Objective To investigate the relationship between the p27~(kip1) expression and the change of radiosensitivity of esophageal cancer cells.Methods Radio-resistant cells (EC9706R) were gradually isolated by means of repeated gamma-ray irradiation (6 000 cGy in total) upon human squamous esophageal carcinoma cells (EC9706).The radiosensitivity of these two types of cells was measured by standard colony formation assays,their cell cycle distribution analyzed by flow cytometry respectively,and the p27~(kip1) expression detected by immunocytochemistry.Results As compared with their parent cells,the isolated human squamous esophageal carcinoma cells(EC9706) showed clearly greater radio-resistance(for EC9706R,SF_2=65.71%,D_0=2.20 Gy,D_q=1.61 Gy,N=2.07,and for EC9706,SF_2=46.72％,D_0=1.61 Gy,D_q=0.99 Gy,N=1.85;SF_2,D_0,Dq and N were all higher).As to the cell cycle distribution,the population of G_1 phase cells in EC9706R cells was significantly decreased,but the proportion of S phase cells was significantly increased as compared with the parent cells.Immunocytochemistry revealed that the p27~(kip1) expression of EC9706R cells was clearly lower than that of EC9706 cells.Conclusion Cell phase change due to the decrease of p27~(kip1) expression may be one of the mechanisms of the generation of radio-resistance in esophageal cancer cells.

Background Laser in situ keratomileusis (LASIK) is frequently performed to reduce or eliminate myopic refractive error.Some patients complain of a loss of visual function after surgery even when they have 20/20 visual acuity.One of the reasons is the change of asphericity of the cornea.Objective This study attempts to investigate the short-term changes of the anterior and posterior corneal asphericity after LASIK.Methods One hundred and seven myopic eyes of 54 subjects with the equivalent spherical diopter of -1.30 to -7.50 D who have received LASIK were enrolled in this prospective study.The Q-values of the posterior corneal surface for different corneal diameters (6mm,7mm,8mm and 9mm) were measured with Pentacam preoperatively and 1 month postoperatively.The correlations between Q-value,Q change (△Q),and the mean preoperative spherical equivalent refraction (SE),central corneal thickness (CCT),central ablation depth (AD) and residual bed thickness were investigated.Written informed consents were obtained from all the subjects prior to the clinical trial.Results The Q-values of the anterior and posterior corneal surfaces gradually decreased to negative values with the increase of corneal diameter in myopic eyes.Weak correlations were found between the asphericity of the anterior and posterior corneal surfaces from diameters of 6mm,7mm,8mm and 9mm (r=0.227,0.288,0.303,0.389;P=0.019,0.003,0.002 and 0.000,respectively).No statistically significant correlation was found between Q-value and the diopter of refractive error (P＞0.05).Both the anterior and posterior corneal Q-values varied toward the positive direction except that in the 9mm area of the posterior corneal surface at postoperative 1 month(t=-1.495,P=0.138).The increase of the anterior corneal asphericity (△Q) was more obvious than that of the posterior corneal surface and showed a positive correlation with ablation depth and a negative correlation with residual bed thickness.However,no statistically significant correlation was seen between △Q and these two parameters in the posterior corneal surface (P＞0.05).Conclusion The shape of the anterior and posterior corneal surface shows more prolateness as the increase of corneal diameter in myopic eyes.Both the anterior and the posterior corneal surfaces have an oblate shift within the ablation zone 1 month after LASIK.

BACKGROUNDIt is still unclear whether viral genetic variability influences response to interferon (IFN)-alpha treatment. Recent reports suggest that IFN-alpha effects may be associated with hepatitis B virus (HBV) post-transcriptional regulation. This study was designed to explore the heterogeneity of HBV post-transcriptional regulatory elements (HPRE) and the relationship between the diversity of HPRE and the response to IFN-alpha treatment.

METHODSThe HPRE sequences from 31 Chinese patients infected with HBV were determined by directly sequencing of polymerase chain reaction (PCR) product, and comparing them to those from Caucasian patients. Subsequently, eukaryotic expression vectors containing HPRE at various points were constructed and transfected into HepG2 cells, which were then exposed to recombinant human cytokines.

RESULTSThe T to C point mutation at nt 1504 and the C to T (G) at nt 1508 in HPRE were found in 21 and 19 patients with chronic hepatitis B, respectively; the C to T point mutation at nt 1509 was found in 17 patients. These point mutations did not exist in the HPRE of the Caucasian patients. The activity of the CAT gene obviously increased in the case of T to C point mutation at nt 1504, but did not change in the case of the C to T (G) mutations at nt 1508 and 1509. The activity of the CAT gene at these point mutations of HPRE could be inhibited by IFN-alpha/gamma and tumor necrosis factor (TNF)-alpha except for the point mutations at nt 1508 of HPRE which may escape the suppression role of IFN-alpha on HPRE.

CONCLUSIONSThere are point mutations between the HPRE of Chinese and Caucasian HBV patients, which might be correlated with response to IFN-alpha. The variation of HPRE might affect the function of HPRE and influence the regulative function of IFN-alpha other than that of IFN-gamma or TNF-alpha on HPRE.

Chloramphenicol O-Acetyltransferase ; metabolism ; Genes, Regulator ; Hepatitis B virus ; drug effects ; genetics ; Hepatitis B, Chronic ; drug therapy ; virology ; Humans ; Interferon-alpha ; pharmacology ; Interferon-gamma ; pharmacology ; Plasmids ; Point Mutation ; Tumor Necrosis Factor-alpha ; pharmacology

OBJECTIVETo establish a gas chromatography method for detecting the concentration of 1,1-dichloro-1-nitroethane in air of workplaces.

METHOD1,1-dichloro-1-nitroethane in air of workplaces was collected by activated charcoal tube, absorbed using carbon disulfide and analyzed by Gas Chromatography (FID) with FFAP capillary column.

RESULTSThe linear rang of 1,1-dichloro-1-nitroethane in this method was 4.0-858.2 microg/ml, the linear regression formula was Y = 283X-1076, the correlation coefficient was 0.9999, the lowest detection concentration was 0.4 mg/m3 (3L sampling air), the relative standard deviation (RSD) was 1.8%-4.1%, the desorption efficiency was 88.5%-90.6%, the breakthrough volume was > 0.7 mg, the sampling efficiency was 100%, the samples could be kept at ambient temperature for at least 7 days.

CONCLUSIONThe indicators of this method were conformed to the requirements of "Guide for establishing occupational health standards--Determination methods of air chemicals in workplace". This method could be used to detect 1,1-dichloro-1-nitroethane in air of workplaces.

Air Pollutants, Occupational ; analysis ; Chromatography, Gas ; methods ; Ethane ; analogs & derivatives ; analysis ; Nitroparaffins ; analysis ; Workplace

Communication ; Humans ; International Cooperation ; Medicine, Chinese Traditional ; trends ; Neoplasms ; therapy ; Organizations ; trends ; Patient Care ; Research

To identify adulterants from medicinal plants of Bletilla H. G. Reichenbach, the suitable candidate DNA barcoding of Bletilla was evaluated. In this study, the internal transcribed spacer (ITS) of nuclear ribosomal DNA, the LFY homologous gene intron 2 and chloroplast ycfl gene were amplified and sequenced from forty-one samples. The intra-specific and inter-specific divergences of Bletilla were calculated, and the identification efficiency was assessed using Barcoding Gap, NJ tree by K2P distance and BLAST1 method. The result showed the intra-specific divergence of nrDNA ITS and ycJfl (0.022-0.106 and 0.017-0.106) were obviously higher than the inter-specific divergence (0-0.012 and 0-0.015), and four species of Bletilla were also accurately distinguished in NJ trees. Whereas, there was no Barcoding Gap on LFY homologous gene intron 2, thus it cannot effectively identify species of Bletilla. Using NJ tree of nrDNA ITS and ycfl gene, powdery medicine and the adulterants of Bletilla were successfully unidentified. In conclusion, nrDNA ITS and ycfl can be used as a potential DNA barcoding to identify the medicinal plants in Bletilla and its adulterants. There were only three basic differences on nrDNA ITS between "Jujing baiji" and Bletilla striata of Lu'an in Anhui province, and two basic differences in ycfl. Based on morphological and molecular data, "Jujing baiji" could be recognized as the species of Bletilla striata.
Base Sequence ; DNA Barcoding, Taxonomic ; DNA, Plant ; genetics ; DNA, Ribosomal Spacer ; genetics ; Orchidaceae ; classification ; Plants, Medicinal ; classification

OBJECTIVETo investigate radiation protection and possible mechanisms of low intensity microwave on gamma-ray exposed mice.

METHODS96 healthy Kunming mice were randomly divided into the following four groups: normal control, microwave (120 microW/cm(2), 900 MHz), gamma-ray irradiation (5 Gy), combined exposure of microwave and gamma-ray (120 microW/cm(2) + 5 Gy). The microwave group and combined group were exposed to 120 microW/cm(2) microwave firstly, 1 h/d, for 14 days. Then the ionization and combined group were exposed to 5 Gy (60)Co gamma-ray irradiation on the 15th day. Animals were sacrificed on the third, 6th, 9th and 12th day after irradiation. The sternum and spleen paraffin section were produced, and the histological changes were observed. Apoptosis rate of mice splenic cells in each group was examined by flow cytometry, and serum concentration of antioxidant and lipid peroxide was detected at the same time.

RESULTSBone marrow was obviously injured either by radiation or microwave exposure, characterized by undergoing four-phase lesions, namely apoptosis-necrosis, void, regeneration and recovery phase. Compared with the gamma-ray group, the pathological changes in combined group were slighter and the recovery was quicker. The pathological injuries of spleen were similar to that of bone marrow. Injuries in the combined group were slighter than gamma-ray group. It showed that apoptosis rate of splenic cells in combined group was significantly lower on the 6th and 9th day after gamma-ray radiation (23.02% +/- 15.18%, 25.37% +/- 11.62% respectively) from FCM results. Assays of oxidative damages suggested that serum superoxide dismutase (SOD) level in combined group increased while lipid peroxide level decreased significantly (P < 0.05).

CONCLUSIONLow intensity microwave may exert protection effects on injuries induced by ionizing radiation. The underlying mechanisms might be related with suppression on the hematopoietic cells apoptosis induced by gamma-ray radiation, inhibition of oxidative damages, and thus enhanced reconstruction of the hematopoietic system.

Animals ; Apoptosis ; radiation effects ; Dose-Response Relationship, Radiation ; Gamma Rays ; adverse effects ; Male ; Mice ; Microwaves ; Radiation Protection

OBJECTIVETo observe the outcome of percutaneous balloon mitral valvuloplasty (PBMV) in patients with rheumatic mitral valve stenosis.

METHODSFrom April 1992 to November 2008, 1768 patients underwent PBMV in our hospital.Clinical and echocardiographic follow up data were analyzed in 426 patients from April 1992 to August 1998. Left atrial pressure and the mitral valve gradient (MVG) were measured before and immediately after PBMV in all patients.

RESULTSPBMV was successful in 1748 out of 1768 patients (98.86%). Left atrial pressure decreased from (38 +/- 7) mm Hg (1 mm Hg = 0.133 kPa) to (12 +/- 4) mm Hg (P < 0.001), MVG decreased from (28 +/- 6) mm Hg to (8 +/- 3) mm Hg (P < 0.001) and the area of the mitral valve increased from (0.98 +/- 0.26) cm(2) to (1.97 +/- 0.39) cm(2) (P < 0.001) post PBMV. The main complications included death (n = 2), acute pericardial effusion (n = 1), severe mitral regurgitation (n = 12), cerebral embolism (n = 2) and pulmonary edema (n = 1). Ten years follow up was finished in 426 patients and 288 patients (67.6%) were still in NYHA class Ior II without mitral valve replace operation or repeated PBMV, restenosis was evidenced in 140 patients (33.3%) and 31 patients dead (7.5%).

CONCLUSIONPBMV was an effective therapy option for patients with rheumatic mitral valve stenosis.

Catheterization ; adverse effects ; Echocardiography ; Follow-Up Studies ; Humans ; Mitral Valve Stenosis ; therapy ; Rheumatic Heart Disease ; therapy ; Treatment Outcome

OBJECTIVETo investigate the effect of purple sweet potato on lipid metabolism and oxidative stress in hyperlipidemic rats.

METHODSForty male SD rats were randomly divided into 4 groups: normal control group, high-fat control group, high purple sweet potato groups, low purple sweet potato group. The rats were fed with different diets for 6w respectively.

RESULTSSerum TC, TG levels were significantly lower in high dosage group than in high-fat control group; while only serum TG was significantly lower in low dosage group than in high-fat control group, these changes started at the third week and lasted to the end of experiment. Serum LDL-C and AI levels were significantly lower in high and low dosage group than in high-fat control group, whereas, serum HDL-C was significantly higher than that in high-fat control group at w3 and lasted to the end of experiment. Serum SOD was significantly higher in high and low dosage group than in high-fat control group, whereas, serum MDA was significantly lower than that in high-fat control group at w6.

CONCLUSIONPurple sweet potato can decrease serum lipids and reduce hepatic oxidative stress in hyperlipidemic rats.

Animals ; Disease Models, Animal ; Hyperlipidemias ; metabolism ; Ipomoea batatas ; Lipid Metabolism ; Lipids ; blood ; Male ; Oxidative Stress ; drug effects ; Rats ; Rats, Sprague-Dawley