Study of Adsorption and Flocculation Properties of Natural Clays to Remove Prorocentrum lima

High accumulations of phytoplankton species that produce toxins are referred to as harmful algal blooms (HABs). HABs represent one of the most important sources of contamination in marine environments, as well as a serious threat to public health, fisheries, aquaculture-based industries, and tourism. Therefore, methods effectively controlling HABs with minimal impact on marine ecology are required. Marine dinoflagellates of the genera Dinophysis and Prorocentrum are representative producers of okadaic acid (OA) and dinophysistoxins responsible for the diarrhetic shellfish poisoning (DSP) which is a human intoxication caused by the consumption of shellfish that bioaccumulate those toxins. In this work we explore the use of natural clay for removing Prorocentrum lima. We evaluate the adsorption properties of clays in seawater containing the dinoflagellates. The experimental results confirmed the cell removal through the flocculation of algal and mineral particles leading to the formation of aggregates, which rapidly settle and further entrain cells during their descent. Moreover, the microscopy images of the samples enable one to observe the clays in aggregates of two or more cells where the mineral particles were bound to the outer membranes of the dinoflagellates. Therefore, this preliminary data offers promising results to use these clays for the mitigation of HABs.     

Acute glomerulonephritis associated with pneumonia: a review of three cases

We evaluated the clinical presentation and prognosis of three children with acute glomerulonephritis (AGN) associated with pneumonia. The patient database of Niño Jesús Children’s Hospital was analyzed retrospectively (1996–2007) for patients diagnosed at discharge with both pneumonia and AGN. Those with recent pharyngeal or cutaneous infection were excluded. Three patients (1.67, 4.25, and 5 years old, respectively) were selected. All of them had lobar pneumonia, developing both macrohematuria and proteinuria within 24 h after admission. Decreased glomerular filtration rate was found in one patient. Two children developed arterial hypertension and one a slight pleural effusion. Two children had low C3 levels, and one had both low C3 and C4 levels. A Streptococcus pneumoniae serotype 17F was isolated from the blood culture of one patient. On follow-up, all patients had normal blood pressure and renal function with microhematuria persisting long term. Our patients with pneumonia-associated AGN had a good prognosis for both pulmonary and renal involvement.     

Medical and surgical treatment of varicocele

OBJECTIVES: Varicocele is a dilation of the pampiniform venous plexus in the spermatic cord. It appears in 15% approximately of general population males. It is the most commonly identifiable, surgically treatable lesion associated with male infertility. The surgical treatment of varicocele, either unilateral or bilateral, has demonstrated a significant improvement in seminal parameters at least in two-thirds of affected males, and 30% to 60% pregnancy rates. There are many controversies about the indication of surgical treatment, more popular than percutaneous embolization, because several series have not demonstrated clear benefit; nevertheless, most authors support surgery, because its low morbidity, it is easy to perform, has a rapid adaptation process, and improves seminal parameters in most cases, or at least prevents their progressive impairment observed when surgery is not performed.     

Taxanes: microtubule and centrosome targets,and cell cycle dependent mechanisms of action

Microtubules are highly dynamic cellular polymers made of alphabeta-tubulin and associated proteins. They play a key role during mitosis, participating in the exact organization and function of the spindle, and are critical for assuring the integrity of the segregated DNA. Therefore, they represent one of the more effective targets in current cancer therapy. Paclitaxel (Taxol) is the prototype of the taxane family of antitumor drugs, and it was the first natural product shown to stabilize microtubules. This unique mechanism of action is in contrast to other microtubule poisons, such as Vinca alkaloids, colchicine, and cryptophycines, which inhibit tubulin polymerization. Taxanes block cell cycle progression through centrosomal impairment, induction of abnormal spindles and suppression of spindle microtubule dynamics. Triggering of apoptosis by aberrant mitosis or by subsequent multinucleated G1-like state related to mitotic slippage, depends on cell type and drug schedule. The development of fluorescent derivatives of paclitaxel led us to locate spindle pole microtubules and centrosomes as main sub-cellular targets of cytotoxic taxoids in living cells. In this review we discuss these findings in the context of a cell cycle-dependent response to taxanes, based on the cellular targets, and the status of the implicated cell cycle checkpoints. We also review those events that can influence this response, like the different signal transduction pathways activated/inactivated in relation to Bcl-2 phosphorylation and induction of apoptosis, and the controversial role of the p53 status on cell sensitivity to paclitaxel. Finally, cell cycle-dependent resistance, an emerging concept in combination sequential chemotherapy, is discussed on the basis of the cell cycle-dependent mechanisms of action of taxanes.     

Involvement of phenoxyl radical intermediates in lipid antioxidant action of myricetin in iron-treated rat hepatocyte culture

Supplementation of rat hepatocyte cultures with the flavonoid myricetin (300 microM) led to the formation of phenoxyl radical intermediates, as detected in intact cells by electron paramagnetic resonance (EPR) spectroscopy. These radicals corresponded to one-electron oxidation products of myricetin. The level of phenoxyl radicals was significantly reduced when myricetin-treated hepatocyte cultures were also supplemented with iron (Fe-NTA 100 microM). This suggested that iron could accelerate the oxidation flux of myricetin. Moreover, myricetin was found to be able to inhibit lipid peroxidation induced by iron in hepatocyte culture. Free malondialdehyde (MDA) levels and the amount of radicals derived from oxidized lipids were greatly reduced when myricetin was added to iron-treated cultures. This showed that myricetin was a good inhibitor of lipid peroxidation in this model and that the intermediate generation of phenoxyl radicals might contribute to the antioxidant mechanism of myricetin.