Early application of continuous high-volume haemofiltration can reduce sepsis and improve the prognosis of patients with severe burns.

BACKGROUND: In the early stage of severe burn, patients often exhibit a high level of inflammatory mediators in blood and are likely to develop sepsis. High-volume haemofiltration (HVHF) can eliminate these inflammatory mediators. We hypothesised that early application of HVHF may be beneficial in reducing sepsis and improving the prognosis of patients with severe burns. METHODS: Adults patients with burns ≥ 50% total burn surface area (TBSA) and in whom the sum of deep partial and full-thickness burn areas was ≥ 30% were enrolled in this randomised prospective study, and they were divided into control (41 cases) and HVHF (41 cases) groups. Patients in the control group received standard management for major burns, whereas the HVHF group additionally received HVHF treatment (65 ml/kg/h for 3 consecutive days) within 3 days after burn. The incidence of sepsis and mortality, some laboratory data, levels of inflammatory cytokines in the blood, HLA-DR expression on CD14+ peripheral blood monocytes, the proportion of CD25+Foxp3+ in CD4+ T lymphocytes, and the counts of CD3+, CD4+ and CD8+ T lymphocytes were recorded within 28 days post-burn. RESULTS: The incidence of sepsis, septic shock and duration of vasopressor treatment were decreased significantly in the HVHF group. In addition, in the subgroup of patients with burns ≥ 80% TBSA, the 90-day mortality showed significant decreases in the HVHF group. The ratio of arterial oxygen partial pressure to the fraction of inspiration oxygen was improved after HVHF treatment. In the patients who received HVHF treatment, the blood levels of inflammatory cytokines, including tumour necrosis factor-α, interleukin (IL)-1ß, IL-6 and IL-8, as well as the blood level of procalcitonin were found to be lower than in the control group. Moreover, higher HLA-DR expression on CD14+ monocytes and a lower proportion of CD25+Foxp3+ in CD4+ T lymphocytes were observed in the patients in the HVHF group. CONCLUSIONS: Early application of HVHF benefits patients with severe burns, especially for those with a greater burn area (≥ 80% TBSA), decreasing the incidence of sepsis and mortality. This effect may be attributed to its early clearance of inflammatory mediators and the recovery of the patient's immune status. TRIAL REGISTRATION: Chinese Clinical Trial Register, ChiCTR-TRC-12002616 . Registered on 24 October 2012.

Heat shock protein 90 inhibition by 17-Dimethylaminoethylamino-17-demethoxygeldanamycin protects blood-brain barrier integrity in cerebral ischemic stroke.

Metalloproteinase (MMP)9 plays a pivotal role in ischemic stroke induced blood brain barrier (BBB) disruption. Correlation between HSP90 and MMP9 in several diseases prompted us to evaluate the efficacy of HSP90 inhibition as a novel approach to protect BBB integrity in ischemic stroke. ELISA was used to detect HSP90α and MMP9 in serum samples of stroke patients, which showed that HSP90α significantly correlated with MMP9 among 63 serum samples of stroke patients. Male C57/BL6 mice were pretreated with 17-Dimethylaminoethylamino-17-demethoxygeldanamycin (17-DMAG) or vehicle before being subjected to transient occlusion of middle cerebral artery and reperfusion (MCAO). Infarction, neurological scores, Evans blue (EB) extravasation, inflammatory responses and tight junction protein expression were examined 24 h after MCAO. We also investigated if 17-DMAG protected BBB integrity by suppressing inflammation and MMP9 activation. Oxygen glucose deprivation (OGD) was performed on bEnd.3 cells to explore the mechanisms of HSP90 inhibition in inhibiting MMP9. The results demonstrated that infarct volume was reduced in 17-DMAG-treated mice compared to control group following MCAO. Neurological outcomes were greatly improved in 17-DMAG-treated mice. Inflammatory responses, MMP9 activity and EB extravasation were decreased by 17-DMAG. In addition, 17-DMAG inhibited nuclear factor kappa B (NF-κB) activation following MCAO. Furthermore, HSP90 inhibition decreased NF-κB dependent MMP9 expression in bEnd.3 after OGD /reoxygenation. These findings suggested that HSP90 could be a novel therapeutic target in BBB breakdown during ischemic stroke. As several HSP90 inhibitors are in clinical trials for cancer, these findings have translational implications.

Discovery of Novel Inhibitors and Fluorescent Probe Targeting NAMPT.

Nicotinamide phosphoribosyltransferase (NAMPT) is a promising antitumor target. Novel NAMPT inhibitors with diverse chemotypes are highly desirable for development of antitumor agents. Using high throughput screening system targeting NAMPT on a chemical library of 30000 small-molecules, we found a non-fluorescent compound F671-0003 and a fluorescent compound M049-0244 with excellent in vitro activity (IC50: 85 nM and 170 nM respectively) and anti-proliferative activity against HepG2 cells. These two compounds significantly depleted cellular NAD levels. Exogenous NMN rescued their anti-proliferative activity against HepG2 cells. Structure-activity relationship study proposed a binding mode for NAMPT inhibitor F671-0003 and highlighted the importance of hydrogen bonding, hydrophobic and π-π interactions in inhibitor binding. Imaging study provided the evidence that fluorescent compound M049-0244 (3 µM) significantly stained living HepG2 cells. Cellular fluorescence was further verified to be NAMPT dependent by using RNA interference and NAMPT over expression transgenic mice. Our findings provide novel antitumor lead compounds and a "first-in-class" fluorescent probe for imaging NAMPT.

Discovery and characterization of novel small-molecule inhibitors targeting nicotinamide phosphoribosyltransferase.

Nicotinamide phosphoribosyltransferase (NAMPT) is a promising anticancer target. Using high throughput screening system targeting NAMPT, we obtained a potent NAMPT inhibitor MS0 (China Patent ZL201110447488.9) with excellent in vitro activity (IC50 = 9.87 ± 1.15 nM) and anti-proliferative activity against multiple human cancer cell lines including stem-like cancer cells. Structure-activity relationship studies yielded several highly effective analogues. These inhibitors specifically bound NAMPT, rather than downstream NMNAT. We provided the first chemical case using cellular thermal shift assay to explain the difference between in vitro and cellular activity; MS7 showed best in vitro activity (IC50 = 0.93 ± 0.29 nM) but worst cellular activity due to poor target engagement in living cells. Site-directed mutagenesis studies identified important residues for NAMPT catalytic activity and inhibitor binding. The present findings contribute to deep understanding the action mode of NAMPT inhibitors and future development of NAMPT inhibitors as anticancer agents.

Retrospective Analysis of Vancomycin Nephrotoxicity in Elderly Chinese Patients.

This study explored nephrotoxicity in elderly Chinese patients after exposure to vancomycin and other nephrotoxic risk factors. This was a single-center retrospective study. The patient population included those who were ≥60 years of age, had normal baseline serum creatinine values, and received vancomycin for ≥48 h between January 1, 2013 and August 30, 2014. Nephrotoxicity occurred in 29% of 124 patients. A baseline creatinine clearance ≥63.5 ml/min was more common in the nephrotoxic group. Patients with high (≥15 mg/l) rather than low (<15 mg/l) average vancomycin troughs had elevated nephrotoxicity (47.2 vs. 27.3%, p = 0.0001). Of the comorbid conditions evaluated, there were more patients with shock (p = 0.001), hypertension (p = 0.020) and congestive heart failure (p = 0.04) in the nephrotoxic group. Drugs frequently given at the same time with vancomycin, such as angiotensin receptor blockers and furosemide, were also associated with increased nephrotoxic risk. In conclusion, nephrotoxicity was frequently observed in patients with concurrent vancomycin trough concentrations ≥15 µg/ml and hypertension, shock, congestive heart failure. In addition, drugs concurrently used with vancomycin may also increase its nephrotoxicity. Therefore, renal function and vancomycin serum troughs should be closely monitored, especially in patients with other renal injury risk factors.

Extracellular visfatin has nicotinamide phosphoribosyltransferase enzymatic activity and is neuroprotective against ischemic injury.

AIM: Visfatin, a novel adipokine, is predominantly produced by visceral adipose tissue and exists in intracellular and extracellular compartments. The intracellular form of visfatin is proved to be nicotinamide phosphoribosyltransferase (NAMPT) and exhibits neuroprotection through maintaining intracellular NAD(+) pool. However, whether extracellular form of visfatin has NAMPT activity and the effect of extracellular visfatin in cerebral ischemia are unknown. METHODS AND RESULTS: Plasma concentrations of visfatin, NAD(+) , and ATP were increased in mice upon cerebral ischemia. Cultured glia, but not neuron, was able to secrete visfatin. Oxygen-glucose deprivation (OGD) stress increased the secretion of visfatin from glia. Extracellular recombinant mouse wild-type visfatin, but not mouse H247A-mutant enzymatic-dead visfatin, had NAMPT enzymatic function in vitro. Treatment of wild-type visfatin, but not H247A-mutant enzymatic-dead visfatin, significantly attenuated detrimental effect of OGD on the cell viability and apoptosis in both cultured mouse neuron and glia. Treatment of neutralizing antibody, abolished the protective effect of extracellular visfatin on cell viability, but failed to block the antiapoptotic effect of extracellular visfatin. At last, we observed that plasma visfatin concentrations decreased in 6-month-old but not 3-month-old SHR-SP compared with that in age-matched Wistar-Kyoto rats. Inhibition of NAMPT enzymatic function of visfatin (by FK866) accelerated the occurrence of stroke in SHR-SP. CONCLUSIONS: Extracellular visfatin has NAMPT enzymatic activity and maybe be neuroprotective just as intracellular visfatin in cerebral ischemic injury.