Shuai Ma

Salmonella Typhimurium establishes systemic infection by replicating in host macrophages. Here we show that macrophages infected with S. Typhimurium exhibit upregulated glycolysis and decreased serine synthesis, leading to accumulation of glycolytic intermediates. The effects on serine synthesis are mediated by bacterial protein SopE2, a type III secretion system (T3SS) effector encoded in pathogenicity island SPI-1. The changes in host metabolism promote intracellular replication of S. Typhimurium via two mechanisms: decreased glucose levels lead to upregulated bacterial uptake of 2- and 3-phosphoglycerate and phosphoenolpyruvate (carbon sources), while increased pyruvate and lactate levels induce upregulation of another pathogenicity island, SPI-2, known to encode virulence factors. Pharmacological or genetic inhibition of host glycolysis, activation of host serine synthesis, or deletion of either the bacterial transport or signal sensor systems for those host glycolytic intermediates impairs S. Typhimurium replication or virulence.

Abstract AKI is a common complication of sepsis and is significantly associated with mortality. Sepsis accounts for more than 50% of the cases of AKI , with a mortality rate of up to 40%. The pathogenesis of septic AKI is complex, but there is emerging evidence that, at least in the first 48 hours, the defects may be functional rather than structural in nature. For example, septic AKI is associated with an absence of histopathological changes, but with microvascular abnormalities and tubular stress. In this context, renal medullary hypoxia due to redistribution of intra‐renal perfusion is emerging as a critical mediator of septic AKI . Clinically, vasopressor drugs remain the cornerstone of therapy for maintenance of blood pressure and organ perfusion. However, in septic AKI , there is insensitivity to vasopressors such as norepinephrine, leading to persistent hypotension and organ failure. Vasopressin, angiotensin II , and, paradoxically, α 2 ‐adrenergic receptor agonists (clonidine and dexmedetomidine) may be feasible adjunct therapies for catecholamine‐resistant vasodilatory shock. In this review, we outline the recent progress made in understanding how these drugs may influence the renal microcirculation, which represents a crucial step toward developing better approaches for the circulatory management of patients with septic AKI .

In traditional electronic health records (EHRs), medical-related information is generally separately controlled by different hospitals and thus it leads to the inconvenience of information sharing. Cloud-based EHRs solve the problem of information sharing in the traditional EHRs. However, cloud-based EHRs suffer the centralized problem, i.e., cloud service center and key-generation center. This paper works on creating a new EHRs paradigm which can help in dealing with the centralized problem of cloud-based EHRs. Our solution is to make use of the emerging technology of blockchain to EHRs (denoted as blockchain-based EHRs for convenience). First, we formally define the system model of blockchain-based EHRs in the setting of consortium blockchain. In addition, the authentication issue is very important for EHRs. However, existing authentication schemes for blockchain-based EHRs have their own weak points. Therefore, in this paper, we also propose an authentication scheme for blockchain-based EHRs. Our proposal is an identity-based signature scheme with multiple authorities which can resist collusion attack out of N from N-1 authorities. Furthermore, our scheme is provably secure in the random oracle model and has more efficient signing and verification algorithms than existing authentication schemes of blockchain-based EHRs.

BACKGROUND: Shotgun metagenomic next-generation sequencing (mNGS) is widely used to detect pathogens in bronchoalveolar lavage fluid (BALF). However, mNGS is complex and expensive. This study explored the feasibility of targeted next-generation sequencing (tNGS) in distinguishing lower respiratory tract infections in clinical practice. METHODS: We used 229 retrospective BALF samples to establish thresholds and diagnostic values in a prospective cohort of 251 patients. After target pathogen selection, primer and probe design, optimization experiments, and bioinformatics analysis, multiplex PCR-based tNGS (mp-tNGS) and hybrid capture-based tNGS (hc-tNGS), targeting 198 and 3060 pathogens (DNA and RNA co-detection workflow) were established and performed. FINDINGS: mp-tNGS and hc-tNGS took 10.3 and 16 h, respectively, with low sequencing data sizes of 0.1 M and 1 M reads, and test costs reduced to a quarter and half of mNGS. The LoDs of mp-tNGS and hc-tNGS were 50-450 CFU/mL. mp-tNGS and hc-tNGS were highly accurate, with 86.5% and 87.3% (vs. 85.5% for mNGS) sensitivities and 90.0% and 88.0% (vs. 92.1% for mNGS) specificities. tNGS detection rates for casual pathogens were 84.3% and 89.5% (vs. 88.5% for mNGS), significantly higher than conventional microbiological tests (P < 0.001). In seven samples, tNGS detected Pneumocystis jirovecii, a fungus not detected by mNGS. Whereas mNGS detected six samples with filamentous fungi (Rhizopus oryzae, Aureobasidium pullulans, Aspergillus niger complex, etc.) which missed by tNGS. The anaerobic bacteria as pathogen in eight samples was failed to detect by mp-tNGS. INTERPRETATION: tNGS may offer a new, broad-spectrum, rapid, accurate and cost-effective approach to diagnosing respiratory infections. FUNDING: National Natural Science Foundation of China (81625014 and 82202535).

BACKGROUND: Animal and human studies suggest that inflammation and malnutrition are common in acute kidney injury (AKI) patients. However, only a few studies reported CRP, a marker of inflammation, albumin, prealbumin and cholesterol, markers of nutritional status were associated with the prognosis of AKI patients. No study examined whether the combination of inflammatory and nutritional markers could predict the mortality of AKI patients. METHODS: 155 patients with hospital-acquired AKI were recruited to this prospective cohort study according to RIFLE (Risk, Injury, Failure, Lost or End Stage Kidney) criteria. C-reactive protein (CRP), and the nutritional markers (albumin, prealbumin and cholesterol) measured at nephrology consultation were analyzed in relation to all cause mortality of these patients. In addition, CRP and prealbumin were also measured in healthy controls (n = 45), maintenance hemodialysis (n = 70) and peritoneal dialysis patients (n = 50) and then compared with AKI patients. RESULTS: Compared with healthy controls and end-stage renal disease patients on maintenance hemodialysis or peritoneal dialysis, patients with AKI had significantly higher levels of CRP/prealbumin (p < 0.001). Higher level of serum CRP and lower levels of albumin, prealbumin and cholesterol were found to be significant in the patients with AKI who died within 28 days than those who survived >28 days. Similarly, the combined factors including the ratio of CRP to albumin (CRP/albumin), CRP/prealbumin and CRP/cholesterol were also significantly higher in the former group (p < 0.001 for all). Multivariate analysis (Cox regression) revealed that CRP/prealbumin was independently associated with mortality after adjustment for age, gender, sepsis and sequential organ failure assessment (SOFA, p = 0.027) while the others (CRP, albumin, prealbumin, cholesterol, CRP/albumin and CRP/cholesterol) became non-significantly associated. The hazard ratio was 1.00 (reference), 1.85, 2.25 and 3.89 for CRP/prealbumin increasing according to quartiles (p = 0.01 for the trend). CONCLUSIONS: Inflammation and malnutrition were common in patients with AKI. Higher level of the ratio of CRP to prealbumin was associated with mortality of AKI patients independent of the severity of illness and it may be a valuable addition to SOFA score to independent of the severity of illness and it may be a valuable addition to SOFA score to predict the prognosis of AKI patients.