Biomedical subjects

K Yoneyama

Publications and source records attributed to K Yoneyama.

At least 19 recordsLinked to original sources

PubMed2001

Prognosis of patients with advanced carcinoma of the esophagus with complete response to chemotherapy and/or radiation therapy: a questionnaire survey in Japan.

BACKGROUND: We estimated the survival of patients with advanced carcinoma of the esophagus in Japan who achieved complete response (CR) with chemotherapy and/or radiation therapy. METHODS: A questionnaire was designed for patients with cancer of the esophagus with pretreatment stage II-IV (excluding organ metastasis [M1]), who were treated with chemotherapy and/or radiation therapy and achieved either a clinical CR continuing for more than 1 year, or a pathological CR in surgical specimens. All patients were treated between January 1, 1990, and December 31, 1997, in Japan. RESULTS: Of the 169 eligible patients for whom adequate data were available, 106 patients with continuing clinical CR were defined as group A and 63 with pathological CR as group B. The overall survival rates at 5 years were 62.4% in group A and 64.8% in group B. In each of groups A and B, there was no significant difference in overall survival among subgroups of patients classified by initial pretreatment clinical stage. In group A, the survival rate of patients with concurrent chemotherapy and radiation therapy was significantly better than the rates for patients with chemotherapy alone or radiotherapy alone. In group A, the frequency of first failure at the local site of esophageal carcinoma was 7.7%. Of the 12 patients in group B (19%) who died less than 1 year postoperatively, 6 died of postoperative complications. CONCLUSION: The effect of CR to chemotherapy and/or radiation therapy for carcinoma of the esophagus on survival was marked. In patients with esophageal carcinoma who achieve CR, the prognosis may be independent of the initial pretreatment stage. Local failure in group A patients remains a problem, however.

Adult↗

PubMed2001

A specific brassinosteroid biosynthesis inhibitor, Brz2001: evaluation of its effects on Arabidopsis, cress, tobacco, and rice.

Brassinazole is the only known specific brassinosteroid (BR)-biosynthesis inhibitor, and it has been shown to be useful for elucidating the function of BRs. In the course of a structure-activity relationship study of brassinazole, we found a more specific BR-biosynthesis inhibitor, Brz2001. This new inhibitor induced similar morphological changes to those seen in brassinazole-treated plants, including Arabidopsis thaliana (L.) Heynh., Nicotiana tabacum L., and Lepidium sativum L. These changes included dwarfism with altered leaf morphology, including downward curling and dark-green color, and the changes were reversed by brassinolide. Although the structure of Brz2001 is similar to that of uniconazole, a gibberellin-biosynthesis inhibitor, Brz2001-treated plants showed almost no recovery with the addition of gibberellic acid (GA3). Comparison of the responses of both brassinazole- and Brz2001-treated cress to brassinolide and GA3 suggested that Brz2001 is a more specific BR-biosynthesis inhibitor than brassinazole. Unlike the results just described, Brz2001-treated rice did not show any morphological changes. This suggests that the roles of BRs in rice may be different from those in the dicotyledonous plants examined in this study. Brz2001 can be used to clarify the function of BRs in dicots as a complement to BR-deficient mutants, and to elucidate the different roles of BRs in monocots and dicots.

Arabidopsis↗

PubMed2001

Gene fusion involving HMGIC is a frequent aberration in uterine leiomyomas.

HMGIC, a high-mobility-group protein gene encoding an architectural transcription factor, was recently identified as the target of gene fusion in a variety of human benign mesenchymal tumors; some of these events were chromosomal translocations involving 12q13-15. HMGIC consists of three DNA-binding domains (encoded by exons 1-3), a spacer, and an acidic carboxyl-terminal regulatory domain (exons 4-5). To determine the spectrum and nature of the aberrations in uterine myomas in Japanese patients, we systematically examined the tumors of 45 patients for all possible types of gene fusions involving HMGIC, by means of 3'-rapid amplification of cDNA ends (RACE) and reverse transcriptase-polymerase chain reaction (RT-PCR) experiments. HMGIC gene fusions were found in 16 (36%) of the tumors; aberrant splicings to five cryptic sequences located in introns of the HMGIC gene were found in 11 of these cases, and translocations causing juxtaposition to other genes, such as COX6C and RA D51B, were found in 5. In all fusion transcripts, the first two or three exons of HMGIC were fused to ectopic sequences. Our results suggest that a fusion event, resulting in the separation of the DNA-binding domains of HMGIC from the spacer and the acidic carboxyl-terminal regulatory domain, is a common tumorigenic mechanism in the development of uterine myomas.

Alternative Splicing↗

PubMed2001

Clinical significance of TT virus in chronic hepatitis C.

BACKGROUND AND AIMS: Much is still unknown about the clinical significance of TT virus (TTV), which has been reported as a candidate for non A-G hepatitis virus. The aim of this study was to clarify the clinical significance of TTV in patients coinfected with TTV and hepatitis C virus (HCV). METHODS: The 95 subjects studied had chronic hepatitis C (CHC), and underwent interferon (IFN) therapy. TT Virus DNA was detected by using polymerase chain reaction. The nucleotide sequences were determined by using a dideoxy chain termination method. A phylogenetic tree was drawn up by using the neighbor-joining method. RESULTS: TT Virus DNA was detected in 37.9% of patients with the use of an open reading frame 1 (ORF1) primer, and in 88.4% of patients by using a 5' untranslated region (5' UTR) primer. Using both sets of primers, no differences were found between TTV-DNA-positive and -negative subjects with CHC in the clinical findings. Serum TTV DNA was eradicated in 30.6% of patients with the ORF1 primer, and in 19.1% of patients with the 5' UTR primer at 6 months after the cessation of IFN therapy. The levels of TTV DNA before IFN therapy were significantly lower in the viral eradication group than in non-eradication group. The changes in alanine aminotransferase (ALT) concentrations were significantly correlated with changes in HCV-RNA in CHC patients with TTV. Moreover, there was no correlation between the changes in TTV DNA and the course of ALT. CONCLUSION: Hepatocellular injury in patients with chronic hepatitis who are coinfected with HCV and TTV appears to primarily be caused by HCV and is less attributable to TTV.

Adult↗

PubMed2001

Characterization of PBZ1, a probenazole-inducible gene, in suspension-cultured rice cells.

Probenazole (PBZ) induces non-race specific resistance in rice plants against rice blast fungus and PBZ1 was identified as a PBZ-inducible gene from rice. The induction of PBZ1 expression in suspension-cultured rice cells was investigated. Northern blot analysis indicated that PBZ1 was induced by PBZ in a dose-dependent manner. Enzyme-linked immunosorbent assay (ELISA) showed a dose and time-dependent accumulation of PBZ1 protein. Both mRNA and protein analysis showed that PBZ1 was not induced by salicylic acid or an active metabolite, 1,2-benzisothiazole-1,1-dioxide.

Cell Line↗

PubMed2000

Novel gene fusion of COX6C at 8q22-23 to HMGIC at 12q15 in a uterine leiomyoma.

Cytogenetic analyses have shown that aberrations involving 12q13-15 are frequent chromosomal changes in a variety of human benign mesenchymal tumors, e.g., pleomorphic adenomas of the parotid gland, pulmonary chondroid hamartomas, lipomas, and uterine leiomyomas. Recently, the high-mobility group protein gene HMGIC was identified as the target gene affected by the 12q13-15 aberrations. Using 3' rapid amplification of cDNA ends experiments, we isolated novel ectopic sequences fused to HMGIC in a uterine leiomyoma. Cloning of the fusion cDNA identified the human cytochrome c oxidase subunit VIc (COX6C) gene on 8q22-23 as the fusion partner of HMGIC. Nucleotide sequences of the fusion transcript revealed that the first 3 exons of the HMGIC gene, encoding the 3 DNA binding domains, was fused to the exon 2 of the COX6C gene. The identification of a gene rearrangement suggests a role for HMGIC in tumorigenesis of uterine leiomyoma and suggests a possible involvement of HMGIC in mesenchymal differentiation. Genes Chromosomes Cancer 27:303-307, 2000.

Chromosomes, Human, Pair 12↗

PubMed2000

Iatrogenic GB virus C/hepatitis G virus infection in an area endemic for hepatitis C virus.

GB virus C/hepatitis G virus (GBV-C/HGV) is reported to be transmitted by blood products. This study reports infection with GBV-C/HGV from Area-O of town T, an area of high prevalence of antibody to hepatitis C virus (anti-HCV). Four hundred and thirty-five inhabitants of Area-O in town T were examined. Three hundred and forty-three inhabitants of Area-H in town T (where differences of age or sex are not markedly different to Area-O) were studied as controls. We investigated the virus markers and conducted a survey of life history in both areas. The seroprevalence of anti-HCV and GBV-C/HGV markers in Area-O was 17.7% and 11.7%, significantly higher than in Area-H (1.5% and 4.4%). The prevalence of GBV-C/HGV markers was significantly higher in the anti-HCV-positive group than in the sero-negative group. Anti-HCV- or GBV-C/HGV positive subjects tended to have a history of intravenous medications at hospital C in town T, suggesting iatrogenic infection through insufficient sterilization of needles and/or syringes.

Adult↗

PubMed2000

B-cell-type malignant lymphoma with placental involvement.

We present here a case of B-cell-type mediastinal malignant lymphoma during pregnancy complicated by placental involvement. In this case, some nodular high-echo patterns were recognized in the placenta by ultrasonography. A cesarean section and resection of the mediastinal tumor were performed at 33 weeks and 6 days of gestation due to the deterioration of the dyspnea. A female infant weighing 1,868 g was delivered and she is now a healthy 2-year-old. The mother, however, died of the disease 1 month after surgery, due to progression of the tumor. The placenta showed numerous white firm nodules varying from 3 mm to 3 cm in diameter. The pathologic findings of both the mediastinal tumor and the placenta indicated primary mediastinal (thymic) B-cell lymphoma.

Adult↗

PubMed2000

[Change in maternal bone mineral density during pregnancy and relationship between the density and foetus growth--a prospective study].

In order to study change in maternal bone mineral density during pregnancy and its relationships with bone metabolism and maternal perinatal factors including foetus growth, bone mineral density and bone metabolic markers were measured in 45 pregnant women aged 26-35 years. Specifically, bone mineral density was measured twice, first at 8-20 weeks of gestation and secondly within two weeks postpartum by ultrasonic bone densitometry, while bone metabolic markers were assessed at 8-20 and 26-30 weeks of gestation and at one week postpartum. Bone mineral density and metabolic markers were also examined in 35 non-pregnant controls, twice with a six-month interval. The results of the measurements and subsequent examinations based thereon were as follows: 1. Stiffness as an index of bone density decreased significantly during pregnancy (mean: -4.3%), with wide variation among individuals (-20%-(+)11%). Stiffness in controls did not show any significant change within the 6 months. 2. During pregnancy, bone alkaline phosphatase and osteocalcin levels were significantly lower while urinary hydroxyproline levels (H.P/Cre) were significantly higher than in controls. Significant negative correlations were found between change rate in stiffness and HP/Cre measured at second trimester and postpartum. These results indicate that bone formation is reduced while bone resorption is increased during pregnancy, and that stiffness index reflects the extent of bone resorption. 3. Pre-pregnancy BMI and weight gain during pregnancy could not be linked with change in bone mineral density. 4. The women with greater bone density demonstrated a greater extent of loss postpartum. 5. Postpartum bone mineral density showed a significant, positive correlation with baby birth weight and height. Higher preservation of maternal bone mass is important not only for the mother's health but also for the baby's. Ultrasonic bone densitometry was found to be useful for measuring bone mineral density because it could detect small changes during pregnancy reflecting bone metabolism.

Adult↗

PubMed1999

Postoperative complications in patients of esophageal cancer after neoadjuvant chemotherapy.

We examined the effects of neoadjuvant chemotherapy on surgery by evaluating postoperative complications in 50 patients who had undergone neoadjuvant chemotherapy (Group A) and in 108 patients who had undergone surgery without neoadjuvant chemotherapy (Group B). Toxicity of grade 3 by chemotherapy were WBC in 3 patients (6%), alopecia in 3 patients (6%), and anorexia in 22 patients (44%). There were 4 patients with anastomotic leakage (8%) (all in minor), 5 patients with infection of wound (10%), 6 patients with arrhythmia (12%), no patients with postoperative bleeding, 2 patients with respiratory complications (4%), and no patients who died due to complications in Group A. In Group B, there were 13 patients with anastomotic leakage (13%) (all in minor), 12 patients with infection of the wound (11%), 11 patients with arrhythmia (10%), 2 patients with postoperative bleeding (2%), 8 patients with respiratory complications (7%), and 2 patients who died due to complications (2%). There was no significant difference in the incidence of postoperative complications between the patients who had undergone surgery after neoadjuvant chemotherapy, such as CDDP + 5FU therapy and FAP therapy, and the patients who had undergone surgery without neoadjuvant chemotherapy, in patients who had been diagnosed as being able to undergo relative non-curative resection or better, who had Ccr 60 ml/min or more and no severe complication, and whose stomach could be used for reconstruction of the esophagus, on the condition that surgery would be performed on NC patients at the end of first-course treatment.

Alopecia↗

PubMed1999

GB virus C infection: clinical significance.

GB virus C (GBV-C) RNA positivity rates were examined in serum specimens from 231 patients with liver disease (23 patients with hepatitis B, 175 patients with hepatitis C, five patients with hepatitis B virus plus hepatitis C virus coinfection, and 28 patients with non-A, non-B, non-C hepatitis) to clarify the clinical significance of this virus. GBV-C RNA was detected in none of 12 patients with fulminant hepatitis, one of two patients with acute hepatitis positive for hepatitis B surface antigen and one of four patients with acute non-A, non-B, non-C hepatitis. Pathogenetic involvement of GBV-C was suspected in some patients in the latter group. Among patients with the non-B, non-C type of chronic disease, one of seven with cirrhosis (14%) and none with chronic hepatitis or hepatocellular carcinoma were GBV-C-positive. In chronic hepatitis C patients who had received interferon treatment, no difference was found in clinical findings, alanine aminotransferase (ALT) concentrations, histology or response to interferon between 11 patients who were GBV-C RNA-positive and 101 patients who were GBV-C RNA-negative. Moreover, changes in ALT after interferon therapy showed no relation to positivity for GBV-C RNA. On the basis of these findings, GBV-C appears to be an unlikely cause of initiation or progression of chronic hepatic diseases.

Adult↗

PubMed1999

The trichothecene biosynthesis regulatory gene from the type B producer Fusarium strains: sequence of Tri6 and its expression in Escherichia coli.

A genomic DNA fragment containing Tri6, a transcription activator gene of trichothecene biosynthesis, was cloned by vectorette PCR from Fusarium graminearum F15, which produces type B trichothecene, deoxynivalenol. The nucleotide sequence of the gene showed 84% of identity to that of the type A trichothecene producer Fusarium sporotrichioides NRRL 3299, but the sequence around the initiation codon was not highly conserved between these producers. Based on the upstream and downstream sequences of the coding region of F. graminearum, Tri6 could be amplified by PCR from other type B trichothecene producers. Tri6 appeared to be expressed for only a limited period prior to the toxin production.

Amino Acid Sequence↗

PubMed1999

Primary biliary cirrhosis associated with membranous glomerulonephritis.

A 33-year-old woman was admitted to our department for evaluation of liver dysfunction and proteinuria. A liver biopsy specimen showed ductular proliferation and moderate portal fibrosis indicating stage II primary biliary cirrhosis. A renal biopsy specimen showed mild to moderate mesangial cell proliferation without crescent formation or interstitial nephritis. Immunofluorescent staining revealed deposition of immunoglobulin G (IgG), third component of complement (C3), and Clq on glomerular basement membranes. The findings indicated stage I membranous glomerulonephritis. Administration of ursodesoxycholic acid together with prednisolone, azathioprine, and dipyridamole decreased proteinuria and improved cholestatic liver dysfunction.

Adult↗

PubMed1999

[A case of Morgagni's foramen hernia difficult to differentiate from lipoma].

A 61-year-old woman was admitted for chest discomfort. She had been admitted before, in March 1995, because of a lesion detected on chest roentgenograms. At that time, she was given a diagnosis of mediastinal lipoma based on the findings of chest computed tomography (CT) and magnetic resonance imaging (MRI), but was discharged without active intervention due to lack of subjective symptoms. During follow-up, the patient again reported chest discomfort beginning in March 1998. Because chest radiography disclosed. The tumor had enlarged, the patient was admitted to the hospital by our department. Chest MRI disclosed a mass with a signal intensity equal to that of subcutaneous fat in the pericardial space on both T1-weighted and T2-weighted images. Although sagittal images demonstrated continuity of the mass into intraperitoneal fat, a conclusive diagnosis of diaphragmatic hernia could not be made at that time. On April 30, 1998, a thoracotomy was performed on the basis of a preoperative diagnosis of mediastinal lipoma. During surgery, a hernial ring was observed slightly to the right and behind the sternum. The hernia consisted only of greater omentum, and was diagnosed as Morgagni's foramen hernia.

Diagnosis, Differential↗

PubMed1998

The mystery of the trichothecene 3-O-acetyltransferase gene. Analysis of the region around Tri101 and characterization of its homologue from Fusarium sporotrichioides.

The trichothecene 3-O-acetyltransferase gene, Tri101, plays a pivotal role for the well-being of the type B trichothecene producer Fusarium graminearum. We have analyzed the cosmids containing Tri101 and found that this resistance gene is not in the biosynthetic gene cluster reported so far. It was located between the UTP-ammonia ligase gene and the phosphate permease gene which are not related to trichothecene biosynthesis. These two 'house-keeping' genes were also linked in Fusarium species that do not produce trichothecenes. The result suggests that the isolated occurrence of Tri101 is attributed to horizontal gene transfer and not to the reciprocal translocation of the chromosome containing the gene cluster. Interestingly, 3-O-acetylation was not always a primary self-defensive strategy for all the t-type trichothecene producers; i.e. the type A trichothecene producer Fusarium sporotrichioides did not acetylate T-2 toxin in vivo although the fungus possessed a functional 3-O-acetyltransferase gene. Thus Tri101 appears to be a defense option which the producers have independently acquired in addition to their original resistance mechanisms.

Acetyltransferases↗

PubMed1998

Trichothecene 3-O-acetyltransferase protects both the producing organism and transformed yeast from related mycotoxins. Cloning and characterization of Tri101.

Trichothecene mycotoxins such as deoxynivalenol, 4,15-diacetoxyscirpenol, and T-2 toxin, are potent protein synthesis inhibitors for eukaryotic organisms. The 3-O-acetyl derivatives of these toxins were shown to reduce their in vitro activity significantly as assessed by assays using a rabbit reticulocyte translation system. The results suggested that the introduction of an O-acetyl group at the C-3 position in the biosynthetic pathway works as a resistance mechanism for Fusarium species that produce t-type trichothecenes (trichothecenes synthesized via the precursor trichotriol). A gene responsible for the 3-O-acetylation reaction, Tri101, has been successfully cloned from a Fusarium graminearum cDNA library that was designed to be expressed in Schizosaccharomyces pombe. Fission yeast transformants were selected for their ability to grow in the presence of T-2 toxin, and this strategy allowed isolation of 25 resistant clones, all of which contained a cDNA for Tri101. This is the first drug-inactivating O-acetyltransferase gene derived from antibiotic-producing organisms. The open reading frame of Tri101 codes for a polypeptide of 451 amino acid residues, which shows no similarity to any other proteins reported so far. TRI101 from recombinant Escherichia coli catalyzes O-acetylation of the trichothecene ring specifically at the C-3 position in an acetyl-CoA-dependent manner. By using the Tri101 cDNA as a probe, two least overlapping cosmid clones that cover a region of 70 kilobase pairs have been isolated from the genome of F. graminearum. Other trichothecene biosynthetic genes, Tri4, Tri5, and Tri6, were not clustered in the region covered by these cosmid clones. These new cosmid clones are considered to be located in other parts of the large biosynthetic gene cluster and might be useful for the study of trichothecene biosynthesis.

Acetylation↗

PubMed1998

Features of Tri101, the trichothecene 3-O-acetyltransferase gene, related to the self-defense mechanism in Fusarium graminearum.

A structural gene of Tri101, which encodes trichothecene 3-O-acetyltransferase, was isolated as a 3-kb XhoI-XbaI fragment from the trichothecene producer Fusarium graminearum strain F15. The gene contained no introns, and the coding region was 0.7-kb downstream of a putative UTP-ammonia ligase gene which obviously is not related to the biosynthesis of trichothecenes. Tri101 was expressed when T-2 toxin was added, but this induction was not dependent on the expression level of Tri6, a transcription activator gene in the trichothecene biosynthetic and regulatory gene cluster.

Acetyltransferases↗

PubMed1998

Giant hepatic biloma following transcatheter oily chemoembolization in a patient with hepatic metastases from malignant pheochromocytoma.

A 48-year-old woman developed hepatic metastases from malignant pheochromocytoma resected 8 years previously. Angiography revealed multiple tumor stains in the liver. Transcatheter oily chemoembolization using styrenomaleic acid neocarzinostatin and iodized oil was performed. The patient complained of severe right upper quadrant pain immediately following the transcatheter oily chemoembolization. Necrotizing cholecystitis developed on the 4th day post-transcatheter oily chemoembolization, hepatic infarction on the 12th day, and a biloma on the 19th day. Despite the administration of antibiotics and percutaneous transhepatic drainage, neither the volume of drainage nor the size of the biloma decreased. Biliary reconstruction was performed using a metallic stent, which decreased the size of the biloma.

Adrenal Gland Neoplasms↗