6.8) respectively. Therefore, these results suggest that cPrG.HCl may be useful for the treatment of colon cancer cells.

Antiporters↗

PubMedDate not supplied

Effects of bifemelane hydrochloride on loss of N-methyl-D-aspartate receptor and muscarinic cholinergic receptor binding in the gerbil hippocampus after transient ischemia.

The effects of bifemelane hydrochloride on changes of N-methyl-D-aspartate receptors and muscarinic cholinergic receptors were examined in the gerbil hippocampus after transient ischemia with radioactive-specific ligands. There were marked reductions in both these receptors in the gerbil hippocampus 14 days after transient ischemia, without changes in the respective affinities. Post-ischemia bifemelane treatment almost completely prevented the ischemia-induced decreases in the numbers of these receptors, and had no effect in sham-operated controls. The results of the present study suggest that this drug prevents postsynaptic dysfunction induced by transient ischemia, and may be useful in the therapy of both the chronic and the acute stage of cerebrovascular disease.

Animals↗

PubMedDate not supplied

Effects of chronic administration of lisuride hydrogen maleate on aromatic amine and metabolite levels in the gerbil brain following bilateral common carotid ligation.

Cerebral monoaminergic neurotransmitters and their metabolites show various concentration changes in gerbils following bilateral carotid ligation. The present study evaluated the effect of chronic administrations of lisuride hydrogen maleate (lisuride) on these changes. Lisuride (0.01 mg/kg or 0.05 mg/kg) or vehicle was intraperitoneally administered to gerbils for 14 consecutive days before the induction of a 30 min ischemia by bilateral carotid ligation. Animals were sacrified immediately and the levels of dopamine, DOPAC, homovanillic acid, noradrenaline, serotonin and 5-hydroxyindoleacetic acid determined by HPLC in the striatum, cortex, hippocampus and diencephalon/midbrain. Lisuride itself had no effect on any compound determined in any region. In the carotid-ligated gerbil brain, however, lisuride corrected the reduction of dopamine in the striatum, normalized or reduced increases in the (DOPAC+homovanillic acid)/dopamine ratio in the striatum, hippocampus and diencephalon/midbrain, and increased the levels of serotonin in all four regions. The present study, together with previous reports, indicate that lisuride may interfere with ischemia-induced cerebrovascular disturbances and, in such a way, improve some pathological sequelae of cerebrovascular disease.

Animals↗

PubMedDate not supplied

Clinical analysis of cancer patients with bacteremia for the past ten years (1982-1991).

A trend in bacteremia associated with malignancies was studied in 159 cancer patients (pts) over the past ten years (1982-1991) in our university hospital. The proportion of female, aged persons and patients from the Int Med Dept had a tendency to increase in the later 5 years compared to the former 5 years. There was no significant change in proportion among G (+), G (-) and fungus groups. However, St. aureus has a tendency to increase among G (+) bacteria and Ps. aeruginosa among G (-) bacteria. The clinical features of the cancer patients with bacteremia were different depending on the types of organisms or kinds of underlying malignancies.

Adult↗

PubMedDate not supplied

Clinical evaluation of five tumor marker assay in patients with lung cancer.

Five tumor markers (CA19-9, CEA, NSE, SCC, TPA) were measured concomitantly in the serum of 128 patients with primary lung cancer (LC), 148 patients with benign disease (B) and 43 normal volunteers. The positive rates for all the tumor markers were significantly higher in the LC group than in the B group. When multiple tumor markers were quantitated, the specificity for the detection of lung cancer became lower although the sensitivity increased. However, this negative point was made up for to some extent by evaluating the number of positive markers. In monitoring the clinical course, independent changes were observed in markers in some cancer patients. These results implied that measuring multiple tumor markers was of clinical value in monitoring the clinical course of cancer patients as well as in assisting the diagnosis of lung cancer.

Antigens, Neoplasm↗

PubMedDate not supplied

Computed tomographic evaluation of adrenal glands in patients with bronchogenic carcinoma.

One hundred thirty-four patients with histo-pathologically proven bronchogenic carcinoma underwent computed tomography (CT) of the thorax and adrenal glands. Prospectively, 23 of the 134 patients had adrenal metastasis, based on CT criteria for enlargement of the gland. Retrospectively, however, some proved to be false positives. In addition, the diagnosis of adrenal metastasis frequently altered the initial staging and the treatment modality. We suggest that valid diagnoses of adrenal metastases on CT scan be made on the basis of altered shape as well as on altered size of the gland.

Adenocarcinoma↗

PubMedDate not supplied

Effects of the acetylcholinesterase inhibitor ENA-713 on ischemia-induced changes in acetylcholine and aromatic amine levels in the gerbil brain.

The effects of a new acetylcholinesterase inhibitor, ENA-713, on ischemia-induced changes in acetylcholine, monoamines, and their metabolites, were studied in the gerbil. ENA-713 (0.2 mg/kg) or saline was administered intraperitoneally to gerbils 30 min before induction of cerebral ischemia by bilateral carotid occlusion. Pretreatment with ENA-713 mitigated the ischemia-induced abnormalities of the cholinergic, dopaminergic and serotoninergic systems in the gerbil brain, although it had virtually no effect on acetylcholine, monoamines, or their metabolites in any region of the normal gerbil brain. These findings suggest that ENA-713 has beneficial effects against ischemia-induced cerebral disorders. Thus, ENA-713 seems to be promising as a preventive or therapeutic agent for cerebrovascular dementia due to cerebral ischemia and might be useful for the treatment of Alzheimer-type dementia which is associated with multiple neurotransmitter abnormalities in the brain.

Acetylcholine↗