Search PubMed⌕ Search

Biomedical subjects

T Shima

Publications and source records attributed to T Shima.

At least 73 records · Page 4Linked to original sources
PubMed1997

Hepatic damage influences the decay of nitroxide radicals in mice--an in vivo ESR study.

To determine the role of the liver in the elimination of free radicals from the body, the clearance rate (K) of nitroxide radicals (Tempol) at the hepatic domain was compared with that at the pelvic domain of live mice, using L-band ESR spectroscopy. The reduction of Tempol in biopsy specimens (liver tissue and femoral muscle) and blood obtained from Tempol-treated mice was also monitored using X-band ESR spectroscopy. Results indicated that the reduction of nitroxide radicals was delayed in both the liver and peripheral tissues when the liver was damaged. The decrease in both blood supply and reductants in the damaged liver might be involved in delaying the reduction in the whole body, because the liver can reduce the radicals supplied via the blood from the peripheral tissues, and the reductants such as reduced, glutathione in the peripheral tissues are supplied from the liver.

Animals↗
PubMed1997

[Perioperative risk factors and anesthetic management of patients for carotid endarterectomy].

Data from the records of 142 patients for carotid endarterectomy at Chugoku Rosai General Hospital between 1983 and 1995, were evaluated concerning perioperative risk factors and anesthetic management. As a preoperative anesthetic risk, the incidence of hypertension was the commonest (76%), and there was a significant incidence of ischemic heart disease (18%). Fentanyl and isoflurane have been used for anesthesia recently and the patients were closely observed and cared in the intensive care unit postoperatively. In order to prevent cerebral ischemia during the occlusion of the internal carotid artery, we measured somatosensory evoked potential as well as jugular venous oxygen saturation, and used near infrared spectophotometry. As a result, postoperative mortality and morbidity were 0% and 2%, respectively. The candidates for CEA have potentially high perioperative risks, and it is important to evaluate the coexisting diseases and to select proper anesthetic technic and monitors.

Adult↗
PubMed1997

[Postgadolinium MR angiography of normal intradural veins of the thoracolumbar spine].

To evaluate the normal intradural spinal veins, we used postgadolinium three-dimensional time-of-flight MR angiography (MRA) at 1.5T in 7 subjects. MR images and MR angiograms[32/6/1 (TR/TE/NEX)] were obtained after a bolus injection of Gd-DTPA (0.15-0.2 mmol/kg). We reconstructed images using an equipped function, so-called multiplanar reconstruction. The anterior median veins in 2 patients and the posterior median veins were shown in 2. The great medullary veins were demonstrated in 2. We successed in obtaining venous angiograms by postgadolinium MRA. Disseminated tumors and abnormal enhanced cauda equina are often indistinguishable from normal intradural veins. This study suggests that it is useful to know the MR angiographic features of normal intradural veins in order to evaluate enhanced intradural components.

Adult↗
PubMed1997

[Angiographical evaluation of extracranial carotid artery: comparison between Japanese and Hungarian].

We investigated the cervical level of carotid bifurcation, diameter of common carotid artery (CCA) and internal carotid artery (ICA) in 147 Japanese patients (150 arteries, range of age 31-79) and in 490 Hungarian patients (517 arteries, range of age 12-77). The cervical level of carotid bifurcation was determined by comparison with cervical vertebra. The carotid bifurcation of Japanese was most frequent at the lower part of 3rd cervical vertebra but in Hungarian the bifurcation was most frequent at the middle part of 4th cervical vertebra. Japanese carotid bifurcation was high-positioned compared with Hungarian. The mean CCA diameter in Japanese was 7.47 mm in male and 7.07 mm in female, in Hungarian 9.24 mm in male and 7.80 mm in female. The mean ICA diameter in Japanese was 4.96 mm in male and 4.83 mm in female, in Hungarian 8.56 mm in male and 7.66 mm in female. CCA and ICA diameter were larger in male than in female. The diameter of CCA had a significantly positive correlation with age (p < 0.002) but ICA had no similar correlation.

Adolescent↗
PubMed1996

Evidence of a direct action of taurine and calcium on biological membranes. A combined study of 31P-nuclear magnetic resonance and electron spin resonance.

To determine the actions of taurine and calcium on biological membranes, the effects of these compounds on the mobility of phospholipids of resealed and sonicated ghosts of human erythrocytes were investigated, using 31P-NMR spectroscopy. In addition, the effects of taurine and calcium on lipid fluidity were investigated by ESR spectroscopy, using a spin-labeling method with 5-doxyl stearic acid. The mobility of the membranes decreased following treatment with 10 mM taurine, but coadministration of 2.5 mM calcium blocked this effect. The fluidity of the membranes was not changed following treatment with 10 mM taurine, but decreased following coadministration of 2.5 mM calcium. These actions of taurine and calcium on the dynamics of biological membranes might explain, in part, the observation that most of the pharmacological effects of taurine on mammalian organs occur in the presence of calcium ions.

Calcium↗
PubMed1996

Helicobacter pylori infection in patients with gastric carcinoma in biopsy and surgical resection specimens.

BACKGROUND: The discrepancy between the high seropositivity for Helicobacter pylori (H. pylori) and the low diagnostic yield of H. pylori organism in gastric biopsies of patients with gastric carcinoma has yet to be clarified. The present study attempted to clarify this controversial point by performing a comparative evaluation between the detection rate of H. pylori in biopsy and in surgical specimens. METHODS: The presence of H. pylori in biopsy samples from 50 patients with gastric carcinoma and 50 age-matched controls was evaluated histologically. Six histologic sections were obtained from gastric noncancerous areas and the presence of H. pylori was evaluated in those H. pylori negative patients who underwent gastrectomy. RESULTS: H. pylori was positive in 35 of 50 controls (70%). In biopsy samples, H. pylori was detected in 29 of 37 patients (78.4%) with early gastric carcinoma, 7 of 13 (53.8%) with advanced carcinoma, 16 of 23 (69.6%) with intestinal type of gastric carcinoma, and 20 of 27 (74.1%) with diffuse type of carcinoma. Studies carried out in gastrectomy specimens increased the diagnostic yield of H. pylori to 33 (89.2%), 12 (92.3%), 19 (82.6%), and 26 (96.3%) in patients with early, advanced intestinal, and diffuse types of gastric carcinoma, respectively. Overall, H. pylori was positive in 36 biopsy specimens (72%) and 45 gastrectomy specimens (90%). Namely, the detection of H. pylori infection was significantly higher in patients with gastric carcinoma using gastrectomy specimens than in patients with gastric carcinoma using biopsy specimens only (P < 0.05). CONCLUSIONS: These results indicate that the actual prevalence of H. pylori in patients with gastric carcinoma is considerably higher than that previously reported.

Biopsy↗
PubMed1996

High plasma level of plasmin-alpha 2-plasmin inhibitor complex is predictor of poor prognosis in patients with lung cancer.

The occurrence of thrombotic complications is commonly associated with poor prognosis in patients with malignancy. However, the prognostic significance of the subclinical activation of the clotting system, frequently observed in cancer patients, is unknown. The purpose of the present study was to evaluate the value of the pre-thrombotic state for predicting survival of lung cancer patients. This investigation comprised 70 lung cancer patients without clinical or laboratory diagnosis of intravascular coagulation. There were 49 cases with non-small and 21 with small cell carcinomas. Samples taken in controls were available for comparison. The clotting system was assessed measuring thrombin-antithrombin III complex (TAT) and plasmin-alpha 2-plasmin inhibitor complex (PAP). The independent value of these clotting markers to predict survival was evaluated in relation with previously well-established prognostic factors for lung cancer patients. Plasma concentration of each parameter was significantly higher in cancer patients as compared to that of controls. The plasma level of PAP was a predictor of survival independently from the stage of disease, sex, age, histological type, performance status, tumor size and the presence of distant metastasis. Discriminant analysis of PAP plasma concentration identified 2 groups with significant difference in survival rate in all patients, cases in advanced stages of disease and in those with small and non-small cell lung cancer. The results of the present study showed prognostic significance of the subclinical activation of the clotting system, particularly of the fibrinolytic pathway, in lung cancer. Newly developed markers of fibrinolysis might be potentially applicable for predicting outcome in malignancy.

Adult↗
PubMed1996

A novel method for the assessment of autonomic neuropathy in type 2 diabetic patients: a comparative evaluation of 123I-MIBG myocardial scintigraphy and power spectral analysis of heart rate variability.

The correlation between the degree of sympathetic denervation measured through 123I-MIBG Myocardial Scintigraphy and Power Spectral Analysis of consecutive R-R records was investigated in order to evaluate their potential application for the assessment of myocardial autonomic neuropathy in patients with diabetes mellitus. This study comprised 42 patients with Type 2 diabetes. Low frequency (0.02-0.09 Hz) components of the power spectral density were measured as markers of sympathetic activity. The myocardial uptake of 123I-MIBG was measured by using the single photon emission computed tomography (SPECT) and the early and delayed images were recorded. Scoring from 0 to 3 of the 123I-MIBG uptake of various cardiac segments (7) was performed and the total uptake was calculated. The washout rate in the whole myocardium was determined. The values obtained in the group with diabetic autonomic neuropathy (DAN) without orthostatic hypotension (OH) were significantly lower as compared to those of the (DAN (-)) group in the delayed images. The washout rate of the OH (-) group was also significantly higher than the DAN (-) group. There was significant difference between the images and the washout rate of OH (+) and OH (-) groups. There was a significant correlation between Power Spectral Analysis and SPECT (early, delayed images, and washout rate). Of these, the delayed image showed the strongest correlation (r = 0.55, p < 0.01). Further, the QTc interval showed a significant inverse correlation with the delayed image (r = -0.44, p < 0.05). In conclusion, these results suggest that the cardiac 123I-MIBG scintigraphy could be a useful method for the assessment of the myocardial autonomic neuropathy in patients with diabetes mellitus.

3-Iodobenzylguanidine↗
PubMed1996

Histological changes in elastic components of soft palate scars after CO2 and contact Nd:YAG laser incisions in the dog as an experimental model.

Soft palate stiffening operations--often with CO2 or contact Nd:YAG lasers--have been used recently to treat patients with pronounced snoring. Differences in soft palate scars formed after CO2 and contact Nd:YAG laser incisions were studied in an animal model to determine which of these lasers produces a more rigid scar and consequently might be more effective for a soft palate stiffening operation. Six mongrel dogs were placed in each laser group, after which either the CO2 or Nd:YAG laser was used to make a 1.5-cm-long soft palate incision. The scars produced were then excised and studied histologically 4 weeks postoperatively. Special attention was paid to collagen density and elastin fibers in the scar tissue. After contact Nd:YAG laser incisions scar tissue was found to contain densely aligned collagen fibers and practically no elastin fibers. CO2 laser incisions produced significantly different scars: irregularly arranged collagen fibers with some elastin fibers also inside the scar tissue. Differences in the shapes of the scars and wound contractions were also found that were only seen after contact laser incisions. These findings suggest that the contact Nd:YAG laser might be more effective for soft palate stiffening operations.

Animals↗
PubMed1996

Ischemic colitis during interferon-alpha treatment for chronic active hepatitis C.

Between 1991 and 1994, at Hoshigaoka Koseinenkin Hospital, we treated 280 patients with chronic hepatitis C with interferon (IFN), and ischemic colitis occurred in two patients (0.7%) during the treatment. Melena appeared in case 1 in the 2nd month after the initiation of IFN-alpha treatment, and in case 2 in the 6th month. In both patients, longitudinal ulcerations in the descending colon were revealed by urgent colonoscopy, and these resolved within 2 weeks after discontinuation of the IFN treatment. It appears that ischemic colitis was associated with the IFN treatment, suggesting that attention should be paid to this possible complication.

Aged↗
PubMed1996

Protein C activation in NIDDM patients.

Enhanced activation of the clotting system has been recently implicated in the pathogenesis of vascular complications in patients with diabetes mellitus. Abnormalities of the anticoagulant system may constitute a potential trigger factor for the haemostatic activation observed in diabetic subjects. The current study aimed to evaluate anticoagulant activity in diabetic patients by assessing the plasma levels of activated protein C-protein C inhibitor complex; and by measuring the anticoagulant response to exogenous thrombomodulin. This study comprised 61 patients (34 men, 27 women) with non-insulin-dependent diabetes mellitus (NIDDM) of whom 22 showed microalbuminuria and 39 normoalbuminuria. Data obtained in 31 non-obese and non-diabetic subjects were available for comparison. The plasma levels of fibrinogen (p < 0.02), prothrombin fragment 1 + 2 (p < 0.05), fibrin monomer (p < 0.0001), protein C antigen (p < 0.005), total protein S antigen (p < 0.02), soluble thrombomodulin (p < 0.005) and soluble E-selectin (p < 0.005) were significantly higher in diabetic patients than in healthy subjects. The plasma level of activated protein C-protein C inhibitor complex (7.4 +/- 3.8 vs 3.0 +/- 0.4 pmol/l) was significantly higher (p < 0.0001) and the anticoagulant response to exogenous thrombomodulin (23.4 +/- 2.6 vs 35.3 +/- 3.0 ng/ml) was markedly lower (p = 0.005) in all diabetic patients than in healthy subjects. Cases with microalbuminuria presented low plasma levels of activated protein C-protein C inhibitor complex (5.5 +/- 0.6 vs 8.6 +/- 0.7 pmol/l, p < 0.05) and significantly decreased values of the anticoagulant response to exogenous thrombomodulin (16.5 +/- 2.9 vs 23.4 +/- 2.6%, p = 0.03) as compared to those with normoalbuminuria. The present study suggests that the hyper-coagulable state in NIDDM is associated with an increased activation of protein C but with a poor plasma reactivity to the anticoagulant effect of thrombomodulin.

Adult↗
PubMed1996

Interaction of neuromelanin and iron in substantia nigra and other areas of human brain.

Nine areas of the brain were studied by electron paramagnetic resonance spectroscopy and total reflection X-ray fluorescence spectroscopy to measure paramagnetic metal ions, free radicals (neuromelanin), and total metal content. We also determined the extent of accumulation of metal ions by melanins incubated in homogenates of a region of the brain (putamen). The electron paramagnetic resonance spectra of metal ions varied considerably among areas of the brain. There was no correlation between total content of particular metal ions (iron was especially pertinent) and the observed electron paramagnetic resonance spectra, except that the substantia nigra appeared more consistently to have a prominent g = 4 electron paramagnetic resonance signal characteristic of ferric iron in a rhombic state. Only the substantia nigra, and to a lesser extent the locus coeruleus, had a free radical signal consistent with that of neuromelanin. This signal was much more prominent in the unprocessed substantia nigra but when metal ions were removed (reducing the amount of suppression of the electron paramagnetic resonance signal of neuromelanin due to dipole-dipole broadening from nearby metal ions), the electron paramagnetic resonance spectrum of neuromelanin of the locus coeruleus increased much more than that of the substantia nigra. This suggests that the structure of the pigment may differ in these two regions. Incubating synthetic melanins with homogenates of putamen resulted in accumulation of metal ions on the melanins with the concentrations of the three metal ions, relative to their values in the putamen, increasing by factors of 20-30, 3-4, and 25-30, for iron, copper, and zinc, respectively. This suggests that the metal content of isolated neuromelanin may include metal ions which became bound to the neuromelanin during the isolation procedure.

Aged↗
PubMed1996

Identification of the sequences responsible for nuclear targeting of the V protein of human parainfluenza virus type 2.

In human parainfluenza virus type 2 (hPIV-2)-infected cells, anti-phosphoprotein (P)-specific monoclonal antibody (MAb) densely stained the perinuclear regions of infected cells throughout infection, indicating that the P protein was localized exclusively in the cell cytoplasm. By contrast, antigens recognized by MAbs directed against the P-V-common domain of hPIV-2 were located predominantly in the cytoplasm, but in some hPIV-2-infected cells they were also found in the nuclei, suggesting that a fraction of hPIV-2 V protein is localized there. hPIV-2 V protein expressed from a cDNA clone was localized in the nuclei of transfected cells. By using indirect immunofluorescence analyses, we examined the intracellular localization of various sequentially deleted V proteins, to determine the nuclear localization signals (NLS) of the V protein. Two noncontiguous regions in the V protein were required for nuclear localization and retention, since deletion of these regions [region I (aa 1-46) and region II (aa 175-196)] resulted in cytoplasmic localization. Both regions resulted in nuclear localization independently. A nucleoplasmin-like NLS was identified in region II but no consensus targeting sequence could be found in region I. When NP protein was co-expressed with V protein or the N-terminal fragment (aa 1-46) of V protein, a fraction of the NP protein was translocated into cell nuclei.

Amino Acid Sequence↗
PubMed1996

Enhanced engraftment of HTLV-I-infected human T cells in severe combined immunodeficiency mice by anti-asialo GM-1 antibody treatment.

The effects of anti-asialo GM-1 antibody (AAGM) treatment on the engraftment of human T-cell leukemia virus type I (HTLV-I)-infected human T cells in severe combined immunodeficiency (SCID) mice were studied. The frequency of tumor formation in an HTLV-I-transformed human T-cell line, MT-2 cells, at the site of inoculation was significantly higher in AAGM-treated than untreated mice (P<0.05): 16/18 (89%) and 16/26 (62%), respectively. The promotive effect of AAGM treatment on tumor development was marked in the early stage (less than 3 weeks), suggesting that the immediate reaction of natural killers to the inoculated cells may be important for the prevention of tumor development. The surface phenotypes and clonality of the tumor cells were the same as the MT-2 cells inoculated. Inoculation of peripheral blood mononuclear cells (PBMC) from one of the 4 adult T-cell leukemia/lymphoma (ATL) patients resulted in the development of tumors in AAGM-treated SCID mice. However, the surface phenotypes of the cells from these tumors were a mixture of B cells and T cells, suggesting that these tumors consisted of Epstein-Barr virus-transformed B cells and HTLV-I-transformed T cells. In addition, HTLV-I was detected by polymerase chain reaction in various organs of the mice inoculated with PBMC from the ATL patient and the asymptomatic carrier examined. These results suggest that elimination of natural killer function by AAGM treatment is important, although such treatment is not always necessary for the engraftment of HTLV-I-infected cells in SCID mice.

Animals↗
PubMed1996

High acid secretion may protect the gastric mucosa from injury caused by ammonia produced by Helicobacter pylori in duodenal ulcer patients.

The aim of the present study was to investigate the mechanism by which gastric atrophy does not tend to occur in patients with duodenal ulcer despite frequent Helicobacter pylori infection. This investigation was performed in 60 patients with duodenal ulcer and 63 age-matched gastritis patients. Endoscopic findings in the antrum and corpus were classified as normal, atrophic and superficial changes. Biopsy specimens were taken from the antrum and corpus. Ninety per cent of patients with duodenal ulcer and 63.5% of patients with gastritis had H. pylori infection (P < 0.01). The incidence of normal findings in duodenal patients was 30% in antral regions and 50% in the corpus (P < 0.05). Atrophic change was observed in 21.7% of patients in the antrum and 3.3% of patients in the corpus (P < 0.01). The grade of inflammation in duodenal ulcer specimens was significantly higher in the antrum than in the corpus (P < 0.01). H. pylori density was significantly higher in the antrum than in the corpus in ulcer patients (P < 0.01). No significant difference in endoscopic findings, H. pylori density or the grade of inflammation was found between the antrum and corpus in patients with gastritis. The mean intragastric ammonia concentration was 10.3 mg/dL in duodenal ulcer patients and 6.2 mg/dL in gastritis patients (P < 0.01). The mean pH was 3.5 and 4.6 in ulcer and gastritis specimens, respectively (P < 0.01). Our data suggest that gastric mucosa injury is less frequently associated with duodenal ulcers than with gastritis due to the low H. pylori density in the corpus and to the higher acid output that neutralizes the ammonia produced by H. pylori.

Adult↗
PubMed1996

Measurement of PO2 in liver using EPR oximetry.

With the use of India ink and lithium phthalocyanine (LiPc) as electron paramagnetic resonance (EPR) oximetry probes, the PO2 of the liver was investigated in mice. Because India ink was taken up by the Kupffer cells of the liver, the EPR signal of the India ink reflected the average PO2 in phagocytic vesicles of these cells. The mean value of PO2 in the Kupffer cells measured by India ink was 15.3 +/- 4.4 Torr in unanesthetized animals. LiPc was administered as a macroscopic crystal and therefore reflected the PO2 of the overall liver. The PO2 measured by LiPc was 23.4 +/- 4.4 Torr, which is consistent with the median value of 23.5 Torr reported previously with the use of an oxygen electrode. Anesthesia (injection of 60 mg/kg ip pentobarbital sodium) decreased the average PO2 in both Kupffer cells and the overall liver. The effects of perturbing the blood flow were studied by reversible blockage of the portal vein and hepatic artery in anesthetized mice; the PO2 in both Kupffer cells (measured with India ink) and in overall liver (measured with LiPc) decreased with obstruction of the blood flow and returned toward normal with reperfusion. These results indicate that the PO2 in different locations in the liver can be significantly different under both normal conditions and after perturbation by either anesthesia or ischemia. These results also demonstrate that EPR oximetry can provide sensitive measurements of PO2 in the liver in vivo under various conditions.

Anesthesia↗