Biomedical subjects

S Tsuchida

Publications and source records attributed to S Tsuchida.

At least 109 records · Page 6Linked to original sources

PubMed1994

[The protective effect and problem of retrograde cerebral perfusion].

In order to study the protective effect and problem of retrograde perfusion (RCP), cerebral hemodynamics and cerebral metabolism were evaluated in fourteen pigs weighing 25-30 kg. Intracranial pressure, carotid arterial flow and pressure, and internal jugular venous pressure as cerebral hemodynamics; pyruvate, lactate, and oxygen consumption as cerebral metabolism; and brain temperature were measured. The animal was cooled to electrical cerebral silence on electroencephalogram under cardiopulmonary bypass. Then, animals were divided into three groups: group I (n = 4); circulatory arrest; group II (n = 3); RCP through superior vena cava (SVC); group III (n = 7); RCP through bilateral internal jugular vein (IJV). Retrograde perfusion flow was regulated to maintain the SVC pressure or IJV pressure of 30 mmHg, for 90 minutes. The variations in brain temperature were least in group III. As perfusion flow increased, intracranial pressure, and inferior vena cava (IVC) pressure increased. But, cerebral perfusion pressure, which was calculated from the difference of intracranial arteriovenous pressure, did not increase and, SVC pressure and returned blood flow through the aorta did not increase in group III. In group II, there was no significant relation between pump flow, SVC pressure, and intracranial pressure, but SVC pressure had a positive correlation with the pressure gradient of SVC-IJV. The uptake of cerebral lactate, cerebral pyruvate, and lactate-pyruvate ratio, and cerebral oxygen consumption were superior in group III than other groups. In conclusion, RCP through IJV was advantageous to maintain hypothermia and aerobic metabolism of the brain during systemic hypothermic circulatory arrest.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1994

Morphological characterization of glomerular endothelial cells cultured on a basement membrane matrix.

We characterized the morphological expression of glomerular endothelial cells (GEC) cultured on a basement membrane matrix, Matrigel. GEC cultured on this matrix formed abundant networks of branching and anastomosing cords of cells, and formed capillary-like structures with a lumen and interdigitating junctional processes. In contrast, GEC cultured on fibronectin-coated dishes had elongated spindle shapes without any interdigitating junctional processes. These findings suggest that the culture system with Matrigel is useful for inducing and maintaining characteristics close to in vivo GEC.

Animals↗

PubMed1993

Expression of glutathione S-transferase-pi in human squamous cell carcinomas of the pharynx and larynx. Loss after radiation therapy.

BACKGROUND AND METHODS: The expression of the placental form of glutathione S-transferase (GST-pi) in human squamous cell carcinomas of the pharynx and larynx was investigated immunohistochemically before and after radiation therapy. RESULTS: Before the treatment, 47 of 71 carcinoma specimens (66.2%) demonstrated positive reactions, GST-pi being diffusely stained throughout the tumor lesions. Positive rates for moderately and well differentiated carcinomas were 69.7% and 88.0%, respectively, with both of these values being significantly higher than that for poorly differentiated carcinomas (15.4%, P < 0.01). Thus, GST-pi expression seems to be related to the degree of differentiation. Although several tumors exhibiting GST-pi staining did not respond to radiation therapy, most cases responded positively and no relation was apparent in the 41 cases of squamous cell carcinoma studied between response to radiation therapy and previous GST-pi staining. After irradiation of 1000 to 7000 cGy, however, most carcinoma specimens exhibited negative GST-pi staining, regardless of response to radiation therapy. CONCLUSIONS: The results suggest that although GST-pi expression is not directly involved in determining sensitivity to radiation, GST-pi expression can be influenced by exogenous agents. The loss or decrease of GST-pi after irradiation is in clear contrast to the enhanced expression observed in many cancer cell lines resistant to chemotherapy.

Adolescent↗

PubMed1993

Rapid detection of mitochondrial DNA polymorphism by photoactivatable biotin.

A new method for the detection of mitochondrial (mt)DNA polymorphism by agarose gel electrophoresis is presented. In this method, after mtDNA digestions with endonucleases, the mtDNA fragments are labeled directly with photoactivatable biotin in the digestion buffer, separated by agarose gel electrophoresis, transferred to a nylon membrane and detected enzymatically using streptavidin-alkaline phosphatase, Nitroblue tetrazolium (NBT) and 5-bromo-4-chloro-3-indolylphosphate (BCIP). This method is useful for the detection of mtDNA digestion patterns by agarose gel electrophoresis, especially when enough purified mtDNA cannot be obtained and the radioisotope cannot be handled because of several restrictions.

Alkaline Phosphatase↗

PubMed1993

Identification of cysteine residues involved in disulfide formation in the inactivation of glutathione transferase P-form by hydrogen peroxide.

We previously reported that rat glutathione transferase P-form (GST-P) is inactivated by hydrogen peroxide (H2O2). This involves formation of intra- or intersubunit disulfides, at least three extra bands with molecular masses of 21.5, 18, and 37 kDa being exhibited in addition to the native subunit band of 23.5 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) under nonreducing conditions. In the present study, GST-P mutants whose cysteine residues were independently substituted with alanine (C14A, C47A, C101A, and C169A) by site-directed mutagenesis were used to identify the cysteine residues responsible for the disulfide bond formation. C14A and C169A were much more inactivated than native GST-P by 1 mM H2O2, whereas C47A and, especially, C101A appeared insensitive to H2O2. On SDS-PAGE, the 21.5-kDa band was not detected in either C47A or C101A. Hydrogen peroxide treatment of mouse GST II, highly homologous to rat GST-P but possessing glycine instead of cysteine at the 101st residue, did not result in generation of the 21.5-kDa band and was also associated with less inactivation. This band was therefore considered to be due to an intrasubunit disulfide bond between Cys-47 and Cys-101. The 37-kDa band was suggested to be due to the formation of intersubunit disulfide bonds between Cys-47 residues in different subunits. Thus the Cys-47 residue together with Cys-101 may be located in an important region for GSH binding, disulfide bond formation between these residues resulting in steric hindrance.

Animals↗

PubMed1993

CT and MRI of haemorrhage into intracranial neuromas.

Six patients with haemorrhage into intracranial neuromas were studied by computed tomography (CT) and magnetic resonance imaging (MRI) at 0.5 T with spin-echo pulse sequences. The nature of the tumour and the presence of a haematoma were confirmed by surgery and microscopic examination in all cases. Four neuromas arose from the acoustic nerves and two from the trigeminal. Four of the six patients suffered from sudden onset or rapid worsening of symptoms including headache, vertigo and/or hemifacial motor and sensory disturbances. CT in the acute stage revealed a hyperdense area or a fluid-fluid level (FFL). The hyperdense area disappeared on CT repeated in the chronic stage. On MRI in subacute and chronic stages the haemorrhage showed hyperintensity on both T1 and T2 weighting in five cases examined between 16 and 46 days after the onset, and isointensity on T1 weighting and an FFL on T2 weighting in one case examined 12 days after the onset of symptoms. A well-defined low intensity rim indicating prior haemorrhage was observed on T2-weighted images in three cases. MRI was more effective than CT in detecting haemorrhage into the tumours and in staging it.

Adult↗

PubMed1993

Ultrasonographic evaluation of bladder volume in children.

Although ultrasound has been recently used to estimate bladder volume, several different formulae are used. We analysed the accuracy of ultrasound evaluation of bladder volume with an ultrasound scanner equipped with a videocassette recorder. We determined three dimensions of the bladder, i.e. depth (D), height (H) and width (W) by reviewing videotapes in 53 children. D x H x W (DHW) showed a good linear relationship with actual bladder volume (r = 0.96). Estimation of bladder volume by the regression equation gave errors of 12.5 +/- 8.6% (mean +/- SD) with errors above 25% in only 6% of children. Estimation of the volume by simply multiplying DHW by a correction factor of 0.80 gave a greater error of 18.9 +/- 14.0% (P < 0.001) with errors above 25% in 24% of children. Thus, the use of the formula volume (ml) = DHW (cm3) x 0.68+4 was sufficiently accurate in the ultrasound estimation of bladder volume in children.

Adolescent↗

PubMed1993

Evaluation of MRI score in the differentiation between glioblastoma multiforme and metastatic adenocarcinoma of the brain.

The authors statistically analyzed the MR configurations of 14 glioblastoma multiformes (GBMs) and 15 metastatic adenocarcinomas (MACs) of the brain in order to distinguish these two histological types on MR images. MR configurations were classified and scored upon the 9 criteria of heterogeneity, cyst or necrosis, haemorrhage, crossing of the midline by the tumour, oedema or mass effect, border definition, flow void sign, degree and heterogeneity after contrast enhancement. The mean value of GBMs was 1.47 +/- 0.22, and that of MACs was 0.91 +/- 0.37 (P < 0.001). GBMs had significantly higher values in five out of the nine criteria: border definition, heterogeneity, crossing of the midline of the tumour, flow void sign, and degree of the contrast enhancement (P < 0.001-0.05). Border definition was the best criterion for distinguishing two histological types. Six cases of MACs displayed hypo-intense lesions on T2 weighted images in contrast to GBMs which showed hyperintense lesions in all cases. In 4 out of the 6 MACs which were shown as hyperintensities on T2 weighted images, a hypo-intense peritumoural rim was noticed between the tumour parenchyma and the surrounding oedema. These data strongly suggest that GBMs and MACs can be distinguished on MR image by using MRI score.

Adenocarcinoma↗

PubMed1993

Antihypertensive effect of a newly synthesized endothelin antagonist, BQ-123, in a genetic hypertensive model.

A newly synthesized ET(A)-selective antagonist, BQ-123, was examined with respect to its anti-endothelin(ET) action in vitro and in vivo and its effect on blood pressure in Wistar Kyoto rats (WKY), spontaneously hypertensive rats (SHR) and stroke-prone spontaneously hypertensive rats (SHRSP). In isolated porcine coronary arteries, BQ-123 (0.07 microM to 6.0 microM) shifted the concentration-response curve for ET-1 to the right without affecting the maximal response of ET-1, its pA2 value being 7.35. Intravenous infusion of BQ-123 at a rate of 1.2 and 30 mg/kg/hr produced a significant decrease in blood pressure in 20- to 29-week-old SHRSP, but did not alter blood pressure in 13- to 16-week-old WKY or in 18- to 19-week-old and 40-week-old SHR. The hypotensive effect of BQ-123 depended on the pretreatment blood pressure level. These results suggest that ET-1 is involved in part in the maintenance of high blood pressure in malignant hypertension, as exemplified by SHRSP.

Amino Acid Sequence↗

PubMed1993

A case of pontine lacunar infarction with ulcerative colitis.

We present the case of a young man who experienced a sudden onset of pure motor hemiplegia in association with ulcerative colitis. Based on a review of earlier reports, ulcerative colitis was suspected to be the background disease leading to cerebral infarction. A cerebral infarction of the lacunar type in the right ventromedial aspect of the upper pons was seen on magnetic resonance images. These images detected small lesions in the brain stem, and were used to follow-up their transitions.

Adolescent↗

PubMed1993

Lack of peroxisomal enzyme inducibility in rat hepatic preneoplastic lesions induced by mutagenic carcinogens: contrasted expression of glutathione S-transferase P form and enoyl CoA hydratase.

While glutathione S-transferase P form (GST-P), a reliable marker for preneoplastic lesions induced by mutagenic hepatocarcinogens, is generally not expressed in rat liver foci, hyperplastic nodules and hepatomas induced by peroxisome proliferators (PPs), such lesions can be detected due to their peroxisomal enzyme-negative nature. For comparative purposes we examined the inducibility of enoyl CoA hydratase (ECH), a key peroxisomal enzyme, in rat hepatic preneoplastic lesions induced by mutagenic carcinogens. Clofibrate (CF) was therefore administered for 2 or 4 weeks following performance of the Solt-Farber protocol using diethylnitrosamine and 2-acetylaminofluorene. Immunohistochemical examination revealed no or only very weak expression of ECH within the induced foci in clear contrast to the strong staining of surrounding parenchyma. ECH expression was thus diametrically opposed to that of GST-P which was found only in foci. Although ECH was completely lacking in GST-P-strongly positive foci, it was expressed in GST-P-negative hepatocytes inside some foci otherwise positive for GST-P. CF administration resulted in a significant decrease in the numbers and areas of foci exhibiting strongly positive or positive GST-P staining; this being reflected in a lowering of GST-P protein levels. Furthermore, in primary cultured rat hepatocytes, clofibric acid as well as dexamethasone suppressed the expression of both GST-P and the oncogene, c-jun. These results taken together suggest that possible interaction of the PP receptor with JUN might be involved in loss of ECH expression in GST-P-strongly positive foci.

Animals↗

PubMed1993

Urinary growth hormone excretion in preterm neonates.

We measured urinary growth hormone (U-GH), beta 2-microglobulin (U-B2) and serum growth hormone (S-GH) in preterm neonates on days 1, 4, 7, 14 and 28 of age. U-GH as well as U-B2 were high, particularly in the more premature and sick neonates with respiratory failure requiring mechanical ventilation. U-GH showed significant positive correlations with U-B2 throughout the study but with S-GH only on day 7. Therefore, we conclude that in preterm neonates, U-GH mainly reflects the degree of renal proximal tubular function, which is determined by the degree of renal maturation of the subject and of tubular injury due to disease states such as respiratory failure.

Aging↗

PubMed1993

Effect on urapidil on benign prostatic hypertrophy: a multicenter, double-blind study.

In a prospective multicentric double-blind trial, urapidil, an alpha 1-adrenergic antagonist, was investigated for its efficacy in benign prostatic hypertrophy (BPH). After 1 week of baseline on placebo, 214 patients with BPH were randomly assigned to 4 groups; group P was given placebo, group L, 15 mg of urapidil b.i.d. for 3 weeks, group M, 15 mg b.i.d. for 1 week followed by 30 mg b.i.d. for 2 weeks, and group H, 15 mg b.i.d. for 1 week followed by 45 mg b.i.d. for 2 weeks. In all groups, day and night urinary frequency improved significantly (p < 0.01 or p < 0.05) compared to baseline, but the differences were not significant between groups. The residual urine rate was significantly (p < 0.05 vs. group P) decreased in group H. Average and maximum flow rate improved significantly (p < 0.01 or p < 0.05) in group M and group H, but intergroup differences were not noted. Overall impression evaluated by investigators improved significantly (p < 0.01 vs. group P) in group M and group H. More patients in group H (7/55) and group M (4/51) had side effects than in group P (2/54). None of them were severe. In summary, a daily dosage of 60 mg urapidil proved to be the most beneficial in the treatment of patients with BPH.

Adrenergic alpha-Antagonists↗

PubMed1993

Astrocytic gliomas: MRI and pathological grade.

The relationship between MR configuration and pathological grade was studied in 41 histologically verified supratentorial astrocytic gliomas with a 0.5T superconductive MR system. The gliomas included 13 low-grade astrocytomas (LGAs), 14 anaplastic astrocytomas (AAs) and 14 glioblastoma multiformes (GBMs). MRI configurations were classified into nine criteria which were scored and statistically analyzed. The mean values of LGAs, AAs and GBMs were 0.45 +/- 0.31, 1.18 +/- 0.20 and 1.47 +/- 0.22. In each grade, MRI score increased as pathological grades increased (p < 0.01-0.001). LGAs had significantly lower values than AAs in five of the nine criteria (55.6%); heterogeneity, cyst or necrosis, edema or mass effect, border definition, and the degree of contrast enhancement, and lower values than GBMs in eight criteria (88.9%) except for hemorrhage. Three criteria (33.3%), heterogeneity, cyst or necrosis, and flow void sign were significantly higher in GBMs than AAs. The four variables, heterogeneity, cyst or necrosis, edema or mass effect and border definition, proved to be important factors related to the pathological grade in a multiple regression analysis.

Adolescent↗

PubMed1993

Loss of ICG uptake in the process of rat hepatocarcinogenesis correlates to the disappearance of glutathione-S-transferase alpha subunit.

Reduced indocyanine green (ICG) uptake is one of the functional changes of human hepatocellular carcinoma (HCC). To clarify the mechanisms of loss of ICG uptake, and determine which subunit of glutathione-S-transferase (GST), alpha or pi, plays a role in ICG transport in hepatocytes, an experimental HCC model was developed that used nodules induced by 2-acetylamino-fluorene (2-AAF) administration. Many of the ICG stained nodules, which consisted of benign and borderline lesions, were GST-alpha positive. However, the percentage of GST-alpha positive cells tended to decrease according to the disappearance of ICG staining in the process of hepatocarcinogenesis. HCCs unstained by ICG were also GST-alpha negative. GST-pi, not detected in normal rat hepatocytes, appeared in an earlier stage of hepatocarcinogenesis before the disappearance of GST-alpha, and was not observed in HCCs. No significant relationship between ICG staining and GST-pi was recognized. These results suggest that GST-alpha synthesis is disturbed in the process of hepatocarcinogenesis and results in loss of ICG uptake in HCCs, and also indicate that GST-pi may be useful for early diagnosis of preneoplastic hepatocytes showing no roles in ICG transport.

Animals↗

PubMed1993

Autosomal dominant polycystic kidney disease in a child diagnosed by ultrasonography.

A 10-year-old boy with a chief complaint of nocturnal enuresis was identified as having three cysts in each kidney on ultrasonographic examination. These findings together with a positive family history for renal failure prompted us to examine his father ultrasonographically on the same day, resulting in the identification of multiple large cysts in both kidneys. These observations supported a diagnosis of autosomal dominant polycystic kidney disease. Enhanced X-ray CT demonstrated more sensitively the presence of renal cysts in the boy. He had a normal urinary concentrating ability and no other abnormalities except for mild hypertension, which was successfully treated only by salt restriction. Ultrasonography thus appears to be a valuable tool for diagnosing polycystic kidney diseases.

Child↗

PubMed1993

[Nutritional improvement after operation of valvular heart diseases with protein-calorie malnutrition].

We evaluated the nutritional states before and after operation in patients with severe valvular heart disease characterized by malnutrition. The patient population consisted of 6 females, age range between 42 and 60, average 52.2 years old. The valve lesions were mitral stenosis in 2, combined aortic and mitral valve diseases in additional 4 patients, and moderate to severe tricuspid regurgitation was noted in 5 of these 6 patients. All 6 patients underwent a successful mitral (c/s aortic) valve replacement, and 5 of 6 tricuspid annuloplasty. The ideal body weight increased significantly from 77.9 +/- 3.4% preoperatively to 84.6 +/- 3.9% postoperatively (p < 0.01). Late postoperative cardiac catheterization revealed an improvement of mixed oxygen saturation (61.3 +/- 3.8%, preoperatively vs 67.3 +/- 5.6%, postoperatively; p < 0.01). The postoperative serum prealbumin, retinol binding protein and K value in intravenous glucose tolerance test increased significantly (p < 0.05) compared to those before operation. In conclusion, our data suggested that corrective surgery would have a good effect on nutritional improvement of the protein-calorie malnutrition caused by valvular heart diseases.

Adult↗

PubMed1992

The changes in the activity of pudendal motoneurons in relation to reflex micturition evoked in decerebrate cats.

Reflex micturition was evoked in both non-immobilized (n = 5) and immobilized (n = 5) decerebrate cats by filling the bladder with physiological saline. Intracellular recordings were made from pudendal motoneurons (PU-MNs; n = 14) throughout the periods of before, during and after reflex micturition. The changes in the activity of PU-MNs were correlated with those in the intravesical pressure. Our results support the proposition that coordination of the sphincters and the detrusors is established by a gating mechanism, which is activated by the supraspinal source such as the pontine micturition center.

Animals↗