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Biomedical subjects

Y Tsukada

Publications and source records attributed to Y Tsukada.

At least 37 records · Page 2Linked to original sources
PubMed2000

Treatment of adult Still's disease with dexamethasone, an alternative to prednisolone.

We successfully treated three cases of adult Still's disease (ASD) with dexamethasone. High dose prednisolone, which was initially used to treat these patients, failed to remit the disease in all cases. Although they were resistant to prednisolone, all these patients had remarkable improvements in clinical and laboratory findings after switching to an equivalent dose of dexamethasone. We propose using dexamethasone as an alternative for treating ASD before adding immunosuppressants or disease modifying anti-rheumatic drugs (DMARD), when prednisolone therapy does not suppress disease activity sufficiently.

Adolescent↗
PubMed2000

Adult Still's disease as a paraneoplastic manifestation of breast cancer.

We treated a patient who developed symptoms and findings indistinguishable from those of adult Still's disease as a manifestation of metastatic breast cancer 7 years after treatment for a stage 1 tumor. Although clinical features fulfilled diagnostic criteria for adult Still's disease, examination of a bone marrow biopsy specimen indicated that the apparent adult Still's disease was a paraneoplastic manifestation associated with diffuse marrow infiltration by breast cancer. The fever and polyarthralgia resolved with administration of prednisolone, and antiestrogen therapy with tamoxifen citrate was also started.

Breast Neoplasms↗
PubMed2000

Extracorporeal membrane oxygenation for the management of respiratory failure due to ANCA-associated vasculitis.

We present here two patients whose near fatal respiratory distress was caused by pulmonary hemorrhage, and who were treated successfully by extracorporeal membrane oxygenation (ECMO). The underlying disease was anti-neutrophil cytoplasmic antibody (ANCA)-associated systemic vasculitis. They were initially treated with methylprednisolone pulse therapy along with cyclophosphamide. However, their respiratory failure progressed with a low PaO2/FiO2 ratio (< 100 mmHg) despite mechanical ventilation, and ECMO was initiated. After several days, the pulmonary hemorrhage subsided, and the patients were weaned successfully from ECMO. We suggest that ECMO may be used to manage life-threatening pulmonary hemorrhage in patients suffering from ANCA-associated systemic vasculitis.

Adult↗
PubMed2000

Primary ovarian dysgerminoma in a patient with a germline BRCA1 mutation.

Germline mutations in the BRCA1 tumor suppressor gene are associated with increased risk for the development of ovarian cancer. All such cancers thus far reported have been of the epithelial histologic type. We identified an ovarian dysgerminoma in a 16-year-old woman (proband) with a family history of ovarian cancer during a review of histopathologic characteristics of ovarian cancers from women enrolled in the Gilda Radner Familial Ovarian Cancer Registry. Mutation analysis of DNA from this patient's peripheral blood leukocytes revealed a germline BRCA1 mutation (3312insG). The mutation was also present in the mother with breast cancer, a maternal aunt and a distant cousin with ovarian cancer, and a maternal grandfather and an uncle with skin cancer. The development of the proband's dysgerminoma may be unrelated to her germline BRCA1 mutation. Alternatively, such dysgerminomas may be caused by BRCA1 mutations, but occur so infrequently compared with epithelial cancers that they are seldom identified. Analysis of a larger series of ovarian germ cell tumors may resolve this question.

Adolescent↗
PubMed2000

[Interference by D-mannitol on serum D-arabinitol determination by enzymatic assay].

We examined a disparity in D-arabinitol values between two commercial assay kits, LABOFIT and ARABINITEC-AUTO. The determined values by the former were increased by 26%(y = 0.2643x) because of concomitant D-mannitol, whereas those by our newly developed ARABINITEC-AUTO was increased only by 2%(y = 0.0242x). Of 109 samples, 5 samples were found to contain more than 100 mumol/l of D-mannitol. A clear relation(r = 0.89) was noted between the degree of disparity between measurements by the two methods and D-mannitol concentrations in samples. Thus, we have proved that the disparity is mainly caused by D-mannitol.

Biomarkers↗
PubMed2000

Histopathology of familial ovarian tumors in women from families with and without germline BRCA1 mutations.

Breast cancers from patients with germline BRCA1 mutations show characteristic histopathologic features. However, similar studies of BRCA1-associated ovarian cancers have reported inconsistent findings. Interobserver differences in histopathologic classification are a significant source of variation, and most studies have obtained histopathologic information from pathology reports rather than from review of histopathology slides. We therefore reviewed the histopathology slides and pathology reports to determine histologic type, grade, and stage for cancers of the ovary or peritoneum in 217 women from 126 families enrolled in the Gilda Radner Familial Ovarian Cancer Registry. Peripheral blood DNA from at least 1 affected member of each family was analyzed for BRCA1 mutations, and tumors from BRCA1 mutation-positive families were compared with those from BRCA1-negative families. Of 66 patients from 36 BRCA1-positive families, 64 had ovarian carcinoma, 1 had an ovarian carcinoma in situ, and 1 had a dysgerminoma. Of 151 patients from 90 BRCA1-negative families, 135 had ovarian carcinoma, 10 had ovarian borderline tumors, 3 had ovarian sex cord/stromal tumors, and 3 had primary peritoneal carcinoma. There were fewer grade 1 (P <.001) and stage I (P =.10) cancers in patients from BRCA1-positive families than in patients from BRCA1-negative families. Neither mucinous nor borderline tumors were found in the BRCA1-positive families. Ovarian cancers arising in women from BRCA1-positive families are more likely to be high grade and nonmucinous than cancers arising in women from BRCA1-negative families. The absence of borderline tumors in patients from BRCA1-positive families adds to accumulating evidence that BRCA1 mutations do not play a role in the development of these tumors. HUM PATHOL 31:1420-1424.

Breast Neoplasms↗
PubMed1999

Effects of ammonia on the anaplerotic pathway and amino acid metabolism in the brain: an ex vivo 13C NMR spectroscopic study of rats after administering [2-13C]] glucose with or without ammonium acetate.

The 13C-label incorporation into glutamate, glutamine, aspartate and gamma-aminobutyric acid (GABA) from [2-13C] glucose was measured by 13C nuclear magnetic resonance (NMR) spectroscopy to directly examine the effects of ammonia on the activity of pyruvate carboxylase (i.e., the anaplerotic pathway) and the amino acid metabolism in the rat brain in vivo. Rats were sacrificed by exposure to microwaves at 7.5, 15, 30, and 60 min after an i.v. injection of [2-13C] glucose with or without ammonium acetate. After the injection of ammonium acetate, the brain contents of glutamate, aspartate and GABA had decreased, however, the percentage of 13C enrichment of C3 of glutamine, glutamate and GABA, and C2 and C3 of aspartate had increased. The 13C entered the TCA cycle via pyruvate carboxylase from [2-13C] glucose, labeling the C2 or C3 positions of aspartate, the C2 or C3 positions of glutamate and glutamine, and the C3 or C4 positions of GABA first and second turns of the tricarboxylic acid (TCA) cycle. The C4/C3 labeling ratio in GABA was lower than the analogous ratio in glutamate (C2/C3) and higher than that of glutamine (C2/C3). The order of these ratios (glutamate > GABA > glutamine) was not altered by the injection of ammonium acetate. These findings directly indicate that ammonia increases the anaplerotic pathway and that the 13C-skeletons entered glial glutamine through the anaplerotic pathway flow from glia to neuron. A fraction of the glutamine is used in the direct synthesis of GABA via glutamate, whereas the remaining fraction of glutamine passed through the neuronal TCA cycle before synthesizing GABA.

Acetates↗
PubMed1999

Sulfated sialic acid-polymers inhibit the cytotoxic action of bee and snake venom.

Colominic acid is an alpha2,8-linked sialic acid polymer produced by Escherichia coli. We found that synthetic sulfated-colominic acids (SC) remarkably inhibited the cytotoxicity of bee and snake venom toward mouse fibroblast cells, but colominic acids showed no inhibition themselves, indicating the important role of sulfate groups in the inhibitory activity of SC. Other sulfated carbohydrates such as chondroitin sulfates, heparin and heparan sulfate showed no inhibition. SC also exhibited potent inhibition of melittin, a highly basic peptide, which is a major cytotoxic component of bee venom. SC did not inhibit phospholipase A2 activity in bee venom. This suggests that the inhibition of bee and snake venom by SC is due to inhibition of melittin and cardiotoxin, which is a cytolytic peptide in snake venom, respectively. SC with a higher sulfur content and a larger molecular mass showed more potent activity. The interaction between SC and melittin basically seems an ionic one, however, the conformation of SC is also likely important. For the binding of SC to melittin leading loss of its cytotoxic activity, the sulfate groups of SC must be properly arranged to interact with lysine and arginine residues of melittin molecules, which play an important role in the cytolytic activity. A higher molecular mass of SC substituted with more sulfate groups is required for more obvious inhibition of the cytotoxic activity.

Animals↗
PubMed1999

Neurotransmitter release from the medial hyperstriatum ventrale of the chick forebrain accompanying filial imprinting behavior, measured by in vivo microdialysis.

The imprinting behavior of chicks was quantified as a preference score (correct response ratio) achieved in a running wheel apparatus. A total of 249 chicks were exposed to an imprinting stimulus and tested for stimulus-approaching behavior. The chicks were then classified as good learners (imprinted), poor learners (non-imprinted) and a gray-zone group, those were 46%, 31% and 23% of the total chicks respectively. Using the classified chicks, the acetylcholine (ACh) and glutamate releases from the medial hyperstriatum ventrale (MHV) of the chick forebrains were determined by in vivo microdialysis. The non-imprinted chicks were used as yoked controls. Increases of ACh and glutamate released were observed in the imprinted chicks during exposure to the imprinting stimulus, whereas there were no changes in the release of these neurotransmitters in the non-imprinted chicks during the imprinting exposure. These results might be indicated that cholinergic and glutamatergic synapses which are newly formed as functioning synapses with imprinting stimulus in the MHV are involved in the performance of imprinting behavior.

Acetylcholine↗
PubMed1999

[Development of the quantification method of TTV-DNA and clinical application].

We developed a method to measure the quantity of TTV-DNA. This measurement is based on the principle of the real time PCR method using the TaqMan probe. By measuring the change of the fluorescent intensity caused by FRET, we could detect the amount of TTV-DNA. This method has the characteristics that the possibility of the contamination is very rare when it is compared with the usual PCR method, because the reaction system contains UNG and dUTP. This quantification method is useful for the future research of TTV to study the relationship between this virus and diseases.

Biomarkers↗
PubMed1999

[Detection rate of TTV-DNA in healthy medical workers].

We examined the positive rate in healthy medical workers about TT virus (TTV) which was a new hepatitis virus reported in 1997. The healthy medical workers showed a positive rate of 24%. Because there was no significant difference of the positive rate between the medical workers and general healthy persons we could not conclude that the positive rate was influenced by their profession. Generally it is known that a positive rate changes according to PCR primers used for the measurement. As for TTV as well, it is reported that a positive rate is greatly dependent on the selected region of primer. Therefore, we must pay attention to the evaluation of the positive rate for each assay system, especially using different primers.

Adult↗
PubMed1998

Lobular carcinoma in situ with microinvasion.

Six patients with lobular carcinoma in situ with microinvasion were described in this report. Lobular carcinoma in situ is not known to progress to microinvasive disease. Although this feature is rare, the current under standing that lobular carcinoma in situ is a marker needs to be revised.

Adult↗
PubMed1998

In vivo 3D localized 13C spectroscopy using modified INEPT and DEPT.

The 3D localized 13C spectroscopy methods LINEPT and LODEPT, which are modifications of INEPT and DEPT, are proposed. As long as a 13C inversion pulse (180-degree pulse) is applied at 1/(4J) before the proton echo time in LINEPT and a 13C excitation pulse (90-degree pulse) is applied at 1/(2J) before the proton echo time in LODEPT, the proton echo time can be set to any value longer than 1/(2J) in LINEPT and longer than 1/J in LODEPT. As a result, the proton and the 13C pulses can be applied separately and these proton pulses can be made slice-selective pulses. These localization features of LINEPT and LODEPT were evaluated using a phantom consisting of a cylinder filled with ethanol placed inside another cylinder filled with oil, and localized ethanol spectra could be obtained. In vivo 3D localized 13C spectra from the brain of a monkey could be obtained using decoupled LINEPT, and glutamate C-4 appeared directly after the administration of glucose C-1, followed by the appearance of glutamate C-2, C-3 and glutamine C-2, C-3, C-4.

Animals↗
PubMed1998

Simple and large-scale production of N-acetylneuraminic acid from N-acetyl-D-glucosamine and pyruvate using N-acyl-D-glucosamine 2-epimerase and N-acetylneuraminate lyase.

N-Acetylneuraminate lyase and N-acyl-D-glucosamine 2-epimerase had been cloned and overexpressed in Escherichia coli. Simultaneous use of these two enzymes and feeding of appropriate amounts of pyruvate to the reaction mixture made possible the high conversion of N-acetylneuraminic acid (Neu5Ac) from N-acetyl-D-glucosamine (GlcNAc) with a 77% conversion rate on a molar basis. As a result, 29 kg of Neu5Ac was obtained from 27 kg of GlcNAc. The product was recovered by direct crystallization, and verified as identical to authentic Neu5Ac.

Acetylglucosamine↗
PubMed1998

Increased serum levels of advanced glycation end-products and diabetic complications.

We determined serum advanced glycation end-products (AGE) levels in patients with NIDDM and evaluated the relationship between these levels and diabetic complications. The subjects consisted of 125 patients (mean age, 59.2 +/- 11.1 years, duration of diabetes 11.6 +/- 8.9 years, mean HbA1c, 6.8 +/- 1.0%) with stable blood sugar control. Sixty-three healthy volunteers (mean age, 58.3 +/- 12.7 years) served as controls. Serum AGE were measured by a newly developed ELISA method. Serum AGE levels were significantly higher in the diabetic group compared with the normal control group (7.2 +/- 14.6 vs. 3.3 +/- 1.0 mU/ml, P < 0.05). Significant correlations were seen between serum AGE and the degree of diabetic nephropathy. Serum AGE levels of diabetic patients with proliferative retinopathy were significantly higher than those of patients without proliferative retinopathy (5.7 +/- 1.8 vs. 3.1 +/- 1.0 mU/ml, P < 0.025) in the patient groups whose serum creatinine levels were between 2.0 and 3.9 mg/dl, although serum creatinine levels of both groups were not significantly different. Serum AGE levels reflected the severity of diabetic complications, including nephropathy and retinopathy.

Aged↗