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Search Results: 1 - 10 of 220648 matches for " Kowalski Luiz P. "
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Carcinoma mucoepidermóide de cabe?a e pesco?o: estudo clínico-patológico de 173 casos
Pires, Fábio R.;Alves, Fábio de A.;Almeida, Oslei P. de;Kowalski, Luiz P.;
Revista Brasileira de Otorrinolaringologia , 2002, DOI: 10.1590/S0034-72992002000500013
Abstract: introduction: mucoepidermoid carcinoma (mec) is the most common malignant salivary gland tumor, however few studies have been reported in brazilian populations. objective: to report clinical and pathologic data from 173 head and neck mec treated in the centro de tratamento e pesquisa hospital do cancer a. c. camargo in s?o paulo. study design: clinical randomized. material and method: from 1953 to 1997, 173 cases of mec were found in the files of the centro de tratamento e pesquisa hospital do cancer a. c. camargo. data were obtained from the patients' records and histological review of all cases. results: the mean age of the patients was 44 years and 93 (53,8%) were men; parotid glands were affected in 61 cases (35,2%) and intra-oral minor salivary glands in 75 (43,4%). tnm revealed 50,3% of the cases in stages i and ii, and histological grading revealed 45,2%, 18,5% and 36,3% low-grade, intermediate-grade and high-grade tumors, respectively. surgical treatment was employed in 80,3% of the cases, with neck dissection in 52 cases (30,1%), and radiotherapy in 73 (42,2%). local recurrence, regional and distant metastasis were found in 12,7%, 9,8% and 9,2% of the patients, respectively; 5-year and 10-year overall survival rates were 70% and 60%, respectively. conclusions: mec affected mainly the parotid gland and the palate of adults, without gender predilection. half of the cases were diagnosed in initial clinical stages and 64% of the tumors were low or intermediate-grade lesions. surgery was the treatment of choice and prognosis was good.
Carcinoma mucoepidermóide de cabe a e pesco o: estudo clínico-patológico de 173 casos
Pires Fábio R.,Alves Fábio de A.,Almeida Oslei P. de,Kowalski Luiz P.
Revista Brasileira de Otorrinolaringologia , 2002,
Abstract: Introdu o: Carcinoma mucoepidermóide (CME) é o tumor maligno mais comum de glandulas salivares, entretanto poucos estudos em popula es brasileiras têm sido relatados na literatura. Objetivo: Reportar os dados clínico-patológicos de 173 CME de cabe a e pesco o do Centro de Tratamento e Pesquisa Hospital do Cancer A. C. Camargo em S o Paulo. Forma de estudo: Clínico randomizado. Material e Método: Cento e setenta e três casos de CME tratados entre 1953 e 1997, obtidos dos arquivos do Centro de Tratamento e Pesquisa Hospital do Cancer A. C. Camargo foram utilizados no estudo. Os dados foram obtidos a partir dos prontuários e da revis o histológica de todos os casos. Resultados: A idade média dos pacientes foi de 44 anos e 93 (53,8%) eram homens. Parótida foi acometida em 61 casos (35,2%) e as glandulas salivares menores intra-orais em 75 (43,4%), TNM revelou 50,3% dos casos em estádios I e II, e a grada o histológica revelou 45,2%, 18,5% e 36,3% tumores de baixo grau, grau intermediário e alto grau de malignidade, respectivamente. Tratamento cirúrgico foi utilizado em 80,3% dos casos, complementado por esvaziamento cervical em 52 casos (30,1%) e radioterapia em 73 (42,2%). Recidiva local, recidiva regional e metástase a distancia foram encontradas em 12,7%, 9,8% e 9,2% dos pacientes, respectivamente, e a sobrevida global dos pacientes em 5 e 10 anos foi de 70% e 60%, respectivamente. Conclus es: A avalia o dos 173 casos de CME de cabe a e pesco o mostrou que estes tumores ocorreram preferencialmente na glandula parótida e no palato de indivíduos adultos, sem predile o por sexo. Metade dos casos encontravam-se em estádios clínicos iniciais e 64% dos tumores eram de grau baixo ou intermediário de malignidade. O tratamento de escolha foi cirúrgico e o prognóstico dos pacientes foi bom.
Efficiency of the coherent biexciton admixture mechanism for multiple exciton generation in InAs nanocrystals
P. Kowalski,P. Machnikowski
Physics , 2015,
Abstract: We study the coherent mixing between two-particle (single exciton) and four-particle (biexciton) states of a semiconductor nanocrystal resulting from the coulomb coupling between states with different numbers of electron-hole pairs. Using a simple model of the nanocrystal wave functions and an envelope function approach, we estimate the efficiency of the multiple exciton generation (MEG) process resulting from such coherent admixture mechanism, including all the relevant states in a very broad energy interval. We show that in a typical ensemble of nanocrystals with 3~nm average radius, the onset of the MEG process appears about 1~eV above the lower edge of the biexciton density of states and the efficiency of the process reaches 50\% for photon energies around 5~eV. The MEG onset shifts to lower energies and the efficiency increases as the radius grows. We point out that the energy dependence of the MEG efficiency differs considerably between ensembles with small and large inhomogeneity of nancrystal sizes.
Continuous time evolution from iterated maps and Carleman linearization
P. Gralewicz,K. Kowalski
Physics , 2000,
Abstract: Using the Carleman linearization technique the continuous iteration of a mapping is studied. Based on the detailed analysis of the Carleman embedding matrix the precise mathematical meaning is given to such notion. The ordinary differential equations referring to continuous iterations are identified and the discussion of the relationship between them and the corresponding iterated maps is performed. Keywords: iterated systems, functional eigenequation
Functional microarray analysis suggests repressed cell-cell signaling and cell survival-related modules inhibit progression of head and neck squamous cell carcinoma
Anna EL Coló, Ana CQ Simoes, André L Carvalho, Camila M Melo, Lucas Fahham, Luiz P Kowalski, Fernando A Soares, Eduardo J Neves, Luiz FL Reis, Alex F Carvalho
BMC Medical Genomics , 2011, DOI: 10.1186/1755-8794-4-33
Abstract: Tumor samples were obtained from untreated HNSCC patients undergoing surgery. Patients were classified according to pathologic lymph node status (positive or negative) or tumor recurrence (recurrent or non-recurrent tumor) after treatment (surgery with neck dissection followed by radiotherapy). Using microarray gene expression, we screened tumor samples according to modules comprised by genes in the same pathway or functional category.The most frequent alterations were the repression of modules in negative lymph node (N0) and in non-recurrent tumors rather than induction of modules in N+ or in recurrent tumors. N0 tumors showed repression of modules that contain cell survival genes and in non-recurrent tumors cell-cell signaling and extracellular region modules were repressed.The repression of modules that contain cell survival genes in N0 tumors reinforces the important role that apoptosis plays in the regulation of metastasis. In addition, because tumor samples used here were not microdissected, tumor gene expression data are represented together with the stroma, which may reveal signaling between the microenvironment and tumor cells. For instance, in non-recurrent tumors, extracellular region module was repressed, indicating that the stroma and tumor cells may have fewer interactions, which disable metastasis development. Finally, the genes highlighted in our analysis can be implicated in more than one pathway or characteristic, suggesting that therapeutic approaches to prevent tumor progression should target more than one gene or pathway, specially apoptosis and interactions between tumor cells and the stroma.Head and neck squamous cell carcinomas (HNSCC) are the seventh most common solid malignancy in the United States, accounting for more than 47,000 new cancer cases per year [1]. Surgery of patients clinically diagnosed with lymph node metastasis (N+) usually involves neck dissection, which can cause disfigurement, functional impairment, and pain. However, af
Pilocarpina no tratamento de xerostomia em pacientes submetidos à iodoterapia: estudo piloto
Almeida, Juliana Pereira;Kowalski, Luiz Paulo;
Brazilian Journal of Otorhinolaryngology , 2010, DOI: 10.1590/S1808-86942010000500021
Abstract: xerostomia complaint is very commonly associated to radioactive iodine therapy. alternatives to treat this morbidity can offer better quality of life to patients with thyroid cancer submitted to adjuvant iodine therapy. aim: to report on the experience with pilocarpine on the treatment of xerostomia in thyroid cancer patients submitted to adjuvant radioactive iodine therapy (rit). materials and methods: the five patients who met the inclusion criteria received 5mg of pilocarpine, 3 tid for one week. side effects of the drug and subjective response to xerostomia complaints after treatment were evaluated. design: it is a prospective, non-randomized study. results: sudoresis was the most frequent side effect of pilocarpine use, followed by fatigue and headache. two patients reported relief of xerostomia using pilocarpine, but only one patient was able to tolerate the side effects. conclusions: pilocarpine seems to relieve xerostomia complaints in thyroid cancer patients because it is able to stimulate salivary flow, but the observed side effects made the patients refuse long-term therapy continuation.
Who are the low-risk patients that could benefit from watch-and-wait regarding the neck?
Kohler, Hugo Fontan;Kowalski, Luiz Paulo;
Sao Paulo Medical Journal , 2011, DOI: 10.1590/S1516-31802011000500002
Abstract: context and objective: the management of clinically negative neck is controversial, with an ongoing debate on the indication criteria and prognostic impact of different types of therapy. the aim here was to compare the results from neck dissection and watch-and-wait, among oral cancer patients who, clinically, did not show any evidence of neck metastasis. design and setting: retrospective analysis in a tertiary cancer center hospital. methods: patients with epidermoid oral carcinoma were assessed. the inclusion criteria were: primary tumor restricted to the oral/oropharyngeal cavity, no previous treatment, surgical treatment as the first option, clinical/radiological stage n0 and no distant metastasis. results: two hundred and sixty-two patients were analyzed. the length of follow-up ranged from four to 369.6 months and, at the end, 118 patients were alive, 53 had died due to cancer, 84 had died from other causes and 7 had died after the operation. among the patients who underwent neck dissection, lymphatic vascular embolization (p = 0.009) and tumor thickness (p = 0.002) were significant for regional recurrence, while for the watch-and-wait group, only tumor thickness was significant (p = 0.018). through recursive partitioning, the patients without adverse prognostic factors and tumor thickness < 2 mm presented compatible results in the two groups. conclusion: elective neck dissection seems to be the best treatment option. patients who are eligible for watch-and-wait constitute a small group that, ideally, is categorized according to the postoperative pathological findings
O impacto do nível da metástase cervical no prognóstico dos pacientes com carcinoma epidermoide de cavidade oral Prognostic impact of the level of neck metastasis in oral cancer patients
Hugo Fontan K?hler,Luiz Paulo Kowalski
Brazilian Journal of Otorhinolaryngology , 2012, DOI: 10.5935/1808-8694.20120027
Abstract: Em pacientes com carcinoma epidermoide oral, classifica-se o pesco o pelo número, tamanho e lateralidade das metastáses. OBJETIVO: Avaliar fatores de risco para metástase em nível IV/V e seu impacto no prognóstico do carcinoma epidermoide oral. MéTODO: Estudo retrospectivo. Critérios de inclus o foram: diagnóstico de CEC, sítio primário em andar inferior da boca sem extens o para sítios extraorais, ausência de tratamento prévio, realiza o de EC e presen a de metástases linfáticas. Por regress o logística, definiram-se fatores de risco e por análise de sobrevivência, fatores prognósticos de recorrência. Análise classificatória realizada por particionamento recursivo. RESULTADOS: Foram incluídos 307 pacientes. Em regress o logística univariada, o estágio pN, emboliza o vascular, e múltiplos linfonodos comprometidos foram fatores de risco para metástases em nível IV/V. Emboliza o vascular e múltiplos linfonodos comprometidos permaneceram significativos em análise multivariada. A análise de sobrevivência demonstrou os estágios pT e pN, infiltra o perineural, emboliza o vascular, número de linfonodos metastáticos, raz o linfonodal e metástases em níveis IV/V como significativos. Na análise multivariada, PT, pN, emboliza o vascular linfática e metástases em níveis IV/V permaneceram significativas. Na análise classificatória, o estágio pN n o foi significativo quando há metástases em níveis IV/V. CONCLUS O: A ocorrência de metástases em níveis IV/V foi significativa para sobrevivência doen a-específica. Neck staging in oral cancer depends on the number of compromised nodes, their size and side of occurrence. OBJECTIVE: This paper aims to evaluate risk factors for metastatic nodes in levels IV/V and their prognostic impact on patients with oral carcinoma. METHOD: Retrospective study. Inclusion criteria: pathologist's diagnosis of squamous cell carcinoma, primary tumor in the lower oral cavity, no extension into extraoral sites, no previous treatment, synchronous neck dissection and presence of metastatic nodes. Risk factors for metastasis were evaluated through logistic regression and disease-specific survival and recurrence by survival analysis. Classificatory analysis was performed through recursive partitioning. RESULTS: 307 patients met the inclusion criteria. Univariate logistic regression identified pN stage, vascular invasion, and multiple metastatic nodes as risk factors for metastases in levels IV/V. Multivariate analysis found vascular invasion and multiple metastatic nodes were significant. Survival analysis revealed pT, pN, neural infiltration
Oral health, hygiene practices and oral cancer
Marques,Luzia A; Eluf-Neto,José; Figueiredo,Rejane A O; Góis-Filho,José F de; Kowalski,Luiz P; Carvalho,Marcos B de; Abrah?o,Márcio; Wünsch-Filho,Victor;
Revista de Saúde Pública , 2008, DOI: 10.1590/S0034-89102008000300012
Abstract: objective: to assess the association between oral health and hygiene practices and oral cancer. methods: hospital-based case-control study in the metropolitan area of s?o paulo, southeastern brazil, from 1998 to 2002. a total 309 patients with squamous cell carcinoma of the mouth and the pharynx and 468 controls matched by sex and age were included in the study. cases were recruited in seven reference hospitals and controls were selected in five out of the seven participating hospitals. detailed information on smoking, alcohol consumption, schooling, oral health status and hygiene practices were obtained through interviews. odds ratios (or) and 95% confidence intervals (95% ci), adjusted by sex, age, schooling, smoking, alcohol consumption as well as the variables oral health status and hygiene practices were estimated using unconditional logistic regression analyses. results: the use of complete dental prosthesis was not associated with oral cancer but regular gum bleeding showed a strong association (or 3.1; 95% ci 1.2-7.9). those who never attended a dental visit were more likely to have oral cancer (or 2.5; 95% ci 1.3-4.8). daily mouthwash use showed a stronger association to pharynx (or 4.7; 95% ci 1.8-12.5) than mouth cancer (or 3.2; 95% ci 1.6-6.3). conclusions: gum bleeding, no dental care, and daily mouthwash use were factors associated with oral cancer regardless of tobacco and alcohol consumption.
Salvage for cervical recurrences of head and neck cancer with dissection and interstitial high dose rate brachytherapy
Antonio Pellizzon, Jo?o Salvajoli, Luiz Kowalski, Andre Carvalho
Radiation Oncology , 2006, DOI: 10.1186/1748-717x-1-27
Abstract: The best approach for advanced head and neck cancer (HNC) is the combined modality using surgery, adjuvant radiotherapy with or without chemotherapy. For patients who refuse surgery, the superiority of radiation (RT) concurrent with chemotherapy (CHT) in local and regional tumor control has been established in several randomized studies and meta-analyses [1,2], but even for multimodality treated patients the recurrence rates above the clavicles occur in up to 20% of patients [3,4].Salvage therapy in HNC is still a controversy issue and the best combination approach is still to be defined. It seems that maximum debulking surgery combined to a primary or a second new course of RT can lead to a better local control (LC). Conversely, a new course of external beam radiotherapy (EBRT) for recurrent disease is always a problem and of limited feasibility because of the difficulty to spare adjacent normal tissues, resulting in undesirable late effects on the salivary glands, mandible, and muscles of mastication. In these cases the use of intra-operative interstitial implantation is an option, as it is ideally suited to deliver a high dose to a limited volume, thus minimizing sequelae and improving LC [5]. I-HDR can also increase total biological effective dose administered when compared to a second course of EBRT, the overall time is decreased and it is also a very conformal way of treatment, allowing protection of normal surrounding structures [6].In 1996 we started an institutional treatment policy of post-operative I-HDR for recurrent cervical carcinomas, with tumor control on the site of the primary, to take advantage of shortening the overall treatment time and conformability of the procedure.All patients admitted for treatment at the Radiation Oncology and Head and Neck Surgery Departments, Hospital do Cancer A.C. Camargo, S?o Paulo, Brazil, from October 1994 to June 2004, were retrospectively selected. The criteria for including patients in the study were: recurrent c
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