Effect of the pat, fk, stpk Gene Knock-out and mdh Gene Knock-in on Mannitol Production in Leuconostoc mesenteroides.

Leuconostoc mesenteroides can be used to produce mannitol by fermentation, but the mannitol productivity is not high. Therefore, in this study modify the chromosome of Leuconostoc mesenteroides by genetic methods to obtain high-yield strains of mannitol production. In this study, gene knock-out strains and gene knock-in strains were constructed by a two-step homologous recombination method. The mannitol productivity of the pat gene (which encodes phosphate acetyltransferase) deleteon strain (Δpat::amy), fk gene (which encodes fructokinase) deleteon strain (Δfk::amy) and stpk gene (which encodes serine-threonine protein kinase) deleteon strain (Δstpk::amy) were all increased compared to the wild type, and the productivity of mannitol for each strain was 84.8%, 83.5% and 84.1% respectively. The mannitol productivity of the mdh gene (which encodes mannitol dehydrogenase) knock-in strains (Δpat::mdh, Δfk::mdh and Δstpk::mdh) was increased to a higher level than that of the single-gene deletion strains, and the productivity of mannitol for each was 96.5%, 88% and 93.2%, respectively. The multi-mutant strain ΔdtsΔldhΔpat::mdhΔstpk::mdhΔfk::mdh had mannitol productivity of 97.3%. This work shows that multi-gene knock-out and gene knock-in strains have the greatest impact on mannitol production, with mannitol productivity of 97.3% and an increase of 24.7% over wild type. This study used the methods of gene knock-out and gene knock-in to genetically modify the chromosome of Leuconostoc mesenteroides. It is of great significance that we increased the ability of Leuconostoc mesenteroides to produce mannitol and revealed its broad development prospects.

Relación entre la expresión de IL-2 e IL-4 y sus polimorfismos y los riesgos de padecer infección por Mycoplasma pneumoniae y asma en niños / Associations of IL-2 and IL-4 Expression and Polymorphisms With the Risks of Mycoplasma pneumoniae Infection and Asthma in Children

Introducción: El asma es una afección inflamatoria de las vías respiratorias. Las infecciones porMycoplasma pneumoniae pueden exacerbar los síntomas del asma. Se ha demostrado que la interleucina2 y la interleucina4 participan en las reacciones inmunitarias e inflamatorias. Hemos estudiado la relación entre los polimorfismos de la IL2 y la IL4 y su expresión y el riesgo de padecer asma e infección por M.pneumoniae en niños. Métodos: Se reclutó a 392 niños asmáticos y 849 controles para el estudio. Se genotiparon 8 polimorfismos en IL2 e IL4 con la plataforma MassARRAY de Sequenom. La infección por M.pneumoniae y el número de copias se establecieron mediante PCR fluorescente. Los niveles séricos de expresión de IL-2 e IL-4 se midieron con ELISA. Resultados: Hallamos una relación significativa entre el polimorfismo rs6534349 de IL2 y el aumento de riesgo de sufrir asma (heterocigóticos, p = 0,029; variantes homocigóticas, p = 0,013), así como entre el polimorfismo rs2227284 de IL4 y una reducción del riesgo de padecer asma (heterocigóticos, p = 0,026; variantes homocigóticas, p = 0,001). Además, la relación con otros polimorfismos, excepto el rs2070874, se hizo evidente al agrupar a los niños asmáticos según la clasificación GINA de control y gravedad del asma. Asimismo, los niveles séricos de expresión de IL-2 e IL-4 fueron significativamente mayores en los sujetos no infectados (p = 0,038) e infectados (p = 0,011) por M.pneumoniae, respectivamente. Esta observación también se cumple entre los pacientes asmáticos (p = 0,016 para IL-2 y p = 0,042 para IL-4), pero en los controles no asmáticos solo se cumple en el caso de la IL-4 (p = 0,032). Del mismo modo, observamos que el genotipo GG rs6534349 estaba claramente relacionado con un aumento de las posibilidades de tener una infección con alta carga de M.pneumoniae (p = 0,0376). Conclusiones: La IL2 y la IL4 podrían ser biomarcadores importantes para calcular el riesgo de padecer asma, así como infección por M.pneumoniae, en niños

Introduction: Asthma is an inflammatory disorder of the airways and the symptoms of asthma could be exacerbated by Mycoplasma pneumoniae infection. Interleukin-2 and interleukin-4 have been implicated in immune and inflammatory reactions. We examined the associations of IL2 andIL4 polymorphisms and expression with the risks of asthma and M. pneumoniae infection in children. Methods: 392 asthmatic children and 849 controls were recruited into the study. Eight polymorphisms inIL2 and IL4 were genotyped with Sequenom MassARRAY platform. M. pneumoniae infection and copy number was determined with fluorescence PCR. IL-2 and IL-4 serum expression levels were determined by using ELISA. Results: We found a significant association of IL2 rs6534349 polymorphism with increased asthma risk (heterozygotes, P = .029; homozygous variants; P = .013) and of IL4 rs2227284 polymorphism with reduced asthma risk (heterozygotes, P = .026; homozygous variants; P = .001). Besides, the association of other polymorphisms, except rs2070874 polymorphism, became apparent when the asthmatic children were grouped according to GINA classification of asthma control and severity. In addition, IL-2 and IL-4 serum expression levels were significantly higher in M. pneumoniae negative (P = .038) and positive (P = .011) subjects respectively. This observation holds true among asthmatic patients (P = .016 for IL-2 and P = .042 for IL-4), but only the IL-4 observation remained correct among non-asthmatic controls (P = .032). We also observed that the rs6534349 GG genotype was significantly associated with increased odds of getting high load M. pneumoniae infection (P = .0376). Conclusions: IL2 and IL4 could be important biomarkers for estimating the risks of asthma and M. pneumoniae infection in children

Early and late Iron supplementation for low birth weight infants: a meta-analysis.

BACKGROUND: Iron deficiency in infancy is associated with a range of clinical and developmentally important issues. Currently, it is unclear what is the optimal timing to administer prophylactic enteral iron supplementation in preterm and very low birth weight infants. The objective of this meta-analysis was to evaluate early compared with late iron supplementation in low birth weight infants. METHODS: PubMed and Cochrane Library databases were searched up to May 10, 2014 for studies that compared the benefit of early and late iron supplementation in infants of low birth weight. Sensitivity analysis was carried out using the leave one-out approach and the quality of the included data was assessed. RESULTS: The data base search and detailed review identified four studies that were included in the meta-analysis. The number of included patients was 246 (n=121 for early supplementation and n=125 for late supplementation) and the majority were premature infants. Across studies, early supplementation ranged from as early as enteral feeding was tolerated to 3 weeks, and late supplementation ranged from 4 weeks to about 60 days. Early treatment was associated with significantly smaller decreases in serum ferritin and hemoglobin levels (P<0.001). In addition, the rate of blood transfusions was lower with early compared with late iron supplementation (P=0.022). There was no difference between early and late supplementation in the number of patients with nectorizing enteroclitis (>bell stage 2) (P=0.646). Sensitivity analysis indicated no one study overly influenced the findings and that the data was reliable. CONCLUSION: In conclusion, early iron supplementation resulted in less a decrease in serum ferritin and hemoglobin levels in infants with low birth rate. However, caution should be used when treating infants with iron so as not to result in iron overload and possibly negative long-term effects on neurodevelopment.

Associations of IL-2 and IL-4 Expression and Polymorphisms With the Risks of Mycoplasma pneumoniae Infection and Asthma in Children.

INTRODUCTION: Asthma is an inflammatory disorder of the airways and the symptoms of asthma could be exacerbated by Mycoplasma pneumoniae infection. Interleukin-2 and interleukin-4 have been implicated in immune and inflammatory reactions. We examined the associations of IL2 and IL4 polymorphisms and expression with the risks of asthma and M. pneumoniae infection in children. METHODS: 392 asthmatic children and 849 controls were recruited into the study. Eight polymorphisms in IL2 and IL4 were genotyped with Sequenom MassARRAY platform. M. pneumoniae infection and copy number was determined with fluorescence PCR. IL-2 and IL-4 serum expression levels were determined by using ELISA. RESULTS: We found a significant association of IL2 rs6534349 polymorphism with increased asthma risk (heterozygotes, P=.029; homozygous variants; P=.013) and of IL4 rs2227284 polymorphism with reduced asthma risk (heterozygotes, P=.026; homozygous variants; P=.001). Besides, the association of other polymorphisms, except rs2070874 polymorphism, became apparent when the asthmatic children were grouped according to GINA classification of asthma control and severity. In addition, IL-2 and IL-4 serum expression levels were significantly higher in M. pneumoniae negative (P=.038) and positive (P=.011) subjects respectively. This observation holds true among asthmatic patients (P=.016 for IL-2 and P=.042 for IL-4), but only the IL-4 observation remained correct among non-asthmatic controls (P=.032). We also observed that the rs6534349 GG genotype was significantly associated with increased odds of getting high load M. pneumoniae infection (P=.0376). CONCLUSIONS: IL2 and IL4 could be important biomarkers for estimating the risks of asthma and M. pneumoniae infection in children.

Comparison of risk factors for recurrent respiratory infections between urban and rural preschool children in Yiwu, China.

BACKGROUND: Many studies have shown an association between the risk of increased recurrent respiratory infections and socioeconomic and fostering factors, but often only a few risk factors have been studied. This study aimed to identify and compare such factors between urban and rural preschool children. METHODS: Case control studies were conducted in Yiwu urban and rural areas respectively in Zhejiang Province. A structured questionnaire was used to collect information on influencing factors such as socioeconomic factors, fostering factors, and housing conditions. The chi-square test was used to compare the distribution of some health related factors between urban and rural children. Risk factor analyses were also made in urban and rural children respectively. Univariate and multivariate analyses were made using the binary logistic regression. RESULTS: Multivariate analysis showed that maternal age (OR=0.94, 95%CI: 0.89-0.99), asthma (OR=2.34, 95%CI: 1.22-4.48), rickets (OR=5.03, 95%CI: 2.10-12.05), snack (OR=1.62, 95%CI: 1.19-2.20), traffic mode (OR=1.38, 95%CI: 1.03-1.86), living with patients with chronic respiratory system disease (OR=1.79, 95%CI: 1.02-3.15), and indoor passive smoking (OR=1.46, 95%CI: 1.02-2.10) were the influencing factors for recurrent respiratory infections in urban children. Rickets (OR=3.77, 95% CI: 1.13-12.65) and passive smoking (OR=2.33, 95% CI: 1.17-4.65) were the influencing factors for recurrent respiratory infections in rural children. CONCLUSIONS: Public health measures against risk factors should be taken to prevent the occurrence of recurrent respiratory infections in urban and rural children respectively.

Follow-up study for newborns and infants who failed hearing screening / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To study the audiological characteristics of newborns and infants who failed hearing screening.</p><p><b>METHODS</b>One hundred and six infants failed hearing screening received follow-up study with routine audiological evaluations (auditory brainstem response, distortion product otoacoustic emission, tympanometry and visual reinforcement audiometry).</p><p><b>RESULTS</b>Sixty-five infants (61.3%) of this group were normal hearing subjects and 39(36. 8% ) of the infants had hearing loss. Two cases (1.9%) received follow-up by phone. Fifteen cases (14.2%) with conductive hearing loss and 24 cases (22.6%) with sensorineural hearing loss. Thirteen (12.3%), 14 (13.2%), 6 (5.7%), and 6 (5.7%) cases were found to be mild, moderate, severe and profound hearing loss respectively. Diagnosis of hearing loss in the thirty-nine infants conducted a prevalence of 0.264% (39/14 785) of congenital hearing loss (both binaural and monaural). The hearing level of those cases with severe and profound hearing loss basically did not change, but that of cases with mild and moderate hearing loss changed.</p><p><b>CONCLUSIONS</b>Early identification and intervention of infants with severe and profound hearing loss by 6 months of age were successful. Infants with mild and moderate hearing loss should be followed up to six or eight months and received routine audiologic evaluations.</p>