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S Oka

Publications and source records attributed to S Oka.

At least 343 records · Page 19Linked to original sources
PubMed1991

Quantitative estimation of human immunodeficiency virus type-1 provirus in CD4+ T lymphocytes using the polymerase chain reaction.

The proviral burden of peripheral blood lymphocytes in 29 patients infected with human immunodeficiency virus type-1 (HIV-1) was estimated using a polymerase chain reaction method which we recently refined. The mean numbers of HIV-1 provirus in eight patients with AIDS and AIDS-related complex treated with zidovudine (AZT), in 10 asymptomatic patients treated with AZT, and in 11 asymptomatic untreated patients were 892, 436, and 406 copies in 1 x 10(5) CD4- T lymphocytes, respectively. These results demonstrate that patients may have more HIV-1 provirus copies in an advanced than early stage of disease, and that the fraction of the infected lymphocytes is much higher than previously thought, especially in asymptomatic patients. There was no difference in the viral burden in CD4+ T lymphocytes regardless of whether AZT had been administered or not. These findings validate the method used here to quantitate HIV-1 provirus DNA and confirm that AZT is not effective in reducing the amount of provirus DNA in lymphocytes.

AIDS-Related Complex↗
PubMed1991

Post-mortem diagnosis of human T lymphotrophic virus type-1 (HTLV-1) associated myelopathy by detection of HTLV-1 DNA in the spinal cord of a patient with post-transfusional myelopathy.

Human T lymphotrophic virus type-1(HTLV-1) is thought to be an etiological agent of HTLV-1 associated myelopathy (HAM). Therefore, a definitive diagnosis of HAM can not be made if information on the presence of antibody against HTLV-1 is not available, even though clinical and histopathological features strongly indicate the disease. In this study, HTLV-1 DNA was detected in the formalin-fixed, paraffin-embedded spinal cord of an autopsy case with post-transfusional myelopathy using the polymerase chain reaction (PCR). Ante-mortem HAM was not suspected of and the antibody has not been examined. Neuropathological examination of the sequential sections revealed a loss of axons and myelin sheaths in the white matter, resembling the histopathology of HAM. The post-mortem detection of HTLV-1 DNA by PCR may be useful for the confirmation of HAM in cases which were not provided with appropriate clinical data.

Autopsy↗
PubMed1991

Developmentally and spatially regulated expression of HNK-1 carbohydrate antigen on a novel phosphatidylinositol-anchored glycoprotein in rat brain.

HNK-1 carbohydrate antigen in an epitope expressed commonly in many cell surface adhesion and recognition molecules in the nervous system. We purified and characterized from rat brain a novel phosphatidylinositol (PI)-anchored 150-kD glycoprotein belonging to the HNK-1 family. The molecule (PI-GP150) was detected by combination of PI-specific phospholipase C treatment of brain membranes and Western blot analysis with mAb HNK-1. HNK-1-positive PI-GP150 was purified from the PI-PLC-released materials with three successive chromatographies (Sephacryl S-300, mAb HNK-1-Sepharose 4B, and Mono Q) and proven to be a novel molecule by immunoblot and structural analyses. Polyclonal antibody was raised against PI-GP150 and used to show that (a) PI-GP150 is expressed on the surface of neuronal cell bodies and their processes in culture, and (b) PI-GP150 appears during embryonic development and is present throughout all postnatal life in all brain regions. However, the expression of the HNK-1 epitope on PI-GP150 is regulated in both developmental stage-specific and region-specific manners. In newborn rats, the HNK-1 epitope is expressed on PI-GP150 throughout the brain. The level of HNK-1 epitope on PI-GP150 decreases after postnatal day 7 in hindbrain and becomes completely absent in adult myelencephalon and metencephalon. In contrast, HNK-1 epitope on PI-GP150 was constitutively expressed in telencephalon. Thus, while the HNK-1 carbohydrate epitope is strongly coupled to PI-GP150, its expression can be regulated independently of that of PI-GP150. The differential expression of the HNK-1 epitope at different rostro-caudal axial levels was observed also in other HNK-1 family molecules in brain membranes. These results suggest that the HNK-1 epitope plays an important role in adding region-specific and developmental stage-specific modifications on the function of the cell surface molecules.

Aging↗
PubMed1991

Thoracic myelopathy caused by ossification of the ligamentum flavum. Clinicopathologic study and surgical treatment.

The authors reviewed 14 patients with thoracic myelopathy caused by ossification of the ligamentum flavum (OLF). The predominant locality of symptomatic OLF was at the thoracolumbar junction, particularly at T10-11 followed by T11-12. At the level of the thickest OLF in each patient, there were three types of OLF from computed tomography and operative findings: a lateral type in 3 patients, diffuse in 8, and thickened nodular in 3. The diagnosis of OLF-related thoracic spinal canal stenosis was best made by enhanced computed tomography. Histologic study revealed that the developmental mode of OLF was mainly endochondral ossification. Numerous fibrocartilaginous cells were found in the increased and swollen collagen fibers forming the hypertrophic ligamentum flavum (HLF). Ossification extended along the superficial layer of HLF. The size or extension of OLF was relevant to the corresponding diathesis of spinalhyperostosis. Results of laminectomy for OLF were poor because of the high occurrence of complications early on or later deterioration. Therefore, laminoplasty is recommended as a successful procedure for OLF-related thoracic myelopathy, avoiding further local mechanical stress due to tensile force.

Female↗
PubMed1991

Os odontoideum with posterior atlantoaxial instability.

Nine patients who had os odontoideum with posterior atlantoaxial instability are reviewed. Three parameters were measured on the lateral radiographs: the distance from the os odontoideum to the spinous process of the axis in extension (Dext), the distance from the os odontoideum to the posterior arch of the atlas (Datl), and the degree of instability (Inst). Patients were classified into four groups: Group I, local symptoms (N = 3); Group II, transient myelopathy (N = 0); Group III, progressive myelopathy (N = 6); and Group IV, cerebral symptoms (N = 0). The development of cervical myelopathy was not related to degree of instability but to distance from the os to the spinous process of the axis (Dext). Dext was more than 16 mm in Group I and less than or equal to 16 mm in Group III. Five of six patients in Group III underwent myelography. Based on myelographic findings, Group III was further subdivided into two groups, Group IIIA (N = 2) and Group IIIB (N = 3), according to the following characteristics: In Group IIIA, the distance from the os to the posterior arch of the atlas was more than 13 mm, and the spinal cord was impinged between the os odontoideum and the lamina of the axis in extension and reduced in flexion. In Group IIIB, Datl was less than or equal to 13 mm, and the spinal cord was compressed at the level of the atlas during flexion and extension. Stenotic Datl of 13 mm or less specifically defined severe cervical myelopathy. Surgical treatment for cervical myelopathy in os odontoideum with posterior instability is suggested as follows: in the absence of canal stenosis of the atlas (Group IIIA), atlantoaxial fusion in a reduced position is indicated; when associated with canal stenosis of the atlas (Group IIIB), laminectomy of the atlas followed by occiput-to-C2 arthrodesis is indispensable.

Adolescent↗
PubMed1991

Rapid serodiagnosis of human mycobacteriosis by ELISA using cord factor (trehalose-6,6'-dimycolate) purified from Mycobacterium tuberculosis as antigen.

IgG antibodies against purified cord factor (trehalose-6,6'-dimycolate, TDM) in sera of 99 patients infected with mycobacteria (42 patients with tuberculosis excreting tubercle bacilli in the sputum, 11 patients with non-tuberculous mycobacteriosis excreting acid-fast bacilli in the sputum, and 46 patients without bacilli in the sputum but diagnosed as having pulmonary tuberculosis by chest X-ray films and physical examination), five patients with lung cancer, and 100 healthy controls which included subjects positive and negative for the tuberculin test were tested by the ELISA with TDM purified from Mycobacterium tuberculosis H37Rv as the antigen. Of the 99 cases of mycobacteriosis, 83 patients (83.8%) had positive results (48 samples from 53 patients, or 90.5%, with bacilli in the sputum, and 35 samples from 46 patients (76%) with tuberculosis diagnosed clinically). The sera of the five patients with lung cancer and the 100 controls all gave negative results. Thus, the sensitivity and specificity were 83.8% and 100%, respectively. ELISA with TDM as the antigen is simple, reproducible, and useful for the rapid serodiagnosis of general mycobacterial infections including tuberculosis, because it does not involve the cultivation of bacteria.

Adult↗
PubMed1991

[Bacterial meningitis in the elderly with neurosurgical procedures].

Bacterial meningitis is one of complications in the elderly with neurosurgical procedures. In an attempt to find the clinical features of this complication we analyzed 10 cases, which were found in 30 cases of the bacterial meningitis in Tokyo Metropolitan Geriatric Hospital from 1972 to 1989. The patients were 4 males and 6 females, 52-86 years old (the mean, 69). While 2 Enterococcus species were isolated after craniotomy, Staphylococci were common pathogens (4 S. aureus, 4 S. epidermidis and 1 P. aeruginosa) in patients with shunt infection. Most of these patients lacked typical manifestations of meningitis except the fever. Symptoms occurred long after surgery with little abnormality in the data of serum and cerebrospinal fluid. However, blood cultures were positive in 75% of the cases. Removal of the infected catheter was effective in the cases of shunt infection.

Aged↗
PubMed1991

[A case of human-immunodeficiency virus infection related Mycobacterium tuberculosis with atypical clinical features].

Increasing rates of human immunodeficiency virus (HIV) related tuberculosis have been noted and recently the clinical importance of the disease has been mentioned. The diagnosis of tuberculosis is more difficult in those patients with HIV seropositive than those with seronegative, because those with seropositive have atypical clinical features. A 29-year-old male, who was infected with HIV heterosexually in Central Africa in 1986, was admitted to our hospital with a history of general malaise and weight loss in April, 1989. Laboratory and physical examinations revealed anemia, thrombocytopenia, the elevation of LDH, and giant intraabdominal lymphadenopathies, suspecting malignant lymphoma. Mycobacterium was isolated from the sputa in April and was confirmed as M. tuberculosis using a DNA probe in May, 1989. Clinical symptoms including giant lymphadenopathies and laboratory abnormalities improved with antituberculosis therapy. Development of a rapid method for the diagnosis of tuberculosis was warranted in this case.

AIDS-Related Complex↗
PubMed1991

Evaluation of acridinium-ester-labeled DNA probes for identification of Mycobacterium tuberculosis and Mycobacterium avium-Mycobacterium intracellulare complex in culture.

The detectability of mycobacteria in culture by the use of nonisotopic, chemiluminescent DNA probes for Mycobacterium tuberculosis and the M. avium-M. intracellulare complex (MAC) was evaluated and compared with that by the use of 125I-labeled DNA probes for the same mycobacteria. In the assay, rRNA-directed DNA probes labeled with acridinium ester (AE-DNA probes) were used. Unhybridized probes were chemically degraded, and the esterified acridinium on the hybridized probes was hydrolyzed by the addition of alkaline hydrogen peroxide solution, resulting in the production of visible light which was measured with a luminometer. The detection limits of the AE-DNA probes were almost the same as those of the 125I-labeled DNA probes. A total of 107 clinical isolates of mycobacteria (47 isolates of M. tuberculosis, 36 MAC, and 24 atypical mycobacteria other than MAC) were tested. The sensitivity and specificity of the AE-DNA probes for M. tuberculosis were 100% both for the conventional method and with the 125I-labeled DNA probe. The sensitivity and specificity of the AE-DNA probes for MAC were 97.2 and 100%, respectively, for the conventional method and were both 100% with the 125I-labeled DNA probes. Because the procedure is simple, reliable, rapid (it can be completed within an hour), and safe (it does not use radioisotopes), it can easily be performed in any clinical laboratory.

Acridines↗
PubMed1991

Detection of Pneumocystis carinii sequences by polymerase chain reaction: animal models and clinical application to noninvasive specimens.

Pneumocystis carinii is a eukaryotic microbe which causes fatal pneumonia in patients with AIDS. Oligonucleotide primers were used to amplify the 5S rDNA sequence of P. carinii by the polymerase chain reaction (PCR) in various clinical and animal samples. Of 35 independent lung specimens tested, PCR detected the P. carinii sequence in all 23 cases which were known to be P. carinii infected, i.e., 15 from mice, 1 from rat, 3 from human autopsy, and 4 from biopsy of AIDS patients by needle aspiration. The results were consistent with clinical and microscopic diagnosis. The detection was highly sensitive and specific. Direct sequencing of these amplified DNAs revealed homogeneity of 5S rDNA sequences of independent isolates from mice, rats, and humans. Preliminary trials manifested efficacy of the PCR method to detect P. carinii sequences in induced sputum or blood from AIDS patients, the latter case suggesting that P. carinii might enter peripheral blood via phagocytosis or direct intrusion. Development of less-invasive or noninvasive PCR diagnostic techniques to detect P. carinii infection would greatly facilitate therapeutic and prophylactic management of P. carinii pneumonia.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Purification and characterization of a sea squirt beta-galactosidase.

A beta-galactosidase was extracted from the internal organs of a sea squirt, Styela plicata, and purified 959-fold, with an 18% yield, by successive gel chromatography, anion-exchange chromatography, chromatofocusing, and affinity chromatography on a Con A-Sepharose column. The purified enzyme was fairly homogeneous, as judged on disc PAGE, SDS-PAGE, and gel chromatography on a Sephadex G-200 column. The molecular weight of the enzyme was estimated to be 77,000 and 75,000 by gel chromatography and SDS-PAGE, respectively, and its isoelectric point was determined to be 4.9 by the isoelectric focusing method. The enzyme was substantially stable in the pH range of 3.5 to 7.5, the optimum pH being 4.0. The enzyme was significantly inhibited by 9 mM HgCl2 and 9 mM DFP, while the inhibition by 0.9% PCMB was only 60% at 0 degrees C for 30 min. The purified beta-galactosidase apparently liberated galactose from a sea squirt antigen (H-antigen), two allergenically active glycopeptides (Gp-1 and Gp-2) derived from another sea squirt antigen (Gi-rep), asialo-ovomucoid glycopeptide, asialo-fetuin glycopeptide, GA1, CDH, and an ABEE-derivative (Gal beta 1----3ThrNAc-ABEE) of Gal beta 1----3GalNAc-ol isolated from bovine submaxillary gland mucin.

Animals↗
PubMed1991

[Immunotherapy using high concentration purified antigen showed remarkable effect in all cases].

Hoya (sea-squirt) asthma is a typical type I occupational asthma. A total of 22 females with this disease whose age ranged from 22 to 69 years were treated for two years with high concentration purified sea-squirt antigen named Ei-M having a molecular weight of 22,800. One case who developed ordinary bronchial asthma abandoned the immunotherapy during the early stage of the therapy, but in the remaining 21 cases remarkable effects were rapidly observed from the early stage of treatment. These cases did not develop asthmatic attacks even through they engaged in oyster shucking work and no symptomatic therapy was indicated. Serum anti-Ei-M IgG antibody was significantly elevated after the therapy. None of the treated cases developed any side effects.

Adult↗
PubMed1991

Treatment of cervical spondylotic myelopathy by enlargement of the spinal canal anteriorly, followed by arthrodesis.

Thirty-seven patients who had enlargement of the spinal canal anteriorly and stabilization of the spine for cervical spondylotic myelopathy were followed for an average of forty-nine months (range, twenty-eight to seventy months). Myelography and computed tomographic myelography were performed preoperatively on all patients to determine the location and features of the areas of decompression. The canal was enlarged by discectomy; by subtotal corpectomy and removal of the anteromedial parts of the pedicles; or by removal of osteophytes or of the posterior longitudinal ligament, or both. Partial corpectomy and interbody arthrodesis was performed in nine patients; subtotal corpectomy, including removal of the posterior parts of the vertebral bodies and of the posterior longitudinal ligament, and strut bone-grafting, in fifteen patients; and subtotal corpectomy, with detachment of the remaining thin posterior parts of the vertebral bodies and of the posterior longitudinal ligament, and strut bone-grafting, in thirteen patients. Postoperatively, radiographic examinations, including myelography and computed tomographic myelography, were performed for thirty-six patients and magnetic resonance imaging, for twenty-eight. A satisfactory neurological result was obtained in twenty-nine patients. Atrophy of the spinal cord, as seen on preoperative computed-tomographic myelograms, was predictive of an unsatisfactory result of the decompression, as was weakness of the peroneal muscles. All but one of the thirty-seven patients had improved walking ability at the most recent follow-up examination: seventeen patients improved by 1 point; fourteen, by 2 points; four, by 3 points; and one, by 4 points. The remaining patient reverted to the preoperative status after an initial improvement. The ability to walk at the interim examinations was compared with that at the most recent examination; three patients had continuing improvement, while three others had deterioration. The main cause of deterioration was new spondylotic changes associated with stenosis of the spinal canal, occurring at the level of the disc just cephalad to the fused levels. We concluded that anterior decompression followed by a secure arthrodesis should be an extensive procedure for patients who have cervical spondylotic myelopathy, as determined preoperatively from a myelogram or computed tomographic myelogram. Excision of the vertebral bodies should also be wide and should include the anteromedial parts of the pedicles. The third or fourth cervical vertebra should be included in the arthrodesis prophylactically in patients who have stenosis of the spinal canal when either of these vertebrae is adjacent to the level of fusion.

Adult↗
PubMed1990

Variations by layers and developmental changes in expression of telencephalin in the visual cortex of cat.

The expression of telencephalin in visual cortex of cat and monkey was studied immunohistochemically. In adult cats and monkeys, immunoreactivity to a polyclonal antibody raised against telencephalin was especially low in layer IV, which receives massive afferent input from the thalamus. In kitten visual cortex, the antibody bound both layer IV and other cortical layers during the most sensitive period for ocular dominance plasticity. Outside the sensitive period, the staining of layer IV was selectively reduced. These findings suggest that the expression of telencephalin is developmentally regulated during the early period and may play a role in regulating plasticity during the sensitive period.

Aging↗
PubMed1990

Side-to-side choledochoduodenostomy: a reappraisal based on a study of 70 patients.

We experienced a total of 70 side-to-side choledochoduodenostomy cases and 80% of them were indicated for gallstone disease patients. There were no early postoperative complications, but intrahepatic gallstones developed in 2 cases. The size of the stoma and the width of the common duct were reduced about 30% within 3 postoperative months. Although clinical cholangitis did not occur in the presence of an adequate stoma, histological cholangitis was constantly seen throughout 10-year-follow-up period. Strictness of operative indications, and periodical and long term follow-up study of postoperative patients are mandatory to obtain better clinical results.

Bile Ducts, Intrahepatic↗
PubMed1990

Role of active oxygen species in diethyldithiocarbamate-induced gastric ulcer in the rat.

Diethyldithiocarbamate, an inhibitor of Cu,Zn-superoxide dismutase, was recently found to be ulcerogenic in the rat stomach, and active oxygen species were found to be responsible for its ulcerogenicity. To clarify which active oxygen species play a role in ulcerogenesis, the effects of various scavengers and iron-chelators were studied. As superoxide dismutase and catalase reduced the ulcerogenesis induced by diethyldithiocarbamate, the superoxide radical and hydrogen peroxide were considered to play a pathogenic role in this ulcer model.

Animals↗