Co-administration of Selenium with Inorganic Mercury Alters the Disposition of Mercuric Ions in Rats

Mercury (Hg) is a common environmental toxicant to which humans are exposed regularly through occupational and dietary means. Although selenium supplementation has been reported to prevent the toxic effects of Hg in animals, the mechanisms for this prevention are not well understood. The purpose of the current study was to determine the effects of selenium on the disposition and toxicity of Hg. Wistar rats were injected intravenously with a non-nephrotoxic dose (0.5 μmol kg^-1) or a nephrotoxic dose (2.5 μmol kg^-1) of HgCl₂ (containing radioactive Hg) with or without co-administration of sodium selenite (Na₂SeO₃). Twenty-four hours after exposure, rats were euthanized, and organs were harvested. Co-administration of SeO₃^2- with HgCl₂ reduced the renal burden of Hg and the urinary excretion of Hg while increasing the amount of Hg in blood and spleen. We propose that Hg reacts with reduced selenite in the blood to form large Hg-Se complexes that are unable to be filtered at the glomerulus. Consequently, these complexes remain in the blood and are able to accumulate in blood-rich organs. These complexes, which may have fewer toxic effects than other species of Hg, may be eliminated slowly over the course of weeks to months.

Prioritising physical and psychological symptoms: what are the barriers and facilitators to the discussion of anxiety in the primary care consultation?

Background

Anxiety is under-recorded and under-treated in the UK and is under-represented in research compared with depression. Detecting anxiety can be difficult because of co-existing conditions. GPs can be reluctant to medicalise anxiety symptoms and patients can be reluctant to disclose them, for a variety of reasons. This research addresses the gap in evidence of real-life consultations of patients with anxiety and explores how physical and psychological symptoms are discussed and prioritised by patients and GPs in primary care consultations.

Methods

A mixed methods study using a baseline questionnaire, video-recorded primary care consultations and interview data with patients and GPs.

Results

Seventeen patients with anxiety symptoms (GAD-7 score ≥ 10) completed a questionnaire, had their consultation video-recorded and took part in a semi-structured interview. Four GPs were interviewed. The main themes that emerged from GP and patients accounts as barriers and facilitators to discussing anxiety mostly mirrored each other. The GP/patient relationship and continuity of care was the main facilitator for the discussion of anxiety in the consultation. The main barriers were: attribution of or unacknowledged symptoms; co-morbidities; and time constraints. GPs overcame these barriers by making repeat appointments and employing prioritising techniques; patients by choosing an empathetic GP.

Conclusions

The findings add to the evidence base concerning the management of anxiety in primary care. The findings suggest that the discussion around anxiety is a process negotiated between the patient and the GP influenced by a range of barriers and facilitators. Co-existing depression and health anxieties can mask anxiety symptoms in patients. Good practice techniques such as bringing back patients for appointments to foster continuity of care and understanding can help disclosure and detection of anxiety symptoms. Future research could investigate this longitudinally and should include a wider range of GPs practices and GPs.

Electronic supplementary material

The online version of this article (10.1186/s12875-019-0996-6) contains supplementary material, which is available to authorized users.

Potential mechanisms of cellular injury following exposure to a physiologically relevant species of inorganic mercury

Mercury is a toxic metal that is found ubiquitously in the environment. Humans are exposed to different forms of mercury via ingestion, inhalation, and/or dermal absorption. Following exposure, mercuric ions may gain access to target cells and subsequently lead to cellular intoxication. The mechanisms by which mercury accumulation leads to cellular injury and death are not understood fully. Therefore, purpose of this study was to identify the specific intracellular mechanisms that are altered by exposure to inorganic mercury (Hg²⁺). Normal rat kidney (NRK) cells were exposed to a physiologically relevant form of Hg²⁺, as a conjugate of cysteine (10 μM or 50 μM). Alterations in oxidative stress were estimated by measuring lipid peroxidation and mitochondrial oxidative stress. Alterations in actin and tubulin were measured using specific fluorescent dyes. Calcium levels were measured using Fluo-3 AM Calcium Indicator while autophagy was identified with Premo^™ Autophagy Sensor LC3B-GFP. The current findings show that exposure to Hg²⁺ leads to enhanced oxidative stress, alterations in cytoskeletal structure, increases in intracellular calcium, and enhanced autophagy. We have established a more complete understanding of intoxication and cellular injury induced by a relevant form of Hg²⁺ in proximal tubule cells.

Correction to: The help for people with money, employment or housing problems (HOPE) intervention: pilot randomised trial with mixed methods feasibility research

[This corrects the article DOI: 10.1186/s40814-018-0365-6.].

The help for people with money, employment or housing problems (HOPE) intervention: pilot randomised trial with mixed methods feasibility research

Background

Job loss, austerity measures, financial difficulties and house repossession contribute to the risk of self-harm and suicide during recessions. Navigating the benefits system and accessing sources of welfare and debt advice is a difficult experience for vulnerable people, further contributing to their distress. Whilst there is some evidence that advice-type interventions can lead to financial gain, there is mixed evidence for their effectiveness in improving mental health in those experiencing financial difficulties. There have been no interventions targeting those who have self-harmed due to economic hardship.

Methods

Our aim was to determine the feasibility and acceptability of a brief psychosocial intervention (the ‘HOPE’ service) for people presenting to hospital emergency departments (ED) following self-harm or in acute distress because of financial, employment or welfare (benefit) difficulties. Nineteen people consented to random allocation to the intervention or control arm on a 2:1 basis. Participants randomised to the intervention arm (n = 13) received up to six sessions of 1:1 support provided by community support staff trained in Motivational Interviewing (MI). Control participants (n = 6) received a one-off session signposting them to relevant support organisations. Fourteen participants were followed up after 3 months. Participants and mental health workers took part in qualitative interviews. The acceptability of outcome measures including the PHQ-9, GAD-7, repeat self-harm, EQ5D-5 L and questions about debt, employment and welfare benefits were explored.

Results

Interviews indicated the main benefits of the service as the resolution of specific financial problems and receiving support when participants were feeling most vulnerable. Randomisation was acceptable to most participants although not always fully understood and control participants could be disappointed. Recruitment was slow (1–2 per month). The outcome measures were acceptable and appeared sensitive to change.

Discussion

The HOPE intervention is feasible and acceptable. There was evidence of need and it is a relatively inexpensive intervention. Refining aspects of the intervention would be straightforward. A full-scale RCT would be feasible, if broadened eligibility criteria led to increased recruitment and improvements were made to staff training and support.

Trial registration

ISRCTN58531248.

Electronic supplementary material

The online version of this article (10.1186/s40814-018-0365-6) contains supplementary material, which is available to authorized users.

Exposure to mixtures of mercury, cadmium, lead, and arsenic alters the disposition of single metals in tissues of Wistar rats

Humans throughout the world are exposed regularly to mixtures of environmental toxicants. Four of the most common heavy metal toxicants in the environment are mercury (Hg), cadmium (Cd), lead (Pb), and arsenic (As). Numerous studies have assessed the effects and disposition of individual metals in organ systems; however, humans are usually exposed to mixtures of toxicants or metals rather than to a single toxicant. Therefore, the purpose of the current study was to test the hypothesis that exposure to a mixture of toxic heavy metals alters the disposition of single metals in target organs. Wistar rats (Rattus norvegicus) were exposed to Hg, Cd, Pb, or As as a single metal or as a mixture of metals. Rats were injected intravenously for three days, following which kidneys, liver, brain, and blood were harvested. Samples were analyzed for content of Hg, Cd, Pb, and As via inductively coupled plasma mass spectrometry. In general, exposure to a mixture of metals reduced accumulation of single metals in target organs. Interestingly, exposure to mixtures of metals with Pb and/or As increased the concentration of these metals specifically in the liver. The findings from this study indicate that exposure to mixtures of toxic heavy metals may alter significantly the distribution and accumulation of these metals in target organs and tissues.

HOPE: Help fOr People with money, employment, benefit or housing problems: study protocol for a randomised controlled trial

BACKGROUND

Self-harm and suicide increase in times of economic recession. Factors including job loss, austerity measures, financial difficulties and house repossession contribute to the risk. Vulnerable individuals commonly experience difficulties in navigating the benefits system and in accessing the available sources of welfare and debt advice, and this contributes to their distress. Our aim is to determine the feasibility and acceptability of a brief psychosocial intervention (the "HOPE" service) for people presenting to hospital emergency departments (ED) following self-harm or in acute distress because of financial, employment, or welfare (benefit) difficulties.

METHOD

A pilot study including randomisation will be employed to determine whether it is possible to undertake a full-scale trial. Twenty people presenting to the ED who have self-harmed, have suicidal thoughts and depression and/or are in crisis and where financial, employment or benefit problems are cited as contributory factors will be asked to consent to random allocation to the intervention or control arm on a 2:1 basis. People who require secondary mental health follow-up will be excluded. Those randomised to the intervention arm will receive up to six sessions with a mental health worker who will provide practical help with financial and other problems. The mental health worker will use the motivational interviewing method in their interactions with participants. Control participants will receive one session signposting them to existing relevant support organisations. Participants will be followed up after 3 months. Participants and the mental health workers will take part in qualitative interviews to enable refinement of the intervention. The acceptability of outcome measures including the PHQ-9, GAD-7, repeat self-harm, EQ5D-5L and questions about debt, employment and welfare benefits will be explored.

DISCUSSION

This study will assess whether a full-scale randomised trial of this novel intervention to prevent self-harm among those distressed because of financial difficulties is feasible, including the acceptability of randomisation, potential rate of recruitment and the acceptability of outcome measures.

TRIAL REGISTRATION

ISRCTN58531248.

Understanding vulnerability to self-harm in times of economic hardship and austerity: a qualitative study

OBJECTIVE

Self-harm and suicide increase in times of economic recession, but little is known about why people self-harm when in financial difficulty, and in what circumstances self-harm occurs. This study aimed to understand events and experiences leading to the episode of self-harm and to identify opportunities for prevention or mitigation of distress.

SETTING

Participants' homes or university rooms.

PARTICIPANTS

19 people who had attended hospital following self-harm in two UK cities and who specifically cited job loss, economic hardship or the impact of austerity measures as a causal or contributory factor.

PRIMARY AND SECONDARY OUTCOME MEASURES

Semistructured, in-depth interviews. Interviews were audio recorded, transcribed and analysed cross-sectionally and as case studies.

RESULTS

Study participants described experiences of severe economic hardship; being unable to find employment or losing jobs, debt, housing problems and benefit sanctions. In many cases problems accumulated and felt unresolvable. For others an event, such as a call from a debt collector or benefit change triggered the self-harm. Participants also reported other current or past difficulties, including abuse, neglect, bullying, domestic violence, mental health problems, relationship difficulties, bereavements and low self-esteem. These contributed to their sense of despair and worthlessness and increased their vulnerability to self-harm. Participants struggled to gain the practical help they felt they needed for their economic difficulties or therapeutic support that might have helped with their other co-existing or historically damaging experiences.

CONCLUSIONS

Economic hardships resulting from the recession and austerity measures accumulated or acted as a 'final straw' to trigger self-harm, often in the context of co-existing or historically damaging life-experiences. Interventions to mitigate these effects should include providing practical advice about economic issues before difficulties become insurmountable and providing appropriate psychosocial support for vulnerable individuals.

Can early infection explain the sibling effect in adult atopy?

Atopy is strongly and inversely related to family size, a pattern which is plausibly assumed to reflect a protective effect of early infection. The current study tested this hypothesis by case-referent analysis of an adult cohort in the UK. The study established that atopy, defined by prick tests to common aeroallergens, was less common among those from larger families after adjustment for potentially confounding factors. In particular, a higher number of brothers appeared to offer protection. The current authors attempted to explain this distribution by examining contemporary family-doctor records of early childhood infections; and by a number of other indirect indices of early-life "hygiene". The sibling effect was unexplained by evidence of infection with either hepatitis A or Helicobacter pylori, or by counts of infections or antibiotic prescriptions in early life. There was a significant and independent negative association between the number of gastrointestinal infections before the age of 5 yrs and the odds of atopy. Dog ownership and home moving in early life also displayed potentially protective associations. Although the current study replicates the finding that atopy is inversely associated with family size this could not be explained by documentary or serological evidence of early infection. The findings support the suggestion that the "sibling effect" in atopy may not simply reflect protection by early infection.

Do primary afferent cell numbers change in relation to increasing weight and surface area in adult rats?

Adult mammalian primary afferent neurogenesis implies considerably more plasticity for the adult nervous system than is presently envisioned. One hypothesis is that such neurogenesis does not occur, because no tritiated-thymidine-labeled or mitosing neurons are observed in adults, and no increase in cells can be found in young as compared to old adults. The other hypothesis is that adult primary afferent neurogenesis does occur, but that it has not been observed because it is correlated with changes in the size of the animals. This has not been tested, and because of the implications of adult neurogenesis, it is important to see whether dorsal root ganglion (DRG) cell numbers increase with animal size. This is particularly pertinent because of recent advances in the technology for counting neurons and improved methods for resolving the cells in question. The present results indicate that DRG cell numbers are approximately the same in animals whose sizes are different by a factor of approximately 5. Thus our data are consistent with the hypothesis that numbers of adult DRG cells are stable, and we cannot demonstrate a change in relation to age or body size in our animals. Therefore, we do not find evidence of adult neurogenesis in our animals.

The role of Ia molecules in the activation of T lymphocytes. II. Ia-restricted recognition of allo K/D antigens is required for class I MHC-stimulated mixed lymphocyte responses

The role of Ia molecules in the T cell proliferative response to class I (H2K/D) MHC alloantigens was examined. Proliferation in response to allo-K/D antigenic stimulation, but not to allo-Ia, was markedly inhibited by the addition of monoclonal anti-responder Ia antibodies to cultures in the absence of C. This anti-Ia blocking was observed in responses against both allelic and mutant class I antigens. Partial blocking was observed by using an anti-I-A or anti-I-E monoclonal antibody alone, whereas marked inhibition was seen with these two reagents together when the proliferating cells derived from a responder strain expressing both IA and IE gene products. Syngeneic Ia molecules appear to function as restriction elements, because they are required even in the presence of a source of exogenous second signal, phorbol myristic acetate or IL 1. The K/D-specific response required a responding cell that bears both Lyt-1 and -2 antigens, whereas responses generated to alloantigenic differences, including the I region, require only an Ly-1+ cell. The implications of these data with respect to the repertoire of the alloreactive proliferating T cell and the expression of the Lyt-2 antigen by such cells are discussed.

The role of Ia molecules in the activation of T lymphocytes. II. Ia-restricted recognition of allo K/D antigens is required for class I MHC-stimulated mixed lymphocyte responses

The role of Ia molecules in the T cell proliferative response to class I (H2K/D) MHC alloantigens was examined. Proliferation in response to allo-K/D antigenic stimulation, but not to allo-Ia, was markedly inhibited by the addition of monoclonal anti-responder Ia antibodies to cultures in the absence of C. This anti-Ia blocking was observed in responses against both allelic and mutant class I antigens. Partial blocking was observed by using an anti-I-A or anti-I-E monoclonal antibody alone, whereas marked inhibition was seen with these two reagents together when the proliferating cells derived from a responder strain expressing both IA and IE gene products. Syngeneic Ia molecules appear to function as restriction elements, because they are required even in the presence of a source of exogenous second signal, phorbol myristic acetate or IL 1. The K/D-specific response required a responding cell that bears both Lyt-1 and -2 antigens, whereas responses generated to alloantigenic differences, including the I region, require only an Ly-1+ cell. The implications of these data with respect to the repertoire of the alloreactive proliferating T cell and the expression of the Lyt-2 antigen by such cells are discussed.

Effect of carcinogens and analogs on interferon induction

Pretreatment of mouse embryo fibroblasts with several chemicals, including 7,12-dimethylbenz-(a)-anthracene, 2-aminofluorene, aflatoxin B1, benzo-(a)-pyrene, styrene oxide, and the No. 4 fraction of tobacco smoke condensate, resulted in severely reduced production of interferon when the cells were challenged with Newcastle disease virus. All of the above chemicals are proven or strongly suggested carcinogens. When the analogs methyl methanesulfonate, a potent carcinogen, and ethyl methanesulfonate, a weak carcinogen, were applied to cells, interferon induction was only inhibited by the methyl methanesulfonate. Therefore, carcinogens may directly inhibit the induction of interferon by Newcastle disease virus.

Rod-shaped organism in the liver of a patient with Whipple's disease

Histological review of a liver biopsy from a patient with known Whipple's disease revealed a prominence of Kupffer cells containing PAS-positive granules. Electron microscopy revealed rod-shaped organisms in the Kupffer cells but the presence of these structures were not associated with overt liver injury. This is thought to be the first reported demonstration of these bacillary bodies in this location.