Effect of hyperbaric oxygenation on random rat skin flaps vascularization.

PURPOSE: To evaluate the effect of hyperbaric oxygenation (HBO) on angiogenesis in random rat skin flaps, by immunoexpression of vascular endothelial growth factor A (VEGF-A). METHODS: Forty adult rats were divided into four groups: GE) epilated; GE/HBO) epilated subjected to HBO; GER) epilated submitted to dorsal skin flap; GER/HBO) epilated subjected to dorsal skin flap + HBO. HBO was performed with rats inside a chamber under atmosphere close to 100% oxygen and pressure of 2.4 absolute atmospheres, 2h per day during seven consecutive days. GE and GER groups were placed in the hyperbaric chamber without HBO. Then, under anesthesia, skin flaps were removed and separated into three portions relative to pedicle fixation. The samples were fixed in formalin and processed for paraffin embedding. Histological sections were submitted to immunohistochemistry for VEGF-A detection. The number of immunostained-blood vessels were counted under light microscopy. RESULTS: GE and GE/HBO groups showed normal and similar skin morphology in the three flap portions. A fibrin-leukocyte crust, along with denatured collagen and intense leukocyte infiltrate, was mainly observed in the dermis of the medial and distal flap portions of GER group. Meanwhile, the GER/HBO group presented more regions with intact collagen and small areas of leukocyte infiltrate in the three flap regions. VEGF-A-immunostained blood vessels were largely seen in all regions of GE and GE/HBO groups, whereas no significant differences were found between these groups. A decrease in vascularization was noticed in GER and GER/HBO groups, which was more evident in the most distal portion of the flaps. However, the number of VEGF-A-immunostained blood vessels in GER/HBO group was significantly higher when compared to GER group. CONCLUSIONS: Hyperbaric oxygenation was associated with increased angiogenesis and improved viability of rat skin flaps.

Effect of hyperbaric oxygenation on random rat skin flaps vascularization

ABSTRACT Purpose: To evaluate the effect of hyperbaric oxygenation (HBO) on angiogenesis in random rat skin flaps, by immunoexpression of vascular endothelial growth factor A (VEGF-A). Methods: Forty adult rats were divided into four groups: GE) epilated; GE/HBO) epilated subjected to HBO; GER) epilated submitted to dorsal skin flap; GER/HBO) epilated subjected to dorsal skin flap + HBO. HBO was performed with rats inside a chamber under atmosphere close to 100% oxygen and pressure of 2.4 absolute atmospheres, 2h per day during seven consecutive days. GE and GER groups were placed in the hyperbaric chamber without HBO. Then, under anesthesia, skin flaps were removed and separated into three portions relative to pedicle fixation. The samples were fixed in formalin and processed for paraffin embedding. Histological sections were submitted to immunohistochemistry for VEGF-A detection. The number of immunostained-blood vessels were counted under light microscopy. Results: GE and GE/HBO groups showed normal and similar skin morphology in the three flap portions. A fibrin-leukocyte crust, along with denatured collagen and intense leukocyte infiltrate, was mainly observed in the dermis of the medial and distal flap portions of GER group. Meanwhile, the GER/HBO group presented more regions with intact collagen and small areas of leukocyte infiltrate in the three flap regions. VEGF-A-immunostained blood vessels were largely seen in all regions of GE and GE/HBO groups, whereas no significant differences were found between these groups. A decrease in vascularization was noticed in GER and GER/HBO groups, which was more evident in the most distal portion of the flaps. However, the number of VEGF-A-immunostained blood vessels in GER/HBO group was significantly higher when compared to GER group. Conclusions: Hyperbaric oxygenation was associated with increased angiogenesis and improved viability of rat skin flaps.

Effect of hyperbaric oxygenation on the expression of glutathione peroxidase 4 and lactoperoxidase genes in the lung of isogenic mice after ischemia/reperfusion injury in the small bowel.

PURPOSE: To evaluate the effect of hyperbaric oxygenation (HBO) on the expression of the genes antioxidant glutathione peroxidase 4 (Gpx4) and lactoperoxidase (Lpo) in the lung of mice subjected to intestinal ischemia and reperfusion (IIR). METHODS: Control group (CG) in which were subjected to anesthesia, laparotomy and observation for 120 minutes; an ischemia and reperfusion group (IRG) subjected to anesthesia, laparotomy, small bowel ischemia for 60 minutes and reperfusion for 60 minutes; and three groups treated with HBO during ischemia (HBOG + I), during reperfusion (HBOG + R) and during ischemia and reperfusion (HBOG + IR). Studied 84 genes of oxidative stress by the method (RT-qPCR). Genes with expression levels three times below or above the threshold cycle were considered significantly hypoexpressed or hyperexpressed, respectively (Student's t-test p<0.05). RESULTS: Gpx4 and Lpo were hiperexpressed on IRG, showing a correlation with these genes with lung oxidative stress. Treated with HBO, there was a significant reduction on genic expression on HBOG+I. CONCLUSION: Hyperbaric oxygenation showed to be associated with decreased expression of these antioxidant genes, suggesting a beneficial effect on the mechanism of pulmonary oxidative stress whenever applied during the ischemia.

Effect of hyperbaric oxygenation on the expression of glutathione peroxidase 4 and lactoperoxidase genes in the lung of isogenic mice after ischemia/reperfusion injury in the small bowel

Abstract Purpose: To evaluate the effect of hyperbaric oxygenation (HBO) on the expression of the genes antioxidant glutathione peroxidase 4 (Gpx4) and lactoperoxidase (Lpo) in the lung of mice subjected to intestinal ischemia and reperfusion (IIR). Methods: Control group (CG) in which were subjected to anesthesia, laparotomy and observation for 120 minutes; an ischemia and reperfusion group (IRG) subjected to anesthesia, laparotomy, small bowel ischemia for 60 minutes and reperfusion for 60 minutes; and three groups treated with HBO during ischemia (HBOG + I), during reperfusion (HBOG + R) and during ischemia and reperfusion (HBOG + IR). Studied 84 genes of oxidative stress by the method (RT-qPCR). Genes with expression levels three times below or above the threshold cycle were considered significantly hypoexpressed or hyperexpressed, respectively (Student's t-test p<0.05). Results: Gpx4 and Lpo were hiperexpressed on IRG, showing a correlation with these genes with lung oxidative stress. Treated with HBO, there was a significant reduction on genic expression on HBOG+I. Conclusion: Hyperbaric oxygenation showed to be associated with decreased expression of these antioxidant genes, suggesting a beneficial effect on the mechanism of pulmonary oxidative stress whenever applied during the ischemia.

Hyperbaric oxygenation and the genic expression related to oxidative stress in the heart of mice during intestinal ischemia and reperfusion.

PURPOSE: To investigate the effects of hyperbaric oxygenation (HBO) on intestinal ischemia and reperfusion (IR) injury, we evaluated the expression of 84 genes related to oxidative stress and the antioxidant response in mouse hearts. METHODS: Four groups were subjected to 60 minutes of intestinal ischemia followed by 60 minutes of reperfusion: IRG, ischemia and reperfusion group without HBO; HBO-IG, which received HBO during ischemia; HBO-RG, which received HBO during reperfusion; and HBO-IRG, which received HBO during ischemia and reperfusion. The control group (CG) underwent anesthesia and laparotomy and was observed for 120 minutes. The (RT-qPCR) method was applied. Genes with expression levels three times below or above the threshold cycle were considered significantly hypoexpressed or hyperexpressed, respectively (Student's t-test p<0.05). RESULTS: Eight genes (9.52%) were hyperexpressed in the IRG. When the HBO groups were compared to the IRG, we found a decrease in the expression of eight genes in the HBO-IG, five genes in the HBO-RG, and seven genes in the HBO-IRG. CONCLUSION: The reduction in the expression of genes related to oxidative stress and antioxidant defense following HBO in mouse hearts resulting from intestinal IR injury was more favorable during the ischemic period than during the reperfusion period.

Hyperbaric oxygenation and the genic expression related to oxidative stress in the heart of mice during intestinal ischemia and reperfusion

Abstract Purpose: To investigate the effects of hyperbaric oxygenation (HBO) on intestinal ischemia and reperfusion (IR) injury, we evaluated the expression of 84 genes related to oxidative stress and the antioxidant response in mouse hearts. Methods: Four groups were subjected to 60 minutes of intestinal ischemia followed by 60 minutes of reperfusion: IRG, ischemia and reperfusion group without HBO; HBO-IG, which received HBO during ischemia; HBO-RG, which received HBO during reperfusion; and HBO-IRG, which received HBO during ischemia and reperfusion. The control group (CG) underwent anesthesia and laparotomy and was observed for 120 minutes. The (RT-qPCR) method was applied. Genes with expression levels three times below or above the threshold cycle were considered significantly hypoexpressed or hyperexpressed, respectively (Student's t-test p<0.05). Results: Eight genes (9.52%) were hyperexpressed in the IRG. When the HBO groups were compared to the IRG, we found a decrease in the expression of eight genes in the HBO-IG, five genes in the HBO-RG, and seven genes in the HBO-IRG. Conclusion: The reduction in the expression of genes related to oxidative stress and antioxidant defense following HBO in mouse hearts resulting from intestinal IR injury was more favorable during the ischemic period than during the reperfusion period.

Action of hyperbaric oxygenation in the rat skin flap.

PURPOSE: To evaluate the morphology, necrotic area and collagen content in skin flaps of rats subjected to hyperbaric oxygenation (HBO). METHODS: Forty adult rats were divided into four groups: GEC - epilated; GE/HBO - epilated subjected to HBO; GER - epilated submitted to skin flap (2 cm in width /8 cm length in the dorsal area) and GER/HBO - epilated, subjected to skin flap and HBO. HBO (2.4 ATA) was performed for two hours during seven consecutive days. In the eighth day, the rats were anesthetized and the skin flaps were removed and separated into three portions, relative to pedicle fixation. The material fixed in 10% formalin was processed for paraffin embedding; sections were stained by H.E and subjected to picrosirius-red method. The slides examined under light microscopy for evaluation of the collagen content in polarized light microscope and ImageLab(r) software (Bio-Rad). RESULTS: The data showed larger area of necrosis and lower levels of collagen in the three regions of the GER group, whereas in the GER/HBO group the collagen content was similar to the GEC and GE/HBO groups. CONCLUSION: Hyperbaric oxygenation reduced the area of necrosis and preserved the morphology and collagen content in skin flaps of rats.

Action of hyperbaric oxygenation in the rat skin flap

PURPOSE: To evaluate the morphology, necrotic area and collagen content in skin flaps of rats subjected to hyperbaric oxygenation (HBO). METHODS: Forty adult rats were divided into four groups: GEC - epilated; GE/HBO - epilated subjected to HBO; GER - epilated submitted to skin flap (2 cm in width /8 cm length in the dorsal area) and GER/HBO - epilated, subjected to skin flap and HBO. HBO (2.4 ATA) was performed for two hours during seven consecutive days. In the eighth day, the rats were anesthetized and the skin flaps were removed and separated into three portions, relative to pedicle fixation. The material fixed in 10% formalin was processed for paraffin embedding; sections were stained by H.E and subjected to picrosirius-red method. The slides examined under light microscopy for evaluation of the collagen content in polarized light microscope and ImageLab(r) software (Bio-Rad). RESULTS: The data showed larger area of necrosis and lower levels of collagen in the three regions of the GER group, whereas in the GER/HBO group the collagen content was similar to the GEC and GE/HBO groups. CONCLUSION: Hyperbaric oxygenation reduced the area of necrosis and preserved the morphology and collagen content in skin flaps of rats. .

The effects of hyperbaric oxygen therapy upon ototoxic injuries produced by amikacin in guinea pigs.

UNLABELLED: Hyperbaric oxygen therapy (HBOT) has enhanced the prevention and treatment of auditory ailments such as ototoxicity. OBJECTIVE: To study the effects of HBOT upon ototoxic injuries produced by amikacin. METHOD: This experimental study included 12 albino guinea pigs, whose auditory function was assessed through distortion product otoacoustic emissions (DPOAEs) and brainstem auditory evoked potentials (BAEPs) before and after the administration of amikacin (600 mg/kg/day) and HBOT sessions (2 ATA, 60 minutes). Morphological features were analyzed through scanning electron microscopy. Subjects were divided into four groups, as follows: group 1 - saline solution + HBOT; group 2 - amikacin for 8 days; group 3 - amikacin + seven days of rest; and group 4 - amikacin + HBOT. RESULTS: Group 1 subjects had preserved function and morphology throughout the experiment; Group 2 subjects had statistically significant levels of hair cell injury and functional impairment; Subjects on groups 3 and 4 had statistically significant functional and morphological impairment after the administration of amikacin, which were still present after the proposed procedures had been carried out. CONCLUSION: Hyperbaric oxygen therapy did not change the cochlear hair cell morphology or the electro-physiological thresholds of the guinea pigs given amikacin.

Existe efeito protetor da oxigenação hiperbárica em retalhos cutâneos randômicos?: um estudo imuno-histoquímico de apoptose celular e fator de crescimento vascular endotelial / Does hyperbaric oxygenation have a protective effect on random skin flaps? An immunohistochemical study of cellular apoptosis and vascular endothelial growth factor

INTRODUÇÃO: A oxigenação hiperbárica (OHB) tem por objetivo aumentar em pelo menos 10 vezes a pressão tecidual de oxigênio, diminuindo os efeitos deletérios da isquemia. O objetivo deste estudo é investigar o papel da oxigenação hiperbárica na expressão imuno-histoquímica da caspase 3 e do fator de crescimento endotelial vascular (VEGF) em retalhos randômicos em ratos. MÉTODO: Trinta e dois ratos Wistar machos foram divididos aleatoriamente em quatro grupos: grupo sham (GS), grupo N-acetilcisteína (GNAC), grupo OHB (GOHB) e grupo OHB + N-acetilcisteína (GHN). Um retalho de pele retangular (2 cm x 8 cm) foi dissecado a partir da camada muscular dorsal, preservando um pedículo cranial. Uma lâmina de polietileno foi colocada sobre a camada muscular e fixou-se o retalho no local original. No 8º dia, foram coletadas biópsias (2 cm x 1 cm) de espessura total das áreas proximal, média e cranial e de um local fora do retalho, que serviu como área de controle. RESULTADOS: A expressão de VEGF nas camadas da pele e nos vasos não apresentou diferenças significativas entre os grupos. As células apoptóticas estavam significativamente aumentadas na área central do retalho em todos os grupos. O maior aumento ocorreu nos grupos GS e GNAC. A OHB diminuiu significativamente o número de células caspase 3 positivas nas camadas da pele e nos vasos das três áreas. CONCLUSÕES: A OHB foi associada a expressão reduzida de apoptose. A expressão de VEGF em camadas da pele e vasos não demonstrou diferença significativa. Os resultados sugerem que a difusão do oxigênio através do espaço intersticial foi o fator determinante para os resultados mais favoráveis da OHB na diminuição da expressão de apoptose.

BACKGROUND: Hyperbaric oxygenation (HBO) therapy aims to increase oxygen tissue pressure by at least 10 times and decrease the adverse effects of ischemia. The aim of this study was to investigate the effect of HBO on the immunohistochemical expressions of caspase 3 and vascular endothelial growth factor (VEGF) in random flaps in rats. METHODS: Thirty-two male Wistar rats were randomly divided into 4 groups: the sham group (GS), the N-acetylcysteine group (GNAC), the HBO group, and the HBO + N-acetylcysteine group. A rectangular skin flap (2 × 8 cm) was dissected from the dorsal muscle layer, and a cranial pedicle was preserved. A polyethylene film was placed on the muscle layer, and the flap was fixed in the original site. On the eighth day, biopsy samples (2 × 1 cm) of the entire thickness of the proximal, medial, and cranial areas as well as of the site outside the flap, which was used as a control, were collected. RESULTS: VEGF expression in the skin layers and vessels was not significantly different between the groups. The number of apoptotic cells was significantly increased in the area of the flap in all groups. The highest increase was noted in the GS and GNAC groups. HBO significantly reduced the number of caspase 3-positive cells in the skin layers and vessels of the 3 areas. CONCLUSIONS: HBO was associated with decreased apoptosis. VEGF expression in the skin layers and vessels did not differ significantly. The results suggest that oxygen diffusion through the interstitial space was the determining factor for the positive effect of HBO on the decrease in apoptosis.

Efeito da oxigenação hiperbárica em lesão ototóxica produzida pela amicacina em cobaias / The effects of hyperbaric oxygen therapy upon ototoxic injuries produced by amikacin in guinea pigs

A oxigenação hiperbárica têm favorecido a prevenção e o tratamento de afecções auditivas como a ototoxicidade. OBJETIVO: Estudar os efeitos da oxigenação hiperbárica em lesão ototóxica promovida pela amicacina. Forma de estudo: Experimental. MÉTODO: Avaliados aspectos funcionais de 12 cobaias albinas por meio das emissões otoacústicas produtos de distorção e do potencial evocado auditivo de tronco encefálico, antes e após o uso de amicacina (600 mg/kg/dia) e das sessões com oxigenação hiperbárica (2 ATA, 60 minutos). Aspectos morfológicos foram avaliados por meio de microscopia eletrônica de varredura. Grupos de estudo com três animais: grupo 1 - solução salina + oxigenação hiperbárica; grupo 2 - amicacina 8 dias; grupo 3 - amicacina + 7 dias de repouso e grupo 4 - amicacina + oxigenação hiperbárica. RESULTADOS: Grupo 1 apresentou preservação da funcionalidade e da morfologia durante todo experimento. Grupo 2 demonstrou, ao final do experimento, lesões estatisticamente significantes das células ciliadas com alterações funcionais. Grupos 3 e 4 apresentaram alterações estatisticamente significantes dos aspectos funcionais e morfológicos após o uso da amicacina, mantendo estas alterações após os procedimentos propostos. CONCLUSÃO: A oxigenação hiperbárica não promoveu alterações na morfologia das células ciliadas da cóclea e aos limiares eletrofisiológicos das cobaias submetidas à amicacina.

Hyperbaric oxygen therapy (HBOT) has enhanced the prevention and treatment of auditory ailments such as ototoxicity. OBJECTIVE: To study the effects of HBOT upon ototoxic injuries produced by amikacin. METHOD: This experimental study included 12 albino guinea pigs, whose auditory function was assessed through distortion product otoacoustic emissions (DPOAEs) and brainstem auditory evoked potentials (BAEPs) before and after the administration of amikacin (600 mg/kg/day) and HBOT sessions (2 ATA, 60 minutes). Morphological features were analyzed through scanning electron microscopy. Subjects were divided into four groups, as follows: group 1 - saline solution + HBOT; group 2 - amikacin for 8 days; group 3 - amikacin + seven days of rest; and group 4 - amikacin + HBOT. RESULTS: Group 1 subjects had preserved function and morphology throughout the experiment; Group 2 subjects had statistically significant levels of hair cell injury and functional impairment; Subjects on groups 3 and 4 had statistically significant functional and morphological impairment after the administration of amikacin, which were still present after the proposed procedures had been carried out. CONCLUSION: Hyperbaric oxygen therapy did not change the cochlear hair cell morphology or the electro-physiological thresholds of the guinea pigs given amikacin.

Efeito da oxigenação hiperbárica e da N-acetilcisteína na viabilidade de retalhos cutâneos em ratos / Effects of hyperbaric oxygenation and N-acetylcysteine on the survival of random-pattern skin flaps in rats

INTRODUÇÃO: Os avanços das técnicas em cirurgia plástica permitiram a reconstrução de extensos defeitos causados por ferimentos, entre as quais destaca-se a utilização dos retalhos randômicos. No entanto, o fator limitante para a utilização desses retalhos é a imprevisibilidade de sua vascularização distal, o que poderá ocasionar danos irreversíveis à microcirculação, resultando em necrose parcial ou completa do retalho, tornando a ferida mais suscetível a infecção. Portanto, melhorar a viabilidade do retalho randômico, principalmente em sua extremidade distal, tem sido uma meta importante para o sucesso dessa técnica. O objetivo deste estudo foi investigar o papel da oxigenação hiperbárica (OHB), da N-acetilcisteína (NAC) e da associação de ambas (OHB + NAC) na área de necrose em retalhos randômicos modificados de McFarlane em pele de ratos Wistar. MÉTODO: No total, 32 ratos Wistar machos foram divididos aleatoriamente em grupo Sham (GS, n = 8), grupo N-acetilcisteína (GNAC, n = 8), grupo oxigênio hiperbárico (GOHB, n = 8) e grupo oxigênio hiperbárico + N-acetilcisteína (GHN, n = 8). Sob anestesia geral, foi executado um retalho randômico modificado de McFarlane na região dorsal dos ratos. RESULTADOS: A necrose média foi de 18,3 por cento, 24,3 por cento, 12,6 por cento e 14,9 por cento, respectivamente, nos grupos GS, GNAC, GOHB e GHN. Os grupos GOHB e GHN apresentaram diferença significativa quando comparados ao grupo GNAC. CONCLUSÕES: A OHB está associada a redução da área de necrose do retalho cutâneo. A NAC foi associada a maus resultados quando usada isoladamente. A associação dos dois procedimentos, OHB e NAC, não potencializou os resultados favoráveis observados com o uso da OHB isoladamente. As descobertas sugerem que a difusão de oxigênio através do espaço intersticial foi o fator determinante de resultados mais favoráveis da OHB.

BACKGROUND: Advances in plastic surgery techniques have enabled reconstruction of extensive wound damage, especially through the use of random flaps. However, the limiting factor for the use of these flaps is the unpredictable blood supply, which may produce irreversible damage to the microcirculation and result in partial or complete flap necrosis, making the wound more susceptible to infection. Therefore, improvement of random flaps, especially in the distal extremity, has been an essential goal for the success of this technique. The objective of this study was to investigate the effects of hyperbaric oxygenation (HBO), N-acetylcysteine (NAC), and the combination of both (HBO + NAC) on the degree of necrosis in modified McFarlane random skin flaps on Wistar rats. METHODS: A total of 32 male Wistar rats were randomly divided into a sham treatment group (SG, n = 8), N-acetylcysteine group (NACG, n = 8), hyperbaric oxygenation group (HBOG, n = 8), and hyperbaric oxygenation plus N-acetylcysteine group (HNG, n = 8). Modified McFarlane random flaps were created in the dorsal region of the rats. RESULTS: The average area of the flaps exhibiting necrosis was 18.3 percent, 24.3 percent, 12.6 percent, and 14.9 percent, in the SG, NACG, HBOG, and HNG, respectively. The necrotic areas in the HBOG and HNG were significantly smaller than that in the NACG. CONCLUSIONS: HBO treatment was associated with a reduction in the area of necrosis in the skin flaps. NAC treatment alone gave poor results. The use of HBO and NAC in combination did not improve the outcome compared with the use of HBO alone. The findings suggest that oxygen diffusion through the interstitial space was the factor responsible for the favorable results of HBO.

Immunohistochemical expression of apoptosis and VEGF expression on random skin flaps in rats treated with hyperbaric oxygen and N-acetylcysteine.

OBJECTIVE: We sought to investigate the role of hyperbaric oxygen (HBO2), N-acetylcysteine (NAC), and HBO2 plus NAC (HN) on the immunohistochemical expression of caspase-3 and the vascular endothelial growing factor (VEGF) on random skin flaps of rats (modified McFarlane design). METHODS: Thirty-two male Wistar rats were randomly divided into four groups: GS (sham--n = 8); GNAC (N-acetylcysteine--n = 8); GHBO2 (hyperbaric oxygen--n = 8); and GHN (HBO2 plus NAC--n = 8). A rectangular skin flap (2 x 8 cm2) was dissected from the muscular dorsal layer, preserving a cranial pedicle. Polyethylene film was placed over the muscular layer, and an interrupted 3.0 nylon suture fixed the flap into the original place. On the eighth day, full-thickness biopsies (2 x 1 cm2) were collected from the proximal, middle and cranial areas of the skin flap, and in a site away from the flap labeled the control area. RESULTS: The expression of VEGF in the skin layers (epidermis, dermis, subcutaneous muscles) and vessels showed no significant difference among the groups. Apoptotic cells were significantly increased in the middle area of the flap in all groups. The major increase occurred in GS and GNAC. HBO2 significantly decreased cleaved caspase-3-positive cell numbers in the skin layers and vessels of the three areas. CONCLUSIONS: HBO2 showed a protective effect in the ischemic skin flap that was associated with reduced expression of apoptosis. GNAC and GHN were not associated with lower expression of apoptosis, and poor results were observed in GNAC. The combination of NAC and HBO2 did not show better results than using them separately. The expression of VEGF in skin layers and vessels did not show a significant difference in our modified McFarlane flap model. The results suggest that the diffusion of oxygen through the interstitial space was the determining factor for the more favorable results of HBO2 in the decrease of apoptosis expression.

The effect of liposome-delivered prednisolone on collagen density, myofibroblasts, and fibrous capsule thickness around silicone breast implants in rats.

Capsular contracture is a potential adverse effect of breast implants. An inflammatory reaction is most likely the origin of fibrosis around the implant. It is possible that some substances may act to prevent this inflammatory reaction. Thus, our goal was to evaluate the effectiveness of local depot prednisolone phosphate-liposomes (PPL) on fibrous capsule formation around textured silicone breast implants. Shell prostheses (2 mL) were implanted in the right (plus PPL group) and left (plus saline solution, saline group) subcutaneous dorsum of 18 rats. In another 18 rats, the implants were positioned in the left of the back without any drug instillation (control group). In the PPL group, the capsule thickness (microm) and density (%) of collagen were significantly (p<0.0001) lower compared with the control group on days 35 and 90 postsurgery. Furthermore, in the PPL group, a significant reduction in myofibroblast count was observed on day 90 postsurgery (p<0.0001). In conclusion, a single dose of depot liposome-delivered prednisolone was effective at impairing capsule formation around the silicone implant. The results suggest a strong local and weak systemic effect of PPL on the fibrous tissue around silicone implants. To our knowledge, no study has yet assessed the effect of PPL on silicone breast implants.

Fibrin adhesive and the vaginal vault synthesis on female rabbits abdominal hysterectomies / Adesivo de fibrina e a síntese da cúpula vaginal após histerectomia abdominal em coelhos fêmeas

PURPOSE: To investigate the effectiveness of fibrin glue in comparison with polyglycolic acid suture to promote the closure of rabbit's vaginal vault, after abdominal hysterectomy. METHODS: Twenty female, adults, New Zealand rabbits, were submitted to abdominal hysterectomy and randomly distributed to polyglycolic acid suture (G-PA / n=10) or fibrin glue closure of vaginal vault (G-FG / n=10). Radiograph study allowed identifying vault vaginal suture disrupter or fistulas to urinary bladder or rectum. Videovaginoscopy study allowed identifying the presence of cellulites, abscess formation, tissue granulation or granuloma. Vaginal cuff burst test allowed to identify by the escape of air bubbles and rupture pression record. Histological sections stained with Picrosirius red allowed the measure of fibrous tissue healing. RESULTS: The videovaginoscopy identified a significant difference (Fisher Test p<0.3142) of granulation tissue in the animals of G-PA (40 percent) in comparison with the G-FG (20 percent). The gross inspection showed the same relation in the granulation tissue occurrence (Fisher test p< 0.1749) with G-PA (50 percent) and G-FB (20 percent). The visceral adhesion to the vaginal vault wound was statistical significant (Fisher test p< 0.1749) with G-PA (50 percent) and G-FG (20 percent). The pressure of rupture (mm Hg) of the burst test was similar (p<0.0421) in the animals of G-PA (61.5±19.3) and G-FG (72.5±21.9). The collagen matrix of vault wound healing was similar (p< 0.0231) between the G-PA (31.63±15) and the G-FG (23.2±13.2). CONCLUSION: The vaginal vault closure using the fibrin glue is a safe and reliable procedure after abdominal hysterectomy in female rabbit model.

OBJETIVO: Investigar a eficácia da cola de fibrina e da sutura usando fio de ácido poliglicólico para promover o fechamento da cúpula vaginal de coelhas, após histerectomia abdominal. MÉTODOS: Vinte coelhos fêmeas, New Zealand, adultas foram submetidas à histerectomia abdominal e distribuídas para sutura da cúpula vaginal com fio de ácido poliglicólico (G-PA / n=10) ou cola de fibrina (G-FG / n=10). Estudo radiológico foi realizado para identificar deiscências ou fístulas vesicais ou retais. Videovaginoscopia foi realizada para identificar a presença de secreções, abscessos, tecido de granulação ou granuloma tipo corpo estranho. Teste in vitro de pressão de rompimento sob selo d'água foi realizado para identificar a perviedade da sutura. O tecido de cicatrização foi estudado pela coloração com picrosirius red para mensuração do tecido fibrótico. RESULTADOS: A videovaginoscopia mostrou uma diferença significante (Teste de Fisher p<0,3142) no tecido de granulação do grupo G-PA (40 por cento) em comparação com o grupo G-FG (20 por cento). A análise macroscópica mostrou a mesma relação com o tecido de granulação (Teste de Fisher p< 0.1749) com G-PA (50 por cento) e G-FB (20 por cento). A aderência visceral à cúpula vaginal foi estatisticamente significativa (Teste de Fisher p< 0.1749) com o G-PA (50 por cento) e G-FG (20 por cento). A pressão de rompimento (mmHg) foi similar (p<0.0421) nos animais do grupo G-PA (61.5±19.3) e G-FG (72.5±21.9). A matriz colagenosa do tecido de cicatrização teve resultados semelhantes (p< 0.0231) entre G-PA (31.63±15) e G-FG (23.2±13.2). CONCLUSÃO: O fechamento da cúpula vaginal usando cola de fibrina é um procedimento seguro e confiável após histerectomia abdominal em coelhos fêmeas.

Fibrin adhesive and the vaginal vault synthesis on female rabbits abdominal hysterectomies.

PURPOSE: To investigate the effectiveness of fibrin glue in comparison with polyglycolic acid suture to promote the closure of rabbit's vaginal vault, after abdominal hysterectomy. METHODS: Twenty female, adults, New Zealand rabbits, were submitted to abdominal hysterectomy and randomly distributed to polyglycolic acid suture (G-PA / n=10) or fibrin glue closure of vaginal vault (G-FG / n=10). Radiograph study allowed identifying vault vaginal suture disrupter or fistulas to urinary bladder or rectum. Videovaginoscopy study allowed identifying the presence of cellulites, abscess formation, tissue granulation or granuloma. Vaginal cuff burst test allowed to identify by the escape of air bubbles and rupture pression record. Histological sections stained with Picrosirius red allowed the measure of fibrous tissue healing. RESULTS: The videovaginoscopy identified a significant difference (Fisher Test p<0.3142) of granulation tissue in the animals of G-PA (40%) in comparison with the G-FG (20%). The gross inspection showed the same relation in the granulation tissue occurrence (Fisher test p< 0.1749) with G-PA (50%) and G-FB (20%). The visceral adhesion to the vaginal vault wound was statistical significant (Fisher test p< 0.1749) with G-PA (50%) and G-FG (20%). The pressure of rupture (mm Hg) of the burst test was similar (p<0.0421) in the animals of G-PA (61.5+/-19.3) and G-FG (72.5+/-21.9). The collagen matrix of vault wound healing was similar (p< 0.0231) between the G-PA (31.63+/-15) and the G-FG (23.2+/-13.2). CONCLUSION: The vaginal vault closure using the fibrin glue is a safe and reliable procedure after abdominal hysterectomy in female rabbit model.

A proposal of multiplace hyperbaric chamber for animal experimentation and veterinary use / Uma proposta de câmara hiperbárica para uso em animal de experimentação e uso veterinário

PURPOSE: To develop a project of hyperbaric chamber that allows its safe and reliable use in veterinary and animal experimentation. METHODS: Based on the technical specifications for the construction of hyperbaric chambers for human beings, it has been developed a design of a chamber with dimensions and characteristics for the use of a midsize animal, (dog or pig), as well as a multiple chamber for the use in small animals (mice, rats, hamsters, rabbits or cats). The technical specifications allowed that the chamber could be used both for veterinary use and for use in experiments on Health Sciences. RESULTS: A chamber with the following characteristics was built: ASTM A36 steel for the manufacture of the master cylinder and rear cover; front door built in 5052 aluminum; internal diameter of 50.5 cm and 83.0 cm in length; weight 160Kg and internal area of 150cm³; internal space to accommodate 2 acrylic baskets; 150mm high, 280mm wide and 690mm in length. It was capable of supporting a maximum of hydrostatic pressure test of 3.0 to 4.0 BAR ACT and maximum working pressure of 2.0 BAR or 3.0 ACT; equipped with security devices and valves that triggers with load of 2.2 BAR or 3.2 ACT. Tests for engineering and biological use on animals showed the effectiveness of the device. CONCLUSION: The development of the project enabled the construction of a hyperbaric chamber with security features and reliability comparable to those required by the legal and technical specifications of a hyperbaric chamber human use.

OBJETIVO: Desenvolver um projeto de câmara hiperbárica que permita o seu uso seguro e confiável em veterinária e em animais de experimentação de pequeno e médio porte. MÉTODOS: Baseados em especificações técnicas de construção de câmaras hiperbáricas de seres humanos, foi desenvolvido uma adaptação de projeto de uma câmara com dimensões e características para uso em animal de médio porte (cão ou porco), assim como câmara múltipla para animais de pequeno porte (camundongos, ratos, hamsters, coelhos ou gatos). O atendimento às especificações técnicas deve permitir a sua utilização tanto para uso veterinário quanto para uso em experimentação em Ciências da Saúde. RESULTADOS: Uma câmara com as seguintes características foi construída: aço ASTM A36 para a confecção do cilindro principal e tampo traseiro, tampo frontal (porta) construído em alumínio 5052, diâmetro interno de 50,5cm e 83,0cm de comprimento; peso de 160Kg e espaço interno de 150cm³; espaço para acomodar 2 cestas de acrílico de 150mm de altura, 280mm de largura e 690mm de comprimento; capacidade para suportar um máximo de pressão hidrostática teste de 3,0BAR ou 4,0 ACT e uma pressão máxima de trabalho de 2,0 BAR ou 3,0 ACT; equipado com dispositivos e válvulas de segurança que disparam com carga de 2,2 BAR ou 3,2 ACT. Os testes de engenharia e de uso biológico com animais mostraram a efetividade do equipamento. CONCLUSÃO: O desenvolvimento do projeto permitiu a confecção de uma câmara hiperbárica com características de segurança e confiabilidade comparável às exigidas pelas especificações técnicas e legais de uma câmara para tratamento hiperbárico.

A proposal of multiplace hyperbaric chamber for animal experimentation and veterinary use.

PURPOSE: To develop a project of hyperbaric chamber that allows its safe and reliable use in veterinary and animal experimentation. METHODS: Based on the technical specifications for the construction of hyperbaric chambers for human beings, it has been developed a design of a chamber with dimensions and characteristics for the use of a midsize animal, (dog or pig), as well as a multiple chamber for the use in small animals (mice, rats, hamsters, rabbits or cats). The technical specifications allowed that the chamber could be used both for veterinary use and for use in experiments on Health Sciences. RESULTS: A chamber with the following characteristics was built: ASTM A36 steel for the manufacture of the master cylinder and rear cover; front door built in 5052 aluminum; internal diameter of 50.5 cm and 83.0 cm in length; weight 160Kg and internal area of 150cm(3); internal space to accommodate 2 acrylic baskets; 150mm high, 280mm wide and 690mm in length. It was capable of supporting a maximum of hydrostatic pressure test of 3.0 to 4.0 BAR ACT and maximum working pressure of 2.0 BAR or 3.0 ACT; equipped with security devices and valves that triggers with load of 2.2 BAR or 3.2 ACT. Tests for engineering and biological use on animals showed the effectiveness of the device. CONCLUSION: The development of the project enabled the construction of a hyperbaric chamber with security features and reliability comparable to those required by the legal and technical specifications of a hyperbaric chamber human use.

A preservação do intestino delgado para transplante: a contribuição da oxigenação hiperbárica / Small bowel preservation for transplantation: the contribution of the hyperbaric oxygenation

RACIONAL: Não há ainda um método que mantenha adequadamente e por tempo prolongado a qualidade e a função do intestino delgado a ser transplantado, apesar da existência de várias modalidades de preservação. Há necessidade de se desenvolver e aprimorar novas opções técnicas. OBJETIVO: Recuperar os artigos que estudaram a aplicação da oxigenação hiperbárica (OHB) como técnica de preservação do intestino delgado destinado para transplante, procurando determinar qual a contribuição do método no prolongamento do tempo e qualidade dessa preservação. MÉTODOS: Utilizou-se a base de dados do Medline e da Scielo consultada nos sites www.pubmed.com e www.bireme.br tendo sido selecionados 58 trabalhos pertinentes. A revisão mostrou que a preservação intestinal está associada ao uso de soluções que fornecem substrato oxidativo para a célula assim como acrescentam substâncias que evitam ou reduzem a formação de espécies reativas de oxigênio. A hipotermia e a oxigenação destas soluções preservadoras é de uso corrente e consensual. Nove trabalhos ativeram-se ao uso específico da OHB. Não há consenso sobre sua utilização em trabalhos experimentais. Contudo os estudos não são comparáveis, pois utilizam metodologias diversas e diferentes tipos de avaliação. Discute-se também a complexidade e os custos da OHB. Apesar disto, há indicações que a OHB pode prevenir o edema da hipotermia, manter a oxigenação tecidual durante a preservação e impedir ou diminuir a formação de radicais livres. CONCLUSÃO: A OHB deve ser avaliada como alternativa exclusiva ou complementar às técnicas de preservação, sendo campo fértil de investigação.

INTRODUCTION: In spite of the existence of several modalities of preservation, up to now a method that adequately keeps for a long time the quality and the functioning aspects of the small bowel to be transplanted is lacking. AIM: To gather articles using hyper baric oxygenation (HBO) as technique of small bowel preservation for transplant and quality of the preservation. METHODS: Database Medline and Scielo were checked at www.pubmed.com and www.bireme.br, with 58 works selected. Solutions supplying oxidative substratum to the cells and adding substances to prevent or reduce the formation of reactive oxygen, is the main source of preservation. The hypothermia and solutions oxygenation are in current use. Nine papers studied the specific use of the HBO. There is no consensus on its use in experimental works. However, these papers are not comparable, due to different methodologies and types of evaluation. One also argues the complexity and the costs of the HBO. In spite of that, there are evidences that the HBO can prevent hypothermia edema, keep the tecidual oxygenation during the preservation and hinder or diminish the formation of free radicals. CONCLUSION: HBO must be considered as the unique alternative or complementary technique in the preservation of the small bowell for transplant.

Effect of different periods of hyperbaric oxygen on ischemia-reperfusion injury of rat small bowel.

PURPOSE: To determine whether hyperbaric oxygen (HBO) could effectively protect the small intestine mucosa against an ischemic insult, according to different periods of application. METHODS: The gut of 32 male rats was subjected to 60-min ischemia (clamping the mesenteric artery and vein); After they were further reperfused upon clamp opening during 60 min. Animal groups were as follows. GII = placed on HBO during the ischemia period; GIII = placed on HBO during reperfusion; GIV = treated with HBO throughout the ischemia-reperfusion period. Some animals (GI) did not receive HBO treatment at all and served as reference of ischemia-reperfusion injury (IR). HBO was carried out in a cylindrical acrylic chamber (2.0 ATA). Samples of small bowel were prepared for H.E staining for histological evaluations. RESULTS: The histological injury of mucosa was significantly less when HBO was administered during the ischemia period (17.6 +/- 0.6) as compared with the IR (21.3 +/- 1.8). HBO was not effective when applied during reperfusion (23.1 +/- 2.1) or during the ischemia plus reperfusion period (18.7 +/- 1.9). The thickness of the mucosa was preserved by HBO in ischemia (327.50 +/- 30.23 microm) in comparison with the IR (172.79 +/- 5.95 microm). In the periods of reperfusion (162.50 +/- 6.05 microm) and ischemia plus reperfusion (296.49 +/- 20.01 microm) the mucosa revealed a structural injury. CONCLUSION: Hyperbaric oxygen affects the ischemic insult of small bowel, being the favorable effect obtained when hyperbaric oxygen was administered early in the ischemic period.