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Biomedical subjects

S Kobayashi

Publications and source records attributed to S Kobayashi.

At least 109 records · Page 6Linked to original sources

Observation of D+(s)K- and evidence for D+(s)pi- final states in neutral B decays.

We report the first observation of a B meson decay that is not accessible by a direct spectator process. The channel B(0)-->D(+)(s)K- is found in a sample of 85 x 10(6) BB; events, collected with the Belle detector at KEKB, with a branching fraction B(B(0)-->D(+)(s)K-)=(4.6(+1.2)(-1.1)+/-1.3) x 10(-5). We also obtain evidence for the B0-->D(+)(s)pi(-) decay with branching fraction B(B0-->D(+)(s)pi(-))=(2.4(+1.0)(-0.8)+/-0.7) x 10(-5). This value may be used to extract a model-dependent value of |V(ub)|.

Journal Article↗

Myb-related genes of the Kyoho grape ( Vitis labruscana) regulate anthocyanin biosynthesis.

Partial cDNAs of myb-related regulatory genes were isolated from the tetraploid Kyoho grape ( Vitis labruscana: V. labrusca x V. vinifera) and the expression patterns of the corresponding genes were studied. Since MybA gene expression is closely related to coloring and/or ripening of the berry (expression increases strongly with the commencement of coloring and berry softening, and is detected only in berry skin and flesh), full-length cDNAs for the gene were isolated from a mature-berry cDNA library. Three different species of MybA were identified from the cDNA sequences. Delivery of these cDNAs to somatic embryos of grape led to the induction of reddish-purple spots and UDP-glucose:flavonoid 3- O-glucosyltransferase (UFGT) gene expression in non-colored embryos. The UFGT transcript was not detected in control embryos, while other structural genes for anthocyanin biosynthesis were expressed in both control and pigmented embryos. In addition, introduction of the UFGT gene induced the same reddish-purple spots in embryos. In contrast, treatment with the leucoanthocyanidin dioxygenase (LDOX) gene failed to induce these spots. Our results strongly suggest that MybA genes are involved in the regulation of anthocyanin biosynthesis in the grape via expression of the UFGT gene.

Amino Acid Sequence↗

Pneumococcal purulent genual arthritis after allogeneic bone marrow transplantation.

A 21-year-old male patient with non-Hodgkin's lymphoma (diffuse large T-cell type, clinical stage IV) received allogeneic bone marrow transplantation (BMT) from a partially HLA-mismatched unrelated donor in July 1998 and achieved complete remission. Thereafter, he suffered from chronic graft-versus-host disease (GVHD) and was continuously administered immunosuppressive drugs for a long time. Two years after the BMT, he complained of severe pain in the right knee, which was swollen, and was diagnosed as having pneumococcal purulent genual arthritis. He underwent arthroscopic synovectomy and was administered systemic and intra-articular antibiotics, leading to a gradual improvement. Streptococcal infections are often seen in patients in the late phase after allogeneic BMT because of immunodeficiency associated with chronic GVHD and hyposplenism. Most streptococcal infections are respiratory tract infections and septicemia, and there have been very few reports on cases of purulent genual arthritis. Administration of prophylactic antibiotics and control of chronic GVHD, which is a risk factor of pneumococcal infection, seem to be important to prevent purulent genual arthritis.

Adolescent↗

Measurement of the lifetime difference in D0 meson decays.

We report a measurement of the D0-D macro(0) mixing parameter y(CP) using 23.4 fb(-1) of data collected near the Upsilon(4S) resonance with the Belle detector at KEKB. y(CP) is measured from the lifetime difference of D0 mesons decaying into the K(-)pi(+) state and the CP-even eigenstate K(-)K(+). We find y(CP) = (-0.5+/-1.0(+0.7)(-0.8))x10(-2), where the first error is statistical and the second is systematic, corresponding to a 95% confidence interval -0.030<y(CP)<0.020.

Journal Article↗

Observation of the color-suppressed decay B( 0)-->D(0)pi(0).

We report the first observation of color-suppressed B( 0)-->D(0)pi(0), D(*0)pi(0), D0eta, and D0omega decays, and evidence for B( 0)-->D(*0)eta and D(*0)omega. The branching fractions are B(B( 0)-->D0pi(0)) = (3.1 +/- 0.4 +/- 0.5)x10(-4), B(B( 0) -->D(*0)pi(0)) = (2.7(+0.8+0.5)(-0.7-0.6))x10(-4), B(B( 0) --> D0eta) = (1.4(+0.5)(-0.4) +/- 0.3)x10(-4), B(B( 0) --> D0omega) = (1.8 +/- 0.5(+0.4)(-0.3))x10(-4), and we set 90% confidence level upper limits of B(B( 0) --> D(*0)eta)<4.6 x 10(-4) and B(B( 0)-->D(*0)omega)<7.9 x 10(-4). The analysis is based on a data sample of 21.3 fb(-1) collected at the Upsilon(4S) resonance by the Belle detector at the KEKB e(+)e(-) collider.

Journal Article↗

Production of prompt charmonia in e(+)e(-) annihilation at square root of s approximately equals 0.6 GeV.

The production of prompt J/psi, psi(2S), chi(c1), and chi(c2) is studied using a 32.4 fb(-1) data sample collected with the Belle detector at Upsilon(4S) and at 60 MeV below the resonance. The yield of prompt J/psi mesons in the Upsilon(4S) sample is compatible with that of continuum production; we set an upper limit B(Upsilon(4S)-->J/psiX) < 1.9 x 10(-4) at the 95% confidence level, and find sigma(e(+)e(-)-->J/psiX) = 1.47 plus/minus 0.10 plus/minus 0.13 pb. The cross sections for prompt psi(2S) and direct J/psi are measured. The J/psi momentum spectrum, production angle distribution, and polarization are studied.

Journal Article↗

Observation of B+ --> chi(c0)K+.

Using a sample of 31.3x10(6) BB pairs collected with the Belle detector at the Upsilon(4S) resonance, we make the first observation of the charged B meson decay to chi(c0) and a charged kaon. The measured branching fraction is B(B+-->chi(c0)K+) = (6.0(+2.1)(-1.8)+/-1.1)x10(-4), where the first error is statistical, and the second is systematic.

Journal Article↗

Uveitis in adult patients with poststreptococcal reactive arthritis: the first two cases reported associated with uveitis.

We describe two adult patients with poststreptococcal reactive arthritis (PSRA), both of whom concomitantly developed uveitis. These are the first two cases reported. Because uveitis may result in permanent damage to visual acuity, this complication should be widely recognised in patients with PSRA and antibiotic prophylaxis should be considered for those with recurrent streptococcal infection.

Adult↗

Toxicity of ethacrynic acid in isolated rat hepatocytes.

Ethacrynic acid, a loop diuretic drug, caused lipid peroxidation in isolated rat hepatocytes. The thiobarbituric acid reactive substances (TBARS) formation showed a good correlation with the leakage of glutamic-oxaloacetic acid transaminase (GOT) from the hepatocytes. The addition of antioxidants such as N, N'-diphenyl-p-phenylenediamine (DPPD) and promethazine to the isolated rat hepatocyte suspension containing ethacrynic acid prevented the lipid peroxidation and decreased the GOT leakage to some extent. SKF-525A inhibited the oxidative metabolism of ethacrynic acid and decreased the TBARS formation, suggesting that the lipid peroxidation was caused by the oxidative metabolism. The intracellular reduced glutathione markedly decreased in the hepatocyte suspension containing ethacrynic acid and the hepatocellular protein sulfhydryls were decreased, which was negatively correlated with the GOT leakage. Thus the ethacrynic acid-induced hepatotoxicity was found to be related to the lipid peroxidation and the decrease of cellular protein sulfhydryls.

Animals↗

Evaluation of oestrogen receptor beta wild-type and variant protein expression, and relationship with clinicopathological factors in breast cancers.

We addressed the clinicopathological significance of the oestrogen receptor (ER) beta protein, including an ERbeta variant, ERbetacx, in normal human breast and breast cancer. The reverse transcriptase-polymerase chain reaction (RT-PCR) showed that wild-type ERbeta (ERbetaw) mRNA expression was higher in normal than cancer tissues, and that ERbetacx mRNA was higher in cancer than in normal tissues. Immunohistochemistry of 22 normal breast tissues and 57 breast cancers was performed with three different ERbeta antibodies and one ERbetacx antibody. All normal breast samples showed staining with the three ERbeta antibodies, suggesting that ERbetaw might have a physiological role in oestrogen signalling in the normal breast. In breast cancer, expression of the ERbetaw protein correlated well with the expression of the ERalpha and progesterone receptor (PgR), as well as histological grade (HG), and tended to indicate a better prognosis than when ERbetaw was absent. Thirty-one (54%) breast cancer samples contained ERbetacx, whereas the corresponding tissue for normal breast samples stained positive in only two (9%).

Adult↗

Incidence of peripheral blood eosinophilia and the threshold eosinophile count for indicating hypereosinophilia-associated diseases.

BACKGROUND: A definite threshold of the peripheral blood eosinophile count that indicates the presence of hypereosinophilia-associated diseases has not yet been determined. METHODS: The threshold eosinophile count at which cases of hypereosinophilia-associated diseases (n = 25) can be differentiated from those of bronchial asthma (n = 101) was determined. Then, the incidences of eosinophile counts greater than 1.0 x 10(9)/l or the threshold level, were studied by analysis of 43,805 samples sent to the laboratory, and the diseases associated with the increased counts were determined. RESULTS: The eosinophile count in cases of hypereosinophilia-associated diseases and in those of bronchial asthma were 10.967 +/- 1.680 x 10(9)/l and 0.574 +/- 0.045 x 10(9)/l, respectively (P < 0.001); the threshold was 2.052 x 10(9)/l. The percentages of samples with an eosinophile count of more than 1.0 x 10(9)/l and 2.052 x 10(9)/l were 0.6% and 0.1%, respectively; the latter comprised of 41 samples from 24 patients including eight with hypereosinophilia-associated diseases. The patients with hypereosinophilia-associated diseases had a significantly higher count, and a higher incidence of counts of more than 2.052 x 10(9)/l, than others, including patients with malignancies and symptoms conventionally referred as "atopic diseases". CONCLUSION: Hypereosinophilia-associated diseases are associated with a very high eosinophile count of more than 2.052 x 10(9)/l, which was observed rarely.

Asthma↗

The differences of clinical parameters between small multiple ischemic lesions and single lesion detected by diffusion-weighted MRI.

OBJECTIVES: The cause of small infarction is mainly considered to be intracranial small-vessel disease. However, it is difficult to explain the mechanism of multiple, acute infarctions by small-vessel disease. We examined the differences of clinical parameters between patients with multiple small lesions and single lesion detected by Diffusion-weighted MRI (DWI). MATERIAL AND METHODS: We reviewed the clinical records of 86 consecutive stroke patients with lacunar size ischemic lesions on DWI during the acute stage (within 72 h of onset). The subjects were 55 males and 31 females (mean age 72.4 +/- 9.9 years). Small multiple acute ischemic lesions were defined using the following criteria 1): the lesions were detectable by DWI 2), the diameter of each lesion on DWI was less than 1.5 cm, and 3) more than one vascular territory was involved. Included in the analysis were age, sex, lipoprotein (a) levels, hematocrit, atrial fibrillation (Af), stenosis of middle cerebral artery (MCA), internal carotid artery (ICA) or basilar artery stenosis detected by magnetic resonance angiography (MRA), National Institute of Health Stroke Scale (NIHSS) at admission, and a history of hypertension, diabetes mellitus, hyperlipidemia, and smoking. RESULTS: Twenty-one (24.4%) out of 86 patients with small acute infarctions had multiple acute ischemic lesions. Multiple logistic regression analysis showed that Af and stenosis of ICA or basilar artery were significantly more prevalent in patients with multiple lesions than single lesions. CONCLUSION: Multiple, small lesions visible in DWI are likely to be caused by emboli from heart or atheroma of the large vessels than single small lesion.

Adult↗

Development of rheumatoid arthritis following autologous peripheral blood stem cell transplantation.

A 51-year-old man with non-Hodgkin's lymphoma (NHL) was treated with high-dose chemotherapy followed by autologous peripheral blood stem cell transplantation (PBSCT). Although he had HLA-DRB1 0405 and a positive rheumatoid factor, he was unlikely to develop rheumatoid arthritis (RA) according to diagnostic criteria. However, the patient developed RA 40 days after transplantation. Our experience suggests that the systemic autoimmune disease, RA, may occur in patients with predisposing factors after autologous PBSCT.

Antineoplastic Combined Chemotherapy Protocols↗

Effects of dietary chitosan on fat deposition and lipase activity in digesta in broiler chickens.

1. The effect of dietary chitosan on fat deposition and lipase activity in the small intestinal contents was investigated in broiler chickens fed an adequate or high metabolisable energy (ME) diet. 2. Male broiler chickens at 14 d old were fed on the adequate or high ME diet supplemented with 0 or 50 g/kg chitosan, which has a low viscosity, for 3 weeks. 3. Dietary chitosan did not affect food intake, body weight gain or food efficiency in either dietary ME groups. 4. Dietary chitosan reduced the excessive abdominal fat deposition induced by the high ME diet. 5. Dietary chitosan increased the weight of intestinal contents irrespective of dietary ME concentration. 6. Dietary chitosan decreased the lipase activity per g of small intestinal contents. 7. These results suggest that dietary chitosan with low viscosity decreases lipase activity and fat absorption in the small intestine, consequently resulting in a reduction of fat deposition in broiler chickens. 8. It was concluded that dietary chitosan with low viscosity can decrease body fat deposition without reducing food intake and body weight gain in broiler chickens.

Abdomen↗

Can sedation reduce the cardiac stress during gastrointestinal endoscopy? A study with non-invasive automated cardiac flow measurement by color Doppler echocardiography.

BACKGROUND: Upper gastrointestinal endoscopy (UGIE) may cause some cardiac stress. The effect of sedation on hemodynamics during UGIE has not been fully studied, and therefore the aim of this study was to clarify whether or not sedation can reduce cardiac stress dufing UGIE. METHODS: Eight normal male volunteers undergoing UGIE with sedation (0.1 mg/kg of midazolam) and without it (two endoscopies per volunteer in random order) were monitored throughout the procedure by means of electrocardiogram, blood pressure and peripheral oxygen saturation (SpO2). Cardiac output was measured at six points before, during and after endoscopy from automated cardiac flow measurement by color Doppler echocardiography. Serum norepinephrine, epinephrine, dopamine and ACTH concentrations were measured before and after the examination. RESULTS: No significant differences in heart rate, systolic blood pressure, rate-pressure product, cardiac output and left ventricular work index were observed between the sedated and non-sedated groups. SpO2 hardly changed during endoscopy in the non-sedated group, but decreased slightly in the sedated group (P = 0.075). Although all serum catecholamine concentration changes were within normal limits in both groups, after endoscopy only epinephrine concentration was significantly lower in the sedated group than in the non-sedated group (P = 0.0027). CONCLUSIONS: Conscious sedation with midazolam does not reduce the cardiac stress during UGIE.

Adrenocorticotropic Hormone↗

[Catamenial pneumothorax long-term monitored by serum levels of CA 125; report of a case].

A 46-year-old woman was admitted to our hospital because of the repeating right chest pain. Chest X-ray showed a right pneumothorax. This symptom corresponded with her mensturations and elevated serum levels of CA 125. We diagnosed catamenial pneumothorax. Hormones therapy was not performed because severe side effects. For that reason we performed thoracoscopic surgery. We found many little sized fistulas on diaphragm and blue berry spots on right upper lobe during the operation. She didn't recurrence for 2 years after that operation.

CA-125 Antigen↗

Observation of the decay B --> Kl+l-.

We report a search for the flavor-changing neutral current decay B-->K(*)l+l- using a 29.1 fb(-1) data sample accumulated at the Upsilon(4S) resonance with the Belle detector at the KEKB e+e- storage ring. We observe the decay process B-->Kl+l-(l = e, mu), for the first time, with a branching fraction of B(B-->Kl+l-) = (0.75(+0.25)(-0.21)+/-0.09)x10(-6).

Journal Article↗