The role of the oblique ligament in the mechanical behavior of the medial collateral ligament of the mongrel dog elbow joint - Some biomechanical aspects

This study investigated the oblique ligament mechanical contribution to the medial collateral ligament of the canine elbow joint. Fifteen dogs were used for the study of the failure load, displacement, and energy absorption of the medial collateral and oblique ligaments of the canine elbow joint, associate and separately in the joint. Medial collateral ligament failure load and energy absorption were significantly higher in relation to the isolated oblique ligament. When the ligaments were associated in the joint, they presented an increment in failure load, displacement and energy absorption in relation to the ligaments analyzed separately. It was concluded, therefore, that the oblique ligament could have an important paper in the stability of the canine elbow joint, as it favors the medial collateral ligament resistance to the tensile load, one of the main stabilizer of the elbow joint.

Plutonismn in three orogenic pulses, Eastern Blue Ridge Province, southern Appalachians

The Eastern Blue Ridge Province of the southern Appalachians contains, in part, remnants of an Ordovician accretionary wedge complex formed during subduction of an oceanic tract before mid-Ordovician accretion with Laurentia. The Eastern Blue Ridge Province consists of metapelite and amphibolite intruded by low-K plutons, high-temperature (T >750 °C) Ordovician eclogite, and other high-pressure metamafic and meta-ultramafic rocks. Felsic plutons in the Eastern Blue Ridge Province are important time markers for regional-scale tectonics, deformation, and metamorphism. Plutons were thought to be related to either Taconian (Ordovician) or Acadian (Devonian-Silurian) tectonothermal events. We dated five plutonic or metaplutonic rocks to constrain pluton crystallization ages better and thus the timing of tectonism. The Persimmon Creek gneiss yielded a protolith crystallization age of 455.7 ± 2.1 Ma, Chalk Mountain 377.7 ± 2.5 Ma, Mt. Airy 334 ± 3Ma, Stone Mountain 335.6 ± 1.0 Ma, and Rabun 335.1 ± 2.8 Ma. The latter four plutons were thought to be part of the Acadian Spruce Pine Suite, but instead our new ages indicate that Alleghanian (Carboniferous-Permian) plutonism is widespread and voluminous in the Eastern Blue Ridge Province. The Chattahoochee fault, which was considered an Acadian structure, cuts the Rabun pluton and thus must have been active during the Alleghanian orogeny. The new ages indicate that Persimmon Creek crystallized less than 3 m.y. after zircon crystallization in Eastern Blue Ridge eclogite and is nearly synchronous with nearby high-grade metamorphism and migmatization. The three phases of plutonism in the Eastern Blue Ridge Province correspond with established metamorphic ages for each of the three major orogenic pulses along the western flank of the southern Appalachians. © 2006 Geological Society of America.

Atlantic forest fragmentation and genetic diversity of an isolated population of the Blue-manakin, Chiroxiphia caudata (Pipridae), assessed by microsatellite analyses

Habitat fragmentation is predicted to restrict gene flow, which can result in the loss of genetic variation and inbreeding depression. The Brazilian Atlantic forest has experienced extensive loss of habitats since European settlement five centuries ago, and many bird populations and species are vanishing. Genetic variability analysis in fragmented populations could be important in determining their long-term viability and for guiding management plans. Here we analyzed genetic diversity of a small understory bird, the Blue-manakins Chiroxiphia caudata (Pipridae), from an Atlantic forest fragment (112 ha) isolated 73 years ago, and from a 10,000 ha continuous forest tract (control), using orthologous microsatellite loci. Three of the nine loci tested were polymorphic. No statistically significant heterozygote loss was detected for the fragment population. Although genetic diversity, which was estimated by expected heterozygosity and allelic richness, has been lower in the fragment population in relation to the control, it was not statistically significant, suggesting that this 112 ha fragment can be sufficient to maintain a blue-manakin population large enough to avoid stochastic effects, such as inbreeding and/or genetic drift. Alternatively, it is possible that 73 years of isolation did not accumulate sufficient generations for these effects to be detected. However, some alleles have been likely lost, specially the rare ones, what is expected from genetic drift for such a small and isolated population. A high genetic differentiation was detected between populations by comparing both allelic and genotypic distributions. Only future studies in continuous areas are likely to answer if such a structure was caused by the isolation resulted from the forest fragmentation or by natural population structure.

Colorimetric determination of ambient ozone using indigo blue droplet

A simple and sensitive method based on a liquid droplet is described for the measurement of atmospheric ozone. A 30 μL drop of indigo blue solution is suspended in a flowing-air sampling stream. The ozone collected reacts with the indigo solution resulting in its decolorization. The colorimetric sensor is composed of two optical fibers and the source of monochromatic light was a red LED (625 nm). The calibration curve was constructed with ozone standard concentrations ranging from 37 - 123 ppbv. The detection limit achieved was 7.3 ppbv. The method considered here showed itself to be easy to apply with a fast response and a total analysis time of only 5 minutes.

Carotid arteries in the dog: Structure and histophysiology

Light microscopy analysis of the mural structure of the common carotid artery, internal carotid artery and external carotid artery in mongrel dog revealed variability in the middle values of vascular diameter and thickness of the intimal plus medial coats and adventitial coat. The vascular diameter did not differ between the internal carotid artery and external carotid artery, but was significantly increased in the common carotid artery from which the other two arteries had origin. The increased thickness of the intimal plus medial coats of the common carotid artery revealed the constant mechanical adjustment of the arterial wall and local shearing stress that occurred among the arterial coats. The adventitial coat of the internal carotid artery was significantly thicker than those of the common carotid and external carotid arteries, with no significant difference noted between the latter arteries. These histomorphometric results were related to the qualitative observations regarding the mural structure of the three arteries analyzed, especially regarding to the increased thickness and structural complexity of the adventitial coat of the internal carotid artery. Perhaps it acted as an external protective sheath of the vascular wall during its long course until the carotid channel. © 2006 Sociedad Chilena de Anatomía.

Strategies for developing NADH detector based on meldola blue in different immobilization methods: A comparative study

A comparative study was accomplished between two immobilization methodologies for the meldola's blue (MB), used to decrease the oxidation potential of NADH. The study was performed with glassy carbon electrode by electropolymerization of pyrrole and MB through the technique of cyclic voltammetry being evaluated the effect of the number of cycles to define the thickness and the stability of the film. With 25 cycles it was obtained the best result. They were also investigated the modification of the graphite electrode with film formed by the system sol-gel PPO 300 or PPO 4000 for the dip-coating, through two methods: occlusion and adsorption. The best method was it of adsorption of MB during 10 min, following by deposit of the film PPO 300, favored for the time of drying (24 hours). The adsorption of MB followed by PPO 300 deposition presented broader linear range than PPy methodology. ©2006 Sociedade Brasileira de Química.

Toxoplasma gondii genotyping in a dog co-infected with distemper virus and ehrlichiosis rickettsia

This paper reports a toxoplasmosis, erhlichiosis and distemper co-infection in a dog with an exuberant neuropathological clinical picture. Primary involvement was discussed based on information collected in the analysis of the clinical case, such as neurological impairment, epidemiological data, poor immunoprophylactic scheme of the dog affected and the role of these diseases on immunosuppression. Canine distemper and ehrlichiosis were diagnosed based on epidemiologic data, clinical signs, hematological and cytological evaluation. Toxoplasma gondii was isolated and genetically characterized as Type I using restriction analysis (RFLP) with SAG-2 genes. Immunosuppression features of both dogs and human beings are discussed, as well as implications on animal and public health. This is the first report on toxoplasmosis, ehrlichiosis and distemper co-infection in a dog in Brazil, associated with genotyping determination of the T. gondii strain involved.

Decalcification dynamic of dog mineralized tissue by microwaves

The aim of this article is to present the decalcification process dynamic of mineralized tissue in dogs, teeth and jaw, comparing the traditional decalcification method, immersion, and microwave, immersion followed by irradiation using a domestic microwave oven, accompanying the liberation of calcium through spectrophotometer of atomic absorption. It was used as decalcified agent, EDTA solution or nitric acid. The results showed that with the use of nitric acid (5%), after 15 days, the irradiated fragments could be processed for histological analysis, otherwise the tooth not irradiated need to be submerged for 65 days. The EDTA decalcified action was slower than the nitric acid. The histological observations of the irradiated samples showed an excellent preservation of the morphological characteristics, independently of the decalcified agent used. © 2007 Sociedad Chilena de Anatomía.

Mesh skin graft and digital pad transfer to reconstruct the weight-bearing surface in a dog

A 2-month-old dog was presented with injuries involving both hind paws. Only the 5th digit and its digital pad were present on the right paw. Following a full-thickness skin graft, the 5th digital pad was transferred distal to the metatarsal bones. The transferred pad permitted weight-bearing on the limb.

Changes on degree of conversion of dual-cure luting light-cured with blue LED

The indirect adhesive procedures constitute recently a substantial portion of contemporary esthetic restorative treatments. The resin cements have been used to bond tooth substrate and restorative materials. Due to recently introduction of the self-bonding resin luting cement based on a new monomer, filler and initiation technology has become important to study the degree of conversion of these new materials. In the present work the polymerization reaction and the filler content of dual-cured dental resin cements were studied by means of infra-red spectroscopy (FT-IR) and thermogravimetry (TG). Twenty specimens were made in a metallic mold (8 mm diameter × 1 mm thick) from each of 2 cements, Panavia® F2.0 (Kuraray) and RelyX™ Unicem Applicap (3M/ESPE). Each specimen was cured with blue LED with power density of 500 mW/cm 2 for 30 s. Immediately after curing, 24 and 48 h, and 7 days DC was determined. For each time interval 5 specimens were pulverized, pressed with KBr and analyzed with FT-IR. The TG measurements were performed in Netzsch TG 209 under oxygen atmosphere and heating rate of 10°C/min from 25 to 700°C. A two-way ANOVA showed DC (%) mean values statistically significance differences between two cements (p < 0.05). The Tukey's test showed no significant difference only for the 24 and 48 h after light irradiation for both resin cements (p > 0.05). The Relx-Y™ Unicem mean values were significantly higher than Panavia® F 2.0. The degree of conversion means values increasing with the storage time and the filler content showed similar for both resin cements. © 2009 Pleiades Publishing, Ltd.

Occurrence and expression of p53 suppressor gene and c-Myc oncogene in dog eyelid tumors

Purpose: To detect the occurrence and expression of the suppressor gene p53 and of the oncogene c-Myc in eyelid tumors of dogs using the PCR, RT-PCR, PCR-ELISA and RT-PCR-ELISA techniques. These genes have not been described in dog eyelid tumors before. Methods: Nine samples of eyelid or third eyelid epithelial tumors were obtained from the archives of the Department of Veterinary Pathology. Tumor diagnosis was confirmed by evaluation of hematoxylin-eosin stained sections, and immunohistochemistry for cytokeratin AE1/AE3 and vimentin V9. A canine mammary tumor was used for positive control. Agarose gel electrophoresis, PCR-ELISA and RT-PCR-ELISA were used to detect p53 and c-Myc genes. Results: The occurrence of p53 was detected in most of the eyelid tumors and third eyelid tumors studied (88.8%, n = 8) and was expressed in 75% of the positive samples, as indicated by ELISA. The c-Myc gene was found in 77.7% (n = 7) of the samples and was expressed in eight samples. Conclusions: Eyelid and third eyelid tumors of dogs express both the p53 and the c-Myc genes as shown by PCR and RT-PCR. However, PCR ELISA and RT-PCR ELISA were more efficient in assessing occurrence and expression of these genes because they identified amplified products that were not detected by agarose gel electrophoresis. © 2010 American College of Veterinary Ophthalmologists.

Repair of bone cavities in dog's mandible filled with inorganic bovine bone and bioactive glass associated with platelet rich plasma

The aim of this study was to evaluate the effect of platelet rich plasma (PRP) associated to bovine inorganic bone (Bio-Oss®; Geistlich) or bioactive glass (Bio-Gran®; Orthovita, Implant Innovations) on bone healing. Bone cavities were prepared in both sides of the mandible of 4 adult male dogs. The cavities were divided into 4 groups according to the filling material as follows: control, PRP, PRP/Bio-Oss, PRP/Bio-Gran. The animals were sacrificed after 120 days and histological and histomorphometrical analysis was performed. The control group showed 80.6% of bone formation in the longitudinal sections at 6 mm depth and 83.7% at 13 mm depth. The transverse sections displayed 74.2% at both 6 and 13 mm depths. The PRP group showed 21.1% of bone formation in the longitudinal sections at 6 mm depth, and 23.1% at 13 mm depth. The transverse sections presented 28.98% of bone formation at 6 mm depth and 41.2% at 13 mm depth. The PRP/Bio-Gran group showed 25.1% of bone formation in the longitudinal sections at 6 mm depth and 30.4% at 13 mm depth. In the transverse sections, the bone formation was 43.0% at 6 mm depth and 39.7% at 13 mm depth. The PRP/Bio-Oss group showed 35.5% of bone formation in the longitudinal sections at 6 mm depth and 42% at 13 mm depth. In the transversal sections, the bone formation was 26.8% and 31.2% at the depths of 6 and 13 mm, respectively. PRP alone or associated with bovine inorganic bone or bioglass had no significant effect in bone healing.

Renal cell carcinoma with cutaneous metastasis in a dog

The present report describes the occurrence of skin metastasis in a dog with primary renal carcinoma. The clinical findings included progressive weight loss, inappetence, palpable abdominal mass and cutaneous nodules. The histopathological examination was carried out after unilateral nephrectomy and was confirmed by immunohistochemistry. The immunohistochemical and histopathological findings characterized this case as renal cell carcinoma with skin metastasis.

Implant osseointegration in circumferential bone defects treated with latex-derived proteins or autogenous bone in dog's mandible

Background: In sites with diminished bone volume, the osseointegration of dental implants can be compromised. Innovative biomaterials have been developed to aid successful osseointegration outcomes. Purpose: The aim of this study was to evaluate the osteogenic potential of angiogenic latex proteins for improved bone formation and osseointegration of dental implants. Materials and Methods: Ten dogs were submitted to bilateral circumferential defects (5.0×6.3mm) in the mandible. Dental implant (3.3×10.0mm, TiUnite MK3™, Nobel Biocare AB, Göteborg, Sweden) was installed in the center of the defects. The gap was filled either with coagulum (Cg), autogenous bone graft (BG), or latex angiogenic proteins pool (LPP). Five animals were sacrificed after 4 weeks and 12 weeks, respectively. Implant stability was evaluated using resonance frequency analysis (Osstell Mentor™, Osstell AB, Göteborg, Sweden), and bone formation was analyzed by histological and histometric analysis. Results: LPP showed bone regeneration similar to BG and Cg at 4 weeks and 12 weeks, respectively (p≥.05). Bone formation, osseointegration, and implant stability improved significantly from 4 to 12 weeks (p≤.05). Conclusion: Based on methodological limitations of this study, Cg alone delivers higher bone formation in the defect as compared with BG at 12 weeks; compared with Cg and BG, the treatment with LPP exhibits no advantage in terms of osteogenic potential in this experimental model, although overall osseointegration was not affected by the treatments employed in this study. © 2009 Wiley Periodicals, Inc.