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Biomedical subjects

M Osawa

Publications and source records attributed to M Osawa.

At least 127 records · Page 7Linked to original sources
PubMed1998

Polymorphism of the apolipoprotein E and angiotensin I converting enzyme genes in Japanese patients with myocardial infarction.

OBJECTIVE: To investigate the genetic contribution for myocardial infarction. METHODS: We investigated common polymorphisms of apolipoprotein E gene and angiotensin converting enzyme (ACE) gene in Japanese population. Subjects were 422 healthy people and 254 patients with myocardial infarction. We evaluated the 287 base pair (bp) insertion (I)/deletion (D) polymorphism in intron 16 of the ACE gene and a polymorphism in the apolipoprotein E gene by using the polymerase chain reaction. RESULTS: The ACE genotype prevalences for II, ID, and DD were 36.2, 46.1, and 17.7%, respectively, among the myocardial infarction patients. The prevalence of the D allele of the ACE gene among the myocardial infarction patients (0.593) exceeded that among the healthy controls (0.407). The prevalences of the epsilon 2, epsilon 3, and epsilon 4 alleles of the apolipoprotein E genotype among healthy controls were 0.024, 0.882, and 0.094, and those among survivors of myocardial infarction were 0.024, 0.834, and 0.142, respectively. Myocardial infarction patients had an excessive prevalence of the apolipoprotein E epsilon 4 allele (P < 0.05). Multiple regression analysis demonstrated that the independent risk factors for developing myocardial infarction were age, DD genotype of ACE gene, and apolipoprotein E epsilon 4 allele. Stenotic coronary vessels in myocardial infarction patients did not differ significantly among the patients with various ACE and apolipoprotein E genotypes in the present study. CONCLUSIONS: Among the Japanese, apolipoprotein E epsilon 4 carriers and subjects with ACE DD genotype are at an increased risk of myocardial infarction.

Aged↗
PubMed1998

Startle epilepsy with infantile hemiplegia: report of two cases improved by surgery.

PURPOSE: To study the effectiveness of surgical therapy on 2 patients with startle epilepsy with infantile brain damage (SEIBD), a rare but distinctive epileptic syndrome characterized by motor seizures resistant to antiepileptic drugs (AEDs). METHODS: The patients with SEIBD both had hemiplegia, due to gross contralateral hemispheric lesions, and suffered from tonic postural seizures, frequently provoked by sudden unexpected somatosensory stimuli on the paretic side of the body. These attacks occasionally caused the patients to drop to the floor, and mild-to-moderate injuries had been sustained; they were resistant to all currently available AEDs. Consequently, these daily drop attacks severely restricted the patients' social lives and school participation. Both patients underwent corpus callosotomy and resection of epileptogenic premotor and supplementary motor lesions. One patient also underwent additional multiple subpial transections of the primary sensorimotor area. RESULTS: Seizures, as well as quality of life, improved dramatically in both patients after surgery. CONCLUSIONS: Startle epilepsy with infantile hemiplegia is a distinct epileptic syndrome characterized by structural brain damage restricted primarily to one hemisphere, large ipsilateral epileptogenic lesions involving the perisensorimotor area, refractory startle-provoked drop attacks, and a good response to epilepsy surgery.

Adolescent↗
PubMed1998

Etiology of community-acquired pneumonia in hospitalized patients: a 3-year prospective study in Japan.

STUDY OBJECTIVE: To compare the etiology of community-acquired pneumonia in Japan and Western countries, the causative pathogens were prospectively investigated in patients requiring hospitalization. DESIGN: Prospective study over a 3-year period. SETTING: A community general hospital in Japan. PATIENTS: Three hundred twenty-six episodes of community-acquired pneumonia in 318 patients admitted to the hospital between July 1994 and June 1997. METHODS: The microbiological diagnosis was based on the results of quantitative sputum culture, blood culture, and other invasive procedures, including transthoracic needle aspiration or bronchoscopic examination. Serologic tests for Mycoplasma pneumoniae, Chlamydia spp, Legionella spp, and viruses were also routinely performed. RESULTS: Causative pathogens were identified in 199 episodes (61%). Streptococcus pneumoniae was the most common pathogen (23%), followed by Haemophilus influenzae (7.4%), M pneumoniae (4.9%), and Klebsiella pneumoniae (4.3%). The Streptococcus milleri group and Chlamydia pneumoniae were detected in 3.7 and 3.4% of the episodes, respectively. Pneumonia due to Legionella spp was recognized in only two patients. CONCLUSIONS: The etiology of community-acquired pneumonia in Japan did not differ markedly when compared with that of Western countries except for the low incidence of Legionella pneumonia. C pneumoniae and the S milleri group, which are emerging or newly recognized pathogens, were also significant causative microorganisms.

Adolescent↗
PubMed1998

Pulmonary Mycobacterium avium disease in a young patient with idiopathic CD4+ T lymphocytopenia.

A case of pulmonary Mycobacterium avium (M. avium) disease associated with idiopathic CD4+ T lymphocytopenia is reported. A rapidly growing pulmonary nodule was detected on a chest roentgenogram in a young man. Bronchoscopic examination revealed M. avium infection. Hematological studies showed a low CD4+ cell count in the absence of any identifiable immunodeficiency, including human immunodeficiency virus (HIV) infection. With the combination of chemotherapy and surgery, he had a good clinical outcome. Idiopathic CD4+ T lymphocytopenia should be considered in patients with unexplained opportunistic infection.

Adult↗
PubMed1998

Aneurysm surgery in Asia--Japanese situation.

This report is based on the results of the questionnaires conducted for the Japan Stroke Surgery Meeting 1996 (President: S. Kobayashi). The questionnaires were sent to all neurosurgical training institutions approved by The Japan Neurosurgical Society, numbering 959. The response rate was 54.2% (520 institutions). All statistics dealt with cases from January 1995 to December 1995. The total number of aneurysm surgery performed was 13,166. The average operative case number per institution during the year was 25. About 20% of the institutions exceeded 35 cases. Of all operative cases, 76.3% were ruptured aneurysms and 23.7% were nonruptured. Giant aneurysms were 2.9%; dissecting aneurysms 2.4%. Surgical procedures performed were clipping in 90.3%, wrapping in 5.2%, proximal ligation 1.6%, and bypass in 0.7%. Intravascular surgery was performed for 2.3% of the cases. Sugita clips were mainly used in 80.5% of the institutions, Yasargil clips in 6.6%, and both in 12.9%. For anterior communicating artery aneurysms pterional approach was mainly used in 81.0% of the institutions, interhemispheric in 7.2%, and both in 11.7%. For basilar terminal aneurysms, pterional approach was mainly used in 88.3% of the institutions, subtemporal approach in 6.6%, and both in 5.1%. The nonoperative cases included 24.9% of the ruptured aneurysms, 31.7% of the unruptured aneurysms, 38.4% of the giant aneurysms, and 52.1% of the dissecting aneurysms. The above statistics suggest that aneurysms are treated in Japan in most training institutions and that open surgical treatment is still the main procedure of choice.

Humans↗
PubMed1998

Sudden natural death in driving: case studies in the western area of Kanagawa.

To assess their incidence and implications, we made a retrospective study of sudden unexpected natural deaths during driving that occurred in the five year-period between 1992 and 1997. During that period, 188 postmortem examinations were performed on driver victims of traffic accidents. Of these, 15 (8%) were found to have died of natural causes such as heart disease or cerebral hemorrhage. Marked findings in this study were that no persons over 70 years of age and more occupational drivers suffered natural death. Although no passengers or pedestrians were injured, as many as eight vehicles collided with another object or vehicle. Sudden natural death, particularly from cerebral hemorrhage, of drivers might be hazardous to other road users.

Accidents, Traffic↗
PubMed1998

A case of acquired zinc deficiency in a mature breast-fed infant.

We describe a 5-month-old Japanese infant with zinc deficiency, who was exclusively breast-fed and showed improvement after zinc supplement was administered. His serum zinc level and the zinc content of breast milk from his mother were extremely low, although the mother's serum zinc level was within normal limits. Zinc deficiency would not be latently uncommon in a mature breast-fed infant.

Alopecia↗
PubMed1998

Changes in brain barbiturate concentration in brain-dead rabbits.

Pentobarbital concentration was evaluated in the brain tissues of brain-dead rabbits. Pentobarbital was infused into the vein of Japanese white male rabbits at 60 mg/kg/h until an isoelectric EEG of the cortex was reached. Brain death was induced by inflation of a balloon catheter placed in the subdural space. The diagnosis of brain death was confirmed by a flat line ABR wave. A significant increase in heart rate, intracranial pressure, and mean arterial pressure, was observed following brain death induction. These parameters returned to below basal values within 60 mm. Immediately after, and at 6 h and 24 h after brain death, each group of rabbits was sacrificed by phenobarbital overdose, and brains were then removed for determination of pentobarbital concentration in the brain tissue. Blood pentobarbital disappeared about 18 h after brain death was induced. Although the brain pentobarbital concentration slightly decreased over time, a high concentration of pentobarbital remained in the brain 24 h after brain death was induced.

Animals↗
PubMed1998

[Mediastinal germ-cell tumor associated with AML (M7)--the syndrome of mediastinal germ-cell tumors associated with hematologic neoplasia?].

In October 1992, a 36-year-old man was diagnosed as having mediastinum mixed germ cell tumor (stage II), and was treated with surgical operation and combination chemotherapy including VP16 (total VP16 dose; 1,500 mg/m2). After that, remission had been sustained, but leukocytosis (15,700/microliter) with 37% of peroxidase-negative blasts and thrombocytopenia developed in September, 1995. Bone marrow showed remarkable reticulin fibrosis and increase of atypical immature cells that were immunophenotypically factor VIII+/CD42+/CD61+. Thus, we diagnosed acute megakaryoblastic leukemia (M7). Based on no abnormality of chromosome 11q23 and no rearrangements of MLL gene, we diagnosed the syndrome of mediastinal germ-cell tumors associated with hematologic neoplasia. Furthermore, the neuron-specific enolase level was elevated (95.9 ng/ml). Soon after complete remission was reached by combination chemotherapy, the leukemia was relapsed, and the he died 3 months after the onset of leukemia. To our knowledge, this is the third case report of this syndrome in Japan and the first one of leukemia with high level of serum neuron-specific enolase.

Adult↗
PubMed1998

Impaired erythropoiesis in transgenic mice overexpressing a truncated erythropoietin receptor.

Erythropoietin (EPO), one of the pivotal regulators of erythrocyte production, transmits signals through the EPO receptor (EPOR). We have previously reported that human bone marrow (BM) cells express two dominant forms of the EPOR, one full-length and one truncated (EPOR-F and EPOR-T). Experiments with a cell line have shown that the EPOR-T acts as a dominant-negative regulator of EPOR-F-mediated signals. Its role in erythropoiesis in vivo, however, has yet to be clarified. Here we show the presence in mouse BM of a truncated form of the EPOR that is essentially the same as EPOR-T in humans. To investigate its role in vivo, we generated transgenic mice overexpressing mouse EPOR-T (EPOR-T-Tg mice). As a result, two independent EPOR-T-Tg lines were established. One line revealed mild anemia, but another line did not. When anemia was induced experimentally in these mice, however, both lines showed apparently poor recovery resulting in higher mortality than wild-type control mice. The impaired erythropoiesis found in these mice thus strongly suggests the EPOR-T's role as a negative regulator of erythropoiesis in vivo.

Anemia, Hemolytic↗
PubMed1997

Use of EBV-based Vector/HVJ-liposome complex vector for targeted gene therapy of EBV-associated neoplasms.

Targeted suicide gene therapy for Epstein-Barr virus (EBV)-associated neoplasms was attempted by using EBV-based plasmid vectors coupled with hemagglutinating virus of Japan (HVJ)-liposome in vitro. Expression of EBV nuclear antigen (EBNA)1 is a common feature of the neoplasms associated with EBV. When various leukemic cell lines were transduced with a vector carrying a marker gene and EBV replication origin of plasmid (oriP), the marker gene product was exclusively detected in cells expressing EBNA1. Transduction of herpes simplex virus (HSV)-1 thymidine kinase (Tk) gene resulted in a marked reduction in viable cell number by ganciclovir (GCV) specifically in EBNA1 positive cells. The results demonstrate that this virus-free system may be applicable to gene therapy of EBV-associated neoplasms.

Antiviral Agents↗
PubMed1997

Efficient gene transduction by Epstein-Barr-virus-based vectors coupled with cationic liposome and HVJ-liposome.

We show here a novel non-viral strategy to transduce human cells by using an EBV-based vector system. The EBV-based vectors, the plasmid vectors carrying EBV oriP (origin for plasmid replication) and EBNA (EBV nuclear antigen) 1 gene from EBV genome, were combined with 2 gene delivery systems, i.e., cationic liposome and HVJ-liposome. By both methods, EBV-based vectors could be more efficiently transfected into HeLa cells than non-EBV, conventional plasmid vectors. When human primary fibroblasts were transfected, EBV-based vectors coupled with cationic liposome but HVJ-liposome resulted in successful gene transduction, while human bone marrow cells were transduced with both HVJ-liposome- and cationic liposome-EBV vectors. These results suggest the potential applications of the EBV-based vector system for gene therapy.

Bone Marrow Cells↗
PubMed1997

Structure of the gene encoding human alpha 2-HS glycoprotein (AHSG).

Alpha 2-HS glycoprotein (AHSG) is a human plasma glycoprotein and fetuin is the homologue in the calf. In this report, we present the structure and organization of the AHSG gene. Introns and the 5' and 3'-flanking regions were obtained by polymerase chain reaction (PCR) and the inverted PCR, respectively, from genomic DNA using AHSG cDNA-specific oligonucleotide primers. The sequence of the PCR products shows that the coding region spans approximately 8.2 kb and is composed of seven exons interrupted by six introns. The exon-intron splice junctions agree with the consensus sequence, and the positions interrupted by introns are precisely identical to those of the rat insulin receptor tyrosine kinase inhibitor (fetuin) gene. The 5'-promoter region contains several characteristic sequences such as an A + T-rich sequence of TAAATAA, C/EBP-binding site, and hepatocyte nuclear factor-5 (HNF-5) and serum response factor (SRF) sites.

Animals↗
PubMed1997

Molecular cloning of a novel receptor-type protein tyrosine phosphatase from murine fetal liver.

A cDNA fragment encoding a novel tyrosine phosphatase (PTPase), termed ptpf, was isolated from day 11.5 mouse fetal liver using reverse transcription-polymerase chain reaction (RT-PCR) with degenerate primers. The 5.5-kb cDNA encoding the complete coding region was isolated from an adult mouse kidney cDNA library. This cDNA contained a single open reading frame (ORF) encoding a predicted 1436-amino-acid protein with a molecular mass of 161,150 Da. Sequence analysis revealed that PTPf was homologous to PTPmu and PTPkappa, and a putative receptor-type PTPase. Northern blotting analysis of adult mouse mRNA indicated the existence of four major ptpf transcripts of approximately 10, 6, 3 and 2.7 kb, and these transcripts were expressed in a tissue-specific manner. During embryogenesis, only the 6-kb transcript was detected.

Amino Acid Sequence↗