Distinct Prevalence of Drug-Resistant Tuberculosis in Gansu, China: A Retrospective Study on Drug Susceptibility Profiles Between 2010 and 2014

Limited knowledge is available on regional distribution of antituberculosis (TB) drug resistance and on province-specific time-trends in TB drug susceptibility in China. To obtain the latest information about the dynamics of drug-resistant TB in Gansu province, we conducted a retrospective study and analyzed data on drug resistance among new TB cases diagnosed between June 2010 and May 2014 in Gansu, China. The data were collected from the only TB surveillance and treatment hospital in Gansu and, therefore, represented the epidemiology of TB in the province. The drug resistance was defined based on diagnostic drug susceptibility testing. Overall, 17.3% of TB new cases diagnosed during 2010 to 2014 in Gansu presented resistance to at least one anti-TB drug. And a total of 2.9% of new TB cases have multidrug resistance. The prevalence of multidrug-resistant TB in Gansu was found to resurge after 2013 (2.0%) after a steady decline between 2010 and 2012 (from 7.1% to 1.2%). The drug resistance patterns of TB and their revolution trends in Gansu differed from other regions of China. We report the first epidemiological description of drug-resistant TB in Gansu, which is distinct when compared to other regions. Our data demonstrate that the distribution of drug-resistant TB varies to a great extent among different geographic regions. And the results of our study greatly suggest that the implementation of individualized TB management and regimen policy based on the regional epidemiology of TB drug susceptibility is highly required.

[Mechanism of the Piezo1 protein-induced apoptosis of the chondrocytes through the MAPK/ERK1/2 signal pathway]

OBJECTIVE

To invstigate the mechanism of new mechanically-activated cation channel protein (Piezo1) can cause the apoptosis of the human chondrocytes under compressive loading, using a Flexercell unit by activating classical Mitogen-activated protein kinase (MAPK) signal pathyway(ERK1/2).

METHODS

Primary human chondrocytes were isolated, cultured, and then subjected to the static compressive loading for 0, 2, 12, 24, 48 h, respectively.The expressions of Piezo1 and the ERK1/2 were assessed by reverse transcription-polymerase chain reaction(PT-PCR), as well as the apoptosis gene B cell lymphoma/leukemia-2(Bcl-2) Bel-associated X protein(Bax). In addition, Piezo1inhibitor, Grammostola spatulata mechanotoxin 4(GsMTx4), was used to block Piezo1, served as a positive control.The immunofluorescence was used to locate the expression of Piezo1 protein and ERK1/2.AnnexinV-PI was used to detect the apoptosis of chondrocytes.

RESULTS

The expression of the Piezo1 in chondrocytesis was weak, the 12 h group was significant increased(0.198 1 vs 0.021 4, P<0.05), the 24 h group was the highest expression while the expression of the 48 h group was lower than the 24 h group, as well as the ERK1/2, Bcl-2 and caspase3.The result of AV-PI had shown that the 2 h group had increased early stage of apoptosis.The 12 h group had increased late stage of apoptosis, and the 24 h group's apoptotic rate was the highest, while the apoptotic rate of the 48 h group was lower than the 24 h group(0.497 1 vs 0.743 1, q=0.035 9). The GsMTx4 could inhibit the late stage of apoptosis, and the location of the Piezo1 was expressed in the nucleus and cytoplasm of the chondrocytes.

CONCLUSIONS

Piezo1 plays an important role in the apoptosis of the human chondrocyte through the classic MAPK/ERK1/2 signal pathway.

[Effect of allogenic mesenchymal stem cells transplantation on the expression of interleukin-22 and matrix metalloproteinase-3 in rats with collagen induced arthritis]

Objective: To study the effect of allogeneic bone marrow mesenchymal stem cells transplantation on the expression of interleukin -22 (IL-22), matrix metalloproteinase -3 (MMP-3) in serum and synovial of rats with collagen induced arthritis. Methods: Type Ⅱ collagen were injected twice to establish the collagen induced arthritis (CIA) rat model. Forty-eight rats were randomly divided into 3 groups: control group, CIA control group, CIA experiment group. Rat bone marrow mesenchymal stem cells were cultured by bone marrow method combined with adherent culture method. After identify, the remaining cells were injected in the CIA experimental group. Enzyme linked immunosorbent assay (ELISA) and immunohistochemistry were used to detect the expression of IL-22 and MMP-3 in serum and anklebone joint's synovium of rats, respectively. Synovial cells were isolated and cultured, and were treated with different concentrations of IL-22. MMP-3 protein and mRNA were detected before and after stimulation by Western blot and real-time quantitative polymerase chain reaction (RT-qPCR). Results: After MSC transplantation, arthritis index, X-ray, HE staining of CIA rat showed that joint damage significantly reduced compared with the control group. The ELISA results showed that the expression of MMP-3 and IL-22 in CIA control group was higher than those in the control group (125.79±9.12 vs 102.00±7.63 ng/ml, P<0.05), (292.35±31.23 vs 257.27±13.99 ng/ml, P<0.05) and CIA experiment group (125.79±9.12 vs 97.94±9.50 ng/ml, P<0.05), (292.35±31.23 vs 262.16±22.02 ng/ml, P<0.05) with statistically significant difference (P<0.05). There was no significant difference between the control group and CIA experimental group. Immunohistochemical showed similar results with ELISA. Western blotting and RT-qPCR showed that MMP-3 protein and mRNA expression was increased after IL-22 stimulation in a dose-dependent manner. Conclusion: IL-22 and MMP-3 play an important role in the pathogenesis of rheumatoid arthritis. IL-22 could regulate the expression of MMP-3, and bone marrow mesenchymal stem cells could reduce the expression of MMP-3 in the treatment of rheumatoid arthritis by reducing the expression of IL-22.

Targeted Enlargement of Aptamer Functionalized Gold Nanoparticles for Quantitative Protein Analysis

The ability to selectively amplify the detection signals for targets over interferences is crucial when analyzing proteins in a complicated sample matrix. Here, we describe a targeted enlargement strategy that can amplify the light-scattering signal from aptamer-functionalized gold nanoparticles (Apt-AuNP) with high specificity for quantitative protein analysis. This strategy is achieved by labeling target proteins with competitively protected Apt-AuNP probes and enlarging the probes with gold enhancement. This competitive protection strategy could effectively eliminate nonspecific protein adsorptions from a sample matrix, leading to a highly specific labeling of the target protein. As a result, the subsequent amplification of the light-scattering signal by gold enhancement only occurs in the presence of the target protein. This strategy was successfully demonstrated by analyzing human α-thrombin in human serum samples in a Western blot format.

Polymorphism analysis of multi-parent advanced generation inter-cross (MAGIC) populations of upland cotton developed in China

Upland cotton (Gossypium hirsutum L.) is an important cash crop that provides renewable natural fiber worldwide. Currently limited genetic base leads to a decrease in upland cotton genetic diversity. Multi-parent advance generation inter-cross (MAGIC) populations can be used to evaluate complex agronomic traits in crops. In this study, we developed an upland cotton MAGIC population. A total of 258 MAGIC population lines and their twelve founder lines were analyzed, using 432 pairs of simple sequence repeat (SSR) markers. Gene diversity indices and the polymorphism information content were calculated using polymorphism analyses. Our genotype analysis showed that 258 inbred lines could be divided into 158 genotypes. Among these, we identified 17 pairs of specific SSR primers on the A chromosome subgroups and 24 pairs of specific SSR primers on the B chromosome subgroups of upland cotton. These were related to 77 and 128 genotypes, respectively. Our results suggest that the upland cotton MAGIC population contained abundant genetic diversity and may provide enormous resources for future genetic breeding.

Exploiting the interaction between a semiconductor nanosphere and a thin metal film for nanoscale plasmonic devices

The interaction of silicon (Si) nanospheres (NSs) with a thin metal film is investigated numerically and experimentally by characterizing their forward scattering properties. A sharp resonant mode and a zero-scattering dip are found to be introduced in the forward scattering spectrum of a Si NS by putting it on a 50-nm-thick gold film. It is revealed that the sharp resonant mode arises from a new magnetic dipole induced by the electric dipole and its mirror image while the zero-scattering dip originates from the destructive interference between the new magnetic dipole and the original one together with its mirror image. A significant enhancement in both electric and magnetic fields is achieved at the contact point between the Si NS and the metal film. More interestingly, the use of a thin silver film can lead to vivid scattering light with different color indices. It is demonstrated that a small change in the surrounding environment of Si NSs results in the broadening of the resonant mode and the disappearance of the zero-scattering dip. Our findings indicate that dielectric-metal hybrid systems composed of semiconductor NSs and thin metal films act as attractive platforms on which novel nanoscale plasmonic devices can be realized.

Comparative cytotoxicity of fourteen trivalent and pentavalent arsenic species determined using real-time cell sensing

The occurrence of a large number of diverse arsenic species in the environment and in biological systems makes it important to compare their relative toxicity. The toxicity of arsenic species has been examined in various cell lines using different assays, making comparison difficult. We report real-time cell sensing of two human cell lines to examine the cytotoxicity of fourteen arsenic species: arsenite (As^III), monomethylarsonous acid (MMA^III) originating from the oxide and iodide forms, dimethylarsinous acid (DMA^III), dimethylarsinic glutathione (DMAG^III), phenylarsine oxide (PAO^III), arsenate (As^V), monomethylarsonic acid (MMA^V), dimethylarsinic acid (DMA^V), monomethyltrithioarsonate (MMTTA^V), dimethylmonothioarsinate (DMMTA^V), dimethyldithioarsinate (DMDTA^V), 3-nitro-4-hydroxyphenylarsonic acid (Roxarsone, Rox), and 4-aminobenzenearsenic acid (p-arsanilic acid, p-ASA). Cellular responses were measured in real time for 72hr in human lung (A549) and bladder (T24) cells. IC₅₀ values for the arsenicals were determined continuously over the exposure time, giving rise to IC₅₀ histograms and unique cell response profiles. Arsenic accumulation and speciation were analyzed using inductively coupled plasma-mass spectrometry (ICP-MS). On the basis of the 24-hr IC₅₀ values, the relative cytotoxicity of the tested arsenicals was in the following decreasing order: PAO^III≫MMA^III≥DMA^III≥DMAG^III≈DMMTA^V≥As^III≫MMTTA^V>As^V>DMDTA^V>DMA^V>MMA^V≥Rox≥p-ASA. Stepwise shapes of cell response profiles for DMA^III, DMAG^III, and DMMTA^V coincided with the conversion of these arsenicals to the less toxic pentavalent DMA^V. Dynamic monitoring of real-time cellular responses to fourteen arsenicals provided useful information for comparison of their relative cytotoxicity.

p-Azidophenylarsenoxide: An Arsenical "Bait" for the In Situ Capture and Identification of Cellular Arsenic-Binding Proteins

Identification of arsenic-binding proteins is important for understanding arsenic health effects and for developing arsenic-based therapeutics. We report here a strategy for the capture and identification of arsenic-binding proteins in living cells. We designed an azide-labeled arsenical, p-azidophenylarsenoxide (PAzPAO), to serve bio-orthogonal functions: the trivalent arsenical group binds to cellular proteins in situ, and the azide group facilitates click chemistry with dibenzylcyclooctyne. The selective and efficient capture of arsenic-binding proteins enables subsequent enrichment and identification by shotgun proteomics. Applications of the technique are demonstrated using the A549 human lung carcinoma cells and two in vitro model systems. The technique enables the capture and identification of 48 arsenic-binding proteins in A549 cells incubated with PAzPAO. Among the identified proteins are a series of antioxidant proteins (e.g., thioredoxin, peroxiredoxin, peroxide reductase, glutathione reductase, and protein disulfide isomerase) and glyceraldehyde-3-phosphate dehydrogenase. Identification of these functional proteins, along with studies of arsenic binding and enzymatic inhibition, points to these proteins as potential molecular targets that play important roles in arsenic-induced health effects and in cancer treatment.

Kinetics of Proximity-Induced Intramolecular DNA Strand Displacement

Proximity-induced intramolecular DNA strand displacement (PiDSD) is one of the key mechanisms involved in many DNA-mediated proximity assays and protein-responsive DNA devices. However, the kinetic profile of PiDSD has never been systematically examined before. Herein, we report a systematic study to explore the kinetics of PiDSD by combining the uses of three DNA strand displacement techniques, including a binding-induced DNA strand displacement to generate PiDSD, an intermolecular DNA strand-exchange strategy to measure a set of key kinetic parameters for PiDSD, and a toehold-mediated DNA strand displacement to generate fluorescence signals for the real-time monitoring of PiDSD. By using this approach, we have successfully revealed the kinetic profiles of PiDSD, determined the enhanced local effective concentrations of DNA probes that are involved in PiDSD, and identified a number of key factors that influence the kinetics of PiDSD. Our study on PiDSD establishes knowledge and strategies that can be used to guide the design and operation of various DNA-mediated proximity assays and protein-triggered DNA devices.

Arsenic Species in Chicken Breast: Temporal Variations of Metabolites, Elimination Kinetics, and Residual Concentrations

BACKGROUND

Chicken meat has the highest per capita consumption among all meat types in North America. The practice of feeding 3-nitro-4-hydroxyphenylarsonic acid (Roxarsone, Rox) to chickens lasted for more than 60 years. However, the fate of Rox and arsenic metabolites remaining in chicken are poorly understood.

OBJECTIVES

We aimed to determine the elimination of Rox and metabolites from chickens and quantify the remaining arsenic species in chicken meat, providing necessary information for meaningful exposure assessment.

METHODS

We have conducted a 35-day feeding experiment involving 1,600 chickens, of which half were control and the other half were fed a Rox-supplemented diet for the first 28 days and then a Rox-free diet for the final 7 days. We quantified the concentrations of individual arsenic species in the breast meat of 229 chickens.

RESULTS

Rox, arsenobetaine, arsenite, monomethylarsonic acid, dimethylarsinic acid, and a new arsenic metabolite, were detected in breast meat from chickens fed Rox. The concentrations of arsenic species, except arsenobetaine, were significantly higher in the Rox-fed than in the control chickens. The half-lives of elimination of these arsenic species were 0.4-1 day. Seven days after termination of Rox feeding, the concentrations of arsenite (3.1 μg/kg), Rox (0.4 μg/kg), and a new arsenic metabolite (0.8 μg/kg) were significantly higher in the Rox-fed chickens than in the control.

CONCLUSION

Feeding of Rox to chickens increased the concentrations of five arsenic species in breast meat. Although most arsenic species were excreted rapidly when the feeding of Rox stopped, arsenic species remaining in the Rox-fed chickens were higher than the background levels.

CITATION

Liu Q, Peng H, Lu X, Zuidhof MJ, Li XF, Le XC. 2016. Arsenic species in chicken breast: temporal variations of metabolites, elimination kinetics, and residual concentrations. Environ Health Perspect 124:1174-1181; http://dx.doi.org/10.1289/ehp.1510530.

[SPINK3: A novel growth factor that promotes rat liver regeneration]

Serine peptidase inhibitor, Kazal type 3 (SPINK3) is a trypsin inhibitor, and also a growth factor that has an identical structure to epidermal growth factor (EGF), which could combine with epidermal growth factor receptor (EGFR) to promote cell proliferation. To shed light on the role and regulation mechanism of SPINK3 in rat liver regeneration (LR), Rat Genome 230 2.0 assay was used to detect the expression profiles of LR genes after partial hepatectomy (PH). The results showed that Spink3 was significantly up-regulated at 2-24 h and 72-168 h after PH. In the present study, RT-PCR and immunoblotting were used to validate the assay results. Ingenuity Pathway Analysis 9.0 (IPA) software was used to build the SPINK3 signaling regulating LR and analyze the possible mechanism. And then the expression of cell proliferation-associated gene Ccna2 was examined by RT-PCR in normal rat liver cell line BRL-3A in which Spink3 was overexpressed. The results showed that Ccna2 was significantly up-regulated in BRL-3A in which Spink3 was over-expressed. SPINK3 combining with EGFR accelerated cell proliferation during rat liver regeneration via P38, PKC, JAK-STAT and AKT pathways. Thus, SPINK3 was likely to promote hepatocytes proliferation in LR through P38, PKC, JAK-STAT and AKT.

Emerging Disinfection Byproducts, Halobenzoquinones: Effects of Isomeric Structure and Halogen Substitution on Cytotoxicity, Formation of Reactive Oxygen Species, and Genotoxicity

Halobenzoquinones (HBQs) are a structurally diverse class of water disinfection byproducts. Here, we report a systematic study on the effects of isomeric structure and the type and number of halogen substitutions of HBQs on their cytotoxicity, formation of reactive oxygen species (ROS), and genotoxicity. Dynamic responses and IC50 histograms were obtained using real-time cell analysis, clearly ranking the cytotoxicity of the HBQs in Chinese hamster ovary (CHO-K1) cells. Strong isomeric structure effects were shown with 2,5-HBQ isomers inducing greater cytotoxicity than their corresponding 2,6-HBQ isomers (P < 0.05). HBQ-halogen substitution groups also influence cytotoxicity, as cytotoxicity increases across the dihalogenated HBQs: iodo- > bromo- > chloro-HBQs (P < 0.05). Determination of HBQ-induced ROS further supports isomeric structure and halogen substitution effects. HBQ-induced genotoxicity was shown as increased levels of 8-hydroxy-2'-deoxyguanosine and p53 protein. Pearson correlation analysis of the HBQ toxicity measurements with their physicochemical parameters demonstrates that dipole moment and the lowest unoccupied molecular orbital energy are two major structural influences on toxicity (r = -0.721 or -0.766, P < 0.05). Dipole moment also correlates with isomer toxicity. This study suggests that formation and occurrence of highly toxic iodo-HBQs and 2,5-HBQs warrant further investigation to fully assess the impact of HBQs in drinking water.

Comparison of two methods for RNA extraction from the nucleus pulposus of intervertebral discs

RNA extraction from the nucleus pulposus of intervertebral discs has been extensively used in orthopedic studies. We compared two methods for extracting RNA from the nucleus pulposus: liquid nitrogen grinding and enzyme digestion. The RNA was detected by agarose gel electrophoresis, and the purity was evaluated by absorbance ratio using a spectrophotometer. Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) expression was assayed by reverse transcription-polymerase chain reaction (RT-PCR). Thirty human lumbar intervertebral discs were used in this study. The liquid nitrogen-grinding method was used for RNA extraction from 15 samples, and the mean RNA concentration was 491.04 ± 44.16 ng/mL. The enzyme digestion method was used on 15 samples, and the mean RNA concentration was 898.42 ± 38.64 ng/mL. The statistical analysis revealed that there was a significant difference in concentration between the different methods. Apparent 28S, 18S, and 5S bands were detectable in RNA extracted using the enzyme digestion method, whereas no 28S or 18S bands were detected in RNA extracted using the liquid nitrogen-grinding method. The GAPDH band was visible, and no non-specific band was detected in the RT-PCR assay by the enzyme digestion method. Therefore, the enzyme digestion method is an efficient and easy method for RNA extraction from the nucleus pulposus of intervertebral discs for further intervertebral disc degeneration-related studies.

Association of NT-proBNP and interleukin-17 levels with heart failure in elderly patients

Pro-B-type natriuretic peptide (NT-proBNP) and interleukin-17 (IL-17) are involved in the pathophysiological processes of heart failure; however, the exact role of IL-17 is not clear. We explored the relationship between IL-17 and NT-proBNP, as a clinical parameter, in heart failure. The whole blood IL-17 and NT-proBNP levels and the readmission rates in 70 patients with chronic heart failure class III or IV according to the New York Heart Association and 35 patients with normal heart function (control group) were measured and compared. The left ventricle ejection fractions (LVEFs) and NT-proBNP and IL-17 levels in cardiac functional class III (40.38 ± 4.76%, 7780 ± 6393 pg/mL, 8.65 ± 3.05 pg/mL, respectively) and class IV (31.59 ± 4.31%, 13,704 ± 10,945, 21.10 ± 10.60 pg/mL, respectively) were higher than those in the control group (61.27 ± 5.66%, 420 ± 256 pg/mL, 3.53 ± 2.05 pg/mL, respectively). Compared to the cardiac functional class IV, class III showed significantly higher values for LVEF and NT-proBNP and IL-17 levels (P < 0.05). The readmission rates of the patients in cardiac functional class III at 3 and 6 months (15.7 and 34.4%, respectively) and cardiac functional class IV at 3 and 6 months (39.5 and 76.3%, respectively) were significantly higher than those in the control group (0 and 5.7%, respectively) (P < 0.05). The NT-proBNP and IL-17 levels increased as the heart function worsened. NT-proBNP and IL-17 may play essential roles in the process of heart failure.

Posterodorsal Medial Amygdala Mediates Tail-Pinch Induced Food Intake in Female Rats

Comfort eating during periods of stress is a common phenomenon observed in both animals and humans. However, the underlying mechanisms of stress-induced food intake remain elusive. The amygdala plays a central role in higher-order emotional processing and the posterodorsal subnucleus of the medial amygdala (MePD), in particular, is involved in food intake. Extra-hypothalamic corticotrophin-releasing factor (CRF) is well recognised for mediating behavioural responses to stress. To explore the possible role of amygdala CRF receptor activation in stress-induced food intake, we evaluated whether a stressor such as tail-pinch, which reliably induces food intake, would fail to do so in animals bearing bilateral neurotoxic lesions of the MePD. Our results showed that ibotenic acid induced lesions of the MePD markedly reduced tail-pinch induced food intake in ovariectomised, 17β-oestradiol replaced rats. In addition, intra-MePD (right side only) administration of CRF (0.002 or 0.02 ng) via chronically implanted cannulae resulted in a dose-dependent increase in food intake, although higher doses of 0.2 and 2 ng CRF had less effect, producing a bell shaped curve. Furthermore, intra-MePD (bilateral) administration of the CRF receptor antagonist, astressin (0.3 μg per side) effectively blocked tail-pinch induced food intake. These data suggest that the MePD is involved in stress-induced food intake and that the amygdala CRF system may be a mediator of comfort eating.

Nontargeted identification of peptides and disinfection byproducts in water

A broad range of organic compounds are known to exist in drinking water sources and serve as precursors of disinfection byproducts (DBPs). Epidemiological findings of an association of increased risk of bladder cancer with the consumption of chlorinated water has resulted in health concerns about DBPs. Peptides are thought to be an important category of DBP precursors in water. However, little is known about the actual presence of peptides and their DBPs in drinking water because of their high sample complexity and low concentrations. To address this challenge and identify peptides and non-chlorinated/chlorinated peptide DBPs from large sets of organic compounds in water, we developed a novel high throughput analysis strategy, which integrated multiple solid phase extraction (SPE), high performance liquid chromatography (HPLC) separation, and non-target identification using precursor ion exclusion (PIE) high resolution mass spectrometry (MS). After MS analysis, structures of candidate compounds, particularly peptides, were obtained by searching against the Human Metabolome Database (HMDB). Using this strategy, we successfully detected 625 peptides (out of 17,205 putative compounds) and 617 peptides (out of 13,297) respectively in source and finished water samples. The source and finished water samples had 501 peptides and amino acids in common. The remaining 116 peptides and amino acids were unique to the finished water. From a subset of 30 putative compounds for which standards were available, 25 were confirmed using HPLC-MS analysis. By analyzing the peptides identified in source and finished water, we successfully confirmed three disinfection reaction pathways that convert peptides into toxic DBPs.

Association of the programmed cell death-1 PD1.5 C>T polymorphism with cervical cancer risk in a Chinese population

The association of the programmed cell death-1 PD1.5 C>T polymorphism with cervical cancer risk has not been investigated. In this hospital-based case-control study, we analyzed 256 patients with cervical cancer and 250 healthy controls. Pearson chi-square test was used to examine differences in the distribution of genotypes between cases and controls. Association between the polymorphism and the susceptibility to cervical cancer was evaluated using unconditional logistic regression analysis. This revealed that the frequencies of the three genotypes (CC, CT, and TT) in cervical cancer cases and controls were 17.58, 65.23, and 17.19% and 24.80, 40.40, and 34.80%, respectively; the difference between the two groups was significant (P < 0.001). We found that the CT genotype was significantly associated with increased cervical cancer risk (adjusted OR = 2.18; 95%CI = 1.37-6.11; P = 0.009). Moreover, there was significant association between PD-1.5 C/T polymorphism and susceptibility to cervical cancer under dominant model (OR = 1.27, 95%CI = 1.01-2.15, P = 0.047). We conclude that the PD-1.5 C/T polymorphism may be associated with increased risk of cervical cancer. The study also highlights the importance of conducting genetic association studies in different ethnic populations.

[Characteristics of social supportive network serving the older female sex workers in Qingdao]

OBJECTIVE

To overview the status of social support on older female sex workers (OFSWs) in Qingdao and to better understand the characteristics of this egocentric social support networks.

METHODS

Ucinet 6 software was used to analyze the characteristics of egocentric social networks which involving 400 OFSWs who were recruited by respondent-driven sampling (RDS) method in Qingdao during March 2014 to June. Structural equation model (SEM) was used for data analysis, fitted test and estimation.

RESULTS

A total of 400 OFSWs of Qingdao nominated 1 617 social supportive members, and the average size of egocentric social networks of OFSWs was (4.0 ± 1.5). Among all the alter egos (social support network members of the egos), 613 were female sex workers fellows, accounted for the most important part of all the social ties (37.91%). Characteristics of small size and non-relative relationships were seen more obviously among OFSWs with non-local registration and the ratings of emotional support (4.42±2.38) was significantly lower than the tangible support (5.73 ± 1.69) (P<0.05). Result of the SEM showed that homogeneity, joint strength and the network structure were significantly related to the ratings of average support. The total standard effects of which were 0.110, 0.925 and -0.069 respectively. It seemed that homogeneity can affect the degree of support, both directly and indirectly.

CONCLUSION

OFSWs in Qingdao tended to ask for social support from friends who were also female sex workers. Stronger the joint strength between egos and alters, greater the homogeneity between the two was seen. Tighter relations among the alter egos, higher degree of average social support of the egos were acquired.