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Biomedical subjects

T Shima

Publications and source records attributed to T Shima.

At least 163 records · Page 9Linked to original sources
PubMed1990

Pathophysiological studies in the rat cerebral embolization model: measurement of epidural pressure and evaluation of tissue pH and ATP.

A rat embolization model was produced by occlusion of the main cerebral artery with a silicone cylinder embolus. Intracranial pressure was monitored by changes in epidural pressure (EDP), which was recorded by our designed flaccid microballoon. EDP changes could be divided into the two types: the first was moderate elevation, less than 20 mm Hg and the second was prominent, more than 20 mm Hg. Brain tissue pH on the embolized side showed heterogeneous changes composed of acidotic and alkalotic areas. Alkalotic change was frequently seen at the deep cerebrum which might be the result of plasma exudation due to disruption of blood-brain barrier (BBB). The degree of the EDP elevation was positively correlated with the extension of alkalotic area. Energy metabolism was also mainly disturbed in the deep cerebrum, but did not completely correspond to the pH change of the area. These results would indicate that embolization of the main cerebral artery could induce severe ischaemic insult on the deep cerebrum with massive brain swelling due to an early disruption of BBB.

Adenosine Triphosphate↗
PubMed1990

Calcium-associated cytoprotective effect of taurine on the calcium and oxygen paradoxes in isolated rat hepatocytes.

Our study was designed to determine the calcium and oxygen paradoxes in isolated rat hepatocytes, and to evaluate the cytoprotective effects of taurine on hepatocytes during oxygenation, hypoxia, and on these paradoxes. The calcium and oxygen paradoxes were clearly revealed in isolated rat hepatocytes. As the formation of the superoxide radical was accelerated by the hyperbaric conditions and the calcium ions, drugs such as superoxide dismutase and a calcium channel blocking agent (verapamil), prevented these paradoxes. Taurine decreased the oxygenation-induced lipid peroxidation of hepatocytes, and prevented the hypoxia-induced hepatocyte death in a calcium-containing medium, but not in a calcium-free medium. Taurine also protected the hepatocytes from injuries associated with the calcium and oxygen paradoxes due to the inhibition of sudden calcium influx into the hepatocytes.

Animals↗
PubMed1990

[Experience of carotid endarterectomy].

The clinical course of 45 patients treated by carotid endarterectomy over the past 5 years is described with emphasis on the following three points: 1) Diagnostic methods, namely digital subtraction angiography (DSA) and B-mode Doppler imaging technique; 2) surgical procedure using an improved shunt tube and surgical instruments; and 3) monitoring before and during surgery. All operations were conducted using a shunt. Morbidity and mortality rates were both 0%. Postoperative transient hemiparesis lasting for 6 hours was recognized in only four cases. The total percentage of correct diagnoses using intravenous DSA compared with conventional angiography was approximately 80%. The accuracy of the non-invasive B-mode Doppler technique in measuring the degree of constriction compared with conventional angiography was 84%. The shunt was made of silicone tubing and was based on a tube 30 cm in length and 3.5 mm in diameter which was a T-shaped loop. Different sized bulbs were fixed to each end of the tube to prevent extravascular deviation. Modified bulldog clamps and Sugita clips were used for fixation in the vessel. Regional cerebral blood flow (rCBF) measurement and electroencephalography (EEG) under contralateral Matas procedure were conducted before surgery, and cross circulation during short-term occlusion of the common carotid artery was evaluated. The emergence or increase of delta waves in EEG during occlusion was observed in six cases. The rCBF of the affected middle cerebral artery territory in these patients was lower than that in patients with no increase of delta waves. Furthermore, the mean stump pressure during surgery in cases with preoperative EEG changes was 40 mmHg and that in cases without changes was 63 mmHg; these values were significantly different.(ABSTRACT TRUNCATED AT 250 WORDS)

Carotid Artery Thrombosis↗
PubMed1990

[A comparative study of UFT enteric-coated granules with UFT capsules on the occurrence of side effects in patients with head and neck cancers--a special attention to the upper gastrointestinal tract disorders].

A comparative study on the occurrence of gastrointestinal side effects between UFT enteric-coated granules (UE) and UFT capsules (UC) was made by crossover method in 50 patients with head and neck cancer who were treated by these drugs as a surgical and/or radiation adjuvant chemotherapy. UE was significantly low in the occurrence of upper gastrointestinal side effects; remarkably low in such side effects as nausea and vomiting, in particular. On the other hand, there was little difference between UE and UC in the occurrence of such side effects as diarrhea, stomatitis, dry mouth and hematotoxic signs. The present result suggests that UE is clinically useful for treating the patients with cancer, with less occurrence of gastrointestinal side effects.

Adult↗
PubMed1990

[Brainstem infarcts presented medial longitudinal fasciculus (MLF) syndrome and cerebellar ataxia--report of three cases].

Vascular disorders of the brainstem manifest characteristic neurologic symptoms according to their localization. The medial longitudinal fasciculus (MLF) lies in the paramedian portion of the upper brainstem tegmentum, and the lesion in this fasciculus shows specific abnormality of the eye movement pattern which is known as the MLF syndrome. Although the MLF syndrome was reported frequently to be accompanied by varieties of other neurologic deficits according to the lesion extending into the adjacent structures in the brainstem, the combination of MLF syndrome and cerebellar ataxia has attracted less attention of neurologists. Recently we experienced three cases of cerebellar ataxia arisen simultaneously with MLF syndrome. Magnetic resonance imaging (MRI) tomography or X-ray computed tomography visualized lacunar lesion(s) in the upper brainstem tegmentum in all of three cases. It was obvious that the lesion included the MLF and caused the MLF syndrome in these cases. It was speculated that ventro-caudal extension of the lesion involved the decussation of the superior cerebellar peduncle, and was responsible for the association of cerebellar ataxia with MLF syndrome. According to the recent discussion about the feeding arteries in the brainstem, we decided that the damage of the paramedian branches diverging from the basilar tip resulted in the lacunar lesion(s). The development of diagnostic procedures especially MRI enables the diagnosis of the vascular disorders in the brainstem with considerable accuracy.

Aged↗
PubMed1990

[Hemodynamic studies on the vertebral artery system during the vertebral arterial surgery].

Few hemodynamic studies on the vertebral artery system in the human can be seen. The authors measured the vertebral arterial blood flow (VAF) with an electromagnetic flow meter in 45 patients who obtained vertebral arterial surgeries. The patients showing vertebrobasilar insufficiency such as vertigo and drop attack had serious kinking and stenosis at the first portion of the vertebral artery. The effects of induced hypotension by trimethaphan camsilate, induced hypertension by phenylephrine, cervical epidural anesthesia and induced hypertension under epidural anesthesia on the VAF were investigated. During the control state, mean systemic arterial blood pressure (SABP), mean VAF were 97 mmHg and 54 ml/min, respectively. The effects of varied SPBP were analyzed by (delta mean VAF/mean VAF)/(delta mean SABP/mean SABP), (delta V/delta S). The delta mean VAF and delta mean SABP indicated varied mean values of VAF and SABP, respectively. Mean SABP was varied significantly by about 25% in each method. The delta V/delta S in induced hypotension, induced hypertension, epidural anesthesia and induced hypertension under epidural anesthesia were -0.05, 0.07, 0.90 and 0.61, respectively, on the average. Induced hypotension by epidural anesthesia and induced hypertension under epidural anesthesia presented significant changes in mean VAF.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure↗
PubMed1990

[Changes in arterial oxygen tension during and after enflurane or halothane anesthesia as well as epidural analgesia].

Recovery from inhalation anesthesia is often marked by the occurrence of postoperative hypoxemia. In this study, we compared the effects of enflurane or halothane anesthesia and epidural analgesia on arterial oxygen tension during and after the operation in 60 ASA physical status 1-2 patients who underwent cholecystectomy. Anesthesia was induced with thiopental and maintained with 66% N2O and -enflurane (1.5%), -halothane (1%), or -epidural lidocaine (1% solution, 17.5 ml) in oxygen. Blood gas analysis was done before and 10, 30, 60 min after induction. PaO2 was measured on 1st and 3rd postoperative days in all patients breathing air spontaneously. PaO2 decreased during operation in all three groups of anesthesia. PaO2 values on first postoperative day were significantly lower than those before operation, and PaO2 value in enflurane group (PaO2 = 67 +/- 1 mmHg) was significantly lower than that in halothane group (PaO2 = 72 +/- 2 mmHg, P less than 0.05).

Adult↗
PubMed1990

Basement membrane-related and type III procollagen-related antigens in serum of patients with chronic viral liver disease.

To assess the significance of serum basement membrane- and type III procollagen-related antigens in reflecting the degree of liver fibrosis, we measured radioimmunologically the concentrations of 7S collagen, laminin fragment P1, and the aminoterminal propeptide of type III procollagen (P-III-P) in serum from 48 patients with chronic viral liver disease: chronic persistent hepatitis (9), chronic active hepatitis (13), chronic active hepatitis with lobular disorganization (17), and liver cirrhosis (9). Concentrations of 7S collagen, laminin P1, and P-III-P in serum were increased in respectively 92%, 69%, and 77% of the patients with both chronic active hepatitis with lobular disorganization and liver cirrhosis. Concentrations of 7S collagen and laminin P1 in serum correlated well (r = 0.65, P less than 0.001, and r = 0.55, P less than 0.001, respectively) with the histological grade of liver fibrosis, whereas P-III-P correlated only weakly (r = 0.33, P less than 0.05). Evidently, measurement of serum 7S collagen is a reliable noninvasive test for detection of fibrosis in chronic viral liver disease.

Adult↗
PubMed1990

[Tissue pH and energy metabolism in cerebral embolization model of rat].

Changes in brain tissue pH, ATP and NADH contents in the cerebral embolization model of Wistar rat were investigated by bioluminescence method. Under light anesthesia, main trunk of cerebral artery was embolized with a silicone cylinder (500 microns in diameter and 1 mm in length) through the cervical internal carotid artery. Rat brain was frozen in situ at 1 or 3 hours after embolization. In some rats Evans blue was injected into the peritoneal cavity 30 minutes before freezing. Caudate putamen and cortex were often acidotic but thalamus, hypothalamus, and hippocampus were composed of both acidotic and alkalotic area. Exudation of Evans blue was frequently detected in the alkalotic area. ATP was decreased partially in the acidotic area. In the alkalotic area ATP was decreased to mild to severe degree. Decreased ATP region in the acidotic area showed increased NADH content, whereas in the alkalotic area NADH was diffusely decreased. From these results, alkalosis may be induced by cerebral edema due to plasma exudation. The decrease of ATP and increase of NADH in the acidotic area may demonstrate the disturbance of oxidative phosphorylation under anaerobic glycolysis, and the decrease of ATP and decrease of NADH in the alkalotic area may demonstrate impairment of glycolysis mainly due to brain edema.

Acute Disease↗
PubMed1990

[Impaired cerebral circulation and the effect of glycerol infusion in the acute stage of hypertensive intracerebral hematoma].

The purpose of the present study was to clarify the mechanism of reduction in cerebral blood flow (CBF) in the acute stage of hypertensive intracerebral hematoma and the effect of glycerol infusion on the reduced CBF. We examined 55 cases. Thirty-eight cases showed putaminal hematoma and 17 presented thalamic hematoma. The range of consciousness was from alert to stupor. CBF was measured by single photon emission CT with Xe-133 inhalation within five days after the onset of the hemorrhage. A CBF map was obtained at a slice 5 cm above the OM-line and mean CBF of the affected and non-affected hemispheres was calculated. In 20 of 55 cases, 500 ml of glycerol was intravenously infused for 60 minutes and thereafter CBF was measured again. Epidural pressure was also recorded at the affected frontal area during glycerol infusion in three of the 20 cases. CBF reduced more profoundly in the area around the hematoma on the CBF map. Mean CBF of the affected hemisphere was negatively correlated with the volume of hematoma by a quadratic regression. After glycerol infusion, 13 of 20 cases showed a significant increase in mean CBF of the affected hemisphere, while the other seven cases showed no increase. Mean CBF increased with a higher percentage in cases with ventricular hemorrhage than without ventricular hemorrhage. In three cases where epidural pressure was measured during glycerol infusion, mean CBF increased and epidural pressure decreased. The increase in mean CBF was proportional to a rise in perfusion pressure calculated as pressure difference between mean systemic arterial pressure and mean epidural pressure, indicating impaired autoregulation in these cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1990

[A case of subdural effusion secondary to dural metastasis of prostatic cancer: case report].

The authors reported a case of subdural effusion secondary to dural metastasis of prostatic cancer. A 61-year-old man was referred for headache, vomiting and gait disturbance. He had undergone hormonal therapy for prostatic cancer. He showed a mild left hemiparesis and anemia without bleeding. CT-scan disclosed a multilobular crescent shaped low density area in the right hemisphere. Under the diagnosis of chronic subdural hematoma, burr hole irrigation therapy was performed. Xanthochromic fluid was evacuated from the subdural space, in which no tumor cells were shown to exist. CT-scan on the 21st day disclosed a low density area, which was diagnosed as recurrent chronic subdural effusion. Therefore, craniotomy was performed to evacuate the subdural fluid and to explore the dura mater. Removal of the red hemorrhagic tumor at the dura mater and the fluid was performed. The patient died of heart failure in the 16th month despite complete recovery after the second operation. Histopathological examination of the tumor revealed adenocarcinoma at the outer part of the dura mater and the adjacent skull bone, where capillaries were embolized with tumor cells. However, no tumor cells were found in the subdural fluid. The authors could find in the literature 30 cases of subdural hematoma or effusion secondary to dural metastasis of carcinoma. The pathogenesis of the subdural hematoma in this case might be due to circulatory disturbance at the dura mater brought about by the invasion of the tumor or tumor cells emboli in the capillaries.

Adenocarcinoma↗