Novel Use of the Falciform Ligament for MHV Reconstruction During Laparoscopic Hepatectomy of Colorectal Liver Metastasis.

BACKGROUND: Laparoscopic hepatectomy (LH) with oncological R0 resection combined with systemic therapy offers the best chance of cure for colorectal liver metastasis. However, tumors in vicinity of major hepatic veins require complex technique. Parenchyma-sparing resection with involved vein resection and peritoneal patch reconstruction could be an efficacious alternative to preserve liver volume for adjuvant chemotherapy and avoid venous congestion of the remnant liver.1,2 METHODS: A 64-year-old female, with history of colon cancer, had new diagnosis of liver metastatic tumor of S8 (2.8 cm), which was considering encroached on middle hepatic vein (MHV) with distal part patent. Thus margin-negative, parenchyma-sparing liver resection with involved vein resection and proximal MHV reconstruction was indicated for oncological radicality. RESULTS: With the patient in modified French position, we dissected falciform ligament and right coronary ligament to expose the crypt between right hepatic vein (RHV) and MHV. Intraoperative ultrasound localized the tumor and resection margin. Parenchymal dissection was performed caudally to cranially, left to right, to ligate dorsal branch of G8 (G8d) and V8 and expose main trunk of MHV. The involved side-wall of MHV was incised after the proximal and distal parts clamped. Peritoneal patch was harvested from falciform ligament to repair MHV side-wall before clamps released. The patient had an uneventful recovery and remained disease-free at 1 year postoperatively with patency of distal MHV by image. CONCLUSIONS: LH with MHV reconstruction by falciform ligament for metastatic lesion is technically demanding but feasible with oncological radicality and volume preservation for adjuvant chemotherapy.

The Mini Nutritional Assessment combined with body fat for detecting the risk of sarcopenia and sarcopenic obesity in metabolic syndrome.

Malnutrition is a key factor in metabolic syndrome (MS) and sarcopenia, assessing the nutritional status of these patients is a pressing issue. The purpose of this study was to clarify sarcopenia and sarcopenic obesity in patients with MS based on nutritional status. This was a case-control study between MS/non-MS. Body composition was measured by dual-energy X-ray absorptiometry. Muscle function was assessed by handgrip strength, five times sit-to-stand test, gait speed test and short physical performance battery (SPPB). The Mini Nutritional Assessment (MNA) was performed to assess the nutritional status in the participants in this study. Overall, a total of 56 % and 13 % of participants suffered from possible sarcopenia and sarcopenia, respectively. There was a higher rate of possible sarcopenic obesity in the MS group than in the non-MS group (48·9 % v. 24·7 %, P < 0·01), and all the sarcopenia participants in the MS group had sarcopenic obesity. MNA score was significantly associated with sarcopenia status (P < 0·01). The MNA combined with body fat score showed better acceptable discrimination for detecting sarcopenic obesity and sarcopenia in MS (AUC = 0·70, 95 % CI 0·53, 0·86). In summary, there was a higher prevalence of possible sarcopenic obesity in MS, and all the MS patients with sarcopenia had sarcopenic obesity in the present study. We suggest that the MNA should be combined with body fat percentage to assess the nutritional status of MS participants, and it also serves as a good indicator for sarcopenia and sarcopenic obesity in MS.

Novel method for laparoscopic rectus sheath tunneling with Lin's tube in peritoneal dialysis catheter implantation.

Laparoscopic implantation of a catheter through rectus sheath tunnel minimizes the risks of catheter failure and reduces some complications like catheter migration, hernias, and leaks. We described a novel method for laparoscopic catheter rectus sheath tunneling using an aspiration tube and a silk tie (Lin's tube). This material is easily available and yields a small fascial defect with an equivalent cannula size to minimize tissue disruption. The technique is feasible, reproducible and it may reduce the risks of postoperative leakage and hemorrhage.

Mass eradication of Helicobacter pylori to reduce gastric cancer incidence and mortality: a long-term cohort study on Matsu Islands.

OBJECTIVE: Although mass eradication of Helicobacter pylori has been proposed as a means to eliminate gastric cancer, its long-term effects remain unclear. DESIGN: Mass eradication of H. pylori infection was launched in 2004 and continued until 2018 for a high-risk Taiwanese population aged 30 years or older dwelling on Matsu Islands with prevalent H. pylori infection. Test positives for the 13C-urea breath test underwent eradication therapy. We evaluated the effectiveness of the mass eradication in reducing two main outcomes, incidence and mortality rates of gastric cancer, until the end of 2016 and 2018, respectively. RESULTS: After six rounds of mass screening and eradication, the coverage rate reached 85.5% (6512/7616). The referral rate for treatment was 93.5% (4286/4584). The prevalence rates of H. pylori fell from 64.2% to 15.0% with reinfection rates of less than 1% per person-year. The presence and severity of atrophic gastritis and intestinal metaplasia also decreased with time. Compared with the historical control period from 1995 to 2003, the effectiveness in reducing gastric cancer incidence and mortality during the chemoprevention period was 53% (95% CI 30% to 69%, p<0.001) and 25% (95% CI -14% to 51%, p=0.18), respectively. No significant changes were noted in the incidence rates of other digestive tract cancers or the antibiotic resistance rate of H. pylori. CONCLUSION: Population-based eradication of H. pylori has significantly reduced gastric cancer incidence with no increase in the likelihood of adverse consequences. A significant reduction in mortality is likely to be achieved with a longer follow-up period. TRIAL REGISTRATION NUMBER: NCT00155389.

Evaluating medical capacity for hospitalization and intensive care unit of COVID-19: A queue model approach.

BACKGROUND: The surge of COVID-19 pandemic has caused severe respiratory conditions and a large number of deaths due to the shortage of intensive care unit (ICU) in many countries. METHODS: We developed a compartment queue model to describe the process from case confirmation, home-based isolation, hospitalization, ICU, recovery, and death. By using public assessed data in Lombardy, Italy, we estimated two congestion indices for isolation wards and ICU. The excess ICU needs were estimated in Lombardy, Italy, and other countries when data were available, including France, Spain, Belgium, New York State in the USA, South Korea, and Japan. RESULTS: In Lombardy, Italy, the congestion of isolation beds had increased from 2.2 to the peak of 6.0 in March and started to decline to 3.9 as of 9th May, whereas the demand for ICU during the same period has not decreased yet with an increasing trend from 2.9 to 8.0. The results showed the unmet ICU need from the second week in March as of 9th May. The same situation was shown in France, Spain, Belgium, and New York State, USA but not for South Korea and Japan. The results with data until December 2020 for Lombardy, Italy were also estimated to reflect the demand for hospitalization and ICU after the occurrence of viral variants. CONCLUSION: Two congestion indices for isolation wards and ICU beds using open assessed tabulated data with a compartment queue model underpinning were developed to monitor the clinical capacity in hospitals in response to the COVID-19 pandemic.

Probabilistic forecasts of COVID-19 deaths with the progression rate from pneumonia to ARDS: An open-data-based global study.

BACKGROUND: Cumulative data of case-fatality rates (CFR) of COVID-19 varied across countries. A forecasting model generated based on detailed information from three countries during the initial phase of pandemic showed that progression rates from pneumonia to ARDS (PRPA) varied by country and were highly associated with CFR. We aim to elucidate the impact of the PRPA on COVID-19 deaths in different periods of pandemic. METHODS: We used the country-based, real-time global COVID-19 data through GitHub repository to estimate PRPA on the first period (January to June), second period (July to September), and third period (October to December) in 2020. PRPA was used for predicting COVID-19 deaths and assessing the reduction in deaths in subsequent two periods. RESULTS: The estimated PRPA varied widely from 0.38% to 51.36%, with an average of 15.99% in the first period. The PRPA declined to 8.44% and 6.35% in the second and third period. The CFR declined stepwise and was 4.94%, 2.61%, and 1.96%, respectively. Some countries exhibited a decrease in the PRPA from the second to the third period whereas others showed the opposite, particularly where selected viral mutants were prevalent. Overall, the number of observed deaths was lower than that of the predicted deaths in the second and third periods, suggesting an improvement in management of COVID-19 patients. Besides, the degree of improvement depends on the extent of change in PRPA. CONCLUSION: PRPA is a useful indicator to facilitate decision making and assess the improvement of clinical management and medical capacity by forecasting deaths.

Preparation of allyl isothiocyanate nanoparticles, their anti-inflammatory activity towards RAW 264.7 macrophage cells and anti-proliferative effect on HT1376 bladder cancer cells.

BACKGROUND: Allyl isothiocyanate (AITC), a volatile and water-insoluble compound present in several cruciferous vegetables, has been shown to possess several biological qualities such as anti-bacterial, anti-fungal, and anti-cancer activity. In this study, water-soluble allyl isothiocyanate nanoparticles (AITC-NPs) were prepared by oil dispersed in water (O/W) microemulsion and complex coacervation techniques and evaluated for their anti-inflammatory activity towards macrophage cell RAW 264.7 and anti-cancer effect on human bladder cancer cell HT1376. RESULTS: The AITC-NPs with a particle size of 9.4 nm were stable during heating up to 110 °C or three freeze-thawing cycles. No significant cytotoxicity was shown on Caco-2 and intestine epithelial IEC-6 cells at AITC-NP doses ranging from 0.25 to 2 g L-1 (8.75-70 mg L-1 AITC). However, at 2 g L-1 dosage, AITC-NPs could inhibit the growth of human bladder cancer cells HT1376 by 90%, while their low dosage at 0.25 g L-1 could inhibit migration ability by 83.7, 71.3, 58.4 and 31.4% after 4, 8, 12, and 24 h of incubation, respectively. Compared to AITC and NPs, AITC-NPs showed a better inhibition on lipopolysaccharide (LPS)-induced TNF-α, IL-6, NO and iNOS production in RAW 264.7 macrophage cells. CONCLUSION: The results demonstrate the potential of AITC-NPs as therapeutic agents for the treatment of bladder cancer and the enhancement of immune function. © 2018 Society of Chemical Industry.

Structural insights into the catalytic mechanism of human squalene synthase.

Squalene synthase (SQS) is a divalent metal-ion-dependent enzyme that catalyzes the two-step reductive `head-to-head' condensation of two molecules of farnesyl pyrophosphate to form squalene using presqualene diphosphate (PSPP) as an intermediate. In this paper, the structures of human SQS and its mutants in complex with several substrate analogues and intermediates coordinated with Mg2+ or Mn2+ are presented, which stepwise delineate the biosynthetic pathway. Extensive study of the SQS active site has identified several critical residues that are involved in binding reduced nicotinamide dinucleotide phosphate (NADPH). Based on mutagenesis data and a locally closed (JK loop-in) structure observed in the hSQS-(F288L)-PSPP complex, an NADPH-binding model is proposed for SQS. The results identified four major steps (substrate binding, condensation, intermediate formation and translocation) of the ordered sequential mechanisms involved in the `1'-1' isoprenoid biosynthetic pathway. These new findings clarify previous hypotheses based on site-directed mutagenesis and biochemical analysis.

Binding modes of zaragozic acid A to human squalene synthase and staphylococcal dehydrosqualene synthase.

Zaragozic acids (ZAs) belong to a family of fungal metabolites with nanomolar inhibitory activity toward squalene synthase (SQS). The enzyme catalyzes the committed step of sterol synthesis and has attracted attention as a potential target for antilipogenic and antiinfective therapies. Here, we have determined the structure of ZA-A complexed with human SQS. ZA-A binding induces a local conformational change in the substrate binding site, and its C-6 acyl group also extends over to the cofactor binding cavity. In addition, ZA-A effectively inhibits a homologous bacterial enzyme, dehydrosqualene synthase (CrtM), which synthesizes the precursor of staphyloxanthin in Staphylococcus aureus to cope with oxidative stress. Size reduction at Tyr(248) in CrtM further increases the ZA-A binding affinity, and it reveals a similar overall inhibitor binding mode to that of human SQS/ZA-A except for the C-6 acyl group. These structures pave the way for further improving selectivity and development of a new generation of anticholesterolemic and antimicrobial inhibitors.

Nuclear EGFR suppresses ribonuclease activity of polynucleotide phosphorylase through DNAPK-mediated phosphorylation at serine 776.

Nuclear existence of epidermal growth factor receptor (EGFR) has been documented for more than two decades. Resistance of cancer to radiotherapy is frequently correlated with elevated EGFR expression, activity, and nuclear translocation. However, the role of nuclear EGFR (nEGFR) in radioresistance of cancers remains elusive. In the current study, we identified a novel nEGFR-associated protein, polynucleotide phosphorylase (PNPase), which possesses 3' to 5' exoribonuclease activity toward c-MYC mRNA. Knockdown of PNPase increased radioresistance. Inactivation or knock-down of EGFR enhanced PNPase-mediated c-MYC mRNA degradation in breast cancer cells, and also increased its radiosensitivity. Interestingly, the association of nEGFR with PNPase and DNA-dependent protein kinase (DNAPK) increased significantly in breast cancer cells after exposure to ionizing radiation (IR). We also demonstrated that DNAPK phosphorylates PNPase at Ser-776, which is critical for its ribonuclease activity. The phospho-mimetic S776D mutant of PNPase impaired its ribonuclease activity whereas the nonphosphorylatable S776A mutant effectively degraded c-MYC mRNA. Here, we uncovered a novel role of nEGFR in radioresistance, and that is, upon ionizing radiation, nEGFR inactivates the ribonuclease activity of PNPase toward c-MYC mRNA through DNAPK-mediated Ser-776 phosphorylation, leading to increase of c-MYC mRNA, which contributes to radioresistance of cancer cells.

Goldilocks principle of minimally invasive surgery for gastric subepithelial tumors.

BACKGROUND: Minimally invasive surgery had been tailored to individual cases of gastric subepithelial tumors (SETs) after comparing the clinical outcomes of endoscopic resection (ER), laparoscopic resection (LR), and hybrid methods. AIM: To study the use of Goldilocks principle to determine the best form of minimally invasive surgery for gastric SETs. METHODS: In this retrospective study, 194 patients of gastric SETs with high probability of surgical intervention were included. All patients underwent tumor resection in the operating theater between January 2013 and December 2021. The patients were divided into two groups, ER or LR, according to the tumor characteristics and the initial intent of intervention. Few patients in the ER group required further backup laparoscopic surgery after an incomplete ER. The patients who had converted open surgery were excluded. A logistic regression model was used to assess the associations between patient characteristics and the likelihood of a treatment strategy. The area under the curve was used to assess the discriminative ability of tumor size and Youden's index to determine the optimal cut-off tumor size. RESULTS: One-hundred ninety-four patients (100 in the ER group and 94 in the LR group) underwent tumor resection in the operating theater. In the ER group, 27 patients required backup laparoscopic surgery after an incomplete ER. The patients in the ER group had small tumor sizes and shorter procedure durations while the patients in the LR group had large tumor sizes, exophytic growth, malignancy, and tumors that were more often located in the middle or lower third of the stomach. Both groups had similar durations of hospital stays and a similar rate of major postoperative complications. The patients in the ER group who underwent backup surgery required longer procedures (56.4 min) and prolonged stays (2 d) compared to the patients in the LR group without the increased rate of major postoperative complications. The optimal cut-off point for the tumor size for laparoscopic surgery was 2.15 cm. CONCLUSION: Multidisciplinary teamwork leads to the adoption of different strategies to yield efficient clinical outcomes according to the tumor characteristics.

Saline irrigation versus gauze wiping and suction only for peritoneal decontamination during laparoscopic repair for perforated peptic ulcer disease.

The aim of current single-center study was to compare the short-term outcome of suction and gauze wiping alone versus the irrigation and suction technique for peritoneal decontamination among patients who underwent laparoscopic repair of PPU. Using data from our institution's prospectively maintained database, 105 patients who underwent laparoscopic repair were enrolled in this study. The participants were further divided into the group who received peritoneal irrigation (irrigation group, n = 67) and group who received gauze wiping and suction only (suction only group, n = 38). The irrigation group had a longer operative time (140 vs. 113 min, p = 0.0001), higher number of drainage tubes (38.8% vs. 0%, p < 0.0001) and a higher incidence of intra-abdominal abscess (10.4% vs. 0%, p = 0.0469) than the suction only group. Peritoneal irrigation may be associated with a prolonged operative time and a higher number of abdominal drains. Meanwhile, gauze wiping and suction may be sufficient for peritoneal decontamination during the laparoscopic repair of PPU as further infectious complications are not observed.

High-resolution structures of Neotermes koshunensis ß-glucosidase mutants provide insights into the catalytic mechanism and the synthesis of glucoconjugates.

NkBgl, a ß-glucosidase from Neotermes koshunensis, is a ß-retaining glycosyl hydrolase family 1 enzyme that cleaves ß-glucosidic linkages in disaccharide or glucose-substituted molecules. ß-Glucosidases have been widely used in several applications. For example, mutagenesis of the attacking nucleophile in ß-glucosidase has been conducted to convert it into a glycosynthase for the synthesis of oligosaccharides. Here, several high-resolution structures of wild-type or mutated NkBgl in complex with different ligand molecules are reported. In the wild-type NkBgl structures it was found that glucose-like glucosidase inhibitors bind to the glycone-binding pocket, allowing the buffer molecule HEPES to remain in the aglycone-binding pocket. In the crystal structures of NkBgl E193A, E193S and E193D mutants Glu193 not only acts as the catalytic acid/base but also plays an important role in controlling substrate entry and product release. Furthermore, in crystal structures of the NkBgl E193D mutant it was found that new glucoconjugates were generated by the conjugation of glucose (hydrolyzed product) and HEPES/EPPS/opipramol (buffer components). Based on the wild-type and E193D-mutant structures of NkBgl, the glucosidic bond of cellobiose or salicin was hydrolyzed and a new bond was subsequently formed between glucose and HEPES/EPPS/opipramol to generate new glucopyranosidic products through the transglycosylation reaction in the NkBgl E193D mutant. This finding highlights an innovative way to further improve ß-glucosidases for the enzymatic synthesis of oligosaccharides.

Length of Alcohol Abstinence Predicts Posttransplant Delirium in Living Donor Liver Transplant Recipients with Alcoholic Cirrhosis.

OBJECTIVES: History of alcohol abuse is a predictive factor for posttransplant delirium. We aimed to investigate whether preoperative abstinence was associated with posttransplant delirium in liver transplant recipients with alcohol-related cirrhosis. MATERIALS AND METHODS: From January 2014 to December 2019, 84 patients with alcohol-related cirrhosis who received living donor liver transplant were retrospectively reviewed and divided into a delirium group (n = 46, 54.8%) and a nondelirium group (n = 38, 45.2%) using the Richmond Agitation- Sedation Scale and the Confusion Assessment Method for the Intensive Care Unit. RESULTS: In the delirium group versus the nondelirium group, patients were more likely to have preoperative hepatic encephalopathy (58.7% vs 31.6%; P = .013), more likely to have higher Model for End-Stage Liver Disease scores (27.05 ± 10.56 vs 18.85 ± 7.96; P < .001), less likely to have preoperative alcohol abstinence (43.5% vs 68.4%%; P = .022), had longer duration of mechanical ventilation (7.57 ± 7.82 vs 2.50 ± 5.96 days; P = .001), and had longer stays in the intensive care unit (14.85 ± 15.01 vs 8.84 ± 7.84 days; P = .021) and in the hospital (37.89 ± 18.85 vs 27.15 ± 10.43 days; P = .002). Multivariate analysis revealed that preoperative alcohol abstinence (odds ratio 4.953; 95% CI, 1.519-16.152; P = .008) was a significant predictor and that more patients had abstinence durations <3 months (60.9% vs 34.2%; P = .048) in the delirium group. CONCLUSIONS: A high incidence of posttransplant delirium in liver transplant recipients with alcohol- related cirrhosis was associated with preoperative abstinence. Abstinence >6 months before living donor liver transplant is suggested to reduce the risk of posttransplant delirium.

New Surveillance Metrics for Alerting Community-Acquired Outbreaks of Emerging SARS-CoV-2 Variants Using Imported Case Data: Bayesian Markov Chain Monte Carlo Approach.

BACKGROUND: Global transmission from imported cases to domestic cluster infections is often the origin of local community-acquired outbreaks when facing emerging SARS-CoV-2 variants. OBJECTIVE: We aimed to develop new surveillance metrics for alerting emerging community-acquired outbreaks arising from new strains by monitoring the risk of small domestic cluster infections originating from few imported cases of emerging variants. METHODS: We used Taiwanese COVID-19 weekly data on imported cases, domestic cluster infections, and community-acquired outbreaks. The study period included the D614G strain in February 2020, the Alpha and Delta variants of concern (VOCs) in 2021, and the Omicron BA.1 and BA.2 VOCs in April 2022. The number of cases arising from domestic cluster infection caused by imported cases (Dci/Imc) per week was used as the SARS-CoV-2 strain-dependent surveillance metric for alerting local community-acquired outbreaks. Its upper 95% credible interval was used as the alert threshold for guiding the rapid preparedness of containment measures, including nonpharmaceutical interventions (NPIs), testing, and vaccination. The 2 metrics were estimated by using the Bayesian Monte Carlo Markov Chain method underpinning the directed acyclic graphic diagram constructed by the extra-Poisson (random-effect) regression model. The proposed model was also used to assess the most likely week lag of imported cases prior to the current week of domestic cluster infections. RESULTS: A 1-week lag of imported cases prior to the current week of domestic cluster infections was considered optimal. Both metrics of Dci/Imc and the alert threshold varied with SARS-CoV-2 variants and available containment measures. The estimates were 9.54% and 12.59%, respectively, for D614G and increased to 14.14% and 25.10%, respectively, for the Alpha VOC when only NPIs and testing were available. The corresponding figures were 10.01% and 13.32% for the Delta VOC, but reduced to 4.29% and 5.19% for the Omicron VOC when NPIs, testing, and vaccination were available. The rapid preparedness of containment measures guided by the estimated metrics accounted for the lack of community-acquired outbreaks during the D614G period, the early Alpha VOC period, the Delta VOC period, and the Omicron VOC period between BA.1 and BA.2. In contrast, community-acquired outbreaks of the Alpha VOC in mid-May 2021, Omicron BA.1 VOC in January 2022, and Omicron BA.2 VOC from April 2022 onwards, were indicative of the failure to prepare containment measures guided by the alert threshold. CONCLUSIONS: We developed new surveillance metrics for estimating the risk of domestic cluster infections with increasing imported cases and its alert threshold for community-acquired infections varying with emerging SARS-CoV-2 strains and the availability of containment measures. The use of new surveillance metrics is important in the rapid preparedness of containment measures for averting large-scale community-acquired outbreaks arising from emerging imported SARS-CoV-2 variants.

Evaluating correlates of protection for mix-match vaccine against COVID-19 VOCs with potential of evading immunity.

BACKGROUND: In the face of rapid emerging variants of concern (VOCs) with potential of evading immunity from Beta to Omicron and uneven distribution of different vaccine brands, a mix-match strategy has been considered to enhance immunity. However, whether increasing immunogenicity using such a mix-match can lead to high clinical efficacy, particularly when facing Omicron pandemic, still remains elusive without using the traditional phase 3 trial. The aim of this study is to demonstrate how to evaluate correlates of protection (CoP) of the mix-match vaccination. METHODS: Data on neutralizing antibody (NtAb) titers and clinical efficacy against Wuhan or D614G strains of homologous ChAdOx1 nCov-19 or mRNA-1273 and heterologous vaccination were extracted from previous studies for demonstration. The reductions in NtAb titers of homologous vaccination against Beta, Delta, and Omicron variants were obtained from literatures. A Bayesian inversion method was used to derive CoP from homologous to mix-match vaccine. Findings The predicted efficacy of ChAdOx1 nCov-19 and mRNA-1273 for Wuhan or D614G strains was 93 % (89 %-97 %). Given 8 âˆ¼ 11-fold, 2 âˆ¼ 5.5-fold, and 32.5 âˆ¼ 36-fold reduction of NtAb for Beta, Delta, and Omicron variants compared with D614G, the corresponding predictive efficacy of the mix-match ranged from 75.63 % to 73.87 %, 84.87 % to 81.25 %, and 0.067 % to 0.059 %, respectively. Interpretations While ChAdOx1 nCov-19 and mRNA-1273 used for demonstrating how to timely evaluate CoP for the mix-match vaccine still provides clinical efficacy against Beta and Delta VOCs but it appears ineffective for Omicron variants, which highlights the urgent need for next generation vaccine against Omicron variant.

Structural and functional analysis of three ß-glucosidases from bacterium Clostridium cellulovorans, fungus Trichoderma reesei and termite Neotermes koshunensis.

ß-glucosidases (EC 3.2.1.21) cleave ß-glucosidic linkages in disaccharide or glucose-substituted molecules and play important roles in fundamental biological processes. ß-Glucosidases have been widely used in agricultural, biotechnological, industrial and medical applications. In this study, a high yield expression (70-250 mg/l) in Escherichia coli of the three functional ß-glucosidase genes was obtained from the bacterium Clostridium cellulovorans (CcBglA), the fungus Trichoderma reesei (TrBgl2), and the termite Neotermes koshunensis (NkBgl) with the crystal structures of CcBglA, TrBgl2 and NkBgl, determined at 1.9Å, 1.63Å and 1.34Å resolution, respectively. The overall structures of these enzymes are similar to those belonging to the ß-retaining glycosyl hydrolase family 1, which have a classical (α/ß)(8)-TIM barrel fold. Each contains a slot-like active site cleft and a more variable outer opening, related to its function in processing different lengths of ß-1,4-linked glucose derivatives. The two essential glutamate residues for hydrolysis are spatially conserved in the active site. In both TrBgl2 and NkBgl structures, a Tris molecule was found to bind at the active site, explaining the slight inhibition of hydrolase activity observed in Tris buffer. Manganese ions at 10mM exerted an approximate 2-fold enzyme activity enhancement of all three ß-glucosidases, with CcBglA catalyzing the most efficiently in hydrolysis reaction and tolerating Tris as well as some metal inhibition. In summary, our results for the structural and functional properties of these three ß-glucosidases from various biological sources open important avenues of exploration for further practical applications.

Endoscopic Resection for Gastric Subepithelial Tumor with Backup Laparoscopic Surgery: Description of a Single-Center Experience.

The aim of this study was to analyze patients who underwent endoscopic resection (ER) for gastric subepithelial tumors (SETs) with a high probability of surgical intervention. Between January 2013 and January 2021, 83 patients underwent ER at the operation theater and 27 patients (32.5%) required backup surgery mainly due to incidental perforation or uncontrolled bleeding despite endoscopic repairing. The tumor was predominantly located in the upper-third stomach (81%) with a size ≤ 2 cm (69.9%) and deep to the muscularis propria (MP) layer (92.8%) but there were no significant differences between two groups except tumor exophytic growth as a risk factor in the surgery group (37% vs. 0%, p < 0.0001). Patients in the ER-only group had shorter durations of procedure times (60 min vs. 185 min, p < 0.0001) and lengths of stay (5 days vs. 7 days, p < 0.0001) but with a higher percentage of overall morbidity graded III (0% vs. 7.1%, p = 0.1571). After ER, five patients (6%) had delayed perforation and two (2.4%) required emergent laparoscopic surgery. Neither recurrence nor gastric stenosis was reported during long-term surveillance. Here, we provide a minimally invasive strategy of endoscopic resection with backup laparoscopic surgery for gastric SETs.

Evaluating Clinical Efficacy of Antiviral Therapy for COVID-19: A Surrogate Endpoint Approach.

INTRODUCTION: Efficient evaluation with an early surrogate endpoint, taking into account the process of disease evolution, may not only clarify inconsistent or underpowered results but also provide a new insight into the exploration of a new antiviral therapy for treating COVID-19 patients. METHODS: We assessed the dynamics of COVID-19 disease spectrum, commencing from low-risk (no or low oxygen supplement), medium-risk (non-invasive ventilator or high oxygen supplement), and high-risk (extracorporeal membrane oxygenation or invasive ventilator) risk state on enrollment, and then the subsequent progression and regression of risk states until discharge or death. The efficacy of antiviral therapy in altering the dynamics was assessed by using the high-risk state as a surrogate endpoint based on the data retrieved from the two-arm Adaptive Covid-19 Treatment Trial. RESULTS: Using the high-risk state as a surrogate endpoint, remdesivir treatment led to a decrease in the high-risk COVID-19 state by 34.8% (95% CI 26.7-42.0%) for a 14-day period and 29.3% (95% CI 28.8-29.8%) up to 28 days, which were consistent with a statistically significant reduction of death by 30.5% (95% CI 6.6, 50.9%) up to a 28-day period. The estimates of numbers needed to be treated were 100.9 (95% CI 88.1, 115.7) for using the high-risk COVID-19 state as a surrogate endpoint for a 14-day period and 133.3 (95% CI 112.5, 158.0) were required for averting one death from COVID-19 up to 28 days. CONCLUSIONS: We demonstrate the expedient use of the high-risk COVID-19 disease status as a surrogate endpoint for evaluating the primary outcome of the earliest death.