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1.
Diabet Med ; 28(2): 199-205, 2011 Feb.
Article in English | MEDLINE | ID: mdl-21219430

ABSTRACT

OBJECTIVES: The incidence of minor amputation may vary significantly, and determinants of minor amputation have not been studied systematically. We evaluated minor amputation rate, the determinants of minor amputation and differences in amputation rate between European centres. METHODS: In the Eurodiale study, a prospective cohort study of 1232 patients (1088 followed until end-point) with a new diabetic foot ulcer were followed on a monthly basis until healing, death, major amputation or up to a maximum of 1 year. Ulcers were treated according to international guidelines. Baseline characteristics independently associated with minor amputation were examined using multiple logistic regression modelling. Based on the results of the multivariable analysis, a disease severity score was calculated for each patient. RESULTS: One hundred and ninety-four (18%) patients underwent a minor amputation. Predictors of minor amputation were depth of the ulcer (odds ratio 6.08, confidence interval 4.10-9.03), peripheral arterial disease (odds ratio 1.84, confidence interval 1.30-2.60), infection (odds ratio 1.56, confidence interval 1.05-2.30) and male sex (odds ratio 1.42, confidence interval 0.99-2.04). Minor amputation rate varied between 2.4 and 34% in the centres. Minor amputation rate in centres correlated strongly with disease severity score at the moment of presentation to the foot clinic (r=0.75). CONCLUSIONS: Minor amputation is performed frequently in diabetic foot centres throughout Europe and is determined by depth of the ulcer, peripheral arterial disease, infection and male sex. There are important differences in amputation rate between the European centres, which can be explained in part by severity of disease at presentation. This may suggest that early referral to foot clinics can prevent minor amputations.


Subject(s)
Amputation, Surgical/statistics & numerical data , Diabetic Foot/surgery , Diabetic Neuropathies/surgery , Aged , Confidence Intervals , Diabetic Foot/epidemiology , Diabetic Foot/physiopathology , Diabetic Neuropathies/epidemiology , Diabetic Neuropathies/physiopathology , Europe/epidemiology , Female , Humans , Male , Middle Aged , Odds Ratio , Practice Guidelines as Topic , Prospective Studies , Severity of Illness Index
2.
Ned Tijdschr Geneeskd ; 152(44): 2400-5, 2008 Nov 01.
Article in Dutch | MEDLINE | ID: mdl-19055139

ABSTRACT

A foot ulcer is a complication that is difficult to treat in people with diabetes mellitus. Over the past few years, both clinicians and scientists have been showing more interest in this condition. A number of factors are involved in the development and maintenance of a diabetic foot ulcer, including: polyneuropathy, mechanical overload, peripheral arterial disease and infection. The cornerstones of treatment are: relief of pressure, the restoration of perfusion ofthe foot, treatment of infection, wound care, optimum glucose regulation and education. New and effective methods of treatment have become available. These include a non-removable plaster cast that is modelled to the form of the foot (a 'total contact cast'), endovascular revascularisation procedures in the lower leg, and topical application of negative pressure.


Subject(s)
Diabetic Foot/therapy , Foot/blood supply , Wounds and Injuries/therapy , Casts, Surgical , Diabetic Foot/physiopathology , Diabetic Foot/surgery , Foot/pathology , Humans , Male , Middle Aged , Prognosis , Treatment Outcome , Vascular Surgical Procedures
3.
Diabetologia ; 51(10): 1826-34, 2008 Oct.
Article in English | MEDLINE | ID: mdl-18648766

ABSTRACT

AIMS/HYPOTHESIS: The aim of the present study was to investigate resource utilisation and associated costs in patients with diabetic foot ulcers and to analyse differences in resource utilisation between individuals with or without peripheral arterial disease (PAD) and/or infection. METHODS: Data on resource utilisation were collected prospectively in a European multicentre study. Data on 1,088 patients were available for the analysis of resource use, and data on 821 patients were included in the costing analysis. Costs were calculated for each patient by multiplying the country-specific direct and indirect unit costs by the number of resources used from inclusion into the study up to a defined endpoint. Country-specific costs were converted into purchasing power standards. RESULTS: Resource use and costs varied between outcome groups and between disease severity groups. The highest costs per patient were for hospitalisation, antibiotics, amputations and other surgery. All types of resource utilisation and costs increased with the severity of disease. The total cost per patient was more than four times higher for patients with infection and PAD at inclusion than for patients in the least severe group, who had neither. CONCLUSIONS/INTERPRETATION: Important differences in resource use and costs were found between different patient groups. The costs are highest for individuals with both peripheral arterial disease and infection, and these are mainly related to substantial costs for hospitalisation. In view of the magnitude of the costs associated with in-hospital stay, reducing the number and duration of hospital admissions seems an attractive option to decrease costs in diabetic foot disease.


Subject(s)
Diabetic Foot/economics , Health Care Costs , Adult , Aged , Aged, 80 and over , Costs and Cost Analysis , Diabetic Foot/drug therapy , Diabetic Foot/therapy , Europe , Female , Humans , Male , Middle Aged , Peripheral Vascular Diseases/drug therapy , Peripheral Vascular Diseases/economics , Peripheral Vascular Diseases/therapy , Prospective Studies , Young Adult
4.
Diabet Med ; 25(6): 700-7, 2008 Jun.
Article in English | MEDLINE | ID: mdl-18544108

ABSTRACT

AIMS: To determine current management and to identify patient-related factors and barriers that influence management strategies in diabetic foot disease. METHODS: The Eurodiale Study is a prospective cohort study of 1232 consecutive individuals presenting with a new diabetic foot ulcer in 14 centres across Europe. We determined the use of management strategies: referral, use of offloading, vascular imaging and revascularization. RESULTS: Twenty-seven percent of the patients had been treated for > 3 months before referral to a foot clinic. This varied considerably between countries (6-55%). At study entry, 77% of the patients had no or inadequate offloading. During follow-up, casting was used in 35% (0-68%) of the plantar fore- or midfoot ulcers. Predictors of use of casting were male gender, large ulcer size and being employed. Vascular imaging was performed in 56% (14-86%) of patients with severe limb ischaemia; revascularization was performed in 43%. Predictors of use of vascular imaging were the presence of infection and ischaemic rest pain. CONCLUSION: Treatment of many patients is not in line with current guidelines and there are large differences between countries and centres. Our data suggest that current guidelines are too general and that healthcare organizational barriers and personal beliefs result in underuse of recommended therapies. Action should be undertaken to overcome these barriers and to guarantee the delivery of optimal care for the many individuals with diabetic foot disease.


Subject(s)
Delivery of Health Care/standards , Diabetic Foot/therapy , Ambulatory Care/standards , Ambulatory Care/statistics & numerical data , Epidemiologic Methods , Europe , Female , Humans , Ischemia/therapy , Leg/blood supply , Male , Middle Aged , Reperfusion/statistics & numerical data
5.
Diabetes Metab Res Rev ; 24 Suppl 1: S40-4, 2008.
Article in English | MEDLINE | ID: mdl-18442183

ABSTRACT

Loss of pain perception is currently seen as a key factor in the development of diabetic foot ulcers. However, recent studies suggest that nerves play a central role in tissue homeostasis and can orchestrate complex reparative as well as destructive processes in the feet. Evidence is presented that suggests that denervation can result in altered capillary blood flow (in patients with type 2 diabetes), oxygen delivery, fluid filtration, and inflammatory responses. These processes could render the feet of diabetic patients with neuropathy more susceptible to tissue damage, infection and perhaps, in a subset of patients, to the development of acute Charcot neuro-osteoarthropathy (CN).


Subject(s)
Diabetic Neuropathies/physiopathology , Inflammation/physiopathology , Blood Flow Velocity , Diabetic Neuropathies/immunology , Humans , Inflammation/immunology , Microcirculation/physiology
6.
Osteoporos Int ; 19(6): 839-47, 2008 Jun.
Article in English | MEDLINE | ID: mdl-18256778

ABSTRACT

UNLABELLED: To evaluate the incidence of new and/or progressive vertebral deformities and changes in bone mineral density, we re-examined 66 patients with sarcoidosis after a follow-up period of four years. In 17 subjects (26%) new and/or progressive vertebral deformities were found, though BMD did not change significantly. INTRODUCTION: Previous studies from our group have shown that morphometric vertebral deformities suggestive of fractures can be found in 20% of patients with sarcoidosis, despite a normal bone mineral density (BMD). The aim of this study was to determine the incidence of new and/or progressive vertebral deformities and the evolution of BMD during the course of this disease. METHODS: BMD of the hip (DXA) and vertebral fracture assessment (VFA) with lateral single energy densitometry was performed at baseline and after 45 months in 66 patients with sarcoidosis. Potential predictors of new/ progressive vertebral deformities were assessed using logistic regression analysis. RESULTS: The BMD of the total group was unchanged after follow-up. The prevalence of vertebral deformities increased from 20 to 32% (p < 0.05); in 17 subjects (26%) new or progressive vertebral deformities were diagnosed. A lower T-score of the femoral neck [(OR = 2.5 (CI: 1.0-5.9), p < 0.05)] and mother with a hip fracture [(OR = 14.1 (CI: 1.4-142.6), p < 0.05)] were independent predictors of new/progressive deformities. CONCLUSIONS: In subjects with sarcoidosis the number of vertebral deformities increases in the course of this disease, despite unchanged BMD. The combination of low normal BMD and family history of fragility fractures confers an increased risk of the incidence of these deformities.


Subject(s)
Bone Density , Sarcoidosis/complications , Spinal Curvatures/etiology , Absorptiometry, Photon , Adult , Aged , Bone Remodeling , Disease Progression , Female , Femur Neck/physiopathology , Follow-Up Studies , Genetic Predisposition to Disease , Hip Fractures/genetics , Humans , Lumbar Vertebrae/physiopathology , Male , Middle Aged , Risk Factors , Sarcoidosis/physiopathology , Severity of Illness Index , Spinal Curvatures/physiopathology , Spinal Fractures/etiology , Spinal Fractures/physiopathology , Young Adult
7.
Diabetologia ; 51(5): 747-55, 2008 May.
Article in English | MEDLINE | ID: mdl-18297261

ABSTRACT

AIMS/HYPOTHESIS: Outcome data on individuals with diabetic foot ulcers are scarce, especially in those with peripheral arterial disease (PAD). We therefore examined the clinical characteristics that best predict poor outcome in a large population of diabetic foot ulcer patients and examined whether such predictors differ between patients with and without PAD. METHODS: Analyses were conducted within the EURODIALE Study, a prospective cohort study of 1,088 diabetic foot ulcer patients across 14 centres in Europe. Multiple logistic regression modelling was used to identify independent predictors of outcome (i.e. non-healing of the foot ulcer). RESULTS: After 1 year of follow-up, 23% of the patients had not healed. Independent baseline predictors of non-healing in the whole study population were older age, male sex, heart failure, the inability to stand or walk without help, end-stage renal disease, larger ulcer size, peripheral neuropathy and PAD. When analyses were performed according to PAD status, infection emerged as a specific predictor of non-healing in PAD patients only. CONCLUSIONS/INTERPRETATION: Predictors of healing differ between patients with and without PAD, suggesting that diabetic foot ulcers with or without concomitant PAD should be defined as two separate disease states. The observed negative impact of infection on healing that was confined to patients with PAD needs further investigation.


Subject(s)
Diabetic Angiopathies/complications , Diabetic Foot/therapy , Foot Ulcer/therapy , Wound Healing , Age of Onset , Aged , Diabetic Foot/complications , Female , Foot Ulcer/complications , Foot Ulcer/pathology , Humans , Male , Middle Aged , Multivariate Analysis , Predictive Value of Tests , Treatment Outcome
8.
Neth J Med ; 65(10): 386-9, 2007 Nov.
Article in English | MEDLINE | ID: mdl-18057461

ABSTRACT

In this report we present two patients with intracranial multiple midline tumours in the suprasellar region and pineal gland. We postulate that in a patient with multiple midline tumours and normal values of the tumour markers human chorionic gonadotropin and alpha-fetoprotein in serum and cerebrospinal fluid, the only possible diagnosis is a germinoma. In such a situation no histological confirmation is required to start low-dose radiotherapy.


Subject(s)
Brain Neoplasms/diagnosis , Diabetes Insipidus/complications , Germinoma/diagnosis , Adolescent , Adult , Brain Neoplasms/pathology , Brain Neoplasms/radiotherapy , Diabetes Insipidus/pathology , Female , Germinoma/pathology , Germinoma/radiotherapy , Humans , Male , Pineal Gland/pathology
9.
Diabetologia ; 50(1): 18-25, 2007 Jan.
Article in English | MEDLINE | ID: mdl-17093942

ABSTRACT

AIMS/HYPOTHESIS: Large clinical studies describing the typical clinical presentation of diabetic foot ulcers are limited and most studies were performed in single centres with the possibility of selection of specific subgroups. The aim of this study was to investigate the characteristics of diabetic patients with a foot ulcer in 14 European hospitals in ten countries. METHODS: The study population included 1,229 consecutive patients presenting with a new foot ulcer between 1 September 2003 and 1 October 2004. Standardised data on patient characteristics, as well as foot and ulcer characteristics, were obtained. Foot disease was categorised into four stages according to the presence or absence of peripheral arterial disease (PAD) and infection: A: PAD -, infection -; B: PAD -, infection +; C: PAD +, infection -; D: PAD +, infection +. RESULTS: PAD was diagnosed in 49% of the subjects, infection in 58%. The majority of ulcers (52%) were located on the non-plantar surface of the foot. With regard to severity, 24% had stage A, 27% had stage B, 18% had stage C and 31% had stage D foot disease. Patients in the latter group had a distinct profile: they were older, had more non-plantar ulcers, greater tissue loss and more serious comorbidity. CONCLUSIONS/INTERPRETATION: According to our results in this European cohort, the severity of diabetic foot ulcers at presentation is greater than previously reported, as one-third had both PAD and infection. Non-plantar foot ulcers were more common than plantar ulcers, especially in patients with severe disease, and serious comorbidity increased significantly with increasing severity of foot disease. Further research is needed to obtain insight into the clinical outcome of these patients.


Subject(s)
Diabetic Foot/epidemiology , Foot Diseases/epidemiology , Foot Diseases/microbiology , Peripheral Vascular Diseases/epidemiology , Aged , Cohort Studies , Comorbidity , Diabetic Foot/pathology , Europe/epidemiology , Female , Follow-Up Studies , Foot Diseases/pathology , Humans , Male , Middle Aged , Peripheral Vascular Diseases/pathology , Prevalence , Prospective Studies , Severity of Illness Index
10.
Vascul Pharmacol ; 45(5): 281-301, 2006 Nov.
Article in English | MEDLINE | ID: mdl-17010676

ABSTRACT

Ischemic disease represents the new epidemic worldwide. Animal models of ischemic disease are useful because they can help us to understand the underlying pathogenetic mechanisms and develop new therapies. The present review article summarizes the results of a consensus conference on the status and future development of experimentation in the field of cardiovascular medicine using murine models of peripheral and myocardial ischemia. The starting point was to recognize the limits of the approach, which mainly derive from species- and disease-related differences in cardiovascular physiology. For instance, the mouse heart beats at a rate 10 times faster than the human heart. Furthermore, healing processes are more rapid in animals, as they rely on mechanisms that may have lost relevance in man. The main objective of the authors was to propose general guidelines, diagnostic end points and relevance to clinical problems.


Subject(s)
Animal Experimentation , Disease Models, Animal , Extremities/blood supply , Graft Occlusion, Vascular/physiopathology , Ischemia/physiopathology , Myocardial Ischemia/physiopathology , Animal Experimentation/ethics , Animal Experimentation/legislation & jurisprudence , Animals , Atherosclerosis/surgery , Comorbidity , Consensus , Diabetes Mellitus, Type 1/physiopathology , Endpoint Determination , Graft Occlusion, Vascular/therapy , Guidelines as Topic , Humans , Ischemia/therapy , Mice , Myocardial Ischemia/therapy , Regenerative Medicine , Reproducibility of Results , Severity of Illness Index , Species Specificity , Veins/transplantation , Wound Healing
12.
Diabetologia ; 48(9): 1906-10, 2005 Sep.
Article in English | MEDLINE | ID: mdl-15995846

ABSTRACT

AIMS/HYPOTHESIS: The effect of a foot ulcer on health-related quality of life (HRQoL) of patients with diabetes mellitus and their caregivers is unclear, and was therefore evaluated prospectively in this multicentre study. METHODS: HRQoL according to the 36-item health-related quality of life questionnaire (SF-36) of 294 patients (ulcer duration > or = 4 weeks) and 153 caregivers was analysed at baseline (time-point zero [T0]), once the ulcer was healed or after 20 weeks (time-point 1 [T1]), and 3 months later (time-point 2 [T2]). Patients with severe ischaemia were excluded. RESULTS: The mean age of the patients was 60 years, 72% were male, and time since diagnosis of diabetes was 17 years. Patients reported a low HRQoL on all SF-36 subscales. At T1, HRQoL scores in physical and social functioning were higher in patients with a healed vs a non-healed ulcer (p<0.05). At T2, these differences were larger, with higher scores for physical and social functioning, role physical and the physical summary score (all p<0.05). Within-group analysis revealed that HRQoL improved in different subscales in patients with a healed ulcer and worsened in patients with a persistent ulcer from T0 to T2 (all p<0.05). The caregivers of patients with a persisting ulcer had more emotional difficulties at T2. CONCLUSIONS/INTERPRETATION: Diabetic patients with a healed foot ulcer had a higher HRQoL than patients with a persisting ulcer. Healing of a foot ulcer resulted in a marked improvement of several SF-36 subscales 3 months after healing (from T0 to T2). HRQoL declined progressively when the ulcer did not heal. A diabetic foot ulcer appeared to be a large emotional burden on the patients' caregivers, as well.


Subject(s)
Caregivers/psychology , Diabetic Foot/physiopathology , Platelet-Derived Growth Factor/therapeutic use , Quality of Life , Becaplermin , Diabetic Foot/drug therapy , Diabetic Foot/psychology , Diabetic Neuropathies/rehabilitation , Double-Blind Method , Health Status , Humans , Pain , Physical Fitness , Placebos , Proto-Oncogene Proteins c-sis , Recombinant Proteins/therapeutic use , Reproducibility of Results , Social Behavior , Surveys and Questionnaires
13.
Diabetes Metab ; 29(1): 44-52, 2003 Feb.
Article in English | MEDLINE | ID: mdl-12629447

ABSTRACT

AIMS: Hyperglycemia is linked to vascular dysfunction in patients with diabetes mellitus, either directly or through advanced glycation end product (AGE) formation. Experimental evidence has indicated the possible involvement of AGEs in the genesis of vascular complications. We investigated whether serum levels of AGEs and of the glycoxidation compound carboxymethyl-lysine (CML) were increased and correlated with vascular complications in type II diabetes mellitus. METHODS: Serum levels of AGEs and CML-human serum protein (CML-HSP) were measured by a specific immunoassay in 51 men and 26 women aged 58 +/- 6.1 years (mean +/- SD) who had been treated for type II diabetes mellitus for 11 +/- 8 years, and in a non-diabetic control group consisting of 39 men and 21 women aged 55.5 +/- 7.5 years. Patients with macroalbuminuria or abnormal creatinine clearance were excluded from the study. RESULTS: The serum levels of AGEs were significantly increased in patients with type II diabetes compared to controls (P<0.001). Blood levels of CML-HSP were significantly increased in diabetic patients compared to normal subjects [35.3 +/- 27.4 and 9.3 +/- 7.2 (mean +/- SD) pmol/mg of protein, respectively; P<0.0001]. In diabetic patients with retinopathy or microalbuminuria (urinary albumin excretion: UAE > 30 mg/24 h), CML-HSP levels were significantly higher (P<0.02), and even more elevated in patients with both complications. CONCLUSION: In patients with type II diabetes, CML-HSP levels that are at variance with the HbA(1c) index for blood glucose may be a biomarker of glycoxidation, and related to the development of microvascular complications.


Subject(s)
Diabetes Mellitus, Type 2/blood , Diabetic Angiopathies/diagnosis , Glycation End Products, Advanced/blood , Lysine/analogs & derivatives , Lysine/blood , Microcirculation/physiology , Biomarkers/blood , Blood Glucose/metabolism , Body Mass Index , Diabetic Angiopathies/blood , Female , Humans , Male , Middle Aged
14.
Ned Tijdschr Geneeskd ; 145(16): 761-5, 2001 Apr 21.
Article in Dutch | MEDLINE | ID: mdl-11346911

ABSTRACT

Three patients with diabetes mellitus (type 2) and cardiovascular disease had disturbed lipid concentrations: two women aged 60 and 73 years and one man aged 47 years. The lipid levels were normalised during the 9-18 years of treatment with medication and in this period the patients experienced no cardiovascular events. Disturbances in plasma lipid levels play a major role in the increased risk of cardiovascular disease in patients with diabetes mellitus (type 2). Cholesterol-lowering treatment should be aggressive and based on the lipid profile. Statins reduce cardiovascular events by lowering the concentration of both the total cholesterol and low-density lipoprotein cholesterol whereas fibrates reduce cardiovascular events by increasing high-density lipoprotein cholesterol concentrations and lowering triglyceride concentrations.


Subject(s)
Cardiovascular Diseases/prevention & control , Cholesterol/blood , Diabetes Mellitus, Type 2/complications , Hyperlipidemias/complications , Hyperlipidemias/diagnosis , Hypolipidemic Agents/therapeutic use , Aged , Cardiovascular Diseases/etiology , Cholesterol, HDL/blood , Cholesterol, LDL/blood , Diabetes Mellitus, Type 2/blood , Diagnosis, Differential , Female , Humans , Hyperlipidemias/blood , Hyperlipidemias/drug therapy , Hypolipidemic Agents/pharmacology , Male , Middle Aged , Randomized Controlled Trials as Topic , Treatment Outcome , Triglycerides/blood
15.
Expert Opin Pharmacother ; 2(3): 467-78, 2001 Mar.
Article in English | MEDLINE | ID: mdl-11336599

ABSTRACT

Type 2 diabetes mellitus is characterised by impaired insulin secretion, diminished peripheral insulin action and increased hepatic glucose production. Clinical trials have indicated that near-normal glucose control may reduce the risk for microvascular and - to a lesser extent - macrovascular complications in Type 2 diabetic patients. Thiazolidinediones improve insulin action by activating a nuclear receptor, PPARgamma. Therefore, these drugs are often referred to as 'insulin sensitisers'. Rosiglitazone is the second compound of this group. Clinical studies with rosiglitazone have shown that it is effective in lowering blood glucose levels in Type 2 diabetic patients treated with either diet alone, sulphonylurea or metformin. Preliminary studies suggest that rosiglitazone also improves glycaemic control in insulin-treated patients while even slightly decreasing insulin dose. The magnitude of the effects is, however, moderate. In diet-treated patients, the reduction of HbA1c levels amounted on average 0.5 - 1.5% and addition to existing sulphonylurea therapy decreased HbA1c by 1.0 - 1.2%. The clinical relevance of additional beneficial effects, i.e., on blood pressure and microalbuminuria, needs to be determined further. Rosiglitazone does not cause hypoglycaemia or gastrointestinal side effects. There is however some concern related to fluid retention, which seems to be an effect of all PPARgamma agonists. In patients treated with rosiglitazone, no severe hepatotoxic side effects have been noticed until now. In the treatment of our patients with Type 2 diabetes, drugs like rosiglitazone which directly reduce insulin resistance are very welcome but more data on its combined use with insulin are needed. Additional studies will also explore its long-term effects in sparing beta-cell function and reducing diabetes-related complications and atherosclerosis.


Subject(s)
Diabetes Mellitus, Type 2/drug therapy , Hypoglycemic Agents/therapeutic use , Thiazoles/therapeutic use , Thiazolidinediones , Animals , Blood Pressure/drug effects , Cholesterol, LDL/blood , Drug Interactions , Drug Therapy, Combination , Humans , Insulin/therapeutic use , Islets of Langerhans/drug effects , Islets of Langerhans/physiology , Metformin/therapeutic use , Rosiglitazone
16.
Circulation ; 102(21): 2650-8, 2000 Nov 21.
Article in English | MEDLINE | ID: mdl-11085970

ABSTRACT

BACKGROUND: Anisotropy creates nonuniformity in electrical propagation and may contribute to the occurrence of unidirectional conduction block and reentry. We describe the characteristics of reentrant tachycardia in a 2D layer of anisotropic ventricular myocardium. METHODS AND RESULTS: A Langendorff-perfused epicardial sheet (1.0+/-0.4 mm, n=35) was created by freezing the intramural layers of the rabbit left ventricle. Epicardial activation maps were constructed by use of different high-resolution mapping arrays connected to a mapping system. In 5 experiments, monophasic action potentials were recorded. In the intact left ventricle, no arrhythmias except VF could be induced. After freezing, programmed electrical stimulation or rapid pacing led to the induction of sustained VT (cycle length 130+/-11 ms). VT was caused by reentry around a functional line of block oriented parallel to the epicardial fiber direction. Action potential recordings demonstrated that the central line of block was kept refractory by electrotonic currents generated by the depolarization waves propagating at either side of the line of block. At the pivot points of the line of block, the pronounced curvature of the turning wave and abrupt loading changes created an excitable gap of 30 ms in the reentrant pathway. CONCLUSIONS: In uniform anisotropic myocardium, reentry around a functional Z-shaped line of block may occur. The core of the circuit is kept refractory by electrotonic currents. The pronounced wave-front curvature and abrupt loading changes at the pivot points cause local conduction delay and create a small excitable gap.


Subject(s)
Heart Conduction System/physiopathology , Heart Ventricles/physiopathology , Myocardium/metabolism , Tachycardia, Ventricular/physiopathology , Action Potentials/physiology , Animals , Anisotropy , Cardiac Pacing, Artificial , Electric Stimulation , Electrophysiologic Techniques, Cardiac , Heart Conduction System/metabolism , Heart Ventricles/metabolism , In Vitro Techniques , Rabbits , Reaction Time/physiology , Signal Processing, Computer-Assisted , Tachycardia, Ventricular/etiology , Tachycardia, Ventricular/metabolism
17.
Diabetes Metab Res Rev ; 16 Suppl 1: S11-5, 2000.
Article in English | MEDLINE | ID: mdl-11054881

ABSTRACT

Patients with Type 2 diabetes mellitus frequently have peripheral vascular disease, with a predilection for the lower legs. In this review potential mechanisms for this high prevalence and altered distribution are explored. It is hypothesised that the metabolic abnormalities in the prediabetic phase predispose to a more distal and aggressive atherosclerosis. Once diabetes has developed this process is accelerated due to chronic hyperglycaemia. Furthermore, endothelial damage, non-enzymatic glycosylation and polyneuropathy could lead to impaired vascular remodelling and collateral formation.


Subject(s)
Diabetes Mellitus, Type 2/physiopathology , Diabetic Angiopathies/physiopathology , Peripheral Vascular Diseases/physiopathology , Diabetic Neuropathies/physiopathology , Humans , Hyperglycemia/physiopathology , Inflammation/physiopathology , Insulin Resistance
18.
Expert Opin Pharmacother ; 1(1): 149-56, 1999 Nov.
Article in English | MEDLINE | ID: mdl-11249557

ABSTRACT

Miglitol (Bay m 1099, Bayer) is a second generation alpha-glucosidase inhibitor. It is a derivative of 1-desoxynojirimycin, and binds reversibly to the brushborder alpha-glucosidase enzymes. In contrast to its parent drug (acarbose, Bay g 5421, Bayer), miglitol is almost completely absorbed in the small intestine. It has to be taken with each main meal, and through its effect on carbohydrate digestion it blunts the postprandial blood glucose increase. Miglitol has no or a very small effect on fasting blood glucose levels. The blood-glucose lowering effects of miglitol in patients with Type 2 diabetes are lower than those of the frequently-used sulphonylurea compounds. Long-term studies show that a moderate average reduction of HbA1c of 0.3-0.7% point from baseline can be achieved. An advantage over sulphonylurea is the effect on serum insulin levels: miglitol therapy leads to slightly lower postprandial levels of serum insulin, whereas chronic sulphonylurea treatment usually increases serum insulin levels. This insulin-sparing effect may, in theory, lead to a lesser weight gain or even no weight gain and reduced risk of hypoglycaemia during chronic treatment. Long-term experience in Type 1 diabetic patients is limited. Similarly, miglitol may lead to reduced postprandial glucose excursions, slightly reduced insulin requirements and perhaps, as a consequence, a lower risk of hypoglycaemia. More long-term data are needed to fully assess to the clinical use of miglitol in these patients.


Subject(s)
Diabetes Mellitus/drug therapy , Enzyme Inhibitors/therapeutic use , Glucosamine/analogs & derivatives , Glucosamine/therapeutic use , Glycoside Hydrolase Inhibitors , Hypoglycemic Agents/therapeutic use , 1-Deoxynojirimycin/analogs & derivatives , Animals , Clinical Trials as Topic , Diabetes Mellitus/enzymology , Enzyme Inhibitors/adverse effects , Enzyme Inhibitors/pharmacokinetics , Enzyme Inhibitors/pharmacology , Glucosamine/administration & dosage , Glucosamine/pharmacokinetics , Glucosamine/pharmacology , Humans , Hypoglycemic Agents/adverse effects , Hypoglycemic Agents/pharmacokinetics , Hypoglycemic Agents/pharmacology , Imino Pyranoses
19.
Proc Natl Acad Sci U S A ; 95(8): 4630-4, 1998 Apr 14.
Article in English | MEDLINE | ID: mdl-9539789

ABSTRACT

Glucose and other reducing sugars react with proteins by a nonenzymatic, posttranslational modification process called nonenzymatic glycation. The formation of advanced glycation end products (AGEs) on connective tissue and matrix components accounts largely for the increase in collagen crosslinking that accompanies normal aging and which occurs at an accelerated rate in diabetes, leading to an increase in arterial stiffness. A new class of AGE crosslink "breakers" reacts with and cleaves these covalent, AGE-derived protein crosslinks. Treatment of rats with streptozotocin-induced diabetes with the AGE-breaker ALT-711 for 1-3 weeks reversed the diabetes-induced increase of large artery stiffness as measured by systemic arterial compliance, aortic impedance, and carotid artery compliance and distensibility. These findings will have considerable implications for the treatment of patients with diabetes-related complications and aging.


Subject(s)
Carotid Artery, Common/physiopathology , Collagen/metabolism , Diabetes Mellitus, Experimental/physiopathology , Glycation End Products, Advanced/metabolism , Hemodynamics/drug effects , Thiazoles/pharmacology , Animals , Blood Flow Velocity , Blood Pressure , Cardiac Output , Carotid Artery, Common/drug effects , Carotid Artery, Common/physiology , Cross-Linking Reagents , Diabetes Mellitus, Experimental/blood , Heart Rate , In Vitro Techniques , Male , Muscle, Smooth, Vascular/drug effects , Muscle, Smooth, Vascular/physiology , Muscle, Smooth, Vascular/physiopathology , Rats , Rats, Wistar
20.
Diabetologia ; 37(1): 10-4, 1994 Jan.
Article in English | MEDLINE | ID: mdl-8150221

ABSTRACT

Advanced glycation end-product-formation is thought to play a role in the development of diabetic angiopathy. By altering the structure of different extracellular matrix components advanced glycation end-products might affect vascular and glomerular permeability. In this study we investigated the effect of treatment with an inhibitor of advanced glycation end-product-formation, aminoguanidine, on vascular permeability and the development of albuminuria in streptozotocin-induced diabetic rats. Male Wistar Rp rats were randomized into a control group, a diabetic group, and an aminoguanidine-treated diabetic group. After 8 weeks, 24-h urine collections were taken and rats were implanted with an arterial and a venous catheter. mean arterial blood pressure was determined by intra-arterial measurement. Regional albumin clearances were assessed in the eye, ileum, lung, skeletal muscle and skin using an isotope technique. Mean arterial pressure in the diabetic group was significantly lower in the control and aminoguanidine-treated groups (p < 0.02). Regional albumin clearances were significantly increased in all tissues of diabetic rats compared to control rats (p < 0.05). Aminoguanidine treatment of diabetic rats resulted in a significant decrease of regional albumin clearance in all tissues except the lung (p < 0.05, lung p = 0.07). The development of albuminuria in diabetic rats however, was not affected by aminoguanidine.


Subject(s)
Albuminuria , Diabetes Mellitus, Experimental/metabolism , Guanidines/pharmacology , Serum Albumin/pharmacokinetics , Analysis of Variance , Animals , Blood Pressure/drug effects , Diabetes Mellitus, Experimental/physiopathology , Diabetes Mellitus, Experimental/urine , Eye/drug effects , Eye/metabolism , Glycation End Products, Advanced/antagonists & inhibitors , Humans , Ileum/drug effects , Ileum/metabolism , Male , Muscles/drug effects , Muscles/metabolism , Random Allocation , Rats , Rats, Wistar , Reference Values , Skin/drug effects , Skin/metabolism , Tissue Distribution
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