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Biomedical subjects

Ming He

Publications and source records attributed to Ming He.

At least 19 recordsLinked to original sources
PubMed2006

Chiral N-heterocyclic carbene catalyzed, enantioselective oxodiene Diels-Alder reactions with low catalyst loadings.

Chiral N-heterocyclic carbene (NHC) catalyzed redox reactions of racemic alpha-chloroaldehydes lead to the generation of chiral enolates suitable for highly enantioselective inverse-electron-demand 1-oxodiene Diels-Alder reactions. Significantly, these reactions proceed under mild, operationally friendly reaction conditions (EtOAc, room temperature, 2-8 h) using less than 1 mol % of a chiral N-mesityl triazolium salt as the precatalyst. A broad array of densely functionalized dihydropyran-2-ones bearing either aliphatic or aromatic substiutents are formed in excellent yields and exceptional enantioselectivities from readily available reactants. Stereochemical mismatching between the racemic starting materials and the chiral catalyst is avoided by rapid epimerization of the chloroaldehydes under the reaction conditions.

Aldehydes↗
PubMed2006

Comparative pharmacology and cloning of two novel arachnid sodium channels: Exploring the adaptive insensitivity of scorpion to its toxins.

Scorpion toxins have been found lacking effect on Na(+) current of its own sodium channel, whereas the molecular mechanism remains mystery. In this study, the binding affinity of pharmacologically distinct scorpion toxins was found much weaker to scorpion (Buthus martensii) nerve synaptosomes than to spider (Ornithoctonus huwena) ones. The sodium channel cDNA from these two species were further cloned. The deduced proteins contain 1871 and 1987 amino acids respectively. Several key amino acid substitutions, i.e., A1610V, I1611L and S1617K, are found in IVS3-S4 constituting receptor site-3, and for receptor site-4, two residues (Leu-Pro) are inserted near IIS4 of scorpion sodium channel.

Adaptation, Physiological↗
PubMed2006

Highly enantioselective azadiene Diels-Alder reactions catalyzed by chiral N-heterocyclic carbenes.

Highly enantioselective, N-heterocyclic carbene (NHC)-catalyzed aza-Diels-Alder reactions are described. A novel chiral triazolium salt based on the cis-1,2-aminoindanol platform serves as an efficient precatalyst for the NHC-catalyzed redox generation of enolate dienophiles that undergo LUMOdiene-controlled Diels-Alder reactions with N-sulfonyl-alpha,beta-unsaturated imines in good yields and with exceptional diastereo- and enantioselectivities (>99% ee). In contrast to uncatalyzed variants, this organocatalytic process proceeds at room temperature without stoichiometric reagents, producing synthetically valuable, enantiomerically pure cis-3,4-disubstituted dihydropyridinone products.

Journal Article↗
PubMed2006

Small interfering RNA-mediated silencing of cytochrome P450 3A4 gene.

RNA interference (RNAi) is a specific and powerful tool used to manipulate gene expression and study gene function. The cytochrome P450 3A4 (CYP3A4) can metabolize more than 50% of drugs. In the present study, we investigated whether vector-expressed small interfering RNAs (siRNAs) altered the CYP3A4 expression and function using the Chinese hamster cell line (V79) overexpressing CYP3A4 (CHL-3A4). Three different siRNA oligonucleotides (3A4I, 3A4II, and 3A4III) were designed and tested for their ability to interfere with CYP3A4 gene expression. Our study demonstrated that transient transfection of CHL-3A4 cells with the 3A4III siRNAs, but not 3A4I and II, significantly reduced CYP3A4 mRNA levels by 65% and protein expression levels by 75%. All these siRNAs did not affect the expression of CYP3A5 at both mRNA and protein levels in V79 cells overexpressing CYP3A5. Transfection of CHL-3A4 cells with 3A4III siRNAs significantly diminished the cytotoxicity of two CYP3A4 substrate drugs, cyclophosphamide and ifosfamide, in CHL-3A4 cells, with the IC50 increased from 55 to 210 microM to >1000 microM. Nifedipine at 5.78, 14.44, and 28.88 microM was significantly (P < 0.01) depleted by approximately 100, 40, and 22%, respectively, in S9 fractions from CHL-3A4 cells compared with parental CHL-pIC19h cells. In addition, transfection of the CHL-3A4 cells with vectors expressing the 3A4III siRNAs almost completely inhibited CYP3A4-mediated nifedipine metabolism. This study demonstrated, for the first time, the specific suppression of CYP3A4 expression and function using vector-based RNAi technique. The use of RNAi is a promising tool for the study of cytochrome P450 family function.

Animals↗
PubMed2006

[Estimation of morbidity risk in aged patients undergoing resections of esophagus carcinoma and gastric cardiac carcinoma using physiological and operative severity score].

OBJECTIVE: To test the clinical validity of physiological and operative severity score for the enumeration of mortality and morbidity (POSSUM) in aged patients undergoing resections of esophagus carcinoma and gastric cardiac carcinoma. METHODS: POSSUM was used in 167 aged patients undergoing esophagus carcinoma and gastric cardiac carcinoma resection. The physiological score and the operative severity score were compared between the groups with and without postoperative complications. The morbidity rates were calculated. Observed morbidity rates were compared with the rates predicted by POSSUM. RESULTS: Seventy-six of the 167 patients suffered from postoperative complications. The physiological score of the group with complications was 16.75 +/- 0.4, significantly higher than that of the group without complications (15.4 +/- 0.3, P < 0.0017). The number of the patients with complications predicted by POSSUM was 70, not significantly different from the observed number of the patients with complications (78, P = 0.378). There were 94 person-times of complications in these 78 patients, 12 being with hypertension, 37 with arrhythmia; 5 with asthma; 3 with febrile; 2 with pneumonia; 1 with atelectasis; 1 with respiratory failure; 3 with wound infection; 3 with wound liquefaction; 2 with anastomotic leakage; 6 with phlebitis; 2 with pneumothorax; 2 with acute dilatation of stomach; 1 with chylothorax; 2 with hemorrhage; 1 with cardiac failure; 1 with infectious shock; 2 with empyema; 2 with deep vein thrombo-embolism; 1 with pulmonary infarction; 1 with cerebral infarction; 1 with urinary infection; and 1 with psychiatric symptom. CONCLUSION: The POSSUM makes satisfactory prediction of postoperative morbidity in aged patients undergoing esophagus carcinoma and gastric cardiac carcinoma resection. Intensive monitoring and organ supporting therapy after the operation according to the score is of great benefit to decrease the post-operative complications.

Aged↗
PubMed2006

[Cardioprotective effects of sodium ferulate mediated by nitric oxide on ischemia-reperfusion injured myocardium: experiment with isolated rat hearts].

OBJECTIVE: To investigate the cardioprotective effects of sodium ferulate (SF) mediated by nitric oxide on ischemia-reperfusion injured myocardium. METHODS: Fifty-six SD rats were killed. Their hearts were isolated and randomly divided into 7 equal groups: ischemia/reperfusion group (I/R group), ischemic/preconditioning (IP group, to be perfumed with anoxic and reoxygenated fluid several times so as to produce protection against continuous and severe ischemia), SF pretreatment group (to be perfused with fluid with SF and then made I/R model), L-NAME + SF group (to be perfused with fluid with SF and L-NAME, a NO inhibitor, and then made I/R model), glibenclamide (Glib) + SF group (to be perfused with Glib + SF and then made I/R model)), L-NAME + Glib + SF group (to be perfused with L-NAME + Glib + SF and then made I/R model)), and control group (normal isolated hearts). Electrocardiography was conducted and left ventricular systolic pressure (LVSP), dp/dt(max), and heart rate (HR) were measured. By the end of the experiment 0.5 grams of tissue was taken from the left ventricle. The levels of superoxide dismutase (SOD), malonyldialdehyde (MOD), NO, and cyclic guanosine monophosphate (cGMP) were detected. RESULTS: The levels of LVSP, dp/dt(max), and HR of the SF pretreatment group and IP group were all significantly higher than those of the I/R group (all P < 0.01) without significant differences between these 2 groups (all P > 0.05). The levels of LVSP, dp/dt(max), and HR of the L-NAME, Glib + SF, and L-NAME + Glib + SF groups were all significantly lower than those of the SF pretreatment group and IP group (all P < 0.01). Ventricular extrasystole (VE) and ventricular tachycardia (VT) during re-perfusion period occurred in all hearts of the I/R group, however, the incidence rates of VE and VT of the IP and SF groups were all significantly lower than those of the I/R group (all P < 0.01), however, without significant differences between the IP and SF groups (all P > 0.05). The incidence rate of VE and VT of the L-NAME, Glib + SF, and L-NAME + Glib + SF groups were all significantly higher than those of the SF group (all P < 0.01). The myocardium MDA content of the I/R group was significantly higher and the SOD activity significantly lower in comparison with the control group (both P < 0.01); the myocardium MDA contents of the IP and SF groups were significantly lower and the SOD activity levels significantly higher in comparison with the I/R group (all P < 0.01), however, with significant differences between theses 2 groups (both P > 0.05); the myocardium MDA contents were significantly higher and the SOD activity levels significantly lower in the L-NAME, Glib + SF, and L-NAME + Glib + SF groups in comparison with the SF and IP groups (all P < 0.01). The myocardium NO(2)(-)/NO(3)(-) and cGMP contents of the I/R group were both significantly lower than those of the control group (both P < 0.01), and the myocardium NO(2)(-)/NO(3)(-) and cGMP contents of the IP and SF groups were both significantly higher than those of the I/R group (both P < 0.01), however, without significant differences between these 2 groups (both P > 0.05). The myocardium NO(2)(-)/NO(3)(-) and cGMP contents of the L-NAME, Glib + SF, and L-NAME + Glib + SF groups were all significantly lower than those of the SF group (all P < 0.01). CONCLUSION: SF pretreatment significantly improves the releasing of NO, decreases oxygen free radicals, and relieves myocardial ischemia reperfusion injury. The opening of the ATP-sensitive potassium channels induced by the cGMP way of NO activation may be an important pathway in the cardioprotective effects of SF pretreatment.

Animals↗
PubMed2006

Upregulation of 14-3-3 isoforms in acute rat myocardial injuries induced by burn and lipopolysaccharide.

1. Burn-induced myocardial injuries can be acute due to loss of body fluid and blood redistribution, and subacute due to pathogenic toxins of infecting bacteria. The goal of this study was to examine expression of 14-3-3 in the injured myocardium. 2. Myocardial injury models were created in vivo by subjecting rats to severe burn and administration of lipopolysaccharide. RT-PCR and Western blotting were employed to assess the expression of 14-3-3 proteins and messenger ribonucleic acid (mRNA) for 14-3-3eta and gamma in the myocardium, respectively. 3. In the two models, we found that 14-3-3 proteins were induced in a time-dependent fashion. Such a change is at least in part attributed to increases in mRNAs for 14-3-3gamma and eta. In contrast to 14-3-3xi, whose mRNA was not detectable in the heart, mRNA for 14-3-3gamma was found significantly elevated between 24-48 h after burn. 14-3-3eta mRNA exhibited a marked increase at 3 h continuing to 12 h and then decreased nearly to a normal level after 48 h. In lipopolysaccharide-treated intact rats, 14-3-3gamma mRNA in myocardium showed a significant increase, reaching a peak at 4 h, followed by a decrease at 6 h. In contrast, 14-3-3eta mRNA had a slight increase without significance. 4. Our results suggest that 14-3-3 may play a role in both acute and subacute (postburn infectious) phases of severe burn.

14-3-3 Proteins↗
PubMed2006

[Study on oxidant strengthening photocatalytic degradation of DMF over TiO2 fiber catalyst].

Oxidant strengthening the degradation of DMF aqueous solution was investigated when TiO2 fiber is used as the photocatalyst. When the UV light was absent, ozone per se could not make DMF degrade, which proves that DMF is a stable substance. But ozone could increase obviously photocatalytic degradation rate of DMF in O3/TiO2 (F). Under the same reaction condition, photocatalytic degradation rate and speed of DMF in O3/TiO2 (F) was almost 1.5 times and 2 times higher than that in air/ TiO2 (F) and H2O2/TiO2 (F) respectively. COD analysis showed DMF was almost mineralized completely when the reaction was carried out for 120 min. Through Hinsberg test secondary amine was proved as one of intermediates in the process of DMF photocatalytic degradation. Rise of pH value of reaction solution also showed that amine was produced in the photocatalytic reaction process. Degradation speed of DMA in O3/TiO2 (F) was higher than that in air/TiO2 (F). The increasing degradation rate and speed of DMF was mainly caused by fast degradation of secondary amine in the process of DMF photocatalytic degradation in O3/TiO2 (F).

Biodegradation, Environmental↗
PubMed2006

[Effect of multi-glycosides of tripterygii on latent autoimmune diabetes in adults in early stage].

OBJECTIVE: To observe the effect of multi-glycosides of tripterygii (MT) on latent autoimmune diabetes of adults (LADA) in early stage. METHODS: The diabetic patients were divided randomly into the control group treated with insulin alone and the treated group treated with insulin and MT. Levels of insulin, C-peptide, glutamic acid decarboxylase antibody (GADAb) and islet cell antibody (ICA) were detected and clinical features of the disease were observed. RESULTS: There was no difference between the control group and the treated group in body mass index (BMI), the occurrence of diabetic keto-acidosis and the function of liver and kidney (P >0.05). After 6 months' treatment, the positive rate of GADAb and ICA decreased, plasma levels of fasting and 2 hrs post-prandial C-peptide and also 2 hrs post-prandial true insulin in the treated group increased (P <0.01), while all the above indexes improved more significantly after 1 year's treatment (P <0.01). CONCLUSION: Compared treatment of insulin with multi-glycosides of tripterygii in early stage of LADA has better effects in relieving autoimmune injury and recovering function of pancreatic island than insulin alone.

Adult↗
PubMed2006

[Study of cytokines secreted by tumor-draining lymph node cells from lung cancer patients induced with different stimulators].

AIM: To investigate the influence of different stimulators on cytokines secretion of tumor-draining lymph node (TDLN) cells and study antitumor effects and mechanism of TDLN cells. METHODS: IL-12 p70, IFN-gamma, TNF-alpha and NO which were secreted by TDLN cells induced by different stimulators (IL-2 group, IL-2+autologous tumor antigen group, IL-2+GM-CSF+IL-4+autologous tumor antigen group and IL-2+GM-CSF+IL-4+LPS group) were detected by ELISA and Griess after TDLN cells were stimulated for 7, 14 and 21 d. RESULTS: The rate of CD83(+) cells of TDLN cells induced by IL-2+GM-CSF+IL-4+autologous tumor antigen and IL-2+GM-CSF+IL-4+LPS was significantly increased. The TDLN cells in the two groups secreted much more IL-12 p70, IFN-gamma and TNF-alpha than IL-2 group and IL-2+autologous tumor antigen group. The TDLN cells stimulated by IL-2+GM-CSF+IL-4+LPS secreted significantly more NO than the other three groups. TDLN cells in each group secreted IL-12 p70, IFN-gamma and NO at the highest level after TDLN cells were stimulated for 14 d. CONCLUSION: Different stimulators can make TDLN cells produce different number of CD83(+) cells (DC), which gives TDLN cells different antitumor activity.

Adjuvants, Immunologic↗
PubMed2006

[Effects of alendronate on bone mineral density, cytokines and indices of bone metabolism in postmenopausal osteoporotic patients].

OBJECTIVE: To observe the effects of alendronate on bone mineral density (BMD), cytokines and indices of bone metabolism in postmenopausal osteoporotic (PMO) patients. METHODS: 185 PMO patients, aged from 55 to 60 years, were randomized into three groups. All of them received a kind of calcium preparation, 1.0 g/d. Group A, 69 patients, received alendronate, 10 mg/d; group B, 66 patients, received tibolone 1.25 mg/d. The remaining patients, group C, received calcium preparation only. 20 women of 55 - 60 (57.4 +/- 3.5) years old were taken as normal controls. Dual-energy X-ray absorptiometry and measurement of a series of biochemical indices were carried out before and after medication at 24th and 48th week. RESULTS: After medication, BMD increased in alendronate and tibolone group. The increment in spine BMD was 2.53% and 3.65% (P < 0.05) and that in nondominant proximal femur BMD was 7.17% and 3.01% (P < 0.001). In the tibolone group, the levels of estradiol (E(2)) increased rapidly (P < 0.01), but those of IL-6, TNFalpha and type I collagen cross-linked N-telopeptides (NTX) decreased (P < 0.01). In the alendronate group, no change of levels of E(2) happened, while levels of alkaline phosphatase (ALP) and osteocalcin (BGP) increased (P < 0.05) and levels of NTX decreased (P < 0.05). There was no change of the levels of other parameters. In the calcium preparation group and control group, the levels of BMD, E(2), ALP, BGP and insulin-like growth factor I decreased (P < 0.05), while those of IL-6, TNFalpha and NTX increased (P < 0.05). CONCLUSION: Alendronate can significantly improve BMD as tibolone do. Thus it plays an important role in the treatment of osteoporosis. However calcium tablet can not prevent the loss of bone.

Alendronate↗
PubMed2005

Adsorption of anionic and nonionic surfactant mixtures from synthetic detergents on soils.

Adsorption of anionic surfactant (sodium dodecylbenzenesulfonate, SDBS) and nonionic surfactant (an alcohol ethoxylates with 12 carbons and 9 oxyethyl groups, A12E9) mixtures, widely used as the major constituents of synthetic detergents in China and become the most common pollutants in the environment, on soils was conducted to investigate the behavior of mixed surfactants in soils. The effects of addition order and mixing ratios of two surfactants, associated with pH and ion strength in solutions, on adsorptions were considered. The results show that saturated adsorption amount of SDBS and A12E9 on soils decreased respectively when A12E9 was added into soils firstly compared with that secondly, possibly resulting from the screening of A12E9 to part adsorption sites on soils and the hydrocarbon chain-chain interactions between SDBS and A12E9. The adsorption of SDBS and A12E9 on soils was enhanced each other at pre-plateau region of isotherms. At plateau region of isotherms, the adsorption of SDBS on soils decreased with the increase of molar fraction of A12E9 in mixed surfactant solutions, while that of A12E9 increased except the molar ratio of SDBS to A12E9 0.0:1.0. With the increase of pH in mixed surfactant solutions, adsorption amount of SDBS and A12E9 on soils decreased, respectively. The reduction of ion strength in soils resulted in the decrease of adsorption amount of SDBS and A12E9 on soils, respectively.

Adsorption↗
PubMed2005

Changes of occludin expression in intestinal mucosa after burn in rats.

In severely burned rats, hyperemia, edema and other pathological injuries occur in the intestinal mucosa. Ultramicroscopically, the microvilli, tight junction and organelles are disrupted. Occludin is a functional component of tight junctions. The purpose of the present study is to investigate changes of occludin expression, and to further elucidate the relationship between occludin expression and ultrastructure damage. The fluorescence intensity of occludin was detected in intestinal wall by the method of immunofluorescence histochemistry and confocal laser scanning microscopy (CLSM). Expression of occludin and its mRNA were determined by western blotting and RT-PCR, respectively. Changes of intestinal mucosa ultrastructure were observed by TEM. The results showed that fluorescence intensity of occludin at 3PBH was enhanced, higher than that of the control group, being 80.77+/-8.38 and 72.86+/-4.74, respectively, and reached a peak at 12PBH (116.14+/-6.89). The expression levels of occludin at 3PBH and 6PBH were 1.21+/-0.02 and 1.53+/-0.14 times that of the control group, respectively, and there were significant differences (P<0.01) between 3PBH group and 6PBH group and control group. The levels of occludin mRNA were also enhanced. At 12PBH, the level reached a peak (P<0.01), being 2.00+/-0.24 times that of the control group. Coincidently, the structure of the tight junction between epithelial cells was disrupted on a large scale under TEM. We speculate that up-regulation of epithelial occludin may play a role in enhancing paracellular permeability and be related to the damage to the tight junction.

Animals↗
PubMed2005

Catalytic Synthesis of gamma-Lactams via direct annulations of enals and N-sulfonylimines.

[reaction: see text] Cinnamaldehydes and N-sulfonylimines undergo direct annulations to cis-disubstituted gamma-lactams via the intermediacy of catalytically generated homoenolates. Critical to the success of this process was overcoming inhibition of the N-heterocyclic carbene catalyst by the electrophilic imines. The overall process proceeds with good yields and diastereoselectivites and requires no stoichiometric reagents or additives.

Journal Article↗
PubMed2005

Inhibitory effects of sasanquasaponin on over-expression of ICAM-1 and on enhancement of capillary permeability induced by burns in rats.

The purpose of this study was to investigate the effects of sasanquasaponin (SQS) on ICAM-1 expression and capillary permeability induced by burns in rats. Male adult Sprague-Dawley (SD) rats were subjected to burns in the presence or absence of SQS, and then intravenously injected with Evans blue (60.0 mg/kg body weight). The levels of soluble ICAM-1 (sICAM-1) in sera were assayed using ELISA and the expression levels of transmembrane ICAM-1 (mICAM-1) in aorta were determined by Western blots and ICAM-1 mRNA levels were measured using semi-quantification RT-PCR. The capillary permeability was determined spectrophotometrically. The results showed that SQS markedly lowered the levels of sICAM-1 in sera, and considerably inhibited the over-expression as well as transcription of mICAM-1 in rat aorta. In addition, SQS dramatically inhibited the enhancement of dermal capillary permeability induced by burns in a dose-dependent manner. These results suggest that SQS, developed from Chinese traditional herbs, might be effective in decreasing inflammation induced by burns.

Animals↗
PubMed2005

Neuronal activity regulates viral replication of herpes simplex virus type 1 in the nervous system.

Herpes simplex virus types 1 and 2 (HSV-1, -2) infect and also establish latency in neurons. In the present study, the authors investigated the influence of neuronal activity on the replication of HSV-1. The results showed that the sodium channel blocker tetrodotoxin (TTX) and the inhibitory neurotransmitter gamma-aminobutyric acid (GABA) could significantly increase viral replication in primary neuronal cultures, by two- to fourfold. In contrast, KCl reduced viral production by at least 80% in the same cultures. Inhibitors of GABA(A) receptors completely abolished the effects of GABA. Intravitreously injected TTX in a mouse corneal scarification model enhanced the viral titers > 10-fold in both the trigeminal ganglia and the brain. At 2 h post infection, both TTX and GABA significantly up-regulated the levels of transcription for the viral immediate early (IE) genes ICP0, ICP4, and ICP27, as revealed by real time PCR. These results indicate that the neuronal excitation status may dictate the efficiency of HSV-1 viral replication, probably by regulating the levels of viral IE gene expression. These are the first findings connecting neuronal activity to the molecular mechanisms of HSV replication in the nervous system, which may significantly influence our view of herpesvirus infection and latency.

Animals↗
PubMed2005

[Clinical study on treatment of pulmonary interstitial fibrosis with ginkgo extract].

OBJECTIVE: To observe the effect of ginkgo extract on pulmonary interstitial fibrosis. METHODS: Forty-five patients with pulmonary interstitial fibrosis were randomly divided into two groups, the treated group (n = 30) received ginkgo biloba extract 1 g, three times a day; the control group received prednisone 30 mg, once a day, the therapeutic course for both groups was 3 months. Changes of clinical symptoms, pulmonary function, arterial partial pressure of oxygen, computerized tomography (CT), interleukin-6 (IL-6), interleukin-8 (IL-8) and tumor necrosis factor-alpha(TNF-alpha) in the two groups were observed before and after treatment. RESULTS: The efficacy of treatment in the two groups showed insignificant difference, clinical symptoms, pulmonary function, arterial partial pressure of oxygen were improved after treatment (P < 0.05), and the levels of IL-6, IL-8 and TNF-alpha significantly decreased after treatment as compared with those before treatment in the two groups. The occurrence of pulmonary infection was less in the treated group than that in the control group (P <0.05). CONCLUSION: Ginkgo is effective in treating pulmonary interstitial fibrosis.

Aged↗