Search PubMed⌕ Search

Biomedical subjects

T Murakami

Publications and source records attributed to T Murakami.

At least 793 records · Page 44Linked to original sources
PubMed1995

Tax protein of HTLV-1 destabilizes the complexes of NF-kappa B and I kappa B-alpha and induces nuclear translocation of NF-kappa B for transcriptional activation.

Tax protein of HTLV-1 stimulates transcription of specific cellular genes through the NF-kappa B binding site. We previously showed that Tax binds to the ankyrin motifs of I kappa B-gamma, and dissociates the I kappa B-gamma/NF-kappa B complexes, resulting in nuclear translocation of NF-kappa B proteins. We herein report the effects of Tax on I kappa B-alpha, another member of I kappa B family proteins expressed in human T cells. Tax binds to I kappa B-alpha and partially dissociates the NF-kappa B/I kappa B-alpha complex in vitro. In Tax-expressing cells, Tax/I kappa B-alpha complex was detected only at low level, but NF-kappa B/I kappa B-alpha complex was mostly dissociated and NF-kappa B was translocated into the nucleus. Furthermore, Tax induced reduction of I kappa B-alpha protein. I kappa B-alpha protein was stabilized by NF-kappa B protein through forming NF-kappa B/I kappa B-alpha complex, but Tax expression cancelled this stabilization effect on I kappa B-alpha. These findings suggest that Tax induces dissociation of and/or inhibits the formation of NF-kappa B/I kappa B-alpha complexes, resulting in release of NF-kappa B and destabilization of I kappa B-alpha. Consistently, transcription of NF-kappa B directed gene was activated. These Tax effects counteract the negative feedback control of NF-kappa B by I kappa B-alpha and contribute to constitutive activation of NF-kappa B in Tax-transfected and HTLV-1-infected cells.

Biological Transport↗
PubMed1995

Regulation by physical training of enzyme activity and gene expression of branched-chain 2-oxo acid dehydrogenase complex in rat skeletal muscle.

We examined the effects of short-term (5 weeks) and long-term (12 weeks) physical training on actual and total activities, protein content and mRNA abundance of branched-chain 2-oxo acid dehydrogenase complex in rat skeletal muscle. The actual and total activities were significantly increased approximately 60% and approximately 40%, respectively, by long-term training. No effects of short-term training on activities were observed. The increase in the total activity corresponded to increased protein content of the E1 alpha and E2 components of the complex. On the other hand, mRNA abundance for E1 alpha and E2 were not affected by the training, but that for E1 beta was slightly, but significantly increased by both short-term and long-term trainings. These divergent alterations of the message levels for the subunits of the complex suggest that posttranslational regulatory mechanisms determine the amount of the complex in skeletal muscle. Since the complex is located in the mitochondrial matrix space, mitochondrial biogenesis in response to the training was examined by determining the content of mitochondrial DNA in the muscle. The mitochondrial DNA was proportionally increased with the total activity as well as the protein content of the complex, suggesting that expression of branched-chain 2-oxo acid dehydrogenase complex in skeletal muscle in response to physical training is associated with mitochondrial biogenesis.

3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide)↗
PubMed1995

HTLV-1 Tax enhances NF-kappa B2 expression and binds to the products p52 and p100, but does not suppress the inhibitory function of p100.

Tax protein of HTLV-1 triggers transcriptional activation through enhancers, NF-kappa B binding site, 21-bp enhancer, and serum response element. Previously, we demonstrated binding of Tax to transcription factors NF-kappa B1 p105 and p50. Here, we report that Tax enhances expression of NF-kappa B2 at the mRNA level and proteins; the effect was more apparent on the p52 expression than on its precursor p100, suggesting post-translational regulation. Consistent with these observations, HTLV-1-infected T-cell lines expressed higher levels of p52. Tax binds to the protein products p52 and p100 which inhibits NF-kappa B proteins forming cytoplasmic complexes; the binding to p100 was preferential over NF-kappa B1 p105. However, Tax did not induce efficient dissociation of the cytoplasmic complexes p100/c-Rel or p100/p65, and thus did not induce nuclear translocation of c-Rel or p65. This was in sharp contrast to the previous observation that Tax dissociated the p105/c-Rel and I kappa B-gamma/p65 complexes. These results indicate that HTLV-1 Tax interacts with NF-kappa B2 p100 and p52 and upregulate the NF-kappa B function, but their contribution to Tax-mediated transcriptional regulation differs from those of NF-kappa B1.

Base Sequence↗
PubMed1995

Cytosolic localization of beta 3-subunit of heterotrimeric GTP binding protein in rat hearts.

The expression of three different subtypes of GTP binding protein beta-subunits (beta 1, beta 2 and beta 3) was examined in rat hearts at both mRNA and protein levels. Among three subtypes, beta 3 mRNA was more abundant in ventricles while beta 1 and beta 2 mRNAs were expressed ubiquitously among ventricles, atria and aortas. The immunodetectable beta 1- and beta 3-proteins were predominantly found in the cytosolic fraction of rat ventricles. In this study, we demonstrate ventricle-specific expression of beta 3-subunit and localization of G protein beta 3-subunit in the cytosol of rat hearts. This unusual cytosolic localization of G protein beta 3-subunit might indicate subtype-specific function of G protein beta (gamma)-subunits in rat hearts.

Animals↗
PubMed1995

Comparison of the hypervariable region of hepatitis C virus genomes in plasma and liver.

Nucleotide sequences of the hypervariable region of hepatitis C virus genomes obtained from plasma change rapidly during the course of infection and are believed to play a part in immunological escape and consequently in the development of persistent infection. It is not known, however, whether these changes also occur in the liver. To clarify this aspect, RNA was extracted from the plasma and liver tissue of eight patients with chronic hepatitis C. After cDNA synthesis, DNA fragments that included the hypervariable region were amplified by the polymerase chain reaction. Consensus nucleotide sequences were determined directly from the polymerase chain reaction products by the dideoxy chain termination method. The diversity of the hypervariable region was analyzed further by the polymerase chain reaction-single strand conformation polymorphism analysis. Consensus nucleotide sequences of the hypervariable region were identical between the plasma and the liver in each patient. The polymerase chain reaction-single strand conformation polymorphism analysis showed multiple DNA bands that represented different hypervariable region sequences. Comparison of the single strand conformation polymorphism patterns revealed that the number, the mobility, and the density of bands were the same between the plasma and the liver. It is concluded that the population and the diversity of hepatitis C virus quasispecies as detected by the hypervariable region sequence are the same between the plasma and the liver despite rapid mutations, indicating that rapid changes in the population of hepatitis C virus quasispecies also occur in the liver.

Amino Acid Sequence↗
PubMed1995

Venous hemangioma of the mesoappendix: report of a case and a brief review of the Japanese literature.

We present herein the rare case of a 48-year-old man in whom an abdominal mass, revealed by celiotomy to be a solid tumor of the mesoappendix, was histologically diagnosed as having a venous hemangioma. To our knowledge, only 18 cases of mesenteric hemangioma have been reported in Japan, including the present case. However, establishing a correct diagnosis preoperatively is extremely difficult despite advanced imaging techniques. In fact, a mesenteric mass was diagnosed preoperatively in only 3 of these 18 cases. Complete excision with or without bowel resection was performed in 16 cases. Interestingly, the histological diagnosis of all the previous cases was cavernous hemangioma, confirming that this report documents the first case of venous hemangioma of the mesentery in the Japanese literature.

Appendiceal Neoplasms↗
PubMed1995

Effect of hyperthermia on cyclin B expression in a human glioblastoma cell line.

Effects of hyperthermia on the cell kinetics of glioblastoma cells were investigated using flow cytometry. Pulse-labeling with 5-bromodeoxyuridine (BUdR) and chasing of the labeled cells revealed temporary accumulation of the labeled cells in G2M phase and a reduction of DNA synthesis. The level of cyclin B rises rapidly in G2 phase and falls at the end of mitosis in normal cycling cells. Cyclin B binds to p34cdc2, resulting in histone kinase activity which is necessary for the initiation of mitosis. The amount of p34cdc2 remains constant throughout the cell cycle. The level of cyclin B was measured using an anti-cyclin B antibody and flow cytometry in order to investigate the cause of the G2 accumulation induced by hyperthermia. A low level of cyclin B, in comparison with that of normal cycling cells, persisted for more than 3 h after hyperthermia. These results indicate that the temporary accumulation of cells in G2M phase after hyperthermia may be caused, at least in part, by an insufficient level of cyclin B.

Antibodies, Monoclonal↗
PubMed1995

Laser vaporization of the ovarian surface in polycystic ovary disease results in reduced ovarian hyperstimulation and improved pregnancy rates.

OBJECTIVE: Our purpose was to examine the efficacy of laser vaporization of the ovarian surface in polycystic ovary disease to reduce repeated ovarian hyperstimulation syndrome and thereby improve pregnancy outcome. STUDY DESIGN: Twenty-six infertile patients with polycystic ovary disease who previously had ovarian hyperstimulation syndrome after stimulation with human menopausal gonadotropin and who failed to conceive were studied. All patients were treated by potassium titanyl phosphate and neodymium-yttrium-aluminum-garnet laser and evaluated. Patients not ovulating spontaneously after vaporization were treated with either clomiphene citrate or human menopausal gonadotropin. RESULTS: After vaporization spontaneous ovulation was confirmed in six patients. For ovulation induction three patients received clomiphene citrate and 17 received human menopausal gonadotropin. Of the patients treated with human menopausal gonadotropin, mild ovarian hyperstimulation syndrome was found in three patients, and the incidence of ovarian hyperstimulation syndrome decreased significantly. Pregnancy was confirmed in 19 of 26 patients. CONCLUSION: Laser vaporization is promising for the prevention of ovarian hyperstimulation syndrome and improving pregnancy outcome in patients with polycystic ovary disease who have previously had ovarian hyperstimulation syndrome.

Adult↗
PubMed1995

Double-minute chromosomes appearing in a patient with myelodysplastic syndrome with disease evolution.

We present the first case of a myelodysplastic syndrome (MDS) demonstrating an association between the appearance of double-minute chromosomes (dmin) and disease progression. This 59-year-old Japanese woman showed a deletion of the long arm of chromosome 5 [del(5)(q21q34)] and monosomy 9, when she was diagnosed as having refractory anemia with an excess of blasts (RAEB). Subsequential cytogenetic analyses demonstrated that the neoplastic cells in the peripheral blood had six copies of dmin, when the disease progressed into RAEB in transformation (RAEBt). This cytogenetic change was consistently observed when the patient developed the leukemia phase. The findings in this case suggest that the appearance of dmin may be linked to progression of the disease.

Chromosome Aberrations↗
PubMed1995

Naloxone suppresses the rising phase of fever induced by interferon-alpha.

Interferon-alpha (IFN-alpha, 2.0 x 10(4) units) was bilaterally microinjected into the medial preoptic area and anterior hypothalamus in conscious rats treated 10 min prior with an opioid receptor antagonist, naloxone (NLX, 2 mg/kg, IM) or a prostaglandin synthetase inhibitor, acetaminophen (ACAP, 25 mg/kg, IM). The IFN-alpha-induced rise of rectal temperature (Tre) was suppressed from 20 to 60 min in NLX pretreated rats and from 30 to 180 min in ACAP pretreated rats. The rate of rise in Tre during the initial 20 min observed in NLX pretreated rats was significantly smaller than that in ACAP or saline pretreated rats. ACAP suppressed the fever when it was given 50 or 100 min after injection of IFN-alpha. In contrast, NLX did not affect the fever when given 25 or 50 min after IFN-alpha. The results suggest that an opioid that its involvement may last only in the early phase of the fever, but not after the plateau has been reached.

Analysis of Variance↗
PubMed1995

Left ventricular function in chronic mitral regurgitation: preoperative and postoperative comparison.

OBJECTIVES: The present study was designed to evaluate the effects of surgical procedure on left ventricular systolic and diastolic function in patients with mitral regurgitation. BACKGROUND: Left ventricular systolic function has been shown to decline after operation in patients with chronic mitral regurgitation. METHODS: Using simultaneous cineangiography and left ventricular micromanometry, we evaluated left ventricular systolic and diastolic function in 14 patients with chronic mitral regurgitation both preoperatively and at an average of 22 months after operation. Eight patients underwent mitral valve reconstruction, and six had a valve replacement with interruption of the chordae tendineae. We compared these patients with 10 control subjects. RESULTS: Preoperatively, patients with mitral regurgitation demonstrated normal global and regional left ventricular systolic function. Peak rate of diastolic filling was increased (p < 0.01), and passive chamber stiffness was decreased, compared with that in control subjects (p < 0.01), and there was normal myocardial stiffness. Postoperatively, systolic and diastolic function returned to normal in patients undergoing mitral valve reconstruction. In contrast, global systolic function was depressed in patients after valve replacement (p < 0.05), with regional dysfunction in the area of papillary muscle attachment (p < 0.01). Diastolic function was depressed in this group, with a prolonged time constant of pressure decay (p < 0.01) and a depressed rate of early diastolic filling and strain rate (p < 0.05). Passive elastic stiffness was within the normal range in all postoperative patients. CONCLUSIONS: The type of operation performed to correct chronic mitral regurgitation has an important effect on postoperative left ventricular function. Systolic and diastolic function are preserved after mitral valve reconstruction. Mitral valve replacement with chordal interruption is associated with global and regional systolic dysfunction and early diastolic filling and relaxation abnormalities.

Adult↗
PubMed1995

Measurement of anti-factor VIII IgG, IgG4 and IgM alloantibodies in previously untreated hemophilia A patients treated with recombinant factor VIII. Kogenate Japanese Clinical Study Group.

Using enzyme-linked immunosorbent assay (ELISA), we measured anti-factor VIII immunoglobulin G (IgG), IgG4 and IgM in serum samples obtained from hemophilia A patients treated with a recombinant factor VIII (rFVIII) preparation (Kogenate). Twelve pre- and post-treatment serum samples from 3 previously untreated patients who developed an inhibitor (alloantibody) were evaluated. Both rFVIII and plasma-derived factor VIII (pdFVIII) were used as antigen. Serum samples were diluted 37.5-fold. For the measurement of IgM antibody, protein A Sephadex suspension was added to the patients' serum samples and the supernatant was assayed. Anti-human IgG, IgG4, and IgM monoclonal antibodies labelled with peroxidase were added and absorbance at 450nm was determined. The reactivity of the IgG antibody with rFVIII and pdFVIII was extremely low. Samples containing the IgG4 inhibitor with a neutralizing activity of approximately 7.5 Bethesda units (BU)/ml resulted in absorbance values of 0.451-0.551, thus demonstrating a considerably high degree of sensitivity. The correlation between the neutralizing activity and reactions of the IgG4 antibody with rFVIII and pdFVIII antigens was high, with correlation coefficients of 0.912 and 0.966, respectively. Furthermore, the correlation coefficient between the measured absorbance values for the antibody reacted with pdFVIII and rFVIII was 0.961. No correlation was found between the reactivity of IgM to rFVIII and pdFVIII.

Adult↗
PubMed1995

Cytochrome P450(11 beta): structure-function relationship of the enzyme and its involvement in blood pressure regulation.

Cytochrome P450(11 beta) is deeply involved in the final steps of biosynthesis of mineralocorticoids. This paper deals with following issues about this enzyme. (1) The structure and function of the enzymes of various animal species are discussed. By making alignment of amino acid sequences of the enzymes, we identified peptide domains essential for the enzyme actions such as a putative steroid binding domain and a heme binding region. Estimates of molecular similarity among the P450(11 beta) family enzymes suggested that the enzymes having both 11 beta-hydroxylation activity and aldosterone (ALDO) synthetic activity of certain animals such as frog, cattle and pig are more similar to the ALDO synthases of the other animals, such as rat, mouse and human, than the 11 beta-hydroxylases of these animals. (2) The molecular nature of the P450(11 beta) family enzymes of genetically hypertensive rats as well as adrenal regeneration hypertension (ARH) rats is examined. (i) Mutation was found in the P450(11 beta) gene of Dahl's salt-resistant normotensive rat. Steroidogenic activity expressed by the mutated gene accounted well for abnormal plasma levels of steroid hormones in this rat. (ii) 11 beta-, 18- and 19-Hydroxylation activities of adrenal mitochondrial prepared from spontaneously hypertensive rat (SHR), Wistar-Kyoto rat (WKY), and stroke-prone (SP)-SHR were not significantly different from each other. Levels of mRNA of ALDO synthase in adrenal glands of 50-week-old SHR was significantly lower than those of 10-week-old SHR, WKY and SHR-SP. (iii) No significant difference in 19-hydroxylation activity was found between adrenal mitochondria prepared from ARH rat and those from control rat. The level of message of ALDO synthase was lower in adrenal glands of ARH rat.

Aldosterone↗
PubMed1995

Balloon angioplasty before Wheat's operation in a patient with Turner's syndrome.

The case of a 19-year-old woman with Turner's syndrome, dissecting aneurysm of the ascending aorta, coarctation of the aorta and bicuspid aortic valve stenosis is presented. Balloon angioplasty was performed before surgery to relieve the pressure gradient caused by coarctation of the aorta. Successful surgical treatment was carried out using Wheat's method. Four-year follow-up has revealed no signs of complications such as restenosis or aneurysm formation.

Adult↗
PubMed1995

Soft drugs. 18. Oral and rectal delivery of loteprednol etabonate, a novel soft corticosteroid, in rats--for safer treatment of gastrointestinal inflammation.

PURPOSE: As a safe anti-inflammatory corticosteroid, the utility of loteprednol etabonate (LE) for the treatment of gastrointestinal inflammation, via oral and rectal administration, was investigated in rats. METHODS: In vivo, LE solution and suspension were orally administered (20 mg/kg), and various LE preparations (solution, suspension & suppository) were applied in rectal loops (0.2 mg per loop). In vitro, various GI tissues were used to study the stability and partition of LE. RESULTS: After oral administration of LE solution, LE reached the upper GI tract effectively, but not the colon, due to absorption and/or decomposition. In suspension, LE reached most of the GI tract (except rectum) in 8 hr and showed little absorption. After rectal applications, LE remained intact in the rectal loop for more than five hours with a slow rate of disappearance, however, LE distributed in the rectal membrane to some extent. The concentrations of LE and its inactive metabolites in plasma after both oral and rectal administrations were lower than the detection limit (0.1 microgram/ml) at anytime during the experiments. In vitro, LE in solution was stable in stomach, but not in cecum, due to the hydrolysis by the cecal resident micro flora. In solution, LE distributed into the mucosal membranes efficiently (about 2.5-4.0 micrograms/g tissue). CONCLUSIONS: The results suggest that LE can be orally or rectally delivered in the GI tract for the topical treatment of the inflammatory bowel disease.

Administration, Oral↗
PubMed1995

Soft drugs. 19. Pharmacokinetics, metabolism and excretion of a novel soft corticosteroid, loteprednol etabonate, in rats.

PURPOSE: Pharmacokinetics, metabolism and excretion of loteprednol etabonate (LE) were investigated in rats. METHODS: The pharmacokinetic studies were performed by iv injections of LE (1-20 mg/kg). In the metabolism and excretion studies, 0.5-10 mg/kg of LE were iv administered, bile and urine samples were collected for 6 hr. RESULTS: The pharmacokinetic of LE showed a rapid, dose-dependent elimination with a total blood clearance (CLtotal) of higher than 60 ml/min/kg. The metabolism and excretion of LE also showed a marked dose-dependency. At 6 hr after iv of LE (0.5-10 mg/kg), the total recoveries (LE and the metabolites, AE & A, in bile and urine) were 99.35-26.72%. However, only about 2% of LE was excreted from the body through the urine. There were 0.93-2.12% and 0.66-0.26% of AE, and 75.67-19.69% and 20.74-2.77% of A excreted in the bile and urine, respectively. The excretion of A was dose dependent, and significantly higher at the lower dose. Using the (% of total excretion) vs. (log dose) plots, it could be predicted that almost all of the administered LE will be metabolized, and excreted as A when the systemic dose is lower than 0.25 mg/kg. CONCLUSIONS: The results indicate that LE absorbed systemically, after topical administration, can be rapidly transformed to the inactive metabolites, and eliminated from the body mainly through the bile and urine.

Androstadienes↗
PubMed1995

Spinal cord injury in a child: a long term follow-up study. Case report.

The main features of spinal cord injuries in children are known to be that (1) plain radiographs do not show the bony injury; (2) many of the injuries are complete spinal cord injuries; (3) many involve the upper thoracic spine; and (4) the duration of spinal shock is short. Complications such as pressure sores occur just as easily in children as in adults and the injuries are intractable. Typical complications in children with spinal cord injuries are spinal deformity and hip dislocation. We discuss a patient with a C7 spinal cord injury caused by a fall when the patient was 3 years old, and the physical complications occurring during the 15 years following the injury.

Adolescent↗