Atherothrombosis: role of tissue factor; link between diabetes, obesity and inflammation.

Atherothrombotic vascular disease is a complex disorder in which inflammation and coagulation play a pivotal role. Rupture of high-risk, vulnerable plaques with the subsequent tissue factor (TF) exposure is responsible for coronary thrombosis, the main cause of unstable angina, acute myocardial infarction, and sudden cardiac death. Tissue factor (TF), the key initiator of coagulation is an important modulator of inflammation. TF is widely expressed in atherosclerotic plaques and found in macrophages, smooth muscle cells, extracellular matrix and acellular lipid-rich core. TF expression can be induced by various stimulants such as C-reactive protein, oxLDL, hyperglycemia and adipocytokines. The blood-born TF encrypted on the circulating microparticles derived from vascular cells is a marker of vascular injury and a source of procoagulant activity. Another form of TF, called alternatively spliced has been recently identified in human and murine. It is soluble, circulates in plasma and initiates coagulation and thrombus propagation. Evidence indicates that elevated levels of blood-borne or circulating TF has been associated with metabolic syndrome, type 2 diabetes and cardiovascular risk factors and is a candidate biomarker for future cardiovascular events. Therapeutic strategies have been developed to specifically interfere with TF activity in the treatment of cardiovascular disease.

Inflammation and neovascularization in diabetic atherosclerosis.

Diabetes mellitus, the major cardiovascular risk factor, accentuates the inflammation and neovascularization processes leading to enhanced progression of atherosclerotic complications. Inflammation in diabetes mellitus is the key initiator of atherosclerotic process, which results in acute coronary events. Atherosclerosis evolves from the endothelial cell dysfunction and succeeding entry of hemodynamically derived leukocytes by migration, activation and production of lipid gruel leading to atheromatous plaque progression and subsequent regression. Diabetic plaque progression is associated with increased neovascularization, which is a nature's compliment in the sustenance of plaque growth by its nutrient supply. Neovessels may act as conduit for lipid debridment and alternative channel for inflammatory process. In addition, neovascularization induces intra-plaque hemorrhage due to the fragility of the neovessels and associated inflammation, resulting in plaque instability. The intra-plaque hemorrhage is a detrimental base, which begets the progress of atheroma by inducing oxidative stress and endothelial dysfunction. Intra-plaque hemorrhage is increased in diabetes with an associated increase in hemoglobin-haptoglobin complex (Hb-Hp2-2), which further induces oxidative stress and endothelial cell dysfunction. We conclude that inflammation and neovascularization of the plaque may act as major mechanism augmenting plaque instability in diabetes mellitus.

Photodegradation of sparfloxacin and isolation of its degradation products by preparative HPLC

Sparfloxacin, a third generation fluoroquinolone derivative, is a potent antibacterial agent active against a wide range of Gram-positive and Gram-negative organisms including Streptococcus pneumoniae, Staphylococcus aureus, methicillin resistant S. aureus, Legionella spp., Mycoplasma spp., Chlamydia spp. and Mycobacterium spp. A drawback of fluoroquinolones is their photoreactivity. Sparfloxacin has been studied in terms of therapeutic activities. However, there are few published of analytical methods being applied to sparfloxacin. The aim in this study was to determine the photodegradation products of sparfloxacin, when submitted to UV light, and to characterize two of these products, designated SPAX-PDP1 and SPAX-PDP2. An accelerated study of stability in methanol solution was carried out by exposing a solution of sparfloxacin to UV light (peak wavelength 290 nm) for 36 hours at room temperature. The products were analyzed by NMR spectrophotometry, IR spectrometry and mass spectrophotometry. The results suggest that the products isolated here could be used to estimate the degradation of sparfloxacin in a stability study. However, the low activity exhibited by UV-irradiated sparfloxacin is a source of concern that demands further investigation of the mechanism of its photodegradation mechanism

La infiltración de macrófagos en las lesiones coronarias primarias está asociada con reestenosis luego de la intervención coronaria percutánea / Macrophage infiltration in primary coronary plaque tissue is associated with restenosis after percutaneous coronary intervention

Se le realizó aterectomía direccional coronaria de la lesión culposa a 50 pacientes sintomáticos por angina inestable. Se tiñeron las muestras obtenidas con hematoxilina-eosina, tinción tricrómica y con anticuerpos monoclonales antimacrófagos humanos (Kp-1). El seguimiento angiográfico fue de 16 ñ 2 semanas. Treinta pacientes evolucionaron a reestenosis y 20 pacientes sin reestenosis (grupo control). El porcentaje de áreas ricas en macrófagos fue significativamente mayor en las placas de pacientes con reestenosis (19 ñ 3 por ciento) que en las placas sin reestenosis (10,3 ñ 3 por ciento) (p= 0,005). Este incremento del contenido de macrófagos sugiere que células inflamatorias estarían involucradas en el complejo mecanismo de la reestenosis luego de la intervención coronaria percutánea

Genotoxic effect of alkaloids

Because of the increase use of alkaloids in general medical practice in recent years, it is of interest to determine genotoxic, mutagenic and recombinogenic response to different groups of alkaloids in prokaryotic and eucaryotic organisms. Reserpine, boldine and chelerythrine did not show genotoxicity response in the SOS-Chromotest whereas skimmianine showed genotixicity in the presence of a metabolic activation mixture. Voacristine isolated fromthe leaves of Ervatamia coronaria shows in vivo cytostatic and mutagenic effects in Saccharomyces cerevisiae hapioids cells. The Rauwolfia alkaloid (reserpine) was not able to induce reverse mutation and recombinational mitotic events (crossing-over and gene conversion) in yeast diploid strain XS2316.