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The fabrication of electrospun magnetoactivefibrous nanocompositemembranes based on the water-soluble and biocompatible poly(ethyleneoxide) (PEO), the biocompatible and biodegradable poly(l-lactide)(PLLA) and preformed oleic acid-coated magnetite nanoparticles (OA.Fe3O4) is reported. Visualization of the membranesby electron microscopy techniques reveals the presence of continuousfibers of approximately 2 μm in diameter, with the magneticnanoparticles being evenly distributed within the fibers, retainingat the same time their nanosized diameters (∼5 nm). Thermalgravimetric analysis measurements suggest that the magnetic nanoparticlesembedded within the polymer fibers affect favorably the thermal stabilityof the membranes. Moreover, assessment of their magnetic characteristicsby vibrating sample magnetometry discloses tunable superparamagneticbehavior at ambient temperature. For the first time, the biocompatibilityand biodegradability of PEO/PLLA and the tunable magnetic activityof the OA.Fe3O4are combined in the same drugdelivery system, with N-acetyl-p-aminophenol (acetaminophen) as a proof-of-concept pharmaceutical.Furthermore, their heating ability under alternating current (AC)magnetic field conditions is evaluated using frequency of 110 kHzand corresponding magnetic field strength of 25 mT (19.9 kA/m). Consequently,these magnetoactive fibrous nanocomposites exhibit promising characteristicsfor future exploitation in magnetothermally triggered drug delivery. [ABSTRACT FROM AUTHOR]

Cytokines are known to play an important role in autoimmunity and have been suggested to be involved in the pathogenesis of insulin-dependent diabetes (IDDM), In the present study we have measured IL-1, IL-2, IL-4, IL-6, interferon-gamma (IFN-γ) and tumour necrosis factor (TNF) (using both immunoassays and bioassays) in sera from 50 patients affected by IDDM at the time of clinical diagnosis and 51 age and sex matched controls. Detectable levels of IL-1, IL-2, IL-6 and IFN-γ were found in the serum of a small percentage of subjects and were not significantly different between patients and controls, IL-4 was detectable in a higher number of both patients and controls and circulating TNF-α (> 1 U/ml) was found in a percentage of patients (24%) significantly higher than controls (P<0.01), Raised levels of TNF-α were detectable using an immunoenzymatic assay whereas TNF bioactivity in these samples was negligible. We conclude that the presence of immunoreactive TNF-α in the patient's sera may reflect an increased localized production of this cytokine at pancreatic level. However, the measurement in serum of other cytokines does not add information on the role that they may play in the pathogenesis of IDDM. [ABSTRACT FROM AUTHOR]

The possible correlation between soluble immune factors and platelet and coagulation factors has been evaluated in Type 1 diabetic patients with and without proliferative retinopathy, and in non-diabetic controls. Soluble immune complexes, platelet factor IV (PF4), β -thromboglobulin, fibrinogen, factor VIII related antigen and anti-thrombin III were significantly increased in Type I diabetic patients with retinopathy as compared to non-diabetic controls. Fibrinogen and anti-thrombin HI were also higher in those patients with retinopathy compared to those without retinopathy. A significant correlation was found between positive values of soluble immune complexes and increased levels of PF4 and β-thromboglobulin in diabetic patients with retinopathy. The presence of soluble immune complexes and insulin-anti-insulin complexes was associated with a significantly greater number of elevated haemostatic factors in retinopathic patients. Our findings suggest that the interaction of platelets and soluble immune complexes or insulin-anti-insulin complexes may be pathologically relevant to the development of diabetic retinopathy. [ABSTRACT FROM AUTHOR]

Viral infection has been suggested to play a triggering role in the pancreatic beta cell destruction which occurs in insulin-dependent diabetes (IDDM). However, the underlying mechanism of this phenomenon is unknown. In this study a human insulinoma cell line has been infected with measles, mumps and rubella viruses since a temporal association is reported between the clinical onset of IDDM and diseases caused by these viruses. The infection with measles and mumps viruses induced the release of interleukin-1 (IL-1) and interleukin-6 (IL-6) by the cell line as assessed by a bioassay and up-regulated the expression of human leucocyte antigen (HLA) class I and class II antigens as evaluated by cytofluorimetric analysis. Stimulation with rubella virus induced the release of IL-6 only and had no effect on HLA antigen expression. These data show for the first time that IL-1 and IL-6 secretion by an insulinoma cell line may occur after viral infection and suggest that cytokine release and increased expression of HLA molecules by beta cells may act to induce the immune response towards beta cells in IDDM. [ABSTRACT FROM AUTHOR]

Lymphocytes bearing surface antigens indicating early and full activation have been evaluated, in addition to T cell subsets, in blood samples from diabetic pregnant patients, neonates from diabetic mothers and control groups. The type of diabetes and the trimester of pregnancy were taken into account. Monoclonal antibodies were used to enumerate total T cells, helper/inducer, cytotoxic/suppressor T lymphocytes and activated mononuclear cells using antibodies binding lymphocyte surface antigens as markers of early lymphocyte activation, and MHC Class II surface antigens as markers of late activation. A decrease in T-helper cells during the third trimester of pregnancy in Type 1 (insulin-dependent) and gestational diabetic patiens ( p<0.02) and a decrease in T-suppressor cells in Type 2 (non-insulin-dependent) diabetic pregnant patients during the third trimester ( p<0.01) were observed in relation to normal values. As in normal pregnancy, 4F2-positive cells were increased in 48% of diabetic pregnant patients during the second and third trimesters of gestation. Class II-positive cells were increased in almost 60% of Type 1 and gestational diabetic patients during the last trimester of pregnancy in comparison with normal pregnant women and control subjects. A decrease in T-helper cells ( p<0.02) and a clear increase in 4F2-positive cells ( p<0.001) and Class II-positive lymphocytes ( p<0.005) were observed in the infants of diabetic mothers in comparison with control subjects. The maternal cellular immune system, actively alerted in pregnancy, is fully activated in a number of Type 1 and gestational diabetic pregnant patients. Activated lymphocytes are even found in the neonates of diabetic mothers, but these do not trigger the events leading to the onset of diabetes in the short term. [ABSTRACT FROM AUTHOR]