[Occurrence Characteristics of Microplastics and Metal Elements in the Surface Water of Huangpu River and Their Associations with Metal Resistance Genes].

Urban rivers have been regarded as the "hotspots" for microplastic (MPs) and metal contamination as they play important roles in pollution migration. However, as important sinks and sources of resistance genes, there has been little to no research investigating the associations between MPs, metal contaminations, and metal resistance genes (MRGs). Ten water samples were collected from the Huangpu River in situ; along with metal elements, MPs characteristics analyzed. Metal resistance genes and mobile genetic elements (MGEs) in waters and MPs were detected using metagenomic technology. As a result, the highest metal concentration was that of Sb in surface water (3.16±0.419) µg·L-1. The average abundance of MPs was (1.78±0.84) n·L-1, and the peak levels located in industrial and densely populated areas, which was significantly higher than those in agricultural and low population density areas. Fibrous, small-size (<0.5 mm), and transparent polyethylene terephthalate (PET) were the largest contributors of MPs. Eighteen MRGs were detected in all the samples. The relative abundance of MRGs in water was 1.68±0.21. The most dominant MRGs subtypes were merR and ruvB, which are subtypes resistant to mercury and Multi_metals. Correlation analysis showed that chromium and nickel in waters were significantly positively associated with MRG-Cr, MRG-Ni, and Multi_metals resistance genes. For MPs particles, the relative abundance of MRGs was 1.63±0.53. The most dominant MRGs subtypes were merT-P and copB, which also belong to mercury-resistant and Multi_metals. The Multi_metals resistance gene, ctpC, cueA, czrA, kmtR, etc., had significant positive associations with Ni, Cr, and Sb in waters. Compared with water samples, MPs selectively enriched merT-P, copB, ziaA, sodA, and dmeF. Additionally, the co-occurrence patterns of MRGs and MGEs were explored based on network analysis. In water samples, the transposases (tnpA_1 and tnpA_2), integrase (qacEdelta), and insertion sequence (IS91) were the major contributors of the horizontal gene transfer (HGT) of specific MRGs. Multiple subtypes resistant to copper and Multi_metals resistance genes on MPs were positively associated with IncFIC(FII), Rep7, rep7, and rep13, which were subtypes of plasmids. The presence of MPs exerted a significant impact on HGT of specific MRGs mediated by plasmids.

Reparative effects of chronic intermittent hypobaric hypoxia pre­treatment on intervertebral disc degeneration in rats.

Previous studies have indicated that chronic intermittent hypobaric hypoxia (CIHH) preconditioning can inhibit TNF­α and other related inflammatory cytokines and exerts protective effect on intervertebral disc degeneration disease (IDD) in rats; however, the mechanism is still unclear. The present study aimed to explore the repair mechanisms of CIHH on IDD in rats. In the experiment, 48 adult Sprague­Dawley rats were selected and randomly divided into an experimental group (CIHH­IDD), a degenerative group (IDD) and a control group (CON). The CIHH­IDD group of rats (n=16) were treated with CIHH (simulated 3000 m altitude, 5 h per day, 28 days; PO2=108.8 mmHg) before disc degeneration surgery. The IDD group of rats (n=16) underwent tail­vertebral intervertebral disc surgery to establish a model of intervertebral disc degeneration. The CON group of rats (n=16) did not receive any treatments. After surgery, the disc height index was calculated using X­ray analysis of rat tail vertebrae, the degeneration process was observed and repair was evaluated by chemically staining degenerative intervertebral disc tissue slices. The expression levels of basic fibroblast growth factor (bFGF), TGFß1, Collagen I and Collagen II were measured in the intervertebral disc tissue using western blotting; while the expression levels of bFGF, TGFß1 and hypoxia­inducible factor 1­α (HIF­1α) were measured in rat serum using ELISA. The results demonstrated that: i) The degree of intervertebral disc height degeneration in CIHH­IDD rats was significantly lower compared with that in IDD rats (P<0.05); ii) the expression levels of bFGF, TGFß1 and HIF­1α were higher in CIHH­IDD rat serum compared with those in IDD rat serum (P<0.05); iii) optical microscopy revealed that the degree of disc degeneration was relatively mild in CIHH­IDD rats; and iv) the protein expression levels of bFGF, TGFß1 and collagen II were increased in CIHH­IDD rat intervertebral disc tissues compared with those of IDD rats, while the overexpression of collagen I protein was inhibited. Overall, after CIHH pre­treatment, the expression levels of bFGF and TGFß1 were up­regulated, which play notable roles in repairing degenerative intervertebral discs in rats.

[Salt stress tolerance of cucumber-grafted rootstocks].

Taking 4 different Cucurbita maxima x C. moschata rootstocks for cucumber (Cucumis sativus) as test materials, a solution culture experiment was conducted to study their growth and antioxidative enzyme activities under the stresses of Ca(NO3)2 and NaCl, with the salt stress tolerance of the rootstocks evaluated by subordinate function. At 30 mmol x L(-1) of Ca (NO3)2 or 45 mmol x L(-1) of NaCl, the growth of the rootstock seedlings was improved; but at 60 and 120 mmol x L(-1) of Ca(NO3)2 or 90 and 180 mmol x L(-1) of NaCl, the growth and the antioxidative systems of the seedlings were inhibited, and the salt injury index of 'Qingzhen No. 1' was the smallest, with the decrement of biomass and SOD, POD and CAT activities and the increment of relative conductance being significantly lower than those of the others. Under the stress of high concentration Ca(NO3)2, the SOD, POD and CAT activities of test rootstocks were higher, and the salt injury index and relative conductance were lower, as compared with those under high concentration NaCl, suggesting that the damage of Ca(NO3)2 stress to cucumber-grafted rootstock were smaller than that of NaCl stress. Among the 4 rootstocks, 'Qingzhen No. 1' had the strongest salt stress tolerance, followed by 'Zuomu Nangua', 'Fengyuan Tiejia', and 'Chaoba Nangua'.

[Study on the immune response of the therapeutic multi-epitope gene vaccine of hepatitis B virus in mice].

AIM: To study the immunogenicity of the therapeutic multi-epitope gene vaccine of Hepatitis B virus. METHODS: Multi-epitope gene of Hepatitis B virus was cloned into prokaryon expression vector pBAD/gIIIA to express a non-fusional antigen B-BPT and BALB/c mice were immunized with the antigen. Cytotoxic T-lymphocyte(CTL) was determined with CytoTox96 kit which quantitatively measures the lactate dehydrogenase(LDH) that is released on cell lysis. CD4(+);, CD8(+); T lymphocytes subsets in immunized mice was detected by using flow cytometry (FCM). Lymphocyte proliferation response was completed by MTT colorimetry. RESULTS: Injection of B-BPT elicited high-level of CTL response and also stimulus spleen lymphocytes to proliferate effectively. CONCLUSION: B-BPT can induce specific cellular immune responses and may be a good candidate for therapeutic vaccine.

[Effect of adjusting the immunosuppressants on the prognosis of the infection in the patients with liver transplantation].

OBJECTIVE: To explore the method of adjusting the immunosuppressants in serious infection after liver transplantation. METHODS: With reference to sepsis-related organ failure assessment (SOFA), 2005.1-2007.12, when the patient's score > or =15, the immunosuppressants were withdrawn, and the patients were given powerful antibiotics and the other treatments in combination. They were further divided into two groups, SOFA 15-17 (group A, 10 cases) and > or =18 (group B, 16 cases). They were compared, and also with the patients without stoppage of immunosuppressants (group C, 13 cases, 2003.3-2004.12). After withdrawing the immunosuppressant, the rejection incidence and times, the changes in SOFA score and mortality and their relationships were analyzed. RESULTS: After adjusting the immunosuppressant and with control of serious infections, rejection occurred in 9 patients, with 5 cases in group A (50.0%), 4 in B (25.0%), none in C. The differences among groups showed statistically significant difference (chi(2)=8.0, P=0.02), but no difference was seen between group A and B (chi(2)=1.70, P=0.19). When the rejection developed, the SOFA score decreased obviously (9.78+/-3.14 vs. 17.22+/-1.86, t=6.10, P=0.00). The time of rejection was (17.56+/-2.60) days after stopping the immunosuppressant. All 25 deaths were due to serious infection with multiple organ dysfunction syndrome, but not rejection. Five deaths occurred in group A (50.0%), 7 in B (43.8%), 13 in C (100.0%). Not a single patient with rejection died from infection. Proper adjustment of the immunosuppressants could decrease the mortality (chi(2)=7.60, P=0.02). CONCLUSION: SOFA score could be used to guide the adjustment of the immunosuppressants, when SOFA> or =15, the immunosuppressants could be stopped, which would not increase the rejection incidence and decrease mortality. The lower the SOFA score is, the faster the patients recuperate better, but more rejection develops. In order to adjust the immunosuppressant in time, the period with high SOFA score should be shortened.

[Construction and expression of non-fusional expression vector of the multi-epitope gene of hepatitis B virus].

AIM: To study the cloning, expression and antigen of therapeutic multi-epitope gene of hepatitis B virus. METHODS: The multi-epitope gene of hepatitis B virus(BPT) was designed, synthesized and cloned into the prokaryotic expression vector pBAD/gIIIA. Then it was transformed into E.coli Top10 and multi-epitope protein of hepatitis B virus(B-BPT) was expressed under the induction of Arabinose. The immunogenicity of the protein was analyzed by Western blot detection. RESULTS: The recombinant plasmid pBAD/BPT was constructed successfully and the protein of multi-epitope gene of hepatitis B virus was expressed in E.coli. Western blot detection showed the protein had ideal antigenicity. CONCLUSION: The design of therapeutic multi-epitope gene of hepatitis B virus is proved to be correct. The expressed protein may be a good therapeutic vaccine.

[Impact of adaptive positive end expiratory pressure and mechanical ventilation on hemodynamics and oxygen kinetics in post-liver transplantation patients].

OBJECTIVE: To determine the impact of adaptive positive end expiratory pressure (PEEP) and mechanical ventilation on hemodynamics and oxygen kinetics in post-liver transplantation patients. METHODS: The study included 11 patients who accepted mechanical ventilation after piggyback liver transplantation. Swan-Ganz catheter and radial artery catheter were used to monitor the cardiac output (CO), mean pulmonary arterial pressure (MPAP), mean arterial blood pressure (MABP) and central venous pressure (CVP) and airway pressure. After transplantation, PEEP of 0, 5, 10 and 15 cm H(2)O (1 cm H(2)O=0.098 kPa) was instituted to support the ventilation alternately. After 30 minutes, pressure regulated volume controlled ventilation (PRVCV) and pressure controlled synchronized intermittent mandatory ventilation+pressure support ventilation (PC-SIMV+PSV) were used to support the ventilation alternately and the indexes of hemodynamics and oxygen kinetics were analyzed. RESULTS: The data showed that differences existed in peak airway pressure, mean airway pressure, CVP and MPAP when different levels of PEEP were used. These indexes were significantly higher in PEEP of 15 and 10 cm H(2)O than those in PEEP of 0 and 5 cm H(2)O.There were no differences in pH, partial pressure of carbon dioxide in arterial blood (PaCO(2)), pressure of oxygen in arterial blood (PaO(2)), arterial oxygen saturation (SaO(2)), oxygen delivery (DO(2)), oxygen consumption (VO(2)) and oxygen extraction rate (O(2)ER) at different levels of PEEP. The airway pressure was significantly lower under PRVCV pattern than those under PC-SIMV+PSV pattern [(8.78+/-1.53) cm H(2)O vs. (11.64+/-3.30) cm H(2)O, P<0.05]. There were no differences in other indexes between these two mechanical ventilation patterns. CONCLUSION: These date suggested that a low level of PEEP (5 cm H(2)O) during mechanical ventilation should be used in post-liver transplantation patients in order to decrease the influence of PEEP on systemic circulation and hepatic regurgitation. PRVCV could be a more suitable mechanical ventilation pattern for patient after liver transplantation.

[Effect of HBsAg pulsed dendritic cells on the functions of cytokine-induced killer cells].

AIM: To explore the effects of HBsAg-pulsed dendritic cells (DCs) on the proliferation and killing functions of cytokine-induced killer (CIK) cells. METHODS: The peripheral blood mononuclear cells (PBMCs) were isolated from the patients with chronic hepatitis B by the routine method, and induced into specific DCs with HBsAg pulsed. The (3)H-TdR incorporation method was used to determine the stimulation effect of HBsAg-pulsed DCs on the proliferation of CIK cells. LDH release assay was used to measure the specific killing activity of CIK cells on HepG2215 cells. RESULTS: The HBsAg-pulsed DCs could induce the memory proliferation of CIK cells and strengthen the killing activity of CIK cells (P<0.05). CONCLUSION: HBsAg-pulsed DCs can enhance the proliferation and killing functions of CIK cells.

[Cytoxic T lymphocyte responses to hepatitis B virus small surface antigen in BALB/c mice].

OBJECTIVE: To observe cytotoxic T lymphocytes (CTL) responses induced by immunization of mice with hepatis B small surface antigen (S-HBsAg). METHODS: BALB/c(H-2d) mice were injected intraperitoneally with S-HBsAg at the doses ranging from 0-5 microg with a booster injection 2 weeks later. Four weeks after the booster immunization, the specific cytotoxic reactivity of the spleen lymphocytes isolated from the immunized mice, following stimulation by S-HBsAg specific CTL epitope peptide in vitro, with 51Cr-labeled P815 cells treated with the peptide was observed. RESULTS: The percentage of specific release of 51Cr in mice immunized with S-HBsAg at the doses of 0, 0.65, 1.25, 2.5, and 5 microg was 31.21%+/-9.23%, 42.36%+/-19.32%, 91.21%+/-22.97%, 69.25%+/-24.13% and 51.49%+/-21.661% respectively. In mice receiving the only primary vaccination, the corresponding percentage was 27.34%+/-14.25%, 32.27%+/-15.35%, 56.28%+/-24.35%, 44.34%+/-18.65% and 40.76+/-56% respectively. CONCLUSION: Immunization with S-HBsAg efficiently elicits CTL response in BALB/c mice in a dose-dependent manner and enhanced by booster immunization.

[Retrospective analysis on clinical features of 35 patients with severe acute respiratory syndrome].

OBJECTIVE: To analyze the clinical features of severe acute respiratory syndrome (SARS). METHODS: The clinical features of 35 patients with SARS in the past five months were retrospectively studied, and compared with 35 patients with community-acquired pneumonia. Consecutive blood samples from 13 patients with SARS and 10 healthy volunteers were collected. The CD+4 and CD+8 in T cell in peripheral blood were detected by flow cytometry. RESULTS: The most common symptoms included fever (in 100.0 percent of the patients), cough (74.3 percent), headache (45.7 percent), myalgia (45.7 percent) and lymphopenia (20/33). Serial chest radiographs showed progressive multi-infiltration in the lung fields. The CD+4 and CD+8 in T cell in 13 patients with SARS significantly decreased [CD+4: (16.10+/-4.31) percent vs. (38.30+/-8.52) percent, t=8.174,P<0.01; CD+8: (19.90+/-5.40) percent vs. (28.38+/-4.33) percent, t=4.055, P<0.01]. The time of bringing down the fever and the time of absorption of pathological changes in SARS patients were prolonged than those of the pneumonia patients [the time of bringing down the fever (13.92+/-8.35) days vs. (3.86+/-1.42)days, t=16.490,P=0.000;the time of absorption of pathological changes: (11.97+/-4.41) days vs. (9.21+/-4.42) days, t=3.082,P=0.003]. CONCLUSION: SARS is a serious respiratory illness, the most common symptoms are fever, cough, headache and myalgia, other common findings are lymphopenia, the CD+4 and CD+8 in T cell in peripheral blood decrease and multi-infiltrate through out the lung fields.