Lectin‐Binding Pattern in Ovarian Structures of Rats with Experimental Polycystic Ovaries

Numerous experimental models in different species have been developed for the study of polycystic ovarian syndrome. In this study, we used a model of induction of polycystic ovaries (PO) in rats by exposure to constant light to study the distribution and variations of glycosylated residues present in the different ovarian structures. Seven biotinylated lectins were used (Con‐A, WGA, DBA, SBA, PNA, RCA and UEA‐I) on tissue sections, and detection was performed using the streptavidin/peroxidase method. In tissue sections was observed an increase in affinity for Con‐A in the granulosa and theca interna of growing follicles and cysts in animals with PO in relation to the control group. Follicular cysts showed higher affinity for WGA and RCA‐I which growing follicles in the same group, and there was a decrease in affinity for PNA in the cysts in relation to the growth of follicles in both groups. Atretic follicles in both groups showed greater labelling with lectins PNA, SBA and RCA‐I in relation to healthy follicles. It could also be noted that the zona pellucida of cystic follicles lost the affinity for the lectin Con‐A. There was no staining on follicles in any category with the lectins DBA and UEA‐I, although it was staining in the corpus luteum (control group) and in the mesothelium and interstitial glands of both groups with DBA. These observations probably reflect changes in the glycosaminoglycans present in the different ovarian compartments or in the glycosylation of cellular components essential for proper follicular dynamics.     

The magnetic field of the Large Magellanic Cloud revealed through Faraday rotation

We have measured the Faraday rotation toward a large sample of polarized radio sources behind the Large Magellanic Cloud (LMC) to determine the structure of this galaxy's magnetic field. The magnetic field of the LMC consists of a coherent axisymmetric spiral of field strength approximately 1 microgauss. Strong fluctuations in the magnetic field are also seen on small (<0.5 parsec) and large (approximately 100 parsecs) scales. The large bursts of recent star formation and supernova activity in the LMC argue against standard dynamo theory, adding to the growing evidence for rapid field amplification in galaxies.     

Intermediate Filament Proteins Expression and Carbohydrate Moieties in Trophoblast and Decidual Cells of Mature Cat Placenta

The aim of this study was to characterize cytoskeletal intermediate filament proteins and glycoconjugates of syncytiotrophoblast, cytotrophoblast and decidual cells of feline endotheliochorial placenta. Samples from 12 normal pregnant female cats, after 45 ± 5 days of gestation, were obtained removing the uterine horns by hysterectomy. Sections were processed for routine observation and for immunohistochemistry using anticytokeratin, antivimentin and antidesmin antibodies. In addition, lectin histochemistry was performed using a panel of several biotinylated lectins to characterize glycosides expression profile. Cytotrophoblast and syncytiotrophoblast showed immunoreactivity only with acidic and basic cytokeratins. Decidual cells were only positive to vimentin, consistent with their origin from endometrial fibroblasts. Trophoblast expressed a broad population of glycans, highly exposing terminal N‐acetyl glucosamine residues and non‐sialylated galactose and N‐acetyl galactosamine oligomers. Oligosaccharides bound by Phaseolus vulgaris erythroagglutinin were the only highly branched N‐linked residues evidenced in cats, and they were restricted to the syncytium. Unlike results reported on humans, mice and rats on lectin affinity of decidual cells, sialid acids and complex N‐linked oligosaccharides were not demonstrated in cats. Glycosylation of proteins determines many of their final properties, thus becoming essential for the embryo‐maternal dialogue during implantation and placentation. Changes in glycosylation pattern have been related to pathological pregnancies in other species. Hence, the knowledge about glycosylation profile of the normal cat placenta may lead to a better understanding of both normal and pathological reproductive events.     

Lectin‐binding Sites on the Normal and Pathologic Uterus of Sows

The lectin‐binding pattern was compared in the normal and pathological uterus of sows during the ovarian cycle. The following biotinylated lectins were used: Con A, DBA, SBA, PNA, RCA‐I, UEA‐I and WGA. Glycoconjugate labelling showed differences between phases of ovarian cycle and presence of morphologic lesions. Cystic endometrial hyperplasia increased the RCA‐I reaction in the apical region of the glandular epithelium. There was higher intensity of labelling of WGA in the glandular epithelium in uteri with endometritis. In addition, increased Con A binding in the glandular epithelium and mild reduction of UEA‐I reactivity in the glycocalyx of the glandular epithelium were detected in the cases of endometritis. The results of this study show that morphologic alterations modify the sugar pattern in the porcine uterus. These modifications in glycoconjugates may be one of the reasons for decreased fertility in sows.     

Farm management factors associated with bulk tank somatic cell count in Irish dairy herds

The relationship between bulk tank somatic cell count (SCC) and farm management and infrastructure was examined using data from 398 randomly selected, yet representative, Irish dairy farms where the basal diet is grazed grass. Median bulk tank SCC for the farms was 282,887 cells/ml ranging from 82,209 to 773,028 cells/ml. Two questionnaires were administered through face-to-face contact with each farmer. Herd-level factors associated with bulk tank SCC were determined using linear models with annual somatic cell score (i.e., arithmetic mean of the natural logarithm of bulk tank SCC) included as the dependent variable. All herd level factors were analysed individually in separate regression models, which included an adjustment for geographical location of the farm; a multiple regression model was subsequently developed. Management practices associated with low SCC included the use of dry cow therapy, participation in a milk recording scheme and the use of teat disinfection post-milking. There was an association between low SCC and an increased level of hygiene and frequency of cleaning of the holding yard, passageways and cubicles. Herd management factors associated with bulk tank SCC in Irish grazing herds are generally in agreement with most previous studies from confinement systems of milk production.     

Effect of unilateral castration and unilateral cryptorchidism on gonadotropin and testosterone response to gonadotropin releasing hormone in the bull

The effects of unilateral castration (UC) and induced unilateral cryptorchidism (UCR) on basal plasma luteinizing hormone (LH), follicle stimulating hormone (FSH) and testosterone, and on the responses of these hormones to gonadotropin releasing hormone (GnRH), were investigated in bulls altered at 3, 6 or 9 months of age. Blood plasma was collected before and after GnRH (200 micrograms) stimulation approximately 1 year following gonadal manipulation. Neither mean baseline concentrations nor GnRH-induced increases in plasma testosterone were altered (P greater than .1) by hemicastration or UCR (P greater than .1). Both mean baseline LH and GnRH-induced LH release were greater (P less than .05) in bulls altered at 3 months of age than in bulls altered at 9 months of age. UC increased (P less than .05) plasma LH response to GnRH over that observed in intact bulls, but not above that in UCR bulls. UCR had no detectable effect on either baseline concentrations or GnRH-stimulated LH release. FSH was increased (P less than .05) in hemicastrates, while UCR had a variable effect on peripheral FSH: FSH was reduced (P less than .05) in UCR animals altered at 3 months of age but increased (P less than .05) in UCR bulls altered at both 6 and 9 months of age when compared to FSH in intact bulls. The results indicate that, compared with intact bulls, UC bulls release increased amounts of both gonadotropins but similar amounts of testosterone in response to GnRH stimulation. UCR had a variable effect on FSH release and did not alter either LH or testosterone.     

Protein distribution in commercial wet- and dry-milled corn germ

To identify high-valued coproducts from commercially processed corn germ, it was necessary to determine the effect of processing conditions on corn germ proteins. We found that significantly less protein was extracted from commercial wet-milled as compared to dry-milled corn germ using Tris, sodium dodecyl sulfate (SDS) buffer containing 14 mM 2-mercaptoethanol at 100 degrees C for 10 min. SDS-polyacrylamide gel electrophoresis (PAGE) revealed a number of proteins with molecular masses ranging from approximately 10 to 66 kDa for the dry-milled corn germ as compared to only a few significant protein bands centered around 23 kDa in the wet-milled corn germ. The protein content of the wet- and dry-milled corn germ was approximately the same; however, nonprotein nitrogen values were significantly greater for the wet-milled than for the dry-milled germ. The distribution of fractionated germ protein freshly excised from the embryo of yellow dent corn kernels was more similar to that of dry-milled than wet-milled corn. SDS-PAGE of laboratory preparations of wet-milled corn germ more closely resembled commercial dry- than wet-milled corn germ, which could be attributed to limited microbial growth during steeping in the laboratory preparations.