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Biomedical subjects

M Igawa

Publications and source records attributed to M Igawa.

At least 19 recordsLinked to original sources
PubMed2001

Alterations of beta- and gamma-catenin in N-butyl-N-(-4-hydroxybutyl)nitrosamine-induced murine bladder cancer.

Abnormal degradation of beta-catenin caused by alteration of the glycogen synthase kinase-3beta (GSK-3beta) consensus motif is an important step for carcinogenesis. We hypothesize that beta- and gamma-catenin may play an important role in the pathogenesis of bladder cancer. We tested this hypothesis through analysis of beta- and gamma-catenin in both murine and human bladder cancers. A murine bladder cancer model was prepared by use of N-butyl-N-(-4-hydroxybutyl)nitrosamine (BBN) in 6-week-old male B6D2F1 mice. After 4, 8, 12, 16, 20, 24, and 28 weeks of BBN treatment, bladder specimens were harvested and analyzed for both protein and gene expression for beta- and gamma-catenin. Mutational analysis of the NH(2)-terminal regulatory domains of beta- and gamma-catenin was performed in each specimen by PCR-single-strand conformational polymorphism (SSCP) analysis. Mutations were further confirmed by direct DNA sequencing with a dye terminator method. Human bladder cancer specimens with normal tissues, dysplasia, carcinoma in situ, and carcinoma of grades, 1, 2, and 3 were also analyzed for beta- and gamma-catenin expression. beta- and gamma-catenin were analyzed for mutations by SSCP and direct DNA sequencing. Intracellular accumulation of beta- and gamma-catenin was observed in 6 of 20 invasive carcinoma specimens. There was no intracellular accumulation of beta- and gamma-catenin in mucosal dysplasia, papillary or nodular dysplasia, and carcinoma in situ specimens. On an SSCP analysis for beta-catenin, abnormal bandshifts were detected in two invasive carcinomas with intracellular beta-catenin accumulation. Further sequencing revealed two mutations [AGT(S) to ATT(I) and TCT(S) to CCT(P)] within the consensus motif for GSK-3beta phosphorylation. On the other hand, SSCP analysis for gamma-catenin followed by sequencing revealed three mutations in two invasive carcinomas with intracellular accumulation of gamma-catenin. These three alterations affected the 3' downstream region outside the GSK-3beta phosphorylation site [ACC(T) to GCC(A), CTC(L) to ATC(I), and CTC(L) to ATG(M)]. In human bladder cancer, beta- and gamma-catenin expression was significantly weaker than in normal bladder. On SSCP analysis one abnormal bandshift was observed in high-grade human bladder cancer with intracellular beta-catenin accumulation. DNA sequencing revealed mutation TCT(S) to TGT(C). In summary, alterations in beta- and gamma-catenin are late events favoring tumor progression in mouse BBN-induced bladder cancer. Changes affecting the GSK-3beta phosphorylation site appear to be associated with activation of beta-catenin, but not with activation of gamma-catenin. In human blabber cancer, beta- and gamma-catenin expression is similar to the expression in the mouse model. The present study demonstrates that beta- and gamma-catenin may play an important role in bladder cancer progression.

Aged↗
PubMed2001

Multilocular spermatocele: a case report.

We describe a case of a multilocular spermatocele. Ultrasound examination revealed several cystic spaces at the head of the left epididymis. Epididymal tumor could not be excluded, and therefore surgical exploration was performed. Histopathological examination of the specimen revealed a multilocular spermatocele arising from the rete testis. Most spermatoceles remain small and rarely present marked clinical problems. but they are occasionally large, and may simulate a solid tumor.

Humans↗
PubMed2001

Activation of visual cortex in REM sleep measured by 24-channel NIRS imaging.

To visualize dreaming brain functions we studied hemodynamic changes in the visual cortex during the transition from non-rapid eye movement (NREM) to rapid eye movement (REM) sleep, using a 24-channel Near-Infrared Spectroscopy (NIRS) imaging method. Results were compared to the activation in visual cortex by visual stimulation during wakefulness. Subjects were four healthy males between 25 and 49 years of age. Five all-night polysomnographic and NIRS recordings were made. Increases in the oxygenated hemoglobin concentration in visual cortex were observed from nine of 14 REM periods. The activated areas were broader during REM sleep than during visual stimulation. These findings suggest that activation of visual cortex in REM sleep might represent dream-related brain activity.

Adult↗
PubMed2000

Concomitant presence of bladder cancer and neurogenic bladder in a patient with HTLV-1 carrier: a case report.

We describe a case of an HTLV-1 carrier who developed bladder cancer and neurogenic bladder. HTLV-1 is thought to alter host immune function and to contribute to the development of other malignancies. It is also sometimes reported that urinary symptoms precede pyramidal symptoms in patients with HAM. To our knowledge, concomitant presence of bladder cancer and neurogenic bladder in an HTLV-1 carrier has not been previously reported.

Carrier State↗
PubMed2000

The role of colour Doppler ultrasonography in detecting prostate cancer.

OBJECTIVE: To determine the usefulness of colour Doppler ultrasonography (CDUS) in detecting prostate cancer, by comparing CDUS with grey-scale transrectal ultrasonography (TRUS) and magnetic resonance imaging (MRI). PATIENTS AND METHODS: In all, 278 patients who underwent prostate biopsies because of an abnormal digital rectal examination, elevated prostate specific antigen levels, and/or abnormal TRUS between May 1998 and November 1999 were evaluated. The diagnostic accuracies of TRUS, CDUS, MRI and combinations of these imaging techniques in detecting prostate cancer were compared, based on the biopsy results. RESULTS: Carcinoma was detected in 233 of 1696 specimens, and 87 patients were diagnosed with prostate cancer. For each detected cancer site, the sensitivity of CDUS was lower than those of other imaging techniques, but CDUS had high a specificity and positive predictive value. The combination of grey-scale TRUS and CDUS or MRI improved the sensitivity and negative predictive value. The specificity and positive predictive value of the combination of grey-scale TRUS and MRI were less than those for grey-scale TRUS alone, while those for the combination of grey-scale TRUS and CDUS were higher than those for grey-scale TRUS alone. Five tumours were isoechoic but seen as hypervascular lesions with CDUS. CONCLUSION: CDUS provides information useful for detecting prostate cancer when used in combination with grey-scale TRUS, and should be included in the routine examination for prostate cancer.

Adenocarcinoma↗
PubMed2000

Pilsicainide for conversion and maintenance of sinus rhythm in chronic atrial fibrillation: a placebo-controlled, multicenter study.

BACKGROUND: Pilsicainide is a newly synthesized antiarrhythmic agent with class Ic properties. Various antiarrhythmic agents have been used to convert atrial fibrillation (AF) to sinus rhythm or decrease the rate of relapse of AF. METHODS: We randomly assigned 62 patients with chronic AF to oral treatment of either a placebo (10 patients) or 150 mg/day of pilsicainide (52 patients) for 4 weeks before electrical cardioversion. Before oral administration of pilsicainide, 41 patients underwent transesophageal echocardiography to investigate whether there was thrombus formation in the heart chambers. Patients without pharmacologic defibrillation underwent direct current cardioversion to restore sinus rhythm. After successful cardioversion, all patients continued to receive pilsicainide and were monitored for up to 2 years. RESULTS: Before cardioversion, 11 patients in the pilsicainide group (21%) reverted to sinus rhythm. No patients in the placebo group reverted to sinus rhythm. Direct current cardioversion was performed in 51 patients; however, 8 patients were not converted to sinus rhythm (5 patients receiving pilsicainide, 3 patients receiving placebo), and 3 patients needed intracardiac cardioversion to convert to sinus rhythm. Asymptomatic bradyarrhythmias were observed in 5 patients in the pilsicainide group. During the follow-up period, 33 patients (71%) in the pilsicainide group remained in sinus rhythm at 1 month; this number decreased to 23 patients (49%) at 3 months, 20 (43%) at 6 months, 16 (34%) at 12 months, 16 (34%) at 18 months, and 16 (34%) at 24 months. All patients receiving placebo continued to receive placebo after the cardioversion, and AF recurred a few days after cardioversion in all cases. No independent discriminant variables were identified in the groups between maintenance and nonmaintenance of sinus rhythm. Although no serious side effects regarding pilsicainide have been documented, one patient died of acute myocardial infarction, most likely not related to pilsicainide administration. CONCLUSIONS: Pilsicainide is effective in restoring or maintaining sinus rhythm in patients with chronic AF lasting longer than an average duration of 22 months. No major adverse effects were observed.

Administration, Oral↗
PubMed2000

Electrocardiographic characteristics of left ventricular outflow tract tachycardia.

Catheter ablation of idiopathic left ventricular outflow tract tachycardia (LVOT-VT) is rare because a safe ablation technique at this site has not been described, and serious complications may occur. This study compared the QRS morphology of LVOT-VT with that of idiopathic right ventricular outflow tract tachycardia. A comparison was made between the electrocardiographic characteristics of LVOT-VT originating from the supravalvular region of a coronary cusp (Supra-Ao group) with those of LVOT-VT originating from the infravalvular endocardial region of a coronary cusp of the aortic valve within the LV (Infra-Ao group). After precise mapping of the right ventricle, left ventricle, pulmonary artery, coronary cusps, and proximal portion of the anterior interventricular vein, there were 17 patients in whom VT was thought to be located at the LVOT by both activation and pace mapping. They were divided between a Supra-Ao group (n = 8), and an Infra-Ao group (n = 9). Analysis of the 12-lead electrocardiogram (ECG) revealed an S wave in lead I in all 17 patients. A precordial R wave transition was also observed at V1 or V2 in 16 patients (94%). In 7 of 8 patients (88%) with Supra-Ao LVOT-VT, no S wave was observed in either V5 or V6. In contrast, an Rs pattern was observed in both V5 and V6, or in V6 only, in 100% of the patients with Infra-Ao LVOT-VT. A LVOT-VT should be suspected when the ECG shows an S wave in lead I and an R/S ratio greater than 1 in lead V1 or V2, versus a coronary cusp location if there is no S wave in either lead V5 or V6.

Adolescent↗
PubMed2000

Activation of the visual cortex imaged by 24-channel near-infrared spectroscopy.

Near-infrared spectroscopy (NIRS) is a noninvasive technique for continuous monitoring of the amounts of total hemoglobin (total-Hb), oxygenated hemoglobin, (oxy-Hb) and deoxygenated hemoglobin (deoxy-Hb). The purpose of the present study was to demonstrate the utility of NIRS in functional imaging of the human visual cortex. A new NIRS imaging system enabled measurements from 24 scalp locations covering a 9 cm sq area. Topographic images were obtained from interpolations of the concentration changes between measurement points. Five healthy subjects between 25 and 49 years of age were investigated. After a resting baseline period of 50 s, the subjects were exposed to a visual stimulus for 20 s, followed by a 50 s resting period in a dimly lit, sound attenuating room. The visual stimulus was a circular, black and white, alternating checkerboard. In four of five subjects the visual cortex was the most activated area during visual stimulation. This is the first reported use of a NIRS-imaging system for assessing hemodynamic changes in the human visual cortex. The typical hemodynamic changes expected were observed; the total-Hb and oxy-Hb increased just after the start of stimulation and plateaued after 10 s of the stimulation period.

Adult↗
PubMed2000

Heat-induced cellular damage and tolerance in combination with adriamycin for the PC-3 prostate cancer cell line: relationships with cytotoxicity, reactive oxygen species and heat shock protein 70 expression.

OBJECTIVE: To analyze the relationships among the antitumor effect of chemothermotherapy, generation of reactive oxygen species (ROS), and expression of heat shock protein 70 (HSP-70) in the PC-3 prostate cancer cell line. MATERIALS AND METHODS: Changes in cell proliferation, cell cycle fractions, intracellular ROS accumulation and HSP-70 expression were examined after thermotherapy of PC-3 cells at 41, 42, 43 and 44 degrees C and/or simultaneous treatment with Adriamycin for 1 h, using the trypan blue dye exclusion method, flow cytometry, fluorescent 2', 7'-dichlorofluorescein (DCF) assay, and Western blot analysis. RESULTS: A significant decrease in the number of viable cells was observed with chemothermotherapy compared with thermotherapy at 42, 43, or 44 degrees C (p<0.05). DNA distribution histograms revealed cell accumulation in the S-G(2)/M phase after thermotherapy at 43 degrees C and after chemothermotherapy at 37, 41, 42 and 43 degrees C. After thermotherapy and chemothermotherapy at 44 degrees C, DNA histograms revealed no accumulation of cells with S-G(2)/M DNA content and cells exhibited a marked loss of viability. A significant increase in DCF production was observed with chemothermotherapy compared with thermotherapy at 42, 43 or 44 degrees C (p<0.05, p<0.01 and p<0.01, respectively). HSP-70 levels increased linearly with increasing temperature. HSP-70 levels after thermotherapy and chemothermotherapy increased with time and reached plateaus at 30 min, whereas the level after thermotherapy at 44 degrees C decreased at 60 min. CONCLUSIONS: In conclusion, one possible synergism in cytotoxic effects of chemothermotherapy and Adriamycin could be evaluated by the relationship between ROS accumulation and HSP-70 expression in the PC-3 prostate cancer cell line.

Antineoplastic Agents↗
PubMed2000

Successful radiofrequency catheter ablation from the supravalvular region of the aortic valve in a patient with outflow tract ventricular tachycardia.

Outflow tract ventricular tachycardia (OT-VT) was successfully ablated from the right coronary cusp of the aortic valve. The 12-lead ECG was totally different from the typical right ventricular OT-VT because the R/S ratio in precordial lead V1 was equal to 1 and tall R waves in precordial leads V2-6 were seen. Radiofrequency energy application from the right coronary cusp of the aortic valve successfully ablated this VT without complications. Radiofrequency catheter ablation from the right coronary cusp of the aortic valve can be done safely and effectively.

Aged↗
PubMed1999

Sucrase-isomaltase and hexose transporter gene expressions are coordinately enhanced by dietary fructose in rat jejunum.

We previously demonstrated that the levels of mRNAs of both sucrase-isomaltase (SI) and sodium/D-glucose transporter (SGLT1) are modulated by dietary sucrose in the rat jejunum. In the present study, we investigated whether the transcription of the gene coding SI is regulated by certain types of monosaccharides. Force-feeding a fructose and sucrose diet, (40% energy as fructose or sucrose) gave rise to parallel increases in the transcripts of SI and intestinal hexose transporters (SGLT1, GLUT5, and GLUT2) within 12 h. Force-feeding a glycerol-containing diet also caused an enhancement of SI, SGLT1, and GLUT2 mRNA levels. However, feeding the diet containing glucose or alpha-methylglucoside generally did not increase the transcript levels of SI or the intestinal hexose transporters. Nuclear run-on assays revealed that fructose as well as sucrose increased the transcription of both SI and GLUT5 genes and that the transcription rates of these genes were unaffected by glucose. These results suggest that fructose (or a metabolite) is capable of increasing the mRNA levels of SI and hexose transporters in the small intestine and that transcriptional regulation might play a pivotal role in the carbohydrate-induced coordinate enhancement of SI and fructose transporter gene expression

Animals↗
PubMed1999

Clinical significance of mdm2 and p53 expression in bladder cancer. A comparison with cell proliferation and apoptosis.

BACKGROUND: Clinical significance of immunohistochemically detectable level of p53 protein has been reported, but with some limitation as a prognosticator of bladder cancer patients. Whether or not simultaneous evaluation of mdm2 and p53 expression in bladder cancer exceed the prognostic significance of conventional histological findings, cell proliferation markers and apoptotic parameters remains unclear. MATERIALS AND METHODS: The paraffin-embedded materials taken from 84 patients with transitional cell carcinoma of the bladder who were treated with total cystectomy were used in this study. Immunostainings of p53 protein, mdm2 protein and Ki67 antigen were performed using monoclonal antibodies (clone DO7, clone 1B10 and clone MIB1, respectively). In addition, the apoptotic cells were determined using a terminal deoxynucleotidyl transferase (TdT) mediated dUTP biotin nick end labeling (TUNEL) technique. The results were quantitatively evaluated using a CAS 200 Image Analyzer (Cell Analysis System, Elmhurst, Ill., USA) and were compared with histological findings and clinical course. RESULTS: The mean values of mdm2 expression, p53 immunoreactivity, Ki67 expression and apoptotic index were 19.2, 20.5, 22.4 and 0.96%, respectively. Histological grade and pT category were significantly positively correlated with 53 immunoreactivity (p < 0.05 and p < 0.05, respectively), Ki67 expression (p < 0.005 and p < 0.0001, respectively) and apoptotic index (p < 0.01 and p < 0.0001, respectively), while both were not correlated with mdm2 expression. Using univariate analysis, the prognostic relevance for both survival and disease progression was noted in histological grade, pT category, p53 expression, Ki67 index and apoptotic index, whereas it was not in mdm2 expression. However, when analyzing the simultaneous evaluation of mdm2 and p53 expression (mdm2-p53 category), the relationship of the mdm2-p53 category with Ki67 expression and apoptotic index showed a statistical significance and a borderline significance (p = 0.0085 and p = 0.0652, respectively). In addition, the patients with both mdm2(-) and p53(-) showed a significant better prognosis as compared with either counterpart of mdm2-p53 category (p < 0.05 for both). Multivariate analysis revealed only pT category and mdm2-p53 category as independent factors for both disease progression and survival. CONCLUSIONS: Clinical significance of simultaneous evaluation of mdm2 and p53 immunostaining proved to be superior over that of cell proliferation and/or apoptotic markers when elucidating the biological characteristics of bladder cancer.

Adult↗
PubMed1999

Traumatic dislocation of the testis.

We report on a patient having testis dislocated into the superficial crus caused by an accident on a fishing boat. On physical examination, the left hemiscrotum was empty, and a painful mass was palpable inside the left thigh. On sonography, the testis appeared to be normal. Magnetic resonance imaging showed that the mass was located between subcutaneous tissue and muscle layer of the thigh. Surgical intervention was performed, and the left testis was found within the subcutaneous tissue inside the thigh, with slight torsion of the spermatic cord. The testis was fixed in the left hemiscrotum. To our knowledge, traumatic dislocation of the testis into the superficial crus is rare, and only 2 cases have been reported.

Adult↗
PubMed1999

Inverted papilloma of the urinary bladder in a girl.

We report a case of inverted papilloma of the urinary bladder in a 10-year-old girl. She was referred to us with intermittent asymptomatic gross hematuria. A polypoid, pedunculated mass, which had a thin and long stalk, approximately 6 x 20 mm in diameter, was observed by cystscopic examination at the right paratrigone. The lesion was resected endoscopically. Histological findings were compatible with the trabecular type of inverted papilloma. There have been only 3 cases reported of inverted papilloma in children, and no report has previously been published concerning a girl. Since the biological potential of pediatric inverted papilloma remains unclear, we believe that our patient should undergo periodic and detailed urological examinations.

Child↗