Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Int J Oral Maxillofac Surg ; 42(4): 464-9, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23395651

RESUMO

Fractures of the mandibular condyle are common and account for 25-35% of all mandibular fractures reported in the literature. Even with the development of a consensus on the preference for open reduction and internal fixation of these fractures, the clinician is still faced with a dilemma concerning the optimal approach to the ramus-condyle unit. Limited access and injury to the facial nerve are the most common problems. The most commonly used extraoral approaches are the submandibular, retromandibular and preauricular methods. In this study, we propose a modified cosmetic preauricular incision with a short end in the neck, to improve the transmasseteric anteroparotid (TMAP) approach previously described by Wilson et al. in 2005. We retrospectively analysed 13 patients treated in our department for mandibular condylar fractures. Post-operative complications, occlusal status, interincisal opening and joint tenderness were evaluated at 3 months after surgery. The wider skin incision described here provides a convenient approach for open reduction and rigid internal fixation, and good results were obtained. The follow-up ranged from 6 to 40 months.


Assuntos
Fixação Interna de Fraturas/métodos , Côndilo Mandibular/lesões , Fraturas Mandibulares/cirurgia , Músculo Masseter/cirurgia , Procedimentos Cirúrgicos Bucais/métodos , Adolescente , Adulto , Feminino , Humanos , Masculino , Côndilo Mandibular/cirurgia , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento
2.
Minerva Stomatol ; 54(7-8): 405-14, 2005.
Artigo em Inglês, Italiano | MEDLINE | ID: mdl-16210999

RESUMO

Head and neck squamocellular carcinoma (HNSCC) has now become the 6th most common cancer among men in the developed world and affects the oral cavity, salivary glands, larynx and pharynx. Tobacco chewing, alcohol consumption and last but not least, smoking seem to be the most important risk factors. In particular in non-drinkers, smoke increases the relative risk (RR) of developing HNSCC of the oral cavity and pharynx from 2 to 20 fold; especially in the oral cavity, the association between alcohol and smoke could have a multiplier effect. Cancer arises from damage to DNA of genes located at various points of the short (p) and long (q) arms of a number of chromosomes, caused by exposure to various carcinogens. Thus, the carcinogenic process requires continuous exposure to environmental carcinogens (i.e., longstanding history of smoking and drinking), an increased susceptibility to carcinogens (induced by xenobiotic metabolizing enzyme polymorphism) and an impaired DNA repair capacity (both inherited and acquired). Our purpose in this paper is to review advances in the understanding of the role of the European or Caucasian genetic aberrations that affect carcinogen metabolism and DNA repair genes in oral HNSCC development: we consider that those abnormalities will be useful in assessing individuals at risk.


Assuntos
Carcinógenos/metabolismo , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/metabolismo , Reparo do DNA , Neoplasias de Cabeça e Pescoço/genética , Neoplasias de Cabeça e Pescoço/metabolismo , Neoplasias Bucais/genética , Neoplasias Bucais/metabolismo , Humanos
3.
Bioinformatics ; 18 Suppl 1: S62-70, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12169532

RESUMO

MOTIVATION: Accurate prediction of protein contact maps is an important step in computational structural proteomics. Because contact maps provide a translation and rotation invariant topological representation of a protein, they can be used as a fundamental intermediary step in protein structure prediction. RESULTS: We develop a new set of flexible machine learning architectures for the prediction of contact maps, as well as other information processing and pattern recognition tasks. The architectures can be viewed as recurrent neural network implemantations of a class of Bayesian networks we call generalized input-output HMMs (GIOHMMs). For the specific case of contact maps, contextual information is propagated laterally through four hidden planes, one for each cardinal corner. We show that these architectures can be trained from examples and yield contact map predictors that outperform previously reported methods. While several extensions and improvements are in progress, the current version can accurately predict 60.5% of contacts at a distance cutoff of 8 A and 45% of distant contacts at 10 A, for proteins of length up to 300.


Assuntos
Algoritmos , Modelos Moleculares , Redes Neurais de Computação , Proteínas/química , Alinhamento de Sequência/métodos , Análise de Sequência de Proteína/métodos , Sequência de Aminoácidos , Inteligência Artificial , Sítios de Ligação , Retroalimentação , Cadeias de Markov , Modelos Estatísticos , Dados de Sequência Molecular , Ligação Proteica , Conformação Proteica , Dobramento de Proteína
4.
Prof Inferm ; 55(4): 210-7, 2002.
Artigo em Italiano | MEDLINE | ID: mdl-12599717

RESUMO

UNLABELLED: In the intensive care unit (ICU) of Mestre hospital (Italy) a research was carried out to analyse the possibility to improve nurses' lip-reading skills. METHODS: A specialized speech therapist organized a 20 hour training course for 34 health workers in ICU. RESULTS: The participants had a lip-reading test at the beginning and at the end of the course and six months later. The final test revealed that participants could recognize a greater number of typical words in ICU in comparison to the initial test. Yet, after 6 months the skill decreased to the level shown at the beginning of the course. On the other hand, the trend shows that some participants' skill did not decrease. Neither the starting level nor intermediate stage are conditioned by sex, age, profession, and experience. In order to measure clinic efficacy, the participants had another test to understand if improved lip-reading skill could influence the following variables: word comprehension, nurse attitude to communication toward non-speaking people, patient emotional status and nurse emotional status. The training course seems to have had good effects on nurses' attitudes towards their patients and on their communication. Yet, study results do not show if increased lip-reading skills have real positive effects on ICU communication and whether this method is better than usual communication methods (e.g. mimic or alphabetic board).


Assuntos
Cuidados Críticos , Educação em Enfermagem , Leitura Labial , Relações Enfermeiro-Paciente , Humanos , Projetos Piloto
5.
Minerva Stomatol ; 50(9-10): 331-6, 2001.
Artigo em Italiano | MEDLINE | ID: mdl-11723433

RESUMO

The adenomatoid odontogenic tumor is a benign bony lesion of the maxilla and mandible, it represents 3% of all odontogenic tumors, and is more frequent in females in their second decade of life. It affects mainly the maxilla associated with embedded teeth, often canines, but it also occurs in the mandible, especially in the anterior region. It originates from epithelial cells of the dental lamina complex system, but the histologic feature with gland-like structures explains its name and classification. Clinically silent, it is often discovered during radiological examinations as a well defined unilocular radiolucent image. The definitive diagnosis is obtained by histological examinations, which allow the differential diagnosis from other bony lesions. Treatment must include close examinations, such as axial and coronal CT scanning and eventually 3D reconstruction. Histological examination with a preoperative biopsy suggests a conservative surgical treatment consisting of a simple enucleation for the low incidence of recurrence. A clinical case is presented with peculiar features different from that reported in letterature.


Assuntos
Neoplasias Mandibulares/diagnóstico , Tumores Odontogênicos/diagnóstico , Feminino , Humanos , Pessoa de Meia-Idade
6.
Bioinformatics ; 17 Suppl 1: S234-42, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11473014

RESUMO

Knowing the number of residue contacts in a protein is crucial for deriving constraints useful in modeling protein folding, protein structure, and/or scoring remote homology searches. Here we use an ensemble of bi-directional recurrent neural network architectures and evolutionary information to improve the state-of-the-art in contact prediction using a large corpus of curated data. The ensemble is used to discriminate between two different states of residue contacts, characterized by a contact number higher or lower than the average value of the residue distribution. The ensemble achieves performances ranging from 70.1% to 73.1% depending on the radius adopted to discriminate contacts (6Ato 12A). These performances represent gains of 15% to 20% over the base line statistical predictors always assigning an aminoacid to the most numerous state, 3% to 7% better than any previous method. Combination of different radius predictors further improves the performance. SERVER: http://promoter.ics.uci.edu/BRNN-PRED/.


Assuntos
Biologia Computacional , Redes Neurais de Computação , Proteínas/química , Sequência de Aminoácidos , Bases de Dados de Proteínas , Estrutura Molecular
7.
Artigo em Inglês | MEDLINE | ID: mdl-10977063

RESUMO

Predicting the secondary structure (alpha-helices, beta-sheets, coils) of proteins is an important step towards understanding their three dimensional conformations. Unlike alpha-helices that are built up from one contiguous region of the polypeptide chain, beta-sheets are more complex resulting from a combination of two or more disjoint regions. The exact nature of these long distance interactions remains unclear. Here we introduce two neural-network based methods for the prediction of amino acid partners in parallel as well as anti-parallel beta-sheets. The neural architectures predict whether two residues located at the center of two distant windows are paired or not in a beta-sheet structure. Variations on these architecture, including also profiles and ensembles, are trained and tested via five-fold cross validation using a large corpus of curated data. Prediction on both coupled and non-coupled residues currently approaches 84% accuracy, better than any previously reported method.


Assuntos
Redes Neurais de Computação , Estrutura Secundária de Proteína , Proteínas/química , Proteínas/genética , Animais , Humanos , Valor Preditivo dos Testes , Dobramento de Proteína
8.
Minerva Stomatol ; 49(1-2): 13-20, 2000.
Artigo em Italiano | MEDLINE | ID: mdl-10932903

RESUMO

BACKGROUND: The authors' aim is to show, through a morphological analysis, how the use of a passive functional plate in hard acrylic resin can guide the growth of the maxillary segments in babies born with cleft lip and palate. METHODS: The authors have obtained, with a scanner gray scales, bidimensional monochromatic images of nine babies' dental casts with cleft lip and palate at birth and at the time of the first cheilo-rhinoplastic surgery. A graphic analysis on these images was made comparing the charts drawn by Bolter's points identified on the maxillary alveolar arch. RESULTS: The overlapping of the graphic analysis of the mean of values recorded at birth and after the application of the functional passive plate in hard acrylic resin shows how it is possible to promote the growth of maxillary alveolar arch with unilateral complete cleft. CONCLUSIONS: The authors believe that the presurgical orthopedic functional treatment can lay the bases for a symmetric and balanced skeletal growth of the cleft maxillary. This treatment will promote a better future occlusal relationship. It's also pointed out how this functional approach can favour plastic surgery in reducing cleft's size.


Assuntos
Fenda Labial/terapia , Fissura Palatina/terapia , Maxila/anatomia & histologia , Ortodontia Corretiva , Obturadores Palatinos , Fatores Etários , Fenda Labial/cirurgia , Fissura Palatina/cirurgia , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Maxila/crescimento & desenvolvimento , Cuidados Pré-Operatórios
9.
Bioinformatics ; 15(11): 937-46, 1999 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-10743560

RESUMO

MOTIVATION: Predicting the secondary structure of a protein (alpha-helix, beta-sheet, coil) is an important step towards elucidating its three-dimensional structure, as well as its function. Presently, the best predictors are based on machine learning approaches, in particular neural network architectures with a fixed, and relatively short, input window of amino acids, centered at the prediction site. Although a fixed small window avoids overfitting problems, it does not permit capturing variable long-rang information. RESULTS: We introduce a family of novel architectures which can learn to make predictions based on variable ranges of dependencies. These architectures extend recurrent neural networks, introducing non-causal bidirectional dynamics to capture both upstream and downstream information. The prediction algorithm is completed by the use of mixtures of estimators that leverage evolutionary information, expressed in terms of multiple alignments, both at the input and output levels. While our system currently achieves an overall performance close to 76% correct prediction--at least comparable to the best existing systems--the main emphasis here is on the development of new algorithmic ideas. AVAILABILITY: The executable program for predicting protein secondary structure is available from the authors free of charge. CONTACT: pfbaldi@ics.uci.edu, gpollast@ics.uci.edu, brunak@cbs.dtu.dk, paolo@dsi.unifi.it.


Assuntos
Algoritmos , Biologia Computacional/métodos , Modelos Genéticos , Redes Neurais de Computação , Estrutura Secundária de Proteína , Simulação por Computador , Estudos de Avaliação como Assunto , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Validação de Programas de Computador
10.
Minerva Stomatol ; 46(1-2): 27-38, 1997.
Artigo em Italiano | MEDLINE | ID: mdl-9173214

RESUMO

Pain, which is among the most prevalent symptoms experienced by cancer patients, must absolutely be treated. The most important biologic effects of this sort of pain plays on patients' psychosociality. This is in reference to the quality of pain, the amount of pain and to the character of the patients. Actually, pain only in appearance is presented as a symptom; it is usually a disease. Patient assessment, the use of anticancer therapies and systematically administered non-opioid and opioid analgesics are pivotal. Practical aspects of cancer pain treatment include both drug selection, method of analgesic administration: selection of the appropriate route, dose titration and an understanding of the management of side effects. Pain therapy includes another series of possibilities like the use of adjuvant analgesics, psychological therapies, physiatric techniques and invasive interventions such as the use of intraspinal drugs, neural blockade and neuroablative techniques. This kind of therapy must be employed at all times, whether the case may be resolved surgically or not. So we think that pain can be effectively treated. This study was carried out to obtain the correct therapeutic approach for facial cancer pain syndrome. The research was performed on seven women and thirteen men with a mean age of 58 years. All the patients' clinical appearances were standardized with care. Study participants included odontostomatologists and anesthesiologists with experience of controlling cancer pain. The sensation of pain was quantified by means of the Visual Analogue Scale (VAS) while their psychosocial ability was assessed with the Karnofsky Performance Scale (KPS). In this way the authors hoped to obtain a good quality of standardization. The study was performed for a period of two months. The conclusions are that Trans Epidermis Nervous Stimulation (TENS) offers positive results for variable periods and only in 60% of patients with a low level of pain. The use of antiphlogistic non-steroid drugs and of opioid drugs, with a particular management requested from the personal clinical status of each patient, result as being the most effective therapeutic resource. Such therapies must be employed, whether the case may be resolved surgically or not. Nevertheless it is necessary to realize that drugs or other therapies for cancer pain are independent and propaedeutic to each surgical approach. Finally, the use of opioids is addressed in the management of patients with pain that is refractory to other interventions. This approach can provide adequate relief to the vast majority of patients. We find the morphinomania risk in cancer pain patients is not scientifically wellfounded.


Assuntos
Analgésicos/classificação , Neoplasias Bucais/fisiopatologia , Dor/tratamento farmacológico , Adjuvantes Farmacêuticos/uso terapêutico , Corticosteroides/uso terapêutico , Adulto , Idoso , Analgésicos/uso terapêutico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Entorpecentes/uso terapêutico , Dor/etiologia , Dor Intratável/tratamento farmacológico , Dor Intratável/etiologia , Resultado do Tratamento
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...