Zika virus targets human trophoblast stem cells and prevents syncytialization in placental trophoblast organoids.

Zika virus (ZIKV) infection during pregnancy threatens pregnancy and fetal health. However, the infectivity and pathological effects of ZIKV on placental trophoblast progenitor cells in early human embryos remain largely unknown. Here, using human trophoblast stem cells (hTSCs), we demonstrated that hTSCs were permissive to ZIKV infection, and resistance to ZIKV increased with hTSC differentiation. Combining gene knockout and transcriptome analysis, we demonstrated that the intrinsic expression of AXL and TIM-1, and the absence of potent interferon (IFN)-stimulated genes (ISGs) and IFNs contributed to the high sensitivity of hTSCs to ZIKV. Furthermore, using our newly developed hTSC-derived trophoblast organoid (hTSC-organoid), we demonstrated that ZIKV infection disrupted the structure of mature hTSC-organoids and inhibited syncytialization. Single-cell RNA sequencing (scRNA-seq) further demonstrated that ZIKV infection of hTSC-organoids disrupted the stemness of hTSCs and the proliferation of cytotrophoblast cells (CTBs) and probably led to a preeclampsia (PE) phenotype. Overall, our results clearly demonstrate that hTSCs represent the major target cells of ZIKV, and a reduced syncytialization may result from ZIKV infection of early developing placenta. These findings deepen our understanding of the characteristics and consequences of ZIKV infection of hTSCs in early human embryos.

Floating Mat Formation Makes Zizania latifolia More Competitive under the Conditions of Continuous Significant Water Level Rise.

Water level rise is considered an environmental filter for the growth and reproduction of aquatic plants in lakes. Some emergent macrophytes can form floating mats, enabling them to escape from the negative effects of deep water. However, an understanding of which species can be uprooted and form floating mats easily and what factors affect these tendencies remains greatly elusive. We conducted an experiment to determine whether the monodominance of Zizania latifolia in the emergent vegetation community in Lake Erhai was related to its floating mat formation ability and to try to find the reasons for its floating mat formation ability during the continuous increase in water level over the past few decades. Our results showed that both the frequency and biomass proportion of Z. latifolia were greater among the plants on the floating mats. Furthermore, Z. latifolia was more likely to be uprooted than the other three previously dominant emergent species due to its smaller angle between the plant and the horizontal plane, rather than the root:shoot or volume:mass ratios. The dominance of Z. latifolia in the emergent community in Lake Erhai is due to its easier ability to become uprooted, allowing it to outperform other emergent species and become the single dominant emergent species under the environmental filter of deep water. The ability to uproot and form floating mats may be a competitive survival strategy for emergent species under the conditions of continuous significant water level rise.

Invasive Ageratina adenophora can maintain its ecological advantages over time through releasing its autotoxicity by accumulating a bacterium Bacillus cereus.

Plant invasive success is attributed to invaders' ecological advantages over their native neighbors. However, increasing evidence suggests that these advantages are expected to attenuate over time because of natural enemy accumulation, ecological evolution of native species and autotoxicity. We determined how an invasive Ageratina adenophora could remain its competitive advantages over time by avoiding its autotoxicity. Our results highlighted that the autotoxicity of A. adenophora in its invaded soil was reduced by some microbes. Moreover, an autotoxic allelochemical, 2-coumaric acid glucoside, detected in the invaded soil, demonstrated distinctly autotoxic effects on its seed germination and seedling growth. However, the autotoxic effects were greatly alleviated by a bacterium Bacillus cereus, accumulated by A. adenophora. Furthermore, the allelochemical could be almost completely degraded by B. cereus within 96 h. Accordingly, we speculate that A. adenophora could aggregate B. cereus to release its autotoxicity maintaining its competitive advantages over time.

The latitudinal and longitudinal allelopathic patterns of an invasive alligator weed (Alternanthera philoxeroides) in China.

Allelopathy has been considered a good explanation for the successful invasion of some invasive plants. However, the real latitudinal and longitudinal allelopathic effects on native species have rarely been documented since many exotics have spread widely. We conducted a Petri dish experiment to determine the latitudinal and longitudinal allelopathic patterns of an invasive alligator weed (Alternanthera philoxeroides) on a common crop (Lactuca sativa) in China, and find what determines the allelopathic intensity. The results showed that the allelopathic effects of A. philoxeroides increased with the latitude while decreased with the longitude. This indicated that A. philoxeroides used its allelopathy to gain competitive advantages more in its recent invaded communities than that in its early invaded ones as A. philoxeroides is expanding from southeast China to northwest China. Furthermore, we found that the allelopathic intensity of A. philoxeroide was negatively correlated to the leaf contents of soluble carbohydrate (SC), carbon (C) and nitrogen (N), but that was positively correlated to the leaf contents of soluble protein (SP), free amino acids (FAA), plant polyphenol (PP), phosphorus (P) and potassium (K). These results suggested that the allelopathic intensity of A. philoxeroide was more determined by the limited P and K nutrients as well as the intermediate allelochemicals (SP, FAA, PP) rather than the unlimited C, N and SC. Thus, we can speculate that the negative or positive effects of plant aqueous extracts are a function of not only the extract concentrations but also the trade-offs between inhibition and promotion of all components in the extracts. Then we could reduce the allelopathic effects of A. philoxeroide by controlling the component contents in the plant tissues, by fertilization or other managements, especially in the plant recent invaded communities.

[Analysis on the Characteristics of Oxidation Potential and Influence Sources of PM2.5 in Baoding City in Winter].

In order to explore the characteristics of PM2.5 oxidation potential and its impact sources in the suburbs of Baoding City in the winter of 2018, the dithiothreitol (DTT) method was used to determine the reactive oxygen species in PM2.5. Pearson correlation was used to analyze the relationship between the chemical components in PM2.5 and the oxidation potential. PMF was used to analyze the pollution source of DTTv. Firstly, the results showed that the average value of ρ(PM2.5) in Baoding in winter was (140.96±70.67) µg·m-3 higher than the concentration of PM2.5 in Beijing during the same period. Secondly, both the DTTv and DTTm values of the oxidation potential were higher during the day than those at night[DTTv was (2.37±0.76) nmol·(min·m3)-1 during the day and (2.14±1.17) nmol·(min·m3)-1 at night; DTTm was (0.96±0.60) pmol·(min·µg)-1 during the day and (0.76±0.41) pmol·(min·µg)-1 at night]. This showed that the atmospheric environment during the day was more conducive to the generation and survival of active oxygen. In addition, through the analysis of the correlation between DTTv and carbohydrates, inorganic salt ions, OC, EC, and water-soluble metals, it was found that metal Fe, oxalate, and NH4+ had a high correlation with DTTv both day and night (during the day:r=0.790, P<0.01, at night:r=0.960, P<0.01; during the day:r=0.609, P<0.01, at night:r=0.577, P<0.01; during the day:r=0.627, P<0.01, at night:r=0.586, P<0.01), and OC, levoglucan, mannan, and galactan were only highly correlated with DTTv in the daytime (r=0.675, P<0.01; r=0.701, P<0.01; r=0.662, P<0.01; r=0.671, P<0.01). Finally, according to the PMF source analysis, there were five main pollution sources that affected DTTv:secondary sources (29.9%), biomass combustion (29.2%), dust (11.2%), mineral dust and industrial sources (8.6%), and traffic sources (21.1%). The influence of secondary sources and biomass combustion on DTTv was dominant.

High-light inhibition of two submerged macrophytes in a shallow water experiment.

The negative effects, caused by high light, on algae, terrestrial and marine aquatic plants are well documented; those negative effects on freshwater submerged plants are, however, not well known. We determined the negative effects of two common submerged species, Myriophyllum spicatum and Vallisneria natans, on their growth and reproduction in a shallow water experiment along an irradiance gradient. Our results highlighted that the plant mass, relative growth rate and shoot height of V. natans and M. spicatum, and root mass and root length:root mass of M. spicatum and leaf mass and shoot height:shoot mass of V. natans were significantly negatively affected in shallow water with high-light regime (>50 % of full light). While the ramet number of the two species was stimulated by from 20.0 to 36.4 %, and root length, root:shoot, chlorophyll (a:b), chlorophyll (a + b), leaf carbon, nitrogen and phosphorus contents of the two studied macrophytes were not significantly impacted by light. Our results indicated that the high-light inhibition of plant growth was greater on the shoots than on the roots of the plants, although these effects were significantly different between the two studied submerged species and among the measured traits. Accordingly, we should avoid negative effects caused by high light to improve the performance of submerged species when we conduct submerged aquatic vegetation restoration programmes in eutrophic lakes.

Exploring the interaction between Cry1Ac protein and Zn2+, Cd2+ metal ions by fluorescence quenching and molecular docking approaches.

Bacillus Thuringiensis (Bt) protein has a strong ability to complex with metal ions, which may increase the transport of metal ions in the soil multi-media system. In this study, the interactions between Cry1Ac protein and metal ions (Zn2+ and Cd2+) were investigated through spectroscopies and molecular docking methods. The spectra results showed that both Zn2+ and Cd2+ quenched the fluorescence intensity of Cry1Ac protein through the static quenching. The binding constants with 4-5 orders of magnitude also indicated the interactions between the ions and the Cry1Ac protein. The thermodynamic analysis showed that hydrogen bonds and van der Waals forces were predominant during the processes. In terms of the Förster non-radiation energy transfer theory, the binding distances between metal ions and Cry1Ac protein were approximately 0.21-0.24 nm, indicating the existence of a non-radiative energy transfer between them. Furthermore, molecular docking revealed that the metal ions participated in ligand binding with the Cry1Ac at the locations Asp569, Thr560, Asn564 and Gln566. The present work provided reasonable models helping us further understand the transport effect of heavy metals in the presence of Cry1Ac. The results could provide mechanistic insights into the nature of metal ions-Cry1Ac interactions and offer important information on the toxicity risk of metal ions-Cry1Ac binding interactions.

Predictive nomogram for leprosy using genetic and epidemiological risk factors in Southwestern China: Case-control and prospective analyses.

BACKGROUND: There is a high incidence of leprosy among house-contacts compared with the general population. We aimed to establish a predictive model using these genetic factors along with epidemiological factors to predict leprosy risk of leprosy household contacts (HHCs). METHODS: Weighted genetic risk score (wGRS) encompassing genome wide association studies (GWAS) variants and five non-genetic factors were examined in a case-control design associated with leprosy risk including 589 cases and 647 controls from leprosy HHCs. We constructed a risk prediction nomogram and evaluated its performance by concordance index (C-index) and calibration curve. The results were validated using bootstrap resampling with 1000 resamples and a prospective design including 1100 HHCs of leprosy patients. FINDING: The C-index for the risk model was 0·792 (95% confidence interval [CI] 0·768-0·817), and was confirmed to be 0·780 through bootstrapping validation. The calibration curve for the probability of leprosy showed good agreement between the prediction of the nomogram and actual observation. HHCs were then divided into the low-risk group (nomogram score ≤ 81) and the high-risk group (nomogram score > 81). In prospective analysis, 12 of 1100 participants had leprosy during 63 months' follow-up. We generated the nomogram for leprosy in the validation cohort (C-index 0·773 [95%CI 0·658-0·888], sensitivity75·0%, specificity 66·8%). Interpretation The nomogram achieved an effective prediction of leprosy in HHCs. Using the model, the risk of an individual contact developing leprosy can be determined, which can lead to a rational preventive choice for tracing higher-risk leprosy contacts. FUNDING: The ministry of health of China, ministry of science and technology of China, Chinese academy of medical sciences, Jiangsu provincial department of science and technology, Nanjing municipal science and technology bureau.

Sex-Specific Differences in the Physiological and Biochemical Performance of Arbuscular Mycorrhizal Fungi-Inoculated Mulberry Clones Under Salinity Stress.

Arbuscular mycorrhizal fungi (AMF) are often considered bioameliorators. AMF can promote plant growth under various stressful conditions; however, differences between male and female clones in mycorrhizal strategies that protect plants from the detrimental effects of salinity are not well studied. In this study, we aimed to examine the interactive effects of salinity and AMF on the growth, photosynthetic traits, nutrient uptake, and biochemical responses of Morus alba males and females. In a factorial setup, male and female M. alba clones were subjected to three salinity regimes (0, 50, and 200 mM NaCl) and planted in soil with or without Funneliformis mosseae inoculation. The results showed that NaCl alone conferred negative effects on the growth, salinity tolerance, photosynthetic performance, and shoot and root ionic ratios (K+/Na+, Ca2+/Na+, and Mg2+/Na+) in both sexes; in contrast, mycorrhizal inoculation mitigated the detrimental effects of salinity. Furthermore, the mycorrhizal effects were closely correlated with Mn2+, proline, and N concentrations. Females benefited more from AMF inoculation as shown by the enhancements in their biomass accumulation, and N, proline, K+, Mg2+, Fe2+, Zn2+, and Mn2+ concentrations than males with mycorrhizal inoculation under saline conditions. In comparison, male plants inoculated with AMF showed improvements in biomass allocated to the roots, P, and peroxidase concentrations under saline conditions. These sex-specific differences suggest that male and female mulberry clones adopted different mycorrhizal strategies when growing under saline conditions. Overall, our results provide insight into the sex-specific difference in the performance of AMF-associated mulberry clones, suggesting that female mulberry could be more suitable for vegetation remediation than the male one, due to its higher salinity tolerance.

Negative effects of a piscicide, rotenone, on the growth and metabolism of three submerged macophytes.

A piscicide, rotenone (RT), is frequently used for clear and management of aquatic systems such as fish pond, and even for illegal fishing throughout the world. The effects of RT on submerged macrophytes remain elusive although the effects of RT on many kinds of animals are well documented. We wanted to determine the effects of RT on the growth and metabolism of three submerged plants (Vallisneria natans, Myriophyllum spicatum, Potamogeton maackianus) and try to find the reasons of these effects. The results showed that the shoot height, shoot dry weight, root dry weight, root:shoot ratios, contents of soluble protein and soluble carbohydrate of the three tested submerged plants were significantly negatively affected by RT and the effects were different among the studied species. Furthermore, pH rised a little and light transmission was greatly reduced in the water with RT treatment. We think that the negative effects of RT on the growth and metabolism of submerged species is partially attributing to the lower light caused by RT application. Accordingly, we highlight that submerged species may be greatly suppressed by RT, and we should apply RT in water ecosystems with great caution.

The factors affecting a native obligate parasite, Cuscuta australis, in selecting an exotic weed, Humulus scandens, as its host.

In weed management, using native parasites to control exotic weeds is considered a better alternative than classical biological control. But the risk must be assessed because of the potential damage caused by these agents. We conducted this project to investigate the mechanism driving the choice of a native obligate parasite, Cuscuta australis, between the exotic, Humulus scandens, and native plants as its host through field and pot experiments. The results showed that C. australis preferred the exotic weed over native (naturalized) hosts and caused a notable reduction in the biomass of H. scandens in the field. In contrast, the results of the pot experimentindicated that C. australis preferred a mix of native (naturalized) hosts over the exotic weed. Both texperiments indicated that the parasitic preference of C. australis was induced more by light irradiance than plant water, carbon (C), nitrogen (N) and phosphorus (P) contents, indicating that the native parasite can only be used to control H. scandens when the exotic weed forms mono-cultures or dominates the community. Accordingly, induction and release of C. australis to control H. scandens should be conducted with great caution.

[Effect of Rutin on Liver Function and Morphology in Type 1 Diabetes Mice Induced by Streptozotocin].

OBJECTIVE: To investigate the effect of Rutin on the function and morphology of liver in type 1 diabetes mice induced by streptozotocin (STZ). METHODS: Type 1 diabetic mice model was established with the treatment of STZ by a 5 d intraperitoneal administration to male Kunming mice. Normal group had 12 mice without treatment of STZ,the mice with DM after STZ treated were randomly divided into DM group,low-dose (50 mg/kg) Rutin group and high-dose (100 mg/kg) Rutin group,each group had 12 mice. The mice in normal and DM group were given sodium carboxymethyl cellulose (10 mg/kg). Each mice was given above drugs by intragastric administration for 8 weeks. Postprandial random blood glucose was measured at 4 weeks and 8 weeks and the levels of alanine aminotransferase (ALT),aspartate aminotransferase (AST),lactate dehydrogenase (LDH),total protein (TP) and albumin (ALB) in serum were detected by automatic biochemical analyzer after 8 weeks. The morphology of liver was observed by HE and Masson staining. The ultrastructure of liver tissue was observed by electron microscope. RESULTS: After a continuous small-dose injection of STZ,the success rate of diabetes model mice were up to 98%. The blood glucose of the model group was significantly increased (P<0.01),and the levels of ALT,AST and LDH in serum were significantly higher,and TP and ALB were lower than those in normal group (P<0.05,P<0.01). Compared to the DM group,the levels of blood glucose were lower (P<0.05) at 4 weeks and 8 weeks,the contents of ALT,AST and LDH were significantly decreased,and TP and ALB were improved in both Rutin dose group. High-dose group performed more obvious (P<0.05,P<0.01). Morphological observation showed the tissue morphology of Rutin treatment group were improved obviously,and the effect was more significant in high-dose Rutin group. CONCLUSION: Rutin may improve the liver function and reduce the damage of liver tissue in STZ-induced type 1 diabetic mice.

Prognostic Value of Model for End-Stage Liver Disease Incorporating with Serum Sodium Score for Development of Acute Kidney Injury after Liver Transplantation.

BACKGROUND: Contribution of model for end-stage liver disease incorporating with serum sodium (MELD-Na) score in predicting acute kidney injury (AKI) after orthotopic liver transplantation (OLT) is yet to be identified. This study assessed the prognostic value of MELD-Na score for the development of AKI following OLT. METHODS: Preoperative and surgery-related variables of 321 adult end-stage liver disease patients who underwent OLT in Fuzhou General Hospital were collected. Postoperative AKI was defined and staged in accordance with the clinical practice guidelines developed by Kidney Disease: Improving Global Outcomes. Univariate and multivariate analysis was performed to determine the risk factors for AKI following OLT. The discriminating power of MELD/MELD-Na score on AKI outcome was evaluated by receiver operating characteristic (ROC) curve. Spearman's correlation analysis was used for identifying the correlated relationship between MELD/MELD-Na score and the severity levels of AKI. RESULTS: The prevalence of AKI following OLT was in 206 out of 321 patients (64.2%). Three risk factors for AKI post-OLT were presented, preoperative calculated MELD score (odds ratio [OR] = 1.048, P = 0.021), intraoperative volume of red cell suspension transfusion (OR = 1.001, P = 0.002), and preoperative liver cirrhosis (OR = 2.015, P = 0.012). Two areas under ROC curve (AUCs) of MELD/MELD-Na score predicting AKI were 0.688 and 0.672, respectively; the difference between two AUCs was not significant (Z = 1.952, P = 0.051). The Spearman's correlation coefficients between MELD/MELD-Na score and the severity levels of AKI were 0.406 and 0.385 (P = 0.001, 0.001), respectively. CONCLUSIONS: We demonstrated that preoperative MELD score, intraoperative volume of red cell suspension transfusion and preoperative liver cirrhosis were risk factors for AKI following OLT. Furthermore, we preliminarily validated that MELD score seemed to have a stronger power discriminating AKI post-OLT than that of novel MELD-Na score.

Effects of Propofol on Respiratory Drive and Patient-ventilator Synchrony during Pressure Support Ventilation in Postoperative Patients: A Prospective Study.

BACKGROUND: Propofol is increasingly used during partial support mechanical ventilation such as pressure support ventilation (PSV) in postoperative patients. However, breathing pattern, respiratory drive, and patient-ventilator synchrony are affected by the sedative used and the sedation depth. The present study aimed to evaluate the physiologic effects of varying depths of propofol sedation on respiratory drive and patient-ventilator synchrony during PSV in postoperative patients. METHODS: Eight postoperative patients receiving PSV for <24 h were enrolled. Propofol was administered to achieve and maintain a Ramsay score of 4, and the inspiratory pressure support was titrated to obtain a tidal volume (VT) of 6-8 ml/kg. Then, the propofol dose was reduced to achieve and maintain a Ramsay score of 3 and then 2. At each Ramsay level, the patient underwent 30-min trials of PSV. We measured the electrical activity of the diaphragm, flow, airway pressure, neuro-ventilatory efficiency (NVE), and patient-ventilator synchrony. RESULTS: Increasing the depth of sedation reduced the peak and mean electrical activity of the diaphragm, which suggested a decrease in respiratory drive, while VT remained unchanged. The NVE increased with an increase in the depth of sedation. Minute ventilation and inspiratory duty cycle decreased with an increase in the depth of sedation, but this only achieved statistical significance between Ramsay 2 and both Ramsay 4 and 3 (P < 0.05). The ineffective triggering index increased with increasing sedation depth (9.5 ± 4.0%, 6.7 ± 2.0%, and 4.2 ± 2.1% for Ramsay 4, 3, and 2, respectively) and achieved statistical significance between each pair of depth of sedation (P < 0.05). The depth of sedation did not affect gas exchange. CONCLUSIONS: Propofol inhibits respiratory drive and deteriorates patient-ventilator synchrony to the extent that varies with the depth of sedation. Propofol has less effect on breathing pattern and has no effect on VT and gas exchange in postoperative patients with PSV.

Screening Allelochemical-Resistant Species of the Alien Invasive Mikania micrantha for Restoration in South China.

To screen allelochemical-resistant species of the alien invasive weed Mikania micrantha, we studied the allelopathic inhibition effects of the leaf aqueous extract (LAE) of Mikania on seed germination and seedling growth of the 26 species native or naturalized in the invaded region in South China. Seed germination was more strongly negatively affected by LAE than seedling growth. Responses of seed germination and seed growth to LAE differed differently among the target species. LAE more strongly negatively affected seed germination, but less strongly negatively affected seedling growth, in non-legume species than in legume species. LAE more strongly negatively affected seed germination and seedling growth in native species than naturalized exotic species. Therefore, naturalized exotic non-legume seedlings are more suitable than seeds of native legume species for restoration of Mikania-invaded habitats.

Characterization of a novel reassortant influenza A virus (H2N2) from a domestic duck in Eastern China.

While H2N2 viruses have been sporadically isolated from wild and domestic birds, H2N2 viruses have not been detected among human populations since 1968. Should H2N2 viruses adapt to domestic poultry they may pose a risk of infection to people, as most anyone born after 1968 would likely be susceptible to their infection. We report the isolation of a novel influenza A virus (H2N2) cultured in 2013 from a healthy domestic duck at a live poultry market in Wuxi City, China. Sequence data revealed that the novel H2N2 virus was similar to Eurasian avian lineage avian influenza viruses, the virus had been circulating for ≥ two years among poultry, had an increase in α2,6 binding affinity, and was not highly pathogenic. Approximately 9% of 100 healthy chickens sampled from the same area had elevated antibodies against the H2 antigen. Fortunately, there was sparse serological evidence that the virus was infecting poultry workers or had adapted to infect other mammals. These findings suggest that a novel H2N2 virus has been circulating among domestic poultry in Wuxi City, China and has some has increased human receptor affinity. It seems wise to conduct better surveillance for novel influenza viruses at Chinese live bird markets.

[A pilot study of diaphragmatic function evaluated as predictors of weaning in chronic obstructive pulmonary disease patients].

OBJECTIVE: To evaluate the predictive performance of neuro-mechanical coupling (NMC) and neuro-ventilatory coupling (NVC) in the weaning outcome in patients with chronic obstructive pulmonary disease (COPD). METHODS: Sixteen patients were enrolled when the criteria for their first spontaneous breathing trial (SBT) was met. A 30-minute SBT was attempted, with the measurement of electrical activity of the diaphragm (Edi), NMC, NVC, NVC × NMC, index of rapid shallow breathing (f/Vt), airway occlusion pressure (P(0.1)) and f/Vt × P(0.1) at 0, 5 and 30 min. The receiver operating characteristic (ROC) curve was calculated to evaluate the predictive performance of each index. RESULTS: Successful weaning (S group) was observed in 6 patients while weaning failure (F group) in 10 patients. (1) The predictive capacity of Edi: at 30 min of SBT, Edi showed higher values in the F group (P < 0.05), the area under the ROC curves (AUC) was 0.817(P < 0.05). (2) The predictive capacity of NVC and NMC: at 5, 30 min of SBT, NVC and NMC showed higher values in the S group (P < 0.05); at 30 min of SBT NVC presented the largest AUC than any other time of SBT (0.822, P < 0.05), while the AUC of NMC was 0.800(P > 0.05). (3) The predictive capacity of NVC × NMC: at 30 min of SBT, the AUC of NVC × NMC was larger than NVC (0.864, P < 0.05), showing greater sensitivity (100.0%) and specificity (83.3%). (4) The predictive capacity of f/Vt and P(0.1): f/Vt and f/Vt × P(0.1) presented poor predictive performance in the failed patients. CONCLUSIONS: Edi, NVC and NVC × NMC were good predictor for the weaning outcome in patients with COPD.

[Effects of neurally adjusted ventilatory assist on prevention of ventilator-induced diaphragmatic dysfunction in acute respiratory distress syndrome rabbits].

OBJECTIVE: To evaluate the effect of neurally adjusted ventilatory assist (NAVA) on prevention of ventilator-induced diaphragmatic dysfunction (VIDD) in ARDS rabbits. METHODS: Twenty New Zealand white rabbits were randomly divided into 4 groups: (1) control group (n = 5); (2) Volume control (VC) group (n = 5); (3) Pressure support (PSV) group (n = 5); (4) NAVA group (n = 5). In VC, PSV and NAVA groups, the rabbits were killed and the diaphragm was removed after 4 hours of ventilation. Animals in the control group were not mechanically ventilated, and the diaphragm was also removed immediately after anesthetizing. In all rabbits, malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione (GSH) of diaphragm were measured. Structure of diaphragm was observed by light microscope, electron microscope, constituent ratio and mean cross-sectional area (CSA) of diaphragm fiber. RESULTS: (1) MDA: Compared with the control [(0.15 ± 0.06) nmol/mg], PSV group [(0.30 ± 0.11) nmol/mg], there was no significant difference in MDA of diaphragm in NAVA group [(0.28 ± 0.19) nmol/mg] (F = 2.730, P > 0.05). MDA in VC group [(0.40 ± 0.16) nmol/mg] was significantly higher than the control group (P < 0.05). (2) SOD: Compared with control [(111 ± 12) U/mg], PSV group [(93 ± 4) U/mg], there was no significant difference in SOD of diaphragm in NAVA group [(94 ± 9) U/mg] (F = 4.422, P > 0.05). SOD in VC group [(80 ± 21) U/mg] was significantly lower than the control group (P < 0.05). (3) GSH: Compared with control [(5.3 ± 1.0) mg/g] and PSV group [(4.5 ± 1.2) mg/g], there was no significant difference in GSH of diaphragm in NAVA group [(5.6 ± 1.0) mg/g] (F = 3.001, P > 0.05). GSH in VC group [(3.3 ± 1.7) mg/g] is significantly lower than control and NAVA groups (P < 0.05). (4) Light microscope: In VC group, many changes were observed in the muscle, such as myelofibrosis, necrosis, and some of muscle fibers became atrophy, but these were no obvious changes of pathological structure in control, PSV or NAVA groups. (5) Electron microscope: In control, PSV and NAVA groups, the ultrastructure of diaphragm was normal. Different from the above 3 groups, some abnormal ultrastructure was observed in VC group, including disrupted myofibrils, swollen mitochondria. (6) CSA of diaphragm fiber: Compared with control and PSV group, there was no significant difference in CSA of diaphragm fiber in NAVA group (P > 0.05); The CSA of type II fibers in VC group was markedly lower than control group (P < 0.05). CONCLUSIONS: Compared with volume control ventilation, NAVA may mitigate diaphragmatic oxidative stress, atrophy and injury, and prevent VIDD better than VC.

[Effect of p38MAPK on proliferation in human embryonic lung fibroblasts in vitro].

OBJECTIVE: To study the proliferation effect of the AM supernatant incubated activation of p38 mitogen activated protein kinases (p38MAPK) signal transduction pathway in human embryonic lung fibroblasts, and to participate in the development of fibrosis in silicosis. METHODS: The silicotic alveolar macrophages were collected by bronchoalveolar lavage and incubated in vitro in the DMEM medium containing SiO2 (50 µg/ml) and DMEM medium without SiO2 for 18 h. Then the AM supernatant incubated for 18 h was collected. HELFs were isolated by organize paste block method, and incubated with AM supernatants. HELFs were divided into four groups: blank control groups, AM groups, SiO2 + AM groups, SB203580 + SiO2 + AM groups. The proliferation in the HELF was detected with MTT method and Flow cytometry. RESULTS: The proliferation in the HELF acted with the conditioned AM supernatant fluid were more than blank control groups, AM groups and SB203580 + SiO2 + AM groups [average optical density: (0.48 ± 0.03) vs (0.29 ± 0.01), (0.38 ± 0.02), (0.33 ± 0.03)], the values with MTT method were statistically different (P < 0.05); Proliferous index with flow cytometry in SiO2 + AM groups (18.12 ± 0.82) was bigger than blank control groups (9.24 ± 0.48), AM groups (14.76 ± 0.43) and SB203580 + SiO2 + AM groups (11.71 ± 0.70) and the values were statistically different(P < 0.05). CONCLUSIONS: The AM supernatant stimulated by silicon dioxide can accelerate the proliferation in the HELF by activation of p38MAPK signal transduction pathway.

Trends of superoxide dismutase and soluble protein of aquatic plants in lakes of different trophic levels in the middle and lower reaches of the Yangtze River, China.

A limnological study was carried out to determine the responses of superoxide dismutase (SOD) activities and soluble protein (SP) contents of 11 common aquatic plants to eutrophication stress. Field investigation in 12 lakes in the middle and lower reaches of the Yangtze River was carried out from March to September 2004. Our results indicated that non-submersed (emergent and floating-leafed) plants and submersed plants showed different responses to eutrophication stress. Both SOD activities of the non-submersed and submersed plants were negatively correlated with their SP contents (P < 0.000 1). SP contents of non-submersed plants were significantly correlated with all nitrogen variables in the water (P < 0.05), whereas SP contents of submersed plants were only significantly correlated with carbon variables as well as ammonium and Secchi depth (SD) in water (P < 0.05). Only SOD activities of submersed plants were decreased with decline of SD in water (P < 0.001). Our results indicate that the decline of SOD activities of submersed plants were mainly caused by light limitation, this showed a coincidence with the decline of macrophytes in eutrophic lakes, which might imply that the antioxidant system of the submersed plants were impaired under eutrophication stress.