93 research outputs found
Identification and Validation of Carbonic Anhydrase II as the First Target of the Anti-Inflammatory Drug Actarit.
Background and purpose: Identifying the macromolecular targets of drug molecules is a fundamental aspect of drug discovery and pharmacology. Several drugs remain without known targets (orphan) despite large-scale in silico and in vitro target prediction efforts. Ligand-centric chemical-similarity-based methods for in silico target prediction have been found to be particularly powerful, but the question remains of whether they are able to discover targets for target-orphan drugs. Experimental Approach: We used one of these in silico methods to carry out a target prediction analysis for two orphan drugs: actarit and malotilate. The top target predicted for each drug was carbonic anhydrase II (CAII). Each drug was therefore quantitatively evaluated for CAII inhibition to validate these two prospective predictions. Key Results: Actarit showed in vitro concentration-dependent inhibition of CAII activity with submicromolar potency (IC50 = 422 nM) whilst no consistent inhibition was observed for malotilate. Among the other 25 targets predicted for actarit, RORγ (RAR-related orphan receptor-gamma) is promising in that it is strongly related to actarit's indication, rheumatoid arthritis (RA). Conclusion and Implications: This study is a proof-of-concept of the utility of MolTarPred for the fast and cost-effective identification of targets of orphan drugs. Furthermore, the mechanism of action of actarit as an anti-RA agent can now be re-examined from a CAII-inhibitor perspective, given existing relationships between this target and RA. Moreover, the confirmed CAII-actarit association supports investigating the repositioning of actarit on other CAII-linked indications (e.g., hypertension, epilepsy, migraine, anemia and bone, eye and cardiac disorders)
Performance of machine-learning scoring functions in structure-based virtual screening
Classical scoring functions have reached a plateau in their performance in virtual screening and binding affinity prediction. Recently, machine-learning scoring functions trained on protein-ligand complexes have shown great promise in small tailored studies. They have also raised controversy, specifically concerning model overfitting and applicability to novel targets. Here we provide a new ready-to-use scoring function (RF-Score-VS) trained on 15 426 active and 893 897 inactive molecules docked to a set of 102 targets. We use the full DUD-E data sets along with three docking tools, five classical and three machine-learning scoring functions for model building and performance assessment. Our results show RF-Score-VS can substantially improve virtual screening performance: RF-Score-VS top 1% provides 55.6% hit rate, whereas that of Vina only 16.2% (for smaller percent the difference is even more encouraging: RF-Score-VS top 0.1% achieves 88.6% hit rate for 27.5% using Vina). In addition, RF-Score-VS provides much better prediction of measured binding affinity than Vina (Pearson correlation of 0.56 and -0.18, respectively). Lastly, we test RF-Score-VS on an independent test set from the DEKOIS benchmark and observed comparable results. We provide full data sets to facilitate further research in this area (http://github.com/oddt/rfscorevs) as well as ready-to-use RF-Score-VS (http://github.com/oddt/rfscorevs_binary)
Osteolisis tibial secundaria a un implante ligamentoso de Leeds-Keio: Presentación de un caso
Hasta hace algunos años, el ligamento artificial de Leeds-Keio, se usó en muchos casos para la reconstrucción de lesiones del ligamento cruzado anterior. Hoy día no se usa para este tipo de lesiones debido a los pobres resultados que se observaron a medio y largo plazo. No obstante, su uso está indicado en otras lesiones, como son la reconstrucción del aparato extensor de la rodilla, y en inestabilidades del hombro y de la columna vertebral. Presentamos un caso de osteolisis masiva del platillo tibial que requirió la retirada del implante seguida de autoinjerto óseo, complicación que no ha sido comunicada anteriormenteSome years ago the Leed-Keio prosthesis was widely used for anterior cruciate ligament repair. Due to the poor middle and long-term results, this technique has been abandoned. However, synthetic implants are used for other lesions such as knee extensor mechanism rupture and shoulder or lumbar spine instabilities. This paper presents a case of massive osteolysis of the tibial plateau requiring removal of the prosthesis and autologous bone graft, a complication not reported before
Machine Learning Prediction of Cancer Cell Sensitivity to Drugs Based on Genomic and Chemical Properties
Predicting the response of a specific cancer to a therapy is a major goal in modern oncology that should ultimately lead to a personalised treatment. High-throughput screenings of potentially active compounds against a panel of genomically heterogeneous cancer cell lines have unveiled multiple relationships between genomic alterations and drug responses. Various computational approaches have been proposed to predict sensitivity based on genomic features, while others have used the chemical properties of the drugs to ascertain their effect. In an effort to integrate these complementary approaches, we developed machine learning models to predict the response of cancer cell lines to drug treatment, quantified through IC50 values, based on both the genomic features of the cell lines and the chemical properties of the considered drugs. Models predicted IC50 values in a 8-fold cross-validation and an independent blind test with coefficient of determination R2 of 0.72 and 0.64 respectively. Furthermore, models were able to predict with comparable accuracy (R2 of 0.61) IC50s of cell lines from a tissue not used in the training stage. Our in silico models can be used to optimise the experimental design of drug-cell screenings by estimating a large proportion of missing IC50 values rather than experimentally measuring them. The implications of our results go beyond virtual drug screening design: potentially thousands of drugs could be probed in silico to systematically test their potential efficacy as anti-tumour agents based on their structure, thus providing a computational framework to identify new drug repositioning opportunities as well as ultimately be useful for personalized medicine by linking the genomic traits of patients to drug sensitivity
An adaptive phase II/III safety and efficacy randomized controlled trial of single day or three-day fixed-dose albendazole-ivermectin co-formulation versus albendazole for the treatment of Trichuris trichiura and other STH infections. ALIVE trial protocol
Background: Soil-transmitted helminths (STH) are targeted for control through mass drug-administration campaigns to prevent morbidity affecting at-risk groups in endemic regions. Although broadly successful, the use of albendazole and mebendazole achieved variable progress, with deficiencies against Trichuris trichiura and a predictable low efficacy against Strongyloides stercoralis. Novel drug combinations offer a potential solution, providing they can be delivered safely and maintain efficacy against all STH species. Here we present the protocol of a clinical trial to evaluate a fixed-dose combination (FDC) tablet containing albendazole and ivermectin that will be compared against albendazole against STH. Methods: An adaptive phase II/III randomized controlled trial will be undertaken in STH endemic sites in Ethiopia, Kenya and Mozambique to evaluate an oral FDC of 400 mg albendazole and either 9- or 18 mg ivermectin. FDC will be administered as a single dose or single doses over three-consecutive days and assessed against a single dose of 400 mg albendazole. In the phase II trial, 126 T. trichiura-infected children weighting 15 to 45 kg will be treated in a dose-escalation manner to determine safety objectives. In the phase III trial, 1097 participants aged 5 to 18 years old infected with T. trichiura, hookworm and S. stercoralis will be recruited to determine safety and efficacy. The trial will be open-label with blinded outcome assessors. Cure rate measured 21-days after-treatment in duplicate Kato-Katz is the primary efficacy outcome. Secondary objectives include efficacy evaluation by quantitative polymerase chain reaction (PCR) as an outcome measurement, description of pharmacokinetic parameters, palatability and acceptability evaluations, and monitoring of anthelmintic resistance. Conclusions: This trial with registrational goals seeks to evaluate an innovative fixed-dose combination of albendazole and ivermectin co-formulated tablets, with the goal of providing an anthelmintic regimen with improved efficacy and spectrum of coverage against STH. ClinicalTrials.gov registration: NCT05124691 (18/11/2021)
Direct venous inoculation of Plasmodium falciparum sporozoites for controlled human malaria infection: a dose-finding trial in two centres
BACKGROUND: Controlled human malaria infection (CHMI)
accelerates development of anti-malarial interventions. So far,
CHMI is done by exposure of volunteers to bites of five
mosquitoes carrying Plasmodium falciparum sporozoites (PfSPZ), a
technique available in only a few centres worldwide.
Mosquito-mediated CHMI is logistically complex, exact PfSPZ
dosage is impossible and live mosquito-based interventions are
not suitable for further clinical development. METHODS: An
open-labelled, randomized, dose-finding study in 18-45 year old,
healthy, malaria-naive volunteers was performed to assess if
intravenous (IV) injection of 50 to 3,200 aseptic, purified,
cryopreserved PfSPZ is safe and achieves infection kinetics
comparable to published data of mosquito-mediated CHMI. An
independent study site verified the fully infectious dose using
direct venous inoculation of PfSPZ. Parasite kinetics were
assessed by thick blood smear microscopy and quantitative real
time PCR. RESULTS: IV inoculation with 50, 200, 800, or 3,200
PfSPZ led to parasitaemia in 1/3, 1/3, 7/9, and 9/9 volunteers,
respectively. The geometric mean pre-patent period (GMPPP) was
11.2 days (range 10.5-12.5) in the 3,200 PfSPZ IV group.
Subsequently, six volunteers received 3,200 PfSPZ by direct
venous inoculation at an independent investigational site. All
six developed parasitaemia (GMPPP: 11.4 days, range: 10.4-12.3).
Inoculation of PfSPZ was safe. Infection rate and pre-patent
period depended on dose, and injection of 3,200 PfSPZ led to a
GMPPP similar to CHMI with five PfSPZ-infected mosquitoes. The
infectious dose of PfSPZ predicted dosage of
radiation-attenuated PfSPZ required for successful vaccination.
CONCLUSIONS: IV inoculation of PfSPZ is safe, well tolerated and
highly reproducible. It shall further accelerate development of
anti-malarial interventions through standardization and
facilitation of CHMI. Beyond this, rational dose selection for
whole PfSPZ-based immunization and complex study designs are now
possible. TRIAL REGISTRATION: ClinicalTrials.gov NCT01624961 and
NCT01771848
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