Real-World Evidence to Reinforce Clinical Trial Evidence in Health Technology Assessment: A Critical Review of Real-World Evidence Requirements from Seven Countries and Recommendations to Improve Acceptance.

BACKGROUND: Real-world evidence (RWE) can reinforce clinical trial evidence in health technology assessment (HTA). OBJECTIVES: Review HTA bodies' (HTAbs) requirements for RWE, real uses, and acceptance across seven countries (Brazil, Canada, France, Germany, Italy, Spain, and the United Kingdom) and outline recommendations that may improve acceptance of RWE in efficacy/effectiveness assessments and appraisals processes. METHODS: RWE requirements were summarized based on HTAbs' guidelines. Acceptance by HTAbs was evaluated based on industry experience and case studies. RESULTS: As of June 2022, RWE methodological guidelines were in place in three of the seven countries. HTAbs typically requested analyses based on local data sources, but the preferred study design and data sources differed. HTAbs had individual submission, assessment, and appraisal processes; some allowed early meetings for the protocol and/or results validation, though few involved external experts or medical societies to provide input to assessment and appraisal. The extent of submission, assessment, and appraisal requirements did not necessarily reflect the degree of acceptance. CONCLUSION: All the countries reviewed face common challenges regarding the use of RWE. Our proposals address the need to facilitate collaboration and communication with industry and regulatory agencies and the need for specific guidelines describing RWE design and criteria of acceptance throughout the assessment and appraisal processes.

Vectorial signalling mechanism required for cell-cell communication during sporulation in Bacillus subtilis.

Spore formation in Bacillus subtilis takes place in a sporangium consisting of two chambers, the forespore and the mother cell, which are linked by pathways of cell-cell communication. One pathway, which couples the proteolytic activation of the mother cell transcription factor σ(E) to the action of a forespore synthesized signal molecule, SpoIIR, has remained enigmatic. Signalling by SpoIIR requires the protein to be exported to the intermembrane space between forespore and mother cell, where it will interact with and activate the integral membrane protease SpoIIGA. Here we show that SpoIIR signal activity as well as the cleavage of its N-terminal extension is strictly dependent on the prespore fatty acid biosynthetic machinery. We also report that a conserved threonine residue (T27) in SpoIIR is required for processing, suggesting that signalling of SpoIIR is dependent on fatty acid synthesis probably because of acylation of T27. In addition, SpoIIR localization in the forespore septal membrane depends on the presence of SpoIIGA. The orchestration of σ(E) activation in the intercellular space by an acylated signal protein provides a new paradigm to ensure local transmission of a weak signal across the bilayer to control cell-cell communication during development.

Evaluation of emergency department visits prior to an HIV diagnosis: Missed opportunities.

OBJECTIVE: There is a high rate of occult infection and late diagnosis in HIV. Hospital emergency departments (ED) are an important point of health care. The present work aims to know the number of missed opportunities for HIV diagnosis occurring in the ED. METHOD: Retrospective multicenter cohort study that included all patients diagnosed with HIV infection in 2019 in 27 Spanish hospitals in 7 different autonomous communities. All ED consultation episodes in the 5 years prior to diagnosis were reviewed to find out the reason for consultation and whether this represented a missed opportunity for HIV diagnosis. RESULT: Seven hundred twenty-three patients were included, and 352 (48.7%, 95%CI: 45.1%-52.3%) had at least one ED visit during the 5 years prior to diagnosis (median 2, p25-p75: 1-4). One hundred and eighteen patients (16.3%, 95%CI: 13.8%-19.2%) had a missed diagnostic opportunity. The main consultations were drug use [145 (15%)], sexually transmitted infections [91 (9.4%)] and request for post-exposure HIV prophylaxis [39 (4%)]. One hundred and fifty-five (42.9%) of the 352 had less than 350 CD4/mm3 when the HIV diagnosis was established. In patients with previous ED visits, the mean time to diagnosis from this visit was 580 (SD 647) days. CONCLUSIONS: Sixteen percent of patients diagnosed with HIV missed the opportunity to be diagnosed in the 5 years prior to diagnosis, highlighting the need to implement ED screening measures different from current ones to improve these outcomes.

Glycolate combats massive oxidative stress by restoring redox potential in Caenorhabditis elegans.

Upon exposure to excessive reactive oxygen species (ROS), organismal survival depends on the strength of the endogenous antioxidant defense barriers that prevent mitochondrial and cellular deterioration. Previously, we showed that glycolic acid can restore the mitochondrial membrane potential of C. elegans treated with paraquat, an oxidant that produces superoxide and other ROS species, including hydrogen peroxide. Here, we demonstrate that glycolate fully suppresses the deleterious effects of peroxide on mitochondrial activity and growth in worms. This endogenous compound acts by entering serine/glycine metabolism. In this way, conversion of glycolate into glycine and serine ameliorates the drastically decreased NADPH/NADP+ and GSH/GSSG ratios induced by H2O2 treatment. Our results reveal the central role of serine/glycine metabolism as a major provider of reducing equivalents to maintain cellular antioxidant systems and the fundamental function of glycolate as a natural antioxidant that improves cell fitness and survival.

Functional Exchangeability of Oxidase and Dehydrogenase Reactions in the Biosynthesis of Hydroxyphenylglycine, a Nonribosomal Peptide Building Block.

A key problem in the engineering of pathways for the production of pharmaceutical compounds is the limited diversity of biosynthetic enzymes, which restricts the attainability of suitable traits such as less harmful byproducts, enhanced expression features, or different cofactor requirements. A promising synthetic biology approach is to redesign the biosynthetic pathway by replacing the native enzymes by heterologous proteins from unrelated pathways. In this study, we applied this method to effectively re-engineer the biosynthesis of hydroxyphenylglycine (HPG), a building block for the calcium-dependent antibiotic of Streptomyces coelicolor, a nonribosomal peptide. A key step in HPG biosynthesis is the conversion of 4-hydroxymandelate to 4-hydroxyphenylglyoxylate, catalyzed by hydroxymandelate oxidase (HmO), with concomitant generation of H2O2. The same reaction can also be catalyzed by O2-independent mandelate dehydrogenase (MdlB), which is a catabolic enzyme involved in bacterial mandelate utilization. In this work, we engineered alternative HPG biosynthetic pathways by replacing the native HmO in S. coelicolor by both heterologous oxidases and MdlB dehydrogenases from various sources and confirmed the restoration of calcium-dependent antibiotic biosynthesis by biological and UHPLC-MS analysis. The alternative enzymes were isolated and kinetically characterized, confirming their divergent substrate specificities and catalytic mechanisms. These results demonstrate that heterologous enzymes with different physiological contexts can be used in a Streptomyces host to provide an expanded library of enzymatic reactions for a synthetic biology approach. This study thus broadens the options for the engineering of antibiotic production by using enzymes with different catalytic and structural features.

Influence of high concentration monovalent cations on the protein partitioning in polyethyleneglycol 1500-phosphate aqueous two-phase systems.

The influence of chloride salts of Na+, Rb+ and Cs+ at concentrations from 0.15 to 1.2M was studied with bovine albumin, trypsin, ovoalbumin and lysozyme partitioning in an aqueous two-phase system formed by polyethyleneglycol 1500 and potassium phosphate at pH 7.4. Monovalent cations favoured the protein transfer to the polyethyleneglycol rich phase in the following order: Rb+ > Na+ > Cs+. Structure making cations as Na+ induced a poor loss of structured water, producing little diminution of the molar partial specific volume of polyethyleneglycol, while Rb+ and Cs+, structure breaking cations, induced a significant decrease in the specific volume of the polyethylene glycol. The increase of available solution free volume in the top phase favours the protein transfer to the polyethyleneglycol rich phase. Na+ and Rb+ induced a slight decrease in the alpha helix content of the proteins, while Cs+ increased the secondary structure for all the proteins. All the cations induced a decrease in the hydrophobic surface of the proteins, this effect was more significant in the presence of Cs+.