Negative modulation of NO for diaphragmatic contractile reduction induced by sepsis and restraint position.

In practice of forensic medicine, potential disease can be associated with fatal asphyxia in restraint position. Research has demonstrated that nitric oxide (NO) and nitric oxide synthase (NOS) are plentifully distributed in skeletal muscle, contributing to the regulation of contractile and relaxation. In the current study, respiratory functions, indices of diaphragmatic biomechanical functions ex vivo, as well as NO levels in serum, the expressions of diaphragmatic inducible NOS (iNOS) mRNA, and the effects of L-NNA on contractility of the diaphragm were observed in sepsis induced by cecal ligation and puncture (CLP) under the condition of restraint position. The results showed that in the CLP12-18h rats, respiratory dysfunctions; indices of diaphragmatic biomechanical functions (Pt, +dT/dt(max), -dT/dt(max), CT, Po, force over the full range of the force-frequency relationship and fatigue resistance) declined progressively; the NO level in serum, and iNOS mRNA expression in the diaphragm increased progressively; force increased significantly at all stimulation frequencies after L-NNA pre-incubation. Restraint position 1 h in CLP12 h rats resulted in severe respiratory dysfunctions after relative stable respiratory functions, almost all the indices of diaphragmatic biomechanical functions declined further, whereas little change took place in NO level in serum and diaphragmatic iNOS mRNA expression; and the effects of L-NNA were lack of statistical significance compared with those of CLP12 h, but differed from CLP18 h group. These results suggest that restraint position and sepsis act together in a synergistic manner to aggravate the great reduction of diaphragmatic contractility via, at least in part, the negative modulation of NO, which may contribute to the pathogenesis of positional asphyxia.

[Differentiation of human embryonic stem cells to endothelial cells via improved three-dimension approach].

OBJECTIVE: To establish an improved three-dimension (3D) and serum-free approach to differentiate human embryonic stem cells (hESCs) into endothelial cells, and detect the endothelial functions of the obtained cells. METHODS: We cultured undifferentiated H9 human embryonic stem cell line in low-adhesion dishes to form embryonic bodies (EBs). After 12 days, EBs were harvested, re-suspended into rat tail collagen type I, and put into the incubator (37℃). After 30 minutes, EGM-2 culture medium was added to the solidified collagen, and the EBs were cultured for another 3 days to form embryonic body-sproutings (EB-sproutings). EB-sproutings were digested with 0.25% collagenase I and 0.56 U/ml Liberase Blendzyme for 20 minutes respectively, and the CD31(+) cells were sorted by FACS. The endothelial functions were tested by Dil-ac-LDL uptake assay and tube formation assay. RESULTS: This approach raised the efficiency of endothelial differentiation to 18%, and also avoided the contamination with animal materials. The obtained hESC-derived endothelial cells (hESC-ECs) had the similar pattern of surface biomarkers as human umbilical vein endothelial cells (HUVECs), and their endothelial functions were confirmed by the uptake of Dil-ac-LDL and the tube formation on Matrigel. CONCLUSIONS: The improved 3D approach can enhance the efficiency of differentiation from hESCs into endothelial cells. Furthermore, serum free differentiation system may be applied in future hESC-based therapies for various ischemic diseases.

[Effects of restraint position on changes of diaphragmatic mechanical characteristic in rats].

OBJECTIVE: To observe effects of restraint position on the changes of diaphragmatic mechanical characteristic in rats, and try to explore the role of nitric oxide (NO). METHODS: Rat model of restraint position was established. Rats were divided into control group, restraint position 12h and 24h groups. The markers of respiratory functions in vivo and the biomechanical markers of diaphragmatic characteristic ex vivo were evaluated. Serum NO levels were measured with spectrophotometry. The expressions of nNOS and iNOS mRNA in diaphragm were detected using RT-PCR. RESULTS: Compared with control group, respiratory rate, tidal volume and minute ventilation were significantly decreased in the restraint position 12h and 24h groups. Pt of diaphragm significantly decreased and force-generating capacity reduced at low frequency stimulation in 12h group. Force-generating capacity over the full range reduced at low and high frequency stimulation in 24h group. Pt of diaphragm in control and restraint position groups increased after L-NNA pre-incubation. Force-frequency relationship after L-NNA pre-incubation reduced in 24h group. NO level in serum increased significantly in the restraint position groups. Diaphragmatic nNOS mRNA expression was upregulated significantly in the restraint position groups. CONCLUSION: Restraint position induces the decreasement of diaphragmatic contractility and the decreasement is mediated by NO from diaphragm or circulation blood.

[Pulse wave: the bridge connecting traditional Chinese medicine with Western medicine].

Pulse wave, a research focus in both traditional Chinese medicine and Western medicine, which contains a wealth of human physiological and pathological information, has always been the concern of medical practitioners. On the basis of the review on the development of the pulse wave theory and its applications, the existing problems in this field are discussed in this paper. On the basis of the status quo of pulse wave information extraction methods and the utilization of pulse wave in traditional Chinese and Western medicine, a more in-depth study on pulse wave is proposed to make it a bridge connecting traditional Chinese medicine with Western medicine.

Blocking beta 2-adrenergic receptor inhibits dendrite ramification in a mouse model of Alzheimer's disease.

Dendrite ramification affects synaptic strength and plays a crucial role in memory. Previous studies revealed a correlation between beta 2-adrenergic receptor dysfunction and Alzheimer's disease (AD), although the mechanism involved is still poorly understood. The current study investigated the potential effect of the selective ß2-adrenergic receptor antagonist, ICI 118551 (ICI), on Aß deposits and AD-related cognitive impairment. Morris water maze test results demonstrated that the performance of AD-transgenic (TG) mice treated with ICI (AD-TG/ICI) was significantly poorer compared with NaCl-treated AD-TG mice (AD-TG/NaCl), suggesting that ß2-adrenergic receptor blockage by ICI might reduce the learning and memory abilities of mice. Golgi staining and immunohistochemical staining revealed that blockage of the ß2-adrenergic receptor by ICI treatment decreased the number of dendritic branches, and ICI treatment in AD-TG mice decreased the expression of hippocampal synaptophysin and synapsin 1. Western blot assay results showed that the blockage of ß2-adrenergic receptor increased amyloid-ß accumulation by downregulating hippocampal α-secretase activity and increasing the phosphorylation of amyloid precursor protein. These findings suggest that blocking the ß2-adrenergic receptor inhibits dendrite ramification of hippocampal neurons in a mouse model of AD.

Expression of paxillin and FAK mRNA and the related clinical significance in esophageal carcinoma.

The objective of the present study was to investigate the expression of paxillin and focal adhesion kinase (FAK) mRNA in esophageal carcinoma tissues, and their relationship with clinicopathological parameters, as well as to analyze the correlation of paxillin and FAK mRNA levels in esophageal carcinoma. By using reverse transcription polymerase chain reaction (RT-PCR), the mRNA expression levels of paxillin and FAK were detected in 121 samples of esophageal carcinoma, 43 samples of atypical hyperplasia and 56 samples of normal esophageal mucosa. The results showed that the positive rates of paxillin and FAK mRNA expression in esophageal carcinoma were 87.6 and 80.17%, respectively, which were significantly higher (P<0.05) than those in atypical hyperplasia (44.19 and 39.53%) and normal esophageal mucosa (5.36 and 12.5%). Notably, paxillin and FAK mRNA expression levels were significantly correlated with the differentiation degree and depth of invasion of esophageal carcinoma and with lymph node metastasis (P<0.05). In addition, paxillin and FAK mRNA expression levels in esophageal carcinoma were positively correlated (r=0.4804, P=0.000). In conclusion, the combined detection of paxillin and FAK mRNA expression is expected to provide a theoretical basis for the molecular diagnosis of esophageal carcinoma.