Clinical nurses' nasogastric feeding practices in adults: a multicenter cross-sectional survey in China.

OBJECTIVE: We aimed to investigate practices of nasogastric tube (NGT) intubation and feeding for adults by clinical nurses in China. METHODS: A self-designed and validated questionnaire comprising 30 questions was distributed to 560 clinical nurses in three comprehensive hospitals of Xiamen, China. The questionnaire covered participants' demographic characteristics, NGT placement, administration of enteral nutrition (EN), and monitoring or management of feeding intolerance. RESULTS: A total 464 (82.9%) questionnaires were completed; 36.2% of nurses used nose-ear-xiphoid and 79.5% forehead-xiphoid measurement to define the internal length of the NGT. Many participants still used traditional methods to confirm NGT placement (auscultation of injected air 50.2%, bubble test 34.7% and observing feeding tube aspirate 34.3%). Bolus feeding was the most commonly used technique to administer EN. A total 97.0% of all nurses used syringes to measure gastric residual volume (GRV), and 62.7% measured GRV every 4-8 hours. The most frequently used GRV threshold values were 200 mL (44.6%) and 150 mL (25.2%). Most nurses stopped feeding immediately when encountering high GRV (84.3%) or diarrhea (45.0%). The nasogastric feeding practices of many clinical nurses were not consistent with international guidelines. CONCLUSIONS: Our study can provide an impetus for nursing administrators to revise their nasogastric feeding procedures, to promote compliance with evidence-based guidelines.

Effects of TGF-ß1 and alginate on the differentiation of rabbit bone marrow-derived mesenchymal stem cells into a chondrocyte cell lineage.

The aim of the present study was to investigate the effect of a three-dimensional (3D) culture system of sodium alginate gel on the directional differentiation induction of bone marrow-derived mesenchymal stem cells (BMSCs) into chondrocytes, as well as the in vitro gene transfection technique. The biological characteristics of the passage and proliferation of rabbit BMSCs were investigated under conditions of in vitro monolayer and 3D culture of sodium alginate gel. Transforming growth factor (TGF)-ß1 gene recombinant adenoviral cosmid vectors and the recombinant adenoviral vector Ad.TGF-ß1 were constructed, and the effect of Ad.TGF-ß1 transfection on the differentiation of BMSCs into chondrocytes was investigated. The whole bone marrow rinsing method was used to obtain, separate and purify the rabbit BMSCs, and the in vitro monolayer and 3D culture of sodium alginate gel were thus successfully and stably established. A safe, stable and efficient method of constructing Ad.TGF-ß1 TGF-ß1 gene recombinant adenoviral vectors was established. Following TGF-ß1 transfection, BMSCs were able to continuously secrete significantly increased amounts of specific extracellular matrix components of chondrocytes, such as collagen II and proteoglycans. Furthermore, the effects in the post-gene transfection 3D culture group were found to be enhanced compared with those in the monolayer culture group. In conclusion, the 3D culture system of sodium alginate gel and in vitro gene transfection exhibited significant inductive effects on differentiation, which could be used to promote BMSCs to differentiate into chondrocytes.

Defective histone H3K27 trimethylation modification in embryos derived from heated mouse sperm.

The mouse sperm genome is resistant to in vitro heat treatment, and embryos derived from heated sperm can support full-term embryonic development, but the blastocyst rate and implantation rate are lower compared to embryos derived from fresh sperm. In the present study, the patterns of DNA methylation, histone H4K12 (ACH4K12) acetylation, H3K9 trimethylation (H3K9-TriM), and H3K27 trimethylation (H3K27-TriM) in preimplantation embryos derived from 65 °C-heated sperm were investigated. Although no evident changes in global DNA methylation, histone H4K12 (ACH4K12) acetylation, and H3K9 trimethylation (H3K9-TriM) were found, significantly lower levels of H3K27-TriM, which was thought to be one of the reasons for low efficiency of mouse cloning, were found in the inner cell mass of heated-sperm derived blastocysts. Thus, defective modification of H3K27-TriM might contribute to compromised development of embryos derived from heated sperm.

Cannabinoid-2 receptor activation protects against infarct and ischemia-reperfusion heart injury.

Endocannabinoid system is reported to be activated during myocardial ischemia-reperfusion (IR) injury and protects against heart injury. We, therefore, observed changes in endocannabinoids levels during acute myocardial infarction (AMI) and myocardial IR injury and evaluated the role of cannabinoid-2 (CB2) receptor in infarct and IR heart injury. In contrast to 16 control patients with normal coronary artery angiogram, the endocannabinoid 2-arachidonoylglycerol level in the infarct-side coronary artery of 23 AMI patients increased significantly, with increased reactive oxygen species and tumor necrosis factor-α levels in both infarct-side coronary artery and radial artery. Then, 35 C57BL/6J mice were made into SHAM, AMI, or IR models. AMI and IR groups were treated with CB2-selective agonist HU308 ((+)-(1aH,3H,5aH)-4-[2,6-dimethoxy-4-(1,1-dimethylheptyl)phenyl]-6,6-dimethylbicyclo[3.1.1]hept-2-ene-2-carbinol), with or without CB2-selective antagonist AM630 [6-iodo-2-methyl-1-[2-(4-morpholinyl)ethyl]-1H-indol-3-yl](4-methoxyphenyl)methanone through intraperitoneal injection. Compared with the SHAM, expressions of cannabinoid CB1/CB2 receptor proteins in AMI/IR animals were upregulated; production of 2-arachidonoylglycerol and anandamide and release of reactive oxygen species and tumor necrosis factor-α also increased. HU308 significantly decreased the infarct size and the levels of reactive oxygen species and tumor necrosis factor-α in AMI/IR animals. However, these effects were blocked by AM630. In conclusion, the endocannabinoid system was activated during AMI and IR, and CB2 receptor activation produces a protective role, thus offering a novel pharmaceutical target for treating these diseases.

[Immunocharacteristics of bone marrow mesenchymal stem cell].

OBJECTIVE: To study the immunocharacteristics of bone marrow mesenchymal stem cell (MSC) and provide experimental evidence for the potential therapeutic application. METHODS: MSCs were isolated from rat bone marrow and confirmed by immunophenotype, and the growth dynamic and cell cycle were analyzed. MSCs were cultured with or without 200 U/ml interferon gamma (IFNg) , the expression of PDL-1, CD54, CD40, CD80, CD86, MHC-I, and MHC-II was detected by flow cytometry. MSCs were used as regulatory cells in mixed lymphocyte reaction (MLR), the PDL-1 and CD54 molecules on MSCs were blocked to explore their roles in MLR. The IFN, IL-2, IL-4 and IL-10 molecules in culture supernatant were quantified by ELISA. The homing of MSCs to liver and induction of microchimerism were analyzed after MSCs transplantation. RESULTS: The purity of MSCs was high. The growth curve showed that the first two days were the lag phase; the third, fourth, fifth days were the log phase; the sixth and seventh days were the stationary phase. Flow cytometry indicated that 76.0%+/-2.0% of the MSCs were in G1/G0 phase, 13.0%+/-2.0% in S phase, 10.0%+/-1.7% in G2 and M phase. IFNg treatment led to up-regulation of CD54, PDL-1, MHC-I and MHC-II, however, CD40, CD80 and CD86 were not expressed on MSCs even after IFNg treatment. MSCs inhibited MLR, IFNg treatment enhanced the inhibitory effect of MSCs on MLR. Blocking of PDL-1 or CD54 on MSCs partially alleviated the inhibition effect. There were high levels of IFNg and IL-10, and low level of IL-4 in the culture supernatant of MLR, however, IL-2 was not detected. MSCs can home to the liver and induce formation of microchimerism after transplantation. CONCLUSION: IFNg treatment enhances the inhibitory effect of MSCs on MLR, PDL-1 and CD54 are key molecules mediating this inhibitory effect. MSC can home to the liver and induce formation of microchimerism after transplantation.