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1.
Neuro Oncol ; 2024 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-38581292

RESUMO

BACKGROUND: Survival is variable in patients with glioblastoma IDH wild-type (GBM), even after comparable surgical resection of radiographically-detectable disease, highlighting the limitations of radiographic assessment of infiltrative tumor anatomy. The majority of post-surgical progressive events are failures within 2cm of the resection margin, motivating supramaximal resection strategies to improve local control. However, which patients benefit from such radical resections remains unknown. METHODS: We developed a predictive model to identify which IDH wild-type GBM are amenable to radiographic gross total resection (GTR). We then investigated whether GBM survival heterogeneity following GTR is correlated with microscopic tumor burden a by analyzing tumor cell content at the surgical margin with a rapid qPCR-based method for detection of TERT promoter mutation. RESULTS: Our predictive model for achievable GTR, developed on retrospective radiographic and molecular data of GBM patients undergoing resection, had an AUC of 0.83, sensitivity of 62%, and specificity of 90%. Prospective analysis of this model in 44 patients found 89% of patients were correctly predicted to achieve a RV<4.9cc. Of the 44 prospective patients undergoing rapid qPCR TERT promoter mutation analysis at the surgical margin, 7 had undetectable TERT mutation, of which 5 also had a gross total resection (RV<1cc). In these 5 patients at 30 months follow up, 75% showed no progression, compared to 0% in the group with TERT mutations detected at the surgical margin (p=0.02). CONCLUSIONS: These findings identify a subset of patients with GBM that may derive local control benefit from radical resection to undetectable molecular margins.

2.
Cancers (Basel) ; 16(8)2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38672676

RESUMO

High-grade gliomas (HGGs) have a poor prognosis and are difficult to treat. This review examines the evolving landscape of endovascular therapies for HGGs. Recent advances in endovascular catheter technology and delivery methods allow for super-selective intra-arterial cerebral infusion (SSIACI) with increasing precision. This treatment modality may offer the ability to deliver anti-tumoral therapies directly to tumor regions while minimizing systemic toxicity. However, challenges persist, including blood-brain barrier (BBB) penetration, hemodynamic complexities, and drug-tumor residence time. Innovative adjunct techniques, such as focused ultrasound (FUS) and hyperosmotic disruption, may facilitate BBB disruption and enhance drug penetration. However, hemodynamic factors that limit drug residence time remain a limitation. Expanding therapeutic options beyond chemotherapy, including radiotherapy and immunobiologics, may motivate future investigations. While preclinical and clinical studies demonstrate moderate efficacy, larger randomized trials are needed to validate the clinical benefits. Additionally, future directions may involve endovascular sampling for peri-tumoral surveillance; changes in drug formulations to prolong residence time; and the exploration of non-pharmaceutical therapies, like radioembolization and photodynamic therapy. Endovascular strategies hold immense potential in reshaping HGG treatment paradigms, offering targeted and minimally invasive approaches. However, overcoming technical challenges and validating clinical efficacy remain paramount for translating these advancements into clinical care.

3.
Vaccine ; 41(35): 5113-5125, 2023 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-37321893

RESUMO

Development of a vaccine drug product requires formulation optimization to ensure that the vaccine's effectiveness is preserved upon storage throughout the shelf-life of the product. Although aluminum adjuvants have been widely used in vaccine formulations to safely and effectively potentiate an immune response, careful attention must be directed towards ensuring that the type of aluminum adjuvant does not impact the stability of the antigenic composition. PCV15 is a polysaccharide-protein conjugate vaccine comprising the pneumococcal polysaccharide (PnPs) serotypes (1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, 22F, 23F and 33F), each individually conjugated to the protein carrier CRM197. PCV15 was formulated with either amorphous aluminum hydroxyphosphate sulfate adjuvant (AAHS) or aluminum phosphate adjuvant (AP) and examined for both stability and immunogenicity. Using a collection of methods to evaluate vaccine stability, it was discovered that certain PCV15 serotypes (e.g., 6A, 19A, 19F) formulated with AAHS resulted in a reduction of immunogenicity in vivo and a reduction in recoverable dose as tested by an in vitro potency assay. The same polysaccharide-protein conjugates formulated with AP were stable regarding all measures tested. Moreover, the reduction in potency of certain serotypes correlated with chemical degradation of the polysaccharide antigen caused by the aluminum adjuvant as measured by reducing polyacrylamide gel electrophoresis (SDS-PAGE), High-Pressure Size Exclusion Chromatography coupled with UV detection (HPSEC-UV) and ELISA immunoassay. This study suggests a formulation, which includes AAHS, may negatively impact the stability of a pneumococcal polysaccharide-protein conjugate vaccine that contains phosphodiester groups. This decrease in stability would likely result in a decrease in the "active" concentration of antigen dose, and herein, it is shown that such instability directly compromised vaccine immunogenicity in an animal model. The results presented in this study help to explain critical degradation mechanisms of pneumococcal polysaccharide-protein conjugate vaccines.


Assuntos
Alumínio , Infecções Pneumocócicas , Animais , Vacinas Conjugadas , Vacinas Pneumocócicas , Sorogrupo , Adjuvantes Imunológicos , Infecções Pneumocócicas/prevenção & controle , Anticorpos Antibacterianos
4.
Front Neurol ; 14: 1150670, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37114230

RESUMO

Introduction: Intraoperative neuromonitoring (IONM) is crucial to preserve eloquent neurological functions during brain tumor resections. We observed a rare interlimb cortical motor facilitation phenomenon in a patient with recurrent high-grade glioma undergoing craniotomy for tumor resection; the patient's upper arm motor evoked potentials (MEPs) increased in amplitude significantly (up to 44.52 times larger, p < 0.001) following stimulation of the ipsilateral posterior tibial nerve at 2.79 Hz. With the facilitation effect, the cortical MEP stimulation threshold was reduced by 6 mA to maintain appropriate continuous motor monitoring. It likely has the benefit of reducing the occurrence of stimulation-induced seizures and other adverse events associated with excessive stimulation. Methods: We conducted a retrospective data review including 120 patients who underwent brain tumor resection with IONM at our center from 2018 to 2022. A broad range of variables collected pre-and intraoperatively were reviewed. The review aimed to determine: (1) whether we overlooked this facilitation phenomenon in the past, (2) whether this unique finding is related to any specific demographic information, clinical presentation, stimulation parameter (s) or anesthesia management, and (3) whether it is necessary to develop new techniques (such as facilitation methods) to reduce cortical stimulation intensity during intraoperative functional mapping. Results: There is no evidence suggesting that clinical presentation, stimulation configuration, or intraoperative anesthesia management of the patient with the facilitation effect were significantly different from our general patient cohort. Even though we did not identify the same facilitation effect in any of these patients, we were able to determine that stimulation thresholds for motor mapping are significantly associated with the location of stimulation (p = 0.003) and the burst suppression ratio (BSR) (p < 0.001). Stimulation-induced seizures, although infrequent (4.05%), could occur unexpectedly even when the BSR was 70%. Discussion: We postulated that functional reorganization and neuronal hyperexcitability induced by glioma progression and repeated surgeries were probable underlying mechanisms of the interlimb facilitation phenomenon. Our retrospective review also provided a practical guide to cortical motor mapping in brain tumor patients under general anesthesia. We also underscored the need for developing new techniques to reduce the stimulation intensity and, hence, seizure occurrence.

5.
Pediatr Infect Dis J ; 39(1): 70-77, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31725555

RESUMO

BACKGROUND: Evaluation of a pneumococcal conjugate vaccine (PCV) in an animal model provides an initial assessment of the performance of the vaccine prior to evaluation in humans. Cost, availability, study duration, cross-reactivity and applicability to humans are several factors which contribute to animal model selection. PCV15 is an investigational 15-valent PCV which includes capsular polysaccharides from pneumococcal serotypes (ST) 1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, 22F, 23F and 33F all individually conjugated to cross-reactive material 197 (CRM197). METHODS: Immunogenicity of PCV15 was evaluated in infant rhesus macaques (IRM), adult New Zealand white rabbits (NZWR) and CD1 mice using multiplexed pneumococcal electrochemiluminescent (Pn ECL) assay to measure serotype-specific IgG antibodies, multiplexed opsonophagocytosis assay (MOPA) to measure serotype-specific functional antibody responses and bacterial challenge in mice to evaluate protection against a lethal dose of S. pneumoniae. RESULTS: PCV15 was immunogenic and induced both IgG and functional antibodies to all 15 vaccine serotypes in all animal species evaluated. PCV15 also protected mice from S. pneumoniae serotype 14 intraperitoneal challenge. Opsonophagocytosis assay (OPA) titers measured from sera of human infants vaccinated with PCV15 in a Phase 2 clinical trial showed a good correlation with that observed in IRM (rs=0.69, P=0.006), a medium correlation with that of rabbits (rs=0.49, P=0.06), and no correlation with that of mice (rs=0.04, P=0.89). In contrast, there was no correlation in serum IgG levels between human infants and animal models. CONCLUSIONS: These results demonstrate that PCV15 is immunogenic across multiple animal species, with IRM and human infants showing the best correlation for OPA responses.


Assuntos
Imunogenicidade da Vacina , Infecções Pneumocócicas/prevenção & controle , Vacinas Pneumocócicas/imunologia , Streptococcus pneumoniae/imunologia , Vacinas Conjugadas/imunologia , Animais , Anticorpos Antibacterianos/sangue , Anticorpos Antibacterianos/imunologia , Linhagem Celular Tumoral , Modelos Animais de Doenças , Vacina Pneumocócica Conjugada Heptavalente/imunologia , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Camundongos
6.
Brain Sci ; 9(11)2019 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31683631

RESUMO

Glial cells comprise the majority of cells in the central nervous system and exhibit diverse functions including the development of persistent neuropathic pain. While earlier theories have proposed that the applied electric field specifically affects neurons, it has been demonstrated that electrical stimulation (ES) of neural tissue modulates gene expression of the glial cells. This study examines the effect of ES on the expression of eight genes related to oxidative stress and neuroprotection in cultured rodent glioma cells. Concentric bipolar electrodes under seven different ES types were used to stimulate cells for 30 min in the presence and absence of extracellular glutamate. ES consisted of rectangular pulses at 50 Hz in varying proportions of anodic and cathodic phases. Real-time reverse-transcribed quantitative polymerase chain reaction was used to determine gene expression using the ∆∆Cq method. The results demonstrate that glutamate has a significant effect on gene expression in both stimulated and non-stimulated groups. Furthermore, stimulation parameters have differential effects on gene expression, both in the presence and absence of glutamate. ES has an effect on glial cell gene expression that is dependent on waveform composition. Optimization of ES therapy for chronic pain applications can be enhanced by this understanding.

7.
Tob Prev Cessat ; 5: 13, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-32411877

RESUMO

INTRODUCTION: This study aims to determine if smokers at post-secondary campuses are more likely to adhere to smoke-free zones (areas where smoking is not permitted) or smoking zones (areas where smoking is permitted) based on preference and effectiveness. METHODS: A self-reported survey was developed and administered at two postsecondary institutions; Western University (smoke-free zones) and Fanshawe College (smoking zones). Smokers were asked how often they use these zones, which zone is preferred and which zone they think is more effective. A chi-squared analysis was performed to determine if there were differences in the frequency of responses. RESULTS: A total of 239 surveys were collected, 119 from Western and 120 from Fanshawe. Of these, 87% of respondents at Fanshawe were aware of where they could smoke on campus, and 67% reported that they mostly or always used these spaces. At Western, significantly fewer respondents knew where to smoke (57%), and only 30% reported mostly or always using appropriate zones (p<0.05). More participants at Fanshawe indicated that they had been told by someone in authority where they could smoke (36%) compared to Western (19%, p<0.05). At Fanshawe, 63% of respondents stated that smoking zones mostly or always effectively indicated where it was appropriate to smoke on campus compared to only 18% at Western (p<0.05). Both groups indicated they preferred the zone they currently had. Finally, more participants from Fanshawe intend to quit smoking within 6 months (61% from Fanshawe vs 49% from Western, p<0.05). CONCLUSIONS: Smoking zones on post-secondary campuses may be more effective and adhered to by smokers than smoke-free zones.

8.
PDA J Pharm Sci Technol ; 72(2): 149-162, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29343619

RESUMO

Aluminum-containing adjuvants have been widely used in vaccine formulations to safely and effectively potentiate the immune response. The examination of the extent of antigen adsorption to aluminum adjuvant is always evaluated during the development of aluminum adjuvant containing vaccines. A rapid, automated, high-throughput assay was developed to measure antigen adsorption in a 96-well plate format using a TECAN Freedom EVO® (TECAN). The antigen adsorption levels at a constant adjuvant concentration for each sample were accurately measured at 12 antigen/adjuvant (w/w) formulation ratios. These measurements were done at aluminum adjuvant concentrations similar to normal vaccine formulations, unlike previous non-automated and automated adjuvant adsorption studies. Two high-sensitivity analytical methods were used to detect the non-absorbed antigens. The antigen-to-adjuvant adsorption curves were fit to a simple Langmuir adsorption model for quantitatively analyzing the antigen to the adjuvant adsorption level and strength. The interaction of two model antigens, bovine serum albumin and lysozyme, with three types of aluminum adjuvant, were quantitatively analyzed in this report. Automated, high-throughput methodologies combined with sensitive analytical methods are useful for accelerating practical vaccine formulation development.LAY ABSTRACT: Vaccines are probably the most effective public health method to prevent epidemics of many infectious diseases. Many of the most effective vaccines contain aluminum adjuvant. This report describes novel technology that can be used to better optimize the efficacy and stability of aluminum adjuvant-containing vaccines.


Assuntos
Adjuvantes Imunológicos/química , Compostos de Alumínio/química , Antígenos/química , Ensaios de Triagem em Larga Escala , Tecnologia Farmacêutica/métodos , Vacinas/química , Adjuvantes Imunológicos/metabolismo , Adsorção , Compostos de Alumínio/metabolismo , Hidróxido de Alumínio/química , Hidróxido de Alumínio/metabolismo , Antígenos/metabolismo , Automação , Composição de Medicamentos , Muramidase/química , Muramidase/metabolismo , Fosfatos/química , Fosfatos/metabolismo , Ligação Proteica , Soroalbumina Bovina/química , Soroalbumina Bovina/metabolismo , Propriedades de Superfície , Vacinas/metabolismo
9.
J Pharmacol Exp Ther ; 344(1): 308-16, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23129783

RESUMO

Sulfur mustard (SM) is a vesicant chemical warfare and terrorism agent. Besides skin and eye injury, respiratory damage has been mainly responsible for morbidity and mortality after SM exposure. Previously, it was shown that suppressing the death receptor (DR) response by the dominant-negative Fas-associated death domain protein prior to SM exposure blocked apoptosis and microvesication in skin. Here, we studied whether antagonizing the Fas receptor (FasR) pathway by small-interfering RNA (siRNA) applied after SM exposure would prevent apoptosis and, thus, airway injury. Normal human bronchial/tracheal epithelial (NHBE) cells were used as an in vitro model with FasR siRNA, FasR agonistic antibody CH11, and FasR antagonistic antibody ZB4 as investigative tools. In NHBE cells, both SM (300 µM) and CH11 (100 ng/ml) induced caspase-3 activation, which was inhibited by FasR siRNA and ZB4, indicating that SM-induced apoptosis was via the Fas response. FasR siRNA inhibited SM-induced caspase-3 activation when added to NHBE cultures up to 8 hours after SM. Results using annexin V/propidium iodide-stained cells showed that both apoptosis and necrosis were involved in cell death due to SM; FasR siRNA decreased both apoptotic and necrotic cell populations. Bronchoalveolar lavage fluid (BALF) of rats exposed to SM (1 mg/kg, 50 minutes) revealed a significant (P < 0.05) increase in soluble Fas ligand and active caspase-3 in BALF cells. These findings suggest an intervention of Fas-mediated apoptosis as a postexposure therapeutic strategy with a therapeutic window for SM inhalation injury and possibly other respiratory diseases involving the Fas response.


Assuntos
Apoptose/efeitos dos fármacos , Substâncias para a Guerra Química/toxicidade , Células Epiteliais/efeitos dos fármacos , Gás de Mostarda/toxicidade , RNA Interferente Pequeno/farmacologia , Receptor fas/antagonistas & inibidores , Receptor fas/genética , Animais , Western Blotting , Líquido da Lavagem Broncoalveolar/química , Queimaduras por Inalação/tratamento farmacológico , Caspase 3/metabolismo , Linhagem Celular , Células Cultivadas , Ativação Enzimática/fisiologia , Ensaio de Imunoadsorção Enzimática , Proteína Ligante Fas/análise , Proteína Ligante Fas/metabolismo , Citometria de Fluxo , Humanos , Masculino , Ratos , Ratos Sprague-Dawley , Sistema Respiratório/citologia , Sistema Respiratório/efeitos dos fármacos , Transfecção
10.
Cutan Ocul Toxicol ; 27(1): 41-53, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18330833

RESUMO

Results of our previous studies on the chemical warfare agent sulfur mustard (2,2'-dichlorodiethyl sulfide) suggested that mustard-induced inhibition of glycolysis is not solely a function of NAD+ depletion. To define the role of NAD+ in mustard-induced metabolic injury, we examined the effects of mustard+/-niacinamide on energy metabolism in cultured human keratinocytes. Sulfur mustard caused concentration-dependent decreases in viable cell number and ATP content at 24 hours, but not earlier, and time- and concentration-dependent glycolytic inhibition and NAD+ depletion as early as 4 hours. Niacinamide partially protected NAD+ levels at all time points, but did not prevent adverse effects on glycolysis, intracellular ATP, or viable cell number. These results support our earlier conclusions and suggest that sulfur mustard may inhibit glycolysis directly.


Assuntos
Substâncias para a Guerra Química/toxicidade , Metabolismo Energético/efeitos dos fármacos , Queratinócitos/efeitos dos fármacos , Gás de Mostarda/toxicidade , NAD/metabolismo , Niacinamida/farmacologia , Complexo Vitamínico B/farmacologia , Trifosfato de Adenosina/metabolismo , Contagem de Células , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Glucose/metabolismo , Glicólise/efeitos dos fármacos , Humanos , Queratinócitos/metabolismo , NAD/deficiência , Fatores de Tempo
11.
Cutan Ocul Toxicol ; 25(3): 155-63, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16980241

RESUMO

Sulfur mustard (SM) is a powerful cytotoxic agent as well as a potent vesicant, mutagen, and carcinogen. This compound reacts with glutathione (GSH) and forms GSH-SM conjugates that appear to be excreted through the mercapturic acid pathway in mammals. The question of whether glutathione-S-transferases (GST) are involved in enzymatic formation of these conjugates remains unresolved. In previous studies, ethacrynic acid (EAA), a putative inhibitor of this transferase, and oltipraz, a known inducer,were ineffective in modulating this enzyme in cultured normal human epidermal keratinocytes (NHEK) so this hypothesis could not be tested. Higher levels of intracellular GSH appeared to be solely responsible for resistance of EAA-pretreated cells to SM. A better inducer of GST was needed to test whether this enzyme could be used to modify cytotoxicity following SM exposure. D,L-sulforaphane (DLS), a compound from broccoli extract known to be a potent inducer of this enzyme, was tested for GST induction in cultured NHEK. The enzyme levels increased optimally (40%) in these cells within 4 hours using 0.5 microg DLS/mL over a 48 hour incubation period. When the drug was removed by washing, and pretreated cells were challenged with 0-200 microM SM, there was a 10%-15% increase in survival at 24 hours compared with non-pretreated SM controls. This protective effect due to increased levels of GST was abolished at 300 microM sulfur mustard, where there was no difference in survival between pretreated and non-pretreated controls. Glutathione levels were also assessed and showed no increase at 4 hours in cultured NHEK with DLS pretreatment and appear not to be responsible for this protection against SM.


Assuntos
Substâncias para a Guerra Química/toxicidade , Epiderme/efeitos dos fármacos , Glutationa Transferase/metabolismo , Queratinócitos/efeitos dos fármacos , Gás de Mostarda/toxicidade , Tiocianatos/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Indução Enzimática , Epiderme/enzimologia , Glutationa/metabolismo , Glutationa Transferase/biossíntese , Humanos , Isotiocianatos , Queratinócitos/enzimologia , Sulfóxidos , Tiocianatos/toxicidade , Fatores de Tempo
12.
Mil Med ; 171(5): 448-53, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16761898

RESUMO

Although best known as a blistering agent, sulfur mustard (HD) can also induce neutropenia in exposed individuals, increasing their susceptibility to infection. Granulocyte colony-stimulating factor (G-CSF) and pegylated G-CSF (peg-G-CSF) have been approved by the U.S. Food and Drug Administration as hematopoietic growth factors to treat chemotherapy-induced neutropenia. The goal of this study was to determine the effectiveness of G-CSF and peg-G-CSF in ameliorating HD-induced neutropenia. African green monkeys (Chlorocebus aethiops) were challenged with HD and, at 1, 3, 5, or 7 days after exposure, G-CSF therapy (10 microg/kg per day for 21 days) was initiated. Peg-G-CSF (300 microg/kg, single treatment) was similarly tested, with treatment given at 3 days after exposure. Untreated HD-exposed animals recovered from neutropenia 28 days after exposure, whereas G-CSF- or peg-G-CSF-treated animals recovered 8 to 19 days after exposure (p < 0.05). These results indicate that G-CSF or peg-G-CSF may provide Food and Drug Administration-approved treatments that will reduce the duration of HD-induced neutropenia.


Assuntos
Fator Estimulador de Colônias de Granulócitos/uso terapêutico , Gás de Mostarda/efeitos adversos , Neutropenia/induzido quimicamente , Animais , Fator Estimulador de Colônias de Granulócitos/administração & dosagem , Haplorrinos , Masculino , Estados Unidos
13.
Biochemistry ; 44(40): 13282-90, 2005 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-16201754

RESUMO

The Rho family GTPase Cdc42 functions as a molecular switch and controls many fundamental cellular processes such as cytoskeletal regulation, cell polarity, and vesicular trafficking. Guanine nucleotide exchange factors of the Dbl family activate Cdc42 and other Rho GTPases by catalyzing the removal of bound GDP, allowing for GTP loading, and subsequent effector recognition ultimately leading to downstream signaling events. Analysis of existing structural data reveals that the Dbl exchange factor intersectin engages a strictly conserved GTPase residue of Cdc42 (tyrosine 32) in a unique mode with respect to all other visualized exchange factor-Rho GTPase interfaces. To investigate this differential binding architecture, we analyzed the role of tyrosine 32 of Cdc42 in binding, and stimulation by Dbl family exchange factors. Deletion of the hydroxyl side chain of tyrosine 32 substantially increases the affinity of Cdc42 for intersectin, yet severely cripples interaction with Dbs, a normally potent exchange factor of Cdc42. Moreover, Cdc42(Y32F) is exclusively activated by intersectin, while virtually unresponsive to other Cdc42-activating exchange factors in vitro and in vivo. Further, the structural determinants unique to intersectin, which permit selective recognition and concomitant stimulation of Cdc42(Y32F), have been defined. Cdc42 and other individual Rho GTPases receive input stimulatory signals from a multitude of Dbl exchange factors, and therefore, Cdc42(Y32F) could act as a valuable reagent for understanding the specific influence of ITSN on Cdc42-mediated signaling phenomena.


Assuntos
Proteínas Adaptadoras de Transporte Vesicular/química , Mutação , Proteína cdc42 de Ligação ao GTP/genética , Proteínas Adaptadoras de Transporte Vesicular/metabolismo , Sequência de Aminoácidos , Animais , Catálise , Cristalografia por Raios X , Citoesqueleto/metabolismo , DNA Complementar/metabolismo , Proteínas de Fluorescência Verde/metabolismo , Guanina/química , Fatores de Troca do Nucleotídeo Guanina/química , Guanosina Difosfato/química , Guanosina Trifosfato/química , Células HeLa , Humanos , Cinética , Camundongos , Microscopia de Fluorescência , Modelos Moleculares , Dados de Sequência Molecular , Plasmídeos/metabolismo , Mutação Puntual , Ligação Proteica , Conformação Proteica , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Proteínas Proto-Oncogênicas c-vav/química , Fatores de Troca de Nucleotídeo Guanina Rho , Transdução de Sinais , Ressonância de Plasmônio de Superfície , Fatores de Tempo , Tirosina/química , Proteínas rho de Ligação ao GTP/química
14.
J Biol Chem ; 279(30): 31409-18, 2004 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-15143060

RESUMO

The Golgi-localized, gamma-adaptin ear-containing, ARF-binding (GGA) proteins are monomeric clathrin adaptors that mediate the sorting of cargo at the trans-Golgi network and endosomes. The GGAs contain four different domains named Vps27, Hrs, Stam (VHS); GGAs and TOM1 (GAT); hinge; and gamma-adaptin ear (GAE). The VHS domain recognizes transmembrane cargo, whereas the hinge and GAE regions bind clathrin and accessory proteins, respectively. The GAT domain is a polyfunctional module that interacts with various partners including the small GTPase ARF, the endosomal fusion regulator Rabaptin-5, ubiquitin, and the product of the tumor susceptibility gene 101 (TSG101). Previous x-ray crystallographic analyses showed that the GAT region is composed of two subdomains, an N-terminal helix-loop-helix containing the ARF binding site, and a C-terminal triple alpha-helical (trihelical) bundle. In this study, we define the Rabaptin-5 binding site on the GGA1-GAT domain and its relationship to the binding sites for ubiquitin and TSG101. Our observations show that Rabaptin-5, ubiquitin, and TSG101 bind to overlapping but distinct binding sites on the trihelical bundle. The different GAT binding partners engage in both competitive and cooperative interactions that may be important for the function of the GGAs in protein sorting.


Assuntos
Fatores de Ribosilação do ADP/química , Fatores de Ribosilação do ADP/metabolismo , Proteínas Adaptadoras de Transporte Vesicular , Proteínas de Transporte/química , Proteínas de Transporte/metabolismo , Fator 1 de Ribosilação do ADP/química , Fator 1 de Ribosilação do ADP/genética , Fator 1 de Ribosilação do ADP/metabolismo , Fatores de Ribosilação do ADP/genética , Sequência de Aminoácidos , Substituição de Aminoácidos , Sítios de Ligação/genética , Proteínas de Transporte/genética , Humanos , Técnicas In Vitro , Modelos Moleculares , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Estrutura Terciária de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Homologia de Sequência de Aminoácidos , Técnicas do Sistema de Duplo-Híbrido , Proteínas de Transporte Vesicular/química , Proteínas de Transporte Vesicular/genética , Proteínas de Transporte Vesicular/metabolismo , Proteínas rab de Ligação ao GTP/química , Proteínas rab de Ligação ao GTP/genética , Proteínas rab de Ligação ao GTP/metabolismo
15.
J Biol Chem ; 278(10): 8531-40, 2003 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-12482751

RESUMO

DNA damaging agents up-regulate levels of the Fas receptor or its ligand, resulting in recruitment of Fas-associated death domain (FADD) and autocatalytic activation of caspase-8, consequently activating the executioner caspases-3, -6, and -7. We found that human epidermal keratinocytes exposed to a vesicating dose (300 microm) of sulfur mustard (SM) exhibit a dose-dependent increase in the levels of Fas receptor and Fas ligand. Immunoblot analysis revealed that the upstream caspases-8 and -9 are both activated in a time-dependent fashion, and caspase-8 is cleaved prior to caspase-9. These results are consistent with the activation of both death receptor (caspase-8) and mitochondrial (caspase-9) pathways by SM. Pretreatment of keratinocytes with a peptide inhibitor of caspase-3 (Ac-DEVD-CHO) suppressed SM-induced downstream markers of apoptosis. To further analyze the importance of the death receptor pathway in SM toxicity, we utilized Fas- or tumor necrosis factor receptor-neutralizing antibodies or constructs expressing a dominant-negative FADD (FADD-DN) to inhibit the recruitment of FADD to the death receptor complex and block the Fas/tumor necrosis factor receptor pathway following SM exposure. Keratinocytes pretreated with Fas-blocking antibody or stably expressing FADD-DN and exhibiting reduced levels of FADD signaling demonstrated markedly decreased caspase-3 activity when treated with SM. In addition, the processing of procaspases-3, -7, and -8 into their active forms was observed in SM-treated control keratinocytes, but not in FADD-DN cells. Blocking the death receptor complex by expression of FADD-DN additionally inhibited SM-induced internucleosomal DNA cleavage and caspase-6-mediated nuclear lamin cleavage. Significantly, we further found that altering the death receptor pathway by expressing FADD-DN in human skin grafted onto nude mice reduces vesication and tissue injury in response to SM. These results indicate that the death receptor pathway plays a pivotal role in SM-induced apoptosis and is therefore a target for therapeutic intervention to reduce SM injury.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Apoptose/efeitos dos fármacos , Proteínas de Transporte/fisiologia , Queratinócitos/citologia , Gás de Mostarda/farmacologia , Apoptose/fisiologia , Proteínas de Transporte/metabolismo , Caspases/metabolismo , Células Cultivadas , Inibidores de Cisteína Proteinase/farmacologia , Proteína de Domínio de Morte Associada a Fas , Humanos , Hidrólise , Oligopeptídeos/farmacologia , Poli(ADP-Ribose) Polimerases/metabolismo
16.
Toxicol Mech Methods ; 13(4): 263-8, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-20021151

RESUMO

Sulfur mustard (SM) is a potent vesicating agent that has pronounced cytotoxic effects as well as mutagenic, carcinogenic, and radiomimetic properties. Isolated human peripheral blood lymphocytes (PBLs) and human epidermal keratinocytes (HEKs) have been used as in vitro models for determining SM-induced cytotoxicity. A recently developed colorimetric assay (the CellTiter 96 AQ ueous Non-radioactive Cell Proliferation Assay) was assessed using both of the in vitro models described above. Using 24- or 96-well microplates, reproducible (+/- 10%) SM dose/response curves for both types of human cells were obtained using a spectrophotometric microplate reader set at 490 nm. After a 4-h incubation time, as many as 96 sample wells could be measured within 45 s using this commonly available equipment. Multiple plates of samples can be run immediately. This technique may facilitate cytotoxicity investigations of new candidate compounds for both prophylaxis of and therapy for SM intoxication.

17.
Mo Med ; 99(9): 502-4, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12462943

RESUMO

Chronic pelvic pain in females is a common symptom encountered by family practitioners, gynecologists, gastroenterologists, and general surgeons. In this study, we retrospectively reviewed the charts of 22 female patients who had chronic pelvic pain or acute exacerbation of chronic pelvic pain. None had signs of appendicitis. All were treated with a diagnostic laparoscopy with appendectomy. Of the 22 patients, 20 had complete relief of their pain; 17 had an abnormal histopathological diagnosis of their appendices.


Assuntos
Apendicectomia , Laparoscopia , Dor Pélvica/cirurgia , Adolescente , Adulto , Apêndice/patologia , Doença Crônica , Feminino , Seguimentos , Humanos , Dor Pélvica/diagnóstico , Estudos Retrospectivos , Estados Unidos
18.
Br J Pharmacol ; 137(2): 245-52, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12208782

RESUMO

1. The sulphur mustard vesicant 2-chloroethylethyl sulphide (CEES) induced apoptosis in Jurkat cells. 2. Akt (PKB), a pivotal protein kinase which can block apoptosis and promotes cell survival, was identified to be chiefly down-regulated in a dose-dependent manner following CEES treatment. Functional analysis showed that the attendant Akt activity was simultaneously reduced. 3. PDK1, an upstream effector of Akt, was also down-regulated following CEES exposure, but two other upstream effectors of Akt, PI3-K and PDK2, remained unchanged. 4. The phosphorylation of Akt at Ser(473) and Thr(308) was significantly decreased following CEES treatment, reflecting the suppressed kinase activity of both PDK1 and PDK2. 5. Concurrently, the anti-apoptotic genes, Bcl family, were down-regulated, in sharp contrast to the striking up-regulation of some death executioner genes, caspase 3, 6, and 8. 6. Based on these findings, a model of CEES-induced apoptosis was established. These results suggest that CEES attacked the Akt pathway, directly or indirectly, by inhibiting Akt transcription, translation, and post-translation modification. 7. Taken together, upon exposure to CEES, apoptosis was induced in Jurkat cells via the down-regulation of the survival factors that normally prevent the activation of the death executioner genes, the caspases.


Assuntos
Apoptose/efeitos dos fármacos , Irritantes/toxicidade , Gás de Mostarda/toxicidade , Proteínas Quinases Dependentes de 3-Fosfoinositídeo , Caspases/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Genes bcl-2 , Humanos , Células Jurkat , Fosfatidilinositol 3-Quinases/fisiologia , Fosforilação , Proteínas Serina-Treonina Quinases/biossíntese , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-akt
19.
J Pediatr Orthop ; 22(2): 239-43, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-11856939

RESUMO

The authors retrospectively reviewed seven cases of progressive slipped capital femoral epiphysis after screw fixation. All seven patients initially presented with chronic symptoms, and five had an acute exacerbation of symptoms with the appearance of an acute-on-chronic slip. Of the other two, one had obvious motion at the proximal femoral physis and the other had increased symptoms but did not have an obvious acute slip radiographically. All underwent percutaneous screw fixation. In four patients a single screw was placed, and in three patients two screws were placed. No patient became symptom-free after surgery. Slip progression was noted on average 5 months after treatment. Radiographs in all patients revealed an increase in slip severity and loss of screw purchase in the femoral neck while fixation in the proximal femoral epiphysis remained secure. One patient had hypothyroidism and another Cushing disease, both diagnosed after the slipped epiphysis. Slips occurring in children with underlying endocrinopathies, and unstable slips in children with a history of antecedent knee or hip pain (commonly called an acute-on-chronic slip) may be susceptible to screw fixation failure. In such patients, close radiographic follow-up, particularly in the presence of continued symptoms, is required to document slip progression and fixation failure as soon as possible.


Assuntos
Epifise Deslocada/fisiopatologia , Epifise Deslocada/cirurgia , Cabeça do Fêmur , Parafusos Ósseos , Criança , Progressão da Doença , Feminino , Humanos , Masculino , Reoperação
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