PubMed Health⌕ Search

Biomedical subjects

Y Saka

Publications and source records attributed to Y Saka.

30 records · Page 2Linked to original sources
PubMed1993

Fission yeast cut5+, required for S phase onset and M phase restraint, is identical to the radiation-damage repair gene rad4+.

Fission yeast cut5 mutants cause cytokinesis in the absence of normal nuclear division. We show here that cut5+ is required for both the onset of S phase and the restraint of M phase before the completion of S phase. The primary defects in cut5 mutants occur prior to S phase, but cells suffer lethal damage during M phase. Mitosis and cytokinesis occur in the presence of hydroxyurea or in the double mutant cdc10-cut5 (the cdc10 mutation alone blocks progression from G1 to S). Gene cloning shows that cut5+ is identical to the fission yeast rad4+ gene, which is similar to human XRCC1. The rad4+/cut5+ gene is unique in its positive role for replication/repair and in its negative role for mitosis/cytokinesis. We propose a single/twin chromatid marking model for rad4+/cut5+ function in cell cycle control.

Amino Acid Sequence↗
PubMed1992

Fission yeast pap1-dependent transcription is negatively regulated by an essential nuclear protein, crm1.

The fission yeast pap1+ gene encodes an AP-1-like transcription factor that contains a leucine zipper motif. We identified a target gene of pap1, the p25 gene. The 5' upstream region of the p25 gene contains an AP-1 site, and by DNase I footprint analysis, we showed that the pap1 protein binds to the AP-1 site as well as to a 14-bp palindrome sequence. p25 is overproduced when the pap1+ gene is overexpressed, whereas p25 is not produced at all in the pap1 deletion mutant. p25 was previously found to be overproduced in strains carrying cold-sensitive crm1 mutations whose gene product is essential for viability and is thought to play an important role in maintenance of a proper chromosomal architecture. Deletion and site-directed mutagenesis of sequences upstream of the p25 gene demonstrated that the AP-1 site as well as the palindrome sequence are crucial for transcriptional activation either by pap1 overproduction or by the cold-sensitive crm1 mutation; pap1+ is apparently negatively regulated by crm1+. Moreover, we found that cold-sensitive crm1 mutations are suppressed by the deletion of pap1+, further indicating a close relationship between crm1+ and pap1+. The crm1 protein is highly conserved; the budding yeast homolog, CRM1, which complements the fission yeast cold-sensitive crm1 mutation, was isolated and found to also be essential for viability. These results suggest the functional importance of chromosome structure on the regulation of gene expression through the pap1 transcription factor.

Amino Acid Sequence↗
PubMed1992

[Cold agglutinin hemolytic anemia complicating mycoplasma pneumonia].

A case of Mycoplasma pneumonia complicated with severe hemolytic anemia, which occurred as a result of a high titer of cold agglutinin is presented. A 49 year-old male was admitted because of fever, jaundice and dyspnea. Chest x-ray showed diffuse small nodular infiltrates throughout both lung fields. Laboratory studies disclosed the following values: Hb 4.6 g/dl, Ht 13.9%, reticulocyte 11.5%, direct and indirect Coombs' test positive, haptoglobin 38 mg/dl, ESR 145 mm/hr, cold agglutinin titer 1:2,048 mycoplasma antibody titer 1:640, PPD negative. The diagnosis of autoimmune hemolytic anemia associated with Mycoplasma pneumonia was made, and treatment with minocycline and prednisolone observed striking clinical improvement. It was suggested that the cold exposure was possibly a major factor in the pathogenesis of hemolysis in this patient.

Anemia, Hemolytic, Autoimmune↗
PubMed1989

Correlation between arterial blood pressure and oxygenation in tetralogy of Fallot.

To examine the relationship between arterial blood pressure and oxygenation in patients undergoing complete surgical correction of tetralogy of Fallot, a retrospective study of 16 patients was first performed, looking at the correlation between mean arterial blood pressure (MAP) and arterial oxygen tension (PaO2). The correlation between phenylephrine-induced changes in MAP (delta MAP) and those in PaO2 (delta PaO2) was investigated prospectively in seven patients. In the retrospective study, there was a significant correlation between MAP and PaO2 (n = 66; r = 0.55; P less than 0.01), and most data points with a PaO2 less than 50 mm Hg were associated with a MAP less than 60 mm Hg. In the seven patients who received phenylephrine, 10 micrograms/kg, a significant correlation was found between delta MAP and delta PaO2 (n = 10; r = 0.95; P less than 0.01). These results suggest that in tetralogy of Fallot arterial blood pressure is a determinant of arterial oxygenation, and that the risk of serious hypoxia is significant when MAP is less than 60 mm Hg.

Anesthesia, Inhalation↗
PubMed1988

[Serotype and susceptibilities to eight antibiotics of fifty strains of Pseudomonas aeruginosa isolated from clinical specimens and changes in susceptibilities of Pseudomonas aeruginosa to various antibiotics during a period between 1983 and 1986].

Efficacies of 8 antibiotics against Pseudomonas aeruginosa in the relation to serotypes and clinical sources were investigated on 50 strains isolated from patients at Nagoya Ekisaikai Hospital between August and September, 1986. Disk sensitivity test was carried out simultaneously for 5 antibiotics including piperacillin (PIPC), cefoperazone (CPZ), cefsulodin (CFS), ceftazidime (CAZ) and amikacin (AMK), using the single-disk method. We also examined changes in susceptibilities of P. aeruginosa to 5 antibiotics including PIPC, CFS, fosfomycin, gentamicin (GM) and AMK during last 4 years (1983-1986). The results are summarized as follows. 1. CAZ and AMK proved to have high antibacterial potencies, and their MIC80's (concentrations to inhibit growth of 80% of objective bacteria) were both 6.25 micrograms/ml. Following these two the order of potencies were; CFS, cefpiramide (CPM), PIPC, CPZ, netilmicin (NTL), and cefmenoxime (CMX). Sixty two percent of the strains of P. aeruginosa showed high resistances (MIC greater than 50 micrograms/ml) to CPM, CPZ, NTL and CFS, 58% to PIPC, and 2% to AMK. 2. With regard to serotypes, strains belonging to type E were less susceptible than those belonging to types G and I. Type E strains showed high resistance to all antibiotics except CAZ and AMK. 3. Strains obtained from pura and secreta were relatively susceptible, while those from urines were resistant, to these antibiotics tested, in general. 4. Good correlation between MIC's obtained with the agar dilution method (MIC less than or equal to 12.5 micrograms/ml) and these with the disk sensitivity test (greater than ¿ was observed. chi 2 statistical analysis showed that the results obtained with the 2 methods were closely related (P less than 0.01). 5. P. aeruginosa showed fairly high susceptibility to AMK through the recent 4 years (1983-1986). On the other hand, highly resistant strains against CFS, PIPC, FOM and GM increased rapidly during this period.

Anti-Bacterial Agents↗
PubMed1988

[In vitro combination effects of astromicin and beta-lactam antibiotics against CFS-sensitive and CFS-resistant Pseudomonas aeruginosa. In vitro synergistic activity].

We investigated in vitro synergistic activity of astromicin (ASTM) combined with beta-lactam antibiotics (cefsulodin (CFS), cefoperazone (CPZ), ceftazidime (CAZ), piperacillin (PIPC) and fosfomycin (FOM) against fresh clinical isolated Pseudomonas aeruginosa, which consisted of 13 CFS sensitive (MIC less than or equal to 3.13 micrograms/ml) and 19 CFS resistant (MIC greater than or equal to 400 micrograms/ml) strains according to the FIC index. Against CFS-sensitive P. aeruginosa, ASTM showed good synergistic activities when combined with PIPC (54%), CAZ (38%), CPZ (23%) and CFS (8%). Against CFS-resistant P. aeruginosa, ASTM also showed high synergistic activities when combined with CAZ (63%), CPZ (47%), PIPC (37%) and CFS (11%). Among the CFS-resistant P. aeruginosa, one clinical isolate showed a high sensitivity (MIC0.78 micrograms/ml) against ASTM alone.

Aminoglycosides↗