Current status of exclusive breastfeeding for the second child and factors influencing exclusive breastfeeding in the context of the universal two-child policy / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate the current status of exclusive breastfeeding for the second child in the context of the universal two-child policy and the factors influencing exclusive breastfeeding.</p><p><b>METHODS</b>A self-designed questionnaire for the current status of breastfeeding and related factors influencing breastfeeding for the second child were used to survey 836 mothers with a second child, who were selected by cluster sampling, in Quzhou, Zhejiang, China.</p><p><b>RESULTS</b>A total of 680 usable questionnaires were obtained. The rate of exclusive breastfeeding for the second child was significantly lower than for the first child (34.9% vs 42.2%; P<0.05). The univariate analysis revealed that there were significant differences between the exclusive and non-exclusive breastfeeding groups in the mother′s age, education background, occupation and time of maternity leave, mode of delivery of the first child, sex of the first child, feeding pattern of the first child, mode of delivery of the second child, whether the second child was admitted to the intensive care unit, whether the father supported breastfeeding, and whether the grandmother/maternal grandmother supported breastfeeding (P<0.05). The multivariate logistic regression analysis showed that artificial feeding+partial breastfeeding for the first child (OR=12.286, P<0.05), cesarean section for the second child (OR=1.724, P<0.05), and having no breastfeeding support from the maternal grandmother (OR=1.651, P<0.05) were main factors for influencing exclusive breastfeeding.</p><p><b>CONCLUSIONS</b>The current status of exclusive breastfeeding for the second child is not optimistic in the context of the universal two-child policy. Education about breastfeeding should be taken seriously at the birth of the first child, the rate of cesarean section should be reduced, and the family members should support exclusive breastfeeding, in order to improve the status of exclusive breastfeeding.</p>

Efects of Inhibiting miR-155 Expression on the Proliferation and Apoptosis of Leukemia THP-1 Cells / 中国实验血液学杂志

The aim of this study was to investigate the effects of miR-155 inhibitor transfection on the proliferation and apoptosis of THP-1 cells. The miR-155 inhibitor was transfected into THP-1 cells (THP-1I) by using X-treme GENE siRNA transfection reagent. Cells without transfection (THP-1C) and cells with negative transfection (THP-1IC) were used as controls. Quantitative real-time polymerase chain reaction (RT-PCR) was performed to detect the expression of miR-155 and relative expression of SHIP1 mRNA in the cells. Cell proliferation was assayed using CCK-8 method. Cell apoptosis were detected by flow cytometry. The expression of SHIP1, TAKT and pAKT in THP-1 cells were detected by Western blot. The results indicated that compared with THP-1C and THP-1IC, the expression of miR-155 in THP-1I cells was significantly reduced; miR-155 inhibition significantly increased apoptosis rate in THP-1 cells (P < 0.05) ; miR-155 inhibition in THP-1 cells caused no significant alteration in SHIP1 mRNA level but significantly increased its protein content, indicating some post-transcriptional modulations might exist underlying the modulation of miR-155 to SHIP1, the miR-155 caused significantly reduced protein level of pAKT (P < 0.05) without interfering TAKT protein content. It is concluded that the miR-155 inhibition may promote THP-1 cell apoptosis through increasing SHIP1 protein content and impairing its downstream PI3K/AKT signaling pathway. This study suggests that miR-155 inhibition may be a promising therapy strategy for treating acute myeloid leukemia (AML).

Cloning and superexpression of cry1Ac gene from 20kb DNA associated with Bacillus thuringiensis Cry1A Crystal Protein / 生物工程学报

The CrylA Crystal Protein from Bacillus thuringiensis is associated with DNA, but the role and sequences of these DNA molecules are unknown. CrylA bipyramidal crystals from B. thuringiensis strain 4.0718 was selectively dissolved and associated DNA was extracted from protoxin. The DNA was digested with Nde I to obtain 3 to 5 kb fragments and then the fragments were subcloned into pMD18-T vector, screening of recombinants were done by PCR-RFLP and sequencing. The ORF of cry1Ac gene was amplified by primers designed and then subcloned. The 3.5 kb BamH I and Sal I fragments of pMDX35 was inserted into the pET30a vector, giving 8.9 kb recombinant plasmid, pETX35. ETX35 strain were obtained by transformed pETX35 into B121 (DE3). A 141 kD fusion protein was superexpressed as inclusion bodies. Quantitative protein analysis indicated that the amount of 141 kD protein was above the level of 51.36% of total cellular protein. Plasmid pHTX42 constructed from shuttle vector pHT304 was transformed B. thuringiensis acrystalliferous strain XBU001 with electroporation to obtain the recombinant HTX42. The recombinant protein was found with a molecular mass of 130 kD on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Scanning analysis indicated that the expressed protein accounted up to 79.28% of total cellular proteins and accumulated in the cells mounted up to 64.13% of cellular dry weight. Under Atomic Force Microscopy (AFM), typical bipyramidal crystals from HTX42 strain were found with a size of 1.2 microm x 2.0 microm. Bioassay showed that these inclusion bodies of ETX35 strain and crystals from HTX42 strain were highly toxic against the larvae of Plutella xylostella. On such a base, constructing insecticidal recombinant and analyzing the source, structure, and function of the 20 kb DNA can be further achieved.