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Biomedical subjects

Hiroshi Okada

Publications and source records attributed to Hiroshi Okada.

At least 19 recordsLinked to original sources
PubMed2006

Proportions of stroke subtypes among men and women > or =40 years of age in an urban Japanese city in 1992, 1997, and 2002.

BACKGROUND AND PURPOSE: Higher proportions of hemorrhagic stroke and lacunar infarction were reported in rural Japan compared with those in Western countries. We examined the relative proportions of stroke subtypes in an urban Japanese city where westernized lifestyles are more common than in rural areas. METHODS: Stroke registration was performed in 1992, 1997, and 2002 for residents > or =40 years of age who were admitted with acute strokes to all of the 10 hospitals with > or =90 beds in Yao City, Osaka, Japan. Strokes were classified as intraparenchymal hemorrhage, subarachnoid hemorrhage, or ischemic strokes (embolic infarction, large-artery occlusive infarction, lacunar infarction, and unclassified thrombotic infarction) by criteria using computed tomography or MRI. RESULTS: A total of 650 first-ever strokes were registered. The age-adjusted proportion of each stroke subtype was not significantly different among the 3 study periods in both men and women. Throughout the 3 periods, intraparenchymal hemorrhage, subarachnoid hemorrhage, and ischemic stroke accounted for 26%, 7%, and 65% in men, respectively. In women, the respective proportions were 29%, 21%, and 44%. The proportion of each subtype for total ischemic strokes was as follows: 51% to 61% lacunar infarction, 25% to 26% large-artery occlusive infarction, and 11% to 17% embolic infarction. CONCLUSIONS: Our study showed that hemorrhagic stroke represented a large proportion of all strokes, especially among women, and lacunar infarction was the most common subtype of ischemic stroke among both men and women in Yao City, which differed from findings in Western countries.

Adult↗
PubMed2006

Enumeration of bacterial cell numbers and detection of significant bacteriuria by use of a new flow cytometry-based device.

A new, automated flow cytometry-based urine bacterium analyzer (UBA) was developed. We assessed the UBA for linearity of measurement, reproducibility of results, carryover rate, and correlation of measured results with those determined by urine culture. We also evaluated its ability to screen urine samples for significant bacteriuria. The UBA showed excellent linearity and a minor carryover rate. Results from the UBA were highly reproducible, and in between-run precision assays, the coefficients of variation for the UBA results were smaller than those for the urine culture results. Two hundred seventy-three urine specimens from patients attending the outpatient clinics of two university-based hospitals were examined. The results for the UBA were compared with those for urine culture. The UBA detected significant bacteriuria with a sensitivity of 96.6%, a specificity of 79.9%, a positive predictive value of 57.0%, a negative predictive value of 98.8%, a false-positive rate of 15.8%, a false-negative rate of 0.7%, and an accuracy of 83.5%. These results were comparable to or better than those obtained with previously reported screening procedures. The UBA can perform accurate enumeration of bacterial cells automatically in 90 seconds and can be used for the screening of significant bacteriuria.

Bacteria↗
PubMed2006

Qualitative and quantitative analysis of phosphorylated ATM foci induced by low-dose ionizing radiation.

We examined the formation of phosphorylated ataxia telangiectasia mutated (ATM) foci in exponentially growing normal human diploid cells exposed to low doses of X rays. Phosphorylated ATM foci were detected immediately after irradiation, and the number of foci decreased as the time after irradiation increased. The kinetics of phosphorylated ATM foci was comparable to that of phosphorylated histone H2AX. We found that there were fewer spontaneous phosphorylated ATM foci than that phosphorylated histone H2AX foci. Notably, significant numbers of phosphorylated histone H2AX foci, but not phosphorylated ATM foci, were detected in the S-phase cells. The induction of foci showed a linear dose-response relationship with doses ranging for 10 mGy to 1 Gy, and the average number of phosphorylated ATM foci per gray was approximately 50. The average size of the foci was comparable for the cells irradiated with 20 mGy and 1 Gy, and there was no significant difference in the kinetics of disappearance of foci, indicating that DNA double-strand breaks are similarly recognized by DNA damage checkpoints and are repaired irrespective of the dose.

Ataxia Telangiectasia Mutated Proteins↗
PubMed2006

[Arterial injury associated with tension-free vaginal tape procedure successfully treated by radiological embolization: a case report].

A 75-year-old woman underwent a tension-free vaginal tape (TVT) procedure for urinary stress incontinence. The patient complained of lower abdominal pain, a feeling of lower abdominal distension and nausea three hours after the operation. In addition, systolic blood pressure decreased gradually to 80 mmHg. Enhanced computed tomography revealed a retropubic hematoma sized up to 16 cm X 12 cm X 11 cm and bleeding from a vessel running through the posterosuperior aspect of the pubic bone. Successively, arteriography was performed. The arteriogram also confirmed arterial injury, which was successfully treated by selective embolization using a gelatin sponge and pushable coils. Postoperative course was uneventful requiring neither blood transfusion nor surgical removal of the hematoma.

Aged↗
PubMed2005

Four pregnancies in nonmosaic Klinefelter's syndrome using cryopreserved-thawed testicular spermatozoa.

OBJECTIVE: To investigate feasibility of using cryopreserved-thawed testicular spermatozoa from patients with nonmosaic Klinefelter's syndrome for intracytoplasmic sperm injection (ICSI). DESIGN: Case report. SETTING: University-based hospital and IVF clinic. PATIENT(S): Six patients with nonmosaic Klinefelter's syndrome who underwent testicular sperm extraction for ICSI. INTERVENTION(S): Microdissection testicular sperm extraction (TESE) and ICSI. MAIN OUTCOME MEASURE(S): We compared results of ICSI using cryopreserved testicular spermatozoa with those previously reported in Klinefelter's syndrome and those in nonobstructive azoospermia patients using cryopreserved testicular spermatozoa at our institution with respect to embryo cleavage rate, implantation rate, and pregnancy outcome. RESULT(S): Four of six patient couples with successful microdissection TESE achieved pregnancy using cryopreserved-thawed testicular spermatozoa. One pregnancy resulted in early-pregnancy abortion, two in delivery of healthy singleton girls, and one delivery of a healthy singleton boy. CONCLUSION(S): Cryopreserved-thawed testicular spermatozoa can be used successfully for ICSI in patients with nonmosaic Klinefelter's syndrome.

Adult↗
PubMed2005

Age as a limiting factor for successful sperm retrieval in patients with nonmosaic Klinefelter's syndrome.

OBJECTIVE: To determine factors affecting successful sperm retrieval by testicular sperm extraction in patients with nonmosaic Klinefelter's syndrome. DESIGN: Medical record analysis for nonmosaic Klinefelter's syndrome patients who underwent testicular sperm extraction. SETTING: Three university-based tertiary centers. PATIENT(S): Fifty-one patients with nonobstructive azoospermia related to nonmosaic Klinefelter's syndrome. INTERVENTION(S): Testicular sperm extraction. MAIN OUTCOME MEASURE(S): Correlation of patient characteristics; serum concentrations of luteinizing hormone (LH), follicle-stimulating hormone (FSH), and testosterone (T); as well as testicular volume with success in testicular sperm extraction. RESULT(S): We succeeded in obtaining spermatozoa in 26 patients and failed in 25. Levels of LH, FSH, and T and testicular volume did not differ between patient groups defined by success and failure. Median ages for successful and failed testicular sperm extraction were 31 and 38 years, respectively (statistically significant difference). When we analyzed success rates of testicular sperm extraction between two patient groups (<35 and > or =35 years old), the percentage of successful recovery of spermatozoa decreased after the age of 35 years (statistically significant difference). CONCLUSION(S): Testicular sperm extraction should be recommended before the critical age of 35 years.

Adult↗
PubMed2005

[Gene therapy].

We selected bone-metastatic prostate cancer as the target form of recurrent prostate cancer and developed a suicide-gene therapy based on an adenovirus vector with an organ-specific osteocalcin promoter. Related clinical studies have already been conducted in the United States at the University of Virginia, where results so far have established the safety of this therapy. In the present paper, in addition to presenting the results of these gene-therapy studies from the basic research to the clinical stage, we discuss the clinical studies begun by our group in August 2003. In the 21st century, therapeutic systems in use are undergoing major changes. Gene therapy is likely to become an important therapeutic option in recurrent prostate cancer. In terms of theory and technology however, this form of treatment is still at a very immature stage of development. We look forward to evolution in this field to provide an established treatment for recurrent prostate cancer and are committed to actively continuing with the development of gene therapy through translational research.

Adenoviridae↗
PubMed2005

Estimation of contrast of refraction contrast imaging compared with absorption imaging-basic approach.

PURPOSE: We discuss the usefulness of the refraction contrast method using highly parallel X-rays as a new approach to minute lung cancer detection. The advantages of refraction contrast images are discussed in terms of contrast, and a comparison is made with absorption images. MATERIALS AND METHODS: We simulated refraction contrast imaging using globules with the density of water in air as models for minute lung cancer detection. The contrast intensified by bright and dark lines was compared on a globule with the contrast of absorption images. We adopted the Monte Carlo simulation to determine the strength of the profile curve of the photon counts at the detector. RESULTS: The obtained contrasts were more intense by two to three digits than those obtainable with the absorption contrast imaging method. CONCLUSION: The contrast in refraction contrast imaging was more intense than that obtainable with absorption contrast imaging. A two to three digit improvement in contrast means that it is possible to greatly reduce the exposure dose necessary for imaging. Therefore, it is expected to become possible to detect the interfaces of soft tissues, which are difficult to capture with conventional absorption imaging, at low dosages and high resolution.

Absorption↗
PubMed2005

Pathogen occurrence and antimicrobial susceptibility of urinary tract infection cases during a 20-year period (1983-2002) at a single institution in Japan.

Urinary tract infections are one of the most common infectious diseases diagnosed in outpatients as well as in hospitalized patients. Recently, urinary tract infections have become more complicated and difficult to treat. Therefore, the present study analyzed the occurrence and antimicrobial susceptibility of uropathogens isolated at Kobe University Hospital between 1983 and 2002. This study was performed with three patient groups: urology inpatients, urology outpatients, and inpatients of other departments. During the 20-year study period, we studied 15,925 urine isolates obtained from those patients who were diagnosed with urinary tract infection. Overall, Enterococcus faecalis was the most frequently isolated pathogen, followed by Pseudomonas aeruginosa and Escherichia coli. The frequency of Staphylococcus aureus increased over time, corresponding to an increase in the occurrence of methicillin-resistant S. aureus (MRSA). In addition, the rate of isolation of Serratia marcescens also increased over time, especially among patients with urinary tract catheters. Our results demonstrate that the uropathogens isolated at a single institution have shown a trend of increasing resistance to various classes of antimicrobial agents. In addition, serious problems should be anticipated in the treatment of multidrug-resistant P. aeruginosa, fluoroquinolone-resistant E. coli, and arbekacin-resistant MRSA.

Drug Resistance, Bacterial↗
PubMed2005

Ray tracing analysis of overlapping objects in refraction contrast imaging.

We simulated refraction contrast imaging in overlapping objects using the ray tracing method. The easiest case, in which two columnar objects (blood vessels) with a density of 1.0 [g/cm3], run at right angles in air, was calculated. For absorption, we performed simulation using the Snell law adapted to the object's boundary. A pair of bright and dark spot results from the interference of refracted X-rays where the blood vessels crossed. This has the possibility of increasing the visibility of the image.

Angiography↗
PubMed2004

A novel feature of structural variegation in leaves of the tropical plant Schismatoglottis calyptrata.

We report a novel feature of leaf variegation. As is often the case in tropical forest floor herbs, Schismatoglottis calyptrata leaves feature structural variegation. Examination of leaf anatomy in S. calyptrata revealed a novel feature of structural variegation, which was generated by variation in the spatial arrangement of the adaxial-most tip of the palisade cells. In fully green leaf parts, contact between the adaxial-most tip of the palisade cells and the cone-shaped base of the outer epidermis cells was tight, and palisade cells were arranged radially around each epidermal cell. In dull, grayish-green leaf parts, the contact was loose, and no particular spatial arrangement of palisade cells relative to epidermal cells was observed. This feature of structural variation could be disadvantageous for photosynthesis efficiency in view of the hypothesis that, for rainforest herbs, cone-shaped epidermal cells may function as lenses. However, the high frequency of leaf variegation of S. calyptrata in natural habits suggests that this structural variegation plays an unknown advantageous role.

Acanthaceae↗
PubMed2004

A cox-2 promoter-based replication-selective adenoviral vector to target the cox-2-expressing human bladder cancer cells.

PURPOSE: Cyclooxygenase-2 (Cox-2), an enzyme that catalyzes the synthesis of prostaglandins, is overexpressed in a variety of premalignant and malignant conditions, including urinary bladder cancer. In the present study, we examined the feasibility of using Cox-2 promoter-based replication-selective adenovirus for targeting bladder cancer cells that express Cox-2 transcriptional activity. EXPERIMENTAL DESIGN: A series of human cancer cell lines, including three bladder cancer cell lines (KK47, T24, and 5637), were evaluated for their Cox-2 and CAR (the Coxsackievirus and adenovirus receptor) mRNA expression levels by quantitative real-time PCR. AdE3-cox2-327, a replication-selective adenovirus in which the expression of E1a is controlled by the Cox-2 promoter, was generated, and its tissue-specific activity was tested in vitro and in vivo. RESULTS: Three bladder cancer cell lines express higher levels of Cox-2 mRNA than does the human prostate cancer cell line PC3, the primary cultured human benign prostatic fibroblast, PF cells, and the human colon cancer cell line Colo320. Relatively higher expression of CAR mRNA was detected in the KK47, 5637, respectively, and Colo320 than in the T24, PC-3, and PF cells. In vitro assays revealed significant growth suppression of both Cox-2- and CAR-expressing bladder cancer cells KK47 and 5637 in comparison with the other cells that lack Cox-2 expression and/or CAR expression. CONCLUSIONS: The present study demonstrated both specificity and efficacy of AdE3-cox2-327, a selectively replicated adenovirus, toward the Cox-2-expressing bladder cancer cells in vitro and in vivo. We also found that CAR expression in the target cancer cells is an important factor for the efficacy of selectively replicated adenovirus-based gene therapy.

Adenoviridae↗
PubMed2004

Cerebrospinal fluid interleukin 8 concentrations and the subsequent development of postherpetic neuralgia.

PURPOSE: Other than age, the risk factors for postherpetic neuralgia are not well established. We studied whether the concentration of interleukin 8 in the cerebrospinal fluid is associated with the risk of postherpetic neuralgia. METHODS: We enrolled 170 patients more than 50 years old who had a typical painful and nontrigeminal herpetic rash. Patients were treated with acyclovir; no corticosteroids were given. Cerebrospinal fluid was taken for analysis of interleukin 8 during and at full crusting of the herpetic rash. Age, sex, comorbid conditions, prodromal pain, localization and severity of herpetic rash, number of skin lesions, and degree of pain were recorded. We used multivariate logistic regression modeling to identify significant predictive factors. Receiver operating characteristic (ROC) curves were evaluated to determine the contribution of each factor. RESULTS: Six months after healing, 31 patients (18%) had postherpetic neuralgia; 27 patients still had it after 1 year. Only three variables-age (odds ratio [OR] = 2.7 per 10-year increase; 95% confidence interval [CI]: 1.2 to 6.2), acute pain (OR = 1.8 per unit increase in visual analog scale; 95% CI: 1.2 to 2.8), and interleukin 8 concentration in the cerebrospinal fluid at full crusting of the herpetic rash (OR = 1.6 per 20-microg/L increase; 95% CI: 1.3 to 2.0)-were significant predictors of postherpetic neuralgia at 1 year. Interleukin 8 concentration also had the highest area under the ROC curve at these evaluation points (P <0.001). CONCLUSION: Our results suggest that interleukin 8 concentration in the cerebrospinal fluid at full crusting of herpetic rash may be useful for identifying patients who are likely to develop intractable postherpetic neuralgia.

Aged↗
PubMed2004

Messenger RNA levels and enzyme activities of 5 alpha-reductase types 1 and 2 in human benign prostatic hyperplasia (BPH) tissue.

BACKGROUND: Benign prostatic hyperplasia (BPH) development requires testicular androgens and aging. The principle prostatic androgen is dihydrotestosterone (DHT). Testosterone is converted to DHT by the enzyme 5 alpha-reductase. Two distinct 5 alpha-reductase enzymes, types 1 and 2, have been identified. While some studies have suggested that type 2 isoenzyme predominates in the prostate, studies on the prostatic localization of the two isoenzymes are controversial. The purpose of this study was to determine the quantitative expressions of 5 alpha-reductase types 1 and 2 in BPH tissues. METHODS: We examined the localizations of types 1 and 2 isoenzymes in BPH tissues using immunohistochemical staining and a real-time quantitative RT-PCR assay using the TaqMan system. We measured the enzyme activities of types 1 and 2 at pH values of 7.5 and 5.0, respectively. RESULTS: Our immunohistochemical study showed that type 1 isoenzyme was expressed predominantly in epithelial cells, whereas type 2 isoenzyme was expressed in both stromal and epithelial cells. The real-time RT-PCR assay demonstrated that the copy numbers of type 1 isoenzyme mRNA were significantly higher than those of type 2 isoenzyme mRNA. There were significant associations between enzyme activity at pH 7.5 and type 1 isoenzyme mRNA expression, and between the activity at pH 5.0 and type 2 mRNA expressions. CONCLUSIONS: We demonstrated that 5 alpha-reductase type 1 had a specific enzyme activity in the prostate, which supports the hypothesis that the type 1 isoenzyme may play a significant role in maintaining prostate enlargement along with the type 2 isoenzyme.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed2004

Quantitative analysis of the levels of expression of muscarinic receptor subtype RNA in the detrusor muscle of patients with overactive bladder.

INTRODUCTION: Antimuscarinic drugs have frequently been used for the treatment for patients with an overactive bladder (OAB) and there have been many studies on the distribution of muscarinic receptor subtypes in the bladder. However, the distribution of muscarinic receptor subtypes in OAB patients has not been well investigated. In this study we investigated the distribution of muscarinic receptor subtypes with mRNA and protein expressions in patients with and without OAB, and investigated both the dome and trigone area. METHODS: Samples of bladder smooth muscle were obtained from 10 individuals, five patients with OAB and a non-OAB group consisting of five patients who received radical cystectomy. RESULTS: The M2 receptor was predominant, but there was no significant difference in the level of M2 expression between the groups in the dome area. M5 expression in the dome area was significantly higher in the OAB group than in the non-OAB group. In the trigone area, the level of M2 mRNA expression was the highest in the non-OAB group, and was significantly lower in the OAB group. The levels of M1 and M5 mRNA expression were also observed in samples obtained from the trigone area. CONCLUSION: The multiformity of the muscarinic receptor subtypes in human bladder smooth muscle was confirmed, and our results suggest that the efficacy of a given pharmacologic therapy differs from patient to patient.

Adult↗
PubMed2004

Quantitative detection of Escherichia coli from urine of patients with bacteriuria by real-time PCR.

INTRODUCTION: Compared with the classical urine culture method, PCR is more rapid, and can detect smaller numbers of bacteria, however it is inferior for quantification. Because of the lack of quantification in routine PCR, the meaning of a positive PCR test result has not been validated for all infections. We report on the development of a novel quantitative detection system for the urinary tract infection (UTI) Escherichia coli using real-time PCR. PATIENTS: We enrolled 200 patients with suspected bacteriuria. METHODS: The gene encoding the universal stress protein (uspA) was found to be highly specific for E. coli. We quantified the copy numbers of E. coli in the urine of patients with UTI by using a real-time PCR assay (the TaqMan system) targeting uspA genes in genomic DNAs isolated from urine samples (n=200). To evaluate the feasibility of this method, the results were compared with those of a standard urine culture. RESULTS: The incidence of positive urine cultures was 75% (150 of 200), and various doses of E. coli were detected in 84 of 150 specimens. The real-time PCR method also detected 84 cases of urinary infections of E. coli in the same specimens. Furthermore, the result of the quantification of E. coli using real-time PCR strongly correlated (r2=0.925) with the result of urine culture. CONCLUSION: Our results suggest that using quantitative-PCR means a faster and simpler diagnosis of E. coli urinary infection can be made compared with the traditional urine culture method.

Bacteriuria↗
PubMed2004

Serum testosterone levels in patients with nonmosaic Klinefelter syndrome after testicular sperm extraction for intracytoplasmic sperm injection.

We measured testosterone levels in 24 patients with nonmosaic Klinefelter syndrome before and at 6 and 12 months after conventional or microdissection testicular sperm extraction. Testosterone levels decreased after surgery by either technique, and they did not recover to baseline concentrations, even when using less invasive microdissection techniques.

Humans↗