The Fanconi anemia pathway repairs colibactin-induced DNA interstrand cross-links.

Colibactin is a secondary metabolite produced by bacteria present in the human gut and is implicated in the progression of colorectal cancer and inflammatory bowel disease. This genotoxin alkylates deoxyadenosines on opposite strands of host cell DNA to produce DNA interstrand cross-links (ICLs) that block DNA replication. While cells have evolved multiple mechanisms to resolve ("unhook") ICLs encountered by the replication machinery, little is known about which of these pathways promote resistance to colibactin-induced ICLs. Here, we use Xenopus egg extracts to investigate replication-coupled repair of plasmids engineered to contain site-specific colibactin-ICLs. We show that replication fork stalling at a colibactin-ICL leads to replisome disassembly and activation of the Fanconi anemia ICL repair pathway, which unhooks the colibactin-ICL through nucleolytic incisions. These incisions generate a DNA double-strand break intermediate in one sister chromatid, which can be repaired by homologous recombination, and a monoadduct ("ICL remnant") in the other. Our data indicate that translesion synthesis past the colibactin-ICL remnant depends on Polη and a Polκ-REV1-Polζ polymerase complex. Although translesion synthesis past colibactin-induced DNA damage is frequently error-free, it can introduce T>N point mutations that partially recapitulate the mutation signature associated with colibactin exposure in vivo. Taken together, our work provides a biochemical framework for understanding how cells tolerate a naturally-occurring and clinically-relevant ICL.

Stomata damage, photosynthesis, and transpiration evaluation of aquatic lirium after ultrasound irradiation.

PURPOSE: Evaluate the structural damage and the changes in the photosynthesis and transpiration rates of aquatic lirium leaves caused by ultrasound (US) irradiation in search of environmentally friendly methodologies for the control of this weed. MATERIALS AND METHODS: Aquatic lirium plants were extracted from Xochimilco water canals in Mexico City. A part of the group of plants was selected for irradiation, and the rest formed the control group. The irradiation plants group was exposed to US irradiation of 17 kHz frequency and 30 W × 4 output power for 2 h, at noon and 25 °C room temperature. The structural analysis was done with a MOTICAM 1 digital camera, 800 × 600 pixels, incorporated into the MOTIC PSM-1000 optical microscope and edited with Motic Images Plus 2.0 ML software. The total stomata density and the damaged stomata density were determined by dividing the numbers of total and damaged stomata by the visual field area (67,917 mm2), respectively. The leaves' photosynthesis and transpiration rates were measured using an LI-6400XT Portable Photosynthesis System. RESULTS: Significant damage was observed in the stomata and epidermal cells, finding that the average ratio between the damaged and total stomata densities as a function of time (days) showed an exponential increase described by a Box-Lucas equation with a saturation value near unity and a maximum rate of change of the density of damaged stomata on zero-day (immediately after irradiation), decreasing as the days go by. The transpiration rate showed a sudden increase during the first hour after irradiation, reaching a maximum of 36% of its value before irradiation. It then quickly fell during the next 6 days and more slowly until the 21st day, decreasing 79.9% of its value before irradiation. The photosynthetic rate showed similar behavior with a 37.7% maximum increment and a 73.6% minimum decrease of its value before irradiation. CONCLUSIONS: The results of structural stomata damage on the ultrasound-irradiated aquatic lirium leaves are consistent with an excessive ultrasound stimulation on stomata's mechanical operation by guard cells that produce the measured significant increase of the photosynthetic and transpiration rates during the first hour after irradiation. The initial high evaporation could alter the water potential gradient, with a possible generation of tensions in the xylem that could cause embolism in their conduits. The loss of xylem conductivity or hydraulic failure would be consistent with the observed significant fall in the photosynthesis and transpiration rates of the aquatic lirium leaves after its sudden rise in the first hour after irradiation.

Site-selective chlorination of pyrrolic heterocycles by flavin dependent enzyme PrnC.

Halogenation of pyrrole requires strong electrophilic reagents and often leads to undesired polyhalogenated products. Biocatalytic halogenation is a highly attractive approach given its chemoselectivity and benign reaction conditions. While there are several reports of enzymatic phenol and indole halogenation in organic synthesis, corresponding reports on enzymatic pyrrole halogenation have been lacking. Here we describe the in vitro functional and structural characterization of PrnC, a flavin-dependent halogenase that can act on free-standing pyrroles. Computational modeling and site mutagenesis studies identified three key residues in the catalytic pocket. A moderate resolution map using single-particle cryogenic electron microscopy reveals PrnC to be a dimer. This native PrnC can halogenate a library of structurally diverse pyrrolic heterocycles in a site-selective manner and be applied in the chemoenzymatic synthesis of a chlorinated analog of the agrochemical fungicide Fludioxonil.

Expanding the anti-flaviviral arsenal: Discovery of a baicalein-derived Compound with potent activity against DENV and ZIKV.

With approximately 3.8 billion people at risk of infection in tropical and sub-tropical regions, Dengue ranks among the top ten threats worldwide. Despite the potential for severe disease manifestation and the economic burden it places on endemic countries, there is a lack of approved antiviral agents to effectively treat the infection. Flavonoids, including baicalein, have garnered attention for their antimicrobial properties. In this study, we took a rational and iterative approach to develop a series of baicalein derivatives with improved antiviral activity against Dengue virus (DENV). Compound 11064 emerged as a promising lead candidate, exhibiting antiviral activity against the four DENV serotypes and representative strains of Zika virus (ZIKV) in vitro, with attractive selectivity indices. Mechanistic studies revealed that Compound 11064 did not prevent DENV attachment at the cell surface, nor viral RNA synthesis and viral protein translation. Instead, the drug was found to impair the post-receptor binding entry steps (endocytosis and/or uncoating), as well as the late stage of DENV infection cycle, including virus assembly/maturation and/or exocytosis. The inability to raise DENV resistant mutants, combined with significant antiviral activity against an unrelated RNA virus (Enterovirus-A71) suggested that Compound 11064 targets the host rather than a viral protein, further supporting its broad-spectrum antiviral potential. Overall, Compound 11064 represents a promising antiviral candidate for the treatment of Dengue and Zika.

Use of cryotherapy in the postoperative management of paediatric anterior cruciate ligament reconstruction: a prospective randomised controlled trial.

To investigate the efficacy of cryotherapy in relieving postoperative pain and restoring knee range-of-motion (ROM) after paediatric anterior cruciate ligament reconstruction (ACLR). Patients undergoing primary ACLR were randomised into cryotherapy or non-cryotherapy groups. Those receiving cryotherapy were subjected to a standardised icing protocol. Icing schedules were used to assess compliance. Standard postoperative rehabilitation protocol was followed for both groups. Outcome measurements were visual analogue scale at rest and movement and knee ROM. Patients were assessed on postoperative day 1 (POD1), 1, 4 and 6 weeks. Twenty-one out of 42 patients received cryotherapy. Both groups were similar in demographics, surgical technique and use of intraoperative anaesthesia. Patients in the cryotherapy group reported lower overall mean pain scores throughout the study duration at rest (0.61 ±â€…1.70, 95% CI = 0.23-0.99 vs. 1.06 ±â€…2.03, 95% CI = 0.60-1.53) and on movement (2.19 ±â€…2.68, 95% CI = 1.59-2.79 vs. 3.13 ±â€…2.75, 95% CI = 2.51-3.75; P = 0.032). Knee flexion in the cryotherapy group showed better recovery of knee flexion from week 4 onwards. Improvement of knee flexion from POD1 is statistically significant at week 6 (98.7 ±â€…19.1°, 95% CI = 89.5-107.9 vs. 65.4 ±â€…49.9°, 95% CI = 42.7-88.1; P = 0.010) and overall mean (71.2 ±â€…35.9°, 95% CI = 61.2-81.1 vs. 45.3 ±â€…55.5°, 95% CI = 30.4-60.2; P = 0.005). The cryotherapy group reported statistically significant better degree of overall mean knee extension (1.2 ±â€…3.3°, 95% CI = 0.5-2.0 vs. 2.6 ±â€…4.6°, 95% CI = 1.6-3.7; P = 0.032). The use of cryotherapy in postoperative ACLR recovery in paediatrics is a simple yet effective measure resulting in short-term pain relief and improvement in knee flexion.

Presenting characteristics, histological subtypes and outcomes of adult central nervous system tumours: retrospective review of a surgical cohort.

Introduction: The most recent local study on the incidence of histological subtypes of all brain and spinal tumours treated surgically was published in 2000. In view of the outdated data, we investigated the presenting characteristics, histological subtypes and outcomes of adult patients who underwent surgery for brain or spinal tumours at our institution. Methods: A single-centre retrospective review of 501 patients who underwent surgery for brain or spinal tumours from 2016 to 2020 was conducted. The inclusion criteria were (a) patients who had a brain or spinal tumour that was histologically verified and (b) patients who were aged 18 years and above at the time of surgery. Results: Four hundred and thirty-five patients (86.8%) had brain tumours and 66 patients (13.2%) had spinal tumours. Patients with brain tumours frequently presented with cranial nerve palsy, headache and weakness, while patients with spinal tumours frequently presented with weakness, numbness and back pain. Overall, the most common histological types of brain and spinal tumours were metastases, meningiomas and tumours of the sellar region. The most common complications after surgery were cerebrospinal fluid leak, diabetes insipidus and urinary tract infection. In addition, 15.2% of the brain tumours and 13.6% of the spinal tumours recurred, while 25.7% of patients with brain tumours and 18.2% of patients with spinal tumours died. High-grade gliomas and metastases had the poorest survival and highest recurrence rates. Conclusion: This study serves as a comprehensive update of the epidemiology of brain and spinal tumours and could help guide further studies on brain and spinal tumours.

Microwave-assisted extraction of bioactive compounds from Sarawak Liberica sp. coffee pulp: Statistical optimization and comparison with conventional methods.

Coffea liberica, commonly known as Liberica coffee, is a kind of coffee that originated in Liberia, a West African country. It is considered a less-known coffee bean variety, which accounts for less than 2% of commercially produced coffee worldwide. In this study, the influences of optimization of microwave-assisted extraction (MAE) on the total phenolic content (TPC), total flavonoid content (TFC), and total carbohydrate content (TCC) of bioactive compounds extracted from Sarawak Liberica sp. coffee pulp were studied. Response surface methodology was adopted with a face-centered central composite design to generate 34 responses by taking three microwave parameters into consideration, microwave power (watt), time of irradiation (second), and solvent-to-feed ratio as independent variables. As a result, the findings revealed that optimum extraction conditions were conducted as follows: microwave power of 700 W, time of irradiation of 180 s, and solvent-to-feed ratio of 86.644:1. While under optimal extraction conditions, MAE outperformed conventional maceration extraction in terms of extraction efficiency and had no significant difference (p < .05) with Soxhlet extraction on the extraction of TPC (12.94 ± 2.25 mg GAE/g), TFC (9.84 ± 0.38 mg QE/g), and TCC (876.50 ± 64.15 mg GE/g). Present work advances the usage of Sarawak Liberica sp. coffee for the development of functional products and aids in reducing environmental pollution by utilization of coffee pulp waste.

Both Adjustable and Fixed Loop Hamstring Tendon Graft Fixation Have Similar Clinical and Patient-Reported Outcomes in Anterior Cruciate Ligament Reconstruction.

Purpose: This study aims to compare the outcomes of fixed-loop device (FLD) vs adjustable-loop device (ALD) graft fixation with up to 2-year follow-up in patients undergoing primary anterior cruciate ligament reconstruction (ACLR) in a predominantly Asian setting. Methods: Prospectively collected outcome measures as well as clinical records of patients who underwent primary ACLR using either FLD or ALD fixation of hamstring tendon autograft performed by a single surgeon were reviewed. The surgeon in this study used a fixed-loop device from 2018 to 2019 and then changed to adjustable loop from 2019 to 2020. Suspensory fixation was performed on the femoral side, and aperture (interference screw) fixation was performed on the tibial side. Outcome measures included knee range of motion, KT-1000 arthrometer testing, Lysholm knee score, and Tegner activity scale. Patients were assessed preoperatively and postoperatively at regular intervals of 6, 12, and 24 months. Results: A total of 105 patients were identified. Forty-six were excluded due to incomplete follow-up data, so 59 patients with full 2-year follow-up were included in the final study group. Both groups (FLD vs ALD) were similar in demographics except for age (P = .042). Out of 105, there were 59 patients remaining in the study group with 2-year follow-up data. No significant differences were observed between the 2 groups at all respective testing intervals. Conclusions: FLDs and ALDs for suspensory fixation of hamstring tendon autograft in ACLR had similar clinical outcomes with a minimum of 2-year follow up. There is no evidence of graft loosening from loop lengthening. Level of Evidence: Level III, retrospective comparative trial.

Further Characterization of Fungal Halogenase RadH and Its Homologs.

RadH is one of the flavin-dependent halogenases that has previously exhibited promising catalytic activity towards hydroxycoumarin, hydroxyisoquinoline, and phenolic derivatives. Here, we evaluated new functional homologs of RadH and expanded its specificities for the halogenation of non-tryptophan-derived, heterocyclic scaffolds. Our investigation revealed that RadH could effectively halogenate hydroxyquinoline and hydroxybenzothiophene. Assay optimization studies revealed the need to balance the various co-factor concentrations and where a GDHi co-factor recycling system most significantly improves the conversion and efficiency of the reaction. A crystal structure of RadH was also obtained with a resolution of 2.4 Å, and docking studies were conducted to pinpoint the binding and catalytic sites for substrates.

Comprehensive molecular phenotyping of ARID1A-deficient gastric cancer reveals pervasive epigenomic reprogramming and therapeutic opportunities.

OBJECTIVE: Gastric cancer (GC) is a leading cause of cancer mortality, with ARID1A being the second most frequently mutated driver gene in GC. We sought to decipher ARID1A-specific GC regulatory networks and examine therapeutic vulnerabilities arising from ARID1A loss. DESIGN: Genomic profiling of GC patients including a Singapore cohort (>200 patients) was performed to derive mutational signatures of ARID1A inactivation across molecular subtypes. Single-cell transcriptomic profiles of ARID1A-mutated GCs were analysed to examine tumour microenvironmental changes arising from ARID1A loss. Genome-wide ARID1A binding and chromatin profiles (H3K27ac, H3K4me3, H3K4me1, ATAC-seq) were generated to identify gastric-specific epigenetic landscapes regulated by ARID1A. Distinct cancer hallmarks of ARID1A-mutated GCs were converged at the genomic, single-cell and epigenomic level, and targeted by pharmacological inhibition. RESULTS: We observed prevalent ARID1A inactivation across GC molecular subtypes, with distinct mutational signatures and linked to a NFKB-driven proinflammatory tumour microenvironment. ARID1A-depletion caused loss of H3K27ac activation signals at ARID1A-occupied distal enhancers, but unexpectedly gain of H3K27ac at ARID1A-occupied promoters in genes such as NFKB1 and NFKB2. Promoter activation in ARID1A-mutated GCs was associated with enhanced gene expression, increased BRD4 binding, and reduced HDAC1 and CTCF occupancy. Combined targeting of promoter activation and tumour inflammation via bromodomain and NFKB inhibitors confirmed therapeutic synergy specific to ARID1A-genomic status. CONCLUSION: Our results suggest a therapeutic strategy for ARID1A-mutated GCs targeting both tumour-intrinsic (BRD4-assocatiated promoter activation) and extrinsic (NFKB immunomodulation) cancer phenotypes.

Weber Ankle Fracture Classification System Yields Greatest Interobserver and Intraobserver Reliability Over AO/OTA and Lauge-Hansen Classification Systems Under Time Constraints in an Asian Population.

No previous studies have evaluated the intra- and interobserver reliability between the Weber, Lauge-Hansen and AO Foundation/Orthopaedic Trauma Association (AO/OTA) classification systems under time constraints. This study compares the interobserver and intraobserver reliability of the aforementioned classification systems under simulated time constraints. Anteroposterior and lateral radiographs of ankle malleolar fractures from 80 consecutive patients from 2015 to 2016 were classified by 2 independent observers according to Weber, Lauge-Hansen and AO/OTA. Classifications were conducted over 4 successive weeks under timed (25-seconds) and untimed conditions, with 1-week gaps between each classification. Cohen's kappa and percentage agreement were calculated. Cohen's kappa for interobserver agreement ranged 0.67 to 0.67 and 0.59 to 0.73 for untimed and timed classifications for Weber; 0.38 to 0.47 and 0.44 to 0.50 for Lauge-Hansen; 0.28 to 0.49 and 0.13 to 0.37 for AO/OTA. Intraobserver agreement ranged from 0.83 to 0.85 and 0.78 to 0.79 for untimed and timed classifications for Weber; 0.46 to 0.65 and 0.59 to 0.73 for Lauge-Hansen; 0.42 to 0.63 and 0.40 to 0.51 for AO/OTA. Based on the Landis and Koch's benchmark scale, there was substantial agreement in the inter- and intraobserver variables for Weber; moderate agreement in inter- and intraobserver variables for Lauge-Hansen; fair and moderate agreement in inter- and intraobserver variables respectively for AO/OTA. Interobserver and intraobserver reliability was the most substantial for Weber, followed by Lauge-Hansen and AO/OTA. Time constraint did not have a statistically significant effect on the reliability of classifications. We recommend concurrent usage of the Weber and Lauge-Hansen system, since they demonstrate the greatest reliability and reproducibility, and confer better understanding of the fracture type, respectively.

Efficient recall of SARS-CoV-2 variant-reactive B cells and T responses in the elderly upon heterologous mRNA vaccines as boosters.

Waning antibody levels against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the emergence of variants of concern highlight the need for booster vaccinations. This is particularly important for the elderly population, who are at a higher risk of developing severe coronavirus disease 2019 (COVID-19) disease. While studies have shown increased antibody responses following booster vaccination, understanding the changes in T and B cell compartments induced by a third vaccine dose remains limited. We analyzed the humoral and cellular responses in subjects who received either a homologous messenger RNA(mRNA) booster vaccine (BNT162b2 + BNT162b2 + BNT162b2; ''BBB") or a heterologous mRNA booster vaccine (BNT162b2 + BNT162b2 + mRNA-1273; ''BBM") at Day 0 (prebooster), Day 7, and Day 28 (postbooster). Compared with BBB, elderly individuals (≥60 years old) who received the BBM vaccination regimen display higher levels of neutralizing antibodies against the Wuhan and Delta strains along with a higher boost in immunoglobulin G memory B cells, particularly against the Omicron variant. Circulating T helper type 1(Th1), Th2, Th17, and T follicular helper responses were also increased in elderly individuals given the BBM regimen. While mRNA vaccines increase antibody, T cell, and B cell responses against SARS-CoV-2 1 month after receiving the third dose booster, the efficacy of the booster vaccine strategies may vary depending on age group and regimen combination.

Lower vaccine-acquired immunity in the elderly population following two-dose BNT162b2 vaccination is alleviated by a third vaccine dose.

Understanding the impact of age on vaccinations is essential for the design and delivery of vaccines against SARS-CoV-2. Here, we present findings from a comprehensive analysis of multiple compartments of the memory immune response in 312 individuals vaccinated with the BNT162b2 SARS-CoV-2 mRNA vaccine. Two vaccine doses induce high antibody and T cell responses in most individuals. However, antibody recognition of the Spike protein of the Delta and Omicron variants is less efficient than that of the ancestral Wuhan strain. Age-stratified analyses identify a group of low antibody responders where individuals ≥60 years are overrepresented. Waning of the antibody and cellular responses is observed in 30% of the vaccinees after 6 months. However, age does not influence the waning of these responses. Taken together, while individuals ≥60 years old take longer to acquire vaccine-induced immunity, they develop more sustained acquired immunity at 6 months post-vaccination. A third dose strongly boosts the low antibody responses in the older individuals against the ancestral Wuhan strain, Delta and Omicron variants.

Heterologous booster vaccination with CoronaVac following prime vaccination with mRNA vaccine.

Objective: Despite the high vaccine efficacy of mRNA COVID-19 vaccines, there are individuals who developed excessive reactogenic and/or allergic responses after the first mRNA dose and were considered ineligible for further mRNA doses. CoronaVac, an inactivated SARS-CoV-2 vaccine, is recommended in Singapore as an alternative. Methods: Individuals, ineligible for further mRNA vaccines (BNT162b2 or mRNA-1273) because of excessive reactive responses to prime mRNA vaccination, were recruited and offered two doses of CoronaVac as booster vaccination 38-224 days post their mRNA vaccine dose. Individuals who did not develop any excessive reactive responses after the prime mRNA vaccination were also recruited and given another mRNA vaccine as booster vaccination. Blood samples were collected at days 0, 21 and 90 post first CoronaVac dose and mRNA dose, respectively, for analysis. Results: We showed that two CoronaVac booster doses induced specific immunity in these mRNA vaccine-primed individuals. Although the spike-specific antibody response was lower, their memory B cell response against the receptor-binding domain (RBD) of the spike protein was similar, compared with individuals who received two BNT162b2 injections. The spike-specific memory T cell response also increased following CoronaVac booster doses. However, specific immunity against the Omicron variant was low, similar to individuals with two BNT162b2 doses. Conclusion: Our findings showed that while mRNA vaccine-primed individuals can opt for two subsequent doses of CoronaVac, an additional dose may be necessary to achieve protection, especially against newly emerging immune escape variants such as Omicron.

Radiofrequency Ablation Versus Repeat Hepatectomy for Recurrent Hepatocellular Carcinoma: A Systematic Review and Meta-Analysis.

BACKGROUND: An updated systematic review and meta-analysis was conducted to compare radiofrequency ablation (RFA) versus repeat hepatectomy (RH) for patients with recurrent hepatocellular carcinoma (rHCC) after a previous liver resection. METHODS: PubMed, EMBASE, and Cochrane databases were searched from inception to October 2021 for randomized controlled trials and propensity-score matched studies. Individual participant survival data of disease-free survival (DFS) and overall survival (OS) were extracted and reconstructed followed by one-stage and two-stage meta-analysis. Secondary outcomes were major complications and length of hospital stay (LOHS). RESULTS: A total of seven studies (1317 patients) were analysed. In both one-stage and two-stage meta-analysis, there was no significant difference in OS between the RFA and RH cohorts (Hazard Ratio (HR) 1.15, 95% CI 0.98-1.36, P = 0.094 and HR 1.12, 95% CI 0.77-1.64, P = 0.474 respectively), while the RFA group had a higher hazard rate of disease recurrence compared to the RH group (HR 1.30, 95% CI 1.13-1.50, P < 0.001 and HR 1.31, 95% CI 1.09-1.57, P = 0.013, respectively). RFA was associated with fewer major complications and shorter LOHS versus RH (Odds Ratio 0.34, 95% CI 0.15-0.76, P = 0.009 and Weighted Mean Difference - 4.78, 95% CI - 6.30 to - 3.26, P < 0.001, respectively). CONCLUSIONS: RH may be associated with superior DFS for rHCC, at the expense of higher morbidity rate and longer LOHS. However, OS is comparable between both modalities. As such, these techniques may be utilized as complementary strategies depending on individual patient and disease factors. Large-scale, randomized, prospective studies are required to corroborate these findings.

Rapid microfluidic platform for screening and enrichment of cells secreting virus neutralizing antibodies.

As part of the body's immune response, antibodies (Abs) have the ability to neutralize pathogenic viruses to prevent infection. To screen for neutralizing Abs (nAbs) from the immune repertoire, multiple screening techniques have been developed. However, conventional methods have a trade-off between screening throughput and the ability to screen for nAbs via their functional efficacy. Although droplet microfluidic platforms have the ability to bridge this disparity, the majority of such reported platforms still rely on Ab-binding assays as a proxy for function, which results in irrelevant hits. Herein, we report the multi-module Droplet-based Platform for Effective Antibody RetrievaL (DROP-PEARL) platform, which can achieve high-throughput enrichment of Ab-secreting cells (ASCs) based on the neutralizing activity of secreted nAbs against the a target virus. In this study, in-droplet Chikungunya virus (CHIKV) infection of host cells and neutralization was demonstrated via sequential delivery of viruses and host cells via picoinjection. In addition, we demonstrate the ability of the sorting system to accurately discriminate and isolate uninfected droplets from a mixed population of droplets at a rate of 150 000 cells per hour. As a proof of concept, a single-cell neutralization assay was performed on two populations of cells (nAb-producing and non-Ab producing cells), and up to 2.75-fold enrichment of ASCs was demonstrated. Finally, we demonstrated that DROP-PEARL is able to achieve similar enrichment for low frequency (∼2%) functional nAb-producing cells in a background of excess cells secreting irrelevant antibodies, highlighting its potential prospect as a first round enrichment platform for functional ASCs. We envision that the DROP-PEARL platform could potentially be used to accelerate the discovery of nAbs against other pathogenic viral targets, and we believe it will be a useful in the ongoing fight against biological threats.

Forecasting the rate of hand injuries in Singapore.

PURPOSE: This study aims to analyse the correlation between the incidence rate of hand injuries and various major economic indicators in Singapore. We hypothesise that the number of hand injuries is correlated to activity in the construction and manufacturing industries in Singapore. METHODS: Twenty thousand seven hundred sixty-four patients who underwent hand surgeries in a tertiary institution between 2012 to 2018 were reviewed. Two independent, blinded observers extracted the frequency of hand surgeries performed from Electronic Medical Records. Economic indicators pertinent to Singapore's economic activity were collected and smoothed by simple moving average of the prior 3 months. Results were analysed using IBM SPSS v25.0. RESULTS: Significant independent univariate variables were Purchasing-Manager-Index and Industrial-Production-Index. Multiple linear regression of quarterly reported figures showed that Total-Livestock-Slaughtered, Total-Seafood-Handled, Purchasing-Manger-Index, Industrial-Production-Index, Gas-Tariffs, Construction-Index, Consumer-Price-Index, Total-Air-Cargo-Handled, Total-Container-Throughput, Total-Road-Traffic-Accident-Casualties, Food-&-Beverage-Services-Index were significantly correlated (p < 0.05) with hand injuries, with R2 = 62.3%. CONCLUSION: Quarterly economic indicators from major economic industries can be used to predict the incidence of hand injuries with a 62.3% correlation. These findings may be useful for anticipating healthcare resource allocation to treat hand injuries. TYPE OF STUDY AND LEVEL OF EVIDENCE: Economic and decision, Level II.

The bacterial toxin colibactin triggers prophage induction.

Colibactin is a chemically unstable small-molecule genotoxin that is produced by several different bacteria, including members of the human gut microbiome1,2. Although the biological activity of colibactin has been extensively investigated in mammalian systems3, little is known about its effects on other microorganisms. Here we show that colibactin targets bacteria that contain prophages, and induces lytic development through the bacterial SOS response. DNA, added exogenously, protects bacteria from colibactin, as does expressing a colibactin resistance protein (ClbS) in non-colibactin-producing cells. The prophage-inducing effects that we observe apply broadly across different phage-bacteria systems and in complex communities. Finally, we identify bacteria that have colibactin resistance genes but lack colibactin biosynthetic genes. Many of these bacteria are infected with predicted prophages, and we show that the expression of their ClbS homologues provides immunity from colibactin-triggered induction. Our study reveals a mechanism by which colibactin production could affect microbiomes and highlights a role for microbial natural products in influencing population-level events such as phage outbreaks.