家兔急性实验性面神经损伤的组织病理观察

目的　观察家兔面神经急性损伤后髓鞘和轴索的组织病理变化。方法　用丝线结扎茎乳孔以外的面神经总干 ,观察结扎后 1天、3天及 5天面神经的组织病理改变。结果　家兔面神经受损后 ,先后在髓鞘和轴索出现轻重不等、程度不同的形态学改变。结论　结扎家兔面神经后 ,其髓鞘及轴索会出现相应的病理改变 ,且随着结扎天数的增加 ,面神经损伤亦呈加重的趋势     

Risk factors of uterine contraction after ureteroscopy in pregnant women with renal colic

International Urology and Nephrology - Ureteroscopy is widely applied in pregnant women with renal colic, but such patients are easy to experience uterine contraction after surgery. There are many...     

Protective effect of pinocembrin from Penthorum chinense Pursh on hepatic ischemia reperfusion injury via regulating HMGB1/TLR4 signal pathway

Hepatic ischemia–reperfusion injury (HIRI) is of common occurrence during liver surgery and transplantation. Pinocembrin (PIN) is a kind of flavonoid monomer extracted from the local traditional Chinese medicine Penthorum chinense Pursh (P. chinense). However, the effect of PIN on HIRI has not determined. We investigated the protective effect and potential mechanism of PIN against HIRI. Model mice were subjected to partial liver ischemia for 60 min, experimental mice were pretreated with PIN orally for 7 days, and H₂O₂-induced oxidative damage model in AML12 hepatic cells was established in vitro. Histopathologic analysis and serum biochemical levels revealed that PIN had hepatoprotective activities against HIRI. The variation of GSH, SOD, MDA, and ROS levels indicated that PIN treatments attenuated oxidative stress in tissue. PIN pretreatment obviously ameliorated apoptosis, and restrained the expression of HMGB1 and TLR4 in vivo. In vitro, compared with H₂O₂ group, the contents of ROS, mitochondrial membrane potential, apoptotic cells, and Bcl-2 protein were decreased, while the Bax protein expression was increased. Moreover, HMGB-1 small interfering RNA test and western blotting showed that PIN pretreatment reduced HMGB1 and TLR4 protein levels. In conclusion, PIN pretreatment effectively protected hepatocytes from HIRI and inhibited the HMGB1/TLR4 signaling pathway.     

A head-to-head comparison of measurement properties of the EQ-5D-3L and EQ-5D-5L in acute myeloid leukemia patients

Quality of Life Research - This study aimed to compare the measurement properties of EQ-5D-3L(3L) and EQ-5D-5L(5L) in patients with acute myeloid leukemia (AML) in China. We consecutively recruited...     

Post-translational modification of proteins by arginine and lysine following crush injury and during regeneration of rat sciatic nerves

Following crush injury to rat sciatic nerves, a crude fraction of the 150,000 g supernatant can post-translationally incorporate [3H]Arg and [3H]Lys into endogenous proteins in amounts approximately 10 times uninjured control nerves. These increases occur in the proximal nerve stump within 2 h of injury and 2 weeks later in a distal segment of nerve containing the tips of the regenerating axons. In the present experiments, the endogenous nerve proteins modified by Arg or Lys in these nerve segments have been identified using two-dimensional polyacrylamide gel electrophoresis. The fraction used to assay for protein modification, the void volume of a Sephacryl S-300 column, was found to contain only a few proteins visible by Coomassie blue staining, one of which is likely to be albumin (68 kDa, pI 6.4). While this protein was modified by both Arg and Lys, the majority of label was found in areas not showing Coomassie blue staining. This indicates that of the many potential targets of post-translational arginylation and lysylation, most are proteins of relatively low abundance. A variety of proteins were modified by Arg or Lys alone while others were modified by both Arg and Lys. A high molecular weight protein (175 kDa, pI 9.0) was modified only by Lys and only at 2 h post crush. Of a variety of modified proteins of approximately 17 kDa one (pI 6.3) was modified by both Arg and Lys and at both time points, while another (pI 9.0) was modified at both time points, but only by Lys. The results show that Arg and Lys can be added post-translationally to a large number of low abundance, soluble sciatic nerve proteins, and that some of those proteins are modified only by Arg or Lys while others are modified by both Arg and Lys. Also, the modification of certain proteins appears to be associated specifically with the immediate response of a nerve to injury (e.g. 88 kDa, pI 7.1) while others are associated with the regenerative period (e.g. 56 kDa, pI 7.4).     

Posttranslational modification of nerve proteins by amino acids

Both axonal and glial components of nerve are capable of carrying out reactions in which Arg, Lys, Leu, Pro, Val, AJa and Ser can be covalently linked to endogenous proteins in reactions which require tRNA but occur in the absence of ribosomes and ribosomal RNA. These posttranslational protein modifications appear to play important roles in nerve regeneration since they are increased more than 10-fold within 2 h of a crush injury in nerves which are capable of regeneration, but are not activated in nerves not capable of regrowth following injury. The regulation of the modification of proteins by Arg and Lys in vivo appears to be the function of separate peptides. The exogenous application of serine protease inhibitors (but not other protease inhibitors) mimics the effect of the endogenous peptides, suggesting that the endogenous regulators have serine protease inhibitory activity. The targets for modification are proteins of low abundance and thus far have been identified only in terms of their molecular weights and isoelectric points. The site of addition of Arg, but not the other amino acids, to target proteins is to the amino terminus. The addition of Arg to an amino terminus is likely to be involved in the ubiquitin mediated proteolysis of the modified protein. One of the most unusual findings in these series of experiments is that in regenerating sciatic nerves, amino acid modified proteins aggregate to form complexes of greater than 2 × 106 Da. The significance of this finding is not known. But we speculate that the aggregate may result from the assembly of an insoluble functional unit of the cell from soluble precursor proteins, and that the trigger for their assembly is amino acid modification.