Proteomic analysis of mycelial proteins from Magnaporthe oryzae under nitrogen starvation.

Magnaporthe oryzae is an important model system in studies of plant pathogenic fungi, and nitrogen is a key nutrient source affecting microbial growth and development. In order to understand how nitrogen stress causes changes in mycelial proteins, we analyzed differentially expressed mycelial proteins from the M. oryzae virulent strain CH-63 using two-dimensional electrophoresis and mass spectrometry in complete medium or under nitrogen starvation conditions. A total of 975 ± 70 and 1169 ± 90 protein spots were detected in complete medium and under nitrogen starvation conditions, respectively. Forty-nine protein spots exhibited at least 2-fold up-regulation or down-regulation at the protein level according to PDQuest7.4. Moreover, 43 protein spots were successfully identified by matrix-assisted laser desorption/ionization-time-of-flight/time-of-flight mass spectrometry. Among these spots, 6 proteins were functionally unknown and 37 proteins were categorized into 5 groups according to their functions, including development, metabolism, biosynthesis, and biological process. These 37 proteins were further analyzed for their enriched metabolic pathways by KOBAS2.0, and 14 proteins were found to be involved in glycolysis, tricarboxylic acid cycle, and nitrogen metabolism. Taken together, the regulation of M. oryzae growth under the nitrogen starvation conditions appears to be complex because of the various proteins and enzymes involved.

A meta-analysis of probiotics for preventing necrotizing enterocolitis in preterm neonates

Necrotizing enterocolitis (NEC) is one of the most common acquired diseases of the gastrointestinal tract in preterm infants. Some randomized, controlled trials (RCTs) have indicated that probiotics may potentially lower the incidence of NEC and mortality. However, debate still remains about the safety of probiotics and their influence on normal infant growth. We performed this meta-analysis to assess the safety and benefits of probiotic supplementation in preterm infants. We searched in PubMed, Embase, and Cochrane databases for English references, and in Wanfang, VIP, and CNKI databases for Chinese references. Ultimately, 27 RCTs (including 9 Chinese articles) were incorporated into this meta-analysis. Relative risk (RR) and weighted mean difference (WMD) were calculated using a random-effects or fixed-effects model, depending on the data type and heterogeneity. A total of 6655 preterm infants, including the probiotic group (n=3298) and the placebo group (n=3357), were eligible for inclusion in this meta-analysis. For Bell stage ≥I and gestational age <37 weeks, risk of NEC incidence was significantly lower in the probiotic group [RR=0.35, 95% confidence interval (CI)=0.27-0.44, P<0.00001]. For Bell stage ≥II or gestational age <34 weeks, there were likewise significant differences between the probiotic and placebo groups concerning NEC incidence (RR=0.34, 95%CI=0.25-0.48, P<0.00001; and RR=0.39, 95%CI=0.27-0.56, P<0.00001). Risk of death was significantly reduced in the probiotic group (RR=0.58, 95%CI=0.46-0.75, P<0.0001). In contrast, there was no significant difference concerning the risk of sepsis (RR=0.94, 95%CI=0.83-1.06, P=0.31). With respect to weight gain and the age at which infants reached full feeds, no significant differences were found between the probiotic and placebo groups (WMD=1.07, 95%CI=−0.21-2.34, P=0.10; and WMD=−1.66, 95%CI=−3.6-0.27, P=0.09). This meta-analysis has shown that, regardless of gestational age and NEC stage, probiotic supplementation could significantly reduce the risk of NEC in preterm infants. Analysis also indicated that such supplementation did not increase the incidence risk of sepsis or of mortality. Finally, the study showed that probiotic supplementation may have no adverse effect on normal feeding and growth.

A meta-analysis of probiotics for preventing necrotizing enterocolitis in preterm neonates.

Necrotizing enterocolitis (NEC) is one of the most common acquired diseases of the gastrointestinal tract in preterm infants. Some randomized, controlled trials (RCTs) have indicated that probiotics may potentially lower the incidence of NEC and mortality. However, debate still remains about the safety of probiotics and their influence on normal infant growth. We performed this meta-analysis to assess the safety and benefits of probiotic supplementation in preterm infants. We searched in PubMed, Embase, and Cochrane databases for English references, and in Wanfang, VIP, and CNKI databases for Chinese references. Ultimately, 27 RCTs (including 9 Chinese articles) were incorporated into this meta-analysis. Relative risk (RR) and weighted mean difference (WMD) were calculated using a random-effects or fixed-effects model, depending on the data type and heterogeneity. A total of 6655 preterm infants, including the probiotic group (n=3298) and the placebo group (n=3357), were eligible for inclusion in this meta-analysis. For Bell stage ≥I and gestational age <37 weeks, risk of NEC incidence was significantly lower in the probiotic group [RR=0.35, 95% confidence interval (CI)=0.27-0.44, P<0.00001]. For Bell stage ≥II or gestational age <34 weeks, there were likewise significant differences between the probiotic and placebo groups concerning NEC incidence (RR=0.34, 95%CI=0.25-0.48, P<0.00001; and RR=0.39, 95%CI=0.27-0.56, P<0.00001). Risk of death was significantly reduced in the probiotic group (RR=0.58, 95%CI=0.46-0.75, P<0.0001). In contrast, there was no significant difference concerning the risk of sepsis (RR=0.94, 95%CI=0.83-1.06, P=0.31). With respect to weight gain and the age at which infants reached full feeds, no significant differences were found between the probiotic and placebo groups (WMD=1.07, 95%CI=-0.21-2.34, P=0.10; and WMD=-1.66, 95%CI=-3.6-0.27, P=0.09). This meta-analysis has shown that, regardless of gestational age and NEC stage, probiotic supplementation could significantly reduce the risk of NEC in preterm infants. Analysis also indicated that such supplementation did not increase the incidence risk of sepsis or of mortality. Finally, the study showed that probiotic supplementation may have no adverse effect on normal feeding and growth.

MicroRNA expression profiling studies on bronchopulmonary dysplasia: a systematic review and meta-analysis.

Over the past several years, several microRNA (miRNA) expression profiling studies have been carried out on bronchopulmonary dysplasia (BPD) in mammalian lung tissues. The most effective way to identify these important miRNAs is to systematically search for similar signatures identified in multiple independent studies. Accordingly, a meta-analysis was conducted to review published miRNA expression profiling studies that compared miRNA expression profiles between BPD lung tissues and normal lung tissues. A vote-counting strategy that considered the total number of studies and time points reporting differential expression was applied. Furthermore, cut-off criteria of statistically significant differentially expressed miRNAs as defined by the author and their predicted target genes, if available, as well as the list of up- and down-regulated miRNA features, were collected and recorded. Results of the meta-analysis revealed that four up-regulated miRNAs (miRNA-21, miRNA-34a, miRNA-431, and Let-7f) and one down-regulated miRNA (miRNA-335) were differentially expressed in BPD lung tissues compared with normal groups. In addition, eight miRNAs (miRNA-146b, miRNA-29a, miRNA-503, miRNA-411, miRNA-214, miRNA-130b, miRNA-382, and miRNA-181a-1*) were found to show differential expression not only in the process of normal lung development, but also during the progress of BPD. Finally, several meaningful target genes (such as the HPGD and NTRK genes) of common miRNAs (such as miRNA-21 and miRNA-141) were systematically predicted. These specific miRNAs may provide clues of the potential mechanisms involved in BPD. Further mechanistic and external validation studies are needed to confirm the clinical significance of these miRNAs in the development of BPD.