Selective Decrease of Components of the Creatine Kinase System and ATP Synthase Complex in Chronic Chagas Disease Cardiomyopathy

Chronic Chagas disease cardiomyopathy (CCC) affects millions in endemic areas and is presenting in growing numbers in the USA and European countries due to migration currents. Clinical progression, length of survival and overall prognosis are significantly worse in CCC patients when compared to patients with dilated cardiomyopathy of non-inflammatory etiology. Impairment of energy metabolism seems to play a role in heart failure due to cardiomyopathies. Herein, we have analyzed energy metabolism enzymes in myocardium samples of CCC patients comparing to other non-inflammatory cardiomyopathies. We found that myocardial tissue from CCC patients displays a significant reduction of both myocardial protein levels of ATP synthase alpha and creatine kinase enzyme activity, in comparison to control heart samples, as well as idiopathic dilated cardiomyopathy and ischemic cardiomyopathy. Our results suggest that CCC myocardium displays a selective energetic deficit, which may play a role in the reduced heart function observed in such patients

Ultra-performance liquid chromatography/tandem mass spectrometry method for the determination of lercanidipine in human plasma

A simple, sensitive and rapid ultra-performance liquid chromatography/ positive electrospray ionization tandem mass spectrometry (UPLC/ESI-MS/MS) method has been developed and validated for the determination of lercanidipine in human plasma. Lercanidipine and the internal standard, nicardipine, were extracted from plasma by liquid-liquid extraction using tert-butyl methyl ether as the extraction solvent. UPLC analysis was performed isocratically on an AcQuity UPLC™ BEH C18 analytical column (2.1 X 50.0 mm i.d., particle size 1.7 μm). The mobile phase consisted of 70% acetonitrile in water containing 0.2% v/v formic acid and pumped at a flow rate of 0.30 mL/min. ESI in positive ion mode, with multiple reaction monitoring (MRM), was chosen for the detection of the analytes. The assay was linear over a concentration range of 0.05-30 ng/mL for lercanidipine with a limit of quantitation of 0.05 ng/mL. Quality control samples (0.05, 0.15, 15 and 25 ng/mL) in five replicates from five of analytical runs demonstrated intra-assay precision (% CV ≤7.3%), inter-assay precision (% CV ≤6.1%) and an overall accuracy (% relative error) of less than 6.2%. A run time of less than 1.0 min for each sample made it possible to analyze a large number of human plasma samples per day. The method can be used to quantify lercanidipine in human plasma covering a variety of pharmacokinetic or bioequivalence studies. Copyright © 2006 John Wiley & Sons, Ltd

Porphyrin‐containing glycodendrimers

Two dendrimers, incorporating tetrasubstituted porphyrin units as their cores and, in one case, four perbenzoylated and, in the other case, twelve peracetylated β‐D‐glucopyranosyl residues at their peripheries, have been synthesized in yields of 39 and 16%, respectively. The deprotection of these dendrimers was achieved quantitatively under Zemplén conditions. The protected and deprotected dendrimers were characterized by liquid secondary‐ion or matrix‐assisted laser desorption ionization time‐of‐flight mass spectrometry and by a combination of one‐ and two‐dimensional 1H and 13C NMR spectroscopy. All the glycodendrimers were also characterized by absorption and emission spectroscopy, and lifetime measurements. The most relevant result is that both protected and deprotected dendrimers show two fluorescence lifetime values that are different from the porphyrin model compounds. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003

Bone resorption is increased in young adults with thalassaemia major

Bone disease in patients with thalassaemia major is a multifactorial and still poorly understood process. The present study evaluated 45 thalassaemic patients using dual X-ray absorptiometry at three sites (lumbar spine, head of femur and forearm) to assess bone mineral density, in parallel with a series of biochemical markers to measure bone formation and bone resorption. To identify possible interfering factors, our patients were grouped according to whether or not they needed transfusion therapy; the presence of hypogonadism was also considered. Our results showed that patients on regular transfusions had a markedly low bone mineral density in contrast to those not requiring blood support and that this finding was more pronounced in the hypogonadic group, irrespectively of sex. The decrease of bone mineral density values was more prominent in the forearm, thus making this site particularly interesting for such studies. Bone formation, as evidenced by the levels of serum alkaline phosphatase and osteocalcin, did not appear to be impaired, while bone resorption was grossly increased in all patient groups. The latter process was clearly evident using the recently introduced measurement of the urinary N-terminal peptides of collagen type I, the sensitivity of which has already been established in other groups of osteoporotic patients. Our conclusion is that, in spite of the severe bone destruction that occurs in thalassaemia major, the fact that bone formation remains intact calls for a more intensive treatment comprising hormonal replacement, bisphosphonates and other agents

Protein fucosylation regulates synapsin Ia/Ib expression and neuronal morphology in primary hippocampal neurons

Although fucose-α(1-2)-galactose [Fucα(1-2)Gal] carbohydrates have been implicated in cognitive processes such as long-term memory, the molecular mechanisms by which these sugars influence neuronal communication are not well understood. Here, we present molecular insights into the functions of Fucα(1-2)Gal sugars, demonstrating that they play a role in the regulation of synaptic proteins and neuronal morphology. We show that synapsins Ia and Ib, synapse-specific proteins involved in neurotransmitter release and synaptogenesis, are the major Fucα(1-2)Gal glycoproteins in mature cultured neurons and the adult rat hippocampus. Fucosylation has profound effects on the expression and turnover of synapsin in cells and protects synapsin from degradation by the calcium-activated protease calpain. Our studies suggest that defucosylation of synapsin has critical consequences for neuronal growth and morphology, leading to stunted neurite outgrowth and delayed synapse formation. We also demonstrate that Fucα(1-2)Gal carbohydrates are not limited to synapsin but are found on additional glycoproteins involved in modulating neuronal architecture. Together, our studies identify important roles for Fucα(1-2)Gal sugars in the regulation of neuronal proteins and morphological changes that may underlie synaptic plasticity