Antônio Medeiros Dantas Filho

Tratamento tópico de queimaduras do dorso de ratos com ácido hialurônico

Previous studies have sugested that hyaluronic acid, a naturally occuring glycosaminoglycan in high doses and for a long time on extracelular matrix of healing wounds of fetus, is the responsible for the result of the fetal healing without scar and wound contraction. The present study investigated the topical effect of hyaluronic acid in burns of adult rats, until the complete epitelization of the lesions. Twenty Wistar rats weighting 225±15g were used. A 5 cm2 back burn was done in each rat under anesthesia. In the I group (n=10) the burns were treated with daily topical application of 1ml of 1% hyaluronic acid and in the II group (n=10) the treatment was done with 1ml of saline 0,9%, until the complete healing. The healing time was 29±1,33 days in the I group and 38±2,58 days in the II group . The histologic score was 27,0±2,78 in the I group and 18,1±3,66 in the II group. The differences were significant (p <0,05). The analysis of the aesthetic result revealed larger deformities in the scars of the II group (controls). In conclusion, the topic hyalurinic acid contributed to accelerate the healing rate, it improved the histologic evolution and turned better the aesthetic result in burns of adult rats.

Infecção hospitalar em pacientes cirúrgicos de hospital universitário

OBJETIVO: Analisar fatores intercorrentes e a incidencia da infeccao em pacientes operados no Hospital Universitario da UFRN. METODOS: Foram estudados, atraves de protocolo previamente estabelecido, 3.120 pacientes internados que se submeteram a procedimentos cirurgicos no periodo de janeiro de 1999 a outubro de 2002. RESULTADOS: O indice de infeccao hospitalar foi de 5,9%, e a topografia de maior incidencia foi a ferida operatoria (3,7%). Infeccao respiratoria ocorreu em 1,2%, urinaria em 0,6% e bacteremia em 0,1%. O indice de infeccao comunitaria foi de 9,2%, predominando infeccao urinaria (5%) e respiratoria (2,1%). Quanto ao grau de contaminacao das feridas operatorias, as feridas limpas (1479) apresentaram infeccao em 2,9%, as feridas limpas-contaminadas (1277) em 6,0% dos casos, as feridas contaminadas (270) em 15,1%, e as ferida infectadas (94) resultaram em infeccao em 30,75% dos casos. CONCLUSAO: Concluiu-se que a incidencia de infeccao cirurgica foi compativel com os indices na literatura mundial. A partir desses dados, ratifica-se a importância de medidas de controle de infeccao hospitalar de forma sistematica, como vem sendo realizado no hospital onde o estudo foi realizado.

Effects of the basic fibroblast growth factor and its anti-factor in the healing and collagen maturation of infected skin wound

PURPOSE The infection is one of the main factors that affect the physiological evolution of the surgical wounds. The aim of this work is to evaluate the effects of fibroblast growth factor (FGFâ) and anti-FGFâ in the healing, synthesis and maturation of collagen when topically used on infected skin wounds of rats. METHODS An experimental study was performed in 60 male Wistar rats. All animals were divided in two groups (A and B). Each group was divided in three subgroups A1, B1; A2, B2 and A3, B3. After anesthesia with pentobarbital, two open squared wounds (1cm(2)), 4 cm distant to each other, were done in the dorsal skin of all the rats. In group A (n=30) the wounds were contaminated with multibacterial standard solution, and in group B(n=30) the wounds were maintained sterile. These wounds were named F1 (for inflammation analysis) and F2 (for collagen study). The open wounds of A1 and B1 rats were topically treated with saline solution, A2 and B2 were treated with FGFâ and subgroups A3 and B3 were treated with FGFâ and anti-FGFâ. The rats were observed until complete epitelization of F2 wounds for determination of healing time and the expression of types I and III collagen, using Picro Sirius Red staining. Inflammatory reaction in F1 wounds was studied using hematoxilineosin staining. The three variable was measured by the Image Pro-Plus Média Cybernetics software. The statistical analysis was performed by ANOVA and Tukey test, considering p<0.05 as significant. RESULTS It was observed that infection retarded significantly (p<0.05) the time of wound scarring and the topical application of FCFb reverted the inhibition of healing caused by bacteria. The inflammatory reaction was greater in the subgroup B2 than in B1 and A3, and the difference was significant (p<0.05). It was observed greater expression of type I collagen in all the subgroups treated with FCFb, when compared with the untreated subgroups. Type III collagen was significantly decreased in wounds of B3 rats, comparing to the other subgroups. CONCLUSIONS The FCFb accelerated the healing of open infected wounds and contributed with maturation of collagen, enhancing the type I collagen density. The anti-FCFb antibody was able to attenuate the production of both type I and III collagen.

A nicotina atua como fator deletério na reparação da parede abdominal

OBJETIVE: An experimental study was done to evaluate the effect of nicotine on the healing of abdominal wall. METHODS: Sexteen Wistar rats weighing 210± 8g were randomly separated into two groups of eight rats each. In the group A Nicotine (Nicotinel O) was implanted in the back subcutaneous 5mg/Kg each two days, begining at the fifth preoperative day. A 5cm median laparotomy was done, sutured with nylon 5-0 and the rats were observed in individual cages. The group B (control) didn’t use nicotine. A multiperfurated silicone tube was implanted subcutaneously near the abdominal sutured lesion. In the tenth postoperative day 1ml of serous liquid was harvested from the silicone tube and a pO2 dosage was done. The rats were killed with overdose of anesthetic. A 2cm width transversal segment of abdominal wall was submited to tensile strength test by a tensiometer. A biopsy of the sutured area including muscle, aporeurosis and peritoneum was processed for histopatologic analysis by a digitalised system. The data were processed by the ANOVA and Newman-Keuls tests, considering significant the differences when p<0,05. RESULTS: In the group A the pO2 on the tissue serous liquid reached 17,75± 3,4 mmHg and in the group B (control) the pO2 = 40,75± 6,4 mmHg (p<0,01). The tensile strength reached 728,5± 161,75gf in the group A and 1241,6± 232gf in the control one (p<0,01).The mean density of the histopatologic elements was 105± 17,1 in group A and 146,2± 8,8 in group B (p<0,01). CONCLUSION: after evaluation of tissue pO2 , tensiometry and histopatology, the data permited to conclude that the nicotine has a deleterious effect on the healing the abdominal wall of rats.

Ação do fator de crescimento de fibroblasto básico na cicatrização da aponeurose abdominal de ratos

OBJECTIVE: As little is known about the use of basic Fibroblast Growth Factor (FCFb) in the healing of abdominal aponeurosis, an experimental work was done to study it. METHODS: Twenty Wistar rats randomly separated in two groups were used. They were anesthetised with pentobarbital 20 mg/Kg intraperitonealy, submited to a 4cm median laparotomy and the aponeurosis was sutured with nylon 5-0. In group I 5mg of FCFb was applied over the sutured aponeurosis end the group II received saline 0,9% over it. After seven days the rats were killed by an overdose of anesthetic. A transversal 1,5 cm wideness sample of aponeurosis was submited to tensil strenght test, using the assay device EMIC MF500. Biopsies from the sutured tissue were processed and colored by HE and Masson trichromic. The histopatologic data were quantitated and transformed into mean density by the digital equipment Image Pro-plus. The Student t test was used and the differences were significant when p<0,05. RESULTS: In group I the the mean tensil strength was 1.103± 103,39gf and the mean density of histopatologic data was 226± 29,32. In group II (control) the tensil strenght was 791,1± 92, 77gf and the histolopatogical density was 114,1± 17,01. The differences were statisticaly significant (p<0,01). CONCLUSION: In conclusion, our data show that FCFb induces an increase of tensil strenght of sutured aponeurosis of rats and turns better the histopatological parameters of wound healing.

O fator de crescimento de fibroblasto básico melhora a cicatrização de anastomoses duodenais em ratos

OBJECTIVE: Analysis of histopatological alterations, and pressure resistence in duodenal anastomosis treated with basic fibroblast growth factor (FGF-b). METHODS: Twenty Wistar rats were submited to a transversal duodenal section and subsequent anastomosis. They were randomly separated into four groups of five rats each: A1 and A2 (experimentals), in which FCFb was applied over the anastomosis; in B1 and B2 (controls), saline was use at the anastomosis site. The rodents were killed with an anesthetics overdosis, according to the following protocol: A1, B1 on 5th postoperative day and A2, B2 on the 7th one. A pressure resistence test of the anastomosis was done. The digitalized system Image ProPlus was used in order to analyse the mean density of the histopatological elements of healing duodenal tissues. RESULTS: All the rats survived without complications. In the group A1 the intraluminal pressure was 52± 14,4 mmHg and in group A2 it was 140± 34,8 mmHg. In the group B1 the pressure reached 33,6± 15,2 mmHg and in B2 it reached 105± 30,3. In group A1 the mean density of histopatological elements was 93± 9,3 and in A2 it was 181,8± 27,6. In the control groups B1 and B2 the mean densitys were 67,6± 16,7 and 101± 12,9 respectively. The statistical analysis detected a significant difference between the data of the experimental and control groups (p<0,05). CONCLUSION: the topical use of FGFb was able to enhance the resistence of duodenal anastomosis in rats observed and evaluated after five and seven postoperative days. The FCFb enhanced the neovascularization and the mean density of collagen, fibroblasts and inflammatory cells in the healing tissues.

Efeitos do fator de crescimento de fibroblasto básico (FCFbeta) na cicatrização de anastomoses do esôfago

BACKGROUND: Growth factors are substances that modulates tissue healing. Fibroblast growth factor is produced by platelets, macrofages and fibroblasts itself, stimulates cellular proliferation, collagen production and other elements of the cellular matrix, enhancing the healing proccess, even under adverse conditions. In order to study the influence of the basic Fibroblast Growth Factor (FCF-b) on the healing of esophageal anastomosis, an experimental model was produced to measure the anastomosis strenght, the amount of collagen and granulation tissue. METHODS: Twenty adult Wistar rats weighing 275±17g, were randomly allocated into two groups of ten each: Group A and B, were submitted to esophageal transection and anastomosis through a laparotomy approach. The anastomosis suture line of the group A was treated with a topical solution containing 10ng of FCF-b, whereas the control group (B) was treated with saline. Animals were killed on the 7th postoperative day, and the esophageal specimen removed to evaluate the anastomosis strenght, the input of inflamatory cells, and the amount of angiogenesis and collagen layered at the suture line. A digital system was used to process the histologic study. RESULTS: Group A showed greater amounts of inflamatory cells, angiogenesis and collagen density, as compared with the control group B. The quantitative mean density of the hystological data reached 9095.51±1284.5 in Group A and 7162.40±1273.19 in group B (p=0.013). The anastomosis suture line resistance to blowout was 210±18.88 mmHg in group A and 157±29.55 mmHg in group B (p=0.0024). CONCLUSION: This experimental model in rats confirms that FCF-b, when applied topically, enhances healing of esofageal anastomosis.

Repercussões do tempo operatório em pulmões de ratos idosos

The duration of the operations can represent an important factor for a series of postoperative complications, especially in the aged. OBJECTIVE: study the repercussion in the lungs, of operations of different duration. METHODS: Twenty aged rats (18 months old) and 20 young (3 months old) were randomly separated in groups A and B respectively. The groups were divided in A1, A2, A3, A4, B1, B2, B3 and B4, with five rats each. The animals were anesthetized with pentobarbital (20mg/Kg) intraperitoneal. In the group A1 and B1 a 30 minutes operation was done, in the groups A2 and B2 60 minutes, in the A3 and B3 the operation was done in 120 minutes and in the A4 and B4 control groups the animals were not operated. The procedure consisted of laparotomy that was opened and closed so many times as necessary to reach the operative times. After the 5th postoperative day the animals were killed with anesthetics overdosis and biopsies of both lungs were performed. The biopsies were processed and colored by HE. The histologic findings were transformed in scores for each group. RESULTS: the following results were seen: The groups of the young rats had the scores: A1= score 6, A2=11; A3=28; A4=5. Old rats had the following scores: B1=12; B2=34; B3=51 e B4=6. The statistical analysis revealed significant difference among the scores of the groups A and B. CONCLUSION: the prolonged time of surgery in rats contributes to significant histopatologic alterations in the lungs. As larger the operative time, larger and more frequent the pulmonary complications.

Lesões pulmonares provocadas pela nicotina por via subcutânea em ratos

ABSTRACT: Objective : The aims of this study were to determine and quantify the influence ofnicotine, applied subcutaneously, in the lungs of rats. Methods : Twenty Wistar rats weighing235–35g were randomly separated in two groups. The group I (n=10) received nicotine ( 2 mg/Kgbody mass/day) during 20 days and the group II (n=10) received placebo subcutaneously. Results :The results illustrate that in the group I resulted bronchopneumonia in 3 (30%) rats, alveolarleucocitosis in 10 (100%), septal leucocitosis in 7 (70%) and atelectasia was found in 2 (20%).Transformed in scores, the data totalized 52 points. The scores of the lesions observed in the lungsof group II rats reached 11 points (p <0,05). Conclusion : These findings indicate and concludethat the use of nicotine subcutaneously can be implicated in significant lung lesions in rats, whencompared with controls. KEY WORDS: Nicotine. Subcutaneous use. Lungs.CorrespondŒncia:Aldo da Cunha MedeirosAv. Miguel Alcides Araœjo 188959078-270 Natal, RN.

Translocação bacteriana para o pulmão na icterícia obstrutiva experimental em ratos

BACKGROUND: It has been demonstrated that obstructive jaundice provokes depression of the immunologic system, changes the pattern of intestinal bacterial colonization and possibly permits bacterial translocation lumen to the portal and systemic circulations. An experimental study performed done in rats to assess the incidence of enteric bacteria translocation to the lungs after choledocus closure. METHOD: Twenty Wistar male rats weighing 178 to 215g were randomly assigned to 2 groups. In group I, (n=10) it the choledocus was tied with 0000 silk suture and in group II the choledocus was manipulated with atraumatic instrument (sham operation). In the 7th day the animals were killed with anesthetic overdose, blood sample was colected for bilirrubin dosage and the lungs were ressected under aseptic conditions. Half of each lung was homogenized and cultured in agar McConkey and agar blood. The other half was processed by conventional histologic methods. The sections were cut and stained by Gram, haematoxilin and eosin and examined with light microscopy. Data were analyzed by t test (p <0,05). RESULTS: Mean total bilirrubin was 18,7±3,6 and 0,7±0,2 in groups I and II, respectively (p<0,05). Colonies of Klebsiela sp were isolated in the lungs of 30% and E. coli in 20% of group I, and histopathological scores presented an average of 6.2±2.08. No bacteria was detected in the lungs of group II and the scores histopathological reached 1,8±1,16 (p <0,05). CONCLUSIONS: Obstructive resulting jaundice in rats promotes translocation of Gram negative bacteria to the lungs, resulting in significant histopatologic alterations.