Oxidative stress-dependent MMP-13 activity underlies glucose neurotoxicity

Background

A complication of diabetes is neuropathy, a condition of sensory axon degeneration that originates in the epidermis. The mechanisms remain unknown but reactive oxygen species (ROS) have been implicated in this condition. In this study, we assessed the role of ROS and a candidate downstream target, MMP-13 in glucose-induced sensory axon degeneration in zebrafish and mice.

A rare coexistence of primary hyperparathyroidism and hyperthyroidism due to toxic nodular goiter--a case report

The frequent association of thyroid and parathyroid disorders has been reported. Most commonly, hyperthyroidism may coexist with hypercalcemia, but the latter is successfully treated when euthyroidism is achieved. However, the concomitant hyperthyroidism with primary hyperparathyroidism is of a rare occurrence. Moreover, it may frequently go unrecognized. In this paper we report a case of a patient with hypercalcemia due to PTH--secreting parathyroid adenoma associated with hyperthyroidism due to toxic nodular goiter. This case demonstrates the dramatic outcome of those two coexisting disorders. We point out that in patients with primary hyperparathyroidism thyroid function test should always be carried out. A proper, first-line treatment of hyperthyroidism will prevent the deterioration of primary hyperparathyroidism course, and thus surgical parathyroid treatment may safely be introduced.     

Surgical treatment for hypertrophic obstructive cardiomyopathy

INTRODUCTION AND OBJECTIVES: Five percent of the patients with hypertrophic obstructive cardiomyopathy (HOCM) have symptoms unresponsive to medical treatment and are candidates for invasive therapy. The objective of this study was to analyze our results with surgical treatment of HOCM during the last 10 years. PATIENTS AND METHOD: Between July 1993 and January 2004 26 patients with HOCM refractory to drug therapy were operated on. An extended septal myectomy was performed, in combination with anterior mitral leaflet plication in 19 cases (73%) and with mitral valve replacement in 5 (19%). Evolution of the grade of dyspnea, left ventricle outflow tract gradient (LVOTG), mitral regurgitation, and systolic anterior motion after surgery was analyzed. RESULTS: Mean follow-up was 63 (37) months. After surgery, a significant reduction in LVOTG (from 96.5 to 19.5 mmHg; P<.001), grade of mitral regurgitation (from 2.54 to 0.69; P<.001) and systolic anterior motion (from 2.92 to 0.23; P<.001) was achieved, which led to improvement in functional class. Hospital mortality and need for pacemaker implantation due to complete heart block after surgery was 3.8% (n=1). There were no cases of iatrogenic ventricular septal defect or mitro-aortic valve injury. Actuarial survival at 5 years was 96% (4%). CONCLUSIONS: Surgery in patients with HOCM yields great clinical improvements with low morbidity and mortality. Simultaneous intervention for both myocardial and valvular components of the disease allows not only reduction in the LVOTG but also correction of mitral regurgitation and abolition of systolic anterior motion.     

Amiodarone induced pneumonitis and hyperthyroidism: case report

Amiodarone is a highly effective antiarrhythmic agent used in life-threatening ventricular and supraventricular arrhythmias. Its long-term use may however lead to several adverse effects, including corneal deposits, liver and thyroid gland dysfunction, lung lesions, bone marrow injury, skin lesions, or neurological abnormalities. The article presents the case of a 56-year-old man with a history of a stroke, who after a few days of amiodarone therapy for an episode of atrial fibrillation was diagnosed with amiodarone-induced hyperthyroidism and interstitial pulmonary lesions. Clinical and laboratory symptoms of hyperthyroidism and radiographic signs of pulmonary involvement did not occur until several weeks after discontinuation of amiodarone therapy. Differential diagnosis of causes of hyperthyroidism and diseases causing nodular pulmonary lesions did not demonstrate any other pathologies. Empirical antibiotic therapy and administration of thiamazole and high doses of propranolol failed to improve the patient's clinical status. It was not until thiamazole was given in combination with glucocorticosteroids, when a slow relief of hyperthyroidism symptoms and resolution of radiographic pulmonary signs were observed. Based on the presented case, the risk of appearance of 2 serious concomitant adverse effects was demonstrated, even following a short-term amiodarone therapy. This paper also contains an overview of adverse effects which may be encountered during or after therapy with this effective antiarrhythmic agent. It was emphasized how important it is to select patients appropriately, and to monitor potential adverse effects during amiodarone therapy.     

Association of coronary atherosclerosis with insulin resistance in patients with impaired glucose tolerance

OBJECTIVES: The purpose of the study was to evaluate the role of insulin resistance (IR) in the development of coronary atherosclerosis in patients with impaired glucose tolerance. METHODS AND RESULTS: The study group consisted of 42 patients with impaired glucose tolerance. Based upon coronary angiography the patients were divided into group A--with prior myocardial infarction and critical coronary stenosis (n=20) and group B--without prior myocardial infarction and without critical coronary stenosis (n=22). In each patient glucose disposal rate (GDR) during metabolic clamp, insulinaemia in the fasting state and during the clamp, glycaemia during oral glucose tolerance test (OGTT), BMI and body mass composition were measured. The groups did not differ in age, BMI, percent fat content and distribution, and blood pressure. Fasting insulinaemia (56.7 microU/ml) was higher in group A than in group B (22.3 microU/ml). GDR in group A (2.96 mg/kg b.m./min) was lower than in group B (5.36 mg/kg b.m./min). There was a negative correlation between the number of critically narrowed coronary vessels and GDR in group A. GDR below 3.97 mg/kg b.m./min was found, based on regression analysis, to be a powerful risk factor for myocardial infarction. CONCLUSIONS: The relationship between IR and severity of coronary atherosclerosis implies its unfavourable role in the development of atherosclerosis. The present findings indicate a negative role of IR in the development of myocardial infarction and suggest that it is an independent risk factor, which identifies high-risk patients requiring treatment that would increase tissue insulin sensitivity.     

The Influence of Curing Systems on the Cure Characteristics and Physical Properties of Styrene–Butadiene Elastomer

The goal of this work is to study the influence of different curing systems on the cure characteristics and performance of styrene–butadiene elastomer (SBR) filled with carbon black or nanosized silica. A multifunctional additive for rubber compounds, namely Activ8, was applied as an additional activator and accelerator to increase the efficiency of sulfur vulcanization and to reduce the content of zinc oxide elastomers cured in the presence of 2-mercaptobenzothizole or 1,3-diphenylguanidine as a primary accelerator. The influence of the curing system composition on the crosslink density and physical properties of SBR vulcanizates, such as mechanical properties, thermal stability, and resistance to thermo-oxidative aging, is also reported. Activ8 effectively supports the vulcanization of SBR compounds, especially filled with nanosized silica. It reduces the optimal vulcanization time of SBR compounds and increases the crosslink density of the vulcanizates. Moreover, vulcanizates with Activ8 exhibit higher tensile strength and better damping properties than elastomer with zinc oxide. Activ8 allows the amount of ZnO to be reduced by 40% without detrimental effects on the crosslink density and mechanical performance compared to the vulcanizates conventionally crosslinked with ZnO. This is an important ecological goal since ZnO is classified as being toxic to aquatic species.