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Biomedical subjects

T Sakurai

Publications and source records attributed to T Sakurai.

At least 361 records · Page 20Linked to original sources
PubMed1995

Release of superoxide radicals by mouse macrophages stimulated by oxidative modification of glycated low density lipoproteins.

Diabetic patients have high levels of glycated LDL. Although glycated LDLs are implicated in the development of atherosclerosis in such patients, convincing data are lacking. We observed release of superoxide radicals (O2-) from mouse resident peritoneal macrophages stimulated by an oxidized/glycated LDL by using a highly sensitive and specific chemiluminescence method. Oxidized/glycated LDL was achieved by an addition of low concentration of Fe3+ to glycated LDL. Macrophages took up an appreciable amount of the glycated LDL oxidized by iron, leading to the development of foam cells, while they did not take up untreated glycated LDL or the native LDL. These observations clearly indicate that the oxidized/glycated LDL reacts well with macrophages. Since an oxidation of glycated LDL may occur in vivo, the oxidized/glycated LDL might play an important role in atherogenesis.

Adenosine Diphosphate↗
PubMed1995

Effect of soluble fungal (1-->3)-beta-D-glucan obtained from Sclerotinia sclerotiorum on alveolar macrophage activation.

In this study, we examined the effect of systemic administration of SSG, a soluble highly branched (1-->3)-beta-D-glucan obtained from a fungus Sclerotinia sclerotiorum IFO 9395, on pulmonary immune responses in mice. SSG (10 mg/kg) administered intravenously (i.v.) rapidly leaked into the alveolar space and enhanced several functions of alveolar macrophages (AMs), such as phagocytic activity, lysosomal enzyme activity, active oxygen secretion and cytokine production, on day 1 post-administration. However, kinetic changes of influx of SSG into alveoli and AM activation after SSG treatment were different. The enhanced AM functions decreased to control value on day 2 when SSG still existed at the alveolar space. Additionally, a high dose (500 micrograms/ml) of SSG was needed to activate AMs in vitro. These data imply that the stimulation by SSG alone is not effective on AM activation. SSG administered i.v. also augmented interferon gamma (IFN gamma) mRNA expression in the lung tissue, and the kinetic change of the expression was similar to that of AM activation. Additionally, a synergistic effect of SSG and IFN gamma was observed on AM activation in vitro. It may be possible that IFN gamma produced by pulmonary T cells is one of the important factors for AM activation in vivo by SSG injection. Furthermore, SSG administered i.v. enhanced candidacidal activity and cytolytic activity against pulmonary metastatic Lewis lung carcinoma (3LL) cells of AMs, and inhibited significantly the experimental pulmonary metastasis of 3LL cells. These observations are very useful for the clinical application of SSG as a biological response modifier (BRM).

Animals↗
PubMed1995

Genotyping of hepatitis C virus by a simple ELISA method.

BACKGROUND: Hepatitis C virus (HCV) has been classified into five distinct types by nucleotide sequence analysis of the genome. The correlation between genotypes of HCV and sensitivity to treatment or prognosis is still controversial. OBJECTIVES: We tried to establish a simple antibody assay to determine the HCV serotype instead of genotype determined by PCR or nucleotide sequence. STUDY DESIGN: We made an enzyme-linked immunosorbent assay (ELISA) system by using synthetic oligopeptides of NS4 regions of types 1 (CH) and 2 (KN) HCV, and examined sera of various stages of hepatitis C patients. RESULTS: Among 13 HCV RNA-positive sera, serotyping was consistent with genotyping. Four sera of type 1 and 7 sera of type 2 were positive to anti-CH and anti-KN antibodies, respectively. Two sera of patients mixedly infected with type 1 and 2 HCV were positive to both antibodies. The number of type 1 and 2 in patients with chronic hepatitis, liver cirrhosis and hepatocellular carcinoma was 27 and 18, 28 and 15, and 46 and 12 respectively. CONCLUSIONS: Our result suggests that this simple ELISA method is useful for typing of HCV, and there is no significant relationship between HCV type and liver failure.

Journal Article↗
PubMed1995

Infrainguinal arterial reconstruction in end-stage renal disease.

A total of 14 infrainguinal revascularizations in 11 patients with end-stage renal disease resulting from diabetes mellitus were reviewed. Indications for surgery comprised gangrene or non-healing ulcerations in eight patients (11 limbs), ischaemic rest pain in two (two limbs) and disabling claudication in one (one limb). No graft failures occurred during the period of observation. There were two immediate postoperative deaths, one amputation, and four persistent non-healing foot ulcers. The remaining four patients showed improvement. Six deaths occurred, including two perioperative deaths. Four patients with non-healing ulcers died within 1 year and 10 months after revascularization, but their deaths were not associated with the foot ulcers. The cumulative patient survival rate was 42% at 1 year. Infrainguinal revascularization in patients with end-stage renal disease caused by diabetes mellitus is feasible when meticulous preoperative assessment and careful perioperative management are employed to minimize operative risk.

Aged↗
PubMed1995

Prevention of vascular graft infection by sisomicin incorporated into fibrin glue.

To examine the efficacy of sisomicin (SISO) incorporated into fibrin glue (FG) for the prevention of graft infection in animal models, the susceptibility to infection of Dacron grafts (control) and SISO-FG Dacron grafts following the inoculation of Staphylococcus aureus or S. epidermidis was compared. The results showed that SISO-FG Dacron grafts displayed resistance to graft infection.

Animals↗
PubMed1995

An immunopharmacological study of the biphasic allergic skin reaction in mice.

Biphasic skin reactions, with peaks at 1 and 24 h after epicutaneous challenge with antigen (immediate phase response: IPR and late phase response: LPR, respectively), were induced in ddY, ICR, Balb/c and Balb/c-nu/nu mice passively sensitized with monoclonal IgE antibody 24 h before. In WBB6F1-W/Wv mice, which lack mast cells, only the LPR was observed. The IPR was characterized by a rapid increase in capillary permeability and the LPR by skin thickening with significant infiltration of eosinophils and other inflammatory cells in Balb/c mice. Histamine H1 receptor antagonists, including diphenhydramine and homochlorcyclizine, and the allergic histamine release inhibitors, tranilast and amlexanox, clearly inhibited the IPR, but not the LPR. Prednisolone and dexamethasone, however, inhibited both. Prednisolone also inhibited the LPR in WBB6F1-W/Wv mice. These results indicate that IgE antibody-dependent biphasic skin reactions consist of a mast cell- and histamine-dependent IPR and a mast cell-independent LPR.

Animals↗
PubMed1995

Effect of fluoride on the activities of the Na+/glucose cotransporter and Na+/K(+)-ATPase in brush border and basolateral membranes of rat kidney (in vitro and in vivo).

In this study, renal Na+/K(+)-ATPase activity was demonstrated to be strongly suppressed prior to the glucosuria caused by a fluoride dose (NaF 35 mg/kg, i.p.), and the 50% suppression of the enzyme activity was almost at the same dose of NaF, about 30 mg/kg, i.p. to rats. In the rats, renal Na+/glucose cotransporter activity in brush border membranes was not affected by in vivo NaF, whereas the renal Na+/K(+)-ATPase in basolateral membranes showed a dip in activity 3 h after NaF treatment of the whole animal. Moreover, it was suggested from experiments with inhibitors of calphostin C and KT5720 that protein kinase C, but not protein kinase A, may play an important role in the suppression of Na+/K(+)-ATPase following the administration of fluoride to rats. Na+/glucose cotransporter was fairly insensitive to NaF, being competitively inhibited with a Ki of about 100 mM, whereas Na+/K(+)-ATPase was much more sensitive, with a Ki of about 2 mM. From these results, the elevation of urinary glucose excretion after a single dose of fluoride was deduced to be due to suppression of the renal Na+/K(+)-ATPase activity by a direct and/or secondary action of fluoride, rather than of the corresponding Na+/glucose cotransporter activity.

Animals↗
PubMed1995

Effect of levofloxacin-albumin Dacron graft on graft infection.

The susceptibility of Dacron grafts to infection is compared with Dacron grafts applied with levofloxacin-bonded albumin (LVFX-ALB) following the inoculation of 10(7) cells Staphylococcus aureus in rats. Staphylococcus epidermidis was inoculated in the same manner. While the control grafts were infected at the time of removal, the LVFX-ALB Dacron grafts resisted infection, thus demonstrating their effectiveness.

Animals↗
PubMed1995

Comparison of the characteristics of human gingival fibroblasts and periodontal ligament cells.

To elucidate the characteristics of human periodontal ligament cells, we compared these cells with gingival fibroblasts isolated from the periodontal tissues of female human subjects. Human periodontal ligament (HPDL) cells had a sharper spindle shape and exhibited a higher growth rate than human gingival fibroblasts (HGF). HPDL cells had a high level of alkaline phosphatase (ALPase) activity, whereas HGF had a low level of such activity. Northern blot analysis demonstrated that HPDL cells produced ALPase mRNA. Decorin and biglycan mRNA were detected in both HPDL cells and HGF, whereas osteocalcin and bone sialoprotein mRNA was not detected in either cells. Both HPDL cells and HGF responded to prostaglandin E2 (PGE2) and isoproterenol, and produced cyclic AMP (cAMP), but did not respond to human 1-34 parathyroid hormone (PTH). Intracellular Ca2+ ([Ca2+]i) was measured in HPDL cells and HGF, using Fura 2-AM. Bradykinin (BK) and histamine (HIS), which are major chemical mediators, caused a transient rise of [Ca2+]i in the presence of extracellular Ca2+. In HGF, but not HPDL cells, HIS induced a biphasic transient peak in [Ca2+]i. BK and HIS increased PGE2 release in both HPDL cells and HGF. However, HGF released a larger amount of PGE2 than HPDL cells. These results demonstrate that HPDL cells have quite different characteristics from HGF. HPDL cells proliferate at a higher rate than HGF, show higher levels of cAMP production and greater ALPase activity, and respond in a different fashion to chemical mediators (BK and HIS) compared with HGF.

Alkaline Phosphatase↗
PubMed1995

Immunochemical identification and subcellular distribution of the alpha 1A subunits of brain calcium channels.

A site-directed anti-peptide antibody (anti-CNA1) directed against the alpha 1 subunit of class A calcium channels (alpha 1A) recognized a protein of approximately 190-200 kDa in immunoblot and immunoprecipitation analyses of rat brain glycoproteins. Calcium channels recognized by anti-CNA1 were distributed throughout the brain with a high concentration in the cerebellum. Calcium channels having alpha 1A subunits were concentrated in presynaptic terminals making synapses on cell bodies and on dendritic shafts and spines of many classes of neurons and were especially prominent in the synapses of the parallel fibers of cerebellar granule cells on Purkinje neurons where their localization in presynaptic terminals was confirmed by double labeling with the synaptic membrane protein syntaxin or the microinjected postsynaptic marker Neurobiotin. They were present in lower density in the surface membrane of dendrites of most major classes of neurons. There was substantial labeling of Purkinje cell bodies, but less intense staining of the cell bodies of hippocampal pyramidal neurons, layer V pyramidal neurons in the dorsal cortex, and most other classes of neurons in the forebrain and cerebellum. Scattered cell bodies elsewhere in the brain were labeled at low levels. These results define a unique pattern of localization of class A calcium channels in the cell bodies, dendrites, and presynaptic terminals of most central neurons. Compared to class B N-type calcium channels, class A calcium channels are concentrated in a larger number of presynaptic nerve terminals implying a more prominent role in neurotransmitter release at many central synapses.

Animals↗
PubMed1995

[Two hepatocellular carcinoma patients with biloma after transarterial embolization with lipiodol (Lip-TAE) leading to occlusion of portal vein].

We presented two patients with post-Lip-TAE biloma resulting in portal occlusion, and reviewed 20 previous studies including our cases to investigate their clinical characteristics. Case 1. A 31-year-old woman suffered from an HCC located at the S8 segment, and had a superselective embolization of feeding arteries using 3 ml of Lip, 300 mg of CBDCA, and 40 mg of Epi-Adriamycin (Epi-ADM). Eleven weeks later, CT showed multiple cystic lesions, and the percutaneous transhepatic drainages of the lesions were established. At 21 weeks after Lip-TAE, we found occlusion of the right branch of portal vein on CT, but she recovered from this condition, and was discharged 1 year later. Case 2. A 62-year-old man was diagnosed as HCC located at S7-6 segments, and was infused with 3 ml of Lip, 150 mg of CBDCA, and 30 mg of Epi-ADM through a right hepatic artery. Ten weeks later, CT showed a cystic lesion in the S7-8 segments, occlusion of the right anterior segmental branch of the portal vein, and the same drainage was also established. Unfortunately, he died of liver failure 18 weeks later. In the literature, biloma after Lip-TAE occurred at 71.2 mean days, ranging from 7 to 180 days, a with remarkable increase in biliary tree-associated enzymes. Seven (35%) of 20 patients died of liver failure or sepsis during 3 weeks and 1 year, and 3 (60%) of 5 patients accompanied by occlusion of a certain portal branch frequently died. We consider that these patients need intensive care and should be under long follow-up.

Adult↗
PubMed1995

Bone marrow stromal cells produce and respond to activin A: interactions with basic fibroblast growth factor and platelet-derived growth factor.

Activin A, a homodimer of the beta A-chain, regulates hematopoiesis. We recently reported that murine bone marrow (BM) stromal cells, ST2 and MC3T3-G2/PA6, produce activin A [16]. Basic fibroblast growth factor (bFGF) and platelet-derived growth factor (PDGF), potent mitogens of BM stromal cells, induced a rapid increase in beta A-chain mRNA levels and activin secretion in these cells. Cycloheximide (CHX) did not inhibit the increases in beta A-chain mRNA levels, suggesting that these growth factors directly stimulate beta A-chain gene expression. Furthermore, activin A stimulated mitogenesis in ST2 cells, by itself and with bFGF and PDGF. Consistent with this observation, we detected mRNAs of activin A receptors in the murine stromal cells. These findings suggest that BM stromal cells, stimulated by bFGF and PDGF, produce activin A, which may stimulate stromal cells themselves in concert with these peptide growth factors.

Activin Receptors↗
PubMed1995

[An analyzing system for fluorescein angiography of retinal blood flow using a high speed, high sensitivity camera].

We constructed a speedy and sensitive fundus camera system, and developed a new method to analyze retinal blood flow in rabbits and monkeys. The system is composed of a fluorescein fundus camera (TRC-50X, Topcon), a relay lens, an image intensifier (Ektapro-intensified-imager, Kodak), a digital recorder (Ektapro-EM, Kodak), an S-VHS analogue recorder, a picture analyzer (IMAGEnet, Topcon), and a CRT (cathode-ray tube) monitor. The speed of retinal blood flow in rabbits is calculated by measuring the time and distance between two points of an advancing illumined fluorescein dye front in a vessel. The speed in monkeys is obtained by analysis using an autocorrelative function, instead of the method used with rabbits, because of background fluorescein noise and vessel tortuousity.

Animals↗
PubMed1995

[Predictable factors in healing of gastric ulcer, comparative analysis of local morphologic factor of gastric ulcer and suppression of intragastric pH].

Predictable factors in healing of 48 patients with gastric ulcer by PPI or H2-RA on 4 and 8 weeks of treatment were investigated. We evaluated the following factors such as patient's profile, local morphologic factors of gastric ulcer and suppression rate of 24 hr intragastric pH between healed and unhealed patients using single and multiple variable analysis. Results obtained from multiple variable analysis, the significant and independent factors of intractable gastric ulcers on the 4th week of treatment were ulcer size in over 20 mm and solitary ulcer. On the contrary, those of 8th week of treatment were shortage of holding time of intragastric pH over pH4 (less than 16.7 hrs) during treatment, the site of ulcer at lesser curvature of gastric angle and the shape of ulceration which showed mucosal overhanging. Considering with single and multiple variable analysis, we concluded that, in early phase, local shapes of the ulceration were important predictors in the healing of gastric ulcer, and the after that, the inhibition of intragastric acidity were significant factors in healing process of gastric ulcer.

Female↗
PubMed1995

[Significance of proliferative breast lesions around breast cancers].

To clarify the relationships between benign proliferative diseases and cancers of the breast, 44 cases treated with breast conserving surgeries were analyzed histopathologically. Intraductal hyperplasia, sclerosing adenosis and adenosis were more frequently seen in cancerous than non-cancerous breasts, with a statistically significant difference. Additionally, histologies of some intraductal spread in carcinomas were identical to those of atypical hyperplasias. Further studies should be undertaken, and definitions of atypical hyperplasia, especially in cancerous breasts, should be critically redefined.

Breast↗
PubMed1995

[Sudden death among 1,000 patients with myocardial infarction: incidence and contributory factors. KYSMI Study Group].

Clinical indicators and the incidence of sudden death among 1,000 consecutive patients (816 males and 184 females) with myocardial infarction were investigated between 1983 and 1987 after coronary arteriography. Twenty-four patients died suddenly during a study period of 3.3 +/- 2.0 yrs. The yearly incidence of sudden death calculated by the Kaplan-Meier method was 0.7%, nearly half of the incidence of cardiac death (1.5%/yr). Univariate analysis demonstrated statistically significant differences in the number of cases with coronary thrombolysis in the acute phase, degree of coronary artery stenosis, the frequency and degree of congestive heart failure and angina in the acute and chronic phase, the presence of serious post-infarction arrhythmia, ejection fraction, recurrent myocardial infarction, and administration of digitalis and diuretics. between the sudden-death group and the cardiac and other patient groups. There was also a tendency to higher frequency of history of diabetes mellitus, presence of acute mitral regurgitation, nitrates and nicorandil treatment, and coronary artery bypass graft in the sudden-death group. Multivariate analysis revealed that digitalis and nitrates treatment and left anterior descending artery involvement were major contributing factors. Re-infarction, left ventricular ejection fraction, and nicorandil therapy were not significant and minor contributing factors. The incidence of sudden death increased with digitalis therapy (Odds' ratio of 9.59), and left anterior descending artery disease, and decreased with nitrates (0.34).

Adult↗