Search PubMed⌕ Search

Biomedical subjects

S Yoshida

Publications and source records attributed to S Yoshida.

At least 757 records · Page 42Linked to original sources
PubMed1997

A novel protein with DNA binding activity from tobacco chloroplast nucleoids.

A 41-kD DNA binding protein with a basic pl was purified from chloroplast nucleoids in photomixotrophically cultured tobacco cells, and its amino acid sequence was determined. Using this sequence information, its cDNA (CND41) was isolated, and its nucleotide sequence was determined. The predicted amino acid sequence of CND41 has a transit peptide of 120 amino acids and a mature protein of 382 amino acids. A distinctive helix-turn-helix motif in the lysine-rich N-terminal region of the mature protein and an aspartyl protease active site motif were predicted. Expression of a series of truncated CND41 proteins in Escherichia coli indicated that the lysine-rich region is essential for DNA binding and that CND41 nonspecifically binds chloroplast DNA. Protein gel blot analyses showed CND41 mainly in cells and/or tissues containing nonphotosynthesizing, actively growing plastids. In addition, the accumulation of chloroplast transcripts in these cells and/or tissues (e.g., transcripts for QB binding protein of photosystem II [psbA] and large subunit of ribulose bisphosphate carboxylase [rbcL]) was negatively correlated with the accumulation of CND41. Analyses of cultured cells of transgenic tobacco with reduced CND41 levels showed a higher level of expression of chloroplast genes compared with that of the wild type. We discuss the possible function of CND41 as a negative regulator of chloroplast gene expression.

Amino Acid Sequence↗
PubMed1997

Molecular determination of infection source of a sporadic Legionella pneumonia case associated with a hot spring bath.

To determine the infection source of a sporadic Legionella pneumonia case associated with a hot spring bath, we used five molecular methods, including repetitive element polymerase chain reaction (rep-PCR), arbitrarily primed PCR (AP-PCR), ribotyping, restriction endonuclease analysis (REA), and macrorestriction endonuclease analysis (MREA) by pulsed-field gel electrophoresis. L. pneumophila serogroup (SG) 3 strain EY 3702, isolated from an intratracheal specimen of a 71-year-old Japanese female who developed pneumonia after nearly drowning in a hot spring spa bath, produced rep-PCR and AP-PCR fingerprints identical to those of L. pneumophila SG 3 strains EY 3768 and EY 3769 isolated from the bath water. Four epidemiologically unrelated L. pneumophila SG 3 strains showed different rep-PCR or AP-PCR fingerprints from those of the three EY strains (EY 3702, 3768, and 3769). The three EY strains were also genotypically indistinguishable by ribotyping with EcoRI and PstI, by REA with EcoRI or HindIII, and by MREA with NotI. Based on these results, we identified the bath water of the hot spring spa as the source of infection of this patient, even though the viable number of the organisms in the bath water was low (3 CFU/100 ml) when determined 27 days after her nearly drowning.

Aged↗
PubMed1997

Direct detection by PCR of Escherichia coli O157 and enteropathogens in patients with bloody diarrhea.

Direct detection of Escherichia coli O157 and foodborne pathogens associated with bloody diarrhea were achieved using polymerase chain reaction (PCR) after the preparation of DNA from stool specimens using the microspin technique. PCR was compared with cultivation and toxin production tests with respect to the efficiency of detection of each pathogen; E. coli O157, Vibrio parahaemolyticus, Salmonella serovar Enteritidis and Campylobacter jejuni. Detection of some or all of the above pathogens in clinical stool specimens was achieved using PCR. The minimum number of cells required for the detection of the above pathogens by PCR was 10(1) CFUs/0.5 g of stool sample. PCR was completed within 6 hr. The above pathogens were also detected in cultivation and toxin production tests. Partial purification of the template DNA using the microspin technique was essential for the elimination of PCR inhibitors from the DNA samples. This PCR method is an accurate, easy-to-read screening method for the detection of Shiga-like toxin producing E. coli O157 and enteropathogens associated with bloody diarrhea in stool specimens.

Bacteria↗
PubMed1997

N-acetylcysteine attenuates TNF-alpha-dependent reduction of IL-4-induced Fc epsilon RII expression in human monocytes.

We have previously shown that tumor necrosis factor-alpha (TNF-alpha) reduces interleukin-4 (IL-4)-induced Fc epsilon RII expression in human monocytes. It has been shown that TNF-alpha activates nuclear transcriptional factors through the generation of reactive oxygen intermediates (ROIs), and antioxidant N-acetylcysteine (NAC) inhibits TNF-alpha-induced activation of nuclear transcriptional factors. Therefore, we hypothesized that TNF-alpha-dependent reduction of IL-4-induced Fc epsilon RII expression in monocytes might be mediated through the ROIs-activated mechanism. In the present study, to test our hypothesis, we examined the effect of NAC on TNF-alpha-dependent reduction of IL-4-induced Fc epsilon RII expression in human monocytes. NAC attenuated TNF-alpha-dependent reduction of IL-4-induced Fc epsilon RII expression by attenuating TNF-alpha-dependent reduction of Fc epsilon RII mRNA expression. Similarly, the structurally unrelated antioxidant, pyrrolidine dithiocarbamate (PDTC), also effectively attenuated this-reduction. These results indicate that an ROIs-activated and antioxidant-sensitive mechanism might be involved in TNF-alpha-dependent reduction of IL-4-induced Fc epsilon RII expression in monocytes.

Acetylcysteine↗
PubMed1997

Small cell carcinoma of the prostate: a case report.

A case of small cell carcinoma of the prostate without a primary lesion in the lung was reported. The cancer was diagnosed after the patient complained of lumbago caused by bone metastasis. The tumor was 5.9 x 5.0 x 4.6 cm. The patient was treated with 4 courses of chemotherapy using cisplatin and etoposide. The tumor diminished to 4.0 x 4.0 x 3.5 cm after completion of the 4 courses of treatment. Prostatic antigen levels were less than 1.0 ng/mL during the therapy. Neuron-specific enolase levels were 35.9 ng/mL at the beginning of therapy, and decreased to 7.4 ng/mL after completion of 4 courses of treatment. The patient died 3 months after the completion of treatment. This regimen had some value for inhibiting the growth of small cell carcinoma.

Biopsy, Needle↗
PubMed1997

Contribution of neutrophils to lipopolysaccharide-induced tumor necrosis factor production and mortality in a carrageenan-pretreated mouse model.

Carrageenan (CAR) pretreatment primes mice for lipopolysaccharide (LPS)-induced tumor necrosis factor (TNF)-alpha production in sera and increases their mortality rate. To study the contribution of neutrophils in this model, blood neutrophil count was regulated with cyclophosphamide. After LPS challenge, both serum TNF-alpha activity and mortality risk ratio were significantly higher in neutrophilic mice, but significantly lower in neutropenic mice. In vitro, CAR treatment primed for TNF-alpha production of blood neutrophils, but conversely, that of monocytes was suppressed. We suggest that neutrophils are the major cells to produce TNF-alpha and to determine mouse mortality after LPS challenge in the mouse CAR model.

Animals↗
PubMed1997

Development of a new seminested PCR method for detection of Legionella species and its application to surveillance of legionellae in hospital cooling tower water.

The presence of PCR inhibitors in water samples is well known and contributes to the fact that a practical PCR assay has not been developed for legionella surveillance. In this study, we devised a new seminested PCR assay for detection of Legionella spp. in water samples as a means of overriding the PCR inhibitors without loss of sensitivity. The seminested PCR assay utilized primers to amplify the 16S rRNA gene (LEG primers) of 39 Legionella spp. The assay was specific to legionellae, and the sensitivity was 1 fg of extracted Legionella DNA in laboratory examination. To evaluate the feasibility and sensitivity of the PCR assay in identifying the presence of legionellae, it was used to survey Legionella contamination in the water of 49 cooling towers of 32 hospitals. A commercially available EnviroAmp Legionella kit and a culture method were also used in the survey for comparison with the seminested PCR assay. The detection rates of legionellae in the samples were 91.8% (45 of 49) by the PCR assay and 79.5% (39 of 49) by the culture method. The EnviroAmp kit revealed that 30.6% of the water samples (15 of 49) contained inhibitors of the PCR amplification. However, the seminested PCR assay could produce the Legionella-specific DNA bands in 14 of the 15 samples. Although 8 of the 14 samples were positive in the first-step PCR, 6 of the 14 samples became positive in the second-step PCR. These results suggest that the effect of PCR inhibitors in samples, if any, can be reduced because of the dilution of the sample in the second-step PCR and that sensitivity of detection can be increased by the second-step PCR. Thus, the seminested PCR assay with LEG primers to amplify the 16S rRNA gene of 39 Legionella spp. was a practical and sensitive method to detect Legionella spp. in water samples.

Air Conditioning↗
PubMed1997

Involvement of interleukin-8, vascular endothelial growth factor, and basic fibroblast growth factor in tumor necrosis factor alpha-dependent angiogenesis.

Tumor necrosis factor alpha (TNF-alpha) is a macrophage/monocyte-derived polypeptide which modulates the expression of various genes in vascular endothelial cells and induces angiogenesis. However, the underlying mechanism by which TNF-alpha mediates angiogenesis is not completely understood. In this study, we assessed whether TNF-alpha-induced angiogenesis is mediated through TNF-alpha itself or indirectly through other TNF-alpha-induced angiogenesis-promoting factors. Cellular mRNA levels of interleukin-8 (IL-8), vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and their receptors were increased after the treatment of human microvascular endothelial cells with TNF-alpha (100 U/ml). TNF-alpha-dependent tubular morphogenesis in vascular endothelial cells was inhibited by the administration of anti-IL-8, anti-VEGF, and anti-bFGF antibodies, and coadministration of all three antibodies almost completely abrogated tubular formation. Moreover, treatment with Sp1, NF-kappaB, and c-Jun antisense oligonucleotides inhibited TNF-alpha-dependent tubular morphogenesis by microvascular endothelial cells. Administration of a NF-kappaB antisense oligonucleotide almost completely inhibited TNF-alpha-dependent IL-8 production and partially abrogated TNF-alpha-dependent VEGF production, and an Sp1 antisense sequence partially inhibited TNF-alpha-dependent production of VEGF. A c-Jun antisense oligonucleotide significantly inhibited TNF-alpha-dependent bFGF production but did not affect the production of IL-8 and VEGF. Administration of an anti-IL-8 or anti-VEGF antibody also blocked TNF-alpha-induced neovascularization in the rabbit cornea in vivo. Thus, angiogenesis by TNF-alpha appears to be modulated through various angiogenic factors, both in vitro and in vivo, and this pathway is controlled through paracrine and/or autocrine mechanisms.

Animals↗
PubMed1997

High frequency of K-ras mutations in human colorectal hyperplastic polyps.

BACKGROUND: Hyperplastic polyps are common benign colorectal polyps, and are thought to have little association with malignant tumours in the colorectum. However, several reports suggest that some hyperplastic polyps may develop into colorectal neoplasms. AIM: To clarify genetic alterations in colorectal hyperplastic polyps. METHODS: Twenty eight colorectal polyps having serrated components were resected from patients endoscopically. The K-ras gene mutations in codons 12 and 13 were analysed by PCR-RFLP. Intranuclear p53 protein was immunostained by the avidin-biotin complex method. RESULTS: A mutation of the K-ras gene was detected in nine (47%) of 19 hyperplastic polyps, and five (56%) of nine adenomas. p53 protein nuclear accumulation was detected immunohistochemically in two (22%) of nine adenomas, but not in any of the hyperplastic polyps. CONCLUSION: Some hyperplastic polyps may be true neoplastic lesions, and could be precursors of malignant neoplasia.

Adenoma↗
PubMed1997

Effect of methionine-free total parenteral nutrition and insulin-like growth factor I on tumor growth in rats.

The objectives of this study were to evaluate the effect of insulin-like growth factor I (IGF-I) on the fractional synthesis rate (FSR) of muscle and whole body protein breakdown rate (WPBR) during methionine-free total parenteral nutrition (MTPN). We also determined whether the inhibition of endogenous methionine availability reduced tumor protein synthesis. AH109A hepatoma cells were inoculated onto the backs of Donryu rats on day 0. On day 10, the rats were catheterized for TPN and assigned to one of four groups: 1) standard TPN (STPN), 2) STPN + IGF-I, 3) MTPN, or 4) MTPN + IGF-I. The addition of IGF-I to MTPN reduced the loss of body weight by both increasing muscle FSR and reducing WPBR. The tumor FSR did not differ between MTPN + IGF-I and MTPN. The methionine extraction ratio from the liver was negative with MTPN + IGF-I but positive in the other groups. We concluded that IGF-I blockage of endogenous methionine release from peripheral protein sites was associated with a shift to liver-derived methionine, with no change in tumor growth in MTPN-treated rats.

Animals↗
PubMed1997

Phase I-II study of irinotecan hydrochloride combined with cisplatin in patients with advanced gastric cancer.

PURPOSE: A dose-escalation study of irinotecan hydrochloride (CPT-11) combined with fixed-dose cisplatin was conducted to determine the maximum-tolerated dose (MTD), dose-limiting toxicities, and objective response rate in patients with advanced gastric cancer. PATIENTS AND METHODS: Twenty-four patients with or without prior chemotherapy were enrolled. All patients were assessable for toxicities and response. On day 1, CPT-11 was administered as a 90-minute intravenous (I.V.) infusion, which was followed 2 hours later by a 120-minute I.V. infusion of cisplatin 80 mg/m2. CPT-11 alone at the same dose was administered again on day 15. The treatment was repeated every 4 weeks until disease progression was observed. The initial dose of CPT-11 was 60 mg/m2, and was escalated in increments of 10 mg/m2 until severe or life-threatening toxicity was observed. RESULTS: The MTD of this combination was CPT-11 80 mg/m2. At this dose level, 16.7% of patients (two of 12) had leukopenia of less than 1,000/microL, 66.7% (eight of 12) had neutropenia of less than 500/microL, and 16.7% (two of 12) had severe diarrhea of grade 4 during the first course. The dose-limiting toxicity was neutropenia. Ten patients achieved a partial response (PR), and the overall response rate was 41.7% among 24 patients (95% confidence interval, 21.9% to 61.4%). CONCLUSION: The recommended dose and schedule is CPT-11 70 mg/m2 on days 1 and 15 and cisplatin 80 mg/m2 on day 1 every 4 weeks. This combination of CPT-11 and cisplatin, considered to be active against advanced gastric cancer with acceptable toxicity, should be further assessed in a phase II study.

Adult↗
PubMed1997

Treatment of advanced Hodgkin's disease with chemotherapy--comparison of MOPP/ABV hybrid regimen with alternating courses of MOPP and ABVD: a report from the National Cancer Institute of Canada clinical trials group.

PURPOSE: This randomized, prospective trial compares outcomes for patients with advanced Hodgkin's disease treated with mechlorethamine, vincristine, procarbazine, and prednisone (MOPP)/doxorubicin, bleomycin, and vinblastine (ABV) hybrid regimen or alternating MOPP/doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD). METHODS: Three hundred one patients with advanced Hodgkin's disease were randomized to receive MOPP/ ABV hybrid regimen or alternating MOPP/ABVD after stratification for prior treatment, B symptoms, and treatment center. Eligible patients were either previously untreated and found to have stage IIIB, IVA, or IVB disease or previously treated with wide-field irradiation. Responding patients received a minimum of eight cycles of chemotherapy. Those with residual disease in a localized region received irradiation between the sixth and seventh cycle of treatment. RESULTS: Response rates to the two regimens were similar. Five-year overall survival rates were 81% and 83% for MOPP/ABV hybrid and alternating MOPP/ ABVD, respectively (P = .74; 95% confidence interval [CI] for the difference, -11% to 7%). Five-year failure-free survivals were 71% and 67% for MOPP/ABV hybrid and alternating MOPP/ABVD, respectively (P = .87; 95% CI for the difference, -9% to 17%). Significantly more episodes of febrile neutropenia and stomatitis were observed with the MOPP/ABV hybrid regimen; there was no significant difference in fatal toxicity. Patients with predefined, high-quality partial responses (PR-1s) had results similar to those with complete responses (CRs). Planned subset analysis showed no significant difference in outcome between the two arms of the trial for patients with newly diagnosed disease (5-year failure-free survival rates were 70% for MOPP/ABV hybrid and 59% for alternating MOPP/ABVD; P = .180), but superiority of alternating MOPP/ABVD for patients with prior irradiation (5-year failure-free survival 94% v 73%; P = .017). CONCLUSION: MOPP/ABV hybrid and alternating MOPP/ABVD regimens are equally effective for patients with advanced Hodgkin's disease.

Actuarial Analysis↗
PubMed1997

Incomplete thyrotroph suppression determined by third generation thyrotropin assay in subacute thyroiditis compared to silent thyroiditis or hyperthyroid Graves' disease.

Serum TSH concentrations were determined by both second and third generation assays in three types of thyrotoxicosis associated with subacute thyroiditis, silent thyroiditis, and hyperthyroid Graves' disease at the time of each patient's initial visit to the clinic. Serum TSH concentrations as measured by the second generation assay with an analytical sensitivity of 0.04 mU/L were below the detection limit in every patient. In contrast, serum TSH concentrations as measured by the third generation assay with an analytical sensitivity of 0.009 mU/L were below the detection limit in 18 of 21 (86%) patients with Graves' disease, 18 of 20 (90%) with silent thyroiditis, but only 4 of 18 (22%) with subacute thyroiditis. Changes in serum TSH concentrations were studied in healthy volunteers given daily 75 micrograms of T3; their serum TSH concentrations on the second generation assay fell below the detection limit within 3 days in every subject. However, the TSH concentration measured by the third generation assay remained above the detection limit in 6 of 8 normal subjects even on the 14th day of therapy. The reason for incomplete TSH suppression in most subacute thyroiditis patients may be that these patients had notable neck pain, and their initial visit to the clinic may have occurred earlier after the onset of disease than with patients who have had silent thyroiditis or Graves' disease. Thus, the serum TSH concentration had not decreased sufficiently below the detection limit at the time blood was drawn. The data suggest also that the highly sensitive TSH assay, if the level is above the detection limit, can be used to suppose that the short duration of the initiation of thyrotoxicosis indicates a case of subacute thyroiditis.

Acute Disease↗
PubMed1997

Acute aquaresis by the nonpeptide arginine vasopressin (AVP) antagonist OPC-31260 improves hyponatremia in patients with syndrome of inappropriate secretion of antidiuretic hormone (SIADH).

The present study was undertaken to determine whether the non-peptide V2 arginine vasopressin (AVP) antagonist 5-dimethylamino- 1[4-(2-methylbenzoylamino)benzoyl]-2,3,4,5-tetrahydro-1H-benzazepi ne hydrochloride (OPC-31260) produces water diuresis and improves hyponatremia in patients with the syndrome of inappropriate secretion of antidiuretic hormone (SIADH). Eleven patients (9 males and 2 females, 64 +/- 3.5 yr) with SIADH were included in the present protocol, which was comprised of 3 successive days. Day 1 was a control day, and on days 2 and 3 OPC-31260 was administered intravenously. Five blood and urine collections were made at 1-2 h intervals during the 6 h observation period each day. A single administration of 0.25 and 0.5 mg/kg OPC-31260 increased the 4 h cumulative urine volume and decreased urinary osmolality to below 225 mOsm/kg H2O. Such a diuretic effect was independent of an increase in urinary solute excretions. This aquaresis by 0.5 mg/kg OPC-31260 caused a significant increase in serum sodium level by approximately 3 mEq/L. The antagonistic effect of OPC-31260 lasted for 4 h when it was given intravenously. These results indicate that OPC-31260 is an effective therapeutic agent for hyponatremia in patients with SIADH.

Aged↗
PubMed1997

[Bone mineral density by ultrasonic measurement in pre- and postmenopausal women--relationship with sex hormones and nutritional states].

In this cross-sectional study we evaluated the relationships of the sex hormones, estradiol (E2), free testosterone (free T), dehydroepiandrosterone-sulfate (DHEA-S), sex hormone-binding globulin (SHBG) and nutritional status to bone density assessed by ultrasonic measurements. The subjects were 16 premenopausal (38-50 years) and 28 postmenopausal (47-86 years) women living in a rural area in Yamaguchi Prefecture in Japan. They were healthy and did not smoke or drink. Speed of sound (SOS), broadband ultrasound attenuation (BUA) and the stiffness index (SI) were used as the indices to evaluate ultrasonic bone density (UBD) for the calcaneus. In premenopausal women, the concentration of free T was negatively associated with BUA. The DHEA-S concentration had a significant negative correlation with BUA after adjustments for age and body mass index (BMI). Daily intakes of fat, animal fat, animal protein, calcium (Ca) and vitamin B2 (Vit B2) were positively associated with UBD. In postmenopausal women, although DHEA-S positively correlated with SOS, BUA and SI, the significance disappeared after adjustments for age and BMI. The protein intake was positively associated with BUA. Multiple regression analysis for SOS, BUA and SI as dependent variables was performed. Independent variables were age, BMI, E2, free T, DHEA-S, SHBG and daily intakes of animal fat, animal protein, Vit B2 and Ca. In premenopausal women, the animal fat intake contributed significantly and positively to the variations of SOS and SI. The intake of Vit B2 had a significant positive correlation, and the level of DHEA-S had a significant negative correlation with BUA. In postmenopausal women, age and BMI contributed significantly to the variations of SOS, BUA and SI, while the nutritional variables and the sex hormones were not found to be significant. In conclusion, different factors predicting UBD were suggested for pre- and postmenopausal women. In premenopausal women, daily intakes of animal fat and Vit B2 might be effective to maintain higher bone density. Further investigations are still needed to clarify the relationship between DHEA-S and UBD.

Adult↗
PubMed1997

Multitracer studies on the accumulation of radionuclides in mushrooms.

We used the multitracer technique to study the transfer of several radionuclides to two mushroom species. Radionuclides accumulated in the fruiting bodies of the mushrooms in the order of 83Rb > 65Zn > 54Mn > 22Na > 75Se and 85Sr > 60Co > 88Y, 102Rh, 139Ce, 143.144Pm, 146.153Gd and 173Lu > 175Hf. The concentration ratio values for 83Rb, 65Zn and 54Mn in the fruiting bodies were more than 10, whereas those for 60Co, 88Y, 102Rh, 121mTe, 175Hf and the rare earth elements were less than 1. There were major differences in the accumulations of the alkali elements.

Basidiomycota↗
PubMed1997

Substrate specificities of alpha-galactosidases from yeasts.

Twenty-nine strains of yeasts, which are capable of using galactose, melibiose, or raffinose, were screened for alpha-galactosidase production. Among the strains, 5 produced intracellular and extracellular alpha-galactosidases, and 2 produced only intracellular enzyme. Substrate specificities of these enzymes were explored using 6(3)-alpha-D-galactosyl-1,4-beta-D-mannotriose and 6(3)-alpha-D-galactosyl-1,4-beta-D-mannotetraose. All enzymes liberated the terminal galactose from 6(3)-alpha-D-galactosyl-1,4-beta-D-mannotriose, but did not the stub galactose from 6(3)-alpha-D-galactosyl-1,4-beta-D-mannotetraose.

Fungal Proteins↗