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Biomedical subjects

M Nagai

Publications and source records attributed to M Nagai.

At least 163 records · Page 9Linked to original sources
PubMed1998

Methylation of the p16INK4A gene in multiple myeloma.

The p16INK4A (p16) binds to both cyclin D-CDK4 and cyclin D-CDK6 and inhibits the progression of the cell cycle from G1 to S phase. Loss of expression of this protein can occur by several mechanisms including structural alterations. Recent studies have suggested that the loss of expression of p16 can occur by hypermethylation of the gene. The methylation status of the p16 gene in multiple myeloma was examined in three myeloma cell lines (U266, RPMI8226 and IM9) and 16 primary myeloma samples using methylation-specific polymerase chain reaction (MSP). The U266 and RPMI8226 cell lines contained a completely methylated p16 gene and the IM9 line had a partially methylated p16 gene. Identical results were obtained by another polymerase chain reaction (PCR)-based methylation assay system as well as Southern blotting after using a methylation-sensitive restriction enzyme. The U266 cell line expressed no p16, and the IM9 had weak expression as determined by reverse transcript (RT-)PCR. The U266 cells began to express, and IM9 increased the accumulation of, the p16 RNA after treatment with the demethylating agent 5'-aza-2-deoxycytidine (10(-6)-10(-5) M). This suggested that the levels of methylation of the p16 gene detected by the MSP technique correlated with the regulation of transcription of this gene. Examination of the primary myeloma samples showed that eight of 16 (50%) contained a methylated p16 gene. We have previously found that alterations of the p16 gene, such as deletions and point mutations, are rare in primary multiple myeloma; none of the 16 samples included in this study had p16 gene alterations. Our results suggest that methylation of the p16 gene may contribute to the development and/or progression of multiple myeloma.

Aged↗
PubMed1998

A novel mature B-cell line (DOBIL-6) producing both parathyroid hormone-related protein and interleukin-6 from a myeloma patient presenting with hypercalcaemia.

A novel human EBV-negative B-cell line, designated DOBIL-6, was established from a patient with non-secretary myeloma. The DOBIL-6 cell has cytoplasmic gamma protein and expresses CD19, 20, 38, 45RO, VLA-4 and PCA-1 antigens, but lacks CD10, 45RA and VLA5 antigens. Chromosome analysis showed that DOBIL-6 cells had many complex structural abnormalities, including t(11;4) (q13;q32), which were consistent with that of the fresh tumour cells. Interestingly, abundant interleukin-6 (IL-6) and parathyroid hormone-related protein (PTHrP) accumulated in the culture supernatant of DOBIL-6 cells. Hypercalcaemia and splenomegaly associated with plasma cell proliferations which resulted in the expansion of the light zones in the follicles were observed in DOBIL-6 transplanted nude mice. RT-PCR analysis detected mRNA for PTHrP, and IL-6 as well as its receptor (GP80) in DOBIL-6 cells. Treatment of the DOBIL-6 cells with neutralizing anti-IL-6 antibody inhibited their growth in a dose-dependent manner, whereas the addition of exogenous IL-6 stimulated it in serum-depleted conditions. These findings suggest that both IL-6 and PTHrP are produced in DOBIL-6 cells, and that IL-6 promotes its growth by an autocrine mechanism. Since IL-6 is known to stimulate not only the growth of B-cell neoplasms but also osteoclastic bone resorption by cooperating with PTHrP, this simultaneous production of IL-6 and PTHrP might be synergistically linked and play a role in the development of hypercalcaemia of the patient. The DOBIL-6 cell is a useful tool to clarify the mechanism of hypercalcaemia associated with mature B-cell neoplasms.

Aged↗
PubMed1998

Cytokine-enhanced mixed lymphocyte reaction (MLR) in cord blood.

Although in cord blood (CB) transplantation graft-versus-host disease (GVHD) is reported to be less severe, GVHD may occur even in patients with HLA-identical sibling donors. This result shows that HLA typing can not entirely predict GVHD. The standard MLR with CB cells was either normal or slightly reduced compared with adult peripheral blood (PB) cells. We used two manipulations to increase the responses of CB cells to allo-antigens. The first was to treat the stimulator cells with cytokines, and the second to amplify weak proliferative responses by adding exogenous cytokines to MLR cultures (modified MLR). The stimulator cells were treated with both interferon-gamma (IFN-gamma) and IL-4. The responder cells were treated with both IL-2 and tumour necrosis factor-alpha (TNF-alpha). It is still to be determined whether or not this cytokine-enhanced MLR could be a possible predictor of GVHD. However, using these cytokines, 90% of CB could recognize allo-antigens, even if the standard MLR was negative.

Adult↗
PubMed1998

Additive effects of bovine serum albumin, dithiothreitol, and glycerol on PCR.

The effects of bovine serum albumin, dithiothreitol, and glycerol on PCR were studied. PCR under standard conditions failed the amplification of an enterohemorrhagic E. coli DNA fragment when the boiled bacterial cell lysate was used as the template. The addition of either one of bovine serum albumin, dithiothreitol, or glycerol in the reaction mixture allowed the specific fragment amplification; and the optimum concentrations were as follows: bovine serum albumin, 1 mg/ml; dithiothreitol, 10 mM; and glycerol, 5%. In addition, when all of the three agents were included at the above concentrations, the PCR yield was further increased. The effect of the three-agent mixture was not the template specific. Furthermore, the mixture enabled long PCR over 20 kb when Taq DNA polymerase with 3'-5' exonuclease activity was used for the amplification. Our simple PCR method allows robust PCR independent of template purity or amplification length.

Animals↗
PubMed1998

A novel domain in the CD30 cytoplasmic tail mediates NFkappaB activation.

About 100 amino acid residues in the C-terminal region are conserved among human, rat and murine CD30, a member of the tumor necrosis factor receptor (TNFR) superfamily, and can be separated into three subdomains with relatively higher conservation (D1, D2 and D3). Activation of NFkappaB by CD30 was shown to be mediated through interaction of TNFR-associated factor (TRAF) 1, 2 and 5 with the D2 and D3 subdomains. However, the function of the other conserved subdomain, D1, remained to be determined. Deletion of the D2 and D3 subdomains abolished interactions with TRAF2 and 5 but it did not affect NFkappaB activation. Reporter gene assays using deletion and mutant constructs of CD30 revealed that the D1 subdomain is sufficient for NFkappaB activation, without interaction with TRAF2 or 5, and that each subdomain alone can activate NFkappaB. Electrophoretic mobility shift assays revealed constitutive and CD30-induced NFkappaB activation in stable transformants of 293 cells expressing CD30 or a deletion mutant lacking D2 and D3 subdomains. Deletion of C-terminal 19 amino acid residues of the D1 subdomain abolished activation of NFkappaB. Substitution of alanine for one of the two threonine residues (amino acid position 524 and 529), one of which is a potential phosphorylation site in the D1 subdomain, also abolished the NFkappaB activation. Overexpression of the TRAF domain of TRAF2 or 5 had a dominant negative effect on the NFkappaB activation mediated by the D1 subdomain, thereby suggesting involvement of TRAF proteins in the signaling. Thus, the C-terminal 100 amino acid region of CD30 is composed of three independent functional subdomains, two of which contain binding sites for TRAF proteins. A novel domain in the cytoplasmic tail mediates NFkappaB activation, without direct interaction of TRAF2 or 5. Our observations suggest involvement of an unknown TRAF protein(s) in the signal transduction pathway of CD30.

Binding Sites↗
PubMed1998

Family environment, hobbies and habits as psychosocial predictors of survival for surgically treated patients with breast cancer.

Many psychosocial factors have been reported to influence the duration of survival of breast cancer patients. We have studied how family members, hobbies and habits of the patients may alter their psychosocial status. Female patients with surgically treated breast cancer diagnosed between 1986 and 1995 at the Tochigi Cancer Center Hospital, who provided information on the above-mentioned factors, were used. Their subsequent physical status was followed up in the outpatients clinic. The Cox regression model was used to evaluate the relationship between the results of the factors examined and the duration of the patients' survival, adjusting for the patients' age, stage of disease at diagnosis and curability, as judged by the physician in charge after the treatment. The following factors were revealed to be significant with regard to the survival of surgically treated breast cancer patients: being a widow (hazard ratio 3.29; 95% confidence interval 1.32-8.20), having a hobby (hazard ratio 0.43; 95% confidence interval 0.23-0.82), number of hobbies (hazard ratio 0.64; 95% confidence interval 0.41-1.00), number of female children (hazard ratio 0.64; 95% confidence interval 0.42-0.98), smoker (hazard ratio 2.08; 95% confidence interval 1.02-4.26) and alcohol consumption (hazard ratio 0.10; 95% confidence interval 0.01-0.72). These results suggest that psychosocial factors, including the family environment, where patients receive emotional support from their spouse and children, hobbies and the patients' habits, may influence the duration of survival in surgically treated breast cancer patients.

Adult↗
PubMed1998

Heterogeneity of ictal SPECT findings in nine cases of West syndrome.

We evaluated the ictal and interictal single photon emission computed tomography (SPECT) of 9 patients with West syndrome (WS). In this group, we noted two clear patterns of cortical hyperperfusion and subcortical hyperperfusion in the ictal SPECT. Both patterns were different from the previously documented ictal patterns for complex partial seizures (CPS) or secondarily generalized seizures. Our results suggest that the tonic spasms of WS do not always have a single neurophysiological basis; e.g., patients with hemihypsarrhythmia and focal hypsarrhythmia did not show ictal hyperperfusion of the lesion with hypsarrhythmia. These findings indicate that the origin of hypsarrhythmia as an EEG feature and the origin of tonic spasms may be different in such patients. In particular, hypsarrhythmia appears to originate from cortical lesions, whereas the subcortical structures may be primarily responsible for the tonic spasms. Our report is the first published study of ictal SPECT in patients with WS.

Adolescent↗
PubMed1998

Vasoactive effects of cimicifugic acids C and D, and fukinolic acid in cimicifuga rhizome.

Vasoactive effects of cimicifugic acids A-E, fukinolic acid and fukiic acid isolated from Cimicifuga plants were investigated using rat aortic strips. Cimicifugic acid D and fukinolic acid at 3x10(-4) M caused a sustained, slowly developing relaxation of aortic strips precontracted with norepinephrine (NE) in preparations with or without endothelium. Cimicifugic acid C inversely caused a weak contraction. Cimicifugic acids A, B and E and fukiic acid showed no vasoactivity at 3x10(-4) M. Cimicifugic acids A-E and fukinolic acid are esters between cinnamic acids and the hydroxyl group of benzyltartaric acids. For the manifestation of vasoactivity in the rat aorta, it is concluded that in the cinnamic acid moiety, a caffeoyl group might be necessary for the relaxation activity, and the p-coumaroyl group causes contraction. Concentration response curves for the Ca2+-induced contracture of depolarized aortic strips with isotonic high K+ were not affected by cimicifugic acid D or fukinolic acid. The Ca2+-induced contraction of aortic strips, preincubated with 10(-6) M NE in the presence of 10(-6) M nicardipine and 0.01 mM EGTA in Ca2+-free solution, were inhibited by cimicifugic acid D and fukinolic acid. These results indicated that the inhibition by cimicifugic acid D and fukinolic acid of the NE-induced contraction of rat aorta are attributable to the suppression of Ca2+ influx from the extracellular space enhanced by NE.

Animals↗
PubMed1998

[Characteristics of medical institutions visited by patients with intractable diseases--analyses of patients receiving financial aid for treatment].

The Research Committee of Epidemiology of Intractable Diseases (Ministry of Health and Welfare, Japan) conducted a nationwide survey of 34 intractable diseases. Each of 47 prefectural governments reported information on all patients with the diseases who received financial aid for the disease from April 1992 to March 1993. Information collected on each patient included the identification number, sex, age, the code of the municipality where the patient lived, and the medical institution and department where the patient was being treated. Out of 247, 726 patients whose information was reported by prefectural governments, we analysed data of 208,945 patients whose medical institutions were reported. The results can be summarized as follows: 1) Aged patients and children who were less than ten years old tended to visit medical institutions located in their neighborhoods and be treated in small hospitals or clinics. 2) The proportion of patients who visited hospitals with 200 beds or more was 77 percent. 3) Patients with the diseases resulting in physical disabilities such as SMON and malignant rheumatoid arthritis tended to visit clinics. Patients with skin diseases as pemphigus, epidermolysis bullosa and pustular psoriasis tended to be treated in university hospitals. 4) Many patients living in prefectures near large cities such as Tokyo and Ishikawa visited medical institutions in the large cities. 5) The proportion of patients who visited university hospitals decreased during the eight years from 1984 to 1992. However, a quarter of these patients visited university hospitals.

Adolescent↗
PubMed1998

Timing of completion of the first meiotic division in bovine oocytes after maintenance of meiotic arrest with cycloheximide and their subsequent development.

This study examined the timing of completion of meiosis I of bovine oocytes in which meiotic resumption had been inhibited by cycloheximide (CHX), and also determined the optimum interval of maturation in culture for subsequent fertilization and development. Most oocytes treated with CHX reached metaphase II at 16 hr in the maturation culture, while control oocytes did at 20 hr. CHX-treated oocytes cultured for 16 hr were normally fertilized but failed to develop into blastocysts. Maturation in culture for 20 hr resulted in comparable development for control oocytes. The results indicate that nuclear maturation of CHX-treated oocytes was completed 4 hr faster than for control oocytes, however the same interval of maturation as that of control oocytes is necessary for subsequent development to blastocysts.

Animals↗
PubMed1998

Expression of truncated pro-opiomelanocortin gene transcript in human leukemia cell lines.

Although previous studies have suggested that human peripheral blood mononuclear cells (PBMCs) may express pro-opiomelanocortin (POMC) mRNA and synthesize its related peptides, the patho-physiological role of POMC expressed in peripheral cells is not known. In this study, we investigated the POMC gene expression in various types of human leukemia cell lines by Northern blot analysis and the reverse transcribed-polymerase chain reaction (RT-PCR) method. The POMC mRNA was not detected by Northern blot analysis in all cell lines tested except the Jurkat cell line which is derived from T-lymphoblastic leukemia. The POMC mRNA expressed in the Jurkat cells was smaller than that in the human anterior pituitary gland. The RT-PCR method revealed that a truncated-POMC transcript could be detected not only in lymphoblastic leukemia cells but also in erythroid and myeloid cells. Interestingly, two cell lines of monocytic leukemia, J-111 and U937, did not express the truncated-POMC mRNA. Treatment with concanavalin-A stimulated truncated POMC mRNA expression and ACTH-like immunoreactivity in lymphoblastic leukemia cells with T-(Jurkat) and B-(BALL-1) lymphocyte phenotypes. These results confirm that human leukemia cells except for monocytic cells express a truncated-POMC mRNA as well as in the human normal PBMC.

Adrenocorticotropic Hormone↗
PubMed1998

Analysis of HTLV-I proviral load in 202 HAM/TSP patients and 243 asymptomatic HTLV-I carriers: high proviral load strongly predisposes to HAM/TSP.

In order to examine the effect of HTLV-I proviral load on the pathogenesis of HAM/TSP, we measured the HTLV-I proviral load in peripheral blood mononuclear cells (PBMC) from a large number of HAM/TSP patients and asymptomatic HTLV-I carriers. To measure the proviral load, we used an accurate and reproducible quantitative PCR method using a dual-labeled fluorogenic probe (ABI PRISM 7700 Sequence Detection System). The mean +/- standard error of mean (s.e.m.) HTLV-I proviral copy number per 1 x 10(4) PBMC was 798 +/- 51 (median 544) in 202 HAM/TSP patients; 120 +/- 17 (median 34) in 200 non HAM-related (general) asymptomatic HTLV-I carriers (RC); and 496 +/- 82 (median 321) in 43 asymptomatic HTLV-I carriers genetically related to HAM/TSP patients (FA). The prevalence of HAM/TSP rises exponentially with log (proviral load) once the proviral load exceeds 1% PBMC. The HTLV-I proviral load of female patients with HAM/TSP was significantly higher than that of male patients, however there was no significant difference in proviral load between sexes in RC. There was a significant correlation between the proviral load and the concentration of neopterin in CSF of HAM/TSP patients. These results indicate that the HTLV-I proviral load in PBMC may be related to the inflammatory process in the spinal cord lesion. The increased proviral load in FA suggests the existence of genetic factors contributing to the replication of HTLV-I in vivo.

Adult↗
PubMed1998

[Assessment method for supporting programs for social activities of the elderly by city, town and village governments in Japan].

OBJECTIVES: The authors developed a questionnaire to assess the activities of supporting programs for social activities for the elderly conducted by city, town and village governments, based on the number of such programs. This study aims to examine the validity of the questionnaire. METHODS: We conducted a study of 145 cities, towns and villages from two prefectures in Japan using the questionnaire. The questionnaire asks government officers whether they had each of 32 programs, and the number of programs in total, as well as each of four domains of social activities (i.e., employment, social participation/volunteering, education/training, individual activities) were calculated. They were also asked to classify each of the programs into one of four domains of social activity to which the programs were most related; they were asked to rate how active the programs were for each domain in their community. To examine the validity of the questionnaire, the following indicators were assessed: (1) proportion of reported programs which were not covered by the questionnaire; (2) concordance of classification of programs into four domains of social activity with those judged by government officers; (3) correlations between number of programs and self-rated activity levels by government officers; and (4) correlations of number programs with characteristics of cities, towns or villages. RESULTS: The results indicated that the list of programs covered most of the programs. Proposed classification of programs into four domains of social activities which they are most related to agreed with judgments by officials. The number of programs positively correlated with self-rated activity levels by officers for employment and education/training domains in both prefectures; and for social participation/volunteering and individual activities in one of the prefecture. The numbers of programs for employment of the elderly positively correlated with the total population of the community, number of staffs, proportion of people employed in the tertiary industries and total budget for social welfare of the elderly; it negatively correlated with proportion of people employed in the primary industries. CONCLUSION: It is suggested that the list of programs in the questionnaire is applicable and assessment based on the number of programs by four social activity domains is valid to some extent in either prefecture. The questionnaire can be improved further, e.g., by adding other programs to the list.

Aged↗
PubMed1998

[History of autologous blood transfusion in neurosurgical operations].

The first report on predeposit autologous blood transfusion was made in 1921 by F.C. Grant, neurosurgeon in the University Hospital of Pennsylvania. The patient was a 42-year-old man with cerebellar tumor, having a rare blood type for which no donor had been listed up. 500 ml of autologous blood was obtained, kept in 0.2% sodium citrate solution in a refrigerator and retransfused following a suboccipital exploration. Clinically, no reaction was noted and there was a favorable postoperative course, and 'autotransfusion' was evaluated as a life-saving procedure. In 1925, L.E. Davis and H. Cushing reported the first case of intraoperative autotransfusion (intraoperative blood salvage). The patient was a 42-year-old man with left occipital meningioma which, due to massive bleeding, could not be removed even by two-stage operations. In a 3rd stage operation, they could remove the tumor of 120 g totally by the aid of intraoperative replacement using 600 ml autologous blood collected with a home-made suction apparatus. No adverse side-effect was noted. This procedure was performed for 23 cases and it revealed beneficial effects except in one case. In ten of the cases, the procedure was estimated as a life-saving treatment. At the present time, the appropriate use of the patients' blood for transfusion therapy is recommended due to a shortage of donors. The use of autologous blood could play a key role, not only in saving the homologous blood supply, but also in avoiding complications encountered in conventional transfusion treatments. The methods of 'Autotransfusion' originated from operations in the neurosurgical area. On that account, it is desirable that neurosurgeons should be concerned with this subject even now.

Adult↗
PubMed1997

Localization of the squalene epoxidase gene (SQLE) to human chromosome region 8q24.1.

Squalene epoxidase (EC 1.14.99.7) catalyzes the first oxygenation step in sterol biosynthesis and is suggested to be one of the rate-limiting enzymes in this pathway. We previously isolated the mammalian squalene epoxidase cDNAs and demonstrated the transcriptional regulation of human squalene epoxidase by sterols and inhibitors. The present study was undertaken to determine the chromosomal mapping of the human squalene epoxidase gene (SQLE). PCR evidence localizes human SQLE to chromosome 8 by using the NIGMS (National Institute of General Medical Sciences) Human/Rodent Somatic Cell Hybrid Mapping Panel 2 as template. To refine the localization of human SQLE further, PCR on the Stanford G3 Radiation Hybrid Panel was performed. The result shows that human SQLE is most tightly linked to D8S508, which is reported to be located at 8q24.13-qter (lod score 7.87). Moreover, fluorescence in situ hybridization also maps human SQLE to 8q24.1.

Chromosome Mapping↗
PubMed1997

Modulation of E2F activity is linked to interferon-induced growth suppression of hematopoietic cells.

E2F is a heterodimeric transcription factor that controls transcription of several growth-regulatory genes including cdc2. To investigate the mechanism of interferon-alpha (IFN-alpha)-mediated growth suppression of hematopoietic cells, we examined the effect of IFN-alpha on the expression and function of E2F using IFN-sensitive Daudi cells. Down-regulation of E2F-1, a subunit of E2F, was observed after 8 h of culture with IFN-alpha; expression of E2F-4, another subunit of E2F, and DP-1, a heterodimeric partner of E2F, was unaffected. Gel shift assays revealed that the DNA binding activity of free E2F, which is composed of E2F-1 and E2F-4, was inhibited by IFN-alpha. In contrast, IFN-alpha did not affect the DNA binding ability of E2F-1 and E2F-4 in a complex with retinoblastoma (RB) susceptibility gene family proteins including pRB, p107, and p130. IFN-alpha could induce dephosphorylation of pRB, thereby turning active E2F-pRB complexes into transcriptional repressors. Transient chloramphenicol acetyltransferase assays revealed that the activity of the E2F-dependent cdc2 promoter was suppressed by IFN-alpha. These results suggest that the antiproliferative action of IFN-alpha is mediated through the modulation of E2F activity in two different ways: down-regulation of transcriptionally active free E2F and conversion of E2F-pRB complexes into transcriptional repressors.

Antiviral Agents↗
PubMed1997

Elevation of serum creatine kinase during treatment with antithyroid drugs in patients with hyperthyroidism due to Graves disease. A novel side effect of antithyroid drugs.

We describe 4 patients with Graves disease who had abnormal increases of serum creatine kinase (CK) concentrations during treatment with antithyroid medications. Three of the patients experienced myalgia and muscle cramps. All of the patients manifested an increase in serum CK levels 1 to 3 months after the administration of antithyroid drugs. Thyrotropin concentrations and cardiac systolic time indexes during the elevation of serum CK concentrations were not consistent with hypothyroidism. The mechanisms are not obvious, but it is likely that the rapid decrease of thyroid hormones in tissues may temporarily cause hypothyroid states, resulting in alterations in CK concentrations. It is suggested that hasty correction of thyrotoxicosis should be avoided in susceptible patients, unless the thyrotoxic conditions are critical.

Adult↗