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A grazing experiment was conducted to assess the effects of wild-type endophyte-infected (E+) tall fescue consumption and elevated ambient temperatures on intravaginal temperatures, plasma lipid peroxidation, and glutathione redox of peripheral blood mononuclear cells. Angus heifers (n = 34) were allotted by BW to 4 blocks consisting of E+ and endophyte-free (E−) fescue pastures. Monthly, in June, July, and August, temperature loggers were fixed into blank controlled internal drug releasers and inserted into a subsample of heifers (n = 16) for 2 d. After 48 h, heifers were weighed, and blood (30 mL) was collected via jugular venipuncture. Peripheral blood mononuclear cells were isolated for analysis of glutathione peroxidase activity, glutathione reductase activity, and reduced:oxidized glutathione. Plasma malondialdehyde was evaluated as a marker of lipid peroxidation, and whole blood Se concentration was determined. Serum prolactin was assayed after the grazing period. Heifer ADG was greatest in August and least in July (P< 0.001). In August, heifers grazing E+ fescue exhibited greater (P< 0.05) afternoon intravaginal temperatures and temperature fluctuations than heifers grazing E− fescue. In July and August, all heifers had greater afternoon temperatures (P< 0.02) and less reduced:oxidized glutathione (P< 0.0001) than in June. Glutathione reductase activity of all heifers was greater in June (P= 0.03) than in July. Similarly, all heifers exhibited decreased glutathione peroxidase activity (P< 0.0008) in July, whereas whole blood Se was reduced (P< 0.0001) in July and August. No treatment or date effects were detected for malondialdehyde, but serum prolactin was reduced at the end of the grazing period (P= 0.008) in heifers stocked on E+ fescue. Using these markers, differences in oxidative stress were not detected between heifers consuming E+ fescue and those consuming E− fescue. Date effects indicating altered glutathione redox and enzyme activity may have been related to heat stress and nutritional limitations.

This study tested the development of oxidative stress and the effects of antioxidant supplementation in an 80-km ride. A precompetition survey revealed that no competitor would participate without vitamin E supplementation; therefore, 46 horses were paired for past performances and randomly assigned to two groups of 23 each for 3 wk of supplementation before the ride. One group (E) was orally supplemented with 5,000 IU of vitamin E per day; the other group (E+C) received that dose of vitamin E plus 7 g/d of vitamin C. Blood samples, temperature, and heart rate were taken the day before the race, at 21 and 56 km during the ride, at completion, and after 20 min of recovery. Plasma was assayed for lipid hydroperoxides, α-tocopherol, total ascorbate, albumin, creatine kinase (CK), and aspartate aminotransferase (AST). Total glutathione and glutathione peroxidase activity were determined in red blood cells and white blood cells. Thirty-four horses completed the race, 12 horses (six in E and six in E+C) did not finish for reasons including lameness, metabolic problems, and rider option. Plasma ascorbate was higher (P= 0.045) in the E+C group than in the E group. Other than ascorbate, neither antioxidant status nor CK and AST activities were affected by supplementation with E+C vs. E. Red blood cell glutathione peroxidase, white blood cell total glutathione, lipid hydroperoxides, CK, and AST increased, and red blood cell total glutathione and white blood cell glutathione peroxidase activity decreased with distance (P< 0.001). Positive correlations were found for plasma lipid hydroperoxides on CK (r = 0.25; P= 0.001) and AST (r = 0.33; P< 0.001). These results establish an association between muscle leakage and a cumulative index of oxidative stress.

Abstract.:  The use of GPS for height control in an area with existing levelling data requires the determination of a local geoid and the bias between the local levelling datum and the one implicitly defined when computing the local geoid. If only scarse gravity data are available, the heights of new data may be collected rapidly by determining the ellipsoidal height by GPS and not using orthometric heights. Hence the geoid determination has to be based on gravity disturbances contingently combined with gravity anomalies. Furthermore, existing GPS/levelling data may also be used in the geoid determination if a suitable general gravity field modelling method (such as least-squares collocation, LSC) is applied. A comparison has been made in the Aswan Dam area between geoids determined using fast Fourier transform (FFT) with gravity disturbances exclusively and LSC using only the gravity disturbances and the disturbances combined with GPS/levelling data. The EGM96 spherical harmonic model was in all cases used in a remove–restore mode. A total of 198 gravity disturbances spaced approximately 3 km apart were used, as well as 35 GPS/levelling points in the vicinity and on the Aswan Dam. No data on the Nasser Lake were available. This gave difficulties when using FFT, which requires the use of gridded data. When using exclusively the gravity disturbances, the agreement between the GPS/levelling data were 0.71 0.17 m for FFT and 0.63 0.15 for LSC. When combining gravity disturbances and GPS/levelling, the LSC error estimate was 0.10 m. In the latter case two bias parameters had to be introduced to account for a possible levelling datum difference between the levelling on the dam and that on the adjacent roads.

Tall fescue (Festuca arundinaceaSchreb.) infected with the endophyte Neotyphodium coenophialum([Morgan-Jones and Gams] Glenn, Bacon, and Hanlin) causes fescue toxicosis in cattle grazing the forage, but effects of the endophyte were considered to be abated soon after removal of the animals from pastures. Tasco-Forage, a proprietary extract from the brown seaweed Ascophyllum nodosum, is a known source of cytokinins and has increased antioxidant activity in both plants and the animals that graze the forage. Tasco was applied at 0 and 3.4 kg/ha to infected and uninfected tall fescue pastures in Virginia and Mississippi. Forty-eight steers grazed the pastures at each location during each of 2 yr (n = 192) before being transported to Texas for feedlot finishing. On arrival at the feedlot, steers from Tasco-treated pastures had higher (P< 0.01) monocyte phagocytic activity and tended (P< 0.07) to have higher major histocompatibility complex class II expression than steers that grazed the untreated pastures. A depression (P< 0.05) in monocyte immune cell function due to grazing infected fescue was detected throughout the feedlot finishing period but was reversed by Tasco. Rectal temperatures were elevated (P< 0.07) in steers that had grazed the infected tall fescue when they arrived in Texas, but by d 14 no difference was detected. However, by d 28 the temperature effects of infected tall fescue were reversed. Steers that had grazed infected fescue had lower (P< 0.01) rectal temperatures on d 112 of the feedlot period, demonstrating a much longer-lasting effect of the endophyte on thermoregulatory mechanisms than previously thought. Steers that had grazed Tasco-treated pastures had higher (P< 0.01) rectal temperatures on d 56 than steers that had grazed untreated fescue. Steers that had grazed the Tasco-treated pastures had higher marbling scores (P< 0.05) regardless of the endophyte, but no effect of Tasco or endophyte on gain was measured. Our data suggest that Tasco application to tall fescue pastures alleviated some of the negative effects of tall fescue toxicity.

Effects of applying Tasco-Forage, an Ascophyllum nodosum seaweed-based product prepared by a proprietary process, to endophyte (Neotyphodium coenophialum [Morgan-Jones and Gams] Glenn, Bacon, and Hanlin)-infected and endophyte-free tall fescue (Festuca arundinacea Schreb.) were studied in each of 3 yr (1995, 1996, and 1997) in Virginia and in 1996 and 1997 in Mississippi. There were 48 steers at each location in each year (n = 240) in a 2 × 2 × 2 factorial arrangement with two replications at each location. Steers in Virginia were Angus and Angus × Hereford with initial weights of 245 kg (SD = 20), 234 kg (SD = 9), and 265 kg (SD = 5) in yr 1, 2, and 3, respectively. Steers in Mississippi were 3/4 Angus and 1/4 Brahman and weighed 230 kg (SD = 8) and 250 kg (SD = 2) in yr 2 and 3, respectively. Tasco (3.4 kg/ha) was dissolved in water and applied to pastures in April before grazing was begun and again in July at the same rate. The grazing period was from mid-April to late September or mid-October. Total gains were higher (P< 0.05) for steers grazing uninfected than for those grazing endophyte-infected tall fescue. Rectal temperatures were increased (P< 0.05) due to endophyte infection at both locations; Tasco application decreased temperature of steers grazing infected fescue in Virginia (interaction, P< 0.07) but increased temperatures of steers grazing infected fescue in Mississippi (interaction, P < 0.05). Presence of the endophyte resulted in rough hair coats and loss of hair color, but the effect was partially offset (P< 0.05) by Tasco application in Virginia in 1995. Both monocyte phagocytic activity (all years and locations) and major histocompatibility complex class II expression (1995 only) were decreased (P< 0.05) in steers due to endophyte infection, but this effect was reversed (P< 0.05) by application of Tasco to pastures. Application of the extract from A. nodosum seems to have use in alleviating adverse effects of endophyte on immune function and may improve hair coat condition in cattle grazing infected fescue, but effects on rectal temperature varied due to location.

Tasco-Forage an extract from the brown seaweed Ascophyllum nodosum, has increased antioxidant activity in both plants and animals. Turf and forage grasses exhibited increased amounts of α-tocopherol, ascorbic acid, β-carotene, and increased activities of superoxide dismutase, glutathione reductase, and ascorbate peroxidase in response to exogenous application of Tasco. Endophyte (Neotyphodium coenophialum[(Morgan-Jones and Gams) Glenn, Bacon, and Hanlin]-infected tall fescue (Festuca arundinaceaSchreb.) can increase oxidative stress. Both high environmental temperatures and increased body temperatures increase respiratory rates, which increase free radical production. Steers that grazed infected fescue had diminished immune function and vitamin E, Cu, and Se status, indicating less ability to deal with oxidative stress. Two applications of Tasco-Forage (3.4 kg/ha in water solution) to infected fescue during the growing season improved steers' immune function, and the effect lasted through cross-country transportation and a 160-d feedlot finishing period. Grazing infected fescue reduced serum cholesterol, but the effect was reversed by Tasco, indicating effects on lipid metabolism. Applying Tasco to low-endophyte fescue seemed to have an immune-dampening effect on steers, at least during the grazing season. At slaughter, marbling was greater in retail cuts of meat and meat had a longer shelf-life if steers had grazed the Tasco-treated fescue, regardless of the endophyte. Direct supplementation to steers with Tasco-EX (extract) during the final 14 d in the feedyard also extended shelf-life of strip loins. Supplementation of Tasco-EX or Tasco-14 (meal) to porcine reproductive and respiratory syndrome-stressed pigs during the nursery phase improved weight gain and feed intake within 35 d. Supplementing Tasco-EX in drinking water failed to reduce morbidity and mortality in transported heifers stressed by Pasturella haemolytica. The mode of action of Tasco is not clear, but antioxidants and specific vitamins may be involved. Supplementation with certain antioxidants can have beneficial effects, but inappropriate use can have detrimental effects. Although positive effects on stress tolerance and carcass composition are apparent, further research is needed to elucidate these relationships and to provide predictable responses.

A 3-yr study was conducted to evaluate immune response and Cu status of yearling beef steers as a consequence of grazing tall fescue (Festuca arundinaceaSchreb.) infected (E+) with the endophyte fungus Neotyphodium coenophialum([Morgan-Jones and Gams] Glenn, Bacon, and Hanlin). During a preliminary study in 1994, 24 weanling Angus and Angus × Hereford steers were blocked by breed and weight (initial BW 271 kg; SD 25) and were randomized to E+ and low endophyte (E−) fescue in pastures at Glade Spring, VA. Grazing began in April and was discontinued in July. In 1995 and 1996, 24 weanling Angus and Angus × Hereford steers (initial BW 249 kg, SD 20 and 240 kg, SD 15, respectively) were randomized to the E+ and E− pastures at Glade Spring during each year. Grazing began in April and continued until September in 1995 and October in 1996. In 1994, steers that grazed E+ fescue exhibited lower (P< .05) phagocytic activity, major histocompatibility complex (MHC) class II expression, ceruloplasmin, and serum Cu than steers that grazed E− tall fescue. During 1995, steers grazing E+ fescue had lower (P< .05) phagocytic activity and MHC class II expression than steers that grazed E− fescue. In 1996, one-half of the steers within each paddock received a Cu oxide bolus at the beginning of the grazing season. During 1996, phagocytic activity was lower (P< .01) and MHC class II expression tended (P< .07) to be lower in steers that grazed E+ tall fescue than in steers that grazed E− tall fescue. Copper supplementation increased (P< .05) MHC class II expression in July regardless of endophyte status over nonsupplemented steers. Steers that grazed E− tall fescue had higher (P< .05) plasma or serum Cu concentrations than steers that grazed E+ tall fescue in each year of the study. These data indicate that the endophyte compromised the immune function of grazing steers, and the data suggest a relationship with depressed Cu status.

Poor performance of livestock that graze tall fescue (Festuca arundinaceaSchreb.) has been associated with the endophyte fungus Neotyphodium coenophialum[Morgan-Jones and Gams] Glenn, Bacon, and Hanlin). Recent evidence suggests lowered Cu status and a depression of Cu-related immune function in steers that graze endophyte-infected (E+) tall fescue. Greenhouse and field studies investigated relationships between the endophyte and Cu concentrations in tall fescue. Seventeen infected ‘Kenhy’ clones were divided, and one plant of each pair was treated three times with Benomyl to remove the endophyte (E−). Plants were watered with nutrient solution in a greenhouse for 6 mo before sampling. Copper concentrations were greater (P< .001) in E− than in E+ clones (3.4 vs 2.8 μg/g; SE, .06). In the second greenhouse experiment, genetically similar E+ and E− ‘Kentucky’-31 (KY-31) and ‘Georgia Jessup’ were grown from seed and fertilized with nutrient solution to produce mature plants. Copper concentrations were higher (P< .05) in E− than in E+ tall fescue (8.6 vs 7.6 μg/g; SE, .3). In a field plot experiment in Texas, E+ and E− KY-31 were grown with 0, 50, and 100% replacement of potential evapotranspiration. By September, Cu concentrations were higher (P< .05) in E− than in E+ tall fescue (7.3 vs 6.6 μg/g; SE, .2). In pasture experiments, KY-31 E+ (> 70% infection level) and E− (< 5% infection level) tall fescue were grown in Virginia at two locations with three rates of N fertilizer. Copper concentrations were higher (P< .05) in E− than in E+ tall fescue (4.8 vs 4.5 μg/g; SE, .1) and increased (P< .01) linearly in response to N. Our data demonstrate that the presence of the endophyte is associated with lower Cu concentrations in tall fescue, which may contribute to lowered Cu status in animals and thus contribute to the etiology of fescue toxicity.

Background: Duplication of the popliteal and superficial femoral veins (PV, SFV) is a normal variant previously reported in up to 25% of limbs. Little clinical significance, however, has been attributed to this apparently common anomaly. The present study was designed to determine the incidence of duplications in individuals presenting for venous incompetence studies, and whether their presence could, in theory, act as a predisposing factor to deep venous thrombosis (DVT) formation.
Methods: Duplex ultrasound examinations were performed in which venous duplications were actively searched for and recorded. The diameters of both limbs of any duplicated system and the single vessel immediately distal to it were recorded. Using these measurements, the changes in total cross-sectional area (CSA) associated with these anomalies were calculated. In addition, with the knowledge that the volume flow rate must remain constant, the velocity changes associated with such systems were calculated.
Results: A total of 248 limbs from 177 patients was scanned. Duplications were found in 39 (15.7%) of these limbs. Of these, 30 limbs (77%) involved only the SFV, seven (18%) involved both the SFV and PV, and two (5%) involved only the PV. Short-segment SFV duplications were used to calculate the percentage change in total CSA and therefore blood flow velocities. Of the 13 (33%) suitable for such calculations, and calculating for each individual duplicated system, a mean increase in the vessel's total CSA of 42%, which corresponded to a theoretical decrease in blood flow velocity of 36%, was found.
Conclusion: The present study confirms the significantly high incidence of duplications of the PV and SFV and raises the possibility of the potential for DVT formation secondary to changes in flow velocities.