927 resultados para Bone metabolic disease
Resumo:
The use of granulocyte colony-stimulating factor (G-CSF)-mobilized peripheral blood as a source of stem cells has resulted in a high incidence of severe chronic graft-versus-host disease (cGVHD), which compromises the outcome of clinical allogeneic stem cell transplantation. We have studied the effect of G-CSF on both immune complex and fibrotic cGVHD directed to major (DBA/2 --> B6D2F1) or minor (B10.D2 --> BALB/c) histocompatibility antigens. In both models, donor pretreatment with G-CSF reduced cGVHD mortality in association with type 2 differentiation. However, after escalation of the donor T-cell dose, scleroderma occurred in 90% of the recipients of grafts from G-CSF-treated donors. In contrast, only 11% of the recipients of control grafts developed scleroderma, and the severity of hepatic cGVHD was also reduced. Mixing studies confirmed that in the presence of high donor T-cell doses, the severity of scleroderma was determined by the non-T-cell fraction of grafts from G-CSF-treated donors. These data confirm that the induction of cGVHD after donor treatment with G-CSF is dependent on the transfer of large numbers of donor T cells in conjunction with a putatively expanded myeloid lineage, providing a further rationale for the limitation of cell dose in allogeneic stem cell transplantation. (C) 2004 American Society for Blood and Marrow Transplantation.
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The relationship between reported treatments of lameness, metabolic disorders (milk fever, ketosis), digestive disorders, and technical efficiency (TE) was investigated using neutral and non-neutral stochastic frontier analysis (SFA). TE is estimated relative to the stochastic frontier production function for a sample of 574 Danish dairy herds collected in 1997. Contrary to most published results, but in line with the expected negative impact of disorders on the average cow milk production, herds reporting higher frequencies of milk fever are less technically efficient. Unexpectedly, however, the opposite results were observed for lameness, ketosis, and digestive disorders. The non-neutral stochastic frontier indicated that the opposite results are due to the relative. high productivities of inputs. The productivity of the cows is also reflected by the direction of impact of herd management variables. Whereas efficient farms replace cows more frequently, enroll heifers in production at an earlier age, and have shorter calving intervals, they also report higher frequency of disorder treatments. The average estimated energy corrected milk loss per cow is 1036, 451 and 242 kg for low, medium and high efficient farms. The study demonstrates the benefit of the stochastic frontier production function involving the estimation of individual technical efficiencies to evaluate farm performance and investigate the source of inefficiency. (C) 2004 Elsevier B.V. All rights reserved.
Resumo:
We have previously shown that complement factor 5a(C5a) plays a role in the pathogenesis of 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis in rats by using the selective, orally active C5a antagonist AcF-[OP(D-Cha) WR]. This study tested the efficacy and potency of a new C5a antagonist, hydrocinnamate (HC)-[OP(D-Cha) WR], which has limited intestinal lumenal metabolism, in this model of colitis. Analogs of AcF-[OP(D-Cha) WR] were examined for their susceptibility to alimentary metabolism in the rat using intestinal mucosal washings. One metabolically stable analog, HC-[OP(D-Cha)WR], was then evaluated pharmacokinetically and investigated at a range of doses (0.03 - 10 mg/kg/ day p.o.) in the 8-day rat TNBS- colitis model, against the comparator drug AcF-[OP(D-Cha) WR]. Using various amino acid substitutions, it was determined that the AcF moiety of AcF-[OP(D-Cha) WR] was responsible for the metabolic instability of the compound in intestinal mucosal washings. The analog HC-[OP( D-Cha) WR], equiactive in vitro to AcF-[OP(D-Cha) WR], was resistant to intestinal metabolism, but it displayed similar oral bioavailability to AcF-[OP(D-Cha) WR]. However, in the rat TNBS- colitis model, HC-[OP(D-Cha) WR] was effective at reducing mortality, colon edema, colon macroscopic scores, and increasing food consumption and body weights, at 10- to 30- fold lower oral doses than AcF-[OP( D-Cha) WR]. These studies suggest that resistance to intestinal metabolism by HC-[OP(D-Cha) WR] may result in increased local concentrations of the drug in the colon, thus affording efficacy with markedly lower oral doses than AcF-[OP(D-Cha) WR] against TNBS-colitis. This large increase in potency and high efficacy of this compound makes it a potential candidate for clinical development against intestinal diseases such as inflammatory bowel disease.
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The aims of this study were to establish the nutritional status of children pre- BMT and to determine whether predictive methods of assessing nutritional status and resting energy expenditure ( REE) are accurate in this population. We analysed the body cell mass ( BCM) ( n = 26) and REE ( n = 24) in children undergoing BMT. BCM was adjusted for height ( BCM/ HTp) and expressed as a Z score to represent nutritional status. To determine whether body mass index ( BMI) was indicative of nutritional status in children undergoing BMT, BMI Z scores were compared to the reference method of BCM/ HTp Z scores. Schofield predictive equations of basal metabolic rate ( BMR) were compared to measured REE to evaluate the accuracy of the predictive equations. The mean BCM/ HTp Z score for the subject population was -1.09 +/- 1.28. There was no significant relationship between BCM/ HTp Z score and BMI Z score ( r = 0.34; P > 0.05); however there was minimal difference between measured REE and predicted BMR ( bias = -11 +/- 149 kcal/ day). The results of this study demonstrate that children undergoing BMT may have suboptimal nutritional status and that BMI is not an accurate indication of nutritional status in this population. However, Schofield equations were found to be suitable for representing REE in children pre- BMT.
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The metabolic syndrome (MS) is associated with cardiovascular risk exceeding that expected from atherosclerotic risk factors, but the mechanism of this association is unclear. We sought to determine the effects of the MS on myocardial and vascular function and cardiorespiratory fitness in 393 subjects with significant risk factors but no cardiovascular disease and negative stress echocardiographic findings. Myocardial function was assessed by global strain rate, strain, and regional systolic velocity (s(m)) and diastolic velocity (e(m)) using tissue Doppler imaging. Arterial compliance was assessed using the pulse pressure method, involving simultaneous radial applanation tonometry and echocardiographic measurement of stroke volume. Exercise capacity was measured by expired gas analysis. Significant and incremental variations in left ventricular systolic (s(m), global strain, and strain rate) and diastolic (e(m)) function were found according to the number of components of MS (p <0.001). MS contributed to reduced systolic and diastolic function even in those without left ventricular hypertrophy (p <0.01). A similar dose-response association was present between the number of components of the MS and exercise capacity (p <0.001) and arterial compliance. The global strain rate and em were independent predictors of exercise capacity. In conclusion, subclinical left ventricular dysfunction corresponded to the degree of metabolic burden, and these myocardial changes were associated with reduced cardiorespiratory fitness.' Subjects with MS who also have subclinical myocardial abnormalities and reduced cardiorespiratory fitness may have a higher risk of cardiovascular disease events and heart failure. (C) 2005 Elsevier Inc. All rights reserved.
Resumo:
Bone mineral density (BMD) may be associated with hearing loss in older adults. Demineralization of the cochlear capsule has been associated with hearing loss in those with Paget's disease of the bone and otosclerosis. Osteoporosis may also result in cochlear capsule demineralization. We hypothesized that lower hip BMD and lower heel ultrasound measurements would be associated with hearing loss in a population-based sample of 2,089 older black and white men and women. Bone parameters and hearing function were measured at the fourth clinical follow-up visit. Audiometric threshold testing was used to measure air- and bone-conduction hearing sensitivity. BMD of the hip and its subregions was measured using dual-energy X-ray absorptiometry. Calcaneal bone measurements [broadband ultrasound attenuation (BUA), speed of sound (SOS) and the quantitative ultrasound index (QUI)] were obtained using heel ultrasound. After adjusting for known hearing loss risk factors, no association was found between hearing and any of the bone measurements in whites and black women. In black men, however, lower hip BMD was associated with higher odds of hearing loss; for each standard deviation decrease in total hip BMD, the odds of hearing loss were 1.41 (95% confidence interval 1.08, 1.83), 1.39 (95% CI 1.07, 1.82) for femoral neck BMD and 1.65 (95% CI 1.26, 2.16) for trochanter BMD. Conductive hearing loss was associated with lower heel ultrasound measurements, though only among white men. The results of this study are mixed and inconclusive. Lower BMD of the hip and its subregions was associated with hearing loss among black men, but not among whites or black women. Lower measurements on heel ultrasound were associated with conductive hearing loss, though only among white men. These results suggest that axial and appendicular bone parameters may be modestly associated with hearing loss in older men, but not in women.
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Metabolism, in part, is regulated by the peroxisome proliferator-activated receptors (PPARs). The PPARs act as nutritional lipid sensors and three mammalian PPAR subtypes designated PPARalpha (NR1C1), PPARgamma (NR1C3) and PPARdelta (NR1C2) have been identified. This subgroup of nuclear hormone receptors binds DNA and controls gene expression at the nexus of pathways that regulate lipid and glucose homeostasis, energy storage and expenditure in an organ-specific manner. Recent evidence has demonstrated activation of PPARdelta in the major mass peripheral tissue (ie, adipose and skeletal muscle). It enhances glucose tolerance, insulin-stimulated glucose disposal, lipid catabolism, energy expenditure, cholesterol efflux and oxygen consumption. These effects positively influence the blood-lipid profile. Furthermore, PPARdelta activation produces a predominant type I/slow twitch/oxidative muscle fiber phenotype that leads to increased endurance, insulin sensitivity and resistance to obesity. PPARdelta has rapidly emerged as a potential target in the battle against dyslipidemia, insulin insensitivity, type II diabetes and obesity, with therapeutic efficacy in the treatment of cardiovascular disease risk factors. GW-501516 is currently undergoing phase II safety and efficacy trials in human volunteers for the treatment of dyslipidemia. The outcome of these clinical trials are eagerly awaited against a background of conflicting reports about cancer risks in genetically predisposed animal models. This review focuses on the potential pharmacological utility of selective PPARdelta agonists in the context of risk factors associated with metabolic and cardiovascular disease.
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Rates of kidney disease among several indigenous groups have been shown to be substantially higher than corresponding non-indigenous groups. This excess has been clearly shown among Aboriginal Australians with respect to both end-stage kidney disease and early kidney disease. Rates of cardiovascular disease among Aboriginal Australians are also very high, as are rates of diabetes, smoking, and possibly overweight and obesity. These factors have been traditionally linked with cardiovascular and renal disease as part of a broader metabolic syndrome. However, the links and interfaces between cardiovascular and kidney disease in this environment extend beyond these traditional factors. The factors associated with atherosclerosis have expanded in recent years to include markers of inflammation, some infection, antioxidants, and other non-traditional risk factors. Given the high rates of acute infection and poor living conditions endured by many indigenous people, one might expect these non-traditional risk factors to be highly prevalent. In this review, we explore the relationships between markers of inflammation, some serological markers of infection, and other selected markers and both cardiovascular and renal disease. In doing so, we demonstrate links between kidney and cardiovascular disease at a number of levels, beyond the traditional cardiovascular/renal risk factors. Many of these factors are beyond the control of the individual or even community; addressing these issues a broader focus and biopsychosocial model. (C) 2005 by the National Kidney Foundation, Inc.
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Epidemiological evidence and in vitro data suggest that COX-2 is a key regulator of accelerated remodeling. Accelerated states of osteoblast and osteoclast activity are regulated by prostaglandins in vitro, but experimental evidence for specific roles of cyclooxygenase-2 (COX-2) and secretory phospholipase A(2) (sPLA(2)) in activated states of remodeling in vivo is lacking. The aim of this study was to determine the effect of specific inhibitors of sPLA(2)-IIa and COX-2 on bone remodeling activated by estrogen deficiency in adult female rats. One hundred and twenty-four adult female Wistar rats were ovariectomized (OVX) or sham-operated. Rats commenced treatment 14 days after surgery with either vehicle, a COX-2 inhibitor (DFU at 0.02 mg/kg/day and 2.0 mg/kg/day) or a sPLA(2)-group-IIa inhibitor (KH064 at 0.4 mg/kg/day and 4.0 mg/kg/day). Treatment continued daily until rats were sacrificed at 70 days or 98 days post-OVX. The right tibiae were harvested, fixed and embedded in methylmethacrylate for structural histomorphometric bone analysis at the proximal tibial metaphysis. The specific COX-2 or sPLA(2) inhibitors prevented ovariectomy-induced (OVX-induced) decreases in trabecular connectivity (P < 0.05); suppressed the acceleration of bone resorption; and maintained bone turnover at SHAM levels following OVX in the rat. The sPLA2 inhibitor significantly suppressed increases in osteoclast surface induced by OVX (P < 0.05), while the effect of COX-2 inhibition was less marked. These findings demonstrate that inhibitors of COX-2 and sPLA(2)-IIa can effectively suppress OVX-induced bone loss in the adult rat by conserving trabecular bone mass and architecture through reduced bone remodeling and decreased resorptive activity. Moreover, we report an important role of sPLA(2)-IIa in osteoclastogenesis that may be independent of the COX-2 metabolic pathway in the OVX rat in vivo. (c) 2006 Elsevier Inc. All rights reserved.
Resumo:
Background: Plasma cholinesterase activity is known to be correlated with plasma triglycerides, HDL- and LDL-cholesterol, and other features of the metabolic syndrome. A role in triglyceride metabolism has been proposed. Genetic variants that decrease activity have been studied extensively, but the factors contributing to overall variation in the population are poorly understood. We studied plasma cholinesterase activity in a sample of 2200 adult twins to assess covariation with cardiovascular risk factors and components of the metabolic syndrome, to determine the degree of genetic effects on enzyme activity, and to search for quantitative trait loci affecting activity. Methods and Results: Cholinesterase activity was lower in women than in men before the age of 50, but increased to activity values similar to those in males after that age. There were highly significant correlations with variables associated with the metabolic syndrome: plasma triglyceride, HDL- and LDL-cholesterol, apolipoprotein B and E, urate, and insulin concentrations; gamma-glutamyltransferase and aspartate and alanine aminotransferase activities; body mass index; and blood pressure. The heritability of plasma cholinesterase activity was 65%. Linkage analysis with data from the dizygotic twin pairs showed suggestive linkage on chromosome 3 at the location of the cholinesterase WHO gene and also on chromosome 5. Conclusions: Our results confirm and extend the connection between cholinesterase, cardiovascular risk factors, and metabolic syndrome. They establish a substantial heritability for plasma cholinesterase activity that might be attributable to variation near the structural gene and at an independent locus. (c) 2006 American Association for Clinical Chemistry.
Resumo:
Metabolic syndrome is associated with increased risk of coronary heart disease and type 2 diabetes, and appears to be widely prevalent in both developed and developing countries. While lifestyle modification is recommended for management of the syndrome, the dietary pattern most beneficial for patients is yet to be ascertained. Original research papers from the Medline database were examined for dietary patterns that may be associated with the syndrome. Three large-scale epidemiological studies were found fitting our criteria. Dietary patterns high in fruit and vegetable content were generally found to be associated with lower prevalence of metabolic syndrome. Diet patterns with high meat intake were frequently associated with components of metabolic syndrome, particularly impaired glucose tolerance. High dairy intake was generally associated with reduced risk for components of metabolic syndrome with some inconsistency in the literature regarding risk of obesity. Minimally processed cereals appeared to be associated with decreased risk of metabolic syndrome, while highly processed cereals with high glycaemic index are associated with higher risk. Fried foods were noticeably absent from any dietary pattern associated with decreased prevalence of metabolic syndrome. The conclusion of this review is that no individual dietary component could be considered wholly responsible for the association of diet with metabolic syndrome. Rather it is the overall quality of the diet that appears to offer protection against lifestyle disease such as metabolic syndrome. Further research is required into conditions, such as overweight and obesity, which may influence the effect of diet on the development of metabolic syndrome.
Resumo:
Host antigen-presenting cells (APCs) are known to be critical for the induction of graft-versus-host disease (GVHD) after allogeneic bone marrow transplantation (BMT), but the relative contribution of specific APC subsets remains unclear. We have studied the role of host B cells in GVHD by using B-cell-deficient mu MT mice as BMT recipients in a model of CD4-dependent GVHD to major histocompatlibility complex antigens. We demonstrate that acute GVHD is initially augmented in mu MT recipients relative to wild-type recipients (mortality: 85% vs 44%, P < .01), and this is the result of an increase in donor T-cell proliferation, expansion, and inflammatory cytokine production early after BMT. Recipient B cells were depleted 28-fold at the time of BMT by total body irradiation (TBI) administered 24 hours earlier, and we demonstrate that TBI rapidly induces sustained interleukin-110 (IL-10) generation from B cells but not dendritic cells (DCs) or other cellular populations within the spleen. Finally, recipient mice in which B cells are unable to produce IL-10 due to homologous gene deletion develop more severe acute GVHD than recipient mice in which B cells are wild type. Thus, the induction of IL-10 in host B cells during conditioning attenuates experimental acute GVHD.
Resumo:
Purpose To evaluate the imaging characteristics of a cohort of patients with ocular adnexal lymphoproliferative disease (OALD). Methods A noncomparative retrospective review between 1992 and 1995 and prospective study from 1995 to 2005 of the clinical, imaging and treatment of 105 patients presenting to tertiary orbital referral centre presenting with OALD. Results One hundred and five patients (mean age 61 years, range 11-90 years) with equal gender distribution were included. Fifty-three were primary and 52 were secondary. Computed tomography (CT) usually showed a well-circumscribed lesion of greater than brain density, moulding to adjacent tissues with moderate enhancement. Aggressive histology was associated with bone destruction, while moulding was associated with indolent histology (P < 0.005). MRI in OALD showed intermediate signal intensity on T1- and T2-weighted images and moderate enhancement with gadolinium. Gallium scanning sensitivity to detect ocular adnexal disease was 25 and 57% for systemic involvement. Positron emission tomography (PET) upstaged (71%) of patients with systemic lymphoproliferative involvement, having a higher sensitivity than CT in detecting distant disease (86 vs 72%). Conclusions CT and/ or MRI are essential in the evaluation of OALD and can be used to establish that an orbital lesion may be lymphoprolifetaive in nature. Further, these imaging modalities may predict the behaviour of the lymphoma in certain cases. Gallium scanning provides no additional information to CT and does not influence patient treatment. PET represents an important addition to the assessment of OALD with real impact on patient management.
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Musculoskeletal diseases are one of the major causes of disability around the world and have been a significant reason for the development of the Bone and Joint Decade. Rheumatoid arthritis, osteoarthritis and back pain are important causes of disability-adjusted-life years in both the developed and developing world. COPCORD studies in over 17 countries around the world have identified back and knee pain as common in the community and are likely to increase with the ageing population. Musculoskeletal conditions are an enormous cost to the community in economic terms, and these figures emphasise how governments need to invest in the future and look at ways of reducing the burden of musculoskeletal diseases by encouraging exercise and obesity prevention campaigns.