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Biomedical subjects

S Oka

Publications and source records attributed to S Oka.

At least 163 records · Page 9Linked to original sources
PubMed1999

Characterization of fibroblast growth factor-6 expressed by Chinese hamster ovary cells as a glycosylated mitogen for human vascular endothelial cells.

The gene for fibroblast growth factor (FGF)-6/hst-2 was originally identified by its close homology with the FGF-4/hst-1 gene. Aside from its ability to transform cultured fibroblasts, the characteristics of FGF-6 protein have only been studied using a simple preparation from E. coli. In the present study, we expressed FGF-6 cDNA in CHO cells and characterized the resultant protein. We found that CHO cells secreted several forms of the FGF-6 polypeptide, and that there were multiple N-terminal modifications. The longest form (18-kDa) contained the sequence, SerProAlaGlyAlaArg, as its N-terminus, which was consistent with the signal peptide cleavage site predicted from its primary structure. The core polypeptide was primarily modified by heterogeneous N-glycans that were sialylated to a small degree; among them, biantennary structures were found to predominate. Moreover, possible O-glycosylation was also detected. N-glycosylated FGF-6 potently induced DNA synthesis and proliferation of human vascular endothelial cells, whereas in the absence of N-glycosylation, FGF-6 mitogenicity was substantially diminished. The results clearly indicate that FGF-6 expressed by mammalian cells is a glycosylated mitogen for vascular endothelial cells and further suggests that N-glycosylation plays a key role in determining the mitogenicity of FGF-6.

Animals↗
PubMed1999

Use of indirectly immobilized recombinant p17 antigen for detection of antibodies to HIV-1 by enzyme immunoassay.

Recombinant HIV-1 p17 antigen (rp17) and maltose binding protein-rp17 fusion protein (MBP-rp17) were immobilized in different ways: rp17 and MBP-rp17 were immobilized directly onto polystyrene beads by physical adsorption, and biotinyl-rp17, biotinyl-MBP-rp17, and 2,4-dinitrophenyl (DNP)-MBP-rp17 were immobilized indirectly onto polystyrene beads, which had been coated with streptavidin alone, with biotinyl-bovine serum albumin and streptavidin and with (anti-2,4-dinitrophenyl group) IgG. These immobilized antigens were tested by incubation with diluted serum from an HIV-1 seropositive subject in the absence and presence of serum from HIV-1 seronegative subjects and, after washing, with rp17 beta-D-galactosidase conjugate. Higher positive signals (fluorescence intensities for bound -beta-D-galactosidase activity) and less serum interference were obtained with indirectly immobilized antigens than with directly immobilized ones. Enzyme immunoassay using biotinyl-MBP-rp17 indirectly immobilized onto polystyrene beads, which had been coated sequentially with biotinyl-bovine serum albumin and streptavidin, was approximately 1,000-fold more sensitive than that using directly immobilized rp17 antigen and Western blotting for p17 band. This enzyme immunoassay indicated positivity in HIV-1 seroconversion serum panels as early as or even earlier than conventional methods and considerably earlier than Western blotting for HIV-1 p17 band. In addition, the sensitivity was further improved approximately 10-fold by incubation with shaking for immunoreactions and by increase of both the number of polystyrene beads and the volume of serum samples used per assay.

2,4-Dinitrophenol↗
PubMed1999

Less invasive surgery for early gastric cancer based on the low probability of lymph node metastasis.

BACKGROUND: Less invasive treatment is the current trend in many surgical fields. Most patients with early gastric cancer do not have lymph node metastasis. Thus extensive resection of the stomach and extended lymph node dissection do not appear to be necessary. METHODS: In a retrospective study, 890 consecutive patients with early gastric cancer who had undergone standard gastrectomy were assessed for depth of invasion, gross appearance, and maximum diameter of the tumor to examine the possibility of limiting the extent of lymph node dissection. A variety of limited gastrectomies have been developed and now include endoscopic mucosal resection, wedge resection, segmental gastrectomy, limited proximal gastrectomy, and distal hemigastrectomy. RESULTS: A retrospective study revealed that extensive lymph node dissection did not improve the survival of patients with early gastric cancer. Endoscopic mucosal resection was suitable for cancers of the depressed type of less than 1 cm in diameter and the elevated type of less than 2 cm in diameter. Wedge, segmental, or limited proximal gastrectomy was suitable for the elevated type of 2 to 3 cm in diameter. The elevated type of more than 3 cm in diameter and the depressed type of 1 to 3 cm in diameter sometimes involved metastasis to group 1 nodes. The depressed type of more than 3 cm in diameter sometimes involved metastasis to group 2 nodes. Thus such cases should be treated by gastrectomy with dissection of potentially metastatic lymph nodes. CONCLUSIONS: Limitation of the extent of gastrectomy and lymph node dissection may be possible, depending on the gross appearance and size of the tumor.

Adult↗
PubMed1999

[Concomitant mitral valvuloplasty and fenestrated total cavopulmonary connection: a case report].

A seven-year-old boy with tricuspid atresia successfully underwent a fenestrated total cavopulmonary connection and mitral valvuloplasty. Preoperative cardiac catheterization showed a mean pulmonary artery pressure of 16 mmHg. Pulmonary arteriography showed poor development of the branches (PA index: 180). Echocardiography revealed mild to moderate mitral valve incompetence due to prolapse of anterior leaflet. Mitral valve was exposed through the trans-septal approach. The excess chorda length was tucked into a longitudinal split in the top of the posterior papillary muscle. Then wedge resection of the redundant segment of the anterior leaflet and bilateral annuloplasty were performed. Finally, a total extracardiac cavopulmonary anastomosis with a 6 mm fenestration was completed. Postoperative clinical course was uneventful, and he is doing well with no recurrence of mitral incompetence 1 year after the operation.

Child↗
PubMed1999

[Midterm results of bilateral enlargement of the aortic valve ring for valve replacement].

From 1989, 4 patients underwent bilateral enlargement of the aortic valve ring for valve replacement. Age at the operation ranged from 2 to 8 (mean 6) years; body weight ranged from 14.9 to 25.4 (mean 19.0) kg. This procedure enabled us to implant a prosthesis 3 to 4 sizes larger (19 to 23 mm) than that measured with the native aortic annulus (13 to 17 mm). There was no late death and no cardiac event over a mean follow-up period of 6.2 years. Pressure gradient across the prosthesis measured by echocardiography was 40 mmHg in 1 patient who underwent aortic valve replacement with the use of 19 mm St. Jude Medical valve at 2 years of age. There was no significant pressure gradient in other 3 patients. All patients showed normal left ventricular function. We conclude that bilateral enlargement of the aortic valve ring for valve replacement has provided good midterm results with no mortality and no cardiac event.

Aortic Valve↗
PubMed1999

[A surgical case of right coronary artery-right atrial fistula complicated with postoperative myocardial infarction].

We report a 10-year-old girl with a right coronary artery-right atrial fistula and aneurysm formation. The proximal orifice was closed from the inside of the aneurysm, and the distal orifice through the right atrium under cardiopulmonary bypass. On the 9th postoperative day, myocardial infarction developed due to thrombosis in the fistula stump and the dilated coronary artery. Thrombosis may have been induced by postoperative dehydration and inadequate anticoagulant therapy. It is important to minimize a fistula stump and to strictly administer postoperative anticoagulant therapy.

Arterio-Arterial Fistula↗
PubMed1999

[Usefulness of galea suturing method for scalp closure].

A method for scalp closure to prevent alopecia along a suture line is described. Only the galea is sutured. By tacking a sufficient width of the galea on both sides with an absorbable suture material, the sutured wound forms a ridge. The outer layer is then closed with skin staples to keep the blood circulation undisturbed. This procedure contrasts with the traditional method in which the galea is sutured with the overlying subcutaneous tissue and consequently the hair follicles are strangled. By adopting the method of suturing the galea, development of alopecia along a suture line has been effectively prevented and scarring has become less conspicuous.

Alopecia↗
PubMed1999

[A case report of male alcoholics treated the left replacement prosthesis on account of the idiopathic avascular necrosis of the left femoral head].

Idiopathic necrosis of the femoral head is already described associated with alcoholism. However, it is unusual to meet alcoholic patient with idiopathic necrosis of the femoral head in psychiatric hospital. In this report, we describe about the psychiatric treatment of an alcoholic male patient who complicated idiopathic necrosis of the femoral head. He begun drinking a large amount of alcohol at the age of 20. After 32 years old, he repeated admission to psychiatric hospitals for the treatment against alcohol dependence. At the age of 35, he felt left hip pain. At 36 years old, the illness was diagnosed as idiopathic necrosis of the femoral head and osteotomy was performed. After the operation, he did not keep the direction to keep a rest and not to drink. At last, total replacement arthroplasty was undergone. All through the treatment, we supported the patient to participate in group therapy and Alcoholics Anonymous, and approached directively and supportively to gain an insight about problems of drinking. As a result, after the last operation he hoped psychiatric treatment of his own will and began to gain insight gradually about his own alcoholic problems. This case emphasizes the necessity of psychotherapeutic approach and treatment programs for alcohol dependence and its physical complications.

Adult↗
PubMed1999

[Prevention of MRSA spread in the neurological field: intranasal application of mupirocin calcium ointment].

From September 1997 to March 1998, forty patients with cerebral disorders were investigated. They were divided into two groups: one treated and the other untreated. Mupirocin calcium ointment (MCO) was applied three times a day for three days into the nasal cavities of the patients in the treated group. In order to check the growth of MRSA (methicillin-resistant Staphylococcus aureus), bacterial isolation culture from the nasal cavity was carried out on admission, one week after admission and one month after admission. MRSA was nor detected in isolation culture of any of the cases on admission. One week later MRSA was detected in isolation culture of one case of the 20 MCO treated patients and in three of the 20 untreated patients. There was no significant difference between treated and untreated groups. In isolation culture after one month, MRSA was recognized in four cases of 16 in the MCO treated group (three patients were discharged and one expired). On the other hand, it was recognized in eight cases of thirteen in the untreated group (seven cases were discharged). MRSA infection of the nasal cavity decreased significantly due to MCO treatment (p < 0.05). It is suggested that the nasal carriage of MRSA was prevented by intranasal application of MCO on admission.

Administration, Intranasal↗
PubMed1999

[Causes of death (1983-1997) in patients infected with human immunodeficiency virus by contaminated blood coagulation factor products: report of the clinical study group on prevention and treatments of HIV infection].

Our group conducted a national survey of patients who had died of acquired immunodeficiency syndrome (AIDS) after being infected with human immunodeficiency virus type 1 (HIV-1) by contaminated blood coagulation factor products. A total of 1446 hospitals, clinics, and other health-care institutions throughout Japan were enrolled in the study, which was supported by the Japanese government Ministry of Health and Welfare with a health sciences grant for research on HIV/AIDS. Of the 1434 registered patients who had been infected with HIV-1 by contaminated blood coagulation factor products, 493 (34%) had died as of Oct. 30, 1997. Most were hemophiliacs. The average CD4+ cell count was 25/microliter for the 398 who died of complications from AIDS, compared to an average of 158/microliter for those who died of other causes. Pneumocystis carinii pneumonia, cytomegalovirus infection, and atypical mycobacterial disease were the main causes of death in patients with AIDS. The annual death rate for AIDS patients in Japan dropped dramatically in 1997, 1 year later than a similar trend observed in the United States. The introduction and widespread adoption of new and effective drugs and treatment regimens for HIV-1 and opportunistic infections will be essential life-saving measures.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Purification and characterization of a glucuronyltransferase involved in the biosynthesis of the HNK-1 epitope on glycoproteins from rat brain.

The glucuronyltransferase involved in the biosynthesis of the HNK-1 epitope on glycoproteins was purified to an apparent homogeneity from the Nonidet P-40 extract of 2-week postnatal rat forebrain by sequential chromatographies on CM-Sepharose CL-6B, UDP-GlcA-Sepharose 4B, asialo-orosomucoid-Sepharose 4B, Matrex gel Blue A, Mono Q, HiTrap chelating, and HiTrap heparin columns. The purified enzyme migrated as a 45-kDa protein upon SDS-polyacrylamide gel electrophoresis under reducing conditions, but eluted as a 90-kDa protein upon Superose gel filtration in the presence of Nonidet P-40, suggesting that the enzyme forms homodimers under non-denatured conditions. The enzyme transferred glucuronic acid to various glycoprotein acceptors bearing terminal N-acetyllactosamine structure such as asialo-orosomucoid, asialo-fetuin, and asialo-neural cell adhesion molecule, whereas little activity was detected to paragloboside, a precursor glycolipid of the HNK-1 epitope on glycolipids. These results suggested that the enzyme is specifically associated with the biosynthesis of the HNK-1 epitope on glycoproteins. Sphingomyelin was specifically required for expression of the enzyme activity. Stearoyl-sphingomyelin (18:0) was the most effective, followed by palmitoyl-sphingomyelin (16:0) and lignoceroyl-sphingomyelin (24:0). Interestingly, activity was demonstrated only for sphingomyelin with a saturated fatty acid, i.e. not for that with an unsaturated fatty acid, regardless of the length of the acyl group.

Animals↗