Search PubMed⌕ Search

Biomedical subjects

T Hata

Publications and source records attributed to T Hata.

At least 505 records · Page 28Linked to original sources
PubMed1986

Abstinence improves cerebral perfusion and brain volume in alcoholic neurotoxicity without Wernicke-Korsakoff syndrome.

Twenty severe chronic alcoholic patients with signs of neurotoxicity but without Wernicke-Korsakoff syndrome were treated by abstinence from alcohol and examined prospectively at intervals thereafter. Serial examinations included detailed medical histories, neurological examinations, cognitive capacity screening examinations, computed tomography scans with measurements of sulcal and ventricular volume, and measurements of regional CBF. All sedatives were withdrawn before CBF measurements were made. Before treatment, gray matter blood flow values were significantly reduced compared with those of age-matched normal volunteers, but white matter blood flow values were normal and the ventricles were enlarged. After abstinence from alcohol, mean gray matter blood flow values and brain volume both increased significantly.

Adult↗
PubMed1986

Changes of total acetylcholine content and the activity of related enzymes in SART (repeated cold)-stressed rat brain and duodenum.

In SART-stressed rats regarded as pathologically diseased model animals with vagotonic-type autonomic imbalance, a decrease of total acetylcholine (T-ACh) content and enhancements of choline acetyltransferase (CAT) and acetylcholinesterase (AChE) activities were recognized in the basal ganglia and hypothalamus. In contrast, in the duodenum, an increase in T-ACh content and a decrease in AChE activity were found, while CAT activity showed no change. These findings suggest that in both brain areas of basal ganglia and hypothalamus in SART-stressed rats, ACh neurons may be activated.

Acetylcholine↗
PubMed1986

Total acetylcholine content, and activities of choline acetyltransferase and acetylcholinesterase in brain and duodenum of SART-stressed (repeated cold-stressed) rat.

The cholinergic activities in SART (specific alternation of rhythm in temperature)-stressed (repeated cold-stressed) rats, which are diseased rats with vagotonic-type dysautonomia, were examined with the following results. A decreased content of total acetylcholine (T-ACh) and increased activities of choline acetyltransferase (CAT) and acetylcholinesterase (ACh) in the basal ganglia and an increase in the T-ACh content and decrease in the AChE activity in the duodenum of SART-stressed rats reached the respective plateaus on day 5 of stress, which were maintained thereafter. CAT activity, however, in the hypothalamus was activated most on day 2. These changes in SART-stressed rats were different from those in simple cold-stressed rats. Subdiaphragmatic vagotomy inhibited the appearance of the changes in the duodenum, but not those in the hypothalamus of SART-stressed rats. The sedative analgesic Neurotropin prevented all the changes in SART-stressed rats described above. These results suggest that cholinergic neurons may be activated in both the hypothalamus and basal ganglia of the brain of SART-stressed rats, and the characteristic peripheral changes of the cholinergic system in the duodenum of SART-stressed rats may be under the control of the parasympathetic center.

Acetylcholine↗
PubMed1986

Changes of tissue blood flow in mice loaded with SART (repeated cold) stress or restraint and water immersion stress and the effect of administered neurotropin.

In order to explore the peripheral microcirculation and to obtain an outline of autonomic innervation in SART (specific alternation of rhythm in temperature)-stressed (repeated cold-stressed) animals, which are regarded as model animals for clinical vagotonic-type dysautonomia, peripheral tissue blood flow was determined in mice, using the hydrogen clearance method. SART-stressed mice showed a decrease in gastric blood flow, no change in hepatic blood flow and an increase in dermal blood flow. In the mice exposed to the restraint and water immersion stress (RWIS), a type of acute stress, in contrast with SART stress which is a subacute type, remarkable decreases were observed in gastric, hepatic and dermal blood flows. Changes of both gastric and dermal blood flow in SART-stressed mice were dose-dependently prevented and maintained within normal limits by the treatment with Neurotropin, a sedative analgesic which is an extract isolated from vaccinia virus-inoculated and inflamed skin of rabbits. In RWIS-loaded mice, Neurotropin exhibited a great preventive effect on changes of blood flow in the stomach, a slight effect in the liver, and no effect in the cutis. When mice were loaded with SART stress after left-cervical vagotomy, SART stress failed to elicit any decrease in gastric blood flow. In SART-stressed mice treated with 6-hydroxydopamine, gastric and dermal blood flows tended to show a further decrease and increase, respectively, over and above the changes caused by SART stress. From these results, it is suggested that SART-stressed mice may have decreased gastric parasympathetic tone, a decrease in sympathetic tone and also other anomalies such as increased tension of the sympathetic cholinergic vasodilator nerves in the cutis.

Animals↗
PubMed1986

[Fundamental and clinical studies on imipenem/cilastatin sodium in the field of obstetrics and gynecology].

The following results were obtained during pharmacokinetic, bacteriological and clinical evaluation of the usefulness of the combination (1:1) of imipenem (MK-0787) and cilastatin sodium (MK-0791), an inhibitor of dehydropeptidase-I, in the treatment of patients with obstetric and gynecologic infections. Plasma concentrations of MK-0787 in antecubital vein and uterine artery were 18.2 micrograms/ml and 16.4 micrograms/ml, respectively, and of MK-0791 were 9.5 micrograms/ml and 10.3 micrograms/ml, respectively, at 1.28 hours after the end of a drip infusion of 0.5 g/0.5 g of MK-0787/MK-0791. Plasma concentrations of both MK-0787 and MK-0791 decreased slowly, and concentrations of the former in antecubital vein and uterine artery were 0.7 micrograms/ml and 1.0 micrograms/ml, respectively, and of the latter were 1.5 micrograms/ml and 1.9 micrograms/ml, respectively at 2.83 hours after the end of a drip infusion. Concentrations of the 2 agents in female genital tissues decreased with increasing time in a manner similar to concentrations in the plasma. Clinical responses in 10 patients were excellent in 2 and good in 8, and the efficacy rate was 100 percent. Organisms were isolated from all 10 patients before the treatment, but were eradicated in 9 patients by the treatment. No side effects were observed, but increase of eosinocytes was observed in 1 patient.

Adolescent↗
PubMed1986

[Antenatal diagnosis of congenital heart diseases and fetal arrhythmias].

Fetal echocardiographic, electrocardiographic, and pulsed Doppler ultrasonic examinations were performed to detect congenital heart anomalies and fetal arrhythmias antenatally, from April 1980 to March 1985. In nineteen subjects, these techniques revealed premature atrial contractions (PAC) in five fetuses, PAC and blocked PAC in two, PAC and premature ventricular contraction (PVC) in one, PAC, blocked PAC and PVC in one, sinus bradycardia in one, congenital complete atrio-ventricular block in one, atrial septal defect with PAC and PVC in one, fetal unilateral hydronephrosis with PAC and PVC in one, complicated heart anomalies with dilated colon in one, single atrium and ventricle with esophageal and anal atresiae in one, complicated heart anomalies with encephalocele and single umbilical artery in one, and asymmetrical septal hypertrophy in one, antenatally. In nine out of fifteen cases with fetal arrhythmias, the arrhythmia resolved within the first month of life. Sustained arrhythmias occurred in three cases. In three cases with fetal arrhythmias, in utero therapies with Coenzyme Q10(CoQ10) were performed, and anti-arrhythmic effects of CoQ10 recognized. Deaths occurred in three cases with complicated heart anomalies.

Arrhythmias, Cardiac↗
PubMed1986

Ultrasonography for the diagnosis of adenomyosis.

An accurate preoperative diagnosis of uterine adenomyosis is often difficult. We reviewed our experience with ultrasound evaluation of this pathological entity. Patients with histologically proven adenomyosis were studied to determine the usefulness of ultrasound for the preoperative diagnosis of this entity. In patients with adenomyosis, variable ultrasound patterns are seen, namely, enlargement of the uterus, irregular vesicular spaces within the myometrium, and an acoustically enhanced posterior wall of the uterus. However, leiomyoma had a similar echopattern. Based on five cases of histologically extensive adenomyoasis, an accurate diagnosis of adenomyosis proved feasible when ultrasonography showed all three ultrasonic patterns mentioned above, associated with a retroverted uterus or possible adhesions between the uterus and structures in close proximity, nodule or outgrowth in the region of the uterosacral ligaments or in combination, as frequently found in conjunction with external endometriosis. The ultrasonographical demonstration of endometrial cyst of the ovary may contribute to an accurate diagnosis of adenomyosis.

Adult↗
PubMed1986

A Raman spectroscopic study on the sequence dependent conformations of DNA oligomers.

Eighteen kinds of oligodeoxyribonucleic acids have been examined to reveal their structures in aqueous solutions at different ionic strengths by Raman spectroscopy. The structures in solutions were found to be very polymorphic depending on their sequences as well as on the salt concentrations. At a low salt condition a DNA oligomer assumes a unique B form within a B family, for examples Ba, Bh, B', or Bn form. Amongst these DNA oligomers, d(CGCG)2 showed a salt induced Ba-Z transition, while d(GGGGCCCC)2 showed a salt induced Bh-A transition. DNA oligomers with AA/TT sequences were found to prefer B' form even at high salt condition. From comparing the structures of DNA oligomers in solutions with their crystal structures, it is safe to say that the crystal structure of a DNA oligomer is very similar to the structure in the high salt solution.

Base Sequence↗
PubMed1986

The phosphorothioite method. Synthesis of deoxyoligonucleotides on polymer supports by using nucleoside phosphorothioites.

The development of a new method, which is called "the phosphorothioite method", for synthesizing deoxyoligonucleotides on polymer supports is described. Nucleoside phosphorothioites were easily prepared and readily activated by iodine or silver acetate. In the case of the use of iodine, the present method did not require the oxidation step, because it could be simultaneously performed during condensation and thereby the reaction time could be shorten. This method was applied successfully to the polymer support synthesis.

Base Sequence↗
PubMed1986

[A study of the effect of (2"R)-4'-O-tetrahydropyranyladriamycin, a new antitumor antibiotic, on reproduction. II. Its teratogenicity in rats and rabbits].

This paper describes the embryotoxicity and teratogenic effects of (2"R)-4'-O-Tetrahydropyranyladriamycin (THP). The drug was administered intravenously to female rats at 0.01, 0.03, 0.1 or 0.3 mg/kg daily from day 7 to day 17 of pregnancy and to female rabbits at 0.01, 0.05 or 0.1 mg/kg daily from day 6 to day 18 of pregnancy. Results were summarized as follows. Rats THP, at the highest dose of 0.3 mg/kg, decreased body weight gains of pregnant females. This dose caused a decrease in body weights of fetuses, tendencies to increase the rate of death of fetuses or of resorption, an increase in the number of lumbar vertebrae and a delayed ossification of forelimbs of fetuses. Other parameters were not affected by THP at any dose levels. At any dose levels, THP did not produce external, visceral or skeletal malformations in the offspring (F1), nor did it affect the development, physiological functions, behavior, mating, fertility or pregnancy of the offspring. However, at the highest dose level, THP decreased the weight of testes of the offspring. The results suggest that the maximum "no effect" dose level of THP to pregnant females and offspring is 0.1 mg/kg/day intravenously. Rabbits The highest dose of THP, 0.1 mg/kg, decreased the consumption of food and water by pregnant females, but at any dose levels, it did not affect their body weight gain. THP did not cause teratological effects such as external malformation or visceral and skeletal anomalies in the fetuses at any dose levels tested. The results suggest that the maximum "no effect" dose of THP is 0.05 mg/kg/day intravenously to pregnant females and above 0.1 mg/kg/day intravenously to fetuses.

Abnormalities, Drug-Induced↗
PubMed1986

[A study on the effect of (2"R)-4'-O-tetrahydropyranyladriamycin, a new antitumor antibiotic, on reproduction. III. Its effects on perinatal and postnatal rats].

This paper describes effects of (2"R)-4'-O-tetrahydropyranyladriamycin hydrochloride (THP) on perinatal and postnatal rats. The drug was administered intravenously to female rats at 0.01, 0.03 or 0.1 mg/kg daily from day 17 of pregnancy to 21 days after delivery. Results were described below. At any dose levels tested, THP did not affect the body weight gain, food and water consumption by pregnant rats, and length of gestation period or delivery rate. However, at the highest dose level, THP decreased spleen weight. THP, at any dose levels, did not have toxic effect on development, physiological functions, behavior, mating, fertility or pregnancy of the first generation offspring (F1). At the highest dose of 0.1 mg/kg, however, THP produced delayed ossification of sacrococcygeal vertebra in the second generation fetuses (F2). The results suggest that the maximum "no effect" dose of THP to pregnant rats and offsprings is 0.03 mg/kg/day intravenously.

Animals↗
PubMed1985

Ultrasonographic identification and measurement of the human fetal adrenal gland in utero.

Ultrasonographic studies on the fetal adrenal gland were performed in utero on 100 fetuses 22-42 weeks of gestation. The correlations of the area of fetal adrenal gland (FAGA) with gestational age (r = 0.95, P less than 0.001) were high. The circumference of the fetal adrenal gland (FAGC) correlated well with the gestational age (r = 0.86, P less than 0.001) as did the length of this gland (FAGL) (r = 0.70, P less than 0.001). Ultrasonographic identification and measurement of the fetal adrenal gland in utero is thus an useful indicator to assess the growth and maturation of the fetal adrenal gland, and for detecting of congenital adrenal hyperplasia and hypoplasia.

Adrenal Glands↗
PubMed1985

Electrophysiological effect of disopyramide on rabbit sinus node cells.

The effects of disopyramide on the membrane potentials and currents of rabbit sinus node cells were studied using the conventional microelectrode and voltage clamp methods. Disopyramide (5 and 10 micrograms/m1) produced a negative chronotropic effect, and decreased the maximum rate of depolarization, the overshoot potential and the maximum diastolic potential. The action potential duration at half-amplitude was prolonged, and the slope of diastolic depolarization was reduced. In the voltage clamp experiments, disopyramide (10 and 50 micrograms/m1) reduced the potassium outward current (IK) without changing its kinetics. Disopyramide reduced the slow inward current Isi and increased the recovery time constant of Isi. The hyperpolarization-activated current (Ih) was also decreased by the drug. From these results, it is concluded that disopyramide has a depressant effect on the electrical activity of sinus node cells by mediating depression of IK, Isi and Ih.

Action Potentials↗