Biomedical subjects

Y Imamura

Publications and source records attributed to Y Imamura.

At least 253 records · Page 14Linked to original sources

PubMed1992

[A case of rectus sheath hematoma].

The following is a rare case of rectus sheath hematoma. The patient was a 78-year-old man with a past history of axillo-femoral bypass operation. He contracted a cold, and when he coughed severely, acute lower abdominal pain occurred. Abdominal echography and CT scanning confirmed the presence of a hematoma in the rectus abdominis muscle. Before, patient was diagnosed as acute abdomen and surgery was performed. Recently, accurate diagnosis has been made easily by echography or CT.

Abdomen, Acute↗

PubMed1992

[A case of pulmonary tuberculosis associated with severe respiratory failure, DIC and intractable bilateral pneumothoraces].

We had a sixty-five year old male patient who suddenly complained of dyspnea and fever with pulmonary tuberculosis, severe respiratory failure, disseminated intravascular coagulation (DIC) and intractable bilateral pneumothoraces. From the first hospital day severe hypoxemia which did not respond to conventional oxygen therapy developed with a diffuse ill-defined reticulo-nodular shadow in the plain chest x-ray film. On the 2nd hospital day mechanical ventilation with 2cmH2O PEEP was introduced. Antituberculous agents as well as corticosteroids were started suspecting acute interstitial pneumonia with pulmonary tuberculosis and adult respiratory distress syndrome (ARDS). Medication was followed by the treatment of Gabexate mesilate and heparin against DIC on laboratory data. Though clinical findings and pulmonary infiltrate on chest x-ray film transiently improved, right pneumothorax occurred suddenly on the 6th day followed with left pneumothorax on the 36th day. Tube drainage of both pleural spaces and repeated instillation of thrombin-rich oxycel cotton via bronchofiberscope failed to stop air leakage. He ultimately expired on 49th hospital day. At postmortem lung had multiple bilateral bulla several of which ruptured to the pleural site and caseating necrotic area containing bacilli positively stained with Ziehl-Nielsen stain in the bilateral upper lobe. No typical caseating necrotic lesion, however, was found in the other lung tissue. Therefore, it seemed to show a chronic phase of diffuse alveolar damage (DAD).

Aged↗

PubMed1992

Factors affecting acetohexamide reductase activities in microsomes and cytosol from the kidney of male rats: age and castration.

Acetohexamide reductase activity in microsomes from the kidney of male rats increased markedly at puberty to approach the maximum level at 8 weeks of age; it was not detected until 4 weeks of age. Furthermore, castration suppressed effectively the activity in kidney microsomes at 8 weeks of age. These findings clearly indicate that the activity in kidney microsomes can be regulated by androgens. On the other hand, in cytosol from the kidney of male rats, a higher acetohexamide reductase activity was observed at all weeks of age tested. Castration had no significant effect on the activity in kidney cytosol.

Aging↗

PubMed1991

Animal model of systemic carnitine deficiency: analysis in C3H-H-2 degrees strain of mouse associated with juvenile visceral steatosis.

We analyzed carnitine profiles in C3H-H-2 degrees strain of mouse associated with fatty liver, hyperammonemia and hypoglycemia (Koizumi et al., 1988). Carnitine levels in serum, liver and muscle of mouse with fatty liver were markedly decreased in comparison with those of control mouse (littermates without fatty liver). This is a useful animal model to analyze the role of carnitine in lipid, amino acid and carbohydrate metabolism.

Aging↗

PubMed1991

Follow-up of asymptomatic HTLV-I carriers among blood donors in Kyushu, Japan.

We examined mortality from adult T-cell leukemia/lymphoma (ATL/ATLL) and other diseases alleged to be associated with human T-lymphotropic virus type I (HTLV-I) among anti-HTLV-I antibody-positive blood donors in Kyushu, Japan. During 1984-87, a total of 3,991 blood donors aged 40 years or over were followed from the date of donation to the date of death or the end of the study. Crude mortality rates from ATL (with 95 percent confidence intervals) were 68 per 100,000 (13-202) for males and 36 per 100,000 (3-132) for females. The rates were underestimated by approximately 50 percent because of self-selection and short observation periods. Neither death rates from other cancers nor death rates from all cancers were elevated.

Adult↗

PubMed1991

Morphology and modes of cell proliferation in earliest signet-ring-cell carcinomas induced in canine stomachs by N-ethyl-N'-nitro-N-nitrosoguanidine.

Signet-ring-cell carcinomas were induced in the stomach of 12 beagle dogs by p.o. administration of N-ethyl-N'-nitro-N-nitrosoguanidine (ENNG), and the morphology and modes of cell proliferation in an incipient stage of cancer growth were studied with bromodeoxyuridine (BrdUrd) incorporation. From 5 to 27 months after the completion of 8 months' carcinogen treatment, minute carcinomas were found in the stomachs of 9 dogs. Before sacrifice, the dogs were given a single or repeated i.v. injections of BrdUrd for 1-3 days. Minute signet-ring-cell carcinomas were found to form a layered structure, in which the cancer cells proliferated in the lamina propria at the gland-neck level and differentiated to postmitotic signet-ring cells at the upper and lower levels of the mucosa. From repeated injections of BrdUrd, the time required for all the proliferative cells to be labelled with BrdUrd (reflecting the maximum cell-cycle time) was estimated to be 1.7 days for the normal glands, and 2.7 days for minute signet-ring-cell carcinomas. From the labelling index with BrdUrd as well as from the morphology, earliest carcinomas were identified in the single gland. There remained atrophic normal epithelium commonly in the single-gland lesions. Proliferative atypical cells appeared to be shed into the stroma passively through the atrophy and subsequent collapse of the gland rather than through active invasion. This may be a reason why cancer cells in minute signet-ring cell carcinomas preserved the normal pattern of cell renewal movement to form the layered structure.

Adenocarcinoma, Mucinous↗

PubMed1991

The influence of clinical use of antibiotics and the sensitivity of strains isolated from postoperative infections--a comparison of nosocomial pathogens with strains isolated from the bacterial flora of patients.

In the present study, we investigated how the recent clinical use of antibiotics have altered the antibiotic susceptibility of strains isolated from postoperative infections, especially Gram-negative rods. For Pseudomonas aeruginosa, serogroup E strains accounted for about 20 per cent of postoperative infections, but were unable to be isolated from either the feces of patients on admission or from the appendix contents of patients with appendicitis. It therefore appeared that serogroup E strains were responsible for the nosocomial infections in our department. The strains of methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa serogroup E, which we assumed to be nosocomial pathogens, acquired a high level of resistance to antibiotics soon after third-generation cephems became widely used. On the other hand, the antibiotic susceptibility of Enterobacter cloacae, Citrobacter freundii, and the serogroups of Pseudomonas aeruginosa other than E, which were considered to originate from the bacterial flora of patients, did not vary throughout the several years of the study period.

Bacteria↗

PubMed1991

Toxin involvement in methicillin-resistant Staphylococcus aureus enteritis in gastroenterological surgery.

The authors investigated the production of toxic shock syndrome toxin-1 (TSST-1) and staphylococcal enterotoxins (SE) by Methicillin-resistant Staphylococcus aureus (MRSA) isolates to clarify the pathogenesis of postoperative MRSA enteritis in patients undergoing gastroenterological surgery. Regarding the percentage of TSST-1 producing strains, there was a significant difference between type II MRSA strains (68.8%) and type IV MRSA strains (4.2%). Among type II strains, all those producing staphylococcal entorotoxin (SE) type C (SEC) also produced TSST-1, although other strains that produced SEB without TSST-1 were commonly isolated. Strains producing SEA were potent producers of SE which was considered to be responsible for enteritis. Therefore, we hypothesized that the strains which produced both SEA and SEC tended to cause enteritis associated with TSS-like symptoms owing to the high titer of these toxins.

Bacterial Toxins↗

PubMed1991

Analysis of the binding sites of Gd3+ on Ca(2+)-transporting ATPase of the sarcoplasmic reticulum through its effects on fluorescence of tryptophan residues and a covalently attached fluorescent probe N-(1-anilinonaphthyl-4)maleimide.

Interaction of Ca2+ and Gd3+ ions with Ca(2+)-transporting ATPase of the sarcoplasmic reticulum (SR-ATPase) was analyzed. Binding of Ca2+ to the transport site caused an enhancement of intrinsic fluorescence of SR-ATPase. Gd3+ also induced fluorescence enhancement. However, the effects of Ca2+ and Gd3+ were additive rather than competitive, indicating that the Gd(3+)-binding site responsible for this enhancement is distinct from the Ca(2+)-transport site. Gd3+ ions at concentrations higher than 10 microM caused a marked fluorescence quenching, indicating an additional interaction at low-affinity binding sites. Interaction of Ca2+ with the transport site led to a quenching of fluorescence of N-(1-anilinonaphthyl-4)maleimide (ANM) covalently attached at SHN [as defined in Yasuoka-Yabe, K. & Kawakita, M. (1983) J. Biochem. 94, 665-675]. In this case the effects of Ca2+ and Gd3+ were mutually exclusive, indicating that Ca2+ and Gd3+ were competing for the same binding site (i.e. the transport site) to affect ANM fluorescence. Competition between Ca2+ and Gd3+ for the Ca(2+)-transport site was also demonstrated by direct measurement of Ca(2+)-binding using nitrocellulose membrane filters. Affinity of Gd3+ for the Ca(2+)-transport site was a little lower than that of Ca2+. Based on these results it was concluded that Gd3+ has at least three kinds of binding sites on SR-ATPase, namely the Ca(2+)-transport site, the Gd(3+)-specific high-affinity site, and a number of low-affinity sites.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1991

Location of the Ca(2+)-transport site of Ca(2+)-transporting ATPase of the sarcoplasmic reticulum as determined by analysis of paramagnetic interaction between Gd3+ ions bound at the transport site and membrane-embedded nitroxide spin probes.

Gd3+ ions were bound to the Ca(2+)-transport site of Ca(2+)-transporting ATPase of the sarcoplasmic reticulum (SR-ATPase) and their effect on the ESR spectrum of spin-probes, which were attached to specific sites on SR-ATPase and embedded in the membranous lipid at various depths from the surface of the membrane, was studied. Spin-labeled reagents, 1-oxyl-2,2-dimethyl-oxazolidine derivatives of maleimidoethyl-keto stearate, collectively abbreviated as MSL(m,n) were mainly used for labeling SR-ATPase. They have Cm- and Cn-hydrocarbon chains, respectively, on both sides of the spin label, of which the Cm-hydrocarbon chain is located distal to the carboxyl group of the keto stearate moiety. Paramagnetic interaction between Gd3+ and a spin probe was detected by measuring the decrease in the intensity of the ESR signal of the probe. Displacement of Gd3+ from the Ca(2+)-transport site by Ca2+, which had been confirmed previously by using fluorescently labeled SR-ATPase (described in the preceding article), led to a significant reversal of the paramagnetic effect of Gd3+ on MSL(12,3) and MSL(10,5) attached to SR-ATPase. On the other hand, the effect of Gd3+ was not reversed by Ca2+ when SR-ATPase labeled with MSL(1,14) or a spin-label specific for the cytoplasmic domain was used. These results led us to conclude that the Ca(2+)-transport site of SR-ATPase is located in the membranous region of the molecule, but that the site is not very far from the surface of the membrane of the sarcoplasmic reticulum.

Animals↗

PubMed1991

Opposite effects of metoclopramide and propantheline on intestinal absorption of imipramine in rats.

Intraperitoneally administered metoclopramide (MCP) markedly increased the serum concentration of imipramine (IPM) soon after oral administration. In contrast, intraperitoneally administered propantheline (PPT) slightly decreased the serum concentration. The administration of these two drugs had no significant effect on the serum concentration of IPM after intravenous bolus administration. It was concluded from pharmacokinetic analyses and gastric emptying experiments that the administration of MCP markedly increased the rate of IPM absorption by counteracting the gastric emptying delayed by IPM, but that the administration of PPT slightly decreased the rate of IPM absorption by strengthening the gastric emptying also delayed by IPM.

Animals↗

PubMed1991

Improvement of the plaque technique for human rotaviruses: effect of fetal bovine serum, acetyltrypsin and agar.

Dilution of viruses, which were previously treated with 10 micrograms acetyltrypsin/ml, in MEM supplemented with 2.5% fetal bovine serum caused little damage of cell monolayers resulting in the formation of discrete plaques. When agar and acetyltrypsin were added to the overlay medium at the concentrations of 0.8% and 5 micrograms/ml, respectively, clear plaques were induced. Linear relationships were obtained between virus concentration and the number of plaques, thus the procedure described in this report might be used for reliable plaque assay of rotaviruses. Moreover, these conditions for plaque formation were successful for estimating isolated viruses, as well as standard strains.

Agar↗

PubMed1991

Blood pressure and heart rate variability in elderly patients with isolated systolic hypertension.

To investigate the circadian profiles of BP and heart rate in elderly patients with isolated systolic hypertension (ISH), the variability of BP and heart rate during day time (daytime) and the amplitudes of nocturnal fall were evaluated in ISH (n = 19) comparing with those of essential hypertensive patients (EHT, n = 18) and normotensive subjects (NT, n = 16) in the same age range. ISH showed a significantly wider BP variability during the day time and a greater amplitude of nocturnal fall compared with EHT and NT. However, the heart rate variability during the daytime and the amplitude of nocturnal fall were similar among the three groups. ISH showed a stronger correlation between BP and heart rate during 24 hours compared with EHT and NT. Approximately 80% of ISH showed a significant positive correlation between BP and heart rate. These results suggest that the BP of ISH patients is susceptible to fluctuations in autonomic nerve activity.

Aged↗

PubMed1991

[Evaluation of left ventricular systolic function reserve before and after percutaneous transluminal coronary angioplasty by isometric exercise Doppler and two-dimensional echocardiography].

Left ventricular systolic function reserve (LVSFR) was assessed by isometric exercise Doppler and two-dimensional echocardiography before and after percutaneous transluminal coronary angioplasty (PTCA) in 28 patients with coronary artery disease. Pulsed Doppler echocardiograms were obtained from the sample volume which was placed just below the aortic valve in the apical long-axis view. Three parameters, including peak velocity (PV), acceleration time (AT), and mean acceleration (ACC), were measured before and at the end of 2 min-handgrip exercise. The area reduction rate (AR) was calculated from the two-dimensional echocardiograms at the level of the papillary muscle in the short-axis view obtained at rest and at the end of exercise. Percent changes of these 4 parameters (%PV, %AT, %ACC, %AR) from at rest to the end of exercise were also calculated before and after PTCA. No significant changes were detected in PV, AT, ACC and AR at rest, before and after PTCA. Percent changes of PV, ACC, and AR increased significantly (p < 0.01), while those of AT decreased significantly after PTCA (p < 0.01). Our method proved to be useful for assessing LVSFR in coronary artery disease and the findings obtained using this method suggested that LVSFR can be alleviated by successful PTCA.

Aged↗

PubMed1991

[Effect of recombinant human erythropoietin (rEPO) on angina pectoris in patients with chronic maintenance hemodialysis].

We studied the effects of recombinant human erythropoietin (rEPO) on angina pectoris in patients with chronic maintenance hemodialysis. We evaluated hemodynamic changes and exercise tolerance in 6 patients underwent symptom-limited treadmill exercise tests, before and 3-months after treatment with rEPO. Hemoglobin concentration and hematocrit increased significantly from 8.1 +/- 1.0 to 10.3 +/- 1.1 g/dl, from 25.7 +/- 2.7 to 31.5 +/- 2.5%, respectively. Exercise duration increased significantly from 291 +/- 68 to 396 +/- 77 sec. Maximal oxygen uptake (VO2max) also increased significantly from 18.3 +/- 3.3 to 24.2 +/- 3.4 ml/kg/min during correction of anemia. Systolic blood pressure (SBP) and pressure rate product (PRP) at rest, and at maximal exercise showed no significant changes, on the other hand ischemic ST change at maximal exercise decreased significantly from 1.2 +/- 0.7 to 0.2 +/- 0.3 mm under 3-months treatment. Our results suggest that improvement of exercise capacity and ST depression in patients with chronic hemodialysis is the outcome of increased coronary oxygen supply with unchanged cardiac oxygen demand after correction of renal anemia treated with rEPO.

Adult↗

PubMed1991

Postnatal development of acetohexamide reductase activities in microsomes and cytosol of rat liver.

The postnatal development of acetohexamide reductase activities in liver microsomes and cytosol were examined in male rats. The developmental pattern of acetohexamide reductase activity in liver microsomes was distinguished from that in liver cytosol. Furthermore, acetohexamide reductase activity in liver microsomes was effectively suppressed by castration, but the activity in liver cytosol was not affected by castration. These results clearly indicate that enzymes with physiologically different roles can catalyze the metabolic reduction of acetohexamide in rat liver.

Age Factors↗

PubMed1991

[A case of cardiomyopathy due to allergic bronchopulmonary aspergillosis].

We report a rare occurrence of cardiomyopathy associated with allergic bronchopulmonary aspergillosis (ABPA). A 49-year-old man with a history of bronchial asthma was referred to the Matsuyama Red Cross Hospital for evaluation of the abnormal shadow on his chest X-ray. Laboratory examination showed blood eosinophilia and marked elevation of serum IgE concentration and IgE antibody to A fumigatus. The immediate and late skin reactivities to A fumigatus antigen were both positive. The diagnosis of ABPA was made. Treatment using prednisolone was effective in ameliorating the symptoms. However, he was admitted again due to dyspnea, edema and anorexia 6 months later. Chest X-ray, ECG, UCG and scintigraphy suggested severe cardiac failure. The clinical diagnosis of hypertrophic cardiomyopathy, and the pathohistological diagnosis of endomyocardial fibrosis were made by cardiac catheterization and biopsy of endocardium. Retrospectively, cardiomegaly had gradually increased during the past several months while peripheral blood eosinophilia had continued. All these data strongly suggested that eosinophilia due to ABPA might cause severe cardiac damage.

Aspergillosis, Allergic Bronchopulmonary↗

PubMed1991

[Effects of depth on the display of color Doppler flow imaging with transesophageal and transthoracic transducers: an experimental study].

Transesophageal color Doppler flow imaging has proved to provide an accurate and sensitive information for diagnosis of valvular regurgitation. However, it is necessary to understand the difference in the display of color Doppler image between transesophageal and conventional transthoracic transducers for quantitative assessment of valvular regurgitation. In this study, the effects of the depth between transducer and jet flow on color Doppler flow imaging were evaluated with the transesophageal (3.75 MHz) and conventional (2.5 MHz) transducers by using a flow phantom. A flow circuit was filled with saline in which nylon corpuscles (average diameter; 5 microns) were suspended to enhance the Doppler effects. A turbulent jet with constant flow velocity (Reynolds number; 3500) stimulating valvular regurgitant flow was produced in a water bath through a small orifice (2 mm) by constant driving pressure (100 mmHg). Color jet imaging in the long- and short-axis views were observed at each depth with both transducers. The measurement was made every 1 cm in depth from 3 to 12 cm. The color gain setting was fixed at the optimal point so as to get the maximal flow image with the minimal static background noise. We obtained larger image of the color jet signal with the conventional than the transesophageal transducer. Although a mosaic pattern was displayed more distinctly with the transesophageal transducer compared with that of the conventional transducer, the transesophageal image tended to become indistinct in the depth deeper than 8 cm. On the other hand, the transthoracic image was maintained relatively constant at any depth.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Flow Velocity↗