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1.
J Clin Invest ; 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38888968

RESUMO

Tolerance of mouse kidney allografts arises in grafts that develop regulatory Tertiary Lymphoid Organs (rTLOs). scRNAseq data and adoptive transfer of alloreactive T cells post-transplant showed that cytotoxic CD8+ T cells are reprogrammed within the accepted graft to an exhausted/regulatory-like phenotype mediated by IFN-γ. Establishment of rTLOs was required since adoptive transfer of alloreactive T cells prior to transplantation results in kidney allograft rejection. Despite intragraft CD8+ cells with a regulatory phenotype, they were not essential for the induction and maintenance of kidney allograft tolerance since renal allotransplantation into CD8 KO recipients resulted in acceptance and not rejection. Analysis of scRNAseq data from allograft kidneys and malignant tumors identified similar regulatory-like cell types within the T cell clusters and trajectory analysis showed that cytotoxic CD8+ T cells are reprogrammed into an exhausted/regulatory-like phenotype intratumorally. Induction of cytotoxic CD8+ T cell dysfunction of infiltrating cells appears to be a beneficial mechanistic pathway that protects the kidney allotransplant from rejection through a process we call "defensive tolerance." This pathway has implications for our understanding of allotransplant tolerance and tumor resistance to host immunity.

2.
J Neurol Surg B Skull Base ; 85(3): 241-246, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38721368

RESUMO

Objectives Iatrogenic injury to the internal carotid artery (ICA) is one of the most catastrophic complications of endoscopic sinus and skull base surgery. Previous research has shown that packing with a crushed muscle graft at the injury site can be an effective management technique to control bleeding and prevent the need for ICA sacrifice. Here, we describe a novel and readily available repair donor site-an autologous lateral tongue muscle patch. Design Three representative cases of a successful repair of ICA injuries using a lateral tongue muscle patch are included in this study. The graft measured approximately 2 × 3 cm and was taken from the lateral intrinsic tongue musculature. We describe the harvest of the graft, its advantages, and the details of operative repair. Results The lateral tongue provides a large and readily accessible source of muscle within the surgical field that can be quickly harvested during an endoscopic procedure. For the first case, an expanding parasellar ICA pseudoaneurysm was managed with a tongue muscle patch and nasal packing. In the second case, a cavernous ICA injury was sustained during craniopharyngioma resection. Case three involved an ICA injury during endonasal debridement of invasive fungal rhinosinusitis. None of the patients required embolization or neurovascular stenting. Postoperative angiograms and serial computed tomography angiograms showed complete resolution of the pseudoaneurysm, and the patients continued to do well at least 1 year after repair. Conclusion Lateral tongue muscle graft is an effective and efficient method to manage ICA injuries during endoscopic endonasal surgery. Advantages include the speed of harvest, donor site being readily accessible in the surgical field, and low donor site morbidity. It should be added to the repertoire of possible donor sites for addressing catastrophic sinonasal bleeding.

3.
Otolaryngol Head Neck Surg ; 169(2): 397-405, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-36807365

RESUMO

OBJECTIVE: Classical management of complex fractures involving the frontal sinus outflow tract (FSOT) favors obliteration or cranialization to avoid delayed complications. We aim to exhibit success with a novel application of balloon sinuplasty and frontal stenting in the management of complex injuries disrupting the FSOT, which might have otherwise required more invasive interventions. STUDY DESIGN: Retrospective review. SETTING: Single institution, level 1 trauma center. METHODS: Retrospective review of patients presenting to a level 1 trauma center with fractures involving the FSOT. Outcomes include patency of the FSOT on imaging and endoscopy, rate of complications, degree of residual tabular displacement, and need for revision surgery. RESULTS: Twenty-five patients met inclusion criteria, with complete FSOT obstruction seen in all cases on computed tomography. All patients underwent balloon sinuplasty with frontal sinus stenting; 48% underwent concurrent anterior table repair, and 36% open repair of nasoorbitoethmoid complex fractures. The mean follow-up length was 13.9 months, at which time 91.3% of patients demonstrated radiographic and endoscopic FSOT patency. No residual sinus opacification or pneumocephalus was observed. CONCLUSION: Balloon sinuplasty with frontal sinus stenting is a straightforward and minimally invasive technique that can create a safe sinus in complex fractures disrupting the FSOT while avoiding the need for more invasive procedures.


Assuntos
Seio Frontal , Fraturas Cranianas , Humanos , Seio Frontal/diagnóstico por imagem , Seio Frontal/cirurgia , Seio Frontal/lesões , Endoscopia/métodos , Fraturas Cranianas/diagnóstico por imagem , Fraturas Cranianas/cirurgia , Estudos Retrospectivos , Reoperação
4.
Intensive Care Med ; 48(9): 1133-1143, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35831640

RESUMO

PURPOSE: Early accurate diagnosis of infection ± organ dysfunction (sepsis) remains a major challenge in clinical practice. Utilizing effective biomarkers to identify infection and impending organ dysfunction before the onset of clinical signs and symptoms would enable earlier investigation and intervention. To our knowledge, no prior study has specifically examined the possibility of pre-symptomatic detection of sepsis. METHODS: Blood samples and clinical/laboratory data were collected daily from 4385 patients undergoing elective surgery. An adjudication panel identified 154 patients with definite postoperative infection, of whom 98 developed sepsis. Transcriptomic profiling and subsequent RT-qPCR were undertaken on sequential blood samples taken postoperatively from these patients in the three days prior to the onset of symptoms. Comparison was made against postoperative day-, age-, sex- and procedure- matched patients who had an uncomplicated recovery (n =151) or postoperative inflammation without infection (n =148). RESULTS: Specific gene signatures optimized to predict infection or sepsis in the three days prior to clinical presentation were identified in initial discovery cohorts. Subsequent classification using machine learning with cross-validation with separate patient cohorts and their matched controls gave high Area Under the Receiver Operator Curve (AUC) values. These allowed discrimination of infection from uncomplicated recovery (AUC 0.871), infectious from non-infectious systemic inflammation (0.897), sepsis from other postoperative presentations (0.843), and sepsis from uncomplicated infection (0.703). CONCLUSION: Host biomarker signatures may be able to identify postoperative infection or sepsis up to three days in advance of clinical recognition. If validated in future studies, these signatures offer potential diagnostic utility for postoperative management of deteriorating or high-risk surgical patients and, potentially, other patient populations.


Assuntos
Sepse , Transcriptoma , Biomarcadores , Humanos , Inflamação/complicações , Insuficiência de Múltiplos Órgãos , Complicações Pós-Operatórias/diagnóstico
5.
Ecotoxicol Environ Saf ; 233: 113323, 2022 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-35183811

RESUMO

Molecular docking is a widely used method to predict the binding modes of small-molecule ligands to the target binding site. However, it remains a challenge to identify the correct binding conformation and the corresponding binding affinity for a series of structurally similar ligands, especially those with weak binding. An understanding of the various relative attributes of popular docking programs is required to ensure a successful docking outcome. In this study, we systematically compared the performance of three popular docking programs, Autodock, Autodock Vina, and Surflex-Dock for a series of structurally similar weekly binding flavonoids (22) binding to the estrogen receptor alpha (ERα). For these flavonoids-ERα interactions, Surflex-Dock showed higher accuracy than Autodock and Autodock Vina. The hydrogen bond overweighting by Autodock and Autodock Vina led to incorrect binding results, while Surflex-Dock effectively balanced both hydrogen bond and hydrophobic interactions. Moreover, the selection of initial receptor structure is critical as it influences the docking conformations of flavonoids-ERα complexes. The flexible docking method failed to further improve the docking accuracy of the semi-flexible docking method for such chemicals. In addition, binding interaction analysis revealed that 8 residues, including Ala350, Glu353, Leu387, Arg394, Phe404, Gly521, His524, and Leu525, are the key residues in ERα-flavonoids complexes. This work provides reference for assessing molecular interactions between ERα and flavonoid-like chemicals and provides instructive information for other environmental chemicals.


Assuntos
Receptor alfa de Estrogênio , Sítios de Ligação , Flavonoides , Ligantes , Simulação de Acoplamento Molecular
6.
Br J Anaesth ; 128(2): e200-e205, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34794766

RESUMO

On March 4, 2018, two casualties collapsed on a park bench in Salisbury, Wiltshire, UK. They were later discovered to have been the victims of an attempted murder using the Soviet-era Novichok class of nerve agent. The casualties, along with three further critically ill patients, were cared for in Salisbury District Hospital's Intensive Care Unit. Before the COVID-19 pandemic, the Salisbury and Amesbury incidents were the longest-running major incidents in the history of the UK National Health Service. This narrative review seeks to reflect on the lessons learned from these chemical incidents, with a particular focus on hospital and local organisational responses.


Assuntos
Vazamento de Resíduos Químicos/prevenção & controle , Serviços Médicos de Emergência/métodos , Incidentes com Feridos em Massa/prevenção & controle , Agentes Neurotóxicos/intoxicação , Organofosfatos/toxicidade , Equipamento de Proteção Individual , Fatores Biológicos/intoxicação , Humanos , Incidência , Liberação Nociva de Radioativos/prevenção & controle , Saúde Radiológica , Reino Unido/epidemiologia
7.
Mol Cell ; 81(14): 2989-3006.e9, 2021 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-34197737

RESUMO

Stalled DNA replication fork restart after stress as orchestrated by ATR kinase, BLM helicase, and structure-specific nucleases enables replication, cell survival, and genome stability. Here we unveil human exonuclease V (EXO5) as an ATR-regulated DNA structure-specific nuclease and BLM partner for replication fork restart. We find that elevated EXO5 in tumors correlates with increased mutation loads and poor patient survival, suggesting that EXO5 upregulation has oncogenic potential. Structural, mechanistic, and mutational analyses of EXO5 and EXO5-DNA complexes reveal a single-stranded DNA binding channel with an adjacent ATR phosphorylation motif (T88Q89) that regulates EXO5 nuclease activity and BLM binding identified by mass spectrometric analysis. EXO5 phospho-mimetic mutant rescues the restart defect from EXO5 depletion that decreases fork progression, DNA damage repair, and cell survival. EXO5 depletion furthermore rescues survival of FANCA-deficient cells and indicates EXO5 functions epistatically with SMARCAL1 and BLM. Thus, an EXO5 axis connects ATR and BLM in directing replication fork restart.


Assuntos
Proteínas Mutadas de Ataxia Telangiectasia/genética , Replicação do DNA/genética , DNA/genética , Exonucleases/genética , Instabilidade Genômica/genética , RecQ Helicases/genética , Linhagem Celular , Linhagem Celular Tumoral , Dano ao DNA/genética , DNA Helicases/genética , Análise Mutacional de DNA/métodos , Reparo do DNA/genética , Proteínas de Ligação a DNA/genética , Células HEK293 , Células HeLa , Humanos , Mutação/genética , Oncogenes/genética , Fosforilação/genética , Regulação para Cima/genética
8.
Indian Dermatol Online J ; 12(1): 84-89, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33768027

RESUMO

BACKGROUND AND AIMS: Cutaneous lesions are the defining features of several neurocutaneous syndromes like neurofibromatosis1(NF1), tuberous sclerosis complex (TSC), and Sturge Weber syndrome to name a few. With this background, we explored the possibility of identifying congenital and nevoid cutaneous markers that may help in the early recognition of autism spectrum disorders (ASD) in Indian children. The objective of this study was to measure the strength of association between congenital and nevoid cutaneous lesions and ASD among Indian children. METHODS: A case-control study was conducted from January 2018 to June 2018. 132 children (18 months-16 years of age) with ASD and equal number of age and sex-matched children without autism were studied. Diagnosis of ASD was based on DSM-5 criteria. All the children were examined for cutaneous lesions with special attention to nevoid and congenital conditions. The strength of association was measured using the diagnostic odds ratio (OR). RESULTS: The prevalence of congenital and nevoid lesions were higher in ASD group (OR = 3.12, P = 0.0001). Among them, pigmentary mosaicism of hyperpigmented type (OR = 2.76, P = 0.02) and café-au-lait macules (CALMs) (OR = 2.40, P = 0.001) were the most prevalent with hyperpigmented pigmentary mosaicism showing a higher association with autism. Atypical CALMs (OR = 2, P = 0.09) were also more prevalent in the ASD group though not statistically significant. CONCLUSION: The presence of hyperpigmented pigmentary mosaicism and CALMs warrant closer surveillance by the caregivers and physicians for evolving features of autism. Larger multicentric studies are required to validate these findings.

9.
Facial Plast Surg Aesthet Med ; 23(2): 103-109, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32779939

RESUMO

Importance: Symptomatic septal perforations are often difficult to manage and can have a significant impact on patient quality of life. Available surgical techniques for repair have demonstrated a varying rate of success, presenting a need for reliable interventions targeting symptom control. Objectives: To describe the modified surgical technique here termed septal perfoplasty. To demonstrate that creation of favorable septal perforation characteristics is effective in managing symptoms and improving patient quality of life. Design, Setting, and Participants: A retrospective review of the medical record was performed of patients who underwent the procedure of interest between July 1, 2006 and October 1, 2019 at Vanderbilt University Medical Center. All patients with symptomatic septal perforation who underwent septal perfoplasty within the timeframe reviewed were included. Septal perfoplasty was standardly performed in combination with turbinate reduction in all cases. This was combined with other indicated procedures for chronic sinusitis, repair of vestibular stenosis or nasal deformity. Main Outcomes and Measures: Creation of a well-mucosalized septal perforation, combined with patient-reported acceptable symptom control, was the primary outcome. Secondary outcomes include time to resolution, duration of follow-up, postsurgical complications, and need for further intervention. Results: Twenty patients (70% female; mean [range] age, 45.8 [15-72] years) underwent septal perfoplasty over the course of 13 years. The most common etiology of perforation was trauma (40%), presenting symptom was crusting (95%), and size of perforation repaired was large (60%). Mean follow-up was 37.6 months (range, 1-153 months). Overall, favorable perforation characteristics were created in 95% of cases by the first postoperative appointment. Acceptable symptomatic control was achieved in 18 out of 20 patients (90%), with a median time to improvement of 66 days. Eight patients required additional surgery to address chronic sinusitis or vestibular stenosis. Two patients experienced postoperative infections, treated conservatively with antibiotics. Conclusion and Relevance: Septal perfoplasty is a safe, simple, and effective method for management of symptomatic nasal septal perforation, which provides an alternative to more complicated interventions with comparable rates of symptomatic resolution. This procedure should particularly be considered for patients in which difficult repair is anticipated.


Assuntos
Perfuração do Septo Nasal/cirurgia , Septo Nasal/cirurgia , Rinoplastia/métodos , Adolescente , Adulto , Idoso , Endoscopia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Perfuração do Septo Nasal/diagnóstico por imagem , Septo Nasal/diagnóstico por imagem , Medidas de Resultados Relatados pelo Paciente , Estudos Retrospectivos , Resultado do Tratamento , Adulto Jovem
10.
Int J Comput Assist Radiol Surg ; 15(1): 69-74, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31292925

RESUMO

PURPOSE: This short communication describes experimental evaluation of a new granular jamming cap (GJC) recently introduced in Wellborn et al. (Int J Comput Assist Radiol Surg 12(6):1069-1077, 2017). The contributions beyond [8] are (1) to evaluate accuracy across multiple human subjects, and (2) to determine how much of the accuracy improvement is attributable to improved fiducial marker arrangement alone, and how much is due to granular jamming. The motivation for this GJC is to improve the accuracy of image-guidance interfaces in transnasal skull base surgery. Accuracy depends on a rigid connection between tracked fiducial markers and the patient. By molding itself to the unique contours of the individual patient's head and then solidifying, the GJC can firmly attach fiducial markers to a patient, increasing accuracy in the presence of disturbances. METHODS: A multi-subject study ([Formula: see text]) was performed to evaluate the accuracy of the GJC compared to a clinically used headband-based fixation device, in the presence of simulated accidental bumping (light force and impact events) that could occur in a real-world operating room. RESULTS: The GJC reduced the average target registration error at the pituitary gland by 66% in our force experiments and 78% in our impact experiments, which were statistically significant reductions ([Formula: see text]). Maximum target registration error was similarly reduced by 55% and 78% in the same two perturbation tests. CONCLUSION: The GJC increases the accuracy of transnasal image-guidance under force and impact perturbations by more firmly, yet non-invasively, attaching fiducial markers to the patient. We find that granular jamming provides accuracy improvement beyond that associated with improved fiducial marker arrangement.


Assuntos
Endoscopia/métodos , Marcadores Fiduciais/normas , Processamento de Imagem Assistida por Computador , Procedimentos Neurocirúrgicos/métodos , Cirurgia Assistida por Computador/instrumentação , Desenho de Equipamento , Humanos , Masculino , Reprodutibilidade dos Testes
11.
PLoS One ; 14(10): e0223001, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31596845

RESUMO

BACKGROUND: Malnutrition among children is one of the most pressing health concerns middle- and low-income countries face today, particularly those in Sub-Saharan Africa and South Asia. Early-life malnutrition has been shown to affect long-term health and income. One hypothesized channel linking early-life malnutrition and long-term outcomes is cognitive development. However, there is limited empirical evidence on the relationship between nutritional status and cognitive achievement in middle childhood. STUDY DESIGN: As part of the South India Community Health Study (SICHS), we collected educational attainment and anthropometric data from 1,194 children in rural Vellore district of Tamil Nadu, India, and assessed their math and reading skills. We analyzed the relationship between continuous and binary anthropometric measures of nutritional status and three measures of cognitive achievement (reading, math, and grade level), adjusting for potential confounders, using a regression framework. RESULTS: Lower height-for-age and weight-for-age and their corresponding binary measures (stunting, underweight) were associated with lower reading scores, lower math scores, and lower grade level, with the exception of the association between weight-for-age and reading, which was marginally significant. A stunted child had one-third of a grade disadvantage compared to a non-stunted counterpart, whereas an underweight child had one-fourth of a grade disadvantage compared to a non-underweight counterpart. Lower BMI-for-age was associated with grade level and marginally associated with lower math scores, and its binary measure (thinness) was marginally associated with lower math scores. CONCLUSIONS: Acute and chronic malnutrition in middle childhood were negatively associated with math scores, reading scores, and educational attainment. Our study provides new evidence that cognitive achievement during middle childhood could be an important mechanism underlying the association between early-life malnutrition and long-term wellbeing.


Assuntos
Logro , Cognição , Escolaridade , Estado Nutricional , População Rural , Criança , Feminino , Humanos , Índia/epidemiologia , Masculino , Modelos Teóricos , Análise Multivariada , Magreza/epidemiologia
12.
Proc Natl Acad Sci U S A ; 115(35): 8793-8798, 2018 08 28.
Artigo em Inglês | MEDLINE | ID: mdl-30104346

RESUMO

Collapsed replication forks, which are a major source of DNA double-strand breaks (DSBs), are repaired by sister chromatid recombination (SCR). The Mre11-Rad50-Nbs1 (MRN) protein complex, assisted by CtIP/Sae2/Ctp1, initiates SCR by nucleolytically resecting the single-ended DSB (seDSB) at the collapsed fork. The molecular architecture of the MRN intercomplex, in which zinc hooks at the apices of long Rad50 coiled-coils connect two Mre112-Rad502 complexes, suggests that MRN also structurally assists SCR. Here, Rad50 ChIP assays in Schizosaccharomyces pombe show that MRN sequentially localizes with the seDSB and sister chromatid at a collapsed replication fork. Ctp1, which has multivalent DNA-binding and DNA-bridging activities, has the same DNA interaction pattern. Provision of an intrachromosomal repair template alleviates the nonnucleolytic requirement for MRN to repair the broken fork. Mutations of zinc-coordinating cysteines in the Rad50 hook severely impair SCR. These data suggest that the MRN complex facilitates SCR by linking the seDSB and sister chromatid.


Assuntos
Cromátides/metabolismo , Cromossomos Fúngicos/metabolismo , Reparo do DNA/fisiologia , DNA Fúngico/metabolismo , Exodesoxirribonucleases/metabolismo , Complexos Multiproteicos/metabolismo , Proteínas de Schizosaccharomyces pombe/metabolismo , Schizosaccharomyces/metabolismo , Cromátides/genética , Cromossomos Fúngicos/genética , Replicação do DNA/fisiologia , DNA Fúngico/genética , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Exodesoxirribonucleases/genética , Complexos Multiproteicos/genética , Mutação , Schizosaccharomyces/genética , Proteínas de Schizosaccharomyces pombe/genética
13.
PLoS Genet ; 14(8): e1007595, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-30148840

RESUMO

Hexavalent chromium [Cr(VI)] damages DNA and causes cancer, but it is unclear which DNA damage responses (DDRs) most critically protect cells from chromate toxicity. Here, genome-wide quantitative functional profiling, DDR measurements and genetic interaction assays in Schizosaccharomyces pombe reveal a chromate toxicogenomic profile that closely resembles the cancer chemotherapeutic drug camptothecin (CPT), which traps Topoisomerase 1 (Top1)-DNA covalent complex (Top1cc) at the 3' end of single-stand breaks (SSBs), resulting in replication fork collapse. ATR/Rad3-dependent checkpoints that detect stalled and collapsed replication forks are crucial in Cr(VI)-treated cells, as is Mus81-dependent sister chromatid recombination (SCR) that repairs single-ended double-strand breaks (seDSBs) at broken replication forks. Surprisingly, chromate resistance does not require base excision repair (BER) or interstrand crosslink (ICL) repair, nor does co-elimination of XPA-dependent nucleotide excision repair (NER) and Rad18-mediated post-replication repair (PRR) confer chromate sensitivity in fission yeast. However, co-elimination of Tdp1 tyrosyl-DNA phosphodiesterase and Rad16-Swi10 (XPF-ERCC1) NER endonuclease synergistically enhances chromate toxicity in top1Δ cells. Pnk1 polynucleotide kinase phosphatase (PNKP), which restores 3'-hydroxyl ends to SSBs processed by Tdp1, is also critical for chromate resistance. Loss of Tdp1 ameliorates pnk1Δ chromate sensitivity while enhancing the requirement for Mus81. Thus, Tdp1 and PNKP, which prevent neurodegeneration in humans, repair an important class of Cr-induced SSBs that collapse replication forks.


Assuntos
Quebras de DNA de Cadeia Simples , Replicação do DNA , Diester Fosfórico Hidrolases/metabolismo , Proteínas de Schizosaccharomyces pombe/metabolismo , Schizosaccharomyces/genética , Camptotecina/farmacologia , Ciclo Celular/efeitos dos fármacos , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Quinase 1 do Ponto de Checagem/genética , Quinase do Ponto de Checagem 2/efeitos dos fármacos , Cromatos/toxicidade , Cromátides/metabolismo , Reparo do DNA/efeitos dos fármacos , DNA Topoisomerases Tipo I/genética , DNA Topoisomerases Tipo I/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Farmacorresistência Fúngica , Endonucleases/genética , Endonucleases/metabolismo , Humanos , Diester Fosfórico Hidrolases/genética , Polinucleotídeo 5'-Hidroxiquinase/genética , Polinucleotídeo 5'-Hidroxiquinase/metabolismo , Schizosaccharomyces/metabolismo , Proteínas de Schizosaccharomyces pombe/efeitos dos fármacos , Proteínas de Schizosaccharomyces pombe/genética
14.
Mol Biol Cell ; 29(11): 1389-1399, 2018 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-29851556

RESUMO

The Mre11-Rad50-Nbs1 (MRN) protein complex and ATM/Tel1 kinase protect genome integrity through their functions in DNA double-strand break (DSB) repair, checkpoint signaling, and telomere maintenance. Nbs1 has a conserved C-terminal motif that binds ATM/Tel1, but the full extent and significance of ATM/Tel1 interactions with MRN are unknown. Here, we show that Tel1 overexpression bypasses the requirement for Nbs1 in DNA damage signaling and telomere maintenance. These activities require Mre11-Rad50, which localizes to DSBs and bind Tel1 in the absence of Nbs1. Fusion of the Tel1-binding motif of Nbs1 to Mre11 is sufficient to restore Tel1 signaling in nbs1Δ cells. Tel1 overexpression does not restore Tel1 signaling in cells carrying the rad50-I1192W mutation, which impairs the ability of Mre11-Rad50 to form the ATP-bound closed conformation. From these findings, we propose that Tel1 has a high-affinity interaction with the C-terminus of Nbs1 and a low-affinity association with Mre11-Rad50, which together accomplish efficient localization and activation of Tel1 at DSBs and telomeres.


Assuntos
Quebras de DNA de Cadeia Dupla , Proteínas de Schizosaccharomyces pombe/metabolismo , Schizosaccharomyces/metabolismo , Telômero/metabolismo , Trifosfato de Adenosina/metabolismo , Mutação/genética , Ligação Proteica , Proteínas de Schizosaccharomyces pombe/química , Transdução de Sinais
15.
Otolaryngol Head Neck Surg ; 158(5): 952-960, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29405885

RESUMO

Objective To determine the factors associated with intra- and postoperative cerebrospinal fluid (CSF) leaks in setting of endoscopic transsphenoidal sellar surgery. Study Design Retrospective cohort. Setting Tertiary referral center. Subjects and Methods This study included 806 patients who underwent endoscopic transsphenoidal sellar surgery between 2004 and 2016. The associations between CSF leaks (intra- and postoperative) and patient demographics, medical history, tumor characteristics, and intraoperative repair techniques were analyzed. Results In sum, 205 (25.4%) patients had a CSF leak: 188 (23.3%) intraoperative leaks and 38 (4.7%) postoperative leaks. Twenty-one (2.6%) patients had postoperative leaks after having repair of an intraoperative leak; 55% of patients with a postoperative leak had an intraoperative leak repaired. On multivariate analysis, body mass index (BMI), hydrocephalus, suprasellar extension, and craniopharyngioma significantly predicted intraoperative CSF leaks, while only BMI and hydrocephalus predicted postoperative CSF leaks. Patients having septal flap repairs of CSF leaks had a higher postoperative leak rate relative to other repair techniques (odds ratio, 6.37; P = .013). Rigid reconstruction did not correlate with leaks. Conclusion For this large cohort of patients undergoing endoscopic transsphenoidal sellar surgery, BMI and hydrocephalus were identified as predictors of postoperative CSF leaks, including those occurring after repair of intraoperative leak. These variables may put stress on the surgical repair of sellar defects, and consideration of these risk factors may help counsel patients and guide perioperative decision making in regard to repair strategies and CSF diversion techniques.


Assuntos
Vazamento de Líquido Cefalorraquidiano/etiologia , Endoscopia/efeitos adversos , Complicações Intraoperatórias/etiologia , Neoplasias Hipofisárias/cirurgia , Complicações Pós-Operatórias/etiologia , Adulto , Idoso , Índice de Massa Corporal , Feminino , Humanos , Hidrocefalia/complicações , Masculino , Pessoa de Meia-Idade , Neoplasias Hipofisárias/complicações , Neoplasias Hipofisárias/patologia , Estudos Retrospectivos , Fatores de Risco
16.
Eur Respir J ; 50(4)2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-29074542

RESUMO

Novel anti-inflammatory approaches targeting chronically activated kinase pathways in chronic obstructive pulmonary disease (COPD) are needed. We evaluated RV568, a p38 mitogen-activated protein kinase-α and -γ and SRC family kinase inhibitor, in cellular and in vivo models relevant to COPD and examined its safety and efficacy in COPD patients.The anti-inflammatory activities of RV568 were tested in primary cultured monocytes, macrophages and bronchial epithelial cells and in vivo in lipopolysaccharide and cigarette smoke-exposed murine models. RV568 was evaluated in a 14-day trial in COPD patients.RV568 showed potent anti-inflammatory effects in monocytes and macrophages, which were often greater than those of corticosteroids or the p38 inhibitor Birb796. RV568 combined with corticosteroid had anti-inflammatory effects suggestive of a synergistic interaction in poly I:C-stimulated BEAS-2B cells and in the cigarette smoke model. In COPD patients, inhaled RV568 (50 µg and 100 µg) improved pre-bronchodilator forced expiratory volume in 1 s (69 mL and 48 mL respectively) and significantly reduced sputum malondialdehyde (p<0.05) compared to placebo, although there were no changes in sputum cell counts. Adverse events during RV568 and placebo treatment were similar.RV568 shows potent anti-inflammatory effects on cell and animal models relevant to COPD. RV568 was well-tolerated and demonstrated a modest clinical benefit in a 14-day COPD clinical trial.


Assuntos
Anti-Inflamatórios/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidores , Corticosteroides/uso terapêutico , Adulto , Idoso , Animais , Fumar Cigarros/efeitos adversos , Modelos Animais de Doenças , Método Duplo-Cego , Células Epiteliais/metabolismo , Feminino , Volume Expiratório Forçado/efeitos dos fármacos , Humanos , Macrófagos/metabolismo , Masculino , Camundongos , Pessoa de Meia-Idade , Monócitos/metabolismo , Naftalenos/uso terapêutico , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Pirazóis/uso terapêutico , Escarro/citologia , Reino Unido
17.
PLoS Genet ; 13(9): e1007013, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28922417

RESUMO

The DNA repair enzyme polynucleotide kinase/phosphatase (PNKP) protects genome integrity by restoring ligatable 5'-phosphate and 3'-hydroxyl termini at single-strand breaks (SSBs). In humans, PNKP mutations underlie the neurological disease known as MCSZ, but these individuals are not predisposed for cancer, implying effective alternative repair pathways in dividing cells. Homology-directed repair (HDR) of collapsed replication forks was proposed to repair SSBs in PNKP-deficient cells, but the critical HDR protein Rad51 is not required in PNKP-null (pnk1Δ) cells of Schizosaccharomyces pombe. Here, we report that pnk1Δ cells have enhanced requirements for Rad3 (ATR/Mec1) and Chk1 checkpoint kinases, and the multi-BRCT domain protein Brc1 that binds phospho-histone H2A (γH2A) at damaged replication forks. The viability of pnk1Δ cells depends on Mre11 and Ctp1 (CtIP/Sae2) double-strand break (DSB) resection proteins, Rad52 DNA strand annealing protein, Mus81-Eme1 Holliday junction resolvase, and Rqh1 (BLM/WRN/Sgs1) DNA helicase. Coupled with increased sister chromatid recombination and Rad52 repair foci in pnk1Δ cells, these findings indicate that lingering SSBs in pnk1Δ cells trigger Rad51-independent homology-directed repair of collapsed replication forks. From these data, we propose models for HDR-mediated tolerance of persistent SSBs with 3' phosphate in pnk1Δ cells.


Assuntos
Enzimas Reparadoras do DNA/genética , Reparo do DNA/genética , Polinucleotídeo 5'-Hidroxiquinase/genética , Rad51 Recombinase/genética , Quinase 1 do Ponto de Checagem/genética , Quinase do Ponto de Checagem 2/genética , Quebras de DNA de Cadeia Dupla , Quebras de DNA de Cadeia Simples , Dano ao DNA/genética , Replicação do DNA/genética , Proteínas de Ligação a DNA/genética , Endonucleases/genética , Exodesoxirribonucleases/genética , Resolvases de Junção Holliday/genética , Humanos , Mutação , Reparo de DNA por Recombinação/genética , Schizosaccharomyces/genética , Proteínas de Schizosaccharomyces pombe/genética
18.
Int J Comput Assist Radiol Surg ; 12(6): 1069-1077, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28361324

RESUMO

PURPOSE: Accurate image guidance requires a rigid connection between tracked fiducial markers and the patient, which cannot be guaranteed by current non-invasive attachment techniques. We propose a new granular jamming approach to firmly, yet non-invasively, connect fiducials to the patient. METHODS: Our granular jamming cap surrounds the head and conforms to the contours of the patient's skull. When a vacuum is drawn, the device solidifies in a manner conceptually like a vacuum-packed bag of ground coffee, providing a rigid structure that can firmly hold fiducial markers to the patient's skull. By using the new Polaris Krios optical tracker, we can also use more fiducials in advantageous configurations to reduce registration error. RESULTS: We tested our new approach against a clinically used headband-based fiducial fixation device under perturbations that could reasonably be expected to occur in a real-world operating room. In bump testing, we found that the granular jamming cap reduced average TRE at the skull base from 2.29 to 0.56 mm and maximum TRE at the same point from 7.65 to 1.30 mm. Clinically significant TRE reductions were also observed in head repositioning and static force testing experiments. CONCLUSION: The granular jamming cap concept increases the robustness and accuracy of image-guided sinus and skull base surgery by more firmly attaching fiducial markers to the patient's skull.


Assuntos
Cabeça/cirurgia , Procedimentos Neurocirúrgicos/métodos , Posicionamento do Paciente , Cirurgia Assistida por Computador/métodos , Marcadores Fiduciais , Humanos , Processamento de Imagem Assistida por Computador/métodos
19.
Int Forum Allergy Rhinol ; 6(11): 1126-1130, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27628270

RESUMO

BACKGROUND: Endoscopic repair of anterior skull-base defects has become the gold standard for management of cerebrospinal fluid (CSF) rhinorrhea. Both improved techniques and adjuvant therapies have led to accepted success rates of greater than 90%. As management has evolved, shorter hospitalizations have been required and the goal of this study is to analyze the outcomes of patients repaired on an outpatient basis vs those managed as inpatients postoperatively. METHODS: Patients undergoing endoscopic repair of CSF rhinorrhea between 2004 and 2014 were identified by review of medical records. Demographic and clinical data were collected and compared between patients having surgery with and without postoperative admission. Patients managed with lumbar drains were not included. Statistical analyses were preformed to determine if any differences in patient demographics and outcomes existed. RESULTS: A total of 86 patients were identified; 39 of 86 patients (45.3%) underwent outpatient surgery; 47 patients were admitted postoperatively with a mean hospital stay of 1.66 days with a median and mode of 1 day. No statistically significant differences were found between leak location, etiology, rates of recurrence, or complications. The outpatient group was found to have a greater proportion of small defects <1 cm2 (p = 0.003). Repair technique was also significantly different between groups (p = 0.001). CONCLUSION: Endoscopic management of CSF rhinorrhea is a safe method of treatment with reliable success rates. Our retrospective analysis revealed comparable outcomes in patients treated with and without postoperative hospital admission, and supports the idea that outpatient management may be reasonable in certain patients, especially those with defects <1 cm2 .


Assuntos
Rinorreia de Líquido Cefalorraquidiano/cirurgia , Endoscopia , Adulto , Endoscopia/efeitos adversos , Feminino , Humanos , Complicações Intraoperatórias , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Recidiva , Base do Crânio/anormalidades , Base do Crânio/cirurgia , Resultado do Tratamento
20.
G3 (Bethesda) ; 6(10): 3317-3333, 2016 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-27558664

RESUMO

Heavy metals and metalloids such as cadmium [Cd(II)] and arsenic [As(III)] are widespread environmental toxicants responsible for multiple adverse health effects in humans. However, the molecular mechanisms underlying metal-induced cytotoxicity and carcinogenesis, as well as the detoxification and tolerance pathways, are incompletely understood. Here, we use global fitness profiling by barcode sequencing to quantitatively survey the Schizosaccharomyces pombe haploid deletome for genes that confer tolerance of cadmium or arsenic. We identified 106 genes required for cadmium resistance and 110 genes required for arsenic resistance, with a highly significant overlap of 36 genes. A subset of these 36 genes account for almost all proteins required for incorporating sulfur into the cysteine-rich glutathione and phytochelatin peptides that chelate cadmium and arsenic. A requirement for Mms19 is explained by its role in directing iron-sulfur cluster assembly into sulfite reductase as opposed to promoting DNA repair, as DNA damage response genes were not enriched among those required for cadmium or arsenic tolerance. Ubiquinone, siroheme, and pyridoxal 5'-phosphate biosynthesis were also identified as critical for Cd/As tolerance. Arsenic-specific pathways included prefoldin-mediated assembly of unfolded proteins and protein targeting to the peroxisome, whereas cadmium-specific pathways included plasma membrane and vacuolar transporters, as well as Spt-Ada-Gcn5-acetyltransferase (SAGA) transcriptional coactivator that controls expression of key genes required for cadmium tolerance. Notable differences are apparent with corresponding screens in the budding yeast Saccharomyces cerevisiae, underscoring the utility of analyzing toxic metal defense mechanisms in both organisms.


Assuntos
Adaptação Biológica , Arsênio/farmacologia , Cádmio/farmacologia , Aptidão Genética , Schizosaccharomyces/efeitos dos fármacos , Schizosaccharomyces/genética , Arsênio/metabolismo , Transporte Biológico , Cádmio/metabolismo , Análise por Conglomerados , Biologia Computacional/métodos , Cisteína/biossíntese , Dano ao DNA , Perfilação da Expressão Gênica , Regulação Fúngica da Expressão Gênica , Ontologia Genética , Intoxicação por Metais Pesados , Proteínas de Membrana Transportadoras/metabolismo , Redes e Vias Metabólicas , Testes de Sensibilidade Microbiana , Mitocôndrias/metabolismo , Mutação , Oxirredução , Estresse Oxidativo , Peroxissomos/metabolismo , Fenótipo , Fitoquelatinas/biossíntese , Intoxicação , Schizosaccharomyces/metabolismo , Proteínas de Schizosaccharomyces pombe/metabolismo , Fatores de Transcrição/metabolismo , Vitamina B 6/metabolismo
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