0000000000273795
AUTHOR
A. Pfützner
Prädiktive genetische Untersuchungen: Individualisierung von Diagnostik und Therapie bei Familien mit multipler endokriner Neoplasie Typ II
BACKGROUND AND OBJECTIVE When multiple endocrine neoplasia type 2 (MEN2) is suspected, genetic tests are at the centre of screening procedures. It was the aim of this study to compare the diagnostic value of molecular biological investigations with that of conventional biochemical tests. PATIENTS AND METHODS The study cohort consisted of all 144 patients cared for in our department since 1990 with the suspected diagnosis of MEN2 (evidence of a medullary thyroid carcinoma [MTC]), coexistence of two MEN2 tumours or a family history of MEN2. 14 of the 144 patients (from 12 families) were already known to have an hereditary MTC, while the remaining 130 had been referred for further diagnostic i…
The influence of local capsaicin treatment on small nerve fibre function and neurovascular control in symptomatic diabetic neuropathy.
Topical treatment with capsaicin cream has been shown to be successful in the treatment of different symptomatic nerve disorders like diabetic neuropathy. Conflicting data exist on the effect of capsaicin on nerve function and neurovascular control especially in patients with diabetic neuropathy. The aim of this pilot study was to investigate the impact of topical capsaicin application on small nerve fibre function and neurovascular control. Capsaicin cream was applied to the feet of 13 patients with symptomatic diabetic neuropathy over a period of 8 weeks. Before and during the treatment period, we investigated the total symptoms score, the vibration, thermal (heat and cold) and pain perce…
Pioglitazone in addition to metformin improves erythrocyte deformability in patients with Type 2 diabetes mellitus
The aim of the present study was to compare the effect of PIO (pioglitazone) or GLIM (glimepiride) on erythrocyte deformability in T2DM (Type 2 diabetes mellitus). The study covered 23 metformin-treated T2DM patients with an HbA1c (glycated haemoglobin) >6.5%. Patients were randomized to receive either PIO (15 mg, twice a day) or GLIM (1 mg, twice a day) in combination with metformin (850 mg, twice a day) for 6 months. Blood samples were taken for the measurement of fasting glucose, HbA1c, fasting insulin, intact proinsulin, adiponectin and Hct (haematocrit). In addition, the erythrocyte EI (elongation index) was measured using laser diffractoscopy. Both treatments significantly impr…
The effect of human proinsulin C-peptide on erythrocyte deformability in patients with Type I diabetes mellitus.
Aims/hypothesis. In recent years, evidence has arisen that proinsulin C-peptide exerts biological effects especially on microcirculation, e. g. C-peptide has been shown to increase skin microcirculation in patients with Type I (insulin-dependent) diabetes mellitus and to activate endothelial nitric oxide synthase. This study aimed to investigate the influence of proinsulin C-peptide on erythrocyte deformability which was assessed by means of laser diffractoscopy. Methods. Blood samples from healthy control subjects (n = 10) and Type I diabetic patients (n = 15) completely deficient of C-peptide were analysed at shear stresses ranging from 0.3 to 30 Pa. Results. Erythrocyte deformability was…
Adding insulin glargine vs. NPH insulin to metformin results in a more efficient postprandial β-cell protection in individuals with type 2 diabetes
AIM Postprandial release of intact proinsulin (IP) is an independent marker for beta-cell dysfunction in patients with type 2 diabetes. This open-label, parallel-group, two-arm, pilot study compared the beta-cell protective effect of adding insulin glargine (GLA) vs. NPH insulin to ongoing metformin. MATERIAL AND METHODS Overall, 28 insulin-naive type 2 diabetes subjects (mean +/- SD age, 61.5 +/- 6.7 years; diabetes duration, 9.8 +/- 6.5 years; HbA1c, 7.1 +/- 0.5%; BMI, 30.7 +/- 4.3 kg/m(2)) treated with metformin and sulfonylurea were randomized to add once-daily GLA or NPH at bedtime. At baseline and after 3 months, subjects received a standardized breakfast, lunch and dinner, with pre- …
Microvascular skin blood flow following the ingestion of 75 g glucose in healthy individuals.
It is expected that microvascular blood flow might be affected by blood glucose, blood insulin and C-peptide levels. In our investigation skin microvascular blood flow (LDF) was measured using laser doppler fluxometry at skin temperatures of 37 degrees C and 44 degrees C during a 75 g oral glucose load (OGT) or water in ten healthy volunteers (6 male, 4 female, age: 28.1+/-4.0) who had fasted overnight. The transcutaneous oxygen tension (tcPO2) was measured using a transcutaneous oxygen electrode at a temperature of 44 degrees C. The microvascular response to acetylcholine was investigated before the start of the ingestion period and after 30 minutes. In addition, the capillary blood cell v…
Architecture in cortical bone and ultrasound transmission velocity
The square of ultrasound transmission velocity in a material is correlated to the modulus of elasticity, which is an indicator of its mechanical properties. This might make the measurement of ultrasound transmission velocity useful in the noninvasive diagnosis of bone diseases. Bone, however, is not an isotropic material but is architecturally structured. The aim of our study was to investigate and especially to quantify the influence of architecture in cortical bone on ultrasound transmission velocity. Twenty-two rectangular, flat specimens of cortical bone were prepared from diaphysis of fresh pig radius. Ultrasound transmission velocity was measured parallel and perpendicular to directio…
The physiological impact of proinsulin C-peptide
Abstract The proinsulin C-peptide fulfills an important function in the biosynthesis of insulin by facilitating the formation of the correct secondary and tertiary structure of the hormone. C-peptide and insulin are released in equimolar amounts to the circulation but C-peptide has generally been considered to be biologically inert. However, recent studies indicate that C-peptide administration to type 1 diabetes patients is accompanied by improved renal function, amelioration of autonomic dysfunction, stimulated tissue glucose utilization and augmented skin and muscle blood flow. The cellular mechanisms underlying these effects may be related to C-peptide's capacity to stimulate both Na + …
Addition of liraglutide in patients with Type 2 diabetes well controlled on metformin monotherapy improves several markers of vascular function
Diabet. Med. 29, 1115–1118 (2012) Abstract Aims The aim of this study was to investigate the vascular effects of liraglutide in patients well controlled on metformin monotherapy. Methods Forty-four patients with Type 2 diabetes were included in the study. Main inclusion criteria were: pretreatment with metformin on a stable dosage, HbA1c < 53 mmol/mol (7.0%), age 30–65 years. Patients were randomized to receive additional liraglutide or to remain on metformin monotherapy. After 6 weeks (1.2 mg) and after 12 weeks (1.8 mg), venous blood was taken for the measurement of several laboratory markers characterizing vascular and endothelial function. In addition, retinal microvascular endothelia…
Binding of monocytes from normolipidemic hyperglycemic patients with type 1 diabetes to endothelial cells is increased in vitro.
Increased endothelial binding and emigration of monocytes play a dominant role in the pathogenesis of atherosclerosis in diabetes mellitus. Previous studies revealed that hyperlipidemia correlates with monocyte binding in vitro. The aim of this study was to characterize the monocyte-endothelial interaction of leucocytes of hyperglycemic patients with type 1 diabetes but lacking hyperlipidemia. We isolated monocytes from healthy controls and normolipidemic type 1 diabetes patients with elevated levels of HbA1c and quantified monocyte binding by an immunoilluminometric cell adhesion assay. Purity of isolated monocytes was at least 98%. Endothelial binding of monocytes from patients with type …
Determination of anti GAD65 autoantibodies with an ELISA before and after standardization with the new international reference serum
The serum of a stiff-man syndrome patient was declared international GAD reference standard at the "1st GAD Antibody Workshop" held at the "12th International Immunology and Diabetes Workshop" in Orlando, Florida, USA 1993. A comparative study was performed with 123 diabetic and non-diabetic patients to evaluate whether standardization of this reference serum had changed the properties of a commercially available ELISA assay. All samples classified positive with the old test were confirmed with the new assay. Four additional samples with high "normal" values became positive with the new test. One of them was a control person having a family history of diabetes and genetic loci DR4/DR11. The…
The influence of isolated small nerve fibre dysfunction on microvascular control in patients with diabetes mellitus
Aim The aim of the study was to investigate the influence of isolated small nerve fibre dysfunction on microvascular skin blood flow and transcutaneous oxygen tension in patients with diabetes mellitus. Methods Small nerve fibre dysfunction was assessed by the measurement of thermal and pain perception thresholds. Patients with evidence of large fibre disturbances as evaluated by means of vibration perception threshold were excluded from the study. Microvascular blood flow was investigated with laser-Doppler-fluxmetry (LDF) following stimulation with acetylcholine and mild thermal injury. Results Diabetic patients with small nerve fibre injury showed a significantly reduced increase in th…
Stimulation of endothelial nitric oxide synthase by proinsulin C-peptide.
There is increasing evidence for biological functions of human C-peptide. Recently, we have described that proinsulin C-peptide increases nutritive capillary blood flow and restores erythrocyte deformability in type 1 diabetic patients, whereas it has no such effect in non-diabetic subjects. The aim of the current study was to elucidate cellular mechanisms of this vasodilator effect in vitro by measuring the nitric oxide (NO)-mediated increase of cGMP production in a RFL-6 reporter cell assay and by demonstrating endothelial calcium influx with the Fluo-3 technique. C-peptide increased the release of NO from endothelial NO synthase (eNOS) in bovine aortic endothelial cells in a concentratio…
Serum levels of substance P are decreased in patients with type 1 diabetes.
Morphological and immunohistochemical studies in diabetic subjects have shown a depletion of the neuropeptide substance P (SP) in the central and peripheral nervous system. This is the first study investigating serum levels of substance P in type 1 diabetes patients (n=50) and controls (n=75) by means of an enzyme immunoassay. The serum level of SP was significantly decreased in the diabetic group compared to the control group (10.12+/-0.29 vs. 12.25+/-0.38 pg/ml; p<0.0001). In diabetic patients, there was no correlation of substance P levels with age, serum creatinine, albuminuria, total cholesterol, HDL- or LDL-cholesterol, triglycerides, HbA1c, type or duration of diabetes and gender. Fu…
Bone Mineral Density and Bone Metabolism in Diabetes Mellitus
The effect of diabetes mellitus on bone metabolism and bone mineral density is discussed controversially. Diabetes mellitus due to an autoimmune process seems to be associated with low turnover osteopenia either in the animal model or in children and adolescents. A number of factors are discussed as being involved, but in this age group clinical symptoms are missing. Adult patients of either sex with IDDM show a reduced bone mineral density when measured at peripheral sites such as the distal forearm or the femoral neck, diabetic complications such as neuropathy and microangiopathy seem to pronounce the deficit of bone mass. In these patients, osteopenia is accompanied by a high turnover si…
Effect of vildagliptin compared to glimepiride on postprandial proinsulin processing in the β cell of patients with type 2 diabetes mellitus
This study compared the effect of Glimepiride versus Vildagliptin on β-cell function and the release of intact proinsulin (PI) in patients with type 2 diabetes mellitus. Patients on metformin monotherapy were randomized to add on treatment with Vildagliptin or Glimepiride. A standardized test meal was given at baseline, after 12 and 24 weeks of treatment. Insulin, PI and blood glucose values were measured in the fasting state and postprandial for 300 min. Fasting PI levels significantly decreased in the Vildagliptin group. The area under the curve for the postprandial release of PI decreased during Vildagliptin and increased during Glimepiride treatment. The proinsulin to insulin ratio decl…
Auswahl richtet sich nach Evidenz und potenziellen Nebeneffekten
Die schmerzhafte diabetische Polyneuropathie (DPN) ist eine schwerwiegende Komplikation eines Diabetes mellitus. Sie schrankt die Lebensqualitat der betroffenen Patienten stark ein. Eine effektive Therapie bei schmerzhafter DPN ist fur Patienten und Therapeuten eine Herausforderung. Viele mehr oder minder gut untersuchte Medikamente werden hierbei eingesetzt. Aber lediglich fur Duloxetin, Gabapentin und Pregabalin liegt eine spezifische Zulassung in dieser Indikation vor. Die schmerzreduzierenden Eigenschaften dieser Substanzen sind laut einer kurzlich publizierten Metaanalyse ahnlich, sodass sich die Auswahl an den zu erwartenden Nebenwirkungen orientieren sollte.
Serum leptin is associated with serum uric acid concentrations in humans.
This cross-sectional study aimed to evaluate the relationship between leptin and the cluster of abnormalities often referred to as the metabolic syndrome. The serum leptin concentration, body mass index (BMI), percent body fat, total fat mass (FM), waist and hip circumference, waist to hip ratio (WHR), prevalence of hypertension, and triglyceride (TG), lipoprotein, and uric acid concentration were determined in 86 type 2 diabetic (n = 59) and healthy (n = 27) subjects. Multiple regression analyses showed that the estimates of total body obesity (BMI, percent body fat, and total FM), sex, and serum uric acid concentration are independently associated with the serum leptin concentration. The …
The influence of advanced glycation endproducts (AGE) on the expression of human endothelial adhesion molecules.
Advanced glycation endproducts (AGEs) possibly play a dominant role in the pathogenesis of macrovascular disease in diabetes. Recent studies could demonstrate that glycated albumin (AGE-BSA) was able to stimulate vascular cell adhesion molecule-1 (VCAM.1) on endothelial cells. The aim of this study was to find out if AGE-BSA was not only able to enhance the expression of vascular cell adhesion molecule-1, but also of intercellular adhesion molecule-1 (ICAM-1) and E-Selectin on human endothelial cells. Stimulation of endothelial cells with AGE-BSA for six hours predominantly increased the expression of VCAM-1, but ICAM-1 and E-Selectin were also upregulated as shown by immunoilluminometric a…
Elevated serum leptin concentrations in type 2 diabetic patients with microalbuminuria and macroalbuminuria
Leptin levels are elevated in end-stage renal disease, suggesting an impairment of renal leptin degradation. The present study aimed to determine whether leptin levels are also elevated in patients with earlier stages of renal disease, ie, microalbuminuric and macroalbuminuric nephropathy. A total of 60 subjects were assigned to two study groups. Group A contained 10 type 2 diabetics with macroalbuminuria, 10 type 2 diabetics with normoalbuminuria, and 10 healthy control subjects. Group B contained 10 type 2 diabetics with microalbuminuria, 10 type 2 diabetics with normoalbuminuria, and 10 healthy controls. The subgroups of both study groups were matched for sex and body fatness. In group A…
Effects of proinsulin C-peptide on nitric oxide, microvascular blood flow and erythrocyte Na+,K+-ATPase activity in diabetes mellitus type I
This study was conducted to evaluate the influence of proinsulin C-peptide on erythrocyte Na(+),K(+)-ATPase and endothelial nitric oxide synthase activities in patients with type I diabetes. In a randomized double-blind study design, ten patients with type I diabetes received intravenous infusions of either human C-peptide or physiological saline on two different occasions. C-peptide was infused at a rate of 3 pmol.min(-1).kg(-1) for 60 min, and thereafter at 10 pmol.min(-1).kg(-1) for 60 min. At baseline and after 60 and 120 min, laser Doppler flow (LDF) was measured following acetylcholine iontophoresis or mild thermal stimulation (44 degrees C), and venous blood samples were collected to…