Structures of LRP2 reveal a molecular machine for endocytosis.

The low-density lipoprotein (LDL) receptor-related protein 2 (LRP2 or megalin) is representative of the phylogenetically conserved subfamily of giant LDL receptor-related proteins, which function in endocytosis and are implicated in diseases of the kidney and brain. Here, we report high-resolution cryoelectron microscopy structures of LRP2 isolated from mouse kidney, at extracellular and endosomal pH. The structures reveal LRP2 to be a molecular machine that adopts a conformation for ligand binding at the cell surface and for ligand shedding in the endosome. LRP2 forms a homodimer, the conformational transformation of which is governed by pH-sensitive sites at both homodimer and intra-protomer interfaces. A subset of LRP2 deleterious missense variants in humans appears to impair homodimer assembly. These observations lay the foundation for further understanding the function and mechanism of LDL receptors and implicate homodimerization as a conserved feature of the LRP receptor subfamily.

Diagnostic accuracy of haematoxylin-eosin staining in comparison to calretinin and S100 for the assessment of ganglion cells in rectal biopsy.

OBJECTIVE: To assess the diagnostic accuracy of haematoxylin-eosin staining in clinically suspected Hirschsprung disease, and to compare the findings with calretinin and S100 immunohistochemistry. METHODS: The retrospective study was conducted at the AL-Khansaa Teaching Hospital, Nineveh, Iraq, and comprised data from January 2017 to October 2020 of rectal suction biopsies of patients with clinically and radiologically suspected Hirschsprung disease. Histopathology and immunohistochemistry were performed. Data was analysed using SPSS 16. RESULTS: Of the 114 patients, 74(64.9%) were males and 40(35.1%) were females. Based on histology, 28(24.6%) cases were negative for ganglion cells, and, of them 25(89.2%) revealed nerve bundle hypertrophy. The diagnostic accuracy for the detection of ganglion cell and nerve hypertrophy using haematoxylin-eosin stain was 99.1% and 94.4%, respectively. Correlation of haematoxylin-eosin staining with calretinin and S100 was statistically near perfection (κ= 0.976 and κ = 0.923), respectively. CONCLUSIONS: The mainstay to confirm or exclude Hirschsprung disease remains an accurate histopathological evaluation of the haematoxylin-eosin-stained sections of an adequate colorectal biopsy.

Biotransformation of hydrocortisone succinate with whole cell cultures of Monascus purpureus and Cunninghamella echinulata.

Hydrocortisone succinate (1) is a synthetic anti-inflammatory drug and key intermediate in the synthesis of other steroidal drugs. This work is based on the fungal biotransformation of 1, using Monascus purpureus and Cunninghamella echinulata strains. Comopound 1 was transformed into four metabolites, identified as hydrocortisone (2), 11ß-hydroxyandrost-4-en-3,17-dione (3), Δ1-cortienic acid (4), and hydrocortisone-17-succinate (5), obtained through side chain cleavage, hydrolysis, dehydrogenation, and oxidation reactions. These compounds have previously been synthesized either chemically or enzymatically from different precursors. Though this is not the first report on the biotransformation of 1, but it obviously is a first, where the biotransformed products of compound 1 have been characterized structurally with the help of modern spectroscopic techniques. It is noteworthy that these products have already shown biological potential, however a more thorough investigation of the anti-inflammatory properties of these metabolites would be of high value. These results not only emphasize upon the immense potential of biotransformation in catalysis of reactions, otherwise not-achievable chemically, but also holds promise for the development of novel anti-inflammatory compounds.

Nematode Extracellular Protein Interactome Expands Connections between Signaling Pathways.

Multicellularity was accompanied by the emergence of new classes of cell surface and secreted proteins. The nematode C. elegans is a favorable model to study cell surface interactomes, given its well-defined and stereotyped cell types and intercellular contacts. Here we report our C. elegans extracellular interactome dataset, the largest yet for an invertebrate. Most of these interactions were unknown, despite recent datasets for flies and humans, as our collection contains a larger selection of protein families. We uncover new interactions for all four major axon guidance pathways, including ectodomain interactions between three of the pathways. We demonstrate that a protein family known to maintain axon locations are secreted receptors for insulins. We reveal novel interactions of cystine-knot proteins with putative signaling receptors, which may extend the study of neurotrophins and growth-factor-mediated functions to nematodes. Finally, our dataset provides insights into human disease mechanisms and how extracellular interactions may help establish connectomes.

What makes joint assessment procedures attractive to the innovative industry: successes, challenges, and proposed improvements.

Regulatory harmonization and convergence have been identified as the key driver in promoting efficient evaluation of medicines, reducing workload, and supporting earlier access to medicines on the African continent. There has been great progress to date in enhancing regulatory harmonization and convergence on the African continent via the Regional Economic Communities (RECs) and with the establishment of the Africa Medicines Agency (AMA). In this article, the International Federation of Pharmaceutical Manufacturers and Associations (IFPMA) Africa Regulatory Network (ARN) presents its perspective based on the available literature review and results from a survey conducted with innovative biopharmaceutical companies to gather experiences using regional joint assessment procedures (JAPs) in Africa, such as the East African Community Medicines Regulatory Harmonization (EAC-MRH), the West African Medicines Regulatory Harmonization (WA-MRH), and the Southern African Development Community Medicines Regulatory Harmonization (SADC-MRH) initiative through the ZAZIBONA Collaborative Procedure for Medicines Registration (ZaZiBoNa), and provides best practices in this evolving landscape. The article also assesses other collaborative registration pathways available to facilitating registration of pharmaceutical products in African countries, such as WHO Collaborative Registration Procedures (CRP), Swissmedic's Marketing Authorisation for Global Health Products (MAGHP) and EU Medicines for All (EU-M4ALL). Benefits and challenges of each of the existing pathways are discussed in this article. Main benefits include building more expert capacity and improved collaboration amongst experts, as well as shorter review timelines in some cases. Key challenges include the lack of predictability in the adherence to procedural timelines as defined per guidelines, lengthy timeline to achieve national marketing authorization following joint assessment, the lack of dedicated personnel, administrative issues during the submission process as well as additional country-specific requirements on top of JAP-specific requirements. Our recommendations for improvements include harmonization of requirements across countries and regions and with international standards, appropriate resource allocation for JAP activities to ensure adherence to timelines, use of JAPs throughout the entire product lifecycle and all product categories, adequate use of digital technologies, and improved communication and transparency with applicants. These improvements will allow industry to better plan their filing strategies for the region which will lead to overall improved usability of the JAPs in Africa and enable faster patient access.

Cost-Effectiveness of Pharmacotherapy for the Treatment of Obesity in Adolescents.

Importance: Antiobesity pharmacotherapy is recommended for adolescents ages 12 years and older with obesity. Several medications have been approved by the US Food and Drug Administration for adolescent use, but the most cost-effective medication remains unclear. Objective: To estimate the cost-effectiveness of lifestyle counseling alone and as adjunct to liraglutide, mid-dose phentermine and topiramate (7.5 mg phentermine and 46 mg topiramate), top-dose phentermine and topiramate (15 mg phentermine and 92 mg topiramate), or semaglutide among adolescent patients with obesity. Design, Setting, and Participants: This economic evaluation used a microsimulation model to project health and cost outcomes of lifestyle counseling alone and adjunct to liraglutide, mid-dose phentermine and topiramate, top-dose phentermine and topiramate, or semaglutide over 13 months, 2 years, and 5 years among a hypothetical cohort of 100 000 adolescents with obesity, defined as an initial body mass index (BMI; calculated as weight in kilograms divided by height in meters squared) of 37. Model inputs were derived from clinical trials, published literature, and national sources. Data were analyzed from April 2022 to July 2023. Exposures: Lifestyle counseling alone and as adjunct to liraglutide, mid-dose phentermine and topiramate, top-dose phentermine and topiramate, or semaglutide. Main Outcomes and Measures: The main outcome was quality-adjusted life years (QALYs), costs (2022 US dollars), and incremental cost-effectiveness ratios (ICERs), with future costs and QALYs discounted 3.0% annually. A strategy was considered cost-effective if the ICER was less than $100 000 per QALY gained. The preferred strategy was determined as the strategy with the greatest increase in QALYs while being cost-effective. One-way and probabilistic sensitivity analyses were used to assess parameter uncertainty. Results: The model simulated 100 000 adolescents at age 15 with an initial BMI of 37, of whom 58 000 (58%) were female. At 13 months and 2 years, lifestyle counseling was estimated to be the preferred strategy. At 5 years, top-dose phentermine and topiramate was projected to be the preferred strategy with an ICER of $56 876 per QALY gained vs lifestyle counseling. Semaglutide was projected to yield the most QALYs, but with an unfavorable ICER of $1.1 million per QALY gained compared with top-dose phentermine and topiramate. Model results were most sensitive to utility of weight reduction and weight loss of lifestyle counseling and top-dose phentermine and topiramate. Conclusions and Relevance: In this economic evaluation of pharmacotherapy for adolescents with obesity, top-dose phentermine and topiramate as adjunct to lifestyle counseling was estimated to be cost-effective after 5 years. Long-term clinical trials in adolescents are needed to fully evaluate the outcomes of pharmacotherapy, especially into adulthood.

Cost-Effectiveness of Liquid Biopsy for Colorectal Cancer Screening in Patients Who Are Unscreened.

Importance: Despite recommendations for universal screening, adherence to colorectal cancer screening in the US is approximately 60%. Liquid biopsy tests are in development for cancer early detection, but it is unclear whether they are cost-effective for colorectal cancer screening. Objective: To estimate the cost-effectiveness of liquid biopsy for colorectal cancer screening in the US. Design, Setting, and Participants: In this economic evaluation, a Markov model was developed to compare no screening and 5 colorectal cancer screening strategies: colonoscopy, liquid biopsy, liquid biopsy following nonadherence to colonoscopy, stool DNA, and fecal immunochemical test. Adherence to first-line screening with colonoscopy, stool DNA, or fecal immunochemical test was assumed to be 60.6%, and adherence for liquid biopsy was assumed to be 100%. For colonoscopy, stool DNA, and fecal immunochemical test, patients who did not adhere to testing were not offered other screening. In colonoscopy-liquid biopsy hybrid, liquid biopsy was second-line screening for those who deferred colonoscopy. Scenario analyses were performed to include the possibility of polyp detection for liquid biopsy. Exposures: No screening, colonoscopy, fecal immunochemical test, stool DNA, liquid biopsy, and colonoscopy-liquid biopsy hybrid screening. Main Outcomes and Measures: Model outcomes included life expectancy, total cost, and incremental cost-effectiveness ratios. A strategy was considered cost-effective if it had an incremental cost-effectiveness ratio less than the US willingness-to-pay threshold of $100 000 per life-year gained. Results: This study used a simulated cohort of patients aged 45 years with average risk of colorectal cancer. In the base case, colonoscopy was the preferred, or cost-effective, strategy with an incremental cost-effectiveness ratio of $28 071 per life-year gained. Colonoscopy-liquid biopsy hybrid had the greatest gain in life-years gained but had an incremental cost-effectiveness ratio of $377 538. Colonoscopy-liquid biopsy hybrid had a greater gain in life-years if liquid biopsy could detect polyps but remained too costly. Conclusions and Relevance: In this economic evaluation of liquid biopsy for colorectal cancer screening, colonoscopy was a cost-effective strategy for colorectal cancer screening in the general population, and the inclusion of liquid biopsy as a first- or second-line screening strategy was not cost-effective at its current cost and screening performance. Liquid biopsy tests for colorectal cancer screening may become cost-effective if their cost is substantially lowered.

Quantifying the potential benefits of early detection for pancreatic cancer through a counterfactual simulation modeling analysis.

The benefits of cancer early detection depend on various factors, including cancer type, screening method performance, stage at diagnosis, and subsequent treatment. Although numerous studies have evaluated the effectiveness of screening interventions for identifying cancer at earlier stages, there is no quantitative analysis that studies the optimal early detection time interval that results in the greatest mortality benefit; such data could serve as a target and benchmark for cancer early detection strategies. In this study, we focus on pancreatic ductal adenocarcinoma (PDAC), a cancer known for its lack of early symptoms. Consequently, it is most often detected at late stages when the 5-year survival rate is only 3%. We developed a PDAC population model that simulates an individual patient's age and stage at diagnosis, while replicating overall US cancer incidence and mortality rates. The model includes "cancer sojourn time," serving as a proxy for the speed of cancer progression, with shorter times indicating rapid progression and longer times indicating slower progression. In our PDAC model, our hypothesis was that earlier cancer detection, potentially through a hypothetical screening intervention in the counterfactual analysis, would yield reduced mortality as compared to a no-screening group. We found that the benefits of early detection, such as increased life-years gained, are greater when the sojourn time is shorter, reaching their maximum when identification is made 4-6 years prior to clinical diagnosis (e.g., when a symptomatic diagnosis is made). However, when early detection occurs even earlier, for example 6-10 years prior to clinical diagnosis, the benefits significantly diminish for shorter sojourn time cancers, and level off for longer sojourn time cancers. Our study clarifies the potential benefits of PDAC early detection that explicitly incorporates individual patient heterogeneity in cancer progression and identifies quantitative benchmarks for future interventions.

RAF1 deficiency causes a lethal syndrome that underscores RTK signaling during embryogenesis.

Somatic and germline gain-of-function point mutations in RAF, one of the first oncogenes to be discovered in humans, delineate a group of tumor-prone syndromes known as the RASopathies. In this study, we document the first human phenotype resulting from the germline loss-of-function of the proto-oncogene RAF1 (a.k.a. CRAF). In a consanguineous family, we uncovered a homozygous p.Thr543Met variant segregating with a neonatal lethal syndrome with cutaneous, craniofacial, cardiac, and limb anomalies. Structure-based prediction and functional tests using human knock-in cells showed that threonine 543 is essential to: (i) ensure RAF1's stability and phosphorylation, (ii) maintain its kinase activity toward substrates of the MAPK pathway, and (iii) protect from stress-induced apoptosis mediated by ASK1. In Xenopus embryos, mutant RAF1T543M failed to phenocopy the effects of normal and overactive FGF/MAPK signaling, confirming its hypomorphic activity. Collectively, our data disclose the genetic and molecular etiology of a novel lethal syndrome with progeroid features, highlighting the importance of RTK signaling for human development and homeostasis.

Endovascular Coiling Versus Neurosurgical Clipping for Aneurysmal Subarachnoid Hemorrhage: A Systematic Review and Meta-analysis.

Background Aneurysmal subarachnoid hemorrhage is a frequently devastating condition with a reported incidence of between 10 and 15 people per 100,000 in the United States. Currently, according to the best of our knowledge, there are not enough meta-analyses available in the medical literature of the last five years which compare the risks and benefits of endovascular coiling with neurosurgical clipping. Methods Twenty-two studies were selected out of the short-listed studies. The studies were selected on the basis of relevance to the topic, sample size, sampling technique, and randomization. Data were analyzed on Revman software. Results Mortality was found to be significantly higher in the endovascular coiling group (odds ratio (OR): 1.17; confidence interval (CI): 95%, 1.04, 1.32). Re-bleeding was significantly higher in endovascular coiling (OR: 2.87; CI: 95%, 1.67, 4.93). Post-procedure complications were significantly higher in neurosurgical clipping compared to endovascular coiling (OR: 0.36; CI: 95%, 0.24, 0.56). Neurosurgical clipping was a 3.82 times better surgical technique in terms of re-bleeding (Z = 3.82, p = 0.0001). Neurosurgical clipping is a better technique requiring fewer re-treatments compared to endovascular coiling (OR: 4.64; CI: 95%, 2.31, 9.29). Endovascular coiling was found to be a better technique as it requires less rehabilitation compared to neurosurgical clipping (OR: 0.75; CI: 95%, 0.64,0.87). Conclusion Neurosurgical clipping provides better results in terms of mortality, re-bleeding, and re-treatments. Endovascular coiling is a better surgical technique in terms of post-operative complications, favorable outcomes, and rehabilitation.