221 resultados para pituitary hormonal deficiency


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The case of a 20 month-old girl that was admitted to the emergency ward because of worsening of her general condition in the setting of acute non-bloody gastroenteritis is reported. The clinical examination revealed signs of severe dehydration and a prominent tender abdomen. Laboratory evaluation showed leucocytosis, elevated C-reactive protein and severe hypochromic microcytic anemia. Abdominal X-ray revealed diffuse meteorism. The child underwent laparascopic evaluation. A perforated Meckel's diverticulum was found. Perforation and anemia due to occult bleeding are unusual presentations of Meckel's diverticulum. The differential diagnosis of children presenting with an acute abdomen with special focus on Meckel's diverticulum is discussed.

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In 1960, the first case report on factor XIII deficiency was published describing a seven-year-old Swiss boy with a so far unknown bleeding disorder. Today, more than 60 mutations in the factor XIIIA- and B-subunit genes are known leading to congenital factor XIII deficiency. In the present study, we describe six novel mutations in the factor XIII A-subunit gene. Additionally, we present the molecular characterisation of the first described patient with congenital factor XIII deficiency. The six novel mutations include a small deletion, Glu202 delG, leading to a premature stop codon and truncation of the protein, and a splice site mutation at the exon 10/intron 10 boundary, +1G/A, giving rise to an incorrect spliced mRNA lacking exons 10 and 11. The remaining four mutations are characterised by the single amino acid changes Met159Arg, Gly215Arg, Trp375Cys, and His716Arg, and were expressed in COS-1 cells. Antigen levels and activity of the mutants were significantly reduced compared to the wild-type. The patient described in 1960 also shows a single amino acid change, Arg77Cys. Structural analysis of all mutant enzymes suggests several mechanisms leading to destabilisation of the protein.

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PURPOSE OF REVIEW: P450 oxidoreductase deficiency--a newly described form of congenital adrenal hyperplasia--typically presents a steroid profile suggesting combined deficiencies of steroid 21-hydroxylase and 17alpha-hydroxylase/17,20-lyase activities. These and other enzymes require electron donation from P450 oxidoreductase. The clinical spectrum of P450 oxidoreductase deficiency ranges from severely affected children with ambiguous genitalia, adrenal insufficiency and the Antley-Bixler skeletal malformation syndrome to mildly affected individuals with polycystic ovary syndrome. We review current knowledge of P450 oxidoreductase deficiency and its broader implications. RECENT FINDINGS: Since the first report in 2004, at least 21 P450 oxidoreductase mutations have been reported in over 40 patients. The often subtle manifestations of P450 oxidoreductase deficiency suggest it may be relatively common. P450 oxidoreductase deficiency, with or without Antley-Bixler syndrome, is autosomal recessive, whereas Antley-Bixler syndrome without disordered steroidogenesis is caused by autosomal dominant fibroblast growth factor receptor 2 mutations. In-vitro assays of P450 oxidoreductase missense mutations based on P450 oxidoreductase-supported P450c17 activities provide excellent genotype/phenotype correlations. The causal connection between P450 oxidoreductase deficiency and disordered bone formation remains unclear. SUMMARY: P450 oxidoreductase mutations cause combined partial deficiency of 17alpha-hydroxylase and 21-hydroxylase. Individuals with an Antley-Bixler syndrome-like phenotype presenting with sexual ambiguity or other abnormalities in steroidogenesis should be analyzed for P450 oxidoreductase deficiency.

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The Ca(2+)-binding proteins parvalbumin (PV) and calbindin D-28k (CB) are key players in the intracellular Ca(2+)-buffering in specific cells including neurons and have profound effects on spatiotemporal aspects of Ca(2+) transients. The previously observed increase in mitochondrial volume density in fast-twitch muscle of PV-/- mice is viewed as a specific compensation mechanism to maintain Ca(2+) homeostasis. Since cerebellar Purkinje cells (PC) are characterized by high expression levels of the Ca(2+) buffers PV and CB, the question was raised, whether homeostatic mechanisms are induced in PC lacking these buffers. Mitochondrial volume density, i.e. relative mitochondrial mass was increased by 40% in the soma of PV-/- PC. Upregulation of mitochondrial volume density was not homogenous throughout the soma, but was selectively restricted to a peripheral region of 1.5 microm width underneath the plasma membrane. Accompanied was a decreased surface of subplasmalemmal smooth endoplasmic reticulum (sPL-sER) in a shell of 0.5 microm thickness underneath the plasma membrane. These alterations were specific for the absence of the "slow-onset" buffer PV, since in CB-/- mice neither changes in peripheral mitochondria nor in sPL-sER were observed. This implicates that the morphological alterations are aimed to specifically substitute the function of the slow buffer PV. We propose a novel concept that homeostatic mechanisms of components involved in Ca(2+) homeostasis do not always occur at the level of similar or closely related molecules. Rather the cell attempts to restore spatiotemporal aspects of Ca(2+) signals prevailing in the undisturbed (wildtype) situation by subtly fine tuning existing components involved in the regulation of Ca(2+) fluxes.

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Summary. Background: Accurate estimates of the incidence of thrombotic thrombocytopenic purpura (TTP) are important to assess the resources required for current treatments as well as to anticipate the need to develop new treatments. Previous estimates have been indirect and have not reported data on patients with ADAMTS-13 deficiency. Objective: To determine the incidence of patients with TTP-hemolytic uremic syndrome (HUS) in three categories: all patients with clinically suspected TTP-HUS, patients with idiopathic TTP-HUS, and patients with severe ADAMTS-13 deficiency. Methods: Incidence rates were estimated from the Oklahoma TTP-HUS Registry, analyzing all 206 consecutive patients from January 1, 1996 to June 30, 2004 who were treated with plasma exchange for their initial episode of clinically suspected TTP-HUS. ADAMTS-13 activity was measured in 186 (90%) of the 206 patients. Results: The age–sex–race standardized annual incidence rates were 11.29 × 106 (95% CI: 9.70–12.88) for all patients with clinically suspected TTP-HUS; 4.46 × 106 (95% CI: 3.43–5.50) for patients with idiopathic TTP-HUS; and 1.74 × 106 (95% CI: 1.06–2.41) for patients with severe ADAMTS-13 deficiency (<5% activity). In all three categories, the incidence rates were greater for women and for blacks. For patients with severe ADAMTS-13 deficiency, the age–sex standardized incidence rate ratio of blacks to non-blacks was 9.29 (95% CI: 4.33–19.93). Conclusions: Accurate incidence rate estimates for all patients with clinically suspected TTP-HUS, idiopathic TTP-HUS, and TTP associated with severe ADAMTS-13 deficiency have been determined. The greater incidence among women and blacks is comparable with their increased risk for other autoimmune disorders.

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Der diaplazentare Transport von Vitamin K ist kaum messbar, die Muttermilch ist arm an Vitamin K und die intestinale Flora von Neugeborenen produziert praktisch kein Vitamin K. Deshalb weisen gesunde Neugeborene «physiologischerweise» tiefe Vitamin-K-Spiegel auf, was durch Verminderung der Vitamin-K-abhängigen Gerinnungsfaktoren zu schweren Mangelblutungen führen kann. Die klassische Form der Vitamin-K-Mangelblutung tritt mit einer Inzidenz von bis zu 1.5% bis zum 7. Lebenstag auf, die Spätform wird bis zur 12. Lebenswoche bei bis zu 10 von 100000 Neugeborenen festgestellt. Mit einer adäquaten Vitamin-K-Prophylaxe lassen sich Vitamin-K-Mangelblutungen grösstenteils verhindern. Die heute in der Schweiz empfohlene Prophylaxe von 3 oralen Dosen à 2 mg Konakion® MM in der 4. Lebensstunde, am 4. Lebenstag und in der 4. Lebenswoche ist bezüglich unerwünschter Nebenwirkung äusserst sicher, insbesondere besteht kein erhöhtes Krebsrisiko. Angesichts der dramatischen Folgen der häufig intrakraniell lokalisierten Vitamin-K-Mangelblutungen ist sowohl bei medizinischen Fachpersonen als auch bei den Eltern eine möglichst gute Compliance für diese einfache und sichere Prophylaxe wie auch eine entsprechende Aufklärung anzustreben.

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The role of dehydroepiandrosterone-sulfate (DHEA-S) in assessing the integrity of the hypothalamic-pituitary-adrenal (HPA) axis in patients with suspected insufficiency is uncertain.

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Folliculo-stellate cells are a nonendocrine, sustentacular-like complementary population of the anterior pituitary. They currently are considered as functionally and phenotypically heterogeneous, with one subpopulation of folliculo-stellate cells possibly representing resident adenohypophyseal macrophages. We took advantage of a limited T-cell mediated inflammatory reaction selectively involving tumor tissue in three cases of pituitary adenoma (2 prolactin cell adenomas, and 1 null cell adenoma) to test the hypothesis whether some folliculo-stellate cells within inflammatory foci would also assume monocytic/dendritic properties. Immunohistochemical double labeling for S-100 protein and the class II major histocompatibility antigen HLA-DR indeed showed several arborized cells to coexpress both epitopes. These were distributed both amidst adenomatous acini and along intratumoral vessels, and were morphologically undistinguishable from conventional folliculo-stellate cells. On the other hand, markers of follicular dendritic cells (CD21) and Langerhans' cells (CD1a) tested negative. Furthermore, no S-100/HLA-DR coexpressing folliculo-stellate cells were seen in either peritumoral parenchyma of the cases in point nor in control pituitary adenomas lacking inflammatory reaction. These findings suggest that a subset of folliculo-stellate cells may be induced by an appropriate local inflammatory microenvironment to assume a dendritic cell-like immunophenotype recognizable by their coexpression of S-100 protein and HLA-DR. By analogy with HLA-DR expressing cells in well-established extrapituitary inflammatory constellations, we speculate that folliculo-stellate cells with such immunophenotype may actually perform professional antigen presentation. A distinctly uncommon finding in pituitary adenomas, lymphocytic infiltrates may therefore be read as a manifestation of tumoral immunosurveillance.

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Ovariectomy interrupts the regulatory loop in the hypothalamus-pituitary-gonad axis, leading to a several-fold increase in gonadotropin levels. This rise in hormonal secretion may play a causal role in ovariectomy-related urinary incontinence. The purpose of this study was to examine the effect of ovariectomy in bitches on the expression of GnRH- and LH-receptors in the lower urinary tract, and assess the relationship between receptor expression and plasma gonadotropin concentrations. Plasma gonadotropins were measured in 37 client-owned bitches. Biopsies were harvested from the mid-ventral bladder wall in all dogs, and from nine further locations within the lower urinary tract in 17 of the 37 animals. Messenger RNA of the LH and GnRH receptors was quantified using RT-PCR with the TaqMan Universal PCR Master Mix. Gonadotropins were measured with a canine-specific FSH-immunoradiometric assay and LH-radioimmunoassay. The hierarchical mixed ANOVA model using MINITAB, Mann-Whitney U-test, unpaired means comparison and linear regressions using StatView were applied for statistical analyses. Messenger RNA for both receptors was detected in all biopsy samples. Age was negatively correlated to mRNA expression of the LH and the GnRH receptors. A relationship between the mRNA values and the plasma gonadotropin concentrations was not established. Evaluation of results within each of the biopsy locations revealed greater LH-receptor expression in the proximal second quarter of the urethra in spayed bitches than in intact bitches (P=0.0481). Increased mRNA expression of LH receptors in this location could possibly play a role in the decrease in closing pressure of the urethra following ovariectomy.

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Neonates are particularly susceptible to malnutrition due to their limited reserves of micronutrients and their rapid growth. In the present study, we examined the effect of vitamin C deficiency on markers of oxidative stress in plasma, liver and brain of weanling guinea pigs. Vitamin C deficiency caused rapid and significant depletion of ascorbate (P < 0.001), tocopherols (P < 0.001) and glutathione (P < 0.001), and a decrease in superoxide dismutase activity (P = 0.005) in the liver, while protein oxidation was significantly increased (P = 0.011). No changes in lipid oxidation or oxidatively damaged DNA were observed in this tissue. In the brain, the pattern was markedly different. Of the measured antioxidants, only ascorbate was significantly depleted (P < 0.001), but in contrast to the liver, ascorbate oxidation (P = 0.034), lipid oxidation (P < 0.001), DNA oxidation (P = 0.13) and DNA incision repair (P = 0.014) were all increased, while protein oxidation decreased (P = 0.003). The results show that the selective preservation of brain ascorbate and induction of DNA repair in vitamin C-deficient weanling guinea pigs is not sufficient to prevent oxidative damage. Vitamin C deficiency may therefore be particularly adverse during the neonatal period.