[Erythema nodosum].
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Biomedical subjects
Publications and source records attributed to B Gallwitz.
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AIMS/HYPOTHESIS: Diabetic dyslipidaemia contributes to the excess morbidity and mortality in patients with type 2 diabetes. Exogenous glucagon-like peptide 1 (GLP-1) lowers postprandial glycaemia predominantly by slowing gastric emptying. Therefore, the effects of GLP-1 on postprandial lipid levels and gastric emptying were assessed. METHODS: 14 healthy male volunteers were studied with an i.v. infusion of GLP-1 (1.2 pmol kg(-1) min(-1)) or placebo over 390 min in the fasting state. A solid test meal was served and gastric emptying was determined using a (13)C-labelled sodium octanoate breath test. Venous blood was drawn frequently for measurement of glucose, insulin, C-peptide, glucagon, GLP-1, triglycerides and NEFA. RESULTS: GLP-1 administration lowered fasting and postprandial glycaemia (p<0.0001). Gastric emptying was delayed by GLP-1 compared with placebo (p<0.0001). During GLP-1 administration, insulin secretory responses were higher in the fasting state but lower after meal ingestion. After meal ingestion, triglyceride plasma levels increased by 0.33+/-0.14 mmol/l in the placebo experiments (p<0.0001). In contrast, the postprandial increase in triglyceride levels was completely abolished by GLP-1 (change in triglycerides, -0.023+/-0.045 mmol/l; p<0.05). During GLP-1 infusion, plasma concentrations of NEFA were suppressed by 39% in the fasting state (p<0.01) and by 31+/-5% after meal ingestion (p<0.01). CONCLUSIONS/INTERPRETATION: GLP-1 improves postprandial lipidaemia, presumably as a result of delayed gastric emptying and insulin-mediated inhibition of lipolysis. Thus, by lowering both glucose and lipid concentrations, GLP-1 administration may reduce the cardiovascular risk in patients with type 2 diabetes.
Castleman disease, or angiofollicular lymph node hyperplasia, is a rare benign lymphoproliferative disorder. We report an uncommon case of retroperitoneal Castleman syndrome associated with adrenal hyperandrogenism and with interleukin-6 as the possible link in the pathophysiology of both disturbances. Four years after surgical resection of the paraadrenal mass, the patient is free of signs of recurrence of Castleman disease and adrenal hyperandrogenism.
Chronic renal failure is associated with an impairment of the GH/IGF-I axis. We report the diagnostic challenges in a 72-yr-old female suffering from end-stage renal disease and presenting with clinical findings suggestive of acromegaly. GH was not suppressed during an oral glucose tolerance test, but rose paradoxically. However, serum IGF-I levels were within the normal range. IGF-binding proteins (IGFBP)-2 and -3 were markedly elevated and GH-binding protein (GHBP) was diminished. Clinical findings suspicious of acromegaly could be ascribed to pre-existing characteristics and consequences of end-stage renal disease. This suggested that the disturbances of the GH/IGF-I axis in our patient were due to chronic renal disease, rather than acromegaly. In the work-up for acromegaly, clinicians should be alerted to GH resistance in chronic renal failure.
Endocrinology and diabetology are disciplines with an interdisciplinary approach. Patients with diabetes or endocrine disorders are diagnosed and treated by multiple disciplines both in an outpatient or in-hospital setting. Additional diabetes-specific professions also participate in the care of diabetic patients. The development of clinical pathways and case-management in institutionalized "Diabetes Centers" and "Endocrinology Centers" as platforms of cooperation is one way to improve patient care and to pool resources. In such centers an interdisciplinary decision support within the diagnostic and therapeutic process is important. E. g., interdisciplinary case conferences expediate and intensify the necessary flow of information. This guarantees the implementation of a rational and concerted treatment according to guidelines and finally optimize the clinical pathways in a continuous process improvement.
In industrial nations, over the last five decades conditions concerning nutrition and physical exercise as well as socio-economic circumstances have changed radically. One of the consequences following from this development has been a rapid increase in the prevalence of obesity. Studies have shown that currently 20 percent of the German adult population suffer from obesity. Investigations into the etiology of obesity have to address complex interactions between genetic, socio-economic and psychosocial factors. A year ago, at the University Hospital Tübingen different departments joined to set up the "Plattform Adipositas". Endocrinologists, obesity surgeons, professionals in sports medicine and psychosomatic medicine as well as dieticians are collaborating to develop scientifically based therapy programs and treatment pathways for obese patients. The following article gives an account of this exemplary interdisciplinary cooperation.
Congenital adrenal hyperplasia results from 21-hydroxylase deficiency in more than ninety percent of cases. The classical form of 21-hydroxylase deficiency presents in the neonatal period with virilization or adrenal insufficiency, with or without concurrent salt wasting. We report on a rare case of classic 21-hydroxylase deficiency diagnosed in late adulthood. A 39-year-old male patient presented for workup of infertility. Urologic investigation revealed small testes, bilateral testicular masses, and asthenozoospermia. The patient's steroid metabolism showed markedly increased levels of adrenal androgens, in particular of 17-hydroxyprogesterone amd 21-deoxycortisol. The gas chromatographic-mass spectrometric (GC-MS) urinary steroid profile was dominated by metabolites of 17-hydroxyprogesterone, while the endogenous glucocorticoid production was subnormally low. ACTH levels in plasma were elevated. These hormonal findings were consistent with 21-hydroxylase deficiency. Therapy with dexamethasone was initiated. The CTP21A2 gene analysis revealed the mutation I172N (ATC --> AAC) in exon 4 of allele 1 and a large gene deletion in allele 2. Cases of 21-hydroxylase deficiency diagnosed in late adulthood are rare; however, clinicians should be alert of this possibility.
The therapeutic options for treating type 2 diabetes have been widened by the introduction of exenatide as the first incretin mimetic. Incretins are gut hormones that contribute to the stimulation of insulin secretion after a carbohydrate rich meal. The incretin hormone glucagon-like peptide-1 (GLP-1) not only stimulates insulin secretion under hyperglycaemic conditions, but also suppresses glucagon secretion, slows gastric emptying, induces satiety and improves beta cell function in type 2 diabetes. These beneficial effects have awakened the interest to use GLP-1 for the treatment of type 2 diabetes. Because of its short biological half-life, GLP-1 itself is not practical for type 2 diabetes therapy. Exenatide is a peptide found in the lizard Heloderma suspectum and has a high similarity to GLP-1. Exenatide belongs to the novel class of incretin mimetics because of its incretin-like action. It has a much longer biological half life than GLP-1 and is a GLP-1 receptor agonist that can be used for therapeutic purposes by twice daily injection. Clinical studies and clinical experience with exenatide have shown a significant reduction in HbA1c, fasting- and postprandial glucose and a marked reduction in body weight in type 2 diabetic patients. Animal studies reveal an improvement of beta cell function and an increase in beta cell mass after exenatide treatment. This review gives an overview on exenatide, its pharmacological profile and its role and potential in the therapeutic setting of type 2 diabetes. Furthermore, future developments concerning exenatide application are highlighted.
Orally ingested glucose leads to a much higher insulin response than intravenous glucose leading to identical postprandial plasma glucose excursions. This phenomenon, termed ''incretin effect'' comprises up to 60% of the postprandial insulin secretion and is diminished in type 2 diabetes. The gastrointestinal hormones glucagon-like peptide-1 (GLP-1) and gastric inhibitory polypeptide (GIP) promote the incretin effect. Type 2 diabetes is characterized by an incretin defect: while GIP does not stimulate insulin secretion, GLP-1 action is still preserved under supraphysiological concentrations. GLP-1 stimulates insulin secretion only under hyperglycaemic conditions, therefore it does not cause hypoglycaemia. Furthermore, GLP-1 inhibits glucagon secretion and delays gastric emptying. In vitro and animal data demonstrated that GLP-1 increases beta cell mass by stimulating islet cell neogenesis and by inhibiting apoptosis of islets. The improvement of beta cell function can be indirectly observed from the increased insulin secretory capacity of humans receiving GLP-1. In contrast to GIP, GLP-1 may represent an attractive therapeutic method for type 2 diabetes due to its multiple effects also including the simulation of satiety in the central nervous system by acting as transmitter or by crossing the blood brain barrier. Native GLP-1 is degraded rapidly upon intravenous or subcutaneous administration and is therefore not feasible for routine therapy. Long-acting GLP-1 analogs (e.g. Liraglutide) and exendin-4 (Exenatide, Byetta) that are resistant to degradation, called ''incretin mimetics'' are approved (Exenatide, Byetta) or in clinical trials. DPP-4-inhibitors (e.g. Vildagliptin), Sitagliptin and Saxagliptin) that inhibit the enzyme DPP-4 responsible for incretin degradation are also under study.
AIMS/HYPOTHESIS: The insulinotropic effect of gastric inhibitory polypeptide (GIP) is reduced in patients with type 2 diabetes and around 50% of their first-degree relatives under hyperglycaemic conditions. It is unknown whether this is a result of a specific defect in GIP action or of a general reduction in beta cell function. Moreover, impaired secretion of glucagon-like peptide 1 (GLP-1) has been described in patients with type 2 diabetes. Therefore, we studied the insulinotropic effect of GIP in women with previous gestational diabetes (pGDM) under euglycaemic fasting conditions and during a hyperglycaemic clamp experiment. The secretion of GIP and GLP-1 was assessed following oral glucose ingestion. MATERIALS AND METHODS: On separate occasions we performed an OGTT and administered an i.v. bolus of 20 pmol GIP/kg body weight in 20 women with pGDM and 20 control women. An additional hyperglycaemic clamp experiment (140 mg/dl [7.8 mmol/l] over 120 min) with i.v. infusion of GIP (2 pmol kg(-1) min(-1); 30-90 min) was performed in 14 women in each group. Capillary and venous blood samples were drawn for the measurement of glucose (glucose oxidase), insulin, C-peptide, GIP and GLP-1 (specific immunoassays). Indices of insulin sensitivity and beta cell function were calculated. Statistical analyses were carried out using repeated measures ANOVA. RESULTS: Following oral glucose ingestion, plasma glucose, insulin and C-peptide concentrations increased to higher levels in the women with pGDM than in the control women (p<0.05). The women with pGDM were characterised by a higher degree of insulin resistance than the control women (p=0.007 for the Matsuda index), but showed no overt defects in glucose-stimulated insulin secretion (p=0.40 for the insulinogenic index following i.v. glucose). The secretion of GLP-1 and GIP was not different between the groups (p=0.87 and p=0.57, respectively). The insulin secretory response to GIP administration was similar in the two groups both after GIP bolus administration and during the hyperglycaemic clamp experiment (p=0.99 and p=0.88, respectively). A hyperbola-like relationship was found between the degree of insulin sensitivity (Matsuda index) and the insulin secretory response to GIP and i.v. glucose administration. CONCLUSIONS/INTERPRETATION: These results do not support the hypothesis of an early defect in GIP action as a risk factor for subsequent development of diabetes in women with previous gestational diabetes. The inverse relationship between insulin resistance and the insulin secretory response to glucose or GIP suggests that beta cell secretory function in response to different stimuli increases adaptively when insulin sensitivity is diminished.
The "incretin effect" describes the enhanced insulin response from orally ingested glucose compared with intravenous glucose leading to identical postprandial plasma glucose excursions. It makes up to 60% of the postprandial insulin secretion but is diminished in type 2 diabetes. Gastrointestinal hormones promoting the incretin effect are called incretins. Glucagon-like peptide- 1 (GLP-1) is an important incretin. In vitro and animal data have demonstrated that GLP-1 increases beta-cell mass by stimulating islet cell neogenesis and by inhibiting apoptosis of islets. The improvement of beta-cell function can be indirectly observed from the increased insulin secretory capacity of humans receiving GLP-1 or incretin mimetics that act like GLP-1. Furthermore, GLP-1 inhibits glucagon secretion and rarely causes hypoglycemia. It may represent an attractive therapeutic method for type 2 diabetes because of its multiple effects, including a slowing of gastric emptying and the simulation of satiety by acting as a transmitter in the CNS. Native GLP-1 is degraded rapidly upon intravenous or subcutaneous administration and is therefore not feasable for routine therapy. Long-acting GLP-1 analogs (e.g., Liraglutide [Novo Nordisk, Copenhagen, Denmark]) and exenadin-4 (Exenatide [Eli Lilly, Indianapolis, IN]) that are resistant to degradation, called "incretin mimetics," are being investigated in clinical trials. Dipeptidyl peptidase IV inhibitors (e.g., Vildagliptin [Novartis, Basel, Switzerland]) that inhibit the enzyme responsible for incretin degradation are also under study.
Besides classical, modifiable risk factors (hypercholesterolemia, hypertension, smoking) abnormalities of the glucose metabolism (diabetes mellitus, impaired glucose tolerance) are strong emerging cardiovascular risk factors. Epidemiological data indicate that 8 % of the population and up to 60 % of patients with coronary artery disease have abnormalities of glucose metabolism. The prevalence of these abnormalities will increase as the population ages and the mean body weight increases. An abnormal glucose concentration damages the endothelium in several ways: increased oxidative stress, inflammatory processes and an activation of procoagulant factors all impair endothelial function. A blood glucose normalising therapy is thought to decrease the incidence of cardiovascular events in these patients. In patients with an acute myocardial infarction and diabetes mellitus an early intensive insulin therapy improves the outcome of these patients. In summary, the early detection and treatment of abnormalities of glucose metabolism reduces cardiac events.
BACKGROUND/AIMS: In vitro studies suggest that glucagon-like peptide 2 (GLP-2), secreted from enteroendocrine cells in the gastrointestinal tract after food intake, is able to ameliorate mucosal injury in settings of human disease characterized by injury and dysfunction of the intestinal mucosal epithelium. We evaluated this potential of GLP-2 after epithelial trauma by using two in vitro models measuring intestinal epithelial cell proliferation and cell migration. MATERIALS AND METHODS: Injuries were induced in confluent monolayers of the small intestinal cells lines IEC-6 and IEC-18, as well as in the colonic cell lines Caco-2 and Colo 320. GLP-2 (50-500 nM) or other peptides were added to the media. Wound healing was investigated after 24 h by quantification of the number of cells migrating across the wound edge. Proliferation of cells was assessed by using photometric mitochondrial incorporation measurement of MTT (3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide). Monoclonal TGF-beta antibodies were added to wounded monolayers to examine whether the GLP-2-induced wound healing was TGF-beta-mediated. RESULTS: Migration assessments revealed a significant stimulation of GLP-2-induced migration in IEC-6 and IEC-18 monolayers compared to the placebo group. No effect was observed in the colon cancer cell lines Caco-2 and Colo 320. Results of the proliferation assays show a significant inhibition of proliferation by GLP-2 in small intestinal cell lines whereas a dose-dependent stimulation of proliferation in colonic epithelial cells was observed. Addition of neutralizing TGF-beta1 antibodies to wounded IEC-6 and IEC-18 monolayers incubated with GLP-2 significantly reduced the number of migrating cells to the level of the placebo group. CONCLUSIONS: In our in vitro model, it was shown that the GLP-2-induced improvement of intestinal wound healing is TGF-beta-mediated. These effects were predominant in the epithelium of the small intestine compared to colonic epithelium. Our findings provide further insight into mechanisms leading to GLP-2-induced mucosal wound healing. These results suggest that GLP-2 or analogues of this peptide may potentially be useful for the treatment of intestinal disorders characterized by injury and ineffective repair of the intestinal mucosa.
The increasing incidence of type 2 diabetes constitutes a considerable individual and socio-economic risk, therefore preventive concepts are urgently needed. Three prospective studies show that a "life-style-intervention" as well as drugs can prevent the development of diabetes as well as cardiovascular complications: The Diabetes Prevention Study (DPS) evaluated the influence of a "life-style-intervention". The Diabetes Prevention Program (DPP) additionally examined the effect of metformin. In the STOP-NIDDM-Study acarbose was used for diabetes prevention and cardiovascular endpoints were also evaluated. The incidence of type 2 diabetes can be significantly reduced by a "life-style-intervention" and also by the administration of metformin or acarbose. With acarbose cardiovascular events are reduced significantly and comparably to a therapy with statins in primary prevention.
Diabetes mellitus presents a significant public health burden based on its increased morbidity, mortality, and economic cost. The high comorbidity and prevalence of concomitant diseases like hypertension and dyslipidemia in diabetic patients cause the high risk in developing secondary, cost intensive, and for the patient often disastrous late complications (nephropathy, retinopathy, neuropathy, and cardiovascular disease). Therefore, patients with diabetes mellitus need a global risk management that takes the various individual clinical problems into account. The current global standards of therapy in patients with diabetes mellitus are focused on the control of glycemia, blood pressure, and lipid levels, as well as aspirin therapy and avoiding of smoking. There are a number of guidelines and recommendations to manage these global issues. Our review will summarize current recommendations and consolidate therapeutic goals and treatments that are of vital importance in the global risk management in diabetic patients.
In the UGDP study, published in the 1970s, a high incidence of cardiovascular mortality was found in patients treated with the sulfonylurea agent tolbutamide. Impaired ischaemic preconditioning is presumed to be the most important mechanism for the excess cardiovascular mortality observed. However, as tolbutamide has only a low affinity for cardiac sulfonylurea receptors, interference with ischaemic preconditioning seems unlikely to account for this excess mortality. Several smaller studies also failed to establish a definite link between sulfonylurea treatment before acute myocardial infarction and in-hospital mortality. However, when the myocardium becomes exposed to repeated or prolonged periods of ischaemia, ischaemic preconditioning may become clinically important. Myocardial ischaemia can also develop during emergency or elective angioplasty and during coronary bypass surgery. Therefore discontinuation of sulfonylurea treatment should be considered in these circumstances.
AIMS/HYPOTHESIS: In the isolated perfused pancreas, gastric inhibitory polypeptide (GIP) has been shown to enhance glucagon secretion at basal glucose concentrations, but in healthy humans no glucagonotropic effect of GIP has yet been reported. Therefore, we studied the effect of GIP on glucagon secretion under normoglycaemic conditions. METHODS: Ten healthy subjects (9 men, 1 woman; age 33+/-11; BMI 26.8+/-2.2 kg/m(2)) received three different doses of intravenous GIP (7, 20, and 60 pmol/kg body weight) and placebo. Venous blood samples were drawn over 30 min for glucagon and GIP concentrations (specific radioimmunoassays). In addition, 31 healthy subjects (16 men, 15 women; 42+/-11 years; BMI 24.4+/-2.7 kg/m(2)) were studied with 20 pmol GIP/kg. Statistics were done with RM-ANOVA and Duncan's post hoc tests. RESULTS: Gastric inhibitory polypeptide dose-dependently stimulated glucagon secretion ( p=0.019) with a maximal increment after 10 min. Incremental glucagon concentrations (Delta(10-0 min)) were 0.1+/-0.7, 1.4+/-0.5, 2.4+/-0.5, and 3.4+/-0.8 pmol/l (for placebo and for 7, 20, and 60 pmol GIP/kg, respectively; p=0.017). After the injection of 20 pmol GIP/kg b.w. in 31 healthy subjects, glucagon concentrations increased over the baseline from 7.5+/-0.5 to 9.3+/-0.7 pmol/l ( p=0.0082). CONCLUSIONS/INTERPRETATION: Glucagon secretion is dose-dependently stimulated by GIP at basal glucose concentrations. The absence of a glucagonotropic GIP effect in previous studies could be due to the hyperglycaemic conditions used in these experiments. Our results underline differences between GIP and the glucagonostatic incretin GLP-1.
Ghrelin a novel peptide consisting of 28 amino acids was first identified in the stomach in 1999. It is mainly produced in endocrine cells of the human gastric mucosa, but it was also found in several other tissues e. g. in the pituitary, the hypothalamus and the pancreas. The functional receptor belongs to the family of the 7-transmembrane G-protein receptors and is predominantly detected in the pituitary and at lower levels in hypothalamic nuclei, the stomach, heart, lungs, kidneys, gut, the adipose and many other tissues. According to the widespread distribution of the peptide and its receptor, ghrelin has multiple biological effects: it stimulates the release of growth hormone in the pituitary and induces a rise in the serum concentration of ACTH, cortisol, catecholamines and prolactin. Ghrelin causes an increase of food intake and body weight by stimulating the production of neuropeptide Y (NPY) and agouti-related protein (AGP) in the nucleus arcuatus. It further leads to elevated concentrations of plasma glucose. A physiological antagonism between ghrelin and GLP-1 in the hypothalamic regulation of appetite is being discussed. The basic serum level of ghrelin depends on the state of nutrition and is negatively correlated with the body-mass-index. It shows a certain pattern of variation before and after food intake with a preprandial increase and a postprandial decrease. Ghrelin modulates gastric acid secretion and the gastrointestinal motility via vagal cholinergic pathways. The discovery of ghrelin definitely contributes to the understanding of the growth-hormone secretion and of the regulation of appetite and food intake.