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T Tomiyasu

Publications and source records attributed to T Tomiyasu.

At least 19 recordsLinked to original sources
PubMed2001

Risk of irregular menstrual cycles and low peak bone mass during early adulthood associated with age at menarche.

BACKGROUND: The risk of irregular menstrual cycles and low peak bone mass of the lumbar spine in young adult women, associated with age at menarche, has not been clearly defined. The aim of this study was to investigate this further. METHODS: A total of 180 college females aged 20-23 years were surveyed about menstruation, exercise, and calcium intake by means of a questionnaire. We also measured vertebral bone mineral density in these women by dual energy X-ray absorptiometry. The subjects were divided into six groups according to their age at menarche. Comparisons were made of the mean body mass index (BMI) and T-scores (the ratio to the mean bone mineral density of young adult Japanese women) among those groups, and odds ratios of irregular menstrual cycles and low peak bone mass less than 87% (- 1 standard deviation (SD) of T-scores were calculated using the mean menarcheal age (12 years) group as a control. RESULTS: The mean BMI and T-scores were significantly lower in delayed menarche groups (equal to or more than 13 years) compared with early menarche groups (equal to or less than 12 years). The odds ratios of irregular menstrual cycles were 5.9 (95% confidence intervals (CI) 1.7-20.6), 13.7 (95% CI 3.6-51.6), and 73 (95% CI 6.5-813.9) in the 13-, 14-, and more than 14 years menarcheal age groups, respectively. The odds ratio of low peak bone mass less than 87% (- 1SD) was 3.4 (95% CI 1.1-10.3) in the 14 years menarcheal age group. CONCLUSIONS: Young adult women with delayed menarche may be at high risk for irregular menstrual cycles and low peak bone mass.

Absorptiometry, Photon↗
PubMed2001

Determination of trace amounts of total arsenic in environmental samples by hydride generation flow injection-AAS using a mixed acid as a pretreatment agent.

A method is described for the determination of total arsenic by hydride generation-atomic absorption spectrophotometry using a mixed acid as a pretreatment. Hydride generation is done by the flow-injection method. The authors investigated in detail the temperature and time of decomposition using inorganic, organic arsenic and environmental standard samples, pretreated with nitric-perchloric-sulfuric mixed acid. By using a mixed acid as a pretreatment agent at 220 degrees C, the decomposition time could be shortened and the blank value of arsenic from the reagents used was reduced. The mixed acid of nitric-perchloric-sulfuric was also found to be effective as a pretreatment agent for organic arsenic compounds in which a dimethylated compound, sodium cacodylate or biological samples, is known to be one of the indecomposables. The present approach was proved to be satisfactory as a pretreatment for the quantitative analysis of trace amounts of total arsenic in liquid or solid environmental samples, such as geothermal water, sediments and biological samples.

Acids↗
PubMed2001

A kinetic method for the determination of nitrite by its catalytic effect on the oxidation of chlorpromazine with nitric acid.

A catalytic spectrophotometric method for the determination of trace amounts of nitrite is proposed. In acidic solution, chlorpromazine (CP) is oxidized by nitric acid to form a red compound, which is further oxidized to a colorless compound. The reaction is accelerated by trace amounts of nitrite and can be followed by measuring the absorbance at 525 nm: nitrite ion is regenerated and multiplied by nitric acid. The absorbance of the reaction increased with an increase in the reaction time, reached a maximum and decreased rapidly. Since the time required for the absorbance to reach the maximum decreased with increasing nitrite concentration, this value was used as the measured parameter for the nitrite determination. Under the optimum experimental conditions (2.3 M nitric acid, 1.2 x 10(-5) M CP, 40 degrees C), nitrite can be determined in the range 0-100 microg l(-1). The relative standard deviations (n = 6) are 4.7 and 1.8% for 40 and 100 microg l(-1) nitrite, respectively. The detection limit of this method (3sigma) is 1.2 microg l(-1). This method was successfully applied to a determination of nitrite in natural water samples.

Antipsychotic Agents↗
PubMed2000

Detection of localized methylmercury contamination by use of the mussel adductor muscle in Minamata Bay and Kagoshima Bay, Japan.

Based on our previous finding that the concentrations of total mercury in mussel adductor muscle approximated those of methylmercury, we compared concentrations of total mercury in the adductor muscle of the mussel Mytilus galloprovincialis, collected from four sites around Minamata City from 1993 to 1995 and four sites in Kagoshima Bay from 1997 to 1998, to assess the level of localized methylmercury contamination. Though the input of mercury from the chemical plant had stopped by around 1970, concentrations of total mercury in the mussel adductor muscle were higher at two sites (26-121 ng/g, n = 135) near the main fallout of wastewater from the chemical plant in Minamata Bay than at the other sites, i.e. two sites 1-5 km from the former sites in Minamata City (6-28 ng/g, n = 52), and all sites in Kagoshima Bay (2-30 ng/g, n = 287). The localized methylmercury contamination around the chemical plant in Minamata Bay was documented also by our sensitive analysis of mercury concentrations in seawater and sediment samples. The survey of concentrations of total mercury in the mussel adductor muscle seems to be useful for monitoring the methylmercury contamination in coastal areas.

Animals↗
PubMed2000

Background levels of atmospheric mercury in Kagoshima City, and influence of mercury emission from Sakurajima Volcano, Southern Kyushu, Japan

Vapor phase mercury concentration was determined daily for 1 year (Jan. 1996-Jan. 1997) in order to present the levels of atmospheric mercury in Kagoshima City and to estimate the influence of mercury emission from Sakurajima Volcano, southern Kyushu, Japan. The atmospheric mercury was collected on a porous gold collector at Kagoshima University and was determined by cold vapor atomic absorption spectrometry; Kagoshima University of Kagoshima City is located approximately 11 km west of Sakurajima Volcano. The mercury concentration obtained was in the range 1.2-52.5 ng m(-3) (mean 10.8 ng m(-3), n = 169). The atmospheric concentration varied from season to season; the concentration was high in summer and lower in winter. A linear relation was obtained by plotting ln[Hg/ng m(-3)] vs. 1/T for the north, south and west winds with correlation coefficients of -0.76, -0.79 and -0.83, respectively, but no such dependency was found for the east wind (r = -0.035). When the wind is blowing from the east, Kagoshima City is on the leeward side of the volcano. The impact of the fumarolic activity of the volcano on ambient air in the city was evident in the disappearance of temperature dependency with the appearance of the east wind. Atmospheric mercury concentration except for the east wind was considered to be background levels of Kagoshima City. As background levels, 8.1 +/- 5.3 ng m(-3), 14.8 +/- 7.9 ng m(-3), 13.9 +/- 11.7 ng m(-3) and 4.4 +/- 1.6 ng m(-3) (mean +/- S.D.) were obtained for spring, summer, autumn and winter, respectively.

Journal Article↗
PubMed2000

Mercury contamination in the Yatsushiro Sea, south-western Japan: spatial variations of mercury in sediment.

Mercury-contaminated effluent was discharged into Minamata Bay from a chemical plant over a 20-year period until 1965 (from 1958 to 1959, effluent was discharged into Minamata River), causing Minamata disease. In an effort to characterize the extent of the contamination in the Yatsushiro Sea, the vertical and horizontal distributions of mercury in sediment were investigated. Sediment was sampled at 62 locations in the southern part of the sea from 4 to 6 March 1996. In the lower layers of the long cores of sediment, the total amount of mercury was at a relatively uniform low concentration. We interpret these low values to represent the background concentration absent of anthropogenic influence. The background value thus estimated for the Yatsushiro Sea was 0.059 +/- 0.013 mg kg(-1) (mean +/- S.D., n = 51). The highest concentration in each sample ranged from 0.086 to 3.46 mg kg(-1) (mean, 0.57 mg kg(-1)). The higher values were obtained at stations near Minamata Bay and the Minamata River (the sources of the pollution). Concentrations decreased with distance from the source. An inspection of the vertical profiles of mercury concentration in cores suggested that the deposited mercury had not been fixed in sediment but had been transported, despite 30 years having past since the last discharge of contaminated effluent. At nine stations, extractable inorganic and organic mercury concentrations were determined differentially. Inorganic mercury is the predominant species in sediment and organic mercury comprising approximately 1% of the total.

Chemical Industry↗
PubMed1999

Pregnancy-associated osteoporosis with elevated levels of circulating parathyroid hormone-related protein: a report of two cases.

Two lactating women who had complained of back pain developed spontaneous vertebral fractures with low bone mineral density (BMD) several months postpartum. The back pain and biochemical abnormalities presented as hypercalcemia and elevated plasma levels of the parathyroid hormone-related protein (PTH-rP) that returned to normal indices with increasing BMD after weaning. The increased circulating PTH-rP might contribute to the pregnancy-associated osteoporosis in women who probably are already osteopenic.

Absorptiometry, Photon↗
PubMed1999

Remission of idiopathic hypoparathyroidism during lactation: a case report.

A 35-year-old woman with idiopathic hypoparathyroidism achieved a spontaneous remission during lactation even though 1-alpha-hydroxyvitamin D3 therapy was discontinued after delivery. Urinary excretion of cyclic adenosine 3',5'-monophosphate and phosphate was significantly increased during lactation, probably in response to the increased levels of circulating parathyroid hormone-related protein derived from the breast tissue.

Adult↗
PubMed1998

Magnesium deficiency in adult rats promotes the induction of ventricular tachycardia by the administration of epinephrine.

The effects of magnesium deficiency on epinephrine-induced ventricular tachyarrhythmia were investigated in adult rats. Forty-two adult Wistar rats were fed a magnesium-deficient diet while 30 rats were fed a standard diet for 20 days. The plasma magnesium concentration was lower in the magnesium-deficient rats (0.22+/-0.01 mmol/l) than in the control rats (0.76+/-0.03 mmol/l, P < 0.001). Using a telemetry system, electrocardiograms and arterial blood pressure were recorded on a polygraph in an unrestrained condition. Epinephrine was infused intravenously starting at 5 microg/kg per minute. The QT interval was prolonged to 50+/-1 ms in the magnesium-deficient rats compared with 44+/-1 ms in the control rats (P < 0.001). Before the administration of epinephrine, no ventricular tachyarrhythmias or seizures were found in either the control or the magnesium-deficient rats. The incidence of epinephrine-induced sustained ventricular tachycardia (VT) was higher in the magnesium-deficient rats (86%) than in the control rats (43%, P < 0.01). However, this VT did not result in sudden death. Seizures always preceded death in both the magnesium-deficient and control rats while the arrhythmias observed immediately before death were mainly bradyarrhythmias. The present study in an adult rat magnesium-deficient model revealed that magnesium deficiency enhances the susceptibility to epinephrine-induced ventricular tachyarrhythmias.

Animals↗
PubMed1991

[A case report of advanced gastric cancer responsive to radiotherapy and CDDP arterial injection].

A 48-year-old-male patient with advanced gastric cancer, which extended from corpus to antrum of the stomach and metastasized to the left lobe of the liver, was treated with radiotherapy combined with CDDP arterial injection. Total irradiation and CDDP dosage was 50 Gy/25 f and 150 mg (75 mg/mal/body), respectively. The regression of the tumor was remarkable. For inoperable advanced gastric cancer, radiotherapy combined with anticancer drugs proved a worthwhile therapy, and it was necessary to use the pharmacological characteristics of the drugs.

Adenocarcinoma↗
PubMed1990

Isochromosome (8q) in four patients with adenocarcinoma of the lung.

We report an isochromosome, i(8q), in combination with many other cytogenetic changes in tumor cells from four patients with lung cancer. In each case, the tumor subtype was adenocarcinoma. This isochromosome has not been identified in primary tumors from patients with other histological types of lung cancer. Among the few previously reported cytogenetic analyses of pulmonary adenocarcinomas, i(8q) has been observed in four additional patients. Therefore, i(8q) represents a recurring change in this specific type of lung cancer. In addition to i(8q), tumor cells from each of our four patients had different abnormalities of 17p, and two patients had alterations of 3p as well.

Adenocarcinoma↗
PubMed1990

An adherent subline of a unique small-cell lung cancer cell line downregulates antigens of the neural cell adhesion molecule.

Small-cell lung cancer (SCLC) lines are distinguished from non-small-cell lung cancer (NSCLC) lines by their growth in floating aggregates, in contrast to the adherent monolayers formed by NSCLC cells in culture. Of 50 well-characterized SCLC lines recently described by the National Cancer Institute (NCI)-Navy Medical Oncology Branch, only four variant cell lines (SCLC-v) grew as adherent monolayers. One line, NCI-H446, was unique in growing long-term with coexisting floating and surface adherent subpopulations. We have physically segregated these two populations over many passages in vitro to enrich for relatively pure cultures of floating and adherent cells. No differences in c-myc expression, keratin pattern, or cytogenetic appearance were found between the adherent and floating sublines. However, expression of the neuroendocrine marker neuron-specific enolase in the floating cells was three times that found in the adherent cells. The floating subline also had much greater surface expression of neuroendocrine tumor antigens detected by monoclonal antibodies UJ13A and HNK-1, which have been recently shown to detect the neural cell adhesion molecule (NCAM) on SCLC cells. Two other adherent SCLC-v lines were also found to be unreactive with UJ13A and HNK-1, generalizing the association between NCAM expression and the growth of most SCLC cultures as floating aggregates. In conclusion, we have an interesting model to study expression of NCAM as related to the adhesive properties of SCLC cells.

Antibodies, Monoclonal↗
PubMed1990

Clinical and cytogenetic correlations of abnormal megakaryocytopoiesis in patients with acute leukemia and chronic myelogenous leukemia in blast crisis.

It has been suggested that abnormalities of chromosome 3 at bands q21 and q26 are associated with the presence of increased numbers of abnormal megakaryocytes in patients with hematologic malignancies. The pretreatment bone marrows of 287 patients with leukemia (acute myeloid leukemia (AML), 225 patients; acute lymphocytic leukemia (ALL), 36 patients; or chronic myelogenous leukemia in blast crisis (CML-B), 26 patients) were reviewed to identify those with normal or increased numbers of megakaryocytes. Thirty-two patients with AML, one with ALL, and 10 with CML-B had normal or increased numbers of megakaryocytes. Of the 32 patients with AML, 19 patients had significant numbers of mononuclear or binuclear small megakaryocytes as well as megakaryocytes with separated nuclei ("micromegakaryocytes"). Cytogenetic analyses were obtained in 29 of 32 patients with AML and showed inv(3)(q21q26) (one patient); Ph1 (two patients); -5 and/or -7 (seven patients); normal karyotypes (10 patients). No patient with micromegakaryocytes had a chromosomal abnormality associated with a favorable prognosis. Overall, among 225 patients with AML, four had inv(3)(q21q26) or t(3;3)(q21;q26). Only one of these four patients had normal or increased numbers of megakaryocytes, although all four had micromegakaryocytes. One patient with CML-B had inv(3)(q21q26) but had decreased numbers of megakaryocytes and a platelet count of 24 x 10(3)/microliters. All five patients with abnormal chromosome 3 at bands q21 and q26 had additional cytogenetic abnormalities (Ph1 in two patients; -7 in three patients). Mean and median platelet counts were greater than 100,000/microliters for patients with marrow megakaryocytosis regardless of morphology, as well as for the patients with abnormalities involving 3q21 and 3q26. Abnormalities of megakaryocyte morphology, increases in the numbers of megakaryocytes, and normal to increased platelet counts are not uncommon in patients with acute leukemia and CML-B, and are not uniquely associated with changes involving chromosome 3.

Adult↗
PubMed1989

Establishment and characterization of a clonal human T-cell line, MKB-1 derived from a patient with acute myeloblastic leukemia.

A human T-cell line, designated as MKB-1, was established by cloning procedures in a suspension culture from a peripheral blood of a 17-year-old female patient with acute myeloblastic leukemia. The immunological marker profile of MKB-1 indicated that unlike a myeloid phenotype of the original leukemic cells, the cells were positive for CD3 (both cell surface and cytoplasm), T cell receptor (TcR) alpha/beta heterodimer, CD4, CD5, CD7, CD10, CD57 (Leu7), SN-1 and the cytoplasmic TcR beta chain. These findings indicate the T cell nature of the established cells. Terminal deoxynucleotidyl transferase (TdT) was also detected in 60%. We did not detect markers of human myeloid and B cell associated antigens, HLA-class II or immunoglobulin chains. Cytogenetic study revealed that the MKB-1 cells had a female hypo-tetraploid karyotype with chromosomal abnormalities including a translocation between chromosomes 10 and 14. The breakpoint of chromosome 14 of this translocation, 14q11.2, is known to be the location of TcR alpha and delta genes; t(10; 14) (q26; q11.2) is a variant type of a T cell neoplasm-associated translocation, t (10; 14) (q24; q11.2). The MKB-1 cell line is unusual in that its T cell characteristics are phenotypically and cytogenetically distinct from the original myeloid leukemia cells.

Adolescent↗
PubMed1989

Prognostic impact of cytogenetic abnormalities in patients with de novo acute nonlymphocytic leukemia.

Detailed cytogenetic analyses were performed on specimens from 198 patients with de novo acute nonlymphocytic leukemia (ANLL), including high-resolution banding studies in 79 patients. One hundred ninety-two patients received induction therapy with daunorubicin and cytosine arabinoside (Ara-C) with an overall complete response rate (CR) of 63%. Responding patients received repetitive cycles of Ara-C-based intensification therapy. Clonal abnormalities were detected in 69% of the patients with specimens adequate for cytogenetic analysis. Certain cytogenetic changes were closely associated with French-American-British (FAB) morphology, age, and outcome: t(8;21) (closely associated with FAB M2), t(15;17) (associated with FAB M3), and abn 16q22 (associated with FAB M4EOS) tended to occur in younger patients and were associated with favorable outcomes in terms of both CR rate and long-term disease-free survival. In contrast, 19% of patients who had -5/5q- and or -7/7q- and seven patients with trisomy 8 were older, had a poor prognosis, and usually failed to achieve remission (CR) because of chemotherapy-resistant leukemia. The adverse effect on CR rate and duration in this group of patients was independent of age, and there was no association with particular morphologic subtypes. These data suggest that cytogenetic findings should influence future therapeutic choices. In particular, patients with abnormalities associated with poor responses may be considered for investigational approaches and may also provide insights into mechanisms of drug resistance.

Adolescent↗
PubMed1988

Application of ethidium bromide for high-resolution banding analysis of chromosomes from human malignant cells.

Ethidium bromide was added to cultured human leukemic bone marrow and solid tumor cells to evaluate its inhibitory effect on mitotic chromosome condensation and its possible application to high-resolution banding analysis. In most experiments ethidium bromide treatment resulted in a high proportion of mitotic cells having elongated chromosomes, without remarkable reduction in either the mitotic index or quality of metaphase chromosomes. Optimal effect on chromosome length was obtained by adding 10 micrograms/ml of ethidium bromide during the final 2 hr of culture. Because of the simplicity and reproducibility of the technique involved, ethidium bromide can be used routinely to extend the length of chromosomes for fine-banding analysis of malignant cells.

Chromosome Banding↗
PubMed1983

Cytogenetic characterization of ten cases of Ph1-positive acute myelogenous leukemia.

Chromosome banding analyses were made on 10 cases of Ph1-positive AML (7 M1 and 3 M2). The standard type Ph1 translocation, t(9q +;22q -), was identified in all of them. Karyotypically normal cells were observed in 6-65% of bone marrow metaphases at the initial cytogenetic examination of 7 patients, whereas the remaining 3 patients had only Ph1-positive cells at diagnosis. Follow-up studies performed in 5 cases indicated that the frequency of karyotypically normal cells increased up to 81-100% when the patients were in remission, whereas it was much reduced in relapse. In 5 cases, there was observed a clone of cells in which the Ph1 translocation was the sole karyotypic abnormality. Various types of other chromosome abnormalities, in addition to the Ph1, were observed in all cases, among which-7 was the most frequent, being found in three cases as a stem line. Other additional changes encountered were + Ph1, del(5), i(17q), - 10, + 18, + X, and various numerical and structural changes including certain secondary translocations that occurred in the Ph1 (22q -) or its partner (9q +). The types and frequencies of these additional changes appeared to be different from those found in the acute phase of CML or in Ph1-positive ALL.

Adult↗