689 research outputs found
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 UV–visible, 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
zinc–peptide 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)–
platinum–(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)–platinum–NH3 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
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. Université Paris; Francia. Universidad de Buenos Aires. Facultad de Odontología; ArgentinaFil: Egido, P.. Universidad de Buenos Aires. Facultad de Odontología; ArgentinaFil: Peranzi, G.. Inserm; Francia. Université Paris; FranciaFil: Alonso, Guillermo Luis. Universidad de Buenos Aires. Facultad de Odontología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lacapere, J. J.. Inserm; Francia. Université Paris; FranciaFil: Gonzalez, D. A.. Inserm; Francia. Université Paris; Franci
Phytochemical profile of capsicum annuum l. Cv senise, incorporation into liposomes, and evaluation of cellular antioxidant activity
Overproduction of oxidants in the human body is responsible for oxidative stress, which is associated with several diseases. High intake of vegetables and fruits can reduce the risk of chronic diseases, as they are sources of bioactive compounds capable of contrasting the free radical effects involved in cancer, obesity, diabetes, and neurodegenerative and cardiovascular diseases. Capsicum annuum L. cv Senise is a sweet pepper that is grown in the Basilicata region (Italy). It is an important source of polyphenols, carotenoids, and capsinoids and can play a key role in human health. In this study, an ethanol extract was obtained from C. annuum dried peppers and the analysis of the phytochemical composition was performed by LC-ESI/LTQ Orbitrap/MS. The extract was incorporated into liposomes, which showed small size (~80 nm), good homogeneity, negative surface charge, and good stability in storage. The biological activity of the extract was evaluated in the human hepatoma (HepG2) cell line, used as model cells. The extract showed no cytotoxic activity and reduced the intracellular reactive oxygen species (ROS) level in stressed cells. The antioxidant activity was further improved when the extract was loaded into liposomes. Moreover, the extract promoted the expression of endogenous antioxidants, such as catalase, superoxide dismutase, and glutathione peroxidase through the Nrf-2 pathway evaluated by RT-PCR
A Pilot Study on Biochemical Profile of Follicular Fluid in Breast Cancer Patients
Breast cancer (BC) is the most common type of cancer among women in almost all countries worldwide and is one of the oncological pathologies for which is indicated fertility preservation, a type of procedure used to help keep a person's ability to have children. Follicular fluid (FF) is a major component of oocyte microenvironment, which is involved in oocyte growth, follicular maturation, and in communication between germ and somatic cells; furthermore, it accumulates all metabolites during oocytes growth. To obtain information about changes on fertility due to cancer, we aimed at investigating potential biomarkers to discriminate between FF samples obtained from 16 BC patients and 10 healthy women undergoing in vitro fertilization treatments. An NMR-based metabolomics approach was performed to investigate the FF metabolic profiles; ELISA and western blotting assays were used to investigate protein markers of oxidative and inflammatory stress, which are processes closely related to cancer. Our results seem to suggest that FFs of BC women display some significant metabolic alterations in comparison to healthy controls, and these variations are also related with tumor staging
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
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
Genomic and personalized medicine approaches for substance use disorders (SUDs) looking at genome-wide association studies
Drug addiction, or substance use disorder (SUD), is a chronic, relapsing disorder in which compulsive drug-seeking and drug-taking behaviour persist despite serious negative consequences. Drug abuse represents a problem that deserves great attention from a social point of view, and focuses on the importance of genetic studies to help in understanding the genetic basis of addiction and its medical treatment. Despite the complexity of drug addiction disorders, and the high number of environmental variables playing a role in the onset, recurrence, and duration of the symptoms, several studies have highlighted the non-negligible role of genetics, as demonstrated by heritability and genome-wide association studies. A correlation between the relative risk of addiction to specific substances and heritability has been recently observed, suggesting that neurobiological mechanisms may be, at least in part, inherited. All these observations point towards a scenario where the core neurobiological factors of addiction, involving the reward system, impulsivity, compulsivity, stress, and anxiety response, are transmitted, and therefore, genes and mutations underlying their variation might be detected. In the last few years, the development of new and more efficient sequencing technologies has paved the way for large-scale studies in searching for genetic and epigenetic factors affecting drug addiction disorders and their treatments. These studies have been crucial to pinpoint single nucleotide polymorphisms (SNPs) in genes that affect the reaction to medical treatments. This is critically important to identify pharmacogenomic approaches for substance use disorder, such as OPRM1 SNPs and methadone required doses for maintenance treatment (MMT). Nevertheless, despite the promising results obtained by genome-wide association and pharmacogenomic studies, specific studies related to population genetics diversity are lacking, undermining the overall applicability of the preliminary findings, and thus potentially affecting the portability and the accuracy of the genetic studies. In this review, focusing on cannabis, cocaine and heroin use, we report the state-of-the-art genomics and pharmacogenomics of SUDs, and the possible future perspectives related to medical treatment response in people that ask for assistance in solving drug-related problems
Standardization of a simple method to study whole saliva: clinical use in different pathologies.
En este trabajo se describe la normatización de un método para determinar flujo salival en humanos utilizando saliva total obtenida del piso de la boca mediante un eyector dental descartable y una bomba de vacío (equipo dental). En este estudio se evaluaron 40 sujetos sanos de ambos sexos y 51 pacientes con diversas patologías (Síndrome de Sjögren, Disfunción Tiroidea, Diabetes Mellitus). Se demostró que el flujo salival basal era estable a partir de los primeros 5 minutos de colocado el eyector en la cavidad bucal. No se encontraron diferencias significativas en el flujo salival basal comparando los sexos, siendo independiente de la intensidad del vacío efectuado por la bomba. El flujo de saliva total estimulada fue determinado durante 3 minutos, luego de los primeros 5 minutos de colocado el eyector en la boca. El estímulo se efectuó adosando en la cara dorsal de la lengua discos de papel absorbente, embebidos en ácido cítrico al 2 %. El uso de este método en pacientes con Síndrome de Sjögren confirmó la reducción del flujo salival respecto a los sujetos sanos. Los pacientes hipotiroideos y con neuropatía diabética demostraron disminución del flujo salival.The present study describes a methodology to assess the salivary flow rate in humans. Whole saliva was obtained from the floor of the mouth with a plastic dental ejector and a vacuum pump. Forty healthy subjects of both sexes and 51 patients with different pathologies (Sjögren Syndrome, Thyroid Dysfunction, Diabetes Mellitus) were included in the study. It was demonstrated that basal salivary flow rate was stable five minutes after the insertion of the oral ejector. Salivary flow rate did not show significant differences between sexes and was independent of the negative pressure level of the vacuum pump. Stimulated salivary flow rate was quantified over a period of 3 minutes, starting 5 minutes after the introduction of the oral device. The stimulus was paper filter disks soaked in citric acid (2%) placed on the tongue dorsum. The use of this method confirmed the reduction of salivary flow rate in patients with Sjögren Syndrome. In addition, a significant reduction in salivary flow rate was observed in patients with primary thyroid insufficiency and peripheral neuropathy secondary to Diabetes Mellitus.Fil: Tumilasci, Omar Rene. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Universidad de Buenos Aires. Facultad de Odontología. Cátedra de Fisiología; ArgentinaFil: Cardoso, Estela M. del Luján. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Médicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Médicas; ArgentinaFil: Contreras, Liliana Noemí. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Médicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Médicas; ArgentinaFil: Belforte, Juan Emilio. Universidad de Buenos Aires. Facultad de Odontología. Cátedra de Fisiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Arregger, Alejandro Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Médicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Médicas; ArgentinaFil: Ostuni, Mariano A.. Inserm; Franci
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