Proc Natl Acad Sci U S A
August 2023
: Intradialytic hypotension (IDH) complicates 4 to 39.9% of hemodialysis (HD) sessions. Vessels' reactivity disturbances may be responsible for this complication.
View Article and Find Full Text PDFA forty-seven-year-old recipient in late period after kidney transplantation with chronic estimated glomerular filtration rate (eGFR) 30 mL/min/1.73 m, fully vaccinated against COVID-19 was diagnosed with SARS-CoV-2 infection in November 2021. After an initially mild course of the disease, he developed multiorgan failure requiring periodic respiratory and dialysis therapy.
View Article and Find Full Text PDFSpinal and bulbar muscular atrophy (SBMA) is a neurodegenerative and neuromuscular genetic disease caused by the expansion of a polyglutamine-encoding CAG tract in the androgen receptor (AR) gene. The AR is an important transcriptional regulator of the nuclear hormone receptor superfamily; its levels are regulated in many ways including by ubiquitin-dependent degradation. Ubiquitination is a post-translational modification (PTM) which plays a key role in both AR transcriptional activity and its degradation.
View Article and Find Full Text PDF(1) Background: The data from independent gene expression sources may be integrated for the purpose of molecular diagnostics of cancer. So far, multiple approaches were described. Here, we investigated the impacts of different data fusion strategies on classification accuracy and feature selection stability, which allow the costs of diagnostic tests to be reduced.
View Article and Find Full Text PDFDNA mismatch repair (MMR) is a highly conserved genome stabilizing pathway that corrects DNA replication errors, limits chromosomal rearrangements, and mediates the cellular response to many types of DNA damage. Counterintuitively, MMR is also involved in the generation of mutations, as evidenced by its role in causing somatic triplet repeat expansion in Huntington's disease (HD) and other neurodegenerative disorders. In this review, we discuss the current state of mechanistic knowledge of MMR and review the roles of key enzymes in this pathway.
View Article and Find Full Text PDFPolyglutamine (polyQ) diseases are devastating, slowly progressing neurodegenerative conditions caused by expansion of polyQ-encoding CAG repeats within the coding regions of distinct, unrelated genes. In spinal and bulbar muscular atrophy (SBMA), polyQ expansion within the androgen receptor (AR) causes progressive neuromuscular toxicity, the molecular basis of which is unclear. Using quantitative proteomics, we identified changes in the AR interactome caused by polyQ expansion.
View Article and Find Full Text PDFMembranous nephropathy (MN) is one of the most common causes of nephrotic syndrome in non-diabetic adult patients; 75% of adult patients with MN suffer from primary idiopathic membranous nephropathy (IMN). The treatment of choice is immunosuppressive therapy, with a combination of steroids and cyclophosphamide (CYF) or chlorambucil or, as second-line treatment, calcineurin inhibitors (CNIs). One of the main concerns associated with the usage of CNIs is their potential to induce nephrotoxicity.
View Article and Find Full Text PDFSpinal and bulbar muscular atrophy (SBMA) is a neuromuscular disease caused by polyglutamine (polyQ) expansion in the androgen receptor (AR). Prior studies have highlighted the importance of AR nuclear localization in SBMA pathogenesis; therefore, in this study, we sought to determine the role of AR nuclear export in the pathological manifestations of SBMA. We demonstrate here that the nuclear export of polyQ-expanded AR is impaired, even prior to the formation of intranuclear inclusions of aggregated AR.
View Article and Find Full Text PDFBackground: Here, we present an R package for entropy/variability analysis that facilitates prompt and convenient data extraction, manipulation and visualization of protein features from multiple sequence alignments. BALCONY can work with residues dispersed across a protein sequence and map them on the corresponding alignment of homologous protein sequences. Additionally, it provides several entropy and variability scores that indicate the conservation of each residue.
View Article and Find Full Text PDFMotivation: The identification and tracking of molecules which enter active site cavity requires screening the positions of thousands of single molecules along several thousand molecular dynamic steps. To fill the existing gap between tools searching for tunnels and pathways and advanced tools employed for accelerated water flux investigations, we have developed AQUA-DUCT.
Results: AQUA-DUCT is an easy-to-use tool that facilitates analysis of the behaviour of molecules that penetrate any selected region in a protein.
Spinal and bulbar muscular atrophy (SBMA) is a neurodegenerative disease caused by a polyglutamine expansion in the androgen receptor (AR) and is associated with misfolding and aggregation of the mutant AR. We investigated the role of an interdomain interaction between the amino (N)-terminal FxxLF motif and carboxyl (C)-terminal AF-2 domain in a mouse model of SBMA. Male transgenic mice expressing polyQ-expanded AR with a mutation in the FxxLF motif (F23A) to prevent the N/C interaction displayed substantially improved motor function compared with N/C-intact AR-expressing mice and showed reduced pathological features of SBMA.
View Article and Find Full Text PDFProteolysis of polyglutamine-expanded proteins is thought to be a required step in the pathogenesis of several neurodegenerative diseases. The accepted view for many polyglutamine proteins is that proteolysis of the mutant protein produces a "toxic fragment" that induces neuronal dysfunction and death in a soluble form; toxicity of the fragment is buffered by its incorporation into amyloid-like inclusions. In contrast to this view, we show that, in the polyglutamine disease spinal and bulbar muscular atrophy, proteolysis of the mutant androgen receptor (AR) is a late event.
View Article and Find Full Text PDFDNA mismatch repair is a conserved antimutagenic pathway that maintains genomic stability through rectification of DNA replication errors and attenuation of chromosomal rearrangements. Paradoxically, mutagenic action of mismatch repair has been implicated as a cause of triplet repeat expansions that cause neurological diseases such as Huntington disease and myotonic dystrophy. This mutagenic process requires the mismatch recognition factor MutSβ and the MutLα (and/or possibly MutLγ) endonuclease, and is thought to be triggered by the transient formation of unusual DNA structures within the expanded triplet repeat element.
View Article and Find Full Text PDFMutLα endonuclease can be activated on covalently continuous DNA that contains a MutSα- or MutSβ-recognizable lesion and a helix perturbation that supports proliferating cell nuclear antigen (PCNA) loading by replication factor C, providing a potential mechanism for triggering mismatch repair on nonreplicating DNA. Because mouse models for somatic expansion of disease-associated (CAG)n/(CTG)n triplet repeat sequences have implicated both MutSβ and MutLα and have suggested that expansions can occur in the absence of replication, we have asked whether an extrahelical (CAG)n or (CTG)n element is sufficient to trigger MutLα activation. (CAG)n and (CTG)n extrusions in relaxed closed circular DNA do in fact support MutSβ-, replication factor C-, and PCNA-dependent activation of MutLα endonuclease, which can incise either DNA strand.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
September 2010
MutLα (MLH1-PMS2) is a latent endonuclease that is activated in a mismatch-, MutSα-, proliferating cell nuclear antigen (PCNA)-, replication factor C (RFC)-, and ATP-dependent manner, with nuclease action directed to the heteroduplex strand that contains a preexisting break. RFC depletion experiments and use of linear DNAs indicate that RFC function in endonuclease activation is limited to PCNA loading. Whereas nicked circular heteroduplex DNA is a good substrate for PCNA loading and for endonuclease activation on the incised strand, covalently closed, relaxed circular DNA is a poor substrate for both reactions.
View Article and Find Full Text PDFMutSbeta (MSH2-MSH3) mediates repair of insertion-deletion heterologies but also triggers triplet repeat expansions that cause neurological diseases. Like other DNA metabolic activities, MutSbeta interacts with proliferating cell nuclear antigen (PCNA) via a conserved motif (QXX(L/I)XXFF). We demonstrate that MutSbeta-PCNA complex formation occurs with an affinity of approximately 0.
View Article and Find Full Text PDFWe have examined function of the bacterial beta replication clamp in the different steps of methyl-directed DNA mismatch repair. The mismatch-, MutS-, and MutL-dependent activation of MutH is unaffected by the presence or orientation of loaded beta clamp on either 3' or 5' heteroduplexes. Similarly, beta is not required for 3' or 5' mismatch-provoked excision when scored in the presence of gamma complex or in the presence of gamma complex and DNA polymerase III core components.
View Article and Find Full Text PDFThe objective of this study was to estimate and analyze the costs of treating children with HIV/AIDS at a university hospital in São Paulo, Brazil. The study collected and analyzed data from 291 medical records of children treated at the hospital as of March 2002. The costs of treatment were estimated for each category of patient (exposed and infected) and severity, based on the quantity of inputs and procedures used in treating each child, based on the cost accounting system used at the hospital.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
July 2007
The hemimethylated d(GATC) sequence that directs Escherichia coli mismatch repair can reside on either side of a mismatch at a separation distance of 1,000 bp or more. Initiation of repair involves the mismatch-, MutS-, and MutL-dependent activation of MutH endonuclease, which incises the unmethylated strand at the d(GATC) sequence, with the ensuing strand break serving as the loading site for the appropriate 3'-to-5' or 5'-to-3' excision system. However, the mechanism responsible for the coordinated recognition of the mismatch and a hemimodified d(GATC) site is uncertain.
View Article and Find Full Text PDFA new Escherichia coli host/vector system has been engineered to allow tight and uniform modulation of gene expression and gamma origin (ori) plasmid copy number. Regulation of gamma ori plasmid copy number is achieved through arabinose-inducible expression of the necessary Rep protein, pi, whose gene was integrated into the chromosome of the host strain under control of the P(BAD) promoter. gamma ori replication can be uniformly modulated over 100-fold by changing the concentration of l-arabinose in the growth medium.
View Article and Find Full Text PDFObjective: The increasing number of women with AIDS in the state of São Paulo has lead to the implementation of a series of measures to reduce mother-to-child HIV transmission. The objective of this study was to evaluate these measures' deficiencies regarding coverage and quality of prenatal care in some HIV reference services in the state of São Paulo.
Methods: All HIV-positive women, aged 18 years or more, who gave birth in 1998 were interviewed when they came for a visit with an infectologist or a pediatrician in three cities (São Paulo, Santos and São José do Rio Preto) of the state of São Paulo.
The commonly applied division of hypoglycemia into reactive and non-reactive one is too general and often times insufficient in clinical practice. The authors of this study presented a classification based on the clinical profile of patients with hypoglycemia. They also recommended patterns allowing proper diagnostic procedure in each classified group.
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