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| 2. |
- Ahrén, Bo, et al.
(författare)
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Improved meal-related beta-cell function and insulin sensitivity by the dipeptidyl peptidase-IV inhibitor vildagliptin in metformin-treated patients with type 2 diabetes over 1 year.
- 2005
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Ingår i: Diabetes Care. - : American Diabetes Association. - 1935-5548 .- 0149-5992. ; 28:8, s. 1936-1940
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE—To examine the effects of dipeptidyl peptidase-IV (DPP-4) inhibition on meal-related β-cell function and insulin sensitivity over 52 weeks in type 2 diabetes. RESEARCH DESIGN AND METHODS—In a 12-week core study, placebo (n = 51) or vildagliptin (n = 56; 50 mg OD) was added to metformin treatment (1.5–3.0 mg/day). A 40-week extension followed in 71 patients. Meal tests were performed at 0, 12, 24, and 52 weeks; glucose, insulin, and C-peptide were evaluated. RESULTS—In subjects completing 52 weeks with participation in all meal tests (n = 57), HbA1c (A1C) decreased in the vildagliptin/metformin group (VM group, n = 31) but increased in the placebo/metformin group (PM group, n = 26; between-group difference −1.0 ± 0.2%; P < 0.001; baseline of all subjects combined 7.7 ± 0.1%). Also, fasting glucose decreased in the VM group but increased in the PM group (difference −0.9 ± 0.3 mmol/l, P = 0.016; baseline 9.8 ± 0.3 mmol/l). Insulin secretion (postmeal suprabasal area under the 0- to 30-min C-peptide curve divided by the 30-min increase in glucose) was increased in the VM group but was reduced in the PM group (difference +0.011 ± 0.03 pmol/l 30 min/mmol/l, P = 0.018; baseline 0.036 ± 0.02). Insulin sensitivity during meal ingestion (oral glucose insulin sensitivity) increased in the VM group but was not altered in the PM group (difference +27 ± 4 ml · min−1 · m−2, P = 0.036; baseline 246 ± 6). Insulin secretion related to insulin sensitivity (adaptation index) increased in the VM group but decreased in the PM group (difference +3.2 ± 1.0, P = 0.040; baseline 9.1 ± 0.5). The change in adaptation index correlated to the change in A1C (r = −0.39, P = 0.004). CONCLUSIONS—This study presents evidence that DPP-4 inhibition by vildagliptin when added to metformin in type 2 diabetes over 52 weeks improves β-cell function along with improved postmeal insulin sensitivity.
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| 3. |
- Ahrén, Bo, et al.
(författare)
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Inhibition of dipeptidyl peptidase-4 augments insulin secretion in response to exogenously administered glucagon-like peptide-1, glucose-dependent insulinotropic polypeptide, pituitary adenylate cyclase-activating polypeptide, and gastrin-releasing peptide in mice
- 2005
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Ingår i: Endocrinology. - : The Endocrine Society. - 0013-7227 .- 1945-7170. ; 146:4, s. 2055-2059
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Tidskriftsartikel (refereegranskat)abstract
- Inhibition of dipeptidyl peptidase- 4 ( DPP- 4) is currently being explored as a new approach to the treatment of type 2 diabetes. This concept has emerged from the powerful and rapid action of the enzyme to inactivate glucagon- like peptide-1 ( GLP- 1). However, other bioactive peptides with potential influence of islet function are also substrates of DPP- 4. Whether this inactivation may add to the beneficial effects of DPP- 4 inhibition is not known. In this study, we explored whether DPP- 4 inhibition by valine- pyrrolidide ( val- pyr; 100 mu mol/ kg administered through gastric gavage at t = -30 min) affects the insulin and glucose responses to iv glucose ( 1 g/ kg) together with GLP- 1 ( 10 nmol/ kg), glucose- dependent insulinotropic polypeptide ( GIP; 10 nmol/ kg), pituitary adenylate cyclase- activating polypeptide 38 ( PACAP38; 1.3 nmol/ kg), or gastrin- releasing peptide ( GRP; 20 nmol/ kg) given at t = 0 in anesthetized C57BL/ 6J mice. It was found that the acute ( 1 - 5 min) insulin response to GLP- 1 was augmented by val- pyr by 80% ( 4.2 +/- 0.4 vs. 7.6 +/- 0.8 nmol/ liter), that to GIP by 40% ( 2.7 +/- 0.3 vs. 3.8 +/- 0.4 nmol/ liter), that to PACAP38 by 75% ( 4.6 +/- 0.5 vs. 8.1 +/- 0.6 nmol/ liter), and that to GRP by 25% ( 1.8 +/- 0.2 vs. 2.3 +/- 0.3 nmol/ liter; all P < 0.05 or less). This was associated with enhanced glucose elimination rate after GLP- 1 [ glucose elimination constant ( K-G) 2.1 +/- 0.2 vs. 3.1 +/- 0.3%/ min] and PACAP38 ( 2.1 +/- 0.3 vs. 3.2 +/- 0.3%/ min; both P < 0.01), but not after GIP or GRP. The augmented insulin response to GRP by val- pyr was prevented by the GLP- 1 receptor antagonist, exendin(3) ( 9- 39), raising the possibility that GRP effects may occur secondary to stimulation of GLP- 1 secretion. We conclude that DPP- 4 inhibition augments the insulin response not only to GLP- 1 but also to GIP, PACAP38, and GRP.
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| 6. |
- Bohlooly-Yeganeh, Mohammad, 1966, et al.
(författare)
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Growth hormone overexpression in the central nervous system results in hyperphagia-induced obesity associated with insulin resistance and dyslipidemia.
- 2005
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Ingår i: Diabetes. - 0012-1797 .- 1939-327X. ; 54:1, s. 51-62
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Tidskriftsartikel (refereegranskat)abstract
- It is well known that peripherally administered growth hormone (GH) results in decreased body fat mass. However, GH-deficient patients increase their food intake when substituted with GH, suggesting that GH also has an appetite stimulating effect. Transgenic mice with an overexpression of bovine GH in the central nervous system (CNS) were created to investigate the role of GH in CNS. This study shows that overexpression of GH in the CNS differentiates the effect of GH on body fat mass from that on appetite. The transgenic mice were not GH-deficient but were obese and showed increased food intake as well as increased hypothalamic expression of agouti-related protein and neuropeptide Y. GH also had an acute effect on food intake following intracerebroventricular injection of C57BL/6 mice. The transgenic mice were severely hyperinsulinemic and showed a marked hyperplasia of the islets of Langerhans. In addition, the transgenic mice displayed alterations in serum lipid and lipoprotein levels and hepatic gene expression. In conclusion, GH overexpression in the CNS results in hyperphagia-induced obesity indicating a dual effect of GH with a central stimulation of appetite and a peripheral lipolytic effect.
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| 7. |
- Borch, Kurt, 1944-, et al.
(författare)
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Gastric carcinoids: biologic behavior and prognosis after differentiated treatment in relation to type
- 2005
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Ingår i: Annals of surgery. - : Ovid Technologies (Wolters Kluwer Health). - 0003-4932 .- 1528-1140. ; 242:1, s. 64-73
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To analyze tumor biology and the outcome of differentiated treatment in relation to tumor subtype in patients with gastric carcinoid. BACKGROUND: Gastric carcinoids may be subdivided into ECL cell carcinoids (type 1 associated with atrophic gastritis, type 2 associated with gastrinoma, type 3 without predisposing conditions) and miscellaneous types (type 4). The biologic behavior and prognosis vary considerably in relation to type. METHODS: A total of 65 patients from 24 hospitals (51 type 1, 1 type 2, 4 type 3, and 9 type 4) were included. Management recommendations were issued for newly diagnosed cases, that is, endoscopic or surgical treatment of type 1 and 2 carcinoids (including antrectomy to abolish hypergastrinemia) and radical resection for type 3 and 4 carcinoids. RESULTS: Infiltration beyond the submucosa occurred in 9 of 51 type 1, 4 of 4 type 3, and 7 of 9 type 4 carcinoids. Metastases occurred in 4 of 51 type 1 (3 regional lymph nodes, 1 liver), the single type 2 (regional lymph nodes), 3 of 4 type 3 (all liver), and 7 of 9 type 4 carcinoids (all liver). Of the patients with type 1 carcinoid, 3 had no specific treatment, 40 were treated with endoscopic or surgical excision (in 10 cases combined with antrectomy), 7 underwent total gastrectomy, and 1 underwent proximal gastric resection. Radical tumor removal was not possible in 2 of 4 patients with type 3 and 7 of 9 patients with type 4 carcinoid. Five- and 10-year crude survival rates were 96.1% and 73.9% for type 1 (not different from the general population), but only 33.3% and 22.2% for type 4 carcinoids. CONCLUSION: Subtyping of gastric carcinoids is helpful in the prediction of malignant potential and long-term survival and is a guide to management. Long-term survival did not differ from that of the general population regarding type 1 carcinoids but was poor regarding type 4 carcinoids.
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| 8. |
- Evilevitch, L., et al.
(författare)
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Three-Day Enteral Exposure to a Red Kidney Bean Lectin Preparation Enhances the Pancreatic Response to CCK Stimulation in Suckling Pigs.
- 2005
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Ingår i: Biology of the Neonate. - : S. Karger AG. - 1421-9727. ; 87:1, s. 20-25
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Tidskriftsartikel (refereegranskat)abstract
- Background: A reason for the digestive problems that often occur around early weaning in piglets could be that the pancreas is not yet fully developed and the enzymes required for degradation of the solid food are not secreted in enough amounts. Objectives: The aim of the study was to investigate the possibility of inducing pancreas maturation with enhanced enzyme secretion. Methods: 10-day-old suckling pigs were gavage fed with a red kidney bean lectin preparation for 3 days, and the pancreatic response to intravenous infusion of CCK-33 was measured in the anaesthetized animals fitted with pancreatic duct catheters. Results: The pancreatic fluid secretion, protein output, and the trypsin and amylase outputs were significantly increased in response to CCK stimulation after the lectin treatment, as compared to those of the control littermates (p le 0.05). In addition, the plasma insulin basal levels and those observed during CCK-33 stimulation were lower in the lectin-treated piglets. Conclusion: The results suggested that the lectin treatment led to an increase in the capacity for pancreatic enzyme secretion in the suckling piglets. An enhanced pancreatic function might help to ameliorate the problems that may appear in modern pig production which are associated with weaning.
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| 9. |
- Gram, DX, et al.
(författare)
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Plasma calcitonin gene-related peptide is increased prior to obesity, and sensory nerve desensitization by capsaicin improves oral glucose tolerance in obese Zucker rats
- 2005
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Ingår i: European Journal of Endocrinology. - : Oxford University Press (OUP). - 1479-683X .- 0804-4643. ; 153:6, s. 963-969
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Tidskriftsartikel (refereegranskat)abstract
- Objective: It has earlier been demonstrated that capsaicin-induced desensitization improves insulin sensitivity in normal rats. However, whether increased capsaicin-sensitive nerve activity precedes the onset of insulin resistance in diet-induced obesity - and therefore might be involved in the pathophysiology - is not known. Further, it is of relevance to investigate whether capsaicin desensitization improves glycaemic control even in obese individuals and we therefore chose the obese Zucker rats to test this. Design and methods: Plasma levels of calcitonin gene-related peptide (CGRP; a marker of sensory nerve activity) was assessed in 8-week-old Zucker rats. To investigate whether capsaicin desensitization (100 mg/kg at 9 weeks of age) would also ameliorate glycaemia in this non-diabetic model, we assessed oral glucose tolerance at 7 weeks after capsaicin. Results: It was found that plasma CGRP levels were elevated in obese Zucker rats prior to the onset of obesity (16.1 +/- 3.4 pmol/l in pre-obese Zucker rats vs 6.9 +/- 1.1 pmol/l in lean littermates; P = 0.015) despite similar body weights. Furthermore, capsaicin desensitization reduced both fasting blood glucose (4.3 +/- 0.2 mmol/l vs 5.1 +/- 0.2 mmol/l in controls; P = 0.050) as well as the mean blood glucose level during an oral glucose tolerance test (OGTT) (6.8 +/- 0.3 mmol/l vs 8.6 +/- 0.5 mmol/l in control obese rats; P = 0.024) whereas the plasma insulin levels during the OGTT were unchanged. However this did not lead to an improvement in insulin resistance or to a reduction of tissue triglyceride accumulation in muscle or liver. Conclusion: We concluded that capsaicin-induced sensory nerve desensitization improves glucose tolerance in Zucker rats. Since, in this study, plasma CGRP levels, a marker of sensory nerve activity, were increased in the pre-obese rats, our data support the hypothesis that increased activity of sensory nerves precedes the development of obesity and insulin resistance in Zucker rats.
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| 10. |
- Gram, DX, et al.
(författare)
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Sensory nerve desensitization by resiniferatoxin improves glucose tolerance and increases insulin secretion in Zucker diabetic fatty rats and is associated with reduced plasma activity of dipeptidyl peptidase IV
- 2005
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Ingår i: European Journal of Pharmacology. - : Elsevier BV. - 1879-0712 .- 0014-2999. ; 509:2-3, s. 211-217
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Tidskriftsartikel (refereegranskat)abstract
- Sensory nerve desensitization by capsaicin has been shown to improve the diabetic condition in Zucker Diabetic Fatty rats. However, administration of capsaicin to adult rats is associated with an increased mortality. Therefore, in this experiment, we examined the influence of resiniferatoxin, a tolerable analogue of capsaicin suitable for in vivo use, on the diabetic condition of Zucker Diabetic Fatty rats. A single subcutaneous injection of resiniferatoxin (0.01 mg/kg) to these rats was tolerable, with no mortality. When administered to early diabetic rats at 15 weeks of age, the further deterioration of glucose homeostasis was prevented by resiniferatoxin. Further, when administered to overtly diabetic rats at 19 weeks of age, resiniferatoxin markedly improved glucose tolerance at two weeks after administration and this was accompanied by an increased insulin response to oral glucose as well as a reduction in the plasma levels of dipeptidyl peptidase IV. Therefore, resiniferatoxin is a safe alternative to capsaicin for further investigations of the role of the sensory nerves in experimental diabetes.
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