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Biomedical subjects

T Nishimura

Publications and source records attributed to T Nishimura.

At least 235 records · Page 13Linked to original sources

Natural killer T cell ligand alpha-galactosylceramide inhibited lymph node metastasis of highly metastatic melanoma cells.

The role of natural killer T (NKT) cells in the prevention of multiple tumor metastasis was examined. The i.v. inoculation of a highly metastatic subline of B16-BL6 (B16-BL6-HM) melanoma cells resulted in the formation of metastatic nodules in lymph nodes in addition to lung, intrapleural cavity, and ovary. However, treatment of the mice with the NKT cell ligand alpha-galactosylceramide (alpha-GalCer) three times from 1 day after B16-BL6-HM melanoma inoculation caused a significant inhibition of multiple metastasis. Lymph node metastasis of B16-BL6-HM was almost completely blocked by alpha-GalCer treatment. This antimetastatic effect of alpha-GalCer was abolished in NKT cell-deficient mice. These results suggest that alpha-GalCer-activated NKT cells played a critical role in the prevention of lymph node metastasis of melanoma cells.

Adjuvants, Immunologic↗

Serotypes of human rotaviruses in 7 regions of Japan from 1984 to 1997.

Human rotavirus (HRV) serotypes were studied from diarrheal stool specimens in children in 7 regions of Japan (Sapporo, Tokyo, Maizuru, Osaka, Kagawa, Kurume, and Saga) from 1984 to 1997 by enzyme immunoassay (EIA) with serotype-specific monoclonal antibodies against serotypes 1, 2, 3, and 4. In addition, reverse transcription-polymerase chain reaction (RT-PCR) was conducted for analysis of "others" which included nonserotypable and mixed-serotype rotavirus specimens by EIA. In 3756 rotavirus-positive specimens, serotype 1 was detected in 2649 (70.5%), serotype 2 in 362 (9.6%), serotype 3 in 232 (6.2%) and serotype 4 in 196 (5.2%). Overall, serotype 1 was predominant from 1984 to 1997, although there were a few cases in which serotype 2, 3 and 4 became predominant based on area and year. The frequency of serotype 1 has gradually increased since 1993. Twenty two, 2, 3 and 1 among 57 specimens of "others" by EIA from Tokyo, Maizuru, Sapporo and Kurume in 1995-1996 and 1996-1997 were determined as serotypes 1, 2, 3, and 9 by RT-PCR, respectively.

Child↗

Lumped constant for deoxyglucose is decreased when myocardial glucose uptake is enhanced.

Quantification of myocardial glucose uptake by positron emission tomography with [18F]fluorodeoxyglucose (FDG) requires the "lumped constant" (LC), which corrects the difference of affinity between glucose and FDG to glucose transporters and phosphorylating system. Since LC was introduced, it has been considered to be constant. However, this has recently been questioned. To elucidate the constancy of LC by other than radioisotope techniques, the accumulation rate of sugar phosphates (d[SP]/dt) was measured in isolated, perfused rat hearts by 31P NMR spectroscopy with 2-deoxyglucose (DG). We postulate alpha as the affinity of DG to transporters and the phosphorylating system relative to that of glucose. Theoretically, alpha is equivalent to LC. We determined alpha by measuring d[SP]/dt at DG concentration ([DG]) = 10, 7, 5, and 3 mmol/l, keeping the total of glucose concentration ([glucose]) and [DG] to 10 mmol/l. When the glucose uptake was enhanced by insulin (10 mU/ml) or stunning, calculated alpha was reduced (insulin stimulated, 0.15; stunning, 0.19) compared with the control (0.59). These results indicate that LC can be evaluated by methods without radiolabeled tracers and is smaller when glucose uptake is augmented.

Animals↗

Plasma alpha1,3-fucosyltransferase deficiency in schizophrenia.

Levels of plasma alpha1,3-fucosyltransferase (alpha1,3FT) were assayed in 44 patients with schizophrenia and in 50 healthy controls. Significantly reduced enzyme activities were observed in patients (p < 0.05) and 4 unrelated patients were found, for the first time in Japan, to be deficient in the enzyme activity. Two point mutations in the coding region of the FUT6 gene encoding plasma alpha1,3FT that were responsible for the inactivation of the enzyme activity were detected in those patients. Genotyping of the Le gene (FUT3) in these patients demonstrated that 2 of them were also FUT3 deficient and were grouped as Lewis- individuals whereas the rest were Lewis+.

Case-Control Studies↗

New method of bladder biopsy using combined aspiration and snare.

A method of multiple random biopsy combined with bladder wall aspiration and snare in bladder cancer is presented. Our method was used on 23 patients with clinically superficial bladder cancer and was found to have advantages in obtaining an adequate amount of tissue with minimal thermal degeneration.

Biopsy, Needle↗

Nuclear localization of gold labeled-hydrocortisone-bovine serum albumin conjugate injected intravenously into the hormone-target cells of rat.

We have suggested in a previous study using 2-nm colloidal gold labeled-testosterone-bovine serum albumin (testosterone-BSA-gold) that 2-nm gold labeled-steroid hormone-BSA conjugates would be a useful tool for analyzing the mechanism of steroid hormone action (39). In this study, we examined whether hydrocortisone-BSA conjugate (hydrocortisone-BSA) showed a similar distribution to radiolabeled hydrocortisone in vivo, by injecting 2-nm colloidal gold labeled-hydrocortisone-BSA (hydrocortisone-BSA-gold) into the rat tail vein. The hydrocortisone-BSA-gold with silver enhancement became visible as silver deposits under electron microscopy in the nuclei of hepatocytes and hepatic stellate cells but not in Kupffer cells in the liver, and in the thymocytes and thymic reticuloepithelial cells in the thymus of a rat killed 2 h postinjection. The percentage of nuclei showing deposits in the non-target cells, the epithelial cells of the seminal vesicle, was similar to the value in the seminal vesicle of a control rat injected with BSA labeled with 2-nm colloidal gold as reported previously. In the hepatocytes and thymocytes of a control rat not injected, the percentages of nuclei showing deposits were similar to those in the rat injected with testosterone-BSA-gold or BSA-gold as reported previously, but lower than those in the rat injected with hydrocortisone-BSA-gold. These results suggest that hydrocortisone-BSA-gold is useful for the morphological study of hydrocortisone target cells, and imply that BSA conjugated with hydrocortisone can enter the target cell nuclei of the rat. The present study further indicates that the fate of gold labeled-steroid hormone-BSA conjugates may be decided at the cell membrane level.

Animals↗

Sustained release liquid preparation using sodium alginate for eradication of Helicobacter pyroli.

We prepared a new liquid preparation for eradication of Helicobacter pylori (HP), and examined drug release in vitro and in vivo. The liquid preparation mainly consisted of a sodium alginate (AG) aqueous solution containing ampicillin (ABPC), an antibiotic drug, or methylene blue, a dye. Drug release was retarded by Ca pre-treatment (0.10 M, 20 s) of the AG preparation in in vitro drug release studies due to gel-formation at the liquid surface. In in vivo experiments, the AG preparations were administered orally to rats. The rats were divided into two groups, with or without pre-administration of ranitidine hydrochloride (RH, an H2-blocker). The total remaining % of ABPC in the stomach was high in the rats administered the AG preparation compared to the ABPC solution. The AG preparation might float in the stomach without adhering to the gastric wall in the rats without pre-administration of RH. The total remaining % of ABPC at 30 min was almost 100% in the RH pre-administration rats administered the AG preparation, and about 80% of the drug existed in fraction 2 (implying adhesion of the preparation on the gastric mucus). At 60 min, the total remaining % in the AG preparation plus Ca (mean 87%) increased about 2-fold compared to that in the AG preparation alone (mean 44%). In this case, a large portion of the remaining ABPC also existed in fraction 2. This preparation may be useful for eradication of HP.

Administration, Oral↗

Low dose synthetic human atrial natriuretic peptide infusion in a patient with mitral stenosis and severe pulmonary hypertension.

The present report concerns a case of very low plasma levels of atrial natriuretic peptide (ANP) accompanying severe pulmonary hypertension due to mitral stenosis. There was remarkable fibrosis in the atrium and ANP secretion may have been insufficient. Low-dose infusion (0.025 microg kg(-1) min(-1)) of synthetic human alpha-ANP infusion was very effective in improving the pulmonary hypertension.

Atrial Natriuretic Factor↗

Expression of a recombinant molt-inhibiting hormone of the kuruma prawn Penaeus japonicus in Escherichia coli.

The crustacean molt-inhibiting hormone (MIH) suppresses ecdysteroid synthesis by the Y-organ. The MIH of the kuruma prawn Penaeus japonicus has recently been isolated and its cDNA cloned. In this study, we expressed the MIH in Escherichia coli to obtain a large quantity of this hormone with biological activity. The MIH cDNA was processed and ligated into an expression plasmid. E. coli was transformed with this plasmid, and then the recombinant MIH (r-MIH) was expressed. The r-MIH was put through the refolding reaction and was purified by reverse-phase HPLC. N-terminal amino acid sequence and time-of-flight mass spectral analyses supported the idea that the r-MIH had the entire sequence. By in vitro bioassay using the Y-organ of the crayfish, the r-MIH was found to be comparable to natural MIH in inhibiting ecdysteroid synthesis.

Amino Acid Sequence↗

Diurnal changes in intraepithelial lymphocytes (IELs) in the small intestine of mice.

Diurnal changes in small intestinal intraepithelial lymphocytes (IELs) were examined in 8- to 10-week-old BALB/cA male mice. The ratio of T cell subsets expressing CD8 alpha alpha homodimer/CD8 alpha beta heterodimer was found to be higher in the dark period than that in the light period. Increased expression of Thy-1.2 on gamma delta T cells was also observed in the light period. No significant changes were found in other subsets. This is the first report to document diurnal changes in the small intestinal IELs in mice.

Animals↗

Effects of ATP and its analogues on [Ca2+]i dynamics in the rabbit corneal epithelium.

Adenosine-5'-triphosphate (ATP) plays a pivotal role in various tissues as an extracellular transmitter. ATP released from nerve endings and/or damaged cells may elicit reactions in adjacent cells. To identify such reactions, we investigated the dynamics of the intracellular calcium ion concentrations ([Ca2+]i) in the rabbit corneal epithelium during ATP-stimulation. Intact epithelial sheets isolated from corneal tissue were loaded with Fura-2, and [Ca2+]i dynamics in each cell layer were analyzed using a digital imaging system (Argus 50/CA). Normal architecture was preserved, suggesting that functional integrity remained intact. Perfusion with HEPES-buffered Ringer's solution containing ATP (10 microM) and uridine-5'-triphosphate (UTP; 10 microM) caused a biphasic [Ca2+]i increase in the superficial layer that manifested itself as a rapid initial spike followed by a long-lasting plateau phase. Adenosine-5'-diphate (10 microM) elevated the [Ca2+]i level, but induced only the initial spike, which was smaller than those induced by ATP and UTP. Adenosine (10 microM) did not elicit any [Ca2+]i changes in the epithelial cells. Suramin (10 microM; a P2 receptor antagonist) blocked the ATP-induced [Ca2+]i increase, whereas the P2X receptor agonists, alpha, beta-methylene ATP (10 microM), 2-methyl-thio ATP (10 microM) and Benzoylbenzoyl ATP (10 microM), did not elicit any increases in [Ca2+]i. In the basal cell layer, ATP-induced [Ca2+]i dynamics were biphasic, while oscillatory fluctuations of [Ca2+]i were induced in the wing cells of the mid layer of the corneal epithelium by ATP stimulation. Ca2+ oscillations were sometimes synchronized among adjacent wing cells, but these waves did not propagate to other cell layers. These results suggest that extracellular ATP elicits a [Ca2+]i increase mainly via P2Y receptors. In addition, synchronized Ca2+ oscillation in the wing cell layer indicates that intracellular events may spread to neighboring cells within the layer.

Adenosine Triphosphate↗

Relationship between development of intramuscular connective tissue and toughness of pork during growth of pigs.

We investigated changes in structures and properties of the endomysium and perimysium during development of semitendinosus muscle in relation to the increase in toughness of pork using samples from neonates to 55-mo-old pigs. The shear force value of pork increased linearly until 6 mo of age, and the rate of increase slowed down thereafter. The secondary perimysium thickened owing to an increase in the number and thickness of perimysial sheets consisting of collagen fibers, which became thicker and wavy with the growth of the pigs. This increase in thickness of the secondary perimysium was correlated significantly with the increase in the shear force value (r = .98). The endomysial sheaths became thicker and denser in the muscle of 6-mo-old pigs. Maturation of the endomysium was accompanied by hypertrophy of muscle fibers. The amount of heat-soluble collagen decreased almost linearly, indicating that nonreducible cross-links between collagen molecules were formed throughout chronological aging. We conclude that thickening of the perimysium is closely related to an increase in the toughness of pork during growth of pigs.

Age Factors↗

Structural changes in intramuscular connective tissue during the fattening of Japanese black cattle: effect of marbling on beef tenderization.

We investigated changes in structures and mechanical properties of the intramuscular connective tissue during the fattening of Japanese Black steers, using the cell maceration method for scanning electron microscopy. During the early fattening period, from 9 to 20 mo of age, collagen fibrils of the endomysium in longissimus muscle associated more closely with each other, and collagen fibers in the perimysium increased in thickness and their wavy pattern became more regular. These changes were closely related to the increase in mechanical strength of the intramuscular connective tissue and resulted in a toughening of the beef during the period. The shear force value of longissimus muscle decreased after 20 mo of age, concomitantly with the rapid increase in the crude fat content. Scanning electron micrographs of the longissimus muscle dissected from 32-mo-old steers clearly showed that the adipose tissues were formed between muscle fiber bundles, that the honeycomb structure of endomysia was partially broken, and that the perimysium separated into thinner collagen fibers. In semitendinosus muscle, in which the crude fat content was lower (P<.05) than that in longissimus muscle, the structure of the intramuscular connective tissue remained rigid at 32 mo of age. The shear force value of the muscle increased even in the late fattening period, from 20 to 32 mo of age. Thus, the development of adipose tissues in longissimus muscle appears to disorganize the structure of the intramuscular connective tissue and contributes to tenderization of highly marbled beef from Japanese Black cattle during the late fattening period.

Animal Husbandry↗

[Long-term prognosis of patients with initial cerebral thrombosis and the MRI findings].

To clarify the relationship between long-term prognosis of patients with stroke and their MRI findings, 103 patients with initial cerebral thrombosis, who survived more than three months after the ictus, were studied for five years. The mean age of 98 patients (T group), who were followed up completely, was 73.1 years-old and 65 were men. The age-matched controls consisted of two groups: 65 subjects, who had hypertension and/or diabetes without a history of stroke (R group), and 85 subjects, who had any hypertension, diabetes and stroke (N group). MRI findings were divided into six categories: 1) types of causative lesion, 2) grades of periventricular hyperintensity (none, rims/caps, patchy, diffuse PVH), 3) number of spotty lesions, 4) presence of silent infarction. 5) ventricular dilatation, and 6) extents of brain atrophy. Types of causative lesion were subdivided into 3 subtypes; infarction of the perforating artery territory (P type), infarction of the cortical artery territory (C type), and brainstem infarction (B type). The presence of vascular risks and dementia, and the extent of activity of daily living (ADL) were assessed. The P, C, and B types were identified by MRI in 46, 36, and 16 of the T group, respectively. Motor impairment, dementia, and an ADL status of complete dependence at discharge were also seen in 84, 44, and 22, respectively. In the T group, 33 patients died during five years, which resulted in a cumulative mortality rate of 33.7% and an annual mortality rate of 8.2%. Based on log-rank analysis, the survival rate of the T group revealed was significantly lower than those of the R and N groups. The recurrent rate in the T group (annual stroke recurrence rate was 4.0%) was higher than in the R and N groups, but stroke recurrence was not the cause of death and two thirds of deaths were due to aspiration pneumonia and/or asphyxia. Cox hazard regression analysis for death due to respiratory diseases showed that the hazard ratios of infarction, patchy PVH, and more than 4 spotty lesions were 8.87 (p < .001), 0.31 (p = .058), and 0.44 (p = .098), respectively. Compared to the survival group, rates of complete dependence in ADL, dementia, and brain atrophy were significantly higher in the death group with low incidences of the P type and patchy PVH, which indicated small vessel disease. These findings suggested that in patients with cerebral thrombosis, even in the chronic phase, care should be taken to prevent pneumonia and/or asphyxia due to bulbar palsy. Furthermore, no MRI findings were distinct predictors of long-term prognosis, although infarction based on the small vessel disease had rather good outcome in terms of respiratory disease.

Aged↗

[Glutathione and cisplatin resistance in head and neck cancer].

UNLABELLED: Since glutathione is considered to be an important mediator of cancer cell resistance to cisplatin-based chemotherapy, we investigated glutathione in head and neck cancer by both laboratory and clinical investigations. MATERIALS AND METHODS: Intracellular glutathione concentration was measured in 7 different cell lines that originated from head and neck cancer and was correlated to their IC50 to cisplatin. Expression of gamma-glutamyl cysteine (gamma-GCS) mRNA was assessed by in situ hybridization and gamma-glutamyl transpeptidase (GGT) expression was assessed with immnunohistochemistry of 56 biopsy specimens from 51 clinical cases. Both these enzymes are important for maintenance of intracellular glutathione concentration. RESULTS: Intracellular glutathione concentration was strongly correlated with cisplatin IC50 (R2 = 0.814, P = 0.0012), suggesting that glutathione plays a major role in cisplatin resistance in head and neck cancer. High gamma-GCS expression was observed in 27 out of 47 specimens (57%), but the response rate to chemotherapy (63%) in the high expression group was not significantly different to the low expression group (P = 0.20). High GGT expression was observed in 32 out of 53 specimens (60%), but the response rate in the high GGT group was not significantly different to that of the GGT group. CONCLUSION: Although intracellular glutathione plays an important role in resistance to cisplatin in head and cancer cell lines, we failed to prove that two enzymes that contribute to the maintenance of intracellular glutathione concentration are predictive factors for the response to cisplatin-based chemotherapy. Since clinical cases are further complicated by interactions of the immune system, involvement of a variety of genes related to oncogenesis, and accompanying drugs such as 5FU, it is very difficult to determine a single factor to predict the response to cisplatin. More precise analysis is necessary to determine how head and neck cancer resists cisplatin.

Carcinoma, Squamous Cell↗

Enhanced myocardial glucose use in patients with a deficiency in long-chain fatty acid transport (CD36 deficiency).

UNLABELLED: CD36 is a multifunctional, 88 kDa glycoprotein that is expressed on platelets and monocytes/macrophages. CD36 also has high homology with the long-chain fatty acid (LFA) transporter in the myocardium. Although platelet and monocyte CD36 levels can indicate a CD36 deficiency, they cannot predict specific clinical manifestations in the myocardium of a given person. We examined the hypothesis that a deficiency in LFA transport augments myocardial glucose uptake in patients with a type I CD36 deficiency. METHODS: Seven fasting patients with a type I CD36 deficiency and 9 controls were assessed by cardiac radionuclide imaging using beta-methyl-p-iodophenyl-pentadecanoic acid (BMIPP) as a LFA tracer and by PET with 18F-fluorodeoxyglucose (FDG). RESULTS: None of the patients with a CD36 deficiency showed myocardial uptake of BMIPP. The percentage dose uptake of BMIPP in these subjects was significantly lower than that in normal controls (1.31+/-0.24 versus 2.90+/-0.2; P < 0.005). PET studies revealed that myocardial FDG accumulation was substantially increased in patients with a CD36 deficiency. Quantitative analysis showed that the percentage dose uptake of FDG in patients with a CD36 deficiency was significantly higher than that in normal controls (1.28+/-0.35 versus 0.43+/-0.22; P< 0.01). CONCLUSION: CD36 functions as a major myocardial LFA transporter and its absence may cause a compensatory upregulation of myocardial glucose uptake.

Aged↗

[CT analysis of mucosal surface dose in intraluminal irradiation for esophageal cancer].

PURPOSE: Balloon applicators are generally used in intraluminal irradiation for esophageal cancer. CT exhibits a distortion of the applicator during treatment. Because little attention has been paid to dose non-uniformity in the esophageal mucosa, we analyzed mucosal surface dose using CT. MATERIALS AND METHODS: Eleven patients with esophageal cancer treated with a double-lumen balloon applicator (balloon length: 15 cm, diameter: 20 mm) were evaluated. Reference dose was prescribed at 5 mm under the mucosal surface. Mucosal surface points were determined from CT images, and relative surface dose to reference dose was calculated. Hot and cold spots were defined respectively, as dose points receiving at least 200% and less than 100% of the reference dose. RESULTS: The mean mucosal dose ranged from 138% to 174%. Mucosal dose was distributed widely from 100% to 199% in 94% of all patients. Hot and cold spots accounted for 5.3% and 0.7% of mucosal dose points, respectively. CONCLUSION: 1) CT analysis exhibited the inhomogeneity of esophageal mucosal dose in intraluminal irradiation. 2) At present, it is acceptable to prescribe the reference dose at 5 mm under the esophageal surface. 3) Balloon applicators should be improved to achieve dose uniformity in the esophageal mucosa.

Aged↗