Salmonella enterica serovar Cerro 87, which was isolated from a commercial egg-producing farm, has a phosphorothioated DNA backbone resulting DNA degradation(Dnd) during the pulsed field gel electrophoresis (PFGE) process. In this research, a gene deletion mutant XTG103 was engineered with the entire dnd gene cluster knocked out by double crossover using vector pKOV-kan, and lost Dnd phenotype corre- spondingly. We regulated the DNA phosphorothioation by heterogenous expression of dnd gene cluster with an isopropyl ?-D-1-thiogalactopyranoside (IPTG) inducible promoter PlacZ.

Sulfur fumigation (SF) is a universal phenomenon in primary processing of Traditional Chinese Medicine (TCM) in modern times. In the process, fumigation, sulfur or both of them act on the TCMs. Some active components of TCMs change quantitatively or qualitatively during the processing. At the same time, the sulfur dioxide and heavy metal would remain and cause a serious influence on quality and future development of TCM. This article reviews the chemical compositions change after SF to study the change law and their influence on quality. This article provide references for SF in TCMs' processing for a better and safer quality.
Drug Contamination ; Fumigation ; methods ; Medicine, Chinese Traditional ; methods ; Quality Control ; Sulfur ; chemistry ; Technology, Pharmaceutical ; methods

OBJECTIVETo study the inhibition effect of celastrol on neovascularization.

METHODSThe effect of celastrol on the in vitro proliferation of endothelial cell of vessel (ECV) was examined by MTT assay. The effect of celastrol on endothelial cell migration, tube formation on Matrigel and Chick chorioallantoic membrane angiogenesis was also examined. Matrigel plug assay was used to evaluate the effect of celastrol on angiogenesis in vivo.

RESULTSThe proliferation of ECV was inhibited significantly by celastrol with IC(50) being 1.33 microg/ml. Celastrol inhibited endothelial cell migration and tube formation in a dose-dependent manner. Celastrol also inhibited angiogenesis both in Matrigel plug of mouse model and in chick chorioallantoic membranes.

CONCLUSIONCelastrol, which can inhibit angiogenesis, could be developed as an antiangiogenic drug.

Angiogenesis Inhibitors ; pharmacology ; Animals ; Endothelial Cells ; drug effects ; Mice ; Mice, Inbred BALB C ; Triterpenes ; pharmacology

OBJECTIVETo assess the effect of oxidative stress in development of acute high altitude response (AHAR) during the process of strong physical work at high altitude and its change after return to lower altitude.

METHODSNinety-six officers and soldiers of rapid entering into high altitude (3 700 m) with strong physical work were analyzed, all subjects were male, aged 18-35 years. According to the symptomatic scores of AHAR were divided into 3 groups: severe AHAR (group A, n = 24), mild AHAR (group B, n = 47) and without AHAR (group C, n = 25). Levels in serum 8-iso prostaglandinF2alpha(8-iso-PGF2alpha), superoxide dismutase (SOD) and malonaldehyde (MDA) were measured at higher altitude stayed 50 d and after return to lower altitude (1 500 m) 12 h and 15 d, and 50 healthy volunteers (group D) at 1 500 m altitude served as controll.

RESULTSLevels of serum 8-iso-PGF2alpha and MDA [(9.53 +/- 0.47) microg/L, (8.91 +/- 0.39) micromol/L] were significantly higher in group A than those in group B [(8.34 +/- 0.42) microg/L, (7.31 +/- 0.32) micromol/L] , group C [(7.02 +/- 0.48) microg/L, (6.41 +/- 0.23) micromol/L] and group D [(5.13 +/- 0.56) microg/L, (5.48 +/- 0.33) micromol/L], (all P < 0.01), and serum SOD [(52.08 +/- 3.44) micro/ml] was significantly lower in group A than that in group B [62.27 +/- 2.54) micro/ml], group C [(71.99 +/- 3.35) micro/ml] and group D [(80.78 +/- 3.44) micro/ ml] (all P < 0.01), there were significant differences between group B and C, C and D (all P < 0.01). At altitude 3 700 m 50 d, AHAR scores was positively correlated with serum 8-iso-PGF2alpha and MDA (all P < 0.01), negatively correlated with SOD (P < 0.01). Serum 8-iso-PGF2alpha and MDA were negatively correlated with SOD (all P < 0.01). Levels of serum 8-iso-PGF2alpha and MDA were significantly higher at altitude of 3 700 m 50 d than those at altitude of 1 500 m 12 h,15 d in group D (all P < 0.01), and serum SOD was significantly lower than that at 1 500 m 12 h,15 d in group D (all P < 0.01), there were significantly difference between at 1 500 m 12 h and 15 d (all P < 0.01), there were no difference between at 15 d in group D (all P > 0.05).

CONCLUSIONThe more serious of oxidative stress and oxidative/antioxidative imbalance, the more serious of AHAR, oxidative stress and oxidative/antioxidative imbalance may be involved in the development of AHAR. The changes were obviously improved after return to lower altitude 12 h, and recovered to normal after 15 d.

Adolescent ; Adult ; Altitude ; Altitude Sickness ; physiopathology ; Humans ; Male ; Oxidative Stress ; physiology ; Physical Exertion ; physiology ; Young Adult

OBJECTIVETo investigate the biomechanical differences between the surgery and adjacent segments of intervertebral discs in the lower lumbar spine, which were implanted with Coflex into the segments of L4, and L5S1, respectively.

METHODSThree finite-element models (the model of the intact lower lumbar sacrum,the L4.5 and L5S1 segments implanted by Coflex) were developed, respectively. According to the spinal three-column loading theory, three models were forced by the physiological loads of upright standing, flexion and extension. The stress of the different areas of the disc annulus, the changes of intervertebral dorsal height and the degree of nucleus pulposus pressure were compared and analyzed.

RESULTSCoflex implanted into the L4.5 and L5S1 segments in compression and extension could both decrease the stress of the posterior area of intervertebral disc in the surgery segment, resist the changes of the intervertebral disc dorsal height and reduce the perssure of nucleus pulposus. Furthermore, the stress of the L5S1 segment decreased when Coflex fixed the L4.5 segment in extension. However, when Coflex fixed the L5S1 segment, the stress of L4.5 segment had no significant changes.

CONCLUSIONCoflex fixing the L4,5 and L5S1 segments can effectively decrease the stress of the surgery segmental discs, respectively. Furthermore, Coflex fixing L4,5 segment may play a biomechanical role in reducing the stress of L5S1 segment.

Adult ; Biomechanical Phenomena ; Finite Element Analysis ; Humans ; Internal Fixators ; Intervertebral Disc ; physiopathology ; surgery ; Lumbar Vertebrae ; surgery ; Male ; Stress, Mechanical

Animals ; History, 20th Century ; Humans ; Influenza A Virus, H1N1 Subtype ; genetics ; immunology ; isolation & purification ; Influenza, Human ; epidemiology ; history ; immunology ; virology ; Russia ; epidemiology

Animals ; Global Health ; History, 20th Century ; Humans ; Influenza A Virus, H1N1 Subtype ; genetics ; isolation & purification ; metabolism ; pathogenicity ; Influenza, Human ; epidemiology ; history ; virology ; Spain ; epidemiology ; Viral Proteins ; genetics ; metabolism

OBJECTIVETo investigate performance of a biotinylated imaging probe 3a for targeted imaging of breast cancer cells.

METHODSUltraviolet absorption spectrum and fluorescence spectrum were employed to analyze the spectral characteristics of 3a. The fluorescence spectrums of 3a treated with different concentrations of glutathione (GSH) were obtained to determine the sensibility of 3a to GSH. Flow cytometry was used to determine the cellular uptake of 3a by MCF-7 cells, MDA-MB-231 cells and Hs 578Bst cells in the presence or absence of biotin, and the imaging performance of 3a in the 3 cell lines was assessed under an inverted fluorescent microscope. The toxicity of 3a to the cells was evaluated using MTT method.

RESULTS3a showed the strongest absorption peak at 510 nm, and its fluorescence emission signal was the strongest at 544 nm. As the concentration of GSH increased (0-6 mmol/L), 3a exhibited an increasing fluorescence signal at 544 nm. The cellular uptake of 3a was markedly higher in MDA-MB-231 cells and MCF-7 cells than in Hs 578Bst cells. The imaging studies showed that 3a had a good breast cancer cell-targeting property and produced clear images under fluorescent microscope. MTT assay demonstrated no obvious toxicity of 3a in Hs 578Bst cells even at the concentration of 20 µmol/L, but MCF-7 cells and MDA-MB-231 cells exposed to 2-20 µmol/L 3a showed a lowered cell viability.

CONCLUSION3a is capable of targeted imaging of breast cancer cells mediated by biotin. 3a at the concentration of 2-20 µmol/L has minimal cytotoxicity to normal breast cells but can lower the viability of breast cancer cells.

pHZ1080, an E. coli-Streptomyces shuttle expression vector was constructed in order to explore the utilization of lambda phage regulated expression elements in Streptomyces. A 2.7 kb polyketide synthase (PKS) gene from Streptomyces sp. FR-008 was inserted into downstream of lambda phage promoter (PR) to give the shuttle plasmid, pHZ1067. The PKS protein was expressed in Streptomyces lividans carrying pHZ1067 in a heat-dependent manner, as it did in E. coli. The PKS protein expressed in both hosts with same molecular weight was detected by SDS-PAGE and Western-blot. The successful heat-induced expression of PKS suggested that pHZ1080 was useful and convenient for heat-induced expression of heterologous genes in both E. coli and Streptomyces.
Amino Acid Sequence ; Base Sequence ; Blotting, Western ; Cloning, Molecular ; Genetic Vectors ; genetics ; Molecular Sequence Data ; Multienzyme Complexes ; genetics ; metabolism ; Recombinant Proteins ; genetics ; metabolism ; Streptomyces ; enzymology ; genetics ; Temperature

OBJECTIVETo investigate the effect of a continuous infusion of low-dose dexmedetomidine on patient-controlled analgesia (PCA) with fentanyl in elderly patients after total hip replacement.

METHODSForty patients (ASA I-II) aged 66-81 years after total hip replacement were randomized equally into the control and test groups. The patients in the test group received continuous infusion of dexmedetomidine at the rate of 0.2 µg·kg(-1)·h(-1) from the beginning to the end of PCA with fentanyl after the surgery, while those in the control group received normal saline. The cumulative fentanyl dose, VAS pain scores and Ramsay sedation score were recorded at 0, 4, 8, 12 and 24 h after the surgery.

RESULTSAll the patients in the two groups reported good pain relief and none needed additional fentanyl. The VAS pain score was significantly lower (P<0.05 or 0.01), while the Ramsay sedation scores higher (P<0.05) in the test group than in the control group. The cumulative fentanyl dose was significantly lower in the test group (P<0.05 or 0.01). The incidence of such adverse effects as nausea and vomiting was significantly lower in the test group (P<0.05).

CONCLUSIONPCA with fentanyl combined with low-dose dexmedetomidine infusion is safe for elderly patients, and can decrease fentanyl consumption and improve the effect of PCA with fentanyl.

Aged ; Aged, 80 and over ; Analgesia, Patient-Controlled ; methods ; Arthroplasty, Replacement, Hip ; Dexmedetomidine ; administration & dosage ; therapeutic use ; Female ; Fentanyl ; administration & dosage ; therapeutic use ; Humans ; Infusions, Intravenous ; Male ; Pain, Postoperative ; drug therapy