Conduction abnormalities in nonischemic dilated cardiomyopathy: basic mechanisms and arrhythmic consequences

Heart failure is associated with an increased risk of sudden death caused by ventricular tachyarrhythmias. The role of altered repolarization in the formation of arrhythmogenic substrates and triggers has been studied at multiple levels of integration, including molecular, cellular, tissue, and organ levels. Numerous studies have focused on conduction abnormalities in the context of ischemic heart disease and left ventricular dysfunction after myocardial infarction. However, ischemia alone, independent of left ventricular dysfunction, alters conduction by depressing membrane excitability and increasing tissue resistivity. In this review, we focus on the role of conduction abnormalities in the genesis of arrhythmias in nonischemic dilated cardiomyopathy and discuss their underlying cellular and molecular mechanisms, including changes in myocyte excitability, the extracellular matrix, and cell-to-cell coupling. We compare the nature of conduction slowing in ischemic and nonischemic heart failure and highlight the mechanistic differences between the two disease etiologies.     

What is adverse effect of wireless local area network,using 2.45 GHz,on the reproductive system?

Aim: To investigate the inflammatory effect and testicular damage on rats exposed to low level of electromagnetic fields (EMF) at 2.45?GHz microwave radiation.

Methods: Twenty two Wistar rats were divided into two groups. Group 1 was the control group and not exposed to EMF. Group 2 was exposed to low level EMF (average E-field 3.68?±?0.36 V/m, whole body average SAR, 0.0233 W/kg, in 10?g tissue) at 2.45?GHz for 1?hour/day for 30 consecutive days. At the end of the study, interleukin-6 (IL-6), interleukin-10 (IL-10), interleukin-32 (IL-32), C-reactive protein (CRP) were measured in rat serum and IL-6, IL-10, IL-32 were measured in rat testis tissue. Furthermore, testicular tissues were evaluated histopathologically in terms of spermatogenesis and coagulation necrosis.

Results: Serum IL-6 and CRP levels were found to be significantly different in the study group compared to the control group (p?<?.05), but no significant difference was found in serum IL-10, IL-32 levels and testis tissue IL-6, IL-10, IL-32 levels compared to the control group (p?>?.05). On the other hand, histopathological evaluation of testicular tissue revealed a significant difference in necrosis and spermatogenesis when compared with the control group (p?<?.05).

Conclusions: It may be concluded that low level EMF at 2.45?GHz increases inflammation and testicular damage and negative impact on male reproductive system function.     

Serum lactate levels and perfusion index: are these prognostic factors on mortality and morbidity in very low-birth weight infants?

Aim: Early hemodynamic assessment of global parameters in critically ill newborns fails and requires mostly invasive measurements in neonatal intensive care unit. Clinical signs are frequently used for assessment of peripheral perfusion. Perfusion index (PI) is a new noninvasive numerical value of peripheral perfusion. Serum lactate levels and PI are the indicators that are important in determining prognosis of preterm infants. In this study, we aimed to investigate the relationship of serum lactate levels and PI with mortality and morbidity in very low-birth weight infants (VLBW).

Study design: This study was conducted between July 2014 and July 2015 in a Level III NICU. The study enrolled preterm infants with a gestational age?≤?32 weeks, birth weight?≤?1500?g. Serum lactate levels from blood gases and PI, SpO2 measurements were recorded at 1st, 12th and 24th hours by using a new generation pulse-oximeter. Morbidities and mortalities were documented.

Results: A total of 60 VLBW infants were enrolled the study. Mean birth weight and gestational age were 991?±?288?g and 27.5?±?2.5 w, respectively. Retinopathy of prematurity (ROP) was significantly higher in the patients with high lactate levels (>4?mg/dl) at 1st hour and low-PI levels (<0.5) at 12th hour of life (p?=?0.042, p?=?0.015), respectively. Bronchopulmonary displasia (BPD) was significantly higher in the patients with low PI (Conclusion: High lactate levels (>?4?mg/dl) and low PI (相似文献   

Impact of oral probiotics on neurodevelopmental outcomes in preterm infants

Objective: The aim of the study was to evaluate the neurodevelopment outcomes of very low birth weight (VLBW) preterm infants supplemented with oral probiotics for the prevention of necrotizing enterocolitis (NEC).

Methods: A prospective follow-up study was performed in a cohort of VLBW preterm infants enrolled in a single center randomized controlled clinical trial to evaluate the efficacy of oral probiotics for the prevention of NEC. Cognitive and neuromotor developments were assessed by using the Bayley scales of infant development II. Sensory and neurological performance was evaluated by standard techniques. The primary outcome was neurodevelopmental impairment at 18–24 months’ corrected age.

Results: A total of 400 infants completed the trial protocol. Of the 370 infants eligible for follow-up, 249 infants (124 in the probiotics group and 125 in the control group) were evaluated. There was no significant difference in any of the neurodevelopmental and sensory outcomes between the two groups.

Conclusion: Oral probiotic given to VLBW infants to reduce the incidense and severity of NEC started with the first feed did not affect neuromotor, neurosensory and cognitive outcomes at 18–24 months’ corrected age.     

Protective effect of cromakalim and diazoxide, and proulcerogenic effect of glibenclamide on indomethacin-induced gastric injury.

We investigated the influences of the K+ channel opening drugs cromakalim and diazoxide and their blocker, glibenclamide, in indomethacin-induced gastric injury in rats. Cromakalim (0.1 and 0.3 mg/kg) and diazoxide (10 and 30 mg/kg) produced dose-dependent gastroprotection at doses that were also effective on the cardiovascular system. Glibenclamide reversed their gastroprotective effects and aggravated indomethacin-induced gastric damage by its own. Cromakalim (10(-9)-10(-5) M) and diazoxide (10(-9)-10(-4) M) relaxed noradrenaline pre-contracted gastric arteries (94.59+/-1.58% and 93.86+/-2.99%, respectively). Their relaxant effects were inhibited by glibenclamide (10(-5) M) but not by indomethacin (10(-5) M) and LG-nitro-L-arginine (10(-4) M). Cromakalim (0.1 and 0.3 mg/kg) did not change gastric mucosal blood flow but increased the gastric mucosal vascular conductance in anaesthetized rats as measured by the hydrogen gas clearance technique. Indomethacin increased myeloperoxidase activity in the gastric mucosa, an effect which was reversed by cromakalim and diazoxide. Glibenclamide abolished their effects on myeloperoxidase activity and, alone, increased this parameter. Additionally, indomethacin caused infiltration of neutrophils which was reduced by cromakalim and diazoxide in a glibenclamide sensitive manner. The effects of cromakalim and diazoxide on mucosal myeloperoxidase activity, neutrophil infiltration and gastric injury correlated with each other. The effects of diazoxide (30 mg/kg) and glibenclamide (10 mg/kg) on blood glucose level were not correlated with their effects on gastric injury. Taken together, K+ channel opening drugs show misoprostol-like protective effects in indomethacin-induced gastric injury which seems to be related to modulation of neutrophil function.     

Familial Mediterranean fever and systemic amyloidosis in untreated Turkish patients

We compared the frequencies of seven MEFV mutations (M694V, M680I, V726A, M694I, K695R, R761H, E148Q) and the clinical findings in 20 Turkish FMF patients who had not developed amyloidosis by the age of 40 years in the absence of colchicine therapy, with those in 27 Turkish amyloidosis patients. No mutation frequency, including that of M694V, was different between the two groups. Family history of amyloidosis and parental consanguinity were noted to be higher in the amyloidosis group. The seven mutations do not appear to be sufficient to explain the development of amyloidosis in Turkish FMF patients. Other genetic factors may be important for this association.     

Postnatal assessment of growth,nutrition, and urinary tract infections of infants with antenatally detected hydronephrosis

The widespread utilization of prenatal ultrasonography and the detection of antenatal hydronephrosis (AH) have raised the importance of postnatal follow-up of these infants. In this study, we aimed to determine the importance of an early diagnosis for the treatment of urinary tract malformations (UTM) as well as the postnatal evaluation of growth and nutrition status and the frequency of urinary tract infection (UTI) in infants with AH. We evaluated 246 infants (183 boys, 63 girls) whose routine antenatal scans showed an anterior-posterior pelvic diameter (APPD) ≥5 mm. Of the 246 patients, 175 (71.1%) were found to be pathological and 71 were evaluated as normal after the follow-up period. The median follow-up periods of normal and abnormal cases were 45.7 and 43.4 months, respectively. All cases with or without UTM were evaluated in terms of UTI, scars on DMSA, growth [Height Z score (HZ), Weight Z score (WZ)] and nutrition [Weight height index (WHI)] status. The annual UTI frequency was higher in cases with UTM (1.32 ± 1.66 episode/year) than in cases without abnormality (0.27 ± 0.67 episode/year) (P < 0.001). The postnatal evaluation of growth and nutritional status in children with UTM (mean WHI, HZ, and WZ scores: 96.82 ± 10.21, 0.03 ± 0.54 and 0.04 ± 0.61, respectively) was found to be significantly worse than in cases without abnormality (102.25 ± 9.84, 0.14 ± 0.64 and 0.24 ± 0.76, respectively), (P < 0.05). In abnormal patients, the mean WHI, HZ, and WZ were significantly improved to 101.63 ± 9.75, 0.26 ± 1.07, and 0.28 ± 0.98, respectively, and HZ or WZ scores were found to be similar when compared to normals. In conclusion, postnatal early management of infants with AH seems to prevent frequent UTIs and nutritional disturbances enabling normal growth.     

The association of low-grade systemic inflammation with hypertensive retinopathy

High-sensitivity C-reactive protein (hs-CRP) is a marker of systemic low-grade inflammation. The pathophysiologic mechanism of hypertensive retiopathy (HR) is not fully established. Elevated blood pressure (BP) alone does not fully account for the extent of retinopathy, other pathogenic mechanisms may be involved, such as low-grade inflammation. Therefore, this study was designed to answer the following questions. (i) Do hs-CRP levels change in HR? (ii) Is there any relation between degree of HR and hs-CRP levels? This study included 84 hypertensive patients with HR. The hypertensive patients were divided into two groups according to the Keith-Wagener classification. Group 1 comprised 42 patients with grade I HR, and Group 2 comprised 42 patients with grade II HR. We selected 42 healthy subjects matched for age, sex, and body mass index (BMI) for control group. The level of hs-CRP in group 2 was significantly higher than in group 1 group (p = 0.018) and control group (p = 0.001), it was also higher in group 1 than in control group (p = 0.002). Also, hs-CRP showed positive correlations with degree of HR (r = 0.29, p = 0.017). Our study suggests that there is a relationship between HR and hs-CRP levels, which may be associated with systemic low- grade inflammation.     

Pulmonary artery aneurysms in Behçet’s disease

Behçet’s disease is the most common cause of pulmonary artery aneurysms. Pulmonary artery aneurysms are rare, but they are life-threatening because of their high tendency to rupture. However, there is also a chance that the aneurysms may completely resolve with immunosuppressive therapy. A 30-year-old man was admitted with chest pain, painful oral and genital ulcers, skin rash, weakness, and intermittent hemoptysis. He had a history of Behçet’s disease for 6 years. The chest radiography showed a round opacity superior part of hilus on right. The helical thoracic computed tomography (CT) angiography demonstrated pulmonary aneurysms associated with Behçet’s disease. The patient was successfully treated with colchicine, corticosteroids, and cyclophosphamide. A discussion about pulmonary artery aneurysms associated with Behçet’s disease is provided in this case.