45 resultados para pancreas islet
em Queensland University of Technology - ePrints Archive
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The 'histone code' is a well-established hypothesis describing the idea that specific patterns of post-translational modifications to histones act like a molecular "code" recognised and used by non-histone proteins to regulate specific chromatin functions. One modification which has received significant attention is that of histone acetylation. The enzymes which regulate this modification are described as histone acetyltransferases or HATs, and histone deacetylases or HDACs. Due to their conserved catalytic domain HDACs have been actively targeted as a therapeutic target. The proinflammatory environment is increasingly being recognised as a critical element for both degenerative diseases and cancer. The present review will discuss the current knowledge surrounding the clinical potential & current development of histone deacetylases for the treatment of diseases for which a proinflammatory environment plays important roles, and the molecular mechanisms by which such inhibitors may play important functions in modulating the proinflammatory environment. © 2009 Bentham Science Publishers Ltd.
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Diabetic neuropathy is associated with increased morbidity and mortality. To date, limited data in subjects with impaired glucose tolerance and diabetes demonstrate nerve fiber repair after intervention. This may reflect a lack of efficacy of the interventions but may also reflect difficulty of the tests currently deployed to adequately assess nerve fiber repair, particularly in short-term studies. Corneal confocal microscopy (CCM) represents a novel noninvasive means to quantify nerve fiber damage and repair. Fifteen type 1 diabetic patients undergoing simultaneous pancreas-kidney transplantation (SPK) underwent detailed assessment of neurologic deficits, quantitative sensory testing (QST), electrophysiology, skin biopsy, corneal sensitivity, and CCM at baseline and at 6 and 12 months after successful SPK. At baseline, diabetic patients had a significant neuropathy compared with control subjects. After successful SPK there was no significant change in neurologic impairment, neurophysiology, QST, corneal sensitivity, and intraepidermal nerve fiber density (IENFD). However, CCM demonstrated significant improvements in corneal nerve fiber density, branch density, and length at 12 months. Normalization of glycemia after SPK shows no significant improvement in neuropathy assessed by the neurologic deficits, QST, electrophysiology, and IENFD. However, CCM shows a significant improvement in nerve morphology, providing a novel noninvasive means to establish early nerve repair that is missed by currently advocated assessment techniques.
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The isolation of islets by collagenase digestion can cause damage and impact the efficiency of islet engraftment and function. In this study, we assessed the basement membranes (BMs) of mouse pancreatic islets as a molecular biomarker for islet integrity, damage after isolation, and islet repair in vitro as well as in the absence or presence of an immune response after transplantation. Immunofluorescence staining of BM matrix proteins and the endothelial cell marker platelet endothelial cell adhesion molecule-1 (PECAM-1) was performed on pancreatic islets in situ, isolated islets, islets cultured for 4 days, and islet grafts at 3-10 days posttransplantation. Flow cytometry was used to investigate the expression of BM matrix proteins in isolated islet β-cells. The islet BM, consisting of collagen type IV and components of Engelbreth-Holm-Swarm (EHS) tumor laminin 111, laminin α2, nidogen-2, and perlecan in pancreatic islets in situ, was completely lost during islet isolation. It was not reestablished during culture for 4 days. Peri- and intraislet BM restoration was identified after islet isotransplantation and coincided with the migration pattern of PECAM-1(+) vascular endothelial cells (VECs). After islet allotransplantation, the restoration of VEC-derived peri-islet BMs was initiated but did not lead to the formation of the intraislet vasculature. Instead, an abnormally enlarged peri-islet vasculature developed, coinciding with islet allograft rejection. The islet BM is a sensitive biomarker of islet damage resulting from enzymatic isolation and of islet repair after transplantation. After transplantation, remodeling of both peri- and intraislet BMs restores β-cell-matrix attachment, a recognized requirement for β-cell survival, for isografts but not for allografts. Preventing isolation-induced islet BM damage would be expected to preserve the intrinsic barrier function of islet BMs, thereby influencing both the effector mechanisms required for allograft rejection and the antirejection strategies needed for allograft survival.
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The impact of host immunity on outcome in nonsmall cell lung cancer (NSCLC) is controversial. We examined the relationship between lymphoid infiltration patterns in NSCLC and prognosis. Tumour- and stroma-infiltrating CD3+, CD8+ and forkhead box P3 (Foxp3)+ T-lymphocytes were identified using immunohistochemistry and a novel image analysis algorithm to assess total, cytotoxic and regulatory T-lymphocyte counts, respectively, in 196 NSCLC cases. The median cell count was selected as a cut-point to define patient subgroups and the ratio of the corresponding tumour islet:stroma (TI/S) counts was determined. There was a positive association between overall survival and increased CD8+ TI/S ratio (hazard ratio (HR) for death 0.44, p<0.001) but an inverse relationship between Foxp3+ TI/S ratio and overall survival (HR 4.86, p<0.001). Patients with high CD8+ islet (HR 0.48, p<0.001) and Foxp3+ stromal (HR 0.23, p<0.001) counts had better survival, whereas high CD3+ and CD8+ stromal counts and high Foxp3+ islet infiltration conferred a worse survival (HR 1.55, 2.19 and 3.14, respectively). By multivariate analysis, a high CD8+ TI/S ratio conferred an improved survival (HR 0.48, p=0.002) but a high Foxp3+ TI/S ratio was associated with worse survival (HR 3.91, p<0.001). Microlocalisation of infiltrating T-lymphocytes is a powerful predictor of outcome in resected NSCLC.
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Objectives: Ecological studies support the hypothesis that there is an association between vitamin D and pancreatic cancer (PaCa) mortality, but observational studies are somewhat conflicting. We sought to contribute further data to this issue by analyzing the differences in PaCa mortality across the eastern states of Australia and investigating if there is a role of vitamin D-effective ultraviolet radiation (DUVR), which is related to latitude. ---------- Methods: Mortality data from 1968 to 2005 were sourced from the Australian General Record of Incidence and Mortality books. Negative binomial models were fitted to calculate the association between state and PaCa mortality. Clear sky monthly DUVR in each capital city was also modeled. ---------- Results: Mortality from PaCa was 10% higher in southern states than in Queensland, with those in Victoria recording the highest mortality risk (relative risk, 1.13; 95% confidence interval, 1.09-1.17). We found a highly significant association between DUVR and PaCa mortality, with an estimated 1.5% decrease in the risk per 10-kJ/m2 increase in yearly DUVR. ---------- Conclusions: These data show an association between latitude, DUVR, and PaCa mortality. Although this study cannot be used to infer causality, it supports the need for further investigations of a possible role of vitamin D in PaCa etiology.
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OBJECTIVE: The accurate quantification of human diabetic neuropathy is important to define at-risk patients, anticipate deterioration, and assess new therapies. ---------- RESEARCH DESIGN AND METHODS: A total of 101 diabetic patients and 17 age-matched control subjects underwent neurological evaluation, neurophysiology tests, quantitative sensory testing, and evaluation of corneal sensation and corneal nerve morphology using corneal confocal microscopy (CCM). ---------- RESULTS: Corneal sensation decreased significantly (P = 0.0001) with increasing neuropathic severity and correlated with the neuropathy disability score (NDS) (r = 0.441, P < 0.0001). Corneal nerve fiber density (NFD) (P < 0.0001), nerve fiber length (NFL), (P < 0.0001), and nerve branch density (NBD) (P < 0.0001) decreased significantly with increasing neuropathic severity and correlated with NDS (NFD r = −0.475, P < 0.0001; NBD r = −0.511, P < 0.0001; and NFL r = −0.581, P < 0.0001). NBD and NFL demonstrated a significant and progressive reduction with worsening heat pain thresholds (P = 0.01). Receiver operating characteristic curve analysis for the diagnosis of neuropathy (NDS >3) defined an NFD of <27.8/mm2 with a sensitivity of 0.82 (95% CI 0.68–0.92) and specificity of 0.52 (0.40–0.64) and for detecting patients at risk of foot ulceration (NDS >6) defined a NFD cutoff of <20.8/mm2 with a sensitivity of 0.71 (0.42–0.92) and specificity of 0.64 (0.54–0.74). ---------- CONCLUSIONS: CCM is a noninvasive clinical technique that may be used to detect early nerve damage and stratify diabetic patients with increasing neuropathic severity. Established diabetic neuropathy leads to pain and foot ulceration. Detecting neuropathy early may allow intervention with treatments to slow or reverse this condition (1). Recent studies suggested that small unmyelinated C-fibers are damaged early in diabetic neuropathy (2–4) but can only be detected using invasive procedures such as sural nerve biopsy (4,5) or skin-punch biopsy (6–8). Our studies have shown that corneal confocal microscopy (CCM) can identify early small nerve fiber damage and accurately quantify the severity of diabetic neuropathy (9–11). We have also shown that CCM relates to intraepidermal nerve fiber loss (12) and a reduction in corneal sensitivity (13) and detects early nerve fiber regeneration after pancreas transplantation (14). Recently we have also shown that CCM detects nerve fiber damage in patients with Fabry disease (15) and idiopathic small fiber neuropathy (16) when results of electrophysiology tests and quantitative sensory testing (QST) are normal. In this study we assessed corneal sensitivity and corneal nerve morphology using CCM in diabetic patients stratified for the severity of diabetic neuropathy using neurological evaluation, electrophysiology tests, and QST. This enabled us to compare CCM and corneal esthesiometry with established tests of diabetic neuropathy and define their sensitivity and specificity to detect diabetic patients with early neuropathy and those at risk of foot ulceration.
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Cell based therapies as they apply to tissue engineering and regenerative medicine, require cells capable of self renewal and differentiation, and a prerequisite is to be able to prepare an effective dose of ex vivo expanded cells for autologous transplants. The in vivo identification of a source of physiologically relevant cell types suitable for cell therapies therefore figures as an integral part of tissue engineering. Stem cells serve as a reserve for biological repair, having the potential to differentiate into a number of specialised cell types within the body; they therefore represent the most useful candidates for cell based therapies. The primary goal of stem cell research is to produce cells that are both patient specific, as well as having properties suitable for the specific conditions for which they are intended to remedy. From a purely scientific perspective, stem cells allow scientists to gain a deeper understanding of developmental biology and regenerative therapies. Stem cells have acquired a number of uses for applications in regenerative medicine, immunotherapy, gene therapy, but it is in the area of tissue engineering that they generate most excitement, primarily as a result of their capacity for self-renewal and pluripotency. A unique feature of stem cells is their ability to maintain an uncommitted quiescent state in vivo and then, once triggered by conditions such as disease, injury or natural wear or tear, serve as a reservoir and natural support system to replenish lost cells. Although these cells retain the plasticity to differentiate into various tissues, being able to control this differentiation process is still one of the biggest challenges facing stem cell research. In an effort to harness the potential of these cells a number of studies have been conducted using both embryonic/foetal and adult stem cells. The use of embryonic stem cells (ESC) have been hampered by strong ethical and political concerns, this despite their perceived versatility due to their pluripotency. Ethical issues aside, other concerns raised with ESCs relates to the possibility of tumorigenesis, immune rejection and complications with immunosuppressive therapies, all of which adds layers of complications to the application ESC in research and which has led to the search for alternative sources for stem cells. The adult tissues in higher organisms harbours cells, termed adult stem cells, and these cells are reminiscent of unprogrammed stem cells. A number of sources of adult stem cells have been described. Bone marrow is by far the most accessible source of two potent populations of adult stem cells, namely haematopoietic stem cells (HSCs) and bone marrow mesenchymal stem cells (BMSCs). Autologously harvested adult stem cells can, in contrast to embryonic stem cells, readily be used in autografts, since immune rejection is not an issue; and their use in scientific research has not attracted the ethical concerns which have been the case with embryonic stem cells. The major limitation to their use, however, is the fact that adult stem cells are exceedingly rare in most tissues. This fact makes identifying and isolating these cells problematic; bone marrow being perhaps the only notable exception. Unlike the case of HSCs, there are as yet no rigorous criteria for characterizing MSCs. Changing acuity about the pluripotency of MSCs in recent studies has expanded their potential application; however, the underlying molecular pathways which impart the features distinctive to MSCs remain elusive. Furthermore, the sparse in vivo distribution of these cells imposes a clear limitation to their study in vitro. Also, when MSCs are cultured in vitro, there is a loss of the in vivo microenvironment, resulting in a progressive decline in proliferation potential and multipotentiality. This is further exacerbated with increased passage numbers in culture, characterized by the onset of senescence related changes. As a consequence, it is necessary to establish protocols for generating large numbers of MSCs but without affecting their differentiation potential. MSCs are capable of differentiating into mesenchymal tissue lineages, including bone, cartilage, fat, tendon, muscle, and marrow stroma. Recent findings indicate that adult bone marrow may also contain cells that can differentiate into the mature, nonhematopoietic cells of a number of tissues, including cells of the liver, kidney, lung, skin, gastrointestinal tract, and myocytes of heart and skeletal muscle. MSCs can readily be expanded in vitro and can be genetically modified by viral vectors and be induced to differentiate into specific cell lineages by changing the microenvironment–properties which makes these cells ideal vehicles for cellular gene therapy. MSCs can also exert profound immunosuppressive effects via modulation of both cellular and innate immune pathways, and this property allows them to overcome the issue of immune rejection. Despite the many attractive features associated with MSCs, there are still many hurdles to overcome before these cells are readily available for use in clinical applications. The main concern relates to in vivo characterization and identification of MSCs. The lack of a universal biomarker, sparse in vivo distribution, and a steady age related decline in their numbers, makes it an obvious need to decipher the reprogramming pathways and critical molecular players which govern the characteristics unique to MSCs. This book presents a comprehensive insight into the biology of adult stem cells and their utility in current regeneration therapies. The adult stem cell populations reviewed in this book include bone marrow derived MSCs, adipose derived stem cells (ASCs), umbilical cord blood stem cells, and placental stem cells. The features such as MSC circulation and trafficking, neuroprotective properties, and the nurturing roles and differentiation potential of multiple lineages have been discussed in details. In terms of therapeutic applications, the strengths of MSCs have been presented and their roles in disease treatments such as osteoarthritis, Huntington’s disease, periodontal regeneration, and pancreatic islet transplantation have been discussed. An analysis comparing osteoblast differentiation of umbilical cord blood stem cells and MSCs has been reviewed, as has a comparison of human placental stem cells and ASCs, in terms of isolation, identification and therapeutic applications of ASC in bone, cartilage regeneration, as well as myocardial regeneration. It is my sincere hope that this book will update the reader as to the research progress of MSC biology and potential use of these cells in clinical applications. It will be the best reward to all contributors of this book, if their efforts herein may in some way help the readers in any part of their study, research, and career development.
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Poem published in Islet
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Mesenchymal stem cells (MSCs) are undifferentiated, multi-potent stem cells with the ability to renew. They can differentiate into many types of terminal cells, such as osteoblasts, chondrocytes, adipocytes, myocytes, and neurons. These cells have been applied in tissue engineering as the main cell type to regenerate new tissues. However, a number of issues remain concerning the use of MSCs, such as cell surface markers, the determining factors responsible for their differentiation to terminal cells, and the mechanisms whereby growth factors stimulate MSCs. In this chapter, we will discuss how proteomic techniques have contributed to our current knowledge and how they can be used to address issues currently facing MSC research. The application of proteomics has led to the identification of a special pattern of cell surface protein expression of MSCs. The technique has also contributed to the study of a regulatory network of MSC differentiation to terminal differentiated cells, including osteocytes, chondrocytes, adipocytes, neurons, cardiomyocytes, hepatocytes, and pancreatic islet cells. It has also helped elucidate mechanisms for growth factor–stimulated differentiation of MSCs. Proteomics can, however, not reveal the accurate role of a special pathway and must therefore be combined with other approaches for this purpose. A new generation of proteomic techniques have recently been developed, which will enable a more comprehensive study of MSCs. Keywords
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14.1 Drugs for diabetes 14.1.1 Diabetes mellitus 14.1.2 Physiology of the pancreas 14.1.3 Insulin replacement therapy 14.1.4 Metformin 14.1.5 Acarbose 14.1.6 Sulfonylureas 14.1.7 Glitazones 14.1.8 Glucagon-like peptide-1, exenatide and sitagliptin 14.2 Drugs for obesity 14.2.1 Introduction 14.2.2 Amphetamine 14.2.3 Phentermine 14.2.5 Orlistat
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Objective To make a comprehensive estimation of the burden of malignant neoplasm in Shandong province by the means of disability- adjusted life year (DALY) for the first time. Methods DALYs were calculated following the procedures developed for the Global Burden of Disease (GBD) study to ensure comparability. We measured YLLs using the cancer mortality data of 19 Disease Surveillance Points (DSPs) in Shandong Province during 2000 and 2005. YLDs were estimated based on the cancer morbidity data of 6 Cancer Incidence Surveillance Points in Shandong Province in 2005. Results All cancers were responsible for 20.60 DALYs for every thousand population in Shandong Province (25.30 for men and 15.74 for women) . 94.3% of the losses were due to premature death and 5.7% to disability. 31.9% of the DALYs happened among 45~59 age group. The top 10 cancers for DALYs were lung cancer, liver cancer, stomach cancer, oesophagus cancer, colon/rectum cancer, breast cancer, leukemia, brain cancer, pancreas cancer and cervix uteri cancer in turn. The burden of major cancers such as lung cancer and liver cancer in Shandong were heavier than the global and national level. Conclusions he burden of disease of malignant neoplasm is mainly because of premature death. Lung cancer, liver cancer, stomach cancer and oesophagus cancer are the major cancers in Shandong Province and should be paid more attention to their prevention and control. Abstract in Chinese 目的 首次应用伤残调整寿命年(DALY)对山东省居民恶性肿瘤疾病负担进行综合评价. 方法 以2000-2005年山东省疾病监测系统的恶性肿瘤死亡资料和2005年山东省恶性肿瘤发病监测系统的发病资料为基础,利用世界卫生组织提供的专门公式,计算恶性肿瘤的YLLs、YLDs和DALYs,以此评价恶性肿瘤的疾病负担. 结果 山东省每千人每年因恶性肿瘤造成20.60个DALYs损失(男性25.30,女性15.74),其中,9413%为早死所致,5.7%因残疾所致:恶性肿瘤主要导致45~59岁人群的DALYs损失,占31.93%;恶性肿瘤疾病负担前10位依次为肺癌、肝癌、胃癌、食道癌、肠癌、乳腺癌、白血病、脑癌、胰腺癌和宫颈癌;山东省肺癌、肝癌等主要癌症疾病负担高于全球和全国水平. 结论 恶性肿瘤疾病负担主要由早死所致,肺癌、肝癌、胃癌和食道癌等主要癌症的防制地位十分突出.
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Objective To make a comprehensive estimation of the burden of malignant neoplasm on village residents in Linqu County by the means of DALY (Disability-adjusted life year). Methods DALYs, YLLs and YLDs were calculated following the procedures developed for the Global Burden of Disease (GBD) study to ensure comparability, based on the cancer registration data of Linqu villages during 1998-2004, in order to measure the burden of various caners. Results All cancers were responsible for 20.00 DALYs for every thousand population in Linqu County (24.82 for men and 14.96 for women). 92.5% of the losses were due to premature death and 7.5% to disability. 31.5% of the DALYs happened among 45-59 age group. The top 10 cancers for DALYs were stomach cancer, lung cancer, liver cancer, oesophagus cancer, leukemia,colon/rectum cancer, brain cancer, pancreas cancer, breast cancer and bone cancer in turn. Only stomach cancer, lung cancer and liver cancer together account for 69.3% of total DALYs due to malignant neoplasm. The burden of malignant neoplasm was on rising recent years. Conclusions The burden of disease of malignant neoplasm is mainly because of premature death. Stomach cancer, lung cancer and liver cancer lead to heavier burden than the global and national levels. Abstract in Chinese 目的 应用伤残调整寿命年(DALY)对临朐县农村恶性肿瘤疾病负担进行评价. 方法 以1998~2004年临朐县农村肿瘤登记资料为基础,利用全球疾病负担研究中使用的专门公式计算恶性肿瘤的YLLs、YLDs和DALYs,以此评价各类恶性肿瘤的疾病负担. 结果 临朐农村每千人每年因恶性肿瘤造成20.0个DALYs损失(男性24.82,女性14.96),其中92.5%为早死所致,7.5%因残疾所致;恶性肿瘤主要导致45~59岁人群的DALYs损失,占31.5%;恶性肿瘤疾病负担前10位依次为胃癌、肺癌、肝癌、食道癌、白血病、肠癌、脑癌、胰腺癌、乳腺癌和骨癌,其中仅胃癌、肺癌和肝癌三大肿瘤DALYs就占全部肿瘤的69.3%;临朐县农村恶性肿瘤疾病负担有进一步上升的趋势. 结论 恶性肿瘤疾病负担主要由早死所致,胃癌、肺癌、肝癌等主要癌症疾病负担高于全球和中国区水平.
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Purpose To investigate the trend of malignancies incidence and mortality in Linqu county, and to provide scientific evidence for the government to design and adjust polices on cancer prevention and control. [Methods] The cancer registration data of new cases from 1995 to 2004 and death cases from 1998 to 2004 were used to analyse the incidence and mortality and the trend in Linqu county. Results Cancer general incidence significantly increased from 1995 to 2004 (P<0.05). The increasing speed incidence in male was faster than that in female. The incidence of lung cancer, colon/rectum cancer and pancreas cancer increased significantly (P<0.05), especially of lung cancer with an acceleration incidence rate of 2.12/100,000 peryear in average. The general mortality increased gradually from 1998 to 2004 with no significance (P>0.05). Both incidence and mortality in population aged 80 or over increased significantly (P<0.05). Conclusion The cancer incidence is rising during recent 10 years , and the prevention and control for lung cancer are getting increasingly important. [目的] 了解临朐县恶性肿瘤发病与死亡趋势,为政府制订和调整防治对策提供科学依据. [方法] 利用临朐县1995~2004年恶性肿瘤发病登记资料和1998~2004年的死亡登记资料,计算各种癌症发病率和死亡率,并做趋势分析. [结果] 1995~2004年临朐县恶性肿瘤总发病率呈明显上升趋势(P<0.05),男性发病率上升速度高于女性.肺癌、肠癌、胰腺癌发病率上升显著(P<0.05),以肺癌最为迅速(年均升高2.12/10万).1998~2004年恶性肿瘤总死亡率略有上升,但无显著性(P>0.05);80岁及以上人群恶性肿瘤发病率与死亡率均呈上升趋势. [结论] 临朐县恶性肿瘤发病率近10年来呈现上升趋势,肺癌防治地位日益突出.