RNA transcription assisted universal CRISPR/Cas12a system for programmable analysis of multiple colorectal cancer-associated microRNAs.

Accurate analysis of multiple microRNA (miRNA) levels is significantly valuable for early diagnosis of colorectal cancer noninvasively considering the miRNA expression is highly relevant to the occurrence and progression of cancer. However, the low abundance and high sequence homology of miRNAs make their precise determination extremely challenging. Here, we developed a universal and programmable diagnostic strategy allowing for analyzing multiple colorectal cancer-associated miRNAs. The system combined sequentially programmable rolling circle transcription (RCT) and the CRISPR/Cas12a system with high trans-cleavage activity to achieve highly sensitive and specific detection of four target miRNAs. Owing to the remarkable performance of universal RCT-Cas12a strategy, this biosensor could detect miR-21, miR-17, miR-31 and miR-92a with a LOD of 2.1, 1.6, 3.7 and 1.0 pM, respectively. This strategy had a unique advantage in distinguishing human normal colon epithelial cells lines (NCM460) from human colon cancer cells (HT29). In particular, the designed system exhibited superior analytical capability in distinguishing paracancerous and colorectal cancer tissues from patients undergoing colorectal cancer surgery. This arbitrarily programmable, scalable, fast and specific strategy potentially offered an attractive alternative to handle varied challenges encountered with CRISPR-based systems, and held immense promise in scientific research and clinical applications.

Influence of Aging on Outcomes of Sacubitril/Valsartan in Hypertensive Patients with Heart Failure: A Multicenter Retrospective Study.

BACKGROUND: The aim of this study was to investigate the influence of aging on the effectiveness and tolerance of sacubitril/valsartan (sac/val) among hypertensive patients complicated with heart failure in a real-world setting. METHODS: This multicenter, retrospective study included patients (≥18 years old) admitted with a diagnosis of hypertension and heart failure, starting sac/val therapy between January 2020 and December 2021 from 3 medical centers. Patients were grouped by the cutoff age of 65 years. Outcomes were collected 31-365 days after the initiation of sac/val and were compared in a matched cohort after 1: 1 propensity score matching (PSM). RESULTS: A total of 794 patients were finally analyzed. Blood pressure and cardiac functions improved significantly compared with values at baseline. There were 269 patients in each cohort (<65 years and ≥65 years) after PSM. After PSM, the incidence of hyperuricemia and hypotension in the elderly patients (≥65 years) was significantly higher than in those <65 years of age. Kaplan-Meier estimate suggested that the cumulative incidence of new or recurrent cardiovascular events increased significantly at the age of ≥65 years after the point of 3 months (log-rank P =.00087). CONCLUSION: Sac/val benefited patients in both cohorts by improving blood pressure and cardiac function. Elderly patients (≥65 years) were susceptible to hypotension, low diastolic blood pressure, hyperuricemia, and underwent cardiac-related readmissions more frequently.

Sacubitril/Valsartan in Heart Failure with Hypertension Patients: Real-World Experiences on Different Ages, Drug Doses, and Renal Functions.

INTRODUCTION: Hypertension is a significant risk factor in heart failure for worldwide patients. More than half of hypertensive patients suffer from heart failure. Recently, sacubitril/valsartan (sac/val) has been approved as an antihypertensive agent in China and Japan. Additionally, it is not approved for treating hypertension in Europe or the USA. AIM: To accumulate more real-world experiences to investigate the effectiveness and optimize clinical medication of sac/val in hypertensive patients with heart failure. METHODS: We retrospectively enrolled adult patients diagnosed with hypertension (HTN) and heart failure (HF) and newly treated with sac/val. The baseline characteristics and clinical outcomes were retrospectively extracted from electronic medical records (EMR) in three centers. The efficacy and safety of sac/val were first analyzed in all enrolled patients. Stratified analyses were conducted in patients with different ages (≥ 65, < 65), maximum tolerated doses (≥ 200 mg/days, < 200 mg/days), and renal functions (e-GFR ≥ 60 ml/min/1.73 m2, < 60 ml/min/1.73 m2). RESULTS: Overall, 794 patients diagnosed with both HF and HTN were included in our study. During follow-up, significant reductions were found in blood pressure (BP) (SBP 12.8 ± 21.2 mmHg, P < 0.001, DBP 7.1 ± 16.5 mmHg, P < 0.001), and cardiac biomarkers (cardiac troponin 1.78 ± 19.1 ng/mL, P < 0.001, NT-proBNP 1403 ± 6937 pg/mL, P < 0.001) from baseline. In stratification analyses, the lower dosage group earned a higher BP control rate (83.4% vs. 75.6%, P = 0.025) and an overall improvement rate of cardiac indicators (61.3% vs. 48.0%, P = 0.002). The younger patients' group had significantly less cumulative hazard of recurrent cerebral-cardiovascular events than the elder group (log-rank P value < 0.001). Patients with renal dysfunction were observed with more AE incidences. CONCLUSIONS: Sac/val could reduce BP and improve cardiac structural and functional parameters in hypertensive patients with HF, even with less than target doses. However, more attention should be paid to older patients and renal dysfunction patients when using sac/val because of additional risks in adverse events.

Rolling circle transcription and CRISPR/Cas12a-assisted versatile bicyclic cascade amplification assay for sensitive uracil-DNA glycosylase detection.

Uracil-DNA glycosylase (UDG) is pivotal in maintaining genome integrity and aberrant expressed UDG is highly relevant to numerous diseases. Sensitive and accurate detecting UDG is critically significant for early clinical diagnosis. In this research, we demonstrated a sensitive UDG fluorescent assay based on rolling circle transcription (RCT)/CRISPR/Cas12a-assisted bicyclic cascade amplification strategy. Target UDG catalyzed to remove uracil base of DNA dumbbell-shape substrate probe (SubUDG) to produce an apurinic/apyrimidinic (AP) site, at which SubUDG was cleaved by apurinic/apyrimidinic endonuclease (APE1) subsequently. The exposed 5'-PO4 was ligated with the free 3'-OH terminus to form an enclosed DNA dumbbell-shape substrate probe (E-SubUDG). E-SubUDG functioned as a template can actuate T7 RNA polymerase-mediated RCT signal amplification, generating multitudes of crRNA repeats. The resultant Cas12a/crRNA/activator ternary complex activated the activity of Cas12a, causing a significantly enhanced fluorescence output. In this bicyclic cascade strategy, target UDG was amplified via RCT and CRISPR/Cas12a, and the whole reaction was completed without complex procedures. This method enabled sensitive and specific monitor UDG down to 0.0005 U/mL, screen corresponding inhibitors, and analyze endogenous UDG in A549 cells at single-cell level. Importantly, this assay can be extended to analyze other DNA glycosylase (hAAG and Fpg) by altering the recognition site in DNA substrates probe rationally, thereby offering a potent tool for DNA glycosylase-associated clinical diagnosis and biomedical research.

Prognostic performance of the NRS2002, NUTRIC, and modified NUTRIC to identify high nutritional risk in severe acute pancreatitis patients.

Background: Acute pancreatitis (AP) is the most common gastrointestinal disease requiring hospital admission. AP patients are categorized as mild, moderately severe, and severe AP (SAP). For SAP patients, malnutrition increases susceptibility to infection and mortality. The Nutritional Risk Screening 2002 (NRS 2002), the Nutrition Risk in Critically Ill (NUTRIC) score and modified Nutrition Risk in Critically Ill (mNUTRIC) are nutritional risk screening tools of critically ill patients and have not been validated in patients with SAP. It is essential to evaluate the prognostic performance of these nutritional risk screening tools. Materials and methods: A retrospective study was designed to validate the NRS 2002, NUTRIC, and mNUTRIC when applied to SAP patients. Receiver operating characteristic curves were plotted to investigate the predictive ability of clinical outcomes by comparing areas under the curve (AUC). Appropriate cut-offs were calculated by using Youden's index. Patients were identified as being at high nutritional risk according to the calculated cut-off values. The effects of different scoring systems on mortalities were calculated using the Cox proportional hazards model. Logistic regression was used to assess the association between the energy provision and 28-day mortality. Results: From January 2013 to December 2019, 234 SAP patients were included and analyzed. Patients categorized as high nutritional risk by the NRS 2002 (12.6% versus 1.9% for 28-day and 20.5% versus 3.7% for 90-day), NUTRIC (16.2% versus 0.0% for 28-day and 27.0% versus 0.0% for 90-day), and mNUTRIC (16.4% versus 0.0% for 28-day and 26.4% versus 0.8% for 90-day) had significant higher mortality than those categorized as low nutritional risk. The NUTRIC (AUC: 0.861 for 28-day mortality and 0.871 for 90-day mortality, both cut-off value ≥3) and mNUTRIC (AUC: 0.838 for 28-day and 0.828 for 90-day mortality, both cut-off value ≥3) showed better predictive ability of the 28- and 90-day mortality than the NRS 2002 (AUC: 0.706 for 28-day mortality and 0.695 for 90-day mortality, both cut-off value ≥5). Conclusion: The NRS 2002, NUTRIC, and mNUTRIC scores were predictors for the 28- and 90-day mortalities. The NUTRIC and mNUTRIC showed better predictive ability compared with the NRS 2002 when applied to SAP patients.

Risk factor analysis of omicron patients with mental health problems in the Fangcang shelter hospital based on psychiatric drug intervention during the COVID-19 pandemic in Shanghai, China.

Backgrounds: The widespread coronavirus disease 2019 (COVID-19) outbreak impacted the mental health of infected patients admitted to Fangcang shelter hospital a large-scale, temporary structure converted from existing public venues to isolate patients with mild or moderate symptoms of COVID-19 infection. Objective: This study aimed to investigate the risk factors of the infected patients from a new pharmacological perspective based on psychiatric drug consumption rather than questionnaires for the first time. Methods: We summarised the medical information and analysed the prevalence proportion, characteristics, and the related risk factors of omicron variants infected patients in the Fangcang Shelter Hospital of the National Exhibition and Convention Center (Shanghai) from 9 April 2022 to 31 May 2022. Results: In this study, 6,218 individuals at 3.57% of all admitted patients in the Fangcang shelter were collected suffering from mental health problems in severe conditions including schizophrenia, depression, insomnia, and anxiety who needed psychiatric drug intervention. In the group, 97.44% experienced their first prescription of psychiatric drugs and had no diagnosed historical psychiatric diseases. Further analysis indicated that female sex, no vaccination, older age, longer hospitalization time, and more comorbidities were independent risk factors for the drug-intervened patients. Conclusion: This is the first study to analyse the mental health problems of omicron variants infected patients hospitalised in Fangcang shelter hospitals. The research demonstrated the necessity of potential mental and psychological service development in Fangcang shelters during the COVID-19 pandemic and other public emergency responses.

Risk of reactive cutaneous capillary endothelial proliferation induced by camrelizumab in patients with non-small cell lung cancer: a retrospective study.

Background: Reactive cutaneous capillary endothelial proliferation (RCCEP) is a common immune-related adverse event (irAE) related to camrelizumab. This study aimed to investigate the risk factors of RCCEP and its association with patients' survival. Methods: This retrospective study collected the data of consecutive patients with non-small cell lung cancer (NSCLC) who received camrelizumab between January 2019 and December 2021. Baseline characteristics and peripheral blood biomarkers were collected. The outcomes were the occurrence of RCCEP and progression-free survival (PFS). The factors associated with RCCEP were analyzed using univariable and multivariable logistic regression. The association between PFS and RCCEP occurrence was analyzed by the log-rank test. Results: Among the 80 patients included, 24 (30.0%) developed RCCEP, and 56 did not. Among the patients with RCCEP, only four reported the occurrence of grade 3-4 RCCEP. The multivariable analysis revealed that a percentage of eosinophil (EOS%) >1.75% was significantly associated with a higher risk of RCCEP [odds ratio (OR) =4.484; 95% confidence interval (CI): 1.139-17.651] and camrelizumab combined with an anti-angiogenic agent was significantly associated with a lower risk of RCCEP (OR =0.188; 95% CI: 0.055-0.639). The median PFS was numerically longer in patients with RCCEP than in those who did not (17 vs. 9 months, P=0.069). Patients who had baseline EOS% >1.75% and received camrelizumab without an anti-angiogenic agent had a longer median PFS than those who did not (17 vs. 9 months, P=0.011). Conclusions: Baseline EOS% >1.75% and camrelizumab without an anti-angiogenic agent were risk factors of RCCEP and might be associated with better survival in patients with NSCLC.

Intrathecal or Intraventricular Tigecycline Therapy for Central Nervous System Infection Associated with Carbapenem-Resistant Klebsiella pneumoniae.

Purpose: Infection with carbapenem-resistant Klebsiella pneumoniae (CRKP) is a great challenge. Central nervous system (CNS) infection caused by CRKP is rarely reported, and effective treatment is limited. Thus, this study aimed to assess intrathecal (IT) or intraventricular (IVT) injection of tigecycline for clearing infection with CRKP in CNS. Patients and Methods: Two patients who had intracranial infection with CRKP after craniotomy were treated in our institution and analyzed retrospectively, summarizing their therapeutic schedules. Results: They all had a fever with the positive results of cerebrospinal fluid (CSF) test, and CSF culture showed positive for CPKP, which was sensitive only to tigecycline. In addition, the MIC of polymyxin B was not tested due to the limited laboratory conditions. After IT or IVT injection of tigecycline treatment, the temperature of the patients became normal in 3 days, with normal levels of white blood cells, protein, glucose and chlorine concentrations in the CSF. Crucially, twice CSF cultures also became negative with no clinical symptoms of intracranial infection after IT or IVT injection of tigecycline treatment. Moreover, there were no adverse drug reactions observed. Conclusion: IT or IVT injection of tigecycline may be a bright choice to control intracranial infection with CRKP.

[Study of protective effect and mechanism of vitamin C in lipopolysaccharide-induced septic renal injury].

OBJECTIVE: To explore the protective effect and its mechanism of vitamin C on septic renal injury induced by lipopolysaccharide (LPS). METHODS: Renal tubular epithelial cells HK-2 were induced with 10 mg/L LPS for 8 hours and 12 hours, respectively, and then 0.5 mmol/L and 1 mmol/L vitamin C were added, respectively. Cell viability was measured using cell proliferation and toxicity assay cell counting kit-8 (CCK-8) to determine suitable condition for subsequent experiments. HK-2 cells were divided into control group, LPS group and LPS+vitamin C group (LPS+VC group). The contents of necrosis factors phosphorylated mixed lineage kinase domain-like protein (p-MLKL) and phosphorylated receptor-interacting protein kinase 3 (p-RIPK3) were measured by Western blotting. The contents of inflammatory factors interleukin-1ß (IL-1ß) and tumor necrosis factor-α (TNF-α) were determined by enzyme linked immunosorbent assay (ELISA) in each group. Differences among the groups were compared. RESULTS: CCK-8 showed that 1 mmol/L vitamin C improved the survival rate of HK-2 cells to 86% after 12 hours of LPS induction, so this condition was selected for subsequent experiments. After 12 hours LPS induction in HK-2 cells, the expressions of p-MLKL and p-RIPK3 were significantly higher than those of the control group, and the levels of IL-1ß and TNF-α were also significantly higher than those of the control group [IL-1ß (ng/L): 23.2±1.4 vs. 12.8±3.9, TNF-α (ng/L): 36.4±3.9 vs. 11.6±1.8, both P < 0.05], indicating the co-existence of cell necrosis and inflammation. Compared with LPS group, 1 mmol/L vitamin C significantly decreased the protein expression of p-MLKL and p-RIPK3, and also significantly decreased the levels of IL-1ß and TNF-α [IL-1ß (ng/L): 19.8±0.7 vs. 23.2±1.4, TNF-α (ng/L): 17.4±5.8 vs. 36.4±3.9, both P < 0.05]. CONCLUSIONS: Vitamin C can alleviate LPS-induced HK-2 cell damage, and reduce the expressions of necrotic factors and inflammatory factors.

Honokiol Microemulsion Causes Stage-Dependent Toxicity Via Dual Roles in Oxidation-Reduction and Apoptosis through FoxO Signaling Pathway.

Honokiol, the main bioactive extract of Magnolia officinalis, exhibits extensive therapeutic actions. Its treatment for advanced non-small cell lung cancer is undergoing clinical trials in China. However, the published safety evaluation studies have focused on extract mixtures of Magnolia officinalis in which the honokiol content was well below the reported clinical dose of the honokiol monomer. Therefore, safety assessment of the honokiol monomer is urgently needed. Our previous studies have already demonstrated that a high dose of the honokiol microemulsion (0.6 µg/mL) induces developmental toxicity in rats and zebrafish by inducing oxidative stress. By exploring the relationship between time and toxicity, we found that developmental toxic responses were stage-dependent. They mainly occurred within the first 24 h post fertilization (hpf) especially the first 12 hpf. In zebrafish, low doses of honokiol microemulsion (0.15, 0.21 µg/mL) significantly decreased the levels of reactive oxygen species (ROS) and malondialdehyde (MDA) and increased the mRNA expression of bcl-2. In contrast, high dose (0.6 µg/mL) increased the levels of ROS and MDA, decreased activities and mRNA expression of superoxide dismutase (SOD) and catalase (CAT), and increased mRNA expression of bax, c-jnk, p53 and bim. By acridine orange staining, we found that a high dose of honokiol microemulsion induced apoptosis mainly in zebrafish brain. In rat pheochromocytoma cells (PC12 cells), low doses of the honokiol microemulsion (1, 5, 10 µM) exerted a protective effect against H2O2-induced oxidative damage while high doses (≥20 µM) induced oxidative stress, which further confirms the dual effects of honokiol microemulsion on nerve cells. These dual roles of the honokiol microemulsion in oxidation-reduction reactions and apoptosis may be regulated by the forkhead box class O (FoxO) signaling pathway. Due to the potential of developmental toxicity, we recommend that the administration of high dose honokiol microemulsion in pregnant women should be considered with caution.

Research progress regarding long-chain non-coding RNA in lung cancer: a narrative review.

Background and Objective: Lung cancer is the main cause of cancer-related death worldwide, and its incidence rate is high. Traditional methods of lung cancer screening, such as those based on X-ray, low-dose computed tomography (LDCT), positron emission computed tomography (PET/CT), electronic bronchoscopy, and serum tumor markers were not satisfied with the urgent need in improving the patient survival rate. Thus, biomarkers for early diagnosis and prognosis of lung cancer are extremely needed. Studies have identified a variety of long-chain non-coding RNAs (lncRNAs) that are expressed at abnormal levels in patients with lung cancer which was believed as a potential biomarker for the diagnosis and prognostic evaluation of lung cancer. This review aims to discuss the role of lncRNAs in non-small cell lung cancer (NSCLC), so as to provide insights into the prognosis of lung cancer. Methods: We searched PubMed database of the related scientific researches with outcomes from 09/16/2011 to 05/02/2022 focusing on lncRNA application in lung cancer via searching terms of "lncRNA AND lung cancer", "lncRNA AND non-small cell lung cancer", "lncRNA AND drug resistance", "lncRNA AND radio sensitivity". Published articles written in English available to readers were considered. Key Content and Findings: We summarized significantly differentially-expressed lncRNAs in lung cancer tissues compared with healthy individuals and normal tissues which would become potential biomarkers for lung cancer diagnosis and therapeutic target as a non-invasive detection method. Conclusions: LncRNAs might be valuable potential diagnostic biomarkers of lung cancer progression.

Ceftazidime/Avibactam-Based Versus Polymyxin B-Based Therapeutic Regimens for the Treatment of Carbapenem-Resistant Klebsiella pneumoniae Infection in Critically Ill Patients: A Retrospective Cohort Study.

INTRODUCTION: Considering the importance of ceftazidime/avibactam (CAZ/AVI) and polymyxin B (PMB) in treating carbapenem-resistant Klebsiella pneumoniae (CRKP) infection, it is essential to evaluate the efficacy and safety of these agents and provide appropriate medical advice to clinical specialists. METHODS: We conducted a retrospective cohort study in two Chinese tertiary hospitals for critically ill patients with CRKP infection who received at least 24-h CAZ/AVI-based or PMB-based treatment. A binary logistic model and a Cox proportional hazards regression model were constructed to analyze variables that could potentially affect 30-day microbiological eradication and all-cause mortality, respectively. RESULTS: From January 2019 to December 2021, 164 eligible patients were divided into CAZ/AVI and PMB cohorts. A notably lower 30-day mortality rate (35.4% vs 69.5%, P < 0.001) and a higher 30-day microbiological eradication rate (80.5% vs 32.9%, P < 0.001) were observed for patients receiving CAZ/AVI-based treatment, compared with cases in the PMB group. A longer antimicrobial treatment duration (> 7 days) could also significantly decrease the mortality rate and increase the microbiological eradication rate. Female patients had a higher survival rate than male patients. Age over 65 years, sepsis, continuous renal replacement therapy, and organ transplantation were identified as negative factors for survival. In the subgroup analysis, CAZ/AVI combined with tigecycline or amikacin could effectively lower mortality. According to safety evaluation results, potential elevation of hepatic enzymes was associated with CAZ/AVI-based treatment, while renal impairment was probably related to PMB-based treatment. CONCLUSIONS: CAZ/AVI was more effective than PMB in treating CRKP-infected patients. Tigecycline and amikacin were proven to be beneficial as concomitant agents in combination with CAZ/AVI. A treatment period lasting over 7 days was recommended. Hepatoxicity of CAZ/AVI and nephrotoxicity of PMB should be monitored carefully. Further well-designed studies should be performed to verify our conclusion.

Risk of polymyxin B-induced acute kidney injury with a non adjusted dose versus adjusted dose based on renal function.

Aim: To observe the difference in the risk of polymyxin B (PMB)-induced acute kidney injury (AKI) with or without dose adjustment based on the patients renal function. Materials & methods: This retrospective cohort analysis was carried out in 115 patients treated with PMB from November 2018 to October 2019. Results: No significant difference in the incidence of AKI as well as secondary outcomes was observed between these two groups (47.5 vs 37.14%; p = 0.304). Conclusion: Dosing adjustment based on renal function does not significantly lower the risk of PMB-induced AKI. A non adjusted dosing strategy for PMB is recommended in patients exhibiting various levels of renal impairment.

N-acetylcysteine Ameliorates Vancomycin-induced Nephrotoxicity by Inhibiting Oxidative Stress and Apoptosis in the in vivo and in vitro Models.

Background: Oxidative stress-related apoptosis is considered as the key mechanism implicated in the pathophysiology of nephrotoxicity with vancomycin (VCM) therapy. We evaluated the possible effects of N-acetylcysteine (NAC) on VCM-induced nephrotoxicity and the underlying mechanism. Methods: VCM-induced nephrotoxicity was established using HK-2 cells and SD rats and observed by measuring cell survival, kidney histological changes, renal function and kidney injury related markers (KIM-1 and NGAL). Oxidative stress, renal cell apoptosis and the involved signaling pathways were also evaluated. Results: In model rats, NAC could protect against VCM-induced acute kidney injury with histological damage, renal dysfunction, and increased Cre and BUN levels. In HK-2 cells, VCM-induced decreased cell viability was restored by NAC. In addition, increased expression of caspase-3, KIM-1 and NGAL suffering from VCM was also reversed by NAC in vivo and in vitro. NAC inhibited ROS production, decreased cell apoptosis by decreasing the Bax/Bcl-2 ratio and caspase-3 expression in HK-2 cells and regulated oxidative stress indicators in the kidney by decreasing GSH, SOD and CAT activity and increasing MDA levels. Furthermore, NAC could effectively reverse VCM-associated increased P38 MAPK/JNK phosphorylation. Conclusions: The results demonstrated that NAC had a protective effect against nephrotoxicity from VCM by inhibiting oxidative stress and apoptosis via P38 MAPK/JNK.

Traditional Chinese medicine extracts as novel corrosion inhibitors for AZ91 magnesium alloy in saline environment.

Zingiber officinale Roscoe extract, Raphanus sativus L. extract, Rheum palmatum extract, Coptis chinensis extract, Glycyrrhiza uralensis extract (GUE), Potentilla discolor extract (PDE) and Taraxacum officinale extract (TOE) were screened for the green corrosion inhibitors of AZ91 alloy in saline environment. The experiment results demonstrated that GUE, PDE and TOE can significantly enhance the corrosion resistance of AZ91 alloy by 73.4, 87.6 and 84.6%, respectively. Surface characterization using FTIR, UV-Vis and XPS revealed that the organic compounds of GUE, PDE and TOE can interact with the alloy surface to form a protective physisorbed film, effectively mitigating the corrosion process of AZ91 alloy. The present results may be helpful to discover the new green inhibitors with high inhibition efficiency for AZ91 alloy.

Autopromotion of K-Ras4B Feedback Activation Through an SOS-Mediated Long-Range Allosteric Effect.

The Ras-specific guanine nucleotide exchange factors Son of Sevenless (SOS) regulates Ras activation by converting inactive GDP-bound to active GTP-bound states. The catalytic activity of Ras is further allosterically regulated by GTP-Ras bound to a distal site through a positive feedback loop. To address the mechanism underlying the long-range allosteric activation of the catalytic K-Ras4B by an additional allosteric GTP-Ras through SOS, we employed molecular dynamics simulation of the K-Ras4BG13D•SOScat complex with and without an allosteric GTP-bound K-Ras4BG13D. We found that the binding of an allosteric GTP-K-Ras4BG13D enhanced the affinity between the catalytic K-Ras4BG13D and SOScat, forming a more stable conformational state. The peeling away of the switch I from the nucleotide binding site facilitated the dissociation of GDP, thereby contributing to the increased nucleotide exchange rate. The community networks further showed stronger edge connection upon allosteric GTP-K-Ras4BG13D binding, which represented an increased interaction between catalytic K-Ras4BG13D and SOScat. Moreover, GTP-K-Ras4BG13D binding transmitted allosteric signaling pathways though the Cdc25 domain of SOS that enhanced the allosteric regulatory from the K-Ras4BG13D allosteric site to the catalytic site. This study may provide an in-depth mechanism for abnormal activation and allosteric regulation of K-Ras4BG13D.

Drug-Drug Interactions and Disease Status Are Associated With Irinotecan-Induced Hepatotoxicity: A Cross-Sectional Study in Shanghai.

Irinotecan-induced hepatotoxicity can cause severe clinical complications in patients; however, the underlying mechanism and factors affecting hepatotoxicity have rarely been investigated. In this cross-sectional study, we screened all clinical, demographic, medication, and genetic variables among 126 patients receiving irinotecan and explored potential associations with the incidence and time to onset of irinotecan-induced hepatotoxicity. Approximately 38.9% of the patients suffered from hepatotoxicity after irinotecan administration. The presence of cardiovascular diseases increases the incidence of hepatotoxicity ≈2.9-fold and doubles the hazard of time to hepatotoxicity. Patients with liver metastasis had a >4-fold higher risk of hepatotoxicity and a 3.5-fold increased hazard of time to hepatotoxicity compared to those without liver metastasis. Patients who took cytochrome P450 (CYP) 3A inducers had a 4.4-fold increased incidence of hepatotoxicity, and furthermore, concomitant use of platinum-based antineoplastics revealed 4.2 times the hazard of time to hepatotoxicity compared to those receiving antimetabolites. The cumulative dose of irinotecan (5-9 cycles) increased hepatotoxicity by 8.5 times. However, the genotypes and phenotypes of UGT1A1*28/*6 failed to be predictive factors of hepatotoxicity. The findings of this study suggest that irinotecan-induced hepatotoxicity is not directly associated with genetic variables but is mostly related to concomitant use of CYP3A4 inducers and platinum, as well as the presence of liver metastasis and cardiovascular disease. Thus, close monitoring of liver function is recommended, especially in patients with liver impairment or using CYP3A inducers and platinum antineoplastic drugs, which may be the best way to prevent hepatotoxicity.

Simultaneous determination of linezolid and voriconazole serum concentrations using liquid chromatography-tandem mass spectrometry.

Linezolid and voriconazole are two antimicrobials used for severe infections in critically ill patients. Pharmacokinetics and pharmacodynamics are altered in critically ill patients. Therefore, standard dosing of anti-infective agents may not reach the optimal therapeutic targets. A rapid and simple liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for simultaneous determination of linezolid and voriconazole in human serum only 3 min after one-step protein precipitation pretreatment to monitor their concentrations. Multiple-reaction monitoring (MRM) mode was used for detection. The calibration curves were linear over the range of 0.5-100 µg/mL for both linezolid and voriconazole, with regression coefficients above 0.9900 for all analytes. The intra- and interday coefficients of variation were below 15% at all concentration levels (LLOQ/LQC/MQC/HQC). This method was successfully applied to routine therapeutic drug monitoring (TDM) for critically ill patients and other patients in need.