Possible role of sildenafil in inhibiting rat vas deferens contractions by influencing the purinergic system

AIM: To evaluate the effect of sildenafil, a selective inhibitor of cyclic guanosine monophosphate (cGMP)-selective type 5 phosphodiesterase, on isolated rat vas deferens and its connections with the purinergic system. METHODS: Epididymal and prostatic portions of isolated vas deferens were placed in organ baths containing Krebs' solution. Contractions were induced by noradrenaline (NA), adenosine triphosphate (ATP), alpha,beta-methylene ATP and electrical field stimulation (EFS). The effect of sildenafil on the contractions was compared with suramin and Evans blue (EB). RESULTS: NA, ATP, alpha,beta-methylene ATP and EFS caused contractions in both portions of vas deferens. NA-induced contractions were unaffected by sildenafil and suramin but potentiated by EB. ATP-induced contractions were non-competitively inhibited in both portions by sildenafil and suramin but potentiated by EB. alpha,beta-methylene ATP-induced contractions were unaffected by sildenafil but were inhibited in both portions by suramin and EB. EFS-induced contractions were inhibited by sildenafil and suramin while potentiated by EB. CONCLUSION: Sildenafil inhibited the contractions in both portions of vas deferens, as did suramin. We have suggested that purinergic system has a role in this antagonism and it seems to be mediated by an ATP-dependent mechanism instead of a receptor interaction.     

HB-Ag in Sweat

Thirty patients were studied at the Hacettepe University Medical Center. Ten patients had hepatic cirrhosis, 20 patients had viral hepatitis. HB-Ag in the serum was positive in all patients by the counterimmunoelectrophoresis method. One and a half milliliters of sweat was collected from each patient, dried and dissolved in 0.2 ml. of buffer solution. HB-Ag was positive in all patients by radioimmunoassay method. This study indicates that direct contact is one of the most important factors in the epidemiology of the disease and this may even be more important in asymptomatic carriers.     

Do blood contamination and haemostatic agents affect microtensile bond strength of dual cured resin cement to dentin?

Objective:

The purpose of this study was to evaluate the effects of blood contamination and haemostatic agents such as Ankaferd Blood Stopper (ABS) and hydrogen peroxide (H₂O₂) on the microtensile bond strength between dual cured resin cement-dentin interface.

Material and Methods:

Twelve pressed lithium disilicate glass ceramics were luted to flat occlusal dentin surfaces with Panavia F under the following conditions: Control Group: no contamination, Group Blood: blood contamination, Group ABS: ABS contamination Group H₂O₂: H₂O₂ contamination. The specimens were sectioned to the beams and microtensile testing was carried out. Failure modes were classified under stereomicroscope. Two specimens were randomly selected from each group, and SEM analyses were performed.

Results:

There were significant differences in microtensile bond strengths (µTBS) between the control and blood-contaminated groups (p<0.05), whereas there were no significant differences found between the control and the other groups (p>0.05).

Conclusions:

Contamination by blood of dentin surface prior to bonding reduced the bond strength between resin cement and the dentin. Ankaferd Blood Stoper and H₂O₂ could be used safely as blood stopping agents during cementation of all-ceramics to dentin to prevent bond failure due to blood contamination.     

Is There a Relationship between Vitamin B12 and Stress Urinary Incontinence?

Objective: Pelvic floor, which includes collagen, elastin, and smooth muscle, is very important in preventing urinary incontinence (UI). Studies suggest that vitamin B12 is involved in collagen synthesis. In the present study we aimed to determine the association of vitamin B12 deficiency with stress UI in a sample of Turkish women. Methods: Forty‐two women with stress UI or mixed UI who met the inclusion criteria from a group of 541 women with stress UI or mixed UI, were included in the study. The study group was compared with a control group of 20 healthy women without UI who matched to the study group's demographic data and met the inclusion criteria. Demographic data as well as duration of symptoms and vitamin B12 levels were analyzed and compared. Results: The mean ages of the study and the control groups were 50.04 ± 4.6 and 49.02 ± 5.1 years, respectively. Vitamin B12 level was 300.95 ± 142.9 pg/mL in the study group, whereas in the control group it was 598.98 ± 120.3 pg/mL (P < 0.001). In the study group, 66.6% of the patients with stress UI had vitamin B12 levels less than 300 pg/mL. When the duration of symptoms and vitamin B12 levels were compared, women with vitamin B12 levels less than 200 pg/mL had symptoms for a longer duration (P < 0.01). Conclusion: One of the main etiologic factors for stress UI is a defect in pelvic floor support. Vitamin B12 is lower in women with stress UI. Analysis of vitamin B12 levels should also be considered in the evaluation of women with stress UI.     

Assessment of Heart Rate Turbulence in the Acute Phase of Myocardial Infarction for Long-Term Prognosis

SADE, E., et al .: Assessment of Heart Rate Turbulence in the Acute Phase of Myocardial Infarction for Long-Term Prognosis. This study is designed to assess the value of heart rate turbulence (HRT) in the acute phase of MI for prediction of long-term mortality risk. The study included 128 consecutive acute MI patients with 24-hour Holter recordings to evaluate HRT (turbulence onset and slope), SDNN, mean RR interval, and ventricular premature beat frequency. LVEF was evaluated by two-dimensional echocardiography. Data from 117 patients (mean age 58 ± 11 years ) were available for further analysis. Twelve patients died during follow-up (mean 312 ± 78 days ). Although SDNN < 70 ms was the most powerful predictor of mortality among all presumed risk factors (hazard ratio 20 [95% CI 2.6–158]; P = 0.004) in univariate Cox regression analysis, in multivariate analysis LVEF ≤ 0.40 and turbulence slope ≤2.5 ms/RR interval were the only independent predictors of mortality (hazard ratio 6.9 [95% CI 1.8–26]; P = 0.006, hazard ratio 7.3 [95% CI 1.4–37]; P = 0.016, respectively). Addition of HRT parameters for LVEF increased remarkably the positive predictive value (60%) without any decrease in the negative predictive value (92%). Blunted HRT reaction within the first 24 hours of acute MI is an independent predictor of long-term mortality. Furthermore, its predictive power is comparable and also additive to that of LVEF. (PACE 2003; 26[Pt. I]:544–550)