Endometrial expression of members of the IL-1 family: their involvement in delayed conception of dairy cows.

The cytokines of the interleukin-1 (IL-1) family are closely involved in the resolution of inflammation in cows with metritis and endometritis. However, little is known about the role of these cytokines beyond uterine regression in the absence of disease, especially around conception. Thus, the aim of this study was to examine the gene and protein expression of IL-1α, IL-1ß, IL-1RI, IL-1RII and IL-1Ra in endometrial biopsies previous to conception, to evaluate the possible association of these cytokines with delayed conception in dairy cows. Gene and protein expression levels were evaluated by real-time PCR and immunohistochemistry, respectively. The gene expression levels of cytokines were not associated with the duration of the period to conception following parturition. However, high protein expression of IL-1ß and low protein expression of IL-1Ra were significantly associated with early conception. These results suggest that an imbalanced protein expression of IL-1ß and IL-1Ra in the endometrium of dairy cows could be part of the maternal immune response mechanism necessary to propitiate early conception and probably to maintain pregnancy.

A review on inflammation and angiogenesis as key mechanisms involved in the pathogenesis of bovine cystic ovarian disease.

Cystic ovarian disease (COD) is an important cause of reproductive failure in dairy cattle. The main aim of this review is to discuss some aspects related to inflammation and angiogenesis that seem to be involved in the development of follicular cysts in domestic animals, with special emphasis on the bovine species, in an attempt to elucidate the relationship between these two processes in the early stages of persistence and in the development of bovine COD. We describe the changes in the expression of cytokines and angiogenic factors that seem to generate disturbances in the intraovarian component underlying the aberrant persistence of follicular cysts. Results show that pro-inflammatory and anti-inflammatory cytokines behave as regulators of angiogenesis through direct and indirect effects, like overexpression of pro-angiogenic factors, particularly in bovine ovarian cells from follicular cysts and persistent follicles. We conclude that, in dairy cattle, an imbalance in the expression of cytokines and pro-angiogenic growth factors related to ovulation and the processes associated with it would contribute to follicular persistence and to the recurrent appearance of COD.

Optimizing the Properties of Hybrids Based on Graphene Oxide for Carbon Dioxide Capture.

The reduction of CO2 emissions and its elimination from the atmosphere has become one of the major problems worldwide, since CO2 is the main cause of the greenhouse effect and climate change. In recent years, a great number of carbonaceous materials that can be used as CO2 adsorbents have been synthesized. The strategy is usually to synthesize the materials and determine their adsorption capacity without studying previously the factors that influence this capacity. In this work, different properties of the adsorbents are analyzed to study their influence on the CO2 adsorption capacity. For this purpose, 10 adsorbents have been synthesized using different strategies and characterized with X-ray photoelectron spectroscopy, X-ray diffraction, and micro-Raman spectroscopy. The percentage of sp2 carbons, the position of the D + D' peak of the second-order Raman spectrum, the micropore volume, and the grain size of the C sp2 domains have been related to the amount of CO2 adsorbed by the adsorbents. The results confirm a linear relationship between the volume of the micropores and the CO2 uptake and it proves that CO2 retention is favored in those materials that, in addition to having a high volume of micropores, also have low grain size of C.

Association between phagocytic activity of monocytes and days to conception after parturition in dairy cows when considering the hormonal and metabolic milieu.

The nutritional conditions and immune status of dairy cows affect reproductive performance. This study was conducted with the aim to analyze the phagocytic activity (PA) and phagocytic capacity (PC) of circulating monocytes after the period of transition from pregnancy to lactation, to evaluate possible associations with duration of time period to conception following parturition. Results indicated PA was not associated with duration of time period to conception following parturition. In contrast, cows with a lesser PC conceived earlier (98 ± 9 days in milk, DIM) than those with a greater PC (168 ± 15 DIM). Based on these results, to analyze the association of the hormonal and metabolic milieu with the PA and PC, the animals were grouped considering the days to conception following parturition. In the group with the greater number of days to conception (>168 DIM), the PA was associated with concentrations of progesterone and beta-hydroxybutyrate (BHB) at 90 DIM and glucose at 120 DIM, whereas PC was associated with the concentrations of progesterone, cortisol and glucose at 90 DIM, non-esterified fatty acids (NEFA) at 120 DIM, 17ß-estradiol at 150 DIM, and 17ß-estradiol and BHB at 180 DIM. Overall, these results represent a new perspective related to the reproductive performance of dairy cows. The modifications of cellular functions may be useful for predicting the onset of health complications in dairy cows and to manage cows in ways that result in an enhanced fertility during the subsequent lactational period.

Effects of adrenocorticotrophic hormone on the expression of matrix metalloproteinases and their inhibitors in the bovine ovary.

Cattle undergo numerous environmental and management stressors that reduce fertility and affect ovulation. The extracellular matrix of the follicle wall can be altered by matrix metalloproteinases (MMPs), the activities of which are regulated by interleukins and tissue-specific inhibitors of metalloproteinases (TIMPs), especially during ovulation. The aims of the present study were to: (1) evaluate changes in the hormone milieu, the localisation and activity of MMP2 and MMP9 and the localisation of MMP14, TIMP1 and TIMP2 in response to adrenocorticotrophic hormone (ACTH) during the preovulatory period in cows; and (2) determine the direct effects of ACTH on the mRNA expression of MMP2 and MMP9 in the cultured follicle wall of bovine ovaries obtained from an abattoir. 100IU ACTH was administered during pro-oestrus every 12h until ovariectomy, which was performed before ovulation. Cortisol concentrations in the plasma and follicular fluid (FF) of preovulatory follicles were higher in ACTH-treated than control cows. Progesterone presented subluteal concentrations in plasma of ACTH-treated cows (P<0.05). MMP2 immunostaining and activity in ovaries were higher in ACTH-treated than control cows (P<0.05), whereas MMP9 immunostaining was similar between the two groups. However, unlike in control cows, MMP9 activity was absent in the FF of ACTH-treated cows. These results suggest that the administration of ACTH during the preovulatory period in cows could cause changes that culminate in modifications in the content and activation of MMPs and TIMPs in the ovary, which could interfere with the ovulation process.

Contribution of the VEGF system to the follicular persistence associated with bovine cystic ovaries.

Cystic ovaries (CO) characterize a disorder frequently found in dairy cattle. However, despite the contributions by several researchers, the mechanism that leads to ovulatory failure has not yet been completely elucidated. Thus, the aim of this study was to examine the mRNA expression of bovine vascular endothelial growth factor (VEGFA)-164, VEGFA-164b and VEGF receptors (VEGFR1 and VEGFR2) by real-time PCR and protein expression by immunohistochemistry, immunofluorescence and Western blot in follicular fluid from dairy cows with spontaneous CO and in an experimental model of follicular persistence induced by prolonged treatment with progesterone. Results showed that both VEGFA isoforms and receptors were coexpressed in granulosa and theca interna cells and in follicular fluid of ovaries from all the groups evaluated. VEGFA-164, VEGFA-164b and VEGFR2 protein expression was higher in theca cells of persistent follicles from group P0 (expected time of ovulation) than in those from dominant follicles (as reference structure) from the control group (p < 0.05). Also, VEGFA-164 expression was higher in theca cells of cysts than in those of dominant follicles of the control group (p < 0.05). In follicular fluid, VEGFA-164 expression was higher in persistent follicles from group P5 (5 days of follicular persistence) than in the control, P0 and P15 groups, and higher in cysts than in dominant follicles from the control group (p < 0.05). This study provides evidence of an altered expression of VEGFA-164, VEGFA-164b and VEGFR2 during the formation of persistent follicles and cysts in cows. Together, these results evidence that early development of CO in cows is concurrent with an altered expression of these growth factors and that these alterations may contribute to the follicular persistence, angiogenic dysregulation and ovulatory failure found in cows with follicular cysts.

Immune status during postpartum, peri-implantation and early pregnancy in cattle: An updated view.

Throughout the estrous cycle the mammalian endometrium undergoes morphological and functional changes that are essential for the establishment of pregnancy and proper ovarian and uterine functions. Among these changes, the most important are alterations in both inter- and intracellular signalling molecules, many of which modulate immune processes. In the endometrial tissue there are local innate (nonspecific) and adaptive (specific/acquired) response mechanisms which vary because of the endocrine status during the estrous cycle, pregnancy and postpartum period. Endometrial cells have responses that support the immune system by producing pro-inflammatory factors such as cytokines, sensors, effector molecules and chemokines. This response is important during gestation, pregnancy, and fetal growth, as well as in preventing infection, and immuno-rejection of the semi-allogeneic embryo. In dairy cows, both before and immediately after calving, there are marked changes in the values for hormonal and metabolic variables and the immune status is impaired. Thus, in several studies there has been assessment of the physiological and/or abnormal maternal immune changes and possible effects on dairy cow reproductive performance. The objective with this review is to summarize the novel information about the immune mechanisms involved during the postpartum period, subsequent peri-implantation period and pregnancy in dairy cows, and the possible effects on reproductive performance. This information provides for an enhanced understanding of the local and systemic immune responses associated with the metabolic and hormonal status of dairy cows, and alterations in the immune system of high producing cows and the possible effects on subsequent fertility.

Altered expression of IL-1ß, IL-1RI, IL-1RII, IL-1RA and IL-4 could contribute to anovulation and follicular persistence in cattle.

Cystic ovarian disease (COD) is an important cause of infertility in dairy cattle. The main signs of this infertility are ovulation failure and follicular persistence. The aim of this study was to examine the expression of the cytokines IL-1ß, IL-1RI, IL-1RII, IL-1RA and IL-4 in ovarian follicular structures at different times of persistence in a model of follicular persistence induced by prolonged administration of progesterone in dairy cows. Protein expression of IL-1ß, IL-1RI, IL-1RII, IL-1RA and IL-4 was evaluated by immunohistochemistry. Additionally, IL-1ß and IL-4 concentrations in follicular fluid and serum were determined by ELISA. In granulosa cells, IL1-RII and IL-4 expression was higher in follicles with different persistence times than in the control dominant follicles. IL-1RA expression was higher in persistent follicles of the P15 group (15 days of follicular persistence) than in those of the control group. In theca cells, IL-1RII expression was higher in persistent follicles of the P0 group (expected time of ovulation) than in dominant follicles from the control group (p < .05) and the other persistence groups, whereas IL-4 expression was higher in persistent follicles of groups P0 and P15 than in the dominant follicles of the control group (p < .05). Differences between serum and follicular fluid within each group were detected only in P0 for IL-1ß, and in the control, P10 and P15 groups for IL-4 (p < .05). These results complement previous results, evidencing that early development of COD in cows is concurrent with an altered expression of cytokines in different ovarian follicular structures and may contribute to the follicular persistence and ovulation failure found in cattle with follicular cysts.

Involvement of Matrix Metalloproteinases and their Inhibitors in Bovine Cystic Ovarian Disease.

The most important regulators of tissue remodelling during ovarian follicular growth, development, ovulation and atresia are gonadotropins, steroid hormones, growth factors and different proteolytic enzymes. Matrix metalloproteinases (MMPs) such as collagenase or gelatinase (i.e. MMP-1, -8, -2 and -9) and associated tissue inhibitors of metalloproteinases (TIMP-1, -2, -3 and -4) control connective tissue remodelling during follicular rupture. In this study, we hypothesized that an imbalance in the MMP-TIMP system may be an intra-ovarian component that contributes to the pathogenesis of cystic ovarian disease (COD) in cows. Taking into account that the control of MMP activity by TIMPs could determine their effects in both physiological and pathological conditions, MMP and TIMP mRNA and protein expression was examined by real-time polymerase chain reaction (RT-PCR) and immunohistochemistry (IHC), respectively, in ovaries from control cows and cows with COD. Expression of mRNA encoding MMP-2, TIMP-1 and TIMP-2 was lower in follicular cysts than in control pre-ovulatory follicles, while the results by IHC showed this imbalance only for TIMP-2 protein expression. Additional analysis by zymography to evaluate the gelatinase activity of MMP-2 and MMP-9 demonstrated higher MMP-2 activity in follicular fluid (FF) of cysts than in FF of pre-ovulatory follicles. On the other hand, MMP-9 activity was increased in follicular cysts and absent in the FF of pre-ovulatory follicles. These findings suggest that the altered mRNA expression and activities of the MMP-TIMP system may be related to the failure in ovulation and follicular development observed in COD.

Altered Expression of Pro-inflammatory Cytokines in Ovarian Follicles of Cows with Cystic Ovarian Disease.

A growing body of evidence suggests that ovulation shares many of the features of an inflammatory reaction and that cytokines play many diverse and important roles in reproductive biology. The aim of this study was to examine the expression of the pro-inflammatory cytokines interleukin (IL)-1α, IL-6 and tumour necrosis factor (TNF)-α in ovarian cells from cows with cystic ovarian disease (COD) as compared with that in ovarian structures from regularly cycling cows. Expression of genes encoding IL-1α, IL-6 and TNF-α was detected by real-time polymerase chain reaction in follicular cells from ovaries from healthy cows and cows with COD with no significant differences. However, immunohistochemistry showed increased expression of IL-1α, IL-6 and TNF-α in cystic follicles, suggesting that this expression may be related to the persistence of follicular cysts. The effect of COD was evident for IL-1α and TNF-α, and a follicular structure-disease interaction was observed in the expression of all the cytokines evaluated. Thus, altered expression of these proinflammatory cytokines may be related to ovulation failure and development of follicular cysts.

Modulating the Optoelectronic Properties of Silver Nanowires Films: Effect of Capping Agent and Deposition Technique.

Silver nanowires 90 nm in diameter and 9 µm in length have been synthesized using different capping agents: polyvinyl pyrrolidone (PVP) and alkyl thiol of different chain lengths. The nanowire structure is not influenced by the displacement of PVP by alkyl thiols, although alkyl thiols modify the lateral aggregation of nanowires. We examined the effect of the capping agent and the deposition method on the optical and electrical properties of films prepared by Spray and the Langmuir-Schaefer methodologies. Our results revealed that nanowires capped with PVP and C8-thiol present the best optoelectronic properties. By using different deposition techniques and by modifying the nanowire surface density, we can modulate the optoelectronic properties of films. This strategy allows obtaining films with the optoelectronic properties required to manufacture touch screens and electromagnetic shielding.

Adsorption of quantum dots onto polymer and Gemini surfactant films: a quartz crystal microbalance study.

We used quartz crystal microbalance with dissipation to study the mechanical properties, the kinetics of adsorption, and the amount of CdSe quantum dots (QDs) adsorbed onto a SiO2 sensor, referred as bare sensor, onto the sensor modified with a film of the polymer poly(maleic anhydride-alt-1-octadecene), PMAO, or with a film of the Gemini surfactant ethyl-bis(dimethyl octadecyl ammonium bromide), abbreviated as 18-2-18. Results showed that when the sensor is coated with polymer or surfactant molecules, the coverage increases compared with that obtained for the bare sensor. On the other hand, rheological properties and kinetics of adsorption of QDs are driven by QD nanoparticles. Thus, the QD films present elastic behavior, and the elasticity values are independent of the molecule used as coating and similar to the elasticity value obtained for QDs films on the bare sensor. The QD adsorption is a two-step mechanism in which the fastest process is attributed to the QD adsorption onto the solid substrate and the slowest one is ascribed to rearrangement movements of the nanoparticles adsorbed at the surface.

Hydrogen bonding in a non-steroidal anti-inflammatory drug--Naproxen.

Photophysical properties of a non-steroidal anti-inflammatory drug, Naproxen (6-methoxy alpha-methyl-2-naphthalene acetic acid sodium salt), were investigated in solvents of different polarity, hydrogen donor ability and also in cyclodextrins. The results indicate that in all cases the emitting state is the 1L(b) singlet. In alcoholic solvents, an intermolecular hydrogen bond is responsible for the observed photophysical behaviour of the probe whereas in non-protic solvents (polar and weakly polar) an intramolecular hydrogen bond type is postulated to rationalize the data found. In water, the non-radiative rate constant has a value similar to those found in aqueous solutions of alpha- and beta-cyclodextrins where the probe form complexes. The behaviour in water is explained by a water-structure enforced hydrophobic effect. The spectroscopic results are interpreted on the basis of a multiple-parameter model that considers specific solute-solvent interactions. These were also observed in the ground state and detected by Fourier transform infrared spectroscopy. Molecular mechanics (MM) and molecular orbital (AM1) calculations also support the existence of two conformations (rotamers) in Naproxen with non-equivalent intramolecular hydrogen bond-like formation.

Kinetics of the acid hydrolysis of diazepam, bromazepam, and flunitrazepam in aqueous and micellar systems.

A kinetic study of the acid hydrolysis of aqueous diazepam, bromazepam, and flunitrazepam was carried out at 25 degrees C using a spectrophotometric method. For diazepam and flunitrazepam, the experimental pseudo first-order rate constant decreased as the acid concentration was increased. The contrary behavior was found in the case of bromazepam. A kinetic scheme that includes the hydrolysis reaction of both protonated and nonprotonated species of the drug can account for these results. Also, the kinetics of the acid hydrolysis of the same drugs in the presence of micellar aggregates [nonionic polyoxyethylene-23-dodecanol (Brij 35); cationic cetyl trymethyl ammonium bromide (CTAB); and anionic sodium decyl (SdeS), dodecyl (SDS), and tetradecyl (STS) sulfate] was studied at 25 degrees C. Negligible effects were observed in the cases of nonionic and cationic micelles. Anionic micelles produced an inhibitory effect in the reaction velocity. This effect increased as the hydrophobic nature of the surfactant increased. All these facts are interpreted quantitatively by means of a pseudophase model.

Solubility of diazepam and prazepam in aqueous non-ionic surfactants.

The solubility of diazepam and prazepam in aqueous polyoxyethylen-10-dodecanol, polyoxyethylen-23-dodecanol and polyoxyethylen-20-hexadecanol, has been determined at 25.0 degrees C. Diazepam seems to achieve a higher micellar penetration than prazepam, in spite of an expected smaller hydrophobic character. Thermodynamic interpretation of the micellar solutions is carried out using the regular solutions approach. A surfactant-independent relation between solubilities of both drugs has been derived.