Research progress in treatment of tuberculous meningitis / 中华临床感染病杂志

Tuberculous meningitis is the most common and serious type of central nervous system tuberculosis, with high mortality and disability rate, which has attracted extensive attention of global public health. The high mortality rate and disability rate of tuberculosis meningitis may be related to its lack of specific clinical and imaging characteristics, insufficient attention from clinicians, lack of early sensitive and specific diagnostic testing techniques, delay in treatment, and restricted penetration of anti-TB drugs into the blood-brain barrier or/and MDR-TB, etc. This article reviews the disease burden of TBM, chemotherapy drugs and regimens, anti-inflammatory agents, aspirin, interventional and surgical treatment to provide reference for clinical management of this disease.

Analysis of drug-resistant mutations in human immunodeficiency virus-1 infected patients in Chongqing City from 2014 to 2018 / 中华传染病杂志

Objective:To investigate the drug-resistant mutations of human immunodeficiency virus-1 (HIV-1) in patients who received highly active antiretroviral therapy (HAART) from 2014 to 2018.Methods:A total of 880 patients with HIV-1 infection who had been treated with HAART for more than six months in Chongqing Infectious Disease Medical Center from May 2014 to December 2018 were enrolled. Plasma samples were collected, and one-step reverse transcription-polymerase chain reaction (PCR) and nested PCR were taken to amplify protease and reverse transcriptase regions of HIV-1 pol gene region. The obtained amplified nucleotide sequences were compared with the drug resistance database for antiviral drug resistance analysis. Viral genotyping tool software was used to analyze HIV-1 subtype distribution. The categorical variables were compared using chi-square test. Results:Among 880 patients, the plasma HIV-1 viral load was (4.12±0.63) lg copies/mL, the CD4 + T lymphocyte count was (251±124)/μL, and the median duration of antiviral therapy was 26 months. In the subtypes analysis, the circulating recombinant form (CRF) 01-AE subtype was the largest proportion of HIV-1 subtypes, accounting for 38.9%(342/880), and the CRF07-BC subtype accounted for 28.5%(251/880), B+ C subtypes accounted for 16.2%(143/880). Drug-resistant mutations were detected in 534 patients, with a total drug resistance rate of 60.7%. The drug resistance rates of nucleoside reverse transcriptase inhibitors (NRTI), non-nucleoside reverse transcriptase inhibitors (NNRTI) and protease inhibitors (PI) were 51.0%(449/880), 58.6%(516/880) and 1.7%(15/880), respectively. The drug resistances to lamivudine, emtricitabine, efavirenz, and nevirapine were serious, and the medium/high resistance rates were 46.8%(412/880), 46.8%(412/880), 51.3%(451/880), and 53.6%(472/880), respectively, while those to zidomidudine (6.0%, 53/880), etravirin (9.0%, 451/880) and PI were not serious. M184IV (47.3%), K65R (22.2%) and K70RE (12.6%) were the most frequent mutations for NRTI. K103NS (25.1%), V106A (19.7%) and V179DE (14.4%) were the most frequent mutations for NNRTI. The most common drug-resistant mutations for PI were L10FIV (7.4%) and A71IVT (6.5%). The drug resistance rate of CRF01-AE subtype (69.3%, 237/342) was higher than those of CRF07-BC subtype (49.8%, 125/251) and B+ C subtype (51.0%, 73/143), the differences were statistically significant ( χ2=22.6 and 14.6, respectively, both P<0.05). Conclusions:The incidence of drug resistance is high among HIV-1 infected patients after six-month HAART treatment in Chongqing City. The drug resistance to NNRTI is the most common, followed by NRTI, while PI is less resistant. Drug resistance is the main reason for the virological breakthrough in HIV-1 infected patients.

Variable fragment of heavy chain antibody against the terminal protein region of hepatitis B virus polymerase introduced by Tat protein transduction domain inhibits the replication of hepatitis B virus in vitro / 中华传染病杂志

Objective To study a functional variable fragment of heavy chain(VH)antibody against the terminal protein(TP)region of hepatitis B virus(HBV)polymerase introduced by human immunodeficiency virus Tat protein transduction domain(TAT)and the inhibitive activity of TAT-VH on the replication of HBV in vitro.Methods The gene encoding TAT-VH was cloned into prokaryotic expression vector pET28a(+).Recombinant plasmid was transduced into E coli BL21(DE3)LysS,then the protein was expressed and purified.The purified TAT-VH fusion protein was added into HepG2.2.15 cell culture.The transduction efficiency was evaluated by indirect fluorescence assay(IFA).The cytotoxicity of TAT-VH was detected by Methabenzthiazuron(MTT)assay.HBV DNA level in HepG2.2.15 cell culture was measured using quantitative polymerase chain reaction(PCR).The data were analyzed by one-factor analysis of variance and t test.Results TAT-VH fusion protein was successfully expressed and purified.It was confirmed by IFA and MTT assay that TAT-VH was introduced into HepG2.2.15 cells and the cell growth was not affected.The level of HBV DNA in supernatant of HeDG2.2.15 cell culture with 5 000 nmol/L TAT-VH was(1.211±0.132)lg copy/mL,which was significantly lower than control group[(5.325±0.041)lg copy/mL,t=72.91,P＜0.05].Meanwhile,the level of intracellular HBV DNA was(3.521±0.411)lg copy/mL,which was significantly lower than control group[(8.532±0.132)lg copy/mL.t=28.41,P＜0.05].Conclusion The HBV replication is inhibited by anti-TP TAT-VH antibodies in vitro,which provides valuable experimemal basis for developing therapy of HBV infection with intracellular antibody.

Screening of LoxP-positive recombinant clones by self-primer colony polymerase chain reaction / 中华检验医学杂志

Objective To investigate the screening and evaluating methods of positive recombinant clones for small fragments such as LoxP sequence. Methods Synthesized LoxP and vector complementary sequence were used as the upper and lower primer respectively, and colonies were used directly as the templates of polymerase chain reaction (PCR). The presence of 784 bp strap in electrophoresis was seen as positive. The positive recombinant clones screened by PCR were evaluated contrastively by restriction endonuclease digestion and verified by DNA sequence analysis. Results Among the six colonies randomly screened by PCR, three showed positive straps and one was verified by DNA sequence analysis. However, the electrophoresis only showed unclear and clouding straps when the three positive recombinant clones were evaluated by restriction endonuclease digestion. Conclusion Self-primer colony PCR is a high-speed, convenient, economic and effective method for screening and evaluating of positive clones recombinated by small fragments such as LoxP sequence.

Establishment and optimization of rat models for hepatic oval cells proliferation / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To establish a rat model for hepatic oval cell proliferation and to observe the relationship between 2-acetaminofluorene (AAF) dosage and oval cell proliferation in the rat liver.</p><p><b>METHODS</b>Male Wistar rats weighing 150 g received daily oral gavage of AAF for 4 days before operation and up to 7 days after operation. Two-thirds hepatectomy was performed on the 5th day and the gavage was not performed on the day of operation. AFF was given with the dosage of 2.5 mg/kg, 5 mg/kg, 10 mg/kg, 15 mg/kg, and 20 mg/kg body weight. Animals in control group were given saline. Three rats from each group were killed every 2~3 days after hepatectomy and liver slices were fixed and processed for routine histology and immunohistochemistry.</p><p><b>RESULTS</b>Hepatic oval cells were not observed in the liver of controls and only a few were detected in the liver of 2.5 mg/kg and 5 mg/kg groups. However, obvious oval cell proliferation was seen in the liver of 10 mg/kg, 15 mg/kg, and 20 mg/kg groups. Hepatic oval cells were stained positive for cytokeratin 19, OV6, vimentin and proliferating cell nuclear antigen (PCNA).</p><p><b>CONCLUSIONS</b>Satisfactory rat models for hepatic oval cell proliferation can be obtained using our scheme when AAF is dosed at 10~20 mg/kg body weight.</p>