Detection of Escherichia coli strains producing cytotoxic necrotizing factor type two (CNF2) by enzyme-linked immunosorbent assay

Sheep and rabbit antisera were produced against lysates of E. coli strain 711 (pVir). This K-12 strain carries the Vir plasmid which codes for Cytotoxic Necrotizing Factor type 2 (CNF2). Immunoglobulin G (IgG) fractions of both immune sera were subsequently purified by a two-step precipitation method. To increase the specificity for CNF2, the sheep IgG preparation was extensively adsorbed against both a sonicated extract of isogenic K-12 strain 711 and intact phenol-treated cells of vaccine strain 711 (pVir). An enzyme-linked immunosorbent assay (ELISA) was developed to detect clinical isolates of E. coli producing CNF2, using the final preparations of rabbit and sheep IgG in a double sandwich technique. The results obtained with this CNF2-ELISA were compared to those obtained with the conventional HeLa cell cytotoxicity assay. The testing of 133 E. coli strains (49 CNF2 positive strains and 84 negative strains) resulted in no false-negative and no false-positive. Therefore, the CNF2-ELISA offers a good alternative to the HeLa cell culture assay for the detection of CNF2-producing strains where facilities for and experience with cell cultures is lacking.     

Pharmaceutical and nutraceutical management of canine osteoarthritis: present and future perspectives

Osteoarthritis (OA) is one of the most common chronic musculoskeletal diseases and causes of lameness in the dogs. The osteoarthritic disease process involves the entire synovial joint, encompassing the synovium, cartilage and underlying bone. Joint failure results from an abnormal mechanical strain causing damage to normal tissue or failure of pathologically impaired articular cartilage and bone under the influence of normal physiological strain or a combination of both. In both cases, the end point is cartilage loss and joint impairment. Osteoarthritic chondrocytes show an altered phenotype characterised by an excess production of catabolic factors, including metalloproteinases and reactive oxygen species. These factors constitute potential therapeutic targets and some new drugs and nutraceuticals have been proposed to promote the return to homeostasis. Until now, the therapeutic management of OA in dogs has been dominated by nonsteroidal anti-inflammatory drugs, but some new compounds, including diacerhein, with potential structure-modifying effects, are already used to treat OA in humans and could be helpful to manage OA in the dog. In addition, novel nutraceuticals, such as avocado/soybean unsaponifiable substances, have shown symptomatic effects in knee OA in humans, and could offer an alternative to prevent OA progression. This paper provides an overview of recent discoveries in the pathophysiology and in the therapeutic management of osteoarthritis in dogs.     

Airway management under general anaesthesia in pigs using the LMA-ProSeal: a pilot study

OBJECTIVE: Evaluation of the LMA-ProSeal for positive pressure ventilation (PPV) in the pig. STUDY DESIGN: Prospective observational study. ANIMALS: Twelve German country pigs, weighing 25-62 kg. METHOD: Lungs of pigs were mechanically ventilated under general anaesthesia using the LMA-ProSeal. The ease of insertion, number of attempts and total time until placement of the LMA-ProSeal and gastric tube were recorded. Bronchoscopy was performed to determine the position of the LMA-ProSeal and to detect signs of aspiration. Ventilation variables and the leak airway pressure (P(leak)) were measured. An arterial blood gas sample was taken to determine the adequacy of ventilation. RESULTS: The airway was secured in all pigs within 39 +/- 19 seconds (27-51). Different sizes of LMA-ProSeal were used; up to 30 kg: size 3, up to 43 kg: size 4; and above 43 kg: size 5. In all but one animal the P-LMA and gastric tube were inserted at the first attempt. In nine animals gastric fluid was drained through the gastric tube. There was no evidence of aspiration in any animal. The mean [+/-SD (95%CI)]P(leak) was 28.8 +/- 7.5 cm H(2)O (24.06-33.60) and normal ventilation was achieved in all animals. CONCLUSIONS: The results of this study indicate that the airway of pigs weighing 25-62 kg can be secured safely and reliably with the sizes 3, 4 and 5 LMA-ProSeal. CLINICAL RELEVANCE: Endotracheal intubation in pigs can be difficult so there is a risk of hypoxemia in the apnoeic animal. With the LMA-ProSeal the airway can be secured rapidly, safely and reliably. Use of the Standard-LMA under PPV can be associated with gas leakage into the stomach and the subsequent risk of gastric distension and regurgitation. Both the ability to drain the stomach and the high P(leak) of the LMA-ProSeal could contribute to improved protection against aspiration under PPV.     

Integrating Fire Risk Considerations in Forest Management Planning in Spain – A Landscape Level Perspective

It is reasonable to assume that there is a relationship between the spatial distribution of forest fuels and fire hazards. Therefore, if fire risk is to be included into numerical forest planning, the spatial distribution of risky and non-risky forest stands should be taken into account. The present study combines a stand-level fire risk model and landscape level optimization to solve forest planning problems in which the fire risk plays an important role. The key point of the method was to calculate forest level fire resistance metrics from stand level indices and use these metrics as objective variables in numerical optimization. This study shows that maximizing different landscape metrics produces very different landscape configurations with respect to the spatial arrangement of resistant and risky stands. The landscapes obtained by maximizing different metrics were tested with a fire spread simulator. These tests suggested that the mean fire resistance of the landscape, which is a non-spatial metric, is the most important factor affecting the burned area. However, spatial landscape metrics that decrease the continuity of fire resistance in the landscape can significantly improve the fire resistance of the landscape when used as additional objective variables.     

The Role of Saprotrophy and Virulence in the Population Dynamics of Botrytis cinerea in Vineyards

ABSTRACT Change in relative frequencies of the three main genetic types of Botrytis cinerea (Group I, Group II vacuma, and Group II transposa) were monitored over time from 1998 to 2000 in three Bordeaux vineyards not treated with fungicides. During 2000, Group I isolates, detected mostly at flowering comprised only 2.5% of the entire population. Within Group II, the complementary frequencies of vacuma and transposa isolates differed significantly depending on grapevine phenological stages and organs. Every year and at all sites, including one noble rot site, transposa isolates dominated at every stage, particularly on overwintering canes and at harvest (greater than 86.7% on berries). The complementary frequency of vacuma isolates reached a maximum on senescing floral caps (between 23.5 and 71.4%) and then decreased significantly until harvest on leaves and berries. In pathogenicity tests on grape berries, transposa isolates were significantly more virulent than were vacuma isolates. Mycelial growth rate was negatively correlated with virulence, notably on leaves in transposa and with double resistance to the fungicides carbendazim and vinclozolin. In vacuma, this double resistance was positively correlated with virulence on leaves. Change in the vacuma and transposa frequencies was most likely caused by differences in saprotrophic and pathogenic fitness. Possible interactions between fungicide resistance profiles and fitness are discussed.     

Factors associated with fusarium crown and root rot of asparagus outbreaks in quebec

ABSTRACT The Fusarium spp. causing Fusarium crown and root rot (FCRR) are ubiquitous and abundant in soils, but in contrast, disease expression is localized and sporadic. Previous studies have related FCRR infection to phenolic acids released by asparagus, to the repression of Mn-reducers in soil, and to various soil physicochemical conditions. Fifty commercial asparagus plantations were surveyed using an exploratory approach in order to pinpoint the ecological conditions associated with FCRR development. Twenty-eight variables were used to describe the soil environments of the asparagus crops as well as the influence of crop management practices used locally. The data set was analyzed both as a whole and parsed by main cultivars (Jersey Giant and Guelph Millenium). Both field conditions and percentage of field area affected by FCRR varied widely between asparagus plantations. Planting depth was positively correlated with percentage of field area affected by FCRR and, hence, deep planting may favor FCRR infection. Plantation age was positively correlated with percentage of field area affected by FCRR, while soil available Mn was inversely correlated. Most importantly, soil Mn availability decreased with increasing plantation age, supporting the hypothesis of an asparagusmediated negative impact on Mn-reducing bacteria and of the involvement of reduced Mn availability in FCRR development. Improving the availability of Mn could provide a solution to the problem of FCRR in asparagus plantations.     

Use of hinged transarticular external fixation for adjunctive joint stabilization in dogs and cats: 14 cases (1999-2003)

OBJECTIVES: To describe placement of hinged transarticular external fixation (HTEF) frames and evaluate their ability to protect the primary repair of unstable joints while allowing joint mobility in dogs and cats. DESIGN: Retrospective study. ANIMALS: 8 cats and 6 dogs. PROCEDURE: HTEF frames were composed of metal or epoxy connecting rods and a hinge. Measurements of range of motion of affected and contralateral joints and radiographs were made after fixator application and removal. RESULTS: 9 animals (4 cats and 5 dogs) had tarsal and 5 (4 cats and 1 dog) had stifle joint injuries. Treatment duration ranged from 45 to 100 days (median, 57 days). Ranges of motion in affected stifle and tarsal joints were 57% and 72% of control while HTEF was in place and 79% and 84% of control after frame removal. Complications were encountered in 3 cats and 2 dogs and included breakage of pins and connecting rods, hinge loosening, and failure at the hinge-epoxy interface. CONCLUSIONS AND CLINICAL RELEVANCE: HTEF in animals with traumatic joint instability provided adjunctive joint stabilization during healing and protection of the primary repair and maintained joint motion during healing, resulting in early weight bearing of the affected limb.     

Spontaneous resolution of iatrogenic chylothorax in a cat

Chylothorax is an uncommon condition of dogs and cats defined by the accumulation of chylous effusion within the pleural space. Chylothorax has been experimentally created in dogs and cats by ligation of the cranial vena cava and has been reported to occur spontaneously in dogs with naturally occurring obstruction of the cranial vena cava. In the cat of this report, iatrogenic chylothorax was caused by surgical ligation and transection of the left brachiocephalic vein during a tracheal resection and anastomosis procedure. The chylous effusion resolved with medical management 9 weeks after surgery.