[Application of limiting antigen avidity enzyme immunoassay for estimating HIV-1 incidence in men who have sex with men].

Objective: To estimate the incidence of HIV-1 infection in men who have sex with men (MSM) in key areas of China through HIV-1 limiting antigen avidity enzyme immunoassay (LAg-Avidity EIA), analyze the deviation from the actual results and identify influencing factors, and provided reference for improving the accuracy of estimation results. Methods: Based on the principle of the cohort randomized study design, 20 cities were selected in China based on population size and the number of HIV-positive MSM. The sample size was estimated to be 700 according to the HIV-1 infection rate in MSM. MSM mobile phone app. was used to establish a detection appointment and questionnaire system, and the baseline cross-sectional survey was conducted from April to November 2019. LAg-Avidity EIA was used to identify the recent infected samples. The incidence of HIV-1 infection was calculated and then adjusted based on the estimation formula designed by WHO. The influencing factors were identified by analyzing the sample collection and detection processes. Results: Among the 10 650 blood samples from the participants, 799 were HIV-positive in initial screening, in which 198 samples (24.78%) missed during confirmation test. Only 621 samples were received by the laboratory. After excluding misreported samples, 520 samples were qualified for testing. A total of 155 samples were eventually determined as recent infection through LAg-Avidity EIA; Based on the estimation formula , the incidence of HIV-1 infection in MSM in 20 cities was 4.06% (95%CI:3.27%-4.85%), it increased to 5.53% (95%CI: 4.45%-6.60%)after the adjusting for sample missing rate. When the sample missing rate and misreporting rate were both adjusted, the incidence of HIV-1 infection in the MSM increased to 5.66% (95%CI:4.67%-6.65%). The actual incidence of HIV-1 infection in MSM in the 20 cities might be between 4.06% and 5.66%. Conclusions: Sample missing and misreporting might cause the deviation of the estimation of HIV-1 infection incidence. It is important to ensure the sample source and the quality of sample collection and detection to reduce the deviation in the estimation of HIV-1 infection incidence.

Analysis of correlations between coronary heart disease and haplotypes of the angiotensin II receptor type 1 (AGTR1) gene.

This study aimed to explore correlations between haplotypes of the angiotensin II receptor type 1 (AGTR1) gene and coronary heart disease (CHD). In total, 204 patients with CHD and 206 healthy controls were genotyped using denaturing high-performance liquid chromatography between 2008 and 2014. Five polymorphic loci were found, namely, A-43281G, A-32954G, G-32839A, G-11064A, and A1880G. Likelihood estimates were used to identify haplotypes consisting of the A1166C locus and four of these five loci, then correlations between these haplotypes and CHD were assessed. Eight haplotypes with a frequency greater than 3% in the study population were discerned: ACCAA [odds ratio (OR) = 1.2381, 95% confidence interval (CI) = 0.7726-1.9843]; ACCCA (OR = 1.2604, 95%CI = 0.6104-2.6027); ACTAA (OR = 0.8929, 95%CI = 0.6607-1.2067); ACTAG (OR = 0.9274, 95%CI = 0.5692-1.5110); ATTAA (OR = 1.0347, 95%CI = 0.7505-1.4265); ATTAG (OR = 0.9110, 95%CI = 0.4227-1.9631); GCCAA (OR = 1.1273, 95%CI = 0.7259-1.7506); and GCTAA (OR = 0.7981, 95%CI = 0.4379-1.4546). However, the frequency of these haplotypes did not significantly differ between CHD and the control groups. Thus, no correlation was established between the occurrence of CHD and AGTR1 haplotypes present at frequencies greater than 3%.

Sequence preservation of the third exon of the bcl-2 gene in non-Hodgkin's lymphoma: absence of somatic hypermutation.

The t(14;18) translocation juxtaposes the bcl-2 gene on chromosome 18 to a joining (J) gene segment of the immunoglobulin heavy chain gene (IgH) on chromosome 14. Up to 85% of non-Hodgkin's lymphomas (NHL) are t(14;18) positive. Recent reports have documented point mutations in the second exon of translocated bcl-2 alleles and postulated that immunoglobulin variable (V) region somatic hypermutation, related to Ig sequences approximately 250 Kb downstream, may be mediating these mutations. We have examined the third exon of bcl-2, directly adjacent to Ig sequences in the t(14;18), for point mutations. In particular, we studied the translated region of exon 3 in 45 NHLs by SSCP analysis and failed to detect a single point mutation. Further, we sequenced eleven t(14;18) breakpoints, including both bcl-2 and JH sequences, and detected only one point mutation, in a JH-derived sequence. We conclude that immunoglobulin V region somatic hypermutation does not induce point mutations into the t(14;18) breakpoint region or into the translated region of the third exon of bcl-2 alleles involved in the t(14;18) translocation, conserving the membrane insertion properties of the carboxyl tail of this protein.

Alterations of the p53 tumor suppressor gene in diffuse large cell lymphomas with translocations of the c-MYC and BCL-2 proto-oncogenes.

Diffuse large cell lymphomas are aggressive tumors of B-cell origin. In some cases they arise from low-grade follicular lymphomas carrying the t(14;18) translocation, an event that leads to the overexpression of the BCL-2 gene product. More frequently, however, they lack the t(14;18) translocation. Rearrangements of the c-MYC proto-oncogene and mutations of the p53 tumor suppressor gene have also been documented in these lymphomas. This study examines the extent to which alterations in the BCL-2, c-MYC, and p53 genes co-exist within individual lymphomas. Eight diffuse large cell lymphoma cell lines and 11 diffuse large cell lymphoma tumors were assessed for genetic alterations in these three genes. Our results indicate that there is a heterogeneity in the oncogene/suppressor gene profile among diffuse large cell lymphomas. Two cell lines and one tumor carried alterations in all three genes, one cell line carried alterations of c-MYC and p53, and one primary tumor and one cell line carried p53 mutations and the t(14;18). Single alterations of BCL-2 and p53 were also observed. Another cell line had no alterations in any of these genes. The heterogeneity indicates that varied mechanisms may be involved in the generation of diffuse large cell lymphomas.