Animals Of GII Research Articles

Chemopreventive and therapeutic efficacy of thymoquinone on experimentally induced hamster buccal pouch carcinogenesis

Aim: The present study aimed to investigate the chemopreventive and therapeutic effect of thymoquinone (TQ) on experimentally induced hamster buccal pouch carcinogenesis. Methodology : 40 Syrian male hamsters were classified into 4 equal groups (G(s)) of 10 each. GI: The animals remained untreated. The pouches of animals in GII, GIII, and GIV were painted 3 times a week for 14 weeks (ws). with 7,12-dimethylbenz (a) anthracene (DMBA). GII: No additional treatment was administered. Those in GIII: oral administration of TQ at a dose of 30 mg kg-1, one week before, as well as, during the application of DMBA on alternate days for 14 ws, whereas in GIV: The animals were injected intraperitoneally (IP) with TQ 50 mg/kg body weight thrice a week for 3ws. After the end of the experiment, the gross observations were made. Then, the fresh pouch specimens were surgically bisected into two pieces, one for Hematoxylin and Eosin (H&E) stain and immunohistochemistry (IHC) stain using Bcl-2. The other piece was used for apoptosis detection through a flow cytometry (FCM) test. Results: Gross observation showed variation in reduction of the tumor size in chemoprevention and treated group compared to the DMBA treated group.

Therapeutic efficacy of time-dependent cetuximab on experimentally induced hamster buccal pouch carcinoma

Purpose: This study aimed to determine the cetuximab therapeutic potential in the time-dependent fashion in experimentally induced hamster buccal pouch (HBP) carcinoma. Material and methods: Forty Syrian male hamsters were classified into four equal groups (G) of ten each. GI: The animals remained untreated to act as negative controls. The right pouches of animals in GII, GIII, and GIV were painted three times a week for 14 weeks (w)s with 7,12-dimethylbenz (a) anthracene (DMBA). GII: No additional treatment was administered. While, the animals in GIII and GIV were treated differently. Those in GIII received cetuximab intraperitoneally (IP) three intervals a week for three (w)s, whereas those in GIV received cetuximab IP three intervals for six (w)s. After the end of the experiment, the gross observations were made, and blood samples (2ml) were withdrawn from the inner canthus of the eye for analysis of whole white blood cells (WBCs) and oxidative stress markers [glutathione (GSH) and malondialdehyde (MDA) levels]. All pouches were surgically bisected for preparation for Hematoxylin and Eosin (H&E) stain and immunohistochemistry (IHC) stain using epidermal growth factor receptor (EGFR). Other fresh tissue was used for DNA detection through a flow cytometry (FCM) test.

Does Spinal Block Through Tattooed Skin Cause Histological Changes in Nervous Tissue and Meninges?: An Experimental Model in Rabbits.

Although there is no documented evidence that tattoo pigments can cause neurological complications, the implications of performing neuraxial anesthesia through tattooed skin are unknown. In this study, we aimed to assess whether spinal puncture performed through tattooed skin of rabbits determines changes over the spinal cord and meninges. In addition, we sought to evaluate the presence of ink fragments entrapped in spinal needles. Thirty-six young male adult rabbits, each weighing between 3400 and 3900 g and having a spine length between 38.5 and 39 cm, were divided by lot into 3 groups as follows: GI, spinal puncture through tattooed skin; GII, spinal puncture through tattooed skin and saline injection; and GIII, spinal puncture through skin free of tattoo and saline injection. After intravenous anesthesia with ketamine and xylazine, the subarachnoid space was punctured at S1-S2 under ultrasound guidance with a 22-gauge 2½ Quincke needle. Animals in GII and GIII received 5 μL/cm of spinal length (0.2 mL) of saline intrathecally. In GI, the needle tip was placed into the yellow ligament, and no solution was injected into the intrathecal space; after tattooed skin puncture, 1 mL of saline was injected through the needle over a histological slide to prepare a smear that was dyed by the Giemsa method to enable tissue identification if present. All animals remained in captivity for 21 days under medical observation and were killed by decapitation. The lumbosacral spinal cord portion was removed for histological analysis using hematoxylin-eosin stain. None of the animals had impaired motor function or decreased nociception during the period of clinical observation. None of the animals from the control group (GIII) showed signs of injuries to meninges. In GII, however, 4 animals presented with signs of meningeal injury. The main histological changes observed were focal areas of perivascular lymphoplasmacyte infiltration in the pia mater and arachnoid. There was no signal of injury in neural tissue in any animal of both groups. Tissue coring containing ink pigments was noted in all GI smears from the spinal needles used to puncture the tattooed skin. On the basis of the present results, intrathecal injection of saline through a needle inserted through tattooed skin is capable of producing histological changes over the meninges of rabbits. Ink fragments were entrapped inside the spinal needles, despite the presence of a stylet.

Evaluation of Dextrose Water, Black Tea and Orange Juice on Histopathologic Recovery of Surgery-Induced Intestinal Damage in Rabbits

BackgroundThe increase in intestinal permeability following damage to the intestinal mucosa in any surgical procedure, trauma or fasting is well- known.ObjectivesOur objective was to experimentally evaluate whether antioxidant consumption is associated with decreased intestinal damage in intestinal surgical procedures.Materials and MethodsForty rabbits were used to compare the pathological changes in the intestine after consumption of dextrose water 5% (D5W), black tea and orange juice in fasting and in cases with intestine resection and anastomosis. They were divided in to five groups as shams (GI), NPO (G II), D5W (GIII), black tea (GIV) and orange juice groups (GV). In GII to GV group with median laparotomy, a 2 cm segment of jejunum was resected and ends of the bowel were anastomosed. Postoperatively, animals fasted for five days. Animals in GII were killed after five days of fasting. On day five case groups were given free access to drinking D5w (GIII), black tea solution (G IV) and orange juice (GV) for a further 7 days. On day 8, animals were reoperated and the repaired segment of intestine was removed. Morphologic data were compared in groups.ResultsThere were 8 rabbits in each group. There was a significant difference in villi lengths in the groups (P = 0.003). GV rabbits had obvious recovery of the villous architecture.ConclusionsOrange juice as a source of vitamin C may be an appropriate liquid for postoperative recovery following intestinal surgery.

The role of N-acetyl-cysteine in the lung remote injury after hepatic ischemia and reperfusion in rabbits

To study the lesions in the lung of rabbits caused by ischemia/reperfusion hepatic (I/R) after the use of N-acetyl-cysteine (NAC). Twenty-four rabbits distributed in two groups: control group GI (n = 12) 5% glucose solution and experiment group GII (n = 12) NAC. The animals were pre-anesthetized with 1% acepromazine maleate and anesthetized with ketamine 10% and 2% xylazine intramuscularly. The GI and GII were given glucose solution intravenously or NAC 15 min before occlusion of the hepatic pedicle (30 min). After the period of reperfusion of 24h (n = 6) or 48 h (n = 6), liver and lung samples were collected for histology and immunohistochemistry to assess the impairment of cell. The animals of GII and GII-24h-48 h showed parenchyma liver close to normal, when using NAC. The GII and GII-24h-48 h showed lower thickness of alveolar cells that GI and GI-24h-48 h. The expression of caspase 3 in lung cells GII presented smaller value compared to the GI group. N-acetyl-cysteine administered 15 min prior to the injury ischemia/reperfusion had a significant protective role by minimizing lung injury and apoptotic morphology in the period observed.

Intravesical oxybutynin protects the vesical wall against functional and smooth muscle changes in rabbits with detrusor overactivity

The aim of this study was to evaluate the protective effect of intravesical oxybutynin on the bladder wall of rabbits with detrusor overactivity and partial bladder outlet obstruction (PBOO). Forty-five North Folk male rabbits were randomly distributed into GI, used as control (n = 15), GII-PBOO (n = 14), and GIII-PBOO + intravesical oxybutynin (n = 15). Connective tissue and elastic fibers were quantified as volumetric density on picrosirius red and Weigert's Fuchsin-Resorcin-stained sections, respectively. In T2, bladder weight was significantly higher in animals in GII and GIII. Smooth muscle bundle diameter was increased by 42% in GII compared with GI (p < 0.02).Elastic fibers were significantly higher in GII and GIII as compared with control group. Collagen concentration in GIII and GII was significantly lower than G1 (p < 0.025). Intravesical oxybutynin protected against structural and functional detrusor modifications of the partially obstructed bladder.

Histological evaluation of experimentally induced subluxation in rat molars and its implications on the management of orthodontic treatment

The purpose of this study was to evaluate the histological alterations occurred in the periradicular region of rat molars after intentional subluxation using an experimental method to induce dentoalveolar trauma. Eighteen adult male Wistar rats (Rattus norvegicus albinus) were selected for the study. The dentoalveolar trauma was experimentally induced by the application of an occlusogingival force on the occlusal surface of the maxillary right first molar using a tensiometer secured on a fully articulated support with adjustable steel shafts. The animals were assigned to six groups (n = 3), according to the intensity of the force applied to induce trauma: Group I (GI, control) - no force application; Groups II-VI (GII-GVI) - the animals were subjected to 600, 700, 800, 900 and 1000 cN force, respectively. After experimental induction of trauma, the animals were sacrificed by anesthetic overdose and the right maxillas were removed and processed for histological analysis under light microscopy. In the animals of GII, GIII and GIV, the histological alterations were similar to those described for GI. GVI (1000 cN) presented the most severe alterations, with the occurrence of buccal bone plate fracture, alveolar fracture and root fracture, which are not present in mild traumatic injuries like subluxation. The 900 cN force (GV) was capable to produce clinical and histological alterations in the gingival and periodontal tissues compatible with those observed in subluxation.

8 EFFECT OF SEMEN TYPES (SEXED v. NONSEXED) ON CONCEPTION RATES OF GIROLANDO HEIFERS INSEMINATED IN FIXED-TIME AI

With the goal of optimizing protocols, fixed-time artificial insemination (FTAI) was performed under field conditions in a study to evaluate conception rates in Girolando (5/8) heifers (18 to 24 months of age) treated with estradiol benzoate (BE) to induce ovulation. Forty heifers were allocated to 2 groups with 20 animals each: GI-sexed semen (2 million spermatozoa/dose) and GII-nonsexed semen (20 million spermatozoa/dose), with body condition score (BCS) of 3.0 ± 0.14 (scale of 1 to 5), middleweight of 335 ± 38 kg, so that it was made for reutilization of progesterone device. On Day 0 (morning), the animals received 2.0 mg of BE (RIC-BE®,Tecnopec, São Paulo, Brazil), 0.075 mg of D-cloprostenol (Prolise®, ARSA S.R.L., Buenos Aires, Argentina), and an intravaginal device of 1 g of progesterone (Primer®, Tecnopec). On Day 8 (morning) the device was removed and 0.075 mg of D-cloprostenol was managed in the GI animals, then these animals received 1.0 mg of BE 24 h after device removal. The insemination was in the late afternoon of Day 10 with a 6-hour delay (4 to 6 pm). The GII animals received Primer previously used for 8 days (being used in the GI animals under the same protocol). After pregnancy diagnosis at 60 days, a third group was created (GIII) using the not-pregnant animals of GI and GII. In GIII, Primer from third use [disinfected in solution Kilol®-L 1:250 (Quinabra, São Paulo, Brazil) and rinsed with water, dried, and packed in plastic sacks and kept for 60 days] was used following the GI protocol with sexed semen. There were no significant differences (P &gt; 0.05) in the conception rates of 40, 58, and 65% among groups GI (8/20), GII (11/20), and GIII (13/20). These results indicate very good conception rates for heifers, contrary to recommendations of commercial companies of sexed semen that alert for the conception rate for mated animals to be lower when using FTAI and mating protocols in mass, compared with that of AI after estrus observation.

Effects of hexestrol on mouse ovarian morphology and ovulation

Objective To analyze histological aspects of ovaries as well as the ovulation of adult mice treated with the anabolic agent hexestrol. Methods Thirty adult mice were divided into three groups of 10 animals each: (GI) the animals received a dose of 3 mg/kg of hexestrol; (GII) the animals were given a dose of 6 mg/kg of hexestrol; (GIII) the animals were injected with distilled water (vehicle). Another 10-animal group (GIV) was included, and these mice were injected with propionate testosterone (1.25 mg) after 5 days from the day of birth. Hexestrol was administered intraperitoneally once a day and the treatment lasted 30 days. The mice were then sacrificed; their ovaries and oviducts were removed, submitted to histological routine and analyzed under light microscopy. Results In mice treated with hexestrol (6 mg/kg) (Group II), ovaries were smaller than those from the controls but highly vascularized; similar results were obtained in GIV. A great number of follicles in several stages of development were found – however, with no corpora lutea – in six animals in GII. No corpora lutea were found in GIV. The number of luteal bodies and oocytes in GII was lower than that in GI or GIII. No oocytes were detected in GIV. Finally, the nuclear volume of interstitial cells in GII and GIV was the largest. Conclusion Our data suggest that the anabolic agent hexestrol in a high dose may decrease ovulation in mice.

EFFECT OF PERITONEAL LAVAGE ON SYSTEMIC INFLAMMATORY RESPONSES IN RATS WITH ACUTE PANCREATITIS.

Introduction: Acute pancreatitis (AP) is characterized by release of proteolytic enzymes from the pancreas and activation of the inflammatory cytokine cascade that mediates the systemic manisfestations of the disease. In fact, the peritoneal exudate that develops during AP attacks has been found to contain a number of biologically active components which may be harmful to the patient. Aim: To investigate the effect of peritoneal lavage on the systemic inflammatory response in a rat model of severe AP. Methods: AP was induced in male Wistar rats by intraductal 5% taurocholate injection. Peritoneal lavage was carried out by infusion of 200 ml of warm (37 °C) 1.5% glucose-based peritoneal dialysis fluid at a constant flow (50 ml/h). Animals were divided in 2 groups: Group I (n = 16): Animals with AP not treated by peritoneal lavage Group II (n = 16): Animals with AP treated by peritoneal lavage immediately after the induction of AP. After 4 hours of AP induction serum levels of amylase, TNF-α, IL-6 and IL-10 were determined. Systemic lesions were analyzed by phosphorylation of liver mitochondria and pulmonary MPO determination. Results: A significant decrease of TNF-α (7 ± 5 vs 32 ± 10 pg/ml) and IL-6 (141 ± 26 vs 258 ± 46 pg/ml) plasma levels was observed in animals submitted to peritoneal lavage (GII) when compared to animals that did not receive peritoneal lavage (GI) (p < 0.05). Also, a significant increase of IL-10 (133 ± 44 vs 39 ± 8 pg/ml) plasma levels was observed in animals of GII when compared to GI (p < 0.05). The group receiving peritoneal lavage had a significant reduction of liver mitochondria dysfunction: RCR (2.47 ± 0.08 vs 2.25 ± 0.06) and respiration state 4 (39.01 ± 2.29 vs 48.54 ± 3.28 nmol O2/mg prot/min) when compared to group not treated with peritoneal lavage (p<0.05). There were no significant differences on plasma amylase levels and pulmonary MPO between both groups. Conclusion: These results indicate that peritoneal lavage attenuates the systemic inflammatory response by a reduction on plasma levels of TNF-α and IL-6, an increase of IL-10, and through a protective effect on uncoupling of mitochondrial oxidative phosphorylation in this model of experimental AP.

Proporção volumétrica dos constituintes do corpo lúteo de Nelore

Volumetric proportions and nuclear diameter of the small and large luteinic cells of the corpus luteum (CL) were evaluated in ovaries of 17 Nelore cows and heifers, collected in slaughterhouse and classified into two groups: group I (GI, n=7), non-pregnant animals, and group II (GII, n=10), pregnant animals. The CL was reduced to small cuts (less than 3mm), which were fixed in Bouin solution and processed for morphometric analysis. The volumetric proportion analysis showed higher mean in the GI animals for the nuclei and cytoplasm of luteinic cells, while the mean of connective tissue and fibroblasts was higher in the GII animals, while the mean of the capillary endothelial cells and pericytes did not differ between the groups. The average nuclear diameter of the large and small luteinic cells did not differ between the groups.

Effects of a 5% monosulfated glycosaminoglycan and duasorb topic solution on alkali-burned rabbit corneas

Topical effects of chondroitin sulfate, a monosulfated glycosaminoglycan, on the healing of alkali-burned corneas were studied.Forty albino rabbits were divided into two groups (GI and GII, n =20) submitted to corneal ulceration with 3 M sodium hydroxide(NaOH). GI was treated with a topical solution of 5% chondroitin sulfate 4 and chondroitin sulfate 6 and GII was treated with 0.9%physiological saline at 6 hour intervals in both cases. The rabbits were studied over a period of 60 days by biomicroscopy witha slit lamp in order to evaluate blepharospasm, blepharitis, chemosis, conjunctival congestion, ocular secretion, and cornealedema, neovascularization and macula. The fluorescein test was performed daily to monitor the evolution of the ulcers. Theanimals were submitted to eye enucleation for histopathology on the 1st, 3rd, 10th, 30th and 60th day after ulcer induction. Whencompared to GII, GI showed 4 perforations. In the eyes in which no perforation occurred, no clinical or microscopic differenceswere observed between groups, except for ocular secretion, which persisted for a longer time in GII animals. Except for thosewith perforations, the corneas tended to heal, on average, within 30 days. The results permit us to conclude that the 5%chondroitin sulfate solution, when instilled on alkali-burned rabbit corneas did not alter healing when compared to the animalstreated with 0.9% physiological saline.

Avaliação comparativa entre acepromazina, detomidina e romifidina em eqüinos

Os efeitos da acepromazina, detomidina e romifidina em eqüinos foram comparados, objetivando-se determinar qual o agente mais seguro e efetivo para a referida espécie animal. Foram utilizados 15 eqüinos hígidos, de ambos os sexos, idades e raças variadas e encaminhados ao setor de Cirurgia do Hospital Veterinário da FMVZ - USP. Os animais foram distribuídos em três grupos: grupo I, recebeu 0,1mg/kg de acepromazina; grupo II recebeu 20mcg/kg de detomidina e grupo III, o qual recebeu 80mcg/kg de romifidina, sendo todos os agentes administrados através da via intravenosa. Previamente à administração dos fármacos e aos 15, 30, 60 e 90 minutos, após sua aplicação, foram avaliadas a freqüência e ritmo cardíacos, freqüência respiratória, pressão arterial sistólica e diastólica, assim como foram coletadas amostras de sangue arterial para verificação do pH, pressão parcial de oxigênio e pressão parcial de dióxido de carbono. Os resultados foram submetidos à análise estatística através do teste de análise de variância (ANOVA), seguido do teste de Tukey. Não foi observada nenhuma alteração da freqüência respiratória nos grupos estudados. Verificou-se diminuição significativa dos valores da FC nos animais tratados com os agentes alfa-2 agonistas quando comparados com os valores obtidos no grupo I. Após a administração da acepromazina, observou-se diminuição significativa das pressões sistólica e diastólica em relação aos valores controle. Os animais do grupo I apresentaram valores pressóricos estatisticamente inferiores em relação aos valores obtidos nos grupos II e III. Os animais do grupo II demonstraram incremento da pressão arterial sistólica após 15 minutos da aplicação do agente, com subseqüente redução destes valores. O mesmo ocorreu no grupo III, porém, sem valor estatístico significativo. Com estes resultados, pode-se concluir que a romifidina e a detomidina promoveram alterações paramétricas de menor intensidade e duração quando comparadas à acepromazina.