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Biomedical subjects

Y Yoshida

Publications and source records attributed to Y Yoshida.

At least 757 records · Page 42Linked to original sources
PubMed1994

Predictors of postoperative distant recurrences in esophageal carcinoma.

Pathologic factors and the number of nucleolar organizer region proteins (AgNORs) were evaluated as predictors of postoperative recurrence in distant organs in 92 patients with curatively resected esophageal carcinoma. The rate of distant recurrence was significantly higher in patients with venous invasion (53%; 19 of 36) than in those without invasion (21%; 12 of 56) (p < 0.01) and was also higher in patients with an AgNOR score greater than or equal to 4 (49%; 19 of 39) than in those with an AgNOR score less than 4 (23%; 12 of 53) (p < 0.02). The rate of recurrence was significantly higher in patients with both venous invasion and AgNOR score greater than or equal to 4 (67%; 16 of 24) than in the other patients. These findings indicate that the combination of venous invasion and a high AgNOR score predicts distant postoperative recurrences in patients with curatively resected esophageal carcinoma.

Adult↗
PubMed1994

Pineal yolk sac tumor in a 65-year-old man.

A 65-year-old man presented with a case of pure yolk sac tumor in the pineal region. The patient was admitted with a gait disturbance and elevated alpha-fetoprotein levels in serum and cerebrospinal fluid. He underwent total resection of the tumor. Cisplatin-vinblastine-bleomycin therapy was interrupted because of severe syndrome of inappropriate secretion of antidiuretic hormone, and there was recurrence of the tumor. Five months after the operation, he died in spite of carboplatin-etoposide therapy. A review of the literature revealed no previous report of pineal yolk sac tumor in an elderly patient. Problems in the diagnosis and treatment of such cases are discussed.

Aged↗
PubMed1994

Alteration in length of telomeric repeats in lung cancer.

We investigated the relationship between telomere length and various characteristics of tumor cells in 46 lung cancer specimens (40 primary lesions and six metastatic lesions). Three variant patterns of telomere length were observed in 16 cases (34.8%): reduction in 13 cases, elongation in two cases, and convergence in one case. These variant patterns were frequently observed in small cell carcinomas, in metastatic lesions, and in cases which possessed the S-type allele of the L-myc gene. All three cases with telomere elongation or convergence were associated with a poor prognosis. This is compatible with the previous report suggesting that telomerase activity may be an indicator of immortality in vitro. In adenocarcinoma, telomere reduction or elongation was also observed in the early stages with a low percentage of cells in the S-phase, while in cases with other histologic types, these changes were observed only in late stage, in metastatic lesions, or in cancerous tissues with a high percentage of cells in the S-phase. Although the reduction of telomere length in these tissues may be a result of many cell divisions, it may represent another stage of carcinogenesis in early-stage adenocarcinoma.

Aged↗
PubMed1994

Resolution of 4-(4-chlorobenzyl)-2-(hexahydro-1-methyl-1H-azepin-4yl)-1(2H)-phthalazi none enantiomers in plasma with frit-FAB LC-MS using a conalbumin column.

A new column-switching method for analysis of drug enantiomers in plasma has been developed with liquid chromatography-frit fast atom bombardment mass spectrometry in combination with a chiral resolution column, which consists of conalbumin (egg-white glycoprotein) immobilized on silica gel and can be used in the reversed-phase separation mode. This method makes it possible to inject a large volume of deproteinized plasma and obtain resolution of drug enantiomers with high sensitivity. The optimum mobile phase, including a non-volatile buffer such as phosphate buffer, for separation of drugs from a large amount of endogenous compounds can be used, because of inclusion of a trapping column with a desalting function. This method is very simple and rapid, and should be very powerful in studies requiring high-sensitivity analysis with chiral separation of drugs from biological samples such as plasma.

Chromatography, High Pressure Liquid↗
PubMed1994

A clinicopathological evaluation of nucleolar organizer region proteins in human breast carcinoma.

The number of nucleolar organizer region proteins (NORs) identified by silver staining (Ag) was studied in 106 primary breast carcinomas. The AgNOR score (mean +/- SD) in tumours smaller than 2 cm was significantly lower than that in tumours larger than 2 cm (P < 0.05). However, there was no significant difference according to other clinicopathological characteristics. According to postoperative distant recurrence, the AgNOR count was significantly higher in the group with recurrence than in the group without recurrence (P < 0.05). Further, the survival rate was significantly lower in the high AgNOR score (> or = 3) group than in the low score (< 3) group (P < 0.01). The present study indicates that the AgNOR score in human breast cancer cells is useful for evaluating cell proliferative activity and may help predict postoperative distant recurrence and, ultimately, the postoperative prognosis of patients.

Adult↗
PubMed1994

The extent and number of metastatic lymph nodes limit the efficacy of lymphadenectomy in patients with oesophageal carcinoma.

The extent and number of metastatic lymph nodes in 52 patients with oesophageal carcinoma involving more than one lymph node were analysed to determine the efficacy of lymphadenectomy. The patients were divided into two groups according to the number of metastatic lymph nodes, group A: 1-4 nodes (34 cases) and group B: 5 or more nodes (18 cases). The survival of all patients in group A was statistically better than that of the patients in group B (P = 0.02). In cases where metastatic nodes were restricted to one region, the survival of patients in group A was significantly better than that of patients in group B (P = 0.006). By contrast, in cases where metastatic nodes extended to two or more regions, there was no difference between the groups. The present study suggests that lymphadenectomy is effective only for patients with 1-4 metastatic nodes that are restricted to a single region. Lymphadenectomy is less efficacious in cases with five or more metastatic nodes, even when the nodes are restricted to one region, and is similarly ineffective in cases with metastatic nodes extending to two or more regions, regardless of the number of positive nodes.

Adult↗
PubMed1994

A comparative study on hepatocellular carcinoma between South Africans and Japanese from the viewpoint of nuclear DNA content.

Nuclear deoxyribonucleic acid (DNA) content of hepatocellular carcinoma (HCC) in 41 South African and 47 Japanese patients at autopsy was analysed by dual-wavelength microspectrophotometry. The DNA distribution patterns were classified as type I, II, III or IV and as low ploidy (types I, II) or high ploidy (types III, IV), according to the degree of dispersion. We found a significantly higher incidence of high ploidy in South African HCC than in Japanese HCC. Moreover, type IV was significantly more frequent among South Africans than among the Japanese. These findings demonstrate that large differences in biological characteristics and clinical behaviour of HCC between South Africa and Japan may reflect differences in DNA distribution patterns which we observed between these two races.

Adolescent↗
PubMed1994

Serum lidocaine and MEGX concentrations after pharyngeal anesthesia for gastroscopy.

In 20 patients undergoing topical anesthesia for gastroscopic examination, serum concentrations of lidocaine and its metabolite, monomethylglycinexylidide (MEGX), were measured. Patients were divided randomly into two groups: a gel group, in which 5 ml of 2% lidocaine gel was applied to the throat for 20 minutes; and a solution group, in which 40 ml of 2% lidocaine solution was administered by gargling for five minutes. The effect of oropharyngeal anesthesia was comparable in both groups. In the gel group, the serum levels of lidocaine and MEGX were not elevated at 15 minutes after application of the anesthetic. However, in the solution group, a rise in both serum lidocaine and MEGX at 15 minutes after anesthesia was detected in some of the patients (40%). Increased serum MEGX concentrations, which correlated well with serum lidocaine concentrations, were associated with the age of the patient (r = 0.606; p < 0.05), but not with height or weight. As a topical anesthetic for endoscopic examination, we prefer lidocaine gel to lidocaine solution, because the latter might be absorbed more rapidly and unpredictably in some, especially aged patients.

Adult↗
PubMed1994

A newly developed fine-caliber endoscope for peroral cholangiopancreatoscopy.

We have developed a new fine-caliber (2.09 mm outer diameter) endoscope for peroral cholangiopancreatoscopy. The endoscope contains one image transmission fiber, 12 light guide fibers (the transmitter of light from the light source) and a working channel (a lumen for the guide wire and rinsing). The working channel, whose bore is 0.72 mm, is located centrally within the endoscope. The endoscope can be introduced reliably into the bile and pancreatic ducts using the same techniques as those for endoscopic nasobiliary drainage through the instrumental channel of a duodenoscope for examination without pretreatment of the papilla of Vater. Two patients with lesions of the pancreatic duct and seven patients with lesions of the bile duct suspected or detected by endoscopic retrograde cholangiopancreatography (ERCP) were examined. Direct inspection of the biliopancreatic duct not only provided enough information to make a definite diagnosis, but also revealed lesions that were not detectable by ERCP or other examinations.

Adult↗
PubMed1994

Morphological and physicochemical changes in the myosin molecules induced by hydrostatic pressure.

Hydrostatic pressure-induced morphological and physiochemical changes in monomeric myosin were investigated. The turbidity of a myosin solution increased after release of pressure, indicating aggregation of the molecules. Some molecules were single headed after exposure to 100-200 MPa, in contrast with an intact molecule having two heads. Small-sized oligomeric species, composed of several molecules, appeared after pressurization at 200 MPa. The oligomers were formed only through head-to-head association. Neither head-to-tail nor tail-to-tail interaction was observed. With increasing pressure to 300 MPa, monomeric myosin remarkably decreased, and most molecules formed oligomers, in which the myosin heads were tightly associated, forming a clump, the tails of the myosin molecules extending radially from the clump. Such an oligomer was shaped like a daisy wheel and its morphology was quite similar to that formed on heating reported previously [Yamamoto et al. (1990) J. Biochem. 108, 896-898]. The aggregation of myosin molecules upon pressurization was concomitant with an increase in hydrophobicity, which was measured spectrofluorometrically with 8-anilino-1-naphthalene sulfonate, a probe for apolar binding sites. Although the turbidity increased continuously with increasing pressure, the hydrophobicity remained at a constant level above 200 MPa at pH 6.0 and above 300 MPa at pH 7.0. The loss of myosin ATPase activity was accompanied by aggregation of the molecules. These results indicate that hydrophobic groups in the heads of myosin are exposed to the surface of the molecule on pressurization, so that hydrophobic interaction among the heads occurs, yielding aggregates. Beside the hydrophobic interaction, the contribution of other interaction(s) is also suggested.

Chemical Phenomena↗
PubMed1994

Enzyme release from mitochondria during reoxygenation of rat liver.

Reoxygenation-induced release of mitochondrial aspartate aminotransferase (mAST) into the cytosol was studied using perfused rat liver. As the absolute activity of mAST in the perfusate did not indicate the degree of mitochondrial enzyme release, the following 3 methods were applied: measurement of the mAST to total AST ratio in the efferent perfusate, the digitonin infusion method, and measurement of mAST activity in the cytosolic compartment isolated from perfused livers. The results by all 3 methods were consistent and showed that mitochondrial injury occurs on reoxygenation. The mitochondrial Ca2+ content was proportional to the extent of mAST release during reoxygenation, indicating involvement of Ca2+ in the enzyme release. CsA, a potent inhibitor of Ca(2+)-induced increase in permeability of the mitochondrial membrane, completely prevented mAST release on reoxygenation. We conclude that during reoxygenation of hypoxic liver, mAST leaks into the cytosol in a Ca(2+)-dependent, CsA-sensitive manner.

Animals↗
PubMed1994

An aggressive spindle cell squamous carcinoma arising in a patient with long-standing erythroderma.

Spindle cell squamous carcinoma (SCSC) of the left hand arising in a patient with long-standing erythroderma is reported. Histopathologically, spindle shaped atypical cells were observed neighboring the cells of well differentiated squamous cell carcinoma. These two types of tumor cells, spindle cells and well differentiated cells, were present side by side and merged into each other. The erythroderma had been present for over 20 years, and both clinical and histopathological findings suggested cutaneous T cell lymphoma, but were not diagnostic for mycosis fungoides, Sézary syndrome, or adult T cell lymphoma. Flow cytometry of peripheral blood cells showed a low CD4/CD8 ratio which suggested impaired T cell function. Multiple metastases of SCSC occurred in a short period and the patient died ten months after his first visit to us. The aggressive course of this case was unusual, and may be due to immunological abnormalities associated with the long standing erythroderma with impaired T cell function.

Aged↗
PubMed1994

Effects of combined treatment with phenolic compounds and sodium nitrite on two-stage carcinogenesis and cell proliferation in the rat stomach.

The effects of combined treatment with NaNO2 and phenolic compounds on N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) stomach carcinogenesis were investigated in F344 rats. In the first experiment, groups of 15-20 male rats were treated with an intragastric dose of 150 mg/kg body weight of MNNG, and starting 1 wk later, were given 2.0% butylated hydroxyanisole, 0.8% catechol, 2.0% 3-methoxycatechol or basal diet either alone or in combination with 0.2% NaNO2 in the drinking water until they were killed at week 52. All three antioxidants significantly enhanced forestomach carcinogenesis without any effect of additional NaNO2 treatment. However, in the absence of MNNG pretreatment, the grade of forestomach hyperplasia in the catechol and 3-methoxycatechol groups was significantly increased by the combined treatment with NaNO2. In a second experiment, the combined effects of various phenolic compounds and NaNO2 on cell proliferation in the upper digestive tract were examined. Groups of 5 rats were given one of 24 phenolic compounds or basal diet either alone or in combination with 0.3% NaNO2 for 4 weeks and then killed. Particularly strong enhancing effects in terms of thickness of the forestomach mucosa were seen with t-butylhydroquinone (TBHQ), catechol, gallic acid, 1,2,4-benzenetriol, dl-3-(3,4-dihydroxyphenyl)-alanine and hydroquinone in combination with NaNO2. In the glandular stomach, similar enhancing effects were evident in 11 cases, and in the esophagus with phenol, TBHQ and gallic acid. These results demonstrate that NaNO2 can augment cell proliferation induced in the stomach epithelium by various phenolic compounds.

Animals↗
PubMed1994

Prognostic significance of p53 and ras gene abnormalities in lung adenocarcinoma patients with stage I disease after curative resection.

We investigated the prognostic significance of p53 gene abnormalities and ras gene mutations in patients with curatively resected stage I lung adenocarcinoma. Formalin-fixed and paraffin-embedded tissues were obtained from 30 patients who had undergone curative resection for stage I lung adenocarcinoma. Abnormalities of the p53 gene were detected using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) analysis and immunohistochemistry and ras mutations were detected using PCR-restriction fragment length polymorphism (RFLP) analysis. Both univariate and multivariate analyses were performed to assess the relationship between the presence of abnormalities of these genes and the patients' disease-free survival. Eleven tumors (37%) had mutated p53 sequences and 11 (37%) showed p53 overexpression. A total of 15 tumors (50%) had p53 gene abnormalities and the concordance rate was 73%. Seven tumors (23%) showed mutated ras sequences. The univariate analysis revealed that the disease-free survival of patients with any p53 abnormality was shorter than that of those without abnormalities (P = 0.02, generalized Wilcoxon test), and survival of those with p53 protein overexpression was more significantly shorter (P = 0.003, generalized Wilcoxon test). Multivariate analysis using the Cox proportional hazards model indicated that the presence of p53 abnormalities was a significantly (P = 0.01) unfavorable prognostic factor. There was no significant correlation between the presence of ras mutation and survival. These results suggest that analysis of the p53 gene may be helpful for the selection of high-risk patients for clinical trials of adjuvant therapy for stage I lung adenocarcinoma.

Adenocarcinoma↗
PubMed1994

Acute myeloid leukaemia with t(9;11)(p22;q23) in a patient treated for adult T cell leukaemia.

A 37-year-old male patient with adult T cell leukaemia (ATL) began receiving chemotherapy in March 1992. He achieved complete remission in May 1992, but developed acute myeloid leukaemia (AML, FAB subtype M2) with t(9;11)(p22;q23) in May 1993. The presence of chromosome 11 abnormality at band 11q23 in this patient suggests that the AML was related to the chemotherapy with etoposide for ATL. Furthermore, the combination of etoposide with two cytostatic drugs, cyclophosphamide and carboplatin, possibly induced the leukaemia early (14 months) after the start of chemotherapy. To our knowledge, this is the first report of therapy-related AML after chemotherapy for ATL.

Adult↗
PubMed1994

Establishment and characterization of a novel myeloid cell line from the bone marrow of a patient with the myelodysplastic syndrome.

A novel long-term cultured myeloid cell line was established from the bone marrow of a patient with myelodysplastic syndrome (MDS). This cell line, designated MDS92, proliferated in the presence of interleukin-3 or granulocyte-macrophage colony-stimulating factor and transiently in the presence of Steel factor, with a tendency for gradual maturation, and formed myeloid colonies in the semi-solid culture condition. In addition, the MDS92 cell line represented rather complicated karyotypic abnormalities including the deletion of fifth and seventh chromosomes and a point mutation at codon 12 of the N-ras oncogene. These characteristics of the MDS92 cell line are exclusively compatible with the property of preleukaemia.

Anemia, Sideroblastic↗