Assessing Generative Pretrained Transformers (GPT) in Clinical Decision-Making: Comparative Analysis of GPT-3.5 and GPT-4.

BACKGROUND: Artificial intelligence, particularly chatbot systems, is becoming an instrumental tool in health care, aiding clinical decision-making and patient engagement. OBJECTIVE: This study aims to analyze the performance of ChatGPT-3.5 and ChatGPT-4 in addressing complex clinical and ethical dilemmas, and to illustrate their potential role in health care decision-making while comparing seniors' and residents' ratings, and specific question types. METHODS: A total of 4 specialized physicians formulated 176 real-world clinical questions. A total of 8 senior physicians and residents assessed responses from GPT-3.5 and GPT-4 on a 1-5 scale across 5 categories: accuracy, relevance, clarity, utility, and comprehensiveness. Evaluations were conducted within internal medicine, emergency medicine, and ethics. Comparisons were made globally, between seniors and residents, and across classifications. RESULTS: Both GPT models received high mean scores (4.4, SD 0.8 for GPT-4 and 4.1, SD 1.0 for GPT-3.5). GPT-4 outperformed GPT-3.5 across all rating dimensions, with seniors consistently rating responses higher than residents for both models. Specifically, seniors rated GPT-4 as more beneficial and complete (mean 4.6 vs 4.0 and 4.6 vs 4.1, respectively; P<.001), and GPT-3.5 similarly (mean 4.1 vs 3.7 and 3.9 vs 3.5, respectively; P<.001). Ethical queries received the highest ratings for both models, with mean scores reflecting consistency across accuracy and completeness criteria. Distinctions among question types were significant, particularly for the GPT-4 mean scores in completeness across emergency, internal, and ethical questions (4.2, SD 1.0; 4.3, SD 0.8; and 4.5, SD 0.7, respectively; P<.001), and for GPT-3.5's accuracy, beneficial, and completeness dimensions. CONCLUSIONS: ChatGPT's potential to assist physicians with medical issues is promising, with prospects to enhance diagnostics, treatments, and ethics. While integration into clinical workflows may be valuable, it must complement, not replace, human expertise. Continued research is essential to ensure safe and effective implementation in clinical environments.

The Bacterial Proteasome Inter-domain Is a Selectivity Barrier for Degradation-tag Binding.

Protein degradation, which occurs in all cells, is essential for proper cellular function by regulating many cellular processes, destroying misfolded proteins, and providing protein building blocks under starvation conditions. As proteolysis is a destructive process, it is carried out by tightly regulated enzymes that evolved to interact with their protein substrates in a highly controlled and selective manner. The agents of protein degradation include proteasomes, AAA+ proteolytic machines found in all kingdoms of life. The bacterial proteasome specifically recognizes proteins conjugated to a protein tag termed Pup, with the proteasome regulatory particle, a ring-shaped hexamer termed Mpa in mycobacteria, being responsible for Pup recognition. Once Pup binds Mpa, Pup enters the central pore, where the Mpa AAA+ domain links ATP hydrolysis to the translocation of Pup and its conjugated substrate into a barrel-shaped proteasome core particle, where peptide bond cleavage occurs. As Pup traverses the Mpa pore en route to the AAA+ domain, it passes the inter-domain. Although the inter-domain is conserved in all proteasomes, its role in substrate processing remained unclear. We report here that the Mpa inter-domain promotes Pup binding via electrostatic interactions between conserved charged inter-domain pore loops and charged Pup residues. As such, the inter-domain serves as a gatekeeper that selects for Pup binding, thus facilitating tag interaction with the downstream AAA+ domain. Our findings thus reveal the existence of an additional level of substrate binding regulation in an AAA+ protease.

A comparative systematic review and meta-analysis on the diagnostic accuracy of non-invasive tests for Helicobacter pylori detection in elderly patients.

Background: Helicobacter pylori (H. pylori) infection, a type I carcinogen, affects approximately 50% of the global population, correlating with various gastric pathologies. Notably, diagnostic sensitivities of non-invasive methods, such as the stool antigen test (HpSA), Serology, and Urea Breath Test (UBT), have been suggested to be less effective in older age groups. This study systematically reviews and meta-analyzes the diagnostic accuracy of these tests within the elderly population. Methods: A comprehensive literature search was performed across multiple databases, including PubMed, Medline, and Web of Science, up to July 2023. Data were pooled and analyzed using random-effects models. Sensitivity, specificity, and Diagnostic Odds Ratios (DOR) were computed for the tests. Heterogeneity and risk of bias were assessed. Results: Eight studies involving diverse geographic locations and totaling between 46 and 1,441 participants per study were included. The pooled sensitivity and specificity for HpSA were 72.5 and 94.7%, for Serology 83.7 and 73.3%, and for UBT 96.4 and 88.3%, respectively. DOR for UBT, HpSA, and Serology were 94.5, 47.9, and 14.2, respectively. High levels of heterogeneity were observed across the studies. Conclusion: UBT and HpSA proved effective for diagnosing H. pylori in those over 60, while serology showed lower specificity. Despite methodological variations in available studies, these non-invasive tests offer reliable alternatives, especially for older patients who recently undergone endoscopy or without an indication for it, warranting consideration by healthcare practitioners.

First-Line Efficacy of Anti-HER2 Treatments in Previously Treated HER2-Positive Metastatic Breast Cancer Patients: A Retrospective Observational Study Investigating the Efficacy of Re-Exposure to Anti-HER2 Therapy for HER2-Positive Metastatic Breast Cancer Patients in Comparison with Naïve Patients.

Background: Most patients with HER2-positive metastatic breast cancer (MBC) receive first-line treatment with anti-HER2 agents and have already received anti-HER2 therapy as adjuvant or neoadjuvant therapy in the local setting of their disease presentation. Despite that, they constitute only a minority among clinical trials, and their response to reintroduction to anti-HER2 treatments is inconclusive based upon conflicting studies. We aimed to examine if previous exposure influences the clinical outcome of patients treated with anti-HER2 treatments compared to patients who were naïve to anti-HER2 agents. Methods: We conducted a retrospective observational study of HER2-positive MBC patients who were treated with trastuzumab and pertuzumab from 2014 to 2018. We collected and analyzed data including patients' demographic characteristic as well as extracted data of previous treatment regimens and the efficiency of the anti-HER2 therapy measured by response rate (RR), time to tumor progression (TTP), and overall survival (OS). Results: Eighty patients met the inclusion criteria, 26 (32.5%) of them were previously exposed to anti-HER2 treatments and 54 (67.5%) were not previously exposed to anti-HER2 therapy. No significant differences were detected in RR after 3 months of treatment (p = 0.684). TTP was significantly better among patients with no previous exposure in comparison with patients with previous exposure to anti-HER2 therapy (21 vs. 14 months, p = 0.044) and we noted a trend in better OS (p = 0.056). Conclusion: Our analysis suggests that previous exposure to anti-HER2 agents might influence the clinical outcome of first-line treatment in metastatic HER2 patients. These findings justify further exploration of the benefit of reintroduction of anti-HER2 treatment enabling the optimal treatment for patients with previous anti-HER2 therapy exposure.

Identification of phagocytosis regulators using magnetic genome-wide CRISPR screens.

Phagocytosis is required for a broad range of physiological functions, from pathogen defense to tissue homeostasis, but the mechanisms required for phagocytosis of diverse substrates remain incompletely understood. Here, we developed a rapid magnet-based phenotypic screening strategy, and performed eight genome-wide CRISPR screens in human cells to identify genes regulating phagocytosis of distinct substrates. After validating select hits in focused miniscreens, orthogonal assays and primary human macrophages, we show that (1) the previously uncharacterized gene NHLRC2 is a central player in phagocytosis, regulating RhoA-Rac1 signaling cascades that control actin polymerization and filopodia formation, (2) very-long-chain fatty acids are essential for efficient phagocytosis of certain substrates and (3) the previously uncharacterized Alzheimer's disease-associated gene TM2D3 can preferentially influence uptake of amyloid-ß aggregates. These findings illuminate new regulators and core principles of phagocytosis, and more generally establish an efficient method for unbiased identification of cellular uptake mechanisms across diverse physiological and pathological contexts.

Quantitative Phagocytosis Assays in Primary and Cultured Macrophages.

This chapter describes methods to induce and quantify phagocytosis in primary macrophages and in myeloid cell lines. To this end, we initially detail the isolation of primary human monocytes and their differentiation into macrophages. Because primary cells are comparatively refractory to molecular manipulation, we also describe the culture of RAW 264.7 cells-an immortalized monocyte/macrophage cell line, which is more tractable. The chapter also includes methods for preparation of phagocytic targets, specifically sheep erythrocytes opsonized with immunoglobulin G (IgG), as well as means of distinguishing bound from internalized targets, using fluorescently labeled secondary antibodies.

Multiphasic dynamics of phosphatidylinositol 4-phosphate during phagocytosis.

We analyzed the distribution, fate, and functional role of phosphatidylinositol 4-phosphate (PtdIns4P) during phagosome formation and maturation. To this end, we used genetically encoded probes consisting of the PtdIns4P-binding domain of the bacterial effector SidM. PtdIns4P was found to undergo complex, multiphasic changes during phagocytosis. The phosphoinositide, which is present in the plasmalemma before engagement of the target particle, is transiently enriched in the phagosomal cup. Soon after the phagosome seals, PtdIns4P levels drop precipitously due to the hydrolytic activity of Sac2 and phospholipase C, becoming undetectable for ∼10 min. PtdIns4P disappearance coincides with the emergence of phagosomal PtdIns3P. Conversely, the disappearance of PtdIns3P that signals the transition from early to late phagosomes is accompanied by resurgence of PtdIns4P, which is associated with the recruitment of phosphatidylinositol 4-kinase 2A. The reacquisition of PtdIns4P can be prevented by silencing expression of the kinase and can be counteracted by recruitment of a 4-phosphatase with a heterodimerization system. Using these approaches, we found that the secondary accumulation of PtdIns4P is required for proper phagosomal acidification. Defective acidification may be caused by impaired recruitment of Rab7 effectors, including RILP, which were shown earlier to displace phagosomes toward perinuclear lysosomes. Our results show multimodal dynamics of PtdIns4P during phagocytosis and suggest that the phosphoinositide plays important roles during the maturation of the phagosome.

The life cycle of phagosomes: formation, maturation, and resolution.

Phagocytosis, the regulated uptake of large particles (>0.5 µm in diameter), is essential for tissue homeostasis and is also an early, critical component of the innate immune response. Phagocytosis can be conceptually divided into three stages: phagosome, formation, maturation, and resolution. Each of these involves multiple reactions that require exquisite spatial and temporal orchestration. The molecular events underlying these stages are being unraveled and the current state of knowledge is briefly summarized in this article.

Phosphoinositides in phagocytosis and macropinocytosis.

Professional phagocytes provide immunoprotection and aid in the maintenance of tissue homeostasis. They perform these tasks by recognizing, engulfing and eliminating pathogens and endogenous cell debris. Here, we examine the paramount role played by phosphoinositides in phagocytosis and macropinocytosis, two major endocytic routes that mediate the uptake of particulate and fluid matter, respectively. We analyze accumulating literature describing the molecular mechanisms whereby phosphoinositides translate environmental cues into the complex, sophisticated responses that underlie the phagocytic and macropinocytic responses. In addition, we exemplify virulence strategies involving modulation of host cell phosphoinositide signaling that are employed by bacteria to undermine immunity. This article is part of a Special Issue entitled Phosphoinositides.