A multicenter comparison of the ocular efficacy and safety of diclofenac 0.1% solution with that of ketorolac 0.5% solution in patients with acute seasonal allergic conjunctivitis.

Only one of several available ophthalmic nonsteroidal anti-inflammatory drugs (NSAIDs) is currently FDA approved for use in acute seasonal allergic conjunctivitis (SAC). Sixty patients with SAC and moderate itching and bulbar conjunctival injection were enrolled in a multicenter, randomized, double-masked, parallel-group trial comparing diclofenac sodium (DS) with ketorolac tromethamine (KT). Patients instilled 1 drop four times daily while awake for 14 days. Ocular signs and symptoms were evaluated at one and two weeks. The primary efficacy variables were itching and bulbar conjunctival injection. For both treatments, the ocular allergy sign and symptom scores were comparable at baseline. Both treatments evaluated in this study were well tolerated. Significant clinical and statistical reductions from baseline were observed in the primary efficacy variables. Treatment group differences were observed for the pain/soreness score with an advantage observed for the DS group at 30 minutes and at day 7. Our conclusion is that diclofenac sodium and ketorolac tromethamine acted similarly to reduce the ocular signs and symptoms associated with acute seasonal allergic conjunctivitis. There was a statistically significant advantage for the DS group to be free of symptoms at the day 7 visit as compared to the KT group (20.7% vs. 3.2%).

Lack of effect of granulocyte-macrophage colony-stimulating factor on secretion of interferon-tau, other proteins, and prostaglandin E2 by the bovine and ovine conceptus.

Three experiments tested the effects of recombinant bovine granulocyte-macrophage colony-stimulating factor (rbGM-CSF) on the preimplantation bovine and ovine conceptus. There was no effect of rbGM-CSF on the secretion of total radiolabeled protein in conditioned medium, immunoreactive interferon-tau (IFN tau), antiviral activity, or prostaglandin E2 from Day 16-18 bovine conceptuses cultured for 24 hr with, [3H]leucine and +/- 10 ng/ml rbGM-CSF. Similarly, there was no effect of 1 ng/ml rbGM-CSF on the secretion of total radiolabeled protein. IFN tau, or antiviral activity from Day 17 ovine conceptuses. There was also no beneficial effect of 1 or 10 ng/ml rbGM-CSF on the presence of immunoreactive IFN tau in conditioned medium from in vitro-produced bovine blastocysts at Day 7-8 after fertilization. Results indicate that IFN tau secretion from bovine and ovine conceptuses are unresponsive to rbGM-CSF at the concentrations tested.

DNA synthesis and prostaglandin secretion by bovine endometrial cells as regulated by interleukin-1.

Interleukin-1 (IL-1) is a pleiotropic cytokine which has been implicated in the regulation of endometrial function through alterations in proliferation, protein synthesis, and prostaglandin secretion. The objectives of this study were to determine if recombinant bovine interleukin-1 beta (rbIL-1 beta) stimulated prostaglandin secretion and altered the proliferation of bovine endometrial epithelial and stromal cells. Uterine flushes were also evaluated by enzyme-linked immunosorbent assay (ELISA) to determine if IL-1 beta was present in the bovine uterus. Effects of rbIL-1 beta (1-1000 ng mL-1) on DNA synthesis by endometrial epithelial and stromal cells prepared from cows at Days 11, 14 and 17 after oestrus were determined by monitoring uptake of [3H]thymidine into DNA. Incorporation of [3H]thymidine by epithelial cells was not affected by IL-1, but rbIL-1 beta inhibited [3H]thymidine incorporation by stromal cells. Secretion of prostaglandin E2 (PGE2), PGF2 alpha, and 13,14-dihydro 15-keto PGF2 alpha (PGFM) by epithelial and stromal cells was increased by rbIL-1 beta. Uterine flushes collected on Days 11, 14 and 17 after oestrus were positive for IL-1 regardless of pregnancy status, whereas flushes from pregnant cows on Day 25 and Day 30 did not have any detectable IL-1. In conclusion, IL-1 can be considered as a local regulatory factor of the bovine endometrium because of its presence within the uterus and its ability to alter DNA synthesis and prostaglandin secretion of endometrial cells.

Effects of interferon-tau and interferon-alpha on proliferation of bovine endometrial cells.

The ruminant conceptus secretes a unique interferon, interferon-tau, that regulates endometrial prostaglandin secretion during early pregnancy. Because one of the pleiotropic effects of interferons is to inhibit cellular proliferation, a series of experiments was conducted to determine whether or not the bovine endometrium is sensitive to the antiproliferative effect of interferon-tau and the related interferon, interferon-alpha. Endometrial epithelial and stromal cells were prepared from the endometrium of cows from Days 11-17 after estrus and incubated with recombinant bovine interferon-tau (rbIFN tau; 1-1000 ng/ml), recombinant bovine interferon-alpha 1 (rbIFN alpha; 1-1000 ng/ml), recombinant human interferon-alpha 2b (rhIFN alpha; 100 ng/ml), or ovine interferon-tau (oIFN tau; 100 ng/ml). Proliferation was determined by monitoring uptake of [3H]thymidine into DNA. Generally, interferons did not inhibit proliferation of endometrial epithelial cells. Exceptions were for 1000 ng/ml rbIFN tau, which inhibited proliferation by 23%; 100 ng/ml rbIFN alpha, which inhibited proliferation by 28% in one of two experiments only; and 100 ng/ml oIFN tau, which inhibited proliferation by 17%. Proliferation of endometrial stromal cells was not inhibited by any concentration of any interferon in two separate experiments. Therefore, unlike other bovine cells tested previously (lymphocytes and oviductal cells), bovine endometrial cells were not consistently inhibited by IFN tau or IFN alpha. Such reduced responsiveness of endometrial cells to the antiproliferative effects of type I interferons could allow for growth of the endometrium during the period of pregnancy when the conceptus produces IFN tau.

Possible mechanisms for reduction of circulating concentrations of progesterone by interferon-alpha in cows: effects on hyperthermia, luteal cells, metabolism of progesterone and secretion of LH.

Experiments were performed to determine the mechanism by which recombinant bovine interferon-alpha I1 (rbIFN-alpha) causes an acute reduction in plasma concentrations of progesterone. In experiment 1, administration of a prostaglandin synthesis inhibitor blocked rbIFN-alpha-induced hyperthermia but did not prevent the decline in plasma concentrations of progesterone. The decline in progesterone concentrations caused by rbIFN-alpha was, therefore, not a direct consequence of the associated hyperthermia or of pathways mediated through prostaglandin synthesis. It is also unlikely that rbIFN-alpha acts to increase the clearance of progesterone since injection of rbIFN-alpha did not decrease plasma concentrations of progesterone in ovariectomized cows given an intravaginal implant of progesterone (experiment 2). In experiment 3, rbIFN-alpha did not affect basal and LH-induced release of progesterone from cultured luteal slices, indicating that rbIFN-alpha is unlikely to affect luteal function directly. Injection of rbIFN-alpha did, however, cause a decrease in plasma concentrations of LH in ovariectomized cows (experiment 4) that coincided temporally with the decrease in progesterone concentrations seen in cows having a functional corpus luteum. The present results strongly suggest that rbIFN-alpha acts to reduce secretion of progesterone by interfering with pituitary support for luteal synthesis of progesterone. The finding that rbIFN-alpha can inhibit LH secretion implies that interferon-alpha molecules should be considered among the cytokines that can regulate hypothalamic or pituitary function.

Regulation of prostaglandin secretion from epithelial and stromal cells of the bovine endometrium by interleukin-1 beta, interleukin-2, granulocyte-macrophage colony stimulating factor and tumor necrosis factor-alpha.

Bovine endometrium was obtained on day 16 of pregnancy (estrus = 0) and separated into epithelial and stromal cell populations. When confluent, the two cell populations were treated for 24 h with cytokines at 1, 10 and 100 ng/ml. Prostaglandin (PG) E2 was the major prostaglandin produced by both cell types. For control cultures, more PGE2 was secreted into medium by stromal cells than by epithelial cells, whereas secretion of PGF was similar for epithelial and stromal cells. Interleukin-1 beta had no effect on prostaglandin production by stromal cell cultures but increased epithelial production of PGE2 and, to a lesser extent, PGF. Conversely, granulocyte-macrophage colony stimulating factor had no effect on epithelial cells but reduced secretion of PGE2 and PGF from stromal cells. There were no effects of interleukin-2 or tumor necrosis factor-alpha on prostaglandin secretion. Results indicate that certain cytokines can regulate endometrial prostaglandin secretion in a cell type-restricted manner.

Relative importance of newly synthesized and stored hormone to basal secretion by growth hormone and prolactin cells.

It is generally accepted that under basal conditions there is preferential release of newly synthesized hormone by a number of endocrine cell type, including those that secrete GH or PRL. However, the cellular basis for this phenomenon along with the relative contribution of stored hormone to basal secretion has yet to be clearly established. In the present study, we employed reverse hemolytic plaque assays to monitor basal and stimulated release of GH and PRL from individual cells in which de novo protein synthesis had been blocked. Monodispersed pituitaries from adult male rats were cultured for 21 h in the absence or presence of maximally effective doses of puromycin (100 microM) or cycloheximide (36 microM) and were then subjected to separate plaque assays for GH or PRL. Treatment with puromycin reduced the percentage of GH or PRL secretors (plaque formers) by about half. Coincubation with stimulatory secretagogues did not increase the percentages of GH or PRL secretors in control cultures, but returned the proportion in puromycin-treated cells to normal, demonstrating that cells which failed to secrete basally could still release hormone from their stored pools when stimulated. Very similar results were obtained when these experiments were repeated with cycloheximide. Taken together, these results demonstrate that only a fraction of the cells that release GH or PRL are dependent upon newly synthesized hormone for basal secretion; the remainder appear capable of mobilizing stored hormone for this purpose even in the absence of stimulation.

Liver tissue from lactating rats produces a factor that stimulates prolactin release and gene expression.

Liver tissue from nursing rats produces a substance, termed liver lactogenic factor (LLF), that potently stimulates casein release from isolated mammary cells. Inasmuch as the production of LLF is dependent on PRL, we decided to determine whether it could influence the release of the hormone by dissociated pituitary cells in culture. This was accomplished by measuring PRL release with a reverse hemolytic plaque assay and PRL gene expression with a DNA probe complementary to PRL mRNA. Treatment of pituitary cells from day 10 lactating rats with liver slice incubates from the same type of animal caused a 35.3 +/- 4.3% increase in PRL release during a 3-h incubation. Likewise, the same dose of LLF activity markedly increased (3.5-fold) the steady state levels of PRL mRNA. The responses were reasonably specific for PRL, since neither GH plaque development nor gene expression was affected by identical treatment. Taken together these results demonstrate that LLF can act directly at the pituitary level to exert positive feedback effects on both PRL release and gene expression.

Cloprostenol induced luteal regression in the beef cow. II. Histological evaluation of corpora lutea and correlation with luteal progesterone.

Forty-two cycling, multiparous beef cows (percentage-Brahman) were injected twice at 11-d intervals with 500mug Cloprostenol (a prostaglandin F(2alpha) analog) to induce luteolysis. Cows were randomly assigned for ovariectomy at 12 hr intervals from 0 to 72 hr post-injection. Corpora lutea were excised and one-half of the corpus luteum was stored in phosphate-buffered formalin until mounting and staining with hematoxylin and eosin. The other half of the CL was snap-frozen for determination of progesterone content and concentration. Luteal cell density increased following Cloprostenol injection and was significantly correlated with a shift from predominantly healthy Type I cells to predominantly degenerating Types III and V cells. Cell mitosis tended to decrease by 12 hr and was lower by 24 hr post-injection. Cell pyknosis increased by 24 hr post-injection and was correlated with the decrease in percentage of healthy luteal cells. No pattern was detectable in cell karyorrhexis. Histological regression of the CL was inversely correlated with CL progesterone content. Therefore, we conclude that a reduction in cell mitosis is the earliest morphological sign of degeneration of the CL and that the CL follows a well-defined sequence of regression which is accompanied by a decrease in progesterone content.

Cloprostenol inouced luteal regression in the beef cow. I. Ovarian response and endocrine changes.

Forty-two cycling, multiparous beef cows (percentage-Brahman) were given two injections of 500 ug Cloprostenol (CLP) 11 days apart. Cows were randomly allocated to be ovariectomized at 0, 12, 24, 36, 48, 60 or 72 hr after the second CLP injection. Mean CL weight declined within 36 hr after CLP. Mean concentration of P4 in luteal tissue increased between o and 60 hr, while mean P4 content per CL declined by 12 hr after CLP. There was a precipitous decrease in mean serum P4 by 12 hr following CLP injection. Serum E2 was elevated until 24 hr and then declined through 72 hr after CLP. Follicular T concentration increased from 0 to 48 hr and then decreased by 60 hr. We conclude that CLP caused rapid diminution of luteal function which was accompanied by a reduction in P4 content but not in P4 concentration. Futhermore, the concentration of E2 in large follicles decreased by 72 hr post-CLP which is consistent with an alteration of the steroidogenic pathway in the periovulatory follicle.