Synthesis of cytotoxic 6E-hydroximino-4-ene steroids: structure/activity studies

In an effort to determine the pharmaceutical utility and the structural requirements for activity against various tumor cell lines, several 6E-hydroximino-4-ene steroids with different side chains and degrees of unsaturation on ring A were synthesized in our laboratory. Evaluation of the synthesized compounds for cytotoxicity against P-388, A-549, HT-29, and MEL-28 tumor cells revealed that some important structural features are required for activity. The presence of a cholesterol-type side chain, which appears to play a major role in determining the biological activity, the existence of a ketone functionality at C-3, and an elevated degree of oxidation on ring A all result in higher bioactivity than other structural motifs.     

C-phycocyanin protects cerebellar granule cells from low potassium/serum deprivation-induced apoptosis

We tested the potential cytoprotective role of C-phycocyanin in rat cerebellar granule cell cultures. Cell death was induced by potassium and serum (K/S) withdrawal. Cell viability was studied using the neutral red assay and laser scanning cytometry with propidium iodide as fluorochrome. C-phycocyanin (1-3 mg/ml) showed a neuroprotective effect against 24 h of K/S deprivation in cerebellar granule cells. After 4 h K/S deprivation this compound (3 mg/ml) inhibited formation of reactive oxygen species, measured as 2',7'-dichlorofluorescein fluorescence, showing its scavenger capability. Pre-treatment with C-phycocyanin reduced thymidine incorporation into DNA below control values and reduced dramatically apoptotic bodies as visualized by propidium iodide, indicating inhibition of apoptosis induced by K/S deprivation. Flow cytometry studies, using propidium iodide in TritonX100 permeabilized cells, indicated that 24 h K/S deprivation acts as a proliferative signal for cerebellar granule cells, which show an increase in S-phase percentage and cells progressed into the apoptotic pathway. C-phycocyanin protected cerebellar granule cells from the apoptosis induced by deprivation. These results suggest that C-phycocyanin prevents apoptosis in cerebellar granule cells probably through the antioxidant activity. It is proposed that K/S deprivation-induced apoptosis could be due, in part, to an alteration in the cell cycle mediated by an oxidative stress mechanism.     

The effects of sodium arsenite exposure on behavioral parameters in the rat

Arsenic is a metalloid widely present in the environment. It is found in well water, soil, and air, and is also released from mining residues and industrial debris, among other anthropogenic sources. It has been previously reported that the content of catecholamines in striatum, hippocampus, and other cerebral regions changes in mice and rats exposed to arsenic. Few studies have examined behavioral alterations after intoxication with arsenic, and both increased and decreased locomotor activity, as well as learning deficits, have been described. In order to characterize the behavioral alterations induced by arsenic exposure, we exposed adult male Sprague-Dawley rats to 5, 10, and 20 mg/kg of arsenic by intragastric route for 2 or 4 weeks. Exposed rats showed reduced locomotor activity, which returned to control levels at the end of the intoxication period. We also found an increase in the number of errors in an egocentric task, alterations in monoamine content in midbrain and cortex, and increases in arsenic brain concentration, which were related to time of the exposure but not dose. These results indicate that short-term arsenic exposure induces neural and behavioral changes that may reflect a neurotoxic effect, and that these alterations are correlated to dose, time of exposure, and experimental conditions.     

Clinical practice guidelines of the Spanish Society of Cardiology for pulmonary thromboembolism and hypertension

Primary pulmonary hypertension is a progressive disease. Most affected patients are young and middle-aged women. Etiology is unknown, although a familial and genetic factor is present in up to 6% of cases. Endothelial dysfunction and abnormalities in calcium channels of smooth muscle fibers are the present pathogenetics theories. Diagnostic tests try to exclude secondary causes of pulmonary hypertension and to evaluate its severity. Acute vasodilatory test is vital in the selection of treatment. Oral anticoagulation is indicated in all patients. Lung transplant is performed when medical treatment is unsuccessful. Atrial septostomy is an alternative and palliative treatment for selected cases. Chronic thromboembolic pulmonary hypertension is a special form of secondary pulmonary hypertension, clinically undistinguishable from primary primary hypertension, is of mandatory diagnosis because it can be cured with thromboembolectomy.Pulmonary embolism is common in hospitalised patients. The mortality rate for pulmonary embolism continues to be high: up to 30% in untreated patients. The accurate detection of pulmonary embolism remains difficult, as pulmonary embolism can accompany as well as mimic other cardiopulmonary illnesses. Non-invasive diagnostic tests have poor specificity and sensitivity. The D-dimer level and the spiral CT angiography have also been employed as new alternatives and important tools for precise diagnosis of suspected pulmonary embolism. The standard therapy of pulmonary embolism is intravenous heparin for 5 to 10 days in conjunction with oral anticoagulants posteriorly for 3 to 6 months. The incidence of deep venous thrombosis, pulmonary embolism and death due to pulmonary embolism, can be reduced significantly and shown clear benefits only by adoption of a prophylactic strategy with low-molecular-weight-heparins or dextrans in patients at risk.