Correlation between analgesia in the postanesthesia care unit and intraoperative remifentanil / 中国医学科学院学报

<p><b>OBJECTIVE</b>To analyze the correlation between analgesia in the postanesthesia care unit and intraoperative remifentanil.</p><p><b>METHODS</b>The data of 5 594 patients in the postanesthesia care unit were retrospectively retrieved from the database of electronic medical record. The use of analgesic drugs in the postanesthesia care unit and intraoperative remifentanil was recorded, and case-control study was performed based on these enumeration data.</p><p><b>RESULTS</b>A total of 205 (3.66%) patients out of 5 594 in the postanesthesia care unit were administered with analgesic drugs. In the grouped case-control study, remifentanil was intraoperatively used in 87 patients in the case group (n=205) and in 1 224 patients in the control group (n=5 389) (OR = 2.51, 95% CI=1.87-3.36, P=0.000). There were 205 "paired numbers" in the matched case-control study (OR=1.67, 95% CI=1.12-2.80, P=0.011).</p><p><b>CONCLUSION</b>The analgesia in the postanesthesia care unit may be correlated with intraoperative remifentanil to a certain extent.</p>

HIV-1 infection changes miRNA expression profile in the whole blood / 病毒学报

To describe the unique miRNA profiles for HIV seropositive individuals and identify significantly differently expressed miRNAs, we determined the expression level of 754 miRNAs of 10 HIV seropositive individuals and 10 HIV seronegative individuals by using the Taqman low density microRNA array. BRB-Array Tool was used to conduct the significance analysis, and the DIANA online tool was used to perform the miRNA target prediction and pathway analysis. A total of 56 significantly differentially expressed miRNAs were identified by microarray between HIV seropositive and seronegative individuals. Among them, 49 miRNAs were down-regulated and 7 were up-regulated, partially overlapped with reported data. Predicted target genes were mainly involved in MAPK, TGF-beta and Wnt pathways. The results shows that miRNA profile changes in HIV-1 seropositive individuals, and the 56 differentially expressed miRNAs may play important role during HIV infection. Further studies on these miRNAs may be helpful for identify key molecules involved in HIV infection and potential diagnostic markers.

HIV-1 infection up-regulating expression of interferon-stimulated gene 15 in cell lines / 病毒学报

To investigate whether HIV-1 infection affects expression of interferon-stimulated gene 15 (ISG15) and determine the antiviral effect of ISG15 in vitro, ISG15 expression at transcription and protein level and supernatant p24 of HIV-1 was detected in various HIV-1 infected or transfected cell lines, respec tively. HIV-1 molecular clone pNL4-3 was used to transfect 293T, TZM-bl and HeLa cells while HIV-1 pseudo-typed virus was used to infect Jurkat, MT-1 and THP-1 cells. After twenty-four hours post infection or transfection, cells were harvested for extraction of total RNAs and subsequently used in real time PCR for quantification of ISG15 transcriptional expression. After forty-eight hours post infection or transfection, cells were harvested for extraction of total proteins to detect ISG15 protein expression. A significant up-regulation of ISG15 at transcription level was observed in HIV-1 infected or transfected cell lines, particulaly in THP-1 and TZM-bl cells. Up-regulation of ISG15 protein was observed only in TZM-bl cell. Cotransfection of ISG15 and HIV-1 indicated that ISG15 inhibited production of HIV-1 progeny virus in a dose and time depend manner in 293T cell but not TZM-bl cell. These results revealed upregulating ISG15 expression in transcriptional level and potential antagonistic mechanism against ISG15 by HIV-1 infection, simultanelusly.

Immunogenicities and comparison of DNA vaccines encoding pol genes derived from B`/C and A/E recombinant HIV-1 strains / 中华预防医学杂志

<p><b>OBJECTIVE</b>To construct and compare the immunogenicities of DNA vaccines expressing pol genes derived from B`/C and A/E recombinant subtypes of HIV-1 in China.</p><p><b>METHODS</b>Two DNA vaccines were constructed by inserting the codon optimized pol genes derived from B'/C and A/E subtypes of HIV-1 into mammalian expression vector pSV1.0. In vitro expression efficiencies of the two DNA vaccines were determined by Western blotting and their immunogenicities were compared by i.m. immunizing female BALB/c mice. After immunization, mice splenocytes were isolated sterilely and IFN-γ based enzyme linked immunospot assay (ELISPOT) was employed to read out the specific T cell immunity.</p><p><b>RESULTS</b>The constructed DNA vaccines were validated by restriction enzyme digestion and DNA sequencing. Western blotting result showed both of the two DNA vaccines could be expressed at appreciable levels in vitro. Under the stimulation of Consensus B Pol peptide pools, specific T cell frequency elicited by pSVAE-Pol was (636±178) SFCs/10(6) splenocytes; specific T cell frequency elicited by pSVCN-Pol was (468±265)SFCs/10(6) splenocytes (P=0.412). Under the stimulation of HIV-1 AE2f Pol peptide pools, specific T cell frequency elicited by pSVAE-Pol was (1378±611) SFCs/10(6) splenocytes; specific T cell frequency elicited by pSVCN-Pol was (713±61) SFCs/10(6) splenocytes (P=0.134). Further analysis suggested pSVAE-Pol induced specific T cell responses mainly focused on Pol 1 peptide pool, while, in addition to induce Pol 1 specific T cell responses, pSVCN-Pol could also elicit T cell responses against consensus B Pol 2 peptide pool.</p><p><b>CONCLUSION</b>Although pSVAE-Pol was more immunogenic, pSVCN-Pol could induce T cell responses against broader epitope spectrum. Rational vaccine design may need combine them together.</p>

Immunization with HBsAg-Fc fusion protein induces a predominant production of Th1 cytokines and reduces HBsAg level in transgenic mice / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The Fc receptor associated pathway might improve the immune responses against hepatitis B virus (HBV) as previously described by us. In addition, the Flt3 ligand (FL) has been reported to potentiate antigen presenting cells in vivo and may act as a potential adjuvant to boost antigen-specific immune responses. In this study, the immune efficacies of a set of fusion proteins of HBsAg and Fc and/or FL were evaluated in HBsAg transgenic mice.</p><p><b>METHODS</b>The fusion proteins composed of HBsAg and the Fc domain of murine IgG1 (HBsAg-Fc) and/or the Flt3 ligand, and yeast-derived recombinant HBsAg were used as immunogen to immunize HBsAg transgenic mice, respectively. Serum and liver HBsAg levels, serum anti-HBsAg and cytokine profile, and the activities of alanine aminotransferase (ALT)/AST were investigated after immunization.</p><p><b>RESULTS</b>After six injections, the most pronounced decrease in serum and liver HBsAg levels was observed in the HBsAg-Fc immunized group. In addition, serum Th1 cytokines and ALT/AST activities were highest in this group, indicating an effective induction of a favorable cellular immune response. Interestingly, the fusion protein containing HBsAg-Fc and the Flt3 ligand stimulated an alternative Th1-type immune response featured with high level productions of tumor necrosis factor α (TNF-α) and monocyte chemoabstractant protein 1 (MCP-1), causing a more severe cytotoxicity in hepatocytes while showed less effective in reducing serum HBsAg level.</p><p><b>CONCLUSION</b>HBsAg-Fc is effective in eliciting both the humoral and cellular immune responses against HBsAg in HBsAg transgenic mice, which makes it a potential immunogen for the immunotherapy of chronic hepatitis B.</p>

Development and identification of polyclonal antibodies against HIV-1 Vpr-derived polypeptides / 病毒学报

To develop polyclonal antibodies against predicted B cell epitopes in HIV-1 accessory protein Vpr, the prepared consensus Vpr amino acid sequence was used to predict potential B cell epitopes by online softwares (ABCpred and Bcepred), the synthesized polypeptides of B-cell epitopes were subsequently conjugated with keyhole limpet hemocyanin (KLH) and then used to immunize rabbits. The antibody titers were determined by ELISA, and antibody specifity was analyzed by Western-Blotting and immunoprecipitation, respectively. Amino acid residues 3-19 (N) and 82-95 (C) of Vpr were predicted as the potential B cell epitopes. After inoculation of the conjugation of synthesized peptide to KLH, the antibody titers in rabbit sera against N and C peptides reached more than 1:100000 by ELISA. Western-Blotting analysis showed that the polyclonal antibodies reacted with both wild Vpr and fusion protein of GFP with Vpr, no matter Vpr was derived from HIV-1 B subtype or CRF07_BC recombinant form; Immunoprecipitation analysis showed similar reactions to Western-Blotting results. Two B cell epitopes of Vpr were successfully predicted by Bio-informatics methods and polyclonal antibodies against those peptides could be successfully prepared.

HLA-DR expression on regulatory T cells is closely associated with the global immune activation in HIV-1 infected subjects naïve to antiretroviral therapy / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The frequencies of regulatory T cells (Tregs) increased over the HIV infection but its counts actually decreased. We proposed that the decrease of Treg counts may cause the reduction of inhibitory effect and thereby account for the over-activation of Tregs during HIV infection. However, it remains unknown whether Tregs are also over-activated and thereafter the activation induced death may lead to the decrease of Tregs.</p><p><b>METHODS</b>Tregs were defined as CD4(+)CD25(+)CD127(lo/-) T cells. Eighty-one HIV-1 infected patients were enrolled in our study, and twenty-two HIV-1 seronegative donors were recruited as the control. The levels of HLA-DR on Tregs were determined by FACSAria flow cytometer.</p><p><b>RESULTS</b>Compared to HIV-1 seronegative donors, the levels of HLA-DR on CD4(+)CD25(+)CD127(lo/-) Tregs were significantly increased in HIV-1 infected patients, and its increase was positively associated with viral loads (r = 0.3163, P = 0.004) and negatively with CD4 T-cell counts (r = -0.4153, P < 0.0001). In addition, significant associations between HLA-DR expression on CD4(+)CD25(+)CD127(lo/-) Tregs and the percentages of HLA-DR, CD38, Ki67 expressing CD4(+) and CD8(+) T cells were also identified.</p><p><b>CONCLUSION</b>HLA-DR on Tregs is a good marker for viral replication and disease progression. The over-activation of Tregs might result in the decrease of Tregs.</p>

Chloramphenicol improved expression of recombinant cholera toxin B subunit in Escherichia coli and its adjuvanticity / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Cholera toxin B subunit (CTB) was shown to be a potent adjuvant for protein immunogen, especially when inoculated through mucosal route. We aimed to optimize the expression approach for CTB and thereafter to determine the adjuvant effect on DNA vaccine.</p><p><b>METHODS</b>Wild type CTB coding gene was amplified and cloned into prokaryotic expression vector pET-30a, and the recombinant CTB was expressed in the presence of different concentration of chloramphenicol and isopropyl β-D-thiogalactoside. Purified recombinant CTB was mixed with HIV-1 AE2f tat-rev-integrase-vif-nef fusion gene DNA vaccine and female BALB/c mice were vaccinated with a DNA priming-recombinant vaccinia vectored vaccine boosting regimen through intramuscular injection. Interferon γ (IFN-γ) enzyme-linked immunospot (Elispot) assay was used to read out the specific T-cell immunity.</p><p><b>RESULTS</b>Chloramphenicol was essential for the efficient expression of recombinant CTB (rCTB) in pET-30a/BL21 (DE3) system and could be optimized at the concentration of 0.625 µg/ml in the presence of chloramphenicol. The purified rCTB could bind with GM1 efficiently. INF-γ Elispot data showed the T-cell response induced in CTB adjuvanted group ((734 ± 240) spot forming cells/10(6) splenocytes) was higher than that induced by non-adjuvanted ((520 ± 150) spot forming cells/10(6) splenocytes), all responses against different antigens were enhanced in parallel.</p><p><b>CONCLUSION</b>CTB could be efficiently expressed in the presence of chloramphenicol and purified CTB is functional and capable of enhancing the specific T cell responses elicited by DNA vaccine, the mechanism needs to be explored in the future.</p>

A new approach for sequencing virion genome of Chinese HIV-1 strains subtype B and BC from plasma / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Although it was widely accepted that full-length HIV genome sequences is important in studying virus genetic evolution and variation as well as developing vaccine candidate, to directly sequencing HIV-1 genome of virion RNA remains as a challenge worldwide. Up to date, no published genomic sequences from virion RNA are available for Chinese prevalent HIV-1 strains due to the absence of specialized protocol and appropriate lab equipments. In this study we developed a straightforward approach for amplifying and sequencing HIV virion RNA from plasma by modifying published protocols and further confirmed it is suitable to process Chinese samples.</p><p><b>METHODS</b>The methods for viral RNA extraction and gene amplification was modified and optimized as could be widely used in most Chinese labs. Gene alignment of Chinese HIV-1 strains was employed for designing specialized primer sets for Thai-B and BC recombinant strains. Based on comprehensively consideration of high variable gene region and recombinant breakpoints in BC recombinant strains, a three-amplicon strategy (including 4.3-kb gag-pol, 2.9-kb pol-env and 2.7-kb env-nef) was developed. In addition, one amplicon (9 kb near full-length genome) was also used in 32 samples with varied viral loads. All amplicons were directly sequenced by DNA automated sequencer.</p><p><b>RESULTS</b>Twenty-five percent (8/32) amplification efficiency was achieved by the one-amplicon strategy and 65.6% (21/32) by three-amplicon strategy. For one amplicon strategy, none of complete near full-length genome sequences was obtained by DNA sequencing. For three-amplicon strategy, 75% sequences were achieved in DNA sequencing. Amplification efficiency but not sequencing efficiency was closely associated with viral loads.</p><p><b>CONCLUSION</b>Three-amplicon strategy covering all encoding regions of HIV-1 is suitable for Thai-B and BC recombinant strains and could be potentially employed in less-well equipped Chinese labs.</p>

Establishment of human colorectal tissue model in HIV-1 mucosal infection / 中华预防医学杂志

<p><b>OBJECTIVE</b>To establish human colorectal tissue model in HIV-1 mucosal infection and by using pseudotyped virus to simulate the biological process of HIV-1 mucosal infection from HIV-1 entering into mucosa to local infection establishment.</p><p><b>METHODS</b>Tumor adjacent normal colorectal tissues were obtained with informed consent. After excised the muscularis externa, the mucosa and submucosa were dissected into the same blocks and cultured in 12-well cell culture plates. The cultured tissue structure and morphology were observed from day 0 to day 13 by staining with the hematoxylin eosin (HE), and the tissue activity was detected by 3(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The established tissues explants were infected by a single cycle replicated pseudotyped virus and propagated for 6 - 7 days, then subjected to the detection of p24 production within supernatant to verify the applicability of the model for the studying of HIV-1 mucosal infection. The applicability of the established explants for safety and reactivity evaluation of mucosa topical drugs was conducted by the using of first generation antiseptic Nonoxynol-9 (N-9) as an example.</p><p><b>RESULTS</b>HE staining showed the structure of colorectal tissue was remained well until 5(th) day and still evident until 13(th) day. The tissue activity of cultured mucosa was above 80% at day 4, and still remained over 50% at day 7 as detected by MTT assay. After infected by pseudo virus, the increased level of p24 was detected from supernatant collected on 1(st), 4(th), 8(th) day, which indicated a local infection was created. In addition, the dose changing of N-9 was reflected sensitively by the activity of this model.</p><p><b>CONCLUSION</b>Ex vivo human colorectal tissue model mimic HIV-1 mucosal infection was established that can be used to replicate the bioprocess of human HIV-1 mucosal infection.</p>

Application of propofol target controlled infusion combined with dribbled and nebulized lidocaine in tracheal intubation under spontaneous respiration / 中国医学科学院学报

<p><b>OBJECTIVE</b>To evaluate the value of propofol target-controlled infusion combined with dribbled and nebulized lidocaine in tracheal intubation under spontaneous breathing.</p><p><b>METHODS</b>Totally 40 elective surgery patients to accept tracheal intubation under unconsciousness and spontaneous breathing were randomly divided into 2 groups: 6-8 cm of endotracheal tube was inserted subglottic ally in the complete intubation group (n=20) while 3-4 cm was inserted temporarily in the partial intubation group (n=20).</p><p><b>RESULTS</b>The tracheal intubation was successfully completed under spontaneous breathing in all patients; meanwhile,the hemodynamic status was stable without any severe respiratory complications. Eleven patients suffered from moderate coughing response in the complete intubation group while no such response was noted in the partial intubation group (P<0.01).</p><p><b>CONCLUSIONS</b>Application of propofol target-controlled infusion combined with dribbled and nebulized lidocaine provides a good condition for tracheal intubation under unconsciousness and spontaneous breathing. The partial intubation can effectively prevent the occurrence of coughing response.</p>

Establishing a Th17 based mouse model for preclinical assessment of the toxicity of candidate microbicides / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>To effectively block the invasion of human immunodeficiency virus (HIV)-1 on mucosal surface, vaginal anti-HIV-1 microbicides should avoid inflammatory responses and disruption of mucosa integrity because these will facilitate transepithelial viral penetration and replication. However, existing models fail to predict and evaluate vaginal mucosal toxicity induced by microbicides, and most importantly, they are unable to identify subtle or subclinical inflammatory reactions. This study was designed to develop a cost-effective in vivo model to evaluate microbicide safety in a preclinical study which can recapitulate the mucosal topical reaction.</p><p><b>METHODS</b>A murine model was employed with nonoxynol-9 (N-9) as the topical stimulant within the vagina. Different concentrations of N-9 (1%, 3%, and 4%) were topically applied to the vagina for five consecutive days. A panel of inflammatory cytokines including interleukine-2 (IL-2), IL-4, IL-6, IL-17A, interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), and immuno-regulatory IL-10 were assayed in vaginal lavage. Cytokines were quantified by using cytometric bead array (CBA) and reverse transcript (RT) real-time PCR. Histopathological evaluation of vaginal tissues was conducted on hematoxylin-eosin stained slides and scored with a semi-quantitative system according to the severity of epithelial disruption, leucocyte infiltration, edema, and vascular injection. The association between the cytokines and histopathological scores was assessed by linear regression analysis.</p><p><b>RESULTS</b>All three concentrations of N-9 induced inflammatory cytokine production. The 4% N-9 application resulted in a consistent production of cytokines in a time-dependent manner. The cytokines reached peak expression on day three with the exception of IL-4 which reached its peak on day one. Histopathological examination of 4% N-9 treated cervicovaginal tissues on day three showed intensive damage in four mice (sores: 10 - 13) and moderate damage in one mouse (score: 8), which were significantly associated with both inflammatory cytokines IL-17A and IL-6 and anti-inflammatory cytokines IL-4 and IL-10. Interestingly, IL-17A showed significant positive association with inflammatory cytokine TNF-α (r = 0.739; P < 0.05), anti-inflammatory cytokines IL-10 (r = 0.804; P < 0.01) and IL-4 (r = 0.668; P < 0.05).</p><p><b>CONCLUSIONS</b>Our data demonstrate that a panel of cytokines (IL-17A, IL-6, IL-4 and IL-10) could be used as surrogate biomarkers to predict the histopathological damage. Th17 may play a central role in orchestrating inflammatory cytokine responses. This Th17 based mouse model is cost-effective and suitable to assess the toxicity of candidate microbicides in preclinical studies.</p>

A mouse model based on replication-competent Tiantan vaccinia expressing luciferase/HIV-1 Gag fusion protein for the evaluation of protective efficacy of HIV vaccine / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Developing an effective vaccine against human immunodeficiency virus type 1 (HIV-1) remains a grand challenge after more than two decades of intensive effort. It is partially due to the lack of suitable animal models for screening and prioritizing vaccine candidates. In this study, we aim to develop a mice model to test HIV-1 vaccine efficacy.</p><p><b>METHODS</b>We constructed a recombinant vaccinia expressing firefly luciferase and HIV-1 Gag fusion protein based on Tiantan strain, an attenuated but replication-competent poxvirus (rTTV-lucgag). By quantifying the luciferase activity as its read out, we defined the biodistribution of Tiantan strain poxvirus in mice inoculated intraperitoneally and attempted to apply this model to evaluate the HIV-1 vaccine efficacy.</p><p><b>RESULTS</b>Our data demonstrated that the rTTV-lucgag was able to express high level of luciferase (< or = 10(6) relative luciferase units (RLU)/mg protein) and HIV-1 Gag (> 3 folds increase comparing to the control). After intraperitoneal inoculation, this virus had dominant replication in the ovary, uterus, and cervix of mice and the luciferase activities in those organs are significantly correlated with viral titers (r(2) = 0.71, P < 0.01). Pre-immunization with an HIV gag DNA vaccine reduced the luciferase activity in ovary from (6006 +/- 3141) RLU/mg protein in control group to (1538 +/- 463) RLU/mg protein in vaccine group (P = 0.1969).</p><p><b>CONCLUSIONS</b>The luciferase activity in ovary could represent viral replication in vivo; this rTTV-lucgag/mice model may be suitable to assess the protective efficacy of cytotoxic T-cell responses to HIV Gag with less tedious work and high through-put.</p>

Effect of GBV-C/HIV coinfection on HIV/AIDS disease progression and HIV replication / 病毒学报

Several research groups have recently reported that persistent GB virus C (GBV-C) co-infected with human immunodeficiency virus (HIV) leads to slower AIDSs disease progression than HIV-1 infection alone. However, these findings were not confirmed by several other studies. To investigate the association between GBV-C replication and plasma HIV loads and CD4+ T cell counts, 203 HIV-1 positive former blood/plasma donors(FBDs) were enrolled from Fuyang city of Anhui Province in China. Plasma specimens were collected from them and were tested for GBV-C using RT-PCR and ELISA. Out of 203 specimens, 52 (25.6%) cases were positive for GBV-C, including 35 male (67.3%) and 17 female (32.7%) cases. No significant association was identified between GBV-C infection and CD4+ T-cell counts or between GBV-C infection and HIV viral loads. Since all the subjects studied were naive to ART, the influence of therapy on AIDS disease progression was ruled out in this study. Overall, our data indicated that HIV-1 positive male FBDs were prone to be infected, GBV-C coinfection with HIV-1 does not significantly influence HIV/AIDS disease progression during the late stage of chronic HIV-1 infection.

Enhancement of DNA vaccine-induced immune responses by a 72-bp element from SV40 enhancer / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Although DNA vaccine is considered as the next generation of vaccine, most DNA vaccine candidates are still suffering from the relatively weak immunogenicity despite the increased dosage of plasmid DNA administered. In order to enhance the immune responses elicited by a codon-optimized HIV gag DNA vaccine, a modified plasmid vector pDRVI1.0 and a booster immunization with replicating Tiantan vaccinia (RTV) strain expressing the same gene were employed.</p><p><b>METHODS</b>Vector pDRVI1.0 was constructed through inserting the 72-bp element from the SV40 enhancer, which was reported promoting nuclear transport of plasmid DNA, to the upstream of cytomegalovirus enhancer/promoter region of the plasmid vector pVR1012. Gene expression levels from expression plasmids based on pDRVI1.0 and pVR1012 were tested. Humoral and cellular immune responses induced by DNA vaccine alone or DNA prime-RTV boost regimen were determined in mice.</p><p><b>RESULTS</b>It was shown that the 72-bp element significantly enhanced the gene expression level in non-dividing cells. gag-specific humoral and cellular immune responses induced by DNA vaccination were both significantly improved, while the Th1/Th2 balance was not obviously affected by the 72-bp element. RTV boosting further significantly enhanced DNA vaccine-primed antibody and T cell responses in a Th1-biased manner.</p><p><b>CONCLUSIONS</b>The 72-bp SV40 enhancer element should be included in the DNA vaccine vector and RTV strain is a very efficient live vector for boosting immunization.</p>

Protective endotracheal intubation to reduce endotracheal bacterial contamination / 中国医学科学院学报

<p><b>OBJECTIVE</b>To initially observe the effect of classical endotracheal intubation on endotracheal bacterial contamination and evaluate the validity of protective endotracheal intubation on reducing endotracheal bacterial contamination.</p><p><b>METHODS</b>Ninety elective patients undergoing general anesthesia for hysterectomy were randomly assigned to two equal groups. Group II received endotracheal intubation protected by sterilized transparent sleeve while group I correspondingly adopted unprotective classical endotracheal intubation. Endotracheal swab sampling and bacterial counting were performed on the principle of aseptic processing before endotracheal intubation and extubation, respectively.</p><p><b>RESULTS</b>Bacteria were found in 62 of 180 samples. The difference of bacterial counting between before extubation and before intubation was (-0.3 +/- 35.6) 100 CFU/ ml in group II, lower than that in group I, which was (21.4 +/- 56.7) 100 CFU/ml (P<0.05).</p><p><b>CONCLUSION</b>Endotracheal bacterial contamination may be caused by unprotective classical endotracheal intubation and could be reduced by protective endotracheal intubation.</p>

Epidemiology, clinical and laboratory characteristics of currently alive HIV-1 infected former blood donors naive to antiretroviral therapy in Anhui Province, China / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Unregulated commercial blood/plasma collection among farmers occurred between 1992 and 1995 in central China and caused the second major epidemic of human immunodeficiency virus type 1 (HIV-1) infection in China. It is important to characterize HIV-1-infected former blood donors and to study characteristics associated with disease progression for future clinical intervention and vaccine development.</p><p><b>METHODS</b>A cross-sectional study was performed on HIV-1-infected former blood donors (FBDs) and age-matched HIV-seronegative local residents. Demographic, epidemiologic, clinical and key laboratory data were collected from all study participants. Both unadjusted and adjusted multivariate linear regressions were employed to analyze the association of the decrease of CD4(+) T-cell counts with other characteristics.</p><p><b>RESULTS</b>Two hundred and ninety-four HIV-1-infected FBDs and 59 age-matched HIV-seronegative local residents were enrolled in this study. The unregulated blood/plasma collection occurred more than a decade (10.8 - 12.8 years) ago, which caused the rapid spread of HIV-1 infection and the high prevalence of co-infection with hepatitis C virus (HCV, 89.5%); hepatitis B virus (HBV) co-infection was observed in only 11 HIV(+)participants (3.7%). Deterioration in both clinical manifestation and laboratory parameters and increase of viral loads were observed in parallel with the decrease of CD4(+) T-cell counts. The decrease of total lymphocyte counts (P < 0.001) and hemoglobin levels (P < 0.001) and the appearance of dermatosis (P = 0.03) were observed in parallel with the decrease of CD4(+) T-cell counts whereas viral loads (P < 0.001) and CD8(+) T-cell counts (P = 0.01) were inversely associated with CD4(+) T-cell counts.</p><p><b>CONCLUSIONS</b>Co-infection with HCV but not HBV is highly prevalent among HIV-1-infected FBDs. CD4(+) T-cell counts is a reliable indicator for disease progression among FBDs. Total lymphocyte counts, hemoglobin level and appearance of dermatosis were positively associated with CD8(+) T-cell counts and viral loads were inversely associated with the decreased CD4(+) T-cell counts.</p>

HIV-specific T cell immunity across the entire HIV genome in Chinese men who have sex with men / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Man who has sex with man (MSM) is one of the high risk groups for spreading HIV/AIDS. It was reported that the most prevalent human immunodeficiency virus type 1 (HIV-1) strain among MSM is subtype B; however, T cell immunity remains unknown across the HIV-1 B genome in this population.</p><p><b>METHODS</b>Using Elispot assay with synthetic peptides spanning the sequence of HIV-1 consensus B, HIV-1-specific cytotoxic T-cell lymphocyte responses were quantified among 3 treated and 19 untreated HIV-1 infected MSM from Beijing, China. Cross-sectional association between viral loads and cellular immune responses were analyzed.</p><p><b>RESULTS</b>Peptide pools corresponding to each HIV-1 protein were used for Env, Gag, Pol, Nef, Tat/Rev, Vpr/Vpu and Vif. The results showed that the magnitude of T cell responses in the 3 treated HIV(+) MSM group [median, 770 spot forming cells (SFCs) per 10(6) peripheral blood mononuclear cells (PBMCs)] might be significantly lower than that in the 19 untreated HIV(+) MSM group (median, 6175 SFCs per 10(6) PBMCs). Nef, Gag and Pol are the most frequently targeted HIV-1 antigens; and 16 subjects (73%) were identified with vigorous T cell immunity against each of these three proteins. The overall magnitude of T cell immunity closely related to its breadth (r = 0.72, P < 0.05) and was inversely but weakly associated with viral loads (r = -0.15). Further analysis showed that both Gag (r = -0.24) and Pol specific T cells (r = -0.12) contributed to this inverse association whereas Nef specific T cells showed no association with viral loads.</p><p><b>CONCLUSIONS</b>The magnitude of HIV-1 specific T cells is inversely but weakly associated with viral loads among MSM; HIV-specific T cell responses against conservative sequences (Gag and Pol) are the main contributors to this association among Chinese HIV(+) MSM. These findings have important implications for vaccine design.</p>

Identification of HIV-1 specific T lymphocyte responses in highly exposed persistently seronegative Chinese / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Studies of highly exposed persistently seronegative (HEPS) individuals may provide valuable information on mechanisms of protection and on vaccine design. Cellular immune responses play a critical role in containing human immunodeficiency virus. However, the cellular immune responses in HEPS individuals have not been thoroughly assessed at the entire viral genome level.</p><p><b>METHODS</b>Ten HEPS Chinese with a history of frequent penetrative vaginal intercourse (mean frequency, at least once a week), with some unprotected sexual contact occurring in the weeks or days immediately before enrollment, 25 HIV-1 seropositive individuals, 10 HIV-1-seronegative healthy individuals with low-risk sexual behavior and no history suggestive of exposure to HIV-1 infection were enrolled. HIV-1-specific T cell responses were comprehensively analyzed by an interferon-gamma Elispot assay against 770 overlapping peptides spanning all HIV-1 proteins.</p><p><b>RESULTS</b>HIV-1-specific T-cell responses of interferon-gamma secretion were identified in 3 (30%) out of 10 HEPS individuals; the specific cytotoxic T lymphocytes were targeted at Pol (2/10), Env (2/10), and Tat (1/10). HIV-1-specific T-cell responses of interferon-gamma secretion were identified in 20 (80%) out of 25 seropositive intravenous drug users (IDUs), revealing that all HIV-1 proteins and protein subunits could serve as targets for HIV-1-specific CD8(+) T cell responses with 85% recognizing Gag, 80% recognizing Nef, 75% recognizing Pol, 60% recognizing Env, 55% recognizing Vpu, 45% recognizing Vpr, 20% recognizing Vif, 20% recognizing Tat and 15% recognizing Rev in these seropositive individuals. None of the seronegative healthy individuals gave the positive T-cell responses.</p><p><b>CONCLUSIONS</b>About 30% of HEPS Chinese mounted HIV-1 specific T cell immune responses. Cell-mediated immunity against HIV-1 may be developed through non-productive infections.</p>

CD4+ T cell-mediated presentation of non-infectious HIV-1 virion antigens to HIV-specific CD8+ T cells / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The mechanism of chronic immune activation and impairment of HIV-specific immune responses during chronic infection is not fully understood. However, it is known that high immune activation leads to more rapid progression to AIDS. We hypothesize that CD4(+) T cell-mediated viral antigen presentation contributes to this pathologic immune activation in HIV-infected individuals.</p><p><b>METHODS</b>HIV-specific T cells, responding to noninfectious HIV-1 virions as antigen, were measured by flow cytometric assays. These experimental conditions reflect the in vivo condition where noninfectious HIV-1 represents more than 99% of the antigens.</p><p><b>RESULTS</b>CD4(+) T cells purified from HIV-infected individuals were capable of cross presenting exogenous noninfectious HIV-1 virions to HIV-1-specific CD8(+) T cells. Cross presentation required the entry of HIV-1 to CD4(+) T cells and antigen translocation from endoplasmic reticulum to the Golgi complex. Blocking CD4(+) mediated activation of HIV-specific CD8(+) T cells and redirecting the viral antigens to antigen presenting cells improved HIV-specific T cell responses.</p><p><b>CONCLUSIONS</b>One possible cause of chronic immune activation and impairment of HIV-1 specific T cell responses is represented by HIV-1 harboring CD4(+) T cells cross presenting HIV-1 antigen to activate CD8(+) T cells. This new mechanism provides the first evidence that cross presentation of noninfectious HIV-1 virions play a role in the immunopathogenesis of HIV-1 infection.</p>