Biomedical subjects

H Ohta

Publications and source records attributed to H Ohta.

At least 217 records · Page 12Linked to original sources

PubMed1999

[ERPs changes during neuroleptic treatment in schizophrenia--a vulnerability marker in schizophrenia].

P300 amplitude reduction and P300 latency prolongation are consistent findings in schizophrenia, but it is unclear if these abnormalities were the effect of current or past neuroleptic treatment or were present at the onset of illness. We previously recorded ERPs in drug free schizophrenic patients (45 neuroleptic-naive and 56 previously treated with neuroleptics). In that study, P300 amplitude reduction was observed in both the neuroleptic-naive and the previously treated patients. However, both N200 and P300 latencies were prolonged only in the previously treated schizophrenic patients. In this study, we investigated ERPs in 60 drug free schizophrenic patients before and after neuroleptic treatment was begun. According to DSM-IV, schizophrenia subtype classification, 26 cases were paranoid type, 14 were disorganized, 2 catatonic and 18 undifferentiated. Twenty six of the patients were neuroleptic-naive and 34 had been previously treated. Sixty gender- and age-matched healthy controls were also investigated. ERPs were recorded during an auditory oddball task. The scalp EEGs were recorded from AgAgCl electrodes at 16 sites according to the international 10-20 system. Clinical symptoms were assessed using the Brief Psychiatric Rating Scale (BPRS). Before treatment, all schizophrenic patients displayed larger N200 amplitudes than the controls; however, increases in N200 amplitudes were not observed after neuroleptic treatment was begun. Both N200 and P300 latencies in the patients before treatment were prolonged only in those previously treated. Neuroleptic-naive patients demonstrated prolongation of both N200 and P300 latencies only after treatment. P300 amplitudes in patients were increased by neuroleptic treatment; but patients had smaller P300 amplitudes than the controls even after treatment. The change in P300 amplitudes (Pz) and the change in total BPRS scores by neuroleptic treatment were positively correlated in the patients whose duration of illness was six months or less (mean: 2.4 months). However, no correlation was observed for patients whose duration of illness was over six months (mean: 49.7 months). There were no significant differences in ERPs changes among subtypes. These results suggested that the P300 amplitude should be considered a vulnerability marker in schizophrenia and that both N200 and P300 latencies might be markers for neuroleptic exposure.

Adult↗

PubMed1999

[Combined multimodal therapy for osteosarcoma--neoadjuvant chemotherapy].

Until the 1970s, the survival rate of osteosarcoma patients was less than 20%. By the 1990s, this had improved to 60% to 70%, and limb-sparing procedures have replaced amputation in many patients thanks to effective combination therapy. Neoadjuvant chemotherapy has become an accepted practice in the majority of institutions using protocols which include MTX, ADR, BCD and CDDP as the most active agents against this disease. Newer agents, particularly IFM and ETP, are increasingly incorporated into complex regimens. While several studies have reported multivariate analyses to identify prognostic factors, the histologic response to preoperative chemotherapy remains the most important prognostic factor. Pulmonary metastases are the primary cause of death in patients with osteosarcoma. Although current treatment regimens allow effective salvage therapy for the patients with pulmonary metastases, the actuarial survival rate is 30%. A more effective systemic treatment for those patients is needed. The current management of osteosarcoma is critically reviewed and a treatment strategy is proposed for discussion.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1999

[Clinical study on liver metastasis of AFP-producing gastric cancer--characteristic findings of angiography].

We studied 6 patients with liver metastasis of AFP-producing gastric cancer, especially about the angiography and treatment. The angiographic findings of liver metastasis are characteristic in 3 patients. Multiple rounded hypervascular tumor are seen in the arterial phase and its vessels are fine. In the venous phase, the tumor is homogeneous. We called the findings "Fireworks like stain". These patients were treated with TAE and responded it.

Aged↗

PubMed1999

[Lead].

Explore the source record for details and available documents.

Adult↗

PubMed1999

[Partial liver resection with small skin incision for multidisciplinary treatment of hepatocellular carcinoma].

Hepatocellular carcinoma (HCC) is likely to be detected as multiple intrahepatic metastases, and trans-arterial embolization (TAE) is the treatment of choice. However, other therapy is needed when TAE is not effective for a tumor. We performed partial liver resection with small skin incision in two such patients. One patient had two HCCs of segment 6 (S6) and S7, and TAE was performed twice. However, HCC of S7 was viable, and we partially resected the tumor of S7. In the other patient, HCC was multiple in segment 6 and 7. TAE was performed three times, and in segment 6 we detected a tumor which grew into the extrahepatic space and seemed uneffected by TAE. We performed a partial resection of liver segment 6. After 3 months, TAE was repeated in the latter. The operation time was about three hours, and no blood transfusion was performed. Two of the patients were discharged on the 13th postoperative day. We concluded that partial liver resection with small skin incision was useful for one case of multidisciplinary treatment for hepatocellular carcinoma.

Aged↗

PubMed1999

[A case of massive bloody stool caused by Meckel diverticulum in which 99mTc-HSA-DTPA SPECT was useful].

A 15-year-old boy was admitted to our hospital because of massive bloody stool. At the age of 11 years, he had two episodes of massive bloody stool, and 99mTcO4- Meckel scintigraphy failed to contribute to the diagnosis. On this admission, 99mTc-HSA-DTPA scintigraphy, especially coronal SPECT clearly showed bleeding site. Operation revealed Meckel diverticulum. We showed the usefulness of coronal SPECT in the evaluation of gastrointestinal bleeding.

Adolescent↗

PubMed1999

One-step direct assay for mature-type adrenomedullin with monoclonal antibodies.

Adrenomedullin (AM) is a potent hypotensive peptide. Plasma contains mature-type AM (m-AM), which is amidated at the carboxy terminus, and an intermediate, AM-Gly. We developed a one-step two-site IRMA specific for determining human m-AM with monoclonal antibodies. The detection limit was 0.5 pmol/L, and the working range (CV <15%) was 1-300 pmol/L. Dilution of plasma samples showed good linearity. The recovery of added AM was 91-118%. The intra- and interassay imprecision values (CVs) were 4.4-8.2% and 5.5-8.3%, respectively. The assay had no cross-reactivity with AM-Gly or other peptides similar to AM. The mean (+/- SD) plasma human m-AM concentration of 61 healthy subjects was 1.18 +/- 0.65 pmol/L. In conclusion, our IRMA makes it possible to specifically measure m-AM, using a small amount of plasma sample (0.2 mL) by a one-step overnight assay without prior extraction. Our simplified method would be suitable for clinical studies on AM, especially when large numbers of samples must be processed.

Adrenomedullin↗

PubMed1998

Downregulation of mRNA expression of Edg-3, a putative sphingosine 1-phosphate receptor coupled to Ca2+ signaling, during differentiation of HL-60 leukemia cells.

We measured the mRNA expression of the recently identified putative sphingosine 1-phosphate (S1P) receptors, i.e., Edg-1, AGR16/H218, and Edg-3, in HL-60 leukemia cells. Of these putative receptors, Edg-3 mRNA was abundantly expressed in undifferentiated HL-60 cells. Further, its mRNA expression was markedly downregulated by inducers of cell differentiation such as dibutyryl cAMP, retinoic acid, and 1alpha, 25-dihydroxyvitamin D3. The reduction of mRNA expression was associated with the attenuation of an S1P-induced increase in cytoplasmic free Ca2+ concentration. Thus, Edg-3, whose mRNA expression is downregulated during cell differentiation, may be responsible for the S1P-induced Ca2+ response in HL-60 leukemia cells.

3T3 Cells↗

PubMed1998

Transcript of a homolog of aflR, a regulatory gene for aflatoxin synthesis in Aspergillus parasiticus, was not detected in Aspergillus oryzae strains.

Some strains of Aspergillus oryzae were shown to have homologs of aflR, a regulatory gene for aflatoxin synthesis in Aspergillus parasiticus. Transcription of an aflR homolog was examined in six strains of A. oryzae having the homologs, using polymerase chain reaction (PCR) coupled with reverse transcription. No PCR product was obtained when the RNA prepared from the A. oryzae strains cultivated under aflatoxin-producing condition was used as template for amplification of the aflR cDNA. By contrast, a PCR product of the expected size was obtained with RNA from A. parasiticus NIAH-26 processed by the same procedure. From genomic DNA of these strains, PCR products of the same size as above were obtained. Possible degradation of the aflR mRNA in the RNA preparation of the A. oryzae strains was negligible, because the calmodulin transcript was detected by PCR from the same RNA samples. Thus, the aflR homologs in the non-aflatoxigenic A. oryzae strains examined are not expressed even under aflatoxin-producing condition.

Aflatoxins↗

PubMed1998

In vitro effects of gonadotropin-releasing hormone (GnRH) analogue on cancer cell sensitivity to cis-platinum.

Six endometrial cancer cell lines (Ishikawa, EIIL, HEC1A, 6, 50 and 59), one breast cancer cell line (MCF-7) and two ovarian cancer cell lines (OVHS-1, HRA) were treated for 24 or 168 h with a gonadotropin-releasing hormone (GnRH) analogue, Buserelin acetate, and the cellular growth profile was studied. All these cell lines except for the HRA line had positive GnRH receptor mRNA expression detected by reverse transcriptase polymerase chain reaction. GnRHa suppressed cell growth after 168 h of exposure, but not after 24 h. Suppression of cell growth by the exposure to cis-platinum (CDDP, 10 nM for 24 h) was significantly increased in the presence of GnRHa for 168 h. The mechanism of this growth inhibition was tested by examining both RNA components of human telomerase (hTR) expression and telomerase activity. The results showed that GnRHa inhibits telomerase activity without altering the RNA component of telomerase expression. The present data suggest that GnRH analogue may modulate endometrial, breast and ovarian cancer cell growth through modifying the telomerase activity. Since GnRHa increased the cytotoxic effects of CDDP and GnRHa is a compound of high patient compliance, the value of GnRHa as a tumor sensitizer to CDDP should be further tested in clinical trials.

Antineoplastic Agents↗

PubMed1998

Effect of cation-exchange pretreatment of aqueous soil extracts on the gas chromatographic-mass spectrometric determination of nerve agent hydrolysis products after tert.-butyldimethylsilylation.

The efficiency of pretreatment of aqueous soil extracts using a cation-exchange resin has been investigated by gas chromatographic-mass spectrometric (GC-MS) determination of nerve agent hydrolysis products after tert.-butyldimethylsilyl (TBDMS) derivatization. An aqueous solution containing methylphosphonic acid (MPA) and its monoalkyl esters, ethyl methylphosphonic acid, isopropyl methylphosphonic acid and pinacolyl methylphosphonic acid, was dried, and these phosphonic acids were derivatized with N-methyl-N-(tert.-butyldimethylsilyl)trifluoro-acetamide and analyzed by GC-MS. The yields of TBDMS derivatives were significantly decreased by the addition of calcium and magnesium ions to an aqueous solution (approximately 0.5 mM) before derivatization. The extent of lowered yields was related to the hydrophilicity of phosphonic acids. MPA and its monoalkyl esters were spiked into soil samples (sand, alluvial soil and volcanic ash soil), extracted with distilled water, dried, silylated and applied to GC-MS. The yields of TBDMS derivatives of monoalkyl esters from soil samples were low (3-42%) and MPA derivative was scarcely detected (yield: < 0.7%). By desalting the aqueous soil extract by passage through a strong cation-exchange resin, the yields of TBDMS derivatives of monoalkyl esters were significantly improved (12-69%) and MPA derivative was detected (yield: 2-36%). The extent of improved yields was related to the concentrations of divalent metal cations in aqueous soil extracts. In combination with desalting by the cation-exchange resin, GC-MS after TBDMS derivatization enables detection of nerve agent hydrolysis products in soils at sub-ppm (0.2 microgram/g) concentrations.

Acetamides↗

PubMed1998

Relationship between dermato-physiological changes and hormonal status in pre-, peri-, and postmenopausal women.

We previously reported that hormonal changes in perimenopausal women are associated with dermatologic changes. In the present study, we evaluated such dermatologic changes by means of dermato-physiological testing methods in perimenopausal women with various types of hormonal conditions. The study group consisted of 46 consecutive women 41-70 years of age (mean, 54.0 years), attending a climacteric outpatient clinic for a healthy check-up is whom no abnormalities were recognized. The women were divided into four groups according to menstrual history and sex-related steroid hormone values: a premenopausal group (n = 9); a perimenopausal group (n = 8); an early menopausal group, in which 5 years or less had elapsed since menopause (n = 12); and a late menopausal group, in which 6 years or more had elapsed since menopause (n = 17). We found that: (1) after menopause the sebum cutaneum content of the forehead decreased significantly, but that of the subocular region was unchanged; (2) the water content of the stratum corneum of the forehead was significantly higher in the late menopausal group than in the premenopausal group and the perimenopausal group, but there were no significant differences among the four groups at the other sites studied; (3) on psychological stimulation, sweat production was found to decrease significantly after menopause; (4) the skin temperature of the forehead and cheek fell significantly after menopause, but that of the nose, back of the foot, and tips of the toes, did not differ significantly among the four groups; (5) The perimenopausal period was associated with increased skin permeability and vascular responsiveness; (6) fingertip plethysmography revealed significant decreases in peripheral circulatory function in the perimenopausal group and the late menopausal group.

Adult↗

PubMed1998

Determination of Aconitum alkaloids in blood and urine samples. II. Capillary liquid chromatographic-frit fast atom bombardment mass spectrometric analysis.

Determination of fourteen alkaloids, toxic Aconitum alkaloids, aconitine, mesaconitine, jesaconitine, hypaconitine and deoxyaconitine, and their hydrolysis products, benzoylaconines and aconines, have been established using capillary liquid chromatography (LC) fast atom bombardment mass spectrometry (FAB-MS) with a frit interface. Protonated molecular ions were observed as base peaks in the FAB-MS for these fourteen alkaloids. All the alkaloids were simultaneously quantified with linear gradient LC elution by solvent mixture of acetonitrile and 0.3% trifluoroacetic acid using selected ion monitoring of the protonated molecular ions. The calibration curves of these alkaloids were linear in injection amounts ranging from 5 to 500 pg, and their detection limits were 1 pg per injection (S/N=3). Solid-phase extraction using Sep-Pak Plus PS-1 was also investigated to clean-up and concentrate alkaloids in blood and urine samples, and showed satisfactory recoveries. This capillary LC-frit-FAB-MS method enables determination of low levels of Aconitum alkaloids in blood and urine samples, coupled with solid-phase extraction.

Aconitine↗

PubMed1998

A missense mutation of the gene for Na+,K(+)-ATPase alpha-subunit causes abnormal feeding behavior in Caenorhabditis elegans.

The Na+,K(+)-ATPase activity of membranes from a behavioral mutant of C. elegans was found to be about one-third that of the wild-type. The levels of mRNA and polypeptide of Na+,K(+)-ATPase alpha-subunit in the mutant were as high as those in the wild-type, but the level of the phosphorylated intermediate of the Na+,K(+)-ATPase in the mutant worm was 80% lower than that in the wild-type. A single predicted amino acid replacement (Leu to Phe) was found in a highly conserved region in the alpha-subunit that is involved in the formation of phosphorylated intermediate. The abnormal feeding behavior of the mutant worm may be attributed to this missense mutation.

Amino Acid Sequence↗

PubMed1998

Association of the Trp64Arg mutation of the beta3-adrenergic receptor with fatty liver and mild glucose intolerance in Japanese subjects.

The prevalence of a mutation of the codon for tryptophan 64 to arginine (Trp64Arg) in the beta3-adrenergic receptor gene was investigated by genotyping 261 Japanese subjects. The allelic frequency of this mutation was 0.18. Subjects with the homozygous W64R mutant alleles had a significantly higher prevalence of fatty liver, BMI, serum gamma-glutamyl transpeptidase, and serum leucine amino transpeptidase levels than those without the mutation. Individuals with this mutation also showed a higher fasting blood glucose level than those without this mutation. However, the prevalence of diabetes mellitus was no different between the three groups. These results suggest a potential association of the Trp64Arg mutation with higher morbidity of fatty liver and mild glucose intolerance.

Alleles↗

PubMed1998

Influence of bilateral oophorectomy upon lipid metabolism.

OBJECTIVES: Reduction in serum level of estrogen has been thought to result in hyperlipidemia which triggers atherosclerosis, and even to lead to cardiovascular diseases, in postmenopausal women. The present study was designed to investigate the influence of bilateral oophorectomy (OPX), which induces as much reduction in serum estrogen level as menopause, upon lipid metabolism, especially the serum levels of total cholesterol. METHODS: In 31 OPX subjects and 31 age- and body size-matched premenopausal controls, the serum levels of total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), very low-density lipoprotein (VLDL-C), apoprotein-A1 (Apo-A1), apoprotein-B (Apo-B), lipoprotein lipase (LPL) and lipoprotein-a [LP(a)] were measured as indices of lipid metabolism and the index of arteriosclerosis was calculated. RESULTS: TC level was significantly higher in the OPX group than in the premenopausal control group, being 8995 +/- 244 (mean +/- S.E.) mmol/l and 7757 +/- 228 mmol/l, respectively. LDL-C and Apo-B levels and the index of arteriosclerosis were all significantly higher in the OPX group than in the premenopausal control groups. However, there were no significant intergroup differences with regard to HDL-C, Apo-A1, LPL and LP(a). CONCLUSIONS: The above results demonstrated that, in spite of no reduction in HDL-C, the blood levels of Apo-B, LDL-C and TC change due to OPX. These changes suggest OPX induces cardiovascular diseases and, therefore, follow-up of the changes in lipid metabolism is required, paying special attention to Apo-B and LDL-C.

Apoproteins↗

PubMed1998

Effect of a HMG-CoA reductase inhibitor combined with hormone replacement therapy on lipid metabolism in Japanese women with hypoestrogenic lipidemia: a multicenter double-blind controlled prospective study.

OBJECTIVES: Menopause is associated with a rise in serum lipid concentrations. We compared a regimen of pravastatin alone with pravastatin and hormone therapy in postmenopausal women with hyperlipidemia. METHODS: We performed a double-blind, randomized, multicenter controlled study in postmenopausal women with hyperlipidemia. The women were randomly assigned to receive pravastatin alone (M group; n = 25) or pravastatin and hormone replacement therapy (HRT) (MC group; n = 32) for 12 weeks. Serum lipid and estrogen concentrations were measured at baseline and after 4 weeks and 12 weeks of treatment. RESULTS: The two groups were similar with respect to baseline demographic characteristics such as age, height, and body weight. As compared with baseline, the total cholesterol (TC) concentration was 15.0% lower at 4 weeks and 17.7% lower at 12 weeks in the M group and 15.1% lower at 4 weeks and 18.3% lower at 12 weeks in the MC group. The low-density-lipoprotein cholesterol (LDL-C) concentration decreased by 25.0% at both 4 weeks and 12 weeks in the M group and by 26.8% at 4 weeks and 30.0% at 12 weeks in the MC group. Serum TC and LDL-C concentrations were significantly lower in the MC group than in the M group after 4 weeks of treatment, but there was no significant difference between the groups in serum lipid concentrations after 12 weeks. Pravastatin combined with HRT was therefore suggested to lower serum lipid concentrations earlier than pravastatin alone. There were no significant differences between the treatment groups in serum high-density-lipoprotein cholesterol concentrations or triglyceride concentrations after the initiation of therapy. In the MC group, there was a significant positive correlation between the percentage change in serum lipid concentrations and that in estrogen concentrations, suggesting that the HRT-induced rise in estrone (E1) as well as that in estradiol (E2) contributed an improved serum lipid profile. TC and E2, and LDL-C and serum E1 had significant negative correlation at 12 weeks and 4 weeks, respectively. Pravastatin had no apparent effect on endogenous estrogen levels and was not associated with any side effects, which confirmed that pravastatin is safe, either alone or in combination with HRT. CONCLUSIONS: The combination of pravastatin and HRT in the management of hyperlipidemia in postmenopausal women is very useful therapeutically, because it additionally provides the broad benefits of HRT, without compromising the lipid lowering effects of either treatment.

Cholesterol↗

PubMed1998

Homolog of a-factor receptor gene in Saccharomyces exiguus.

Homologs of Saccharomyces cerevisiae STE3, a-factor receptor gene were detected from S. exiguus NFRI 3539 by low stringency Southern hybridization. This strain might have at least two types of homolog. One of these homologs, designated as e-STE3 was cloned. Its nucleotide sequence revealed 60% identity to STE3. The putative protein coding region consisted of 453 amino acid residues. The amino acid sequence identity between STE3 and e-STE3 was 62% and that of the N-terminal 303 amino acid residues considered to be the pheromone binding domain was 79%.

Amino Acid Sequence↗