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Biomedical subjects

M Okano

Publications and source records attributed to M Okano.

At least 181 records · Page 10Linked to original sources
PubMed1992

Early activation of the proto-oncogene c-fgr during Epstein-Barr virus immortalization.

In an attempt to clarify the chronological relationships between Epstein-Barr virus (EBV) infection, B cell immortalization and c-fgr activation, we evaluated for the presence of EBV-determined nuclear antigen (EBNA), cellular DNA synthesis and expression of c-fgr-specific RNA following infection of human peripheral blood lymphocytes with B95-8 EBV. High expression of c-fgr was observed prior to EBNA detection and cellular DNA synthesis in EBV-infected cells. These results suggest that activation of c-fgr is an essential event during the early phase of EBV immortalization.

Antigens, Viral↗
PubMed1992

Protein deficiency impairs erythropoiesis in rats by reducing serum erythropoietin concentration and the population size of erythroid precursor cells.

Erythropoietin (EPO), a glycoprotein produced mainly by the kidney, is the major physiological regulator of erythropoiesis. We developed a sensitive and rapid ELISA for measurement of rat serum EPO with two monoclonal antibodies that recognize different epitopes. To understand the mechanism by which erythropoiesis is impaired in rats deficient in dietary protein, we investigated the levels of the immunoreactive EPO (iEPO) in serums and erythroid precursor cells in hemopoietic tissues during protein deprivation. The iEPO level of 32-d-old rats fed a protein-free diet was lowered to one-third that of rats fed 20% casein at 6 h after protein deprivation began. Protein deprivation decreased the number of EPO-responsive cells in spleen. These results indicate that the impairment of erythropoiesis during protein deficiency is caused by the decrease in serum EPO and the subsequent reduction of the population size of erythroid precursor cells in spleen.

Animals↗
PubMed1992

Analysis of antigenic determinants shared by two different allergens recognized by human T cells: house dust mite (Dermatophagoides pteronyssinus) and chironomid midge (Chironomus yoshimatsui).

To analyse the cross-reactivity of T-cell-mediated immunity between Dermatophagoides pteronyssinus (Dp) and Chironomus yoshimatsui (Cy), the most common allergens in Japan, we established antigen-specific human T-cell lines and clones. Some but not all of the Cy-induced T-cell lines showed a significant proliferative response not only to Cy, but also to Dp. No T-cell line responded to other unrelated antigens. When we stimulated the Dp-induced T-cell clones with Cy, 3 of the 40 clones (7.5%) showed a significant proliferation, and 2 of the 3 clones produced interleukin-4 and interferon-gamma, indicating their helper function. Cross-reactivity was diminished significantly after the absorption of Dp antigen in an anti-Cy affinity column. The cross-reactive epitopes were thought to be expressed on the Dp molecule of 45-53 kD. The presence of helper T cells reactive to both allergens suggests a possibility that this cross-reactivity might be involved in part in the high incidence of allergy to the 2 major allergens.

Allergens↗
PubMed1992

Primary immunodeficiency diseases and Epstein-Barr virus-induced lymphoproliferative disorders.

Increased incidence of malignant disorders is noted in patients with both primary and acquired immunodeficiency diseases. The pathogenetic mechanism(s) for these disorders remain unclear. Defective immunosurveillance of these patients, however, is mainly postulated to be responsible for the increased risk of these malignant disorders. Of the malignant disorders, Epstein-Barr virus (EBV)-induced lymphoproliferative disorders (LPD) have been increasingly reported, possibly due to improved therapeutic management techniques such as bone marrow transplantation, which results in prolonged survival periods for the primary immunodeficiency; the dramatic development of immunosuppressive treatments for transplant recipients; and the growing numbers of acquired immunodeficiency syndrome (AIDS) patients. This review focuses on the primary immunodeficiency diseases and EBV-induced LPD, and discusses pathogenetic mechanism(s) for the increased incidence of these malignant disorders.

Adolescent↗
PubMed1992

Endothelial cell morphometry of atherosclerotic lesions and flow profiles at aortic bifurcations in cholesterol fed rabbits.

Observations on shapes of endothelial cells both in sudanophilic and nonsudanophilic regions at bifurcations of the brachiocephalic (BC) and left subclavian (SA) arteries in hyperlipidemic rabbits were performed under a SEM. The stagnation point of flow and leading edges of flow dividers were nonsudanophilic and covered by round and long fusiform endothelial cells, respectively. The hips of flow dividers of both branchings, proven to be relatively low shear stress regions, by movement of microspheres in steady flow, were sudanophilic and covered by ellipsoidal cells. Similar studies were carried out in normolipidemic rabbits. It might be concluded that lipid deposition in hyperlipidemic rabbits occurs in relatively low shear stress regions, where endothelial cells are functionally activated, rather than in laminar high shear stress regions at the flow divider.

Animals↗
PubMed1992

[Comparison of polymerase chain reaction and IDEIA Chlamydia in detection of Chlamydia trachomatis from first-voided urine of male urethritis patients].

We have reported a method for detection of Chlamydia trachomatis by polymerase chain reaction (PCR) with two oligonucleotides based on sequences within the major outer membrane protein gene from C. trachomatis serovar L2. In the previous report, in addition to treatment of the mixture of first-voided urine (FVU) sediment and 1 ml of urine with proteinase K. DNA purification by phenol extraction was necessary for preparation of template DNA for PCR. In this study, FVU sediment was suspended in 1 ml of Chlamydiazyme dilution buffer and a part of the suspension was treated with proteinase K for DNA extraction. The DNA extraction solution could be used as template for PCR without purification of DNA by phenol extraction. One hundred FVU specimens obtained from male urethritis patients were examined with the two methods (PCR and IDEIA) for detection of C. trachomatis. In 33 of 100 specimens, the DNA fragments of C. trachomatis was amplified by the PCR and in 32 of 100, the chlamydial antigen was detected by IDEIA. The positive and negative coincidence rate of the PCR to IDEIA were 93.8% (30.32) and 95.6% (65/68) respectively, resulting in a high overall coincidence rate at 95%. Thus, the improved method with PCR using FVU as a specimen is proved to be a useful, non-invasive diagnostic tool for diagnosis of chlamydial urethritis.

Chlamydia trachomatis↗
PubMed1992

[Detection of Ureaplasma urealyticum by polymerase chain reaction].

A polymerase chain reaction (PCR) procedure for detection of Ureaplasma urealyticum was developed. A set of oligonucreotides based on sequences within the 16S ribosomal RNA gene from U. urealyticum were used as extension primers for the PCR. A DNA fragment of 397 bp was amplified by the PCR, when U. urealyticum DNA was template for the PCR. No amplified product was detected from other bacterial DNA including those of Mycoplasma genus. The amplified DNA fragment of 397 bp was detected on agarose gel electrophoresis, when DNA of > or = 10(2) cells of U. urealyticum per PCR was used as template for the PCR. Thus, the PCR procedure was shown to be a simple, rapid and specific method for detection of U. urealyticum and could be applied to detection of U. urealyticum from clinical specimens.

Base Sequence↗
PubMed1992

Synoptometer analysis of vertical shoot in Duane's retraction syndrome.

Vertical deviation of the affected eye caused by horizontal change of gaze was measured with a synoptometer in 5 cases of Duane's retraction syndrome type III. Step-by-step measurement clearly showed two types of incomitance patterns, i.e. upshoot and up- and downshoot in adduction. The former suggests a paradoxical synergistic innervation between the medial rectus and superior rectus muscles, and the latter suggests an abnormal vertical movement of the lateral rectus muscle over the globe on elevation or depression of the eye. Recession of the lateral rectus muscle, however, reduced the vertical deviation regardless of the incomitance pattern.

Adolescent↗
PubMed1992

Histochemical studies on the dependence of secretory function of the major vestibular gland (Bartholin's gland) on ovarian steroid hormones in the cat.

The dependency of the secretory function of the feline major vestibular gland (Bartholin's gland) on the ovarian steroid hormones was studied histochemically. After estrogen (estradiol-17 beta or diethylstilbestrol), progesterone or a combination of these was administered to cats which were previously ovariohysterectomized, the major vestibular glands were removed, embedded in paraffin, sectioned, and stained by alcian blue, periodic acid-Schiff or peroxidase-labeled lectin (peanut agglutinin and wheat germ agglutinin). The vividly positive reactions to the stainings applied were observed in the secretory epithelial cells of the major vestibular glands in the estrogen treated animals. The dependency of the secretory function of the major vestibular glands on the estrogen was demonstrated in this study.

Animals↗
PubMed1992

[Study on chemosensitivity test of urogenital tumors by ATP assay].

In order to improve the efficacy of chemotherapy against urogenital cancers, we developed a chemosensitivity test by measuring intracellular ATP in cancer cells. In the fundamental experiments using HeLa cells, a significant correlation was observed between intracellular ATP levels and numbers of viable cells. We employed 8 drugs, ADM, VCR, VLB, MTX, 5-FU, PEP, MMC, and CDDP for the assay Thirty-four renal tumors, 68 urothelial tumors and 19 testicular tumors were tested, and evaluable results were obtained in 25 specimens of renal tumors (76%) 55 specimens of urothelial tumors (80%) and 17 specimens of testicular tumors (98%). According to the ATP assay, renal tumors were sensitive to ADM and MMC, urothelial tumors to ADM, MMC and CDDP and testicular tumors to ADM and MMC. The ATP assay to determine the chemosensitivity to clinical specimens was sensitive and efficient. Thus the ATP assay could be applied for selection of anticancer drugs in the chemotherapy of urogenital cancers.

Adenosine Triphosphate↗
PubMed1992

Effect of short-term egg exclusion diet on infantile atopic dermatitis and its relation to egg allergy: a single-blind test.

A unique, single-blind, controlled trial of egg exclusion was performed in infants under 3 years of age, with atopic dermatitis, and/or their breast-feeding mothers. All subjects were put on an exclusion diet, but assessment of the effect of egg exclusion was made without knowing the results of allergy the tests. Results showed that there was a statistically significant correlation between the effect of egg exclusion and egg allergy, but only in infants 3-6 months old. Combination with other allergies did not seem to affect the results at this age. These findings indicate that egg exclusion is effective in ameliorating skin symptoms of atopic dermatitis only in early infancy and in the presence of egg allergy, irrespective of combination with other food allergies. This may be correlated to high RAST scores to egg at this age.

Child, Preschool↗
PubMed1992

Frequent association of Epstein-Barr virus in Japanese patients with Burkitt's lymphoma.

Seven Japanese patients with Burkitt's lymphoma (BL), residing in Hokkaido, were studied during the period, 1979-1991. Immunological analyses of their lymphoma cells showed all to express surface and/or cytoplasmic immunoglobulins. Chromosomal analysis was performed in five cases. Four of the five lymphomas had the chromosomal translocation, t(8;14), and one had t(2;8). Three patients had extremely high IgG antibody titers to Epstein-Barr virus (EBV) viral capsid antigen (VCA) and to EBV early antigens (EA). Two patients had positive antibodies to EA, and two others had normal antibody patterns comparable to those of EBV-seropositive age- and sex-matched healthy controls. Four of the seven lymphomas (57.1%) were positive for EBV-determined nuclear antigen (EBNA) by anticomplement immunofluorescence and/or EBV DNA using DNA-DNA reassociation kinetics, and/or Southern blot analysis. The frequency of EBV positivity in BL patients residing in Hokkaido was higher than that of cases previously reported in Japan. Three of the four EBV genome-positive BL patients responded well to chemotherapy, radiotherapy and/or surgical treatment, with no significant relapse being observed during the study period. In contrast, EBV genome-negative patients had poor prognoses despite having similar levels of clinical staging at the time of diagnosis.

Adolescent↗
PubMed1992

Epstein-Barr virus-associated lymphoproliferative disorders.

Herein we have provided a panorama of the clinical, histopathologic, and molecular biologic mechanisms of EBV-induced LPD particularly in immunosuppressed individuals. A listing of EBV-related diseases is shown in Table 4. We have stressed the frequent need to use multiple diagnostic methods for detecting EBV genome, particularly in immunodeficient patients who may fail to mount antibody responses to EBV. Given that we now recognize some of the immunocompromised patient populations at high risk for EBV-induced LPD, and have developed techniques for detecting EBV genome and early LPD, we may eventually prevent the occurrence of some of these life-threatening diseases. For example, we have learned to recognize and distinguish hepatic allograft rejection from EBV-induced LPD in hepatic biopsies (154). A periportal and sinusoidal infiltrate of small and large lymphoid cells, immunoblasts, and plasma cells, alert us to stain frozen liver sections for EBNA. Finding EBV guides the clinicians to reducing immunosuppression which then allows the restoration of immunosurveillance against the EBV-infected B cells. Whether an EBV vaccine can be successful in immunosuppressed individuals remains to be seen. As for other vaccines, many logistical problems prevail, such as the early occurrence of EBV infection during infancy in regions where BL is endemic. Surely, with the menacing threat that approximately 10% of patients with AIDS will develop NHL, new anti-viral therapy against EBV and the causative agent of AIDS and HIV, will be developed. The pathologist and virologist play essential roles in the recognition of EBV infection by performing clinical laboratory determinations. The characteristic histopathologic features of EBV-induced LPD are now recognized and when confirmed with molecular hybridization and immunofluorescent techniques will provide a solid diagnostic approach and, thus, a foundation for developing a sound therapeutic strategy.

Acquired Immunodeficiency Syndrome↗
PubMed1992

[Viral infection and its causative role for chronic fatigue syndrome].

Patients with chronic fatigue syndrome (CFS), of unknown etiology, have been increasingly reported. This syndrome is characterized by debilitating fatigue, lymphadenopathy, and fever. Herein, I focus on and review this syndrome from the view point of the causative role of viral infection. Since the symptoms of CFS are similar to those of chronic infectious mononucleosis (CIM) or chronic Epstein-Barr virus infection (CEBV), the role of EBV has been intensively studied. The etiological relationship between EBV and CFS, however, is questioned, like other lymphotropic viruses, including human retroviruses, adenoviruses and human herpesvirus 6. Additionally, severe chronic active EBV infection syndrome (SCAEBV) is also discussed in this review because symptoms of this disorder are similar to those of CFS but more severe in degree. Currently, the cause(s) and treatment of CFS are enigmatic and require further research and multidisciplinary study.

Adult↗
PubMed1992

[Measurement of serum PSA values by DELFIA PSA and its clinical significance on diagnosis and follow-up of prostate cancer patients].

Serum prostate specific antigen (PSA) values detected by DELFIA PSA were evaluated for usefulness in the diagnosis and follow-up of patients with prostate cancer. The system is time-resolved fluoroimmunoassay using europium as a tracer, which has a detectable range of 0.10-500 ng/ml with a small sample volume (25 microliters) and reliable quality control data. Furthermore, serum PSA values detected by the assay were equivocal to those detected by Tandem-R PSA. From the mean +3 S.D. of serum PSA values obtained on 227 normal males, 1.98 ng/ml was decided as an upper normal level. Serum PSA values in benign prostatic hyperplasia (BPH) (n = 69) and prostate cancer (n = 86) patients were statistically higher than those in normal males. However, when 1.98 ng/ml was used as a cut-off value, the false positive rate in BPH cases elevated up to 80%. Therefore, in the differential diagnosis of prostate cancer and BPH, we recommend 11.7 ng/ml (mean + S.D. in BPH cases) as a cut-off value, in which sensitivity is 72.1%, 88.4% are true negative in BPH, and efficacy is 79.4%. Serially determined serum PSA values in following up the patients with prostate cancer were confirmed to be highly effective for diagnosing recurrence and evaluating treatment responses. These findings suggest that DELFIA PSA is a useful tool for determination of serum PSA values.

Adult↗