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| 2. |
- Eriksson, Jan W, et al.
(författare)
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Vanadate increases cell surface insulin binding and improves insulin sensitivity in both normal and insulin-resistant rat adipocytes
- 1992
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Ingår i: Diabetologia. - 0012-186X .- 1432-0428. ; 35:6, s. 510-516
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to elucidate the acute effects of vanadate on cell surface insulin binding and insulin sensitivity in rat adipocytes. The cells were preincubated at 37 degrees for 20 min followed by energy depletion with potassium cyanide, extensive washing and 125I-insulin binding. The presence of vanadate or insulin during the preincubation period dose-dependently enhanced 125I-insulin binding to normal adipocytes (maximally 4-5-fold) through an increased number of binding sites without any change in receptor affinity. Submaximal concentrations of vanadate added together with insulin enhanced the cellular sensitivity to the effect of insulin to stimulate 3-O-methylglucose transport. Vanadate, but not insulin, was also capable of increasing insulin binding as well as insulin sensitivity in insulin-resistant cells (treatment with N6-monobutyryl cAMP or amiloride and adipocytes from obese, aging rats). There was a correlation between the effect of vanadate to augment insulin binding and its ability to enhance cellular insulin sensitivity. Thus, the data suggest that short-term vanadate treatment improves insulin sensitivity through enhanced receptor binding and that this occurs in both normal and insulin-resistant cells.
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| 3. |
- Lönnroth, P, et al.
(författare)
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Peroxovanadate but not vanadate exerts insulin-like effects in human adipocytes
- 1993
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Ingår i: Diabetologia. - 0012-186X .- 1432-0428. ; 36:2, s. 113-116
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Tidskriftsartikel (refereegranskat)abstract
- Vanadate and peroxovanadate were recently reported to exert maximal or even supramaximal (peroxovanadate) insulin-like effects in rat adipocytes. To evaluate the response in human cells, isolated human adipocytes were exposed to insulin or various concentrations of vanadate (0-10 mmol/l) or peroxovanadate (0-5 mmol/l). Neither vanadate nor peroxovanadate affected 125I-insulin binding and insulin sensitivity. Vanadate exerted no apparent effect on 14C-U-glucose uptake, whereas 0.1 mmol/l peroxovanadate exerted a full insulin-like response (p < 0.001). No additive response was observed by combining either vanadate or peroxovanadate with insulin. Peroxovanadate at 0.1 mmol/l was as effective as insulin in inhibiting isoproterenol-stimulated lipolysis. Neither peroxovanadate nor insulin-inhibited lipolysis stimulated by N6-monobutyryl-cAMP, an analogue which is not hydrolysed by the cAMP-phosphodiesterase. It is concluded that peroxovanadate, but not vanadate, elicits a full insulin-like response in human adipocytes.
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| 4. |
- Tallroth, G., et al.
(författare)
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Neurophysiological changes during hypoglycaemia in type 1 (insulin- dependent) diabetes mellitus and in normal man
- 1990
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Ingår i: Diabetologia. - 0012-186X .- 1432-0428. ; 33:5, s. 319-323
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Tidskriftsartikel (refereegranskat)abstract
- Hypoglycaemia (median venous blood glucose 1.8 mmol/l; range 1.6-2.3) was induced by an intravenous infusion of regular insulin in eight patients with Type 1 (insulin-dependent) diabetes mellitus (age 28.0 +/- 7.4 years; mean +/- SD, duration 15.5 +/- 5.1 years) and in 12 age- matched healthy male control subjects. Multi-channel frequency analysis of electroencephalogram (electrophysiologic brain mapping) and recording of P300 and somatosensory evoked potentials were performed before, during and immediately after the hypoglycaemic period. The hypoglycaemia produced a significant increase in low frequency electroencephalographic activity in both groups, most pronounced over anterior regions of the brain. The electroencephalographic activity was normalised immediately after the hypoglycaemic period. The patients with diabetes showed somewhat longer P300 latencies during the initial normoglycaemic examination. Hypoglycaemia caused a marked reduction of the P300 amplitude in both groups of subjects and the amplitude was not restored immediately after normalisation of blood glucose levels. The somatosensory cortical responses were not affected by hypoglycaemia. We conclude that hypoglycaemia results in impairment in cerebral function, as measured by neurophysiological techniques, which is not immediately normalised when blood glucose is restored to normal.
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| 5. |
- Grubin, C. E., et al.
(författare)
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A novel radioligand binding assay to determine diagnostic accuracy of isoform-specific glutamic acid decarboxylase antibodies in childhood IDDM
- 1994
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Ingår i: Diabetologia. - 0012-186X. ; 37:4, s. 344-350
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Tidskriftsartikel (refereegranskat)abstract
- Insulin-dependent diabetes mellitus (IDDM) is associated with autoreactivity against GAD but the diagnostic sensitivity (positivity in disease) and specificity (negativity in health) of isoform-specific GAD antibodies have yet to be defined in assay systems suitable for screening large number of samples. One set of IDDM patient (n=10) and control (n=50) standard sera were used to develop quantitative antibody assays with in vitro synthesized recombinant 35S-methionine-labelled GAD65 and GAD67, respectively, and protein A-Sepharose to separate free from antibody-bound ligand. Binding levels were not normally distributed (p<0.0001) and therefore, the diagnostic accuracy of GAD antibodies was analysed by the ROC plots in population-based, consecutively-diagnosed, recent onset, 0-14 year-old patients (n=105), and matched, healthy control subjects (n=157). The ROC plots showed that the diagnostic sensitivity of GAD65 antibodies was 77% and the specificity 92% compared with 8% and 98%, respectively for GAD67 antibodies. In the IDDM sera, GAD65 and GAD67 antibodies were concordant in 7% (6 of 81) and GAD65 antibodies and ICA in 89% (72 of 81) without a correlation between the autoantibody levels. Autoantibodies to recombinant human islet GAD65 are specific and sensitive markers for childhood IDDM in this immunoassay with in vitro synthesized 35S-methioninelabelled recombinant GAD.
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| 6. |
- Landin-Olsson, M., et al.
(författare)
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Islet cell antibodies and fasting C-peptide predict insulin requirement at diagnosis of diabetes mellitus
- 1990
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Ingår i: Diabetologia. - 0012-186X. ; 33:9, s. 561-568
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Tidskriftsartikel (refereegranskat)abstract
- The differential diagnosis between Type 1 (insulin-dependent) and Type 2 (non-insulin-dependent) diabetes is complicated since no specific markers are available for either disease. In this study, 244 consecutive patients were diagnosed with diabetes mellitus during two years in Malmö (230000 inhabitants), corresponding to an incidence rate of 53·100000-1·year-1. Age, body mass index, HbA1c, C-peptide, and levels of islet cell antibodies were determined at the clinical onset, and related to the classification at diagnosis and at follow-up (n=233) after a median time of 31 (range 1-49) months. After diagnosis, 42 of 244 (17%) were started on insulin while 202 of 244 (83%) were not. Islet cell antibodies were present in 25 of 42 (60%), and in 18 of 183 (10%), respectively. In the non-insulin treated group, patients with islet cell antibodies had lower body mass index (p<0.001), higher HbA1c (p<0.004), and lower C-peptide (p<0.001) than patients without. At follow-up, 11 of 18 (61%) islet cell positive patients were changed to insulin treatment, as were six other patients. Insulin was discontinued in five initially insulin-treated but islet cell antibody negative patients. The sensitivity, specificity and predictive value for insulin treatment at follow-up were for islet cell antibody positivity; 72%, 96% and 84%, respectively, and for low C-peptide value; 60%, 96%, and 80%, respectively. Islet cell antibodies and low C-peptide at diagnosis of diabetes mellitus are concluded to be useful markers to predict insulin dependence.
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| 7. |
- Landin-Olsson, M, et al.
(författare)
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Predictive value of islet cell and insulin autoantibodies for type 1 (insulin-dependent) diabetes mellitus in a population-based study of newly-diagnosed diabetic and matched control children
- 1992
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Ingår i: Diabetologia. - 0012-186X. ; 35:11, s. 73-1068
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Tidskriftsartikel (refereegranskat)abstract
- Most studies evaluating immune markers for prediction of Type 1 (insulin-dependent) diabetes mellitus have focused on first degree relatives, although only 10% of newly-diagnosed patients have an affected first degree relative. The Swedish Childhood Diabetes Register identifies 99% of all diabetic children at diagnosis. In this population-based study, islet cell antibodies and insulin autoantibodies in 0-14-year-old Swedish consecutively-diagnosed patients and control subjects were analysed to define their sensitivity and specificity. Over 16 months (1986-1987), 515 Swedish children developed diabetes. Plasma samples were obtained from 494 (96%) patients, and 420 matched control children. Among patients, the frequency of islet cell antibodies was 84% (415 of 494), insulin autoantibodies 43% (145 of 334); 40% (135 of 334) were positive for both and 88% (294 of 334) were positive for one or both. Among control children, 3% (14 of 420) had islet cell antibodies, 1% (4 of 390) insulin autoantibodies, and 4% (16 of 390) had either autoantibody marker. The predictive value of finding a patient with the disease was only 7% since 4% of the control children were antibody-positive and the cumulative incidence rate up to 15 years of age is 0.38%. None of the autoantibody-positive (n = 21) or negative control children developed diabetes during 3 to 5 years of follow-up. Longitudinal investigations of islet cell or insulin-autoantibody-positive healthy children are necessary to accurately determine the conversion rate from marker positivity to disease onset.
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| 8. |
- Sairenji, T., et al.
(författare)
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Relating homology between the Epstein-Barr virus BOLF1 molecule and HLA-DQw8 β chain to recent onset Type 1 (insulin-dependent) diabetes mellitus
- 1991
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Ingår i: Diabetologia. - 0012-186X. ; 34:1, s. 33-39
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Tidskriftsartikel (refereegranskat)abstract
- A role for the Epstein-Barr virus in initiating Type 1 (insulin-dependent) diabetes mellitus has been proposed since Epstein-Barr virus BOLF1(497-513) AVTPL RIFIVP PAAEY has an 11 amino acid identity with HLA-DQw8 β (49-60) AVTPL GPPAAEY. Rabbit antisera to the BOLF1 (496-515) peptide crossreacted with the homologous DQw8 β (44-63) peptide but not with the related DQw7 β(44-63) peptide, which differed from the DQw8 peptide only in an ALA to ASP substitution in position 57. Antisera to DQw8 β(49-60) reacted with the DQw8 β(44-63) peptide and BOLF1 (496-515), but not with DQw7 β (44-63). The antiserum to the BOLF1 peptide bound to denatured class II major histocompatibility complex β chains from Epstein-Barr virus-transformed DQw8-positive lymphocytes in an immunoblotting analysis. Epstein-Barr virus antibodies were detected at equal frequencies and similar titres in sera of 30 patients with Type 1 diabetes (16 of 30;63%) and in sera of 20 non-diabetic control subjects (13 of 20;65%). Sera from diabetic patients did not bind to DQw8 β (44-63) or BOLF1(496-515) peptides. From these data we conclude that there is no simple relationship between serological evidence of Epstein-Barr virus infection and crossreactions between homologous Epstein-Barr virus and class II major histocompatibility complex peptides.
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| 9. |
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| 10. |
- Tallroth, G, et al.
(författare)
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Neurophysiological changes during insulin-induced hypoglycaemia and in the recovery period following glucose infusion in type 1 (insulin-dependent) diabetes mellitus and in normal man
- 1990
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Ingår i: Diabetologia. - 1432-0428. ; 33:5, s. 319-323
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Tidskriftsartikel (refereegranskat)abstract
- Hypoglycaemia (median venous blood glucose 1.8 mmol/l; range 1.6-2.3) was induced by an intravenous infusion of regular insulin in eight patients with Type 1 (insulin-dependent) diabetes mellitus (age 28.0 +/- 7.4 years; mean +/- SD, duration 15.5 +/- 5.1 years) and in 12 age-matched healthy male control subjects. Multi-channel frequency analysis of electroencephalogram (electrophysiologic brain mapping) and recording of P300 and somatosensory evoked potentials were performed before, during and immediately after the hypoglycaemic period. The hypoglycaemia produced a significant increase in low frequency electroencephalographic activity in both groups, most pronounced over anterior regions of the brain. The electroencephalographic activity was normalised immediately after the hypoglycaemic period. The patients with diabetes showed somewhat longer P300 latencies during the initial normoglycaemic examination. Hypoglycaemia caused a marked reduction of the P300 amplitude in both groups of subjects and the amplitude was not restored immediately after normalisation of blood glucose levels. The somatosensory cortical responses were not affected by hypoglycaemia. We conclude that hypoglycaemia results in impairment in cerebral function, as measured by neurophysiological techniques, which is not immediately normalised when blood glucose is restored to normal.
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