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Biomedical subjects

T Katoh

Publications and source records attributed to T Katoh.

At least 379 records · Page 21Linked to original sources
PubMed1992

Portal hepatic venous shunt via an intrahepatic portal vein aneurysm.

A rare case of portal hepatic venous shunt (PHVS) via an intrahepatic portal vein aneurysm (PVA) is presented. A 66-year-old man was admitted for examination of a mass in the liver. Ultrasonography demonstrated a cystic lesion (15 mm in diameter) at the posterior superior segment of the right hepatic lobe which communicated with the right portal vein (RPV) and right hepatic vein (RHV). Superior mesenteric portography showed a biloculate aneurysm in RPV and PHVS. Color doppler ultrasonography indicated that flow in the tracts entered the aneurysmal cavity from RPV and drained into RHV.

Aged↗
PubMed1992

[Imaging diagnosis of the insulinoma--the clinical usefulness of intraductal ultrasonography of the pancreas and color Doppler sonography].

5 cases of small-sized insulinoma of the pancreas were studied to evaluate the ability of diagnostic imaging techniques to determine tumor location. Techniques used were extracorporeal ultrasonography, endoscopic ultrasonography (EUS), angiography, percutaneous transhepatic portal catheterization and CT. EUS was superior to the other modalities in diagnosing the location of insulinomas. We employed Color Doppler (CD) ultrasonography in one case and obtained color expression in the tumor and a pulsatile wave in the FFT analysis. Intraductal sonography of the pancreas (IDSP) was also performed in this case resulting peripheral echo-lucent, central echogenic mass. From these results, we expect that CD and IDSP will be useful in clinical application for diagnosing various tumors.

Adult↗
PubMed1992

Mitochondrial dysfunction in the non-obstructed lobe of rat liver after selective biliary obstruction.

In order to elucidate the function of non-obstructed hepatic lobe during partial cholestasis, we have examined the effects of selective biliary obstruction on the mitochondrial energy transducing system in rat liver. The non-ligated lobe became hypertrophic after ligation of the bile ducts that drained 90% of the liver, and there was no increase in the level of serum bilirubin, alkaline phosphatase activity, or bile acids. However, mitochondrial oxidative phosphorylation function, specific enzymic activities of the oxidative phosphorylation complexes, and the subunit contents of these complexes were markedly decreased in the non-obstructed lobe at 4 weeks after the 90% biliary obstruction. There was no increase in the specific content of mitochondrial DNA. The mitochondrial energy transducing system in the non-obstructed lobes is not enhanced, but is significantly impaired during prolonged selective biliary obstruction, despite normal serum biochemical data and hypertrophy of the non-ligated lobe. These results imply early release of obstruction of cholestatic lobe, e.g. by biliary drainage, would be beneficial for maintaining the mitochondrial function in the non-cholestatic lobe.

Animals↗
PubMed1992

[Left ventricular-right atrial communication with a residual ventricular septal defect: a case report of successful VSD patch closure with tricuspid valvuloplasty using folded patch].

A 18-year-old woman with combination of left ventricular right atrial communication (LV-RA communication) and residual ventricular septal defect (VSD) was presented. She underwent the radical operation of atrial septal defect, VSD and infundibular pulmonary stenosis at the age 11 years. Surgery was performed under the diagnosis of LV-RA communication and residual VSD. Two small defect were existed at the septal leaflet of the tricuspid valve, which communicated to left ventricle. The part of patch being used as closure of VSD at the previous operation, including perforated part of the septal leaflet was resected. A folded patch was used to reinforce the residual VSD and valvuloplasty was made using the remaining intact tricuspid tissues. Post-operative clinical course was uneventful. Shunt flow from LV to RA was not demonstrated in the postoperative left ventricular angiocardiography.

Adolescent↗
PubMed1992

[Successful treatment of disseminated breast cancer with combination therapy of 5'-deoxy-5'-fluorouridine (5'-DFUR), medroxyprogesterone acetate (MPA) and cyclophosphamide (CPA)].

A 54 year-old female patient with disseminated breast cancer refractory to various kinds of previous therapies was treated with a combination therapy of 5'-DFUR, MPA and CPA. Partial response (PR) was obtained both against pleural and liver metastases with complete disappearance (CR) of soft tissue lesions and was still being continued for the following 7 months. No serious side effects were observed except for a mild degree of diarrhea and moon face. The patient was enjoying a favorable quality of life. We confirmed that this combination regimen was effective as the second line treatment for disseminated breast cancer.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1992

[A successful treatment of emergent Cabrol's procedure for an acute aortic dissection (DeBakey type I)].

A 38-year-old male was admitted due to severe chest pain. Echocardiography and CT revealed an acute dissecting aneurysm. Cabrol's operation was performed immediately in order to prevent a rupture of the ascending aortic aneurysm and the dissection extending to the heart. Intraoperative trans-esophageal echocardiography was useful to get detailed informations, such as an extent of the dissection and a site of the entry. He was discharged from hospital on 53rd day and returned to society.

Adult↗
PubMed1992

[Corrected transposition of the great arteries with associated tricuspid valve incompetence--report of a case of successful tricuspid valve replacement].

A 36-year-old woman with corrected transposition (C-TGA) of great arteries with associated systemic atrioventricular valve (A-V valve) regurgitation was presented. Cineangiography revealed that the right sided ventricle was morphologic left ventricle, and left sided ventricle was morphologic right ventricle. In addition, severe systemic A-V valvular regurgitation (Sellers IV) was demonstrated. Under the diagnosis of C-TGA with associated A-V valvular regurgitation, left sided atrioventricular valve replacement was performed using 29 mm SJM valve. Left sided atrioventricular valve was tricuspid valve (TV). A part of the anterior tricuspid leaflet and two pieces of papillary muscle was resected. Postoperative course was uneventful. The pathological findings indicated that valvular tissue had myxomatous degeneration.

Adult↗
PubMed1992

[Linkage study of Machado-Joseph disease: genetic evidence for the locus different from SCA1].

Spinocerebellar ataxia 1 (SCA1) is the locus symbol of hereditary olivopontocerebellar atrophy, and it is mapped on the short arm of chromosome 6. D6S89 is the polymorphic DNA marker linked tightly to SCA1. In order to examine whether SCA1 and Machado-Joseph disease (MJD) loci are different from each other, we performed linkage study for D6S89 to MJD locus. A total of 20 pedigrees of MJD were analysed. Number of individuals consists of 211 members. Among them, 74 were affected. Consequently, 14 pedigrees showed negative lod score, and 6 showed weak positive lod scores at most of recombination fractions. As a whole, linkage between MJD locus and D6S89 was excluded at recombination fraction of 0.15. Our results further support the concept that MJD is not an allelic disorder but distinct genetic entity from SCA1.

Adult↗
PubMed1991

Cadmium causes increases of N-myc and multidrug-resistance gene mRNA in neuroblastoma cells.

Since cadmium exposure results in neuropathological alterations in central nervous system, we investigated the effects of cadmium on the gene expression of neuroblastoma (GOTO) cells. We observed an increase in mRNA levels of heat-shock protein (hsp) 70, hsp 90, hsp 32 and metallothionein after treatment of GOTO cells with cadmium, although the time courses of the changes of individual mRNA of the heat-shock proteins and metallothionein were somewhat different from each other. An accumulation of N-myc and multidrug-resistance gene (MDR1) mRNA was detected in the presence of cadmium. This is contrary to the previous report, in which an inverse correlation between the expression of MDR1 gene and N-myc oncogene in human neuroblastoma had been described. However, the increase of N-myc and MDR1 mRNA in the present study is not likely due to the loss of regulatory mechanism of these genes by cytotoxic effects of cadmium, because active protective mechanisms such as heat-shock proteins and metallothionein could be induced under these conditions.

Cadmium↗
PubMed1991

Automated determination of orotic acid, uracil and pseudouridine in urine by high-performance liquid chromatography with column switching.

A column-switching high-performance liquid chromatographic method, requiring no sample preparation apart from filtration, is described for quantification of urinary orotic acid, uracil and pseudouridine. The analyses were carried out using a reversed-phase octadecylsilane-bonded column for sample clean-up and a cation-exchange column for separation; 5-20 microliters samples of urine were directly analysed, and more than 100 samples could be analysed consecutively. Each sample required only 30 min. Detection limits of these compounds were 5 pmol. Creatinine-related urinary uracil excretion was lowest in the newborn period (17.3 +/- 14.4 mumol/g of creatinine). A patient with partial ornithine transcarbamylase deficiency and his mother usually excreted a high level of uracil during the period of normal orotic acid excretion and normal serum ammonia level.

Adolescent↗
PubMed1991

Induction of glutathione-S-transferase and heat-shock proteins in rat liver after ethylene oxide exposure.

Defense mechanisms in rat liver against depletion of glutathione (GSH) and cellular injuries induced by ethylene oxide (EO) were studied. Rats were exposed to EO under either high dose (1300 ppm for 4 hr, once) or low dose (500 ppm for 6 hr, three times a week for 6 weeks) conditions. The hepatic content of GSH decreased dramatically after EO treatment, probably due to detoxication of EO. After the high dose treatment the hepatic GSH content fell by 90% of the control values but recovered within 10 to 15 hr. EO reacts directly with a variety of cellular macromolecules but all rats survived the exposure. Since the metabolites of EO are ethylene glycol and GSH-conjugates, the enzymatic activities of epoxide hydrolase and glutathione-S-transferase (GST) were determined. Only GST activity was found to occur after low dose chronic exposure. The defense mechanism at mRNA level was investigated using probes for GST and several heat-shock proteins (hsps). Enhanced accumulation of GST mRNA was detectable during the recovery period of rats after both high and low dose exposure to EO. Interestingly, both hsp32 (less than 40-fold) and hsp90 (less than 3-fold) mRNA increased after high dose exposure but the mRNA level of one of the major heat-shock proteins, hsp70, did not change under these conditions. Diethylmaleate, which is known to be a GSH depleter in liver, induced hsp32 mRNA only in rat liver, while hsp70 and hsp90 mRNA levels did not change when GSH was depleted. These results suggest that individual heat-shock proteins are induced in different ways under unphysiological conditions such as EO exposure.

Animals↗
PubMed1991

Autoactivation of calmodulin-dependent protein kinase II by autophosphorylation.

Autophosphorylation of calmodulin (CaM)-dependent protein kinase II (CaM-kinase II) under limiting conditions (2 microM ATP) decreased progressively with increasing concentrations of a substrate, Pro-Leu-Ala-Arg-Thr-Leu-Ser-Val-Ala-Gly-Leu-Pro-Gly-Lys-Lys (syntide-2), suggesting a competition between the substrate and the autophosphorylation site(s) of the enzyme. The rate and extent of the generation of Ca2+/CaM-independent activity of the enzyme by autophosphorylation were also decreased by the presence of syntide-2. The syntide-2 phosphorylation in the presence of Ca2+/CaM under the limiting conditions reached a steady state, after a lag, when the Ca2+/CaM-independent activity reached a plateau. A linear relationship was observed between the activities in the presence and absence of Ca2+/CaM of the enzyme which had undergone various degrees of autophosphorylation, and the extrapolation of activity in the absence of Ca2+/CaM to zero gave 15-20% of the maximum activity. The steady-state rate of syntide-2 phosphorylation in the presence of Ca2+/CaM by the enzyme that had not undergone prior autophosphorylation was decreased by high concentrations of syntide-2 which suppressed autophosphorylation as well as the generation of Ca2+/CaM-independent activity. These results suggest that although the nonautophosphorylated enzyme possesses a basal low level of Ca2+/CaM-dependent activity, autophosphorylation is required for full activation.

Calcium↗
PubMed1991

Calmodulin-dependent protein kinase II. Kinetic studies on the interaction with substrates and calmodulin.

The kinetic reaction mechanism of calmodulin (CaM)-dependent protein kinase II (CaM-kinase II), including the regulatory mechanism by CaM, was studied by using microtubule-associated protein 2 (MAP2) as substrate under steady-state conditions. The detailed kinetic analyses of the phosphorylation of MAP2 and its inhibitions by the reaction products and by an ATP analogue, 5'-adenylylimidodiphosphate, revealed the rapid-equilibrium random mechanism. In the absence of Ca2+, CaM-kinase II was inactivated by incubation with ATP. The inactivation rate was dependent on the concentrations of ATP and MAP2, suggesting that these substrates can bind to the enzyme even in the absence of Ca2+/CaM. The activation of the enzyme by CaM reached the maximum when about 10 mol of CaM bound to 1 mol of CaM-kinase II, indicating the stoichiometry of the binding of one CaM to one subunit of the enzyme. The enzyme activity as a function of the concentration of CaM showed a sigmoidal curve. The concentration of CaM required for the half-maximal activation was dependent on the concentration of ATP at a fixed concentration of MAP2, although the Hill coefficient was unaffected by the concentration of ATP. A possible reaction mechanism of CaM-kinase II, including the phosphorylation of MAP2 by the enzyme and the binding of CaM to the enzyme, is discussed.

Adenosine Triphosphate↗
PubMed1991

Tinea corporis due to Microsporum canis from an asymptomatic dog.

The patient was a 19-year-old female student who purchased a puppy from a pet shop four weeks earlier. At the time of her first examination, an annular edematous erythema with adherent scales and vesicles surrounding its margin was seen on the left forearm. On direct examination of the vesicles, fungal elements were detected, and Microsporum canis was isolated. The puppy was a Pomeranian and was kept in the house at all times. No clinical lesions were seen on the puppy, and the Wood's lamp test was negative. However, M. canis was isolated from the animal by the hairbrush method. Symptoms disappeared after the patient was treated topically with terbinafine cream for three weeks. Although the dog received no treatment whatsoever, there was no evidence of the disease on the pet. Results of the hairbrush method performed on the pet two and three weeks later were negative, but, at five weeks, it was again positive. Human infection with M. canis from an asymptomatic dog was demonstrated in this case. Attention should be paid to preventing infections from animals without lesions.

Adult↗