Doroty Mesquita Dourado

Low-level Laser Therapy Promotes Vascular Endothelial Growth Factor Receptor-1 Expression in Endothelial and Nonendothelial Cells of Mice Gastrocnemius Exposed to Snake Venom

Crotalinae snake venoms cause severe local myonecrosis and microvasculature failure at the bite site. We evaluated whether low‐level laser therapy (LLLT) could accelerate angiogenesis and myoregeneration in male Swiss mice injected with Bothrops moojeni venom through immunohistochemistry of the vascular endothelial growth factor receptor‐1 (VEGFR‐1). Envenomed gastrocnemius was either unirradiated (V) or irradiated with HeNe (VHN, 632.8 nm) or GaAs (VGA, 904 nm, 10000 Hz). Animals sacrificed at 3 and 12 h were irradiated once (4 J cm−2), at 24 h (twice) and at 3, 7, 21 days (4, 8, 22 times, respectively). At 3 days, LLLT increased angiogenesis (80%:HeNe vs 40%:GaAs), decreased neutrophils and increased proliferation of regenerating cells. However, after 21 days, myoregeneration observed in the VHN group appeared delayed compared with the V group. As LLLT improved revascularization, the suggestive delay in myoregeneration could be a dose‐response inhibitory effect caused by multiple irradiations in myogenesis. The immunodetection of VEGFR‐1 in neutrophils, macrophages, satellite cells, fibroblasts, Schwann cells and skeletal and smooth muscle fibers (not seen in saline‐controls) at only the acute stages of envenoming suggests a mediator role for VEGFR‐1 in local alterations. This is the first time that VEGFR‐1 expression, and its modulation by photostimulation, has been demonstrated in endothelial and nonendothelial cells of snake envenomed skeletal muscle.

Histological study of tendon healing in malnourished Wistar rats treated with ultrasound therapy

PURPOSE To investigate the effects of therapeutic ultrasound on the healing of tendon injuries in malnourished rats. METHODS After the intended nutritional states had been attained, the animals (N=36) were distributed into three groups, named: G1(N=12), control group; G2(N=12), malnourished rats treated with 3 MHz ultrasound at an intensity of 0.5 W/cm(2); and G3 (N=12), normal animals treated with 3 MHz at 0.5 W/cm(2). The injuries were induced by means of an operation to expose the heel tendon and crush it using Allis forceps. RESULTS The data obtained relating to leukocyte counts, fibroblasts, vessel neoformation, fibrosis and collagen were subjected to statistical treatment using analysis of variance (ANOVA) and Students t test. Results of p < 0.05 were obtained for fibrosis and collagen. CONCLUSION The ultrasound was shown to be effective in repairing the tendon, even in malnourished animals whose healing process was retarded.

The effect of sub-lethal doses of Azadirachta indica (Meliaceae) oil on the midgut of Spodoptera frugiperda (Lepidoptera, Noctuidae)

The fall armyworm, Spodoptera frugiperda, is one of the major field pests for maize production. It is mainly controlled by means of synthetic, and more recently by resistant cultivar of maize expressing Bt toxins. The neem tree, Azadirachta indica, is a plant that can potentially control insects with the advantage of being food and environmental safe. The aim of this study was to assess the effect of neem oil on the development and survival of S. frugiperda caterpillars by assessing histological alterations caused on their midgut. Newly hatched caterpillars were submitted to three neem oil concentrations: 0.006; 0.05; 0.4%, which were added to their artificial diet. Ten 3rd instar caterpillars, taken from each treatment, were submitted to histological analysis. The alimentary canals from the specimens were fixed in Baker for 12 hours, desiccated and diaphanized in alcohol/xylol (1:1) and xylol. After placing the samples in paraffin, they were sliced in 8 µm sections and stained with hematoxylin-eosin stain. The neem oil added to the diet of S. frugiperda caused total mortality at dose of 0.4% whilst still in the first instars, prolonged the larval and pupal stages, and reduced the pupal weight. Histo-physiological alterations such as degeneration of the epithelial lining of the midgut and in the peritrophic matrix were found at all concentrations of neem oil.

Análise da pele de três espécies de peixes: histologia, morfometria e testes de resistência

This study was carried out to analyse the skin of three species of fish (piavucu Leporinus macrocephalus, pacu prata Mylossoma sp e piraputanga Brycon hilarii) through histological and morphometrical analysis and resistance tests after hardening. Skin samples from the dorsal region were taken and fixed in Bouin solution for 24 hours. They were embedded in paraffin, cut 5 µm thick and stained by Hematoxylin-eosin technique. The cuts were analyzed by light microscopy. A EMIC dynamometer was used for the physical mechanical analysis of the skin in 10 samples, longitudinally oriented from the dorsal region of each specie of fish. The dermis of those fishes has a structural pattern common to teleosts, but the setting and distribution of collagen fibers was different among the analyzed species. The skin dermis thickness differed among the three species by the morphometrical analysis. No difference was observed for the resistance test to traction in piraputanga leather (16.88 N/mm2) as well as in piavucu leather (18.50 N/mm2). The results for the skin of both fish species were higher than those for pacu (11.83 N/mm2). The value of stretching as to the point of rupture was higher for piavucu (52.83%) and piraputanga (60.45%), showing no difference among them, but it was lower for pacu (33.83%). The progressive tearing was greater in pacu skin (36.51 N/mm). The skin of the three analyzed species can be turned into leather for the manufacture of several artifacts.

Efeito da técnica de curtimento e do método utilizado para remoção da pele da tilápia-do-nilo sobre as características de resistência do couro

Um estudo foi realizado com o objetivo de avaliar os efeitos do metodo de remocao da pele do file (com alicate e com maquina) e da tecnica de curtimento (com ou sem sais de cromo, bioleather) sobre a resistencia da pele de tilapia-do-nilo (Oreochromis niloticus). Foram retiradas as peles de 40 tilapias (450 g), 20 com uso de alicates e 20 com auxilio de maquina. Apos o curtimento e a retirada dos corpos-de-prova, as peles foram encaminhadas a um laboratorio aclimatizado (23oC e 50% de umidade relativa do ar) para realizacao dos testes de resistencia em dinamometro EMIC, com velocidade de afastamento entre cargas de 100 ± 20 mm/mm. O metodo de retirada da pele do file nao afetou os resultados dos testes de tracao e rasgamento progressivo. A pele retirada com a maquina apresentou elongacao superior (88,48%) a removida com alicate (71,09%). Peles curtidas com sais de cromo (25,54 N/mm; 12,18 N/mm2) foram mais resistentes que as curtidas sem sais de cromo (bioleather) (13,11 N/mm; 9,89 N/mm2). Peles curtidas por estas tecnicas (com cromo e bioleather) podem ser utilizadas na confeccao de vestuarios, pois as medias dos testes de tracao, alongamento e rasgamento progressivo foram superiores a 9,80 N/mm2, 60% e 14,72 N/mm, respectivamente, valores minimos recomendados para couros curtidos ao cromo.

Histologia da pele da carpa prateada (Hypophtalmichthys molitrix) e testes de resistência do couro

The objectives of this trial were to analyze the skin histology and to evaluate the influence of tanning technique and the direction removal of samples on skin quality of silver-plated carp (Hypophtalmichthys molitrix). Twenty-three fishes were sacrificed and the skin was removed for tanning. Samples of three fishes were settled in formol 10% and, after inclusion in paraffin, the samples were cut with approximately 5 mm of thickness and colored by the hematoxylin-eosin technique (HE). After skin tanning, the samples were removed for resistance tests. The tests were done with EMIC dynamometer, at removal speed of 100 ± 20 mm/mm, in a climatized environment (23oC) and 50% air relative humidity for 24-h period. The skins tanned with chromium salts showed greater resistance to tensile strenght (16.96 N/mm2), elongation (51.49%) and progressive tearing (16.75 N/mm) than those tanned without chromium salts (tensile strenght = 9.12 N/mm2, elongation = 17.48% and 11.36 progressive tearing = N/mm). No effect of direction removal of samples on tensile strenght, elongation, rupture load, progressive tearing, maximum force, and force load was observed. The tanning technique (with or without chromium salts) affect the resistance of the silver-plated carp skin. The technique with chromium salts results in bigger resistance to leather.

Evaluation of the Effects of Atorvastatin and Ischemic Postconditioning Preventing on the Ischemia and Reperfusion Injury: Experimental Study in Rats

Introduction Reperfusion injury leads to systemic morphological and functional pathological alterations. Some techniques are already estabilished to attenuate the damage induced by reperfusion. Ischemic preconditioning is one of the standard procedures. In the last 20 years, several experimental trials demonstrated that the ischemic postconditioning presents similar effectiveness. Recently experimental trials demonstrated that statins could be used as pharmacological preconditioning. Methods 41 Wistar rats (Rattus norvegicus albinus) were distributed in 5 groups: Ischemia and Reperfusion (A), Ischemic Postconditioning (B), Statin (C), Ischemic Postconditioning + Statins (D) and SHAM (E). After euthanasia, lungs, liver, kidneys and ileum were resected and submitted to histopathological analysis. Results The average of lung parenchymal injury was A=3.6, B=1.6, C=1.2, D=1.2, E=1 (P=0.0029). The average of liver parenchymal injury was A=3, B=1.5, C=1.2, D=1.2, E = 0 (P<0.0001). The average of renal parenchymal injury was A=4, B=2.44, C=1.22, D=1.11, E=1 (P<0.0001). The average of intestinal parenchymal injury was A=2, B=0.66, C=0, D=0, E=0 (P=0.0006). The results were submitted to statistics applying Kruskal-Wallis test, estabilishing level of significance P<0.05. Conclusion Groups submitted to ischemic postconditioning, to pre-treatment with statins and both methods associated demonstrated less remote reperfusion injuries, compared to the group submitted to ischemia and reperfusion without protection.

Healing effect of the ointment made of Equisetum pyramidale in the treatment of cutaneous lesions in diabetic rats

This study aimed to evaluate the anti-inflammatory and repair effects of the ethanolic extract and ointment of Equisetum pyramidale on the skin lesions of rats induced to diabetes. After the induction of diabetes with alloxan, a surgical procedure was performed on the back of each rat. Then, they were separated into treatment groups: G1 ethanol extract of E. pyramidale; G2-ointment (extract of E. pyramidale 80g + 20g of vaseline:lanolin 1:1); G3 control (vehicle vaseline:lanolin 1:1); and G4-no treatment during 3, 7 and 14 days. The samples were embedded in paraffin and stained with hematoxylin-eosin for histological analysis. The findings showed that the use of ethanolic extract as well as the ointment decreased the inflammatory cells at the site of inflammation, resulting a faster healing, with less crusting and lower amount of secretion in comparison to the control group. Therapy with topical herbal was an effective method in the inflammatory process of tissue repair, contributing to a faster and more organized tissue re-epithelialization.

Crotalus durissus sp. rattlesnake venom induces toxic injury in mouse sperm

Accidents involving snakebites constitute a serious public health problem in many regions around the world. However, there are no study about a possible action of snake venom on the reproductive system. Herein we show that Crotalus durissus sp. (Linnaeus) rattlesnake venom (25 μg/kg of body weight) affected chromatin condensation, and increased the number of sperm with abnormal morphology and the sperm count. In conclusion, besides the known hazards of the C. durissus sp. venom to animal health, this study was the first to show its effect also on male germ cells.

Effect of Ischemic Postconditioning and Atorvastatin in the Prevention of Remote Lung Reperfusion Injury

Objective The aim of the present study was to evaluate the ability of ischemic postconditioning, atorvastatin and both associated to prevent or minimize reperfusion injury in the lung of rats subjected to ischemia and reperfusion by abdominal aortic clamping. Methods We used 41 Wistar norvegic rats, which were distributed into 5 groups: ischemia and reperfusion (I/R), ischemic postcondictioning (IPC), postconditioning + atorvastatin (IPC+A), atorvastatin (A) and SHAM. It was performed a medium laparotomy, dissection and isolation of the infra-renal abdominal aorta; except for the SHAM group, all the others were submitted to the aortic clamping for 70 minutes (ischemia) and posterior clamp removal (reperfusion, 70 minutes). In the IPC and IPC+A groups, postconditioning was performed between the ischemia and reperfusion phases by four cycles of reperfusion and ischemia lasting 30 seconds each. In the IPC+A and A groups, preceding the surgical procedure, administration of 3.4 mg/day of atorvastatin was performed for seven days by gavage. After the surgical procedure, the right caudal lobe was removed from the lung for histological study, using tissue injury score ranging from grade 1 (normal tissue) to grade 4 (intense lesion). Results The mean lung injury was 3.6 in the I/R group, 1.6 in the IPC group, 1.2 in the IPC+A group, 1.2 in the A group, and 1 in the SHAM group (P<0.01). Conclusion Ischemic postconditioning and atorvastatin were able to minimize lung reperfusion injury, alone or in combination.