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Biomedical subjects

S Yoshida

Publications and source records attributed to S Yoshida.

At least 397 records · Page 22Linked to original sources
PubMed2000

Separation of lactoferrin-a and -b from bovine colostrum.

Bovine lactoferrin was separated into lactoferrin-a and lactoferrin-b from bovine colostrum. Lactoferrin-a was eluted at 0.38 M NaCl and lactoferrin-b was eluted at 0.43 M NaCl by carboxymethyl cation-exchange chromatography at pH 7.7, 0.05 M phosphate buffer. The molecular weights were estimated at 84,000 for lactoferrin-a and 80,000 for lactoferrin-b. Lactoferrin-a contents were 258.0 mg/L and lactoferrin-b contents were 524.3 mg/L of colostrum for cow 19. From colostrum to normal milk, total lactoferrin was from 17.1 to 129.4 mg/L during the normal lactational period; however, lactoferrin did not separate clearly into lactoferrin-a and lactoferrin-b. The lactoferrin-a measured from six cows was 258.0, 114.0, 112.8, 64.0, 59.7, and 22.4 mg/ L and the lactoferrin-b 524.3, 331.8, 184.7, 170.7, 129.3, and 44.0 mg/L, respectively. The average was 105.2 mg (31.3%) for lactoferrin-a and 230.8 mg (68.7%) for lactoferrin-b.

Animals↗
PubMed2000

Cyclooxygenase expression in the gallbladder.

The COX expressions were evaluated separately in the epithelium and in the stroma of gallbladder cancer, chronic cholecystitis, xanthogranulomatous cholecystitis (XGC) and the normal gallbladder. In normal gallbladder COX-2 expression rate was significantly higher in the epithelium than in the stroma. The COX-2 expression rate in the epithelium of non-cancerous adjacent epithelium to cancerous lesion was significantly lower than those not only of cancer, but also chronic cholecystitis, XGC and normal gallbladder. In stroma, the COX-2 expression rate in cancer, chronic cholecystitis and XGC were significantly higher than that of the normal gallbladder. The rate in non-cancerous adjacent stroma to cancer is significantly lower than that of cancer and XGC. However, the difference of rate between of normal and of chronic cholecystitis was not significant. The COX-2 expression rates were significantly higher in both the epithelium and the stroma in the well and moderately differentiated cancer group than in the poorly and undifferentiated cancer group. Our results suggest that COX-2 expression in the gallbladder may be regulated by various factors and not directly related to carcinogenesis. The significance of its repression in the non-cancerous adjacent tissue to cancer lesion should be re-evaluated.

Cholecystitis↗
PubMed2000

Clinical implications of immunoreactivity of thymidylate synthase and dihydropyrimidine dehydrogenase in gastric cancer treated with oral fluoropyrimidine (S-1). Study Group of S-1 for Gastric Cancer.

Many reports have demonstrated that thymidylate synthase (TS) and dihydropyrimidine dehydrogenase (DPD) are biomarkers for the response and prognosis of patients treated with 5-fluorouracil (5-FU)-based chemotherapy. A newly developed orally administered drug, fluoropyrimidine (S-1), has been developed with clinical efficacy when combined with an inhibitor of DPD. In this study, the relationship between immunoreactivity to TS and DPD in biopsy specimens and the effects of chemotherapy was investigated in 41 patients treated with S-1 therapy for advanced gastric cancer. Response rates were 54% (13/24) in TS(+) and 53% (9/17) in TS(-) patients (p=0.938), and those of DPD(+) and (-) patients were 61% (11/18) and 48% (11/23) (p=0.397), respectively. The median survival time of all the subjects was 253 days. There was no significant difference in median survival time between TS(+) patients (284 days) and (-) patients (189 days: p=0.670). The 18 DPD(+) patients had median survival times slightly longer (338 days) than the 23 patients with DPD(-) (207 days: p=0.206). This study indicates that S-1 may be effective in the treatment of gastric cancer patients, regardless of intratumoral TS and DPD immunoreactivity status. Further studies are needed to confirm these results with larger numbers of patients.

Adult↗
PubMed2000

Toremifene-induced fatty liver and NASH in breast cancer patients with breast-conservation treatment.

We have described fatty liver, diagnosed by computed tomography scanning (CT) in more than 30% of patients with breast cancer who received tamoxifen. Therefore, it is urgent to elucidate the frequency and the degree of fatty liver induced by toremifene, an analogue of tamoxifen, which is also used in breast cancer. We enrolled 52 breast cancer patients who were treated with breast-conservation treatment and administered oral toremifene for 3-5 years as adjuvant endocrine therapy. We evaluated the degree of fatty liver by abdominal CT performed annually. CT demonstrated toremifene-induced fatty liver in four (7.7%) of 52 breast cancer patients. Toremifene-induced fatty liver did not correlate with abnormal levels of AST, ALT, GGT or total cholesterol. One patient who demonstrated moderate fatty liver by CT was histologically diagnosed as non-alcoholic steatohepatitis (NASH) by liver biopsy. The incidence of toremifene-induced fatty liver was significantly lower than that induced by tamoxifen. Accordingly, in terms of fatty liver and NASH, toremifene is considered to be more appropriate agent than tamoxifen. Though toremifene is less likely to induce fatty liver, the possibility remains that toremifene-induced steatohepatitis occurs. Because the diagnosis of fatty liver or NASH can be easily missed if only a blood test is performed, it is necessary to screen fatty liver by annual CT examination for patients who receive an antiestrogen agent.

Alanine Transaminase↗
PubMed2000

New cytotoxic agents, BE-54238A and B, produced by a streptomycete.

New cytotoxic substances, designated BE-54238A and B, were isolated from the culture broth of Streptomyces sp. A54238. The active principles were extracted from the mycelium by methanol and purified by Diaion HP-20 and Sephadex LH-20 column chromatographies. BE-54238A and B exhibited cytotoxic activity against murine and human tumor cell lines.

Animals↗
PubMed2000

PF1163A and B, new antifungal antibiotics produced by Penicillium sp. II. Physico-chemical properties and structure elucidation.

The structures of new antifungal antibiotics, PF1163A and B, were elucidated by spectroscopic analyses of the degradation products and by X-ray crystallography of the de-2-hydroxyethyl derivative of PF1163B. Both antibiotics consist of a 13-membered macrocyclic structure containing a derivative of N-methyl tyrosine and a hydroxy fatty acid. PF1163A differs from PF 1163B by having an additional hydroxyl group on the side chain.

Antifungal Agents↗
PubMed2000

Evaluation of flash echo imaging of the canine gastrointestinal tract.

Although it is important to assess gastrointestinal blood flow, no generally useful, noninvasive assessment method has been established. Harmonic flash echo imaging, which is an intermittent second harmonic imaging technique, has recently become available to evaluate blood flow. We investigated the usefulness of harmonic flash echo imaging in the assessment of the gastrointestinal tract, and we used this technique to study the effect of nicotine on small bowel blood flow. Harmonic flash echo imaging was performed at the beginning of intravenous injection of a contrast agent. It was also performed on the small bowel immediately before and 10 min after nicotine administration to evaluate blood flow. Gastric and small bowel walls were clearly enhanced on the primary images. Small bowel enhancement, which is regarded as transmural blood flow, significantly decreased after nicotine administration. Harmonic flash echo imaging appears to be useful in the assessment of the transmural blood flow in the gastrointestinal wall.

Animals↗
PubMed2000

Ionizing radiation-induced apoptosis in human lymphoma cell lines differing in p53 status.

Most of malignant lymphomas have been shown to be relatively radiosensitive clinically, but some, especially recurrent ones, are frequently highly radioresistant. To clarify the origin of the difference, we examined ionizing radiation (IR)-induced apoptosis in three closely related human lymphoma cell lines (DL-40, DL-95, and DL-110) that differ in p53 status. DL-95 and DL-110 cells have a wild-type p53, whereas DL-40 cells carry a T to G transition in exon 5 of the p53 gene, resulting in a change of Cys to Phe at codon 176. Irradiation of DL-40 cells (mutant-type p53) with 5 Gy gamma-rays resulted in delayed apoptosis with membrane changes (annexin-V expression) 13 h after IR, and caspase-3 activation 23 h after IR, whereas apoptotic response was not identified in DL-95 cells until 48 h after IR in spite of their normal p53 status. Concerning DL-110 cells, delayed and reduced apoptotic response was revealed both microscopically and by DNA fragmentation assay. These results suggested that IR-induced apoptosis in DL-40 cells is mediated by a mechanism involving the caspase-3 cascade of the p53-independent pathway, and that some unknown mechanism inhibited IR-induced apoptosis in existence of wild-type p53, especially for DL-95 cells.

Annexin A5↗
PubMed2000

MR appearance of paraganglioma of the cauda equina. Case reports.

PURPOSE: To investigate the value of MR imaging for preoperative diagnosis of paraganglioma of the cauda equina. MATERIAL AND METHODS: A retrospective review of 2 cases of paraganglioma of the cauda equina examined with MR imaging was undertaken. Features assessed included the homogeneity of the lesions, presence or absence of serpiginous flow void and thin hypointense margins. RESULTS: In case 1, the tumor was hyperintense on the postcontrast examination and serpiginous flow void suggested vessels in the upper pole of the tumor. In case 2, the tumor was encapsulated by a thin hypointense margin on both T1- and T2-weighted images, which suggested hemosiderin. CONCLUSION: The MR appearance may be of great value in the preoperative diagnosis of paraganglioma of the cauda equina.

Cauda Equina↗
PubMed2000

[Preliminary study of calculating cerebral arterial blood oxygen saturation using MRI].

To assess whether cerebral arterial blood oxygen saturation (SaO2) can be calculated by EPI, we examined the relationship between peripheral SaO2 and T2+ signal intensity (SI) changes in the brain in three normal subjects, using 1.5 Tesla MRI. To decrease SaO2, hypoxia was induced by 100% helium-gas inhalation (60 sec). SI declined as SaO2 decreased during helium inhalation, while rapid recovery of SI to the baseline was noted with recovery from hypoxia. The differential effective transverse relaxation rate was closely correlated with SaO2 (r > 0.94). Consequently, using MRI, we were able to calculate arterial SaO2.

Cerebral Arteries↗
PubMed2000

Off-pump coronary artery bypass: early results.

BACKGROUND: Coronary artery bypass grafting (CABG) on a beating-heart has gained the attention of cardiac surgeons and shown favorable initial results. However, only a few follow-up results have been reported. We report herein our one-year experiences of off-pump CABG performed at Shin-Tokyo Hospital. METHODS: Retrospective chart review was performed for patients who underwent off-pump CABG and conventional isolated CABG between 01/01/98 and 12/31/98. Preoperative, perioperative, and follow-up data were collected. RESULTS: Among 315 cases of isolated CABG, 94 cases were off-pump CABG (male/female 69/25, mean age 67.7). Mean number of distal anastomoses performed by off-pump CABG was 1.7 +/- 0.7 (42 cases of single-vessel revascularization and 52 cases of more than double- vessel revascularization). In off-pump CABG, there were no hospital deaths and 6 major complications including 2 incidences of perioperative myocardial infarction. Postoperative angiography before hospital discharge was performed in 56 patients (59.6%, 98 anastomosis) and revealed 5 occlusions, giving a graft patency rate of 94.9%. During the follow-up (11.4 +/- 4.1 months), there was 1 late non-cardiac death and 11 cardiac events. The event-free rate at 18 months was 94.0% in off-pump CABG, showing no significant difference from the event-free rate after conventional CABG (94.0% at 18 months, p = 0.135). Follow-up angiography was performed in 21 patients (33 anastomoses) at a mean interval of 3.6 months and showed 4 graft occlusions, giving a patency rate of 92.7%. CONCLUSION: Both hospital and early results of off-pump CABG were acceptable. Off-pump CABG can be safely performed in selected patients.

Adult↗
PubMed2000

Effects of N(G)-monomethyl-L-arginine on Ca(2+) current and nitric-oxide synthase in rat ventricular myocytes.

The effects of N(G)-monomethyl-L-arginine (L-NMMA), a nitric-oxide synthase (NOS) inhibitor, on the L-type Ca(2+) current (ICa) and NO effects on NOS were determined in rat ventricular myocytes. L-NMMA (10 and 100 microM) had no significant effect on basal ICa, but in a cAMP-stimulated condition due to forskolin (1 microM) or milrinone (10 microM), a cGMP-inhibited cAMP-phosphodiesterase (PDE), L-NMMA (10 and 100 microM) concentration dependently augmented ICa. The enhancing effects of L-NMMA (10 and 100 microM) on ICa were not seen in the presence of either a nonselective inhibitor of PDE, 3-isobutyl-1-methylxanthine (20 microM), resulting in a stimulated ICa condition or a cGMP-dependent protein kinase activator, 8-bromo-cGMP (200 microM). 8-Bromo-cGMP (200 microM) inhibited 100 microM L-NMMA-induced ICa increase in the simultaneous application of forskolin (1 microM). Acetylcholine (ACh; 1 and 3 microM) inhibited 1 microM forskolin-stimulated ICa in a concentration-dependent manner, but this inhibitory action of ACh was significantly attenuated by the additional application of L-NMMA (100 microM). In the continuing presence of both L-NMMA (100 microM) and forskolin (1 microM), ACh (6 microM) had no inhibitory effect on ICa. In another series of experiments with isolated ventricular myocytes, we obtained both the positive staining of NADPH-diaphorase activity and the expression of the endothelial isoform of NOS. These data suggest that the effect of L-NMMA on ICa in a cAMP-stimulated condition with or without cholinergic inhibition is due to inhibition (acute effects) of a cGMP-stimulated cAMP-PDE via inhibition of the endothelial isoform of NOS.

1-Methyl-3-isobutylxanthine↗
PubMed2000

Recovery of hematopoietic progenitor cells in patients with severe aplastic anemia who obtained good clinical response with a combination therapy of immunosuppressive agents and recombinant human granulocyte colony-stimulating factor.

Seventeen patients with newly diagnosed acquired severe aplastic anemia were treated with a combination of immunosuppressive drugs consisting of anti-lymphocyte or anti-thymocyte globulin, cyclosporin A (CyA), methylprednisolone, and recombinant human granulocyte colony-stimulating factor (G-CSF). Fourteen (82%) of the 17 patients achieved good response (GR), and 3 (18%) had no response. Among the 14 GR patients, 5 (36%) later evolved clonal diseases, 1 developed myelodysplastic syndrome, and 4 developed paroxysmal nocturnal hemoglobinuria. The numbers of granulocyte-macrophage colony-forming units (CFU-GM) and erythrocyte burst-forming units were markedly low or absent in all cases before therapy. After therapy, those numbers in 13 patients among 14 responders recovered to the level of the normal control at the time of GR. However, the CFU-GM number substantially declined after that but gradually recovered again to reach a normal level over longer clinical courses. The positive rate for HLA-DRB1*1501 was 60% (3/5) among 5 CyA-dependent patients, which tended to be higher than the 20% (1/5) among 5 CyA-independent patients. Thus, immunosuppressive therapy combined with G-CSF provides a high rate of good hematological response accompanied by the apparent recovery of the hematopoietic progenitor compartments.

Adolescent↗
PubMed2000

Phenotype-genotype correlation in CD36 deficiency types I and II.

CD36 deficiency was studied with attention to the phenotype-genotype relationship. The diagnosis of CD36 deficiency was made when CD36 was negative on platelets (type II) or on both platelets and monocytes (type I). Among 827 apparently healthy Japanese volunteers, the type I and II deficiencies were found in 8 (1.0%) and 48 (5.8%), respectively. The T for C substitution at nt478 for Pro90Ser and the insertion of A at nt 1159 constituted the major causes of type I and II deficiencies. The dinucleotide deletion at nt539 had a minor role. In two family studies, we found a previously unreported polymorphic site in the 5'-proximal flanking region and the 3'-untranslated region. Including these new polymorphisms, DNA sequence other than the three known mutations affecting CD36 expression was not observed in the CD36 gene, calling into question the previous hypothesis that a platelet-specific silent allele exists near or at the CD36 gene.

Alleles↗
PubMed2000

Transcription factor Sp3 activates the liver/bone/kidney-type alkaline phosphatase promoter in hematopoietic cells.

The promoter region of the liver/bone/ kidney-type alkaline phosphatase gene was examined to define the cis-acting regulatory sequences and transcription factors responsible for its expression in hematopoietic cells. Transient transfection experiments revealed that regions deleted up to -154 base pairs upstream from the transcription initiation site had significant activities to induce bacterial chloramphenicol acetyltransferase gene. The shortest DNA fragment was found to contain three GC boxes in addition to a TATA box. Electrophoretic mobility shift assay and Southwestern analysis showed that Sp3 could bind to the fragment. Western blot analysis also detected Sp3 protein in eluate from the DNA probe mixed with the nuclear extracts. Through the use of Drosophila Schneider cells that lack the Sp1 family of transcription factors, Sp3 was shown to activate the basal promoter in a dose-dependent manner. When the amount of Sp3 was limited, the most proximal GC box was found to be critical for the basal promoter activity.

Alkaline Phosphatase↗