The effect of varenicline on heart rate variability in healthy smokers and nonsmokers

Varenicline is an α4β2 nicotinic acetylcholine receptor partial agonist. In this study, we assessed the effects of varenicline on heart rate variability (HRV). Thirty subjects were included in the randomized, double-blind, placebo-controlled, crossover study. Varenicline or placebo was administered in two different testing sessions. Time domain parameters and power spectral analysis of HRV were assessed in the supine position and during handgrip exercise before and after the participants were given placebo or varenicline. Fifteen healthy non-smokers (NS) and fifteen healthy smokers (S) were included in the study. There were no statistically significant differences among any of the time domain parameters obtained before and after placebo administration or between the S and NS groups with respect to varenicline administration. In frequency domain analyses, normalized HF (high-frequency) powers were significantly higher in the S group than in the NS group (before placebo, NS:6.57±3.58 vs. S:13.85±7.50, p=0.002, after placebo, NS:6.33±3.89 vs. S:10.82±4.88, p=0.007). After varenicline administration, the normalized HF power was significantly higher (NS:6.65±4.34 vs. S:11.06±4.52, p=0.01), and the ratio of LF (low-frequency) to HF was significantly lower (NS:8.44±5.89 vs. S:4.97±4.60, p=0.02) in the S group than in the NS group. Administration of a single dose of varenicline significantly increased the LF/HF ratio (5.83±2.69 vs. 8.44±5.89) in the NS group, but in the S group, there were no significant differences related to any of the time or frequency domain parameters. We concluded that a single dose of varenicline does not affect HRV in healthy smokers but that it may alter HRV when administered at a therapeutic dose to healthy non-smokers during mild sympathetic stimulation.     

Prevalence of left main coronary artery disease among patients referred to multislice computed tomography coronary examinations

We have evaluated the prevalence of left main coronary artery disease (LMCAD) among patients referred to multislice computed tomography (MSCT) coronary angiography examinations. The study Group comprised of 1,000 consecutive patients (750 male and 250 female; mean age 53±12 years) who underwent successful 64-slice MSCT examinations. Left main coronary artery (LMCA) was classified into three Groups: normal LMCA; nonsignificant LMCAD with coronary plaques resulting in obstructions ≤50%; and significant LMCAD corresponding to obstructions >50%. We have found that 24 patients (2.4%) had significant LMCAD. Additional 200 patients (20%) had nonsignificant LMCAD. Univariate analysis revealed that LMCAD was associated with age, male gender, diabetes, hypertension, hyperlipidemia, typical symptoms, history of previous myocardial infarction and previous percutaneous coronary intervention. Only age and male gender were found as independent predictors for LMCAD in multivariate analysis (P < 0.001 and P = 0.001, respectively,). Angiographic follow-up was avaliable for the 24 patients with significant LMCAD, and conventional coronary angiography confirmed the presence of significant LMCAD in all of these patients. Significant LMCAD was found in 2.4% of the 1,000 patients referred to 64-slice MSCT examinations. Age and male gender were the independent predictors for LMCAD.     

MBL,P2X7, and SLC11A1 gene polymorphisms in patients with oropharyngeal tularemia

Conclusion: A significant association was found of oropharyngeal tularemia with SLC11A1 allele polymorphism (INT4?G/C) and MBL2 C?+?4T (P/Q). These results indicate C allele and Q allele might be a risk factor for the development of oropharyngeal tularemia.

Aim: This study aimed to investigate the relationship of SLC11A1, MBL, and P2X₇ gene polymorphism with oropharyngeal tularemia.

Methods: The study included totally 120 patients who were diagnosed with oropharyngeal tularemia. Frequencies of polymorphisms in the following genes were analyzed both in the patient and control groups in the study: SLC11A1 (5’(GT)_n Allele 2/3, Int4?G/C, 3’ UTR, D543N G/A), MBL (MBL2 C?+?4T (P/Q), and P2X₇ (?762 C/T and 1513 A/C).

Results: Among all polymorphisms that were investigated in this study, SLC11A1 gene showed a significance in the distriburtion of polymorphism allelle frequency at the INT4 region. Frequency of C allele was 54 (28%) in patients with oropharyngeal tularemia, and 31 (13%) in the control group (p?=?0.006 and OR = 1.96 (1.21–3.20)). An association was detected between MBL2 C?+?4T (P/Q) gene polymorphism and oropharyngeal tularemia (p?7 (?762 C/T and 1513 A/C) gene polymorphism and oropharyngeal tularemia in this study (p?>?0.05).     

Anti-apoptotic effect of succinyl gelatine in a liver ischaemia–reperfusion injury model (Bcl-2, Bax, Caspase 3)?

Apoptosis of tissues may contribute to ischaemia–reperfusion injury. The aim of the present study was to determine whether administration of a colloid solution would prevent apoptosis after liver ischaemia–reperfusion. New Zealand rabbits, weighing 1.5–2 kg, were randomized to receive either 4% SG (20 ml kg ⁻¹h⁻¹ ) by 30 min of intravenous (i.v.) infusion (Group I, n= 7) or equivalent volumes of 0.9% sodium chloride (Group II, n= 6) i.v. before a 45 min interruption of the portal vein blood flow and then 45 min of reperfusion. The animals were killed following the reperfusion period. Their livers were processed for histopathological examination and paraffin sections of these tissues were examined. The expression of Bcl-2, Bax and caspase 3 were analysed by immunohistochemistry. ANOVA and the Wilcoxon W -test were used for statistical analysis, and mean values were expressed ±sd. Histologically, the foci of ischaemic necrosis were observed in liver specimens of the periportal area in one of the animals in Group I and in two in Group II. Immunhistochemical analysis demonstrated an increase in Bcl-2 protein levels in Group I compared to Group II ( P< 0.05). Bax expression was lower in Group I than in Group II. Immunoreactivity for caspase 3 did not differ significantly between the two groups (47.0 ± 35.93 in Group I, 32.83 ± 23.63 in Group II). Our results indicate that gelofusine did not protect the liver tissue against ischaemia–reperfusion-induced apoptosis.     

Prediction of difficult laryngoscopy using spirometry: a pilot study

Prediction of difficult laryngoscopy is still the uncovered secret of anesthetic practice. This pilot study is aimed to assess the efficacy of spirometry measurements in predicting difficult laryngoscopy compared with conventional airway assessment techniques. We enrolled 202 adults, ages 18–40 years, with an American Society of Anaesthesiologists score of I or II, scheduled for elective surgery and undergoing general anesthesia. Spirometry was used for lung capacity measurements before the operation. The Mallampati classification, neck circumference, sternomental distance, thyromental distance, maximum mouth-opening measurement, and upper lip bite test of the subjects were measured. During intubation, the Cormack–Lehane grade was recorded. Spearman’s correlation analysis was used to define the linearity between spirometry outputs and airway measurements. Receiver operating curves were drawn to discriminate the predictive features of the significant values. The thyromental distance showed a higher correlation with forced inspiratory vital capacity (ρ = 0.420, P < 0.001). In a multivariate linear regression model, all spirometry measurements revealed that forced inspiratory vital capacity (β = ?2.050, P = 0.022) was the significant predictor for difficult laryngoscopy. The area under the curve for forced inspiratory vital capacity with a cut-off value of 3.1950 L while using thyromental distance as difficult laryngoscopy indicator is 0.754 and forced inspiratory vital capacity showed a sensitivity of 0.718 and specificity of 0.714 with a positive likelihood ratio of 2.5104 and negative likelihood ratio of 0.3949. Forced inspiratory vital capacity showed a close association with the prediction of difficult laryngoscopy.