Estudo da resistência cicatricial cutânea de ratos tratados com óleo de pequi (Caryocar brasiliense) / Study of skin scarring resistance of rats treated with pequi oil (Caryocar brasiliense)

Introdução: Existem vários estudos sobre a utilização do pequi (Caryocar brasiliense) no processo cicatricial; contudo, em poucos trabalhos desenvolvidos, avaliou-se resistência dos tecidos à tensão pós-tratamento. Objetivo: Analisar a tensão cicatricial em incisões cutâneas de ratos, após terapia com Caryocar brasiliense. Método: Vinte ratos Wistar, divididos em dois grupos (placebo/tratado), sofreram incisão cutânea no dorso. O grupo tratado recebeu doses diárias de óleo de Caryocar brasiliense, e o placebo aplicação de óleo mineral. Após sacrifício, em sete e quatorze dias pós-cirurgia, amostras de pele foram submetidas à análise tênsil-histológica. Resultados: Observou-se diferença significante intergrupos na força máxima de tração, assim como uma elevação da síntese de colágeno na área das lesões no grupo tratado com óleo Caryocar brasiliense. Conclusão: A terapia com óleo de Caryocar brasiliense aumenta a resistência tênsil da pele, melhorando a resposta reparacional, reduzindo riscos de deiscência e complicações pós-cirúrgicas.

Introduction: There are several studies on the use of Caryocar brasiliense in the scarring process; however, few studies have evaluated posttreatment skin tissue resistance to tension. Objective: To analyze the scar tension in skin incisions of rats after therapy Caryocar brasiliense. Method: Twenty Wistar rats were divided into two groups (placebo / rough) and suffered skin incision in dorso. The treatment group received daily dose of Caryocar brasiliense oil and the placebo group with application of mineral oil. After sacrifice, in seven fourteen days after surgery, skin samples were subjected to tensile-histological analysis. Results: There was a significant intergroup difference in the maximum strength of traction, as well as an increase in collagen synthesis in the area of lesions in the treated group. Conclusion: Treatment with oil from Caryocar brasiliense increases the tensile strength of the skin, improving the healing response and reducing the risks of dehiscence and postoperative complications.

Effect of glutamine supplementation on left colon healing in rats with extrahepatic biliary obstruction

PURPOSE: To evaluate the influence of glutamine and obstructive jaundice on left colon healing in rats. METHODS: Sixteen male rats were allocated across four groups: LG - Common bile duct ligation followed by colotomy and bowel suture on postoperative day 7. Supplementation with glutamine 2% from day 4 after duct ligation until euthanasia. L - Common bile duct ligation followed by colotomy and bowel suture on postoperative day 7. No glutamine supplementation. M - Common bile duct manipulation followed by colotomy and bowel suture on postoperative day 7. No glutamine supplementation. MG - Common bile duct manipulation followed by colotomy and bowel suture on postoperative day 7. Supplementation with glutamine 2% from day 4 after duct manipulation until euthanasia. On the day of euthanasia, bursting pressure of the sutured bowel segment was measured and samples were collected for histopathological analysis. RESULTS: There were no differences in bursting pressure among groups : LG vs. M (110 ± 28 vs. 173 ± 12; p = 0.08). Groups L and MG were not different from group M (156 ± 12 and 118 ± 22. Glutamine supplementation was associated with less edema, polymorphonuclear lymphocyte infiltration, bacterial colonies, and abscess formation, as well as with increased collagen formation. CONCLUSION: Obstructive jaundice had no negative effect and glutamine supplementation had no positive effect on colonic scar strength in rats. .

The effect of CPP-ACP and Nd:YAG laser on the bond strength of softened dentin

The purpose of this study was to investigate the effect of CPP-ACP treatment and Nd:YAG laser on microtensile bond strength (µTBS) of softened dentin. Sixty samples were obtained from thirty sound third molars. All samples were submitted to dentin softening procedure, by the immersion of the specimens in 30 mL of Sprite Zero for 30min. Afterwards, the samples were randomly divided according to the CPP-ACP treatment: CG-Control group; MP-treated with CPP-ACP paste (MI Paste); MPP-treated with CPP-ACP+900 ppm NaF paste (MI Paste Plus). Each group was further divided according to bonding procedure: NL-No laser; L–Laser irradiation after adhesive application and before polymerization. The laser parameters used were 1.4 W, 10 Hz, 140 mJ/pulse, with an optic fiber of 320 µm, generating energy of 174 J/cm2 per pulse. All samples were restored with Clearfil SE Bond/Filtek Z350 XT. After 24 h, the restored samples were cut into beams (± 1 mm2adhesive interface area) and subjected to a µTBS test. Data were analyzed by two-way ANOVA test and Holm-Sidak post-hoc method (α = 0.05). The treatment with CPP-ACP pastes did not significantly affect softened dentin µTBS (p = 0.070). Statistic revealed significant reduction on µTBS values for CG/L, leading to the rejection of the second null hypothesis (p < 0.001). Both CPP-ACP based pastes did not affect µTBS of softened dentin for the adhesive system utilized. The Nd:YAG laser irradiation after application of adhesive system did affect µTBS values of softened dentin samples untreated with CPP-ACP based pastes.

Effect of vitamin K1 supplementation on left colon healing in rats with extrahepatic biliary obstruction

PURPOSE: To evaluate the effects of vitamin K1 on wound healing in the left colon of rats with experimental biliary obstruction. METHODS: Sixteen male rats, divided into four groups of four animals each (L, M, LK, and MK), underwent colostomy followed by bowel suture in the left colon. Seven days before, animals in the L and LK groups had undergone common bile duct ligation. The animals in groups MK and LK received vitamin K1 supplementation. On day 7 after bowel suture, repeat laparotomy was performed for evaluation of colonic healing by burst pressure measurement and collection of samples for histopathological analysis. Changes in body weight were evaluated in the four groups. RESULTS: Weight loss was lower in animals supplemented with vitamin K. No significant differences were observed in burst pressure among the four groups (p>0.05). Histological analysis showed more hemorrhage and congestion in the biliary obstruction groups. Supplemented animals exhibited increased collagen formation and less edema and abscess formation. CONCLUSION: Vitamin K supplementation attenuated weight loss and improved colonic wound healing in rats. .

Inflammatory reaction and tensile strength of the abdominal wall after an implant of polypropylene mesh and polypropylene/poliglecaprone mesh for abdominal wall defect treatment in rats

PURPOSE: To compare the inflammatory reaction and the growing resistance of the abdominal wall with the use of poliglecaprone meshes and polypropylene meshes associated with poliglecaprone in the correction of abdominal defects. METHODS: Seventy-seven Wistar rats were divided into three groups: CG (non-operated animals: EG (polypropylene mesh) and UG (polypropylene and poliglecaprone mesh). A muscular and aponeurotic defect was formed and treated according to the group. Evaluations were made after 4, 7, 14, 28 and 56 days. The resistance and inflammatory pattern were studied. RESULTS: There was a gradual and significant gain in resistance, regularly in the EG and irregularly in the UG, which was lower on the 14th day (p=0.008). The inflammatory reaction was acute and more intense in the UG on the fourth day. At all other times, the inflammatory pattern was acute to chronic, similar in both groups, with minimum intensity on the 56th day. CONCLUSION: The greater resistance offered by the polypropylene mesh was regular and ascending, stabilizing on the 28th day, while that of the polypropylene/poliglecaprone was not even. In the end, the resistances were similar. The inflammatory response was greater in the UG on the fourth day and similar at all other times. .

Experimental evaluation of cyclic fatigue resistance of four different nickel-titanium instruments after immersion in sodium hypochlorite and/or sterilization

NiTi instruments have a high risk of separation due to torsional or flexural fatigue (cyclic fatigue). Chemomechanical preparation, cleaning procedures, chemical disinfection and sterilization cause the corrosion of endodontic instruments that may weaken the fracture resistance of the instruments. Objective To assess the effects of NaOCl immersion and autoclave sterilization on the cyclic fatigue resistance of ProFile, FlexMaster, Mtwo and TwistedFiles NiTi instruments (tip size 25, 0.06 taper, n=160). Material and Methods The instruments (n=10 for each subgroup) were dynamically immersed in NaOCl; immersed in NaOCl and sterilized in one autoclave cycle; 5 cycles immersed in NaOCl and sterilized in autoclave and not immersed in NaOCl and not sterilized (control group). Dynamic cyclic fatigue resistance was tested. The number of cycles to failure (NCF) were statistically analyzed (P<0.05). Results Kruskall-Wallis test indicated significant differences among the tested instruments in terms of NCF (P=0.000). The mean NCF of Mtwo (556.75) was higher than that of the Twisted File, Flexmaster and ProFile, 483.1, 376.12, 365.25, respectively. NaOCl immersion and autoclave sterilization have no effect on the NCF values of the tested instruments (P>.05). Conclusions Cyclic fatigue resistance of the tested NiTi instruments cannot be adversely affected by NaOCl immersion and autoclave sterilization. Production process (TwistedFiles) or design (Twisted Files, FlexMaster, Mtwo and ProFile) of the instruments can influence their cyclic fatigue resistance. .

Surface agents' influence on the flexural strength of bilaminated ceramics

The objective of this study was to evaluate the influence of different surface agents on the flexural strength of a ceramic system. Eighty bar-shaped specimens of zirconia were divided into four groups according to the agent to be used: group Control - to be cleaned with alcohol; group VM9 - application of a fluid layer of porcelain; group Effect Bonder - application of a bonding agent; and group Coloring Liquid - application of coloring liquid. All specimens received the porcelain application by the layering technique and were then subjected to thermocycling. The four-point bending test was performed to calculate the strength values (σ, MPa) and the failure modes were classified. ANOVA did not detect significant differences among the groups. The Weibull modulus were 5 (Control, VM9 and Effect Bonder) and 6 (Coloring Liquid). The cracking of the porcelain ceramic toward the interface was the predominant failure mode. It was concluded that the surface agents tested had no effect on the flexural strength of the bilaminated ceramic specimens.

Effect of sodium ascorbate on the bond strength of silorane and methacrylate composites after vital bleaching

We investigated the effect of sodium ascorbate (SA) on the microtensile bond strengths (MTBSs) of different composites to bovine enamel after vital bleaching with hydrogen peroxide (HP) or carbamide peroxide (CP). Thirty bovine incisors were randomly divided into five groups and treated with no bleaching application (control), 35% HP alone, 35% HP + 10% SA for 10 minutes (HP + SA), 16% CP alone, or 16% CP + 10% SA for 10 minutes (CP + SA). Specimens were restored with Silorane adhesive and Filtek Silorane composite (designated as S / group) or with Clearfil SE bond and Filtek Supreme XT (designated as F / group). Composite build-up was created on the enamel. Sectioned specimens (n = 10 per group; 1 mm2; cross-sectional area) were created and stressed in a universal testing machine at 1 mm/min crosshead speed. The application of 10% SA immediately after bleaching with 16% CP or 35% HP increased the enamel MTBS, regardless of the adhesive / composite resin used. The resulting MTBS values were similar to those of the control groups. Use of 16% CP and 35% HP alone decreased the enamel MTBS, regardless of the adhesive / composite resin used, with F / CP + SA = F / HP + SA = F / CP = S / CP + SA = S / HP + SA = S / C > S / CP = S / HP = F / CP = F / HP (p < 0.05). We concluded that the application of SA for 10 minutes immediately after vital bleaching increases the enamel BS for dimethacrylate- and silorane-based composites.

Effect of chlorhexidine on the bond strength of a self-etch adhesive system to sound and demineralized dentin

This study evaluated the effect of a 2% chlorhexidine-based disinfectant (CHX) on the short-term resin-dentin bond strength of a self-etch adhesive system to human dentin with different mineral contents. Dentinal mineralization was tested at 4 levels (sound, and after 2, 4, or 8 days of demineralization-remineralization cycles) and disinfectant at 2 levels [deionized water (DW, negative control) and CHX]. Dentin demineralization induced by pH-cycling was characterized by cross-sectional hardness (CSH). Each dentin surface was divided into halves, one treated with DW and the other with CHX (5 minutes). Each surface was bonded with a self-etch adhesive system and restored. The specimens were sectioned and subjected to microtensile bond testing. CSH and microtensile bond strength (µTBS) data were analyzed by regression analysis and ANOVA-Tukey tests (α = 5%), respectively. The groups treated with CHX resulted in mean µTBS similar to those found for the groups in which the dentin was exposed to DW (p = 0.821). However, mean µTBS were strongly influenced by dentin mineralization (p < 0.05): the bond strength found for sound dentin was lower than that found for dentin cycled for 8 days, which was even lower than the bond strengths for dentin cycled for 2 or 4 days. The results suggest that the degree of dentin demineralization affects the bond strength of self-etching adhesives, but the use of CHX does not modify this effect.

Evaluation of the abdominal wall cicatrization of rabbits exposed to nicotine and undergone abdominoplasty using nylon thread or cyanoacrylate / Avaliação da cicatrização da parede abdominal de coelhos expostos à nicotina e submetidos à abdominoplastia, utilizando-se nylon ou cianocrilato

PURPOSE: To compare the wound healing of the abdominal wall of rabbits exposed to nicotine and submitted to abdominoplasty using 2-octyl cyanoacrylate or nylon thread for the surgery suture. METHODS: Thirty two rabbits were used. They were divided in subgroups: A1, A2, B1 e B2. Group A received saline 0.9%; group B received nicotine, both groups for 14 days before surgery. We performed an abdominoplasty with a nylon suture into the A1 and B1 subgroups; as for A2 and B2 groups the suture was performed with cyanoacrylate. The euthanasia happened in the 14th post-operative day. After, we evaluated: swollen process, fibroblast proliferation, collagen, neovascularization, and macroscope and microscope epithelization of the scars. RESULTS: We observed the presence of eosinophils in all scars exposed to the cyanoacrylate, and a significant increase of neovascularization in the subgroup B2 comparing to the A2 one (p=0.037). The other variables haven't showed any statistical difference. CONCLUSIONS: Nicotine hasn't influenced the swollen process, the fibroblast proliferation, the presence of collagen, neither the epithelialization. The neovascularization showed cicatricial immaturity when comparing group A2 to group B2. The eosinophils in the scars repaired with glue showed that the substance has acted as an allergen.

OBJETIVO: Comparar a cicatrização da parede abdominal de coelhos expostos à nicotina e submetidos à abdominoplastia utilizando 2-octil cianoacrilato ou nylon na síntese cirúrgica. MÉTODOS: Utilizou-se 32 coelhos. Estes foram distribuídos em subgrupos: A1, A2, B1 e B2. O grupo A recebeu solução de NaCl 0,9%; o B recebeu nicotina, ambos durante 14 dias do pré-operatório. Nos subgrupos A1 e B1 foi realizada abdominoplastia e sutura com "nylon"; enquanto A2 e B2 a síntese ocorreu com cianoacrilato. A eutanásia ocorreu no 14º dia do pós-operatório. Na pesquisa avaliou-se: processo inflamatório, proliferação fibroblástica, colágeno, neovascularização, epitelização macro e microscópica das cicatrizes. RESULTADOS: Observou-se presença de eosinofilia em todas as cicatrizes expostas ao cianoacrilato, e aumento significativo da neovascularização no subgrupo B2 em comparação com o A2 (p=0,037). Demais variáveis não apresentaram diferença estatística. CONCLUSÕES: A nicotina não influenciou o processo inflamatório, a proliferação fibroblástica, a presença de colágeno e a epitelização. A neovascularização indicou imaturidade cicatricial na comparação dos grupos A2 e B2. A eosinofilia nas cicatrizes reparadas com cola indica que a substância atuou como alergeno.

Effectiveness of immediate bonding of etch-and-rinse adhesives to simplified ethanol-saturated dentin

This study examined the immediate bond strength of etch-and-rinse adhesives to demineralized dentin saturated with either water or absolute ethanol. The research hypothesis was that there would be no difference in bond strength to dentin between water or ethanol wet-bonding techniques. The medium dentin of 20 third molars was exposed (n = 5). The dentin surface was then acid-etched, left moist and randomly assigned to be saturated via either water wet-bonding (WBT) or absolute ethanol wet-bonding (EBT). The specimens were then treated with one of the following etch-and-rinse adhesive systems: a 3-step, water-based system (Adper Scotchbond Multipurpose, or SBMP) or a 2-step, ethanol/water-based system (Adper Single Bond 2, or SB). Resin composite build-ups were then incrementally constructed. After water storage for 24 h at 37°C, the tensile strength of the specimens was tested in a universal testing machine (0.5 mm/min). Data were analyzed by two-way ANOVA and Tukey's test (a = 5%). The failure modes were verified using a stereomicroscope (40'). For both adhesives, no significant difference in bond strength was observed between WBT and EBT (p > 0.05). The highest bond strength was observed for SB, regardless of the bonding technique (p < 0.05). No significant interaction between adhesives and bonding techniques was noticed (p = 0.597). There was a predominance of adhesive failures for all tested groups. The EBT and WBT displayed similar immediate bond strength means for both adhesives. The SB adhesive exhibited higher means for all conditions tested. Further investigations are needed to evaluate long-term bonding to dentin mediated by commercial etch-and-rinse adhesives using the EBT approach.

Influence of metoclopramide on abdominal wall healing in rats subjected to colonic anastomosis in the presence of peritoneal sepsis induced / Influência da metoclopramida na cicatrização da parede abdominal de ratos submetidos à anastomose colônica na vigência de sepse peritonial induzida

PURPOSE: To evaluate the effects of metoclopramide on abdominal wall healing in rats in the presence of sepsis. METHODS: 40 rats divided into two groups of twenty animals, subdivided into two subgroups of 10 animals each: group (E) - treated with metoclopramide, and saline-treated control group. The two groups were divided into subgroups of 10 to be killed on the 3rd day (n = 10) or day 7 (n = 10) after surgery. Sepsis was induced by cecal ligation and puncture. We performed also the section and anastomosis in left colon. The synthesis of the abdominal wall was made with 3-0 silk thread. We measured the breaking strength of the abdominal wall and made the histopathological evaluation. RESULTS: on 3rd day postoperative, the average breaking strength in the E group was 0.83 ± 0.66 and in group C was 0.35 ± 0.46 (p = 0.010). On the seventh day, the breaking strength in group E was11.44 ± 5.07, in group C 11.66 ± 7.38 (p = 1.000). The E7 group showed lower inflammatory infiltration, foreign body reaction, fibrin than control. CONCLUSION: animals treated with metoclopramide had a higher resistance of the abdominal wall on the 3rd postoperative day.

OBJETIVO: Avaliar os efeitos da metoclopramide na cicatrização da parede abdominal de ratos na vigência de sepse. METHODS: 40 ratos divididos em dois grupos de 20 animais, subdivididos em dois subgrupos de 10 animais cada: grupo (E) - tratado com metoclopramida, e o grupo controle tratado com solução fisiologica. Os dois grupos foram divididos em subgrupos de de 10 para serem mortos no dia 3 (n = 10) ou o dia 7 (n = 10) após a cirurgia. A sepse foi induzida por ligadura e perfuração cecal. Foi realizada também a secção e anastomose em cólon esquerdo. A síntese da parede abdominal foi feita com fio de seda 3-0. Mediu-se a força de ruptura da parede abdominal e foi feita uma avaliação histopatológica. RESULTADOS: No dia 3 pós-operatório, a força média de ruptura no grupo E foi de 0,83 ± 0,66 e no grupo C foi de 0,35 ± 0,46 (p = 0,010). No sétimo dia, a força de ruptura no grupo E foi 11.44 ± 5,07; no grupo C, 11,66 ± 7,38 (p = 1,000). O grupo E7 apresentou menor infiltração inflamatória e reação de corpo estranho do que o controle de fibrina. CONCLUSÃO: Animais tratados com metoclopramida apresentaram uma maior resistência da parede abdominal no 3º dia pós-operatório.

Rupture point analysis of intestinal anastomotic healing in rats under the action of pure Copaíba (Copaifera Iangsdorfii) oil / Análise do ponto de ruptura na cicatrização de anastomose intestinal em ratos tratados com óleo de Copaíba (Copaifera Iangsdorfii) puro

PURPOSE: Analyze the mechanical strength of digestive tract scar after intestinal anastomosis surgery in animals treated with pure Copaíba oil. METHODS: 60 Wistar rats, male, about 250 days old and weighting around 350g were used. The rats were randomly divided into two groups: Group O, with 30 animals that received Copaíba oil and Group C, with 30 animals that received saline. Each group was subdivided into three subgroups, containing 10 rats each. They were designated O7, O14, O28, C7, C14 and C28, according to the post-operative assessment date at 7, 14 and 28 days, respectively. On these dates euthanasia was performed with the removal of the bowel segment containing the anastomosis and assigning the samples to tensile test for assessing Maximum Stress, Maximum Tensile Strength and Maximum Rupture Strength. RESULTS: On the three variables of the study, the results indicate that, for the three assessment periods (7, 14 and 28 days) there was no significant difference between the oil and control groups. CONCLUSION: For the mechanical tests proposed by this study, Copaíba oil didn´t show any effectiveness in increasing the anatomosis strength.

OBJETIVO: Analisar a resistência mecânica da cicatriz do tubo digestivo, após cirurgia de anastomose intestinal em animais tratados com óleo da Copaíba puro. MÉTODOS: Foram utilizados 60 ratos Wistar, machos, com cerca de 250 dias e peso médio de 350g. Os ratos foram divididos aleatoriamente em dois grupos: Grupo O, com 30 animais, que receberam óleo da Copaíba e Grupo C, com 30 animais, que receberam solução fisiológica. Cada grupo foi subdividido em três subgrupos, contendo 10 ratos cada. Suas denominações foram O7, O14, O28, C7, C14 e C28, segundo o tempo de avaliação pós-operatória em 7, 14 e 28 dias, respectivamente. Nessas datas foi realizada a eutanásia com a retirada do segmento intestinal contendo a anastomose, destinando as amostras ao teste de tração para a apreciação da Tensão Máxima, Força Máxima de Tração e Força Máxima de Ruptura. RESULTADOS: Nas três variáveis do estudo, os resultados indicam que, para os três momentos de avaliação (7, 14 e 28 dias) não houve diferença significativa entre os grupos óleo e controle. CONCLUSÃO: Para os testes mecânicos a que este estudo se propôs o óleo de Copaíba não se mostrou eficaz em aumentar a resistência da anatomose.

Efeito do ácido ascórbico e da hidrocortisona na cicatrização anastomótica intestinal / Effect of ascorbic acid and hidrocortisone on intestinal anastomotic tension

OBJETIVO: Comparar a resistência cicatricial de anastomoses jejunais em ratos, submetidos à administração de vitamina C e de hidrocortisona, em distintos períodos pós-operatórios. MÉTODOS: Foram estudados 40 ratos Wistar, submetidos à secção e subsequente anastomose término-terminal de segmento jejunal, a 10 cm da flexura duodenojejunal. Os animais foram distribuídos em quatro grupos (n=10): Grupo I - controle; Grupo II - administração de vitamina C oral 100 mg/kg; Grupo III - administração de hidrocortisona intraperitoneal 10 mg/kg; Grupo IV - administração de vitamina C mais hidrocortisona nas doses e vias de administração acima. Avaliaram-se as pressões de ruptura anastomótica no 5º e 21º dias do pós-operatório. RESULTADOS: Os ratos que receberam vitamina C isolada ou associada a hidrocortisona tenderam a ter pressão de ruptura maior do que os demais grupos, tanto no 5º quanto no 21º dia pós-operatório. CONCLUSÃO: A vitamina C contribui para aumentar a resistência das anastomoses jejunais dos ratos durante os primeiros cinco dias do pós-operatório. A resistência das anastomoses jejunais murinas foi pouco influenciada pela administração de corticóide intraperitoneal.

OBJECTIVE: The effects of vitamin C and hidrocortisone on anastomotic healing process are controversial. The objective of the present paper was to compare the jejunal anastomotic tension in different postoperative periods. METHODS: 40 male rats weighing 200 to 400 grams were submitted to laparotomy. The jejunum was transversally cut 10 cm from the duodenojejunal flexure, and subsequently anastomosed. The rats were divided into four groups (n=10). Group I - control, Group II - oral administration of vitamin C (100 mg/kg), Group III - intraperitoneal administration of hidrocortisone (10 mg/kg), and Group IV - administration of vitamin C and hidrocortisone at the above mentioned doses. The anastomotic resistance was determined by using bursting pressure test on the 5th and 21st postoperative days. RESULTS: The resistances of the groups with vitamin C, isolated or associated to hidrocortisone trend to be higher in both postoperative periods. However, the administration of intraperitoneal steroid did not change the resistance of murine jejunal anastomosis. CONCLUSION: The results of the present study suggest that vitamin C enhances the resistance of jejunal anastomosis in the rat.

The effect of prophylactic dose of a low molecular weight heparin on skin wound healing of rats / Efeito da dose profilática de heparina de baixo peso molecular na cicatrização de feridas na pele de ratos

PURPOSE: To investigate the effect of prophylactic dose of a low molecular weight heparin, enoxaparin, on skin wound healing of rats. METHODS: Forty rats were used for the study. Rats were randomly assigned to two equal groups. Experimental group received prophylactic dose of enoxaparin. Physiologic saline was administered to the control group. Parameters of wound healing of experimental and control groups were compared. For comparison of the groups in terms of fibrosis, vascularization, inflammation, epithelization, and tensile strength test (Newton). Mann-Whitney-U test was used because variables were categorical data (fibrosis, vascularization, inflammation and epithelization). Differences between groups were analyzed with independent samples t-test (tensile strength). Significance was set at p<0.05. RESULTS: Skin wound of the experimental group presented tensile strength significantly decreased (p<0.001), histopathologic examination revealed a significant (p<0.001) delayed epithelization and decreased in fibrosis, vascularization, inflammation (p<0.001) in the experimental group. CONCLUSION: Enoxaparin delay wound healing by decreased inflammatory cells, fibroblast contents and their products (growth factors), and by promoted hemorrhage.

OBJETIVO: Investigar o efeito de dose profilática da heparina de baixo peso molecular, enoxaparina, na cicatrização de feridas na pele de ratos. MÉTODOS: Quarenta ratos foram utilizados para o estudo. Ratos foram distribuídos aleatoriamente a dois grupos iguais. O grupo experimental recebeu profilática de enoxaparina. Solução salina fisiologica foi administrada ao grupo controle. Foram comparados parâmetros de cicatrização dos grupos experimental e controle.Os grupos foram comparados em termos de fibrose, vascularização, inflamação, epitelização e força tensil (teste de Newton). Foi realizado o teste de Mann-Whitney-U para variáveis com dados categóricos (fibrose, cicatrização, inflamação e epitelização). Diferenças entre os grupos foram analisadas como amostras independentes pelo t-teste (força tensil). Significância foi fixada para p < 0,05. RESULTADOS: A ferida do grupo experimental apresentou força tensil diminuída significativamente (p < 0,001), o exame histopatológico revelou um significativo (p < 0,001) retardo na epitelização e diminuição na fibrose, cicatrização, inflamação (p < 0,001) no grupo experimental. CONCLUSÃO: A enoxaparina retarda a cicatrização da ferida pela diminuição das células inflamatórias, pelo menor conteúdo de fibroblasto e seus produtos (fatores de crescimento) e por promover hemorragia. O grupo experimental foi incluído pela perda significativa da força tênsil no presente estudo.

Influence of chlorhexidine concentration on microtensile bond strength of contemporary adhesive systems

The purpose of this study was to investigate the influence of chlorhexidine (CHX) concentration on the microtensile bond strength (ìTBS) of contemporary adhesive systems. Eighty bovine central incisors were used in this study. The facial enamel surface of the crowns was abraded with 600-grit silicon carbide paper to expose flat, mid-coronal dentin surfaces. The tested materials were Scotchbond Multipurpose (SMP), Single-Bond (SB), Clearfil SE Bond (CSEB) and Clearfil Tri S Bond (CTSB). All the materials were applied according to manufacturer's instructions and followed by composite application (Z250). The teeth were randomly divided into 16 groups: for the etch-and-rinse adhesives (SMP and SB), 0.12 percent or 2 percent CHX was applied prior to or after the acid etching procedure. For the self-etch adhesives (CSEB and CTSB) 0.12 percent or 2 percent CHX was applied prior to the primer. Control groups for each one of the adhesive systems were also set up. The specimens were immediately submitted to ìTBS testing and the data were analyzed using Analysis of Variance and the Tukey post hoc test (alpha = .01). The failure patterns of the specimens were observed using scanning electron microscopy. The effects of 2 percent CHX were statistically significant (p < 0.01) for the self-etch adhesives but were not significant for the etch-and-rinse adhesive systems. Analysis of the data demonstrated no statistical difference between the etch-and-rinse adhesive systems. CHX-based cavity disinfectants in concentrations higher than 0.12 percent should be avoided prior to the self-etch adhesive systems evaluated in this study to diminish the possibilities of reduction in bond strength.

Analysis of the tensile strength on the healing of the abdominal wall of rats treated with infliximab / Análise da força tênsil na cicatrização da parede abdominal de ratos tratados com infliximabe

PURPOSE: To evaluate the effects of infliximab, a murine/human chimeric monoclonal antibody, on the tensile strength of abdominal wall surgical wounds. METHODS: Sixty Wistar healthy male rats with initial body weight between 215 and 390 g and 60 and 90 days of age were randomly assigned into two groups, E (Experimental) and C (Control) with 30 animals each. Group E animals received a single subcutaneous dose of 5mg/Kg of infliximab, and Group C animals received equivalent subcutaneous volume of a solution of 0.9 percent NaCl. After 48h, animals from both groups were submitted to a 4 cm median incision in the abdominal wall, including all layers that had been reconstituted with continuous suture of the aponeurotic muscle and skin, with 5.0 nylon thread. Then, Group E animals were separated by simple allotment into three subgroups named E3, E7 and E14 with ten animals each, and those from group C into C3, C7, C14 and were submitted, respectively, the reoperation and euthanasia at the third, seventh and fourteenth postoperative day. The anterior abdominal wall, which was resected during reoperation, was cut with No 15 scalpel lamina perpendicularly to the surgical wound. Each specimen, in the form of a 6 cm x 2 cm strip, was fixed by the extremity so that the suture line was equidistant from the fixation points of the dynamometer, in order to undergo the tensile strength test. The dynamometer, which was gauged for each series of measures, was calibrated to apply velocity to the 25 mm/min rupture test; the rupture value was expressed in N (Newton). Prior to euthanasia, the abdominal vena cava was identified and punctured in order to collect blood for TNF-α dosage. RESULTS: The mean tensile strength found for animals from subgroups E3, E7, E14, C3, C7, C14 were, respectively, 16.03, 18.69, 27.01, 28.40, 27.22, 29.15 and 24.30 N. In the results of the multiple comparisons tests, significant differences (p<0.05) was found between subgroups...

OBJETIVO: Avaliar os efeitos do infliximabe, anticorpo monoclonal quimérico humano-murino, sobre a força tênsil da ferida operatória abdominal. MÉTODOS: Sessenta ratos, linhagem Wistar, machos, sadios, com peso corporal inicial entre 215 e 390 g e 60 e 90 dias de vida foram distribuídos aleatoriamente em dois grupos, E (Experimental) e C (Controle) com 30 animais cada. Os animais do grupo E receberam por via subcutânea, dose única, de 5mg/Kg de infliximabe, via subcutânea e os animais do grupo C receberam, volume equivalente, de solução de NaCl a 0,9 por cento, via subcutânea. Depois de 48h os animais de ambos os grupos foram submetidos à incisão mediana na parede abdominal com 4 cm de extensão incluindo todos os planos que foram reconstituídos com sutura contínua músculo aponeurótica e pele, separadamente, com fio de nylon 5.0. A seguir os animais grupo E foram separados por sorteio simples em três subgrupos denominados E3, E7 e E14 com dez animais e os do grupo C em C3, C7 e C14 e foram submetidos, respectivamente, à reoperação e eutanásia no terceiro, sétimo e 14º dia pós-operatório. A parede abdominal anterior, ressecada dos animais durante a reoperação, foi cortada, com lamina de bisturi nº 15, perpendicularmente à ferida operatória. Cada espécime, em forma de fita, com 6 cm por 2 cm, foi preso pela extremidade de modo que a linha de sutura ficasse eqüidistante dos pontos de fixação do dinamômetro e realizado o teste de resistência tensil. O dinamômetro, aferido a cada série de medidas, foi calibrado para aplicar velocidade do teste de ruptura de 25 mm/min e o valor de ruptura foi expresso em N (Newtons) Antes da eutanásia a veia cava abdominal foi identificada e puncionada para retirada de sangue para dosagem de TNF-α. RESULTADOS: A média da força tensil encontrada para os animais dos subgrupos E3, E7, E14, C3, C7 e C14 foram, respectivamente, 16,03; 18,69; 27,01; 28,40; 27,22; 29,15 e 24,30 N. Nos resultados dos testes de...

Influence of nicotine on healing of vesical sutures in rabbits

PURPOSE: To study the effects of nicotine on inflammatory cells, deposition of collagen and its interference on the strength of tissue in vesical sutures in rabbits. METHODS: Twenty New Zealand rabbits were used, randomized into two groups: group N, consisting of 10 animals, to which nicotine was administered in the dose of 2mg/kg of weight as a subcutaneous injection, diluted in 1ml of saline solution at 0.9 percent in a daily administration during the 28 days prior to the surgery; and group C, consisting of 10 animals, to which saline solution at 0.9 percent was administered in the same conditions and time intervals of the nicotine group. All the animals underwent cystotomy and suture of the bladder wall 28 days after the administration of nicotine or saline solution. The measurements were performed on the fourth and seventh day in each group after cystectomy and euthanasia of the animals. A fragment of bladder was removed and sent for a tensile strength test to evaluate the tissue strength and another fragment underwent a histological analysis of inflammatory process and deposition of collagen. RESULTS: There was a decrease of neutrophils on the fourth postoperative day (p=0.079) and an increase of plasmocytes on the seventh postoperative day (p=0.053) in the animals that were given nicotine, without statistical difference in relation to the control group. In the analysis of the proliferation of fibroblasts, deposition of collagen and tensile strength test, there was no statistical difference in relation to the control group. CONCLUSION: The administration of nicotine in rabbits did not influence the healing process of vesical suture in relation to the inflammatory cells, deposit of collagen and tissue strength of the suture.

OBJETIVO: Estudar os efeitos da nicotina sobre as células inflamatórias, deposição de colágeno e sua interferência sobre a força tecidual em suturas vesicais de coelhos. MÉTODOS: Foram utilizados 20 coelhos Nova Zelândia, divididos de maneira aleatória em dois grupos: grupo N, composto de 10 animais, no qual foi administrada nicotina na dose de 2mg/Kg de peso por via subcutânea, diluída em 1ml de solução fisiológica a 0,9 por cento em 1 aplicação diária por 28 dias prévios à cirurgia; e grupo C, composto por 10 animais, no qual foi administrada solução fisiológica a 0,9 por cento nas mesmas condições e intervalos de tempo do grupo nicotina. Todos os animais foram submetidos à cistotomia com sutura da parede vesical após 28 dias da administração de nicotina ou solução fisiológica. As aferições foram realizadas no 4º e 7º dia em cada grupo após cistectomia e eutanásia dos animais. Uma parte da bexiga foi submetida a teste de tração para avaliar a força tecidual da sutura e outro fragmento foi submetido à análise histológica de processo inflamatório e deposição de colágeno. RESULTADOS: Houve uma diminuição de neutrófilos no 4º dia pós-operatório (p=0,079) e aumento de plasmócitos no 7º dia após a cirurgia (p=0,053) nos animais que receberam nicotina, sem diferença estatística em relação ao grupo controle. Na análise de proliferação de fibroblastos, deposição de colágeno e teste de tração tecidual, não houve diferença estatística em relação ao grupo controle. CONCLUSÃO: A administração de nicotina em coelhos não influenciou no processo de cicatrização de sutura vesicais em relação às células inflamatórias, depósito de colágeno e força tecidual da sutura.

Effects of enoxaparin on the healing of abdominal wall in rats: study on breaking strength and histopatology

OBJETIVO: Avaliar a influência da enoxaparina, sobre a cicatrização da parede abdominal. MÉTODOS: Foram utilizados 60 ratos Wistar, distribuídos aleatoriamente em grupo estudo (E) e controle (C). O grupo E recebeu 1 mg/kg de enoxaparina, via subcutânea, do pós-operatório imediato até o 7º dia pós-operatório (DPO); o grupo C doses-volume equivalentes de NaCl 0,9%. Os animais foram submetidos à laparotomia mediana e reoperados no 3º, 7º ou 14º DPO, para ressecção da parede abdominal anterior. A resistência tênsil foi testada e feita avaliação histopatológica. Análise estatística realizada com o teste U de Mann-Whitney, considerando significantes valores de p<0,05. RESULTADOS: A força tênsil de ruptura apresentou mediana de 0,64N para grupo C e de 0,41N para grupo E (p=0,60) no 3º DPO; de 2,27N para grupo C e de 4,32N para grupo E (p=0,01) no 7º DPO; de 5,72N para grupo C e de 6,62N para grupo E (p=0,97) no 14º DPO. Quanto ao estudo histopatológico, os resultados não obtiveram diferenças estatísticas significantes, exceto pela disposição do colágeno no 7º DPO, cujas medianas foram 2 no grupo C e 1 no grupo E (p= 0,007). CONCLUSÃO: Nas condições em que foi realizado o presente estudo, a enoxaparina provocou aumento da força tênsil de ruptura e pior disposição do colágeno no 7º DPO.

Extrato de Passiflora edulis na cicatrização de anastomose colônica em ratos: estudo morfológico e tensiométrico / Extract of Passiflora edulis in the healing of colonic anastomosis in rats: a tensiometric and morphologic study

INTRODUÇÃO: Pesquisas de novas substâncias com finalidades terapêuticas têm sido realizadas procurando isolar, extrair ou purificar novos compostos de origem vegetal. A Passiflora edulis (maracujá), espécie pertencente à família Passifloracea, originária das regiões tropicais e subtropicais do continente americano, é popularmente usada como sedativo, analgésico e antinflamatório e no tratamento de lesões cutâneas, feridas e erisipelas. OBJETIVO: Avaliar a cicatrização de anastomoses colônicas em ratos, que receberam extrato hidroalcoólico de Passiflora edulis no trans-operatório. MÉTODOS: Foram utilizados 40 ratos Wistar, distribuídos em dois grupos de 20 animais cada, denominados: grupo Passiflora (GP) e grupo controle (GC). Os ratos de cada grupo foram separados em dois subgrupos de 10 animais cada, avaliados no 3º e 7º dia do pós-operatório. O procedimento cirúrgico constou de secção da alça colônica esquerda, 5cm acima da reflexão peritoneal com preservação da arcada vascular e anastomose término-terminal em plano único. O grupo Passiflora recebeu dose única intraperitoneal do extrato hidroalcoólico de Passiflora edulis na dose de 250 mg/Kg. O grupo controle recebeu dose única de solução salina intraperitoneal em volume igual ao GP. Os parâmetros avaliados foram: aspectos macroscópicos da parede e cavidade abdominal, aderências perianastomóticas, pressão de ruptura à insuflação de ar, reação inflamatória tecidual da anastomose que constou de polimorfonucleares, monomorfonucleares e proliferação fibroblástica. RESULTADOS: Os aspectos macroscópicos não apresentaram diferenças significantes entre os grupos. Não ocorreu nenhuma deiscência de anastomose nos grupos estudados. Com relação à pressão de ruptura à insuflação de ar, observou-se que a média foi significantemente maior no subgrupo que recebeu o extrato de Passiflora no 3º dia (P3), cuja pressão foi 42,6 ± 17,8 mmHg em comparação ao subgrupo controle (C3), cuja pressão foi 25,4 ± 14,1 mmHg, p=0,028. O mesmo não ocorreu no 7º dia, onde o subgrupo C7 apresentou pressão de ruptura de 187,3 ± 39,5 mmHg, enquanto o subgrupo P7, apresentou pressão de ruptura de 203,0 ± 50,0 mmHg, p=0,447. Na análise histológica, os polimorfonucleares foram mais freqüentes no subgrupo C3, em comparação ao subgrupo P3, com diferença significante (p=0,034). Os monomorfonucleares (MMN) e proliferação fibroblástica foram mais freqüentes no subgrupo P3, com diferença significante, onde p=0,02 para MMN, e p=0,001 para proliferação fibroblástica. No 7º dia, houve diferença significante em todas as variáveis histológicas coradas pela hematoxilina-eosina e Tricômico de Masson (p<0,05) no subgrupo que recebeu o extrato de Passiflora. CONCLUSÃO: A administração peroperatória do extrato hidroalcoólico de Passiflora edulis influencia de forma significante na cicatrização das anastomoses colônicas em ratos.

INTRODUCTION: Investigation of new substances with therapeutic effects have been done trying to isolate, extract or purify new compounds of vegetable origin. The Passiflora edulis (maracujá) species from the Plassifloracia family, originated from the tropical and subtropical regions of the american continent, is found all over Brazil. It is commonly used as a sedative, painkiller and anti-inflammatory drug and also for the treatment of skin wounds, lesions and Erisipelae. PURPOSE: To evaluate the wound healing in colonic anastomosis in rats that received an hydro-alcoholic extract of Passiflora edulis peri-operatively. METHOD: 40 wistar rats were used distributed into two groups of 20 rats each, named: Passiflora edulis group (GP) and control group (GC). The rats of each group were separated into two subgroups of 10 animals each and were evaluated on the 3rd and 7th postoperative days. The surgical procedure consisted of a section of the left colon, 5 cm above the peritoneal reflexion with preservation of the vascular elements. Intestinal continuity was restored by an end-to-end single layer anastomosis. The Passiflora edulis group received an intraperitoneal application of the hydro-alcoholic extract in the dosage of 250 mg/kg. The control-group received one intraperitoneal dose of a saline with the same volume of the GP. The parameters evaluated were: macroscopic aspects of the wall and abdominal cavity, perianastomotic (adherences), bursting pressure, inflammatory tissue reaction on the anastomotic wound. RESULTS: The macroscopic aspects did not differ between the groups. No rupture in the anastomotic wound was seen in any rat. Regarding the bursting pressure, it was noticed that the average pressure was significantly higher in the subgroup that received the Passiflora edulis extract on the 3rd day (P3) (42,6 ± 17,8 mmHg vs. 25,4 ± 14,1 mmHg, p=0,028), as compared to the control sub-group (C3). However, on the 7th day, bursting pressure was similar in both groups (p=0.447). Rats from the C7 sub-group had a mean bursting pressure of 203,0 ± 50,0 mmHg vs. 187,3 ± 39,5 mmHg in the C7 sub-group. In the histologic analysis the polimorphic nuclear cells were more frequent in the C3 group, with significant differences (p=0,034). The monomorphic nuclear cells (MMN) and the fibrobastic proliferation were more frequent in the P3 sub-group with a significant difference, p=0,02 to MMN, and p=0,001 to the fibroblastic proliferation. On the 7th day there was a significant difference in all histologic criteria stained by hematoxin-eosin and Masson Trichomic (p<0,05) in the sub-group that received the Passiflora edulis extracts. CONCLUSION: The peri-operative administration of the hydro-alcoholic extract of Passiflora edulis has a positive influence on the healing of colonic anastomosis in rats.