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1.
Occup Med (Lond) ; 74(3): 211-217, 2024 05 09.
Article in English | MEDLINE | ID: mdl-38319824

ABSTRACT

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has presented immense challenges to health systems worldwide and significantly impacted the mental health of frontline healthcare workers. AIMS: This study drew on the experiences of frontline healthcare workers to examine organizational strategies needed to support the mental health and well-being of healthcare workers during times of crisis. METHODS: Semi-structured focus groups or individual interviews were conducted with healthcare workers to examine their perspectives on organizational strategies for enhancing staff mental health and well-being during crises. Data were analysed thematically. Following this, evidence for the identified strategies was reviewed to assess alignment with participant views and recommendations. RESULTS: Thirty-two healthcare workers from diverse disciplines (10 allied health, 11 nursing, 11 medical) participated in the study. Data analysis identified three broad themes contributing to supporting mental health and well-being. These themes can be encapsulated as the 'Three Cs'-culture (building an organizational culture that prioritizes mental health); conditions (implementing proactive organizational strategies during crises) and care (ensuring fit-for-purpose strategies to support mental health and well-being). CONCLUSIONS: Study findings underscore the necessity of an integrated and systemic organizational approach to address mental health and well-being in the healthcare workplace. This approach must be long term with the components of the 'Three Cs', particularly cultural change and conditions, viewed as a part of a suite of strategies to ensure crisis preparedness. It is imperative that organizations collaborate with their staff, providing support and fostering a safe and inclusive work environment that ultimately benefits patients, their care and staff well-being.


Subject(s)
COVID-19 , Focus Groups , Health Personnel , Mental Health , Organizational Culture , SARS-CoV-2 , Humans , COVID-19/prevention & control , COVID-19/epidemiology , Health Personnel/psychology , Female , Male , Adult , Middle Aged , Pandemics , Qualitative Research , Workplace/psychology
2.
Public Health ; 206: 70-76, 2022 May.
Article in English | MEDLINE | ID: mdl-35398610

ABSTRACT

OBJECTIVES: The aim of this paper is to identify possible regulatory, policy and program measures to address gambling harm to bingo players and their communities, and in doing so extend existing public health approaches to gambling to better include bingo. STUDY DESIGN: This was a qualitative case study of three populations in Victoria, Australia where bingo was popular and structural disadvantage common: Indigenous people in the state's east, Pacific people in the north and older people on low or fixed incomes in the capital, Melbourne. METHODS: Our study investigated experiences of bingo, including gambling harm and recommendations for change. Data were generated through interviews with 53 bingo players and 13 stakeholders as well as 12 participant observations of bingo sessions. RESULTS: Five broad drivers of and influences on harm to bingo players are identified: technological, regulatory and commercial changes eroding bingo's protective factors; bingo being used to bolster other forms of gambling; promotion of gambling interests over people's wellbeing; not recognising experiences of different communities and; external structural influences such as racialised poverty. We identify recommendations from bingo players and stakeholders to address harm arising from bingo involving wagering. Based on these recommendations and available evidence, we propose five sets of measures to mitigate against gambling harm to bingo players and their communities, and so extend existing public health approaches to gambling to better encompass bingo. These sets of measures are: safeguarding bingo's protective features; delinking bingo from the gambling eco-system; dismantling political protection of the gambling industry; tailoring strategies for sub-populations and preventing oppression and abuse. CONCLUSIONS: In the face of significant regulatory, commercial and technological changes to bingo that risk increasing and intensifying harm, a public health approach to bingo could help mitigate gambling harm.


Subject(s)
Gambling , Aged , Gambling/prevention & control , Humans , Public Health , Qualitative Research , Victoria
3.
Article in English | MEDLINE | ID: mdl-30104426

ABSTRACT

Behavioural and cognitive processes play important roles in mediating an individual's interactions with its environment. Yet, while there is a vast literature on repeatable individual differences in behaviour, relatively little is known about the repeatability of cognitive performance. To further our understanding of the evolution of cognition, we gathered 44 studies on individual performance of 25 species across six animal classes and used meta-analysis to assess whether cognitive performance is repeatable. We compared repeatability (R) in performance (1) on the same task presented at different times (temporal repeatability), and (2) on different tasks that measured the same putative cognitive ability (contextual repeatability). We also addressed whether R estimates were influenced by seven extrinsic factors (moderators): type of cognitive performance measurement, type of cognitive task, delay between tests, origin of the subjects, experimental context, taxonomic class and publication status. We found support for both temporal and contextual repeatability of cognitive performance, with mean R estimates ranging between 0.15 and 0.28. Repeatability estimates were mostly influenced by the type of cognitive performance measures and publication status. Our findings highlight the widespread occurrence of consistent inter-individual variation in cognition across a range of taxa which, like behaviour, may be associated with fitness outcomes.This article is part of the theme issue 'Causes and consequences of individual differences in cognitive abilities'.


Subject(s)
Behavior, Animal , Biological Variation, Individual , Cognition , Animals
5.
J Hosp Infect ; 97(3): 301-309, 2017 Nov.
Article in English | MEDLINE | ID: mdl-28558954

ABSTRACT

BACKGROUND: Clinical diagnostic sensitivity alone is inadequate in the diagnosis of influenza. Polymerase chain reaction (PCR) testing is sensitive but the inherent delays in result availability potentially prolong time to isolation and treatment. Until recently no near-patient test (NPT) has demonstrated adequate sensitivity for routine clinical use. AIM: To evaluate diagnostic accuracy, time to result availability, clinical impact, and cost consequences of Alere™ i Influenza A&B NPT (Alere Inc., Waltham, MA, USA) using off-label throat swabs. METHODS: Prospective, multi-centre [four UK National Health Service (NHS) hospitals], diagnostic accuracy cohort study with cost modelling. Throat swab samples from suspected influenza patients were tested for influenza using the reference standard of PCR; a second throat swab was tested using NPT. FINDINGS: A total of 827 participants were recruited; 589 were suitable for analysis: sensitivity was 75.8% [95% confidence interval (CI): 67.0-84.6]; specificity was 96.8% (95% CI: 95.2-98.3). Sensitivity varied between Sheffield (Northern General Hospital: 82.1%; Royal Hallamshire Hospital: 83.3%) and other sites (Doncaster Royal Infirmary: 71.4%; Newcastle's Royal Victoria Infirmary: 50.0%) whereas specificity was high (92-100%). Positive predictive value (PPV) was 81.2% (95% CI: 72.9-89.5) with negative predictive value 95.6% (95% CI: 93.9-97.4) with observed prevalence of 15.4%. Median time to result for PCR was 1.1 days (on-site laboratories) and 5.2 days (remote laboratories). Isolation findings: 75% influenza positive not isolated; 69% of isolated participants did not have influenza. For a cohort of 1000 participants, annual estimated non-diagnostic cost savings with NPT are £215,040. CONCLUSION: This first prospective study of the Alere i NPT using throat swabs demonstrates high specificity, high PPV during seasonal epidemics, and rapid result availability which could lead to substantial cost savings.


Subject(s)
Costs and Cost Analysis , Diagnostic Tests, Routine/economics , Diagnostic Tests, Routine/methods , Influenza, Human/diagnosis , Pharynx/virology , Point-of-Care Testing/economics , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Predictive Value of Tests , Prospective Studies , Sensitivity and Specificity , Time Factors , United Kingdom , Young Adult
6.
J R Coll Physicians Edinb ; 40(2): 145-7; quiz 148, 2010 Jun.
Article in English | MEDLINE | ID: mdl-21125060

ABSTRACT

Anaphylaxis is the quintessential medical emergency where prompt recognition and treatment is life-saving. In the UK the incidence is increasing year on year, and is most common in the sixth and seventh decades of life. More than half of cases are iatrogenic in nature, most of the rest are caused by venom (stings) and food substances. The clinical signs can be subtle, but an acute onset of skin or mucosal oedema with respiratory compromise or reduced blood pressure should alert the physician to the diagnosis. The management revolves around the use of adrenaline after an initial airway, breathing and circulation approach, in a dose of 0.5 mg 1:1,000 intramuscularly, repeated five minutes later if there has been no response. Any delay in treatment is associated with increased risk of adverse outcome. Steroids and antihistamines are often given, although there is no convincing evidence of their effect in the acute setting. Where diagnostic uncertainty arises, serum tryptase levels can confirm or refute the diagnosis.


Subject(s)
Anaphylaxis/diagnosis , Anaphylaxis/therapy , Anaphylaxis/etiology , Biomarkers/blood , Bites and Stings/complications , Diagnosis, Differential , Epinephrine/administration & dosage , Histamine Antagonists/administration & dosage , Humans , Iatrogenic Disease , Steroids/administration & dosage , Tryptases/blood
7.
Environ Entomol ; 37(2): 546-54, 2008 Apr.
Article in English | MEDLINE | ID: mdl-18419928

ABSTRACT

Mounting evidence suggests that pollinators worldwide are experiencing dramatic population declines, and exposure to pesticides is one of the factors that can account for this. By making use of a database containing more than two decades of honey bee (Apis mellifera) hive poisoning incidents from the United Kingdom (Wildlife Incident Investigation Scheme [WIIS]) and corresponding pesticide use surveys, we attempted to explain honey bee poisoning incidents in the field using models derived from pesticide use information, laboratory-generated bee toxicity data (defined as a hazard ratio; application rate divided by LD(50)), and physico-chemical properties of the applied pesticides. Logistic regression analyses were used to assess the relationship between honey bee poisoning incidents in the field and these parameters. In analyzing models with multiple dimensions, we selected the best model by the best subset method, an iterative method based on maximum likelihood estimation, and Akaike's information criterion. Results suggested that the size of the area treated and hazard ratios calculated from application rates and oral or contact toxicity (but the latter especially) can be used to predict the likelihood that honey bee mortality will occur. Model predictions also suggest that some insecticides carry an extreme risk for bees, despite the lack of documented incidents.


Subject(s)
Bees/drug effects , Environmental Monitoring/methods , Insecticides/toxicity , Animals , Environmental Pollutants/toxicity , Risk
9.
Ann Emerg Med ; 37(6): 587-601, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11385327

ABSTRACT

STUDY OBJECTIVE: The task force assessed the needs, demands, feasibility, and content of training for US civilian emergency medical responders (paramedics, nurses, and physicians) for nuclear/biological/chemical (NBC) terrorism. METHODS: A task force representing key professional organizations, stakeholders, and disciplines involved in emergency medical response conducted an iterated instructional-design analysis on the feasibility and content of such training with input from educational professionals. We then analyzed 6 previously developed training courses for their congruence with our recommendations. RESULTS: The task force produced descriptions of learning groups, content and learning objectives, and barriers and challenges to NBC education. Access to training and sustainment of learning (retention of knowledge) represent the significant barriers. The courses analyzed by the task force did not meet all objectives and challenges addressed. CONCLUSION: The task force recommends training programs and materials need to be developed to overcome the identified barriers and challenges to learning for these audiences. Furthermore, the task force recommends incorporating NBC training into standard training programs for emergency medical professionals.


Subject(s)
Bioterrorism , Chemical Warfare , Clinical Competence/standards , Curriculum/standards , Emergency Medical Technicians/education , Emergency Medicine/education , Emergency Nursing/education , Guidelines as Topic , Inservice Training/organization & administration , Medical Staff, Hospital/education , Needs Assessment/organization & administration , Nursing Staff, Hospital/education , Radiation Injuries/therapy , Education, Continuing/organization & administration , Feasibility Studies , Humans , Organizational Objectives , Program Development , United States
10.
Biotech Histochem ; 75(6): 251-8, 2000 Nov.
Article in English | MEDLINE | ID: mdl-11131565

ABSTRACT

The in vitro radiolabeled methyl incorporation assay, a commonly used technique to evaluate global methylation of DNA, has some disadvantages and limitations. The purpose of the present study was to compare the results of global DNA methylation evaluated by radiolabeled methyl incorporation (CPM/microg of DNA) with immunohistochemical staining of the same tissue sections with a monoclonal antibody developed against 5-methylcytosine used (5-mc). We archival specimens of squamous cell cancer (SCC) of the human lung with a matched uninvolved specimen (n = 18 pairs) and 18 lung specimens from subjects without lung cancer (noncancer specimens) to make this comparison. The immunostaining for 5-mc was reported as a percentage of cells positive for staining as well as a weighted average of the intensity score. The results suggested that both radiolabeled methyl incorporation assay and immunostaining for 5-mc can be used to demonstrate hypomethylation of DNA in SCC tissues compared to matched uninvolved tissues. An advantage of immunostaining, however, is its ability to demonstrate hypomethylation of SCC compared to adjacent bronchial mucosa on the same archival specimen, obviating the need to use sections from both SCC and matched uninvolved tissues. Only by using the immunostaining technique were we able to document a statistically significant difference in DNA methylation between SCC and noncancer tissues. We conclude that the immunostaining technique has advantages over the radiolabeled methyl incorporation assay and may be best suited for evaluation of global DNA methylation when the methylation status of cancer cannot be normalized by methyl incorporation of normal tissues or when the number of samples available for evaluation is small.


Subject(s)
Biological Assay/methods , DNA Methylation , DNA, Neoplasm/analysis , 5-Methylcytosine , Carcinoma, Squamous Cell/genetics , Carcinoma, Squamous Cell/pathology , Cytosine/analogs & derivatives , Cytosine/immunology , Humans , Immunoenzyme Techniques/methods , Isotope Labeling , Lung/pathology , Lung Neoplasms/genetics , Lung Neoplasms/pathology , Tritium
11.
Anticancer Res ; 20(3A): 1751-7, 2000.
Article in English | MEDLINE | ID: mdl-10928104

ABSTRACT

Although cervical cancer is a common female cancer, little attention has been given to genetic susceptibility factors. The present case-control study was undertaken to examine MTHFR polymorphism as a potential molecular marker of cervical intraepithelial neoplasia (CIN) susceptibility and to relate the findings to smoking, HPV infection, ethnicity, parity and oral contraceptive use, which are known risk factors for cervical cancer. A base change from C to T at the nucleotide position 677 of the MTHFR gene results in substitution of valine (GTC) for alanine (GCC). The homozygous normal (Ala/Ala), homozygous mutant (Val/Val), and heterozygous mutant (Ala/Val) genotypes for the MTHFR gene were determined in cervical tissues of 64 cases of CIN lesions and 31 controls. The genotype frequencies of both Val/Val (17%) and Ala/Val (56%) were significantly higher in subjects with CIN lesions compared to controls with Val/Val (10%) and Ala/Val (39%), (trend p = 0.03). The results suggested a significantly increased CIN risk with an alanine to valine substitution at amino acid 223 of MTHFR with an odds ratio of 2.9 (95% confidence interval: 1.2-7.9, p = 0.02). Age, ethnicity, smoking and oral contraceptive use were weakly and nonsignificantly associated with CIN risk. HPV infection was associated with a statistically nonsignificant threefold increase in CIN risk. Parity and MTHFR genotype displayed a strong interaction. Neither nulliparous women with MTHFR polymorphism nor parous women without the polymorphism were at higher risk than women who did not have children and were MTHFR homozygous normal (the reference category). Women with mutant MTHFR genotype who had children, however, showed a significantly higher risk of CIN, with an odds ratio of 23 (95% confidence interval: 2.3-225) as compared to the reference category. No other factors displayed such a strong pattern of interaction. Since MTHFR polymorphism and pregnancy increases folate requirements and can impair folate status, this association could reflect an inadequate response of mutant MTHFR genotype carriers to the increased demand for folate imposed by pregnancy. Tissue folate deficiency, in turn, could increase the risk of CIN in the affected women.


Subject(s)
Oxidoreductases Acting on CH-NH Group Donors/genetics , Polymorphism, Genetic , Uterine Cervical Dysplasia/genetics , Adult , Female , Gene Frequency , Genetic Markers , Genetic Predisposition to Disease , Genetic Testing , Humans , Life Style , Methylenetetrahydrofolate Reductase (NADPH2) , Risk Factors , Uterine Cervical Dysplasia/epidemiology , Uterine Cervical Dysplasia/ethnology
12.
J Autoimmun ; 15(1): 21-32, 2000 Aug.
Article in English | MEDLINE | ID: mdl-10936025

ABSTRACT

Apoptotic-cell-bound beta2-glycoprotein I (beta2GPI), but not apoptotic cells or beta2GPI alone, can induce the production of anti-phospholipid (anti-PL) antibodies (Ab) in normal mice. Although it is presumed that beta2GPI binds to anionic phospholipid (PL) exposed on the apoptotic cell membrane, the precise nature of this complex and its immunogenicity is unclear. To address these issues, we investigated the structure and immunogenicity of human beta2GPI in the presence of different PL that may be expressed on the surface of apoptotic cells. BALB/c mice were immunized intravenously (iv) with beta2GPI in the presence of cardiolipin (CL), phosphatidylglycerol (PG), phosphatidylserine (PS), phosphatidylcholine (PC), or PS/PC (25%/75%) vesicles. Cardiolipin+beta2GPI induced the highest levels of anti-beta2GPI and anti-CL IgG Ab and lupus anticoagulant (LA) activity, while beta2GPI with PC or PS/PC vesicles produced no significant anti-PL Ab. PS+beta2GPI was somewhat immunogenic, but less so than PG+beta2GPI. beta2GPI was immunogenic in the presence of native (CL(N)), but not hydrogenated (CL(H)), CL. Circular dichroism analysis demonstrated that the structure of beta2GPI was altered specifically by interaction with CL(N), but not other anionic PL, including CL(H). Similarly, the structure of CL(N)was affected by interaction with beta2GPI, as detected by(31)P nuclear magnetic resonance. These findings demonstrate that beta2GPI complexed with CL(N)is structurally altered, highly immunogenic, and induces the production of IgG anti-PL Ab. Furthermore, the structural modification and the generation of immunogenic epitopes on beta2GPI upon interaction with CL(N)require the presence of unsaturated fatty acid chains, suggesting a role for oxidation in this process.


Subject(s)
Antibodies, Antiphospholipid/biosynthesis , Glycoproteins/immunology , Glycoproteins/metabolism , Membrane Glycoproteins/immunology , Membrane Glycoproteins/metabolism , Phospholipids/immunology , Phospholipids/metabolism , Adjuvants, Immunologic/administration & dosage , Animals , Apoptosis/immunology , Cardiolipins/administration & dosage , Cardiolipins/immunology , Circular Dichroism , Female , Glycoproteins/administration & dosage , Humans , Immunoglobulin G/biosynthesis , Immunoglobulin G/classification , Injections, Intravenous , Injections, Subcutaneous , Macromolecular Substances , Membrane Glycoproteins/administration & dosage , Mice , Mice, Inbred BALB C , Nuclear Magnetic Resonance, Biomolecular , Phospholipids/administration & dosage , beta 2-Glycoprotein I
13.
Nutr Cancer ; 37(1): 99-107, 2000.
Article in English | MEDLINE | ID: mdl-10965526

ABSTRACT

We measured the concentrations of folate and vitamin B-12 in paired tissue samples of squamous cell cancer (SCC) and adjacent grossly normal-appearing uninvolved bronchial mucosa (from which SCC developed and also "at risk" of developing SCC) of the lung in 12 subjects to determine the involvement of these vitamins in 1) lung carcinogenesis and 2) global DNA methylation. The folate concentrations were significantly lower in SCCs than in uninvolved tissues (p = 0.03). The vitamin B-12 concentrations were also significantly lower in SCCs than in uninvolved tissues (p = 0.02). The radiolabeled methyl incorporation (inversely related to the degree of in vivo DNA methylation) was significantly higher in SCCs than in uninvolved tissues (p < 0.0001). The correlation between folate and radiolabeled methyl incorporation was inverse and statistically significant in SCCs (p = 0.03). The correlation between vitamin B-12 and radiolabeled methyl incorporation also was inverse and statistically significant in SCCs (p = 0.009). The relationship between tissue vitamin B-12 and DNA methylation was minimal in uninvolved tissues. The relationship between folate and DNA methylation, however, was inverse in uninvolved tissues. In the multiple regression models that included both vitamins, only folate was inversely associated with radiolabeled methyl incorporation in uninvolved and cancerous tissues. These results suggested that folate might be the limiting vitamin for proper DNA methylation in SCC as well as in tissues at risk of developing SCC. Several possible mechanisms of folate deficiency, including inactivation of the vitamin by exposure to carcinogens of cigarette smoke and underexpression or absence of folate receptor in SCCs and associated premalignant lesions, are discussed in light of these findings.


Subject(s)
Carcinoma, Squamous Cell/metabolism , DNA Methylation , Folic Acid Deficiency/metabolism , Lung Neoplasms/metabolism , Vitamin B 12 Deficiency/metabolism , Aged , Aged, 80 and over , DNA Methylation/drug effects , Folic Acid/pharmacology , Folic Acid Deficiency/physiopathology , Humans , Middle Aged , Smoking/adverse effects , Statistics as Topic , Vitamin B 12/pharmacology , Vitamin B 12 Deficiency/physiopathology
14.
J Fam Psychol ; 14(1): 5-26, 2000 Mar.
Article in English | MEDLINE | ID: mdl-10740679

ABSTRACT

A model-based meta-analytic review highlighted relationships critical for understanding the young child's postdivorce adjustment when planning parenting arrangements. This review confirmed the utility of an interactional model that includes preseparation information and information about father, mother, and the parental alliance. Interactions among the quality and frequency of father's involvement in relation to postdivorce child adjustment that were not clear in studies looking only at direct effects of father-access variables were identified. Results indicated that maternal variables should not be viewed in isolation from the parental alliance or from the father-child relationship. The review discusses variables promoting developmental competence as well as risk factors that clearly interfere with both parental and child functioning.


Subject(s)
Adaptation, Psychological , Divorce/psychology , Parent-Child Relations , Child , Child Custody , Child, Preschool , Female , Humans , Male , Parenting/psychology
15.
Neuroscience ; 96(1): 181-94, 2000.
Article in English | MEDLINE | ID: mdl-10683422

ABSTRACT

We have reported previously that axonal degeneration in specific brain regions occurs in rats infected with the parasite Trypanosoma brucei. These degenerative changes occur in spatiotemporal association with over-expression of pro-inflammatory cytokine messenger RNAs in the brain. To test how aspirin-like anti-inflammatory drugs might alter the disease process, we fed trypanosome-infected rats with 200mg/kg of sodium salicylate (the first metabolite of aspirin) daily in their drinking water. Sodium salicylate treatment in uninfected rats did not cause any neural damage. However, sodium salicylate treatment greatly exacerbated neurodegeneration in trypanosome-infected rats, resulting in extensive terminal and neuronal cell body degeneration in the cortex, hippocampus, striatum, thalamus, and anterior olfactory nucleus. The exaggerated neurodegeneration, which occurred in late stages of infection, was temporally and somewhat spatially associated with a late-appearing enhancement of messenger RNA expression of interleukin-1beta, interleukin-1beta converting enzyme, tumor necrosis factor-alpha, and inhibitory factor kappaBalpha in the brain parenchyma. Restricted areas showed elevations in messenger RNA expression of interleukin-1 receptor antagonist, interleukin-6, inducible nitric oxide synthase, interferon-gamma, and inducible cyclooxygenase. The association suggests that increased production of pro-inflammatory cytokines in the brain may be an underlying mechanism for neural damage induced by the chronic sodium salicylate treatment. Furthermore, the results reveal a serious complication in using aspirin-like drugs for the treatment of trypanosome infection.


Subject(s)
Brain/drug effects , Brain/pathology , Nerve Degeneration/pathology , Sodium Salicylate/pharmacology , Trypanosoma brucei brucei , Trypanosomiasis, African/pathology , Animals , Blood-Brain Barrier/drug effects , Brain/metabolism , Cytokines/genetics , In Situ Hybridization , Male , RNA, Messenger/metabolism , Rats , Rats, Sprague-Dawley , Time Factors , Trypanosomiasis, African/metabolism
16.
J Comp Neurol ; 414(1): 114-30, 1999 Nov 08.
Article in English | MEDLINE | ID: mdl-10494082

ABSTRACT

Overproduction of proinflammatory cytokines in the brains of transgenic animals causes brain pathology. To investigate the relationship between brain cytokines and pathology in the brains of animals with adult-onset, pathophysiologically induced brain cytokine expression, we studied rats infected with the parasite Trypanosoma brucei. Several weeks after infection, in situ hybridization histochemistry showed a pattern of chronic overexpression of the mRNAs for proinflammatory cytokines interleukin-1beta and tumor necrosis factor-alpha in the brains of the animals. Similar spatiotemporal inductions of mRNAs for inhibitory factor kappaBalpha and interleukin-1beta converting enzyme were found and quantified. The mRNAs for inducible nitric oxide synthase and interleukin-1 receptor antagonist were highly localized to the choroid plexus, which showed evidence of structural abnormalities associated with the parasites' presence there. The mRNAs for interleukin-6, interferon-gamma, and inducible cyclooxygenase showed restricted induction patterns. Another set of animals was processed for degeneration-induced silver staining, TdT-mediated dUTP-digoxigenin nick end-labeling (TUNEL) staining, glial fibrillary acidic protein (GFAP) immunohistochemistry, and several other histological markers. Apoptosis of scattered small cells and degeneration of certain nerve fibers was found in patterns spatially related to the cytokine mRNA patterns and to cerebrospinal fluid diffusion pathways. Furthermore, striking cytoarchitectonically defined clusters of degenerating non-neuronal cells, probably astrocytes, were found. The results reveal chronic overexpression of potentially cytotoxic cytokines in the brain and selective histopathology patterns in this natural disease model. J. Comp. Neurol. 414:114-130, 1999. Published 1999 Wiley-Liss, Inc.


Subject(s)
Brain/metabolism , Cytokines/genetics , Gene Expression Regulation/physiology , Inflammation/metabolism , Trypanosoma brucei brucei/isolation & purification , Trypanosomiasis, African/metabolism , Animals , Apoptosis/physiology , Astrocytes/metabolism , Astrocytes/pathology , Brain/pathology , I-kappa B Proteins/genetics , In Situ Hybridization , Inflammation/pathology , Male , Nerve Degeneration , Phenotype , Rats , Rats, Sprague-Dawley , Silver Staining , Trypanosomiasis, African/pathology
17.
J Neuroimmunol ; 93(1-2): 72-80, 1999 Jan 01.
Article in English | MEDLINE | ID: mdl-10378870

ABSTRACT

Although it is generally accepted that pro-inflammatory cytokines produced by cells of the central nervous system play important roles in the communication between the central nervous system and the immune system during sepsis, it is not clear whether these cytokines are produced in the brain under subseptic conditions. In this study, we used in situ hybridization to examine the mRNA expression of the pro-inflammatory cytokines IL-1beta and TNFalpha in the brains of rats 2 and 12 h after they were challenged by peripheral injections of lipopolysaccharide (LPS) ranging from 0.01 to 1000 microg/kg. Unlike septic doses of LPS (> 500 microg/kg), which induce global expression of pro-inflammatory cytokines in the brain, subseptic doses of LPS (0.01-10 microg/kg) induced IL-1beta and TNFalpha mRNA expression only in the choroid plexus, the circumventricular organs, and meninges. The expression of the cytokine-responsive immediate early gene I kappaB alpha was induced in the brain after doses of LPS as low as 0.1 microg/kg. I kappaB alpha mRNA expression was confined to sites where IL-1beta and TNFalpha were expressed. These results indicate that the induction and action of pro-inflammatory cytokines during subseptic infection occur at the blood-brain barrier and at circumventricular organs, which may be sites for elaboration of signal molecules that communicate peripheral immune status to the brain.


Subject(s)
Brain/immunology , Encephalitis/immunology , Interleukin-1/genetics , Lipopolysaccharides/pharmacology , Tumor Necrosis Factor-alpha/genetics , Animals , Autoradiography , Brain/enzymology , Caspase 1/immunology , Caspase 1/metabolism , Encephalitis/chemically induced , Encephalitis/metabolism , Gene Expression Regulation, Enzymologic/drug effects , Gene Expression Regulation, Enzymologic/immunology , Injections, Intravenous , Interleukin-1/immunology , Male , Paraventricular Hypothalamic Nucleus/chemistry , Paraventricular Hypothalamic Nucleus/enzymology , Paraventricular Hypothalamic Nucleus/immunology , Proto-Oncogene Proteins c-fos/genetics , Proto-Oncogene Proteins c-fos/immunology , RNA, Messenger/metabolism , Rats , Rats, Sprague-Dawley , Receptors, Interleukin-1/antagonists & inhibitors , Receptors, Interleukin-1/immunology , Solitary Nucleus/chemistry , Solitary Nucleus/enzymology , Solitary Nucleus/immunology , Subfornical Organ/chemistry , Subfornical Organ/enzymology , Subfornical Organ/immunology , Tumor Necrosis Factor-alpha/immunology
18.
J Neuroendocrinol ; 11(2): 115-20, 1999 Feb.
Article in English | MEDLINE | ID: mdl-10048466

ABSTRACT

Systemically administered lipopolysaccharide (LPS) elicits profound changes in pituitary hormone secretion. Pro-inflammatory cytokines have been proposed as mediators of these responses. In this study, we used in-situ hybridization histochemistry to investigate LPS-induced cytokine gene expression in the rat pituitary. After i.p. or i.v. injection of various doses of LPS, mRNA for the immediate-early gene IkappaBu (an inhibitor of NF-kappaB, a transcription factor that regulates the expression of many pro-inflammatory cytokines) was induced in the anterior lobe as early as 0.5 h. The induced IkappaBalpha mRNA expression peaked at 1 h. In the posterior lobe, IkappaBalpha mRNA was first induced at 0.5 h and peaked at 2 h. A similar spatiotemporal pattern of interleukin-1b (IL-1) mRNA induction was observed. In addition, at 2 h after injection, TNFalpha, IL-1beta converting enzyme (ICE), and IL-1 receptor antagonist (IL-1RA) mRNAs were induced in both anterior and posterior lobes. Type 1 IL-1 receptor (IL-1R1) mRNA was constitutively expressed in the pituitary, and its expression level did not change after the LPS injection. Interestingly, the mRNA coding for glial fibrillary acidic protein (GFAP), an astrocyte marker, was selectively induced in the posterior lobe at 2 h after LPS injection, suggesting that LPS affects pituicyte function. Together, these results suggest that LPS acts directly on the pituitary to rapidly induce cytokine expression. Locally synthesized cytokines may activate cytokine receptor bearing cells to modulate the endocrine activities of the pituitary.


Subject(s)
Cytokines/genetics , Gene Expression Regulation, Enzymologic/drug effects , I-kappa B Proteins , Lipopolysaccharides/pharmacology , Pituitary Gland/enzymology , Transcription, Genetic/physiology , Adrenocorticotropic Hormone/blood , Animals , Caspase 1/genetics , Corticosterone/blood , DNA-Binding Proteins/genetics , Glial Fibrillary Acidic Protein/genetics , Interleukin 1 Receptor Antagonist Protein , Interleukin-1/genetics , Male , NF-KappaB Inhibitor alpha , Pituitary Gland/immunology , RNA, Messenger/metabolism , Rats , Rats, Sprague-Dawley , Sialoglycoproteins/genetics , Transcription, Genetic/drug effects , Tumor Necrosis Factor-alpha/genetics
20.
Brain Res Bull ; 46(6): 495-503, 1998 Aug.
Article in English | MEDLINE | ID: mdl-9744286

ABSTRACT

This study examined the role of the area postrema (AP) in transducing peripheral immune signals, represented by intravenous (i.v.) interleukin-1beta (IL-1), into neuroendocrine responses. The AP, a circumventricular organ with a leaky blood-brain barrier, lies adjacent to the nucleus of the solitary tract (NTS) in the medulla. The AP was removed by aspiration, and 2 weeks later, AP-lesioned or sham-lesioned rats were injected i.v. with 0.5 microg/kg IL-1 or sterile saline. After 30 min, brains were removed and analyzed for c-fos mRNA levels in various structures implicated in the hypothalamic-pituitary-adrenal axis response to peripheral cytokine challenge. The sham-lesioned animals responded to IL-1 with large elevations in adrenocorticotropic hormone (ACTH) and corticosterone levels in the plasma and c-fos mRNA levels in cells of the AP, NTS, central nucleus of the amygdala, bed nucleus of the stria terminalis, hypothalamic paraventricular nucleus (PVN), and meninges. Prior AP removal abolished the IL-1 -induced increases in ACTH and corticosterone in the plasma and c-fos mRNA levels in the NTS and PVN. However, AP removal had no effect on IL-1-induced increases in c-fos mRNA levels in the other areas examined. The selective AP lesion effects suggest that the AP and adjacent NTS play a pivotal role in transducing a circulating IL-1 signal into hypothalamic-pituitary-adrenal axis activation by a pathway that may be comprised of known anatomical links between the AP, NTS, and corticotropin-releasing hormone neurons of the PVN.


Subject(s)
Hypothalamo-Hypophyseal System/physiology , Interleukin-1/pharmacology , Paraventricular Hypothalamic Nucleus/chemistry , Pituitary-Adrenal System/physiology , Proto-Oncogene Proteins c-fos/genetics , Adrenocorticotropic Hormone/metabolism , Amygdala/chemistry , Animals , Brain Chemistry/drug effects , Cerebral Ventricles/blood supply , Cerebral Ventricles/surgery , Corticosterone/metabolism , Gene Expression/physiology , Hypothalamo-Hypophyseal System/drug effects , In Situ Hybridization , Injections, Intravenous , Interleukin-1/physiology , Male , Paraventricular Hypothalamic Nucleus/physiology , Pituitary-Adrenal System/drug effects , RNA, Messenger/metabolism , Rats , Rats, Sprague-Dawley , Septal Nuclei/chemistry , Signal Transduction/physiology , Solitary Nucleus/physiology
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