Send it, receive it, quick erase it: A mouse model to decipher chemokine communication.

A method to precisely determine which cells respond to chemokines in vivo is currently lacking. A novel class of dual fluorescence reporter mice could help identify cells that produce and/or sense a given chemokine in vitro and in vivo (Rodrigo et al. 2024. J. Exp. Med.https://doi.org/10.1084/jem.20231814).

MEF2C regulates NK cell effector functions through control of lipid metabolism.

Natural killer (NK) cells are a critical first line of defense against viral infection. Rare mutations in a small subset of transcription factors can result in decreased NK cell numbers and function in humans, with an associated increased susceptibility to viral infection. However, our understanding of the specific transcription factors governing mature human NK cell function is limited. Here we use a non-viral CRISPR-Cas9 knockout screen targeting genes encoding 31 transcription factors differentially expressed during human NK cell development. We identify myocyte enhancer factor 2C (MEF2C) as a master regulator of human NK cell functionality ex vivo. MEF2C-haploinsufficient patients and mice displayed defects in NK cell development and effector function, with an increased susceptibility to viral infection. Mechanistically, MEF2C was required for an interleukin (IL)-2- and IL-15-mediated increase in lipid content through regulation of sterol regulatory element-binding protein (SREBP) pathways. Supplementation with oleic acid restored MEF2C-deficient and MEF2C-haploinsufficient patient NK cell cytotoxic function. Therefore, MEF2C is a critical orchestrator of NK cell antiviral immunity by regulating SREBP-mediated lipid metabolism.

'Long-term outcomes after endoscopic submucosal dissection for relative indication early gastric cancer in non-surgical candidates'.

BACKGROUND AND AIMS: Endoscopic submucosal dissection (ESD) is effective in treating early gastric cancer (EGC). It's role in the comorbid with more advanced disease is unknown. We sought to evaluate this in a large Western cohort. METHODS: Consecutive patients who underwent ESD for EGC in a single tertiary Western endoscopy centre over 10 years were prospectively analyzed. The primary outcomes were long term overall survival (OS) and disease-free survival (DFS) up to 5 years. Secondary outcomes were efficacy and serious adverse events (SAE). RESULTS: ESD for 157 EGC in 149 patients were performed in an elderly and comorbid cohort with mean age 73.7 years and age-adjusted Charleson Comorbidity Index 4.2. Over a median follow-up period of 51.6 months, there was no significant difference in 5-year OS (88.9% vs 77.9%, P = 0.290) and DFS (83.2% vs 75.1%, P = 0.593) between absolute indication (AI) EGC and relative indication (RI) EGC. AI EGC cohort achieved higher en bloc (96.3% vs 87.5%, P = 0.069) and R0 resection rate (93.6% vs 62.5%, P <0.001) when compared to RI EGC. There were no significant differences in SAE (7.3% vs 12.5%, P = 0.363). No mortality or surgical resection ensued from ESD complications. CONCLUSION: ESD safely confers DFS in poor surgical candidates with RI EGC in a large Western cohort. Patients who are elderly and comorbid or decline surgical resection may benefit from ESD and avoid the risks of surgery and its long-term sequelae.

No time to die: Epigenetic regulation of natural killer cell survival.

NK cells are short-lived innate lymphocytes that can mediate antigen-independent responses to infection and cancer. However, studies from the past two decades have shown that NK cells can acquire transcriptional and epigenetic modifications during inflammation that result in increased survival and lifespan. These findings blur the lines between the innate and adaptive arms of the immune system, and suggest that the homeostatic mechanisms that govern the persistence of innate immune cells are malleable. Indeed, recent studies have shown that NK cells undergo continuous and strictly regulated adaptations controlling their survival during development, tissue residency, and following inflammation. In this review, we summarize our current understanding of the critical factors regulating NK cell survival throughout their lifespan, with a specific emphasis on the epigenetic modifications that regulate the survival of NK cells in various contexts. A precise understanding of the molecular mechanisms that govern NK cell survival will be important to enhance therapies for cancer and infectious diseases.

A simplified algorithm to evaluate the risk of submucosal invasive cancer in large (≥20 mm) nonpedunculated colonic polyps.

BACKGROUND: Recognition of submucosal invasive cancer (SMIC) in large (≥20 mm) nonpedunculated colonic polyps (LNPCPs) informs selection of the optimal resection strategy. LNPCP location, morphology, and size influence the risk of SMIC; however, currently no meaningful application of this information has simplified the process to make it accessible and broadly applicable. We developed a decision-making algorithm to simplify the identification of LNPCP subtypes with increased risk of potential SMIC. METHODS: Patients referred for LNPCP resection from September 2008 to November 2022 were enrolled. LNPCPs with SMIC were identified from endoscopic resection specimens, lesion biopsies, or surgical outcomes. Decision tree analysis of lesion characteristics identified in multivariable analysis was used to create a hierarchical classification of SMIC prevalence. RESULTS: 2451 LNPCPs were analyzed: 1289 (52.6%) were flat, 1043 (42.6%) nodular, and 118 (4.8%) depressed. SMIC was confirmed in 273 of the LNPCPs (11.1%). It was associated with depressed and nodular vs. flat morphology (odds ratios [ORs] 35.7 [95%CI 22.6-56.5] and 3.5 [95%CI 2.6-4.9], respectively; P<0.001); rectosigmoid vs. proximal location (OR 3.2 [95%CI 2.5-4.1]; P<0.001); nongranular vs. granular appearance (OR 2.4 [95%CI 1.9-3.1]; P<0.001); and size (OR 1.12 per 10-mm increase [95%CI 1.05-1.19]; P<0.001). Decision tree analysis targeting SMIC identified eight terminal nodes: SMIC prevalence was 62% in depressed LNPCPs, 19% in nodular rectosigmoid LNPCPs, and 20% in nodular proximal colon nongranular LNPCPs. CONCLUSIONS: This decision-making algorithm simplifies identification of LNPCPs with an increased risk of potential SMIC. When combined with surface optical evaluation, it facilitates accurate lesion characterization and resection choices.

Suppression of adaptive NK cell expansion by macrophage-mediated phagocytosis inhibited by 2B4-CD48.

Infection of mice by mouse cytomegalovirus (MCMV) triggers activation and expansion of Ly49H+ natural killer (NK) cells, which are virus specific and considered to be "adaptive" or "memory" NK cells. Here, we find that signaling lymphocytic activation molecule family receptors (SFRs), a group of hematopoietic cell-restricted receptors, are essential for the expansion of Ly49H+ NK cells after MCMV infection. This activity is largely mediated by CD48, an SFR broadly expressed on NK cells and displaying augmented expression after MCMV infection. It is also dependent on the CD48 counter-receptor, 2B4, expressed on host macrophages. The 2B4-CD48 axis promotes expansion of Ly49H+ NK cells by repressing their phagocytosis by virus-activated macrophages through inhibition of the pro-phagocytic integrin lymphocyte function-associated antigen-1 (LFA-1) on macrophages. These data identify key roles of macrophages and the 2B4-CD48 pathway in controlling the expansion of adaptive NK cells following MCMV infection. Stimulation of the 2B4-CD48 axis may be helpful in enhancing adaptive NK cell responses for therapeutic purposes.

When less is more: lower esophageal sphincter-preserving peroral endoscopic myotomy is effective for non-achalasia esophageal motility disorders.

BACKGROUND: Non-achalasia esophageal motility disorders (NAEMDs), encompassing distal esophageal spasm (DES) and hypercontractile esophagus (HCE), are rare conditions. Peroral endoscopic myotomy (POEM) is a promising treatment option. In NAEMDs, unlike with achalasia, the lower esophageal sphincter (LES) functions normally, suggesting the potential of LES preservation during POEM. METHODS: This retrospective two-center observational study focused on patients undergoing LES-preserving POEM (LES-POEM) for NAEMD. Eckardt scores were assessed pre-POEM and at 6, 12, and 24 months post-POEM, with follow-up endoscopy at 6 months to evaluate for reflux esophagitis. Clinical success, defined as an Eckardt score ≤3, served as the primary outcome. RESULTS: 227 patients were recruited over 84 months until May 2021. Of these, 16 underwent LES-POEM for an NAEMD (9 with HCE and 7 with DES). The median pre-POEM Eckardt score was 6.0 (interquartile range [IQR] 5.0-7.0), which decreased to 1.0 (IQR 0.0-1.8; P<0.001) 6 months post-POEM. This was sustained at 24 months, with an Eckardt score of 1.0 (IQR 0.0-1.8; P<0.001). Two patients (12.5%) developed Los Angeles grade A or B esophagitis. CONCLUSIONS: LES-POEM for NAEMD demonstrates favorable clinical outcomes, with infrequent esophagitis and reintervention for LES dysfunction rarely required.

Trypanosoma cruzi Reactivation After Chimeric Antigen Receptor T-Cell Therapy.

https://tidbitapp.io/tidbits/trypanosoma-cruzi-reactivation-post-chimeric-antigen-receptor-t-cell-therapy/update.

Lessons (Machine) Learned From COVID-19.

Since coronavirus disease 2019 (COVID-19) first emerged more than 3 years ago, more than 1200 articles have been written describing "lessons learned" from the pandemic. While these articles may contain valuable insights, reading them all would be impossible. A machine learning clustering analysis was therefore performed to obtain an overview of these publications and to highlight the benefits of using machine learning to analyze the vast and ever-growing COVID-19 literature.

Geometry of cold snare polypectomy and risk of incomplete resection.

BACKGROUND: Cold snare polypectomy (CSP) is safer than and equally efficacious as hot snare polypectomy (HSP) for the removal of small (<10mm) colorectal polyps. The maximum polyp size that can be effectively managed by piecemeal CSP (p-CSP) without an excessive burden of recurrence is unknown. METHODS: Resection error risks (RERs), defined as the estimated likelihood of incomplete removal of adenomatous tissue for a single snare resection pass, for CSP and HSP were calculated, based on an incomplete resection rate. Polyp area, snare size, estimated number of resections, and optimal resection defect area were modeled. Overall risk of incomplete resection (RIR) was defined as RIR=1 - (1 - p)n, where p is the RER and n the number of resections. RESULTS: A 40-mm polyp has a four times greater area than a 20-mm polyp (314.16mm2 vs. 1256.64mm2), and requires three times more resections (11 vs. 33, respectively, assuming 8-mm piecemeal resection pieces for p-CSP). RIRs for a 40-mm polyp by HSP and p-CSP were 15.1%-23% and 40.74%-60.60% respectively. CONCLUSION: RER is more important with p-CSP than with HSP. The number of resections, n, and consequently RIR increases with increasing polyp size. Given the overwhelming safety of CSP, specific techniques to minimize the RER should be studied and developed.

Endoscopic resection of large anastomotic polyps is safe and effective.

BACKGROUND: Large (≥20mm) adenomatous anastomotic polyps (LAAPs) are uncommon. Data pertaining to their prevalence, characteristics, and the efficacy of endoscopic resection (ER) are absent. A safe and effective strategy for ER would reduce morbidity and healthcare costs. METHODS: Large nonpedunculated colorectal polyps of ≥20mm (LNPCPs) referred for ER were prospectively studied. Multiple data points were recorded including anastomotic location, polyp morphology, resection modality, complications, and technical success. RESULTS: Over 7 years until November 2022, 2629 lesions were referred. Of these, 10 (0.4%) were LAAPs (median size 35 mm [interquartile range (IQR) 30-40mm]). All LAAPs were removed by piecemeal endoscopic mucosal resection (EMR), most (n=9; 90%) in combination with cold-forceps avulsion with adjuvant snare-tip soft coagulation (CAST). On comparison of the LAAP group with the conventional LNPCP group, CAST was more commonly used (90% vs. 9%; P<0.001) and deep mural injury (DMI) type II was more frequent (40% vs. 11%, P=0.003); however, significant DMI (III-V) did not occur. At 6 month (IQR 5.25-6 months) surveillance, there was no recurrence in any of the 10 cases. There were no serious adverse events. CONCLUSIONS: LAAPs present unique challenges owing to their location overlying an anastomosis. Despite these challenges they can be safely and effectively managed endoscopically without recurrence at endoscopic follow-up.

Direct diverticular peroral endoscopic myotomy for the treatment of thoracic esophageal diverticula: technique and outcomes.

BACKGROUND: Diverticular peroral endoscopic myotomy (POEM) is an alternative to surgery for the management of symptomatic thoracic esophageal diverticula. Conventionally, this requires proximal tunnel formation but a direct approach may simplify the technique. Herein, we report the outcomes of direct diverticular-POEM (DD-POEM). METHODS: We conducted a single-center prospective observational study evaluating DD-POEM. This involved a direct approach to the diverticulum. Success was defined as an Eckardt score of ≤ 3 without the need for reintervention. RESULTS: 10 patients underwent DD-POEM (median age 72 years; interquartile range [IQR] 14.3; male 60 % [n = 6]). Median diverticulum size was 40 mm (IQR 7.5) and median location was 35 cm from the incisors (IQR 8.3). Five patients (50 %) had an underlying dysmotility disorder. The median procedure duration was 60 minutes (IQR 28.8). There were no adverse events. The median hospital stay was 1 day (IQR 0.75). The pre-procedure median Eckardt score of 6 (IQR 4) significantly improved to 0 (IQR 0.75; P < 0.001) at a median follow-up of 14.5 months (IQR 13.8). Success was achieved in all patients. CONCLUSIONS: DD-POEM was a safe technique for the management of thoracic esophageal diverticula. Owing to its simplicity and excellent performance it should be further evaluated for the treatment of this disorder.

Hybrid resection versus conventional resection for laterally spreading lesions of the papilla.

BACKGROUND AND AIMS: Although conventional hot snare resection (CR) of laterally spreading lesions of the major papilla (LSL-Ps) is effective, it can be associated with delayed bleeding in upward of 25% of cases. Given the excellent safety profile of cold snare polypectomy in the colorectum, we investigated the efficacy and safety of a novel hybrid resection (HR) technique for LSL-P management, consisting of hot snare papillectomy plus cold snare resection of the laterally spreading component. METHODS: A prospective cohort of patients underwent HR in a tertiary referral center over 60 months until December 2022. This cohort was compared with a historical cohort of patients who underwent CR at the same institution over 120 months until August 2017. The primary outcomes were recurrence and bleeding. RESULTS: Twenty patients underwent HR (14 female; mean age 65.2 ± 12.2 years). Median lesion size was 30 mm (interquartile range, 25.0-47.5 mm). Recurrent or residual adenoma (RRA) was greater with HR (58.8% [n = 10] vs 29.8% [n = 14]; P = .034). The odds ratio for recurrence was 3.6 times (95% CI, 1.2-11.0) higher with HR (P = .027). RRA was multifocal in 4 (40%) and had a composite RRA volume >10 mm in 7 (70%). The median number of procedures required to treat RRA was higher with HR (4 vs 1, P = .002). There was no difference between CR and HR for intraprocedural bleeding (41.1% [n = 23] vs 25% [n = 5]; P = .587) or delayed bleeding (25.0% vs 10.0%, P = .211). There were no perforations. CONCLUSIONS: The novel HR technique for LSL-P management is associated with a high rate of RRA that is recalcitrant to treatment, without mitigating the risk of intraprocedural or delayed bleeding. Therefore, CR should remain the mainstay management option for treating patients with an LSL-P. (Clinical trial registration number: NCT02306603.).

Adipose cDC1s contribute to obesity-associated inflammation through STING-dependent IL-12 production.

Obesity is associated with chronic low-grade white adipose tissue (WAT) inflammation that can contribute to the development of insulin resistance in mammals. Previous studies have identified interleukin (IL)-12 as a critical upstream regulator of WAT inflammation and metabolic dysfunction during obesity. However, the cell types and mechanisms that initiate WAT IL-12 production remain unclear. Here we show that conventional type 1 dendritic cells (cDC1s) are the cellular source of WAT IL-12 during obesity through analysis of mouse and human WAT single-cell transcriptomic datasets, IL-12 reporter mice and IL-12p70 protein levels by enzyme-linked immunosorbent assay. We demonstrate that cDC1s contribute to obesity-associated inflammation by increasing group 1 innate lymphocyte interferon-γ production and inflammatory macrophage accumulation. Inducible depletion of cDC1s increased WAT insulin sensitivity and systemic glucose tolerance during diet-induced obesity. Mechanistically, endocytosis of apoptotic bodies containing self-DNA by WAT cDC1s drives stimulator of interferon genes (STING)-dependent IL-12 production. Together, these results suggest that WAT cDC1s act as critical regulators of adipose tissue inflammation and metabolic dysfunction during obesity.

Synthesis and evaluation of aromatic BDSF bioisosteres on biofilm formation and colistin sensitivity in pathogenic bacteria.

The diffusible signal factor family (DSF) of molecules play an important role in regulating intercellular communication, or quorum sensing, in several disease-causing bacteria. These messenger molecules, which are comprised of cis-unsaturated fatty acids, are involved in the regulation of biofilm formation, antibiotic tolerance, virulence and the control of bacterial resistance. We have previously demonstrated how olefinic N-acyl sulfonamide bioisosteric analogues of diffusible signal factor can reduce biofilm formation or enhance antibiotic sensitivity in a number of bacterial strains. This work describes the design and synthesis of a second generation of aromatic N-acyl sulfonamide bioisosteres. The impact of these compounds on biofilm production in Acinetobacter baumannii, Escherichia coli, Burkholderia multivorans, Burkholderia cepacia, Burkholderia cenocepacia, Pseudomonas aeruginosa and Stenotrophomonas maltophilia is evaluated, in addition to their effects on antibiotic tolerance. The ability of these molecules to increase survival rates on co-administration with colistin is also investigated using the Galleria infection model.

Regional Anesthesia in Upper-Limb Surgery.

BACKGROUND: Local and regional anesthesia is associated with numerous clinical and institutional advantages relative to general anesthesia. As anesthesiologists and surgeons increasingly integrate local and regional anesthesia into their clinical practice, an understanding of the principles, evolution, and trends underpinning modern anesthetic techniques continues to be relevant. METHODS: A review of the literature in databases Medline, PubMed, and EMBASE identified recent developments, ongoing trends, and historical milestones in upper-limb regional anesthesia. RESULTS: Advances in regional anesthetic techniques in the last century have led to reduced postoperative pain, improved safety, and improved outcomes in upper-limb surgery. The development of ultrasound-guided techniques, as well as pharmacological advances in local anesthetic drugs and adjuncts, has further advanced the role of regional anesthesia. Wide-awake local anesthesia with no tourniquet has allowed certain procedures to be performed on select patients in outpatient and low-resource settings. CONCLUSIONS: This review provides an overview of local and regional anesthesia in the upper-limb from its historical origins to its contemporary applications in upper-limb surgery, particularly during the COVID-19 pandemic.