Klebsiella pneumoniae infections after liver transplantation: Drug resistance and distribution of pathogens, risk factors, and influence on outcomes.

BACKGROUND: Liver transplantation (LT) is the only curative treatment for end-stage liver disease. However, LT recipients are susceptible to infection, which is the leading cause of early mortality after LT. Klebsiella pneumoniae infections (KPIs) in the bloodstream are common in LT recipients. We hypothesized that KPIs and carbapenem-resistant Klebsiella pneumoniae (CRKP) infections may affect the outcomes of LT recipients. AIM: To assess KPI incidence, timing, distribution, drug resistance, and risk factors following LT and its association with outcomes. METHODS: This retrospective study included 406 patients undergoing LT at The Third Xiangya Hospital of Central South University, a tertiary hospital, from January 2015 to January 2023. We investigated the risk factors for KPIs and assessed the impact of KPIs and CRKP infections on the prognosis of LT recipients using logistic regression analysis. RESULTS: KPI incidence was 7.9% (n = 32), with lung/thoracic cavity the most frequent site of infection; the median time from LT to KPI onset was 7.5 d. Of 44 Klebsiella pneumoniae isolates, 43 (97.7%) and 34 (77.3%) were susceptible to polymyxin B or ceftazidime/avibactam and tigecycline, respectively; > 70% were resistant to piperacillin/ tazobactam, ceftazidime, cefepime, aztreonam, meropenem, and levofloxacin. Female sex [odds ratio (OR) = 2.827, 95% confidence interval (CI): 1.256-6.364; P = 0.012], pre-LT diabetes (OR = 2.794, 95%CI: 1.070-7.294; P = 0.036), day 1 post-LT alanine aminotransferase (ALT) levels ≥ 1500 U/L (OR = 3.645, 95%CI: 1.671-7.950; P = 0.001), and post-LT urethral catheter duration over 4 d (OR = 2.266, 95%CI: 1.016-5.054; P = 0.046) were risk factors for KPI. CRKP infections, but not KPIs, were risk factors for 6-month all-cause mortality post-LT. CONCLUSION: KPIs occur frequently and rapidly after LT. Risk factors include female sex, pre-LT diabetes, increased post-LT ALT levels, and urethral catheter duration. CRKP infections, and not KPIs, affect mortality.

Nomogram to predict gas-related complications during transoral endoscopic resection of upper gastrointestinal submucosal lesions: Clinical significance.

Transoral endoscopic resections in treating upper gastrointestinal submucosal lesions have the advantages of maintaining the integrity of the gastrointestinal lumen, avoiding perforation and reducing gastrointestinal fistulae. They are becoming more widely used in clinical practice, but, they may also present a variety of complications. Gas-related complications are one of the most common, which can be left untreated if the symptoms are mild, but in severe cases, they can lead to rapid changes in the respiratory and circulatory systems in a short period, which can be life-threatening. Therefore, it is important to predict the occurrence of gas-related complications early and take preventive measures actively. Based on the authors' results in the prepublication of the article "Nomogram to predict gas-related complications during transoral endoscopic resection of upper gastrointestinal submucosal lesions," and in conjunction with our evaluation and additions to the relevant content, radiographs may help screen patients at high risk for gas-related complications. Controlling blood glucose levels, shortening the duration of surgery, and choosing the most appropriate surgical resection may positively impact the prognosis of patients at high risk for gas-related complications during transoral endoscopic resection of upper gastrointestinal submucosal lesions.

The influence of delirium on mortality and length of ICU stay and analysis of risk factors for delirium after liver transplantation.

Objective: To analyze the incidence, timing, risk factors and prognosis of delirium after liver transplantation (LT). Methods: The clinical data of 321 patients undergoing LT in the Third Xiangya Hospital of Central South University from January 2018 to December 2022 were collected to investigate the incidence, onset, and risk factors for post-LT delirium and the impact of delirium on LT recipients' prognosis by statistical analysis. Results: The incidence of post-LT delirium was 19.3% (62/321), and the median interval between LT and onset of delirium was 20.1 h. Univariate analysis showed that pre-LT variables (Model for End Stage Liver Disease (MELD) score, hospital stay, hepatic encephalopathy, infection, white blood cell (WBC) count, lymphocyte count, abnormal potassium, lactulose use), intraoperative variables (red blood cell transfusion, remimazolam use, dexmedetomidine use) and post-LT variables (hypernatraemia, acute rejection, reoperation, basiliximab use, tacrolimus concentration) were associated with post-LT delirium. Multivariate logistic regression analysis revealed that MELD score at LT ≥22 [OR = 3.400, 95% CI:1.468-7.876, p = 0.004], pre-LT hepatic encephalopathy [OR = 3.224, 95% CI:1.664-6.244, p = 0.001], infection within 2 months prior to LT [OR = 2.238, 95% CI:1.151-4.351, p = 0.018], acute rejection [OR = 2.974, 95% CI:1.322-6.690, p = 0.008], and reoperation [OR = 11.919, 95% CI:2.938-48.350, p = 0.001] were independent risk factors for post-LT delirium. Post-LT delirium was reduced in LT recipients exposing to intraoperative remimazolam [OR = 0.287, 95% CI: 0.113-0.733, p = 0.009] or ≥ 25 µg of intraoperative dexmedetomidine [OR = 0.441, 95% CI 0.225-0.867, p = 0.018]. As for clinical outcomes, patients with delirium had a higher percentage of staying at the (ICU) ≥7 d after LT than those without delirium [OR = 2.559, 95% CI 1.418-4.617, p = 0.002]. Conclusion: The incidence of delirium was high and the onset of delirium was early after LT. Risk factors for post-LT delirium included high MELD score at LT, pre-LT hepatic encephalopathy and infections, acute rejection and reoperation. Intraoperative use of remimazolam or dexmedetomidine reduced post-LT delirium. Delirium had a negative impact on the length of ICU stay.

Insulin reverses impaired alveolar fluid clearance in ARDS by inhibiting LPS-induced autophagy and inflammatory.

Until now, acute respiratory distress syndrome (ARDS) has been a difficult clinical condition with a high mortality and morbidity rate, and is characterized by a build-up of alveolar fluid and impaired clearance. The underlying mechanism is not yet fully understood and no effective medications available. Autophagy activation is associated with ARDS caused by different pathogenic factors. It represents a new direction of prevention and treatment of ARDS to restrain autophagy to a reasonable level through pharmacological and molecular genetic methods. Na, K-ATPase is the main gradient driver of pulmonary water clearance in ARDS and could be degraded by the autophagy-lysosome pathway to affect its abundance and enzyme activity. As a normal growth hormone in human body, insulin has been widely used in clinical for a long time. To investigate the association of insulin with Na, K-ATPase, autophagy and inflammatory markers in LPS-treated C57BL/6 mice by survival assessment, proteomic analysis, histologic examination, inflammatory cell counting, myeloperoxidase, TNF-α and IL-1ß activity analysis etc. This was also verified on mouse alveolar epithelial type II (AT II) and A549 cells by transmission electron microscopy. We found that insulin restored the expression of Na, K-ATPase, inhibited the activation of autophagy and reduced the release of inflammatory factors caused by alveolar epithelial damage. The regulation mechanism of insulin on Na, K-ATPase by inhibiting autophagy function may provide new drug targets for the treatment of ARDS.

Characteristics of Gram-positive cocci infection and the therapeutic effect after liver transplantation. / è‚ç§»æ¤æœ¯åŽé©å °æ°é˜³æ€§çƒèŒçš„æ„ŸæŸ“ç‰¹ç‚¹åŠé˜²æ²»æ•ˆæžœ.

OBJECTIVES: Gram-positive cocci is the main pathogen responsible for early infection after liver transplantation (LT), posing a huge threat to the prognosis of liver transplant recipients. This study aims to analyze the distribution and drug resistance of Gram-positive cocci, the risk factors for infections and efficacy of antibiotics within 2 months after LT, and to guide the prevention and treatment of these infections. METHODS: In this study, data of pathogenic bacteria distribution, drug resistance and therapeutic efficacy were collected from 39 Gram-positive cocci infections among 256 patients who received liver transplantation from donation after citizens' death in the Third Xiangya Hospital of Central South University from January 2019 to July 2022, and risk factors for Gram-positive cocci infection were analyzed. RESULTS: Enterococcus faecium was the dominant pathogenic bacteria (33/51, 64.7%), followed by Enterococcus faecalis (11/51, 21.6%). The most common sites of infection were abdominal cavity/biliary tract (13/256, 5.1%) and urinary tract (10/256, 3.9%). Fifty (98%) of the 51 Gram-positive cocci infections occurred within 1 month after LT. The most sensitive drugs to Gram-positive cocci were teicoplanin, tigecycline, linezolid and vancomycin. Vancomycin was not used in all patients, considering its nephrotoxicity. Vancomycin was not administered to all patients in view of its nephrotoxicity.There was no significant difference between the efficacy of daptomycin and teicoplanin in the prevention of cocci infection (P>0.05). Univariate analysis indicated that preoperative Model for End-Stage Liver Disease (MELD) score >25 (P=0.005), intraoperative red blood cell infusion ≥12 U (P=0.013) and exposure to more than 2 intravenous antibiotics post-LT (P=0.003) were related to Gram-positive cocci infections. Multivariate logistic regression analysis revealed that preoperative MELD score >25 (OR=2.378, 95% CI 1.124 to 5.032, P=0.024) and intraoperative red blood cell transfusion ≥ 12 U (OR=2.757, 95% CI 1.227 to 6.195, P=0.014) were independent risk factors for Gram-positive cocci infections after LT. Postoperative Gram-positive cocci infections were reduced in LT recipients exposing to more than two intravenous antibiotics post-LT (OR=0.269, 95% CI 0.121 to 0.598, P=0.001). CONCLUSIONS: Gram-positive cocci infections occurring early after liver transplantation were dominated by Enterococcus faecalis infections at the abdominal/biliary tract and urinary tract. Teicoplanin, tigecycline and linezolid were anti-cocci sensitive drugs. Daptomycin and teicoplanin were equally effective in preventing cocci infections due to Gram-positive cocci. Patients with high preoperative MELD score and massive intraoperative red blood cell transfusion were more likely to suffer Gram-positive cocci infection after surgery. Postoperative Gram-positive cocci infections were reduced in recipients exposing to more than two intravenous antibiotics post-LT.

Risk factors of early bacterial infection and analysis of bacterial composition, distribution and drug susceptibility after cadaveric liver transplantation.

BACKGROUND: This study provided a theoretical basis for the clinical diagnosis and treatment of bacterial infection after liver transplantation through analyzing the pathogenic distribution, drug sensitivity and risk factors of bacterial infection after liver transplantation. METHODS: We collected clinical data from 207 recipients undergoing liver transplantation of graft from donation after citizens' death donors in the Third Xiangya Hospital of Central South University from January 2019 to December 2021 and analyzed the composition and distribution of bacterial pathogens, drug resistance and risk factors of infection. RESULTS: A total of 90 bacterial infections occurred in 55 recipients within two months after liver transplantation, and the incidence of bacterial infection was 26.6% (55/207). The gram-negative bacteria (46/90, 51.1%) were more prevalent than gram-positive bacteria (44/90, 48.9%). Common sites of infection were the abdominal/biliary tract (26/90, 28.9%), lung (22/90, 22.4%) and urinary tract (22/90, 22.4%). Fourteen cases (6.8%) died after liver transplantation. Klebsiella pneumoniae (17/90, 18.9%) was the most frequent gram-negative bacteria causing infection in liver transplant recipients and 58.7%, 50%, 80.4% and 89.1% of gram-negative bacteria were sensitive to amikacin, minocycline, tigecycline and polymyxin B, respectively. The most common gram-positive bacteria was Enterococcus faecium (30/90, 33.3%) and 97.7%, 100%, 86.4%, 100% and 100% of gram-positive bacteria were sensitive to vancomycin, teicoplanin, daptomycin, tigecycline and linezolid, respectively. Univariate analysis revealed that bacterial infection was associated with female, age (≥ 50 years old), preoperative albumin (≤ 30 g/L), operation duration (≥ 400 min), intraoperative blood loss (≥ 3000 ml) and postoperative ventilator support. Binary Logistic regression analysis showed that female (OR = 3.149, 95% CI: 1.418-6.993, P = 0.005), operation duration (≥ 400 min) (OR = 2.393, 95% CI: 1.202-4.765, P = 0.013) and intraoperative blood loss (≥ 3000 ml) (OR = 2.052, 95% CI: 1.007-4.183, P = 0.048) were independent risk factors for bacterial infection after liver transplantation. CONCLUSION: The incidence of early bacterial infection after liver transplantation was high, and the infection sites were mainly abdominal/biliary tract, respiratory tract and urinary tract. The most common pathogenic bacterium was gram-negative bacterium. Our study also identified several independent risk factors for bacterial infection after liver transplantation, including female gender, operation duration of 400 min or more, and intraoperative blood loss of 3000 ml or more. By addressing these risk factors, such as implementing strategies to optimize surgical procedures and minimize blood loss, healthcare professionals can work towards reducing the incidence of bacterial infections following liver transplantation.

[Risk Factors and Prognosis of Delirium After Liver Transplantation].

Objective: To analyze the incidence, the onset time, and the risk factors of delirium after liver transplantation (LT). Methods: The clinical data of 211 patients who underwent LT at Third Xiangya Hospital, Central South University between January 2019 and December 2021 were collected to investigate the incidence and the onset time of postoperative delirium. Univariate analysis and multivariate logistic regression analysis were conducted to analyze the risk factors of delirium and to analyze the effect of delirium on clinical outcomes. Results: The incidence of delirium was 20.4% (43/211) and the median interval between LT and the onset of delirium was 19 hours. Univariate analysis showed that the preoperative Model for End-Stage Liver Disease (MELD) score≥22, preoperative length-of-stay≥7, liver cancer, preoperative hepatic encephalopathy, infections within 2 months before LT, preoperative lymphocyte value<0.5×10 9 L －1, massive amount of intraoperative red blood cell infusion, and carbapenem antibiotics use for 3 days or longer were associated with postoperative delirium. Multivariate logistic regression analysis showed that preoperative infections within 2 months before LT (odds ratio [ OR]=2.597, 95% confidence interval [ CI]: 1.135-5.944, P=0.024), preoperative MELD score≥22 ( OR=2.967, 95% CI: 1.104-7.975, P=0.031), and preoperative hepatic encephalopathy ( OR=4.700, 95% CI: 2.043-10.602, P<0.001) were independent risk factors for delirium after LT, while carbapenems antibiotics use for 3 days or longer ( OR=0.192, 95% CI: 0.083-0.441, P<0.001) was a protective factor for postoperative delirium among LT recipients. Regarding clinical outcomes, patients with delirium had longer postoperative ICU length-of-stays than those without delirium did ( P=0.025). Conclusion: There is a high incidence of postoperative delirium among patients who undergo LT and the onset time of delirium after LT is early. Risk factors include preoperative infections, high MELD score, and hepatic encephalopathy. On the other hand, the use of carbapenems can help prevent delirium.

The application of metagenomic next-generation sequencing in patients with infection or colonization caused by Lichtheimia species.

Background: Mucormycosis is considered the fourth most common invasive fungal disease after candidiasis, aspergillosis and cryptococcosis. Lichtheimia species accounted for 5%-29% of all mucormycosis. However, available data on species-specific analysis of Lichtheimia infections are limited. Methods: This study included nine patients hospitalized in five hospitals in two cities in south China with mucormycosis or colonization caused by Lichtheimia species, diagnosed mainly by metagenomic next-generation sequencing (mNGS). The corresponding medical records were reviewed, and the clinical data analyzed included demographic characteristics, site of infection, host factors and type of underlying disease, diagnosis, clinical course, management, and prognosis. Results: In this study, nine patients with Lichtheimia infections or colonization had a recent history of haematological malignancy (33.3%), solid organ transplants (33.3%), pulmonary disease (22.2%), and trauma (11.1%) and were categorized as 11.1% (one case) proven, 66.7% (six cases) probable mucormycosis and 22.2% (two cases) colonization. Pulmonary mucormycosis or colonization was the predominant presentation in 77.8% of cases and mucormycosis caused by Lichtheimia resulted in death in four out of seven patients (57.1%). Conclusion: These cases highlight the importance of early diagnosis and combined therapy for these sporadic yet life-threatening infections. Further studies on the diagnosis and control of Lichtheimia infection in China are required.

Pathogen distribution and risk factors of bacterial and fungal infections after liver transplantation. / è‚ç§»æ¤æœ¯åŽæ—©æœŸç»†èŒä¸ŽçœŸèŒæ„ŸæŸ“ç— åŽŸä½“åˆ†å¸ƒåŠå±é™©å› ç´ .

OBJECTIVES: Liver transplant recipients have a high rate of postoperative infection, and identification of patients at high risk for bacterial and fungal infections will help prevent disease and improve long-term outcomes for them. This study aims to understand the composition, distribution, prognosis of bacterial and fungal infections within 2 months after liver transplantation and to analyze their risk factors. METHODS: The data of pathogen composition, distribution, and prognosis of bacterial and fungal infections among liver transplant recipients in the Third Xiangya Hospital of Central South University from May 2020 to October 2021 were collected, and the risk factors for these infections were analyzed. RESULTS: A total of 106 episodes of bacterial or fungal infections occurred in 71.4% of liver transplant recipients (75/105). Gram-negative bacteria were the dominant pathogenic bacteria (49/106, 46.2%), followed by Gram-positive bacteria (31/106, 29.2%). The most common Gram-negative bacterium was Acinetobacter baumannii (13/106, 12.3%). The most common Gram-positive bacterium was Enterococcus faecium (20/106, 18.9%). The most common infections were pulmonary (38/105, 36.2%) and multiple site infections (30/105, 28.6%). Six (6/105, 5.7%) patients with infections died within 2 months after liver transplantation. Univariate analysis showed that the model for end-stage liver disease (MELD) score ≥25, antibiotic use within half a month before transplantation, infections within 2 months prior to transplantation, intraoperative red blood cell infusion≥8 U, indwelling urinary tract catheter ≥4 days after transplantation, and the dosage of basiliximab use ≥40 mg were associated with infections. Multivariate logistic regression analysis revealed that only infections within 2 months prior to transplantation (OR=5.172, 95% CI 1.905-14.039, P<0.01) was an independent risk factor for bacterial and fungal infections after liver transplantation. Postoperative bacterial and fungal infections were reduced in liver transplant recipients receiving basiliximab ≥40 mg (OR=0.197, 95% CI: 0.051-0.762, P<0.05). CONCLUSIONS: The incidence of bacterial and fungal infections is high in the early stage after liver transplantation, and the mortality after infection is significantly higher than that of non-infected patients. The most common infection is respiratory infection, and the dominant pathogens is Gram-negative bacteria. Patients infected within 2 months prior to liver transplantation are prone to bacterial and fungal infections. Standard use of basiliximab can reduce the incidence of infections after liver transplantation.

Identification of different proteins binding to Na, K-ATPase α1 in LPS-induced ARDS cell model by proteomic analysis.

BACKGROUND: Acute respiratory distress syndrome (ARDS) is characterized by refractory hypoxemia caused by accumulation of pulmonary fluid, which is related to inflammatory cell infiltration, impaired tight junction of pulmonary epithelium and impaired Na, K-ATPase function, especially Na, K-ATPase α1 subunit. Up until now, the pathogenic mechanism at the level of protein during lipopolysaccharide- (LPS-) induced ARDS remains unclear. METHODS: Using an unbiased, discovery and quantitative proteomic approach, we discovered the differentially expressed proteins binding to Na, K-ATPase α1 between LPS-A549 cells and Control-A549 cells. These Na, K-ATPase α1 interacting proteins were screened by co-immunoprecipitation (Co-IP) technology. Among them, some of the differentially expressed proteins with significant performance were identified and quantified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Data are available via ProteomeXchange with identifier PXD032209. The protein interaction network was constructed by the related Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. Several differentially expressed proteins were validated by Western blot. RESULTS: Of identified 1598 proteins, 89 were differentially expressed proteins between LPS-A549 cells and Control-A549 cells. Intriguingly, protein-protein interaction network showed that there were 244 significantly enriched co-expression among 60 proteins in the group control-A549. while the group LPS-A549 showed 43 significant enriched interactions among 29 proteins. The related GO and KEGG analysis found evident phenomena of ubiquitination and deubiquitination, as well as the pathways related to autophagy. Among proteins with rich abundance, there were several intriguing ones, including the deubiquitinase (OTUB1), the tight junction protein zonula occludens-1 (ZO-1), the scaffold protein in CUL4B-RING ubiquitin ligase (CRL4B) complexes (CUL4B) and the autophagy-related protein sequestosome-1 (SQSTM1). CONCLUSIONS: In conclusion, our proteomic approach revealed targets related to the occurrence and development of ARDS, being the first study to investigate significant differences in Na, K-ATPase α1 interacting proteins between LPS-induced ARDS cell model and control-A549 cell. These proteins may help the clinical diagnosis and facilitate the personalized treatment of ARDS.

Drug Resistance and Risk Factors for Acquisition of Gram-Negative Bacteria and Carbapenem-Resistant Organisms Among Liver Transplant Recipients.

INTRODUCTION: Infections caused by Gram-negative bacteria, in particular carbapenem-resistant organisms (CRO), pose a great threat to liver transplant (LT) recipients. Understanding the risk factors for Gram-negative and CRO infections and the drug resistance of corresponding bacteria will help guide the prevention and treatment of these infections. METHODS: Data on the composition, distribution and drug resistance of Gram-negative bacteria and CRO among LT recipients were collected. The risk factors for Gram-negative and CRO infections were identified via univariate and multivariate analysis. RESULTS: A total of 45 episodes of Gram-negative infection, including 20 episodes of CRO infection, occurred in 19.9% (27/136) of LT recipients. Klebsiella pneumoniae was the dominant pathogenic bacteria (14/45; 31.1%). The most common site of infection was the abdominal cavity/bile duct (11/27; 40.7%). Eleven (8.1%) patients died within 2 months after LT, and two deaths were related to Gram-negative infection. Gram-negative bacteria were relatively sensitive to tigecycline and polymyxin B, with resistance of 26.7 and 11.1%, respectively. CRO had lower resistance to ceftazidime/avibactam (45.5%) and polymyxin B (10%). A univariate analysis showed that male sex, infection within 2 months prior to LT, duration of surgery ≥ 400 min, reoperation, indwelling urethral catheter use ≥ 3 days and elevated alanine aminotransferase on day 1 post-LT were associated with Gram-negative infection. Multivariate logistic regression analysis revealed that infection within 2 months prior to LT [odds ratio (OR) = 4.426, 95%CI: 1.634-11.99, P = 0.003], duration of surgery ≥ 400 min [OR = 3.047, 95%CI: 1.194-7.773, P = 0.02] and indwelling urethral catheter use ≥ 3 days [OR = 5.728, 95%CI: 1.226-26.763, P = 0.026] were independent risk factors for Gram-negative infection after LT, and that only carbapenem use ≥ 3 days within 15 days prior to infection [OR = 14, 95%CI: 1.862-105.268, P = 0.01] was related to the occurrence of CRO infections. CONCLUSION: The incidence of Gram-negative and CRO infections was high in the early post-LT period. The most common infection site was the abdominal cavity/bile duct, and the dominant pathogen was K. pneumoniae. Patients with infections within 2 months prior to LT, prolonged surgery time or delayed urethral catheter removal were prone to Gram-negative infection. Carbapenem exposure was correlated with CRO infections.

Insulin alleviates LPS-induced ARDS via inhibiting CUL4B-mediated proteasomal degradation and restoring expression level of Na,K-ATPase α1 subunit through elevating HCF-1.

Acute respiratory distress syndrome (ARDS) is a critical disease with a high mortality rate, characterized by obstinate hypoxemia caused by accumulation of alveolar fluid and excessive uncontrolled inflammation. Na,K-ATPase α1 (ATP1A1) subunit is an important component of Na,K-ATPase that transports Na+ and K+ and scavenges alveolar fluid. The function of Na,K-ATPase is always impaired during ARDS and results in more severe symptoms of ARDS. However, the regulatory mechanism of Na,K-ATPase after ARDS remains unclear. Here, we revealed ATP1A1 was downregulated post-transcriptionally by an E3 ligase component CUL4B mediated proteasomal degradation. Moreover, we found insulin could inhibit the upregulation of CUL4B in an insulin receptor cofactor HCF-1-dependent manner. Our study resolved the molecular mechanism underlying the clearance impairment of alveolar fluid and provided a clue for the usage of insulin as a potential therapeutic medicine for ARDS.

[Research advances on the role of Na+-K+-ATPase regulation in pulmonary edema clearance of acute respiratory distress syndrome].

Acute respiratory distress syndrome (ARDS) is a critical disease with high mortality, and currently there is no specific treatment. ARDS is characterized by refractory hypoxemia secondary to pulmonary edema, but the underlying mechanism is not yet fully understood. Alveolar edema fluid is mainly actively transported and reabsorbed by sodium-water transport system. The sodium pump (Na+-K+-ATPase-mediated Na+ transport) on the basal side of type II alveolar epithelial cells (AT II) is the main driving force for pulmonary edema clearance. Na+-K+-ATPase regulation is affected by many regulatory factors through a variety of ways, among which "long-term regulation" mechanism plays an important role, including positively regulating the gene transcription and protein expression of Na+-K+-ATPase. Na+-K+-ATPase can also be degraded by ubiquitin-proteasome pathway (UPP) and autophagy lysosome pathway to affect its abundance and enzyme activity, meanwhile, Na+-K+-ATPase α1 plays a key role in sodium water transport. We review the "long-term regulation" mechanism of Na+-K+-ATPase related pathways in pulmonary edema clearance and explore the possibility of new therapies for ARDS based on this mechanism, so as to provide new targets for the treatment of ARDS.

Regulatory effect of insulin on the structure, function and metabolism of Na+/K+-ATPase (Review).

Na+/K+-ATPase is an ancient enzyme, the role of which is to maintain Na+ and K+ gradients across cell membranes, thus preserving intracellular ion homeostasis. The regulation of Na+/K+-ATPase is affected by several regulatory factors through a number of pathways, with hormones serving important short-term and long-term regulatory functions. Na+/K+-ATPase can also be degraded through activation of the ubiquitin proteasome and autophagy-lysosomal pathways, thereby affecting its abundance and enzymatic activity. As regards the regulatory effect of insulin, it has been found to upregulate the relative abundance of Na+/K+-ATPase and restore the transport efficiency in multiple in vitro and in vivo experiments. Therefore, elucidating the role of insulin in the regulation Na+/K+-ATPase may help uncover new drug targets for the treatment of related diseases. The aim of the present study was to review the structure and function of Na+/K+-ATPase and to discuss the possible mechanisms through which it may be regulated by insulin, in order to investigate the possibility of designing new therapies for related diseases.

Impact of Donor-Derived Multi-drug-Resistant Organism Infections on Abdominal Solid Organ Transplantation Recipients in China.

BACKGROUND: Infection with multi-drug-resistant organisms (MDROs) is a life-threatening disease among abdominal solid organ transplantation recipients. Reports of donor-derived (DD) MDRO infections were few, but adverse clinical outcomes were severe, such as death or graft loss. METHODS: The medical records of 68 donation after citizens' death donors with MDRO infections and 20 recipients transmitted with infections between October 1, 2015, and September 1, 2020, were reviewed according to the Declaration of Helsinki and the Declaration of Istanbul. There were no grafts from prisoners, and no donors were not coerced or paid. RESULTS: Prevalence and mortality of DD-MDRO infection among abdominal solid organ transplantation recipients were 2.3% and 18.1%, respectively. The prevalence rate of DD-MDR gram-negative bacterial infection was higher than that of gram-positive bacterial infection (1.7% vs 0.6%). Negative culture of specimens occurred in 9 of 68 donors. Recipients with DD-MDR gram-negative bacterial infections had a significantly lower survival rate compared with DD-MDR gram-positive bacterial infections (P = .046). CONCLUSIONS: Donation after citizens' death donors and recipients had high MDRO infection rates, and gram-negative bacteria were the predominant pathogens. When a possible DD-MDRO infection occurs, there may be adverse outcomes with limited choice of antibiotics. A nationwide surveillance and communication network needs to be established in China.

Application of metagenomic next-generation sequencing in the diagnosis and treatment guidance of Pneumocystis jirovecii pneumonia in renal transplant recipients.

Pneumocystis jirovecii pneumonia (PJP) is difficult to be diagnosed, so this study explored if PJP could be diagnosed by metagenomic next-generation sequencing (mNGS) and if mNGS could guide the therapy of PJP. mNGS was successfully diagnosed 13 out of 14 PJP recipients with 11 through peripheral blood samples, verified by PCR. Ten non-PJP recipients were enrolled as the control group. Blood tests revealed a high ß-D-glucan (BDG) level in all recipients with PJP during the hospitalization. Four (28.6%) of 14 PJP patients were infected with cytomegalovirus simultaneously, while 8 (57.1%) suffered from a combined infection caused by Torque teno virus. Five (35.7%) of 14 cases died of PJP or the subsequent bacteremias/bacterial pneumonia with a longer interval between the onset and diagnosis of/the available therapy against PJP than survival cases. Univariate analysis of characteristics between PJP and non-PJP recipients revealed that BDG assays was higher at the admission in PJP group (P =0.011). This present study supports the value of mNGS detection of blood sample in diagnosing PJP, which could assist clinical decision for therapy against PJ and improve outcome of PJP. The study also highlights the sensitivity of BDG assays. Cytomegalovirus and Torque teno virus infections often occur at the same time of PJP, thus can be alerts of PJP.

Non-targeted proteomics of acute respiratory distress syndrome: clinical and research applications.

Acute respiratory distress syndrome (ARDS) is characterized by refractory hypoxemia caused by accumulation of pulmonary fluid with a high mortality rate, but the underlying mechanism is not yet fully understood, causing absent specific therapeutic drugs to treat with ARDS. In recent years, more and more studies have applied proteomics to ARDS. Non-targeted studies of proteomics in ARDS are just beginning and have the potential to identify novel drug targets and key pathways in this disease. This paper will provide a brief review of the recent advances in the application of non-targeted proteomics to ARDS.

Epidemiology, Susceptibility, and Risk Factors Associated with Mortality in Carbapenem-Resistant Gram-Negative Bacterial Infections Among Abdominal Solid Organ Transplant Recipients: A Retrospective Cohort Study.

INTRODUCTION: Carbapenem-resistant gram-negative bacteria (CR-GNB) can cause life-threatening infections among abdominal solid organ transplantation (ASOT) recipients. This study aimed to investigate the epidemiology and drug susceptibility of CR-GNB pathogens and identity the risk factors associated with 90-day crude mortality of CR-GNB infections among ASOT recipients. METHODS: We retrospectively reviewed the clinical characteristics, drug resistance rate, and risk factors associated with mortality in CR-GNB infections among ASOT recipients between August 1, 2013, and August 1, 2020. The Cox regression model was performed to identify the independent risk factors for mortality. RESULTS: During the 8-year period, CR-GNB infections occurred in 153 of 1452 (10.5%) recipients, and 23 of 153 (15.0%) patients died. The most common pathogen was Acinetobacter baumannii (n = 47). The drug resistance rate of CR-GNB pathogens was relatively low to tigecycline (33.3%) and high to other categories (> 60%). There was a significant increasing trend in drug resistance to tigecycline as time went on (from 24 to 40%, P = 0.04). The independent risk factors for mortality were mechanical ventilation (hazard ratio 7.40, 95% confidence interval 2.69-20.38, P < 0.001), septic shock (hazard ratio 7.41, 95% confidence interval 2.86-19.23, P < 0.001), and platelet count < 50,000/mm3 (hazard ratio 4.00, 95% confidence interval 1.49-10.76, P = 0.006). CONCLUSION: CR-GNB is widespread with high prevalence and mortality rates among ASOT recipients. Mechanical ventilation, septic shock, and low platelet count represent three independent risk factors related to the mortality of ASOT recipients with CR-GNB infection. We suggest that tigecycline may be used under rigorous management because of the significant increasing risk of drug resistance.

Predictors of Mortality During Initial Liver Transplant Hospitalization and Investigation of Causes of Death.

BACKGROUND Liver transplant (LT) remains a life-saving procedure with a high mortality rate. The present study investigated the causes of death and sought to identify predictive factors of mortality during the initial LT hospitalization. MATERIAL AND METHODS We retrieved data on first-time adult recipients who underwent LT between November 2017 and October 2019 receiving grafts from donation after citizen's death. The risk factors for mortality during the initial LT hospitalization were confirmed by univariate analysis. We also analyzed the causes of death. RESULTS We enrolled 103 recipients, including 86 males and 17 females, with a mean age of 47.7 years. Thirty-eight (36.9%) recipients were labeled as non-cholestatic cirrhosis-related indications. Approximately 8% of all recipients had diabetes prior to LT. Induction therapy was used in 11 (10.7%) recipients, along with maintenance therapy. The median model for end-stage liver disease score at LT was 32.4 (21.4-38.4). The in-hospital mortality rate of LT recipients was 6.8% (7/103), and infections were responsible for most of the deaths (6/7). The 1 remaining death resulted from primary graft failure. Univariate analysis showed recipients with postoperative pneumonia (p2 mg/dL, and alanine transaminase on day 1 after LT >1800 µmol/L (all P<0.001) were much more likely to die. CONCLUSIONS In-hospital mortality of LT recipients was high, due in large part to infections. Acute hepatic necrosis, prolonged post-transplant ICU stays, certain types of postoperative infections, and postoperative liver and kidney dysfunction were potential risk factors for in-hospital mortality of LT recipients.

Risk Factors for Acquisition of Carbapenem-Resistant Klebsiella pneumoniae and Mortality Among Abdominal Solid Organ Transplant Recipients with K. pneumoniae Infections.

BACKGROUND For abdominal solid organ transplant (ASOT) recipients, infection with Klebsiella pneumoniae, particularly carbapenem-resistant K. pneumoniae (CRKP), can be life-threatening. The aims of this study were to characterize the risk factors associated with acquisition of CRKP and 90-day crude mortality among patients. MATERIAL AND METHODS In our cohort study, we retrospectively reviewed 68 K. pneumoniae-infected transplant recipients, studied their demographics, clinical manifestations, microbiology, and outcomes, and determined the risk factors associated with the occurrence of CRKP and crude mortality due to K. pneumoniae infections. RESULTS Sixty-eight ASOT recipients (5.4%) experienced 78 episodes of K. pneumoniae infection. Among these, 20 patients (29.4%) died. The independent risk factors associated with mortality were multiple infected organs or sites (odds ratio=22.034, 95% confidence intervals=4.348-111.653, P=0.001) and septic shock (odds ratio=27.090, 95% confidence intervals=1.841-398.512, P=0.016). Risk factors associated with acquisition of CRKP were multiple infected organs or sites (odds ratio=3.056, 95% confidence intervals=1.091-8.556, P=0.033). CONCLUSIONS K. pneumoniae infections, especially CRKP, frequently occurred among ASOT recipients, with a high mortality rate. Multiple infected organs or sites and septic shock were predictors of crude mortality caused by K. pneumoniae infections, while CRKP infections were associated with multiple infected organs or sites. Greater efforts are needed towards improved antibiotic administration, early diagnosis and precise treatment, recognition of septic shock, and reduced length of hospitalization.