Activity of Praziquantel Enantiomers and Main Metabolites against Schistosoma mansoni

A racemic mixture of R and S enantiomers of praziquantel (PZQ) is currently the treatment of choice for schistosomiasis. Though the S enantiomer and the metabolites are presumed to contribute only a little to the activity of the drug, in-depth side-by-side studies are lacking. The aim of this study was to investigate the in vitro activities of PZQ and its main metabolites, namely, R- and S-cis- and R- and S-trans-4′-hydroxypraziquantel, against adult worms and newly transformed schistosomula (NTS). Additionally, we explored the in vivo activity and hepatic shift (i.e., the migration of the worms to the liver) produced by each PZQ enantiomer in mice. Fifty percent inhibitory concentrations of R-PZQ, S-PZQ, and R-trans- and R-cis-4′-hydroxypraziquantel of 0.02, 5.85, 4.08, and 2.42 μg/ml, respectively, for adult S. mansoni were determined in vitro. S-trans- and S-cis-4′-hydroxypraziquantel were not active at 100 μg/ml. These results are consistent with microcalorimetry data and studies with NTS. In vivo, single 400-mg/kg oral doses of R-PZQ and S-PZQ achieved worm burden reductions of 100 and 19%, respectively. Moreover, worms treated in vivo with S-PZQ displayed an only transient hepatic shift and returned to the mesenteric veins within 24 h. Our data confirm that R-PZQ is the main effector molecule, while S-PZQ and the metabolites do not play a significant role in the antischistosomal properties of PZQ.     

Análisis del polimorfismo rs20541 (R130Q) del gen de la IL-13 en pacientes con enfermedades inflamatorias crónicas asociadas al envejecimiento

ObjectiveTo investigate whether there is association between the rs20541 (R130Q) polymorphism in the IL-13 gene with disease susceptibility and clinical subsets in patients with elderly-associated inflammatory chronic diseases.Material and methods78 patients with giant cell arteritis (GCA), 174 with polymyalgia rheumatica (PMR), 90 elderly-onset rheumatoid arthritis (EORA), and 465 healthy controls from the same geographic area were studied. The rs20541 (R130Q) polymorphism in the IL-13 gene was evaluated by PCR-RFLP. Circulating levels of IL-13 were measured by ELISA.ResultsA higher frequency of the AA genotype [2.349 (0.994-5.554)], as well as the allele A [1.589 (1.085-2.328] and the A carriers [1.656 (1.021-2.686)] (p < 0.05) was observed in the GCA patients. No significant differences were observed in the PMR and EORA patients as compared with the healthy controls. Neither difference was observed among the different disease groups studied. In GCA patients, differences in the genotype were associated with a worse prognosis. In PMR patients, the AA genotype was associated with higher levels of serum IL-13 than the GA one. However, such an association was not detected for controls and the other disease groups.ConclusionsGCA is more frequent in carriers of the rs20541 (R130Q) polymorphism in the IL-13 gene. The utility of this polymorphism to predict the GCA prognosis must be confirmed in studies with a higher number of patients.     

Estratificación basal de riesgo en pacientes mayores de 75 años con infarto y shock cardiogénico referidos para angioplastia primaria

Background and objectivesPatients older than 75 years with ST-segment elevation myocardial infarction undergoing primary angioplasty in cardiogenic shock have high mortality. Identification of preprocedural predictors of short- and long-term mortality could be useful to guide decision-making and further interventions.MethodsWe analyzed a nationwide registry of primary angioplasty in the elderly (ESTROFA MI + 75) comprising 3576 patients. The characteristics and outcomes of the subgroup of patients in cardiogenic shock were analyzed to identify associated factors and prognostic predictors in order to derive a baseline risk prediction score for 1-year mortality. The score was validated in an independent cohort.ResultsA total of 332 patients were included. Baseline independent predictors of mortality were anterior myocardial infarction (HR 2.8, 95%CI, 1.4-6.0; P = .005), ejection fraction < 40% (HR 2.3, 95%CI, 1.14-4.50; P = .018), and time from symptom onset to angioplasty > 6 hours (HR 3.2, 95%CI, 1.6-7.5; P = .001). A score was designed that included these predictive factors (score “6-ANT-40”). Survival at 1 year was 54.5% for patients with score 0, 32.3% for score 1, 27.4% for score 2 and 17% for score 3 (P = .004, c-statistic 0.70). The score was validated in an independent cohort of 124 patients, showing 1-year survival rates of 64.5%, 40.0%, 28.9%, and 22.2%, respectively (P = .008, c-statistic 0.68).ConclusionsA preprocedural score based on 3 simple clinical variables (anterior location, ejection fraction < 40%, and delay time > 6 hours) may be used to estimate survival after primary angioplasty in elderly patients with cardiogenic shock and to guide preinterventional decision-making.     

Calcimimetics maintain bone turnover in uremic rats despite the concomitant decrease in parathyroid hormone concentration

1. Download high-res image (408KB)
2. Download full-size image