QTc-Prolongation in Posterior Circulation Stroke

Background and Purpose

To evaluate the relationship between infarct location and QTc-prolongation in patients with posterior circulation strokes.

Methods

Admission electrocardiograms (ECG) of 131 patients among a prospective sample of 407 consecutive adult patients in the New England Medical Center Posterior Circulation Registry were retrospectively analyzed. The QT interval (ms) was measured and corrected using Bazett’s formula (QTc_Bazett) as well as linear regression functions (QTc_Linear). QTc_Bazett > 440 ms and QTc_Linear ≥ 450 ms for men (≥460 ms for women) were considered prolonged. Multivariable linear and logistic regression analyses were used to identify independent predictors of the QTc.

Results

Overall, 34 % of patients had a prolonged QTc_Bazett and 7 % had a prolonged QTc_Linear noted on the admission ECG. There was a significant association between temporal lobe infarction and QTc_Bazett and QTc_Linear (p < 0.001 for both) in multivariable linear regression analyses adjusting for demographics, ECG parameters, and preadmission medication use. In multivariable logistic regression analysis, temporal lobe infarction emerged as an independent predictor of prolonged QTc_Bazett (p = 0.009) and QTc_Linear (p = 0.008), respectively. Sensitivity analyses excluding patients with transient ischemic attack yielded similar results. Exploratory analyses indicated that patients with temporal lobe infarction had worse functional 30-day outcomes in multivariable logistic regression (p = 0.022). However, there was no significant association between QTc and 30-day functional outcome.

Conclusions

QTc-prolongation is common after posterior circulation stroke and associated with temporal lobe infarction. Prospective studies are needed to confirm these preliminary findings and to examine potential long-term consequences.     

Arg-Phe-amide-related peptides influence gonadotropin-releasing hormone neurons

The hypothalamic Arg-Phe-amide-related peptides, gonadotropin-inhibitory hormone and orthologous mammalian peptides of Arg-Phe-amide, may be important regulators of the hypothalamus-pituitary-gonadal reproductive axis. These peptides may modulate the effects of kisspeptins because they are presently recognized as the most potent activators of the hypothalamus-pituitary-gonadal axis. However, their effects on gonadotropin-releasing hormone neurons have not been investigated. In the current study, the GT1-7 cell line-expressing gonadotropin-releasing hormone was used as a model to explore the effects of Arg-Phe- amide-related peptides on kisspeptin activation. Intracellular calcium concentration was quantified using the calcium-sensitive dye, fura-2 acetoxymethyl ester. Gonadotropin-releasing hormone released into the medium was detected via enzyme-linked immunosorbent assay. Results showed that 100 nmol/L kisspeptin-10 significantly increased gonadotropin-releasing hormone levels (at 120 minutes of exposure) and intracellular calcium concentrations. Co-treatment of kisspeptin with 1 μmol/L gonadotropin-inhibitory hormone or 1 μmol/L Arg-Phe-amide-related peptide-1 significantly attenuated levels of kisspeptin-induced gonadotropin-releasing hormone but did not affect kisspeptin-induced elevations of intracellular calcium concentration. Overall, the results suggest that gonadotropin-inhibitory hormone and Arg-Phe-amide-related peptide-1 may have inhibitory effects on kisspeptin-activated gonadotropin-releasing hormone neurons independent of the calcium signaling pathway.     

Assessment of the left atrial volume index and plasma NT-proANP level in patients with acute ST-elevation myocardial infarction

OBJECTIVES:

Acute ST-elevation myocardial infarction is associated with ventricular dysfunction due to ischemia-induced progressive myocardial damage. The decrease in ventricular compliance causes left atrial dilatation and stretching of the atrial myocardium, which are the main stimuli for the secretion of atrial natriuretic peptide. The aim of this study was to evaluate left atrial dimensions and atrial natriuretic peptide levels in patients early after their first acute ST-elevation myocardial infarction and assess the probable interaction between coronary lesions and these measurements.

METHODS:

A total of 110 patients with acute myocardial infarction and 50 controls were studied. Plasma atrial natriuretic peptide was measured at admission. Left ventricular function, diameter, and volume index were evaluated using transthoracic echocardiography. Gensini and vessel scores of the patients who underwent coronary angiography were calculated.

RESULTS:

Plasma atrial natriuretic peptide in the patients with myocardial infarction was increased compared with that in controls (3.90±3.75 vs. 1.35±0.72 nmol/L, p<0.001). Although the left atrial diameter was comparable in patients and controls, the left atrial volume index was increased in patients with acute myocardial infarction (26.5±7.1 vs. 21.3±4.9 mL/m², p<0.01). Multivariate regression analysis showed a strong independent correlation between the left atrial volume index and the plasma atrial natriuretic peptide level (β = 0.23, p = 0.03).

CONCLUSIONS:

The left atrial volume index and plasma atrial natriuretic peptide level were correlated in patients with acute myocardial infarction.     

Effect of Agitation of EDTA with 808-Nanometer Diode Laser on Removal of Smear Layer

Introduction

Near-infrared diode lasers can be used for several applications, which range from disinfection to smear layer removal in endodontics. This study evaluated the efficacy of agitation of 15% EDTA with an 808-nm diode laser on removal of the smear layer.

Methods

Sixty extracted human maxillary central incisor teeth were instrumented up to ProTaper F4 (Dentsply Maillefer, Ballagues, Switzerland) and then randomly divided into 6 groups (n = 10 for each group) according to the different final irrigating protocols as follows: 5% sodium hypochlorite for 120 seconds performed with the NaviTip (Dentsply Maillefer, Ballaigues, Switzerland) (control group); 15% EDTA for 120 seconds performed with the NaviTip; and agitation of 15% EDTA with an 808-nm diode laser for 10, 20, 30, and 40 seconds. Specimens were observed under a scanning electron microscope, and open dentinal tubules were counted using Adobe Photoshop software (Adobe Systems, San Jose, CA). The data were analyzed with 1-way analysis of variance and Tukey post hoc tests (P = .05).

Results

The number of open dentinal tubules was higher in the middle thirds than in the apical thirds. The differences between the apical and middle thirds were statistically significant (P < .05). Statistically significant differences were also found between the control group and the other groups in both the middle and apical thirds of the root canals (P < .05).

Conclusions

The results indicated that agitation of 15% EDTA with an 808-nm diode laser for 20 seconds was effective in removing the smear layer in the apical thirds of root canals.     

Variation in PTX3 Is Associated with Primary Graft Dysfunction after Lung Transplantation

Rationale: Elevated long pentraxin-3 (PTX3) levels are associated with the development of primary graft dysfunction (PGD) after lung transplantation. Abnormalities in innate immunity, mediated by PTX3 release, may play a role in PGD pathogenesis. Objectives: Our goal was to test whether variants in the gene encoding PTX3 are risk factors for PGD. Methods: We performed a candidate gene association study in recipients from the multicenter, prospective Lung Transplant Outcomes Group cohort enrolled between July 2002 and July 2009. The primary outcome was International Society for Heart and Lung Transplantation grade 3 PGD within 72 hours of transplantation. Targeted genotyping of 10 haplotype-tagging PTX3 single-nucleotide polymorphisms (SNPs) was performed in lung transplant recipients. The association between PGD and each SNP was evaluated by logistic regression, adjusting for pretransplantation lung disease, cardiopulmonary bypass use, and population stratification. The association between SNPs and plasma PTX3 levels was tested across genotypes in a subset of recipients with idiopathic pulmonary fibrosis. Measurements and Main Results: Six hundred fifty-four lung transplant recipients were included. The incidence of PGD was 29%. Two linked 5' region variants, rs2120243 and rs2305619, were associated with PGD (odds ratio, 1.5; 95% confidence interval, 1.1 to 1.9; P = 0.006 and odds ratio, 1.4; 95% confidence interval, 1.1 to 1.9; P = 0.007, respectively). The minor allele of rs2305619 was significantly associated with higher plasma PTX3 levels measured pretransplantation (P = 0.014) and at 24 hours (P = 0.047) after transplantation in patients with idiopathic pulmonary fibrosis. Conclusions: Genetic variants of PTX3 are associated with PGD after lung transplantation, and are associated with increased PTX3 plasma levels.     

Semen quality and reproductive endocrinal function related to blood lead levels in infertile painters

Lead causes male reproductive impairment among painters, but information is still limited. Therefore, the effect of lead on semen quality and reproductive endocrinal function in those patients was investigated. A case series of 27 infertile painters were subjected to semen analysis, measuring of blood lead level (PbB) and serum levels of endocrinal parameters including follicle‐stimulating hormone (FSH), luteinising hormone (LH), testosterone (T) and prolactin (PRL). Significantly lower sperm count and motility were found in those with duration of exposure (≥15 years), but no significant difference was found for PbB and serum levels of FSH, LH, PRL and T. A significant negative correlation between PbB and spermatic count and motility was observed, while there was no significant correlation between PbB and all endocrinal parameters. Patients with PbB ≥ 20 μg dl^?1 showed a significant decrease in sperm motility and increase in testosterone alone among all measured hormones. But the observed decrease in sperm count did not reach a significant level. It is concluded that infertile painters are at risk of lead‐related influence on semen quality, especially sperm motility and increased testosterone level without significant affection of other reproductive endocrinal parameters.