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Dive into the research topics where Marcelo Mazza do Nascimento is active.

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Featured researches published by Marcelo Mazza do Nascimento.


Revista do Colégio Brasileiro de Cirurgiões | 2012

Vitamina D e cicatrização de pele: estudo prospectivo, duplo-cego, placebo controlado na cicatrização de úlceras de perna

Claudine J. C. Burkiewicz; Fernanda Ampesaan Guadagnin; Thelma Laroka Skare; Marcelo Mazza do Nascimento; Santiago Cirilo Nogueira Servin; Gleim Dias de Souza

OBJECTIVE To analyze the relation between vitamin D insufficiency and wound healing in patients with venous ulcers; to correlate vitamin D insufficiency with characteristics of the ulcer (size and pain) and to evaluate if reposition of vitamin D in these subjects expedites ulcer healing. METHODS We selected 26 patients with leg ulcers, and 26 control patients without ulcers, matched for gender, age, systemic arterial hypertension and tobacco use. The venous ulcer group was divided in two subgroups: one that received placebo (nine patients) and other receiving vitamin D, 50.000 IU per week over two months (13 patients). Blood was collected for 25 OH vitamin D dosage before and after the medication. In the ulcer group, we obtained data concerning demographics, leg ulcer size, as well as pain severity, measured by an analogical visual scale. Data was grouped in contingency and frequency tables, the tests of Fisher and chi-squared being used for nominal variables and Mann-Whitney for numerical variables. The adopted significance was of 5%. RESULTS We found vitamin D insufficiency in the great majority of the patients. The median level in the ulcer group was 17.05 ng/dl and 22.75 ng/dl in the group without ulcer (p=0,0182) No relation was found between the ulcer size without treatment and the level of vitamin D. After treatment, the average size of the ulcer changed from 25 cm² to 18 cm² in the patients that took vitamin D and from 27 cm² to 24,5 cm² in the placebo group (p=0,7051 and p=0,7877, respectively). Considering the variability of the size of the ulcer in the treatment group versus placebo group, the average size was equal to -0,75 cm² in the first group and +4cm² in the second (p=0,0676) CONCLUSION Patients with leg ulcers have more vitamin D deficiency. No difference in the ulcer characteristics was noted between those with and without vitamin D deficiency. There was a trend toward a better healing in those with vitamin D reposition.


Revista do Colégio Brasileiro de Cirurgiões | 2012

Alterações dos parâmetros clínicos e laboratoriais em pacientes obesos com diabetes melito tipo 2 submetidos à derivação gastrojejunal em y de Roux sem anel

Michelle Varaschim; Paulo Afonso Nunes Nassif; Luciana Bugmann Moreira; Marcelo Mazza do Nascimento; Grasiela Manfredi Nunes Vieira; Rodrigo Ferreira Garcia; Karen Megumi Sue; Manuela Aguiar Cruz

OBJECTIVES 1) To assess the changes in body weight and body mass index in grade 2 and 3 obese patients with type 2 diabetes mellitus, pre and postoperatively; 2) to assess the changes in pre and postoperative fasting blood glucose, postprandial glucose, glycated hemoglobin and insulin. METHODS A prospective study was undertaken with 40 selected patients with grade 2 and 3 obesity and type 2 diabetes mellitus, all with indication for surgical treatment of obesity. All patients underwent Roux-en-Y gastric bypass without ring. The clinical parameters weight and body mass index were analyzed, as well as the laboratory parameters fasting blood glucose, postprandial glucose, glycated hemoglobin, and insulin. The analyses were carried out in the preoperative period and at 60 days postoperatively. Statistical analysis was conducted with Students t and the Kolmogorov-Smirnov tests. RESULTS Mean preoperative weight was 107.3 kg, declining to 89.5 kg postoperatively. Mean initial body mass index was 39.5 kg/m², and 32.9 kg/m² at 60 postoperative days. Preoperative fasting blood glucose was 132 mg/dL, which was reduced to 40.4 mg/dL, on average, postoperatively. Postprandial blood glucose was 172 mg/dL in the preoperative period and 111.6 mg/dL in the postoperative measurement. Initial glycated hemoglobin was 7%, declining to 5.7% postoperatively. Preoperative and postoperative insulin levels were 29.6 µIU/mL and 13.9 µIU/mL, respectively. The level of significance was p<0.001 for all variables. CONCLUSION There was a statistically significant reduction in body weight and body mass index between the pre and postoperative periods, as well as in fasting blood glucose, postprandial glucose, glycated hemoglobin.


Acta Cirurgica Brasileira | 2012

Histopathological reaction over prosthesis surface covered with silicone and polyurethane foam implanted in rats

Jorge Wagenführ-Júnior; Jurandir Marcondes Ribas Filho; Marcelo Mazza do Nascimento; Fernanda Marcondes Ribas; Marcus Vinícius Wanka; Andressa de Lima Godoi

PURPOSES To evaluate whether polyurethane foam leads more intense foreign-body reaction than silicone foam. To compare the vascularization of the capsules surrounding the foam implants. To investigate if the capsule of polyurethane foam implanted has greater amount of collagen than that of silicone foam. METHODS Sixty-four young male Wistar rats were allocated into two groups: polyurethane foam and silicone foam. Subcutaneous discs were implanted into the dorsum of the animals in both groups. The capsules were assessed 28 days, two months, three months and six months postoperatively. Microscopic analysis with H&E stain was performed to evaluate the acute and chronic inflammatory process, foreign-body reaction and neovascularization. The analysis with picrosirius red was performed using the ImageProPlus software, to measure the number of vessels and collagen types I and III. RESULTS There were no statistical differences between the two groups regarding the acute and chronic inflammatory processes. All rats from the polyurethane group, in all times, exhibited moderate or intense foreign-body reaction, with statistic significant difference (p=0.046) when compared with the silicone group, in which the reaction was either mild or nonexistent at two months. Vascular proliferation was significantly different between the groups at 28 days (p=0.0002), with the polyurethane group displaying greater neovascularization with H&E stain. Similar results were obtained with picrosirius red, which revealed in the polyurethane group a much greater number of vessels than in the silicone group (p=0.001). The collagen area was larger in the polyurethane group, significantly at 28 days (p=0.001) and at two months (p=0.030). CONCLUSIONS Polyurethane foam elicited more intense foreign-body reaction when compared with silicone foam. The number of vessels was higher in the capsules of the polyurethane foam implants 28 days after the operation. The capsule of the polyurethane foam implants showed a greater amount of collagen than that of the silicone foam implants.


Acta Cirurgica Brasileira | 2010

Angiogenesis, fibrinogenesis and presence of synechiae after exeresis of a swine vocal fold mucosal microflap and use of topical mitomycin-C

Vinícius Ribas Carvalho Duarte Fonseca; Osvaldo Malafaia; Jurandir Marcondes Ribas Filho; Paulo Afonso Nunes Nassif; Nicolau Gregori Czeczko; Carmen Austrália Paredes Marcondes; Marcelo Mazza do Nascimento

PURPOSE To evaluate swine vocal fold healing in a period of 30 days after topical mitomycin-C application. METHODS Twelve swine underwent exeresis of mucosal flaps from the free edge of the anterior third of both vocal folds with a cold instrument (laryngeal scissors). The animals were divided into two groups: EG (Experimental Group), consisting of 6 animals undergoing topical MMC application (4 mg/dL) on the operated area for 4 minutes; CG (Control Group), 6 animals undergoing topical saline solution application on the operated area for 4 minutes. After 30 days, the animals were sacrificed and the larynges were collected and examined for the presence of synechiae as well as a histological immunohistochemical assessment of immature and mature collagen deposition, number of blood vessels and myofibroblasts. RESULTS Mature collagen deposition in the EG was 452.12 microm(2) and 1332.31 microm(2) in the CG; immature collagen deposition was 1511.73 microm(2) in the EG and 1020.61 microm(2) in the CG. The number of myofibroblasts was 1.556 in the EG and 3.583 in the CG. The number of blood vessels was 2.565 in EG and 6.917 in the CG. There were no synechiae in the two studied groups. CONCLUSIONS There was an increase in immature collagen deposition in the experimental group when compared with the control group. There was a decrease in mature collagen deposition in the experimental group when compared with the control group. There was a decrease in the number of myofibroblasts in the experimental group when compared with the control group. A decrease in blood vessels was observed in the experimental group when compared with the control group. There was no synechia formation in either studied group.


Acta Cirurgica Brasileira | 2009

Comparative study in swines' vocal cords healing after excision of fragment with CO2 laser with mitomycin and 5-fluorouracil postoperative topical application

Eduardo Baptistella; Osvaldo Malafaia; Nicolau Gregori Czeczko; Jurandir Marcondes Ribas-Filho; Paulo Afonso Nunes Nassif; Marcelo Mazza do Nascimento; Jan Pawel Andrade Pachnicki

PURPOSE To evaluate the deposition of collagen fibers at pigs vocal folds after topical use of mitomycin or 5-fluorouracil, when partial exeresis of mucosa layer had been promoted by CO2 laser. METHODS There were used 18 Larger white pigs which were anesthetized and submitted to mucosa fragments exeresis, bilaterally, at its free border. The animals were divided into 3 groups, each one with 6 animals: control group, without topical drug application; mitomycin group; and 5-fluorouracil group. After 30 days, the animals were subjected to euthanasia, and samples of the vocal folds were collected and stained by picrosirius red technique with polarization for quantification of total collagen deposition. RESULTS In control group, the mean rate of right vocal folds collagen deposition at submucosa consisted in a 3428.66 micrometers area. There was found an area whose size had, in average, 2196.36 micrometers, in mitomycin group, and 2269.19 micrometers, in 5-fluorouracil group. CONCLUSION Mitomycin and 5-fluorouracil had promoted beneficial change in vocal folds cicatrization with less collagen deposition, but there was no significant statistically difference when they were compared between themselves.


ABCD. Arquivos Brasileiros de Cirurgia Digestiva (São Paulo) | 2009

Regeneração do fígado de ratos após oclusão parcial da drenagem venosa hepática

Luiz Roberto Farion de Aguiar; Paulo Afonso Nunes Nassif; Carmen Australia Paredes Marcondes Ribas; Marcelo Mazza do Nascimento; Julio Cesar Wiederker; Jan Pawel Andrade Pachnicki; Edmar Stieven-Filho

BACKGROUND: Hepatic regeneration is a mechanism to overcome the loss of liver functional tissue. This process has been studied through different methods. AIM: To evaluate the effect of the partial occlusion of the hepatic venous drainage on the regeneration of the remainder livers in rats submitted to partial hepatectomy. METHOD: Liver biopsies from 30 male Wistar rats were collected, and after they were submitted two-third hepatectomy. The animals were divided in three groups: a control group and two study groups, which were submitted to different degrees of the right hepatic vein stenosis. After 96 hours of the stimulation for regeneration all rats were submitted to another hepatic biopsy. The analysis of the fragments was performed by immunohistochemistry for the Ki-67 and von Willebrand factor markers. The reading of the samples was done using the SAMBA 4000 system. Collagen deposition was evaluated by the trichromic Massons staining. RESULT: The cellular proliferation of the animals submitted to partial hepatectomy and stenosis of the right hepatic vein persists higher when compared to control group. The Label Index for Ki-67 was significantly higher post-hepatectomy in groups submitted to hepatic vein partial occlusion. The expression of von Willebrand factor was strongly decreased after the hepatectomy in all groups. There was little deposit of collagen in the hepatic tissue of animals with hepatic vein stenosis. CONCLUSION: Partial occlusion of the hepatic venous drainage in rats submitted to partial hepatectomy prolongs the time of hepatic cells proliferation when compared to the animals with vein of normal caliber. Consequently, there will be also a delay in the restoration of the extracellular matrix and in the formation of new sinusoidal vessels.


ABCD. Arquivos Brasileiros de Cirurgia Digestiva (São Paulo) | 2008

Expressão dos marcadores de angiogênese fator VIII e CD-34 no adenocarcinoma gástrico

Adriano Guimarães Ibiapina; Osvaldo Malafaia; Jurandir Marcondes Ribas-Filho; Nicolau Gregori Czeczko; Ulrich Andreas Dietz; Marcelo Mazza do Nascimento; Teresa Cristina Santos Cavalcanti

BACKGROUND: Gastric cancer remains a subject of great interest in several studies searching for understanding its genesis and, therefore, proposing new treatments. Currently special credits have been given to immunohistochemistry as various markers are being tested with uncertain efficacy on diagnosis. AIM: To identify and quantify the expression of Factor VIII and CD-34, angiogenesis markers, in gastric tumors by imaging cytometry. METHODS: Twenty-nine 29 gastric adenocarcinomas sampled-tissue in paraffin blocks underwent immunohistochemical angiogenesis markers evaluation for factor VIII and CD-34 and the marked slides were submitted to SAMBA 4000 reading. RESULTS:The investigation method offered two comparison parameters, marking index and optical density, showing up both in 17 cases. Significant numerical expression had been observed for both markers, but Factor VIII showed a better optical density average while CD-34 presented a better result for marking index. CONCLUSIONS: Image cytometry identified and quantified Factor VIII and CD-34 expressions in a reliable and satisfactory manner, revealing the presence of angiogenesis. Factor VIII enhanced in smaller areas with better quality while CD-34 enhanced greater areas with lower quality.


Revista do Colégio Brasileiro de Cirurgiões | 2012

Correlação entre o doppler da veia hepática direita com a biópsia transcutânea guiada pela ultrassonografia em hepatopatias

Gleim Dias de Souza; Luciana Rodrigues Queiroz; Carmen Australia Paredes Marcondes Ribas; Marcelo Mazza do Nascimento; Thelma Larocca Skare; Ronaldo Mafia Cuenca; Gustavo Henrique Soares Takano

OBJECTIVE To correlate chronic liver disease diagnosed by transcutaneous liver biopsy guided by ultrasound, with ultrasound findings with B-mode and Doppler of the right hepatic vein; 2) to compare the wave patterns between the study group and the control group; 3) to compare the right hepatic vein Doppler findings with histopathology findings as a possible marker of chronic liver disease. METHODS Were studied 38 patients with chronic liver disease diagnosed by biopsy and serology (study group) and 10 persons without serologic liver disease (control group), assessed only by ultrasound B-mode and Doppler. The criteria were based on histology classification of the Brazilian Society of Pathology for chronic hepatitis. Chi-square, Fishers exact and Student t tests were used. RESULTS The B-mode and Doppler ultrasound were useful in inferring the differentiation between individuals with chronic liver disease from normal. There were significant differences between the study group and the controls when comparing the histopathology findings, ultrasound B-mode and Doppler in relationship to the wave patterns of the right hepatic vein. CONCLUSION The correlation of liver biopsies with ultrasound B-mode and Doppler of hepatic vein was positive; 2) individuals with liver disease showed alterations in the flow of the right hepatic vein and normal subjects not, being the wave pattern in normal triphasic and in patients with chronic liver disease monophasic or biphasic; 3) Doppler of the right hepatic vein is useful marker for chronic liver disease.


Revista do Colégio Brasileiro de Cirurgiões | 2009

Anticorpos anticardiolipinas em úlceras de perna

Thelma Laroka Skare; Carmen Autralia Paredes Marcondes Ribas; Osvaldo Malafaia; Jurandir Marcondes Ribas Filho; Paulo Afonso Nunes Nassif; Marcelo Mazza do Nascimento; Vinícius Ribas Carvalho Duarte Fonseca

OBJECTIVE To verify the prevalence of IgG and IgM anticardiolipin antibodies in patients with leg ulcer (venous, arterial and diabetic) and if these patients can be identified by clinical means. METHODS A series of 151 patients with leg ulcer (81 venous, 50 diabetic and 20 arterial ulcers) and 150 controls were studied. In both groups it was searched the presence of IgG and IgM anticardiolipin by the ELISA method. In the leg ulcer group demographic data were obtained, data on the leg ulcer size and number as well as pain severity measured by an analogical visual scale. In statistic analysis, the adopted significance was of 5%. RESULTS It was found an anticardiolipin prevalence of 7.2% (n=12) in the leg ulcers group and of 1.3% (n=2) in the control group (p=0.01). Comparing the different ulcer types with control population, it was found that there was an increase in anticardiolipin antibodies in venous (p=0.02), and diabetic (p=0.01) but not in arterial ulcers (p=0.31). Leg ulcer patients with anticardiolipin did not differ from those without it in gender (p=0.98); ulcer size (p=0.6); pain severity (p=0.67), mean number of ulcers (p=0.38), mean disease duration time (p= 0.59) and previous history of venous thrombosis (p=0.69). CONCLUSION There is an increased prevalence of anticardiolipin antibodies in patients with venous leg ulcers and diabetic ulcers but not in those of arterial origin. Clinical characteristics of ulcers do not help in the identification of these patients.


Revista do Colégio Brasileiro de Cirurgiões | 2009

Contagem de plaquetas e caracterização clínica de úlceras de perna anticardiolipinas positivas

Thelma Laroka Skare; Carmen Autralia Paredes Marcondes Ribas; Osvaldo Malafaia; Jurandir Marcondes Ribas Filho; Paulo Afonso Nunes Nassif; Marcelo Mazza do Nascimento; Jan Pawel Andrade Pachnicki

OBJECTIVE To study the prevalence of anticardiolipin antibodies in patients with venous, diabetic and arterial leg ulcers and to verify if platelet count, previous history of venous thrombosis, obstetrical history and the finding of livedo reticularis are markers of this autoantibody positivity. METHODS 151 patients with leg ulcer (81 with venous, 50 with diabetic and 20 with arterial ulcers) and 150 controls were included. In both groups search for the presence of IgG and IgM anticardiolipin and platelet count was done. In the leg ulcer group demographic data, obstetrical history, previous history of venous thrombosis as well as presence of livedo reticularis by physical examination were pointed out. Data was grouped in contingency and frequency tables and the tests of Fisher and chi-squared were used for nominal variables and Mann Whitney and Kruskall Wallis for numerical variables. The adopted significance was of 5%. RESULTS It was found an anticardiolipin prevalence of 7.2% (n=12) in the leg ulcer group and of 1.3% (n=2) in the control group (p=0.01). Leg ulcer patients with anticardiolipin did not differ from those without it in gender (p=0.98), previous history of venous thrombosis (p=0.69), previous history of abortions (p=0.67) and platelet count (p=0.67). Only two patients had livedo reticularis which precluded any conclusion on this data. CONCLUSION There is an increased prevalence of anticardiolipin antibodies in the general population with leg ulcers. Clinical characteristics of ulcers as well as platelet count do not help in the identification of these patients.

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Osvaldo Malafaia

Federal University of Maranhão

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Nicolau Gregori Czeczko

Federal University of Maranhão

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Gleim Dias de Souza

Universidade Católica de Brasília

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Eduardo Baptistella

Federal University of Maranhão

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