Biomedical subjects

H Higuchi

Publications and source records attributed to H Higuchi.

348 records · Page 20Linked to original sources

PubMedDate not supplied

Antiretroviral activities of anthraquinones and their inhibitory effects on reverse transcriptase.

Alizarin complexone (AC), alizarin Red S (ARS) and various other anthraquinones were evaluated for their inhibitory effects on Rous-associated virus 2 reverse transcriptase (RAV-2 RT). Some 1,2-dihydroxyanthraquinones were active against this enzyme and AC was the most potent inhibitor among these compounds [50% inhibitory concentration (IC50): 3.8 micrograms/ml]. AC slightly inhibited Rous sarcoma virus RT (RSV RT) and human immunodeficiency virus type 1 RT (HIV-1 RT) (IC50: 100 micrograms/ml and 45 micrograms/ml, respectively). However, AC efficiently inhibited focus formation by Rous sarcoma virus (RSV) and cytopathogenicity of human immunodeficiency virus type 1 (HIV-1). Simultaneous administration of AC with RSV to newborn chickens also delayed tumor induction by RSV.

Animals↗

PubMedDate not supplied

Detection of serum haptoglobin by enzyme-linked immunosorbent assay in cows with fatty liver.

Haptoglobin cannot be detected in the serum of healthy cattle by the haemoglobin-binding assay or single radial immunodiffusion. The present study was designed to examine whether an enzyme-linked immunosorbent assay could be applied to measure serum haptoglobin concentrations in healthy cows and in cows with fatty liver. When either purified cow haptoglobin or haptoglobin-positive serum were used as the antigen in the assay, the standard curves obtained were distinctly different, and haptoglobin in serum was detected more sensitively than the purified protein. The addition of bovine serum albumin to purified haptoglobin shifted the curve towards that obtained with haptoglobin-positive serum, suggesting that an interaction with serum albumin was partly responsible for the different standard curves. By use of the standard curve for haptoglobin in serum, the mean (SEM) concentration of haptoglobin in samples from four cows with fatty liver was 466 (147) micrograms ml-1, but the sera from four apparently healthy cows contained less than 0.01 microgram ml-1 haptoglobin.

Animals↗

PubMedDate not supplied

Comparison of superoxide production, protein kinase C and tyrosine kinase activities in neutrophils from neonatal calves and cows.

Superoxide (O2) production and intracellular signal transduction of neutrophils were evaluated in five Holstein dairy calves and five lactating cows. Opsonised zymosan (OPZ)-induced O2 production by neutrophils from neonatal calves was significantly higher (P<0.01) than that of neutrophils of cows, whereas heat-aggregated IgG (H-agg.IgG)- and phorbol myristate acetate (PMA)-induced O2 production of neutrophils were significantly lower (P< or =0.01) than those of cows. To clarify the functional differences of intracellular signal transduction in neutrophils between neonatal calves and cows, the activities of protein kinase C (PKC) and tyrosine phosphorylation were evaluated in OPZ-, H-agg.IgG- and PMA-stimulated neutrophils. Membrane-associated PKC activity of OPZ-stimulated neutrophils from neonatal calves was significantly higher (P<0.05) than that of cows, whereas PKC activity in membrane-associated fractions of H-agg.IgG-stimulated neutrophils from neonatal calves was significantly lower (P<0.05) than that of cows. A significant difference was not found in membrane-associated PKC activity of neutrophils stimulated with PMA between neonatal calves and cows. The amount of tyrosine phosphorylated 100 kDa protein in neutrophils from neonatal calves stimulated with OPZ, H-agg.IgG and PMA were 192.6, 67.8 and 97.2 per cent of those of cows, respectively. These results indicate that complement receptor type 3 (CR3)- and Fc receptor (FcR)-mediated O2 producing activities of neutrophils are clearly different between neonatal calves and cows. This phenomenon may be associated with the age-related changes in intracellular signal transduction of neutrophils including PKC activity and tyrosine phosphorylation of cellular protein.

Aging↗

PubMedDate not supplied

Development of parkinsonian symptoms after discontinuation of carbamazepine in patients concurrently treated with risperidone: two case reports.

SUMMARY: We report here the development of parkinsonian symptoms after carbamazepine discontinuation in two patients concurrently treated with risperidone. They had been receiving combined treatment of carbamazepine and risperidone for the control of aggressive behavior and psychotic symptoms. The parkinsonian symptoms had not occurred before carbamazepine discontinuation, and have achieved complete remission after the dose reduction of risperidone. These findings suggest that the development of parkinsonian symptoms may be associated with pharmacokinetic interaction between carbamazepine and risperidone.

Aged↗

PubMedDate not supplied

Characterization of major phosphoproteins in the cGMP-mediated protein phosphorylation system of vascular smooth muscle membranes.

G(0) (215-250 kD) and G(1) (120-140 kD), the unidentified major phosphoproteins in the cGMP-mediated protein phosphorylation system of vascular smooth muscle membranes, were compared for biochemical and immunological properties with the type 1 inositol 1,4, 5-trisphosphate receptor (InsP(3)R, 240 kD) and the myosin-binding subunit (MBS, 138 kD) of myosin phosphatase, both of them substrates for cGMP-dependent protein kinase. Two microsomal proteins that were immunoreactive with antibodies to InsP(3)R and MBS were detected, and comigrated with G(0) and G(1), respectively, on SDS-PAGE. When thiophosphorylated G(0) and G(1) were subjected to immunoprecipitation, MBS antibody induced the precipitation of a 138-kD phosphoprotein, but did not significantly affect the amount of G(1) remaining in the supernatant, while InsP(3)R antibody precipitated G(0) almost completely. Unexpectedly, InsP(3)R antibody coprecipitated a large portion of G(1), which did not cross-react with either antibody to MBS or InsP(3)R. Just like InsP(3)R, G(0) bound to the calmodulin column in a Ca(2+)-dependent manner, and, again, a large portion of G(1) was copurified with G(0). These results suggest that G(0) is identical to InsP(3)R, while G(1) consists of several phosphoproteins, including the 138-kD protein associated with InsP(3)R as a major component. MBS is not G(1) or may represent only a minor component of it.

Animals↗

PubMedDate not supplied

Marked improvement of tardive dystonia after replacing haloperidol with risperidone in a schizophrenic patient.

We report on a schizophrenic patient whose tardive dystonia, delusions, and auditory hallucinations showed remarkable concurrent improvement after replacing haloperidol with risperidone. The present finding suggests that the 5-hydroxytryptamine-2 (5-HT2) antagonistic action of risperidone has brought about the improvement in tardive dystonia. The 5-HT2 antagonistic action of risperidone, in addition to its dopamine antagonistic action, may have also lessened psychotic symptoms in the current case.

Antipsychotic Agents↗