Short-term urea feeding decreases in vitro hatching of bovine blastocysts

Cows fed high-protein diets may have impaired reproductive performance. Although the pathogenesis has not been completely elucidated, it appears that not only the uterus, but also the follicle and oocyte, are affected by excessive plasma urea nitrogen (PUN) concentrations. Thus, the objective was to determine the effects of short-term urea feeding on the competence of bovine oocytes. Forty crossbred heifers (Bos indicus vs Bos taurus) were allocated to two groups, namely CONTROL (maintenance diet) and UREA (maintenance diet supplemented with 75 g of urea/day), following a cross-over design. Heifers received their respective diets for 6 d (without adaptation). On the sixth day, blood samples were harvested both before and 3 h after feeding, and cumulus oocyte complexes (COCs) were collected by ovum pick-up. Although PUN concentrations were higher in UREA than CONTROL heifers (31.31 mg/dL +/- 1.13 vs 22.12 mg/dL +/- 0.86; mean +/- SEM), neither the number of COCs recovered (8.8 +/- 1.0 vs 9.2 +/- 0.8, UREA vs CONTROL, respectively) nor their quality (based on morphology) differed significantly between groups. Next, oocytes were fertilized and cultured in vitro to assess developmental rates. There was an absence of significant differences between groups for rates of cleavage (Day 3) or blastocyst formation (Days 6, 7 and 9), but the hatched blastocyst rate on Day 11 after fertilization was lower (P < 0.05) in the UREA than the CONTROL groups (64.3 vs 83.5%). Therefore, we inferred that the effects of urea were only manifest later in development. In conclusion, high PUN concentrations decreased oocyte competence in heifers, reinforcing the hypothesis that poor reproductive performance in cows with high PUN was due, at least in part, to a deleterious effect on oocytes. (C) 2011 Elsevier Inc. All rights reserved.

Effects of Ethanol on Synthesis of Prostaglandin F2 alpha in Bovine Females

Ethanol stimulates the production of prostaglandins in many species. The purpose of this study was to verify the effect of ethanol on the production of prostaglandin F2 alpha (PGF2 alpha) and luteolysis in bovine females. In the first experiment, Holstein cows at day 17 of the oestrous cycle were treated with 100% ethanol (0.05 ml/kg of body weight, IV; n = 5), saline (0.05 ml/kg of body weight, IV; n = 4) or synthetic prostaglandin (150 mu g of D-cloprostenol/cow, IM; n = 4). The plasma concentrations of 13, 14-dihydro-15-keto PGF2 alpha (PGFM; the main metabolite of PGF2 alpha measured in the peripheral blood) were assessed by radioimmunoassay (RIA). There was an acute release of PGFM in response to ethanol comparing to other treatments (p <= 0.05). However, only cows treated with PGF2 alpha underwent luteolysis. In the second experiment, endometrial explants of cross-bred beef cows (n = 4) slaughtered at day 17 of the oestrous cycle were cultured for 4 h. During the last 3 h, the explants were cultured with medium supplemented with 0, 0.1, I, 10 or 100 mu l of 100% ethanol/ml. Medium samples were collected at hours 1 and 4 and concentrations of PGF2 alpha were measured by RIA. Ethanol did not induce PGF2 alpha production by the endometrium. In conclusion, ethanol does not cause luteolysis in cows because it stimulates production of PGF2 alpha in extra-endometrial tissues.

Influence of curing protocol on selected properties of light-curing polymers: Degree of conversion, volume contraction, elastic modulus, and glass transition temperature

Objectives. The purpose of this study was to investigate the effect of light-curing protocol on degree of conversion (DC), volume contraction (C), elastic modulus (E), and glass transition temperature (T(g)) as measured on a model polymer. It was a further aim to correlate the measured values with each other. Methods. Different light-curing protocols were used in order to investigate the influence of energy density (ED), power density (PD), and mode of cure on the properties. The modes of cure were continuous, pulse-delay, and stepped irradiation. DC was measured by Raman micro-spectroscopy. C was determined by pycnometry and a density column. E was measured by a dynamic mechanical analyzer (DMA), and T(g) was measured by differential scanning calorimetry (DSC). Data were submitted to two-and three-way ANOVA, and linear regression analyses. Results. ED, PD, and mode of cure influenced DC, C, E, and T(g) of the polymer. A significant positive correlation was found between ED and DC (r = 0.58), ED and E (r = 0.51), and ED and T(g) (r = 0.44). Taken together, ED and PD were significantly related to DC and E. The regression coefficient was positive for ED and negative for PD. Significant positive correlations were detected between DC and C (r = 0.54), DC and E (r = 0.61), and DC and T(g) (r = 0.53). Comparisons between continuous and pulse-delay modes of cure showed significant influence of mode of cure: pulse-delay curing resulted in decreased DC, decreased C, and decreased T(g). Influence of mode of cure, when comparing continuous and step modes of cure, was more ambiguous. A complex relationship exists between curing protocol, microstructure of the resin and the investigated properties. The overall performance of a composite is thus indirectly affected by the curing protocol adopted, and the desired reduction of C may be in fact a consequence of the decrease in DC. (C) 2009 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Evaluation of chronic omega-3 fatty acids supplementation on behavioral and neurochemical alterations in 6-hydroxydopamine-lesion model of Parkinson`s disease

Omega-3 polyunsaturated fatty acids (omega-3 PUFAs) have been widely associated to beneficial effects over different neuropathologies, but only a few studies associate them to Parkinson`s disease (PD). Rats were submitted to chronic supplementation (21-90 days of life) with fish oil, rich in omega-3 PUFAs, and were uni- or bilaterally lesioned with 4 mu g of the neurotoxin 6-hydroxydopamine (6-OHDA) in the medial forebrain bundle Although lipid incorporation was evidenced in neuronal membranes, it was not sufficient to compensate motor deficits induced by 6-OHDA. In contrast, omega-3 PUFAs were capable of reducing rotational behavior induced by apomorphine, suggesting neuroprotection over dyskinesia The beneficial effects of omega-3 PUFAs were also evident in the maintenance of thiobarbituric acid reactive substances index from animals lesioned with 6-OHDA similar to levels from SHAM and intact animals. Although omega-3 PUFAs did not modify the tyrosine hydroxylase immunoreactivity in the substantia nigra pars compacta and in the ventral tegmental area, nor the depletion of dopamine (DA) and its metabolites in the striatum, DA turnover was increased after omega-3 PUFAs chronic supplementation Therefore, it is proposed that omega-3 PUFAs action characterizes the adaptation of remaining neurons activity. altering striatal DA turnover without modifying the estimated neuronal population. (C) 2009 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved

Evaluation of estrogen neuroprotective effect on nigrostriatal dopaminergic neurons following 6-hydroxydopamine injection into the substantia nigra pars compacta or the medial forebrain bundle

Studies involving estrogen treatment of ovariectomized rats or mice have attributed to this hormone a neuroprotective effect on the substantia nigra pars compacta (SNpc) neurons. We investigated the effect of estradiol replacement in ovariectomized rats on the survival of dopaminergic mesencephalic cell and the integrity of their projections to the striatum after microinjections of 1 mu g of 6-hydroxydopamine (6-OHDA) into the right SNpc or medial forebrain bundle (MFB). Estradiol replacement did not prevent the reduction either in the striatal concentrations of DA and metabolites or in the number of nigrostriatal dopaminergic neurons following lesion with 1 mu g of 6-OHDA into the SNpc. Nevertheless, estradiol treatment reduced the decrease in striatal DA following injection of 1 mu g of 6-OHDA into the MFB. Results suggest therefore that estrogen protect nigrostriatal dopaminergic neurons against a 6-OHDA injury to the MFB but not the SNpc. This may be due to the distinct degree of lesions promoted in these different rat models of Parkinson`s disease.

Solubility of Epiphany Endodontic Sealer Prepared with Resinous Solvent

Purpose: To evaluate in vitro the solubility of the Epiphany endodontic filling material Epiphany (Pentron Clinical Technologies, Wallingford, CT) prepared with its resinous solvent. Methods: The specimens were prepared in the following experimental conditions: (1) GI, epiphany without photoactivation; (2) GII, Epiphany prepared with resinous solvent without photoactivation; (3) Gill, Epiphany followed by photoactivation; and (4) GIV, Epiphany prepared with resinous solvent followed by photoactivation. Ten specimens of each group were obtained from Teflon molds with 80% reduction in volume of the specimen`s dimensions based on American National Standard Institute/American Dental Association (ANSI/ADA) Specification No. 57. The samples were weighted and immersed in distilled water for 7 days. After this period, they were removed, dried, and weighed again. Solubility was calculated by using samples weight loss (%). The immersion liquid was evaluated through atomic absorption spectrometry. Results: The sealers without photoactivation were statistically similar (p > 0.05) between themselves (GI = 6.93% and GII = 6.39%) and different from the uncured sealers, which were statistically different between themselves (p < 0.05) (GIII = 3.56% and GIV = 0.47%). Only the Epiphany sealer prepared with resinous solvent followed by photoactivation presented solubility values within ANSI/ADA requirements, liberating the following amounts of ions: 114.43 mu g of Ca(2+)/mL, 2.4 mu g of Mg(2+)/mL, 0.33 mu g of Fe(2+)/mL, 0.11 mu 4g of Zn(2+)/mL, 1.31 mu g of Ni(2+)/mL, and 7.1 mu g of Na(+)/mL. Conclusion: The association of resinous solvent to the Epiphany sealer followed by photoactivation resulted in a filling material with low solubility and expressive liberation of calcium ions. (J Endod 2009;35:715-718)

Acquired central diabetes insipidus in children: A 12 year Brisbane experience

Objective: To study the clinical, endocrine and radiological features and progress of children presenting with acquired diabetes insipidus (CDI). Methodology: Chart review of children presenting because of CDI to Brisbane paediatric endocrine clinics between 1987 and 1999. Results: Thirty-nine children (female/male ratio 21/18) aged 0.1-15.4 years (mean age 6.7 years) were identified. Aetiologies were head trauma or familial in eight cases (20.5%) each, central nervous system (CNS) tumours in five cases (12.8%), CNS malformations in four cases (10.2%), histiocytosis in three cases (7%) and hypoxia and infection in two cases (5.1%) each. Seven cases (17.9%) remain undiagnosed. Of the 32 (82%) cases with isolated anti-diuretic hormone deficiency at presentation, 24 cases (61.5%) experienced no further endocrine deficit. Additional endocrine deficits occurred mainly in the tumour or undiagnosed groups. On follow-up brain magnetic resonance imaging (MRI) scans in the seven undiagnosed cases, six patients bad mild or no change and one patient had marked improvement of MRI findings. These changes occurred 10-48 months (mean 18 months) after presentation. Conclusions: Children without an aetiological diagnosis for the uncommon condition of acquired CDI require careful follow-up. More intensive investigation at presentation (e.g. estimation of cerebrospinal fluid human chorionic gonadotrophin) promises to lessen the number of such cases. Pituitary stalk biopsies should be reserved for those patients with progressive MRI changes. If these changes do not occur early, our experience suggests that follow-up MRI scans may need to be performed only yearly.

Anxious futures: Magpie2 and 'new generationalism' in Australian youth-specific theatre

The field of contemporary youth-specific theatre in Australia is one of change and, in some cases, anxiety. While Drama Studies continue to grow in popularity in schools, previously conventional developmental paradigms have become less mandatory for theatre, for, by, and about young people outside the school context. Instead, 'new generation' approaches in youth-specific performance are placing greater value on young people's own preferences in cultural activity. Yet this development is being tempered and further complicated by a cultural 'generationalism', particularly in larger arts organization as the youth sector becomes a more integral part of marketing strategies for the future. The resulting ambiguity in the representation, value, and positioning of young people and youth-specific arts in Australia's theatre industry is considered by focusing on Magpie2, a former youth-specific company attached to the State Theatre Company of South Australia. Magpie2 ceased operation in 1998 after experimenting with a 'new generation' approach to theatre for young people in the State Theatre realm. Both the artistic policy of Magpie2 Director, Benedict Andrews, and the critical reception of his two productions in 1997, Future Tense and Features of Blown Youth, demonstrate how competing systems of cultural value characterize the field of youth-specific theatre in Australia.

Television and cultural studies: Unfinished business

This introductory article argues that the current state of debate on television within cultural studies is marked by considerable areas of theoretical and political uncertainty. The spread of deregulatory and privatizing public policies in relation to television, and the disarticulation of television from the idea of the national community and from the role of the citizen, have posed new problems for theorizing the relation between television and its audiences. In this article I survey a number of key areas of debate: the relation between television, the nation and the state; television and the citizen/consumer, television content and performance, and the likely future(s) of television.

Presentations of physical illness in people with developmental disability: the example of gastro-oesophageal reflux

People with developmental disabilities are becoming an important part of the general practice population. Although they have a similar range of medical conditions to the general population, there are some important differences in prevalence, risk factors, presentation and management of particular conditions. We use gastro-oesophageal reflux to illustrate how developmental disability may affect the presentation, assessment and management of a common condition.

Developing biodegradable mulch films from starch-based polymers

This paper examines the development of starch-based plastics for use as biodegradable mulch film. A variety of starch-based polymers are blended with high performance biodegradable polyester polymers in order to determine the applicability of films to be processed on a film blowing line and to perform well in mulch film field trials. The process of material formulation, film blowing processing and scale-up and performance properties are highlighted for a successful material. Insights into future developments of starch-derived biodegradable polymers are given.

Acute symptoms, not rectally administered sucralfate, predict for late radiation proctitis: Longer term follow-up of a phase III trial - trans-Tasman radiation oncology group

Image : To assess the potential for sucralfate administered rectally to reduce the risk of late rectal morbidity in patients undergoing nonconformal radiotherapy (RT) for carcinoma of the prostate and to study the variables potentially contributing to late rectal morbidity and particularly to explore the relationship between acute and late toxicity. Image : Eighty-six patients with localized prostate carcinoma were randomized in a double-blind, placebo-controlled study to a daily enema of 3 g of sucralfate in a 15-mL suspension or the same suspension without sucralfate. The enema began the first day of RT and was continued for 2 weeks after treatment completion. The primary end point of the study was acute Radiation Therapy Oncology Group (RTOG)/European Organization for Research and Treatment of Cancer (EORTC) toxicity; however, the patients were followed for an additional 5 years on a 6-month basis. The evaluation included late RTOG/EORTC toxicity and a patient self-assessment questionnaire. Image : With a median follow-up of 5 years, the Kaplan-Meier probability of late Grade 2 RTOG/EORTC toxicity was 12% (95% confidence interval [CI] 2–22%) for placebo and 5% (95% CI 0–12%) for sucralfate (p = 0.26). The probability of late rectal bleeding was 59% (95% CI 45–73%) for placebo and 54% (95% CI 40–68%) for sucralfate. No statistically significant difference was found between the treatment arms for the peak incidence of any of the other patient self-assessment variables. Cox proportional hazards modeling indicated acute RTOG/EORTC toxicity of Grade 2 or greater was associated with a hazard ratio of 2.74 (95% CI 1.31–5.73) for the development of late toxicity of Grade 1 or greater. Substituting the patient self-assessment variables for acute RTOG/EORTC toxicity revealed that rectal pain of a moderate or severe grade during RT was the best predictor of the subsequent development of late toxicity, with a hazard ratio of 3.44 (95% CI 1.68–7). Image : The results of this study do not support the use of sucralfate administered rectally as a method for reducing the late toxicity of nonconformal RT for prostate cancer. There appears to be an association between the development of acute and subsequent late toxicity, although the nature of this association remains to be determined

Drop penetration into porous powder beds

The kinetics of drop penetration were studied by filming single drops of several different fluids (water, PEG200, PEG600, and HPC solutions) as they penetrated into loosely packed beds of glass ballotini, lactose, zinc oxide, and titanium dioxide powders. Measured times ranged from 0.45 to 126 s and depended on the powder particle size,viscosity, surface tensions, and contact angle. The experimental drop penetration times were compared to existing theoretical predictions by M. Denesuk et al. (J. Colloid Interface Sci. 158, 114, 1993) and S. Middleman (Modeling Axisymmetric Flows: Dynamics of Films, Jets, and Drops, Academic Press, San Diego, 1995) but did not agree. Loosely packed powder beds tend to have a heterogeneous bed structure containing large macrovoids which do not participate in liquid flow but are included implicitly in the existing approach to estimating powder pore size. A new two-phase model was proposed where the total volume of the macrovoids was assumed to be the difference between the bed porosity and the tap porosity. A new parameter, the effective porosity (epsilon)eff, was defined as the tap porosity multiplied by the fraction of pores that terminate at a macrovoid and are effectively blocked pores. The improved drop penetration model was much more successful at estimating the drop penetration time on all powders and the predicted times were generally within an order of magnitude of the experimental results. (C) 2002 Elsevier Science (USA).

Surface stickiness of drops of carbohydrate and organic acid solutions during convective drying: Experiments and modeling

Drying kinetics of low molecular weight sugars such as fructose, glucose, sucrose and organic acid such as citric acid and high molecular weight carbohydrate such as maltodextrin (DE 6) were determined experimentally using single drop drying experiments as well as predicted numerically by solving the mass and heat transfer equations. The predicted moisture and temperature histories agreed with the experimental ones within 6% average relative (absolute) error and average difference of +/- 1degreesC, respectively. The stickiness histories of these drops were determined experimentally and predicted numerically based on the glass transition temperature (T-g) of surface layer. The model predicted the experimental observations with good accuracy. A nonsticky regime for these materials during spray drying is proposed by simulating a drop, initially 120 mum in diameter, in a spray drying environment.

Biodegradation and ecotoxicity evaluation of a bionolle and starch blend and its degradation products in compost

A polymer based on a blend of starch and Bionolle(TM) has been prepared and tested for biodegradation in compost. The polymer was completely mineralised to carbon dioxide in 45 days. The potential toxicity of the polymer was tested against the earthworm Eisenia fetida using a modification of the American Standard for Testing Materials E1976-97. The earthworms were exposed to 30 g of the polymer for 28 days and changes in weight recorded. In addition, the polymer was firstly degraded by the compost and the worms exposed to the breakdown products for 28 days. Differences in weight were also recorded. In each case the production of juveniles was noted and all earthworms were examined for pathology. The results obtained were processed statistically using a t-test. The number of juveniles, produced from the breakdown products, was highly significant (P < 0.001) when compared to the earthworms added to the intact polymer. There was a definitely significant difference (P < 0.01, t = 3.25) in change in weight between the earthworms that were exposed to the polymer directly and those that were exposed to the breakdown products. There was no indication of any pathology of any earthworms. The polymer is considered safe for this species. (C) 2002 Elsevier Science Ltd. All rights reserved.