Magnetic field effects on the surfactant concentration over ferrofluid droplet surfaces in shear flows

We investigate the impact of a magnetic field on surfactant concentration and interfacial forces across droplet surfaces within shear flows. Our analysis centers on a single two-dimensional ferrofluid droplet covered with surfactants, suspended in an immiscible, non-magnetizable liquid. The model combines incompressible Navier-Stokes equations and Maxwell's equations in the superparamagnetic limit in the single-fluid formulation, augmented by terms accounting for Marangoni, capillary, and magnetic forces at the droplet interface. We solve the surfactant convection-diffusion equation at the surface, while a non-linear Langmuir equation of state relates surfactant concentration to surface tension. The model is numerically solved using finite differences, a level-set method for multiphase flow computation, and the closest-point method for concentration equation. Our findings reveal that even though the surfactant is magnetically neutral, the presence of a magnetic field significantly modifies its distribution at the interface. A magnetic field perpendicular to the primary flow direction shifts the maximum concentration zone from the droplet tips toward the flow vorticity direction, while a parallel field produces the opposite effect. Alterations in surfactant distribution directly impact the surface tension field, offering a potential wireless means of controlling droplet dynamics.

Endotoxin tolerance and low activation of TLR-4/NF-κB axis in monocytes of COVID-19 patients

Higher endotoxin in the circulation may indicate a compromised state of host immune response against coinfections in severe COVID-19 patients. We evaluated the inflammatory response of monocytes from COVID-19 patients after lipopolysaccharide (LPS) challenge. Whole blood samples of healthy controls, patients with mild COVID-19, and patients with severe COVID-19 were incubated with LPS for 2 h. Severe COVID-19 patients presented higher LPS and sCD14 levels in the plasma than healthy controls and mild COVID-19 patients. In non-stimulated in vitro condition, severe COVID-19 patients presented higher inflammatory cytokines and PGE-2 levels and CD14 + HLA-DR^low monocytes frequency than controls. Moreover, severe COVID-19 patients presented higher NF-κB p65 phosphorylation in CD14 + HLA-DR^low, as well as higher expression of TLR-4 and NF-κB p65 phosphorylation in CD14 + HLA-DR^high compared to controls. The stimulation of LPS in whole blood of severe COVID-19 patients leads to lower cytokine production but higher PGE-2 levels compared to controls. Endotoxin challenge with both concentrations reduced the frequency of CD14 + HLA-DR^low in severe COVID-19 patients, but the increases in TLR-4 expression and NF-κB p65 phosphorylation were more pronounced in both CD14 + monocytes of healthy controls and mild COVID-19 patients compared to severe COVID-19 group. We conclude that acute SARS-CoV-2 infection is associated with diminished endotoxin response in monocytes. KEY MESSAGES: Severe COVID-19 patients had higher levels of LPS and systemic IL-6 and TNF-α. Severe COVID-19 patients presented higher CD14+HLA-DRlow monocytes. Increased TLR-4/NF-κB axis was identified in monocytes of severe COVID-19. Blunted production of cytokines after whole blood LPS stimulation in severe COVID-19. Lower TLR-4/NF-κB activation in monocytes after LPS stimulation in severe COVID-19.

Alterations in CD39/CD73 axis of T cells associated with COVID-19 severity

Purinergic signaling modulates immune function and is involved in the immunopathogenesis of several viral infections. This study aimed to investigate alterations in purinergic pathways in coronavirus disease 2019 (COVID‐19) patients. Mild and severe COVID‐19 patients had lower extracellular adenosine triphosphate and adenosine levels, and higher cytokines than healthy controls. Mild COVID‐19 patients presented lower frequencies of CD4⁺CD25⁺CD39⁺ (activated/memory regulatory T cell [mTreg]) and increased frequencies of high‐differentiated (CD27⁻CD28⁻) CD8⁺ T cells compared with healthy controls. Severe COVID‐19 patients also showed higher frequencies of CD4⁺CD39⁺, CD4⁺CD25⁻CD39⁺ (memory T effector cell), and high‐differentiated CD8⁺ T cells (CD27⁻CD28⁻), and diminished frequencies of CD4⁺CD73⁺, CD4⁺CD25⁺CD39⁺ mTreg cell, CD8⁺CD73⁺, and low‐differentiated CD8⁺ T cells (CD27⁺CD28⁺) in the blood in relation to mild COVID‐19 patients and controls. Moreover, severe COVID‐19 patients presented higher expression of PD‐1 on low‐differentiated CD8⁺ T cells. Both severe and mild COVID‐19 patients presented higher frequencies of CD4⁺Annexin‐V⁺ and CD8⁺Annexin‐V⁺ T cells, indicating increased T‐cell apoptosis. Plasma samples collected from severe COVID‐19 patients were able to decrease the expression of CD73 on CD4⁺ and CD8⁺ T cells of a healthy donor. Interestingly, the in vitro incubation of peripheral blood mononuclear cell from severe COVID‐19 patients with adenosine reduced the nuclear factor‐κB activation in T cells and monocytes. Together, these data add new knowledge to the COVID‐19 immunopathology through purinergic regulation.

Genome-wide promoter methylation profiling in a cellular model of melanoma progression reveals markers of malignancy and metastasis that predict melanoma survival

The epigenetic changes associated with melanoma progression to advanced and metastatic stages are still poorly understood. To shed light on the CpG methylation dynamics during melanoma development, we analyzed the methylome profiles of a four-stage cell line model of melanoma progression: non-tumorigenic melanocytes (melan-a), premalignant melanocytes (4C), non-metastatic melanoma cells (4C11−), and metastatic melanoma cells (4C11+). We identified 540 hypo- and 37 hypermethylated gene promoters that together characterized a malignancy signature, and 646 hypo- and 520 hypermethylated promoters that distinguished a metastasis signature. Differentially methylated genes from these signatures were correlated with overall survival using TCGA-SKCM methylation data. Moreover, multivariate Cox analyses with LASSO regularization identified panels of 33 and 31 CpGs, respectively, from the malignancy and metastasis signatures that predicted poor survival. We found a concordant relationship between DNA methylation and transcriptional levels for genes from the malignancy (Pyroxd2 and Ptgfrn) and metastasis (Arnt2, Igfbp4 and Ptprf) signatures, which were both also correlated with melanoma prognosis. Altogether, this study reveals novel CpGs methylation markers associated with malignancy and metastasis that collectively could improve the survival prediction of melanoma patients.

Mass spectrometry determination of seized oil-based anabolic-androgenic steroids products

INTRODUCTION

The presence of anabolic-androgenic steroids (AAS) in illegal commercial products has been pointed as a global threat for public health. Due the correlation with adverse toxicological effects, there is a growing interest in the implementation of straightforward methods for the determination of AAS in seized products. This work exploited the development of a mass spectrometry approach to characterize the illegal oil formulations containing AAS.

METHODS

The optimization of sample preparation was performed through a simplex-centroid design and the best condition was described as follow: an aliquot of 5 μL of sample were added with 995 μL of acetonitrile and water (75:25, v/v). The solution was vortexed and centrifuged. After that, 10 μL of supernatant were added with 35 μL of acetonitrile and water and internal standard (testosterone-d₃, 1.25 ng). An aliquot of 5 μL was injected into the analytical system.

RESULTS

The method developed was validated and successfully applied in 115 seized samples. Testosterone and its esters had the highest incidence, found in more than 50% of the samples. Besides that, drugs such as boldenone, methandienone, and trenbolone have also been found, where the low quality of the samples was evidenced by the wide variation in the concentration of the drugs, always quantified in sub-doses. Finally, at least one AAS was detected in each sample analyzed. The statistical results were grouped by principal components analysis, to better understand the profile of the seized samples.

CONCLUSION

This work successfully established a fast and simple method for determination of AAS and can be applied to verify the profile of seized samples.

Increased LPS levels coexist with systemic inflammation and result in monocyte activation in severe COVID-19 patients

Mucosal barrier alterations may play a role in the pathogenesis of several diseases, including COVID-19. In this study we evaluate the association between bacterial translocation markers and systemic inflammation at the earliest time-point after hospitalization and at the last 72 h of hospitalization in survivors and non-survivors COVID-19 patients. Sixty-six SARS-CoV-2 RT-PCR positive patients and nine non-COVID-19 pneumonia controls were admitted in this study. Blood samples were collected at hospital admission (T1) (Controls and COVID-19 patients) and 0-72 h before hospital discharge (T2, alive or dead) to analyze systemic cytokines and chemokines, lipopolysaccharide (LPS) concentrations and soluble CD14 (sCD14) levels. THP-1 human monocytic cell line was incubated with plasma from survivors and non-survivors COVID-19 patients and their phenotype, activation status, TLR4, and chemokine receptors were analyzed by flow cytometry. COVID-19 patients presented higher IL-6, IFN-γ, TNF-α, TGF-β1, CCL2/MCP-1, CCL4/MIP-1β, and CCL5/RANTES levels than controls. Moreover, LPS and sCD14 were higher at hospital admission in SARS-CoV-2-infected patients. Non-survivors COVID-19 patients had increased LPS levels concomitant with higher IL-6, TNF-α, CCL2/MCP-1, and CCL5/RANTES levels at T2. Increased expression of CD16 and CCR5 were identified in THP-1 cells incubated with the plasma of survivor patients obtained at T2. The incubation of THP-1 with T2 plasma of non-survivors COVID-19 leads to higher TLR4, CCR2, CCR5, CCR7, and CD69 expression. In conclusion, the coexistence of increased microbial translocation and hyperinflammation in patients with severe COVID-19 may lead to higher monocyte activation, which may be associated with worsening outcomes, such as death.

Accidental ingestion of methyl ethyl ketone peroxide: N-acetylcysteine treatment and toxicological analysis

INTRODUCTION

Methyl ethyl ketone peroxide (MEKP) is a highly toxic product which promotes tissue damage by uncontrolled free radical production.

CASE REPORT

A man accidentally ingested 110 ml of MEKP (37%) at his workplace after mistaking it with a bottle of water. A loading dose of N-acetylcysteine (NAC) and subsequent maintenance doses were applied at the hospital for three consecutive days. Biochemical and hematological parameters showed significant alterations. Tracheal intubation, gastric lavage and hemodialysis were not performed. Methyl ethyl ketone (MEK) and MEKP were detected in EDTA-blood samples by GC-FID and LC-QTOF/MS respectively. An endoscopy exam identified tissue damage. The patient was admitted to the hospital for 10 days. No sequelae were reported after the MEKP poisoning. Oral administration of NAC was successful as an antidote without another approach.

CONCLUSIONS

Although NAC treatment was successful, supervision after the hospitalization period was required according to the prognosis. Workplace conditions promoted anosmia, explaining the accident. MEKP and MEK were successfully detected in blood samples even with less-than-ideal storage conditions. Knowledge of MEKP dangerousness and good work practices can prevent accidental MEKP poisoning.

P4132Decreased myocardial native T1 times and impaired myocardial contractility in young anabolic androgenic steroids users

Background

Anabolic androgenic steroids (AAS) have been associated with several injuries on the cardiovascular system. AAS abuse may have a direct toxic effect on the myocardium that could lead to cardiac function and structure alterations. Clinical and forensic cases have been reported myocardial fibrosis in AAS users. Myocardial fibrosis increases the risk of heart failure and sudden death. However, recent studies did not show evidence of focal myocardial fibrosis and diffuse myocardial fibrosis in AAS users using T1-mapping techniques. Thus, it remains unclear the association between AAS and cardiac structure alterations.

Purpose

The aim of this study was to evaluate cardiac structure by cardiovascular magnetic resonance (CMR) imaging with late-gadolinium enhancement (LGE), cardiac T1-mapping and extracellular volume measurements (ECV). Additionally, we also evaluated the cardiac contractility by CMR and echocardiography in young AAS users.

Methods

Twenty strength-trained AAS users (AASU) age 29±5 yr, 20 age-matched strength-trained AAS nonusers (AASNU), and 10 sedentary controls (SC) were enrolled. Cardiac structure was assessed by LGE, native T1-mapping and ECV. Cardiac contractility was evaluated as cardiac strain measured by CMR (feature tracking imaging technique) and echocardiography (speckle tracking technique).

Results

Global native T1 times [753 (683–870) vs 916 (815–1239) vs 1205 (825–1242) ms, respectively, p=0.03], and native T1 times at the left ventricle mid-ventricular slice [813 (695–1096) vs 922 (825–1095) vs 1140 (840–1322) ms, respectively, p=0.03] were lower in AASU compared with AASNU and SC. Mid-ventricular ECV was similar between AASU, AASNU and SC (22±6 vs 23±4 vs 24±4%, respectively, p=0.37). Focal myocardial fibrosis was found in 2 individuals (11%) of AASU. The mid anteroseptal and mid inferoseptal were the most affected segments. The total estimated mass of the LV mass was 1.25 g (0.65%). Three participants of SC showed focal myocardial fibrosis. The mid anterolateral, mid inferolateral and mid inferomedial were the most affected segments. The total estimated mass of the LV mass was 3.43 g (2.30%). In contrast, none of the AASNU had myocardial fibrosis. By CMR, AASU showed a lower medial radial strain (30±8 vs. 38±6%, p<0.01), medial circumferential strain (−17±3 vs −20±2%, p<0.01) and global longitudinal strain (−17±3 vs −20±3%, p<0.01) compared with AASNU. Echocardiography also demonstrated a lower 4CH longitudinal strain in AASU compared with AASNU (−15.5±3 vs −18.3±2%, p=0.03). Moreover, the AASU shower a higher left ventricle mass compared with AASNU and SC (185±20 vs 130±17 vs 112±14 g, respectively, p<0.01).

Conclusion

This study indicates that AAS abuse may be associated with decreased myocardial native T1 times, impaired myocardial contractility and focal myocardial fibrosis. These myocardial structural and functional alterations may be associated to unadapted cardiac hypertrophy in young AAS users.

Acknowledgement/Funding

Fundação de Amparo à Pesquisa do Estado de São Paulo [FAPESP], Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (Capes).

The redox balance of healthy Brazilian adults is associated with GPX1 Pro198Leu and -602A/G polymorphisms, selenium status, and anthropometric and lifestyle parameters

PURPOSE

Considering that oxidative stress is implicated in the pathogenesis and progression of different health conditions, we aimed to evaluate whether the redox balance of a healthy Brazilian population is associated with GPX1 polymorphisms, selenium status, lipid profile, and anthropometric and lifestyle parameters.

METHODS

343 healthy adults were assessed for redox balance markers [glutathione peroxidase (GPx) and superoxide dismutase (SOD) activity; malondialdehyde (MDA) and oxygen radical absorption capacity (ORAC)]; genotyped for the polymorphisms GPX1 Pro198Leu (rs1050450), -602A/G (rs3811699) and Arg5Pro (rs8179169); evaluated for selenium biomarkers (plasma, erythrocyte, and urine) and intake; and assessed for lipid profile. Anthropometric (BMI) and lifestyle data (physical activity, current smoking habit and alcohol consumption) were collected. Multivariable regression models were applied to investigate the possible associations.

RESULTS

Although there were no differences in GPx activity according to GPX1 Pro198Leu and -602A/G polymorphisms, this redox balance marker was positively associated with erythrocyte selenium and negatively associated with the presence of a minor allele of Pro198Leu. SOD activity was positively associated with the presence of a minor allele for these polymorphisms. ORAC showed the same pattern among Leu and G carriers and was positively associated with Leu allele presence, BMI and alcohol intake. MDA was only associated negatively with the male sex and plasma selenium.

CONCLUSIONS

Our findings suggest that the redox balance of a Brazilian healthy population is associated with GPX1 polymorphisms (Pro198Leu and -602A/G), selenium status, BMI, sex, smoking habit and alcohol consumption.

Chronic Cadmium Exposure Accelerates the Development of Atherosclerosis and Induces Vascular Dysfunction in the Aorta of ApoE-/- Mice

Cadmium exposure is related to cardiovascular diseases, including hypertension, atherosclerosis, increased oxidative stress, endothelial dysfunction, and specific biochemical changes induced by this metal. Thus, we aimed to investigate whether cadmium exposure induces endothelial dysfunction, accelerates atherosclerotic plaque formation in the aorta, and enhances oxidative stress in apolipoprotein E knockout (ApoE^-/-) mice. Experiments were performed in 14-week-old male wild-type and ApoE^-/- mice. ApoE^-/- mice received cadmium (CdCl₂ 100 mg/L in drinking water for 28 days) or vehicle (distilled water). After treatment, vascular reactivity to phenylephrine, acetylcholine, and sodium nitroprusside was analyzed using isolated aorta. Bone marrow cells were isolated to assess the production of nitric oxide and reactive oxygen and nitrogen species. ApoE^-/- cadmium-treated mice had higher cholesterol levels than non-exposed mice. Cadmium exposure decreased the vasodilatation response to acetylcholine in aortic ring of ApoE^-/- mice, though no changes in phenylephrine or sodium nitroprusside responses were observed. L-NAME reduced vasodilator responses to acetylcholine; this effect was lower in ApoE^-/- cadmium-treated mice, suggesting reduction in nitric oxide (NO) bioavailability. Moreover, in bone marrow cells, cadmium decreased cytoplasmic levels of NO and increased superoxide anions, hydrogen peroxide, and peroxynitrite in ApoE^-/- mice. Morphological analysis showed that cadmium exposure increased plaque deposition in the aorta by approximately 3-fold. Our results suggest that cadmium exposure induces endothelial dysfunction in ApoE^-/- mice. Moreover, cadmium increased total cholesterol levels, which may promote the early development of atherosclerosis in the aorta of ApoE^-/- mice. Our findings support the hypothesis that cadmium exposure might increase the risk of atherosclerosis.

Abstract 192: Exposure to high saturated fat acid diet in early life changes the susceptibility to breast cancer in adulthood

Nutrition is thought to be involved in 30 to 50% of all breast cancer and intake of animal fat seems to be related to the increase of this type of cancer. It has been suggested that breast cancer can originate in early life, including the in utero and lactation periods. Maternal nutrition can modify the fetal environment and induce epigenetics modifications that change the susceptibility of offspring to breast cancer in adulthood. We hypothesized that exposure to high saturated fatty acid diet (HFS) in early life can change gene expression through the remodeling of epigenetic marks and consequently modify the risk of breast cancer. Sprague-Dawley rats were used in our study, which was composed of three groups: CO (female rats exposed to control diet [AIN-93G] in utero and lactation); PG (female rats exposed to HSF in utero) and PL (female rats exposed to HSF in utero and lactation). The distribution of fatty acid in the HSF was 37%, 38% and 24% of saturated, monounsaturated and polyunsaturated, respectively while in the CO diet, the distribution of those fatty acid was 17%, 27% and 55%, respectively. Female rats were euthanized on post-natal day (PND) 50 and blood and mammary tissue collected. Serum samples were assayed for estradiol, progesterone and leptin levels (radioimmunoassay and immunofluorescence). Mammary glands were evaluated for the number of terminal End Buds (TEBs), global DNA methylation (HPLC-DAD) and global histone modification patterns (western blot). Mammary tumor development induced by oral administration of dimethylbenz[a]anthracene (DMBA) on PND50 was also evaluated. Global DNA methylation were also determined in mammary tumors. There were no differences (P&gt;0.05) in maternal caloric intake, offspring birth weight, serum estradiol levels or number of TEBs among the groups. Serum progesterone levels showed a tendency to increase (P=0.07) in the PG group compared to CO group. Compared to others groups, the PL group showed higher (P≤0.05) serum leptin levels. The PG group showed higher levels (P≤0.05) of global trimethylation of histone 3 lysine 9 (H3K9me3) compared to CO group, but no differences were observed (P&gt;0.05) for global DNA methylation and global H3K9/H4K16 acetylation and H3K27/H3K4 trimethylation. The PG group showed lower incidence (P≤0.05) and average number of tumors compared to CO group and higher latency (P≤0.05) compared to PL group. The tumors from PG group presented lower (P≤0.05) global DNA methylation compared to others groups. In conclusion, exposure to HSF in early life influenced the susceptibility of breast cancer in adulthood. But, differently from what we expected the exposure to this diet in utero decreased breast cancer risk. If this exposure is continued through the period of lactation the protective effect is lost. This modification of breast cancer risk in early life seems to involve epigenetics mechanisms like post-translational histone modification.

Citation Format: Fábia O. Andrade, Camile C. Fontelles, Mariana Rosim, Tiago F. Oliveira, Ana PM Loureiro, Marcelo M. Rogero, Fernando S. Moreno, Sonia M. De Assis, Leena Hilakivi-Clarke, Luis F. Barbisan, Thomas P. Ong. Exposure to high saturated fat acid diet in early life changes the susceptibility to breast cancer in adulthood. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 192. doi:10.1158/1538-7445.AM2013-192

Alterations in morphometric and organosomatic indices and histopathological analyses indicative of environmental contamination in Mullet, Mugil liza, from Southeastern Brazil

Mullet (Mugil liza) were sampled in five different areas along the Guanabara Bay, southeastern Brazil, classified as non-contaminated, moderately contaminated and contaminated. Morphometric (Fulton condition factor, relative condition factor and weight to length scaling coefficient) and organosomatic (hepatosomatic index) indices of environmental stress were analysed. Fish from the differentially contaminated areas show statistically different Fulton and relative condition factors and hepatosomatic indices, but not the weight to length scaling coefficient. The Kn and the FCF followed the same trend, with fish from São Gonçalo (1.07 ± 0.04 and 0.89 ± 0.03), Itaipu (0.84 ± 0.01 and 0.86 ± 0.01) and the Rodrigo de Freitas Lagoon (1.03 ± 0.01 and 0.87 ± 0.20) showing higher FCFs than fish from Magé (0.96 ± 0.01 and 0.81 ± 0.01). Fish from Itaipu showed significantly higher HSI values than the other sampling sites (1.68 ± 0.07), with fish from Olaria and Ipiranga showing the lowest (1.56 ± 0.12 and 1.60 ± 0.07, respectively).

Inefficacy of piracetam in the prevention of painful crises in children and adolescents with sickle cell disease

Analgesia and hydration remain the only safe treatment for painful crises of sickle cell disease; hydroxyurea is effective, but the toxicity is still a problem. Piracetam is a nootropic drug that has reportedly been effective and non-toxic in sickle cell patients, but most studies were not placebo-controlled and included a small number of patients. The present study evaluated the drug in a double-blind crossed placebo-controlled clinical trial in 73 children and adolescents suffering from moderate to severe painful crises for 13 months. Information regarding frequency and severity of pain was acquired through monthly clinical evaluation, visits and house calls, and 4,300 weekly questionnaires filled out by the patients in their domiciles. A monthly pain score was calculated for each patient. Pain was the most frequent adverse manifestation of the disease stressing its significant bio-psycho-social impact. Although nearly all patients and relatives reported a better clinical course throughout the whole study, the drug was ineffective in the prevention of painful crises. This placebo effect may be ascribed to an unplanned and unsystematic 'cognitive-behavioural' management of the children. The pain score in the second semester of the study - both in the experimental and in the control groups - was significantly smaller than that in the first semester. In conclusion, piracetam was found to be ineffective in the prevention of painful crises; a powerful placebo effect due to adequate patient care was demonstrated.