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Biomedical subjects

H Kamiya

Publications and source records attributed to H Kamiya.

At least 289 records · Page 16Linked to original sources

Influences of cyclooxygenase inhibitors on the cataleptic behavior induced by haloperidol in mice.

Haloperidol administered intraperitoneally, and prostaglandin F2 alpha (PGF2 alpha) and PGE2 intraventricularly induced dose-dependent cataleptic behavior in mice. The cataleptic behavior induced by haloperidol was inhibited dose-dependently by oral pretreatment with aspirin and indomethacin, inhibitors of PGs synthetase. Striatal 3,4-dihydroxyphenylacetic acid (DOPAC) and 5-hydroxyindole 3 acetic acid (5-HIAA) were elevated by haloperidol, although dopamine (DA) and 5-hydroxytryptamine (5-HT) levels did not change. The increase of DOPAC level in striatum induced by haloperidol was significantly suppressed by aspirin, but not in brain stem. The alteration of DOPAC level by aspirin correlated with the behavioral response. These results suggest that central prostaglandin synthesis may participate in the development of cataleptic behavior, which might also involve alteration of brain catecholaminergic activity.

3,4-Dihydroxyphenylacetic Acid↗

Breast angiosarcoma metastatic to the maxillary gingiva. Case report.

A case of breast angiosarcoma metastatic to the maxillary gingiva is reported. A review of the literature revealed only three previously reported cases. Angiosarcomas often present as benign lesions. The surgeon should maintain a high level of vigilance when patients present with oral lesions and a history of breast tumor.

Breast Neoplasms↗

Activation of lymphocytes by varicella-zoster virus (VZV): expression of interleukin-2 receptors on lymphocytes cultured with VZV antigen.

The expression of human leukocyte antigen (HLA-DR) and interleukin-2 receptor (IL-2R; alpha and beta subunits) was significantly increased in peripheral blood mononuclear cells (PBMC) from varicella-zoster virus (VZV)-seropositive donors when PBMC were cultured with VZV antigen for 6 days. The increased expression of HLA-DR and IL-2R was observed in both CD4+ and CD8+ lymphocytes, which suggests that both types of lymphocytes from VZV-seropositive donors were activated when PBMC were cultured with VZV antigen. Adding anti-IL-2R alpha did not inhibit lymphocyte proliferation in response to VZV antigen, although marked inhibition was obtained by adding anti-IL-2R beta. No IL-2 was detected in the supernatant of PBMC cultured with VZV antigen; however, antibody to IL-2 inhibited lymphocyte proliferation on exposure to VZV antigen. These results indicate that IL-2 and expression of IL-2R beta are essential to lymphocyte activation by VZV antigen.

Adult↗

Immunization of the elderly and patients with collagen vascular diseases with live varicella vaccine and use of varicella skin antigen.

Elderly subjects and patients with collagen vascular diseases were immunized with a live varicella vaccine to assess the vaccine's potential for preventing herpes zoster. An improved varicella-zoster virus (VZV) skin test antigen was then used to assess cell-mediated immunity to VZV. The antigen was prepared from culture fluid of VZV-infected cells and had far less protein content than crude antigen prepared by sonication of infected cells. In 11 of 12 patients with ophthalmic zoster and 17 of 21 with dermal zoster, the skin reaction was negative at the beginning of the disease but became positive later. After two doses of VZV vaccine, 8 of 12 elderly subjects (greater than 60 years old) and 4 of 6 patients with collagen vascular diseases, who were VZV-skin test negative but purified protein derivative tuberculin test-positive, became VZV skin test-positive.

Adolescent↗

Biopolymers from marine invertebrates. XIII. Characterization of an antibacterial protein, dolabellanin A, from the albumen gland of the sea hare, Dolabella auricularia.

An antibacterial factor, dolabellanin A, was purified from the albumen gland of a sea hare, Dolabella auricularia. Purified dolabellanin A was a glycoprotein of 250 kilodaltons consisting of 4 subunits, and showed both antibacterial and antineoplastic activities. The two activities were lost in parallel on heating and at low and high pH. This factor was half-maximally active for gram-positive and -negative bacteria at 0.018-0.48 microgram/ml, and its action was not bactericidal but bacteriostatic. Dolabellanin A did not induce morphological elongation of bacteria or the release of adenosine triphosphate, but it completely inhibited the syntheses of deoxyribonucleic acid (DNA) and ribonucleic acid by E. coli within 6 min. These results suggest that dolabellanin A, which is found in a marine invertebrate, the sea hare, is a new antibacterial protein, and that it exerts its action by inhibiting nucleic acid synthesis, as does a DNA-inhibiting chemotherapeutic drug.

Amino Acid Sequence↗

Biopolymers from marine invertebrates. XII. A novel cytolytic factor from a hermit crab, Clibanarius longitarsus.

Bioactive polymers were sought in marine arthropoda and a novel cytolytic factor was found in a hermit crab, Clibanarius longitarsus. The partially purified factor showed activity in fractions corresponding to a molecular weight of about 10 kilodaltons on a Sephadex G-75 column. This cytolytic factor was halfmaximally active for tumor cells at 0.13-0.66 micrograms/ml and for normal cells at 1.9-82 micrograms/ml. Tumor lysis by the factor was time dependent and was complete within 12 h. This bioactive polymer was labile on heating, at low and high pH.

Animals↗

In vitro replication study of modified bases in ras sequences.

DNA templates containing a modified base (O6-methylguanine, 8-hydroxyguanine, xanthine or hypoxanthine) which was located in nucleotide sequences corresponding to the 12th or 61st codon of a ras gene were synthesized and deoxynucleotide incorporation opposite the lesions was investigated. The templates were replicated by Taq DNA polymerase, recombinant rat DNA polymerase beta and mouse DNA polymerase alpha-primase complex. Sequence analysis of the replicated products indicated selective incorporation of nucleotide(s) opposite a modified base, depending on the kind of base and of DNA polymerase. This system is very useful to obtain results of in vitro replication of modified bases in ras sequences.

Animals↗

[MCNS, which secondary developed into incidental IgA nephropathy--a case report].

There have been a number of case reports on nephrotic syndrome with histological findings of minimal change on light microscopy and mesangial IgA deposition on fluorescent microscopy. The pathogenesis of these cases is, however, yet to be clarified. Here, we report a case of minimal change nephrotic syndrome (MCNS) associated with IgA nephropathy, which developed later in the course of MCNS. The patient was 18 years old male with steroid-responsive nephrotic syndrome. First episode of proteinuria occurred when he was 4 years old. On the fourth episode of proteinuria, renal biopsy revealed minimal change on light microscopy and no evidence of deposition of immunoglobulins or complements on immunofluorescent and electron microscopy. On the fifth relapse of MCNS, microhematuria developed concomitantly with massive proteinuria. Renal biopsy, then, showed light microscopic findings of mild focal segmental glomurulonephritis. Significant mesangial IgA deposition was observed on immunofluorescence study. Electron microscopy revealed electron dense deposit in the mesangial and paramesangial area. The patient was well-responsive to steroid although microhematuria persisted after disappearance of proteinuria. We concluded that IgA nephropathy may have developed subsequently in the course of MCNS in our case.

Adolescent↗

Mutations induced by DNA lesions in hot spots of the c-Ha-ras gene.

In order to investigate whether several DNA lesions (O6-methylguanine, 8-hydroxyguanine, xanthine, an abasic site analogue and hypoxanthine) activate a c-Ha-ras gene and to determine the type of mutations induced by the DNA lesions, they were introduced into a synthetic c-Ha-ras gene by DNA cassette mutagenesis techniques. The modified genes were transfected into mouse NIH3T3 cells and the c-Ha-ras genes present in transformed cells were analysed. O6-methylguanine and xanthine induced a mutation to A, hypoxanthine induced a mutation to G. 8-hydroxyguanine and the abasic site analogue caused random mutations in the modified and adjacent positions. These results indicated that the synthetic c-Ha-ras gene is very useful for the detection of mutations caused by a DNA lesion.

3T3 Cells↗

Five confirmed human cases of gnathostomiasis nipponica recently found in northern Japan.

Five confirmed human cases of gnathostomiasis nipponica exhibiting creeping eruption and itching were found sporadically from the autumn of 1991 to the winter of 1992 in the northern region of the mainland of Japan. In all cases, a causative gnathostome with 3 transverse rows of hooklets on the head bulb was detected in biopsied skin. The morphological characteristics agreed with the advanced third-stage larvae of Gnathostoma nipponicum. Within a few weeks before development of symptoms, all patients had histories of eating raw freshwater fishes, kokanee (Salmo nerka nerka), carp (Cyprinus carpio), crucian carp (Carassius gibelio langsdorfi), or common ice-fish (Salangichthys microdon). However, they had never eaten raw loach, which is known as a source of human infections with G. nipponicum.

Adult↗

[Pharmacokinetic, bacteriological and clinical studies on cefprozil in pediatric patients].

Cefprozil (CFPZ, BMY-28100), a new oral cephem antibiotic, was studied for its antibacterial activities, absorption and excretion upon administration. Its clinical efficacies were also studied in pediatric patients with infections. A study on antibacterial activities of CFPZ against 11 clinical isolates including 6 species found that its activities against Staphylococcus aureus, alpha-hemolytic Streptococcus, Escherichia coli and Haemophilus influenzae were equal or superior to those of CCL. When CFPZ was given to patients orally at 15 mg/kg, maximum serum concentration was obtained between 1 to 2 hours after administration and urinary excretion rate in the first 6 hours was 33.8 +/- 17.6%. Clinical evaluation was done in a total of 25 patients with various infections. Responses were excellent in 15 cases and good in 10 cases, hence the efficacy rate was 100%. As side effect, soft stool was found in 1 case, and eosinophilia in 2 cases and elevation of GOT and GPT in 1 case were found as abnormal laboratory test results, but none of them was serious. It appears that CFPZ is an effective and safe antibiotic in the field of pediatrics.

Bacteria↗

[Evaluation of panipenem/betamipron in pediatric field].

Panipenem/betamipron (PAPM/BP), a mixture of a newly synthesized carbapenem antibiotic panipenem (PAPM) and N-benzoyl-beta-alanine, betamipron (BP), was evaluated for pharmacokinetics, in vivo and in vitro antimicrobial effect, and clinical efficacy in pediatric patients. Intravenous drip infusion of either 10 mg/10 mg/kg or 20 mg/20 mg/kg of PAPM/BP for 30 minutes resulted in maximum plasma concentrations of 36.6 micrograms/ml and 92.5 micrograms/ml, half lives (T 1/2 beta) of 1.17 hours and 0.88 hours, and urinary excretion until 6 hours of 29% and 17.7%, respectively. Antibacterial activities of PAPM against Gram-positive cocci and Gram-negative rods isolated from pediatric patients were equal to or slightly stronger than those of imipenem, ceftazidime, cefoperazone, and piperacillin. Clinical effects of PAPM/BP evaluated in 17 patients were as follows; excellent in 8 cases, good in 8 cases, and fair in 1 case. The overall efficacy rate was 94.1%. Elevations of GOT and/or GPT were observed in 2 patients and transient eosinophilia was observed in 1 patient.

Adolescent↗

Persistent enhancement of transmitter release accompanying long-term potentiation in the guinea pig hippocampus.

In order to examine temporal changes in enhancement of transmitter release during long-term potentiation (LTP), we examined amplitude fluctuation of excitatory postsynaptic potentials (EPSPs) for longer periods than 2 h after tetanic stimulation (up to 4 h in the longest observation). The relative magnitude of excitatory postsynaptic potentiation (EPSP) fluctuation (coefficient of variation, CV) reduced throughout the observation periods in association with an increase in EPSP amplitude after tetanic stimulation. The reciprocals of squared CVs (= mean2/variance) were almost in proportion to the magnitude of LTP, and the ratio of 1/CV2 and the LTP magnitude did not change significantly for up to 4 h. These findings suggest that a prolonged enhancement of transmitter release from presynaptic terminals underlies LTP, and the relative contribution of this presynaptic enhancement does not change significantly for 2 h (maybe up to 4 h, or longer) after tetanic stimulation.

Animals↗

The central pressor actions of a novel tachykinin peptide, gamma-preprotachykinin-(72-92)-peptide amide.

Intracerebroventricular (i.c.v.) injections of a novel tachykinin peptide, gamma-preprotachykinin-(72-92)-peptide amide (neuropeptide gamma, NP gamma), caused dose-dependent increases in blood pressure. The NP gamma-induced pressor responses (1 microgram i.c.v.) were blocked by peripheral administration of pentolinium (10 mg/kg i.v.) and phentolamine (10 mg/kg i.v.), but were not inhibited by a vasopressin antagonist. These results suggest that central NP gamma increases the blood pressure via sympathetic nerve activity.

Animals↗

Quantal components of the synaptic potential induced in hippocampal neurons by activation of granule cells, and the effect of 2-amino-4-phosphonobutyric acid.

The probabilistic nature of excitatory postsynaptic potentials (EPSPs) induced monosynaptically in CA3 neurons by impulses of granule cells was studied in thin transverse sections of the guinea pig hippocampus. More than 600 EPSPs were recorded under several conditions, their amplitudes were measured, and histograms representing the EPSP amplitude distribution were constructed. Quantal parameters were estimated by the method of maximum likelihood. Of 9 neurons examined in the control solution, one neuron showed an exceptionally large number of transmission failures. The amplitude distribution of EPSPs recorded from this neuron could be described by Pascal statistics, but not by binomial or Poisson statistics. The EPSP amplitude distribution from the other neurons could be described by either binomial, Poisson, or Pascal predictions with a minor preference for the last statistic. When an apparently homogeneous group of data was divided into two subgroups and parameters were estimated separately, inconsistent values were obtained in some neurons with no failures. 2-Amino-4-phosphonobutyric acid (APB) suppressed the EPSPs reversibly at relatively low concentrations. Theoretical curves calculated according to the Pascal statistics fit quite well to the entire amplitude distribution of EPSPs recorded under the action of APB. The suppression of EPSPs by APB was accompanied by a marked decrease in mean quantal content (m) with no significant reduction in mean quantal amplitude (q). A quantum induced an increase in membrane conductance of about 150 pS. These results suggest that the release probability of the mossy fiber terminal fluctuates temporally according to a gamma distribution, and that APB reduces the liberation of the transmitter from mossy fiber terminals, thereby suppressing transmission between mossy fibers and CA3 neurons.

Aminobutyrates↗

Some pharmacological differences between hippocampal excitatory and inhibitory synapses in transmitter release: an in vitro study.

The effects of adenosine, carbachol, and baclofen on synaptic transmission between neurons in cultured rat hippocampal explants were studied using the tight-seal whole cell clamp technique. In the culture, stimulations of neurites cause postsynaptic currents (PSCs) in nearby neurons under voltage-clamp condition. In the presence of 20 microM bicuculline, most PSCs were considered as glutamatergic excitatory postsynaptic currents (EPSCs), because they were blocked by glutamate antagonist, kynurenate at 1 mM. In the presence of 1 mM kynurenate, PSCs seemed to be inhibitory postsynaptic currents mediated by gamma-aminobutyric acid (GABA), because they were blocked by GABA antagonist, bicuculline at 20 microM. Adenosine at 100 microM and carbachol at 10 microM suppressed these EPSCs to about 35% of control. However, adenosine and carbachol at the same concentration did not suppress the IPSCs. Baclofen at 10 microM suppressed both EPSCs and IPSCs significantly (EPSCs: to about 40% of control, IPSCs: to about 30% of control). In contrast, membrane currents elicited by ionophoretically applied glutamate and GABA were not suppressed by 100 microM adenosine, 10 microM carbachol, and 10 microM baclofen. From these results, it is suggested that the pharmacological sensitivities of transmitter release from presynaptic terminals are different between glutamatergic excitatory synapses and GABAergic inhibitory synapses in hippocampal cultures.

Adenosine↗