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Biomedical subjects

M Tsuda

Publications and source records attributed to M Tsuda.

At least 361 records · Page 20Linked to original sources
PubMed1992

[In vitro susceptibilities of Mycobacterium avium and Mycobacterium intracellulare to new macrolides, new quinolones, and antituberculous drugs on Dubos agar medium].

Mycobacterium avium and M. intracellulare were isolated from the sputum of patients infected with atypical mycobacteria using 1% Ogawa medium and identified by the DNA probe test. Then the MICs of various kinds of drugs against these mycobacterial species were determined on Dubos agar medium, and the drug susceptibilities were also determined on 1% Ogawa medium in parallel. The drugs tested were new macrolides, such as clarithromycin (CAM) and roxithromycin (RXM), new quinolones, such as ofloxacin (OFLX) and ciprofloxacin (CPFX), and antituberculous drugs, such as isoniazid (INH), rifampicin (PFP), streptomycin (SM), and ethambutol (EB). The MICs of the drugs tested, especially those of CAM, OFLX, and RFP, when determined on Dubos agar medium, were generally lower against M. intracellulare than against M. avium. The susceptibilities of the mycobacterial isolates tested to RFP and SM determined on Dubos agar medium were markedly different from those determined on 1% Ogawa medium. Such discrepancies may be accounted for by absorption of these drugs to the egg medium and instability of RFP in the egg medium. Overall, our results indicate that the new macrolides and new quinolones are effective against atypical mycobacteria.

4-Quinolones↗
PubMed1992

Natural evacuation versus irrigation.

The comparison of the influences of the natural evacuation method and the colostomy irrigation method on complaints, daily activities and psychosocial conditions revealed that colostomy irrigation, as compared to natural evacuation, imposes less distress on the patient, causes fewer skin problems and is less of a financial burden. In daily activities, irrigation causes fewer difficulties in comparison to natural evacuation in the areas of bathing and sleeping. Furthermore, the frequency of going outdoors remains at the same level as in pre-operative days and the patients are able to adjust to daily activities post-operatively. By comparing irrigation patients and natural evacuation patients from a psychosocial standpoint, irrigation patients hold a higher degree of self-esteem, have fewer anxieties and fewer worries than those using natural evacuation. The instruction of evacuation control, management of gas odor, and a great deal of psychosocial support needs to be given to natural evacuation patients.

Activities of Daily Living↗
PubMed1991

A novel mechanism of cation/substrate cotransport: Na+/H+/adenosine cotransport in Vibrio parahaemolyticus.

Adenosine is actively transported with Na+ in Vibrio parahaemolyticus (Sakai, Y., Tsuda, M., Tsuchiya, T. (1987) Biochim, Biophys. Acta 893, 43-48). The proton conductor carbonylcyanide m-chlorophenylhydrazone, CCCP, strongly inhibited active transport of adenosine at pH 8.5 as well as at pH 7.0. This seemed peculiar because the driving force, an electrochemical potential of Na+, is established by the Na(+)-extruding respiratory chain at pH 8.5 in this organism, although it is established by the function of the Na+/H+ antiporter at pH 7.0. This suggested that H+ might be involved in the adenosine transport. We detected H+ uptake induced by adenosine influx in V. parahaemolyticus cells in the presence of Na+, but not in its absence, suggesting the occurrence of Na+/H+/adenosine cotransport. We isolated formycin A-resistant mutants which showed defective adenosine transport. The mutation resulted in simultaneous losses of Na+ uptake and H+ uptake induced by adenosine. In revertants from these mutants the Na+ uptake and H+ uptake were restored simultaneously. The frequencies of reversion were in the order of 10(-7), indicating that the mutations were single mutations; namely that Na+/adenosine cotransport and H+/adenosine cotransport took place via the same carrier. Thus, we conclude that adenosine is transported by the novel mechanism of Na+/H+/adenosine cotransport in V. parahaemolyticus.

Adenosine↗
PubMed1991

Na(+)-coupled ATP synthesis in a mutant of Vibrio parahaemolyticus lacking H(+)-translocating ATPase activity.

An H(+)-translocating ATPase-defective mutant of Vibrio parahaemolyticus YS-1 grew well on lactate as a sole source of carbon at pH 8.5 under aerobic conditions, but not under anaerobic conditions. Both wild type cells and the mutant cells could grow on lactate at pH 8.5 even in the presence of an H+ conductor, carbonylcyanide m-chlorophenylhydrazone (CCCP), but not at pH 7.5. Oxidative phosphorylation resistant to CCCP in the mutant occurred at pH 8.5. These findings suggest the existence of Na(+)-coupled oxidative phosphorylation which is functional at alkaline pHs in V. parahaemolyticus. In fact, we observed ATP synthesis driven by an artificially imposed Na+ gradient in YS-1 cells, which was resistant to CCCP.

Adenosine Triphosphate↗
PubMed1991

Developmentally and regionally regulated alterations of octamer- and GC-box-binding activities during the postnatal development of mouse cerebellum.

Gel-mobility analyses using a DNA probe containing the SV40 enhancer-promoter revealed that the DNA-binding activities of cerebellar extracts changed drastically during the postnatal development of mouse brain. Three major DNA-protein complexes formed on the 72-bp enhancer (complexes E-I, E-II and E-III) were detected in the extracts prepared from the 2- and 10-day-old mouse cerebellum, but two of them (complexes E-II and E-III) were not detected in 3- and 7-week-old mice. In contrast, the formation of the complexes E-II and E-III, but not E-I, was observed in the cerebral cortex extracts throughout postnatal development until at least 7 weeks after birth. The addition of the octamer motif as a competitor abolished the formation of these three complexes. On the other hand, the formation of DNA-protein complexes on the 21-bp promoter by the cerebellar extracts increased after birth, while this increase in the formation of the complexes was not detected in the cerebral cortex extracts. This complex formation was found to be dependent upon the GC-box and to be stimulated by the addition of Zn2+, indicating that the protein binding to the 21-bp promoter may contain intramolecular zinc fingers. Thus, the expression of the octamer- and the GC-box-binding proteins are developmentally and regionally controlled in the cerebellum during the postnatal development of the mouse brain.

Animals↗
PubMed1991

The mouse S-antigen gene. Comparison with human and Drosophila.

We have characterized a gene for mouse S-antigen and compared its sequence with that of corresponding human and two recently published Drosophila S-antigen genes. The mouse S-antigen gene was approximately 50 kbp in length and consisted of 16 exons and 15 introns. The length of most exons was less than 100 bp and the smallest one was only 10 bp. In contrast, the length of most introns was larger than 2 kbp and the gene consisted of 97% intron and 3% exon. Both splice sites for donor and accepter were in good agreement with the GT/AG rule. S-antigen genes in human and mouse were highly conserved. In contrast, genes for the Drosophila 49-kDa arrestin homolog and arrestin consist of three introns and four exons and two introns and three exons, respectively. The 5'-flanking region of the mouse S-antigen gene, approximately 1.0 kbp long, had no regulatory elements for transcription such as the TATA, CAAT and GC boxes, while a Drosophila arrestin gene has TATA and CAAT boxes. Interestingly, the 5'-flanking region of the mouse gene had promoter activity in an in vitro transcription assay using a nuclear extract of rat brain. A major transcription start site was found at 387 bp upstream from the translation start codon ATG in mouse. From our results, and those of others, we suggest that the S-antigen gene has evolved from a common ancestor gene by either insertion or deletion of introns. Such an alteration of gene structure may have played a role in the evolution of the S-antigen.

Amino Acid Sequence↗
PubMed1991

Expression of S-antigen in retina, pineal gland, lens, and brain is directed by 5'-flanking sequences.

S-antigen (S-Ag) is an abundant protein of the retina and pineal gland that elicits experimental autoimmune uveitis and pinealocytis in several animal species. To study the elements regulating the expression of S-Ag, we generated transgenic mice expressing the chloramphenicol acetyl transferase (CAT) gene under the control of a 1.3-kilobase pair 5'-flanking segment of the mouse S-Ag gene. While all of the transgenic mice expressed CAT activity in the retina, in some animals CAT activity was also detected in the pineal gland, lens, and brain. Immunoblotting, polymerase chain reaction-mediated detection of RNA, and immunocyto-staining of transgenic tissues with antibodies to CAT and S-Ag established that the profile of expression of the transgene corresponded to that of S-Ag; both proteins were detectable in retinal photoreceptor cells, pinealocytes, lens fiber and epithelial cells, the cerebellum, and the cerebral cortex. These results indicate that S-Ag is expressed in a wider spectrum of the cell types than previously recognized and that a 1.3-kilobase pair S-Ag promoter segment contains sufficient information to direct appropriate tissue-specific gene expression in transgenic mice.

Animals↗
PubMed1991

Autoradiographic distribution of pituitary adenylate cyclase activating polypeptide (PACAP) binding sites in the rat brain.

Distribution of pituitary adenylate cyclase activating polypeptide (PACAP) binding sites was investigated in the rat brain and pituitary gland by means of in vitro autoradiography. High densities of specific [125I]PACAP binding were observed in the anterior pituitary, hippocampus (CA1-4 and dentate gyrus) and in the superior colliculus. Moderate to high labeling was observed in the periaqueductal gray matter, substantia nigra pars compacta, and in the habenula. The hypothalamus, thalamus, ventral tegmental area (VTA), mammillary body and medial geniculate body were moderately labeled. The present results support possible actions of PACAP on the pituitary functions, and further suggest that PACAP is a neurotransmitter/neuromodulator in the central nervous system.

Animals↗
PubMed1991

Resonance Raman studies of the HOOP modes in octopus bathorhodopsin with deuterium-labeled retinal chromophores.

Resonance Raman spectra of the hydrogen out-of-plane (HOOP) vibrational modes in the retinal chromophore of octopus bathorhodopsin with deuterium label(s) along the polyene chain have been obtained. In clear contrast with bovine bathorhodopsin's HOOP modes, there are only two major HOOP bands at 887 and 940 cm-1 for octopus bathorhodopsin. On the basis of their isotopic shifts upon deuterium labeling, we have assigned the band at 887 cm-1 to C10H and C14H HOOP modes, and the band at 940 cm-1 to C11H = C12H Au-like HOOP mode. Except for a 26 cm-1 downward shift, the C11H = C12H Au-like wag appears to be little disturbed in octopus bathorhodopsin from the chromophore in solution since its changes upon deuterium labeling are close to those found in solution model-compound studies. We found also that the C10H and C14H HOOP wags are also similar to those in the model-compound studies. However, we have found that the interaction between the C7H and C8H HOOP internal coordinates of the chromophore in octopus bathorhodopsin is different from that of the chromophore in solution. The intensity of the C11H = C12H and the other HOOP modes suggests that the chromophore of octopus bathorhodopsin is somewhat torsionally distorted from a planar trans geometry. Importantly, a twist about C11 = C12 double bond is inferred. Such a twist breaks the local symmetry, resulting in the observation of the normally Raman-forbidden C11H = C12H Au-like HOOP mode. The twisted nature of the chromophore, semiquantitatively discussed here, likely affects the lambda max of the chromophore and its enthalpy.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Morphology of neurites from N18TG2 cell induced by protein kinase inhibitor H-7 and by cAMP.

Protein kinase inhibitor H-7 and dibutyryl (dB)-cAMP were found to induce neuritic processes in mouse neuroblastoma N18TG2 cells (36). In the present study, morphological differences between the neurites induced by H-7 and those by dB-cAMP were examined using electron microscopy (TEM and SEM) and tubulin immunohistochemistry. It was observed that: 1) The neurites induced by H-7 were relatively thin and frequently had varicosities. On the other hand, the neurites induced by dB-cAMP were thick but they had few varicosities. 2) Centrioles were frequently observed in the cells treated with dB-cAMP but were not encountered in the H-7-treated cells. 3) TEM and tubulin immunohistochemistry revealed that the main shafts of the neurites induced either by H-7 or dB-cAMP were filled with microtubules, but that the varicosities induced by H-7 contained a smaller amount of microtubules. 4) The stability to colchicine was greater in the neurites induced by H-7 than in those by dB-cAMP. From these features of the neurites, it was inferred that neurite outgrowth induced by dB-cAMP is deeply related to the formation of microtubules and that the neurites induced by H-7 were involved in other processes probably including an adhesive property of cell surfaces.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1991

New perylenequinones from Shiraia bambusicola.

Two new perylenequinones, named hypocrellin B and C, together with the known hypocrellin A were isolated from the stromatal tissues of Shiraia bambusicola. The structures of these compounds, including the absolute stereochemistry, were determined.

Ascomycota↗
PubMed1991

Management of congenital diaphragmatic hernia by extracorporeal membrane oxygenation (ECMO).

The purpose of this study was to evaluate the efficacy of extracorporeal membrane oxygenation (ECMO) for patients with congenital diaphragmatic hernia (CDH). Ten patients whose mortality was predicted to be more than 80% with previous therapeutics, were selected to use ECMO over the past five years. Patients were placed on ECMO by cannulating the right jugular vein and the right carotid artery. ECMO was started at 34.3 hours after birth on an average, and the average time on ECMO was 96.3 hours. Seven patients (70%) survived, and six out of them are in good health without any sequelae. In particular, all five patients whose pathological condition needing ECMO was persistent fetal circulation (PFC), survived. Therefore we believe ECMO is highly beneficial to overcome the condition of PFC. The survival rate of CDH patients under 24 hours of age in our hospital is 76.2% (16/21 cases) over the last 5 years, and it has improved compared with 57.1% (12/21 cases) before then. The fact that some of the critical patients who were lethal with conventional management, have been successfully treated by ECMO, played a great role in this improvement.

Child Development↗
PubMed1991

L-arginine-dependent formation of N-nitrosamines by the cytosol of macrophages activated with lipopolysaccharide and interferon-gamma.

The cytosol fraction of J774-1 murine macrophages activated with lipopolysaccharide (LPS) + interferon-gamma (IFN-gamma) was found to nitrosate a wide range of secondary and tertiary amines. The reaction was dependent on L-arginine and NADPH. The optimal pH for nitrosation was 7.2-7.3. Nitrosation was inhibited by arginine derivatives such as NG-monomethyl-L-arginine and NG-nitro-L-arginine, well-known inhibitors of nitric oxide (NO) synthase. These results indicate that nitrosation is mediated by NO synthase, which catalyzes formation of NO and L-citrulline from L-arginine. Nitrosamine formation also required oxygen and was inversely correlated with the basicity of nitrosatable amines. The nitrosation was inhibited by oxyhemoglobin, an NO trapping agent, and enhanced by superoxide dismutase, which stabilizes NO. LPS + IFN-gamma induced approximately 500-600 times greater nitrosation activity than that of non-activated macrophages. Macrophages treated with LPS alone exhibited 3-4 times greater nitrosation activity than untreated macrophages, whereas macrophages treated with IFN-gamma alone did not show enhanced nitrosation activity. A combination of the cytosols from macrophages treated with LPS alone and IFN-gamma alone did not nitrosate morpholine as rapidly as the cytosol of macrophages treated with both compounds together. The activity for forming L-citrulline and nitrite/nitrate from L-arginine was markedly induced by treatment with either LPS alone or LPS + IFN-gamma but not with IFN-gamma. Those results suggest that some other factor(s) in addition to NO synthase is involved for efficient nitrosation by the macrophage cytosol. This factor(s) was not induced in macrophages by either LPS- or IFN-gamma alone, but was induced only in the presence of the two compounds.

Amino Acid Oxidoreductases↗
PubMed1991

Sequence analysis of nutA gene encoding membrane-bound Cl(-)-dependent 5'-nucleotidase of Vibrio parahaemolyticus.

The membrane-bound 5'-nucleotidase of Vibrio parahaemolyticus is unique in requiring Cl- for activity. We cloned the nutA gene encoding the 5'-nucleotidase and sequenced it. It contained an open reading frame consisting of 1,680 nucleotides capable of encoding a protein of 560 amino acid residues. The first 21 amino acid residues of the N-terminal portion of this protein seem to be a signal peptide. The rest of the polypeptide (539 residues) is hydrophilic, and its molecular weight was calculated to be 60,008, which is in good agreement with the value of 63 kDa determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis for the 5'-nucleotidase derived from the cloned nutA gene. We tried to determine the amino acid sequence of the N-terminal portion of the purified enzyme. However, the N-terminal residue seemed to be blocked. As this 5'-nucleotidase can be solubilized from membrane vesicles with detergent, it may be a lipoprotein. The amino acid sequence around the possible cleavage site of the 5'-nucleotidase had homology with the sequences of the cleavage sites of the lipoproteins of Escherichia coli and other bacteria. The amino acid sequence had high (about 60%) homology with the sequence of periplasmic 5'-nucleotidase (uridine diphosphate sugar hydrolase, the product of the ushA gene) of E. coli. It also contained regions that showed some homology with the nucleotide binding sites of many nucleotide binding proteins.

5'-Nucleotidase↗