436,526 research outputs found
Thigh echymosis in a newborn
Background and aim: Protein C is one of the important components in haemostasis system and its deficiency could increase the risk of thromboembolic events. This deficiency is seen in 0.2% of the general population. In this case report we present a 3-day old neonate with an echymosis in her left thigh. Case presentation: A female neonate was visited regards to an echymotic lesion in her left thigh and a lighter one in the right which was present at birth. In her laboratory tests, protein C reported 17% while her parents had normal level. She was treated with antithrombotics and level of protein C elevated to 73% at discharge. Conclusion: Clinical manifestations of protein C deficiency could be severe and life threatening, so quick and careful management is needed
COA6 facilitates cytochrome c oxidase biogenesis as thiol-reductase for copper metallochaperones in mitochondria.
The mitochondrial cytochrome c oxidase, the terminal enzyme of the respiratory chain, contains heme and copper centers for electron transfer. The conserved COX2 subunit contains the CuA site, a binuclear copper center. The copper chaperones SCO1, SCO2, and COA6 are required for CuA center formation. Loss of function of these chaperones and the concomitant cytochrome c oxidase deficiency cause severe human disorders. Here we analyzed the molecular function of COA6 and the consequences of COA6 deficiency for mitochondria. Our analyses show that loss of COA6 causes combined complex I and complex IV deficiency and impacts membrane potential driven protein transport across the inner membrane. We demonstrate that COA6 acts as a thiol-reductase to reduce disulphide bridges of critical cysteine residues in SCO1 and SCO2. Cysteines within the CX3CXNH domain of SCO2 mediate its interaction with COA6 but are dispensable for SCO2-SCO1 interaction. Our analyses define COA6 as thiol-reductase, which is essential for CuA biogenesis
A Case Report of Protein C Deficiency in a Neonate with Purpura Fulminans and Bilateral Cataract
Protein C is a vitamin K dependent glycoprotein. Protein C deficiency is a rare genetic
disorder and its major sites of involvement are skin, eyes, lungs, central nervous system, and
kidneys. This article presents a case of neonatal protein C deficiency with severe purpura
fulminans and bilateral cataracts. He was initially treated with fresh-frozen plasma and then
followed by warfarin. All necrotic skin lesions improved with treatment. He was the first child
of his parents who were asymptomatic for protein C deficiency. We also reviewed literatures
about coexistence of cataracts and protein C deficiency.
Key words: Protein C Deficiency; Purpura Fulminans; Bilateral Catarac
Role of G{alpha}12 and G{alpha}13 as Novel Switches for the Activity of Nrf2, a Key Antioxidative Transcription Factor
G{alpha}12 and G{alpha}13 function as molecular regulators responding to extracellular stimuli. NF-E2-related factor 2 (Nrf2) is involved in a protective adaptive response to oxidative stress. This study investigated the regulation of Nrf2 by G{alpha}12 and G{alpha}13. A deficiency of G{alpha}12, but not of G{alpha}13, enhanced Nrf2 activity and target gene transactivation in embryo fibroblasts. In mice, G{alpha}12 knockout activated Nrf2 and thereby facilitated heme catabolism to bilirubin and its glucuronosyl conjugations. An oligonucleotide microarray demonstrated the transactivation of Nrf2 target genes by G{alpha}12 gene knockout. G{alpha}12 deficiency reduced Jun N-terminal protein kinase (JNK)-dependent Nrf2 ubiquitination required for proteasomal degradation, and so did G{alpha}13 deficiency. The absence of G{alpha}12, but not of G{alpha}13, increased protein kinase C {delta} (PKC {delta}) activation and the PKC {delta}-mediated serine phosphorylation of Nrf2. G{alpha}13 gene knockout or knockdown abrogated the Nrf2 phosphorylation induced by G{alpha}12 deficiency, suggesting that relief from G{alpha}12 repression leads to the G{alpha}13-mediated activation of Nrf2. Constitutive activation of G{alpha}13 promoted Nrf2 activity and target gene induction via Rho-mediated PKC {delta} activation, corroborating positive regulation by G{alpha}13. In summary, G{alpha}12 and G{alpha}13 transmit a JNK-dependent signal for Nrf2 ubiquitination, whereas G{alpha}13 regulates Rho-PKC {delta}-mediated Nrf2 phosphorylation, which is negatively balanced by G{alpha}12
The effect of maternal iron deficiency on zinc and copper levels and on genes of zinc and copper metabolism during pregnancy in the rat
Fe deficiency is relatively common in pregnancy and has both short- and long-term consequences. However, little is known about the effect on the metabolism of other micronutrients. A total of fifty-four female rats were fed control (50 mg Fe/kg) or Fe-deficient diets (7·5 mg/kg) before and during pregnancy. Maternal liver, placenta and fetal liver were collected at day 21 of pregnancy for Cu and Zn analysis and to measure expression of the major genes of Cu and Zn metabolism. Cu levels increased in the maternal liver (P=0·002) and placenta (P=0·018) of Fe-deficient rats. Zn increased (P<0·0001) and Cu decreased (P=0·006) in the fetal liver. Hepatic expression of the Cu chaperones antioxidant 1 Cu chaperone (P=0·042) and cytochrome c oxidase Cu chaperone (COX17, P=0·020) decreased in the Fe-deficient dams, while the expression of the genes of Zn metabolism was unaltered. In the placenta, Fe deficiency reduced the expression of the chaperone for superoxide dismutase 1, Cu chaperone for superoxide dismutase (P=0·030), ceruloplasmin (P=0·042) and Zn transport genes, ZRT/IRT-like protein 4 (ZIP4, P=0·047) and Zn transporter 1 (ZnT1, P=0·012). In fetal liver, Fe deficiency increased COX17 (P=0·020), ZRT/IRT-like protein 14 (P=0·036) and ZnT1 (P=0·0003) and decreased ZIP4 (P=0·004). The results demonstrate that Fe deficiency during pregnancy has opposite effects on Cu and Zn levels in the fetal liver. This may, in turn, alter metabolism of these nutrients, with consequences for development in the fetus and the neonate.</p
Haemostatic and fibrinolytic changes in obese subjects undergoing bariatric surgery: the effect of different surgical procedures.
Background
Little is known about effects of different bariatric surgery procedures on haemostatic and fibrinolytic parameters.
Material and methods
Consecutive obese subjects undergoing gastric bypass (GBP) or sleeve gastrectomy (SG) were enrolled. In all patients, levels of haemostatic factors (FII, FVII, FVIII, FIX, FX, vWF, fibrinogen), fibrinolytic variables (PAI-1, t-PA and D-dimer) and natural anticoagulants (AT, protein C and protein S) were evaluated before and 2 months after surgery.
Results
A total of 77 GBP and 79 SG subjects completed the study. At baseline no difference in coagulation parameters was found between the two groups. After both GBP and SG, subjects showed significant changes in haemostatic and fibrinolytic variables and in natural anticoagulant levels. The Δ% changes in FVII, FVIII, FIX, vWF, fibrinogen, D-dimer, protein C and protein S levels were significantly higher in subjects who underwent GBP than in those who underwent SG. Multivariate analysis confirmed that GBP was a predictor of higher Δ% changes in FVII (β=0.268, p=0.010), protein C (β=0.274, p=0.003) and protein S (β=0.297, p<0.001), but not in all the other variables. Following coagulation factor reduction, 31 subjects (25.9% of GBP and 13.9% of SG; p=0.044) showed overt FVII deficiency; protein C deficiency was reported by 34 subjects (32.5% of GBP vs 11.4% of SG, p=0.033) and protein S deficiency by 39 (37.6% of GBP vs 12.6% of SG, p=0.009). Multivariate analyses showed that GBP was associated with an increased risk of deficiency of FVII (OR: 3.64; 95% CI: 1.73–7.64, p=0.001), protein C (OR: 4.319; 95% CI: 1.33–13.9, p=0.015) and protein S (OR: 5.50; 95% CI: 1.71–17.7, p=0.004).
Discussion
GBP is associated with an increased risk of post-operative deficiency in some vitamin K-dependent coagulation factors. Whereas such deficiency is too weak to cause bleeding, it is significant enough to increase the risk of thrombosis
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Novel pathogenic COX20 variants causing dysarthria, ataxia, and sensory neuropathy.
COX20/FAM36A encodes a mitochondrial complex IV assembly factor important for COX2 activation. Only one homozygous COX20 missense mutation has been previously described in two separate consanguineous families. We report four subjects with features that include childhood hypotonia, areflexia, ataxia, dysarthria, dystonia, and sensory neuropathy. Exome sequencing in all four subjects identified the same novel COX20 variants. One variant affected the splice donor site of intron-one (c.41A>G), while the other variant (c.157+3G>C) affected the splice donor site of intron-two. cDNA and protein analysis indicated that no full-length cDNA or protein was generated. These subjects expand the phenotype associated with COX20 deficiency
Novel mutation in addition to functional TMPRSS6 gene polymorphisms originate an IRIDA-like phenotype in an African child
Iron-refractory iron deficiency anemia (IRIDA) is a rare autosomal recessive anemia often unresponsive to oral iron intake and partially responsive to parenteral iron treatment. The disease originates from mutations in TMPRSS6 gene, encoding Matriptase 2, a transmembrane serine protease that plays an essential role in down-regulating hepcidin. Once TMPRSS6 is mutated, the corresponding protein is absent or inactive at the hepatocyte membrane leading to uncontrolled high levels of hepcidin and impaired iron absorption.
This study aimed to investigate a 4-year-old boy of sub-Saharan ancestry (Mozambique/Angola), presenting with microcytic hypochromic anemia, low transferrin saturation, normal ferritin, and having a partial response to intravenous iron treatment. He is a -α3.7-thalassemia carrier. TMPRSS6 was screened for variants by Next-Generation Sequencing using Nextera XT libraries in a MiSeq platform (Illumina). Genetic variants found were validated by Sanger sequencing. In silico analyses were performed in HSF, SIFT, Poly-Phen2 and Missense3D softwares.
A novel missense mutation (c.871G>A) was found in heterozygosity, in TMPRSS6 exon 8. In silico analysis indicates the conserved amino acid change (G291S) may be damaging to the protein stability. Due to its location in the CUB1 domain, it may also affect the enzyme activation and substrate recognition. Additionally, 3 SNPs previously associated with a greater risk of developing iron deficiency anemia (K253E, V736A and Y739Y) were also identified in TMPRSS6.
Although IRIDA is known as an autosomal recessive disease, we conclude that, in this case, the result of a digenic inheritance of the novel damaging mutation (c.871G>A; G291S) and the 3 common modulating SNPs in the same gene and a co-inheritance of the α-thalassemia HBA deletion may lead to an IRIDA-like phenotype. Further functional studies of the mutated protein as well as family studies should be conducted.This work was partially supported by INSA_2013DGH910 and GenomePT (POCI-01-0145-FEDER-022184).info:eu-repo/semantics/publishedVersio
Altered expression of Alzheimer's disease-related proteins in male hypogonadal mice
Age-related depletion of estrogens and androgens is associated with an increase in Alzheimer's disease (AD) brain pathology and diminished cognitive function. Here we investigated AD-associated molecular and cellular changes in brains of aged hypogonadal (hpg) male and female mice. hpg Mice have a spontaneous, inactivating genetic mutation in the GnRH gene resulting in lifelong deficiency of gonadotropins and gonadal sex hormones. Western blot analysis revealed low levels of amyloid precursor protein and high levels of presenilin 1, amyloid precursor protein C-terminal fragment, and beta-amyloid 42 in brains of aged male, but not female, hpg mice. Changes were confined to the hippocampus and were not evident in the cerebellum or other brain tissues. Male hpg mice tended to have lower levels of IL-1 beta protein than male littermate controls. Immunohistochemical staining of the basal forebrain revealed that male hpg mice had lower choline acetyltransferase levels per neuron compared with controls. These AD-like changes specific to male hpg mice supports a link between androgen depletion and the development of AD pathology
Effect of Calcium Deficiency on Growth and Leaf Acid Soluble Proteins of Tomato
The effects of temporary Ca (Ca) calcium deficiency lasting 2, 3, 4 or 5 d were
investigated on tomato plants at the 6-leaf stage, grown hydroponically under
controlled conditions. With 2, 3 or 4 d of Ca deficiency, the dry weight of the
tomato leaves, shoots or roots was not different from control. A significant
decrease in tomato growth, of up to 70%, appeared on the fifth day. Some visual
symptoms were observed on the tomato leaves. The phenomenon concerned was
an irreversible mechanism that led to plant death after 12 d, even when Ca was
added to the root medium after 2, 3, 4 or 5 d. This is the first report of such a
rapid and drastic effect of an essential macronutrient. Moreover, Ca content in
leaves during root deprivation showed a decrease in all plants, related to a
remobilization toward the apex. Ca could be considered as a partly mobile
element: the observation of the youngest leaf limbs by transmission electronic
microscopy after 4 d of treatment showed disorganized tissues in a necrotic
zone, due to wall impairment related to C deficiency. During temporary Ca
deficiency, acid soluble proteins were analyzed in leaves (SDS PAGE
electrophoresis / Maldi-TOF). After 4 d of Ca deficiency, protein induction in
young leaves was revealed. Three proteins were identified as pathogenesis
related proteins (PR-1, PR-3, PR-7) and a threonine deaminase precursor was
also found. It was also the first time that pathogenesis related (PR) protein
appearance has been shown to be related to Ca deficiency. The PR proteins are
generally elicited by pathogen attack. This phenomenon seems to be calcium
dependent because other mineral stresses, such as potassium (K) deficiency or
sodium (Na) excess, did not reveal acid soluble protein changes. The
retranslocation of Ca to young tissue could entail eliciting effects via wall
fragments leading to a plant response similar to the response to pathogen attac
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