Hyperbaric oxygen preconditioning inhibits skin flap apoptosis in a rat ischemia-reperfusion model.

BACKGROUND: Hyperbaric oxygen (HBO) improves skin flap function and inhibits partial necrosis induced by ischemia-reperfusion (I/R) injury. Our study aimed to evaluate the mechanism underlying HBO regulation of the antiapoptosis factors associated with I/R injury of skin flaps. METHODS: The rats were divided into sham surgery, I/R, and HBO groups. Rats from the HBO group received HBO preconditioning followed by I/R surgery. Blood perfusion of the skin flaps was measured with laser Doppler flowmeters. Tissue morphology and apoptosis were subsequently assessed based on hematoxylin-eosinhe and terminal deoxynucleotidyl transferase dUTP nick-end labeling staining. Protein expression of phosphorylated apoptosis signal-regulating kinase 1 (pASK-1), phosphorylated c-Jun N-terminal kinase (pJNK), B-cell lymphoma-2 (Bcl-2), and Bcl2-associated X protein (Bax) was examined by immunodetection, and Bcl-2 messenger RNA expression was detected by quantitative polymerase chain reaction. In addition, caspase-3 activity was also measured. RESULTS: The result of microcirculation analysis showed that the survival and blood perfusion rates significantly increased in the skin flap after HBO exposure. Terminal deoxynucleotidyl transferase dUTP nick-end labeling staining revealed that cell apoptosis was significantly attenuated in the HBO group. Furthermore, HBO preconditioning increased the expression of Bcl-2 and inhibited pASK-1, pJNK, and Bax expression as determined by both immunohistochemistry and Western blot. Caspase-3 activity and the Bax/Bcl-2 ratio declined in the HBO group. CONCLUSIONS: HBO preconditioning effectively ameliorates I/R injury by regulating the apoptosis signal-regulating kinase 1 and/or c-Jun N-terminal kinase pathway and anti- and proapoptosis factors.

Effects of hyperbaric oxygen preconditioning on ischemia-reperfusion inflammation and skin flap survival.

BACKGROUND: Hyperbaric oxygen preconditioning (HBO) is a new method of ischemia preconditioning. In this study, we examined its effects on skin flap survival and the mechanisms involved. METHODS: Thirty-six rats were divided into three groups: HBO preconditioning, control, and sham groups. An extended epigastric adipocutaneous flap based on the right superficial epigastric artery and vein was raised. A 3-hour period of flap ischemia was induced by clamping the pedicle vessels with a microvascular clamp. At the end of ischemia induction, the clamp was removed and the flap was resutured. Rats in the HBO preconditioning group were treated with HBO four times before surgery. Microcirculation in the skin flap was measured on postoperative days 1, 3 and 5. The size of the flap was measured on postoperative day 5, before the animals were sacrificed. Samples of the skin flap were prepared and stained with hematoxylin and eosin. The levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, and IL-6 in the flap samples were measured. RESULTS: Surviving flap size was significantly higher in the HBO preconditioning group compared with controls, with a reduced inflammatory response and increased perfusion. IL-1, TNF-α, and IL-6 levels in the HBO preconditioning group were lower than in controls. CONCLUSIONS: HBO preconditioning improved flap survival in this ischemia-reperfusion rat model. The mechanisms responsible for this effect may relate to attenuation of the inflammatory response and increased flap perfusion following HBO preconditioning.

[Impact of S100P expression on clinical outcomes of gastric cancer patients with adjuvant chemotherapy of oxaliplatin and its mechanisms].

OBJECTIVE: To investigate the impact of the expression of S100P on the prognosis and tumor chemosensitivity in patients with resectable gastric cancer and its mechanisms. METHODS: The expression of S100P was analyzed in 121 resected primary gastric cancer tissues by using tissue array of immunohistochemistry excised from January 2003 to December 2007. The patients received adjuvant chemotherapy with oxaliplatin. The pEGFP-S100P plasmid was constructed and was transfected into BGC823 cell line to establish gastric cancer cell line with over-expression of human S100P, BGC823-S100P. The expression level of S100P was determined by real-time PCR and Western blot assay. The chemosensitivity of BGC823-S100P cell line to oxaliplatin was detected by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) assay. RESULTS: The S100P was positively expressed in 64 tumors (52.9%, 64/121). Although there was no significant relation between the expression of S100P and tumor T staging (P = 0.683), N staging (P = 0.472), M staging (P = 0.770) and differentiation (P = 0.553), Wilcoxon test showed that the 5-year cumulative survival rate of patients with positive S100P expression was significantly higher than that of patients with negative expression (20.3% vs. 3.5%, P = 0.034). Furthermore, overexpressed of S100P was found in the BGC823 cell line, BGC823-S100P. The mRNA and protein level of S100P in pEGFP transfected BGC823-S100P cell lines were significantly higher than those in control group (8.42 ± 1.38 vs. 0.83 ± 0.11 and 3.52 ± 0.48 vs. 0.97 ± 0.19, all P < 0.05). It indicated with MTT assay that the half-inhibitory concentration (IC(50)) to oxaliplatin decreased in BGC823-S100P cells, and was significantly lower than that in vector-only transfected cells [(142 ± 16) mg/L vs. (266 ± 11) mg/L, P = 0.032]. CONCLUSIONS: S100P may also be a potentially novel independent prognostic factor in gastric cancer patients following curative resection. And it could improve the cumulative survival of the patients through enhancing the chemosensitivity of tumor cell line to oxaliplatin.

Simultaneous determination of flavonoids in Ixeridium gracile by micellar electrokinetic chromatography.

A micellar electrokinetic chromatography (MEKC) method has been developed for the quantitative analysis of five flavonoids: luteolin 7-O-glucoside (LG), 2',4'-dihydroxy-dihydrochalcone (DD), 2',4'-dihydroxy-chalcone (DC), 7-hydroxy-flavanone (HF) and quercetin 3-O-galactoside (QG) in Ixeridium gracile with UV detection at 275 nm. The applied voltage was 25 kV and the capillary temperature was kept constant at 25 degrees C. The effects of buffer pH, the concentration of electrolyte and organic modifier on migration behavior were studied. Optimum separation condition was achieved with 15 mM borate, 30 mM sodium dodecyl sulfate (SDS) and 10% (v/v) ethanol at pH 10.5. Regression equations showed good linear relationships (correlation coefficients: 0.9984, 0.9991, 0.9994, 0.9995 and 0.9997) between the peak area of each compound and their concentrations. The relative standard deviations (R.S.D.) of the migration time and peak area were less 1.67 and 3.53% (intra-day), and 1.82 and 3.73% (inter-day), respectively, under the optimum separation conditions. The contents of the five active compounds in I. gracile were determined with satisfactory repeatability and recovery.

Phenolic derivatives with free-radical-scavenging activities from Ixeridium gracile (DC.) Shih.

Phytochemical investigation of the Tibetan medicinal plant Ixeridium gracile resulted in the isolation and identification of twelve flavonoids and two coumarins, compounds 1-14, the dimeric '2alpha,3alpha-epoxy-5,7,3',4'-tetrahydroxyflavan-(4beta-->8)-epicatechin' (1) being a new constituent. The free-radical-scavenging potentials of different extract fractions as well as of the pure compounds towards the DPPH (1,1-diphenyl-2-picrylhydrazyl) radical were evaluated, and are discussed in terms of structure-activity relationship (SAR). The flavonoids were found to be the major constituents contributing to the free-radical-scavenging activity of I. gracile, but the high concentration of coumarins additionally contributed to the observed activity.

[Study on chemical constiuents from Ligularia intermedia of shanxi].

OBJECTIVE: To study the chemical constituents of Ligularia intermedia of Shanxi. METHOD: The compounds were isolated by column chromatography on silica gel and preparative TLC. The structures were identified by IR, MS, 1D/2DNMR spectral data and X-ray single crystal diffraction and other methods1. RESULT: Nine compound were isolated and identified as 8beta-hydroxyeremophil-7(11)-ene-12, 8alpha(4beta, 6alpha)-diolide (1), 8beta-methoxyeremophil-7(11)-ene-12, 8alpha(4beta, 6alpha)-diolide (2), petasin (3), isopetasin (4), liguhodgsonal (5), ligudentatol (6), ligujapone (7), lupeol (8) and lupeol palmitate (9). CONCLUSION: Compounds 2, 3, 4, 6, 7 and 9 were isolated from the plant for the first time.

[Effects of electroacupuncture treatment on nitrergic neurotransmitter in bladder neck and detrusor of rats with unstable bladder].

OBJECTIVE: To observe the effects of electroacupuncture treatment on nitrergic neurotransmitter in bladder neck and detrusor of rats with unstable bladder. METHODS: Rat models of unstable bladder were established by operation to induce urethral obstruction. Electroacupuncture treatment was given by acupuncturing Huiyang and Zhonglushu points for a week. Then the neuronal nitric oxide synthase (nNOS)-, endothelial nitric oxide synthase (eNOS)- and inducible nitric oxide synthase (iNOS)-positive cells in bladder neck and detrusor of the rats were observed. RESULTS: The nitrergic neurotransmitter in bladder neck and detrusor were obviously decreased in rats with unstable bladder. The electroacupuncture treatment could significantly increase the contains of NOS in bladder tissue. CONCLUSION: To promote the synthesis and secretion of nitrergic neurotransmitter in bladder tissue may be one of the mechanisms of acupuncture in adjusting bladder function.

Two new polyporusterones from Polyorus umbellatus.

Two new polyporusterones named as porusterone I and polyprosterone II were isolated from polyourus umbellatus. Their structures have been established on the basis of spectroscopic analysis.