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Biomedical subjects

T Katoh

Publications and source records attributed to T Katoh.

At least 523 records · Page 29Linked to original sources
PubMed1985

[A case of polymorphous adenocarcinoma in the right parotid gland].

The nature of adenocarcinomas of parotid gland origin seems to be still unclear because of the rarity of this lesion. A 65-year-old man with a "polymorphous adenocarcinoma" of the parotid gland is presented. This tumor is characterized by a marked diversity in the histologic manifestations, presenting dominantly solid, tubular, pseudoadenoid cystic sarcomatoid patterns. The tumor cells showed distinctive signs of high grade malignancy such as the occurrence of mitotic figures and involvements of lymphatic vessels and/or blood vessels. "Polymorphous adenocarcinoma" is a histologically distinctive neoplasm unlike other adenocarcinomas of parotid gland origin.

Adenocarcinoma↗
PubMed1985

Neonatal type of argininosuccinate synthetase deficiency. Report of two cases with autopsy findings.

Two autopsy cases of neonatal argininosuccinate synthetase (ASS) deficiency demonstrating the particular histological changes of the liver are presented. Case 1 was a female infant with elevated blood ammonia and citrulline. The patient died of sepsis at nineteen days after birth. Autopsy revealed hematomas in bilateral cerebral hemispheres and a yellow liver parenchyma. Histologically, the cerebrum showed diffuse astrogliosis with Alzheimer type II cell and swollen cytoplasm. Status spongiosus and gliosis were observed in the subthalamic and pontine nuclei. The liver demonstrated fatty degeneration and wide portal space with bile duct proliferation and inflammatory cell infiltration. The ASS activities in the liver and the kidneys were not detected. Case 2 was a female infant who died of respiratory distress twenty-four days after birth. Autopsy revealed hematomas in the bilateral cerebral ventricles and a liver with yellow parenchyma. Histologically, there was destruction of arrangement in the cerebrum and cerebellum together with marked decrease of nerve cells with gliosis and phagocytosis. The liver showed mild fatty degeneration and wide portal space accompanied by bile duct proliferation and inflammatory cell infiltration. The ASS activities in the liver and kidneys were not detected.

Amino Acid Metabolism, Inborn Errors↗
PubMed1984

Malignant parotid gland tumors and facial nerve paralysis.

During the last three decades, 586 cases of parotid gland tumor have been extirpated in our clinic. The tumors were malignant in 170 cases and, of these, facial nerve paralysis was observed at first examination in 59 patients. This paper deals with the retrospective study of these cases and is chiefly concerned with the histological types and facial nerve paralysis.

Facial Paralysis↗
PubMed1984

Electrophysiologic and hemodynamic effects of propafenone, a new antiarrhythmic agent, on the anesthetized, closed-chest dog: comparative study with lidocaine.

The relative hemodynamic and electrophysiologic effects of a new antiarrhythmic drug, propafenone, and lidocaine were evaluated in eight closed-chest, anesthetized dogs. Propafenone (4 mg/kg intravenously) significantly (p less than 0.05) lowered aortic and pulmonary systolic pressures and caused a rise in heart rate (p less than 0.05). Cardiac output decreased from 4.5 +/- 1 to 3.8 +/- 0.7 L/min (p less than 0.05) during atrial pacing at 400 msec cycle length. Propafenone had no effect on pulmonary and aortic diastolic pressures. Lidocaine (5 mg/kg intravenously) caused a significant (p less than 0.05) decrease in aortic systolic pressure and a rise in heart rate. Lidocaine had no significant effect on the other measured hemodynamic parameters. Propafenone, unlike lidocaine, significantly (p less than 0.05) increased atrioventricular nodal functional refractory period and right ventricular endocardial (apex) cathodal (0.5 +/- 0.1 mA to 1.9 +/- 0.3 mA) and bipolar (1.4 +/- 0.3 to 2.2 +/- 0.4 mA) diastolic excitability threshold. Propafenone, unlike lidocaine, also caused a significant (p = 0.05) intraatrial conduction delay; however, neither drug caused conduction slowing in the His-Purkinje system. Both drugs had no effect on sinus nodal recovery time and on the effective refractory period of the right ventricular endocardium (apex). Mean plasma propafenone levels during hemodynamic and electrophysiologic measurement ranged between 3.2 +/- 1.8 micrograms/ml and 1.7 +/- 1.1 micrograms/ml. All of the propafenone-induced effects were reversible within 90 minutes. We conclude that propafenone differs from lidocaine in its atrial, AV nodal, and ventricular electrophysiologic properties, and thus these may explain propafenone's greater efficacy over lidocaine against both certain atrial and ventricular arrhythmias.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia↗
PubMed1984

The relationship between ventricular arrhythmias and ischemia-induced conduction delay in closed-chest animals within 24 hours of myocardial infarction.

To investigate the myocardial conduction characteristics of premature impulses during the first 24 hours following coronary ligation and its relationship to late infarction ventricular arrhythmias, transmural electrodes were positioned in the normal and ischemic myocardium in nine dogs. Cardiac conduction in ischemic myocardium was delayed 15 minutes post coronary occlusion both in the epicardium and endocardium, both in the anterograde (base to apex) and retrograde (apex to base) direction, and was maintained at the same level throughout the experiment. Conduction across the border of ischemic myocardium from ischemic to the normal segment was also delayed, especially in the endocardium. Spontaneous ventricular arrhythmias recorded on Holter tapes showed significant increase in the number of premature ventricular complexes and ventricular tachyarrhythmias 9 hours after infarction. Thus our findings suggest that spontaneous arrhythmias occurring in the late phase of acute myocardial infarction (AMI) are independent of the ischemia-induced conduction delay and an alternate mechanism such as abnormal automaticity may be responsible for late ventricular arrhythmias.

Animals↗
PubMed1984

Binding of F-actin to a region between SH1 and SH2 groups of myosin subfragment-1 which may determine the high affinity of acto-subfragment-1 complex at rigor.

Covalent cross-linking reaction between SH1 and SH2 groups in myosin subfragment-1 (S-1) by N,N'-p-phenylenedimaleimide (pPDM) was followed by the degree of inactivation of NH4+-EDTA ATPase activity. The rate of the cross-linking reaction decreased to less than a 20th in the presence of F-actin. The inhibitory effect of F-actin was not observed in the presence of MgATP. Binding of F-actin to S-1 was measured using ultracentrifugation. S-1 whose SH1 and SH2 were covalently cross-linked by pPDM or 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB) did not bind F-actin. After the DTNB-cross-linked S-1 is reduced by dithiothreitol, the ability to bind F-actin is recovered. These results suggest that S-1 has a binding site for F-actin in the region between SH1 and SH2. This site appears to determine the high affinity of acto-S-1 complex at the rigor while decreasing the affinity more than 10(2) times in the presence of MgATP.

Actins↗
PubMed1984

Interaction between myosin and F-actin. Correlation with actin-binding sites on subfragment-1.

F-Actin bindings to subfragment-1 (S-1) and S-1 after limited proteolysis by trypsin (S-1t) were studied in the absence and presence of ATP by means of ultracentrifugation. No significant difference in the affinities for F-actin was observed between S-1 and S-1t in the absence of ATP. In contrast, the affinity for F-actin in the presence of ATP was decreased about 50 times by the limited proteolysis of the S-1 heavy chain. The S-1 whose SH1 and SH2 groups were cross-linked by N,N'-p-phenylenedimaleimide bound F-actin weakly. The affinity for F-actin was similar to that of unmodified S-1 in the presence of ATP and was also decreased markedly by limited proteolysis of the cross-linked S-1. Reciprocals of the dissociation constant of acto-S-1 complex decreased markedly with increase of ionic strength in the presence of ATP, but decreased only slightly at the rigor state. All these results are consistent with our proposal that S-1 has two different actin binding sites, as reported previously (Katoh, T., Imae, S., & Morita, F. (1984) J. Biochem. 95, 447-454). The mechanism of activation of S-1 ATPase by F-actin is discussed.

Actins↗
PubMed1984

CCU network as primary care of acute myocardial infarction.

The early pre-hospital care of patients with acute myocardial infarction (AMI) is critical because of high mortality during acute phase of AMI. A CCU network has been established by the Metropolitan Tokyo CCU Communication Society and the help of the Ambulance Units through the Control Room of the Tokyo Fire Department, performing ECG telephone line transmission and telephone consultation. Out of 1439 patients admitted by means of CCU network during the 8-month period (Jan. 1982-Aug. 1982), 505 (30.3 percent) had AMI as a final cardiac diagnosis. Many patients were admitted directly to the CCU by ambulance from the place where the patient was located, with the shortest overall time of 7 hours 25 minutes. Fifty-three percent of patients with AMI were admitted within 6 hours after the onset of symptoms. The mean patients' decision time was 9 hours 48 minutes, which comprised one half of the overall period as well as physician delay of 6 hours 36 minutes on the average. Thus, community oriented educational programs to more fully inform the population and individual hospital evaluations to hospitalize patients with chest discomfort are needed in order to shorten the decision time and physician delay expediting the care of these patients.

Adolescent↗
PubMed1984

[Laboratory and clinical studies of cefotiam in digestive diseases].

Experimental and clinical studies on cefotiam (CTM), a new synthetic cephalosporin, were performed in digestive diseases. Among the 7 cases of 'cholelithiasis and cholangitis', 6 cases (86%) showed better response than "effective". Among the 9 cases of infections except 'cholelithiasis and cholangitis' which had no connection with cancers, 6 cases (67%) showed better response than "effective". Among the 15 cases of 'infections following advanced cancers', 7 cases (47%) showed better response than "effective". This inferior result was due to the relation to factors coming from cancers. CTM was effective in not only infections of the aged but that which resisted antibiotics of penicillins and the other cephems. Sensitivity of E. coli, Klebsiella and S. aureus was made a comparative study of by MIC and disc test. It was found as a result that CTM had the equal or superior antimicrobial activity to other antibiotics of cephems, penicillins and aminoglycosides.

Adult↗
PubMed1984

Specificity of murine monoclonal antibodies induced by a choriocarcinoma cell-line (BEWO).

The specificity of two murine monoclonal antibodies (BW 252/104, IgG3 and BW 241/10, IgM) which recognize two different antigens is described. BW 252/104 recognizes an epitope detectable on all human cell lines and most of the human tissues tested. On account of this reactivity this antibody could be said to possess a "pan human" specificity. BW 241/10 is mainly reactive with human granulocytes but shows some binding to certain solid tissues (breast, stomach). Because of its lack of reactivity to human lymphocytes and monocytes this antibody could be of interest in the detection of human granulocytes.

Animals↗
PubMed1984

[Size reduction of a nonfunctioning pituitary adenoma after bromocriptine therapy: case report].

Bromocriptine therapy may cause regression of prolactinomas and GH producing adenomas, but there is only few reports about the effect of bromocriptine against nonfunctioning pituitary adenomas and there is no reports about its histopathological changes. We report a nonfunctioning pituitary adenoma, which remarkably regressed during and following bromocriptine therapy. A 47-year-old man developed blurred vision on January 20, 1981. He was pointed out of bitemporal hemianopsia and of his left palor optic fundus. His endocrinological condition was panhypopituitarism and no hypersecreting hormones were found. Cranial computerized axial tomography showed huge dumbbell shaped high density mass extending from the enlarged intrasellar area to the floor of the third ventricle. On treatment with bromocriptine, 5 mg daily for 3 days, his visual acuity and field was remarkably improved. Treatment was continued with gradually increased doses of bromocriptine to 15 mg and so, remarkable shrinkage of tumor size about 50% was seen by computerized axial tomography by a month. In addition, by eight months, the tumor reduced to 22%. Transsphenoidal surgery revealed centrally necrotic tumor mass surrounded by peripheral fibrous one. Because of fibrous and hemorrhagic tumour, we could not remove it totally. The pathological specimen was examined by light and transmission electron microscopy. The tumor was diffuse-type chromophobe adenoma partially intersected by hypertrophied fibrous interstitial materials. Some tumor cells were stained faintly eosinophilic. The cytoplasms were shrunken and the tumor cells were clumped. The immunostaining of tumor was negative to all anterior pituitary hormones. The intracytoplasmic organellae, for example, rough endoplasmic reticulum, Golgi apparatus, were scanty but prominant deformed mitochondria and small secretary granules (the size of about 90-150 nm) were found by transmission electron microscope. We think that the tumor cells had various responsiveness to this drug and the one extreme was destruction of the nucleus, the irreversible change, and the other extreme was some cytoplasmic reduction, the reversible change. The histopathological changes were almost the same as those of prolactinomas treated with bromocriptine. In conclusion, the mechanism of shrinkage of nonfunctioning pituitary adenomas treated with bromocriptine is unclear but it is worth while treating inoperable or recurrent large nonfunctioning pituitary adenomas with bromocriptine.

Adenoma↗
PubMed1983

A histopathologic study of benign and malignant lymphoepithelial lesions of the parotid gland.

Twenty-three cases of benign and malignant lymphoepithelial lesions without Sjögren's syndrome were examined: 21 were classical benign lymphoepithelial lesions, and were mostly found in males older than 50 years of age. The other two cases were identified as undifferentiated carcinoma arising from benign lymphoepithelial lesion (8.7%; 2/23). Histologically, this carcinoma is characterized by the formation of cell nests of variable size and by marked lymphoplasmacytic infiltrations into the stromal tissue. In immunofluorescence, an increase of plasma cells containing IgA and IgG was noted in the marginal areas of carcinoma cell clusters. Electron microscopy disclosed that the carcinoma was composed of poorly differentiated cells with occasional squamous differentiation. No dysplastic characteristics were found in the infiltrating lymphocytic components. These two cases of carcinoma were found in middle-aged females.

Adult↗