Phallus eversion sexing in Phrynops geoffroanus (Testudines: Chelidae): a new non-invasive approach.

The sexing of species is an important tool for population management. In tortoises and turtles, sexing is usually done according to secondary characteristics, such as plastron morphology or phallus eversion techniques. In this paper, we present the phallus eversion method and compare its efficiency to other existing techniques. This new method aims at shortening the management time and reducing the physical aftereffects on the animals, fostering the clinical and reproductive management of Geoffroy's side-necked turtle (Phrynops geoffroanus) and related species. A sample of fifty individuals was taken in the central region of Piauí state, Northeastern Brazil. The proposed method consisted of moving the head from its resting position. The methods achieving a success rate higher than 80% were compared to each other as for the stimulation time required for phallus eversion. The method as here proposed achieved 100% efficiency in the sex determination of specimens with a linear carapace length between 10 and 34 cm. Also, when compared to the second most efficient method, it substantially reduced the time needed for managing the specimens (91%), avoiding possible sequelae in the individuals handled.

Antimyotoxic Activity of Synthetic Peptides Derived from Bothrops atrox Snake Gamma Phospholipase A2 Inhibitor Selected by Virtual Screening.

BACKGROUND: Several studies have aimed to identify molecules that inhibit the toxic actions of snake venom phospholipases A2 (PLA2s). Studies carried out with PLA2 inhibitors (PLIs) have been shown to be efficient in this assignment. OBJECTIVE: This work aimed to analyze the interaction of peptides derived from Bothrops atrox PLIγ (atPLIγ) with a PLA2 and to evaluate the ability of these peptides to reduce phospholipase and myotoxic activities. METHODS: Peptides were subjected to molecular docking with a homologous Lys49 PLA2 from B. atrox venom modeled by homology. Phospholipase activity neutralization assay was performed with BthTX-II and different ratios of the peptides. A catalytically active and an inactive PLA2 were purified from the B. atrox venom and used together in the in vitro myotoxic activity neutralization experiments with the peptides. RESULTS: The peptides interacted with amino acids near the PLA2 hydrophobic channel and the loop that would be bound to calcium in Asp49 PLA2. They were able to reduce phospholipase activity and peptides DFCHNV and ATHEE reached the highest reduction levels, being these two peptides the best that also interacted in the in silico experiments. The peptides reduced the myotubes cell damage with a highlight for the DFCHNV peptide, which reduced by about 65%. It has been suggested that myotoxic activity reduction is related to the sites occupied in the PLA2 structure, which could corroborate the results observed in molecular docking. CONCLUSION: This study should contribute to the investigation of the potential of PLIs to inhibit the toxic effects of PLA2s.

Phallus eversion sexing in Phrynops geoffroanus (Testudines: Chelidae): a new non-invasive approach

Abstract The sexing of species is an important tool for population management. In tortoises and turtles, sexing is usually done according to secondary characteristics, such as plastron morphology or phallus eversion techniques. In this paper, we present the phallus eversion method and compare its efficiency to other existing techniques. This new method aims at shortening the management time and reducing the physical aftereffects on the animals, fostering the clinical and reproductive management of Geoffroys side-necked turtle (Phrynops geoffroanus) and related species. A sample of fifty individuals was taken in the central region of Piauí state, Northeastern Brazil. The proposed method consisted of moving the head from its resting position. The methods achieving a success rate higher than 80% were compared to each other as for the stimulation time required for phallus eversion. The method as here proposed achieved 100% efficiency in the sex determination of specimens with a linear carapace length between 10 and 34 cm. Also, when compared to the second most efficient method, it substantially reduced the time needed for managing the specimens (91%), avoiding possible sequelae in the individuals handled.

Resumo A sexagem das espécies é uma ferramenta importante para o manejo populacional. Em tartarugas, cágados e jabutis, a sexagem geralmente é feita de acordo com características secundárias, como morfologia do plastrão ou técnicas de eversão do falo. Neste artigo, apresentamos o método de eversão do falo e comparamos sua eficiência com outras técnicas existentes. Este novo método visa encurtar o tempo de manejo e reduzir os efeitos colaterais físicos nos animais, promovendo o manejo clínico e reprodutivo do cágado-de-barbicha (Phrynops geoffroanus) e espécies relacionadas. Uma amostra de cinquenta indivíduos foi coletada na região central do estado do Piauí, Nordeste do Brasil. O método proposto consiste em remover a cabeça de sua posição de repouso. Os métodos que obtiveram índice de sucesso superior a 80% foram comparados entre si quanto ao tempo de estimulação necessário para a eversão do falo. O método aqui proposto alcançou 100% de eficiência na determinação do sexo de espécimes com comprimento de carapaça linear entre 10 e 34 cm. Além disso, quando comparado ao segundo método mais eficiente, reduziu substancialmente o tempo necessário para o manejo dos espécimes (91%), evitando possíveis sequelas nos indivíduos manuseados.

Phallus eversion sexing in Phrynops geoffroanus (Testudines: Chelidae): a new non-invasive approach / Sexagem por eversão do falo em Phrynops geoffroanus (Testudines: Chelidae): uma nova abordagem não invasiva

Abstract The sexing of species is an important tool for population management. In tortoises and turtles, sexing is usually done according to secondary characteristics, such as plastron morphology or phallus eversion techniques. In this paper, we present the phallus eversion method and compare its efficiency to other existing techniques. This new method aims at shortening the management time and reducing the physical aftereffects on the animals, fostering the clinical and reproductive management of Geoffroy's side-necked turtle (Phrynops geoffroanus) and related species. A sample of fifty individuals was taken in the central region of Piauí state, Northeastern Brazil. The proposed method consisted of moving the head from its resting position. The methods achieving a success rate higher than 80% were compared to each other as for the stimulation time required for phallus eversion. The method as here proposed achieved 100% efficiency in the sex determination of specimens with a linear carapace length between 10 and 34 cm. Also, when compared to the second most efficient method, it substantially reduced the time needed for managing the specimens (91%), avoiding possible sequelae in the individuals handled.

Resumo A sexagem das espécies é uma ferramenta importante para o manejo populacional. Em tartarugas, cágados e jabutis, a sexagem geralmente é feita de acordo com características secundárias, como morfologia do plastrão ou técnicas de eversão do falo. Neste artigo, apresentamos o método de eversão do falo e comparamos sua eficiência com outras técnicas existentes. Este novo método visa encurtar o tempo de manejo e reduzir os efeitos colaterais físicos nos animais, promovendo o manejo clínico e reprodutivo do cágado-de-barbicha (Phrynops geoffroanus) e espécies relacionadas. Uma amostra de cinquenta indivíduos foi coletada na região central do estado do Piauí, Nordeste do Brasil. O método proposto consiste em remover a cabeça de sua posição de repouso. Os métodos que obtiveram índice de sucesso superior a 80% foram comparados entre si quanto ao tempo de estimulação necessário para a eversão do falo. O método aqui proposto alcançou 100% de eficiência na determinação do sexo de espécimes com comprimento de carapaça linear entre 10 e 34 cm. Além disso, quando comparado ao segundo método mais eficiente, reduziu substancialmente o tempo necessário para o manejo dos espécimes (91%), evitando possíveis sequelas nos indivíduos manuseados.

Reducing marine eutrophication may require a paradigmatic change.

Marine eutrophication in the North-East Atlantic (NEA) strongly relies on nutrient enrichment at the river outlets, which is linked to human activities and land use in the watersheds. The question is whether human society can reduce its nutrient emissions by changing land use without compromising food security. A new version of Riverstrahler model (pyNuts-Riverstrahler) was designed to estimate the point and diffuse nutrient emissions (N, P, Si) to the rivers depending on land use in the watersheds across a large domain (Western Europe agro-food systems, waste water treatment). The loads from the river model have been used as inputs to three marine ecological models (PCOMS, ECO-MARS3D, MIRO&CO) covering together a large part of the NEA from the Iberian shelf to the Southern North Sea. The modelling of the land-ocean continuum allowed quantifying the impact of changes in land use on marine eutrophication. Pristine conditions were tested to scale the current eutrophication with respect to a "natural background" (sensu WFD), i.e. forested watersheds without any anthropogenic impact. Three scenarios representing potential management options were also tested to propose future perspectives in mitigating eutrophication. This study shows that a significant decrease in nitrogen fluxes from land to sea is possible by adapting human activities in the watersheds, preventing part of the eutrophication symptoms in the NEA rivers and adjacent coastal zones. It is also shown that any significant achievement in that direction would very likely require paradigmatic changes at social, economic and agricultural levels. This requires reshaping the connections between crop production and livestock farming, and between agriculture and local human food consumption. It also involves cultural changes such as less waste production and a shift towards lower-impact and healthier diets where half of the animal products consumption is replaced by vegetal proteins consumption, known as a demitarian diet (http://www.nine-esf.org/node/281/index.html).

Optimization of nanostructured lipid carriers for Zidovudine delivery using a microwave-assisted production method.

An adapted methodology for obtaining lipid nanoparticles that only uses the microwave reactor in the synthesis process was developed. The method has the following features: one-pot, one-step, fast, practical, economical, safe, readiness of scaling-up, lack of organic solvents and production of nanoparticles with low polydispersity index (PDI) (below 0.3). This new method was applied for the development of nanostructured lipid carriers (NLC) loaded with a hydrophilic drug, the antiretroviral agent zidovudine (AZT). The aim of the present work was to develop, evaluate and compare optimized NLC formulations produced by two different methods - hot ultrasonication and microwave-assisted method. The development and optimization of the NLC formulations were supported by a Quality by Design (QbD) approach. All formulations were physicochemically characterized by the same parameters. The optimized formulations presented a suitable profile for oral administration (particle size between 100 and 300 nm, PDI < 0.3 and negative zeta potential >-20 mV). Furthermore, the morphologies assessed by TEM showed spherical shape and confirmed the results obtained by DLS. Both AZT loaded formulations were physically stable for at least 45 days and non-toxic on Jurkat T cells. Drug release studies showed a controlled release of AZT under gastric and plasma-simulated conditions.

Diversity of human papillomavirus in the anal canal of men: the HIM Study.

Human papillomavirus (HPV) infections are associated with the development of anogenital lesions in men. There are no reports describing the distribution of non-α HPV types in the anal canal of a sexually diverse group of men. The HPV Infection in Men (HIM) Study is a multicentre study on the natural history of HPV infection in Brazil, Mexico, and the USA. At baseline, 12% of anal canal PCR HPV-positive specimens were not typed by the Roche Linear Array, and were considered to be unclassified. Our goals were to characterize HPVs among these unclassified specimens at baseline, and to assess associations with participant socio-demographic and behavioural characteristics. Unclassified HPVs were typed by sequencing of amplified PGMY09/11 products or cloning of PGMY/GP + nested amplicons followed by sequencing. Further analysis was conducted with FAP primers. Of men with unclassified HPV in the anal canal, most (89.1%) were men who have sex with women. Readable sequences were produced for 62.8% of unclassified specimens, of which 75.2% were characterized HPV types. Eighteen, 26 and three different α-HPV, ß-HPV and γ-HPV types were detected, respectively. α-HPVs were more commonly detected among young men (18-30 years) than among older men (45-70 years), whereas ß-HPVs were more frequent among mid-adult men (31-44 years). ß-HPVs were more common among heterosexual men (85.0%) than among non-heterosexual men. All ß-HPVs detected among non-heterosexual men were ß2-HPV types. The high prevalence of ß-HPV in the anal canal of men who do not report receptive anal sex is suggestive of other forms of transmission that do not involve penile-anal intercourse.

A cumulative case-control study of risk factor profiles for oncogenic and nononcogenic cervical human papillomavirus infections.

Human papillomaviruses (HPVs) play an essential role in the etiology of cervical cancer, but besides an established role for sexual transmission, little is known about other risk factors for HPV infection. Risk factors for nononcogenic, oncogenic, and HPV 16 cervical infections were investigated using a cumulative case-control approach nested in an ongoing cohort study of low income women from São Paulo, Brazil. HPV DNA was detected and typed by the MY09/11 PCR protocol. Risk factor information was obtained via interviews. In a case-control analysis, we compared women who harbored infections with exclusively nononcogenic types (n = 123), exclusively oncogenic types (n = 94), and any HPV 16 (n = 60) to women remaining HPV-negative (n = 512) throughout 1 year of follow-up. A strong negative association was found between age and oncogenic infections, but not with nononcogenic infections. Oral contraceptive use was strongly and exclusively associated with oncogenic and HPV 16 infections. Markers of sexual activity were associated with all types of infections, although with varying strengths. Our results suggest some important differences in the epidemiological correlates of HPV infection according to oncogenicity that may have implications for the-planning of specific preventive strategies aiming at reduction of cervical cancer risk.

Recovery of Cryptosporidium oocysts and Giardia cysts from source water concentrates using immunomagnetic separation.

Immunomagnetic separation (IMS) procedures for the simultaneous isolation of Cryptosporidium oocysts and Giardia cysts have recently become available. We validated Dynal's GC-Combo IMS kit using source water at three turbidity levels (5000, 500 and 50 nephelometric turbidity units [ntu]) obtained from different geographical locations and spiked with approximately 9--11 (oo)cysts per ml. Mean recoveries of Cryptosporidium oocysts and Giardia cysts in deionized water were 62% and 69%, respectively. In turbid water matrices, mean recoveries of Cryptosporidium oocysts were between 55.9% and 83.1% while mean recoveries of cysts were between 61.1% and 89.6%. Marginally higher recoveries of the heat inactivated (oo)cysts were observed (119.4% Cryptosporidium oocysts and 90.9% Giardia cysts) in deionized water when compared with recoveries of viable (oo)cysts (69.7% Cryptosporidium oocysts and 79% Giardia cysts). Age of (oo)cysts on recoveries using the GC-Combo IMS kit demonstrated no effects up to 20 months old. Recovery of Giardia cysts was consistent for isolates aged up to 8 months (81.4%), however, a significant reduction in recoveries was noted at 20 months age. Recoveries of low levels (5 and 10 (oo)cysts) of Cryptosporidium oocysts and Giardia cysts in deionized water using IMS ranged from 51.3% to 78% and from 47.6% to 90.0%, respectively. Results of this study indicate that Dynal's GC-Combo IMS kit is an efficient technique to separate Cryptosporidium/Giardia from turbid matrices and yields consistent, reproducible recoveries. The use of fresh (recently voided and purified) (oo)cysts, aged (oo)cysts, viable and heat-inactivated (oo)cysts indicated that these parameters do not influence IMS performance.

Posttraining presentation of a flashing light alters retrieval of a two-way active avoidance task in rats.

Rats were trained and tested in a two-way active avoidance task (30 trials, 0.4-mA footshock, 24-h training-test interval). Exposure to an open field with flashing light (60-W lamp, 30 Hz, for 7 min, OFL) 2 h after training caused a retrieval impairment for the avoidance task, a phenomenon called retroactive interference. Animals familiarized with the OFL 24 h before training showed no retrieval impairment when exposed to the OFL 2 h after training. Both adrenal medullectomy (performed 7 to 14 days before training) and dexamethasone treatment (2 mg/kg, injected IP 24 h and 12 h before training) prevented the OFL interfering effect. Time-course experiments revealed that OFL presented either 1 or 4 h after training caused no retrieval deficit, and that animals exposed to the OFL 2 h after training and receiving another OFL presentation 1 or 2 h, but not 4 h, prior to testing had normal retrieval performance. These results suggest: 1) that the retroactive interference caused by presentation of OFL 2 h after training is due to failure of retrieval of the avoidance task since it is counteracted by the pretest presentation to the OFL, 2) that the OFL-induced retrieval interfering effect partly depends on the novelty of the OFL situation, and on the functional integrity of pituitary ACTH and adrenomedullar-dependent mechanisms and 3) that there are different mechanisms involved in posttraining and pretest OFL effects since they present distinct time-courses.

Low prevalence of human papillomavirus in a geographic region with a high incidence of head and neck cancer.

BACKGROUND: The main purpose of this study was to determine the prevalence of human papillomavirus (HPV) infection in patients with head and neck carcinomas from Brazil. MATERIALS AND METHODS: Forty-five patients with head and neck squamous cell carcinoma were included in the study, from 1995 to 1996. Forty-two were male and 3 female, with age ranging from 32 to 82 years (median 61). Five patients (11%) did not have previous history of use of tobacco and 38 (90.5%) were heavy smokers. Tumor sites were pyriform sinus, 10; tongue, 11 (oral, 6; base, 5); larynx, 7; floor of mouth, 3; tonsil, 6; retromolar area, 3; inferior gingiva 2; buccal mucosa, 2; and maxillary sinus in 1 patient. Twenty-five were stage IV, 17 stage III, and 3 stage II. RESULTS: The presence of HPV DNA was detected in 5 of 45 patients (11%), all of them with HPV 16. Two patients had HPV DNA in normal mucosa and tumor tissue, 1 patient had HPV DNA only in the normal mucosa and tumor tissue, 1 patient had HPV DNA only in the normal mucosa, and 2 patients were positive for HPV DNA in tumor tissue. Four patients were male and 1 was female; 2 patients were nonsmokers. Three patients had tonsil carcinoma, 1 patient had a tongue carcinoma, and 1 patient had a pyriform sinus cancer. CONCLUSIONS: The role of chemical carcinogens seems to be more important in the genesis of head and neck cancer than is HPV infection. The presence of HPV DNA in 5 of 45 patients stimulates further investigation to determine the role of HPV as a risk factor for head and neck carcinoma.

Estrogen and progesterone receptors in human papilloma virus-related cervical neoplasia.

Estrogen (ER) and progesterone (PR) receptors in the normal uterine cervix, cervical intraepithelial neoplasia and invasive carcinoma were studied in consecutive samples from Hospital do Cáncer, São Paulo, between 1996 and 1997. Tissue was collected by removing a fragment of the tumoral area using a 5-mm diameter biopsy punch, followed by removal of a macroscopically normal area as close as possible from the tumor. Histopathological confirmation was obtained for all specimens analyzed. A total of 24 normal tissues, 17 cases of cervical intraepithelial neoplasia and 7 of invasive carcinomas were studied. The ER/PR ratio was determined by immunohistochemistry using monoclonal antibodies specific for each receptor. Adjacent tissue slides were submitted to generic PCR for human papillomavirus (HPV) DNA detection followed by typing by dot blot hybridization. About half (45.8%) of the tumors were HPV DNA positive while 29.1% of the patients were also HPV positive in their respective normal tissue. ER was negative in the tumoral epithelium of 11 HPV-positive patients (P=0.04). There was a trend in the ER distribution in normal tissue that was opposite to that from lesions, but it was not statistically significant (P=0.069). No difference in ER distribution in stromal tissues was observed between HPV-positive and HPV-negative tissues. PR staining was negative in the epithelium of all cases studied. The results obtained from this small number of cases cannot be considered to be conclusive but do suggest that factors related to viral infection affect the expression of these ER/PR cervix receptors.

Factors influencing regional lymph node metastasis from laryngeal carcinoma.

A series of 103 cases of laryngeal carcinoma subjected either to a unilateral or to a bilateral comprehensive neck dissection was reviewed with reference to risk factors influencing regional lymph node metastasis. The sensitivity of clinical examination was only 67.4%, while the specificity was 88.3%. Most metastases were in the upper and middle jugular chain of nodes (levels 2 and 3). Only patients with positive nodes at levels 2, 3, and/or 4 had histologically positive nodes at levels 1 or 5. Selected demographic, clinical, and pathologic variables were analyzed with respect to their potential predictive value regarding the risk of histologically proven neck node metastasis. Logistic regression analysis demonstrated that tumor site and histologic grade were the most important predictors of lymph node metastasis. Considering only NO cases, the likelihood of occult metastasis was significantly affected exclusively by tumor site (higher risk for supraglottic lesions).

Therapeutic association for nasopharyngeal cancer.

The authors studied retrospectively 16 cases of malignant epithelial nasopharyngeal tumors which were treated at the Head and Neck Service of the Heliópolis Hospital, São Paulo, Brasil, from December 1977 to December 1983. The treatment was intra-arterial chemotherapy (IAC) followed by radiotherapy. The chemotherapeutic schedules were: methotrexate and vincristine, methotrexate, bleomycin and vincristine (2 different schedules) and methotrexate, bleomycin, vincristine and cisplatinum. Objective responses to IAC were observed in 18.6% of the cases. Only 3 patients are alive at 26, 37 and 53 months; 2 of them had exhibited response to IAC. The authors analyze the results and suggest randomized trials in order to determine the exact effects of this method of treatment.

[Association of chemotherapy and radiotherapy in the treatment of advanced cancer of the head and neck]. / Association chimio-radiothérapique dans le traitement des cancers avancés de la téte et du cou.

At the Head and Neck and Roentgentherapy Services of Fundaçao Antonio Prudente, São Paulo, Brazil, 38 patients with advanced cancer of the oral cavity and oropharynx, were divided into two groups: the first, submmited to treatment with Bleomycin and Linear Acelerator, and the second to isolated irradiation. Both groups received 7 000 rads in 32 days, and to the association group, Bleomycin was administered in dosis of 300 mgs. The authors concluded that, that Chemo-Radiotherapic association didn't increase the survival rate.

Plague surveillance in Brazil: 1983-1992.

Plague caused by Yersinia pestis, has persisted in Brazil in several natural foci spread throughout rural areas in the States of Ceara, Paraiba, Pernambuco, Piaui, Rio Grande do Norte, Alagoas, Bahia, Minas Gerais and Rio de Janeiro. Nationwide surveillance of plague in Brazil based on serological testing started in 1983. We now present an update report of the examinations carried out in our laboratory from 1983 to 1992. The passive hemagglutination test for antibodies against fraction 1A antigen of Y. pestis and the passive hemagglutination inhibition control were employed for testing a total of 220,769 sera. Samples analyzed included 2,856 sera from clinically diagnosed plague cases or suspects, 49,848 sera from rodents of 24 species and 2 species of small wild carnivores (marsupials), 122,890 sera from dogs, and 45,175 sera from cats. Specific antibodies were found in 92 (3.22%) human sera; 143 (0.29%) sera from rodents of 8 species and from the two species of marsupials, 1,105 (0.90%) sera from dogs and 290 (0.64%) sera from cats. The presence of significant levels of specific anti-F1A antibodies among rodents and wild or domestic carnivores (dogs and cats) indicates that all the Brazilian plague foci remain active in spite of the absence of human cases in some of them.

Odontogenic adenomatoid tumor of the mandible (adenoameloblastoma).

Adenoameloblastoma may recur when treated incompletely by curettage. In the rare case of recurrence, an extensive and mutilating resection may become necessary. A correct diagnosis must be made in cases of atypical ameloblastomas in order to avoid unnecessary radical surgery. In doubtful cases, biopsy with histopathologic examination is indicated. Acknowledgment: We thank Mrs. Frieda Werebe for organizing this manuscript.

Computerized electrophysiological evaluation of muscular fatigue.

Muscular fatigue was studied in relation to different types of exercises. Thirty rats were divided in three groups: control, aerobic (running) and anaerobic exercises (weight lifting). Computerized measures of fatigue were done, using a special software that has the ability to generate impulses in different intensities. A fatigue index was obtained in a way that the greater the fatigue, the smaller was this index. Relationship among the three groups was possible and we are able to observe that the weight lift group (anaerobic exercises) performed better when compared with the two other groups.

Histopathologic features and management of ameloblastoma: study of 20 cases.

BACKGROUND: Odontogenic ameloblastoma (OA) of the jaws is a rare neoplasia of the oral cavity (0.78%) with a 5:1 mandible/maxilla relation, with the molar region and the ascendant ramus being the most affected areas. Comparing our results with the literature demonstrated to us that this tumor may be considered to be a worldwide problem due to the similarity in clinical findings among different ethnic groups CASE SERIES: The purpose of this study of 20 patients with ameloblastoma of the mandible and maxilla diagnosed at the Stomatology and Head and Neck Services of Heliópolis Hospital, São Paulo, Brazil, from 1980 to 1997, was to establish the histopathologic pattern of classification of those tumors through optical microscopy and the relation of this histopathology to therapeutic management. Using the Regeze, Kerr and Courtney classification (1978), we diagnosed follicular tumor in 11 cases, plexiform in 6 cases and unicystic in 3 cases, and performed surgical resection with a safety margin of 1.5 to 3.0 cm in the follicular and plexiform cases and bone curettage in the unicystic cases.

The value of therapeutic planning and the degree of experience of the surgical team on the results of cancer treatment of the larynx and hypopharynx.

This is a prospective study supported by 170 cases of epidermoid carcinoma of the larynx or hypopharynx, treated during the period from January of 1981 to January of 1988, at the Head and Neck Surgery Service of the Heliópolis Hospital Complex, São Paulo. The objective of this project was to evaluate the importance of surgeon experience with regard to the rates of post-operative complications and the rates of relapse and survival. The results of the 8 surgical specialists who integrate the permanent staff at the institute and who different varying degrees of experience with regard to time spent exercising their specialties were compared. The results obtained did not show a significant difference among the various surgeons, and this uniformity is explained by the fact that all the therapeutic planning was elaborated through consensus of the whole group, and this could have minimized the effect of experience of a surgeon responsible for the operation. The authors emphasize the importance of pre-operative evaluation for good results and propose that it is in the direction of complete mastery of preliminary work in the area that programs for the formation of new specialists should be directed.