63 research outputs found
Effect of Comorbidities on HIV-1 Pathogenesis in Monocytic Cells
The advent of antiretroviral therapy (ART) has substantially increased the life span of people living with HIV-1 (PLWH). However, the presence of comorbid conditions such as high prevalence of drug abuse and coinfections have deteriorated the health outcomes in PLWH and progression of HIV-1 infection to AIDS. In this study, we will be focusing on the independent effect of two major comorbidities: cigarette smoking and human papilloma virus (HPV) coinfection on HIV-1 replication and pathogenesis in monocytic cells.
The prevalence of smoking is approximately 3-times higher in PLWH compared to the general population. Scientific evidences suggest that smoking aggravates HIV-1 pathogenesis and leads to decreased responses to ART. However, the exact mechanism by which smoking enhances HIV-1 replication is still not clear. The Kumar group has demonstrated the role of nicotine, at least in part, on HIV-1 replication in monocytic cells via cytochrome P450 (CYP)-mediated oxidative stress pathway. They have also shown the role of cigarette smoke condensate (CSC), which contains numerous organic compounds such as polyaryl hydrocarbons (PAHs), on cytotoxicity and HIV-1 replication in monocytic cells. Therefore, the goal in this study was to identify active ingredient of CSC, especially PAHs, which is responsible for cytotoxicity and HIV-1 replication in monocytic cells, and their underlying mechanism. PAHs such as benzo(a)pyrene (BaP), naphthalene (NPh), phenanthrene (Phe), benzo(a)antharacene (BeA), and benzo(b)fluoranthene (BeF) are known carcinogens present in cigarette smoke. As a first part of our study, we examined the relative effect of these constituents on the cytotoxicity of monocytic cells and the possible mechanism of PAH-mediated cytotoxicity. We examined the acute (6-24 hours) and chronic (7 days) effects of these PAHs on the expression of cytochromes P450 (CYPs), oxidative stress, and cytotoxicity. The treated cells were examined for mRNA and protein levels of CYPs (1A1 and 3A4) and antioxidants enzymes (AOEs) superoxide dismutase-1 (SOD1) and catalase. Further, we assessed the levels of reactive oxygen species (ROS), caspase-3 cleavage activity, and cell viability. We performed these experiments in U937 cell lines and/or primary monocytic cells. Of the five PAHs tested, after chronic treatment only BaP (100 nM) showed a significant increase in the expression of CYP1A1, AOEs (SOD1 and catalase), ROS generation, caspase-3 cleavage activity, and cytotoxicity. However, acute treatment with BaP showed only an increase in the mRNA expression of CYP1A1. These results suggested that of the five PAHs tested, BaP is the major contributor to the toxic effect of PAHs in monocytic cells, which is likely to occur through CYP and oxidative stress pathways.
Secondly, we investigated a molecular mechanism that would explain BaPinduced HIV-1 replication. We hypothesized that CYP-mediated BaP metabolism generates ROS, and the resultant oxidative stress aggravates HIV-1 replication. As expected, we observed ~4-fold increase in HIV-1 replication in differentiated U1 (HIV-1- infected U937) monocytic cell lines and human primary macrophages after chronic BaP exposure. We also observed ~30-fold increase in the expression of CYP1A1 at mRNA level, ~2-fold increase in its enzymatic activity, as well as, an elevated ROS level and cytotoxicity in U1 cells. The knock-down of the CYP1A1 gene using siRNA and treatment with selective CYP inhibitors and antioxidants significantly reduced HIV-1 replication. Further, we observed a nuclear translocation of NF-κB subunits (p50 and p65) after chronic BaP exposure, which was reduced by treatment with siRNA/inhibitors of CYP and antioxidants. Suppression of NF-κB pathway using specific NF-κB inhibitors also significantly reduced HIV-1 replication. Together, our results suggest that BaP enhances the HIV-1 replication in macrophages by CYP-mediated oxidative stress pathway via NF-κB signaling cascade.
Thirdly, we explored the underlying mechanism by which HPV increases HIV-1 pathogenesis. HPV infection is one of the major factors that contribute to a reduced suppression of the virus in HIV-1 patients. There is a high prevalence of comorbidity of HIV-1 and HPV (which leads to cervical cancer) among HIV-1-infected population. We proposed that exosomes secreted from HPV-infected cervical cancer cells exacerbate HIV-1 replication in HIV-1-infected macrophages. To test the hypothesis, we treated U1 cells (HIV-1-infected monocytic cell line) with the cell culture supernatant (CCS) obtained from caski cells (HPV-infected cervical cancer cells). We observed an ~2-fold increase in HIV-1 replication in the treated U1 cell. We also observed a significant increase in the expression of CYPs (CYP 1A1 and 2A6) at the mRNA level. However, we did not observe any significant change in the expression of CYPs as well as antioxidants enzymes (catalase, PRDX6) at the protein level. Furthermore, we isolated exosomes from the caski cell culture supernatant and observed the presence of CYPs (1A1, 2A6), SOD1 and HPV protein HPV16 E6 in caski exosomes. The exosomes derived from caski cells (CCS-Exo) significantly reduced cytotoxicity, while it increased HIV-1 replication in U1 cells. Treatment of antioxidant such as resveratrol, CYP1A1 inhibitor (ellipticine) and CYP2A6 inhibitor (Tryptamine) including chemodietary agents such as curcumin (20 μM) and curcubitacin-D (0.1 μM), significantly reduced the CCS and CCS-Exo mediated HIV-1 replication in U1 cells. These results suggest the role of specific CYP-induced oxidative stress pathway in HIV-1 replication. Altogether, we demonstrated that cervical cancer cells exacerbate HIV-1 replication in monocytic cells via transferring oxidative stress factors such as CYPs and HPV oncoproteins through exosomes. We also showed that the viral replication undergoes via a CYP-mediated oxidative stress pathway and it can be reduced by treatment of chemodietary agents like curcumin and Cucurbitacin-D. The present study therefore, illustrates that comorbidities such as smoking and HPV coinfection contribute to HIV-1 replication and pathogenesis in monocytic cells via a CYP-mediated oxidative stress pathway. The study also provides scientific rationale for the development of novel therapeutic treatment for PLWHs with these comorbidities by targeting CYP and specific oxidative stress pathway
Extracellular Vesicles from Human Papilloma Virus-Infected Cervical Cancer Cells Enhance HIV-1 Replication in Differentiated U1 Cell Line
In the current study, we hypothesized that extracellular vesicles (EVs) secreted from human papilloma virus (HPV)-infected cervical cancer cells exacerbate human immunodeficiency virus (HIV)-1 replication in differentiated U1 cell line through an oxidative stress pathway. To test the hypothesis, we treated an HIV-1-infected macrophage cell line (U1) with HPV-infected Caski cell culture supernatant (CCS). We observed a significant increase in HIV-1 replication, which was associated with an increase in the expression of cytochrome P450 (CYPs 1A1 and 2A6) in the CCS-treated U1 cells. Furthermore, we isolated EVs from CCS (CCS-EVs), which showed the presence of CYPs (1A1, 2A6), superoxide dismutase 1 (SOD1), and HPV oncoproteins HPV16 E6. CCS-EVs when exposed to the U1 cells also significantly increased HIV-1 replication. Treatment of antioxidant, CYP1A1 and CYP2A6 inhibitors, and chemodietary agents with antioxidant properties significantly reduced the CCS and CCS-EVs mediated HIV-1 replication in U1 cells. Altogether, we demonstrate that cervical cancer cells exacerbate HIV-1 replication in differentiated U1 cell line via transferring CYPs and HPV oncoproteins through EVs. We also show that the viral replication occurs via CYP and oxidative stress pathways, and the viral replication is also reduced by chemodietary agents. This study provides important information regarding biological interactions between HPV and HIV-1 via EVs leading to enhanced HIV-1 replication
Aboriginal and Torres Strait Islander health workers: the skills recognition and upskilling project
Introduction: Throughout 2014 and 2015 a series of three, two-week residential blocks were conducted by Tropical North Queensland TAFE in collaboration with James Cook University to deliver essential content to help with skills recognition and upskilling of Aboriginal and Torres Strait Islander Health Workers in Queensland. The project goal was to assist eligible Aboriginal and Torres Strait Islander Health Workers to qualify for a Certificate IV in Aboriginal and Torres Strait Islander Primary Health Care Practice and be able to apply for registration with the Australian Health Practitioner Regulation Agency (AHPRA).
Purpose: This presentation will share what was achieved throughout this project and some of the challenges faced by the educational institutions in delivering the program. Furthermore, challenges faced by students will also be explored, along with strategies that were implemented to help overcome them.
Issues for exploration or ideas for discussion:
i.Criteria used for student selection to program –how successful was it?
ii. The importance of clearly communicated training goals.
iii. Working collaboratively to provide successful cross institutional education.
Results: The first cohort of students were less satisfied with the training experience than
the second and third cohorts of students. The results also showed that that the third cohort had the most students to complete all five units of the training package.
Discussion: Reasons why the first cohort's experience was not as satisfying as the subsequent groups will be explored and discussed. Lesson learned and recommendations will be shared
Enhancing clinical education for Aboriginal and Torres Strait Islander health workers: a university/vocational education and training (VET) sector collaboration
Introduction: Throughout 2014 and 2015 a series of three, two-week residential blocks were conducted by TAFE North Cairns in collaboration with James Cook University to deliver upskilling training, including simulation education,
for Aboriginal and Torres Strait Islander health workers in north Queensland.
Aim of the project: The project goal was to assist eligible Aboriginal and Torres Strait Islander Health Workers to qualify for a Certificate IV in Aboriginal and Torres Strait Islander Primary Health Care Practice and be able to apply for registration with the Aboriginal and Torres Strait Islander Health Practice Board of Australia.
Methods used to bring about change:
Strategies developed for delivering quality clinical education in a collaborative environment include:
- Shared resources – simulation equipment, teaching staff (knowledge and expertise), lesson plans and other equipment and resources
- Regular meetings to explore innovative teaching strategies and enhance simulation opportunities
- A commitment to providing quality clinical education
Outcomes: As the partnership strengthened so did student satisfaction and learning outcomes/pass rates. Students consistently reported the simulation training was the highlight.
Conclusion: Lessons Learnt/Recommendations for wider application:
- Importance of promoting collaboration and cooperation between health and higher education providers: It is recommended for future training that time spent by higher education (University/VET sector) building relationships
with health industry is a solid investment in positive training outcomes and health industry (health worker and employer) satisfaction
- Language Literacy Numeracy (LLN) support needs: It is recommended that LLN assessment be conducted prior to students attending residential training in order for learning support staff to develop and implement individualised learning support plans
Games of Incomplete Information and Myopic Equilibria
A new concept of an equilibrium in games is introduced that solves an open
question posed by A. Neyman
Contributions of mean and shape of blood pressure distribution to worldwide trends and variations in raised blood pressure: A pooled analysis of 1018 population-based measurement studies with 88.6 million participants
© The Author(s) 2018. Background: Change in the prevalence of raised blood pressure could be due to both shifts in the entire distribution of blood pressure (representing the combined effects of public health interventions and secular trends) and changes in its high-blood-pressure tail (representing successful clinical interventions to control blood pressure in the hypertensive population). Our aim was to quantify the contributions of these two phenomena to the worldwide trends in the prevalence of raised blood pressure. Methods: We pooled 1018 population-based studies with blood pressure measurements on 88.6 million participants from 1985 to 2016. We first calculated mean systolic blood pressure (SBP), mean diastolic blood pressure (DBP) and prevalence of raised blood pressure by sex and 10-year age group from 20-29 years to 70-79 years in each study, taking into account complex survey design and survey sample weights, where relevant. We used a linear mixed effect model to quantify the association between (probittransformed) prevalence of raised blood pressure and age-group- and sex-specific mean blood pressure. We calculated the contributions of change in mean SBP and DBP, and of change in the prevalence-mean association, to the change in prevalence of raised blood pressure. Results: In 2005-16, at the same level of population mean SBP and DBP, men and women in South Asia and in Central Asia, the Middle East and North Africa would have the highest prevalence of raised blood pressure, and men and women in the highincome Asia Pacific and high-income Western regions would have the lowest. In most region-sex-age groups where the prevalence of raised blood pressure declined, one half or more of the decline was due to the decline in mean blood pressure. Where prevalence of raised blood pressure has increased, the change was entirely driven by increasing mean blood pressure, offset partly by the change in the prevalence-mean association. Conclusions: Change in mean blood pressure is the main driver of the worldwide change in the prevalence of raised blood pressure, but change in the high-blood-pressure tail of the distribution has also contributed to the change in prevalence, especially in older age groups
Global variation in diabetes diagnosis and prevalence based on fasting glucose and hemoglobin A1c
Fasting plasma glucose (FPG) and hemoglobin A1c (HbA1c) are both used to diagnose diabetes, but these measurements can identify different people as having diabetes. We used data from 117 population-based studies and quantified, in different world regions, the prevalence of diagnosed diabetes, and whether those who were previously undiagnosed and detected as having diabetes in survey screening, had elevated FPG, HbA1c or both. We developed prediction equations for estimating the probability that a person without previously diagnosed diabetes, and at a specific level of FPG, had elevated HbA1c, and vice versa. The age-standardized proportion of diabetes that was previously undiagnosed and detected in survey screening ranged from 30% in the high-income western region to 66% in south Asia. Among those with screen-detected diabetes with either test, the age-standardized proportion who had elevated levels of both FPG and HbA1c was 29-39% across regions; the remainder had discordant elevation of FPG or HbA1c. In most low- and middle-income regions, isolated elevated HbA1c was more common than isolated elevated FPG. In these regions, the use of FPG alone may delay diabetes diagnosis and underestimate diabetes prevalence. Our prediction equations help allocate finite resources for measuring HbA1c to reduce the global shortfall in diabetes diagnosis and surveillance
Repositioning of the global epicentre of non-optimal cholesterol
High blood cholesterol is typically considered a feature of wealthy western countries(1,2). However, dietary and behavioural determinants of blood cholesterol are changing rapidly throughout the world(3) and countries are using lipid-lowering medications at varying rates. These changes can have distinct effects on the levels of high-density lipoprotein (HDL) cholesterol and non-HDL cholesterol, which have different effects on human health(4,5). However, the trends of HDL and non-HDL cholesterol levels over time have not been previously reported in a global analysis. Here we pooled 1,127 population-based studies that measured blood lipids in 102.6 million individuals aged 18 years and older to estimate trends from 1980 to 2018 in mean total, non-HDL and HDL cholesterol levels for 200 countries. Globally, there was little change in total or non-HDL cholesterol from 1980 to 2018. This was a net effect of increases in low- and middle-income countries, especially in east and southeast Asia, and decreases in high-income western countries, especially those in northwestern Europe, and in central and eastern Europe. As a result, countries with the highest level of non-HDL cholesterol-which is a marker of cardiovascular riskchanged from those in western Europe such as Belgium, Finland, Greenland, Iceland, Norway, Sweden, Switzerland and Malta in 1980 to those in Asia and the Pacific, such as Tokelau, Malaysia, The Philippines and Thailand. In 2017, high non-HDL cholesterol was responsible for an estimated 3.9 million (95% credible interval 3.7 million-4.2 million) worldwide deaths, half of which occurred in east, southeast and south Asia. The global repositioning of lipid-related risk, with non-optimal cholesterol shifting from a distinct feature of high-income countries in northwestern Europe, north America and Australasia to one that affects countries in east and southeast Asia and Oceania should motivate the use of population-based policies and personal interventions to improve nutrition and enhance access to treatment throughout the world.Peer reviewe
Height and body-mass index trajectories of school-aged children and adolescents from 1985 to 2019 in 200 countries and territories: a pooled analysis of 2181 population-based studies with 65 million participants
Summary Background Comparable global data on health and nutrition of school-aged children and adolescents are scarce. We aimed to estimate age trajectories and time trends in mean height and mean body-mass index (BMI), which measures weight gain beyond what is expected from height gain, for school-aged children and adolescents. Methods For this pooled analysis, we used a database of cardiometabolic risk factors collated by the Non-Communicable Disease Risk Factor Collaboration. We applied a Bayesian hierarchical model to estimate trends from 1985 to 2019 in mean height and mean BMI in 1-year age groups for ages 5–19 years. The model allowed for non-linear changes over time in mean height and mean BMI and for non-linear changes with age of children and adolescents, including periods of rapid growth during adolescence. Findings We pooled data from 2181 population-based studies, with measurements of height and weight in 65 million participants in 200 countries and territories. In 2019, we estimated a difference of 20 cm or higher in mean height of 19-year-old adolescents between countries with the tallest populations (the Netherlands, Montenegro, Estonia, and Bosnia and Herzegovina for boys; and the Netherlands, Montenegro, Denmark, and Iceland for girls) and those with the shortest populations (Timor-Leste, Laos, Solomon Islands, and Papua New Guinea for boys; and Guatemala, Bangladesh, Nepal, and Timor-Leste for girls). In the same year, the difference between the highest mean BMI (in Pacific island countries, Kuwait, Bahrain, The Bahamas, Chile, the USA, and New Zealand for both boys and girls and in South Africa for girls) and lowest mean BMI (in India, Bangladesh, Timor-Leste, Ethiopia, and Chad for boys and girls; and in Japan and Romania for girls) was approximately 9–10 kg/m2. In some countries, children aged 5 years started with healthier height or BMI than the global median and, in some cases, as healthy as the best performing countries, but they became progressively less healthy compared with their comparators as they grew older by not growing as tall (eg, boys in Austria and Barbados, and girls in Belgium and Puerto Rico) or gaining too much weight for their height (eg, girls and boys in Kuwait, Bahrain, Fiji, Jamaica, and Mexico; and girls in South Africa and New Zealand). In other countries, growing children overtook the height of their comparators (eg, Latvia, Czech Republic, Morocco, and Iran) or curbed their weight gain (eg, Italy, France, and Croatia) in late childhood and adolescence. When changes in both height and BMI were considered, girls in South Korea, Vietnam, Saudi Arabia, Turkey, and some central Asian countries (eg, Armenia and Azerbaijan), and boys in central and western Europe (eg, Portugal, Denmark, Poland, and Montenegro) had the healthiest changes in anthropometric status over the past 3·5 decades because, compared with children and adolescents in other countries, they had a much larger gain in height than they did in BMI. The unhealthiest changes—gaining too little height, too much weight for their height compared with children in other countries, or both—occurred in many countries in sub-Saharan Africa, New Zealand, and the USA for boys and girls; in Malaysia and some Pacific island nations for boys; and in Mexico for girls. Interpretation The height and BMI trajectories over age and time of school-aged children and adolescents are highly variable across countries, which indicates heterogeneous nutritional quality and lifelong health advantages and risks
Worldwide trends in underweight and obesity from 1990 to 2022: a pooled analysis of 3663 population-representative studies with 222 million children, adolescents, and adults
Background Underweight and obesity are associated with adverse health outcomes throughout the life course. We
estimated the individual and combined prevalence of underweight or thinness and obesity, and their changes, from
1990 to 2022 for adults and school-aged children and adolescents in 200 countries and territories.
Methods We used data from 3663 population-based studies with 222 million participants that measured height and
weight in representative samples of the general population. We used a Bayesian hierarchical model to estimate
trends in the prevalence of different BMI categories, separately for adults (age ≥20 years) and school-aged children
and adolescents (age 5–19 years), from 1990 to 2022 for 200 countries and territories. For adults, we report the
individual and combined prevalence of underweight (BMI <18·5 kg/m2) and obesity (BMI ≥30 kg/m2). For schoolaged children and adolescents, we report thinness (BMI <2 SD below the median of the WHO growth reference)
and obesity (BMI >2 SD above the median).
Findings From 1990 to 2022, the combined prevalence of underweight and obesity in adults decreased in
11 countries (6%) for women and 17 (9%) for men with a posterior probability of at least 0·80 that the observed
changes were true decreases. The combined prevalence increased in 162 countries (81%) for women and
140 countries (70%) for men with a posterior probability of at least 0·80. In 2022, the combined prevalence of
underweight and obesity was highest in island nations in the Caribbean and Polynesia and Micronesia, and
countries in the Middle East and north Africa. Obesity prevalence was higher than underweight with posterior
probability of at least 0·80 in 177 countries (89%) for women and 145 (73%) for men in 2022, whereas the converse
was true in 16 countries (8%) for women, and 39 (20%) for men. From 1990 to 2022, the combined prevalence of
thinness and obesity decreased among girls in five countries (3%) and among boys in 15 countries (8%) with a
posterior probability of at least 0·80, and increased among girls in 140 countries (70%) and boys in 137 countries (69%)
with a posterior probability of at least 0·80. The countries with highest combined prevalence of thinness and
obesity in school-aged children and adolescents in 2022 were in Polynesia and Micronesia and the Caribbean for
both sexes, and Chile and Qatar for boys. Combined prevalence was also high in some countries in south Asia, such
as India and Pakistan, where thinness remained prevalent despite having declined. In 2022, obesity in school-aged
children and adolescents was more prevalent than thinness with a posterior probability of at least 0·80 among girls
in 133 countries (67%) and boys in 125 countries (63%), whereas the converse was true in 35 countries (18%) and
42 countries (21%), respectively. In almost all countries for both adults and school-aged children and adolescents,
the increases in double burden were driven by increases in obesity, and decreases in double burden by declining
underweight or thinness.
Interpretation The combined burden of underweight and obesity has increased in most countries, driven by an
increase in obesity, while underweight and thinness remain prevalent in south Asia and parts of Africa. A healthy
nutrition transition that enhances access to nutritious foods is needed to address the remaining burden of
underweight while curbing and reversing the increase in obesit
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