Effect of single- and multiple-dose 0.5% timolol maleate on intraocular pressure and pupil size in female horses

OBJECTIVE: To determine the effect of single and multiple-dose 0.5% timolol maleate on intraocular pressure (IOP) and pupil size between 8 AM and 8 PM. Animals Nine female horses with normotensive eyes. Procedure IOP, horizontal and vertical pupil size were measured on a single day, between 8 AM and 8 PM at hours 0, 0.5, 1, 2, 4, 6, 8, 10, and 12. A single dose of 0.5% timolol maleate was applied to both eyes immediately after the first measurement at 8 AM. IOP and pupil size were measured at 8 AM and 4 PM in a 5-day experiment of twice-daily application of 0.5% timolol maleate. RESULTS: A significant decrease in IOP from 24.9 +/- 4.2 mmHg prior to application of timolol maleate to 20.7 +/- 3.1 mmHg (4.2 mmHg = 17%) was observed 8 h after single-dose application. A significant decrease in horizontal pupil size (2.0 mm = 11%) was present 6 h after single-dose application. In the multiple-dose experiment, a significant decrease in IOP was present on days 4 and 5 as compared to IOP measured prior to application of timolol maleate. A significant decrease in horizontal and vertical pupil size was present throughout the 5-day study as compared to the values obtained prior to treatment. CONCLUSIONS: 0.5% timolol maleate significantly decreased IOP and pupil size in normo-tensive eyes of this group of female horses in both single and multiple twice daily applications.     

Control of cytokine gene expression using small RNA interference: blockade of interleukin-10 and interferon-gamma gene expression in pig cells

The ability of small RNA interference (RNAi) to reduce specific gene expression was tested using interleukin-10 (IL-10) and interferon-gamma (IFN-gamma) production by cultured swine blood mononuclear cells stimulated by Escherichia coli lipopolysaccharide or concanavalin A. Antisense (AS) phosphorothioate oligodeoxynucleotides (ODNs) corresponding to a sequence in the region of the AUG initiation codon of swine IL-10 or IFN-gamma mRNA inhibited production of IL-10 (>or=93.5%) and IFN-gamma (>or=99%) mRNAs. Interleukin-10 and IFN-gamma protein production was inhibited more than 95% by the AS ODNs. Scrambled and sense ODNs RNAi used as negative controls did not alter mRNA expression for either cytokine but slightly reduced IL-10 protein production. Cytokine-specific and control RNAi did not inhibit beta(2)-microglobulin mRNA expression in mitogen-stimulated blood mononuclear cells. Thus AS ODNs RNAi specifically inhibit expression of pig IL-10 and IFN-gamma mRNAs by cultured, mitogen-stimulated blood mononuclear cells and may be an attractive alternative method for studying cytokine function.     

Bovine lymphocytes: erythrocyte rosettes in normal, lymphomatous and corticosteroid-treated cattle.

Spontaneous erythrocyte rosettes, antibody-complement rosettes and nonrosetting cells were enumerated for peripheral blood lymphocytes of normal adult, lymphomatous adult and immature cattle as well as for peripheral blood lymphocytes of adult cows both before and after injection of corticosteroids. Calf thymic lymphocytes were also examined for rosette formation. Results indicate significant reduction in peripheral blood lymphocyte-erythrocyte rosettes and nonrosetting cells in tumour-bearing cows with a simultaneous elevation in percent antibody-complement rosettes. Calf thymus had a significantly greater percent erythrocyte rosettes than did peripheral blood lymphocytes from the same individuals. Corticosteroid injection reduced peripheral blood lymphocytes without altering proportion of cells as erythrocyte rosettes, antibody-complement rosettes or nonrosetting cells.     

Plasma growth hormone and insulin‐like growth factor‐I (IGF‐I) concentrations at the onset of lay in ad libitum and restricted broiler breeder fowl

1. Plasma concentrations of growth hormone (GH) and insulin‐like growth factor I (IGF‐I) were determined in individually caged broiler breeder females from 17 to 30 weeks of age. The birds were fed ad libitum or restricted during rearing in a randomised block design. Restricted birds were fed ad libitum after laying an egg and egg production was recorded to 54 weeks.

2. GH concentrations were higher in restricted compared with ad libitum‐fed birds at 17 to 21 weeks of age and were similar thereafter. Plasma IGF‐I concentrations were higher in restricted compared with ad libitum‐fed birds throughout the sampling period of the experiment.

3. The age at first egg was delayed by about two weeks in restricted birds. At 54 weeks of age they had laid 114 compared with 67 eggs in birds fed ad libitum throughout and had produced less than half the number of eggs with defective shells.

4. It was suggested that differences in egg production between ad libitum and restricted broiler breeder females could be related to changes in the pattern of GH and/or IGF‐I secretion.     

Adhesion molecules and lymphocyte subsets in milk and blood of periparturient Holstein cows.

Migration of leukocytes into the mammary gland is an essential element of resistance to infection which is likely influenced by expression of adhesion molecules. The contribution of subsets to mammary gland resistance remains unclear. Mononuclear cells from milk and blood of dairy cows were examined for variation in CD4+, CD8+, and WC1+ (Workshop Cluster 1; marker for gammadelta T cells) lymphocyte phenotypes and expression of LFA-1 and L-selectin at several time points during the periparturient period and at Week 16 of lactation. Proportions of CD4+ T cells were higher (p < or = 10.05) in blood than milk at all times between Week 0 and Week 16 relative to calving; the inverse was true of CD8+ cells. Expression of L-selectin was lower (p < or = 0.05) on CD4+ cells and higher on CD8+ cells from milk. The WC1+ subset was more frequent in blood than in milk except at calving when the opposite was true. After calving, proportions of L-selectin+ WC1+ cells decreased steadily to Week 16. Expression of LFA-1 was examined on mononuclear cell populations and found to be lower on milk cells and did not vary over time. We conclude that proportions of T cells subsets differ significantly between blood and milk, particularly around calving. Corresponding variations in L-selectin expression may indicate a role for this molecule in regulating the movement of CD8+ and WC1+ T cells into the bovine mammary gland.     

Interferon-alpha and haptoglobin in pigs selectively bred for high and low immune response and infected with Mycoplasma hyorhinis.

Pigs selected for high (H) or low (L) combined antibody and cell-mediated immune response were infected with Mycoplasma hyorhinis. Following the infection, arthritis was more severe in the H pigs, while pleuritis and peritonitis were more severe in the L pigs. Since Mycoplasma infections in pigs often cause just mild signs, indicators of the inflammatory response may aid diagnosis of such infections. In addition, data about the genetic influence on inflammatory response indicators are scanty in the pig. The objectives of the study were therefore: firstly, to determine interferon-alpha (IFNalpha) and haptoglobin in M. hyorhinis infected pigs and, secondly, to investigate if the inflammatory response as determined by these indicators was influenced by genetic selection. There was no consistent increase of IFN-alpha in serum following infection. The serum haptoglobin concentration started to increase 3 days post-infection and there was no difference between the two breeding lines. Hence, M. hyorhinis infection in pigs is reflected in increased serum haptoglobin concentration, but no effect of the magnitude of the inflammatory response on this indicator by selection for high or low immune response was observed.     

Effects of anaerobic digestion and additives to effluent or cattle feed on odor and odorant concentrations.

Odor intensity (5,437 observations), determined by human panelists (100 different panelists over the course of the experiment), and a number of chemical odorant concentrations were determined for manure-related samples (326) obtained from effluents from conventional stirred-tank reactor (CSTR) and fixed-film anaerobic digesters, effluents to which commercial additives or KMnO4 or H2O2 were added, and feces, urine, and mixed manure from cows fed a control or additive-containing diet. Mostly, samples were held in stoppered, Erlenmeyer flasks for 3 d at room temperature before evaluation by panelists and with chemical analyses, but shorter holding times also were tested. Anaerobic digestion reduced odor intensity linearly with increasing hydraulic retention time (HRT) up to 20 d; fixed-film digestion with 1.5- or 2.3-d HRT reduced odor intensity similarly to that observed with 10-d HRT in CSTR. Addition of commercial products and chemicals altered some odorant concentrations (e.g., ammonia) but did not reduce odor intensity; some products increased odor intensity. Addition of a commercial yeast-based product to a dairy cow diet had no detectable effect. The cow diet study showed that fresh urine and feces alone were less odorous than a mixed combination (manure). Fresh manure was less odorous than manure held for 3 d. Total phenol was the odorant most highly correlated with odor intensity. Individual and total volatile fatty acids also contributed. Ammonia did not seem to be a major contributor to odor in this data set.