Clinical applications of circulating tumor DNA in hematological malignancies: From past to the future.

Liquid biopsy, particularly circulating tumor DNA (ctDNA), has drawn a lot of attention as a non- or minimal-invasive detection approach for clinical applications in patients with cancer. Many hematological malignancies are well suited for serial and repeated ctDNA surveillance due to relatively high ctDNA concentrations and high loads of tumor-specific genetic and epigenetic abnormalities. Progress of detecting technology in recent years has improved sensitivity and specificity significantly, thus broadening and strengthening the potential utilities of ctDNA including early diagnosis, prognosis estimation, treatment response evaluation, minimal residual disease monitoring, targeted therapy selection, and immunotherapy surveillance. This manuscript reviews the detection methodologies, clinical application and future challenges of ctDNA in hematological malignancies, especially for lymphomas, myeloma and leukemias.

An automatic classification method of testicular histopathology based on SC-YOLO framework.

The pathological diagnosis and treatment of azoospermia depend on precise identification of spermatogenic cells. Traditional methods are time-consuming and highly subjective due to complexity of Johnsen score, posing challenges for accurately diagnosing azoospermia. Here, we introduce a novel SC-YOLO framework for automating the classification of spermatogenic cells that integrates S3Ghost module, CoordAtt module and DCNv2 module, effectively capturing texture and shape features of spermatogenic cells while reducing model parameters. Furthermore, we propose a simplified Johnsen score criteria to expedite the diagnostic process. Our SC-YOLO framework presents the higher efficiency and accuracy of deep learning technology in spermatogenic cell recognition. Future research endeavors will focus on optimizing the model's performance and exploring its potential for clinical applications.

YOLO framework was optimized as SC-YOLO and applied to shape detection for automatic classification of spermatogenic cells in testicular pathology images.The SC-YOLO framework has high accuracy in identifying results from binomial distributions, with or without haploid germ cells.The SC-YOLO framework also has good performance in the identification of other types of pathological sections.

Epidemiology, pathogenesis, clinical characteristics, and treatment of mucormycosis: a review.

AIM: This review aims to summarize the epidemiology, etiology, pathogenesis, clinical manifestations, and current diagnostic and therapeutic approaches for mucormycosis. The goal is to improve understanding of mucormycosis and promote early diagnosis and treatment to reduce mortality. METHODS: A comprehensive literature review was conducted, focusing on recent studies and data on mucormycosis. The review includes an analysis of the disease's epidemiology, etiology, and pathogenesis, as well as current diagnostic techniques and therapeutic strategies. RESULTS: Mucormycosis is increasingly prevalent due to the growing immunocompromised population, the COVID-19 pandemic, and advances in detection methods. The pathogenesis is closely associated with the host immune status, serum-free iron levels, and the virulence of Mucorales. However, the absence of typical clinical manifestations complicates diagnosis, leading to missed or delayed diagnoses and higher mortality. CONCLUSION: An enhanced understanding of the epidemiology, pathogenesis, and clinical presentation of mucormycosis, along with the adoption of improved diagnostic and therapeutic approaches, is essential for reducing mortality rates associated with this opportunistic fungal infection. Early diagnosis and prompt treatment are critical to improving patient outcomes.

The incidence of mucormycosis has increased following the COVID-19 pandemic.The presence of the halo sign and reverse halo sign may indicate the onset of pulmonary mucormycosis.Early implementation of molecular diagnostic methods, such as mNGS and qPCR, may improve the early diagnosis rate of mucormycosis.Isavuconazole and posaconazole can also be considered as first-line treatments for the initial management of mucormycosis.

A biomimetic human disease model of bacterial keratitis using a cornea-on-a-chip system.

Bacterial keratitis is a common form of inflammation caused by the bacterial invasion of the corneal stroma after trauma. In extreme cases, it can lead to severe visual impairment or even blindness; therefore, timely medical intervention is imperative. Unfortunately, widespread misuse of antibiotics has led to the development of drug resistance. In recent years, organ-on-chips that integrate multiple cell co-cultures have extensive applications in fundamental research and drug screening. In this study, immortalized human corneal epithelial cells and primary human corneal fibroblasts were co-cultured on a porous polydimethylsiloxane membrane to create a cornea-on-a-chip model. The developed multilayer epithelium closely mimicked clinical conditions, demonstrating high structural resemblance and repeatability. By introducing a consistently defective epithelium and bacterial infection using the space-occupying method, we successfully established an in vitro model of bacterial keratitis using S. aureus. We validate this model by evaluating the efficacy of antibiotics, such as levofloxacin, tobramycin, and chloramphenicol, through simultaneously observing the reactions of bacteria and the two cell types to these antibiotics. Our study has revealed the barrier function of epithelium of the model and differentiated efficacy of three drugs in terms of bactericidal activity, reducing cellular apoptosis, and mitigating scar formation. Altogether, the cornea on chip enables the assessment of ocular antibiotics, distinguishing the impact on corneal cells and structural integrity. This study introduced a biomimetic in vitro disease model to evaluate drug efficacy and provided significant insights into the extensive effects of antibiotics on diverse cell populations within the cornea.

Isolation and Diverse Reactivity of an Unsymmetrical 1,2-Bis(silylene)-Stabilized Pentacarbonyl Chromium(0) Species.

The construction of the unsymmetrical 1,2-bis(silylene) pentacarbonyl chromium(0) complex 1 was achieved through the reaction of chlorosilylene with half an equivalent of K2Cr(CO)5. X-ray diffraction analysis of 1 confirms the formation of the Si-Si bond and the coordination of one of the silicon atoms to the Cr center. Density functional theory (DFT) calculations disclose that highest occupied molecular orbital (HOMO) mainly corresponds to the lone pair of electrons on the silicon atom and the σ-bonding interaction between two Si atoms. Based on its unique electronic structure, its diverse reactivity toward the transition metal compounds and small molecules was investigated in detail. The reactions of 1 with Fe2(CO)9 or CuCl yielded the 1,2-bis(silylene)-stabilized heterobimetallic complex 2 or oxidized product 3, respectively. Additionally, treatments of 1 with selenium, CO2, or Me3SiN3 led to the formation of the corresponding selenium-, oxo-, and nitrogen-bridged complexes 4-7. All compounds were characterized by multinuclear NMR spectroscopy and X-ray crystallography.

Regulation and Crosstalk of Cells and Factors in the Pancreatic Cancer Microenvironment.

Pancreatic cancer is a highly malignant form of cancer that distinguishes itself from other gastrointestinal tumors through significant fibrosis and unique perineural invasion. These characteristics underscore the complexity of neural regulation within the pancreatic cancer Tumor Microenvironment (TME). This review aimed to explore the regulatory mechanisms and crosstalk among stromal cells and their factors within the pancreatic cancer microenvironment. We begin by reviewing the major components of the pancreatic cancer microenvironment, analyzing interactions among crucial cell types, such as Cancer-associated Fibroblasts (CAFs) and immune cells, and revealing the dynamic changes between tumor cells and surrounding nerves, immune, and stromal cells. We discuss the role of neural factors, including the Nerve Growth Factor (NGF) and Brain-derived Neurotrophic Factor (BDNF), in the progression of pancreatic cancer and the mechanisms by which the sympathetic and parasympathetic nervous systems regulate tumor cell growth, migration, and invasion. Interactions among stromal cells, cytokines, and neural factors in the pancreatic cancer microenvironment promote fibrosis and perineural invasion. A deeper understanding of the regulation and crosstalk among components in the pancreatic cancer microenvironment offers new perspectives for inhibiting fibrosis and perineural invasion in pancreatic cancer.

Assessment of broth disk elution method for aztreonam in combination with ceftazidime/avibactam against Enterobacterales isolates.

The combination of aztreonam with ceftazidime/avibactam is considered a potential therapeutic approach for the treatment of infections caused by metallo-ß-lactamase (MBL)-producing isolates. In this study, in vitro antibacterial activity of aztreonam with avibactam against 204 carbapenemase-producing Enterobacterales was determined by broth disk elution (BDE) method of two detection volumes (5- and 2-mL broth), with broth microdilution (BMD) method as a reference. For the BDE-5mL test, the categorical agreement (CA) of ATM+CZA-lo tube (aztreonam/ceftazidime/avibactam: 6/6/4 mg/L) was 99.5%, with 0.5% major error (ME) and 0% very major error (VME); the CA of 2ATM+CZA-lo tube (12/6/4 mg/L) was 100%, with no ME and VME. For the BDE-2mL test, the CA of ATM+2CZA-hi tube (15/10/4 mg/L) was 98.5%, with 0% ME and 37.5% VME; the CA of 2ATM+2CZA-hi tube (30/10/4 mg/L) was 97.1%, with 0% ME and 75% VME. The BDE-5 mL test is an economical and practical method for clinical microbiology laboratories to determine the antibacterial susceptibility of aztreonam with avibactam against Enterobacterales, especially the 2ATM+CZA-lo tube with a final concentration of 12/6/4 mg/L of aztreonam/ceftazidime/avibactam. IMPORTANCE: Infections caused by metallo-ß-lactamase (MBL)-producing Enterobacterales are increasingly reported worldwide, and it is a significant challenge for clinical infection treatment. MBLs are adept at hydrolyzing almost all traditional ß-lactam antibiotics except aztreonam, and the enzyme activity cannot be inhibited by traditional or novel ß-lactamase inhibitors. The good thing is that the combination of aztreonam with ceftazidime/avibactam has been proven to be one of the potential therapeutic approaches for treating infections related with MBL-producing isolates. Broth microdilution (BMD) method is recommended as a reference method for its accuracy, but it is too complex to perform in most routine laboratories. Finding a more convenient, practical, and accurate susceptibility testing method for aztreonam/avibactam in clinical microbiology laboratories is very necessary. Here, we evaluated the performance of broth disk elution (BDE) method for aztreonam in combination with ceftazidime/avibactam against Enterobacterales isolates, with BMD as a reference.

Facile fabrication of cedrol nanoemulsions with deep transdermal delivery ability and high safety for effective androgenic alopecia treatment.

The successful treatment of androgenic alopecia (AGA) hinges on an effective transdermal drug delivery strategy, a challenge that requires urgent attention. In this study, we introduce a novel approach utilizing cedrol nanoemulsions (CD-NEs) for AGA treatment. Our findings demonstrate that cedrol (CD) effectively inhibits the expression of 5α-reductase 2 (5αR2), akin to the FDA-approved drug finasteride, while also surpassing it in terms of promoting cell proliferation. Through formulation optimization, we have developed stable CD-NEs suitable for large-scale production. Experimental and molecular dynamics simulations further reveal that CD-NEs enhance transdermal penetration by altering lipid organization, facilitating CD delivery to deeper skin layers via a trans-epidermal pathway. In vivo studies conducted on AGA model C57BL/6 mice demonstrate that CD-NEs significantly promote hair follicle regeneration, accelerating the transition of hair follicles from the telogen phase to the anagen phase. Moreover, CD-NEs treatment leads to a significant reduction in dihydrotestosterone (DHT) levels in the skin while maintaining stasis levels in serum, underscoring its efficacy in targeting androgenetic pathways with high safety. This comprehensive analysis sheds light on the efficacy and mechanism of action of CD-NEs in hair regeneration, offering valuable insights for future clinical applications in AGA treatment.

Comparison of the efficacy of Transarterial Embolisation (TAE) and Transarterial Chemoembolisation (TACE) therapy in patients with unresectable liver cancer: a propensity score matching study.

PURPOSE: To assess the effectiveness of transarterial bland embolization (TAE) compared with transarterial chemoembolisation (TACE) therapy in the treatment of patients with intermediate-stage hepatocellular carcinoma (HCC). METHODS: 2,297 patients with intermediate-stage HCC were screened, and 1,461 patients who received TAE or TACE as the first-choice treatment were retrospectively analyzed and baseline matched according to the two treatment methods. Subgroup analysis was performed among patients according to the "Up-to-Seven" criteria. The primary endpoint was overall survival (OS). RESULTS: A total of 1461 patients with HCC receiving TAE or TACE were included; 730 patients received TACE, and 731 received TAE. The patients in the TAE group exhibited poorer liver function and a significantly higher rate of hepatitis B infection (P<0.001) compared to the TACE group. After PSM, 504 well-matched pairs of intermediate-stage patients were selected for analysis. Univariate analysis showed TACE significantly prolonged patient survival compared with TAE (P<0.001). The 1, 2, and 3-year OS rates for the TACE group were 74.3%, 57.1%, and 44.4% and rates for the TAE group were 58.3%, 32.4%, and 21.7%. Multivariate analysis showed a HR of 0.517 (95% CI, 0.442-0.605, P<0.001) for the TACE approach over the TAE approach for OS. The TACE group had a significantly higher overall response rate than the TAE group (35% versus 26%, P = 0.024). CONCLUSION: TACE resulted in higher response rate and longer overall survival compared to TAE as the initial treatment for intermediate-stage HCC.

Solution-Processed Polymer Memcapacitors with Stimulus-Controlled and Evolvable Synaptic Functionalities: From Short-Term Plasticity to Long-Term Plasticity to Metaplasticity.

In the vanguard of neuromorphic engineering, we develop a paradigm of biocompatible polymer memcapacitors using a seamless solution process, unleashing comprehensive synaptic capabilities depending on both the stimulation form and history. Like the human brain to learn and adapt, the memcapacitors exhibit analogue-type and evolvable capacitance shifts that mirror the complex flexibility of synaptic strengthening and weakening. With increasing frequency and intensity of the stimulation, the memcapacitors demonstrate an evolution from short-term plasticity (STP) to long-term plasticity (LTP), and even to metaplasticity (MP) at a higher level. A physical picture, featuring the stimulus-controlled spatiotemporal ion redistribution in the polymer, elaborates the origin of the memcapacitive prowess and resultant versatile synaptic plasticity. The distinctive MP behavior endows the memcapacitors with a dynamic learning rate (LR), which is utilized in an artificial neural network. The superiority of implementing a dynamic LR compared with conventional practices of using constant LR shines light on the potential of the memcapacitors to exploit organic neuromorphic computing hardware.

Comprehensive monitoring and prioritizing for contaminants of emerging concern in the Upper Yangtze River, China: An integrated approach.

Contaminants of emerging concern (CECs) in aquatic environments can adversely impact ecosystems and human health even at low concentrations. This study assessed the risk of 162 CECs, including neonicotinoid pesticides, triazine pesticides, carbamate pesticides, psychoactive substances, organophosphate esters, antidepressants, per- and polyfluoroalkyl substances, and antibiotics in 10 drinking water sources and two tributaries (Jialing and Wujiang Rivers) of the Upper Yangtze River in Chongqing, China. Target screening detected 156 CECs at 0.01-2218.2 ng/L, while suspect screening via LC-QTOF-MS identified 64 CECs, with 13 pesticides, 29 pharmaceuticals and personal care products, and 2 industrial chemicals reported for the first time in the Yangtze River Basin. Risk quotient-based ecological risk assessment revealed that 48 CECs posed medium to high risks (RQ > 0.1) to aquatic life, with antibiotics (n = 20) as the main contributors. Non-carcinogenic risks were below negligible levels, but carcinogenic risks from neonicotinoids, triazines, antidepressants, and antibiotics were concerning. A multi-criteria prioritization approach integrating occurrence, physico-chemical properties, and toxicological data ranked 26 CECs as high priority. This study underscores the importance of comprehensive CEC screening in rivers and provides insights for future monitoring and management strategies.

GGT5 as a promising prognostic biomarker and its effects on tumor cell progression in gastric cancer.

Background: Gastric cancer (GC) is a gastric malignant tumor with over 1 million new cases globally each year. There are many diagnostic methods for GC, but due to the hidden early symptoms of GC, early GC is easy to be missed and misdiagnosed, which affects the follow-up treatment of patients. The early and accurate diagnosis of GC is of great significance for the treatment and survival of GC patients. Our laboratory study found that gamma-glutamyl transferase (GGT) was highly expressed in GC patients, but the mechanism of GGT family genes in the occurrence and development of GC remained to be further studied. Therefore, this study aimed to explore the mechanism of GGT family functional gene GGT5 regulating the proliferation and migration of GC cells, and provide a possible new biomarker for the early diagnosis of GC. Methods: The value of serum GGT in GC patients was first statistically analyzed. Then, The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) datasets were used to analyze the mRNA expression of GGT5 in GC, and its clinical relationship and function. Furthermore, expression of GGT5 was reduced by lentivirus RNA interference and verified by polymerase chain reaction (PCR), Cell Counting Kit-8 (CCK-8) and 5-ethynyl-2'-deoxyuridine (EdU) assays were used to detect cell proliferation after GGT5 knockdown. Scratch and Transwell assays were applied to observe cell migration after knockdown of GGT5. Finally, Western blot assays were observed to demonstrate PI3K/AKT-MAPK and MMPs expression levels after knockdown of GGT5. Results: Serum GGT was expressed at a high level in GC patients. GGT5 was highly expressed in GC tissues, and was associated with poor prognosis and clinical stage of GC. GGT5 might be involved in the regulation of vascular development and angiogenesis, as well as in the mechanisms of cell motility and migration, and it was positively correlated with the PI3K/AKT pathway. The proliferation and migration capacity of GC cells was dampened by downregulation of GGT5. GGT5 mediated proliferation and migration of GC cells by directly targeting PI3K/AKT-MAPK-MMPs pathways. Conclusions: Low expression of GGT5 reduced proliferation and migration in GC cells by modulating the PI3K/AKT-MAPK-MMPs pathway, and GGT5 might be a new target for GC.

Risk prediction of postoperative permanent stroke in acute type A aortic dissection patients with severe common carotid artery stenosis using brain CT perfusion.

Rationale and objectives: To explore the feasibility and predictive utility for neurological outcomes of brain computed tomography perfusion (CTP) for surgically treated acute type A aortic dissection patients with severe common carotid artery stenosis. Materials and methods: Consecutive acute type A aortic dissection patients with severe common carotid artery stenosis undergoing preoperative brain computed tomography perfusion and surgery at our center were examined in retrospect. Brain perfusion was assessed using parameters including cerebral blood flow, cerebral blood volume, mean transmit time, time to maximum, penumbra volume and infarct core volume. Univariable and multivariable regression analyses were performed to identify clinical and imaging predictors associated with postoperative permanent stroke. Results: Out of 44 patients included, 19 patients (43.2 %) presented with postoperative permanent stroke. Univariable analysis revealed that internal carotid artery dissection, cerebral blood flow of the affected side, cerebral blood volume of the affected side, and penumbra volume were implicated in postoperative permanent stroke. Multivariable analysis further showed that cerebral blood flow of the affected side was an independent indicator of a permanent stroke following surgery (odds ratio: 0.820, 95 % confidence interval: 0.684-0.982; p = 0.012). The area under the receiver operating characteristic curve was 0.867 (95 % confidence interval: 0.764-0.970), and the optimal cut-off value was 45.6mL/100 mL/min. Conclusion: Cerebral blood flow of the affected side was an independent indicator of permanent stroke following surgery in acute type A aortic dissection patients with severe common carotid artery stenosis. Brain CTP could be a helpful modality for quantitative evaluation of cerebral malperfusion and neurological prognostication.

Employing Raman Spectroscopy and Machine Learning for the Identification of Breast Cancer.

BACKGROUND: Breast cancer poses a significant health risk to women worldwide, with approximately 30% being diagnosed annually in the United States. The identification of cancerous mammary tissues from non-cancerous ones during surgery is crucial for the complete removal of tumors. RESULTS: Our study innovatively utilized machine learning techniques (Random Forest (RF), Support Vector Machine (SVM), and Convolutional Neural Network (CNN)) alongside Raman spectroscopy to streamline and hasten the differentiation of normal and late-stage cancerous mammary tissues in mice. The classification accuracy rates achieved by these models were 94.47% for RF, 96.76% for SVM, and 97.58% for CNN, respectively. To our best knowledge, this study was the first effort in comparing the effectiveness of these three machine-learning techniques in classifying breast cancer tissues based on their Raman spectra. Moreover, we innovatively identified specific spectral peaks that contribute to the molecular characteristics of the murine cancerous and non-cancerous tissues. CONCLUSIONS: Consequently, our integrated approach of machine learning and Raman spectroscopy presents a non-invasive, swift diagnostic tool for breast cancer, offering promising applications in intraoperative settings.

Lipopolysaccharide Triggers Luminal Acidification to Promote Defense Against Bacterial Infection in Vaginal Epithelium.

The vaginal epithelium plays pivotal roles in host defense against pathogen invasion, contributing to the maintenance of an acidic microenvironment within the vaginal lumen through the activity of acid-base transport proteins. However, the precise defense mechanisms of the vaginal epithelium after a bacterial infection remain incompletely understood. This study showed that bacterial lipopolysaccharide (LPS) potentiated net proton efflux by up-regulating the expression of Na+-H+ exchanger 1 (NHE1) without affecting other acid-base transport proteins in vaginal epithelial cells. Pharmacologic inhibition or genetic knockdown of Toll-like receptor-4 and the extracellular signal-regulated protein kinase signaling pathway effectively counteracted the up-regulation of NHE1 and the enhanced proton efflux triggered by LPS in vaginal epithelial cells. In vivo studies revealed that LPS administration led to luminal acidification through the up-regulation of NHE1 expression in the rat vagina. Moreover, inhibition of NHE exhibited an impaired defense against acute bacterial infection in the rat vagina. These findings collectively indicate the active involvement of vaginal epithelial cells in facilitating luminal acidification during acute bacterial infection, offering potential insights into the treatment of bacterial vaginosis.

Patient-Reported Outcomes of Postoperative NSCLC Patients with or without Staged Chinese Herb Medicine Therapy during Adjuvant Chemotherapy (NALLC 2): A Randomized, Double-Blind, Placebo-Controlled Trial.

OBJECTIVE: To investigate whether the combination of chemotherapy with staged Chinese herbal medicine (CHM) therapy could enhance health-related quality of life (QoL) in non-small-cell lung cancer (NSCLC) patients and prolong the time before deterioration of lung cancer symptoms, in comparison to chemotherapy alone. METHODS: A prospective, double-blind, randomized, controlled trial was conducted from December 14, 2017 to August 28, 2020. A total of 180 patients with stage I B-IIIA NSCLC from 5 hospitals in Shanghai were randomly divided into chemotherapy combined with CHM (chemo+CHM) group (120 cases) or chemotherapy combined with placebo (chemo+placebo) group (60 cases) using stratified blocking randomization. The European Organization for Research and Treatment of Cancer (EORTC) Quality-of-Life-Core 30 Scale (QLQ-C30) was used to evaluate the patient-reported outcomes (PROs) during postoperative adjuvant chemotherapy in patients with early-stage NSCLC. Adverse events (AEs) were assessed in the safety analysis. RESULTS: Out of the total 180 patients, 173 patients (116 in the chemo+CHM group and 57 in the chemo+placebo group) were included in the PRO analyses. The initial mean QLQ-C30 Global Health Status (GHS)/QoL scores at baseline were 57.16 ± 1.64 and 57.67 ± 2.25 for the two respective groups (P>0.05). Compared with baseline, the chemo+CHM group had an improvement in EORTC QLQ-C30 GHS/QoL score at week 18 [least squares mean (LSM) change 17.83, 95% confidence interval (CI) 14.29 to 21.38]. Conversely, the chemo+placebo group had a decrease in the score (LSM change -13.67, 95% CI -22.70 to -4.63). A significant between-group difference in the LSM GHS/QoL score was observed, amounting to 31.63 points (95% CI 25.61 to 37.64, P<0.001). The similar trends were observed in physical functioning, fatigue and appetite loss. At week 18, patients in the chemo+CHM group had a higher proportion of improvement or stabilization in GHS/QoL functional and symptom scores compared to chemo+placebo group (P<0.001). The median time to deterioration was longer in the chemo+CHM group for GHS/QoL score [hazard ratio (HR)=0.33, 95% CI 0.23 to 0.48, P<0.0010], physical functioning (HR=0.43, 95% CI 0.25 to 0.75, P=0.0005), fatigue (HR=0.47, 95% CI 0.30 to 0.72, P<0.0001) and appetite loss (HR=0.65, 95% CI 0.42 to 1.00, P=0.0215). The incidence of AEs was lower in the chemo+CHM group than in the chemo+placebo group (9.83% vs. 15.79%, P=0.52). CONCLUSION: The staged CHM therapy could help improve the PROs of postoperative patients with early-stage NSCLC during adjuvant chemotherapy, which is worthy of further clinical research. (Registry No. NCT03372694).

A High-Throughput Visual Screen for the Directed Evolution of C ß -stereoselectivity of L-threonine Aldolase.

L-Threonine aldolase (L-TA) is a pyridoxal phosphate-dependent enzyme that catalyzes the reversible condensation of glycine and aldehydes to form ß-hydroxy-α-amino acids. The combination of directed evolution and efficient high-throughput screening methods is an effective strategy for enhancing the enzyme's catalytic performance. However, few feasible high-throughput methods exist for engineering the Cß-stereoselectivity of L-TAs. Here, we present a novel method of screening for variants with improved Cß-stereoselectivity; this method couples an L-threo-phenylserine dehydrogenase, which catalyzes the specific oxidation of L-threo-4-methylsulfonylphenylserine (L-threo-MTPS), with the concurrent synthesis of NADPH, which is easily detectable via 340-nm UV absorption. This enables the visual detection of L-threo-MTPS produced by L-TA through the measurement of generated NADPH. Using this method, we discover an L-TA variant with significantly higher diastereoselectivity, increasing from 0.98% de (for the wild-type) to 71.9% de.

Extragastrointestinal stromal tumors with diffuse membranous distribution with bleeding: A case report.

BACKGROUND: Extragastrointestinal stromal tumors (EGIST) and gastrointestinal stromal tumors are of similar pathological type and form. Here we report a rare case of EGIST diffusely distributed in membranous tissue in abdominal cavity, the feature of which included diffuse tumors at membranous tissue in entire abdominal cavity and spontaneous bleeding of the tumors. CASE SUMMARY: The patient was a 71-year man and hospitalized due to continuous pain at lower abdomen for more than 10 days. Upon physical examination, the patient had flat and tough abdomen with mild pressing pain at lower abdomen, no obvious abdominal mass was touchable, and shifting dullness was positive. Positron emission tomography-computed tomography (CT) showed that in his peritoneal cavity, there were multiple nodules of various sizes, seroperitoneum, multiple enlarged lymph nodes in abdominal/pelvic cavity and right external ilium as well as pulmonary nodules. Plain CT scanning at epigastrium/hypogastrium/pelvic cavity + enhanced three-dimensional reconstruction revealed multiple soft tissue nodules in abdominal/pelvic cavity, peritoneum and right groin. Tumor marker of carbohydrate antigen 125 was 808 U/mL, diffuse tuberous tumor was seen in abdominal/pelvic cavity during operation with hematocelia, and postoperative pathological examination confirmed EGIST. Imatinib was administered with better therapeutic effect. CONCLUSION: Gene testing showed breast cancer susceptibility gene 1 interacting protein C-terminal helicase 1 and KIT genovariation, and the patient was treated with imatinib follow-up visit found that his clinical symptoms disappeared and the tumor load alleviated obviously via imageological examination.

Copper Sensing Transcription Factor ArsR2 Regulates VjbR to Sustain Virulence in Brucella abortus.

ABSTRACTBrucellosis, caused by the intracellular pathogen Brucella, is a major zoonotic infection that promotes reproductive disease in domestic animals and chronic debilitating conditions in humans. The ArsR family of transcriptional regulators plays key roles in diverse cellular processes, including metal ion homeostasis, responding to adverse conditions, and virulence. However, little is known about the function of ArsR family members in Brucella. Here, we identified ArsR2 as a nonclassical member of the family that lacks autoregulatory function, but which nevertheless plays a vital role in maintaining copper homeostasis in B. abortus. ArsR2 is a global regulator of 241 genes, including those involved in the VirB type IV secretion system (T4SS). Significantly, ArsR2 regulates T4SS production in B. abortus by targeting VjbR which encodes a LuxR-type family transcriptional regulator. Moreover, copper modulates transcriptional activity of ArsR2, but not of VjbR. Furthermore, deletion of arsR2 attenuated virulence in a mouse model. Collectively, these findings enhance understanding of the mechanism by which ArsR proteins regulate virulence gene expression in pathogenic Brucella species.