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Biomedical subjects

H Oka

Publications and source records attributed to H Oka.

At least 73 records · Page 4Linked to original sources
PubMed2000

Serum immunosuppressive acidic protein and natural killer cell activity in patients with metastatic renal cell carcinoma before and after nephrectomy.

PURPOSE: To our knowledge the impact of nephrectomy on stage M1 renal cell carcinoma remains to be determined. We previously reported that nephrectomy is beneficial in patients with elevated serum C-reactive protein before treatment, and those in whom nadir C-reactive protein decreases postoperatively to within the normal range may expect longer survival when surgery is combined with postoperative immunotherapy. In this study we determine the effect of nephrectomy on the immune response in patients with metastatic renal cell carcinoma. MATERIALS AND METHODS: We retrospectively reviewed the records of 40 patients with metastatic renal cell carcinoma diagnosed at our institution between 1986 and 1999. These patients underwent nephrectomy before cytokine therapy with interferon. Before and after nephrectomy we measured serum C-reactive protein, serum immunosuppressive acidic protein and peripheral blood natural killer cell activity. RESULTS: In 15 patients with pretreatment serum C-reactive protein within the normal range (less than 1 ng./ml.) there was no significant difference before and after nephrectomy in the serum immunosuppressive acidic protein level or natural killer cell activity (p = 0.4587 and 0.3892, respectively). On the other hand, in 25 patients with serum C-reactive protein elevated before treatment to 1 ng./ml. or greater serum immunosuppressive acidic protein decreased significantly and natural killer cell activity increased significantly after cytoreductive surgery (p = 0.0002 and 0.0286, respectively). CONCLUSIONS: Our study implies that nephrectomy may be beneficial in patients with elevated serum C-reactive protein before treatment. Further evaluation by a prospective study is needed to make a definitive conclusion.

Adult↗
PubMed2000

Lysophosphatidylcholine induces urokinase-type plasminogen activator and its receptor in human macrophages partly through redox-sensitive pathway.

Urokinase-type plasminogen activator (uPA) and its cell surface receptor (uPAR) have been shown to be expressed in macrophages in atherosclerotic arterial walls, but the regulatory mechanisms of their expression remain unclear. The present study was performed to examine the effects of lysophosphatidylcholine (lysoPC), an important atherogenic lipid, on the expression of uPA and uPAR in human monocyte-derived macrophages. LysoPC upregulated the mRNA expression of uPA and uPAR, and it increased the protein expression of uPA in the culture medium and bound to the cell surface and of uPAR in the particulate fraction of the cells. LysoPC significantly increased the binding of the amino-terminal fragment of uPA to the treated cells and the cell-associated plasminogen activator activity. LysoPC stimulated superoxide anion production and increased intracellular oxidant levels in the cells. The combined incubation with reduced glutathione diethyl ester or N-acetylcysteine, antioxidants, suppressed the upregulation of uPA and uPAR mRNA and the increase in plasminogen activator activity by lysoPC. uPA and uPAR mRNA expression was also induced by the incubation with xanthine and xanthine oxidase, a superoxide anion-generating system. The results suggest that lysoPC increased the expression of uPA and uPAR and their functional activities in human monocyte-derived macrophages, at least in part through a redox-sensitive mechanism. This coordinate increase in the expression of uPA and uPAR in human macrophages by lysoPC could play an important role in plaque formation and disruption, arterial remodeling, and angiogenesis in atherosclerotic arterial walls.

Acetylcysteine↗
PubMed2000

Clinical cure of glioblastoma--two case reports.

We report two cases of "decade survivor" of glioblastoma. Case 1 is a 34-year-old female who developed a tumor in the left frontal pole, and Case 2 is a 46-year-old male with a left frontal tumor. Both tumors were surgically excised and the patients received postoperative chemo-radiotherapy. Histological re-evaluation of the resected tumor tissue confirmed the most malignant type of glioma-glioblastoma. We speculate that the entire extent of tumors had been extirpated by surgery in both cases.

Adult↗
PubMed2000

Solitary fibrous tumor arising from the falx cerebri--case report.

A 50-year-old female was admitted with headache and visual disturbance. Neuroimaging demonstrated a well-demarcated large tumor attached to the falx cerebri. The tumor was totally removed by surgery. Histological examination showed that the tumor consisted of spindle cells with no pattern in the collagenous background. Staghorn-like blood vessels were common. Immunohistochemical study showed the tumor cells were strongly positive for CD34 and vimentin, but negative for epithelial membrane antigen. The diagnosis was solitary fibrous tumor arising from the falx cerebri. Solitary fibrous tumor is rare within the cranial cavity, and can be distinguished from meningioma and hemangiopericytoma by the histological, ultrastructural, and immunohistochemical findings.

Brain Neoplasms↗
PubMed2000

Effects of scopolamine on working memory in rats in a delayed matching-to-position task, employing a subject-centered procedure.

The effect of scopolamine hydrobromide on a delayed matching-to-position task was examined while controlling for two confounding factors, i.e., mediating behavior and slow performance on a task. The task was given on the basis of a subject-centered method in which delay intervals are dependent on subjects' performance. The performance of individual subjects, rather than averaged group performance, was taken as the focus of the analysis. The results indicated that scopolamine had an effect not only on speed of performing the task but also on the length of the retention interval. The effects differed considerably among individuals: the effects on both the length of the retention interval and the speed of performance were found for two of the five subjects. An effect on speed of performance alone was found for one subject. No effects on either measure were found in a further two subjects.

Animals↗
PubMed2000

The role of volume weighted mean nuclear volume in predicting the prognosis of patients with primary transitional cell carcinoma of the upper urinary tract: a report of 102 new cases.

PURPOSE: We compare estimates of volume weighted mean nuclear volume (MNV) with histological grading to determine the prognosis of primary transitional cell carcinoma of the upper urinary tract using a Cox proportional hazards model. MATERIALS AND METHODS: We retrospectively reviewed 102 patients who underwent nephroureterectomy for primary transitional cell carcinoma of the upper urinary tract at our hospital between April 1981 and March 1997. Traditional prognostic factors, such as patient age, sex, stage and grade, multiplicity and unbiased estimates of MNV were analyzed with respect to disease recurrence and survival. RESULTS: Estimates of mean nuclear volume were significantly larger for patients with than without lymph node metastasis (p = 0.0031). No prognostic factor significantly correlated with recurrence of transitional cell carcinoma of the bladder. For pTxN0M0 cases univariate analysis revealed that histological grade (p = 0.0018), pathological T stage (p = 0.0030) and estimates of MNV (p = 0.0001) correlated significantly with disease specific survival, and multivariate stepwise regression analysis revealed that estimate of MNV was the only powerful predictor of prognosis (p = 0.0007). CONCLUSIONS: Our results indicate that estimate of MNV is an important predictor of prognosis for transitional cell carcinoma of the upper urinary tract. We recommend MNV estimate as a supportive method for subjective histological grading.

Age Factors↗
PubMed2000

Predicting pathological stage of localized prostate cancer using volume weighted mean nuclear volume.

PURPOSE: With the use of prostate specific antigen (PSA) and transrectal ultrasound guided biopsy of the prostate, increasing numbers of clinically localized prostate cancers have recently been detected. Presently, approximately 60% of men newly diagnosed with prostate cancer are believed to have organ confined disease but at the time of surgery less than 50% are ultimately found to have organ confined disease on final pathological analysis. Prediction of pathological stage before surgery using various prognostic factors is needed to determine whether radical prostatectomy is indicated. We have reported that estimates of volume weighted mean nuclear volume can accurately predict the prognosis of clinically localized prostate cancer treated with androgen ablation. In this study we examine whether estimates of mean nuclear volume can predict the pathological stage of cases treated with radical prostatectomy. MATERIALS AND METHODS: A retrospective, prognostic study of 52 patients with clinically localized prostate cancer (21 cases T1c, 27 T2, 4 T3) diagnosed at Kobe City General Hospital between January 1996 and December 1999 and treated with radical prostatectomy was performed. Unbiased estimates of mean nuclear volume measured from transrectal biopsy specimens were compared with PSA at diagnosis, clinical stage, estimated tumor volume and Gleason score with regard to prediction of pathological stage. RESULTS: Univariate analysis revealed that estimates of mean nuclear volume (p <0.0001), PSA at diagnosis (p = 0.0148) and estimated tumor volume (p = 0.0005) significantly correlated with pathological stage but Gleason score did not (p = 0.2011). In addition, multivariate logistic regression analysis demonstrated that estimates of mean nuclear volume (p = 0. 0073), PSA at diagnosis (p = 0.0277) and estimated tumor volume (p = 0.0197) were significantly independent predictors of pathological stage. CONCLUSIONS: The results of our study suggest that combining PSA and estimated tumor volume with estimates of mean nuclear volume can significantly contribute to the prediction of pathological stage of prostate cancer. We recommend use of these 3 factors to predict pathological stage of prostate cancer before surgery.

Aged↗
PubMed2000

Coronary artery bypass grafting in octogenarians.

The aging of the Japanese population and improvements in surgical techniques have resulted in an increasing number of elderly patients undergoing coronary artery bypass grafting (CABG). We reviewed the records of 11 patients 80 years of age or older (mean age 82+/-0.38 years, range, 80 to 85 years) who had undergone a CABG at our institution between August 1989 and February 1999. Eight patients were males and 3 were females. Preoperatively, 4 of 11 patients were categorized as New York Heart Association class II, 4 as class III, 3 as class II. The operations were elective in 8 cases, and emergent in 3. Three patients presented with neck and cerebrovascular disease. One patient experienced chronic renal failure. No patients died within 30 postoperative days and no in-hospital deaths occurred. A total of 11 were followed up for an average of 35+/-11 months (range, 1 to 105 months). One patient died due to unknown causes. There was a significant decrease in overall anginal symptoms after CABG among the survivors, with the average decrease being from NYHA class 3.1 to 1.5. In conclusion, CABG is a safe and effective surgical procedure in the treatment of octogenarians with heart disease.

Aged↗
PubMed1999

Androgen receptor CAG repeat length polymorphism in benign prostatic hyperplasia (BPH): correlation with adenoma growth.

BACKGROUND: The androgen receptor (AR) gene has a polymorphic CAG microsatellite encoding variable-length glutamine repeats in the AR protein. The purpose of this study was to evaluate the association between the growth of benign prostatic hyperplasia (BPH) and the AR gene CAG repeat length. METHODS: We determined CAG repeat lengths in 176 BPH patients who underwent simple prostatectomy and in 41 control subjects without benign prostatic enlargement (non-BPE group). RESULTS: A statistically significant (P < 0.02) trend for large adenoma size with short CAG repeat length was found among the adenoma quartiles. CAG repeat length in the fourth quartile (large adenoma, 21.5 +/- 2.7) was significantly shorter than in the first quartile (small adenoma, 23.3 +/- 2.1, P < 0.02). It tended to be shorter than in the non-BPE group (23.1 +/- 2.4), but CAG repeat lengths in the entire BPH (22.4 +/- 2.5) and non-BPE groups did not significantly differ. The relative risk of large BPH (the fourth quartile) was 2.75 (95% confidence interval, 1.05-7.24; P < 0.05) on comparing CAG repeats of < or = 22-> or = 23. CONCLUSIONS: Shorter CAG alleles may be a genetic factor that promotes the growth of BPH.

Aged↗
PubMed1999

An immunomodulatory arabinomannan extracted from Mycobacterium tuberculosis, Z-100, restores the balance of Th1/Th2 cell responses in tumor bearing mice.

The regulatory effect of Z-100 on the balance of Th1/Th2 cell responses in BALB/c mice bearing Meth-A fibrosarcoma was investigated. In tumor bearing mice, Th1 cytokine production (IL-2, IFN-gamma) are suppressed and Th2 cytokine production (IL-4, IL-10) are increased, as compared with those of normal mice. The administration of Z-100 (10 mg/kg) to tumor bearing mice restored the balance of Th1/Th2 cell responses from Th2 dominant state to the normal state. This regulatory effect of Z-100 was eliminated by depletion of adherent cells from splenocytes derived from tumor bearing mice, and by the treatment with 2-ClAdo (a macrophage inhibitor). Similarly, this regulatory effect was diminished by the treatment with anti-IL-12 mAb and anti-IFN-gamma mAb. In addition, the IL-12 p40 mRNA expression in splenic adherent cells and IFN-gamma mRNA expression in CD4+ T cells were increased by the administration of Z-100 to tumor bearing mice. These results suggested that Z-100 restored the balance of Th1/Th2 cell responses to the normal one in tumor bearing mice through the activation of macrophages and up-regulation of IL-12 production from macrophages and IFN-gamma production from CD4+ T cells.

Adjuvants, Immunologic↗
PubMed1999

A new planar multielectrode array for extracellular recording: application to hippocampal acute slice.

The present paper describes a new planar multielectrode array (the MED probe) and its electronics (the MED system) which perform electrophysiological studies on acute hippocampal slices. The MED probe has 64 planar microelectrodes, is covered with a non-toxic, uniform insulation layer, and is further coated with polyethylenimine and serum. The MED probe is shown to be appropriate for both stimulation and recording. In particular, multi-channel recordings of field EPSPs obtained by stimulating with a pair of planar microelectrodes were established for rat hippocampal acute slices. The recordings were stable for 6 h. Finally a spatial distribution of long-term potentiation was studied using the MED system.

Animals↗
PubMed1999

Simultaneous determination of residual tetracyclines in foods by high-performance liquid chromatography with atmospheric pressure chemical ionization tandem mass spectrometry.

We established a method for precisely determining residual tetracycline antibiotics (TCs) in foods by atmospheric pressure chemical ionization liquid chromatography-tandem mass spectrometry (APCI LC-MS-MS) using selected reaction monitoring with an internal standard. By setting the nebulizer probe temperature to 475 degrees C, we were able to use a mobile phase containing oxalic acid without clogging problems at the APCI interface, since oxalic acid decomposes to carbon dioxide and water at high temperature. DMCTC was very effective as an internal standard for determining TCs in various foods. TCs were cleaned up using a Bond Elut ENV cartridge and analysed by APCI LC-MS-MS. The recovery of TCs from various foods including animal tissues, honey, milk, eggs, and fish fortified at levels of 0.05, 0.10, and 0.50 ppm averaged 60.1-88.9%, with an RSD of 1.2-8.7%. The detection limits were 0.001 ppm for OTC and TC, 0.004 ppm for CTC, and 0.002 ppm for DC. The present method was also successfully used to determine TCs in swine kidney samples that were previously found by microbiological assay.

Animals↗
PubMed1999

Application of ion-exchange cartridge clean-up in food analysis. II. Determination of benzylpenicillin, phenoxymethylpenicillin, oxacillin, cloxacillin, nafcillin and dicloxacillin in meat using liquid chromatography with ultraviolet detection.

A multiresidue analytical method was developed for the simultaneous determination of benzylpenicillin (PCG), phenoxymethylpenicillin (PCV), oxacillin (MPIPC), cloxacillin (MCIPC), nafcillin (NFPC) and dicloxacillin (MDIPC) in meat. The method involves the use of an ion-exchange cartridge for sample clean-up followed by ion-pair high-performance liquid chromatography with ultraviolet detection. The recoveries of PCG, PCV, MPIPC, MCIPC, NFPC and MDIPC from pork muscle spiked at levels of 0.5, 0.1 and 0.05 mg/kg were in the range of 77-90, 73-95 and 80-93% with coefficients of variation of 0.5-1.7, 1.6-4.4 and 3.2-6.6%, respectively. For beef muscle spiked at levels of 0.5, 0.1 and 0.05 mg/kg, the recoveries of these compounds were 83-92, 71-86 and 77-90% with coefficients of variation of 1.7-4.4, 2.6-7.0 and 3.9-6.4%, respectively. The detection limits for each penicillin were 0.02 mg/kg in meat.

Animals↗
PubMed1999

Suppression of atherosclerotic development in Watanabe heritable hyperlipidemic rabbits treated with an oral antiallergic drug, tranilast.

BACKGROUND: Inflammatory and immunological responses of vascular cells have been shown to play a significant role in the progression of atheromatous formation. Tranilast [N-(3,4-dimethoxycinnamoyl) anthranillic acid] inhibits release of cytokines and chemical mediators from various cells, including macrophages, leading to suppression of inflammatory and immunological responses. This study tested whether tranilast may suppress atheromatous formation in Watanabe heritable hyperlipidemic (WHHL) rabbits. METHODS AND RESULTS: WHHL rabbits (2 months old) were given either 300 mg x kg-1 x d-1 of tranilast (Tranilast, n=12) or vehicle (Control, n=13) PO for 6 months. Tranilast treatment was found to suppress the aortic area covered with plaque. Immunohistochemical analysis showed that there was no difference in the percentage of the RAM11-positive macrophage area and the frequency of CD5-positive cells (T cells) in intimal plaques between Tranilast and Control. Major histocompatibility complex (MHC) class II expression in macrophages and interleukin-2 (IL-2) receptor expression in T cells, as markers of the immunological activation in these cells, was suppressed in atheromatous plaque by tranilast treatment. Flow cytometry analysis of isolated human and rabbit peripheral blood mononuclear cells showed that an increase in expression both of MHC class II antigen on monocytes by incubation with interferon-gamma and of IL-2 receptor on T cells by IL-2 was suppressed by the combined incubation with tranilast. CONCLUSIONS: The results indicate that tranilast suppresses atherosclerotic development partly through direct inhibition of immunological activation of monocytes/macrophages and T cells in the atheromatous plaque.

Administration, Oral↗