Search PubMed⌕ Search

Biomedical subjects

S Ohashi

Publications and source records attributed to S Ohashi.

At least 37 records · Page 2Linked to original sources
PubMed2001

Fibrin monomer could be a useful predictor of pulmonary embolism after total hip arthroplasty: preliminary report.

We examined 17 total hip arthroplasty patients in order to develop a method for the predictive diagnosis of pulmonary embolism (PE) after joint arthroplasty. Scintigraphy revealed the presence of PE in 4 patients. Prothrombin time (PT), activated partial thromboplastin time (aPTT), antithrombin III (ATIII), and thrombin-AT III complex (TAT) did not show significant differences between patients with and without PE. D-dimer 7 days after surgery showed significant differences between patients with and without PE. Fibrin monomer (FM) increased sharply after surgery, and it was significantly different between the patients with and without PE immediately after surgery and 2 days after surgery. Our findings suggest the importance of FM in the predictive diagnosis of pulmonary embolism after total hip arthroplasty, and 40 microg/ml or higher levels with our measurement method could represent a high-risk condition.

Aged↗
PubMed2001

Cationic polymer-mediated genetic transduction into cultured human chondrosarcoma-derived HCS-2/8 cells.

The usefulness of three types of cationic polymer, i.e., degraded polyamidoamine (PAMAM) dendrimer (SuperFect Transfection Reagent; Oiagen), linear polyethylenimine (PEI; ExGen 500; Euromedex), and branched PEI in gene delivery into chondrocytes was examined comparatively. A plasmid vector containing the Escherichia coli LacZ (pSES.beta) was combined with one of the three cationic polymers at various molar ratios and the resultant complex (polyplex) was used to transduce a human chondrocyte-like cell line, HCS-2/8. Gene expression was evaluated by an O-nitrophenyl beta-D-galactopyranoside (ONPG) assay and by staining with 0.05% 5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside (X-gal; Nacalai Tesque). The ONPG assay showed that the highest delivery rate was achieved when 2microg of pSES.beta was combined with either 21 microg of dendrimer, 1.7microg of linear PEI, or 2.0microg of branched PEI. At the same DNA/polymer ratios, the proportions of X-gal-stained cells were also the highest (31.3 +/- 7.5%, 30.3 +/- 9.0%, and 8.3 +/- 3.1%, respectively). LacZ expression reached the highest level 3 days after the dendrimer-mediated transduction, and gradually declined, returning to the background level on day 14. Possible cytotoxicity was examined by trypan blue staining and phase contrast microscopic observations. Neither cytotoxicity nor morphological change was induced at the optimal dose of each polymer. The cationic polymers, particularly the degraded dendrimer and linear PEI, would be a useful nonviral vector for gene delivery to cells of chondrocytes.

Bone Neoplasms↗
PubMed2001

A vitamin D analog ameliorates glomerular injury on rat glomerulonephritis.

OCT (22-oxa-calcitriol), a vitamin D analog, has been reported to show strong inhibitory effects on mesangial cell proliferation in vitro. In the present study, we report a study of the effect of OCT on anti-thy-1 glomerulonephritis. Both OCT and 1,25(OH)(2)D(3) significantly inhibited mesangial cell proliferation, the degree of glomerulosclerosis, and albuminuria at day 8 compared to the disease control group. The OCT-treated group showed normal calcium levels but the 1,25(OH)(2)D(3)-treated group showed higher levels. The disease control group showed a marked increase of type I and type IV collagens, and alpha-smooth muscle actin (alpha-SMA) compared to the normal group. The treatment of OCT or 1,25(OH)(2)D(3) significantly reduced the expression of these proteins. The mRNA of the glomeruli of anti-thy-1 model expressed significantly higher levels of type I and type IV collagens, and alpha-SMA at day 8 compared to normal rats. Treatment with OCT or 1,25(OH)(2)D(3) inhibited the mRNA expressions of type I and type IV collagens, as well as that of alpha-SMA. These data demonstrate that OCT inhibits mesangial cell proliferation and extracellular matrix expansion with a low calcemic activity. Disease control rats showed significantly increased levels of transforming growth factor-beta1 protein in the glomeruli, but treatment with OCT or 1,25(OH)(2)D(3) markedly reduced this expression. The levels of mRNA in glomeruli were also consistent with these protein levels. Therefore, the suppressive effect of OCT may be mediated by inhibition of transforming growth factor-beta1. The present results suggest that OCT has potential for use in therapeutic strategy for the treatment of glomerulonephritis without inducing hypercalcemia.

Actins↗
PubMed2001

Highly efficient gene transfer into murine liver achieved by intravenous administration of naked Epstein-Barr virus (EBV)-based plasmid vectors.

Naked plasmid DNA (pDNA) injection could become an alternative procedure to viral and nonviral gene delivery systems. We have previously shown that Epstein-Barr virus (EBV)-based plasmid vectors containing the EBV nuclear antigen 1 (EBNA1) gene and the oriP sequence enable quite high and long-lasting expression in various in vitro and in vivo transfection systems. The EBV-based plasmids were intravenously injected into mice via their tail vein under high pressure. A large amount of the marker gene product was expressed in the liver; as much as 320 microg of luciferase was demonstrated per gram of liver at 8 to 24 h after a single injection with 10 microg of DNA. More than 70% of liver cells stained with X-gal when beta-gal gene was transferred. The expression level was significantly higher than that obtained by conventional pDNA lacking the EBNA1 gene and oriP. On day 35 after the transfection, the expression from the EBV-based plasmid was approximately 100-fold stronger than the conventional pDNA gene expression. Both the EBNA1 gene and oriP are a prerequisite for the augmentation of the transfection efficiency. These results suggest that the intravascular transfection with naked EBV-based plasmid may provide a quite efficient, simple and convenient means to transduce therapeutic genes in vivo into the liver.

Animals↗
PubMed2001

The influence of nitroglycerin and prostaglandin E1 on dynamic cerebral autoregulation in adult patients during propofol and fentanyl anaesthesia.

We investigated dynamic cerebral autoregulation in 24 normocapnic adult patients during propofol and fentanyl anaesthesia. Hypotension was induced, to a mean arterial pressure (MAP) of 60-65 mmHg, using nitroglycerin or prostaglandin E1. Time-averaged mean cerebral blood flow velocity in the right middle cerebral artery was measured continuously using transcranial Doppler sonography. Dynamic autoregulatory response was activated by a sudden decrease in MAP following release of bilateral thigh cuffs (thigh cuff test) and evaluated as a dynamic rate of autoregulation (dRoR in % x s(-1)). The cuff test was repeated to obtain two values of dRoR during baseline and during induced hypotension; the data were then averaged. The mean value of dRoR during baseline and during induced hypotension was 14.2 (2.9) and 14.2 (1.6) % x s(-1), respectively, in the nitroglycerin group, and 14.6 (2.6) and 14.4 (2.4) % x s(-1), in the prostaglandin E1 group. We were unable to demonstrate significant between- or within-group differences in dRoR. Thus, we conclude that nitroglycerin and prostaglandin E1 do not attenuate dynamic cerebral autoregulation.

Adult↗
PubMed2001

A case of inability to belch.

A 22-year-old man was unable to belch. He could sense intraesophageal gas, but had no chest pain. An upper gastrointestinal X-ray series and endoscopic examination showed no abnormalities. Esophageal manometry showed normal relaxation of both the upper and lower esophageal sphincters with primary peristalsis during deglutition. However, bolus injection of air into the middle esophagus failed to initiate the belch reflex.

Adult↗
PubMed2001

Naloxone improves arterial blood pressure and hypoxic ventilatory depression, but not survival, of rats during acute hypoxia.

OBJECTIVE: To investigate the effects of naloxone and morphine during acute hypoxia. DESIGN: Prospective, randomized animal study. SETTING: University laboratory. SUBJECTS: Twenty-eight adult male Sprague Dawley rats, weighing 300-350 g. INTERVENTIONS: The rats were implanted with a femoral catheter and subcutaneous electrodes for electrocardiogram recording and were randomly assigned to receive morphine (5 mg/kg), naloxone (5 mg and 10 mg/kg), or normal saline (control) (n = 7 in each). Fifteen minutes after intraperitoneal injection of the drug, each rat was exposed to hypoxic gas (5% oxygen, 95% N2) for 70 mins. Hypoxic survival time was measured. Mean arterial pressure (MAP), arterial pH, Paco2, Pao2, and base excess were measured before injection (baseline), 14 mins after injection (H0), and 6 mins (H1), 33 mins (H2), and 48 mins (H3) after exposure to hypoxia. MEASUREMENTS AND MAIN RESULTS: Hypoxic survival was similar between the naloxone 5 mg/kg and control groups (p = .183), significantly lower in the naloxone 10 mg/kg group (p < .01), and significantly higher in the morphine 5 mg/kg group (p < .05) compared with controls. MAP significantly decreased in all groups. However, at H2-H3, MAP was better preserved in both naloxone groups and was lower in the morphine group compared with controls. Paco2 was maintained higher at H0-H3 in the morphine group and lower at H2-H3 in both naloxone groups compared with controls. CONCLUSION: During acute hypoxia, naloxone preserves arterial blood pressure and attenuates hypoxic ventilatory depression by antagonizing endogenous opiates, but it does not improve hypoxic survival. In contrast, morphine, which enhances the action of endogenous opiates, does improve hypoxic survival. The acute hypoxic tolerance of morphine may be partly attributable to a depression of oxygen consumption, increased cerebral blood flow secondary to high Paco2, and protective actions mediated by delta-opioid receptors.

Acute Disease↗
PubMed2001

Development and prevention of advanced diabetic nephropathy in RAGE-overexpressing mice.

Vascular complications arising from multiple environmental and genetic factors are responsible for many of the disabilities and short life expectancy associated with diabetes mellitus. Here we provide the first direct in vivo evidence that interactions between advanced glycation end products (AGEs; nonenzymatically glycosylated protein derivatives formed during prolonged hyperglycemic exposure) and their receptor, RAGE, lead to diabetic vascular derangement. We created transgenic mice that overexpress human RAGE in vascular cells and crossbred them with another transgenic line that develops insulin-dependent diabetes shortly after birth. The resultant double transgenic mice exhibited increased hemoglobin A(1c) and serum AGE levels, as did the diabetic controls. The double transgenic mice demonstrated enlargement of the kidney, glomerular hypertrophy, increased albuminuria, mesangial expansion, advanced glomerulosclerosis, and increased serum creatinine compared with diabetic littermates lacking the RAGE transgene. To our knowledge, the development of this double transgenic mouse provides the first animal model that exhibits the renal changes seen in humans. Furthermore, the phenotypes of advanced diabetic nephropathy were prevented by administering an AGE inhibitor, (+/-)-2-isopropylidenehydrazono-4-oxo-thiazolidin-5-ylacetanilide (OPB-9195), thus establishing the AGE-RAGE system as a promising target for overcoming this aspect of diabetic pathogenesis.

Animals↗
PubMed2001

Pur alpha protein implicated in dendritic RNA transport interacts with ribosomes in neuronal cytoplasm.

We have previously reported that pur alpha, known to be a regulator of DNA replication and transcription, links neural BC1 RNA to microtubules via dendrite-targeting RNA motifs. Here we demonstrate the subcellular localization of pur proteins within the brain. Pur proteins were detected in neurons but not in glia. Immunohistochemical staining was prominent in perikarya and proximal dendrites and also extended into primary dendritic processes, but no significant signals were detected in the distal regions of dendrite. When homogenates of mouse brain were fractionated, pur alpha was most concentrated in the microsomal pellet. Consistently, pur alpha co-fractionated with free polysomes as well as with membrane-bound polysomes and the association with polysomes was mediated by binding ribosomal subunits. Levels of ribosomes with pur alpha progressively increased during postnatal development of the brain.

Animals↗
PubMed2001

Association of seropositivity for antibody to Chlamydia-specific lipopolysaccharide and coronary artery disease in Japanese men.

Recent studies suggest an association between Chlamydia pneumoniae infection and coronary artery disease (CAD). To examine this relationship in Japanese men, serum IgA and IgG antibodies to Chlamydia-specific lipopolysaccharide were measured by enzyme-linked immunosorbent assay in 507 patients with CAD and 200 age-matched controls. CAD patients were divided into (1) 269 patients with myocardial infarction (MI) and (2) 238 patients with chronic coronary heart disease (CCHD). Compared with the control group, the CAD group did not differ in the prevalences of both antibodies (IgA: 23.7 vs 18.0%, p=0.10; IgG: 52.7 vs 51.0%, p=0.6). The index of IgG antibody was not significantly different between CAD and control groups (median 1.19 vs 1.18, p=0.3), whereas the index of IgA antibody was significantly higher in CAD than control group (median 0.60 vs 0.46, p<0.0001). Compared with the control group, the MI group had a significantly higher prevalence of IgA antibody (28.6 vs 18.0%, p=0.007); however, there was no difference in the prevalence of IgG antibody (58.0 vs 51.0%, p=0.13). The CCHD group did not differ in the prevalences of both antibodies (IgA: 18.1 vs 18.0%, p=0.9; IgG: 45.6 vs 51.0%, p=0.2). After the adjustment for coronary risk factors, odds ratios (ORs) of seropositive antibodies for CAD were 1.59 [95% confidence interval (CI): 0.88-2.87, p=0.12] for IgA seropositivity and 0.92 (95%CI: 0.58-1.47, p=0.7) for IgG seropositivity in all cases. In the MI and control groups, ORs of seropositive antibodies for MI were 2.67 (95%CI: 1.32-5.38, p=0.007) for IgA seropositivity, and 1.36 (95%CI: 0.79-2.36, p=0.2) for IgG seropositivity. This study discovered that IgA antibody to Chlamydia was significantly associated with CAD, especially with MI, in Japanese Men and the findings suggest that chronic infection of Chlamydia may be linked to the pathogenesis of MI.

Aged↗
PubMed2001

NMR determination of the absolute configuration of a macrophomate synthase inhibitor by using an axial chiral reagent.

Macrophomate synthase catalyzes an extraordinary four-step transformation from oxalacetate and 2-pyrone to macrophomic acid by an intermolecular Diels-Alder reaction. The absolute configuration of the most potent macrophomate synthase inhibitor; (-)-2-carboxylmethyl-1-methoxybicyclo[2.2.2]oct-5-ene-2-carboxylic acid, was determined to be (1S, 2R, 4R) by using an axial chiral reagent.

Carboxylic Acids↗
PubMed2001

Evidence for involvement of central 5-HT(4) receptors in cholinergic function associated with cognitive processes: behavioral, electrophysiological, and neurochemical studies.

The possible involvement of 5-HT(4) receptors in cognitive function was investigated with a view toward modulating the cholinergic neuronal system. For this purpose, behavioral, electrophysiological, and neurochemical studies were performed in rats. The behavioral study, using a passive avoidance test, demonstrated that the 5-HT(4) receptor agonist SC 53116 (10 microg/rat i.c.v.) had an ameliorative effect on the muscarinic receptor antagonist scopolamine-induced (1 mg/kg i.p.) impairment of learning. The electrophysiological study showed that SC 53116 (1 and 10 microg/rat i.c.v.) enhanced the population spike amplitude in the hippocampal CA1 field evoked by Schaffer collateral stimulation. SC 53116 (10 microg/rat i.c.v.) also augmented the tetanus-induced long-term potentiation (LTP). This augmented LTP was blocked not only by the selective 5-HT(4) receptor antagonist GR 113808 (20 microg/rat i.c.v.) but also by scopolamine (1 mg/kg i.p.). These findings suggest that the functional interaction between the serotonergic system mediated via 5-HT(4) receptors and the cholinergic system associated with cognitive processes exists in vivo. This possibility was further strengthened by neurochemical study using in vivo microdialysis; local administration of SC 53116 (10 and 100 microM) concentration-dependently enhanced the extracellular levels of acetylcholine (ACh) in the hippocampus. SC 53116-induced (10 microM) facilitation of ACh release was prevented by coperfusion of GR 113808 (10 microM). Taken together, the present findings obtained by these different approaches indicate the possibility that the 5-HT(4) receptors are involved in cognitive impairment induced by the cholinergic neuronal system.

Acetylcholine↗
PubMed2001

Expression of transduced HSP70 gene protects chondrocytes from stress.

OBJECTIVE: To investigate the efficacy of adenovirus vector mediated transduction of heat shock protein 70 (HSP70) gene to human chondrocyte-like cell (HCS-2/8) against heat stress. METHODS: Two adenovirus vectors that contain wild-type (AxSHEwt) or mutant-type (AxSHEmt) HSP70 gene, and that are regulated by SRalpha promoter, were constructed. The mutant-type lacks the area that expresses stress durability. One of the 2 adenovirus vectors was added to the cultures of human chondrocyte-like cells (HCS-2/8). Heat stress (48 degrees C) was applied to the transduced cells for 2 h, and the efficacy of adenovirus vector mediated transduction of HSP70 gene against heat stress in the chondrocytes was investigated using alamar blue assay and MTT assay. RESULTS: Absorbance levels at 48 degrees C were 300.3 +/- 51.9 and 1.173 +/- 0.011 in the controls, 278.5 + 33.8 and 1.217 +/- 0.018 in the AxSHEmt transduced cells, and 349 +/- 14.7 and 1.371 +/- 0.033 in the AxSHEwt transduced cells. The level in the AxSHEwt transduced cells was significantly higher than in the other 2 groups (p < 0.05). With 37 degrees C treatment, no significant difference was observed. CONCLUSION: Chondrocytes to which HSP70 gene was transduced had a significantly higher metabolic activity and viability under heat stress.

Adenoviridae↗
PubMed2001

[Cerebral autoregulation during sevoflurane or isoflurane anesthesia: evaluation with transient hyperemic response].

We investigated dynamic cerebral autoregulation during N2O-O2/fentanyl anesthesia (baseline) plus 1.0 and 2.0 minimum alveolar anesthetic concentrations (MAC) of sevoflurane or isoflurane anesthesia in 14 patients undergoing non-neurosurgical operation. Cerebral blood flow velocity in the right middle cerebral artery (Vmca) was measured continuously using transcranial Doppler ultrasonography. At normocapnia, dynamic cerebral autoregulation was tested by transient hyperemic response (a response of Vmca after a brief compression of the ipsilateral common carotid artery). For quantitative comparisons, ratio of systolic Vmca before, to immediately after compression (THRR) was calculated. Values of THRR were 1.14 +/- 0.03 (mean +/- SD), 1.15 +/- 0.04, and 1.12 +/- 0.03 during baseline, 1.0, and 2.0 MAC sevoflurane anesthesia, respectively. THRR was not significantly different among the 3 conditions. In contrast, THRR values were 1.17 +/- 0.03, 1.07 +/- 0.02, and 1.01 +/- 0.01 during baseline, 1.0, and 2.0 MAC isoflurane anesthesia, respectively. THRR was significantly attenuated in a dose dependent manner during isoflurane anesthesia. These results indicate that dynamic cerebral autoregulation is preserved during 2.0 MAC sevoflurane anesthesia, but not during 1.0 MAC isoflurane anesthesia.

Adult↗
PubMed2001

[Prospective study of pulmonary embolism after total hip or knee arthroplasty].

We investigated the incidence of pulmonary embolism after total hip or knee arthroplasty. Arterial pO2 while the patient was breathing room air was measured at pre-operative day and 5 post-operative day using a Blood Gas Analyzer. Selection of patients for perfusion/ventilation scan during this study was dependent on the results of arterial blood gas determination that was more than 10 mmHg depression Of arterial pO2 level after surgery. More than depression of that was occurred in 11 patients (17.7%). Eight of them (72.7%) detected abnormalities (V/Q mismatch) in perfusion/ventilation scan, and we diagnosed them PE. More than 70% of PE was detected by only estimating the pre and post-operative arterial pO2. It was concluded that the estimation of arterial pO2 (pre and post-operation) was useful for the detection of PE, and combining estimation of arterial pO2 with the clinical feature evaluation method, low-invasive diagnosis and rapid treatment should be possible.

Aged↗
PubMed2000

Insertion with long target duplication: a mechanism for gene mobility suggested from comparison of two related bacterial genomes.

The complete genome sequences of two closely related organisms--two Helicobacter pylori strains--have recently become available. Comparison of these genomes at single base pair level has suggested the presence of a mechanism for bacterial gene mobility--insertion with long target duplications. This mechanism is formally similar to classical transposon insertion, but the duplication is much longer, often in the range of 100bp. Restriction and/or modification enzyme genes are often within or adjacent to the insertion. A similar process may have mediated insertion of the cag(+) pathogenicity island in H. pylori. A similar structure was identified in comparisons between Neisseria meningitidis and Neisseria gonorrhoeae genomes. We hypothesize that this mechanism, as well as two other types of polymorphism linked with restriction-modification genes (insertion accompanied by target deletion and a tripartite structure composed of substitution/inversion/deletion), have resulted from attack by restriction enzymes on the chromosome.

Base Sequence↗
PubMed2000

A clinicopathologic study of gastric mucosa-associated lymphoid tissue lymphoma.

BACKGROUND: It is still unclear which patients with gastric mucosa-associated lymphoid tissue (MALT) lymphoma will benefit from the eradication of Helicobacter pylori. METHODS: The authors studied a total of 34 patients. Twenty-three patients had primary gastric lymphoma and underwent gastric resection as initial treatment. Eleven patients with gastric MALT lymphoma who received antibiotics against H. pylori as initial treatment were also included. In all 34 patients, the presence of H. pylori, endoscopic findings, and pathologic features were evaluated. Immunohistochemical expression of Bcl-2, p53, and proliferating cell nuclear antigen (PCNA) was classified as follows: (-), no reactive cells; (+), scattered positive cells; (2+), nests of positive cells; (3+), diffuse positive cells. RESULTS: Patients with low grade MALT lymphoma (LG) tended to be positive for H. pylori (6 of 9), to localize within the submucosa (7 of 9), not to have lymph node involvement (7 of 8), and to have lower tumor stage compared with patients with high grade MALT components (HG). Bcl-2 protein was expressed with high frequency by LG (7 of 9). Strong expression of p 53 was more common in the HG tumors (4 of 14), and strong expression of PCNA showed a significant difference between LG (1 of 8) and HG patients (12 of 13). Investigation of the patients with long term follow-up (n = 4) revealed that LG remained superficial for a long time and showed gradual progression. Most of these tumors were Bcl-2+/p53-approximately+/-/ PCNA- approximately +. There were two patients whose superficial LG (sm/Bcl-2+/p53-/PCNA- approximately +) regressed after the disappearance of H. pylori. On the other hand, one patient developed ulcerated LG (sm/Bcl-2 /p53+/PCNA3+) after disappearance of H. pylori. The authors found complete regression of MALT lymphoma in 9 of 11 patients after H. pylori eradication. Initial tumors of these 9 patients were superficial/sm/n(-)/low grade/Bcl-2+approximately +/-/p53-approximately+ (n = 9), /PCNA-approximately+(n = 6), /PCNA 2+ (n = 3). Two local recurrence and one non-Hodgkin lymphoma in other sites were observed after initial therapy. CONCLUSIONS: Gastric MALT lymphoma with (H. pylori positive/superficial/sm/low grade/Bcl-2 +/p53- approximately +/PCNA- approximately +) pattern will disappear after a patient is cured of H. pylori infection.

Adult↗