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1.
Ann Oncol ; 30(8): 1289-1297, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31147675

RESUMO

BACKGROUND: This hypothesis-generating trial evaluated neoadjuvant ipatasertib-paclitaxel for early triple-negative breast cancer (TNBC). PATIENTS AND METHODS: In this randomized phase II trial, patients with early TNBC (T ≥ 1.5 cm, N0-2) were randomized 1 : 1 to receive weekly paclitaxel 80 mg/m2 with ipatasertib 400 mg or placebo (days 1-21 every 28 days) for 12 weeks before surgery. Co-primary end points were pathologic complete response (pCR) rate (ypT0/TisN0) in the intention-to-treat (ITT) and immunohistochemistry phosphatase and tensin homolog (PTEN)-low populations. Secondary end points included pCR rate in patients with PIK3CA/AKT1/PTEN-altered tumors and pre-surgery response rates by magnetic resonance imaging (MRI). RESULTS: pCR rates with ipatasertib versus placebo were 17% versus 13%, respectively, in the ITT population (N = 151), 16% versus 13% in the immunohistochemistry PTEN-low population (N = 35), and 18% versus 12% in the PIK3CA/AKT1/PTEN-altered subgroup (N = 62). Rates of overall and complete response (CR) by MRI favored ipatasertib in all three populations (CR rate 39% versus 9% in the PIK3CA/AKT1/PTEN-altered subgroup). Ipatasertib was associated with more grade ≥3 adverse events (32% versus 16% with placebo), especially diarrhea (17% versus 1%). Higher cycle 1 day 8 (C1D8) immune score was significantly associated with better response only in placebo-treated patients. All ipatasertib-treated patients with low immune scores and a CR had PIK3CA/AKT1/PTEN-altered tumors. CONCLUSIONS: Adding ipatasertib to 12 weeks of paclitaxel for early TNBC did not clinically or statistically significantly increase pCR rate, although overall response rate by MRI was numerically higher with ipatasertib. The antitumor effect of ipatasertib was most pronounced in biomarker-selected patients. Safety was consistent with prior experience of ipatasertib-paclitaxel. A T-cell-rich environment at C1D8 had a stronger association with improved outcomes in paclitaxel-treated patients than seen for baseline tumor-infiltrating lymphocytes. This dependency may be overcome with the addition of AKT inhibition, especially in patients with PIK3CA/AKT1/PTEN-altered tumors. CLINICALTRIALS.GOV: NCT02301988.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Terapia Neoadjuvante/métodos , Paclitaxel/administração & dosagem , Piperazinas/administração & dosagem , Pirimidinas/administração & dosagem , Neoplasias de Mama Triplo Negativas/terapia , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Biomarcadores Tumorais/antagonistas & inibidores , Biomarcadores Tumorais/genética , Mama/diagnóstico por imagem , Mama/patologia , Mama/cirurgia , Intervalo Livre de Doença , Método Duplo-Cego , Esquema de Medicação , Feminino , Mutação com Ganho de Função , Humanos , Imageamento por Ressonância Magnética , Mastectomia , Pessoa de Meia-Idade , Terapia Neoadjuvante/efeitos adversos , Estadiamento de Neoplasias , Paclitaxel/efeitos adversos , Seleção de Pacientes , Piperazinas/efeitos adversos , Placebos/administração & dosagem , Placebos/efeitos adversos , Pirimidinas/efeitos adversos , Neoplasias de Mama Triplo Negativas/mortalidade , Neoplasias de Mama Triplo Negativas/patologia
2.
Eur J Cancer ; 89: 42-48, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29227816

RESUMO

AIM: To determine the value of mammography and breast ultrasound (US) in predicting outcomes in HER2 positive breast cancer patients (pts) within Neo-ALTTO trial. PATIENTS AND METHODS: Mammography and US were required at baseline, week 6 and surgery. Two independent blinded investigators reviewed the measurements and assigned the corresponding response category. Pts showing complete or partial response according to RECIST (v1.1) were classified as responders. The association between imaging response at week 6 or prior to surgery was evaluated with respect to pathological complete response (pCR) and event-free Survival (EFS). RESULTS: Of the 455 pts enrolled in the trial, 267 (61%) and 340 (77%) had evaluable mammography and US at week 6; 248 (56%) and 309 (70%) pts had evaluable mammography and US prior to surgery. At week 6, 32% and 43% of pts were classified as responders by mammography and US, respectively. pCR rates were twice as high for responders than non-responders (week 6: 46% versus 23% by US, p < 0.0001; 41% versus 24% by mammography, p = 0.007). Positive and negative predictive values of mammography and US prior to surgery were 37% and 35%, and 82% and 70%, respectively. No significant correlation was found between response by mammography and/or US at week 6/surgery and EFS. CONCLUSIONS: Mammography and US were underused in Neo-ALTTO although US had the potential to assess early response whereas mammography to detect residual disease prior to surgery. Our data still emphasise the need for further imaging studies on pts treated with neoadjuvant HER2-targeted therapy.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Mama/diagnóstico por imagem , Quinazolinas/uso terapêutico , Receptor ErbB-2/análise , Trastuzumab/uso terapêutico , Adulto , Idoso , Neoplasias da Mama/química , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/mortalidade , Feminino , Humanos , Lapatinib , Mamografia , Pessoa de Meia-Idade , Terapia Neoadjuvante , Quinazolinas/administração & dosagem , Trastuzumab/administração & dosagem
3.
J Cancer Educ ; 31(4): 660-665, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-26084426

RESUMO

Approximately 60 % of all cancer patients receive radiotherapy as a component of their treatment. Radiation Oncology concepts, specifically, are not formally introduced to students in most traditional school curricula until their clinical rotations or may only be included as an optional elective during the core clinical clerkships. The aim of this study is to determine whether the teaching of Radiation Oncology by radiation oncologists, in the third year, in block diagnostic and therapeutic procedures, is helpful for student training and changes their attitude towards the specialty. We administered a pre-test and post-test examination of the concepts in general radiation oncology, radiation physics, radiobiology, breast cancer and their opinion to the third year medical students. The 10-question, multiple choice tests were administered before starting the lessons and when they finished the course. Of the 130 third year students, 95 (73.07 %) participated in the pre-test and post-test analysis. For the entire cohort, improvement was seen in all questions except one regarding physics. A statistically significant improvement (p < 0.005) was seen in the question regarding the aspects of general radiotherapy, radiobiology, acute and after-effects of radiation and the management of early-stage breast cancer. With an adequate methodology, third year students can learn aspects of Radiation Oncology.


Assuntos
Estágio Clínico , Competência Clínica , Educação de Graduação em Medicina , Neoplasias/radioterapia , Radioterapia (Especialidade)/educação , Currículo , Humanos
4.
Ann Oncol ; 26(7): 1494-500, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25851628

RESUMO

BACKGROUND: Assessment of phosphatase and tensin homolog deleted from chromosome 10 (PTEN) might be an important tool in identifying human epidermal growth factor receptor 2 (HER2)-positive breast cancer patients unlikely to derive benefit from anti-HER2 therapies. However, studies to date have failed to demonstrate its predictive role in any treatment setting. PATIENTS AND METHODS: Prospectively collected baseline core biopsies from 429 early-stage HER2-positive breast cancer patients treated with trastuzumab, lapatinib, or their combination in the Neo-ALTTO study were stained using two anti-PTEN monoclonal antibodies (CST and DAKO). The association of PTEN status and PI3K pathway activation (defined as either PTEN loss and/or PIK3CA mutation) with total pathological complete response (tpCR) at surgery, event-free survival (EFS), and overall survival (OS) was evaluated. RESULTS: PTEN loss was observed in 27% and 29% of patients (all arms, n = 361 and n = 363) for CST and DAKO, respectively. PTEN loss was more frequently observed in hormone receptor (HR)-negative (33% and 36% with CST and DAKO, respectively) compared with HR-positive tumours (20% and 22% with CST and DAKO, respectively). No significant differences in tpCR rates were observed according to PTEN status. PI3K pathway activation was found in 47% and 48% of patients (all arms, n = 302 and n = 301) for CST and DAKO, respectively. Similarly, tpCR rates were not significantly different for those with or without PI3K pathway activation. Neither PTEN status nor PI3K pathway activation were predictive of tpCR, EFS, or OS, independently of treatment arm or HR status. High inter-antibody and inter-observer agreements were found (>90%). Modification of scoring variables significantly affected the correlation between PTEN and HR status but not with tpCR. CONCLUSION: These data show that PTEN status determination is not a useful biomarker to predict resistance to trastuzumab and lapatinib-based therapies. The lack of standardization of PTEN status determination may influence correlations between expression and relevant clinical end points. CLINICAL TRIALS: This trial is registered with ClinicalTrials.gov: NCT00553358.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Cromossomos Humanos Par 10/genética , Deleção de Genes , Terapia Neoadjuvante , PTEN Fosfo-Hidrolase/genética , Receptor ErbB-2/antagonistas & inibidores , Receptor ErbB-2/metabolismo , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/patologia , Feminino , Seguimentos , Humanos , Técnicas Imunoenzimáticas , Lapatinib , Estadiamento de Neoplasias , PTEN Fosfo-Hidrolase/metabolismo , Reação em Cadeia da Polimerase , Prognóstico , Estudos Prospectivos , Quinazolinas/administração & dosagem , Indução de Remissão , Trastuzumab/administração & dosagem
5.
Rev. colomb. anestesiol ; 38(4): 510-525, nov.-ene. 2011. ilus, tab
Artigo em Inglês, Espanhol | LILACS | ID: lil-594555

RESUMO

Introducción. De la coagulopatía aguda en el trauma, resultan múltiples complicaciones como la necesidad de administración de hemoderivados, mayor incidencia de disfunción orgánica, aumento de estancia en unidad de cuidados intensivos y mayor mortalidad. Con el conocimiento actual de la fisiopatología del trauma y la vía celular de la coagulación es ahora posible mejorar el dignóstico y tratamiento de la coagulopatía inicial y conseguir mejores resultados en nuestros centros. Métodos. Este artículo examina la fisiología básica de la coagulación, la etiología, el diagnóstico y el tratamiento de la coagulopatía temprana en trauma. La búsqueda se realizó con términos Mesh y no Mesh con conectores AND: Anesthesia-coagulophaty, postinjury and trauma thromboelastography, transfusion and trauma, shock-Mechanism and trauma review. Resultados. La coagulopatía aguda o temprana en trauma está directamente asociada al estado de shock y se caracteriza por anticoagulación e hiperfibrinolisis sistémica; hay evidencia de la implicación de la proteína C en este proceso. Se ha establecido que seis mecanismos fisiopatológicos multifactoriales pueden perpetuar la coagulopatía en los pacientes traumatizados; éstos son: inflamación, acidosis, hipotermia, shock, trauma tisular y hemodilución. El diagnóstico se realiza con las diferentes pruebas (TP, TPT, plaquetas) ya conocidas desde hace mucho tiempo, pero con limitaciones que reducen su utilidad clínica. Ahora la tromboelastografía nos puede ayudar a guiar la transfusión, con el concepto actual de transfusión temprana de glóbulos rojos, plasma y plaquetas, utilizando la mejor proporción según la evidencia disponible. Conclusiones. Contamos, con algún conocimiento sobre la fisiopatología de la coagulopatía asociada con trauma pero son necesarias más investigaciones, en este campo. El diagnóstico rápido y una intervención directa inmediata son importantes para mejorar el desenlace de nuestros pacientes.


Introduction. Acute coagulopathy in trauma results in multiple complications such as the need for blood products, higher rates of organ dysfunction, longer stay in the ICU and higher mortality. With the current knowledge of the pathophysiology of trauma and of the cellular coagulation pathway it is now possible to improve diagnosis and treatment of the initial coagulopathy and achieve better outcomes in our trauma centers. Methods. This paper looks into the basic physiology of coagulation, and the etiology, diagnosis and treatment of early coagulopathy in trauma. The search was done using Mesh and non-Mesh terms with AND connectors: Anesthesia-coagulopathy, postinjury and trauma thromboelastography, transfusion and trauma, shock-Mechanism and trauma review. Results. Acute or early coagulopathy in trauma is directly associated with a state of shock and is characterized by anticoagulation and systemic hyperfibrinolysis; protein C is known to be implicated in this process. It has also been determined that six multi-factorial pathophysiological mechanisms may perpetuate coagulopathy in trauma patients, namely, inflammation, acidosis, hypothermia, shock, tissue trauma and hemodilution. Diagnosis is made using the different tests (PT, PPT, platelets) that have been in use for a long time; however, these tests have drawbacks that limit their clinical usefulness. Thromboelastography can now help guide early transfusion using the best proportion of red blood cells, plasma and platelets on the basis of the best available evidence. Conclusions. We have some knowledge about the pathophysiology coagulopathy associated with trauma but more research in this field is needed. Rapid diagnosis and immediate intervention are important to improve the outcomes with our patients.


Assuntos
Humanos , Masculino , Feminino , Adolescente , Adulto Jovem , Pessoa de Meia-Idade , Hemorragia Cerebral , Traumatismo Cerebrovascular , Hemorragia , Tromboelastografia , Transfusão de Sangue , Hemorragia Cerebral , Traumatismos Craniocerebrais , Transtornos Traumáticos Cumulativos , Traumatismo Múltiplo , Centros de Traumatologia , Índices de Gravidade do Trauma , Ferimentos e Lesões
6.
Enferm Intensiva ; 19(3): 123-29, quiz 130-1, 2008.
Artigo em Espanhol | MEDLINE | ID: mdl-18840327

RESUMO

UNLABELLED: Pressure ulcers (PU) are the most frequent injuries in critical patients whose management is the responsibility of the nurses. The first step for its prevention is to determine the patients at risk; however the usual risk assessment scales (Norton, Braden, etc.) do not have adequate specificity to do this. AIM: To study the validity of a current risk assessment scale of pressure ulcers in intensive care (EVARUCI). DESIGN: Prospective, descriptive study. SUBJECTS: Adult patients admitted to Intensive Care Unit (ICU) in the Hospital of Fuenlabrada without PU from February, the 1st, 2005 to January, the 31st, 2006. Demographic data were obtained from the admission records. Data on EVARUCI were daily collected and the patients were studied until they developed 1 of 2 outcomes: a) they developed a PU, or b) they left the ICU (death or exit to other nursing ward). METHODS: Four validity indexes were used: sensitivity, specificity, positive predictive value and negative predictive value. The area under the curve (AUC) of the receiver operating characteristic (ROC) was also used. These indicators were applied to the mean scores during the entire stay and to the initial and final scores in both groups (PU and NO PU). The SPSS v. 12.0 was used for the statistical analysis. RESULTS: A total of 97 patients were included, 62 of whom finished the study. Eleven patients (17.74%) developed PU. Of these, 57.69% were grade I. The most frequent site was in the sacral area (26.92%) and heels (23.08%). The results of the mean of the scores on the EVARUCI mean, initial and final data were: sensitivity (100%, 100%, 90.91%), specificity (68.63%, 49.02%, 92.16%), positive predictive value (40.74%, 29.73%, 71.43%) and negative predictive value (100%, 100%, 97.2%). AUC of ROC was 0.938, 0.909, 0.952, respectively. CONCLUSIONS: The EVARUCI scale is valid to detect patients at risk of development PU in ICU.


Assuntos
Cuidados Críticos , Prontuários Médicos , Úlcera por Pressão/diagnóstico , Úlcera por Pressão/epidemiologia , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Medição de Risco
7.
Enferm. intensiva (Ed. impr.) ; 19(3): 123-131, jul.-sept. 2008. ilus, tab
Artigo em Es | IBECS | ID: ibc-70744

RESUMO

Las úlceras por presión (UPP) son lesiones másfrecuentes en los pacientes críticos y su manejo escompetencia de la enfermera. El primer paso para suprevención consiste en la determinación del riesgo ypara ello las escalas habituales (Norton, Braden, etc.)no tienen una adecuada especificidad.Objetivo. Determinar la validez de la Escala deValoración Actual del Riesgo de desarrollar Úlceraspor presión en Cuidados Intensivos (EVARUCI).Diseño. Estudio prospectivo descriptivo.Sujetos. Pacientes adultos ingresados en la Unidad deCuidados Intensivos (UCI) del Hospital deFuenlabrada sin UPP entre el 1 de febrero de 2005 yel 31 de enero de 2006. Los datos demográficosfueron obtenidos de admisión y diariamente se evaluóy registró la puntuación obtenida en EVARUCI. Lospacientes siguieron en el estudio hasta quedesarrollaron UPP (grupo UPP), o salieron de la UCIpor muerte o traslado (grupo NO UPP).Metodología. Se emplearon 4 indicadores de validez:sensibilidad, especificidad, valor predictivo positivo yvalor predictivo negativo. También se empleó el áreabajo la curva ROC (receiver operatingcharacteristic). Estos indicadores se aplicaron a lamedia de las puntuaciones durante toda la estancia, ya las puntuaciones iniciales y a las finales en ambosgrupos (UPP y NO UPP); para el análisis estadístico seaplicó el paquete SPSS v. 12.0.Resultados. Noventa y siete pacientes fueronincluidos, de los que 62 finalizaron el estudio.Desarrollaron UPP 11 pacientes (17,74%). El 57,69%fue de grado I; la localización más frecuente fue enzona sacra (26,92%) y talones 23,08%. Los resultadosde la media de las puntuaciones en EVARUCI, laspuntuaciones iniciales y finales fueron: sensibilidad(100%, 100%, 90,91%), especificidad (68,63%,49,02%, 92,16%), valor predictivo positivo (40,74%,29,73%, 71,43%), valor predictivo negativo (100%,100%, 97,2%). El área bajo la curva ROC fue de 0,938,0,909 y 0,952 respectivamente.Conclusiones. La escala EVARUCI es válida para detectarpacientes críticos con riesgo de desarrollar UPP


Aim. To study the validity of a current riskassessment scale of pressure ulcers in intensive care(EVARUCI).Design. Prospective, descriptive study.Subjects. Adult patients admitted to Intensive CareUnit (ICU) in the Hospital of Fuenlabrada withoutPU from February, the 1st, 2005 to January, the 31st,2006. Demographic data were obtained from theadmission records. Data on EVARUCI were dailycollected and the patients were studied until theydeveloped 1 of 2 outcomes: a) they developed a PU,or b) they left the ICU (death or exit to othernursing ward).Methods. Four validity indexes were used:sensitivity, specificity, positive predictive value andnegative predictive value. The area under the curve(AUC) of the receiver operating characteristic(ROC) was also used. These indicators were appliedto the mean scores during the entire stay and to theinitial and final scores in both groups (PU and NOPU). The SPSS v. 12.0 was used for the statisticalanalysis.Results. A total of 97 patients were included, 62 ofwhom finished the study. Eleven patients (17.74%)developed PU. Of these, 57.69% were grade I. Themost frequent site was in the sacral area (26.92%)and heels (23.08%). The results of the mean of thescores on the EVARUCI mean, initial and final datawere: sensitivity (100%, 100%, 90.91%), specificity(68.63%, 49.02%, 92.16%), positive predictive value(40.74%, 29.73%, 71.43%) and negative predictivevalue (100%, 100%, 97.2%). AUC of ROC was 0.938,0.909, 0.952, respectively.Conclusions. The EVARUCI scale is valid to detectpatients at risk of development PU in ICU


Assuntos
Humanos , Cuidados Críticos/métodos , Úlcera por Pressão/epidemiologia , Risco Ajustado/métodos , Fatores de Risco , Reprodutibilidade dos Testes , Cuidados de Enfermagem/métodos
9.
Anim Genet ; 39(3): 267-77, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18454804

RESUMO

The black tiger shrimp (Penaeus monodon) is an ecologically and economically important penaeid species and is widely distributed in the Indo-Pacific region. Here we investigated the genetic diversity of P. monodon (n = 355) from eight geographical regions by genotyping at 10 microsatellite loci. The average observed heterozygosity at various loci ranged from 0.638 to 0.743, indicating a high level of genetic variability in this region. Significant departures from Hardy-Weinberg equilibrium caused by heterozygote deficiency were recorded for most loci and populations. Pairwise F(ST) and R(ST) values revealed genetic differentiation among the populations. Evidence from the assignment test showed that the populations in the West Indian Ocean were unique, whereas other populations examined were partially admixed. In addition, the non-metric multidimensional scaling analysis indicated the presence of three geographic groups in the Indo-Pacific region, i.e. the African populations, a population from western Thailand and the remaining populations as a whole. We also sequenced and analysed the mitochondrial control region (mtCR) in these shrimp stocks to determine whether the nuclear and mitochondrial genomes show a similar pattern of genetic differentiation. A total of 262 haplotypes were identified, and nucleotide divergence among haplotypes ranged from 0.2% to 16.3%. Haplotype diversity was high in all populations, with a range from 0.969 to 1. Phylogenetic analysis using the mtCR data revealed that the West Indian Ocean populations were genetically differentiated from the West Pacific populations, consistent with the microsatellite data. These results should have implications for aquaculture management and conservation of aquatic diversity.


Assuntos
DNA Mitocondrial/genética , Repetições de Microssatélites/genética , Penaeidae/classificação , Penaeidae/genética , Animais , Variação Genética , Genética Populacional , Genoma , Genoma Mitocondrial , Haplótipos , Oceano Índico , Região de Controle de Locus Gênico , Oceano Pacífico , Polimorfismo Genético
10.
J Chem Phys ; 123(14): 144506, 2005 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-16238406

RESUMO

Quantum and classical simulations are carried out on ice Ih over a range of temperatures utilizing the TIP4P water model. The rigid-body centroid molecular dynamics method employed allows for the investigation of equilibrium and dynamical properties of the quantum system. The impact of quantization on the local structure, as measured by the radial and spatial distribution functions, as well as the energy is presented. The effects of quantization on the lattice vibrations, associated with the molecular translations and librations, are also reported. Comparison of quantum and classical simulation results indicates that shifts in the average potential energy are equivalent to rising the temperature about 80 K and are therefore non-negligible. The energy shifts due to quantization and the quantum mechanical uncertainties observed in ice are smaller than the values previously reported for liquid water. Additionally, we carry out a comparative study of melting in our classical and quantum simulations and show that there are significant differences between classical and quantum ice.

11.
J Phys Chem A ; 109(32): 7236-41, 2005 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-16834088

RESUMO

The results of classical and quantum simulations of liquid water over a wide range of temperatures are compared to probe the impact of quantization on the properties of liquid water. We show that, when treated quantum mechanically, water molecules have an enhanced probability of accessing nontetrahedral coordination in the local three-dimensional structure. We discuss how this enhanced probability, also called "effective tunneling", is related to the dynamics of the hydrogen-bond breaking and molecular diffusion in the liquid. We explore in detail how local molecular environments affect the manifestation of quantum effects and identify a previously unreported and apparently unique behavior of the quantum mechanical uncertainty of the water molecule as a function of temperature. The nonmonotonic behavior of the quantum mechanical uncertainty with temperature is shown to be due to the notable strength of the water-water interaction in the condensed phase and becomes further evidence of the importance of the water structure in the properties of this ubiquitous liquid.

12.
Phys Rev E Stat Nonlin Soft Matter Phys ; 72(6 Pt 2): 066605, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16486076

RESUMO

We study the behavior of scarlets of a stochastic radiation field of fixed frequency in the presence of a slit pierced on an infinitely thin metallic screen of ideal conductivity. Our methodology involves the exact solution of the Maxwell equations with appropriate boundary conditions, the only approximations being those due to the numerical procedure. Our numerical simulations show that the field is unfolded into two components, a dominant one that is disordered and a weaker one that is ordered. The former still presents scarlets although modified, while the latter exhibits a pattern of perfectly coherent diffraction. Due to the dominant character of the disordered component, the general appearance of the scattered field is stochastic; however, an underlying order exists. Our results confirm, thus, a novel effect suggested previously in the context of stochastic electrodynamics.

13.
J Chem Phys ; 121(12): 5992-6002, 2004 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-15367027

RESUMO

The centroid molecular dynamics (CMD) method is applied to the study of liquid water in the context of the rigid-body approximation. This rigid-body CMD technique, which is significantly more efficient than the standard CMD method, is implemented on the TIP4P model for water and used to examine isotopic effects in the equilibrium and dynamical properties of liquid H(2)O and D(2)O. The results obtained with this approach compare remarkably well with those determined previously with path integrals simulations as well as those obtained from the standard CMD method employing flexible models. In addition, an examination of the impact of quantization on the rotational and librational motion of the water molecule is also reported.

14.
Bioelectrochemistry ; 60(1-2): 81-6, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12893313

RESUMO

The action of electromagnetic fields (EMF) on different pathways related to cell physiology, proliferation, toxicity of chemicals, gene expression, etc., are currently being investigated although the results are still not conclusive and even conflicting. In laboratory and animal studies, EMF has been found to produce a great variety of effects such as: increase in ornithine decarboxylase activity in breast, increase in beta-galactosidase gene expression and oncogene transcription after exposure to 50/60 Hz. Animal studies have shown that the use of EMF can enhance drug delivery across biological barriers (rat abdominal skin), using benzoic acid as the drug candidate. It has been reported by different authors that pulsed EMF (PEMF) can produce alterations in antineoplastic drugs potency. In the present study, we investigated the effects of PEMF on methotrexate cytotoxicity in MCF-7 breast cancer cells and the effects with simultaneous exposure to FeCl3. The data presented in the current report indicate that PEMF (25 Hz, 1.5 mT) do not induce modulation of the action of methotrexate (with and without iron-III) in MCF-7 cells when they are exposed to PEMF for 2 h/day during 3 days.


Assuntos
Neoplasias da Mama/patologia , Compostos Férricos/toxicidade , Magnetismo , Metotrexato/toxicidade , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Cloretos , Humanos
15.
Bioelectromagnetics ; 23(8): 578-85, 2002 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12395412

RESUMO

The resistance of tumor cells to antineoplastic agents is a major obstacle during cancer chemotherapy. Many authors have observed that some exposure protocols to pulsed electromagnetic fields (PEMF) can alter the efficacy of anticancer drugs; nevertheless, the observations are not clear. We have evaluated whether a group of PEMF pulses (1.5 mT peak, repeated at 1 and 25 Hz) produces alterations of drug potency on a multidrug resistant human colon adenocarcinoma (HCA) cell line, HCA-2/1(cch). The experiments were performed including (a) exposures to drug and PEMF exposure for 1 h at the same time, (b) drug exposure for 1 h, and then exposure to PEMF for the next 2 days (2 h/day). Drugs used were vincristine (VCR), mitomycin C (MMC), and cisplatin. Cell viability was measured by the neutral red stain cytotoxicity test. The results obtained were: (a) The 1 Hz PEMF increased VCR cytotoxicity (P < 0.01), exhibiting 6.1% of survival at 47.5 microg/ml, the highest dose for which sham exposed groups showed a 19.8% of survival. For MMC at 47.5 microg/ml, the % of survival changed significantly from 19.2% in sham exposed groups to 5.3% using 25 Hz (P < 0.001). Cisplatin showed a significant reduction in the % of survival (44.2-39.1%, P < 0.05) at 25 Hz and 47.5 microg/ml, and (b) Minor significant alterations were observed after nonsimultaneous exposure of cells to PEMF and drug. The data indicate that PEMF can induce modulation of cytostatic agents in HCA-2/1(cch), with an increased effect when PEMF was applied at the same time as the drug. The type of drug, dose, frequency, and duration of PEMF exposure could influence this modulation.


Assuntos
Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/radioterapia , Antineoplásicos/administração & dosagem , Resistência a Múltiplos Medicamentos/efeitos da radiação , Campos Eletromagnéticos , Adenocarcinoma/patologia , Antineoplásicos/efeitos da radiação , Apoptose/efeitos da radiação , Divisão Celular/efeitos da radiação , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Cisplatino/administração & dosagem , Cisplatino/efeitos da radiação , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/patologia , Neoplasias do Colo/radioterapia , Relação Dose-Resposta a Droga , Relação Dose-Resposta à Radiação , Humanos , Magnetismo/uso terapêutico , Mitomicina/administração & dosagem , Mitomicina/efeitos da radiação , Valores de Referência , Sensibilidade e Especificidade , Fatores de Tempo , Células Tumorais Cultivadas/efeitos dos fármacos , Células Tumorais Cultivadas/efeitos da radiação , Vincristina/administração & dosagem , Vincristina/efeitos da radiação
16.
Bioelectrochemistry ; 53(1): 137-40, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11206921

RESUMO

It is reported that exposure to 50 Hz extremely low-frequency electromagnetic field (ELF-EMF) can produce apoptosis and small variations in cell cycle distribution on different cell lines. In order to study the effect of ELF-EMF on tumoral cells in vitro, two cell lines (U-937, from a histiocytic lymphoma, and HCA-2/1cch, from a human colon adenocarcinoma) were exposed to 25 Hz, 1.5 mT, for 2 h and 45 min. Cell cycle distribution, apoptosis (spontaneous and dexamethasone-induced) and cell growth were evaluated. Neither significant alteration in cell cycle phases nor induction of apoptosis was observed. Nevertheless, the relative cell number was found to decrease to 55.84+/-7.35% (p <0.05, Student's t-test) for HCA-2/1cch cells after exposure to EMF in the presence of dexamethasone. The presence of dexamethasone during the EMF exposure could probably produce a decrease in the cell growth of this cell line.


Assuntos
Apoptose/efeitos da radiação , Ciclo Celular/efeitos da radiação , Campos Eletromagnéticos/efeitos adversos , Divisão Celular/efeitos da radiação , Dexametasona/farmacologia , Humanos , Fatores de Tempo , Células Tumorais Cultivadas/efeitos da radiação , Células U937/efeitos da radiação
17.
J Rheumatol ; 27(2): 471-80, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10685816

RESUMO

OBJECTIVE: To characterize and define the phenotypes observed in a large Italo-Argentinean kindred with osteoarthritis, chondrocalcinosis, and Milwaukee shoulder (MS). METHODS: Seventy-five members were evaluated with a history, examination, and radiographs of shoulders, spine, hands, and knees. Superior subluxation of the glenohumeral joint was graded using shoulder radiographs and tomography and nuclear magnetic resonance imaging and 3 dimensional computed tomography was performed on selected members. In 31 family members peripheral blood DNA was utilized for genetic linkage analysis of several candidate gene loci previously linked to chondrocalcinosis phenotypes, as well as those implicated in the proper patterning of skeletal elements and cartilage differentiation. In addition, direct sequence analysis of type II collagen gene (COL2A1), the gene that codes for the major structural protein of cartilage, was undertaken in 3 affected and 3 unaffected members of the family. RESULTS: MS was seen in one member of the first generation and 6 members of the 2nd generation, while 8 members of the 3rd generation showed an incomplete form of MS. Isolated superior subluxation of the shoulder was seen in 16 other family members of the 3rd and 4th generations. Osteoarthritis of the spine and peripheral joints was seen in 31 affected members, while chondrocalcinosis was observed in 6 members of the first generation. Shoulder synovial fluid from 2 patients showed the presence of both apatite and calcium pyrophosphate dihydrate crystals. Direct analysis of the COL2A1 gene indicated no known disease determining mutations in affected members, thus excluding this gene as a candidate gene in this family. Genetic linkage to several candidate loci, including the chondrocalcinosis loci on chromosomes 5p and 8q, as well as loci for HOX A and C were also excluded. Linkage analyses of other loci for the HOX B and D genes and the PAX 1 and 9 genes were uninformative in this kindred. CONCLUSION: This kindred illustrates an unusual type of osteoarthritis with secondary intraarticular and periarticular calcification and MS in the most severely affected elderly members. A search for linkage to some potential candidate genes was either excluded or uninformative. Further linkage analysis to identify potential candidate genes is in progress.


Assuntos
Apatitas/metabolismo , Pirofosfato de Cálcio/metabolismo , Osteoartrite/metabolismo , Articulação do Ombro/metabolismo , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Osteoartrite/genética , Osteoartrite/fisiopatologia , Linhagem , Fatores de Risco , Articulação do Ombro/patologia , Articulação do Ombro/fisiopatologia
18.
Enferm Infecc Microbiol Clin ; 18(10): 493-5, 2000 Dec.
Artigo em Espanhol | MEDLINE | ID: mdl-11197998

RESUMO

BACKGROUND: Retrospective study of the varicella pneumonia in adults with clinical, therapeutic and evolutive features in 22 patients in the last 5 years. MATERIAL AND METHODS: The diagnosis was established by clinical and radiologic criteria in the course of varicella infection. The antecedents of pregnancy, smoking habit, previous contact with patients with varicella and underlying disease were evaluated. RESULTS: Twenty-two patients (14 males and 8 women: mean age 31 years. range: 22-40) were included in the study. None of them were immunocompromised, 16 (72.7%) have had previous contact with varicella patients. 19 (86.3%) were heavy smokers and none of the female patients was pregnant. All patients had fever and exanthem, cough had 20 (90.9%) dyspnea 16 (72.7%), chest pain 9 (40.9%) and hemoptysis 5 (22.7%). Only two patients showed pO2 < 60 mmHg. Chest X-ray revealed an interstitial pattern in 14 cases (63.3%), and micronodular in 8 (36.3%). All patients received treatment with intravenous acyclovir. Three patients (13.6%) were admitted to the Intensive Care Unit due to respiratory insufficiency, needing mechanical ventilation one of them (4.5%). Another three developed failure renal reversible associated with acyclovir. All patients had a favourable clinical course. CONCLUSIONS: We believe, that early, aggressive use of intravenous acyclovir in adult varicella pneumonia may be lifesaving, preventing progressive respiratory failure and reducing the high mortality rate of the disease. Therapy with corticosteroids should be considered in addition to antiviral therapy in patients with severe varicella pneumonia. While oral acyclovir chemoprophylaxis is probably beneficial in populations with chicken pox.


Assuntos
Varicela/complicações , Pneumonia Viral/etiologia , Aciclovir/uso terapêutico , Adulto , Antivirais/uso terapêutico , Varicela/tratamento farmacológico , Feminino , Humanos , Masculino , Pneumonia Viral/tratamento farmacológico , Estudos Retrospectivos
19.
Genomics ; 62(2): 177-83, 1999 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-10610710

RESUMO

The gene for familial chondrocalcinosis (MIM 118600; gene symbol CCAL2) has been localized to a 0.8-cM interval on the short arm of chromosome 5, between the polymorphic microsatellite markers D5S416 and D5S2114. We have undertaken the physical and transcript mapping of this interval, as well as regions telomeric to the interval, in an attempt to define ultimately the gene for this disorder. The physical map is composed of YAC, BAC, PAC, and cosmid resources and spans a physical distance of approximately 0.3 Mb. Using cDNA selection, we have identified eight novel transcripts in and around the interval; two of the selected transcripts reside in the candidate interval. We have also more precisely placed several expressed sequence tags (ESTs) that were previously mapped by radiation hybrid analysis and were reported to reside in or near the candidate interval. Two of the ESTs analyzed overlap with the selected cDNAs that reside in the candidate interval. All of the selected cDNAs are expressed partial transcripts, as determined by Northern blot analysis, and using RT-PCR analysis, we have determined that the cDNAs that reside in the candidate interval are expressed in cartilage and synovium, tissues that are presumably relevant to the chondrocalcinosis phenotype.


Assuntos
Condrocalcinose/genética , Cromossomos Humanos Par 5/genética , DNA Complementar/genética , Mapeamento Físico do Cromossomo , Transcrição Gênica , Adulto , Northern Blotting , Mapeamento de Sequências Contíguas , Cosmídeos , DNA Complementar/química , Etiquetas de Sequências Expressas , Humanos , Dados de Sequência Molecular , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Homologia de Sequência do Ácido Nucleico
20.
Arthritis Rheum ; 42(10): 2139-44, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10524685

RESUMO

OBJECTIVE: To map the gene for human cartilage intermediate layer protein (CILP) in order to assess its involvement in some familial forms of calcium pyrophosphate dihydrate (CPPD) deposition disease. METHODS: A radiation hybrid panel was analyzed for chromosomal assignment of the CILP gene within a 1-cM limit of resolution. The location of the gene for CILP was confirmed to reside at the observed radiation hybrid locus by fluorescence in situ hybridization. RESULTS: The human CILP gene resides at chromosome 15q21. CONCLUSION: This map location definitively excludes mutations in the CILP gene as the cause of certain familial forms of CPPD deposition disease that have been genetically mapped to chromosomes 8q and 5p.


Assuntos
Condrocalcinose/genética , Cromossomos Humanos Par 5 , Cromossomos Humanos Par 8 , Proteínas da Matriz Extracelular/genética , Glicoproteínas/genética , Pirofosfatases , Sequência de Bases , Mapeamento Cromossômico , Humanos , Hibridização in Situ Fluorescente , Dados de Sequência Molecular , Reação em Cadeia da Polimerase
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