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Biomedical subjects

T Tsuchiya

Publications and source records attributed to T Tsuchiya.

At least 361 records · Page 20Linked to original sources
PubMed1994

Lithium toxicity and Na+(Li+)/H+ antiporter in Escherichia coli.

The lithium ion (Li+) shows toxicity against Escherichia coli cells when present in a high concentration in the environment. Since Li+ is extruded from cells via a Na+(Li+)/H+ antiporter, this antiporter must be involved in the detoxification of Li+. Two Na+(Li+)/H+ antiporters (NhaA system and NhaB system) are known to be present in E. coli. We investigated the properties of the antiporters and the participation of these systems in the detoxification of Li+ using mutants lacking one of the antiporters, or lacking both of them. Although the affinity for Li+ of the two systems was almost the same, the Vmax value for Li+ transport of the NhaA system was about 12 times larger than that of the NhaB system. Wild type cells were unable to grow in the presence of 0.7 M LiCl. Although a wild type cell and a mutant lacking the NhaB system grew in the presence of 0.6 M LiCl, a mutant lacking the NhaA system did not. This second mutant grew in the presence of 0.1 to 0.2 M LiCl. A mutant lacking both the NhaA and NhaB systems could not grow in the presence of 30 mM LiCl.

Escherichia coli↗
PubMed1994

Characterization of the lactose transport system in Citrobacter freundii.

The lactose transport system of Citrobacter freundii was characterized. Both the lactose transport system and beta-galactosidase were induced with either lactose or isopropyl-beta-D-thiogalactopyranoside (IPTG), the latter being the better inducer. The Km values for methyl-beta-D-thiogalactopyranoside (TMG) transport and lactose transport were 0.61 mM and 1.1 mM, respectively, and the Vmax values were 53 nmol/min/mg cell protein and 12 nmol/min/mg cell protein, respectively. Thus, TMG is a better substrate than lactose. Thiogalactopyranoside (TDG) was a very potent competitive inhibitor. Neither Na+ nor Li+ had a significant effect on the TMG transport or the lactose transport. Proton/substrate cotransport (symport) via this system was observed.

Citrobacter freundii↗
PubMed1994

The complete sequences of African horsesickness virus serotype 4 (vaccine strain) RNA segment 2 and 6 which encode outer capsid protein.

The complete sequences of RNA segment 2 and segment 6 of African horsesickness virus serotype 4 (AHSV-4) vaccine strain were determined from cDNA clones inserted into pBR 322. The RNAs of segment 2 and 6 are 3229, 1566 bp long respectively and both contain an open reading frame encoding proteins VP2 and VP5 of 1060, 505 amino acid residues. The estimated molecular weight of VP2 was 124,178 dalton and that of VP5 was 56,793 dalton. Their noncoding end sequences were 5'GTTTAA . . . and . . . ACATAC3' (segment 2), 5'GTTTAT . . . and . . . ACTTAC3' (segment 6). They were different from orbivirus characteristic terminal sequences, which were 5'GTTAAA . . . and . . . ACTTAC3'. The comparison of both sequences of AHSV-4 segment 2 and 6 with those of segment 2 and 5 of bluetongue virus (BTV) serotype 10 revealed 53% nucleotide similarity and 23% amino acid similarity (segment 2), and 58% nucleotide similarity and 46% amino acid similarity (segment 6). In the same way, the comparison of both sequences of the vaccine strain with those of the virulent strain segment 2 and segment 6 of AHSV-4 revealed 91% nucleotide and 96% amino acid similarity (segment 2), and 98% nucleotide and 98% amino acid similarity (segment 6).

African Horse Sickness Virus↗
PubMed1994

[Identification of Mycobacterium avium and Mycobacterium intracellulare using DNA probe test, and their ratio in Niigata area].

Using Gen-Probe test, both the Mycobacterium avium and Mycobacterium intracellulare strains were identified in the 76 disease-associated Mycobacterium-avium complex (MAC) strains isolated in the NIIGATA area. The following results were obtained: 1) Fifty-four MAC strains (71.1%) reacted with M. avium-probe and 22 strains (28.9%) reacted with M. intracellulare-probe. 2) There were no significant differences between the ratio of two strains before and after 1991. 3) The ratio of female cases with M. avium was significantly higher (22/32) in the later period (after 1991) than in the former period (9/22).

DNA Probes↗
PubMed1994

[A case of Jordans' anomaly].

A 35-years old female with Jordans' anomaly was reported. She had been treated for diabetes mellitus and hypertension at another hospital. She was admitted to our hospital for operation for diabetic retinopathy on July 9, 1992. Wright-Giemsa stained peripheral blood smear revealed multiple vacuoles in the cytoplasm of the granulocytes and monocytes. Histochemical studies of these vacuoles showed positive for Sudan III but negative for peroxidase, alkaline phosphatase and PAS staining. Electron microscopic examination revealed that lipid containing vacuoles had no clear membrane and were not associated with cell organelles. Laboratory findings of the serum showed hyperglycemia (FBS 188mg/dl), high HbA1c level (9.4%) and mild type IIa hyperlipidemia. Abdominal sonogram and abdominal CT showed no remarkable abnormalities except for mild fatty liver. Her elder sister and daughter had similar morphological findings in granulocytes, monocytes and lymphocytes.

Adult↗
PubMed1994

[Transfusion medicine].

It is important to establish educational system for every subjects of clinical pathology. In the transfusion medicine, in order to establish the GIO and SBO, a questionnaire survey on postgraduate education system was conducted on 98 institutes of laboratory medicine on university hospital and laboratories of hospital. As a results, over 50% of institutes are able to educate residents to these subjects (as SBOs). The most important need for clinical pathologists or laboratory physician to act a consultant for physicians about safety and effective transfusion medicine. Moreover, clinical pathologists has an ability to administer the department of transfusion.

Blood Transfusion↗
PubMed1994

[Bronchoscopic classification in sarcoidosis].

Retrospective analysis in sixty-six patients with pulmonary sarcoidosis: thirty-two males and thirty-four females according to bronchoscopic finding was performed and classified five types in patients with sarcoidosis. Type 1: normal findings. Type 2: prominent vascular change of the mucosa, beyond the bronchial cartilage ring. Type 2 was further divided into two subtypes. 2a: simple increase vascularity. (mucosal vessels run parallel to cricoid cartilage. 2b: irregular vessels. Type 3: sarcoido nodular lesions. Type 4: plaque present. Type 5: deformity of bronchial walls. Eleven type 1 cases were observed (16.7%), and forty-two type 2 cases, including twenty-two type 2a cases (33.3%), twenty type 2b cases (30.3%), There were nineteen type 3 cases observed (28.8%), seven type 4 cases (10.6%), and seven type 5 cases (10.6%).

Adult↗
PubMed1994

[Effects of cutaneous mechanical stimulation on plasma corticosterone, luteinizing hormone (LH), and testosterone levels in anesthetized male rats].

Effects of cutaneous mechanical stimulation on plasma corticosterone, luteinizing hormone (LH), and testosterone levels were examined in young adult (13-22 weeks old) and aged (24-27 months old) male Wistar rats anesthetized with pentobarbital. Under the resting condition without somatic sensory stimulation, neither plasma corticosterone measured every 15 min between 1430 h and 1630 h nor plasma LH and testosterone measured every 30 min between 1400 h and 1730 h revealed any significant fluctuations. Nociceptive mechanical stimulation of both hindpaws by pinching for 10 min significantly increased plasma corticosterone, LH, and testosterone, in young adult rats. Plasma corticosterone was increased for one hour following the stimulation. On the other hand, plasma LH was increased 30 and 60 min after the cessation of stimulation, while plasma testosterone was increased 60-150 min after stimulation. However, innocuous mechanical stimulation of both hindlimbs by brushing for 10 min did not significantly change either plasma corticosterone, LH, or testosterone. These findings indicate that, nociceptive information from skin lead to the increased secretion of corticosterone from the adrenal cortex and the increased secretion of LH from the anterior pituitary, resulting in an increase in testosterone secretion from the testes into the plasma, after emotional factors are eliminated by anesthetizing the subjects. In aged rats, the same nociceptive mechanical stimulation by pinching significantly increased the plasma corticosterone levels. The magnitude and time-course of the response in aged rats were equivalent to those in young adult rats. On the other hand, in aged rats, neither plasma LH nor testosterone levels were changed by the same nociceptive mechanical stimulation. This is in sharp contrast to the increase in both plasma LH and testosterone caused by the stimulation of young adult rats. These findings indicate a functional dissociation induced by aging between the secretory responses of the anterior pituitary, testes on the one hand and the adrenal cortex on the other hand, to nociceptive somatic sensory stimulation. Aging does not alter corticosterone release from the adrenal cortex to nociceptive somatic sensory stimulation, but LH secretion from the anterior pituitary and testosterone secretion from the testes to nociceptive somatic sensory stimulation are subject to dysfunction with aging.

Aging↗
PubMed1993

Spatial resolution of fodrin proteolysis in postischemic brain.

One of the major obstacles in investigating in vivo proteolytic phenomena has been the inaccessibility to spatial information as to where in the tissue the reaction proceeds because the orthodox method employing electrophoretic analysis requires homogenization of samples and thus results in loss of such spatial information. To overcome this technical drawback, we have developed methodology to produce antibodies that specifically distinguish a proteolyzed form of a given protein from its intact form. Here we describe our immunohistochemical observation of calpain-catalyzed fodrin proteolysis in postischemic gerbil hippocampus, using an antibody exclusively specific to the proteolyzed 150-kDa form of fodrin alpha subunit. Our data establish a novel discovery that transient (10 min) global forebrain ischemia followed by reperfusion induces at least two distinct phases of fodrin proteolysis in hippocampus: an early phase in molecular layer and in stratum oriens of CA3 and CA1 sectors within 15 min and a late drastic and persistent phase in the entire CA1 after 4-24 h. The former may be one of the early events initiating the complex cascade leading to the delayed neuronal death, while the latter should be considered as a more direct cause for the actual degeneration in CA1.

Animals↗
PubMed1993

Study on fluorination-toxicity relationships. Syntheses of 1-N-[(2R,3R)- and (2R,3S)-4-amino-3-fluoro-2-hydroxybutanoyl] derivatives of kanamycins.

(2R,3R)- And (2R,3S)-4-azido-3-fluoro-2-hydroxybutanoic acids (11 and 22) have been prepared from 3-deoxy-3-fluoro-1,2-O-isopropylidene-alpha-D-glucofuranose (1) and 3,5-di-O-benzyl-1,2-O-isopropylidene-alpha-D-xylofuranose (12), respectively. They were then coupled to the N2N-1 group of suitably protected kanamycin A or kanamycin B analogs to give, 1-N-[(2R,3R)- and (2R,3S)-4-amino-3-fluoro-2-hydroxybutanoyl]kanamycins (32-35). This group of compounds (32-34) exhibited similar antibacterial activity and toxicity level as those of the corresponding 1-N-[(S)-4-amino-2-hydroxybutanoyl] (AHB) derivatives of kanamycins. The base strength of the H2N-4"' group of 32 and 34, as determined by 13C NMR spectroscopy (in D2O) at varying pD values, was found to be lower when compared to the basicity for the corresponding AHB analogs. The relationship between observed toxicity and base strength of the H2N-4"' group is discussed.

Anti-Bacterial Agents↗
PubMed1993

[Relationship between cigarette smoking and physical complaints].

In order to evaluate the influence of cigarette smoking on health conditions, the authors analyzed results of the THI (Todai Health Index) questionnaire, which was administered to male employees of a large-sized enterprise in Osaka between 1984 and 1990. The smoking rate of male employees decreased over this period of time from 62.4% (1984) to 58.3% (1990) in this enterprise. Complaints regarding "respiratory organ", "digestive organ", "circulatory organ", "irregularity of daily life", "impulsiveness", and "many subjective symptoms" significantly increased with the amount of smoking. Many items of physical complaints in the THI questionnaire were also associated with smoking. These were coughing, sore throat, sputum, nausea when brushing teeth, loss of appetite, stomach pain, stomach problems, diarrhea, heartburn, gum problems, bad breath, heavy eyelids, itchy skin, face looked pale, shortness of breath, palpitation, feeling flushed or feverish, back pain, going to bed late and getting up late, weakness or fatigue, irregular meals, irritation, sensitive or nervous, eating salty or greasy food, and heavy drinker. It is therefore important in the health education of individual smokers to put special emphasis not only on the many diseases associated with smoking but also these physical complaints.

Adolescent↗
PubMed1993

Effects of naftidrofuryl oxalate on microsphere embolism-induced changes in tricarboxylic acid cycle intermediates of rats.

The present study was undertaken to determine whether naftidrofuryl oxalate, a cerebral vasodilator, may improve or attenuate microsphere embolism-induced damage to the mitochondrial tricarboxylic acid cycle. For this purpose, the intermediates in the tricarboxylic acid cycle were determined using cerebral cortex isolated from microsphere-injected rats with and without naftidrofuryl oxalate treatment. Seven-hundred microspheres, with a diameter of 48 microns were injected into the right hemisphere through the right common carotid artery. The presence of cerebral infarction on the 3rd day after the operation was confirmed by the development of triphenyltetrazolium chloride-unstained areas in brain sections. Succinate, fumarate, malate, citrate and alpha-ketoglutarate, but not oxaloacetate, contents were significantly decreased in the right hemisphere of rats on the 3rd day following microsphere embolism. In the left hemisphere, a similar but smaller decrease in these intermediates was seen. The rats, which showed typical stroke-like symptoms, were treated with 15 mg/kg naftidrofuryl oxalate i.p., twice daily for 2.5 days, resulting in a significant reversal of the intermediate content of both hemispheres toward the control and an increased in the triphenyltetrazolium-stained area of a coronal section of the right hemisphere relative to the untreated animals. The results suggest that naftidrofuryl oxalate attenuates the development of microsphere embolism-induced cerebral infarction and improves microsphere-induced impairment of the mitochondrial tricarboxylic acid cycle. The observed effects provided evidence for a possible site of action of the agent on ischemic brain energy metabolism.

Animals↗
PubMed1993

Synthesis of 5-deoxy-5-fluoro- and 5-deoxy-5,5-difluoro-netilmicin.

5-Deoxy-5-fluoro- (9) and 5-deoxy-5,5-difluoro-netilmicin (27) have been prepared from the corresponding 5-epi and 5-oxo derivatives of netilmicin by treatment with DAST. Structures of the fluorinated by-products (10, 11, and 12) obtained in one of the synthesis of 9 were determined. 5-Epi-netilmicin (13) and 5-epi-6'-N-methyl-netilmicin (21) have also been prepared.

Animals↗