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Biomedical subjects

S Satake

Publications and source records attributed to S Satake.

At least 55 records · Page 3Linked to original sources
PubMed1998

Alternation in the flutter wave morphology during radiofrequency catheter ablation for common atrial flutter.

A linear lesion created at the right atrial isthmus by radiofrequency current application can successfully eliminate common atrial flutter (AF). The mechanism of unsuccessful cases has not yet been well delineated. This study sought to investigate the cause of unsuccessful cases of radiofrequency catheter ablation of AF. Sixty-six patients with refractory common AF were referred for radiofrequency catheter ablation. Radiofrequency current was applied to the right atrial isthmus between the inferior vena cava and tricuspid annulus or between the coronary sinus orifice and tricuspid annulus. In 5 (8%) of the 66 patients, a morphological change of the flutter wave was observed in the 12-lead ECG concomitant with the change of the atrial excitation sequence during the delivery of radiofrequency energy without the termination of atrial flutter. In 8 (12%) patients, the morphology of the new AF wave, which was provoked electrically after the termination of the original AF, was different, and the average flutter cycle length also differed in 3 cases (2%). The results of radiofrequency application could be misinterpreted as unsuccessful when the occurrence of another, different type of AF has been overlooked following the elimination of the original AF during the radiofrequency catheter ablation procedure. It is possible that the flutter circuit can take an alternative pathway despite the complete conduction block at the right atrial isthmus.

Adult↗
PubMed1998

[Survival in patients with clear cell carcinoma of the ovary].

Thirty-one patients with clear cell ovarian carcinoma who underwent primary surgery and postoperative therapy were retrospectively evaluated. Eighteen patients (58%) had International Federation of Gynecology and Obstetrics (FIGO) stage I disease, 3 patients (9.7%) stage II disease, and 10 patients (32.3%) stage III and IV disease. Patients with stage III and IV disease demonstrated a significantly poor prognosis compared with patients who had stage I or II disease (p < 0.01). No patients with stage III and IV disease survived 5 years. p53 protein expression and proliferative activity (PA) were studied by immunohistochemical methods using p53 molecule and antibodies to PCNA (proliferative cell nuclear antigen). Intranuclear accumulations of p53 product were observed in 15 of 31 (48.4%). On the other hand, 15 of 31 (48.4%) patients stained positively for PCNA (> or = 60% of cancer cells stained positively). Positive p53 staining and highly PA were associated with poor survival. Two patients with stage I a relapsed were positive p53 and highly PA. Accordingly, consolidation chemotherapy is necessary for patients with stage I a who are positive p53 and highly PA. Platinum-based chemotherapy for patients who had minimal residual tumor was effective, but 5 patients who had > or = 2 cm tumor burden were not effective at all. The response rate for platinum-based chemotherapy was 20% (1/5) among p53 positive, in contrast to 66.7% (4/6) among p53 negative patients. So it seems that p53 positive patients are chemoresistant.

Adenocarcinoma, Clear Cell↗
PubMed1997

Radiofrequency ablation of tachyarrhythmias in patients with Ebstein's anomaly.

We performed radiofrequency catheter ablation in five patients associated with Ebstein's anomaly to cure their refractory tachyarrhythmias. The presenting arrhythmias were four cases of orthodromic circus movement tachycardia using accessory pathways as a requisite limb, including one case of a Mahaim fiber and one of atrial flutter of common variety. All accessory pathways, including the Mahaim fiber, were ablated by RF energy delivered through the catheter placed at the AV annulus rather than the displaced anatomical AV groove. Interestingly, the antegrade or retrograde conduction interval over these accessory pathways was relatively longer than that of usual accessory pathways, and the accessory pathway potential was fractionated in some cases. The location of the atrioventricular node was displaced from the usual position to the postero-inferior area of Koch's triangle in one case. The configuration of the flutter wave was larger than usual in height as well as in width. All tachyarrhythmias were cured by RF catheter ablation. In the case of RF catheter ablation for patients with Ebstein's anomaly, close attention is indispensable in order to accomplish it safely and successfully, because of the anatomical and functional differences peculiar to Ebstein's anomaly.

Cardiac Catheterization↗
PubMed1997

Lack of a point mutation of human DNA topoisomerase II in multidrug-resistant anaplastic thyroid carcinoma cell lines.

DNA topoisomerases are major defined targets for a large variety of clinically important anticancer agents, including etoposide, adriamycin, and mitoxantrone. Mutations at amino acids 439, 450 and 803 of DNA topoisomerase II were examined in multiple anticancer drug-resistant anaplastic thyroid carcinomas (ten cell lines and three cancerous tissues) by reverse transcriptase-polymerase chain reaction (RT-PCR) and subsequent DNA sequencing. No mutation was found in these cell lines and tissues, but mdr1, mrp and/or lrp mRNA were expressed to a varying degree, and there was no significant difference in DNA topoisomerase IIalpha content among the cell lines and tissues as evaluated by Western blotting. Our experimental data indicate that overexpression of multidrug resistance-related mRNA is sufficient to confer drug resistance.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1997

Application of telomerase assay for the screening of cervical lesions.

Telomerase is a ribonucleoprotein that synthesizes telomeric DNA onto chromosomal ends. The expression of telomerase is thought to be required for cellular immortality and oncogenesis. Telomerase activity has been detected not only in most cancers but also in some types of premalignant lesions, such as squamous intraepithelial lesions (SILs). In the present study, we used the telomerase assay to detect uterine cervical lesions in cervical scraping samples. A total of 82 cervical scraping samples were obtained from women with or without cervical lesions and examined by nonradioisotope telomeric repeat amplification protocol assay. Fifteen of 17 (88%) cervical cancer specimens exhibited telomerase activity, whereas 5 of 8 (63%) and 14 of 24 (58%) specimens from low-grade and high-grade SILs, respectively, also exhibited telomerase activity. In contrast, 3 of 33 (9%) specimens from normal cervices exhibited telomerase activity. Dilution telomeric repeat amplification protocol assay was performed to estimate telomerase activity; it revealed that high levels of activity were often expressed in cervical cancer. Cytological examination was also performed by Pap smear test, and 4 of 8 (50%) low-grade SILs, 21 of 24 (88%) high-grade SILs, and 16 of 17 (94%) cervical cancers were found to have cytological abnormalities. There were discordances in some cases between findings of smear abnormality and telomerase positivity. In particular, we found five cases of SILs without smear abnormality but with telomerase activity, suggesting that some lesions with false negative cytology can be detected by telomerase assay. These findings suggest that telomerase assay using cervical scrapings might be a useful screening method for cervical lesions especially when combined with a Pap smear test.

Biomarkers, Tumor↗
PubMed1997

Bombyxin, an insulin-related peptide of insects, reduces the major storage carbohydrates in the silkworm Bombyx mori.

The effects of an insect insulin-related peptide, bombyxin, on carbohydrate metabolism were investigated in the silkworm Bombyx mori. Bombyxin lowered the concentration of the major hemolymph sugar, trehalose, in a dose-dependent manner when injected into neck-ligated larvae. Bombyxin also caused elevated trehalase activity in the midgut and muscle, suggesting that bombyxin induces hypotrehalosemia by promoting the hydrolysis of hemolymph trehalose to glucose and thereby facilitating its transport into tissues. In addition, bombyxin reduced the glycogen content in the fat body and concurrently raised the percentage of active glycogen phosphorylase in this tissue. Because hemolymph trehalose is also a major storage form of carbohydrate in insects, our results indicate that bombyxin reduces the amount of both principal storage carbohydrates in B. mori larvae. It is therefore suggested that although bombyxin is involved in the control of carbohydrate metabolism like insulin, the physiological role of bombyxin in insects is different from that of insulin in mammals.

Animals↗
PubMed1997

Omentopexy for anastomotic dehiscence after tracheal sleeve pneumonectomy.

A 54-year-old male patient developed anastomotic dehiscence following tracheal sleeve pneumonectomy for squamous-cell carcinoma of the right lung. Among various possible methods of treatment, omentopexy was adopted and proved very effective in the treatment of such a fatal complication.

Anastomosis, Surgical↗
PubMed1997

Human papillomavirus infection and risk determinants for squamous intraepithelial lesion and cervical cancer in Japan.

A case control design was used to investigate human papillomavirus (HPV) prevalence and risk factors associated with development of cervical squamous intraepithelial lesion (SIL) and cervical cancer (CC) in Japan. One hundred and twenty-three women with histologically confirmed SIL or CC were compared to a control group of 778 cytologically normal women. With the use of a polymerase chain reaction (PCR)-based method for detection of low-risk (types 6 and 11) and high-risk (types 16, 18, 31, 33, 35, 52 and 58) HPVs, a high prevalence of HPV infection was observed in smokers among the controls. Logistic regression analysis demonstrated that high-risk HPV infection was the most significant risk determinant for LSIL (OR=9.4, 95% CI=4.5-19), HSIL (OR=77, 95% CI=28-217) and CC (OR=97, 95% CI=35-269). It also showed that unmarried women, women married for 5 to 19 years and smokers represented high risk groups for SIL, while smokers and women with a history of many pregnancies/parities had increased risk for CC. Smoking was the only HPV infection-independent factor for CC, suggesting that smoking may have a carcinogenic effect on the cervix. Since neither history of other cancer nor family cancer history was associated with SIL or CC, genetic factors appear to play little role in cervical carcinogenesis. The risk for cervical neoplasia due to HPV infection increased after marriage in Japan, suggesting a role for husbands as carriers of HPV transmission. Protection from high-risk HPV infection may be of greatest importance for prevention of cervical cancer.

Adolescent↗
PubMed1997

Radiofrequency catheter ablation for AV nodal reentrant tachycardia associated with persistent left superior vena cava.

Slow AV nodal pathway ablation using RF is highly effective for patients with refractory AV nodal reentrant tachycardia (AVNRT). We report three catheter ablation cases using RF current in patients associated with persistent left superior vena cava (PLSVC). Three patients with drug refractory AVNRT of common variety were involved in this study. An electrode catheter introduced through the left subclavian vein inserted directly into the coronary sinus, a typical anatomical finding of PLSVC. The ablation procedure was initially performed at the posteroinferior region of Koch's triangle. A slow pathway potential could not be found from that area; nonsustained junctional tachycardia (NSJT) did not occur during the delivery of RF current; there was failure to eliminate slow AV nodal pathway conduction. The catheter then was moved into the bed of the proximal portion of the markedly enlarged coronary sinus. A slow AV nodal pathway potential was recorded through the ablation catheter, and the delivery of RF current caused NSJT in two patients. Complete elimination of slow AV nodal pathway conduction was accomplished in these two patients by this method. No adverse effects were provoked by this procedure. Catheter ablation of the slow AV nodal pathway guided by a slow pathway potential and the appearance of NSJT was feasible and safe in the area of the coronary sinus ostium in patients associated with PLSVC.

Adult↗
PubMed1997

Detection of vancomycin-resistant enterococci in fecal samples by PCR.

Surveillance cultures for vancomycin-resistant enterococci (VRE) are time-consuming and expensive for the laboratory to perform. Therefore, we investigated the use of PCR as an alternative method of detecting and identifying VRE directly in fecal samples. PCR primers directed to vanA, vanB, vanC1, vanC2, and enterococcal ligase genes were used to detect and identify VRE in fecal material obtained by rectal or perirectal swabbing. Although PCR-inhibitory substances were present in DNA prepared directly from the swabs, the inhibitory substances could be reduced by processing the nucleic acid with two commercially available DNA preparation columns. Fecal material from 333 swabs was cultured on several selective agar media before and after broth enrichment. DNA was extracted from the fecal material and was analyzed by PCR. By using all four primer sets, only 59 (67.8%) of the samples were positive for vanA. However, after retesting the negative samples with only the vanA primer set, 77 (88.5%) of 87 specimens that were culture positive for Enterococcus faecium containing vanA were positive by PCR. One specimen was PCR positive for the vanA gene but culture negative for enterococci. The specificity of the vanA assay was 99.6%. PCR analysis of enrichment broth samples with all four primers sets after 15 to 18 h of incubation detected 74 (85.1%) of the 87 culture-positive specimens. The specificity of the vanA assay after the enrichment step was 100%. No vanB-containing enterococci were recovered by culture. Since 16 samples can be tested by PCR in 4 h (including electrophoresis), identification of VRE is possible within 8 h of specimen submission at a cost of approximately $10.12/assay. Thus, PCR may be a cost-effective alternative to culture for surveillance of VRE in some hospitals.

Anti-Bacterial Agents↗
PubMed1997

[A 26-week oral repeated dose toxicity study of (+/-)-4-diethylamino-1,1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride monohydrate (NS-21), a novel drug for urinary frequency and incontinence, in rats followed by a 9-week recovery test].

A 26-week oral repeated dose toxicity study of (+/-)-4-diethylamino-1, 1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride monohydrate (NS-21), a new drug for the treatment of urinary frequency and incontinence, was conducted in Sprague-Dawley rats. Male and female rats were given the drug orally for 26 weeks at doses of 0 (control), 5, 50 and 500 mg/kg. After discontinuation of the treatment, a 9-week recovery test was also conducted. Two cases of death occurred in the 500 mg/kg group. Mydriasis, salivation and lacrimation were seen in the 50 and 500 mg/kg groups. Alopecia, a suppression of body weight gain and an increase in water consumption were seen in the 500 mg/kg group. Food consumption measurement showed no abnormalities attributable to the treatment. Ophthalmologic examination confirmed mydriasis in the 50 and 500 mg/kg groups. Urinalysis showed an increase in urine volume in the 50 and 500 mg/kg groups, and an increase in urinary protein and decreases in Na+, K+ and Cl- excretions in the 500 mg/kg group. Hematological examination showed decreases in hemoglobin, hematocrit, MCV, MCH, MCHC and lymphocytes in the 500 mg/kg group. Blood chemical examination showed increases in total cholesterol, phospholipid and total protein and decreases in glucose, triglyceride, free T3 and T4 in the 500 mg/kg group. Measurements of liver drug-metabolizing enzymes showed an increase in T4UDP-GT activity in the 50 and 500 mg/kg groups, and an increase in cytochrome P-450 in the 500 mg/kg group. Pathological examination disclosed hepatocellular hypertrophy caused by hyperplasia of smooth-ER in the 50 and 500 mg/kg groups, and a decrease in number of glycogen granules in the 500 mg/kg group. Stimulated thyroid follicles were seen in the 50 and 500 mg/kg groups. Increases in incidence and severity of chronic progressive nephropathy were also observed in the 500 mg/kg group. In this dose group, adrenocortical hypertrophy was also observed. The recovery test showed that the above-mentioned changes were satisfactorily reversible. The serum concentrations of NS-21 and its active metabolite, RCC-36, in the treated groups were increased in a dose-dependent manner. No treatment-related effects were seen in the 5 mg/kg group. These results show that the NOAEL (no observed adverse effect level) of NS-21 is 5 mg/kg for 26-week oral toxicity in rats.

Administration, Oral↗
PubMed1996

Inhibition of endothelial cell differentiation on a glycosylated reconstituted basement membrane complex.

The vascular basement membrane is involved in the regulation of endothelial cell differentiation. The accumulation of advanced glycosylation endproducts (AGEs) has been demonstrated on these basement membranes in patients with diabetes. We examined the effect of AGEs on endothelial cell behavior on reconstituted basement membrane, Matrigel. Human umbilical vein-derived endothelial cells (HUVECs) stopped proliferating and differentiated into capillary-like tube-shaped structures on Matrigel. Laminin antibody partially blocked this process. HUVECs cultured on glycosylated Matrigel, however, proliferated and formed a monolayer without tube formation. The inclusion of aminoguanidine, an inhibitor of AGE formation, during the glycosylation of Matrigel restored HUVEC differentiation. Although the laminin adsorbed onto the plastic culture wells promoted HUVEC attachment and spreading, glycosylated laminin reduced HUVEC attachment by 50% and abolished cellular spreading. These effects were restored by aminoguanidine. HUVEC attachment to glycosylated laminin was further reduced by AGE-modified albumin, poly I, acetylated low-density lipoprotein, or maleylated albumin, ligands for a scavenger receptor. Coating the culture dishes with the laminin peptides RGD, YIGSR, and SIKVAV supported the attachment of HUVECs that was unaffected by glycosylation. Results suggest that AGE accumulation on the basement membranes inhibits endothelial cell differentiation by impairing the normal interactions of endothelial cell receptors with their specific matrix ligands. This process may be involved in diabetic angiopathy.

Albumins↗
PubMed1996

Electrophysiologic effects of ischemic preconditioning on QT dispersion during coronary angioplasty.

OBJECTIVES: The aim of this study was to examine the effect of ischemic preconditioning on the manner of ventricular repolarization by assessing the change in QT dispersion during coronary angioplasty. BACKGROUND: QT interval dispersion reflects regional variations in ventricular repolarization and cardiac electrical instability. Previous studies have suggested that increased QT dispersion is associated with an increased incidence of malignant ventricular arrhythmias, whereas brief episodes of myocardial ischemia can render the heart more resistant to subsequent ischemic episodes, a phenomenon called ischemic preconditioning. METHODS: To assess the effects of ischemic preconditioning on myocardial repolarization by examining the change in QT dispersion during coronary angioplasty, we studied 47 consecutive patients (39 men and 8 women; mean age 57 +/- 16 years). QT dispersion was measured after each balloon inflation during coronary angioplasty. Statistical analysis was performed by using repeated measurement of analysis of variance. RESULTS: There were significant differences in QT dispersion as the number of balloon inflations increased (mean +/- SD 52 +/- 14, 42 +/- 11, 36 +/- 9, 31 +/- 10 and 29 +/- 11 ms, respectively [p < 0.01], for the first, second, third, fourth and fifth balloon inflations). The magnitude of decrease in QT dispersion was significant in the first and second balloon inflations, then became insignificant with later inflations. CONCLUSIONS: These data indicate that the gradual decrease in QT dispersion provoked by coronary artery occlusion and reperfusion during coronary angioplasty may be associated with electrophysiologic effects of ischemic preconditioning on myocardium in the human heart.

Angioplasty, Balloon, Coronary↗
PubMed1996

Ventricular tachycardia with narrow QRS duration, a right bundle branch block pattern, and right axis deviation abolished by catheter manipulation.

A 25-year-old women underwent electrophysiologic evaluation for sustained normal QRS complex tachycardia with a pattern of right bundle branch block and right axis deviation. Ventricular tachycardia was diagnosed by demonstrating fusion beats, atrioventricular dissociation, and bundle of His potential activation, which began before the onset of each QRS complex. A single ventricular extrastimulus was capable of easily provoking the tachycardia. There was an inverse relationship between the coupling interval of the first extrastimulus and the interval of the first tachycardia beat, suggesting reentry as the mechanism. The tachycardia was unexpectedly abolished during catheter manipulation in the left ventricle and has never recurred during 1 year of follow-up evaluation. The tachycardia was thought to be an unusual form of interfascicular tachycardia or microreentrant fascicular tachycardia.

Adult↗
PubMed1996

Radiofrequency ablation for WPW syndrome with monitoring the local electrogram at the ablation site.

Catheter ablation for septal accessory pathways is occasionally associated with complications, such as atrioventricular block, since the septal region is a complex anatomical structure containing the atrioventricular conduction system. Therefore, we designed a signal separator composed of an inductance-capacitance network with which the local electrogram at the ablation site could be continuously monitored during the delivery of radiofrequency (RF) energy. We tested the safety and efficacy of RF catheter ablation using a signal separator in 17 patients with septal accessory pathways (10 anteroseptal and 7 midseptal cases). RF energy (520 KHz) was applied at an output of 20-40 W for 30-120 sec. to the atrioventricular annulus where the shortest atrioventricular interval or accessory pathway potential was recorded on the electrogram using a large tip ablation electrode. In ablation for the anteroseptal or midseptal accessory pathways, the atrial to ventricular amplitude ratio on the local electrogram was maintained at 1 or less during the delivery of RF energy. In all 17 cases, the interruption of accessory pathways was successful without atrioventricular block. In one patient, accessory pathway conduction recurred which could be treated by the second session. There were no late complications during the 4 to 46 month follow-up period. In conclusion, RF catheter ablation using a signal separator is a safe and reliable method for treating patients with septal accessory pathways.

Adolescent↗