[Role of pyroptosis in bilirubin-induced microglial injury]

OBJECTIVE

To study whether pyroptosis is involved in the bilirubin-induced injury of primary cultured rat cortical microglial cells.

METHODS

Primary cultured rat cortical microglial cells were randomly administered with 30 μmol/L bilirubin (bilirubin group), 30 μmol/L bilirubin following 30 μmol/L VX-765 pretreatment (VX-765+bilirubin group), or an equal volume of dimethyl sulfoxide (control group). Modified MTT assay was used to measure the viability of microglial cells. Western blot was used to measure the expression of the pyroptosis-related proteins Caspase-1 and gasdermin D (GSDMD). Lactate dehydrogenase (LDH)-release assay was used to evaluate the cytotoxicity of microglial cells. EtBr/EthD2 with different molecular weights (394 Da/1 293 Da) was used to measure the size of plasma membrane pores. ELISA was used to measure the level of the inflammatory factor interleukin-1β (IL-1β) in culture supernatant.

RESULTS

After bilirubin stimulation, the viability of microglial cells decreased and LDH release increased, both in a time-dependent manner. Compared with the control group, the bilirubin group had a significantly higher positive rate of small-molecule EtBr passing through the cell membrane (P<0.001), while there was no significant difference in the pass rate of large-molecule EthD2 between groups (P>0.05). The expression of activated Caspase-1 significantly increased at 0.5 hour after bilirubin stimulation (P<0.05), and that of activated GSDMD significantly increased at 6 hours after bilirubin stimulation (P<0.05). The release of IL-1β significantly increased at 6 hours after bilirubin stimulation and reached the peak at 24 hours (P<0.001). Compared with the bilirubin group, the VX-765+bilirubin group had a significant increase in cell viability (P<0.05) and significant reductions in the expression of activated GSDMD, the pass rate of EtBr, and the release of LDH and IL-1β (P<0.05).

CONCLUSIONS

Pyroptosis is involved in bilirubin-induced injury of primary cultured microglial cells.

A Prediction Nomogram for Acute Kidney Injury in Very-Low-Birth-Weight Infants: A Retrospective Study

Background and objective: Acute kidney injury (AKI) is recognized as an independent predictor for mortality in very-low-birth-weight (VLBW) infants and is reported to have a high incidence. In this study, we sought to identify the predictors for AKI in VLBW infants and thereby develop a prediction nomogram for the early detection and management of VLBW infants at high risk of developing AKI. Methods: We designed a retrospective study wherein we investigated the baseline hospitalization data of VLBW infants treated at our hospital between January 2012 and October 2018. Independent predictors of AKI in VLBW infants, as identified by multivariate logistic regression, were incorporated into a model. Hosmer-Lemeshow test was used to test the goodness of fit of the model, and a receiver operating characteristic (ROC) curve was plotted to assess the discriminative ability of the model. The model was internally validated using the 10-fold cross-validation method. A nomogram was plotted to predict the risk of AKI in VLBW infants on the basis of the results of multivariate logistic regression analysis. Results: We investigated the data of 604 VLBW infants, of which 144 (23.8%) developed AKI; in 111 (77.1%) of these infants, AKI occurred within 7 days of birth. Multivariate logistic regression analysis identified the following as predictive factors for AKI in VLBW infants: gestational age, red blood cell count within 3 days of birth, serum calcium concentration within 3 days of birth, maternal age of ≥35 years, and pulmonary arterial hypertension or myocardial injury. Furthermore, the nomogram was found to be effective in estimating the risk of AKI in VLBW infants, with an area under the curve (AUC) of 0.794 [95% confidence interval (CI): 0.754-0.834; P < 0.001]. Internal validation done by cross-validation showed that the average AUC was 0.788. Conclusion: The nomogram developed in this study was found to be sensitive and specific for the preoperative prediction of AKI in VLBW infants, as per the Kidney Disease: Improving Global Outcomes (KDIGO) criteria modified for neonates.

[Application of the Evidence-based Practice for Improving Quality method in neonatal intensive care units]

The Evidence-based Practice for Improving Quality (EPIQ) method was proposed by Canadian Neonatal Network for high quality health care. The method is characterized by evidence-based, targeted, collaborative and continuous concept. At present it is applied in neonatal intensive care units (NICUs). This review article focuses on the application of the method in NICUs.

[An analysis of 181 cases with blood stream infection caused by Streptococcus agalactiae in children from 2011 to 2015: a multi-center retrospective study]

OBJECTIVE

To analyze the clinical characteristics of blood stream infection caused by Streptococcus agalactiae in children and the drug-resistance of the isolates.

METHOD

All cases with Streptococcus agalactiae growth in blood or cerebrospinal fluid cultures from January 1, 2011 to December 31, 2015 were enrolled by checking the laboratory information system (LIS) from 7 Class 3 Grade A hospitals (4 in Zhejiang, 2 in Shanghai and 1 in Chongqing). Clinical data were collected for analysis. χ(2) test, t test and non parametric test were used in the study.

RESULT

One hundred and eighty-one pediatric cases of blood stream infection caused by Streptococcus agalactiae were included in current study. Eighty-six cases (47.5%) were male, and with age range from one day to 9 years (media 13 days). Thirty cases (16.6%) were premature infants and 127 cases (70.2%) were born via vaginal delivery. Seventy-one cases (39.2%) had early onset (<7 d) infections, and 106 cases (58.6%) had late onset (7-89 d) infections. Seventy-eight cases (43.1%) were complicated with purulent meningitis. Incidences of vaginal delivery(81.7%(58/71) vs. 62.3%(66/106)), shortness of breath moaning (43.7%(31/71) vs. 15.1%(16/106)) and preterm premature rupture of membranes (25.4%(18/71) vs. 3.8%(4/106)) were higher in the early onset infection group compared with the late onset group(P all<0.05). However, the number of cases who had fever(25.4%(18/71)vs.85.8%(91/106)) and complicated with purulent meningitis (29.6%(21/71) vs. 53.8%(57/106)) in early onset infections group was less than that in the late onset group(P both<0.05). The blood cultures of most patients (87.8%) were performed before the use of antibiotics. Drug-resistant tests showed that the sensitive rates to penicillin G, ceftriaxone and cefotaxime were 98.9%, 99.0% and 99.0% respectively. All strains were sensitive to vancomucine. The rates of resistance to clindamycin and erythromycin were 68.0% and 34.0%, respectively. Only 39 cases (22.0%) were treated with single antibiotics of either penicillins or cephalosporins, 80 cases (45.2%) were treated with antibiotics containing β lactamase inhibitor, 61 cases (34.5%) were treated with either meropenem or cefoperazone-sulbactam. One hundred and fifty-four cases were cured, while 19 died (including 13 complicated with purulent meningitis) and 8 lost to follow up after giving up of treatment.

CONCLUSION

The incidence and mortality of blood stream infection caused by Streptococcus agalactiae complicated with purulent meningitis are high in children. Penicillin is the first choice in treatment. Antibiotics should be selected accorrding to the drug-resistance test.

[Effects of antibiotic stewardship on neonatal bloodstream infections]

OBJECTIVE

To investigate the effects of antibiotic stewardship on the pathogen and clinical outcome of neonatal bloodstream infections (BSIs).

METHODS

A retrospective study was performed on neonates with BSIs who were admitted to the neonatal ward in the years of 2010 (pre-stewardship) and 2013 (post-stewardship) for pathogens, antibiotic resistance, antibiotic use, and clinical outcomes.

RESULTS

The admission rate of BSIs (6.47% vs 2.78%) and the incidence of nosocomial BSIs (0.70% vs 0.30%) in 2013 were significantly higher than in 2010 (P<0.01). However, there were no signicant differences in the clinical outcomes between the years of 2010 and 2013 (P>0.05). The four most common pathogens isolated from blood cultures, Staphylococcus haemolyticus, Staphylococcus epidermidis, Klebsiella pneumoniae ssp pneumoniae and E.coli, were similar between the two years. There were no significant differences in the detection rates of extended spectrum β-lactamase-positve Klebsiella pneumoniae ssp pneumoniae or E.coli between the two years. The detection rates of methicillin-resistant Staphylococcus/β-lactamase-positive Staphylococcus haemolyticus and Staphylococcus epidermidis were similar between the two years (P>0.05).

CONCLUSIONS

Since the implementation of antibiotic stewardship, there has been no marked variation in the common pathogens and their antibacterial resistance in neonatal BSIs. The antibiotic stewardship could promote the recovery of patients with BSIs.

[Efficacy of pulmonary surfactant therapy in neonates with meconium aspiration syndrome: a meta-analysis]

OBJECTIVE

The efficacy of pulmonary surfactant (PS) replacement therapy for meconium aspiration syndrome (MAS) remains controversial. This study aimed to evaluate the efficacy of PS therapy in neonates with MAS by a meta-analysis.

METHODS

Randomized controlled trials (RCTs) on the treatment of MAS with PS were searched electronically in medical debases including PubMed, Science Citation Index, The Cochrane Central Register of Controlled Trials, Ovid, EBSCOhost, BIOSIS previews, Chinese BioMedical Literature Database, Wanfang Database and VIP Chinese Sci-Tech Periodical Database. The Cochrane Handbook 5.0.2 was employed to evaluate methodological quality. RevMan 5.0.25 software was used for the meta-analysis.

RESULTS

Eight RCTs including 512 MAS neonates (257 cases in the PS treatment group and 255 cases in the control group) were enrolled in this meta-analysis. The meta-analysis showed that PS treatment reduced oxygenation index (MD=-2.59; 95%CI: -4.33, -0.86; P=0.003), increased arterial oxygen/alveolar oxygen ratio (MD=0.05; 95%CI: 0.05, 0.06; P<0.00001), shortened hospitalization days (MD=-4.94; 95%CI: -7.44, -2.44; P=0.0001) and decreased mortality rate (OR=0.47; 95%CI: 0.24, 0.93; P=0.03) significantly. There were no statistical differences in the durations of mechanical ventilation and oxygen therapy, and the incidences of air leak, pulmonary hemorrhage and intracranial hemorrhage between the PS treatment and control groups.

CONCLUSIONS

Currently published evidence from RCTs suggests that PS replacement therapy is effective for MAS, however because of the limited quantity and quality of trials enrolled in the study, further evidence from RCTs is needed to prove the efficacy.

3,9-Bis(dicyanomethylene)-2,4,8,10-tetrathiaspiro[5.5]undecane

The title compound, 2,2'-(2,4,8,10-tetrathiaspiro[5.5]undecane-3,9-diylidene)bis(propanedinitrile), C(13)H(8)N(4)S(4), has been designed and synthesized for use as a potential new organic molecular electronic material. The spiro-annulated structure has twofold symmetry and is formed by two equal push-pull ethylene units, with the cycloalkylthio groups as electron donors and the cyano groups as electron acceptors. The intermolecular S.N non-bonded separation within a layer in the lattice is 3.296 (6) A, indicating a strong intermolecular interaction between the cyano groups and the S atoms, while the S atoms in two neighbouring molecules have a shortest S.S contact of 3.449 (3) A. In addition, attractive C-H.N and C-H.S interactions bridge adjacent molecules either within a layer or between layers. In short, these four types of intermolecular interactions combine to form an extended three-dimensional network in the lattice, resulting in a highly ordered array of molecular packing.

Relationship between autoregressive model coefficients of EMG and its potentials of jaw closing muscles at rest position and clenching

At rest position and varied clenching levels at intercuspal position, autoregressive (AR) models of myoelectrical activities of both masseter and anterior temporal muscles of 11 healthy subjects with intact natural dentitions were established. The relationship between the AR model coefficients of surface EMGs and their potentials was analyzed by multiple linear regression. It was found that the fourth order coefficient of AR had the greatest effect on the EMG potential levels and their relationship was positive in all recorded muscles. The results indicate the AR coefficients may become a characteristic parameter to describe myoelectrical activity of jaw closing muscles.

Pancreatic phospholipase A2 in proximal tubules of rat kidney in experimental acute pancreatitis and after intravenous injection of the enzyme

Kinetics and distribution of i.v. human pancreatic phospholipase A2 (h-PLA2) were determined in intact and nephrectomized rats, and tissue localization of rat pancreatic PLA2 (r-PLA2) was studied by immunohistochemistry in experimental acute pancreatitis. The concentration of h-PLA2 and the catalytic activity of phospholipase A2 in plasma decreased exponentially in intact and nephrectomized animals after the injection. The initial 15-min half-life was considerably longer in nephrectomized animals, and higher h-PLA2 concentrations and PLA2 catalytic activities were found in plasma. h-PLA2 was localized in endocytotic vesicles and apical cytoplasmic vacuoles in proximal tubule cells of the kidney. The intensity of the immunoreaction decreased considerably between 15 and 50 min in these cells. No signs of tubular damage were seen by light microscopy. Neither immunoreactive h-PLA2 nor PLA2 catalytic activity was found in urine. r-PLA2 was observed in proximal tubule cells 15 min after an injection of sodium taurocholate (necrotizing pancreatitis group) or saline (edematous pancreatitis group) into the pancreatic duct. Signs of tubular damage were present in necrotizing pancreatitis, but tubular morphology was normal in the animals with edematous pancreatitis. We conclude that the proximal tubule cells of the kidney participate in the metabolism of circulating pancreatic PLA2, and considerably higher PLA2 levels persist in plasma in nephrectomized animals. Endogenous pancreatic PLA2 is detected in kidneys in acute pancreatitis.

Correlations between an autoregressive model coefficient of the electromyogram of human jaw-closing muscles and maximum clenching time at the intercuspal position

During maximum clenching in the intercuspal position, surface electromyograms of both masseters and both anterior temporales in seven healthy subjects with intact natural dentitions were sampled to generate a four-order, autoregressive model of the myoelectrical signal. The correlation coefficients and the linear regression between the model coefficients and the clenching time were calculated. The first-order autoregressive coefficient had the greatest negative correlation on average. In this model the first-order coefficient relates to muscular fatigue and the slope of the regressive equation relates to the length of time the isometric contraction can be maintained.