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1.
BMC Musculoskelet Disord ; 23(1): 757, 2022 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-35933372

RESUMO

BACKGROUND: High bone mass (HBM, BMD Z-score ≥ + 3.2) and cam morphology (bulging of lateral femoral head) are associated with greater odds of prevalent radiographic hip osteoarthritis (rHOA). As cam morphology is itself a manifestation of increased bone deposition around the femoral head, it is conceivable that cam morphology may mediate the relationship between HBM and rHOA. We therefore aimed to determine if individuals with HBM have increased odds of prevalent cam morphology. In addition, we investigated whether the relationship between cam and prevalent and incident osteoarthritis was preserved in a HBM population. METHODS: In the HBM study, a UK based cohort of adults with unexplained HBM and their relatives and spouses (controls), we determined the presence of cam morphology using semi-automatic methods of alpha angle derivation from pelvic radiographs. Associations between HBM status and presence of cam morphology, and between cam morphology and presence of rHOA (or its subphenotypes: osteophytes, joint space narrowing, cysts, and subchondral sclerosis) were determined using multivariable logistic regression, adjusting for age, sex, height, weight, and adolescent physical activity levels. The association between cam at baseline and incidence of rHOA after an average of 8 years was determined. Generalised estimating equations accounted for individual-level clustering. RESULTS: The study included 352 individuals, of whom 235 (66.7%) were female and 234 (66.5%) had HBM. Included individuals contributed 694 hips, of which 143 had a cam deformity (20.6%). There was no evidence of an association between HBM and cam morphology (OR = 0.97 [95% CI: 0.63-1.51], p = 0.90) but a strong relationship was observed between cam morphology and rHOA (OR = 3.96 [2.63-5.98], p = 5.46 × 10-11) and rHOA subphenotypes joint space narrowing (OR = 3.70 [2.48-5.54], p = 1.76 × 10-10), subchondral sclerosis (OR = 3.28 [1.60-6.60], p = 9.57 × 10-4) and osteophytes (OR = 3.01 [1.87-4.87], p = 6.37 × 10-6). Cam morphology was not associated with incident osteoarthritis (OR = 0.76 [0.16-3.49], p = 0.72). CONCLUSIONS: The relationship between cam morphology and rHOA seen in other studies is preserved in a HBM population. This study suggests that the risk of OA conferred by high BMD and by cam morphology are mediated via distinct pathways.


Assuntos
Osteoartrite do Quadril , Osteófito , Adolescente , Adulto , Estudos de Coortes , Feminino , Articulação do Quadril/diagnóstico por imagem , Articulação do Quadril/patologia , Humanos , Masculino , Osteoartrite do Quadril/diagnóstico por imagem , Osteoartrite do Quadril/epidemiologia , Osteoartrite do Quadril/patologia , Osteófito/diagnóstico por imagem , Osteófito/epidemiologia , Osteófito/patologia , Radiografia , Esclerose/patologia
2.
Osteoarthritis Cartilage ; 28(9): 1180-1190, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32417557

RESUMO

OBJECTIVE: High bone mass (HBM) is associated with an increased prevalence of radiographic knee OA (kOA), characterized by osteophytosis. We aimed to determine if progression of radiographic kOA, and its sub-phenotypes, is increased in HBM and whether observed changes are clinically relevant. DESIGN: A cohort with and without HBM (L1 and/or total hip bone mineral density Z-score≥+3.2) had knee radiographs collected at baseline and 8-year follow-up. Sub-phenotypes were graded using the OARSI atlas. Medial/lateral tibial/femoral osteophyte and medial/lateral joint space narrowing (JSN) grades were summed and Δosteophytes, ΔJSN derived. Pain, function and stiffness were quantified using the WOMAC questionnaire. Associations between HBM status and sub-phenotype progression were determined using multivariable linear/poisson regression, adjusting for age, sex, height, baseline sub-phenotype grade, menopause, education and total body fat mass (TBFM). Generalized estimating equations accounted for individual-level clustering. RESULTS: 169 individuals had repeated radiographs, providing 330 knee images; 63% had HBM, 73% were female, mean (SD) age was 58 (12) years. Whilst HBM was not clearly associated with overall Kellgren-Lawrence measured progression (RR = 1.55 [0.56.4.32]), HBM was positively associated with both Δosteophytes and ΔJSN individually (adjusted mean differences between individuals with and without HBM 0.45 [0.01.0.89] and 0.15 [0.01.0.29], respectively). HBM individuals had higher WOMAC knee pain scores (ß = 7.42 [1.17.13.66]), largely explained by adjustment for osteophyte score (58% attenuated) rather than JSN (30% attenuated) or TBFM (16% attenuated). The same pattern was observed for symptomatic stiffness and functional limitation. CONCLUSIONS: HBM is associated with osteophyte progression, which appears to contribute to increased reported pain, stiffness and functional loss.


Assuntos
Densidade Óssea , Osteoartrite do Joelho/diagnóstico por imagem , Osteófito/diagnóstico por imagem , Absorciometria de Fóton , Atividades Cotidianas , Tecido Adiposo , Idoso , Artralgia/fisiopatologia , Peso Corporal , Estudos de Coortes , Progressão da Doença , Feminino , Seguimentos , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Osteoartrite do Joelho/fisiopatologia , Osteófito/fisiopatologia , Radiografia
3.
Osteoporos Int ; 30(5): 939-948, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30671611

RESUMO

Mini Abstract: Pregnancy-associated osteoporosis (PAO) is a rare syndrome affecting women during late pregnancy and the early postpartum period. We set out to review the clinical features of ten cases of PAO from a single UK centre. Patients had attended the Royal National Hospital for Rheumatic Diseases, Bath (RNHRD) between January 2000 and June 2016. The principal criterion for inclusion was the occurrence of low trauma fractures either during pregnancy or the immediate post-partum period. Data were obtained from retrospective review of medical notes. Bone mineral density (BMD) was measured using dual-energy X-ray absorptiometry (Hologic ®Discovery system) at the lumbar spine and hip. Data pertaining to the pregnancy, as well as type and duration of treatment received, were reviewed. All ten cases presented with vertebral fractures. In four patients, no risk factors for fracture other than pregnancy or breastfeeding could be identified. Four patients were found to have vitamin D insufficiency at the time of diagnosis, and a further two patients had received treatment with low molecular weight heparin (LMWH). In one case, further investigation led to a diagnosis of osteogenesis imperfecta (OI) confirmed on genetic testing. In terms of treatment, eight out of the ten patients in this series received a bisphosphonate, most commonly risedronate due to its relatively short skeletal retention time. Clinicians should be aware of PAO, a rare but recognised complication of pregnancy. The condition should be especially considered in women presenting with new onset back pain in pregnancy or the postpartum period.


Assuntos
Osteoporose/diagnóstico , Complicações na Gravidez/diagnóstico , Absorciometria de Fóton , Adulto , Dor nas Costas/etiologia , Densidade Óssea/fisiologia , Conservadores da Densidade Óssea/uso terapêutico , Feminino , Humanos , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Osteoporose/tratamento farmacológico , Osteoporose/fisiopatologia , Fraturas por Osteoporose/complicações , Fraturas por Osteoporose/diagnóstico por imagem , Fraturas por Osteoporose/tratamento farmacológico , Fraturas por Osteoporose/fisiopatologia , Gravidez , Complicações na Gravidez/tratamento farmacológico , Complicações na Gravidez/fisiopatologia , Transtornos Puerperais/diagnóstico , Transtornos Puerperais/tratamento farmacológico , Transtornos Puerperais/fisiopatologia , Estudos Retrospectivos , Fraturas da Coluna Vertebral/complicações , Fraturas da Coluna Vertebral/diagnóstico por imagem , Fraturas da Coluna Vertebral/tratamento farmacológico , Fraturas da Coluna Vertebral/fisiopatologia , Adulto Jovem
4.
Artigo em Inglês | MEDLINE | ID: mdl-28337818

RESUMO

The purpose of the current study was to explore colorectal cancer survivors' information and support needs in relation to health concerns and health behaviour change. Face-to-face interviews were conducted with participants who had completed active treatment for cancer within the previous 2 years. Participants were colorectal cancer survivors (N = 24, men = 11, women = 13 M, age = 69.38 years, SD = 4.19) recruited from a hospital in Perth, Australia on the basis that they had existing morbidities that put them at increased risk of cardiovascular disease. Interview transcripts were analysed using thematic analysis. RESULTS: Five main themes emerged: bowel changes; Lack of knowledge concerning healthy eating and physical activity; conflicting information; desire for support; and, need for simple messages and strategies to stay healthy. Where dietary recommendations were provided, these were to resolve bowel problems rather than to promote healthy eating. The provision of lifestyle advice from the oncologists is limited and patients' lack knowledge of guidelines for diet and physical activity. Oncologists could provide patients with clear messages from the World Cancer Research Fund (); that is to increase physical activity and dietary fibre and reduce consumption of red meat, processed meat, alcohol and body fatness.


Assuntos
Sobreviventes de Câncer , Dieta , Exercício Físico , Comportamentos Relacionados com a Saúde , Necessidades e Demandas de Serviços de Saúde , Avaliação das Necessidades , Idoso , Sobreviventes de Câncer/psicologia , Neoplasias do Colo , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Estilo de Vida , Masculino , Pessoa de Meia-Idade
5.
Scand J Med Sci Sports ; 25(6): e655-63, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25441263

RESUMO

This study was a preliminarily investigation into the prevention of unintentional doping on the basis of self-determination theory (SDT). Specifically, we examined the relationship between athletes' motives for doping avoidance and their behavior when offered an unfamiliar food product. Participants were young Australian athletes (n = 410) that were offered a free lollipop prior to completing a questionnaire. It was noted whether participants refused to take or eat the lollipop and whether they read the ingredients of the lollipop. The questionnaire assessed autonomous and controlled forms of motivation, amotivation, doping intentions, and adherence regarding doping avoidance behaviors. The results showed that young athletes who adopted controlled reasons to avoid doping in sport (e.g., not getting caught) tended to report higher adherence to behaviors related to avoiding and monitoring banned substances, whereas those who adopted autonomous reasons (e.g., anti-doping being consistent with life goals) appeared to be more willing to read the ingredients of the provided food. The significant interaction effect between autonomous and controlled motivation indicated that autonomous motivation was more predictive to doping intention for athletes with low controlled motivation. It is concluded that SDT may help understand the motivational processes of the prevention of unintentional doping in sport.


Assuntos
Atletas/psicologia , Dopagem Esportivo/psicologia , Conhecimentos, Atitudes e Prática em Saúde , Motivação , Autonomia Pessoal , Adolescente , Doces , Dopagem Esportivo/prevenção & controle , Comportamento Alimentar , Feminino , Rotulagem de Alimentos , Humanos , Intenção , Masculino , Teoria Psicológica , Inquéritos e Questionários , Adulto Jovem
6.
Osteoarthritis Cartilage ; 22(8): 1120-8, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24971870

RESUMO

OBJECTIVE: Epidemiological studies have shown an association between increased bone mineral density (BMD) and osteoarthritis (OA), but whether this represents cause or effect remains unclear. In this study, we used a novel approach to investigate this question, determining whether individuals with High Bone Mass (HBM) have a higher prevalence of radiographic hip OA compared with controls. DESIGN: HBM cases came from the UK-based HBM study: HBM was defined by BMD Z-score. Unaffected relatives of index cases were recruited as family controls. Age-stratified random sampling was used to select further population controls from the Chingford and Hertfordshire cohort studies. Pelvic radiographs were pooled and assessed by a single observer blinded to case-control status. Analyses used logistic regression, adjusted for age, gender and body mass index (BMI). RESULTS: 530 HBM hips in 272 cases (mean age 62.9 years, 74% female) and 1702 control hips in 863 controls (mean age 64.8 years, 84% female) were analysed. The prevalence of radiographic OA, defined as Croft score ≥3, was higher in cases compared with controls (20.0% vs 13.6%), with adjusted odds ratio (OR) [95% CI] 1.52 [1.09, 2.11], P = 0.013. Osteophytes (OR 2.12 [1.61, 2.79], P < 0.001) and subchondral sclerosis (OR 2.78 [1.49, 5.18], P = 0.001) were more prevalent in cases. However, no difference in the prevalence of joint space narrowing (JSN) was seen (OR 0.97 [0.72, 1.33], P = 0.869). CONCLUSIONS: An increased prevalence of radiographic hip OA and osteophytosis was observed in HBM cases compared with controls, in keeping with a positive association between HBM and OA and suggesting that OA in HBM has a hypertrophic phenotype.


Assuntos
Densidade Óssea , Doenças Ósseas Metabólicas/epidemiologia , Articulação do Quadril/diagnóstico por imagem , Osteoartrite do Quadril/epidemiologia , Osteófito/epidemiologia , Absorciometria de Fóton , Idoso , Doenças Ósseas Metabólicas/diagnóstico por imagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Osteoartrite do Quadril/diagnóstico por imagem , Osteófito/diagnóstico por imagem , Prevalência , Reino Unido/epidemiologia
7.
Disabil Rehabil ; : 1-12, 2023 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-37698010

RESUMO

PURPOSE: To explore the literature on carer-supported home-based exercise programs for people after stroke, as a form of physical activity. The review focus was to examine the training carers receive, the content of programs, and investigate the physical activity levels and functional mobility of people after stroke. MATERIALS AND METHODS: A scoping review was undertaken, guided by Joanna Briggs Institute methodology. The concept of home-based carer-supported exercise, in people after stroke, was searched across five databases. Outcomes of interest were physical activity levels and functional mobility. RESULTS: We screened 2285 references and included 10 studies: one systematic review, five randomised controlled trials, one trial with non-equivalent control, and four uncontrolled studies. Carer training ranged from one to twelve sessions. Exercise interventions commonly including walking, other whole body functional exercises and balance activities. In eight studies interventions were in addition to standard care. Five studies reported significant between-group differences for functional mobility, favouring the intervention. One study reported physical activity levels. CONCLUSION: There was large variation in the volume and content of training provided to carers. Physical activity levels were infrequently objectively reported. Future studies should include greater details on their protocols to allow for replication and implementation into clinical practice.


Carer-supported home-based exercises may improve functional mobility once home after a stroke.The optimal length, content, and model of delivery of carer training, so carers can provide better targeted home-based exercise support to people after stroke, is not known.Better monitoring of participation in home-based exercise and reporting of short and long-term physical activity is needed.

8.
Scand J Med Sci Sports ; 22(5): 596-606, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21392123

RESUMO

The protection of the health of athletes is one of the three criteria taken into account when registering a substance in the World Anti-Doping Agency prohibited list. Nevertheless, in elite-level cycling, banned substance use is widespread. The present research adopted a psychological approach to examine how or whether perceived health risks influence elite-level cyclists' decisions to use banned substances. Sixteen semi-structured interviews were conducted with cyclists hoping to join a professional team (n=6), neo-professional cyclists (n=2), and former professional cyclists (n=8). Although an evolution was observed in the organization of doping and perceptions of doping over the last decade, the perceived health hazards did not influence, most of the time, decisions to use banned substances among the sample of cyclists. There was a systematization of exogenous substance use in the cycling environment and a trivialization of the side effects of the banned substances. Finally, younger cyclists were not concerned about the long-term health consequences of banned substances; they were more focused on the short-term performance-enhancing benefits. There is a need to implement more effective preventive programs to change athletes' attitudes toward doping and its health risks.


Assuntos
Ciclismo/fisiologia , Dopagem Esportivo/psicologia , Nível de Saúde , Substâncias para Melhoria do Desempenho , Segurança , Ciclismo/psicologia , Comportamento Competitivo , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Entrevista Psicológica , Masculino , Pesquisa Qualitativa , Suíça , Adulto Jovem
9.
Bone ; 97: 306-313, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28082078

RESUMO

OBJECTIVES: High Bone Mass (HBM) is associated with (a) radiographic knee osteoarthritis (OA), partly mediated by increased BMI, and (b) pelvic enthesophytes and hip osteophytes, suggestive of a bone-forming phenotype. We aimed to establish whether HBM is associated with radiographic features of OA in non-weight-bearing (hand) joints, and whether such OA demonstrates a bone-forming phenotype. METHODS: HBM cases (BMD Z-scores≥+3.2) were compared with family controls. A blinded assessor graded all PA hand radiographs for: osteophytes (0-3), joint space narrowing (JSN) (0-3), subchondral sclerosis (0-1), at the index Distal Interphalangeal Joint (DIPJ) and 1st Carpometacarpal Joint (CMCJ), using an established atlas. Analyses used a random effects logistic regression model, adjusting a priori for age and gender. Mediating roles of BMI and bone turnover markers (BTMs) were explored by further adjustment. RESULTS: 314 HBM cases (mean age 61.1years, 74% female) and 183 controls (54.3years, 46% female) were included. Osteophytes (grade≥1) were more common in HBM (DIPJ: 67% vs. 45%, CMCJ: 69% vs. 50%), with adjusted OR [95% CI] 1.82 [1.11, 2.97], p=0.017 and 1.89 [1.19, 3.01], p=0.007 respectively; no differences were seen in JSN. Further adjustment for BMI failed to attenuate ORs for osteophytes in HBM cases vs. controls; DIPJ 1.72 [1.05, 2.83], p=0.032, CMCJ 1.76 [1.00, 3.06], p=0.049. Adjustment for BTMs (concentrations lower amongst HBM cases) did not attenuate ORs. CONCLUSIONS: HBM is positively associated with OA in non-weight-bearing joints, independent of BMI. HBM-associated OA is characterised by osteophytes, consistent with a bone-forming phenotype, rather than JSN reflecting cartilage loss. Systemic factors (e.g. genetic architecture) which govern HBM may also increase bone-forming OA risk.


Assuntos
Índice de Massa Corporal , Osso e Ossos/patologia , Osso e Ossos/fisiopatologia , Articulações/patologia , Articulações/fisiopatologia , Osteogênese , Osso e Ossos/diagnóstico por imagem , Demografia , Feminino , Humanos , Articulações/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Tamanho do Órgão , Osteoartrite/diagnóstico por imagem , Osteoartrite/patologia , Osteoartrite/fisiopatologia , Suporte de Carga
10.
J Sci Med Sport ; 18(3): 315-22, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-24793786

RESUMO

OBJECTIVES: Motivation in sport has been frequently identified as a key factor of young athletes' intention of doping in sport, but there has not been any attempt in scrutinizing the motivational mechanism involved. The present study applied the trans-contextual model of motivation to explain the relationship between motivation in a sport context and motivation and the social-cognitive factors (attitude, subjective norm, perceived behavioral control, and intention) from the theory of planned behavior (TPB) in an anti-doping context. DESIGN: A cross-sectional survey was conducted. METHODS: Questionnaire data was collected from 410 elite and sub-elite young athletes in Australia (Mean age [17.7±3.9 yr], 55.4% male, Years in sport [9.1±3.2]). We measured the key model variables of study in relation to sport motivation (Behavioral Regulation in Sport Questionnaire), and the motivation (adapted version of the Treatment Self-Regulation Questionnaire) and social cognitive patterns (the theory of planned behavior questionnaire) of doping avoidance. The data was analyzed by variance-based structural equation modeling with bootstrapping of 999 replications. RESULTS: The goodness-of-fit of the hypothesized model was acceptable. The bootstrapped parameter estimates revealed that autonomous motivation and amotivation in sport were positively associated with the corresponding types of motivation for the avoidance of doping. Autonomous motivation, subjective norm, and perceived behavioral control in doping avoidance fully mediated the relationship between autonomous motivation in sport and intention for doping avoidance. CONCLUSIONS: The findings support the tenets of the trans-contextual model, and explain how motivation in sport is related to athletes' motivation and intention with respect to anti-doping behaviors.


Assuntos
Desempenho Atlético/psicologia , Dopagem Esportivo/psicologia , Motivação , Autonomia Pessoal , Esportes/psicologia , Adolescente , Atitude , Aprendizagem da Esquiva , Comportamento de Escolha , Estudos Transversais , Feminino , Humanos , Intenção , Masculino , Modelos Psicológicos , Adulto Jovem
11.
Bone ; 71: 171-9, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25445455

RESUMO

We previously reported an association between high bone mass (HBM) and a bone-forming phenotype of radiographic hip osteoarthritis (OA). As knee and hip OA have distinct risk factors, in this study we aimed to determine (i) whether HBM is also associated with knee OA, and (ii) whether the HBM knee OA phenotype demonstrates a similar pattern of radiographic features to that observed at the hip. HBM cases (defined by DXA BMD Z-scores) from the UK-based HBM study were compared with unaffected family controls and general population controls from the Chingford and Hertfordshire cohort studies. A single blinded observer graded AP weight-bearing knee radiographs for features of OA (Kellgren-Lawrence score, osteophytes, joint space narrowing (JSN), sclerosis) using an atlas. Analyses used logistic regression, adjusting a priori for age and gender, and additionally for BMI as a potential mediator of the HBM-OA association, using Stata v12. 609 HBM knees in 311 cases (mean age 60.8years, 74% female) and 1937 control knees in 991 controls (63.4years, 81% female) were analysed. The prevalence of radiographic knee OA, defined as Kellgren-Lawrence grade≥2, was increased in cases (31.5% vs. 20.9%), with age and gender adjusted OR [95% CI] 2.38 [1.81, 3.14], p<0.001. The association between HBM and osteophytosis was stronger than that for JSN, both before and after adjustment for BMI which attenuated the ORs for knee OA and osteophytes in cases vs. controls by approximately 50%. Our findings support a positive association between HBM and knee OA. This association was strongest for osteophytes, suggesting HBM confers a general predisposition to a subtype of OA characterised by increased bone formation.


Assuntos
Osso e Ossos/patologia , Osteoartrite do Joelho/diagnóstico por imagem , Osteoartrite do Joelho/epidemiologia , Idoso , Índice de Massa Corporal , Estudos de Casos e Controles , Demografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Tamanho do Órgão , Prevalência , Radiografia , Análise de Regressão , Reino Unido/epidemiologia
12.
Neuroreport ; 3(11): 965-8, 1992 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-1482765

RESUMO

We present the first comparative study of the uptake of metal ions by neurons, performed for Zn, Cr, Co, Mo, Al, Ni, Mn and Cd. The study reveals substantial differences in the uptake of different metals, under similar exposure procedures. In particular, we found very large uptakes for aluminium and molybdenum. We also found significant effects of excitatory substances, in particular kainate, as stimulants of uptake of some of the metals.


Assuntos
Metais/metabolismo , Neurônios/metabolismo , Animais , Metais/análise , Ratos , Espectrometria por Raios X , Tomografia Computadorizada de Emissão de Fóton Único
13.
Health Psychol Behav Med ; 2(1): 565-601, 2014 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-25750803

RESUMO

Self-determination theory has been applied to the prediction of a number of health-related behaviors with self-determined or autonomous forms of motivation generally more effective in predicting health behavior than non-self-determined or controlled forms. Research has been confined to examining the motivational predictors in single health behaviors rather than comparing effects across multiple behaviors. The present study addressed this gap in the literature by testing the relative contribution of autonomous and controlling motivation to the prediction of a large number of health-related behaviors, and examining individual differences in self-determined motivation as a moderator of the effects of autonomous and controlling motivation on health behavior. Participants were undergraduate students (N = 140) who completed measures of autonomous and controlled motivational regulations and behavioral intention for 20 health-related behaviors at an initial occasion with follow-up behavioral measures taken four weeks later. Path analysis was used to test a process model for each behavior in which motivational regulations predicted behavior mediated by intentions. Some minor idiosyncratic findings aside, between-participants analyses revealed significant effects for autonomous motivational regulations on intentions and behavior across the 20 behaviors. Effects for controlled motivation on intentions and behavior were relatively modest by comparison. Intentions mediated the effect of autonomous motivation on behavior. Within-participants analyses were used to segregate the sample into individuals who based their intentions on autonomous motivation (autonomy-oriented) and controlled motivation (control-oriented). Replicating the between-participants path analyses for the process model in the autonomy- and control-oriented samples did not alter the relative effects of the motivational orientations on intention and behavior. Results provide evidence for consistent effects of autonomous motivation on intentions and behavior across multiple health-related behaviors with little evidence of moderation by individual differences. Findings have implications for the generalizability of proposed effects in self-determination theory and intentions as a mediator of distal motivational factors on health-related behavior.

14.
Auto Immun Highlights ; 4(3): 69-80, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26000145

RESUMO

Maintenance of health and physiological homeostasis is a synergistic process involving tight regulation of proteins, transcription factors and other molecular processes. The immune system consists of innate and adaptive immune cells that are required to sustain immunity. The presence of pathogens and tumour cells activates innate immune cells, in particular Natural Killer (NK) cells. Stochastic expression of NK receptors activates either inhibitory or activating signals and results in cytokine production and activation of pathways that result in apoptosis of target cells. Thus, NK cells are a necessary component of the immunological process and aberrations in their functional processes, including equivocal levels of NK cells and cytotoxic activity pre-empts recurrent viral infections, autoimmune diseases and altered inflammatory responses. NK cells are implicated in a number of diseases including chronic fatigue syndrome (CFS). The purpose of this review is to highlight the different profiles of NK cells reported in CFS patients and to determine the extent of NK immune dysfunction in subtypes of CFS patients based on severity in symptoms.

15.
S Afr Med J ; 66(9): 345-6, 1984 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-6474304

RESUMO

A 17-year-old Coloured youth presented at Tygerberg Hospital on six occasions between 1978 and 1981. He was admitted three times for meningococcal meningitis and three times for a meningitic illness clinically suggestive thereof. He had been admitted twice before to the City Hospital, Cape Town, in 1966 and 1968, for presumed meningococcal meningitis. He was fully evaluated in the outpatient department and found to have no detectable total haemolytic complement activity. There was no evidence of classic or alternative pathway activation. He has been tentatively designated as having a deficiency in the C6 or C8 components of the terminal membrane attack mechanism of the complement cascade.


Assuntos
Proteínas do Sistema Complemento/análise , Meningite Meningocócica/imunologia , Adolescente , Complemento C3/análise , Complemento C4/análise , Humanos , Masculino , Recidiva
16.
S Afr Med J ; 66(25): 959-60, 1984.
Artigo em Inglês | MEDLINE | ID: mdl-6440298

RESUMO

Interstitial pulmonary fibrosis and bullae are uncommon findings in neurofibromatosis. A case of this disease with pulmonary parenchymal involvement is presented and the association between the two is discussed.


Assuntos
Pneumopatias/complicações , Neurofibromatose 1/complicações , Fibrose Pulmonar/complicações , Humanos , Masculino , Pessoa de Meia-Idade
17.
S Afr Med J ; 66(7): 273-4, 1984 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-6463806

RESUMO

A 31-year-old Coloured man was admitted to Tygerberg Hospital in 1981 with hoarseness, hyperkeratotic skin lesions and nodules on the eyelids. There was a history of an episode of loss of consciousness. Skull radiographs demonstrated bilateral symmetrical calcifications in the temporal region. Skin biopsy was consistent with a diagnosis of lipoid proteinosis.


Assuntos
Rouquidão/complicações , Lipidoses/patologia , Proteinose Lipoide de Urbach e Wiethe/patologia , Adulto , Calcinose/diagnóstico por imagem , Humanos , Proteinose Lipoide de Urbach e Wiethe/etiologia , Masculino , Radiografia , Pele/patologia , Crânio/diagnóstico por imagem
18.
Am Ind Hyg Assoc J ; 53(6): 387-94, 1992 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-1605111

RESUMO

A study was conducted in a fluorspar milling plant to assess the effectiveness of tracer gases as a reliable supplement to conventional air-monitoring and ventilation measurements. In the course of this study, a tracer gas was used as a surrogate substance to analyze the direction and the rate of spread of contaminants from various potential dust production points in the plant. Time-weighted average and continuous mineral dust concentrations were measured in several areas of the plant; these results were compared and correlated with steady-state tracer gas concentrations in the mill. Time-weighted average dust concentrations varied between 0.18 and 0.57 mg/m3 for total dust and 0.04 and 0.20 mg/m3 for quartz respirable dust, depending on the location. Correlation of these values with steady-state tracer gas concentrations yielded linear relationships with correlation coefficients (R2) of 0.95 and 0.87, respectively, for total and quartz dust. Results from this study, therefore, indicate that tracer gases may help model the spread of airborne respirable dust from point sources. These tracer gas releases also allowed the simultaneous quantitative determination of air residence times and contaminant clearance times from the building. Hence, tracer gases will help industrial hygienists obtain useful data with respect to building ventilation.


Assuntos
Poluentes Ocupacionais do Ar/análise , Fluoreto de Cálcio/análise , Poeira/análise , Monitoramento Ambiental/métodos , Hexafluoreto de Enxofre , Ventilação/normas , Monitoramento Ambiental/instrumentação , Estudos de Avaliação como Assunto , Humanos
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