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Biomedical subjects

S Ikeda

Publications and source records attributed to S Ikeda.

At least 361 records · Page 20Linked to original sources
PubMed1998

[Effects of L-threo-Dops on orthostatic hypotension in Parkinson's disease].

Effects of L-threo-Dops (Dops) administration on orthostatic hypotention were evaluated with changes in blood pressure by postural change (lying to standing position) and subjective symptoms in 15 patients of Parkinson's disease having symptoms of orthostatic hypotention. Orthostatic syncope had improved significantly (p < 0.01) after 2 and 4 weeks of administration with maintenance dose of 460 mg/day of Dops in average. In the standing-up (Schellong) test, decrease in blood pressure levels by a postural change, both with systolic and diastolic blood pressure, was significantly smaller at 3, 5 and 10 minutes after standing after 4 weeks of drug administration. Decrease in the blood pressure level immediately after standing-up improved by 10.2 +/- 4.0 for systolic and 6.5 +/- 1.8 for diastolic (mmHg, mean +/- SE) (p < 0.01). The group that showed improvement in orthostatic syncope had a significant improvement in decline in blood pressure by standing after administration of Dops, while the group without any change in severity of syncope did not show significant improvement in orthostatic hypotention.

Aged↗
PubMed1998

Marked attenuation of mitral regurgitation by stent implantation: a patient with unstable angina.

A 69-year-old woman was admitted because of increase of chest pain and dyspnea. Systolic murmur of Levine III/VI was heard. Electrocardiography showed ST depression caused by ischemia. Echocardiography revealed severe mitral regurgitation (MR) and inferoposterior hypokinetic wall motion. Left ventriculography revealed the presence of MR (II/IV). Coronary angiography showed severe organic stenosis of the right coronary artery. Based on these findings, the diagnosis was severe papillary muscle dysfunction caused by unstable angina. The lesion of the right coronary artery was successfully stented with a Palmaz-Schatz stent. During balloon inflation, the v wave of the pulmonary capillary pressure curve was greatly elevated. After the stent implantation, ST depression was normalized and MR improved dramatically. Therefore, we suppose that acute MR was induced by temporary papillary muscle dysfunction, and could be relieved with coronary angioplasty.

Aged↗
PubMed1998

[A pulmonary tumorlet with caseous granuloma associated with atypical mycobacterium].

We encountered a case of pulmonary tumorlet with caseous granuloma associated with atypical mycobacterium. A 73-year-old woman was admitted to the hospital because a chest x-ray film showed enlargement of an abnormal shadow in the middle lobe of the right lung. Primary lung cancer was suspected and right middle lobectomy was performed. Acid-fast bacilli (Gaffky 1) were found in a caseous lesion and examination of intraoperatively obtained frozen specimens showed caseous granulomas. The bacilli were later identified as Mycobacterium avium complex. The permanent specimen showed a minute lesion consisting of small clusters of epithelial cells resembling carcinoid tumor in contact with granulomatous tissue. Histopathological examination revealed argyrophilia on Grimelius stain and immunoreactivity to chromogranin-A in the clusters of epithelial cells. Although these results are consistent with small cell carcinoma or peripheral carcinoid tumor, pulmonary tumorlet was diagnosed because of the lesion's small and minimal cytologic atypia, and because of chronic pulmonary damage around the lesion. Pulmonary tumorlets are minute, usually microscopic, tumor-like lesions mostly found in damaged lung tissue obtained at autopsy or during surgery. Morphological diagnosis is sometimes very difficult, but recently these lesions have been regarded as hyperplastic lesions arising in pulmonary neuroendocrine cells (Kultschitzky cells) and caused by chronic pulmonary damage, such as hypoxia and inflammation. Pulmonary tumorlets must be considered in the differential diagnosis of minute lesions suspected to be small cell carcinoma or peripheral carcinoid tumor.

Aged↗
PubMed1997

Peripheral nerves regenerated in familial amyloid polyneuropathy after liver transplantation.

BACKGROUND: Liver transplantation holds promise as a treatment for familial amyloid polyneuropathy. OBJECTIVE: To determine whether peripheral nerves regenerate in patients with familial amyloid polyneuropathy after liver transplantation. DESIGN: Case report. SETTING: University hospital in Matsumoto, Japan. PATIENT: A 34 year-old-women with familial amyloid polyneuropathy who had liver transplantation and showed marked clinical improvement 3 years after surgery. MEASUREMENTS: Histopathologic examination and morphometric analysis of biopsy specimens taken from sural nerves. RESULTS: Diffuse fiber loss and amyloid deposits were seen in a biopsy specimen of the left sural nerve obtained before liver transplantation (total number of myelinated fibers, 1326/mm2 of the endoneurial area). In the biopsy specimen of the right sural nerve, which was obtained 3 years after transplantation, amyloid deposits remained but the number of myelinated fibers was markedly increased (total number of myelinated fibers, 4740/mm2). CONCLUSION: Peripheral nerves regenerated in a patient with familial amyloid polyneuropathy after liver transplantation.

Adult↗
PubMed1997

Class Ia antiarrhythmic drug cibenzoline: a new approach to the medical treatment of hypertrophic obstructive cardiomyopathy.

BACKGROUND: The class Ia antiarrhythmic drug disopyramide relieves the outflow tract obstruction of hypertrophic obstructive cardiomyopathy (HOCM). Disopyramide, however, has several adverse effects, such as dysuria and thirst, resulting from its anticholinergic activity. A new class Ia antiarrhythmic drug, cibenzoline, has little anticholinergic activity. The aim of this study is to elucidate whether cibenzoline attenuates left ventricular pressure gradient (LVPG) in patients with HOCM. METHODS AND RESULTS: Ten patients with HOCM (mean age, 59+/-12 years) participated in this study. LVPG and left ventricular functions were measured before and 2 hours after administration of a single oral dose of 150 or 200 mg cibenzoline. LVPG decreased from 123+/-60 to 39+/-33 mm Hg (P=.0026). The E/A ratio in transmitral Doppler flow increased from 1.20+/-0.84 to 2.00+/-1.72 (P=.029). Isovolumic relaxation time increased from 73+/-16 to 101+/-23 ms (P=.0026). Left ventricular diastolic dimension remained unchanged, but left ventricular systolic dimension enlarged significantly, from 21.6+/-2.4 to 26.2+/-3.3 mm (P=.0004). Fractional shortening decreased from 47.6+/-6.1% to 34.6+/-8.8% (P=.0007). Left ventricular ejection time index decreased significantly, and preejection period index increased in all the patients. Decreased LVPG remained maintained even in the long-term treatment with cibenzoline. Conclusions These results indicate that cibenzoline can markedly attenuate LVPG in patients with HOCM. A decrease in myocardial contractility seems to be closely related to a marked decrease in LVPG.

Aged↗
PubMed1997

Expansion of intermediate T cell receptor cells expressing interleukin-2 receptor alpha- beta+, CD8alpha+ beta+, and lymphocyte function-associated antigen-1+ in the liver in association with intrahepatic islet xenograft rejection from rat to mouse: prevention of rejection with anti-interleukin-2 receptor beta monoclonal antibody treatment.

BACKGROUND: The precise mechanisms involved in islet xenograft rejection remain unknown. The purpose of the present study was to determine cellular mechanisms responsible for islet xenograft rejection in the liver to facilitate finding a procedure for prevention of immune rejection. METHODS: Hepatic mononuclear cells (MNC) as well as splenocytes, peripheral blood MNC, and thymocytes from streptozotocin-induced diabetic mice (BALB/c) rejecting the intrahepatic rat (Lewis) islet xenografts were isolated and examined by two-color FACS analysis. RESULTS: The characteristic finding of the hepatic MNC from the mice rejecting islet xenografts compared with mice receiving isografts was a significant increase in the yield as well as in the percentage of the cells expressing CD3+ interleukin-2 receptor (IL-2R) alpha- beta+, CD3+ CD8alpha+ beta+, and T cell receptor (TCR) alphabeta+ lymphocyte function-associated antigen-1+. The expression of CD3 and TCR alphabeta of these T cells was found to be of intermediate intensity (TCR(int) cells). The expansion of these TCR(int) cells occurred predominantly in the liver. There was no significant difference in the cells expressing CD3+ IL-2R alpha+, CD3+ CD4+, CD3+ TCRgammadelta+, CD3- IL-2Rbeta+ (natural killer cells), and B220+ (B cells). In vivo administration of anti-IL-2Rbeta monoclonal antibody directed to the expanded cells produced a prevention of rejection. CONCLUSIONS: These findings suggest that islet xenograft rejection in the liver from rat to mouse is an event for which the TCR(int) cells are responsible.

Animals↗
PubMed1997

A metalloproteinase inhibitor prevents lethal acute graft-versus-host disease in mice.

Tumor necrosis factor (TNF) and Fas ligand (FasL) have been implicated in the pathogenesis of graft-versus-host disease (GVHD), which is a major complication after allogeneic bone marrow transplantation. We examined here the ameliorating effect of a metalloproteinase inhibitor (KB-R7785) that inhibits TNF-alpha and FasL release in a lethal acute GVHD model in mice. Administration of KB-R7785 into (BALB/c x C57BL/6) F1 that received C57BL/6 spleen cells markedly reduced the mortality and weight loss in association with minimal signs of GVHD pathology in the liver, intestine, and hematopoietic tissues. The ameliorating effect of KB-R7785 was superior to that of anti-TNF-alpha antibody. Our results suggest that KB-R7785 could be a potent therapeutic agent for GVHD.

Animals↗
PubMed1997

Function of P-glycoprotein expressed in placenta and mole.

We examined the expression of P-glycoprotein in human placentas and hydatidiform moles. Trophoblasts in all the examined placentas and moles expressed P-glycoprotein, and the size of the P-glycoprotein was smaller than that in multidrug-resistant human epidermoid carcinoma KB cells. The P-glycoprotein in the placenta and mole was photolabeled with [3H]azidopine, and [3H]vincristine was transported in an ATP-dependent manner into membrane vesicles prepared from trophoblasts that expressed P-glycoprotein. These findings indicate that P-glycoprotein expressed in trophoblasts has a drug binding site(s) and the ability to transport vincristine, suggesting that P-glycoprotein in the placenta protects the fetus from xenobiotics and confers drug resistance on moles.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1997

Oxidized low density lipoprotein caused CNS neuron cell death.

Death induced by oxidized low density lipoproteins (oxLDL) to embryonic CNS neuronal and neuroblastoma cells was investigated. Cell damage and viability were evaluated by LDH leakage and the MTT method, respectively. Dose- and time-dependent degeneration of neurons occurred after oxLDL (1-100 microg/ml) treatment but was absent after native low density lipoproteins (LDL). This degeneration was mediated, in part, by apoptosis because increased TUNEL and Hoechst dye-positive staining was observed. These effects occurred in the absence of microglia. However, DNA degradation was not detected. The cytotoxicity was attenuated by pre-treatment with antioxidants. These results suggest that oxidation by oxLDL may be important in neurocytotoxicity in the brain.

Animals↗
PubMed1997

Action of mitochondrial endonuclease G on DNA damaged by L-ascorbic acid, peplomycin, and cis-diamminedichloroplatinum (II).

Mitochondrial DNA (mtDNA) suffers extensive damage from the environment, however, the enzymes involved in the repair of mtDNA are still unknown. Here, we partially purified mitochondrial endonuclease G (Endo G) from the bovine heart, and examined the action of Endo G on damaged DNA. Treatment of DNA with L-ascorbic acid or peplomycin, that introduces single-strand breaks through active oxygen radicals, greatly enhanced the susceptibility to nucleolytic attacks from Endo G. The enzyme cleaved at or near sites where single-strand breaks were present in the opposite strand. Cisplatin-mediated DNA damage, which causes intrastrand crosslinks between adjacent guanine residues, also facilitated Endo G digestion, indicating that the enzyme can recognize local distortions in the duplex DNA introduced by adducts. These nucleolytic properties of Endo G in vitro suggest its possible involvement in the maintenance of mtDNA by eliminating defective genomes from the multicopy pool.

Animals↗
PubMed1997

An aquaporin-like gene required for the Brassica self-incompatibility response.

Self-incompatibility in Brassica refers to the rejection of self-related pollen and is mediated by a receptor protein kinase localized to the plasma membrane of the stigma epidermis in the flower. The recessive mutation mod eliminates self-incompatibility in the stigma. In mod mutants, self-compatibility was shown to be associated with the absence of transcripts encoded by an aquaporin-related gene. This observation suggests that a water channel is required for the self-incompatibility response of Brassica, which is consistent with the concept that regulation of water transfer from the stigma to pollen is a checkpoint in the early events of pollination in the crucifer family.

Amino Acid Sequence↗
PubMed1997

Bilirubin oxidation provoked by endotoxin treatment is suppressed by feeding ascorbic acid in a rat mutant unable to synthesize ascorbic acid.

We examined the possibility that bilirubin oxidation is provoked in vivo by using scurvy-prone ODS-od/od rats treated with endotoxin (lipopolysaccharide). Recently, bilirubin oxidative metabolites were isolated from human urine and named biotripyrrin-a and biotripyrrin-b. In ODS-od/od rats fed an ascorbic-acid-free diet, the concentration of bilirubin metabolites in urine was increased 7.0-fold at 3 h after injection of lipopolysaccharide and 4.4-fold at 10 h compared to the control rats injected with saline. The dietary supplement of ascorbic acid, the physiological antioxidant, suppressed the increase in bilirubin metabolites in urine after lipopolysaccharide injection: concentrations of biotripyrrin-a and biotripyrrin-b in urine collected 6.5-10 h after the injection were lower in rats fed an ascorbic-acid-supplemented diet than in rats fed an ascorbic-acid-free diet. Moreover, feeding of ascorbic acid suppressed the hepatic mRNA level of heme oxygenase-1, the rate-limiting enzyme of bilirubin biosynthesis, in rats injected with lipopolysaccharide. These findings indicate that bilirubin oxidation is markedly stimulated in lipopolysaccharide-treated rats and suggest that bilirubin and ascorbic acid have physiologically protective effects against oxidative stress.

Animals↗
PubMed1997

Nitric oxide inhibition decreases neutrophil adhesion at the inflammatory site, while increasing adhesion in remote organs in peritonitis.

Nitric oxide (NO) is a regulator of leukocyte adhesion in the microcirculation. This study was designed to examine the effects of a NO synthase inhibitor on neutrophil adhesion in the peritoneum, lung, liver, and kidney in a rat peritonitis model using a fluorescence microscopic method. Sprague-Dawley rats were given normal saline (control) or N omega-nitro-L-arginine methyl ester (L-NAME) at dosages of 10 mg/kg (N10) or 100 mg/kg (N100) (n = 66) intraperitoneally. One hour after pretreatment fluorescein-labeled neutrophils were infused without bacterial challenge (0 hr). Other rats received an injection of 10(7) Escherichia coli into the peritoneal cavity 1 hr after pretreatment. Labeled neutrophils were infused 1 and 5 hr after bacterial challenge. Just 2 min after neutrophil injection, blood samples were obtained and the animals were killed. Five peritoneal samples (omentum, mesentery, parietal peritoneum, colon, and ileum), both lungs, the liver, and the right kidney were harvested for counting of labeled neutrophils under epifluorescent microscopy. Combined plasma nitrite/nitrate levels were determined. In another set of rats (n = 36), an arterial catheter was inserted after L-NAME treatment and bacterial challenge. At 0, 1, 5, and 12 hr after challenge, blood pressure, heart rate, and arterial blood gas data were measured. One hour after E. coli challenge, the number of neutrophils in the peritoneum was significantly lower in both L-NAME-treated groups than in the control group. In contrast, the number of labeled neutrophils in the lungs was significantly higher in the N100 group than in the control group. Neutrophil accumulation in the lungs and peritoneum at 0 and 5 hr and in the liver and kidney at 0, 1, and 5 hr did not differ among groups, nor did combined plasma nitrite/nitrate levels. L-NAME treatment had no influence on either hemodynamic or blood gas data. In conclusion, administration of L-NAME increases neutrophil adhesion in the lung, while decreasing that in the peritoneum. NO plays an important role in neutrophil adhesion at the inflammatory site, as well as in remote organs, during peritonitis. NO inhibition may be detrimental, due to neutrophil sequestration, in this peritonitis model.

Animals↗
PubMed1997

Influences of type and duration of antimicrobial prophylaxis on an outbreak of methicillin-resistant Staphylococcus aureus and on the incidence of wound infection.

OBJECTIVE: To clarify how antibiotic prophylaxis influenced an outbreak of methicillin-resistant Staphylococcus aureus (MRSA) and postoperative infection. DESIGN: Retrospective review. SETTING: University-affiliated teaching hospital. PATIENTS: All patients (n=1824) undergoing subtotal esophagectomy, gastrectomy, or colorectal surgery during the period 1982 through 1995. MAIN OUTCOME MEASURES: Type, timing, and duration of prophylactic antibiotics. Postoperative infection by the Centers for Disease Control and Prevention definition and the organisms isolated. RESULTS: Third-generation cephalosporins were frequently administered for prophylaxis during the period 1982 through 1990. The rate of isolates of MRSA from the infected site increased, peaking in 1988 to 1990. Since 1991 to 1992, along with a marked decrease in third-generation cephalosporin use, the rates of MRSA isolated have declined dramatically. The timing of administration changed from postoperative to intraoperative. Although the duration was gradually decreased, coverage was still provided until about the fifth postoperative day, even during 1993 to 1995. Prolonged coverage did not reduce the rate of superficial incisional or organ/space surgical site infection or that of pneumonia. CONCLUSIONS: Overuse of third-generation cephalosporins for long periods caused an MRSA outbreak. Long-term prophylaxis did not lower infection rates. The briefest possible prophylaxis with first- or second-generation cephalosporins should be used in general surgery.

Antibiotic Prophylaxis↗
PubMed1997

Plasma levels of amyloid beta proteins Abeta1-40 and Abeta1-42(43) are elevated in Down's syndrome.

To investigate the effect of the overexpression of beta-amyloid precursor protein (APP) on the production of two major amyloid beta protein (Abeta) species, Abeta40 and Abeta42(43), we measured amounts of Abeta1-40 and Abeta1-42(43) in the plasma from 44 patients with Down's syndrome (DS) (age, 19-61 years) and 66 age-matched normal controls using enzyme-linked immunosorbent assays. Plasma concentrations of both Abeta1-40 and Abeta1-42(43) were increased about 3-fold and 2-fold, respectively, in DS patients compared with normal controls. Especially, the increases in plasma Abeta1-40 in DS patients were statistically higher than the 1.5-fold increase one might predict based on the gene dose of APP in DS. These findings showed that both Abeta1-40 and Abeta1-42(43) are increased in plasma in DS patients, the former more than the latter, suggesting that overexpression of APP and/or other genes may have different effects on the production of these two Abeta species in DS.

Adult↗