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1.
Free Radic Biol Med ; 122: 130-136, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29410312

RESUMO

Ascorbic acid (AA) is a major redox buffer in plant cells. The role of ethylene in the redox signaling pathways that influence photosynthesis and growth was explored in two independent AA deficient Arabidopsis thaliana mutants (vtc2-1 and vtc2-4). Both mutants, which are defective in the AA biosynthesis gene GDP-L-galactose phosphorylase, produce higher amounts of ethylene than wt plants. In contrast to the wt, the inhibition of ethylene signaling increased leaf conductance, photosynthesis and dry weight in both vtc2 mutant lines. The AA-deficient mutants showed altered expression of genes encoding proteins involved in the synthesis/responses to phytohormones that control growth, particularly auxin, cytokinins, abscisic acid, brassinosterioids, ethylene and salicylic acid. These results demonstrate that AA deficiency modifies hormone signaling in plants, redox-ethylene interactions providing a regulatory node controlling shoot biomass accumulation.


Assuntos
Proteínas de Arabidopsis/genética , Ácido Ascórbico/metabolismo , Etilenos/metabolismo , Monoéster Fosfórico Hidrolases/genética , Reguladores de Crescimento de Plantas/metabolismo , Ácido Abscísico/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Ácido Ascórbico/genética , Biomassa , Regulação da Expressão Gênica de Plantas , Mutação , Oxirredução , Monoéster Fosfórico Hidrolases/metabolismo , Fotossíntese/genética , Reguladores de Crescimento de Plantas/genética , Ácido Salicílico/metabolismo , Transdução de Sinais/genética
2.
Plant Physiol Biochem ; 104: 29-35, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27010742

RESUMO

Ascorbic acid (AA) is synthesized in plant mitochondria through the oxidation of l-galactono-1,4-lactone (l-GalL) and then distributed to different cell compartments. AA-deficient Arabidopsis thaliana mutants (vtc2) and exogenous applications of l-GalL were used to generate plants with different AA content in their leaves. This experimental approach allows determining specific AA-dependent effects on carbon metabolism. No differences in O2 uptake, malic and citric acid and NADH content suggest that AA synthesis or accumulation did not affect mitochondrial activity; however, l-GalL treatment increased CO2 assimilation and photosynthetic electron transport rate in vtc2 (but not wt) leaves demonstrating a stimulation of photosynthesis after l-GalL treatment. Increased CO2 assimilation correlated with increased leaf stomatal conductance observed in l-GalL-treated vtc2 plants.


Assuntos
Arabidopsis/fisiologia , Ácido Ascórbico/biossíntese , Mitocôndrias/metabolismo , Fotossíntese , Arabidopsis/efeitos dos fármacos , Respiração Celular/efeitos dos fármacos , Ácido Desidroascórbico/metabolismo , Glutationa/metabolismo , Lactonas/farmacologia , Mitocôndrias/efeitos dos fármacos , Fotossíntese/efeitos dos fármacos , Estômatos de Plantas/efeitos dos fármacos , Estômatos de Plantas/fisiologia , Piridinas/farmacologia , Ribulose-Bifosfato Carboxilase/metabolismo , Açúcares Ácidos/farmacologia
3.
Transfus Clin Biol ; 21(4-5): 158-61, 2014 Nov.
Artigo em Francês | MEDLINE | ID: mdl-25282487

RESUMO

The act to transfuse is a prescription following basic rules similar to drug prescriptions. If harm happens, potentially linked with this prescription, the harm's responsibility is borne by the physician, the paramedics, the care organization but by the supplier laboratory too. The setting of good practice rules consistent with science data at the time when the act is performed, the respect of the patient's rights and the quality of supplied products will be assessed during the expertise. Under restorative responsibility, it is necessary to previously establish a direct and certain causation between the litigious act and the harm to enforce the vicarious liability. Nowadays, legal precedents grant a larger protection to more and more numerous victims, enhancing the field of the fault with the appeal to assumption of fault. At the same time, the lawmaker himself promulgated objective conditions of compensation for many categories of victims of medical risk from which transfused people are part. The law of March the 4th of 2002 went one step closer devoting a new foundation of compensation: national solidarity.


Assuntos
Segurança do Sangue , Transfusão de Sangue/legislação & jurisprudência , Imperícia , Prescrições , Responsabilidade Social , Pessoal Técnico de Saúde , Bancos de Sangue , Segurança do Sangue/normas , Transfusão de Sangue/normas , Patógenos Transmitidos pelo Sangue , Causalidade , Compensação e Reparação/legislação & jurisprudência , Erros de Diagnóstico , Transmissão de Doença Infecciosa/legislação & jurisprudência , Transmissão de Doença Infecciosa/prevenção & controle , França , Humanos , Prescrição Inadequada/legislação & jurisprudência , Erros Médicos , Guias de Prática Clínica como Assunto , Prescrições/normas , Parceiros Sexuais , Reação Transfusional , Recusa do Paciente ao Tratamento/legislação & jurisprudência
5.
Artigo em Espanhol | LILACS, BINACIS | ID: biblio-1170982

RESUMO

UNLABELLED: The incidence rate of invasive infections due to Candida species has increased drastically in the last 20 years, causing a 40


mortality rate in hospitalized patients. In order to comprehend the epidemiology of Candida bloodstream infection, the study was carried out. MATERIALS AND METHODS: A retrospective study was done based on microbiology laboratory reports from five terciary care hospitals from the city of Cordoba between January 2010 and August 2012. RESULTS: 158 patients had candidemia, the average age was 55,8 years, and 54


of patients were in the intensive care unit. Candida albicans (44


) and Candida tropicalis (12


) were the main fungi isolated. Candida parapsilosis was commonly associated with catether infections. CONCLUSIONS: The data from the city of Cordoba showed that C. albicans, C. parapsilosis y C. tropicalis were the more frequent species isolated from blood cultures. This is similar to what is seen in other series published from Argentina and Latinamerica. This study may have implications when it comes to deciding which empiric antifugal agent is best for the treatment of candidemia.


Assuntos
Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Candidemia/epidemiologia , Argentina/epidemiologia , Vigilância da População , Incidência , Estudos Retrospectivos , Candidemia/microbiologia
6.
J Visc Surg ; 150(6): 383-8, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24012165

RESUMO

Adjustable gastric banding is recognized for its effectiveness in obtaining long-term weight loss with low morbidity-mortality for patients with morbid obesity. However, life-threatening complications can sometimes occur, and surgeons may end up in court. We analyzed complications, some of them lethal, arising from gastric banding surgery in nine patients and the main issues identified by the experts, contributing to the judge's decision. Gastric banding is considered a benign operation, but, of the nine cases examined herein, five resulted in death while the other four had serious consequences with several damages, especially aesthetic and psychological suffering. Perforations of the oesophagus or stomach remain the leading causes of complications; the experts identified several issues from the records that helped the judge to render a decision and condemn seven of the nine surgeons. Three types of faults were considered the responsibility of the doctors: the lack of patient information or incomplete medical records, a clumsy mistake or delay of appropriate treatment due to underestimation of clinical symptoms, and finally, failure to observe the proper indications. Expert opinion focused most often on criticism of postoperative behaviour and failure to make decisions according to the state of the art.


Assuntos
Gastroplastia/efeitos adversos , Responsabilidade Legal , Obesidade Mórbida/cirurgia , Complicações Pós-Operatórias/cirurgia , Adulto , Índice de Massa Corporal , Feminino , Seguimentos , Gastroplastia/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Obesidade Mórbida/diagnóstico , Obesidade Mórbida/mortalidade , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/mortalidade , Reoperação , Estudos Retrospectivos , Medição de Risco , Taxa de Sobrevida , Adulto Jovem
7.
J Chir (Paris) ; 145(5): 442-6, 2008.
Artigo em Francês | MEDLINE | ID: mdl-19106864

RESUMO

Compensation for victims of medical accidents identified as no-fault medical accidents (NFMA) will be financed by national solidarity: this is a major and innovative feature of the Law of March 4, 2002 relative to Patients' Rights. In this review, we analyse the decisions of the regional commission on compensation of medical accidents in the Provence-Alpes-Côtes d'Azur (PACA) region of France in 2004 and 2005, and we attempt to identify the prevalence of certain surgical procedures liable to result in NFMA and to define the concept of "unintended consequences" in the context of state of health of the patient and the predictable course of the malady. We hope to improve the medical information given to the patient and thereby the overall quality of management. NFMA was acknowledged in 57 claims, about 10% of all those received by the commission during this period. Nearly half of the claims were within the competence of the commission because of the existence of serious sequelae (Permanent Partial Disability) in 47%. No typical profile of age or gender emerged in the patients with NFMA. The majority of cases occurred after surgical procedures, in particular gastrointestinal surgery and orthopaedic surgery; 91% were planned procedures. We did not identify increased risk related to any given type of surgery, particular disease condition, or precise anatomic region. Complications were those usually observed such as neurological complications in vascular surgery or perforations in gastrointestinal surgery. The interpretation of NFMA has undergone an evolution during this two-year period. In 2004, previous poor health status precluded acknowledgment of a medical accident, the argument being that there was a predisposition to the complication which occurred. In 2005, compensation was based on a reduced Partial Permanent Disability score compared to the patient's previous health status. This became a means of measuring the impact of the medical complication on an already predictably unfavorable clinical course without medical intervention, and the legal aspect of the "ineluctable nature" of this course.


Assuntos
Compensação e Reparação , Erros Médicos/economia , Adulto , Idoso , Idoso de 80 Anos ou mais , Procedimentos Cirúrgicos do Sistema Digestório/efeitos adversos , Procedimentos Cirúrgicos do Sistema Digestório/estatística & dados numéricos , Feminino , França , Gastroenteropatias/complicações , Gastroenteropatias/cirurgia , Humanos , Responsabilidade Legal , Masculino , Erros Médicos/legislação & jurisprudência , Prontuários Médicos , Pessoa de Meia-Idade , Doenças Musculoesqueléticas/complicações , Doenças Musculoesqueléticas/cirurgia , Procedimentos Ortopédicos/efeitos adversos , Procedimentos Ortopédicos/estatística & dados numéricos , Direitos do Paciente , Estudos Retrospectivos
8.
Phys Med Biol ; 52(9): 2599-613, 2007 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-17440255

RESUMO

Various instruments based on acquisition and elaboration of images of pigmented skin lesions have been developed in an attempt to in vivo establish whether a lesion is a melanoma or not. Although encouraging, the response of these instruments, e.g. epiluminescence microscopy, reflectance spectrophotometry and fluorescence imaging, cannot currently replace the well-established diagnostic procedures. However, in place of the approach to instrumentally assess the diagnosis of the lesion, recent studies suggest that instruments should rather reproduce the assessment by an expert clinician of whether a lesion has to be excised or not. The aim of this study was to evaluate the performance of a spectrophotometric system to mimic such a decision. The study involved 1794 consecutively recruited patients with 1966 doubtful cutaneous pigmented lesions excised for histopathological diagnosis and 348 patients with 1940 non-excised lesions because clinically reassuring. Images of all these lesions were acquired in vivo with a multispectral imaging system. The data set was randomly divided into a train (802 reassuring and 1003 excision-needing lesions, including 139 melanomas), a verify (464 reassuring and 439 excision-needing lesions, including 72 melanomas) and a test set (674 reassuring and 524 excision-needing lesions, including 76 melanomas). An artificial neural network (ANN(1)) was set up to perform the classification of the lesions as excision-needing or reassuring, according to the expert clinicians' decision on how to manage each examined lesion. In the independent test set, the system was able to emulate the clinicians with a sensitivity of 88% and a specificity of 80%. Of the 462 correctly classified as excision-needing lesions, 72 (95%) were melanomas. No major variations in receiver operating characteristic curves were found between the test and the train/verify sets. On the same data set, a further artificial neural network (ANN(2)) was then architected to perform classification of the lesions as melanoma or non-melanoma, according to the histological diagnosis. Having set the sensitivity in recognizing melanoma to 95%, ANN(1) resulted to be significantly better in the classification of reassuring lesions than ANN(2). This study suggests that multispectral image analysis and artificial neural networks could be used to support primary care physicians or general practitioners in identifying pigmented skin lesions that require further investigations.


Assuntos
Melanoma/diagnóstico , Redes Neurais de Computação , Neoplasias Cutâneas/diagnóstico , Pigmentação da Pele , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Espectrofotometria
9.
Br J Dermatol ; 155(3): 570-3, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16911283

RESUMO

BACKGROUND: Very small pigmented lesions may represent an important diagnostic challenge to the clinician. OBJECTIVES: The aim of the present study was to establish the diagnostic value, in terms of sensitivity and specificity, of both clinical and dermoscopic examinations in a population of patients with unselected consecutive pigmented lesions with a maximum clinical diameter of 3 mm. PATIENTS AND METHODS: Two hundred and four consecutive patients bearing 206 pigmented skin lesions with a maximum diameter of 3 mm were seen and operated on. Twenty-three of these lesions were melanomas. Each lesion was subjected to both clinical and dermoscopic evaluation before surgery. The results were expressed in terms of sensitivity and specificity of both kinds of evaluation. RESULTS: Clinical evaluation produced a diagnostic sensitivity of 43% and a specificity of 91%. Dermoscopy resulted in a sensitivity of 83% and in a specificity of 69%. The comparison between the sensitivity values of the two diagnostic methods showed a significant difference (P < 0.01). A high value of significance was also obtained comparing the respective specificity values (P < 0.001). CONCLUSIONS: Detection of very small melanomas is feasible by accurate visual inspection. Dermoscopy appears to be an important aid to diagnosis, provided that physicians are aware of this type of lesion and maintain the index of suspicion at a high level.


Assuntos
Melanoma/patologia , Neoplasias Cutâneas/patologia , Adolescente , Adulto , Idoso , Criança , Dermoscopia , Diagnóstico Diferencial , Humanos , Pessoa de Meia-Idade , Nevo Pigmentado/patologia , Estudos Retrospectivos , Sensibilidade e Especificidade
10.
Oncogene ; 25(19): 2818-26, 2006 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-16314830

RESUMO

Glioblastoma (GBM) is a highly malignant glioma, which has the propensity to infiltrate throughout the brain in contrast to pilocytic astrocytoma (PA) of the posterior fossa, which does not spread and can be cured by surgery. We have used Suppression Subtractive Hybridization to define markers that better delineate the molecular basis of brain invasion and distinguish these tumor groups. We have identified 106 genes expressed in PA versus GBM and 80 genes expressed in GBM versus PA. Subsequent analysis identified a subset of 20 transcripts showing a common differential expression pattern for the two groups. GBM differs from PA by the expression of five genes involved in invasion and angiogenesis: fibronectin, osteopontin, chitinase-3-like-1 (YKL-40), keratoepithelin and fibromodulin. PA differs from GBM by the expression of genes related to metabolism (apolipoprotein D), proteolysis (protease-serine-11), receptor and signal transduction (PLEKHB1 for Pleckstrin-Homology-domain-containing-protein-family-B-member-1), transcription/translation (eukaryotic-translation-elongation-factor-1-alpha1) processes and cell adhesion (SPOCK1 for SPARC/Osteonectin-CWCV-kazal-like-domains-proteoglycan). The expression of these genes was confirmed by real-time quantitative RT-PCR and immunohistochemistry. This study highlights the crucial role of brain invasion in GBM and identifies specific molecules involved in this process. In addition, it offers a restricted list of markers that accurately distinguish PA from GBM.


Assuntos
Astrocitoma/genética , Perfilação da Expressão Gênica , Genes Neoplásicos/fisiologia , Glioblastoma/genética , Idoso , Astrocitoma/metabolismo , Astrocitoma/patologia , Biomarcadores Tumorais , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Pré-Escolar , Feminino , Regulação Neoplásica da Expressão Gênica , Glioblastoma/metabolismo , Glioblastoma/patologia , Humanos , Masculino , Hibridização de Ácido Nucleico , Análise de Sequência com Séries de Oligonucleotídeos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Neoplásico/genética , RNA Neoplásico/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Técnica de Subtração
11.
Med Sci Law ; 45(3): 211-8, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16117281

RESUMO

The regional commission for conciliation and compensation for medical accidents, iatrogenic diseases and nosocomial infections (commission régionale de conciliation et d'indemnisation des accidents médicaux, affections iatrogènes et infections nosocomiales, CRCI) offers victims of such events the possibility of obtaining compensation without recourse to legal proceedings. We suggest various points of view about this commission set up by the French law no. 2002-303 of 4 March 2002: the composition, role and competence of the CRCI; the place of the expert's report; the opinion pronounced by the CRCI and its outcome, the compensation of victims and, finally, interaction with other procedures.


Assuntos
Compensação e Reparação/legislação & jurisprudência , Infecção Hospitalar , Erros Médicos , França , Humanos , Doença Iatrogênica
12.
Tumori ; 89(4 Suppl): 273-5, 2003.
Artigo em Italiano | MEDLINE | ID: mdl-12903619

RESUMO

In the National Cancer Institute and S Pio X Hospital series we registered 981 patients with primary cutaneous melanoma and no evidence of clinically detectable regional node metastases underwent sentinel node (SN) dissection to microscopically define the tumor status of the regional lymph nodes. In 62.2% of cases, only one SN was detected; 26.4% of patients had two SNs and 11.4% had three or more SNs. A positive SNB was demonstrated in 18.1%. Analysis of survival indicated that the tumor status of the nodes was the most important prognostic factor. Breslow's thickness had a significant impact on survival in tumors of 4 mm or thicker, and ulceration dropped to a borderline significant P-value. To assess the tumor burden in positive SNB, all slides (148 SN pos) were reviewed. Twenty per cent of these patients had evidence of metastasis in other nodes. Of the remaining 80% with a single tumor-involved SN, 62% had a single metastatic deposit. Preliminary data from this study indicate that several subgroups may be identified among patients with 1 positive node, but adequate analysis of survival requires a larger number of patients and a multicentric study.


Assuntos
Metástase Linfática/patologia , Melanoma/secundário , Estadiamento de Neoplasias/métodos , Biópsia de Linfonodo Sentinela , Neoplasias Cutâneas/patologia , Humanos , Metástase Linfática/diagnóstico por imagem , Melanoma/diagnóstico , Melanoma/mortalidade , Melanoma/patologia , Melanoma/cirurgia , Análise Multivariada , Radiografia , Estudos Retrospectivos , Análise de Sobrevida , Taxa de Sobrevida
13.
Rev Neurol (Paris) ; 158(10 Pt 1): 934-47, 2002 Oct.
Artigo em Francês | MEDLINE | ID: mdl-12407302

RESUMO

Dermatomyositis (DM) and polymyositis (PM) are the two main forms of idiopathic inflammatory myopathies. They have in common a proximal muscle weakness, but skin manifestations, juvenile forms and increased incidence of malignancies are clinical characteristics of DM. The follow up of creatine-kinases is the best biological test in spite of their possible normality. The significance of antibodies titers is uncertain, except the association Jo-1 interstitial and lung disease indicating a poor prognosis. The association with HLA haplotypes expresses a genetic predisposition of a dysimmunity to develop DM or PM. Pathological changes are well known with a humoral immune effector mechanism in DM, and a muscle fibre aggression by CD8 + T cells in PM. Non inflammatory forms of DM and PM and rhabdomyolytic forms of PM are not very rare, they are recognized by the HLA class 1 immunoreactivity. Pathophysiological processes involve muscle fibers, inflammatory cells and endothelial cells of capillaries, with a complex intervention of cytokines, adhesion molecules, MHC classe 1, membrane attack complex, anti endothelial cells antibodies, perforin secretion and sometimes apoptotic Fas-mediated mechanisms. Despite these recent advances, causal antigens and activator processes of endothelial cell lysis and autoinvasive cytotoxicity of muscle fibers remain to be identified.


Assuntos
Dermatomiosite/patologia , Polimiosite/patologia , Biomarcadores , Dermatomiosite/genética , Dermatomiosite/imunologia , Progressão da Doença , Eletrofisiologia , Humanos , Polimiosite/genética , Polimiosite/imunologia
14.
Melanoma Res ; 12(3): 279-86, 2002 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12140385

RESUMO

Early detection and prompt excision of cutaneous melanoma is of paramount importance to improve patient survival, and the clinician should be aware of the clinical features that suggest the presence of a malignant lesion. The clinical diagnosis is mainly based on observation of the colour and shape of a given skin lesion. Unfortunately, evaluation of a pigmented lesion is to a large extent subjective and is closely related to the experience of the clinician. To overcome this problem, optical imaging techniques using different instrumentation (i.e. colour video camera, epiluminescence microscopy, reflectance spectrophotometry) and computer image analysis have been proposed in an attempt to provide quantitative measurements in an objective and reproducible fashion. The different procedures employed to perform the diagnosis automatically all have a common denominator: mimicking the eye and the brain of the clinician by image processing and computerized analysis programs, respectively. Sensitivity and specificity data reported in the literature suggest that the computer-based diagnosis of melanoma does not greatly differ from the diagnostic capability of an expert clinician, and is independent of the optical acquisition method employed to analyse the lesions. Most of the computer-processed morphometric variables useful in automated diagnosis are not recognizable nor can be objectively evaluated by the human eye, except that of lesion dimension. However, several questions should be answered before assessing the actual usefulness, including the potential and limitations, of computer-based diagnostic procedures. The purpose of this study was to briefly review the different kinds of instrumentation being used to diagnose melanoma, and to raise questions and whenever possible provide answers in an attempt to establish whether there will be a future for these computerized systems.


Assuntos
Interpretação de Imagem Assistida por Computador , Melanoma/diagnóstico , Neoplasias Cutâneas/diagnóstico , Automação , Cor , Fluorometria , Humanos , Processamento de Imagem Assistida por Computador , Melanoma/patologia , Microscopia/instrumentação , Microscopia/métodos , Sensibilidade e Especificidade , Neoplasias Cutâneas/patologia , Espectrofotometria/instrumentação , Espectrofotometria/métodos , Tomografia/métodos , Gravação de Videoteipe
15.
Anticancer Res ; 22(1A): 433-8, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12017328

RESUMO

Accurate and reliable decision making in breast cancer prognosis can help in the planning of suitable surgery and therapy and, generally, optimise patient management through the different stages of the disease. In recent years, several prognostic factors have been used as indicators of disease progression in breast cancer. In this paper we investigate a fuzzy method, namely fuzzy k-nearest neighbour technique for breast cancer prognosis, and for determining the significance of prognostic markers and subsets of the markers, which include histology type, tumour grade, DNA ploidy, S-phase fraction, G0G1/G2M ratio, and minimum (start) and maximum (end) nuclear pleomorphism indices. We also compare the method with (a) logistic regression as a statistical method, and (b) multilayer feed forward backpropagation neural networks as an artificial neural network tool, the latter two techniques having been widely used for cancer prognosis. Nodal involvement and survival analyses in breast cancer are carried out for 100 women who were clinically diagnosed with breast disease in the form of carcinoma and benign conditions, and seven prognostic markers collected for each patient. For nodal involvement analysis, node positive and negative patients are predicted whereas survival analysis is carried out for two categories: whether a patient is alive or dead within 5 years of diagnosis. The results obtained show that the fuzzy method yields the highest predictive accuracy of 88% for both nodal involvement and survival analyses obtained from the subsets of [tumour grade, S-phase fraction, minimum (start) nuclear pleomorphism index] and [tumour histology type, DNA ploidy, S-phase fraction, G0G1/G2M ratio], respectively. We believe that this technique has produced more reliable prognostic factor models than those obtained using either the statistical or artificial neural networks-based methods.


Assuntos
Neoplasias da Mama/mortalidade , Neoplasias da Mama/patologia , Lógica Fuzzy , Redes Neurais de Computação , Análise de Sobrevida , Neoplasias da Mama/genética , Ciclo Celular/fisiologia , Feminino , Humanos , Linfonodos/patologia , Metástase Linfática , Ploidias , Prognóstico
16.
Melanoma Res ; 11(5): 491-4, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11595886

RESUMO

Amelanotic cutaneous melanoma (ACM) often defies clinical diagnosis because of the lack of pigmentation. In an attempt to find diagnostic clues, we retrospectively studied the clinical features of 15 thin (< 1 mm thick or Clark level I) ACM lesions. The clinical features of early ACMs are identified and illustrated to enable early diagnosis and cure of these lesions. The typical early lesion presents as an asymmetric macula, which may be uniformly pinkish or reddish or, more often, has faint light pigmentation (tan, brown or grey) at the periphery; it has borders that may be well- or ill-defined. In our study, these features suggested the correct clinical diagnosis in only a minority (40%) of cases. Nine cases in this series were also subjected to dermatoscopy. By this technique we identified, as constant feature, the presence of small red dots, evenly distributed or grouped on a whitish or pink-red background. Our results show the importance of dermatoscopy in the evaluation of equivocal pink or reddish lesions. Red dots seen with this technique can be an important sign for the diagnosis of thin ACM. Since this sign does not appear to be pathognomonic, the presence of an associated pigmentary network can be decisive in the differential diagnosis.


Assuntos
Dermatologia/métodos , Técnicas e Procedimentos Diagnósticos , Melanoma Amelanótico/diagnóstico , Melanoma Amelanótico/patologia , Neoplasias Cutâneas/diagnóstico , Neoplasias Cutâneas/patologia , Adulto , Idoso , Biópsia , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Pigmentação da Pele
17.
Phys Med Biol ; 45(5): 1243-54, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10843103

RESUMO

In an attempt to overcome the subjectiveness of clinical observation in the diagnosis of cutaneous melanoma, a computerized method is proposed. Reflectance images of 237 pigmented lesions (67 melanomas and 170 non-melanomas) were analysed using a telespectrophotometric technique. This device consists of a CCD camera with 17 interference filters. Images were acquired at selected wavelengths, from 420 to 1040 nm. Morphological and reflectance related parameters were extracted from the wavelength-dependent images of the lesions. The most significant features in the comparison between benign and malignant lesions were: lesion dimension (P < 10(-8) at 578 nm); mean value (P < 10(-7) at 940 nm) and standard deviation (P < 10(-4) at 904 nm) of lesion reflectance; lesion roundness (P < 10(-5) at 461 nm); and border irregularity (P < 10(-4) at 461 nm). Based on these parameters, a discriminant function between the two populations of lesions (naevi and melanomas) was obtained. By using the results of the analysis of the recruited lesions as 'training data', discriminant functions enabled the assignment of a score, or a 'risk probability', to each studied lesion. By imposing a sensitivity of 80% (a figure that mimics the diagnostic capability of an experienced clinician), entering or not entering the lesion dimension as input data in the discriminant analysis led to a specificity of 51% or 46% respectively. The high number of false-positive cases, which is a consequence of the selection criteria of the lesions, is, at present, the major limitation of the current technique. Nevertheless, our results suggest that an imaging-based computer-assisted device could be capable of discriminating malignant lesions mainly by evaluation of reflectance, especially in the infrared region, and shape properties. The dimension of a lesion should not be essential in the diagnosis of melanoma and, in our opinion, small melanomas should be recognized by a computer system as well as they are on clinical grounds.


Assuntos
Melanoma/diagnóstico , Neoplasias Cutâneas/diagnóstico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Fenômenos Biofísicos , Biofísica , Criança , Diagnóstico por Computador/estatística & dados numéricos , Análise Discriminante , Reações Falso-Positivas , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Nevo Pigmentado/diagnóstico , Curva ROC , Sensibilidade e Especificidade , Espectrofotometria
18.
Plant Physiol ; 123(1): 335-44, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10806250

RESUMO

Ascorbic acid is synthesized from galactono-gamma-lactone (GL) in plant tissues. An improved extraction procedure involving ammonium sulfate precipitation of membrane proteins from crude leaf homogenates yielded a simple, quick method for determining tissue activities of galactono-gamma-lactone dehydrogenase (GLDH). Total foliar ascorbate and GLDH activity decreased with leaf age. Subcellular fractionation experiments using marker enzymes demonstrated that 80% of the total GLDH activity was located on the inner mitochondrial membrane, and 20% in the microsomal fraction. Specific antibody raised against potato (Solanum tuberosum L.) tuber GLDH recognized a 56-kD polypeptide in extracts from the mitochondrial membranes but failed to detect the equivalent polypeptide in microsomes. We demonstrate that isolated intact mitochondria synthesize ascorbate in the presence of GL. GL stimulated mitochondrial electron transport rates. The respiration inhibitor antimycin A stimulated ascorbate biosynthesis, while cyanide inhibited both respiration and ascorbate production. GL-dependent oxygen uptake was observed in isolated intact mitochondria. This evidence suggests that GLDH delivers electrons to the mitochondrial electron transport chain between complexes III and IV.


Assuntos
Ácido Ascórbico/biossíntese , Lactonas/metabolismo , Mitocôndrias/metabolismo , Sequência de Aminoácidos , Transporte de Elétrons , Lactonas/química , Dados de Sequência Molecular , Solanum tuberosum
19.
Int J Cancer ; 86(2): 255-61, 2000 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-10738254

RESUMO

We studied a group of patients with or without individual or family history of melanoma for the occurrence of genetic alterations at microsatellite DNA sequences, usually referred to as microsatellite instability (MSI), and loss of heterozygosity (LOH). Microsatellite analysis of 3 markers located on chromosome 9p21-22 was performed for 88 melanocytic lesions, including 27 melanomas and 35 dysplastic and 26 common nevi, from 48 patients. Three additional markers, on 11q23, 17q21 and 5q22, were investigated in 16 melanomas. Overall, microsatellite alterations of the type usually considered low-level instability at 9p21-22 were observed in 22% of melanomas and 31% of dysplastic and 23% of common nevi. LOH at the same loci was found in 15% of melanomas and 8% of dysplastic nevi but never in common nevi. Cases with a positive family history of melanoma compared to those with a negative family history showed a higher microsatellite alteration frequency (43% vs. 20%), and the same was observed in melanoma compared to non-melanoma carriers (31% vs. 16%). Our results show that (i) MSI is common in all melanocytic lesions, though with differences in the group of patients which could have clinical relevance if confirmed, whereas LOH is restricted to melanomas and dysplastic nevi; (ii) various melanocytic lesions from the same patient represent clonally distinct tumors; (iii) the phenotype suggestive of DNA repair deficiency is influenced by a family or an individual history of melanoma; (iv) the microsatellite alteration frequency correlates with patient groups ordered according to increasing melanoma risk.


Assuntos
Melanoma/genética , Repetições de Microssatélites/genética , Nevo Pigmentado/genética , Cromossomos Humanos Par 11 , Cromossomos Humanos Par 17 , Cromossomos Humanos Par 5 , Cromossomos Humanos Par 9 , Reparo do DNA , Síndrome do Nevo Displásico/genética , Síndrome do Nevo Displásico/patologia , Humanos , Perda de Heterozigosidade , Nevo Pigmentado/patologia , Reação em Cadeia da Polimerase
20.
Neuropathol Appl Neurobiol ; 25(5): 408-16, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10564531

RESUMO

The INK4a-ARF locus encodes two unrelated proteins that both function in tumour suppression: p16INK4a and p19INK4d. Although p19INK4d expression has not been studied in central nervous system (CNS) tumours, it has been reported that p16INK4a inactivation is involved in the growth of glioblastomas. This observation has not been reported in relation to other CNS tumours. To understand further the role of p16INK4a and p19INK4d in neuroglial tumour growth, expression of both p16INK4a and p19INK4d mRNAs was studied by reverse transcription polymerase chain reaction RT-PCR in 59 neuroglial tumours, in which Ki67 labelling indices (LI) were also determined. P16INK4a mRNA was found in all pilocytic astrocytomas (7/7), in all grade II and III astrocytomas (7/7 and 4/4, respectively), in 4/12 glioblastomas, 8/8 oligodendrogliomas, 10/11 anaplastic oligodendrogliomas, 4/7 ependymomas and 3/3 anaplastic ependymomas but not in normal brain. In contrast, p19INK4d mRNA was detected in all tumours and control tissues. p16INK4a expression was associated with a low Ki67 LI in glioblastomas but not in other tumours. P16INK4a expression was not related to anaplasia in oligodendrogliomas and ependymomas. In tumours expressing p16INK4a, in situ hybridization showed a widespread expression of p16INK4a mRNA in tumour cells and in foci of microvascular proliferation. These results strongly support the concept that p16INK4a is involved in the regulation of proliferation in glioblastomas. Other cell cycle regulators which are yet unknown may also play a role in the control of oligodendrogliomas or ependymomas outgrowth. Further studies are required to evaluate the role of p19INK4d in neuroglial tumours.


Assuntos
Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Proteínas de Transporte/genética , Proteínas de Ciclo Celular , Inibidor p16 de Quinase Dependente de Ciclina/genética , Antígeno Ki-67/metabolismo , Neuroglia/patologia , RNA Mensageiro/metabolismo , Adolescente , Adulto , Idoso , Divisão Celular , Criança , Pré-Escolar , Inibidor de Quinase Dependente de Ciclina p19 , Feminino , Humanos , Imuno-Histoquímica , Hibridização In Situ , Lactente , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase Via Transcriptase Reversa
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