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Biomedical subjects

T Sakata

Publications and source records attributed to T Sakata.

At least 325 records · Page 18Linked to original sources

Feeding modulation by pentose and hexose analogues.

D-Glucosamine (GlcN), N-acetyl-D-glucosamine (GlcNAc) and 2,5-anhydro-D-mannitol (2,5-AM) were infused into the rat third cerebroventricle (icv) to compare their effects on food intake. GlcN (24 mumols/L) accelerated eating, and concomitantly increased plasma glucose, free fatty acids, and glycerol without affecting plasma insulin. GlcN accelerated lateral hypothalamic (LHA), and reciprocally decreased ventromedial hypothalamic (VMH) neuronal activity. Infusion of 12 mumols GlcNAc icv did not affect feeding, but oral administration (1200 mumols/L) induced feeding. The GlcNAc-induced feeding was completely abolished by bilateral truncal vagotomy. Infusion of 2,5-AM dose-dependently induced feeding (P less than 0.01). A maximal dose (24 mumols/L) did not substantially change plasma glucose or insulin. Unilateral 2,5-AM microinfusion (1.2 mumols/L) into the VMH, but not into the LHA, elicited feeding. The characteristic actions of these analogues are useful to clarify central control of food intake and also as probes to examine relations between feeding modulation and energy metabolism in the central nervous system.

Acetylglucosamine↗

Case report: nifedipine-rifampicin interaction attenuates the effect on blood pressure in a patient with essential hypertension.

A 72-year-old woman with 5-year history of essential hypertension developed peritoneal tuberculosis. The patient's hypertension, which had been well-controlled by long-acting nifedipine, deteriorated after the administration of rifampicin, an antitubercular agent. During use of nifedipine and rifampicin, both the peak plasma concentration and the area under the curve of nifedipine decreased markedly to about 40% of those without rifampicin. The findings suggest that rifampicin may increase the elimination of nifedipine, presumably by induction of its hepatic metabolism. Nisoldipine, another calcium antagonist, also failed to lower the patient's blood pressure, when given in combination with rifampicin. Taken together, these findings indicate that more caution should be urged when calcium antagonist is prescribed along with rifampicin.

Adrenergic alpha-Antagonists↗

Charting of daily weight pattern reinforces maintenance of weight reduction in moderately obese patients.

To maintain reduced body weight by behavioral therapy in moderately obese patients, body weight was measured four times daily and charted in a weekly graph. Seventy-two female patients with simple obesity were divided into two groups: 55 patients with appliance of charting of weight pattern (group-I), and 17 patients without the charting (group-II). The percentage of patients followed for 2 years was different between group-I (87%) and group-II (65%) during 2 years after completion of weight reduction therapy interviews (p less than 0.05). Forty-eight of group-I patients succeeded in decreasing their weight by 15.2 +/- 1.5 (mean +/- SEM) kg during the 6.5 +/- 0.8 months of the therapy interviews. They were followed up for 3.8 years with no rebound weight gain. Eleven patients in group-II also succeeded in decreasing their weight by 16.8 +/- 1.9 kg during 7.8 +/- 1.3 months but their body weight rebounded by 9.0 kg during the 2-year followup period. Twelve of 15 male patients with weight charting maintained reduced weight during 4.3 years. It was easier and more effective for obese patients to maintain weight graphs for the longer period than to record no weight graphs. Obese patients could themselves monitor irregular weight patterns produced by overeating and correct the irregularities in food intake and daily lifestyles. This seems to explain why the illustration of daily fluctuations of weight measurements was useful for long-term maintenance of weight reduction.

Adult↗

Antigenic diversity of the S-layer proteins from pathogenic strains of Aeromonas hydrophila and Aeromonas veronii biotype sobria.

The antigenic relatedness of paracrystalline surface array proteins with subunit molecular weights of approximately 52,000 from isolates of Aeromonas hydrophila and Aeromonas veronii biotype sobria belonging to a single heat-stable serogroup was examined. Enzyme-linked immunosorbent assay and immunoblotting with two different polyclonal antisera against surface exposed and non-surface-exposed epitopes of the S-layer protein from A. hydrophila TF7 showed that the S-layer proteins of the mesophilic aeromonads were antigenically diverse. NH2-terminal amino acid sequence analysis of four antigenically different proteins showed that while the proteins were structurally related, they differed in primary sequence. Absorption experiments with heterologous live cells showed that cross-reactive epitopes were in non-surface-exposed regions of the S-layer proteins, while absorption with homologous live cells showed that the immunodominant epitopes of the S-layer protein of strain TF7 were strain specific and exposed on the surface of the native, tetragonal array produced by this strain. Proteolytic digestion of the TF7 S-layer protein with trypsin, chymotrypsin, or endoproteinase Glu-C produced an amino-terminal peptide of approximate Mr 38,000 which was refractile to further proteolytic cleavage under nondenaturing conditions. This peptide carried the immunodominant surface-exposed region of the protein, and chemical cleavage with cyanogen bromide further mapped the portion of these surface-exposed epitopes to a peptide of approximate Mr 26,000, part of which maps within the Mr 38,000 protease-resistant NH2-terminal peptide.

Aeromonas↗

Advance shift of feeding circadian rhythm induced by obesity progression in Zucker rats.

To determine the relation between the circadian rhythm of ingestive behavior and the progression of obesity in Zucker rats, ingestion and ambulation were analyzed at four different developmental stages. The obese rats were disrupted gradually in nocturnal patterns of feeding, drinking, and ambulation with the progression of obesity, although the lean littermates maintained the patterns during whole test periods. Analysis of autocorrelogram revealed that circadian rhythms of those behaviors remained throughout the whole test periods. Least-squares spectrum ascertained the following. 1) The obese made advance shift of acrophases in feeding and drinking circadian cycles, but not in ambulation. 2) Amplitudes in those behavioral measures decreased with the progression of obesity. 3) Mesor in the obese feeding was not affected, although that in the lean feeding decreased. The findings indicate that disruption of the light-dark cycle in ingestion of the obese was not due to disappearance of circadian rhythm but to transformation by both decreased amplitude and advance shift of the circadian cycle.

Animals↗

Histamine and histidine decarboxylase are correlated with mucosal repair in rat small intestine after ischemia-reperfusion.

The aim of this experiment was to demonstrate whether histamine and histidine decarboxylase (HDC) contribute to mucosal repair in small intestine subjected to ischemia-reperfusion (I/R). The superior mesenteric artery was occluded for 15 min followed by reperfusion. In jejunal mucosa, histamine content and HDC activity increased after I/R. Histamine output in mesenteric lymph was also elevated after I/R. These increases in HDC activity, and mucosal and lymph histamine levels were suppressed by pretreatment of alpha-fluoromethylhistidine (alpha-FMH), a suicide inhibitor of HDC. alpha-FMH also attenuated the increase of ornithine decarboxylase (ODC) activity normally observed after I/R. Transport of dietary lipid into lymph markedly decreased at 24 h after I/R, yet it was restored to normal at 48 h after I/R. alpha-FMH inhibitor led to a sustained deficit in lipid transport at 48 h after I/R. This sustained functional impairment in alpha-FMH treated animals was associated with blunted responses of HDC activity and histamine content to I/R. Our results suggest that histamine and HDC contribute to the restoration in mucosal function observed at 48 h after I/R. This response may be related, at least in part, to stimulation of ODC activity by histamine.

Amine Oxidase (Copper-Containing)↗

Inherited heterozygous protein C deficiency and dysfunctional protein S with recurrent venous thrombotic diseases: a study of three generations of a Japanese family.

We describe a rare occurrence of a family affected with venous thrombosis, exhibiting a protein C (PC) deficiency and dysfunctional protein S (PS). The propositus and his father developed recurrent venous-thrombosis. Their PC deficiency was characterized by low levels of both antigen and activity, and their dysfunctional PS was suggested by low PS activities despite the presence of normal free PS antigen. Over three generations, six family members had a PC deficiency, and three had both a PC deficiency and a dysfunctional PS. The mode of inheritance of PC deficiency appears to be autosomal dominant.

Adolescent↗

Qualitative and quantitative estimation of soluble indigestible polysaccharides as substrate for hindgut fermentation by mini-scale batch culture.

Pectin, guar gum, transgalactosylated oligosaccharide and glucose were estimated as substrate for hindgut fermentation by measuring the volume of gas released from a 1 ml scale batch culture using rat cecal contents. The amount of short-chain fatty acids (SCFA) in cultures of glucose and pectin was also measured. The amount of SCFA (Y mumol/culture) or volume of gas released (Y ml/culture) was expressed as an exponential function of incubation time (t) (Y = A+B x (1-e-kt); A, B and k are constants). The amount of potential production of gas and SCFA (B) for glucose was higher than that for pectin and the rate constant of gas and SCFA (k) for pectin was higher than that for glucose. The volume of gas released (ml/culture) correlated positively and linearly with the amount of total SCFA (acetic, propionic and n-butyric acids, mumol/culture). A single regression stood for both glucose and pectin. The gas release followed saturation kinetics. The half maximal concentration and maximal velocity for gas release from pectin were higher than those from other substrates (glucose, guar gum and transgalactosylated oligosaccharide).

Algorithms↗

Circadian rhythm of ornithine decarboxylase activity in small intestine of fasted rats.

The aim of this study was to determine whether the circadian changes in ornithine decarboxylase (ODC) activity of different segments of the small intestine were governed by factors other than food intake. First, the effects of fasting on mucosal ODC activity were examined. The results indicate that mucosal ODC activity in 24 hr and 48 hr fasted rats decreased significantly compared with ad libitum-fed rats. Second, the circadian rhythm of mucosal ODC activity was characterized by measuring mucosal ODC activity in fasted rats at four time points (09:00, 15:00, 21:00, and 03:00 hr; light period: 06:00-18:00 hr). The results from this study indicate that there is a detectable baseline ODC activity in different segments of fasting intestine. In duodenum, mucosal ODC activity was highest at 15:00 hr (light period), a time at which the rat was normally not eating. In jejunum and ileum, mucosal ODC activity increased between 21:00 and 03:00 hr (dark period). The observation that small intestine exhibits a distinct circadian rhythm of ODC activity in fasted rats suggests that not only food but also intrinsic factors can modulate physiologic oscillations in mucosal ODC activity.

Animals↗

[Clinical characteristics and prognosis of renal cell carcinoma. Statistical evaluation of possible determinants for distant metastasis, venous tumor thrombi, and lymph node metastasis].

To clarify the recent clinical characteristics of renal cell carcinomas and to evaluate possible determinants for metastasis and venous tumor thrombi, the authors reviewed data from 99 renal cell carcinoma patients treated at Nagoya University Hospital between 1980 and 1989. According to Robson's classification, stage I tumors were found in 48 patients, stage II in 9, stage III in 16, and stage IV in 26. Incidentally detected tumors appeared to be on the increase in recent years. Grade 1 tumors were significantly associated with low-stage tumors and expansive growth. Univariate and multivariate analyses using a logistic regression model demonstrated that venous tumor thrombi and histological grade were significantly related to distant metastasis. Univariate analysis revealed relative risks of 4.7 for venous tumor thrombus presence (pV1b-pV2 vs. pV0-pV1a, p = 0.005) and 8.5 for histological grade (grades 2 and 3 vs. grade 1, p = 0.04). Local invasion (pT3 vs. pT2a-pTb: a relative risk of 7.5, p = 0.0009) and infiltration pattern (INF beta and INF gamma vs. INF alpha: a relative risk of 11.5, p = 0.002). were associated with venous tumor thrombi. Local invasion (pT3 vs. pT2a-pT2b: a relative risk of 6.6, p = 0.03) was the only significant determinant for lymph node metastasis. The 5-year actuarial survival rate was 60.0% for all 99 patients. The 5-year survival rates for stage I and II tumors were, respectively, 91.8% and 64.8%.(ABSTRACT TRUNCATED AT 250 WORDS)

Carcinoma, Renal Cell↗

Conformational features of the four successive non-Watson-Crick base pairs in RNA duplex.

A tridecaribonucleotide, r(UGAGCUUCGGCUC) doesn't form hairpin or interior loop and forms a double helix of 12 base pairs including the four successive nonstandard base pairs, U.G-U.C-C.U-G.U, in the crystal. Non-Watson-Crick base pairs, G.U and U.C are nicely incorporated in RNA duplex maintaining the regular A-form backbone. There exist the good overlapping between base pairings, U.G and U.C, so as to stabilize the nonstandard base pair track. Hydrogen bond networks involving water molecules in the major and minor grooves to stabilize this mismatch base pairing array, are observed and its conformational features are described.

Base Composition↗

[Case report: chronic aggressive pulmonary sarcoidosis with bilateral cavitation].

A 34-year-old male patient was admitted to our hospital because of progressive exertional dyspnea and weight loss (8 kg in one year). Twelve years previously, he had had an episode of uveitis accompanied with bilateral hilar lymphadenopathy. Scalene node biopsy at that time revealed non-caseating epithelioid granulomas. Four years later, a follow-up chest radiograph showed bilateral fine nodular lesions. The bilateral parenchymal lesions gradually increased in density, and eventually, formed a confluent air-space consolidation containing multi-ocular cavities. On physical examination, the patient was emaciated (Ht 165 cm, Wt 40 kg). Nodular cutaneous lesions were present on his face and elbows. Hypoxemia with hypercapnea (PaO2 56 Torr, PaCO2 51 Torr) was noted. Repeated sputum cultures yielded negative results for acid-fast bacilli, fungi, and other pathological organisms. A transbronchial lung biopsy specimen obtained from near the cavitary lesion revealed non-caseating granulomas compatible with sarcoidosis. Skin lesion biopsy showed similar findings. The cavitation, was therefore considered to be due to ischemic necrosis of confluent sarcoid granulomas. Prednisolone (40 mg daily) was given with a prompt improvement of symptoms including dyspnea, as well as the radiographic abnormalities. We conclude that uncomplicated pulmonary sarcoidosis may rarely develop into an aggressive parenchymal disease with cavitation. It is of importance to differentiate such cases from infectious diseases (tuberculosis, mycosis etc.) because of the need for corticosteroid treatment.

Adult↗

[A case of bucillamine-induced interstitial pneumonia].

Bucillamine [N-(2-mercapto-2-methylpropionyl)-L-cysteine] is an anti-rheumatic drug which was developed in Japan. Interstitial pneumonia induced by bucillamine has been reported in two patients with rheumatoid arthritis. In this report, we describe another patient who developed bucillamine-induced interstitial pneumonia. In August 1990, a 53-year-old man was admitted because of fever, dry cough and dyspnea on exertion (DOE). Five months previously, he had noted polyarthritis, and treatment with bucillamine was started in May 1990. His polyarthritis improved about 2.5 months after starting bucillamine, but he developed fever, dry cough, and DOE in August 1990. Chest X-ray on admission showed diffuse acinar and interstitial shadows predominantly in the bilateral upper lung fields. Pulmonary function tests revealed decreased vital capacity and diffusing capacity. Arterial blood gas (ABG) analysis revealed moderate hypoxemia with PaO2 67 Torr. After stopping bucillamine, the fever, dry cough, and DOE improved gradually, and the abnormal shadows on chest X-ray and ABG analysis showed moderate improvements. Bronchoalveolar lavage studies showed that total cell counts and proportion of lymphocytes were increased, and CD4+/CD8+ ratio of T cell subsets was decreased to 0.56. Transbronchial lung biopsy specimen revealed lymphocytic alveolitis and mild interstitial thickening. Lymphocyte stimulation test to bucillamine was negative, but patch test with bucillamine was positive. From the patient's clinical course, laboratory data, and pathologic findings, we concluded that this is a case of bucillamine-induced interstitial pneumonia. After treatment with corticosteroid, his chest X-ray and pulmonary function test showed marked improvements.(ABSTRACT TRUNCATED AT 250 WORDS)

Anti-Inflammatory Agents, Non-Steroidal↗

[Hairy cell leukemia successfully treated with deoxycoformycin].

A 45-year-old male was hospitalized on September 2, 1989 with chief complaints of general fatigue and fever. Physical examination revealed hepatomegaly and massive splenomegaly. Laboratory tests on admission showed Hb of 7.5g/dl, PLT 4.8 x 10(4)/microliters and WBC 9,610/microliters with 81% hairy cells. Bone marrow aspirate demonstrated 55.1% hairy cells and moderate myelofibrosis. Cytochemically, hairy cells were positive for tartrate-resistant acid phosphatase (TRAP). Surface markers were SmIg G+ A+ kappa +, CD11b+, CD11c+, CD19+, CD20+, CD21-, CD25+, HC2+, HLA-DR+. From these findings, a diagnosis of hairy cell leukemia (HCL) was made. After administration of deoxycoformycin (DCF) at a dose of 5.0mg/m2 1-2 times monthly, splenomegaly disappeared, as did hairy cells from the peripheral blood. Hematological level returned to within normal range except for the presence of 1.2% hairy cells and mild myelofibrosis in bone marrow aspirates. DCF has so far been effective for this patient. While DCF has been reported to be effective in the treatment of HCL in the West, it has not been determined in Japanese patients with HCL, who have different hematologic features from those of HCL patients in the West.

Humans↗

[Clinical study of bronchial inhalation challenge in summer-type hypersensitivity pneumonitis induced by Trichosporon cutaneum].

To evaluate the methods and criteria of judgement for the bronchial antigen inhalation challenge test, the test was performed with culture filtrate antigen of serotype I and II of Trichosporon cutaneum in 18 patients with summer-type hypersensitivity pneumonitis from 15 families. The quantity of 15 mg of culture filtrate antigen was adequate, and had no side effects. In the tests, 17 of 18 patients showed a positive reaction to both or either, serotype of antigen. In 36 performances of inhalation, there were 21 positive reactions and 15 negative reactions. According to the criteria of judgment for inhalation challenge test, the positive response rates of observation items were 75% for symptoms and signs, and 51% for laboratory data. Items with a high positive rate were cough, crepitant rales, and decrease of PaO2. On the other hand, low positive rates were observed for decrease of DLco, VC and positive CRP. Items with both high sensitivity and high specificity were cough, crepitant rales and decrease of PaO2. The low positive rate of decreased DLco was due to insufficient improvement before inhalation challenge. It was concluded that our methods and criteria of judgment for bronchial inhalation challenge test are useful.

Adolescent↗

[Clinical evaluation of usefulness of cefixime (200 mg administered once daily) in the treatment of acute uncomplicated cystitis].

A comparative study of cefixime (CFIX), a new oral cephem antibiotic, was carried out at the Department of Urology, Nagoya University Hospital and its four affiliated hospitals to evaluate the clinical efficacy and safety of two dosage regimens of CFIX, given either in twice daily doses (BID group) or once daily dose (UID group), in the treatment of acute uncomplicated cystitis. Forty six female patients (BID group) were administered the daily dose of 200 mg in two divided doses for 3 days, 30 female patients (UID group) were administered 200 mg once daily for 3 days. The clinical efficacy was evaluated in 33 cases from the BID group and in 22 cases from the UID group, respectively, according to the criteria recommended by the Japan UTI Committee. In the BID group, the clinical efficacy was evaluated as excellent in 18 cases, moderate in 13 and poor in 2, with an overall clinical effectiveness rate of 94%. In the UID group, it was evaluated as excellent in 9 cases, moderate in 12 and poor in 1, with an overall clinical effectiveness rate of 96%. Safety was monitored in 71 patients, and only one case of stomatitis was seen in the UID group. This findings suggest that 200 mg once daily dosing regimen of cefixime is as effective as 100 mg twice daily dosing regimen in treatment of acute uncomplicated cystitis, and is well tolerated in terms of safety.

Acute Disease↗

Changes in coagulation factors by passage through a dextran sulfate cellulose column during low-density lipoprotein apheresis.

To determine the extent of adsorption of coagulation factors by a dextran sulfate cellulose column used for selective removal of low-density lipoprotein (LDL), various coagulation factors were measured before and after application to the column during LDL apheresis. The column almost completely adsorbed many coagulation factors. Although the bradykinin concentration was markedly increased by passing the plasma through the column, this increment was suppressed by nafamostat mesilate which inhibits the initial contact phase of the intrinsic coagulation pathway. The von Willebrand factor, which forms a complex with factor VIII in plasma, is reduced in apheresis with nafamostat mesilate to the same extent as in apheresis without nafamostat mesilate. Thus, coagulation factors seem to be adsorbed by different mechanisms which include activation of the initial contact phase by the negative charges of dextran sulfate and concomitant adsorption with the phospholipid portion of lipoproteins containing apolipoprotein B or with von Willebrand factor.

Adolescent↗