Breastfeeding promotion strategies study on preterm infants in the neonatal intensive care unit / 北京大学学报(医学版)

OBJECTIVE@#To explore the effect of breastfeeding promotion strategies on neonatal clinical outcomes of preterm infants during hospitalization in the neonatal intensive care unit (NICU).@*METHODS@#We developed breastfeeding promotion strategies, including the establishment of a multidisciplinary breastfeeding steering team, breastfeeding support of families and society, family-integrated care, kangaroo mother care, donor human milk bank, and so on. Preterm infants meeting the inclusion standard, less than 32 weeks gestational age, who were admitted to NICU from November 2015 to February 2017 were enrolled, and the eligible infants were divided into two groups (control group and intervention group) before and after policy implementation. The data of preterm infants including breastfeeding related outcomes (time to initiation of enteral feeding, time to initiation of breastfeeding, time to achieve full breastfeeding, time to achieve full enteral feeding and rate of breastfeeding), growth (extrauterine growth restriction) and complications were compared between the two groups.@*RESULTS@#One hundred and twenty-three preterm infants were enrolled, including 61 in the control group and 62 in the intervention group. There were no significant differences in gender, gestational age, birth weight, intrauterine growth retardation (IUGR) and admission disease status between the two groups (P>0.05). Compared with the control group, there were significantly earlier time to initiation of enteral feeding [15.37 (10.00, 22.13) h vs. 20.25 (12.88, 26.33) h, P<0.01], time to achieve full breastfeeding [91.00 (69.75, 103.00) h vs. 94.00 (80.37, 118.75) h, P=0.04], and time to achieve full enteral feeding [12 (11, 15) d vs. 14 (12, 18) d, P<0.01] in the intervention group. Otherwise, there were no significant differences in time to initiation of breastfeeding, hospital stay, extrauterine growth restriction (EUGR) occurance rate of weight, the rate of breastfeeding, motality, and the incidence of complications including feeding intolerance, neonatal necrotizing enterocolitis (NEC), bronchopulmonary dysplasia (BPD) and retinopathy of prematurity (ROP) (P>0.05).@*CONCLUSION@#The breastfeeding promotion strategie was a quality improvement of ordinary breastfeeding protocol. It had significantly reduced time to initiation of enteral feeding, time to achieve full breastfeeding and time to achieve full enteral feeding for preterm infants in NICU. Further research is needed to confirm whether the strategies can improve the breastfeeding rate and reduce the occurrence of the complications, such as NEC, BPD, and ROP.

Effect of different feeding initiation formulas on very low birth weight infants / 中国当代儿科杂志

OBJECTIVE@#To explore the effect of feeding initiation with different formulas on the growth, development, and feeding tolerance in very low birth weight infants.@*METHODS@#A total of 86 preterm infants with a gestational age of 0.05). The SPF and eHF groups had a significantly shorter transition time from meconium to yellow stool than the control group (P0.05).@*CONCLUSIONS@#Both eHF and SPF can be used for feeding initiation for very low birth weight preterm infants with a gestational age of <34 weeks without increasing the incidence rate of EUGR.

Preparation and biomechanical properties of acellularized nerve scaffold using the technique of hypotonic buffer combined with freeze-drying / 医用生物力学

Objective To study the morphology and biomechanical properties of the improved acellularized nerve scaffold using the technique of hypotonic buffer combined with freeze-drying. Methods The traditional acellularized nerve scaffold (traditional group) was made to be improved with the technique of hypotonic buffer combined with freeze-drying (improved group). After the acellularization process was completed, the histological structure of nerves in each group was observed by HE staining and scanning electron microscope. The interval porosity and void diameter in each group were measured by Mimics software. The biomechanical properties of nerves in each group were tested by mechanical apparatus (Endura TEC ELF3200). Results The acellularization effect of the improved chemical method with the technique of hypotonic buffer combined with freeze-drying was similar to that of the traditional Hudson method, but the histological structure was more porous in improved group than that in traditional group. The interval porosity of traditional group and improved group were 34.5% and 49.3%, respectively; the void diameter of traditional group and improved group were 11.96 and 17.61 μm, respectively. Biomechanical testing results showed that there was no statistical difference in ultimate load, ultimate stress, ultimate strain and mechanical work to fracture in each group (P>0.05). Conclusions The acellularized nerve prepared by hypotonic buffer combined with freeze-drying can be used as a new kind of nerve scaffold material to make better contribution to cell combination.

Effects of different decellularization methods on biomechanical properties and histological structure of annulus fibrosus in pigtail / 医用生物力学

Objective To investigate effects of different de-cellularization methods on biomechanical properties and histological structure of annulus fibrosus in pigtails and provide experimental evidence for the construction of tissue engineering annulus fibrosus. Methods Sixty Fresh annulus fibrosus were dissected from caudal disks of pigs and randomly assigned to 4 groups with 15 in each group. Triton X-100 group(Group A): annulus fibrosus were treated with hypotonic Tris-HCl buffer for 48 hours and de-cellularized with Triton X-100, DNase Ⅰ and RNase A. SDS group (Group B): annulus fibrosus were subjected to 3 cycles of freeze-thaw and subsequently de-cellularized with SDS, DNaseⅠ and RNase A. Trypsin group (Group C): annulus fibrosus were de-cellularized with Tris buffer containing trypsin, DNase Ⅰ and RNase A. Control group: fresh annulus fibrosus underwent no treatment. After the de-cellularization process was completed, hematoxylin-eosin (HE) staining was carried out to examine the efficacy on cell removal, and the ultrastructure of annulus fibrosus were observed by scanning electron microscopy. The collagen content, glycosaminoglycan (GAG) content and biomechanical parameters in each group were also detected. Results HE staining and scanning electron microscopy showed that no residual cells were found in Group A, B and C. The structure of annulus fibrosus in Group A was not disturbed, while that in Group B and C was damaged severely and slightly, respectively. There was no statistical difference in collagen content among Group A, B and C, as compared to the control group (P>0.05). But the GAG content was significantly more lower in Group A, B and C than in the control group (P0.05), while these parameters of Group B were lower than those in the control group (P<0.05). Conclusions The Triton X-100-treated annulus fibrosus retained the major extracellular matrix composition after cell removal and preserved the major structure and mechanical strength, which is preferable for the construction of tissue engineering annulus fibrosus.

Stress analysis and biocompatibility research on a cell carrier with silicone rubber membrane / 医用生物力学

Objective To report a self-developed cell carrier made of silicone rubber membrane, and to calculate the strain distributions on the membrane and analyze biocompatibility of the silicone rubber by three dimensional (3D) finite element method (FEM) so as to make a comprehensive evaluation on this silicon rubber membrane and provide theoretical basis for cellular research under stress stimulation. Methods The silicon rubber was made into a membrane with the thickness of 0.1 cm. Based on elastic modulus and Poisson’s ratio of the silicone rubber membrane, 3D FEM was used to simulate the deformation of the membrane induced by the stretch stress. MTT method was used to compare the growing situation of cells cultured on the silicone membranes and in standard plastic plates, respectively. Embedding experiment was also conducted to find out whether the material had biological toxicity or not. ResultsUnder the loading of 0.5%~20% strain, the area with effective strain was in the center of the membrane, accounting for 90% of the total area. There still existed some differences in biocompatibility between the silicon rubber membrane and standard plastic plate, but the material itself showed no toxicity. Conclusions Stress distributions on the surface of this self-developed silicon rubber membrane and its biocompatibility were generally acceptable for cell culture, but its surface should be further improved to fit for cell stress experiment.

Biomechanical properties of peripheral nerve after acellular treatment / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Peripheral nerve injury causes a high rate of disability and a huge economic burden, and is currently one of the serious health problems in the world. The use of nerve grafts plays a vital role in repairing nerve defects. Acellular nerve grafts have been widely used in many experimental models as a peripheral nerve substitute. The purpose of this study was to test the biomechanical properties of acellular nerve grafts.</p><p><b>METHODS</b>Thirty-four fresh sciatic nerves were obtained from 17 adult male Wistar rats (age of 3 months) and randomly assigned to 3 groups: normal control group, nerve segments underwent no treatment and were put in phosphate buffered saline (pH 7.4) and stored at 4°C until further use; physical method group, nerve segments were frozen at -196°C and then thawed at 37°C; and chemical method group, nerve segments were chemically extracted with the detergents Triton X-200, sulfobetaine-10 (SB-10) and sulfobetaine-16 (SB-16). After the acellularization process was completed, the structural changes of in the sciatic nerves in each group were observed by hematoxylin-eosin staining and field emission scanning electron microscopy, then biomechanical properties were tested using a mechanical apparatus (Endura TEC ELF 3200, Bose, Boston, USA).</p><p><b>RESULTS</b>Hematoxylin-eosin staining and field emission scanning electron microscopy demonstrated that the effects of acellularization, demyelination, and integrity of nerve fiber tube of the chemical method were better than that of the physical method. Biomechanical testing showed that peripheral nerve grafts treated with the chemical method resulted in some decreased biomechanical properties (ultimate load, ultimate stress, ultimate strain, and mechanical work to fracture) compared with normal control nerves, but the differences were not statistically significant (P > 0.05).</p><p><b>CONCLUSION</b>Nerve treated with the chemical method may be more appropriate for use in implantation than nerve treated with the physical method.</p>

Study on the association of SNPs of MMP-2 and TIMP-2 genes with the risk of endometriosis and adenomyosis / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the association of single nucleotide polymorphisms (SNPs) in matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of metalloproteinase-2 (TIMP-2) with the risk of endometriosis and adenomyosis.</p><p><b>METHODS</b>Genotypes of MMP-2 and TIMP-2 were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method among 298 endometriosis patients, 180 adenomyosis patients and 324 matched control women.</p><p><b>RESULTS</b>No significant difference was found in allele frequencies and genotype distributions of MMP-2 -1306C/T polymorphism between endometriosis patients and control women (P> 0.05). However, there were significant differences in genotype and allele distributions of MMP-2 -1306C/T polymorphism between adenomyosis patients and control women (P< 0.05). Compared with CT+TT genotypes, CC genotype significantly increases the risk of adenomyosis, with an odds ratio of 1.83 (95% CI was 1.13-2.96). No significant difference was shown in allele frequencies and genotype distributions of the MMP-2 -735C/T polymorphism among the three groups (P>0.05). MMP-2 -1306C/T and -735C/T polymorphisms displayed linkage disequilibrium (D'=0.74). There was no significant difference in haplotype distributions of the two MMP-2 SNPs among the three groups ( P> 0.05). No significant difference was found in allele frequencies of TIMP-2 -418G/C polymorphism among the three groups (P> 0.05). However, the frequency of TIMP-2 CC genotype in endometriosis patients (0.7%) was significantly lower than that in the control women (3.7%) (P< 0.05).</p><p><b>CONCLUSION</b>The C allele of MMP-2 -1306C/T polymorphism did not modify the risk of developing endometriosis but significantly increase the risk of developing adenomyosis. The MMP-2 -735C/T and TIMP-2 -418G/C polymorphisms were not associated with the risk of developing endometriosis or adenomyosis.</p>

Analysis on genetic diversity of different Salvia miltiorrhiza geographical populations in China / 中国中药杂志

<p><b>OBJECTIVE</b>To research on genetic diversity of different Salvia miltiorrhiza geographical populations in China.</p><p><b>METHOD</b>The genetic diversity of 27 S. miltiorrhiza geographical populations from ten provinces in China was estimated using amplified fragment length polymorphism (AFLP) markers. The data of amplified bands were analyzed by the software POPGENE and SPSS.</p><p><b>RESULT</b>The ten primers employed produced a total of 528 discernable and reproduceable amplified fragments. There were 476 polymorphic brands. The percentage of polymorphic bands with in different populations was 90.15%. Genetic diversity analysis showed that Neis gene diversity (He) was 0.261 2 and Shannon's genetic diversity index (1) was 0.403 3. The coefficient of gene similarity was 0.504 0-0.789 0 between populations. The cluster map including all samples were obtained by UPGMA. In the map, there were seven cluster groups and one individual outside the groups.</p><p><b>CONCLUSION</b>The genetic diversity with in different geographical population of S. miltiorrhiza in China is plentiful.</p>

Construction and Functional Analysis of a Synthetic Wound-and Hormone-inducible Promoter ocs/mas / 中国生物工程杂志

The use of optimal regulatory sequences for simultaneous expression of the transgenes might play a significant role in engineering plants with increased disease and insect resistance.The plant expression vector pOMS-GUS,which contained the GUS gene under the control of a chimeric promoter based upon the mannopine synthase(mas)promoter and the octopine synthase(ocs)enhancer,was constructed.Used as control,another vector pMAS-GUS,carried the GUS gene driven by only the mas promoter.The two vectors were introduced into tobacco plants by Agrobacterium-mediated transformation.Fluorometric assays for GUS activity and reverse transcription-polymerase chain reaction(RT-PCR)analysis revealed that GUS gene expressed weakly with untreated transgenic tobacco while the level of GUS activity increased steadily after 1 h subjected to wounding.The expression of the mas and ocs/mas promoters was induced a further 1.8-fold and 5.7-fold,respectively.SA(1 mmol/L)or MJ(250 ?mol/L)treatment also caused a large induction of the ocs/mas chimeric promoter;And the application of SA in combination with MJ(1 mmol/LSA & 250 ?mol/L MJ)produced an additive effect that exceeded the wounding response.The results showed that the ocs/mas chimeric promoter is a strong inducible promoter that can be activated by various stresses.The chimeric promoter should have utility in development of disease and insect resistant transgenic crops.

Studies on cytogeography of Pinellia ternata poliploid complex / 中国中药杂志

<p><b>OBJECTIVE</b>In order to clarify the genetic background of Pinellia ternata germplasm resources in China, the chromosomal constitution and cytogeographical distribution of P. ternata were investigated in 27 different populations among 16 provinces and regions in China systematically.</p><p><b>METHOD</b>Cytological and cytogeographical methods were used in the study.</p><p><b>RESULT</b>P. ternata in China is a polyploid complex, which contains septuploid (2n = 7x = 91) , octoploid (2n = 8x = 104) , nonuploid (2n = 9x = 117) and decaploid (2n = 10x = 130). Meanwhile the aneuploid series (2n = 92, 103, 105, 115) of a minority of P. ternata were also found.</p><p><b>CONCLUSION</b>The genetic differentiation and the phenomenon of ploidy miscellany commonly exist in the species of P. ternata in China, both for natural populations and cultivated populations. Toxicity and chemical components of different ploidy P. ternata should be clarified before the superior multiploid is selected for normalized plantation of the plant.</p>