The Content of β-endorphin-like Immunoreactivity in Porcine Corpus Luteum and the Potential Roles of Progesterone, Oxytocin and Prolactin in the Regulation of β-endorphin Release from Luteal Cells in vitro

The amount of β‐endorphin‐like immunoreactivity (β‐END‐LI) in porcine corpora lutea from several stages of the oestrous cycle and the effects of progesterone, oxytocin, and prolactin on β‐END‐LI secretion in vitro by luteal cells were studied. Porcine corpora lutea obtained on days 1–5, 6–10, 11–13, 14–18, and 19–21 of the cycle were used to prepare extracts for β‐END‐LI determination. Additionally, corpora lutea from days 11–13 and 14–18 were enzymatically dissociated and isolated luteal cells were used for further study of β‐endorphin secretion in vitro. Cells were cultured in serum‐free defined M 199 medium (10⁶ cells/ml) at 37°C under 5% CO₂ in air, for 12 h. The influences of the following factors on β‐END‐LI secretion by luteal cells were tested: progesterone (10^–9, 10^–7 and 10^–5M ), oxytocin (0.01, 0.1, 1 and 10 ng/ml), and prolactin (0.1, 1, 10 and 100 ng/ml). The β‐END‐LI contents in extracts and media were measured by radioimmunoassay. The tissue concentration of β‐END‐LI was lowest on days 1–5 of the cycle (0.35 ± 0.03 ng/g wet tissue). Subsequently, it constantly increased to the highest value on days 14–18 (16.58 ± 0.52 ng/g wet tissue) and on days 19–21 it declined (11.10 ± 0.52 ng/g wet tissue). Progesterone at a low dose (10^–9 M ) resulted in significant (p < 0.05) increases and decreases in β‐END‐LI secretion by luteal cells from days 11–13 and 14–18, respectively. Higher doses of progesterone (10^–7 and 10^–5 M ) had no effect on β‐END‐LI release, compared with the control group. All dose‐levels of oxytocin used decreased β‐END‐LI secretion by luteal cells on days 11–13 and 14–18 of the cycle. Prolactin at doses of 0.1 and 1 ng/ml on days 11–13, and all doses tested on days 14–18 resulted in decreases in β‐END‐LI release from luteal cells. These results document evident changes in β‐END‐LI content in the pig corpus luteum during its development and indicate the potential roles of progesterone, oxytocin, and prolactin in luteal cell secretion of β‐END‐LI.     

Characteristics of Rice Cultivars with Implications for Crawfish Double Cropping1

Twenty-five domestic rice (Oryza sativa L.) cultivars were evaluated in a simulated rice/crawfish double cropping system in southwest Louisiana during 1983 and 1984. Wide variation was observed among cultivars in parameters believed to be important for maximizing productivity in such a system. Mean maturity ranged from 99 (Labelle) to 118 days (Starbonnet), while height ranged from 76 (Bellemont) to 130 cm (Della, Nato). Significant differences in grain yield response were observed, with yields ranging from 4,101 (Bluebelle) to 6,665 kg/hectare (Newbonnet). Straw dry matter production varied greatly, from 3,831 (Bellemont) to 9,170 kg/hectare (Della), and was positively correlated with plant height (r = 0.64; P = 0.0001). Ratoon biomass production was negatively correlated with both grain yield (r = -0.39; P = 0.0001) and maturity group (r = -0.69; P = 0.0001). Plant senescence at grain maturity also varied greatly and appears to be a factor in post-harvest ratoon capability. Early or very early maturing cultivars with both proven grain production and good ratooning capability appear best suited. Cultivar selection should be based upon individual farm situations and currently employed agronomic practices.     

Efficacy of AHR-13268, an antiallergenic compound, in the management of pruritus caused by atopic disease in dogs.

Twenty-nine pruritic, atopic dogs were entered into a double-blind, placebo-controlled, crossover study to evaluate the efficacy of an investigational antiallergenic compound, AHR-13268. Fourteen dogs were evaluated by a veterinary dermatologist (at intervals) and the owner (daily). Fifteen dogs were evaluated only by the owner. The mean (+/- SE) owner scores for pruritus, erythema, and lesions with placebo treatment (higher score = worse signs) were 3.24 (+/- 0.12), 2.73 (+/- 0.12), and 2.61 (+/- 0.09), respectively. With drug treatment, the corresponding scores were 2.89 (+/- 0.12), 2.50 (+/- 0.12), and 2.25 (+/- 0.09). Scores for pruritus and lesions (but not erythema) were significantly better with drug treatment than with placebo treatment. Investigator scores showed similar trends, but the differences were not great enough to be statistically significant. Overall, 11/29 (38%) owners reported their dogs had moderate or better improvement from drug capsules, and 4/29 dogs (14%) improved on placebo capsules. A variety of adverse effects were reported following both drug (9/29 dogs) and placebo (8/29 dogs) capsule administration, but were mild and well tolerated. Results of this study indicate that AHR-13268 has potential for empiric treatment of allergic inhalant dermatitis in some dogs.     

A test for interaction between brown trout (Salmo trutta) and inanga (Galaxias maculatus) in an artificial stream

Abstract –  The interaction between brown trout ( Salmo trutta ; fork length (FL) range 255–390 mm) and inanga ( Galaxias maculatus ; FL range 55–115 mm) was tested during summer through autumn in an artificial stream consisting of a single run-riffle-pool sequence with a natural food supply. Each experimental trial lasted for 15 days, and consisted of two brown trout and 50 inanga collected fresh from a nearby stream, with each species given prior residence in four replicate tests, totalling eight trials in all. In addition, two control trials (each 10 days), with 50 inanga in each, were run. Brown trout almost exclusively occupied the pool, whereas inanga occupied all habitat types, although in different proportions, when tested with and without brown trout. The proportion of inanga in the pool was appreciably lower in the experimental trials with brown trout than in the control trials with no brown trout; prior residence had no significant effect on inanga habitat use. Mortality of inanga attributable to predation by brown trout ranged from 0 to 40% with a mean of 14.5 ± 4.7%. The results suggest that habitat use and survival of inanga populations in small streams can be adversely affected by brown trout.     

Isotypic antibody responses in cattle infected with Haemophilus somnus

Bovine antibody responses to Haemophilus somnus were compared on the basis of clinical and bacteriological findings. Serum IgG1 and IgM antibody titres were significantly increased in clinically normal cattle that were bacteriologically positive for H somnus from the nasal or vaginal mucosae compared with clinically normal, negative cows. IgG2 titres did not differ significantly between these two groups. However, IgG2 antibody was significantly higher in animals with H somnus disease (pneumonia or abortion) than in clinically normal cattle (whether bacteriologically positive or negative), while IgG1 and IgM titres did not differ between diseased and bacteriologically positive, clinically normal cattle. These antibody trends were duplicated in experimental H somnus abortion or pneumonia, with the greatest response occurring within the IgG2 subclass. Cattle vaccinated systemically with killed whole H somnus produced a predominant IgG2 response with minimal IgG1 and IgM responses. These results demonstrate that IgG2 antibody is consistently elevated in H somnus disease, and suggest that this response may be useful in discriminating diseased from asymptomatic cattle.     

Nephrolithiasis resulting in intermittent ureteral obstruction in a cow

Bilateral nephrolithiasis with intermittent ureterolithiasis was diagnosed in a 7-year old Holstein cow. Two episodes of ureterolithiasis resulted in severe azotemia which resolved after spontaneous movement of the stone. A third episode of obstruction one year after the initial episode resulted in rupture of one kidney, necessitating euthanasia. The histopathological examination of the kidney was diagnostic for chronic pyelonephritis. Corynebacterium sp. was cultured from a nephrolith. In this case it is believed that the chronic pyelonephritis predisposed to the calculi formation.     

Chemotactic response of bovine neutrophils to Pasteurella haemolytica culture fluid

Bovine neutrophil chemotactic activity was detected in the supernatant fluid of logarithmic phase cultures of P. haemolytica serotype 1. The chemoattractant was produced under culture conditions suitable for P. haemolytica leukotoxin production. An inverse correlation existed between the leukotoxin LC50 and the chemotactic activity in the culture fluid. Elimination of leukotoxin activity by heating, dilution or ultrafiltration, exposed the chemotactic activity in the culture fluid. The chemoattractant was partially resistant to heating (60 degrees C, 30 min), and had an apparent molecular weight greater than 100,000. Detection of chemotactic activity in both the concentrate and filtrate after XM300 filtration suggested that there might be more than one component with chemotactic activity or else that polymerization was occurring. Production of a potent neutrophil chemoattractant by P. haemolytica may explain the rapid infiltration of neutrophils that occurs during the early stages of bovine pneumonic pasteurellosis.