28 research outputs found

    Marketing, art and voices of dissent: promotional methods of protest art by the 2014 Hong Kong’s Umbrella Movement

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    Limited research exists around the interrelationships between protest camps and marketing practices. In this paper, we focus on the 2014 Hong Kong protest camps as a context where artistic work was innovatively developed and imaginatively promoted to draw global attention. Collecting and analyzing empirical data from the Umbrella Movement, our findings explore the interrelationships between arts marketing technologies and the creativity and artistic expression of the protest camps so as to inform, update and rethink arts marketing theory itself. We discuss how protesters used public space to employ inventive methods of audience engagement, participation and co-creation of artwork, together with media art projects which aimed not only to promote their collective aims but also to educate and inform citizens. While some studies have already examined the function of arts marketing beyond traditional and established artistic institutions, our findings offer novel insights into the promotional techniques of protest art within the occupied space of a social movement. Finally, we suggest avenues for future research around the artwork of social movements that could highlight creative and political aspects of (arts) marketing theory

    The recombinant subdomain IIIB of human serum albumin displays activity of gonadotrophin surge-attenuating factor

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    BACKGROUND: Gonadotrophin surge-attenuating factor (GnSAF) is an as yet unidentified ovarian factor that acts on the pituitary to attenuate the pre-ovulatory LH surge. In a previous study, GnSAF bioactivity was proposed to derive, at least in part, from a C-terminal domain (95peptide) of human serum albumin (HSA). METHODS AND RESULTS: We employ here the expression-secretion system of Pichia pastoris to produce and assay selected recombinant polypeptides of HSA for GnSAF activity. We show that the C-terminal 95peptide of HSA (residues 490-585; subdomain IIIB) can be expressed from P.pastoris in secreted form and supernatants from clones expressing this polypeptide reduce the GnRH-induced LH secretion of primary rat pituitary cultures by 50-82%. When expressed in the same system, HSA domain III (residues 381-585) or full-length HSA (residues 1-585) are inactive. The bioactive subdomain IIIB is also separable from either domain III or full-length HSA on Blue Sepharose chromatography. CONCLUSIONS: Taken together, the findings highlight the putative importance of HSA subdomain IIIB as a GnSAF-bioactive entity and introduce a unique experimental tool to engineer this molecule for structure-function analysis

    Treatment of normal women with oestradiol plus progesterone prevents the decrease of leptin concentrations induced by ovariectomy

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    To study the role of oestradiol and progesterone in the secretion of leptin, 21 normally ovulating women were recruited from those scheduled for ovariectomy plus hysterectomy performed in mid-follicular phase of the cycle. Seven of the women were used as controls and received no hormonal treatment post-operatively, Another seven women received oestradiol (oestradiol group) and the remaining seven women received oestradiol plus progesterone (oestradiol plus progesterone group). Serum leptin values showed a temporal but significant increase 24 h after the operation and were significantly correlated with the cortisol and progesterone values, which increased temporarily at 12 h. At that time a marked decline in oestradiol concentrations was seen. After the temporal increase, leptin values in the controls and the oestradiol group decreased significantly up to day 4 (P < 0.05), while in the oestradiol plus progesterone group they increased (P < 0.01) and were significantly higher than in the other two groups (P < 0.05). Body mass index (BMI) was the most important variable accounting for the changes in leptin values post-operatively, but in the oestradiol plus progesterone group progesterone correlated significantly with leptin independently of BMI. These results suggest that progesterone and cortisol can stimulate leptin secretion in women regardless of oestradiol concentrations

    Evidence of differential control of FSH and LH responses to GnRH by ovarian steroids in the luteal phase of the cycle

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    BACKGROUND: It is known that during the follicular phase of the cycle, estradiol sensitizes the pituitary to GnRH. The aim of this study was to determine the role of ovarian steroids in the control of GnRH-induced gonadotrophin secretion in the luteal phase of the cycle. METHODS: Eighteen normally cycling women were studied during the week following bilateral ovariectomy plus hysterectomy performed in early to mid-luteal phase. Six of the women received no hormonal treatment post-operatively (group 1, control), six received estradiol through skin patches (group 2) and the remaining six received estradiol plus progesterone (group 3). In all women the response at 30 min of LH (DeltaLH) and FSH (DeltaFSH) to GnRH (10 mug i.v.) was investigated on a daily basis. RESULTS: In group 1, serum FSH, LH and DeltaFSH values increased progressively following ovariectomy, while in groups 2 and 3 this increase was postponed or abolished. In contrast to DeltaFSH, DeltaLH values showed the same pattern of changes in all three groups with a significant decline up to post-operative day 4 and a gradual increase thereafter. CONCLUSIONS: These results demonstrate, for the first time, that in the early to mid-luteal phase of the cycle, estradiol and progesterone participate in the control of GnRH-induced FSH, but not LH, secretion. It is possible that in the luteal phase, the response of LH to GnRH is partly regulated by gonadotrophin surge attenuating factor

    Oestradiol plus progesterone treatment increases serum leptin concentrations in normal women

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    BACKGROUND: Previous studies have alluded to a role for both oestradiol and progesterone in the secretion of leptin from fat cells in the human, although direct evidence has yet to be obtained. The study aim was to assess serum leptin concentrations in normally cycling women receiving exogenous oestradiol and progesterone. METHODS: Normally cycling women were investigated in an untreated spontaneous cycle (control, n = 10), a cycle treated with oestradiol (oestradiol cycle, n = 10) and a cycle treated with oestradiol plus progesterone (oestradiol + progesterone cycle, n = 6). Oestradiol was given to the women through skin patches on cycle days 2, 3 and 4, and progesterone intravaginally on cycle days 3, 4 and 5. Serum concentrations of leptin, oestradiol, progesterone, FSH and LH were measured in daily blood samples. RESULTS: During the treatment, serum oestradiol and progesterone concentrations increased significantly. In the oestradiol cycles, leptin concentrations were not affected by treatment and did not differ from those in controls. In the oestradiol+progesterone cycles, leptin concentrations (mean +/- SEM) increased in all women from cycle day 3 (8.6 +/- 1.1 ng/ml) to days 5 (12.2 +/- 1.8 ng/ml, P < 0.01) and 6 (11.9 +/- 2.0, P < 0.05), and were at these points significantly higher than in the control cycles (P < 0.05). The mean percentage increase from day 3 to the peak concentration on days 5 or 6 was 62.6 +/- 6.8%. Leptin concentrations returned to the pretreatment value on day 7, together with the concentrations of oestradiol and progesterone. In the oestradiol+progesterone cycles, leptin concentrations correlated significantly with oestradiol and progesterone concentrations, but not with FSH and LH concentrations. CONCLUSIONS: These results show, for the first time, that leptin secretion can be stimulated in women by the administration of oestradiol plus progesterone. This may explain the increased concentrations of leptin during the luteal phase of the normal menstrual cycle

    Leptin concentrations in the follicular phase of spontaneous cycles and cycles superovulated with follicle stimulating hormone

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    It has been reported that oestradiol may play a role in the production of leptin from adipocytes, To investigate this relationship further, nine normally ovulating women were studied during two menstrual cycles, i.e. an untreated spontaneous cycle and a cycle treated with follicle stimulating hormone (FSH) from cycle day 2 until the day of human chorionic gonadotrophin (HCG) injection, Serum leptin values on cycle day 2 did not differ significantly between the spontaneous and the FSH cycles. In the spontaneous cycles, leptin values declined gradually and significantly up to day 7 and then increased progressively up to the day of luteinizing hormone (LH) surge onset, at which point they achieved the highest values, In the FSH cycles, serum leptin values increased gradually and significantly up to day 6, remaining stable thereafter, and were in the midfollicular phase significantly higher than in the spontaneous cycles. Significant positive correlations were found between mean values of leptin and mean values of oestradiol during the second half of the follicular phase in the spontaneous cycles and during the first half in the FSH cycles, A significant negative correlation was found between these two parameters in the spontaneous cycles during the first half of the follicular phase. Serum leptin levels were significantly higher in the midluteal than in the follicular phase in both cycles. These results demonstrate for the first time significant changes in leptin values during the follicular phase of the human menstrual cycle and a significant increase during superovulation induction with FSH. It is suggested that oestradiol may be involved in the regulation of leptin production in women

    Relation between leptin and cortisol values in umbilical vessels at normal vaginal delivery

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    To study the role of various hormones in the control of fetal leptin secretion during labour, 33 pregnant women with normal singleton term pregnancy were recruited. At the time of spontaneous vaginal delivery, a venous blood sample was taken from the women together with a venous and an arterial cord blood sample. In all blood samples, leptin, cortisol, prolactin and progesterone were measured. Serum leptin and cortisol values were significantly higher, while those of prolactin and progesterone were significantly lower in the mother than in the two umbilical vessels (p < 0.01). Cortisol levels were significantly higher in the umbilical artery than in the umbilical vein (p < 0.01). Serum leptin values in the umbilical artery and vein correlated significantly with the corresponding values of cortisol (r = 0.523 and r = 0.580 respectively, p < 0.01), but not with those of prolactin and progesterone. A weak but significant correlation was found between leptin values in the two umbilical vessels and birth weight (r = 0.385 and r = 0.401 respectively, p < 0.05). In multiple regression analysis, cortisol values but not birth weight was the most important determinant of leptin values. Birth weight, however, correlated significantly with placental weight (r = 0.776, p < 0.001). These results demonstrate for the first time that leptin concentrations in the umbilical vessels at normal vaginal delivery correlate significantly with cortisol values, thus providing evidence that cortisol mediates a labour stimulating effect on fetal leptin secretion. It is suggested that cord blood leptin values at delivery are not a good predictor of neonatal weight

    Changes in gonadotrophin response to gonadotrophin releasing hormone in normal women following bilateral ovariectomy

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    OBJECTIVE Pituitary responsiveness to GnRH varies throughout the normal menstrual cycle, We have investigated whether there are differences in the ovarian mechanisms which regulate gonadotrophin secretion between the follicular and the luteal phase of the cycle. DESIGN Normally ovulating women were studied during the first week following hysterectomy plus bilateral ovariectomy performed either in the mid-to late follicular phase (follicle size 16mm) or in the early to midluteal phase (5 days post LH peak). The response of LH to a single dose of 10 mu g GnRH was investigated 2 hours before the operation and every 12 hours after the operation until postoperative day 4 and every 24 hours until day 8., PATIENTS Fourteen normally cycling premenopausal women with normal FSH (<10 IU/I). Seven women were ovariectomized in the follicular and 7 in the luteal phase, MEASUREMENTS Pituitary response to GnRH was calculated as the net increase in FSH (Delta FSH) and LH (Delta LH) at 30 minutes above the basal value, RESULTS Basal levers of FSH and LH before the operation were significantly lower in the luteal than the follicular phase (P < 0.05), while those of oestradiol (E2) were similar, Also, similar were Delta LH and Delta FSH values. Serum progesterone and immunoreactive inhibin (Ir-inhibin) concentrations before the operation were higher in the luteal than the follicular phase (P < 0.05). Following the operation, serum E2, progesterone and Ir-inhibin values declined dramatically, while basal FSH and LH as well as Delta FSH values showed a gradual and significant increase, The percentage increase in FSH and LH values(mean +/- SEM) on day 8 after the operation was similar in the follicular (453 +/- 99% and 118 +/- 35% respectively) and the luteal phase (480 +/- 71% and 192 +/- 45% respectively). In contrast to Delta FSH, Delta LH values after a temporal increase 12 hours from the operation, remained stable in the follicular phase and declined significantly in the luteal phase up to day 4., CONCLUSIONS Basalgonadotrophin secretion during the normal menstrual cycle is predominantly under a negative ovarian effect, It is suggested that in contrast to FSH, the secretion of LH in response to GnRH is controlled by different ovarian mechanisms during the two phases of the menstrual cycle

    Changes in pituitary response to gonadotropin releasing hormone following bilateral ovariectomy in women treated with follicle-stimulating hormone

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    Superovulation induction in women attenuates the pituitary response to gonadotropin-releasing hormone (GnRH). The aim of this study was to assess the duration of the suppressing activity of the ovaries on the pituitary. Eighteen normally ovulating women received treatment with follicle-stimulating hormone (FSH, 225 IU/day) on cycle days 2, 3 and 4. On cycle day 4, six women underwent hysterectomy plus bilateral ovariectomy (group ), another six women underwent hysterectomy without ovariectomy (group B) and the remaining six women underwent no operation (group C). The women of group C were also investigated during a preceding untreated spontaneous cycle (group D). The response of luteinizing hormone (LH) to an intravenous injection of 10 μg GnRH was investigated on cycle days 2, 3, 4 (2 and 12 h after clamping of the infundibulopelvic and/or round ligaments), 5, 6, and 7 in all four groups. The response of LH to GnRH at 30 min (ΔLH) was significantly attenuated as early as 12 h from the onset of FSH treatment (groups A, B and C), while estradiol and inhibin concentrations started to increase later (group C). In group C (no operation), the attenuation of ΔLH values continued throughout the study period, while in groups A and B the initial attenuation was followed by a marked increase in ΔLH values within 2 h from the operation. The increase in group A was twice the value in group B. Following this, ΔLH values in group B were attenuated again within the next 24 h, while in group A the remained for the rest of the postoperative period significantly higher than in group B. In conclusion, it was found that factor that mediates the suppressing effect of superovulated ovaries on the pituitary has a short-lasting (< 2 h) attenuating activity in the circulation
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