Assessing the reaction to and efficacy of the Screener drug discovery and development board game as a pedagogical tool in postgraduate courses

Screener, a board game supplemented with online resources, was introduced and distributed by the Brazilian Society of Pharmacology and Experimental Therapeutics to postgraduate programs as an instructional tool for the process of drug discovery and development (DDD). In this study, we provided a comprehensive analysis of five critical aspects for evaluating the quality of educational games, namely: 1) description of the intervention; 2) underlying pedagogical theory; 3) identification of local educational gaps; 4) impact on diverse stakeholders; and 5) elucidation of iterative quality enhancement processes. We also present qualitative and quantitative assessments of the effectiveness of this game in 11 postgraduate courses. We employed the MEEGA+ online survey, comprising thirty-three close-ended unipolar items with 5-point Likert-type response scales, to assess student perceptions of the quality and utility of Screener. Based on 115 responses, the results indicated a highly positive outlook among students. In addition, we performed a preliminary evaluation of learning outcomes in two courses involving 28 students. Pre- and post-quizzes were applied, each consisting of 20 True/False questions directly aligned with the game's content. The analysis revealed significant improvement in students' performance following engagement with the game, with scores rising from 8.4 to 13.3 (P<0.0001, paired t-test) and 9.7 to 12.7 (P<0.0001, paired t-test). These findings underscore the utility of Screener as an enjoyable and effective tool for facilitating a positive learning experience in the DDD process. Notably, the game can also reduce the educational disparities across different regions of our continental country.

SCREENER, an educational game for teaching the Drug Discovery and Development process

Although the use of games as an educational strategy is an important current trend, there is practically no option available for training people on the Drug Discovery and Development (DDD) process. To fill this gap, we designed "SCREENER", a science game that is intended to be educational, but also challenging and interesting enough to ensure player engagement. Our main target audience is students of postgraduate programs in pharmacology, medicinal chemistry, pharmacy, and medicine. This game could also be of interest to the pharmaceutical industry and regulatory and patent agencies for training new employees. We discuss the creation of SCREENER, a hybrid of board and card games, and present its components with some examples of cards and resources, as well as the dynamics of the game. SCREENER mimics the process of drug discovery and development from validating a target to registering the new drug with the regulatory agency, and can be played individually (self-learning) or with the help of a monitor who assists up to six players/teams. Briefly, 29 task cards categorized in four major areas (efficacy, safety, pharmacokinetics, and pharmaceutical development) must be purchased sequentially. Classic characteristics of games such as decision making and challenge have been incorporated. More in-depth information on the tasks and technical terms is available through QR codes. The vagaries of the DDD process are mimicked by the bonus/setback cards. The evaluation of our first test with students is presented and supports the usefulness of this new tool.

ADME studies and preliminary safety pharmacology of LDT5, a lead compound for the treatment of benign prostatic hyperplasia

This study aimed to estimate the absorption, distribution, metabolism and excretion (ADME) properties and safety of LDT5, a lead compound for oral treatment of benign prostatic hyperplasia that has previously been characterized as a multi-target antagonist of α1A-, α1D-adrenoceptors and 5-HT1A receptors. The preclinical characterization of this compound comprised the evaluation of its in vitro properties, including plasma, microsomal and hepatocytes stability, cytochrome P450 metabolism and inhibition, plasma protein binding, and permeability using MDCK-MDR1 cells. De-risking and preliminary safety pharmacology assays were performed through screening of 44 off-target receptors and in vivo tests in mice (rota-rod and single dose toxicity). LDT5 is stable in rat and human plasma, human liver microsomes and hepatocytes, but unstable in rat liver microsomes and hepatocytes (half-life of 11 min). LDT5 is highly permeable across the MDCK-MDR1 monolayer (Papp ∼32×10-6 cm/s), indicating good intestinal absorption and putative brain penetration. LDT5 is not extensively protein-bound and is a substrate of human CYP2D6 and CYP2C19 but not of CYP3A4 (half-life >60 min), and did not significantly influence the activities of any of the human cytochrome P450 isoforms screened. LDT5 was considered safe albeit new studies are necessary to rule out putative central adverse effects through D2, 5-HT1A and 5-HT2B receptors, after chronic use. This work highlights the drug-likeness properties of LDT5 and supports its further preclinical development.

Rat vas deferens SERCA2 is modulated by Ca2+/calmodulin protein kinase II-mediated phosphorylation

Ca2+ pumps are important players in smooth muscle contraction. Nevertheless, little information is available about these pumps in the vas deferens. We have determined which subtype of sarco(endo)plasmic reticulum Ca2+-ATPase isoform (SERCA) is expressed in rat vas deferens (RVD) and its modulation by calmodulin (CaM)-dependent mechanisms. The thapsigargin-sensitive Ca2+-ATPase from a membrane fraction containing the highest SERCA levels in the RVD homogenate has the same molecular mass (∼115 kDa) as that of SERCA2 from the rat cerebellum. It has a very high affinity for Ca2+ (Ca0.5 = 780 nM) and a low sensitivity to vanadate (IC50 = 41 µM). These facts indicate that SERCA2 is present in the RVD. Immunoblotting for CaM and Ca2+/calmodulin-dependent protein kinase II (CaMKII) showed the expression of these two regulatory proteins. Ca2+ and CaM increased serine-phosphorylated residues of the 115-kDa protein, indicating the involvement of CaMKII in the regulatory phosphorylation of SERCA2. Phosphorylation is accompanied by an 8-fold increase of thapsigargin-sensitive Ca2+ accumulation in the lumen of vesicles derived from these membranes. These data establish that SERCA2 in the RVD is modulated by Ca2+ and CaM, possibly via CaMKII, in a process that results in stimulation of Ca2+ pumping activity.

Lack of evidence for regulation of cardiac P-type ATPases and MAP kinases in transgenic mice with cardiac-specific overexpression of constitutively active á1B-adrenoceptors

The regulatory function of á1B-adrenoceptors in mammalian heart homeostasis is controversial. The objective of the present study was to characterize the expression/activity of key proteins implicated in cardiac calcium handling (Na+/K+-ATPase and Ca2+-ATPases) and growth (ERK1/2, JNK1/2 and p38) in mice with cardiac-selective overexpression of constitutively active mutant á1B-adrenoceptor (CAMá1B-AR), which present a mild cardiac hypertrophy phenotype. Immunoblot assays showed that myocardial plasma membrane Ca2+-ATPase (PMCA) expression was increased by 30 percent in CAMá1B-AR mice (N = 6, P < 0.05), although there was no change in sarco/endoplasmic reticulum Ca2+-ATPase (SERCA2) expression. Moreover, total Ca2+-ATPase activity was not modified, but a significant increase in the activity of the thapsigargin-resistant (PMCA) to thapsigargin-sensitive (SERCA) ratio was detected. Neither Na+/K+-ATPase activity nor the expression of á1 and á2 subunit isoforms was changed in CAMá1B-AR mouse hearts. Moreover, immunoblot assays did not provide evidence for an enhanced activation of the three mitogen-activated protein kinases studied in this stage of hypertrophy. Therefore, these findings indicate that chronic cardiac á1B-AR activation in vivo led to mild hypertrophy devoid of significant signs of adaptive modifications concerning primary intracellular calcium control and growth-related proteins, suggesting a minor pathophysiological role of this adrenergic receptor in mouse heart at this stage of development.

Control of calcium homeostasis in Schistosoma mansoni

Calcium signalling is fundamental for muscular contractility of Schistosoma mansoni. We have previously described the presence of transport ATPases (Na+,K+-ATPase and (Ca2+-Mg2+)-ATPase) and calcium channels (ryanodine receptors - RyR) involved in control of calcium homeostasis in this worm. Here we briefly review the main technics (ATPase activity, binding with specific radioligands, fluxes of 45Ca2+ and whole worm contractions) and results obtained in order to compare the distribution patterns of these proteins: thapsigargin-sensitive (Ca2+-Mg2+)-ATPase activity and RyR co-purified in P1 and P4 fractions mainly, which is compatible with a sarcoplasmic reticulum localization, while basal ATPase (along with Na+,K+-ATPase) and thapsigargin-resistant (Ca2+-Mg2+)-ATPase have a distinct distribution, indicative of their plasma membrane localization. Finally we attempt to integrate these contributions with data from other groups in order to propose the first synoptic model for control of calcium homeostasis in S. mansoni

Selective destruction of nigrostriatal dopaminergic neurons does not alter [3H]-ryanodine binding in rat striatum

Dopamine nigrostriatal neurons are important for motor control and may contain a particularly dense population of ryanodine receptors involved in the control of dopamine release. To test this hypothesis, we used a classical model of unilateral selective lesion of these neurons in rats based on 6-hydroxydopamine (6-OHDA) injection into the substantia nigra. Binding of [3H]-GBR 12935, used as a presynaptic marker since it labels specifically the dopamine uptake complex, was dramatically decreased by 83-100 percent in striatum homogenates after 6-OHDA lesion. On the contrary, no reduction of [3H]-ryanodine binding was observed. The present data indicate that [3H]-ryanodine binding sites present in rat striatum are not preferentially localized in dopaminergic terminals

Portal veins of mice infected with Schistosoma mansoni exhibit an increased reactivity to 5-Hydroxytryptamine

In chronic severe infection with Schistosoma mansoni, portal hypertension and related vascular alterations usually develop as a consequence of granolomatous response to eggs. In order to investigate a putative direct effect of worms on the reactivity of their host portal vein, mice infected only with male worms were used in the present study. An higher reactivity to 5-hydroxytryptamine (5-HT) characterized by an increase in the maximal contraction and sensitivity was observed in portal vein from infected mice compared to healthy mice. Blockade of NO-synthase with l-NAME induced a small increase in 5-HT potency in portal vein from non-infected mice without changing the amplitude of the contractions, whereas it did not alter the reactivity of veins from infected mice. The present results show that unisexual infection of mice with male S. mansoni increased the reactivity of the portal vein to 5-HT which seems to be partially related to an alteration in the nitric oxide release by endothelium.

Decrease in the ratio of high to low affinity isozymes of (Na+ +K+)-ATPase during the development of rat cardiac ventricles

The ratio of (Na++K+)-ATPase (EC 3.6.1.3.) isoforms with high and low affinity for cardiac glycosides was studied in heart preparations from neonatal, 3-month and 6-month old Wistar rats. Biphasic ouabain inhibition curves of (Na++K+)-ATPase activity indicated that the relative contribution of the high-affinity process decreased from 34 percent at 9 days to 23 percent at 3 months and to 10 percent at 6 months. Scatchard plots for [3H]ouabain binding were curvillinear and indicated that the relative contribution of the high-affinity sites (Kd = 0.1-0.25 µM) decreased by about one-half between 3 months (19-24 percent, N = 2) and 6 months (9-11 percent, N = 2)

Gasimetría arterial en adultos jóvenes sanos en Bogotá

Se determinaron los gases arteriales en adultos jóvenes sanos, teniendo en cuenta todos los factores quelos afectan. Encontramos algunos valores diferentesa los hallados a nivel del mar, con una alcalosis respiratoria crónica relacionada con la altura. Los datos concuerdan con estudios anteriores, no obstante, se encontraron algunas variaciones en cuanto al pH, que consideramos, deben tenerse en cuenta en Santafé de Bogotá.

Praziquantel inhibits Schistosoma mansoni attachment in vitro

Male adult Schistosoma mansoni worms were placed in a glass dish containing Tyrode solution and observed for 15 min after addition of praziquantel (0.01 to 1 pmicron M). Praziquantel promoted a concentrationp- and time-dependent inhibition of sucker-mediated attachment of the worm. Attachment inhibition was correlated with shortening of the parasite. We propose that the rapid and total inhibition of worm attachment observed in vitro with 1 micronM praziquantel indicates that therapeutic concentrations of this drug should promote a rapid hepatic shift, in vivo, which may facilitate host tissue reaction

The use of a non-linear regression approach for the analysis of the ouabain-K+ interaction with (Na++K+)-ATPase from guinea pig and rat hearts

1. The interaction between ouabain and K+ and their effects (Na+ + K+)-ATPase activity were studied using microsomes from guinea pig and rat heart. 2. Microsomes were incubated in the presence of various concentrations of K+ and ouabain and ATPase activity was estimated by measuring the inorganic phosphate liberated. The experimental data were analyzed statistically by micro-computer, using a non-linear regressión program based on the steepest descent techinique. 3. The experimental data were best fitted by a model which assumes that ouabain acts like a mixed inhibitor with respect to the apparently cooperative K+ activation of (Na+ + K+)-ATPase. This quantitative approach provieded estimates (with approximate standard deviations) of al the parameters involved in the model. 4. The inhibition constant for the uncompetitive term of the effect was 7 - to 9 - fold higher than the inhibiton constant for the competitive term for both the guinea pig and rat heart preparations. 5. The present results indicate tahta graphical analyses are helpful for illustrative purposes but sugfgests that a computerized, non-linear regression program simultaneously analyzing all the non-linearized data shoul be used to quantify the complex kinetic parameters and to discriminate objectively among possible models

A Mg2+-independent Ca2+-stimulated ATPase activity in the tegument of Schistosoma mansoni

A tegumental fraction was prepared from Schistosoma mansoni. This fraction exhibited ATPase activity stimulated by Ca2+ in the absence of Mg2+. The Mg2+ independency was assessed by lowering contaminant Mg2+ using CDTA. The peak of activity was 220 micronmol Pi mg-1 protein h-1 and the K0.5 for CaATP was 0.32 mM; the same K0.5 was obtained using MgATP as substrate, in the absence of Ca2+. Both activities may be promoted by the same enzyme since the addition of Ca2+ did not increase the ATPase activity measured in the presence of a saturating MgATP concentration