The degradation kinetics of chlorogenic acid (5-CQA), cryptochlorogenic acid (4-CQA), and neochlorogenic acid (3-CQA) in aqueous solution at 37 degrees C and different pH values (7.05, 7.96, 9.25) were investigated in the present work. The results indicated that 3-, 4- and 5-CQA tended to remain stable in acidic pH circumstance, and unstable in neutral and alkaline pH circumstance. With the increase of the alkalinity, the degradation of 3-, 4- and 5-CQA was increased leading to a less amount of total CQA and was satisfactorily described by the Weibull equation. Meanwhile, caffeic acid was not detected after the degradation of CQA. Moreover, the degradation of 3-CQA and 5-CQA tended to be converted to 4-CQA, and the degradation of 4-CQA tended to be converted to 3-CQA rather than 5-CQA. The comparison of the degradation kinetics parameters of 3-, 4- and 5-CQA at neutral and alkaline pH values showed that the orders of the rate constant (k) values were 4-CQA > 3-CQA > 5-CQA, while the orders of the degradation half life (t½) values were 4-CQA < 3-CQA < 5-CQA, indicating the orders of the stabilities of 3-, 4- and 5-CQA at 37 degrees C and neutral and alkaline pH values were 4-CQA < 3-CQA < 5-CQA.

BACKGROUND:Although the mechanism why neuronal cels wil die after transient cerebral ischemia has not been completely elucidated, many researches nowadays have investigated the pathological mechanism in the level of celular organs, such as mitochondria.
OBJECTIVE:To summarize and discuss the functions of neuronal mitochondria and apoptosis signaling pathways in transient cerebral ischemia.
METHODS: A computer-based online retrieval was performed to search papers in CNKI and PubMed databases using the key words of “cerebral ischemia, mitochondrion, apoptosis, reactive oxygen species, reperfusion, superoxide dismutase, nitric oxide synthase, Bcl-2 protein family, review” in Chinese and English, respectively. Papers published recently or in the prestigious journals were selected in the same field. After excluding objective-independent papers and repeated studies, 50 papers were included for further analysis.
RESULTS AND CONCLUSION:Recently mitochondria are found to play an important role after transient cerebral ischemia by producing a lot of reactive oxygen species to activate many kinds of signaling pathways and regulate mitochondria-mediated apoptosis. Reactive oxygen cannot only induce biomacromolecule injury but also induce apoptosis signal transduction. Deeply investigation is needed on the pathological mechanism after transient cerebral ischemia.

Objective To investigate the role of A2B adenosine receptor(A2BAR)in 6% HES 130/0.4-induced reduction of pulmonary capillary permeability in a rat model of sepsis.Methods Fifty male SD rats weighing 250-300 g were randomly divided into 5 groups(n = 10 each): group Ⅰ sham operation(group S);group Ⅱ sepsis(group CLP);group Ⅲ ,Ⅳ,Ⅴ low,medium,high dose HES(group H1,2,3).The animals were anesthetized with intraperitoneal pentobarbital sodium 50 mg/kg.Left carotid artery and left femoral vein were cannulated for MAP and HR monitoring and fluid and drug administration.Sepsis was induced by cecal ligation and puncture (CLP).6% HES 130/0.4 7.5,15.0 and 30.0 ml/kg were infused iv over 2 h in group H1,2,3 respectively at 4 h after CLP.The animals were sacrificed at 6 h after CLP.The lungs were isolated for determination of pulmonary capillary permeability(by iv Evans blue injection),the expression of A2BAR and the contents of cAMP,protein kinase A(PKA),TNF-α,IL-6 and IL-10 in the lung tissue.Results CLP significantly increased pulmonary capillary permeability,A2BAR expression and cAMP,IL-6 and TNF-α contents in the lung tissue in group Ⅱ as compared with group S.0.6% HES 130/0.4 significantly reduced pulmonary capillary permeability,increased A2BAR expression,cAMP,PKA and IL-10 and decreased IL-6 and TNF-αcontents in the lung tissue in group H1,2,3 as compared with group CLP.6% HES 130/0.4 decreased pulmonary capillary permeability and up-regulated A2BAR expression in a dose-dependent manner.6% HES 130/0.4 15.0 ml/kg was most effective in increasing cAMP and PKA contents in the lung and depressing inflammatory response.Conclusion 6% HES 130/0.4 decreases pulmonary capillary permeability in a rat model of sepsis by up-regulating A2BAR expression in lung tissue.

This article was aimed to study the effect of polyphenols fromRubus suavissirnusS. Lee (RSLP) on spontaneous hypertensive rats (SHR) and to explore its mechanism of anti-hypertensive. The water extraction of RSLP was prepared. And the polyphenols was extracted with macroporous resin. The non-invasive blood pressure analysis system was used to detect the blood pressure. SHR model was selected to study the anti-hypertensive effect. The 16 normal Wistar rats were randomly divided into the control group and the normal RSLP high-dose group (RSLP-NH). The 40 SHR were randomly divided into the model group, Captopril group, RSLP-L group, RSLP-M group and RSLP-H group. SBP, DBP, HR, body weight and organ index were observed after the drug administration for 8 weeks and drug withdrawal for 2 weeks. The contents of SOD, MDA, GSH-Px, NO, NOS and ANP in serum were measured. The results showed that the blood pressure of SHR was significantly higher than that of the control group, which can be used for anti-hypertensive studies. Each RSLP group can obviously reduce the SBP and DBP of SHR (P < 0.05), but it had no effect on HR (P > 0.05). RSLP can elevate GSH-Px, SOD levels and reduce the activity of MDA (P < 0.05). RSLP can reduce NO, NOS and ANP contents in serum (P < 0.05). It was concluded that RSLP can significantly reduce the SBP and DBP of SHR, but it had no significant effect on HR. It can increase the activity of GSH-Px, SOD, NO, NOS levels, and reduce the contents of MDA, ANP in serum. It had certain inhibitory effect on the left ventricular hypertrophy.

Real-time fluorescent quantitative PCR was used to examine PGC-1α mRNA expression in brown adipose tissue and skeletal muscle of rats. The results showed that the expression levels of PGC-1α mRNA in brown adipose tissue and skeletal muscle of obese rats were lower than those of the normal ones (all P<0.01). After high dose glucocorticoid treatment, the levels of PGC-1α mRNA expression in brown adipose tissue and skeletal muscle, both in normal and obese rats, were decreased significantly.

Objective To investigate the changes in high voltage-activated (HVA) calcium current in dorsal root ganglion (DRG) neurons isolated from rats with neuropathic pain. Methods Pathogen-free male SD rats aged 4-6 weeks weighing 180-220 g were used in this study. The animals were anesthetized with intraperitoneal pentobarbital sodium 50 mg/kg. Neuropathic pain was induced by ligation of L5 spinal nerve between DRG and sciatic nerve. The nerve was transected distal to the ligature. The animals which showed positive signs of neuropathic pain were decapitated on the 14th postoperative day. L5 and L4 DRGs were isolated and the neurons in the ganglia were enzymatically dissociated (group L5 and L4). The control group received no surgery (group C). The HVA Ca2+ current was recorded using whole-cell patch clamp technique. Results Peak calcium current density was significantly lower in group L5 and L4 than in group C, and was significantly lower in group L5 than in group L4 . Halfactivation value (Va 1/2) was also significantly lower in group L5 than in group C and L4 (P ＜ 0.05). The relative contribution of N-type to the total HVA Ca2+ current was significantly greater in group L5 than in group C and L4(P ＜ 0.05). There was no significant difference in the steady-state inactivation curves among the 3 groups. Conclusion In rats with neuropathic pain, the HVA Ca2+ current in the injured DRG neurons may play a key role in the induction of neuropathic pain.

Objective To evaluate the effect of hydrogen sulfide combined with mild hypothermia on cerebral ischemia-reperfusion (I/R) injury in rats. Methods Eighty male SD rats, aged 3 months, weighing 250-300 g, were randomly divided into 5 groups ( n = 16 each): sham operation group (group S), cerebral I/R group,mild hypothermia group (group M), sodium hydrosulfide group (group NaHS) and NaHS + mild hypothermia group (group NM). In group I/R, M, NaHS and NM, cerebral I/R was induced by occlusion of 4 vessels (cauterization of bilateral vertebral arteries and 15 min occlusion of bilateral common carotid arteries) followed by reperfusion. In group NaHS and NM, intraperitoneal NaHS 14 μmol/kg was injected immediately after reperfusion, while the equal volume of normal saline was injected in the other three groups. At the same time, the rectal temperature was reduced to 32-33 ℃ within 15 min, lasting for 6 h, in group M and NM, while it was maintained at 36-37 ℃by physical method in other groups. Twelve rats of each group were sacrificed after 6 h of reperfusion, and then the hippocampus was removed for determination of the content of H2 S by using spectrophotometer and the expression of p-CREB and BDNF mRNA by using Western blot and RT-PCR respectively. Four rats in each group were sacririced after 72 h of reperfusion and then the hippocampus was removed for microscopic examination. Results The cerebral I/R injury was attenuated in group M, NaHS and NM compared with group I/R, with the slightest injury in group NM. The H2S content was significantly higher in group I/R, M, NaHS and NM than in group S, and in group NaHS and NM than in group I/R and M. The expression of p-CREB and BNDF mRNA was significantly higher in group I/R, M, NaHS and NM than in group S, and in group M, NaHS and NM than in group I/R. The BDNF mRNA expression was significantly higher in group NM than in group M and NaHS. There was no significant difference in the H2S content and the expression of p-CREB and BNDF mRNA between group NaHS and M.Conclusion Hydrogen sulfide combined with mild hypothermia can attenuate cerebral I/R injury by up-regulating the expression of p-CREB and BDNF mRNA in hippocampus in rats.

Objective To measure the expression of protein kinase D1 (PKD1),tyr463-phosphorylaed PKD1 (pPKD1-tyr463) and ser916-phos-phorylaed PKD1 (pPKD1-ser916) in squamous cell carcinoma (SCC),Bowen's disease (BD) and actinic keratosis (AK),and to explore their significance.Methods Fresh tissue samples were resected from lesions of patients with SCC (SCC group),BD (BD group) and AK (AK group),as well as from normal skin of healthy human controls (control group),and each group had a sample size of 10.Real-time RT-PCR was performed to measure the mRNA expression of protein kinase D1 gene (PRKD1),and Western blot analysis to determine the protein expression of PKD1,pPKD1-tyr463 and pPKD1-ser916.In addition,immunohistochemical study was conducted to determine the expression of PKD1,pPKD1-tyr463 and pPKD1-ser916 in another 50 paraffin-embedded skin samples of SCC,20 samples of BD,20 samples of AK and 10 normal skin samples.Results PRKD1 mRNA expression significantly differed among the control group (0.64 ± 0.09),SCC group (5.37 ± 1.06),BD group (2.69 ± 0.72) and AK group (2.43 ± 0.46) (F =21.37,P ＜ 0.05),and was significantly higher in the SCC,BD and AK groups than that in the control group (P ＜ 0.05),as well as in the SCC group than that in the AK and BD groups (both P ＜ 0.05).However,no significant difference in the PRKD1 mRNA expression was observed between the BD group and AK group (P ＞ 0.05).Immunohistochemical study showed that the total PKD1 protein and pPKD1-tyr463 in the SCC and BD groups were mainly expressed in the cytoplasm and cell membrane of spinous layer cells and atypical cells,and their expression rates were significantly higher than those in the AK group and control group (all P ＜ 0.01).The pPKD1-ser916 was only slightly expressed in some cancer nests of well-differentiated SCC tissues,but not in poorly-differentiated SCC,AK,BD tissues and normal skin tissues.In the SCC group,the expression rate of PKD1 increased with the increase of the pathological grade of SCC,and the PKD1 expression was positively correlated with pPKD1-tyr463 expression (rcc =0.479,P ＜ 0.05).Western blot results were consistent with immunohistochemical findings.Conclusion PKD1 and pPKD1-tyr463 may be involved in the development and differentiation of skin tumors derived from stratified squamous epithelium,and PKD1 may exert promotive effects on the formation of cutaneous SCC by activating the Tyr463 phosphorylation site.

The ability of clinical teachers plays a key role in residents standardized training. The teachers should fully understand the relevant policies and improve the awareness of resident standardized training. The construction of clinical teaching ability is the essential ability for clinical teachers and is the focus of the teacher training, which can guarantee to guide the improvement of residents' clinical thinking ability and the training of their clinical skills. Establishing teacher training system, making a suitable train-ing plan, selecting applicable training content and participating in various types of teacher training should effectively improve the comprehensive teaching ability of clinical teachers for resident standardized training.

Objective Research has indicated that hydrogen sulfide(H2S) can regulate the function of N-methyl-D-aspartate re-ceptors(NMDARs) in the brain, but its effect on brain resuscitation requires further investigation.The study was to speculate the effect of H2 S on brain resuscitation as well as the underlying mechanism of neuroresuscitation by investigating the effects of hydrogen sulfide and hypo-thermia on the expression of NR2A, NR2B and phospho-cAMP response element binding protein (p-CREB) of NMDARs in the hippocampus after global cerebral ischemia following by reperfusion. Methods 100 male SD rats were randomly divided into five groups(n=20):sham operation group, model group, mild hypothermia group, NaHS group, NaHS combined mild hypothermia group.Pulsinelli-Brierley four-ves-sel occlusion method was induced to build the injury rat model by reperfusion after global cerebral ischemia .After 15 minutes'ischemia, im-mediate injection of 14μmol/kg NaHS was performed intraperitoneally on NaHS group and NaHS combined mild hypothermia group , while skin cooling(rectal temperature=32-33℃) was done on mild hypothermia group and NaHS combined mild hypothermia group .6 hours late,r hip-pocampus were extracted from rat heads.Respectively, spectrophotometer was applied to measure the content of H2S, Western blot for the expres-sions of NR2 A,NR2 B and pC-REB, and RTP-CR for mRNA level of brain derived neurotrophic (BDNF). HE staining was also performed on brain tissues 72hours after reperfusion on 4 rats from each group to evaluate the pathological changes of pyramidal neurons in CA1 region. R esul ts The content of H 2 S increased in each of the four groups after ischemia-reperfusion compared with sham operation group ( 15.2 ±2.0 nmol/g) (P<0.05).In comparison to model group (25.2 ±3.5 nmol/g), NaHS group (37.5 ±4.0 nmol/g) and NaHS combined mild hypothermia group (38.7 ±4.4nmol/g ) resulted in significant high content of H2S(P<0.05), while mild hypothermia group(26.5 ±3.5nmol/g ) got a mild increase(P>0.05).The gray values of NR2A and NR2B in each group increased compared with sham operation group(P<0.05), re-sulting in NR2A/NR2B<1 in model group and mild hypothermia group while NR2A/NR2B>1 in NaHS group and NaHS combined mild hy-pothermia group.Compared with the expression of p-CREB(0.55 ±0.06) in model group, there were significant increases in mild hypother-mia group(0.99 ±0.15), NaHS group(1.05 ±0.12), NaHS combined mild hypothermia group(1.02 ±0.15)(P<0.05).Compared with the expression of BNDF mRNA(0.83 ±0.12) in model group, there were significant increases in mild hypothermia group (1.11 ±0.13), NaHS group(1.27 ±0.16), NaHS combined mild hypothermia group(1.35 ±0.16)(P<0.05).In comparison to model group, there were signifi-cant alleviation in the injury of pyramidal neurons in hippocampal CA1 region in mild hypothermia group, NaHS group, NaHS combined mild hypothermia group, with the best effect in NaHS combined mild hypothermia group . Conclusion Hydrogen sulfide combined mild hypo-thermia can selectively activate synaptic NMDA receptors and trigger the prosurvival CREB signaling pathway to exert brain resuscitation .