PubMed Health⌕ Search

Biomedical subjects

Karsten Müssig

Publications and source records attributed to Karsten Müssig.

12 recordsLinked to original sources
PubMed2006

[Lipohypertrophy].

Explore the source record for details and available documents.

Abdominal Fat↗
PubMed2006

Iodine-induced thyrotoxicosis after ingestion of kelp-containing tea.

Complementary medication is en vogue and an increasing number of patients consume herbal medicine without reporting their use to physicians. We report a case of iodine-induced hyperthyroidism due to the ingestion of a kelp-containing tea. A 39-year-old woman with multinodular goiter presented with typical signs of hyperthyroidism, which was confirmed by endocrine tests. She was not exposed to iodinated radiocontrast media and did not take medications containing iodine, such as amiodarone. However, a detailed medical history revealed that she had been treated for a period of 4 weeks by a Chinese alternative practitioner with a herbal tea containing kelp because of her enlarged thyroid. The consumption of the tea was discontinued and an antithyroid drug therapy was initiated. Physicians should advise patients with underlying thyroid disease to avoid all complementary or alternative medications containing iodine.

Adult↗
PubMed2005

Insulin-induced stimulation of JNK and the PI 3-kinase/mTOR pathway leads to phosphorylation of serine 318 of IRS-1 in C2C12 myotubes.

Increased serine/threonine phosphorylation of insulin receptor substrate-1 (IRS-1) is associated with cellular insulin resistance. We have recently identified serine 318 (Ser318) as a novel protein kinase C-zeta (PKC-zeta)-dependent phosphorylation site within IRS-1. As other kinases may phosphorylate at this serine residue as well, we aimed to identify such kinases in the present study. In C2C12 myotubes, exposure to insulin or phorbol ester markedly increased Ser318 phosphorylation. In contrast, high glucose, tumor necrosis factor-alpha, and free fatty acids did not provoke Ser318 phosphorylation. JNK and the PI 3-kinase/mTOR pathway were found to be implicated in insulin-induced Ser318 phosphorylation, but not in TPA-stimulated phosphorylation that was, at least partly, mediated by classical or novel PKC. In conclusion, with JNK and the PI 3-kinase/mTOR pathway as mediators of insulin-induced Ser318 phosphorylation, we have identified kinases that have previously been reported to play key roles in phosphorylation of other serine residues in IRS-1.

Animals↗
PubMed2005

Shp2 is required for protein kinase C-dependent phosphorylation of serine 307 in insulin receptor substrate-1.

The function of insulin receptor substrate-1 (IRS-1), a key molecule of insulin signaling, is modulated by phosphorylation at multiple serine/threonine residues. Phorbol ester stimulation of cells induces phosphorylation of two inhibitory serine residues in IRS-1, i.e. Ser-307 and Ser-318, suggesting that both sites may be targets of protein kinase C (PKC) isoforms. However, in an in vitro system using a broad spectrum of PKC isoforms (alpha, beta1, beta2, delta, epsilon, eta, mu), we detected only Ser-318, but not Ser-307 phosphorylation, suggesting that phorbol ester-induced phosphorylation of this site in intact cells requires additional signaling elements and serine kinases that link PKC activation to Ser-307 phosphorylation. As we have observed recently that the tyrosine phosphatase Shp2, a negative regulator of insulin signaling, is a substrate of PKC, we studied the role of Shp2 in this context. We found that phorbol ester-induced Ser-307 phosphorylation is reduced markedly in Shp2-deficient mouse embryonic fibroblasts (Shp2-/-) whereas Ser-318 phosphorylation is unaltered. The Ser-307 phosphorylation was rescued by transfection of mouse embryonic fibroblasts with wild-type Shp2 or with a phosphatase-inactive Shp2 mutant, respectively. In this cell model, tumor necrosis factor-alpha-induced Ser-307 phosphorylation as well depended on the presence of Shp2. Furthermore, Shp2-dependent phorbol ester effects on Ser-307 were blocked by wortmannin, rapamycin, and the c-Jun NH2-terminal kinase (JNK) inhibitor SP600125. This suggests an involvement of the phosphatidylinositol 3-kinase/mammalian target of rapamycin cascade and of JNK in this signaling pathway resulting in IRS-1 Ser-307 phosphorylation. Because the activation of these kinases does not depend on Shp2, it is concluded that the function of Shp2 is to direct these activated kinases to IRS-1.

Androstadienes↗
PubMed2005

17alpha-hydroxylase/17,20-lyase deficiency caused by a novel homozygous mutation (Y27Stop) in the cytochrome CYP17 gene.

CONTEXT: 17alpha-Hydroxylase/17,20-lyase deficiency, a rare autosomal recessive form of congenital adrenal hyperplasia, is caused by mutations in the cytochrome P450c17 (CYP17) gene. We report on a case of complete 17alpha-hydroxylase/17,20-lyase deficiency due to a novel homozygous mutation of CYP17. DESIGN: A 20-yr-old female Turkish patient (46,XX) presented with primary amenorrhea, sexual infantilism, and easy fatigability. RESULTS: The patient's steroid metabolism showed increased levels of mineralocorticoid precursors and low or undetectable plasma concentrations of 17alpha-hydroxycorticoids, androgens, and estrogens before and after ACTH stimulation. The gas chromatography-mass spectrometry urinary steroid profile was dominated by metabolites of corticosterone and its precursors, while cortisol and C(19)-steroid metabolites were lacking. ACTH, FSH, and LH levels were elevated. These hormonal findings were consistent with a combined and total 17alpha-hydroxylase/17,20-lyase deficiency. A therapy with hydrocortisone and a cyclic estrogen/gestagen substitution was initiated. CONCLUSION: The CYP17 gene analysis revealed homozygosity of the mutation Y27Stop (TAC-->TAA) in exon 1, a mutation that has not been previously described. This novel mutation leads to a stop codon causing a total loss of 17alpha-hydroxlyase/17,20-lyase activity, as reflected biochemically by the detected concentrations of the steroid metabolites.

Adrenocorticotropic Hormone↗
PubMed2005

Hashimoto's encephalopathy presenting with bipolar affective disorder.

OBJECTIVE: We report on a rare case of Hashimoto's encephalopathy associated with a bipolar affective disorder. CASE REPORT: A 32-year-old woman presented with a bipolar affective disorder and Hashimoto's thyroiditis. Neurological investigations (magnetic resonance imaging of the brain and cerebrospinal fluid) did not reveal any pathological findings except for a pathological electroencephalogram (EEG). Despite consequent antidepressant treatment, the patient remitted only in conjunction with normalization of the EEG after short-term treatment with high doses of prednisolone. CONCLUSION: In treatment resistant courses of disorders, the thorough clinical and laboratory investigation of our patient revealed a very efficient treatment strategy. Cases of Hashimoto's encephalopathy associated with the occurrence of a manic episode and hence with bipolar disorder are rare; this is the first reported case. However, clinicians should be alert to this possibility.

Adult↗