Biomedical subjects
Publications and source records attributed to Y Masuda.
A 69-year-old man and a 54-year-old woman with situs inversus totalis were admitted to our hospital for surgery for gastric malignant disease. The diagnosis was made radiologically and successful total gastrectomies were performed.
The morphological examination of the left ventricular trabeculae was performed using MRI (0.5T) in 14 normal volunteers, 12 patients with dilated cardiomyopathy (DCM), and 9 patients with old myocardial infarction (OMI). Left ventricular trabeculae were observed at the free walls of the left ventricle in all subjects, but not at the septal wall. Left ventricular trabeculae were larger in DCM than in the normals. The trabeculae were scarce in OMI and inner sides of the infarcted myocardium were very smooth. The development of the left ventricular trabeculae was graded as diminished, ordinary, and marked. Ordinary trabeculae were seen in 86% of the normals, whereas; marked trabeculae in 75% of DCM, and diminished trabeculae in 78% of OMI. In patients with DCM, the mean area of the left ventricle with marked trabeculae was greater than that with ordinary trabeculae. The more dilated left ventricle, the thinner the anterior wall was and the lower the ejection fraction was in DCM and OMI, though there were no significant differences in values of these 3 items between DCM and OMI. The MRI findings on the development of the trabeculae were confirmed in patients with DCM at autopsy. Thus, the MRI findings were very useful in the differential diagnosis between DCM and OMI.
To compare the clinical difference of posttetanic count (PTC) during onset and spontaneous offset, the changes of PTC during an intense neuromuscular blockade induced by vecuronium (0.08 mg.kg-1, i.v.) were measured using a neuromuscular transmission analyzer in 64 adult patients anesthetized with nitrous oxide and halothane. Furthermore, intubation score was evaluated when zero PTC was obtained. The obvious movement of diaphragm associated with endotracheal intubation was observed in 9 out of 20 patients (45%) even when it was performed after obtaining zero PTC. The difference of PTC responses between the onset and the offset was found. The difference was that, during the onset, a tetanic response was observed obviously and the height of the posttetanic single twitch was low, and during offset, even when no response was observed, the height of a posttetanic single twitch response was high with the same PTC. These facts indicate that the same PTC has different clinical significance during onset and offset.
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Mice were housed in a cage with a T-maze for 7-9 h a day. A watering place was equipped at one end of the maze. At the other end of the maze, the right and left arms each have two exits, one of which leads to the home cage where food is placed, and the other of which leads to the watering place via a bypass. The exit leading to the home cage in either the right or left was alternately closed every two hours. One-way swinging doors were inserted at the entrance to each arm and between each bypass and the watering place. The mice housed in this apparatus acquired the alternation task at 5 s delay on the 6th day. As the delay became longer (5-150 s), correct response rate showed gradual decrease. Scopolamine (0.1-0.4 mg/kg) did not decrease correct response rate at 5 s delay, but did at longer delay (30 s and 60 s). These results suggest that this method is useful in estimating working memory of mice.
To evaluate the effect of smoking on nonrespiratory function in the lung, a dynamic PET with 13NH3 in the lung was performed in 18 normal volunteers without lung disease nor congestion (9 non-smokers, 4 exsmokers, 5 smokers). After intravenous bolus injection of 13NH3, twenty serial 5.5-second scans followed by six 30-second scans were performed. Regions of interests were assigned on the ventral, lateral and dorsal part of the right lung and time-activity curves were generated through 26 images. The activity curve demonstrated a biexponential clearance from the lung with fast and slow component. The retention fraction (RF), fractional size of the slow component, was calculated, and the half-times (t 1/2) of both components were also evaluated. A significant increase of RF and prolongation of t 1/2 of slow component were observed in smokers compared to non-smokers and exsmokers. However, no significant difference of RF nor t 1/2 of both components was observed between non-smokers and exsmokers. These results suggest that long term smoking may modify the pulmonary kinetics of 13NH3, but the change is reversible after cessation of smoking for one year or longer.
A 63 year old man underwent MCA aneurysmal neck clipping under O2-N2O-enflurane anesthesia. On the 46th postoperative day after the first operation, he had cranioplasty under O2-N2O-sevoflurane anesthesia. Hepatic injury occurred after the operation, and GOT, GPT and bilirubin increased above 700 IU.l-1, 800 IU.l-1 and 15.0 mg.dl-1 respectively but consciousness disturbance, hyperammonemia and DIC did not appear. His hepatic injury improved on conservative therapy. It seems that his hepatic injury was not caused by hepatitis viruses or hepatotoxicity of any drugs, but caused by cross sensitization between halogenated inhalation anesthetics, especially enflurane and sevoflurane, judging from drug induced lymphocyte stimulating test (DLST). We have to select an anesthetic method considering potential hepatic injury by halogenated anesthetics in a case of repeated anesthesia and operations during a short-term.
The purpose of this study is to compare the characteristics of images obtained by positron emission tomography (PET) using 18F-fluorodeoxyglucose (FDG) in the fasted state (> 6 hours) and in the glucose-loaded state (oral 50 g glucose load). In the both condition FDG-PET were performed in 18 cases with old myocardial infarction. PET images in the fasted state were divided into 2 groups (Group A; 12 cases and Group B; 6 cases). FDG uptake of normal region was visually absent (grade 0) in group A, whereas it was visually apparent (grade 1-3) in group B. Serum free fatty acid in group B was significantly lower than that in group A. In the 7 cases, the relation between myocardial FDG uptake of the infarcted regions and reversibility after coronary intervention was studied. Both in the fasted and in the glucose-loaded state, postoperative improvement was observed in the segments, in which myocardial uptake of FDG were visually apparent (glucose-loaded state, 11/13 segments; fasted state, 6/8 segments). Therefore FDG-PET images appeared to be useful for evaluating myocardial viability.
Lucas-Schmidt IIA type of Cor triatriatum has been rarely reported. Since it shows the same hemodynamics as Darling IIb type TAPVC, it is important as a emergent surgical case in early infancy. We reported a male neonate with IIA type Cor triatriatum. He was admitted to our hospital because of cyanosis and dyspnea since birth. The echocardiographic examinations revealed the accessory chamber behind the left atrium and atrial septal defect. The view from the right atrium revealed that there was no direct connection between the accessory chamber and the true left atrium, and we diagnosed it Lucas IIA type Cor triatriatum. The abnormal diaphragma was resected, and the atrial septum was corrected with a Xenomedica patch. The patient had an uneventful postoperative course, and was discharged on the 25th postoperative day.
Historically, various types of antibiotic-associated diarrhea have been recognized. In the 1950-1960s, multi-resistant Staphylococcus aureus was implicated to be major cause of antibiotic-associated diarrhea, especially pseudomembranous enterocolitis. In the late 1970s, a new type of antibiotic-associated diarrhea, which is characterized by pseudomembranous colitis and lack of fecal multi-resistant S. aureus, usually following lincosamide administration, was recognized. Many studies have revealed the pathogenic roles of Clostridium difficile in these patients. Recent emergence of methicillin resistant S. aureus (MRSA) provokes another type of antibiotic-associated diarrhea. We have tried to isolate S. aureus and C. difficile from 150 faecal samples of patients with antibiotic-associated diarrhea. S. aureus alone was isolated from 32 (21.3%) samples. C. difficile alone was isolated from 51 (34.0%) samples, and, both were detected in 23 (15.3%) samples. 90.9% of S. aureus were MRSA. Comparing the clinical features of these cases, patients with both C. difficile and MRSA showed more serious clinical features. The patients who had undergone laparotomy were accompanied by shock and meteorism, more often than patients without laparotomy. The management of antibiotic-associated diarrhea due to MRSA is discussed.
Wide spread of MRSA infection in geriatric hospitals indicated two important problems which must be resolved. One is how we can eradicate MRSA in the elderly, and the other is how we can control cross infections of MRSA within the hospital. The presence of infected decubital ulcers in the elderly make it difficult to answer these problems. Usually, MRSA and Pseudomonas aeruginosa which is isolated from decubital ulcers act as colonizers on the surface of granulated wounds but do not contribute to clinical symptoms. However, these colonizers can be the source of cross infection toward other debilitated patients. The actual management for decubital ulcer infected by MRSA are discussed from the above viewpoints.
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In order to clarify the physiological significance of sulfate conjugation of catecholamines and the effect of continuous dopamine infusion on the conjugate formation, we measured the plasma levels of free and sulfoconjugated catecholamines during the perioperative period of cardiac operations. The study group consisted of 12 adult patients who underwent cardiac operations. There were 13 study intervals starting from a day before each operation to 72 hours after each operation for the collection of blood specimen. The plasma levels of free and sulfoconjugated catecholamines were measured by radioenzymatic assay. The plasma levels of free dopamine did not show significant change by the induction of anesthesia, but they increased rapidly after the start of dopamine infusion to the level of 7654.9 +/- 731.7 pg/ml. Thereafter, the plasma free dopamine levels remained steady during the 24 hours after operation at 7516.7 pg/ml to 8449.2 pg/ml. On the other hand, the plasma levels of conjugated dopamine increased progressively by dopamine infusion during the 24 hours after operation. The plasma levels of free adrenaline increased significantly to the level of 1049.5 +/- 117.7 pg/ml by dopamine infusion, and lasted with plateau until the 24th hour after operation at the range of 1076.8 pg/ml to 1218.9 pg/ml. Conjugated adrenaline followed a similar pattern to that of conjugated dopamine, with a progressive increase due to the infusion of dopamine. In the case of noradrenaline, free noradrenaline started to increase at the time of cardiopulmonary bypass and showed a further increase by dopamine infusion during the first hour after operation.(ABSTRACT TRUNCATED AT 250 WORDS)
A 64 year-old female patient of idiopathic myelofibrosis (IMF), who had had rapidly progressing massive splenomegaly and severe pancytopenia refractory to blood transfusion, was treated with PSL 0.6 mg/kg/day for a month, being significantly improved not only symptomatically and hematologically but also in bone marrow hematopoiesis. Although the effectiveness of PSL to restoration of bone marrow hematopoiesis has been almost unknown, long term oral PSL should be tried for a certain phase of IMF.
Octa-heme peptide (CHP) obtained from Candida krusei cytochrome c was tested for suicidal activation of halogenomethanes. Under anaerobic conditions, CHP was kept in the reduced state in the presence of NADPH and NADPH-cytochrome P-450 reductase. Addition of CBrCl3 to the reduced CHP caused spectral changes such as rapid disappearance of alpha and beta bands and gradual decrease in the gamma-peak height, accompanied by oxidation of NADPH. Heme content of the reaction mixture, determined as pyridine hemochrome, also decreased NADPH dependently. CCl4 was less effective than CBrCl3, while CHCl3 had almost no effect. N-tert-butyl-alpha-phenylnitrone (PBN) suppressed the CBrCl3-induced heme damage, and resulted in the formation of radical adduct .PBN-CCl3 as evidenced by ESR spectroscopy. Radical formation was also observed with CCl4. The CHP damage induced by CBrCl3 was also accompanied by the release of Br- about 11-12-times molar excess of CHP, whereas the release of CHCl3 was about 20% that of Br-.FD-MS assay of the product of CHP reaction suggested that 10 trichloromethyl radicals bonded with CHP. Thus, CBrCl3 undergoes single-electron reduction in the presence of reduced CHP to trichloromethyl radicals, which covalently bind to CHP molecules. Heme peptide may be a useful tool in the study of mechanisms involved in the destruction of cytochrome P-450 by halogenomethanes.
To elucidate the mechanism of palytoxin (PTX)-induced Na+ influx, we examined the effect of amiloride, an inhibitor of Na+/H(+)-antiporter, on PTX-induced Na+ influx into cultured bovine adrenal chromaffin cells in relation to its effects on Ca2+ influx and catecholamine secretion. Amiloride dose-dependently inhibited PTX-induced 22Na+ influx, whereas tetrodotoxin (TTX) had no effect. Amiloride also inhibited PTX-induced Na(+)-dependent 45Ca2+ influx and catecholamine secretion. PTX alone did not significantly affect the intracellular pH, but it decreased in the presence of PTX and amiloride. These results indicate that an amiloride-sensitive Na+/H+ exchange mechanism is probably involved in PTX-induced, TTX-insensitive Na+ influx that triggers Ca2+ influx and catecholamine secretion from the cells.
Human T-cell leukemia virus type I (HTLV-I) is associated with adult T-cell leukemia/lymphoma (ATLL). To examine the relationship between defective HTLV-I proviruses and clinicopathological features, we examined 95 patients with ATLL showing clonal integration of HTLV-I proviral DNA; 77 patients (81%) showed 1 clonal band, 15 (16%) showed 2 clonal bands, and 3 (3%) showed 3 clonal bands. In addition, the defective proviral form was detected in 28 patients (29%): 23 (30%) of the 77 with 1 clonal band, 4(27%) of the 15 with 2 clonal bands, and 1(33%) of the 3 with 3 clonal bands. The numbers of clonal bands had no association with the presence of defective proviruses. We classified the 95 patients with ATLL into four types according to clinicopathological features (smoldering leukemia, chronic leukemia, acute leukemia, and lymphoma types). The distribution of patients with the defective form was not different among these four types. The HTLV-I genomes must have integrated into the human genome DNA and been deleted partially in the cells. The defective form was kept during the clinical stage. All patients with the defective form showed defect of the gag or/and env region. No patient had a defect of the pX region. These data suggest that the pX region of HTLV-I must have played an important role in ATLL genesis.
Distribution of pituitary adenylate cyclase activating polypeptide (PACAP) binding sites was investigated in the rat brain and pituitary gland by means of in vitro autoradiography. High densities of specific [125I]PACAP binding were observed in the anterior pituitary, hippocampus (CA1-4 and dentate gyrus) and in the superior colliculus. Moderate to high labeling was observed in the periaqueductal gray matter, substantia nigra pars compacta, and in the habenula. The hypothalamus, thalamus, ventral tegmental area (VTA), mammillary body and medial geniculate body were moderately labeled. The present results support possible actions of PACAP on the pituitary functions, and further suggest that PACAP is a neurotransmitter/neuromodulator in the central nervous system.