RESUMEN
Giardia intestinalis is an intestinal parasite that causes diarrhea in humans and animals worldwide. The enolase of G. intestinalis (GiENO) participates in its glycolysis pathway and is abundantly expressed in the parasite cytosol; however, its localization on the surface of trophozoites and cysts has been demonstrated. Enolases from bacteria and parasites can have different functions and are considered moonlighting proteins, for example, as a cell surface plasminogen receptor. In relation to GiENO, no studies have been performed about its possible participation as a plasminogen receptor. In this work, we employed molecular docking and multiscale molecular dynamics (MD) simulations to explore the possible interactions of human plasminogen (HsPLG) with the open and closed GiENO conformations. Our proposed GiENO plasminogen binding site (PLGBs) was identified at Lys266 based on the sequence comparison with bacterial enolase known to act as a plasminogen receptor. Our docking results performed with multiple MD snapshots of the closed GiENO conformation showed that Lys266 preferentially binds to the K5 domain of HsPLG. On the other hand, open GiENO conformations from all-atom and coarse-grained simulations indicated a high preference of the HsPLG K4 domain for lysine residues 186 and 188. Furthermore, we identified a potential N-glycosylation site of GiENO which suggests a possible explanation for the parasite cell surface localization or host mucin oligosaccharide adhesion mechanism. Our study constitutes the first multiscale computational study to explore the plasminogen receptor function of GiENO for its further consideration as a potential therapeutic target for giardiasis treatment.
Asunto(s)
Giardia lamblia/enzimología , Fosfopiruvato Hidratasa/metabolismo , Plasminógeno/metabolismo , Proteínas Protozoarias/metabolismo , Citosol/metabolismo , Giardia lamblia/metabolismo , Humanos , Simulación de Dinámica MolecularRESUMEN
The physicochemical properties, pK(a), Log P and solubility of compound alpha, (5-chloro-2-(methylthio)-6-(1-naphthyloxy)-1H-benzimidazole), a new fasciolicide agent, were characterized using conventional methods. Also, its pharmacokinetics was evaluated in sheep and cattle. In both species an oral dose of 12 mg/kg was administered. Blood samples were collected during 144 h and analyzed by using an HPLC assay. Results showed that compound alpha is a weak base with a pK(a) value of 2.87 and log P of 1.44. The solubility was very low in aqueous solvents. Pharmacokinetic studies showed that in both species compound alpha could not be detected at any sampling time. The mean half-life (t(1/2)) values of alpha sulphoxide in sheep and cattle were 19.86 and 29.87 h, while the half-life values of alpha sulphone were 19.43 and 46.32 h respectively. C(max) values of alpha sulphoxide did not differ between species while alpha sulphone values were higher in cattle. Plasma protein binding of alpha sulphoxide was between 82% and 86%. These results, combined with the previous efficacy studies, suggest that compound alpha could be a promising fasciolicide agent.
Asunto(s)
Antiplatelmínticos/farmacocinética , Bovinos/metabolismo , Imidazoles/farmacocinética , Naftalenos/farmacocinética , Ovinos/metabolismo , Animales , Antiplatelmínticos/sangre , Antiplatelmínticos/farmacología , Bovinos/sangre , Cromatografía Líquida de Alta Presión/veterinaria , Fasciolidae/efectos de los fármacos , Femenino , Semivida , Imidazoles/sangre , Imidazoles/farmacología , Masculino , Naftalenos/sangre , Naftalenos/farmacología , Óxidos/farmacología , Ovinos/sangre , Compuestos de Azufre/farmacología , Dióxido de Azufre/farmacologíaRESUMEN
Comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) were performed on a set of pyridinone derivatives. A molecular alignment obtained by docking of compounds into the non-nucleoside reverse transcriptase inhibitor binding site of HIV-1 was used. Good correlations between the calculated binding free energies and experimental inhibitory activities suggest that the binding conformations of these inhibitors are reasonable. Robust and predictive 3D-QSAR models were obtained with q2 values of 0.706 and 0.723 for CoMFA and CoMSIA, respectively. The models were validated by an external test set obtaining r2 pred values of 0.720 and 0.750 for CoMFA and CoMSIA, respectively. The CoMFA, CoMSIA and docking results help to understand the type of interactions that occur between pyridinone derivatives with the non-nucleoside reverse transcriptase inhibitor binding pocket, and explain the viral resistance to pyridinone derivatives upon mutation of amino acids Tyr181 and Tyr188. The results obtained provide information for a better understanding of the drug resistant mechanisms. The 3D-QSAR models derived will be used to guide the design of pyridinone derivatives active against mutant strains of reverse transcriptase.
Asunto(s)
Piridonas/química , Inhibidores de la Transcriptasa Inversa/química , Simulación por Computador , Ligandos , Modelos Moleculares , Nevirapina/química , Piridonas/metabolismo , Programas InformáticosRESUMEN
The efficacy of 5-chloro-2-methylthio-6-(1-naphthyloxy)- 1H-benzimidazole, called "alpha", was tested against Fasciola hepatica. Fluke-free calves ( n=32) were divided into 8 groups and infected with 150 metacercariae per animal. All animals subsequently received a second infection with another 150 metacercariae, given at different time intervals aimed to produce flukes of differing ages within the experimental animals. When the flukes reached the required age in the animals, four groups were treated with a single oral dose of 12 mg/kg of compound alpha and the remaining ones served as non-treated controls. Two weeks after treatment the animals of all groups were sacrificed and the livers were removed to determine the numbers of parasites present in the treated and untreated controls. In the treated groups the fluke reduction for the 3 day/2 week group was 100%, for the 3 week/4 week group it was 96.4%, for the 6 week/8 week group it was 99.2% and for the 10 week/12 week group it was 100%.
Asunto(s)
Antihelmínticos/uso terapéutico , Fasciola hepatica/patogenicidad , Fascioliasis/tratamiento farmacológico , Animales , Bencimidazoles/uso terapéutico , Bovinos , Modelos Animales de Enfermedad , Ensayo de Inmunoadsorción Enzimática , Fasciola hepatica/crecimiento & desarrolloRESUMEN
The efficacy of 5-chloro-2-methylthio-6-(1-napthyloxy)-1H-benzimidazole was evaluated with three commercial fasciolicides in terms of the percentage of egg reduction in cattle. Fifty Swiss cows were selected for inclusion in the trial based on finding eggs of Fasciola hepatica in their feces. On day 0, they were blocked in five groups (G) of ten animals each according to fecal egg counts. G1 received compound alpha at 12 mg/kg p.o.; G2 triclabendazole at 12 mg/kg p.o.; G3.closantel at 3.5 mg/kg s.c.; G4 clorsulon at 2.0 mg/kg s.c. G5 animals served as untreated controls. Fecal analysis was performed on days 0, 7, 14, 21, 28, 60 and 90. Efficacy was measured on days 14 and 21. In addition, the extension and intensity effects were determined on day 60. The percentage efficacy for groups 1-4 was 98.1, 98.7, 98.2 and 97.9 on day 14 and 98.5, 97.9, 97.7 and 97.9 on day 21, respectively. No statistical differences were observed between treated groups.
Asunto(s)
Antihelmínticos/uso terapéutico , Bencimidazoles/uso terapéutico , Enfermedades de los Bovinos/tratamiento farmacológico , Fascioliasis/veterinaria , Animales , Bovinos , Fasciola hepatica , Fascioliasis/tratamiento farmacológico , Heces/parasitología , Recuento de Huevos de Parásitos , Salicilanilidas/uso terapéutico , Sulfanilamidas/uso terapéutico , Resultado del Tratamiento , TriclabendazolRESUMEN
Three N-acyl (2, 3, and 4), two N-alkoxycarbonyl (5 and 6), and one N-acyloxymethyl (7) derivatives of albendazole (1) have been prepared and assessed as potential prodrugs. The determination of the aqueous solubility and partition coefficient, as well as the conversion of these derivatives to 1 in buffer solution, human plasma, and pig liver esterase were determined.
Asunto(s)
Albendazol/síntesis química , Antihelmínticos/síntesis química , Profármacos/síntesis química , Albendazol/química , Albendazol/farmacología , Antihelmínticos/química , Antihelmínticos/farmacología , Estabilidad de Medicamentos , Concentración de Iones de Hidrógeno , Hidrólisis , Profármacos/química , Profármacos/farmacología , Solubilidad , Agua/químicaRESUMEN
The advantages of cultivating human pre-embryos to the stage of blastocites, are well known. The use of media of culture sequential, without the backing of somatic cells, is new. The objective was to cultivate human pre-embryos to the stage of blastocyte to the determine the recuperation indexes, implantation index and pregnancy index in patients subjected to FIVT/TE or ICSI. Once obtained the ovules of patients were injected/inseminated to latter be cultivated for 72 hours using P1 medium at 10% of SSS under mineral oil for, latter, be transferred to a complex medium for blastocites culture for 48 hours, and finally be transferred. Thirteen were included (9 of FIV and 4 of ICSI) obtaining 205 ovules; fertilized 143 and 131 had cellular division. One hundred and twenty one pre-embryos were cultivated to blastocyst stage, from which, 53 reached that stage (43.8%); transferring 28 and freezing 25. In average, 2.1 blastocysts were transferred by patient. There were four pregnancies and one alive newborn, at term for an index of implantation of 14.2% and a pregnancy index of 30.7%. The study shows our initial experience, which demonstrated and acceptable idea of recuperation of blastocysts and pregnancies.
Asunto(s)
Blastocisto , Transferencia de Embrión , Fertilización In Vitro , Medios de Cultivo , Técnicas de Cultivo , Femenino , Humanos , Recién Nacido , Estudios Longitudinales , Embarazo , Estudios Prospectivos , Inyecciones de Esperma Intracitoplasmáticas , Factores de TiempoRESUMEN
BACKGROUND: Two albendazole (ABZ) prodrugs, N-methoxycarbonyl-N'-[(2-nitro-4-propylthio) phenyl] thiourea (compound 2), and N-methoxycarbonyl-N'-[(2-nitro-5-propylthio) phenyl] thiourea (compound 3) have recently been synthesized. These compounds showed greater solubility than ABZ itself. METHODS: In order to evaluate the biotransformation of compounds 2 and 3 to ABZ and/or ABZ-sulphoxide (ABZ-SO), plasma samples taken from mice treated with the prodrugs were analyzed by HPLC. Also, the anthelmintic activity of compounds 2 and 3 against Trichinella spiralis was evaluated in the mice experimentally infected with the parasite. RESULTS: The presence of ABZ and/or ABZ-SO was demonstrated in plasma samples taken at different time intervals after prodrug administration, although their levels were low compared to those reached in mice treated with ABZ. Additionally, prodrugs 2 and 3 were also detected in these samples. In regard to the anthelmintic activity of ABZ prodrugs, it was shown that compound 3 was more active than compound 2. Additionally, it was as effective as ABZ against T. spiralis pre-adult, adult, and female fecundity. However, compound 3 was not as active as ABZ against the muscle stage of the parasite. CONCLUSIONS: Compound 3 had better anthelmintic activity against T. spiralis than compound 2. The bioconversion of compounds 2 and 3 to ABZ and/or ABZ-SO was demonstrated by HPLC, but they did not reach equivalent concentrations to that of ABZ. Prodrugs 2 and 3 were also present in plasma samples, suggesting that prodrugs were not efficiently reduced in the intestine of mice.
Asunto(s)
Albendazol/uso terapéutico , Antihelmínticos/uso terapéutico , Triquinelosis/tratamiento farmacológico , Animales , Evaluación Preclínica de Medicamentos , Femenino , Masculino , Ratones , Ratones Endogámicos BALB C , Ratas , Ratas Sprague-DawleyRESUMEN
We present 84 pregnancies (3 twin pregnancies) of 80 women with Systemic Lupus Erythematosus. Although there was a multidisciplinary prenatal control, in 83% of the cases there were one or more complications during pregnancy, most of them being preterm labor, premature rupture of membranes and preeclampsia-eclampsia. There were flares up in 15 of 84 cases, (17.85%). Worsening of renal function was the most common finding. There were 9 abortions, 3 stillbirths, 1 neonatal death and two newborns with congenital heart block. No maternal deaths were present.
Asunto(s)
Lupus Eritematoso Sistémico , Complicaciones del Embarazo , Aborto Espontáneo/etiología , Adulto , Eclampsia/etiología , Femenino , Muerte Fetal/etiología , Rotura Prematura de Membranas Fetales/etiología , Bloqueo Cardíaco/etiología , Humanos , Recién Nacido , Lupus Eritematoso Sistémico/complicaciones , Trabajo de Parto Prematuro/etiología , Paridad , Preeclampsia/etiología , Embarazo , Embarazo Múltiple , Diagnóstico PrenatalRESUMEN
The aim of the present study was to evaluate the flukicide efficacy of the 2-amino-5(6)-chloro-1-methoxycarbonylbenzimidazole (II), named Fasciolinip-1, against eight and twelve-week old flukes in sheep. In a first experiment 35 young sheep were infected each with 300 metacercariae of Fasciola hepatica. Eight weeks postinfection five groups of seven animals each were treated as follows: Groups 1, 2 and 3 were given 2.5, 5 and 10 mg/kg of Fasciolinip-1. Groups 4 and 5 remained as non-treated and vehicle controls, respectively. In a second study, 32 sheep were infected each with 150 metacercariae. Twelve weeks postinfection, the animals were divided into 4 groups of 8 sheep each. Groups 1, 2 and 3 were treated orally with 5, 10 and 15 mg/kg of Fasciolinip-1, respectively. Group 4 remained as non-treated control. Fifteen days after treatment, all sheep from both experiments were killed to collect the flukes present in liver. Results indicated efficacies of 19.1%, 49.6% and 65.2% for groups 1, 2 and 3 of the first study and 48.3%, 64.8 and 90.6% for sheep of the second experiment, respectively. It was concluded that Fasciolinip-1 removed 8-week old flukes in limited numbers and 12-week old flukes in 90.6% when used at 15 mg/kg body weight.