Plasma campesterol and ABCG5/ABCG8 gene loci on the risk of cholelithiasis and cholecystitis: evidence from Mendelian randomization and colocalization analyses.

The causal relationships between plasma metabolites and cholelithiasis/cholecystitis risks remain elusive. Using two-sample Mendelian randomization, we found that genetic proxied plasma campesterol level showed negative correlation with the risk of both cholelithiasis and cholecystitis. Furthermore, the increased risk of cholelithiasis is correlating with the increased level of plasma campesterol. Lastly, genetic colocalization study showed that the leading SNP, rs4299376, which residing at the ABCG5/ABCG8 gene loci, was shared by plasma campesterol level and cholelithiasis, indicating that the aberrant transportation of plant sterol/cholesterol from the blood stream to the bile duct/gut lumen might be the key in preventing cholesterol gallstone formation.

Fine mapping of TFL, a major gene regulating fruit length in snake gourd (Trichosanthes anguina L).

Fruit length is a crucial agronomic trait of snake gourd (Trichosanthes anguina L); however, genes associated with fruit length have not been characterised. In this study, F2 snake gourd populations were generated by crossing the inbred lines, S1 and S2 (fruit lengths: 110 and 20 cm, respectively). Subsequently, bulk segregant analysis, sequencing, and fine-mapping were performed on the F2 population to identify target genes. Our findings suggest that the fruit length of snake gourd is regulated by a major-effect regulatory gene. Mining of genes regulating fruit length in snake gourd to provide a basis for subsequent selection and breeding of new varieties. Genotype-phenotype association analysis was performed on the segregating F2 population comprising 6,000 plants; the results indicate that the target gene is located on Chr4 (61,846,126-61,865,087 bp, 18.9-kb interval), which only carries the annotated candidate gene, Tan0010544 (designated TFL). TFL belongs to the MADS-box family, one of the largest transcription factor families. Sequence analysis revealed a non-synonymous mutation of base C to G at position 202 in the coding sequence of TFL, resulting in the substitution of amino acid Gln to Glu at position 68 in the protein sequence. Subsequently, an InDel marker was developed to aid the marker-assisted selection of TFL. The TFL in the expression parents within the same period was analysed using quantitative real-time PCR; the TFL expression was significantly higher in short fruits than long fruits. Therefore, TFL can be a candidate gene for determining the fruit length in snake gourd. Collectively, these findings improve our understanding of the genetic components associated with fruit length in snake gourds, which could aid the development of enhanced breeding strategies for plant species.

Consistent efficacy outcomes between phase 2 and phase 3 trials in Crohn's disease or ulcerative colitis in adults: a meta-analysis.

INTRODUCTION: The approval of novel biologic agents and small molecules for the treatment of Crohn's disease (CD) and ulcerative colitis (UC) is dependent on phase 3 randomized controlled trials (RCTs). However, these trials sometimes fail to achieve the expected efficacy outcomes observed in phase 2 trials. METHODS: We conducted a systematic review of RCTs that evaluated biologic agents and small molecules using paired regimens in both phase 2 and phase 3. We searched Medline, EMBASE, and Cochrane databases up until February 13, 2024. The revised Cochrane tool was utilized to assess the risk of bias. A generalized linear mixed-effects model (GLMM) was employed to estimate the odds ratios (ORs) for efficacy outcomes in phase 2 trials compared to phase 3. RESULTS: We identified a total of 23 trials with 10 paired regimens for CD and 30 trials with 11 paired regimens for UC. The GLMM analysis revealed that phase 2 CD trials had higher outcomes measured by the Crohn's Disease Activity Index (CDAI) by 9-13% without statistical significance: CDAI-150: OR, 1.12 (95% CI 0.83-1.51, p = 0.41); CDAI-100: OR, 1.09 (95% CI 0.88-1.35, p = 0.40); or CDAI-70: OR, 1.13 (95% CI 0.61-2.08, p = 0.66). For UC, two efficacy outcomes were estimated to be equally reported in phase 2/phase 3 pairs: clinical remission: OR, 1.00 (95% CI 0.83-1.20, p = 0.96); endoscopic improvement: OR, 0.98 (95% CI 0.83-1.15, p = 0.79). However, the rate of clinical response was underestimated in phase 2 by 19%: OR, 0.81 (95% CI 0.70-0.95, p = 0.03). The inclusion criterion for the type of Mayo score for UC had a significant interaction with the study phase to influence the difference in clinical response (p = 0.002). CONCLUSIONS: Our findings suggest that the main efficacy outcomes for CD and UC remain consistent between phase 2 and phase 3 trials, except for UC response rates. The efficacy data obtained from phase 2 trials can be considered reliable for the design of subsequent phase 3 trials. REGISTRATION: PROSPERO (CRD42023407947).

Preoperative H. pylori Eradication Therapy Facilitates Precise Delineation in Early Gastric Cancer with Current H. pylori Infection.

INTRODUCTION: Early gastric cancer with current Helicobacter pylori infection (HpC-EGC) is common, but it is still unclear whether H. pylori eradication therapy (Hp-ET) or endoscopic submucosal dissection (ESD) should be performed first. We evaluated Hp-ETs short-term effects on horizontal boundary delineations of HpC-EGC in ESD. METHODS: Prospectively enrolled HpC-EGC patients were randomly assigned to eradication or control groups. Operation scopes of HpC-EGC lesions were delineated with marking dots at 5 mm out of the endoscopic demarcation line by an independent endoscopist, unaware of eradication status, before formal circumferential incision. As representatives, precise delineation rate, the shortest distance of all marking dots to the pathological demarcation line in all slices of one intact resected specimen (Dmin), and negative marking dot specimen rate were examined. RESULTS: Twenty-three HpC-EGC patients (25 lesions) were allocated to eradication group and 26 patients (27 lesions) were allocated to the control group with similar eradication success rates and all were differentiated type. With improving background mucosa inflammation after Hp-ET and similar gastritis-like epithelium rates, 10 lesions (40.0%) in the eradication group were of precise delineation compared to control group with 2 lesions (7.4%) (relative risk = 5.40, 95% CI 1.31-22.28). Dmin of eradication and control groups were 4.17 ± 2.52 mm and 2.67 ± 2.30 mm (p = 0.029), accompanied by 4 (14.8%) and none (0.0%) specimens that exhibited positive marking dots (p = 0.11), respectively. CONCLUSION: For HpC-EGC patients, administrating eradication medication before ESD is beneficial for the precise delineation of lesions and reducing the risk of positive horizontal resection margins.

Endoscopic ultrasound-guided tissue acquisition with or without rapid on-site evaluation for solid pancreatic lesions: five years of experience from a single center.

BACKGROUND: Endoscopic ultrasound (EUS)-guided tissue acquisition (TA) by EUS-guided fine needle aspiration (FNA) or fine needle biopsy (FNB) is a standard diagnostic procedure for solid pancreatic lesions. Whether rapid on-site evaluation (ROSE) should be used to support EUS-TA remains controversial. Here we assessed the diagnostic performance of EUS-TA with or without self-ROSE for solid pancreatic masses. METHODS: Three hundred and seventy EUS-TA cases with self-ROSE and 244 cases without ROSE were retrospectively enrolled between August 2018 and June 2022. All procedures including ROSE were performed by the attending endoscopist. Clinical data, EUS characteristics, and diagnostic performance for distinguishing benign from malignant solid pancreatic masses including accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were compared between groups. RESULTS: Self-ROSE improved the diagnostic accuracy of solid pancreatic lesions by 16.7% in the EUS-TA group (p < 0.001) and by 18.9% in the EUS-FNA alone group (p < 0.001). Self-ROSE also improved the diagnostic sensitivity by 18.6% in the EUS-TA group (p < 0.001) and by 21.2% in the EUS-FNA alone group (p < 0.001). Improvements in the diagnostic accuracy by self-ROSE in the EUS-FNB group were not significant. 2.2 ± 0.7, 2.4 ± 0.9, 2.3 ± 0.7, 2.5 ± 0.9, 2.1 ± 0.6, and 2.1 ± 0.7 needle passes were required in the EUS-TA, EUS-FNA, and EUS-FNB with or without self-ROSE groups, respectively. CONCLUSIONS: Self-ROSE significantly improved the accuracy and sensitivity of EUS-FNA alone and EUS-TA diagnosis of solid pancreatic lesions and helped to reduce needle passes during the procedure. Whether self-ROSE benefits EUS-FNB and whether EUS-FNB alone is comparable to EUS-FNA with self-ROSE require further clarification.

One Fluorophore-Two Sensing Films: Hydrogen-Bond Directed Formation of a Quadruple Perylene Bisimide Stack.

Elaborately designed π-stacked molecular aggregates are significant for modulation of photophysical properties of polycyclic aromatic hydrocarbons (PAHs). Herein, a double hydrogen-bonds trussed di(pyridyl)pyrrole-perylene bisimide (HDPP-PBI) was designed and its dimerization behavior was studied. HDPP-PBI tends to form a quadruple PBI stack with a dimerization constant of ∼5.56×106  M-1 . The dimerization was ascribed to synergistic intramolecular double hydrogen-bonds formation and intermolecular π-π stacking. Addition of CF3 COOH, a hydrogen bond blocker, promotes the dimer to monomer transition. Accordingly, two distinct fluorescent films were prepared by drop-casting of the dimerized or the monomeric HDPP-PBI onto a substrate surface. Interestingly, the less-emissive PBI quadruple stack-based film showed a turn on response to acetone vapor, while the highly emissive HDPP-PBI-based film exhibited fluorescence quenching upon exposure to triethylamine vapor. We believe that the discovered synergistic effect in the PBI aggregates would enlighten the design of new PAHs aggregates with defined structures.

Biliary inflammation scoring for immunoglobulin G4-related sclerosing cholangitis: an endoscopic approach with endoscopic ultrasound.

BACKGROUND AND AIMS: The differential diagnosis of immunoglobulin G4-related sclerosing cholangitis (IgG4-SC) and cholangiocarcinoma (CC) remains a clinical challenge. Imaging modalities play critical roles in the diagnosis of IgG4-SC. The present study aimed to evaluate the differential diagnosis of IgG4-SC and CC based on images of endoscopic ultrasound (EUS). METHODS: The biliary inflammation scoring (BIS) method for EUS was developed based on the comparison between images of IgG4-SC and that of cholangiocarcinoma (CC) and other acute or chronic cholangitis. In the BIS diagnostic phase, the EUS images from 66 IgG4-SC patients and 44 CC patients were blindly evaluated using the BIS methods. RESULTS: The sensitivity, specificity, and accuracy of the newly established BIS in distinguishing IgG4-SC from CC were 86% [95% confidence interval (CI) 75-93%], 95% (95% CI 83-99%), and 90% (95% CI 83-94%), respectively. CONCLUSION: EUS should be considered to be added to the workup algorithm in patients with suspected IgG4-SC as a useful diagnostic procedure. BIS is a promising diagnostic method to discriminate IgG4-SC during the ongoing endoscopy.

Gastrointestinal endoscopy infection control strategy during COVID-19 pandemic: Experience from a tertiary medical center in China.

OBJECTIVES: Coronavirus disease 2019 (COVID-19) has spread globally and become a pandemic. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) not only infects the gastrointestinal (GI) tract and causes GI symptoms, but also increases nosocomial transmission risk during endoscopic procedures for aerosol generation. We hereby share our infection control strategies aiming to minimize COVID-19 transmission in the endoscopy center. METHODS: We established our infection control strategies based on the guidance of Chinese Society of Digestive Endoscopy and inputs from hospital infection control experts: admission control through the procedure and patient triage, environmental control to reduce possible virus exposure, proper usage of personal protective equipment (PPE), and scope disinfection and room decontamination. All endoscopic procedures accomplished during COVID-19 outbreak and progress of stepwise resumption of elective endoscopy procedures were retrospectively reviewed. RESULTS: Only urgent or semi-urgent procedures were performed during COVID-19 outbreak. After no local new-onset COVID-19 case in Beijing for four weeks, we reopened the endoscopy center for elective procedures and monitored the outbreak continuously while maintaining a sustainable endoscopy service. CONCLUSIONS: It is imperative that all endoscopy centers should establish standard infection control strategies in order to fight COVID-19 pandemic based on national guidance and academic society guidelines and tailor them to individual resources. These measures and setup can also be reserved for future pandemics.

Endoscopic ultrasound-guided tissue acquisition with or without macroscopic on-site evaluation: randomized controlled trial.

BACKGROUND: The use of macroscopic on-site evaluation (MOSE) to estimate the adequacy of a specimen for histological diagnosis during endoscopic ultrasound (EUS)-guided fine-needle tissue acquisition (FNTA) has recently been advocated. This study aimed to evaluate the diagnostic yield of MOSE compared with conventional EUS-FNTA without rapid on-site evaluation (ROSE). METHODS: This was an international, multicenter, prospective, randomized controlled study. After providing informed consent, consecutive adult patients referred for EUS-FNTA for solid lesions larger than 2 cm were randomized to a MOSE arm or to a conventional arm without ROSE. A designated cytopathologist from each center performed all cytopathological examinations for that center and was blinded to the randomization results. The primary outcome measure was the diagnostic yield, and the secondary outcomes included sensitivity, specificity, positive predictive value, negative predictive value, diagnostic accuracy, and the rate of procedure-related complications. RESULTS: 244 patients (122 conventional, 122 MOSE) were enrolled during the study period. No significant differences between the two arms were found in procedure time or rate of procedure-related adverse events. The diagnostic yield for the MOSE technique (92.6 %) was similar to that for the conventional technique (89.3 %; P  = 0.37), with significantly fewer passes made (median: conventional 3, MOSE 2; P  < 0.001). CONCLUSIONS: EUS-FNTA with the MOSE technique provided a similar diagnostic yield to conventional EUS-FNTA technique in the absence of ROSE but with fewer passes. This technique can be used when ROSE is not available.

Perylene Bisimide and Naphthyl-Based Molecular Dyads: Hydrogen Bonds Driving Co-planarization and Anomalous Temperature-Response Fluorescence.

The origin of the positive temperature effect in fluorescence emission of a newly designed perylene bisimide (PBI) derivative with two naphthyl units containing ortho-methoxy group (NM) at its bay positions (PBI-2NM) was elucidated. A key point is the finding of a weak hydrogen bond (<5.0 kcal mol-1 ) between the methoxy group of the NM unit and a nearby hydrogen atom of the PBI core. It is the bonding that drives co-planarization of the different aromatic units, resulting in delocalization of the π-electrons of the compound as synthesized, inducing fluorescence quenching via intramolecular charge transfer (ICT). With increasing temperature, the co-planar structure could be distorted in part, resulting in a decreased degree of ICT, and hence leading to enhanced fluorescence emission. The unique positive temperature effect in emission induced by H-bond-driven co-planarization may pave a new avenue in designing functional molecular systems complementary to conventional methods.

Identification of Natural Compound Radicicol as a Potent FTO Inhibitor.

The fat mass and obesity-associated protein (FTO), as an m6A demethylase, is involved in many human diseases. Virtual screening and similarity search in combination with bioactivity assay lead to the identification of the natural compound radicicol as a potent FTO inhibitor, which exhibits a dose-dependent inhibition of FTO demethylation activity with an IC50 value of 16.04 µM. Further ITC experiments show that the binding between radicicol and FTO was mainly entropy-driven. Crystal structure analysis reveals that radicicol adopts an L-shaped conformation in the FTO binding site and occupies the same position as N-CDPCB, a previously identified small molecular inhibitor of FTO. Unexpectedly, however, the 1,3-diol group conserved in radicicol and N-CDPCB assumes strikingly different orientations for interaction with FTO. The identification of radicicol as an FTO inhibitor and revelation of its recognition mechanism not only opens the possibility of developing new therapeutic strategies for treatment of leukemia but also provide clues for elucidation of the acting mechanisms of radicicol, which is a possible clinical candidate worth in-depth study.

Model to identify early-stage gastric cancers with deep invasion of submucosa based on endoscopy and endoscopic ultrasonography findings.

BACKGROUND: Conventional endoscopy and endoscopic ultrasonography (EUS) are used to estimate the invasion depth of early-stage gastric cancers (EGCs), but estimates made by either technique are often inaccurate. We developed a model to determine the invasion depth of EGCs using conventional endoscopy and EUS findings, with pathology results as the reference. METHODS: We performed a retrospective study of 195 patients (205 lesions) diagnosed with gastric cancers who underwent endoscopy and EUS followed by resection. Based on pathology analyses, lesions (n = 205) were assigned to categories of: mucosa invasion or minute invasion into the submucosal layer less than 500 µm from the muscularis mucosae (M-SM1) or penetration of 500 µm or more (≥SM2). The lesions were randomly assigned to derivation (138 lesions) and validation sets (67 lesions). A depth predictive model was proposed in the derivation set using multivariate logistic regression analyses. The discriminative power of this model was assessed in both sets. RESULTS: Remarkable redness (OR 5.42; 95% CI 1.32-22.29), abrupt cutting of converging folds (OR 8.58; 95% CI 1.65-44.72), lesions location in the upper third of the stomach (OR 10.26; 95% CI 2.19-48.09), and deep invasion based on EUS findings (OR 16.53; 95% CI 4.48-61.15) significantly associated with ≥SM2 invasion. A model that incorporated these 4 variables discriminated between M-SM1 and ≥SM2 lesions with the area under the ROC curve of 0.865 in the derivation set and 0.797 in the validation set. In the derivation set, a cut-off score of 8 identified lesions as ≥SM2 with 54% sensitivity and 97% specificity. The model correctly predicted the invasion depth 89.86% of lesions; it overestimated the depth of 2.17% of lesions. CONCLUSIONS: We developed a model to identify EGCs with invasion depth ≥SM2 based on endoscopy and EUS findings. This model might reduce overestimation of gastric tumor depth and prevent unnecessary gastrectomy.

Influence of the Ring Size on the Binding Ability of FTO Investigated by Fluorescence Spectroscopy.

The fat mass and obesity associated protein (FTO) is a potential target for anti-obesity medicines. In this paper, we have synthesized two potential inhibitors for FTO, three-member-ring compound (W 3 ) and four-member-ring compound (W 4 ). The interactions of fat mass and obesity-associated (FTO) protein with W 3 (or W 4 ) have been studied by spectral method. Results show the intrinsic fluorescence is quenched by the W 3 (or W 4 ). The thermodynamics parameters indicate hydrophobic interaction play a major role in the interactions. The results of synchronous fluorescence spectra demonstrate that the microenvironments of Trp residue of FTO are disturbed by W 3 and W 4 . Results showed that W 3 are stronger quenchers and bind to FTO with the higher affinity than W 4 . The influence of molecular structure on the binding aspects has been investigated.

Evaluation of novel immediate-/controlled-release tablets of isosorbide-5-mononitrate (5-ISMN): in vitro-in vivo correlation.

The aim of the present study was to develop the novel immediate-controlled release (ICR) tablets of isosorbide-5-mononitrate (5-ISMN) composed of an osmotic pump tablet core coated with an immediate-release layer. The novel ICR tablets of 5-ISMN could release drug quickly and continuously through a semi-permeable membrane (SPM) composed of ethylcellulose (EC)/polyethylene glycol (PEG) 4000 and cellulose acetate (CA)/PEG4000. Release tended to decrease with storage time. However, the drug release rates changed little for the SPM composed of EC/PVP K30. The weight loss test also confirmed these results. The major release mechanism was diffusion according to the Higuchi equation. The relative bioavailability of the ICR tablets compared to the reference formulation in the single and multiple dose regiments were 90.9 and 111.2%, respectively. They were both bioequivalent to the reference formulation. In vitro-in vivo correlation (IVIVC) studies demonstrated that the dissolution in vitro simulated the absorption in vivo well. In general, 5-ISMN ICR tablets composed of an osmotic pump tablet core and an immediate-release layer may be promising in providing immediate and constant drug delivery with minimum fluctuations during long storage time.

[An analysis of results of the elderly colorectal cancer screening study].

OBJECTIVE: To evaluate the detection rates of colorectal polyps and cancer in the elderly and characterize the pathological features of the colorectal neoplasm in DongLi District in Tianjin. METHOD: Totally, 46 743 subjects aged 60-74 were recruited from the national colorectal cancer screening program, including subjects registered from November 2012 to April 2013 in DongLi District in Tianjin. Each subject completed a questionnaire and a fecal occult blood test. Colonoscopies were conducted in 434 subjects with high risk for colorectal cancer. RESULTS: Among all the subjects, 2 880 were at high risk for colorectal cancer which accounts for 6.16% (2 880/46 743) of the total subjects. Among the subjects who underwent the colonoscopy, 165 (men: 105, women: 60) were colorectal polyps accounting for 5.73% (165/2 880) in the total risk, with 51 subjects (1.77%) advanced neoplasms and 4 subjects (0.14%) cancer. The detection rates of colorectal polyps is 0.35% (165/46 743), and colorectal cancer is 8.6/10(5) (4/46 743). More polyps were found on the left colon compared with the right. More tubular adenoma was found compared with the other pathological types. Most of the polyps were smaller than 0.5 cm. Colorectal polyps and advanced neoplasms were more frequent in men than women [45.45% (105/231) vs 29.56% (60/203), 16.02% (37/231) vs 6.90% (14/203), all P < 0.01]. Multiple polyps (P < 0.05) and polyps with diameter larger than 1.0 cm (P < 0.01) were more often in men than in women. Men tended to have more colorectal polyps in right colon and higher detection rate for moderate or sever atypical hyperplasia than women (all P < 0.05). CONCLUSION: There is a higher incidence of colorectal polyps in the elderly. It is important to establish the national sequential colorectal cancer screening program for the early diagnoses of colorectal polyps and cancer in the elderly.

A case report of refractory amebic colitis and literature review.

RATIONALE: Amebic colitis has been less prevalent in recent times in China, and the similarity of its symptoms to those of inflammatory bowel disease (IBD) results in the difficulty of early identification and diagnosis. PATIENT CONCERNS: A 31-year-old male who exhibited intermittent diarrhea and hematochezia was highly suspected as IBD initially. Despite the partial relief of symptoms following the administration of mesalamine, the endoscopic ulcers remained largely unchanged. DIAGNOSES: Two years after the onset of mesalamine therapy, amebic cysts were detected in stool microscopy and trophozoites were found on the surface of cecal ulcers. The patient was then diagnosed with amebic colitis. INTERVENTIONS: After 2 rounds of standardized metronidazole treatment, amebic colitis remained refractory until diloxanide was administered. OUTCOMES: The patient remained asymptomatic, and the mucosa of colon was normal during the annual follow-up. LESSONS: Individuals newly diagnosed with IBD should undergo essential screening for amebiasis. And the use of steroids should be taken with caution, especially in cases where the effect of mesalamine is limited. For symptomatic intestinal amebiasis, even after the administration of tissue amebicides, the continued use of luminal amebicides is necessary to prevent recurrence.

Blue light-mediated gene expression as a promising strategy to reduce antibiotic resistance in Escherichia coli.

The discovery of antibiotics has noticeably promoted the development of human civilization; however, antibiotic resistance in bacteria caused by abusing and overusing greatly challenges human health and food safety. Considering the worsening situation, it is an urgent demand to develop emerging nontraditional technologies or methods to address this issue. With the expanding of synthetic biology, optogenetics exhibits a tempting prospect for precisely regulating gene expression in many fields. Consequently, it is attractive to employ optogenetics to reduce the risk of antibiotic resistance. Here, a blue light-controllable gene expression system was established in Escherichia coli based on a photosensitive DNA-binding protein (EL222). Further, this strategy was successfully applied to repress the expression of ß-lactamase gene (bla) using blue light illumination, resulting a dramatic reduction of ampicillin resistance in engineered E. coli. Moreover, blue light was utilized to induce the expression of the mechanosensitive channel of large conductance (MscL), triumphantly leading to the increase of streptomycin susceptibility in engineered E. coli. Finally, the increased susceptibility of ampicillin and streptomycin was simultaneously induced by blue light in the same E. coli cell, revealing the excellent potential of this strategy in controlling multidrug-resistant (MDR) bacteria. As a proof of concept, our work demonstrates that light can be used as an alternative tool to prolong the use period of common antibiotics without developing new antibiotics. And this novel strategy based on optogenetics shows a promising foreground to combat antibiotic resistance in the future.

Engineering a Lactobacillus Lysine Riboswitch to Dynamically Control Metabolic Pathways for Lysine Production in Corynebacterium glutamicum.

Knock-out of genes of metabolic pathways is conventionally used in the metabolic engineering of microorganisms, but it is not applicable for genes of essential pathways. In order to avoid undesirable effects caused by gene deletion, it is attractive to develop riboswitches to dynamically control the metabolic pathways of microbial cell factories. In this regard, the aim of this study is to utilize the lysine riboswitch to control gene expressions of the biosynthetic pathways and by-pathways and thus improve lysine production in Corynebacterium glutamicum. To achieve this, a natural lysine riboswitch from Lactobacillus plantarum (LPRS) was first detected and then fused with RFP to test its functionality. After that, engineered lysine-activated (Lys-A) and lysine-repressed (Lys-R) riboswitches were successfully screened by dual genetic selection. Furthermore, the optimized A263 and R152 were applied to control the expression of aspartate kinase III and homoserine dehydrogenase in the lysine-producing strain C. glutamicum QW45, respectively. In contrast with QW45, the growth of the resulting A263-lysC mutant QW48 was similar to that of QW45; however, the growth of the resulting R357-hom mutant QW54 was slightly inhibited, indicating an inhibition of threonine biosynthesis caused by the riboswitch upon binding of intracellular lysine. Importantly, the lysine production of QW48 and QW54 was, respectively, 35% and 43% higher than that of the parent strain QW45, implying more metabolic flux directed into the lysine synthesis pathway. Finally, the engineered A263 and R357 were simultaneously applied to the same mutant QW55, which greatly improved lysine production. Thus, the approach demonstrated in this work could be principally used as a powerful tool to dynamically control any other undesired metabolic pathways.

Fragility index analysis for randomized controlled trials of approved biologicals and small molecule drugs in inflammatory bowel diseases.

INTRODUCTION: Biologics and small molecules have been increasingly applied in Crohn's disease (CD) and ulcerative colitis (UC). But the robustness of their trials has not been evaluated. METHODS: We initially collected all the approved biologics or small molecules for CD or UC up to December 1, 2022. Databases were then queried by keywords in chemical name and CD or UC. Randomized controlled trials (RCTs) in the two-arm, 1:1 design were included. Fragility index (FI) and fragility quotient (FQ) were subsequently calculated. RESULTS: We included twenty-eight RCTs, including nine pivotal trials listed in approval labels, nineteen non-pivotal trials not included in the labels. The median sample size was 99 [IQR, 60-262] and the median number of loss-of-follow-up (LFU) was 14 [IQR, 8-43]. Pivotal trials in the labels had the median FI of 8 [IQR, 4-14, n = 6] that was marginally higher than non-pivotal trials (3 [IQR, 2-4], p = 0.08). The median FQ was 0.0330 [IQR, 0.1220-0.0466] and 0.0310 [IQR, 0.0129-0.0540] for pivotal and non-pivotal trials, respectively (p = 1.0). The sample size and FI were significantly correlated (Spearman correlation coefficient [r] = 0.56, 95 %CI 0.21-0.78, p = 0.003). The number of total events was also significantly correlated with FI (r = 0.53, 95 %CI 0.17-0.77, p = 0.006). Study p-values were significantly associated with FI (p = 0.01): trials with p-values < 0.001 had the highest median FI of 10 [IQR, 6-17]. No factor was found strongly correlated with FQ. CONCLUSION: Results from trials assessing administration-approved biologics or small molecules for treating CD or UC were vulnerable to small changes by measuring FI or FQ. Pivotal studies contributing to regulatory approvals exhibited a relatively higher degree of resilience compared to non-pivotal trials.