Nutrient net absorption across the portal-drained viscera of forage-fed beef steers: Quantitative assessment and application to a nutritional prediction model.

This study aimed to establish the relationship between ME intake and energy and nutrient absorption across the portal-drained viscera (PDV) of forage-fed beef steers. Eight Angus (328 +/- 40 kg of BW) steers were surgically fitted with portal, mesenteric arterial, and mesenteric venous catheters, and were fed alfalfa cubes in a replicated 4 x 4 Latin square design with 4 levels of energy intake between 1 and 2 times maintenance energy requirements. On d 28 of each experimental period, p-aminohippuric acid was infused to measure blood and plasma flow across the PDV, and blood samples (1 every hour, for 6 h) were collected simultaneously from arterial and venous catheters for net absorption measurements. Oxygen utilization, and therefore energy utilization, increased (P < 0.05) linearly in relation to ME intake. Glucose net uptake was unaffected, but lactate net release increased linearly in response to ME intake (P < 0.05). Net absorption of all AA except tryptophan, glutamate, and glutamine increased linearly with ME intake (P < 0.05). The constant net absorption of glutamate and glutamine indicated increased net utilization of these AA when dietary supply was increased. These data provide quantitative measures of the PDV effects on energy and AA availability for productive tissues, and suggest that the greater net utilization of some AA when ME intake is increased could relate to their catabolism for energy production. Prediction estimates of small intestinal AA absorption, based on the Cornell Net Carbohydrate and Protein System (CNCPS), exceeded observed net AA PDV absorption. Mean bias represented the greatest proportion (87 to 96%) of the deviation between individual AA absorption and observed net AA PDV absorption, suggesting that the CNCPS model may be used to predict AA net absorption when factors describing AA utilization by the PDV are applied to model predictions.

The Poisson Index: a new probabilistic model for protein ligand binding site similarity.

MOTIVATION: The large-scale comparison of protein-ligand binding sites is problematic, in that measures of structural similarity are difficult to quantify and are not easily understood in terms of statistical similarity that can ultimately be related to structure and function. We present a binding site matching score the Poisson Index (PI) based upon a well-defined statistical model. PI requires only the number of matching atoms between two sites and the size of the two sites-the same information used by the Tanimoto Index (TI), a comparable and widely used measure for molecular similarity. We apply PI and TI to a previously automatically extracted set of binding sites to determine the robustness and usefulness of both scores. RESULTS: We found that PI outperforms TI; moreover, site similarity is poorly defined for TI at values around the 99.5% confidence level for which PI is well defined. A difference map at this confidence level shows that PI gives much more meaningful information than TI. We show individual examples where TI fails to distinguish either a false or a true site paring in contrast to PI, which performs much better. TI cannot handle large or small sites very well, or the comparison of large and small sites, in contrast to PI that is shown to be much more robust. Despite the difficulty of determining a biological 'ground truth' for binding site similarity we conclude that PI is a suitable measure of binding site similarity and could form the basis for a binding site classification scheme comparable to existing protein domain classification schema.

The PPARgamma ligand, rosiglitazone, reduces airways hyperresponsiveness in a murine model of allergen-induced inflammation.

There is considerable interest in the role of peroxisome proliferator activated receptors (PPARs) as ligand-activated transcription factors in the airways. This study examines the effects of a potent synthetic PPARgamma ligand, rosiglitazone (RG), in a murine model of allergen-induced inflammation, to explore its potential regulation of airways inflammation, structure and function. C57BL/6 mice were sensitised with ovalbumin (OVA, 50 microg i.p., days 0, 12) and challenged with aerosolized OVA (1% w v(-1), 30 min day(-1)) for 7 days (days 20-26). Mice were treated with RG (5 mg kg(-1) i.p.) or vehicle during the challenge period. The OVA challenge induced increases in leukocyte number and MMP-2 activity in bronchoalveolar lavage fluid and in goblet cell number in lung tissue obtained on Day 27. RG failed to inhibit inflammatory cell infiltration, MMP-2 activity or goblet cell hyperplasia. Respiratory resistance in response to methacholine (MCh i.v.) was greater in OVA-challenged mice than saline-challenged mice and this airways hyperresponsiveness (AHR) was reduced by RG. However, RG did not affect MCh-induced contraction in isolated guinea-pig tracheal rings, nor did it influence the airway obstruction induced by MCh in saline-challenged mice, so a direct effect on airway obstruction is unlikely. These data suggest that RG modulates AHR in this model, by a mechanism that is also potentially independent of an anti-inflammatory action.

Corn grain endosperm type and brown midrib 3 corn silage: site of digestion and ruminal digestion kinetics in lactating cows.

Interactions of endosperm type of corn grain and the brown midrib 3 (bm3) mutation in corn silage on ruminal kinetics and site of nutrient digestion of lactating dairy cows were evaluated. Eight ruminally and duodenally cannulated cows (72 +/- 8 d in milk; mean +/- SD) were used in a duplicated 4 x 4 Latin square design experiment with a 2 x 2 factorial arrangement of treatments. Treatments were corn grain endosperm type (floury or vitreous) and corn silage type (bm3 or isogenic normal). Diets contained 26% neutral detergent fiber (NDF) and 30% starch. Interactions of treatments were not observed for any measure of digestibility, but digestion kinetics of starch and fiber did interact to affect digestible organic matter intake by affecting dry matter intake. Rate of ruminal starch digestion was faster and rate of ruminal starch passage tended to be slower in diets containing corn grain with floury vs. vitreous endosperm, resulting in a mean increase of 22 units for ruminal starch digestibility. Although compensatory postruminal starch digestion decreased differences among treatments for total tract starch digestibility, starch entering the duodenum was more digestible for grain with floury endosperm compared with vitreous grain, resulting in greater total tract starch digestibility for floury compared with vitreous corn grain. Fermentation rate of potentially digestible NDF was not affected by either bm3 corn silage or greater ruminal starch digestion of floury grain. Brown midrib corn silage increased total tract NDF digestibility vs. control silage by numerically increasing ruminal and postruminal digestibility of NDF. Endosperm type of corn grain greatly influences site of starch digestion and should be considered when formulating diets.

Corn grain endosperm type and brown midrib 3 corn silage: feeding behavior and milk yield of lactating cows.

Interactions of endosperm type of corn grain and the brown midrib 3 mutation (bm3) in corn silage on feeding behavior, productivity, energy balance, and plasma metabolites of lactating dairy cows were evaluated. Eight ruminally and duodenally cannulated cows (72 +/- 8 d in milk; mean +/- SD) were used in a duplicated 4 x 4 Latin square design experiment with a 2 x 2 factorial arrangement of treatments. Treatments were corn grain endosperm type (floury or vitreous), and corn silage type (bm3 or isogenic control). Diets contained 26% neutral detergent fiber (NDF) and 30% starch. Floury endosperm grain decreased dry matter intake (DMI) 1.9 kg/ d compared with vitreous grain when combined with control corn silage but did not affect DMI when combined with bm3 corn silage. This interaction of treatments occurred because of changes in meal size; floury endosperm grain decreased meal size in control silage diets but increased meal size in bm3 corn silage diets. Ruminal pool sizes reflected DMI differences among diets, suggesting that ruminal fill was not the primary limitation on intake. Brown midrib 3 corn silage reduced rumination time per day and number of rumination bouts per day. Floury endosperm grain decreased 3.5% fat-corrected milk by 1.2 kg/d when combined with control silage but increased 3.5% fat-corrected milk by 2.1 kg/d when combined with bm3 corn silage. Starch and fiber digestibility interact to affect feeding behavior and milk production and production response to bm3 corn silage depends on the grain source that is fed.

Corn grain endosperm type and brown midrib 3 corn silage: ruminal fermentation and N partitioning in lactating cows.

Interactions of endosperm type of corn grain and the brown midrib 3 mutation (bm3) in corn silage on ruminal fermentation and microbial efficiency of lactating dairy cows were evaluated. Eight ruminally and duodenally cannulated cows (72 +/- 8 d in milk; mean +/- SD) were used in a duplicated 4 x 4 Latin square design experiment with a 2 x 2 factorial arrangement of treatments. Treatments were corn grain endosperm type (floury or vitreous) and corn silage type (bm3 or isogenic normal). Diets contained 26% neutral detergent fiber and 30% starch. Increasing ruminal starch digestibility by replacing vitreous corn grain with floury grain reduced mean and minimum ruminal pH. Brown midrib 3 corn silage reduced mean and minimum ruminal pH and increased total volatile fatty acid concentration. Ruminal pH was positively associated with rate of valerate absorption. Although floury endosperm reduced acetate:propionate ratio in both control and bm3 corn silage diets, it had a greater effect on reducing acetate:propionate ratio for control silage compared with bm3 corn silage. Nonammonia N flow to the duodenum did not differ among treatments and no effects of treatment were detected for microbial N and nonammonia, nonmicrobial N flow. Although treatment effects on ruminal fermentation and ruminal pH were observed, few interactions of treatment were detected and treatments did not affect flow of N fractions to the intestines.

The effects of buffered propionic acid-based additives alone or combined with microbial inoculation on the fermentation of high moisture corn and whole-crop barley.

Buffered propionic acid-based additives (BP) alone or in combination with a microbial inoculant containing lactic acid bacteria (MI) were mixed with ground, high moisture corn or whole-crop barley and ensiled in triplicate laboratory silos to investigate their effects on silage fermentation and aerobic stability. The inoculant and chemicals were applied separately for treatments that included both additives. The addition of MI alone had no effect on DM recovery, fermentation end products, or aerobic stability of high moisture corn. However, treatments with 0.1 and 0.2% BP (alone and the combination) had more than 10- and 100-fold fewer yeasts, respectively, and they also had greater concentrations of propionic acid than did untreated corn. Corn treated with only 0.1 (161 h) and 0.2% (218 h) BP tended to be more stable when exposed to air than untreated corn (122 h). Treatment with MI + 0.2% BP markedly improved the aerobic stability (>400 h) of high moisture corn. With whole-crop barley, the addition of MI alone, BP alone, and combinations of MI and BP prevented the production of butyric acid that was found in untreated silage (0.48%). All barley silages that had MI in their treatments underwent a more efficient fermentation than treatments without MI, as evident by a greater ratio of lactic:acetic acid and more DM recovery than in untreated silage. Increasing levels (0.1 to 0.2%) of BP added together with MI improved the aerobic stability of barley (190 and 429 h) over the addition of MI alone (50 h). These data show that buffered propionic acid-based products are compatible with microbial inoculants and, in some circumstances when used together, they can improve the fermentation and aerobic stability of silages.

The effect of treating alfalfa with Lactobacillus buchneri 40788 on silage fermentation, aerobic stability, and nutritive value for lactating dairy cows.

Lactobacillus buchneri 40788 and enzymes (beta-glucanase, alpha-amylase, xylanase, and galactomannase) were applied to chopped alfalfa (39% DM) to study their effects on the fermentation and nutritive value of the silage. Alfalfa was treated with nothing, or L. buchneri 40788, for a final application rate of 1 x 10(5), 5 x 10(5), or 1 x 10(6) cfu/g of fresh forage and ensiled in laboratory silos for 2, 4, 8, and 56 d. Treatment with L. buchneri 40788 had few effects on the end products of fermentation through 8 d of ensiling. However, after 56 d of ensiling, treated silages had a higher pH (4.55 vs. 4.38) and higher concentrations of acetic acid (6.40 vs. 4.24%), propionic acid (0.18 vs. 0.06%), and ammonia-N (0.35 vs. 0.29%) when compared to untreated silage. Lactic acid was also numerically lower in treated (3.51%) than untreated (4.12%). Silages treated with the moderate and highest dose of L. buchneri 40788 also resulted in greater recoveries of DM than did untreated silage. Alfalfa (43% DM) was also untreated or treated with a commercial application of L. buchneri 40788 (4 x 10(5) cfu/g, a commercial dose) in farm-scale bag silo. Holstein cows were fed a diet comprised of 32% untreated or treated alfalfa silage, 11% corn silage, 5% chopped alfalfa hay, and 52% of concentrate (DMB) for a 6-wk treatment period. Dry matter intake and milk composition were unaffected by treatment, but cows fed silage treated with L. buchneri 40788 produced 0.8 kg more milk than did cows fed untreated silage. Treated silage had a higher concentration of acetic acid (5.67 vs. 3.35%) but lower lactic acid (3.50 vs. 4.39%) than untreated silage. When exposed to air, the total mixed ration containing treated alfalfa silage remained stable for 100 h, whereas the ration containing untreated silage spoiled after 68 h. Treating alfalfa silage with L. buchneri 40788 increased the concentration of acetic acid, and when the silage was combined into a total mixed ration and fed to lactating cows, it improved the aerobic stability of the ration and increased milk production.

The effect of treating whole-plant barley with Lactobacillus buchneri 40788 on silage fermentation, aerobic stability, and nutritive value for dairy cows.

Chopped barley forage was ensiled untreated or treated with several doses (1 x 10(5) to 1 x 10(6) cfu/g of fresh forage) of Lactobacillus buchneri 40788 in laboratory silos and untreated or treated (4 x 10(5) cfu/g) in a farm silo. Silage from the farm silos was fed to lactating cows. In the laboratory silo, the effects of inoculation on fermentation and aerobic stability were also compared to silage treated with a commercial inoculant and a buffered propionic acid additive. Inoculation with L. buchneri 40788 decreased the final concentrations of lactic acid but increased concentrations of acetic acid and ethanol in silage from laboratory and farm silos. Silages stored in laboratory silos did not heat after exposure to air for 7 d and were then mixed with alfalfa silage and a concentrate to form total mixed rations (TMR) that were further exposed to air. The TMR containing silages treated with L. buchneri 40788 or a buffered propionic-acid-based additive took longer to heat and spoil than the TMR containing untreated silage or silagetreated with the commercial inoculant. Silage stored in a farm silo and treated with L. buchneri 40788 had fewer yeasts and molds than did untreated silage. Aerobic stability was greater in treated silage alone and in a TMR containing treated silage. Dry matter intake (18.6 kg/d), milk production (25.7 kg/d), and milk composition did not differ between cows fed a TMR containinguntreated or treated silage. These findings show that L. buchneri can improve the aerobic stability of barley silage in laboratory and farm silos and that feeding treated silage had no negative effect on intake or performance.

The effect of Lactobacillus buchneri 40788 on the fermentation and aerobic stability of high moisture corn in laboratory silos.

The production of antifungal compounds during fermentation could be a useful mechanism to improve the aerobic stability of fermented feeds when they are exposed to air. High moisture corn (26% moisture) was ground and inoculated with various amounts of Lactobacillus buchneri 40788, a heterolactic acid bacteria, and ensiled in laboratory silos. Inoculation with L. buchneri 40788 from 1 x 10(5) to 1 x 10(6) cfu/g of corn had minor effects on the end products of fermentation during the early stage of ensiling (< or = 14 d). However, after 49, 92, and 166 d of ensiling, increasing the application rate of L. buchneri 40788 applied to corn increased the concentration of acetic acid when compared to untreated corn. Addition of L. buchneri 40788 had few other effects on the end products of fermentation. Dry matter recovery and aerobic stability were measured after 92 and 166 d of ensiling. At these times, dry matter recovery was not different among treatments, and numbers of yeasts and molds tended to decrease as the application rate of L. buchneri 40788 increased. Aerobic stability (number of h prior to a 2 degrees C rise in temperature after exposure to air) was markedly improved by the addition > or = 5 x 10(5) cfu/g of L. buchneri 40788. Combining L. buchneri 40788 with L. plantarum did not impart better aerobic stability than when L. buchneri 40788 was applied alone to corn. Addition of L. buchneri 40788 did not affect the rate of fermentation in high moisture corn, but after prolonged storage higher application rates increased production of acetic acid and markedly improved aerobic stability.

Olanzapine as alternative therapy for patients with haloperidol-induced extrapyramidal symptoms: results of a multicenter, collaborative trial in Latin America.

Conventional antipsychotic agents can induce extrapyramidal symptoms (EPS) that may be alleviated by switching patients to novel agents such as olanzapine. Patients with schizophrenia and related disorders (ICD-10) who were taking haloperidol (N = 94; mean dose = 12.7 mg/day) and had EPS (Simpson-Angus Scale [SAS] > 3) were directly switched to 6 weeks of open-label olanzapine treatment (mean dose = 11.4 mg/day). There were significant mean improvements (p <0.001 for all measurements) from baseline to endpoint on the SAS (-9.69+/-5.33; percentage change, 87.2%), the Barnes Akathisia Scale (-1.00+/-1.19; percentage change, 82.5%), and the Abnormal Involuntary Movement Scale (-1.48+/-2.89; percentage change, 81.1%), and anticholinergic use decreased from 47.9% to 12.8% (mean baseline to endpoint change: -1.52+/-1.91-mg equivalents of benztropine; p < 0.001). Significant mean baseline to endpoint improvements (p < 0.001 for all measurements) were observed on the Positive and Negative Syndrome Scale (PANSS; -25.28+/-18.67; percentage change, 30.3%), the PANSS-extracted Brief Psychiatric Rating Scale (0-6 scale, -13.41+/-10.16; percentage change, 54.4%), and the Clinical Global Impressions Severity scale (-1.16+/-1.19; percentage change, 26.4%). Spontaneously reported treatment- emergent adverse events with a greater than 5% incidence were somnolence (16.0%), increased appetite (14.9%), weight gain (11.7%), headache (8.5%), anxiety (7.4%), dizziness (6.4%), and insomnia (5.3%). Criteria for a successful switch were met by 90.5% of patients. Psychotic symptom exacerbation was experienced by 30.9% of patients at any time during the study and by 11.7% of patients at endpoint. Results suggest that a direct switch to olanzapine is a therapeutic option when patients with haloperidol-induced EPS are unable to tolerate a more gradual switch.

A meta-analysis of the use of typical antipsychotic agents in bipolar disorder.

BACKGROUND: The potential benefits of typical antipsychotic agents in bipolar disorder are offset by serious treatment-associated side effects. Despite these concerns and the availability of mood stabilizing agents, the treatment of bipolar disorder with typical antipsychotic agents appears to be widespread. METHODS: A Medline search identified 16 publications that outlined medication use among 2378 bipolar disorder patients. Meta-analysis was used to estimate a weighted average of the relative proportions of the treatment use, where the weights were the reciprocals of the estimated variances for each study. RESULTS: Overall, 84.7% of bipolar patients received typical antipsychotic agents, with a loading toward a greater in-patient (90.7%) relative to out-patient (65.3%) use. Monotherapy accounted for 53.8% of typical antipsychotic use, and typical antipsychotic/mood stabilizer combination therapy accounted for 47.4%. In four studies where length of treatment data were available, the median of minimum typical antipsychotic use was 2.5 months, with 96.0% of the patients receiving typical antipsychotic agents. LIMITATIONS: The meta-analytic technique employed in this analysis is limited by the possible inclusion of studies with unreliable study designs or biased treatment practices, publication bias in which some studies may not have been reported, and possible lack of identification of all relevant studies. CONCLUSIONS: Typical antipsychotic agents are commonly used in the treatment of bipolar disorder, possibly due to dissatisfaction with mood stabilizer monotherapy especially in psychotic mania, the high prevalence of psychotic symptoms in acute mania, inappropriate continuation of typical antipsychotic agents after initial stabilization, and/or unavailability or unfamiliarity with new treatments. These findings also suggest that typical antipsychotics may have not only antipsychotic effects in mania but perhaps also antimanic properties.

Factors influencing acute weight change in patients with schizophrenia treated with olanzapine, haloperidol, or risperidone.

OBJECTIVE: Clinical factors predicting weight change in patients with schizophrenia and related disorders during acute treatment with the antipsychotic drugs olanzapine, risperidone, and haloperidol were sought through retrospective analyses. METHOD: Six-week body-weight data from 2 trials, study 1 comparing olanzapine and haloperidol (N = 1,369) and study 2 olanzapine and risperidone (N = 268), were analyzed. Effects of 8 clinically relevant covariates--therapy, clinical outcome (Brief Psychiatric Rating Scale), baseline body mass index (BBMI), increased appetite, age, gender, race, and dose--on weight were compared. RESULTS: In study 1, olanzapine (vs. haloperidol) therapy, better clinical outcome, lower BBMI, and nonwhite race significantly affected weight gain. Effects of increased appetite and male gender on weight gain were significant for olanzapine but not for haloperidol. In study 2, better clinical outcome, lower BBMI, and younger age significantly affected weight gain. Increased appetite was more frequent during olanzapine treatment than during haloperidol, but not significantly different from risperidone. Significant differences in effect on weight change were found between olanzapine and haloperidol but not between olanzapine and risperidone. No evidence was found that lower antipsychotic drug doses were associated with lower weight gain. CONCLUSION: This report identifies predictive factors of acute weight change in patients with schizophrenia. Similar factors across antipsychotic drugs in predicting greater weight gain included better clinical outcome, low BBMI, and nonwhite race. Factors differing between conventional (haloperidol) and atypical (olanzapine) agents included increased appetite and gender. Choice of atypical antipsychotic drug (olanzapine vs. risperidone) was of minor importance with regard to influence on acute weight gain.

The K-function for nearly regular point processes.

We propose modeling a nearly regular point pattern by a generalized Neyman-Scott process in which the offspring are Gaussian perturbations from a regular mean configuration. The mean configuration of interest is an equilateral grid, but our results can be used for any stationary regular grid. The case of uniformly distributed points is first studied as a benchmark. By considering the square of the interpoint distances, we can evaluate the first two moments of the K-function. These results can be used for parameter estimation, and simulations are used to both verify the theory and to assess the accuracy of the estimators. The methodology is applied to an investigation of regularity in plumes observed from swimming microorganisms.

The efficacy of a rapid-acting intramuscular formulation of olanzapine for positive symptoms.

Rapid tranquilization of acutely psychotic patients with schizophrenia is usually carried out using typical antipsychotic agents. The objective of such treatment is to control agitation, not to treat psychosis, which usually responds only after a few weeks of treatment. An intramuscular formulation of the atypical antipsychotic olanzapine was developed for treatment of agitation in acutely psychotic patients. Studies conducted to assess control of agitation in schizophrenia also investigated the positive symptom efficacy of olanzapine when used to provide rapid tranquilization. This article summarizes the results of 3 clinical trials with intramuscular olanzapine with regard to positive symptom efficacy as measured by the Brief Psychiatric Rating Scale (BPRS; 0-6 scale) positive subscale. In 2 open-label trials, patients treated with intramuscular olanzapine experienced a mean decrease from baseline in BPRS positive subscale score. In 1 double-blind clinical trial of intramuscular olanzapine versus intramuscular haloperidol and intramuscular placebo, the mean decrease from baseline in BPRS positive subscale score for patients treated with intramuscular olanzapine was statistically significant (p < .05). In all 3 studies, positive symptom improvement continued following transition to oral olanzapine. These results suggest that intramuscular olanzapine has positive symptom efficacy early in the course of treatment and may provide a smooth transition to maintenance therapy with oral olanzapine.

The effects of olanzapine, risperidone, and haloperidol on plasma prolactin levels in patients with schizophrenia.

BACKGROUND: There is relatively little comparative information on elevations in plasma prolactin level (PRL) with conventional versus novel antipsychotic agents. OBJECTIVE: This paper examines the comparative effects on PRL of olanzapine, risperidone, and haloperidol based on data from 3 multicenter, double-blind, randomized clinical trials. Magnitude of response, dose dependency, time course, effects of sex and age, and response to switching from haloperidol to olanzapine are assessed. METHODS: The effects of olanzapine, risperidone, and haloperidol on PRL were assessed in patients with schizophrenia or related psychoses participating in 3 double-blind clinical trials: (1) a 6-week acute trial comparing olanzapine 5 to 20 mg/d (n = 1,336) and haloperidol 5 to 20 mg/d (n = 660), with a 1-year, open-label olanzapine extension for responders; (2) a 54-week study comparing olanzapine 5 to 20 mg/d (n = 21), risperidone 4 to 10 mg/d (n = 21), and haloperidol 5 to 20 mg/d (n = 23) in early illness; and (3) a 28-week study comparing olanzapine 10 to 20 mg/d (n = 172) and risperidone 4 to 12 mg/d (n = 167). RESULTS: PRL elevations were significantly greater with risperidone than with either olanzapine or haloperidol in study 2. and significantly greater than with olanzapine in study 3 (all, P < 0.001). PRL elevations were significantly greater with haloperidol than with olanzapine in study 1 (P < 0.001 ). A dose-response relationship was not consistently confirmed with any of the drug treatments. Risperidone-associated PRL elevations peaked relatively early in treatment. In haloperidol- and risperidone-treated patients, the mean change in PRL was greater in women than in men. PRL decreased significantly when treatment was switched from haloperidol to olanzapine. CONCLUSIONS: This side-by-side analysis of 3 independent studies suggests that with the 3 antipsychotic drugs studied, PRL is elevated moderately by olanzapine (mean change, 1-4 ng/mL), intermediately by haloperidol (mean change, approximately 17 ng/mL), and strongly by risperidone (mean change, 45-80 ng/mL). No consistent dose-response relationship was observed, and the time course and sex-dependency of the response differed between the 3 agents. Patients with haloperidol-induced hyperprolactinemia may benefit from a switch to olanzapine. Long-term studies examining the health consequences of chronic hyperprolactinemia during antipsychotic treatment are needed.

Development of a syngeneic mouse model for events related to ovarian cancer.

Mouse ovarian surface epithelial cells (MOSEC) were obtained from virgin, mature mice by mild trypsinization and were repeatedly passaged in vitro. Early passage cells (<20 passages) exhibited a cobblestone morphology and contact inhibition of growth. After approximately 20 passages in vitro, cobblestone morphology and contact inhibition of growth was lost. Tumor forming potential was determined by s.c. and i.p. injection of early and late passage cells into athymic and syngeneic C57BL6 mice. Subcutaneous tumors formed in approximately 4 months and were present only at the injection site. Intraperitoneal injection of late passage MOSEC into athymic and syngeneic mice resulted in growth of tumor implants throughout the abdominal cavity, and production of hemorrhagic ascitic fluid. Early passage MOSEC did not form tumors in vivo. Histopathologic analysis of tumors revealed a highly malignant neoplasm containing both carcinomatous and sarcomatous components. Late passage MOSEC expressed cytokeratin and did not produce ovarian steroids in response to gonadotropin stimulation in vitro. Ten clonal lines were established from late passage MOSEC. Each clone formed multiple peritoneal tumors and ascitic fluid after i.p. injection into C57BL6 mice. Three cell lines examined cytogenetically were polyploid with near-tetraploid modal chromosome numbers. Common clonal chromosome gains and losses included +5, +15, +19 and -X, -3, -4. One cell line had a clonal translocation between chromosomes 15 and 18 and another had a small marker chromosome; common structural abnormalities were not observed. These data describe the development of a mouse model for the study of events related to ovarian cancer in humans. The ability of the MOSEC to form extensive tumors within the peritoneal cavity, similar to those seen in women with Stage III and IV cancer, and the ability of the MOSEC to produce tumors in mice with intact immune systems, makes this model unique for investigations of molecular and immune interactions in ovarian cancer development.

Platelet-derived growth factor activates porcine thecal cell phosphatidylinositol-3-kinase-Akt/PKB and ras-extracellular signal-regulated kinase-1/2 kinase signaling pathways via the platelet-derived growth factor-beta receptor.

Platelet-derived growth factor (PDGF) is a potent mitogenic factor for ovarian thecal cells cultured in vitro. PDGF binds to and induces homo- or heterodimerization of PDGF receptor-a or -beta (PDGF-Ralpha or PDGF-Rbeta). Despite this, little information is available about which PDGF receptors are expressed in the ovary, what signaling cascades are activated by PDGF, and the effects of PDGF on thecal cell steroidogenesis. The present study demonstrates the expression of immunoreactive PDGF-Rbeta, but not PDGF-Ralpha, in the thecal and stromal compartments of intact porcine ovaries as well as in cultured porcine thecal cells. Treatment of porcine thecal cells in vitro with PDGF resulted in rapid and sustained tyrosine phosphorylation of PDGF-Rbeta, activation of Src tyrosine kinase and phosphatidylinositol-3-kinase (PI3-kinase), and serine 473 phosphorylation of Akt/protein kinase B. In addition, PDGF stimulated an increase in GTP-Ras (activated Ras) and extracellular signal-regulated kinase (ERK) phosphorylation. Both forms of PDGF, AB and BB, stimulated thecal cell growth approximately 3- to 4-fold over controls and inhibited LH-stimulated progesterone and androstenedione secretion. Blockade of PI3-kinase activation with wortmannin had no effect on PDGF-stimulated thecal cell growth or PDGF inhibition ofLH-stimulated steroid secretion, indicating that PI3-kinase activation is not necessary for PDGF-stimulated thecal cell growth or inhibition of LH-stimulated steroidogenesis. Conversely, blockade of the MEK-ERK pathway with PD98059 completely blocked PDGF-stimulated cell growth, indicating that activation of the MEK-ERK pathway is required for PDGF-stimulated thecal cell growth. Additionally, the MEK inhibitor PD98059 restored LH-stimulated steroid secretion, demonstrating that activation of the MEK-ERK pathway can lead to inhibition of LH-stimulated steroid secretion. The present study demonstrates that PDGF acts on ovarian thecal cells via activation of the PDGF beta-receptor and stimulates thecal cell growth via activation of a Rasmitogen-activated protein kinase-dependent, PI3-kinase-independent pathway. The strong expression of PDGF-Rbeta and the potent effects of PDGF on thecal cell growth and steroidogenesis suggest an important role for PDGF in thecal cell recruitment and growth during follicular development in vivo.

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) blocks ovulation by a direct action on the ovary without alteration of ovarian steroidogenesis: lack of a direct effect on ovarian granulosa and thecal-interstitial cell steroidogenesis in vitro.

The main purpose of this study was to investigate the direct effect of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on ovarian function including ovulation and steroidogenesis. In vivo effects of TCDD were investigated on ovulation and alteration of circulating and ovarian steroid hormones in immature hypophysectomized rats (IHR) primed with equine chorionic gonadotropin (eCG) and human chorionic gonadotropin (hCG). In addition, in vitro effects of TCDD on the steroidogenesis of granulosa cells (GC), theca-interstitial cells (TIC), and whole ovarian dispersates derived from the ovary of IHR were investigated. In the ovulation model, rats were hypophysectomized on Day 23 of age. On Day 26, the IHR were given 20 microg TCDD/kg by gavage. The next day eCG (10 IU) was injected sc to stimulate follicular development. Fifty-two hours after eCG, 10 IU hCG was given to induce ovulation. TCDD (20 microg/kg) blocked ovulation and reduced ovarian weight in IHR. Concentrations of progesterone (P4), androstenedione (A4), and estradiol (E2) in sera and ovaries were not altered by TCDD at 12, 24, 48, and 72 h after eCG. except for a two-fold increase in ovarian concentration of A4 at 48 h after TCDD. However, this higher concentration of A4 at 48 h after TCDD did not reflect that of A4 in sera and did not correlate with E2 in either sera or ovaries. In isolated GC from untreated IHR, TCDD (0.1 to 100 nM) had no significant effect on P4 and E2 after stimulation by LH or FSH. In TIC and whole ovarian dispersates containing GC, TIC, and other ovarian cells, TCDD (0.1 to 800 nM) had no effect on A4 and P4 secretion stimulated by LH. Using RT-PCR, AhR mRNA was shown to be expressed constitutively in the whole ovary of IHR with maximum down-regulation at 6 h after TCDD (20 microg/kg). Ovarian CYP1A1 was induced maximally at 6 h after TCDD, whereas CYP1B1 could not be detected. The induction of AhR related genes by TCDD in the ovary implies the existence of AhR-mediated signal transduction pathways. In summary, these results indicate that TCDD does not affect ovulation in IHR by altering ovarian steroidogenesis. It seems that inhibition of ovulation by TCDD is due to processes related to follicular rupture.

Opioid modulation of the fetal hypothalamic-pituitary-adrenal axis: the role of receptor subtypes and route of administration.

The role of receptor subtypes in opioid modulation of the hypothalamic-pituitary-adrenal (HPA) axis is well understood in the adult but has not been investigated in the developing fetus. Because the fetal HPA axis plays an important role in the development of several vital organs and in the onset of parturition, an understanding of the role of opioid receptor subtypes on the fetal HPA axis is important in the design of new obstetrical analgesics. In these studies, we examined the effects of highly selective mu, delta and kappa opioid agonists on plasma immunoreactive adrenocorticotropin (ir-ACTH) and immunoreactive cortisol (ir-cortisol) in the ovine fetus. Intravenous administration of the mu selective agonist [D-Ala2-N-Me-Phe4,Gly-ol]-enkephalin resulted in a 92% increase in ir-ACTH (P = .005) and ir-cortisol. The delta selective agonist, [D-Pen2,D-Pen5]-enkephalin, elicited a much smaller increase (52%) in ir-ACTH (P = .01). In contrast, there was a 7-fold increase in ir-ACTH (P < .001) and a significant increase in ir-cortisol (P = .02) with the kappa selective U50,488H. When the same agonists were administered intracerebroventricularly, there was no change in ir-ACTH or ir-cortisol. These data suggest that the kappa opioid receptor may be more important in the modulation of the fetal HPA axis and that the distribution of these opioid agonists from the lateral ventricle to the hypothalamus and pituitary is very limited.