Background: In recent years, substantial progress has been made in understanding the organization of sequences in heterochromatin regions containing single-copy genes and transposable elements. However, the sequence and organization of tandem repeat DNA sequences, which are by far the majority fraction of D. melanogaster heterochromatin, are little understood.
View Article and Find Full Text PDFSecondary constrictions or 45S rDNA sites are commonly reported to be located mainly in the terminal regions of the chromosomes. This distribution has been assumed to be related to the existence of a "chromosome field" lying between the centromere and the telomere, an area in which certain cytogenetic events may predominantly occur. If this hypothesis is true this distribution should not be observed in holokinetic chromosomes, as they do not have a localized centromere.
View Article and Find Full Text PDFHum Vaccin
May 2011
Aims: Although oxidative stress participates in the etiopathogenesis of rheumatoid arthritis, its importance in this inflammatory disease has not been fully elucidated. In this study, we analyzed the relevance of the transcription factor Nrf2, master regulator of redox homeostasis, in the effector phase of an animal model of rheumatoid arthritis, using the transfer of serum from K/BxN transgenic mice to Nrf2(-/-) mice.
Results: Nrf2 deficiency accelerated the incidence of arthritis, and animals showed a widespread disease affecting both front and hind paws.
Microglial activation is an invariant feature of Alzheimer's disease (AD). It is noteworthy that cannabinoids are neuroprotective by preventing β-amyloid (Aβ)-induced microglial activation both in vitro and in vivo. On the other hand, the phytocannabinoid cannabidiol (CBD) has shown anti-inflammatory properties in different paradigms.
View Article and Find Full Text PDFObjective: Analysis and evaluation of a multidisciplinary approach, postoperative results and survival of a group of patients with resected pancreatic cancer after a multimodal therapy.
Design: DESCRIPTIVE, prospective and observational study.
Patients: Between January 2004 and December 2004, 124 patients with pancreatic cancer were evaluated.
Neuroinflammation is a key process in the neuropathogenesis of AIDS virus since as a result of the aberrant activation of the chemokine receptors (CXCR4, CX3CR1 and CR5) produces proinflammatory cytokine release by infected cells, increases microglial neurotoxicity and generates lipoperoxides and reactive oxygen species (ROS) that eventually damage the neuron. Moreover, the neurotoxin Tat produces dendritic loss by interacting with the low-density lipoprotein receptor (LRP) and also overstimulates N-methyl D-aspartate receptors (NMDA). Furthermore, the aberrant interaction of glycoprotein gp120 with the CXCR4 chemokine receptor causes caspase-3-dependent apoptosis (ceramide is also released) activating apoptotic proteins (p53 and retinoblastoma), which are part of the neurotoxic mechanisms associated to neuronal dysfunction in neuroAIDS.
View Article and Find Full Text PDFBackground: Prematurity is a recognized risk factor for morbidity and mortality following cardiac surgery. The purpose of this study was to examine short-term outcomes following cardiac surgery in premature neonates adhering to our institutional philosophy of supportive care allowing for weight gain and organ maturation.
Methods: Retrospective review of all neonates undergoing cardiac surgery from January 2002 to May 2008.
Current therapies for motor symptoms of Parkinson's disease (PD) are based on dopamine replacement. However, the disease progression remains unaffected, because of continuous dopaminergic neuron loss. Since oxidative stress is actively involved in neuronal death in PD, pharmacological targeting of the antioxidant machinery may have therapeutic value.
View Article and Find Full Text PDFRegulation of transcription factor Nrf2 (NF-E2-related factor 2) involves redox-sensitive proteasomal degradation via the E3 ubiquitin ligase Keap1/Cul3. However, Nrf2 is controlled by other mechanisms that have not yet been elucidated. We now show that glycogen synthase kinase 3 (GSK-3) phosphorylates a group of Ser residues in the Neh6 domain of mouse Nrf2 that overlap with an SCF/β-TrCP destruction motif (DSGIS, residues 334 to 338) and promotes its degradation in a Keap1-independent manner.
View Article and Find Full Text PDFp38α MAPK (mitogen-activated protein kinase) plays an important tumour suppressor role, which is mediated by both its negative effect on cell proliferation and its pro-apoptotic activity. Surprisingly, most tumour suppressor mechanisms co-ordinated by p38α have been reported to occur at the post-translational level. This contrasts with the important role of p38α in the regulation of transcription and the profound changes in gene expression that normally occur during tumorigenesis.
View Article and Find Full Text PDFIntroduction And Objectives: Transfemoral implantation of an Edwards SAPIEN (ES) or Medtronic CoreValve (MCV) aortic valve prosthesis is an alternative to surgical replacement for patients with severe aortic stenosis and a high surgical risk. The study's aim was to compare results obtained with these two devices.
Methods: Prospective observational study of transfemoral prosthesis implantation performed at our center.
In a clinical series, 10 consecutive female patients with intra-abdominal infections were successfully treated with natural orifice transluminal endoscopic surgery (NOTES) performed transvaginally. The surgery, which consisted of a hybrid NOTES procedure using a transvaginal approach, was performed on an emergency basis by the surgical team on call. The indications for surgery were acute cholecystitis (n = 6), acute appendicitis (n = 2), and pelvic peritonitis (n = 2) with intra-abdominal infection.
View Article and Find Full Text PDFThe MRN complex plays a central role in the DNA repair pathways of eukaryotic cells and takes part in many other processes, including cell cycle checkpoint signalling, meiosis, DNA replication and telomere maintenance. This complex is formed by the interaction of the products of the Mre11, Rad50 and Nbs1 genes. This paper reports the molecular characterization, expression and interactions of the Rad50 gene in several wheat species with different levels of ploidy.
View Article and Find Full Text PDFThe filamentous fungus Penicillium chrysogenum is well-known by its ability to synthesize β-lactam antibiotics as well as other secondary metabolites. Like other filamentous fungi, this microorganism is an excellent host for secretion of extracellular proteins because of the high capacity of its protein secretion machinery. In this work, we have characterized the extracellular proteome reference map of P.
View Article and Find Full Text PDFCurr Drug Targets
December 2010
Heme oxygenase-1 (HO-1), an enzyme degrading heme to carbon monoxide, free iron, and biliverdin, participates in the cell defence against oxidative stress and it has been speculated that it might be a new therapeutic target for neuroprotection. In this review, we discuss recent findings on the regulation of the HO-1 gene, Hmox1, in the brain with particular focus on the transcription factors Nrf2 and HIF-1. Functional polymorphisms in Hmox1 have been associated with high risk for Alzheimer's and Parkinson's disease.
View Article and Find Full Text PDFBackground: The transcription factor Nrf2 (NF-E2-related factor 2) and its target gene products, including heme oxygenase-1 (HO-1), elicit an antioxidant response that may have therapeutic value for Parkinson's disease (PD). However, HO-1 protein levels are increased in dopaminergic neurons of Parkinson's disease (PD) patients, suggesting its participation in free-iron deposition, oxidative stress and neurotoxicity. Before targeting Nrf2 for PD therapy it is imperative to determine if HO-1 is neurotoxic or neuroprotective in the basal ganglia.
View Article and Find Full Text PDFThe p38 MAPK (mitogen-activated protein kinase) signalling pathway allows cells to interpret a wide range of external signals and respond appropriately by generating a plethora of different biological effects. The diversity and specificity in cellular outcomes is achieved with an apparently simple linear architecture of the pathway, consisting of a core of three protein kinases acting sequentially. In the present review, we dissect the molecular mechanisms underlying p38 MAPK functions, with special emphasis on the activation and regulation of the core kinases, the interplay with other signalling pathways and the nature of p38 MAPK substrates as a source of functional diversity.
View Article and Find Full Text PDFThe chromatin-remodelling complex SNF2-related CBP activator protein (SRCAP) regulates chromatin structure in yeast by modulating the exchange of histone H2A for the H2A.Z variant. Here, we have investigated the contribution of H2A.
View Article and Find Full Text PDFAlthough extracellular purines may have both trophic and apoptotic functions in the brain depending on the targeted purine receptor and cell type, little is known about the role of specific purine receptors on neurons. In this study, we demonstrate that both ADP and its stable analogue 2-methyl-thio-ADP (2MeSADP) induce up-regulation of the cytoprotective protein heme oxygenase-1 (HO-1). Selective inhibition of 2MeSADP-responsive receptors P2Y(1) and P2Y(13) with their respective antagonists MRS2179 and MRS2211 and the use of pertussis toxin demonstrated a role of the purinergic P2Y(13) receptor in this response.
View Article and Find Full Text PDFSimple Sequence Repeats (SSRs) are known to be scattered and present in high number in eukaryotic genomes. We demonstrate that dye-labeled oligodeoxyribonucleotides with repeated mono-, di-, tri, or tetranucleotide motifs (15-20 nucleotides in length) have an unexpected ability to recognize SSR target sequences in non-denatured chromosomes. The results show that all these probes are able to invade chromosomes, independent of the size of the repeat motif, their nucleotide sequence, or their ability to form alternative B-DNA structures such as triplex DNA.
View Article and Find Full Text PDFAlthough oxidative stress is fundamental to the etiopathology of Parkinson disease, the signaling molecules involved in transduction after oxidant exposure to cell death are ill-defined, thus making it difficult to identify molecular targets of therapeutic relevance. We have addressed this question in human dopaminergic neuroblastoma SH-SY5Y cells exposed to the parkinsonian toxin paraquat (PQ). This toxin elicited a dose-dependent increase in reactive oxygen species and cell death that correlated with activation of ASK1 and the stress kinases p38 and JNK.
View Article and Find Full Text PDFNeural injury leads to inflammation and activation of microglia that in turn may participate in progression of neurodegeneration. The mechanisms involved in changing microglial activity from beneficial to chronic detrimental neuroinflammation are not known but reactive oxygen species (ROS) may be involved. We have addressed this question in Nrf2-knockout mice, with hypersensitivity to oxidative stress, submitted to daily inoculation of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) for 4 weeks.
View Article and Find Full Text PDFBackground: Clinical decisions on whether to follow up or remove small and medium congenital melanocytic nevi (SMCMN) in children have cost implications that have not been studied.
Objectives: To compare the costs of excision of SMCMN in children with lifelong follow-up in a tertiary center.
Methods And Materials: We elaborated models for the evaluation of the costs of excision and long-term follow-up.