Hypertension Prevalence and Control Among U.S. Women of Reproductive Age

INTRODUCTION

Hypertension is a risk factor for cardiovascular disease, a leading cause of death among women of reproductive age (women aged 18-44 years). This study estimated hypertension prevalence and control among women of reproductive age at the national and state levels using electronic health record data.

METHODS

Nonpregnant women of reproductive age were included in this cross-sectional study using 2019 IQVIA Ambulatory Electronic Medical Records - U.S. national data (analyzed in 2023). Suspected hypertension was identified using any of these criteria: ≥1 hypertension diagnosis code, ≥2 blood pressure readings ≥140/90 mmHg on separate days, or ≥1 antihypertensive medication. Among women of reproductive age with hypertension, the latest blood pressure in 2019 was used to identify hypertension control (blood pressure <140/90 mmHg). Estimates were age standardized and stratified by race or Hispanic ethnicity, region, and states with sufficient data. Tukey tests compared estimates by race or Hispanic ethnicity, region, and comorbidities.

RESULTS

Among 2,125,084 women of reproductive age (62.1% White, 8.8% Black, and 29.1% other [including Hispanic, Asian, other, or unknown]) with a mean age of 31.7 years, hypertension prevalence was 14.5%. Of those with hypertension, 71.9% had controlled blood pressure. Black women of reproductive age had a higher hypertension prevalence (22.3% vs 14.4%, p<0.05) but lower control (60.6% vs 74.0%, p<0.05) than White women of reproductive age. State-level hypertension prevalence ranged from 13.7% (Massachusetts) to 36% (Alabama), and control ranged from 82.9% (Kansas) to 59.2% (the District of Columbia).

CONCLUSIONS

This study provides the first state-level estimates of hypertension control among women of reproductive age. Electronic health record data complements traditional hypertension surveillance data and provides further information for efforts to prevent and manage hypertension among women of reproductive age.

Socio-economic disparities in exposure to and endorsement of COVID-19 vaccine misinformation and the associations with vaccine hesitancy and vaccination

OBJECTIVES

We examined disparities in vaccine misinformation exposure and endorsement and the associations with vaccine hesitancy and vaccination uptake.

STUDY DESIGN

Population-based survey.

METHODS

A population-based survey was conducted on 5,002 Hong Kong adults oversampling low socio-economic status (SES, n = 2,200). Information on exposure (13 misinformation statements, total 0-13, median = 2), endorsement (13 statements, score 0-10, high scores indicate higher levels of endorsement, median = 5.75) of misinformation, vaccine hesitancy (14 items, score 1-5), and vaccination (two doses) were collected. Multivariable regression (adjusted β [aβ]) and Poisson regression (adjusted risk ratio [aRR]) adjusting for demographic characteristics were used to examine the associations of exposure to and endorsement of misinformation with vaccine hesitancy and vaccination.

RESULTS

A total of 71.8% of respondents had at least exposure to one vaccine misinformation, and 35.7% had a high level of endorsement (median or above). Respondents with lower SES had a lower exposure (≤2 statements, 57.1% vs 50.1%, P < 0.001) but a higher level of endorsement (36.6% vs 34.9%, P = 0.01) of misinformation. Overall, 72.9% had been vaccinated for two or more doses, with a lower proportion in respondents with lower SES (83.6% vs 61.1%; P < 0.001). Compared with no exposure to misinformation, high levels of exposure and endorsement were associated with vaccine hesitancy (aβ = 0.44, 95% confidence interval 0.40-0.48; aβ = 0.50, 0.47-0.54, respectively) and lower vaccination rates (aRR = 0.98, 0.97-0.99; aRR = 0.92, 0.88-0.96, respectively). Vaccine hesitancy mediated the associations of exposure (fully, 100%) and endorsement (partially, 73%) with vaccination uptake.

CONCLUSION

Endorsement of vaccine misinformation in respondents with lower SES was associated with low vaccination uptake.

Impact of school operating scenarios on COVID-19 transmission under vaccination in the U.S.: an agent-based simulation model

At the height of the COVID-19 pandemic, K-12 schools struggled to safely operate under the fast-changing pandemic situation. However, little is known about the impact of different school operating scenarios considering the ongoing efforts of vaccination. In this study, we deployed an agent-based simulation model to mimic disease transmission in a mid-sized community consisting of 10,000 households. A total of eight school operating scenarios were simulated, in decreasing order of restrictiveness regarding COVID-19 mitigation measures. When masks were worn at school, work, and community environments, increasing in-person education from 50% to 100% would result in only 1% increase in cumulative infections. When there were no masks nor contact tracing while schools were 100% in person, the cumulative infection increased by 86% compared to the scenario when both masking and contact tracing were in place. In the sensitivity analysis for vaccination efficacy, we found that higher vaccination efficacy was essential in reducing overall infections. Our findings showed that full in-person education was safe, especially when contact tracing, masking, and widespread vaccination were in place. If no masking nor contact tracing was practiced, the transmission would rose dramatically but eventually slow down due to herd immunity.

Determinants of influenza vaccine uptake among pregnant women: Demographics and medical care access

OBJECTIVE

To investigate how sociodemographic and medical care access variables are associated with influenza vaccine uptake among pregnant women in the USA.

METHODS

This is an observational study using 2015-2019 data from the US Behavioral Risk Factor Surveillance System. Pregnant women aged 18-49 years were included. Weighted χ² tests and weighted logistic regression models were performed using the software SAS.

RESULTS

A total of 9149 pregnant women were included, of whom 39.9% received the influenza vaccine. Age, income, education and race/ethnicity were significantly associated with influenza vaccination. The following medical access factors were associated with a higher likelihood of receiving the influenza vaccine: having insurance (odds ratio [OR] 1.43, 95% confidence interval [CI] 1.04-1.97), having had a checkup in the past year (OR 1.69, 95% CI 1.40-2.03), and having a primary care provider (OR 1.45, 95% CI 1.18-1.78). In subgroup analysis by race/ethnicity, non-Hispanic black women had the least difference in influenza vaccine uptake between those with medical care access and those without.

CONCLUSION

Our findings suggest that the influenza vaccine uptake level was far from optimal among pregnant women. Influenza vaccine uptake was associated with social demographics and medical care access among pregnant women.

Physical Activity Level and Specific Type of Exercises Among US Middle-Aged and Older Adults: Findings From the Behavioral Risk Factor Surveillance Survey

BACKGROUND

This study aimed to assess physical activity level and identify specific types of exercises by sex, race/ethnicity, and age for adults 50 years and older.

METHODS

Behavioral Risk Factor Surveillance System 2013, 2015, and 2017 data were used to study US adults 50 years and older on their specific types of exercises, stratified by sex, race/ethnicity, and age. Weighted logistic regression was used to model physical exercise level and specific types of exercises.

RESULTS

The sample included 460,780 respondents. Non-Hispanic Black and Hispanic were less likely than non-Hispanic White to meet the recommended physical activity level (Odds ratio [OR] = 0.73, P < .0001 and OR = 0.96, P = .04, respectively). Walking was the most participated type of exercise, followed by gardening, for both men and women, all racial/ethnic groups, and all age groups. Non-Hispanic Blacks were more likely to participate in walking (OR = 1.19, P = .02) and less likely to participate in gardening (OR = 0.65, P < .0001) than non-Hispanic Whites. Men were more likely to engage in strenuous exercises than women. The average number of minutes on walking was the longest among all types of specific exercises.

CONCLUSIONS

The types of exercises were mostly walking and gardening for adults aged 50 and older. Non-Hispanic Black adults had less physical activity than non-Hispanic White and were less likely to engage in gardening.

Influence of social and behavioral determinants on health-related quality of life among cancer survivors in the USA

PURPOSE

Cancer survivors experience a worse health-related quality of life (HRQoL) than non-cancer survivors. However, it is not fully understood whether social determinants of health (SDOH) and health behaviors are significantly associated with HRQoL among cancer survivors. The purpose of this study was to investigate the influence of SDOH and health behaviors on HRQoL among cancer survivors.

METHODS

We identified adult (18 years or older) cancer survivors (n = 5784) in the 2017 and 2019 Behavioral Risk Factor Surveillance System. The primary outcome (HRQoL) was defined as whether cancer survivors reported having poor mental or physical health (e.g., 14 or more mentally or physically unhealthy days). Unadjusted and adjusted logistic regression was used to compute the odds ratios and 95% CIs of factors associated with poor HRQoL among the cancer survivors.

RESULTS

More than half of the cancer survivors were non-Hispanic White, female, and 65 years or older. In the adjusted multivariable logistic regression models, cancer survivors who were physically active and who did not avoid care because of costs had a lower risk of poor mental and physical health. Current smokers were more likely to report poor physical health. Homeowners were less likely to report poor mental health. Daily fruit and vegetable consumption and healthcare coverage were not associated with poor HRQoL.

CONCLUSIONS

Some SDOH (healthcare access, economic stability, and the neighborhood and built environment) and health behavior (physical activity) are associated with lower likelihood of experiencing poor mental and/or physical health in the cancer survivors. The study findings can be used to target survivors who experience suboptimal HRQoL and to inform research, public health policies, and/or programs.

End-of-Life Costs of Cancer Patients With Alzheimer's Disease and Related Dementias in the U.S

CONTEXT

End-of-Life (EOL) care consumes a substantial amount of healthcare resources, especially among older persons with cancer. Having Alzheimer's Disease and Related Dementias (ADRD) brings additional complexities to these patients' EOL care.

OBJECTIVES

To examine the Medicare expenditures at the EOL (last 12 months of life) among beneficiaries having cancer and ADRD vs. those without ADRD.

METHODS

A retrospective cohort study used 2004-2016 Surveillance, Epidemiology, and End Results-Medicare data. Patient populations were deceased Medicare beneficiaries with cancer (breast, lung, colorectal, and prostate) and continuously enrolled for 12 months before death. Beneficiaries with ADRD were propensity score matched with non-ADRD counterparts. Generalized Estimating Equation Model was deployed to estimate monthly Medicare expenditures. Generalized Linear Models were constructed to assess total EOL expenditures.

RESULTS

Eighty six thousand three hundred ninety-six beneficiaries were included (43,198 beneficiaries with ADRD and 43,198 beneficiaries without ADRD). Beneficiaries with ADRD utilized $64,901 at the EOL, which was roughly $407 more than those without ADRD ($64,901 vs. $64,494, P = 0.31). Compared to beneficiaries without ADRD, those with ADRD had 11% higher monthly expenditure and 7% higher in total expenditures. Greater expenditure was incurred on inpatient (5%), skilled nursing facility (SNF) (119%), home health (42%), and hospice (44%) care.

CONCLUSION

Medicare spending at the EOL per beneficiary was not statistically different between cohorts. However, specific types of service (i.e., inpatient, SNF, home health, and hospice) were significantly higher in the ADRD group compared to their non-ADRD counterparts. This study underscored the potential financial burden and informed Medicare about allocation of resources at the EOL.

Perceptions and knowledge regarding the COVID-19 pandemic between U.S. and China: a mixed methods study

BACKGROUND

SARS-CoV-2, a new coronavirus first reported by China on December 31st, 2019, has led to a global health crisis that continues to challenge governments and public health organizations. Understanding COVID-19 knowledge, attitudes, and practices (KAP) is key for informing messaging strategies to contain the pandemic. Cross-national studies (e.g.: comparing China to the U.S.) are needed to better understand how trans-cultural differences may drive differences in pandemic response and behaviors. The goal of the study is to compare knowledge and perceptions of COVID-19 between adults in China and the U.S. These data will provide insight into challenges these nations may face in coordinating pandemic response.

METHODS

This is a convergent mixed methods study comparing responses from China and the U.S. to a multinational COVID-19 KAP online survey. The survey included five quantitative constructs and five open-ended questions. Chinese respondents (n = 56) were matched for gender, age, education, perceived social standing, and time of survey completion with a U.S. cohort (n = 57) drawn from 10,620 U.S.

RESPONDENTS

Quantitative responses were compared using T-test & Fisher-Exact tests. Inductive thematic analysis was applied to open-ended questions.

RESULTS

Both U.S. and Chinese samples had relatively high intention to follow preventive behaviors overall. Differences in intended compliance with a specific recommendation appear to be driven by the different cultural norms in U.S. and China. Both groups expressed trepidation about the speed of COVID-19 vaccine development, driven by concern for safety among Chinese respondents, and concern for efficacy among U.S.

RESPONDENTS

The Chinese cohort expressed worries about other countries' passive handling of the pandemic while the U.S. cohort focused on domestic responses from individuals and government. U.S. participants appeared more knowledgeable on some aspects of COVID-19. Different perspectives regarding COVID-19 origins were identified among the two groups. Participants from both samples reported high trust in health professionals and international health organizations.

CONCLUSIONS

Mixed methods data from this cross-national analysis suggests sociocultural differences likely influence perceptions and knowledge of COVID-19 and its related public health policies. Discovering and addressing these culturally-based differences and perceptions are essential to coordinate a global pandemic response.

Healthy Eating Index (HEI) Scores Differ by Race/Ethnicity But Not Hypertension Awareness Status Among US Adults with Hypertension: Findings from 2011-2018 National Health and Nutrition Examination Survey

BACKGROUND

Little is known about whether diet quality is associated with race/ethnicity as well as hypertension awareness status among adults with hypertension.

OBJECTIVE

The aim of this study was to examine associations between diet quality and race/ethnicity as well as hypertension awareness.

DESIGN

Analysis of the 2011-2018 National Health and Nutrition Examination Survey (NHANES), a cross-sectional survey representative of the U.S.

POPULATION

PARTICIPANTS/SETTING

A total of 6,483 participants with hypertension who were at least 18 years old and had dietary recall data were included.

MAIN OUTCOME MEASURES

Diet quality was assessed by Healthy Eating Index (HEI)-2015.

STATISTICAL ANALYSIS PERFORMED

Weighted chi-square tests were employed to test associations between categorical variables. Weighted linear regression was used to model the HEI-2015 score by various covariates.

RESULTS

Among the 6,483 participants with hypertension included in this study, the average HEI-2015 total score was 54.0 out of the best possible score of 100. In unadjusted analysis, the HEI-2015 total score was significantly different by race/ethnicity (P<0.01), being 60.9 for Non-Hispanic Asian (NHA) participants, 54.4 for Hispanic, 53.8 for non-Hispanic White (NHW), and 52.7 for non-Hispanic Black (NHB) participants. The HEI-2015 component scores were statistically different by race/ethnicity for all the 13 components (all P<0.01). In adjusted analysis, race/ethnicity was significantly associated with the total HEI-2015 score (P<0.0001), but hypertension awareness status was not (P=0.99), after controlling for age, sex, BMI, marital status, educational level, income level and insurance status.

CONCLUSIONS

There were significant racial/ethnic differences in HEI-2015 scores among participants with hypertension. Hypertension awareness status was not associated with HEI-2015 scores. Further study is needed to identify reasons why there was an association between HEI-2015 scores and race/ethnicity, and a lack of association with hypertension awareness.

Effects of evaporative cooling and dietary zinc source on heat shock responses and mammary gland development in lactating dairy cows during summer

The objective of this study was to examine the effects of evaporative cooling and dietary supplemental Zn source on heat shock responses and mammary gland development of lactating dairy cows during summer. Seventy-two multiparous lactating Holstein cows were randomly assigned to 1 of 4 treatments in a 2 × 2 factorial arrangement. Cows were either cooled (CL) or not cooled (NC) and fed diets supplemented with 75 mg of Zn/kg of dry matter (DM) from Zn hydroxychloride (IOZ) or 35 mg of Zn/kg of DM from Zn hydroxychloride plus 40 mg of Zn/kg of DM from Zn-Met complex (ZMC). The 168-d trial included a 12-wk baseline phase when all cows were cooled and fed respective dietary treatments, and a subsequent 12-wk environmental challenge phase when NC cows were deprived of evaporative cooling. Plasma was collected from a subset of cows (n = 24) at 1, 3, 5, 12, 26, 41, 54, 68, 81 d of the environmental challenge to measure heat shock protein (HSP) 70 concentration. Mammary biopsies were collected from another subset of cows (n = 30) at enrollment (baseline samples) and at d 7 and 56 of the environmental challenge to analyze gene expression related to heat shock response, apoptosis and anti-oxidative enzymes, and to examine apoptosis and cell proliferation using immunohistochemistry. Supplemental Zn source did not affect milk yield but NC cows produced less milk than CL cows. Supplemental Zn source had no effect on mammary gene expression of HSP27, 70, and 90 or plasma concentrations of HSP70. The NC cows had greater mammary gene expression of HSP than CL cows. Circulating HSP70 of NC cows gradually increased and was higher at 81 d of environmental challenge compared with CL cows. Relative to IOZ, ZMC cows tended to have lower total mammary cell proliferation but greater mammary apoptosis. There was a tendency of greater TNFRSF1A mRNA expression for ZMC compared with IOZ cows, which may suggest upregulated extrinsic apoptosis. At d 7 of environmental challenge, NC cows had numerically higher mammary apoptosis than CL cows although not statistically significant. The NC cows tended to have greater mRNA expression of CAT and SOD3 regardless of time, and had greater mRNA expression of GPX1 at d 56 and FAS at d 7 of the environmental challenge than CL cows. Relative to CL cows, mammary cell proliferation rate was higher for NC cows at d 56 of the environmental challenge. In conclusion, dietary source of supplemental Zn has substantial effect on mammary cell turnover in lactating dairy cows, and prolonged exposure to heat stress increases mammary cell proliferation.

Compare Breast Cancer Screening, Diagnosis, and Treatment Between Medicare Patients With and Without ADRD

Background: Incidence of both breast cancer and Alzheimer’s disease and related dementias (ADRD) increases with advancing age. Little research has delineated breast cancer screening, diagnosis, and treatment among women with ADRD. Method: Surveillance, Epidemiology, and End Results (SEER)-Medicare linked data were used. Female breast cancer patients diagnosed between 2005-2015 were identified. Chi-square tests were conducted to compare the characteristics of two groups with and without ADRD. Multiple logistic regression models were estimated to explain the diagnosis and treatment differences. Results: A total of 44,112 female Medicare beneficiaries age 65 or older were identified. Patients with ADRD (17.5%) were less likely to receive breast cancer screening (42.8% vs. 46.6% for all data years combined, p<0.0001), more likely to be diagnosed with breast cancer after death by autopsy or death certificate (8.1% vs 2.0%, p<0.0001). Among those who are diagnosed before death, patients with ADRD were more likely to be diagnosed with breast cancer at age 75 and older (84.8% vs. 15.2%, p<0.0001). After adjusting for age, race, poverty level, marital status, cancer stage at diagnosis, cancer screening history, wellness visit history, comorbidity, and rural/urban residence, logistic regressions suggest that patients with ADRD were less likely to receive surgery (AOR=0.48, 95%CI: 0.45-0.52), radiation (AOR=0.41, 95%CI: 0.39-0.44), or chemotherapy (AOR=0.38, 95%CI: 0.35-0.41). Conclusion: Breast cancer screening was less utilized and breast cancer was diagnosed at an older age in patients with ADRD than those without. Treatments (surgery, radiation, and chemotherapy) were given less frequently to patients with ADRD.

Association between blood lead levels and blood pressure in American adults: results from NHANES 1999-2016

The aim of this study was to investigate the association between blood lead level (BLL) and hypertension in adults when lead exposure for the general population is low. The study used data from the US National Health and Nutrition Examination Survey (NHANES) 1999-2016. Participants aged 20 to 79 years were included in our study. Weighted multiple linear regression and logistic regression were conducted to test the association between BLL and systolic/diastolic blood pressure and hypertension status, respectively, while controlling for age, gender, race/ethnicity, body mass index, income level, and education. A total of 30,467 participants were included in this study. There was no association between BLL and hypertension status for the overall sample. Among those who were not taking antihypertensive medication, after adjusting for covariates, systolic blood pressure was positively correlated with BLL in non-Hispanic Whites (P = 0.004) and non-Hispanic Blacks (P = 0.0005), but not Hispanics (P = 0.07) nor Others (P = 0.37). The relationship between diastolic blood pressure and lead levels was also significant in non-Hispanic Whites and non-Hispanic Blacks. This study showed that higher BLL was associated with higher systolic and diastolic blood pressure in some population groups, but not associated with hypertension status.

Inhibition of CD44 attenuates pressure overload-induced cardiac and lung inflammation, fibrosis, and heart failure progression

Background

Inflammation contributes to heart failure (HF) development and progression. CD44 is a member of the hyaluronate receptor family of cell adhesion molecules, which regulates tissue inflammation and fibrosis through modulating macrophage and lymphocyte migration and homing in several diseases. Here we evaluated the role and cellular mechanism of CD44 in regulating transverse aortic constriction (TAC)-induced HF development and progression in mice.

Methods and results

C57/B6 background CD44 KO and wild type mice (6–8 weeks) were subjected to TAC to evaluate the effect of CD44 on the development of TAC-induced LV hypertrophy and cardiac dysfunction. Due to the rapid response to TAC, Balb/c mice (6–8 weeks) were used to determine the effect of CD44 on the progression of TAC-induced congestive heart failure. We found that CD44 expression is dramatically increased in left ventricular (LV) tissues obtained from HF patients and mice. While CD44 gene knockout (KO) has no detectable effect on cardiac structure and function under control conditions, CD44 KO mice were protected from TAC-induced LV inflammation, fibrosis, hypertrophy, dysfunction, and lung remodeling as compared with wild type mice. In addition, we found that inhibition of CD44 signaling with blocking antibodies (Abs) significantly attenuated the transition from LV failure to lung remodeling, and right ventricular hypertrophy in mice with existing HF.

Conclusions

These data identify an important role of CD44 in attenuating cardiac and lung inflammation, fibrosis, HF development, and HF progression, suggesting that inhibition of CD44 signaling may be useful in preventing and treating HF.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Chinese National Natural Science Foundation Grants and American Heart Association

Racial and gender disparities in stage at diagnosis for bladder cancer: Results from the surveillance, epidemiology, and end results (SEER) program, 2007 to 2016

e17032

Background: Little is known about the patterns of racial and gender disparities in bladder cancer (BC). This study will use national large database to explore those disparities. Methods: Data from the National Cancer Institute’sSurveillance, Epidemiology, and End Results (SEER) Program for cancer registries was used. Patients > = 18 years diagnosed with BC in the years 2007-2016 were identified from SEER 18 database. We used the data year 2007 because that was the year when insurance status was first collected in SEER. Chi-square tests and multinomial logistic regression were used. Results: A total of 78,151 (females: 25.58%) patients were included, with 82.74% being non-Hispanic whites, 5.83% non-Hispanic blacks, 6.69 % Hispanics and 4.74% others. Distribution of stage 0 through stage IV at diagnosis was 51.97%, 23.21%, 12.11%, 4.10% and 8.61% respectively. Blacks (P < 0.0001) and females (P < 0.0001) were diagnosed at later stages as in Table. e.g., 14.54% of blacks were diagnosed at stage IV, compared to 7.97% of whites; and 11.03% of females at stage IV vs. 7.77% of males. Racial disparity exists for any given insurance status. Within every age group, gender disparity exists. For example, for those under 50 years of age, 12.81% of women vs. 8.16% of men were diagnosed at stage IV. After controlling for age, marital status and insurance type, both gender (P < 0.0001) and race (P < 0.0001) were statistically significant in predicting stage at diagnosis. Conclusions: Racial disparity in stage at BC diagnosis was strong, with blacks suffering most from the disparity. Females were more likely to be diagnosed at later stages, and this gender disparity exists in all age groups and was not due to women living longer. The existence of both racial and gender disparities in BC makes black women most vulnerable to late diagnosis than any other racial/gender group. Oncologists treating BC patients should be aware of the racial and gender disparity. More research needs to be done to help improve early access to health care amongst female and minority BC patients. [Table: see text]

Association Between Subjective Cognitive Decline and Social and Emotional Support in US Adults

Subjective cognitive decline (SCD) has been linked to Alzheimer's Disease in the literature. However, little is known about whether SCD is associated with social/emotional support (SES). To investigate this association, this study utilized the 2015 and 2016 Behavioral Risk Factor Surveillance System data. A study population of 17206 participants aged 45 years and older who responded to both the Emotional Support and Life Satisfaction survey module and the Cognition Decline survey module were included. Of this study population, 11.22% had SCD, and 21.83% reported insufficient SES. A much higher percentage of those with insufficient SES experienced SCD compared to those with sufficient SES (21.15% vs 8.45%, P < .0001). Insufficient SES was significantly associated with SCD (odds ratio = 1.68, 95% confidence interval: 1.37-2.06), after controlling for other factors. Furthermore, this study found certain demographic groups such as female, white, or married groups were more likely to receive sufficient SES.

Porcine insulin receptor substrate 2: molecular cloning, tissues distribution, and functions in hepatocyte and aortic endothelial cells

Insulin receptor substrate 2 (IRS-2) modulates the phosphatidylinositol 3-kinase (PI3K)/Akt pathway, which controls the suppression of gluconeogenic genes; IRS-2 is also a critical node of insulin signaling. Because of the high homology between pig and human IRS-2, we investigated the expression pattern and function of porcine IRS-2. QPCR and immunoblotting were used to detect the IRS-2 expression level in different tissues. There were high IRS-2 levels in the cerebral cortex, hypothalamus, and cerebellum in the central nervous system. In peripheral tissues, IRS-2 was expressed at relatively high levels in the liver. Immunohistochemistry analysis revealed that IRS-2 was mainly distributed in the hypothalamus and cerebral cortex. Furthermore, IRS-2 knockdown porcine hepatocytes and porcine aortic endothelial cells (PAECs) were generated. The IRS-2 knockdown induced abnormal expression of genes involved in glycolipid metabolism in hepatocytes and reduced the antiatherosclerosis ability in PAECs. In addition, we disrupted IRS-2 in porcine embryonic fibroblasts (PEFs) using the CRISPR/Cas9 genome editing system, before finally generating IRS-2 knockout embryos by somatic cell nuclear transfer (SCNT). Taken together, our results indicate that IRS-2 might be a valuable target to establish diabetes and vascular disease models in the pig.

Risk factors of perioperative complications and transfusion following total hip arthroplasty in systemic lupus erythematosus patients

BACKGROUND

In recent years, hip arthroplasty rates in systemic lupus erythematosus (SLE) patients have been increasing rapidly. Although patients with SLE generally show beneficial or desirable functional outcomes following total hip arthroplasty (THA), it has been reported that SLE patients after THA have increased risk of postoperative complications, especially during the period of hospitalization.

OBJECTIVES

In the present study, we aimed to identify possible factors associated with complications or transfusion of THA in SLE patients during hospitalization.

METHODS

The present study was a retrospective study conducted in Peking Union Medical College Hospital. Data were collected from medical records of patients who underwent THA from January 2012 to June 2018. The primary outcome variable was perioperative complications, which was defined as having one or more of the following conditions: high fever, infection, impaired wound healing, venous thrombosis of the lower extremities, hematoma, arrhythmia, implant complications. The secondary outcome was perioperative transfusion.

RESULTS

During January 2012 to June 2018, 100 patients had taken the surgery of THA. After multivariate analysis, independent risk factors for perioperative complications were: age ≥ 45 years (p = 0.001), SLE with other connective tissue diseases (p = 0.029), high temperature (p = 0.030), positive anti-dsDNA antibody (p = 0.043), and Systemic Lupus International Collaborative Clinics/American College of Rheumatology (SLICC/ACR) Damage Index ≥ 3 (p = 0.008). Independent risk factors for perioperative transfusion were bilateral THA (p = 0.029), low hemoglobin (p = 0.021) and abnormal renal function (p = 0.021).

CONCLUSION

For SLE patients following THA, age > 45 years, SLE with other connective tissue disease, high temperature, positive anti-dsDNA antibody and SLICC/ACR Damage Index ≥ 3 were the risk factors of complications during hospitalization and bilateral THA, low hemoglobin and abnormal renal function were the risk factors of transfusion.

Membrane potential oscillations are not essential for spontaneous firing generation in L4 Aβ-afferent neurons after L5 spinal nerve axotomy and are not mediated by HCN channels

NEW FINDINGS

What is the central question of this study? Is spontaneous activity (SA) in L4 dorsal root ganglion (DRG) neurons induced by L5 spinal nerve axotomy associated with membrane potential oscillations in these neurons, and if so, are these membrane oscillations mediated by HCN channels? What is the main finding and its importance? Unlike injured L5 DRG neurons, which have been shown to be incapable of firing spontaneously without membrane potential oscillations, membrane potential oscillations are not essential for SA generation in conducting 'uninjured' L4 neurons, and they are not mediated by HCN channels. These findings suggest that the underlying cellular mechanisms of SA in injured and 'uninjured' DRG neurons induced by spinal nerve injury are distinct.

ABSTRACT

The underlying cellular and molecular mechanisms of peripheral neuropathic pain are not fully understood. However, preclinical studies using animal models suggest that this debilitating condition is driven partly by aberrant spontaneous activity (SA) in injured and uninjured dorsal root ganglion (DRG) neurons, and that SA in injured DRG neurons is triggered by subthreshold membrane potential oscillations (SMPOs). Here, using in vivo intracellular recording from control L4-DRG neurons, and ipsilateral L4-DRG neurons in female Wistar rats that had previously undergone L5 spinal nerve axotomy (SNA), we examined whether conducting 'uninjured' L4-DRG neurons in SNA rats exhibit SMPOs, and if so, whether such SMPOs are associated with SA in those L4 neurons, and whether they are mediated by hyperpolarization-activated cyclic nucleotide gated (HCN) channels. We found that 7 days after SNA: (a) none of the control A- or C-fibre DRG neurons showed SMPOs or SA, but 50%, 43% and 0% of spontaneously active cutaneous L4 Aβ-low threshold mechanoreceptors, Aβ-nociceptors and C-nociceptors exhibited SMPOs, respectively, in SNA rats with established neuropathic pain behaviors; (b) neither SMPOs nor SA in L4 Aβ-neurons was suppressed by blocking HCN channels with ZD7288 (10 mg kg^-1 , i.v.); and (c) there is a tendency for female rats to show greater pain hypersensitivity than male rats. These results suggest that SMPOs are linked to SA only in some of the conducting L4 Aβ-neurons, that such oscillations are not a prerequisite for SA generation in those L4 A- or C-fibre neurons, and that HCN channels are not involved in their electrogenesis.

Growth of vertically aligned nanowires in metal-oxide nanocomposites: kinetic Monte-Carlo modeling versus experiments

We employ kinetic Monte-Carlo simulations to study the growth process of metal-oxide nanocomposites obtained via sequential pulsed laser deposition. Using Ni-SrTiO3 (Ni-STO) as a model system, we reduce the complexity of the computational problem by choosing a coarse-grained approach mapping Sr, Ti and O atoms onto a single effective STO pseudo-atom species. With this ansatz, we scrutinize the kinetics of the sequential synthesis process, governed by alternating deposition and relaxation steps, and analyze the self-organization propensity of Ni atoms into straight vertically aligned nanowires embedded in the surrounding STO matrix. We finally compare the predictions of our binary toy model with experiments and demonstrate that our computational approach captures fundamental aspects of self-assembled nanowire synthesis. Despite its simplicity, our modeling strategy successfully describes the impact of relevant parameters like the concentration or laser frequency on the final nanoarchitecture of metal-oxide thin films grown via pulsed laser deposition.

Transgenic characterization of two silkworm tissue-specific promoters in the haemocyte plasmatocyte cells

Haemocytes play crucial roles in insect metabolism, metamorphosis, and innate immunity. As a model of lepidopteran insects, the silkworm is a useful model to study the functions of both haematopoiesis and haemocytes. Tissue-specific promoters are excellent tools for genetic manipulation and are widely used in fundamental biological research. Herein, two haemocyte-specific genes, Integrin β2 and Integrin β3, were confirmed. Promoter activities of Integrin β2 and Integrin β3 were evaluated by genetic manipulation. Quantitative real-time PCR and western blotting suggested that both promoters can drive enhanced green fluorescent protein (EGFP) specifically expressed in haemocytes. Further evidence clearly demonstrated that the transgenic silkworm exhibited a high level of EGFP signal in plasmatocytes, but not in other detected haemocyte types. Moreover, EGFP fluorescence signals were observed in the haematopoietic organ of both transgenic strains. Thus, two promoters that enable plasmatocytes to express genes of interest were confirmed in our study. It is expected that the results of this study will facilitate advances in our understanding of insect haematopoiesis and immunity in the silkworm, Bombyx mori.

Effects of heat stress and dietary zinc source on performance and mammary epithelial integrity of lactating dairy cows

Dietary Zn and heat stress alter gut integrity in monogastric animals. However, effects of Zn on mammary epithelial integrity in heat-stressed lactating dairy cows have not been studied. Multiparous lactating Holstein cows (n = 72) were randomly assigned to 1 of 4 treatments with a 2 × 2 factorial arrangement to study the effects of environment and Zn source on performance and mammary epithelial integrity. Treatments included 2 environments [cooled (CL) or not cooled (NC)] and 2 Zn sources [75 mg/kg of supplemental Zn as Zn hydroxychloride (IOZ) or 35 mg/kg of Zn hydroxychloride + 40 mg/kg of Zn-Met complex (ZMC)]. The experiment was divided into baseline and environmental challenge phases of 84 d each. All cows were cooled during the baseline phase (temperature-humidity index = 72.5), whereas NC cows were not cooled during environmental challenge (temperature-humidity index = 77.7). Mammary biopsies were collected on d 7 and 56 relative to the onset of environmental challenge to analyze gene expression of claudin 1, 4, and 8, zonula occludens 1, 2, and 3, occludin, and E-cadherin and protein expression of occludin and E-cadherin. Deprivation of cooling increased respiration rate (64.8 vs. 73.9 breaths/min) and vaginal temperature (39.03 vs. 39.94°C) and decreased dry matter intake (26.7 vs. 21.6 kg/d). Energy-corrected milk yield decreased for NC cows relative to CL cows (24.5 vs. 34.1 kg/d). An interaction between environment and Zn source occurred for milk fat content as CL cows fed ZMC had lower milk fat percentage than other groups. Relative to CL cows, NC cows had lower concentrations of lactose (4.69 vs. 4.56%) and solids-not-fat (8.46 vs. 8.32%) but a higher concentration of milk urea nitrogen (9.07 vs. 11.02 mg/mL). Compared with IOZ, cows fed ZMC had lower plasma lactose concentration during baseline and tended to have lower plasma lactose concentration during environmental challenge. Plasma lactose concentration tended to increase at 3, 5, and 41 d after the onset of environmental challenge in NC cows relative to CL cows. Treatment had no effect on milk BSA concentration. Cows fed ZMC tended to have higher gene expression of E-cadherin relative to IOZ. Compared with CL, NC cows had increased gene expression of occludin and E-cadherin and tended to have increased claudin 1 and zonula occludens 1 and 2 gene expression in the mammary gland. Protein expression of occludin and E-cadherin was unchanged. In conclusion, removing active cooling impairs lactation performance and affects gene expression of proteins involved in the mammary epithelial barrier, and feeding a portion of dietary zinc as ZMC improves the integrity of the mammary epithelium.

The effect of aspirin on circulating tumor cells in metastatic colorectal and breast cancer patients: a phase II trial study

PURPOSE

Aspirin could reduce the risk of cancer metastasis. Circulating tumor cells (CTCs) are a key factor of cancer metastasis, but no evidence has revealed how aspirin affects CTCs and its epithelial-mesenchymal transition (EMT). Here, we conducted a clinical trial to investigate how aspirin affects CTCs in metastatic colorectal cancer (MCC) and breast cancer patients (MBC).

METHODS

The trial is retrospective registered at clinicaltrials.gov (NCT02602938). The eligible patients are given 100 mg aspirin q.d. for 8 weeks, and CTCs are evaluated at baseline, 4 and 8 weeks for absolute number, phenotype (epithelial type, E+, mesenchymal type, M+, and biophenotypic type, B+), and vimentin expression.

RESULTS

Data on 21 MCC and 19 MBC patients are analyzed, and it revealed that the CTC numbers decreased with aspirin treatment in MCC (p < 0.001) but not MBC (p = 0.0532); besides, ratio of E+ CTCs increased (p = 0.037) and M+ CTCs decreased at 2 months in MCC (p = 0.013), but neither the ratio of E+ or M+ CTCs changes significantly in MBC; vimentin expression of M+ CTCs is higher than E+ and B+ CTCs either in MBC or MCC patients at baseline (p < 0.01); and aspirin suppresses the vimentin expression in M+ (p = 0.002)and B+ (p = 0.006) CTCs of MCC and M+ CTCs of MBC (p = 0.004); besides it find vimentin expression in B+ (p = 0.004) or M+ (p < 0.001), CTCs are markedly decreased in patients with total CTC numbers declined.

CONCLUSION

Aspirin could decrease CTCs numbers and block EMT transition in MCC patients and part of MBC patients.

Butylated caffeic acid: An efficient novel antioxidant

A novel antioxidant, butylated caffeic acid (BCA) was rationally designed by adding a tert-butyl group to caffeic acid, which was synthesized at a high yield (36.2%) from 2-methoxy-4-methylphenol by a four-step reaction including Friedel-Crafts alkylation, bromine oxidation, ether bond hydrolysis and Knoevenagel condensation. Its antioxidant capacity was much stronger than common commercial antioxidant tert-butyl hydroquinone (TBHQ) and its mother compound, caffeic acid, in both rancimat and deep frying tests. When investigated via the DPPH method, the antioxidant capacity of BCA was almost equal to TBHQ, but lower than caffeic acid. BCA could be a potentially strong antioxidant, especially for food processing at high temperatures such as deep frying and baking.

Vertebral fracture in postmenopausal Chinese women: a population-based study

In a random sample of postmenopausal Chinese women, the prevalence of radiographic vertebral fractures increased from 13% between ages 50 and 59 to over 50% after age 80 years. A model with seven clinical risk factors predicted the probability of vertebral fractures as well with as without BMD and better than a model with only three risk factors. More than half an hour of outdoor activity per day might correlate with lower risk of vertebral fracture in this population.

INTRODUCTION

We aimed to describe the prevalence and develop a model for prediction of radiographic vertebral fractures in a large random sample of postmenopausal Chinese women.

METHODS

We enrolled 1760 women from an age-stratified random sample of postmenopausal women in Beijing, China. The presence of vertebral fracture was assessed by semi-quantitative grading of lateral thoracolumbar radiographs, risk factors by interview, bone mineral density (BMD) of the proximal femur and lumbar spine by dual x-ray absorptiometry (DXA), and markers of bone turnover from a fasting blood sample. Associations of these factors were analyzed in logistic models and discrimination by areas of receiver operating characteristics curves (AUC).

RESULTS

The prevalence of vertebral fracture, ranged from 13.4% ages 50 to 59 years old to 58.1% at age 80 years or older. Older age, a history of non-vertebral fracture, lower femoral neck BMD T-score, body mass index (BMI), height loss, housework, and less than half an hour of outdoor activity were significantly associated with increased probability of having a vertebral fracture. A model with those seven factors had a similar AUC with or without BMD and performed better than a simple model with three factors.

CONCLUSION

This study is from a true random sample of postmenopausal women in urban China with high response rate. The prevalence of vertebral fractures in postmenopausal women in Beijing increases from 13% under age 60 to over 50% by age 80 years. A model with seven clinical risk factors with or without BMD is better than simple models and may guide the use of spine x-rays to identify women with vertebral fractures. More than half an hour of outdoor activity might correlate with lower risk of vertebral fracture in this population.

[Overexpression of Keap1 inhibits the cell proliferation and metastasis and overcomes the drug resistance in human lung cancer A549 cells]

OBJECTIVE

To investigate the effect of Keap1-Nrf2 pathway on cell proliferation, metastasis and drug resistance of human lung cancer A549 cell line.

METHODS

A549-Keap1 cell line, constantly expressing wild type Keap1, was established by lentiviral transfection. Real-time RT-PCR and western blot were used to determine the expression of Nrf2 and its target gene in A549 cells. Sulforhodamine B (SRB) assay, flow cytometry, colony formation assay, transwell assay, and cell wound-healing assay were performed to explore the effect of wild type Keap1 expression on the proliferation, invasion, migration and drug resistance of A549 cells.

RESULTS

Over-expressed Keap1 decreased the expression of Nrf2 protein and the mRNA level of its downstream target genes and inhibited the ability of cell proliferation and clone formation of A549 cells. Keap1 overexpression induced G0/G1 phase arrest. The percentage of A549-Keap1 cells in G0/G1 phase was significantly higher than that of A549-GFP cells (80.2±5.9)% vs. (67.1±0.9%)(P<0.05). Compared with the invasive A549-Keap1 cells (156.33±17.37), the number of invasive A549-GFP cells was significantly higher (306.67±22.19) in a high power field. Keap1 overexpression significantly enhanced the sensitivity of A549 cells to carboplatin and gemcitabine (P<0.01). The IC50s of carboplatin in A549-Keap1 and A549-GFP cells were (52.1±3.3) μmol/L and (107.8±12.9) μmol/L, respectively. The IC50s of gemcitabine in A549-Keap1 and A549-GFP cells were (6.8±1.2) μmol/L and (9.9±0.5) μmol/L, respectively.

CONCLUSION

Keap1 overexpression significantly inhibits the expression of Nrf2 and its downstream target genes, suppresses tumor cell proliferation and metastasis, and enhances the sensitivity of A549 cells to anticancer drugs.

miR-216a rescues dexamethasone suppression of osteogenesis, promotes osteoblast differentiation and enhances bone formation, by regulating c-Cbl-mediated PI3K/AKT pathway

Osteoporosis is a disease marked by reduced bone mass, leading to an increased risk of fractures or broken bones. Bone formation is mediated by recruiting mesenchymal stem cells (MSCs). Elucidation of the molecular mechanisms that regulate MSC differentiation into osteoblasts is of great importance for the development of anabolic therapies for osteoporosis and other bone metabolism-related diseases. microRNAs (miRNAs) have been reported to have crucial roles in bone development, osteogenic differentiation and osteoporosis pathophysiology. However, to date, only a few miRNAs have been reported to enhance osteogenesis and regulate the suppressive effect of glucocorticoids on osteogenic differentiation. In this study, we discovered that miR-216a, a pancreatic-specific miRNA, was significantly upregulated during osteogenic differentiation in human adipose-derived MSCs (hAMSCs). The expression of miR-216a was positively correlated with the expression of bone formation marker genes in clinical osteoporosis samples. Functional analysis demonstrated that miR-216a can markedly promote osteogenic differentiation of hAMSCs, rescue the suppressive effect of dexamethasone (DEX) on osteogenic differentiation in vitro and enhance bone formation in vivo. c-Cbl, a gene that encodes a RING finger E3 ubiquitin ligase, was identified as a direct target of miR-216a. Downregulation of c-Cbl by short hairpin RNAs can mimic the promotion effects of miR-216a and significantly rescue the suppressive effects of DEX on osteogenesis. Pathway analysis indicated that miR-216a regulation of osteogenic differentiation occurs via the c-Cbl-mediated phosphatidylinositol 3 kinase (PI3K)/AKT pathway. The recovery effects of miR-216a on the inhibition of osteogenesis by DEX were attenuated after blocking the PI3K pathway. Thus, our findings suggest that miR-216a may serve as a novel therapeutic agent for the prevention and treatment of osteoporosis and other bone metabolism-related diseases.

Persistent hindlimb inflammation induces changes in activation properties of hyperpolarization-activated current (Ih) in rat C-fiber nociceptors in vivo

A hallmark of chronic inflammation is hypersensitivity to noxious and innocuous stimuli. This inflammatory pain hypersensitivity results partly from hyperexcitability of nociceptive dorsal root ganglion (DRG) neurons innervating inflamed tissue, although the underlying ionic mechanisms are not fully understood. However, we have previously shown that the nociceptor hyperexcitability is associated with increased expression of hyperpolarization-activated cyclic nucleotide-gated channel 2 (HCN2) protein and hyperpolarization-activated current (Ih) in C-nociceptors. Here we used in vivo voltage-clamp and current-clamp recordings, in deeply anesthetized rats, to determine whether activation properties of Ih in these C-nociceptors also change following persistent (not acute) hindlimb inflammation induced by complete Freund's adjuvant (CFA). Recordings were made from lumbar (L4/L5) C-nociceptive DRG neurons. Behavioral sensory testing was performed 5-7days after CFA treatment, and all the CFA-treated group showed significant behavioral signs of mechanical and heat hypersensitivity, but not spontaneous pain. Compared with control, C-nociceptors recorded 5-7days after CFA showed: (a) a significant increase in the incidence of spontaneous activity (from ∼5% to 26%) albeit at low rate (0.14±0.08Hz (Mean±SEM); range, 0.01-0.29Hz), (b) a significant increase in the percentage of neurons expressing Ih (from 35%, n=43-84%, n=50) based on the presence of voltage "sag" of >10%, and (c) a significant increase in the conductance (Gh) of the somatic channels conducting Ih along with the corresponding Ih,Ih, activation rate, but not voltage dependence, in C-nociceptors. Given that activation of Ih depolarizes the neuronal membrane toward the threshold of action potential generation, these changes in Ih kinetics in CFA C-nociceptors may contribute to their hyperexcitability and thus to pain hypersensitivity associated with persistent inflammation.

TBX6 null variants and a common hypomorphic allele in congenital scoliosis

BACKGROUND

Congenital scoliosis is a common type of vertebral malformation. Genetic susceptibility has been implicated in congenital scoliosis.

METHODS

We evaluated 161 Han Chinese persons with sporadic congenital scoliosis, 166 Han Chinese controls, and 2 pedigrees, family members of which had a 16p11.2 deletion, using comparative genomic hybridization, quantitative polymerase-chain-reaction analysis, and DNA sequencing. We carried out tests of replication using an additional series of 76 Han Chinese persons with congenital scoliosis and a multicenter series of 42 persons with 16p11.2 deletions.

RESULTS

We identified a total of 17 heterozygous TBX6 null mutations in the 161 persons with sporadic congenital scoliosis (11%); we did not observe any null mutations in TBX6 in 166 controls (P<3.8×10(-6)). These null alleles include copy-number variants (12 instances of a 16p11.2 deletion affecting TBX6) and single-nucleotide variants (1 nonsense and 4 frame-shift mutations). However, the discordant intrafamilial phenotypes of 16p11.2 deletion carriers suggest that heterozygous TBX6 null mutation is insufficient to cause congenital scoliosis. We went on to identify a common TBX6 haplotype as the second risk allele in all 17 carriers of TBX6 null mutations (P<1.1×10(-6)). Replication studies involving additional persons with congenital scoliosis who carried a deletion affecting TBX6 confirmed this compound inheritance model. In vitro functional assays suggested that the risk haplotype is a hypomorphic allele. Hemivertebrae are characteristic of TBX6-associated congenital scoliosis.

CONCLUSIONS

Compound inheritance of a rare null mutation and a hypomorphic allele of TBX6 accounted for up to 11% of congenital scoliosis cases in the series that we analyzed. (Funded by the National Basic Research Program of China and others.).

Histological improvement of long-term antiviral therapy in chronic hepatitis B patients with persistently normal alanine aminotransferase levels

The aim of this study was to evaluate the histological outcomes of chronic hepatitis B (CHB) patients with persistently normal alanine aminotransferase (ALT) levels after long-term antiviral therapy. Paired liver biopsies before and after lamivudine (LAM) treatment in CHB patients with normal and elevated ALT levels were compared. Histological response was defined as a 1-point decrease according to the Scheuer scoring system, without worsening of fibrosis between pretreatment and posttreatment biopsies. Among the 48 patients who underwent paired liver biopsies, 17 had persistently normal baseline ALT level and 31 had elevated ALT level. The median age of the patients was 44 years and 72.9% of the patients were male. The median duration of antiviral treatment was 44.5 months (range 14-104). Long-term follow-up of liver biopsies revealed that 82.4% of patients in the normal ALT group and 61.3% in the elevated ALT group had a baseline fibrosis score of 4, which was reduced to 17.6% and 38.7% after long-term therapy, respectively, indicating reversal of cirrhosis in a large proportion of both groups, especially in patients with normal baseline ALT levels. Long-term antiviral treatment could achieve significant histological improvement in CHB patients with fibrosis or cirrhosis, regardless of ALT level.

Evaluation of the GenoType® MTBDRplus assay and identification of a rare mutation for improving MDR-TB detection

OBJECTIVE

To assess the new GenoType® MTBDRplus assay for the rapid detection of multidrug-resistant tuberculosis (MDR-TB) in comparison with DNA sequencing to identify drug resistance mutation profiles in China.

DESIGN

Using MTBDRplus, drug susceptibility testing (DST) and DNA sequencing, 237 Mycobacterium tuberculosis strains were tested.

RESULTS

The sensitivity of MTBDRplus was 75.0% (126/168) for isoniazid (INH) resistant strains, and 93.5% (157/168) for rifampicin (RMP) resistant strains. It correlated well with sequencing, with 94.9% and 99.6% agreement for each strain category and 100% specificity for all categories. The two most common rpoB mutations were S531L (53.6%, 90/168) and D516G (17.3%, 29/168) in RMP-resistant strains. INH resistance was dominated by the katG 315 locus (S to T, N, R, I) mutation (73.7%, 124/168), and a rare katG mutation, S315N (6.5%, 11/168), not covered by MTBDRplus was identified. The mutation combination inhA-15/inhA-8 and katG315 (34 strains) was characteristically displayed in MDR-TB strains (23.5%), but not in INH-monoresistant strains.

CONCLUSIONS

Although Genotype MTBDRplus is a rapid and reliable molecular test for detecting MDR-TB, a significant proportion of strains in China contain a rare katG S315N mutation that would be missed by the assay. Further improvements may be achieved by incorporating this mutation into the assay to increase sensitivity in detecting INH resistance in China.