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Chronic Changes (chronic + change)
Selected AbstractsFS07.1 A survey of occupational hand eczema in DenmarkCONTACT DERMATITIS, Issue 3 2004Rikke Skoet Background:, The need for prevention to reduce the number of occupational hand eczema is high. Occupational hand eczema is the most frequently recognised work-related disease in Denmark. Previous findings have shown that almost half of all cases develop a chronic condition with persistent dermatitis, and the annual cost to society is immense. Aims:, The aim of this study was to survey the trends and development of occupational hand eczema in Denmark and thereby help to ensure future successful prevention of chronic disabling occupational hand eczema. Methods:, 758 patients with recognised occupational hand eczema were included prospectively in the period October 2001- November 2002. Data on diagnoses, disease duration, severity, absence from work and occupation was obtained from The Danish National Board of Industrial Injuries and an additional questionnaire was administered by mail. Results:, 621 patients answered the questionnaire (response rate 82%). Irritant contact dermatitis was the most frequent diagnosis and the female/male ratio was 2:1. High prevalence was found in particularly wet occupations. 19 per cent had sick leave more than 5 weeks per year and the mean disease duration was 4.8 years (median 2.1 years). 68.2% had chronic changes. Conclusion:, The results showed a marked gender difference in the pattern of diagnosis and occupation. The impact of occupational hand eczema is still high with prolonged absence from work and a high percentage of chronic disease. The results of the study give important suggestions for future preventive strategies for health authorities. [source] Ghrelin: a new peptide regulating the neurohormonal system, energy homeostasis and glucose metabolismDIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 5 2008Peter Pusztai Abstract Identification of ghrelin started with the discovery of growth hormone secretagogues, continued with the description of ghrelin receptors and ended with the elucidation of the chemical structure of ghrelin. However, several issues concerning the role of ghrelin in physiological and pathophysiological processes are still under investigation. Most of the ghrelin produced in the body is secreted in the stomach, but it is also expressed in the hypothalamus, pituitary, pancreas, intestine, kidney, heart and gonads. Ghrelin stimulates growth hormone secretion via growth hormone secretagogue receptors. Ghrelin secretion in the stomach depends on both acute and chronic changes in nutritional status and energy balance. Current data support the hypothesis that the stomach, in addition to its important role in digestion, not only influences pituitary hormone secretion but, via ghrelin production, it also sends orexigenic (appetite increasing) signals to hypothalamic nuclei involved in the regulation of energy homeostasis. In addition to these main effects, ghrelin influences insulin secretion and glucose metabolism and it may exert potentially important effects on cardiovascular and gastrointestinal functions. Because of its effects on a large number of physiological functions, ghrelin may be involved in the pathomechanism of several human disorders, including disturbances of appetite, energy homeostasis and glucose metabolism. Further research might lead to a better understanding of the pathophysiology of ghrelin and might provide more effective therapy for the above disorders. Copyright © 2008 John Wiley & Sons, Ltd. [source] An increase in HbA1c after percutaneous coronary intervention raises the risk for restenosis in patients without Type 2 diabetes mellitusDIABETIC MEDICINE, Issue 2 2008H. Diedrichs Abstract Aims The influence of dynamic changes in glycated haemoglobin (HbA1c) on restenosis after elective percutaneous coronary intervention (PCI) in patients without diabetes has not been analysed. Therefore, the rate of restenosis was investigated after elective PCI in 101 consecutive patients without diabetes mellitus in relation to dynamic changes of HbA1c levels. Methods Follow-up angiography was performed in all patients 4,6 months after intervention. Results Multivariate analysis demonstrated that the change in HbA1c between first and second coronary angiography was the most powerful metabolic parameter for prediction of restenosis. The odds ratio for restenosis was 3.0 (95% CI 1.0,9.0) for any increase in HbA1c and 1.9 (95% CI 1.1,3.5) for an HbA1c increase of 0.2%. Conclusions Hence, chronic changes in the glucometabolic environment influence the incidence of restenosis after PCI in patients without diabetes. [source] In vitro analysis of intestinal absorption of cadmium and calcium in rainbow trout fed with calcium- and cadmium-supplemented dietsJOURNAL OF FISH BIOLOGY, Issue 3 2006B. Baldisserotto The protective effects of dietary Ca2+ supplementation against Cd accumulation in rainbow trout Oncorhynchus mykiss fed with Cd-contaminated food were evaluated in relation to chronic changes in intestinal absorption rates. The changes were measured ,in vitro'. The control diet contained c. 20 mg Ca2+ g,1 food and 0·25 ,g Cd g,1 food; the experimental diets were supplemented with CaCO3 and Cd(NO3)2·4H2O to levels of 50 mg Ca2+ g,1 food and 300 ,g Cd g,1 food, alone and in combination. The Ca2+ and Cd absorption rates were measured using radiotracers (45Ca, 109Cd) at total Ca2+ and Cd concentrations of 3·0 and 0·12 mmol l,1, respectively in the intestinal saline. Chronically elevated dietary Cd caused a significant increase in Cd absorption rate by up to 10-fold at 30 days in the mid-intestine. The high Ca2+ diet prevented this up-regulation of Cd transport rate. Conversely, intestinal Ca2+ absorption was significantly increased by two- to five-fold by the Ca2+ -supplemented diet at 30 days in both the mid- and posterior intestine, and this effect was eliminated when Cd was simultaneously elevated in the diet. Ca2+ and Cd probably interact at common pathways and transport mechanisms in the intestine, though independent pathways may also exist. [source] Reduced Expression of the KATP Channel Subunit, Kir6.2, is Associated with Decreased Expression of Neuropeptide Y and Agouti-Related Protein in the Hypothalami of Zucker Diabetic Fatty RatsJOURNAL OF NEUROENDOCRINOLOGY, Issue 12 2007A. Gyte The link between obesity and diabetes is not fully understood but there is evidence to suggest that hypothalamic signalling pathways may be involved. The hypothalamic neuropeptides, pro-opiomelanocortin (POMC), neuropeptide Y (NPY) and agouti-related protein (AGRP) are central to the regulation of food intake and have been implicated in glucose homeostasis. Therefore, the expression of these genes was quantified in hypothalami from diabetic Zucker fatty (ZDF) rats and nondiabetic Zucker fatty (ZF) rats at 6, 8, 10 and 14 weeks of age. Although both strains are obese, only ZDF rats develop pancreatic degeneration and diabetes over this time period. In both ZF and ZDF rats, POMC gene expression was decreased in obese versus lean rats at all ages. By contrast, although there was the expected increase in both NPY and AGRP expression in obese 14-week-old ZF rats, the expression of NPY and AGRP was decreased in 6-week-old obese ZDF rats with hyperinsulinaemia and in 14-week-old rats with the additional hyperglycaemia. Therefore, candidate genes involved in glucose, and insulin signalling pathways were examined in obese ZDF rats over this age range. We found that expression of the ATP-sensitive potassium (KATP) channel component, Kir6.2, was decreased in obese ZDF rats and was lower compared to ZF rats in each age group tested. Furthermore, immunofluorescence analysis showed that Kir6.2 protein expression was reduced in the dorsomedial and ventromedial hypothalamic nuclei of 6-week-old prediabetic ZDF rats compared to ZF rats. The Kir6.2 immunofluorescence colocalised with NPY throughout the hypothalamus. The differences in Kir6.2 expression in ZF and ZDF rats mimic those of NPY and AGRP, which could infer that the changes occur in the same neurones. Overall, these data suggest that chronic changes in hypothalamic Kir6.2 expression may be associated with the development of hyperinsulinaemia and hyperglycaemia in ZDF rats. [source] EFFECT OF COPPER ON ALGAL COMMUNITIES FROM OLIGOTROPHIC CALCAREOUS STREAMS1JOURNAL OF PHYCOLOGY, Issue 2 2002Helena Guasch Two sets of experiments were done to quantify the effects of chronic copper exposure on natural peri- phyton in a nonpolluted calcareous river. The results of short-term (up to 6 h exposure) experiments corroborated the significance of pH on copper toxicity. Copper toxicity increased when pH was reduced from 8.6 to 7.7, and this was related to the effect of pH on copper speciation (free copper concentration increased from 0.2% to 2.3% of total copper). Longer term experiments demonstrated that periphyton communities exposed to copper under pH variation (8.2,8.6) were already affected at 10 ,g·L,1 (20,80 ng·L,1 Cu2+) after 12 days of exposure. Copper exposure caused stronger effects on structural (algal biomass and community structure) than on functional (photosynthetic efficiency) parameters of peri- phyton. Changes in community composition included the enhancement of some taxa (Gomphonema gracile), the inhibition of others (Fragilaria capucina and Phormidium sp.), and the appearance of filament malformations (Mougeotia sp.). The results of our study demonstrated that several weeks of exposure to copper (10,20 ,g·L,1) were sufficient to cause chronic changes in the periphyton of oligotrophic calcareous rivers. This degree of copper pollution can be commonly found in the Mediterranean region as a result of agricultural practices and farming activities. [source] Better renal function with enhanced immunosuppression and protocol biopsies after kidney transplantation in childrenPEDIATRIC TRANSPLANTATION, Issue 6 2005Paula Seikku Abstract:, Subclinical rejection may be associated with decreased graft function after renal transplantation (Tx). Detection by protocol biopsies and treatment could thus be important for the long-term prognosis. We have earlier discovered that glomerular filtration rate (GFR) declined in young children during the first 18 months. Consequently, we slightly enhanced and individualized each patient's immunosuppression. This was a retrospective study of 59 pediatric renal Tx patients between 1995 and 2001. The 35 historical controls received triple-therapy of azathioprine, methylprednisolone and cyclosporine. GFR was measured by protocol at discharge, 6 and 18 months, and a core biopsy was obtained at 18 months. The 24 study patients in addition received basiliximab, had GFR measured at 3 and 12 months, and a biopsy taken at 3 months. Based on histology and function, immunosuppression was individually adjusted. The groups were compared for GFR and histology at 18 months after Tx. There were less acute rejection episodes in the study group (0.38 vs. 1.23 per patient) and serum creatinine concentrations were lower. Subclinical rejection was detected and treated in 39% at 3 months. There were more chronic changes in the control (47%) than in the study group (29%) at 18 months. GFR was significantly higher in the study group at 18 months (87 vs. 68 mL/min/1.73 m2), most remarkably in patients ,2 yr of age (99 vs. 68 mL/min/1.73 m2). Detection of subclinical rejection and slightly enhanced and individualized immunosuppression improved GFR 18 months after renal Tx, especially in the youngest patients. [source] Effects of female steroid hormones on A-type K+ currents in murine colonTHE JOURNAL OF PHYSIOLOGY, Issue 2 2006Elizabeth A. H. Beckett Idiopathic constipation is higher in women of reproductive age than postmenopausal women or men, suggesting that female steroid hormones influence gastrointestinal motility. How female hormones affect motility is unclear. Colonic motility is regulated by ion channels in colonic myocytes. Voltage-dependent K+ channels serve to set the excitability of colonic muscles. We investigated regulation of Kv4.3 channel expression in response to acute or chronic changes in female hormones. Patch clamp experiments and quantitative PCR were used to compare outward currents and transcript expression in colonic myocytes from male, non-pregnant, pregnant and ovariectomized mice. Groups of ovariectomized mice received injections of oestrogen or progesterone to investigate the effects of hormone replacement. The capacitance of colonic myocytes from non-pregnant females was larger than in males. Net outward current density in male and ovariectomized mice was higher than in non-pregnant females and oestrogen-treated ovariectomized mice. Current densities in late pregnancy were lower than in female controls. Progesterone had no effect on outward currents. A-type currents were decreased in non-pregnant females compared with ovariectomized mice, and were further decreased by pregnancy or oestrogen replacement. Kv4.3 transcripts did not differ significantly between groups; however, expression of the potassium channel interacting protein KChIP1 was elevated in ovariectomized mice compared with female controls and oestrogen-treated ovariectomized mice. Delayed rectifier currents were not affected by oestrogen. In the mouse colon, oestrogen suppresses A-type currents, which are important for regulating excitability. These observations suggest a possible link between female hormones and altered colonic motility associated with menses, pregnancy and menopause. [source] Biopsy-Diagnosed Renal Disease in Patients After Transplantation of Other Organs and TissuesAMERICAN JOURNAL OF TRANSPLANTATION, Issue 9 2010A. Schwarz Renal function deteriorates in about half of patients undergoing other transplants. We report the results of 105 renal biopsies from 101 nonrenal transplant recipients (bone marrow 14, liver 41, lung 30, heart 20). Biopsy indications were protracted acute renal failure (9%), creatinine increases (83%), heavy proteinuria (22%), or renal insufficiency before re-transplantation (9%). Histological findings other than nonspecific chronic changes, hypertension-related damage, and signs of chronic CNI toxicity included primary glomerular disease (17%), mostly after liver transplantation (21%) or after bone marrow transplantation (29%), and thrombotic microangiopathy (TMA) namely (10%). TMA had the most serious impact on the clinical course. Besides severe hypertension, one TMA patient died of cerebral hemorrhage, 5 had hemolytic-uremic syndrome, and 6 rapidly developed end-stage renal failure. TMA patients had the shortest kidney survival post-biopsy and, together with patients with acute tubular injury, the shortest kidney and patient survival since transplantation. Nine TMA patients had received CNI, 3 of them concomitantly received an mTOR-inhibitor. CNI toxicity is implicated in most patients with renal failure after transplant of other organs and may play a role in the development of TMA, the most serious complication. However, decreased renal function should not be routinely ascribed to CNI. [source] The obligatory role of the kidney in long-term arterial blood pressure control: extending Guyton's model of the circulationANAESTHESIA, Issue 11 2009K. L. Dorrington Summary We describe a model for the essential role of the kidney in long-term blood pressure regulation. We begin with a simple hydraulic model for the circulation, with a constant circulating volume. We show, with the help of a modification of Guyton's classic diagram, that cardiac output and mean arterial pressure are functions of circulating volume, peripheral resistance, venous and arterial compliances, and the cardiac Starling curve. This approach models only acute changes in a ,closed' circulation , one where there is no intake or excretion of fluid. The model is then adapted to ,open' the circulation, include a role for the kidney, and represent more chronic changes. Arterial pressure is then a sole function of renal behaviour and daily sodium (and liquid) intake, and becomes independent of other cardiovascular variables. As well as generating specific hypotheses for further investigation, these models can be used for the purpose of education in cardiovascular control and the treatment of hypertension. [source] Lowering of blood pressure during chronic suppression of central sympathetic outflow: Insight from computer simulationsCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 2 2010Radu Iliescu Summary 1. Chronic electrical stimulation of the carotid sinuses has provided unique insight into the mechanisms that cause sustained reductions in blood pressure during chronic suppression of central sympathetic outflow. 2. Because renal denervation does not abolish the sustained fall in arterial pressure in response to baroreflex activation, this observation has seemingly challenged the concept that the kidneys play a critical role in the long-term control of arterial pressure during chronic changes in sympathetic activity. The aim of the present study was to use computer simulations to provide a more comprehensive understanding of physiological mechanisms that mediate sustained reductions in arterial pressure during prolonged baroreflex-mediated suppression of central sympathetic outflow. 3. Physiological responses to baroreflex activation under different conditions were simulated by an established mathematical model of human physiology (QHP2008; see Supporting Information (Appendix S1) provided in the online version of this article and/or http://groups.google.com/group/modelingworkshop). The model closely reproduced empirical data, providing important validation of its accuracy. 4. The simulations indicated that baroreflex-mediated suppression of renal sympathetic nerve activity does chronically increase renal excretory function but that, in addition, hormonal and haemodynamic mechanisms also contribute to this natriuretic response. The contribution of these redundant natriuretic mechanisms to the chronic lowering of blood pressure is of increased importance when suppression of renal adrenergic activity is prevented, such as after renal denervation. Activation of these redundant natriuretic mechanisms occurs at the expense of excessive fluid retention. 5. More broadly, the present study illustrates the value of numerical simulations in elucidating physiological mechanisms that are not obvious intuitively and, in some cases, not readily testable in experimental studies. [source] | ||||||||||||||||||||||