The Use of a Variable Representing Compliance Improves Accuracy of Estimation of the Effect of Treatment Allocation Regardless of Discontinuation in Trials with Incomplete Follow-up

Abstract–In Clinical Trials, not all randomized patients follow the course of treatment they are allocated to. The potential impact of such deviations is increasingly recognized, and it has been one of the reasons for a redefinition of the targets of estimation (“Estimands”) in the ICH E9 draft Addendum. Among others, the effect of treatment assignment, regardless of the adherence, appears an Estimand of practical interest, in line with the intention-to-treat principle. This study aims at evaluating the performance of different estimation techniques in trials with incomplete post-discontinuation follow-up when a “treatment-policy” strategy is implemented. To achieve that, we have (i) modeled and visualized as directed acyclic diagram a reasonable data-generating model; (ii) investigated which set of variables allows identification and estimation of such effect; (iii) simulated 10,000 trials in Major Depressive Disorder, with varying real treatment effects, proportions of patients discontinuing the treatment, and incomplete follow-up. Our results suggest that, at least in a “Missing at Random” setting, all studied estimation methods increase their performance when a variable representing compliance is used. This effect is more pronounced the higher the proportion of post-discontinuation follow-up is

An Oral Recombinant Vaccine in Dogs against Echinococcus granulosus, the Causative Agent of Human Hydatid Disease: A Pilot Study

Dogs are the main source of human cystic echinococcosis. An oral vaccine would be an important contribution to control programs in endemic countries. We conducted two parallel experimental trials in Morocco and Tunisia of a new oral vaccine candidate against Echinococcus granulosus in 28 dogs. The vaccine was prepared using two recombinant proteins from adult worms, a tropomyosin (EgTrp) and a fibrillar protein similar to paramyosin (EgA31), cloned and expressed in a live attenuated strain of Salmonella enterica serovar typhimurium

Identification and Characterization of Paramyosin from Cyst Wall of Metacercariae Implicated Protective Efficacy against Clonorchis sinensis Infection

Human clonorchiasis has been increasingly prevalent in recent years and results in a threat to the public health in epidemic regions, motivating current strategies of vaccines to combat Clonorchis sinensis (C. sinensis). In this study, we identified C. sinensis paramyosin (CsPmy) from the cyst wall proteins of metacercariae by proteomic approaches and characterized the expressed recombinant pET-26b-CsPmy protein (101 kDa). Bioinformatics analysis indicated that full-length sequences of paramyosin are conserved in helminthes and numerous B-cell/T-cell epitopes were predicted in amino acid sequence of CsPmy. Western blot analysis showed that CsPmy was expressed at four life stages of C. sinensis, both cyst wall proteins and soluble tegumental components could be probed by anti-CsPmy serum. Moreover, immunolocalization results revealed that CsPmy was specifically localized at cyst wall and excretory bladder of metacercaria, as well as the tegument, oral sucker and vitellarium of adult worm. Both immunoblot and immunolocalization results demonstrated that CsPmy was highly expressed at the stage of adult worm, metacercariae and cercaria, which could be supported by real-time PCR analysis. Both recombinant protein and nucleic acid of CsPmy showed strong immunogenicity in rats and induced combined Th1/Th2 immune responses, which were reflected by continuous high level of antibody titers and increased level of IgG1/IgG2a subtypes in serum. In vaccine trials, comparing with control groups, both CsPmy protein and DNA vaccine exhibited protective effect with significant worm reduction rate of 54.3% (p<0.05) and 36.1% (p<0.05), respectively. In consistence with immune responses in sera, elevated level of cytokines IFN-γ and IL-4 in splenocytes suggested that CsPmy could induce combined cellular immunity and humoral immunity in host. Taken together, CsPmy could be a promising vaccine candidate in the prevention of C. sinensis regarding its high immunogenicity and surface localization

Single Dose Novel Salmonella Vaccine Enhances Resistance against Visceralizing L. major and L. donovani Infection in Susceptible BALB/c Mice

Visceral leishmaniasis is a major neglected tropical disease, with an estimated 500,000 new cases and more than 50,000 deaths attributable to this disease every year. Drug therapy is available but costly and resistance against several drug classes has evolved. Despite all efforts, no commercial, let alone affordable, vaccine is available to date. Thus, the development of cost effective, needle-independent vaccines is a high priority. Here, we have continued efforts to develop live vaccine carriers based on recombinant Salmonella. We used an in silico approach to select novel Leishmania parasite antigens from proteomic data sets, with selection criteria based on protein abundance, conservation across Leishmania species and low homology to host species. Five chosen antigens were differentially expressed on the surface or in the cytosol of Salmonella typhimurium SL3261. A two-step procedure was developed to select optimal Salmonella vaccine strains for each antigen, based on bacterial fitness and antigen expression levels. We show that vaccine strains of Salmonella expressing the novel Leishmania antigens LinJ08.1190 and LinJ23.0410 significantly reduced visceralisation of L. major and enhanced systemic resistance against L. donovani in susceptible BALB/c mice. The results show that Salmonella are valid vaccine carriers for inducing resistance against visceral leishmaniasis but that their use may not be suitable for all antigens

Helminthes du Renard commun

Soixante-neuf renards sauvages capturés en Auvergne de janvier 1977 à janvier 1978 présentent des helminthes intestinaux dans la proportion de 76,8 %. 59,4 % hébergent des Cestodes, 72,4 % des Nématodes et aucun des Trématodes. La liste des espèces identifiées est la suivante : 1° Cestodes. A) Formes adultes fertiles de Mesocestoides litteratus chez 27,5 % des hôtes ; de Taenia crassiceps (15,9 %) ; de Taenia polyacantha (27,5 %) ; de Echinococcus multilocularis (7,2 %) ; de Anomotaenia paradoxa (4,34 %). B) Formes immatures de Taenia pisiformis (2,89 %) ; de T. ovis (1,44 %) et d’un Cestode sp. (1,44 %). 2° Nématodes. Uncinaria stenocephala chez 68,1 % des hôtes ; Ancylostoma caninum (1,4 %) ; Molineus patens (1,4 %) ; Oxyuridé sp. (1,44 %) ; Toxocara canis (27,5 %) ; Toxascaris leonina (33,3 %). Les espèces d’helminthes identifiées dans le centre de la France ne se différencient pas des espèces signalées en Europe chez le même hôte, à l’exception de A. paradoxa, Dilépididé d’Oiseau, tout à fait inhabituel chez un Carnivore

Phenylalanine derivatives active against

The action of phenylalanine derivatives against a cyst forming strain of Toxoplasma gondii was tested in vitroand in vivo in mice. These compounds were Phe-Phe-OMe (dipeptide methyl ester) 1 and its cyclized product, 3,6-dibenzyl-2,5-dioxopiperazine 2, Boc-L-Phe 3, L-Phe-OMe 4, Boc-L-Phe-L-Phe-OMe 5. After a 48 hr incubation in vitro, the compounds 3 and 5 induced a higher inhibition than the control molecule, pyrimethamine. In the in vivo studies, the compound 3 induced a 77 % decrease in the number of cerebral cysts, comparable to pyrimethamine. Compounds 1, 5 and 4 induced a decrease of about 63 % in the cyst number. A size reduction and an alteration of the wall of treated cysts were often noted. In a histological study, a reduction in cyst size without either inflammation or intervention of the nevroglial cells was observed. The present study provides evidence on the efficacy of phenylalanine derivatives and especially Boc-Phe 3, against T. gondii brain cysts in mice

Biochimie du liquide hydatique

Onze métabolites ont été dosés dans le liquide hydatique de 19 kystes humains ainsi que dans le plasma des patients avant l’intervention chirurgicale. Le dosage des anticorps spécifiques, associés à chacun de ces kystes de localisation et de taille variables, a été assuré par immunofluorescence indirecte sur coupe en congélation de protoscolex. Les résultats montrent que le sodium (132 ± 5,2 mmol/1), le chlore (92,9 ± 6,5 mmol/1) et les bicarbonates (22,1 ± 1,5 mmol/1) représentent les 3 ions principaux et qu’ils sont en équiconcentration avec le plasma. Le potassium (5,4 ± 0,3 mmol/1) et le calcium (4,7 ± 0,9 mmol/1) sont plus concentrés qu’au niveau plasmatique. Le phosphore (0,1 ± 0,03 mmol/1) l’est 10 fois moins. Le glucose (3,4 ± 0,8 mmol/1), la créatinine (39,3 ± 7,2 µmol/l) et l’urée (4,6 ± 0,8 mmol/1) subissent des variations importantes. Le cholestérol (0,06 ± 0,03 mmol/1) est environ 100 fois moins concentré qu’au niveau plasmatique. Les protéines totales (0,34 ± 0,09 g/l) sont en très faible quantité. Les kystes extra-pulmonaires sont associés aux réponses immunes les plus fortes, et aucune corrélation n’est observée entre la taille des kystes et l’intensité des réponses immunes associées.Une différence significative des concentrations relatives en cholestérol (concentration kystique / concentration plasmatique) est observée entre les kystes pulmonaires et extra-pulmonaires (respectivement 0,0048 ± 0,0032 et 0,018 ± 0,01 — p < 0.05). Ces derniers sont environ 4 fois plus riches en cholestérol. La taille des kystes et l’intensité des réponses immunes associées n’ont pas d’influence sur ce phénomène. L’hypothèse d’une perméabilité plus importante des kystes extra-pulmonaires est avancée