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Biomedical subjects

K Okada

Publications and source records attributed to K Okada.

At least 307 records · Page 17Linked to original sources
PubMed1999

Comparison of nuclear morphometric results between needle biopsy and surgical specimens from patients with prostate cancer.

OBJECTIVES: To compare nuclear morphometric values and Gleason scores between biopsy and radical prostatectomy specimens in patients with clinically localized prostate cancer. METHODS: The mean nuclear area (MNA), volume-weighted mean nuclear volume (MNV), and form factor (FF) were measured on the 18-gauge needle biopsy and radical prostatectomy specimens of 25 patients with clinically localized prostate cancer. The correlation between biopsy and surgical specimens was investigated for MNA, MNV, FF, and Gleason scores. RESULTS: The average values for the MNA, MNV, and FF of the biopsy specimens (36.2 microm2, 366 microm3, and 0.86, respectively) were significantly smaller than those of the prostatectomy specimens (51.4 microm2, 646 microm3, and 0.91) by Student's paired t test. The Pearson correlation of morphometric parameters between the biopsy and surgical specimens was significant only for FF. A comparison of histologic grading between the biopsy and surgical specimens revealed identical Gleason scores in 32% and identical grades (on a three-grade system) in 68% of all the cases. CONCLUSIONS: Discrepant nuclear morphometric results were observed between biopsy and surgical specimens of localized prostate cancer. The reason for such differing results is unclear but may be caused by artifacts associated with tissue sampling and processing. It is recommended that data obtained by biopsy should be considered separately from that obtained from surgical specimens.

Aged↗
PubMed1999

Cerebrospinal fluid cytokine levels and dexamethasone therapy in bacterial meningitis.

OBJECTIVES: cerebrospinal fluid (CSF) levels of interleukin (IL)-1 beta and tumor necrosis factor (TNF) alpha were measured to assess the effect and application of dexamethasone (Dex) therapy for bacterial meningitis. METHODS: associations between clinical findings and CSF parameters were first investigated, and prognosis was compared between 25 patients with Dex and 12 without Dex therapy. RESULTS: patients with the presence of disturbed consciousness showed higher CSF levels of TNF alpha (mean: 3015 pg/ml) or protein (mean: 215 mg/dl) than those without it (both, P < 0.O5). Simultaneous increase of TNF alpha (> 1000 pg/ml) and protein (> 100 g/dl) was observed in 80%, of patients with profoundly disturbed consciousness. Patients with Dex therapy presented higher TNF alpha/protein levels at diagnosis than those without Dex therapy (P < 0.05). Despite worse conditions at diagnosis, only one of 14 Dex-treated patients whose initial CSF TNF alpha levels exceeded 1000 pg/ml developed deafness. On the other hand, two of four patients without Dex therapy who had the same TNF alpha level suffered from psychomotor retardation. The differences in the frequency of sequelae between those with and without Dex therapy were significant in patients showing high TNF alpha level (P < O.05), but not in those showing high CSF levels of IL-1 beta or protein. The logistic regression analysis indicated that high CSF protein level (P < O.0001), or no Dex therapy (P=0.0001) was the independent risk factor for sequelae. CONCLUSIONS: although the study number was small, our observations suggested that CSF TNF alpha/protein levels reflected the neurologic severity, and implied that early Dex therapy might be beneficial for patients with prominently high TNF alpha levels.

Adolescent↗
PubMed1999

Increased urinary levels of adrenomedullin in patients with cystitis.

In this study, we examined urinary levels of adrenomedullin (AM) in 18 healthy volunteers and 18 patients with cystitis. We also compared urinary levels of AM in 11 patients with cystitis before and after antibiotic treatment. Urinary AM concentrations were measured by a radioimmunoassay specific for human AM. Urinary AM levels in patients with cystitis were significantly elevated compared with those of healthy volunteers and correlated positively with the number of urine leukocytes. By antibiotic treatment, urinary AM levels significantly decreased as compared with before the treatment. By RNA blot analysis of AM transcript, we detected significant levels of AM mRNA in canine urinary bladder and ureter. Intravenous administration of lipopolysaccharide elevated the AM mRNA level in the urinary bladder. These data suggest that infection and inflammation stimulate AM production in the urinary tract, which results in increased urinary AM levels in patients with cystitis. Based on these results, it is deduced that AM participates in the pathophysiology of cystitis, and its urinary level could be used as an index of the degree of cystitis.

Adrenomedullin↗
PubMed1999

A positron emission tomography study of self-paced finger movements at different frequencies.

Regional cerebral blood flow was measured in six right-handed volunteers using positron emission tomography during tasks involving repetitive self-paced finger tapping at five different frequencies. The contralateral primary sensorimotor cortex, the pre-supplementary motor area and the cingulate motor area showed significant activation during self-paced finger tapping tasks, compared with the resting state. A positive correlation between the regional cerebral blood flow and the movement frequency was found only in the primary sensorimotor cortex. In the pre-supplementary motor area and the cingulate motor area, however, activity increased when the subject employed movement frequencies faster or slower than his own pace. The same tendency was noted with respect to the relative variability of the inter-tapping interval. The results therefore indicate that the activity of the pre-supplementary motor area and the cingulate motor area may well be related to the increased difficulty in motor control rather than to the execution of the movement itself.

Adolescent↗
PubMed1999

Fast and slow recovery phases of goldfish behavior after transection of the optic nerve revealed by a computer image processing system.

As the goldfish is a common experimental animal for vision research, including psychophysical behavior, it is very important to quantitatively score fish behavior. We have previously developed a computer image processing system which can acquire the positional coordinates of goldfish moving freely in an aquarium and determine turning directions (go straight, right or left turn). In the present study, an algorithm to determine tilting angles of moving goldfish was constructed. We also made histograms for quantifying the interaction between pairs of goldfish (two-point distance). By using these histograms, we estimated the time-course of behavioral regeneration after optic nerve transection in goldfish. Control goldfish showed an equal percentage of right or left turns and maintained an upright position in a dorsoventral axis. When the optic nerve of a goldfish was unilaterally sectioned, the goldfish showed predominant turning and slight tilting toward the intact eye. The abnormal turning and tilting behaviors lasted for 10-14 days and then gradually decreased, returning to control behaviors by one month after the unilateral transection. When the optic nerve of a single goldfish was bilaterally sectioned, it did not show any preferential turning and tilting behavior, which is similar to what was observed in control goldfish. However, the trace maps showed that, after bilateral sectioning, fish preferred to cross the center of the tank, which was unlike control fish. In control pairs, one goldfish chased the other with a fixed small range of two-point distances. However, in pairs of goldfish with bilateral transection of the optic nerve, the blind goldfish behaved independently of each other, with a long two-point distance. The long two-point distance of the blind goldfish lasted for at least two months and then slowly returned to control two-point distance by four months after bilateral transection. Such fast and slow recovery in goldfish behaviors evoked after unilateral and bilateral transection of the optic nerve is discussed with respect to reconnection of regenerating optic nerves in the fish central nervous system. This computer image processing system is a useful tool with which we can quickly and easily quantify fish behavior.

Algorithms↗
PubMed1999

Clinical application of diadenosine tetraphosphate (Ap4A:F-1500) for controlled hypotension.

BACKGROUND: In our animal study, it was revealed that diadenosine tetraphosphate (Ap4A:F-1500) has a dose-dependent hypotension effect of up to 60% decrease in mean arterial pressure compared to control value. Furthermore, in healthy male volunteers, the safety of Ap4A up to 4 mg.min-1 was confirmed. In patients who require surgical procedures under general anesthesia together with controlled hypotension, hypotension was induced by Ap4A in order to examine its hypotensive effect and modulating action on the blood pressure. METHODS: Ten patients who required controlled hypotension and who were scheduled for elective surgery under general anesthesia were studied. Anesthesia was maintained with isoflurane (n = 7) or sevoflurane (n = 3) in oxygen-nitrous oxide. Controlled hypotension was induced by Ap4A administered at a rate of 10-20 micrograms.kg-1.min-1. The dose was adjusted at a maximum rate of 80 micrograms.kg-1.min-1 until the target blood pressure was achieved. Arterial blood pressure and heart rate were monitored. Arterial samples were drawn at 4 separate time points to measure the concentration of Ap4A in the plasma. RESULTS: The time required for attaining the target blood pressure after initiation of Ap4A infusion was about 16 min, and the time lapse between withdrawal of infusion to recovery of blood pressure was about 18 min. No reflex tachycardia was observed during infusion of Ap4A and no rebound hypertension was evident after withdrawal. The plasma Ap4A concentration increased in response to the acceleration rate of Ap4A administration with a tendency of augmented hypotensive effect. CONCLUSION: As it produces an excellent hypotensive effect together with a modulating action on blood pressure, Ap4A was assessed as useful in producing controlled hypotension.

Adult↗
PubMed1999

Fibroma of tendon sheath arising from the radio-ulnar joint.

A report of a 65-year-old male with a tumor arising from synovial tissue of the radio-ulnar joint. On magnetic resonance imaging, the tumor was demonstrated as a heterogeneous and lobulated mass with a low signal intensity both in T1- and T2-weighted images. Histological findings of the tumor were identical to those of fibroma of the tendon sheath. In the peripheral villous synovial tissue, several small and fibrous nodules were observed, and their histological features were identical to those of the main tumor. Immunohistochemically, the tumor cells showed diffuse and intense reactivity to vimentin, muscle actin and S-100. These results indicated that the tumor might be a fibromatous analog of synovial chondromatosis.

Actins↗
PubMed1999

Early results of radical prostatectomy and adjuvant endocrine therapy for prostate cancer with or without preoperative androgen deprivation. The Prostate Cancer Study Group.

BACKGROUND: The effects of preoperative androgen deprivation were explored in the patients who received radical prostatectomy and subsequent adjuvant endocrine therapy for prostate cancer. METHODS: Stage A2, B or C prostate cancers were randomized to one of two groups: (i) group I (n=90), who received androgen deprivation (leuploride and chlormadinone acetate) for 3 months preoperatively followed by radical prostatectomy and adjuvant endocrine therapy (leuploride only); and (ii) group II (n=86), who underwent the surgery followed by 3 month androgen deprivation and subsequent adjuvant endocrine therapy. The effects of preoperative androgen deprivation on clinical relapse (serum prostate specific antigen (PSA) > 1.98 ng/mL, local recurrence or distant metastasis) and PSA relapse (PSA >0.2ng/mL) were evaluated at 2 years after randomization. RESULTS: There was no significant difference in clinical or PSA relapse-free survival and quality of life measures between the two groups, although relapses occurred significantly more frequently in patients who had more advanced stages, higher pretreatment PSA values or lower histologic differentiation in either group. Subgroup analysis indicated that clinical relapse-free survival in stage C cancer tended to be better in patients with preoperative androgen deprivation than in those patients without it (P< 0.1). CONCLUSIONS: Preoperative androgen deprivation may be beneficial for stage C prostate cancer patients receiving radical prostatectomy and adjuvant endocrine therapy over the 2 year observation period. A longer follow up is needed to clarify the exact extent of benefit in terms of survival and quality of life.

Aged↗
PubMed1999

Characterization of ureteral lesions associated with impacted stones.

BACKGROUND: Few studies have addressed the various types of ureteral lesions apparent in patients treated for ureteral stones, especially in those with impacted stones. Macroscopic and microscopic analyses of ureteral lesions associated with impacted stones were therefore undertaken. METHODS: From May 1994 to October 1996, 36 patients with ureteral stones, 21 of whom showed stone impaction, were treated with transurethral ureterolithotripsy. After ureteroscopic examination, biopsied specimens were obtained from six patients with impacted stones and were examined microscopically by conventional hematoxylin and eosin staining. RESULTS: Ureteroscopy revealed two types of mucosal lesions in the patients with impacted stones: Type 1 lesions were defined as edematous or cystic hemispheric lesions and occurred in 18 patients, whereas type 2 lesions had a villous appearance and were present in three patients. Microscopically, type 1 lesions appeared as submucosal edema without specific findings, whereas type 2 lesions appeared as columnar mesenchymal tissue coated with several layers of transitional epithelium. With regard to factors that might contribute to lesion formation, duration of stone presence was significantly greater for patients with impacted stones than for those with-non-impacted stones. However, no differences in such parameters were apparent between patients with type 1 lesions and those with type 2 lesions. CONCLUSIONS: Two types of ureteral lesions associated with impacted stones were confirmed microscopically. The duration of stone presence is a potential contributing factor in the development of ureteral lesions, but factors that determine the type of ureteral lesion remain unclear.

Adult↗
PubMed1999

Ratio of gamma-seminoprotein to prostate-specific antigen for the detection of prostate cancer: its discrimination power could be influenced by the assay methods of PSA and/or gamma-seminoprotein.

BACKGROUND: The ratio of gamma-seminoprotein (gamma-Sm) and prostate-specific antigen (PSA) has been regarded as being superior over PSA alone as a discriminator between prostate cancer and benign prostatic diseases. In previous studies, PSA and gamma-Sm were measured by the Eiken kit and the old-version or revised Chugai kit, respectively. We compared the power of gamma-Sm ratio with that of PSA alone when using Markit-M PSA assay and the revised Chugai gamma-Sm assay. METHODS: Fifty-three patients with prostate cancer having no metastasis and 116 with benign prostatic diseases were enrolled in this study. Prostate-specific antigen was measured by Markit-M kit and gamma-Sm was measured by the revised Chugai kit. The discrimination power of gamma-Sm ratio and PSA alone was evaluated with receiver operating characteristic (ROC) curves. Comparisons between prostate cancer and benign diseases were performed with Mann Whitney U-test and Fisher's exact test. RESULTS: The optimal cut-off value was set at 3.1 ng/mL for PSA and 0.935 for gamma-Sm ratio. Sensitivity, specificity and positive predictive value of PSA alone were 81.1, 81.0 and 66.2%, respectively, while those of gamma-Sm ratio were 73.6, 90.5 and 78.0%, respectively. There was no statistical significance in each value between PSA and gamma-Sm ratio. Areas under the ROC curves of PSA and gamma-Sm ratio were 0.881 and 0.866, respectively (P>0.05). CONCLUSION: Contrary to the previous reports, gamma-Sm ratio and PSA were not different in the discrimination between prostate cancer and benign prostatic diseases, which suggested that the discrimination power of gamma-Sm ratio, and presumably that of the free PSA to total PSA ratio as well, could be considerably influenced by the assay kits for serum PSA and/or gamma-Sm (free PSA) used. Therefore, the clinical significance of gamma-Sm ratio should be evaluated for each PSA assay kit.

Biomarkers, Tumor↗
PubMed1999

Prognostic value of sarcomatoid histology and volume-weighted mean nuclear volume in renal cell carcinoma.

OBJECTIVE: To determine the prognostic value of two histopathological factors, sarcomatoid histology and volume-weighted mean nuclear volume (MNV) in renal cell carcinoma (RCC). PATIENTS AND METHODS: The study included 106 patients (72 men and 34 women, mean age 63 years, range 32-83) with RCC, all of whom were surgically treated between 1985 and 1995. The presence of any sarcomatoid component was determined and MNV estimated using a stereological method in histological slides of tumour specimens from these patients. The prognostic significance of the two variables was evaluated by univariate and multivariate analyses in comparison with other histopathological variables (T, N and M categories, nuclear grade, tumour size, tumour type), using the cause-specific and progression-free survival of the patients as the endpoints. RESULTS: Among the 106 RCC cases examined, a sarcomatoid component was detected in 34 (32%); the MNV was 90-627 micro3 (mean 225). By univariate and multivariate analysis, both variables were significant prognostic factors for cause-specific survival in all patients. In addition, multivariate analysis of the 74 patients with localized RCCs (T1-3, N0 M0) showed that sarcomatoid histology was a significant prognostic factor for disease progression. CONCLUSION: The presence of sarcomatoid histology and the MNV, both of which can be examined with no specialized laboratory procedures, seem to be useful tumour-related prognostic factors in RCC.

Adult↗
PubMed1999

Impact of cigarette smoking on the incidence of Type 2 diabetes mellitus in middle-aged Japanese men: the Osaka Health Survey.

AIMS: To assess the impact of cigarette smoking on the incidence of Type 2 diabetes mellitus (DM) in middle-aged Japanese men. METHODS: The study enrolled 6250 men aged 35-60 years and free of diabetes, impaired fasting glucose and hypertension at entry. Type 2 DM was defined by a fasting plasma glucose level > or =7.0 mmol/l or physician-diagnosed Type 2DM. RESULTS: Four hundred and fifty cases of Type 2 DM were confirmed during the 60904 person-years follow-up. After adjustment for multiple covariates, including age, body mass index, alcohol consumption, physical activity, parental history of diabetes and the level of fasting plasma glucose, total cholesterol, triglycerides, high-density lipoprotein cholesterol and haematocrit, the relative risk of Type 2 DM among current smokers compared with non-smokers was 1.47 (95% confidence interval (CI) 1.14-1.92). Men who smoked >30 cigarettes/day had a multivariate-relative risk of 1.73 (95% CI 1.20-2.48) compared with non-smokers. The number of cigarettes smoked daily and the pack-year values were positively related to the development of Type 2 DM in a dose-dependent manner (P for trends = 0.0026 and 0.001, respectively). CONCLUSIONS: A cigarette smoking habit is an independent risk factor for Type 2 DM.

Adult↗
PubMed1999

Aldosterone activates Na+/H+ exchange in vascular smooth muscle cells by nongenomic and genomic mechanisms.

BACKGROUND: In vascular smooth muscle cells (VSMCs), Na+/H+ exchange (NHE) plays an important role in intracellular pH (pHi) regulation. Recently, nongenomic effect of aldosterone (ALDO) on NHE activity has been suggested in VSMCs. However, the nongenomic and genomic effects of ALDO on NHE and the intracellular signaling mechanisms for these effects have not fully been determined in VSMCs. METHODS: The effects of short- (3 hr) and long- (24 hr) term exposure to ALDO on NHE activity were examined in cultured VSMCs from rat thoracic aortae by using single-cell pHi measurement with the pH-sensitive dye 2'7'-bis(carboxyethyl)-5(6)-carboxyfluorescein. The NHE activity was calculated from the initial rate of Na+-dependent pHi recovery after acid load. RESULTS: The NHE activity significantly increased after short- and long-term exposure of VSMCs to ALDO (10(-6) M). The inhibitors of gene transcription (actinomycin D) and of protein synthesis (cycloheximide) had no effect on the short-term ALDO effect, but inhibited the long-term ALDO effect. The antagonists of the mineralocorticoid receptor (MR) (spironolactone) and of the glucocorticoid receptor (GR) (RU38486) caused no effect on the short-term ALDO effect, but inhibited the long-term ALDO effect. Two protein kinase C (PKC) inhibitors (staurosporine A and calphostin C) and PKC down-regulation (24 hr pre-exposure to phobol 12-myristate 13-acetate, PMA) inhibited both the short- and long-term ALDO effects. Exposure of VSMCs to PMA for 3 hours mimicked the short-term effect of ALDO on NHE activity. ALDO significantly increased PKC activity in VSMCs. The short-term ALDO effect was inhibited by disruptors of microtubule (colchicine) and of filamentous-actin (cytochalasin B). Long-term exposure of ALDO caused a threefold increase in NHE (NHE-1) mRNA levels. CONCLUSIONS: The short-term effect of ALDO on NHE activity is not mediated through either MR or GR, occurs independent of gene transcription and protein synthesis, and occurs through a mechanism involving the structural elements of cytoskeleton. The long-term effect of ALDO on NHE activity occurs through both MR and GR and requires gene transcription and protein synthesis. Both short- and long-term effects of ALDO are mediated through PKC activation. Therefore, ALDO activates NHE by nongenomic and genomic mechanisms in VSMCs.

Aldosterone↗
PubMed1999

Distribution of T-lymphocyte subpopulation in blood and spleen of normal cattle and cattle with enzootic bovine leukosis.

Immunocytochemical and flow cytometry techniques were used to examine T-lymphocyte subpopulations in peripheral blood lymphocytes (PBLs) and spleen from cases of enzootic bovine leukosis (EBL) in adult cattle, and from normal cattle (adult and young), with a panel of monoclonal antibodies against bovine leucocyte differentiation molecules. Both in PBLs and spleen, the percentages of T-lymphocyte subpopulations (CD3+, CD4+, CD8+, and WC1 + gamma delta T lymphocytes) of EBL-affected and normal adult cattle were significantly lower than those of normal young cattle. The percentages of these T-lymphocyte subpopulations in the PBLs of adult cattle with EBL were lower than those of normal adult cattle, but the converse was true in the spleen. It is suggested that tumour immunity occurred in the spleen. Histological examination revealed no follicular hyperplasia in the spleen, and the proliferation of neoplastic cells began in the red pulp. It is concluded that the spleen is not the organ initially responsible for the transformation of EBL lymphoma and that neoplastic cells migrating from peripheral blood are metastatic.

Age Factors↗
PubMed1999

Low risk of TT virus (TTV) infection in medical workers.

The rate of infection with TT virus (TTV), a novel single-strand DNA virus was evaluated and the clinical and laboratory features in affected Japanese medical workers were analysed. TTV DNA was measured in 356 medical workers and in 150 age-matched controls using a seminested polymerase chain reaction. TTV DNA was detected in 62 of 356 medical workers (17.4%). There were no differences in the prevalence of TTV infection between medical workers and controls (18.9%) and in the characteristics of medical workers with TTV infection and medical workers without it, except that the mean age of patients with TTV infection was higher than that of patients without TTV. The medical workers were drawn from three groups: medical doctors, nurses and clinical laboratory technicians. There was no statistically significant difference between the rate of TTV infection in the three groups. These findings suggest that the risk of TTV infection in medical workers is low and not related to liver dysfunction.

Adult↗
PubMed1999

The increased accumulation of [18F]fluorodeoxyglucose in untreated prostate cancer.

BACKGROUND: To evaluate the clinical usefulness of [18F]fluorodeoxyglucose positron emission tomography (FDG-PET) compared with histopathological grading, clinical stage and serum prostatic specific antigen (PSA) level in the detection and characterization of prostate cancer. METHODS: Forty-four patients with histologically proven prostate cancer and five control subjects with benign prostatic hyperplasia (BPH) were prospectively investigated with FDG-PET prior to treatment. RESULTS: By visual inspection, FDG accumulation was positive in 28 patients with prostate cancer (sensitivity 64%), whereas all were negative in the control group. FDG-PET in three patients with lymph node metastases did not show any high intrapelvic accumulations corresponding to metastatic sites. Among 12 patients with multiple bone metastases which were detected with 99m-HMDP bone scintigraphy, nine (75%) showed moderate to high FDG accumulation at the sites of bone metastases. Quantitatively, FDG accumulation in prostate cancer was significantly higher than in BPH and there was a tendency for FDG uptake of tumors to be higher with higher histological Gleason grades. Furthermore, FDG uptake in tumors with lymph node and/or bone metastasis was significantly higher than that of localized stages. However, the correlation between PSA and FDG uptake in the prostate cancer was very weak for clinical relevance. CONCLUSIONS: Although FDG-PET was not sensitive enough to detect prostate cancer in clinical use, it is suggested that glucose metabolism in prostate cancer tended to be higher in patients with tumors of advanced stages.

Aged↗
PubMed1999

Long-term treatment results of elderly patients with prostate cancer in Japan: an analysis of prognostic factors.

BACKGROUND: The management of elderly patients with prostate cancer is an important issue because the incidence of prostate cancer is high in old men, and people are also living longer today. The present retrospective study was therefore conducted to evaluate the long-term clinical outcome of elderly patients with prostate cancer and to analyze the prognostic factors. METHODS: Between 1980 and 1992, 151 patients aged 75 to 89 years old were diagnosed as having prostate cancer. The patients were initially managed by hormonal therapy in 117, radical prostatectomy in 11, external radiotherapy in 20, chemotherapy in 1 and no treatment in 2 cases. The clinical outcome of the patients was analyzed in relation to clinical stage, histological grade and treatment methods received. RESULTS: By univariate analysis, the stage and treatment methods were significant variables for overall and cause-specific survival rates, and grade was a significant variable for cause-specific survival rate of the patients. However, multivariate analysis revealed that stage was the only independent prognostic factor for overall as well as cause-specific survival of the patients. Among the patients with stage A2-B disease, a comparison between those treated definitively and non-definitively revealed no difference in terms of overall and relative survival rates. CONCLUSIONS: The presence of advanced prostate cancer disease had the greatest impact on the survival of the elderly patients. On the other hand, localized prostate cancer was satisfactorily managed with non-definitive almost as well as with definitive treatment.

Aged↗