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Biomedical subjects

M Tani

Publications and source records attributed to M Tani.

At least 91 records · Page 5Linked to original sources
PubMed1999

Underpants-pattern erythema: a previously unrecognized cutaneous manifestation of extramammary Paget's disease of the genitalia with advanced metastatic spread.

BACKGROUND: A previously unrecognized erythema was noted in 6 patients with extramammary Paget's disease (EMPD) of the genitalia with metastases. It was distinct from essential erythema of EMPD and has not been reported before. OBJECTIVE: Our purpose was to describe the clinical and histopathologic features of the erythema and clarify its pathogenesis and prognostic importance. METHODS: A review of the clinical records and histologic materials of 6 cases was made focusing on the clinical features of this unique erythema as well as the course and prognosis of the patients. RESULTS: The erythema first appeared in the inguinal region and extended centrifugally to an area normally covered by underpants. Histopathologic examination showed lymphatic infiltration by cancer cells of the skin. All of the patients with this "underpants-pattern erythema" died of the disease, and the mean survival period after its appearance was 13 months. CONCLUSION: Underpants-distribution erythema may be a sign of advanced stage EMPD.

Aged↗
PubMed1999

Mutation and expression of the p51 gene in human lung cancer.

A newly identified gene, p51, is a functional and structural homologue of the p53 gene and thus a Candidate tumor suppressor gene. To elucidate the role of the p51 gene in lung carcinogenesis, we determined the sequences of exon-intron boundaries and the 5'- and 3'-flanking regions of all the 15 coding exons and performed a mutation analysis, as well as detailed analysis for gene expression. A frameshift mutation was detected in 1 of 44 lung cancer cell lines, whereas no mutation was detected in 45 primary lung cancers. Thus, p51 mutation occurs only in a small subset of lung cancer. Expression of the p51 gene was detected in 23 of 43 cell lines by Northern blot analysis and 34 of 44 by reverse transcriptase-polymerase chain reaction (RT-PCR) analysis. Thus, p51 expression is low or absent in a subset of lung cancer. The deltaN isotype of p51 transcripts was dominantly expressed in several cell lines, particularly in cell lines with high levels of p51 expression. Because the deltaN isotype encodes a protein that transdominantly suppresses the transactivation function of the TA type of p51, it is possible that p51 protein is not functionally active, even in lung cancer cells with p51 mRNA expression, due to expression of dominant-negative p51 protein. These results suggested that the p51 gene is inactive in a considerable proportion of lung cancers. RT-PCR analysis also revealed the presence of a novel type of mRNA transcript, p51delta, which lacks exons 12 and 13 by alternative splicing. The delta isotype was expressed in 18 of 44 lung cancer cell lines and in diverse normal tissues. Further analysis on p51 expression in cancerous as well as noncancerous cells will provide us with valuable information for the understanding of multiple functions of the p53 family proteins in human carcinogenesis.

Base Sequence↗
PubMed1999

Long-term administration of cyclosporin A to HCV-antibody-positive patients with dermatologic diseases.

BACKGROUND: Cyclosporine A (CYA) is an immunosuppressive agent which is being used in the treatment of an increasingly wide range of dermatologic diseases, but its use has been avoided in carriers of hepatitis C virus (HCV). METHODS: We administered small doses of CYA (maximum, 3 mg/kg/day) for a long time to treat dermatologic diseases in one HCV-antibody-positive patient with no HCV-RNA in the blood, one patient with a small amount of HCV-RNA in the blood, and two patients with large amounts of HCV-RNA in the blood. RESULTS: Skin lesions improved in all patients, but recurred upon complete or partial withdrawal of CYA. In the absence of HCV-RNA in the blood, or when only a small quantity of HCV-RNA was present in the blood, HCV-RNA load showed no apparent change. In one patient with a large blood HCV-RNA load, CYA dosage reduction was followed by increases in alanine aminotransferase (ALT) levels and decreases in blood HCV-RNA. Aggravation of hepatitis due to immunologic reactivation was suspected in this patient. CONCLUSIONS: The reduction of CYA dosage is a key element in the use of this agent for cutaneous diseases.

Aged↗
PubMed1999

Treatment of esophageal and gastric tumors.

Endoscopic mucosal resection (EMR) has gained increasing popularity in the treatment of esophageal and gastric mucosal cancers in Japan, for complete local resection of the cancer-bearing mucosa. In Western countries, the concept of mucosal cancer and the necessity of treating it are gradually but steadily coming to be accepted. As a treatment for inoperable cases of advanced cancer, on the other hand, intubation with self-expanding metal stents has been widely accepted as a less invasive form of palliation for malignant obstruction of the upper gastrointestinal tract. Tumor ingrowth into the stent can be mechanically avoided by adding a membrane coating to it. In the last two years, applications for therapeutic endoscopy in the treatment of esophageal and gastric tumors have continued to widen.

Adenocarcinoma↗
PubMed1999

Regulation of gamma-glutamylcysteine synthetase expression in response to oxidative stress.

Glutathione (GSH) is synthesized by the activity of two ATP-requiring GSH synthesizing enzymes. Gamma-glutamylcysteine synthetase (gamma-GCS) is the rate limiting enzyme for the GSH synthesis. Gamma-GCS is a heterodimer of heavy, catalytic subunit and light, regulatory subunit and responsive to many stresses, such as heat shock, oxidative stress or cytokines. To know the regulation of the expression of gamma-GCS gene, in the present study, we show evidences that gamma-GCS heavy subunit is upregulated by oxidative stress by ionizing radiation and TNF-alpha mediated by nuclear factor-kappaB (NF-kappaB), and impairment of the expression of gamma-GCS by TNF-alpha in diabetic condition. Furthermore we describe the importance of GSH in the regulation of NF-kappaB subunits.

Animals↗
PubMed1999

Establishment and analysis of biological characteristics of a human duodenal carcinoma cell line, WDC-1.

BACKGROUND: Duodenal carcinoma is very rare and its culture cell lines have rarely been established. METHODS: Tumor cells separated from a surgically resected primary tumor of duodenal carcinoma were put into culture. The patient was an 81-year-old female and had metastatic lymph nodes. We investigated the biological characteristics of the culture cells including in vitro cell kinetics, karyotype, expression of tumor markers and integrins and tumorigenicity and histology in nude mice. RESULTS: A new cell line, designated WDC-1, was established. This duodenal carcinoma cell line proliferated in a monolayered sheet with a doubling time of 50 h. The histological findings of the xenograft in nude mice were similar to those of the primary tumor. WDC-1 cells produced carcinoembryonic antigen and expressed 1 integrin and very late antigen (VLA)-4d in vitro. CONCLUSIONS: A duodenal carcinoma cell line was established, which is rare and may contribute to progress in understanding the biological features of duodenal cancer.

Adenocarcinoma↗
PubMed1999

Specific and sensitive assay for alkaline and neutral ceramidases involving C12-NBD-ceramide.

A fluorescent analogue of ceramide, C12-NBD-ceramide, was found to be hydrolyzed much faster than 14C-labeled ceramide by alkaline ceramidase from Pseudomonas aeruginosa and neutral ceramidase from mouse liver, while this substrate was relatively resistant to acid ceramidase from plasma of the horseshoe crab. The radioactive substrate was used more preferentially by the acid ceramidase. It should be noted that C6-NBD-ceramide, which is usually used for ceramidase assays, was hardly hydrolyzed by any of the enzymes examined, compared to C12-NBD-ceramide. For the alkaline and neutral enzymes, the Vmax and k (Vmax/Km) with C12-NBD-ceramide were much higher than those with 14C-ceramide. In contrast, for the acid enzyme these parameters with C12-NBD-ceramide were less than half those with the radioisotope-labeled substrate. It is noteworthy that the labeling of ceramide with NBD did not itself reduce the Km of the alkaline enzyme, but did that of the neutral enzyme. It was also found that C12-NBD-ceramide was preferentially hydrolyzed by the alkaline and neutral enzymes, but not the acid one, in several mammalian cell lines. This study clearly shows that the attachment of NBD, but not dansyl, increases the susceptibility of ceramide to alkaline and neutral enzyme, and decreases that to acid enzymes. Thus the use of this substrate provides a specific and sensitive assay for alkaline and neutral ceramidases.

4-Chloro-7-nitrobenzofurazan↗
PubMed1999

Preparation of fluorescence-labeled GM1 and sphingomyelin by the reverse hydrolysis reaction of sphingolipid ceramide N-deacylase as substrates for assay of sphingolipid-degrading enzymes and for detection of sphingolipid-binding proteins.

Sphingolipid ceramide N-deacylase is an enzyme capable of hydrolyzing the N-acyl linkages of ceramides of various sphingolipids. Recently, it was found that the enzyme catalyzes the reverse hydrolysis reaction in which free fatty acids are condensed to lyso-sphingolipids to produce sphingolipids. This paper describes a simple method for the synthesis of fluorescence-labeled sphingolipids utilizing the condensation reaction of the enzyme. N-TFAc-aminododecanoic acids were efficiently condensed by the enzyme to the lyso-forms of GM1 and sphingomyelin in glycine buffer (pH 10). The reaction products, N-TFAc-amino-GM1 and sphingomyelin, were obtained with overall yields of 60%. The purified products were identified to be omega-amino-GM1 and omega-amino-sphingomyelin, respectively, by TLC and FAB-MS or ESI-LC/MS analysis after removal of the N-TFAc by mild alkaline treatment. NBD-labeled GM1 and sphingomyelin were prepared from omega-amino-GM1 and omega-amino-sphingomyelin by coupling with 4-fluoro-NBD. These fluorescence-labeled substrates, C12-NBD-GM1 and C12-NBD-sphingomyelin, were hydrolyzed by endoglycoceramidase and sphingomyelinase, respectively, to produce NBD-dodecanoylsphingosines, but were resistant to hydrolysis by sphingolipid ceramide N-deacylase. C12-NBD-sphingomyelin was found to be a better substrate than the commercially available C6-NBD-sphingomyelin for the assay of sphingomyelinase from various sources. We also describe a new method to detect GM1-binding proteins using fluorescence-labeled GM1.

Amidohydrolases↗
PubMed1999

Antitumor effects of interleukin-2 gene-modified fibroblasts in an orthotopic colon cancer model.

We transduced the interleukin-2 (IL-2) gene into murine fibroblasts BALBCL7 or murine colon cancer CT26 using a retroviral vector. BALBCL7 transduced with IL-2 gene secreted 748 pg/ml of IL-2, whereas IL-2 gene-modified CT26 secreted 1,167 pg/ml of IL-2 (48 h incubation, 1x10(6)/ml). Then, we inoculated gene-modified BALBCL7 and/or CT26 cells into BALB/c female mice, and observed the tumor growth. The tumor growth was inhibited in mice inoculated with parental CT26 plus IL-2 gene-modified BALBCL7, compared with that in mice given parental CT26 alone (P<0.01). Moreover, we investigated the cytotoxic activity of spleen cells derived from mice treated with gene-modified cells, and performed phenotypic analysis of the effector cells. The killer cells derived from mice inoculated with IL-2 gene-modified BALBCL7 plus parental CT26 showed higher cytotoxic activity than those from mice inoculated with CT26 alone. The cytotoxic activity was almost completely blocked by anti-CD8 antibody (Ab), and partially blocked by anti-asialo GM1 Ab. Next, we inoculated CT26 tumor tissue into murine cecum orthotopically, and treated the animals with gene-modified BALBCL7 plus parental CT26. The tumor size in the cecum was significantly decreased, compared with parental CT26 alone (P<0.01).

Animals↗
PubMed1999

Expression of specific chemokines and chemokine receptors in the central nervous system of multiple sclerosis patients.

Chemokines direct tissue invasion by specific leukocyte populations. Thus, chemokines may play a role in multiple sclerosis (MS), an idiopathic disorder in which the central nervous system (CNS) inflammatory reaction is largely restricted to mononuclear phagocytes and T cells. We asked whether specific chemokines were expressed in the CNS during acute demyelinating events by analyzing cerebrospinal fluid (CSF), whose composition reflects the CNS extracellular space. During MS attacks, we found elevated CSF levels of three chemokines that act toward T cells and mononuclear phagocytes: interferon-gamma-inducible protein of 10 kDa (IP-10); monokine induced by interferon-gamma (Mig); and regulated on activation, normal T-cell expressed and secreted (RANTES). We then investigated whether specific chemokine receptors were expressed by infiltrating cells in demyelinating MS brain lesions and in CSF. CXCR3, an IP-10/Mig receptor, was expressed on lymphocytic cells in virtually every perivascular inflammatory infiltrate in active MS lesions. CCR5, a RANTES receptor, was detected on lymphocytic cells, macrophages, and microglia in actively demyelinating MS brain lesions. Compared with circulating T cells, CSF T cells were significantly enriched for cells expressing CXCR3 or CCR5. Our results imply pathogenic roles for specific chemokine-chemokine receptor interactions in MS and suggest new molecular targets for therapeutic intervention.

Acute Disease↗
PubMed1999

Prevalence of risk factors for coronary heart disease in a mountain community in northern Italy.

We performed a population survey in the Valle Sabbia mountain community, a highly industrialized area in the province of Brescia, in northern Italy, in order to estimate the prevalence of the main risk factors for coronary heart disease (CHD) among middle-aged men and women. A random sample of 1497 subjects (747 males) aged 40-59 were interviewed and underwent a physical examination. A blood sample was also taken to test total serum cholesterol. Personal histories of hypertension and CHD were given by 20.3 and 4.6% of men, and by 23 and 2.4% of women, respectively. A personal history of diabetes mellitus was reported by 5.2% of men and 4% of women. The mean values of systolic and diastolic blood pressure (SBP and DBP), total cholesterol, number of cigarettes smoked per day and BMI were, respectively: 135.1 and 84.1 mmHg, 219.2 mg/dl, 10.2 cig/day and 26.2 in men, and 136.8 and 83.9 mmHg, 214.3 mg/dl, 2.4 cig/day and 25.1 in women. Among men, 45.0% had SBP > or = 140 or DBP > or = 90, 32.3% had total cholesterol > or = 240 mg/dl, 29.3% were current smokers and 60.7% had a BMI higher than 25. Among women, 48.7% had SBP > or = 140 or DBP > or = 90, 26.0% had total cholesterol > or = 240 mg/dl, 16.8% were current smokers and 44.3% had a BMI higher than 25. When considering the prevalence of high SBP or DBP, high total cholesterol or cigarette smoking, 72.3% of men and 67.7% of women had at least one of the main risk factors for CHD, usually higher values of SBP or DBP, whereas 29.3% of men and 21.2% of women had two or more factors. Overall, prevalences of the most common CHD risk factors in this community were similar to those found in other surveys carried out in Italy in the last decade.

Adult↗
PubMed1999

Identification of human cytochrome P-450 isoforms involved in metabolism of R(+)- and S(-)-gallopamil: utility of in vitro disappearance rate.

Isoforms of cytochrome P-450 (CYP) involved in the metabolism of gallopamil enantiomers were identified by measuring the disappearance rate of parent drug from an incubation mixture with human liver microsomes and recombinant human CYPs. Mean (+/- S.D.) intrinsic clearances (CL(int)) of R(+)- and S(-)-gallopamil in human liver microsomes were 0.320 +/- 0.165 and 0.205 +/- 0.107 ml/min/mg protein, respectively. These values were highly correlated with the 6beta-hydroxylation activity of testosterone, a marker substrate of CYP3A4 (r = 0.977 and 0.900 for R(+)- and S(-)-gallopamil, respectively, p <.001). Ketoconazole and troleandomycin, selective inhibitors of CYP3A4, and polyclonal antibodies raised against CYP3A4/5 markedly reduced the CL(int) of gallopamil enantiomers in human liver microsomes. Among the 10 recombinant human CYP isoforms, CYP3A4 exhibited the highest CL(int) of gallopamil enantiomers, and CYP2C8 and CYP2D6 also exhibited appreciable activity. When the contribution of CYP3A4 to the total metabolic clearance of gallopamil enantiomers in human liver microsomes was estimated by relative activity factor, the mean (+/- S.D.) contributions were 92 +/- 18 and 68 +/- 19% for R(+)- and S(-)-gallopamil, respectively. These values were comparable to the rates of immunoinhibition by antibodies raised against CYP3A4/5 observed in human liver microsomes. The present study suggests that CYP3A4 is a major isoform involved in the overall metabolic clearance of gallopamil enantiomers in the human liver, and that the present approach based on disappearance rate may be applicable to identify major isoforms of CYP involved in the metabolism of a drug in human liver microsomes.

Cytochrome P-450 Enzyme System↗
PubMed1999

Role of human CYP2B6 in S-mephobarbital N-demethylation.

The role of cytochrome P-450s (CYPs) in S-mephobarbital N-demethylation was investigated by using human liver microsomes and cDNA-expressed CYPs. Among the 10 cDNA-expressed CYPs studied (CYP1A1, CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2E1, and CYP3A4), only CYP2B6 could catalyze S-mephobarbital N-demethylation. The apparent K(m) values of human liver microsomes for S-mephobarbital N-demethylation were close to that of cDNA-expressed CYP2B6 (about 250 microM). The N-demethylase activity of S-mephobarbital in 10 human liver microsomes was strongly correlated with immunodetectable CYP2B6 levels (r = 0.920, p<.001). Orphenadrine (300 microM), a CYP2B6 inhibitor, inhibited the N-demethylase activity of S-mephobarbital in human liver microsomes to 29% of control activity. Therefore, it appears that CYP2B6 mainly catalyzes S-mephobarbital N-demethylation in human liver microsomes.

Anticonvulsants↗
PubMed1999

[Genetic and epigenetic alterations associated with cancer metastasis].

It is now well accepted that cancer is attributed to the accumulation of genetic alterations in the cells. Thus, to understand the molecular mechanisms of cancer metastasis, it is indispensable to identify the genes whose alterations accumulate during cancer progression as well as the genes whose expression is responsible for invasion and metastasis. Two different molecular approaches have been taken to identify such genes. One is the identification of genes whose alterations accumulate during cancer progression. The other is the identification of genes whose expression is responsible for the acquisition of metastatic potential in cancer cells. Molecular analyses of cancer cells in various stages of progression have revealed that alterations of tumor suppressor genes and oncogenes accumulate during cancer progression and correlate with the clinical aggressiveness of cancer cells. Comparative analyses of gene expression profiles between high-metastatic and non-metastatic cells have also revealed that various genes are differentially expressed in association with the metastatic potential of cancer cells. In the near future, the information obtained from these studies can be applied to the diagnosis, treatment and prevention of metastases.

Base Pair Mismatch↗
PubMed1998

The chemokine growth-regulated oncogene-alpha promotes spinal cord oligodendrocyte precursor proliferation.

Chemokines, (chemotactic cytokines) are a family of regulatory molecules involved in modulating inflammatory responses. Here we demonstrate that the chemokine growth-regulated oncogene-alpha (GRO-alpha) is a potent promoter of oligodendrocyte precursor proliferation. The proliferative response of immature spinal cord oligodendrocyte precursors to their major mitogen, platelet derived growth factor (PDGF), is dramatically enhanced by GRO-alpha present in spinal cord conditioned medium. One source of GRO-alpha is a subset of spinal cord astrocytes. Cultures of astrocytes contain GRO-alpha mRNA and protein and secrete biologically active concentrations of GRO-alpha. In postnatal spinal cord white matter the location of GRO-alpha-immunoreactive cells is developmentally regulated: GRO-alpha+ cells first appear in ventral and later in dorsal spinal cord white matter. These results suggest that localized proliferation of oligodendrocytes is mediated by synergy between PDGF and GRO-alpha.

Animals↗
PubMed1998

Enzymatic synthesis of omega-amino-ceramide: preparation of a sensitive fluorescent substrate for ceramidase.

Sphingolipid ceramide N-deacylase catalyzes the reversible reactions in which the N-acyl linkage of ceramides of various sphingolipids is hydrolyzed or synthesized under different conditions. We report here a new method for preparation of ceramide containing omega-amino-fatty acid by using the condensation reaction of the enzyme. omega-Aminododecanoic acids were efficiently condensed by the enzyme to sphingosine in 25 mM glycine-NaOH buffer, pH 10, containing 0.3% Triton X-100 when the amino residue at the omega position of the fatty acid was blocked with trifluoroacetate. The reaction product was purified sequentially from the reaction mixture on a C18 reversed-phase column and Sep-Pak Plus Silica and Sep-Pak QMA cartridges with an overall yield of 80% and determined to be omega-aminododecanoylsphingosine by thin-layer chromatography and fast atom bombardment-mass spectrometry analyses after removing the block of trifluoroacetate by alkaline treatment. The enzyme can also be applied successfully to the synthesis of various glycosphingolipids and sphingomyelin containing omega-aminododecanoic acids. The 7-nitrobenz-2-oxa-1,3-diazole (NBD)-labeled N-dodecanoylsphingosine was easily prepared from the omega-amino-ceramide by coupling with NBD-fluoride. This fluorescent ceramide was found to be hydrolyzed by ceramidase of B16 melanoma cells much faster than NBD-labeled N-hexanoylsphingosine in vitro as well as in vivo, indicating that the former is an excellent substrate for the assay of ceramidase.

Amidohydrolases↗
PubMed1998

Selective chemokine mRNA accumulation in the rat spinal cord after contusion injury.

Following traumatic injury to the spinal cord, hematogenous inflammatory cells including neutrophils, monocytes, and lymphocytes infiltrate the lesion in a distinct temporal sequence. To examine potential mechanisms for their recruitment, we measured chemokine mRNAs in the contused rat spinal cord, using specific and sensitive reverse transcriptase polymerase chain reaction (RT-PCR) dot-blot hybridization assays. The neutrophil chemoattractant GRO-alpha was 30-fold higher than control values at 6 hr postinjury and decayed rapidly thereafter. LIX, a highly related alpha-chemokine, also was elevated early postinjury. Monocyte chemoattractant peptide (MCP)-1 and MCP-5 mRNAs, potent chemoattractants for monocytes, were significantly elevated at the lesion epicenter at 12 and 24 hr postinjury and declined thereafter. Interferon-gamma-inducible protein, 10 kDa (IP-10), chemoattractant towards activated T-lymphocytes, was significantly elevated at 6 and 12 hr postinjury. The dendritic cell chemoattractant MIP-3alpha also was increased, perhaps contributing to the development of T-cell autoreactivity to neural components after spinal cord injury (SCI) in rats. Other beta-chemokines, including MIP-1alpha and RANTES (regulated on expression normal T-cell expressed and secreted), were minimally affected by SCI. Expression of chemokines, therefore, directly precedes the influx of target neutrophils, monocytes, and T-cells into the spinal cord postinjury, as noted previously. Thus, selective chemokine expression may be integral to inflammatory processes within the injured spinal cord as a mechanism of recruitment for circulating leukocytes.

Animals↗