Effect of hCG Stimulation on Plasma Androstenone Concentrations and Cytochrome b5 Levels in Testicular Tissue

The effect of Human chorionic gonadotropin (hCG) stimulation on the concentrations of free and conjugated androstenone in plasma was studied in 34 crossbred entire male pigs (Landrace x Swedish Yorkshire). Seventeen pigs were treated with hCG 4 days prior to slaughter and the remaining pigs were treated with sterile saline and served as controls. Blood samples were taken prior to hCG or saline injection and on the day before slaughter and analysed for concentrations of free and conjugated androstenone. Testicular tissue samples were taken at slaughter and analysed for the levels of cytochrome b5 (cyb5) protein. Here we have demonstrated for the first time that hCG stimulation causes an increase in the plasma levels of both free and conjugated androstenone. Not all animals responded in the same way to hCG treatment regarding levels of free and conjugated androstenone demonstrating that individual animals can have differences in their capacity to produce free and conjugated androstenone. We suggest that hCG treatment is a good way to determine the potential for androstenone conjugation when androstenone synthesis in the testis is high. The levels of cyb5 protein in the testis were slightly related (r=0.41, p < 0.10) to free androstenone levels in the pigs after hCG administration, although levels of cyb5 protein were not affected by hCG treatment.     

Ultrasonographic Characteristics of Ovulatory Follicles and Associated Endocrine Changes in Cyclic Ewes Treated with Medroxyprogesterone Acetate (MAP)-releasing Intravaginal Sponges and Equine Chorionic Gonadotropin (eCG)

The aim of this study was to assess the ultrasonographic characteristics of ovulatory follicles in cyclic Western White Face ewes (December) that had received intravaginal sponges containing medroxyprogesterone acetate (MAP; 60 mg) for 12 days, with or without an injection of 500 IU of equine chorionic gonadotropin (eCG) at sponge removal. We hypothesized that quantitative echotextural attributes of the follicles in ewes treated only with MAP would differ from those in MAP/eCG-treated ewes, reflecting the increased antral follicular growth and secretory function under eCG influence. Digital images of ovulatory follicles obtained at 0 and 24 h after MAP sponge removal and at 24 h before ovulation in the eCG-treated (five ewes, 13 follicles) and control (six ewes, 9 follicles) animals, were subjected to computerized analyses. The mean diameter of ovulatory follicles increased (p < 0.001) 24 h after eCG treatment. The mean pixel intensity and heterogeneity of the follicular antrum (p < 0.001), as well as mean pixel intensity of the follicular wall and perifollicular ovarian stroma (p < 0.05), were greater in eCG-treated animals compared with control ewes 24 h after sponge removal and at 24 h before ovulation. Mean serum concentrations of oestradiol-17beta tended to increase (p = 0.06) 24 h after eCG treatment and the eCG-treated ewes exceeded (p < 0.05) control animals in progesterone concentrations from days 9-15 after ovulation. Our results support the hypothesis that large antral follicles in eCG-treated ewes exhibit distinctive echotextural characteristics. Follicular image attributes in eCG-treated ewes appear to be indicative of the changes in follicular morphology and secretory activity caused by the administration of the exogenous gonadotropin, which has both FSH- and LH-like activities.     

Synchronous climate changes in antarctica and the north atlantic

Central Greenland ice cores provide evidence of abrupt changes in climate over the past 100,000 years. Many of these changes have also been identified in sedimentary and geochemical signatures in deep-sea sediment cores from the North Atlantic, confirming the link between millennial-scale climate variability and ocean thermohaline circulation. It is shown here that two of the most prominent North Atlantic events-the rapid warming that marks the end of the last glacial period and the Bolling/Allerod-Younger Dryas oscillation-are also recorded in an ice core from Taylor Dome, in the western Ross Sea sector of Antarctica. This result contrasts with evidence from ice cores in other regions of Antarctica, which show an asynchronous response between the Northern and Southern Hemispheres.     

Canine mammary mixed tumours: immunohistochemical expressions of EGFR and HER‐2

Background Benign mixed tumours (BMTs) are frequently found in the mammary glands of female dogs, but the factors determining malignant transformation in these tumours are unknown. Objective To evaluate the expression of the oncoproteins, human epidermal growth factor receptor 2 (HER‐2) and epidermal growth factor receptor (EGFR), in 46 carcinomas in BMTs (CBMTs) and to verify their possible association with the malignancy of the tumours. Methods Immunohistochemical expression was analysed in benign and malignant components separately, and then compared with 74 cases of BMTs. Results Among the CBMTs, positivity for HER‐2 was found in the benign histological component of 4.3% (2/46), in the malignant epithelial non‐invasive component of 14.8% (4/27) and in the malignant invasive epithelial component of 13.6% (6/44) of cases. Two of the 24 (8.3%) BMTs were positive for HER‐2. There was no relationship between HER‐2 and the tumour components. There was no significant difference between BMTs and CBMTs. Positivity for EGFR was found in the benign component of 17.4% (8/46) of the CBMTs, in the malignant epithelial non‐invasive component of 40.7% (11/27%) and in the invasive epithelial malignant component of 45.4% (20/44). EGFR positivity was significantly associated with the invasive component of CBMTs. Conclusion EGFR may contribute to malignant epithelial transformation of BMTs. In contrast, HER‐2 overexpression may not be associated with the acquisition of a malignant epithelial phenotype.     

Differential Rotation and Dynamics of the Solar Interior

Splitting of the sun's global oscillation frequencies by large-scale flows can be used to investigate how rotation varies with radius and latitude within the solar interior. The nearly uninterrupted observations by the Global Oscillation Network Group (GONG) yield oscillation power spectra with high duty cycles and high signal-to-noise ratios. Frequency splittings derived from GONG observations confirm that the variation of rotation rate with latitude seen at the surface carries through much of the convection zone, at the base of which is an adjustment layer leading to latitudinally independent rotation at greater depths. A distinctive shear layer just below the surface is discernible at low to mid-latitudes.     

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.     

Temperature and exposure time during ethylene conditioning affect ripening of Bartlett pears

Freshly harvested early- and mid-season Bartlett pears (Pyrus communis) were treated with ethylene (air plus 10 Pa C(2)H(4)) or air at 5, 10, and 20 degrees C for 24 and 48 h (experiment 1) and at 5 and 10 degrees C for 48, 72, and 96 h and at 20 degrees C for 24 h (experiment 2). Following C(2)H(4) or air treatment at different temperatures and durations, pears were transferred to 20 degrees C in air for ripening. Bartlett pears were evaluated for firmness, color, respiration, C(2)H(4) production, and activities of 1-aminocyclopropane-1-carboxylic acid synthase (ACC-S) and 1-aminocyclopropane-1-carboxylic acid oxidase (ACC-O). Ethylene action was temperature dependent. The duration of C(2)H(4) conditioning needed to fully induce ripening was longer at lower temperatures: 72 h at 5 degrees C, 48 h at 10 degrees C, and 24 h at 20 degrees C. Cold storage in air for as little as 3-4 days at 5 or 10 degrees C appeared to hasten subsequent ripening, but to a lesser extent than pears kept for 2 weeks at -1 degrees C in air. Despite a significant increase in ACC-S activity in pears treated with C(2)H(4) at 5 degrees C, there was not a simultaneous increase in ACC-O activity, resulting in low C(2)H(4) production that was insufficient to generate the threshold endogenous levels of C(2)H(4) required for ripening. Contrary to previous findings with pears, these data indicate that ACC-O could be a rate-limiting step in C(2)H(4) biosynthesis.