Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011854 (type 1 diabetes)
 20,749 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Insulin-like growth factor binding proteins interfere in the IGF-I and -II radioimmunoassays. In an attempt to overcome this problem, we have compared the use of truncated IGF-I, with reduced IGFBP affinity, and IGF-I as radioligands for IGF-I RIA measurements in serum separated by acid gel filtration or acid ethanol extraction followed by cryo-precipitation. With truncated IGF-I as radioligand the IGF-I measurements in acid gel filtrates and acid ethanol extracts were significantly correlated in healthy subjects (N = 42, r = 0.91, p less than 0.001) and in patients with acromegaly (N = 10, r = 0.85, p less than 0.01), GH deficiency (N = 10, r = 0.88, p less than 0.001) or Type I diabetes mellitus (N = 10, r = 0.90, p less than 0.001). In contrast, the IGF-I concentrations in acid ethanol extracts determined with IGF-I as radioligand did not correlate with those in acid gel filtrates using truncated IGF-I radioligand in patients with acromegaly (r = 0.61, NS) or GH deficiency (r = 0.46, NS). In the latter group the mean IGF-I concentrations measured in acid ethanol extracts were erroneously elevated by 112%. Low-affinity antibodies used for IGF-II RIA determinations failed to give reliable results in acid ethanol extracts from patients with Type I diabetes mellitus or GH deficiency. In conclusion, erroneously high IGF-I concentrations owing to binding of the radioligand to IGFBPs not completely removed by acid ethanol extraction can be avoided by the use of truncated IGF-I as radioligand.
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PMID:Comparison of acid ethanol extraction and acid gel filtration prior to IGF-I and IGF-II radioimmunoassays: improvement of determinations in acid ethanol extracts by the use of truncated IGF-I as radioligand. 206 92

The serum levels of the low mol wt form of somatomedin-binding protein (SMBP) were 5-fold higher in both diabetic (n = 44) and nondiabetic pregnant women (n = 14) than in nonpregnant women. No difference was found between women with type 1 diabetes and those with gestational diabetes. There was a negative correlation between maternal levels of SMBP during the last trimester and the birth weight percentile of the infants (r = -0.51). There was a 2- to 3-fold elevation of maternal insulin-like growth factor (IGF-I) levels during pregnancy in both diabetic and nondiabetic women. A positive correlation (r = 0.49) was found between maternal IGF-I levels and the birth weight percentiles of their infants. The correlation between the ratio of IGF-I to SMBP, which may reflect the IGF-I available to the placenta, to birth weight percentile was higher (r = 0.57), and the SE of estimate of weight percentile was 23%. The ratio between IGF-I and SMBP in cord blood was correlated with birth weight, although cord blood IGF-I and SMBP values were not. The IGF-II levels in cord serum were 50% higher in the infants of diabetic than in those of nondiabetic mothers. These findings raise the questions of whether maternal SMBP levels influence the amount of IGF-I available for the fetal-placental unit and whether IGF-II participates in glucose homeostasis in the fetus.
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PMID:Serum levels of somatomedins and somatomedin-binding protein in pregnant women with type I or gestational diabetes and their infants. 243 Sep 89

Insulin-dependent diabetes mellitus (IDDM) during puberty is associated with a reduction in circulating concentrations of insulin-like growth factor-I (IGF-I) and low IGF bioactivity. Altered levels of the IGF-binding proteins (IGFBPs), including low IGFBP-3 and elevated IGFBP-1, have also been described. These abnormalities have been linked to poor growth and deteriorating blood glucose control. We have therefore examined the effects of recombinant human IGF-I (rhIGF-I) administration on the levels of IGF-I, IGF-II, IGFBP-1, IGFBP-3 and IGF bioactivity in a group of 9 late-pubertal adolescents with IDDM. This was a double-blind placebo controlled study with each individual admitted on two occasions when either rhIGF-I (40 micrograms/kg) or placebo was administered by subcutaneous injection in the thigh at 1800 h. Blood samples were then taken for the subsequent 22 h. The half-life of administered rhIGF-I (12.1-22.2 h) was similar to that previously described in normal subjects. There was a small increase in IGFBP-3 concentrations overnight following rhIGF-I administration when compared to placebo, whereas the levels of IGF-II decreased. Under strict euglycaemic conditions, the relationship between insulin and IGFBP-I did not appear to be affected by rhIGF-I administration although the levels of IGFBP-1 tended to be higher overnight. IGF bioactivity was low during the placebo study, and although within the normal adult range following administration of IGF-I, was still relatively low for adolescents in late puberty.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The effects of recombinant human insulin-like growth factor-I (IGF-I) administration on the levels of IGF-I, IGF-II and IGF-binding proteins in adolescents with insulin-dependent diabetes mellitus. 752 62

To evaluate the role of insulin-like growth factors (IGFs) and IGF-binding proteins (IGFBPs) in excessive fetal growth (macrosomia) in diabetic pregnancy, 84 insulin-treated diabetic mothers and their infants were tested for serum concentrations of IGF-I, IFG-II, and IGFBP-1, -2 and -3. These parameters were correlated with the birth weight of neonates and placental weight. IGF-I and II levels were determined by specific radioimmunoassays (RIAs) after serum samples were extracted with aid-ethanol. IGFBPs were measured by Western immunoblot with specific antibodies to the respective IGFBP species. Serum concentrations of both IGF-I and IGF-II in mothers with either IDDM or NIDDM increased with the gestational period, reached a plateau at the third trimester, and returned to non-pregnant levels within 7 days after delivery. These values were not different from those in normal mothers before and throughout pregnancy. As previously reported, IGF-I concentrations in cord serum of neonates born to diabetic mothers were (P < 0.01) higher than those of newborns of normal mothers. Likewise, cord blood IGF-II levels were 2-fold higher in babies of diabetic mothers (P <0.001). Fetal IGF-I and IGF-II correlated with each other and with maternal HbA1C, and they positively correlated with either birth weight or placental weight. Cord IGFBP-3 concentrations were significantly higher in diabetic pregnancy, but IGFBP-2 concentrations were not different from those in normal pregnancy. Cord IGFBP-1 concentrations were significantly higher only in babies of mothers with IDDM. None of these cord IGFBP concentrations correlated with birth weight or placental weight. The data suggest that fetal IGF-II, like IGF-I, is involved in fetal and placental growth in diabetic pregnancy. The role of IGFBPs remained to be determined.
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PMID:Insulin-like growth factors (IGFs) and IGF-binding proteins (IGFBP-1, -2 and -3) in diabetic pregnancy: relationship to macrosomia. 902 69

Although the shortest (class I) minisatellite (i.e., variable number of tandem repeats [VNTR]) alleles in the 5' region of the insulin gene are positively associated with IDDM in Caucasians, the majority of Japanese are homozygous for class I alleles. Here, we determined the exact length, in number of repeat units (RUs), of class I alleles in Japanese subjects. The distribution of class I alleles in Japanese was trimodal, with peaks located at 32/33, 41, and 44 RUs. The shortest component (i.e., 1S [25-38 RUs]) alleles were significantly increased in the IDDM group compared with the control group (54 vs. 46%; P = 0.040). The 1S/1S genotype was significantly increased in the IDDM patients (34 vs. 20%; P = 0.005; relative risk 2.1). Furthermore, the transmission disequilibrium test of Japanese families with 1S/1M or 1S/1L heterozygous parents confirmed the association of 1S alleles; 17 alleles of 1S and 6 alleles of 1M (39-41 RUs) or 1L (42-44 RUs) were transmitted to affected offspring (P = 0.022). In addition, we found tight linkage of 1S with allele 9 of the tyrosine hydroxylase gene microsatellite and allele (-) of the IGF-II gene Apa I polymorphism, but neither 9 nor (-) alleles were significantly associated with IDDM. The present study suggests that a class I subset may have a role in IDDM susceptibility in Japan. It was revealed that the difference between 1S alleles and 1M or 1L alleles is almost consistently characterized by a sequence variation generated by deletion of two copies of an ACAGGGGTCC CGGGG repeat element, implying that sequence variation of class I alleles may influence disease susceptibility.
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PMID:Evidence for association between the class I subset of the insulin gene minisatellite (IDDM2 locus) and IDDM in the Japanese population. 931 62

We report on a 33-year-old male patient with generalized acquired lipodystrophy, insulin resistant diabetes mellitus and acanthosis nigricans (Lawrence Syndrome). First probable symptoms of lipodystrophy (weight loss, shrinkage of subcutaneous fatty tissue, and loss of muscular strength) became evident three years ago, with the onset of diabetes mellitus occurring about six months later. The patient suffered from the following clinical symptoms: IDDM with increasing insulin-requirement, extreme reduction of fatty tissue, fatty liver hepatitis with elevated liver enzymes, glomerulopathy, muscular and neuropathic pains, as well as hypertriglyceridaemia. A basal C-peptide concentration is rather high. Definitely, the endogenous insulin secretion is increased. In other words, insulin resistance is documented. In an effort to identify the pathogenetic mechanisms of lipoatrophic diabetes mellitus in this patient and to develop a therapeutic strategy, antibodies against different tissues and endocrinologic regulation were investigated. It was possible to demonstrate the presence of serum autoantibodies against lipocytes of the subcutis and other tissues, against hepatic stellate cells, together with autoantibodies against different endocrine organs. By studying the basis of diabetic abnormalities relating to the growth hormone (GH), the insulin-like growth factor (IGF) dynamics in this patient, i.e. reductions of GH, IGF-I, IGF-II, IGF-Binding protein (IGF-BP) 2 and IGF-BP 3, were detected. An immunosuppressive treatment strategy was not beneficial.
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PMID:Dysregulation of insulin-like growth factors in a case of generalized acquired lipoatrophic diabetes mellitus (Lawrence Syndrome) connected with autoantibodies against adipocyte membranes. 951 65

Diabetes mellitus and glucose dysregulation have significant effects on the circulating level of insulin-like growth factor-I (IGF-I) and IGF binding proteins (IGFBPs). In the present study, serum and urine IGFBP (IGFBP-1, -2, and -3) and serum IGF-I and -II levels were measured by radioimmunoassay (RIA) in 27 patients with type 1 diabetes aged 9 to 48 years compared with 9 healthy subjects aged 10 to 28 years. The patients were divided into 3 groups according to the amount of albumin excreted in 24 hours. The macroalbuminuria group (>500 mg/24 h) had elevated serum IGFBP-1 and -2 and decreased IGF-I levels (P < .01 v normal controls). Serum IGFBP-3 and IGF-II were not different among the patient groups and controls (P > .05). The mean urinary IGFBP-1 was decreased in all 3 patient groups compared with the controls (P < .05). Urinary IGFBP-2 and IGFBP-3 were increased in patients with macroalbuminuria. Immunoblot analysis showed increased low-molecular-weight fragments of urinary IGFBP-2 in the poorly controlled diabetics, and direct evidence for increased urinary IGFBP-2 proteolytic activity could be demonstrated in both the microalbuminuric and macroalbuminuric groups. Low-molecular-weight fragments of urinary IGFBP-3 were also increased in both the microalbuminuric and macroalbuminuric groups. In conclusion, alterations of IGFBPs in urine and serum are related to metabolic control in diabetic patients, and there is an increase of urinary IGFBP-2 protease activity in poorly controlled diabetics. The changes in serum IGFBP concentrations (eg, increases in IGFBP-1 and IGFBP-2) may lead to alterations in the availability of IGF-I to peripheral tissues.
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PMID:Insulin-like growth factor binding proteins (IGFBPs) in serum and urine and IGFBP-2 protease activity in patients with insulin-dependent diabetes mellitus. 1083 Nov 74

To determine the role of IGF-binding proteins in mediating the direct effects of recombinant human IGF-I on insulin requirements in type 1(insulin-dependent) diabetes mellitus, overnight changes in IGF-I, IGF-II, and IGF-binding protein-1, -2, and -3, collected under euglycemic conditions, were compared in nine subjects after double blind, randomized, sc administration of recombinant human IGF-I (40 microg/kg) or placebo at 1800 h. On both nights a somatostatin analog infusion (300 ng/kg x h) suppressed endogenous GH production, and three timed discrete GH pulses (total, 0.029 IU/kg x night) ensured identical GH levels. After recombinant human IGF-I administration, IGF-I levels and the IGF-I/IGF-binding protein-3 ratio increased [mean +/- SEM:IGF-I, 401 +/- 22 ng/ml; placebo, 256 +/- 20 ng/ml (P = 0.0002); IGF-I, 0.108 +/- 0.006; placebo, 0.074 +/- 0.004 (P = 0.0003), respectively], and insulin requirements decreased (IGF-I, 0.12 +/- 0.03; placebo, 0.23 +/- 0.03 U/kg x min; P = 0.008). The normal within-individual inverse relationships between insulin and IGF-binding protein-1 levels were observed (lag time 2 h: r = -0.34; P < 0.01). Yet despite reduced free insulin levels (8.5 +/- 1.5; placebo, 12.2 +/- 1.2 mU/liter; P = 0.03), IGF-binding protein-1 levels were reduced after recombinant human IGF-I administration (53.7 +/- 6.8; placebo, 82.2 +/- 11.8 ng/ml; P = 0.008). The largest reductions in free insulin levels after recombinant human IGF-I and thus putative improvement in insulin sensitivity occurred in subjects with the smallest increase in the plasma IGF-I/IGF-binding protein-3 ratio (r = 0.7; P = 0.03). Taken together, these data are consistent with the hypothesis that transcapillary movement of IGF-I (perhaps mediated by IGF-binding protein-1), out of the circulation facilitates altered insulin sensitivity. These data have important implications for risk-benefit assessment of recombinant human IGF-I therapy in type 1 diabetes mellitus.
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PMID:The role of IGF-binding proteins in mediating the effects of recombinant human IGF-I on insulin requirements in type 1 diabetes mellitus. 1150 96

This review presents a brief overview of the cell's apoptotic machinery, including specific and indirect death signals. Specific death signals are transferred via death ligands, death receptors, and their intracellular signalling pathways. Indirect death signals cumulate a wide range of stimuli that potentially harm survival of cells. These include intercalating drugs, irradiation or altered intracellular signalling. Herein, a focal point is the mitochondrial control of specific death enzymes--so called caspases--by members of the pro-apoptotic Bax and BH3 subfamily or the anti-apoptotic Bcl-2 subfamily. While the initiation of cell death happens through a variety of signalling systems, the activation of caspases plays a pivotal role in the progression towards the final morphologic findings in cells undergoing apoptosis. Caspases appear to directly cleave and inactivate substrates that are clinical for the maintenance of cell structure and function but also regulate the activity of other enzymes that induce the apoptotic phenotype within the cell. The insulin-like growth factors (IGFs) are potent proliferation factors and potently inhibit apoptosis acting via the ubiquitously expressed IGF-I receptor. Within IGF-I receptor signalling, key to the inhibition of apoptosis are the RAS/RAF/mitogen-activated protein (MAP)-kinase pathway and the PI 3'-kinase pathway. To give an example of high clinical relevance of apoptosis within endocrine disorders, apoptotic death of pancreatic beta cells in type 1 diabetes disease and the involvement of IGF-II in beta cell survival and beta cell function is discussed in detail. Finally, further understanding of signalling systems that are involved in proliferation or in apoptosis might provide novel tools to treat or even heal disorders like type I diabetes.
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PMID:Apoptosis: live or die--hard work either way! 1156 Dec 9

Correlation studies have suggested that IGF-binding protein (IGFBP)-1 is a dynamic regulator of free IGF-I. To further study this, we developed a monoclonal immunofluorometric assay specific for the binary complex of IGF-I and IGFBP-1 in human serum. An IGFBP-1 antibody, which recognizes all phospho-forms of IGFBP-1, was used for coating. An europium-labeled IGF-I antibody served as tracer. Assay incubation was performed at conditions approaching those in vivo (i.e. pH 7.4, 37 C). The assay was highly specific: no signal was obtained unless both IGF-I and IGFBP-1 were present and neither IGFBP-2, -3, -4, nor IGF-II caused any cross-reaction. The linear standard curve covered 3 orders of magnitude, and within and in-between assay coefficients of variation were less than 5 and 15%, respectively. To study the dynamic relationship between free IGF-I and binary complex formation, seven healthy subjects were fasted for 72 h. Samples were collected every 3 h. During fasting, free IGF-I was reduced by two thirds (P < 0.0001). IGFBP-1 and the binary complex increased in parallel (P < 0.0001), and levels correlated positively in all subjects (0.89 < or = r < or = 0.98; P < 0.0001). Free IGF-I correlated inversely with IGFBP-1 (-0.81 < or = r < or = -0.48; 0.0001 < or = P < or = 0.05) and the binary complex (-0.79 < or = r < or = -0.41; 0.0001 < or = P < or = 0.05). To study overnight fasting levels, we compared healthy controls and patients with type 1 diabetes and chronic renal failure (n = 10), because these patients show profound alterations in their IGF-system. In both groups, the binary complex was increased about 2.5-fold (P < 0.0001), whereas IGFBP-1 was increased by 5- to 6-fold (P < 0.0001). Accordingly, free IGF-I was severely reduced (P < 0.0001). In conclusion, the assay enables us to study the role of IGFBP-1 as a dynamic regulator of free IGF-I. Our results clearly show that IGFBP-1 and free IGF-I are tightly associated peptides. Furthermore, it has now become possible to compare levels of IGF-I carried within the binary complex IGFBP-1:IGF-I in different (patho-) physiological conditions.
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PMID:Development and clinical evaluation of a novel immunoassay for the binary complex of IGF-I and IGF-binding protein-1 in human serum. 1178 56


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