Toxicity assessment of CeO₂ and CuO nanoparticles at the air-liquid interface using bioinspired condensational particle growth

CeO2 and CuO nanoparticles (NPs) are used as additives in petrodiesel to enhance engine performance leading to reduced diesel combustion emissions. Despite their benefits, the additive application poses human health concerns by releasing inhalable NPs into the ambient air. In this study, a bioinspired lung cell exposure system, Dosimetric Aerosol in Vitro Inhalation Device (DAVID), was employed for evaluating the toxicity of aerosolized CeO2 and CuO NPs with a short duration of exposure (≤10 min vs. hours in other systems) and without exerting toxicity from non-NP factors. Human epithelial A549 lung cells were cultured and maintained within DAVID at the air-liquid interface (ALI), onto which aerosolized NPs were deposited, and experiments in submerged cells were used for comparison. Exposure of the cells to the CeO2 NPs did not result in detectable IL-8 release, nor did it produce a significant reduction in cell viability based on lactate dehydrogenase (LDH) assay, with a marginal decrease (10%) at the dose of 388 μg/cm2 (273 cm2/cm2). In contrast, exposure to CuO NPs resulted in a concentration dependent reduction in LDH release based on LDH leakage, with 38% reduction in viability at the highest dose of 52 μg/cm2 (28.3 cm2/cm2). Cells exposed to CuO NPs resulted in a dose dependent cellular membrane toxicity and expressed IL-8 secretion at a global dose five times lower than cells exposed under submerged conditions. However, when comparing the ALI results at the local cellular dose of CuO NPs to the submerged results, the IL-8 secretion was similar. In this study, we demonstrated DAVID as a new exposure tool that helps evaluate aerosol toxicity in simulated lung environment. Our results also highlight the necessity in choosing the right assay endpoints for the given exposure scenario, e.g., LDH for ALI and Deep Blue for submerged conditions for cell viability.

The relationship between long-term blood pressure variability and cortical thickness in older adults

High blood pressure variability (BPV) is a risk factor for cognitive decline and dementia, but its association with cortical thickness is not well understood. Here we use a topographical approach, to assess links between long-term BPV and cortical thickness in 478 (54% men at baseline) community dwelling older adults (70-88 years) from the ASPirin in Reducing Events in the Elderly NEURO sub-study. BPV was measured as average real variability, based on annual visits across three years. Higher diastolic BPV was significantly associated with reduced cortical thickness in multiple areas, including temporal (banks of the superior temporal sulcus), parietal (supramarginal gyrus, post-central gyrus), and posterior frontal areas (pre-central gyrus, caudal middle frontal gyrus), while controlling for mean BP. Higher diastolic BPV was associated with faster progression of cortical thinning across the three years. Diastolic BPV is an important predictor of cortical thickness, and trajectory of cortical thickness, independent of mean blood pressure. This finding suggests an important biological link in the relationship between BPV and cognitive decline in older age.

Trajectories of body mass index from early adulthood to late midlife and incidence of total knee arthroplasty for osteoarthritis: findings from a prospective cohort study

OBJECTIVE

To examine the association between body mass index (BMI) trajectories from early adulthood to late midlife and risk of total knee arthroplasty (TKA) for osteoarthritis.

METHODS

24,368 participants from the Melbourne Collaborative Cohort Study with weight collected during 1990-1994, 1995-1998, and 2003-2007, recalled weight at age 18-21 years, and height measured during 1990-1994 were included. Incident TKA from 2003 to 2007 to December 2018 was determined by linking cohort records to the National Joint Replacement Registry.

RESULTS

Using group-based trajectory modelling, six distinct trajectories (TR) of BMI from early adulthood (age 18-21 years) to late midlife (approximately 62 years) were identified: lower normal to normal BMI (TR1; 19.7% population), normal BMI to borderline overweight (TR2; 36.7%), normal BMI to overweight (TR3; 26.8%), overweight to borderline obese (TR4; 3.5%), normal BMI to class 1 obesity (TR5; 10.1%), overweight to class 2 obesity (TR6; 3.2%). Over 12.4 years, 1,328 (5.4%) had TKA. The hazard ratios for TKA increased in all TR compared to TR1 [from TR2: 2.03 (95% CI 1.64-2.52) to TR6: 8.59 (6.44-11.46)]. 28.4% of TKA could be prevented if individuals followed the trajectory one lower, an average weight reduction of 8-12 kg from early adulthood to late midlife, saving $AUS 373 million/year. Most reduction would occur in TR2 (population attributable fraction 37.9%, 95% CI 26.7-47.3%) and TR3 (26.8%, 20.0-31.2%).

CONCLUSIONS

Prevention of weight gain from young adulthood to late midlife in order to reduce overweight/obesity has the potential to significantly reduce the cost and burden of TKA.

Association between weight gain and knee osteoarthritis: a systematic review

OBJECTIVE

Although weight loss is recommended to manage knee osteoarthritis (KOA), adults tend to gain weight with age which may affect KOA symptoms and progression. We conducted a systematic review and data synthesis to investigate the association between weight gain and KOA, defined by clinical features, structural progression, and total knee replacement (TKR).

DESIGN

MEDLINE and EMBASE were systematically searched for controlled trials and cohort studies of participants with (or at risk of) KOA examining the relationship between weight gain and KOA clinical features (pain, function, quality of life), structural progression, and TKR. Risk of bias was assessed using the ROBINS-I tool. Results were organised by outcome, with meta-analyses performed where appropriate.

RESULTS

Twenty-three studies were included. Results showed significant detrimental effects of weight gain on pain (4 of 7 studies), stiffness (2 of 2 studies), function (5 of 6 studies), and the single studies examining quality of life, and clinical and radiographic KOA. Weight gain adversely affected cartilage (6 of 9 studies), bone marrow lesions (1 of 4 studies), meniscal damage (1 of 3 studies) and effusion/synovitis (1 of 1 study). Weight gain significantly increased TKR (3 of 6 studies): meta-analysis of 2 with available data demonstrated significant increases in TKR/5 kg weight gain in women, HR 1.34 (95% CI 1.18-1.51), and in men, HR 1.25 (95% CI 1.16-1.34).

CONCLUSIONS

Weight gain in adults is associated with increased clinical and structural KOA and TKR. Prevention of weight gain should be considered to improve outcomes in KOA.

Metformin as a potential disease-modifying drug in osteoarthritis: a systematic review of pre-clinical and human studies

OBJECTIVE

Osteoarthritis causes significant pain and disability with no approved disease-modifying drugs. We systematically reviewed the evidence from both pre-clinical and human studies for the potential disease-modifying effect of metformin in osteoarthritis.

METHODS

Ovid Medline, Embase and CINAHL were searched between inception and June 2021 using MeSH terms and key words to identify studies examining the association between metformin use and outcome measures related to osteoarthritis. Two reviewers performed the risk of bias assessment and 3 reviewers extracted data independently. Qualitative evidence synthesis was performed. This systematic review is registered on PROSPERO (CRD42021261052 and CRD42021261060).

RESULTS

Fifteen (10 pre-clinical and 5 human) studies were included. Most studies (10 pre-clinical and 3 human) assessed the effect of metformin using knee osteoarthritis models. In pre-clinical studies, metformin was assessed for the effect on structural outcomes (n = 10); immunomodulation (n = 5); pain (n = 4); and molecular pathways of its effect in osteoarthritis (n = 7). For human studies, metformin was evaluated for the effect on structural progression (n = 3); pain (n = 1); and immunomodulation (n = 1). Overall, pre-clinical studies consistently showed metformin having a chondroprotective, immunomodulatory and analgesic effect in osteoarthritis, predominantly mediated by adenosine monophosphate-activated protein kinase activation. Evidence from human studies, although limited, was consistent with findings in pre-clinical studies.

CONCLUSION

We found consistent evidence across pre-clinical and human studies to support a favourable effect of metformin on chondroprotection, immunomodulation and pain reduction in knee osteoarthritis. Further high-quality clinical trials are needed to confirm these findings as metformin could be a novel therapeutic drug for the treatment of osteoarthritis.

Engineered aluminum nanoparticle induces mitochondrial deformation and is predicated on cell phenotype

The main role of mitochondria is to generate the energy necessary for the cell to survive and adapt to different environmental stresses. Energy demand varies depending on the phenotype of the cell. To efficiently meet metabolic demands, mitochondria require a specific proton homeostasis and defined membrane structures to facilitate adenosine triphosphate production. This homeostatic environment is constantly challenged as mitochondria are a major target for damage after exposure to environmental contaminants. Here we report changes in mitochondrial structure profiles in different cell types using electron microscopy in response to particle stress exposure in three different representative lung cell types. Endpoint analyses include nanoparticle intracellular uptake; quantitation of mitochondrial size, shape, and ultrastructure; and confirmation of autophagosome formation. Results show that low-dose aluminum nanoparticles exposure (1 ppm; 1 µg/mL; 1.6 × 1 0^-7µg/cell)) to primary and asthma cells incurred significant mitochondrial deformation and increases in mitophagy, while cancer cells exhibited only slight changes in mitochondrial morphology and an increase in lipid body formation. These results show low-dose aluminum nanoparticle exposure induces subtle changes in the mitochondria of specific lung cells that can be quantified with microscopy techniques. Furthermore, within the lung, cell type by the nature of origin (i.e. primary vs. cancer vs. asthma) dictates mitochondrial morphology, metabolic health, and the metabolic stress response of the cell.

Effects of Se nanoparticles supplementation on growth performance, hematological parameters and nutrient digestibility of Labeo rohita fingerling fed sunflower meal based diet

The aim of the present study is to assess the effects of selenium nanoparticles on the growth, hematology and nutrients digestibility of Labeorohita fingerlings. Fingerlings were fed with seven isocaloric sunflower meal-based diet supplemented with different concentrations of nanoparticles naming T1 to T7 (0, 0.5, 1, 1.5, 2, 2.5, and 3 mg/kg), with 5% wet body weight while chromic oxide was used as an indigestible marker. After experimentation for 90 days T3 treated group (1mg/kg -1Se-nano level) showed the best result in hematological parameters (WBC's 7.97 ×103mm-3, RBC's 2.98 ×106 mm-3 and Platelet count 67), nutrient digestibility (crude protein: 74%, ether extract: 76%, gross energy: 70%) and growth performance (weight gain 13.24 g, weight gain% 198, feed conversion ratio 1.5, survival rate 100%) as compared to the other treatment groups. Specific growth rates were found significantly higher in T5 than in other groups. The present study indicated positive effect of 1 mg/kg Se-nanoparticles on growth advancement, hematological parameters, and nutrients digestibility of L. rohita fingerlings.

Studies on parasitic prevalence in pet birds from Punjab, Pakistan

During this one year study, blood and fecal samples of doves (Zenaida asiatica), ducks (Anas platyrhynchos), pigeons (Columba livia), partridges (Alectoris chukar), turkeys (Meleagris gallopavo) and goose (Chen caerulescens) were collected to assess the parasitic prevalence in these birds. The birds were kept at Avian Conservation and Research Center, Department of Wildlife and Ecology, University of Veterinary and Animal Sciences, Lahore. All these avian species were kept in separate cages and their entire body was inspected on regularly basis to record external parasites. For internal parasites, 100 blood and 100 fecal samples for each species were analyzed. During present study, two species of ectoparasites i.e. fowl ticks (Args persicus) and mite (Dermanyssus gallinae) while 17 species of endoparasites; three from blood and 14 from fecal samples were identified. Prevalence of blood parasites was Plasmodium juxtanucleare 29.3%, Aegyptinella pullorum 15% and Leucoctoyzoon simond 13%. Parasitic species recorded from fecal samples included 6 species of nematodes viz. Syngamus trachea with parasitic prevalence of 50%, Capillaria anatis 40%, Capillaria annulata 37.5%, Heterakis gallinarum 28.3%, Ascardia galli 24% and Allodpa suctoria 2%. Similarly, two species of trematodes viz. Prosthogonimus ovatus having parasitic prevalence of 12.1% and Prosthogonimus macrorchis 9.1% were also recorded from fecal samples of the birds. Single cestode species Raillietina echinobothrida having parasitic prevalence of 27% and 3 protozoan species i.e. Eimeria maxima having prevalence 20.1%, Histomonas meleagridis 8% and Giardia lamblia 5.3% were recorded. In our recommendation, proper medication and sanitation of the bird's houses and cages is recommended to avoid parasites.

Partial replacement of fish meal with Moringa oleifera leaf meal in practical diets of Cirrhinus mrigala fingerlings

Fish protein is serving as a source of nutrition for protein starving world. However, sustainable aquaculture products require inexpensive plant by-products due to finite sources of fish meal. Therefore, this study was conducted to examine nutrient utilization, growth performance and hematological indices of Cirrhinus mrigala fingerlings fed on Moringa oleifera leaf meal (MOLM) based diets. Fish were fed with six isonitrogenous and isoenergetic diets having MOLM as a substitute of fish meal (FM) at the levels of 0%, 10%, 20%, 30%, 40% and 50% for the period of 90 days. Fingerlings having initial weight 6.35±0.04g were reared in triplicate tanks at the stocking density of 15 and hand fed at the rate of 5% of total biomass twice regularly. Chromic oxide inclusion level was 1% in diets. After analysis, maximum growth performance and improved digestibility of nutrients were found in fish fed with diet at 10% replacement level as compared to fish fed on control diet and other test diets. Additionally, it was found that the red blood cells, white blood cells, hemoglobin and mean corpuscular hemoglobin concentration of fish showed a significantly (p<0.05) inverse correlation with the increase in MOLM. In present research, it was concluded that MOLM has good potential to be used as a FM substitute in C. mrigala diet with maximum effect at 10% showing positive hematological indices.

Efficacy of acidified phytase supplemented cottonseed meal based diets on growth performance and proximate composition of Labeo rohita fingerlings

The growth of aquaculture sector is strongly dependent upon the continuous supply of inexpensive fish feed with balanced nutritional profile. However, fish meal (FM) is unable to satisfy this demand due to its scarce supply and high cost. In order to test the potential of cottonseed meal (CSM) as a fish meal replacer, a feeding trial of 12 weeks was conducted to check growth performance and proximate composition of Labeo rohita fingerlings. The protein ration of the test feed was satisfied by replacing FM with CSM at 0, 25, 50 and 75%. Sixteen test diets viz., TD1 (control), TD2, TD3, TD4, TD5, TD6, TD7, TD8, TD9, TD10, TD11, TD12, TD13, TD14, TD15 and TD16 were supplemented with citric acid (CA; 0 and 2.5%) and phytase (PHY; 0 and 750 FTU/kg) in a completely randomized design with 3×3 factorial arrangement. The highest weight gain (11.03g), weight gain% (249.21%), specific growth rate (1.39) and best feed conversion ratio (1.20) were recorded by fish fed with TD12. Furthermore, the same level increased the crude protein (59.26%) and fat (16.04%) being significantly different (p<0.05) than that of control. Conclusively, the addition of acidified phytase (CA; 2.5%, PHY; 750 FTU/kg) in TD12 (CSM=50%) led to the improved growth and proximate composition of L. rohita fingerlings.

Impact of dietary leaf extracts of Black pepper Piper nigrum L. on the growth, hematological and immunological parameters of Labeo rohita (Hamilton, 1822) cultured in glass aquaria

A study was conducted to evaluate the effect of Piper nigrum (black pepper) leaf extract on on the growth performance, proximate composition, hematological parameters, and immune response of Labeo rohita fingerlings with an average weight of 22.14 ± 0.98g. Aftrer acclimation for two weeks, fish (n=25) were randomly selected and placed in four glass aquaria (T0, T1, T2 and T3) at constant water temperature (30.0 ± 1.0 °C), pH (7.50 ± 0.5) and total hardness (200 ± 2.0 mgL,-1) for a period of 12 weeks, with three replicates each. Fish were fed with P. nigrum leaf extract supplemented feed @ 0.0%, 1.0%, 2.0% and 3.0% in T0, T1,T2 and T3, respectively. At the end of experiment, five fish were randomly selected from each aquaria for proximate composition, gut and skin microbial load, hematological parameters. Total proteins, albumins, and globulins were also recorded to evaluate immunological memory. The result revealed that fish in T2 showed better growth performance with an average weight gain of 56.11 ± 0.51 g. Thus, it had been concluded that Piper nigrum, a medicinal plant, can also be used to enhance the growth performance and immune response of Labeo rohita as attractive alternatives against antibiotics and vaccines and has shown no negative side effects on fish health as well as on its environment.

Examining cellular responses to reconstituted antibody protein liquids

Protein ionic liquids (PIL) are a new class of biologic stabilizers designed to protect the functionality and extend the shelf-life of biotechnological and therapeutic agents making them more readily available, and resistant to austere environments. Protein biorecognition elements such as monoclonal antibodies are commonly utilized therapeutics that require the robust stabilization offered by PILs, but biocompatibility remains an important issue. This study has focused on characterizing the biocompatibility of an antibody based PIL by exposing multiple cells types to a cationized immunoglobulin suspended in an anionic liquid (IgG-IL). The IgG-IL caused no significant alterations in cellular health for all three cell types with treatments < 12.5 µg/mL. Concentrations ≥ 12.5 µg/mL resulted in significant necrotic cell death in A549 and HaCaT cells, and caspase associated cell death in HepG2 cells. In addition, all cells displayed evidence of oxidative stress and IL-8 induction in response to IgG-IL exposures. Therapeutic Ig can be utilized with a wide dose range that extends into concentrations we have found to exhibit cytotoxicity raising a toxicity concern and a need for more extensive understanding of the biocompatibility of IgG-ILs.

Variations in nutritional profile of honey produced by various species of genus Apis

The medicinal attributes of honey appears to overshadow its importance as a functional food. Consequently, several literatures are rife with ancient uses of honey as complementary and alternative medicine, with relevance to modern day health care, supported by evidence-based clinical data, with little attention given to honey's nutritional functions. The moisture contents of honey extracted from University of Veterinary and Animal Sciences, Lahore honey bee farm was 12.19% while that of natural source was 9.03 ± 1.63%. Similarly, ash and protein contents of farmed honey recorded were 0.37% and 5.22%, respectively. Whereas ash and protein contents of natural honey were 1.70 ± 1.98% and 6.10 ± 0.79%. Likewise fat, dietary fiber and carbohydrates contents of farmed source documented were 0.14%, 1.99% and 62.26% respectively. Although fat, dietary fiber and carbohydrates contents of honey taken from natural resource were 0.54 ± 0.28%, 2.76 ± 1.07% and 55.32 ± 2.91% respectively. Glucose and fructose contents of honey taken out from honeybee farm were 27% and 34% but natural source were 22.50 ± 2.12% and 28.50 ± 3.54%. Glucose and fructose contents of honey taken out from honeybee farm were 27% and 34% but natural source were 22.50 ± 2.12% and 28.50 ± 3.54%. Similarly, sucrose and maltose contents of farmed honey were 2.5% and 12% while in natural honey were 1.35 ± 0.49% and 8.00 ± 1.41% respectively. The present study indicates that such as moisture, carbohydrates, sucrose and maltose contents were higher farmed honey as compared to the natural honey. In our recommendation natural honey is better than farmed honey.

Use of phytase and citric acid supplementation on growth performance and nutrient digestibility of Cirrhinus mrigala fingerlings fed on canola meal based diet

Fishmeal; being a limited and costly feed ingredient is continuously been substituted with locally available plant proteins. However, the occurrence of anti-nutritional factors in plant meal suppresses its potential to be fully replaced. Therefore, in this study we aimed to study the synergistic effects of dietary additives like citric acid and phytase enzyme supplementation on growth performance and nutrient digestibility of Cirrhinus mrigala fingerlings. Canola meal (CM) was used as a test ingredient to replace fishmeal (FM) as; 0%, 25%, 50% and 75%. These four diets were further supplemented by varying levels of phytase (0 and 750 FTU kg-1) and citric acid (0% and 2.5%) to formulate total sixteen test diets as T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15 and T16. Each treatment contained three replicates; applied to fish groups having 15 fingerlings each; following 3×3 factorial arrangement. 1% of chromic oxide was added as an inert marker. Maximum weight gain% (288%) and the lowest value of FCR (1.07) were recorded when fish was fed on diet T12 as compared to fish fed control diet (T1). Similarly, optimum nutrient digestibility values such as crude protein (77%), crude fat (84%) and gross energy (70%) were noted on same level. It was concluded that 50% canola meal can optimally replace fishmeal when supplemented with phytase and citric acid at the levels of 750 FTU kg-1 and 2.5%, respectively.

Characterization and distribution of microplastics in estuarine surface sediments, Kayamkulam estuary, southwest coast of India

The present study aims to formulate the characterization and distribution of microplastic in the estuarine surface sediments of Kayamkulam estuary, southwest coast of India. The sediments were dominated by fibre and film shaped microplastic substances. The surface sediments were dominated by <1000 μm microplastics. The composition of microplastics in descending order was as follows: polyester > polypropylene > polyethylene. The distribution of microplastics was significantly higher than that observed in the other study regions, except for Pearl river estuary and Guanabara Bay. The distribution of microplastics was chiefly controlled by estuarine inundating water and the distance of the sampling site from the open sea.

The COVID-19 Infodemic: A Quantitative Analysis Through Facebook

Background Social media is a crucial part of our daily life. Facebook, being the biggest social media platform, plays a significant role in the spread of information influencing the global response to the COVID-19 pandemic. Health care agencies like the World Health Organization (WHO) and Centers for Disease Control and Prevention (CDC) use social media as a platform to impart information regarding COVID-19; simultaneously, there is a spread of misinformation on social media, masking the credible sources of information. Our research aims to assess the utility of Facebook in providing misinformation and testing its "fact-check policy." Methods An online search was conducted on Facebook by a newly created account to eliminate bias. The Facebook search bar was used to investigate multiple keywords. Data were tabulated in Microsoft Excel (Microsoft Corporation, Redmond, WA). Descriptive statistical analysis of Facebook accounts and posts was done using the Statistical Package for the Social Sciences (SPSS) version 26 (IBM Corp., Armonk, NY) while statistical importance was set a priority at a p-value of 0.05. Results Our study consisted of 454 Facebook posts. Most (22.5%) were posted by verified accounts and 23.9% by informal individual/group accounts. The tone for most (40.4%) COVID-19 information was serious while the most common (43.9%) topic was medical/public health. In total, 22.3% included misinformation, 19.6% were unverifiable, and 27.5% included correct information verifiable by the WHO or CDC. Conclusions Misinformation/unverifiable information related to the COVID-19 crisis is spreading at a distressing rate on social media. We quantified the misinformation and tested Facebook's "fact-check policy." We advise strict initiatives to control this infodemic and advise future researches to evaluate the accuracy of content being circulated on other social media platforms.

Does preoperative neuropathic-like pain and central sensitisation affect the post-operative outcome of knee joint replacement for osteoarthritis? A systematic review and meta analysis

BACKGROUND

Almost a third of those undergoing knee replacement for osteoarthritis have poor outcomes despite technically successful surgery. Preoperative neuropathic-like pain and/or pain sensitisation may increase the risk of pain following joint replacement.

OBJECTIVE

To examine whether preoperative neuropathic-like pain and pain sensitisation predicts pain, function and satisfaction following joint replacement for knee osteoarthritis.

DESIGN

Systematic review with meta-analysis.

METHODS

Medline, EMBASE and CINAHL were systematically searched until March 2020. Studies detecting neuropathic-like pain and/or sensitisation using self-report questionnaires prior to knee replacement for osteoarthritis, and relating this to post-operative outcomes were identified. Data extraction, risk of bias assessment and meta-analysis were performed, where appropriate.

RESULTS

Five manuscripts, including one preprint, examining six cohorts were included: four used painDETECT or modified painDETECT, one the Self-Report Leeds Assessment of Neuropathic Symptoms and Signs, and another the Central Sensitisation Inventory to identify preoperative characteristics. Three studies showed preoperative neuropathic-like pain or sensitisation was associated with more intense post-operative pain. All four studies examining the risk of significant pain after knee replacement suggested it was increased after >3 months. The only study examining patient satisfaction and function found reduced satisfaction, but no difference in function in those with preoperative sensitisation. Meta-analysis found the relative risk of increased pain following knee replacement in those with neuropathic-like pain (painDETECT ≥13) to be 2.05 (95% confidence intervals 1.51, 2.79).

CONCLUSION

These results provide consistent but limited evidence that self-report tools detecting neuropathic-like pain and/or pain sensitisation, predict patients at higher risk of pain following knee replacement.

A baseline study on elemental concentration and potential ecological risk status of the surface sediments of Ashtamudi Lake, south west coast of India

Element concentration (Fe, Mn, Pb, Zn, Cu, Cr, Ni and Co) in the surface sediments of Ashtamudi estuary, Southwest coast of India, has been analyzed to understand the spatial variation and potential ecological risk status. The sediment pollution index and Potential Ecological Risk index suggest that the northeastern part of the estuary exhibits low to moderate polluted sediments with moderate ecological risk. The results of correlation analysis indicate that the natural weathering process and river input play an important role in the distribution of the elements in the surface sediments of the estuary. The extracted factor results indicate that the fine sediment fractions supporting for accumulation of the trace elements, whereas the enriched level of Fe and Mn is chiefly controlled by the riverine process, and other elements are contributed by anthropogenic influences.

Human Nontumorigenic Microglia Synthesize Strongly Fluorescent Au/Fe Nanoclusters, Retaining Bioavailability

The ability for cells to self-synthesize metal-core nanoclusters (mcNCs) offers increased imaging and identification opportunities. To date, much work has been done illustrating the ability for human tumorigenic cell lines to synthesize mcNCs; however, this has not been illustrated for nontumorigenic cell lines. Here, we present the ability for human nontumorigenic microglial cells, which are the major immune cells in the central nervous system, to self-synthesize gold (Au) and iron (Fe) core nanoclusters, following exposures to metallic salts. We also show the ability for cells to internalize presynthesized Au and Fe mcNCs. Cellular fluorescence increased in most exposures and in a dose dependent manner in the case of Au salt. Scanning transmission electron microscopic imaging confirmed the presence of the metal within cells, while transmission electron microscopy images confirmed nanocluster structures and self-synthesis. Interestingly, self-synthesized nanoclusters were of similar size and internal structure as presynthesized mcNCs. Toxicity assessment of both salts and presynthesized NCs illustrated a lack of toxicity from Au salt and presynthesized NCs. However, Fe salt was generally more toxic and stressful to cells at similar concentrations.

In Vitro Aerosol Exposure to Nanomaterials: From Laboratory to Environmental Field Toxicity Testing

Exposure to nanomaterials (NMs) is inevitable, requiring robust toxicological assessment to understand potential environmental and human health effects. NMs are favored in many applications because of their small size; however, this allows them to easily aerosolize and, subsequently, expose humans via inhalation. Toxicological assessment of NMs by conventional methods in submerged cell culture is not a relevant way to assess inhalation toxicity of NMs because of particle interference with bioassays and changes in particokinetics when dispersed in medium. Therefore, an in vitro aerosol exposure chamber (AEC) was custom designed and used for direct deposition of NMs from aerosols in the environment to the air-liquid interface of lung cells. Human epithelial lung cell line, A549, was used to assess the toxicity of copper, nickel, and zinc oxide nanopowders aerosolized by acoustic agitation in laboratory study. Post optimization, the AEC was used in the field to expose the A549 cells to NM aerosols generated from firing a hand gun and rifle. Toxicity was assessed using nondestructive assays for cell viability and inflammatory response, comparing the biologic effect to the delivered mass dose measured by inductively coupled plasma-mass spectrometry. The nanopowder exposure to submerged and ALI cells resulted in dose-dependent toxicity. In the field, weapon exhaust from the M4 reduced cell viability greater than the M9, while the M9 stimulated inflammatory cytokine release of IL-8. This study highlights the use of a portable chamber with the capability to assess toxicity of NM aerosols exposed to air-liquid interface in vitro lung cell culture.

Depletion of phosphatidylinositol 4-phosphate at the Golgi translocates K-Ras to mitochondria

Ras proteins are small GTPases localized to the plasma membrane (PM), which regulate cellular proliferation, apoptosis and differentiation. After a series of post-translational modifications, H-Ras and N-Ras traffic to the PM from the Golgi via the classical exocytic pathway, but the exact mechanism of K-Ras trafficking to the PM from the ER is not fully characterized. ATP5G1 (also known as ATP5MC1) is one of the three proteins that comprise subunit c of the F ₀ complex of the mitochondrial ATP synthase. In this study, we show that overexpression of the mitochondrial targeting sequence of ATP5G1 perturbs glucose metabolism, inhibits oncogenic K-Ras signaling, and redistributes phosphatidylserine (PtdSer) to mitochondria and other endomembranes, resulting in K-Ras translocation to mitochondria. Also, it depletes phosphatidylinositol 4-phosphate (PI4P) at the Golgi. Glucose supplementation restores PtdSer and K-Ras PM localization and PI4P at the Golgi. We further show that inhibition of the Golgi-localized PI4-kinases (PI4Ks) translocates K-Ras, and PtdSer to mitochondria and endomembranes, respectively. We conclude that PI4P at the Golgi regulates the PM localization of PtdSer and K-Ras.This article has an associated First Person interview with the first author of the paper.

Achievements and Challenges for Real-Time Sensing of Analytes in Sweat within Wearable Platforms

Physiological sensors in a wearable form have rapidly emerged on the market due to technological breakthroughs and have become nearly ubiquitous with the Apple Watch, FitBit, and other wearable devices. While these wearables mostly monitor simple biometric signatures, new devices that can report on the human readiness level through sensing molecular biomarkers are critical to optimizing the human factor in both commercial sectors and the Department of Defense. The military is particularly interested in real-time, wearable, minimally invasive monitoring of fatigue and human performance to improve the readiness and performance of the war fighter. However, very few devices have ventured into the realm of reporting directly on biomarkers of interest. Primarily this is because of the difficulties of sampling biological fluids in real-time and providing accurate readouts using highly selective and sensitive sensors. When additional restrictions to only use sweat, an excretory fluid, are enforced to minimize invasiveness, the demands on sensors becomes even greater due to the dilution of the biomarkers of interest, as well as variability in salinity, pH, and other physicochemical variables which directly impact the read-out of real-time biosensors. This Account will provide a synopsis not only on exemplary demonstrations and technological achievements toward implementation of real-time, wearable sweat sensors but also on defining problems that still remain toward implementation in wearable devices that can detect molecular biomarkers for real world applications. First, the authors describe the composition of minimally invasive biofluids and then identify what biomarkers are of interest as biophysical indicators. This Account then reviews demonstrated techniques for extracting biofluids from the site of generation and transport to the sensor developed by the authors. Included in this discussion is a detailed description on biosensing recognition elements and transducers developed by the authors to enable generation of selective electrochemical sensing platforms. The authors also discuss ongoing efforts to identify biorecognition elements and the chemistries necessary to enable high affinity, selective biorecognition elements. Finally, this Account presents the requirements for wearable, real-time sensors to be (1) highly stable, (2) portable, (3) reagentless, (4) continuous, and (5) responsive in real-time, before delving into specific methodologies to sense classes of biomarkers that have been explored by academia, government laboratories, and industry. Each platform has its areas of greatest utility, but also come with corresponding weaknesses: (1) ion selective electrodes are robust and have been demonstrated in wearables but are limited to detection of ions, (2) enzymatic sensors enable indirect detection of metabolites and have been demonstrated in wearables, but the compounds that can be detected are limited to a subset of small molecules and the sensors are sensitive to flow, (3) impedance-based sensors can detect a wide range of compounds but require further research and development for deployment in wearables. In conclusion, while substantial progress has been made toward wearable molecular biosensors, substantial barriers remain and need to be solved to enable deployment of minimally invasive, wearable biomarker monitoring devices that can accurately report on psychophysiological status.

Condensational particle growth device for reliable cell exposure at the air-liquid interface to nanoparticles

A first-of-its-kind aerosol exposure device for toxicity testing, referred to as the Dosimetric Aerosol in Vitro Inhalation Device (DAVID), was evaluated for its ability to deliver airborne nanoparticles to lung cells grown as air-liquid interface (ALI) cultures. For inhalation studies, ALI lung cell cultures exposed to airborne nanoparticles have more relevancy than the same cells exposed in submerged culture because ALI culture better represents the respiratory physiology and consequently more closely reflect cellular response to aerosol exposure. In DAVID, water condensation grows particles as small as 5 nm to droplets sized > 5 μm for inertial deposition at low flow rates. The application of DAVID for nanotoxicity analysis was evaluated by measuring the amount and variability in the deposition of uranine nanoparticles and then assessing the viability of ALI cell cultures exposed to clean-air under the same operational conditions. The results showed a low coefficient of variation, < 0.25, at most conditions, and low variability in deposition between the exposure wells, trials, and operational flow rates. At an operational flow rate of 4 LPM, no significant changes in cell viability were observed, and minimal effects observed at 6 LPM. The reliable and gentle deposition mechanism of DAVID makes it advantageous for nanoparticle exposure.

Implementation of physiological fluids to provide insight into the characterization, fate, and biological interactions of silver nanoparticles

Silver nanoparticles (AgNPs) are being increasingly utilized in consumer and medical applications. However, there remains conflicting reports on their safety, which are evaluated through a combination of in vitro and in vivo exposure models. These discrepancies may arise, in part, due to the inherent differences between cell-based and animal systems. It is well established that nanotoxicological effects are highly dependent on the unique physicochemical properties and behavior of the particle set, including size, surface chemistry, agglomeration, and ionic dissolution. However, recent studies have identified that these properties vary as a function of exposure environment; providing a rationale for the contradictory results between in vitro and in vivo assessments. Artificial physiological fluids are emerging as a powerful tool as they allow for the characterization of NPs in an environment which they would likely encounter in vivo, in addition to having the experimental advantages of flexibility and consistency. Here, we demonstrated that the utilization of artificial fluids provided a mechanism to assess AgNP behavior and induced bioresponses in environments that they would likely encounter in vivo. AgNPs were introduced within an alveolar-based exposure model, which included alveolar epithelial (A549) cells incubated within artificial alveolar fluid (AF). Additionally, the particles underwent extensive characterization within both AF and lysosomal fluid, which the AgNPs would encounter following cellular internalization. Following incubation in physiological environments AgNP properties were significantly modified versus a traditional media environment, including alterations to both extent of agglomeration and rate of ionic dissolution. Moreover, when A549s were exposed to AgNPs in AF, the cells displayed lower cytotoxicity and stress rates, corresponding to a fluid-dependent drop in silver ion production. This work highlights the need for enhanced in vitro models that more closely mimic in vivo exposure environments in order to capture true NP behaviors and cellular interactions.

Relationship of weight and obesity with the risk of knee and hip arthroplasty for osteoarthritis across different levels of physical performance: a prospective cohort study

OBJECTIVE

To examine the association between obesity and knee and hip arthroplasty for osteoarthritis across a range of physical performance.

METHOD

The body mass index and physical performance (on the 36-item Short Form Health Survey) of 9135 Australian Diabetes, Obesity and Lifestyle Study participants were measured in 1999-2000. The incidence of knee and hip arthroplasty during 2002-2011 was determined by linking the cohort records to the Australian Orthopaedic Association National Joint Replacement Registry.

RESULTS

Over 9.1 ± 2.3 years (mean ± sd)) of follow-up, 317 participants had knee and 202 had hip arthroplasty for osteoarthritis. Using those with neither obesity nor significantly impaired physical performance as the reference group, participants with both obesity and significantly impaired physical performance had a higher knee arthroplasty risk [hazard ratio (HR) = 5.25, 95% confidence interval (CI) 3.85-7.14] than those with obesity alone (HR = 2.49, 95% CI 1.81-3.44) or impaired physical performance alone (HR = 2.19, 95% CI 1.59-3.02). Similar results were observed for hip arthroplasty (obesity and impaired physical performance: HR = 2.67, 95% CI 1.72-4.15; obesity alone: HR = 1.65, 95% CI 1.08-2.51; impaired physical performance alone: HR = 1.83, 95% CI 1.26-2.66). Among overweight/obese patients, 5 kg greater baseline weight increased the knee arthroplasty risk across all levels of physical performance, and hip arthroplasty risk in those with the highest level of physical performance.

CONCLUSION

Although impaired physical performance is an independent risk factor for knee and hip arthroplasty, greater weight increased knee arthroplasty for overweight/obese participants at all levels of physical performance, but hip arthroplasty only in those with good physical performance. Targeting weight loss has the potential to reduce the risk of knee arthroplasty and improve patient outcomes, even in those with poor physical performance.

Development of reference metal and metal oxide engineered nanomaterials for nanotoxicology research using high throughput and precision flame spray synthesis approaches

There is a growing need to develop and characterize reference metal and metal oxide engineered nanomaterials (ENMs) of high purity and tunable intrinsic properties suitable for nanotoxicology research. Here a high throughput (volume) and precision flame spray pyrolysis (FSP) approach coupled with state-of-the-art characterization techniques are utilized to generate such reference ENMs. The lab-based and industrially relevant FSP system, termed as Versatile Engineered Nanomaterials Generation System (VENGES), synthesizes the metals and metal oxides, at high throughput manner with controlled properties, such as primary particle size, aggregate diameter, shape, crystallinity, stoichiometry and surface chemistry. A nanopanel of nine reference ENMs (silica, silver, silver supported on silica, alumina, ceria and iron oxide) was synthesized and characterized using combined electron microscopy, advanced spectroscopic techniques and physical analyses (e.g., BET, XRD, TEM, pycnometry, XPS, ICP-MS and FTIR). ENMs show a high degree of chemical purity and stoichiometry, and low content of carbon residuals, and are sterile and free of bacteria and endotoxins. Further, their colloidal properties and their implication in in-vitro dosimetry have been also investigated in both environmental and test biological media. The suitability of reference ENMs and protocols developed in this study brings forth new arenas to generate reliable and reproducible toxicological data in an effort to reduce conflicting and contradicting inter-laboratory data on relative toxic effects of ENMs.

Female hormonal factors and osteoarthritis of the knee, hip and hand: a narrative review

Osteoarthritis is a leading cause of disability with no cure. The incidence of osteoarthritis is sexually dimorphic: women have a higher rate of osteoarthritis than men after the age of 50. Research has investigated the contribution of sex hormones, reproductive factors and hormone supplementation to osteoarthritis. It has been recognized that different joints are susceptible to different risk factors for osteoarthritis. We reviewed the evidence for the effect of endogenous sex hormones, reproductive factors and hormone supplementation on joint-specific osteoarthritis of the knee, hip and hand. Although the role of these hormonal factors in the pathogenesis of osteoarthritis is complex, data suggest that endogenous hormones and reproductive factors have a role in the pathogenesis of osteoarthritis, especially knee osteoarthritis, with uncertainty for the effect of exogenous hormones. From the available data, it is hard to conclude whether this is a direct effect of hormonal factors, or whether other factors related to these hormonal factors, i.e. obesity and inflammation, have a role in this association. Further studies should consider the mediation effect of body weight and inflammation, change in body weight throughout life, circulatory levels of all endogenous hormones and circulatory levels of hormones after hormone supplementation in this complex relationship.

Characterization of exposure to byproducts from firing lead-free frangible ammunition in an enclosed, ventilated firing range

U.S. Air Force small arms firing ranges began using copper-based, lead-free frangible ammunition in the early 2000s due to environmental and health concerns related to the use of lead-based ammunition. Exposure assessments at these firing ranges have routinely detected chemicals and metals in amounts much lower than their mass-based occupational exposure limits, yet, instructors report work-related health concerns including respiratory distress, nausea, and headache. The objective of this study at one firing range was to characterize the aerosol emissions produced by weapons during firing events and evaluate the ventilation system's effectiveness in controlling instructor exposure to these emissions. The ventilation system was assessed by measuring the range static air pressure differential and the air velocity at the firing line. Air flow patterns were near the firing line. Instructor exposure was sampled using a filter-based air sampling method for metals and a wearable, real-time ultrafine particle counter. Area air sampling was simultaneously performed to characterize the particle size distribution, morphology, and composition. In the instructor's breathing zone, the airborne mass concentration of copper was low (range = <1 µg/m³ to 16 µg/m³), yet the ultrafine (nanoscale) particle number concentration increased substantially during each firing event. Ultrafine particles contained some copper and were complex in morphology and composition. The ventilation assessment found that the average velocity across all shooting lanes was acceptable compared to the recommended guideline (20% of the ideal 0.38 m/s (75 ft/min). However, uniform, downrange airflow pattern requirements were not met. These results suggest that the mass-based occupational exposure limits, as applied to this environment, may not be protective enough to eliminate health complaints reported by instructors whose full-time job involves training personnel on weapons that fire lead-free frangible ammunition. Using an ultrafine particle counter appears to be an alternative method of assessing ventilation effectiveness in removing ultrafine particulate produced during firing events.

Assessment of Metal Nanoparticle Agglomeration, Uptake, and Interaction Using High-Illuminating System

In the present study, an ultrahigh-resolution system was applied as a simple and convenient technique to characterize the extent of metal nanoparticle agglomeration in solution and to visualize nanoparticle agglomeration, uptake, and surface interaction in three cell phenotypes under normal culture conditions. The experimental results demonstrated that silver (25, 80, 130 nm); aluminum (80 nm); and manganese (40 nm) particles and agglomerates were effectively internalized by rat liver cells (BRL 3A), rat alveolar macrophages (MACs), and rat neuroendocrine cells (PC-12). Individual and agglomerated nanoparticles were observed within the cells and agglomerates were observed on the cell surface membranes. The particles were initially dispersed in aqueous or physiological balanced salt solutions and agglomeration was observed using the Ultra Resolution Imaging (URI) system. Different methods, such as sonication and addition of surfactant (0.1% sodium dodecyl sulfate [SDS]) reduced agglomeration. Due to effects of SDS itself on cell viability, the surfactant could not be directly applied during cell exposure. Therefore, following addition of 0.1% SDS, the particles were washed twice with ultrapure water, which reduced agglomeration even further. Reducing the agglomeration of the nanoparticles is important for studying their uptake and in applications that benefit from individual nanoparticles such as diagnostics. In summary, this study demonstrates a simple technique to characterize the extent of nanoparticle agglomeration in solution and visualize nanoparticle (40 nm and larger) uptake and interaction with cells. Additionally, an example application of nanoparticle labeling onto the surface and neurite extensions of murine neuroblastoma cells (N2A) is presented as a potential imaging tool.

Modulation of miRNA-155 alters manganese nanoparticle-induced inflammatory response

Regulation of gene expression by non-coding RNAs, such as microRNAs (miRNAs), is increasingly being examined in a variety of disciplines. Here we evaluated changes in miRNA expression following metallic nanoparticle (NP) exposure in a mouse neuronal co-culture model. Exposure to manganese (Mn) NPs resulted in oxidative stress, inflammation, and toxicity. Next-generation sequencing (NGS) following an 8 h exposure to Mn NPs (low and high doses) revealed several miRNA candidates that modulate NP induced responses. The lead candidate identified was miR-155, which showed a dose dependent decrease in expression upon Mn exposure. Introduction of a miR-155 mimic into the co-culture to restore miR-155 expression completely abrogated the Mn NP-induced gene and protein expression of inflammatory markers TNF-α and IL-6. Taken together, this study is the first report where global NP-induced miRNA expression changes were used to identify and then modulate negative impacts of metallic NP exposure in a neuronal model. These findings demonstrate that unique miRNA expression profiles provide novel targets for manipulating gene and protein expression, and therefore provide the potential of modifying cellular responses to NP exposure.

In situ Synthesis of Fluorescent Gold Nanoclusters by Nontumorigenic Microglial Cells

To date, the directed in situ synthesis of fluorescent gold nanoclusters (AuNCs) has only been demonstrated in cancerous cells, with the theorized synthesis mechanism prohibiting AuNC formation in nontumorigenic cell lines. This limitation hinders potential biostabilized AuNC-based technology in healthy cells involving both chemical and mechanical analysis, such as the direct sensing of protein function and the elucidation of local mechanical environments. Thus, new synthesis strategies are required to expand the application space of AuNCs beyond cancer-focused cellular studies. In this contribution, we have developed the methodology and demonstrated the direct in situ synthesis of AuNCs in the nontumorigenic neuronal microglial line, C8B4. The as-synthesized AuNCs form in situ and are stabilized by cellular proteins. The clusters exhibit bright green fluorescence and demonstrate low (<10%) toxicity. Interestingly, elevated ROS levels were not required for the in situ formation of AuNCs, although intracellular reductants such as glutamate were required for the synthesis of AuNCs in C8B4 cells. To our knowledge, this is the first-ever demonstration of AuNC synthesis in nontumorigenic cells and, as such, it considerably expands the application space of biostabilized fluorescent AuNCs.

Estimation of genetic variability among peanut genotypes for resistance to leaf spot disease

This study aimed to identify high-yielding peanut genotypes with resistance to leaf spot disease. The experiments included material from fourteen local and four exotic peanut genotypes that showed highly significant differences among morphological and disease severity parameters in all the genotypes which, in turn, suggested diversity genotypes. Disease severity analysis showed that the highest disease score and damaged leaf area were observed in the genotype Kelincer and the lowest scores and leaf damaged areas were observed in Majalaya super and BARI-2000, respectively. Based on these results, the genotypes BARI-2011, Chakori, Golden, BARI-89, Majalaya Super, BARD-699, BARI-2000, SP-1, and No. 334 can be used by breeders in peanut improvement programs for the development of new cultivars with higher disease resistance and increased yield.

Relationship between circulating sex steroid hormone concentrations and incidence of total knee and hip arthroplasty due to osteoarthritis in men

OBJECTIVE

Few studies have examined the association between circulating sex steroid concentrations and risk of osteoarthritis (OA) in men with inconsistent results. Our aim was to examine whether concentrations of circulating sex steroid hormones were associated with the incidence of primary knee and hip arthroplasty for OA in a prospective cohort study.

DESIGN

Two thousand four hundred and ninety four men from the Melbourne Collaborative Cohort Study (MCCS) had circulating sex steroid concentrations measured in blood samples drawn at recruitment (1990-1994) and stored in liquid nitrogen. The plasma concentrations of sex hormones, including dehydroepiandrosterone sulphate, androstenedione, testosterone, estradiol, androstanediol glucuronide, and sex hormone binding globulin, were measured. The incidence of total knee and hip arthroplasty for OA during 2001-2013 was determined by linking MCCS records to the Australian Orthopaedic Association National Joint Replacement Registry.

RESULTS

One hundred and four men had knee and 80 had hip arthroplasty for OA over 10.7 (SD 3.8) years. Higher concentrations of androstenedione were associated with a decreased risk of total knee (hazard ratio (HR) 0.87, 95% confidence interval (CI) 0.77-0.98) and hip (HR 0.84 95% CI 0.71-1.00) arthroplasty for OA in overweight and obese men. No significant association was observed for the other measured hormones.

CONCLUSION

Low plasma androstenedione concentration is associated with an increased risk of both knee and hip arthroplasty for OA for overweight and obese men. While the findings need to be confirmed in other cohort studies, they suggest that circulating sex steroids may play a role in the pathogenesis of OA in men.

Knee osteoarthritis: a review of management options

Osteoarthritis of the knee is a complex peripheral joint disorder with multiple risk factors. The molecular basis of osteoarthritis has been generally accepted; however, the exact pathogenesis is still not known. Management of patients with osteoarthritis involves a comprehensive history, thorough physical examination and appropriate radiological investigation. The relative slow progress in the disease allows a stepwise algorithmic approach in treatment. Non-surgical treatment involves patient education, lifestyle modification and the use of orthotic devises. These can be achieved in the community. Surgical options include joint sparing procedures such as arthroscopyando osteotomy or joint-replacing procedures. Joint-replacing procedures can be isolated to a single compartment such as patellofemoral arthroplasty or unicompartmental knee replacement or total knee arthroplasty. The key to a successful long-term outcome is optimal patient selection, preoperative counselling and good surgical technique.

Intracellular accumulation and dissolution of silver nanoparticles in L-929 fibroblast cells using live cell time-lapse microscopy

Cytotoxicity assessments of nanomaterials, such as silver nanoparticles, are challenging due to interferences with test reagents and indicators as well uncertainties in dosing as a result of the complex nature of nanoparticle intracellular accumulation. Furthermore, current theories suggest that silver nanoparticle cytotoxicity is a result of silver nanoparticle dissolution and subsequent ion release. This study introduces a novel technique, nanoparticle associated cytotoxicity microscopy analysis (NACMA), which combines fluorescence microscopy detection using ethidium homodimer-1, a cell permeability marker that binds to DNA after a cell membrane is compromised (a classical dead-cell indicator dye), with live cell time-lapse microscopy and image analysis to simultaneously investigate silver nanoparticle accumulation and cytotoxicity in L-929 fibroblast cells. Results of this method are consistent with traditional methods of assessing cytotoxicity and nanoparticle accumulation. Studies conducted on 10, 50, 100 and 200 nm silver nanoparticles reveal size dependent cytotoxicity with particularly high cytotoxicity from 10 nm particles. In addition, NACMA results, when combined with transmission electron microscopy imaging, reveal direct evidence of intracellular silver ion dissolution and possible nanoparticle reformation within cells for all silver nanoparticle sizes.

Association between serum concentration of 25-hydroxyvitamin D and the risk of hip arthroplasty for osteoarthritis: result from a prospective cohort study

OBJECTIVES

There is ongoing debate regarding the optimal serum concentrations of 25-hydroxy-vitamin D for musculoskeletal health, including osteoarthritis (OA). The aim of this prospective cohort study was to determine whether serum 25-hydroxy-vitamin D concentrations were associated with the risk of hip arthroplasty for OA.

DESIGN

This study examined 9135 participants from the Australian Diabetes, Obesity and Lifestyle Study who had serum 25-hydroxy-vitamin D measured in 1999-2000 and were aged ≥40 years at the commencement of arthroplasty data collection. The incidence of hip arthroplasty for OA during 2002-2011 was determined by linking cohort records to the Australian Orthopaedic Association National Joint Replacement Registry.

RESULTS

Over an average 9.1 (standard deviation (SD) 2.7) years of follow-up, 201 hip arthroplasties for OA were identified (males n = 90; females n = 111). In males, a one-standard-deviation increase in 25-hydroxy-vitamin D was associated with a 25% increased incidence (HR 1.25, 95% CI 1.02-1.56), with a dose response relationship evident by quartiles of 25-hydroxy-vitamin D concentration (P for trend 0.04). These results were independent of age, body mass index (BMI), ethnicity, smoking status, physical activity, season of blood collection, latitude, hypertension and diabetes, area level disadvantage or after excluding those with extreme low 25-hydroxy-vitamin D concentrations. No significant association was observed in women (HR 1.10, 95% CI 0.87, 1.39).

CONCLUSIONS

Increasing serum 25-hydroxy-vitamin D concentrations were associated with an increased risk of hip arthroplasty for OA in males, while no significant association was observed in females. The mechanism for the association warrants further investigation.

Alemtuzumab induction and antibody-mediated rejection in kidney transplantation

BACKGROUND

Induction therapy improves graft outcomes in kidney transplant recipients (KTRs). We aimed to compare the incidences of antibody-mediated rejection (AMR) and acute cellular rejection (ACR) as well as graft and patient outcomes in KTRs who underwent induction with alemtuzumab versus rabbit-antithymocyte globulin (r-ATG).

METHODS

This was a single-center retrospective study involving patients who underwent kidney transplantation between January 2009 and December 2011 after receiving induction therapy with either alemtuzumab or r-ATG. Maintenance immunosuppression included tacrolimus and mycophenolate mofetil with early steroid withdrawal. Acute rejection was diagnosed using allograft biopsy.

RESULTS

Among the 108 study patients, 68 received alemtuzumab and 40 got r-ATG. There was a significantly higher incidence of AMR (15% vs 2.5%; P = .008) and similar incidence of ACR (4.4% vs 10%; P = .69) for alemtuzumab versus r-ATG groups. One-year serum creatinine levels (l.68 ± 0.8 mg/dL vs 1.79 ± 1.8 mg/dL; P = .66) as well as graft (91.1 ± 3.5% vs 94.5 ± 3.8%; P = .48) and patient (93.8 ± 3.0% vs 96.4 ± 3.5%; P = .92) survivals were similar for the alemtuzumab versus the r-ATG groups.

CONCLUSION

Our study showed a higher incidence of AMR and similar incidence of ACR in KTRs who underwent induction with alemtuzumab compared with those who received r-ATG and were maintained on tacrolimus and MMF. This was despite a lower HLA mismatch in the alemtuzumab group. One-year graft survival, patient survival, and allograft function were similar. Inadequate B-cell suppression by alemtuzumab as well as altered phenotypic and functional properties of repopulating B cells could be contributing to heightened risk of AMR in these patients.

The role of biological fluid and dynamic flow in the behavior and cellular interactions of gold nanoparticles

Background

Due to their distinctive physicochemical properties, nanoparticles (NPs) have proven to be extremely advantageous for product and application development, but are also capable of inducing detrimental outcomes in biological systems. Standard in vitro methodologies are currently the primary means for evaluating NP safety, as vast quantities of particles exist that require appraisal. However, cell-based models are plagued by the fact that they are not representative of complex physiological systems. The need for a more accurate exposure model is highlighted by the fact that NP behavior and subsequent bioresponses are highly dependent upon their surroundings. Therefore, standard in vitro models will likely produce inaccurate NP behavioral analyses and erroneous safety results. As such, the goal of this study was to develop an enhanced in vitro model for NP evaluation that retained the advantages of cell culture, but implemented the key physiological variables of accurate biological fluid and dynamic flow.

Results

In this study, a cellular microenvironment was modeled and created after an inhalation exposure scenario. This system comprised of A549 lung epithelial cells, artificial alveolar fluid (AAF), and biologically accurate dynamic flow. Under the influence of microenvironment variables, tannic acid coated gold NPs (AuNPs) displayed modulated physicochemical characteristics, including increased agglomeration, disruption of the spectral signature, and decreased rate of ionic dissolution. Furthermore, AuNP deposition efficiency, internalization patterns, and the nano-cellular interface varied as a function of fluid composition and flow condition. AAF incubation simultaneously influenced both AuNPs and cellular behavior, through excessive NP agglomeration and alteration to A549 morphology. Dynamic flow targeted the nano-cellular interface, with differential responses including modified deposition, internalization patterns, and cellular elongation. Lastly, the biocompatibility of the system was verified to ensure cellular health following AAF exposure and fluid dynamics.

Conclusions

This study confirmed the feasibility of improving standard in vitro models through the incorporation of physiological variables. Utilization of this enhanced system demonstrated that to elucidate true NP behavior and accurately gauge their cellular interactions, assessments should be carried out in a more complex and relevant biological exposure model.

Electronic supplementary material

The online version of this article (doi:10.1186/s12951-015-0117-1) contains supplementary material, which is available to authorized users.

Retinal arteriolar narrowing and incidence of knee replacement for osteoarthritis: a prospective cohort study

OBJECTIVES

The role of the microcirculation in the pathogenesis of osteoarthritis (OA) remains unclear. This prospective cohort study examined the association between retinal vascular calibre and incidence of knee replacement for OA.

DESIGN

1838 participants of the Australian Diabetes, Obesity and Lifestyle (AusDiab) Study had retinal vascular calibre measured using a nonmydriatic digital fundus camera in 1999-2000 and were aged ≥ 40 years at joint replacement data collection commencement. The incidence of knee replacement for OA during 2002-2011 was determined by linking cohort records to the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR).

RESULTS

77 participants underwent knee replacement for OA. They had narrower retinal arteriolar calibre compared with those without knee replacement (166.1 ± 24.8 μm vs 174.3 ± 24.5 μm, P = 0.004). For every one standard deviation reduction in retinal arteriolar calibre, the incidence of knee replacement increased by 25% (HR 1.25, 95% confidence interval (CI) 1.00-1.56). Participants in the narrower two-thirds of arteriolar calibre had twice the risk of knee replacement compared with those in the widest one-third (HR 2.00, 95% CI 1.07-3.74, P = 0.03) after adjustment for sex, body mass index (BMI), physical activity and HbA1c. There was no association for retinal venular calibre.

CONCLUSIONS

Retinal arteriolar narrowing is associated with increased risk of knee replacement for OA suggesting that further work is warranted to determine the role of the microcirculation in the pathogenesis of knee OA.

Assessment of Carbon- and Metal-Based Nanoparticle DNA Damage with Microfluidic Electrophoretic Separation Technology

In this study, we examined the feasibility of extracting DNA from whole cell lysates exposed to nanoparticles using two different methodologies for evaluation of fragmentation with microfluidic electrophoretic separation. Human lung macrophages were exposed to five different carbon- and metal-based nanoparticles at two different time points (2 h, 24 h) and two different doses (5 µg/ml, 100 µg/ml). The primary difference in the banding patterns after 2 h of nanoparticle exposure is more DNA fragmentation at the higher NP concentration when examining cells exposed to nanoparticles of the same composition. However, higher doses of carbon and silver nanoparticles at both short and long dosing periods can contribute to erroneous or incomplete data with this technique. Also comparing DNA isolation methodologies, we recommend the centrifugation extraction technique, which provides more consistent banding patterns in the control samples compared to the spooling technique. Here we demonstrate that multi-walled carbon nanotubes, 15 nm silver nanoparticles and the positive control cadmium oxide cause similar DNA fragmentation at the short time point of 2 h with the centrifugation extraction technique. Therefore, the results of these studies contribute to elucidating the relationship between nanoparticle physicochemical properties and DNA fragmentation results while providing the pros and cons of altering the DNA isolation methodology. Overall, this technique provides a high throughput way to analyze subcellular alterations in DNA profiles of cells exposed to nanomaterials to aid in understanding the consequences of exposure and mechanistic effects. Future studies in microfluidic electrophoretic separation technologies should be investigated to determine the utility of protein or other assays applicable to cellular systems exposed to nanoparticles.

Dynamic characteristics of silver nanoparticles in physiological fluids: toxicological implications

The field of nanotoxicology has made tremendous progress identifying novel and potentially adverse biological effects following nanomaterial (NM) exposure. However, one facet yet to be satisfactorily explored is how a physiological environment modifies NM physicochemical properties, thus introducing novel complexities associated with solid phase material exposures. In this study, artificial alveolar, lysosomal, and interstitial fluids were used to identify environmental-specific modulations to the properties and behavior of hydrocarbon-coated (Ag-HC) and polysaccharide-coated (Ag-PS) silver NMs. As inhalation is a common route of exposure, an alveolar macrophage cell model with deposition dosages representing approximately 2.5 months and 10 years of occupational exposure (0.5 and 25 ng/mL, respectively) were employed. Following dispersion in the artificial fluids, the Ag-HC and Ag-PS NMs demonstrated significant alterations to morphology, aggregation patterns, and particle reactivity. However, the Ag-PS also demonstrated a loss of particle coating, which elicited increased cytotoxicity, phagocytosis, and inflammation not associated with the original Ag-PS. This study demonstrated that in a physiological system NMs undergo considerable modulation, introducing a scenario where the toxicity of NMs may increase over time due to internal bioconditions. These findings highlight the critical influence that the dynamic and insoluble nature of NMs have on bioeffects and the importance of characterizing this behavior.

Slow release of ions from internalized silver nanoparticles modifies the epidermal growth factor signaling response

Due to their distinctive physiochemical properties, including a robust antibacterial activity and plasmonic capability, hundreds of consumer and medical products contain colloidal silver nanoparticles (AgNPs). However, even at sub-toxic dosages, AgNPs are able to disrupt cell functionality, through a yet unknown mechanism. Moreover, internalized AgNPs have the potential to prolong this disruption, even after the removal of excess particles. In the present study, we evaluated the impact, mechanism of action, and continual effects of 50 nm AgNP exposure on epidermal growth factor (EGF) signal transduction within a human keratinocyte (HaCaT) cell line. After AgNP expose, EGF signaling was initially obstructed due to the dissolution of particles into silver ions. However, at longer durations, the internalized AgNPs increased EGF signaling activity. This latter behavior correlated to sustained HaCaT stress, believed to be maintained through the continual dissolution of internalized AgNPs. This study raises concerns that even after exposure ceases, the retained nanomaterials are capable of acting as a slow-release mechanism for metallic ions; continually stressing and modifying normal cellular functionality.

Protein coronas on gold nanorods passivated with amphiphilic ligands affect cytotoxicity and cellular response to penicillin/streptomycin

We probe how amphiphilic ligands (ALs) of four different types affect the formation of protein coronas on gold nanorods (NRs) and their impact on cellular response. NRs coated with cetyltrimethylammonium bromide were ligand exchanged with polyoxyethylene[10]cetyl ether, oligofectamine, and phosphatidylserine (PS). Protein coronas from equine serum (ES) were formed on these NR-ALs, and their colloidal stability, as well as cell uptake, proliferation, oxidative stress, and gene expression, were examined. We find that the protein corona that forms and its colloidal stability are affected by AL type and that the cellular response to these NR-AL-coronas (NR-AL-ES) is both ligand and corona dependent. We also find that the presence of common cell culture supplement penicillin/streptomycin can impact the colloidal stability and cellular response of NR-AL and NR-AL-ES, showing that the cell response is not necessarily inert to pen/strep when in the presence of nanoparticles. Although the protein corona is what the cells see, the underlying surface ligands evidently play an important role in shaping and defining the physical characteristics of the corona, which ultimately impacts the cellular response. Further, the results of this study suggest that the cellular behavior toward NR-AL is mediated by not only the type of AL and the protein corona it forms but also its resulting colloidal stability and interaction with cell culture supplements.

Less is more: long-term in vitro exposure to low levels of silver nanoparticles provides new insights for nanomaterial evaluation

In view of the vast number of new nanomaterials (NMs) that require testing and the constraints associated with animal models, the majority of studies to elucidate nanotoxicological effects have occurred in vitro, with limited correlation and applicability to in vivo systems and realistic, occupational exposure scenarios. In this study, we developed and implemented a chronic in vitro model coupled with lower, regulatory dosages in order to provide a more realistic assessment of NM-dependent consequences and illuminate the implications of long-term NM exposure. When keratinocytes were exposed to 50 nm silver nanoparticles (Ag-NPs), we determined that chronically dosed cells operated under augmented stress and modified functionality in comparison to their acute counterparts. Specifically, Ag-NP exposure through a chronic mechanism increased p38 activation, actin disorganization, heightened ki67 expression, and extensive gene modification. Additionally, chronic Ag-NP exposure altered the way in which cells perceived and responded to epidermal growth factor stimulation, indicating a transformation of cell functionality. Most importantly, this study demonstrated that chronic exposure in the pg/mL range to Ag-NPs did not induce a cytotoxic response, but instead activated sustained stress and signaling responses, suggesting that cells are able to cope with prolonged, low levels of Ag-NP exposure. In summary, we demonstrated that through implementation of a chronic dosimetry paradigm, which more closely resembles realistic NM exposure scenarios, it is possible to illuminate long-term cellular consequences, which greatly differ from previously obtained acute assessments.