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- Bausch, Birke, et al.
(författare)
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Germline NF1 mutational spectra and loss-of-heterozygosity analyses in patients with pheochromocytoma and neurofibromatosis type 1.
- 2007
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Ingår i: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 92:7, s. 2784-92
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Neurofibromatosis type 1 (NF1) is a pheochromocytoma-associated syndrome. Because of the low prevalence of pheochromocytoma in NF1, we ascertained subjects by pheochromocytoma that also had NF1 in the hope of describing the germline NF1 mutational spectra of NF1-related pheochromocytoma.MATERIALS AND METHODS: An international registry for NF1-pheochromocytomas was established. Mutation scanning was performed using denaturing HPLC for intragenic variation and quantitative PCR for large deletions. Loss-of-heterozygosity analysis using markers in and around NF1 was performed.RESULTS: There were 37 eligible subjects (ages 14-70 yr). Of 21 patients with corresponding tumor available, 67% showed somatic loss of the nonmutated allele at the NF1 locus vs. 0 of 12 sporadic tumors (P = 0.0002). Overall, 86% of the 37 patients had exonic or splice site mutations, 14% large deletions or duplications; 79% of the mutations are novel. The cysteine-serine rich domain (CSR) was affected in 35% but the RAS GTPase activating protein domain (RGD) in only 13%. There did not appear to be an association between any clinical features, particularly pheochromocytoma presentation and severity, and NF1 mutation genotype.CONCLUSIONS: The germline NF1 mutational spectra comprise intragenic mutations and deletions in individuals with pheochromocytoma and NF1. NF1 mutations tended to cluster in the CSR over the RAS-GAP domain, suggesting that CSR plays a more prominent role in individuals with NF1-pheochromocytoma than in NF1 individuals without this tumor. Loss-of-heterozygosity of NF1 markers in NF1-related pheochromocytoma was significantly more frequent than in sporadic pheochromocytoma, providing further molecular evidence that pheochromocytoma is a true component of NF1.
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2. |
- Brabant, Georg, et al.
(författare)
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Clinical implications of residual growth hormone (GH) response to provocative testing in adults with severe GH deficiency
- 2007
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Ingår i: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 92:7, s. 2604-2609
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Tidskriftsartikel (refereegranskat)abstract
- Context: The diagnosis of GH deficiency (GHD) in adults is based on provocative tests of GH release, all influenced by clinical factors. It is unknown whether the amount of residual GH reserve under the cutoff value has any physiological implication. Objectives: We used a large pharmacoepidemiological database of adult GHD (KIMS) and tested the impact of confounding factors on GH release of no greater than 3 µg/liter after an insulin tolerance test (ITT) and evaluated its potential physiological role. Design, Settings, and Patients: A total of 1098 patients fulfilled the criteria of having a GH peak of no greater than 3 µg/liter during ITT as well as documented IGF-I levels. Outcomes: The impact of underlying hypothalamic-pituitary disease, age, gender, body weight, as well as treatment modalities such as irradiation on peak GH level to ITT was evaluated, and the correlations between GH peak and targets of GH action were analyzed. Results: The GH response to ITT was regulated by gender, age, and the number of additional pituitary deficiencies. In a multivariate evaluation, the extent of hypothalamic-pituitary dysfunction was the most important single predictor of GH peak in ITT. GH peaks in ITT were positively related to IGF-I levels and high-density lipoprotein-cholesterol, as well as inversely to triglycerides. Conclusions: Even in adult severe GHD, GH release appears to be regulated by factors defined to play an important role in normal GH secretion. The impact of very low GH release on IGF-I and lipid parameters indicates a persistent physiological role of low GH concentrations in severely affected patients with GHD.
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- Kempf, Tibor, et al.
(författare)
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Circulating concentrations of growth-differentiation factor 15 in apparently healthy elderly individuals and patients with chronic heart failure as assessed by a new immunoradiometric sandwich assay
- 2007
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Ingår i: Clinical Chemistry. - : Oxford University Press (OUP). - 0009-9147 .- 1530-8561. ; 53:2, s. 284-291
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Growth-differentiation factor 15 (GDF15) is a member of the transforming growth factor beta (TGF-beta) cytokine superfamily. There has been increasing interest in using circulating GDF15 as a biomarker in patients, for example those with cardiovascular disease. METHODS: We developed an IRMA that uses a polyclonal, affinity chromatography-purified goat antihuman GDF15 IgG antibody, assessed the preanalytic characteristics of GDF15, and determined circulating GDF15 concentrations in 429 apparently healthy elderly individuals and 153 patients with chronic heart failure (CHF). RESULTS: The assay had a detection limit of 20 ng/L, an intraassay imprecision of < or =10.6%, and an interassay imprecision of < or =12.2%. Specificity was demonstrated with size-exclusion chromatography, parallel measurements with polyclonal and monoclonal anti-GDF15 antibody, and lack of cross-reactivity with TGF-beta. The assay was not appreciably influenced by the anticoagulant matrix or unrelated biological substances. GDF15 was stable at room temperature for 48 h and resistant to 4 freeze-thaw cycles. Apparently healthy, elderly individuals presented with a median GDF15 concentration of 762 ng/L (25th-75th percentiles, 600-959 ng/L). GDF15 concentrations were associated with age and with cystatin C and C-reactive protein concentrations. CHF patients had increased GDF15 concentrations that were closely related to disease severity. CONCLUSION: The IRMA can detect GDF15 in human serum and plasma with excellent sensitivity and specificity. The reference limits and confounding variables defined for apparently healthy elderly individuals and the favorable preanalytic characteristics of GDF15 are expected to facilitate future studies of GDF15 as a biomarker in various disease settings, including CHF.
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4. |
- Wollert, Kai C., et al.
(författare)
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Prognostic value of growth-differentiation factor-15 in patients with non-ST-elevation acute coronary syndrome
- 2007
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Ingår i: Circulation. - 0009-7322 .- 1524-4539. ; 115:8, s. 962-971
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Growth-differentiation factor-15 (GDF-15) is a member of the transforming growth factor-beta cytokine superfamily that is induced in the heart after ischemia-and-reperfusion injury. Circulating levels of GDF-15 may provide prognostic information in patients with non-ST-elevation acute coronary syndrome. METHODS AND RESULTS: Blood samples were obtained on admission from 2081 patients with acute chest pain and either ST-segment depression or troponin elevation who were included in the Global Utilization of Strategies to Open Occluded Arteries (GUSTO)-IV Non-ST-Elevation Acute Coronary Syndrome trial and from a matching cohort of 429 apparently healthy individuals. GDF-15 levels were determined by immunoradiometric assay. Approximately two thirds of patients presented with GDF-15 levels above the upper limit of normal in healthy controls (1200 ng/L); one third presented with levels >1800 ng/L. Increasing tertiles of GDF-15 were associated with an enhanced risk of death at 1 year (1.5%, 5.0%, and 14.1%; P<0.001). By multiple Cox regression analysis, only the levels of GDF-15 and N-terminal pro-B-type natriuretic peptide, together with age and a history of previous myocardial infarction, contributed independently to 1-year mortality risk. Receiver operating characteristic curve analyses further illustrated that GDF-15 is a strong marker of 1-year mortality risk (area under the curve, 0.757; best cutoff, 1808 ng/L). At this cutoff value, GDF-15 added significant prognostic information in patient subgroups defined by age; gender; time from symptom onset to admission; cardiovascular risk factors; previous cardiovascular disease; and the risk markers ST-segment depression, troponin T, N-terminal pro-B-type natriuretic peptide, C-reactive protein, and creatinine clearance. CONCLUSIONS: GDF-15 is a new biomarker of the risk for death in patients with non-ST-elevation acute coronary syndrome that provides prognostic information beyond that provided by established clinical and biochemical markers.
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