949 resultados para CLINICAL-TRIALS
Resumo:
BACKGROUND Antiretroviral treatment (ART) in children has special features and consequently, results obtained from clinical trials with antiretroviral drugs in adults may not be representative of children. Nelfinavir (NFV) is an HIV-1 Protease Inhibitor (PI) which has become as one of the first choices of PI for ART in children. We studied during a 3-year follow-up period the effects of highly active antiretroviral therapy with nelfinavir in vertically HIV-1 infected children. METHODS Forty-two vertically HIV-infected children on HAART with NFV were involved in a multicentre prospective study. The children were monitored at least every 3 months with physical examinations, and blood sample collection to measure viral load (VL) and CD4+ cell count. We performed a logistic regression analysis to determinate the odds ratio of baseline characteristics on therapeutic failure. RESULTS Very important increase in CD4+ was observed and VL decreased quickly and it remained low during the follow-up study. Children with CD4+ <25% at baseline achieved CD4+ >25% at 9 months of follow-up. HIV-infected children who achieved undetectable viral load (uVL) were less than 40% in each visit during follow-up. Nevertheless, HIV-infected children with VL >5000 copies/ml were less than 50% during the follow-up study. Only baseline VL was an important factor to predict VL control during follow-up. Virological failure at defined end-point was confirmed in 30/42 patients. Along the whole of follow-up, 16/42 children stopped HAART with NFV. Baseline characteristics were not associated with therapeutic change. CONCLUSION NFV is a safe drug with a good profile and able to achieve an adequate response in children.
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Metabolic problems lead to numerous failures during clinical trials, and much effort is now devoted to developing in silico models predicting metabolic stability and metabolites. Such models are well known for cytochromes P450 and some transferases, whereas less has been done to predict the activity of human hydrolases. The present study was undertaken to develop a computational approach able to predict the hydrolysis of novel esters by human carboxylesterase hCES2. The study involved first a homology modeling of the hCES2 protein based on the model of hCES1 since the two proteins share a high degree of homology (congruent with 73%). A set of 40 known substrates of hCES2 was taken from the literature; the ligands were docked in both their neutral and ionized forms using GriDock, a parallel tool based on the AutoDock4.0 engine which can perform efficient and easy virtual screening analyses of large molecular databases exploiting multi-core architectures. Useful statistical models (e.g., r (2) = 0.91 for substrates in their unprotonated state) were calculated by correlating experimental pK(m) values with distance between the carbon atom of the substrate's ester group and the hydroxy function of Ser228. Additional parameters in the equations accounted for hydrophobic and electrostatic interactions between substrates and contributing residues. The negatively charged residues in the hCES2 cavity explained the preference of the enzyme for neutral substrates and, more generally, suggested that ligands which interact too strongly by ionic bonds (e.g., ACE inhibitors) cannot be good CES2 substrates because they are trapped in the cavity in unproductive modes and behave as inhibitors. The effects of protonation on substrate recognition and the contrasting behavior of substrates and products were finally investigated by MD simulations of some CES2 complexes.
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Use of n-3 fatty acids (FA) has been reported to be beneficial for cancer patients. We performed a systematic review of the literature in order to issue recommendations on the clinical use of n-3 FA in the cancer setting. A systematic search was performed in MEDLINE, EMBASE, Cochrane and Healthstar databases. We selected clinical trials or prospective observational studies including patients with cancer and life expectancy >2 months, in which enteral supplements with n-3 FA were administered. Parameters evaluated individually were clinical (nutritional status, tolerance, survival and hospital stays), biochemical (inflammatory mediators), and functional (functional status, appetite and quality of life (QoL)). Seventeen studies met the inclusion criteria; eight were of high quality. The panel of experts established the following evidence: (1) oral supplements with n-3 FA benefit patients with advanced cancer and weight loss, and are indicated in tumours of the upper digestive tract and pancreas; (2) the advantages observed were: increased weight and appetite, improved QoL, and reduced post-surgical morbidity; (3) there is no defined pattern for combining different n-3 FA, and it is recommended to administer > 1.5 g/day; and (4) better tolerance is obtained administering low-fat formulas for a period of at least 8 weeks. All the evidences were grade B but for 'length of treatment' and 'advantage of survival' it was grade C. Our findings suggest that administration of n-3 FA (EPA and DHA) in doses of at least 1.5 g/day for a prolonged period of time to patients with advanced cancer is associated with an improvement in clinical, biological and QoL parameters.
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Une méta-analyse concernant l'utilisation de la rosiglitazone chez les diabétiques de type 2 a révélé une augmentation significative du risque d'infarctus du myocarde et une tendance à la surmortalité cardiovasculaire. La méthodologie de cette étude ainsi que ses conclusions ont été beaucoup critiquées. Cette étude montre les limites des méta-analyses auxquelles on prête un rang manifestement trop élevé dans la hiérarchie des niveaux de preuve. L'étude 4T a évalué trois schémas d'insuline dans le traitement du diabète de type 2. Les résultats à un an montrent que seule une minorité des patients atteignent les objectifs. Post-Steno 2 a été présenté au congrès européen du diabète. Ces nouvelles données confirment que le traitement intensifié de tous les facteurs de risque cardiovasculaire permet une réduction majeure de la mortalité cardiovasculaire après 13,3 ans. A recent meta-analysis on the rosiglitazone in the treatment of type 2 diabetes revealed a significant increased risk of myocardial infarction and a trend to a higher cardiovascular mortality. In the following month after this publication, the methodology as its conclusions were criticized. This study shows the limits of the meta-analyses to which one lends a row obviously too high in the hierarchy of the levels of evidence. The study 4T evaluated 3 insulin strategies in the treatment of the type 2 diabetes. The results at one year show that only a minority of the patients achieve the goals. Post-Steno 2 was presented at the European congress diabetes. These new data confirm that the intensified treatment of all cardiovascular factors risk allows a major reduction of cardiovascular mortality after 13.3 years
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BACKGROUND: European Medicines Agency guidelines recognize two different treatment goals for alcohol dependence: abstinence and reduction in alcohol consumption. All currently approved agents are indicated for abstinence. This systematic review aimed to identify drugs in development for alcohol dependence treatment and to establish, based upon trial design, if any are seeking market authorization for reduction in consumption. METHODS: We searched PubMed and Embase (December 2001-November 2011) to identify agents in development for alcohol dependence treatment. Additional studies were identified by searching ClinicalTrials.gov and the R&D Insight and Clinical Trials Insight databases. Studies in which the primary focus was treatment of comorbidity, or n≤20, were excluded. Studies were then classified as 'abstinence' if they: described a detoxification/alcohol withdrawal period; enrolled patients who had undergone detoxification previously; or presented relapse/abstinence rates as the primary outcome. Studies in patients actively drinking at baseline were classified as 'reduction in consumption'. RESULTS: Of 602 abstracts identified, 45 full-text articles were eligible. Five monotherapies were in development for alcohol dependence treatment: topiramate, fluvoxamine, aripiprazole, flupenthixol and nalmefene. Nalmefene was the only agent whose sponsor was clearly seeking definitive approval for reduction in consumption. Development status was unclear for topiramate, fluvoxamine, aripiprazole and flupenthixol. Fifteen agents were examined in published exploratory investigator-initiated trials; the majority focused on abstinence. Ongoing (unpublished) trials tended to focus on reduction in consumption. CONCLUSIONS: While published studies generally focused on abstinence, ongoing trials focused on reduction in consumption, suggesting a change in emphasis in the approach to treating alcohol dependence.
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Protein energy wasting (PEW) is common in patients with chronic kidney disease (CKD) and is associated with adverse clinical outcomes, especially in individuals receiving maintenance dialysis therapy. A multitude of factors can affect the nutritional and metabolic status of CKD patients requiring a combination of therapeutic maneuvers to prevent or reverse protein and energy depletion. These include optimizing dietary nutrient intake, appropriate treatment of metabolic disturbances such as metabolic acidosis, systemic inflammation, and hormonal deficiencies, and prescribing optimized dialytic regimens. In patients where oral dietary intake from regular meals cannot maintain adequate nutritional status, nutritional supplementation, administered orally, enterally, or parenterally, is shown to be effective in replenishing protein and energy stores. In clinical practice, the advantages of oral nutritional supplements include proven efficacy, safety, and compliance. Anabolic strategies such as anabolic steroids, growth hormone, and exercise, in combination with nutritional supplementation or alone, have been shown to improve protein stores and represent potential additional approaches for the treatment of PEW. Appetite stimulants, anti-inflammatory interventions, and newer anabolic agents are emerging as novel therapies. While numerous epidemiological data suggest that an improvement in biomarkers of nutritional status is associated with improved survival, there are no large randomized clinical trials that have tested the effectiveness of nutritional interventions on mortality and morbidity.
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BACKGROUND. Ritonavir-boosted saquinavir (SQVr) is nowadays regarded as an alternative antiretroviral drug probably due to several drawbacks, such as its high pill burden, twice daily dosing and the requirement of 200 mg ritonavir when given at the current standard 1000/100 mg bid dosing. Several once-daily SQVr dosing schemes have been studied with the 200 mg SQV old formulations, trying to overcome some of these disadvantages. SQV 500 mg strength tablets became available at the end of 2005, thus facilitating a once-daily regimen with fewer pills, although there is very limited experience with this formulation yet. METHODS. Prospective, multicentre study in which efficacy, safety and pharmacokinetics of a regimen of once-daily SQVr 1500/100 mg plus 2 NRTIs were evaluated under routine clinical care conditions in either antiretroviral-naïve patients or in those with no previous history of antiretroviral treatments and/or genotypic resistance tests suggesting SQV resistance. Plasma SQV trough levels were measured by HPLV-UV. RESULTS. Five hundred and fourteen caucasian patients were included (47.2% coinfected with hepatitis C and/or B virus; 7.8% with cirrhosis). Efficacy at 52 weeks (plasma RNA-HIV <50 copies/ml) was 67.7% (CI95: 63.6 - 71.7%) by intention-to-treat, and 92.2% (CI95: 89.8 - 94.6%) by on-treatment analysis. The reasons for failure were: dropout or loss to follow-up (18.4%), virological failure (7.8%), adverse events (3.1%), and other reasons (4.6%). The high rate of dropout may be explained by an enrollment and follow-up under routine clinical care condition, and a population with a significant number of drug users. The median SQV Cmin (n = 49) was 295 ng/ml (range, 53-2172). The only variable associated with virological failure in the multivariate analysis was adherence (OR: 3.36; CI95, 1.51-7.46, p = 0.003). CONCLUSIONS. Our results suggests that SQVr (1500/100 mg) once-daily plus 2 NRTIs is an effective regimen, without severe clinical adverse events or hepatotoxicity, scarce lipid changes, and no interactions with methadone. All these factors and its once-daily administration suggest this regimen as an appropriate option in patients with no SQV resistance-associated mutations.
Evaluation of two long synthetic merozoite surface protein 2 peptides as malaria vaccine candidates.
Resumo:
Merozoite surface protein 2 (MSP2) is a promising vaccine candidate against Plasmodium falciparum blood stages. A recombinant 3D7 form of MSP2 was a subunit of Combination B, a blood stage vaccine tested in the field in Papua New Guinea. A selective effect in favour of the allelic family not represented by the vaccine argued for a MSP2 vaccine consisting of both dimorphic variants. An alternative approach to recombinant manufacture of vaccines is the production of long synthetic peptides (LSP). LSP exceeding a length of well over 100 amino acids can now be routinely synthesized. Synthetic production of vaccine antigens cuts the often time-consuming steps of protein expression and purification short. This considerably reduces the time for a candidate to reach the phase of clinical trials. Here we present the evaluation of two long synthetic peptides representing both allelic families of MSP2 as potential vaccine candidates. The constructs were well recognized by human immune sera from different locations and different age groups. Furthermore, peptide-specific antibodies in human immune sera were associated with protection from clinical malaria. The synthetic fragments share major antigenic properties with native MSP2. Immunization of mice with these antigens yielded high titre antibody responses and monoclonal antibodies recognized parasite-derived MSP2. Our results justify taking these candidate poly-peptides into further vaccine development.
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Summary Points Brucellosis remains the commonest anthropozoonosis worldwide, and its treatment remains complex, requiring protracted administration of more than one antibiotic. In November 2006, a consensus meeting aimed at reaching a common specialist statement on the treatment of brucellosis was held in Ioannina, Greece under the auspices of the International Society of Chemotherapy and the Institute of Continuing Medical Education of Ioannina. The author panel suggests that the optimal treatment of uncomplicated brucellosis should be based on a six-week regimen of doxycycline combined either with streptomycin for 2–3 weeks, or rifampicin for six weeks. Gentamicin may be considered an acceptable alternative to streptomycin, while all other regimens/combinations should be considered second-line. The development of a common global therapeutic language for human brucellosis, and future, properly conducted clinical trials would definitely solve controversies regarding the disease.
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The in vitro leishmanicidal activity of miltefosine® (Zentaris GmbH) was assessed against four medically relevant Leishmania species of Brazil: Leishmania (Leishmania) amazonensis, Leishmania (Viannia) braziliensis, Leishmania (Viannia) guyanensis and Leishmania (Leishmania) chagasi. The activity of miltefosine against these New World species was compared to its activity against the Old World strain, Leishmania (Leishmania) donovani, which is known to be sensitive to the effects of miltefosine. The IC50 and IC90 results suggested the New World species harboured similar in vitro susceptibilities to miltefosine; however, miltefosine was approximately 20 times more active against the Old World L. (L.) donovani than against the New World L. (L.) chagasi species. The selectivity index varied from 17.2-28.9 for the New World Leishmania species and up to 420.0 for L. (L.) donovani. The differences in susceptibility to miltefosine suggest that future clinical trials with this drug should include a laboratory pre-evaluation and a dose-defining step.
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RotaTeq® (Merck & Company, Inc, Whitehouse Station, NJ, USA) is an oral pentavalent rotavirus vaccine (RV5) that has shown high and consistent efficacy in preventing rotavirus gastroenteritis (RGE) in randomised clinical trials previously conducted in industrialised countries with high medical care resources. To date, the efficacy and effectiveness data for RV5 are available in some Latin American countries, but not Brazil. In this analysis, we projected the effectiveness of RV5 in terms of the percentage reduction in RGE-related hospitalisations among children less than five years of age in four regions of Brazil, using a previously validated mathematical model. The model inputs included hospital-based rotavirus surveillance data from Goiânia, Porto Alegre, Salvador and São Paulo from 2005-2006, which provided the proportions of rotavirus attributable to serotypes G1, G2, G3, G4 and G9, and published rotavirus serotype-specific efficacy from the Rotavirus Efficacy and Safety Trial. The model projected an overall percentage reduction of 93% in RGE-related hospitalisations, with an estimated annual reduction in RGE-related hospitalisations between 42,991-77,383 in the four combined regions of Brazil. These results suggest that RV5 could substantially prevent RGE-related hospitalisations in Brazil.
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Praziquantel (PZQ) is currently the only drug widely used for the treatment of schistosomiasis, but the antimalarial drug mefloquine (Mef) possesses interesting antischistosomal properties. Combination therapy with these two drugs has been suggested as a strategy for transmission control, as PZQ is active against adult worms and Mef is active against schistosomula. To examine the efficacy of combination therapy, Schistosoma mansoni-reinfected mice were separated into seven groups: untreated (I), treated with PZQ in doses of 200 mg/kg (II) or 1,000 mg/kg (III), treated with Mef in doses of 200 mg/kg (IV) or 400 mg/kg (V); each dose was divided equally and given on two consecutive days. Group VI was treated with doses of PZQ + Mef as in groups II and IV, respectively, while group VII was treated with PZQ + Mef as in groups III and V, respectively. PZQ + Mef at the reduced doses of 200 mg/kg each enhanced the therapeutic efficacy over the reduced PZQ dose alone as shown by a very high reduction in the total numbers of mature worms (95% vs. 49%), immature worms (96% vs. 29%) and the complete eradication of immature females, mature females and immature eggs. The reduction in worm burden was associated with the healing of hepatic granulomatous lesions and the normalisation of all liver enzymes. Therefore, the use of Mef with PZQ is more effective than PZQ alone and should be considered for clinical trials in humans as a potential treatment regimen to prevent treatment failures in areas with high rates of schistosomiasis.
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BACKGROUND: Chronic pain is frequent in persons living with spinal cord injury (SCI). Conventionally, the pain is treated pharmacologically, yet long-term pain medication is often refractory and associated with side effects. Non-pharmacological interventions are frequently advocated, although the benefit and harm profiles of these treatments are not well established, in part because of methodological weaknesses of available studies. OBJECTIVES: To critically appraise and synthesise available research evidence on the effects of non-pharmacological interventions for the treatment of chronic neuropathic and nociceptive pain in people living with SCI. SEARCH METHODS: The search was run on the 1st March 2011. We searched the Cochrane Injuries Group's Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (OvidSP), Embase (OvidSP), PsycINFO (OvidSP), four other databases and clinical trials registers. In addition, we manually searched the proceedings of three major scientific conferences on SCI. We updated this search in November 2014 but these results have not yet been incorporated. SELECTION CRITERIA: Randomised controlled trials of any intervention not involving intake of medication or other active substances to treat chronic pain in people with SCI. DATA COLLECTION AND ANALYSIS: Two review authors independently extracted data and assessed risk of bias in the included studies. The primary outcome was any measure of pain intensity or pain relief. Secondary outcomes included adverse events, anxiety, depression and quality of life. When possible, meta-analyses were performed to calculate standardised mean differences for each type of intervention. MAIN RESULTS: We identified 16 trials involving a total of 616 participants. Eight different types of interventions were studied. Eight trials investigated the effects of electrical brain stimulation (transcranial direct current stimulation (tDCS) and cranial electrotherapy stimulation (CES); five trials) or repetitive transcranial magnetic stimulation (rTMS; three trials). Interventions in the remaining studies included exercise programmes (three trials); acupuncture (two trials); self-hypnosis (one trial); transcutaneous electrical nerve stimulation (TENS) (one trial); and a cognitive behavioural programme (one trial). None of the included trials were considered to have low overall risk of bias. Twelve studies had high overall risk of bias, and in four studies risk of bias was unclear. The overall quality of the included studies was weak. Their validity was impaired by methodological weaknesses such as inappropriate choice of control groups. An additional search in November 2014 identified more recent studies that will be included in an update of this review.For tDCS the pooled mean difference between intervention and control groups in pain scores on an 11-point visual analogue scale (VAS) (0-10) was a reduction of -1.90 units (95% confidence interval (CI) -3.48 to -0.33; P value 0.02) in the short term and of -1.87 (95% CI -3.30 to -0.45; P value 0.01) in the mid term. Exercise programmes led to mean reductions in chronic shoulder pain of -1.9 score points for the Short Form (SF)-36 item for pain experience (95% CI -3.4 to -0.4; P value 0.01) and -2.8 pain VAS units (95% CI -3.77 to -1.83; P value < 0.00001); this represented the largest observed treatment effects in the included studies. Trials using rTMS, CES, acupuncture, self-hypnosis, TENS or a cognitive behavioural programme provided no evidence that these interventions reduce chronic pain. Ten trials examined study endpoints other than pain, including anxiety, depression and quality of life, but available data were too scarce for firm conclusions to be drawn. In four trials no side effects were reported with study interventions. Five trials reported transient mild side effects. Overall, a paucity of evidence was found on any serious or long-lasting side effects of the interventions. AUTHORS' CONCLUSIONS: Evidence is insufficient to suggest that non-pharmacological treatments are effective in reducing chronic pain in people living with SCI. The benefits and harms of commonly used non-pharmacological pain treatments should be investigated in randomised controlled trials with adequate sample size and study methodology.
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Cyclin-dependent kinases (CDKs) inhibitors have emerged as interesting therapeutic candidates. Of these, (S)-roscovitine has been proposed as potential neuroprotective molecule for stroke while (R)-roscovitine is currently entering phase II clinical trials against cancers and phase I clinical tests against glomerulonephritis. In addition, (R)-roscovitine has been suggested as potential antihypertensive and anti-inflammatory drug. Dysfunction of intracellular calcium balance is a common denominator of these diseases, and the two roscovitine enantiomers (S and R) are known to modulate calcium voltage channel activity differentially. Here, we provide a detailed description of short- and long-term responses of roscovitine on intracellular calcium handling in renal epithelial cells. Short-term exposure to (S)-roscovitine induced a cytosolic calcium peak, which was abolished after stores depletion with cyclopiazonic acid (CPA). Instead, (R)-roscovitine caused a calcium peak followed by a small calcium plateau. Cytosolic calcium response was prevented after stores depletion. Bafilomycin, a selective vacuolar H(+)-ATPase inhibitor, abolished the small calcium plateau. Long-term exposure to (R)-roscovitine significantly reduced the basal calcium level compared to control and (S)-roscovitine treated cells. However, both enantiomers increased calcium accumulation in the endoplasmic reticulum (ER). Consistently, cells treated with (R)-roscovitine showed a significant increase in SERCA activity, whereas (S)-roscovitine incubation resulted in a reduced PMCA expression. We also found a tonic decreased ability to release calcium from the ER, likely via IP3 signaling, under treatment with (S)- or (R)-roscovitine. Together our data revealed that (S)-roscovitine and (R)-roscovitine exert distinct enantiospecific effects on intracellular calcium signaling in renal epithelial cells. This distinct pharmacological profile can be relevant for roscovitine clinical use.
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Worldwide incidence of malignant melanoma has been constantly increasing during the last years. Surgical excision is effective when primary tumours are thin. At later disease stages patients often succumb, due to failure of metastasis control. Therefore, great efforts have been made to develop improved strategies to treat metastatic melanoma patients. In the search for novel treatments during the last two decades, immunotherapy has occupied a prominent place. Numerous early phase immunotherapy clinical trials, generally involving small numbers of patients each time, have been reported: significant tumour-specific immune responses could often be measured in patients upon treatments. However, clinical responses remain at a dismal low rate. In some anecdotal cases, objective clinical benefit was more frequently observed among immune responders than immune non-responders. This clearly calls for a better understanding of protective immunity against tumours as well as the cross talk taking place between tumours and the immune system. Here we discuss advances and limitations of specific immunotherapy against human melanoma in the light of the literature from the last 5 yr.