Lentivirus-mediated overexpression of suppressor of cytokine signaling-3 reduces neutrophilic airway inflammation by suppressing T-helper 17 responses in mice with chronic Pseudomonas aeruginosa lung infections.

The aim of the present study was to explore the effect of overexpressed suppressor of cytokine signaling­3 (SOCS3) on T-helper (Th)17 cell responses and neutrophilic airway inflammation in mice with chronic Pseudomonas aeruginosa (PA) infections. SOCS3 expression was enhanced via the administration of tail vein injections of therapeutic lentivirus in mice with chronic PA lung infections. SOCS3 expression in the blood and lung tissue was assessed using reverse transcription­quantitative polymerase chain reaction (RT­qPCR) and western blot analysis. Total and differential cell numbers and myeloperoxidase levels in the bronchoalveolar lavage (BAL) fluid were assessed, as well as the number of bacterial colonies in the lungs. Histological analysis of lung tissue was performed using hematoxylin and eosin staining and phosphorylated­signal transducer and activator of transcription­3 (p­STAT3) expression was measured by western blot analysis and immunohistochemistry. The expression of STAT3 mRNA and retinoid­related orphan receptor (ROR)γt were measured by RT­qPCR. The percentage of interleukin (IL)­17+ cells among cluster of differentiation (CD)4+ cells was calculated using flow cytometry and levels of IL­17A and IL­6 were assessed by ELISA. The expression of SOCS3 was significantly increased in CD4+ T cells following lentivirus injection and the inflammation of neutrophilic airways was notably ameliorated. Enhanced SOCS3 expression was associated with a significant decrease in the expression of p­STAT3 and RORγt in CD4+ T cells. Additionally, the percentage of IL­17+ cells among CD4+ T cells and the IL­17 contents in the BAL fluid were significantly decreased. Lentivirus­mediated overexpression of SOCS3 was revealed to ameliorate neutrophilic airway inflammation by inhibiting pulmonary Th17 responses in mice with chronic PA lung infections.

Interleukin-17A promotes the formation of inflammation in the lung tissues of rats with pulmonary fibrosis.

The aim of the present study was to investigate the effects of interleukin (IL)-17A in a rat model of pulmonary fibrosis. In total, 20 female Wistar rats were randomly divided into a normal saline (NS group) and a bleomycin group (BLM group). The BLM group rats were intratracheally instilled with BLM, while the NS group rats were intratracheally instilled with saline. In each group, half the rats were sacrificed at day 7 and day 28, respectively, following intratracheal instillation. Subsequently, hematoxylin and eosin and Masson's trichrome staining were performed to observe the pathological changes in the lung tissue, while the expression of IL-17A in the lung tissue was detected by immunohistochemistry. In addition, the bronchoalveolar lavage fluid (BALF) was collected and divided into two sections. One section was used for cell counting and classification, and an ELISA was performed to detect the concentration of IL-17A in the BALF. The additional section was used to separate, purify and cultivate alveolar macrophages (AMs). The concentration of IL-17A in the cultivating supernatant was detected by ELISA, and the mRNA expression levels of IL-17A in the AMs were detected using reverse transcription-polymerase chain reaction (RT-PCR). The results revealed that a considerable number of inflammatory cells had infiltrated into the alveolar cavity in the BLM group at day 7, and less alveolitis and more serious fibrosis were observed at day 28, as compared with the NS group. Furthermore, when compared with the NS group, the protein expression levels of IL-17A in the lung tissue were markedly higher in the BLM group at days 7 and 28 (higher at day 7; P<0.05). In addition, the total number of BALF cells in the BLM group was clearly higher at day 7 when compared with the NS group (P<0.05), although a normal level was re-established by day 28. The level of IL-17A in the BALF increased significantly at days 7 and 28 in the BLM group; however, when compared with the level at day 7, the concentration had decreased at day 28. When compared with the NS group, the protein expression levels of IL-17A in the BLM group were notably higher after 12, 24 and 48 h. In addition, the results of the RT-PCR assay revealed that the mRNA expression levels of IL-17A increased significantly at days 7 and 28 in the BLM group when compared with the NS group (P<0.05). Therefore, IL-17A was demonstrated to promote the development of pulmonary inflammation, which may be involved in the development of pulmonary fibrosis.

5-Fluorouracil and interleukin-2 immunochemotherapy enhances immunogenicity of non-small cell lung cancer A549 cells through upregulation of NKG2D ligands.

BACKGROUND: The aim of this study was to investigate the anti-cancer effects and mechanisms of immunochemotherapy of 5-fluorouracil (5-FU) and interleukin-2 (IL-2) on non-small cell lung cancer (NSCLC) A549 cells. MATERIALS AND METHODS: In order to detect whether 5-FU+IL-2 could effectively inhibit tumor growth in vivo, we established an A549-bearing nude mouse model. The cytotoxicity of natural killer (NK) cells was evaluated using a standard chromium release assay. To evaluate the relevance of NK cells in 5-FU+IL-2- mediated tumor inhibitory effects, we depleted NK cells in A549-bearing mice by injecting anti-asialo-GM-1 antibodies. Effects of 5-FU+IL-2 on the expression and promoter activity of NKG2D ligands (MICA/MICB) in A549 cells in vitro were also assessed. RESULTS: In A549-bearing nude mice, combination therapy significantly inhibited tumor growth in comparison with monotherapy with 5-FU or IL-2 and enhanced the recognition and lysis of tumor cells by NK cells. Further study of mechanisms showed that NK cells played a vital role in the anticancer immune response of 5-FU+IL-2 immunochemotherapy. In addition, the combination therapy synergistically stimulated the expression and promoter activity of MICA/MICB. CONCLUSIONS: 5-FU and IL-2 immunochemotherapy significantly inhibited tumor growth and activated NK cytotoxicity in vivo, and these effects were partly impaired after depleting NK cells in tumor-bearing mice. Combination treatment of 5-FU and IL-2 upregulated the expression and the promoter activity of MICA/MICB in A549 cells, which enhanced the recognition of A549 cells by NK cells. All of the data indicated that immunochemotherapy of 5-FU and IL-2 may provide a new treatment option for patients with lung cancer.

Extracellular matrix-coating pedicle screws conduct and induce osteogenesis.

BACKGROUND: The purpose of the present study was to study the effects of the extracellular matrix-coating pedicle screws on the conduction and induction of bone formation in young sheep. METHODS: Pedicle screws [coated with collagen/chondroitin sulfate (coll/CS), hydroxyapatite (HA), and coll/CS/HA or uncoated] were randomly implanted into the L2-L5 pedicles of sheep. In the first stage, a static experiment was performed. In the second stage, a loading test was performed by implanting connecting rods. After 3 months, the lumbar vertebrae with the screws were removed and examined by micro-CT, histological, and biomechanical analyses. RESULTS: Under non-loading conditions, there is bone formation around the surfaces of coated screws. Bone formation on the surface of the coll/CS/HA coating of pedicle screws was the highest. In terms of the trabecular bone morphology parameters of the region of interest around the surface of the pedicle screws, those associated with coll/CS/HA coatings were highest under non-loading conditions, the pullout strength of the coll-/CS-/HA-coated screws was the highest and that of the uncoated screws was minimal. Under loading conditions, the maximum pullout strength of each group of pedicle screws was less than that of the pedicle screws in the non-loading state. CONCLUSIONS: Under non-loading conditions, the organic and inorganic components of the titanium pedicle screw coatings can conduct or induce bone formation around the surface of the screws. The ability of the coll/CS/HA coating to induce bone formation was the strongest. Under loading conditions, a large amount of connective tissue formed around the surface of the screws in each group.

Zinc finger X-chromosomal protein promotes growth and tumorigenesis in human osteosarcoma cells.

OBJECTIVE: To investigate the role of Zinc finger X-chromosomal protein (ZFX) in oncogenesis of Osteosarcoma tumor. METHODS: Here, we first conducted an expression analysis of ZFX in Osteosarcoma cell lines. Then, we constructed ZFX-specific small interfering RNA (siRNA)-lentiviral vector that is capable of effectively inhibiting the expression of ZFX gene in human Osteosarcoma Saos-2 cells, and investigated systemically the impacts of ZFX silence on the growth and invasive ability of the cancer cells in vitro. Furthermore, we determined the effects of ZFX knockdown on the cell cycle distribution and apoptosis of Saos-2 cells. RESULTS: We found that ZFX inhibition resulted in significantly impaired proliferation and colony formation as well as mitigated invasiveness of Saos-2 cells. Importantly, si-ZFX infected cells exhibited a greater portion of cells at G1 phase, but a minor portion of S and G2/M phase cells. Moreover, a greater portion of sub-G1 apoptotic cells was observed in si-ZFX infected cells. CONCLUSIONS: These results strongly suggest that ZFX is a novel proliferation regulator that promotes growth of Osteosarcoma cells, and downregulation of ZFX expression induces growth suppression of Saos-2 cells via arrested G0/G1 phase cell cycle and apoptosis pathways, thereby indicating that ZFX may serve as a new molecular target for Osteosarcoma tumor therapy.

Induction of thoracic aortic remodeling by endothelial-specific deletion of microRNA-21 in mice.

MicroRNAs (miRs) are known to have an important role in modulating vascular biology. MiR21 was found to be involved in the pathogenesis of proliferative vascular disease. The role of miR21 in endothelial cells (ECs) has well studied in vitro, but the study in vivo remains to be elucidated. In this study, miR21 endothelial-specific knockout mice were generated by Cre/LoxP system. Compared with wild-type mice, the miR21 deletion in ECs resulted in structural and functional remodeling of aorta significantly, such as diastolic pressure dropping, maximal tension depression, endothelium-dependent relaxation impairment, an increase of opening angles and wall-thickness/inner diameter ratio, and compliance decrease, in the miR21 endothelial-specific knockout mice. Furthermore, the miR21 deletion in ECs induced down-regulation of collagen I, collagen III and elastin mRNA and proteins, as well as up-regulation of Smad7 and down-regulation of Smad2/5 in the aorta of miR21 endothelial-specific knockout mice. CTGF and downstream MMP/TIMP changes were also identified to mediate vascular remodeling. The results showed that miR21 is identified as a critical molecule to modulate vascular remodeling, which will help to understand the role of miR21 in vascular biology and the pathogenesis of vascular diseases.

SMC1A knockdown induces growth suppression of human lung adenocarcinoma cells through G1/S cell cycle phase arrest and apoptosis pathways in vitro.

SMC1A (structural maintenance of chromosomes 1A), which encodes a structural subunit of the cohesin protein complex, is necessary for the process of sister chromatid cohesion during the cell cycle. Mutation and deregulation of SMC1A are highly relevant to diverse human diseases, including Cornelia de Lange syndrome and malignant carcinomas. In order to further investigate the role of SMC1A in the oncogenesis of lung cancer, SMC1A-specific short hairpin RNA (shRNA)-expressing lentivirus (Lv-shSMC1A) was constructed and used to infect A549 and H1299 cells. SMC1A mRNA and protein expression levels were downregulated in A549 and H1299 cells as demonstrated by real-time PCR and western blot assays. We found that SMC1A inhibition resulted in significantly impaired proliferation and colony formation as well as reduced invasiveness of tumor cells. Notably, Lv-shSMC1A-infected cancer cells exhibited a greater proportion of cells in the G0/G1 phase, but a lower proportion of S phase cells, compared to the parent or Lv-shCon infected cancer cells. Moreover, a greater proportion of sub-G1 apoptotic cells was observed in Lv-shSMC1A-infected cells. These results suggest that SMC1A is a novel proliferation regulator that promotes the growth of lung cancer cells, and that down-regulation of SMC1A expression induces growth suppression of A549 and H1299 cells via G1/S cell cycle phase arrest and apoptosis pathways. Therefore, SMC1A may serve as a new molecular target for lung cancer therapy.

Age-related differences in microstructure, density and biomechanics of vertebral cancellous bone of Chinese males.

The conventional lumbar separation was performed by removing soft tissue, subsidiary structures and leaving only the vertebral body. The vertebral body was cut into two halves along the median sagittal plane, keeping the upper and lower end plates of each half, which were subsequently used for biomechanical, morphological and density experiments. From the age of 20-29 to 30-39 years, both the horizontal trabecular thickness (Tb.Th) and vertical Tb.Th decreased; the horizontal and vertical Tb.Sp increased; the plate-like trabecular Tb.Th decreased; the apparent density and volume ratio decreased; and the elastic modulus and the ultimate stress decreased; with all changes being statistically significant (p < 0.01). Similar trends were obtained from ages 40-49 to 50-59, although the changes were not significant (p > 0.05), except for the reduction in ultimate stress (p < 0.05). With aging, the collagen cross-linking capacity declined; the thicknesses of the collagen fibrils were variable, ranging from almost the same to loose, sparse or disordered thickness; and the finer collagen fibrils between the thick filaments were disorganized. In males aged from 20 to 59 years old, the horizontal and vertical Tb.Th and the plate-like Tb.Th of the vertebral body decreased, while the horizontal and vertical Tb.Sp increased. Additionally, the density, elastic modulus and the ultimate stress of the cancellous bone decreased with age. Thus, the associated changes of bone microstructure, density and biomechanics with age may lead to an increased risk of osteoporosis and fracture.

Zinc finger X-chromosomal protein (ZFX) promotes solid agar colony growth of osteosarcoma cells.

Zinc finger X-chromosomal protein (ZFX) is a member of the zinc finger family of proteins. The importance of ZFX in several cancer types, including prostate cancer, laryngeal squamous cell carcinoma, and glioma, has been addressed. However, the role of ZFX in human osteosarcoma remains unknown. Here we investigated the phenotype of ZFX knockdown on cell proliferation and in vitro tumorigenesis using lentivirus-mediated loss-of-function strategy. The results demonstrated that the proliferation and colony formation ability of human osteosarcoma Saos-2 and MG63 cells was impaired by ZFX small interfering RNA (siRNA)-expressing lentivirus. Moreover, loss of ZFX led to G0/G1 phase cell cycle arrest and a significant increase of cells in the sub-G1 fraction, indicating that ZFX functions as an oncogene in the malignant proliferation process in osteosarcoma. Furthermore, ZFX siRNA may have an antitumorigenic effect on osteosarcoma cells. Our findings hold important significance for RNA interference-mediated cancer gene therapy for human osteosarcoma.

[The clinical efficacy and safety of intravenous cefmetazole in treatment of 1,522 patients with aspiration pneumonia].

OBJECTIVE: To evaluate the efficacy and safety of intravenous cefmetazole in the treatment of patients with aspiration pneumonia. METHODS: A multicenter, prospective and open-labeled trial was conducted. A total of 1522 patients were enrolled at the beginning, and only 1324 were evaluated at the endpoint. The duration of treatment was 7 - 14 days. During the treatment and follow-up periods, we recorded any unexpected symptoms and abnormal laboratory tests. At last, we evaluated its efficacy and safety. RESULTS: The total effective rate of cefmetazole was 79.8%(1056/1324). The total bacterial eradication rate was 75.0% (342/456). The bacterial eradication rates of Klebsiella pneumonia, Escherichia, Staphylococcus aureus and anaerobic bacteria were 78.2% (97/124), 80.8% (80/99), 89.0% (81/91), 9/11, respectively. CONCLUSIONS: Cefmetazole is effective and safe in the treatment of aspiration pneumonia.

MED19 promotes proliferation and tumorigenesis of lung cancer.

MED19 is a subunit of Mediator that is an essential component of RNA polymerase II-mediated transcription machinery. High expression levels of MED19 were examined in human lung adenocarcinoma tissues by immunohistochemical assay. MED19-specific short hairpin RNA (shRNA) expressing lentivirus was constructed and infected lung cancer cell line A549. MED19 mRNA and protein expression levels were downregulated in A549 cells as evidenced by real-time PCR and western blot assays. Importantly, MED19 inhibition resulted in impaired proliferation and colony formation, and induced accumulation of G1-phase cells and mitigated invasiveness of cells. More importantly, downregulation of MED19 expression reduced the tumorigenicity of A549 cells in vivo. It was suggested that MED19 is a novel proliferation regulator that promotes growth of lung cancer cells, thereby indicating that MED19 may serve as a new molecular target for lung cancer therapy.

In vivo study of extracellular matrix coating enhancing fixation of the pedicle screw-bone's interface.

BACKGROUND: Based on in vivo research on the effect of the coating of the extracellular matrix composition of pedicle screws on the conduction and induction of bone formation in young sheep, the aim of this study was to investigate the application of coated pedicle screws in sheep with scoliosis whose spines are under constant development. METHODS: Four groups of pedicle screws were randomly implanted into bilateral L2-L5 pedicles of 2.5- to 3-month-old sheep. A static experiment was performed on one side and a loading test was performed on the other side by implanting connecting rods at the L2-L3 and L4-L5 segments. The changes in the force on the coated screws and the combination of the surface of the coated screws with the surrounding bone in the growth process of young sheep's spines with aging were observed. After 3 months, the lumbar vertebrae with the screws were removed and examined by micro-CT, histological, and biomechanical analyses. RESULTS: Under nonloading conditions, there is bone formation around the surfaces of coated screws. The bone forming on the surface of collagen/chondroitin sulfate/hydroxyapatite coating of pedicle screws is the most, the one of the collagen/chondroitin sulfate coating and hydroxyapatite coating is followed, and no significant difference between the two groups. In terms of the trabecular bone morphology parameters of the region of interest around the surface of the pedicle screws, such as bone mineral content, bone mineral density, tissue mineral content, tissue bone mineral density, bone volume fraction, and connection density, those associated with collagen/chondroitin sulfate/hydroxyapatite coatings are largest and those unassociated with coatings are smallest. Under nonloading conditions, the pullout strength of the collagen/chondroitin sulfate/hydroxyapatite-coated screws was largest, and that of the uncoated screws was minimal (P < 0.01). Under loading conditions, the maximum pullout strength of each group of pedicle screws was less than that of the pedicle screws in the nonloading state (P < 0.01) with no significant difference between the groups (P > 0.05). CONCLUSIONS: Under nonloading conditions, the coatings of both organic and inorganic components of the extracellular matrix of titanium pedicle screws can conduct or induce bone formation around the surface of the screws. The ability of collagen/chondroitin sulfate/hydroxyapatite coatings to induce bone formation is stronger; under loading conditions, a large amount of connective tissue formed around the surfaces of the screws in each group. No significant differences were found between the groups.

[Artificial neural network parameters optimization software and its application in the design of sustained release tablets].

Artificial neural network (ANN) is a multi-objective optimization method that needs mathematic and statistic knowledge which restricts its application in the pharmaceutical research area. An artificial neural network parameters optimization software (ANNPOS) programmed by the Visual Basic language was developed to overcome this shortcoming. In the design of a sustained release formulation, the suitable parameters of ANN were estimated by the ANNPOS. And then the Matlab 5.0 Neural Network Toolbox was used to determine the optimal formulation. It showed that the ANNPOS reduced the complexity and difficulty in the ANN's application.

Change in mitochondrial membrane potential is the key mechanism in early warm hepatic ischemia-reperfusion injury.

The mitochondrion has been proposed to be both a target and a perpetuator of hepatic ischemia-reperfusion (IR) injury because of its reactive oxygen species (ROS) formation. Our hypothesis is that subcellular derangement in mitochondrial function is one of the earliest steps leading to the early IR-mediated loss of hepatocellular integrity. Under chloralhydrate anesthesia (36 mg/kg BW), Sprague-Dawley rats (n=7) were subjected to 40 min of warm hepatic lobular ischemia followed by 60 min reperfusion. Rats (n=7) without hepatic IR were used as controls. The fluorochromes rhodamine 123 and bisbenzimide were administered intravenously for observation of changes in mitochondrial membrane potential and hepatocellular viability, respectively. Intravital fluorescence microscopy (IVFM) was performed prior to ischemia and at 15, 45, and 60 min after reperfusion in the experimental group and at corresponding time points in the control group. A parallel relationship between mitochondrial membrane potential and cell viability as reflected in a concomitant reduction in nuclear and cytoplasmic fluorescence intensity during IR was demonstrated (r2=0.76, P<0.05). The diminution in fluorescence intensities also correlated significantly with the elevation in plasma transaminase activities (r2>0.90, P<0.05). Our data suggested that alteration in mitochondrial membrane potential is a critical subcellular event leading to hepatocellular damage in the early phase of hepatic IR injury.

Inhibition of STAT3 expression by siRNA suppresses growth and induces apoptosis in laryngeal cancer cells.

AIM: To determine the inhibitory effect of the synthetic STAT3 siRNA on the expression of STAT3 gene in human laryngeal cancer cell lines Hep2 and to investigate the effect of STAT3 siRNA on growth and apoptosis in Hep2 cells. METHODS: A pair of DNA templates coding siRNA against STAT3-mRNA was synthesized to reconstruct plasmid of pSilencer1.0-U6 siRNA-STAT3. Hep2 cells were transfected with RPMI-1640 media (untreated), plasmid (empty), and STAT3 siRNA, respectively. Northern blot and Western blot analysis of STAT3 and pTyr-STAT3 expression in Hep2 cells and Western blot analysis of Bcl-2 expression in the Hep2 cell was performed 72 h after transfection. MTT, flow cytometry, and AO/EB assay were used for determination of cells proliferation and apoptosis in Hep2 cells. RESULTS: pTyr-STAT3 was markedly expressed in untreated Hep2 cells and the vector-treated Hep2 cells, whereas pTyr-STAT3 expression was significantly reduced in STAT3 siRNA-transfected Hep2 cells, indicating that STAT3 siRNA inhibited the activity of STAT3. Transfection of Hep2 cells with STAT3 siRNA significantly inhibited STAT3 expression at both mRNA and protein level in Hep2 cells and the inhibition was characterized by time-dependent transfection. Treatment of Hep2 cells with STAT3 siRNA resulted in dose-dependent growth inhibition of Hep2, this significantly increased apoptotic cell rate, and decreased Bcl-2 expression level in Hep2 cells. STAT3 siRNA had an effect on induction of either early or late stage apoptosis. CONCLUSION: This study demonstrates that STAT3 siRNA effectively inhibits STAT3 gene expression in Hep2 cells leading to growth suppression and induction of apoptosis in Hep2 cells. The use of siRNA technique may provide a novel therapeutic approach to treat laryngeal cancer and other malignant tumors expressing constitutively activated STAT3.

[Relationship between expression of cyclin D1, Ki-67 and bcl-2 and biologic behavior in CD117-positive gastrointestinal stromal tumors].

OBJECTIVE: To investigate the clinicopathologic features of gastrointestinal stromal tumors (GISTs) and to identify reliable prognostic parameters. METHODS: Fifty-nine GISTs were studied by immunostaining of CD117, CD34, SMA, desmin, S-100, bcl-2, and Ki-67. Histopathologic evaluations included tumor size, necrosis, histological growth patterns, mitotic activities and tumor lymphocytic infiltrate. The patients were clinically followed for 2 to 9 years. Univariate, multivariate and correlative statistical evaluations were used to analyze the data. RESULTS: Among the 59 patients, 40 were alive and 15 died of their tumors at follow-up, the remaining 4 patients died of other causes. Pathological parameters that correlated with prognosis included tumor sizes of more than 5 cm, tumor tissue necrosis, mitotic cell count equal or higher than 5 per 50 high power field, Ki-67 labeling index (LI) equal or higher than 5% and intense bcl-2 immunostaining. Multivariate analysis showed that the mitotic count and Ki-67 LI were independent prognostic indicators. There was a correlation between mitotic count and Ki-67 LI. CONCLUSIONS: Mitotic count and Ki-67 LI are the best predictors for a poor outcome of GIST after surgical treatment. Ki-67 immunostaining may substitute mitotic count as a useful prognostic parameter.

[A prospective cohort study of risk factors for ventilator-associated pneumonia in intensive care unit].

OBJECTIVE: To study the risk factors of ventilator-associated pneumonia (VAP) in intensive care unit (ICU), in order to offer basic epidemiological data for the prevention of VAP in ICU. METHODS: A prospective cohort study on VAP was carried out in intubated or tracheotomied patients in ICU of Fudan University Zhongshan Hospital from Dec.1999 to Feb. 2001. Single factor analysis and muti-variable logistic regression analysis were adopted to identify the possible risk factors of VAP. RESULTS: (1) Ninety-eight patients were enrolled in this study, of which 52 were diagnosed as having VAP. The incidence of VAP was 53.1%. The incidence of VAP was 32.4 cases per 1000 intubation days. (2) Single factor analysis showed that history of chronic obstructive pulmonary emphysema, use of H2-receptor blocker, the days of antibiotic use, the types of antibiotics, enteral feeding, APACHEII scores, the duration of mechanic ventilation, pH of gastric juice, hypoalbuminemia, tracheotomy, reintubation, colonization of gram negative bacilli in oropharynx, and conscious disturbance were related to the occurrence of VAP. (3) Multi-variable logistic analysis showed statistical significance in combination of over two types of antibiotics (OR = 7.59, 95% CI 4.31 - 38.29), reintubation (OR = 4.73, 95% CI 2.33 - 11.67), APACHE II scores over 15 (OR = 2.02, 95% CI 1.59 - 26.74), pH of gastric juice over 4 (OR = 1.23, 95% CI 1.02 - 1.54) and prolongation of mechanic ventilation (OR = 1.15, 95% CI 1.01 - 3.75). CONCLUSIONS: Various factors contributed to VAP in ICU. Further clinical trials are needed for evidence of the above-mentioned possible risk factors.

[The impact of gastric colonization on the pathogenesis of ventilator-associated pneumonia].

OBJECTIVE: To investigate the risk factors for gastric bacterial colonization and its role in the endogenous pathogenesis of ventilator-associated pneumonia (VAP). METHODS: The type and concentration of gastric colonized bacteria and its relationship with the time when samples were collected, and with the type and occurrence order of the pathogens detected in samples from lower respiratory tract after the onset of VAP were analyzed dynamically in the patients with tracheal-intubation or tracheotomy in intensive care unit (ICU). RESULTS: (1) The isolation rate of colonized bacteria in gastric cavity was associated with the pH of gastric juice. When the pH of gastric juice was > 4, the isolation rate of Gram-negative bacilli (GNB) in gastric cavity markedly increased, achieving 52.5% in VAP group, and the incidence of VAP was higher (P = 0.017). The pH value of gastric juice was positively correlated with the logarithmic concentration of GNB in gastric cavity (P = 0.001). (2) As the duration of intubation prolonged, the isolation rate of enterobacteriaceae in VAP group increased, which was 45.2% on the fifth day of intubation. In contrast, the isolation rate in non-VAP group was 11.1% (P < 0.01). (3) The colonization of enterobacteriaceae in gastric cavity was 1 - 2 days earlier than that in oropharynx. The order was statistically significant (P = 0.015). (4) The reverse order of stomach-pharynx-lower respiratory tract colonization was found in 12 cases of the total 52 VAP patients and the order of stomach to lower respiratory tract colonization was found in 3 cases. CONCLUSIONS: (1) The pH value of gastric juice proved to be the major factor which influenced the colonization of bacteria especially GNB in gastric cavity. (2) The gastric cavity was probably a colonization place of GNB especially enterobacteriaceae. (3) The enterobateriaceae in gastric cavity tended to colonize reversely to oropharynx. (4) The phenotypic analysis of the pathogens showed that the reverse stomach-pharynx-lower respiratory tract infection route existed in VAP patients.

Biotransformation of triptolide and triptonide by cell suspension cultures of Catharanthus roseus.

Catharanthus roseus cell suspension cultures were used to bioconvert both triptolide (1) and triptonide (2). The same reaction path was followed in both biotransformations. Two biotransformed products were obtained and their structures identified as triptriolide (3) and 12beta,13alpha-dihydroxytriptonide (4), respectively, from 1 and 2. Product 4 is a new compound.