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Biomedical subjects

T Hata

Publications and source records attributed to T Hata.

At least 523 records · Page 29Linked to original sources
PubMed1985

Cerebral atrophy and hypoperfusion improve during treatment of Wernicke-Korsakoff syndrome.

Nineteen patients with sudden onset of impaired recent memory, cerebellar ataxia, peripheral neuropathy, and other signs of Wernicke-Korsakoff syndrome (WKS) were treated and examined prospectively for 3 months. Serial studies included histories, neurological examinations, cognitive capacity screening examinations (CCSE), computed tomography (CT) scans, and measurements of regional CBF. Patients were detoxified and withdrawn from sedatives before CBF measurements were examined. Treatment included alcohol withdrawal, nutritious diet, and 300 mg thiamine daily. Before treatment CCSE scores and blood flow values of both white and gray matter were reduced, particularly within both temporoparietal regions. After treatment of compliant patients (n = 10), white and gray matter blood flow increased concurrently with improved CCSE scores. Abnormal eye signs, ataxia, peripheral neuropathy, and performance of activities of daily living also improved. Cerebral atrophy and ventricular enlargement measured by CT decreased. Early recognition and treatment of WKS in compliant patients permit rapid reversals of cognitive and neurological impairments associated with increased blood flow of gray and white matter and improvements of brain atrophy measured by CT scanning.

Adult↗
PubMed1985

Effect of ginseng-20S-prosapogenin on tissue blood flow measured by the hydrogen clearance method in sympathicotonic- or parasympathicotonic-type stressed mice.

An attempt was made to investigate the preventive effects of 20S-prosapogenin (20S-PG), a partial hydrolyzate of diol saponins isolated from Panax ginseng, on changes of peripheral tissue blood flow in diseased model animals with vagotonic-type autonomic imbalance [SART (specific alternation of rhythm in temperature)-stressed (repeated cold-stressed) mice developed by us], and sympathicotonic-type stressed mice [restraint and water immersion-stressed (R WIS) mice], using the hydrogen clearance method. Decreases in gastric blood flow in both body and pyloric regions of the stomach and increases in dermal blood in both the shoulder and lumbar region in SART-stressed mice were prevented to a considerable extent by daily treatments with 20S-PG, 2.5-10 mg/kg/d. Similarly, the marked decrease in gastric blood flow following R WIS loading was significantly blocked by 10 mg/kg/d of 20S-PG. 20S-PG had a minor preventive effect on decreases in hepatic and dermal blood flow in R WIS mice. The preventive effect of 20S-PG on changes in tissue blood flow, recognized in model animals with autonomic imbalance not only in the vagotonic state but also in the sympathicotonic state, is therefore regarded with considerable interest and may provide a clue to explain the pharmacological action of ginseng.

Animals↗
PubMed1985

[A case of immature mediastinal teratoma].

A case of mediastinal immature teratoma was treated with a multimodality approach that included surgery, chemotherapy, and radiotherapy. Serum alpha-fetoprotein at admission was elevated and changed in parallel with the therapy and tumor growth. The patient died of sudden respiratory failure 18 months after admission. Mediastinal immature teratoma with elevated serum levels of alpha-fetoprotein carries a poor prognosis, as does endodermal sinus tumor. We concluded that this condition should most probably be treated with a combination of intensive chemotherapy, surgical resection, and radiotherapy.

Adolescent↗
PubMed1985

[Monitoring of follicles by ultrasonography during induction with HMG-HCG treatment--especially on the prevention of side effects].

Estrogen levels are a useful indicator to use in predicting of ovarian hyperstimulation syndrome (OHSS) which is one of the side effects of HMG-HCG therapy. However, the quantitative assay of estrogens entails cumbersome time-consuming procedures. The present study represents our attempt to establish criteria for predicting the occurrence of OHSS by the use of ultrasonography (USG), a diagnostic procedure that can be performed quickly and conveniently. The subjects were 40 anovulatory women (79 cycles) receiving HMG-HCG therapy. Each patient had USG performed at the time of switching to HCG in a regimen of sequentially administered gonadotropins and was measured for maximum follicular diameter (FD) and total of vertical follicular area (FA) to correlate measurements of these parameters with simultaneously determined serum estradiol (E2) levels. A study was also made of relationships of FD and FA with ovulation and OHSS. The results are summarized as follows: No distinct correlation was observed between FD and E2 (r = 0.3794). It should be noted, however, that the therapy was successful in inducing ovulation in those cases in which the patient was switched to HCG from HMG when FD was 18mm or above. There was a significant correlation between FA and E2 (r = 0.8113, p less than 0.001). FA was thus proven to well reflect E2 levels and hence to be a parameter of the predictive value for OHSS. All but one (with moderate OHSS) of 26 cases showing evidence of OHSS had FA values of more than 6.0cm2, while those developing severe OHSS invariably.(ABSTRACT TRUNCATED AT 250 WORDS)

Amenorrhea↗
PubMed1985

Synthesis of branched ribonucleotides.

A synthetic strategy for branched ribonucleotides, which have recently been discovered, was described. A fully protected adenosine unit (5) having the tris (4,5-dichlorophthalimido)trityl (CPTr), bis(anilino)phosphoryl (BAP), and bis(phenylthio)phosphoryl (BPTP) groups as the 5'-, 2'-, and 3'-hydroxyl protecting groups, respectively, was synthesized from adenosine by a five-step reaction involving a new method for the 2'-O-phosphorylation by the use of hexaethylphosphorous triamide. The selective deprotection of appropriate protecting groups from 5 followed by stepwise condensation with two different ribonucleoside derivatives (7 and 10) gave a protected branched ribonucleotide (11) via a 3'-phosphorylated 2'-5' dinucleotide (8). Deprotection of 11 and 8 gave a branched trinucleotide (12) and 3'-phosphorylated dinucleotide (13).

Adenosine↗
PubMed1985

Chemical synthesis of capped RNA fragments and their ability to complex with eukaryotic ribosomes.

In other to examine the binding ability of the 5'-terminal part of eukaryotic mRNA to 80S ribosome, several kinds of oligoribonucleotides, pA-U-G, m7G5'pppA-U-G, m7G5'pppG-U, m7G5'pppA-U-G-A-C-C, were synthesized chemically. The binding experiments of oligonucleotides to 80S ribosome showed that the capped structure as well as AUG are essential for ribosome binding, and the efficiency is enhanced by the 5'-leader sequence if it would include complementary sequence to the 3'-terminal part of 18S rRNA.

Base Sequence↗
PubMed1984

Cyclic diacyl groups for protection of the N6-amino group of deoxyadenosine in oligodeoxynucleotide synthesis.

Three kinds of substituted phthaloyl groups and a succinyl group were introduced onto the N6-amino function of deoxyadenosine derivatives. Among them, the succinyl group was found to be the most effective for prevention of depurination upon detritylation in acidic media and the most stable in basic media. Protection of the N6-amino function of 5'-O-dimethoxytrityldeoxyadenosine and introduction of a succinate linker into the 3'-hydroxyl were achieved simultaneously by a one-step reaction with succinic anhydride. A tetradeoxyribonucleotide, dTpTpTpA containing a 3'-terminal deoxyadenosine was successfully synthesized on a polystyrene support via the phosphotriester method.

Acylation↗
PubMed1984

Chemical synthesis of the 5'-terminal part bearing cap structure of messenger RNA of cytoplasmic polyhedrosis virus (CPV): m7G5'pppAmpG and m7G5'pppAmpGpU.

The 5'-terminal structures of mRNA bearing the so-called 'cap' from cytoplasmic polyhedrosis virus (CPV), m7G5' pppAmpG and m7G5' pppAmpGpU, were first chemically synthesized. S,S-Di(4-methoxyphenyl) N6-benzoyl-2'-O-methyladenosine 5'-phosphorodithioate ((ArS) 2pAbmz) was prepared by phosphorylation of the 5'-hydroxyl group of N6-benzoyl-2'-O-methyladenosine with S,S-di(4-methoxyphenyl) phosphorodithioate by TPS. By the triester approach using (ArS) 2pAbmz as starting material, the protected dinucleotide and trinucleotide bearing 5'-phosphate group were synthesized. The protective groups of the dinucleotide and trinucleotide were removed to obtain pAmpG and pAmpGpU, respectively. By the reaction of a capping agent ((PhS) ppm7G) with pAmpG and pAmpGpU in the presence of silver nitrate or iodine. The 5'-terminal structure of the messenger RNA strand of CPV which was labelled isotopically, was confirmed completely as m7G5' pppAmGpU by cochromatography with the materials chemically synthesized here.

Chemical Phenomena↗
PubMed1984

Subcellular distribution of viral structural proteins during simian virus 40 infection.

The amounts of simian virus 40 structural polypeptides Vp1, Vp2, and Vp3 in different subcellular fractions at various times after lytic infection were determined by a quantitative immunoblotting procedure. Simian virus 40-infected cells were lysed with a buffer containing Nonidet P-40 to yield a soluble fraction. The Nonidet P-40-insoluble fraction was further fractionated in the presence of deoxycholate and Tween 40 to yield a soluble fraction (cytoskeletal) and an insoluble fraction (Nuc), which is primarily cell nuclei. At 33 h postinfection, the majority of viral structural proteins was found in the cell nucleus, whereas, at 48 to 65 h postinfection, Vp1 was distributed evenly among all cell fractions and Vp2 and Vp3 were found predominantly in the cytoskeletal and Nuc fractions. Thus, not all of the viral polypeptides synthesized in the cytoplasm migrated into the cell nucleus. Throughout infection, the molar ratio (Vp3/Vp2) was rather constant in all subcellular fractions, indicating that the synthesis or processing or both of Vp2 and Vp3 are coordinately regulated. The molar ratio of Vp1/(Vp2 + Vp3) varied among the fractions. The Vp1/(Vp2 + Vp3) molar ratio in the soluble fraction varied during the course of infection; however, constant ratios were maintained in the cytoskeletal and Nuc fractions. Thus, the mechanism which controls the movement of Vp1 to different compartments of the cell appears to be different from that of Vp2 and Vp3. The Vp1/(Vp2 + Vp3) value in the Nuc fraction was similar to the ratio found in virus particles. The constant molar distribution of Vp1, Vp2, and Vp3 in the Nuc fraction throughout infection suggests that there is a specific mechanism which regulates the transport of viral structural proteins. These results support the hypothesis that the structural proteins of simian virus 40 are transported into the cell nucleus in precise proportions.

Animals↗
PubMed1984

Steroidogenic properties of a new aldosterone-stimulating factor: interaction with angiotensin II and adrenocorticotropin during variations of dietary sodium.

We investigated the in vitro steroidogenic activity of a new aldosterone-stimulating factor (ASF). Aldosterone responses of adrenal zona glomerulosa cells to ASF were assessed in response to variations in sodium intake and during incubation with either ACTH or angiotensin II (AII). Studies were performed in collagenase-dispersed adrenal capsular cells harvested from male New Zealand White rabbits that were on either regular or low sodium diets for 7-10 days. ASF, AII, and ACTH produced dose-dependent increases in aldosterone production. In cells from sodium-replete rabbits, the concentrations required to elicit the half-maximum response (ED50) were 2.2 +/- 0.3 (+/-SE) X 10(-11), 7.2 +/- 1.1 X 10(-10), and 3.4 +/- 0.5 X 10(-8) M for ACTH, AII, and ASF, respectively. Sodium depletion increased maximal responses but not sensitivity to AII and ACTH; responses to ASF were essentially unchanged. Large concentrations of ASF (10(-7) M) potentiated AII-induced aldosterone responses of adrenal capsular cells from sodium-depleted, but not sodium-replete, rabbits. In marked contrast, similar concentrations of ASF inhibited ACTH-induced aldosterone production of adrenal capsular cells from both sodium-replete and sodium-depleted rabbits. It is concluded that ASF has its own intrinsic steroidogenic activity. Furthermore, although large concentrations of ASF potentiate AII responses in sodium-depleted animals, ASF inhibits the aldosterone-stimulating activity of ACTH in both sodium-replete and sodium-depleted animals.

Adrenocorticotropic Hormone↗
PubMed1984

[Abnormal ECG and adrenaline-induced arrhythmias in restraint and water immersion stressed mice and effects of oxprenolol].

Male ddY mice were loaded with restraint and water immersion stress (RWIS) for 1 hr, and their ECG was measured by lead II. A considerable decrease of heart rate and remarkable prolongations of PQ, QT and QRS intervals were observed in the ECG of RWIS mice. Then experimental arrhythmias were induced by methacholine or adrenaline (Adr) on RWIS mice, and their frequencies of appearance were examined. The appearances of methacholine-induced ventricular extrasystole, atrio-ventricular (A-V) block, sino-atrial (S-A) block and sinus standstill were higher in RWIS mice than in normal mice, and the appearances of sinus arrhythmia and supraventricular extrasystole were similar to normal mice. The appearance of Adr-induced arrhythmia of any type was significantly higher in RWIS mice than in normal mice. Then protective effects of 3 beta-blockers, oxprenolol, propranolol and carteolol, on the worsening of Adr-induced arrhythmias on RWIS mice were studied. A single administration of 5 or 10 mg/kg of oxprenolol or 5 mg/kg of propranolol inhibited the appearance of extrasystole and A-V block. The effectiveness of three-times administrations of 1 approximately 10 mg/kg of oxprenolol was similar to that of the single administration. These results suggest that oxprenolol shows a strong antiarrhythmic effect by continuous administrations on chronic syndromes in SART mice, and it shows an immediate effect by a single administration on acute syndromes in RWIS mice.

Acute Disease↗
PubMed1984

Toxicological studies on a new macrolide antibiotic, midecamycin acetate (miocamycin). Part VI-1. Acute toxicity in infant mice in comparison with young adult mice.

Sutherland and Weiss et al. reported cases of newborn human deaths or Gray syndrome after overdosage of chloramphenicol. In general, it has been reported that the acute toxicities of drugs are enhanced in immature animals compared with adult animals. The objective of this study was to determine the LD50 values in infant (5-day-old) and young adult (5-week-old) male and female mice after single subcutaneous and oral administration of MOM, non-crystalline solid and to estimate the toxicity ratio of those LD50 values. LD50 values of MOM, non-crystalline solid, were more than 5,000 mg/kg and the lethal toxicity was the same in infant and adult mice. Toxicity ratios were not obtained.

Age Factors↗
PubMed1984

Toxicological studies on a new macrolide antibiotic, midecamycin acetate (miocamycin). Part VI-2. Acute toxicity in infant rats in comparison with young adult rats.

In the present acute toxicity studies on MOM, non-crystalline solid, with infant male and female rats (5-day-old) and young adult male and female rats (5-week-old), it is confirmed as follows: LD50 values were estimated more than 5,000 mg/kg in both cases of subcutaneous and oral administrations. MOM, non-crystalline solid, did not exhibit any toxic effects similarly as previously reported with infant male and female mice and young adult male and female mice. There might be no definite age difference in toxicity between young and adult rats as LD50 values were estimated more than 5,000 mg/kg in independence upon the age. There might be no definite species difference in toxicity between mice and rats.

Age Factors↗