Comparison of different methods of nasogastric tube insertion in anesthetized and intubated patients: A meta-analysis.

BACKGROUND: Several techniques of nasogastric tube (NGT) insertion have been described in the literature with different success rates. AIM: To systematically search the literature and conduct a meta-analysis comparing the success rates, insertion time and complications associated with different techniques of NGT insertion in anesthetized and intubated patients. METHODS: An electronic search of the PubMed, Scopus, CENTRAL (Cochrane Central Register of Controlled Trials), and Google Scholar databases were performed up to October 31, 2019. We included 17 randomized controlled trials with 2500 participants in the meta-analysis. RESULTS: As compared to the conventional method, successful insertion of the NGT on first attempt was higher with modified techniques such as the reverse Sellick's maneuver [relative risk (RR) 1.94; 95% confidence interval (CI): 1.62-2.31], use of a frozen NGT (RR 1.55; 95%CI: 1.13-2.13), inserting the NGT with neck flexion and lateral neck pressure (RR 1.64; 95%CI: 1.10-2.45), endotracheal tube-assisted (RR 1.88; 95%CI: 1.52-2.32) and video-assisted placements (RR 1.60; 95%CI: 1.31-1.95). All the modified techniques also led to comparatively higher insertion success rates than the conventional technique. CONCLUSION: The use of modified techniques of NGT insertion such as the reverse Sellick's maneuver, neck flexion with lateral neck pressure, frozen NGT, endotracheal tube-guided or video-assisted methods result in a significantly better chance of successful tube insertion at first attempt as compared to the conventional technique. All modified techniques also significantly improve the overall chance of successful NGT placement as compared to the conventional method.

[Molecular epidemiological characteristics of HIV-1 strains isolated from newly diagnosed MSM subjects (2006-2010) in Beijing, China].

This study aims to analyze the molecular epidemiological characteristics of HIV-1 strains prevailing among men who have sex with men (MSM) in Beijing, China. The pol gene fragments from 250 newly diagnosed HIV-1-infected MSM individuals during 2006-2010 in Beijing were amplified by RT-nested PCR, sequenced, and phylogenetically analyzed. HIV-1 pol gene from 189 individuals were amplified and analyzed; 81 (42. 9%), 3 (1. 6%), 2 (1.0%), 88 (46. 6%), and 15 (7.9%) individuals were infected with HIV-1 subtypes B, B', C, CRF01_AE, and CRF07_BC, respectively. The subtypes B and CRF01_AE could both be grouped into two clusters, and CRFO7_BC strains shared high homology and were presumed to originate from a common ancestor. The HIV-1 circulating in MSM in Beijing had a lower genetic diversity than in heterosexuals. The HIV-1 epidemic (2006-2010) in MSM in Beijing was actually a rapid spread of HIV-1 CRF01 AE and B, or rather native strains of the two viruses.

[Analyses on antigen epitopes and drug resistance mutations of HIV-1 gag and pol genes].

To study the CTL antigen epitopes and drug resistance mutations of HIV-1 gag and pol genes through analyzing gag and pol gene sequences. The HIV-1 gag and pol gene fragments were amplified using nested polymerase chain reaction. A total of 23 PCR sequences, 449 cloned gag sequences and 402 cloned pol sequences were obtained. Sequence analyses showed the 23 samples were subtype B or B'. A total of 4 in 8 CTL antigen epitopes appeared 8 mutations in consensus sequence of subtype B and B'. There were no mutations found in the PCR sequences, whereas a few mutations were found in clone sequences (9.80%) in 5 antigen epitopes in p24 region. Eighteen PIs-related mutations and 24 RTIs-related mutations were found in PCR sequences and clone sequences in pol gene region, in which 17 (94.44%) PIs-related mutations and 15 (62.50%) RTIs-related mutations were found only in the clone sequences, respectively. The results showed that the prevalence of HIV-1 drug resistance strains in this study was at a higher level (17.39%), suggesting that some samples were resistant.to existing antiviral drugs.

[Genotyping and variability of HIV-1 in 26 cases of paid blood donors].

OBJECTIVE: To analyze the genome mutations of HIV-1 gag, pol and env genes from HIV-infected paid blood donors in rural central China. METHODS: DNA was extracted from peripheral blood mononuclear cells, gag (p17-p24), pol (PR-RT), env (C2-V5) genes were amplified by nested polymerase chain reaction (PCR), purified products were sequenced, and sequence data was analyzed by MEGA5.0 soft wares. RESULTS: Twenty-three samples were subtype B, two samples were recombinant of subtype B and subtype C, one sample was recombinant of subtype CRF01_AE and subtype B. PI major resistance mutations were not found in the PR region. M184V, K101E and G190A were detected in the RT region, respectively. CONCLUSION: Subtype B was the major HIV circulating genetic forms in this area. Most strains were sensitive to high active anti-retroviral therapy (HARRT). 91.7% V3 loop tip motifs of X4-tropic strains was GPGR. It showed that GPGR might be associated with accelerate disease progression to AIDS.

[Variation of the V3 loop tip motifs and primary drug resistance of HIV-1 strains].

OBJECTIVE: To study the characteristics of the variation of the V3 loop tip motifs and the drug resistance in the primary treatment patients. METHODS: The partial region of the HIV-1 env and pol gene in 51 samples was amplified by nested polymerase chain reaction (PCR) ,purified products were cloned into the vectors, the obtained were analyzed by MEGA soft wares. RESULTS: The V3 loop tip motifs had four types in our study (GPGR, GPGQ, GPGK, GQGR); the study on the drug resistance in primary treatment patients, showed that there were not major resistance associated with PI, and the resistance were minor mutations in protease gene. In the RT region, there were nine resistance mutants were single NRTIs or NNRTIs. CONCLUSION: The GPGR which was the typical western V3 loop tip motifs attained to 44.44%. This results showed that the percentage of primary drug resistance was still low in our study region, suggesting no need for genotyping detection in blood donor patients before primary therapy.

[Study of Gag gene antigen epitypes variation and the quasispecies group characteristics in Henan area HIV-1 strains].

OBJECTIVE: To study the characteristics of the variation of antigen epitopes and quasispecies group in the HIV-1 viruses in Henan province in China. METHODS: The region of the p17-p24 of the HIV-1 gag gene was amplified by nested polymerse chain reaction (PCR), purified products were cloned into the vector, the obtained were analyzed by MEGA soft wares. RESULTS: B' subtype strains were predominant in Henan province, the mutations in antigen epitypes of the p17 region of the gag gene focus on E62g (55.8%), Y79f (48.9%), T84V (48.9), I44V (44.2%), the p24 region had not found the distinct mutation. CONCLUSION: Both the PCR sequences and clone strains sequences demonstrated that four antigen epitopes mutations in p17 region of the HIV B' subtype gag gene, and the region of p24 was more conservative, which was suitable for development of the epitope vaccien.

[Expression and purification of HIV-1 subtype C Gp120, and its antibodies preparation].

OBJECTIVE: To prepare HIV-1 subtype C Gp120 protein and to produce its polyclonal antibodies. METHODS: A C-terminal fragment of gp120 gene was amplified by PCR from a plasmid expressing full-length HIV-1 subtype C gp160 gene. The length of the subtype C gp120 fragment was 612 nt and it encodes 204 amino acid residues. The resulting DNA construct was cloned into a prokaryotic expression vector (pET-30a) and recombinant pET-30a-gp120 was expressed in Escherichia coli BL21 (DE3) as an insoluble protein. The vector also contained a six-histidine (His6) tag at the C-terminus for convenient purification. To produce subtype C Gp120-specific polyclonal antibodies, New-Zealand rabbit was immunized with the purified Gp120 protein. Serum samples were tested by enzyme-linked immunosorbent assays (ELISA) to determine the level of antibodies. And Western blotting was used to further verify whether the polyclonal antibodies could specifically recognize subtype C Gp160 protein expressed in mammalian cells. RESULTS: HIV-1 subtype C Gp120 protein was successfully acquired and the titer of its polyclonal antibodies was 1:204 800. The polyclonal antibodies efficiently recognized Subtype C Gp160 protein expressed in COS-1 cells. CONCLUSION: HIV-1 subtype C Gp120 fusion protein with high purity was obtained and its corresponding polyclonal antibodies with high titer were produced.

Biological impact of hepatitis B virus X-hepatitis C virus core fusion gene on human hepatocytes.

AIM: To investigate the biological impact of hepatitis B virus X- hepatitis C virus core (HBV X-HCV C) fusion gene on hepatoma cells. METHODS: The recombinant adenoviruses Ad-XC, Ad-X and Ad-C expressing HBV X-HCV C fusion gene, HBV X gene and HCV C gene were constructed, respectively. Hepatoma cells were infected with different recombinant adenoviruses. MTT, colony-forming experiment, FCM, TUNEL assay were performed to observe the biological impact of the HBV X-HCV C fusion gene on liver cells. RESULTS: MTT showed that the Ad-XC group cells grew faster than the other group cells. Colony-forming experiment showed that the colony-forming rate for the Ad-XC group cells was significantly higher than that for the other group cells. FCM analysis showed that Ad-XC/Ad-X/Ad-C infection enhanced the progression of G1-->S phase in the HepG2 cell cycle. The apoptosis index of the Ad-XC, Ad-X, Ad-C group cells was significantly lower than that of the Ad0 and control group cells. Semi-quantitative RT-PCR showed that the expression level of c-myc was the highest in Ad-XC infected cells. Tumor formation was found at the injected site of mice inoculated with Ad-XC-infected LO2 cells, but not in control mice. CONCLUSION: Ad-XC, Ad-X and Ad-C facilitate the proliferation activity of HepG2 cells and inhibit their apoptosis in vitro. The effect of Ad-XC is significantly stronger than that of Ad-X and Ad-C. Up-regulation of c-myc may be one of the mechanisms underlying the synergism of HBV X and HCV C genes on hepatocarcinogenesis in athymic nude mice.

[Vasoactive intestinal peptide attenuates apoptosis and iNOS protein expression induced by cerebral ischemia in the rat].

OBJECTIVE: To explore the neuroprotective action of vasoactive intestinal peptide (VIP) on ischemia and reperfusion in the rat. METHODS: VIP was given via intracerebroventriclar injection after a 2 hour transient middle cerebral artery occlusion using filament model. The infarct volume was investigated with TTC stain. Apoptosis in the ischemic boundary zone were evaluated with TUNEL stain. Western blotting were used to analyze the iNOS protein expression as well. RESULTS: After VIP injection, the relative infarct volume of rats was significantly reduced by approximately 28% campared to that of the control groups at 1 day (P < 0.05). The number of TUNEL positive cells was significantly decreased in the ischemic boundary zone, and then the expression of iNOS was remarkablely decreased as well (P < 0.05). CONCLUSION: VIP has a neuroprotective effect on cerebral ischemia and reperfusion. The mechanism seems to involve decreasing the apoptosis and down-regulating the iNOS expression.

[Effect of puerarin on PC12 cells apoptosis induced by Abeta25-35 in vitro].

OBJECTIVE: To establish a nerve cell injury model by incubating PC12 cell line in the presence of Abeta25-35 to study the effect of puerarin on apoptosis of nerve cells. METHODS: PC12 cells were incubated with Abeta25-35 and puerarin. Cell viability was detected by MTT. The cellular morphology was observed with electron microscopy. FITC-labeled Annexin V and propidium iodide were adopted to evaluate the rate of cell apoptosis in different groups by means of flow cytometry. RESULTS: Following incubation Abeta25-35, the cells were induced to undergo apoptosis. The viability of PC12 cells decreased in a time-dependent manner. Morphological evidences for apoptosis nuclear condensation were observed in PC12 cells. Cells incubated in the presence of Abeta25-35 showed increasing apoptotic rates, but cells treated with puerarin and Abeta25-35 revealed decreasing apoptotic rates, it demonstrated that puerarin had a significant protective action against Abeta25-35 evoked apoptosis. CONCLUSION: Puerarin can resist the adverse effects of Abeta25-35 on increasing apoptotic rates, and it has the protective function towards nerve cells.

[Construction and expression of fusion gene encoding Hyper-IL-6 in mammalian cells].

AIM: To construct and express fusion gene encoding Hyper-IL-6 in mammalian cells. METHODS: Using geneSOEing method, human sIL-6R cDNA was fused with IL-6 cDNA by a linker rich in glycine through PCR technique and cloned into pIRES(2)-EGFP. The constructed plasmid was transfected into mammalian cells. The expression of fusion gene encoding Hyper-IL-6 was detected by GFP and RT-PCR and immunocytochemistry. RESULTS: The recombinant plasmid pIRES-HIL-6 was successfully constructed and expressed in mammalian cells. CONCLUSION: The success in construction and expression of human Hyper-IL-6 makes it possible to further study its biological functions.

[Construction and immune potency of recombinant adenovirus containing codon-modified HIV-1 gp120].

BACKGROUND: To construct replication-deficient recombinant adenovirus expressing wild and codon-modified HIV-1 gp120. METHODS: The viral codons were changed to the codon usage of highly expressed mammal gene, the resulting modified gp120 gene was synthesized. The wild and modified gp120 genes were cloned into shuttle vector pShuttle-CMV respectively, and then the constructed plasmids containing gp120 gene was cotransformed with the backbone vector pADeasy-1 into E.coli BJ5183. Transfection of the recombinant AdEasy plasmid into 293 cells was performed to obtain recombinant adenoviruses. The mice were immunized with the recombinant adenoviruses. Their immunogenicity was evaluated by testing antibody and CTL levels of immunized mice. RESULTS: Two strains of recombinant adenovirus expressing wild and codon-modified HIV-1 gp120 were obtained. The protein expressing level of the recombinant adenoviruses containing modified genes was much higher than that containing wild genes. The mice immunized with recombinant adenoviruses elicited HIV-1 specific antibody and CTL response. The rAd-mod gp120 group was better than the rAd-wt gp120 group. CONCLUSION: Replication-deficient recombinant adenovirus expressing HIV-1 gp120 can elicit HIV-1 specific humoral and cellular response, the codon-modified recombinant virus was more efficient than the native.

[Immune potency of recombinant adeno-associated virus combined with recombinant adenovirus vaccine containing HIV-1 gp120].

OBJECTIVE: To study the immune effect of recombinant adeno-associated virus (rAAV) combined with recombinant adenovirus (rAdV) vaccine in BALB/c mice. METHODS: The codon-modified HIV-1 gp120 gene was inserted into plasmid of adeno-associated virus and adenovirus vector separately. Then the rAAV and rAdV vaccines were constructed. BALB/c mice were immunized with rAAV and rAdV vaccines in different administration scheme. The IgG antibody was detected by ELISA and CTL response was detected by intracellular cytokine stain assay. RESULTS: Both rAAV and rAdV vaccine could express gp120 gene; the mice primed with rAAV at week 0, 2 and boosted with rAdV at week 5, 14 and 20 elicited the strongest gp120 specific CTL and IgG antibody response. CONCLUSION: The mice primed with rAAV and boosted with rAdV could elicit specific CTL response and IgG antibody.

[Construction and analysis of activity of an HIV-1/bovine immunodeficiency virus chimeric clone cDNA].

OBJECTIVE: Chimeric human/bovine immunodeficiency virus (HBIV) cDNA was constructed by replacing HIV tat and LTR with bovine immunodeficiency virus (BIV) tat and LTR to study the activity of BIV tat and LTR in the chimerae. METHODS: The target fragments of BIV tat, LTR and HIV gag, pol, env were respectively amplified by using PCR and sequentially inserted into pBluescript SK(+) vector. The chimeric clone was transfected into human MT4 cells. The transcript and gene expression of the HBIV chimeric virus were detected by using RT-PCR and a reverse transcriptase assay, respectively. RESULTS: BIV tat mRNA and HIV gag mRNA were detected. The reverse transcriptase activity of the chimeric virus was analyzed in the fluctuation curve. CONCLUSIONS: In chimeric HBIV cDNA transfected MT?4 cells, BIV tat and HIV gag were transcripted. The reverse transcriptase of the chimeric virus had biological activity. These data suggest that in MT4 cells, BIV LTR had promoter activity and BIV tat had the function of transactivation in the chimeric virus. The study of the chimeric virus with infectivity is in progress.