The traditional view of bacterial life cycle consists of four phases,namely,lag phase,exponential or logarithmic phase,stationary phase and death phase.Although the standard textbook description of the bacterial life cycle has been useful,might not always provide us the whole visage of bacteria growth process.Recently,it has demonstrated that bacterial life cycle is expanded to five phases.It is a significant different growth phase after death phase:long-term stationary phase,which may be more akin to the nature environment in which microorganisms exist.Microbial cells survive due to mutating,and forming growth advantage during stationary phase (GASP) phenotype in this phase.It is very important for further study the microorganisms in this phase.

AIM:To investigate whether cigarette smoke(CS)promotes the expression of endoplasmic reticu-lum-associated apoptosis protein CCAAT/enhancer-binding protein homologous protein(CHOP)in rat lung tissues. METHODS:Adult male Wistar rats(n=40)were randomly divided into 4 groups with 10 rats in each group: control group,CS-2 group(exposed to CS for 2 months),CS-4 group(exposed to CS for 4 months)and ex-smoking(Ex-S)group (exposed to CS for 4 months and then quit smoking for 1 month).The percentage of forced expiratory volume in 0.3 second to forced vital capacity(FEV0.3/FVC)and peak expiratory flow(PEF)were measured.TUNEL assay was used to detect the apoptotic cells.In situ hybridization and RT-PCR were used to determine the mRNA expression of CHOP.The methods of immunohistochemistry and Western blot were used to determine the protein expression of CHOP.Western blot was also used to determine the protein levels of protein kinase R-like endoplasmic reticulum kinase(PERK),p-PERK,eukaryotic initiation factor(eIF)2αand p-eIF2α.RESULTS:The pulmonary function greatly decreased in the rats exposed to CS for 2 months in comparison with control group(P<0.05),markedly decreased in the rats exposed to CS for 4 months as com-pared with the rats after exposure to CS for 2 months(P<0.05),and was improved little in ex-smoking rats(P>0.05). The structural destruction of the lung was observed in the rats exposed to CS for 2 months,and more obvious changes were found in the rats exposed to CS for 4 months.However,the structural destruction of the lung remained obvious in ex-smok-ing rats.The apoptotic cells were markedly increased in the rats exposed to CS for 2 months and were even more in the rats exposed to CS for 4 months.The apoptotic cells were alveolar epithelial cell I(ACE I),ACE II,vascular endothelial cells and bronchial epithelial cells.The protein levels of p-PERK,p-eIF2αand CHOP were remarkably increased in the rats af-ter exposure to CS for 2 months compared with the control rats(P<0.05),significantly elevated in the rats exposed to CS for 4 months compared with the rats exposed to CS for 2 months(P<0.05),and slightly decreased in ex-smoking rats in comparison with the rats after exposure to CS for 4 months(P>0.05).The total protein levels of PERK and eIF2αdid not change between the control rats and those exposed to CS.CONCLUSION: CS promotes the development of chronic ob-structive pulmonary disease(COPD)by inducing the expression of endoplasmic reticulum-associated apoptosis protein CHOP via PERK/eIF2α/CHOP signaling pathway.

AIM: To examine the expression of gap junction protein family genes, including thirteen independent genes, in normal human nasophryngeal epithelial tissue and to conjecture the possible roles of gap junction proteins in nasopharyngeal carcinoma. METHODS: With synthesized primers, the expression of thirteen genes encoding different gap junction proteins in human normal nasopharyngeal epithelial tissue were detected by RT-PCR. RESULTS: In 18 samples of normal human nasopharyngeal epithelial tissue, 16 of them were found the expression of Cx 30, 31 1, 17 of them were found the expression of Cx 37 and Cx 43, and Cx 40 expression were detected in 15 samples. Also the expression of Cx 26, 31, 32, 36, 45, 46, 46 6, 50 were detected respectively in 10, 11, 9, 1, 9, 0, 1,3 samples of the 18 cases. CONCLUSION: In normal human nasopharyngeal tissue, Cx 30, 31, 31 1,37, 40, 43 might be the key gap junction proteins.

OBJECTIVETo observe the killing effect of Herceptin and adriamycin sequentially applied on breast cancer cell line in vitro.

METHODSBT-474 human breast cancer cells in exponential growth phase were treated with Herceptin alone, adriamycin alone and their sequential administration (Herceptin before adriamycin and vice versa), respectively. Under optical microscope, the morphological changes of the cells were observed before and after drug administration. The expression rate and mean fluorescence intensity (MFI) of HER-2/neu and cell death rate were detected by flow cytometry.

RESULTSMicroscopically, the cells treated with different protocols all exhibited such changes as darkening and increase of cellular debris with irregular cell morphology. Flow cytometry revealed no significant difference in the expression rate of HER-2/neu in each group before and after treatment, but the MFI of HER-2/neu and death rate of the treated cells were significant different from those of the control group (P<0.05). The cell death rate of Herceptin-pretreated cells was significantly higher than that of adriamycin-pretreated ones (P<0.05).

CONCLUSIONHerceptin pretreatment enhances the killing effect of adriamycin on breast cancer cell line BT-474, which provides experimental evidence for designing clinical sequential biochemotherapy of breast cancer.

Antibiotics, Antineoplastic ; pharmacology ; Antibodies, Monoclonal ; pharmacology ; Antibodies, Monoclonal, Humanized ; Antineoplastic Agents ; pharmacology ; Breast Neoplasms ; metabolism ; pathology ; Cell Death ; drug effects ; Cell Line, Tumor ; Doxorubicin ; pharmacology ; Drug Synergism ; Female ; Flow Cytometry ; Humans ; Receptor, ErbB-2 ; biosynthesis ; Trastuzumab

Objective　To ascertain the natural infection rate of hemorrhagic fever with renal syndrome virus (HFRSV) among its hosts and the type of the natural foci for providing some baseline data for the immigrant health and epidemic prevention of the Three-Gorge region. Methods　Epidemiological survey on the field was performed including epidemiological data collection, ecology of rodents and pathogen detection. HFRS virus antigen of hosts were detected by the direct immunofluorescent assay (DIFA) technique and determination of HFRSV-RNA by ISH were carried out from HFRSV-Ag-positive animals. Results　HFRSV-Ag-positive animals were found in 5 migration areas ie Baitao Town of Fuling Section, Wansheng Village of Fengjie County and Dachang Town of Wushan County. The positive hosts were as follows, Rattus Norvegicus, Apodemus agrarius, Anourusurex squamipes, Mus musculus and Rattus flavipectus. The positive rate of HFRSV in the mice of 5 migration areas were 19.4%, 17.0%, 14.0%, 13.7%, and 8.5% respectively. The results showed that the lung tissues of some hosts in all five migration areas were HFRSV-RNA-positive. Baitao Town and Peishi Town were attributed to mixture type epidemic areas while. Kangle Town, Wansheng Village and Dachang Town were domestic rats type epidemic areas. Conclusion　This study shows that the five migration areas are natural epidemic foci of HFRS. It is predicted that maximum risk of HFRS breakout or epidemic may take place after the completion of the San Xia Reservoir(the Three-Gorges Reservoir), which results from rodent moving toward higher land. Therefore, deratization and preventive measures for rat are important in migration areas.

BACKGROUNDDuring scanning of the right hypochondrium and right intercostal regions with an ultrasonic transducer, several ultrasonic images of oblique sections are obtained. It is still a challenge for ultrasonography to divide these non-conventional sections into an accurate hepatic segmentation pattern. The aim of this research was to investigate the value of the virtual hepatic segment model (VHSM) in assisting the ultrasonic localization of space-occupying hepatic lesions.

METHODSVHSM was constructed via 3D reconstruction according to the first Chinese visible human dataset. Preoperative ultrasonography, contrast-enhanced CT scan and VHSM techniques were performed in 100 patients with space-occupying focal lesions in the liver parenchyma for segmental localization. The results of these three techniques were compared with the operative findings.

RESULTSVHSM was successfully detected on 2D sectional images by 3D reconstruction through surface rendering and volume rendering. The model could simulate ultrasonic directions to conduct a virtual dissection on any section plane, and fine liver segmentation could be displayed in any virtual plane. In 100 patients, there were 112 liver space-occupying focal lesions distributed in 148 liver segmentations. Regarding the positioning accuracies for lesions of different sizes and the lesion segmental distribution accuracies estimated using the three methods mentioned above, ultrasonography exhibited a significantly lower accuracy than VHSM for the segmental localization of lesions (P < 0.05), and contrast-enhanced CT was not significantly different from ultrasonography plus VHSM (P > 0.05).

CONCLUSIONVHSM increased the accuracy of ultrasonic localization of space-occupying hepatic lesions, particularly in hepatic hypovascular regions.

Computer Simulation ; Humans ; Liver ; diagnostic imaging ; pathology ; Radiography ; Ultrasonography

OBJECTIVEThe purpose was to analyze the effects of three sterilization methods (dry heat sterilization, steam sterilization, chemical sterilization) on the corrosion of dental fissure burs.

METHODS100 dental fissure burs were distributed to 10 groups. One was control, the burs in the other 9 groups were treated by dry heat sterilization, steam sterilization, chemical sterilization with 5, 10, 15 cycles respectively. Weight method, scanning electron microscope, micro-hardness measurement were used to analyze the corrosion of dental fissure burs.

RESULTSThe fissure burs gained their weight with cycles of sterilization. 5, 10, 15 cycles of dry heat sterilization, 10, 15 cycles of steam sterilization and 15 cycles of chemical sterilization, the weight of fissure burs were significantly increased (P < 0.05). Scanning electron microscope showed differences on the surfaces of dental fissure burs among the three sterilization groups. After sterilization, spot or partial erosion were seen on the surface of the burs. The steam sterilization groups showed the most evident changes, followed by chemical sterilization groups and dry heat sterilization groups. X-ray energy spectrometer showed the steam sterilization groups had the largest percentage of W, followed by dry heat sterilization groups, chemical sterilization groups and control group. Fe had the opposite trends. Micro-hardness reduced after sterilization. The reduction was most clear in steam sterilization group, followed by chemical sterilization and dry heat sterilization ( P< 0.05). The difference between 5 and 10 times of steam sterilization and 5, 10, 15 times of chemical sterilization were significant difference (P < 0.05). There was no significant difference between 5, 10, 15 times of dry heat sterilization (P > 0.05).

CONCLUSIONThe corrosion is most severe in steamsterilization group, followed by chemical sterilization, dry heat sterilization. Dry heat sterilization shows less corrosion.

Corrosion ; Dental Fissures ; Dental High-Speed Equipment ; Dental Instruments ; Steam ; Sterilization

OBJECTIVETo study the effects of diallyl disulfide (DADS) on apoptosis of human leukemia K562 cells and possible mechanisms.

METHODSThe morphologic changes of leukemia K562 cells after DADS treatment were observed by Hoechst 33258 staining. Cell apoptosis rates after different concentrations and different durations of DADS treatment were determined by flow cytometry. Fas, FasL and caspase-8 mRNA expression was estimated by reverse transcription-polymerase chain reaction (RT-PCR) 48 hrs after DADS treatment.

RESULTSThe characteristics of apoptosis in K562 cells induced by DADS were observed. After 24 hrs of DADS treatment, the apoptosis rate of K562 cells increased from (11.60 ± 0.83)% at the concentration of 10 mg/L to (37.94 ± 0.87)% at the concentration of 40 mg/L. The apoptosis rate of K562 cells increased after 40 mg/L DADS with the increasing time from (37.94 ± 0.87)% (24 hrs) to (47.02 ± 0.66)% (72 hrs). Expression of Fas and caspase-8 mRNA increased, while FasL mRNA expression decreased significantly 48 hrs after DADS treatment compared with the control group (P<0.05).

CONCLUSIONSDADS can induce apoptosis of human leukemia K562 cells in a time- and concentration-dependent manner, possibly through increasing Fas and caspase-8 expression and decreasing FasL expression.

Allyl Compounds ; pharmacology ; Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; Bisbenzimidazole ; Caspase 8 ; genetics ; Disulfides ; pharmacology ; Fas Ligand Protein ; genetics ; Flow Cytometry ; Humans ; K562 Cells ; RNA, Messenger ; analysis ; fas Receptor ; genetics

OBJECTIVETo study the expression of lung Krüppel-like transcription factor (KLF2/LKLF) in lung tissues of rats with chronic obstructive pulmonary disease (COPD) and the relationship between KLF2 and NF-E2-related factor 2 (Nrf2), and make further explore the effects of KLF2 on the expression of gamma-glutamylcysteine synthetase (gamma-GCS).

METHODSTwenty-two male SD rats were randomly divided into a COPD group (n = 10) and a normal control group (n = 11). The rat model of COPD established by cigarette smoking and intratracheal instillation of lipopolysaccharide (LPS), and lung tissues were obtained. The expressions of KLF2, Nrf2, gamma-GCS mRNA and protein in lung tissues were measured by immunohistochemistry (IHC), Western blot, in situ hybridization (ISH) and reverse transcription-polymerase chain reaction (RT-PCR). To explore the relationship between KLF2 and Nrf2 protein,we utilize the method of co-immunoprecipitation (CO-IP).

RESULTSIHC and Western blot showed that protein expressions of KLF2, Nrf2, gamma-GCS were higher in the lung tissues from rats with COPD than those in the control groups (all P < 0.05). The levels of KLF2, gamma-GCS mRNA were markedly increased in the COPD group (all P < 0.01) while Nrf2 mRNA expression in COPD group had no significant difference with that in control group ( P > 0.05). CO-IP result showed that KLF2 were obviously present in immunoprecipitates of Nrf2 (P < 0.01) . Linear correlation analysis showed that the level of KLF2 protein was positively correlated with the level of Nrf2 protein (P < 0.05), and KLF2, Nrf2 proteins were positively correlated with gamma-GCS mRNA and protein (all P < 0.05).

CONCLUSIONThe expression of KLF2 is significantly up-regulated in COPD, which maybe up-regulate gamma-GCS mRNA expression by increasing Nrf2 expression and nuclear translocation against oxidative stress.

Animals ; Dipeptides ; metabolism ; Kruppel-Like Transcription Factors ; metabolism ; Lung ; pathology ; physiopathology ; Male ; NF-E2-Related Factor 2 ; metabolism ; Pulmonary Disease, Chronic Obstructive ; metabolism ; pathology ; physiopathology ; Rats ; Rats, Sprague-Dawley

To study the effect of Siwu decoction on the function and expression of P-glycoprotein (P-gp) in Caco-2 cells. The Real-time quantitative poly-merase chain reaction (Q-PCR) was used to analyze the mRNA expression of MDR1 gene in Caco-2 cells. Flow cytometer was used to study the effect of Siwu decoction on the uptake of Rhodamine 123 in Caco-2 cells, in order to evaluate the efflux function of P-gp. Western blotting method was used to detect the effect of Siwu decoction on the P-gp protein expression of Caco-2 cells. Compared with the blank control group, after Caco-2 incubation with Siwu decoction at concentrations of 3.3, 5.0, 10.0 g x L(-1) for 24, 48, 72 h, the mRNA expression of MDR1 was up-regulated, suggesting the effect of Siwu decoction in inducing the expression of MDR1. After the administration with Siwu decoction in Caco-2 cells for 48 h, the uptake of Rhodamine 123 in Caco-2 cells decreased by respectively 16.6%, 22.1% (P < 0.05) and 45.4% (P < 0.01), indicating that the long-term administration of Siwu decoction can enhance the P-gp efflux function of Caco-2 cells. After the incubation of Caco-2 cells with Siwu decoction for 48 h, the P-gp protein expression on Caco-2 cell emebranes, demonstrating the effect of Siwu decoction in inducing the protein expression of P-gp.
ATP Binding Cassette Transporter, Sub-Family B ; genetics ; metabolism ; ATP-Binding Cassette, Sub-Family B, Member 1 ; genetics ; metabolism ; Caco-2 Cells ; Drugs, Chinese Herbal ; pharmacology ; Humans ; Up-Regulation ; drug effects