610 research outputs found
[Incidence and management of infusion reactions to infliximab in 186 italian patients with rheumatoid arthritis: the Padua experience].
Objective: We report the incidence and treatment of infusion reactions to infliximab, a chimeric monoclonal IgG1 antibody against tumor necrosis factor a, in a large cohort of patients with rheumatoid arthritis. Patients and methods: One hundred eighty six patients with rheumatoid arthritis treated with infliximab for a total of 216.6 patient years were retrospectively evaluated. Patients received 2160 infliximab infusions at the Division of Rheumatology at the University Hospital of Padua from May, 2000 to April, 2004. Specific treatment protocols for initial and subsequent acute infusion reactions were followed and the outcomes documented. Results: The overall incidence of infusion reactions to infliximab was 0.8% (19 out of 2160 of infusions), affecting 10.2% of patients (19 out of 186). Mild, moderate, or severe acute reactions occurred in 0.1% (3 of 2160), 0.6% (13 of 2160), and 0.04% (1 of 2160) of infliximab infusions, respectively. Delayed infusion reactions occurred in 0.09% (2 of 2160) of infusions. Use of specific treatment protocols resulted in rapid resolution of all acute reactions to infliximab. With a prophylaxis protocol, all patients who experienced an initial mild acute reaction were able to receive additional infusions. Conclusions: Using appropriate treatment protocols, infliximab infusion reactions were effectively treated and prevented in patients with mild acute reactions upon retreatment. In the case of moderate to severe infusion reactions, the risks and the benefits of the continuation of infliximab therapy need to be carefully considered
Imaging in major salivary gland diseases
Most of the salivary glands diseases are characterized only by a few distinct clinical patterns. Medical history and clinical examination are still considered of great relevance. However, in order to obtaine a definite diagnosis, imaging techniques are required in most of the cases. Salivary glands ultrasonography (US) is the technique to be used as the first because US can easily differentiate calculosis, inflammatory diseases and tumors. Sonography is also frequently needed to perform needle aspiration or biopsy (FNAC). Sialography should be used essentially for assessing chronic sialoadenitis as well as Sjogren's syndrome. At present, Magnetic Resonance sialography should be preferred because of the greater sensibility in diagnosing inflammatory diseases of the salivary glands. It allows to evaluate both intraglandular oedema and nodules, so that incannulation of the salivary duct is not required. Computer Tomography (CT) and Magnetic Resonance imaging (MR) are useful when neoplasm are suspected, particularly if deep areas of the gland, which cannot be visualized by US, are involved. Sequential scintigraphy is currently employed for assessing the functional status of all the 4 major salivary glands and evaluating the chronic evolution of glandular damage
Interaction of Cisplatin with a CCHC Zinc Finger Motif
The interaction between cisplatin and an 18-residue CCHC zinc finger motif derived from a retroviral nucleocapsid protein
(PyrZf18) has been studied using UVâvisible, CD and 1H NMR spectroscopies and ESI-MS spectrometry.
Cisplatin irreversibly blocks the cysteine zinc binding groups in the free peptide and is able to slowly eject zinc from the
zincâpeptide complex. The observed end product of the reaction with cisplatin is a complex in which only one ammonia
molecule is coordinated to platinum. After an initial binding with two cysteine residues and the formation of the (PyrZf18)â
platinumâ(NH3)2 complex, a release of one ammonia molecule occurs because of trans-labilization, and the third cysteine is
coordinated, leading to a mixture of isomers and/or conformers of the (PyrZf18)âplatinumâNH3 complex. The results are discussed
with respect to the potential antiretroviral activity of platinum(II) compounds and to the possible interaction of cisplatin
with the cellular nucleic acid binding proteins
Live-cell topology assessment of URG7, MRP6âââ and SP-C using glycosylatable green fluorescent protein in mammalian cells.
Experimental tools to determine membrane topology of a protein are rather limited in higher eukaryotic organisms. Here, we report the use of glycosylatable GFP (gGFP) as a sensitive and versatile membranetopology reporter in mammalian cells. gGFP selectively loses its fluorescence upon N-linked glycosylationin the ER lumen. Thus, positive fluorescence signal assigns location of gGFP to the cytosol whereas nofluorescence signal and a glycosylated status of gGFP map the location of gGFP to the ER lumen. By usingmammalian gGFP, the membrane topology of disease-associated membrane proteins, URG7, MRP6102,SP-C(Val) and SP-C(Leu) was confirmed. URG7 is partially targeted to the ER, and inserted in Cinform.MRP6102and SP-C(Leu/Val) are inserted into the membrane in Coutform. A minor population of untarget-ed SP-C is removed by proteasome dependent quality control system
Characterization of a Functional NTPDase in the Endoplasmic Reticulum of Rat Submandibular Salivary Gland
Nucleotidase activity and Ca-uptake were characterized in endoplasmic reticulum (ER) enriched rat submandibular gland (SMG) microsomal preparations. (i) Ca-uptake had characteristics of an ER Ca-ATPase. (ii) Nucleotidase activity was equally stimulated by calcium, magnesium and manganese, but with different Km values. (iii) Specific inhibitors of P-type Ca-ATPases were ineffective on nucleotidase activity, demonstrating that this activity was not related to calcium uptake and did not correspond to classical Ca2+ pumps. (iv) ATP and UTP were more efficient substrates, whereas ADP and UDP were hydrolyzed at significantly slower rate. (v) Nucleotidase activity was sensitive to mild detergent solubilization and insensitive to ionophore addition. (vi) Nucleotidase activity was strongly inhibited by suramin, a nucleoside triphosphate diphosphohydrolase (NTPDase) inhibitor. (vii) Nucleotidase activity exponentially diminished as function of time. All these observations are consistent with a NTPDase identity. The presence of a NTPDase was demonstrated by immunohistochemistry in rat SMG. Immunoreactivity was stronger in ductal cells than in mucous and serous acini. Although this enzyme was observed in the plasma membrane, colocalization with the ER marker calnexin revealed a specific subcellular localization in this organelle of all three types of cell. The putative function of this NTPDase activity in salivary glands is discussed.Fil: Ostuni, M. A.. Inserm; Francia. UniversitĂ© Paris; Francia. Universidad de Buenos Aires. Facultad de OdontologĂa; ArgentinaFil: Egido, P.. Universidad de Buenos Aires. Facultad de OdontologĂa; ArgentinaFil: Peranzi, G.. Inserm; Francia. UniversitĂ© Paris; FranciaFil: Alonso, Guillermo Luis. Universidad de Buenos Aires. Facultad de OdontologĂa; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Lacapere, J. J.. Inserm; Francia. UniversitĂ© Paris; FranciaFil: Gonzalez, D. A.. Inserm; Francia. UniversitĂ© Paris; Franci
Phytochemical profile, antioxidant and antidiabetic activities of Adansonia digitata L. (baobab) from Mali, as source of health-promoting compounds
Background: Adansonia digitata L. (Malvaceae), also known as baobab, is a tree attracting recent interest especially due to the high nutritional value of the fruit pulp. However, few studies are reported on the secondary metabolite content, showing high variability due to geographic region. Methods: In this study, the chemical profiles of Malian commercial baobab fruits and leaves, focused on phenolic content, were investigated by HPLC coupled with a photodiode array (PDA)/UV and an electrospray ionization (ESI) mass spectrometer (MS) and gas chromatography (GC)/MS. In addition, the extracts of fruit pulps obtained from three different markets (Fruits 1, 2, and 3) were evaluated for their total phenolic content (TPC), antioxidant activity and α-glucosidase inhibition. Results: Baobab fruit pulps were found to be rich in procyanidins and flavonol glycosides, with tiliroside as the major constituent. The baobab leaves showed a similar profile respect to the fruits, but with more detected phenolics. All fruit pulp extracts exerted antioxidant activity (highest for Fruit 3) and higher α-glucosidase inhibition than acarbose used as standard. Conclusions: This study confirmed the variability of baobab with different origins and indicated Malian species baobab as promising source of health-promoting substances
New insights on the functional role of URG7 in the cellular response to ER stress.
BACKGROUND INFORMATION:
Up-regulated Gene clone 7 (URG7) is an ER resident protein, whose expression is upregulated in the presence of hepatitis B virus X antigen (HBxAg) during HBV infection. In virus-infected hepatocytes, URG7 shows an anti-apoptotic activity due to the PI3K/AKT signaling activation, does not seem to have tumorigenic properties, but it appears to promote the development and progression of fibrosis. However, the molecular mechanisms underlying URG7 activity remain largely unknown.
RESULTS:
To shed light on URG7 activity, we first analyzed its interactome in HepG2 transfected cells: this analysis suggests that URG7 could have a role in affecting protein synthesis, folding and promoting proteins degradation. Moreover, keeping into account its subcellular localization in the ER and that several viral infections give rise to ER stress, a panel of experiments was performed to evaluate a putative role of URG7 in ER stress. Our main results demonstrate that in ER stressed cells URG7 is able to modulate the expression of Unfolded Protein Response (UPR) markers toward survival outcomes, upregulating GRP78 protein and downregulating the pro-apoptotic protein CHOP. Furthermore, URG7 reduces the ER stress by decreasing the amount of unfolded proteins, by increasing both the total protein ubiquitination and the AKT activation and reducing caspase 3 activation.
CONCLUSIONS:
All together these data suggest that URG7 plays a pivotal role as a reliever of ER stress-induced apoptosis.
SIGNIFICANCE:
This is the first characterization of URG7 activity under ER stress conditions. The results presented here will help to hypothesize new strategies to counteract the antiapoptotic activity of URG7 in the context of the viral infection. This article is protected by copyright. All rights reserved
Human VDAC pseudogenes: an emerging role for VDAC1P8 pseudogene in acute myeloid leukemia
Background Voltage-dependent anion selective channels (VDACs) are the most abundant mitochondrial outer
membrane proteins, encoded in mammals by three genes, VDAC1, 2 and 3, mostly ubiquitously expressed. As âmitochondrial
gatekeepersâ, VDACs control organelle and cell metabolism and are involved in many diseases. Despite
the presence of numerous VDAC pseudogenes in the human genome, their significance and possible role in VDAC
protein expression has not yet been considered.
Results We investigated the relevance of processed pseudogenes of human VDAC genes, both in physiological and
in pathological contexts. Using high-throughput tools and querying many genomic and transcriptomic databases,
we show that some VDAC pseudogenes are transcribed in specific tissues and pathological contexts. The obtained
experimental data confirm an association of the VDAC1P8 pseudogene with acute myeloid leukemia (AML).
Conclusions Our in-silico comparative analysis between the VDAC1 gene and its VDAC1P8 pseudogene, together
with experimental data produced in AML cellular models, indicate a specific over-expression of the VDAC1P8 pseudogene
in AML, correlated with a downregulation of the parental VDAC1 gene.
Keywords Pseudogene, Voltage-dependent anion selective channels (VDAC
New Insight on the Bioactivity of Solanum aethiopicum Linn. Growing in Basilicata Region (Italy): Phytochemical Characterization, Liposomal Incorporation, and Antioxidant Effects
Food extractâs biological effect and its improvement using nanotechnologies is one of the challenges of the last and the future decades; for this reason, the antioxidant effect of scarlet eggplant extract liposomal incorporation was investigated. Scarlet eggplant (Solanum aethiopicum L.) is a member of the Solanaceae family, and it is one of the most consumed vegetables in tropical Africa and south of Italy. This study investigated the antioxidant activity and the phytochemical composition of S. aethiopicum grown in the Basilicata Region for the first time. The whole fruit, peel, and pulp were subjected to ethanolic exhaustive maceration extraction, and all extracts were investigated. The HPLC-DAD analysis revealed the presence of ten phenolic compounds, including hydroxycinnamic acids, flavanones, flavanols, and four carotenoids (one xanthophyll and three carotenes). The peel extract was the most promising, active, and the richest in specialized metabolites; hence, it was tested on HepG2 cell lines and incorporated into liposomes. The nanoincorporation enhanced the peel extractâs antioxidant activity, resulting in a reduction of the concentration used. Furthermore, the extract improved the expression of endogenous antioxidants, such as ABCG2, CAT, and NQO1, presumably through the Nrf2 pathway
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