Effects of subsurface aeration and trinexapac-ethyl application on soil microbial communities in a creeping bentgrass putting green

The sensitivity of creeping bentgrass (Agrostis palustris Huds.) to the extreme heat found in the southeastern United States has led to the development of new greens-management methods. The purpose of this study was to examine the effects of subsurface aeration and growth regulator applications on soil microbial communities and mycorrhizal colonization rates in a creeping bentgrass putting green. Two cultivars (Crenshaw and Penncross), a growth regulator (trinexapac-ethyl), and subsurface aeration were evaluated in cool and warm seasons. Total bacterial counts were higher in whole (unsieved) soils than in sieved soils, indicating a richer rhizosphere soil environment. Mycorrhizal infection rates were higher in trinexapac-ethyl (TE) treated plants. High levels of hyphal colonization and relatively low arbuscule and vesicle occurrence were observed. Principal components analysis of whole-soil fatty acid methyl ester (FAME) profiles indicated that warm-season microbial populations in whole and sieved soils had similar constituents, but the populations differed in the cool season. FAME profiles did not indicate that subsurface aeration and TE application affected soil microbial community structure. This is the first reported study investigating the influences of subsurface aeration and TE application on soil microorganisms in a turfgrass putting green soil.     

Placebo-controlled blinded study of postoperative pain therapy with carprofen and levomethadone in dogs with fractures

It was the aim of this placebo-controlled study to evaluate the analgesic efficacy of the NASAID carprofen and the pure m-agonist levomthadone over a five-day postoperative evaluation period in dogs with fractures of the humerus or the femur (n = 30). Pain and sedation evaluation was carried out with a visual analogues system (VAS) and with the aid of a numerical estimation scale(NRS). The degree of lameness, the pain treshhold, the glucose and cortisol concentration curves as well as the respiration and heart rate and the systolic blood pressure were used as further pain indicators and to identify drug side effects. The levomethadon group displayed the lowest degree of pain on postoperative examination on the first day. On days 2 to 5, the carprofen group showed the lowest degree of pain in comparison to the placebo group. The levomethadon- and the carprofen group showed no statistically proven differences from day 2 on. Due to great variations in the pain scores and comparatively high median pain score especially on the first day of this study, the efficacy of all analgesics evaluated here must be regarded as insufficient in many cases. Only the parameter nociceptive pain treshhold showed a little, the degree of lameness, the glucose and cortisol levels showed no close correlation to the VAS and NRS pain scores and were therefore of little usefulness as postoperative pain indicators. No relevant clinical side effects caused by the used analgesics were detected in the kidney, the liver, the gastrointestinal tract and the circulatory system in this study. Rather, traumatically induced elevation of enzyme levels improves or normalised until the 5th day of the study. In addition, no negative effect on wound healing was noted, especially for carprofen. Therefore, the evaluated analgesics seems to be adequate for postoperative pain therapy also in fracture patients (trauma patients). However, the efficacy of all analgesics evaluated here must be regarded as insufficient in many cases.     

Tension band stabilization of fractures and luxations of the thoracolumbar vertebrae in dogs and cats: 38 cases (1993-2002)

OBJECTIVE: To determine the outcome of dogs and cats in which a tension band technique was used to stabilize traumatic fractures and luxations of the thoracolumbar vertebrae. DESIGN: Retrospective study. ANIMALS: 38 client-owned animals (22 dogs and 16 cats) weighing between 1.4 and 45 kg (3 and 99 lb). PROCEDURE: Medical records of cats and dogs that underwent tension band stabilization of thoracolumbar fractures and luxations at the University of Zurich between 1993 and 2002 were reviewed. The stabilization technique was a modification of a spinal stapling technique with a figure 8 hemicerclage wire placed in a tension band fashion across the lesion. Neurologic status, lesion location and type, and concomitant traumatic injuries were assessed from the medical records and preoperative radiographs. Clinical outcome and complications were determined through follow-up examinations or telephone conversations with the owners. RESULTS: Complete or satisfactory neurologic recovery was achieved in 30 (79%) patients. Seven patients were euthanatized (6 owing to poor neurologic recovery and 1 owing to implant failure), and 1 dog was managed at home despite paraplegia. Clinically, only 4 patients (11%) had evidence of implant or fixation failure; all were dogs weighing > 16 kg (35 lb). CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that the tension band technique may be appropriate for stabilization of fractures and luxations of the thoracolumbar vertebrae in cats and small- or medium-sized dogs. In larger dogs, fixation strength may be insufficient to stabilize certain fracture types and ancillary external or internal fixation methods may be needed.     

Minimally invasive synovium harvest for potential use in meniscal tissue engineering

Tissue engineering is being investigated as a means for treating avascular meniscal injury or total meniscal loss in human and veterinary patients. The purpose of this study was to determine if an arthroscopic tissue shaver can be used to collect viable synoviocytes for in vitro culture during therapeutic stifle arthroscopy, with the long term goal of producing autologous meniscal fibrocartilage for meniscal tissue engineering. Synovium was harvested arthroscopically from 13 dogs with naturally occurring cranial cruciate ligament deficiency and obtained from 5 dogs with patellar luxation via arthrotomy. Cells harvested via arthroscopy and arthrotomy were treated with a chondrogenic growth factor protocol and analyzed for meniscal-like matrix constituents including collagens type I, II, and glycosaminoglycans. Arthrotomy and Arthroscopic origin cells formed contracted tissues containing collagen I, II and small amounts of GAG. These surgical methods provide clinically relevant access to synoviocytes for potential use in meniscal tissue engineering.     

Cardiac troponin I and the occurrence of cardiac arrhythmias in horses with experimentally induced endotoxaemia

Branding is the traditional and well-established method used to mark horses, but recently microchip transponders for implantation have become available. In this study, behaviour, physiological stress variables and skin temperature in foals were determined in response to hot-iron branding (n=7) and microchip implantation (n=7). Salivary cortisol concentrations increased in response to branding (1.8 ± 0.2 ng/mL) and microchip implantation (1.4 ± 0.1ng/mL), but cortisol release over time did not differ. In response to both manipulations there was a transient increase in heart rate (P<0.001) and heart rate variability (P<0.01). Branding and microchip implantation induced a comparable aversive behaviour (branding, score 3.86 ± 0.85; microchip, score 4.00 ± 0.82). Both techniques thus caused similar physiological and behavioural changes indicative of stress. Acutely, implantation of a microchip was as stressful as branding in foals. Branding caused a necrotising skin burn lasting at least 7 days. Moreover branding, but not microchip implantation (P<0.001), was accompanied by a generalized increase in skin temperature which was comparable to low degree post-burn hypermetabolism in humans.     

Probable lumbar acute non-compressive nucleus pulposus extrusion in a cat with acute onset paraparesis

A spinal cord lesion localised caudal to the L6 spinal segment was diagnosed in a 2-year-old female spayed domestic longhair cat with acute onset paraparesis. Magnetic resonance imaging findings were consistent with an acute, non-compressive nucleus pulposus extrusion of the L5-L6 intervertebral disc. The cat was successfully managed with supportive care, including cage confinement.     

Carcinogenicity of acrylamide: a computational study

This paper reports a series of ab initio, density functional theory (DFT), and semiempirical molecular orbital (MO) calculations concerning the reaction between the ultimate carcinogen of acrylamide and guanine. Acrylamide--a product of the Maillard reaction--is present in a variety of fried and oven-cooked food. After intake, it is epoxidized by cytochrome P450 2E1 to yield the ultimate carcinogen--glycidamide. Effects of solvation were considered using the Langevin dipoles (LD) model of Florian and Warshel and the solvent reaction field (SCRF) model of Tomasi and co-workers. In silico activation free energies are in very good agreement with the experimental value of 22.8 kcal/mol. This agreement presents strong evidence in favor of the validity of the proposed S N2 reaction mechanism and points to the applicability of quantum chemical methods to studies of reactions associated with carcinogenesis. In addition, insignificant stereoselectivity of the studied reaction was predicted. Finally, the competing reaction of glycidamide with adenine was simulated, and the experimentally observed regioselectivity was successfully reproduced.     

Allochrony as a potential driver for reproductive isolation in adaptive radiations of European whitefish ecomorphs

In northern Fennoscandian lakes, monophylogenetic lineages of postglacial fishes are radiating into several adaptive forms, but the speciation process is still at an incipient stage. The speciation process has received increased attention over the years, but the underlying mechanisms and drivers are still debated and poorly understood. European whitefish (Coregonus lavaretus [L.]) is the most abundant fish species in these lakes and has evolved into several ecomorphs adapted to different trophic niches and habitats. Genetic divergence has been observed among these ecomorphs, but the mechanism(s) responsible for the ongoing build-up of reproductive isolation has still to be revealed. As these systems are young in evolutionary time (<10 kyr), prezygotic and postzygotic extrinsic isolation mechanisms are thought to be more likely to contribute to the reproductive isolation than intrinsic isolation mechanisms. We determined the gonadosomatic index (GSI) of three ecomorphs in two replicated lake systems and used GSI as a proxy to investigate the prezygotic isolation mechanism, allochrony, as a driving factor of divergence in this adaptive radiation of whitefish. We found that the three ecomorphs differed in GSI values within and between lakes, suggesting different spawning times of the ecomorphs. We also show that males of one ecomorph had equal onset of maturity as another ecomorph, giving novel insights into the ongoing gene flow observed between ecomorphs. The result supports allochrony as a driver for the divergence process of whitefish ecomorphs, but more evidence is still needed to rule out that the three ecomorphs make use of different spawning grounds.