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1.
BJOG ; 119(7): 800-9, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22571746

RESUMO

OBJECTIVE: To assess the efficacy and morbidity and mortality of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) in recurrent epithelial ovarian cancer (EOC). DESIGN: A retrospective study conducted using information extracted from a multi-institutional prospective database on peritoneal surface malignancies (PSMs). Setting Four Italian centres specializing in locoregional treatment of PSM. POPULATION: Patients with recurrent EOC. METHODS: Fifty-six patients underwent 57 combined procedures. CRS was performed using peritonectomy procedures and HIPEC using the closed-abdomen technique with cisplatin and doxorubicin or cisplatin and mitomycin-C. MAIN OUTCOME MEASURES: Overall survival (OS), progression-free survival (PFS), morbidity and mortality rates. RESULTS: The median age of the patients was 55.2 years (range 30-75 years). The median peritoneal cancer index was 15.2 (range 4-30). Forty-seven patients had microscopic residual disease (completeness of cytoreduction, CC-0), seven had residual disease ≤2.5 mm (CC-1) and one had residual disease >2.5 mm (CC>2). Major complications occurred in 15 patients (26.3%), and procedure-related mortality occurred in three patients (5.3%). The median follow-up time was 23.1 months. The median OS and PFS were 25.7 (95% CI 20.3-31.0) and 10.8 (95% CI 5.4-16.2) months, respectively. The 5-year OS and PFS were 23% and 7%, respectively. Independent prognostic factors affecting OS according to the multivariate analysis were Eastern Cooperative Oncology Group performance status, preoperative serum albumin, and completeness of cytoreduction. CONCLUSIONS: Patients with recurrent EOC treated with CRS and HIPEC showed promising results in terms of outcome. The combined treatment strategy could benefit subsets of patients wider than that defined for conventional secondary debulking surgery without HIPEC. These data warrant further evaluation in randomised clinical trials.


Assuntos
Antineoplásicos/uso terapêutico , Hipertermia Induzida , Recidiva Local de Neoplasia/terapia , Neoplasias Epiteliais e Glandulares/terapia , Neoplasias Ovarianas/terapia , Neoplasias Peritoneais/terapia , Peritônio/cirurgia , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica , Carcinoma Epitelial do Ovário , Cisplatino/uso terapêutico , Terapia Combinada , Doxorrubicina/uso terapêutico , Esquema de Medicação , Feminino , Seguimentos , Humanos , Infusões Parenterais , Pessoa de Meia-Idade , Mitomicina/uso terapêutico , Análise Multivariada , Recidiva Local de Neoplasia/mortalidade , Neoplasias Epiteliais e Glandulares/mortalidade , Neoplasias Epiteliais e Glandulares/patologia , Neoplasias Ovarianas/mortalidade , Neoplasias Ovarianas/patologia , Neoplasias Peritoneais/mortalidade , Neoplasias Peritoneais/secundário , Estudos Retrospectivos , Análise de Sobrevida , Resultado do Tratamento
2.
Int Arch Allergy Immunol ; 154(3): 195-206, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-20861641

RESUMO

BACKGROUND: Ascaris lumbricoides induces a Th2 response and specific IgE synthesis in humans. This confers antiparasite immunity but could modify the natural history of allergic diseases in the tropics, justifying the study of its allergenic composition. We analyzed the allergenic properties of Ascaris tropomyosin and the frequency of sensitization in subjects exposed to the parasite. METHODS: cDNA was obtained by reverse transcription PCR, cloned into pQE30-UA and purified as a 6× His-tagged protein. Equivalence with its natural counterpart was analyzed by cross-inhibition and liquid chromatography-tandem mass spectrometry. Specific IgE was measured by ELISA in 175 asthmatics and 170 nonasthmatics naturally exposed to the parasite and sensitized to the Ascaris extract. RESULTS: The cDNA encoded 287 residues with high sequence identity with other invertebrate tropomyosins. The 40-kDa protein was recognized by human serum and affinity-purified anti-rBlo t 10 IgE. Specific IgE to tropomyosin could represent approximately 50% of the total IgE response to the extract. Ascaris tropomyosin induced wheal and flare in skin prick tests and histamine release from basophils. Although the prevalence of IgE to Ascaris tropomyosin was higher in asthmatic patients, logistic regression analysis suggested that this result was biased by sensitization to mites. CONCLUSIONS: A. lumbricoides tropomyosin (Asc l 3) is a new allergen that binds specific IgE, induces mediator release from effector cells and is cross-reactive to mite tropomyosins. IgE reactivity to this allergen is very frequent in both asthmatic and normal subjects sensitized to Ascaris extract. The potential role of Ascaris tropomyosin in asthma pathogenesis in tropical regions should be further investigated.


Assuntos
Alérgenos/imunologia , Ascaris lumbricoides/imunologia , Asma/imunologia , Imunoglobulina E/sangue , Tropomiosina/imunologia , Adolescente , Adulto , Alérgenos/genética , Sequência de Aminoácidos , Animais , Ascaris lumbricoides/metabolismo , Criança , Colômbia , Reações Cruzadas , Feminino , Humanos , Hipersensibilidade/imunologia , Imunoglobulina E/imunologia , Masculino , Pessoa de Meia-Idade , Ácaros/imunologia , Ácaros/metabolismo , Dados de Sequência Molecular , Análise de Sequência de DNA , Testes Cutâneos , Clima Tropical , Tropomiosina/genética , Adulto Jovem
3.
Acta Trop ; 103(3): 231-41, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17698018

RESUMO

Asthma and other respiratory diseases have increased in the last years among Venezuelan children from helminthic endemic areas where the infection by Ascaris lumbricoides has been associated to bronchial airway inflammation in parasitized individuals. The aim of this work was to investigate the possible associations between the development of bronchial hyper reactivity and the immune response against A. lumbricoides in urban and rural children. We evaluated 470 school children from rural and urban communities. Pulmonary function tests were performed and >or=20% PC(20) changes were considered as a positive diagnostic of bronchial hyper reactivity. The prevalence and intensity of A. lumbricoides infection was determined by faecal examination. Specific serum IgE levels using a modified ELISA and skin prick tests against A. lumbricoides and the common allergen Dermatophagoides pteronyssinus were done. The number of circulating lymphocyte sub populations was determined by flow cytometry analysis. In rural children, bronchial hyper reactivity was associated with increased specific levels of anti-A. lumbricoides IgE (p<0.0001) and skin test positivity for A. lumbricoides (p<0.0001). The percentage of FEV1 predictive values correlated inversely (p<0.0001) with anti-A. lumbricoides IgE levels. Elevated numbers of circulating CD3+CD4+ and CD20+CD23+ cells were found in rural children with bronchial hyper reactivity compared to their asymptomatic counterparts. They correlated positively with anti-A. lumbricoides IgE levels (p<0.005 and <0.0001, respectively). In contrast, in urban children, bronchial hyper reactivity was associated with elevated anti-D. pteronyssinus IgE levels (p=0. 0089), skin hyper reactivity towards this aero allergen (p=0.003) and to an increase in the number of CD3+CD8+ (p<0.0001). Our results suggest that the IgE response against A. lumbricoides infection may be involved in the development of bronchial hyper reactivity among rural children from endemic areas and also that improved hygienic conditions in the urban environment is associated with increased responses to airborne allergens.


Assuntos
Ascaríase/epidemiologia , Ascaríase/imunologia , Ascaris lumbricoides , Hiper-Reatividade Brônquica/parasitologia , Doenças Endêmicas , Animais , Ascaríase/complicações , Subpopulações de Linfócitos B , Hiper-Reatividade Brônquica/diagnóstico , Criança , Meio Ambiente , Feminino , Humanos , Hipersensibilidade/diagnóstico , Imunoglobulina E/sangue , Contagem de Linfócitos , Masculino , Prevalência , Testes de Função Respiratória , Dermatopatias/complicações , Dermatopatias/diagnóstico , Testes Cutâneos , Subpopulações de Linfócitos T , Venezuela/epidemiologia
4.
Int Surg ; 90(3 Suppl): S21-3, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16463943

RESUMO

Using mesh or a synthetic prosthesis during tension-free inguinal hernia repair has been shown to be safe and effective. We compared the final outcome in treating inguinal hernia in 45 patients using three different prosthetic materials: 15 patients underwent tension-free inguinal hernia repair using Prolene (polypropylene) mesh, 15 using Vypro (polyglactin and polypropylene) mesh, and 15 with Surgisis-a new bioactive material derived from porcine small intestinal submucosa. The aim of this study was to evaluate the safety and efficacy of tension-free inguinal repair using Surgisis, comparing it with conventional prosthetic materials. From January 2003 to December 2003, 45 male patients underwent Lichtenstein inguinal hernia repair. Median follow-up was 12 months, with a range of 1-16 months. Each patient underwent ultrasound evaluation of the inguinal region 1 month after surgery. All the procedures were completed under local anesthesia. There were no intraoperative complications, and all patients were discharged home the same day of surgery. No recurrent hernias and wound infections were observed in our post-operative follow-up period. Postoperative pain (visual analog score) and discomfort were lower in patients with Surgisis mesh. There was no statistically significant difference between the groups in terms of overall early and late complications; however, there was a tendency toward a higher incidence of pain and discomfort in Vypro and Prolene group. The median time to full recovery was significantly shorter in the Surgisis group. Surgisis mesh seems to be a promising new prosthetic material for hernia repair. Long-term follow-up is necessary to confirm these preliminary results.


Assuntos
Hérnia Inguinal/cirurgia , Telas Cirúrgicas , Adulto , Idoso , Animais , Distribuição de Qui-Quadrado , Humanos , Mucosa Intestinal , Masculino , Pessoa de Meia-Idade , Medição da Dor , Dor Pós-Operatória/epidemiologia , Poliglactina 910 , Polipropilenos , Suínos , Resultado do Tratamento
5.
J Steroid Biochem Mol Biol ; 87(2-3): 111-22, 2003 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-14672731

RESUMO

The specific pharmacological profile of the 19-norprogestin nomegestrol acetate (NOMAC) is, at least in part, defined by its pattern of binding affinities to the different steroid hormone receptors. In the present study, its affinity to the progesterone receptor (PgR), the androgen receptor (AR) and the estrogen receptor (ER) was re-evaluated and compared to those obtained for progesterone (P) and several progestins. The characteristics of binding to the PgR in rat uterus were determined and Ki were found to be roughly similar with 22.8 and 34.3 nM for NOMAC and P, respectively. The binding characteristics of 3H-NOMAC were also determined and compared to that of 3H-ORG2058 with Kd of 5 and 0.6 nM, respectively for rat uterus and 4 and 3 nM, respectively for human T47-D cells. Structure-affinity and -activity relationships were studied on a variety of compounds related to NOMAC in order to assess its specificity as a progestin. The effects of NOMAC on the binding of androgen to the AR were investigated, using rat ventral prostate as target model. Contrary to what was observed for MPA, the RBA of NOMAC was found to decline with time, showing anti-androgenic rather than androgenic potential, a result that was confirmed in vivo. Regarding the ER, since none of the progestins were able to compete with estrogen for binding in rat uterus as well as in Ishikawa cells, the induction of alkaline phosphatase activity (APase) was used as an estrogen-specific response. It confirmed the intrinsic estrogenicity of progestins derived from 19-nor-testosterone (19NT), norethisterone acetate (NETA), levonorgestrel (LNG) or norgestimate (NGM) and others. In contrast, all P and 19-norP derivatives remained inactive. Finally, to complete this overview of NOMAC at the sex steroid receptor levels, the lack of estrogenic or estrogenic-like activity was checked out in different in vitro models. Data from this study have demonstrated that NOMAC is a progestin that has greater steroid receptor selectivity compared to MPA or some other synthetic progestins. It may provide a better pharmacological profile than those progestins currently in use in HRT and OC.


Assuntos
Estrogênios/farmacologia , Megestrol/metabolismo , Megestrol/farmacologia , Neoplasias Hormônio-Dependentes/metabolismo , Norpregnadienos/metabolismo , Norpregnadienos/farmacologia , Receptores de Esteroides/metabolismo , Animais , Linhagem Celular Tumoral , Estradiol/farmacologia , Feminino , Humanos , Masculino , Megestrol/química , Norpregnadienos/química , Progestinas/metabolismo , Progestinas/farmacologia , Relação Estrutura-Atividade
6.
Ann N Y Acad Sci ; 547: 255-67, 1988.
Artigo em Inglês | MEDLINE | ID: mdl-3239889

RESUMO

Chronic administration of bombesin in the adult rat affects cell growth and enzyme activities in the pancreas. It also induces hyperplasia of the fundic mucosa, increases antral gastrin content, and stimulates gastrin cell proliferation in the antral mucosa. These effects could be explained by the release of hormones such as gastrin and CCK, whose trophic roles on the digestive tract are well proven. Some arguments raise the possibility that bombesin may also act directly on these organs (i.e., the presence of specific receptors for bombesin, pancreatic changes induced by bombesin and not blocked by a potent, specific CCK receptor antagonist). It may well be that both mechanisms exist simultaneously. In addition, bombesin has a growth-promoting effect on the gastric mucosa and pancreas of suckling rats when administered either subcutaneously or orogastrically. Keeping in mind that the maternal milk contains a bombesin-like immunoreactant peptide, we consider that the latter finding raises questions about the possible physiological role of such a peptide in the regulation of the postnatal development of the gastrointestinal tract.


Assuntos
Bombesina/farmacologia , Mucosa Gástrica/citologia , Intestino Grosso/citologia , Intestino Delgado/citologia , Pâncreas/citologia , Estômago/citologia , Animais , Divisão Celular/efeitos dos fármacos , Feminino , Mucosa Gástrica/efeitos dos fármacos , Intestino Grosso/efeitos dos fármacos , Intestino Delgado/efeitos dos fármacos , Índice Mitótico/efeitos dos fármacos , Pâncreas/efeitos dos fármacos , Ratos , Ratos Endogâmicos , Estômago/efeitos dos fármacos
7.
Regul Pept ; 20(1): 53-64, 1988 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-3258430

RESUMO

The effect of orogastrically given epidermal growth factor (EGF) on the on the development of the digestive system was examined in suckling rats. In particular, DNA synthesis in progenitor cells of the fundic, antral and ileal mucosae and of the exocrine pancreas was analyzed through tritiated thymidine injection and histoautoradiographic study. EGF (10 or 100 micrograms/kg, 3 times daily) was instilled in pups between the 11th and the 13th day of life. Controls received distilled water in a similar manner. All rats were killed 14th after the last orogastric instillation and 45 min after one pulse injection of tritiated thymidine. The highest dose of EGF increased the antral mucosal height (P less than 0.005), the mean number of epithelial cells per crypt column in ileal mucosa, as well as the cell labeling indices of fundic, antral, ileal mucosae and of pancreatic acinar tissue (P less than 0.001) as compared with controls. The lowest dose of EGF increased the cell labeling indices of antral and ileal mucosae and of the exocrine pancreas (P less than 0.001) but did not modify that of fundic mucosa as compared with controls. It is concluded that (a) orally given EGF stimulates cell proliferation in the digestive system of suckling rats, (b) antral mucosa is more sensitive to EGF than fundic mucosa, (c) it is likely that EGF is absorbed and acts systemically on the pancreas. It remains to be determined whether EGF acts systemically or by activation of luminal receptors, on fundic, antral and ileal mucosae.


Assuntos
Replicação do DNA/efeitos dos fármacos , Fator de Crescimento Epidérmico/farmacologia , Mucosa Gástrica/metabolismo , Mucosa Intestinal/metabolismo , Pâncreas/metabolismo , Administração Oral , Animais , Divisão Celular/efeitos dos fármacos , Fator de Crescimento Epidérmico/administração & dosagem , Fundo Gástrico/metabolismo , Mucosa Gástrica/citologia , Mucosa Gástrica/efeitos dos fármacos , Mucosa Intestinal/citologia , Mucosa Intestinal/efeitos dos fármacos , Pâncreas/citologia , Pâncreas/efeitos dos fármacos , Antro Pilórico/metabolismo , Ratos , Ratos Endogâmicos
8.
Regul Pept ; 27(1): 87-96, 1990 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-2408114

RESUMO

The present work investigated whether orally administered bombesin influences cell proliferation in the endocrine pancreatic islets of rats during the suckling period and after weaning. Four series of pups were given bombesin diluted in milk (20 micrograms/kg, 3 times daily) or milk alone for 5 days during either the first, second, third or fourth postnatal week of life. Oral administration was used because bombesin-like peptides have been identified in the breast milk of mammals. 45 min before death, animals were given a single [3H]thymidine pulse injection. Tissue sections were processed for radioautography; DNA labeling and mitotic indices were estimated after counting at least 1000 endocrine cells per rat pancreas. In control rats, the labeling and mitotic indices in pancreatic islets dropped regularly from the first week to the fourth week of life (3.6% +/- 0.2% versus 1.9% +/- 0.1% and 0.46% +/- 0.09% versus 0.08% +/- 0.02%, respectively). Orogastric bombesin administration significantly increased the DNA labeling and mitotic indices at the end of the first week (+20% and +62%, respectively) and second week of life (+37.5% and +49%, respectively) (P less than 0.05 to P less than 0.005), but did not modify these parameters for the third and subsequent weeks of life. Therefore, this study provides evidence that bombesin stimulates DNA synthesis and cell division in pancreatic endocrine cells during the developmental period.


Assuntos
Animais Recém-Nascidos , Bombesina/farmacologia , Ilhotas Pancreáticas/efeitos dos fármacos , Animais , Autorradiografia , Bombesina/genética , Divisão Celular/efeitos dos fármacos , DNA/biossíntese , Feminino , Ilhotas Pancreáticas/citologia , Ilhotas Pancreáticas/crescimento & desenvolvimento , Tamanho do Órgão , Gravidez , Ratos , Ratos Endogâmicos , Desmame
9.
Surg Endosc ; 15(10): 1227, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11727110

RESUMO

Calcifying fibrous pseudotumor (CFPT) is a recently described peculiar lesion characterized by the presence of abundant hyalinized collagen with psammomatous or dystrophic calcifications and a lymphoplasmacytic infiltrate. Initially, a few cases of CFPT were observed in the subcutaneous and deep soft tissues, especially at the level of the extremities, trunk, scrotum, groin, neck, and axilla; more recently, several cases have been reported in the pleura. We present a case of CFPT of the gastric wall. To our knowledge, this is the first such case to be described. A previously healthy 49-year-old woman presented with a 5-month history of epigastric pain after eating, early satiety, and weight loss. Gastroscopy revealed a polypoid lesion covered by normal mucosa along the great curvature of the gastric body. The patient was submitted to surgical treatment consisting of laparoscopic wedge resection of the gastric body. Histologic examination of the specimen disclosed CFPT affecting the wall of the gastrointestinal tract. The postoperative course was uneventful, and the patient was discharged from the hospital 5 days after surgery. The patient was free of disease 6 months after excision. Herein we discuss the clinicopathological features and surgical treatment of this most unusual case.


Assuntos
Calcinose/cirurgia , Gastropatias/cirurgia , Calcinose/patologia , Feminino , Fibrose , Humanos , Laparoscopia , Pessoa de Meia-Idade , Gastropatias/patologia
10.
J Cardiovasc Surg (Torino) ; 25(5): 437-9, 1984.
Artigo em Inglês | MEDLINE | ID: mdl-6501401

RESUMO

The authors report their incidence of infection after vascular surgery (7 infections in 1,687 operations = 0.4%). They did not find any infections after surgery of the aorto-iliac-femoral tract (768 operations). The authors ascribe these good results to not using alloplastic grafts below the inguinal ligament.


Assuntos
Desinfecção/métodos , Esterilização/métodos , Infecção da Ferida Cirúrgica/prevenção & controle , Procedimentos Cirúrgicos Vasculares , Amoxicilina/uso terapêutico , Ampicilina/uso terapêutico , Aorta Abdominal/cirurgia , Prótese Vascular , Artéria Femoral/cirurgia , Humanos , Artéria Ilíaca/cirurgia , Artéria Poplítea/cirurgia , Fatores de Tempo
11.
Minerva Chir ; 32(21): 1337-42, 1977 Nov 15.
Artigo em Italiano | MEDLINE | ID: mdl-600423

RESUMO

A case if ileorectal internal fistula during the course of regional ileitis is described. The clinical course and main forms of surgical managent are illustrated. The clinical, morphological and experimental pathological data indicated that this case should be classed as example of delayed hypersensitivity.


Assuntos
Doença de Crohn/complicações , Íleo , Fístula Intestinal/etiologia , Fístula Retal/etiologia , Feminino , Humanos , Fístula Intestinal/cirurgia , Pessoa de Meia-Idade , Fístula Retal/cirurgia
12.
G Chir ; 10(12): 709-12, 1989 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-2518412

RESUMO

A series of 110 patients out of 2,200, who had undergone Billroth II partial gastrectomy for benign lesions, between 1945 and 1980, was reviewed in order to perform clinical, biochemical and endoscopical examinations. In this group 9 patients (8.18%) showed gastric stump cancer and in 4 (3.63%) esophageal cancer was detected. The average time interval between previous operation and carcinoma diagnosis was of 28 years and 6 months. Eight patients out of 9 were males aging from 47 to 82, while the only woman was 65 (overall average: 63). The stump cancer presents at the same age and gives the same symptoms as primitive gastric carcinoma, but with worse results and prognosis. After having underlined some pathogenetic problems, the Authors show personal results and confirm the utility of an accurate endoscopical and clinical follow up especially for patients operated on since more than twenty years.


Assuntos
Carcinoma/etiologia , Úlcera Duodenal/cirurgia , Gastrectomia/métodos , Jejuno/cirurgia , Neoplasias Gástricas/etiologia , Úlcera Gástrica/cirurgia , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Estudos Retrospectivos , Fatores de Tempo
13.
G Chir ; 10(10): 545-8, 1989 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-2518290

RESUMO

Out of 618 cases of colon cancer treated between 1976 and 1986, 25 had an unusual local invasion. They underwent radical surgery with total resection of one or more adjacent organs. This group is made of 17 female and 8 male patients, with an average age of 58 years. All the patients underwent resection of the colon with radical excision of the locally invaded organs. Only one case of postoperative death is recorded. Postoperative surgical complications were rare. This experience confirms that colic resection extended to adjacent organs invaded by the tumor gives a low risk of relapse and satisfying long term results in relatively young patients with good general conditions and without remote metastases.


Assuntos
Neoplasias do Colo/cirurgia , Neoplasias Retais/cirurgia , Adulto , Idoso , Neoplasias do Colo/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Neoplasias do Colo Sigmoide/cirurgia
14.
Med Eng Phys ; 34(9): 1339-55, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22472525

RESUMO

The ossicular chain of the human middle ear has a key role in sound conduction since it transfers vibrations from the tympanic membrane to the cochlea, connecting the outer and the inner part of the hearing organ. This study reports firstly a description of the main anatomical features of the middle ear to introduce a detailed survey of its biomechanics, focused on model development, with a collection of geometric, inertial and mechanical/material parameters. The joint issues are particularly discussed from the perspective of developing a model of the middle ear both explanatory and predictive. Such a survey underlines the remarkable dispersion of data, due also to the lack of a standardization of the experimental techniques and conditions. Subsequently, a 3D multi-body model of the ossicular chain and other structures of the middle ear is described. Such an approach is justified as the ossicles were proven to behave as rigid bodies in the human hearing range and was preferred to the more widely used finite element one as it simplifies the model development and improves joint modeling. The displacement of the umbo (a reference point of the tympanic membrane) in the 0.3-6kHz frequency range was defined as input of the model, while the stapes footplate displacement as output. A parameter identification procedure was used to find parameter values for reproducing experimental and numerical reference curves taken from the literature. This simple model might represent a valid alternative to more complex models and might provide a useful tool to simulate pathological/post-surgical/post-traumatic conditions and evaluate ossicular replacement prostheses.


Assuntos
Ossículos da Orelha/anatomia & histologia , Modelos Anatômicos , Fenômenos Biomecânicos , Calibragem , Ossículos da Orelha/fisiologia , Análise de Elementos Finitos , Humanos , Ligamentos/anatomia & histologia , Ligamentos/fisiologia , Movimento
15.
J Biomech ; 44(7): 1219-36, 2011 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-21376326

RESUMO

The tympanic membrane is a key component of the human auditory apparatus which is a complex biomechanical system, devoted to sound reception and perception. Over the past 30 years, various bioengineering approaches have been applied to the ear modeling and particularly to the middle part. The tympanic membrane, included in the middle ear, transfers sound waves into mechanical vibration from the ear canal into the middle ear. Changes in structure and mechanical properties of the tympanic membrane due to middle ear diseases or damages can deteriorate sound transmission. An accurate model of the tympanic membrane, which simulates the acoustic-mechanical transmission, could improve clinical surgical intervention. In this paper a detailed survey of the biomechanics and the modeling of the tympanic membrane focusing on the finite element method is conduced. Eight selected models are evaluated and compared deducing the main features and most design parameters from published models, mainly focusing on geometric, constraint and material aspects. Non-specified parameters are replaced with the most commonly employed values. Our simulation results (in terms of modal frequencies and umbo displacement), compared with published numerical and experimental results, show a good agreement even if some scattering appears to indicate the need of further investigation and experimental validation.


Assuntos
Membrana Timpânica/fisiologia , Acústica , Fenômenos Biomecânicos , Cadáver , Calibragem , Simulação por Computador , Orelha Média/fisiologia , Elasticidade , Audição , Humanos , Modelos Anatômicos , Modelos Biológicos , Pressão , Som , Vibração
16.
J Biomech ; 44(13): 2418-26, 2011 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-21767843

RESUMO

Abdominal aortic aneurysm (AAA) is a cardiovascular disease with high incidence among elderly population. Biomechanical computational analyses can provide fundamental insights into AAA pathogenesis and clinical management, but modeling should be sufficiently accurate. Several constitutive models of the AAA wall are present in the literature, and some of them seem to well describe the experimental behavior of the aneurysmatic human aorta. In this work we compare a two (2FF) and a four (4FF) fiber families constitutive models of the AAA wall. Both these models satisfactorily fit literature data from biaxial tests on the aneurysmatic tissue. To investigate the peculiar characteristics of these models, we considered the problem of AAA inflation, and solved it by implementing the constitutive equations in a finite element code. A 20% axial stretch was imposed to the aneurysm ends, to simulate the physiological condition. Although fitted on the same dataset, the two material models lead to considerably different outcomes. In particular, adopting a 4FF strain energy function (SEF), an increase of the circumferential stress values can be observed, while higher axial stresses are recorded for the 2FF model. These differences can be attributed to the intrinsic characteristics of the SEFs and to the effective stress field, with respect to the one experienced in biaxial experimental tests on which the fitting is based. In fact the two SEFs appear similar within the region of the stress-strain experimental data, but become different outside it, as in case of aneurysms, due to the effects of the data extrapolation process. It is suggested that experimental data should be obtained for conditions similar to those of the application for which they are intended.


Assuntos
Aneurisma da Aorta Abdominal/patologia , Modelos Cardiovasculares , Aneurisma da Aorta Abdominal/fisiopatologia , Fenômenos Biomecânicos , Simulação por Computador , Humanos , Computação Matemática
17.
Acta Trop ; 117(3): 189-95, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21172297

RESUMO

We evaluated the effect of Ascaris lumbricoides on Giardia duodenalis infection and TH1/TH2 type immune mechanisms toward this parasite in 251 rural parasitized and 70 urban non-parasitized school children. The children were classified according to light (0-5000 eggs/g faeces) or moderate (>5001-50,000 eggs/g faeces) A. lumbricoides infection. Anti G. duodenalis skin hyper-reactivity, IgE, IgG, IL-13, IFN γ, IL6 and IL-10 levels were compared among G. duodenalis infected and non-infected children according to light or moderate A. lumbricoides infection. It was found that 62% of the A. lumbricoides moderately infected children were co-infected by G. duodenalis compared to 45% of the lightly infected group. After treatment, 42% of the A. lumbricoides moderately group were infected with G. duodenalis compared to 11% of their lightly counterparts, being A. lumbricoides IL-10 levels higher (p<0.0001) in the moderately infected group. In the A. lumbricoides lightly parasitized children, G. duodenalis infection was associated to a significant increase (p<0.005) of the levels of G. duodenalis IL-13, IFN-γ, IL-6, IgE, IgG and skin test hyper reactivity. In contrast, there was no effect of G. duodenalis infection in the elevation of these parameters among the A. lumbricoides moderately parasitized group, being those levels similarly lower as those observed in the control group. Inverse correlations were found between the levels of anti G duodenalis antibodies, skin test hyper-reactivity and cytokines with the intensity of A. lumbricoides infection (p>0.0001) and A. lumbricoides IL-10 levels (p>0.0001), suggesting that co-infection with A. lumbricoides may affect both TH1 and TH2 type immunity against G. duodenalis that may play an important role in the susceptibility to the infection after chemotherapy in children from endemic areas.


Assuntos
Ascaríase/imunologia , Giardíase/imunologia , Imunomodulação , Animais , Anticorpos/imunologia , Ascaríase/complicações , Ascaríase/epidemiologia , Ascaríase/parasitologia , Ascaris lumbricoides/fisiologia , Estudos de Casos e Controles , Criança , Citocinas/imunologia , Giardia lamblia/fisiologia , Giardíase/complicações , Giardíase/epidemiologia , Giardíase/parasitologia , Interações Hospedeiro-Patógeno , Humanos , Hipersensibilidade/imunologia , Imunoglobulinas/imunologia , Contagem de Ovos de Parasitas , População Rural , Índice de Gravidade de Doença , Testes Cutâneos , Equilíbrio Th1-Th2 , Venezuela/epidemiologia
18.
Eur J Surg Oncol ; 37(1): 4-9, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21112721

RESUMO

Favorable oncological outcomes have been reported in several trials with the introduction of Cytoreductive Surgery (CRS) and Hyperthermic Intraperitoneal Chemotherapy (HIPEC) in the treatment of Advanced Epithelial Ovarian Cancer (EOC). However most of the studies testing the combined approach are observational and have been conducted in inhomogeneous series so that the evidence supporting the performance of this combined treatment is still poor. Median Overall and Disease Free Survivals of up to 64 months and 57 months, respectively have been reported. Although a rate of morbidity of up to 40% has been observed in some series the CRS + HIPEC continues to gain an increased popularity. Several prospective randomized trials are ongoing using the procedure in various time points of the disease. In this review several issues such as the impact of cytoreduction and residual disease (RD) on outcomes as well as the role of HIPEC will be updated from the literature evidence. Some controversial points HIPEC related will also be discussed. Recent experiences regarding the introduction of a more aggressive surgical approach to upper abdomen to resect peritoneal carcinomatosis (PC) allowed increased rates of optimal cytoreduction and has demonstrated an apparent better outcome. This evidence associated with the positive results phase III trial testing normothermic intraperitoneal as first-line chemotherapy is guiding some investigators to propose the CRS + HIPEC in the primary setting. Several prospective phase II and III trials have recently been launched to validate the role of the combined treatment in various time points of disease natural evolution.


Assuntos
Antineoplásicos/administração & dosagem , Carcinoma Epitelial do Ovário , Terapia Combinada , Feminino , Humanos , Hipertermia Induzida , Infusões Parenterais , Neoplasias Epiteliais e Glandulares/cirurgia , Neoplasias Ovarianas/cirurgia , Padrão de Cuidado
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