Activated sludge is a complicated microbial ecosystem that has diversity. Based on the diversity,microorganisms are selected by acclimation condition:the survival of the fittest,otherwise eliminate through selection or contest. Moreover,microorganisms in activated sludge acclimatize themselves to acclimation conditions. In the process the ecosystem distributes and adjusts microbial niche over again. The theory of "selection and acclimatization" may be used to explain the mechanism of activated sludge acclimation. So then,original sludge,wastewater quality and treating process are major influencing factors for activated sludge acclimation.

To explore the underlying mechanism(s) of pulmonary arterial hypertension in endotoxic shock, the roles of N-acetylcysteine (NAC), nitric oxide (NO) and carbon monoxide (CO) were investigated. Pulmonary arterial rings (3-mm width) were prepared from 24 rabbits. Lipopolysaccharide (LPS), after 7-hour incubation, decreased the endothelium-dependent relaxation response of the arterial ring (pre-contracted with phenylephrine) to acetylcholine (1 mumol/L), but did not affect the endothelium-independent relaxation response to sodium nitroprusside. The LPS effects were reduced by a concomitant incubation with the free radical scavenger (NAC), NO donor (L-arginine), and CO donor (hemin), respectively. On the other hand, the LPS effects were enhanced by applying heme oxygenase-1 (HO-1) inhibitor (zinc protoporphyrin) to block CO production. The response to acetylcholine changed from relaxation to contraction, however, the contractile response to phenylephrine increased significantly after pre-incubation with nitric oxide synthase (NOS) inhibitor (L-NAME) to block NO production, confirming the importance of CO and NO. These results show that LPS impairs endothelium-dependent relaxation of the pulmonary artery, which can be greatly reduced by the antioxidant, or by supplying with NO and CO. Thus, multiple factors are involved in this model of endotoxin-induced pulmonary hypertension.
Acetylcysteine ; metabolism ; Animals ; Carbon Monoxide ; metabolism ; Hypertension, Pulmonary ; etiology ; physiopathology ; Lipopolysaccharides ; toxicity ; Male ; Nitric Oxide ; metabolism ; Pulmonary Artery ; drug effects ; physiopathology ; Rabbits ; Shock, Septic ; complications

OBJECTIVETo investigate the influence of heat shock factor1 (HSF1) on gene expression of inflammatory mediators in RAW264.7 murine macrophage cells induced by burn serum.

METHODSSera were separated from blood of normal rats and rats with severe burns, and the recombinant vector pcDNA3. 1/HSF1 was constructed. RAW264.7 macrophages were divided into non-transfection group, vacant vector group (with burn and normal sera stimulation, respectively after vacant vector transfection) and recombinant vector group (with burn and normal sera stimulation, respectively after recombinant vector transfection). Some recombinant vector transfected macrophages without serum stimulation were prepared for the determination of HSF 1 expression with Western blotting. The mRNA expressions of TNF-alpha, HMGB 1 and IL-10 were determined with RT-PCR.

RESULTSThe cell line attained after recombinant vector transfection was comparatively stable,with partial activation of HSF 1. Burn sera markedly upregulated TNF-alpha, HMGB1 mRNA expression (0.910 +/- 0.100, 0.860 +/- 0.020, respectively), but downregulated IL-10 expression (0.430 +/- 0.010, respectively) in normal macrophages, while these genes maintained in a very low level in normal macrophages with normal serum stimulation . macrophages with recombinant vector transfection and burn serum stimulation could obviously inhibit the expression of TNF-alpha and HMGB 1, but enhance the IL-10 gene expression (0.130 +/- 0.100, 0.450 +/- 0.020 , 0.450 +/- 0.020, respectively )when compared with that with vacant vector transfection and burn serum stimulation (0.800 +/- 0.050, 0.880 +/- 0.030, 0.420 +/- 0.010, respectively).

CONCLUSIONHSF1 can inhibit the expression of some pro-inflammatory mediators in macrophages after a severe burns, indicating that appropriate upregulation of anti-inflammatory mediators might exert protective effects on the organism.

Animals ; Burns ; metabolism ; Cell Line ; DNA-Binding Proteins ; genetics ; Female ; Gene Expression ; HMGB1 Protein ; metabolism ; Heat Shock Transcription Factors ; Heat-Shock Response ; genetics ; Inflammation Mediators ; metabolism ; Interleukin-10 ; metabolism ; Macrophages ; metabolism ; Male ; Rats ; Rats, Sprague-Dawley ; Serum ; Transcription Factors ; genetics ; Transfection ; Tumor Necrosis Factor-alpha ; metabolism

OBJECTIVETo promote stem cells differentiation into neurons and enhance neuromotor function after brain injury through brain-derived neurotrophic factor (BDNF) induction.

METHODSRecombinant adenovirus vector was applied to the transfection of BDNF into human-derived umbilical cord mesenchymal stem cells (UCMSCs). Enzyme linked immunosorbent assay (ELISA) was used to determine the secretion phase of BDNF. The brain injury model of athymic mice induced by hydraulic pressure percussion was established for transplantation of stem cells into the edge of injury site. Nerve function scores were obtained, and the expression level of transfected and non-transfected BDNF, proportion of neuron specific enolase (NSE) and glial fibrillary acidic protein (GFAP), and the number of apoptosis cells were compared respectively.

RESULTSThe BDNF expression achieved its stabilization at a high level 72 hours after gene transfection. The mouse obtained a better score of nerve function, and the proportion of the NSE-positive cells increased significantly (P<0.05), but GFAP-positive cells decreased in BDNF-UCMSCs group compared with the other two groups (P<0.05). At the site of high expression of BDNF, the number of apoptosis cells decreased markedly.

CONCLUSIONBDNF gene can promote the differentiation of the stem cells into neurons rather than glial cells, and enhance neuromotor function after brain injury.

Adenoviridae ; genetics ; Animals ; Apoptosis ; Brain Injuries ; physiopathology ; therapy ; Brain-Derived Neurotrophic Factor ; analysis ; genetics ; Cell Differentiation ; Glial Fibrillary Acidic Protein ; Humans ; Mesenchymal Stem Cell Transplantation ; Mesenchymal Stromal Cells ; cytology ; Mice ; Nerve Tissue Proteins ; analysis ; Neurons ; cytology ; Phosphopyruvate Hydratase ; analysis ; Transfection

OBJECTIVE: To investigate the current status of antibiotic use for very and extremely low birth weight (VLBW/ELBW) infants in neonatal intensive care units (NICUs) of Hunan Province. METHODS: The use of antibiotics was investigated in multiple level 3 NICUs of Hunan Province for VLBW and ELBW infants born between January, 2017 and December, 2017. RESULTS: The clinical data of 1 442 VLBW/ELBW infants were collected from 24 NICUs in 2017. The median antibiotic use duration was 17 days (range: 0-86 days), accounting for 53.0% of the total length of hospital stay. The highest duration of antibiotic use was up to 91.4% of the total length of hospital stay, with the lowest at 14.6%. In 16 out of 24 NICUs, the antibiotic use duration was accounted for more than 50.0% of the hospitalization days. There were 113 cases with positive bacterial culture grown in blood or cerebrospinal fluid, making the positive rate of overall bacterial culture as 7.84%. The positive rate of bacterial culture in different NICUs was significantly different from 0% to 14.9%. The common isolated bacterial pathogens Klebsiella pneumoniae was 29 cases (25.7%); Escherichia coli 12 cases (10.6%); Staphylococcus aureus 3 cases (2.7%). The most commonly used antibiotics were third-generation of cephalosporins, accounting for 41.00% of the total antibiotics, followed by penicillins, accounting for 32.10%, and followed by carbapenems, accounting for 13.15%. The proportion of antibiotic use time was negatively correlated with birth weight Z-score and the change in weight Z-score between birth and hospital discharge (r=-0.095, -0.151 respectively, P<0.01), positively correlated with death/withdrawal of care (r=0.196, P<0.01). CONCLUSIONS Antibiotics used for VLBW/ELBW infants in NICUs of Hunan Province are obviously prolonged in many NICUs. The proportion of routine use of third-generation of cephalosporins and carbapenems antibiotics is high among the NICUs.
Anti-Bacterial Agents ; Birth Weight ; Humans ; Infant ; Infant, Extremely Low Birth Weight ; Infant, Newborn ; Intensive Care Units, Neonatal ; Surveys and Questionnaires