Evaluation of 'implications for research' statements in systematic reviews of interventions in advanced cancer patients - a meta-research study.

BACKGROUND: Implications for research (IfR) sections are an important part of systematic reviews (SRs) to inform health care researchers and policy makers. PRISMA 2020 recommends reporting IfR, while Cochrane Reviews require a separate chapter on IfR. However, it is unclear to what extent SRs discuss IfR. We aimed i) to assess whether SRs include an IfR statement and ii) to evaluate which elements informed IfR statements. METHODS: We conducted a meta-research study based on SRs of interventions in advanced cancer patients from a previous project (CRD42019134904). As suggested in the Cochrane Handbook, we assessed if the following predefined variables were referred to in IfR statements: patient, intervention, control, outcome (PICO) and study design; concepts underlying Grading of Recommendations, Assessment, Development and Evaluation (GRADE) domains: risk of bias, inconsistency, indirectness, imprecision, publication bias. Data were independently extracted by three reviewers after piloting the data extraction form. Discrepancies were resolved in weekly in-depth discussions. RESULTS: We included 261 SRs. The majority evaluated a pharmacological intervention (n = 244, 93.5%); twenty-nine were Cochrane Reviews (11.1%). Four out of five SRs included an IfR statement (n = 210, 80.5%). IfR statements commonly addressed 'intervention' (n = 121, 57.6%), 'patient ' (n = 113, 53.8%), and 'study design' (n = 107, 51.0%). The most frequent PICO and study design combinations were 'patient and intervention ' (n = 71, 33.8%) and 'patient, intervention and study design ' (n = 34, 16.2%). Concepts underlying GRADE domains were rarely used for informing IfR recommendations: 'risk of bias ' (n = 2, 1.0%), and 'imprecision ' (n = 1, 0.5%), 'inconsistency ' (n = 1, 0.5%). Additional elements informing IfR were considerations on cost effectiveness (n = 9, 4.3%), reporting standards (n = 4, 1.9%), and individual patient data meta-analysis (n = 4, 1.9%). CONCLUSION: Although about 80% of SRs included an IfR statement, the reporting of PICO elements varied across SRs. Concepts underlying GRADE domains were rarely used to derive IfR. Further work needs to assess the generalizability beyond SRs in advanced cancer patients. We suggest that more specific guidance on which and how IfR elements to report in SRs of interventions needs to be developed. Utilizing PICO elements and concepts underlying GRADE according to the Cochrane Handbook to state IfR seems to be a reasonable approach in the interim. REGISTRATION: CRD42019134904.

Discovery of non-peptidic P2-P3 butanediamide renin inhibitors with high oral efficacy.

A new series of non-peptidic renin inhibitors having a 2-substituted butanediamide moiety at the P2 and P3 positions has been identified. The optimized inhibitors have IC50 values of 0.8 to 1.4 nM and 2.5 to 7.6 nM in plasma renin assays at pH 6.0 and 7.4, respectively. When evaluated in the normotensive cynomolgus monkey model, two of the most potent inhibitors were orally active at a dose as low as 3 mg/kg. These potent renin inhibitors are characterized by oral bioavailabilities of 40 and 89% in the cynomolgus monkey. Inhibitor 3z (BILA 2157 BS) was selected as candidate for pre-development.

Novel small renin inhibitors containing 4,5- or 3,5-dihydroxy-2-substituted-6-phenylhexanamide replacements at the P2-P3 sites.

Renin inhibitors containing a 4,5- or a 3,5-dihydroxy-2-substituted-6-phenylhexanamide fragment at the P2-P3 sites have been prepared and evaluated. The four possible diastereomeric diols of the two series of inhibitors were synthesized to determine the optimal configuration of the carbinol centers for these replacements. The most potent inhibitors of each series, la and 2c have a molecular weight of only 503 and IC50 values of 23 and 20 nM in a human plasma renin assay at pH 6.0. Their very low aqueous solubility limited their further evaluation. The efficacy of these P2-P3 replacements is a result of their ability to maintain the important hydrogen-bonds with the enzyme. Due to conformational differences with the dipeptide, adjustment at the P2 side chain was required. These 4,5- and 3,5-dihydroxyhexanamide segments could be seen as novel N-terminal dipeptide replacements.

N-arylpiperazinyl-N'-propylamino derivatives of heteroaryl amides as functional uroselective alpha 1-adrenoceptor antagonists.

Novel arylpiperazines were identified as alpha 1-adrenoceptor (AR) subtype-selective antagonists by functional in vitro screening. 3-[4-(ortho-Substituted phenyl)piperazin-1-yl]propylamines were derivatized with N,N-dimethyl anthranilamides, nicotinamides, as well as carboxamides of quinoline, 1,8-naphthyridine, pyrazolo[3,4-b]pyridine, isoxazolo[3,4-b]pyridine, imidazo[4,5-b]pyridine, and pyrazolo[1,5-a]pyrimidines. Strips of rabbit bladder neck were employed as a predictive assay for antagonism in the human lower tract. Rings of rat aorta were used as a "negative screen" for the test antagonists. Binding to alpha 1-ARs was relatively sensitive to size and electronic features of the arylpiperazine portion of the antagonists and permissive to these features on the heteroaryl carboxamide side. These structure-affinity findings were exploited to produce nicotinamides (e.g. 13ii and 25x) and pyrazolo[3,4-b]pyridines (e.g. 37f and 37y) ligands with nanomolar affinity at the alpha 1-AR subtype prevalent in the human lower urinary tract(pA2 values: 8.8, 10.7, 9.3, and 9.9, respectively) and displaying 2-3 orders of magnitude selectivity over the alpha 1D-AR.

Effect of metabolites and phosphorylase on the D to I conversion of glycogen synthase from human polymorphonuclear leukocytes.

The D to I conversion of glycogen synthase from human polymorphonuclear leukocytes was examined both in a gel-filtered homogenate and in a preparation of glycogen particles with adhering enzymes, purified by chromatography on concanavalin A bound to Sepharose. It was found that glucose 6-phosphate as well as mannose 6-phosphate, glucosamine 6-phosphate, and 2-deoxy-glucose 6-phosphate activated the reaction, whereas the corresponding sugars were without effect. Mn2+ and Ca2+ increased the conversion rate by 51% and 27%, respectively, whereas Mg2+ and inorganic phosphate were without effect. Sodium fluoride inhibited the reaction completely. Glycogen inhibited the reaction in physiological concentrations and 0.5 mM glucose 6-phosphate was able to overcome this inhibition. MgATP greatly augmented the inhibition caused by glycogen in the glycogen particle preparation. This combined effect could be overcome by glucose 6-phosphate in concentrations from 0.1 to 1 mM. Phosphorylase alpha purified from human polymorphonuclear leukocytes inhibited the D to I conversion in a glycogen particle preparation. The inhibition was counteracted by glucose 6-phosphate and to a lesser degree by AMP. Phosphorylase beta was also inhibitory, but only at higher concentrations than phosphorylase alpha. No phosphorylase phosphatase activity was found in the glycogen particle preparation, which may indicate that chromatography on concanavalin A-Sepharose separates this enzyme from the synthase phosphatase or partially destroys the activity of a hypothetical common protein phosphatase.