39 results on '"Vargas DM"'
Search Results
2. Plasticity and redundancy among AMA-RON pairs ensure host cell entry of Toxoplasma parasites
- Author
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Lamarque MH Roques M Kong-Hap M Tonkin ML Rugarabamu G Marq JB Penarete-Vargas DM Boulanger M
- Subjects
parasitic diseases - Abstract
Malaria and toxoplasmosis are infectious diseases caused by the apicomplexan parasites Plasmodium and Toxoplasma gondii respectively. These parasites have developed an invasion mechanism involving the formation of a moving junction (MJ) that anchors the parasite to the host cell and forms a ring through which the parasite penetrates. The composition and the assembly of the MJ and in particular the presence of protein AMA1 and its interaction with protein RON2 at the MJ have been the subject of intense controversy. Here using reverse genetics we show that AMA1 a vaccine candidate interacts with RON2 to maintain the MJ structural integrity in T. gondii and is subsequently required for parasite internalization. Moreover we show that disruption of the AMA1 gene results in upregulation of AMA1 and RON2 homologues that cooperate to support residual invasion. Our study highlights a considerable complexity and molecular plasticity in the architecture of the MJ.
- Published
- 2014
3. Characterization of morphological and biological aspects of venomous caterpillars of the genus Lonomia Walker (Lepidoptera: Saturniidae) in Colombia.
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Toro-Vargas DM, González C, Rougerie R, and Amarillo-Suárez AR
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- Humans, Male, Adult, Animals, Colombia, Larva genetics, Lepidoptera genetics, Arthropod Venoms, Manduca, Moths
- Abstract
The genus Lonomia Walker, 1855 (Lepidoptera: Saturniidae) is of particular interest to the medical community, since the scoli of these caterpillars harbor a venom that induces hemorrhaging in humans. In Colombia, deadly encounters with Lonomia achelous (Cramer, 1777), have been reported since 2000. There is little information on the main biological and ecological aspects of this genus to help better understand and develop prevention strategies. This study aimed to describe morphological and biological aspects (especially of immature stages) of four recently reported species of Lonomia in Colombia that pose a risk to humans. We collected caterpillars and adults from five localities and reared them under laboratory conditions. Specimens were identified using DNA barcoding and dissection of adult male genitalia. We provided the first description, to our knowledge, of part of the life cycles of Lonomia casanarensis Brechlin, 2017 and Lonomia orientoandensis Brechlin & Meister, 2011 and the complete life cycles of Lonomia columbiana Lemaire, 1972 and Lonomia orientocordillera Brechlin, Käch & Meister, 2013. We also present the first records of the parasitoids of L. orientocordillera, and L. casanarensis and new host plants. This information will guide not only their morphological recognition and the identification of their parasitoids and hosts, but also will guide rearing methods of these and other Lonomia species in new studies to prevent incidents with humans and create specific antivenoms., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Toro-Vargas et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)
- Published
- 2023
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4. A comparative study of COVID-19 transcriptional signatures between clinical samples and preclinical cell models in the search for disease master regulators and drug repositioning candidates.
- Author
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Chapola H, de Bastiani MA, Duarte MM, Freitas MB, Schuster JS, de Vargas DM, and Klamt F
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- Humans, Drug Repositioning methods, Gene Expression Profiling methods, Lung, TEA Domain Transcription Factors, Transcription Factors genetics, COVID-19
- Abstract
Coronavirus disease 2019 (COVID-19) is an acute viral disease with millions of cases worldwide. Although the number of daily new cases and deaths has been dropping, there is still a need for therapeutic alternatives to deal with severe cases. A promising strategy to prospect new therapeutic candidates is to investigate the regulatory mechanisms involved in COVID-19 progression using integrated transcriptomics approaches. In this work, we aimed to identify COVID-19 Master Regulators (MRs) using a series of publicly available gene expression datasets of lung tissue from patients which developed the severe form of the disease. We were able to identify a set of six potential COVID-19 MRs related to its severe form, namely TAL1, TEAD4, EPAS1, ATOH8, ERG, and ARNTL2. In addition, using the Connectivity Map drug repositioning approach, we identified 52 different drugs which could be used to revert the disease signature, thus being candidates for the design of novel clinical treatments. Furthermore, we compared the identified signature and drugs with the ones obtained from the analysis of nasopharyngeal swab samples from infected patients and preclinical cell models. This comparison showed significant similarities between them, although also revealing some limitations on the overlap between clinical and preclinical data in COVID-19, highlighting the need for careful selection of the best model for each disease stage., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)
- Published
- 2023
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5. Deadly and venomous Lonomia caterpillars are more than the two usual suspects.
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González C, Ballesteros-Mejia L, Díaz-Díaz J, Toro-Vargas DM, Amarillo-Suarez AR, Gey D, León C, Tovar E, Arias M, Rivera N, Buitrago LS, Pinto-Moraes RH, Sano Martins IS, Decaëns T, González MA, Kitching IJ, and Rougerie R
- Subjects
- Animals, Humans, Larva, Hemorrhage, South America, Arthropod Venoms toxicity, Moths
- Abstract
Caterpillars of the Neotropical genus Lonomia (Lepidoptera: Saturniidae) are responsible for some fatal envenomation of humans in South America inducing hemostatic disturbances in patients upon skin contact with the caterpillars' spines. Currently, only two species have been reported to cause hemorrhagic syndromes in humans: Lonomia achelous and Lonomia obliqua. However, species identifications have remained largely unchallenged despite improved knowledge of venom diversity and growing evidence that the taxonomy used over past decades misrepresents and underestimates species diversity. Here, we revisit the taxonomic diversity and distribution of Lonomia species using the most extensive dataset assembled to date, combining DNA barcodes, morphological comparisons, and geographical information. Considering new evidence for seven undescribed species as well as three newly proposed nomenclatural changes, our integrative approach leads to the recognition of 60 species, of which seven are known or strongly suspected to cause severe envenomation in humans. From a newly compiled synthesis of epidemiological data, we also examine the consequences of our results for understanding Lonomia envenomation risks and call for further investigations of other species' venom activities. This is required and necessary to improve alertness in areas at risk, and to define adequate treatment strategies for envenomed patients, including performing species identification and assessing the efficacy of anti-Lonomia serums against a broader diversity of species., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 González et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)
- Published
- 2023
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6. Invasion of Toxoplasma gondii bradyzoites: Molecular dissection of the moving junction proteins and effective vaccination targets.
- Author
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Najm R, Ruivo MTG, Penarete-Vargas DM, Hamie M, Mouveaux T, Gissot M, Boulanger MJ, El Hajj H, and Lebrun M
- Subjects
- Animals, Protozoan Proteins genetics, Protozoan Proteins metabolism, Persistent Infection, Vaccination, Toxoplasma metabolism, Toxoplasmosis metabolism, Parasites metabolism
- Abstract
Toxoplasmosis is a neglected parasitic disease necessitating public health control. Host cell invasion by Toxoplasma occurs at different stages of the parasite's life cycle and is crucial for survival and establishment of infection. In tachyzoites, which are responsible for acute toxoplasmosis, invasion involves the formation of a molecular bridge between the parasite and host cell membranes, referred to as the moving junction (MJ). The MJ is shaped by the assembly of AMA1 and RON2, as part of a complex involving additional RONs. While this essential process is well characterized in tachyzoites, the invasion process remains unexplored in bradyzoites, which form cysts and are responsible for chronic toxoplasmosis and contribute to the dissemination of the parasite between hosts. Here, we show that bradyzoites invade host cells in an MJ-dependent fashion but differ in protein composition from the tachyzoite MJ, relying instead on the paralogs AMA2 and AMA4. Functional characterization of AMA4 reveals its key role for cysts burden during the onset of chronic infection, while being dispensable for the acute phase. Immunizations with AMA1 and AMA4, alone or in complex with their rhoptry neck respective partners RON2 and RON2
L1 , showed that the AMA1-RON2 pair induces strong protection against acute and chronic infection, while the AMA4-RON2L1 complex targets more selectively the chronic form. Our study provides important insights into the molecular players of bradyzoite invasion and indicates that invasion of cyst-forming bradyzoites contributes to cyst burden. Furthermore, we validate AMA-RON complexes as potential vaccine candidates to protect against toxoplasmosis.- Published
- 2023
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7. An apical membrane complex for triggering rhoptry exocytosis and invasion in Toxoplasma.
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Sparvoli D, Delabre J, Penarete-Vargas DM, Kumar Mageswaran S, Tsypin LM, Heckendorn J, Theveny L, Maynadier M, Mendonça Cova M, Berry-Sterkers L, Guérin A, Dubremetz JF, Urbach S, Striepen B, Turkewitz AP, Chang YW, and Lebrun M
- Subjects
- Protozoan Proteins metabolism, Organelles metabolism, Exocytosis, Membrane Proteins metabolism, Host-Parasite Interactions, Toxoplasma genetics, Toxoplasma metabolism
- Abstract
Apicomplexan parasites possess secretory organelles called rhoptries that undergo regulated exocytosis upon contact with the host. This process is essential for the parasitic lifestyle of these pathogens and relies on an exocytic machinery sharing structural features and molecular components with free-living ciliates. However, how the parasites coordinate exocytosis with host interaction is unknown. Here, we performed a Tetrahymena-based transcriptomic screen to uncover novel exocytic factors in Ciliata and conserved in Apicomplexa. We identified membrane-bound proteins, named CRMPs, forming part of a large complex essential for rhoptry secretion and invasion in Toxoplasma. Using cutting-edge imaging tools, including expansion microscopy and cryo-electron tomography, we show that, unlike previously described rhoptry exocytic factors, TgCRMPs are not required for the assembly of the rhoptry secretion machinery and only transiently associate with the exocytic site-prior to the invasion. CRMPs and their partners contain putative host cell-binding domains, and CRMPa shares similarities with GPCR proteins. Collectively our data imply that the CRMP complex acts as a host-molecular sensor to ensure that rhoptry exocytosis occurs when the parasite contacts the host cell., (© 2022 The Authors. Published under the terms of the CC BY 4.0 license.)
- Published
- 2022
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8. Alexithymia in obese adolescents is associated with severe obesity and binge eating behavior.
- Author
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Fanton S, Azevedo LC, and Vargas DM
- Subjects
- Adolescent, Affective Symptoms complications, Affective Symptoms epidemiology, Cross-Sectional Studies, Feeding Behavior, Humans, Psychiatric Status Rating Scales, Binge-Eating Disorder complications, Binge-Eating Disorder epidemiology, Obesity, Morbid, Pediatric Obesity complications, Pediatric Obesity epidemiology
- Abstract
Objective: To study the occurrence of alexithymia in obese adolescents., Methods: Cross-sectional study with 102 obese adolescents. Sociodemographic, clinical, and psychometric data (alexithymia and binge eating) were analyzed The Brazilian version of the Toronto Alexithymia Scale and Binge Eating Scale were used for psychometric data collection. Statistical analysis was performed using the Kolmogorov-Smirnov test, Student's t-test, ANOVA, chi-square, linear regression, and logistic regression. The study was approved by Research Ethics Committee., Results: A 22% occurrence of alexithymia was observed. Considering the category "possible alexithymia", half of the participants presented some alexithymic behavior. Adolescents with alexithymia had higher binge eating scores (alexithymia 16,2 versus possible alexithymia 11,7 versus no alexithymia 8,5; ANOVA p < 0,0005) and three times more binge eating behavior than adolescents with no alexithymia or possible alexithymia (alexithymia 36.4% versus 17.2% possible alexithymia versus 11.8% no alexithymia; chi-square = 6,2, p = 0.04). In simple linear regression, alexithymia scores were positively associated with binge eating scores (r
2 = 0,4; p = 0,002). Binary logistic regression showed a three times higher probability of an adolescent with severe obesity to meet the criteria for alexithymia., Conclusions: There was a 22% occurrence of alexithymia in obese adolescents. It was positively associated with obesity severity and higher binge eating scores, suggesting a relationship between severe obesity, alexithymia, and binge eating behavior., Competing Interests: Conflicts of interest The authors declare no conflicts of interest., (Copyright © 2021 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.)- Published
- 2022
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9. Post-COVID 19 neurological syndrome: Are we facing a neuropsychiatric phenotype?
- Author
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Rubiano-Buitrago JD, Rahiran-Ramírez AF, Peña-Vargas DM, Paez-Rincon LA, and Lozada-Martinez ID
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- Humans, Phenotype, SARS-CoV-2, Syndrome, COVID-19, Nervous System Diseases etiology
- Published
- 2022
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10. Height adjustment reduces occurrence of low bone mineral density in children and adolescents with HIV.
- Author
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Andrade LB, Nogueira TF, and Vargas DM
- Subjects
- Absorptiometry, Photon, Adolescent, Body Height, Child, Cross-Sectional Studies, Humans, Bone Diseases, Metabolic, HIV Infections
- Abstract
Objective: The aim of this study was to quantify the reduction of bone mineral density with and without height adjustment., Methods: A cross-sectional study was performed with 69 Brazilian children and adolescents vertically infected by HIV. Bone mineral density was measured by dual-energy absorptiometry in the lumbar spine. Anthropometric, demographic, and clinical variables were analyzed. A specific calculator was used for height adjustment., Results: The majority of participants (52.2%) were adolescents and did not present with immunological alterations (61%). Reduced bone mineral density (Z-score <-1) was present in 23.2% and low bone mass (Z-score <-2) in 5.8%. After height adjustment, these occurrences decreased to 11.6% and 0%, respectively. Patients with reduced bone mineral density had a higher mean age and lower body mass index than patients with normal bone mineral density., Conclusion: The occurrence of reduced bone mineral density decreased after adjustment for height.
- Published
- 2021
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11. Parkinson's Disease Master Regulators on Substantia Nigra and Frontal Cortex and Their Use for Drug Repositioning.
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Vargas DM, De Bastiani MA, Parsons RB, and Klamt F
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- Gene Expression Profiling, Gene Expression Regulation, Gene Regulatory Networks, Humans, Parkinson Disease genetics, Drug Repositioning, Frontal Lobe pathology, Parkinson Disease drug therapy, Substantia Nigra pathology, Transcription Factors metabolism
- Abstract
Parkinson's disease (PD) is among the most prevalent neurodegenerative diseases. Available evidences support the view of PD as a complex disease, being the outcome of interactions between genetic and environmental factors. In face of diagnosis and therapy challenges, and the elusive PD etiology, the use of alternative methodological approaches for the elucidation of the disease pathophysiological mechanisms and proposal of novel potential therapeutic interventions has become increasingly necessary. In the present study, we first reconstructed the transcriptional regulatory networks (TN), centered on transcription factors (TF), of two brain regions affected in PD, the substantia nigra pars compacta (SNc) and the frontal cortex (FCtx). Then, we used case-control studies data from these regions to identify TFs working as master regulators (MR) of the disease, based on region-specific TNs. Twenty-nine regulatory units enriched with differentially expressed genes were identified for the SNc, and twenty for the FCtx, all of which were considered MR candidates for PD. Three consensus MR candidates were found for SNc and FCtx, namely ATF2, SLC30A9, and ZFP69B. In order to search for novel potential therapeutic interventions, we used these consensus MR candidate signatures as input to the Connectivity Map (CMap), a computational drug repositioning webtool. This analysis resulted in the identification of four drugs that reverse the expression pattern of all three MR consensus simultaneously, benperidol, harmaline, tubocurarine chloride, and vorinostat, thus suggested as novel potential PD therapeutic interventions.
- Published
- 2021
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12. An Alveolata secretory machinery adapted to parasite host cell invasion.
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Aquilini E, Cova MM, Mageswaran SK, Dos Santos Pacheco N, Sparvoli D, Penarete-Vargas DM, Najm R, Graindorge A, Suarez C, Maynadier M, Berry-Sterkers L, Urbach S, Fahy PR, Guérin AN, Striepen B, Dubremetz JF, Chang YW, Turkewitz AP, and Lebrun M
- Subjects
- Alveolata classification, Alveolata ultrastructure, Cell Membrane metabolism, Exocytosis, Host-Parasite Interactions, Humans, Protozoan Proteins genetics, Protozoan Proteins metabolism, Secretory Vesicles metabolism, Alveolata physiology, Organelles metabolism
- Abstract
Apicomplexa are unicellular eukaryotes and obligate intracellular parasites, including Plasmodium (the causative agent of malaria) and Toxoplasma (one of the most widespread zoonotic pathogens). Rhoptries, one of their specialized secretory organelles, undergo regulated exocytosis during invasion
1 . Rhoptry proteins are injected directly into the host cell to support invasion and subversion of host immune function2 . The mechanism by which they are discharged is unclear and appears distinct from those in bacteria, yeast, animals and plants. Here, we show that rhoptry secretion in Apicomplexa shares structural and genetic elements with the exocytic machinery of ciliates, their free-living relatives. Rhoptry exocytosis depends on intramembranous particles in the shape of a rosette embedded into the plasma membrane of the parasite apex. Formation of this rosette requires multiple non-discharge (Nd) proteins conserved and restricted to Ciliata, Dinoflagellata and Apicomplexa that together constitute the superphylum Alveolata. We identified Nd6 at the site of exocytosis in association with an apical vesicle. Sandwiched between the rosette and the tip of the rhoptry, this vesicle appears as a central element of the rhoptry secretion machine. Our results describe a conserved secretion system that was adapted to provide defence for free-living unicellular eukaryotes and host cell injection in intracellular parasites.- Published
- 2021
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13. Alzheimer's disease master regulators analysis: search for potential molecular targets and drug repositioning candidates.
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Vargas DM, De Bastiani MA, Zimmer ER, and Klamt F
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- Alzheimer Disease metabolism, Brain Mapping, Female, Hippocampus pathology, Humans, Male, Alzheimer Disease pathology, Drug Repositioning methods, Gene Expression Regulation physiology, Gene Regulatory Networks, Hippocampus metabolism
- Abstract
Background: Alzheimer's disease (AD) is a multifactorial and complex neuropathology that involves impairment of many intricate molecular mechanisms. Despite recent advances, AD pathophysiological characterization remains incomplete, which hampers the development of effective treatments. In fact, currently, there are no effective pharmacological treatments for AD. Integrative strategies such as transcription regulatory network and master regulator analyses exemplify promising new approaches to study complex diseases and may help in the identification of potential pharmacological targets., Methods: In this study, we used transcription regulatory network and master regulator analyses on transcriptomic data of human hippocampus to identify transcription factors (TFs) that can potentially act as master regulators in AD. All expression profiles were obtained from the Gene Expression Omnibus database using the GEOquery package. A normal hippocampus transcription factor-centered regulatory network was reconstructed using the ARACNe algorithm. Master regulator analysis and two-tail gene set enrichment analysis were employed to evaluate the inferred regulatory units in AD case-control studies. Finally, we used a connectivity map adaptation to prospect new potential therapeutic interventions by drug repurposing., Results: We identified TFs with already reported involvement in AD, such as ATF2 and PARK2, as well as possible new targets for future investigations, such as CNOT7, CSRNP2, SLC30A9, and TSC22D1. Furthermore, Connectivity Map Analysis adaptation suggested the repositioning of six FDA-approved drugs that can potentially modulate master regulator candidate regulatory units (Cefuroxime, Cyproterone, Dydrogesterone, Metrizamide, Trimethadione, and Vorinostat)., Conclusions: Using a transcription factor-centered regulatory network reconstruction we were able to identify several potential molecular targets and six drug candidates for repositioning in AD. Our study provides further support for the use of bioinformatics tools as exploratory strategies in neurodegenerative diseases research, and also provides new perspectives on molecular targets and drug therapies for future investigation and validation in AD.
- Published
- 2018
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14. RA Differentiation Enhances Dopaminergic Features, Changes Redox Parameters, and Increases Dopamine Transporter Dependency in 6-Hydroxydopamine-Induced Neurotoxicity in SH-SY5Y Cells.
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Lopes FM, da Motta LL, De Bastiani MA, Pfaffenseller B, Aguiar BW, de Souza LF, Zanatta G, Vargas DM, Schönhofen P, Londero GF, de Medeiros LM, Freire VN, Dafre AL, Castro MA, Parsons RB, and Klamt F
- Subjects
- Cell Death drug effects, Cells, Cultured, Dithiothreitol pharmacology, Dopamine Plasma Membrane Transport Proteins metabolism, Dopaminergic Neurons metabolism, Humans, Hydrogen Peroxide, Oxidation-Reduction drug effects, Oxidopamine antagonists & inhibitors, Phosphines pharmacology, Antioxidants metabolism, Cell Differentiation drug effects, Dopamine Plasma Membrane Transport Proteins antagonists & inhibitors, Dopaminergic Neurons physiology, Tretinoin pharmacology
- Abstract
Research on Parkinson's disease (PD) and drug development is hampered by the lack of suitable human in vitro models that simply and accurately recreate the disease conditions. To counteract this, many attempts to differentiate cell lines, such as the human SH-SY5Y neuroblastoma, into dopaminergic neurons have been undertaken since they are easier to cultivate when compared with other cellular models. Here, we characterized neuronal features discriminating undifferentiated and retinoic acid (RA)-differentiated SH-SYSY cells and described significant differences between these cell models in 6-hydroxydopamine (6-OHDA) cytotoxicity. In contrast to undifferentiated cells, RA-differentiated SH-SY5Y cells demonstrated low proliferative rate and a pronounced neuronal morphology with high expression of genes related to synapse vesicle cycle, dopamine synthesis/degradation, and of dopamine transporter (DAT). Significant differences between undifferentiated and RA-differentiated SH-SY5Y cells in the overall capacity of antioxidant defenses were found; although RA-differentiated SH-SY5Y cells presented a higher basal antioxidant capacity with high resistance against H
2 O2 insult, they were twofold more sensitive to 6-OHDA. DAT inhibition by 3α-bis-4-fluorophenyl-methoxytropane and dithiothreitol (a cell-permeable thiol-reducing agent) protected RA-differentiated, but not undifferentiated, SH-SY5Y cells from oxidative damage and cell death caused by 6-OHDA. Here, we demonstrate that undifferentiated and RA-differentiated SH-SY5Y cells are two unique phenotypes and also have dissimilar mechanisms in 6-OHDA cytotoxicity. Hence, our data support the use of RA-differentiated SH-SY5Y cells as an in vitro model of PD. This study may impact our understanding of the pathological mechanisms of PD and the development of new therapies and drugs for the management of the disease.- Published
- 2017
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15. Reduced Bone Stiffness in Women Is Associated with Clinical Attachment and Tooth Loss: The Study of Health in Pomerania.
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Silveira JL, Albers M, Vargas DM, Santa Helena ET, Cordova CM, Hannemann A, Wallaschofski H, Meisel P, Pink C, Samietz S, Schmidt CO, Holtfreter B, Völzke H, Dörr M, Kocher T, and Markus MR
- Subjects
- Absorptiometry, Photon, Adult, Aged, Aged, 80 and over, Female, Germany epidemiology, Humans, Middle Aged, Risk Factors, Bone Density, Calcaneus diagnostic imaging, Calcaneus pathology, Periodontal Attachment Loss epidemiology, Tooth Loss epidemiology
- Abstract
The authors evaluated the association of reduced bone stiffness of the calcaneus with clinical attachment loss (CAL) and tooth loss. The authors analyzed data from 4,678 subjects (2,384 women), aged 20 to 88 y, from the second follow-up of the population-based Study of Health in Pomerania (SHIP-2) and the baseline examination of the SHIP-Trend cohort. Bone stiffness, characterized by the stiffness index (SI) and the osteoporotic fracture risk (OFR), was assessed by quantitative ultrasound of the heel. SI and OFR were significantly associated with the mean CAL in women. While 1) the SI showed a significant association with the mean CAL and 2) the OFR with the median number of teeth in just the postmenopausal women, the OFR showed a significant association with mean CAL for both pre- and postmenopausal women. In postmenopausal women, a 10-unit increase in the SI was associated with a decrease in the mean CAL of 0.05 mm (95% confidence interval [CI]: -0.10 to 0.00; P = 0.046). Moreover, the adjusted median number of teeth was 21.4 (95% CI: 20.9 to 21.9) among the postmenopausal women with a low OFR, while it was 19.1 (95% CI: 17.8 to 20.3; P = 0.001) among the postmenopausal women with a high OFR. For the premenopausal women with a low OFR, the mean CAL was 1.60 mm (95% CI: 1.53 to 1.66), while for the premenopausal women with a high OFR, it was 2.24 mm (95% CI: 1.78 to 2.69; P = 0.006). Reduced bone stiffness was associated with clinical attachment and tooth loss in women but not in men., (© International & American Associations for Dental Research 2016.)
- Published
- 2016
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16. Asymptomatic vertebral fractures in patients with low bone mineral density.
- Author
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Negreiros CC, Berigo MG, Dominoni RL, and Vargas DM
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- Absorptiometry, Photon, Adult, Aged, Aged, 80 and over, Asymptomatic Diseases epidemiology, Brazil epidemiology, Cross-Sectional Studies, Densitometry methods, Female, Humans, Logistic Models, Male, Middle Aged, Osteoporotic Fractures epidemiology, Osteoporotic Fractures physiopathology, Prevalence, Reference Values, Retrospective Studies, Risk Factors, Spinal Fractures physiopathology, Bone Density physiology, Spinal Fractures epidemiology, Spinal Fractures etiology
- Abstract
Objective: Vertebral fracture assessment (VFA) is a test technique that can be used to detect asymptomatic vertebral fractures (AVF). It uses dual energy X-ray bsorptiometry (DXA) and can be performed concurrently with bone densitometry. This study aims to assess the prevalence of AVF in patients with low bone mass., Methods: Cross-sectional study including 135 individuals with low bone mineral density (BMD) with a T-score < -2.0 standard deviation (SD) in a densitometry clinic located in the city of Blumenau (state of Santa Catarina). Anthropometric, clinical and lifestyle variables were obtained from history-taking and physical examination. Densitometric variables were obtained by bone mineral densitometry and VFA (Explorer, Hollogic®). Vertebral fractures were classified according to the Genant criteria. Student's t, chi-square and logistic regression were performed for statistical analysis., Results: AVFs occurred in 24.4% of the subjects. They were older compared to those without AVF (65±9.25 versus 60.1±8.66; p=0.005), and had a history of lowimpact fractures (38.24% versus 19.8%; OR 2.5; p=0.03). Half of the patients that reported steroid therapy had AVFs, compared to one fifth of those who did not use steroids (50% versus 21.49%; OR 3.6; p=0.01)., Conclusion: Asymptomatic vertebral fractures were present in approximately one fourth of patients. The risk factors associated were history of low-impact fracture, use of steroids and age > 61 years.
- Published
- 2016
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17. PD-1 Blunts the Function of Ovarian Tumor-Infiltrating Dendritic Cells by Inactivating NF-κB.
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Karyampudi L, Lamichhane P, Krempski J, Kalli KR, Behrens MD, Vargas DM, Hartmann LC, Janco JM, Dong H, Hedin KE, Dietz AB, Goode EL, and Knutson KL
- Subjects
- Animals, Female, Humans, Mice, Mice, Inbred C57BL, Ovarian Neoplasms pathology, Signal Transduction, Dendritic Cells immunology, NF-kappa B metabolism, Ovarian Neoplasms immunology, Programmed Cell Death 1 Receptor immunology
- Abstract
The PD-1:PD-L1 immune signaling axis mediates suppression of T-cell-dependent tumor immunity. PD-1 expression was recently found to be upregulated on tumor-infiltrating murine (CD11c(+)CD11b(+)CD8(-)CD209a(+)) and human (CD1c(+)CD19(-)) myeloid dendritic cells (TIDC), an innate immune cell type also implicated in immune escape. However, there is little knowledge concerning how PD-1 regulates innate immune cells. In this study, we examined the role of PD-1 in TIDCs derived from mice bearing ovarian tumors. Similar to lymphocytes, TIDC expression of PD-1 was associated with expression of the adapter protein SHP-2, which signals to NF-κB; however, in contrast to its role in lymphocytes, we found that expression of PD-1 in TIDC tonically paralyzed NF-κB activation. Further mechanistic investigations showed that PD-1 blocked NF-κB-dependent cytokine release in a SHP-2-dependent manner. Conversely, inhibition of NF-κB-mediated antigen presentation by PD-1 occurred independently of SHP-2. Collectively, our findings revealed that PD-1 acts in a distinct manner in innate immune cells compared with adaptive immune cells, prompting further investigations of the signaling pathways controlled by this central mediator of immune escape in cancer., (©2015 American Association for Cancer Research.)
- Published
- 2016
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18. Dissecting the interface between apicomplexan parasite and host cell: Insights from a divergent AMA-RON2 pair.
- Author
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Parker ML, Penarete-Vargas DM, Hamilton PT, Guérin A, Dubey JP, Perlman SJ, Spano F, Lebrun M, and Boulanger MJ
- Subjects
- Animals, Mice, Models, Molecular, Phylogeny, Protein Binding, Protozoan Proteins chemistry, Host-Parasite Interactions, Parasites physiology, Protozoan Proteins metabolism, Toxoplasma metabolism
- Abstract
Plasmodium falciparum and Toxoplasma gondii are widely studied parasites in phylum Apicomplexa and the etiological agents of severe human malaria and toxoplasmosis, respectively. These intracellular pathogens have evolved a sophisticated invasion strategy that relies on delivery of proteins into the host cell, where parasite-derived rhoptry neck protein 2 (RON2) family members localize to the host outer membrane and serve as ligands for apical membrane antigen (AMA) family surface proteins displayed on the parasite. Recently, we showed that T. gondii harbors a novel AMA designated as TgAMA4 that shows extreme sequence divergence from all characterized AMA family members. Here we show that sporozoite-expressed TgAMA4 clusters in a distinct phylogenetic clade with Plasmodium merozoite apical erythrocyte-binding ligand (MAEBL) proteins and forms a high-affinity, functional complex with its coevolved partner, TgRON2L1. High-resolution crystal structures of TgAMA4 in the apo and TgRON2L1-bound forms complemented with alanine scanning mutagenesis data reveal an unexpected architecture and assembly mechanism relative to previously characterized AMA-RON2 complexes. Principally, TgAMA4 lacks both a deep surface groove and a key surface loop that have been established to govern RON2 ligand binding selectivity in other AMAs. Our study reveals a previously underappreciated level of molecular diversity at the parasite-host-cell interface and offers intriguing insight into the adaptation strategies underlying sporozoite invasion. Moreover, our data offer the potential for improved design of neutralizing therapeutics targeting a broad range of AMA-RON2 pairs and apicomplexan invasive stages.
- Published
- 2016
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19. Ultrasound findings in ocular trauma.
- Author
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Almendárez JE, Vargas DM, González C, Takane M, and Koga W
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Child, Child, Preschool, Eye Foreign Bodies diagnostic imaging, Eye Foreign Bodies etiology, Female, Humans, Infant, Male, Middle Aged, Prospective Studies, Retinal Detachment diagnostic imaging, Retinal Detachment etiology, Vitreous Hemorrhage diagnostic imaging, Vitreous Hemorrhage etiology, Wounds, Nonpenetrating diagnostic imaging, Young Adult, Eye Injuries diagnostic imaging, Ultrasonography methods
- Abstract
Objective: To evaluate the frequencies of various eye and/or orbital disorders by ultrasound examination in patients with ocular trauma., Materials and Methods: This prospective and descriptive study was conducted on 100 patients with ocular trauma treated in the Conde de Valenciana Institute from March to November 2014. Ultrasound examination was performed primarily using ultrasound B mode, with standardised A mode only used as correlation method. Age, gender, type of trauma, and various ultrasound findings were recorded., Results: Ocular trauma was more frequent in men (83%) compared to women (17%). The left eye was affected in 55%, and right eye in 45%, with 55% being open traumas and 45% blunt traumas. Most cases were young patients with a mean age of 33.7 years, with the group between 41 to 50 years being the most affected. Among the most frequent injuries found was the vitreous haemorrhage (45%) and posterior hyaloid detachment (38%), followed by retinal detachment (32%), and choroidal detachment (18%)., Conclusion: Ultrasound remains as the investigation method of choice in patients with ocular trauma, since it is a simple, cheap and non-invasive study, and can be very useful in providing diagnostic and prognostic information. This study demonstrated that trauma is more common in young men, with vitreous haemorrhage as the most common finding., (Copyright © 2015 Sociedad Española de Oftalmología. Published by Elsevier España, S.L.U. All rights reserved.)
- Published
- 2015
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20. Characterization of 14-3-3 isoforms expressed in the Echinococcus granulosus pathogenic larval stage.
- Author
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Teichmann A, Vargas DM, Monteiro KM, Meneghetti BV, Dutra CS, Paredes R, Galanti N, Zaha A, and Ferreira HB
- Subjects
- Amino Acid Sequence, Animals, Benzhydryl Compounds, Chromatography, Affinity, Cloning, Molecular, Cluster Analysis, Fluorescent Antibody Technique, Gene Components, Glucosides, Immunoblotting, Larva metabolism, Larva pathogenicity, Mass Spectrometry, Molecular Sequence Data, Protein Interaction Mapping, Protein Isoforms genetics, Protein Isoforms metabolism, 14-3-3 Proteins genetics, 14-3-3 Proteins metabolism, Echinococcosis parasitology, Echinococcus granulosus metabolism, Echinococcus granulosus pathogenicity, Ligands, Phylogeny
- Abstract
The 14-3-3 protein family of eukaryotic regulators was studied in Echinococcus granulosus, the causative agent of cystic hydatid disease. These proteins mediate important cellular processes in eukaryotes and are expected to play important roles in parasite biology. Six isoforms of E. granulosus 14-3-3 genes and proteins (Eg14-3-3.1-6) were analyzed, and their phylogenetic relationships were established with bona fide 14-3-3 orthologous proteins from eukaryotic species. Eg14-3-3 isoforms with previous evidence of expression (Eg14-3-3.1-4) in E. granulosus pathogenic larval stage (metacestode) were cloned, and recombinant proteins were used for functional studies. These protein isoforms were detected in different components of E. granulosus metacestode, including interface components with the host. The roles that are played by Eg14-3-3 proteins in parasite biology were inferred from the repertoires of interacting proteins with each isoform, as assessed by gel overlay, cross-linking, and affinity chromatography assays. A total of 95 Eg14-3-3 protein ligands were identified by mass spectrometry. Eg14-3-3 isoforms have shared partners (44 proteins), indicating some overlapping functions; however, they also bind exclusive partners (51 proteins), suggesting Eg14-3-3 functional specialization. These ligand repertoires indicate the involvement of Eg14-3-3 proteins in multiple biochemical pathways in the E. granulosus metacestode and note some degree of isoform specialization.
- Published
- 2015
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21. A chemical proteomics approach for the search of pharmacological targets of the antimalarial clinical candidate albitiazolium in Plasmodium falciparum using photocrosslinking and click chemistry.
- Author
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Penarete-Vargas DM, Boisson A, Urbach S, Chantelauze H, Peyrottes S, Fraisse L, and Vial HJ
- Subjects
- Animals, Antimalarials chemistry, Antimalarials metabolism, Antimalarials pharmacology, Binding, Competitive, Click Chemistry, Cross-Linking Reagents chemistry, Diacylglycerol Cholinephosphotransferase metabolism, Endoplasmic Reticulum metabolism, Humans, Malaria, Falciparum metabolism, Malaria, Falciparum parasitology, Models, Chemical, Molecular Structure, Plasmodium falciparum metabolism, Protein Binding, Proteome chemistry, Protozoan Proteins chemistry, Thiazoles chemistry, Thiazoles metabolism, trans-Golgi Network metabolism, Malaria, Falciparum prevention & control, Plasmodium falciparum drug effects, Proteome metabolism, Proteomics methods, Protozoan Proteins metabolism, Thiazoles pharmacology
- Abstract
Plasmodium falciparum is responsible for severe malaria which is one of the most prevalent and deadly infectious diseases in the world. The antimalarial therapeutic arsenal is hampered by the onset of resistance to all known pharmacological classes of compounds, so new drugs with novel mechanisms of action are critically needed. Albitiazolium is a clinical antimalarial candidate from a series of choline analogs designed to inhibit plasmodial phospholipid metabolism. Here we developed an original chemical proteomic approach to identify parasite proteins targeted by albitiazolium during their native interaction in living parasites. We designed a bifunctional albitiazolium-derived compound (photoactivable and clickable) to covalently crosslink drug-interacting parasite proteins in situ followed by their isolation via click chemistry reactions. Mass spectrometry analysis of drug-interacting proteins and subsequent clustering on gene ontology terms revealed parasite proteins involved in lipid metabolic activities and, interestingly, also in lipid binding, transport, and vesicular transport functions. In accordance with this, the albitiazolium-derivative was localized in the endoplasmic reticulum and trans-Golgi network of P. falciparum. Importantly, during competitive assays with albitiazolium, the binding of choline/ethanolamine phosphotransferase (the enzyme involved in the last step of phosphatidylcholine synthesis) was substantially displaced, thus confirming the efficiency of this strategy for searching albitiazolium targets.
- Published
- 2014
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22. A ΔdinB mutation that sensitizes Escherichia coli to the lethal effects of UV- and X-radiation.
- Author
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Lee MC, Franco M, Vargas DM, Hudman DA, White SJ, Fowler RG, and Sargentini NJ
- Subjects
- Adenosine Triphosphatases genetics, Adenosine Triphosphatases metabolism, Alleles, DNA Helicases genetics, DNA Helicases metabolism, DNA-Binding Proteins genetics, DNA-Binding Proteins metabolism, DNA-Directed DNA Polymerase genetics, DNA-Directed DNA Polymerase metabolism, Escherichia coli genetics, Escherichia coli Proteins metabolism, X-Rays, Escherichia coli metabolism, Escherichia coli Proteins genetics, Microbial Viability genetics, Microbial Viability radiation effects, Mutation, Ultraviolet Rays
- Abstract
The DinB (PolIV) protein of Escherichia coli participates in several cellular functions. We investigated a dinB mutation, Δ(dinB-yafN)883(::kan) [referred to as ΔdinB883], which strongly sensitized E. coli cells to both UV- and X-radiation killing. Earlier reports indicated dinB mutations had no obvious effect on UV radiation sensitivity which we confirmed by showing that normal UV radiation sensitivity is conferred by the ΔdinB749 allele. Compared to a wild-type strain, the ΔdinB883 mutant was most sensitive (160-fold) in early to mid-logarithmic growth phase and much less sensitive (twofold) in late log or stationary phases, thus showing a growth phase-dependence for UV radiation sensitivity. This sensitizing effect of ΔdinB883 is assumed to be completely dependent upon the presence of UmuDC protein; since the ΔdinB883 mutation did not sensitize the ΔumuDC strain to UV radiation killing throughout log phase and early stationary phase growth. The DNA damage checkpoint activity of UmuDC was clearly affected by ΔdinB883 as shown by testing a umuC104 ΔdinB883 double-mutant. The sensitivities of the ΔumuDC strain and the ΔdinB883 ΔumuDC double-mutant strain were significantly greater than for the ΔdinB883 strain, suggesting that the ΔdinB883 allele only partially suppresses UmuDC activity. The ΔdinB883 mutation partially sensitized (fivefold) uvrA and uvrB strains to UV radiation, but did not sensitize a ΔrecA strain. A comparison of the DNA sequences of the ΔdinB883 allele with the sequences of the Δ(dinB-yafN)882(::kan) and ΔdinB749 alleles, which do not sensitize cells to UV radiation, revealed ΔdinB883 is likely a "gain-of-function" mutation. The ΔdinB883 allele encodes the first 54 amino acids of wild-type DinB followed by 29 predicted residues resulting from the continuation of the dinB reading frame into an adjacent insertion fragment. The resulting polypeptide is proposed to interfere directly or indirectly with UmuDC function(s) involved in protecting cells against the lethal effects of radiation., (Copyright © 2014 Elsevier B.V. All rights reserved.)
- Published
- 2014
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23. [Secular trend of growth in stature in Florianópolis in the state of Santa Catarina (Brazil) in relation with the human development index (HDI)].
- Author
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Pinheiro AC, Niederauer JM, and Vargas DM
- Subjects
- Adolescent, Brazil, Cross-Sectional Studies, Human Development, Humans, Military Personnel, Retrospective Studies, Time Factors, Young Adult, Body Height, Economic Development
- Abstract
The article seks to evaluate the secular trend of growth in stature of recruits in the 63rd Infantry Battalion in Florianópolis and correlate the information with the human development index (HDI). It involves a transversal and retrospective study of recruits aged between 18 and 20 who joined the 63rd IB in Florianópolis from 1963 to 2007. The sample comprised 600 individuals out of a total of 3000 recruits enlisted over the period. In each decade, three years were selected and within these years the first 40 files were systematically selected for analysis. It was seen that there was an increase in the order of 7 cm in height of recruits in Florianopolis over the past 47 years. This increase was more marked between the decades of 1990 and 2000, with the municipality of Blumenau having the highest average. The average heights study over the decades showed a strong positive correlation with the HDI of Florianopolis during the same period. When comparing the heights of the capital of Santa Catarina and previous studies in Blumenau, it was found that both cities have achieved the same increase of 1.4 cm/decade in the period between the 1960 and 2000. There was a positive secular trend in growth in Florianopolis, with a strong correlation with HDI values of the city between 1960 and 2000.
- Published
- 2014
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24. Validation of a hydride generation atomic absorption spectrometry methodology for determination of mercury in fish designed for application in the Brazilian national residue control plan.
- Author
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Damin IC, Santo MA, Hennigen R, and Vargas DM
- Subjects
- Animals, Brazil, Fishes, Fish Products analysis, Food Contamination analysis, Mercury analysis, Spectrophotometry, Atomic methods
- Abstract
In the present study, a method for the determination of mercury (Hg) in fish was validated according to ISO/IEC 17025, INMETRO (Brazil), and more recent European recommendations (Commission Decision 2007/333/EC and 2002/657/EC) for implementation in the Brazilian Residue Control Plan (NRCP) in routine applications. The parameters evaluated in the validation were investigated in detail. The results obtained for limit of detection and quantification were respectively, 2.36 and 7.88 μg kg(-1) of Hg. While the recovery varies between 90-96%. The coefficient of variation was of 4.06-8.94% for the repeatability. Furthermore, a comparison using an external proficiency testing scheme was realized. The results of method validated for the determination of the mercury in fish by Hydride generation atomic absorption spectrometry were considered suitable for implementation in routine analysis.
- Published
- 2013
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25. Bone mass and body composition in college students.
- Author
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Reuter C, Stein CE, and Vargas DM
- Subjects
- Absorptiometry, Photon, Adult, Brazil, Cohort Studies, Cross-Sectional Studies, Female, Humans, Male, Socioeconomic Factors, Universities, Body Composition, Bone Density, Life Style, Students
- Abstract
Objective: To compare bone mineral density (BMD) and body composition (BC) of college students with different lifestyles., Methods: Transversal study with 85 students of Medicine (MED) and Physical Education (PE) at the Universidade Regional de Blumenau, SC, Brazil. The anthropometric, socio-demographic, clinical, and lifestyle variables were obtained through densitometric anamnesis and densitometric variables by dual-energy X-ray (DXA). The statistical tests used were: Student's t-test, Chi-square test, and logistic regression., Results: PE male students showed a higher amount of lean body mass (79.5 ± 5.9 vs. 75.1 ± 5.3; p = 0.03) and a lower amount of body fat (16.7 ± 6.1 vs. 21.6 ± 5.6; p = 0.02) and PE female students showed a higher amount of lean body mass (68.2 ± 5.5 vs. 65.3 ± 5.5; p = 0.05). The BMD of the neck of femur (NOF), total femur (TF), and total body (TB) was higher in PE students of both genders. PE students practiced more physical activities than MED students. Low bone mass (LBM) was more frequent in MED students (34.9% vs. 4.7%; p = 0.001), provided that the risk of a MED student to show LBM was nine times higher for lumbar spine (LS), five times for NOF, eight times for TF, and seven times for TB., Conclusion: BC and BMD were different among the students; MED students have shown a higher risk of having LBM, and PE students practiced more physical activities.
- Published
- 2012
26. Excretory/secretory products from in vitro-cultured Echinococcus granulosus protoscoleces.
- Author
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Virginio VG, Monteiro KM, Drumond F, de Carvalho MO, Vargas DM, Zaha A, and Ferreira HB
- Subjects
- Acetylation, Animals, Antigens, Helminth immunology, Antigens, Helminth metabolism, Cattle, Culture Media, Conditioned chemistry, Culture Techniques, Echinococcosis parasitology, Echinococcus granulosus growth & development, Helminth Proteins immunology, Humans, Immune Sera chemistry, Life Cycle Stages, Molecular Sequence Annotation, Protein Processing, Post-Translational, Echinococcosis metabolism, Echinococcus granulosus metabolism, Helminth Proteins metabolism
- Abstract
Cystic hydatid disease (CHD) is caused by infection with Echinococcus granulosus metacestodes and affects humans and livestock. Proteins secreted or excreted by protoscoleces, pre-adult worms found in the metacestode, are thought to play fundamental roles in the host-parasite relationship. In this work, we performed an LC-MS/MS proteomic analysis of the excretory-secretory products obtained from the first 48 h of an in vitro culture of the protoscoleces. We identified 32 proteins, including 18 that were never detected previously in metacestode proteomic studies. Among the novel identified excretory-secretory products are antigenic proteins, such as EG19 and P-29 and a calpain protease. We also identified other important protoscolex excretory-secretory products, such as thioredoxin peroxidase and 14-3-3 proteins, which are potentially involved in evasion mechanisms adopted by parasites to establish infection. Several intracellular proteins were found in the excretory-secretory products, revealing a set of identified proteins not previously thought to be exposed at the host-parasite interface. Additionally, immunological analyses established the antigenic profiles of the newly identified excretory-secretory products and revealed, for the first time, the in vitro secretion of the B antigen by protoscoleces. Considering that the excretory-secretory products obtained in vitro might reflect the products released and exposed to the host in vivo, our results provide valuable information on parasite survival strategies in adverse host environments and on the molecular mechanisms underpinning CHD immunopathology., (Copyright © 2012 Elsevier B.V. All rights reserved.)
- Published
- 2012
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27. Echinococcus granulosus antigen B structure: subunit composition and oligomeric states.
- Author
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Monteiro KM, Cardoso MB, Follmer C, da Silveira NP, Vargas DM, Kitajima EW, Zaha A, and Ferreira HB
- Subjects
- Amino Acid Sequence, Animals, Cattle, Echinococcosis parasitology, Electrophoresis, Humans, Lipoproteins isolation & purification, Mass Spectrometry, Microscopy, Molecular Sequence Data, Protein Subunits chemistry, Sequence Homology, Amino Acid, Lipoproteins chemistry, Protein Multimerization
- Abstract
Background: Antigen B (AgB) is the major protein secreted by the Echinococcus granulosus metacestode and is involved in key host-parasite interactions during infection. The full comprehension of AgB functions depends on the elucidation of several structural aspects that remain unknown, such as its subunit composition and oligomeric states., Methodology/principal Findings: The subunit composition of E. granulosus AgB oligomers from individual bovine and human cysts was assessed by mass spectrometry associated with electrophoretic analysis. AgB8/1, AgB8/2, AgB8/3 and AgB8/4 subunits were identified in all samples analyzed, and an AgB8/2 variant (AgB8/2v8) was found in one bovine sample. The exponentially modified protein abundance index (emPAI) was used to estimate the relative abundance of the AgB subunits, revealing that AgB8/1 subunit was relatively overrepresented in all samples. The abundance of AgB8/3 subunit varied between bovine and human cysts. The oligomeric states formed by E. granulosus AgB and recombinant subunits available, rAgB8/1, rAgB8/2 and rAgB8/3, were characterized by native PAGE, light scattering and microscopy. Recombinant subunits showed markedly distinct oligomerization behaviors, forming oligomers with a maximum size relation of rAgB8/3>rAgB8/2>rAgB8/1. Moreover, the oligomeric states formed by rAgB8/3 subunit were more similar to those observed for AgB purified from hydatid fluid. Pressure-induced dissociation experiments demonstrated that the molecular assemblies formed by the more aggregative subunits, rAgB8/2 and rAgB8/3, also display higher structural stability., Conclusions/significance: For the first time, AgB subunit composition was analyzed in samples from single hydatid cysts, revealing qualitative and quantitative differences between samples. We showed that AgB oligomers are formed by different subunits, which have distinct abundances and oligomerization properties. Overall, our findings have significantly contributed to increase the current knowledge on AgB expression and structure, highlighting issues that may help to understand the parasite adaptive response during chronic infection.
- Published
- 2012
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28. [Secular trend of growth in Blumenau, Santa Catarina State].
- Author
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Soncini AS, Vargas DM, Arena MG, and Arena LF
- Subjects
- Adolescent, Brazil, Cross-Sectional Studies, Humans, Male, Retrospective Studies, Young Adult, Body Height, Growth, Military Personnel
- Abstract
Secular trend of growth refers to any change of the corporal size in determined population group in long periods of time. The objective of this work is to study the secular tendency of growth in natural height among recruits in Blumenau, Santa Catarina State, between the years of 1963 and 2007. This is a transversal, retrospective and analytical study. Young recruits, aged 18 to 20 were chosen as the population. A standardized database was used on individual records with the first 40 records of each year being selected. Data from 1963 to 2007 were collected and separated per decades. A margin of error not higher than 3.5% was used as a demonstration, which resulted in a sample of 600 individuals. The t-test was used to compare the averages of different decades. The results showed an increase of 7 cm in the height of the population in Blumenau in the last 50 years. The positive trend that is occurring in our country in the most recent evaluations can be attributed to better sanitary, economic and social conditions. The secular tendency of growth in height was positive in the municipality of Blumenau. It was found that the population increased 7 cm in the final height in the last 50 years with a growth rate of 0.14 cm/year or 1.4 cm/decade.
- Published
- 2011
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29. [Secular trends in stature growth in Blumenau-Brazil in relation to human development index (HDI)].
- Author
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Vargas DM, Arena LF, and Soncini AS
- Subjects
- Adolescent, Brazil, Cross-Sectional Studies, Humans, Linear Models, Male, Military Personnel, Time Factors, Young Adult, Body Height physiology, Human Development
- Abstract
Objective: The objective of this study was to analyze the secular trend of growth in height of military recruits enlisted in Blumenau and correlate it with the HDI index., Methods: This was a cross-sectional study of recruits aged 18 to 20 enlisted to the 23rd Infantry Battalion in Blumenau between 1963 to 2007. The sample comprised 600 out of a total of 3000 recruits enlisted over the period. Data were collected from individual enlistment files on recruits which had been archived by year. Three years were analyzed from each decade (x3, x5, and x7) and the first forty files were selected systematically from each recruitment year for analysis. Statistical analysis was with descriptive statistics, Student's t test and simple linear regression., Results: There was an increase of the order of 7 cm in the height of recruits in Blumenau over the last 47 years (from 1.7 meters in the 1960s to 1.77 meters in the 2000s) and the increase was most evident between the 1970s and 1980s. The mean heights in years in different decades exhibited a strong and positive correlation with the HDI in Blumenau and Brazil, which both increased progressively during the study period., Conclusion: The secular tendency in growth in height was positive in Blumenau and had a positive correlation with HDI.
- Published
- 2010
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30. Protection against lethal Neospora caninum infection in mice induced by heterologous vaccination with a mic1 mic3 knockout Toxoplasma gondii strain.
- Author
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Penarete-Vargas DM, Mévélec MN, Dion S, Sèche E, Dimier-Poisson I, and Fandeur T
- Subjects
- Animals, Antibodies, Protozoan blood, Antibodies, Protozoan immunology, Blotting, Western, Cell Adhesion Molecules deficiency, Cell Adhesion Molecules genetics, Cross Reactions, Enzyme-Linked Immunosorbent Assay, Female, Mice, Protozoan Proteins genetics, Toxoplasma genetics, Vaccination, Vaccines, Attenuated immunology, Cell Adhesion Molecules immunology, Coccidiosis prevention & control, Neospora immunology, Protozoan Proteins immunology, Protozoan Vaccines immunology, Toxoplasma immunology
- Abstract
Neospora caninum and Toxoplasma gondii are closely related, obligate intracellular parasites infecting a wide range of vertebrate hosts and causing abortion and neonatal morbidity and mortality. Several lines of evidence suggest that cross immunity between these two pathogens could be exploited in the design of strategies for heterologous vaccination. We assessed the ability of an attenuated strain of T. gondii ("mic1-3KO strain") conferring strong protection against chronic and congenital toxoplasmosis to protect mice against lethal N. caninum infection. Mice immunized with mic1-3KO tachyzoites by the oral and intraperitoneal routes developed a strong cellular Th1 response and displayed significant protection against lethal heterologous N. caninum infection, with survival rates of 70% and 80%, respectively, whereas only 30% of the nonimmunized mice survived. We report here the acquisition of heterologous protective immunity against N. caninum following immunization with a live attenuated mic1-3KO strain of T. gondii.
- Published
- 2010
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31. As time goes by ... would CD4+ T cells depletion induce early immunosenescence in HIV infected patients?
- Author
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Peres A, Lerias AG, de Aguiar AK, Silva AO, Costa CB, Bemfica C, de Vargas DM, Andrade Dde S, Engelke DS, Pires EN, Furtado GV, Erpen GL, De Nardin J, Otton LM, Tortorelli LS, da Rosa PM, and Chies JA
- Subjects
- Animals, CD8-Positive T-Lymphocytes immunology, Central Nervous System pathology, HIV Infections immunology, Humans, Immune System, Neurodegenerative Diseases pathology, T-Lymphocytes cytology, CD4-Positive T-Lymphocytes immunology, HIV Infections blood
- Published
- 2010
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32. [Bone mineralization in children and adolescents with type 1 diabetes].
- Author
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Vargas DM, Rigotti T, Gütz CN, Lobe MC, and Fernades Jde A
- Subjects
- Adolescent, Child, Female, Humans, Male, Prognosis, Bone Density, Diabetes Mellitus, Type 1 metabolism
- Abstract
Objective: To evaluate the occurrence of osteopenia and the prognostic factors of bone mass in a pediatric group with type 1 diabetes., Methods: The following parameters were analyzed in a group of 23 patients with type 1 diabetes aged 10.9 -/+ 2.9 years: bone mineral density, serum C peptide, glycosylated hemoglobin, serum calcium, serum alkaline phosphatase, serum phosphorus and calciuria. Clinical variables included age, weight, height, body mass index, pubertal stage, insulin doses, duration of diabetes and calcium intake. Bone mineral density was evaluated in the lumbar spine and the results were expressed in deviation standard score by age and sex. Calcium intake was calculated based on feeding report, body mass index was calculated using the Quetelet formula and pubertal stage was defined according to the Tanner-Whitehouse criteria. Simple linear regression was used to analyze correlations between variables and the Mann-Whitney U test was used to compare groups., Results: Average bone mineral density was normal (-0.75 -/+ 1.01 SD). However we verified that 39.1% of the patients had osteopenia. When comparing data of osteopenic patients (n = 9) to non-osteopenic patients (n =1 4), we observed that C peptide of osteopenic group was higher than that of non-osteopenic group (0.56 -/+ 0.18 vs 0.29 -/+ 0.20; p < 0.05). Body mass index and C peptide correlated with bone mineral density. Duration of diabetes was inversely correlated with C peptide (p < 0.01) and directly correlated with insulin doses (p < 0.01)., Conclusion: Osteopenia occurred in 39.1% of the patients with type 1 diabetes. The presence of osteopenia was related to higher levels of C peptide.
- Published
- 2003
33. Clinical and biochemical determinants of bone metabolism and bone mass in adolescent female patients with anorexia nervosa.
- Author
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Audí L, Vargas DM, Gussinyé M, Yeste D, Martí G, and Carrascosa A
- Subjects
- Adolescent, Adult, Biomarkers, Calcium metabolism, Estradiol blood, Female, Growth Hormone urine, Humans, Insulin-Like Growth Factor Binding Protein 1 blood, Insulin-Like Growth Factor Binding Protein 3 blood, Insulin-Like Growth Factor I metabolism, Regression Analysis, Sex Hormone-Binding Globulin metabolism, Anorexia Nervosa metabolism, Bone Density, Bone and Bones metabolism
- Abstract
Among pathologies prevalent in western societies, anorexia nervosa has increased over the last decade. Its effects on bone mass need to be defined, and prognostic factors, either clinical or biochemical, could aid clinicians in individual patient management. To determine which clinical and/or biochemical parameters could be related to bone mass status in adolescent female anorexia nervosa patients, 73 female patients were classified according to different stages of their illness and studied in terms of clinical and biochemical parameters and bone densitometric mineral content at lumbar spine. Patients (age 17.2 +/- 1.7 y, mean +/- SD) with Tanner pubertal stage 5, regular menstruation for more than 3 mo before the onset of secondary amenorrhea, and diagnosed with anorexia nervosa were consecutively studied and classified in three clinical situations: I) active phase (34 patients): undernourished and amenorrheic; II) weight recovered but still amenorrheic (20 patients); III) fully recovered (19 patients). Clinical data were recorded at the time of bone density measurement, concomitant with blood sample extraction for study of IGF-I, IGF-binding protein 3 (IGFBP-3), IGFBP-1, estradiol, sex hormone-binding globulin, dehydroepiandrosterone sulfate, prealbumin, amino-terminal propeptide of procollagen III, osteocalcin, bone alkaline phosphatase, carboxy-terminal propeptide of procollagen I, amino-terminal propeptide of procollagen I, carboxy-terminal telopeptide of collagen I, 25-OH-vitamin D, 1,25(OH)(2)-vitamin D, and parathormone. In addition, a 24-h urine collection was made for cortisol, GH, deoxypyridinoline, amino-terminal telopeptide of collagen I, and calcium and creatinine content analysis. IGF-I, estradiol, and biochemical bone formation markers were higher and IGFBP-1, sex hormone-binding globulin, and biochemical bone resorption markers were lower in the weight-recovered stages (stages II and III) compared with the active phase (stage I). Bone formation markers correlated positively with body mass index SD score and IGF-I, whereas bone resorption markers correlated negatively with body mass index SD score and estradiol. Although no statistically significant differences regarding lumbar spine bone mineral density SD score values were recorded among the three stages of the illness, the proportion of osteopenic patients was clearly lower among stage III patients. The actual bone mineral density was inversely related to the duration of amenorrhea and directly related to duration of postmenarcheal menses before amenorrhea. In addition, a subset of osteopenic patients (five of 19) in the fully clinically recovered group with accelerated bone turnover was identified. Normal circulating estrogen level exposure time predicts actual bone mineral density at lumbar spine in young adolescent anorexia nervosa patients. In addition to psychiatric and nutritional interventions, estrogen-deprivation periods must be shortened to less than 20 mo. Patients remaining osteopenic at full clinical recovery require additional follow-up studies.
- Published
- 2002
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34. The effect of a ceramide analog, N-acetylsphingosine on the induction of proliferation and IL-2 synthesis in T cells from young and old F344 rats.
- Author
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Pahlavani MA and Vargas DM
- Subjects
- Aging metabolism, Animals, Apoptosis drug effects, Apoptosis immunology, Cell Division drug effects, Cell Division immunology, Growth Inhibitors pharmacology, Immunosuppressive Agents pharmacology, Male, Rats, Rats, Inbred F344, T-Lymphocytes cytology, T-Lymphocytes drug effects, Aging immunology, Interleukin-2 biosynthesis, Lymphocyte Activation drug effects, Sphingosine analogs & derivatives, Sphingosine pharmacology, T-Lymphocytes immunology, T-Lymphocytes metabolism
- Abstract
Ceramide is a physiological mediator of extracellular signals that control various cellular functions, including proliferation and apoptosis. In the present study, we examined the effects of cell-permeable ceramide analog, N-acetyl-sphingosine (C(2)-ceramide) on the induction of proliferation and interleukin-2 (IL-2) synthesis in T cells from young and old rats. Splenic T cells from 6- and 24-month-old Fischer 344 rats were treated with C(2)-ceramide and then incubated with anti-CD3 antibody for 24 or 48 h. The induction of proliferation and IL-2 production by anti-CD3 was significantly (P<0.001) lower in T cells from old rats compared to T cells from young rats. C(2)-ceramide treatment resulted in suppression of proliferation and IL-2 production in a concentration-dependent manner. The suppressive effect of C(2)-ceramide on proliferation and IL-2 production was greater in T cells from old rats than T cells from young rats. We investigated whether this decreased responsiveness was due to induction of program cell death (apoptosis) and found that there was a significant increase in DNA fragmentation in C(2)-ceramide treated and anti-CD3 stimulated T cells from both young and old rats. The increase in DNA fragmentation was paralleled with an increase in caspase-3 activation. C(2)-ceramide-induced caspase-3 activation and DNA fragmentation was significantly (P<0.5) higher in stimulated T cells from old rats compared to stimulated T cells from young rats. These results suggest that the sphingomyelin-ceramide signaling pathway may play an important regulatory role in the well-documented age-related decline in immune function.
- Published
- 2000
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35. Normal immune function in young and old DNA polymerase-beta deficient mice.
- Author
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Pahlavani MA, Vargas DM, Guo Z, and Richardson A
- Subjects
- Animals, DNA Polymerase beta deficiency, DNA Polymerase beta genetics, Flow Cytometry, Interferon-gamma biosynthesis, Interleukins biosynthesis, Mice, Mice, Inbred C57BL, Mice, Knockout, Spleen cytology, Spleen immunology, Aging immunology, Cytokines biosynthesis, DNA Polymerase beta metabolism, Lymphocyte Activation, Lymphocytes immunology
- Abstract
The effect of the DNA polymerase-beta (beta-pol) deficiency on mitogenic response and cytokine production was studied in spleen lymphocytes from 4-5- and 20-22-month-old beta-pol(-/+) mice and their age-matched wild-type littermates. The proliferative response of lymphocytes to Concanavalin A (Con A) and lipopolysaccharide (LPS) was measured by [3H]thymidine incorporation, and the induction of cytokine production (interleukin (IL)-2, IL-4, and interferon necrosis factor (IFN)-gamma) was assessed by enzyme-linked immunosorbent assay. There was no significant difference in Con A- or LPS-induced proliferation or cytokine production in young beta-pol(-/+) mice compared with young wild-type littermates or in old beta-pol(-/+) mice compared with old wild-type littermates. However, mitogen-induced proliferation and cytokine production changed significantly with age. The proliferative response to Con A and to LPS, and the IL-2 production was significantly lower, and IL-4 and IFN-gamma levels were significantly higher in lymphocytes from old beta-pol(-/+) mice and old wild-type mice than in lymphocytes from young beta-pol(-/+) mice and young wild-type littermates. In addition, flow cytometric analysis showed no significant differences between young beta-pol(-/+) mice and young wild-type littermates or between old beta-pol(-/+) mice and old wild-type littermates in the proportion of B- and T-cell populations, and T-cell subsets. However, the number of lymphocytes expressing CD4+ phenotype slightly decreased and the proportion of lymphocytes expressing CD44/Pgp-1 (memory) phenotype increased with age. Thus, we found no evidence for alteration in immune function in DNA polymerase-beta deficient mice, although they exhibit a decline in immunologic function with age.
- Published
- 2000
- Full Text
- View/download PDF
36. Influence of aging and caloric restriction on activation of Ras/MAPK, calcineurin, and CaMK-IV activities in rat T cells.
- Author
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Pahlavani MA and Vargas DM
- Subjects
- Animals, Calcium-Calmodulin-Dependent Protein Kinase Type 4, Energy Intake, Enzyme Activation, Male, Rats, Rats, Inbred F344, Aging metabolism, Calcineurin metabolism, Calcium-Calmodulin-Dependent Protein Kinases metabolism, Mitogen-Activated Protein Kinases metabolism, Proto-Oncogene Proteins p21(ras) metabolism, T-Lymphocytes enzymology
- Abstract
The signaling cascade mediated by Ras (p21ras) and MAPK (mitogen-activated protein kinase) and calcium/calmodulin regulating enzymes, calcineurin (CaN) and CaMK-IV, are considered to be essential for T-cell growth and function. In the present study, the effect of aging and caloric restriction (CR) on the induction of Ras and MAPK activation by concanavalin A (ConA) was studied. Splenic T cells were isolated from young (4-6 months) and old (22-24 months) rats that had free access to food (control group), and from caloric restricted old (22-24 months) rats that beginning at 6 weeks of age were fed 60%(40% caloric restriction) of the diet consumed by the control rats. We found that the induction of Ras activity in T cells isolated from control old rats was lower (P<0.001) than that in control young rats. However, the levels of Ras activity in T cells isolated from CR old rats were similar to the levels in the age-matched control rats. The induction of MAPK activity in T cells isolated from control old rats and CR old rats was significantly less than in T cells isolated from control young rats, and caloric restriction significantly (P<0.05) reduced the age-related decline in MAPK activation. We also measured the induction of CaN and CaMK-IV activities by ConA in T cells from control young and old and CR old rats. The induction of both CaN and CaMK-IV activity decreased with age. Caloric restriction significantly (P<0.05) reduced the age-related decline in CaN activity, but had no significant effect on CaMK-IV activity. The changes in Ras/MAPK activation and in CaN and CaMK-IV activity with age or with CR were not associated with alterations in their corresponding protein levels. Thus, caloric restriction has a differential effect on the activation of the upstream signaling molecules that are altered with age.
- Published
- 2000
- Full Text
- View/download PDF
37. Age-related decline in activation of calcium/calmodulin-dependent phosphatase calcineurin and kinase CaMK-IV in rat T cells.
- Author
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Pahlavani MA and Vargas DM
- Subjects
- Aging metabolism, Animals, Blotting, Western, Calcimycin pharmacology, Calcium-Calmodulin-Dependent Protein Kinase Type 2, Calcium-Calmodulin-Dependent Protein Kinase Type 4, Calcium-Calmodulin-Dependent Protein Kinases drug effects, Cells, Cultured, Lymphocyte Activation drug effects, Male, Phosphoric Monoester Hydrolases drug effects, Precipitin Tests, Rats, Rats, Inbred F344, T-Lymphocytes cytology, T-Lymphocytes drug effects, Aging immunology, Calcium pharmacology, Calcium-Calmodulin-Dependent Protein Kinases metabolism, Lymphocyte Activation physiology, Phosphoric Monoester Hydrolases metabolism, T-Lymphocytes physiology
- Abstract
We have previously shown that the DNA binding activity of the transcription factor NFAT which plays a predominant role in IL-2 transcription decreases with age. Because the transactivation (dephosphorylation and nuclear translocation) of the NFAT-c (cytoplasmic component of the NFAT complex) is mediated by the calcium/calmodulin-dependent phosphatase, calcineurin (CaN), and because Ca2+/calmodulin-dependent kinases (CaMK-II and IV/Gr) have been shown to play a critical role in calcium signaling in T cells, it was of interest to determine what effect aging has on the activation and the levels of these calcium regulating enzymes. The induction of calcineurin phosphatase activity, and CaMK-II and IV/Gr activities, were studied in splenic T cells isolated from Fischer 344 rats at 6, 15, and 24 months of age. In addition, the changes in the protein levels of these enzymes were measured by Western blot. The calcineurin phosphatase activity and CaMK-II and IV kinase activities were at a maximum after the cells were incubated with anti-CD3 antibody for 5-10 minutes. The induction of calcineurin activity by anti-CD3 and by calcium ionophore (A23187) declined 65 and 55%, respectively, between 6 and 24 months of age. The induction of CaMK-IV activity, but not CaMK-II activity by anti-CD3, was significantly less (by 54%) in T cells from old rats compared to T cells from young rats. The decline in the activation of these enzymes with age was not associated with changes in their corresponding protein levels. These results demonstrate that alterations in calcineurin phosphatase activity and CaMK-IV activity may contribute to the well-documented age-related decline in T cell function.
- Published
- 1999
- Full Text
- View/download PDF
38. [Peptides derived from collagen: new biochemical markers of bone metabolism].
- Author
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Vargas DM, Audí L, and Carrascosa A
- Subjects
- Age Factors, Humans, Peptide Fragments, Biomarkers blood, Bone Development physiology, Bone Resorption blood, Bone and Bones metabolism, Collagen metabolism, Peptides blood
- Published
- 1997
- Full Text
- View/download PDF
39. The effect of a calcium antagonist on the retention of simple associational learning.
- Author
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Isaacson RL, Johnston JE, and Vargas DM
- Subjects
- Animals, Female, Rats, Retention, Psychology drug effects, Association Learning drug effects, Calcium Channel Blockers pharmacology, Learning drug effects, Nimodipine pharmacology
- Abstract
Using a newly developed training paradigm, rats were trained to associate a spatial location and a black interior with mild footshock and another adjacent location with white interior with the absence of footshock in three independent experiments. Retention of these associations was measured 24 and 48 hr after training in situation in which the animals could move freely between the black and white locations over a 90 sec test. Other rats were subjected to a control procedure in which shock was received on both the black and the white sides of the apparatus. In each of the experiments, half of the animals in the experimental and the control groups were trained following the administration of the calcium slow channel blocking agent, nimodipine (5 mg/kg), and the other half after saline administration. In experiment 1, the injections were given 15 min before training. In experiment 2, the injections were given chronically, over a 6 day period before training. In experiment 3, the animals were given a single injection 7 days before training. In all cases, retention was examined both 24 and 48 hr after training. The results were that the experimental procedures produce a strong aversion to the black portion of the apparatus. The greatest amount of retention was found in animals that had received the chronic injections, whether they were of saline or of nimodipine. In every aspect of retention in which the saline-treated rats were less than perfect in retention, the nimodipine animals exhibited superior performance.
- Published
- 1988
- Full Text
- View/download PDF
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