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Biomedical subjects

T Sakata

Publications and source records attributed to T Sakata.

At least 379 records · Page 21Linked to original sources

[Statistical study of tumors of the renal pelvis and ureter].

We reviewed data from 62 patients with epithelial tumors of the renal pelvis and ureter who were hospitalized and treated at Nagoya University Hospital between July, 1970 and June, 1988. Of the 62 patients, 50 were males and 12 were females, the ratio being 4.2:1. The mean age was 62.1 years, the ages ranging from 41 to 87 years. The peak incidence of tumors was marked in the sixth decade for the males and in the seventh decade for the females. Eighty-two percent of the patients were 50 years of age or older. Smoking habits were noted in 76.0 percent of the males and in 16.7 percent of the females. Asymptomatic macrohematuria, found in 43 patients, was the most frequent symptom. Ninety percent of the 62 tumors were transitional cell carcinoma. Twenty-five patients (40.3%) had concomitant bladder cancer, which was previously diagnosed in 3, simultaneously found in 9, and subsequently developed in 16. Twenty-nine patients had tumors localized in the renal pelvis and eighteen in the ureter; the remaining fifteen had tumors localized in two or three organs, including the renal pelvis, ureter and bladder. Histological grades of ureteral tumors were significantly higher than those of renal pelvic tumors. The sensitivity of urinary cytology was 57.8 percent. High-grade tumors had higher sensitivity than low-grade tumors. Larger tumors (greater than 3 cm in diameter) were significantly associated with high-stage tumors, whereas no apparent correlation was found between tumor size and histological grade. Nonpapillary growth of tumor and vascular invasion were significantly related with high-stage and high-grade tumors; diffuse pattern of tumor infiltration was associated with high-stage tumors.

Adult↗

Conformation and properties of hammerhead-type RNA enzymes.

We designed a hammerhead-type RNA enzyme system which consists of three ribooligonucleotide strands (1-3), synthesized these oligomers and their analogues, and examined conformation and properties of the RNA complexes. Imino proton NMR spectra of the complexes were measured and the signals were assigned by comparison with the spectra of some model duplexes. Examination of a complex containing a G----I mutation (Y = I) revealed that the 2-amino group of the third guanosine residue in the loop 1 (L1) plays an important role for maintaining both the activity and loop conformation.

Base Sequence↗

[A case of mild obesity accompanied by epicardial fat deposition].

A 61-year-old woman with low grade obesity index complained of general fatigue. Cardiomegaly had been present since the age of 45. According to a roentgenogram on admission, her cardia-thoracic ratio was 61%. Pericardial effusion was strongly suspected because of extra echo spaces on both posterior and anterior walls, and unsynchronized echocardiograph waves of epicardium and pericardium. However, values of dynamic CT measured at areas equivalent to the extra echo spaces were -120. On admission, T1-emphasized MRI image showed a high signal density in those areas. After significant weight reduction, the abnormal values and signs of the clinical examinations, as well as the patient's complaints were attenuated or disappeared. Together with these results, cardiomegaly of the patient was diagnosed to be due to excessive fat deposit between the epicardium and cardiac muscle. Dissociation between mildness of obesity index and excessive deposition of fat in the pericardium was discussed from the point of view of body mass index and time course of fat deposition.

Adipose Tissue↗

[Study of chromogenic substrate on protein C activity assay--in patients treated with warfarin].

Protein C is an anticoagulant protein that circulates in blood as a zymogen of a serine protease. Recently the exogenous Protein C activator has been obtained from the venom of Agkistrodon Contortrix Contortrix. We also reported a functional assay method which activates Protein C with PROTAC and then measure the amidolytic activity with chromogenic substrate (S-2366) by COBAS FARA. At present, S-2366 (Glu-Pro-Arg-pNA), CBS 65-25 (Lys-Pro-Arg-pNA) and SPECTROZYME PCa (Lys-Pro-Arg-pNA) are used as the chromogenic substrate for activated Protein C. We studied which substrate is more suitable for amidolytic activity assay for Protein C by PROTAC in 99 patients under long-term Warfarin therapy and 29 as normal subjects. Our results indicate that SPECTROZYME PCa and CBS 65-25 are unsuitable for Protein C activity assay with PROTAC. Because change of absorbance was detected in Protein C deficient plasma and we couldn't gain good correlation between amidolytic activity of activated Protein C measured with these chromogenic substrates and antigenicity of Protein C by EIA. On the other hand, S-2366 is the most specific for activated Protein C and we also obtained good correlation against Protein C antigen.

Chromogenic Compounds↗

[Granulomatous prostatitis after intravesical BCG immunotherapy of superficial bladder cancer: a case report].

We report a case of granulomatous prostatitis after intravesical BCG immunotherapy for superficial bladder cancer. A 58-year-old man presented with gross hematuria. Cystoscopic examination revealed multiple tumors at the posterior wall of the bladder. The patient underwent transurethral resection of the tumor. Intravesical BCG immunotherapy was postoperatively followed and it eradicated the disease. Digital examination revealed that the prostate became stony-hard and larger 10 weeks after the initial BCG immunotherapy. A needle aspiration cytology and biopsy of the prostate revealed the granulomatous prostatitis due to BCG immunotherapy.

Administration, Intravesical↗

[A case of nephrotic syndrome with abnormally high level of protein C induced by prednisolone].

Adrenocortical hormones have been used for nephrotic syndrome from 1950. But effects of these drugs in coagulation and fibrinolysis are unknown in detail. We studied the effect of prednisolone in a patient with nephrotic syndrome. Protein C increased remarkably after administration of prednisolone 40 mg/day and then decreased in parallel with the dose of prednisolone. Factor X increased more slowly than Protein C. On the other hand, we couldn't find increase of Protein S. Our results indicate that prednisolone have anticoagulant effect by promotion of production of Protein C.

Blood Coagulation↗

Comparative analysis of the proliferative response of the rat urinary bladder to sodium saccharin by light and scanning electron microscopy and autoradiography.

Three methods used to detect proliferative changes in the rat urothelium, light microscopy, scanning electron microscopy, and autoradiography, were compared for their sensitivity in detecting changes produced by administration of sodium saccharin. Weanling male F344 rats were fed sodium saccharin as 0, 3, 5, or 7.5% of the diet, and the bladders were evaluated after 4, 7, and 10 wks of feeding. Light microscopic changes and an increase in labeling index were seen at all time points in rats fed 7.5% sodium saccharin, but not at the lower doses. A slight increase in labeling index was also observed at 10 wks in the 5.0% group. Scanning electron microscopic changes were evident as early as 4 wks with increasing severity at the 3, 5, and 7.5% doses. This study demonstrates that the hyperplastic response of the urothelium to sodium saccharin administration varies with dose and time, and that observation by scanning electron microscopy is the most sensitive of the three methods evaluated for detecting these changes.

Animals↗

[NK- and T-cell granular lymphocyte-proliferative disorders].

For the disease of the granular lymphocytes (GL) that contain azurophilic granules to proliferate in the peripheral blood, which is often complicated by anemia or neutropenia and which generally develop into chronic disease, the new designation of granular lymphocyte-proliferative disorders (GLPD) is being proposed. This disease include T-GL having CD3 antigen which forms a complex with T cell Ag receptor (TCR-alpha beta), and NK-GL which is CD3-negative but CD16- or NKH-1-positive, having non-MHC-restricted cytotoxicity. The two cases presented here demonstrate the characteristics of T-GL or NK-GL, however, while one case with NK-GL showed spontaneous decrease of GL, improvement of neutropenia and anemia without any treatment, the other case with T-GL became intractable and required repeated blood transfusion. On such differences in the clinical development of the disease, we have conducted investigations including a review of the literature to see whether there is any correlation between the characteristics of the proliferating cells and pathologic conditions of the disease, and whether this disease is indeed tumorous.

Aged↗

Influences of diet and strain on the proliferative effect on the rat urinary bladder induced by sodium saccharin.

Rats were fed sodium saccharin as 5 or 7.5% of the diet by weight, and proliferation of the bladder epithelium was assessed by autoradiography, histology, and scanning electron microscopy. In Experiment 1, male F344 rats, 5 weeks old, were placed on a diet of 0, 5, or 7.5% NaS mixed in Prolab 3200, NIH-07, or AIN-76A diet for 4 or 10 weeks. In Experiment 2, 5-week-old F344 rats or 4-week-old Sprague-Dawley rats were fed 0, 5, or 7.5% NaS in Prolab 3200 or Purina 5002 diet for 10 weeks. In Experiment 1, at both the 4- and 10-week intervals, NaS had a greater effect on the urothelium when administered in the Prolab diet compared to the NIH diet, and there was little response with the AIN diet. Eight of 10 rats fed 7.5% NaS in Prolab 3200 for 4 or 10 weeks had bladders with simple or nodular hyperplasia, and eight of nine bladders contained abnormal surface features visible by scanning electron microscopy. At 10 weeks for control animals, the average labeling index following [3H]thymidine incorporation into bladder epithelium was approximately 0.05%. For rats fed 7.5% NaS diets, the labeling index was 0.43% for Prolab, 0.14% for NIH-07, and 0.04% for AIN-76A. In Experiment 2, the response to NaS was considerably greater in F344 rats than in Sprague-Dawley rats fed the same diet, and for both strains, the response to NaS was greater in Prolab than in Purina diets. In conclusion, the proliferative effect of NaS on male rat urinary bladder depended on rat strain as well as on type of diet.

Animals↗

Hypothalamic sites of neuronal histamine action on food intake by rats.

To identify sites of histaminergic modulation of food intake, histamine H1-receptor antagonist was microinfused into the rat hypothalamus, the ventromedial hypothalamus (VMH), the lateral hypothalamus (LHA), the paraventricular nucleus (PVN), the dorsomedial hypothalamus (DMH), or the preoptic anterior hypothalamus (POAH), during the early light period. Feeding, but not drinking, was elicited in 100% of the rats (P less than 0.01) that were bilaterally microinfused with 26 nmol chlorpheniramine into the VMH. Unilateral infusion into the VMH did not affect food intake at doses of 26 or 52 nmol. Feeding was also induced by bilateral microinfusion into the PVN, but only the 52 nmol dose was effective. Bilateral infusions into the LHA, the DMH or the POAH did not affect ingestive behavior. Feeding induced by an H1-antagonist was completely abolished in all 7 rats tested when endogenous neuronal histamine was decreased by pretreatment with alpha-fluoromethylhistidine (100 mg/kg). The findings suggest that H1-receptors in the VMH and the PVN, but not in the LHA, the DMH or the POAH, may be involved in histaminergic suppression of food intake.

Animals↗

Presence of pancreatic-type phospholipase A2 mRNA in rat gastric mucosa and lung.

The content of mRNA for a pancreatic-type phospholipase A2 present in rat gastric mucosa was much greater than that in pancreas. In lung the mRNA for this pancreatic-type phospholipase A2 was also detected, but less than in pancreas. Nucleotide sequence analysis showed that these pancreatic-type phospholipase A2 cDNAs derived from rat gastric mucosa and lung were completely identical to that from rat pancreas (Ohara et al. (1986) J. Biochem. 99, 733-739). This demonstrates that the pancreatic-type phospholipase A2 present in gastric mucosa and lung does not originate from pancreas.

Animals↗

Effect of aspirin on urinary bladder carcinogenesis initiated with N-[4-(5-nitro-2-furyl)-2-thiazolyl]formamide in rats.

N-[4-(5-Nitro-2-furyl)-2-thiazolyl]formamide (FANFT), a potent urinary bladder carcinogen, is metabolically activated in vitro by a variety of enzyme systems including aerobic cooxidation by prostaglandin H synthase which is present in the rat bladder mucosa. In a previous experiment, aspirin coadministered with FANFT for 12 weeks inhibited FANFT-induced bladder carcinogenesis and enhanced forestomach carcinogenesis. To further evaluate the effects of aspirin on FANFT carcinogenesis, male F344 rats were fed either FANFT (0.2% of the diet) for 12 weeks (Group 4), aspirin (0.5% of the diet) simultaneously with FANFT for 12 weeks (Group 2), aspirin simultaneously with FANFT for 12 weeks and then subsequently to the end of the experiment (Group 1), or FANFT only followed by aspirin (Group 3). The incidence of bladder carcinoma was significantly higher when aspirin was fed after FANFT treatment (87%) compared to FANFT followed by control diet (48%) and was higher in rats given aspirin plus FANFT followed by aspirin (73%) compared to aspirin plus FANFT followed by control diet (47%). Aspirin alone given for 13 weeks (Group 6) or throughout the experiment (68 weeks) (Group 5) did not induce bladder cancer. However, in all groups administered aspirin long-term, renal papillary necrosis and renal pelvic hyperplasia and atypia were frequently observed. Only a single forestomach tumor was observed. In the present experiment, aspirin appeared to exhibit promoting activity for bladder carcinogenesis in the rat.

Animals↗

Attenuation of anorexia induced by heat or surgery during sustained administration of ginsenoside Rg1 into rat third ventricle.

Effects of ginsenoside Rg1 (Rg1), a major component of panax ginseng, on modulation of ingestive behavior were investigated. No direct effect was observed on food intake after 10 microliters infusion of 1.0, 2.0, 4.0 or 8.0 mM Rg1 into the rat third ventricle for 10 min. Continuous osmotic infusion of 4.0 mM Rg1 at a rate of 0.966 microliter/h into the third ventricle prevented feeding suppression caused by surgical procedure to implant an osmotic minipump. Continuous infusion of Rg1 attenuated anorexia, increased water intake, and decreased ambulation, that were produced by elevation of environmental temperature from 21 degrees C to 30 degrees C. Consequently, rats maintained body weight and rectal temperature unchanged. The results indicate that sustained central administration of Rg1 may relieve anorexia caused by implantation surgery or by a heated environment.

Animals↗

Structural evaluation of glucose analogues on feeding elicitation in rat.

The effects of 12-mumol doses of the glucose analogues glucosamine, 2-fluoroglucose, 2-chloroglucose, 2-deoxyglucose (which were modified at carbon 2 of the glucopyranose ring), 1-aminoglucose and 1-deoxyglucose (modified at carbon 1), on feeding behavior and plasma glucose, insulin, and glycerol were examined after infusion into the rat third cerebroventricle. Plasma glucose and glycerol levels were elevated by glucosamine or 1-aminoglucose. Plasma insulin levels were unchanged by these analogues. Feeding was induced in 62% to 87% of the rats tested after infusion of glucosamine, 2-fluoroglucose, 2-chloroglucose, 2-deoxyglucose, 1-aminoglucose, or 1-deoxyglucose (mean meal size in responding rats, 43.9, 25.8, 22.7, 16.0, 42.3, and 3.8 pellets, respectively). The order of potency to induce feeding was amino, halogen, and hydrogen groups. These data reinforced the concept that the potency of glucose analogues to induce feeding depends on substituents at carbon 1 and carbon 2 of the glucopyranose ring.

Animals↗

Characteristics of psychomotor performance and time cognition in moderately obese patients.

To clarify adherence of obese subjects to external food-relevant stimuli, we examined time cognition and psychomotor functioning of the obese under noneating conditions in the present study. Matched on the basis of age, sex, height, intelligence quotient and education, 13 moderately, but adult-onset obese (mean obesity index +/- SEM, 53.9 +/- 5.0% by Matsuki's method) and 13 normal weight subjects (-6.3 +/- 2.3%) were tested. Obese females were slower than normal weight control subjects in alternate tapping of two metal plates (p less than 0.01) and in transfer of a dowel (p less than 0.05). Normal subjects were slightly but significantly (p less than 0.05) more efficient in a self-cued traverse movement test, whereas the obese subjects were very much less efficient in the self-cued than in the externally-cued test. These findings suggest that evaluation of deficits of the obese must consider other factors in addition to simple physical slowness due to fattening. In time cognition tests, cognitive levels of the obese were more accurate when initiated by time cues than when they were self-cued (p less than 0.01). The results indicate that obese (even after adult-onset) may exhibit impairment in internal time cognition when deprived of external modulating time cues.

Adult↗

Impaired hypophagia induced by fecal anorexigenic substance in Zucker obese rats.

Influence of fecal anorexigenic substance (FS-T) on feeding by Zucker obese rats was compared to that by their lean littermates and Wistar King A rats. FS-T, which has been found to suppress food intake mainly by activation of glucoreceptor neurons in the ventromedial hypothalamus, was injected intraperitoneally in a dose of 7 U/kg at 1930 hr, immediately before the dark period. Potency of FS-T in feeding suppression was much less in the obese rats than in their lean littermates or the Wistar King A rats. Meal size of the obese rats was decreased after the injection, but meal duration was unaffected. The suppressive effect on the lean rats and the Wistar King A rats included decrease of both size and duration of the meal. These results suggest that chemosensitivity in the ventromedial hypothalamus of Zucker obese rats may be impaired, which may be one explanation of the obesity in Zucker obese rats.

Animals↗