[Determination of mifepristone in workplace air by ultra-performance liquid chromatography]

Objective: To establish an ultra-high performance liquid chromatography method for the determination of mifepristone in the air of workplaces. Methods: From January to July 2018, glass fiber filter membrane was used to collect mifepristone in the workplace air, eluted with acetonitrile/water solution, and determined by ultra-high performance liquid chromatography-UV method. Results: The detection limit of mifepristone determination method was 0.005 μg/ml, the lower limit of quantification was 0.015 μg/ml, and the lowest detection concentration was 0.14 μg/m(3) (calculated by collecting 75 L air samples) . The concentration of mifepristone has a good linear relationship between 0.015-40.24 μg/ml, r=0.9999. The accuracy and elution efficiency of the method were calculated based on the recovery rate, ranging from 92.7% to 100.0%. The average sampling efficiency was 99.6%-100.0%. The intra-assay precision of the method was 0.92% to 5.41%, and the inter-assay precision was 0.89% to 6.25%. The sample could be stored stably for 3 days at 4°C. Conclusion: The ultra-high performance liquid chromatography method for determination of mifepristone is easy to operate, and its indicators meet the requirements of GBZ/T 201.4-2008 "Guidelines for the Establishment of Occupational Hygiene Standards Part 4: Methods for Determination of Chemical Substances in Workplace Air", which is suitable for the detection of mifepristone in the air of the workplace.

Upregulation of Chemokines in the Paraventricular Nucleus of the Hypothalamus in Rats with Stress-Induced Hypertension

Background

The neuroinflammation of paraventricular nucleus (PVN) of the hypothalamus has been implicated in the development of hypertension. The promoted invasion of peripheral immune cells into PVN may be attributed to the upregulation of chemokines, then exacerbating neuroinflammation. We studied the expressions of chemokines, activation of microglial cells, and inflammatory mediators in PVN of rats with stress-induced hypertension (SIH).

Material/Methods

SIH was induced by electrical foot shock combined with noise for 2 h twice a day, at an interval of 4 h for 14 consecutive days. At the end of the 14th day, fresh PVN tissues were collected to measure the expressions of chemokines using the RayBiotech antibody array.

Results

We are the first to report that the expression of CXCL7 was extremely high in PVN of control rats, and was significantly lower in SIH rats. The expressions of CCL2 and CX3CL1 in PVN of SIH rats significantly exceeded those of control rats. The numbers of CX3CR1 (receptor of CX3CL1)-immunostained cells and oxycocin-42 (OX-42, marker of microglia)-positive cells increased in PVN of the SIH rats. The stress enhanced the protein expressions of proinflammatory cytokines IL-6 and IL-17 and reduced those of anti-inflammatory cytokines TGF-β and IL-10 in PVN.

Conclusions

In PVN of SIH rats, chronic stress induced neuroinflammation characterized by the activated microglia and upregulated proinflammatory cytokines. Expressions of chemokines CXCL7, CX3CL1, and CCL2 were altered. The causal link of chemokines to PVN neuroinflammation and hypertension remain to be determined.

Risk of SARS-CoV-2 infection among contacts of individuals with COVID-19 in Hangzhou, China

OBJECTIVES

This study determined the rate of secondary infection among contacts of individuals with confirmed coronavirus disease 2019 (COVID-19) in Hangzhou according to the type of contacts, the intensity of contacts, and their relationship with the index patient.

STUDY DESIGN

This is a retrospective cohort study.

METHODS

The analysis used the data of 2994 contacts of 144 individuals with confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The contacts were categorized according to the information source, type of contact, location, intensity of contact, and relationship with the index patient.

RESULTS

The incidence of infection differed significantly according to contact type. Of the contacts, 186 (6.2%) developed symptoms, and 71 (2.4%) had confirmed SARS-CoV-2 infection. The main symptoms were cough and fever. Compared with those who had brief contact with the index case, those who had dined with the index case had 2.6 times higher risk of acquiring infection; those who had shared transport with, had visited, or had contact with the index case in a medical institution had 3.6 times higher risk of acquiring infection; and household contacts had 41.7 times higher risk of acquiring infection. Family members had 31.6 times higher risk of acquiring infection than healthcare providers or other patients exposed to an index case.

CONCLUSIONS

The form and frequency of contact are the main factors affecting the risk of infection among contacts of individuals with COVID-19. Centralized isolation and observation of close contacts of individuals with confirmed SARS-CoV-2 infection, in addition to population-based control measures, can reduce the risk of secondary infections and curb the spread of the infection.

Reduced miR-363-3p expression in non-small cell lung cancer is associated with gemcitabine resistance via targeting of CUL4A

OBJECTIVE

Accumulating evidence has suggested that aberrant expression of microRNAs (miRNAs) is associated with non-small cell lung cancer (NSCLC) proliferation, migration, invasion and chemotherapy resistance. Cullin4A (CUL4A) has been previously reported to desensitize NSCLC cells to chemotherapy treatment. However, whether miRNAs regulate CUL4A to promote chemotherapy resistance remains unknown.

PATIENTS AND METHODS

Tissues were obtained from 40 NSCLC patients who received surgery at the Yancheng City No. 1 People's Hospital. Cell Counting Kit-8 (CCK-8) assays were applied for the detection of cell proliferation; mRNA and protein levels were determined by Real Time-quantitative Polymerase Chain Reaction (RT-qPCR) and Western blot, respectively. The interaction between mRNA 3'UTR and miRNA was predicted by TargetScan and verified by Dual-Luciferase reporter assay.

RESULTS

In the present study, miR-363-3p levels were revealed to be significantly decreased in tumor tissues obtained from NSCLC patients compared with adjacent normal tissues. The results of the CCK-8 assays showed that the overexpression of miR-363-3p may slightly inhibit the proliferation of A549 and H23 cells. Notably, the transfection with miR-363-3p antagonists reduced the sensitivity of A549 and H23 cells to gemcitabine treatment, whereas the overexpression of miR-363-3p markedly increased the sensitivity of A549 and H23 cells to gemcitabine treatment. Furthermore, CUL4A mRNA and protein levels were revealed to be decreased in A549 cells transfected with miR-363-3p mimics. The Dual-Luciferase reporter assay results further suggested that CUL4A represents a target gene of miR-363-3p.

CONCLUSIONS

The results indicated that decreased miR-363-3p expression enhanced gemcitabine resistance in NSCLC cells via regulation of CUL4A.

Abstract PR05: A genetic variant at 6q25 associated with estrogen receptor-negative breast cancer subtypes in Peruvian breast cancer patients

Background: We have previously identified a genetic variant, rs140068132, which has a strong protective effect on breast cancer risk. This variant is located near the estrogen receptor 1 gene (ESR1) on chromosome 6q25, a locus which has been repeatedly implicated in breast cancer risk. Women who carry two copies of the protective variant (GG) have 60-70% reduction in risk of developing breast cancer compared to women with none. The G variant has relatively high frequency in Latin American women (up to 23% in the 1000 Genomes Project Peruvians); it is only common in people of Indigenous American ancestry and almost absent in all other populations. We investigated whether the rs140068132-A/G polymorphism is associated with a specific breast cancer subtype among Peruvian women with breast cancer.

Methods: Blood samples and clinical data were collected from 441 women with breast cancer at the Instituto Nacional de Enfermedades Neoplasicas in Lima, Peru. Genotypic profiles were generated using the Affymetrix Precision Medicine Research Array. Four major breast cancer subtypes were identified based on immunohistochemical markers (luminal A, luminal B, triple-negative, and human epidermal growth factor receptor 2 (HER2) overexpressing). Quality control of the genotyped data was performed in PLINK. Genetic ancestry was determined for each individual using ADMIXTURE. ANOVAs were performed on the proportion of genetic ancestry and disease subtype. PLINK was used to perform a binary logistic regression on the rs140068132 variant and ER status (ER-negative versus-ER positive), with age and genetic ancestry as covariates.

Results: The breast cancer patients analyzed have the following average ancestry proportions: 77.3% Indigenous American, 17.4% European, 3.8% African and 1.5% East Asian. The frequency of the G allele in the Peruvian breast cancer patients is 14% (compared to 23% in healthy individuals from the 1000 Genomes Project). We found that the G allele of rs140068132 was associated with ER-negative status among cases (OR = 0.6443, P = 0.086) for both HER2 overexpressing and triple-negative. We also examined the proportions of ancestry in relation to subtypes of disease. The proportion of Indigenous American ancestry was associated with the HER2 overexpressing subtype (P = 0.06), with an average Indigenous American ancestry among these patients of 83.1% compared to 77.3% among all patients. The proportion of African ancestry was higher in women with the triple-negative subtype, with an average African ancestry of 4.8% among patients with the triple-negative subtype compared to a 3.8% average among all patients, but this trend was not statistically significant (P = 0.21).

Conclusions: The lower frequency of the variant in Peruvian breast cancer cases is consistent with a protective effect in this population. We have confirmed that the protective effect of the rs140068132 variant is stronger for ER-negative subtypes. Additional analyses are under way in a larger sample of Peruvian breast cancer patients.

This abstract is also being presented as Poster C051.

Citation Format: K.M. Marker, T. Vidaurre, L.I. Tamayo, J.N. Vásquez, R. Meza Florez, S. Casavilca, M. Calderon, J.E. Abugattas, H.L. Gómez, H.A. Fuentes, C.L. Monge Pimentel, S. Song, D. Cherry, S. Huntsman, D. Hu, E. Ziv, L. Fejerman. A genetic variant at 6q25 associated with estrogen receptor-negative breast cancer subtypes in Peruvian breast cancer patients [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr PR05.

[Determination of tungsten and insoluble compounds in the air of workplace by ICP-OES]

Objective: To establish the method for determination of tungsten and insoluble compounds in the air of workplace by inductively coupled plasma optical emission spectrometry (ICP-OES) . Methods: The tungsten and insoluble compounds were digested by microwave digestion apparatus using nitric acid and hydrofluoric acid, detected by ICP-OES. Results: The linearity of tungsten and insoluble compounds (as tungsten) were good at the range of 0.16-100.0 μg/ml, the minimum quantitation concentration was 0.11 mg/m(3), the recovery was ranged from 81.9%-97.1%, the RSD of intra-and inter-batch precision were 0.5%-2.5% and 1.2%-4.4%, respectively. Conclusion: The determination method meet the requirement of analysis and apply to the determination of tungsten and insoluble compounds in the air of workplace.

Direct investigation of current transport in cells by conductive atomic force microscopy

Currents play critical roles in neurons. Direct observation of current flows in cells at nanometre dimensions and picoampere current resolution is still a daunting task. In this study, we investigated the current flows in hippocampal neurons, PC12 cells and astrocytes in response to voltages applied to the cell membranes using conductive atomic force microscopy (CAFM). The spines in the hippocampal neurons play crucial roles in nerve signal transfer. When the applied voltage was greater than 7.2 V, PC12 cells even show metallic nanowire-like characteristics. Both the cell body and glial filaments of astrocytes yielded CAFM test results that reflect different electrical conductance. To our best knowledge, the electrical characteristics and current transport through components of cells (especially neurons) in response to an applied external voltage have been revealed for the first time at nanometre dimensions and picoampere current levels. We believe that such studies will pave new ways to study and model the electrical characteristics and physiological behaviours in cells and other biological samples.

Retinoprotective Effects of TAT-Bound Vasoactive Intestinal Peptide and Pituitary Adenylate Cyclase Activating Polypeptide

Vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase activating polypeptide (PACAP) belong to the same peptide family and exert a variety of biological functions. Both PACAP and VIP have protective effects in several tissues. While PACAP is known to be a stronger retinoprotective peptide, VIP has very potent anti-inflammatory effects. The need for a non-invasive therapeutic approach has emerged and PACAP has been shown to be retinoprotective when administered in the form of eye drops as well. The cell penetrating peptide TAT is composed of 11 amino acids and tagging of TAT at the C-terminus of neuropeptides PACAP/VIP can enhance the traversing ability of the peptides through the biological barriers. We hypothesized that TAT-bound PACAP and VIP could be more effective in exerting retinoprotective effects when given in eye drops, by increasing the traversing efficacy and enhancing the activation of the PAC1 receptor. Rats were subjected to bilateral carotid artery occlusion (BCCAO), and retinas were processed for histological analysis 14 days later. The efficiency of the TAT-bound peptides to reach the retina was assessed as well as their cAMP increasing ability. Our present study provides evidence, for the first time, that topically administered PACAP and VIP derivatives (PACAP-TAT and VIP-TAT) attenuate ischemic retinal degeneration via the PAC1 receptor presumably due to a multifactorial protective mechanism.

Abstract 4184: Tumor and risk factor characteristics among breast cancer patients from different geographic regions in Peru

There are few Latin American cohorts with available biospecimens that include women of high Indigenous American ancestry. The Peruvian population is characterized by a high degree of Native American (NA) ancestry, with this ancestral component varying between 56 to 100% on average, depending on the region. We have collected 1199 Peruvian samples from the Instituto Nacional de Enfermedades Neoplasicas in Lima. This cohort of patients represents a unique opportunity to study the molecular characteristics of breast cancer in the NA genetic and genomic background. Here we present a basic description of the women in the study and a comparison of tumor subtypes distribution and risk factor information of the patients by place of birth and residence.

We explored differences in tumor subtype distribution and risk factors in relation to place of birth or residence in the three main geographical region of Peru. To test differences in proportions we used Chi2 or Fisher-exact tests. To test differences in means for continuous variables we used ANOVA or t-tests. Genetic ancestry was estimated using genome wide genotypes and the program ADMIXTURE. Tumor subtypes were defined using the following criteria: ER+/PR+/HER2- as luminal A, ER+/PR+/HER2+ as luminal B, ER-/PR-/HER2+ as HER2+ and ER-/PR-/HER2- as triple negative.

Overall, the patients included in the study were relatively young (50 yrs, SD=11.0). The average number of full-term pregnancies was 3 (SD=1.8), the average age at first pregnancy 22 (SD=5.7) and age at menarche was 13 (SD=1.8). The tumor subtype distribution was 31% of Luminal B tumors, 24% luminal A, 12% HER2 and 12% triple negative and did not differ by place of birth or residence. We found that patients from the Coastal region were heavier and taller than those born in the Andean region (p<0.005). Women born in the Coastal region had the lowest age at menarche and a lower number of full-term pregnancies (p<0.0001). Similar trends were observed when we compared women by place of residence. Patients born in Lima, the Capital of Peru, smoke more (p<0.05), were heavier, had lower age at menarche, lower number of full term pregnancies and were diagnosed at a younger age, compared to women born outside the city (p<0.05). The distribution of NA genetic ancestry also varied by place of birth: patients born outside Lima had higher proportion of NA ancestry (78% SD=0.15 vs. 74%, SD=0.18, p<0.05).

The distribution of tumor subtypes among women in the Peruvian breast cancer cohort did not differ by place of birth or residence. However, we found that for some breast cancer risk factors, exposures differed between women from different regions. Finally, given the relatively low observed values for reproductive and lifestyle related exposures and the high proportion of Indigenous American ancestry of Peruvian women, this cohort is likely to be particularly informative to study genetic predisposition to breast cancer.

Citation Format: Valentina Zavala, Tatiana Vidaurre, Katie Marker, Jeannie Vásquez, L Tamayo, Renzo Florez, Sandro Casavilca, M Calderon, J Abugattas, H Gómez, H Fuentes, C Monge-Pimentel, S Song, D Cherry, Laura Fejerman. Tumor and risk factor characteristics among breast cancer patients from different geographic regions in Peru [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4184.

[The association between Cathepsin S and pulmonary function and CT phenotypes in patients with chronic obstructive pulmonary disease]

Objective: To explore the value of cathepsin S in the bronchoalveolar lavage fluid (BALF) of patients with chronic obstructive pulmonary disease (COPD) in the evaluation of pulmonary function and CT phenotypes. Method: From April 2014 to April 2017, 46 patients with stable COPD were enrolled, and 29 healthy volunteers served as the control group. The patients were divided into 4 subgroups: GOLD Ⅰ(n=12), GOLD Ⅱ(n=6), GOLD Ⅲ(n=14), GOLD Ⅳ(n=14). The levels of cathepsin S and IFN-γ in BALF were determined by enzyme-linked immunosorbent assay (ELISA). The percentage ratio of low attenuation area to total lung area (LAA%), two times the ratio of airway wall thickness to outer diameter(2T/D), and the ratio of wall area to total cross-sectional area (WA) were measured by HRCT. Results: There were significant differences in the levels of cathepsin S in BALF between the groups (F=6.639, P=0.000). BALF cathepsin S levels were as follows: GOLD Ⅳ grou P>GOLD Ⅲ grou P>GOLD Ⅱ grou P>GOLD group Ⅰ >healthy control group (P value were all<0.05); LAA grade 3>LAA grade 2>LAA grade 1>LAA grade 0 (P value were all<0.05). Correlation analysis showed that BALF cathepsin S levels were correlated negatively with FEV(1)/FVC, FEV(1)% predicted, and DLCO% (r value was -0.065、-0.576、-0.392, respectively, P value were all<0.05), and but positively with RV/TLC%, LAA%, 2T/D, WA and IFN-γ(r value was 0.695, 0.497, 0.142, 0.309, 0.148, respectively, P value were all<0.05). Conclusion: The levels of cathepsin S were associated with the degree of airflow limitation and emphysema phenotype in COPD.

Effects of Oenanthe javanica on Nitrogen Removal in Free-Water Surface Constructed Wetlands under Low-Temperature Conditions

To investigate the role and microorganism-related mechanisms of macrophytes and assess the feasibility of Oenanthe javanica (Blume) DC. in promoting nitrogen removal in free-water surface constructed wetlands (FWS-CWS) under low temperatures (<10 °C), pilot-scale FWS-CWS, planted with O. javanica, were set up and run for batch wastewater treatment in eastern China during winter. The presence of macrophytes observably improved the removal rates of ammonia nitrogen (65%-71%) and total nitrogen (41%-48%) (p < 0.05), with a sharp increase in chemical oxygen demand concentrations (about 3-4 times). Compared to the unplanted systems, the planted systems not only exhibited higher richness and diversity of microorganisms, but also significantly higher abundances of bacteria, ammonia monooxygenase gene (amoA), nitrous oxide reductase gene (nosZ), dissimilatory cd1-containing nitrite reductase gene (nirS), and dissimilatory copper-containing nitrite reductase gene (nirK) in the substrate. Meanwhile, the analysis of the microbial community composition further revealed significant differences. The results indicate that enhanced abundances of microorganisms, and the key functional genes involved with nitrogen metabolism in the planted systems played critical roles in nitrogen removal from wastewater in FWS-CWS. Furthermore, abundant carbon release from the wetland macrophytes could potentially aid nitrogen removal in FWS-CWS during winter.

[Establishment and evaluation of a triple-color human papillomavirus pseudovirion neutralization assay]

Objective: To establish a triple-color pseudovirion-based neutralization assay (PBNA) and evaluate its capability of detecting immunogenicity of the sera generated by the immunization of HPV 9-valent vaccine. Methods: HPV pseudovirus (PsVs) 6/11/16/18/31/33/45/52/58 with the encapsidated fluorescence expressing red fluorescent plasmid N31-MCHREEY, green fluorescent N31-EGFP or blue fluorescent N31-mTagBFP were generated. The concentration of HPV PsVs and the infection titers of HPV PsVs were detected by double-antibody sandwich ELISA and TCID(50), respectively. The single- and triple color HPV 16/33/45 PsVs were used to detect the neutralization titers of mice sera immunized with HPV 9-valent vaccine and confirmed the accuracy and specificity of the triple-color PBNAs. Then, the single- and triple color HPV 6/11/18/31/33/45/52/58 PsVs were employed to detect the neutralization titers of cynomolgus macaques sera immunized with HPV 9-valent vaccine and determined whether the triple-color PBNAs could be applied to evaluate the immunogenicity of the sera generated by the immunization of HPV9-valent vaccine. Results: The concentration of HPV16 PsVs encapsulating green, red or blue fluorescent plasmid was 5.0 to 6.0 μg/ml and HPV6/11/18/31/33/45/52/59 triple-color HPV PsVs was about 1.0 to 3.0 μg/ml. 9 types HPV PsVs containing EGFP, Mcherry or mTagBFP reporter plasmid were obtained and the concentration can meet the need of neutralization detection. 9 types single-color fluorescent HPV PsVs had similar infectivity against 293FT cells with the infection titer values between 1×10(4) and 1×10(5). The results of PBNAs showed that there was no significant difference in the anti-HPV neutralization titers of mice sera induced by HPV 9-valent vaccine between single-color and triple-color HPV16/33/45 PsVs (P>0.05). Similarly, there was also no significant difference in the anti-HPV neutralization titers of cynomolgus macaques sera induced by HPV 9-valent vaccine between single-color and triple-color HPV6/11/18/31/33/45/52/58 PsVs (P>0.05). Conclusion: We successfully established the triple-color PBNAs and verified the accuracy and specificity of triple-color PBNAs consistent with single-color PBNAs. The triple-color PBNAs can be applied to evaluate the immunogenicity of HPV 9-valent vaccine's immune serum.