Papers by Wolfgang Kerner
Die Ophthalmologie, 2022
Zusammenfassung Hintergrund Seit 2018 ist mit IDx-DR ein Verfahren auf dem Markt, welches den Gra... more Zusammenfassung Hintergrund Seit 2018 ist mit IDx-DR ein Verfahren auf dem Markt, welches den Grad der diabetischen Retinopathie (DR) mittels künstlicher Intelligenz (KI) bestimmt. Methoden Wir haben IDx-DR in die Sprechstunde an einer diabetologischen Schwerpunktklinik integriert und berichten über die Übereinstimmung zwischen IDx-DR (IDx Technologies Inc., Coralville, IA, USA) und Funduskopie sowie IDx-DR und ophthalmologischer Bildbeurteilung sowie über den Einfluss unterschiedlicher Kamerasysteme. Ergebnisse Mit der Topcon-Kamera (n = 456; NW400, Topcon Medical Systems, Oakland, NJ, USA) konnte im Vergleich zur Zeiss-Kamera (n = 47; Zeiss VISUCAM 500, Carl Zeiss Meditec AG, Jena, Deutschland) häufiger eine ausreichende Bildqualität in Miosis erreicht werden. Insgesamt war bei etwa 60 % der Patienten eine IDx-DR-Analyse in Miosis möglich. Alle Patienten, bei denen keine IDx-DR-Analyse in Miosis möglich war, konnten in Mydriasis funduskopiert werden. Innerhalb der Gruppe der auswe...
Diabetologie und Stoffwechsel, 2006
Klinische Wochenschrift, 1989
An amperometric enzyme electrode and a wick technique were used for measurement of glucose in sc.... more An amperometric enzyme electrode and a wick technique were used for measurement of glucose in sc. tissue of sheep. When wicks were left implanted long enough to equilibrate with interstitial fluid, sc. glucose could have been reproducibly determined with the necessary accuracy. It was demonstrated that sc. tissue glucose concentrations in sheep are about 30% higher than in whole blood and are on the level of plasma glucose. This allows interpretation of sc. glucose sensor currents since results of in vitro-calibrations cannot be transferred to in vivo conditions. When an enzymatic sensor was implanted in the sc. compartment, the sensor signals were closely related to changes of blood glucose. These in vivo experiments indicate that short term glucose-monitoring with an subcutaneously implantable glucose sensor is feasible and so may provide a possible access to glycemic control. Further experiments will have to show, if glucose-controlled insulin infusions based on the output of a sc. glucose sensor will be able to maintain stable normoglycemia.
Diabetic Medicine, 1995
The influence of insulin binding antibodies on the pharmacokinetics of NPH insulin was studied in... more The influence of insulin binding antibodies on the pharmacokinetics of NPH insulin was studied in Type 1 diabetic patients on human insulin. Insulin-antibody binding (B,) was measured during a screening procedure in 155 Type 1 diabetic patients. In 36 patients, B, was <1.5 %, and in 38 patients B, was >10.0 %. Of these, 6 patients, group 1 (B, < 1.5 YO) and 8 patients, group 2 (B,, > 10.0 YO), respectively, subsequently participated in a pharmacokinetic study. Free insulin and the glucose infusion rate were measured using a euglycaemic clamp after subcutaneous injection of NPH insulin (0.4 U kg-'). The areas under the curve (AUC) of free insulin concentration were smaller for group 2 (p = 0.01) than for group 1 (212.2 & 22.0 vs 316.8 f 25.3 mU I-' h). The AUCs of the glucose infusion rate were also smaller for group 2 (p < 0.05) than for group 1 (2.50 f 0.32 vs 3.58 f 0.36 g kg-'). A significant negative correlation exists between the AUCs for free insulin concentration and insulin-antibody binding B, (r = 0.76, p = 0.001). The daily insulin dosage was higher in group 2 (p = 0.02) than in group 1 (0.66 f 0.03 vs 0.53 f 0.03 U kg-I). We conclude that insulin antibodies influence the pharmacokinetics of NPH human insulin. The demonstrable influence on the kinetics of free insulin and glucose utilization leads to a slight increase in daily total insulin requirements. KEY WORDS Antibody-bound insulin Free insulin Human NPH insulin Euglycaemic clamp Screening of Diabetic Patients One hundred and fifty-five Type 1 diabetic patients on human insulin for at least 6 months were screened for the presence of insulin antibodies. Mean age (SEM)
Fresenius' Zeitschrift f�r Analytische Chemie, 1970
Methods are described for the chromatographic resolution of peptides at the 10–200 nanomole range... more Methods are described for the chromatographic resolution of peptides at the 10–200 nanomole range. Separation is achieved on 0.1×50 cm capillary columns with a sulfonated polystyrene cation-exchanger or with the anion-exchanger QAE-Sephadex. The columns are eluted by suitable gradients of pH and salt at a flowrate of 0.4 ml per hour.
Diabetologie und Stoffwechsel, 2014
Diabetologie und Stoffwechsel, 2016
Hormone and metabolic research. Supplement series, 1988
A membrane limited amperometric enzyme electrode suitable for glucose measurement in biological f... more A membrane limited amperometric enzyme electrode suitable for glucose measurement in biological fluids was developed. The sensor consists of a central platinum wire (0.3 mm) surrounded by a stainless steel tubing (0.8-1.0 mm outer diameter; 2-4 cm length). By successive dipcoating procedures, layers from cellulose acetate, glucose oxidase (crosslinked with glutaraldehyde) and polyurethane are placed on its surface. The platinum is polarized at +700 mV against steel. In vitro results: Electrodes are stable for at least 6 days. They exhibit a linear range extending to 500 mg/dl glucose. Response times are less than 100 sec. The sensors are not dependent on stirring and are relatively insensitive to changes of pH. Dependency of glucose measurement upon dissolved oxygen is negligible at oxygen concentrations above 0.5 mg/l. In vivo results: Preliminary studies in sheep using subcutaneously implanted needles indicate that short term glucose monitoring is feasible.
Experimental and Clinical Endocrinology & Diabetes, 2010
excess visceral fat as a central component of cardiovascular risk. Thus, abdominal obesity often ... more excess visceral fat as a central component of cardiovascular risk. Thus, abdominal obesity often is associated with insulin resistance, hyperglycemia, dyslipidemia, hypertension, and prothrombotic and proinfl ammatory states (Whitlock et al., 2009 ; McGill et al., 2002 ; Fontaine et al., 2003 ; Despr é s et al., 2001). Weight loss intervention should therefore represent an important tool in the therapy for patients with T2DM in order to improve glycemic control and to reduce cardiovascular risk factors. However, several recent studies demonstrate that patients treated for T2DM frequently stay obese or even gain weight (
Endocrine Journal, 2006
Increased intracellular calcium concentrations ([Ca 2+ ] i) and enhanced sodium-lithium countertr... more Increased intracellular calcium concentrations ([Ca 2+ ] i) and enhanced sodium-lithium countertransport (Na/Li CT) activities may play a role in the development of diabetic complications such as diabetic nephropathy. The present study was designed to test the hypothesis that albuminuria in patients with type 2 diabetes is associated with increased [Ca 2+ ] i in response to stimulation with platelet-activating factor (PAF) or with enhanced Na/Li CT activities. The study population comprised 203 type 2 diabetic patients. Albuminuria was defined as an albumin excretion rate exceeding 30 mg/d (117 cases). PAF-evoked rises in [Ca 2+ ] i and Na/Li CT activities were determined in Epstein-Barr-virusimmortalized lymphoblasts. Albuminuria was related to high stimulated [Ca 2+ ] i but not to high basal [Ca 2+ ] i. The association was independent of age, sex and several non-diabetes related confounders, but depended on diabetes-related factors, such as the duration of diabetes. The risk of albuminuria was highest in subjects with high [Ca 2+ ] i who reported a diabetes duration of ≤10 years. There was no association between Na/Li CT activities and albuminuria. The present results support the hypothesis that albuminuria in type 2 diabetic patients is associated with a primary defect in intracellular calcium homeostasis. The association between stimulated [Ca 2+ ] i and albuminuria is most prominent in early diabetes.
British Journal of Ophthalmology, 2000
Aim-To examine possible relation between diabetic maculopathy and various risk factors for diabet... more Aim-To examine possible relation between diabetic maculopathy and various risk factors for diabetic complications in patients with diabetes mellitus type 1 and type 2. Methods-Cross sectional study of two cohorts of diabetic patients, comprising 1796 patients with type 1 diabetes (mean age 47 years, mean duration of diabetes 24 years) and 1563 patients with type 2 diabetes (mean age 62 years, mean duration of diabetes 16 years). Retinopathy levels (R0-RV) and maculopathy were assessed by fluorescence angiography and fundus photography and binocular biomicroscopy. Diabetic neuropathy was assessed by means of computer assisted electrocardiography and by thermal and vibratory sensory examination. Patients were classified as normoalbuminuric (<20 µg/min) or microalbuminuric (20-200 µg/min) according to their albumin excretion rates measured in urine collected overnight. Using univariate analyses, the eVects of selected patient characteristics on the presence of maculopathy were evaluated. Multiple logistic regression analyses were performed to determine independent eVects of risk variables on diabetic maculopathy. Results-Background retinopathy (RII) was found to be present in 28% of type 1 diabetic patients and in 38% of type 2 diabetic patients. The prevalence of maculopathy in these patients was remarkably high (42% in type 1 and 53% in type 2 diabetic patients). Patients with maculopathy had significantly impaired visual acuity. Multiple logistic correlation analysis revealed that in both types of diabetes maculopathy exhibited independent associations with duration of diabetes and with neuropathy (p <0.01); in type 1 diabetic patients there were significant associations with age at diabetes onset, serum triglyceride and total cholesterol levels (p <0.05); in type 2 diabetes with serum creatinine levels and with hypertension (p <0.05). Conclusions-Irrespective of the type of diabetes, diabetic patients with long standing diabetes have a high risk for the development of diabetic maculopathy. Diabetic maculopathy is closely associated with diabetic nephropathy and neuropathy and with several atherosclerotic risk factors which suggests that these factors might have an important role in the pathogenesis of maculopathy. However, prospective trials are necessary to evaluate the predictive value of such factors. The findings of the present cross sectional study reinforce the arguments of previous studies by others for tight control of hypertension and hyperglycaemia.
The American Journal of Human Genetics, 2007
Type 2 diabetes (T2D) is a common, polygenic chronic disease with high heritability. The purpose ... more Type 2 diabetes (T2D) is a common, polygenic chronic disease with high heritability. The purpose of this whole-genome association study was to discover novel T2D-associated genes. We genotyped 500 familial cases and 497 controls with 1300,000 HapMap-derived tagging single-nucleotide-polymorphism (SNP) markers. When a stringent statistical correction for multiple testing was used, the only significant SNP was at TCF7L2, which has already been discovered and confirmed as a T2D-susceptibility gene. For a replication study, we selected 10 SNPs in six chromosomal regions with the strongest association (singly or as part of a haplotype) for retesting in an independent case-control set including 2,573 T2D cases and 2,776 controls. The most significant replicated result was found at the AHI1-LOC441171 gene region.
Cardiovascular Diabetology, 2013
Background: Previous studies suggested an impaired endothelial function in patients with diabetes... more Background: Previous studies suggested an impaired endothelial function in patients with diabetes. However, the validity of this finding may be limited by the lack of adequate adjustment for further cardiovascular confounders. We assessed endothelial function as measured by flow-mediated dilation (FMD) of the brachial artery in patients with either type 1 or type 2 diabetes in comparison with non-diabetic controls. Methods: The study population comprised 1487 subjects including 122 subjects with type 2 diabetes, aged 25 to 85, from the population-based Study of Health in Pomerania, and 65 outpatients, aged 23 to 75, with type 1 diabetes. FMD measurements were performed using standardized ultrasound techniques. Subjects with type 1 and type 2 diabetes were matched 1:4 to healthy controls using propensity score matching. Results: Neither type 1 diabetes (β = 0.142; SE = 0.568, p = 0.803) nor type 2 diabetes (β = 0.107; SE = 0.340, p = 0.752) were significantly associated with FMD in comparison with their non-diabetic controls after adjustment for major cardiovascular confounders like age, gender, body mass index, smoking status, hypertension, antihypertensive medication, LDL and HDL cholesterol levels. Conclusions: In this population-based study comparing adjusted FMD values of diabetic individuals with adequately matched controls, propensity score analyses revealed no association between diabetes and endothelial function. Since these findings are in discordance with the majority of previous reports, we suggest performing similar analyses using data from other population-based studies.
Diabetologie und Stoffwechsel
DMW - Deutsche Medizinische Wochenschrift
Uploads
Papers by Wolfgang Kerner