Biomedical subjects
Publications and source records attributed to Y Uchida.
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Conversion of percutaneous transhepatic cholangiodrainage to an internal drainage is safe and effective in rerouting bile back to the intestinal tract in obstructive jaundice without major operative procedure. The method consists of insertion of a drainage tube with several side holes beyond the bile duct stricture. Usually, a single lumen tube is used. However, double lumen tube is preferred when the amount of bile discharge is excessive. This simple technique is found to be useful in the management of obstructive jaundice not only for preoperative decompression of biliary tree but also for the inoperable lesions.
Neuraminidase [sialidase, EC 3.2.1.18] was found to be widely distributed in bacteria belonging to Arthrobacter. Among these bacteria, Arthrobacter ureafaciens, A. oxydans, and A. aurescens produced relatively potent neuraminidase activities. For the production of this enzyme, not only colominic acid, a homopolymer of N-acetylneuraminic acid, but also N-acetylneuraminic acid, the reaction product of this enzyme, are effective as sources of carbon. An affinity adsorbent specific for neuraminidase was prepared by cross-linking colominic acid with soluble starch by means of epichlorohydrin. Neuraminidase from A. ureafaciens could be purified on this affinity column. The purified neuraminidase was shown to be free from protease, N-acetylneuraminic acid aldolase, phospholipase C, and glycosidases. Aminoff's assay procedure for sialic acid was modified to avoid the centrifugation step. The modified procedure gave a higher molecular extinction coefficient.
Mechanisms for cyclical reduction in peripheral blood pressure and flow of partially constricted coronary artery of anesthetized dogs has been examined. In 64 of 97 preparations, cyclical reduction in coronary blood pressure and flow developed 3 to 32 min after the beginning of constriction. Period duration of the cyclical reduction ranged from 1 to 32 min. The cyclical reduction was frequently associated with elevation of the ST segment of surface electrocardiogram, systolic bulge of the left ventricle and excitation of afferent cardiac sympathetic nerve fibers. In the preparations in which cyclical reduction was not produced by constriction, a brief stretching of the constricted portion provoked the cyclical reduction. Segmental or diffuse narrowing of the constricted coronary artery which occurred during the reduction in pressure and flow was demonstrated by selective arteriography. Also, segmental spasm in the constricted coronary artery was demonstrated by photography. No obvious difference in the constricted of the artery was observed histologically between the preparations in which cyclical reduction developed and those in which cyclical reduction was not produced. The results indicate participation of vasospasm in the cyclical reduction of blood pressure and flow in partially constricted coronary artery.
Applicability of ultrasonic analogue conversion system devised by us for assessments of left ventricular volume was examined in patients with and without heart disease. The conversion system could sample the echoes from the endocardial surfaces of the interventricular septum and the posterior left ventricular wall. The conversion system could also calculate automatically the minor axis and volume of the left ventricle. End-diastolic, end-systolic, and stroke volumes calculated by the conversion system were close to those calculated from biplane ventriculograms and to those calculated from photographic records of B-mode echo-display. Change in left ventricular volume caused by respiration ranged up to 17.5%. Spontaneous variations in left ventricular volume during continuous monitoring was up to 7.5%. End-diastolic, end-systolic, and stroke volumes were reduced by sublingual administration of nitroglycerin. The results indicate applicability of the ultrasonic analogue conversion system for continuous assessments of left ventricular volume in man.
A new time-to-voltage analogue converter of ultrasound echo was made. The converter samples the echoes from the septal endocardium and the endocardium of the posterior wall of the left ventricle. The converter also enables automatic calculates left ventricular minor axis, volume, and work. In fixed human hearts, the left ventricular minor axis and volume calculated by the converter were close to the actual ones. In anesthetized dogs, left ventricular minor axis, volume, ejection fraction and stroke work calculated by the converter were close to those calculated by cineventriculography. The results indicate applicability of the ultrasonic analogue converter for instantaneous assessments of left ventricular dimensions and function.
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For the purpose of quantitative demonstration of the sensitivity to chlorpromazine (CPZ) effects on brain functions of schizophrenics and normal subjects, polygraphic recordings of electroencephalogram (EEG) and electrodermal response (EDR) were performed before and 3 h after oral administration of 25 mg of CPZ: percent time waking EEG (per cent W-EEG) and number per minute of EDR were measured during the resting period and the period of calculation. In 10 normal adult subject, both per cent W-EEG and number of EDR showed remarkable decrease after CPZ administration. In 22 schizophrenics, however, per cent W-EEG showed no significant decrease after CPZ administration. Number of EDR in schizophrenics during the period of calculation did not show any significant decrease. The neural mechanism underlying the lower sensitivity to CPZ effects in schizophrenics was discussed.
In the present study an ultrastructural morphometric analysis of the rat liver 1, 3 and 7 days after bile duct ligation was performed. Corresponding biochemical investigations included the determination of the cytochrom P 450 contents in the microsomal fraction. In the serum of the rats the activities of GOT and GPT were determined. The quantitative results have shown that the decreased P 450 contents of the microsomal fraction coincided with a considerable increasement of the surface of the smooth endoplasmic reticulum. The smooth endoplasmic reticulum was significantly increased from 1.83 m2/cm3 hepatocytes to 3.49 m2/cm3 hepatocytes after 3 days and remained on this level after 7 days. These results may be considered as quantitative evidence for the term hyperplastic, hypoactive endoplasmic reticulum. - As a second important result our quantitative investigations have shown that the increasement of GLDH activity in the serum especially 1 day after ligation of the bile duct coincided with a signficantly increased mitochondrial volume at this time.
Corresponding to the increased activity of mitochondrial Glutamate-Dehydrogenase (GLDH) in serum in extrahepatic cholestasis a swelling of hepatic mitochondria could be shown on ultrastructural morphometric analysis. The morphometric alterations parallel the serochemical findings. A significant correlation could be calculated between the swelling of mitochondria and the activity of GLDH in serum.
The status of cell-mediated immunity was studied in 360 patients with gastric cancer before surgery. For the skin test, tuberculin and DNCB were employed. For the in vitro test, the blastogenesis of peripheral blood lymphocytes to phytohemagglutinin (PHA), the ratio of rosette-forming T cells to sheep blood red cells, and the macrophage migration inhibiotry factor against autochthonous tumor antigens were measured. As a result, it was found that in progressive gastric cancers the cell-mediated immunity decreased specifically or nonspecifically, especially the DNCB reaction; and the blastogenesis against PHA showed an inverse correlation to the advance of gastric cancer.
We devised a direct percutaneous transhepatic cholangial drainage under fluoroscopic control. The principle is as follows. After percutaneous transhepatic cholangiography, the three dimensional structure of intrahepatic bile ducts is projected to a two dimensional plane under fluoroscopy; the needle can then be introduced into the selected bile duct with accuracy. The technique can be used as a preoperative management of operations of patients with jaundice and also as a palliative management of advanced cancer without much complication.
Experimental carcinomas in the glandular stomach of rats were induced by oral administration of MNNG (M-methyl-N'-nitro-N-nitrosoguanidin) for 35 weeks or ENNG (N-ethyl-N'-nitro-N-nitrosoguanidin) for 20 weeks. Rats were killed at different times after beginning of carcinogen treatment and tissue specimens were prepared for histologic investigation. Particular interest was placed on the development of tumors and on pathological findings possibly contributing to early diagnosis of stomach cancer. During the development of tumors, several dysplastic reactions were observed in the antral mucosa. They could be classified into 4 groups: One was regenerative hyperplasia (1) that meant irregular glandular proliferations without cell atypism at the margin of erosions and ulcers. This lesion was mainly found 1-9 weeks after administration of MNNG. In glandular hyperplasia (2) either crypts or glands were extended and mucosal layers were thickened. No signs of cell atypism were observed. This lesion was mainly found 12-17 weeks after administration of MNNG. Dysplasia (3) was combined with considerable structural modifications and cellular atypism. However, this lesion was limited to the mucosal layer. Neoplastic changes (4) were characterized by marked cellular atypism and extension to tunica submucosa and tunica serosa. Some tumors showed the histological patterns of benign tumors, but most of them were adenocarcinomas. In some cases metastases into pancreas, liver and lymph nodes and in one case into the 12th rib were observed. No particular enzyme patterns were found by histochemistry.
In the present study electron microscopic investigations of tumors of the glandular stomach of rats induced by oral administration of MNNG or ENNG are dealt with. The aim of the study was to describe the different cell types found in the carcinoma and to elucidate the possible relationship between the undifferentiated carcinoma cells and the more differentiated cell types found in the tumor. The results show that besides undifferentiaded carcinoma cells, several differentiated cell types such as goblet cells, endocrine cells, cells with lamellated inclusions in their cytoplasm, and squamous carcinoma cells can be observed. The most conspicuous findings were carcinomatous gland cells with well differentiated microvilli on their luminal surface and typical tonofilamentous structures in their cytoplasm. These cells exhibited signs of the squamous epithelium and of gland cells. Therefore they may be considered as intermediate variants between adenocarcinoma cells and squamous carcinoma cells. The occurrence of such intermediate steps points to the possibility of differentiation by cell division of adenocarcinoma cells into several metaplastic cell types in the experimental stomach carcinoma induced by MNNG or ENNG.
The role of afferent cardiac sympathetic nerve fibers in the regulation of respiration has been examined. Application of potassium chloride or lactic acid solutions to the left ventricular surface of anesthetized vagotomized dogs resulted in a decrease in the manimum firing rate and shortening in period duration of firing of phrenic nerves. Also, application of the agents caused a decrease in amplitude and an increase in rate of respiratory thoracic movements. The same changes in phrenic nerve activity and respiratory movements were produced by coronary artery occlusion and centrifugal electrical stimulation of the left inferior cardiac nerves. The results indicate tachypnea that can be produced by excitation of afferent cardiac sympathetic nerve fibers.
The effect of diltiazem hydrochloride on left ventricular function has been examined in patients with and without angina pectoris. Left ventricular volume and function were measured by ultrasonic analogue conversion system. In 12 patients without angina pectoris, a fall in systemic blood pressure, a decrease in heart rate, no change in EDVI, an increase in ESVI, decreases in CI, EF, endocardial mean Vcf, normailized mean systolic ejection rate, SWI, and W/min while no change in systemic vascular resistance were observed following the intravenous injections of 40 mug/Kg of the agent. In 10 patients with angina pectoris, decreases in EDVI and ESVI, no change in CI, a tendency of increases in EF, endocardial mean Vcf, and normalized mean systolic ejection rate were observed following the administrations of the same dose. Changes in systemic blood pressure, heart rate, SWI, W/min, and systemic vascular resistance were the same as those in patients without angina pectoris. The results indicate diltiazem-induced reduction in left ventricular function in patients without angina pectoris whereas improvement in left ventricular function in patients with angina pectoris.