Role of ALS-associated OPTN-K489E mutation in neuronal cell-death regulation.

Optineurin (OPTN) gene is a marker of amyotrophic lateral sclerosis (ALS). However, the role of optineurin protein (OPTN) in ALS pathology is unclear, even though it is known to regulate autophagy, apoptosis, and other survival-death cellular processes. Genetic analysis of Indian ALS patients by our group ascertained a novel mutation K489E in the OPTN gene. To identify the molecular mechanism associated with OPTN and its mutation, we developed an in-vitro cell model using SH-SY5Y cells harbouring OPTN and OPTN-K489E mutation along with its control vector. Since we observed a significant decrease in cell viability in the mutant, we measured the expressions of genes and proteins mediating apoptosis, necroptosis, and autophagy, to establish the role of OPTN in cell death regulation. Our results show that OPTN-K489E mutation changes the relative gene expressions of miRNA-9, REST, CoREST and BDNF, and causes apoptosis. We also observed an up-regulation in the expressions of necroptosis mediated genes RIPK1, RIPK3, and MLKL and autophagy mediated genes TBK1, P62, and LC3II. The results of FACS analyses revealed that this mutation promotes apoptotic and necroptotic processes confirming the pathogenicity of OPTN-K489E.

Advances in bioreactor control for production of biotherapeutic products.

Advanced control strategies are well established in chemical, pharmaceutical, and food processing industries. Over the past decade, the application of these strategies is being explored for control of bioreactors for manufacturing of biotherapeutics. Most of the industrial bioreactor control strategies apply classical control techniques, with the control system designed for the facility at hand. However, with the recent progress in sensors, machinery, and industrial internet of things, and advancements in deeper understanding of the biological processes, coupled with the requirement of flexible production, the need to develop a robust and advanced process control system that can ease process intensification has emerged. This has further fuelled the development of advanced monitoring approaches, modeling techniques, process analytical technologies, and soft sensors. It is seen that proper application of these concepts can significantly improve bioreactor process performance, productivity, and reproducibility. This review is on the recent advancements in bioreactor control and its related aspects along with the associated challenges. This study also offers an insight into the future prospects for development of control strategies that can be designed for industrial-scale production of biotherapeutic products.

In vitro toxicity screening of amorphous silica nanoparticles using mitochondrial fraction exposure followed by MS-based proteomic analysis.

Silica nanoparticles (SiNPs) are used in consumer products, engineering and medical technologies. Attractive properties of SiNPs (e.g. size/surface-modification) enhance usage and thus the likelihood of environmental/human exposures. The assessment of health risks associated with exposures to SiNPs requires information on their relative potencies and toxicity mechanisms. In this work, phagocytic J774 cells were exposed to amorphous pristine (15, 30, 75 nm) and surface-modified (-NH2, -C3COOH, -C11COOH, -PEG) SiNP variants, and internalization was assessed by transmission electron microscopy (TEM), while cellular ATP was measured as a cytotoxicity endpoint. Furthermore, mitochondrial fractions from J774 cells were exposed to these SiNP variants (5, 15 µg mL-1), as well as two reference particles (SiNP 12 nm and TiO2), and proteomic changes were analyzed by mass spectrometry. Ingenuity Pathway Analysis was used to identify toxicity pathways. TEM analyses showed SiNP internalization and distribution along with some changes in mitochondrial structure. SiNP size- and surface-modification and chemical composition-related changes in mitochondrial proteins, including key proteins of the respiratory complex and oxidative stress, were evident based on high content mass spectrometry data. In addition, the dose-related decrease in cellular ATP levels in SiNP-exposed cells was consistent with related mitochondrial protein profiles. These findings suggest that physicochemical properties can be determinants of SiNP exposure-related mitochondrial effects, and mitochondrial exposures combined with proteomic analysis can be valuable as a new approach methodology in the toxicity screening of SiNPs for risk assessment, with added insight into related toxicity mechanisms.

Acellular oxidative potential assay for screening of amorphous silica nanoparticles.

Silica nanoparticles (SiNPs) are used in a wide range of consumer products, engineering and medical applications, with likelihood of human exposure and potential health concerns. It is essential to generate toxicity information on SiNP forms and associated physicochemical determinants to conduct risk assessment on these new materials. To address this knowledge gap, we screened a panel of custom synthesized, well-characterized amorphous SiNPs pristine and surface-modified (-C3-COOH, -C11-COOH, -NH2, -PEG) of 5 different sizes: (15, 30, 50, 75, 100 nm) for their oxidative potential using an acellular assay. The assay is based on oxidation of dithiothreitol (DTT) by reactive oxygen species and can serve as a surrogate test for oxidative stress. These materials were characterized for size distribution, aggregation, crystallinity, surface area, surface modification, surface charge and metal content. Tests for association between oxidative potential of SiNPs and their physicochemical properties were carried out using analysis of variance and correlation analyses. These test results suggest that the size of amorphous SiNPs influenced their oxidative potential irrespective of the surface modification, with 15 nm exhibiting relatively higher oxidative potential compared to the other sizes. Furthermore, SiNP surface area, surface modification and agglomeration in solution also appeared to affect oxidative potential of these SiNPs. These findings indicate that physicochemical properties are critical in influencing the oxidative behaviour of amorphous SiNPs, with potential to trigger cellular oxidative stress and thus toxicity, when exposed. This information advances our understanding of potential toxicities of these amorphous SiNPs and supports risk assessment efforts and the design of safer forms of silica nanomaterials.

Identification and characterization of novel and rare susceptible variants in Indian amyotrophic lateral sclerosis patients.

Rare missense variants play a crucial role in amyotrophic lateral sclerosis (ALS) pathophysiology. We report rare/novel missense variants from 154 Indian ALS patients, identified through targeted sequencing of 25 ALS-associated genes. As pathogenic variants could explain only a small percentage of ALS pathophysiology in our cohort, we investigated the frequency of tolerated and benign novel/rare variants, which could be potentially ALS susceptible. These variants were identified in 5.36% (8/149) of sporadic ALS (sALS) cases; with one novel variant each in ERBB4, SETX, DCTN1, and MATR3; four rare variants, one each in PON2 and ANG and two different rare variants in SETX. Identified variants were either absent or present at extremely rare frequencies (MAF < 0.01) in large population databases and were absent in 50 healthy controls sequenced through Sanger method. Furthermore, an oligogenic basis of ALS was observed in three sALS, with co-occurrence of intermediate-length repeat expansions in ATXN2 and a rare/novel variant in DCTN1 and SETX genes. Additionally, molecular dynamics and biochemical functional analysis of an angiogenin variant (R21G) identified from our cohort demonstrated loss of ribonucleolytic and nuclear translocation activities. Our findings suggest that rare variants could be potentially pathogenic and functional studies are warranted to decisively establish the pathogenic mechanisms associated with them.

Rare Angiogenin and Ribonuclease 4 variants associated with amyotrophic lateral sclerosis exhibit loss-of-function: a comprehensive in silico study.

Amyotrophic Lateral Sclerosis (ALS), a debilitating neurodegenerative disorder is related to mutations in a number of genes, and certain genes of the Ribonuclease (RNASE) superfamily trigger ALS more frequently. Even though missense mutations in Angiogenin (ANG) and Ribonuclease 4 (RNASE4) have been previously shown to cause ALS through loss-of-function mechanisms, understanding the role of rare variants with a plausible explanation of their functional loss mechanisms is an important mission. The study aims to understand if any of the rare ANG and RNASE4 variants catalogued in Project MinE consortium caused ALS due to loss of ribonucleolytic or nuclear translocation or both these activities. Several in silico analyses in combination with extensive molecular dynamics (MD) simulations were performed on wild-type ANG and RNASE4, along with six rare variants (T11S-ANG, R122H-ANG, D2E-RNASE4, N26K-RNASE4, T79A-RNASE4 and G119S-RNASE4) to study the structural and dynamic changes in the catalytic triad and nuclear localization signal residues responsible for ribonucleolytic and nuclear translocation activities respectively. Our comprehensive analyses comprising 1.2 µs simulations with a focus on physicochemical, structural and dynamic properties reveal that T11S-ANG, N26K-RNASE4 and T79A-RNASE4 variants would result in loss of ribonucleolytic activity due to conformational switching of catalytic His114 and His116 respectively but none of the variants would lose their nuclear translocation activity. Our study not only highlights the importance of rare variants but also demonstrates that elucidating the structure-function relationship of mutant effectors is crucial to gain insights into ALS pathophysiology and in developing effective therapeutics.

Calcium role in human carcinogenesis: a comprehensive analysis and critical review of literature.

The central role played by calcium ion in biological systems has generated an interest for its potential implication in human malignancies. Thus, lines of research, on possible association of calcium metabolism regulation with tumorigenesis, implying disruptions and/or alterations of known molecular pathways, have been extensively researched in the recent decades. This paper is a critical synthesis of these findings, based on a functional approach of the calcium signaling toolkit. It provides strong support that this ubiquitous divalent cation is involved in cancer initiation, promotion, and progression. Different pathways have been outlined, involving equally different molecular and cellular structures. However, if the association between calcium and cancer can be described as constant, it is not always linear. We have identified several influencing factors among which the most relevant are (i) the changes in local or tissular concentrations of free calcium and (ii) the histological and physiological types of tissue involved. Such versatility at the molecular level may probably account for the conflicting findings reported by the epidemiological literature on calcium dietary intake and the risk to develop certain cancers such as the prostatic or mammary neoplasms. However, it also fuels the hypothesis that behind each cancer, a specific calcium pathway can be evidenced. Identifying such molecular interactions is probably a promising approach for further understanding and treatment options for the disease.

Ser422 phosphorylation blocks human Tau cleavage by caspase-3: Biochemical implications to Alzheimer's Disease.

Proteolytic truncation of microtubule associated human (h) Tau protein by caspase-3 at the carboxy (C) terminus has been linked to the pathogenesis of Alzheimer's Disease (AD). This cleavage likely occurs between Asp421↓Ser422 leading to the formation of 421-mer truncated Tau protein which has been found to be present as aggregate in high level after phosphorylation in mortal AD brain tissue compared to normal. At least 50 phosphorylation sites involving Ser, Thr and Tyr residues have been identified or proposed in hTau and a selected number of them have been implicated in hTau aggregation following latter's proteolytic truncation. Interestingly, it is further noted that Ser422 residue present in the P1' position of hTau caspase-3 cleavage region is a potential phosphorylation site. So we became interested to examine in vitro the effect of phospho-Ser422 residue on hTau cleavage by caspase-3 which is a crucial upstream event associated with hTau self-assembly leading to AD pathogenesis. The goal of this project is to study in vitro the caspase-3 cleavage site of hTau protein and to examine the kinetics of this cleavage following Ser422 phosphorylation and treatment with caspase-3 inhibitors. This is achieved by designing peptides from the sequence of hTau protein containing the proposed caspase-3 cleavage region. Peptides were designed from 441-mer major human Tau protein sequence that encompasses the proposed caspase-3 cleavage site [Asp421↓Ser422]. Corresponding phospho-, dextro-Ser422 and dextro-Asp421 analogs were also designed. Peptides were synthesized by solid phase chemistry, purified and fully characterized by mass spectrometry. These were then incubated with recombinant caspase-3 enzyme under identical condition for digestion and analyzed for cleavage by mass spectrometry and RP-HPLC chromatograms. Our results indicated that while the control peptide is efficiently cleaved by caspase-3 at Asp421↓Ser422 site producing the expected N- and C-terminal fragment peptides, the corresponding phospho-Ser422 peptide remained completely resistant to the cleavage. Substitution of Asp421 by its dextro isoform also blocks peptide cleavage by caspase-3. However substitution of Ser422 by its dextro isoform in the peptide did not affect the cleavage significantly. The above results were further confirmed by caspase-3 digestion experiment in the presence of varying amounts of caspase-3 inhibitor (Ac-DQVD-aldehyde) which was found to block this cleavage in a highly effective manner. Our results highlighted the crucial significance of Ser422 phosphorylation and suggest that the kinase associated with this Ser-phosphorylation may protect Tau from aggregation. Thus specific promoters/activators of this kinase may find useful therapeutic benefits in arresting Tau truncation by caspase-3 and the progression of AD. In addition our data demonstrated that Tau-peptides where Ser422 or Asp421 are substituted by their respective dextro isomers, exhibit different cleavage kinetics by caspase-3 and this may have important implications in therapeutic intervention of Tau aggregation and associated AD.

The VP4 peptide of hepatitis A virus ruptures membranes through formation of discrete pores.

UNLABELLED: Membrane-active peptides, components of capsid structural proteins, assist viruses in overcoming the host membrane barrier in the initial stages of infection. Several such peptides have been identified, and their roles in membrane fusion or disruption have been characterized through biophysical studies. In several members of the Picornaviridae family, the role of the VP4 structural peptide in cellular-membrane penetration is well established. However, there is not much information on the membrane-penetrating capsid components of hepatitis A virus (HAV), an unusual member of this family. The VP4 peptide of HAV differs from its analogues in other picornaviruses in being significantly shorter in length and in lacking a signal for myristoylation, thought to be a critical requisite for VP4-mediated membrane penetration. Here we report, for the first time, that the atypical VP4 in HAV contains significant membrane-penetrating activity. Using a combination of biophysical assays and molecular dynamics simulation studies, we show that VP4 integrates into membrane vesicles through its N-terminal region to finally form discrete pores of 5- to 9-nm diameter, which induces leakage in the vesicles without altering their overall size or shape. We further demonstrate that the membrane activity of VP4 is specific toward vesicles mimicking the lipid content of late endosomes at acidic pH. Taken together, our data indicate that VP4 might be essential for the penetration of host endosomal membranes and release of the viral genome during HAV entry. IMPORTANCE: Hepatitis A virus causes acute hepatitis in humans through the fecal-oral route and is particularly prevalent in underdeveloped regions with poor hygienic conditions. Although a vaccine for HAV exists, its high cost makes it unsuitable for universal application in developing countries. Studies on host-virus interaction for HAV have been hampered due to a lack of starting material, since the virus is extremely slow growing in culture. Among the unknown aspects of the HAV life cycle is its manner of host membrane penetration, which is one of the most important initial steps in viral infection. Here, we present data to suggest that a small peptide, VP4, a component of the HAV structural polyprotein, might be essential in helping the viral genome cross cell membranes during entry. It is hoped that this work might help in elucidating the manner of initial host cell interaction by HAV.

CpG dinucleotide frequencies reveal the role of host methylation capabilities in parvovirus evolution.

Parvoviruses are rapidly evolving viruses that infect a wide range of hosts, including vertebrates and invertebrates. Extensive methylation of the parvovirus genome has been recently demonstrated. A global pattern of methylation of CpG dinucleotides is seen in vertebrate genomes, compared to "fractional" methylation patterns in invertebrate genomes. It remains unknown if the loss of CpG dinucleotides occurs in all viruses of a given DNA virus family that infect host species spanning across vertebrates and invertebrates. We investigated the link between the extent of CpG dinucleotide depletion among autonomous parvoviruses and the evolutionary lineage of the infected host. We demonstrate major differences in the relative abundance of CpG dinucleotides among autonomous parvoviruses which share similar genome organization and common ancestry, depending on the infected host species. Parvoviruses infecting vertebrate hosts had significantly lower relative abundance of CpG dinucleotides than parvoviruses infecting invertebrate hosts. The strong correlation of CpG dinucleotide depletion with the gain in TpG/CpA dinucleotides and the loss of TpA dinucleotides among parvoviruses suggests a major role for CpG methylation in the evolution of parvoviruses. Our data present evidence that links the relative abundance of CpG dinucleotides in parvoviruses to the methylation capabilities of the infected host. In sum, our findings support a novel perspective of host-driven evolution among autonomous parvoviruses.

Silk screen based dual spin-filter module for perfusion culture of adherent and non-adherent mammalian cells.

Spin-filters have been primarily used for producing therapeutic proteins from mammalian cells. However, disposability and/or high filter clogging of the existing spin-filter systems affect the process economy and productivity. Hence, to address these drawbacks a reusable dual spin-filter module for perfusion culture of adherent and non-adherent mammalian cells was designed. Two non-woven Bombyx mori silk layers were used as filter screen; the outer layer was conducive to cell attachment whilst the inner was non-conducive. Adherent cells can be cultured either in suspended mode using its inner single module or as monolayer of cells using its dual concentric module. We achieved 30 % higher urokinase productivity as compared to the stainless-steel spin-filter during perfusion experiments of adherent human kidney cells in suspended mode. This was due to the hydrophobic and negatively-charged silk screen that allows clog-free perfusion culture for prolonged periods.

Aggregation of E121K mutant D-amino acid oxidase and ubiquitination-mediated autophagy mechanisms leading to amyotrophic lateral sclerosis.

Amyotrophic Lateral Sclerosis (ALS) is a terminal adult-onset neuromuscular disorder. Our group has been studying this illness and previously reported novel mutations and rare mutations in a study using next-generation sequencing of DNA samples from Indian ALS patients. In this paper, we focus on the E121K mutation in the DAO gene to understand how it leads to ALS. Our experiments in SH-SY5Y cells indicate that the E121K mutation results in the accumulation of mutant protein aggregates, a change in cell morphology, and the death of neuronal cells. These protein aggregates get ubiquitinated and cause an imbalance in autophagy regulation. We observed an increase in the cellular concentrations of p62, OPTN, and LC3II. Through confocal microscopy studies, we show that the binding of p62 with ubiquitinated aggregates and its recruitment to LC3II mediates autophagosome generation. These relative changes in the key partners in autophagy increase cell death in cells harboring the E121K mutation and is a probable mechanism leading to ALS.

Structural and mechanistic insights into ALS patient derived mutations in D-amino acid oxidase.

The D-amino acid oxidase protein modulates neurotransmission by controlling the levels of D-serine, a co-agonist of N-methyl-D-aspartate receptors. Mutations in the DAO gene have been associated with ALS, with some studies reporting pathogenic mechanisms of the R199W mutation. We have characterized two novel mutations R38H and Q201R found in ALS patients and report certain novel findings related to the R199W mutation. We report the first instance of crystal structure analysis of a patient-derived mutant of DAO, R38H, solved at 2.10 Å. The structure revealed significant perturbations and altered binding with the cofactor (FAD) and the inhibitor benzoate, supported by biochemical assays. Q201R-DAO also exhibited significantly lower ligand binding efficiency. Furthermore, kinetic analysis across all variants revealed reduced oxidase activity and substrate binding. Notably, R38H-DAO exhibited near-WT activity only at high substrate concentrations, while R199W-DAO and Q201R-DAO displayed drastic activity reduction. Additionally, structural perturbations were inferred for R199W-DAO and Q201R-DAO, evident by the higher oligomeric state in the holoenzyme form. We also observed thermal instability in case of R199W-DAO mutant. We hypothesize that the mutant enzymes may be rendered non-functional in a cellular context, potentially leading to NMDAR-associated excitotoxicity. The study provides novel insights into structural and functional aspects of DAO mutations in ALS.

NeuroDNet - an open source platform for constructing and analyzing neurodegenerative disease networks.

BACKGROUND: Genetic networks control cellular functions. Aberrations in normal cellular function are caused by mutations in genes that disrupt the fine tuning of genetic networks and cause disease or disorder. However, the large number of signalling molecules, genes and proteins that constitute such networks, and the consequent complexity of interactions, has restrained progress in research elucidating disease mechanisms. Hence, carrying out a systematic analysis of how diseases alter the character of these networks is important. We illustrate this through our work on neurodegenerative disease networks. We created a database, NeuroDNet, which brings together relevant information about signalling molecules, genes and proteins, and their interactions, for constructing neurodegenerative disease networks. DESCRIPTION: NeuroDNet is a database with interactive tools that enables the creation of interaction networks for twelve neurodegenerative diseases under one portal for interrogation and analyses. It is the first of its kind, which enables the construction and analysis of neurodegenerative diseases through protein interaction networks, regulatory networks and Boolean networks. The database has a three-tier architecture - foundation, function and interface. The foundation tier contains the human genome data with 23857 protein-coding genes linked to more than 300 genes reported in clinical studies of neurodegenerative diseases. The database architecture was designed to retrieve neurodegenerative disease information seamlessly through the interface tier using specific functional information. Features of this database enable users to extract, analyze and display information related to a disease in many different ways. CONCLUSIONS: The application of NeuroDNet was illustrated using three case studies. Through these case studies, the construction and analyses of a PPI network for angiogenin protein in amyotrophic lateral sclerosis, a signal-gene-protein interaction network for presenilin protein in Alzheimer's disease and a Boolean network for a mammalian cell cycle was demonstrated. NeuroDNet is accessible at http://bioschool.iitd.ac.in/NeuroDNet/.

Characterization of E121K mutation of D-amino acid oxidase - Insights into mechanisms leading to amyotrophic lateral sclerosis.

D-amino acid oxidase (DAO) maintains the intracellular d-serine level which modulates the activity of the N-methyl-d-aspartate receptor and its dysfunction has been linked to several neurodegenerative disorders. In targeted next-generation sequencing study by our group, E121K mutation in DAO was associated with amyotrophic lateral sclerosis (ALS) in patients from India. However, variations in molecular mechanisms caused by this mutation which leads to ALS have not been studied. Hence, we carried out comparative biophysical characterization and assay studies of the wildtype- and mutant E121K-DAO. We observed that the purified E121K-DAO was inactive and exhibited a lower affinity for the FAD cofactor and benzoate inhibitor. Structural studies revealed that the E121K mutant has higher beta-sheet content, melting temperature, and oligomeric states compared to the wildtype. Kinetic study of aggregation of the variants using thioflavin-T confirmed that the E121K-DAO was more prone to aggregation. Microscopic visualization showed that the aggregation proceeds through an intermediate step involving the formation of fibrillar structures in the E121K mutant. Our results give insights into the underlying mechanisms leading to ALS pathogenesis.

Barriers and facilitators to ART adherence among ART non-adherence people living with HIV in Cameroon: A qualitative phenomenological study.

BACKGROUND: Antiretroviral therapy (ART) needs to be taken for life with near perfect levels of adherence for it to be effective. Nonetheless, ART non-adherence is still observed in sub-Saharan African (SSA) countries such as Cameroon. The objective of this study was to assess the factors influencing non-adherence and or adherence among people living with HIV (PLWH) who have experienced non-adherence to ART in Cameroon. METHODS: A descriptive qualitative study of PLWH who have experienced non-adherence with ART in Cameroon was conducted. Data were collected using in-depth interviews. Collected data were analyzed using the NVIVO 12 software. RESULTS: In total, 43 participants participated in this study. The Southwest and Littoral regions each contributed 15 (34.88%) of participants, participants' mean age was 37.1 years (SD: 9.81) and majority 34 (82.93%) were females. ART adherence barriers include those related to patient (forgetfulness, business with other things, unwillingness to swallow drugs daily), medication (side effects), health service (arrogance of caregivers, occasional drug shortages at treatment centre, poor counseling of patient), stigma (fear of status disclosure), use of alternative treatment (traditional medicine, prayers and deliverance), resource limitation (limited food, limited finances), environmental/social (limited or no home support), and political instability (disruption of free circulation by ghost towns, roadblocks and gunshots in some regions). ART adherence facilitators include social support (family and peer support), aligning treatment with patient's daily routines (align ART with schedule of family members), use of reminders (phone alarm, sound of church bell), health sector/caregiver support (messages to patient, financial support, proper counseling), and patient's awareness of HIV status/ART knowledge (awareness of HIV positive status, Knowledge of ART benefits). CONCLUSION: ART adherence barriers in Cameroon include those related to patient, medication, health service, stigma, use of alternative treatment, resource limitation, environmental/social, and political instability. ART adherence facilitators include social support, aligning treatment with patient's daily routines, use of reminders, health sector/caregiver support, and patient's awareness of HIV status/ART knowledge. Given these barriers and facilitators, continuous information provision and consistent support both from patients' families and caregivers are needed to improve adherence among patients. Further studies including many regions and larger samples using both in-depth and focused group discussions as well as quantitative approaches are required to uncover the burden related to ART non-adherence.

Prevalence and factors associated with HIV treatment non-adherence among people living with HIV in three regions of Cameroon: A cross-sectional study.

BACKGROUND: In Cameroon, HIV care decentralization is enforced as a national policy, but follow-up of people living with HIV (PLWH) is provider-driven, with little patient education and limited patient participation in clinical surveillance. These types of services can result in low antiretroviral therapy (ART) adherence. The objective of this study was to assess the prevalence and predictors of ART non-adherence among PLWH in Cameroon. METHODS: A cross-sectional descriptive study of PLWH in HIV treatment centres in Cameroon was conducted. Only PLWH, receiving treatment in a treatment centre within the country, who had been on treatment for at least six months and who were at least 21 years old were included in the study. Individuals were interviewed about their demographics and ART experiences. Data were collected using a structured interviewer-administered questionnaire and analyzed using STATA version 14. RESULTS: A total of 451 participants participated in this study, 33.48% were from the country's Southwest region. Their mean age was 43.42 years (SD: 10.42), majority (68.89%) were females. Overall proportion of ART non-adherence among participants was 37.78%, 35.88% missed taking ART twice in the last month. Reasons for missing ART include forgetfulness, business and traveling without drugs. Over half of participants (54.67%) know ART is life-long, 53.88% have missed ART service appointments, 7.32% disbelieve in ART benefits, 28.60% think taking ART gives unwanted HIV Status reminder and 2.00% experienced discrimination seeking ART services. In the multivariate analysis, odds of ART non-adherence in participants aged 41 and above was 0.35 times (95%CI: 0.14, 0.85) that in participants aged 21-30 years, odds of ART non-adherence comparing participants who attained only primary education to those who attained higher than secondary education was 0.57 times (95%CI: 0.33, 0.97) and the odds of ART non-adherence in participants who are nonalcohol consumers was 0.62 times (95%CI: 0.39, 0.98) that in alcohol consumers. CONCLUSION: High proportion of participants are ART non-adherent, and the factors significantly associated with ART non-adherence include age, education and alcohol consumption. However, some reasons for missing ART are masked in participants' limited knowledge in taking ART, disbelief in ART benefits, feelings that ART gives unwanted HIV status reminder and experiencing discrimination when seeking ART services. These underscores need to improve staff (health personnel) attitudes, staff-patient-communication, and proper ART prior initiation counselling of patients. Future studies need to focus on assessing long-term ART non-adherence trends and predictors using larger samples in many treatment centres and regions.

Barriers and facilitators for interventions to improve ART adherence in Sub-Saharan African countries: A systematic review and meta-analysis.

BACKGROUND: The HIV/AIDS pandemic remains a significant public health issue, with sub-Saharan Africa (SSA) at its epicentre. Although antiretroviral therapy (ART) has been introduced to decrease new infections and deaths, SSA reports the highest incidence of HIV/AIDS, constituting two-thirds of the global new infections. This review aimed to elucidate the predominant barriers and facilitators influencing ART adherence and to identify effective strategies to enhance ART adherence across SSA. METHODS: A comprehensive review was conducted on studies examining barriers to ART adherence and interventions to boost adherence among HIV-positive adults aged 15 and above in SSA, published from January 2010 onwards. The research utilized databases like Medline Ovid, CINAHL, Embase, and Scopus. Included were experimental and quasi-experimental studies, randomized and non-randomized controlled trials, comparative before and after studies, and observational studies such as cross-sectional, cohort, prospective and retrospective studies. Two independent reviewers screened the articles, extracted pertinent data, and evaluated the studies' methodological integrity using Joanna Briggs Institute's standardized appraisal tools. The compiled data underwent both meta-analysis and narrative synthesis. RESULTS: From an initial pool of 12,538 papers, 45 were selected (30 for narrative synthesis and 15 for meta-analysis). The identified barriers and facilitators to ART adherence were categorized into seven principal factors: patient-related, health system-related, medication-related, stigma, poor mental health, socioeconomic and socio-cultural-related factors. Noteworthy interventions enhancing ART adherence encompassed counselling, incentives, mobile phone short message service (SMS), peer delivered behavioural intervention, community ART delivery intervention, electronic adherence service monitoring device, lay health worker lead group intervention and food assistance. The meta-analysis revealed a statistically significant difference in ART adherence between the intervention and control groups (pooled OR = 1.56, 95%CI:1.35-1.80, p = <0.01), with evidence of low none statistically significant heterogeneity between studies (I2 = 0%, p = 0.49). CONCLUSION: ART adherence in SSA is influenced by seven key factors. Multiple interventions, either standalone or combined, have shown effectiveness in enhancing ART adherence. To optimize ART's impact and mitigate HIV's prevalence in SSA, stakeholders must consider these barriers, facilitators, and interventions when formulating policies or treatment modalities. For sustained positive ART outcomes, future research should target specific underrepresented groups like HIV-infected children, adolescents, and pregnant women in SSA to further delve into the barriers, facilitators and interventions promoting ART adherence.

Residents' perception and worldview about radon control policy in Canada: A pro-equity social justice lens.

Radon is a potent indoor air pollutant, especially in radon prone areas and in countries with long winters. As the second top lung carcinogen, radon is disproportionately affecting certain population subgroups. While many provinces have taken sporadic actions, the equity issue has remained unaddressed across all policy measures. Attempts to enforce radon guidelines and enact building regulations without considering residents' views have proved ineffective. Research linking residents' radon risk perception and worldviews regarding radon control policy is lacking in Canada. We applied mixed (quantitative and qualitative) methods in a pro-equity social justice lens to examine the variations in residents' risk perception, access to risk communication messages, and worldviews about risk management across the sociodemographic strata. Triangulation of the quantitative and qualitative findings strengthened the evidence base to identify challenges and potential solutions in addressing the health risk through upstream policy actions. Enacting radon control policy requires actions from all levels of governments and relevant stakeholders to ensure equal opportunities for all residents to take the preventive and adaptive measures. Small sample size limited the scope of findings for generalization. Future studies can examine the differential impacts of radon health risk as are determined by various sociodemographic variables in a representative national cohort.

Adherence barriers and interventions to improve ART adherence in Sub-Saharan African countries: A systematic review protocol.

BACKGROUND: The HIV/AIDS pandemic continues to be a major public health concern, particularly in Sub-Saharan Africa (SSA). Despite efforts to reduce new infections and deaths with the use of antiretroviral therapy (ART), SSA countries continue to bear the heaviest burden of HIV/AIDS globally, accounting for two-thirds of global new infections. The goal of this review is to identify common barriers to ART adherence as well as common effective interventions that can be implemented across SSA countries to improve ART adherence. METHODS: A systematic review of published studies on adult HIV-positive patients aged 15 or above, that have assessed the barriers to ART adherence and interventions improving patients' adherence to ART in SSA countries shall be conducted. We will conduct electronic searches for articles that have been published starting from January 2010 onwards. The databases that shall be searched will include Medline Ovid, CINAHL, Embase, and Scopus. The review will include experimental and quasi-experimental studies such as randomized and non-randomized controlled trials as well as comparative before and after studies, and observational studies-cross-sectional studies, cohort studies, prospective and retrospective studies. Two independent reviewers will screen all identified studies, extract data and appraise the methodological quality of the studies using standard critical appraisal tools from the Joanna Briggs Institute. The extracted data will be subjected to a meta-analysis and narrative synthesis. DISCUSSION: This review will synthesize existing evidence on ART adherence barriers and strategies for improving patient adherence to ART in SSA countries. It will identify common barriers to adherence and common interventions proven to improve adherence across SSA. We anticipate that the findings of this review will provide information policy makers and stakeholders involved in the fight against HIV, will find useful in deriving better ways of not only retaining patients on treatment but having them adhere to their treatment. REVIEW REGISTRATION: This protocol has been registered with the International Prospective Register of Systematic Reviews (PROSPERO); registration number CRD42021262256.