Effect of different doses of hexavalent chromium on mandibular growth and tooth eruption in juvenile Wistar rats

Not only workers employed at industrial plants are exposed to intoxication with the element they manipulate, the population at large is also at risk of suffering health problems caused by contaminating wastes inadequately treated for their safe disposal. As a result certain toxic substances, such as hexavalent chromium,has reached the general population including children. The present study sought to evaluate the effect of intoxication with hexavalent chromium on body and mandibular growth and tooth eruption in suckling Wistar rats. Potassium dichromate was administered by gavage in a dose of 6.25 or 12.5 mg/kg body weight (b.w.) to one of the two groups of 4-day-old Wistar rats during 10 days. Our results showed that the effects of chromium are dose-dependent. Morphometric studies of body growth showed lower body weight in both experimental groups and shorter tail length in animals receiving 12.5 mg/kg b.w. dose of chromium, compared with controls. All parameters of mandibular growth were lower in the experimental group receiving 12.5 mg/kg b.w. of chromium. Differences in tooth eruption were observed at the level of the first molar in animals receiving 12.5 mg/kg and of the second molar in those receiving 6.25 mg/kg b.w. of chromium. Chromium was found to affect all the studied parameters.     

Heart-hand syndrome

Heart–hand syndromes show substantial clinical and genetic heterogeneity. The unusual case of a patient with a heart–hand syndrome consisting of preaxial polydactylia, postaxial syndactylia, parachute mitral valve, mild subaortic stenosis, and double outlet right ventricle is presented and discussed. The importance of distinguishing Holt–Oram syndrome from its phenocopies and other heart–hand syndromes is underlined.     

Unsafe Drug Use and Arrhythmic Events in Brugada Patients with ICD: Results of a Long-Term Follow-Up

Purpose

Brugada syndrome is a hereditary disease linked with an increased risk of sudden death that may require an implantable cardioverter-defibrillator (ICD) in order to halt the arrhythmic events. The aim of this study was to identify possible triggers for appropriate ICD therapies in patients with Brugada syndrome, focusing on their past and current therapeutic profiles.

Methods

Thirty patients with high-risk Brugada syndrome, with ICD implanted at the Coimbra Hospital and University Center, were enrolled. Patients were questioned about their Brugada syndrome history, previous cardiac events, comorbidities, present and past medications, and physical activity. Patients were followed up during 5.8?±?5.3 years. The ICD was interrogated, and arrhythmic events and device therapies were recorded. The cohort who received appropriate ICD therapies was compared with the remaining patients to determine the potential link between clinical variables and potentially fatal arrhythmic events.

Results

More than half of the patients (53.3%) took at least one non-recommended drug, and 16.7% received appropriate ICD therapies, with a long-term rate of 4.0%/year. There was a tendency for more appropriate ICD therapies in patients who took unsafe drugs (85.7 versus 45.5%, p?=?0.062), and the mean time between unsafe drug intake and appropriate ICD therapies was 3.8?±?7.5 days.

Conclusions

This study revealed that the medical community is still unaware of the pharmacological restrictions imposed by Brugada syndrome. Patients who took non-recommended drugs seem to have a higher risk of ventricular arrhythmic events.

     

Angiographic and intravascular ultrasound findings of the late catch-up phenomenon after intracoronary beta-radiation for the treatment of in-stent restenosis

We report one-year angiographic and intravascular ultrasound (IVUS) outcomes of in-stent restenosis (ISR) patients treated with intravascular brachytherapy (IVBT). The benefit of IVBT for treating ISR is well documented. However, few data exist on significant angiographic and intravascular ultrasonic in-stent lumen deterioration beyond the habitual 6-month analysis after the index radiation procedure or so-called late catch-up process in the treatment of ISR. Twenty-five consecutive patients with ISR were treated with IVBT using the Beta-Cath System (a 40 mm 90 Sr per 90 gamma source). Quantitative angiographic and IVUS analysis was performed in all of them at 6 and 12 months. IVBT was successful in all patients. Four patients (16%) developed recurrent angiographic binary restenosis at 6-month follow-up, all located within the adjacent reference segments, with 2 being associated with geographical miss. An additional 4 patients (16%) presented with recurrent ISR at 12-month follow-up, all within the stented segment. Significant in-stent lumen loss (0.16 +/- 0.42 mm to 0.34 +/- 0.46 mm; p = 0.008) and in-stent intimal hyperplasia growth (+11.2 +/- 0.48 mm3; p = 0.03) was observed between 6 and 12 months. Intracoronary beta-radiation for the treatment of ISR was associated with significant luminal deterioration (late catch-up) within the stents between 6 and 12 months due to an important late progression of in-stent intimal hyperplasia.     

Mechanical valve prosthesis is a valid option for aortic valve replacement in the elderly

BACKGROUND AND AIM OF THE STUDY: Thromboembolism and hemorrhage related to anticoagulation remain a major concern in elderly patients with mechanical valves. Clinical results following isolated aortic valve replacement (AVR) with tilting disk and bileaflet prostheses in patients aged over 70 years were analyzed and compared with results in patients aged <45 years. METHODS: Between January 1980 and August 2002, 319 consecutive older patients (group A) and 497 young patients AVR. Preoperative clinical data, early and late mortality, valve-related complications and data related to anticoagulation status (including mean INR and mean interval between INR assays) were compared between groups. RESULTS: Hospital mortality was lower in group B (3.4%) than in group A (10.7%; p <0.0001). Twelve-year actuarial survival was lower in older patients (54% in group A versus 78% in group B; p <0.001). The two groups showed similar 12-year actuarial freedom from hemorrhage (99.6% versus 99.5%; p = 0.69), endocarditis (99.6% versus 98.43%; p = 0.25) and perivalvular leak (99.6% versus 97.9%; p = 0.21). However, actuarial freedom from thromboembolism was lower in older patients (98.8% versus 99.7%; p = 0.041). CONCLUSION: Despite lower rates of long-term mortality and thromboembolism (the latter because of advanced atherosclerosis) in group A, there were no differences in rates of other valve-related complications. Hence, older age cannot be considered a contraindication to implantation of mechanical valves in the aortic position.     

IMPACT Trial: angiographic and intravascular ultrasound observations of the first human experience with mycophenolic acid-eluting polymer stent system.

The purpose of the study was to examine the safety and efficacy of two different formulations of mycophenolic acid (MPA)-eluting Duraflex stents on coronary de novo lesions. Recent data indicate that local delivery of MPA in the porcine overstretch coronary model significantly reduces neointimal hyperplasia (NIH). Patients were divided into three consecutive groups. The first (n=50) and second (n=55) groups received moderate- and slow-release MPA-eluting Duraflex stent, respectively. The last group (n=50) received the bare metal Duraflex stent. Clinical, angiographic, and intravascular ultrasound analysis were performed at 6-month follow-up. All stents were successfully deployed and patients were discharged home without clinical events. Compared to controls, 6-month in-lesion and in-stent minimum luminal diameter as well as late lumen loss were not significantly different in the moderate- and slow-release treatment groups. At follow-up, percentage obstruction and NIH volume were also similar between the three groups. At 30 days and 6 and 12 months, there were no differences noted between the three groups with respect to major adverse cardiac events as well as the individual rates of mortality, myocardial infarction, or repeat revascularization. There were no cases of subacute or late thrombosis. In this feasibility trial, the MPA-eluting Duraflex stents in either slow- or moderate-release formulations were well tolerated, but showed no benefit for treatment of coronary lesions when compared to controls. Further testing with different drug dosing or delivery rate might improve these results.     

Humoral immune response to measles and varicella vaccination in former very low birth weight preterm infants

Introduction

Immune response to vaccination in infants born prematurely may be lower than in infants born at full-term. Some clinical factors might be associated with humoral immune response.