Search PubMed⌕ Search

Biomedical subjects

S Hirano

Publications and source records attributed to S Hirano.

At least 361 records · Page 20Linked to original sources
PubMed1986

Gangliosides in human and monkey lenses.

The amount of gangliosides was determined in normal human lens, cataractous human lens and normal monkey lens. The total gangliosidic sialic acids averaged 176.3 +/- 44.7 (SD) (n = 4) in normal human lenses, and 272.2 +/- 80.6 (n = 14) nmol per gram wet weight in cataractous lenses, respectively; the difference was statistically significant. In monkey lens, the content was 143.8 +/- 32.4 (n = 4) nmol per gram wet weight. The composition of the gangliosides was analyzed by high performance thin-layer chromatography: the components of the a-pathway biosynthesis comprised 78.3% and 70.2%, and those of the b-pathway 13.8% and 20.9%, in the normal and cataractous human lenses, respectively. In the monkey lens, the components of the a-pathway comprised 33.0% and those of the b-pathway were 56.6% of the total gangliosides. Increase in gangliosides was thought to be related with the mechanism underlying formation of cataract.

Animals↗
PubMed1986

[Effect of (2"R)-4'-O-tetrahydropyranyladriamycin, a new antitumor antibiotic, on the cardiac function of hamsters].

Cardiovascular effects of (2''R)-4'-O-tetrahydropylanyladriamycin X HCl (THP) and doxorubicin (adriamycin, ADM) were studied in hamsters. In experiments to observe acute effects, THP was administered intravenously at a dose of 12.5, 25.0 or 50.0 mg/kg, and ADM at 1.56, 3.13 or 6.25 mg/kg was given to different subjects. The THP caused slight ECG alterations at a dose of 12.5 mg/kg. At a dose of 25.0 mg/kg or 50.0 mg/kg, THP caused moderate to remarkable alterations in ECG like a widening of PR and PRc interval, A-V block, ST segment depression and T wave flattening. The ADM caused moderate to remarkable alterations in ECG at a dose of 3.13 mg/kg or 6.25 mg/kg, including arrhythmia, bradycardia, A-V block, ST segment changes and T wave flattening. These changes caused by THP and ADM recovered within 5 approximately 10 minutes after injection. Alterations in the ultrastructure of the myocardium caused by THP at a dose of 50.0 mg/kg included some cells with slight changes like swelling of mitochondria, focal intracellular edema, and enlargement of myofibrils. The ADM, at a dose of 3.13 mg/kg, induced severer swelling of mitochondria than THP, dilatation of sarcoplasmic reticulum, intracellular edema, and disorganization of myofilaments. At a dose of 6.25 mg/kg of ADM, these changes became more pronounced. In experiments to observe subacute effects, hamsters were treated with THP or ADM by daily intraperitoneal injections for 15 consecutive days, and then allowed to be recovered for 15 days. Dose levels of THP or ADM were 0.125, 0.25, 0.5 and 1.0 mg/kg. General toxicity, ECG, hematological and blood biochemical analysis, and electron microscopic examination were studied. In the ECG study, THP-treated hamsters showed a reversible elevation of R wave amplitude at a daily dose of 0.5 mg/kg. Widening of PR and PRc interval, elevation of R and S wave amplitude, and reduction of T wave amplitude were observed at a daily dose of 1.0 mg/kg of THP. Hamsters treated with ADM showed increase of heart rate, reduction of T wave amplitude, and shortening of PR and PRc interval at a daily dose of 0.5 mg/kg. Severe changes were observed at a daily dose of 1.0 mg/kg of ADM including an increase of heart rate, elevation of R wave amplitude, reduction of S and T wave amplitude, and shortening of QT interval. The electron microscopic examination revealed that THP-treated hamsters showed separation of intercalated discs, formation of myelin structure, and dilatation of T-tubules at a daily dose of 1.0 mg/kg. Similar changes were caused by ADM at a daily dose of 0.25 to 1.0 mg/kg.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1986

[A clinical observation on aged patients subjected to urological surgery].

A clinical analysis was made on 44 inpatients over 80 years old at our department from 1980 to 1984. Forty-three urological surgeries were performed on 36 out of the 44 patients, accounting for 3.4% of all the inpatients. Benign prostatic hypertrophy, which was the most popular disease in our study, was seen in 20 patients. Preoperative examinations revealed one or more complications besides urological disorders in 35 patients (97.5%), 11 patients of which needed some prophylactic treatments prior to urological surgery. Although major postoperative complications consisted of heart disease in 4 patients, gastrointestinal tract disease in 3 patients, and pulmonary disease in 2 patients, there was no operative death. Postoperative laboratory test results revealed hypoproteinemia in 16 patients (44.4%). Postoperative urological complications such as wound dehiscence, urinary fistula, or acute epididymitis occurred in 9 patients, all of whom had urinary tract infections. These results suggest that aged patients have fewer problems if extensive preoperative examinations and active treatments for any abnormality are made and careful attention is paid to postoperative complications.

Aged↗
PubMed1986

A mutant adenine phosphoribosyltransferase in 2,8-dihydroxyadenine urolithiasis.

In one case of 2,8-dihydroxyadenine urolithiasis, reduced adenine phosphoribosyltransferase activity was found. The patient's enzyme had normal affinity for adenine but reduced affinity for substrate phosphoribosyl-pyrophosphate. It was much more stable at 60 degrees C than control. It seems that erythrocyte adenine phosphoribosyltransferase obtained from the patient may be a variant enzyme.

Adenine↗
PubMed1985

Effect of sulfated derivatives of chitosan on some blood coagulant factors.

The effect of some sulfated derivatives of chitosan on several blood-coagulant factors was examined in comparison with those of heparin (174 units/mg). The anticoagulant activity (units/mg) with respect to activated partial thromboplastin time was 331-379 for O-sulfated N-acetylchitosan (2), 190-287 for N, O-sulfated chitosan (1), and 21-31 for sulfated O-carboxymethylchitosan (3). The activity (units/mg) with respect to thrombin time was 70-87 for 2, 44-70 for 1, and 14-22 for 3. The activity (units/mg) with respect to antithrombin activity was 4.9-9.0 for 2, 4.7-8.7 for 1, and 3.3-6.0 for 3. No anti-(factor Xa) activity was observed with 1-3. A 6-sulfate group in the hexosaminyl moiety was a main active site; although a 3-sulfate group was not essential, it promoted the activity of the 6-sulfate group. N-Sulfate was not a prerequisite for activity. The biological activities were also related to molecular weight in the sequence 2 (26,000) greater than heparin (21,000) greater than 1 (12,000) greater than 3 (540,000). For the Methylene Blue complexes, 1, but neither 2 nor 3, exhibited a negative, induced Cotton effect similar to that of heparin.

Blood Coagulation Factors↗
PubMed1985

The blood compatibility of chitosan and N-acylchitosans.

A segment of silk polyfilament suture [No. 2-0(USP)], ca. 10 cm long, was coated with a thin membrane (2-6 micron) of chitosan, N-acetylchitosan, or N-hexanoylchitosan. The suture was directly inserted into the lumen of dog's peripheral veins. The in vivo blood compatibility of these membranes was macroscopically determined from the blood coagulum formed on the membrane surface at 2 h. An intense thick blood coagulum formed on the chitosan membrane surface and a thin blood coagulum formed on N-acetylchitosan membrane surface, but no blood coagulum formed on N-hexanoylchitosan membrane surface.

Animals↗
PubMed1985

Transfer of hexachlorobenzene (HCB) from mother to newborn baby through placenta and milk.

HCB was detected in all preparations of human placenta, maternal blood, milk, and cord blood. It was confirmed that HCB transferred from mother to fetus through the placenta. A significant linear correlation exists between the HCB concentration in placenta and that in cord blood. Therefore, the placental concentration of HCB is an accurate indicator of HCB contamination in pregnant women and in the newborn baby. It was decided that the commercial pesticides, PCNB and PCP, contained HCB at a concentration of about 0.7 and 0.4% of pesticides, respectively. The animals which consumed PCNB diet accumulated large amounts of HCB in lipid-rich tissues, especially in adipose tissue. On the other hand, PCNB was metabolized to methylthiopentachlorobenzene and bis(methylthio)tetrachlorobenzene. One of the main sources of HCB contamination in the general population in Japan may be derived from the commercial pesticides, PCNB and PCP.

Adipose Tissue↗
PubMed1985

Effects of hyperphenylalaninemia in the fetal stage on the postnatal development of fetal rat brain.

The effect of exposure at different prenatal stages to maternal hyperphenylalaninemia (HyPhe) on the somatic and neurological development of fetuses in rats was studied, with special respect to the change of relevant enzyme activities in the brain. While evident somatic damage was found only in the fetuses exposed to maternal HyPhe at a last stage of gestation, distinct mental retardation seemingly due to some irreversible damage to the brain was observed in all the treated fetuses regardless of the timing of exposure, and a significantly reduced activity of 2', 3'-cyclic nucleotide 3'-phosphohydrolase (CNPase), a marker enzyme of myelin, was confirmed in the mantle region of the brain.

2',3'-Cyclic Nucleotide 3'-Phosphodiesterase↗
PubMed1985

Localization of ganglioside GM1 on myelin, in dissociated cells from rat embryonic cerebral hemispheres, using biotinylated choleragen and avidin peroxidase.

The distribution of ganglioside GM1 in primary cultured cells from rat cerebral hemispheres was studied. These dissociated cell cultures are capable of forming myelin. 2',3'-Cyclic nucleotide 3'-phosphodiesterase (CNPase) activity, which is considered to be a good marker for myelin, increased with the onset of myelin formation. Ganglioside GM1 was localized on the myelin-related structures using a biotinylated choleragen and avidin peroxidase technique. The distribution of ganglioside GM1 resembled that of immunostained CNPase.

2',3'-Cyclic-Nucleotide Phosphodiesterases↗
PubMed1985

A case of eruptive keratoacanthoma treated by oral etretinate.

A 63-year-old woman with eruptive keratoacanthomas on sun-exposed skin is reported. Attempts were made to produce lesions by the application of a tumour homogenate to the scratched skin, followed by UV-B irradiation; this was positive in two out of three sites, but these factors were probably non-specific stimuli. Treatment with oral etretinate led to most of the tumours disappearing within a month. Recurrence was seen on stopping the drug. Recommencement of therapy followed by a maintenance dose of 10 mg on alternate days, has been associated with freedom from the skin lesions.

Etretinate↗
PubMed1985

Pharmacokinetics of ceftazidime in patients with renal insufficiency and in those undergoing hemodialysis.

The pharmacokinetics of ceftazidime, a new cephalosporin antibiotic, were studied in 7 healthy volunteers and 32 patients with renal insufficiency after a single 500-mg intravenous injection. The mean plasma half-life during beta-phase was 1.67 h in normal subjects and was prolonged to 15.09 h in hemodialysis patients. There were significant correlations between the elimination rate constant and the creatinine clearance, and between the beta-phase rate constant and the creatinine clearance. The mean urinary recovery during 24 h amounted to 89.6% of the dose in normal subjects and decreased with the lowering of renal function. The plasma levels during hemodialysis were lower than those between hemodialyses.

Adult↗
PubMed1985

Myelin formation in dissociated cell cultures of rat embryonic cerebral hemispheres.

Developing cultures of dissociated cerebral hemispheres obtained from 18-day-old embryonic rats synthesized, or activated, a myelin-related enzyme, 2',3'-cyclic nucleotide 3'-phosphohydrolase (CNPase). This increase in activity coincided with the onset of myelination. The presence of CNPase in oligodendrocytes and myelin was demonstrated using immunocytochemical staining techniques. Myelinated axons and myelin sheaths were clearly made visible by electron microscopy of 28-day-old cultures.

2',3'-Cyclic Nucleotide 3'-Phosphodiesterase↗