Electrocardiographic parameters of captive lions (Panthera leo) and tigers (Panthera tigris) immobilized with ketamine plus xylazine

Twenty-seven healthy captive lions (Panthera leo) and 13 healthy captive tigers (Panthera tigris) from S to Paulo Zoo (Fundacao Parque Zoologico de Rio Paulo, Sao Paulo, Brazil) collection were selected for this study. They were anesthetized with ketamine (10 mg/kg) combined with xylazine (1-2 mg/kg) for physical examinations. hematologic and serum chemical analysis and electrocardiogram recording. The main aim of this research was to gather initial information about normal electrocardiographic parameters of large felids. Standard P-QRS-T deflections on leads described for domestic carnivores were analyzed, and they did not greatly differ from those of large felids. taking into account the greater weight and corporal mass of large felids. Heart rate of lions ranged frorn 42 to 76 beats per minute (bpm). Heart rate of tigers ranged from 56 to 97 bpm. In both species, the most common rhythm detected was normal sinus rhythm followed by sinus arrhythmia: wandering, pacemaker was also observed with normal sinus rhythm or sinus arrhythmia. Mean electrical axis lay between +60 degrees and +120 degrees. QRS complexes were predominantly positive in leads DI, DII, DIII, and AVF and negative in AVR and AVL. This Study provides insights into normal electrocardiograms of large felids. Wider investigations on the same subject arc necessary to establish criteria for the recognition of abnormalities in these species and should include other anesthetic drug(s) combinations and reports of electrocardiographic features of animals with cardiac disease and electrolytes disturbances.

Hepatic Hemosiderosis in Red-Spectacled Amazons (Amazona pretrei) and Correlation with Nutritional Aspects

Alimentary habits of free-living Psittaciformes vary significantly among different species. Amazona pretrei is under risk of extinction and has very specific free-living dietary habits, which are based on Parana pine seeds. Hemosiderosis is a pathologic process characterized by intracellular accumulation of iron without other evident lesions. It is associated with increased prevalence of infections, neoplasms, and hepatopathies. The purpose of this study was to quantify hepatic hemosiderin deposits in captive A. pretrei and verify their association with nutritional parameters. Liver samples were processed for histopathology and stained with Prussian blue. The sections were analyzed by computerized morphometry to quantify the hepatic hemosiderin deposits. The hepatic hemosiderosis rates showed positive correlation with age and time in captivity. These results suggest that the menus and commercial rations for Psittacidae must be carefully revised.

Heat stress impairs performance parameters, induces intestinal injury, and decreases macrophage activity in broiler chickens

Studies on environmental consequences of stress on animal production have grown substantially in the last few years for economic and animal welfare reasons. Physiological, hormonal, and immunological deficits as well as increases in animals` susceptibility to diseases have been reported after different stressors in broiler chickens. The aim of the current experiment is to describe the effects of 2 different heat stressors (31 +/- 1 and 36 +/- 1 degrees C/10 h per d) applied to broiler chickens from d 35 to 42 of life on the corticosterone serum levels, performance parameters, intestinal histology, and peritoneal macrophage activity, correlating and discussing the obtained data under a neuroimmune perspective. In our study, we demonstrated that heat stress (31 +/- 1 and 36 +/- 1 degrees C) increased the corticosterone serum levels and decreased BW gain and food intake. Only chickens submitted to 36 +/- 1 degrees C, however, presented a decrease in feed conversion and increased mortality. We also showed a decrease of bursa of Fabricius (31 +/- 1 and 36 +/- 1 degrees C), thymus (36 +/- 1 degrees C), and spleen (36 +/- 1 degrees C) relative weights and of macrophage basal (31 +/- 1 and 36 +/- 1 degrees C) and Staphylococcus aureus-induced oxidative burst (31 +/- 1 degrees C). Finally, mild multifocal acute enteritis characterized by an increased presence of lymphocytes and plasmocytes within the jejunum`s lamina propria was also observed. The stress-induced hypothalamic-pituitary-adrenal axis activation was taken as responsible for the negative effects observed on the chickens` performance and immune function and also the changes of the intestinal mucosa. The present obtained data corroborate with others in the field of neuroimmunomodulation and open new avenues for the improvement of broiler chicken welfare and production performance.

Effects that bovine sperm cryopreservation using two different extenders has on sperm membranes and chromatin

The process of cryopreservation impairs sperm cell function, potentially leading to a reduction in fertility. The objectives of the present study were to evaluate the effects that cryopreservation using two different extenders has on sperm motility and mitochondrial function, as well as on the integrity of plasma membranes, acrosomal membranes and chromatin, using practical and objective techniques. The focus of the present study was to identify correlations between alterations in sperm membranes and sperm motility in cryopreserved bovine spermatozoa. Seven ejaculates were collected from eight Simmental bulls (n = 56). After collection, semen volume and concentration were assessed for purposes of dilution. Sperm motility was evaluated subjectively and by computer-assisted semen analysis, morphological characteristics were evaluated by differential interference microscopy, the integrity of plasma and acrosomal membranes, as well as mitochondrial function, were determined using a combination of fluorescent probes containing fluorescein isothiocyanate-Pisum sativum agglutinin, propidium iodide or 5,5`,6,6`-tetrachloro-1,1`,3,3`-tetraethylbenzimidazolearbocyanine iodide. Chromatin integrity was evaluated using the acridine orange technique. The semen was subsequently divided into two aliquots and diluted with one of two extenders (Bioxcell(R) or Botu-Bov(R)), after which both were packaged in 0.5 mL straws and frozen using an automated system. Two straws of semen from each treatment were thawed, and the semen parameters were evaluated as described above. Cryopreservation of sperm reduced motility, damaging plasma and acrosomal membranes, as well as decreasing mitochondrial function. The Botu-Bov(R) extender was more effective in preserving sperm motility and membrane integrity than was the Bioxcell(R) extender. (C) 2007 Elsevier B.V. All rights reserved.

Healing of displaced condylar process fracture in rats submitted to protein undernutrition

Introduction: This study evaluated the healing of mandibular condylar fracture in rats submitted to experimental and protein undernutrition (8% of protein) by means of histological analysis. Material: Forty-five adult Wistar rats were divided into three groups of 15 animals: a fracture group, who were submitted to condylar fracture with no changes in diet; an undernourished fracture group, who were submitted to a low protein diet and condylar fracture: an undernourished group, kept until the end of experiment, without condylar fracture. Displaced fractures of the right condyle were created under general anaesthesia. The histological study comprised fracture site and temporomandibular joint evaluations. Results: The undernourished fracture group showed significant weight loss. There was a marked decrease in the values of serum proteins and albumin in the undernourished fracture group. Histological analysis showed that protein undernutrition lead to atrophy of the condylar fibrocartilage. Fractures in undernutrition presented a delay in callus formation due to more extensive devitalized bone areas, and after 3 months there were still bone formation areas, while fibrous ankylosis occurred in the articular space. Conclusion: It was concluded that mandibular condyle fractures in rats with protein undernutrition had impaired callus formation, as well as fibrous ankylosis into the temporomandibular joint. (C) 2010 European Association for Cranio-Maxillo-Facial Surgery.

Dentine caries inhibition through CO(2) laser (10.6 mu m) irradiation and fluoride application, in vitro

Objective: The purpose of the study was to investigate whether dentine irradiation with a pulsed CO(2) laser (10.6 mu m) emitting pulses of 10 ms is capable of reducing dentine calcium and phosphorus losses in an artificial caries model. Design: The 90 dentine slabs obtained from bovine teeth were randomly divided into six groups (n = 15): negative control group (GC); positive control group, treated with fluoride 1.23% (GF); and laser groups irradiated with 8 J/cm(2) (L8); irradiated as in L8 + fluoride 1.23% (L8F); irradiated with 11j/cm(2) (L11); irradiated as in L11 + fluoride 1.23% (L11F). After laser irradiation the samples were submitted to a pH-cycling model for 9 days. The calcium and phosphorous contents in the de- and remineralization solutions were measured by means of inductively coupled plasma optical emission spectrometer - ICP-OES. Additionally intra-pulpal temperature measurements were performed. The obtained data were analysed by means of ANOVA and Tukey`s test (alpha = 0.05). Results: In the demineralization solutions the groups L11F and GF presented significantly lower means of calcium and phosphorous losses than the control group; and in L11F means were significantly lower than in the fluoride group. Both irradiation parameters tested caused intrapulpal temperature increase below 2 degrees C. Conclusion: It can be concluded that under the conditions of this study, CO(2) laser irradiation (10.6 mu m) with 11J/cm(2) (540 mJ and 10 Hz) of fluoride treated dentine surfaces decreases the loss of calcium and phosphorous in the demineralization process and does not cause excessive temperature increase inside the pulp chamber. (C) 2010 Elsevier Ltd. All rights reserved.

Mast cell concentration in the wound healing process of incisions made by different instruments

The aim of this study was to compare the concentration of mast cells (MCs) in the healing process of incisions. Thirty rats were submitted to six linear incisions each, performed in the dorsal skin by carbon dioxide (CO(2)) and diode lasers, electrocautery and conventional scalpel. The animals were euthanized at intervals of 0 h, 24 h, 48 h, 72 h, 7 days and 14 days after the incisions had been made. Histological sections were obtained and stained with toluidine blue for identification of MCs, which were manually counted by conventional microscopy in 20 microscopic fields in the border of the incision, near the granulation tissue, or in the area of new collagen formation, depending on intervals. The concentration of MCs was significantly higher in the wounds made by scalpel than in those made by other techniques at 48 h and 72 h. After 72 h the number of MCs was also significantly higher after electrocautery than after incisions made by 4 W CO(2) laser. On days 7 and 14, there was no significant difference in the MC count among the different types of incisions. In summary, the MC concentration varied after different surgical incisions at early phases of wound healing. At the end of the healing process, however, there were similar MC concentrations around the incisions, suggesting that, in standard incisions in the surgical techniques studied, the wound healing process ultimately occurred in a similar pattern.

Laser phototherapy effect on protein metabolism parameters of rat salivary glands

The aim of this study was to evaluate the effects of infrared diode laser phototherapy (LP) on tissues of the submandibular gland (SMG) and parotid gland (PG). Wistar rats were randomly divided into experimental (A and B) and control (C) groups. A diode laser, 808 nm wavelength, in continuous wave mode, was applied to the PG, SMG and sublingual gland in the experimental groups on two consecutive days. The doses were 4 J/cm(2) and 8 J/cm(2), and total energy was 7 J and 14 J, respectively. The power output (500 mW) and power density (277 mW/cm(2)) were the same for both experimental groups. In order to visualize the area irradiated by the infrared laser, we used a red pilot beam (650 nm) with 3 mW maximum power for the experimental groups. For the control group, the red pilot beam was the only device used. The SMG and PG were removed after 1 week of the first irradiation. Total protein concentration, amylase, peroxidase, catalase and lactate dehydrogenase assays were performed, as well as histological analysis. Statistical tests revealed significant increase in the total protein concentration for groups A and B in the parotid glands (P < 0.05). Based on the results of this study, LP altered the total protein concentration in rats` parotid glands.

CO(2) Laser (10.6 mu m) Parameters for Caries Prevention in Dental Enamel

Although CO(2) laser irradiation can decrease enamel demineralisation, it has still not been clarified which laser wavelength and which irradiation conditions represent the optimum parameters for application as preventive treatment. The aim of the present explorative study was to find low-fluence CO(2) laser (lambda = 10.6 mu m) parameters resulting in a maximum caries-preventive effect with the least thermal damage. Different laser parameters were systematically evaluated in 3 steps. In the first experiment, 5 fluences of 0.1, 0.3, 0.4, 0.5 and 0.6 J/cm(2), combined with high repetition rates and 10 mu s pulse duration, were chosen for the experiments. In a second experiment, the influence of different pulse durations (5, 10, 20, 30 and 50 mu s) on the demineralisation of dental enamel was assessed. Finally, 3 different irradiation times (2, 5 and 9 s) were tested in a third experiment. In total, 276 bovine enamel blocks were used for the experiments. An 8-day pH-cycling regime was performed after the laser treatment. Demineralisation was assessed by lesion depth measurements with a polarised light microscope, and morphological changes were assessed with a scanning electron microscope. Irradiation with 0.3 J/cm(2), 5 mu s, 226 Hz for 9 s (2,036 overlapping pulses) increased caries resistance by up to 81% compared to the control and was even significantly better than fluoride application (25%, p < 0.0001). Scanning electron microscopy examination did not reveal any obvious damage caused by the laser irradiation. Copyright (C) 2009 S. Karger AG, Basel

Effect of defocused infrared diode laser on salivary flow rate and some salivary parameters of rats

This study aims to investigate whether infrared diode low-level laser therapy (LLLT) increased salivary flow rate and altered pH value, protein concentration, and peroxidase and amylase activities in saliva of rats. Wistar rats were used and divided into three groups. Experimental groups (A and 13) had their parotid, submandibular and sublingual glands submitted to diode laser, 808-nm wavelength, on two consecutive days. The dose results were 4 and 8 J/cm(2), respectively. A red guide light was used to visualize the irradiated area. Group C was irradiated only with red pilot beam and served as control. The saliva samples were collected after each irradiation step (first and second collection days) and 1 week after the first irradiation (seventh day). Statistical analysis was performed, and differences were observed according to different days of salivary collection. The results showed that salivary flow rate for groups A and B was higher on the seventh day if it is compared to data obtained for the first day (p<0.05). LLLT applications on salivary glands are a therapy procedure that requires further studies.