Histologic and immunohistochemical evaluation of intestinal innervation in dogs with and without intussusception

Objective-To assess viability of innervation in bowel segments appearing macroscopically viable from dogs with intussusception. Animals-7 dogs without gastrointestinal dysfunction that had been euthanized for reasons unrelated to the study (control dogs) and 13 dogs with intussusception that underwent enterectomy and intestinal anastomosis (affected dogs). Procedures-A total of 31 samples of intestinal tissue were obtained from the control dogs; 28 samples were obtained from affected dogs during surgery. Samples were histologically and immunohistochemically prepared and subjectively scored for degree of vacuolization and staining, respectively. Other data collected included mean muscle cell density of circular and longitudinal muscular layers, ratio between areas of muscular layers, mean number of myenteric plexuses, mean ganglion cell density of myenteric plexuses, and degree of degeneration in neuronal plexuses as estimated through synaptophysin and neuron-specific enolase (NSE) immunoreactivity. Results-Mean muscle cell density of longitudinal muscular layers, ratio between areas of muscular layers, and synaptophysin immunoreactivity did not differ significantly between affected and control dogs; values of all other variables did. Correlations were evident between mean ganglion cell density in myenteric plexuses and mean muscle cell density in circular muscular layers, degree of neuronal degeneration in myenteric plexuses and NSE immunoreactivity, and degree of neuronal degeneration in myenteric plexuses and mean ganglion cell density of myenteric plexuses. Conclusions and Clinical Relevance-Innervation may be impaired in bowel segments that appear macroscopically viable. Therefore, careful evaluation of preserved surgical margins during enterectomy and enteroanastomosis and monitoring of digestive function after surgery are important. (Am J Vet Res 2010;71:636-642)

Collection and evaluation of semen from the three-toed sloth (Bradypus tridactylus)

Sloths (Bradypus sp.) are extremely sensitive animals that suffer with the destruction and fragmentation of forests. They present a low population growth rate and need to be further studied for the preservation of the specie. Thus, the aim of this study was to establish an efficient semen collection protocol as well as characterize sperm concentration, motility and morphology in order to contribute with information about the reproductive traits of this specie, which has never been described in the literature before. For that, nine Bradypus tridactylus males were captured during the wet season and six during the dry season, in Manaus (AM), located in the north region of Brazil, semen was collected by electroejaculation with shocks given in sequences of progressive intensities (minimum 20 mA and maximum 60 mA). All animals ejaculated small volumes of semen and in some of them, the volume ejaculated was not enough for a complete spermiogram. Physical characteristics observed on the collections of the wet season were different from those seen in the specimen collected in the dry season. Motility an vigor was very low and did not show forward progression, only oscillatory movement. After Spermac stain, spermatozoa presented a wide variety of defects; however, the differences in morphology were not significant between seasons. The morphology assessed by scanning electron microscopy shows that the head in both groups could be elongated, short or could have a base narrower than the apex and the midpiece narrowed abruptly, forming a nip in its transition to the tail. Although further studies are necessary to verify our preliminary findings concerning seasonal variation in sperm quality, these results demonstrate that semen can be safely collected from sloths by electroejaculation and provide the first reports of semen characteristics in this species. (C) 2008 Elsevier Ltd. All rights reserved.

Physical, epidemiological, and molecular evaluation of infection by Cryptosporidium galli in Passeriformes

Due to the scarcity of information related to the epidemiology of Cryptosporidium infection in passerine birds, this study aimed to determine the periodicity of fecal shedding of Cryptosporidium spp. oocysts, after natural infection, and its clinical signs, mortality, and molecular characterization. Four hundred eighty fecal samples were collected from 40 birds, including 372 samples from 31 adult birds and 108 samples from nine young birds (up to 12 months old), housed in five aviaries, monthly from September 2007 to September 2008, with the exception of April. The birds originated from aviaries in which the following species were raised: great-billed seed-finch (Oryzoborus maximiliani), lesser seed-finch (Oryzoborus angolensis), ultramarine grosbeak (Cyanocompsa brissonii), and rusty-collared seedeater (Sporophila collaris). The samples were preserved in 2.5% potassium dichromate at 4A degrees C until processing. The oocysts were purified by centrifugal flotation in Sheather`s solution, followed by genomic DNA extraction and molecular characterization of oocysts using the nested polymerase chain reaction for amplification of fragments of the 18S subunit of rRNA gene. Intermittent shedding of oocysts was observed by positive amplification for Cryptosporidium spp. in 91 (24.5%) samples of adult birds and 14 (13%) of young birds. The sequencing of the amplified fragments enabled the identification of Cryptosporidium galli. Although all the aviaries had birds positive for C. galli, morbidity or mortality was observed in only one aviary and was associated with concomitant infection with Escherichia coli and Isospora sp.

Evaluation of the Possibility of Removing Staining by Repolishing Composite Resins Submitted to Artificial Aging

This in vitro research verified the possibility of eliminating staining caused by coffee and red wine in five composite resins, after being submitted to thermal cycling. Thirty-six specimens were prepared and immersed in water at 37 degrees C for 24 hours. After polishing, specimen color was measured in a spectrophotometer Cintra 10 UV (Visible Spectrometer, GBC, Braeside, VIC, Australia). All specimens were submitted to thermal cycling at temperatures of 5 and 55 degrees C with a dwell time of 1 minute, for 1,000 cycles in a 75% ethanol/water solution. After thermal cycling, the specimens were immersed in water at 37 degrees C until 7 days had elapsed from the time the specimens were prepared. All specimens were then taken to the spectrophotometer for color measurement. The specimens were divided into three groups (N = 12): distilled water (control), coffee, and red wine. For the staining process to occur on only one surface, all the sides, except one, of the surfaces were isolated with white wax. The specimens were immersed in one of the solutions at 37 degrees C for 14 days. The specimens were dried and taken to the spectrophotometer for color measurement. After this, the specimens were submitted to 20 mu m wear three times, and the color was measured after each one of the wear procedures. Calculation of the color difference was made using CIEDE2000 formula. According to the methodology used in this research, it was concluded that the staining caused by coffee and red wine was superficial and one wear of 20 mu m was sufficient to remove the discoloration.

In vitro evaluation of erbium, chromium:yttrium-scandium-gallium-garnet laser-treated enamel demineralization

This study evaluated the effect of different parameters of erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser irradiation on enamel mineral loss in a simulated caries model. Forty-five enamel samples obtained from third molar teeth (3 mmx 3 mm) were randomly divided into five groups (n = 9): G1-Er,Cr:YSGG laser at 0.25 W, 20 Hz, 2.8 J/cm(2); G2-Er,Cr:YSGG laser at 0.50 W, 20 Hz, 5.7 J/cm(2); G3-Er,Cr:YSGG laser at 0.75 W, 20 Hz, 8.5 J/cm(2); G4-sodium fluoride (NaF) dentifrice (positive control); G5-no treatment (negative control). After irradiation, the samples were submitted to 2 weeks of pH cycling. After the acid challenge, the samples were assessed by cross-sectional microhardness at different depths from the enamel surface. Analysis of variance (ANOVA) and Student-Newman-Keuls tests were performed (alpha = 5%). The percentage of lesion inhibition for each group was: G1 37%; G2 38%; G3 64%, and G4 50.5%. Regarding the relative mineral loss values (micrometers x volume percent), groups G1 (1,392 +/- 522) and G2 (1,292 +/- 657) did not differ significantly from each other, but both had higher values than group G3 (753 +/- 287); the groups irradiated with Er,Cr:YSGG laser did not differ from group G4. Although the findings of the study revealed that Er,Cr:YSGG laser irradiation at 8.5 J/cm(2) can be an alternative for the enhancement of the enamel`s resistance to acid, lower energy densities also produced a cariostatic potential comparable to the use of fluoride dentifrice.

Micro-hardness evaluation of a micro-hybrid composite resin light cured with halogen light, light-emitting diode and argon ion laser

This in vitro study aimed to determine whether the micro-hardness of a composite resin is modified by the light units or by the thickness of the increment. Composite resin disks were divided into 15 groups (n = 5), according to the factors under study: composite resin thickness (0 mm, 1 mm, 2 mm , 3 mm and 4 mm) and light units. The light activation was performed with halogen light (HL) (40 s, 500 mW/cm(2)), argon ion laser (AL) (30 s, 600 mW/cm(2)) or light-emitting diode (LED) (30 s, 400 mW/cm(2)). Vickers micro-hardness tests were performed after 1 week and were carried out on the top surface (0 mm-control) and at different depths of the samples. Analysis of variance (ANOVA) and Tukey tests (P a parts per thousand currency signaEuro parts per thousand 0.05) revealed no statistically significant difference among the light units for the groups of 0 mm and 1 mm thickness. At 2 mm depth, the AL was not statistically different from the HL, but the latter showed higher micro-hardness values than the LED. In groups with 3 mm and 4 mm thickness, the HL also showed higher micro-hardness values than the groups activated by the AL and the LED. Only the HL presented satisfactory polymerization with 3 mm of thickness. With a 4 mm increment no light unit was able to promote satisfactory polymerization.