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Biomedical subjects

K Ohta

Publications and source records attributed to K Ohta.

At least 37 records · Page 2Linked to original sources
PubMed2003

Highly polysialylated neural cell adhesion molecule (PSA-NCAM) positive cells are increased and change localization in rat hippocampus by exposure to repeated kindled seizures.

The highly polysialylated neural cell adhesion molecule (PSA-NCAM) is involved in migration of neural stem cells as well as in neural plasticity. Immunoreactive PSA-NCAM expression was examined in rats with repeated exposure to amygdaloid kindled generalized seizures (GS). The number of PSA-NCAM positive cells in the bilateral dentate gyrus (DG) increased significantly from GS. Although the total number of positive cells was not significantly different between animals with 3 times GS (3 GS) and 30 times GS (30 GS), in the latter group a greater number of positive cells was observed in the outer granule cell layer (GCL) and a marked extension of immunopositive dendrites to the molecular layer. These observations indicate that increased migration of newly generated cells as well as plastic changes of preexisting neural cells occur in response to recurrent GS. This may contribute to an abnormal reconstruction of the synaptic network in the hippocampus and, thus, epileptogenicity from kindling.

Animals↗
PubMed2003

Changes of free cholesterol and neutral lipids after transient focal brain ischemia in rats.

We investigated temporal and spatial changes of free cholesterol (FC) and neutral lipids (NLs) after brain ischemia with filipin complex staining to detect mainly FC and Nile Red staining for NLs such as cholesteryl ester (CE) and triacylglyceride (TAG). Filipin stainining decreased during 1 to 7 d and lost at 21 d after transient middle cerebral artery (MCA) occlusion in the ischemic core, but did not change in the penumbra. Nile Red positive droplets reached the maximum at 7 d after transient MCA occlusion (MCAO) and gradually decreased in the core, while the peak time delayed in the penumbra. Most Nile Red positive droplets were double positive for ED1 in the core, and were localized within GFAP positive cells in the penumbra. The present study suggests that changes of FC and NLs are different temporally and spatially between the ischemic core and the penumbra in relation to degenerative and regenerative neural processes following brain ischemia. Macrophages and astrocytes are presumed to play important roles in lipid metabolism for neural reorganization of the ischemic brain injury in the ischemic core and the penumbra, respectively.

Animals↗
PubMed2003

Dissociative increase of oligodendrocyte progenitor cells between young and aged rats after transient cerebral ischemia.

Oligodendrocyte progenitor cells (OPCs) mature to oligodendrocyte and remyelinate axons. OPCs express neuron-glial antigen 2 (NG2) chondroitin sulfate proteoglycan. We stained NG2 to investigate the effect of aging on the OPCs after cerebral ischemia. NG2 positive cells were examined at 1, 3, 7 days after 90 min of transient middle cerebral artery occlusion in young and aged brains. The number of NG2 positive cells increased in the ischemic penumbra at 3 and 7 days after reperfusion. At 7 day, the number of NG2 positive cells was significantly greater in the young than the aged brains, and the processes of NG2 positive cells enlarged and were more highly branched in the young than the aged brains. These results suggest that the young brain shows a higher potential of proliferation and process branching of OPCs than the aged brain.

Aging↗
PubMed2003

Electrocardiogram is very useful for predicting acute heart failure following myeloablative chemotherapy with hematopoietic stem cell transplantation rescue.

A prospective study was conducted in 71 evaluable patients who received myeloablative hematopoietic stem cell transplantation (HSCT) at our facility from 1995 to 2002, to find a sensitive marker for post-transplant heart failure, including echocardiographic systolic and diastolic markers and QTc interval. QTc was found to be an independent and significant risk factor for acute heart failure (AHF) on multivariate logistic regression analysis (OR 1.5, P=0.01, 95% confidence interval (CI) 1.1-2.0), while no significant differences between patients with AHF and those without AHF were found in age, sex, treatment history, type of conditioning regimen, and echocardiographic systolic and diastolic markers. On further analysis, post-transplant risk of AHF appeared to be increased as QTc was prolonged. The post-transplant risk of AHF in the group with longest QTc on multivariate logistic regression analysis was found to be 9.8 times that in the group with shortest QTc (P=0.04, 95% CI 1.0-100). These results suggest that echocardiographic markers are less valuable predictors of post-transplant AHF, but that prolongation of the QTc, an ECG marker, before HSCT is strongly associated with onset of AHF after HSCT.

Acute Disease↗
PubMed2003

A survey on awareness and utilization of new asthma management guidelines in Japan.

The present questionnaire survey, designed to interview Japanese internists and pediatricians who were specialists or nonspecialists in allergy or asthma, was conducted to determine the acceptance of "Asthma Prevention and Management Guidelines 1998" 1 year after release. The surveyor visited each physician and used the questionnaire form at the interview. Replies were obtained from a total of 5,963 physicians. The percentage of physicians who were aware of the guidelines was 96% among specialists and 68% among nonspecialists. Among the internists who were aware of the guidelines, the percentage of physicians giving a reply of "I refer to them often" or "I refer to them" in the actual diagnosis and management of asthma was 95% among specialists and 92% among nonspecialists. Therefore, reference was very high. Except for nonspecialists among pediatricians, not less than 60% of physicians expected that propagation of the present guidelines would allow a further decrease in asthma death and further improvement of patient's quality of life. The present survey revealed an increase in guideline awareness over the last several years, which was especially marked in nonspecialists. Furthermore, high reference and high expectancy also verified that physicians recognize the contents of the present guidelines as appropriate.

Asthma↗
PubMed2003

[Esophageal perforation after an anterior cervical fixation; report of a case].

We report 1 case of esophageal complications after anterior plate fixation of the cervical spine. A 62-year-old man underwent anterior cervical fusion in August 1996, and he did well after the operation. In January 1998, he was hospitalized for cardiac failure and was incubated twice for 10 days to cure. In March 1998, he suffered from dysphagia and continuous fever. Gastric fiberscopy showed the internal defect of esophagus and the plate to fix the cervical spine. He underwent immediate neck exploration via the cervical fusion incision, however he died of sepsis and respiratory failure. An esophageal perforation after an anterior cervical operation is an uncommon but well-recognized complication of the approach.

Cervical Vertebrae↗
PubMed2002

Platelet recovery after eradication of Helicobacter pylori in patients with idiopathic thrombocytopenic purpura.

The association between Helicobacter pylori ( H. pylori) infection and idiopathic thrombocytopenic purpura (ITP) has been reported by several groups. We investigated the prevalence of H. pylori infection and the effectiveness of its eradication in Japanese patients with ITP. H. pylori infection was found in 21 of 30 patients (70.0%) by (13)C urea breath test and presence of serum antibodies to H. pylori. H. pylori was eradicated in 18 of the 21 infected patients (85.7%) by administration of a proton pump inhibitor and two kinds of antibiotics. In only one patient was medication discontinued due to skin rash on the 4th day of treatment. Platelet recovery was obtained in ten patients (55.6%). In two patients with treatment failure, platelet recovery was obtained after successful re-eradication. In three patients without H. pylori infection, platelet counts did not significantly increase with the same treatment. On the other hand, eradication therapy did not affect platelet counts in patients with gastric ulcer. In conclusion, H. pylori eradication can be used for initial treatment with tolerable adverse effects in some ITP patients.

Adult↗
PubMed2002

Sulfation of bisphenol A abolished its estrogenicity based on proliferation and gene expression in human breast cancer MCF-7 cells.

Bisphenol A, an endocrine-disrupting chemical, is widely used in many consumer products. We previously showed the sulfoconjugation of bisphenol A catalyzed by a human thermostable phenol sulfotransferase, ST1A3. The estrogenic potency of bisphenol A sulfate was compared with that of bisphenol A by an E-screen assay using human breast cancer MCF-7 cells. An increase in the expression level of an estrogen-responsive pS2 gene was also examined using MCF-7 cells after exposure to bisphenol A and its sulfate for their estrogenicity. Bisphenol A sulfate did not exhibit estrogenic effects at 0.1 microM (E-screen assay) and 1 mM (pS2 gene expression) compared with bisphenol A, which exhibited the effects at 3 nM (E-screen assay) and 1 microM (pS2 gene expression), respectively. We have therefore evaluated major roles of cytosolic phenol sulfotransferase in the human liver. Bisphenol A sulfation in human liver cytosols was inhibited by more than 90% by p-nitrophenol and quercetin, a typical substrate and specific inhibitor of phenol sulfotransferase, respectively. These results indicated that the estrogenicity of bisphenol A was abolished through its sulfation catalyzed by a human hepatic thermostable phenol sulfotransferase.

Arylsulfotransferase↗
PubMed2002

Interaction between hydroxyapatite and proteins by liquid chromatography using simulated body fluids as eluents.

Hydroxyapatite (HAp) column chromatography for proteins using simulated body fluids (SBFs) as eluents was investigated in order to mimic the flow environment of human body fluid on the HAp surface in vivo. Acidic plasma proteins such as albumin, gamma-globulin, and fibrinogen having carboxyl groups with a negative charge were suggested to adsorb at positively charged sites (Ca sites) on the HAp surface. These acidic plasma proteins were not even eluted at higher inorganic ion molarities of human body fluid. Whereas basic proteins such as papin, cytochrome c, and lysozyme were easily eluted at lower inorganic ion molarities of human body fluid due to existing Na(+), Ca(2 +), Mg(2 +) and (CH(2)OH)(3)CNH(4)(+) ions in the eluents. The elution behavior of proteins using SBF in the presence or absence of glucose did not change. From these considerations, bone matrix proteins as acidic and neutral proteins would be considered an advantageous condition in order to adsorb on HAp in vivo.

Journal Article↗
PubMed2002

Effectiveness of washed platelet concentrate and red cell transfusions for a patient with anhaptoglobinemia with antihaptoglobin antibody.

A 71-year-old Japanese male with myelodysplastic syndrome progressing to overt leukaemia and hepatocellular carcinoma developed dyspnea and urticaria immediately after infusion of platelet concentrate (PC). He exhibited an identical reaction following blood transfusion. Serum haptoglobin was undetectable. The patient was determined to be homozygous for Hp(del) by polymerase chain reaction (PCR). Antibody to haptoglobin was detected by enzyme-linked immunosorbent assay (ELISA) and Western blot analysis. No antibodies against human leucocyte antigen (HLA) or platelet-specific antigens were detected. Washed PC and washed red blood cells were effective in preventing the transfusion-related anaphylactoid reactions.

Aged↗
PubMed2002

Localization of [14C]clarithromycin in rat gastric tissue when administered with lansoprazole and amoxicillin.

After oral and intravenous administration of [14C]clarithromycin to rats, c. 60-70% of the radioactivity in the gastric tissue was found to be distributed in the mucosal layer. Co-administration of lansoprazole and amoxicillin had no apparent effect on this distribution pattern of [14C]clarithromycin. The amount of unchanged [14C]clarithromycin in gastric contents increased with co-administration of lansoprazole and amoxicillin. Microautoradiograms of the gastric mucosa showed that [14C]clarithromycin was highly distributed in the mucous layer and in surface epithelial cells following oral administration. Homogeneous distribution of radioactivity was evident in the fundic gland. With iv administration, [14C]clarithromycin seemed to be secreted by both secreting cells in the gland base and surface epithelial cells.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2002

Clinical significance of serum E-cadherin levels in patients with haematological malignancies.

E-cadherin is a transmembrane glycoprotein that mediates Ca2+-dependent intracellular adhesion in normal epithelial cells. E-cadherin levels in serum are known to be significantly elevated in patients with epithelial carcinomas. However, the role of E-cadherin in haematopoietic cells is less clear. In this study, serum E-cadherin levels were therefore determined in patients with acute or chronic leukaemia, malignant lymphoma or myelodysplastic syndromes. Significant elevation of serum E-cadherin levels was detected in patients with haematological malignancies, and between types of acute leukaemias or subtypes of myelodysplastic syndromes, stages of malignant lymphoma, and phases of chronic leukaemia, respectively, compared with those in healthy adult volunteers. These findings suggest that E-cadherin might be expressed in malignant haematopoietic cells and might be useful as a diagnostic indicator in haematological malignancies.

Acute Disease↗
PubMed2002

E-cadherin expression in lymph nodes of three patients with non-Hodgkin's lymphoma.

The E-cadherins are a family of cell-cell adhesion molecules. These molecules exhibit Ca2+ dependent cell adhesion and are expressed on epithelial cells. E-cadherin levels in serum are known to be significantly elevated in patients with epithelial carcinomas. We determined serum E-cadherin levels in 30 patients with non-Hodgkin's lymphoma (NHL) using an enzyme immunoassay and then investigated whether E-cadherin is expressed on lymphoma cells in lymph nodes of three cases selected to analyze from 15 cases of serum E-cadherin levels over mean + 2SD with monoclonal antibody immunohistochemistry. Results indicated that E-cadherin antigen is expressed on the lymphoma cells in these three patients with NHL, and that soluble E-cadherin might be released into blood from lymphoma cells. Expression of E-cadherin may contribute to the morphological appearance of some malignant lymphoma, although no conclusion can be drawn based on such small number of patients analyzed.

Adolescent↗
PubMed2002

[Delayed hydrothorax induced by a pericutaneous central venous catheter; report of a case].

We report herein a case of 53-year-old woman who suffered a hydrothorax induced by a central venous catheter which had been placed to facilitate total parenteral nutrition. The central venous catheter was inserted into the superior vena cava through the right subclavian vein. Chest X-ray film after insertion revealed proper position of the tip. She suddenly developed dyspnea and tachycardia due to right-sided hydrothorax 21 days after the insertion of the catheter. Chest X-ray showed massive pleural effusion in the right thorax, and the catheter tip inadvertently turned upward. The continuous mechanical force of the catheter tip against the SVC wall was considered to be the cause of this life-threatening delayed hydrothorax.

Catheterization, Central Venous↗