Mechanical release of homogenous proteins from supramolecular gels.

A long-standing challenge is how to formulate proteins and vaccines to retain function during storage and transport and to remove the burdens of cold-chain management. Any solution must be practical to use, with the protein being released or applied using clinically relevant triggers. Advanced biologic therapies are distributed cold, using substantial energy, limiting equitable distribution in low-resource countries and placing responsibility on the user for correct storage and handling. Cold-chain management is the best solution at present for protein transport but requires substantial infrastructure and energy. For example, in research laboratories, a single freezer at -80 °C consumes as much energy per day as a small household1. Of biological (protein or cell) therapies and all vaccines, 75% require cold-chain management; the cost of cold-chain management in clinical trials has increased by about 20% since 2015, reflecting this complexity. Bespoke formulations and excipients are now required, with trehalose2, sucrose or polymers3 widely used, which stabilize proteins by replacing surface water molecules and thereby make denaturation thermodynamically less likely; this has enabled both freeze-dried proteins and frozen proteins. For example, the human papilloma virus vaccine requires aluminium salt adjuvants to function, but these render it unstable against freeze-thaw4, leading to a very complex and expensive supply chain. Other ideas involve ensilication5 and chemical modification of proteins6. In short, protein stabilization is a challenge with no universal solution7,8. Here we designed a stiff hydrogel that stabilizes proteins against thermal denaturation even at 50 °C, and that can, unlike present technologies, deliver pure, excipient-free protein by mechanically releasing it from a syringe. Macromolecules can be loaded at up to 10 wt% without affecting the mechanism of release. This unique stabilization and excipient-free release synergy offers a practical, scalable and versatile solution to enable the low-cost, cold-chain-free and equitable delivery of therapies worldwide.

Cryptosporidium life cycle small molecule probing implicates translational repression and an Apetala 2 transcription factor in macrogamont differentiation.

The apicomplexan parasite Cryptosporidium is a leading cause of childhood diarrhea in developing countries. Current treatment options are inadequate and multiple preclinical compounds are being actively pursued as potential drugs for cryptosporidiosis. Unlike most apicomplexans, Cryptosporidium spp. sequentially replicate asexually and then sexually within a single host to complete their lifecycles. Anti-cryptosporidial compounds are generally identified or tested through in vitro phenotypic assays that only assess the asexual stages. Therefore, compounds that specifically target the sexual stages remain unexplored. In this study, we leveraged the ReFRAME drug repurposing library against a newly devised multi-readout imaging assay to identify small-molecule compounds that modulate macrogamont differentiation and maturation. RNA-seq studies confirmed selective modulation of macrogamont differentiation for 10 identified compounds (9 inhibitors and 1 accelerator). The collective transcriptomic profiles of these compounds indicates that translational repression accompanies Cryptosporidium sexual differentiation, which we validated experimentally. Additionally, cross comparison of the RNA-seq data with promoter sequence analysis for stage-specific genes converged on a key role for an Apetala 2 (AP2) transcription factor (cgd2_3490) in differentiation into macrogamonts. Finally, drug annotation for the ReFRAME hits indicates that an elevated supply of energy equivalence in the host cell is critical for macrogamont formation.

An essential endoplasmic reticulum-resident N-acetyltransferase ortholog in Plasmodium falciparum.

N-terminal acetylation is a common eukaryotic protein modification that involves the addition of an acetyl group to the N-terminus of a polypeptide. This modification is largely performed by cytosolic N-terminal acetyltransferases (NATs). Most associate with the ribosome, acetylating nascent polypeptides co-translationally. In the malaria parasite Plasmodium falciparum, exported effectors are thought to be translated into the endoplasmic reticulum (ER), processed by the aspartic protease plasmepsin V and then N-acetylated, despite having no clear access to cytosolic NATs. Here, we used inducible gene deletion and post-transcriptional knockdown to investigate the primary ER-resident NAT candidate, Pf3D7_1437000. We found that it localizes to the ER and is required for parasite growth. However, depletion of Pf3D7_1437000 had no effect on protein export or acetylation of the exported proteins HRP2 and HRP3. Despite this, Pf3D7_1437000 depletion impedes parasite development within the host red blood cell and prevents parasites from completing genome replication. Thus, this work provides further proof of N-terminal acetylation of secretory system proteins, a process unique to apicomplexan parasites, but strongly discounts a promising candidate for this post-translational modification.

Snare Tip Soft Coagulation vs Argon Plasma Coagulation vs No Margin Treatment After Large Nonpedunculated Colorectal Polyp Resection: a Randomized Trial.

BACKGROUND & AIMS: Thermal treatment of the defect margin after endoscopic mucosal resection (EMR) of large nonpedunculated colorectal lesions reduces the recurrence rate. Both snare tip soft coagulation (STSC) and argon plasma coagulation (APC) have been used for thermal margin treatment, but there are few data directly comparing STSC with APC for this indication. METHODS: We performed a randomized 3-arm trial in 9 US centers comparing STSC with APC with no margin treatment (control) of defects after EMR of colorectal nonpedunculated lesions ≥15 mm. The primary end point was the presence of residual lesion at first follow-up. RESULTS: There were 384 patients and 414 lesions randomized, and 308 patients (80.2%) with 328 lesions completed ≥1 follow-up. The proportion of lesions with residual polyp at first follow-up was 4.6% with STSC, 9.3% with APC, and 21.4% with control subjects (no margin treatment). The odds of residual polyp at first follow-up were lower for STSC and APC when compared with control subjects (P = .001 and P = .01, respectively). The difference in odds was not significant between STSC and APC. STSC took less time to apply than APC (median, 3.35 vs 4.08 minutes; P = .019). Adverse event rates were low, with no difference between arms. CONCLUSIONS: In a randomized trial STSC and APC were each superior to no thermal margin treatment after EMR. STSC was faster to apply than APC. Because STSC also results in lower cost and plastic waste than APC (APC requires an additional device), our study supports STSC as the preferred thermal margin treatment after colorectal EMR. (Clinicaltrials.gov, Number NCT03654209.).

Hybrid Versus Conventional Colorectal Endoscopic Submucosal Dissection: A Multicenter Randomized Controlled Trial (Short-Endoscopic Submucosal Dissection).

INTRODUCTION: Hybrid endoscopic submucosal dissection (H-ESD), which utilizes ESD knife along with snare-based resection, has been developed to overcome the technical complexity of conventional ESD (C-ESD). The aim of this study was to compare the therapeutic outcomes of H-ESD vs C-ESD for nonpedunculated colorectal lesions ≥20 mm in size. METHODS: We conducted a multicenter randomized controlled trial to compare H-ESD and C-ESD (Short-ESD trial). Patients with colorectal lesions between 20 and 50 mm in size were randomly assigned (1:1) to H-ESD or C-ESD. Primary outcome was procedure time/speed. Secondary outcomes were en bloc and complete (R0) resection rates and adverse event rates. RESULTS: A total of 89 patients (median age 63 years; 49.3% women) with the median polyp size of 30 mm underwent H-ESD (n = 40) and C-ESD (n = 49). The mean procedure time of H-ESD was significantly shorter than that of C-ESD (41.1 ± 16.3 vs 54.3 ± 28.2 minutes; P = 0.007). The en bloc and R0 resection rates trended lower in the H-ESD vs C-ESD groups (77.5% vs 87.8%; P = 0.26% and 72.5% vs 79.6%; P = 0.46) without reaching statistical significance. Adverse event rate was similar between H-ESD and C-ESD (10% vs 8.2%; P = 1.00). DISCUSSION: Both H-ESD and C-ESD were safe and effective for resection of large colorectal lesions. H-ESD was associated with a shorter procedure time. H-ESD may represent a viable alternative to C-ESD, with the main advantage being easy applicability of a snare-based technique for colorectal lesions. Future studies are needed to further define the most suitable lesions for H-ESD, as to optimize efficiency and safety without compromising resection outcomes. ClinicaTrials.gov NCT NCT05347446.

Neural mechanisms of emotional health in traumatic brain injury patients undergoing rTMS treatment.

Emotional dysregulation such as that seen in depression, are a long-term consequence of mild traumatic brain injury (TBI), that can be improved by using neuromodulation treatments such as repetitive transcranial magnetic stimulation (rTMS). Previous studies provide insights into the changes in functional connectivity related to general emotional health after the application of rTMS procedures in patients with TBI. However, these studies provide little understanding of the underlying neuronal mechanisms that drive the improvement of the emotional health in these patients. The current study focuses on inferring the effective (causal) connectivity changes and their association with emotional health, after rTMS treatment of cognitive problems in TBI patients (N = 32). Specifically, we used resting state functional magnetic resonance imaging (fMRI) together with spectral dynamic causal model (spDCM) to investigate changes in brain effective connectivity, before and after the application of high frequency (10 Hz) rTMS over left dorsolateral prefrontal cortex. We investigated the effective connectivity of the cortico-limbic network comprised of 11 regions of interest (ROIs) which are part of the default mode, salience, and executive control networks, known to be implicated in emotional processing. The results indicate that overall, among extrinsic connections, the strength of excitatory connections decreased while that of inhibitory connections increased after the neuromodulation. The cardinal region in the analysis was dorsal anterior cingulate cortex (dACC) which is considered to be the most influenced during emotional health disorders. Our findings implicate the altered connectivity of dACC with left anterior insula and medial prefrontal cortex, after the application of rTMS, as a potential neural mechanism underlying improvement of emotional health. Our investigation highlights the importance of these brain regions as treatment targets in emotional processing in TBI.

Intelligent process monitoring of smart polymer composites using large area graphene coated fabric sensor.

Herein, we report the development of an online process monitoring system for vacuum-assisted resin transfer molding (VARTM) process using large area graphene coated in-situ fabric sensor. Besides imparting excellent mechanical properties to the final composites, these sensors provide critical information during the composite processing including detecting defects and evaluating processing parameters. The obtained information can be used to create a digital passport of the manufacturing phase to develop a cost-effective production technique and fabricate high-quality composites.  The fabric sensor was produced using a scalable dip-coating process by coating 1-, 3- or 5-layers of thermally reduced graphene oxide (rGO) onto glass fabric surface according to the number of dips of the fabrics into GO solution. The electrical resistances from all electrode pairs were simultaneously and continuously recorded during distinct stages of the VARTM process to determine the relative conductance. During the vacuum cycle, the range of relative conductance increased with the number of coated rGO layers, with the 5-layer rGO-coated sensor showing the highest conductance range of 16.9 %. Additionally, it was observed that the 5-layer coated sensor showed a consistent decrease in conductance during the infusion phase due to the fluid flow pressure dominating the resin electrical conductivity.

Fixation of the proximal flange of a lumen-apposing metal stent using a through-the-scope endoscopic suturing system to prevent stent migration in single-session EUS-directed transgastric ERCP: a pilot study.

BACKGROUND AND AIMS: With the global obesity pandemic, clinical scenarios requiring urgent ERCP in patients with gastric bypass surgery are on the rise, and single-session EUS-directed transgastric ERCP (SS-EDGE) can effectively address these technical challenges. The aim of this study was to evaluate and describe the safe and effective use of a through-the-scope endoscopic suturing system for anchoring the lumen-apposing metal stents (LAMSs) during SS-EDGE. METHODS: Six patients with Roux-en-Y gastric bypass (RYGB) underwent SS-EDGE at our center. A through-the-scope endoscopic suturing system was used for anchoring the LAMSs during SS-EDGE. RESULTS: Clinical and technical success was achieved in all 6 patients without any adverse events related to the procedure. No stent migration, pneumoperitoneum, or GI perforation was noted. At the 4-week follow-up, no stent migration was noted, and the through-the-scope suturing system remained anchored. LAMSs along with tacks were removed, and gastric fistulae were successfully closed endoscopically in all patients to prevent weight gain. CONCLUSIONS: Use of through-the-scope endoscopic suturing can be a safe, reliable, and potentially cost-effective novel technique for LAMS fixation to successfully perform SS-EDGE in RYGB patients.

The use of a self-assembling peptide gel for stricture prevention in the esophagus after endoscopic submucosal dissection: a U.S. multicenter prospective study (with video).

BACKGROUND AND AIMS: Postoperative stricture is a serious common adverse event after extensive endoscopic submucosal dissection (ESD) in the esophagus. Self-assembling peptide (SAP) gel has been shown to promote tissue healing and re-epithelialization. The aim of this study was to evaluate the effect of the SAP gel for esophageal stricture prevention after ESD. METHODS: This was a multicenter prospective study of patients who underwent esophageal ESD followed by SAP gel application between March 2022 and December 2023. Patients were included if the ESD mucosal defect involved ≥50% of the circumference of the esophagus. High-risk cases were defined as mucosal defects ≥75% of the circumference. Stricture was defined as the inability to pass an endoscope ≥8.9 mm in diameter or a narrow-caliber lumen in a patient with symptoms. RESULTS: A total of 43 patients (median age, 71 years; 81.4% male) underwent ESD (median resected specimen size, 50 mm) during the study period. SAP gel (median, 3 mL) was successfully applied in all cases (median time, 4 minutes). In aggregate, stricture occurred in 20.9% (9 of 43) of the cases. Stricture developed in 30.8% of the high-risk cases: 80% (4 of 5) after circumferential ESD and 19% (4 of 21) in those with defects ≥75% but <100% of the circumference. All cases of stricture resolved with endoscopic treatment. Three cases (6.9%) of postoperative bleeding occurred and were adequately managed endoscopically. CONCLUSIONS: We show that SAP gel application was easy, quick, and associated with a relatively low stricture rate comparable to other prophylactic methods. Additional comparative studies are needed to corroborate these preliminary findings.

Development and initial validation of a video-based peroral endoscopic myotomy assessment tool.

BACKGROUND AND AIMS: Video analysis has emerged as a potential strategy for performance assessment and improvement. We aimed to develop a video-based skill assessment tool for peroral endoscopic myotomy (POEM). METHODS: POEM was deconstructed into basic procedural components through video analysis by an expert panel. A modified Delphi approach and 2 validation exercises were conducted to refine the POEM assessment tool (POEMAT). Twelve assessors used the final POEMAT version to grade 10 videos. Fully crossed generalizability (G) studies investigated the contributions of assessors, endoscopists' performance, and technical elements to reliability. G coefficients below .5 were considered unreliable, between .5 and .7 as modestly reliable, and above .7 as indicative of satisfactory reliability. RESULTS: After task deconstruction, discussions, and the modified Delphi process, the final POEMAT comprised 9 technical elements. G analysis showed low variance for endoscopist performance (.8%-24.9%) and high interrater variability (range, 63.2%-90.1%). The G score was moderately reliable (≥.60) for "submucosal tunneling" and "myotomy" and satisfactorily reliable (≥.70) for "active hemostasis" and "mucosal closure." CONCLUSIONS: We developed and established initial content and response process validity evidence for the POEMAT. Future steps include appraisal of the tool using a wider range of POEM videos to establish and improve the discriminative validity of this tool.

Low delayed bleeding and high complete closure rate of mucosal defects with the novel through-the-scope dual-action tissue clip after endoscopic resection of large nonpedunculated colorectal lesions (with video).

BACKGROUND AND AIMS: Complete closure after endoscopic resection of large nonpedunculated colorectal lesions (LNPCLs) can reduce delayed bleeding but is challenging with conventional through-the-scope (TTS) clips alone. The novel dual-action tissue (DAT) clip has clip arms that open and close independently of each other, facilitating tissue approximation. We aimed to evaluate the rate of complete closure and delayed bleeding with the DAT clip after endoscopic resection of LNPCLs. METHODS: This was a multicenter prospective cohort study of all patients who underwent defect closure with the DAT clip after EMR or endoscopic submucosal dissection (ESD) of LNPCLs ≥20 mm from July 2022 to May 2023. Delayed bleeding was defined as a bleeding event requiring hospitalization, blood transfusion, or any intervention within 30 days after the procedure. Complete closure was defined as apposition of mucosal defect margins without visible submucosal areas <3 mm along the closure line. RESULTS: One hundred seven patients (median age, 64 years; 42.5% women) underwent EMR (n = 63) or ESD (n = 44) of LNPCLs (median size, 40 mm; 74.8% right-sided colon) followed by defect closure. Complete closure was achieved in 96.3% (n = 103) with a mean of 1.4 ± .6 DAT clips and 2.9 ± 1.8 TTS clips. Delayed bleeding occurred in 1 patient (.9%) without requiring additional interventions. CONCLUSIONS: The use of the DAT clip in conjunction with TTS clips achieved high complete defect closure after endoscopic resection of large LNPCLs and was associated with a .9% delayed bleeding rate. Future comparative trials and formal cost-analyses are needed to validate these findings. (Clinical trial registration number: NCT05852457.).

Peroral endoscopic myotomy for spastic esophageal dysmotility among opioid users: a multicenter propensity score matching study.

BACKGROUND AND AIMS: Opioid-induced esophageal dysfunction (OIED) often presents as spastic esophageal disorders (SEDs) and esophagogastric junction outflow obstruction (EGJOO). The aim of this study was to evaluate and compare clinical outcomes of peroral endoscopic myotomy (POEM) for SEDs and EGJOO among opioid users and nonusers. METHODS: This propensity score (PS) matching study included consecutive opioid users and nonusers who underwent POEM for SEDs and EGJOO between January 2018 and September 2022. The following covariates were used for the PS calculation: age, sex, duration of symptoms, Eckardt score, type of motility disorder, and length of myotomy during POEM. Clinical response was defined as a post-POEM Eckardt score ≤3. RESULTS: A total of 277 consecutive patients underwent POEM during the study period. PS matching resulted in the selection of 64 pairs of patients strictly matched 1:1 (n = 128) with no statistically significant differences in demographic, baseline, or procedural characteristics or in the parameters considered for the PS between the 2 groups. Clinical response to POEM was significantly lower among opioid users (51 of 64 [79.7%]) versus nonusers (60 of 64 [93.8%]) (P = .03) at a median follow-up of 18 months. Among opioid users, higher opioid dose (>60 morphine milligram equivalents per day) was associated with a higher likelihood of failure to respond to POEM (odds ratio, 4.59; 95% confidence interval, 1.31-3.98; P = .02). CONCLUSIONS: Clinical response to POEM for SEDs and EGJOO is significantly lower among opioid users versus nonusers. There was a dose-relationship between opioids and response to POEM, with higher daily opioid usage associated with a higher likelihood of treatment failure.

PDZ-binding kinase inhibitor OTS514 suppresses the proliferation of oral squamous carcinoma cells.

OBJECTIVE: PDZ-binding kinase (PBK) has been reported as a poor prognostic factor and is a promising molecular target for anticancer therapeutics. Here, we aimed to investigate the effect of specific PBK inhibitor OTS514 on the survival of OSCC cells. METHODS: Four OSCC cell lines (HSC-2, HSC-3, SAS, and OSC-19) were used to examine the effect of OTS514 on cell survival and apoptosis. DNA microarray analysis was conducted to investigate the effect of OTS514 on gene expression in OSCC cells. Gene set enrichment analysis was performed to identify molecular signatures related to the antiproliferative effect of OTS514. RESULTS: OTS514 decreased the cell survival of OSCC cells dose-dependently, and administration of OTS514 readily suppressed the HSC-2-derived tumor growth in immunodeficient mice. Treatment with OTS514 significantly increased the number of apoptotic cells and caspase-3/7 activity. Importantly, OTS514 suppressed the expression of E2F target genes with a marked decrease in protein levels of E2F1, a transcriptional factor. Moreover, TP53 knockdown attenuated OTS514-induced apoptosis. CONCLUSION: OTS514 suppressed the proliferation of OSCC cells by downregulating the expression of E2F target genes and induced apoptosis by mediating the p53 signaling pathway. These results highlight the clinical application of PBK inhibitors in the development of molecular-targeted therapeutics against OSCC.

BMP pathway regulation of insulin signaling components promotes lipid storage in Caenorhabditis elegans.

A small number of peptide growth factor ligands are used repeatedly in development and homeostasis to drive programs of cell differentiation and function. Cells and tissues must integrate inputs from these diverse signals correctly, while failure to do so leads to pathology, reduced fitness, or death. Previous work using the nematode C. elegans identified an interaction between the bone morphogenetic protein (BMP) and insulin/IGF-1-like signaling (IIS) pathways in the regulation of lipid homeostasis. The molecular components required for this interaction, however, were not fully understood. Here we report that INS-4, one of 40 insulin-like peptides (ILPs), is regulated by BMP signaling to modulate fat accumulation. Furthermore, we find that the IIS transcription factor DAF-16/FoxO, but not SKN-1/Nrf, acts downstream of BMP signaling in lipid homeostasis. Interestingly, BMP activity alters sensitivity of these two transcription factors to IIS-promoted cytoplasmic retention in opposite ways. Finally, we probe the extent of BMP and IIS interactions by testing additional IIS functions including dauer formation, aging, and autophagy induction. Coupled with our previous work and that of other groups, we conclude that BMP and IIS pathways have at least three modes of interaction: independent, epistatic, and antagonistic. The molecular interactions we identify provide new insight into mechanisms of signaling crosstalk and potential therapeutic targets for IIS-related pathologies such as diabetes and metabolic syndrome.

Benefits of EUS-guided gastroenterostomy over surgical gastrojejunostomy in the palliation of malignant gastric outlet obstruction: a large multicenter experience.

BACKGROUND AND AIMS: Palliation of malignant gastric outlet obstruction (mGOO) allows resumption of peroral intake. Although surgical gastrojejunostomy (SGJ) provides durable relief, it may be associated with a higher morbidity, interfere with chemotherapy, and require an optimum nutritional status. EUS-guided gastroenterostomy (EUS-GE) has emerged as a minimally invasive alternative. We aimed to conduct the largest comparative series to date between EUS-GE and SGJ for mGOO. METHODS: This multicenter retrospective study included consecutive patients undergoing SGJ or EUS-GE at 6 centers. Primary outcomes included time to resumption of oral intake, length of stay (LOS), and mortality. Secondary outcomes included technical and clinical success, reintervention rates, adverse events (AEs), and resumption of chemotherapy. RESULTS: A total of 310 patients were included (EUS-GE, n = 187; SGJ, n = 123). EUS-GE exhibited significantly lower time to resumption of oral intake (1.40 vs 4.06 days, P < .001), at lower albumin levels (2.95 vs 3.33 g/dL, P < .001), and a shorter LOS (5.31 vs 8.54 days, P < .001) compared with SGJ; there was no difference in mortality (48.1% vs 50.4%, P = .78). Technical (97.9% and 100%) and clinical (94.1% vs 94.3%) success was similar in the EUS-GE and SGJ groups, respectively. EUS-GE had lower rates of AEs (13.4% vs 33.3%, P < .001) but higher reintervention rates (15.5% vs 1.63%, P < .001). EUS-GE patients exhibited significantly lower interval time to resumption of chemotherapy (16.6 vs 37.8 days, P < .001). Outcomes between the EUS-GE and laparoscopic (n = 46) surgical approach showed that EUS-GE had shorter interval time to initiation/resumption of oral intake (3.49 vs 1.46 days, P < .001), decreased LOS (9 vs 5.31 days, P < .001), and a lower rate of AEs (11.9% vs 17.9%, P = .003). CONCLUSIONS: This is the largest study to date showing that EUS-GE can be performed among nutritionally deficient patients without affecting the technical and clinical success compared with SGJ. EUS-GE is associated with fewer AEs while allowing earlier resumption of diet and chemotherapy.

A novel through-the-scope helix tack-and-suture device for mucosal defect closure following colorectal endoscopic submucosal dissection: a multicenter study.

BACKGROUND: Complete closure of large mucosal defects following colorectal endoscopic submucosal dissection (ESD) with through-the-scope (TTS) clips is oftentimes not possible. We aimed to report our early experience of using a novel TTS suturing system for the closure of large mucosal defects after colorectal ESD. METHODS: We performed a retrospective multicenter cohort study of consecutive patients who underwent attempted prophylactic defect closure using the TTS suturing system after colorectal ESD. The primary outcome was technical success in achieving complete defect closure, defined as a < 5 mm residual mucosal defect in the closure line using TTS suturing, with or without adjuvant TTS clips. RESULTS: 82 patients with a median defect size of 30 (interquartile range 25-40) mm were included. Technical success was achieved in 92.7 % (n = 76): TTS suturing only in 44 patients (53.7 %) and a combination of TTS suturing to approximate the widest segment followed by complete closure with TTS clips in 32 (39.0 %). Incomplete/partial closure, failure of appropriate TTS suture deployment, and the need for over-the-scope salvage closure methods were observed in 7.3 % (n = 6). One intraprocedural bleed, one delayed bleed, and three intraprocedural perforations were observed. There were no adverse events related to placement of the TTS suture. CONCLUSION: The TTS suture system is an effective and safe tool for the closure of large mucosal defects after colorectal ESD and is an alternative when complete closure with TTS clips alone is not possible.

Humoral and T cell responses to SARS-CoV-2 reveal insights into immunity during the early pandemic period in Pakistan.

BACKGROUND: Protection against SARS-CoV-2 is mediated by humoral and T cell responses. Pakistan faced relatively low morbidity and mortality from COVID-19 through the pandemic. To examine the role of prior immunity in the population, we studied IgG antibody response levels, virus neutralizing activity and T cell reactivity to Spike protein in a healthy control group (HG) as compared with COVID-19 cases and individuals from the pre-pandemic period (PP). METHODS: HG and COVID-19 participants were recruited between October 2020 and May 2021. Pre-pandemic sera was collected before 2018. IgG antibodies against Spike and its Receptor Binding Domain (RBD) were determined by ELISA. Virus neutralization activity was determined using a PCR-based micro-neutralization assay. T cell - IFN-γ activation was assessed by ELISpot. RESULTS: Overall, the magnitude of anti-Spike IgG antibody levels as well as seropositivity was greatest in COVID-19 cases (90%) as compared with HG (39.8%) and PP (12.2%). During the study period, Pakistan experienced three COVID-19 waves. We observed that IgG seropositivity to Spike in HG increased from 10.3 to 83.5% during the study, whilst seropositivity to RBD increased from 7.5 to 33.3%. IgG antibodies to Spike and RBD were correlated positively in all three study groups. Virus neutralizing activity was identified in sera of COVID-19, HG and PP. Spike reactive T cells were present in COVID-19, HG and PP groups. Individuals with reactive T cells included those with and without IgG antibodies to Spike. CONCLUSIONS: Antibody and T cell responses to Spike protein in individuals from the pre-pandemic period suggest prior immunity against SARS-CoV-2, most likely from cross-reactive responses. The rising seroprevalence observed in healthy individuals through the pandemic without known COVID-19 may be due to the activation of adaptive immunity from cross-reactive memory B and T cells. This may explain the more favourable COVID-19 outcomes observed in this population.

Correction of a CD55 mutation to quantify the efficiency of targeted knock-in via flow cytometry.

BACKGROUND: Targeted knock-in assisted by the CRISPR/Cas9 system is an advanced technology with promising applications in various research fields including medical and agricultural sciences. However, improvements in the efficiency, precision, and specificity of targeted knock-in are prerequisites to facilitate the practical application of this technology. To improve the efficiency of targeted knock-in, it is necessary to have a molecular system that allows sensitive monitoring of targeted knock-in events with simple procedures. METHODS AND RESULTS: We developed an assay, named CD55 correction assay, with which to monitor CD55 gene correction accomplished by targeted knock-in. To create the reporter clones used in this assay, we initially introduced a 7.7-kb heterozygous deletion covering CD55 exons 2-5, and then incorporated a truncating mutation within exon 4 of the remaining CD55 allele in human cell lines. The resultant reporter clones that lost the CD55 protein on the cell membrane were next transfected with Cas9 constructs along with a donor plasmid carrying wild-type CD55 exon 4. The cells were subsequently stained with fluorescence-labeled CD55 antibody and analyzed by flow cytometry to detect CD55-positive cells. These procedures allow high-throughput, quantitative detection of targeted gene correction events occurring in an endogenous human gene. CONCLUSIONS: The current study demonstrated the utility of the CD55 correction assay to sensitively quantify the efficiency of targeted knock-in. When used with the PIGA correction assay, the CD55 correction assay will help accurately determine the efficiency of targeted knock-in, precluding possible experimental biases caused by cell line-specific and locus-specific factors.

Predicting malignant pleural effusion during diagnostic pleuroscopy with biopsy: A prospective multicentre study.

BACKGROUND AND OBJECTIVE: Pleuroscopy with pleural biopsy has a high sensitivity for malignant pleural effusion (MPE). Because MPEs tend to recur, concurrent diagnosis and treatment of MPE during pleuroscopy is desired. However, proceeding directly to treatment at the time of pleuroscopy requires confidence in the on-site diagnosis. The study's primary objective was to create a predictive model to estimate the probability of MPE during pleuroscopy. METHODS: A prospective observational multicentre cohort study of consecutive patients undergoing pleuroscopy was conducted. We used a logistic regression model to evaluate the probability of MPE with relation to visual assessment, rapid on-site evaluation (ROSE) of touch preparation and presence of pleural nodules/masses on computed tomography (CT). To assess the model's prediction accuracy, a bootstrapped training/testing approach was utilized to estimate the cross-validated area under the receiver operating characteristic curve. RESULTS: Of the 201 patients included in the study, 103 had MPE. Logistic regression showed that higher level of malignancy on visual assessment is associated with higher odds of MPE (OR = 34.68, 95% CI = 9.17-131.14, p < 0.001). The logistic regression also showed that higher level of malignancy on ROSE of touch preparation is associated with higher odds of MPE (OR = 11.63, 95% CI = 3.85-35.16, p < 0.001). Presence of pleural nodules/masses on CT is associated with higher odds of MPE (OR = 6.61, 95% CI = 1.97-22.1, p = 0.002). A multivariable logistic regression model of final pathologic status with relation to visual assessment, ROSE of touch preparation and presence of pleural nodules/masses on CT had a cross-validated AUC of 0.94 (95% CI = 0.91-0.97). CONCLUSION: A prediction model using visual assessment, ROSE of touch preparation and CT scan findings demonstrated excellent predictive accuracy for MPE. Further validation studies are needed to confirm our findings.

Em14-3-3 delivered by PLGA and chitosan nanoparticles conferred improved protection in chicken against Eimeria maxima.

Eimeria maxima (E. maxima) are an intracellular apicomplexan protozoan that causes intestinal coccidiosis in chickens. The purpose of this research was to develop a novel delivery approach for recombinant E. maxima (rEm) 14-3-3 antigen to elicit enhanced immunogenic protection using poly (D, L-lactide-co-glycolide) (PLGA) and chitosan (CS) nanoparticles (NPs) against E. maxima challenge. The morphologies of prepared antigen-loaded NPs (PLGA/CS-rEm14-3-3 NPs) were visualized by a scanning electron microscope. The rEm14-3-3 and PLGA/CS-rEm14-3-3 NPs-immunized chicken-induced changes of serum cytokines, IgY-antibody level, and T-lymphocyte subsets and protective efficacies against E. maxima challenge were evaluated. The results revealed that encapsulated rEm14-3-3 in PLGA and CS NPs presented spherical morphology with a smooth surface. The chickens immunized with only rEm14-3-3 and PLGA/CS-rEm14-3-3 NPs elicited a significant (p<0.05) higher level of IFN-γ cytokine, stimulated the proportions of CD4+/CD3+, CD8+/CD3+ T-cells, and provoked sera IgY-antibody immune response compared to control groups (PBS, pET-32a, PLGA, and CS). Whereas, PLGA-rEm14-3-3 NP-immunized chicken provoked a higher level of IFN- γ production and IgY-antibody response rather than CS-rEm14-3-3 and bare antigen, relatively. The animal experiment results ratified that PLGA-rEm14-3-3 NP-immunized chicken significantly alleviated the relative body weight gain (%), decreased lesion score, and enhanced oocyst decrease ratio compared to CS-rEm14-3-3 NPs and only rEm14-3-3. The anti-coccidial index of the chicken vaccinated with the PLGA-rEm14-3-3 NPs was (180.1) higher than that of the Cs-rEm14-3-3 NPs (167.4) and bare antigen (165.9). Collectively, our statistics approved that PLGA NPs might be an efficient antigen carrier system (Em14-3-3) to act as a nanosubunit vaccine that can improve protective efficacies in chicken against E. maxima challenge.