RESUMO
The objective of this review is to better understand the concept of investigator-initiated trials and its benefits. While investigator-initiated trials can be an invaluable tool, there are several challenges in its initiation and management. However, it is for these reasons that Clinical Research Centre (CRC) had developed the Investigator Initiated Trial (IIT) Programme where financial support and technical assistance are provided to local investigators embarking on their own clinical trials. In the course of preparing the review, we found that the inclination of investigator-initiated trials has yet to be well established in Ministry of Health, Malaysia. Given the potential and impact of such trials, clinicians should be aware of their ability as well as the availability of a supportive network in mobilising their concerted research efforts. Greater research collaboration among investigators could foster more innovative, insightful and constructive research.
Assuntos
Ensaios Clínicos como Assunto , Órgãos Governamentais , Ensaios Clínicos como Assunto/estatística & dados numéricos , Humanos , Malásia , Projetos de PesquisaRESUMO
In this study we compared the effects of PCB126 and PCB153 on adult rat testicular androgenesis and the status of antioxidant enzymes in the interstitial cell compartment 96h after local intratesticular application. Obtained results indicated PCB126-induced inhibition of conversion of progesterone (P) and Δ(4)-androstenedione (A(4)) to testosterone (T), and stimulation of conversion of P to T induced by PCB153, while combined application had no effect. Activities of antioxidant enzymes were unchanged, except of decreased activity of SOD in PCB126-treated group. In parallel experiments, adult purified Leydig cells challenged with PCB congeners were incubated for 2h in the presence of corresponding steroid substrates. Results demonstrated that in the presence of subsaturating substrate concentrations PCB126 induced inhibition of conversion of P and A(4) to T at nM to µM doses, while PCB153 caused stimulation at nM concentrations. Further studies should indicate possible mechanism(s) of modulation of androgenesis by tested PCB congeners.