Rapid evaluation of PHD2 inhibitory activity of natural products based on capillary electrophoresis online stacking strategy.

Prolyl hydroxylase domain 2 (PHD2) is an important enzyme in the human body that perceives changes in oxygen concentration and regulates response in hypoxic environments. Evaluation of PHD2 inhibitory activity of natural products is crucial for drug development of hypoxia related diseases. At present, the detection of low concentration of α-ketoglutaric acid (the substrate of PHD2 enzymatic reaction) requires derivatization reactions or sample pretreatment, which undoubtedly increases the workload of PHD2 inhibitory activity evaluation. In this paper, a direct detection approach of α-ketoglutaric acid was established by using the online stacking strategy of capillary electrophoresis to evaluate the PHD2 inhibitory activity of natural products. Under optimized conditions, detection of a single sample can be achieved within 2 min. By calculation, the intraday precision RSD of the apparent electrophoretic mobility and peak areas of α-ketoglutaric acid are 0.92 % and 0.79 %, respectively, and the interday RSD were 1.27 % and 0.96 % respectively. The recoveries of the present approach were 97.9-105.2 %, and the LOQ and LOD were 2.0 µM and 5.0 µM, respectively. Furthermore, this approach was applied for the evaluation of inhibitory activity of PHD2 for 13 natural products, and PHD2 inhibitory activity of salvianolic acid A was firstly reported. The present work not only realizes evaluation of PHD2 inhibitory activity through direct detection of α-ketoglutaric acid, but also provides technical support for the discovery of potential drug molecules in hypoxia related diseases.

Alkylamides from Zanthoxylum armatum DC. and their neuroprotective activity.

Zanthoxylum armatum DC. is an important medicinal plant, and its pericarps are commonly used as a natural spice in Asian countries. In this study, fifteen alkylamides were isolated and elucidated from the pericarps of Z. armatum, including five undescribed alkylamides (1-5) and ten known compounds (6-15). The molecular structures of all compounds were elucidated by 1D and 2D NMR spectroscopic analysis and mass spectrometry, among which the absolute configuration of compound 15 was determined by the Mo2(OAc)4-induced circular dichroism method. Moreover, all compounds were screened for their neuroprotective activity against H2O2-induced oxidative stress in human neuroblastoma SH-SY5Y cells for the evaluation of their neuroprotective activity. Especially, compounds 2-4 expressed potential neuroprotective activity, and further research showed that the cell viability was significantly enhanced in a concentration dependent manner when the cells were treated for 6 h. Moreover, compounds 2-4 could decrease reactive oxygen species accumulation. This paper enriched structure types of alkylamides in Zanthoxylum armatum.

Potential Anti-Tumor Activity of Nardoguaianone L Isolated from Nardostachys jatamansi DC. in SW1990 Cells.

Natural products (NPs) were a rich source of diverse bioactive molecules. Most anti-tumor agents were built on natural scaffolds. Nardostachys jatamansi DC. was an important plant used to process the traditional Chinese herbal medicines "gansong". Pancreatic cancer was the fourth most common cause of cancer-related death in the world. Hence, there was an urgent need to develop novel agents for the treatment of pancreatic cancer. In this paper, nardoguaianone L (G-6) is isolated from N. jatamansi, which inhibited SW1990 cells colony formation and cell migration, and induced cell apoptosis. Furthermore, we analyzed the differential expression proteins after treatment with G-6 in SW1990 cells by using iTRAQ/TMT-based quantitative proteomics technology, and the results showed that G-6 regulated 143 proteins' differential expression by GO annotation, including biological process, cellular component, and molecular function. Meanwhile, KEGG enrichment found that with Human T-cell leukemia virus, one infection was the most highly enhanced pathway. Furthermore, the MET/PTEN/TGF-ß pathway was identified as a significant pathway that had important biological functions, including cell migration and motility by PPI network analysis in SW1990 cells. Taken together, our study found that G-6 is a potential anti-pancreatic cancer agent with regulation of MET/PTEN/TGF-ß pathway.

Fluorometric assay based on the in situ formation of silicon nanoparticles for the determination of ß-glucuronidase.

As a prodrug-converting enzyme, ß-glucuronidase (ß-GCase) is a lysosomal enzyme participating in the release of glucose from glucopyranosyl glycoside. In this work, for the first time, we have developed an analytical method exhibiting fluorometric signals for straightforward determination of ß-GCase using silicon nanoparticles (Si NPs). Via hydrothermal treatment, in the water bath of 70 °C for 50 min, dopamine (DA) reacts with (3-[2-(2-aminoethylamino) ethylamino] propyltrimethoxysilane) (AEEA) to produce green fluorescent Si NPs. Enlightened by such easy reaction and ß-GCase-triggered specific hydrolysis of dopamine-4-ß-D-glucuronide (DA-GCU) into DA, we have designed an analytical method for ß-GCase sensing through the production of Si NPs. Therefore, through the designed sensing platform, ß-GCase activity was monitored, and the limit of detection (LOD) for this study was 0.02 U/L. Furthermore, the feasibility of the method was assessed by measuring ß-GCase activity in human serum where recoveries and RSD were in the ranges 99-104% and 1.37-3.44, respectively.

Gypenosides (GPs) alleviates hypoxia-induced injury in PC12 cells and enhances tolerance to anoxia in C57BL/6 mice.

Oxygen is a necessary substance for life activities, but reduced oxygen utilization due to high altitude exposure and respiratory dysfunction diseases could lead to pathological changes in the organisms. Herein gypenosides, the active ingredients in the food and medicine resource plant Gynostemma pentaphyllum (Thunb.) Makino were found to alleviate hypoxia-induced injury in PC12 cells. Moreover, hypoxia induced an increase in Ca2+ and reactive oxygen species content, and such patterns were both significantly reduced by gypenosides treatment. At the same time, gypenosides significantly blocked the decrease of both NO content and mitochondrial membrane potential caused by hypoxia. Furthermore, gypenosides gavage treatment significantly prolonged the survival time of C57BL/6 mice in confinement up to 24.3% and enhanced the locomotor ability of mice. Therefore, gypenosides have good neuroprotective effects and hypoxia tolerance activity and have the prospect of being developed as a preventive and therapeutic drug for hypoxia-related diseases. PRACTICAL APPLICATIONS: Gypenosides can enhance tolerance of cells and mice to hypoxia and have the potential to be developed into hypoxia-resistant health food and drugs.

Chemical constituents from the roots of Zanthoxylum bungeanum Maxim. and their neuroprotective activities.

Twenty-two isolates, including two previously undescribed compounds identified as benzoyltembamide (1) and P-benzoyphenethyl anisate (21), were isolated and identified from a methanol extract of the roots of Zanthoxylum bungeanum Maxim. (Rutaceae) using diverse chromatographic materials and pre-HPLC. Their structures were elucidated on the basis of spectroscopic and spectrometric data analysis such as HR-ESI-MS, 1D and 2D NMR, IR and UV, as well as single-crystal X-ray diffraction for crystalline compounds. All the compounds (except for compound 16) were isolated from the roots of Z. bungeanum for the first time. Selected compounds were evaluated for their antioxidant activities. Compound 18 attenuated the H2O2-induced cytotoxicity and blocked the accumulation of ROS in SH-SY5Y cells, and exhibited potent neuroprotective activity.

Screening of prolyl hydroxylase 2 inhibitors based on quantitative strategy of peptides.

Prolyl hydroxylase 2 (PHD2) is a key oxygen receptor regulating oxygen homeostasis in human body, and it is one of the important targets for drug research and development of hypoxia related diseases. In PHD2 enzymatic reaction, the structure of substrate (HIF-1α556-574) and product (hydroxylated HIF-1α) peptide only differ from one oxygen atom (MW>2000), which makes it a great challenge to separate them accurately and efficiently. In this work, the direct separation and detection of HIF-1α and hydroxylated HIF-1α has been firstly reported based on micellar electrokinetic chromatography (MEKC). Under optimized conditions, the intraday RSD of peak area and apparent electrophoretic mobility of hydroxylated HIF-1α were 1.87% and 0.81% respectively, and the interday RSD were 2.01% and 1.03% respectively. The LOD and LOQ of the MEKC method were 10 µM and 50 µM respectively, and the recoveries was 98.42-105.38%. Subsequently, the feasibility and accuracy of MEKC method to screen PHD2 inhibitors were confirmed by using roxadustat, and the IC50 (10.36 µM) and inhibitor type (competitive) were consistent with literature. Finally, the method was used to screen the PHD2 inhibitory activity of five traditional Chinese medicines (TCMs). The present work not only overcomes the difficulties of direct quantitative detection of hydroxylated HIF-1α, but also provides technical support for exploring and discovering new drug leads for hypoxia-related diseases from complex matrix such as TCMs.

The gut microbiome contributes to splenomegaly and tissue inflammation in a murine model of primary biliary cholangitis.

Background: Splenomegaly is not just a consequence of numerous chronic and acute conditions but may also contribute to their severity, due to the interaction of the spleen with the gut microbiome. This study aimed to explore the effect of the gut microbiome on splenomegaly. Methods: We used p40-/-IL-2Rα-/- mice as a murine model of primary biliary cholangitis (PBC) as per our previous study. Splenomegaly was evaluated by spleen weight. Severity of liver inflammation was evaluated by hepatic mononuclear cell (MNCs) number and pathological score. Changes of immune cells in the spleen and liver were detected by flow cytometry. The effects of the gut microbiome on splenomegaly and liver inflammation were observed by combined antibiotic treatment in p40-/-IL-2Rα-/- mice. Results: A proportion of p40-/-IL-2Rα-/- mice developed splenomegaly. The results revealed that liver mononuclear cells infiltration, histological scores of hepatic inflammation, and bile duct damage were positively correlated with the degree of splenomegaly. Hepatic CD4+ and CD8+ T cells numbers were significantly higher in mice with splenomegaly, and this was particularly observed in activated effector memory CD4+ T and CD8+ T cells. A proportion of some other immune cells including granulocytes, B, natural killer (NK), and CD8+ T effector memory cells were also altered in the enlarged spleen. More importantly, administration of quadruple antibiotics to deplete gut microbiota relieved the splenomegaly of p40-/-IL-2Rα-/- mice, significantly alleviated liver inflammation, and caused a significant reduction of liver and spleen T cell accumulation and activation; however, single antibiotics did not induce these changes. Conclusions: Splenomegaly was associated with more severe liver inflammation in our PBC murine model, and this effect was reversed by quadruple antibiotic treatment.

GP-14 protects against severe hypoxia-induced neuronal injury through the AKT and ERK pathways and its induced transcriptome profiling alteration.

Gypenosides are major bioactive ingredients of G. pentaphyllum. In our previous study, we found that gypenosides had neuroprotective effects against hypoxia-induced injury. In the current study, we focused on the protective effects of gypenoside-14 (GP-14), which is one of the newly identified bioactive components, on neuronal injury caused by severe hypoxia (0.3% O2). The results showed that GP-14 pretreatment alleviated the cell viability damage and apoptosis induced by hypoxia in PC12 cells. Moreover, GP-14 pretreatment also attenuated primary neuron injuries under hypoxic conditions. Additionally, GP-14 pretreatment significantly ameliorated neuronal damage in the hippocampal region induced by high-altitude cerebral edema (HACE). At the molecular level, GP-14 pretreatment reversed the decreased activities of the AKT and ERK signaling pathways caused by hypoxia in PC12 cells and primary neurons. To comprehensively explore the possible mechanisms, transcriptome sequencing was conducted, and these results indicated that GP-14 could alter the transcriptional profiles of primary neuron. Taken together, our results suggest that GP-14 acts as a neuroprotective agent to protect against neuronal damage induced by severe hypoxia and it is a promising compound for the development of neuroprotective drugs.

A highly sensitive colorimetric sensing platform based on silver nanocomposites for alkaline phosphatase.

Alkaline phosphatase (ALP) plays significant roles in regulating intracellular processes and is an important biomarker connected to several diseases. In this work, one facile and sensitive sensing platform based on CQD-silver nanocomposites (CQD-silver NPs) for colorimetric detection of alkaline phosphatase (ALP) was introduced. ALP triggers the removal of the phosphate group of ascorbic acid 2-phosphate (AA2P), which is then transformed into ascorbic acid (AA). The as-obtained AA can easily cause significant aggregation of monodispersed NPs and cause the system color to turn from bright yellow to gray. Based on the color change of the ratio of 490 nm/630 nm, ALP was sensitively and selectively detected. Under the optimum, the established method showed linearity for ALP in the range of 0.1-50 U L-1 and the detection limit was low at 0.035 U L-1, and it was subjected to ALP inhibitor screening from goji berry extract. These results indicated that the colorimetric system can be used as a simple tool for visual and fast evaluation of ALP activity as well as providing an alternative to screen ALP inhibitors.

Terpenoids from Nardostachys jatamansi and their cytotoxic activity against human pancreatic cancer cell lines.

Five previously unreported terpenoids, together with fifteen known analogs, were isolated from a methanol extract of the roots and rhizomes of Nardostachys jatamansi. Their structures, including absolute configurations, were elucidated by spectroscopic data and electronic circular dichroism (ECD) spectra analyses, as well as single-crystal X-ray diffraction for crystalline compounds. Structurally, (4R,5S,6S,7R)-1(10)-aristolane-8,9-diacid is a novel 8,9-dicarboxylic acid derivative of aristolane-type sesquiterpenoid. (4R,6S,7R,10S)-10-Hydroxyguaia-1(5)-6,7-epoxy-2-one is an undescribed analogue of nardoguaianone K, with a rare 6,7-epoxide group. (4R,5R,6R,8R)-1(10)-Isonardosinone-8-ol-9-one-7,11-lactone is an isonardosinane-type sesquiterpene bearing a γ-lactone ring. Dinardokanshone F is a rare example of a sesquiterpene dimer from N. jatamansi connected by an oxo bridge. The isolates were evaluated for their cytotoxic activity against four human pancreatic cancer cell lines (CFPAC-1, PANC-1, CAPAN-2 and SW1990). Compound epoxynardosinone exhibited significant cytotoxicity against CAPAN-2 cell lines with IC50 value of 2.60 ± 1.85 µM. 1-Hydroxylaristolone displayed comparable cytotoxicity on CFPAC-1 cell lines (IC50 1.12 ± 1.19 µM), compared to Taxol (IC50 0.32 ± 0.13 µM). 1-Hydroxylaristolone, 1(10)-aristolane-9ß-ol, 1(10)-aristolen-2-one, alpinenone, valtrate isovaleroyloxyhydrine and nardostachin displayed stronger cytotoxicity against PANC-1 cell lines with IC50 values ranging from 0.01 ± 0.01 to 6.50 ± 1.10 µM. 1(10)-Aristolane-9ß-ol, 10-hydroxyguaia-1(5)-6,7-epoxy-2-one, nardoguaianone K, nardonoxide, epoxynardosinone, 1(10)-isonardosinone-8-ol-9-one-7,11-lactone, valtrate isovaleroyloxyhydrine and nardostachin showed remarkable cytotoxicity against SW1990 cell lines with IC50 values ranging from 0.07 ± 0.05 to 4.82 ± 6.96 µM. Furthermore, the primary mechanistic study of nardostachin demonstrated that it induced cell apoptosis via the mitochondria-dependent pathway, and induced SW1900 cell arrest at G2/M phase.

Single-Cell Characterization of Hepatic CD8+ T Cells in a Murine Model of Primary Biliary Cholangitis.

Primary biliary cholangitis (PBC), an organ-specific autoimmune disease, is characterized by injury to small bile ducts, inflammatory cell infiltrates within the liver, progressive cholestasis, and in some cases, cirrhosis with unclear pathogenesis. We aimed to clarify the importance role of hepatic immunce cells in the pathogenesis of human and experimental PBC.The dominant-negative TGFß receptor type II transgenic (dnTGFßRII) mice, a well-studied and established murine model of PBC were used to identify changes of immune cells, especially the pathogenic CD8+ T cells. The high-throughput single-cell RNA sequencing technology were applied and found functional heterogeneity among the hepatic CD8+ T cells subsets in dnTGFßRII mice. CD8+ T cells were confirmed the key cells leading to the pathogenesis of PBC in dnTGFßRII mice, and identified the terminally differentiated CD8αα T cells and CD8αß T cell subsets in the liver of dnTGFßRII mice. While terminally differentiated CD8αα T cells have higher cytokine production ability and cytotoxicity, the terminally differentiated CD8αß T cells retain their proliferative profile. Our work suggests that there are developmental and differentiated trajectories of pathogenic CD8+ T cell subsets in the pathogenesis of PBC. A further clarification of their roles would be helpful to our understanding of the pathogenesis of PBC and may potentially lead to identifying novel therapeutic modalities.

Screening prolyl hydroxylase domain 2 inhibitory activity of traditional Chinese medicine by CZE-UV.

Prolyl hydroxylase domain 2 (PHD2) is a key enzyme regulating the expression of hypoxia inducible factor (HIF). Its inhibitors can improve the expression of HIF and downstream genes, which can treat hypoxia-related diseases. Therefore, the establishment of a reliable PHD2 inhibitors screening method is of great significance for the drug development of hypoxia-related diseases. In this work, an accurate, rapid, and simple screening method for PHD2 inhibitors was introduced by capillary zone electrophoresis (CZE). In order to improve the detection sensitivity, the derivative reaction of α-ketoglutaric acid (α-OG) and 1,2-diaminobenzene (OPD) was used to enhance the UV absorption of α-OG (the substrate in the enzymatic reaction). The CZE method selected 20 mM Na2 B4 O7 buffer (pH 9.0) as the separation buffer, +25 kV as the separation voltage, 25°C as the cartridge temperature, and 210 nm as the detection wavelength. Under this condition, the analysis of a single sample can be realized within 9 min. Compared with the existing reported methods, the present work can directly screen the PHD2 inhibitory activity of traditional Chinese medicine (TCM) extracts, which is of significance for the target-purification of bioactive individual compounds from TCMs. Under the optimal conditions, the PHD2 inhibitor screening platform was successfully established, and it was found that 70% methanol/water extracts of Astragali Radix and Codonopsis pilosula had good PHD2 inhibitory activity. Furthermore, the present work provides a novel approach for screening the PHD2 inhibitory activity of TCM extracts and the discovery of anti-hypoxia bioactive compounds.

α-Glucosidase-Triggered Reaction for Fluorometric and Colorimetric Assays Based on the Formation of Silicon-Containing Nanoparticles.

Designing analytical approaches for enzymatic activity monitoring with high sensitivity and selectivity is of critical value for the diagnosis of diseases and biomedical studies. In this study, we have created a facile one-step synthetic route to prepare orange-red color and yellow fluorescent silicon-containing nanoparticles (Si CNPs) by mixing 3(2-aminoethylamino) propyl (dimethoxymethylsilane) and hydroquinone (HQ) in an aqueous solution. Inspired by the HQ-regulated facile synthetic step and the generation of HQ from α-glucosidase (α-Glu)-catalyzed hydrolysis of 4-hydroxyphenyl-α-d-glucopyranosyl (4-HPαDG), we have designed a straightforward colorimetric and fluorometric α-Glu activity assay using a commercially available 4-HPαDG as the α-Glu substrate. Fluorescent and colorimetric assays for α-Glu activity measurement have been thereby established and exhibited detection limits as low as 0.0032 and 0.0046 U/mL, respectively. Under single excitation at 370 nm, the prepared Si CNPs emitted yellow fluorescence at 520 nm and exhibited an absorbance peak at 390 nm. In addition, the proposed approach reveals various advantages including easy operation, time-saving, and good anti-interference ability. Hence, it could improve the progress of fluorometric and colorimetric enzymatic activity assays with high sensitivity and simplicity. Moreover, the proposed approach was applied for α-Glu inhibitor screening, and its feasibility in real samples was measured by detecting the α-Glu activity in human serum samples.

Characterization of Organ-Specific Regulatory B Cells Using Single-Cell RNA Sequencing.

Regulatory B cells (Breg) are considered as immunosuppressive cells. Different subsets of Breg cells have been identified both in human beings and in mice. However, there is a lack of unique markers to identify Breg cells, and the heterogeneity of Breg cells in different organs needs to be further illuminated. In this study, we performed high-throughput single-cell RNA sequencing (scRNA-seq) and single-cell B-cell receptor sequencing (scBCR-seq) of B cells from the murine spleen, liver, mesenteric lymph nodes, bone marrow, and peritoneal cavity to better define the phenotype of these cells. Breg cells were identified based on the expression of immunosuppressive genes and IL-10-producing B (B10) cell-related genes, to define B10 and non-B10 subsets in Breg cells based on the score of the B10 gene signatures. Moreover, we characterized 19 common genes significantly expressed in Breg cells, including Fcrl5, Zbtb20, Ccdc28b, Cd9, and Ptpn22, and further analyzed the transcription factor activity in defined Breg cells. Last, a BCR analysis was used to determine the clonally expanded clusters and the relationship of Breg cells across different organs. We demonstrated that Atf3 may potentially modulate the function of Breg cells as a transcription factor and that seven organ-specific subsets of Breg cells are found. Depending on gene expression and functional modules, non-B10 Breg cells exhibited activated the TGF-ß pathway, thus suggesting that non-B10 Breg cells have specific immunosuppressive properties different from conventional B10 cells. In conclusion, our work provides new insights into Breg cells and illustrates their transcriptional profiles and BCR repertoire in different organs under physiological conditions.

Narjatamolide, an Unusual Homoguaiane Sesquiterpene Lactone from Nardostachys jatamansi.

Narjatamolide (1), an unusual homoguaiane sesquiterpene lactone, was isolated from the roots and rhizomes of Nardostachys jatamansi DC. It represents the new carbon skeleton of a homoguaiane sesquiterpenoid possessing an additional acetate unit spiro-fused with C-4 and C-15 to form a cyclopropane ring. The structure of 1 was elucidated by extensive spectroscopic analyses, and the absolute configuration was confirmed by the electronic circular dichroism (ECD) calculations and X-ray single-crystal diffraction analysis. Compound 1 showed antiproliferative effects against BEL-7402 cell lines with an IC50 value of 5.67 ± 1.43 µM, and the mechanism study showed that 1 induces cell cycle of BEL-7402 cell lines arrest at G2/M phase.

[Construction of a stable 4.1R gene knockout cell model in RAW264.7 cells using CRISPR/Cas9 technique].

OBJECTIVE: To construct a cell model of 4.1R gene knockout in murine macrophage cell line RAW264.7 using CRISPR/Cas9 technique. METHODS: Three high?grade small?guide RNAs (sgRNAs) that could specifically identify 4.1R gene were synthesized and inserted into lentiCRISPRv2 plasmid. RAW264.7 cells were infected with sgRNA?Cas9 lentivirus from 293T cells transfected with the recombinant sgRNA?lentiCRISPRv2 plasmid, and the positive cells were screened using puromycin and the monoclonal cells were obtained. The expression of 4.1R protein in the monoclonal cells was measured by Western blotting, and the mutation site was confirmed by sequence analysis. Result A 4.1R gene knockout RAW264.7 cell line was obtained, which showed a 19?bp deletion mutation in the 4.1R gene sequence and obviously enhanced proliferation. CONCLUSION: We successfully constructed a 4.1R gene knockout macrophage cell line using CRISPR/Cas9 technique, which may facilitate further investigation of the function of 4.1R in macrophages.

[Survey on contact tracing of newly reported HIV infections in 2009 in Dehong prefecture, Yunnan province].

OBJECTIVE: To explore a new method for finding more HIV/AIDS. METHODS: In September 2009, newly reported HIV-infected individuals from May to August, 2009 in Dehong prefecture were asked to participate in a survey which requested demographic characteristics, history of high-risk behaviors and contact information of individuals with whom they had high risky contacts. People with risky contacts with HIV-infected cases (index cases) were also approached to participate in this survey and HIV testing was provided. RESULTS: A total of 342 HIV-infected individuals were newly reported and served as index cases from May to August, 2009. Among them, 47.1% (161/342) were transmitted by regular sexual partners. Through three-round surveys, 218 contacts were traced and among them, 84.9% (185/218) were traced by regular heterosexual partners. HIV positive rate of the tested was 34.7% (60/173) in the first-round tracing and 12.5% (1/8) in the second one. Among the 560 individuals (index cases and their high-risk contacts), the proportions of having regular heterosexual partners, non-regular and non-commercial sexual partners, commercial sexual heterosexual partners and men having sex men were 87.9% (492/560), 18.9% (106/560), 22.3% (125/560) and 0.3% (1/318), respectively, while the proportion of having never used condoms when having sex with the above four types sexual partners were 73.8% (363/492), 72.6% (77/106), 63.2% (79/125) and 0.0% (0/1), respectively. CONCLUSION: As an epidemiological method for HIV/AIDS finding, contact tracing identified a large number of HIV infectors who were traced by newly reported HIV-infected individuals.

[Tracing the sources of newly reported HIV infections in Dehong prefecture of Yunnan province].

OBJECTIVE: To trace and provide HIV-testing among those having contacts with HIV-infected individuals at various levels in Dehong prefecture, Yunnan province and to evaluate the effectiveness and feasibility of such investigation as a supplemental strategy for HIV testing and control. METHODS: Newly reported HIV infections from August throughout October in Dehong prefecture, in 2008 were asked to provide contact information of persons whom they had high risk contacts with. Persons having had risk contacts with HIV-infected cases were here of interviewed and their blood tested on the sero-status of HIV. RESULTS: A total of 335 HIV cases were newly reported during this three-month period. A total of 309 cases of them and 148 HIV infections identified thereafter from their risk contacts were under informed consent, to participate in this study. A total number of 3395 risk contacts were reported, of whom only 20.7% (704/3395) had 'contact information' and 51.3% (361/704) were successfully located and interviewed, including 117 previously confirmed HIV infections and 244 people with unknown HIV status. The majority of them (203 or 83.2% of 244) were then tested for HIV and 56 (27.6% of 203) were tested positive for HIV. The proportion of having detailed contact information and the proportion of being traced or followed among reported risk contacts of HIV infections were 68.8% and 68.2% for spouses of HIV patients, respectively, which were much higher than those among commercial sex partners (1.2% and 16.7%), casual sex partners (37.3% and 22.3%) and peers who sharing needles (34.1% and 56.4%). CONCLUSION: Newly reported HIV infections reported a large number of risk contacts and new HIV infections were identified among them. It was extremely difficult to trace commercial sex partners or casual sex partners on their HIV infection status. Nevertheless, tracing the risk contacts of newly reported HIV infections seemed to be helpful in identifying new HIV infections and in understanding the nature of transmission towards controlling the HIV epidemics.