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Query: UMLS:C0011849 (diabetes)
 277,896 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

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 1 diabetes was found to be significantly increased compared to controls (19.2 +/- 3.9% vs. 14.9 +/- 3.5%). This difference of monocyte binding remained unchanged if the endothelial cells were stimulated with 27.7 mmol/l glucose for seven days prior to adhesion studies (31.5 +/- 4.9% in diabetes patients vs. 25.8 +/- 4.1% in controls) whereby monocyte binding markedly increased under these hyperglycemic conditions. Furthermore, an increased CD11b expression could be demonstrated on monocytes of normolipidemic hyperglycemic type 1 diabetes patients. Thus, we suggest that hyperglycemia per se may contribute to increased monocyte binding to endothelial cells by promoting leucocyte integrin expression. Recently performed studies of our group strengthen the hypothesis that this monocyte activation is mediated by stimulation of the beta-isoform of proteinkinase C.
Exp Clin Endocrinol Diabetes 1999
PMID:Binding of monocytes from normolipidemic hyperglycemic patients with type 1 diabetes to endothelial cells is increased in vitro. 1043 64

White blood cells have a potential role in the pathogenesis of vasculopathy in diabetic patients. We studied the circulating peripheral blood in a cohort of patients with documented ischemic heart or brain disease with and without type 2 diabetes by means of image analysis and flow cytometry. Our study showed that the state of leukocyte adhesiveness/aggregation is slightly increased in those who had concomitant diabetes but that there was no difference regarding the expression of CD11b/CD18 and CD62L antigens on the surface of the peripheral blood white blood cells. The finding of a significantly increased number of white blood cells in the peripheral blood of patients with ischemic vascular diseases is important insofar as it is associated with a poorer prognosis.
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PMID:The state of leukocyte adhesiveness/aggregation in the peripheral blood of patients with type 2 diabetes and ischemic vascular disease. 1148 76

Microalbuminuria in Type I diabetes involves a cell membrane abnormality and is associated with a large increase in cardiovascular risk. The hypothesis that the membrane abnormality alters granule exocytosis in neutrophils, which could contribute to the increased incidence of cardiovascular disease, was investigated. PMA-stimulated expression of CD11b and CD69 on neutrophils from normal controls (NC), long-term uncomplicated Type I diabetic control patients (DC) and diabetic nephropathy patients (DN) was determined by fluorescence activated cell scanning. Neutrophils from DN were faster than neutrophils from either NC or DC to exocytose primary granules with CD69 following initial expression of the adhesion molecule CD11b. However, a larger proportion of neutrophils from DN failed to withdraw CD11b from the cell membrane after 90 min incubation. The protein kinase C (PKC) inhibitor, bisindolylmaleimide (BIM), showed that a larger proportion of neutrophils from DN, compared with DC or NC, exocytosed primary granules independent of PKC. The calpain inhibitor, E64d, showed that a larger proportion of neutrophils from both groups of diabetic patients, compared with NC, exocytosed primary granules independent of calpain. Cytoskeletal disruption with cytochalasin D had an effect on CD11b and CD69 exocytosis similar to that of BIM and E64d. The pathways controlling granule exocytosis in neutrophils from diabetic patients are abnormal. A change characteristic of DN causes rapid exocytosis of primary granules, and also causes the adhesion molecule CD11b to persist on an increased proportion of neutrophils. This will make an important contribution to increased vascular damage in these patients.
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PMID:Abnormalities in primary granule exocytosis in neutrophils from Type I diabetic patients with nephropathy. 1174 62

Leukocyte adhesion to the diabetic retinal vasculature results in blood-retinal barrier breakdown, capillary nonperfusion, and endothelial cell injury and death. Intercellular adhesion molecule-1 (ICAM-1) and the leukocyte integrin CD18 are required for these processes. Diabetes was induced in Long Evans rats, resulting in a two- to threefold increase in retinal leukocyte adhesion. Following one week of diabetes, neutrophil CD11a, CD11b, and CD18 expression was increased significantly, as were retinal ICAM-1 levels. Animals were treated with aspirin, a cyclooxygenase 2 (COX-2) inhibitor (meloxicam), or a soluble tumor necrosis factor alpha (TNF-alpha) receptor/Fc construct (TNFR-Fc, etanercept). High-dose aspirin, etanercept, and high-dose meloxicam each reduced leukocyte adhesion and suppressed blood-retinal barrier breakdown. High-dose aspirin also reduced the expression of CD11a, CD11b, and CD18, whereas meloxicam and etanercept did not. High-dose aspirin, etanercept, and high-dose meloxicam each reduced retinal ICAM-1 expression. Aspirin and meloxicam both lowered retinal TNF-alpha levels. Notably, aspirin, meloxicam, and etanercept did not change retinal vascular endothelial growth factor levels. High-dose aspirin, etanercept and high-dose meloxicam, each suppressed the retinal expression of eNOS and the DNA-binding capacity of retinal nuclear factor-kappaB. High-dose aspirin also suppressed Erk kinase activity, which is involved in CD18 up-regulation. Taken together, these data identify COX-2 and TNF-alpha as operative in the early signature pathologies of diabetic retinopathy, a newly recognized inflammatory disease.
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PMID:Nonsteroidal anti-inflammatory drugs prevent early diabetic retinopathy via TNF-alpha suppression. 1182 Dec 58

Leukocyte adhesion to the diabetic retinal vasculature results in early blood-retinal barrier breakdown, capillary nonperfusion, and endothelial cell injury and death. Previous work has shown that intercellular adhesion molecule-1 (ICAM-1) and CD18 are required for these processes. However the relevant in vivo stimuli for ICAM-1 and CD18 expression in diabetes remain unknown. The current study investigated the causal role of endogenous vascular endothelial growth factor (VEGF) and nitric oxide in initiating these events. Diabetes was induced in Long-Evans rats with streptozotocin, resulting in a two- to threefold increase in retinal leukocyte adhesion. Confirmed diabetic animals were treated with a highly specific VEGF-neutralizing Flt-Fc construct (VEGF TrapA(40)). Retinal ICAM-1 mRNA levels in VEGF TrapA(40)-treated diabetic animals were reduced by 83.5% compared to diabetic controls (n = 5, P < 0.0001). VEGF TrapA(40) also potently suppressed diabetic leukocyte adhesion in retinal arterioles (47%, n = 11, P < 0.0001), venules (36%, n = 11, P < 0.0005), and capillaries (36%, n = 11, P < 0.001). The expression of endothelial nitric oxide synthase (eNOS), a downstream mediator of VEGF activity, was increased in diabetic retina, and was potently suppressed with VEGF TrapA(40) treatment (n = 8, P < 0.005). Further, VEGF TrapA(40) reduced the diabetes-related nitric oxide increases in the retinae of diabetic animals. The inhibition of eNOS with N-omega-nitro-L-arginine methyl ester also potently reduced retinal leukocyte adhesion. Although neutrophil CD11a, CD11b, and CD18 levels were increased in 1-week diabetic animals, VEGF TrapA(40) did not alter the expression of these integrin adhesion molecules. Taken together, these data demonstrate that VEGF induces retinal ICAM-1 and eNOS expression and initiates early diabetic retinal leukocyte adhesion in vivo. The inhibition of VEGF bioactivity may prove useful in the treatment of the early diabetic retinopathy.
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PMID:Retinal vascular endothelial growth factor induces intercellular adhesion molecule-1 and endothelial nitric oxide synthase expression and initiates early diabetic retinal leukocyte adhesion in vivo. 1183 70

Aberrant dendritic cell (DC) development and function may contribute to autoimmune disease susceptibility. To address this hypothesis at the level of myeloid lineage-derived DC we compared the development of DC from bone marrow progenitors in vitro and DC populations in vivo in autoimmune diabetes-prone nonobese diabetic (NOD) mice, recombinant congenic nonobese diabetes-resistant (NOR) mice, and unrelated BALB/c and C57BL/6 (BL/6) mice. In GM-CSF/IL-4-supplemented bone marrow cultures, DC developed in significantly greater numbers from NOD than from NOR, BALB/c, and BL/6 mice. Likewise, DC developed in greater numbers from sorted (lineage(-)IL-7Ralpha(-)SCA-1(-)c-kit(+)) NOD myeloid progenitors in either GM-CSF/IL-4 or GM-CSF/stem cell factor (SCF)/TNF-alpha. [(3)H]TdR incorporation indicated that the increased generation of NOD DC was due to higher levels of myeloid progenitor proliferation. Generation of DC with the early-acting hematopoietic growth factor, flt3 ligand, revealed that while the increased DC-generative capacity of myeloid-committed progenitors was restricted to NOD cells, early lineage-uncommitted progenitors from both NOD and NOR had increased DC-generative capacity relative to BALB/c and BL/6. Consistent with these findings, NOD and NOR mice had increased numbers of DC in blood and thymus and NOD had an increased proportion of the putative myeloid DC (CD11c(+)CD11b(+)) subset within spleen. These findings demonstrate that diabetes-prone NOD mice exhibit a myeloid lineage-specific increase in DC generative capacity relative to diabetes-resistant recombinant congenic NOR mice. We propose that an imbalance favoring development of DC from myeloid-committed progenitors predisposes to autoimmune disease in NOD mice.
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PMID:Increased generation of dendritic cells from myeloid progenitors in autoimmune-prone nonobese diabetic mice. 1199 55

A thrombotic/inflammatory reaction is elicited when isolated islets of Langerhans come in contact with ABO-compatible blood. The detrimental effects of this instant blood-mediated inflammatory reaction (IBMIR) provide a reasonable explanation for the observation that an unexpectedly high number of islets, from several donors, are needed to produce normoglycemia in transplant patients with type 1 diabetes. In this study, the hypothesis that a specific thrombin inhibitor, Melagatran, could reduce IBMIR in an in vitro model in which human islets are exposed to ABO-compatible blood was tested. The administration of Melagatran abrogated IBMIR dose-dependently. Islets exposed to blood, in the absence or presence of 0.4 micromol/l Melagatran, exhibited a loss of integrity and were found to be trapped in macroscopic clots containing platelets and CD11b(+) leukocytes. At concentrations from 1 to 10 micromol/l, Melagatran inhibited both coagulation and complement activation. Also, platelet and leukocyte activation and consumption were decreased. Islet morphology was maintained with almost no platelets adhering to the surface, and infiltration by CD11b(+) leukocytes was considerably reduced. In conclusion, Melagatran significantly reduced IBMIR in this model system. This protective effect indicates that thrombin plays a pivotal role in IBMIR and suggests that thrombin inhibition can improve the outcome of clinical islet transplantation.
Diabetes 2002 Jun
PMID:Inhibition of thrombin abrogates the instant blood-mediated inflammatory reaction triggered by isolated human islets: possible application of the thrombin inhibitor melagatran in clinical islet transplantation. 1203 65

Diabetes mellitus (DM) is associated with platelet and leukocyte dysfunction. Previous observations with regard to insulin effects on platelet and leukocyte function are less than consistent. We thus investigated the effects of insulin on platelets and leukocytes, as well as on platelet-leukocyte interactions in whole blood. Hirudinized whole blood from 20 healthy subjects was preincubated at 37 degrees C in the absence or presence of insulin (30 and 300 microU/ml), and further incubated without or with adenosine diphosphate (ADP) (10(-5) M) or N-formyl-methionyl-leucyl-phenylalanine (fMLP) (10(-7) M), respectively. Platelet P-selectin expression, platelet fibrinogen binding, single platelet and platelet-platelet aggregate (PPA) counts, and leukocyte CD11b expression and superoxide anion production were monitored by flow cytometry. Insulin decreased single platelet counts (P<0.05) and increased PPAs (P<0.01) at 300 microU/ml in unstimulated samples, but did not significantly influence the P-selectin expression or fibrinogen binding of single platelets. Insulin also enhanced ADP-induced platelet aggregation, seen as an augmented decrease of single platelet counts. Insulin (30 microU/ml) increased leukocyte CD11b mean fluorescence intensity (MFI) in unstimulated, as well as fMLP- and ADP-stimulated samples (P<0.05 for all). fMLP-induced superoxide anion (O(2)(-)) production was, however, attenuated by insulin. Furthermore, fMLP-activation of leukocytes was associated with enhanced platelet fibrinogen binding and P-selectin expression. In conclusion, clinically relevant concentrations of insulin enhance platelet aggregability and leukocyte CD11b expression, but attenuate leukocyte respiratory burst activity. Our results suggest that insulin may modulate thrombotic and inflammatory processes in vivo in a complex manner.
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PMID:Effects of insulin on platelet and leukocyte activity in whole blood. 1247 80

In vascular atherosclerotic disease and in diabetes mellitus few studies have evaluated the polymorphonuclear leukocyte (PMN) adhesion molecule pattern. In this study we examined the PMN integrin expression at baseline and after activation in controls and type 2 diabetic subjects with macrovascular complications (MVC). We enrolled 21 subjects with type 2 diabetes mellitus and macrovascular complications, localized in peripheral, coronary and cerebral sites. The patients had peripheral occlusive arterial disease, chronic cerebrovascular disease or coronary heart disease. We evaluated the expression of some PMN integrins (CD11a, CD11b, CD11c, CD18), using flow cytofluorimetry, at baseline and after in vitro activation with 4-phorbol-12-myristate-13 acetate. Type 2 diabetic subjects with MVC showed, compared to normals, an increase of CD11a and CD18 and a decrease of CD11b and CD11c. After activation, in PMN(s) of normal subjects, we found an increase in the expression of all adhesion molecules, while in PMNS of type 2 diabetic subjects with MVC we observed an increase of CD11b and CD11c and a decrease of CD11a. In type 2 diabetic patients with MVC the basal upregulation of CD11a and CD18 may be related to the PMN spontaneous activation, while the behavior of CD11b may depend on its self-consumption. After activation the CD11a modification may be due to its cleavage or to an altered integrin phosphorylation/dephosphorylation balance.
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PMID:Polymorphonuclear leukocyte integrin pattern, at baseline and after activation, in type 2 diabetic subjects with macrovascular complications. 1268 24

Islet transplantation is now established as an optional treatment for type I diabetes. However, rates of insulin independence in islet transplant recipients are still low. Although the major source of allograft is derived from brain-dead patient, the nonphysiologic state of brain death (BD) deteriorates organs such as liver and kidney. To determine the effects of BD on islets, a rodent model of BD has been used. Histologically, islets of BD rats showed decreased permeability and impaired integrity of the cell membranes. Flow cytometric analysis showed that CD11b/c-positive cells within islets were slightly increased in BD. This result suggests that BD induces macrophage infiltration into the islets. Moreover, RT-PCR revealed significant augmentation of macrophages-associated inflammatory molecules (IL-1beta, IL-6, TNF-alpha, and MCP-1) in islets from a BD donor. Inducible nitric oxide synthase (iNOS) was weakly expressed, although not reaching statistical significance compared with control. Our results indicate that islets from a BD donor are immunologically activated and have a potential risk factor for early graft loss and a poor long-term function of grafts in clinical setting of islet transplantation. Immunomodulation, to eliminate intraislet immunocytes and/or activated macro phage-associated molecules, might be necessary for the better outcome after islet graft from BD donors.
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PMID:Activation of macrophage-associated molecules after brain death in islets. 1269 61


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