991 resultados para Androgen Levels
Resumo:
Erythropoiesis is maintained by the hormone erythropoietin (Epo) binding to its cognate receptor (EpoR) on erythroid progenitor cells. The Epo-EpoR interaction initiates a signal transduction process that regulates the survival, growth and differentiation of these cells. Originally perceived as highly lineage-restricted, Epo is now recognised to have pleiotropic effects extending beyond the maintenance of red cell mass. Functional interactions between Epo and EpoR have been demonstrated in numerous cells and tissues. EpoR expression on neoplastic cells leads to concern that recombinant human erythropoietin, used to treat anaemia in cancer patients, may augment tumour growth. Here we demonstrate that EPO, at pharmacological concentrations, can activate three major signalling cascades, viz. the Jak2/STAT5, Ras/ERK and PI3K/Akt pathways in non-small cell lung carcinoma (NSCLC) cell lines. EpoR synthesis is normally under the control of GATA-1, but NSCLC cells exhibit decreased GATA-1 levels compared to GATA-2, -3 and -6, suggesting that GATA-1 is not essential for EpoR production. The increased Epo-induced signalling was not associated with a growth advantage for the NSCLC cells.
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Aim: This paper reports a study on how men cope with the side-effects of radiotherapy and neo-adjuvant androgen deprivation for prostate cancer up to 1 year after treatment.
Background: With early detection and improved treatments, prostate cancer survivors are living longer with the disease and the side-effects of treatment. How they cope affects their long-term physical and mental health.
Design: A prospective, longitudinal, exploratory design using both qualitative and quantitative methods was used in this study.
Method: Between September 2006–September 2007 149 men who were about to undergo radical radiotherapy ± androgen deprivation for localized prostate cancer in Northern Ireland were recruited to the study. They completed the Brief Cope scale at four time-points.
Results: Acceptance, positive reframing, emotional support, planning and, just getting on with it, were the most common ways of coping. Fewer men used coping strategies less at 6 months and 1 year after radiotherapy in comparison to pre-treatment and 4–6 weeks after radiotherapy. Interviews with these men demonstrated that men adapted to a new norm, with the support of their wives/partners and did not readily seek professional help. A minority of men used alcohol, behavioural disengagement and self blame as ways of coping.
Conclusion: Men used a variety of ways of coping to help them deal with radiotherapy and neo-adjuvant androgen deprivation for up to 12 months after radiotherapy. Interventions need to be developed to take account of the specific needs of partners of men with prostate cancer and single men who have prostate cancer.
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Russia has very high mortality from cardiovascular disease (CVD), with evidence that heavy drinking may play a role. To throw further light on this association we have studied the association of alcohol with predictors of CVD risk including B-type natriuretic peptide (BNP). Levels of BNP increase primarily in response to abnormal cardiac chamber wall stretch which can occur both as a result of atherosclerosis as well as due to other types of damage to the myocardium. No previous population-based studies have investigated the association with alcohol. We analysed cross-sectional data on drinking behaviour in 993 men aged 25-60 years from the Izhevsk Family Study 2 (IFS2), conducted in the Russian city of Izhevsk in 2008-2009. Relative to non-drinkers, men who drank hazardously had an odds ratio (OR) of being in the top 20 % of the BNP distribution of 4.66 (95 % CI 2.13, 10.19) adjusted for age, obesity, waist-hip ratio, and smoking. Further adjustment for class of hypertension resulted in only slight attenuation of the effect, suggesting that this effect was not secondary to the influence of alcohol on blood pressure. In contrast hazardous drinking was associated with markedly raised ApoA1 and HDL cholesterol levels, but had little impact on levels of ApoB and LDL cholesterol. Similar but less pronounced associations were found in the Belfast (UK) component of the PRIME study conducted in 1991. These findings suggest that the association of heavy drinking with increased risk of cardiovascular disease may be partly due to alcohol-induced non-atherosclerotic damage to the myocardium.
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The acquisition of high quality, well-dated local site records is essential for progressing regional environmental reconstructions. As part of a wider study designed to examine intra- and extra- site ecosystem responses to environmental change, this paper presents new palaeoecological data from the floodplain of the River Torne in the Humberhead Levels, South Yorkshire. The sampling site lies adjacent to the lowland raised mire of Hatfield Moors, a location with a long history of palaeoecological investigations. The potential of using floodplain records to reconstruct local variations in ecosystem response to environmental change is also considered. Coleoptera and pollen are used to reconstruct floodplain ecosystem dynamics, whilst chronologies are established using Bayesian age–depth modelling. Between 10,200 cal BP and 2300 cal BP, the floodplain experienced multiple phases of ecological change. At 10,200–9910 cal BP, a cut-off channel began to infill with peat, while the surrounding floodplain remained relatively dry with Pinus forest growing nearby. Between 9630–9500 cal BP and 7270–7020 cal BP, a depositional hiatus occurred in the sedimentary record. By the end of this period, the local woodland had diversified and expanded to mixed deciduous tree cover. A wet shift identified at 6870–6160 cal BP was shortly followed by a rise in Alnus and Tilia from 6410–6160 cal BP. At this time, widespread floodplain paludification had occurred in the Humberhead Levels, which was largely controlled by relative sea-level (RSL) rise and the associated rise in regional water tables. Floodplain expansion also resulted in the widespread occurrence of Alnus dominated fen woodland. The local Torne floodplain experienced varying levels of wetness that influenced the decline and subsequent regeneration of the woodland from 5870–5640 cal BP. At this time, the Ulmus decline is identified in the pollen stratigraphic record. Floodplain hydrology appears to have been controlled by a combination of water table fluctuations and changes in channel pattern/flow, both of which can be linked to RSL variations recorded in the Humber Estuary. Floodplain alluviation, also linked to rising water tables, is dated to 4360–4160 cal BP. Anthropogenic woodland clearance further upstream may have further compounded this event.
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Teachers’ communication of musical knowledge through physical gesture represents a valuable pedagogical field in need of investigation. This exploratory case study compares the gestural behaviour of three piano teachers while giving individual lessons to students who differed according to piano proficiency levels. The data was collected by video recordings of one-to-one piano lessons and gestures were categorized using two gesture classifications: the spontaneous co-verbal gesture classification (McNeill, 1992; 2005) and spontaneous co-musical gesture classification (Simones, Schroeder & Rodger, 2013). Poisson regression analysis and qualitative observation suggest a relationship between teachers’ didactic intentions and the types of gesture they produced while teaching, as shown by differences in gestural category frequency between teaching students of higher and lower levels of proficiency. Such reported agreement between teachers’ gestural approach in relation to student proficiency levels indicates a teachers’ gestural scaffolding approach whereby teachers adapted gestural communicative channels to suit students’ specific conceptual skill levels.
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Patulin (PAT) is a mycotoxin produced by various species of fungi, with Penicillium expansum being the most commonly occurring. Apples and apple products are the main sources of PAT contamination. This mycotoxin has been shown to induce toxic effects in animals, a few of which include reproductive toxicity and interference with the endocrine system. Here the endocrine disrupting potential of PAT has been investigated in vitro to identify disruption at the level of oestrogen, androgen, progestagen and glucocorticoid nuclear receptor transcriptional activity, and to assess interferences in estradiol, testosterone and progesterone steroid hormone production. At the receptor level, 0.5-5000ng/ml (0.0032-32μM) PAT did not appear to induce any specific (ant) agonistic responses in reporter gene assays (RGAs); however, nuclear transcriptional activity was affected. A >6 fold increase in the glucocorticoid receptor transcriptional activity was observed following treatment with 5000ng/ml PAT in the presence of cortisol. At the hormone production level, despite cytotoxicity being observed after treatment with 5000ng/ml PAT, estradiol levels had increased >2 fold. At 500ng/ml PAT treatment, an increase in progesterone and a decrease in testosterone production were observed. The findings of this study could be considered in assessing the health risks following exposure to PAT.
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Research investigating the association between negative symptoms and plasma cortisol levels in individuals with schizophrenia has produced inconsistent findings. This study investigated whether deficit syndrome schizophrenia (characterized by high levels of primary negative symptoms) is associated with comparatively high morning plasma cortisol levels, more negative appraisals about illness and higher levels of depression. Participants were 85 individuals diagnosed with schizophrenia and 85 individuals with no history of contact with psychiatric services matched for age and gender. All participants provided fasting 9.00 a.m. plasma cortisol samples. There were no significant differences between the schizophrenia and control participants in plasma cortisol levels. The Proximal Deficit Syndrome method was used to identify individuals with deficit syndrome schizophrenia. Contrary to what had been hypothesized, participants with deficit syndrome schizophrenia had significantly lower plasma cortisol levels than both non-deficit syndrome participants and control participants. Participants with the deficit syndrome reported significantly less negative appraisals about illness (assessed by PBIQ) and lower levels of depression (assessed by BDI-II). Differences in cortisol levels continued to trend toward significance when levels of depression were controlled for. The patterns of illness-related appraisals and plasma cortisol levels raise the possibility that the deficit syndrome could be a form of adaptation syndrome.
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The aim of this study was to assess the effect of providing environmental enrichment in the form of perches and string on the behaviour and welfare of commercial broiler chickens. Houses containing ~23 000 broiler chickens were assigned to one of four treatments in a 2×2 factorial design. Treatments involved two levels of access to perches (P) (present (24/house) ‘+P’ or absent ‘−P’) and two levels of access to string (S) (present (24/house) ‘+S’ or absent ‘−S’). All houses contained windows, and 30 straw bales were provided from day 10 of the rearing cycle. Treatments were applied in one of four houses on a single farm, and were replicated over four production cycles. Behaviour and leg health were observed in weeks 3 to 5 of the rearing cycle. Production performance and environmental parameters were also measured. There was an interaction between perches and age in the percentage of birds observed lying, with higher percentages of birds observed lying in the +P treatment than in the −P treatment during weeks 4 and 5. There was also a significant interaction between string and age in the percentage of birds observed in locomotion, with higher percentages observed in locomotion in the −S treatment than in the +S treatment during weeks 4 and 5. There was also an interaction between string and age in average gait scores, with lower gait scores in the +S treatment than in the −S treatment during weeks 3 and 5 but not within week 4. Daytime observations showed that perches and strings were used frequently, with one bout of perching occurring approximately every 80 s/perch, and one bout of pecking at string occurring every 78 s/string on average. There was a significant effect of age on use of perches (P<0.001) and string (P<0.001), with perching peaking during week 5 and string pecking peaking during week 3. We conclude that commercial broilers in windowed houses with access to straw bales display an interest in additional enrichment stimuli in the form of perches and string, and therefore that these stimuli have the potential to improve welfare. In addition, provision of string as a pecking device appeared to positively influence walking ability. However, this effect was numerically small, was only shown in certain weeks and was not reflected in the other leg health measure (latency to lie). The results also showed an apparent negative effect of string and perches on the activity levels of birds (recorded away from the immediate vicinity of these enrichments) towards the end of the production cycle. These results emphasise the need for further research into optimum design and layout of enrichment stimuli for modern broilers in windowed houses to ensure that their provision leads to clear welfare benefits.
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In a large scale survey of rice grains from markets (13 countries) and fields (6 countries), a total of 1578 rice grain samples were analysed for lead. From the market collected samples, only 0.6% of the samples exceeded the Chinese and EU limit of 0.2 μg g− 1 lead in rice (when excluding samples collected from known contaminated/mine impacted regions). When evaluating the rice grain samples against the Food and Drug Administration's (FDA) provisional total tolerable intake (PTTI) values for children and pregnant women, it was found that only people consuming large quantities of rice were at risk of exceeding the PTTI from rice alone. Furthermore, 6 field experiments were conducted to evaluate the proportion of the variation in lead concentration in rice grains due to genetics. A total of 4 of the 6 field experiments had significant differences between genotypes, but when the genotypes common across all six field sites were assessed, only 4% of the variation was explained by genotype, with 9.5% and 11% of the variation explained by the environment and genotype by environment interaction respectively. Further work is needed to identify the sources of lead contamination in rice, with detailed information obtained on the locations and environments where the rice is sampled, so that specific risk assessments can be performed.
Resumo:
Background: Chronic kidney disease (CKD) patients on dialysis are prone to vitamin D insufficiency despite oral vitamin D supplementation. Here, we studied whether narrow-band ultraviolet B (NB-UVB) exposures improve vitamin D balance.
Methods: 14 haemodialysis patients and 15 healthy subjects receiving oral cholecalciferol 20 µg daily got nine NB-UVB exposures on the entire body. Serum 25-hydroxyvitamin D (25(OH)D) was measured by radioimmunoassay. Cutaneous mRNA expression levels of CYP27A1 and CYP27B1, two enzymes required for hydroxylation of vitamin D into its active metabolite, were also measured.
Results: The baseline serum 25(OH)D concentration was 57.6 ± 18.2 nmol/l in the CKD patients and 74.3 ± 14.8 nmol/l in the healthy subjects. The NB-UVB course increased serum 25(OH)D by 14.0 nmol/l (95% CI 8.7-19.5) and 17.0 nmol/l (CI 13.7-20.2), respectively. At baseline the CKD patients showed significantly increased CYP27B1 levels compared to the healthy subjects.
Conclusions: A short NB-UVB course is an efficient way to improve vitamin D balance in CKD patients on dialysis who are receiving oral vitamin D supplementation. The increased cutaneous CYP27B1 levels in the CKD patients suggest that the loss of renal activity of this enzyme is at least partially compensated for by the skin.
Resumo:
Chronic kidney disease (CKD) patients are especially prone to vitamin D insufficiency. Narrow-band ultraviolet B (NB-UVB) treatment increases serum 25-hydroxyvitamin D [25(OH)D] in dermatological patients, and we studied whether it also improves vitamin D balance in CKD patients on haemodialysis.
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SCOPE: This study explores the relationship between aflatoxin and the insulin-like growth factor (IGF) axis and its potential effect on child growth.
METHODS AND RESULTS: One hundred and ninety-nine Kenyan schoolchildren were studied for aflatoxin-albumin adduct (AF-alb), IGF1 and IGF-binding protein-3 (IGFBP3) levels using ELISA. AF-alb was inversely associated with IGF1 and IGFBP3 (p < 0.05). Both IGF1 and IGFBP3 were significantly associated with child height and weight (p < 0.01). Children in the highest tertile of AF-alb exposure (>198.5 pg/mg) were shorter than children in the lowest tertile (<74.5 pg/mg), after adjusting for confounders (p = 0.043). Path analysis suggested that IGF1 levels explained ∼16% of the impact of aflatoxin exposure on child height (p = 0.052). To further investigate this putative mechanistic pathway, HHL-16 liver cells (where HHL-16 is human hepatocyte line 16 cells) were treated with aflatoxin B1 (0.5, 5 and 20 μg/mL for 24-48 h). IGF1 and IGFBP3 gene expression measured by quantitative PCR and protein in culture media showed a significant down-regulation of IGF genes and reduced IGF protein levels.
CONCLUSION: Aflatoxin treatment resulted in a significant decrease in IGF gene and protein expression in vitro. IGF protein levels were also lower in children with the highest levels of AFB-alb adducts. The data suggest that aflatoxin-induced changes in IGF protein levels could contribute to growth impairment where aflatoxin exposure is high.
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This paper examines the debate over nursing staff to patient ratios through the lens of Marxist political economy, arguing that the owners and controllers of healthcare in the USA have a vested interest in opposing mandated minimum ratios, while those involved in carrying out nursing care have a vested interest in their implementation, which coincides with the interests of patients. We examine how evidence-based practice articulates with social power, and proceed to interrogate the research methods used to generate evidence for practice, noting that randomised controlled trials are not suitable for evaluating nurse/patient ratios, which means that observational studies are the primary source of evidence. Representatives of nursing managers have used the fact that observational studies, while demonstrating an association between high ratios and poor outcomes, have not established a causal relationship, to support their argument that there is not sufficient evidence for the imposition of mandatory ratios. We argue that the precautionary principle provides firm justification for mandatory ratios, unless and until a causal relationship has been disproved. We conclude that those involved in the generation of evidence have to choose between technical arguments about the inferiority of observational studies, or emphasising their sufficiency in triggering the precautionary principle.