How can clinicians choose between conflicting and discordant systematic reviews? A replication study of the Jadad algorithm.

INTRODUCTION: The exponential growth of published systematic reviews (SRs) presents challenges for decision makers seeking to answer clinical, public health or policy questions. In 1997, an algorithm was created by Jadad et al. to choose the best SR across multiple. Our study aims to replicate author assessments using the Jadad algorithm to determine: (i) if we chose the same SR as the authors; and (ii) if we reach the same results. METHODS: We searched MEDLINE, Epistemonikos, and Cochrane Database of SRs. We included any study using the Jadad algorithm. We used consensus building strategies to operationalise the algorithm and to ensure a consistent approach to interpretation. RESULTS: We identified 21 studies that used the Jadad algorithm to choose one or more SRs. In 62% (13/21) of cases, we were unable to replicate the Jadad assessment and ultimately chose a different SR than the authors. Overall, 18 out of the 21 (86%) independent Jadad assessments agreed in direction of the findings despite 13 having chosen a different SR. CONCLUSIONS: Our results suggest that the Jadad algorithm is not reproducible between users as there are no prescriptive instructions about how to operationalise the algorithm. In the absence of a validated algorithm, we recommend that healthcare providers, policy makers, patients and researchers address conflicts between review findings by choosing the SR(s) with meta-analysis of RCTs that most closely resemble their clinical, public health, or policy question, are the most recent, comprehensive (i.e. number of included RCTs), and at the lowest risk of bias.

Unraveling amino acid residues critical for allosteric potentiation of (α4)3(ß2)2-type nicotinic acetylcholine receptor responses.

Neuronal nicotinic acetylcholine receptors (nAChRs) are promising drug targets to manage several neurological disorders and nicotine addiction. Growing evidence indicates that positive allosteric modulators of nAChRs improve pharmacological specificity by binding to unique sites present only in a subpopulation of nAChRs. Furthermore, nAChR positive allosteric modulators such as NS9283 and CMPI have been shown to potentiate responses of (α4)3(ß2)2 but not (α4)2(ß2)3 nAChR isoforms. This selective potentiation underlines that the α4:α4 interface, which is present only in the (α4)3(ß2)2 nAChR, is an important and promising drug target. In this report we used site-directed mutagenesis to substitute specific amino acid residues and computational analyses to elucidate CMPI's binding mode at the α4:α4 subunit extracellular interface and identified a unique set of amino acid residues that determined its affinity. We found that amino acid residues α4Gly-41, α4Lys-64, and α4Thr-66 were critical for (α4)3(ß2)2 nAChR potentiation by CMPI, but not by NS9283, whereas amino acid substitution at α4His-116, a known determinant of NS9283 and of agonist binding at the α4:α4 subunit interface, did not reduce CMPI potentiation. In contrast, substitutions at α4Gln-124 and α4Thr-126 reduced potentiation by CMPI and NS9283, indicating that their binding sites partially overlap. These results delineate the role of amino acid residues contributing to the α4:α4 subunit extracellular interface in nAChR potentiation. These findings also provide structural information that will facilitate the structure-based design of novel therapeutics that target selectively the (α4)3(ß2)2 nAChR.

Effect of maternal oral hydration therapy in oligohydramnios.

This was a randomized controlled trial on 64 pregnant women from 32 to 35 weeks gestation, in one year period to determine the effect of maternal hydration by oral water in oligohydramnios amniotic fluid index (AFI) ≤ 5. Studied women were randomly divided into two groups. Group A (intervention group) women were instructed to drink 2 liters of water within 2 hours and from the next day extra 2 liters of water daily for 7 days. Group B (control group) women were allowed for routine water intake. AFI was done after 2 hours, 24 hours and 7 days of oral hydration therapy in both the groups. P values less than 0.05 was considered statistically significant. Pre-treatment mean AFI was 4.77 ± 0.42 (mean ± SD) vs. 4.80 ± 0.43 (mean ± SD) and post treatment AFI after 2 hours was 6.35 ± 0.65 vs. 4.81 ± 0.42; after 7 days was 7.08 ± 0.21 vs. 5.0 ± 0.20 in oral hydration group and control group respectively. Delivery at 37-40 weeks was 53.1% vs. 12.4%, normal vaginal delivery in 71% vs. 21.8%, caesarean section in 29% vs. 78.2% and low birth weight babies were 12.5% vs. 81.25% in intervention and control group respectively. Foetal outcome was healthy in 87.1% vs. 59.4%, asphyxiated in 12.9% vs. 50% and perinatal death was 3.22% vs. 21.8% between intervention and control group. Still born were 6.3% cases in control group. Maternal oral hydration therapy significantly increases the AFI, reduces the caesarean section rate and improves the foetal outcome.

Intrauterine Limb Ischemia in Patient Heterozygous for the 677C>T) RS1801133 (Polymorphism of Methylenetetrahydrofolate Reductase MTHR Gene.

Background: Intrauterine arterial thrombosis is extremely rare. Multiple inherited coagulopathies were found to be associated with thrombophilia and an increased risk of intrauterine arterial thrombosis. Methylenetetrahydrofolate reductase MTHFR (C667T) polymorphism was found to be associated with mild hyper-homocysteinemia, which, in turn, can promote thrombotic complications. Materials and Methods: We reported a case of intrauterine upper limb ischemia in a neonate who was found to be heterozygous for the 677C > T polymorphism of the MTHFR gene despite the dispute regarding its clinical significance as a risk of arterial thrombosis. We also reviewed the literature and summarized the clinical features, treatment, and prognosis of similar cases. Case Presentation. We reported a full-term female, born by normal spontaneous vaginal delivery who was found to have a swollen, blue left upper limb in the delivery room. Left upper limb computed tomography angiography (CTA) revealed left subclavian artery thrombosis. Investigations for the risk revealed heterozygosity for the MTHFR (C667T) polymorphism. Left upper limb amputation was done after the failure of medical management. Conclusion: Despite the conflict about whether heterozygosity for MTHFR (C667T) polymorphism increases the risk of arterial thrombosis or not, there are few cases in the literature presented with intrauterine upper limb ischemia and were found to be heterozygous for the mutation. We recommend investigating neonates and their parents for complete thrombophilia mutations when they present with unusual vascular occlusion sites as newborns.

Orthosteric and Allosteric Ligands of Nicotinic Acetylcholine Receptors for Smoking Cessation.

Nicotine addiction, the result of tobacco use, leads to over six million premature deaths world-wide per year, a number that is expected to increase by a third within the next two decades. While more than half of smokers want and attempt to quit, only a small percentage of smokers are able to quit without pharmacological interventions. Therefore, over the past decades, researchers in academia and the pharmaceutical industry have focused their attention on the development of more effective smoking cessation therapies, which is now a growing 1.9 billion dollar market. Because the role of neuronal nicotinic acetylcholine receptors (nAChR) in nicotine addiction is well established, nAChR based therapeutics remain the leading strategy for smoking cessation. However, the development of neuronal nAChR drugs that are selective for a nAChR subpopulation is challenging, and only few neuronal nAChR drugs are clinically available. Among the many neuronal nAChR subtypes that have been identified in the brain, the α4ß2 subtype is the most abundant and plays a critical role in nicotine addiction. Here, we review the role of neuronal nAChRs, especially the α4ß2 subtype, in the development and treatment of nicotine addiction. We also compare available smoking cessation medications and other nAChR orthosteric and allosteric ligands that have been developed with emphasis on the difficulties faced in the development of clinically useful compounds with high nAChR subtype selectivity.