Search PubMed⌕ Search

Biomedical subjects

T Shima

Publications and source records attributed to T Shima.

At least 127 records · Page 7Linked to original sources
PubMed1994

[Evaluation of angiographic delayed vasospasm due to ruptured aneurysm in comparison with cerebral circulation time measured by IA-DSA].

Delayed vasospasm due to ruptured aneurysm has been basically evaluated by angiographic changes in contrast to clinical features such as delayed ischemic neurological deficits (DIND). However, the discrepancies between angiographic and clinical findings have been pointed out. In this study, angiographic changes and cerebral circulation time in ruptured aneurysms were simultaneously investigated with IA-DSA. Thirty-two patients, who had ruptured aneurysms at the anterior circle of Willis and neck clippings at the acute stage, were investigated. Carotid angiogram was performed with IA-DSA on the 7-13th day after the attack. Angiographic changes were evaluated by Fischer's classification and circulation time was calculated in the following way. A time-density curve was obtained at the two ROI's; the C3-C4 portion and the rolandic vein. Circulation time was defined by the difference between the time showing peak optical density at the carotid and the venous portion. The control value of this circulation time obtained from 20 cases with non-rupture aneurysm and epilepsy was 3.4 sec (53 year old) on the average. X-ray CT scan examination was performed at the same time and clinical features were observed everyday. Angiographically, 3 cases were free from vasospasm, 18 cases were found to present slight to moderate vasospasm, and 11 cases showed severe vasospasm. Circulation time in patients with no spasm was 3.6 seconds, in patients with slight to moderate vasospasm it was 4.3 seconds and in patients with severe vasospasm it was 6.8 seconds. Ten patients showing cerebral infarction on CT scans demonstrated significantly long circulation time, 7.0 second on the average.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Experimental allergic myositis in SJL/J mice immunized with rabbit myosin B fraction: immunohistochemical analysis and transfer.

Experimental allergic myositis (EAM) was produced in SJL/J mice by inoculation with the myosin B fraction of the rabbit skeletal muscle, and the pathological changes were quantified. The myosin B fraction contains actin, myosin, tropomyosin and many other proteins, and has been known to induce severe EAM in guinea pigs. In the present model, macrophages and CD4+ lymphocytes predominated among the infiltrating cells. On the surface of muscle fibers and in the regions of cell infiltration deposition of the immunoglobulin G (IgG) and complement factor 3 was observed. EAM was transferred to normal mice by injecting the serum IgG of EAM. Depleting the recipients of complement before the transfer resulted in less-severe pathological changes. Morphologically, the EAM IgG showed an affinity for the nuclei, myofilaments, sarcolemma and blood vessels of mouse skeletal muscle. Biochemically EAM IgG contained antibodies against myosin, actin, troponin, M protein and other muscle proteins. These results indicated that IgG and complement play important roles in this model.

Animals↗
PubMed1993

Effects of bile acids and taurine on the lipid fluidity of hepatic microsomes in normal and bile duct-ligated rats--a spin label study.

In cholestasis and obstructive jaundice, hepatic bile acids and taurine content increase significantly and bile acids change in compositions. For example, increases in cholic acid, beta-muricholic acid and taurine-conjugated bile acids occur in rats. In this study, to clarify the significance of changes in bile acid composition in obstructive jaundice, the effects of various bile acids and taurine on the fluidity of the hepatic microsomal membrane were studied by the electron spin resonance spin-label method in normal and bile duct-ligated (for 10 days) rats. The flow properties (order parameter) of the shallow and deep layers of the membrane were determined with 5- and 12-doxyl stearic acid, respectively. Bile acids mainly affected the fluidity of the shallow membrane layer. The fluidity of the hepatic microsomal membrane was decreased in bile duct-ligated rats. Conjugated cholic acid (taurine-conjugated cholic acid, glycine-conjugated cholic acid and non-conjugated beta-muricholic acid exerted effects that increased fluidity in comparison with non-conjugated cholic acid and chenodeoxycholic acid, a precursor of beta-muricholic acid. Taurine had no clear effect on fluidity. In conclusion, cholic acid conjugation and beta-muricholic acid formation may be mechanisms which protect against the decrease in lipid fluidity of hepatic biomembranes in cholestasis or obstructive jaundice. Taurine may also affect fluidity through the formation of taurine-conjugated bile acids.

Animals↗
PubMed1993

Hemodynamic study on flow patterns in the carotid bifurcation before and after carotid endarterectomy using cine magnetic resonance imaging.

Blood flow in the cervical carotid bifurcation was investigated by cine magnetic resonance imaging. In patients without stenosis, a low-intensity stream was demonstrated from the beginning of the carotid bulb, which was more distinct in the systolic phase. In patients with stenotic carotid bifurcations, the low-intensity flow was also present but was more prominent than in the non-stenotic bifurcation. This low-intensity stream may be due to the change from steady to turbulent flow due to the geometric characteristics of the carotid bifurcation or atheromatous plaque, similar to the flow separation phenomenon in fluid dynamics because of the coincidence of location and flow pattern. After carotid endarterectomy, turbulent flow was seen at the proximal and distal ends of the endarterectomy. Close follow-up and administration of antiplatelet agents are necessary to prevent restenosis due to mural thrombosis induced by such turbulent flow.

Carotid Arteries↗
PubMed1993

Membrane lipid fluidity affects the nitroxide radical decay of 5-doxyl stearic acids in isolated rat hepatocytes.

We investigated the effect of membrane fluidity on the nitroxide radical decay rate of 5-doxyl stearic acid in spin-labeled rat hepatocytes. The half-time (t1/2) for the EPR signal decay of 5-doxyl stearic acids incorporated into the membranes of isolated rat hepatocytes was 12 min (mean value). When spin-labeled hepatocytes were separated into membrane and cytosol fractions, the t1/2 of the membrane fraction was prolonged by more than 2 hrs. However, when the cytosolic fraction was added to the membrane fraction, the radical decay reaction recovered (t1/2 was 27 min). Incubation of hepatocytes with a stream of 95% O2 at 37 degrees C for 2 hrs prolonged t1/2 by 106% and was associated with a 18% decrease in water-soluble antioxidant content. When the measurement temperature was changed from 24 degrees C to 37 degrees C, t1/2 was shortened with a decrease in the order parameter (S). The t1/2 and S in hepatocytes treated with phosphatidylcholine (PC) were reduced by 14% and 0.008, respectively. Conversely, after treatment with phosphatidylethanolamine (PE), PC+cholesterol and PE+cholesterol, t1/2 and S increased by 14% and 0.014, 20% and 0.018 and 29% and 0.040, respectively. These findings suggest that the nitroxide radical decay of 5-doxyl stearic acids incorporated into hepatocyte membranes is mediated by the antioxidants in the cytosol fraction, and that the nitroxide radical decay rate is affected not only by water-soluble antioxidant content but also by the membrane lipid fluidity of the hepatocytes.

Animals↗
PubMed1993

[Assessment of myocardial perfusion abnormalities in patients with apical hypertrophic cardiomyopathy using exercise 201Tl scintigraphy].

Regional myocardial perfusion abnormalities commonly occur during exercise in patients with hypertrophic cardiomyopathy (HCM). Exercise 201Tl myocardial scintigraphy has provided a noninvasive means of identifying myocardial perfusion abnormalities in patients with HCM. On the other hand, apical hypertrophic cardiomyopathy (APH) is reported as a subtype of HCM. Whether APH is essentially equal to HCM or not is controversial. To assess myocardial ischemia in patients with APH, we studied 28 patients with APH, with exercise 201Tl SPECT. Myocardial perfusion images were obtained immediately after submaximal exercise and again after a 3-hour delay. Regional perfusion defects during exercise were identified in 19 of the 28 patients (68%) with APH. Complete reversible defects were observed in 15 (79%) patients with APH. Although perfusion defects were present in all regions of the left ventricle in patients with HCM, they were present only in the apical region in patients with APH. Thus, reversible 201Tl perfusion abnormalities commonly occur during exercise in patients with APH as well as in patients with HCM.

Adult↗
PubMed1993

[Prevalence and distribution of Helicobacter pylori in the stomach of patients by upper gastrointestinal endoscopy].

The prevalence of H. pylori colonization in the antrum and body was examined in patients with gastritis, duodenal ulcer (DU) and gastric ulcer (GU). The total prevalence was 63.5%, 90.0% and 85.5%, respectively. In patients with gastritis and DU, the frequency was similar at both sites, while in GU patients H. pylori positivity was increased markedly in the body compared with the antrum. Furthermore, in patients with antral and angular ulcers, biopsy studies from 8 different sites showed that the H. pylori density score was significantly higher at the ulcer sites than at the non-ulcer sites. H. pylori infection is strongly implicated in the pathogenesis of gastritis and peptic ulceration.

Duodenal Ulcer↗
PubMed1993

[Assessment of reverse redistribution on exercise 201Tl myocardial SPECT in patients with hypertrophic cardiomyopathy].

Reverse redistribution is revealed on exercise 201Tl myocardial SPECT in some cases with hypertrophic cardiomyopathy. Ten patients with hypertrophic cardiomyopathy without coronary artery disease who showed reverse redistribution visually were studied. Reverse redistribution was evaluated by the early and delayed images of exercise 201Tl myocardial SPECT. Relation between reverse redistribution and distribution of left ventricular hypertrophy estimated by echocardiography and magnetic resonance imaging was investigated, and the mechanism of reverse redistribution was analyzed by referring to Bull's eye display of washout rate. Reverse redistribution was displayed in non-hypertrophic region and washout rate was normal in that region and low in hypertrophic region. In conclusion, in order to interpret reverse redistribution it is necessary to recognize hypertrophic region and to refer to washout rate.

Adult↗
PubMed1993

[Combined spinal and epidural analgesia for caesarean section].

We compared the combined spinal and thoracic epidural analgesia with 2% lidocaine for caesarean section, with spinal analgesia using 2% lidocaine, tetracaine or dibucaine, and also with lumbar epidural analgesia. The analgesia at high thoracic level could be achieved with combined spinal and epidural analgesia more easily than with others. The frequency of side effects with the combined spinal and epidural analgesia, such as hypotension, decrease of fetal heart rate and so on, was less than that with others. In conclusion, the combined spinal and thoracic epidural analgesia with 2% lidocaine is more useful for caesarean section, than the spinal analgesia or the lumbar epidural analgesia alone.

Anesthesia, Epidural↗
PubMed1993

[Chronic myelomonocytic leukemia and esophageal cancer developed in a renal allograft recipient].

A 46-year-old man treated with azathioprine (100-150 mg/day) and prednisolone (10mg/day) for 14 years after allogeneic renal transplantation, was admitted to our hospital in December, 1988 for the evaluation of leukocytosis. His leukocyte count was 32,700/microliters with 38% monocytes and 2% blasts. Chromosomal analysis of the bone marrow revealed 45, XY, -7. He was diagnosed as chronic myelomonocytic leukemia (CMML), and treated with low-dose Ara-C. Two months later, he progressed to overt acute leukemia, and he complained of difficulty in swallowing. Endoscopic examination revealed esophageal cancer. The patient died of respiratory failure on April 18, 1989. This case suggests that immunosuppressive agents might play an important role on the pathogenesis of CMML and esophageal cancer.

Azathioprine↗
PubMed1993

[Postoperative apnea in preterm infants after inguinal herniorrhaphy].

Preterm infants may become apneic during immediate postoperative period. We studied prospectively postoperative apneic attack in 167 preterm infants after inguinal herniorrhaphy with nitrous oxide-halothane anesthesia. Their mean gestational age was 30 +/- 3 weeks. The mean postnatal age at operation was 14 weeks. The post-conceptual age varied between 36 and 56 weeks. The mean birth weight was 1351 +/- 395 kg. Although many of them had a risk factor of postoperative apneic attack, i.e.a young post-conceptual age (less than 41 weeks), a light weight at operation (below 3000g), only one infant who had received emergency operation had an episode of apneic attack up to 2 postoperative days. For preventing postoperative apneic attack in preterm infants after inguinal hernia, we recommend the use of halothane anesthesia and the attention until a complete awakening.

Apnea↗
PubMed1992

A modified model of reversible middle cerebral artery embolization in rats without craniectomy.

A detailed description is given of a new model of reversible focal cerebral ischaemia in rats. A spherical embolus, attached to the end of an 8-0 surgical thread was injected into the middle cerebral artery (MCA) via the external and internal carotid arteries (ECA and ICA) and could be withdrawn by pulling the extravascular portion of the thread when reperfusion was to follow ischaemia. In contrast to similar techniques, the 8-0 thread did not block blood flow in either the common carotid artery (CCA) or the ICA during ischaemia and, as the CCA did not have to be ligated, flow could be restored via the ipsilateral CCA and ICA after the ischaemic period. Neurological deficit, mortality rate, tissue water content, regional pH, ATP and, in some experiments, electroencephalogram (EEG) and cerebral blood flow (CBF) were evaluated in ischaemia and after various length of reperfusion. The overall mortality rate was 21%; all these animals were lost in the first hours of recirculation. The water content of their brains differed significantly from those who survived 24 hours (81 and 77% respectively). A significant difference in CBF of the ipsi- and contralateral putamen was found immediately after embolization (a CBF decrease of 26 +/- 5 and 5 +/- 5 ml/100 g/min, respectively), and relative hyperperfusion (+23 +/- 27 ml/100 g/min) was observed in the ipsilateral putamen during reperfusion. EEG amplitude declined on both the affected and non-affected sides after embolization (to 54 +/- 8% and 71 +/- 6% of pre-ischaemic values) and remained decreased (66 +/- 8% of control) on the ipsilateral side after 1 hour of reperfusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗