Repair and Function of Synovium After Arthroscopic Synovectomy of the Dorsal Compartment of the Equine Antebrachiocarpal Joint

The reparative ability of equine synovium was determined by gross, histological, and ultrastructural examination. The functional potential of the synovium was estimated by examination of synovial cell organelles with transmission electron microscopy. Results from rested and exercised horses were compared to determine the effect of exercise on synovial healing. The response of the synovectomized joint to exercise was evaluated with a standardized lameness examination and by gross, histological, and histochemical observations of the articular cartilage. A 7-mm diameter motorized synovial resector was used to perform a subtotal synovectomy in 1 antebrachiocarpal joint of each of 8 horses; the contralateral joint served as a control. After 2 months rest, four randomly selected horses were rigorously exercised for the remainder of the study; the other four horses continued paddock rest. Lameness examinations and synovial fluid analyses were conducted at 0, 2, 30, 60, and 120 days. Synovium and articular cartilage from all horses were examined at necropsy at 120 days. None of the horses were lame during the study, and a transient synovitis occurred in the synovectomized joints. The hyaluronan concentration of treated joints decreased at 2 days but returned to normal by 60 days. Synovial fluid composition, including hyaluronan concentration, was unchanged by exercise. Significant cartilage damage was not observed in any of the joints. At 120 days, the healing synovium was devoid of villi and its subintima was fibrotic, however transmission electron microscopy confirmed that an intimal layer was present within the repair tissue. The cells within the repair tissue appeared actively engaged in both synthesis and phagocytosis. Exercise did not modify any of these findings. The results of this study suggest that 120 days after subtotal synovectomy, the joint environment was maintained and the resected synovium had evidence of restoration and increased metabolic potential. Synovectomized joints withstood exercise but synovial repair was not accelerated by exercise.     

ENLARGING BILATERAL FEMORAL CONDYLAR BONE CYSTS WITHOUT SCINTIGRAPHIC UPTAKE IN A YEARLING FOAL

Bilateral subchondral bone cysts of the femoral condyles were diagnosed by conventional radiography in a 14 month old Appaloosa colt. Surgical debridement was performed, and over the next 18 months the appearance of the cysts was evaluated with radiography and bone scintigraphy. On the preoperative scintigrams, increased radiopharmaceutical uptake was associated with the cysts. Despite continued radiographic enlargement, the cysts did not demonstrate increased radiopharmaceutical uptake post-operatively.     

Evaluation of 5 Types of Fishing Material, 2 Sterilization Methods, and a Crimp-Clamp System for Extra-Articular Stabilization of the Canine Stifle Joint

OBJECTIVE: To evaluate the mechanical properties of 5 types of fishing material, 2 sterilization methods, and a commercially designed crimp-clamp system for the extra-articular repair of the canine stifle joint. STUDY DESIGN: Experimental study. SAMPLE POPULATION: Animals were not used in this study. METHODS: Two brands of monofilament nylon fishing line and 3 brands of monofilament nylon leader line were used to determine the effect of steam and ethylene oxide sterilization on strength and elongation of the material. A strand of 36-kg test monofilament nylon fishing material was wrapped around 2 rods or knotted to form a loop around 2 rods on a materials-testing machine. Ten trials of each brand of unsterilized, steam-sterilized, and ethylene oxide-sterilized fishing material were tested. A strand of each material was elongated to failure at a constant displacement of 1,000 mm/min to determine strength. A strand of each material was cycled 10 times to a load of 50 N to determine percent elongation. The brand of fishing material with the greatest strength and least elongation was crimped to form a loop around 2 rods on a materials-testing machine and tested as described above. ANOVA was used to determine the effect of sterilization method, brand of material, knot, wrap, and crimp on strength and elongation of the material, and a post-hoc t test was used when significant differences were found. A Student t test was used to compare fixation techniques (wrap, knot, and crimp). RESULTS: Sterilization by steam or ethylene oxide had no significant effect on the strength of the nylon fishing material. Steam sterilization resulted in significant increases (2- to 4-fold) in elongation of most nylon fishing material when compared with unsterilized material. Ethylene oxide sterilization had minimal effect on elongation of the fishing material. Mason leader line showed no significant change in strength or elongation regardless of sterilization method. Significantly less strength and significantly less elongation were demonstrated in Mason leader line that was crimped as compared with Mason leader line that was knotted. CONCLUSION: Ethlylene oxide was the preferred method of sterilization to preserve strength and minimize elongation of the fishing material. Of the materials tested, Mason leader line had the least elongation and the greatest preservation of strength when ethylene oxide was used as the sterilization method. Mason leader line and Sufix fishing line were comparable choices when steam was used as the sterilization method. Significantly less elongation was demonstrated in crimped Mason leader line as compared with knotted Mason leader line. CLINICAL RELEVANCE: Of the materials tested, Mason leader line and Sufix fishing line had the best mechanical properties for extracapsular stabilization of the canine stifle joint. Crimping is an attractive alternative to knotting and results in a reduction in elongation of the nylon fishing material.     

The cardiopulmonary effects of romifidine in dogs with and without prior or concurrent administration of glycopyrrolate

Objective To determine the electrocardiographic and cardiopulmonary effects of romifidine with and without prior or concurrent administration of glycopyrrolate. Study design Randomized crossover experimental study. Animals Six (three male, three female) cross‐bred dogs weighing 23 ± 2.4 kg. Methods Baseline cardiopulmonary measurements were obtained in conscious dogs and one of five treatments was administered. Glycopyrrolate (G) 0.01 mg kg^?1, or saline (S) 0.5 mL, were administered IM as premedication (Gp or Sp), or G was administered concurrently (Gc) with romifidine (RO). Treatments were as follows T1, Sp + RO 40 µg kg^?1; T2, Gp + RO (40 µg kg^?1); T3, Sp + RO 120 µg kg^?1; T4, Gp + RO (120 µg kg^?1); T5, Sp + Gc + RO (120 µg kg^?1). Romifidine or RO + Gc was administered subcutaneously 20 minutes after premedication (time 0), and further measurements were taken 10, 20, 30, 60 and 90 minutes after RO. The main treatment effect was evaluated using two‐way anova for repeated measures, followed by one‐way anova and a post‐hoc least squares difference test with a modified Bonferroni correction (p < 0.02). A Student's t‐test was used to compare the effect of romifidine at 20 and 60 minutes versus baseline values (p < 0.05). Results Both low‐ and high‐dose RO (T1, T3) significantly decreased heart rate (HR), respiratory rate (RR), cardiac index (CI) and stroke volume index, and increased arterial blood pressure (SAP), systemic vascular resistance (SVR), pulmonary arterial occlusion pressure (PAOP) and central venous pressure. High‐dose RO produced greater increases in SVR and SAP measurements. Neither dose of RO produced an alteration in blood gas values or the alveolar to arterial oxygen gradient. Glycopyrrolate significantly increased HR and CI from 10 to 90 minutes between T1/T2 and T3/T4. Increases in SAP were dose related with significant differences between T1/T3 and T2/T4 at 90 and 10 minutes, respectively, and were highest in animals receiving Gp or Gc. High‐dose RO groups (T3, T4) had higher values for SVR than low‐dose RO groups (T1, T2), unrelated to G administration. There was an increase in PAOP in all treatments. The oxygen extraction ratio was increased with all treatments: larger increases were observed in T1, T3 and T4 compared with only minimal changes in T2. Concurrent G administration was associated with an increased frequency of high‐grade second‐degree atrioventricular heart block with variable conduction at 10 and 20 minutes. Conclusions Romifidine produced effects consistent with other selective α₂‐adrenoreceptor agonists. Glycopyrrolate offset the decrease in HR and partially offset the decrease in CI associated with RO administration. Glycopyrrolate premedication produced an initial tachycardia and added to the increase in SAP associated with RO. Concurrent G administration was associated with a higher frequency of dysrhythmias and is not recommended. Despite the decrease in RR, RO sedation did not alter blood gas values. Clinical relevance It appears likely that G administration prior to or concurrent with RO produces an increase in myocardial workload and oxygen demand suggesting that this combination should not be used in dogs with cardiomyopathy or heart failure. The improvement in oxygen extraction ratio with T2 suggests that G may be beneficial with lower doses of RO, nevertheless, the use of G and RO in cardiovascularly compromised patients is not advised.     

Land Cover Transition in Northern Tanzania

Land conversion in sub‐Saharan Africa has profound biophysical, ecological, political and social consequences for human well‐being and ecosystem services. Understanding the process of land cover changes and transitions is essential for good ecosystem management policy that would lead to improved agricultural production, human well‐being and ecosystems health. This study aimed to assess land cover transitions in a typical semi‐arid degraded agro‐ecosystems environment within the Pangani river basin in northern Tanzania. Three Landsat images spanning over 30 years were used to detect random and systematic patterns of land cover transition in a landscape dominated by crop and livestock farming. Results revealed that current land cover transition is driven by a systematic process of change dominated by the following: (i) transition from degraded land to sparse bushland (10·8%); (ii) conversion from sparse bushland to dense bushland in lowland areas (6·0%); (iii) conversion from bushland to forest (4·8%); and (iv) conversion from dense bushland to cropland in the highlands (4·5%). Agricultural lands under water harvesting technology adoption show a high degree of persistence (60–80%) between time slices. This suggests that there is a trend in land‐use change towards vegetation improvement in the catchment with a continuous increase in the adoption of water harvesting technologies for crop and livestock farming. This can be interpreted as a sign of agricultural intensification and vegetation regrowth in the catchment. Copyright © 2015 John Wiley & Sons, Ltd.     

Monitoring of blood vessels and tissues by a population of monocytes with patrolling behavior

The cellular immune response to tissue damage and infection requires the recruitment of blood leukocytes. This process is mediated through a classical multistep mechanism, which involves transient rolling on the endothelium and recognition of inflammation followed by extravasation. We have shown, by direct examination of blood monocyte functions in vivo, that a subset of monocytes patrols healthy tissues through long-range crawling on the resting endothelium. This patrolling behavior depended on the integrin LFA-1 and the chemokine receptor CX(3)CR1 and was required for rapid tissue invasion at the site of an infection by this "resident" monocyte population, which initiated an early immune response and differentiated into macrophages.     

Measurement of the Motion of Fertilizer Particles Leaving a Centrifugal Spreader Using a Fast Imaging System

Although mechanically simple, centrifugal spreaders used for mineral fertilization involve complex physics that cannot be fully characterized at the present time. We are developing sensors to evaluate the spatial distribution of the fertilizer on the ground based on the measurement of initial flight conditions of fertilizer granules after their ejection by the spreading disk. The techniques developed are based on the analysis of images of the area around the disk showing the granule ejection. A high resolution – low cost imaging system for the analysis of high speed particle projection developed for this specific purpose is presented in this paper. The system, based on a camera and a sequence of flashes, is used to characterize the centrifugal spreading of fertilizer particles ejected at speeds of approximately 30ms^–1. It automatically computes the direction of ejection and velocity of each granule observed in the image. Multi-exposure images collected with the camera installed perpendicular to the output flow of granules are analyzed to estimate the trajectories of the fertilizer granules, using different motion estimation methods.     

The Effects of Mx1 Locus on Immunity Tracts Components in Large White×Meishan F2 Offspring

The mouse Myxovirus resistance protein 1 (Mx1) is known to be sufficient to confer resistance to influenza viruses, and genes encoding Myxovirus resistance protein 1 (Mx1) is, therefore, an interesting candidate gene for disease resistance in farm animals. The porcine Mxl gene has already been identified and characterized based on its homology with mouse Mxl; the full-length coding region of the pig Mxl gene spans 2 545 bp (M65087) and is organized into 17 exons compared with the human ortholog mRNA. In this study, the exons 9, 10, 11 and introns 6, 9 of the porcine Mxl gene were cloned and sequenced; two SNPs were identified in exons 9, 10, 11 but none of the SNPs led to an amino acid exchange, and the other eleven variants were detected in introns 6 and 9, respectively. Differences in allele frequency among Meishan, Large White, Tibetan, Tongcheng, Huainan, and Duroc pigs were observed within intron 9, of which an A → G substitution at position 186 was detected as an Msp Ⅰ PCR-restriction fragment length polymorphism (PCR-RFLP). The association analysis using the Large White×Meishan F2 offspring suggested that the Mxl genotype was associated with variation in several immunity traits that are of interest in pig breeding. However, further investigations in more populations are needed to confirm the above concept.     

A cost of long-term memory in Drosophila

Two distinct forms of consolidated associative memory are known in Drosophila: long-term memory and so-called anesthesia-resistant memory. Long-term memory is more stable, but unlike anesthesia-resistant memory, its formation requires protein synthesis. We show that flies induced to form long-term memory become more susceptible to extreme stress (such as desiccation). In contrast, induction of anesthesia-resistant memory had no detectable effect on desiccation resistance. This finding may help to explain why evolution has maintained anesthesia-resistant memory as another form of consolidated memory, distinct from long-term memory.     

Comparative genomics of trypanosomatid parasitic protozoa

A comparison of gene content and genome architecture of Trypanosoma brucei, Trypanosoma cruzi, and Leishmania major, three related pathogens with different life cycles and disease pathology, revealed a conserved core proteome of about 6200 genes in large syntenic polycistronic gene clusters. Many species-specific genes, especially large surface antigen families, occur at nonsyntenic chromosome-internal and subtelomeric regions. Retroelements, structural RNAs, and gene family expansion are often associated with syntenic discontinuities that-along with gene divergence, acquisition and loss, and rearrangement within the syntenic regions-have shaped the genomes of each parasite. Contrary to recent reports, our analyses reveal no evidence that these species are descended from an ancestor that contained a photosynthetic endosymbiont.