RESUMO
Genes are frequently lost or gained in malignant tumors and the analysis of these changes can be informative about the underlying tumor biology. Retinoblastoma is a pediatric intraocular malignancy, and since deletions in chromosome 13 have been described in this tumor, we performed genome wide sequencing with the Illumina platform to test whether recurrent losses could be detected in low coverage data from DNA pools of Rb cases. An in silico reference profile for each pool was created from the human genome sequence GRCh37p5; a chromosome integrity score and a graphics 40 Kb window analysis approach, allowed us to identify with high resolution previously reported non random recurrent losses in all chromosomes of these tumors. We also found a pattern of gains and losses associated to clear and dark cytogenetic bands respectively. We further analyze a pool of medulloblastoma and found a more stable genomic profile and previously reported losses in this tumor. This approach facilitates identification of recurrent deletions from many patients that may be biological relevant for tumor development.
Assuntos
Deleção Cromossômica , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Neoplasias da Retina/genética , Retinoblastoma/genética , Feminino , Humanos , Masculino , Meduloblastoma/genética , Análise de Sequência com Séries de Oligonucleotídeos , RecidivaRESUMO
Fusarium rot is considered a minor disease of citrus fruits. Several Fusarium species have been associated with fruit decay, most commonly F. lateritium Nees, F. moniliforme J. Sheld., F. oxysporum Schltdl., and F. solani (Mart.) Sacc. (2,3). In the winters of 2007, 2009, 2010, and 2011, lemon [Citrus limon (L.) Burm. f.] fruit with white mycelium covering the peduncle were submitted to the Phytopathology Lab at the Estación Experimental Agroindustrial Obispo Colombres. All fruit samples from Tucumán, Argentina, were stored in boxes kept in packinghouse for more than 1 month. In 2007 only, light to dark brown flavedo around the peduncle was observed in less than 1% of the sample fruit received. No internal breakdown was visible. No change in rind color was observed in the samples received in remaining years. Abundant Fusarium sp. conidia were observed on the mycelium. Colonies with white to violet fluffy aerial mycelium developed on potato dextrose agar (PDA) and produced abundant ovoid or oblong microconidia (1.9 to 3.6 × 4.8 to 10.8 µm), usually unicellular, borne in false heads on short monophialides, and loculated slightly falcate macroconidia were mostly three to five septate (2.4 to 4.8 × 19.2 to 31.2 µm). Unbranched and branched-monophialidic conidiophores were observed. Simple or paired chlamydospores developed on synthetic nutrient agar (1 g KH2PO4, 1 g KNO3, 0.5 g MgSO4.7H2O, 0.5 g KCl, 0.2 g sucrose, and 20 g agar/liter distilled water). On the basis of morphological and cultural criteria, 22 isolates were identified as F. oxysporum (4) designated as D1 to D22. Morfological identification was confirmed by PCR (1) using genomic DNA extracted from the mycelium of pure culture, and an amplified product of 70 bp, specific for the species F. oxysporum, was obtained. The internal transcribed spacer (ITS) region of rDNA was amplified using the primers ITS4/ITS5 and secuenced. BLAST analysis of the 600 bp segment showed a 100% indentity with F. oxysporum, strains CCF 4362 and 1166 (GenBank Accession Nos. HE974454 and FR731133, respectively). Pathogenicity tests were conducted twice by inoculating 10 surface-disinfected wounded lemon fruit. A rind disc (5 mm in diameter and 1 mm deep) near the stem end was removed and a 5-mm-diameter agar disc of D2 isolate (grown at 25°C for 5 days on PDA) was attached to the wound replacing the rind disc. The inoculation site was covered with moistened cotton wool and the fruit were wrapped in plastic bags to prevent the inoculum from drying out. Ten control fruit were inoculated with uncultured PDA plugs (5 mm in diameter). All fruit were maintained in a growth chamber at 25°C under humid conditions. After 5 to 6 days, all inoculated fruit showed white aerial mycelium, initially on the inoculation site and then on the peduncle, similar to that observed on naturally infected fruit. After 20 days, two fruit developed stem end dry rot and showed peduncle fall but no internal breakdown was visible. Control fruit developed any symptom as described above. F. oxysporum was consistently reisolated from infected tissues, completing Koch's postulates. To our knowledge, this is the first report of Fusarium rot caused by F. oxysporum on lemon in Tucumán, Argentina. References: (1) V. Edel et al. Mycol. Res. 104:518, 2000. (2) H. S. Fawcett. Citrus Diseases and Their Control, 1936. (3) A. Z. Joffe and M. Schiffmann-Nadel. Fruits 27:117, 1972. (4) P. E. Nelson et al. Fusarium species: An Illustrated Manual for Identification, 1983.
Assuntos
Transplante de Medula Óssea , Leucemia Mieloide de Fase Acelerada/terapia , Adulto , Evolução Fatal , Hemorragia/patologia , Humanos , Leucemia Mieloide de Fase Acelerada/complicações , Leucemia Mieloide de Fase Acelerada/patologia , Pneumopatias/patologia , Masculino , Condicionamento Pré-Transplante/efeitos adversos , Condicionamento Pré-Transplante/métodosRESUMO
A population genetic analysis of gene flow was conducted among 10 Aedes aegypti collections from seven cities along the northeastern coast of Mexico. Four collections were made from Monterrey to examine local patterns of gene flow. Markers included 60 random amplified polymorphic DNA (RAPD) loci amplified by the polymerase chain reaction and single strand conformation polymorphism analysis of variation in a 387-basepair region of the NADH dehydrogenase subunit 4 from the mitochondrial DNA (mtDNA). Seven mitochondrial haplotypes were detected and phylogenetic analysis identified two well-supported clades. Regression analysis of geographic distances and pairwise FST estimated from RAPD markers indicated that populations are isolated by distance and that free gene flow occurs among collections within 90-250 km. Isolation by distance was not detected using mtDNA haplotypes. The Nuevo Laredo collection had unique RAPD and mtDNA haplotype frequencies and reduced heterozygosity suggesting that few mosquitoes established this population.
Assuntos
Aedes/genética , Dengue/transmissão , Frequência do Gene/genética , Variação Genética/genética , Insetos Vetores/genética , Febre Amarela/transmissão , Aedes/química , Animais , Primers do DNA/química , DNA Mitocondrial/química , DNA Mitocondrial/isolamento & purificação , Eletroforese em Gel de Poliacrilamida , Feminino , Haplótipos , Humanos , Insetos Vetores/química , México , Filogenia , Reação em Cadeia da Polimerase , Polimorfismo Conformacional de Fita Simples , Técnica de Amplificação ao Acaso de DNA Polimórfico , Análise de Regressão , Análise de Sequência de DNARESUMO
Allergic fungal sinusitis is a recently reported disease of the nose and paranasal sinuses. Since the first reports by Lamb et al and Katzenstein there has been controversy about its diagnosis and treatment. Recently diagnostic criteria have been suggested. To our judgement they have a high degree of specificity. Allergy to fungi elements is essential. Currently surgical treatment consist in an adequate ventilation of the nose and paranasal sinuses followed by the use of oral and topical steroids. Immunotherapy is controversial and more prospective studies are needed to evaluate its possible use.
Assuntos
Hipersensibilidade/complicações , Micoses/complicações , Sinusite/complicações , Humanos , Sinusite/microbiologiaRESUMO
Dengue viruses are arthropod-borne, single-stranded RNA viruses. Aëdes aegypti and Aëdes albopictus are the principal vectors. In order to understand the molecular basis of dengue virus infections we explored the biochemical identity of dengue-2 (DEN-2) virus receptors in the Aëdes albopictus-derived cell line C6/36. We show here that DEN-2 interacts with two major polypeptides of 80 and 67 kDa. Polyclonal anti-C6/36 membrane antibodies block DEN-2 binding to intact C6/36 monolayers as well as to membrane extracts. Our results strongly suggest that the identified polypeptides are part of the DEN-2 receptors.
Assuntos
Aedes/virologia , Vírus da Dengue/metabolismo , Receptores Virais/isolamento & purificação , Aedes/química , Animais , Anticorpos/imunologia , Sítios de Ligação , Linhagem Celular , Membrana Celular/química , Vírus da Dengue/crescimento & desenvolvimento , Vírus da Dengue/isolamento & purificação , Peptídeos/imunologia , Receptores Virais/química , Receptores Virais/imunologia , Receptores Virais/metabolismoRESUMO
The protozoan Giardia lamblia initiates infection when trophozoites emerge from a cyst in the hosts by the excystation process. Although this process is crucial to the initiation of infection by G. lamblia, little is known about its regulation. To study the possible involvement of calmodulin (CaM) in excystation we tested the effect of several CaM antagonists (TFP, W-7, and W-5) on this cellular function. Except for W-5 the rest of these compounds inhibited excystation. The protein kinase C inhibitor H-7 had no effect on excystation, suggesting that CaM antagonists acted by selectively inhibiting CaM. Furthermore, CaM was redistributed after the induction of excystation and there was an increase in its fluorescence and activity. These results suggest that a CaM-dependent process is involved in G. lamblia excystation.
Assuntos
Calmodulina/fisiologia , Giardia lamblia/fisiologia , Sulfonamidas/farmacologia , Trifluoperazina/farmacologia , 1-(5-Isoquinolinasulfonil)-2-Metilpiperazina/farmacologia , 3',5'-AMP Cíclico Fosfodiesterases/metabolismo , Animais , Cálcio/metabolismo , Calmodulina/antagonistas & inibidores , Criança , Ativação Enzimática , Fezes/parasitologia , Giardia lamblia/efeitos dos fármacos , Giardia lamblia/isolamento & purificação , Giardíase/parasitologia , Humanos , Proteína Quinase C/antagonistas & inibidoresRESUMO
The interaction of Entamoeba histolytica trophozoites with collagen induces the synthesis and release of electron-dense granules containing a collagenase activity that is an important factor in the pathogenicity of the parasite. The binding is thought to be mediated by an 'integrin-like' collagen receptor. In the signal transduction mechanisms activated by collagen, pp125FAK and p42MAPK are involved. Using immunoprecipitation assays coupled to Western blot analysis, we demonstrate here the collagen-dependent association of paxillin and Src with pp125FAK. Furthermore, collagen induces a time-dependent increase in the DNA binding activity of the activator protein 1, which is well correlated with an increase in Fos expression. Our results suggest that a stimulus-transcription coupling triggered by collagen in E. histolytica trophozoites might activate or repress genes involved in tissue invasiveness.
Assuntos
Colágeno/farmacologia , DNA/metabolismo , Entamoeba histolytica/metabolismo , Fator de Transcrição AP-1/metabolismo , Animais , Moléculas de Adesão Celular/metabolismo , Proteínas do Citoesqueleto/metabolismo , Quinase 1 de Adesão Focal , Proteína-Tirosina Quinases de Adesão Focal , Paxilina , Fosfoproteínas/metabolismo , Proteínas Tirosina Quinases/metabolismo , Transdução de SinaisAssuntos
Grânulos Citoplasmáticos/metabolismo , Entamoeba histolytica/genética , RNA Mensageiro/análise , RNA de Protozoário/análise , Animais , Northern Blotting , Microanálise por Sonda Eletrônica , Entamoeba histolytica/patogenicidade , Entamoeba histolytica/ultraestrutura , Reação em Cadeia da PolimeraseRESUMO
The interaction of Entamoeba histolytica trophozoites with collagen involves cell adherence, formation, and release of electron dense granules (EDGs) containing collagenase activity leading to the degradation of the bound protein. The binding is thought to be mediated by an "integrin-like" collagen receptor. Since the signal transduction mechanisms triggered by the collagen-trophozoite interaction are unknown, but clearly involve cytoskeletal organization, we decided to explore the role of protein tyrosine phosphorylation in this process. Collagen induces a time-dependent increase in the phosphorylation of several polypeptides migrating around 67 and 110 kDa. One polypeptide of the high-molecular-weight component was identified as a 125-kDa protein with very similar epitopes to the focal treatment was a 42-kDa polypeptide related to the mitogen activated protein kinase (MAPK) family. Our results suggest that tyrosine phosphorylation is involved in collagen signaling in amoebas and that pp125FAK and p42MAPK homologs may play an active role in turning on the genetic program that enables the parasite to invade its host.
Assuntos
Moléculas de Adesão Celular/metabolismo , Colágeno/metabolismo , Entamoeba histolytica/fisiologia , Proteínas Tirosina Quinases/metabolismo , Transdução de Sinais/fisiologia , Animais , Western Blotting , Eletroforese em Gel de Poliacrilamida , Entamoeba histolytica/enzimologia , Quinase 1 de Adesão Focal , Proteína-Tirosina Quinases de Adesão Focal , Humanos , Fosforilação , Placenta/química , Testes de Precipitina , Proteínas de Protozoários/metabolismoRESUMO
In vitro interaction of Entamoeba histolytica trophozoites with collagen induces the intracellular formation and release of electron-dense granules (EDGs). We determined that four polypeptides in EDGs total antigen by SDS-PAGE were absent in trophozoite extracts. A monoclonal antibody raised against these EDGs recognized a polypeptide of 40 kDa specific for the pathogenic strains of E. histolytica. In addition, this mAb recognized a 96 kDa peptide masked by carbohydrates.
Assuntos
Anticorpos Monoclonais , Entamoeba histolytica/patogenicidade , Proteínas de Protozoários/análise , Animais , Especificidade de Anticorpos , Antígenos de Protozoários/análise , Colágeno/análise , Colágeno/metabolismo , Elétrons , Entamoeba histolytica/imunologiaRESUMO
Timely evacuation of alveolar fluid, release of surfactant and the beginning of continuous breathing, are key processes for an adequate adaptation of the fetus to the extrauterine life. Fetal vasopressin increases during labor and inhibit the secretion of tracheal fluid through a mechanism still unknown. The aim of this study was to elucidate the mechanism whereby vasopressin inhibit the secretion of lung fluid. We used fetal sheep chronically catheterized and infused either with vasopressin, vasopressin agonist (V2; dDAVP) or vasopressin antagonist (V1). Tracheal flow was measured during basal and infusions periods of 2 hours, monitoring fetal blood pressure, heart rate and blood pH and gases. Vasopressin and the V1 vasopressin antagonist caused a significant reduction in tracheal fluid flow, effect that was potentiated when both peptides were infused together. The V2 vasopressin agonist had no effect on the secretion of lung fluid. We concluded that vasopressin causes a significant inhibition of lung liquid secretion through a mechanism different to the activation of V1 and V2 receptors, and we propose the existence of other (s) kind of receptors (or receptors) for vasopressin that is (are) active during fetal life.
Assuntos
Arginina Vasopressina/farmacologia , Líquido Intracelular/metabolismo , Pulmão/metabolismo , Animais , Arginina Vasopressina/antagonistas & inibidores , Feto , Pulmão/efeitos dos fármacos , OvinosRESUMO
The neuropathological manifestations of AIDS in children vary widely and includes, among others: cerebral atrophy, basal ganglia calcification, corticospinal tract demyelinization, and HIV encephalomyelitis with multinucleated cells. The purpose of this work is to inform the postmortem CNS findings in 14 pediatric AIDS patients which were studied from January 1986 to February 1992, at the Hospital Infantil de México Federico Gómez. Basal ganglia vascular calcification, HIV multinucleated cells, and corticospinal tract demyelinization, were significantly less frequent (P < 0.01) in our patients than those informed in the literature. Opportunistic CNS infections found in our patients were produced by microorganisms commonly described in adults. We think that these differences may be explained because the majority of our patients acquired the infection trough blood transfusion at an age in which the CNS is fully developed. The pattern of HIV transmission in our country has been changing recently with an increase in the number of perinatal cases. We also think that in the near future we will observe a change in the neuropathological findings of our pediatric AIDS population.
Assuntos
Síndrome da Imunodeficiência Adquirida/patologia , Sistema Nervoso Central/patologia , Adolescente , Autopsia , Criança , Pré-Escolar , Humanos , Lactente , Estudos RetrospectivosRESUMO
The purpose of this paper is to inform the case of a 15 years old male patient who died as a consequence of acquired immunodeficiency syndrome (AIDS) complications. The postmortem examination showed a coronary lesion which, to the best of our knowledge, has not been previously described. This vasculopathy was restricted to the coronary arteries; myocardial changes similar to those described in AIDS-associated dilated cardiomyopathy were also present. The coronariopathy was indistinguishable from that described in the blood vessels of the brain in patients with AIDS-related cerebral arteriopathy. We also reviewed the autopsy material from another 14 children who died of AIDS, an in none of them exhibited similar changes in the coronary arteries. In addition we present the clinical findings and some theoretical considerations regarding the pathogenesis of the lesions.
Assuntos
Síndrome da Imunodeficiência Adquirida/complicações , Cardiomiopatias/complicações , Doença das Coronárias/complicações , Adolescente , Autopsia , Humanos , MasculinoRESUMO
Pressure-volume relationships and collagen and elastin contents were measured in the lungs of fetal sheep infused either with saline (n = 4), thyrotrophin-releasing hormone (TRH; n = 6), cortisol (n = 9) or TRH plus cortisol (n = 10) at 128 days of gestation (term = 149 days) for 7 days. Lung distensibility (V40 = 1.8 +/- 0.1 ml/g wet wt; mean +/- SD) and stability (V5 = 0.6 +/- 0.1) increased along with collagen (C) (10.1 +/- 2.7 micrograms/mg) and elastin (E) contents (128 +/- 35 ng/mg) in the animals infused with TRH plus cortisol and were significantly higher (p < 0.05) than those observed in TRH (V40 0.62 +/- 0.07; V5 0.32 +/- 0.04; C 3.53 +/- 1.3; E 38.2 +/- 8.3), cortisol (V4 0.66 +/- 0.6; V5 0.27 +/- 0.03; C 4.27 +/- 0.8; E 41.02 +/- 12.7) or saline infused fetuses (V40 0.40 +/- 0.1; V5 0.20 +/- 0.06; C 3.28 +/- 0.9; E 31.5 +/- 9.2). Plasma concentrations of prolactin (PRL), triiodothyronine (T3) and cortisol (F) were also higher in the group of fetuses infused with both hormones in comparison with the other groups. In fetuses treated with TRH plus cortisol, PRL (32 +/- 8.3 ng/ml) and T3 (308.3 +/- 36 micrograms/dl) were significantly higher than in those infused with cortisol alone (PRL 3.7 +/- 2.3; T3 128 +/- 30) or with saline (PRL 4.2 +/- 1.6; T3 < 5 micrograms/dl). In the group treated with TRH alone, PRL also increased significantly (37 +/- 6.4), but T3 increased only slightly (18 +/- 3.4).(ABSTRACT TRUNCATED AT 250 WORDS)