893 resultados para Stimulating Hormone


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OBJECTIVES: Proteomics approaches to cardiovascular biology and disease hold the promise of identifying specific proteins and peptides or modification thereof to assist in the identification of novel biomarkers. METHOD: By using surface-enhanced laser desorption and ionization time of flight mass spectroscopy (SELDI-TOF-MS) serum peptide and protein patterns were detected enabling to discriminate between postmenopausal women with and without hormone replacement therapy (HRT). RESULTS: Serum of 13 HRT and 27 control subjects was analyzed and 42 peptides and proteins could be tentatively identified based on their molecular weight and binding characteristics on the chip surface. By using decision tree-based Biomarker Patternstrade mark Software classification and regression analysis a discriminatory function was developed allowing to distinguish between HRT women and controls correctly and, thus, yielding a sensitivity of 100% and a specificity of 100%. The results show that peptide and protein patterns have the potential to deliver novel biomarkers as well as pinpointing targets for improved treatment. The biomarkers obtained represent a promising tool to discriminate between HRT users and non-users. CONCLUSION: According to a tentative identification of the markers by their molecular weight and binding characteristics, most of them appear to be part of the inflammation induced acute-phase response

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Suppression of cyclic activity in cattle is often desired in alpine farming and for feedlot cattle not intended for breeding. A cattle-specific anti-GnRH vaccination (Bopriva, Zoetis Australia Ltd., West Ryde, Australia) is approved for use in heifers and bulls in New Zealand, Australia, Mexico, Brazil, Argentina, Turkey, and Peru. Eleven healthy, cyclic Swiss Fleckvieh cows were included in the study and vaccinated twice with Bopriva 4wk apart. Injection site, rectal body temperature, and heart and respiratory rates were recorded before and 3d following each vaccination. Blood samples were taken weekly for progesterone and estrogen analysis and to determine GnRH antibody titer. Ovaries were examined weekly, using ultrasound to count the number of follicles and identify the presence of a corpus luteum. Thirty weeks after the first vaccination, the cows were subjected to a controlled internal drug-releasing device-based Select-Synch treatment. The GnRH antibody titers increased after the second vaccination and peaked 2wk later. Estrogen levels were not influenced by vaccination, and progesterone level decreased in 7 of 11 cows up to 3wk after the second vaccination and remained low for 10 to 15wk following the second vaccination. The number of class I follicles (diameter ≤5mm) was not influenced by vaccination, whereas the number of class II follicles (diameter 6-9mm) decreased between 7 and 16wk after the first vaccination. Class III follicles (diameter >9mm) were totally absent during this period in most cows. The median period until recurrence of class III follicles was 78d from the day of the second vaccination (95% confidence interval: 60-92d). After vaccination, all cows showed swelling and pain at the injection site, and these reactions subsided within 2wk. Body temperature and heart and respiratory rates increased after the first and second vaccinations and returned to normal values within 2d of each vaccination. The cows in our study were not observed to display estrus behavior until 30wk after the first vaccination. Therefore, a Select-Synch protocol was initiated at that time. Ten cows became pregnant after the first insemination (the remaining cow was reinseminated once until confirmed pregnancy). Bopriva induced a reliable and reversible suppression of reproductive cyclicity for more than 2mo. The best practical predictor for the length of the anestrus period was the absence of class III follicles.

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Current practice in Switzerland for the mobilization of autologous stem cells in patients with myeloma is combining vinorelbine chemotherapy and granulocyte-colony stimulating factor (G-CSF) cytokine stimulation. We prospectively investigated adding intravenous plerixafor to the vinorelbine/G-CSF combination (VGP), and compared it with vinorelbine/plerixafor (VP) and G-CSF/plerixafor (GP) combinations. In a final cohort (VP-late), plerixafor was given on the first day of CD34 + cells increasing to > 15 000/mL peripheral blood. Four consecutive cohorts of 10 patients with myeloma were studied. We observed that intravenously administered plerixafor can be safely combined with vinorelbine/G-CSF. VGP was superior in mobilizing peripheral stem and progenitor cells compared to the three double combinations (VP, GP and VP-late), and GP mobilized better than VP. Our data indicate that the triple combination of VGP is an efficient strategy to collect autologous CD34 + cells, with G-CSF contributing predominantly in this concept. Plerixafor can be safely added to G-CSF and/or vinorelbine chemotherapy.

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Butyrate is a short-chain fatty acid (SCFA) closely related to the ketone body ß-hydroxybutyrate (BHB), which is considered to be the major energy substrate during prolonged exercise or starvation. During fasting, serum growth hormone (GH) rises concomitantly with the accumulation of BHB and butyrate. Interactions between GH, ketone bodies and SCFA during the metabolic adaptation to fasting have been poorly investigated to date. In this study, we examined the effect of butyrate, an endogenous agonist for the two G-protein-coupled receptors (GPCR), GPR41 and 43, on non-stimulated and GH-releasing hormone (GHRH)-stimulated hGH secretion. Furthermore, we investigated the potential role of GPR41 and 43 on the generation of butyrate-induced intracellular Ca2+ signal and its ultimate impact on hGH secretion. To study this, wt-hGH was transfected into a rat pituitary tumour cell line stably expressing the human GHRH receptor. Treatment with butyrate promoted hGH synthesis and improved basal and GHRH-induced hGH-secretion. By acting through GPR41 and 43, butyrate enhanced intracellular free cytosolic Ca2+. Gene-specific silencing of these receptors led to a partial inhibition of the butyrate-induced intracellular Ca2+ rise resulting in a decrease of hGH secretion. This study suggests that butyrate is a metabolic intermediary, which contributes to the secretion and, therefore, to the metabolic actions of GH during fasting.

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BACKGROUND Aggregation of growth hormone (GH) required for its proper storage in granules is facilitated by zinc (Zn(2+)) transported by specific zinc transporters in and out of the regulated secretory pathway. Slc30a5 (ZnT5) was reported to have the highest gene expression among all zinc transporters in primary mouse pituitary cells while ZnT5-null mice presented with abnormal bone development and impaired growth compared to wild-type counterparts. METHODS In vitro studies performed in GH3 cells, a rat pituitary cell line that endogenously produces rat GH (rGH), included analysis of: cytoplasmic Zn(2+) pool changes after altering rSlc30a5 expression (luciferase assay), rZnT5 association with different compartments of the regulated secretory pathway (confocal microscopy), and the rGH secretion after rSlc30a5 knock-down (Western blot). RESULTS Confocal microscopy demonstrated high co-localization of rZnT5 with ER and Golgi (early secretory pathway) while siRNA-mediated knock-down of rSlc30a5 gene expression led to a significant reduction in rGH secretion. Furthermore, altered expression of rSlc30a5 (knock-down/overexpression) evoked changes in the cytoplasmic Zn(2+) pool indicating its important role in mediating Zn(2+) influx into intracellular compartments of the regulated secretory pathway. CONCLUSION Taken together, these results suggest that ZnT5 might play an important role in regulated GH secretion that is much greater than previously anticipated.

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BACKGROUND Current evidence on myelopoietic growth factors is difficult to overview for the practicing haematologist/oncologist. International guidelines are sometimes conflicting, exclude certain patient groups, or cannot directly be applied to the German health system. This guideline by the Infectious Diseases Working Party (AGIHO) of the German Society of Haematology and Medical Oncology (DGHO) gives evidence-based recommendations for the use of G-CSF, pegylated G-CSF, and biosimilars to prevent infectious complications in cancer patients undergoing chemotherapy, including those with haematological malignancies. METHODS We systematically searched and evaluated current evidence. An expert panel discussed the results and recommendations. We then compared our recommendations to current international guidelines. RESULTS We summarised the data from eligible studies in evidence tables, developed recommendations for different entities and risk groups. CONCLUSION Comprehensive literature search and expert panel consensus confirmed many key recommendations given by international guidelines. Evidence for growth factors during acute myeloid leukaemia induction chemotherapy and pegfilgrastim use in haematological malignancies was rated lower compared with other guidelines.

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Endokrine Disruptoren sind Umweltsubstanzen, die in das Hormonsystem von Organismen eingreifen, und dadurch zu schädlichen Wirkungen führen. Sie entfalten ihre Wirkung entweder, indem sie den Hormonstoffwechsel stören oder indem sie die Wirkung von Hormonen imitieren. Eine wichtige Gruppe von endokrinen Disruptoren in der aquatischen Umwelt sind Stoffe, die an Östrogenrezeptoren binden und dadurch wie das weibliche Sexualhormon, 17β-Östradiol wirken. Zu den Umweltöstrogenen gehören sowohl synthetische Chemikalien wie auch natürliche Substanzen. Sowohl Laborversuche wie Felduntersuchungen an Fischen haben gezeigt, dass bereits sehr niedrige Konzentrationen von Umweltöstrogenen in Gewässern in der Lage sind, Störungen des Hormonsystems auszulösen. Environmental estrogens Endocrine disrupters are environmental substances which interfere with the hormone system of organisms and thereby induce adverse effects. They exert their biological activity either by disrupting hormone metabolism or by imitating the biological action of the endogenous hormones. In the aquatic environment, an important group of endocrine disrupters is represented by the estrogen-active compounds, which mimic the female sex hormone, 17β-estradiol. Both laboratory experiments and field studies on fishes have demonstrated that already very low concentrations of environmental estrogens are able to induce disturbances in the hormone system and hormone-regulated processes of fishes.

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Despite increasing life expectancy, the age of onset of natural menopause has not significantly changed in recent decades. Thus, women spend about one-third of their lives in an estrogen-deficient state if untreated. There is a need for appropriate treatment of acute symptoms and prevention of the sequelae of chronic estrogen deficiency. International guidelines call for the use of the lowest effective hormone dosage for vasomotor symptom relief, the major indication for menopausal hormone therapy (MHT). In 2011, an oral continuous combined ultra-low-dose MHT was approved in Switzerland. This publication was elaborated by eight national menopause specialists and intends to review the advantages and disadvantages of ultra-low-dose MHT after the first years of its general use in Switzerland. It concludes that, for many women, ultra-low-dose MHT may be sufficient to decrease vasomotor symptoms, but not necessarily to guarantee fracture prevention.

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PURPOSE Vascular disease is the leading cause of death in women. One-third of acute events affect women below age 60, when the prevalence of menopausal symptoms is high. This raises the question if hormone replacement therapy (HRT) may be an appropriate treatment for individual women although vascular disease is generally considered a contraindication. METHODS Selective literature search was used for this study. RESULTS In healthy women, HRT increases risks for venous thromboembolism and ischemic stroke, but for cardiovascular disease apparently only beyond 10 years after menopause or 60 years of age. Limited data in women with cardio or cerebrovascular disease have not demonstrated an increased risk for a vascular recurrent event, but for the first year after initiation. In HRT users affected by a cardiovascular event continuation of HRT has not been found to be associated with adverse outcome. Low dose estradiol--preferentially as transdermal patches, if necessary combined with metabolically neutral progestins--appears to convey lower risk. CONCLUSIONS Safety data on HRT in survivors of cardiovascular events or ischemic stroke are limited, but exceptionally increased risk appears to be excluded. If off-label use of HRT is considered to be initiated or continued in women with cardio- or cerebrovascular disease, extensive counseling on the pros and cons of HRT is mandatory.

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This study aimed at evaluating a peak oxygen uptake test as a simple diagnostic tool to assess growth-hormone deficiency (GHD) in adults. Based on the findings of multiple growth hormone (GH) samplings after the exercise, a single GH sample taken 15 min postexercise revealed high accuracy in the diagnosis of GHD in the present study. A standardized peak oxygen uptake test may, therefore, provide an accurate alternative to more invasive tests of GHD.

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Slugs and snails are important herbivores in many ecosystems. They differ from other herbivores by their characteristic mucus trail. As the mucus is secreted at the interface between the plants and the herbivores, its chemical composition may play an essential role in plant responses to slug and snail attack. Based on our current knowledge about host-manipulation strategies employed by pathogens and insects, we hypothesized that mollusks may excrete phytohormone-like substances into their mucus. We therefore screened locomotion mucus from thirteen molluscan herbivores for the presence of the plant defense hormones jasmonic acid (JA), salicylic acid (SA) and abscisic acid (ABA). We found that the locomotion mucus of one slug, Deroceras reticulatum, contained significant amounts of SA, a plant hormone that is known to induce resistance to pathogens and to suppress plant immunity against herbivores. None of the other slugs and snails contained SA or any other hormone in their locomotion mucus. When the mucus of D. reticulatum was applied to wounded leaves of A. thaliana, the promotor of the SA-responsive gene pathogenesis related 1 (PR1) was activated, demonstrating the potential of the mucus to regulate plant defenses. We discuss the potential ecological, agricultural and medical implications of this finding.