Process evaluation of a university residence-based SARS-CoV-2 testing programme in the UK

Background

Regular testing for SARS-CoV-2 is an important strategy for controlling virus outbreaks on university campuses during the COVID-19 pandemic but testing participation can be low. The Residence-Based Testing Participation Pilot (RB-TPP) was a novel 4-week intervention implemented at two student residences on a UK university campus, aiming to increase asymptomatic testing frequency and normalise university life through relaxed social restrictions onsite.

Methods

Mixed-methods process evaluation determined whether RB-TPP was implemented as planned and identified implementation barriers and facilitators. Data were collected from meeting records, university students (online survey: n = 152; focus groups: n = 30), and staff (interviews, n = 13). Barriers and facilitators to implementation were mapped to the ‘Capability, Opportunity, Motivation-Behaviour’ (COM-B) behaviour change framework.

Results

Uptake was high (n = 464 students opted-in; 98% of those living onsite). Implementation was broadly as planned, with adjustments due to national escalation of the COVID-19 Delta variant. Majority engaged in testing (88%); 46% (52% of testers) were fully compliant with pre-determined testing frequency. Most felt positively towards relaxed social distancing (97.9%). Implementation was facilitated by convenience and efficiency of testing and reduced negative impacts of isolation through opportunities for students to socialise. Barriers to implementation were mixed-messages about the rules, ambivalent attitudes, and lack of adherence to COVID-19 protective measures in the minority.

Conclusions

This is the first process evaluation of the implementation of asymptomatic SARS-CoV-2 testing in university residences. Testing participation increased and student mental wellbeing improved. Rapid adaptions to the changing pandemic context generated complexity and challenge. Findings have global relevance for outbreak prevention and management strategies in higher education settings.

Key messages

• Delivery of asymptomatic SARS-CoV-2 testing and relaxation of social distancing within residences led to high rates of testing participation and benefits for student mental wellbeing.

• This is the first process evaluation of the implementation of asymptomatic SARS-CoV-2 testing in university residences with global relevance for outbreak prevention in higher education settings.

Mixed-methods process evaluation of a residence-based SARS-CoV-2 testing participation pilot on a UK university campus during the COVID-19 pandemic

BACKGROUND

Regular testing for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is an important strategy for controlling virus outbreaks on university campuses during the COVID-19 pandemic but testing participation rates can be low. The Residence-Based Testing Participation Pilot (RB-TPP) was a novel intervention implemented at two student residences on a large UK university campus over 4 weeks. The aim of the pilot was to increase the frequency of asymptomatic SARS-CoV-2 saliva testing onsite. This process evaluation aimed to determine whether RB-TPP was implemented as planned and identify implementation barriers and facilitators.

METHODS

A mixed-methods process evaluation was conducted alongside the RB-TPP. Evaluation participants were students (opting in, or out of RB-TPP) and staff with a role in service provision or student support. Monitoring data were collected from the intervention delivery team and meeting records. Data were collected from students via online survey (n = 152) and seven focus groups (n = 30), and from staff via individual interviews (n = 13). Quantitative data were analysed descriptively and qualitative data thematically. Barriers and facilitators to implementation were mapped to the 'Capability, Opportunity, Motivation-Behaviour' (COM-B) behaviour change framework.

RESULTS

Four hundred sixty-four students opted to participate in RB-TPP (98% of students living onsite). RB-TPP was implemented broadly as planned but relaxed social distancing was terminated early due to concerns relating to national escalation of the COVID-19 Delta variant, albeit testing continued. Most students (97.9%) perceived the period of relaxed social distancing within residences positively. The majority engaged in asymptomatic testing (88%); 46% (52% of testers) were fully compliant with pre-determined testing frequency. Implementation was facilitated by convenience and efficiency of testing, and reduction in the negative impacts of isolation through opportunities for students to socialise. Main barriers to implementation were perceived mixed-messages about the rules, ambivalent attitudes, and lack of adherence to COVID-19 protective measures in the minority.

CONCLUSIONS

This process evaluation identifies factors that help or hinder the success of university residence-based outbreak prevention and management strategies. RB-TPP led to increased rates of SARS-CoV-2 testing participation among students in university residences. Perceived normalisation of university life significantly enhanced student mental wellbeing. The complexity and challenge generated by multiple lines of communication and rapid adaptions to a changing pandemic context was evident.

TRIAL REGISTRATION NUMBER

UKAS 307727-02-01; Pre-results.

CLINICALTRIALS

gov Identifier: NCT05045989 ; post-results (first posted, 16/09/21).

ETHICAL APPROVAL

Faculty of Medicine & Health Sciences Research Ethics Committee, University of Nottingham (Ref: FMHS 96-0920).

[Surgery or not on an atypical breast lesion? Taking anxiety into account in shared decision support from a prospective cohort of 300 patients]

INTRODUCTION

Organized and individual breast screening have been accompanied by an increase in the detection of "atypical breast lesions (ABL)". Recently, the NOMAT multicenter study proposed a predictive model of the risk of developing breast cancer after detection of an ABL in order to avoid surgical removal of "low-risk" lesions. It also aimed to provide information on psychological experience, in particularly anxiety, to assist in the shared medical decision process.

METHODS

Three hundred women undergoing surgery for ABL were included between 2015 and 2018 at 18 French centers. Women completed questionnaires before and after surgery assessing their level of anxiety (STAI-State, STAI-Trait), their level of tolerance to uncertainty, their perceived risk of developing a breast cancer, and their satisfaction with the management care.

RESULTS

One hundred nighty nine patients completed the STAI-Status before and after surgery. Overall, a decrease in anxiety level (35.4 vs 42.7, P<0.001) was observed. Anxious temperament and greater intolerance to uncertainty were significantly associated swith decreased anxiety (33%), whereas younger age was associated with increased anxiety (8%).

CONCLUSION

Surgery for ABL seems to be associated with only a few cases with an increase in anxiety and seems to increase the perception of the risk of developing breast cancer. Taking into account the psychological dimension remains in all cases essential in the process of shared therapeutic decision.

Modeling a disease-correlated tubulin mutation in budding yeast reveals insight into MAP-mediated dynein function

Mutations in the genes that encode α- and β-tubulin underlie many neurological diseases, most notably malformations in cortical development. In addition to revealing the molecular basis for disease etiology, studying such mutations can provide insight into microtubule function and the role of the large family of microtubule effectors. In this study, we use budding yeast to model one such mutation—Gly436Arg in α-tubulin, which is causative of malformations in cortical development—in order to understand how it impacts microtubule function in a simple eukaryotic system. Using a combination of in vitro and in vivo methodologies, including live cell imaging and electron tomography, we find that the mutant tubulin is incorporated into microtubules, causes a shift in α-tubulin isotype usage, and dramatically enhances dynein activity, which leads to spindle-positioning defects. We find that the basis for the latter phenotype is an impaired interaction between She1—a dynein inhibitor—and the mutant microtubules. In addition to revealing the natural balance of α-tubulin isotype utilization in cells, our results provide evidence of an impaired interaction between microtubules and a dynein regulator as a consequence of a tubulin mutation and sheds light on a mechanism that may be causative of neurodevelopmental diseases.

Ciprofloxacin-induces free radical production in rat cerebral microsomes

In the presence of ciprofloxacin (CPFX), free radical adduct formation was demonstrated in rat cerebral microsomes using a spin trap α-(4-pyridyl-1-oxide)-N-tert-butyl-nitrone by electron spin resonance spectroscopy. Active microsomes, dihydronicotinamide-adenine dinucleotide phosphate, and ciprofloxacin were necessary for the formation of a spin trap/radical adduct. Adduct formation increased dose-dependently at 0.5-1 mM CPFX concentration for 180 min, and 0.3-1 mM concentration level for 240 min. The addition of SKF 525A, ZnCl₂ or desferrioxamine to the incubation system caused complete inhibition of the radical formation. However, pretreatment of microsomal system with superoxide dismutase (SOD) did not induce any protective effect. Induction of lipid peroxidation, and depletion of thiol levels by CPFX were also shown in the system. These results strongly suggested that CPFX produces free radical(s) in the cerebral microsomes of rats.

Labeling of native proteins with fluorescent RAFT polymer probes: application to the detection of a cell surface protein using flow cytometry

Fluorescent RAFT polymer probes with an activated ester reactive end-group can be advantageously used to label native proteins.

The effects of di(2-ethylhexyl) phthalate and/or selenium on trace element levels in different organs of rats

Di(2-ethylhexyl)phthalate (DEHP), a widely used plasticizer for synthetic polymers, is known to have endocrine disruptive potential, reproductive toxicity, and induces hepatic carcinogenesis in rodents. Selenium (Se) is a component of several selenoenzymes which are essential for cellular antioxidant defense and for the functions of mammalian reproductive system. The present study was designed to investigate the effects of DEHP exposure on trace element distribution in liver, testis, and kidney tissues and plasma of Se-deficient and Se-supplemented rats. Se deficiency was produced by feeding 3-week old Sprague-Dawley rats with ≤0.05mg Se/kg diet for 5 weeks, and supplementation group were on 1mg Se/kg diet. DEHP treated groups received 1000mg/kg dose by gavage during the last 10 days of feeding period. Se, zinc (Zn), copper (Cu), iron (Fe) and manganese (Mn) levels were measured by inductively coupled plasma mass spectrometry (ICP-MS). Se supplementation caused significant increases in hepatic, renal, and testicular Se levels. With DEHP exposure, plasma Se and Zn, kidney Se, Cu and Mn levels were significantly decreased. Besides, liver Fe decreased markedly in all the DEHP-treated groups. Liver and kidney Mn levels decreased significantly in DEHP/SeD group compared to both DEHP and SeD groups. These results showed the potential of DEHP exposure and/or different Se status to modify the distribution pattern of essential trace elements in various tissues, the importance of which needs to be further evaluated.

Plasmonic bipyramids for fluorescence enhancement and protection against photobleaching

A great number of studies focus their interest on the photophysical properties of fluorescent hybrid gold nanoparticles for potential applications in biotechnologies such as imaging and/or treatment. Spherical gold nanoparticles are known to quench a chromophore fluorescent signal, when moieties are located in their close vicinity. The use of a polymer spacer on such a system allowed only partial recovery of the dye emission by controlling the surface to dye distance. Gold-based anisotropic sharp nanostructures appear to exhibit more interesting features due to the strong electric field generated at their edges and tips. In this paper, a complete study of hybrid fluorescent bipyramidal-like gold nanostructures is presented. We describe the chemical synthesis of gold bipyramids functionalized with fluorescent water-soluble polymers and their photophysics both in solution and on a single object. We show that the use of a bipyramidal shape instead of a spherical one leads to total recovery of the fluorescence and even to an enhancement of the emission of the dyes by a factor of 1.4.

Effects of di(2-ethylhexyl)phthalate on testicular oxidant/antioxidant status in selenium-deficient and selenium-supplemented rats

Di(ethylhexyl)phthalate (DEHP), the most widely used plasticizer, was investigated to determine whether an oxidative stress process was one of the underlying mechanisms for its testicular toxicity potential. To evaluate the effects of selenium (Se), status on the toxicity of DEHP was further objective of this study, as Se is known to play a critical role in testis and in the modulation of intracellular redox equilibrium. Se deficiency was produced in 3-weeks-old Sprague-Dawley rats feeding them ≤0.05 mg Se /kg diet for 5 weeks, and Se-supplementation group was on 1 mg Se/kg diet. DEHP-treated groups received 1000 mg/kg dose by gavage during the last 10 days of the feeding period. Activities of antioxidant selenoenzymes [glutathione peroxidase 1 (GPx1), glutathione peroxidase 4 (GPx4), thioredoxin reductase (TrxR)], catalase (CAT), superoxide dismutase (SOD), and glutathione S-transferase (GST); concentrations of reduced glutathione (GSH), oxidized glutathione (GSSG), and thus the GSH/GSSG redox ratio; and thiobarbituric acid reactive substance (TBARS) levels were measured. DEHP was found to induce oxidative stress in rat testis, as evidenced by significant decrease in GSH/GSSG redox ratio (>10-fold) and marked increase in TBARS levels, and its effects were more pronounced in Se-deficient rats with ∼18.5-fold decrease in GSH/GSSG redox ratio and a significant decrease in GPx4 activity, whereas Se supplementation was protective by providing substantial elevation of redox ratio and reducing the lipid peroxidation. These findings emphasized the critical role of Se as an effective redox regulator and the importance of Se status in protecting testicular tissue from the oxidant stressor activity of DEHP.

The effects of di(2-ethylhexyl)phthalate on rat liver in relation to selenium status

This study was performed to determine the hepatotoxicity of di(2-ethylhexyl)phthalate (DEHP) in relation to selenium status. In 3-week-old Sprague-Dawley rats, selenium deficiency was induced by a ≤0.05 selenium mg/kg. A selenium supplementation group was given 1 mg selenium/kg diet for 5 weeks. Di(2-ethylhexyl)phthalate-treated groups received 1000 mg/kg dose by gavage during the last 10 days of the experiment. Histopathology, peroxisome proliferation, catalase (CAT) immunoreactivity and activity and apoptosis were assessed. Activities of antioxidant selenoenzymes [glutathione peroxidase 1 (GPx1), glutathione peroxidase 4 (GPx4), thioredoxin reductase (TrxR1)], superoxide dismutase (SOD), and glutathione S-transferase (GST); aminotransferase, total glutathione (tGSH), and lipid peroxidation (LP) levels were measured. Di(2-ethylhexyl)phthalate caused cellular disorganization while necrosis and inflammatory cell infiltration were observed in Se-deficient DEHP group (DEHP/SeD). Catalase activity and immunoreactivity were increased in all DEHP-treated groups. Glutathione peroxidase 1 and GPx4 activities decreased significantly in DEHP and DEHP/SeD groups, while GST activities decreased in all DEHP-exposed groups. Thioredoxin reductase activity increased in DEHP and DEHP/SeS, while total SOD activities increased in all DEHP-treated groups. Lipid peroxidation levels increased significantly in SeD (26%), DEHP (38%) and DEHP/SeD (71%) groups. Selenium supplementation partially ameliorated DEHP-induced hepatotoxicity; while in DEHP/SeD group, drastic changes in hepatic histopathology and oxidative stress parameters were observed.

Oxidative stress induced by cadmium in the C6 cell line: role of copper and zinc

In this report, we have investigated the role of copper (Cu) and zinc (Zn) in oxidative stress induced by cadmium (Cd) in C6 cells. Cells were exposed to 20 μM Cd, 500 μM Cu, and 450 μM Zn for 24 h. Then, toxic effects, cellular metals levels, oxidative stress parameters, cell death, as well as DNA damage were evaluated. Cd induced an increase in cellular Cd, Cu, and Zn levels. This results not only in the inhibition of GSH-Px, GRase, CAT, and SOD activities but also in ROS overproduction, oxidative damage, and apoptotic cell death not related to Cu and Zn mechanisms. The thiol groups and GSH levels decreased, whereas the lipid peroxidation and DNA damage increased. The toxicity of Zn results from the imbalance between the inhibition of antioxidant activities and the induction of MT synthesis. The increase in Cu and Zn levels could be explained by the disruption of specific transporter activities, Cd interference with signaling pathways, and metal displacement. Our results suggest that the alteration of Cu and Zn homeostasis is involved in the oxidative stress induced by Cd.

Low doses of selenium specifically stimulate the repair of oxidative DNA damage in LNCaP prostate cancer cells

Epidemiological studies have demonstrated an inverse relationship between selenium (Se) intake and cancer incidence and/or mortality. However, the molecular mechanisms underlying the cancer chemopreventive activity of Se compounds remain largely unknown. The objective of this study was to investigate the effect of low doses of Se on the stimulation of DNA repair systems in response to four different qualities of DNA damage. P53-proficient LNCaP human prostate adenocarcinoma cells were grown either untreated or in the presence of low concentrations of two Se compounds (30° nM sodium selenite, or 10 μM selenomethionine) and exposed to UVA, H2O2, methylmethane sulfonate (MMS) or UVC. Cell viability as well as DNA damage induction and repair were evaluated by the alkaline Comet assay. Overall, Se was shown to be a very potent protector against cell toxicity and genotoxicity induced by oxidative stress (UVA or H2O2) but not from the agents that induce other types of deleterious lesions (MMS or UVC). Furthermore, Se-treated cells exhibited increased oxidative DNA repair activity, indicating a novel mechanism of Se action. Therefore, the benefits of Se could be explained by a combination of antioxidant activity, the reduction in DNA damage and the enhancement of oxidative DNA repair capacity.

The toxicity redox mechanisms of cadmium alone or together with copper and zinc homeostasis alteration: its redox biomarkers

Cadmium (Cd) is a toxic metal and can induce and/or promote diseases in humans (cancer, aging diseases, kidney and bone diseases, etc.). Its toxicity involves many mechanisms including the alteration of copper (Cu) and zinc (Zn) homeostasis leading to reactive oxygen species (ROS) production, either directly or through the inhibition of antioxidant activities. Importantly, ROS can induce oxidative damages in cells. Cadmium, Cu and Zn are also able to induce glutathione (GSH) and metallothioneins (MT) synthesis in a cell-type-dependent manner. As a consequence, the effects induced by these three metals result simultaneously from the inhibition of antioxidant activities and the induction of other factors such as GSH and MT synthesis. MT levels are regulated not only by the p53 protein in a cell-type-dependent manner, or by transcription factors such as metal-responsive transcription factor 1 (MTF-1) and cellular Zn levels but also by cellular GSH level. As described in the literature, DNA damage, GSH and MT levels are sensitive biomarkers used to identify Cd-induced toxicity alone or together with Cu and Zn homeostasis alteration.

Effect of selenium pre-treatment on plasma antioxidant vitamins A (retinol) and E (α-tocopherol) in static magnetic field-exposed rats

In the present study, we evaluate the effect of the co-exposure to static magnetic field (SMF) and selenium (Se) on the antioxidant vitamins A and E levels and some other parameters of oxidative stress in rat. Sub-acute exposure of male adult rats to a uniform SMF (128 mT, 1 h/day during 5 consecutive days) increased plasma activity of glutathione peroxidase (+35%) but decreased α-tocopherol (−67%) and retinol levels (−41%). SMF exposure failed to alter the plasmatic thiobarbituric acid-reactive species (TBARs), total thiol groups and selenium concentrations. Sub-chronic administration of Se (Na2SeO3, 0.2 mg/L, for 30 consecutive days, per os) ameliorated the antioxidant capacities in SMF-treated rats. Our investigation demonstrated that sub-acute exposure to SMF induced oxidative stress, which may be prevented by a pretreatment with selenium.

Selenium supplementation ameliorates static magnetic field-induced disorders in antioxidant status in rat tissues

The aim of this study was to investigate the effect of selenium supplementation on the antioxidant enzymatic system (such as GPx, GR and SOD), GSH and selenium level in liver, kidney, muscle and brain of static magnetic field (SMF) exposed rats. Male adult rats were divided into control rats (n=6), SMF-exposed rats (128 mT; 1h/day for 5 days), selenium-treated rats (Na(2)SeO(3), 0.2mg/l, in drinking water for 4 weeks) and co-exposed rats (selenium for 4 weeks and SMF during the last 5 consecutive days). Sub-acute exposure to SMF induces a decrease of selenium levels in kidney, muscle and brain. Our results also revealed a decrease of GPx activities in kidney and muscle. By contrast, SMF exposure increased total GSH levels and total SOD activities in liver, while glutathione reductase activity is unaffected. Selenium supplementation in SMF-exposed rats restored selenium levels in kidney, muscle and brain and elevated the activities of GPx in kidney and muscle to those of control group. In the liver, selenium supplementation failed to bring down the elevated levels of total GSH and SOD activity. Our investigations suggested that sub-acute exposure to SMF altered the antioxidant response by decreasing the level of total selenium in kidney, muscle and brain. Interestingly, selenium supplementation ameliorates antioxidant capacity in rat tissues exposed to SMF.

TOX4 and its binding partners recognize DNA adducts generated by platinum anticancer drugs

Platinating agents are commonly prescribed anticancer drugs damaging DNA. Induced lesions are recognized by a wide range of proteins. These are involved in cellular mechanisms such as DNA repair, mediation of cytotoxicity or chromatin remodeling. They therefore constitute crucial actors to understand pharmacology of these drugs. To expand our knowledge about this subproteome, we developed a ligand fishing trap coupled to high throughput proteomic tools. This trap is made of damaged plasmids attached to magnetic beads, and was exposed to cell nuclear extracts. Retained proteins were identified by nanoHPLC coupled to tandem mass spectrometry. This approach allowed us to establish a list of 38 proteins interacting with DNA adducts generated by cisplatin, oxaliplatin and satraplatin. Some of them were already known interactome members like high mobility group protein 1 (HMGB1) or the human upstream binding factor (hUBF), but we also succeeded in identifying unexpected proteins such as TOX HMG box family member 4 (TOX4), phosphatase 1 nuclear targeting subunit (PNUTS), and WD repeat-containing protein 82 (WDR82), members of a recently discovered complex. Interaction between TOX4 and platinated DNA was subsequently validated by surface plasmon resonance imaging (SPRi). These interactions highlight new cellular responses to DNA damage induced by chemotherapeutic agents.

Chromium III histidinate exposure modulates gene expression in HaCaT human keratinocytes exposed to oxidative stress

While the toxicity of hexavalent chromium is well established, trivalent chromium is an essential nutrient involved in insulin and glucose homeostasis. To study the antioxidant effects of Cr(III)His, cDNA arrays were used to investigate the modulation of gene expression by trivalent chromium histidinate (Cr(III)His) in HaCaT human keratinocytes submitted to hydrogen peroxide (H2O2). Array was composed by a set of 81 expressed sequences tags (ESTs) essentially represented by antioxidant and DNA repair genes. HaCaT were preincubated for 24 h with 50 microM Cr(III)His and were treated with 50 muM H2O2. Total RNAs were isolated immediately or 6 h after the stress. In Cr(III)His preincubated cells, transcripts related to antioxidant family were upregulated (glutathione synthetase, heme oxygenase 2, peroxiredoxin 4). In Cr(III)His preincubated cells and exposed to H2O2, increased expressions of polymerase delta 2 and antioxidant transcripts were observed. Biochemical methods performed in parallel to measure oxidative stress in cells showed that Cr(III)His supplementation before H2O2 stress protected HaCaT from thiol groups decrease and thiobarbituric acid reactive substances increase. In summary, these results give evidence of antioxidant gene expression and antioxidant protection in HaCaT preincubated with Cr(III)His and help to explain the lack of toxicity reported for Cr(III)His.

Effects of static magnetic field and cadmium on oxidative stress and DNA damage in rat cortex brain and hippocampus

The present study was undertaken to determine the effect of co-exposure to static magnetic field (SMF) and cadmium (Cd) on the antioxidant enzymes activity and DNA integrity in rat brain. Sub-chronic exposure to CdCl (CdCl(2), 40 mg/L, per os) for 30 days resulted in a significant reduction in antioxidant enzyme activity such as the glutathione peroxidase (GPx), catalase (CAT) and superoxide dismutase (SOD) in frontal cortex and hippocampus. Total GSH were decreased in the frontal cortex of the Cd-exposed group. Cd exposure induced an increase in malondialdehyde (MDA) concentration in the frontal cortex and hippocampus. Moreover, the same exposure increased 8-oxo-7,8-dihydro-2-desoxyguanosine (8-oxodGuo) level in rat brain. Interestingly, the combined effect of SMF (128 mT, 1 hour/day for 30 consecutive days) and CdCl (40 mg/L, per os) decreased the SOD activity and glutathione level in frontal cortex as compared with the Cd group. Moreover, the association between SMF and Cd increased MDA concentration in frontal cortex as compared with Cd-exposed rats. DNA analysis revealed that SMF exposure failed to alter 8-oxodGuo concentration in Cd-exposed rats. Our data showed that Cd exposure altered the antioxidant enzymes activity and induced oxidative DNA lesions in rat brain. The combined effect of SMF and Cd increased oxidative damage in rat brain as compared with Cd-exposed rats.

Protective effect of selenium supplementation on the genotoxicity of di(2-ethylhexyl)phthalate and mono(2-ethylhexyl)phthalate treatment in LNCaP cells

Selenium is an essential cofactor in the key enzymes involved in cellular antioxidant defense. It plays a critical role in testis and reproduction and regulates DNA damage within the prostate. Phthalates are ubiquitous environmental contaminants that cause alterations in endocrine and spermatogenic functions in animals. The objective of this study was to investigate the cytotoxicity and genotoxicity potentials of di(2-ethylhexyl)phthalate (DEHP), the most widely used phthalate and its primary toxic metabolite mono(2-ethylhexyl)phthalate (MEHP), and their effects on the antioxidant balance in the LNCaP human prostate adenocarcinoma cell line. Protection by selenium supplementation with either sodium selenite (SS, 30 nM) or selenomethionine (SM, 10 microM) was also investigated. Both DEHP (3mM) and MEHP (3 microM) caused significant decreases in cell viability; altered antioxidant status, particularly decreasing the GPx1 activity; and induced DNA damage as measured by the alkaline comet assay. Selenium supplementation was highly protective against cytotoxicity, partially prevented genotoxicity, and restored the antioxidant status. The results of this study suggested that the underlying mechanism of cytotoxicity and resulting disturbances produced by DEHP or MEHP was an an oxidative stress process and/or an effect on the expression of antioxidant enzymes, and accentuated the importance of selenium status, particularly with respect to the high probability of phthalate exposures and their adverse effects.

Trace elements status in multinodular goiter

Importance of iodine and selenium in thyroid metabolism is well known, but the roles of other essential trace elements including copper, zinc, manganese and iron on thyroid hormone homeostasis remain unclear. The aim of this study was to investigate the status of those trace elements in benign thyroid diseases and evaluate possible links between trace element concentrations and thyroid hormones. The study group was composed of 25 patients with multinodular goiter. Concentrations of thyroid hormones (plasma-free thyroxine, FT(4); free triiodothyronine, FT(3); and thyrotropin, TSH), selenium, copper, zinc, manganese and iron in plasma, and urinary iodine were determined. The results were compared with those of a healthy control group (n=20) with no thyroid disorder. A mild iodine deficiency was observed in the patients with multinodular goiter whereas urinary iodine levels were in the range of "normal" values in healthy controls. All patients were euthyroid, and their thyroid hormone concentrations were not significantly different from the control group. Plasma selenium, zinc and iron concentrations did not differ from controls, while copper and manganese levels were found to be significantly higher in the patients with multinodular goiter indicating links between these trace elements and thyroid function and possibly in development of goiter. Besides iodine, there was a significant correlation between plasma copper concentration and FT(3)/FT(4) ratio.

[Management of ear, nose, and throat diseases in district hospital centers in Madagascar]

The purpose of this report is to describe the experience of a specialized medico-surgical ENT team sent to hospital centers in Atalaha and Tulear, Madagascar by a nonprofit organization called "Terre rouge" from the Reunion Island. In three separate short-term missions, a total of 93 patients received care. Discussion focuses on the particular pathological, cultural, and pedagogical features of the Island and on the resources that were deployed during the missions. Providing ENT care in district hospitals in Madagascar requires adaptation to the difficult climatic conditions, poor hospital facilities (infrastructure, equip ment, and personnel), and advanced stage of diseases. To ensure continuous access to ENT care, it will be necessary to provide practical and didactic training for healthcare personnel in the country.

Metallothionein expression in HaCaT and C6 cell lines exposed to cadmium

Metallothioneins (MT) are low-molecular weight, cysteine-rich metal-binding proteins. MT play a role in the homeostasis of essential metals such as zinc (Zn) and copper (Cu), detoxification of toxic metals such as cadmium (Cd) and protection against oxidative stress. In this study, we examined the expression of MT in HaCaT and C6 cells as a strategy to enhance protection against Cd-mediated toxicity. At basal level, HaCaT cells showed higher MT level than C6 cells which could explain the resistance of HaCaT cells. Western blot showed that C6 cells treated with 20micromol/L Cd for 24h did not express any MT. MT were initially expressed in the cytoplasmic or periplasmic compartment and were then translocated in the nucleus after 24h treatment by Cd both in HaCaT and C6 cells. In addition, the cell treatment with Cd was followed by an increase in the cellular zinc level but the electrophoretic mobility shift assay (EMSA) experiment did not show any translocation of metal-responsive transcription factor-1 (MTF-1) to the nucleus of HaCaT cells. These absence of translocation could be due to the presence of MT in these cells at the basal state. The translocation study in HaCaT cells suggested that the MT translocation in the nucleus was greater than observed in C6 cells. The latter observation could explain HaCaT cells resistance to Cd concentrations up to 50micromol/L. Our results suggested that the C6 cell sensitivity was correlated with the decrease in MT level at 20micromol/L Cd occurring after the transcription of MT gene.

Effects of long-term antioxidant supplementation and association of serum antioxidant concentrations with risk of metabolic syndrome in adults

BACKGROUND

Limited observational evidence suggests lower antioxidant concentrations in individuals with the metabolic syndrome (MetS); few randomized controlled trials have addressed the effect of multiple antioxidants on the risk of MetS.

OBJECTIVE

The objective was to examine the effect of antioxidant supplementation for 7.5 y on the incidence of MetS and the epidemiologic association between baseline serum antioxidant concentrations and the prospective risk of MetS.

DESIGN

Adults (n = 5220) participating in the SUpplementation en VItamines et Minéraux AntioXydants (SU.VI.MAX) primary prevention trial were randomly assigned to receive a supplement containing a combination of antioxidants (vitamins C and E, beta-carotene, zinc, and selenium) at nutritional doses or a placebo. Subjects were free of MetS at baseline and were followed for 7.5 y.

RESULTS

Antioxidant supplementation for 7.5 y did not affect the risk of MetS. Baseline serum antioxidant concentrations of beta-carotene and vitamin C, however, were negatively associated with the risk of MetS; the adjusted odds ratios (and 95% CIs) for the highest compared with the lowest tertile were 0.34 (0.21, 0.53; P for trend = 0.0002) and 0.53 (0.35, 0.80; P for trend = 0.01), respectively. Baseline serum zinc concentrations were positively associated with the risk of developing MetS; the adjusted odds ratio (and 95% CI) for the highest compared with the lowest tertile was 1.81 (1.20, 2.72; P for trend = 0.01).

CONCLUSIONS

The experimental finding of no beneficial effects of antioxidant supplementation in a generally well-nourished population is consistent with recent reports of a lack of efficacy of antioxidant supplements. However, the relations observed between the risk of MetS and baseline serum antioxidant concentrations, which probably reflect associations with overall dietary patterns, do support the current recommendations to consume antioxidant-rich foods. This trial was registered at clinicaltrials.gov as NCT00272428.

Leukocyte 8-oxo-7,8-dihydro-2′-deoxyguanosine and comet assay in epirubicin-treated patients

Epirubicin fights cancer through topoisomerase II inhibition, hence producing DNA strand breaks that finally lead to cell apoptosis. But anthracyclines produce free radicals that may explain their adverse effects. Dexrazoxane--an iron chelator--was proven to decrease free radical production and anthracycline cardiotoxicity. In this article, we report the concentrations of cellular 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dGuo) relative to 2'-deoxyguanosine (dGuo), and comet assay results from a study including 20 cancer patients treated with epirubicin. Plasma concentrations of vitamins A, E, C and carotenoids are also reported. All data were obtained before and immediately after epirubicin infusion. The ratios of 8-Oxo-dGuo to dGuo were measured in leukocyte DNA by HPLC-coulometry after NaI extraction of nucleic acids. Vitamins A and E and carotenoids were measured by HPLC-spectrophotometry. Vitamin C was measured by HPLC-spectrofluorimetry. Median 8-oxo-dGuo/dGuo ratios increased significantly from 0.34 to 0.48 lesions per 100,000 bases while per cent of tail DNA increased from 3.47 to 3.94 after chemotherapy 8-Oxo-dGuo/dGuo and per cent of tail DNA medians remained in the normal range. Only vitamin C decreased significantly from 55.4 to 50.3 microM Decreases in vitamins A, E, lutein and zeaxanthin were not significant, but concentrations were below the lower limit of the normal range both before and after chemotherapy. Only the correlation between comet assay results and vitamin C concentrations was significant (rho =-0.517, p = 0.023). This study shows that cellular DNA is damaged by epirubicin-generated free radicals which produce the mutagenic modified base 8-oxo-dGuo and are responsible for strand breaks. However, strand breaks are created not only by free radicals but also by topoisomerase II inhibition. In a previous study we did not find any significant change in urinary 8-oxo-dGuo excretion after adriamycin treatment. However, 8-oxo-dGuo may have increased at the end of urine collection as DNA repair and subsequent kidney elimination are relatively slow processes. In another study, authors used GC-MS to detect 8-oxo-dGuo in DNA and did not find any change after prolonged adriamycin infusion. Reasons for these apparent discrepancies are discussed.

Determination of dansylated polyamines in red blood cells by liquid chromatography-tandem mass spectrometry

The concentration of polyamines in red blood cells (RBCs) is considered to be an index of cell proliferation. This index has been demonstrated to be of clinical importance for the follow-up and treatment of some cancer patients. The concentration of polyamines in RBCs is usually determined by high-performance liquid chromatography (HPLC) with fluorescence detection. In the current work, we present a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantification of putrescine, spermidine, and spermine, the three major polyamines in RBCs. The polyamines were dansylated and analyzed by an LC gradient of 20-min duration on a C18 column on-line with a tandem mass spectrometer. An internal standard (1,8-diaminooctane) was used for quantification. This method exhibited excellent linearity for the three polyamines with regression coefficients higher than 0.99. The limits of detection for putrescine, spermidine, and spermine were 0.10, 0.75, and 0.50 pmol/ml, respectively. The intrarun precision values for putrescine, spermidine, and spermine all were better than 10%, and the interrun precision values were 13%, 9%, and 20%, respectively. The LC-MS/MS method is sufficiently simple and reliable enough to replace the currently used HPLC method with fluorescence detection in which putrescine is not always detectable.

Changes in antioxidant status and biochemical parameters after orally cadmium administration in females rats

The research was conducted to investigate the toxic effects of cadmium chloride (CdCl2), administered during gestation period on female Wistar rats. Pregnant rats received CdCl2 (20 mg/l, orally) from Day 6 to Day 19 of pregnancy. Results showed that Cd treatment induced a decrease in body weight gain. The relative liver weight increased significantly, with a marked decrease of glycogen and total lipids content. The administration of Cd induced hepatotoxicity as indicated by elevations in plasma alanine aminotransferase (ALT), aspartate aminotransferase and lactate dehydrogenase (LDH) activities (p < 0.05). Treatment with CdCl2 caused a significant (p < 0.05) increase in glucose. A significant increase was observed in the level of MDA and 8-oxodGuo tissues in the cadmium-exposed group compared to the control group (p < 0.05). Results showed that cadmium given to dams led to an oxidative stress and DNA damage in tissues of pregnant rats.

Prion protein protects against zinc-mediated cytotoxicity by modifying intracellular exchangeable zinc and inducing metallothionein expression

PrPC contains several octapeptide repeats sequences toward the N-terminus which have binding affinity for divalent metals such as copper, zinc, nickel and manganese. However, the link between PrPC expression and zinc metabolism remains elusive. Here we studied the relationship between PrPC and zinc ions intracellular homeostasis using a cell line expressing a doxycycline-inducible PrPC gene. No significant difference in 65Zn2+ uptake was observed in cells expressing PrPC when compared with control cells. However, PrPC-expressing cells were more resistant to zinc-induced toxicity, suggesting an adaptative mechanism induced by PrPC. Using zinquin-ethyl-ester, a specific fluorophore for vesicular free zinc, we observed a significant re-localization of intracellular exchangeable zinc in vesicles after PrPC expression. Finally, we demonstrated that PrPC expression induces metallothionein (MT) expression, a zinc-upregulated zinc-binding protein. Taken together, these results suggest that PrPC modifies the intracellular localization of zinc rather than the cellular content and induces MT upregulation. These findings are of major importance since zinc deregulation is implicated in several neurodegenerative disorders. It is postulated that in prion diseases the conversion of PrPC to PrPSc may deregulate zinc homeostasis mediated by metallothionein.

A microarray to measure repair of damaged plasmids by cell lysates

DNA repair mechanisms constitute major defences against agents that cause cancer, degenerative disease and aging. Different repair systems cooperate to maintain the integrity of genetic information. Investigations of DNA repair involvement in human pathology require an efficient tool that takes into account the variety and complexity of repair systems. We have developed a highly sensitive damaged plasmid microarray to quantify cell lysate excision/synthesis (ES) capacities using small amounts of proteins. This microsystem is based on efficient immobilization and conservation on hydrogel coated glass slides of plasmid DNA damaged with a panel of genotoxic agents. Fluorescent signals are generated from incorporation of labelled dNTPs by DNA excision-repair synthesis mechanisms at plasmid sites. Highly precise DNA repair phenotypes i.e. simultaneous quantitative measures of ES capacities toward seven lesions repaired by distinct repair pathways, are obtained. Applied to the characterization of xeroderma pigmentosum (XP) cells at basal level and in response to a low dose of UVB irradiation, the assay showed the multifunctional role of different XP proteins in cell protection against all types of damage. On the other hand, measurement of the ES of peripheral blood mononuclear cells from six donors revealed significant diversity between individuals. Our results illustrate the power of such a parallelized approach with high potential for several applications including the discovery of new cancer biomarkers and the screening of chemical agents modulating DNA repair systems.