Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011854 (type 1 diabetes)
 20,749 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Recent studies in adult patients with type 1 diabetes mellitus (T1DM) and T2DM have examined the potential utility, benefits, and side effects of agents that augment insulin secretion after oral ingestion of nutrients in comparison with intravenous nutrient delivery, the so-called incretins. Two families of incretin-like substances are now approved for use in adults. Glucagon-like peptide-1 (GLP-1) or agents that bind to its receptor (exenatide, Byetta) or agents that inhibit its destruction [dipeptidyl peptidase-IV (DPP-IV) inhibitors, Vildagliptin] improve insulin secretion, delay gastric emptying, and suppress glucagon secretion while decreasing food intake without increasing hypoglycemia. Pramlintide, a synthetic amylin analog, also decreases glucagon secretion and delays gastric emptying, improves hemoglobin A1c (HbA1C), and facilitates weight reduction without causing hypoglycemia. We review the historical discovery of these agents, their physiology [corrected] and their current applications. Remarkably, only one or two studies have been reported in children. Pediatricians caring for children with T1DM and T2DM should become familiar with these agents and investigate their applicability, as they seem likely to enhance our therapeutic armamentarium to treat children with diabetes mellitus.
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PMID:Newer therapeutic options for children with diabetes mellitus: theoretical and practical considerations. 1662 19

Pramlintide is the first new antihyperglycemic agent approved for both type 2 and type 1 diabetes since insulin was developed in the 1920s. It is a synthetic analogue of human amylin, a naturally occurring neuroendocrine hormone synthesized by pancreatic beta cells. Pramlintide helps regulate the rate of glucose appearance and improves glucose control postprandially. This action is accomplished through suppressing inappropriate postprandial glucagon secretion and regulating gastric emptying, and is associated with a feeling of satiety. It is given at mealtimes and is indicated for use in type 2 and type 1 diabetes as an adjunct treatment in patients who use mealtime insulin therapy and who have failed to achieve desired glucose control despite optimal insulin therapy. Pramlintide therapy should only be considered for patients who are receiving ongoing care under the guidance of a health care professional skilled in the use of insulin and supported by services of diabetes educators. Pramlintide is used with insulin and has been associated with an increased risk of insulin-induced severe hypoglycemia, particularly in type 1 diabetes. Appropriate patient selection, careful patient instruction, and insulin dose adjustments help reduce this risk. In type 2 diabetes, pramlintide is initiated at 60 microg and may be increased to 120 microg two to three times daily with meals. In type 1 diabetes, pramlintide is initiated at 15 microg and may be increased to 30 or 60 microg with meals. Mealtime insulin should be reduced by 50% at pramlintide initiation and adjusted as the pramlintide dose is increased. It should be given subcutaneously with an insulin syringe and should not be mixed with insulin. The most commonly reported side effect is mild to moderate nausea with initiation, which is usually transient and short term in nature. Frequent self-monitoring of blood glucose is important during initiation to assist in insulin adjustments. Insulin type, dose, and timing as well as basal/bolus balance may require adjustment during pramlintide initiation. Despite requiring additional injections, patients report satisfaction with pramlintide therapy.
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PMID:Use of pramlintide: the patient's perspective. 1675 52

Amylin is a pancreatic beta-cell hormone that is cosecreted with insulin and plays an important physiologic role in glucose homeostasis. Pramlintide is an analogue of amylin recently approved by the Food and Drug Administration and represents the first new treatment for people with type 1 diabetes since the discovery of insulin more than 80 years ago. Pramlintide has been shown to reduce the day-to-day fluctuations in glucose values that are commonly seen despite maximized insulin therapy alone. Additional proven clinical benefits include flattening of the postprandial glucose values, reducing the A1C, and concomitant weight loss. This combination of benefits makes pramlintide an important therapeutic tool for improving the metabolic control and quality of life of people with type 1 diabetes.
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PMID:Amylin replacement therapy in patients with type 1 diabetes. 1675 53

Osteoporosis is a systemic skeletal disorder that remains a major public health problem due to significant fracture-associated morbidity and mortality. Because it has been shown that individuals having type I diabetes mellitus also suffer from osteopenia or osteoporosis, there is probably a pathophysiological mechanism that links pancreatic beta cell insufficiency with inappropriate bone formation. Many factors have been suggested, including amylin, a product of pancreatic beta cells with structural and functional similarity to calcitonin. Amylin has been shown to stimulate bone development via action on osteoblasts and osteoclasts. Recently, amylin receptors have been identified as complexed calcitonin receptor with receptor activity modifying proteins. Moreover, a synthetic amylin analogue (pramlintide) has been developed for clinical use. These findings including results from in vitro animal and human studies suggest a role for amylin as a potential diagnostic and therapeutical tool in patients with various bone diseases including osteoporosis. However, other structurally and functionally related hormones that affect bone metabolism should also be taken in account including calcitonin, calcitonin gene-related peptide and adrenomedullin.
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PMID:The role of amylin and related peptides in osteoporosis. 1679 21

Cytotoxic T-lymphocytes (CTLs) are considered to be essential for beta-cell destruction in type 1 diabetes. However, few islet-associated peptides have been demonstrated to activate autoreactive CTLs from type 1 diabetic subjects. In an effort to identify novel epitopes, we used matrix-assisted algorithms to predict peptides of glial fibrillary acidic protein (GFAP), prepro-islet amyloid polypeptide (ppIAPP), and islet-specific glucose-6-phosphatase catalytic subunit-related protein (IGRP) that likely bind to HLA-A*0201 with a strong affinity and contain a COOH-terminal proteasomal cleavage site. Seven peptides stabilized HLA-A*0201 expression in binding assays and were used to stimulate peripheral blood mononuclear cells and were evaluated for granzyme B secretion. We found that 5 of 13 type 1 diabetic subjects and 4 of 6 antibody-positive relatives exhibited greater numbers of granzyme B-secreting cells in response to at least one putative epitope compared with healthy control subjects. The most prevalent responses in antibody-positive and type 1 diabetic subjects were to ppIAPP(9-17). Other peptides recognized by type 1 diabetic or antibody-positive subjects included GFAP(143-151), IGRP(152-160), and GFAP(214-222). These data implicate peptides of ppIAPP, GFAP, and IGRP as CTL epitopes for a heterogenous CD8(+) T-cell response in type 1 subjects and antibody-positive relatives.
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PMID:Identification of Novel HLA-A*0201-restricted epitopes in recent-onset type 1 diabetic subjects and antibody-positive relatives. 1706 43

Type 1 diabetes results from the autoimmune destruction of insulin-producing pancreatic beta-cells by cytotoxic T-lymphocytes (CTLs). In humans, few beta-cell epitopes have been reported, thereby limiting the study of beta-cell-specific CTLs in type 1 diabetes. To identify additional epitopes, HLA class I peptide affinity algorithms were used to identify a panel of peptides derived from the beta-cell proteins islet amyloid polypeptide (IAPP), islet-specific glucose-6-phosphatase catalytic subunit-related protein (IGRP), insulin, insulinoma-associated antigen 2 (IA-2), and phogrin that were predicted to bind HLA-A*0201. Peripheral blood mononuclear cells from 24 HLA-A*0201 recent-onset type 1 diabetic patients and 11 nondiabetic control subjects were evaluated for gamma-interferon secretion in response to peptide stimulation in enzyme-linked immunospot assays. We identified peptides IAPP9-17, IGRP215-223, IGRP152-160, islet IA-2(172-180), and IA-2(482-490) as novel HLA-A*0201-restricted T-cell epitopes in type 1 diabetic patients. Interestingly, we observed a strong inverse correlation between the binding affinity of beta-cell peptides to HLA-A*0201 and CTL responses against those peptides in recent-onset type 1 diabetic patients. In addition, we found that self-reactive CTLs with specificity for an insulin peptide are frequently present in healthy individuals. These data suggest that many beta-cell epitopes are recognized by CTLs in recent-onset type 1 diabetic patients. These epitopes may be important in the pathogenesis of type 1 diabetes.
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PMID:Recognition of HLA class I-restricted beta-cell epitopes in type 1 diabetes. 1706 44

The capacity for self-renewal and differentiation of human embryonic stem (ES) cells makes them a potential source for generation of pancreatic beta cells for treating type I diabetes mellitus. Here, we report a newly developed and effective method, carried out in a serum-free system, which induced human ES cells to differentiate into insulin-producing cells. Activin A was used in the initial stage to induce definitive endoderm differentiation from human ES cells, as detected by the expression of the definitive endoderm markers Sox17 and Brachyury. Further, all-trans retinoic acid (RA) was used to promote pancreatic differentiation, as indicated by the expression of the early pancreatic transcription factors pdx1 and hlxb9. After maturation in DMEM/F12 serum-free medium with bFGF and nicotinamide, the differentiated cells expressed islet specific markers such as C-peptide, insulin, glucagon and glut2. The percentage of C-peptide-positive cells exceeded 15%. The secretion of insulin and C-peptide by these cells corresponded to the variations in glucose levels. When transplanted into renal capsules of Streptozotocin (STZ)-treated nude mice, these differentiated human ES cells survived and maintained the expression of beta cell marker genes, including C-peptide, pdx1, glucokinase, nkx6.1, IAPP, pax6 and Tcf1. Thirty percent of the transplanted nude mice exhibited apparent restoration of stable euglycemia; and the corrected phenotype was sustained for more than six weeks. Our new method provides a promising in vitro differentiation model for studying the mechanisms of human pancreas development and illustrates the potential of using human ES cells for the treatment of type I diabetes mellitus.
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PMID:In vitro derivation of functional insulin-producing cells from human embryonic stem cells. 1742 93

Complement can damage host tissue when overactivated. Evidence of complement self damage exists for Alzheimer disease (AD), age-related macular degeneration, type 1 diabetes mellitus (T1DM), and Parkinson disease (PD). Known complement activators include Abeta, found in AD, and IgG found in T1DM. We compared their complement activating ability in vitro with those of islet amyloid polypeptide (IAPP), which aggregates in the pancreas of T2DM, and alpha-synuclein (alpha-Syn), which aggregates in PD. We found that IAPP and the alternatively spliced alpha-Syn 112 form, but not full-length alpha-Syn 140, activated complement in vitro. Complement activation may contribute to death of insulin-secreting cells in T2DM or to neuronal death in Parkinson disease (PD) and related synucleinopathies where alpha-Syn 112 occurs. This suggests the possibility of anti-inflammatory treatment in these pathologies. It also suggests that blockers of complement activation may be an appropriate therapeutic target for a range of age-related degenerative diseases.
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PMID:Complement activation by islet amyloid polypeptide (IAPP) and alpha-synuclein 112. 1745 37

Demographic trends with longer life expectancy and a lifestyle characterized by low physical activity and high-energy food intake contribute to an increasing incidence of diabetes mellitus and osteoporosis. Diabetes mellitus is a risk factor for osteoporotic fractures. Patients with recent onset of type 1 diabetes mellitus may have impaired bone formation because of the absence of the anabolic effects of insulin and amylin, whereas in long-standing type 1 diabetes mellitus, vascular complications may account for low bone mass and increased fracture risk. Patients with type 2 diabetes mellitus display an increased fracture risk despite a higher BMD, which is mainly attributable to the increased risk of falling. Strategies to improve BMD and to prevent osteoporotic fractures in patients with type 1 diabetes mellitus may include optimal glycemic control and aggressive prevention and treatment of vascular complications. Patients with type 2 diabetes mellitus may additionally benefit from early visual assessment, regular exercise to improve muscle strength and balance, and specific measures for preventing falls.
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PMID:Osteoporosis in patients with diabetes mellitus. 1750 67

AC137 (pramlintide) is a 37-residue peptide analogue of the hormone amylin. Pramlintide has been studied as an adjunct antihyperglycemic treatment for patients with type 2 or type 1 diabetes who use insulin. This study took an empirical phase diagram (EPD) approach to obtain information about the structural stability of this peptide by compiling thermal perturbation data acquired from multiple spectroscopic methods, including high-resolution second-derivative UV absorbance spectroscopy, optical density, fluorescence, and circular dichroism. This approach enabled us to accomplish two major goals: (1) characterize the structure and physical stability of AC137 and (2) assess the application of EPDs to a small peptide. Results obtained at low concentration of AC137 revealed a peptide with ill-defined structure and insensitivity to pH. Use of isotope exchange NMR confirmed this lack of structure. At the current formulation of pH 4, AC137 exhibited stability at concentrations of 1.8 to 8.8 mg/mL. High concentrations of the peptide showed a tendency to aggregate at pH 6-7.5. Construction of EPDs under the various experimental conditions examined manifested color changes that correlated well with the raw data. The utility and limitations of the EPD approach when applied to weakly structured peptides are discussed.
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PMID:A biophysical characterization of the peptide drug pramlintide (AC137) using empirical phase diagrams. 1787 73


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