Clinical applications of the sustained-release dexamethasone implant for treatment of macular edema

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Rocío Herrero-Vanrell, Jose Augusto Cardillo

2011-02-01

Full Text Available Rocío Herrero-Vanrell1, Jose Augusto Cardillo2, Baruch D Kuppermann31Department of Pharmacy and Pharmaceutical Technology, School of Pharmacy, Complutense University, Madrid, Spain; 2Hospital de Olhos de Araraquara, Araraquara, São Paulo, Brazil; 3Gavin Herbert Eye Institute, University of California, Irvine, CA, USAAbstract: Macular edema is one of the leading causes of vision loss among patients with retinal vein occlusion, diabetic retinopathy, and posterior chamber inflammatory disease. However, the treatment of macular edema is considerably limited by the difficulty in delivering effective doses of therapeutic agents into the vitreous cavity. In recent years, the development of a sustained-release dexamethasone intravitreal implant (Ozurdex® has enabled more controlled drug release at a stable rate over a long period of time, with a potentially lower rate of adverse events. Clinical studies indicate that this dexamethasone implant is a promising new treatment option for patients with persistent macular edema resulting from retinal vein occlusion, diabetic retinopathy, and uveitis or Irvine-Gass syndrome.Keywords: diabetic retinopathy, macular edema, Ozurdex®, posterior-segment inflammatory disease, retinal vein occlusion, sustained-release dexamethasone implant

Retrospective analysis of an oral combination of dexamethasone, uracil plus tegafur and cyclophosphamide for hormone-refractory prostate cancer.

Science.gov (United States)

Hatano, Koji; Nonomura, Norio; Nishimura, Kazuo; Kawashima, Atsunari; Mukai, Masatoshi; Nagahara, Akira; Nakai, Yasutomo; Nakayama, Masashi; Takayama, Hitoshi; Tsujimura, Akira; Okuyama, Akihiko

2011-02-01

To evaluate the clinical utility of an oral combination of dexamethasone, uracil plus tegafur and cyclophosphamide as a treatment for patients with hormone-refractory prostate cancer. Fifty-seven patients with hormone-refractory prostate cancer were treated with an oral administration of dexamethasone (1.0 mg/day), uracil plus tegafur (400 mg/day) and cyclophosphamide (100 mg/day). The median patient age was 71 years. Sixteen patients had symptomatic bone metastasis, 31 had asymptomatic bone metastasis and 8 showed lymph node metastasis. Eight patients presented with only biochemical progression as evaluated by serum prostate-specific antigen levels. Thirty-six (63%) of 57 patients demonstrated a ≥50% decline in serum prostate-specific antigen levels. The median time to prostate-specific antigen progression was 7.2 months. In patients with a prostate-specific antigen decline of ≥50%, the median time to progression was 13.3 months. With respect to pre-treatment markers, the duration of response to initial hormonal treatment was associated with the time to prostate-specific antigen progression. In 11 of 16 (69%) patients who complained of bone pain, the pain improved and became stable in 5 of those patients (31%). Most adverse events were mild and only three (5%) patients showed neutropenia of Grade 3 or higher. The combination of dexamethasone, uracil plus tegafur and cyclophosphamide is an effective and well tolerated regimen for hormone-refractory prostate cancer. To evaluate the survival benefits, further randomized studies are required.

Influence of Dexamethasone on Some Reproductive Hormones and Uterine Progesterone Receptor Localization in Pregnant Yankasa Sheep in Semiarid Zones of Nigeria

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Dauda Yahi

2017-01-01

Full Text Available Dexamethasone is widely used in both veterinary and human medical practices. However, it seems to cause some deleterious effects on pregnancy probably by causing changes in the reproductive hormone levels and their corresponding receptor concentrations. This study investigated the effects of dexamethasone on these parameters. Twenty healthy adult Yankasa sheep comprising 18 ewes and 2 rams were used for this study. Pregnancies were achieved by natural mating after estrus synchronization. Dexamethasone was administered at 0.25 mg/kg body weight on days 1, 3, and 5 during first trimester; days 51, 53, and 55 during second trimester; and days 101, 103, and 105 during the third trimester. Blood samples were collected biweekly for hormonal assay. Uterine biopsies were harvested through caesarean section for immunohistochemical analysis. Results showed that dexamethasone significantly (p0.05 effect on estrogen, while progesterone receptors (PR were upregulated. The abortion could probably be due to decreased progesterone concentrations as a consequence of the adverse effects on placenta. The PR upregulation may be a compensatory mechanism to increase progesterone sensitivity. It was concluded that dexamethasone should not be used in advanced pregnancy in Yankasa sheep.

Influence of Dexamethasone on Some Reproductive Hormones and Uterine Progesterone Receptor Localization in Pregnant Yankasa Sheep in Semiarid Zones of Nigeria.

Science.gov (United States)

Yahi, Dauda; Ojo, Nicholas Adetayo; Mshelia, Gideon Dauda

2017-01-01

Dexamethasone is widely used in both veterinary and human medical practices. However, it seems to cause some deleterious effects on pregnancy probably by causing changes in the reproductive hormone levels and their corresponding receptor concentrations. This study investigated the effects of dexamethasone on these parameters. Twenty healthy adult Yankasa sheep comprising 18 ewes and 2 rams were used for this study. Pregnancies were achieved by natural mating after estrus synchronization. Dexamethasone was administered at 0.25 mg/kg body weight on days 1, 3, and 5 during first trimester; days 51, 53, and 55 during second trimester; and days 101, 103, and 105 during the third trimester. Blood samples were collected biweekly for hormonal assay. Uterine biopsies were harvested through caesarean section for immunohistochemical analysis. Results showed that dexamethasone significantly ( p progesterone concentrations and caused abortion in Yankasa sheep but had no significant ( p > 0.05) effect on estrogen, while progesterone receptors (PR) were upregulated. The abortion could probably be due to decreased progesterone concentrations as a consequence of the adverse effects on placenta. The PR upregulation may be a compensatory mechanism to increase progesterone sensitivity. It was concluded that dexamethasone should not be used in advanced pregnancy in Yankasa sheep.

Biodegradable hyaluronic acid hydrogels to control release of dexamethasone through aqueous Diels-Alder chemistry for adipose tissue engineering.

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Fan, Ming; Ma, Ye; Zhang, Ziwei; Mao, Jiahui; Tan, Huaping; Hu, Xiaohong

2015-11-01

A robust synthetic strategy of biopolymer-based hydrogels has been developed where hyaluronic acid derivatives reacted through aqueous Diels-Alder chemistry without the involvement of chemical catalysts, allowing for control and sustain release of dexamethasone. To conjugate the hydrogel, furan and maleimide functionalized hyaluronic acid were synthesized, respectively, as well as furan functionalized dexamethasone, for the covalent immobilization. Chemical structure, gelation time, morphologies, swelling kinetics, weight loss, compressive modulus and dexamethasone release of the hydrogel system in PBS at 37°C were studied. The results demonstrated that the aqueous Diels-Alder chemistry provides an extremely selective reaction and proceeds with high efficiency for hydrogel conjugation and covalent immobilization of dexamethasone. Cell culture results showed that the dexamethasone immobilized hydrogel was noncytotoxic and preserved proliferation of entrapped human adipose-derived stem cells. This synthetic approach uniquely allows for the direct fabrication of biologically functionalized gel scaffolds with ideal structures for adipose tissue engineering, which provides a competitive alternative to conventional conjugation techniques such as copper mediated click chemistry. Copyright © 2015. Published by Elsevier B.V.

Efficacy of dexamethasone suppression test during the diagnosis of primary pigmented nodular adrenocortical disease in Chinese adrenocorticotropic hormone-independent Cushing syndrome.

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Chen, Shi; Li, Ran; Lu, Lin; Duan, Lian; Zhang, Xuebin; Tong, Anli; Pan, Hui; Zhu, Huijuan; Lu, Zhaolin

2018-01-01

To evaluate the cut-off value of the ratio of 24 h urinary free cortisol (24 h UFC) levels post-dexamethasone to prior-dexamethasone in dexamethasone suppression test (DST) during the diagnosis of primary pigmented nodular adrenocortical disease in Chinese adrenocorticotropic hormone-independent Cushing syndrome. Retrospective study. The patients diagnosed with primary pigmented nodular adrenocortical disease (PPNAD, n = 25), bilateral macronodular adrenal hyperplasia (BMAH, n = 27), and adrenocortical adenoma (ADA, n = 84) were admitted to the Peking Union Medical College Hospital from 2001 to 2016. Serum cortisol, adrenocorticotropic hormone (ACTH), and 24 h UFC were measured before and after low-dose dexamethasone suppression test (LDDST) and high-dose dexamethasone suppression test (HDDST). After LDDST and HDDST, 24 h UFC elevated in patients with PPNAD (paired t-test, P = 0.007 and P = 0.001), while it remained unchanged in the BMAH group (paired t-test, P = 0.471 and P = 0.414) and decreased in the ADA group (paired t-test, P = 0.002 and P = 0.004). The 24 h UFC level after LDDST was higher in PPNAD and BMAH as compared to ADA (P < 0.017), while no significant difference was observed between PPNAD and BMAH. After HDDST, 24 h UFC was higher in patients with PPNAD as compared to that of ADA and BMAH (P < 0.017). The cut-off value of 24 h UFC (Post-L-Dex)/(Pre-L-Dex) was 1.16 with 64.0% sensitivity and 77.9% specificity, and the cut-off value of 24 h UFC (Post-H-Dex)/(Pre-H-Dex) was 1.08 with 84.0% sensitivity and 75.6% specificity. The ratio of post-dexamethasone to prior-dexamethasone had a unique advantage in distinguishing PPNAD from BMAH and ADA.

Influence of Dexamethasone on Some Reproductive Hormones and Uterine Progesterone Receptor Localization in Pregnant Yankasa Sheep in Semiarid Zones of Nigeria

OpenAIRE

Yahi, Dauda; Ojo, Nicholas Adetayo; Mshelia, Gideon Dauda

2017-01-01

Dexamethasone is widely used in both veterinary and human medical practices. However, it seems to cause some deleterious effects on pregnancy probably by causing changes in the reproductive hormone levels and their corresponding receptor concentrations. This study investigated the effects of dexamethasone on these parameters. Twenty healthy adult Yankasa sheep comprising 18 ewes and 2 rams were used for this study. Pregnancies were achieved by natural mating after estrus synchronization. Dexa...

Differential response to dexamethasone on the TXB2 release in guinea-pig alveolar macrophages induced by zymosan and cytokines

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M. E. Salgueiro

1997-01-01

Full Text Available Glucocorticosteroids reduce the production of inflammatory mediators but this effect may depend on the stimulus. We have compared the time course of the effect of dexamethasone on the thromboxane B2 (TXB2 release induced by cytokine stimulation and zymosan in guinea-pig alveolar macrophages. Interleukin-1β (IL-1β, tumour necrosis factor-α (TNF-α and opsonized zymosan (OZ, all stimulate TXB2 release. High concentrations of dexamethasone (1–10 μM inhibit the TXB2 production induced by both cytokines and OZ, but the time course of this response is different. Four hours of incubation with dexamethasone reduce the basal TXB2 release and that induced by IL-1β and TNF-α, but do not modify the TXB2 release induced by OZ. However, this stimulus was reduced after 24 h incubation. Our results suggest that the antiinflammatory activity of glucocorticosteroids shows some dependence on stimulus and, therefore, may have more than one mechanism involved.

Estradiol potentiation of gonadotropin-releasing hormone responsiveness in the anterior pituitary is mediated by an increase in gonadotropin-releasing hormone receptors

International Nuclear Information System (INIS)

Menon, M.; Peegel, H.; Katta, V.

1985-01-01

In order to investigate the mechanism by which 17 beta-estradiol potentiates the action of gonadotropin-releasing hormone on the anterior pituitary in vitro, cultured pituitary cells from immature female rats were used as the model system. Cultures exposed to estradiol at concentrations ranging from 10(-10) to 10(-6) mol/L exhibited a significant augmentation of luteinizing hormone release in response to a 4-hour gonadotropin-releasing hormone (10 mumol/L) challenge at a dose of 10(-9) mol/L compared to that of control cultures. The estradiol augmentation of luteinizing hormone release was also dependent on the duration of estradiol exposure. When these cultures were incubated with tritium-labeled L-leucine, an increase in incorporation of radiolabeled amino acid into total proteins greater than that in controls was observed. A parallel stimulatory effect of estradiol on iodine 125-labeled D-Ala6 gonadotropin-releasing hormone binding was observed. Cultures incubated with estradiol at different concentrations and various lengths of time showed a significant increase in gonadotropin-releasing hormone binding capacity and this increase was abrogated by cycloheximide. Analysis of the binding data showed that the increase in gonadotropin-releasing hormone binding activity was due to a change in the number of gonadotropin-releasing hormone binding sites rather than a change in the affinity. These results suggest that (1) estradiol treatment increases the number of pituitary receptors for gonadotropin-releasing hormone, (2) the augmentary effect of estradiol on luteinizing hormone release at the pituitary level might be mediated, at least in part, by the increase in the number of binding sites of gonadotropin-releasing hormone, and (3) new protein synthesis may be involved in estradiol-mediated gonadotropin-releasing hormone receptor induction

Growth hormone (GH)-releasing activity of chicken GH-releasing hormone (GHRH) in chickens.

Science.gov (United States)

Harvey, S; Gineste, C; Gaylinn, B D

2014-08-01

Two peptides with sequence similarities to growth hormone releasing hormone (GHRH) have been identified by analysis of the chicken genome. One of these peptides, chicken (c) GHRH-LP (like peptide) was previously found to poorly bind to chicken pituitary membranes or to cloned and expressed chicken GHRH receptors and had little, if any, growth hormone (GH)-releasing activity in vivo or in vitro. In contrast, a second more recently discovered peptide, cGHRH, does bind to cloned and expressed cGHRH receptors and increases cAMP activity in transfected cells. The possibility that this peptide may have in vivo GH-releasing activity was therefore assessed. The intravenous (i.v.) administration of cGHRH to immature chickens, at doses of 3-100 μg/kg, significantly increased circulating GH concentrations within 10 min of injection and the plasma GH levels remained elevated for at least 30 min after the injection of maximally effective doses. The plasma GH responses to cGHRH were comparable with those induced by human (h) or porcine (p) GHRH preparations and to that induced by thyrotropin releasing hormone (TRH). In marked contrast, the i.v. injection of cGHRH-LP had no significant effect on circulating GH concentrations in immature chicks. GH release was also increased from slaughterhouse chicken pituitary glands perifused for 5 min with cGHRH at doses of 0.1 μg/ml or 1.0 μg/ml, comparable with GH responses to hGHRH1-44. In contrast, the perifusion of chicken pituitary glands with cGHRH-LP had no significant effect on GH release. In summary, these results demonstrate that cGHRH has GH-releasing activity in chickens and support the possibility that it is the endogenous ligand of the cGHRH receptor. Copyright © 2014 Elsevier Inc. All rights reserved.

Exaggerated gonadotropin response to luteinizing hormone-releasing hormone in amenorrheic runners.

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Yahiro, J; Glass, A R; Fears, W B; Ferguson, E W; Vigersky, R A

1987-03-01

Most studies of exercise-induced amenorrhea have compared amenorrheic athletes (usually runners) with sedentary control subjects. Such comparisons will identify hormonal changes that develop as a result of exercise training but cannot determine which of these changes play a role in causing amenorrhea. To obviate this problem, we assessed reproductive hormone status in a group of five amenorrheic runners and compared them to a group of six eumenorrheic runners matched for body fatness, training intensity, and exercise performance. Compared to the eumenorrheic runners, the amenorrheic runners had lower serum estradiol concentrations, similar basal serum luteinizing hormone and follicle-stimulating hormone concentrations, and exaggerated responses of serum gonadotropins after administration of luteinizing hormone-releasing hormone (100 micrograms intravenous bolus). Serum prolactin levels, both basally and after thyrotropin-releasing hormone administration (500 micrograms intravenous bolus) or treadmill exercise, was similar in the two groups, as were serum thyroid function tests (including thyrotropin response to thyrotropin-releasing hormone). Changes in serum cortisol levels after short-term treadmill exercise were similar in both groups, and serum testosterone levels increased after exercise only in the eumenorrheic group. In neither group did such exercise change serum luteinizing hormone, follicle-stimulating hormone, or thyrotropin levels. We concluded that exercise-induced amenorrhea is not solely related to the development of increased prolactin output after exercise training. The exaggerated gonadotropin response to luteinizing hormone-releasing hormone seen in amenorrheic runners in comparison with matched eumenorrheic runners is consistent with a hypothalamic etiology for the menstrual dysfunction, analogous to that previously described in "stress-induced" or "psychogenic" amenorrhea.

Effects of hyperthyroidism and hypothyroidism on rat growth hormone release induced by thyrotropin-releasing hormone.

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Chihara, K; Kato, Y; Ohgo, S; Iwasaki, Y; Maeda, K

1976-06-01

The effect of synthetic thyrotropin-releasing hormone (TRH) on the release of growth hormone (GH) and thyroid-stimulating hormone (TSH) was investigated in euthyroid, hypothyroid, and hyperthyroid rats under urethane anesthesia. In euthyroid control rats, intravenous injection of TRH (200 ng/100 g BW) resulted in a significant increase in both plasma GH and TSH. In rats made hypothyroid by treatment with propylthiouracil or by thyroidectomy, basal GH and TSH levels were significantly elevated with exaggerated responses to TRH. In contrast, plasma GH and TSH responses to TRH were both significantly inhibited in rats made hyperthyroid by L-thyroxine (T4) treatment. These results suggest that altered thyroid status influences GH release as well as TSH secretion induced by TRH in rats.

New trends in combined use of gonadotropin-releasing hormone antagonists with gonadotropins or pulsatile gonadotropin-releasing hormone in ovulation induction and assisted reproductive technologies.

Science.gov (United States)

Gordon, K; Danforth, D R; Williams, R F; Hodgen, G D

1992-10-01

The use of gonadotropin-releasing hormone agonists as adjunctive therapy with gonadotropins for ovulation induction in in vitro fertilization and other assisted reproductive technologies has become common clinical practice. With the recent advent of potent gonadotropin-releasing hormone antagonists free from the marked histamine-release effects that stymied earlier compounds, an attractive alternative method may be available. We have established the feasibility of combining gonadotropin-releasing hormone antagonist-induced inhibition of endogenous gonadotropins with exogenous gonadotropin therapy for ovulation induction in a nonhuman primate model. Here, the principal benefits to be gained from using the gonadotropin-releasing hormone antagonist rather than the gonadotropin-releasing hormone agonist are the immediate inhibition of pituitary gonadotropin secretion without the "flare effect," which brings greater safety and convenience for patients and the medical team and saves time and money. We have also recently demonstrated the feasibility of combining gonadotropin-releasing hormone antagonist with pulsatile gonadotropin-releasing hormone therapy for the controlled restoration of gonadotropin secretion and gonadal steroidogenesis culminating in apparently normal (singleton) ovulatory cycles. This is feasible only with gonadotropin-releasing hormone antagonists because, unlike gonadotropin-releasing hormone agonists, they achieve control of the pituitary-ovarian axis without down regulation of the gonadotropin-releasing hormone receptor system. This capacity to override gonadotropin-releasing hormone antagonist-induced suppression of pituitary-ovarian function may allow new treatment modalities to be employed for women who suffer from chronic hyperandrogenemia with polycystic ovarian disease.

Loss of cannabinoid receptor CB1 induces preterm birth.

Directory of Open Access Journals (Sweden)

Haibin Wang

2008-10-01

Full Text Available Preterm birth accounting approximate 10% of pregnancies in women is a tremendous social, clinical and economic burden. However, its underlying causes remain largely unknown. Emerging evidence suggests that endocannabinoid signaling via cannabinoid receptor CB1 play critical roles in multiple early pregnancy events in both animals and humans. Since our previous studies demonstrated that loss of CB1 defers the normal implantation window in mice, we surmised that CB1 deficiency would influence parturition events.Exploiting mouse models with targeted deletion of Cnr1, Cnr2 and Ptgs1 encoding CB1, CB2 and cyclooxygenase-1, respectively, we examined consequences of CB1 or CB2 silencing on the onset of parturition. We observed that genetic or pharmacological inactivation of CB1, but not CB2, induced preterm labor in mice. Radioimmunoassay analysis of circulating levels of ovarian steroid hormones revealed that premature birth resulting from CB1 inactivation is correlated with altered progesterone/estrogen ratios prior to parturition. More strikingly, the phenotypic defects of prolonged pregnancy length and parturition failure in mice missing Ptgs1 were corrected by introducing CB1 deficiency into Ptgs1 null mice. In addition, loss of CB1 resulted in aberrant secretions of corticotrophin-releasing hormone and corticosterone during late gestation. The pathophysiological significance of this altered corticotrophin-releasing hormone-driven endocrine activity in the absence of CB1 was evident from our subsequent findings that a selective corticotrophin-releasing hormone antagonist was able to restore the normal parturition timing in Cnr1 deficient mice. In contrast, wild-type females receiving excessive levels of corticosterone induced preterm birth.CB1 deficiency altering normal progesterone and estrogen levels induces preterm birth in mice. This defect is independent of prostaglandins produced by cyclooxygenase-1. Moreover, CB1 inactivation resulted in

Antimüllerian hormone in gonadotropin releasing-hormone antagonist cycles

DEFF Research Database (Denmark)

Arce, Joan-Carles; La Marca, Antonio; Mirner Klein, Bjarke

2013-01-01

To assess the relationships between serum antimüllerian hormone (AMH) and ovarian response and treatment outcomes in good-prognosis patients undergoing controlled ovarian stimulation using a gonadotropin-releasing hormone (GnRH) antagonist protocol....

Additive manufacturing of scaffolds with dexamethasone controlled release for enhanced bone regeneration.

Science.gov (United States)

Costa, Pedro F; Puga, Ana M; Díaz-Gomez, Luis; Concheiro, Angel; Busch, Dirk H; Alvarez-Lorenzo, Carmen

2015-12-30

The adoption of additive manufacturing in tissue engineering and regenerative medicine (TERM) strategies greatly relies on the development of novel 3D printable materials with advanced properties. In this work we have developed a material for bone TERM applications with tunable bioerosion rate and dexamethasone release profile which can be further employed in fused deposition modelling (the most common and accessible 3D printing technology in the market). The developed material consisted of a blend of poly-ϵ-caprolactone (PCL) and poloxamine (Tetronic®) and was processed into a ready-to-use filament form by means of a simplified melt-based methodology, therefore eliminating the utilization of solvents. 3D scaffolds composed of various blend formulations were additively manufactured and analyzed revealing blend ratio-specific degradation rates and dexamethasone release profiles. Furthermore, in vitro culture studies revealed a similar blend ratio-specific trend concerning the osteoinductive activity of the fabricated scaffolds when these were seeded and cultured with human mesenchymal stem cells. The developed material enables to specifically address different regenerative requirements found in various tissue defects. The versatility of such strategy is further increased by the ability of additive manufacturing to accurately fabricate implants matching any given defect geometry. Copyright © 2015 Elsevier B.V. All rights reserved.

Corticotropin-releasing hormone and pituitary-adrenal hormones in pregnancies complicated by chronic hypertension.

Science.gov (United States)

Warren, W B; Gurewitsch, E D; Goland, R S

1995-02-01

We hypothesized that maternal plasma corticotropin-releasing hormone levels are elevated in chronic hypertension and that elevations modulate maternal and fetal pituitary-adrenal function. Venous blood samples and 24-hour urine specimens were obtained in normal and hypertensive pregnancies at 21 to 40 weeks of gestation. Corticotropin-releasing hormone, corticotropin, cortisol, dehydroepiandrosterone sulfate, and total estriol levels were measured by radioimmunoassay. Mean hormone levels were compared by unpaired t test or two-way analysis of variance. Plasma corticotropin-releasing hormone levels were elevated early in hypertensive pregnancies but did not increase after 36 weeks. Levels of pituitary and adrenal hormones were not different in normal and hypertensive women. However, maternal plasma estriol levels were lower in hypertensive pregnancies compared with normal pregnancies. Fetal 16-hydroxy dehydroepiandrosterone sulfate, the major precursor to placental estriol production, has been reported to be lower than normal in hypertensive pregnancies, possibly explaining the decreased plasma estriol levels reported here. Early stimulation of placental corticotropin-releasing hormone production or secretion may be related to accelerated maturation of placental endocrine function in pregnancies complicated by chronic hypertension.

Cocaine- and amphetamine-regulated transcript is present in hypothalamic neuroendocrine neurones and is released to the hypothalamic-pituitary portal circuit

DEFF Research Database (Denmark)

Larsen, P J; Seier, V; Fink-Jensen, A

2003-01-01

Cocaine- and amphetamine-regulated transcript (CART) is present in a number of hypothalamic nuclei. Besides actions in circuits regulating feeding behaviour and stress responses, the hypothalamic functions of CART are largely unknown. We report that CART immunoreactivity is present in hypothalami......, supraoptic, paraventricular (PVN) and periventricular nuclei of the hypothalamus. In the PVN, CART-positive neuroendocrine neurones were found in all of cytoarchitectonically identified nuclei. In the periventricular nucleus, approximately one-third of somatostatin cells were also CART......-immunoreactive. In the medial parvicellular subnucleus of the PVN, CART and FG coexisted with thyrotrophin-releasing hormone, whereas very few of the corticotrophin-releasing hormone containing cells were CART-immunoreactive. In the arcuate nucleus, CART was extensively colocalized with pro...

Interleukin 1α inhibits prostaglandin E2 release to suppress pulsatile release of luteinizing hormone but not follicle-stimulating hormone

International Nuclear Information System (INIS)

Rettori, V.; McCann, S.M.; Gimeno, M.F.; Karara, A.; Gonzalez, M.C.

1991-01-01

Interleukin 1α (IL-1α), a powerful endogenous pyrogen released from monocytes and macrophages by bacterial endotoxin, stimulates corticotropin, prolactin, and somatotropin release and inhibits thyrotropin release by hypothalamic action. The authors injected recombinant human IL-1α into the third cerebral ventricle, to study its effect on the pulsatile release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in conscious, freely moving, ovariectomized rats. Intraventricular injection of 0.25 pmol of IL-1α caused an almost immediate reduction of plasma LH concentration. To determine the mechanism of the suppression of LH release, mediobasal hypothalamic fragments were incubated in vitro with IL-1α (10 pM) and the release of LH-releasing hormone (LHRH) and prostaglandin E 2 into the medium was measured by RIA in the presence or absence of nonrepinephrine. 1α reduced basal LHRH release and blocked LHRH release induced by nonrepinephrine. In conclusion, IL-1α suppresses LH but not FSH release by an almost complete cessation of pulsatile release of LH in the castrated rat. The mechanism of this effect appears to be by inhibition of prostaglandin E 2 -mediated release of LHRH

The effects of corticotrophin-releasing factor and two antagonists on breathing movements in fetal sheep.

Science.gov (United States)

Bennet, L; Johnston, B M; Vale, W W; Gluckman, P D

1990-01-01

1. The respiratory effects of corticotrophin-releasing factor (CRF) and the CRF antagonists alpha-helical CRF 9-41 (alpha hCRF) and [DPhe 12, Nle 21-38] rCRF (12-41) (DPhe CRF) have been studied in unanaesthetized fetal lambs of 125-140 days gestation. 2. CRF when given as a 10 micrograms bolus followed by a 5 micrograms h-1 infusion into a lateral cerebral ventricle caused prolonged continuous fetal breathing movements which were stimulated in both amplitude and frequency but which did not persist during hypoxia. 3. Lower doses of CRF (20 ng bolus followed by 10 ng h-1) increased the amplitude but not the frequency of fetal breathing movements which did not become continuous. 4. At higher doses (20 micrograms bolus followed by 10-15 micrograms h-1) CRF induced cerebral convulsions which were also associated with fetal breathing movements of increased amplitude and frequency. 5. The CRF antagonists alpha hCRF and DPhe CRF both inhibited fetal breathing movements and induced a prolonged apnoea which was resistant to the stimulatory effects of 5-6% hypercapnia. 6. We conclude that CRF stimulates breathing movements in the fetal lamb. The finding that administration of the CRF antagonists alone cause apnoea suggests that CRF may have a tonic role in the regulation of fetal breathing movements. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:2348387

Hypothalamic regulation of thyroid-stimulating hormone and prolactin release : the role of thyrotrophin-releasing hormone

NARCIS (Netherlands)

G.A.C. van Haasteren (Goedele)

1995-01-01

textabstractThyrotrophin-releasing-hormone (TRH), a tripeptide, is produced by hypothalamic neurons and transported along their axons to the median eminence (ME). From there it is released at nerve terminals into hypophyseal portal blood. It is then transported to the anterior pituitary gland where

Multilayer poly(3,4-ethylenedioxythiophene)-dexamethasone and poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate-carbon nanotubes coatings on glassy carbon microelectrode arrays for controlled drug release.

Science.gov (United States)

Castagnola, Elisa; Carli, Stefano; Vomero, Maria; Scarpellini, Alice; Prato, Mirko; Goshi, Noah; Fadiga, Luciano; Kassegne, Sam; Ricci, Davide

2017-07-13

The authors present an electrochemically controlled, drug releasing neural interface composed of a glassy carbon (GC) microelectrode array combined with a multilayer poly(3,4-ethylenedioxythiophene) (PEDOT) coating. The system integrates the high stability of the GC electrode substrate, ideal for electrical stimulation and electrochemical detection of neurotransmitters, with the on-demand drug-releasing capabilities of PEDOT-dexamethasone compound, through a mechanically stable interlayer of PEDOT-polystyrene sulfonate (PSS)-carbon nanotubes (CNT). The authors demonstrate that such interlayer improves both the mechanical and electrochemical properties of the neural interface, when compared with a single PEDOT-dexamethasone coating. Moreover, the multilayer coating is able to withstand 10 × 10 6 biphasic pulses and delamination test with negligible change to the impedance spectra. Cross-section scanning electron microscopy images support that the PEDOT-PSS-CNT interlayer significantly improves the adhesion between the GC substrate and PEDOT-dexamethasone coating, showing no discontinuities between the three well-interconnected layers. Furthermore, the multilayer coating has superior electrochemical properties, in terms of impedance and charge transfer capabilities as compared to a single layer of either PEDOT coating or the GC substrate alone. The authors verified the drug releasing capabilities of the PEDOT-dexamethasone layer when integrated into the multilayer interface through repeated stimulation protocols in vitro, and found a pharmacologically relevant release of dexamethasone.

Growth Hormone-Releasing Hormone in Diabetes

Directory of Open Access Journals (Sweden)

Leonid Evsey Fridlyand

2016-10-01

Full Text Available Growth hormone-releasing hormone (GHRH is produced by the hypothalamus and stimulates growth hormone synthesis and release in the anterior pituitary gland. In addition GHRH is an important regulator of cellular functions in many cells and organs. Expression of GHRH G-Protein Coupled Receptor (GHRHR has been demonstrated in different peripheral tissues and cell types including pancreatic islets. Among the peripheral activities, recent studies demonstrate a novel ability of GHRH analogs to increase and preserve insulin secretion by beta-cells in isolated pancreatic islets, which makes them potentially useful for diabetes treatment. This review considers the role of GHRHR in the beta-cell and addresses the unique engineered GHRH agonists and antagonists for treatment of Type 2 diabetes mellitus. We discuss the similarity of signaling pathways activated by GHRHR in pituitary somatotrophs and in pancreatic beta-cells and possible ways as to how the GHRHR pathway can interact with glucose and other secretagogues to stimulate insulin secretion. We also consider the hypothesis that novel GHRHR agonists can improve glucose metabolism in Type 2 diabetes by preserving the function and survival of pancreatic beta-cells. Wound healing and cardioprotective action with new GHRH agonists suggesting that they may prove useful in ameliorating certain diabetic complications. These findings highlight the future potential therapeutic effectiveness of modulators of GHRHR activity for the development of new therapeutic approaches in diabetes and its complications.

A regulator of G Protein signaling, RGS3, inhibits gonadotropin-releasing hormone (GnRH-stimulated luteinizing hormone (LH secretion

Directory of Open Access Journals (Sweden)

Musgrove Lois C

2001-11-01

Full Text Available Abstract Background Luteinizing hormone secreted by the anterior pituitary gland regulates gonadal function. Luteinizing hormone secretion is regulated both by alterations in gonadotrope responsiveness to hypothalamic gonadotropin releasing hormone and by alterations in gonadotropin releasing hormone secretion. The mechanisms that determine gonadotrope responsiveness are unknown but may involve regulators of G protein signaling (RGSs. These proteins act by antagonizing or abbreviating interaction of Gα proteins with effectors such as phospholipase Cβ. Previously, we reported that gonadotropin releasing hormone-stimulated second messenger inositol trisphosphate production was inhibited when RGS3 and gonadotropin releasing hormone receptor cDNAs were co-transfected into the COS cell line. Here, we present evidence for RGS3 inhibition of gonadotropin releasing hormone-induced luteinizing hormone secretion from cultured rat pituitary cells. Results A truncated version of RGS3 (RGS3T = RGS3 314–519 inhibited gonadotropin releasing hormone-stimulated inositol trisphosphate production more potently than did RSG3 in gonadotropin releasing hormone receptor-bearing COS cells. An RSG3/glutathione-S-transferase fusion protein bound more 35S-Gqα than any other member of the G protein family tested. Adenoviral-mediated RGS3 gene transfer in pituitary gonadotropes inhibited gonadotropin releasing hormone-stimulated luteinizing hormone secretion in a dose-related fashion. Adeno-RGS3 also inhibited gonadotropin releasing hormone stimulated 3H-inositol phosphate accumulation, consistent with a molecular site of action at the Gqα protein. Conclusions RGS3 inhibits gonadotropin releasing hormone-stimulated second messenger production (inositol trisphosphate as well as luteinizing hormone secretion from rat pituitary gonadotropes apparently by binding and suppressing the transduction properties of Gqα protein function. A version of RGS3 that is amino

Cerebrospinal fluid levels of corticotropin-releasing hormone in women with functional hypothalamic amenorrhea.

Science.gov (United States)

Berga, S L; Loucks-Daniels, T L; Adler, L J; Chrousos, G P; Cameron, J L; Matthews, K A; Marcus, M D

2000-04-01

Women with functional hypothalamic amenorrhea are anovulatory because of reduced gonadotropin-releasing hormone drive. Several studies have documented hypercortisolemia, which suggests that functional hypothalamic amenorrhea is stress-induced. Further, with recovery (resumption of ovulation), cortisol decreased and gonadotropin-releasing hormone drive increased. Corticotropin-releasing hormone can increase cortisol and decrease gonadotropin-releasing hormone. To determine its role in functional hypothalamic amenorrhea, we measured corticotropin-releasing hormone in cerebrospinal fluid along with arginine vasopressin, another potent adrenocorticotropic hormone secretagog, and beta-endorphin, which is released by corticotropin-releasing hormone and can inhibit gonadotropin-releasing hormone. Corticotropin-releasing hormone, vasopressin, and beta-endorphin levels were measured in cerebrospinal fluid from 14 women with eumenorrhea and 15 women with functional hypothalamic amenorrhea. Levels of corticotropin-releasing hormone in cerebrospinal fluid and of vasopressin were comparable and beta-endorphin levels were lower in women with functional hypothalamic amenorrhea. In women with established functional hypothalamic amenorrhea, increased cortisol and reduced gonadotropin-releasing hormone are not sustained by elevated cerebrospinal-fluid corticotropin-releasing hormone, vasopressin, or beta-endorphin. These data do not exclude a role for these factors in the initiation of functional hypothalamic amenorrhea.

Alterations in neuropeptides in aging and disease. Pathophysiology and potential for clinical intervention.

Science.gov (United States)

Leake, A; Ferrier, I N

1993-01-01

Marked specific and selective changes in the levels of some neuropeptides in age-related diseases, such as senile dementia of the Alzheimer (SDAT) or Lewy body (SDLT) types, Parkinson's disease, Huntington's disease and major depressive disorder, versus normal aging have been noted. However, the levels of most neuropeptides are normal. The only 2 peptides consistently altered in SDAT are somatostatin and corticotrophin-releasing hormone both of which are reduced. In Huntington's disease, the level of substance P in the basal ganglia is reduced suggesting a preferential vulnerability of spiny neurones in this disease. In Parkinson's disease, substance P is attenuated in the basal ganglia while somatostatin is reduced in the neocortex. These and other results suggest that substance P deficits are related to movement disorders while somatostatin deficits are related to cognitive impairment. SDLT is a type of dementia with features common to both SDAT and Parkinson's disease, although the changes in neuropeptides suggest that neurochemically the disease is more closely related to SDAT. In major depressive disorder, the level of corticotrophin-releasing hormone is reduced while there is a reciprocal increase in corticotrophin-releasing hormone receptors suggesting that the neurones remain functional. Potential clinical intervention has been limited by problems such as poor penetration of agents into the brain and the short half-lives of neuropeptide agonists and antagonists. However, some currently available agents may act, at least in part, through modulation of neuropeptide pathways, e.g. carbamazepine and alprazolam both modulate the corticotrophin-releasing hormone system in animals, and both have clinically proven antidepressant activity.

Radioimmunological and clinical studies with luteinizing hormone releasing hormone (LRH)

International Nuclear Information System (INIS)

Dahlen, H.G.

1986-01-01

Radioimmunoassay for Luteinizing Hormone Releasing Hormone (LRH) has been established, tested and applied. Optimal conditions for the performance with regards to incubation time, incubation temperature, concentration of antiserum and radiolabelled LRH have been established. The specificity of the LRH immunoassay was investigated. Problems with direct measurement of LRH in plasmas of radioimmunoassay are encountered. The LRH distribution in various tissues of the rat are investigated. By means of a system for continuous monitoring of LH and FSH in women the lowest effective dose of LRH causing a significant release of LH and FSH could be established. (Auth.)

Effect of poly(lactide-co-glycolide) molecular weight on the release of dexamethasone sodium phosphate from microparticles.

Science.gov (United States)

Jaraswekin, Saowanee; Prakongpan, Sompol; Bodmeier, Roland

2007-03-01

The objective of this study was to investigate the effect of poly(lactide-co-glycolide) (PLGA) molecular weight (Resomer RG 502H, RG 503H, and RG 504H) on the release behavior of dexamethasone sodium phosphate-loaded microparticles. The microparticles were prepared by three modifications of the solvent evaporation method (O/W-cosolvent, O/W-dispersion, and W/O/W-methods). The encapsulation efficiency of microparticles prepared by the cosolvent- and W/O/W-methods increased from approximately 50% to >90% upon addition of NaCl to the external aqueous phase, while the dispersion method resulted in lower encapsulation efficiencies. The release of dexamethasone sodium phosphate from PLGA microparticles (>50 microm) was biphasic. The initial burst release correlated well with the porosity of the microparticles, both of which increased with increasing polymer molecular weight (RG 504H > 503H > 502H). The burst was also dependent on the method of preparation and was in the order of dispersion method > WOW method > consolvent method. In contrast to the higher molecular weight PLGA microparticles, the release from RG 502H microparticles prepared by cosolvent method was not affected by volume of organic solvent (1.5-3.0 ml) and drug loading (4-13%). An initial burst of approximately 10% followed by a 5-week sustained release phase was obtained. Microparticles with a size <50 microm released in a triphasic manner; an initial burst was followed by a slow release phase and then by a second burst.

In vitro effect of Δ9-tetrahydrocannabinol to stimulate somatostatin release and block that of luteinizing hormone-releasing hormone by suppression of the release of prostaglandin E2

International Nuclear Information System (INIS)

Rettori, V.; Aguila, M.C.; McCann, S.M.; Gimeno, M.F.; Franchi, A.M.

1990-01-01

Previous in vivo studies have shown that Δ 9 -tetrahydrocannabinol (THC), the principal active ingredient in marijuana, can suppress both luteinizing hormone (LH) and growth hormone (GH) secretion after its injection into the third ventricle of conscious male rats. The present studies were deigned to determine the mechanism of these effects. Various doses of THC were incubated with either stalk median eminence fragments (MEs) or mediobasal hypothalamic (MBH) fragments in vitro. Although THC (10 nM) did not alter basal release of LH-releasing hormone (LHRH) from MEs in vitro, it completely blocked the stimulatory action of dopamine or nonrepinephrine on LHRH release. The effective doses to block LHRH release were associated with a blockade of synthesis and release of prostaglandin E 2 (PGE 2 ) from MBH in vitro. In contrast to the suppressive effect of THC on LHRH release, somatostatin release from MEs was enhanced in a dose-related manner with a minimal effective dose of 1 nM. Since PGE 2 suppresses somatostatin release, this enhancement may also be related to the suppressive effect of THC on PGE 2 synthesis and release. The authors speculate that these actions are mediated by the recently discovered THC receptors in the tissue. The results indicate that the suppressive effect of THC on LH release is mediated by a blockade of LHRH release, whereas the suppressive effect of the compound on growth hormone release is mediated, at least in part, by a stimulation of somatostatin release

The interrelationships of thyroid and growth hormones: effect of growth hormone releasing hormone in hypo- and hyperthyroid male rats.

Science.gov (United States)

Root, A W; Shulman, D; Root, J; Diamond, F

1986-01-01

Growth hormone (GH) and the thyroid hormones interact in the hypothalamus, pituitary and peripheral tissues. Thyroid hormone exerts a permissive effect upon the anabolic and metabolic effects of GH, and increases pituitary synthesis of this protein hormone. GH depresses the secretion of thyrotropin and the thyroid hormones and increases the peripheral conversion of thyroxine to triiodothyronine. In the adult male rat experimental hypothyroidism produced by ingestion of propylthiouracil depresses the GH secretory response to GH-releasing hormone in vivo and in vitro, reflecting the lowered pituitary stores of GH in the hypothyroid state. Short term administration of large amounts of thyroxine with induction of the hyperthyroid state does not affect the in vivo GH secretory response to GH-releasing hormone in this animal.

Pituitary mammosomatotroph adenomas develop in old mice transgenic for growth hormone-releasing hormone

DEFF Research Database (Denmark)

Asa, S L; Kovacs, K; Stefaneanu, L

1990-01-01

It has been shown that mice transgenic for human growth hormone-releasing hormone (GRH) develop hyperplasia of pituitary somatotrophs and mammosomatotrophs, cells capable of producing both growth hormone and prolactin, by 8 months of age. We now report for the first time that old GRH-transgenic...

Algorithmic complexity of growth hormone release in humans

Energy Technology Data Exchange (ETDEWEB)

Prank, K.; Wagner, M.; Brabant, G. [Medical School Hannover (Germany)

1996-12-31

Most hormones are secreted in an pulsatile rather than in a constant manner. This temporal pattern of pulsatile hormone release plays an important role in the regulation of cellular function and structure. In healthy humans growth hormone (GH) secretion is characterized by distinct pulses whereas patients bearing a GH producing tumor accompanied with excessive secretion (acromegaly) exhibit a highly irregular pattern of GH release. It has been hypothesized that this highly disorderly pattern of GH release in acromegaly arises from random events in the GH-producing tumor under decreased normal control of GH secretion. Using a context-free grammar complexity measure (algorithmic complexity) in conjunction with random surrogate data sets we demonstrate that the temporal pattern of GH release in acromegaly is not significantly different from a variety of stochastic processes. In contrast, normal subjects clearly exhibit deterministic structure in their temporal patterns of GH secretion. Our results support the hypothesis that GH release in acromegaly is due to random events in the GH-producing tumorous cells which might become independent from hypothalamic regulation. 17 refs., 1 fig., 2 tabs.

Metabotropic glutamate receptor 2 and corticotrophin-releasing factor receptor-1 gene expression is differently regulated by BDNF in rat primary cortical neurons

DEFF Research Database (Denmark)

Jørgensen, Christinna V; Klein, Anders B; El-Sayed, Mona

2013-01-01

Brain-derived neurotrophic factor (BDNF) is important for neuronal survival and plasticity. Incorporation of matured receptor proteins is an integral part of synapse formation. However, whether BDNF increases synthesis and integration of receptors in functional synapses directly is unclear. We...... are particularly interested in the regulation of the 5-hydroxytryptamine receptor 2A (5-HT2A R). This receptor form a functional complex with the metabotropic glutamate receptor 2 (mGluR2) and is recruited to the cell membrane by the corticotrophin-releasing factor receptor 1 (CRF-R1). The effect of BDNF on gene...... expression for all these receptors, as well as a number of immediate-early genes, was pharmacologically characterized in primary neurons from rat frontal cortex. BDNF increased CRF-R1 mRNA levels up to fivefold, whereas mGluR2 mRNA levels were proportionally downregulated. No effect on 5-HT2A R mRNA was seen...

Endocrinologic and psychological effects of short-term dexamethasone in anorexia nervosa.

Science.gov (United States)

Gordon, C M; Emans, S J; DuRant, R H; Mantzoros, C; Grace, E; Harper, G P; Majzoub, J A

2000-09-01

Patients with anorexia nervosa (AN) have hyperactivity of their hypothalamic-pituitary-adrenal (HPA) axis, sometimes accompanied by elevations of cortisol. We examined whether the normal effects of short-term dexamethasone treatment upon HPA axis suppression and appetite stimulation are observed in these patients. Five young women with AN and ten healthy female controls received one week of high-dose oral dexamethasone (2 mg/m2/d) preceded and followed by hormonal evaluation of sensitivity to glucocorticoids and psychological assessments. No differences in hormone levels of the HPA axis were observed between the two groups and control groups at baseline, after dexamethasone suppression, or following ACTH stimulation testing. However, fasting insulin levels were significantly lower in the AN group, both before and after dexamethasone therapy and their serum leptin levels were also significantly lower. The AN group had significantly lower scores on the Anorexia Nervosa Subtest and the Beck Depression Inventory after dexamethasone compared to controls. On daily analog scales, AN patients had higher anxiety scores while on dexamethasone. Normal sensitivity to glucocorticoids was observed in all parameters examined except for mild abnormalities in pancreatic beta-cell function. These data suggest that AN may represent a state of partial glucocorticoid resistance, as in other states of restricted food intake. Furthermore, these pilot data, including the effects of dexamethasone upon psychological outlook in AN, suggest that glucocorticoids are not an effective therapy for these patients.

In vitro effect of. Delta. sup 9 -tetrahydrocannabinol to stimulate somatostatin release and block that of luteinizing hormone-releasing hormone by suppression of the release of prostaglandin E sub 2

Energy Technology Data Exchange (ETDEWEB)

Rettori, V.; Aguila, M.C.; McCann, S.M. (Univ. of Texas Southwestern Medical Center at Dallas (United States)); Gimeno, M.F.; Franchi, A.M. (Centro de Estudios Farmacologicos y de Principios Naturales, Buenos Aires (Argentina))

1990-12-01

Previous in vivo studies have shown that {Delta}{sup 9}-tetrahydrocannabinol (THC), the principal active ingredient in marijuana, can suppress both luteinizing hormone (LH) and growth hormone (GH) secretion after its injection into the third ventricle of conscious male rats. The present studies were deigned to determine the mechanism of these effects. Various doses of THC were incubated with either stalk median eminence fragments (MEs) or mediobasal hypothalamic (MBH) fragments in vitro. Although THC (10 nM) did not alter basal release of LH-releasing hormone (LHRH) from MEs in vitro, it completely blocked the stimulatory action of dopamine or nonrepinephrine on LHRH release. The effective doses to block LHRH release were associated with a blockade of synthesis and release of prostaglandin E{sub 2} (PGE{sub 2}) from MBH in vitro. In contrast to the suppressive effect of THC on LHRH release, somatostatin release from MEs was enhanced in a dose-related manner with a minimal effective dose of 1 nM. Since PGE{sub 2} suppresses somatostatin release, this enhancement may also be related to the suppressive effect of THC on PGE{sub 2} synthesis and release. The authors speculate that these actions are mediated by the recently discovered THC receptors in the tissue. The results indicate that the suppressive effect of THC on LH release is mediated by a blockade of LHRH release, whereas the suppressive effect of the compound on growth hormone release is mediated, at least in part, by a stimulation of somatostatin release.

The role of releasing hormones in the diagnosis of hypopituitarism ...

African Journals Online (AJOL)

Luteinising hormone-releasing factor and thyrotrophinreleasing factor were used in conjunction with the insulin tolerance test in 9 patients with known or suspected panhypopituitarism. It appears that growth hormone and luteinising hormone fail early in panhypopituitarism. Cortisol and thyroid-stimulating hormone ...

Corticotropin-releasing hormone: Mediator of vertebrate life stage transitions?

Science.gov (United States)

Watanabe, Yugo; Grommen, Sylvia V H; De Groef, Bert

2016-03-01

Hormones, particularly thyroid hormones and corticosteroids, play critical roles in vertebrate life stage transitions such as amphibian metamorphosis, hatching in precocial birds, and smoltification in salmonids. Since they synergistically regulate several metabolic and developmental processes that accompany vertebrate life stage transitions, the existence of extensive cross-communication between the adrenal/interrenal and thyroidal axes is not surprising. Synergies of corticosteroids and thyroid hormones are based on effects at the level of tissue hormone sensitivity and gene regulation. In addition, in representative nonmammalian vertebrates, corticotropin-releasing hormone (CRH) stimulates hypophyseal thyrotropin secretion, and thus functions as a common regulator of both the adrenal/interrenal and thyroidal axes to release corticosteroids and thyroid hormones. The dual function of CRH has been speculated to control or affect the timing of vertebrate life history transitions across taxa. After a brief overview of recent insights in the molecular mechanisms behind the synergic actions of thyroid hormones and corticosteroids during life stage transitions, this review examines the evidence for a possible role of CRH in controlling vertebrate life stage transitions. Copyright © 2016 Elsevier Inc. All rights reserved.

Preliminary studies of plasma growth hormone releasing activity during medical therapy of acromegaly

International Nuclear Information System (INIS)

Hagen, T.C.; Lawrence, A.M.; Kirsteins, L.

1978-01-01

The in vitro growth hormone releasing activity of plasma obtained from six acromegalic subjects was measured before and during therapy. In five subjects, plasmas were obtained before and during successful medical therapy with medroxyprogesterone acetate (MPA). The sixth subject was sampled before and after transphenoidal Sr 90 -induced hypopituitarism. All subjects had a decrement in fasting growth hormone levels with respective therapies (29-88%). The in vitro growth hormone released from Rhesus monkey anterior pituitaries was assessed after incubating one lateral half in control plasma (pre-therapy) and the contralateral pituitary half in plasma obtained during or after therapy. Studies with plasmas obtained from the five patients successfully treated with MPA showed a decrease in growth hormone releasing activity during therapy in all (18-57%). Plasma obtained after Sr 90 pituitary ablation in the sixth subject had 35% more growth hormone releasing activity than obtained before therapy. These results suggest that active acromegalics who respond to MPA with significantly lowered growth hormone levels may actually achieve this response because of a decrease in growth hormone releasing factor measured peripherally. The opposite response in one acromegalic subject, following Sr 90 pituitary ablation and hypopituitarism, suggests that growth hormone releasing factor secretion may increase when growth hormone levels are lowered by ablative therapy. (orig.) [de

Peptide YY, neuropeptide Y and corticotrophin-releasing factor modulate gastrointestinal motility and food intake during acute stress.

Science.gov (United States)

Forbes, Sarah C; Cox, Helen M

2014-11-01

Peripheral neuropeptide Y (NPY) provides protection against the endocrine, feeding and gastrointestinal (GI) responses to stress; however, it is not yet established how it interacts with corticotrophin-releasing factor (CRF) to mediate these effects. Peptide YY (PYY) also has significant roles in GI motility and food intake but little is known about its role in stress responses. Upper GI transit, fecal pellet output (FPO) and feeding responses, and the role of CRF1 receptors, during restraint or a novel environment stress, were ascertained in PYY-/-, NPY-/- and wild type (WT) mice, with CRF and the CRF1 antagonist, antalarmin, injected intraperitoneally. Upper GI transit and FPO were significantly increased in PYY-/- mice during restraint stress. Exogenous CRF increased defecation during placement in a novel environment in WT mice through CRF1 , while CRF1 blockade reduced defecation in WT and NPY-/- mice but had no effect in PYY-/- mice. In addition, CRF1 blockade had no effect on upper GI transit in WT mice, or on food intake in PYY-/- or NPY-/- mice, but it significantly increased food intake in WT mice. Endogenous NPY appears to inhibit the colonic motor response induced by CRF1 activation, unlike PYY, while both peptides are required for CRF1 modulation of feeding behavior during stress. Overall, these results provide new insights into the mechanism by which PYY and NPY affect stress responses. © 2014 John Wiley & Sons Ltd.

Synthesis and in vitro anti-cancer evaluation of luteinizing hormone-releasing hormone-conjugated peptide.

Science.gov (United States)

Deng, Xin; Qiu, Qianqian; Ma, Ke; Huang, Wenlong; Qian, Hai

2015-11-01

Luteinizing hormone-releasing hormone (LHRH) is a decapeptide hormone released from the hypothalamus and shows high affinity binding to the LHRH receptors. It is reported that several cancer cells also express LHRH receptors such as breast, ovarian, prostatic, bladder and others. In this study, we linked B1, an anti-cancer peptide, to LHRH and its analogs to improve the activity against cancer cells with LHRH receptor. Biological evaluation revealed that TB1, the peptide contains triptorelin sequence, present favorable anti-cancer activity as well as plasma stability. Further investigations disclosed that TB1 trigger apoptosis by activating the mitochondria-cytochrome c-caspase apoptotic pathway, it also exhibited the anti-migratory effect on cancer cells.

Overnight Levels of Luteinizing Hormone, Follicle-Stimulating Hormone and Growth Hormone before and during Gonadotropin-Releasing Hormone Analogue Treatment in Short Boys Born Small for Gestational Age

NARCIS (Netherlands)

van der Kaay, Danielle C. M.; de Jong, Frank H.; Rose, Susan R.; Odink, Roelof J. H.; Bakker-van Waarde, Willie M.; Sulkers, Eric J.; Hokken-Koelega, Anita C. S.

2009-01-01

Aims: To evaluate if 3 months of gonadotropin-releasing hormone analogue (GnRHa) treatment results in sufficient suppression of pubertal luteinizing hormone (LH) and follicle-stimulating hormone (FSH) profile patterns in short pubertal small for gestational age (SGA) boys. To compare growth hormone

Highly potent metallopeptide analogues of luteinizing hormone-releasing hormone

International Nuclear Information System (INIS)

Bajusz, S.; Janaky, T.; Csernus, V.J.; Bokser, L.; Fekete, M.; Srkalovic, G.; Redding, T.W.; Schally, A.V.

1989-01-01

Metal complexes related to the cytotoxic complexes cisplatin [cis-diamminedichloroplatinum(II)] and transbis(salicylaldoximato)copper(II) were incorporated into suitably modified luteinizing hormone-releasing hormone (LH-RH) analogues containing D-lysine at position 6. Some of the metallopeptides thus obtained proved to be highly active LH-RH agonists or antagonists. Most metallopeptide analogues of LH-RH showed high affinities for the membrane receptors of rat pituitary and human breast cancer cells. Some of these metallopeptides had cytotoxic activity against human breast cancer and prostate cancer and prostate cancer cell lines in vitro. Such cytostatic metallopeptides could be envisioned as targeted chemotherapeutic agents in cancers that contain receptors for LH-RH-like peptides

alpha-difluoromethylornithine modifies gonadotropin-releasing hormone release and follicle-stimulating hormone secretion in the immature female rat.

Science.gov (United States)

Thyssen, S M; Becú-Villalobos, D; Lacau-Mengido, I M; Libertun, C

1997-06-01

Polyamines play an essential role in tissue growth and differentiation, in body weight increment, in brain organization, and in the molecular mechanisms of hormonal action, intracellular signaling, and cell-to-cell communication. In a previous study, inhibition of their synthesis by alpha-difluoromethylornithine (DFMO), a specific and irreversible inhibitor of ornithine decarboxylase, during development in female rats, was followed by prolonged high follicle-stimulating hormone (FSH) serum level and a delayed puberty onset. Those changes were relatively independent of body mass and did not impair posterior fertility. The present work studies the mechanisms and site of action of polyamine participation in FSH secretion during development. DFMO was injected in female rats between Days 1 and 9 on alternate days. At 10 days of age, hypothalami from control and DFMO rats were perifused in vitro, and basal and potassium-induced gonadotropin-releasing hormone (GnRH) release were measured. The response to membrane depolarization was altered in DFMO hypothalami. Increased GnRH release in response to a low K+ concentration was evidenced. Adenohypophyses of the same treated prepubertal rats were perifused in vitro and the response to GnRH pulses was checked. In DFMO-treated rats, higher FSH release was observed, with no changes in LH or PRL secretion. Finally, pituitary GnRH receptor number in adenohypophyseal membranes from treated and control groups was quantified. A significant reduction in specific binding was evident in hypophyses from DFMO-treated rats when compared with binding in the control group. In summary, DFMO treatment in a critical developmental period in the female rat impacts the immature GnRH neuronal network and immature gonadotropes. A delay in maturation is evidenced by a higher sensitivity to secretagogs in both pituitary glands and hypothalamic explants. These events could explain the prolonged high FSH serum levels and delayed puberty onset seen in

Effects of Maternal Dexamethasone Exposure During Lactation on ...

African Journals Online (AJOL)

olayemitoyin

examined the effects of lactational dexamethasone exposure on metabolic imbalance and oxidative stress marker in the liver ... control. Basal Fasting Blood Sugar (FBS) was also significantly (p<0.001) higher in the Dex ... Exposure to stress and glucocorticoids hormone ..... Energy expenditure and energy intake during.

Highly potent metallopeptide analogues of luteinizing hormone-releasing hormone.

Science.gov (United States)

Bajusz, S; Janaky, T; Csernus, V J; Bokser, L; Fekete, M; Srkalovic, G; Redding, T W; Schally, A V

1989-08-01

Metal complexes related to the cytotoxic complexes cisplatin [cis-diamminedichloroplatinum(II)] and transbis(salicylaldoximato)copper(II) were incorporated into suitably modified luteinizing hormone-releasing hormone (LH-RH) analogues containing D-lysine at position 6. Some of the metallopeptides thus obtained proved to be highly active LH-RH agonists or antagonists. For instance, SB-40, a PtCl2-containing metallopeptide in which platinum is coordinated to an N epsilon-(DL-2,3-diaminopropionyl)-D-lysine residue [D-Lys(DL-A2pr] at position 6, showed 50 times higher LH-releasing potency than the native hormone. SB-95, [Ac-D-Nal(2)1,D-Phe(pCl)2, D-Pal(3)2, Arg5,D-Lys[DL-A2pr(Sal2Cu)]6,D-Ala10]LH-RH, where Nal(2) is 3-(2-naphthyl)alanine, Pal(3) is 3-(3-pyridyl)alanine, and copper(II) is coordinated to the salicylideneimino moieties resulting from condensation of salicylaldehyde with D-Lys(DL-A2pr)6, caused 100% inhibition of ovulation at a dose of 3 micrograms in rats. Most metallopeptide analogues of LH-RH showed high affinities for the membrane receptors of rat pituitary and human breast cancer cells. Some of these metallopeptides had cytotoxic activity against human breast cancer and prostate cancer cell lines in vitro (this will be the subject of a separate paper on cytotoxicity evaluation). Such cytostatic metallopeptides could be envisioned as targeted chemotherapeutic agents in cancers that contain receptors for LH-RH-like peptides.

Mathematical modeling of gonadotropin-releasing hormone signaling.

Science.gov (United States)

Pratap, Amitesh; Garner, Kathryn L; Voliotis, Margaritis; Tsaneva-Atanasova, Krasimira; McArdle, Craig A

2017-07-05

Gonadotropin-releasing hormone (GnRH) acts via G-protein coupled receptors on pituitary gonadotropes to control reproduction. These are G q -coupled receptors that mediate acute effects of GnRH on the exocytotic secretion of luteinizing hormone (LH) and follicle-stimulating hormone (FSH), as well as the chronic regulation of their synthesis. GnRH is secreted in short pulses and GnRH effects on its target cells are dependent upon the dynamics of these pulses. Here we overview GnRH receptors and their signaling network, placing emphasis on pulsatile signaling, and how mechanistic mathematical models and an information theoretic approach have helped further this field. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Development of New Gonadotropin-Releasing Hormone-Modified Dendrimer Platforms with Direct Antiproliferative and Gonadotropin Releasing Activity.

Science.gov (United States)

Varamini, Pegah; Rafiee, Amirreza; Giddam, Ashwini Kumar; Mansfeld, Friederike M; Steyn, Frederik; Toth, Istvan

2017-10-26

Gonadotropin-releasing hormone (GnRH) agonists (e.g., triptorelin) are used for androgen suppression therapy. They possess improved stability as compared to the natural GnRH, yet they suffer from a poor pharmacokinetic profile. To address this, we used a GnRH peptide-modified dendrimer platform with and without lipidation strategy. Dendrimers were synthesized on a polylysine core and bore either native GnRH (1, 2, and 5) or lipid-modified GnRH (3 and 4). Compound 3, which bore a lipidic moiety in a branched tetramer structure, showed approximately 10-fold higher permeability and metabolic stability and 39 times higher antitumor activity against hormone-resistant prostate cancer cells (DU145) relative to triptorelin. In gonadotropin-release experiments, dendrimer 3 was shown to be the most potent construct. Dendrimer 3 showed similar luteinizing hormone (LH)-release activity to triptorelin in mice. Our findings indicate that dendrimer 3 is a promising analog with higher potency for the treatment of hormone-resistant prostate cancer than the currently available GnRH agonists.

Radiation preparation of drug carriers based on poly(N-isopropylacrylamide) hydrogels, their loading capacities and controlled release rates for dexamethasone and tegafur

International Nuclear Information System (INIS)

Hoang Dang Sang; Nguyen Van Binh; Tran Bang Diep; Nguyen Thi Thom; Hoang Phuong Thao; Pham Duy Duong; Tran Minh Quynh

2015-01-01

Thermo-sensitive hydrogels have great potential in some applications. In order to use as the drug delivery systems, the hydrogels should be biocompatibility. New polymers with more biocompatibility and better biodegradability, and environmental friendly crosslinking agents would be necessary for the successful drug carriers. Poly (N-isopropylacrylamide-co-dimethylacrylamide) based hydrogels have been prepared from the admixture solutions of N-isopropylacrylamide (NIPA) and N,N’-dimethyl acrylamide (DMA) by radiation copolymerization and crosslinking at radiation dose of 20 kGy as reported in our previous study. Water swelling behaviour of the resulting hydrogels were much depended on their nature such as initial ratio of NIPA and DMA. The drug-loaded hydrogels were prepared by merging hydrogel in the solutions containing corresponding drugs. Loading capacity of the hydrogels were about 48.6 and 95.7 mg per g dried hydrogel for dexamethasone and tegafur. The release studies showed that the presence of ions in simulated body fluid and temperature of the solution much affecting to in vitro release behaviors of hydrogels for dexamethasone and tegafur. The release rates were fast for both drug models. The result also revealed that these drug carriers were biocompatibility without skin irritation, suggested the drug-loaded hydrogels may be used as controlled release drug delivery systems. (author)

Neonatal rearing conditions distinctly shape locus coeruleus neuronal activity, dendritic arborization, and sensitivity to corticotrophin-releasing factor

Science.gov (United States)

Swinny, Jerome D.; O'Farrell, Eimear; Bingham, Brian C.; Piel, David A.; Valentino, Rita J.; Beck, Sheryl G.

2010-01-01

Early life events influence vulnerability to psychiatric illness. This has been modelled in rats and it has been demonstrated that different durations of maternal separation shape adult endocrine and behavioural stress reactivity. One system through which maternal separation may act is the locus coeruleus (LC)–norepinephrine system that regulates emotional arousal. Here we demonstrate that different durations of maternal separation have distinct effects on LC physiology and dendritic morphology. Rat pups were separated from the dam for 15 min/d (HMS-15) or 180 min/d (HMS-180) from post-natal days 2–14. Others were either undisturbed (HMS-0) or were vendor-purchased controls. LC characteristics were compared at age 22–35 d using whole-cell recordings in vitro. Cells were filled with biocytin for morphological analysis. LC neurons of HMS-180 rats were tonically activated compared to HMS-15 and control rats, with firing rates that were 2-fold higher than these groups. Corticotrophin-releasing factor (CRF) application did not further activate LC neurons of HMS-180 rats but increased LC firing rate in HMS-0 and control rats. LC neurons of HMS-15 rats were resistant to excitation by CRF. Maternal separation also affected LC dendritic morphology. LC dendrites of HMS-15 rats exhibited less branching and decreased total dendritic length, an effect that could decrease the probability of contacting limbic afferents that terminate in the pericoerulear region. This effect may provide a structural basis for an attenuated magnitude of emotional arousal. Together, these results demonstrate long-term consequences of early life events on the LC–norepinephrine system that may shape adult behaviour. PMID:19653930

Cushing's disease and craniopharyngioma.

Science.gov (United States)

Ackland, F M; Stanhope, R; Preece, M A

1987-01-01

A 14-year old girl presented with growth failure and Cushing's disease. Histological examination confirmed a craniopharyngioma but failed to show that the tumour secreted adrenocorticotrophic hormone. We suggest that her Cushing's disease was caused by hypothalamic dysfunction associated with increased corticotrophin-releasing hormone secretion, secondary to the craniopharyngioma. Images Figure PMID:2823728

Growth hormone-releasing factor stimulates proliferation of somatotrophs in vitro

DEFF Research Database (Denmark)

Billestrup, Nils; Swanson, L W; Vale, W

1986-01-01

The mitogenic effect of the hypothalamic peptides growth hormone-releasing factor (GRF) and somatostatin on cultured growth hormone (GH)-producing cells (somatotrophs) was studied. Using autoradiographic detection of [3H]thymidine uptake and immunocytochemical identification of GH-producing cells...

The growth hormone (GH) response to GH-releasing peptide (His-DTrp-Ala-Trp-DPhe-Lys-NH2), GH-releasing hormone, and thyrotropin-releasing hormone in acromegaly.

Science.gov (United States)

Alster, D K; Bowers, C Y; Jaffe, C A; Ho, P J; Barkan, A L

1993-09-01

In patients with acromegaly, GH-producing pituitary tumors release GH in response to specific stimuli such as GH-releasing hormone (GHRH) and are also responsive to a variety of nonspecific stimuli, such as TRH or GnRH, and may exhibit paradoxical responses to glucose and dopamine. In healthy humans, the synthetic peptide GH-releasing peptide (GHRP) (His-D-Trp-Ala-Trp-D-Phe-Lys-NH2) releases GH by a putative mechanism of action that is independent of GHRH. How these tumors respond to GHRP is not well characterized. We studied the GH responses to GHRH, GHRP, and TRH stimulation in 11 patients with active acromegaly. The peak GH responses to GHRP and GHRH were not correlated (r = 0.57; P = 0.066). In contrast, the peak GH responses to GHRP and TRH were highly correlated (r = 0.95; P < 0.001). In conclusion, in patients with acromegaly, the GH response to GHRP is qualitatively normal and does not appear to depend on GHRH.

Paradoxical response to dexamethasone and spontaneous hypocortisolism in Cushing's disease

Science.gov (United States)

Lila, Anurag R; Sarathi, Vijaya; Bandgar, Tushar R; Shah, Nalini S

2013-01-01

Paradoxical response to dexamethasone and spontaneous development of hypocortisolism are rare features of Cushing's disease. We report a 13-year-old boy with Cushing's disease owing to a pituitary macroadenoma. On initial evaluation, he had partial suppression of serum cortisol by dexamethasone. He developed transient hypocortisolism after first adenomectomy, but the disease recurred after 1 year. Repeat evaluation showed recurrent hypercortisolism and paradoxical response to dexamethasone. He underwent second surgery and, postoperatively, hypercostisolism persisted even after 2 years of surgery. Repeat evaluations after 8 years of second surgery revealed persistent hypocortisolism despite residual tumour of same size and similar plasma adrenocorticotropic hormone (ACTH) levels. We have also shown that the paradoxical increase in serum cortisol was preceded by a paradoxical increase in ACTH. The paradoxical response persisted despite hypocortisolism. This patient with Cushing's disease had two very rare features: paradoxical response to dexamethasone and spontaneous development of hypocortisolism. PMID:23365169

Chronic stress-induced effects of corticosterone on brain: direct and indirect

NARCIS (Netherlands)

Dallman, M. F.; Akana, S. F.; Strack, A. M.; Scribner, K. S.; Pecoraro, N.; La Fleur, S. E.; Houshyar, H.; Gomez, F.

2004-01-01

Acutely, glucocorticoids act to inhibit stress-induced corticotrophin-releasing factor (CRF) and adrenocorticotrophic hormone (ACTH) secretion through their actions in brain and anterior pituitary (canonical feedback). With chronic stress, glucocorticoid feedback inhibition of ACTH secretion changes

Highly potent antagonists of luteinizing hormone-releasing hormone free of edematogenic effects.

Science.gov (United States)

Bajusz, S; Kovacs, M; Gazdag, M; Bokser, L; Karashima, T; Csernus, V J; Janaky, T; Guoth, J; Schally, A V

1988-03-01

To eliminate the undesirable edematogenic effect of the luteinizing hormone-releasing hormone (LH-RH) antagonists containing basic D amino acids at position 6, exemplified by [Ac-D-Phe(pCl)1,2,D-Trp3,D-Arg6,D-Ala10]LH-RH [Phe(pCl) indicates 4-chlorophenylalanine], analogs with D-ureidoalkyl amino acids such as D-citrulline (D-Cit) or D-homocitrulline (D-Hci) at position 6 were synthesized and tested in several systems in vitro and in vivo. HPLC analysis revealed that the overall hydrophobicity of the D-Cit/D-Hci6 analogs was similar to that of the basic D-Arg6 antagonists. In vitro, most of the analogs completely inhibited LH-RH-mediated luteinizing hormone release in perfused rat pituitary cell systems at an antagonist to LH-RH molar ratio of 5:1. In vivo, the most active peptides, [Ac-D-Nal(2)1,D-Phe(pCl)2,D-Trp3,D-Cit6,D-Ala10]LH-RH [Nal(2) indicates 3-(2-naphthyl)alanine] and its D-Hci6 analog, caused 100% inhibition of ovulation in cycling rats in doses of 3 micrograms and suppressed the luteinizing hormone level in ovariectomized female rats for 47 hr when administered at doses of 25 micrograms. Characteristically, these peptides did not exert any edematogenic effects even at 1.5 mg/kg. These properties of the D-Cit/D-Hci6 antagonists may make them useful clinically.

Response of arginine vasopressin-enhanced green fluorescent protein fusion gene in the hypothalamus of adjuvant-induced arthritic rats

Czech Academy of Sciences Publication Activity Database

Suzuki, H.; Onaka, T.; Kasai, M.; Kawasaki, M.; Ohnishi, H.; Otsubo, H.; Saito, T.; Hashimoto, H.; Yokoyama, T.; Fujihara, H.; Dayanithi, Govindan; Murphy, D.; Nakamura, T.; Ueta, Y.

2009-01-01

Roč. 21, č. 3 (2009), s. 183-190 ISSN 0953-8194 Institutional research plan: CEZ:AV0Z50390512 Keywords : arginine vasopressin * Corticotrophin-releasing hormone * GFP Subject RIV: FH - Neurology Impact factor: 3.700, year: 2009

Decapeptides as effective agonists from L-amino acids biologically equivalent to the luteinizing hormone-releasing hormone

International Nuclear Information System (INIS)

Folkers, K.; Bowers, C.Y.; Tang, P.L.; Kubota, M.

1986-01-01

Apparently, no agonist has been found that is comparable in potency to the luteinizing hormone-releasing hormone (LHRH) for release of LH and follicle-stimulating hormone (FSH) without substitutions with unnatural or D forms of natural amino acids. Of 139 known agonist analogs of LHRH, two were active in the range of 65%. The four LHRHs known to occur in nature involve a total of six amino acids (Tyr, His, Leu, Trp, Arg, Gln) in positions 5, 7, and 8. There are 16 possible peptides with these six amino acids in positions 5, 7, and 8, of which 4 are the known LHRHs, and 2 more were synthesized. The authors have synthesized the 10 new peptides and assayed 11 in vivo and in vitro, and they found not only 1 but a total of 5 that have activity equivalent to or greater than that of LHRH for the release of LH and/or FSH under at least one assay condition. These five are as follows: [His 5 ,Trp 7 ,Gln 8 ]LHRH; [His 5 ,Trp 7 ,Leu 8 ]LHRH; [His 5 ,Trp 7 ]LHRH; [Trp 7 ]LHRH; [His 5 ]LHRH. These structures are a basis for the design of antagonists without Arg 8 toward avoiding histamine release. Complete inhibition of LH and FSH release in vivo may be induced by joint use of Arg 8 and Gln 8 or Leu 8 antagonists. These potent agonists, related to LHRH, may be therapeutically useful in disorders of reproduction, the central nervous system, and for the control of hormone-dependent carcinomas. Radioreceptor assays and radioimmunoassays were utilized

Effect of growth hormone-releasing factor on growth hormone release in children with radiation-induced growth hormone deficiency

International Nuclear Information System (INIS)

Lustig, R.H.; Schriock, E.A.; Kaplan, S.L.; Grumbach, M.M.

1985-01-01

Five male children who received cranial irradiation for extrahypothalamic intracranial neoplasms or leukemia and subsequently developed severe growth hormone (GH) deficiency were challenged with synthetic growth hormone-releasing factor (GRF-44), in an attempt to distinguish hypothalamic from pituitary dysfunction as a cause of their GH deficiency, and to assess the readily releasable GH reserve in the pituitary. In response to a pulse of GRF-44 (5 micrograms/kg intravenously), mean peak GH levels rose to values higher than those evoked by the pharmacologic agents L-dopa or arginine (6.4 +/- 1.3 ng/mL v 1.5 +/- 0.4 ng/mL, P less than .05). The peak GH value occurred at a mean of 26.0 minutes after administration of GRF-44. These responses were similar to those obtained in children with severe GH deficiency due to other etiologies (peak GH 6.3 +/- 1.7 ng/mL, mean 28.0 minutes). In addition, there was a trend toward an inverse relationship between peak GH response to GRF-44 and the postirradiation interval. Prolactin and somatomedin-C levels did not change significantly after the administration of a single dose of GRF-44. The results of this study support the hypothesis that cranial irradiation in children can lead to hypothalamic GRF deficiency secondary to radiation injury of hypothalamic GRF-secreting neurons. This study also lends support to the potential therapeutic usefulness of GRF-44 or an analog for GH deficiency secondary to cranial irradiation

A role for central nervous growth hormone-releasing hormone signaling in the consolidation of declarative memories.

Directory of Open Access Journals (Sweden)

Manfred Hallschmid

Full Text Available Contributions of somatotropic hormonal activity to memory functions in humans, which are suggested by clinical observations, have not been systematically examined. With previous experiments precluding a direct effect of systemic growth hormone (GH on acute memory formation, we assessed the role of central nervous somatotropic signaling in declarative memory consolidation. We examined the effect of intranasally administered growth hormone releasing-hormone (GHRH; 600 µg that has direct access to the brain and suppresses endogenous GHRH via an ultra-short negative feedback loop. Twelve healthy young men learned word-pair associates at 2030 h and were administered GHRH and placebo, respectively, at 2100 h. Retrieval was tested after 11 hours of wakefulness. Compared to placebo, intranasal GHRH blunted GH release within 3 hours after substance administration and reduced the number of correctly recalled word-pairs by ∼12% (both P<0.05. The impairment of declarative memory consolidation was directly correlated to diminished GH concentrations (P<0.05. Procedural memory consolidation as examined by the parallel assessment of finger sequence tapping performance was not affected by GHRH administration. Our findings indicate that intranasal GHRH, by counteracting endogenous GHRH release, impairs hippocampal memory processing. They provide first evidence for a critical contribution of central nervous somatotropic activity to hippocampus-dependent memory consolidation.

Effects of growth hormone deficiency and recombinant growth hormone therapy on postprandial gallbladder motility and cholecystokinin release.

NARCIS (Netherlands)

Moschetta, A.; Twickler, M.; Rehfeld, J.F.; Ooteghem, N.A. van; Castro Cabezas, M.; Portincasa, P.; Berge-Henegouwen, G.P. van; Erpecum, K.J. van

2004-01-01

In addition to cholecystokinin, other hormones have been suggested to be involved in regulation of postprandial gallbladder contraction. We aimed to evaluate effects of growth hormone (GH) on gallbladder contractility and cholecystokinin release. Gallbladder and gastric emptying (by ultrasound) and

In vivo correlation between c-Fos expression and corticotroph stimulation by adrenocorticotrophic hormone secretagogues in rat anterior pituitary gland.

Science.gov (United States)

Takigami, Shu; Fujiwara, Ken; Kikuchi, Motoshi; Yashiro, Takashi

2008-03-01

In the anterior pituitary gland, c-Fos expression is evoked by various stimuli. However, whether c-Fos expression is directly related to the stimulation of anterior pituitary cells by hypothalamic secretagogues is unclear. To confirm whether the reception of hormone-releasing stimuli evokes c-Fos expression in anterior pituitary cells, we have examined c-Fos expression of anterior pituitary glands in rats administered with synthetic corticotrophin-releasing hormone (CRH) intravenously or subjected to restraint stress. Single intravenous administration of CRH increases the number of c-Fos-expressing cells, and this number does not change even if the dose is increased. Double-immunostaining has revealed that most of the c-Fos-expressing cells contain adrenocorticotrophic hormone (ACTH); corticotrophs that do not express c-Fos in response to CRH have also been found. However, restraint stress evokes c-Fos expression in most of the corticotrophs and in a partial population of lactotrophs. These results suggest that c-Fos expression increases in corticotrophs stimulated by ACTH secretagogues, including CRH. Furthermore, we have found restricted numbers of corticotrophs expressing c-Fos in response to CRH. Although the mechanism underlying the different responses to CRH is not apparent, c-Fos is probably a useful immunohistochemical marker for corticotrophs stimulated by ACTH secretagogues.

Active immunization against gonadotropin-releasing hormone : an effective tool to block the fertility axis in mammals

NARCIS (Netherlands)

Turkstra, Jouwert Anne

2005-01-01

Gonadotropin releasing hormone (GnRH) plays a pivotal role in fertility and reproduction in mammals. It induces the release of luteinising hormone (LH) en follicle stimulating hormone (FSH) from the pituitary. These hormones are responsible for gonadal steroid production and indirectly for

Melatonin improves memory acquisition under stress independent of stress hormone release

OpenAIRE

Rimmele, U; Spillmann, M; Bärtschi, C; Wolf, O T; Weber, C S; Ehlert, Ulrike; Wirtz, P H

2009-01-01

RATIONALE: Animal studies suggest that the pineal hormone melatonin influences basal stress hormone levels and dampens hormone reactivity to stress. OBJECTIVES: We investigated whether melatonin also has a suppressive effect on stress-induced catecholamine and cortisol release in humans. As stress hormones affect memory processing, we further examined a possible accompanying modulation of memory function. MATERIALS AND METHODS: Fifty healthy young men received a single oral dose of either 3...

Impact of physicochemical properties of porous silica materials conjugated with dexamethasone via pH-responsive hydrazone bond on drug loading and release behavior

Science.gov (United States)

Numpilai, Thanapha; Witoon, Thongthai; Chareonpanich, Metta; Limtrakul, Jumras

2017-02-01

The conjugation of dexamethasone (DEX) onto modified-porous silica materials via a pH-responsive hydrazone bond has been reported to be highly efficient method to specifically deliver the DEX to diseased sites. However, the influence of physicochemical properties of porous silica materials has not yet been fully understood. In this paper, the impact of pore sizes, particle sizes and silanol contents on surface functionalization, drug loading and release behavior of porous silica materials conjugated with dexamethasone via pH-responsive hydrazone bond was investigated. The grafting density was found to relate to the number of silanol groups on the surface of porous silica materials. The particle size and macropores of the porous silica materials played an vital role on the drug loading and release behavior. Although the porous silica materials with larger particle sizes possessed a lower grafting density, a larger amount of drug loading could be achieved. Moreover, the porous silica materials with larger particle sizes showed a slower release rate of DEX due to a longer distance for cleaved DEX diffusion out of pores. DEX release rate exhibited pH-dependent, sustained release. At pH 4.5, the amount of DEX release within 10 days could be controlled in the range of 12.74-36.41%, depending on the host material. Meanwhile, less than 1.5% of DEX was released from each of type of the porous silica materials at pH 7.4. The results of silica dissolution suggested that the degradation of silica matrix did not significantly affect the release rate of DEX. In addition, the kinetic modeling studies revealed that the DEX releases followed Korsmeyer-Peppas model with a release exponent (n) ranged from 0.3 to 0.47, indicating a diffusion-controlled release mechanism.

Prolonged inhibition of luteinizing hormone and testosterone levels in male rats with the luteinizing hormone-releasing hormone antagonist SB-75.

Science.gov (United States)

Bokser, L; Bajusz, S; Groot, K; Schally, A V

1990-09-01

Inhibitory effects of the potent antagonist of luteinizing hormone-releasing hormone N-Ac-[3-(2-naphthyl)-D-alanine1,4-chloro-D-phenylalanine2,3- (3-pyridyl)-D- alanine3,D-citrulline6,D-alanine10]luteinizing hormone-releasing hormone (SB-75) free of edematogenic effects were investigated in male rats. In a study to determine the effect on luteinizing hormone levels in castrated male rats, SB-75 was injected s.c. in doses of 0.625, 1.25, 2.5, 5.0, and 10 micrograms. Blood samples were taken at different intervals for 48 hr. All doses of SB-75 significantly decreased luteinizing hormone levels for greater than 6 hr (P less than 0.01); this inhibition lasted for greater than 24 hr (P less than 0.01) with a dose of 5.0 micrograms and greater than 48 hr with 10 micrograms (P less than 0.05). Serum testosterone levels were also measured in intact male rats injected with SB-75 in doses of 25, 50, and 100 micrograms. All doses produced a dramatic fall in testosterone to castration levels 6 hr after injection (P less than 0.01); this inhibition of serum testosterone was maintained for greater than 72 hr, but only the 100-micrograms dose could keep testosterone in the castration range for greater than 24 hr (P less than 0.01). In another study using a specific RIA, we obtained the pharmacokinetic release pattern of SB-75 from two sustained delivery formulations of SB-75 pamoate microgranules and examined their effect on serum testosterone. After a single i.m. injection of 20 mg of one batch of microgranules, a large peak corresponding to SB-75 at 45.8 ng/ml was observed, corresponding to the "burst" effect. Levels of the analog decreased to 19.6 ng/ml on day 2, gradually reached a concentration of 4.7 ng/ml on day 7, and kept declining thereafter. Testosterone levels were reduced on day 1 (P less than 0.01) and were maintained at low values for greater than 7 days (P less than 0.05). In rats injected with 10 mg of SB-75 pamoate microgranules of the second batch, SB-75 serum

Effects of ionizing radiation and pretreatment with [D-Leu6,des-Gly10] luteinizing hormone-releasing hormone ethylamide on developing rat ovarian follicles

International Nuclear Information System (INIS)

Jarrell, J.; YoungLai, E.V.; McMahon, A.; Barr, R.; O'Connell, G.; Belbeck, L.

1987-01-01

To assess the effects of a gonadotropin-releasing hormone agonist, [D-Leu6,des-Gly10] luteinizing hormone-releasing hormone ethylamide, in ameliorating the damage caused by ionizing radiation, gonadotropin-releasing hormone agonist was administered to rats from day 22 to 37 of age in doses of 0.1, 0.4, and 1.0 microgram/day or vehicle and the rats were sacrificed on day 44 of age. There were no effects on estradiol, progesterone, luteinizing, or follicle-stimulating hormone, nor an effect on ovarian follicle numbers or development. In separate experiments, rats treated with gonadotropin-releasing hormone agonist in doses of 0.04, 0.1, 0.4, or 1.0 microgram/day were either irradiated or sham irradiated on day 30 and all groups sacrificed on day 44 of age. Irradiation produced a reduction in ovarian weight and an increase in ovarian follicular atresia. Pretreatment with the agonist prevented the reduction in ovarian weight and numbers of primordial and preantral follicles but not healthy or atretic antral follicles. Such putative radioprotection should be tested on actual reproductive performance

Prolactin, thyrotropin, and growth hormone release during stress associated with parachute jumping.

Science.gov (United States)

Noel, G L; Dimond, R C; Earll, J M; Frantz, A G

1976-05-01

Prolactin, growth hormone, and thyrotropin (TSH) release during the stress of parachute jumping has been evaluated in 14 male subjects. Subjects were studied at several times before and immediately after their first military parachute jump. All three hormones had risen significantly 1 to 14 min after the jump, compared to mean levels measured immediately beforehand. Earlier studies of physical exercise by ourselves and others would suggest that emotional stress played a role in producing changes of this magnitude. We conclude that prolactin, TSH, and growth hormone are released in physiologically significant amounts in association with the stress of parachute jumping.

Diseases associated with growth hormone-releasing hormone receptor (GHRHR) mutations.

Science.gov (United States)

Martari, Marco; Salvatori, Roberto

2009-01-01

The growth hormone (GH)-releasing hormone (GHRH) receptor (GHRHR) belongs to the G protein-coupled receptors family. It is expressed almost exclusively in the anterior pituitary, where it is necessary for somatotroph cells proliferation and for GH synthesis and secretion. Mutations in the human GHRHR gene (GHRHR) can impair ligand binding and signal transduction, and have been estimated to cause about 10% of autosomal recessive familial isolated growth hormone deficiency (IGHD). Mutations reported to date include five splice donor site mutations, two microdeletions, two nonsense mutations, seven missense mutations, and one mutation in the promoter. These mutations have an autosomal recessive mode of inheritance, and heterozygous individuals do not show signs of IGHD, although the presence of an intermediate phenotype has been hypothesized. Conversely, patients with biallelic mutations have low serum insulin-like growth factor-1 and GH levels (with absent or reduced GH response to exogenous stimuli), resulting--if not treated--in proportionate dwarfism. This chapter reviews the biology of the GHRHR, the mutations that affect its gene and their effects in homozygous and heterozygous individuals. Copyright © 2009 Elsevier Inc. All rights reserved.

Dexamethasone-loaded poly(3-hydroxybutyrate-co-3-hydroxyvalerate) microparticles for controlled release

International Nuclear Information System (INIS)

Riekes, Manoela Klueppel; Paula, Josiane Padilha de; Farago, Paulo Vitor; Zawadzki, Sonia Faria

2009-01-01

Dexamethasone (DEX) has been widely used for the treatment of ulcerative colitis. The aim of the present study was to obtain DEX-loaded poly(3-hydroxybutyrate-co-3-hydroxyvalerate (PHBV) microparticles prepared by simple emulsion/solvent evaporation method. The drug loading and the encapsulation efficiency were determined by a previously validated UV method at 233 nm. Morphological, spectroscopical and dissolution analyses were also performed. The microparticles (formulation F no. 0, F no. 1 and F no. 2) were successfully obtained as off-white powders. A drug loading of 92.27 mg.g -1 and 218.54 mg.g -1 and an encapsulation efficiency of 93.96 % and 87.43 % were respectively observed for F no. 1 and F no. 2. Particles showed spherical and rough aspect by SEM. X-ray diffraction analysis demonstrated that the encapsulation reduced the drug crystallinity. FTIR spectra showed that no chemical bonding occurred between PHBV and DEX. Drug-loaded microparticles revealed controlled release profiles compared to pure DEX. (author)

Self-assembled rosette nanotubes encapsulate and slowly release dexamethasone

Directory of Open Access Journals (Sweden)

Chen Y

2011-05-01

Full Text Available Yupeng Chen1,2, Shang Song2, Zhimin Yan3, Hicham Fenniri3, Thomas J Webster2,41Department of Chemistry, Brown University, Providence, RI, USA; 2School of Engineering, Brown University, Providence, RI, USA; 3National Institute for Nanotechnology and Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada; 4Department of Orthopedics, Brown University, Providence, RI, USAAbstract: Rosette nanotubes (RNTs are novel, self-assembled, biomimetic, synthetic drug delivery materials suitable for numerous medical applications. Because of their amphiphilic character and hollow architecture, RNTs can be used to encapsulate and deliver hydrophobic drugs otherwise difficult to deliver in biological systems. Another advantage of using RNTs for drug delivery is their biocompatibility, low cytotoxicity, and their ability to engender a favorable, biologically-inspired environment for cell adhesion and growth. In this study, a method to incorporate dexamethasone (DEX, an inflammatory and a bone growth promoting steroid into RNTs was developed. The drug-loaded RNTs were characterized using diffusion ordered nuclear magnetic resonance spectroscopy (DOSY NMR and UV-Vis spectroscopy. Results showed for the first time that DEX can be easily and quickly encapsulated into RNTs and released to promote osteoblast (bone-forming cell functions over long periods of time. As a result, RNTs are presented as a novel material for the targeted delivery of hydrophobic drugs otherwise difficult to deliver.Keywords: nanotubes, drug delivery, self-assembly, physiological conditions

Up-regulation of corticotropin releasing hormone is associated with ...

African Journals Online (AJOL)

Purpose: To determine the expression of corticotropin-releasing hormone (CRH) in psoriasis and ... Methods: Psoriasis and normal skin biopsy samples were obtained from three psoriatic and ... established in literature that stress signals such.

Bilateral inferior petrosal sinus sampling using vasopressin

Directory of Open Access Journals (Sweden)

Narendra Kotwal

2016-01-01

Full Text Available Context: Anatomical localization of pituitary adenoma can be challenging in adrenocorticotropic hormone (ACTH-dependent Cushing's syndrome, and bilateral inferior petrosal sinus sampling (BIPSS is considered gold standard in this regard. Stimulation using corticotrophin-releasing hormone (CRH improves the sensitivity of BIPSS, however, same is not easily available in India. Therefore, we undertook this study of BIPPS using vasopressin as agent for stimulation owing to its ability to stimulate V3 receptors present on corticotrophs. Aims: To study the tumor localization and lateralization in difficult to localize cases of ACTH-dependent Cushing's syndrome by bilateral inferior petrosal sinus sampling using vasopressin for corticotroph stimulation. Settings and Design: Prospective observational study. Subjects and Methods: Six patients (5 females meeting inclusion criteria underwent BIPSS using vasopressin for stimulation. Results: All six patients had nonsuppressible overnight and low dose dexamethasone suppression test with elevated plasma ACTH levels suggestive of ACTH-dependent Cushing's syndrome. High dose dexamethasone suppression test showed suppressible cortisol in two cases, and microadenoma was seen in two patients on magnetic resonance imaging pituitary. Contrast enhanced computed tomography of the abdomen showed left adrenal hyperplasia in one case and anterior mediastinal mass with bilateral adrenal hyperplasia another. Using BIPSS four patients were classified as having Cushing's disease that was confirmed histopathologically following surgery. Of the remaining two, one had primary pigmented nodular adrenocortical disease, and another had thymic carcinoid with ectopic ACTH production as the cause of Cushing's syndrome. No serious adverse events were noted. Conclusions: Vasopressin may be used instead of CRH and desmopressin for stimulation in BIPSS.

Bisphenol A differentially activates protein kinase C isoforms in murine placental tissue

Energy Technology Data Exchange (ETDEWEB)

Tan, Wenjuan; Huang, Hui; Wang, Yanfei [Biochemistry Programme, School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Shatin, N.T. (Hong Kong); Wong, Tsz Yan [Food and Nutritional Sciences Programme, School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Shatin, N.T. (Hong Kong); Wang, C.C. [Department of Obstetrics and Gynecology, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, N.T. (Hong Kong); Leung, Lai K., E-mail: laikleung@cuhk.edu.hk [Biochemistry Programme, School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Shatin, N.T. (Hong Kong); Food and Nutritional Sciences Programme, School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Shatin, N.T. (Hong Kong)

2013-06-01

Bisphenol A is utilized to make polycarbonate plastics and is an environmental pollutant. Recent research has indicated that it is an endocrine disruptor and may interfere with reproductive processes. Our lab has previously shown that bisphenol A could regulate corticotrophin releasing hormone and aromatase in cultured placental cells. In the present study, the effect of bisphenol A on these two genes in the placenta was investigated in mice. Pregnant ICR mice were gavaged with bisphenol A at 2, 20 and 200 mg/kg body weight/day from E13 to E16 and were euthanized at E17. Compared to the control mice, increased plasma estrogen and corticotrophin releasing hormone were observed in bisphenol A-treated mice. Messenger RNA quantification indicated that placental crh but not cyp19 was induced in mice treated with bisphenol A. Tracking the related signaling pathway, we found that protein kinase C ζ/λ and δ were activated in the placentas of bisphenol A-treated mice. As the gene promoter of crh contains CRE and the half site of ERE, either phospho-PKC or estrogen could stimulate the gene transactivation. These results indicate that bisphenol A might increase plasma concentrations of estradiol, testosterone, corticotrophin releasing hormone and placental phospho-PKC ζ/λ and δ in mice. Ultimately, the incidence of premature birth in these mice could increase. - Highlights: • The pollutant bisphenol A differentially activated PKC isoforms in the placenta. • CRE-binding activity in the nuclear protein of placenta was increased. • Bisphenol A induces CRH mRNA expression in mice.

Bisphenol A differentially activates protein kinase C isoforms in murine placental tissue

International Nuclear Information System (INIS)

Tan, Wenjuan; Huang, Hui; Wang, Yanfei; Wong, Tsz Yan; Wang, C.C.; Leung, Lai K.

2013-01-01

Bisphenol A is utilized to make polycarbonate plastics and is an environmental pollutant. Recent research has indicated that it is an endocrine disruptor and may interfere with reproductive processes. Our lab has previously shown that bisphenol A could regulate corticotrophin releasing hormone and aromatase in cultured placental cells. In the present study, the effect of bisphenol A on these two genes in the placenta was investigated in mice. Pregnant ICR mice were gavaged with bisphenol A at 2, 20 and 200 mg/kg body weight/day from E13 to E16 and were euthanized at E17. Compared to the control mice, increased plasma estrogen and corticotrophin releasing hormone were observed in bisphenol A-treated mice. Messenger RNA quantification indicated that placental crh but not cyp19 was induced in mice treated with bisphenol A. Tracking the related signaling pathway, we found that protein kinase C ζ/λ and δ were activated in the placentas of bisphenol A-treated mice. As the gene promoter of crh contains CRE and the half site of ERE, either phospho-PKC or estrogen could stimulate the gene transactivation. These results indicate that bisphenol A might increase plasma concentrations of estradiol, testosterone, corticotrophin releasing hormone and placental phospho-PKC ζ/λ and δ in mice. Ultimately, the incidence of premature birth in these mice could increase. - Highlights: • The pollutant bisphenol A differentially activated PKC isoforms in the placenta. • CRE-binding activity in the nuclear protein of placenta was increased. • Bisphenol A induces CRH mRNA expression in mice

Sustained release ophthalmic dexamethasone: In vitro in vivo correlations derived from the PK-Eye.

Science.gov (United States)

Awwad, Sahar; Day, Richard M; Khaw, Peng T; Brocchini, Steve; Fadda, Hala M

2017-04-30

Corticosteroids have long been used to treat intraocular inflammation by intravitreal injection. We describe dexamethasone loaded poly-DL-lactide-co-glycolide (PLGA) microparticles that were fabricated by thermally induced phase separation (TIPS). The dexamethasone loaded microparticles were evaluated using a two-compartment, in vitro aqueous outflow model of the eye (PK-Eye) that estimates drug clearance time from the back of the eye via aqueous outflow by the anterior route. A dexamethasone dose of 0.20±0.02mg in a 50μL volume of TIPS microparticles resulted in a clearance t 1/2 of 9.6±0.3days using simulated vitreous in the PK-Eye. Since corticosteroids can also clear through the retina, it is necessary to account for clearance through the back of the eye. Retinal permeability data, published human ocular pharmacokinetics (PK) and the PK-Eye clearance times were then used to establish in vitro in vivo correlations (IVIVCs) for intraocular clearance times of corticosteroid formulations. A t 1/2 of 48h was estimated for the dexamethasone-TIPS microparticles, which is almost 9 times longer than that reported for dexamethasone suspension in humans. The prediction of human clearance times of permeable molecules from the vitreous compartment can be determined by accounting for drug retinal permeation and determining the experimental clearance via the anterior aqueous outflow pathway using the PK-Eye. Copyright © 2017. Published by Elsevier B.V.

Prevention of everolimus-related stomatitis in women with hormone receptor-positive, HER2-negative metastatic breast cancer using dexamethasone mouthwash (SWISH): a single-arm, phase 2 trial.

Science.gov (United States)

Rugo, Hope S; Seneviratne, Lasika; Beck, J Thaddeus; Glaspy, John A; Peguero, Julio A; Pluard, Timothy J; Dhillon, Navneet; Hwang, Leon Christopher; Nangia, Chaitali; Mayer, Ingrid A; Meiller, Timothy F; Chambers, Mark S; Sweetman, Robert W; Sabo, J Randy; Litton, Jennifer K

2017-05-01

Stomatitis is a class effect associated with the inhibition of mTOR and is associated with everolimus therapy for breast cancer. Topical steroids might reduce stomatitis incidence and severity, and the need for dose reductions and interruptions of everolimus. Anecdotal use of topical steroid oral prophylaxis has been reported in patients with breast cancer. We aimed to assess dexamethasone-based mouthwash for prevention of stomatitis in patients with breast cancer. This US-based, multicentre, single-arm, phase 2 prevention study enrolled women aged 18 years and older with postmenopausal status who had histologically or cytologically confirmed metastatic hormone receptor-positive, HER2-negative breast cancer. Beginning on day 1 of cycle 1, patients received everolimus 10 mg plus exemestane 25 mg daily, with 10 mL of alcohol-free dexamethasone 0·5 mg per 5 mL oral solution (swish for 2 min and spit, four times daily for 8 weeks). After 8 weeks, dexamethasone mouthwash could be continued for up to eight additional weeks at the discretion of the clinician and patient. The primary endpoint was incidence of grade 2 or worse stomatitis by 8 weeks assessed in the full analysis set (patients who received at least one dose of everolimus and exemestane and at least one confirmed dose of dexamethasone mouthwash) versus historical controls from the BOLERO-2 trial (everolimus and exemestane treatment in patients with hormone receptor-positive advanced breast cancer who were not given dexamethasone mouthwash for prevention of stomatitis). This trial is registered at ClinicalTrials.gov, number NCT02069093. Between May 28, 2014, and Oct 8, 2015, we enrolled 92 women; 85 were evaluable for efficacy. By 8 weeks, the incidence of grade 2 or worse stomatitis was two (2%) of 85 patients (95% CI 0·29-8·24), versus 159 (33%) of 482 patients (95% CI 28·8-37·4) for the duration of the BOLERO-2 study. Overall, 83 (90%) of 92 patients had at least one adverse event. The most frequently

Regulation of ODC activity in the thymus and liver of rats by adrenal hormones.

Science.gov (United States)

Zahner, S L; Prahlad, K V; Mitchell, J L

1986-01-01

The activity of L-ornithine decarboxylase (EC 4.1.1.17, ODC) has become a useful indicator of hormone responsiveness. Various regimens of dexamethasone, aldosterone and epinephrine, alone or in combination, were administered to adrenalectomized rats either in acute or chronic doses. In addition, adrenalectomized rats, which were chronically treated with aldosterone and epinephrine, were given a single injection of 50 micrograms dexamethasone and sacrificed at various time intervals after hormone treatment. Hepatic and thymic ODC activity was measured. The expected dexamethasone effect, an increase in hepatic and a decrease in thymic ODC, was observed. This study also revealed that aldosterone induced similar responses in these tissues. Epinephrine had the opposite effect since chronic administration of dexamethasone or aldosterone with epinephrine resulted in control levels of ODC. Furthermore, when aldosterone and epinephrine were chronically administered to adrenalectomized rats, to study the acute effects of dexamethasone on rat thymus and liver, the time course of the response in each tissue was found to be distinct. The influence of the adrenal gland on rat thymus and liver is not restricted only to glucocorticoids, but may also involve other hormones which it secretes.

Corticotropin-releasing hormone-mediated metamorphosis in the neotenic axolotl Ambystoma mexicanum: synergistic involvement of thyroxine and corticoids on brain type II deiodinase.

Science.gov (United States)

Kühn, Eduard R; De Groef, Bert; Van der Geyten, Serge; Darras, Veerle M

2005-08-01

In the present study, morphological changes leading to complete metamorphosis have been induced in the neotenic axolotl Ambystoma mexicanum using a submetamorphic dose of T(4) together with an injection of corticotropin-releasing hormone (CRH). An injection of CRH alone is ineffective in this regard presumably due to a lack of thyrotropic stimulation. Using this low hormone profile for induction of metamorphosis, the deiodinating enzymes D2 and D3 known to be present in amphibians were measured in liver and brain 24h following an intraperitoneal injection. An injection of T(4) alone did not influence liver nor brain D2 and D3, but dexamethasone (DEX) or CRH alone or in combination with T(4) decreased liver D2 and D3. Brain D2 activity was slightly increased with a higher dose of DEX, though CRH did not have this effect. A profound synergistic effect occurred when T(4) and DEX or CRH were injected together, in the dose range leading to metamorphosis, increasing brain D2 activity more than fivefold. This synergistic effect was not found in the liver. It is concluded that brain T(3) availability may play an important role for the onset of metamorphosis in the neotenic axolotl.

Pituitary adenomas in mice transgenic for growth hormone-releasing hormone

DEFF Research Database (Denmark)

Asa, S L; Kovacs, K; Stefaneanu, L

1992-01-01

It has been shown that mice transgenic for human GH-releasing hormone (GRH) develop hyperplasia of pituitary somatotrophs, lactotrophs, and mammosomatotrophs, cells capable of producing both GH and PRL, by 8 months of age. We now report that GRH transgenic mice 10-24 months of age develop pituitary...... adenomas, which we characterized by histology, immunohistochemistry, in situ hybridization, and electron microscopy. Of 13 animals examined, all developed GH-immunoreactive neoplasms that had diffuse positivity for GH mRNA by in situ hybridization. Eleven also contained PRL immunoreactivity; in situ...

Lower testosterone levels with luteinizing hormone-releasing hormone agonist therapy than with surgical castration: new insights attained by mass spectrometry

NARCIS (Netherlands)

van der Sluis, Tim M.; Bui, Hong N.; Meuleman, Eric J. H.; Heijboer, Annemieke C.; Hartman, Jeroen F.; van Adrichem, Nick; Boevé, Egbert; de Ronde, Willem; van Moorselaar, R. Jeroen A.; Vis, André N.

2012-01-01

Androgen deprivation therapy by bilateral orchiectomy (surgical castration) or luteinizing hormone-releasing hormone agonist therapy (medical castration) is recommended for advanced or metastatic prostate cancer. Both methods aim at reducing serum testosterone concentrations to a castrate level

Radioimmunoassay of thyrotropin releasing hormone in plasma and urine

International Nuclear Information System (INIS)

Saito, Shiro; Musa, Kimitaka; Yamamoto, Suzuyo; Oshima, Ichiyo; Funato, Toyohiko

1975-01-01

A sensitive and specific radioimmunoassay has been developed capable of measuring thyrotropin releasing hormone (TRH) in extracted human plasma and urine. All of three TRH analogues tested had little cross-reactivity to antibody. Luteinizing hormone releasing hormone, lysine vasopressin, rat growth hormone and bovine albumin were without effect, but rat hypothalamic extract produced a displacement curve which was parallel to that obtained with the synthetic TRH. Sensitivity of the radioimmunoassay was 4 pg per tube with intraassay coefficient of variation of 6.2-9.7%. Synthetic TRH could be quantitatively extracted by methanol when added to human plasma in concentration of 25, 50 and 100 pg/ml. TRH immunoreactivity was rapidly reduced in plasma at 20 0 C than at 0 0 C, but addition of peptidase inhibitors, FOY-007 and BAL, prevented the inactivation of TRH for 3 hr at 0 0 C. The TRH in urine was more stable at 0 0 C than 20 0 C, and recovered 75+-4.6% at 24 hr after being added. The plasma levels of TRH were 19 pg/ml or less in normal adults and no sex difference was observed. The rate of disappearance of TRH administered i.v. from the blood could be represented as half-times of 4-12 min. Between 5.3-12.3% of the injected dose was excreted into urine within 1 hr as an immunoreactive TRH. These results indicate the usefulness of TRH radioimmunoassay for clinical investigation. (auth.)

Different growth hormone (GH) response to GH-releasing peptide and GH-releasing hormone in hyperthyroidism.

Science.gov (United States)

Ramos-Dias, J C; Pimentel-Filho, F; Reis, A F; Lengyel, A M

1996-04-01

Altered GH responses to several pharmacological stimuli, including GHRH, have been found in hyperthyroidism. The mechanisms underlying these disturbances have not been fully elucidated. GH-releasing peptide-6 (GHRP-6) is a synthetic hexapeptide that specifically stimulates GH release both in vitro and in vivo. The mechanism of action of GHRP-6 is unknown, but it probably acts by inhibiting the effects of somatostatin on GH release. The aim of this study was to evaluate the effects of GHRP-6 on GH secretion in patients with hyperthyroidism (n = 9) and in control subjects (n = 9). Each subject received GHRP-6 (1 microg/kg, iv), GHRH (100 microg, iv), and GHRP-6 plus GHRH on 3 separate days. GH peak values (mean +/- SE; micrograms per L) were significantly lower in hyperthyroid patients compared to those in control subjects after GHRH alone (9.0 +/- 1.3 vs. 27.0 +/- 5.2) and GHRP-6 plus GHRH (22.5 +/- 3.5 vs. 83.7 +/- 15.2); a lack of the normal synergistic effect of the association of both peptides was observed in thyrotoxicosis. However, a similar GH response was seen in both groups after isolated GHRP-6 injection (31.9 +/- 5.7 vs. 23.2 +/- 3.9). In summary, we have shown that hyperthyroid patients have a normal GH response to GHRP-6 together with a blunted GH responsiveness to GHRH. Our data suggest that thyroid hormones modulate GH release induced by these two peptides in a differential way.

Effects of dexamethasone on palate mesenchymal cell phospholipase activity

International Nuclear Information System (INIS)

Bulleit, R.F.; Zimmerman, E.F.

1984-01-01

Corticosteroids will induce cleft palate in mice. One suggested mechanism for this effect is through inhibition of phospholipase activity. This hypothesis was tested by measuring the effects of dexamethasone, a synthetic corticosteroid, on phospholipase activity in cultures of palate mesenchymal cells. Palate mesenchymal cells were prelabeled with [3H]arachidonic acid. The cells were subsequently treated with various concentrations of dexamethasone. Concurrently, cultures of M-MSV-transformed 3T3 cells were prepared identically. After treatment, phospholipase activity was stimulated by the addition of serum or epidermal growth factor (EGF), and radioactivity released into the medium was taken as a measure of phospholipase activity. Dexamethasone (1 X 10(-5) or 1 X 10(-4) M) could inhibit serum-stimulated phospholipase activity in transformed 3T3 cells after 1 to 24 hr of treatment. However, no inhibition of activity was measured in palate mesenchymal cells following this period of treatment. Not until 120 hr of treatment with dexamethasone (1 X 10(-4) M) was any significant inhibition of serum-stimulated phospholipase activity observed in palate mesenchymal cells. When EGF was used to stimulate phospholipase activity, dexamethasone (1 X 10(-5) M) caused an increase in phospholipase activity in palate mesenchymal cells. These observations suggested that phospholipase in transformed 3T3 cells was sensitive to inhibition by dexamethasone. However, palate mesenchymal cell phospholipase is only minimally sensitive to dexamethasone, and in certain instances can be enhanced. These results cannot support the hypothesis that corticosteroids mediate their teratogenic effect via inhibition of phospholipase activity

Endurance exercise modulates levodopa induced growth hormone release in patients with Parkinson's disease.

Science.gov (United States)

Müller, Thomas; Welnic, Jacub; Woitalla, Dirk; Muhlack, Siegfried

2007-07-11

Acute levodopa (LD) application and exercise release human growth hormone (GH). An earlier trial showed, that combined stimulus of exercise and LD administration is the best provocative test for GH response in healthy participants. Objective was to show this combined effect of LD application and exercise on GH response and to investigate the impact on LD metabolism in 20 previously treated patients with Parkinson's disease (PD). We measured GH- and LD plasma concentrations following soluble 200 mg LD/50 mg benserazide administration during endurance exercise and rest on two separate consecutive days. GH concentrations significantly increased on both days, but GH release was significantly delayed during rest. LD metabolism was not altered due to exercise in a clinical relevant manner. Exercise induced a significant faster LD stimulated GH release in comparison with the rest condition. We did not find the supposed increase of LD induced GH release by endurance exercise. We assume, that only a limited amount of GH is available for GH release in the anterior pituitary following an acute 200 mg LD administration. GH disposal also depends on growth hormone releasing hormone (GHRH), which is secreted into hypothalamic portal capillaries. During the exercise condition, the resulting higher blood pressure supports blood flow and thus GHRH transport towards the GH producing cells in the pituitary. This might additionally have caused the significant faster GH release during exercise.

Action of luteinizing hormone-releasing hormone in rat ovarian cells: Hormone production and signal transduction

Energy Technology Data Exchange (ETDEWEB)

Wang, Jian.

1989-01-01

The present study was conducted to investigate the hypothesis that the breakdown of membrane phosphoinositides may participate in the actions of luteinizing hormone-releasing hormone (LHRH) on hormone production in rat granulosa cells. In cells prelabeled with ({sup 3}H)inositol or ({sup 3}H)arachidonic acid (AA), treatment with LHRH increased the formation of radiolabeled inositol 1,4,5-trisphosphate (IP{sub 3}) and diacylglycerol (DG), and the release of radiolabeled AA. Since IP{sub 3} induces intracellular Ca{sup 2+} mobilization, changes in the cytosolic free calcium ion concentrations ((Ca{sup 2+})i) induced by LHRH were studied in individual cells using fura-2 microspectrofluorimetry. Alterations in (Ca{sup 2+})i induced by LHRH were rapid and transient, and could be completely blocked by a LHRH antagonist. Sustained perifusion of LHRH resulted in a desensitization of the (Ca{sup 2+})i response to LHRH. LHRH treatment accelerated (Ca{sup 2+})i depletion in the cells perifused with Ca{sup 2+} free medium, indicating the involvement of intracellular Ca{sup 2+} pool(s) in (Ca{sup 2+})i changes. The actions of LHRH on the regulation of progesterone (P{sub 4}) and prostaglandin E{sub 2} (PGE{sub 2}) production were also examined. LHRH increased basal P{sub 4} production and attenuated FSH induced P{sub 4} production. Both basal and FSH stimulated PGE{sub 2} formation were increased by LHRH. Since LHRH also increased the formation of DG that stimulates the activity of protein kinase C, an activator of protein kinase C (12-0-tetradecanolyphorbol-13-acetate: TPA) was used with the Ca{sup 2+} ionophore A23187 and melittin (an activator of phospholipase A{sub 2}) to examine the roles of protein kinase C, Ca{sup 2+} and free AA, respectively, in LHRH action.

Potent agonists of growth hormone-releasing hormone. Part I.

Science.gov (United States)

Zarandi, M; Serfozo, P; Zsigo, J; Bokser, L; Janaky, T; Olsen, D B; Bajusz, S; Schally, A V

1992-03-01

Analogs of the 29 amino acid sequence of growth hormone-releasing hormone (GH-RH) with agmatine (Agm) in position 29 have been synthesized by the solid phase method, purified, and tested in vitro and in vivo. The majority of the analogs contained desaminotyrosine (Dat) in position 1, but a few of them had Tyr1, or N-MeTyr1. Some peptides contained one or more additional L- or D-amino acid substitutions in positions 2, 12, 15, 21, 27, and/or 28. Compared to the natural sequence of GH-RH(1-29)NH2, [Dat1,Ala15]GH-RH(1-28)Agm (MZ-3-191) and [D-Ala2,Ala15]GH-RH(1-28)Agm (MZ-3-201) were 8.2 and 7.1 times more potent in vitro, respectively. These two peptides contained Met27. Their Nle27 analogs, [Dat1,Ala15,Nle27]GH-RH(1-28)Agm(MZ-2-51), prepared previously (9), and [D-Ala2,Ala15,Nle28]GH-RH(1-28)Agm(MZ-3-195) showed relative in vitro potencies of 10.5 and 2.4, respectively. These data indicate that replacement of Met27 by Nle27 enhanced the GH-releasing activity of the analog when the molecule contained Dat1-Ala2 residues at the N-terminus, but peptides containing Tyr1-D-Ala2 in addition to Nle27 showed decreased potencies. Replacement of Ser28 with Asp in multi-substituted analogs of GH-RH(1-28)Agm resulted in a decrease in in vitro potencies compared to the parent compound. Thus, the Ser28-containing MZ-2-51, and [Dat1,Ala15,D-Lys21,Nle27]GH-RH(1-28)Agm, its Asp28 homolog (MZ-3-149), possessed relative activities of 10.5 and 5.6, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluating the patient experience after implantation of a 0.4 mg sustained release dexamethasone intracanalicular insert (DextenzaTM: results of a qualitative survey

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Gira JP

2017-03-01

Full Text Available Joseph P Gira,1 Reginald Sampson,2 Steven M Silverstein,3 Thomas R Walters,4 Jamie Lynne Metzinger,5 Jonathan H Talamo5 1Ophthalmology Consultants, St Louis, MO, 2Montebello Medical Center, Inc., Montebello, CA, 3Silverstein Eye Centers, Kansas City, MO, 4Texan Eye, Austin, TX, 5Ocular Therapeutix, Inc., Bedford, MA, USA Purpose: The purpose of this study is to evaluate the patient experience of sustained release dexamethasone intracanalicular insert (Dextenza™ following cataract surgery as part of a Phase III clinical trial program. Methods: This cross-sectional, qualitative evaluation involved individual interviews lasting approximately 45 minutes. Patients from four US investigational study sites who had previously received an insert were enrolled. There were no predesignated end points; this was a qualitative survey seeking a deeper understanding of patient experience. Results: Twenty-five patients were interviewed. Most patients (92% reported the highest level of satisfaction grade with regard to overall product satisfaction. All patients described the insert as comfortable. Most patients (96% described their overall experience with the insert as very convenient or extremely convenient. Twenty-two of 23 (96% participants rated their experience with the insert as “very” or “extremely convenient”, compared to previous topical therapy, and 88% of patients stated that if they were to undergo cataract surgery again, they would request the insert. When asked if they would recommend the insert to family members or friends, 92% stated they would. The survey found that 84% of participants would be willing to pay more for the insert than for eye drop therapy. Conclusion: The dexamethasone insert was found by patients to be highly favorable with regard to overall satisfaction, convenience, and comfort. The insert was well received and largely preferred over topical therapy alternatives following surgery. More extensive evaluation of the

Pulsatile luteinising hormone releasing hormone for ovulation induction in subfertility associated with polycystic ovary syndrome

NARCIS (Netherlands)

Bayram, N.; van Wely, M.; Vandekerckhove, P.; Lilford, R.; van der Veen, F.

2000-01-01

BACKGROUND: In normal menstrual cycles, gonadotrophin releasing hormone (GnRH) secretion is pulsatile, with intervals of 60-120 minutes in the follicular phase. Treatment with pulsatile GnRH infusion by the intra-venous or subcutaneous route using a portable pump has been used successfully in

Dexamethasone prolongs local analgesia after subcutaneous infiltration of bupivacaine microcapsules in human volunteers

DEFF Research Database (Denmark)

Holte, Kathrine; Werner, Mads U; Lacouture, Peter G

2002-01-01

BACKGROUND: The addition of small amounts of dexamethasone to extended-release formulations of bupivacaine in microcapsules has been found to prolong local analgesia in experimental studies, but no clinical data are available. METHODS: In a double-blinded study, 12 healthy male volunteers were...... randomized to receive simultaneous subcutaneous injections of bupivacaine microcapsules with dexamethasone and bupivacaine microcapsules without dexamethasone in each calf. Local analgesia was assessed with a validated human pain model; main parameters evaluated were thermal, mechanical, and pain detection...... curve [AUC]) were considered best estimate of analgesia. Safety evaluations were performed daily for the first week and at 2 weeks, 6 weeks, and 6 months after injection. RESULTS: The addition of dexamethasone significantly prolonged local analgesia of bupivacaine microcapsules without influence...

Up-regulation of corticotropin releasing hormone is associated with ...

African Journals Online (AJOL)

Purpose: To determine the expression of corticotropin-releasing hormone (CRH) in psoriasis and normal skin biopsy samples, and to correlate the expression of CRH with the expression of CRHBP and inflammatory cytokines IL-8 and IL-33. Methods: Psoriasis and normal skin biopsy samples were obtained from three ...

Effects of thyroxine and dexamethasone on rat submandibular glands

International Nuclear Information System (INIS)

Sagulin, G.B.; Roomans, G.M.

1989-01-01

Glucocorticoids and thyroxine are known to have a marked effect on the flow rate and protein composition of rat parotid saliva in hormonally intact animals. In the present study, the effects of a one-week treatment of male rats with dexamethasone and thyroxine were studied by electron microscopy and x-ray micro-analysis, and by measurement of the flow rate and determination of the chemical composition of pilocarpine-induced submandibular saliva. Thyroxine had the most extensive effects on the submandibular gland. The acinar cells were enlarged and filled with mucus; the cellular calcium concentration was significantly increased. The flow rate of the submandibular saliva was significantly reduced compared with that in saline-injected control animals. Thyroxine caused an increase in the concentrations of protein, total calcium, and potassium in the saliva. Dexamethasone had no significant effects on gland ultrastructure or on the elemental composition of the acinar cells; flow rate was not affected, but the concentrations of protein, calcium, and potassium were significantly increased. The effects of dexamethasone and thyroxine on the flow rate and protein composition of pilocarpine-induced rat submandibular saliva differ from those reported earlier for rat parotid saliva after simultaneous stimulation with pilocarpine and isoproterenol

Estradiol-Dependent Stimulation and Suppression of Gonadotropin-Releasing Hormone Neuron Firing Activity by Corticotropin-Releasing Hormone in Female Mice.

Science.gov (United States)

Phumsatitpong, Chayarndorn; Moenter, Suzanne M

2018-01-01

Gonadotropin-releasing hormone (GnRH) neurons are the final central regulators of reproduction, integrating various inputs that modulate fertility. Stress typically inhibits reproduction but can be stimulatory; stress effects can also be modulated by steroid milieu. Corticotropin-releasing hormone (CRH) released during the stress response may suppress reproduction independent of downstream glucocorticoids. We hypothesized CRH suppresses fertility by decreasing GnRH neuron firing activity. To test this, mice were ovariectomized (OVX) and either implanted with an estradiol capsule (OVX+E) or not treated further to examine the influence of estradiol on GnRH neuron response to CRH. Targeted extracellular recordings were used to record firing activity from green fluorescent protein-identified GnRH neurons in brain slices before and during CRH treatment; recordings were done in the afternoon when estradiol has a positive feedback effect to increase GnRH neuron firing. In OVX mice, CRH did not affect the firing rate of GnRH neurons. In contrast, CRH exhibited dose-dependent stimulatory (30 nM) or inhibitory (100 nM) effects on GnRH neuron firing activity in OVX+E mice; both effects were reversible. The dose-dependent effects of CRH appear to result from activation of different receptor populations; a CRH receptor type-1 agonist increased firing activity in GnRH neurons, whereas a CRH receptor type-2 agonist decreased firing activity. CRH and specific agonists also differentially regulated short-term burst frequency and burst properties, including burst duration, spikes/burst, and/or intraburst interval. These results indicate that CRH alters GnRH neuron activity and that estradiol is required for CRH to exert both stimulatory and inhibitory effects on GnRH neurons. Copyright © 2018 Endocrine Society.

Pituitary response to thyrotropin releasing hormone in children with overweight and obesity.

Science.gov (United States)

Rijks, Jesse; Penders, Bas; Dorenbos, Elke; Straetemans, Saartje; Gerver, Willem-Jan; Vreugdenhil, Anita

2016-08-03

Thyroid stimulating hormone (TSH) concentrations in the high normal range are common in children with overweight and obesity, and associated with increased cardiovascular disease risk. Prior studies aiming at unravelling the mechanisms underlying these high TSH concentrations mainly focused on factors promoting thyrotropin releasing hormone (TRH) production as a cause for high TSH concentrations. However, it is unknown whether TSH release of the pituitary in response to TRH is affected in children with overweight and obesity. Here we describe TSH release of the pituitary in response to exogenous TRH in 73 euthyroid children (39% males) with overweight or (morbid) obesity. Baseline TSH concentrations (0.9-5.5 mU/L) were not associated with BMI z score, whereas these concentrations were positively associated with TSH concentrations 20 minutes after TRH administration (r(2) = 0.484, p obesity. The clinical significance and the intermediate factors contributing to pituitary TSH release need to be elucidated in future studies.

Bone Mass in Young Adulthood Following Gonadotropin-Releasing Hormone Analog Treatment and Cross-Sex Hormone Treatment in Adolescents With Gender Dysphoria

NARCIS (Netherlands)

Klink, D.T.; Caris, M.G.; Heijboer, A.C.; van Trotsenburg, M.; Rotteveel, J.

2015-01-01

Context: Sex steroids are important for bone mass accrual. Adolescents with gender dysphoria (GD) treated with gonadotropin-releasing hormone analog (GnRHa) therapy are temporarily sex-steroid deprived until the addition of cross-sex hormones (CSH). The effect of this treatment on bone mineral

The experimental study of the effect of dexamethasone, lidocaine and contrast medium on the activity of collagenase

International Nuclear Information System (INIS)

Wu Zhiqun; Liu Weimin; Li Zhonghua; Yang Peng

2007-01-01

Objective: To study the effects of hormone, anesthetic and contrast medium on the activities of collagenase lysis. Methods: Nuclear tissues were divided into equal amount for different groups and same units of collagenase were used for the lysis. The only difference in the control group from experimental groups was that there were no dexamethasone, lidocaine or omnipaque but existing in experimental groups. Twenty four hours later, the concentrations of the hydroxyproline were determined in different groups and the data were analyzed by statistical software with computer. Results: 1. The concentrations of hydroxyproline in the dexamethasone group, lidocaine group and omnipaque group were significantly lower than that of control group, especially that of lidocaine group, P value was <0.05 or 0.01. 2. The concentrations of hydroxyproline in the dexamethasone + lidocaine group, dexamethasone + omnipaque group, lidocaine+omnipaque group and dexamethasone + lidocaine + omnipaque group were significantly lower than that of control group; and simultaneously lower in dexamethasone group, lidocaine group, omnipaque group respectively; P value was also <0.05 or 0.01. Conclusion: Dexamethasone, lidocaine and omnipaque can individually inhibit the activity of collagenase at different degrees, so they shouldn't be used together with collagenase in treating the lumber disc herniation. (authors)

Synthesis and release of luteinizing hormone in vitro: manipulations of Ca2+ environment

International Nuclear Information System (INIS)

Liu, T.C.; Jackson, G.L.

1985-01-01

The authors determined if luteinizing hormone (LH) synthesis is Ca2+ dependent and coupled to LH release. They monitored LH synthesis when LH release was stimulated either by specific [gonadotropin-releasing hormone (GnRH)] or nonspecific stimuli (50 mM K+ and 2 or 20 microM Ca2+ ionophore A23187) and inhibited by Ca2+-reduced medium. LH synthesis was estimated by measuring incorporation of [ 3 H]glucosamine (glycosylation) and [ 14 C]alanine (translation) into total (cell and medium) immunoprecipitable LH by cultured rat anterior pituitary cells. Both GnRH (1 nM) and 50 mM K+ significantly stimulated LH release and glycosylation, but had no effect on LH translation. A23187 also stimulated LH release, but significantly depressed glycosylation of LH and total protein and [ 14 C]alanine uptake. Deletion of Ca2+ from the medium depressed both GnRH-induced LH release and glycosylation. Addition of 0.1 mM EGTA to Ca2+-free medium not only inhibited GnRH-induced release and glycosylation of LH but also uptake of precursors and glycosylation and translation of total protein. Thus, glycosylation and release of LH are Ca2+ dependent. Whether parallel changes in LH release and glycosylation reflect a cause and effect relationship remains to be determined

Impact of dexamethason

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Zahra Basirat

2016-09-01

Full Text Available Objective: Infertile women with polycystic ovary (PCOs involve with anovulatory cycles. Various adjuvant treatments have been suggested to improve ovarian response in these patients. In this study, we aimed to evaluate the role of dexamethasone in the outcome of IVF/ICSI in PCOs infertile women. Study design: 129 PCOs infertile women undergone IVF/ICSI were enrolled for this single blind clinical trial study in 2012–2013. Setting: Fatemezahra Infertility and Reproductive Health Research Center, Babol University of Medical Sciences, Babol, Iran. Method: 43 patients who underwent IVF received dexamethasone (0.5 mg, 4 tab/day in the treatment group and 74 patients were considered as the placebo group. Main outcome measure: Pregnancy rate was compared between the two groups. In addition, number of dominant follicle, oocytes retrieved, embryos transferred, and number of gonadotropin ampoule were evaluated. Results: The pregnancy rate in the group receiving dexamethasone was 17.5% significantly higher versus 4.3% in the placebo group (P < 0.05. The mean number of embryos in the patients received dexamethasone was 6.7 ± 4.3, significantly greater than placebo which was 4.9 ± 4.9 (P < 0.05. The mean number of gonadotropin ampoules used in the group received dexamethasone was 3.5 ± 1.6, significantly lower versus the placebo which was 5.3 ± 2.5 (P < 0.05. The mean number of oocytes in the group received dexamethasone was 11.8 ± 8 and in the placebo group was 9.6 ± 5.8 that was not significant. Conclusion: Dexamethasone enhances embryos and pregnancy rate; in addition, it reduces gonadotropines ampoule used for stimulation, hence, and we recommend using of dexamethasone in women with PCOs undertreatment of IVF/ICSI.

Kisspeptin stimulates growth hormone release by utilizing Neuropeptide Y pathways and is dependent on the presence of ghrelin

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Although kisspeptin is the primary stimulator of gonadotropin releasing hormone secretion and therefore the hypothalamic-pituitary gonadal axis, new findings suggest kisspeptin can also regulate additional neuroendocrine processes including release of growth hormone (GH). Central delivery of kisspep...

Childhood lead toxicity and impaired release of thyrotropin-stimulating hormone

International Nuclear Information System (INIS)

Huseman, C.A.; Moriarty, C.M.; Angle, C.R.

1987-01-01

Decreased stature of children is epidemiologically associated with increased blood lead independent of multiple socioeconomic and nutritional variables. Since endocrine dysfunction occurs in adult lead workers, they studied two girls, 2 years of age, before and after calcium disodium edetate chelation for blood leads (PbB) of 19-72 μg/dl. The height of both children had crossed from the 50th to below the 10th percentile during the course of chronic lead toxicity. Basal free T 4 , T 4 , T 3 , cortisol, somatomedin C, and sex steroids were normal. A decrease in the growth hormone response and elevation of basal prolcatin and gonadotropins were noted in one. Both children demonstrated blunted thyrotropin-stimulating hormone (TSH) responses to thyrotropin-releasing hormone (TRH) in six of seven challenges. This prompted in vitro studies of cultured cells from rat pituitarities. After incubation of pituitary cells with 0.1-10 μM Pb 2+ for 2 hr, followed by the addition of TRH, there was a dose-dependent inhibition of TSH release Lead did not interfere with the assay of TSH. To investigate the interaction of lead and calcium, 45 Ca 2+ kinetic analyses were done on rat pituitary slices after 1 hr incubation with 1.0 μM lead. The impaired late efflux was consistent with a decrease in the size and exchangeability of the tightly bound pool of intracellular microsomal or mitochondrial calcium. The rat pituitary cell model provides a model for the decreased TSH release of lead poisoning, supports the biological plausibility of a neuroendocrine effect on growth, and suggests that interference with calcium-mediated intracellular responses is a basic mechanism of lead toxicity

Regulation of gonadotropin-releasing hormone neurons by glucose

Science.gov (United States)

Roland, Alison V.; Moenter, Suzanne M.

2011-01-01

Reproduction is influenced by energy balance, but the physiological pathways mediating their relationship have not been fully elucidated. As the central regulators of fertility, gonadotropin-releasing hormone (GnRH) neurons integrate numerous physiological signals, including metabolic cues. Circulating glucose levels regulate GnRH release and may in part mediate the effects of negative energy balance on fertility. Existing evidence suggests that neural pathways originating in the hindbrain, as well as in the hypothalamic feeding nuclei, transmit information concerning glucose availability to GnRH neurons. Here we review recent evidence suggesting that GnRH neurons may directly sense changes in glucose availability by a mechanism involving adenosine monophosphate-activated protein kinase (AMPK). These findings expand our understanding of how metabolic signaling in the brain regulates reproduction. PMID:21855365

Corticotropin-releasing hormone induces depression-like changes of sleep electroencephalogram in healthy women.

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Schüssler, P; Kluge, M; Gamringer, W; Wetter, T C; Yassouridis, A; Uhr, M; Rupprecht, R; Steiger, A

2016-12-01

We reported previously that repetitive intravenous injections of corticotropin-releasing hormone (CRH) around sleep onset prompt depression-like changes in certain sleep and endocrine activity parameters (e.g. decrease of slow-wave sleep during the second half of the night, blunted growth hormone peak, elevated cortisol concentration during the first half of the night). Furthermore a sexual dimorphism of the sleep-endocrine effects of the hormones growth hormone-releasing hormone and ghrelin was observed. In the present placebo-controlled study we investigated the effect of pulsatile administration of 4×50μg CRH on sleep electroencephalogram (EEG) and nocturnal cortisol and GH concentration in young healthy women. After CRH compared to placebo, intermittent wakefulness increased during the total night and the sleep efficiency index decreased. During the first third of the night, REM sleep and stage 2 sleep increased and sleep stage 3 decreased. Cortisol concentration was elevated throughout the night and during the first and second third of the night. GH secretion remained unchanged. Our data suggest that after CRH some sleep and endocrine activity parameters show also depression-like changes in healthy women. These changes are more distinct in women than in men. Copyright © 2016 Elsevier Ltd. All rights reserved.

Consensus statement on the use of gonadotropin-releasing hormone analogs in children

DEFF Research Database (Denmark)

Carel, Jean-Claude; Eugster, Erica A; Rogol, Alan

2009-01-01

, an equal male/female ratio, and a balanced spectrum of professional seniority and expertise. EVIDENCE: Preference was given to articles written in English with long-term outcome data. The US Public Health grading system was used to grade evidence and rate the strength of conclusions. When evidence......OBJECTIVE: Gonadotropin-releasing hormone analogs revolutionized the treatment of central precocious puberty. However, questions remain regarding their optimal use in central precocious puberty and other conditions. The Lawson Wilkins Pediatric Endocrine Society and the European Society...... for Pediatric Endocrinology convened a consensus conference to review the clinical use of gonadotropin-releasing hormone analogs in children and adolescents. PARTICIPANTS: When selecting the 30 participants, consideration was given to equal representation from North America (United States and Canada) and Europe...

Effect of priming injections of luteinizing hormone-releasing hormone on spermiation and ovulation in Gϋnther's Toadlet, Pseudophryne guentheri

Directory of Open Access Journals (Sweden)

Silla Aimee J

2011-05-01

Full Text Available Abstract Background In the majority of vertebrates, gametogenesis and gamete-release depend on the pulsatile secretion of luteinizing hormone-releasing hormone (LHRH from the hypothalamus. Studies attempting to artificially stimulate ovulation and spermiation may benefit from mimicking the naturally episodic secretion of LHRH by administering priming injections of a synthetic analogue (LHRHa. This study investigated the impact of low-dose priming injections of LHRHa on gamete-release in the Australian toadlet Pseudophryne guentheri. Methods Toadlets were administered a single dose of two micrograms per. gram LHRHa without a priming injection (no priming, or preceded by one (one priming or two (two priming injections of 0.4 micrograms per. gram LHRHa. Spermiation responses were evaluated at 3, 7 and 12 hrs post hormone administration (PA, and sperm number and viability were quantified using fluorescent microscopy. Oocyte yields were evaluated by stripping females at 10-11 hrs PA. A sub-sample of twenty eggs per female was then fertilised (with sperm obtained from testis macerates and fertilisation success determined. Results No priming induced the release of the highest number of spermatozoa, with a step-wise decrease in the number of spermatozoa released in the one and two priming treatments respectively. Peak sperm-release occurred at 12 hrs PA for all priming treatments and there was no significant difference in sperm viability. Females in the control treatment failed to release oocytes, while those administered an ovulatory dose without priming exhibited a poor ovulatory response. The remaining two priming treatments (one and two priming successfully induced 100% of females to expel an entire clutch. Oocytes obtained from the no, or two priming treatments all failed to fertilise, however oocytes obtained from the one priming treatment displayed an average fertilisation success of 97%. Conclusion Spermiation was most effectively induced in

Addition of sucralose enhances the release of satiety hormones in combination with pea protein.

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Geraedts, Maartje C P; Troost, Freddy J; Saris, Wim H M

2012-03-01

Exposing the intestine to proteins or tastants, particularly sweet, affects satiety hormone release. There are indications that each sweetener has different effects on this release, and that combining sweeteners with other nutrients might exert synergistic effects on hormone release. STC-1 cells were incubated with acesulfame-K, aspartame, saccharine, sucralose, sucrose, pea, and pea with each sweetener. After a 2-h incubation period, cholecystokinin(CCK) and glucagon-like peptide 1 (GLP-1) concentrations were measured. Using Ussing chamber technology, the mucosal side of human duodenal biopsies was exposed to sucrose, sucralose, pea, and pea with each sweetener. CCK and GLP-1 levels were measured in basolateral secretions. In STC-1 cells, exposure to aspartame, sucralose, sucrose, pea, and pea with sucralose increased CCK levels, whereas GLP-1 levels increased after addition of all test products. Addition of sucrose and sucralose to human duodenal biopsies did not affect CCK and GLP-1 release; addition of pea stimulated CCK and GLP-1 secretion. Combining pea with sucrose and sucralose induced even higher levels of CCK and GLP-1. Synchronous addition of pea and sucralose to enteroendocrine cells induced higher levels of CCK and GLP-1 than addition of each compound alone. This study shows that combinations of dietary compounds synergize to enhance satiety hormone release. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Simultaneous measurement of hormone release and secretagogue binding by individual pituitary cells

International Nuclear Information System (INIS)

Smith, P.F.; Neill, J.D.

1987-01-01

The quantitative relationship between receptor binding and hormone secretion at the single-cell level was investigated in the present study by combining a reverse hemolytic plaque assay for measurement of luteinizing hormone (LH) secretion from individual pituitary cells with an autoradiographic assay of 125 I-labeled gonadontropin-releasing hormone (GnRH) agonist binding to the same cells. In the plaque assay, LH secretion induces complement-mediated lysis of the LH-antibody-coated erythrocytes around the gonadotropes, resulting in areas of lysis (plaques). LH release from individual gonadotropes was quantified by comparing radioimmunoassayable LH release to hemolytic area in similarly treated cohort groups of cells; plaque area was linearly related to the amount of LH secreted. Receptor autoradiography was performed using 125 I-labeled GnRH-A (a superagonist analog of GnRH) both as the ligand and as the stimulant for LH release in the plaque assay. The grains appeared to represent specific and high-affinity receptors for GnRH because (i) no pituitary cells other than gonadotropes bound the labeled ligand and (ii) grain development was progressively inhibited by coincubation with increasing doses of unlabeled GnRH-A. The authors conclude that GnRH receptor number for any individual gonadotrope is a weak determinant of the amount of LH it can secrete; nevertheless, full occupancy of all its GnRH receptors is required for any gonadotrope to reach its full LH-secretory capacity. Apparently the levels of other factors comprising the steps along the secretory pathway determine the secretory capacity of an individual cell

The Dwarfs of Sindh: severe growth hormone (GH) deficiency caused by a mutation in the GH-releasing hormone receptor gene.

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Baumann, G; Maheshwari, H

1997-11-01

We report the discovery of a cluster of severe familial dwarfism in two villages in the Province of Sindh in Pakistan. Dwarfism is proportionate and occurs in members of a kindred with a high degree of consanguinity. Only the last generation is affected, with the oldest dwarf being 28 years old. The mode of inheritance is autosomal recessive. Phenotype analysis and endocrine testing revealed isolated growth hormone deficiency (GHD) as the reason for growth failure. Linkage analysis for the loci of several candidate genes yielded a high lod score for the growth hormone-releasing hormone receptor (GHRH-R) locus on chromosome 7. Amplification and sequencing of the GHRH-R gene in affected subjects demonstrated an amber nonsense mutation (GAG-->TAG; Glu50-->Stop) in exon 3. The mutation, in its homozygous form, segregated 100% with the dwarf phenotype. It predicts a truncation of the GHRH-R in its extracellular domain, which is likely to result in a severely disabled or non-existent receptor protein. Subjects who are heterozygous for the mutation show mild biochemical abnormalities in the growth hormone-releasing hormone (GHRH)--growth hormone--insulin-like growth factor axis, but have only minimal or no growth retardation. The occurrence of an offspring of two dwarfed parents indicates that the GHRH-R is not necessary for fertility in either sex. We conclude that Sindh dwarfism is caused by an inactivating mutation in the GHRH-R gene, resulting in the inability to transmit a GHRH signal and consequent severe isolated GHD.

Analogues of luteinizing hormone-releasing hormone containing cytotoxic groups.

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Janáky, T; Juhász, A; Bajusz, S; Csernus, V; Srkalovic, G; Bokser, L; Milovanovic, S; Redding, T W; Rékási, Z; Nagy, A

1992-02-01

In an attempt to produce better cytotoxic analogues, chemotherapeutic antineoplastic radicals including an alkylating nitrogen mustard derivative of D-phenylalanine (D-melphalan), reactive cyclopropane, anthraquinone derivatives [2-(hydroxymethyl)anthraquinone and the anticancer antibiotic doxorubicin], and an antimetabolite (methotrexate) were coupled to suitably modified agonists and antagonists of luteinizing hormone-releasing hormone (LH-RH). Analogues with D-lysine6 and D-ornithine6 or N epsilon-(2,3-diaminopropionyl)-D-lysine and N delta-(2,3-diaminopropionyl)-D-ornithine were used as carriers for one or two cytotoxic moieties. The enhanced biological activities produced by the incorporation of D amino acids into position 6 of the agonistic analogues were further increased by the attachment of hydrophobic cytotoxic groups, resulting in compounds with 10-50 times higher activity than LH-RH. Most of the monosubstituted agonistic analogues showed high affinities for the membrane receptors of human breast cancer cells, while the receptor binding affinities of peptides containing two cytotoxic side chains were lower. Antagonistic carriers [Ac-D-Nal(2)1,D-Phe(4Cl)2,D-Trp3,Arg5,D-Lys6,D-Ala10] LH-RH [where Nal(2) is 3-(2-naphthyl)alanine], [Ac-D-Nal(2)1,D-Phe(4Cl)2,D-Trp3,Arg5,N epsilon-(2,3-diaminopropionyl)-D-Lys6,D-Ala10]LH-RH, and their D-Pal(3)3 homologs [Pal(3) is 3-(3-pyridyl)alanine] as well as [Ac-D-Nal(2)1,D-Phe(4Cl)2,D-Pal(3)3,Tyr5,N epsilon-(2,3-diamino-propionyl)-D-Lys6,D-Ala10]LH-RH were linked to cytotoxic compounds. The hybrid molecules inhibited ovulation in rats at doses of 10 micrograms and suppressed LH release in vitro. The receptor binding of cytotoxic analogues was decreased compared to the precursor peptides, although analogues with 2-(hydroxymethyl)anthraquinone hemiglutarate had high affinities. All of the cytotoxic analogues tested inhibited [3H]thymidine incorporation into DNA in cultures of human breast and prostate cancer cell lines

Dexamethasone PONV prophylaxis alters the hypothalamic-pituitary-adrenal axis after transsphenoidal pituitary surgery.

Science.gov (United States)

Burkhardt, Till; Rotermund, Roman; Schmidt, Nils-Ole; Kiefmann, Rainer; Flitsch, Jörg

2014-07-01

Postoperative nausea and vomiting (PONV) is common after general anesthesia and are reported by approximately 20% to 25% of all patients and up to 39% of patients undergoing neurosurgical procedures. The most common standard prophylaxis is a single application of 4 mg of dexamethasone before initiating anesthesia. Dexamethasone is known to suppress adreno-corticotroph hormone and cortisol levels. The objective was to find out whether this prophylaxis has an effect on the postoperative levels of cortisol in patients undergoing transsphenoidal pituitary surgery, and therefore simulates pituitary deficiency. A retrospective analysis of the files of 136 consecutive patients who were operated during a course of 6 months were included. Nineteen patients with a known history of PONV received a standard dose of 4 mg of dexamethasone perioperatively. Blood tests were drawn at the first postoperative day and were compared with blood tests of patients who had no history of PONV and therefore received no prophylaxis. Patients who were treated with a dexamethasone PONV prophylaxis showed no significant changes in cortisol levels; preoperative median of 93 μg/L (range, 39 to 427) and a postoperative median of 87 μg/L (range, 10 to 733; P=0.798) opposed to patients who did not receive such treatment; preoperative cortisol 114 μg/L (range, 10 to 387) and postoperative levels of 273 μg/L (range, 10 to 1352; Ptranssphenoidal surgery, the probability that dexamethasone PONV prophylaxis suppresses postoperative cortisol levels should be considered.

Growth hormone-releasing peptides.

Science.gov (United States)

Ghigo, E; Arvat, E; Muccioli, G; Camanni, F

1997-05-01

Growth hormone-releasing peptides (GHRPs) are synthetic, non-natural peptides endowed with potent stimulatory effects on somatotrope secretion in animals and humans. They have no structural homology with GHRH and act via specific receptors present either at the pituitary or the hypothalamic level both in animals and in humans. The GHRP receptor has recently been cloned and, interestingly, it does not show sequence homology with other G-protein-coupled receptors known so far. This evidence strongly suggests the existence of a natural GHRP-like ligand which, however, has not yet been found. The mechanisms underlying the GHRP effect are still unclear. At present, several data favor the hypothesis that GHRPs could act by counteracting somatostatinergic activity both at the pituitary and the hypothalamic level and/or, at least partially, via a GHRH-mediated mechanism. However, the possibility that GHRPs act via an unknown hypothalamic factor (U factor) is still open. GHRP-6 was the first hexapeptide to be extensively studied in humans. More recently, a heptapeptide, GHRP-1, and two other hexapeptides, GHRP-2 and Hexarelin, have been synthesized and are now available for human studies. Moreover, non-peptidyl GHRP mimetics have been developed which act via GHRP receptors and their effects have been clearly demonstrated in animals and in humans in vivo. Among non-peptidyl GHRPs, MK-0677 seems the most interesting molecule. The GH-releasing activity of GHRPs is marked and dose-related after intravenous, subcutaneous, intranasal and even oral administration. The effect of GHRPs is reproducible and undergoes partial desensitization, more during continuous infusion, less during intermittent administration: in fact, prolonged administration of GHRPs increases IGF-1 levels both in animals and in humans. The GH-releasing effect of GHRPs does not depend on sex but undergoes age-related variations. It increases from birth to puberty, persists at a similar level in adulthood and

The effect of dexamethasone and triiodothyronine on terminal differentiation of primary bovine chondrocytes and chondrogenically differentiated mesenchymal stem cells.

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Randau, Thomas M; Schildberg, Frank A; Alini, Mauro; Wimmer, Matthias D; Haddouti, El-Mustapha; Gravius, Sascha; Ito, Keita; Stoddart, Martin J

2013-01-01

The newly evolved field of regenerative medicine is offering solutions in the treatment of bone or cartilage loss and deficiency. Mesenchymal stem cells, as well as articular chondrocytes, are potential cells for the generation of bone or cartilage. The natural mechanism of bone formation is that of endochondral ossification, regulated, among other factors, through the hormones dexamethasone and triiodothyronine. We investigated the effects of these hormones on articular chondrocytes and chondrogenically differentiated mesenchymal stem cells, hypothesizing that these hormones would induce terminal differentiation, with chondrocytes and differentiated stem cells being similar in their response. Using a 3D-alginate cell culture model, bovine chondrocytes and chondrogenically differentiated stem cells were cultured in presence of triiodothyronine or dexamethasone, and cell proliferation and extracellular matrix production were investigated. Collagen mRNA expression was measured by real-time PCR. Col X mRNA and alkaline phosphatase were monitored as markers of terminal differentiation, a prerequisite of endochondral ossification. The alginate culture system worked well, both for the culture of chondrocytes and for the chondrogenic differentiation of mesenchymal stem cells. Dexamethasone led to an increase in glycosaminoglycan production. Triiodothyronine increased the total collagen production only in chondrocytes, where it also induced signs of terminal differentiation, increasing both collagen X mRNA and alkaline phosphatase activity. Dexamethasone induced terminal differentiation in the differentiated stem cells. The immature articular chondrocytes used in this study seem to be able to undergo terminal differentiation, pointing to their possible role in the onset of degenerative osteoarthritis, as well as their potential for a cell source in bone tissue engineering. When chondrocyte-like cells, after their differentiation, can indeed be moved on towards terminal

Hormonal induction of gamete release, and in-vitro fertilisation, in the critically endangered Southern Corroboree Frog, Pseudophryne corroboree

Directory of Open Access Journals (Sweden)

Silla Aimee J

2010-11-01

Full Text Available Abstract Background Conservation Breeding Programs (CBP's are playing an important role in the protection of critically endangered anuran amphibians, but for many species recruitment is not successful enough to maintain captive populations, or provide individuals for release. In response, there has been an increasing focus on the use of Assisted Reproductive Technologies (ART, including the administration of reproductive hormones to induce gamete release followed by in vitro fertilisation. The objective of this study was to test the efficacy of two exogenous hormones to induce gamete release, for the purpose of conducting in vitro fertilisation (IVF, in one of Australia's most critically endangered frog species, Pseudophryne corroboree. Methods Male frogs were administered a single dose of either human chorionic gonadotropin (hCG or luteinizing hormone-releasing hormone (LHRHa, while female frogs received both a priming and ovulatory dose of LHRHa. Spermiation responses were evaluated at 3, 7, 12, 24, 36, 48, 60 and 72 h post hormone administration (PA, and sperm number and viability were quantified using fluorescent microscopy. Ovulation responses were evaluated by stripping females every 12 h PA for 5 days. Once gametes were obtained, IVF was attempted by combining spermic urine with oocytes in a dilute solution of simplified amphibian ringer (SAR. Results Administration of both hCG and LHRHa induced approximately 80% of males to release sperm over 72 h. Peak sperm release occurred at 12 h PA for hCG treated males and 36 h PA for LHRHa treated males. On average, LHRHa treated males released a significantly higher total number of live sperm, and a higher concentration of sperm, over a longer period. In female frogs, administration of LHRHa induced approximately 30% of individuals to release eggs. On average, eggs were released between 24 and 48 h PA, with a peak in egg release at 36 h PA. IVF resulted in a moderate percentage (54.72% of eggs

The effect of ovarian steroid feedback upon radioimmunoreactive luteinizing hormone releasing hormone in the hypothalamus

International Nuclear Information System (INIS)

Yanaihara, Takumi; Arai, Kiyoshi; Kanazawa, Motomi; Okinaga, Shoichi; Yanaihara, Noboru

1975-01-01

A radioimmunoassay (RIA) method for luteinizing hormone (LH) releasing hormone (RH) utilizing rabbit antiserum against synthetic (Glu 1 )-LH-RH coupled with human serum albumin at the N-terminus, is described. This assay system for LH-RH also cross-reacted with several LH-RH analogues or fragments, but not with pituitary trophic hormones. The assay was performed on the hypothalamic extracts of adult ovariectomized rats and female immature rats which had been treated with estradiol. The FSH and LH levels in the pituitary gland and serum of the same animals were determined by RIA. The radioimmunoreactive LH-RH content of the stalk median eminence markedly increased seven days after ovariectomy. The serum levels and the pituitary contents of FSH and LH of the same rats were also significantly augmented. In immature rats, the hypothalamic content of LH-RH, as measured by RIA, was significantly increased one hour after the injection of estradiol. The FSH and LH levels in the pituitary showed a significant rise after 7 hours. (auth.)

Towards more physiological manipulations of hormones in field studies: comparing the release dynamics of three kinds of testosterone implants, silastic tubing, time-release pellets and beeswax.

Science.gov (United States)

Quispe, Rene; Trappschuh, Monika; Gahr, Manfred; Goymann, Wolfgang

2015-02-01

Hormone manipulations are of increasing interest in the areas of physiological ecology and evolution, because hormones are mediators of complex phenotypic changes. Often, however, hormone manipulations in field settings follow the approaches that have been used in classical endocrinology, potentially using supra-physiological doses. To answer ecological and evolutionary questions, it may be important to manipulate hormones within their physiological range. We compare the release dynamics of three kinds of implants, silastic tubing, time-release pellets, and beeswax pellets, each containing 3mg of testosterone. These implants were placed into female Japanese quail, and plasma levels of testosterone measured over a period of 30 days. Testosterone in silastic tubing led to supraphysiological levels. Also, testosterone concentrations were highly variable between individuals. Time-release pellets led to levels of testosterone that were slightly supraphysiological during the first days. Over the period of 30 days, however, testosterone concentrations were more consistent. Beeswax implants led to a physiological increase in testosterone and a relatively constant release. The study demonstrated that hormone implants in 10mm silastic tubing led to a supraphysiological peak in female quail. Thus, the use of similar-sized or even larger silastic implants in males or in other smaller vertebrates needs careful assessment. Time-release pellets and beeswax implants provide a more controlled release and degrade within the body. Thus, it is not necessary to recapture the animal to remove the implant. We propose beeswax implants as an appropriate procedure to manipulate testosterone levels within the physiological range. Hence, such implants may be an effective alternative for field studies. Copyright © 2015 Elsevier Inc. All rights reserved.

GH response to intravenous clonidine challenge correlates with history of childhood trauma in personality disorder.

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Lee, Royce J; Fanning, Jennifer R; Coccaro, Emil F

2016-05-01

Childhood trauma is a risk factor for personality disorder. We have previously shown that childhood trauma is associated with increased central corticotrophin-releasing hormone concentration in adults with personality disorder. In the brain, the release of corticotrophin-releasing hormone can be stimulated by noradrenergic neuronal activity, raising the possibility that childhood trauma may affect the hypothalamic-pituitary adrenal (HPA) axis by altering brain noradrenergic function. In this study, we sought to test the hypothesis that childhood trauma is associated with blunted growth hormone response to the α-2 adrenergic autoreceptor agonist clonidine. All subjects provided written informed consent. Twenty personality disordered and twenty healthy controls (without personality disorder or Axis I psychopathology) underwent challenge with clonidine, while plasma Growth Hormone (GH) concentration was monitored by intravenous catheter. On a different study session, subjects completed the Childhood Trauma Questionnaire and underwent diagnostic interviews. Contrary to our a priori hypothesis, childhood trauma was associated with enhanced GH response to clonidine. This positive relationship was present in the group of 40 subjects and in the subgroup 20 personality disordered subjects, but was not detected in the healthy control subjects when analyzed separately. The presence of personality disorder was unrelated to the magnitude of GH response. Childhood trauma is positively correlated with GH response to clonidine challenge in adults with personality disorder. Enhanced rather that blunted GH response differentiates childhood trauma from previously identified negative predictors of GH response, such as anxiety or mood disorder. Copyright © 2016 Elsevier Ltd. All rights reserved.

Short-chain analogs of luteinizing hormone-releasing hormone containing cytotoxic moieties.

Science.gov (United States)

Janáky, T; Juhász, A; Rékási, Z; Serfözö, P; Pinski, J; Bokser, L; Srkalovic, G; Milovanovic, S; Redding, T W; Halmos, G

1992-11-01

Five hexapeptide and heptapeptide analogs of luteinizing hormone-releasing hormone (LH-RH) were synthesized for use as carriers for cytotoxic compounds. These short analogs were expected to enhance target selectivity of the antineoplastic agents linked to them. Native LH-RH-(3-9) and LH-RH-(4-9) containing D-lysine and D-ornithine at position 6 were amidated with ethylamine and acylated on the N terminus. The receptor-binding affinity of one hexapeptide carrier AJ-41 (Ac-Ser-Tyr-D-Lys-Leu-Arg-Pro-NH-Et) to human breast cancer cell membranes was similar to that of [D-Trp6]LH-RH. Alkylating nitrogen mustards (melphalan, Ac-melphalan), anthraquinone derivatives including anticancer antibiotic doxorubicin, antimetabolite (methotrexate), and cisplatin-like platinum complex were linked to these peptides through their omega-amino group at position 6. The hybrid molecules showed no LH-RH agonistic activity in vitro and in vivo but had nontypical antagonistic effects on pituitary cells in vitro at the doses tested. These analogs showed a wide range of receptor-binding affinities to rat pituitaries and cell membranes of human breast cancer and rat Dunning prostate cancer. Several of these conjugates exerted some cytotoxic effects on MCF-7 breast cancer cell line.

Evaluating the patient experience after implantation of a 0.4 mg sustained release dexamethasone intracanalicular insert (Dextenza™): results of a qualitative survey.

Science.gov (United States)

Gira, Joseph P; Sampson, Reginald; Silverstein, Steven M; Walters, Thomas R; Metzinger, Jamie Lynne; Talamo, Jonathan H

2017-01-01

The purpose of this study is to evaluate the patient experience of sustained release dexamethasone intracanalicular insert (Dextenza™) following cataract surgery as part of a Phase III clinical trial program. This cross-sectional, qualitative evaluation involved individual interviews lasting approximately 45 minutes. Patients from four US investigational study sites who had previously received an insert were enrolled. There were no predesignated end points; this was a qualitative survey seeking a deeper understanding of patient experience. Twenty-five patients were interviewed. Most patients (92%) reported the highest level of satisfaction grade with regard to overall product satisfaction. All patients described the insert as comfortable. Most patients (96%) described their overall experience with the insert as very convenient or extremely convenient. Twenty-two of 23 (96%) participants rated their experience with the insert as "very" or "extremely convenient", compared to previous topical therapy, and 88% of patients stated that if they were to undergo cataract surgery again, they would request the insert. When asked if they would recommend the insert to family members or friends, 92% stated they would. The survey found that 84% of participants would be willing to pay more for the insert than for eye drop therapy. The dexamethasone insert was found by patients to be highly favorable with regard to overall satisfaction, convenience, and comfort. The insert was well received and largely preferred over topical therapy alternatives following surgery. More extensive evaluation of the patient experience is warranted, and future studies should help inform design of the next generation of sustained release drug delivery systems.

Association of plasma hormones, nutritional status, and stressful life events in anorexia nervosa patients.

Science.gov (United States)

Śmiarowska, Małgorzata; Safranow, Krzysztof; Dziedziejko, Violetta; Bialecka, Monika; Koziołek, Monika; Samochowiec, Jerzy

2014-02-06

The aim of the current study was to analyze the relationships between plasma hormones, body weight parameters and stressful life events in anorexia nervosa (AN). 72 females in the active phase of AN were evaluated. 52 healthy women constituted the control group. RIA kits were used to measure plasma hormone levels. The concentrations of leptin, insulin, IGF-1, triiodothyronine, LH, FSH, estradiol, and testosterone were significantly lower and those of cortisol and growth hormone significantly higher in the AN than the control group. No hormonal differences between restrictive and binge-purging AN subtypes were found. Leptin, IGF-1, gonadotropins, and sex steroids correlated significantly negatively and growth hormone positively with total reduction of body weight or the degree of undernutrition. Associations were also found between lower insulin concentration and family violence, lower cortisol and psychiatric diseases in the family, higher testosterone and patient's alcohol or drug abuse. The changed activity of the somatotropin-somatomedin, gonadal, and corticotrophin axes corresponds to the clinical stage of AN. Plasma IGF-1 seems to be the most sensitive and useful independent hormonal marker of cachexia.

Increased pituitary-adrenal activation and shortened gestation in a sample of depressed pregnant women: a pilot study.

LENUS (Irish Health Repository)

O'Keane, V

2011-04-01

Major depression (MD) is frequently accompanied by a relatively increased production of the stress hormone cortisol. During pregnancy corticotrophin releasing hormone (CRH) is secreted from the placenta and critically high levels of CRH are one of the key triggers for parturition. Maternal cortisol promotes the secretion of placental CRH. In this study, we examined the hypothesis that women suffering with MD in pregnancy would have relatively increased cortisol secretion, a time-advanced rise in placental CRH production and an earlier delivery of the baby.

Nervus terminalis, olfactory nerve, and optic nerve representation of luteinizing hormone-releasing hormone in primates.

Science.gov (United States)

Witkin, J W

1987-01-01

The luteinizing hormone-releasing hormone (LHRH) system was examined immunocytochemically in olfactory bulbs of adult monkeys, including two New World species (squirrel monkey, Saimiri sciureus and owl monkey, Aotus trivirgatus) and one Old World species (cynomolgus macaque, Macaca fasciculata), and in the brain and nasal region of a fetal rhesus macaque Macaca mulatta. LHRH neurons and fibers were found sparsely distributed in the olfactory bulbs in all adult monkeys. There was more LHRH in the accessory olfactory bulb (which is absent in Old World monkeys). In the fetal macaque there was a rich distribution of LHRH neurons and fibers along the pathway of the nervus terminalis, anterior and ventral to the olfactory bulb, and in the nasal septum, with fibers branching into the olfactory epithelium. In addition, there were LHRH neurons and fibers in the optic nerve.

Glucocorticoid receptors on leukemic cells as evidenced by dexamethasone-induced cytolysis and /sup 3/H-dexamethasone binding

Energy Technology Data Exchange (ETDEWEB)

Thraenhardt, H; Haefer, R; Zintl, F

1987-01-01

The presence of glucocorticoid receptors on the leukemic cells of 33 patients affected with acute lymphatic leukemia (ALL) and 6 patients affected with acute myeloic leukemia (AML) was investigated by dexamethasone-induced cytolysis and (/sup 3/H)-dexamethasone binding. The tests undertaken proved that after 20 hours of incubation 9 of 26 non-T-non-B-ALL (c-ALL and unclassified ALL) and 2 of AML were lysed with dexamethasone; blood lymphocytes and bone marrow leukocytes of healthy donors, however, were not affected. Non-T-non-B-ALL and AML were able to bind essentially more (/sup 3/H)-dexamethasone than T-ALL. There existed no correlation between dexamethasone binding and dexamethasone-induced cytolysis.

Effects of awakening and the use of topical dexamethasone and levofloxacin on the cytokine levels in tears following corneal transplantation.

Science.gov (United States)

Fodor, Mariann; Petrovski, Goran; Pásztor, Dorottya; Gogolák, Péter; Rajnavölgyi, Éva; Berta, András

2014-01-01

To study the short-term effect of eye opening and use of topical dexamethasone phosphate 0.1% and levofloxacin 0.5% on the cytokine levels in human tears. Prospective experimental design was used for tear collection from eyes of 10 healthy controls and 20 patients four days after penetrating keratoplasty (PKP) at awakening and after instilling dexamethasone or levofloxacin. The concentrations of different cytokines were measured by cytometric bead array. At eye opening, IL-6 levels were higher in the PKP group as compared to the controls. Thirty minutes later, the released levels of IL-10, IL-13, IL-17, IFNγ, and CCL5 increased in controls, while CXCL8 decreased in both control and PKP groups. The release of the cytokines remained stable after 30 mins except for IFNγ, which showed a decrease in the controls following levofloxacin instillation. No short-term effects of the topically used dexamethasone and levofloxacin could be detected on the cytokine levels in controls and after PKP. Evidence of changes in the levels and time course of tear cytokines after awakening or eye opening could be established and the short-term confounding effects of dexamethasone and levofloxacin on the levels of released cytokines in human tears could be excluded.

Salmonella Typhi sense host neuroendocrine stress hormones and release the toxin haemolysin E

Science.gov (United States)

Karavolos, Michail H; Bulmer, David M; Spencer, Hannah; Rampioni, Giordano; Schmalen, Ira; Baker, Stephen; Pickard, Derek; Gray, Joe; Fookes, Maria; Winzer, Klaus; Ivens, Alasdair; Dougan, Gordon; Williams, Paul; Khan, C M Anjam

2011-01-01

Salmonella enterica serovar Typhi (S. typhi) causes typhoid fever. We show that exposure of S. typhi to neuroendocrine stress hormones results in haemolysis, which is associated with the release of haemolysin E in membrane vesicles. This effect is attributed to increased expression of the small RNA micA and RNA chaperone Hfq, with concomitant downregulation of outer membrane protein A. Deletion of micA or the two-component signal-transduction system, CpxAR, abolishes the phenotype. The hormone response is inhibited by the β-blocker propranolol. We provide mechanistic insights into the basis of neuroendocrine hormone-mediated haemolysis by S. typhi, increasing our understanding of inter-kingdom signalling. PMID:21331094

Solvent-free biodegradable scleral plugs providing sustained release of vancomycin, amikacin, and dexamethasone--an in vivo study.

Science.gov (United States)

Peng, Yi-Jie; Kau, Yi-Chuan; Wen, Chin-Wei; Liu, Kuo-Sheng; Liu, Shih-Jung

2010-08-01

Delivering effective drugs at sufficiently high concentrations to the area of infection is a standard treatment for infectious disease, such as endophthalmitis. This is currently done by empirical trans pars plana intravitreal injection of both antibiotics directed against gram-positive and gram-negative microorganisms and steroids. However, injections by needles repeatedly may increase the risks of intraocular infection and hemorrhage, as well as retinal detachment. This article explores the alternative of using biodegradable polymers as scleral plugs for a long-term drug release in vivo. To manufacture plugs, poly(lactide-glycolide) copolymers were first mixed with vancomycin, amikacin, and dexamethasone. The mixture was compressed and sintered at 55 degrees C to form scleral plugs 1.4 mm in diameter. Biodegradable scleral plugs released high concentrations of antibiotics (well above the minimum inhibitory concentrations, MIC) and steroids in vivo for the period of time needed to treat intraocular infection. In addition, no major complications such as infectious or sterile endophthalmitis, retinal detachment, ocular phthisis, or uvea protrusion at sclerotomy site were observed throughout the experiment. The sclerotomy wound healed after total degradation of the scleral implants without leakage or local necrosis. Antibiotic/steroid-impregnated biodegradable scleral plugs may have a potential role in the treatment of various intraocular infections. (c) 2010 Wiley Periodicals, Inc.

Glucocorticoid stimulates expression of corticotropin-releasing hormone gene in human placenta

International Nuclear Information System (INIS)

Robinson, B.G.; Emanuel, R.L.; Frim, D.M.; Majzoub, J.A.

1988-01-01

Primary cultures of purified human cytotrophoblasts have been used to examine the expression of the corticotropin-releasing hormone (CRH) gene in placenta. The authors report here that glucocorticoids stimulate placental CRH synthesis and secretion in primary cultures of human placenta. This stimulation is in contrast to the glucocorticoid suppression of CRH expression in hypothalamus. The positive regulation of CRH by glucocorticoids suggests that the rise in CRH preceding parturition could result from the previously described rise in fetal glucocorticoids. Furthermore, this increase in placental CRH could stimulate, via adrenocorticotropic hormone, a further rise in fetal glucocorticoids, completing a positive feedback loop that would be terminated by delivery

Effect of Local Vibration and Passive Exercise on the Hormones and Neurotransmitters of Hypothalamic-Pituitary-Adrenal Axis in Hindlimb Unloading Rats

Science.gov (United States)

Luan, Huiqin; Huang, Yunfei; Li, Jian; Sun, Lianwen; Fan, Yubo

2018-04-01

Astronauts are severely affected by spaceflight-induced bone loss. Mechanical stimulation through exercise inhibits bone resorption and improves bone formation. Exercise and vibration can prevent the degeneration of the musculoskeletal system in tail-suspended rats, and long-term exercise stress will affect endocrine and immune systems that are prone to fatigue. However, the mechanisms through which exercise and vibration affect the endocrine system remain unknown. This study mainly aimed to investigate the changes in the contents of endocrine axis-related hormones and the effects of local vibration and passive exercise on hypothalamic-pituitary-adrenal (HPA) axis-related hormones in tail-suspended rats. A total of 32 Sprague-Dawley rats were randomly distributed into four groups (n = 8 per group): tail suspension (TS), TS + 35Hz vibration, TS + passive exercise, and control. The rats were placed on a passive exercise and local vibration regimen for 21 days. On day 22 of the experiment, the contents of corticotrophin-releasing hormone, adrenocorticotropic hormone, cortisol, and 5-hydroxytryptamine in the rats were quantified with kits in accordance with the manufacturer's instructions. Histomorphometry was applied to evaluate histological changes in the hypothalamus. Results showed that 35Hz local vibration cannot cause rats to remain in a stressed state and that it might not inhibit the function of the HPA axis. Therefore, we speculate that this local vibration intensity can protect the function of the HPA axis and helps tail-suspended rats to transition from stressed to adaptive state.

Cushing’s disease and melancholia.

Science.gov (United States)

Condren, R M; Thakore, J H

2001-06-01

Striking similarities exist in the endocrinology of Cushing's disease and melancholic depression.Laboratory abnormalities, which have been found in both, include raised urinary,plasma and salivary cortisol, non-suppression of cortisol in the dexamethasone suppression test and adrenocorticotrophin (ACTH) hypersecretion. The hypercortisolism can be so severe in melancholic depression that it is difficult to distinguish from Cushing's disease and has been described as a "pseudo-Cushing's" state. Cerebrospinal fluid corticotrophin-releasing hormone (CRH) levels have been found to be lower in patients with Cushing's disease than in depressed subjects. Dynamic endocrine tests may help to distinguish between the two disorders.An exaggerated response to synacthen has been found in both but a reduced ACTH response to CRH occurs in depression, unlike those with Cushing's disease who show ACTH hyper-responsiveness. Other tests, which may help to distinguish between the two disorders,include the dexamethasone-CRH test, the naloxone test, the insulin-induced hypoglycemia test and the desmopressin stimulation test. Similarities in psychiatric symptoms have been recognised for many years. More recently, the physical complications of melancholic depression have been noted. These include osteoporosis, an increased risk of death from cardiovascular disease, hypertension, a redistribution of fat to intra abdominal sites and insulin resistance. Cushing's disease shares these physical complications and we propose that the common underlying factor is excessive plasma glucocorticoids. The increasing recognition of the physical complications and the increased morbidity and mortality in those who suffer from depression underscores the necessity for early detection and treatment of this illness and screening for undetected physical complications.

Acute effects of clonidine and growth-hormone-releasing hormone on growth hormone secretion in patients with hyperthyroidism.

Science.gov (United States)

Giustina, A; Buffoli, M G; Bussi, A R; Wehrenberg, W B

1991-01-01

Patients with hyperthyroidism have reduced growth hormone (GH) responses to pharmacological stimuli and reduced spontaneous nocturnal GH secretion. The stimulatory effect of clonidine on GH secretion has been suggested to depend on an enhancement of hypothalamic GH-releasing hormone (GHRH) release. The aim of our study was to evaluate the effects of clonidine and GHRH on GH secretion in patients with hyperthyroidism. Eight hyperthyroid females with recent diagnosis of Graves' disease (age range 20-55 years, body mass index range 19.2-26.2 kg/m2) and 6 healthy female volunteers (age range 22-35 years, body mass index range 19-25 kg/m2) underwent two experimental trials at no less than 7-day intervals: (a) an intravenous infusion of clonidine 150 micrograms in 10 ml of saline, or (b) a bolus intravenous injection of human GHRH (1-29)NH2, 100 micrograms in 1 ml of saline. Hyperthyroid patients showed blunted GH peaks after clonidine (7.1 +/- 1.7 micrograms/l) as compared to normal subjects receiving clonidine (28.5 +/- 4.9 micrograms/l, p less than 0.05). GH peaks after GHRH were also significantly lower in hyperthyroid subjects (8.0 +/- 1.7 micrograms/l) as compared to normal subjects receiving GHRH (27.5 +/- 4.4 micrograms/l, p less than 0.05). No significant differences in the GH values either after clonidine or GHRH were observed in the two groups of subjects examined. Our data demonstrate that the GH responses to clonidine as well as to GHRH in patients with hyperthyroidism are inhibited in a similar fashion with respect to normal subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Review: Regulatory mechanisms of gonadotropin-inhibitory hormone (GnIH synthesis and release in photoperiodic animals

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Kazuyoshi eTsutsui

2013-04-01

Full Text Available Gonadotropin-inhibitory hormone (GnIH is a novel hypothalamic neuropeptide that was discovered in quail as an inhibitory factor for gonadotropin release. GnIH inhibits gonadotropin synthesis and release in birds through actions on gonadotropin-releasing hormone (GnRH neurons and gonadotropes, mediated via the GnIH receptor (GnIH-R, GPR147. Subsequently, GnIH was identified in mammals and other vertebrates. As in birds, mammalian GnIH inhibits gonadotropin secretion, indicating a conserved role for this neuropeptide in the control of the hypothalamic-pituitary-gonadal (HPG axis across species. Identification of the regulatory mechanisms governing GnIH expression and release is important in understanding the physiological role of the GnIH system. A nocturnal hormone, melatonin, appears to act directly on GnIH neurons through its receptor to induce expression and release of GnIH in quail, a photoperiodic bird. Recently, a similar, but opposite, action of melatonin on the inhibition of expression of mammalian GnIH was shown in hamsters and sheep, photoperiodic mammals. These results in photoperiodic animals demonstrate that GnIH expression is photoperiodically modulated via a melatonin-dependent process. Recent findings indicate that GnIH may be a mediator of stress-induced reproductive disruption in birds and mammals, pointing to a broad role for this neuropeptide in assessing physiological state and modifying reproductive effort accordingly. This paper summarizes the advances made in our knowledge regarding the regulation of GnIH synthesis and release in photoperiodic birds and mammals. This paper also discusses the neuroendocrine integration of environmental signals, such as photoperiods and stress, and internal signals, such as GnIH, melatonin and glucocorticoids, to control avian and mammalian reproduction.

Dexamethasone Intravitreal Implant for Diabetic Macular Edema During Pregnancy

DEFF Research Database (Denmark)

Concillado, Michael; Lund-Andersen, Henrik; Mathiesen, Elisabeth R

2016-01-01

PURPOSE: To describe the management of diabetic macular edema during pregnancy with the use of a dexamethasone slow-release intravitreal implant. DESIGN: Retrospective, observational, consecutive case series. METHODS: The study included 5 pregnant women who presented with diabetic macular edema...... injection. RESULTS: Diabetic macular edema involving the foveal center was observed between gestational weeks 9 and 23 in 10 eyes of 5 patients. Dexamethasone intravitreal implant injection was given 10 times in 9 eyes with a mean preinjection center field retinal thickness of 535 μm (range, 239-727 μm...... center field thickness and in 6 of 8 eyes by an increase in BCVA of 5 or more approxETDRS letters. A mild transient rise in intraocular pressure occurred in 3 out of 8 eyes. CONCLUSION: Diabetic macular edema involving the foveal center that presented during pregnancy responded promptly to intravitreal...

Neurokinin B and serum albumin limit copper binding to mammalian gonadotropin releasing hormone.

Science.gov (United States)

Gul, Ahmad Samir; Tran, Kevin K; Jones, Christopher E

2018-02-26

Gonadotropin releasing hormone (GnRH) triggers secretion of luteinizing hormone and follicle stimulating hormone from gonadotropic cells in the anterior pituitary gland. GnRH is able to bind copper, and both in vitro and in vivo studies have suggested that the copper-GnRH complex is more potent at triggering gonadotropin release than GnRH alone. However, it remains unclear whether copper-GnRH is the active species in vivo. To explore this we have estimated the GnRH-copper affinity and have examined whether GnRH remains copper-bound in the presence of serum albumin and the neuropeptide neurokinin B, both copper-binding proteins that GnRH will encounter in vivo. We show that GnRH has a copper dissociation constant of ∼0.9 × 10 -9  M, however serum albumin and neurokinin B can extract metal from the copper-GnRH complex. It is therefore unlikely that a copper-GnRH complex will survive transit through the pituitary portal circulation and that any effect of copper must occur outside the bloodstream in the absence of neurokinin B. Copyright © 2018 Elsevier Inc. All rights reserved.

Twice-weekly administration of kisspeptin-54 for 8 weeks stimulates release of reproductive hormones in women with hypothalamic amenorrhea.

Science.gov (United States)

Jayasena, C N; Nijher, G M K; Abbara, A; Murphy, K G; Lim, A; Patel, D; Mehta, A; Todd, C; Donaldson, M; Trew, G H; Ghatei, M A; Bloom, S R; Dhillo, W S

2010-12-01

Kisspeptin is a novel therapeutic target for infertility. A single kisspeptin-54 (KP-54) injection acutely stimulates the release of reproductive hormones in women with hypothalamic amenorrhea (HA), a commonly occurring condition characterized by absence of menstruation; however, twice-daily administration of KP-54 results in tachyphylaxis. We determined the time course of desensitization to twice-daily KP-54 injections, compared the effects of twice-daily and twice-weekly administration regimens of KP-54, and studied the effects of long-term twice-weekly administration of KP-54 on the release of reproductive hormones in women with HA. When KP-54 was administered twice daily, responsiveness to luteinizing hormone (LH) diminished gradually, whereas responsiveness to follicle-stimulating hormone (FSH) was nearly abolished by day 2. Twice-weekly KP-54 administration resulted in only partial desensitization, in contrast to the complete tolerance achieved with twice-daily administration. Women with HA who were treated with twice-weekly KP-54 injections had significantly elevated levels of reproductive hormones after 8 weeks as compared with treatment with saline. No adverse effects were observed. This study provides novel pharmacological data on the effects of KP-54 on the release of reproductive hormones in women with HA.

Effects of thyrotropin-releasing hormone on regional cerebral blood flow in man

DEFF Research Database (Denmark)

Oturai, P S; Friberg, L; Sam, I

1992-01-01

emission computerized tomograph and inhalation of 133Xe. Thyrotropin-releasing hormone caused a significant mean increase of 3.7% (range -8.8-22.7) in blood flow in a region consistent with the left thalamus compared to placebo (3.2% decrease). In 25 other regions no significant change was detected...

Association of plasma hormones, nutritional status, and stressful life events in anorexia nervosa patients

Directory of Open Access Journals (Sweden)

Małgorzata Śmiarowska

2014-02-01

Full Text Available Objective: The aim of the current study was to analyze the relationships between plasma hormones, body weight parameters and stressful life events in anorexia nervosa (AN. Material and Methods: 72 females in the active phase of AN were evaluated. 52 healthy women constituted the control group. RIA kits were used to measure plasma hormone levels. Results: The concentrations of leptin, insulin, IGF-1, triiodothyronine, LH, FSH, estradiol, and testosterone were significantly lower and those of cortisol and growth hormone significantly higher in the AN than the control group. No hormonal differences between restrictive and binge-purging AN subtypes were found. Leptin, IGF-1, gonadotropins, and sex steroids correlated significantly negatively and growth hormone positively with total reduction of body weight or the degree of undernutrition. Associations were also found between lower insulin concentration and family violence, lower cortisol and psychiatric diseases in the family, higher testosterone and patient’s alcohol or drug abuse. Discussion: The changed activity of the somatotropin-somatomedin, gonadal, and corticotrophin axes corresponds to the clinical stage of AN. Plasma IGF-1 seems to be the most sensitive and useful independent hormonal marker of cachexia.

The effect of short-term cortisol changes on growth hormone responses to the pyridostigmine-growth-hormone-releasing-hormone test in healthy adults and patients with suspected growth hormone deficiency

DEFF Research Database (Denmark)

Andersen, M; Støving, R K; Hangaard, J

1998-01-01

BACKGROUND AND AIMS: The interaction between cortisol and growth hormone (GH)-levels may significantly influence GH-responses to a stimulation test. In order to systematically analyse the interaction in a paired design, it is necessary to use a test, which has been proven safe and reliable...... such as the pyridostigmine-growth-hormone-releasing-hormone (PD-GHRH) test. Three groups of subjects with a different GH-secretory capacity were included. STUDY A: Eight healthy adults were tested seven times, once with placebo throughout the examination and six times with the PD-GHRH test following no glucocorticoid......-responses to a PD-GHRH test were reduced in all individuals during acute stress-appropriate cortisol levels and the percentage reduction in GH-levels was independent of the GH-secretory capacity. Clinically, we found that peak GH-responses were not significantly affected by a short break in conventional HC therapy...

Luteinizing hormone-releasing hormone analogue (Buserelin) treatment for central precocious puberty: a multi-centre trial.

Science.gov (United States)

Werther, G A; Warne, G L; Ennis, G; Gold, H; Silink, M; Cowell, C T; Quigley, C; Howard, N; Antony, G; Byrne, G C

1990-02-01

A multi-centre open trial of Buserelin, a luteinizing hormone-releasing hormone (LHRH) analogue, was conducted in 13 children with central precocious puberty. Eleven children (eight girls and three boys), aged 3.4-10.2 years at commencement, completed the required 12 month period of treatment. Initially all patients received the drug by intranasal spray in a dose of 1200 micrograms/day, but by the end of the 12 month period two were having daily subcutaneous injections and three were receiving an increased dose intranasally. The first month of treatment was associated in one boy with increased aggression and masturbation, and in the girls with an increase in the prevalence of vaginal bleeding. Thereafter, however, both behavioural abnormalities and menstruation were suppressed. Median bone age increased significantly during the study, but without any significant change in the ratio of height age to bone age. The median predicted adult height for the group therefore did not alter significantly over the twelve months of the study. Buserelin treatment caused a reduction in the peak luteinizing hormone and follicle-stimulating hormone (FSH) responses to LHRH, mostly to prepubertal levels, and also suppressed basal FSH. In the first weeks of treatment, the girls' serum oestradiol levels rose significantly and then fell to prepubertal or early pubertal levels. A similar pattern was seen for serum testosterone levels. Serum somatomedin-C levels, however, showed little fluctuation over the course of the study. Buserelin treatment was safe and well accepted, and offers the promise of improved linear growth potential in precocious puberty.

Highly potent analogues of luteinizing hormone-releasing hormone containing D-phenylalanine nitrogen mustard in position 6.

Science.gov (United States)

Bajusz, S; Janaky, T; Csernus, V J; Bokser, L; Fekete, M; Srkalovic, G; Redding, T W; Schally, A V

1989-08-01

The nitrogen mustard derivatives of 4-phenylbutyric acid and L-phenylalanine, called chlorambucil (Chl) and melphalan (Mel), respectively, have been incorporated into several peptide hormones, including luteinizing hormone-releasing hormone (LH-RH). The alkylating analogues of LH-RH were prepared by linking Chl, as an N-acyl moiety, to the complete amino acid sequence of agonistic and antagonistic analogues. These compounds, in particular the antagonistic analogues, showed much lower potency than their congeners carrying other acyl groups. To obtain highly potent alkylating analogues of LH-RH, the D enantiomer of Mel was incorporated into position 6 of the native hormone and some of its antagonistic analogues. Of the peptides prepared, [D-Mel6]LH-RH (SB-05) and [Ac-D-Nal(2)1,D-Phe(pCl)2,D-Pal(3)3,Arg5,D-Mel6,D-Ala10++ +]LH-RH [SB-86, where Nal(2) is 3-(2-naphthyl)alanine and Pal(3) is 3-(3-pyridyl)alanine] possessed the expected high agonistic and antagonistic activities, respectively, and also showed high affinities for the membrane receptors of rat pituitary cells, human breast cancer cells, human prostate cancer cells, and rat Dunning R-3327 prostate tumor cells. These two analogues exerted cytotoxic effects on human and rat mammary cancer cells in vitro. Thus these two D-Mel6 analogues seem to be particularly suitable for the study of how alkylating analogues of LH-RH could interfere with intracellular events in certain cancer cells.

Highly potent analogues of luteinizing hormone-releasing hormone containing D-phenylalanine nitrogen mustard in position 6

International Nuclear Information System (INIS)

Bajusz, S.; Janaky, T.; Csernus, V.J.; Bokser, L.; Fekete, M.; Srkalovic, G.; Redding, T.W.; Schally, A.V.

1989-01-01

The nitrogen mustard derivatives of 4-phenylbutyric acid and L-phenylalanine, called chlorambucil (Chl) and melphalan (Mel), respectively, have been incorporated into several peptide hormones, including luteinizing hormone-releasing hormone (LH-RH). The alkylating analogues of LH-RH were prepared by linking Chl, as an N-acyl moiety, to the complete amino acid sequence of agonistic and antagonistic analogues. These compounds, in particular the antagonistic analogues, showed much lower potency than their congeners carrying other acyl groups. To obtain highly potent alkylating analogues of LH-RH, the D enantiomer of Mel was incorporated into position 6 of the native hormone and some of its antagonistic analogues. Of the peptides prepared, [D-Mel 6 ]LH-RH (SB-05) and [Ac-D-Nal(2) 1 ,D-Phe(pCl) 2 ,D-Pal(3) 3 ,Arg 5 ,D-Mel 6 ,D-Ala 10 ]LH-RH [SB-86, where Nal(2) is 3-(2-naphthyl)alanine and Pal(3) is 3-(3-pyridyl)alanine] possessed the expected high agonistic and antagonistic activities, respectively, and also showed high affinities for the membrane receptors of rat pituitary cells, human breast cancer cells, human prostate cancer cells, and rat Dunning R-3327 prostate tumor cells. These two analogues exerted cytotoxic effects on human and rat mammary cancer cells in vitro. Thus these two D-Mel 6 analogues seem to be particularly suitable for the study of how alkylating analogues of LH-RH could interfere with intracellular events in certain cancer cells

Corticotropine-releasing hormone and/or corticosterone differentially affect behavior of rat

Czech Academy of Sciences Publication Activity Database

Valeš, Karel; Řezáčová, Lenka; Stuchlík, Aleš

2008-01-01

Roč. 11, Suppl.1 (2008), s. 118-118 ISSN 1461-1457. [CINP Congress /26./. 13.07.2008-17.07.2008, Munich] R&D Projects: GA MŠk(CZ) 1M0517; GA MZd NR9180; GA ČR(CZ) GA309/07/0341 Institutional research plan: CEZ:AV0Z50110509 Keywords : cpo1 * corticotropine-releasing hormone * corticosterone * behavior Subject RIV: FH - Neurology

Pranic meditation affects phagocyte functions and hormonal levels of recent practitioners.

Science.gov (United States)

Fernandes, César A; Nóbrega, Yanna K M; Tosta, C Eduardo

2012-08-01

Despite the recognized importance of phagocytes in the maintenance and recovery of health, the influence of meditation on their functions is not properly established. This investigation aimed at evaluating the influence of pranic meditation on the functions of phagocytes, and on the levels of hormones that influence them. A pre-post design was adopted. The investigation was carried out at a university research laboratory. Twenty-nine (29) healthy individuals of both sexes, 24-67 years old (median 45), with no previous experience in meditation, received 3-hour-duration weekly training on pranic meditation during 10 weeks and agreed to engage in daily home practice for 20 minutes. Pranic meditation is a novel method of meditation, based on the Vedic tradition, which uses techniques of breathing and visualization for quieting the mind, and for capturing and intentionally directing prana ("vital energy") wherever necessary. For assessing phagocytosis, the production of hydrogen peroxide and nitric oxide by monocytes, and the concentrations of corticotrophin and cortisol, blood was collected at the beginning (week 1), at the middle (week 5), and by the end (week 10) of the practice period. At the same intervals, melatonin concentrations were evaluated in the saliva. Those who meditated for more than 980 minutes showed increased phagocytosis, their monocytes produced higher concentrations of hydrogen peroxide, and their plasma levels of corticotrophin were reduced. The production of nitric oxide by monocytes, and the levels of cortisol and melatonin were not modified by meditation. This is the first study to show that a short program of pranic meditation practice was able to upregulate the function and metabolism of phagocytes, in parallel with the reduction of the plasma levels of corticotrophin. The results of this study point to a possible causal effect between these events, and indicate that pranic meditation could be useful for stimulating the function and

4-(2-Chloro-4-methoxy-5-methylphenyl)-N-[(1S)-2-cyclopropyl-1-(3-fluoro-4-methylphenyl)ethyl]5-methyl-N-(2-propynyl)-1,3-thiazol-2-amine hydrochloride (SSR125543A): a potent and selective corticotrophin-releasing factor(1) receptor antagonist. I. Biochemical and pharmacological characterization.

Science.gov (United States)

Gully, Danielle; Geslin, Michel; Serva, Laurence; Fontaine, Evelyne; Roger, Pierre; Lair, Christine; Darre, Valerie; Marcy, Claudine; Rouby, Pierre-Eric; Simiand, Jacques; Guitard, Josette; Gout, Georgette; Steinberg, Regis; Rodier, Daniel; Griebel, Guy; Soubrie, Philippe; Pascal, Marc; Pruss, Rebecca; Scatton, Bernard; Maffrand, Jean-Pierre; Le Fur, Gerard

2002-04-01

4-(2-Chloro-4-methoxy-5-methylphenyl)-N-[(1S)-2-cyclopropyl-1- (3-fluoro-4-methylphenyl)ethyl]5-methyl-N-(2-propynyl)-1,3-thiazol-2-amine hydrochloride (SSR125543A), a new 2-aminothiazole derivative, shows nanomolar affinity for human cloned or native corticotrophin-releasing factor (CRF)(1) receptors (pK(i) values of 8.73 and 9.08, respectively), and a 1000-fold selectivity for CRF(1) versus CRF(2 alpha) receptor and CRF binding protein. SSR125543A antagonizes CRF-induced stimulation of cAMP synthesis in human retinoblastoma Y 79 cells (IC(50) = 3.0 +/- 0.4 nM) and adrenocorticotropin hormone (ACTH) secretion in mouse pituitary tumor AtT-20 cells. SSR125543A is devoid of agonist activity in these models. Its brain penetration was demonstrated in rats by using an ex vivo [(125)I-Tyr(0)] ovine CRF binding assay. SSR125543A displaced radioligand binding to the CRF(1) receptor in the brain with an ID(50) of 6.5 mg/kg p.o. (duration of action >24 h). SSR125543A also inhibited the increase in plasma ACTH levels elicited in rats by i.v. CRF (4 microg/kg) injection (ID(50) = 1, 5, or 5 mg/kg i.v., i.p., and p.o., respectively); this effect lasted for more than 6 h when the drug was given orally at a dose of 30 mg/kg. SSR125543A (10 mg/kg p.o.) reduced by 73% the increase in plasma ACTH levels elicited by a 15-min restraint stress in rats. Moreover, SSR125543A (20 mg/kg i.p.) also antagonized the increase of hippocampal acetylcholine release induced by i.c.v. injection of 1 microg of CRF in rats. Finally, SSR125543A reduced forepaw treading induced by i.c.v. injection of 1 microg of CRF in gerbils (ID(50) = approximately 10 mg/kg p.o.). Altogether, these data indicate that SSR125543A is a potent, selective, and orally active CRF(1) receptor antagonist.

Positive environmental modification of depressive phenotype and abnormal hypothalamic-pituitary-adrenal axis activity in female C57BL/6J mice during abstinence from chronic ethanol consumption

Directory of Open Access Journals (Sweden)

Terence Y Pang

2013-07-01

Full Text Available Depression is a commonly reported co-morbidity during rehabilitation from alcohol use disorders and its presence is associated with an increased likelihood of relapse. Interventions which impede the development of depression could be of potential benefit if incorporated into treatment programs. We previously demonstrated an ameliorative effect of physical exercise on depressive behaviours in a mouse model of alcohol abstinence. Here, we show that environmental enrichment (cognitive and social stimulation has a similar beneficial effect. The hypothalamic-pituitary-adrenal (HPA axis is a key physiological system regulating stress responses and its dysregulation has been separably implicated in the pathophysiology of depression and addiction disorders. We performed a series of dexamethasone challenges and found that mice undergoing 2 weeks of alcohol abstinence had significantly greater corticosterone and ACTH levels following a DEX-CRH challenge compared to water controls. Environmental enrichment during alcohol abstinence corrected the abnormal DEX-CRH corticosterone response despite a further elevation of ACTH levels. Examination of gene expression revealed abstinence-associated alterations in glucocorticoid receptor (Gr, corticotrophin releasing hormone (Crh and pro-opiomelanocortin (Pomc1 mRNA levels which were differentially modulated by environmental enrichment. Overall, our study demonstrates a benefit of environmental enrichment on alcohol abstinence-associated depressive behaviours and HPA axis dysregulation.

Ontogenesis of neurons producing luteinizing hormone-releasing hormone (LHRH) in the nervus terminalis of the rat.

Science.gov (United States)

Schwanzel-Fukuda, M; Morrell, J I; Pfaff, D W

1985-08-15

Immunoreactive luteinizing hormone-releasing hormone (LHRH) was first detected at 15 days of gestation in ganglion cells associated with the peripheral, intracranial, and central parts of the nervus terminalis of the rat. LHRH was not detected in any other structure of the central nervous system at this age. In the 17-day-old fetal rat, 62% of the total LHRH-reactive neuronal population was found in ganglion cells of the nervus terminalis. At this same age, immunoreactive beta-luteinizing hormone (beta-LH) was first seen in gonadotropes of the anterior pituitary gland. At 19 days of gestation, 31% of the total number of LHRH-reactive neurons observed in the rat brain was found in the nervus terminalis, and immunoreactive processes were first seen in the organum vasculosum of the lamina terminalis and in the median eminence. Our data indicate that from 15 to 19 days of gestation the nervus terminalis is a principal source of LHRH in the fetal rat. Presence of the decapeptide in the nervus terminalis prior to appearance of beta-LH in the anterior pituitary suggests a possible role for LHRH in this system on maturation of the gonadotropes and differentiation of the brain-pituitary-gonadal axis.

Gonadotrophin-Releasing Hormone Agonists and Other Contraceptive Medications in Exotic Companion Animals.

Science.gov (United States)

Schoemaker, Nico J

2018-05-01

The use of a gonadotrophin-releasing hormone agonist slow-release implant (GnRH A-SRI) has become increasingly popular as an alternative for surgical contraception in many species. Although these implants have proven to be very effective in some species (eg, ferrets, rats, chicken, psittacines, and iguanas), they have been found less effective in other species (eg, male guinea pigs and rabbits, veiled chameleons, slider turtles, and leopard geckos). This review provides an overview of the available literature on the effects of GnRH A-SRIs in companion exotic animals. Copyright © 2018 Elsevier Inc. All rights reserved.

Colocalization of connexin 36 and corticotropin-releasing hormone in the mouse brain

Directory of Open Access Journals (Sweden)

Ribeiro Ana C

2009-04-01

Full Text Available Abstract Background Gap junction proteins, connexins, are expressed in most endocrine and exocrine glands in the body and are at least in some glands crucial for the hormonal secretion. To what extent connexins are expressed in neurons releasing hormones or neuropeptides from or within the central nervous system is, however, unknown. Previous studies provide indirect evidence for gap junction coupling between subsets of neuropeptide-containing neurons in the paraventricular nucleus (PVN of the hypothalamus. Here we employ double labeling and retrograde tracing methods to investigate to what extent neuroendocrine and neuropeptide-containing neurons of the hypothalamus and brainstem express the neuronal gap junction protein connexin 36. Results Western blot analysis showed that connexin 36 is expressed in the PVN. In bacterial artificial chromosome transgenic mice, which specifically express the reporter gene Enhanced Green Fluorescent Protein (EGFP under the control of the connexin 36 gene promoter, EGFP expression was detected in magnocellular (neuroendocrine and in parvocellular neurons of the PVN. Although no EGFP/connexin36 expression was seen in neurons containing oxytocin or vasopressin, EGFP/connexin36 was found in subsets of PVN neurons containing corticotropin-releasing hormone (CRH, and in somatostatin neurons located along the third ventricle. Moreover, CRH neurons in brainstem areas, including the lateral parabrachial nucleus, also expressed EGFP/connexin 36. Conclusion Our data indicate that connexin 36 is expressed in subsets of neuroendocrine and CRH neurons in specific nuclei of the hypothalamus and brainstem.

Gonadotropin-releasing hormone radioimmunoassay and its measurement in normal human plasma, secondary amenorrhea, and postmenopausal syndrome

International Nuclear Information System (INIS)

Rosenblum, N.G.; Schlaff, S.

1976-01-01

A sensitive and specific double antibody radioimmunoassay for gonadotropin-releasing hormone (GnRH) has been developed for measurement in ethanol extracts of human plasma. Iodinated hormone was prepared with the use of the chloramine-T method, and antibodies were developed in rabbits over a six-month period with a GnRH synthetic copolymer immunogen. A Scatchard plot revealed at least three species of antibody. The assay can measure conservatively at the 5 pg. per milliliter level and shows no cross-reactivity with other available hypothalamic and pituitary hormones. The releasing hormone was quantitatively recovered from human plasma with immunologic identity to native hormone. Unextracted plasma could not be used because of nonspecific displacement. The measurement of GnRH in individuals receiving 100 μg of intravenous bolus infusions of the synthetic decapeptide show extremely elevated values with two half-lives: one of two to four minutes and another of 35 to 40 minutes. In our experiments, we have found measurable GnRH in patients with secondary amenorrhea and at the midcycle in normal women. In the normal cycling woman during the follicular and luteal phases, GnRH was undetectable. In postmenopausal women with extreme hypoestrogenism and markedly elevated luteinizing hormone values, GnRH was also undetectable. No bursts of GnRH could be detected in normal men when sampled every ten minutes over a two-hour period and every two hours throughout the day

Ovulation induction with pulsatile gonadotropin-releasing hormone (GnRH) or gonadotropins in a case of hypothalamic amenorrhea and diabetes insipidus.

Science.gov (United States)

Georgopoulos, N A; Markou, K B; Pappas, A P; Protonatariou, A; Vagenakis, G A; Sykiotis, G P; Dimopoulos, P A; Tzingounis, V A

2001-12-01

Hypothalamic amenorrhea is a treatable cause of infertility. Our patient was presented with secondary amenorrhea and diabetes insipidus. Cortisol and prolactin responded normally to a combined insulin tolerance test (ITT) and thyrotropin-releasing hormone (TRH) challenge, while thyroid-stimulating hormone (TSH) response to TRH was diminished, and no response of growth hormone to ITT was detected. Both luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels increased following gonadotropin-releasing hormone (GnRH) challenge. No response of LH to clomiphene citrate challenge was detected. Magnetic resonance imaging findings demonstrated a midline mass occupying the inferior hypothalamus, with posterior lobe not visible and thickened pituitary stalk. Ovulation induction was carried out first with combined human menopausal gonadotropins (hMG/LH/FSH) (150 IU/day) and afterwards with pulsatile GnRH (150 ng/kg/pulse). Ovulation was achieved with both pulsatile GnRH and combine gonadotropin therapy. Slightly better results were achieved with the pulsatile GnRH treatment.

Preparation of slowly released male sex hormone drug by radiation polymerization technique and its evaluation in vivo

International Nuclear Information System (INIS)

Liu Rueizhi; Lei Shaoqiong; Li Ximing

1992-01-01

The radiation polymerization technique was used for immobilization testosterone propionate into crosslinked network of poly hydroxyethyl methacrylate to prepare slowly released male sex hormone drug which is used for testicular prosthesis. The testicular prosthesis was transplanted into the scrotum of male rabbit whose testes was excised 2 months before the transplantation. Then the level of male sex hormone in serum was measured by radioimmunoassay once a week after transplantation. The results of measurement in a period of 6 months were shown that the testicular prosthesis has a stable release of male sex hormone. The testosterone level in serum of the castrated male rabbits rises markedly and finally stabilizes at the level of 429 ± 36 ng/100 ml after transplantation. Macroscopic examination of biopsies taken from the tissues around the testicular prosthesis showed that tissue compatibility was revealed well

Leucine deprivation stimulates fat loss via increasing CRH expression in the hypothalamus and activating the sympathetic nervous system.

Science.gov (United States)

Cheng, Ying; Zhang, Qian; Meng, Qingshu; Xia, Tingting; Huang, Zhiying; Wang, Chunxia; Liu, Bin; Chen, Shanghai; Xiao, Fei; Du, Ying; Guo, Feifan

2011-09-01

We previously showed that leucine deprivation decreases abdominal fat mass largely by increasing energy expenditure, as demonstrated by increased lipolysis in white adipose tissue (WAT) and uncoupling protein 1 (UCP1) expression in brown adipose tissue (BAT). The goal of the present study was to investigate the possible involvement of central nervous system (CNS) in this regulation and elucidate underlying molecular mechanisms. For this purpose, levels of genes and proteins related to lipolysis in WAT and UCP1 expression in BAT were analyzed in wild-type mice after intracerebroventricular administration of leucine or corticotrophin-releasing hormone antibodies, or in mice deleted for three β-adrenergic receptors, after being maintained on a leucine-deficient diet for 7 d. Here, we show that intracerebroventricular administration of leucine significantly attenuates abdominal fat loss and blocks activation of hormone sensitive lipase in WAT and induction of UCP1 in BAT in leucine-deprived mice. Furthermore, we provide evidence that leucine deprivation stimulates fat loss by increasing expression of corticotrophin-releasing hormone in the hypothalamus via activation of stimulatory G protein/cAMP/protein kinase A/cAMP response element-binding protein pathway. Finally, we show that the effect of leucine deprivation on fat loss is mediated by activation of the sympathetic nervous system. These results suggest that CNS plays an important role in regulating fat loss under leucine deprivation and thereby provide novel and important insights concerning the importance of CNS leucine in the regulation of energy homeostasis.

Development of a radioimmunoassay for circulating levels of gonadotropin releasing hormone

International Nuclear Information System (INIS)

Moodbidri, S.B.; Joshi, L.R.; Sheth, A.R.; Rao, S.S.

1976-01-01

A specific and sensitive radioimmunoassay system has been developed for measuring gonadotropin releasing hormone (GnRH) in unextracted human serum. Circulating levels of GnRH, LH and FSH were determined in 37 serum samples obtained from twenty normal healthy women on different days of the menstrual cycle. GnRH and LH but not FSH exhibited similar patterns during the menstrual cycle. 125 I-labelled GnRH was used in the RIA system. (author)

Inhibition of rat pituitary growth hormone (GH) release by subclinical levels of lead

International Nuclear Information System (INIS)

Camoratto, A.M.; White, L.M.; Lau, Y.S.; Moriarty, C.M.

1990-01-01

Lead toxicity has been associated with short stature in children. Since growth hormone is a major regulator of growth, the effects of chronic exposure to subclinical lead levels on pituitary function were assessed. Timed pregnant rats were given 125 ppm lead (as lead nitrate) in their drinking water beginning on day 5 of gestation. After weaning, pups were continued on lead until sacrifice at 7 weeks of age. The average blood lead level at this time was 18.9 ug/dl (range 13.7-27.8). On the day of sacrifice the pituitary was removed, hemisected and incubated with vehicle or 40 nM hGRH (human growth hormone releasing hormone). Pituitaries from chronically lead-treated pups were 64% less responsive to GRH than controls. In contrast, no difference in responsiveness was observed in pituitaries from the dams. The specific binding of GRH was also examined. Control animals showed a dose-dependent displacement of 125I-GRH by unlabeled ligand (10-1000 nM). In the pituitaries of lead-treated pups binding of labeled ligand was markedly reduced by unlabeled GRH (less than 100 nM). Chronic exposure to lead had no effect on serum GH or prolactin levels or on pituitary content of GH. These data suggest that one mechanism by which lead can affect growth is by inhibition of GH release

Octopus gonadotrophin-releasing hormone: a multifunctional peptide in the endocrine and nervous systems of the cephalopod.

Science.gov (United States)

Minakata, H; Shigeno, S; Kano, N; Haraguchi, S; Osugi, T; Tsutsui, K

2009-03-01

The optic gland, which is analogous to the anterior pituitary in the context of gonadal maturation, is found on the upper posterior edge of the optic tract of the octopus Octopus vulgaris. In mature octopus, the optic glands enlarge and secrete a gonadotrophic hormone. A peptide with structural features similar to that of vertebrate gonadotrophin-releasing hormone (GnRH) was isolated from the brain of octopus and was named oct-GnRH. Oct-GnRH showed luteinising hormone-releasing activity in the anterior pituitary cells of the Japanese quail Coturnix coturnix. Oct-GnRH immunoreactive signals were observed in the glandular cells of the mature optic gland. Oct-GnRH stimulated the synthesis and release of sex steroids from the ovary and testis, and elicited contractions of the oviduct. Oct-GnRH receptor was expressed in the gonads and accessory organs, such as the oviduct and oviducal gland. These results suggest that oct-GnRH induces the gonadal maturation and oviposition by regulating sex steroidogenesis and a series of egg-laying behaviours via the oct-GnRH receptor. The distribution and expression of oct-GnRH in the central and peripheral nervous systems suggest that oct-GnRH acts as a multifunctional modulatory factor in feeding, memory processing, sensory, movement and autonomic functions.

Effects of maternal dexamethasone exposure on hematological ...

African Journals Online (AJOL)

Exposure to dexamethasone at LD 1-14 and 1-21 significantly (P<0.05) reduced RBC and platelet counts but it raised MCV and MCH relative to control. This study suggests that prenatal and lactational dexamethasone administration may affect the hematological indices in the male offspring. Keywords: Dexamethasone ...

Biodegradable polyurethane nanocomposites containing dexamethasone for ocular route

Energy Technology Data Exchange (ETDEWEB)

Rodrigues da Silva, Gisele [Federal University of Sao Joao Del Rei, School of Pharmacy, Divinopolis, Minas Gerais (Brazil); Silva-Cunha, Armando da [Federal University of Minas Gerais, School of Pharmacy, Belo Horizonte, Minas Gerais (Brazil); Behar-Cohen, Francine [INSERM, Physiopathology of ocular diseases: Therapeutic innovations, Institut des Cordeliers, Paris (France); Laboratoire d' Innovations Therapeutiques, Fondation Rothschild, Paris (France); Universite Rene Descartes, Hotel Dieu University Hospital, Paris (France); Ayres, Eliane [Federal University of Minas Gerais, Department of Metallurgical and Materials Engineering, Belo Horizonte, Minas Gerais (Brazil); Orefice, Rodrigo L., E-mail: rorefice@demet.ufmg.br [Federal University of Minas Gerais, Department of Metallurgical and Materials Engineering, Belo Horizonte, Minas Gerais (Brazil)

2011-03-12

The treatment of posterior segment ocular diseases, such as uveitis, by using eye drops and oral drugs is usually not effective due to the body's natural barriers to drug penetration. In this study, ocular implants to treat uveitis were synthesized by incorporating dexamethasone acetate, an important type of corticoid used in the treatment of some uveitis, into a biodegradable polyurethane containi clay nanoparticles. Biodegradable polyurethane nanocomposites having poly(caprolactone) oligomers as soft segments were obtained by delaminating clay particles within a polyurethane aqueous dispersion. The drug was incorporated into the polymer by dispersing it in the waterborne polyurethane followed by a drying step. Nanoparticles derived from clay were demonstrated to be able to tailor the mechanical properties of polyurethanes to achieve values that can match the properties of ocular soft tissues. Infrared spectra (FTIR) showed that the presence of clay particles was able to change the microphase separation process typical of polyurethanes. X-ray diffraction and small angle x-ray scattering (SAXS) results were explored to show that the incorporation of both dexamethasone acetate and nanocomponents derived from clay led to a less defined two-phase polyurethane. The presence of clay nanoparticles increased the rate of drug release measured in vitro. Human retinal pigment epithelial cells (ARPE-19) were cultured in contact with polyurethanes and polyurethane nanocomposites, and the viability of them (evaluated by using MTT assay after 7 days) showed that no toxic components were released from polyurethanes containing no drugs during the test.

Biodegradable polyurethane nanocomposites containing dexamethasone for ocular route

International Nuclear Information System (INIS)

Rodrigues da Silva, Gisele; Silva-Cunha, Armando da; Behar-Cohen, Francine; Ayres, Eliane; Orefice, Rodrigo L.

2011-01-01

The treatment of posterior segment ocular diseases, such as uveitis, by using eye drops and oral drugs is usually not effective due to the body's natural barriers to drug penetration. In this study, ocular implants to treat uveitis were synthesized by incorporating dexamethasone acetate, an important type of corticoid used in the treatment of some uveitis, into a biodegradable polyurethane containi clay nanoparticles. Biodegradable polyurethane nanocomposites having poly(caprolactone) oligomers as soft segments were obtained by delaminating clay particles within a polyurethane aqueous dispersion. The drug was incorporated into the polymer by dispersing it in the waterborne polyurethane followed by a drying step. Nanoparticles derived from clay were demonstrated to be able to tailor the mechanical properties of polyurethanes to achieve values that can match the properties of ocular soft tissues. Infrared spectra (FTIR) showed that the presence of clay particles was able to change the microphase separation process typical of polyurethanes. X-ray diffraction and small angle x-ray scattering (SAXS) results were explored to show that the incorporation of both dexamethasone acetate and nanocomponents derived from clay led to a less defined two-phase polyurethane. The presence of clay nanoparticles increased the rate of drug release measured in vitro. Human retinal pigment epithelial cells (ARPE-19) were cultured in contact with polyurethanes and polyurethane nanocomposites, and the viability of them (evaluated by using MTT assay after 7 days) showed that no toxic components were released from polyurethanes containing no drugs during the test.

Pulsatile gonadotrophin releasing hormone for ovulation induction in subfertility associated with polycystic ovary syndrome

NARCIS (Netherlands)

Bayram, N.; van Wely, M.; van der Veen, F.

2004-01-01

BACKGROUND: In normal menstrual cycles, gonadotrophin releasing hormone (GnRH) secretion is pulsatile, with intervals of 60-120 minutes in the follicular phase. Treatment with pulsatile GnRH infusion by the intravenous or subcutaneous route using a portable pump has been used successfully in

Role of the new growth hormone-releasing secretagogues in the diagnosis of some hypothalamopituitary pathologies.

Science.gov (United States)

Casanueva, F F; Micic, D; Pombo, M; Leal, A; Bokser, L; Zugaza, J L; Dieguez, C

1996-08-01

Growth hormone (GH)-releasing hormone (GHRH) and somatostatin have a dominant role in regulating GH secretion. However, results of studies using the new class of GH secretogogues, particularly GHRP-6, indicate that there may also be other, as yet undefined, hypothalamic mechanisms involved. Studies in adults with hypothalamopituitary disconnection (functional pituitary stalk transection), show GHRP-6-mediated GH release to be completely blocked, indicating a main action at the hypothalamic rather than the pituitary level. The synergistic effect of GHRH plus GHRP-6 administration on GH release seen in normal adults (and virtually unaffected by age, obesity, or sex) is also absent in these patients, providing further support for this conclusion. Studies of the effects of GHRP-6 in children with GH deficiency due to perinatal pituitary stalk transection have produced similar findings. It is suggested that the combined GHRH plus GHRH-6 test should be a promising tool for diagnosing GH deficiency states in both children and adults, and may identify a subgroup of patients with GH deficiency caused by interruption of the hypothalamopituitary connection.

Expression and role of gonadotropin-releasing hormone 2 and its receptor in mammals

Science.gov (United States)

Gonadotropin-releasing hormone (GnRH1) and its receptor (GnRHR1) drive mammalian reproduction via regulation of the gonadotropins. Yet, a second form of GnRH (GnRH2) and its receptor (GnRHR2) also exist in some mammals. GnRH2 has been completely conserved throughout 500 million years of evolution, s...

Radioimmunoassay for luteinizing hormone releasing hormone in plasma

International Nuclear Information System (INIS)

Saito, Shiro; Musa, Kimitaka; Oshima, Ichiyo; Yamamoto, Suzuyo; Funato, Toyohiko

1975-01-01

A sensitive and specific double antibody radioimmunoassay has been developed capable of measuring LH-RH in extracted human plasma. Thyrotropin releasing hormone, lysine vasopressin and most of LH-RH analogues did not appear to affect the assay. Hypothalamic extract and some of the LH-RH analogues produced displacement curves which were parallel to the curve obtained with the synthetic LH-RH. Sensitivity of the radioimmunoassay was about 3 pg per assay tube. The coefficient of variation of intraassays was 6.4%, while that of interassays was 9.6%. Exogenous LH-RH could be quantitatively extracted by acidic ethanol when varying amounts of synthetic LH-RH were added to the plasma. Immunoreactivity of LH-RH was preserved in plasma for 2 hrs in the cold but was gradually reduced thereafter. The plasma levels of LH-RH were 20 pg/ml or less in normal adults and not detectable in children. Aged males over 60 yr and postmenopausal women showed a tendency to have higher levels of plasma LH-RH. The plasma LH-RH level was significantly higher in midcycle than in the follicular or luteal stages. The disappearance rate of LH-RH from the circulation after intravenous injection could be represented as half-times of 4-6 min. Between 0.2-0.4% of the injected dose was excreted into urine within 1 hr. These results indicate that the determination of LH-RH might be a useful tool for elucidating hypothalamic-pituitary-gonad interactions. (auth.)

Calcium-independent phosphatidylinositol response in gonadotropin-releasing-hormone-stimulated pituitary cells.

OpenAIRE

Naor, Z; Molcho, J; Zakut, H; Yavin, E

1985-01-01

This paper describes the effect of gonadotropin-releasing hormone (GnRH, gonadoliberin) on phospholipid metabolism in cultured rat pituitary cells. The cells were incubated with [32P]Pi to label endogenous phospholipids (10-60 min) and then stimulated with GnRH for up to 60 min. Cellular phospholipids were separated by two-dimensional t.l.c. and the radioactivity was determined. Phosphatidylinositol (PI), a minor constituent of cellular phospholipids (7.7%), was the major labelled phospholipi...

Premenstrual Exacerbation of Life-Threatening Asthma: Effect of Gonadotrophin Releasing Hormone Analogue Therapy

Directory of Open Access Journals (Sweden)

Alun L Edwards

1996-01-01

Full Text Available Variability in the severity of asthma during various phases of the menstrual cycle has been frequently suspected. However, the hormonal changes that might affect mediators of bronchospasm have yet to be elucidated. The case of a 41-year-old woman suffering from longstanding asthma with life-threatening exacerbations is reported. The patient was treated with buserelin, a gonadotropin releasing hormone (GnRH analogue, which created a temporary chemical menopause and thus permitted diagnosis of a premenstrual exacerbation of asthma and offered insight into potential therapy. GnRH analogues may therefore be of value in assessing women with severe asthma suspected to vary with the menstrual cycle. The addition of estrogens and progestins at the same time as treatment with GnRH analogue may be of value in determining the role of these hormones in the pathogenesis of menstrually related exacerbations of asthma.

contribution of growth hormone-releasing hormone and

African Journals Online (AJOL)

The strategy used was to stimulate GH secretion in 8 young ... treatment with two oral doses of 50 mg atenolol (to inhibit .... had normal baseline thyroid-stimulating hormone (TSH) ..... production rate of 14% per decade has been documented.'".

Paraventricular nucleus of the human hypothalamus in primary hypertension: Activation of corticotropin-releasing hormone neurons

NARCIS (Netherlands)

Goncharuk, Valeri D.; van Heerikhuize, Joop; Swaab, Dick F.; Buijs, Ruud M.

2002-01-01

By using quantitative immunohistochemical and in situ hybridization techniques, we studied corticotropin-releasing hormone (CRH)-producing neurons of the hypothalamic paraventricular nucleus (PVN) in patients who suffered from primary hypertension and died due to acute cardiac failure. The control

Levels of human and rat hypothalamic growth hormone-releasing factor as determined by specific radioimmunoassay systems

International Nuclear Information System (INIS)

Audhya, T.; Manzione, M.M.; Nakane, T.; Kanie, N.; Passarelli, J.; Russo, M.; Hollander, C.S.

1985-01-01

Polyclonal antibodies to synthetic human pancreatic growth hormone-releasing factor [hpGRF(1-44)NH 2 ] and rat hypothalamic growth hormone-releasing factor [rhGRF(1-43)OH] were produced in rabbits. A subsequent booster injection by the conventional intramuscular route resulted in high-titer antibodies, which at a 1:20,000 dilution were used to develop highly sensitive and specific radioimmunoassays for these peptides. The antibody to hpGRF(1-44)NH 2 is directed against the COOH-terminal region of the molecule, as shown by its cross reactivity with various hpGRF analogues. Serial dilutions of human and rat hypothalamic extracts demonstrated parallelism with the corresponding species-specific standard and 125 I-labeled tracer. There was no cross reactivity with other neuropeptides, gastrointestinal peptides, or hypothalamic extracts of other species. Age-related changes in hypothalamic GRF content were present in rats, with a gradual increase from 2 to 16 weeks and a correlation between increasing body weight and GRF content. These radioimmunoassays will serve as important tools for understanding the regulation of growth hormone secretion in both human and rat

Biosynthesis and release of thyrotropin-releasing hormone immunoreactivity in rat pancreatic islets in organ culture. Effects of age, glucose, and streptozotocin

DEFF Research Database (Denmark)

Dolva, L O; Welinder, B S; Hanssen, K F

1983-01-01

Thyrotropin-releasing hormone immunoreactivity (TRH-IR) was measured in isolated islets and in medium from rat pancreatic islets maintained in organ culture. TRH-IR in methanol extracts of both islets and culture medium was eluted in the same position as synthetic TRH by ion-exchange and gel...... chromatography and exhibited dilution curves parallel with synthetic TRH in radioimmunoassay. [3H]Histidine was incorporated into a component that reacted with TRH antiserum and had the same retention time as synthetic TRH on reversed-phase high-performance liquid chromatography. A continuous release of TRH...

Growth hormone-releasing hormone as an agonist of the ghrelin receptor GHS-R1a.

Science.gov (United States)

Casanueva, Felipe F; Camiña, Jesus P; Carreira, Marcos C; Pazos, Yolanda; Varga, Jozsef L; Schally, Andrew V

2008-12-23

Ghrelin synergizes with growth hormone-releasing hormone (GHRH) to potentiate growth hormone (GH) response through a mechanism not yet fully characterized. This study was conducted to analyze the role of GHRH as a potential ligand of the ghrelin receptor, GHS-R1a. The results show that hGHRH(1-29)NH(2) (GHRH) induces a dose-dependent calcium mobilization in HEK 293 cells stably transfected with GHS-R1a an effect not observed in wild-type HEK 293 cells. This calcium rise is also observed using the GHRH receptor agonists JI-34 and JI-36. Radioligand binding and cross-linking studies revealed that calcium response to GHRH is mediated by the ghrelin receptor GHS-R1a. GHRH activates the signaling route of inositol phosphate and potentiates the maximal response to ghrelin measured in inositol phosphate turnover. The presence of GHRH increases the binding capacity of (125)I-ghrelin in a dose dependent-fashion showing a positive binding cooperativity. In addition, confocal microscopy in CHO cells transfected with GHS-R1a tagged with enhanced green fluorescent protein shows that GHRH activates the GHS-R1a endocytosis. Furthermore, the selective GHRH-R antagonists, JV-1-42 and JMR-132, act also as antagonists of the ghrelin receptor GHS-R1a. Our findings suggest that GHRH interacts with ghrelin receptor GHS-R1a, and, in consequence, modifies the ghrelin-associated intracellular signaling pathway. This interaction may represent a form of regulation, which could play a putative role in the physiology of GH regulation and appetite control.

Protective effects of D-Trp6-luteinising hormone-releasing hormone microcapsules against cyclophosphamide-induced gonadotoxicity in female rats.

Science.gov (United States)

Bokser, L; Szende, B; Schally, A V

1990-06-01

The possible protective effect of an agonist of luteinising hormone-releasing hormone (LH-RH) against the ovarian damage caused by cyclophosphamide was investigated in rats. D-Trp6-LH-RH microcapsules were injected once a month for 3 months, in a dose calculated to release 25 micrograms day-1. Control animals received the injection vehicle. Sixty days after the first injection of microcapsules, cyclophosphamide was given at a loading dose of 50 mg kg-1 followed by 5 mg kg-1 day-1 for 30 days, while the treatment with D-Trp6-LH-RH was continued. When the ovaries were examined 3 months and 5 months after discontinuation of treatment, a significant reduction in the total number of follicles (P less than 0.01) was found in non-pretreated animals given cyclophosphamide. This reduction affected mainly follicles larger than 100 microns. An irreversible disintegration and destruction of granulosa cells was also observed in this group. In animals pretreated with D-Trp6-LH-RH, administration of cyclophosphamide caused no reduction in the number and diameter of follicles. Thus, the treatment with D-Trp6-LH-RH microcapsules before and during chemotherapy prevented the ovarian injury inflicted by cyclophosphamide. The suppression of gonadal function by LH-RH analogues could be possibly utilised for the protection of the ovaries against damage caused by cytotoxic drugs.

Evaluation of growth hormone release and human growth hormone treatment in children with cranial irradiation-associated short stature

International Nuclear Information System (INIS)

Romshe, C.A.; Zipf, W.B.; Miser, A.; Miser, J.; Sotos, J.F.; Newton, W.A.

1984-01-01

We studied nine children who had received cranial irradiation for various malignancies and subsequently experienced decreased growth velocity. Their response to standard growth hormone stimulation and release tests were compared with that in seven children with classic GH deficiency and in 24 short normal control subjects. With arginine and L-dopa stimulation, six of nine patients who received radiation had a normal GH response (greater than 7 ng/ml), whereas by design none of the GH deficient and all of the normal children had a positive response. Only two of nine patients had a normal response to insulin hypoglycemia, with no significant differences in the mean maximal response of the radiation and the GH-deficient groups. Pulsatile secretion was not significantly different in the radiation and GH-deficient groups, but was different in the radiation and normal groups. All subjects in the GH-deficient and radiation groups were given human growth hormone for 1 year. Growth velocity increased in all, with no significant difference in the response of the two groups when comparing the z scores for growth velocity of each subject's bone age. We recommend a 6-month trial of hGH in children who have had cranial radiation and are in prolonged remission with a decreased growth velocity, as there is no completely reliable combination of GH stimulation or release tests to determine their response

Gonadotropin-releasing hormone agonist versus HCG for oocyte triggering in antagonist assisted reproductive technology cycles

NARCIS (Netherlands)

Youssef, Mohamed A. F. M.; van der Veen, Fulco; Al-Inany, Hesham G.; Griesinger, Georg; Mochtar, Monique H.; Aboulfoutouh, Ismail; Khattab, Sherif M.; van Wely, Madelon

2011-01-01

Background Gonadotropin-releasing hormone (GnRH) antagonist protocols for pituitary down regulation in in vitro fertilisation (IVF) and intracytoplasmic sperm injection (ICSI) allow the use of GnRH agonists for triggering final oocyte maturation. Currently, human chorionic gonadotropin (HCG) is

Ectopic corticotropin-releasing hormone (CRH syndrome from metastatic small cell carcinoma: a case report and review of the literature

Directory of Open Access Journals (Sweden)

Shahani Sadeka

2010-08-01

Full Text Available Abstract Background Cushing's Syndrome (CS which is caused by isolated Corticotropin-releasing hormone (CRH production, rather than adrenocorticotropin (ACTH production, is extremely rare. Methods We describe the clinical presentation, course, laboratory values and pathologic findings of a patient with isolated ectopic CRH causing CS. We review the literature of the types of tumors associated with this unusual syndrome and the behavior of these tumors by endocrine testing. Results A 56 year old woman presented with clinical and laboratory features consistent with ACTH-dependent CS. Pituitary imaging was normal and cortisol did not suppress with a high dose dexamethasone test, consistent with a diagnosis of ectopic ACTH. CT imaging did not reveal any discrete lung lesions but there were mediastinal and abdominal lymphadenopathy and multiple liver lesions suspicious for metastatic disease. Laboratory testing was positive for elevated serum carcinoembryonic antigen and the neuroendocrine marker chromogranin A. Serum markers of carcinoid, medullary thyroid carcinoma, and pheochromocytoma were in the normal range. Because the primary tumor could not be identified by imaging, biopsy of the presumed metastatic liver lesions was performed. Immunohistochemistry was consistent with a neuroendocrine tumor, specifically small cell carcinoma. Immunostaining for ACTH was negative but was strongly positive for CRH and laboratory testing revealed a plasma CRH of 10 pg/ml (normal 0 to 10 pg/ml which should have been suppressed in the presence of high cortisol. Conclusions This case illustrates the importance of considering the ectopic production of CRH in the differential diagnosis for presentations of ACTH-dependent Cushing's Syndrome.

Dexamethasone Therapy for Bacterial Meningitis: Better Never Than Late?

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Susan M King

1994-01-01

Full Text Available A multicentre randomized controlled trial was conducted in children with bacterial meningitis using dexamethasone or placebo for four days within 24 h of starting antibiotics. Primary outcomes were hearing loss and neurological abnormalities at 12 months after meningitis. The dexamethasone (n=50 and placebo (n=51 groups were similar in age, severity of illness and etiological agent. Hearing loss occurred in 10% and 11% of the dexamethasone and placebo groups and neurological deficits occurred in 20% and 18% of patients, respectively. Duodenal perforation occurred in one dexamethasone-treated child. In conclusion, there was no significant benefit in those receiving dexamethasone. The lack of benefit may have been due to the delay in administration of dexamethasone (median delay of 11 h after antibiotics. Therefore, if dexamethasone is used for meningitis it should be given immediately with the antibiotic.

The effects of dexamethasone on the Na,K-ATPase activity and pump function of corneal endothelial cells.

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Hatou, Shin; Yamada, Masakazu; Mochizuki, Hiroshi; Shiraishi, Atsushi; Joko, Takeshi; Nishida, Teruo

2009-05-01

The Na(+)- and K(+)-dependent ATPase (Na,K-ATPase) expressed in the basolateral membrane of corneal endothelial cells plays an important role in the pump function of the corneal endothelium. We investigated the possible role of dexamethasone in the regulation of Na,K-ATPase activity and pump function in corneal endothelial cells. Confluent monolayers of mouse corneal endothelial cells were exposed to dexamethasone. ATPase activity of the cells was evaluated by spectrophotometric measurement of phosphate released from ATP with the use of ammonium molybdate, with Na,K-ATPase activity being defined as the portion of total ATPase activity sensitive to ouabain. Pump function of the cells was measured with the use of an Ussing chamber, with the pump function attributable to Na,K-ATPase activity being defined as the portion of the total short-circuit current sensitive to ouabain. Western blot analysis was examined to measure the expression of the Na,K-ATPase alpha(1)-subunit. Dexamethasone (1 or 10 microM) increased the Na,K-ATPase activity and pump function of the cultured cells. These effects of dexamethasone were blocked by cycloheximide, a protein synthesis inhibitor. Western blot analysis also indicated that dexamethasone increased the expression of the Na,K-ATPase alpha(1)-subunit, whereas it decreased the expression of the phospho-Na,K-ATPase alpha(1)-subunit. Our results suggest that dexamethasone stimulates Na,K-ATPase activity in mouse corneal endothelial cells. The effect of dexamethasone activation in these cells is mediated by Na,K-ATPase synthesis and increase in an enzymatic activity by dephosphorylation of Na,K-ATPase alpha(1)-subunits.

Treatment of idiopathic hypogonadotropic hypogonadism in men with luteinizing hormone-releasing hormone: a comparison of treatment with daily injections and with the pulsatile infusion pump.

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Shargil, A A

1987-03-01

Thirty husbands in childless couples, aged 24 to 35 years, were treated with luteinizing hormone-releasing hormone (LH-RH) for idiopathic hypogonadotropic hypogonadism (IHH) of peripubertal (incomplete) type. They were azoospermic or oligospermic, with less than 1.5 X 10(6)/ml nonmotile spermatozoa. The diagnosis of IHH was based on clinical and laboratory features and testicular biopsy specimen study and was further supported by results of stimulation tests and gonadotropin-releasing hormone (GnRH) test. Two treatment modalities were used: subcutaneous injections of 500 micrograms LH-RH twice daily; and perpetual subcutaneous injection, via portable infusion pump, of 25 ng/kg LH-RH, at 90-minute intervals. Two patients required a short second period of pulsatile treatment to cause a second pregnancy of their spouses. The pump proved to yield better results, compared with intermittent injections, in respect to endocrine responses, spermatogenesis, and fertility capacity. Normal levels of luteinizing hormone and follicle-stimulating hormone were reached in 2 to 3 weeks and normal testosterone levels in 8 to 10 weeks from the start of treatment. Sperm counts rose to greater than 60 X 10(6)/ml viable spermatozoa with less than 15% of abnormal forms in 3 to 5 months, and the wives conceived. Of a total of 18 deliveries of healthy infants, 12 offspring were identified genetically with their fathers. Four women were still pregnant at the conclusion of the study. The pump was well tolerated, without special operational problems to the patients. Pulsatile treatment is therefore recommended in the treatment of well-diagnosed and carefully selected cases of incomplete IHH.

Dexamethasone Protects Against Tourniquet-Induced Acute Ischemia-Reperfusion Injury in Mouse Hindlimb

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Ryan M. Corrick

2018-03-01

Full Text Available Extremity injuries with hemorrhage have been a significant cause of death in civilian medicine and on the battlefield. The use of a tourniquet as an intervention is necessary for treatment to an injured limb; however, the tourniquet and subsequent release results in serious acute ischemia-reperfusion (IR injury in the skeletal muscle and neuromuscular junction (NMJ. Much evidence demonstrates that inflammation is an important factor to cause acute IR injury. To find effective therapeutic interventions for tourniquet-induced acute IR injuries, our current study investigated effect of dexamethasone, an anti-inflammatory drug, on tourniquet-induced acute IR injury in mouse hindlimb. In C57/BL6 mice, a tourniquet was placed on unilateral hindlimb (left hindlimb at the hip joint for 3 h, and then released for 24 h to induce IR. Three hours of tourniquet and 24 h of release (24-h IR caused gastrocnemius muscle injuries including rupture of the muscle sarcolemma and necrosis (42.8 ± 2.3% for infarct size of the gastrocnemius muscle. In the NMJ, motor nerve terminals disappeared, and endplate potentials were undetectable in 24-h IR mice. There was no gastrocnemius muscle contraction in 24-h IR mice. Western blot data showed that inflammatory cytokines (TNFα and IL-1β were increased in the gastrocnemius muscle after 24-h IR. Treatment with dexamethasone at the beginning of reperfusion (1 mg/kg, i.p. significantly inhibited expression of TNFα and IL-1β, reduced rupture of the muscle sarcolemma and infarct size (24.8 ± 2.0%, and improved direct muscle stimulation-induced gastrocnemius muscle contraction in 24-h IR mice. However, this anti-inflammatory drug did not improve NMJ morphology and function, and sciatic nerve-stimulated skeletal muscle contraction in 24-h IR mice. The data suggest that one-time treatment with dexamethasone at the beginning of reperfusion only reduced structural and functional impairments of the skeletal muscle but not the

Semi-quantitative ultrastructural analysis of the localization and neuropeptide content of gonadotropin releasing hormone nerve terminals in the median eminence throughout the estrous cycle of the rat.

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Prevot, V; Dutoit, S; Croix, D; Tramu, G; Beauvillain, J C

1998-05-01

The ultrastructural appearance of gonadotropin releasing hormone-immunoreactive elements was studied in the external zone of the median eminence of adult female Wistar rats. On the one hand, the purpose of the study was to determine the distribution of gonadotropin releasing hormone terminals towards the parenchymatous basal lamina at the level of hypothalamo-hypophyseal portal vessels, throughout the estrous cycle. On the other hand, we have semi-quantified the gonadotropin releasing hormone content in nerve terminals or preterminals during this physiological condition. A morphometric study was coupled to a colloidal 15 mn gold postembedding immunocytochemistry procedure. Animals were killed at 09.00 on diestrus II, 0.900, 10.00, 13.00, 17.00 and 18.00 on proestrus and 09.00 on estrus (n = 4-8 rats/group). A preliminary light microscopic study was carried out to identify an antero-posterior part of median eminence strongly immunostained by anti-gonadotropin releasing hormone antibodies but which was, in addition, easily spotted. This last condition was necessary to make a good comparison between each animal. Contacts between gonadotropin releasing hormone nerve terminals and the basal lamina were observed only the day of proestrus. Such contacts, however, were rare and in the great majority of cases, gonadotropin releasing hormone terminals are separated from basal lamina by tanycytic end feet. The morphometric analysis showed no significant variation in average distance between gonadotropin releasing hormone terminals and capillaries throughout the estrous cycle. Consequently, it did not appear that a large neuroglial plasticity exists during the estrous cycle. However, the observation of contacts only on proestrus together with some ultrastructural images evoke the possibility of a slight plasticity. The semi-quantitative results show that the content of gonadotropin releasing hormone in the nerve endings presented two peaks on proestrus: one at 09.00 (23 +/- 5

Characterization of brn1.2 and corticotropin-releasing hormone genes in zebrafish

OpenAIRE

Chandrasekar, Gayathri

2007-01-01

The zebrafish (Danio rerio), a tropical fresh water fish originally found in the rivers of India and Bangladesh has become a popular vertebrate model system over the last decade. The rapid sequencing of the zebrafish genome together with the latest advances in forward and reverse genetics has made this model organism more fascinating as it can be used to decipher the genetic mechanisms involved in the vertebrate development. Corticotropin-releasing hormone (CRH) regulates t...

Evaluation of in vivo [corrected] biological activity of new agmatine analogs of growth hormone-releasing hormone (GH-RH)

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Bokser, L; Zarandi, M; Schally, A V

1990-01-01

The effects of agmatine analogs of growth hormone releasing hormone (GH-RH) were compared to GH-RH(1-29)-NH2 after intravenous (iv) and subcutaneous (sc) administration to pentobarbital-anesthetized male rats. After the iv injection, the analogs [desNH2-Tyr1,Ala15,Nle27] GH-RH(1-28)Agm (MZ-2-51); [desNH2-Tyr1,D-Lys12,Ala15,Nle27] GH-RH(1-28)Agm (MZ-2-57); [desNH2-Tyr1,Ala15,D-Lys21,Nle27] GH-RH(1-28)Agm (MZ-2-75) and [desNH2-Tyr1, D-Lys12,21, Ala15, Nle27] GH-RH(1-28)Agm (MZ-2-87) showed a potency equivalent to 4.4, 1.9, 1.07 and 1.03 times that of GH-RH (1-29)-NH2, respectively, at 5 min and 5.6, 1.8, 1.9 and 1.8 times higher, respectively, at 15 min. After sc administration, analogs MZ-2-51, MZ-2-57 and MZ-2-75 showed to be 34.3, 14.3 and 10.5 times more potent than the parent hormone at 15 min and 179.1, 88.9 and 45.0 times more active, respectively, at 30 min. In addition, MZ-2-51 had prolonged GH-releasing activity as compared to the standard. We also compared the activity of MZ-2-51 and MZ-2-57 with their homologous L-Arg and D-Arg analogs [desNH2-Tyr1,Ala15,Nle27] GH-RH(1-29)-NH2 (MZ-2-117), [des-NH2Tyr1,D-Lys12, Ala15, Nle27] GH-RH(1-29)NH2 (MZ-2-123) and [desNH2-Tyr1,D-Lys12,Ala15, Nle27,D-Arg29] GH-RH(1-29)NH2 (MZ-2-135) after intramuscular (im) injection. MZ-2-51 induced a somewhat greater GH release than MZ-2-117 at 15 min, both responses being larger than the controls (p less than 0.01) at 15 and 30 min. MZ-2-57, MZ-2-123 and MZ-2-135 given i.m. were able to stimulate GH release only at 15 minutes (p less than 0.05). Animals injected i.m. with MZ-2-51, but not with MZ-2-117, showed GH levels significantly higher than the control group (p less than 0.05) at 60 min. GH-RH(1-29)NH2 had low activity intramuscularly when tested at a dose of 2.5 micrograms. No toxic effects were observed after the iv administration of 1 mg/kg of Agm GH-RH analogs. These results indicate that our Agm analogs are active iv, sc and im and that the substitutions made in these

Unraveling vasotocinergic, isotocinergic and stress pathways after food deprivation and high stocking density in the gilthead sea bream.

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Skrzynska, Arleta Krystyna; Martos-Sitcha, Juan Antonio; Martínez-Rodríguez, Gonzalo; Mancera, Juan Miguel

2018-01-01

The influence of chronic stress, induced by food deprivation (FD) and/or high stocking density (HSD), was assessed on stress, vasotocinergic and isotocinergic pathways of the gilthead sea bream (Sparus aurata). Fish were randomly assigned to one of the following treatments: (1) fed at low stocking density (LSD-F; 5kg·m -3 ); (2) fed at high stocking density (HSD-F, 40kg·m -3 ); (3) food-deprived at LSD (LSD-FD); and (4) food-deprived at HSD (HSD-FD). After 21days, samples from plasma, liver, hypothalamus, pituitary and head-kidney were collected. Both stressors (FD and HSD) induced a chronic stress situation, as indicated by the elevated cortisol levels, the enhancement in corticotrophin releasing hormone (crh) expression and the down-regulation in corticotrophin releasing hormone binding protein (crhbp) expression. Changes in plasma and liver metabolites confirmed a metabolic adjustment to cope with energy demand imposed by stressors. Changes in avt and it gene expression, as well as in their specific receptors (avtrv1a, avtrv2 and itr) at central (hypothalamus and pituitary) and peripheral (liver and head-kidney) levels, showed that vasotocinergic and isotocinergic pathways are involved in physiological changes induced by FD or HSD, suggesting that different stressors are handled through different stress pathways in S. aurata. Copyright © 2017 Elsevier Inc. All rights reserved.

Gonadotropin-Releasing Hormone Stimulate Aldosterone Production in a Subset of Aldosterone-Producing Adenoma

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Kishimoto, Rui; Oki, Kenji; Yoneda, Masayasu; Gomez-Sanchez, Celso E.; Ohno, Haruya; Kobuke, Kazuhiro; Itcho, Kiyotaka; Kohno, Nobuoki

2016-01-01

Abstract We aimed to detect novel genes associated with G protein-coupled receptors (GPCRs) in aldosterone-producing adenoma (APA) and elucidate the mechanisms underlying aldosterone production. Microarray analysis targeting GPCR-associated genes was conducted using APA without known mutations (APA-WT) samples (n = 3) and APA with the KCNJ5 mutation (APA-KCNJ5; n = 3). Since gonadotropin-releasing hormone receptor (GNRHR) was the highest expression in APA-WT by microarray analysis, we investigated the effect of gonadotropin-releasing hormone (GnRH) stimulation on aldosterone production. The quantitative polymerase chain reaction assay results revealed higher GNRHR expression levels in APA-WT samples those in APA-KCNJ5 samples (P APA-WT samples, and there was a significant and positive correlation between GNRHR and LHCGR expression in all APA samples (r = 0.476, P APA-WT (n = 9), which showed higher GNRHR and LHCGR levels, had significantly higher GnRH-stimulated aldosterone response than those with APA-KCNJ5 (n = 13) (P APA-WT, and the molecular analysis including the receptor expression associated with clinical findings of GnRH stimulation. PMID:27196470

Sexual dimorphism of stress response and immune/ inflammatory reaction: the corticotropin releasing hormone perspective

Directory of Open Access Journals (Sweden)

Nicholas V. Vamvakopoulos

1995-01-01

Full Text Available This review higlghts key aspects of corticotropin releasing hormone (CRH biology of potential relevance to the sexual dimorphism of the stress response and immune/inflammatory reaction, and introduces two important new concepts based on the regulatory potential of the human (h CRH gene: (1 a proposed mechanism to account for the tissue-specific antithetical responses of hCRH gene expression to glucocorticolds, that may also explain the frequently observed antithetical effects of chronic glucocorticoid administration in clinical practice and (2 a heuristic diagram to illustrate the proposed modulation of the stress response and immune/ inflammatory reaction by steroid hormones, from the perspective of the CRH system.

Macrophage migration inhibitory factor counter-regulates dexamethasone-induced annexin 1 expression and influences the release of eicosanoids in murine macrophages.

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Sun, Yu; Wang, Yu; Li, Jia-Hui; Zhu, Shi-Hui; Tang, Hong-Tai; Xia, Zhao-Fan

2013-10-01

Macrophage migration inhibitory factor (MIF), a pro-inflammatory cytokine and glucocorticoid (GC) counter-regulator, has emerged as an important modulator of inflammatory responses. However, the molecular mechanisms of MIF counter-regulation of GC still remain incomplete. In the present study, we investigated whether MIF mediated the counter-regulation of the anti-inflammatory effect of GC by affecting annexin 1 in RAW 264.7 macrophages. We found that stimulation of RAW 264.7 macrophages with lipopolysaccharide (LPS) resulted in down-regulation of annexin 1, while GC dexamethasone (Dex) or Dex plus LPS led to significant up-regulation of annexin 1 expression. RNA interference-mediated knockdown of intracellular MIF increased annexin 1 expression with or without incubation of Dex, whereas Dex-induced annexin 1 expression was counter-regulated by the exogenous application of recombinant MIF. Moreover, recombinant MIF counter-regulated, in a dose-dependent manner, inhibition of cytosolic phospholipase A2α (cPLA2α) activation and prostaglandin E2 (PGE2 ) and leukotriene B4 (LTB4 ) release by Dex in RAW 264.7 macrophages stimulated with LPS. Endogenous depletion of MIF enhanced the effects of Dex, reflected by further decease of cPLA2α expression and lower PGE2 and LTB4 release in RAW 264.7 macrophages. Based on these data, we suggest that MIF counter-regulates Dex-induced annexin 1 expression, further influencing the activation of cPLA2α and the release of eicosanoids. These findings will add new insights into the mechanisms of MIF counter-regulation of GC. © 2013 John Wiley & Sons Ltd.

Permissive effect of dexamethasone on the increase of proenkephalin mRNA induced by depolarization of chromaffin cells

International Nuclear Information System (INIS)

Naranjo, J.R.; Mocchetti, I.; Schwartz, J.P.; Costa, E.

1986-01-01

In cultured bovine chromaffin cells, changes in the dynamic state of enkephalin stores elicited experimentally were studied by measuring cellular proenkephalin mRNA, as well as enkephalin precursors and authentic enkephalin content of cells and culture media. In parallel, tyrosine hydroxylase mRNA and catecholamine cell content were also determined. Low concentrations (0.5-100 pM) of dexamethasone increased the cell contents of proenkephalin mRNA and enkephalin-containing peptides. High concentrations of the hormone(1 μM) were required to increase the cell contents of tyrosine hydroxylase mRNA and catecholamines. Depolarization of the cells with 10 μM veratridine resulted in a depletion of enkephalin and catecholamine stores after 24 hr. The enkephalin, but not the catecholamine, content was restored by 48 hr. An increase in proenkephalin mRNA content might account for the recovery; this increase was curtailed by tetrodotoxin and enhanced by 10 pM dexamethasone. Tyrosine hydroxylase mRNA content was not significantly modified by depolarization, even in the presence of 1 μM dexamethasone. Aldosterone, progesterone, testosterone, or estradiol (1 μM) failed to change proenkephalin mRNA. Hence, dexamethasone appears to exert a specific permissive action on the stimulation of the proenkephalin gene elicited by depolarization. Though the catecholamines and enkephalins are localized in the same chromaffin granules and are coreleased by depolarization, the genes coding for the processes that are rate limiting in the production of these neuromodulators can be differentially regulated

Growth hormone-releasing hormone promotes survival of cardiac myocytes in vitro and protects against ischaemia-reperfusion injury in rat heart.

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Granata, Riccarda; Trovato, Letizia; Gallo, Maria Pia; Destefanis, Silvia; Settanni, Fabio; Scarlatti, Francesca; Brero, Alessia; Ramella, Roberta; Volante, Marco; Isgaard, Jorgen; Levi, Renzo; Papotti, Mauro; Alloatti, Giuseppe; Ghigo, Ezio

2009-07-15

The hypothalamic neuropeptide growth hormone-releasing hormone (GHRH) stimulates GH synthesis and release in the pituitary. GHRH also exerts proliferative effects in extrapituitary cells, whereas GHRH antagonists have been shown to suppress cancer cell proliferation. We investigated GHRH effects on cardiac myocyte cell survival and the underlying signalling mechanisms. Reverse transcriptase-polymerase chain reaction analysis showed GHRH receptor (GHRH-R) mRNA in adult rat ventricular myocytes (ARVMs) and in rat heart H9c2 cells. In ARVMs, GHRH prevented cell death and caspase-3 activation induced by serum starvation and by the beta-adrenergic receptor agonist isoproterenol. The GHRH-R antagonist JV-1-36 abolished GHRH survival action under both experimental conditions. GHRH-induced cardiac cell protection required extracellular signal-regulated kinase (ERK)1/2 and phosphoinositide-3 kinase (PI3K)/Akt activation and adenylyl cyclase/cAMP/protein kinase A signalling. Isoproterenol strongly upregulated the mRNA and protein of the pro-apoptotic inducible cAMP early repressor, whereas GHRH completely blocked this effect. Similar to ARVMs, in H9c2 cardiac cells, GHRH inhibited serum starvation- and isoproterenol-induced cell death and apoptosis through the same signalling pathways. Finally, GHRH improved left ventricular recovery during reperfusion and reduced infarct size in Langendorff-perfused rat hearts, subjected to ischaemia-reperfusion (I/R) injury. These effects involved PI3K/Akt signalling and were inhibited by JV-1-36. Our findings suggest that GHRH promotes cardiac myocyte survival through multiple signalling mechanisms and protects against I/R injury in isolated rat heart, indicating a novel cardioprotective role of this hormone.

Non-invasive treatments of luteinizing hormone-releasing hormone for inducing spermiation in American (Bufo americanus) and Gulf Coast (Bufo valliceps) toads.

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Rowson, Angela D.; Obringer, Amy R.; Roth, Terri L.

2001-01-01

As many as 20% of all assessed amphibian species are threatened with extinction, and captive breeding programs are becoming important components of conservation strategies for this taxon. For some species, exogenous hormone administration has been integrated into breeding protocols to improve propagation. However, most treatments are administered by an intraperitoneal injection that can be associated with some risks. The general goal of this study was to identify a non-invasive method of applying luteinizing hormone-releasing hormone (LHRH), which reliably induces sperm release in toads. Specific objectives were to 1) test the spermiation response after topical application of different LHRH doses to the abdominal seat region, 2) evaluate the effects of adding the absorption enhancers dimethyl sulfoxide (DMSO), acetone, and glyceryl monocaprylate (GMC) to the LHRH, 3) assess the spermiation response after oral delivery of LHRH in a mealworm vehicle, and 4) compare sperm characteristics and spermiation responses to treatments in two different toad species. Male American (n = 9) and Gulf Coast (n = 7) toads were rotated systematically through a series of treatments. Urine was collected and evaluated for the presence of sperm at 0, 3, 7, 12, and 24 hours post-treatment. There were no statistical differences in spermiation induction or sperm characteristics between American and Gulf Coast toads after the treatments. Oral administration of 100 &mgr;g LHRH was occasionally successful in inducing spermiation, but results appeared largely unreliable. Ventral dermal application of 100 or 10 &mgr;g LHRH in 40% DMSO were more effective (P Zoo Biol 20:63-74, 2001. Copyright 2001 Wiley-Liss, Inc.

Acute gonadotropin-releasing hormone agonist treatment enhances extinction memory in male rats.

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Maeng, L Y; Taha, M B; Cover, K K; Glynn, S S; Murillo, M; Lebron-Milad, K; Milad, M R

2017-08-01

Leuprolide acetate (LEU), also known as Lupron, is commonly used to treat prostate cancer in men. As a gonadotropin-releasing hormone (GnRH) receptor agonist, it initially stimulates the release of gonadal hormones, testosterone (T) and estradiol. This surge eventually suppresses these hormones, preventing the further growth and spread of cancer cells. Individuals receiving this treatment often report anxiety and cognitive changes, but LEU's effects on the neural mechanisms that are involved in anxiety during the trajectory of treatment are not well known. In this study, we examined the acute effects of LEU on fear extinction, hypothesizing that increased T levels following a single administration of LEU will facilitate extinction recall by altering neuronal activity within the fear extinction circuitry. Two groups of naïve adult male rats underwent a 3-day fear conditioning, extinction, and recall experiment. The delayed group (n=15) received a single injection of vehicle or LEU (1.2mg/kg) 3weeks before behavioral testing. The acute group (n=25) received an injection one day after fear conditioning, 30min prior to extinction training. Following recall, the brains for all animals were collected for c-fos immunohistochemistry. Blood samples were also collected and assayed for T levels. Acute administration of LEU increased serum T levels during extinction training and enhanced extinction recall 24h later. This enhanced extinction memory was correlated with increased c-fos activity within the infralimbic cortex and amygdala, which was not observed in the delayed group. These results suggest that the elevation in T induced by acute administration of LEU can influence extinction memory consolidation, perhaps through modification of neuronal activity within the infralimbic cortex and amygdala. This may be an important consideration in clinical applications of LEU and its effects on anxiety and cognition. Copyright © 2017 Elsevier Ltd. All rights reserved.

Radioimmunoassay for 6-D-tryptophan analog of luteinizing hormone-releasing hormone: measurement of serum levels after administration of long-acting microcapsule formulations

International Nuclear Information System (INIS)

Mason-Garcia, M.; Vigh, S.; Comaru-Schally, A.M.; Redding, T.W.; Somogyvari-Vigh, A.; Horvath, J.; Schally, A.V.

1985-01-01

A sensitive and specific radioimmunoassay for [6-D-tryptophan]luteinizing hormone-releasing hormone ([D-Trp 6 ]LH-RH) was developed and used for following the rate of liberation of [D-Trp 6 ]LH-RH from a long-acting delivery systems based on a microcapsule formulation. Rabbit antibodies were generated against [D-Trp 6 ]LH-RH conjugated to bovine serum albumin with glutaraldehyde. Crossreactivity with LH-RH was less than 1%; there was no significant cross-reactivity with other peptides. The minimal detectable dose of [D-Trp 6 ]LH-RH was 2 pg per tube. In tra- and interassay coefficients of variation were 8% and 10%, respectively. The radioimmunoassay was suitable for direct determination of [D-Trp 6 ]LH-RH in serum, permitting the study of blood levels of the analog after single injections into normal men and after one-a-month administration of microcapsules to rats. In men, 90 min after subcutaneous injection of 250 μg of the peptide, serum [D-Trp 6 ]LH-RH rose to 6-12 ng/ml. Luteinizing hormone was increased 90 min and 24 hr after the administration of the analog. Several batches of microcapsules were tested in rats and the rate of release of [D-Trp 6 ]LH-RH was followed. The improved batch of microcapsules of [D-Trp 6 ]LH-RH increased serum concentrations of the analog for 30 days or longer after intramuscular injection

Effect of in ovo injection of corticotropin-releasing hormone on the timing of hatching in broiler chickens.

Science.gov (United States)

Watanabe, Yugo; Grommen, Sylvia V H; De Groef, Bert

2017-09-01

In chicken embryos, intravenous injection of corticotropin-releasing hormone (CRH) causes the release of both corticosteroids and thyroid hormones. These hormones initiate and enhance the hatching process, raising the possibility that CRH treatment of the late chicken embryo could accelerate hatching and/or decrease the spread of hatching. We performed a series of exploratory tests to investigate whether in ovo delivery methods of CRH other than intravenous injection that are more practical in a commercial setting, affect hatching time in broilers. Corticotropin-releasing hormone was injected into the air cell, albumen, or amniotic fluid of broiler breeder eggs, in the last week of embryonic development. Average incubation duration was significantly decreased by 22 h when 2 μg of CRH was injected into the air cell on embryonic day 18 (E18) of Cobb eggs. Acceleration of hatching (but only by 8 h) was also seen for Ross chicks when CRH was injected daily into the albumen between E10 and E18. However, repeats of both experiments did not show consistent effects of CRH on hatching time; in most experiments performed, CRH did not affect hatching time. We speculate that the effectiveness of CRH uptake via these delivery methods and/or the duration and magnitude of the thyroxine and corticosterone response to CRH is not sufficient to have a substantial effect on hatching time. We therefore conclude that in ovo CRH treatment does not seem a feasible option as a practical tool to increase hatchery productivity or to investigate the effects of CRH agonists and antagonists on hatching. © 2017 Poultry Science Association Inc.

Biosynthesis and the conjugation of magnetite nanoparticles with luteinizing hormone releasing hormone (LHRH)

Energy Technology Data Exchange (ETDEWEB)

Obayemi, J.D. [Department of Materials Science and Engineering, African University of Science and Technology (AUST) Abuja, Federal Capital Territory (Nigeria); Department of Materials Science and Engineering, Kwara State University, Malete, Kwara State (Nigeria); Dozie-Nwachukwu, S. [Department of Materials Science and Engineering, African University of Science and Technology (AUST) Abuja, Federal Capital Territory (Nigeria); Sheda Science and Technology Complex (SHESTCO) Abuja, Federal Capital Territory (Nigeria); Danyuo, Y. [Department of Materials Science and Engineering, African University of Science and Technology (AUST) Abuja, Federal Capital Territory (Nigeria); Department of Electronics and Electricals Engineering, Nigerian Turkish Nile University, Abuja (Nigeria); Odusanya, O.S. [Department of Materials Science and Engineering, African University of Science and Technology (AUST) Abuja, Federal Capital Territory (Nigeria); Sheda Science and Technology Complex (SHESTCO) Abuja, Federal Capital Territory (Nigeria); Anuku, N. [Department of Chemistry, Bronx Community College, New York, NY 10453 (United States); Princeton Institute of Science and Technology of Materials (PRISM), Princeton, NJ 08544 (United States); Malatesta, K. [Princeton Institute of Science and Technology of Materials (PRISM), Princeton, NJ 08544 (United States); Department of Mechanical and Aerospace Engineering, Princeton University, NJ 08544 (United States); Soboyejo, W.O., E-mail: soboyejo@princeton.edu [Department of Materials Science and Engineering, African University of Science and Technology (AUST) Abuja, Federal Capital Territory (Nigeria); Princeton Institute of Science and Technology of Materials (PRISM), Princeton, NJ 08544 (United States); Department of Mechanical and Aerospace Engineering, Princeton University, NJ 08544 (United States)

2015-01-01

This paper presents the results of an experimental study of the biosynthesis of magnetite nanoparticles (BMNPs) with particle sizes between 10 nm and 60 nm. The biocompatible magnetic nanoparticles are produced from Magnetospirillum magneticum (M.M.) bacteria that respond to magnetic fields. M.M. bacteria were cultured and used to synthesize magnetite nanoparticles. This was done in an enriched magnetic spirillum growth medium (EMSGM) at different pH levels. The nanoparticle concentrations were characterized with UV–Visible (UV–Vis) spectroscopy, while the particle shapes were elucidated via transmission electron microscopy (TEM). The structure of the particles was studied using X-ray diffraction (XRD), while the hydrodynamic radii, particle size distributions and polydispersity of the nanoparticles were characterized using dynamic light scattering (DLS). Carbodiimide reduction was also used to functionalize the BMNPs with a molecular recognition unit (luteinizing hormone releasing hormone, LHRH) that attaches specifically to receptors that are over-expressed on the surfaces of most breast cancer cell types. The resulting nanoparticles were examined using Fourier Transform Infrared (FTIR) spectroscopy and quantitative image analysis. The implications of the results are then discussed for the potential development of magnetic nanoparticles for the specific targeting and treatment of breast cancer. - Highlights: • Biosynthesis of MNPs with clinically relevant sizes between 10 and 60 nm. • New insights into the effects of pH and processing time on nanoparticle shapes and sizes. • Successful conjugation of biosynthesized magnetite nanoparticles to LHRH ligands. • Conjugated BMNPs that are monodispersed with potential biomedical relevance. • Magnetic properties of biosynthesized MNPs suggest potential for MRI enhancement.

Biosynthesis and the conjugation of magnetite nanoparticles with luteinizing hormone releasing hormone (LHRH)

International Nuclear Information System (INIS)

Obayemi, J.D.; Dozie-Nwachukwu, S.; Danyuo, Y.; Odusanya, O.S.; Anuku, N.; Malatesta, K.; Soboyejo, W.O.

2015-01-01

This paper presents the results of an experimental study of the biosynthesis of magnetite nanoparticles (BMNPs) with particle sizes between 10 nm and 60 nm. The biocompatible magnetic nanoparticles are produced from Magnetospirillum magneticum (M.M.) bacteria that respond to magnetic fields. M.M. bacteria were cultured and used to synthesize magnetite nanoparticles. This was done in an enriched magnetic spirillum growth medium (EMSGM) at different pH levels. The nanoparticle concentrations were characterized with UV–Visible (UV–Vis) spectroscopy, while the particle shapes were elucidated via transmission electron microscopy (TEM). The structure of the particles was studied using X-ray diffraction (XRD), while the hydrodynamic radii, particle size distributions and polydispersity of the nanoparticles were characterized using dynamic light scattering (DLS). Carbodiimide reduction was also used to functionalize the BMNPs with a molecular recognition unit (luteinizing hormone releasing hormone, LHRH) that attaches specifically to receptors that are over-expressed on the surfaces of most breast cancer cell types. The resulting nanoparticles were examined using Fourier Transform Infrared (FTIR) spectroscopy and quantitative image analysis. The implications of the results are then discussed for the potential development of magnetic nanoparticles for the specific targeting and treatment of breast cancer. - Highlights: • Biosynthesis of MNPs with clinically relevant sizes between 10 and 60 nm. • New insights into the effects of pH and processing time on nanoparticle shapes and sizes. • Successful conjugation of biosynthesized magnetite nanoparticles to LHRH ligands. • Conjugated BMNPs that are monodispersed with potential biomedical relevance. • Magnetic properties of biosynthesized MNPs suggest potential for MRI enhancement

Internalization and recycling of receptor-bound gonadotropin-releasing hormone agonist in pituitary gonadotropes

International Nuclear Information System (INIS)

Schvartz, I.; Hazum, E.

1987-01-01

The fate of cell surface gonadotropin-releasing hormone (GnRH) receptors on pituitary cells was studied utilizing lysosomotropic agents and monensin. Labeling of pituitary cells with a photoreactive GnRH derivative, [azidobenzoyl-D-Lys6]GnRH, revealed a specific band of Mr = 60,000. When photoaffinity-labeled cells were exposed to trypsin immediately after completion of the binding, the radioactivity incorporated into the Mr = 60,000 band decreased, with a concomitant appearance of a proteolytic fragment (Mr = 45,000). This fragment reflects cell surface receptors. Following GnRH binding, the hormone-receptor complexes underwent internalization, partial degradation, and recycling. The process of hormone-receptor complex degradation was substantially prevented by lysosomotropic agents, such as chloroquine and methylamine, or the proton ionophore, monensin. Chloroquine and monensin, however, did not affect receptor recycling, since the tryptic fragment of Mr = 45,000 was evident after treatment with these agents. This suggests that recycling of GnRH receptors in gonadotropes occurs whether or not the internal environment is acidic. Based on these findings, we propose a model describing the intracellular pathway of GnRH receptors

Effects of corticotropin-releasing hormone and its antagonist on the gene expression of gonadotrophin-releasing hormone (GnRH) and GnRH receptor in the hypothalamus and anterior pituitary gland of follicular phase ewes.

Science.gov (United States)

Ciechanowska, Magdalena; Łapot, Magdalena; Malewski, Tadeusz; Mateusiak, Krystyna; Misztal, Tomasz; Przekop, Franciszek

2011-01-01

There is no information in the literature regarding the effect of corticotropin-releasing hormone (CRH) on genes encoding gonadotrophin-releasing hormone (GnRH) and the GnRH receptor (GnRHR) in the hypothalamus or on GnRHR gene expression in the pituitary gland in vivo. Thus, the aim of the present study was to investigate, in follicular phase ewes, the effects of prolonged, intermittent infusion of small doses of CRH or its antagonist (α-helical CRH 9-41; CRH-A) into the third cerebral ventricle on GnRH mRNA and GnRHR mRNA levels in the hypothalamo-pituitary unit and on LH secretion. Stimulation or inhibition of CRH receptors significantly decreased or increased GnRH gene expression in the hypothalamus, respectively, and led to different responses in GnRHR gene expression in discrete hypothalamic areas. For example, CRH increased GnRHR gene expression in the preoptic area, but decreased it in the hypothalamus/stalk median eminence and in the anterior pituitary gland. In addition, CRH decreased LH secretion. Blockade of CRH receptors had the opposite effect on GnRHR gene expression. The results suggest that activation of CRH receptors in the hypothalamus of follicular phase ewes can modulate the biosynthesis and release of GnRH through complex changes in the expression of GnRH and GnRHR genes in the hypothalamo-anterior pituitary unit. © CSIRO 2011 Open Access

Dexamethasone suppression test

Science.gov (United States)

DST; ACTH suppression test; Cortisol suppression test ... During this test, you will receive dexamethasone. This is a strong man-made (synthetic) glucocorticoid medicine. Afterward, your blood is drawn ...

Effect of aging on GHRF-induced growth hormone release from anterior pituitary cells in primary culture

International Nuclear Information System (INIS)

Spik, K.W.; Boyd, R.L.; Sonntag, W.E.

1991-01-01

Five criteria were developed to validate the primary cell culture model for comparison of GRF-induced release of growth hormone in pituitary tissue from aging animals. Pituitaries from young (5-mo), middle-aged (14-mo), and old (24-mo) male Fischer 344 rats were dispersed using either trypsin/trypsin inhibitor or dispase and compared with respect to the number of pituitary cells recovered, cell viability, 3H-leucine incorporation into total protein, time course for recovery of optimal response to GRF, and the dose-relationship for GRF-induced release of growth hormone 2, 4, and 6 days after dispersal. Results indicated that direct comparison of cellular responses between tissues from young, middle-aged, and old rats in primary cell culture is confounded by variations in time for recovery of optimal responses, the effects of the enzymes used for dispersal, and the methods used to express the data

Involvement of phospholipase C and intracellular calcium signaling in the gonadotropin-releasing hormone regulation of prolactin release from lactotrophs of tilapia (Oreochromis mossambicus)

DEFF Research Database (Denmark)

Tipsmark, Christian Kølbæk; Weber, G M; Strom, C N

2005-01-01

Gonadotropin-releasing hormone (GnRH) is a potent stimulator of prolactin (PRL) secretion in various vertebrates including the tilapia, Oreochromis mossambicus. The mechanism by which GnRH regulates lactotroph cell function is poorly understood. Using the advantageous characteristics of the teleost...

Effects of long-term treatment with growth hormone-releasing peptide-2 in the GHRH knockout mouse.

Science.gov (United States)

Alba, Maria; Fintini, Danilo; Bowers, Cyril Y; Parlow, A F; Salvatori, Roberto

2005-11-01

Growth hormone (GH) secretagogues (GHS) stimulate GH secretion in vivo in humans and in animals. They act on the ghrelin receptor, expressed in both the hypothalamus and the pituitary. It is unknown whether GHSs act predominantly by increasing the release of hypothalamic GH-releasing hormone (GHRH) or by acting directly on the somatotroph cells. We studied whether a potent GHS could stimulate growth in the absence of endogenous GHRH. To this end, we used GHRH knockout (GHRH-KO) mice. These animals have proportionate dwarfism due to severe GH deficiency (GHD) and pituitary hypoplasia due to reduced somatotroph cell mass. We treated male GHRH-KO mice for 6 wk (from week 1 to week 7 of age) with GH-releasing peptide-2 (GHRP-2, 10 microg s.c. twice a day). Chronic treatment with GHRP-2 failed to stimulate somatotroph cell proliferation and GH secretion and to promote longitudinal growth. GHRP-2-treated mice showed an increase in total body weight compared with placebo-treated animals, due to worsening of the body composition alterations typical of GHD animals. These data demonstrate that GHRP-2 failed to reverse the severe GHD caused by lack of GHRH.

Longstanding refractory pseudophakic cystoid macular edema resolved using intravitreal 0.7 mg dexamethasone implants

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Brynskov T

2013-06-01

Full Text Available Troels Brynskov,1,2 Caroline Schmidt Laugesen,1 Jakob Halborg,1 Henrik Kemp,1 Torben Lykke Sørensen1,21Department of Ophthalmology, Copenhagen University Hospital Roskilde, Roskilde, Denmark; 2Faculty of Health Sciences, University of Copenhagen, Copenhagen, DenmarkBackground: Refractory pseudophakic cystoid macular edema (PCME following cataract surgery has long posed a challenge to clinicians, but intravitreal injections with a sustained delivery 0.7 mg dexamethasone implant has emerged as a promising therapy for this condition.Objective: To present a case of longstanding and refractory PCME with complete remission through 189 days of follow-up after two successive injections with intravitreal dexamethasone implants.Case report: A 59-year-old male had experienced metamorphopsia for approximately 4 years and had been diagnosed with PCME 15 months earlier. Since the time of the diagnosis, the condition had been refractory to both subtenon triamcinolone acetonide and a total of five injections with intravitreal ranibizumab. After the last injection with ranibizumab, central subfield mean thickness was 640 µm, and the best corrected visual acuity was 78 Early Treatment Diabetic Retinopathy Study letters. Following an intravitreal injection with a dexamethasone implant, the macular edema resolved at the next follow-up. The macular edema returned 187 days after the first injection and was treated with another intravitreal dexamethasone implant. Again, the macular edema subsided completely, and best corrected visual acuity improved to 84 Early Treatment Diabetic Retinopathy Study letters, a condition which was maintained through an additional 189 days of follow-up.Conclusion: Chronic PCME is traditionally a difficult condition to treat, but we are encouraged by the optimal response experienced with intravitreal sustained release dexamethasone implants in our patient whose longstanding PCME had been refractory to previous treatments with both

Dexamethasone rapidly increases GABA release in the dorsal motor nucleus of the vagus via retrograde messenger-mediated enhancement of TRPV1 activity.

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Andrei V Derbenev

Full Text Available Glucocorticoids influence vagal parasympathetic output to the viscera via mechanisms that include modulation of neural circuitry in the dorsal vagal complex, a principal autonomic regulatory center. Glucocorticoids can modulate synaptic neurotransmitter release elsewhere in the brain by inducing release of retrograde signalling molecules. We tested the hypothesis that the glucocorticoid agonist dexamethasone (DEX modulates GABA release in the rat dorsal motor nucleus of the vagus (DMV. Whole-cell patch-clamp recordings revealed that DEX (1-10 µM rapidly (i.e. within three minutes increased the frequency of tetrodotoxin-resistant, miniature IPSCs (mIPSCs in 67% of DMV neurons recorded in acutely prepared slices. Glutamate-mediated mEPSCs were also enhanced by DEX (10 µM, and blockade of ionotropic glutamate receptors reduced the DEX effect on mIPSC frequency. Antagonists of type I or II corticosteroid receptors blocked the effect of DEX on mIPSCs. The effect was mimicked by application of the membrane-impermeant BSA-conjugated DEX, and intracellular blockade of G protein function with GDP βS in the recorded cell prevented the effect of DEX. The enhancement of GABA release was blocked by the TRPV1 antagonists, 5'-iodoresiniferatoxin or capsazepine, but was not altered by the cannabinoid type 1 receptor antagonist AM251. The DEX effect was prevented by blocking fatty acid amide hydrolysis or by inhibiting anandamide transport, implicating involvement of the endocannabinoid system in the response. These findings indicate that DEX induces an enhancement of GABA release in the DMV, which is mediated by activation of TRPV1 receptors on afferent terminals. The effect is likely induced by anandamide or other 'endovanilloid', suggesting activation of a local retrograde signal originating from DMV neurons to enhance synaptic inhibition locally in response to glucocorticoids.

Zebrafish adult-derived hypothalamic neurospheres generate gonadotropin-releasing hormone (GnRH neurons

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Christian Cortés-Campos

2015-09-01

Full Text Available Gonadotropin-releasing hormone (GnRH is a hypothalamic decapeptide essential for fertility in vertebrates. Human male patients lacking GnRH and treated with hormone therapy can remain fertile after cessation of treatment suggesting that new GnRH neurons can be generated during adult life. We used zebrafish to investigate the neurogenic potential of the adult hypothalamus. Previously we have characterized the development of GnRH cells in the zebrafish linking genetic pathways to the differentiation of neuromodulatory and endocrine GnRH cells in specific regions of the brain. Here, we developed a new method to obtain neural progenitors from the adult hypothalamus in vitro. Using this system, we show that neurospheres derived from the adult hypothalamus can be maintained in culture and subsequently differentiate glia and neurons. Importantly, the adult derived progenitors differentiate into neurons containing GnRH and the number of cells is increased through exposure to either testosterone or GnRH, hormones used in therapeutic treatment in humans. Finally, we show in vivo that a neurogenic niche in the hypothalamus contains GnRH positive neurons. Thus, we demonstrated for the first time that neurospheres can be derived from the hypothalamus of the adult zebrafish and that these neural progenitors are capable of producing GnRH containing neurons.

Fresh versus frozen embryo transfer after gonadotropin-releasing hormone agonist trigger in gonadotropin-releasing hormone antagonist cycles among high responder women: A randomized, multi-center study

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Abbas Aflatoonian

2018-02-01

Full Text Available Background: The use of embryo cryopreservation excludes the possible detrimental effects of ovarian stimulation on the endometrium, and higher reproductive outcomes following this policy have been reported. Moreover, gonadotropin-releasing hormone agonist trigger in gonadotropin-releasing hormone (GnRH antagonist cycles as a substitute for standard human chorionic gonadotropin trigger, minimizes the risk of ovarian hyperstimulation syndrome (OHSS in fresh as well as frozen embryo transfer cycles (FET. Objective: To compare the reproductive outcomes and risk of OHSS in fresh vs frozen embryo transfer in high responder patients, undergoing in vitro fertilization triggered with a bolus of GnRH agonist. Materials and Methods: In this randomized, multi-centre study, 121 women undergoing FET and 119 women undergoing fresh ET were investigated as regards clinical pregnancy as the primary outcome and the chemical pregnancy, live birth, OHSS development, and perinatal data as secondary outcomes. Results: There were no significant differences between FET and fresh groups regarding chemical (46.4% vs. 40.2%, p=0.352, clinical (35.8% vs. 38.3%, p=0.699, and ongoing (30.3% vs. 32.7%, p=0.700 pregnancy rates, also live birth (30.3% vs. 29.9%, p=0.953, perinatal outcomes, and OHSS development (35.6% vs. 42.9%, p=0.337. No woman developed severe OHSS and no one required admission to hospital. Conclusion: Our findings suggest that GnRHa trigger followed by fresh transfer with modified luteal phase support in terms of a small human chorionic gonadotropin bolus is a good strategy to secure good live birth rates and a low risk of clinically relevant OHSS development in in vitro fertilization patients at risk of OHSS.

VENOUS SAMPLING FOR CUSHING DISEASE: COMPARISON OF INTERNAL JUGULAR VEIN AND INFERIOR PETROSAL SINUS SAMPLING.

Science.gov (United States)

Radvany, Martin G; Quinones-Hinojosa, Alfredo; Gallia, Gary L; Wand, Gary S; Salvatori, Roberto

2016-09-01

Because magnetic resonance imaging (MRI) fails to detect many adrenocorticotropic hormone (ACTH)-secreting pituitary adenomas, inferior petrosal sinus sampling (IPSS) is considered the gold standard to differentiate Cushing disease (CD) from ectopic ACTH secretion syndrome (EAS). Some authors have suggested internal jugular vein sampling (IJVS) as an alternative to IPSS. We simultaneously compared IJVS to IPSS in 30 consecutive patients referred for ACTH-dependent Cushing syndrome and equivocal MRI exams. Five sites were simultaneously sampled in each patient (right and left IPS, right and left IJV, and femoral vein) before and after the administration of corticotrophin-releasing hormone or desmopressin. The test was considered consistent with CD when the IPS to peripheral ratio was >2 at baseline or >3 after stimulus and the IJV to peripheral ratio was >1.7 at baseline or >2 after stimulus. In 27 of 30 patients, IPSS results were consistent with a central source of ACTH. Two of the other 3 patients had EAS (one lung carcinoid and one occult), and 1 patient had pathology-proven CD. The sensitivity of IPSS was 96.4%. Only 64.2% of these patients had results meeting criteria for a central source of ACTH by IJVS criteria. Twenty patients with centralizing IPPS have undergone pituitary surgery. Of these, the central origin of excessive ACTH was confirmed with certainty in 16 patients. Among these 16 patients, the IPSS sensitivity was 93.8%, whereas 5 patients had false-negative IJVS (68.7% sensitivity). These results do not support the routine use of IJVS in establishing if the pituitary is the source of excessive ACTH. ACTH = adrenocorticotropic hormone CD = Cushing disease CRH = corticotrophin-releasing hormone CS = Cushing syndrome DDAVP = desmopressin EAS = ectopic ACTH secretion IJVS = internal jugular vein sampling IPSS = inferior petrosal sinus sampling JVS = jugular venous sampling MRI = magnetic resonance imaging.

Interaction between prenatal pesticide exposure and a common polymorphism in the PON1 gene on DNA methylation in genes associated with cardio-metabolic disease risk-an exploratory study

DEFF Research Database (Denmark)

Declerck, Ken; Remy, Sylvie; Wohlfahrt-Veje, Christine

2017-01-01

BACKGROUND: Prenatal environmental conditions may influence disease risk in later life. We previously found a gene-environment interaction between the paraoxonase 1 (PON1) Q192R genotype and prenatal pesticide exposure leading to an adverse cardio-metabolic risk profile at school age. However...... was observed in prenatally pesticide exposed children carrying the PON1 192R-allele. Differentially methylated genes were enriched in several neuroendocrine signaling pathways including dopamine-DARPP32 feedback (appetite, reward pathways), corticotrophin releasing hormone signaling, nNOS, neuregulin signaling...

Effects of graded doses of goitrin, a goitrogen in rapeseed, on synthesis and release of thyroid hormone in chicks

International Nuclear Information System (INIS)

Akiba, Yukio; Matsumoto, Tatsuro

1977-01-01

Intrathyroidal metabolism in synthesis and release of thyroid hormone was investigated in chicks administered three different levels of goitrin (0.0125, 0.025 and 0.05% in the diet) for 14 days. Thyroid glands were enlarged to 2-5 times as large as that of the control in proportion to the goitrin content of the diet. Typical high radioiodine uptake goiter was demonstrated in the goitrin-administered chicks. Total thyroid 125 I content increased about twice as much as that of the control in the goitrin-administered chicks though it was depressed in 0.0065% PUT-administered chicks. Decrease of plasma PB 125 I (approximately a half of the control) was ascertained by the estimation of plasma thyroxine by radiostereoassay. In the intrathyroidal metabolism of iodine, synthesis of iodothyronines and iodination of MIT were suppressed by goitrin, but monoiodination of tyrosine was rather accelerated. The elevated ratio of thyroid iodothyronines/plasma PBI (1.5-1.7 times as much as that of the control) reveals that the depression of plasma level of thyroid hormone is more striking than the decrease in thyroid hormone in the gland in the goitrin-administered chicks. It is, therefore, suggested that goitrin has inhibitory effects not only on the biosynthesis of thyroid hormone in the gland but also on the release of thyroid hormone from the gland. (auth.)

Cocaine- and amphetamine-regulated transcript is present in hypothalamic neuroendocrine neurones and is released to the hypothalamic-pituitary portal circuit.

Science.gov (United States)

Larsen, P J; Seier, V; Fink-Jensen, A; Holst, J J; Warberg, J; Vrang, N

2003-03-01

Cocaine- and amphetamine-regulated transcript (CART) is present in a number of hypothalamic nuclei. Besides actions in circuits regulating feeding behaviour and stress responses, the hypothalamic functions of CART are largely unknown. We report that CART immunoreactivity is present in hypothalamic neuroendocrine neurones. Adult male rats received a systemic injection of the neuronal tracer Fluorogold (FG) 2 days before fixation, and subsequent double- and triple-labelling immunoflourescence analysis demonstrated that neuroendocrine CART-containing neurones were present in the anteroventral periventricular, supraoptic, paraventricular (PVN) and periventricular nuclei of the hypothalamus. In the PVN, CART-positive neuroendocrine neurones were found in all of cytoarchitectonically identified nuclei. In the periventricular nucleus, approximately one-third of somatostatin cells were also CART-immunoreactive. In the medial parvicellular subnucleus of the PVN, CART and FG coexisted with thyrotrophin-releasing hormone, whereas very few of the corticotrophin-releasing hormone containing cells were CART-immunoreactive. In the arcuate nucleus, CART was extensively colocalized with pro-opiomelanocortin in the ventrolateral part, but completely absent from neuroendocrine neurones of the dorsomedial part. To assess the possible role of CART as a hypothalamic-releasing factor, immunoreactive CART was measured in blood samples from the long portal vessels connecting the median eminence with the anterior pituitary gland. Adult male rats were anaesthetized and the infundibular stalk exposed via a transpharyngeal approach. The long portal vessels were transected and blood collected in 30-min periods (one prestimulatory and three poststimulatory periods). Compared to systemic venous plasma samples, baseline concentrations of immunoreactive CART were elevated in portal plasma. Exposure to sodium nitroprusside hypotension triggered a two-fold elevation of portal CART42

Analysis of renal impairment in MM-003, a phase III study of pomalidomide + low - dose dexamethasone versus high - dose dexamethasone in refractory or relapsed and refractory multiple myeloma

Science.gov (United States)

Weisel, Katja C.; Dimopoulos, Meletios A.; Moreau, Philippe; Lacy, Martha Q.; Song, Kevin W.; Delforge, Michel; Karlin, Lionel; Goldschmidt, Hartmut; Banos, Anne; Oriol, Albert; Alegre, Adrian; Chen, Christine; Cavo, Michele; Garderet, Laurent; Ivanova, Valentina; Martinez-Lopez, Joaquin; Knop, Stefan; Yu, Xin; Hong, Kevin; Sternas, Lars; Jacques, Christian; Zaki, Mohamed H.; Miguel, Jesus San

2016-01-01

Pomalidomide + low-dose dexamethasone is effective and well tolerated for refractory or relapsed and refractory multiple myeloma after bortezomib and lenalidomide failure. The phase III trial MM-003 compared pomalidomide + low-dose dexamethasone with high-dose dexamethasone. This subanalysis grouped patients by baseline creatinine clearance ≥ 30 − < 60 mL/min (n=93, pomalidomide + low-dose dexamethasone; n=56, high-dose dexamethasone) or ≥ 60 mL/min (n=205, pomalidomide + low-dose dexamethasone; n=93, high-dose dexamethasone). Median progression-free survival was similar for both subgroups and favored pomalidomide + low-dose dexamethasone versus high-dose dexamethasone: 4.0 versus 1.9 months in the group with baseline creatinine clearance ≥ 30 − < 60 mL/min (P<0.001) and 4.0 versus 2.0 months in the group with baseline creatinine clearance ≥ 60 mL/min (P<0.001). Median overall survival for pomalidomide + low-dose dexamethasone versus high-dose dexamethasone was 10.4 versus 4.9 months (P=0.030) and 15.5 versus 9.2 months (P=0.133), respectively. Improved renal function, defined as an increase in creatinine clearance from < 60 to ≥ 60 mL/min, was similar in pomalidomide + low-dose dexamethasone and high-dose dexamethasone patients (42% and 47%, respectively). Improvement in progression-free and overall survival in these patients was comparable with that in patients without renal impairment. There was no increase in discontinuations of therapy, dose modifications, and adverse events in patients with moderate renal impairment. Pomalidomide at a starting dose of 4 mg + low-dose dexamethasone is well tolerated in patients with refractory or relapsed and refractory multiple myeloma, and of comparable efficacy if moderate renal impairment is present. This trial was registered with clinicaltrials.gov identifier 01311687 and EudraCT identifier 2010-019820-30. PMID:27081177

Is it really a matter of simple dualism? Corticotropin-releasing factor receptors in body and mental health

Directory of Open Access Journals (Sweden)

Donny eJanssen

2013-03-01

Full Text Available Physiological responses to stress coordinated by the hypothalamo-pituitary-adrenal (HPA- axis are concerned with maintaining homeostasis in the presence of real or perceived challenges. Regulators of this axis are corticotrophin releasing hormone (CRF and CRF related neuropeptides, including urocortins (Ucn 1, 2 and 3. They mediate their actions by binding to CRF receptors (CRFR 1 and 2, which are located in several stress related brain regions. The prevailing theory has been that the initiation of and the recovery from an elicited stress response is coordinated by two elements, viz. the (mainly opposing, but well balanced actions of CRFR1 and CRFR2. Such a dualistic view suggests that CRF/CRFR1 controls the initiation of, and urocortins/CRFR2 mediate the recovery from stress to maintain body and mental health. Consequently, failed adaptation to stress can lead to neuropathology, including anxiety and depression. Recent literature, however, challenges such dualistic and complementary actions of CRFR1 and CRFR2, and suggests that stress recruits CRF system components in a brain area and neuron specific manner to promote adaptation as conditions dictate.

A comparison of dexamethasone, ondansetron, and dexamethasone plus ondansetron as prophylactic antiemetic and antipruritic therapy in patients receiving intrathecal morphine for major orthopedic surgery.

LENUS (Irish Health Repository)

Szarvas, Szilvia

2012-02-03

In a prospective, double-blinded, randomized trial, we evaluated the efficacy of IV (a) dexamethasone 8 mg, (b) ondansetron 8 mg, and (c) dexamethasone 8 mg plus ondansetron 4 mg for the prevention of postoperative nausea, vomiting (PONV), and pruritus in 130 (ASA physical status I to III) patients undergoing elective major orthopedic surgery after spinal anesthesia with hyperbaric 0.5% bupivacaine and intrathecal morphine. After spinal anesthesia, patients were randomized to one of three groups. Failure of PONV prophylaxis in the 24-h postoperative period occurred more frequently in patients who received dexamethasone alone (29 of 40; 73%) compared with those who received either ondansetron alone (23 of 47; 49%) (P = 0.02) or dexamethasone plus ondansetron together (19 of 43; 44%)(P = 0.01). There was no difference in the incidence of failure of prophylaxis of pruritus (70%, 72%, and 70% in dexamethasone 8 mg, ondansetron 8 mg, and dexamethasone 8 mg plus ondansetron 4 mg, respectively) (P > 0.1) in the 24-h postoperative period. We conclude that the administration of dexamethasone 8 mg with ondansetron 4 mg has no added benefit compared with ondansetron 8 mg alone in the prophylaxis of PONV and pruritus. IMPLICATIONS: Postoperative nausea and vomiting (PONV) and pruritus are common side effects after spinal opioid administration. In this study, dexamethasone 8 mg plus ondansetron 4 mg was as effective as ondansetron 8 mg. The administration of dexamethasone alone was associated with a frequent incidence of PONV, demonstrating a lack of efficacy. This has important cost implications.

Oval pulsed high-dose dexamethasone for myositis

NARCIS (Netherlands)

Hoogendijk, JE; Wokke, JHJ; de Visser, M

To study the short-term effect of oral pulsed high-dose dexamethasone for myositis we treated eight newly diagnosed patients with three 28-day cycles of oral dexamethasone. Primary outcome measures were muscle strength, pain, and serum creatine kinase activity. Sis patients responded. Side effects

Oral pulsed high-dose dexamethasone for myositis

NARCIS (Netherlands)

van der Meulen, M. F.; Hoogendijk, J. E.; Wokke, J. H.; de Visser, M.

2000-01-01

To study the short-term effect of oral pulsed high-dose dexamethasone for myositis we treated eight newly diagnosed patients with three 28-day cycles of oral dexamethasone. Primary outcome measures were muscle strength, pain, and serum creatine kinase activity. Six patients responded. Side effects

Adult Coats’ Disease Successfully Managed with the Dexamethasone Intravitreal Implant (Ozurdex® Combined with Retinal Photocoagulation

Directory of Open Access Journals (Sweden)

Sebastián Martínez-Castillo

2012-03-01

Full Text Available Purpose: To report a case of Coats’ disease managed with the dexamethasone intravitreal implant Ozurdex® (Allergan, Inc., Irvine, Calif., USA combined with retinal photocoagulation. Methods: A 46-year-old female with 20/200 visual acuity was diagnosed with Coats’ disease with secondary retinal vasoproliferative tumor. An initial approach was performed with an intravitreal injection of the sustained-release dexamethasone implant Ozurdex. After reattachment of the retina, the telangiectatic vessels were treated with laser photocoagulation. Results: The patient’s visual acuity improved to 20/25 after the intravitreal Ozurdex. No further recurrences of exudation were evident through the 12-month follow-up. Conclusions: Ozurdex may be an effective initial therapeutic approach for Coats’ disease with immediate anatomical response and visual improvement.

Thyroid hormone stimulation of phosphatidylcholine synthesis in cultured fetal rabbit lung.

OpenAIRE

Ballard, P L; Hovey, M L; Gonzales, L K

1984-01-01

To investigate the mechanism of thyroid hormone action on pulmonary surfactant synthesis, we characterized the effect of triiodothyronine on phosphatidylcholine synthesis in cultured fetal rabbit lung. Since glucocorticoids stimulate surfactant synthesis and reduce the incidence of Respiratory Distress Syndrome in premature infants, we also examined the interaction of triiodothyronine and dexamethasone. The rate of choline incorporation into phosphatidylcholine was determined in organ culture...

Gonadotrophin releasing hormone antagonist in IVF/ICSI

Directory of Open Access Journals (Sweden)

M S Kamath

2008-01-01

Full Text Available Objective : To study the efficacy of gonadotrophin releasing hormone (GnRH antagonist in In-vitro-fertilization/Intracytoplasmic sperm injection (IVF/ICSI cycles. Type of Study : Observational study. Setting: Reproductive Medicine Unit, Christian Medical College Hospital, Vellore, Tamil Nadu. Materials and Methods: GnRH antagonists were introduced into our practice in November 2005. Fifty-two women undergoing the antagonist protocol were studied and information gathered regarding patient profile, treatment parameters (total gonadotrophin dosage, duration of treatment, and oocyte yield, and outcomes in terms of embryological parameters (cleavage rates, implantation rates and clinical pregnancy. These parameters were compared with 121 women undergoing the standard long protocol. The costs between the two groups were also compared. Main Outcome : Clinical pregnancy rate. Results : The clinical pregnancy rate per embryo transfer in the antagonist group was 31.7% which was comparable to the clinical pregnancy rate in women undergoing the standard long protocol (30.63%. The costs between the two groups were comparable. Conclusions : GnRH antagonist protocol was found to be effective and comparable to the standard long protocol regimen. In addition it was simple, convenient, and patient friendly.

Isotocin Regulates Growth Hormone but Not Prolactin Release From the Pituitary of Ricefield Eels

Directory of Open Access Journals (Sweden)

Wei Yang

2018-04-01

Full Text Available The neurohypophyseal hormone oxytocin (Oxt has been shown to stimulate prolactin (Prl synthesis and release from the adenohypophysis in rats. However, little is known about the functional roles of Oxt-like neuropeptides in the adenohypophysis of non-mammalian vertebrates. In this study, cDNAs encoding ricefield eel oxytocin-like receptors (Oxtlr, namely isotocin (Ist receptor 1 (Istr1 and 2 (Istr2, were isolated and specific antisera were generated, respectively. RT-PCR and Western blot analysis detected the presence of both Istr1 and Istr2 in the brain and pituitary, but differential expression in some peripheral tissues, including the liver and kidney, where only Istr1 was detected. In the pituitary, immunoreactive Istr1 and Istr2 were differentially distributed, with the former mainly in adenohypophyseal cell layers adjacent to the neurohypophysis, whereas the latter in peripheral areas of the adenohypophysis. Double immunofluorescent images showed that immunostaining of Istr1, but not Istr2 was localized to growth hormone (Gh cells, but neither of them was expressed in Prl cells. Ist inhibited Gh release in primary pituitary cells of ricefield eels and increased Gh contents in the pituitary gland of ricefield eels at 6 h after in vivo administration. Ist inhibition of Gh release is probably mediated by cAMP, PKC/DAG, and IP3/Ca2+ pathways. In contrast, Ist did not affect either prl gene expression or Prl contents in primary pituitary cells. Results of this study demonstrated that Ist may not be involved in the regulation of Prl, but inhibit Gh release via Istr1 rather than Istr2 in ricefield eels, and provided evidence for the direct regulation of Gh cells by oxytocin-like neuropeptides in the pituitary of non-mammalian vertebrates.

Isotocin Regulates Growth Hormone but Not Prolactin Release From the Pituitary of Ricefield Eels

Science.gov (United States)

Yang, Wei; Zhang, Ning; Shi, Boyang; Zhang, Shen; Zhang, Lihong; Zhang, Weimin

2018-01-01

The neurohypophyseal hormone oxytocin (Oxt) has been shown to stimulate prolactin (Prl) synthesis and release from the adenohypophysis in rats. However, little is known about the functional roles of Oxt-like neuropeptides in the adenohypophysis of non-mammalian vertebrates. In this study, cDNAs encoding ricefield eel oxytocin-like receptors (Oxtlr), namely isotocin (Ist) receptor 1 (Istr1) and 2 (Istr2), were isolated and specific antisera were generated, respectively. RT-PCR and Western blot analysis detected the presence of both Istr1 and Istr2 in the brain and pituitary, but differential expression in some peripheral tissues, including the liver and kidney, where only Istr1 was detected. In the pituitary, immunoreactive Istr1 and Istr2 were differentially distributed, with the former mainly in adenohypophyseal cell layers adjacent to the neurohypophysis, whereas the latter in peripheral areas of the adenohypophysis. Double immunofluorescent images showed that immunostaining of Istr1, but not Istr2 was localized to growth hormone (Gh) cells, but neither of them was expressed in Prl cells. Ist inhibited Gh release in primary pituitary cells of ricefield eels and increased Gh contents in the pituitary gland of ricefield eels at 6 h after in vivo administration. Ist inhibition of Gh release is probably mediated by cAMP, PKC/DAG, and IP3/Ca2+ pathways. In contrast, Ist did not affect either prl gene expression or Prl contents in primary pituitary cells. Results of this study demonstrated that Ist may not be involved in the regulation of Prl, but inhibit Gh release via Istr1 rather than Istr2 in ricefield eels, and provided evidence for the direct regulation of Gh cells by oxytocin-like neuropeptides in the pituitary of non-mammalian vertebrates.

Galanin does not affect the growth hormone-releasing hormone-stimulated growth hormone secretion in patients with hyperthyroidism.

Science.gov (United States)

Giustina, A; Bussi, A R; Legati, F; Bossoni, S; Licini, M; Schettino, M; Zuccato, F; Wehrenberg, W B

1992-12-01

Patients with hyperthyroidism have reduced spontaneous and stimulated growth hormone (GH) secretion. The aim of our study was to evaluate the effects of galanin, a novel neuropeptide which stimulates GH secretion in man, on the GH response to GHRH in patients with hyperthyroidism. Eight untreated hyperthyroid patients with Graves' disease (6F, 2M, aged 25-50 years) and six healthy volunteers (3F, 3M, aged 27-76 years) underwent from -10 to 30 min in random order: (i) porcine galanin, iv, 500 micrograms in 100 ml saline; or (ii) saline, iv, 100 ml. A bolus of human GHRH(1-29)NH2, 100 micrograms, was injected iv at 0 min. Hyperthyroid patients showed blunted GH peaks after GHRH+saline (10.2 +/- 2.5 micrograms/l) compared to normal subjects (20.7 +/- 4.8 micrograms/l, p hyperthyroid subjects (12.5 +/- 3 micrograms/l) compared to normal subjects (43.8 +/- 6 micrograms/l, p hyperthyroidism suggests that hyperthyroxinemia may either increase the somatostatin release by the hypothalamus or directly affect the pituitary GH secretory capacity.

Dominant dwarfism in transgenic rats by targeting human growth hormone (GH) expression to hypothalamic GH-releasing factor neurons.

OpenAIRE

Flavell, D M; Wells, T; Wells, S E; Carmignac, D F; Thomas, G B; Robinson, I C

1996-01-01

Expression of human growth hormone (hGH) was targeted to growth hormone-releasing (GRF) neurons in the hypothalamus of transgenic rats. This induced dominant dwarfism by local feedback inhibition of GRF. One line, bearing a single copy of a GRF-hGH transgene, has been characterized in detail, and has been termed Tgr (for Transgenic growth-retarded). hGH was detected by immunocytochemistry in the brain, restricted to the median eminence of the hypothalamus. Low levels were also detected in the...

CORTICOTROPIN-RELEASING HORMONE MICROINFUSION IN THE CENTRAL AMYGDALA DIMINISHES A CARDIAC PARASYMPATHETIC OUTFLOW UNDER STRESS-FREE CONDITIONS

NARCIS (Netherlands)

WIERSMA, A; BOHUS, B; KOOLHAAS, JM

1993-01-01

The central nucleus of the amygdala (CeA) is known to be involved in the regulation of autonomic, neuroendocrine and behavioural responses in stress situations. The CeA contains large numbers of corticotropin-releasing hormone (CRH) cell bodies. Neuroanatomical studies revealed that the majority of

Differential contribution of CBP:CREB binding to corticotropin-releasing hormone expression in the infant and adult hypothalamus

NARCIS (Netherlands)

Cope, J.L.; Regev, L.; Chen, Y.; Korosi, A.; Rice, C.J.; Ji, S.; Rogge, G.A.; Wood, M.A.; Baram, T.Z.

2014-01-01

Corticotropin-releasing hormone (CRH) contributes crucially to the regulation of central and peripheral responses to stress. Because of the importance of a finely-tuned stress system, CRH expression is tightly regulated in an organ- and brain region-specific manner. Thus, in hypothalamus, CRH is

[The changes of ghrelin, growth hormone, growth hormone releasing hormone and their clinical significances in patients with chronic obstructive pulmonary disease].

Science.gov (United States)

Xu, Zhi-song; Bao, Zi-yu; Wang, Zhi-ying; Yang, Guo-jun; Zhu, Dong-fang; Zhang, Li; Tan, Rong-mei

2012-07-01

To investigate the changes of plasma ghrelin, growth hormone (GH) and growth hormone releasing hormone (GHRH) and gastric ghrelin in patients with chronic obstructive pulmonary disease (COPD) and to explore their clinical significances. Plasma ghrelin, GH, GHRH, TNFα, IL-6 and C reactive protein (CRP) were measured in 40 COPD patients and 20 controls with chronic bronchitis. Correlated factors of plasma ghrelin, TNFα, IL-6, CRP were analyzed. Body composition was assessed with bioelectrical impedance analysis. The expression of gastric ghrelin in patients with COPD was detected. Plasma ghrelin was higher in the underweight patients than in the normal weight patients and in the controls [(1.78 ± 0.46) ng/L, (1.39 ± 0.46) ng/L, (1.36 ± 0.39) ng/L, respectively]. Plasma GH was lower in the underweight patients than in the normal weight patients and in the controls [(4.12 ± 0.83) µg/L, (5.17 ± 0.72)µg/L, (6.49 ± 1.13) µg/L, respectively]. Plasma GHRH was lower in the underweight patients than in the normal weight patients and in the controls [(20.43 ± 4.41) ng/L, (23.47 ± 3.97) ng/L, (27.48 ± 10.06) ng/L, respectively]. Plasma ghrelin was higher in the underweight patients than in the controls (P 0.05). Plasma ghrelin was positively correlated with TNFα and IL-6 in the underweight patients. The gastric expression of ghrelin showed no evident difference between the patients with COPD and the controls. The plasma GH in COPD patients may not be correlated with ghrelin. The plasma ghrelin level may be a useful indicator for malnutrition in COPD patients. Plasma ghrelin might be involved in the pathogenesis of CODP by affecting the body energy metabolism.

Stress sensitivity and resilience in the chronic mild stress rat model of depression; an in situ hybridization study

DEFF Research Database (Denmark)

Bergström, A; Jayatissa, M N; Mørk, A

2008-01-01

in stress. Moreover, in the CA3 we found downregulation of vascular endothelial growth factor (VEGF) mRNA in the CMS sensitive group. Downregulation of VEGF suggests impaired hippocampal function, caused by loss of trophic factor neuroprotective support, as part of a previously uncharacterized mechanism...... for development of anhedonia. CMS induced anhedonia was not related to mRNA expression differences of the dopamine receptors D(1) and D(2), enkephalin, dynorphin, the NMDA receptor subtype NR2B in the ventral striatum, BDNF expression in the dentate gyrus, nor corticotrophin releasing hormone (CRH) and arginine...

Growth hormone releasing hormone (GHRH) signaling modulates intermittent hypoxia-induced oxidative stress and cognitive deficits in mouse.

Science.gov (United States)

Nair, Deepti; Ramesh, Vijay; Li, Richard C; Schally, Andrew V; Gozal, David

2013-11-01

Intermittent hypoxia (IH) during sleep, such as occurs in obstructive sleep apnea (OSA), leads to degenerative changes in the hippocampus, and is associated with spatial learning deficits in adult mice. In both patients and murine models of OSA, the disease is associated with suppression of growth hormone (GH) secretion, which is actively involved in the growth, development, and function of the central nervous system (CNS). Recent work showed that exogenous GH therapy attenuated neurocognitive deficits elicited by IH during sleep in rats. Here, we show that administration of the Growth Hormone Releasing Hormone (GHRH) agonist JI-34 attenuates IH-induced neurocognitive deficits, anxiety, and depression in mice along with reduction in oxidative stress markers such as MDA and 8-hydroxydeoxyguanosine, and increases in hypoxia inducible factor-1α DNA binding and up-regulation of insulin growth factor-1 and erythropoietin expression. In contrast, treatment with a GHRH antagonist (MIA-602) during intermittent hypoxia did not affect any of the IH-induced deleterious effects in mice. Thus, exogenous GHRH administered as the formulation of a GHRH agonist may provide a viable therapeutic intervention to protect IH-vulnerable brain regions from OSA-associated neurocognitive dysfunction. Sleep apnea, characterized by chronic intermittent hypoxia (IH), is associated with substantial cognitive and behavioral deficits. Here, we show that administration of a GHRH agonist (JI-34) reduces oxidative stress, increases both HIF-1α nuclear binding and downstream expression of IGF1 and erythropoietin (EPO) in hippocampus and cortex, and markedly attenuates water maze performance deficits in mice exposed to intermittent hypoxia during sleep. © 2013 International Society for Neurochemistry.

Gastrointestinal hormones and their targets

DEFF Research Database (Denmark)

Rehfeld, Jens F.

2014-01-01

Gastrointestinal hormones are peptides released from endocrine cells and neurons in the digestive tract. More than 30 hormone genes are currently known to be expressed in the gastrointestinal tract, which makes the gut the largest hormone producing organ in the body. Modern biology makes...... it feasible to conceive the hormones under five headings: The structural homology groups a majority of the hormones into nine families, each of which is assumed to originate from one ancestral gene. The individual hormone gene often has multiple phenotypes due to alternative splicing, tandem organization......, or differentiated maturation of the prohormone. By a combination of these mechanisms, more than 100 different hormonally active peptides are released from the gut. Gut hormone genes are also widely expressed in cells outside the gut, some only in extraintestinal endocrine cells and neurons but others also in other...

Effects of dexamethasone on brain edema

International Nuclear Information System (INIS)

Takemoto, Motohisa

1982-01-01

Experimental cerebral edema was produced on the right parietal lobe of Wistar male rats with a cold metal probe cooled by liquid nitrogen. Twenty hour later, 3 H-dexamethasone was either intramuscularly or intravenously injected into rats, estimated in the brain tissue by the liquid scintillation counting method. Edematous brain generally contained much higher 3 H-activity than the control. Furthermore, I.V. injection showed higher 3 H-activity than I.M injection in edematous and control brains at all times. For examination of the subcellular distribution of 3 H-dexamethasone in edematous brain, 3 H-activity was most strongly detected in the supernatant fraction (63%), followed by the heavy mitochondrial fraction (25.4%) and the nuclear fraction (8.4%). Although edematous brain tissue constantly demonstrated higher 3 H-activity than the control, its supernatant fraction conversely had less activity. As a next step, distribution of 3 H-dexamethasone in the supernatant fraction was studies. The result was that the high molecular weight fraction in the edematous brain showed higher radioactivity than the control. From these findings, unequivocal distribution of dexamethasone in the supernatant fraction of edematous brain tissue could be correlated with its biochemical action for preventing brain edema. (J.P.N.)

Fecal Glucocorticoid Analysis: Non-invasive Adrenal Monitoring in Equids.

Science.gov (United States)

Yarnell, Kelly; Purcell, Rebecca S; Walker, Susan L

2016-04-25

Adrenal activity can be assessed in the equine species by analysis of feces for corticosterone metabolites. During a potentially aversive situation, corticotrophin releasing hormone (CRH) is released from the hypothalamus in the brain. This stimulates the release of adrenocorticotrophic hormone (ACTH) from the pituitary gland, which in turn stimulates release of glucocorticoids from the adrenal gland. In horses the glucocorticoid corticosterone is responsible for several adaptations needed to support equine flight behaviour and subsequent removal from the aversive situation. Corticosterone metabolites can be detected in the feces of horses and assessment offers a non-invasive option to evaluate long term patterns of adrenal activity. Fecal assessment offers advantages over other techniques that monitor adrenal activity including blood plasma and saliva analysis. The non-invasive nature of the method avoids sampling stress which can confound results. It also allows the opportunity for repeated sampling over time and is ideal for studies in free ranging horses. This protocol describes the enzyme linked immunoassay (EIA) used to assess feces for corticosterone, in addition to the associated biochemical validation.

Does dexamethasone have a perineural mechanism of action?

DEFF Research Database (Denmark)

Jæger, P; Grevstad, Jens Ulrik; Koscielniak-Nielsen, Z J

2016-01-01

BACKGROUND: Dexamethasone prolongs block duration. Whether this is achieved via a peripheral or a central mechanism of action is unknown. We hypothesized that perineural dexamethasone added as an adjuvant to ropivacaine prolongs block duration compared with ropivacaine alone, by a locally mediated...... effect when controlled for a systemic action. METHODS: We performed a paired, blinded, randomized trial, including healthy men. All subjects received bilateral blocks of the saphenous nerve with ropivacaine 0.5%, 20 ml mixed with dexamethasone 2 mg in one leg and saline in the other, according...

Sexual dimorphism of stress response and immune/ inflammatory reaction: the corticotropin releasing hormone perspective

OpenAIRE

Vamvakopoulos, Nicholas V.

1995-01-01

This review higlghts key aspects of corticotropin releasing hormone (CRH) biology of potential relevance to the sexual dimorphism of the stress response and immune/inflammatory reaction, and introduces two important new concepts based on the regulatory potential of the human (h) CRH gene: (1) a proposed mechanism to account for the tissue-specific antithetical responses of hCRH gene expression to glucocorticolds, that may also explain the frequently observed antithetical effects of chronic gl...

The relationships among acculturation, biobehavioral risk, stress, corticotropin-releasing hormone, and poor birth outcomes in Hispanic women.

Science.gov (United States)

Ruiz, R Jeanne; Dolbier, Christyn L; Fleschler, Robin

2006-01-01

To determine the predictive ability of acculturation as an antecedent of stress, biobehavioral risk, corticotropin-releasing hormone levels, and poor birth outcomes in pregnant Hispanic women. A prospective, observational design with data collected at 22-25 weeks of gestation and at birth through medical record review. Public prenatal health clinics in south Texas serving low-income women. Self-identified Hispanic women who had singleton pregnancies, no major medical risk complications, and consented to answer questionnaires as well as a venipuncture and review of their prenatal and birth medical records. Gestational age, Apgar scores, length, weight, percentile size, and head circumference of the infant at birth. Significant differences were seen in infant birth weight, head circumference, and percentile size by acculturation. English acculturation predicted stress, corticotropin-releasing hormone, biobehavioral risk, and decreased gestational age at birth. Investigation must continue to understand the circumstances that give rise to the decline in birth outcomes observed in Hispanics with acculturation to the dominant English culture in the United States.

Nonreproductive role of gonadotropin-releasing hormone in the control of ascidian metamorphosis.

Science.gov (United States)

Kamiya, Chisato; Ohta, Naoyuki; Ogura, Yosuke; Yoshida, Keita; Horie, Takeo; Kusakabe, Takehiro G; Satake, Honoo; Sasakura, Yasunori

2014-12-01

Gonadotropin-releasing hormones (GnRHs) are neuropeptides that play central roles in the reproduction of vertebrates. In the ascidian Ciona intestinalis, GnRHs and their receptors are expressed in the nervous systems at the larval stage, when animals are not yet capable of reproduction, suggesting that the hormones have non-reproductive roles. We showed that GnRHs in Ciona are involved in the animal's metamorphosis by regulating tail absorption and adult organ growth. Absorption of the larval tail and growth of the adult organs are two major events in the metamorphosis of ascidians. When larvae were treated with GnRHs, they completed tail absorption more frequently than control larvae. cAMP was suggested to be a second messenger for the induction of tail absorption by GnRHs. tGnRH-3 and tGnRH-5 (the "t" indicates "tunicate") inhibited the growth of adult organs by arresting cell cycle progression in parallel with the promotion of tail absorption. This study provides new insights into the molecular mechanisms of ascidian metamorphosis conducted by non-reproductive GnRHs. © 2014 Wiley Periodicals, Inc.

Endocrinology and the brain: corticotropin-releasing hormone signaling.

Science.gov (United States)

Inda, Carolina; Armando, Natalia G; Dos Santos Claro, Paula A; Silberstein, Susana

2017-08-01

Corticotropin-releasing hormone (CRH) is a key player of basal and stress-activated responses in the hypothalamic-pituitary-adrenal axis (HPA) and in extrahypothalamic circuits, where it functions as a neuromodulator to orchestrate humoral and behavioral adaptive responses to stress. This review describes molecular components and cellular mechanisms involved in CRH signaling downstream of its G protein-coupled receptors (GPCRs) CRHR1 and CRHR2 and summarizes recent findings that challenge the classical view of GPCR signaling and impact on our understanding of CRHRs function. Special emphasis is placed on recent studies of CRH signaling that revealed new mechanistic aspects of cAMP generation and ERK1/2 activation in physiologically relevant contexts of the neurohormone action. In addition, we present an overview of the pathophysiological role of the CRH system, which highlights the need for a precise definition of CRHRs signaling at molecular level to identify novel targets for pharmacological intervention in neuroendocrine tissues and specific brain areas involved in CRH-related disorders. © 2017 The authors.

Analgesic effects of dexamethasone in burn injury

DEFF Research Database (Denmark)

Werner, Mads U; Lassen, Birgit Vibeke; Kehlet, Henrik

2002-01-01

and secondary hyperalgesia. RESULTS: The burn injury induced significant increases in erythema (P burn did not differ between dexamethasone and placebo treatments (P >.6). There were no significant......BACKGROUND AND OBJECTIVES: Glucocorticoids are well-known adjuvant analgesics in certain chronic pain states. There is, however, a paucity of data on their analgesic efficacy in acute pain. Therefore, the aim of the study was to examine the analgesic effects of dexamethasone in a validated burn...... model of acute inflammatory pain in humans. METHODS: Twenty-two volunteers were investigated in a double-blind, randomized, placebo-controlled cross-over study. Intravenous dexamethasone 8 mg or placebo was administered on 2 separate study days. Two hours after drug administration, a first-degree burn...

Serum Testosterone Levels in Prostate Cancer Patients Undergoing Luteinizing Hormone-Releasing Hormone Agonist Therapy.

Science.gov (United States)

Morote, Juan; Comas, Inma; Planas, Jacques; Maldonado, Xavier; Celma, Ana; Placer, José; Ferrer, Roser; Carles, Joan; Regis, Lucas

2018-04-01

Serum testosterone measurement is recommended to assess the efficacy of androgen deprivation therapy (ADT) and to diagnose castration resistance in patients with prostate cancer (PCa). Currently, the accepted castrate level of serum testosterone is 50 ng/dL. Liquid chromatography and tandem mass spectrometry (LC MSMS) is the appropriate method to measure testosterone, especially at low levels. However, worldwide, chemiluminescent assays (CLIAs) are used in clinical laboratories, despite their lack of accuracy and reproducibility, because they are automatable, fast, sensitive, and inexpensive. We compared serum testosterone levels measured using LC MSMS and CLIAs in 126 patients with PCa undergoing luteinizing hormone-releasing hormone (LHRH) agonist therapy. The median serum testosterone level was 14.0 ng/dL (range, 2.0-67.0 ng/dL) with LC MSMS and 31.9 ng/dL (range, 10.0-91.6 ng/dL) with CLIA (P  50 ng/dL in 3 patients (2.4%). These ranges were found in 34 (27%), 72 (57.1%), and 20 (15.9%) patients when testosterone was measured using CLIA (P < .001). The castrate level of serum testosterone using LC MSMS and CLIA was 39.8 ng/dL (95% confidence interval [CI], 37.1-43.4 ng/dL) and 66.5 ng/dL (95% CI, 62.3-71.2 ng/dL), respectively. We found that CLIA overestimated the testosterone levels in PCa patients undergoing LHRH agonist therapy. Thus, the castration level was incorrectly considered inadequate with CLIA in almost 15% of patients. The true castration level of serum testosterone using an appropriate method is < 50 ng/dL. Copyright © 2017 Elsevier Inc. All rights reserved.

A nonpeptidyl growth hormone secretagogue.

Science.gov (United States)

Smith, R G; Cheng, K; Schoen, W R; Pong, S S; Hickey, G; Jacks, T; Butler, B; Chan, W W; Chaung, L Y; Judith, F

1993-06-11

A nonpeptidyl secretagogue for growth hormone of the structure 3-amino-3-methyl-N-(2,3,4,5-tetrahydro-2-oxo-1-([2'-(1H-tetrazol-5 -yl) (1,1'-biphenyl)-4-yl]methyl)-1H-1-benzazepin-3(R)-yl)-butanamid e (L-692,429) has been identified. L-692,429 synergizes with the natural growth hormone secretagogue growth hormone-releasing hormone and acts through an alternative signal transduction pathway. The mechanism of action of L-692,429 and studies with peptidyl and nonpeptidyl antagonists suggest that this molecule is a mimic of the growth hormone-releasing hexapeptide His-D-Trp-Ala-Trp-D-Phe-Lys-NH2 (GHRP-6). L-692,429 is an example of a nonpeptidyl specific secretagogue for growth hormone.

Gonadotropin-Releasing Hormone Regulates Expression of the DNA Damage Repair Gene, Fanconi anemia A, in Pituitary Gonadotroph Cells1

OpenAIRE

Larder, Rachel; Chang, Lynda; Clinton, Michael; Brown, Pamela

2004-01-01

Gonadal function is critically dependant on regulated secretion of the gonadotropin hormones from anterior pituitary gonadotroph cells. Gonadotropin biosynthesis and release is triggered by the binding of hypothalamic GnRH to GnRH receptor expressed on the gonadotroph cell surface. The repertoire of regulatory molecules involved in this process are still being defined. We used the mouse LβT2 gonadotroph cell line, which expresses both gonadotropin hormones, as a model to investigate GnRH regu...

Gonadotropin releasing hormone agonists: Expanding vistas

Directory of Open Access Journals (Sweden)

Navneet Magon

2011-01-01

Full Text Available Gonadotropin-releasing hormone (GnRH agonists are derived from native GnRH by amino acid substitution which yields the agonist resistant to degradation and increases its half-life. The hypogonadotropic hypogonadal state produced by GnRH agonists has been often dubbed as "pseudomenopause" or "medical oophorectomy," which are both misnomers. GnRH analogues (GnRH-a work by temporarily "switching off" the ovaries. Ovaries can be "switched off" for the therapy and therapeutic trial of many conditions which include but are not limited to subfertility, endometriosis, adenomyosis, uterine leiomyomas, precocious puberty, premenstrual dysphoric disorder, chronic pelvic pain, or the prevention of menstrual bleeding in special clinical situations. Rapidly expanding vistas of usage of GnRH agonists encompass use in sex reassignment of male to female transsexuals, management of final height in cases of congenital adrenal hyperplasia, and preserving ovarian function in women undergoing cytotoxic chemotherapy. Hypogonadic side effects caused by the use of GnRH agonists can be tackled with use of "add-back" therapy. Goserelin, leuprolide, and nafarelin are commonly used in clinical practice. GnRH-a have provided us a powerful therapeutic approach to the treatment of numerous conditions in reproductive medicine. Recent synthesis of GnRH antagonists with a better tolerability profile may open new avenues for both research and clinical applications. All stakeholders who are partners in women′s healthcare need to join hands to spread awareness so that these drugs can be used to realize their full potential.

Gonadotropin-releasing hormone agonist trigger in oocyte donors co-treated with a gonadotropin-releasing hormone antagonist

DEFF Research Database (Denmark)

Vuong, T. N. L.; Ho, M. T.; Ha, T. D.

2016-01-01

-35 years, body mass index [BMI] hormone level >1.25 ng/mL, and antral follicle count >= 6). Intervention(s): Ovulation trigger with 0.2, 0.3, or 0.4 mg triptorelin in a GnRH antagonist cycle. Main Outcome Measure(s): The primary end point was number of metaphase II oocytes...... to number of metaphase II oocytes (16.0 +/- 8.5, 15.9 +/- 7.8, and 14.7 +/- 8.4, respectively), embryos (13.2 +/- 7.8, 11.7 +/- 6.9, 11.8 +/- 7.0), and number of top-quality embryos (3.8 +/- 2.9, 3.6 +/- 3.0, 4.1 +/- 3.0). Luteinizing hormone levels at 24 hours and 36 hours after trigger was significantly...

Chromosomal localization of the gonadotropin-releasing hormone receptor gene to human chromosome 4q13. 1-q21. 1 and mouse chromosome 5

Energy Technology Data Exchange (ETDEWEB)

Kaiser, U.B.; Dushkin, H.; Beier, D.R.; Chin, W.W. (Harvard Medical School, Boston, MA (United States)); Altherr, M.R. (Los Alamos National Lab., NM (United States))

1994-04-01

The gonadotropin-releasing hormone receptor (GRHR) is a G-protein-coupled receptor on the cell surface of pituitary gonadotropes, where it serves to transduce signals from the extracellular ligand, the hypothalamic factor gonadotropin-releasing hormone, and to modulate the synthesis and secretion of luteinizing hormone and follicle-stimulating hormone. The authors have localized the GRHR gene to the q13.1-q21.1 region of the human chromosome 4 using mapping panels of human/rodent somatic cell hybrids containing different human chromosomes or different regions of human chromosome 4. Furthermore, using linkage analysis of single-strand conformational polymorphisms, the murine GRHR gene was localized to mouse chromosome 5, linked to the endogenous retroviral marker Pmv-11. This is consistent with the evolutionary conservation of homology between these two regions, as has been previously suggested from comparative mapping of several other loci. The localization of the GRHR gene may be useful in the study of disorders of reproduction. 22 refs., 2 figs.

Function of gonadotropin-releasing hormone in olfaction.

Science.gov (United States)

Wirsig-Wiechmann, C R

2001-06-01

Gonadotropin-releasing hormone (GnRH) is present within neurons of the nervus terminalis, the zeroeth cranial nerve. In all vertebrate species, except in sharks where it is a separate nerve, the nervus terminalis consists of a chain of neurons embedded within olfactory or vomeronasal nerves in the nasal cavity. The function of the GnRH component of the nervus terminalis is thought to be neuromodulatory. Our research on GnRH effects on olfaction confirms this hypothesis. The processes of GnRH neural cell bodies located within chemosensory nerves project centrally into the ventral forebrain and peripherally into the lamina propria of the nasal chemosensory mucosa. GnRH receptors are expressed by chemosensory neurons as shown by RT-PCR/Southern blotting and GnRH agonist binding studies. Patch-clamp studies have shown that GnRH alters the responses of isolated chemosensory neurons to natural or electrophysiological stimulation through the modulation of voltage-gated and receptor-gated channels. Behavioral experiments demonstrate that interfering with the nasal GnRH system leads to deficits in mating behavior. These studies suggest that the function of the intranasal GnRH system is to modify olfactory information, perhaps at reproductively auspicious times. We speculate that the purpose of this altered olfactory sense is to make pheromones more detectable and salient.

Dexamethasone enhances the anti-emetic effect of metoclopramide ...

African Journals Online (AJOL)

Ninety patients, ASA I or II, aged 21-64years were randomly selected to either the dexamethasone-metoclopramide group, metoclopramide group or dexamethasone group using computer-generated random numbers . Spinal anaesthesia was induced in the sitting position under strict aseptic technique with hyperbaric ...

Double insemination and gonadotropin-releasing hormone treatment of repeat-breeding dairy cattle.

Science.gov (United States)

Stevenson, J S; Call, E P; Scoby, R K; Phatak, A P

1990-07-01

Our objective was to determine if double inseminations during the same estrous period of dairy cattle eligible for their third or fourth service (repeat breeders) would improve pregnancy rates equivalent to injections of GnRH given at the time of AI. Repeat-breeding, lactating cows from six herds (five herds in the San Joaquin Valley of central California and one herd in northeast Kansas) were assigned randomly to four treatment groups when detected in estrus: 1) single AI plus no injection, 2) single AI plus 100 micrograms GnRH at AI, 3) double AI plus no injection, or 4) double AI plus 100 micrograms of GnRH at AI. Inseminations were performed according to the a.m.-p.m. rule. The second AI for the double AI treatment was given 12 to 16 h after the first AI. Injections of GnRH were given intramuscularly immediately following the single AI or the first AI of the double AI. Pregnancy rates of cows given a single AI and hormone injection were numerically higher in all six herds than those of their herdmates given only a single AI. In five of six herds, the pregnancy rates of cows given a double AI and hormone injection were numerically higher than pregnancy rates of their herdmates given only a double AI. Overall pregnancy rates for the four treatments were 1) 112/353 (32.1%), 2) 165/406 (41.6%), 3) 119/364 (33.5%), and 4) 135/359 (37.5%). Gonadotropin-releasing hormone increased pregnancy rates of repeat breeders compared with controls given only a single AI. No further benefit beyond the single AI was accrued from the double AI treatment, with or without concurrent hormone administration.

Dexamethasone for pain after outpatient shoulder surgery

DEFF Research Database (Denmark)

Bjørnholdt, K. T.; Mønsted, P. N.; Søballe, Kjeld

2014-01-01

Background Dexamethasone has analgesic properties when given intravenously before surgery, but the optimal dose has not been determined. We hypothesised that a dose of 40 mg dexamethasone would improve analgesia after outpatient shoulder surgery compared with 8 mg. Methods A randomised, double...... a dose–response relationship, increasing the dexamethasone dose from 8 to 40 mg did not improve analgesia significantly after outpatient shoulder surgery.......) or placebo (D0) before surgery. The primary outcome was pain intensity 8 h after surgery rated on a numeric rating scale of 0 to 10. Secondary outcomes were pain intensity, analgesic consumption and side effects during the first 3 days after surgery. Results Data from 73 patients were available for analysis...

Structural and functional divergence of growth hormone-releasing hormone receptors in early sarcopterygians: lungfish and Xenopus.

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Janice K V Tam

Full Text Available The evolutionary trajectories of growth hormone-releasing hormone (GHRH receptor remain enigmatic since the discovery of physiologically functional GHRH-GHRH receptor (GHRHR in non-mammalian vertebrates in 2007. Interestingly, subsequent studies have described the identification of a GHRHR(2 in chicken in addition to the GHRHR and the closely related paralogous receptor, PACAP-related peptide (PRP receptor (PRPR. In this article, we provide information, for the first time, on the GHRHR in sarcopterygian fish and amphibians by the cloning and characterization of GHRHRs from lungfish (P. dolloi and X. laevis. Sequence alignment and phylogenetic analyses demonstrated structural resemblance of lungfish GHRHR to their mammalian orthologs, while the X. laevis GHRHR showed the highest homology to GHRHR(2 in zebrafish and chicken. Functionally, lungfish GHRHR displayed high affinity towards GHRH in triggering intracellular cAMP and calcium accumulation, while X. laevis GHRHR(2 was able to react with both endogenous GHRH and PRP. Tissue distribution analyses showed that both lungfish GHRHR and X. laevis GHRHR(2 had the highest expression in brain, and interestingly, X. laevis(GHRHR2 also had high abundance in the reproductive organs. These findings, together with previous reports, suggest that early in the Sarcopterygii lineage, GHRHR and PRPR have already established diverged and specific affinities towards their cognate ligands. GHRHR(2, which has only been found in xenopus, zebrafish and chicken hitherto, accommodates both GHRH and PRP.

Changes in gonadotropin-releasing hormone and gonadotropin-releasing hormone receptor gene expression after an increase in carbon monoxide concentration in the cavernous sinus of male wild boar and pig crossbread.

Science.gov (United States)

Romerowicz-Misielak, M; Tabecka-Lonczynska, A; Koziol, K; Gilun, P; Stefanczyk-Krzymowska, S; Och, W; Koziorowski, M

2016-06-01

Previous studies indicate that there are at least a few regulatory systems involved in photoperiodic synchronisation of reproductive activity, which starts with the retina and ends at the gonadotropin-releasing hormone (GnRH) pulse generator. Recently we have shown indicated that the amount of carbon monoxide (CO) released from the eye into the ophthalmic venous blood depends on the intensity of sunlight. The aim of this study was to test whether changes in the concentration of carbon monoxide in the ophthalmic venous blood may modulate reproductive activity, as measured by changes in GnRH and GnRH receptor gene expression. The animal model used was mature male swine crossbred from wild boars and domestic sows (n = 48). We conducted in vivo experiments to determine the effect of increased CO concentrations in the cavernous sinus of the mammalian perihypophyseal vascular complex on gene expression of GnRH and GnRH receptors as well as serum luteinizing hormone (LH) levels. The experiments were performed during long photoperiod days near the summer solstice (second half of June) and short photoperiod days near the winter solstice (second half of December). These crossbred swine demonstrated a seasonally-dependent marked variation in GnRH and GnRH receptor gene expression and systemic LH levels in response to changes in CO concentration in ophthalmic venous blood. These results seem to confirm the hypothesis of humoral phototransduction as a mechanism for some of bright light's effects in animal chronobiology and the effect of CO on GnRH and GnRH receptor gene expression.

Randomized clinical trial of dexamethasone versus placebo in laparoscopic inguinal hernia repair

DEFF Research Database (Denmark)

Tolver, M A; Strandfelt, P; Bryld, Clara E

2012-01-01

The effect of dexamethasone on recovery and length of convalescence has not been evaluated in patients after laparoscopic groin hernia repair. It was hypothesized that preoperative intravenous dexamethasone would reduce postoperative pain.......The effect of dexamethasone on recovery and length of convalescence has not been evaluated in patients after laparoscopic groin hernia repair. It was hypothesized that preoperative intravenous dexamethasone would reduce postoperative pain....

Flatfish metamorphosis: a hypothalamic independent process?

Science.gov (United States)

Campinho, Marco A; Silva, Nadia; Roman-Padilla, Javier; Ponce, Marian; Manchado, Manuel; Power, Deborah M

2015-03-15

Anuran and flatfish metamorphosis are tightly regulated by thyroid hormones that are the necessary and sufficient factors that drive this developmental event. In the present study whole mount in situ hybridization (WISH) and quantitative PCR in sole are used to explore the central regulation of flatfish metamorphosis. Central regulation of the thyroid in vertebrates is mediated by the hypothalamus-pituitary-thyroid (HPT) axis. Teleosts diverge from other vertebrates as hypothalamic regulation in the HPT axis is proposed to be through hypothalamic inhibition although the regulatory factor remains enigmatic. The dynamics of the HPT axis during sole metamorphosis revealed integration between the activity of the thyrotrophes in the pituitary and the thyroid follicles. No evidence was found supporting a role for thyroid releasing hormone (trh) or corticotrophin releasing hormone (crh) in hypothalamic control of TH production during sole metamorphosis. Intriguingly the results of the present study suggest that neither hypothalamic trh nor crh expression changes during sole metamorphosis and raises questions about the role of these factors and the hypothalamus in regulation of thyrotrophs. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Is radiation-induced ovarian failure in rhesus monkeys preventable by luteinizing hormone-releasing hormone agonists?: Preliminary observations

International Nuclear Information System (INIS)

Ataya, K.; Pydyn, E.; Ramahi-Ataya

1995-01-01

With the advent of cancer therapy, increasing numbers of cancer patients are achieving long term survival. Impaired ovarian function after radiation therapy has been reported in several studies. Some investigators have suggested that luteinizing hormone-releasing hormone agonists (LHRHa) can prevent radiation-induced ovarian injury in rodents. Adult female rhesus monkeys were given either vehicle or Leuprolide acetate before, during, and after radiation. Radiation was given in a dose of 200 rads/day for a total of 4000 rads to the ovaries. Frequent serum samples were assayed for estradiol (E 2 ) and FSH. Ovariectomy was performed later. Ovaries were processed and serially sectioned. Follicle count and size distribution were determined. Shortly after radiation started, E 2 dropped to low levels, at which it remained, whereas serum FSH level, which was low before radiation, rose soon after starting radiation. In monkeys treated with a combination of LHRHa and radiation, FSH started rising soon after the LHRHa-loaded minipump was removed (after the end of radiation). Serum E 2 increased after the end of LHRHa treatment in the non-irradiated monkey, but not in the irradiated monkey. Follicle counts were not preserved in the LHRHa-treated monkeys that received radiation. The data demonstrated no protective effect of LHRHa treatment against radiation-induced ovarian injury in this rhesus monkey model. 58 refs., 2 figs., 1 tab

Dexamethasone Does Not Inhibit Sugammadex Reversal After Rocuronium-Induced Neuromuscular Block.

Science.gov (United States)

Buonanno, Pasquale; Laiola, Anna; Palumbo, Chiara; Spinelli, Gianmario; Servillo, Giuseppe; Di Minno, Raffaele Maria; Cafiero, Tullio; Di Iorio, Carlo

2016-06-01

Sugammadex is a relatively new molecule that reverses neuromuscular block induced by rocuronium. The particular structure of sugammadex traps the cyclopentanoperhydrophenanthrene ring of rocuronium in its hydrophobic cavity. Dexamethasone shares the same steroidal structure with rocuronium. Studies in vitro have demonstrated that dexamethasone interacts with sugammadex, reducing its efficacy. In this study, we investigated the clinical relevance of this interaction and its influence on neuromuscular reversal. In this retrospective case-control study, we analyzed data from 45 patients divided into 3 groups: dexamethasone after induction group (15 patients) treated with 8 mg dexamethasone as an antiemetic drug shortly after induction of anesthesia; dexamethasone before reversal group (15 patients) treated with dexamethasone just before sugammadex injection; and control group (15 patients) treated with 8 mg ondansetron. All groups received 0.6 mg/kg rocuronium at induction, 0.15 mg/kg rocuronium at train-of-four ratio (TOF) 2 for neuromuscular relaxation, and 2 mg/kg sugammadex for reversal at the end of the procedure at TOF2. Neuromuscular relaxation was monitored with a TOF-Watch® system. The control group had a recovery time of 154 ± 54 seconds (mean ± SD), the dexamethasone after induction group 134 ± 55 seconds, and the dexamethasone before reversal group 131 ± 68 seconds. The differences among groups were not statistically significant (P = 0.5141). Our results show that the use of dexamethasone as an antiemetic drug for the prevention of postoperative nausea and vomiting does not interfere with reversal of neuromuscular blockade with sugammadex in patients undergoing elective surgery with general anesthesia in contrast to in vitro studies that support this hypothesis.

Pharmacokinetics and tolerance study of intravitreal injection of dexamethasone-loaded nanoparticles in rabbits

Directory of Open Access Journals (Sweden)

Linhua Zhang

2009-09-01

Full Text Available Linhua Zhang1, Yue Li2, Chao Zhang1, Yusheng Wang2, Cunxian Song11Institute of Biomedical Engineering, Peking Union Medical College and Chinese Academy of Medical Sciences, Tianjin, China; 2Department of Ophthalmology, Institute of Ophthalmology of Chinese PLA, Xijing Hospital, Fourth Military Medical University, Xi’an, ChinaAbstract: The aim of the study was to investigate the tolerance and pharmacokinetics of dexamethasone (DEX-loaded poly(lactic acid–co-glycolic acid nanoparticles (DEX-NPs in rabbits after intravitreal injection. The DEX-NPs were prepared and characterized in terms of morphology, particle size and size distribution, encapsulation efficiency, and in vitro release. Ophthalmic investigations were performed, including fundus observation and photography, intraocular pressure measurement, and B-scan ocular ultrasonography. There were no abnormalities up to 50 days after administration of DEX-NPs in rabbits. The DEX concentrations in plasma and the ocular tissues such as the cornea, aqueous humor, lens, iris, vitreous humor, and chorioretina were determined by high-pressure liquid chromatography. The DEX-NPs maintained a sustained release of DEX for about 50 days in vitreous and provided relatively constant DEX levels for more than 30 days with a mean concentration of 3.85 mg/L-1. Based on the areas under the curve, the bioavailability of DEX in the experimental group was significantly higher than that in the control group injected with regular DEX. These results suggest that intravitreal injection of DEX-NPs lead to a sustained release of DEX with a high bioavailability, providing a basis for a novel approach to the treatment of posterior segment diseases.Keywords: dexamethasone, nanoparticles, intravitreal injection, pharmacokinetics

Second-line tests in the differential diagnosis of ACTH-dependent Cushing's syndrome.

Science.gov (United States)

Barbot, Mattia; Trementino, Laura; Zilio, Marialuisa; Ceccato, Filippo; Albiger, Nora; Daniele, Andrea; Frigo, Anna Chiara; Mardari, Rodica; Rolma, Giuseppe; Boscaro, Marco; Arnaldi, Giorgio; Scaroni, Carla

2016-10-01

Diagnosing Cushing's syndrome (CS) can be a challenge, especially in ACTH-dependent CS, when it comes to detecting the origin of ACTH secretion. Retrospective data were collected on 170 patients with ACTH-dependent CS (149 CD, 21 EAS) referring to two endocrinology units, focusing on three non-invasive tests: dexamethasone 8 mg overnight challenge (HDDST); corticotrophin-releasing hormone (CRH) assay and the desmopressin (DDAVP) test. Patients with EAS were slightly older and had higher ACTH, serum and urinary cortisol levels than patients with CD (p 52.7 % below the basal level suggested a pituitary origin with a SE of 88 % (95 % CI 81-93) and a SP of 90 % (95 % CI 68-99). There were no cases of EAS with positive responses to both these tests. Increases in ACTH and cortisol levels after the DDAVP test were also higher in CD than in EAS (p < 0.01), though the SE and SP were lower. Patients with CD showed a stronger response to HDDST and CRH, and the adopted cut-offs showed a good SE and SP in discriminating them from patients with EAS. Concordant tests indicated CD when positive, whereas no response to either test was highly suggestive of EAS. The DDAVP test was of limited utility in the diagnostic phase. In conclusion, the choice of tests may play an important part in the differential diagnosis of ACTH-dependent CS.

Prepubertal Development of Gonadotropin-Releasing Hormone Neuron Activity Is Altered by Sex, Age, and Prenatal Androgen Exposure.

Science.gov (United States)

Dulka, Eden A; Moenter, Suzanne M

2017-11-01

Gonadotropin-releasing hormone (GnRH) neurons regulate reproduction though pulsatile hormone release. Disruption of GnRH release as measured via luteinizing hormone (LH) pulses occurs in polycystic ovary syndrome (PCOS), and in young hyperandrogenemic girls. In adult prenatally androgenized (PNA) mice, which exhibit many aspects of PCOS, increased LH is associated with increased GnRH neuron action potential firing. How GnRH neuron activity develops over the prepubertal period and whether this is altered by sex or prenatal androgen treatment are unknown. We hypothesized GnRH neurons are active before puberty and that this activity is sexually differentiated and altered by PNA. Dams were injected with dihydrotestosterone (DHT) on days 16 to 18 post copulation to generate PNA mice. Action potential firing of GFP-identified GnRH neurons in brain slices from 1-, 2-, 3-, and 4-week-old and adult mice was monitored. GnRH neurons were active at all ages tested. In control females, activity increased with age through 3 weeks, then decreased to adult levels. In contrast, activity did not change in PNA females and was reduced at 3 weeks. Activity was higher in control females than males from 2 to 3 weeks. PNA did not affect GnRH neuron firing rate in males at any age. Short-term action potential patterns were also affected by age and PNA treatment. GnRH neurons are thus typically more active during the prepubertal period than adulthood, and PNA reduces prepubertal activity in females. Prepubertal activity may play a role in establishing sexually differentiated neuronal networks upstream of GnRH neurons; androgen-induced changes during this time may contribute to the adult PNA, and possibly PCOS, phenotype. Copyright © 2017 Endocrine Society.

Paradoxical response to dexamethasone and spontaneous hypocortisolism in Cushing's disease

OpenAIRE

Lila, Anurag R; Sarathi, Vijaya; Bandgar, Tushar R; Shah, Nalini S

2013-01-01

Paradoxical response to dexamethasone and spontaneous development of hypocortisolism are rare features of Cushing's disease. We report a 13-year-old boy with Cushing's disease owing to a pituitary macroadenoma. On initial evaluation, he had partial suppression of serum cortisol by dexamethasone. He developed transient hypocortisolism after first adenomectomy, but the disease recurred after 1 year. Repeat evaluation showed recurrent hypercortisolism and paradoxical response to dexamethasone. H...

Thyrotropin-releasing hormone (TRH) reverses hyperglycemia in rat

International Nuclear Information System (INIS)

Luo Luguang; Luo, John Z.Q.; Jackson, Ivor M.D.

2008-01-01

Hyperglycemia in thyrotropin-releasing hormone (TRH) null mice indicates that TRH is involved in the regulation of glucose homeostasis. Further, TRH levels in the pancreas peak during the stages of late embryonic and early neonatal β cell development. These observations are consistent in linking TRH to islet cell proliferation and differentiation. In this study, we examined the effect of TRH administration in damaged pancreatic rat (streptozotocin, STZ) to determine whether TRH could improve damaged pancreatic β cells function. We hypothesize that TRH is able to reverse STZ-induced hyperglycemia by increasing pancreatic islet insulin content, preventing apoptosis, and potentially induce islet regeneration. It was found that following intra-peritoneal (ip) injection, TRH (10 μg/kg body weight (bwt)) reverses STZ (65 mg/kg bwt)-induced hyperglycemia (TRH given 3 days after STZ injection). Increased circulating insulin levels and insulin content in extracted pancreas suggests that TRH reversed STZ-induced hyperglycemia through improving pancreatic islet β cell function. Further studies show a significantly lower level of apoptosis in islets treated with TRH as well as the presence of proliferation marker nestin and Brdu, suggesting that the TRH has the potential to prevent apoptosis and stimulate islet proliferation

The use of dexamethasone in animals: implication for fertility ...

African Journals Online (AJOL)

Exposure to dexamethasone causes numerous changes in various biological systems including the reproductive system and this has huge implication on fertility and pregnancy. Maternal dexamethasone administration promotes foetal lung maturation and thermoregulation in premature foetuses. This indication makes ...

Negative feedback governs gonadotrope frequency-decoding of gonadotropin releasing hormone pulse-frequency.

Directory of Open Access Journals (Sweden)

Stefan Lim

Full Text Available The synthesis of the gonadotropin subunits is directed by pulsatile gonadotropin-releasing hormone (GnRH from the hypothalamus, with the frequency of GnRH pulses governing the differential expression of the common alpha-subunit, luteinizing hormone beta-subunit (LHbeta and follicle-stimulating hormone beta-subunit (FSHbeta. Three mitogen-activated protein kinases, (MAPKs, ERK1/2, JNK and p38, contribute uniquely and combinatorially to the expression of each of these subunit genes. In this study, using both experimental and computational methods, we found that dual specificity phosphatase regulation of the activity of the three MAPKs through negative feedback is required, and forms the basis for decoding the frequency of pulsatile GnRH. A fourth MAPK, ERK5, was shown also to be activated by GnRH. ERK5 was found to stimulate FSHbeta promoter activity and to increase FSHbeta mRNA levels, as well as enhancing its preference for low GnRH pulse frequencies. The latter is achieved through boosting the ultrasensitive behavior of FSHbeta gene expression by increasing the number of MAPK dependencies, and through modulating the feedforward effects of JNK activation on the GnRH receptor (GnRH-R. Our findings contribute to understanding the role of changing GnRH pulse-frequency in controlling transcription of the pituitary gonadotropins, which comprises a crucial aspect in regulating reproduction. Pulsatile stimuli and oscillating signals are integral to many biological processes, and elucidation of the mechanisms through which the pulsatility is decoded explains how the same stimulant can lead to various outcomes in a single cell.

Influence of dexamethasone and weight loss on the regulation of serum leptin levels in obese individuals

Directory of Open Access Journals (Sweden)

D.D.G. Lerario

2001-04-01

Full Text Available The adipocyte hormone leptin is thought to serve as a signal to the central nervous system reflecting the status of fat stores. Serum leptin levels and adipocyte leptin messenger RNA levels are clearly increased in obesity. Nevertheless, the factors regulating leptin production are not fully understood. The aim of this study was to determine the effects of in vivo administration of the synthetic glucocorticoid dexamethasone and weight loss on serum leptin levels in two independent protocols. Twenty-five obese subjects were studied (18 women and 7 men, mean age 26.6 ± 6 years, BMI 31.1 ± 2.5 kg/m², %fat 40.3 ± 8.3 and compared at baseline to 22 healthy individuals. Serum levels of leptin, insulin, proinsulin and glucose were assessed at baseline and after ingestion of dexamethasone, 4 mg per day (2 mg, twice daily for two consecutive days. To study the effects of weight loss on serum leptin, 17 of the obese subjects were submitted to a low-calorie dietary intervention trial for 8 weeks and again blood samples were collected. Serum leptin levels were significantly higher in the obese group compared to the control group and a high positive correlation between leptinemia and the magnitude of fat mass was found (r = 0.88, P<0.0001. After dexamethasone, there was a significant increase in serum leptin levels (22.9 ± 12.3 vs 51.4 ± 23.3 ng/ml, P<0.05. Weight loss (86.1 ± 15.1 vs 80.6 ± 14.2 kg, P<0.05 led to a reduction in leptin levels (25.13 ± 12.8 vs 15.9 ± 9.1 ng/ml, P<0.05. We conclude that serum leptin levels are primordially dependent on fat mass magnitude. Glucocorticoids at supraphysiologic levels are potent secretagogues of leptin in obese subjects and a mild fat mass reduction leads to a disproportionate decrease in serum leptin levels. This suggests that, in addition to the changes in fat mass, complex nutritional and hormonal interactions may also play an important role in the regulation of leptin levels.

CHARACTERIZATION OF THE RECEPTOR FOR GONADOTROPIN-RELEASING HORMONE IN THE PITUITARY OF THE AFRICAN CATFISH, CLARIAS-GARIEPINUS

NARCIS (Netherlands)

de Leeuw, R.; Conn, P. M.; van't Veer, C.; Goos, H. J.; van Oordt, P. G.

1988-01-01

Receptors for gonadotropin-releasing hormone (GnRH) were characterized using a radioligand prepared from a superactive analog of salmon GnRH (sGnRH), D-Arg(6)-Pro(9)-sGnRH-NEt (sGnRHa). Binding of(125)I-sGnRHa to catfish pituitary membrane fractions reached equilibrium after 2 h incubation at 4°C.

Physicochemical and mechanical properties of freeze cast hydroxyapatite-gelatin scaffolds with dexamethasone loaded PLGA microspheres for hard tissue engineering applications

Energy Technology Data Exchange (ETDEWEB)

Ghorbani, Farnaz, E-mail: Farnaz_ghorbani.1991@yahoo.com [Department of Biomedical Engineering, Tehran Science and Research Branch, Islamic Azad University, P. O. Box: 4515/775, Tehran (Iran, Islamic Republic of); Nojehdehian, Hanieh, E-mail: hanieh.nojehdehyan@gmail.com [Department of Dental Materials, School of Dentistry, Shahid Beheshti University of Medical Sciences, P.O. Box: 1983963113, Tehran (Iran, Islamic Republic of); Zamanian, Ali, E-mail: a-zamanian@merc.ac.ir [Biomaterials Research Group, Department of Nanotechnology and Advanced Materials, Materials and Energy Research Center, P.O. Box: 14155-4777, Tehran (Iran, Islamic Republic of)

2016-12-01

Hydroxyapatite (HA)-gelatin scaffolds incorporated with dexamethasone-loaded polylactic-co-glycolic acid (PLGA) microspheres were synthesized by freeze casting technique. Scanning electron microscopy (SEM) micrographs demonstrated a unidirectional microstructure and a decrease in the pore size as a function of temperature gradient. Higher amounts of HA resulted in a decrease in the pore size. According to the results, at lower cooling rates, the formation of a lamellar structure decreased the mechanical strength, but at the same time, enhanced the swelling ratio, biodegradation rate and drug release level. On the other hand, higher weight ratios of HA increased the compressive strength, and reduced the swelling ratio, biodegradation rate and drug release level. The results obtained by furrier transform infrared spectroscopy (FTIR) and bioactivity analysis illustrated that the interactions of the materials support the apatite formation in the simulated body fluid (SBF) solution. Based on the obtained results, the synthesized composite scaffolds have the necessary mechanical and physicochemical features to support the regeneration of defects and to maintain their stability during the neo-tissue formation. - Highlights: • Freeze casting technique created unidirectional lamellar type microstructure. • Unidirectional microstructure of samples improved mechanical behavior, absorption, biodegradation rate and release behavior. • Hydroxyapatite-gelatin scaffolds demonstrated bioactive behavior and support new apatite layer formation. • Controlled release rate provided by dexamethasone loaded PLGA microspheres.

Anterior migration of dexamethasone implant in a pseudophakic patient with intact posterior capsule

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Nilufer Kocak

2014-01-01

Full Text Available Intravitreal application of Ozurdex ® (Allergan, Inc., Irvine, CA, USA which is a biodegradable, sustained-release dexamethasone implant has been reported to be effective in the treatment of macular edema. Migration of such implant into the anterior chamber has been recently described in cases without perfect zonular or the posterior capsular integrity. Herein, we report the first case with anterior migration of Ozurdex ® implant that mislocated just behind the intraocular lens (IOL in an intact capsular bag. It is thought that such implant migrated anteriorly towards into the posterior chamber through weak zonules as the present case had a medical history of uneventful phacoemulsification surgery with the implantation of posterior chamber IOL. However, the migrated implant was well tolerated since there was no sign of the corneal complication, rise in intraocular pressure, and anterior chamber reaction. Close follow-up was scheduled to find out any signs of anterior segment pathology. Meanwhile dexamethasone implant completely degraded at the 4 th month of postoperative follow-up.

Development of new radioactive labelling methods (3H and 11C) in luteizing hormone (LH) and its releasing hormone (LRF). Study of physico-chemical properties of LRF by circular dichroism and emission spectroscopy

International Nuclear Information System (INIS)

Marche, Pierre.

1975-01-01

After a brief review of present knowledge on the hypothalamus-hypophysis this thesis falls into three parts. The first situates the peptide hormones studied in their biological context. Research on the radioactive labelling of hormonal peptides is dealt with in part two which includes, besides the application of already known tritiation methods to particular problems, the description of a new tritium labelling method and the use of carbon 11 for the kinetic distribution study of a hormone. Part three concerns the physico-chemical study of a hypothalamic hormone. As a contribution towards research on the hypophysary gonadotrophic function regulation, the work involved in all the above three sections was directed towards the luteinising hormone (LH) and its hypothalamic release factor (LRF). During the study of this latter the problem of peptides containing tryptophane arose and was consequently investigated [fr

Effects of dexamethasone on liver enzymes and some serum ...

African Journals Online (AJOL)

Concomitant usage of dexamethasone and other medications may alter electrolyte metabolism and increase the formation of potentially hepatotoxic reactive metabolites which can contribute to elevated liver enzymes. The role of dexamethasone in liver functions and electrolyte metabolism during pregnancy in Yankasa ...

Tapered oral dexamethasone for the acute chest syndrome of sickle cell disease

Science.gov (United States)

Quinn, Charles T.; Stuart, Marie J.; Kesler, Karen; Ataga, Kenneth I.; Wang, Winfred C.; Styles, Lori; Smith-Whitley, Kim; Wun, Ted; Raj, Ahsok; Hsu, Lewis L.; Krishnan, Suba; Kuypers, Frans A; Setty, B. N. Yamaja; Rhee, Seungshin; Key, Nigel S.; Buchanan, George R.

2011-01-01

Summary Tapered oral dexamethasone for acute chest syndrome (ACS) in sickle cell anaemia was studied using a novel ACS assessment tool and investigational biomarkers. Twelve participants were randomized (mean age 17.3 years) before early study termination. Dexamethasone decreased duration of hospitalization for ACS by 20.8 h compared to placebo (P=0.024). Rebound pain occurred in both groups (3 dexamethasone vs. 1 placebo). Overall, dexamethasone decreased the leucocyte activation biomarker, sL-selectin; however, participants with rebound pain had higher sL-selectin within 24 h of treatment (dexamethasone or placebo). This ACS assessment tool was feasibly applied, and sL-selectin is a promising biomarker of ACS therapy. PMID:21848879

Dexamethasone minimizes the risk of cranial nerve injury during CEA.

Science.gov (United States)

Regina, Guido; Angiletta, Domenico; Impedovo, Giovanni; De Robertis, Giovanni; Fiorella, Marialuisa; Carratu', Maria Rosaria

2009-01-01

The incidence of cranial and cervical nerve injury during carotid endarterectomy (CEA) ranges from less than 7.6% to more than 50%. Lesions are mainly due to surgical maneuvers such as traction, compression, tissue electrocoagulation, clamping, and extensive dissections. The use of dexamethasone (DEX) and its beneficial effects in spinal cord injuries have already been described. We investigated whether DEX could also be beneficial to minimize the incidence of cranial and cervical nerve injury during CEA. To evaluate whether dexamethasone is able to reduce the incidence of cranial nerve injuries. From March 1999 through April 2006, 1126 patients undergoing CEA because of high-grade carotid stenosis were enrolled and randomized by predetermined randomization tables into two groups. The first group, "A", included 586 patients that all received an intravenous administration of dexamethasone following a therapeutic scheme. The second group, "B", included 540 control subjects that received the standard pre- and postoperative therapy. All patients were submitted to a deep cervical plexus block, eversion carotid endarterectomy, and selective shunting. Three days after the operation, an independent neurologist and otorhinolaryngologist evaluated the presence of cranial nerve deficits. All patients (group A and group B) showing nerve injuries continued the treatment (8 mg of dexamethasone once in the morning) for 7 days and were re-evaluated after 2 weeks, 30 days, and every 3 months for 1 year. Recovery time took from 2 weeks to 12 months, with a mean time of 3.6 months. The chi(2) test was used to compare the two groups and to check for statistical significance. The incidence of cranial nerve dysfunction was higher in group B and the statistical analysis showed a significant effect of dexamethasone in preventing the neurological damage (P = .0081). The incidence of temporary lesions was lower in group A and the chi(2) test yielded a P value of .006. No statistically

Effects of dexamethasone on brain edema. Uptake and distribution of tritiated (/sup 3/H) dexamethasone in cold induced edema

Energy Technology Data Exchange (ETDEWEB)

Takemoto, Motohisa [Okayama Univ. (Japan). School of Medicine

1982-06-01

Experimental cerebral edema was produced on the right parietal lobe of Wistar male rats with a cold metal probe cooled by liquid nitrogen. Twenty hour later, /sup 3/H-dexamethasone was either intramuscularly or intravenously injected into rats, estimated in the brain tissue by the liquid scintillation counting method. Edematous brain generally contained much higher /sup 3/H-activity than the control. Furthermore, I.V. injection showed higher /sup 3/H-activity than I.M injection in edematous and control brains at all times. For examination of the subcellular distribution of /sup 3/H-dexamethasone in edematous brain, /sup 3/H-activity was most strongly detected in the supernatant fraction (63%), followed by the heavy mitochondrial fraction (25.4%) and the nuclear fraction (8.4%). Although edematous brain tissue constantly demonstrated higher /sup 3/H-activity than the control, its supernatant fraction conversely had less activity. As a next step, distribution of /sup 3/H-dexamethasone in the supernatant fraction was studies. The result was that the high molecular weight fraction in the edematous brain showed higher radioactivity than the control. From these findings, unequivocal distribution of dexamethasone in the supernatant fraction of edematous brain tissue could be correlated with its biochemical action for preventing brain edema.

Colocalization of corticotropin-releasing hormone and oestrogen receptor-alpha in the paraventricular nucleus of the hypothalamus in mood disorders

NARCIS (Netherlands)

Bao, Ai-Min; Hestiantoro, Andon; van Someren, Eus J. W.; Swaab, Dick F.; Zhou, Jiang-Ning

2005-01-01

Oestrogens may modulate the activity of the hypothalamic-pituitary-adrenal (HPA) axis. The present study was to investigate whether the activity of the HPA axis in mood disorders might be directly modulated by oestrogens via oestrogen receptors (ORs) in the corticotropin-releasing hormone (CRH)

Structural Stereochemistry of Androstene Hormones Determines Interactions with Human Androgen, Estrogen, and Glucocorticoid Receptors

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Thomas L. Shaak

2013-01-01

Full Text Available DHEA, 17α-AED, 17β-AED, and 17β-AET exhibit strong biological activity that has been attributed to androgenic, estrogenic, or antiglucocorticoid activity in vivo and in vitro. This study compared DHEA, 17α-AED, 17β-AED, and 17β-AET for their ability to activate the human AR, ER, and GR and determine the relative androgenicity, estrogenicity, and glucocorticoid activity. The results show that, at the receptor level, these androstene hormones are weak AR and even weaker ER activators. Direct androstene hormone activation of the human AR, ERα, and ERβ may not be essential for their biological function. Similarly, these hormones indirectly activated the human GR, only in the presence of high dexamethasone concentrations. These results underscore the major difference between androstene hormone interactions with these nuclear receptors and their biological effects.

Hormone assay

International Nuclear Information System (INIS)

Eisentraut, A.M.

1977-01-01

An improved radioimmunoassay is described for measuring total triiodothyronine or total thyroxine levels in a sample of serum containing free endogenous thyroid hormone and endogenous thyroid hormone bound to thyroid hormone binding protein. The thyroid hormone is released from the protein by adding hydrochloric acid to the serum. The pH of the separated thyroid hormone and thyroid hormone binding protein is raised in the absence of a blocking agent without interference from the endogenous protein. 125 I-labelled thyroid hormone and thyroid hormone antibodies are added to the mixture, allowing the labelled and unlabelled thyroid hormone and the thyroid hormone antibody to bind competitively. This results in free thyroid hormone being separated from antibody bound thyroid hormone and thus the unknown quantity of thyroid hormone may be determined. A thyroid hormone test assay kit is described for this radioimmunoassay. It provides a 'single tube' assay which does not require blocking agents for endogenous protein interference nor an external solid phase sorption step for the separation of bound and free hormone after the competitive binding step; it also requires a minimum number of manipulative steps. Examples of the assay are given to illustrate the reproducibility, linearity and specificity of the assay. (UK)

Dual effect of melatonin on gonadotropin-releasing-hormone-induced Ca(2+) signaling in neonatal rat gonadotropes

Czech Academy of Sciences Publication Activity Database

Zemková, Hana; Vaněček, Jiří

2001-01-01

Roč. 74, č. 4 (2001), s. 262-269 ISSN 0028-3835 R&D Projects: GA ČR GA309/99/0213; GA ČR GA309/99/0215; GA AV ČR IAA5011103; GA AV ČR IAA5011105 Institutional research plan: CEZ:AV0Z5011922 Keywords : melatonin * gonadotropin-release hormone * calcium Subject RIV: FB - Endocrinology, Diabetology, Metabolism, Nutrition Impact factor: 2.144, year: 2001

Internal jugular vein: Peripheral vein adrenocorticotropic hormone ratio in patients with adrenocorticotropic hormone-dependent Cushing′s syndrome: Ratio calculated from one adrenocorticotropic hormone sample each from right and left internal jugular vein during corticotrophin releasing hormone stimulation test

Directory of Open Access Journals (Sweden)

Sachin Chittawar

2013-01-01

Full Text Available Background: Demonstration of central: Peripheral adrenocorticotropic hormone (ACTH gradient is important for diagnosis of Cushing′s disease. Aim: The aim was to assess the utility of internal jugular vein (IJV: Peripheral vein ACTH ratio for diagnosis of Cushing′s disease. Materials and Methods: Patients with ACTH-dependent Cushing′s syndrome (CS patients were the subjects for this study. One blood sample each was collected from right and left IJV following intravenous hCRH at 3 and 5 min, respectively. A simultaneous peripheral vein sample was also collected with each IJV sample for calculation of IJV: Peripheral vein ACTH ratio. IJV sample collection was done under ultrasound guidance. ACTH was assayed using electrochemiluminescence immunoassay (ECLIA. Results: Thirty-two patients participated in this study. The IJV: Peripheral vein ACTH ratio ranged from 1.07 to 6.99 ( n = 32. It was more than 1.6 in 23 patients. Cushing′s disease could be confirmed in 20 of the 23 cases with IJV: Peripheral vein ratio more than 1.6. Four patients with Cushing′s disease and 2 patients with ectopic ACTH syndrome had IJV: Peripheral vein ACTH ratio less than 1.6. Six cases with unknown ACTH source were excluded for calculation of sensitivity and specificity of the test. Conclusion: IJV: Peripheral vein ACTH ratio calculated from a single sample from each IJV obtained after hCRH had 83% sensitivity and 100% specificity for diagnosis of CD.

Synthesis of human pancreatic growth hormone-releasing factor and two omission analogs by segment-coupling method in aqueous solution

Energy Technology Data Exchange (ETDEWEB)

Blake, J.; Westphal, M.; Li, C.H. (Laboratory of Molecular Endocrinology, University of California, San Francisco, USA)

1984-01-01

The human growth hormone-releasing factor (GRF) peptides (GlyS/sup 15/)-GRF-(1-15) (IV), trifluoroacetyl-GRF-(20-44) (VI), trifluoroacetyl-GRF-(18-44) (VIII), and trifluoroacetyl-GRF-(16-44) (X) were synthesized by the solidphase method. Each of the peptides was reacted with citraconic anhydride and the trifluoroacetyl group was removed by reaction with 10% hydrazine in water. The citraconylated GRF-(1-15) peptide was coupled to the (20-44), (18-44) or (16-44) peptides by reaction with silver nitrate/N-hydroxysuccinimide to give GRF-(1-15)-(20-44) (XII), GRF-(1-15)-(18-44) (XIII), or GRF-(1-44), respectively. GRF-(1-44) was shown to stimulate the release of rat growth hormone from rat pituitary cells with an ED/sub 50/=8.8 x 10/sup -11/M. Peptides XII and XIII were inactive, either as agonists or as antagonists of the action of GRF-(1-44).

Epigenetic Programming of Synthesis, Release, and/or Receptor Expression of Common Mediators Participating in the Risk/Resilience for Comorbid Stress-Related Disorders and Coronary Artery Disease

Science.gov (United States)

Zapata-Martín del Campo, Carlos Manuel; Martínez-Rosas, Martín

2018-01-01

Corticotrophin releasing factor, vasopressin, oxytocin, natriuretic hormones, angiotensin, neuregulins, some purinergic substances, and some cytokines contribute to the long-term modulation and restructuring of cardiovascular regulation networks and, at the same time, have relevance in situations of comorbid abnormal stress responses. The synthesis, release, and receptor expression of these mediators seem to be under epigenetic control since early stages of life, possibly underlying the comorbidity to coronary artery disease (CAD) and stress-related disorders (SRD). The exposure to environmental conditions, such as stress, during critical periods in early life may cause epigenetic programming modifying the development of pathways that lead to stable and long-lasting alterations in the functioning of these mediators during adulthood, determining the risk of or resilience to CAD and SRD. However, in contrast to genetic information, epigenetic marks may be dynamically altered throughout the lifespan. Therefore, epigenetics may be reprogrammed if the individual accepts the challenge to undertake changes in their lifestyle. Alternatively, epigenetics may remain fixed and/or even be inherited in the next generation. In this paper, we analyze some of the common neuroendocrine functions of these mediators in CAD and SRD and summarize the evidence indicating that they are under early programming to put forward the theoretical hypothesis that the comorbidity of these diseases might be epigenetically programmed and modified over the lifespan of the individual. PMID:29670001

Epigenetic Programming of Synthesis, Release, and/or Receptor Expression of Common Mediators Participating in the Risk/Resilience for Comorbid Stress-Related Disorders and Coronary Artery Disease

Directory of Open Access Journals (Sweden)

Carlos Manuel Zapata-Martín del Campo

2018-04-01

Full Text Available Corticotrophin releasing factor, vasopressin, oxytocin, natriuretic hormones, angiotensin, neuregulins, some purinergic substances, and some cytokines contribute to the long-term modulation and restructuring of cardiovascular regulation networks and, at the same time, have relevance in situations of comorbid abnormal stress responses. The synthesis, release, and receptor expression of these mediators seem to be under epigenetic control since early stages of life, possibly underlying the comorbidity to coronary artery disease (CAD and stress-related disorders (SRD. The exposure to environmental conditions, such as stress, during critical periods in early life may cause epigenetic programming modifying the development of pathways that lead to stable and long-lasting alterations in the functioning of these mediators during adulthood, determining the risk of or resilience to CAD and SRD. However, in contrast to genetic information, epigenetic marks may be dynamically altered throughout the lifespan. Therefore, epigenetics may be reprogrammed if the individual accepts the challenge to undertake changes in their lifestyle. Alternatively, epigenetics may remain fixed and/or even be inherited in the next generation. In this paper, we analyze some of the common neuroendocrine functions of these mediators in CAD and SRD and summarize the evidence indicating that they are under early programming to put forward the theoretical hypothesis that the comorbidity of these diseases might be epigenetically programmed and modified over the lifespan of the individual.

Epigenetic Programming of Synthesis, Release, and/or Receptor Expression of Common Mediators Participating in the Risk/Resilience for Comorbid Stress-Related Disorders and Coronary Artery Disease.

Science.gov (United States)

Zapata-Martín Del Campo, Carlos Manuel; Martínez-Rosas, Martín; Guarner-Lans, Verónica

2018-04-18

Corticotrophin releasing factor, vasopressin, oxytocin, natriuretic hormones, angiotensin, neuregulins, some purinergic substances, and some cytokines contribute to the long-term modulation and restructuring of cardiovascular regulation networks and, at the same time, have relevance in situations of comorbid abnormal stress responses. The synthesis, release, and receptor expression of these mediators seem to be under epigenetic control since early stages of life, possibly underlying the comorbidity to coronary artery disease (CAD) and stress-related disorders (SRD). The exposure to environmental conditions, such as stress, during critical periods in early life may cause epigenetic programming modifying the development of pathways that lead to stable and long-lasting alterations in the functioning of these mediators during adulthood, determining the risk of or resilience to CAD and SRD. However, in contrast to genetic information, epigenetic marks may be dynamically altered throughout the lifespan. Therefore, epigenetics may be reprogrammed if the individual accepts the challenge to undertake changes in their lifestyle. Alternatively, epigenetics may remain fixed and/or even be inherited in the next generation. In this paper, we analyze some of the common neuroendocrine functions of these mediators in CAD and SRD and summarize the evidence indicating that they are under early programming to put forward the theoretical hypothesis that the comorbidity of these diseases might be epigenetically programmed and modified over the lifespan of the individual.

The role of dexamethasone in peripheral and neuraxial nerve blocks ...

African Journals Online (AJOL)

pain and prolongs analgesia in the postoperative period when combined with ... management of acute pain and that focused on dexamethasone's ability to prolong ... of dexamethasone to brachial plexus nerve blocks and Akram and Hassani ...

Dexamethasone and long-term outcome of tuberculous meningitis in Vietnamese adults and adolescents.

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M Estée Török

Full Text Available Dexamethasone has been shown to reduce mortality in patients with tuberculous meningitis but the long-term outcome of the disease is unknown.Vietnamese adults and adolescents with tuberculous meningitis recruited to a randomised, double-blind, placebo-controlled trial of adjunctive dexamethasone were followed-up at five years, to determine the effect of dexamethasone on long-term survival and neurological disability.545 patients were randomised to receive either dexamethasone (274 patients or placebo (271 patients. 50 patients (9.2% were lost to follow-up at five years. In all patients two-year survival, probabilities tended to be higher in the dexamethasone arm (0.63 versus 0.55; p = 0.07 but five-year survival rates were similar (0.54 versus 0.51, p = 0.51 in both groups. In patients with grade 1 TBM, but not with grade 2 or grade 3 TBM, the benefit of dexamethasone treatment tended to persist over time (five-year survival probabilities 0.69 versus 0.55, p = 0.07 but there was no conclusive evidence of treatment effect heterogeneity by TBM grade (p = 0.36. The dexamethasone group had a similar proportion of severely disabled patients among survivors at five years as the placebo group (17/128, 13.2% vs. 17/116, 14.7% and there was no significant association between dexamethasone treatment and disability status at five years (p = 0.32.Adjunctive dexamethasone appears to improve the probability of survival in patients with TBM, until at least two years of follow-up. We could not demonstrate a five-year survival benefit of dexamethasone treatment which may be confined to patients with grade 1 TBM.ClinicalTrials.gov NCT01317654.

Hypertrophic Cardiomyopathy After a Single Dose of Dexamethasone in a Preterm Infant

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Yusuf Kale

2015-08-01

Full Text Available Dexamethasone is widely used in preterm infants with severe pulmonary disease. Hypertrophic cardiomyopathy (HCM is a transient side effect observed after multiple doses of dexamethasone. We report a preterm infant with myocardial hypertrophy after a single dose of dexamethasone (0.5 mg/kg used to treat laryngeal edema secondary to prolonged intubation. A benign course was observed without left ventricular outflow tract obstruction and with recovery within 4 weeks. Myocardial effects of dexamethasone may be independent of dose and duration of treatment. The risk/benefit ratio must be carefully considered before using even a single dose of dexamethasone in preterm infants.

Elevated mRNA-levels of gonadotropin-releasing hormone and its receptor in plaque-bearing Alzheimer's disease transgenic mice.

Directory of Open Access Journals (Sweden)

Syed Nuruddin

Full Text Available Research on Alzheimer's disease (AD has indicated an association between hormones of the hypothalamic-pituitary-gonadal (HPG axis and cognitive senescence, indicating that post meno-/andropausal changes in HPG axis hormones are implicated in the neuropathology of AD. Studies of transgenic mice with AD pathologies have led to improved understanding of the pathophysiological processes underlying AD. The aims of this study were to explore whether mRNA-levels of gonadotropin-releasing hormone (Gnrh and its receptor (Gnrhr were changed in plaque-bearing Alzheimer's disease transgenic mice and to investigate whether these levels and amyloid plaque deposition were downregulated by treatment with a gonadotropin-releasing hormone analog (Gnrh-a; Leuprorelin acetate. The study was performed on mice carrying the Arctic and Swedish amyloid-β precursor protein (AβPP mutations (tgArcSwe. At 12 months of age, female tgArcSwe mice showed a twofold higher level of Gnrh mRNA and more than 1.5 higher level of Gnrhr mRNA than age matched controls. Male tgArcSwe mice showed the same pattern of changes, albeit more pronounced. In both sexes, Gnrh-a treatment caused significant down-regulation of Gnrh and Gnrhr mRNA expression. Immunohistochemistry combined with quantitative image analysis revealed no significant changes in the plaque load after Gnrh-a treatment in hippocampus and thalamus. However, plaque load in the cerebral cortex of treated females tended to be lower than in female vehicle-treated mice. The present study points to the involvement of hormonal changes in AD mice models and demonstrates that these changes can be effectively counteracted by pharmacological treatment. Although known to increase in normal aging, our study shows that Gnrh/Gnrhr mRNA expression increases much more dramatically in tgArcSwe mice. Treatment with Leuprorelin acetate successfully abolished the transgene specific effects on Gnrh/Gnrhr mRNA expression. The present experimental

Inhibition of growth of experimental prostate cancer with sustained delivery systems (microcapsules and microgranules) of the luteinizing hormone-releasing hormone antagonist SB-75.

Science.gov (United States)

Korkut, E; Bokser, L; Comaru-Schally, A M; Groot, K; Schally, A V

1991-02-01

Inhibitory effects of the sustained delivery systems (microcapsules and microgranules) of a potent antagonist of luteinizing hormone-releasing hormone N-Ac-[3-(2-naphthyl)-D-alanine1, 4-chloro-D-phenylalanine2, 3-(3-pyridyl)-D-alanine3, D-citrulline6, D-alanine10]LH-RH (SB-75) on the growth of experimental prostate cancers were investigated. In the first experiment, three doses of a microcapsule preparation releasing 23.8, 47.6, and 71.4 micrograms of antagonist SB-75 per day were compared with microcapsules of agonist [D-Trp6]LH-RH liberating 25 micrograms/day in rats bearing Dunning R3327H transplantable prostate carcinoma. During 8 weeks of treatment, tumor growth was decreased by [D-Trp6]LH-RH and all three doses of SB-75 as compared to untreated controls. The highest dose of SB-75 (71.4 micrograms/day) caused a greater inhibition of prostate cancer growth than [D-Trp6]LH-RH as based on measurement of tumor volume and percentage change in tumor volume. Doses of 23.8 and 47.6 micrograms of SB-75 per day induced a partial and submaximal decrease, respectively, in tumor weight and volume. Tumor doubling time was the longest (50 days) with the high dose of SB-75 vs. 15 days for controls. The body weights were unchanged. The weights of testes, seminal vesicles, and ventral prostate were greatly reduced in all three groups that received SB-75, and testosterone levels were decreased to nondetectable values in the case of the two higher doses of SB-75. LH levels were also diminished. Similar results were obtained in the second experiment, in which the animals were treated for a period of 8 weeks with microgranules of SB-75. Therapy with microgranules of SB-75 significantly decreased tumor growth as measured by the final tumor volume, the percentage change from the initial tumor volume, and the reduction in tumor weight. The results indicate that antagonist SB-75, released from sustained delivery systems, can produce a state of chemical castration and effectively

Hyperthyroidism and acromegaly due to a thyrotropin- and growth hormone-secreting pituitary tumor. Lack of hormonal response to bromocriptine.

Science.gov (United States)

Carlson, H E; Linfoot, J A; Braunstein, G D; Kovacs, K; Young, R T

1983-05-01

A 47-year-old woman with acromegaly and hyperthyroidism was found to have an inappropriately normal serum thyrotropin level (1.5 to 2.5 microU/ml) that responded poorly to thyrotropin-releasing hormone but showed partial responsiveness to changes in circulating thyroid hormones. Serum alpha-subunit levels were high-normal and showed a normal response to thyrotropin-releasing hormone. Growth hormone and thyrotropin hypersecretion persisted despite radiotherapy and bromocriptine treatment. Selective trans-sphenoidal removal of a pituitary adenoma led to normalization of both growth hormone and thyrotropin levels. Both thyrotropes and somatotropes were demonstrated in the adenoma by the immunoperoxidase technique and electron microscopy.

Asprosin, a fasting-induced glucogenic protein hormone

Science.gov (United States)

Hepatic glucose release into the circulation is vital for brain function and survival during periods of fasting and is modulated by an array of hormones that precisely regulate plasma glucose levels. We have identified a fasting-induced protein hormone that modulates hepatic glucose release. It is t...

Gonadotropin-releasing hormone analogues inhibit leiomyoma extracellular matrix despite presence of gonadal hormones.

Science.gov (United States)

Malik, Minnie; Britten, Joy; Cox, Jeris; Patel, Amrita; Catherino, William H

2016-01-01

To determine the effect of GnRH analogues (GnRH-a) leuprolide acetate (LA) and cetrorelix acetate on gonadal hormone-regulated expression of extracellular matrix in uterine leiomyoma three-dimensional (3D) cultures. Laboratory study. University research laboratory. Women undergoing hysterectomy for symptomatic leiomyomas. The 3D cell cultures, protein analysis, Western blot, immunohistochemistry. Expression of extracellular matrix proteins, collagen 1, fibronectin, and versican in leiomyoma cells 3D cultures exposed to E2, P, LA, cetrorelix acetate, and combinations for 24- and 72-hour time points. The 3D leiomyoma cultures exposed to E2 for 24 hours demonstrated an increased expression of collagen-1 and fibronectin, which was maintained for up to 72 hours, a time point at which versican was up-regulated significantly. Although P up-regulated collagen-1 protein (1.29 ± 0.04) within 24 hours of exposure, significant increase in all extracellular matrix (ECM) proteins was observed when the gonadal hormones were used concomitantly. Significant decrease in the amount of ECM proteins was observed on use of GnRH-a, LA and cetrorelix, with 24-hour exposure. Both the compounds also significantly decreased ECM protein concentration despite the presence of E2 or both gonadal hormones. This study demonstrates that GnRH-a directly affect the gonadal hormone-regulated collagen-1, fibronectin, and versican production in their presence. These findings suggest that localized therapy with GnRH-a may inhibit leiomyoma growth even in the presence of endogenous gonadal hormone exposure, thereby providing a mechanism to eliminate the hypoestrogenic side effects associated with GnRH-a therapy. Published by Elsevier Inc.

Radioimmunological studies of the thyrotropic function of the hypophysis under the effect of the thyrotropin-releasing hormone in thyroid diseases

International Nuclear Information System (INIS)

Vakulenko, A.D.; Matveenko, E.G.; Simakova, G.M.; Sorokina, V.G.; Golubnichaya, L.P.; Dobrova, G.S.

1979-01-01

The synthetic thyrotropin-releasing-hormone was stream-injected intravenously to 124 patients and 16 healthy people in doses of 200 μg. It was tolerated satisfactorily at the first and repeated injections. The radioimmunologic method was used prior to the test and 30 min after it to examine thyrotropin content in blood. In normal state the stimulation would result in 3.5-fold increase in thyrotropin level on the average. The hypophysial reserve of thyrotropin was significantly lower in cases of diffuse toxic goiter in grave and semigrave forms and toxic adenoma. It was significantly higher at primary hypothyrosis and retained at nodular euthyroid goiter, neupocirculatopy dystonia and mild thyrotoxicosis. At thyroid gland disturbances the test with thyrotropin-releasing-hormone is of diagnostic value at primary hypothyrosis in the initial latent period; besides, it can be used for control of substitution therapy and as a supplementary test at thyrotoxicosis

Ghrelin: much more than a hunger hormone

Science.gov (United States)

Ghrelin is a multifaceted gut hormone that activates its receptor, growth hormone secretagogue receptor (GHS-R). Ghrelin's hallmark functions are its stimulatory effects on growth hormone release, food intake and fat deposition. Ghrelin is famously known as the 'hunger hormone'. However, ample recen...

Dexamethasone and Long-Term Outcome of Tuberculous Meningitis in Vietnamese Adults and Adolescents

Science.gov (United States)

Török, M. Estée; Bang, Nguyen Duc; Chau, Tran Thi Hong; Yen, Nguyen Thi Bich; Thwaites, Guy E.; Thi Quy, Hoang; Dung, Nguyen Huy; Hien, Tran Tinh; Chinh, Nguyen Tran; Thi Thanh Hoang, Hoang; Wolbers, Marcel; Farrar, Jeremy J.

2011-01-01

Background Dexamethasone has been shown to reduce mortality in patients with tuberculous meningitis but the long-term outcome of the disease is unknown. Methods Vietnamese adults and adolescents with tuberculous meningitis recruited to a randomised, double-blind, placebo-controlled trial of adjunctive dexamethasone were followed-up at five years, to determine the effect of dexamethasone on long-term survival and neurological disability. Results 545 patients were randomised to receive either dexamethasone (274 patients) or placebo (271 patients). 50 patients (9.2%) were lost to follow-up at five years. In all patients two-year survival, probabilities tended to be higher in the dexamethasone arm (0.63 versus 0.55; p = 0.07) but five-year survival rates were similar (0.54 versus 0.51, p = 0.51) in both groups. In patients with grade 1 TBM, but not with grade 2 or grade 3 TBM, the benefit of dexamethasone treatment tended to persist over time (five-year survival probabilities 0.69 versus 0.55, p = 0.07) but there was no conclusive evidence of treatment effect heterogeneity by TBM grade (p = 0.36). The dexamethasone group had a similar proportion of severely disabled patients among survivors at five years as the placebo group (17/128, 13.2% vs. 17/116, 14.7%) and there was no significant association between dexamethasone treatment and disability status at five years (p = 0.32). Conclusions Adjunctive dexamethasone appears to improve the probability of survival in patients with TBM, until at least two years of follow-up. We could not demonstrate a five-year survival benefit of dexamethasone treatment which may be confined to patients with grade 1 TBM. Trial Registration ClinicalTrials.gov NCT01317654 NCT01317654?term = tuberculous+meningitis&rank = 3 PMID:22174748

Prolactin response to thyrotropin-releasing hormone in early and advanced human breast cancer

International Nuclear Information System (INIS)

Barni, S.; Lissoni, P.; Tancini, G.

1986-01-01

While prolactin (PRL) has been shown to stimulate the development of mammary carcinoma in several animal species, its role in human breast cancer remains to be established. To further investigate PRL secretion in human breast cancer, its basal levels and response to thyrotropin-releasing hormone (TRH) were evaluated in 16 patients (6 with no metastases and 10 with metastatic locations). The control group consisted of 19 healthy women. High PRL basal concentrations were seen in 2 patients only; no significant differences were found between the other patients and the normal subjects. The PRL increase induced by TRH administration was significantly higher in patients than in controls. Finally a change in the hormonal secretion was found after chemotherapy in 3 of the 5 patients in whom PRL response to TRH was evaluated either before or 10-12 days after a cycle of intravenous CMF adjuvant chemotherapy. These results demostrate the existence of an exaggerated response of PRL to TRH in patients with breast cancer, even in the presence of normal basal levels. Moreover, they would seem to suggest a possible influence of CMF on PRL response to TRH stimulation

Development and characterization of nanoparticulate formulation of a water soluble prodrug of dexamethasone by HIP complexation.

Science.gov (United States)

Gaudana, Ripal; Parenky, Ashwin; Vaishya, Ravi; Samanta, Swapan K; Mitra, Ashim K

2011-01-01

The objective of this study was to develop and characterize a nanoparticulate-based sustained release formulation of a water soluble dipeptide prodrug of dexamethasone, valine-valine-dexamethasone (VVD). Being hydrophilic in nature, it readily leaches out in the external aqueous medium and hence partitions poorly into the polymeric matrix resulting in minimal entrapment in nanoparticles. Hence, hydrophobic ion pairing (HIP) complexation of the prodrug was employed with dextran sulphate as a complexing polymer. A novel, solid in oil in water emulsion method was employed to encapsulate the prodrug in HIP complex form in poly(lactic-co-glycolic acid) matrix. Nanoparticles were characterized with respect to size, zeta potential, crystallinity of entrapped drug and surface morphology. A significant enhancement in the entrapment of the prodrug in nanoparticles was achieved. Finally, a simple yet novel method was developed which can also be applicable to encapsulate other charged hydrophilic molecules, such as peptides and proteins.

The estrogen myth: potential use of gonadotropin-releasing hormone agonists for the treatment of Alzheimer's disease.

Science.gov (United States)

Casadesus, Gemma; Garrett, Matthew R; Webber, Kate M; Hartzler, Anthony W; Atwood, Craig S; Perry, George; Bowen, Richard L; Smith, Mark A

2006-01-01

Estrogen and other sex hormones have received a great deal of attention for their speculative role in Alzheimer's disease (AD), but at present a direct connection between estrogen and the pathogenesis of AD remains elusive and somewhat contradictory. For example, on one hand there is a large body of evidence suggesting that estrogen is neuroprotective and improves cognition, and that hormone replacement therapy (HRT) at the onset of menopause reduces the risk of developing AD decades later. However, on the other hand, studies such as the Women's Health Initiative demonstrate that HRT initiated in elderly women increases the risk of dementia. While estrogen continues to be investigated, the disparity of findings involving HRT has led many researchers to examine other hormones of the hypothalamic-pituitary-gonadal axis such as luteinising hormone (LH) and follicle-stimulating hormone. In this review, we propose that LH, rather than estrogen, is the paramount player in the pathogenesis of AD. Notably, both men and women experience a 3- to 4-fold increase in LH with aging, and LH receptors are found throughout the brain following a regional pattern remarkably similar to those neuron populations affected in AD. With respect to disease, serum LH level is increased in women with AD relative to non-diseased controls, and levels of LH in the brain are also elevated in AD. Mechanistically, we propose that elevated levels of LH may be a fundamental instigator responsible for the aberrant reactivation of the cell cycle that is seen in AD. Based on these aforementioned aspects, clinical trials underway with leuprolide acetate, a gonadotropin-releasing hormone agonist that ablates serum LH levels, hold great promise as a ready means of treatment in individuals afflicted with AD.

Alterations in the corticotropin-releasing hormone (CRH) neurocircuitry: Insights into post stroke functional impairments.

Science.gov (United States)

Barra de la Tremblaye, P; Plamondon, H

2016-07-01

Although it is well accepted that changes in the regulation of the hypothalamic-pituitary adrenal (HPA) axis may increase susceptibility to affective disorders in the general population, this link has been less examined in stroke patients. Yet, the bidirectional association between depression and cardiovascular disease is strong, and stress increases vulnerability to stroke. Corticotropin-releasing hormone (CRH) is the central stress hormone of the HPA axis pathway and acts by binding to CRH receptors (CRHR) 1 and 2, which are located in several stress-related brain regions. Evidence from clinical and animal studies suggests a role for CRH in the neurobiological basis of depression and ischemic brain injury. Given its importance in the regulation of the neuroendocrine, autonomic, and behavioral correlates of adaptation and maladaptation to stress, CRH is likely associated in the pathophysiology of post stroke emotional impairments. The goals of this review article are to examine the clinical and experimental data describing (1) that CRH regulates the molecular signaling brain circuit underlying anxiety- and depression-like behaviors, (2) the influence of CRH and other stress markers in the pathophysiology of post stroke emotional and cognitive impairments, and (3) context and site specific interactions of CRH and BDNF as a basis for the development of novel therapeutic targets. This review addresses how the production and release of the neuropeptide CRH within the various regions of the mesocorticolimbic system influences emotional and cognitive behaviors with a look into its role in psychiatric disorders post stroke. Copyright © 2016 Elsevier Inc. All rights reserved.

Effect of dexamethasone in primary intracerebral hemorrhage in the south west of iran

International Nuclear Information System (INIS)

Sharafadinzadeh, N.; Baghebanian, S.M.; Pipelzadeh, M.; Moravej, A. A.; Ghanavatiz, P.

2008-01-01

Previous study revealed the value of dexamethasone in the treatment of vasogenic edema associated with brain tumor and abscess. However there are poor documented studies about its usefulness in primary intracerebral hemorrhage. In this study we evaluated dexamethasone effects in primary intracerebral hemorrhage. In a double blind randomized placebo-controlled clinical trial we evaluated 200 intracerebral hemorrhage cases between 40 to 80 years old whom were admitted at Golestan Hospital (Ahwaz, IR) between March 2002 and March 2003. They were divided in two groups dexamethasone (N=100) and placebo (N=100). Then mortality, GI bleeding, fever, electrolytes disturbances, hypertension and hyperglycemic status were analyzed in two groups. Ethical considerations were employed and subjects were followed by appropriate statistical methods for 21 days to assess the major outcomes. Mortality was much higher in the dexamethasone group; Dexamethasone group (49.3%) and placebo (23.4%) and also fever was higher seen in the dexamethasone group; dexamethasone group (40.2%) and placebo group (24.7%) but there was not any significant statistical difference between two groups as regards other complications. Dexamethasone is widely used for cerebral edema associated conditions but in this study we saw that it's complications in intracerebral hemorrhage such as increasing fever and mortality are significantly higher. Hence it use for treatment of primary intracerebral hemorrhage should be reconsidered. (author)

Effects of glucocorticoid hormones on radiation induced and 12-O-tetradecanoylphorbol-13-acetate enhanced radiation transformation in vitro

International Nuclear Information System (INIS)

Kennedy, A.R.; Umans, R.S.

1988-01-01

We have studied the interactions of glucocorticoid hormones with radiation in the induction of transformation in vitro in C3AH10T1/2 cells. We have observed that cortisone has its primary enhancing effect on radiation transformation when present after the radiation exposure during the ''expression period'', or the time after carcinogen exposure during which promoting agents have been shown to enhance radiation transformation in vitro, and that two different glucocorticoid hormones, dexamethasone and cortisone, have a suppressive effect on the 12-O-tetradecanoylphorbol-13-acetate (TPA) enhancement of radiation transformation in vitro

β-Hydroxy-β-methylbutyrate (HMB) prevents dexamethasone-induced myotube atrophy.

Science.gov (United States)

Aversa, Zaira; Alamdari, Nima; Castillero, Estibaliz; Muscaritoli, Maurizio; Rossi Fanelli, Filippo; Hasselgren, Per-Olof

2012-07-13

High levels of glucocorticoids result in muscle wasting and weakness. β-hydroxy-β-methylbutyrate (HMB) attenuates the loss of muscle mass in various catabolic conditions but the influence of HMB on glucocorticoid-induced muscle atrophy is not known. We tested the hypothesis that HMB prevents dexamethasone-induced atrophy in cultured myotubes. Treatment of cultured L6 myotubes with dexamethasone resulted in increased protein degradation and expression of atrogin-1 and MuRF1, decreased protein synthesis and reduced myotube size. All of these effects of dexamethasone were attenuated by HMB. Additional experiments provided evidence that the inhibitory effects of HMB on dexamethasone-induced increase in protein degradation and decrease in protein synthesis were regulated by p38/MAPK- and PI3K/Akt-dependent cell signaling, respectively. The present results suggest that glucocorticoid-induced muscle wasting can be prevented by HMB. Copyright © 2012 Elsevier Inc. All rights reserved.

Dexamethasone Treatment Reverses Cognitive Impairment but Increases Brain Oxidative Stress in Rats Submitted to Pneumococcal Meningitis

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Tatiana Barichello

2011-01-01

Full Text Available Pneumococcal meningitis is associated with a significant mortality rate and neurologic sequelae. The animals received either 10 μL of saline or a S. pneumoniae suspension and were randomized into different groups: sham: placebo with dexamethasone 0.7 mg/kg/1 day; placebo with dexamethasone 0.2 mg/kg/7 days; meningitis groups: dexamethasone 0.7 mg/kg/1 day and dexamethasone 0.2 mg/kg/7 days. Ten days after induction we evaluated memory and oxidative stress parameters in hippocampus and cortex. In the step-down inhibitory avoidance task, we observed memory impairment in the meningitis group with dexamethasone 0.2 mg/kg/7 days. The lipid peroxidation was increased in hippocampus in the meningitis groups with dexamethasone and in cortex only in the meningitis group with dexamethasone 0.2 mg/kg/7 days. The protein carbonyl was increased in hippocampus in the meningitis groups with dexamethasone and in cortex in the meningitis groups with and without dexamethasone. There was a decrease in the proteins integrity in hippocampus in all groups receiving treatment with dexamethasone and in cortex in all groups with dexamethasone (0.7 mg/kg/1 day. The mitochondrial superoxide was increased in the hippocampus and cortex in the meningitis group with dexamethasone 0.2 mg/kg/7 days. Our findings demonstrate that dexamethasone reverted cognitive impairment but increased brain oxidative stress in hippocampus and cortex in Wistar rats ten days after pneumococcal meningitis induction.

A different approach to the radioimmunoassay of thyrotropin releasing hormone

International Nuclear Information System (INIS)

Visser, T.J.; Klootwijk, W.; Docter, R.; Hennemann, G.

1977-01-01

Thyrotropin releasing hormone (TRH) was linked to hemocyanin by means of a dinitrophenylene moiety. TRH (pGlu-His-Pro-NH 2 ) was made to react with a large excess of 1,5-difluoro-2,4-dinitrobenzene to yield Nsup(im)-[5-fluoro-2,4-dinitrophenyl]TRH. After removal of excess reagent the derivative was coupled to hemocyanin with a minimum of side-reactions. From two rabbits out of four immunized with this material valuable antisera were obtained, which were used in the radioimmunoassay of the hypothalamic hormone at a final dilution of 1:7,500 and 1:15,000, respectively. The properties, especially with regard to specificity, of these antisera were studied and compared with another antiserum, which was obtained using a conjugate having TRH linked to thyroglobulin via a p-azophenyl-acetyl moiety. Despite the difference between the derivatives, i.e. the nature and the point of attachment of the side chains, the specificities of the assays were very similar. Deamidation of TRH, deletion of either one of the terminal residues, hydrolysis of the lactam of the pyroglutamyl residue, and replacing Pro-NH 2 by Pro-Gly-NH 2 or by an octapeptide chain yield peptides with strongly diminished cross-reactivities. However, Nsup(im)-benzyl-TRH and pGlu-Phe-Pro-NH 2 were 5-10 times as active as TRH probably due to a closer physico-chemical similarity to the arrangement of the haptens in the conjugates. This suggests that the sensitivity of the radioimmunoassay may be increased markedly by conversion of TRH into the Nsup(im)-dinitrophenyl derivative and by using a related compound for radioiodination. (orig.) [de

Dexamethasone, Intravenous Immunoglobulin, and Rituximab Combination Immunotherapy for Pediatric Opsoclonus-Myoclonus Syndrome.

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Pranzatelli, Michael R; Tate, Elizabeth D

2017-08-01

Although pulse-dose dexamethasone is increasingly favored for treating pediatric opsoclonus-myoclonus syndrome (OMS), and multimodal immunotherapy is associated with improved clinical response, there have been no neuroimmunologic studies of dexamethasone-based multimodal disease-modifying therapy. In this observational retrospective study, 19 children with OMS (with or without associated neuroblastoma) underwent multibiomarker evaluation for neuroinflammation. Nine children of varying OMS severity, duration, and treatment status were treated empirically with pulse dexamethasone, intravenous immunoglobulin (IVIg), and rituximab combination immunotherapy (DEXIR-CI). Another 10 children on dexamethasone alone or with IVIg at initial evaluation only provided a comparison group. Motor severity (total score) was scored rater-blinded via videotapes using the validated OMS Evaluation Scale. DEXIR-CI was associated with a 69% reduction in group total score (P = 0.004) and was clinically well tolerated. Patients given the dexamethasone combination exhibited significantly lowered B cell frequencies in cerebrospinal fluid (-94%) and blood (-76%), normalizing the cerebrospinal fluid B cell percentage. The number of patients with positive inflammatory markers dropped 87% (P = 0.002) as did the number of markers. Cerebrospinal fluid oligoclonal bands were positive in four of nine pretreatment patients but zero of six post-treatment patients. In the comparison group, partial response to dexamethasone alone or with IVIg was associated with multiple positive markers for neuroinflammation despite an average of seven months of treatment. Multimechanistic dexamethasone-based combination immunotherapy increases the therapeutic armamentarium for OMS, providing a viable option for less severely affected individuals. Partial response to dexamethasone with or without IVIg is indicative of ongoing neuroinflammation and should be treated promptly and accordingly. Copyright © 2017

Enhanced Anti-Tumoral Activity of Methotrexate-Human Serum Albumin Conjugated Nanoparticles by Targeting with Luteinizing Hormone-Releasing Hormone (LHRH) Peptide

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Taheri, Azade; Dinarvand, Rassoul; Atyabi, Fatemeh; Ahadi, Fatemeh; Nouri, Farank Salman; Ghahremani, Mohammad Hossein; Ostad, Seyed Nasser; Borougeni, Atefeh Taheri; Mansoori, Pooria

2011-01-01

Active targeting could increase the efficacy of anticancer drugs. Methotrexate-human serum albumin (MTX-HSA) conjugates, functionalized by luteinizing hormone-releasing hormone (LHRH) as targeting moieties, with the aim of specifically targeting the cancer cells, were prepared. Owing to the high expression of LHRH receptors in many cancer cells as compared to normal cells, LHRH was used as the targeting ligand in this study. LHRH was conjugated to MTX-HSA nanoparticles via a cross-linker. Three types of LHRH targeted nanoparticles with a mean particle size between 120–138 nm were prepared. The cytotoxicity of LHRH targeted and non-targeted nanoparticles were determined on the LHRH positive and negative cell lines. The internalization of the targeted and non-targeted nanoparticles in LHRH receptor positive and negative cells was investigated using flow cytometry analysis and fluorescence microscopy. The cytotoxicity of the LHRH targeted nanoparticles on the LHRH receptor positive cells were significantly more than non-targeted nanoparticles. LHRH targeted nanoparticles were also internalized by LHRH receptor positive cells significantly more than non-targeted nanoparticles. There were no significant differences between the uptake of targeted and non-targeted nanoparticles to the LHRH receptor negative cells. The active targeting procedure using LHRH targeted MTX-HSA nanoparticles could increase the anti-tumoral activity of MTX. PMID:21845098

Sustained Administration of Hormones Exploiting Nanoconfined Diffusion through Nanochannel Membranes

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Thomas Geninatti

2015-08-01

Full Text Available Implantable devices may provide a superior means for hormone delivery through maintaining serum levels within target therapeutic windows. Zero-order administration has been shown to reach an equilibrium with metabolic clearance, resulting in a constant serum concentration and bioavailability of released hormones. By exploiting surface-to-molecule interaction within nanochannel membranes, it is possible to achieve a long-term, constant diffusive release of agents from implantable reservoirs. In this study, we sought to demonstrate the controlled release of model hormones from a novel nanochannel system. We investigated the delivery of hormones through our nanochannel membrane over a period of 40 days. Levothyroxine, osteocalcin and testosterone were selected as representative hormones based on their different molecular properties and structures. The release mechanisms and transport behaviors of these hormones within 3, 5 and 40 nm channels were characterized. Results further supported the suitability of the nanochannels for sustained administration from implantable platforms.

Pregabalin and dexamethasone improves post-operative pain treatment after tonsillectomy

DEFF Research Database (Denmark)

Mathiesen, O; Jørgensen, D G; Hilsted, K L

2011-01-01

Post-tonsillectomy pain can be severe. We investigated the analgesic effect from combinations of paracetamol, pregabalin and dexamethasone in adults undergoing tonsillectomy.......Post-tonsillectomy pain can be severe. We investigated the analgesic effect from combinations of paracetamol, pregabalin and dexamethasone in adults undergoing tonsillectomy....

Menstruation recovery after chemotherapy and luteinizing hormone-releasing hormone agonist plus tamoxifen therapy for premenopausal patients with breast cancer.

Science.gov (United States)

Sakurai, Kenichi; Matsuo, Sadanori; Enomoto, Katsuhisa; Amano, Sadao; Shiono, Motomi

2011-01-01

Little is known about the period required for menstruation recovery after long-term luteinizing hormone-releasing hormone (LH-RH) agonist plus tamoxifen therapy following chemotherapy. In this study we investigated the period required for menstruation recovery after the therapy. The subjects comprised 105 premenopausal breast cancer patients who had undergone surgery. All patients were administered an LH-RH agonist for 24 months and tamoxifen for 5 years following the postoperative adjuvant chemotherapy, and the status of menstruation recovery was examined. Menstruation resumed in 16 cases (15.2%) after the last LH-RH agonist treatment session. The mean period from the last LH-RH agonist treatment to the recovery of menstruation was 6.9 months. The rate of menstruation recovery was 35.5% in patients aged 40 years or younger and 8.0% in those aged 41 years or older, and it was significantly higher in those aged 40 years or younger. The period until menstruation recovery tended to be longer in older patients at the end of treatment. This study showed that menstruation resumed after treatment at higher rates in younger patients. However, because it is highly likely that ovarian function will be destroyed by the treatment even in young patients, it is considered necessary to explain the risk to patients and obtain informed consent before introducing this treatment modality.

Accelerated in vitro release testing of implantable PLGA microsphere/PVA hydrogel composite coatings.

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Shen, Jie; Burgess, Diane J

2012-01-17

Dexamethasone loaded poly(lactic-co-glycolic acid) (PLGA) microsphere/PVA hydrogel composites have been investigated as an outer drug-eluting coating for implantable devices such as glucose sensors to counter negative tissue responses to implants. The objective of this study was to develop a discriminatory, accelerated in vitro release testing method for this drug-eluting coating using United States Pharmacopeia (USP) apparatus 4. Polymer degradation and drug release kinetics were investigated under "real-time" and accelerated conditions (i.e. extreme pH, hydro-alcoholic solutions and elevated temperatures). Compared to "real-time" conditions, the initial burst and lag phases were similar using hydro-alcoholic solutions and extreme pH conditions, while the secondary apparent zero-order release phase was slightly accelerated. Elevated temperatures resulted in a significant acceleration of dexamethasone release. The accelerated release data were able to predict "real-time" release when applying the Arrhenius equation. Microsphere batches with faster and slower release profiles were investigated under "real-time" and elevated temperature (60°C) conditions to determine the discriminatory ability of the method. The results demonstrated both the feasibility and the discriminatory ability of this USP apparatus 4 method for in vitro release testing of drug loaded PLGA microsphere/PVA hydrogel composites. This method may be appropriate for similar drug/device combination products and drug delivery systems. Copyright © 2011 Elsevier B.V. All rights reserved.

Radioiodinated nondegradable gonadotropin-releasing hormone analogs: new probes for the investigation of pituitary gonadotropin-releasing hormone receptors.

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Clayton, R N; Shakespear, R A; Duncan, J A; Marshall, J C; Munson, P J; Rodbard, D

1979-12-01

Studies of pituitary plasma membrane gonadotropin-releasing hormone (GnRH) receptors using [125I]-iodo-GnRH suffer major disadvantages. Only a small (less than 25%) proportion of specific tracer binding is to high affinity sites, with more than 70% bound to low affinity sites (Ka = 1 x 10(6) M-1). [125I]Iodo-GnRH is also inactivated during incubation with pituitary plasma membrane preparations. Two superactive analongs of GnRH, substituted in positions 6 and 10, were used as the labeled ligand to overcome these problems. Both analogs bound to the same high affinity sites as GnRH on bovine pituitary plasma membranes, though the affinity of the analogs was higher than that of the natural decapeptide (Ka = 2.0 x 10(9), 6.0 x 10(9), and 3.0 x 10(8) M-1 for [D-Ser(TBu)6]des-Gly10-GnRH ethylamide, [D-Ala6]des-Gly10-GnRH ethylamide, and GnRH, respectively. The labeled analogs bound to a single class of high affinity sites with less than 15% of the specific binding being to low affinity sites (Ka approximately equal to 1 x 10(6) M-1). The labeled analogs were not inactivated during incubation with the pituitary membrane preparations. Using the analogs as tracer, a single class of high affinity sites (K1 = 4.0 x 10(9) M-1) was also demonstrated on crude 10,800 x g rat pituitary membrane preparations. Use of these analogs as both the labeled and unlabeled ligand offers substantial advantages over GnRH for investigation of GnRH receptors, allowing accurate determination of changes in their numbers and affinities under various physiological conditions.

Peptide Hormones in the Gastrointestinal Tract

DEFF Research Database (Denmark)

Rehfeld, Jens F.

2015-01-01

Gastrointestinal hormones are peptides released from endocrine cells and neurons in the digestive tract. More than 30 hormone genes are currently known to be expressed in the gastrointestinal tract, which makes the gut the largest hormone-producing organ in the body. Modern biology makes it feasi...

Synthesis and in vitro and in vivo activity of analogs of growth hormone-releasing hormone (GH-RH) with C-terminal agmatine.

Science.gov (United States)

Zarandi, M; Csernus, V; Bokser, L; Bajusz, S; Groot, K; Schally, A V

1990-12-01

In the search for more active analogs of human growth hormone-releasing hormone (GH-RH), 37 new compounds were synthesized by solid phase methodology, purified, and tested biologically. Most of the analogs contained a sequence of 27 amino acids and N-terminal desaminotyrosine (Dat) and C-terminal agmatine (Agm), which are not amino acids. In addition to Dat in position 1 and Agm in position 29, the majority of the analogs had Ala15 and Nle27 substitutions and one or more additional L- or D-amino acid modifications. [Dat1, Ala15, Nle27]GH-RH(1-28)Agm (MZ-2-51) was the most active analog. Its in vitro GH-releasing potency was 10.5 times higher than that of GH-RH(1-29)NH2 and in the i.v. in vivo assay, MZ-2-51 was 4-5 times more active than the standard. After s.c. administration to rats. MZ-2-51 showed an activity 34 times higher at 15 min and 179 times greater at 30 min than GH-RH(1-29)NH2 and also displayed a prolonged activity. D-Tyr10, D-Lys12, and D-Lys21 homologs of MZ-2-51 also showed enhanced activities. Thus, [Dat1, D-Tyr10, Ala15, Nle27]GH-RH(1-28)Agm (MZ-2-159), [Dat1, D-Lys12, Ala15, Nle27]GH-RH(1-28)AGM (MZ-2-57), and [Dat1, Ala15, D-Lys21, Nle27]GH-RH(1-28)Agm (MZ-2-75) were 4-6 times more active in vitro than GH-RH(1-29)NH2. In vivo, after i.v. administration, analog MZ-2-75 was equipotent and analogs MZ-2-159 and MZ-2-57 about twice as potent as the standard.(ABSTRACT TRUNCATED AT 250 WORDS)

Radioimmunoassay of plasma corticotrophin

International Nuclear Information System (INIS)

Hummer, L.

1977-01-01

An assay has been established, based on antibodies against the N-terminal part of the ACTH molecule with a high affinity, a detection limit of 2 pg ACTH when assaying 200 ul unextracted plasma, and implying a total incubation time of three days. The antibody has been obtained by immunizing guinea-pigs with synthetic human 1-24 ACTH coupled to bovine serum albumin. The selected antibody has an equilibrium constant of 4 x 10 11 litres/mole in a final dilution of 1/320.000. The antiserum reacts with synthetic human 1-39 ACTH as well as with synthetic human 1-24 ACTH, and the hormonally inactive synthetic human 11-24 ACTH fragment as well as alpha- and beta-melanocyte-stimulating hormones do not cross-react in the assay. The interassay coefficient of variation of replicate estimates was 11-13%. The reproducibility of the standard curve have been evaluated by calculating the amount of ACTH corresponding to 5% of the (B/T)o value, 1.2+-0.4 pg ACTH/tube+-SD and 50% of (B/T)o value, 15.7+-2.6 pg ACTH/tube+-SD. Validation of the assay has been obtained by assaying samples from patients with verified adrenal disorders, and the accuracy is supported by ACTH determinations in test, where metyrapon had been administered intravenously. A stimulation of ACTH production by insulin-induced hypoglycaemia has been found as well. Special attention is always paid as to the conditions for the blood sampling. A reference interval of 10-76 ng/l has been found (115 normal subjects). (orig.) [de

Processing of thyrotropin-releasing hormone prohormone (pro-TRH) generates a biologically active peptide, prepro-TRH-(160-169), which regulates TRH-induced thyrotropin secretion

International Nuclear Information System (INIS)

Bulant, M.; Vaudry, H.; Roussel, J.P.; Astier, H.; Nicolas, P.

1990-01-01

Rat thyrotropin-releasing hormone (TRH) prohormone contains five copies of the TRH progenitor sequence Gln-His-Pro-Gly linked together by connecting sequences whose biological activity is unknown. Both the predicted connecting peptide prepro-TRH-(160-169) (Ps4) and TRH are predominant storage forms of TRH precursor-related peptides in the hypothalamus. To determine whether Ps4 is co-released with TRH, rat median eminence slices were perfused in vitro. Infusion of depolarizing concentrations of KCl induced stimulation of release of Ps4- and TRH-like immunoreactivity. The possible effect of Ps4 on thyrotropin release was investigated in vitro using quartered anterior pituitaries. Infusion of Ps4 alone had no effect on thyrotropin secretion but potentiated TRH-induced thyrotropin release in a dose-dependent manner. In addition, the occurrence of specific binding sites for 125 I-labeled Tyr-Ps4 in the distal lobe of the pituitary was demonstrated by binding analysis and autoradiographic localization. These findings indicate that these two peptides that arise from a single multifunctional precursor, the TRH prohormone, act in a coordinate manner on the same target cells to promote hormonal secretion. These data suggest that differential processing of the TRH prohormone may have the potential to modulate the biological activity of TRH

Gonadotropin-releasing hormone agonist triggering of oocyte maturation in assisted reproductive technology cycles

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Engin Türkgeldi

2015-06-01

Full Text Available Gonadotropin-releasing hormone agonists (GnRHa have gained increasing attention in the last decade as an alternative trigger for oocyte maturation in patients at high risk for ovarian hyperstimulation syndrome (OHSS. They provide a short luteinizing hormone (LH peak that limits the production of vascular endothelial growth factor, which is the key mediator leading to increased vascular permeability, the hallmark of OHSS. Initial studies showed similar oocyte yield and embryo quality compared with conventional human chorionic gonadotropin (hCG triggering; however, lower pregnancy rates and higher miscarriage rates were alarming in GnRHa triggered groups. Therefore, two approaches have been implemented to rescue the luteal phase in fresh transfers. Intensive luteal phase support (iLPS involves administiration of high doses of progesterone and estrogen and active patient monitoring. iLPS has been shown to provide satisfactory fertilization and clinical pregnancy rates, and to be especially useful in patients with high endogenous LH levels, such as in polycystic ovary syndrome. The other method for luteal phase rescue is low-dose hCG administiration 35 hours after GnRHa trigger. Likewise, this method results in statistically similar ongoing pregnancy rates (although slightly lower than to those of hCG triggered cycles. GnRHa triggering decreased OHSS rates dramatically, however, none of the rescue methods prevent OHSS totally. Cases were reported even in patients who underwent cryopreservation and did not receive hCG. GnRH triggering induces a follicle stimulating hormone (FSH surge, similar to natural cycles. Its possible benefits have been investigated and dual triggering, GnRHa trigger accompanied by a simultaneous low-dose hCG injection, has produced promising results that urge further exploration. Last of all, GnRHa triggering is useful in fertility preservation cycles in patients with hormone sensitive tumors. In conclusion, GnRHa triggering

Effect of thyrotrophin releasing hormone on opiate receptors of the rat brain

Energy Technology Data Exchange (ETDEWEB)

Balashov, A.M.; Shchurin, M.R.

1987-01-01

It has recently been shown that the hypothalamic thyrotropin releasing hormone (TRH) has the properties of a morphine antagonist, blocking its inhibitory action on respiration and, to a lesser degree, its analgesic action. This suggests that the antagonistic effects of TRH are mediated through its interaction with opiate receptors. The aim of this paper is to study this hypothesis experimentally. Tritium-labelled enkephalins in conjunction with scintillation spectroscopy were used to assess the receptor binding behavior. The results indicate the existence of interconnections between the opiate systems and TRH. Although it is too early to reach definite conclusions on the mechanisms of this mutual influence and its physiological significance it can be tentatively suggested that TRH abolishes the pharmacological effects of morphine by modulating the functional state of opiate reception.

Elevation of plasma gonadotropin concentration in response to mammalian gonadotropin releasing hormone (GRH) treatment of the male brown trout as determined by radioimmunoassay

International Nuclear Information System (INIS)

Crim, L.W.; Cluett, D.M.

1974-01-01

Rapid increase of the plasma gonadotropin concentration as measured by radioimmunoassay has been demonstrated in response to GRH treatment of the sexually mature male brown trout. Peak gonadotropin values were observed within 15 minutes of GRH treatment, however, the return to baseline values was prolonged compared with the mammalian response. These data support the concept that the brain, operating via releasing hormones, plays a role in the control of pituitary hormone secretion in fish

Carfilzomib, lenalidomide, and dexamethasone for relapsed multiple myeloma.

Science.gov (United States)

Stewart, A Keith; Rajkumar, S Vincent; Dimopoulos, Meletios A; Masszi, Tamás; Špička, Ivan; Oriol, Albert; Hájek, Roman; Rosiñol, Laura; Siegel, David S; Mihaylov, Georgi G; Goranova-Marinova, Vesselina; Rajnics, Péter; Suvorov, Aleksandr; Niesvizky, Ruben; Jakubowiak, Andrzej J; San-Miguel, Jesus F; Ludwig, Heinz; Wang, Michael; Maisnar, Vladimír; Minarik, Jiri; Bensinger, William I; Mateos, Maria-Victoria; Ben-Yehuda, Dina; Kukreti, Vishal; Zojwalla, Naseem; Tonda, Margaret E; Yang, Xinqun; Xing, Biao; Moreau, Philippe; Palumbo, Antonio

2015-01-08

Lenalidomide plus dexamethasone is a reference treatment for relapsed multiple myeloma. The combination of the proteasome inhibitor carfilzomib with lenalidomide and dexamethasone has shown efficacy in a phase 1 and 2 study in relapsed multiple myeloma. We randomly assigned 792 patients with relapsed multiple myeloma to carfilzomib with lenalidomide and dexamethasone (carfilzomib group) or lenalidomide and dexamethasone alone (control group). The primary end point was progression-free survival. Progression-free survival was significantly improved with carfilzomib (median, 26.3 months, vs. 17.6 months in the control group; hazard ratio for progression or death, 0.69; 95% confidence interval [CI], 0.57 to 0.83; P=0.0001). The median overall survival was not reached in either group at the interim analysis. The Kaplan-Meier 24-month overall survival rates were 73.3% and 65.0% in the carfilzomib and control groups, respectively (hazard ratio for death, 0.79; 95% CI, 0.63 to 0.99; P=0.04). The rates of overall response (partial response or better) were 87.1% and 66.7% in the carfilzomib and control groups, respectively (P<0.001; 31.8% and 9.3% of patients in the respective groups had a complete response or better; 14.1% and 4.3% had a stringent complete response). Adverse events of grade 3 or higher were reported in 83.7% and 80.7% of patients in the carfilzomib and control groups, respectively; 15.3% and 17.7% of patients discontinued treatment owing to adverse events. Patients in the carfilzomib group reported superior health-related quality of life. In patients with relapsed multiple myeloma, the addition of carfilzomib to lenalidomide and dexamethasone resulted in significantly improved progression-free survival at the interim analysis and had a favorable risk-benefit profile. (Funded by Onyx Pharmaceuticals; ClinicalTrials.gov number, NCT01080391.).

Low submetamorphic doses of dexamethasone and thyroxine induce complete metamorphosis in the axolotl (Ambystoma mexicanum) when injected together.

Science.gov (United States)

Kühn, Eduard R; De Groef, Bert; Grommen, Sylvia V H; Van der Geyten, Serge; Darras, Veerle M

2004-06-01

Entanglement of functions between the adrenal (or interrenal) and thyroid axis has been well described for all vertebrates and can be tracked down up to the level of gene expression. Both thyroid hormones and corticosteroids may induce morphological changes leading to metamorphosis climax in the neotenic Mexican axolotl (Ambystoma mexicanum). In a first series of experiments, metamorphosis was induced with an injection of 25 microg T(4) on three alternate days as judged by a decrease in body weight and tail height together with complete gill resorption. This injection also resulted in elevated plasma concentrations of T(3) and corticosterone. Previous results have indicated that the same dose of dexamethasone (DEX) is ineffective in this regard (Gen. Comp. Endocrinol. 127 (2002) 157). In a second series of experiments low doses of T(4) (0.5 microg) or DEX (5 microg) were ineffective to induce morphological changes. However, when these submetamorphic doses were injected together, morphological changes were observed within one week leading to complete metamorphosis. It is concluded that thyroid hormones combined with corticosteroids are essential for metamorphosis in the axolotl and that only high doses of either thyroid hormone or corticosteroid can induce morphological changes when injected separately.

Adverse effects of parenteral dexamethasone in the treatment of pemphigus vulgaris

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Mohammad Jamal Uddin

2016-08-01

Full Text Available Background: Pemphigus vulgaris is associated with high morbidity as well as significant mortality rate. Today the risk of death in pemphigus from the side effect of oral prednisolone is greater than risk of death from the disease itself. Objec­tive: To observe the adverse effects of parenteral dexamethasone compared with oral prednisolone in the treatment of pemphigus vulgaris. Methods: An interventional study was carried out in the department of Dermatology and Venereol­ogy, Bangabandu Sheikh Mujib Medical University, Dhaka, Bangladesh. Total number of patients was thirty and among them fifteen patients were treated with parenteral dexamethasone (Group-A and other fifteen were treated with oral prednisolone (Group-B. Results: The study showed statistically significant differences of skin lesion as well as mucosal lesion of pemphigus after 6 weeks of therapy between of two groups (P<0.05. The most common adverse effects were increased body weight(40%, increased appetite(40%, and puffy face(40% in dexamethasone group. In prednisolone group, these side effects were 60% of the subjects. Other side effects in dexamethasone group were hyperglycemia (33.33%, hypertension (26.66%, and sleep disturbance (13.33%. In prednisolone group, other side effects were hyperglycemia(33.33%, hypertension(40%, gastritis (33.33%, nausea, vomiting (13.33% in each , reactivation of tuberculosis, herpes zoster infection, sleep disturbance, and mood change were 6.66% in each group. Conclusion: In the light of the findings of the study, we conclude that each of the treatment of dexamethasone group and prednisolone group is individually effective and safe in the treatment of pemphigus vulgaris but adverse effects are less in parenteral dexamethasone group than oral prednisolone group. So parenteral dexamethasone can be used as an alternative drug in the treatment of pemphigus vulgaris.

Dexamethasone as adjuvant therapy in the treatment of invasive meningococcal diseases.

Science.gov (United States)

Tolaj, Ilir; Dreshaj, Shemsedin; Qehaja, Emine; Tolaj, Jasmina; Doda-Ejupi, Teuta; Mehmeti, Murat

2010-01-01

With this study we want to evaluate the role of dexamethasone adjuvant treatment in different clinical forms of invasive meningococcal diseases. WORK METHODS: This was a randomized, open label trial that was conducted in 147 individuals with meningococcal sepsis. All of the cases have been divided in two groups: (1) Cases with meningococcal disease and CNS infection, and (2) Cases with meningococcal disease and no affection of the CNS. Cases from both groups were treated with dexamethasone, 0.15 mg/kg, every 6 h, for 4 (four) days, as adjuvant therapy. Cases which were not treated with dexamethasone were used as control group. From overall number of cases, in 130 of them, the meningococcal disease was accompanied with meningitis; in other 17 cases only signs of sepsis were present. In both clinical forms, the dexamethasone was used in 92 cases. The higher mortality rate is registered among the cases without meningitis, 17.65%, compared with 6.92% which is registered among cases with meningitis. The overall mortality rate among all cases was 8.2%. The significant difference was recorded only on CSF sugar level between two groups (treated or not with dexamethasone) on the day 1-4 of the hospitalization. Our epidemiological data are in correlation with data from other epidemiological studies. Most of the cases 69.4%, were more than 12 hours sick at home before the hospitalization, 7.5 % of cases were hospitalized within 12 hours from the onset of the diseases, while 23.1% of cases data are missing. This is in correlation with similar data from other studies. Dexamethasone has a limited effect on outcome of the invasive meningococcal disease. Dexamethasone had some effect only during the days of administration in cases with clinical form of sepsis with meningitis, by normalizing the values of CSF sugar earlier.

Sociality and the telencephalic distribution of corticotrophin-releasing factor, urocortin 3, and binding sites for CRF type 1 and type 2 receptors: A comparative study of eusocial naked mole-rats and solitary Cape mole-rats.

Science.gov (United States)

Coen, Clive W; Kalamatianos, Theodosis; Oosthuizen, Maria K; Poorun, Ravi; Faulkes, Christopher G; Bennett, Nigel C

2015-11-01

Various aspects of social behavior are influenced by the highly conserved corticotrophin-releasing factor (CRF) family of peptides and receptors in the mammalian telencephalon. This study has mapped and compared the telencephalic distribution of the CRF receptors, CRF1 and CRF2 , and two of their ligands, CRF and urocortin 3, respectively, in African mole-rat species with diametrically opposed social behavior. Naked mole-rats live in large eusocial colonies that are characterized by exceptional levels of social cohesion, tolerance, and cooperation in burrowing, foraging, defense, and alloparental care for the offspring of the single reproductive female. Cape mole-rats are solitary; they tolerate conspecifics only fleetingly during the breeding season. The telencephalic sites at which the level of CRF1 binding in naked mole-rats exceeds that in Cape mole-rats include the basolateral amygdaloid nucleus, hippocampal CA3 subfield, and dentate gyrus; in contrast, the level is greater in Cape mole-rats in the shell of the nucleus accumbens and medial habenular nucleus. For CRF2 binding, the sites with a greater level in naked mole-rats include the basolateral amygdaloid nucleus and dentate gyrus, but the septohippocampal nucleus, lateral septal nuclei, amygdalostriatal transition area, bed nucleus of the stria terminalis, and medial habenular nucleus display a greater level in Cape mole-rats. The results are discussed with reference to neuroanatomical and behavioral studies of various species, including monogamous and promiscuous voles. By analogy with findings in those species, we speculate that the abundance of CRF1 binding in the nucleus accumbens of Cape mole-rats reflects their lack of affiliative behavior. © 2015 Wiley Periodicals, Inc.

Intrauterine Zn Deficiency Favors Thyrotropin-Releasing Hormone-Increasing Effects on Thyrotropin Serum Levels and Induces Subclinical Hypothyroidism in Weaned Rats

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Viridiana Alcántara-Alonso

2017-10-01

Full Text Available Individuals who consume a diet deficient in zinc (Zn-deficient develop alterations in hypothalamic-pituitary-thyroid axis function, i.e., a low metabolic rate and cold insensitivity. Although those disturbances are related to primary hypothyroidism, intrauterine or postnatal Zn-deficient adults have an increased thyrotropin (TSH concentration, but unchanged thyroid hormone (TH levels and decreased body weight. This does not support the view that the hypothyroidism develops due to a low Zn intake. In addition, intrauterine or postnatal Zn-deficiency in weaned and adult rats reduces the activity of pyroglutamyl aminopeptidase II (PPII in the medial-basal hypothalamus (MBH. PPII is an enzyme that degrades thyrotropin-releasing hormone (TRH. This hypothalamic peptide stimulates its receptor in adenohypophysis, thereby increasing TSH release. We analyzed whether earlier low TH is responsible for the high TSH levels reported in adults, or if TRH release is enhanced by Zn deficiency at weaning. Dams were fed a 2 ppm Zn-deficient diet in the period from one week prior to gestation and up to three weeks after delivery. We found a high release of hypothalamic TRH, which along with reduced MBH PPII activity, increased TSH levels in Zn-deficient pups independently of changes in TH concentration. We found that primary hypothyroidism did not develop in intrauterine Zn-deficient weaned rats and we confirmed that metal deficiency enhances TSH levels since early-life, favoring subclinical hypothyroidism development which remains into adulthood.

Dexamethasone nanowafer as an effective therapy for dry eye disease.

Science.gov (United States)

Coursey, Terry G; Henriksson, Johanna Tukler; Marcano, Daniela C; Shin, Crystal S; Isenhart, Lucas C; Ahmed, Faheem; De Paiva, Cintia S; Pflugfelder, Stephen C; Acharya, Ghanashyam

2015-09-10

Dry eye disease is a major public health problem that affects millions of people worldwide. It is presently treated with artificial tear and anti-inflammatory eye drops that are generally administered several times a day and may have limited therapeutic efficacy. To improve convenience and efficacy, a dexamethasone (Dex) loaded nanowafer (Dex-NW) has been developed that can release the drug on the ocular surface for a longer duration of time than drops, during which it slowly dissolves. The Dex-NW was fabricated using carboxymethyl cellulose polymer and contains arrays of 500 nm square drug reservoirs filled with Dex. The in vivo efficacy of the Dex-NW was evaluated using an experimental mouse dry eye model. These studies demonstrated that once a day Dex-NW treatment on alternate days during a five-day treatment period was able to restore a healthy ocular surface and corneal barrier function with comparable efficacy to twice a day topically applied dexamethasone eye drop treatment. The Dex-NW was also very effective in down regulating expression of inflammatory cytokines (TNF-α, and IFN-γ), chemokines (CXCL-10 and CCL-5), and MMP-3, that are stimulated by dry eye. Despite less frequent dosing, the Dex-NW has comparable therapeutic efficacy to topically applied Dex eye drops in experimental mouse dry eye model, and these results provide a strong rationale for translation to human clinical trials for dry eye. Copyright © 2015 Elsevier B.V. All rights reserved.

Anti-CD163-dexamethasone conjugate inhibits the acute phase response to lipopolysaccharide in rats

DEFF Research Database (Denmark)

Thomsen, Karen Louise; Møller, Holger Jon; Graversen, Jonas Heilskov

2016-01-01

± 4036 pg/mL, P = 0.03) compared to the low dose dexamethasone. The high dose dexamethasone dose decreased the spleen weight (421 ± 11 mg vs 465 ± 12 mg, P any other group. CONCLUSION: Low-dose anti-CD163-dexamethasone conjugate effectively decreased...

Growth hormone stimulation test - series (image)

Science.gov (United States)

The growth hormone (GH) is a protein hormone released from the anterior pituitary gland under the control of the hypothalamus. In children, GH has growth-promoting effects on the body. It stimulates the ...

Grain dust induces IL-8 production from bronchial epithelial cells: the effect of dexamethasone on IL-8 production.

Science.gov (United States)

Park, H S; Suh, J H; Kim, H Y; Kwon, O J; Choi, D C

1999-04-01

Recent publications have suggested an active participation of neutrophils to induce bronchoconstriction after inhalation of grain dust (GD). To further understand the role of neutrophils in the pathogenesis of GD-induced asthma, this investigation was designed to determine whether human bronchial epithelial cells could produce IL-8 production and to observe the effect of dexamethasone on IL-8 production. We cultured Beas-2B, a bronchial epithelial cell line. To observe GD-induced responses, four concentrations (1 to 200 microg/mL) of GD were incubated for 24 hours and compared with those without incubation of GD. To evaluate the effect of pro-inflammatory cytokines on IL-8 production, epithelial cells were incubated with peripheral blood mononuclear cell (PBMC) culture supernatant, which was derived from the culture of PBMC from a GD-induced asthmatic subject under the exposure to 10 microg/mL of GD, and compared with those cultured without addition of PBMC supernatant. The level of released IL-8 in the supernatant was measured by enzyme-linked immunosorbent assay. To evaluate the effect of dexamethasone on IL-8 production, four concentrations (5 to 5000 ng/mL) of dexamethasone were pre-incubated for 24 hours and the same experiments were repeated. There was significant production of IL-8 from bronchial epithelial cells with additions of GD in a dose-dependent manner (P < .05), which was significantly augmented with additions of PBMC supernatant (P < .05) at each concentration. Compared with the untreated sample, pretreatment of dexamethasone could induced a remarkable inhibitions (15% to 55%) of IL-8 production from bronchial epithelial cells in a dose-dependent manner. These results suggest that IL-8 production from bronchial epithelial cells may contribute to neutrophil recruitment occurring in GD-induced airway inflammation. The downregulation of IL-8 production by dexamethasone from bronchial epithelial cells may contribute to the efficacy of this compound in

Hypothalamic amenorrhea with normal body weight: ACTH, allopregnanolone and cortisol responses to corticotropin-releasing hormone test.

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Meczekalski, B; Tonetti, A; Monteleone, P; Bernardi, F; Luisi, S; Stomati, M; Luisi, M; Petraglia, F; Genazzani, A R

2000-03-01

Hypothalamic amenorrhea (HA) is a functional disorder caused by disturbances in gonadotropin-releasing hormone (GnRH) pulsatility. The mechanism by which stress alters GnRH release is not well known. Recently, the role of corticotropin-releasing hormone (CRH) and neurosteroids in the pathophysiology of HA has been considered. The aim of the present study was to explore further the role of the hypothalamic-pituitary-adrenal axis in HA. We included 8 patients (aged 23.16+/-1.72 years) suffering from hypothalamic stress-related amenorrhea with normal body weight and 8 age-matched healthy controls in the follicular phase of the menstrual cycle. We measured basal serum levels of FSH, LH, and estradiol and evaluated ACTH, allopregnanolone and cortisol responses to CRH test in both HA patients and healthy women. Serum basal levels of FSH, LH, and estradiol as well as basal levels of allopregnanolone were significantly lower in HA patients than in controls (P<0.001) while basal ACTH and cortisol levels were significantly higher in amenorrheic patients with respect to controls (P<0.001). The response (area under the curve) of ACTH, allopregnanolone and cortisol to CRH was significantly lower in amenorrheic women compared with controls (P<0.001, P<0.05, P<0.05 respectively). In conclusion, women with HA, despite the high ACTH and cortisol levels and, therefore, hypothalamus-pituitary-adrenal axis hyperactivity, are characterized by low allopregnanolone basal levels, deriving from an impairment of both adrenal and ovarian synthesis. The blunted ACTH, allopregnanolone and cortisol responses to CRH indicate that, in hypothalamic amenorrhea, there is a reduced sensitivity and expression of CRH receptor. These results open new perspectives on the role of neurosteroids in the pathogenesis of hypothalamic amenorrhea.

Linkage of congenital isolated adrenocorticotropic hormone deficiency to the corticotropin releasing hormone locus using simple sequence repeat polymorphisms

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Kyllo, J.H.; Collins, M.M.; Vetter, K.L. [Univ. of Iowa College of Medicine, Iowa City, IA (United States)] [and others

1996-03-29

Genetic screening techniques using simple sequence repeat polymorphisms were applied to investigate the molecular nature of congenital isolated adrenocorticotropic hormone (ACTH) deficiency. We hypothesize that this rare cause of hypocortisolism shared by a brother and sister with two unaffected sibs and unaffected parents is inherited as an autosomal recessive single gene mutation. Genes involved in the hypothalamic-pituitary axis controlling cortisol sufficiency were investigated for a causal role in this disorder. Southern blotting showed no detectable mutations of the gene encoding pro-opiomelanocortin (POMC), the ACTH precursor. Other candidate genes subsequently considered were those encoding neuroendocrine convertase-1, and neuroendocrine convertase-2 (NEC-1, NEC-2), and corticotropin releasing hormone (CRH). Tests for linkage were performed using polymorphic di- and tetranucleotide simple sequence repeat markers flanking the reported map locations for POMC, NEC-1, NEC-2, and CRH. The chromosomal haplotypes determined by the markers flanking the loci for POMC, NEC-1, and NEC-2 were not compatible with linkage. However, 22 individual markers defining the chromosomal haplotypes flanking CRH were compatible with linkage of the disorder to the immediate area of this gene of chromosome 8. Based on these data, we hypothesize that the ACTH deficiency in this family is due to an abnormality of CRH gene structure or expression. These results illustrate the useful application of high density genetic maps constructed with simple sequence repeat markers for inclusion/exclusion studies of candidate genes in even very small nuclear families segregating for unusual phenotypes. 25 refs., 5 figs., 2 tabs.

The gonadotropin-releasing hormone antagonist protocol--the protocol of choice for the polycystic ovary syndrome patient undergoing controlled ovarian stimulation

DEFF Research Database (Denmark)

Kol, Shahar; Homburg, Roy; Alsbjerg, Birgit

2012-01-01

Polycystic ovary syndrome (PCOS) patients are prone to develop ovarian hyperstimulation syndrome (OHSS), a condition which can be minimized or completely eliminated by the use of a gonadotropin-releasing hormone agonist (GnRHa) trigger. In this commentary paper, we maintain that the gonadotropin-...... ongoing pregnancy rates in the subsequent frozen-thawed transfer cycles....

β-Hydroxy-β-methylbutyrate (HMB normalizes dexamethasone-induced autophagy-lysosomal pathway in skeletal muscle.

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María D Girón

Full Text Available Dexamethasone-induced muscle atrophy is due to an increase in protein breakdown and a decrease in protein synthesis, associated with an over-stimulation of the autophagy-lysosomal pathway. These effects are mediated by alterations in IGF-1 and PI3K/Akt signaling. In this study, we have investigated the effects of β-Hydroxy-β-methylbutyrate (HMB on the regulation of autophagy and proteosomal systems. Rats were treated during 21 days with dexamethasone as a model of muscle atrophy. Co-administration of HMB attenuated the effects promoted by dexamethasone. HMB ameliorated the loss in body weight, lean mass and the reduction of the muscle fiber cross-sectional area (shrinkage in gastrocnemius muscle. Consequently, HMB produced an improvement in muscle strength in the dexamethasone-treated rats. To elucidate the molecular mechanisms responsible for these effects, rat L6 myotubes were used. In these cells, HMB significantly attenuated lysosomal proteolysis induced by dexamethasone by normalizing the changes observed in autophagosome formation, LC3 II, p62 and Bnip3 expression after dexamethasone treatment. HMB effects were mediated by an increase in FoxO3a phosphorylation and concomitant decrease in FoxO transcriptional activity. The HMB effect was due to the restoration of Akt signaling diminished by dexamethasone treatment. Moreover, HMB was also involved in the regulation of the activity of ubiquitin and expression of MurF1 and Atrogin-1, components of the proteasome system that are activated or up-regulated by dexamethasone. In conclusion, in vivo and in vitro studies suggest that HMB exerts protective effects against dexamethasone-induced muscle atrophy by normalizing the Akt/FoxO axis that controls autophagy and ubiquitin proteolysis.

β-Hydroxy-β-methylbutyrate (HMB) normalizes dexamethasone-induced autophagy-lysosomal pathway in skeletal muscle.

Science.gov (United States)

Girón, María D; Vílchez, Jose D; Shreeram, Sathyavageeswaran; Salto, Rafael; Manzano, Manuel; Cabrera, Elena; Campos, Nefertiti; Edens, Neile K; Rueda, Ricardo; López-Pedrosa, Jose M

2015-01-01

Dexamethasone-induced muscle atrophy is due to an increase in protein breakdown and a decrease in protein synthesis, associated with an over-stimulation of the autophagy-lysosomal pathway. These effects are mediated by alterations in IGF-1 and PI3K/Akt signaling. In this study, we have investigated the effects of β-Hydroxy-β-methylbutyrate (HMB) on the regulation of autophagy and proteosomal systems. Rats were treated during 21 days with dexamethasone as a model of muscle atrophy. Co-administration of HMB attenuated the effects promoted by dexamethasone. HMB ameliorated the loss in body weight, lean mass and the reduction of the muscle fiber cross-sectional area (shrinkage) in gastrocnemius muscle. Consequently, HMB produced an improvement in muscle strength in the dexamethasone-treated rats. To elucidate the molecular mechanisms responsible for these effects, rat L6 myotubes were used. In these cells, HMB significantly attenuated lysosomal proteolysis induced by dexamethasone by normalizing the changes observed in autophagosome formation, LC3 II, p62 and Bnip3 expression after dexamethasone treatment. HMB effects were mediated by an increase in FoxO3a phosphorylation and concomitant decrease in FoxO transcriptional activity. The HMB effect was due to the restoration of Akt signaling diminished by dexamethasone treatment. Moreover, HMB was also involved in the regulation of the activity of ubiquitin and expression of MurF1 and Atrogin-1, components of the proteasome system that are activated or up-regulated by dexamethasone. In conclusion, in vivo and in vitro studies suggest that HMB exerts protective effects against dexamethasone-induced muscle atrophy by normalizing the Akt/FoxO axis that controls autophagy and ubiquitin proteolysis.

Variability of Hormonal Stress Markers Collected from a Managed Dolphin Population

Science.gov (United States)

2013-09-30

presence of thyroid stimulating hormone (TSH), which is a peptide hormone produced in the anterior pituitary gland . Thyroid stimulating hormone is 4...releasing hormone (TRH) challenges to characterize the activation of the hypothalamic- pituitary -adrenal (HPA) and hypothalamic- pituitary - thyroid (HPT...triiodothyronine, T3) are released from the thyroid gland and are responsible for regulating the metabolism of an animal and affect the activity of other stress

Mechanisms of dexamethasone-induced disturbed sleep and fatigue in paediatric patients receiving treatment for ALL.

Science.gov (United States)

Vallance, Kelly; Liu, Wei; Mandrell, Belinda N; Panetta, John C; Gattuso, Jami S; Hockenberry, Marilyn; Zupanec, Sue; Yang, Lei; Yang, Jie; Hinds, Pamela S

2010-07-01

Dexamethasone contributes to high cure rates in paediatric acute lymphoblastic leukaemia (ALL) but significantly and adversely alters sleep and fatigue. Herein we explored three mechanisms (pharmacokinetics, serum albumin and pharmacogenetics) through which dexamethasone may cause debilitating fatigue and disrupted sleep. We enrolled 100 patients on a 10-d study: 5-d of no dexamethasone (OFF DEX) followed by 5-d of dexamethasone (ON DEX) during continuation chemotherapy. Sleep variables were collected with continuous actigraphy on days 1 through 5, both OFF DEX and ON DEX. On days 2 and 5 of each 5-d period, parents and patients 7 years of age and older completed a sleep diary and Fatigue Scale questionnaire. Blood was collected at 0 (pre-dexamethasone), 1, 2, 4 and 8 h after the first oral dexamethasone dose for pharmacokinetic analysis. Serum albumin concentration was retrospectively analysed in stored samples. Patient DNA was genotyped for 99 polymorphic loci in candidate genes associated with glucocorticoid metabolism. Dexamethasone clearance was significantly greater in younger patients than in older ones and in lower risk patients. In multiple regression models, risk group was significantly related to pharmacokinetic parameters. We found that polymorphisms in three genes (AHSG, IL6, POLDIP3) were significantly associated with sleep measures but not with fatigue. Risk group had the most significant relationship with disrupted sleep in patients while on dexamethasone. Serum albumin levels had neither a direct relationship with sleep or fatigue variables nor an indirect relationship through systemic exposure to dexamethasone. We identified candidate genes that may help explain the adverse events of disrupted sleep in paediatric patients receiving dexamethasone. Copyright 2010 Elsevier Ltd. All rights reserved.

Influence of gonadotropin-releasing hormone and timing of insemination relative to estrus on pregnancy rates of dairy cattle at first service.

Science.gov (United States)

Mee, M O; Stevenson, J S; Scoby, R K; Folman, Y

1990-06-01

The objective was to determine the influence of gonadotropin-releasing hormone on pregnancy rates of dairy cattle at first services, when both the timing of hormone injection and insemination were altered relative to the onset of estrus. Cows (n = 325) were assigned randomly to six groups making up a 2 X 2 X 2 incomplete factorial experiment; dose of GnRH (100 micrograms versus saline), timing [1 h (early) or 12 to 16 h (late) after first detected estrus] of AI, and timing of hormone injection (early versus late) were the three main effects. Cows were observed for estrus 4 times daily. Treatments and resulting pregnancy rates were: 1) hormone injection early plus AI early (35%), 2) hormone injection late plus AI early (34%), 3) saline injection early plus AI early (30%), 4) hormone injection late plus AI late (30%), 5) hormone injection early plus AI late (46%), and 6) saline injection late plus AI late (43%). Pregnancy rate in the first four groups (32%) was less than that in the latter two groups (44%). Concentrations of LH in serum were greater for cows given hormone or saline injections in early estrus than for cows injected with either hormone of saline during late estrus. Concentrations of LH in serum 2 h after GnRH were elevated above those of controls, whether GnRH was injected during early or late estrus. Neither concentrations of LH during estrus nor concentrations of progesterone 8 to 14 d after estrus explained the possible antifertility effect of GnRH given during late estrus.(ABSTRACT TRUNCATED AT 250 WORDS)

[Role of the Periaqueductal Gray Matter of the Midbrain in Regulation of Somatic Pain Sensitivity During Stress: Participation of Corticotropin-Releasing Factor and Glucocorticoid Hormones].

Science.gov (United States)

Yarushkina, N I; Filaretova, L P

2015-01-01

Periaqueductal gray matter of the midbrain (PAGM) plays a crucial role in the regulation of pain sensitivity under stress, involving in the stress-induced analgesia. A key hormonal system of adaptation under stress is the hypothalamic-pituitary-adrenocortical (HPA) axis. HPA axis's hormones, corticotropin-releasing factor (CRF) and glucocorticoids, are involved in stress-induced analgesia. Exogenous hormones of the HPA axis, similarly to the hormones produced under stress, may cause an analgesic effect. CRF-induced analgesia may be provided by glucocorticoid hormones. CRF and glucocorticoids-induced effects on somatic pain sensitivity may be mediated by PAGM. The aim of the review was to analyze the data of literature on the role of PAGM in the regulation of somatic pain sensitivity under stress and in providing of CRF and glucocorticoid-induced analgesia.

Prenatal exposure to vinclozolin disrupts selective aspects of the gonadotropin-releasing hormone neuronal system of the rabbit

OpenAIRE

Wadas, B.C.; Hartshorn, C.A.; Aurand, E.R.; Palmer, J.S.; Roselli, C.E.; Noel, M.L.; Gore, A.C.; Veeramachaneni, D.N.R.; Tobet, S.A.

2010-01-01

Developmental exposure to the agricultural fungicide vinclozolin can impair reproductive function in male rabbits and was previously found to decrease the number of immunoreactive-gonadotropin-releasing hormone (ir-GnRH) neurons in the region of the organum vasculosum of the lamina terminalis (OVLT) and rostral preoptic area (rPOA) by postnatal week (PNW) 6. To further examine the disruption of GnRH neurons by fetal vinclozolin exposure, in the current study, pregnant rabbits were dosed orall...

The effect of single low-dose dexamethasone on vomiting during awake craniotomy.

Science.gov (United States)

Kamata, Kotoe; Morioka, Nobutada; Maruyama, Takashi; Komayama, Noriaki; Nitta, Masayuki; Muragaki, Yoshihiro; Kawamata, Takakazu; Ozaki, Makoto

2016-12-01

Intraoperative vomiting leads to serious respiratory complications that could influence the surgical decision-making process for awake craniotomy. However, the use of antiemetics is still limited in Japan. The aim of this study was to investigate the effect of prophylactically administered single low-dose dexamethasone on the incidence of vomiting during awake craniotomy. The frequency of hyperglycemia was also examined. We conducted a retrospective case review of awake craniotomy for glioma resection between 2012 and 2015. Of the 124 patients, 91 were included in the analysis. Dexamethasone was not used in 43 patients and the 48 remaining patients received an intravenous bolus of 4.95 mg dexamethasone at anesthetic induction. Because of stable operating conditions, no one required conscious sedation throughout functional mapping and tumor resection. Although dexamethasone pretreatment reduced the incidence of intraoperative vomiting (P = 0.027), the number of patients who complained of nausea was comparable (P = 0.969). No adverse events related to vomiting occurred intraoperatively. Baseline blood glucose concentration did not differ between each group (P = 0.143), but the samples withdrawn before emergence (P = 0.018), during the awake period (P awake craniotomy cases. However, as even a small dose of dexamethasone increases the risk for hyperglycemia, antiemetic prophylaxis with dexamethasone should be administered after careful consideration. Monitoring of perioperative blood glucose concentration is also necessary.

Neurotrophins and their receptors in the rat pituitary gland: regulation of BDNF and trkB mRNA levels by adrenal hormones.

Science.gov (United States)

Kononen, J; Soinila, S; Persson, H; Honkaniemi, J; Hökfelt, T; Pelto-Huikko, M

1994-12-01

We studied the expression of messenger ribonucleic acids (mRNAs) for neurotrophins and neurotrophin receptors in the rat pituitary gland and examined the influence of adrenal hormones on their mRNA levels, using in situ hybridization and Northern blot analysis. The only neurotrophin present at detectable levels in the pituitary was brain-derived neurotrophic factor (BDNF), which was observed in the anterior and intermediate lobes. Several transcripts of the putative receptor for BDNF, trkB, were present in the anterior and posterior lobes of the pituitary. A low amount of trkC mRNA was found in both the anterior and the intermediate lobe. Dexamethasone treatment decreased both BDNF and trkB mRNA levels in the anterior lobe of the pituitary. Adrenalectomy had no effect on trkB expression, but it decreased BDNF mRNA levels in comparison to the control animals. This effect could not be reversed by dexamethasone substitution, suggesting that BDNF, mRNA levels may be regulated not only by glucocorticoids but also by other adrenal hormones. These results demonstrate that BDNF, trkB and trkC are expressed in the pituitary gland and that glucocorticoids and possibly other adrenal hormones may modulate pituitary functions by regulating the expression of neurotrophic factors and their receptors. Whether BDNF acts as a secreted hormone, a trophic factor, or has autocrine/paracrine functions within the pituitary through its receptor, trkB, remains to be studied.

Intravitreal clindamycin and dexamethasone for toxoplasmic retinochoroiditis.

Science.gov (United States)

Kishore, K; Conway, M D; Peyman, G A

2001-01-01

To present a new method for the management of toxoplasmic retinochoroiditis (TRC). The patients were females ranging in age from 10 to 61 years (average 26.5). Four eyes of 4 patients were treated with intravitreal injections of 1.0 mg clindamycin in 0.1 mL and 1.0 mg of dexamethasone in 0.1 mL. The injections were given under general or peribulbar anesthesia. Three patients continued one systemic drug. Follow-up ranged from 11 to 26 months (mean 17.5). A favorable response was noted in each eye within two weeks after the intravitreal injections. All patients required 2 to 4 intravitreal injections in the affected eye for the control of TRC. Visual acuity improved in each eye. The disc and macula were preserved in all eyes. Recurrence was noted in one case, which responded to a repeated intravitreal injection of clindamycin and dexamethasone. Intravitreal injections of clindamycin and dexamethasone are well tolerated and may offer an additional strategy to treat TRC in patients who are unable to afford or tolerate systemic therapy, or whose disease progresses despite systemic therapy.

Development and Evaluation of a Novel Microemulsion of Dexamethasone and Tobramycin for Topical Ocular Administration.

Science.gov (United States)

Bachu, Rinda Devi; Stepanski, Marina; Alzhrani, Rami M; Jung, Rose; Boddu, Sai H S

2018-05-01

The purpose of this study was to develop and evaluate a novel dexamethasone- and tobramycin-loaded microemulsion for its potential for treating anterior segment eye infections. The microemulsion was evaluated for pH, particle size, zeta potential, light transmittance, morphology, and in vitro drug release. Sterility of the microemulsion was evaluated by direct as well as plate inoculation methods. Anti-inflammatory activity of dexamethasone, bactericidal activity of tobramycin, and cytotoxicity of the microemulsion were assessed and compared to that of the marketed eye drop suspension (Tobradex ® ). Histological evaluation was performed in bovine corneas to assess the safety of microemulsion in comparison to Tobradex suspension. In addition, the stability of the microemulsion was studied at 4°C, 25°C, and 40°C. The pH of the microemulsion was close to the pH of tear fluid. The microemulsion displayed an average globule size under 20 nm, with light transmittance around 95%-100%. The aseptically prepared microemulsion remained sterile for up to 14 days. The cytotoxicity of the microemulsion in bovine corneal endothelial cells was comparable to that of the Tobradex suspension. The anti-inflammatory activity of dexamethasone and the antibacterial activity of tobramycin from the microemulsion were significantly higher than those of the Tobradex suspension (P microemulsion was found to be stable at 4°C and 25°C for 3 months. In conclusion, the developed microemulsion could be explored as a suitable alternative to the marketed suspension for treating anterior segment eye infections.

Antenatal dexamethasone after asphyxia increases neural injury in preterm fetal sheep.

Directory of Open Access Journals (Sweden)

Miriam E Koome

Full Text Available BACKGROUND AND PURPOSE: Maternal glucocorticoid treatment for threatened premature delivery dramatically improves neonatal survival and short-term morbidity; however, its effects on neurodevelopmental outcome are variable. We investigated the effect of maternal glucocorticoid exposure after acute asphyxia on injury in the preterm brain. METHODS: Chronically instrumented singleton fetal sheep at 0.7 of gestation received asphyxia induced by complete umbilical cord occlusion for 25 minutes. 15 minutes after release of occlusion, ewes received a 3 ml i.m. injection of either dexamethasone (12 mg, n = 10 or saline (n = 10. Sheep were killed after 7 days recovery; survival of neurons in the hippocampus and basal ganglia, and oligodendrocytes in periventricular white matter were assessed using an unbiased stereological approach. RESULTS: Maternal dexamethasone after asphyxia was associated with more severe loss of neurons in the hippocampus (CA3 regions, 290 ± 76 vs 484 ± 98 neurons/mm(2, mean ± SEM, P<0.05 and basal ganglia (putamen, 538 ± 112 vs 814 ± 34 neurons/mm(2, P<0.05 compared to asphyxia-saline, and with greater loss of both total (913 ± 77 vs 1201 ± 75/mm(2, P<0.05 and immature/mature myelinating oligodendrocytes in periventricular white matter (66 ± 8 vs 114 ± 12/mm(2, P<0.05, vs sham controls 165 ± 10/mm(2, P<0.001. This was associated with transient hyperglycemia (peak 3.5 ± 0.2 vs. 1.4 ± 0.2 mmol/L at 6 h, P<0.05 and reduced suppression of EEG power in the first 24 h after occlusion (maximum -1.5 ± 1.2 dB vs. -5.0 ± 1.4 dB in saline controls, P<0.01, but later onset and fewer overt seizures. CONCLUSIONS: In preterm fetal sheep, exposure to maternal dexamethasone during recovery from asphyxia exacerbated brain damage.

Preoperative dexamethasone reduces acute but not sustained pain after lumbar disk surgery

DEFF Research Database (Denmark)

Nielsen, Rikke V; Siegel, Hanna; Fomsgaard, Jonna S

2015-01-01

on acute and sustained pain after lumbar disk surgery. In this blinded study, 160 patients undergoing lumbar disk surgery were randomly assigned to 16 mg IV dexamethasone or placebo. All patients received perioperative paracetamol and ibuprofen, and postoperative IV patient-controlled analgesia...... months postoperatively. Acute pain during mobilization (weighted average area under the curve, 2-24 hours) was significantly reduced in the dexamethasone group: 33 (22) mm vs placebo 43 (18) mm, (95% confidence interval [CI] 3-16) P = 0.005. Vomiting 0 to 24 hours postoperatively was reduced....../paralysis of the legs in the dexamethasone and placebo groups, respectively, 3 months postoperatively (P = 0.20). In conclusion, preoperative dexamethasone significantly reduced pain during mobilization and vomiting, after lumbar disk surgery. No significant effects were observed 3 months postoperatively....

Hormone and enzyme determination as influenced by corticoids and tocolytics in the final stage of pregnancy

International Nuclear Information System (INIS)

Kaminsky, G.; Kayser, I.B.

1981-01-01

In order to prevent membrane syndrome, the synthetic corticoids betamethasone, dexamethasone and 16-methylene prednisolone combined with tokolytic substances. The hormones ACTH, cortisol, oestriol, and the enzyme renine have been investigated by RIA in order to find out whether the various corticoids cause different changes in the endocrinous parameters of mother and foetus. A suppression of the four measured parameters was found in the presence of corticoids. (orig./MG) [de

Rituximab and Dexamethasone vs Dexamethasone Monotherapy in Newly Diagnosed Patients with Primary Immune Thrombocytopenia

DEFF Research Database (Denmark)

Gudbrandsdottir, Sif; Birgens, Henrik Sverre; Frederiksen, Henrik

2013-01-01

In this study, we report the results from the largest cohort to date of newly diagnosed adult immune thrombocytopenia patients randomized to treatment with dexamethasone alone or in combination with rituximab. Eligible were patients with platelet counts ≤25×10(9)/L or ≤50×10(9)/L with bleeding sy...

Regulation of feeding behavior and psychomotor activity by corticotropin-releasing hormone (CRH in fish

Directory of Open Access Journals (Sweden)

Kouhei eMatsuda

2013-05-01

Full Text Available Corticotropin-releasing hormone (CRH is a hypothalamic neuropeptide belonging to a family of neuropeptides that includes urocortins, urotensin I and sauvagine in vertebrates. CRH and urocortin act as anorexigenic factors for satiety regulation in fish. In a goldfish model, intracerebroventricular (ICV administration of CRH has been shown to affect not only food intake, but also locomotor and psychomotor activities. In particular, CRH elicits anxiety-like behavior as an anxiogenic neuropeptide in goldfish, as is the case in rodents. This paper reviews current knowledge of CRH and its related peptides derived from studies of teleost fish, as representative non-mammals, focusing particularly on the role of the CRH system, and examines its significance from a comparative viewpoint.

Gastrointestinal hormone research - with a Scandinavian annotation

DEFF Research Database (Denmark)

Rehfeld, Jens F

2015-01-01

Gastrointestinal hormones are peptides released from neuroendocrine cells in the digestive tract. More than 30 hormone genes are currently known to be expressed in the gut, which makes it the largest hormone-producing organ in the body. Modern biology makes it feasible to conceive the hormones...... as a blood-borne hormone, a neurotransmitter, a local growth factor or a fertility factor. The targets of gastrointestinal hormones are specific G-protein-coupled receptors that are expressed in the cell membranes also outside the digestive tract. Thus, gut hormones not only regulate digestive functions...

Sexual dimorphism of gonadotropin-releasing hormone type-III (GnRH3) neurons and hormonal sex reversal of male reproductive behavior in Mozambique tilapia.

Science.gov (United States)

Kuramochi, Asami; Tsutiya, Atsuhiro; Kaneko, Toyoji; Ohtani-Kaneko, Ritsuko

2011-10-01

In tilapia, hormone treatment during the period of sexual differentiation can alter the phenotype of the gonads, indicating that endocrine factors can cause gonadal sex reversal. However, the endocrine mechanism underlying sex reversal of reproductive behaviors remains unsolved. In the present study, we detected sexual dimorphism of gonadotropin-releasing hormone type III (GnRH3) neurons in Mozambique tilapia Oreochromis mossambicus. Our immunohistochemical observations showed sex differences in the number of GnRH3 immunoreactive neurons in mature tilapia; males had a greater number of GnRH3 neurons in the terminal ganglion than females. Treatment with androgen (11-ketotestosterone (11-KT) or methyltestosterone), but not that with 17β-estradiol, increased the number of GnRH3 neurons in females to a level similar to that in males. Furthermore, male-specific nest-building behavior was induced in 70% of females treated with 11-KT within two weeks after the onset of the treatment. These results indicate androgen-dependent regulation of GnRH3 neurons and nest-building behavior, suggesting that GnRH3 is importantly involved in sex reversal of male-specific reproductive behavior.

Impact of prior treatment and depth of response on survival in MM-003, a randomized phase 3 study comparing pomalidomide plus low-dose dexamethasone versus high-dose dexamethasone in relapsed/refractory multiple myeloma

Science.gov (United States)

San Miguel, Jesus F.; Weisel, Katja C.; Song, Kevin W.; Delforge, Michel; Karlin, Lionel; Goldschmidt, Hartmut; Moreau, Philippe; Banos, Anne; Oriol, Albert; Garderet, Laurent; Cavo, Michele; Ivanova, Valentina; Alegre, Adrian; Martinez-Lopez, Joaquin; Chen, Christine; Renner, Christoph; Bahlis, Nizar Jacques; Yu, Xin; Teasdale, Terri; Sternas, Lars; Jacques, Christian; Zaki, Mohamed H.; Dimopoulos, Meletios A.

2015-01-01

Pomalidomide is a distinct oral IMiD® immunomodulatory agent with direct antimyeloma, stromal-support inhibitory, and immunomodulatory effects. The pivotal, multicenter, open-label, randomized phase 3 trial MM-003 compared pomalidomide + low-dose dexamethasone vs high-dose dexamethasone in 455 patients with refractory or relapsed and refractory multiple myeloma after failure of bortezomib and lenalidomide treatment. Initial results demonstrated significantly longer progression-free survival and overall survival with an acceptable tolerability profile for pomalidomide + low-dose dexamethasone vs high-dose dexamethasone. This secondary analysis describes patient outcomes by treatment history and depth of response. Pomalidomide + low-dose dexamethasone significantly prolonged progression-free survival and favored overall survival vs high-dose dexamethasone for all subgroups analyzed, regardless of prior treatments or refractory status. Both univariate and multivariate analyses showed that no variable relating to either the number (≤ or > 3) or type of prior treatment was a significant predictor of progression-free survival or overall survival. No cross-resistance with prior lenalidomide or thalidomide treatment was observed. Patients achieving a minimal response or better to pomalidomide + low-dose dexamethasone treatment experienced a survival benefit, which was even higher in those achieving at least a partial response (17.2 and 19.9 months, respectively, as compared with 7.5 months for patients with less than minimal response). These data suggest that pomalidomide + low-dose dexamethasone should be considered a standard of care in patients with refractory or relapsed and refractory multiple myeloma regardless of prior treatment. ClinicalTrials.gov: NCT01311687; EudraCT: 2010-019820-30. PMID:26160879

Total Androgen Blockade Versus a Luteinizing Hormone-Releasing Hormone Agonist Alone in Men With High-Risk Prostate Cancer Treated With Radiotherapy

International Nuclear Information System (INIS)

Nanda, Akash; Chen, M.-H.; Moran, Brian J.; Braccioforte, Michelle H.; Dosoretz, Daniel; Salenius, Sharon; Katin, Michael; Ross, Rudi; D'Amico, Anthony V.

2010-01-01

Purpose: To assess whether short-course total androgen blockade vs. a luteinizing hormone-releasing hormone (LHRH) agonist alone affects the risk of prostate cancer-specific mortality (PCSM) in men with localized but high-risk disease treated with radiotherapy. Methods and Materials: The study cohort comprised 628 men with T1-T4, N0, M0 prostate cancer with high-risk disease (prostate-specific antigen level >20 ng/mL, Gleason score ≥8, or clinical category ≥T3) treated with 45 Gy of external beam radiotherapy followed by a brachytherapy boost in addition to receiving a median of 4.3 (interquartile range [IQR], 3.6-6.4) months of hormonal blockade with an LHRH agonist plus an antiandrogen or monotherapy with an LHRH agonist. Fine and Gray's multivariable regression analysis was used to determine whether combination androgen suppression therapy (AST) vs. monotherapy affected the risk of PCSM, adjusting for treatment year, duration of AST, age, and known prognostic factors. Results: After a median follow-up of 4.9 (IQR, 3.5-6.5) years, men receiving combination AST had a lower risk of PCSM than those treated with monotherapy (adjusted hazard ratio [AHR], 0.18; 95% confidence interval [CI], 0.04-0.90; p = 0.04). An increasing prostate-specific antigen level (AHR, 2.70; 95% CI, 1.64-4.45; p < 0.001) and clinical category T3/4 disease (AHR, 29.6; 95% CI, 2.88-303.5; p = 0.004) were also associated with an increased risk of PCSM. Conclusions: In men with localized but high-risk prostate cancer treated with external beam radiotherapy and brachytherapy, short-course AST with an LHRH agonist plus an antiandrogen is associated with a decreased risk of PCSM when compared with monotherapy with an LHRH agonist.

Antiproliferative effect of growth hormone-releasing hormone (GHRH antagonist on ovarian cancer cells through the EGFR-Akt pathway

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Varga Jozsef

2010-05-01

Full Text Available Abstract Background Antagonists of growth hormone-releasing hormone (GHRH are being developed for the treatment of various human cancers. Methods MTT assay was used to test the proliferation of SKOV3 and CaOV3. The splice variant expression of GHRH receptors was examined by RT-PCR. The expression of protein in signal pathway was examined by Western blotting. siRNA was used to block the effect of EGFR. Results In this study, we investigated the effects of a new GHRH antagonist JMR-132, in ovarian cancer cell lines SKOV3 and CaOV3 expressing splice variant (SV1 of GHRH receptors. MTT assay showed that JMR-132 had strong antiproliferative effects on SKOV3 and CaOV3 cells in both a time-dependent and dose-dependent fashion. JMR-132 also induced the activation and increased cleaved caspase3 in a time- and dose-dependent manner in both cell lines. In addition, JMR-132 treatments decreased significantly the epidermal growth factor receptor (EGFR level and the phosphorylation of Akt (p-Akt, suggesting that JMR-132 inhibits the EGFR-Akt pathway in ovarian cancer cells. More importantly, treatment of SKOV3 and CaOV3 cells with 100 nM JMR-132 attenuated proliferation and the antiapoptotic effect induced by EGF in both cell lines. After the knockdown of the expression of EGFR by siRNA, the antiproliferative effect of JMR-132 was abolished in SKOV3 and CaOV3 cells. Conclusions The present study demonstrates that the inhibitory effect of the GHRH antagonist JMR-132 on proliferation is due, in part, to an interference with the EGFR-Akt pathway in ovarian cancer cells.

Low-dose dexamethasone during arthroplasty: What do we know about the risks?

NARCIS (Netherlands)

Wegener, Jessica T.; Kraal, Tim; Stevens, Markus F.; Hollmann, Markus W.; Kerkhoffs, Gino M. M. J.; Haverkamp, Daniël

2016-01-01

Dexamethasone is commonly applied during arthroplasty to control post-operative nausea and vomiting (PONV). However, conflicting views of orthopaedic surgeons and anaesthesiologists regarding the use of dexamethasone raise questions about risks of impaired wound healing and surgical site infections

Diagnostic challenges and management of a patient with acromegaly due to ectopic growth hormone-releasing hormone secretion from a bronchial carcinoid tumour

Directory of Open Access Journals (Sweden)

Nikolaos Kyriakakis

2017-01-01

Full Text Available A male patient presented at the age of 30 with classic clinical features of acromegaly and was found to have elevated growth hormone levels, not suppressing during an oral glucose tolerance test. His acromegaly was originally considered to be of pituitary origin, based on a CT scan, which was interpreted as showing a pituitary macroadenoma. Despite two trans-sphenoidal surgeries, cranial radiotherapy and periods of treatment with bromocriptine and octreotide, his acromegaly remained active clinically and biochemically. A lung mass was discovered incidentally on a chest X-ray performed as part of a routine pre-assessment for spinal surgery 5 years following the initial presentation. This was confirmed to be a bronchial carcinoid tumour, which was strongly positive for growth hormone-releasing hormone (GHRH and somatostatin receptor type 2 by immunohistochemistry. The re-examination of the pituitary specimens asserted the diagnosis of pituitary GH hyperplasia. Complete resolution of the patient’s acromegaly was achieved following right lower and middle lobectomy. Seventeen years following the successful resection of the bronchial carcinoid tumour the patient remains under annual endocrine follow-up for monitoring of the hypopituitarism he developed after the original interventions to his pituitary gland, while there has been no evidence of active acromegaly or recurrence of the carcinoid tumour. Ectopic acromegaly is extremely rare, accounting for <1% of all cases of acromegaly. Our case highlights the diagnostic challenges differentiating between ectopic acromegaly and acromegaly of pituitary origin and emphasises the importance of avoiding unnecessary pituitary surgery and radiotherapy. The role of laboratory investigations, imaging and histology as diagnostic tools is discussed.

Evaluation of the responsiveness of pituitary gland to thyrotropin releasing hormone (TRH) in rats in the period of 8:00 to 12:00 a.m

International Nuclear Information System (INIS)

Borghi, V.C.; Nicolau, W.; Bojarczuk, C.; Pieroni, R.R.

1977-01-01

The functional pituitary capacity for the secretion thyrotropin in rats, in relation to the period of time 8:00-12:00 a.m. was studied by means of the administration of synthetic TRH (thyrotropin releasing hormone). The highest pituitary response to the hypothalamic hormone attains its peak between 9:50 and 10:30 a.m., a time in which the gland denotes a high and practically constant level of TSH secretion [pt

Does Dexamethasone Helps in Meningococcal Sepsis?

Science.gov (United States)

Tolaj, Ilir; Ramadani, Hamdi; Mehmeti, Murat; Gashi, Hatixhe; Kasumi, Arbana; Gashi, Visar; Jashari, Haki

2017-06-01

Prompt recognition and aggressive early treatment are the only effective measures against invasive meningococcal disease (IMD). Anti-inflammatory adjunctive treatment remains controversial and difficult to assess in patients with IMD. The purpose of this study was to evaluate the effect of dexamethasone (DXM) as adjunctive treatment in different clinical forms of IMD, and attempt to answer if DXM should be routinely used in the treatment of IMD. In this non-interventional clinical study (NIS), 39 patients with meningococcal septicaemia with or without of meningitis were included, and compared regarding the impact of dexamethasone (DXM), as an adjunctive treatment, on the outcome of IMD. SPSS statistics is used for statistical processing of data. Thirty (76.9%) patients with IMD had sepsis and meningitis, and 9 (23.1%) of them had sepsis alone. Dexamethasone was used in 24 (61.5%) cases, in both clinical groups. The overall mortality rate was 10.3%. Pneumonia was diagnosed in 6 patients (15.4%), arthritis in 3 of them (7.7%), and subdural effusion in one patient (2.6%). The data showed a significant statistical difference on the length of hospitalization, and WBC normalization in groups of patients treated with DXM. The use of DXM as adjunctive therapy in invasive meningococcal disease has a degree of proven benefits and no harmful effects. In fighting this very dangerous and complex infection, even a limited benefit is sufficient to recommend the use of DXM as adjunctive treatment in invasive meningococcal disease.

Combinatorial release of dexamethasone and amiodarone from a nano-structured parylene-C film to reduce perioperative inflammation and atrial fibrillation

Science.gov (United States)

Robinson, Erik; Kaushal, Sunjay; Alaboson, Justice; Sharma, Sudhish; Belagodu, Amogh; Watkins, Claire; Walker, Brandon; Webster, Gregory; McCarthy, Patrick; Ho, Dean

2016-02-01

Suppressing perioperative inflammation and post-operative atrial fibrillation requires effective drug delivery platforms (DDP). Localized anti-inflammatory and anti-arrhythmic agent release may be more effective than intravenous treatment to improve patient outcomes. This study utilized a dexamethasone (DEX) and amiodarone (AMIO)-loaded Parylene-C (PPX) nano-structured film to inhibit inflammation and atrial fibrillation. The PPX film was tested in an established pericardial adhesion rabbit model. Following sternotomy, the anterior pericardium was resected and the epicardium was abraded. Rabbits were randomly assigned to five treatment groups: control, oxidized PPX (PPX-Oxd), PPX-Oxd infused with DEX (PPX-Oxd[DEX]), native PPX (PPX), and PPX infused with DEX and AMIO (PPX[AMIO, DEX]). 4 weeks post-sternotomy, pericardial adhesions were evaluated for gross adhesions using a 4-point grading system and histological evaluation for epicardial neotissue fibrosis (NTF). Atrial fibrillation duration and time per induction were measured. The PPX[AMIO, DEX] group had a significant reduction in mean adhesion score compared with the control group (control 2.75 +/- 0.42 vs. PPX[AMIO, DEX] 0.25 +/- 0.42, P atrial fibrillation was decreased in rabbits with PPX[AMIO, DEX] films compared to control (9.5 +/- 6.8 s vs. 187.6 +/- 174.7 s, p = 0.003). Time of atrial fibrillation per successful induction decreased among PPX[AMIO, DEX] films compared to control (2.8 +/- 1.2 s vs. 103.2 +/- 178 s, p = 0.004). DEX/AMIO-loaded PPX films are associated with reduced perioperative inflammation and a diminished atrial fibrillation duration. Epicardial application of AMIO, DEX films is a promising strategy to prevent post-operative cardiac complications.Suppressing perioperative inflammation and post-operative atrial fibrillation requires effective drug delivery platforms (DDP). Localized anti-inflammatory and anti-arrhythmic agent release may be more effective than intravenous treatment to

Luteinizing hormone-releasing hormone inactivation by purified pituitary plasma membranes: effects of receptor-binding studies.

Science.gov (United States)

Clayton, R N; Shakespear, R A; Duncan, J A; Marshall, J C

1979-05-01

Inactivation of LHRH by purified bovine pituitary plasma membranes was studied in vitro. After incubation of [125I]iodo-LHRH with plasma membranes, the amount of tracer bound to the pellet was measured, and the integrity of the unbound tracer in the supernatant was assessed. Reduction in ability to bind to anti-LHRH serum and to rebind to plasma membranes together with altered electrophoretic mobility on polyacrylamide gels showed that the unbound [125I]iodo-LHRH was inactivated. LHRH inactivation occurred rapidly and was dependent upon membrane concentration and incubation temperature. These results indicate that hormone inactivation must be taken into account in the interpretation of LHRH-receptor interactions. During 37 C incubations, the apparent absence of specific LHRH binding can be explained by inactivation of tracer hormone. Significant LHRH inactivation also occurred at 0 C, which in part explains the insensitivity of LHRH receptor assays. Assessment of LHRH inactivation by different particulate subcellular fractions of pituitary tissue showed that the inactivating enzyme was associated with the plasma membranes; other organelles did not alter LHRH. The enzyme appeared to be an integral part of the plasma membrane structure, since enzymic activity could not be removed by washing without reducing specific LHRH binding. Additionally, reduction of LHRH inactivation by the inhibitors Bacitracin and Trasylol and by magnesium was also accompanied by reduced LHRH binding. Previous studies have shown that the majority of LHRH binding to pituitary plasma membranes is to the low affinity site (approximately 10(-6) M), but the significance of this binding has been uncertain. Our findings indicate that low affinity binding probably represents binding of LHRH to the inactivating enzyme. The LHRH analog, D-Ser6(TBu), des Gly10, ethylamide, has greater biological activity than LHRH and is not inactivated to a significant extent by pituitary plasma membranes. The

Comparison the Effect of Granisetron and Dexamethasone on Intravenous Propofol Pain.

Science.gov (United States)

Adinehmehr, Leili; Salimi, Sohrab; Sane, Shahryar; Sina, Venous; Najafizadeh, Rana

2018-01-01

The incidence of propofol injection pain during induction of general anesthesia varies from 28% to 90%. This prospective, randomized, double-blind, placebo-controlled study evaluated the effect of dexamethasone and granisetron for reducing the incidence and severity of propofol injection pain. A total of 227 female subjects received 5 mL of preservative-free saline, 1 mg granisetron (5 ml), or 0.15 mg/kg of dexamethasone (5 ml), intravenously, following exsanguination and occlusion of the veins of the arm. This was followed by a 0.5 mg/kg injection of propofol. Pain scores and intensity of pain recorded immediately following the injection of propofol. Hemodynamic parameters and O 2 sat were recorded 1, 3, 5, and 10 min after propofol injection. The incidence pain following the injection of propofol was significantly decreased with both granisetron and dexamethasone (50.7% and 49.4%). Mean pain score in granisetron group was 3.16 ± 1.23, dexamethasone was 2.73 ± 1.03, and in saline group was 4.82 ± 1.73 ( P = 0.001). Mean pain intensity in granisetron group was 1.16 ± 0.18, dexamethasone was 1.26 ± 0.14, and in saline group was 2.2 ± 0.99 ( P = 0.001). There were no differences in either mean arterial pressure or O 2 Sate at any time point after drugs injection among the groups. There was a significant difference in pulse rate in third minutes between three groups and in the group who received granisetron was lesser ( P = 0.04). Pretreatment with intravenous granisetron (1 mg) and dexamethasone (0.15 mg/kg) before injection of propofol is effective and safe in reducing the incidence and severity of pain due to propofol injection.

Comparison the Effect of Granisetron and Dexamethasone on Intravenous Propofol Pain

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Leili Adinehmehr

2018-01-01

Full Text Available Background: The incidence of propofol injection pain during induction of general anesthesia varies from 28% to 90%. This prospective, randomized, double-blind, placebo-controlled study evaluated the effect of dexamethasone and granisetron for reducing the incidence and severity of propofol injection pain. Materials and Methods: A total of 227 female subjects received 5 mL of preservative-free saline, 1 mg granisetron (5 ml, or 0.15 mg/kg of dexamethasone (5 ml, intravenously, following exsanguination and occlusion of the veins of the arm. This was followed by a 0.5 mg/kg injection of propofol. Pain scores and intensity of pain recorded immediately following the injection of propofol. Hemodynamic parameters and O2sat were recorded 1, 3, 5, and 10 min after propofol injection. Results: The incidence pain following the injection of propofol was significantly decreased with both granisetron and dexamethasone (50.7% and 49.4%. Mean pain score in granisetron group was 3.16 ± 1.23, dexamethasone was 2.73 ± 1.03, and in saline group was 4.82 ± 1.73 (P = 0.001. Mean pain intensity in granisetron group was 1.16 ± 0.18, dexamethasone was 1.26 ± 0.14, and in saline group was 2.2 ± 0.99 (P = 0.001. There were no differences in either mean arterial pressure or O2Sate at any time point after drugs injection among the groups. There was a significant difference in pulse rate in third minutes between three groups and in the group who received granisetron was lesser (P = 0.04. Conclusion: Pretreatment with intravenous granisetron (1 mg and dexamethasone (0.15 mg/kg before injection of propofol is effective and safe in reducing the incidence and severity of pain due to propofol injection.

Comparison the Effect of Granisetron and Dexamethasone on Intravenous Propofol Pain

Science.gov (United States)

Adinehmehr, Leili; Salimi, Sohrab; Sane, Shahryar; Sina, Venous; Najafizadeh, Rana

2018-01-01

Background: The incidence of propofol injection pain during induction of general anesthesia varies from 28% to 90%. This prospective, randomized, double-blind, placebo-controlled study evaluated the effect of dexamethasone and granisetron for reducing the incidence and severity of propofol injection pain. Materials and Methods: A total of 227 female subjects received 5 mL of preservative-free saline, 1 mg granisetron (5 ml), or 0.15 mg/kg of dexamethasone (5 ml), intravenously, following exsanguination and occlusion of the veins of the arm. This was followed by a 0.5 mg/kg injection of propofol. Pain scores and intensity of pain recorded immediately following the injection of propofol. Hemodynamic parameters and O2 sat were recorded 1, 3, 5, and 10 min after propofol injection. Results: The incidence pain following the injection of propofol was significantly decreased with both granisetron and dexamethasone (50.7% and 49.4%). Mean pain score in granisetron group was 3.16 ± 1.23, dexamethasone was 2.73 ± 1.03, and in saline group was 4.82 ± 1.73 (P = 0.001). Mean pain intensity in granisetron group was 1.16 ± 0.18, dexamethasone was 1.26 ± 0.14, and in saline group was 2.2 ± 0.99 (P = 0.001). There were no differences in either mean arterial pressure or O2 Sate at any time point after drugs injection among the groups. There was a significant difference in pulse rate in third minutes between three groups and in the group who received granisetron was lesser (P = 0.04). Conclusion: Pretreatment with intravenous granisetron (1 mg) and dexamethasone (0.15 mg/kg) before injection of propofol is effective and safe in reducing the incidence and severity of pain due to propofol injection. PMID:29862223

Effects of progesterone injection on performance, plasma hormones ...

African Journals Online (AJOL)

PRECIOUS

2009-11-16

Nov 16, 2009 ... triggers gonadotropin-releasing hormone (GnRH) release ... open period has been shown to have positive effect on inducing a preovulatory ..... release, injectable levonorgestrel and depot medroxyprogesterone acetate on.

Fasitibant chloride, a kinin B2 receptor antagonist, and dexamethasone interact to inhibit carrageenan-induced inflammatory arthritis in rats

Science.gov (United States)

Valenti, Claudio; Giuliani, Sandro; Cialdai, Cecilia; Tramontana, Manuela; Maggi, Carlo Alberto

2012-01-01

BACKGROUND AND PURPOSE Bradykinin, through the kinin B2 receptor, is involved in inflammatory processes related to arthropathies. B2 receptor antagonists inhibited carrageenan-induced arthritis in rats in synergy with anti-inflammatory steroids. The mechanism(s) underlying this drug interaction was investigated. EXPERIMENTAL APPROACH Drugs inhibiting inflammatory mediators released by carrageenan were injected, alone or in combination, into the knee joint of pentobarbital anaesthetized rats 30 min before intra-articular administration of carrageenan. Their effects on the carrageenan-induced inflammatory responses (joint pain, oedema and neutrophil recruitment) and release of inflammatory mediators (prostaglandins, IL-1β, IL-6 and the chemokine GRO/CINC-1), were assessed after 6 h. KEY RESULTS The combination of fasitibant chloride (MEN16132) and dexamethasone was more effective than each drug administered alone in inhibiting knee joint inflammation and release of inflammatory mediators. Fasitibant chloride, MK571, atenolol, des-Arg9-[Leu8]-bradykinin (B2 receptor, leukotriene, catecholamine and B1 receptor antagonists, respectively) and dexketoprofen (COX inhibitor), reduced joint pain and, except for the latter, also diminished joint oedema. A combination of drugs inhibiting joint pain (fasitibant chloride, des-Arg9-[Leu8]-bradykinin, dexketoprofen, MK571 and atenolol) and oedema (fasitibant chloride, des-Arg9-[Leu8]-bradykinin, MK571 and atenolol) abolished the respective inflammatory response, producing inhibition comparable with that achieved with the combination of fasitibant chloride and dexamethasone. MK571 alone was able to block neutrophil recruitment. CONCLUSIONS AND IMPLICATIONS Bradykinin-mediated inflammatory responses to intra-articular carrageenan were not controlled by steroids, which were not capable of preventing bradykinin effects either by direct activation of the B2 receptor, or through the indirect effects mediated by release of eicosanoids

Experimental study on effect of dexamethasone to the in-stent restenosis after vascular intervention

International Nuclear Information System (INIS)

Wang Jianbo; Yang Jianyong; Chen Wei; Zhuang Wenquan; Li Jiaping; Zhang Longjuan

2007-01-01

Objective: To evaluate the effect of dexamethasone to the cultured rat thoracic aortic smooth muscle cells (SMC) in vitro, and explore the role on it's prevention and cure for the in-stent restenosis after vascular intervention. Methods: The rat thoracic aortic SMC were harvested and cultured for six to ten passages. The cultured SMC were synchronized and then restimutated to enter the cell cycle, and treated with incremental concentrations of dexamethasone or without dexamethasone as control. The proliferative assay was performed with MTT method in the different time points after treatment. RT-PCR was performed to assay the level of proliferating cell nuclear antigen (PCNA) mRNA. Results: 1. Dexamethasone progressively inhibited rat aortic SMC proliferation in a concentration-dependent fashion. The A value was statistically significant for different concentrations (F=36.02, P -6 and 10 -5 mol/L (P=0.065) or between 10 -11 mol/L and control group (P 0.567). 2. RT-PCR suggested dexamethasone significantly decreased rat aortic SMC PCNA mRNA transcription in a concentration-dependent fashion. Statistical analysis indicated F=15.407 and P -9 or 10 -11 mol/L groups by post hoc analysis. Conclusions: Dexamethasone inhibits rat aortic SMC proliferation in a concentration- dependent fashion. The data suggest that effective action concentration is 10 -7 mol/L with persistent time up to 96 hours or more. Dexamethasone may play the inhibit role to SMC at lower concentration with prolonging action time. (authors)

Tripeptide amide L-pyroglutamyl-histidyl-L-prolineamide (L-PHP-thyrotropin-releasing hormone, TRH) promotes insulin-producing cell proliferation.

Science.gov (United States)

Luo, LuGuang; Luo, John Z Q; Jackson, Ivor

2013-02-01

A very small tripeptide amide L-pyroglutamyl-L-histidyl-L-prolineamide (L-PHP, Thyrotropin-Releasing Hormone, TRH), was first identified in the brain hypothalamus area. Further studies found that L-PHP was expressed in pancreas. The biological role of pancreatic L-PHP is still not clear. Growing evidence indicates that L-PHP expression in the pancreas may play a pivotal role for pancreatic development in the early prenatal period. However, the role of L-PHP in adult pancreas still needs to be explored. L-PHP activation of pancreatic β cell Ca2+ flow and stimulation of β-cell insulin synthesis and release suggest that L-PHP involved in glucose metabolism may directly act on the β cell separate from any effects via the central nervous system (CNS). Knockout L-PHP animal models have shown that loss of L-PHP expression causes hyperglycemia, which cannot be reversed by administration of thyroid hormone, suggesting that the absence of L-PHP itself is the cause. L-PHP receptor type-1 has been identified in pancreas which provides a possibility for L-PHP autocrine and paracrine regulation in pancreatic function. During pancreatic damage in adult pancreas, L-PHP may protect beta cell from apoptosis and initiate its regeneration through signal pathways of growth hormone in β cells. L-PHP has recently been discovered to affect a broad array of gene expression in the pancreas including growth factor genes. Signal pathways linked between L-PHP and EGF receptor phosphorylation suggest that L-PHP may be an important factor for adult β-cell regeneration, which could involve adult stem cell differentiation. These effects suggest that L-PHP may benefit pancreatic β cells and diabetic therapy in clinic.

Targeting Dexamethasone to Macrophages in a Porcine Endotoxemic Model

DEFF Research Database (Denmark)

Granfeldt, Asger; Hvas, Christine Lodberg; Graversen, Jonas Heilskov

2013-01-01

-8 minutes. CONCLUSION: Targeted delivery of dexamethasone to macrophages using a humanized CD163 antibody as carrier exhibits anti-inflammatory effects comparable with 50 times higher concentrations of free dexamethasone and does not inhibit endogenous cortisol production. This antibody-drug complex showing......OBJECTIVES: Macrophages are important cells in immunity and the main producers of pro-inflammatory cytokines. The main objective was to evaluate if specific delivery of glucocorticoid to the macrophage receptor CD163 is superior to systemic glucocorticoid therapy in dampening the cytokine response...

Pituitary Apoplexy After Thyrotropin-releasing Hormone Stimulation Test in a Patient with Pituitary Macroadenoma

Directory of Open Access Journals (Sweden)

Huei-Fang Wang

2007-09-01

Full Text Available Pituitary apoplexy is a rare complication of pituitary tumors. We report a case of a 41-year-old female with acromegaly due to a pituitary macroadenoma, who developed pituitary apoplexy after a thyrotropin-releasing hormone (TRH 200 mg intravenous injection stimulation test. Neither emergency computed tomography (CT scans nor magnetic resonance imaging (MRI, performed 6 hours and 12 hours, respectively, after the active episode, disclosed the evidence of acute hemorrhage or infarction. Two days later, the pituitary mass, removed by transsphenoidal approach, showed ischemic necrosis and acute hemorrhage. The TRH test is generally safe for evaluating pituitary function, but pituitary apoplexy may occur after the procedure. CT and MRI may miss the diagnosis of pituitary apoplexy, especially if performed immediately after the acute episode.

Long-term Effects of Dexamethasone on Reproductive Parameters in Male Mice

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jalogoden Gouyandeh

2015-02-01

Full Text Available Background & aim: The adverse effect of chemical drugs such as dexamethasone as anti-inflammatory -steroidal drugs on different body systems and infertility and reproductive efficiency is of concern. The purpose of this study was to evaluate the long-term effects of dexamethasone on the reproductive system in male rats. Methods: In the present experimental study, fifty matured male mice were divided into five groups including control, placebo and three treatment groups. Control group had no injections, placebo group only received normal saline and treatments groups received dexamethasone (0.1, 0.5 and 1 mg/kg which was injected in peritoneum every other day for a period of twenty days. Their Testosterone was measured by ELISA and testes were dissected for histological examination. The data were analyzed using SPSS 11.5 software. Results: Significant increases were shown in FSH level in all three groups treated with dexamethasone. LH in treatment group of 0.1 mg/kg decreased, but at dose of 1 mg/kg increased significantly.Testosterone levels in a dose of 1 mg/kg significantly increased compared with the control group (p<0.05. However, testis weight, the rate of testicular germ cells, primary spermatocytes, epididymal sperm and fertility significantly increased in all three groups (p<0.05. Conclusion: Dexamethasone had a negative effect on reproduction therefore, the use of this medication at different doses and time periods considers the possible complications beforehand. Keywords: .

Polymorphisms and haplotypes in the bovine neuropeptide Y, growth hormone receptor, ghrelin, insulin-like growth factor 2, and uncoupling proteins 2 and 3 genes and their associations with measures of growth, performance, feed efficiency, and carcass merit in beef cattle.

Science.gov (United States)

Sherman, E L; Nkrumah, J D; Murdoch, B M; Li, C; Wang, Z; Fu, A; Moore, S S

2008-01-01

Genes that regulate metabolism and energy partitioning have the potential to influence economically important traits in farm animals, as do polymorphisms within these genes. In the current study, SNP in the bovine neuropeptide Y (NPY), growth hormone receptor (GHR), ghrelin (GHRL), uncoupling proteins 2 and 3 (UCP2 and UCP3), IGF2, corticotrophin-releasing hormone (CRH), cocaine and amphetamine regulated transcript (CART), melanocortin-4 receptor (MC4R), proopiomelanocortin (POMC), and GH genes were evaluated for associations with growth, feed efficiency, and carcass merit in beef steers. In total, 24 SNP were evaluated for associations with these traits and haplotypes were constructed within each gene when 2 or more SNP showed significant associations. An A/G SNP located in intron 4 of the GHR gene had the largest effects on BW of the animals (dominance effect P GHRL gene tended to show effects on residual feed intake, FCR, and partial efficiency of growth (P < 0.10). The IGF2 SNP most strongly affected LM area (P < 0.01), back fat, ADG, and FCR (P < 0.05). The SNP in the CART, MC4R, POMC, GH, and CRH genes did not show associations at P < 0.05 with any of the traits. Although most of the SNP that showed associations do not cause amino acid changes, these SNP could be linked to other yet to be detected causative mutations or nearby QTL. It will be very important to verify these results in other cattle populations.

Gonadotropin-releasing hormone regulates expression of the DNA damage repair gene, Fanconi anemia A, in pituitary gonadotroph cells.

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Larder, Rachel; Chang, Lynda; Clinton, Michael; Brown, Pamela

2004-09-01

Gonadal function is critically dependant on regulated secretion of the gonadotropin hormones from anterior pituitary gonadotroph cells. Gonadotropin biosynthesis and release is triggered by the binding of hypothalamic GnRH to GnRH receptor expressed on the gonadotroph cell surface. The repertoire of regulatory molecules involved in this process are still being defined. We used the mouse L beta T2 gonadotroph cell line, which expresses both gonadotropin hormones, as a model to investigate GnRH regulation of gene expression and differential display reverse transcription-polymerase chain reaction (RT-PCR) to identify and isolate hormonally induced changes. This approach identified Fanconi anemia a (Fanca), a gene implicated in DNA damage repair, as a differentially expressed transcript. Mutations in Fanca account for the majority of cases of Fanconi anemia (FA), a recessively inherited disease identified by congenital defects, bone marrow failure, infertility, and cancer susceptibility. We confirmed expression and hormonal regulation of Fanca mRNA by quantitative RT-PCR, which showed that GnRH induced a rapid, transient increase in Fanca mRNA. Fanca protein was also acutely upregulated after GnRH treatment of L beta T2 cells. In addition, Fanca gene expression was confined to mature pituitary gonadotrophs and adult mouse pituitary and was not expressed in the immature alpha T3-1 gonadotroph cell line. Thus, this study extends the expression profile of Fanca into a highly specialized endocrine cell and demonstrates hormonal regulation of expression of the Fanca locus. We suggest that this regulatory mechanism may have a crucial role in the GnRH-response mechanism of mature gonadotrophs and perhaps the etiology of FA.

Development of Gonadotropin-Releasing Hormone-Secreting Neurons from Human Pluripotent Stem Cells

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Carina Lund

2016-08-01

Full Text Available Gonadotropin-releasing hormone (GnRH neurons regulate human puberty and reproduction. Modeling their development and function in vitro would be of interest for both basic research and clinical translation. Here, we report a three-step protocol to differentiate human pluripotent stem cells (hPSCs into GnRH-secreting neurons. Firstly, hPSCs were differentiated to FOXG1, EMX2, and PAX6 expressing anterior neural progenitor cells (NPCs by dual SMAD inhibition. Secondly, NPCs were treated for 10 days with FGF8, which is a key ligand implicated in GnRH neuron ontogeny, and finally, the cells were matured with Notch inhibitor to bipolar TUJ1-positive neurons that robustly expressed GNRH1 and secreted GnRH decapeptide into the culture medium. The protocol was reproducible both in human embryonic stem cells and induced pluripotent stem cells, and thus provides a translational tool for investigating the mechanisms of human puberty and its disorders.

No association of CRH1 receptor polymorphism haplotypes, harm avoidance and other personality dimensions in alcohol dependence: results from the Munich gene bank project for alcoholism.

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Soyka, M; Preuss, U W; Koller, G; Zill, P; Hesselbrock, V; Bondy, B

2004-03-01

Because corticotrophin-releasing hormone (CRH) plays a central role in stress regulation, the possible role of CRH1 polymorphism for anxiety-related personality variables such as harm avoidance possibly associated with alcoholism was studied. The research instruments used to phenotype patients were adopted partly from the US collaborative study of the genetics of alcoholism and include a number of personality inventories such as the temperament and character inventory (TCI). Based on the examination of 170 alcoholic subjects no association was found between CRH1 receptor haplotypes of four single nuclotid polymorphisms (SNPs) and low and high temperament traits of harm avoidance, novelty seeking and reward dependence. The possible implications of these findings are discussed.

The use of gonadotrophin-releasing hormone antagonists in polycystic ovarian disease.

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Lubin, V; Charbonnel, B; Bouchard, P

1998-12-01

Polycystic ovarian disease (PCOD) is characterized by anovulation, eventually high luteinizing hormone (LH) levels, with increased LH pulse frequency, and hyperandrogenism. As the aetiology of the disease is still unknown, gonadotrophin-releasing hormone (GnRH) antagonists, competitive inhibitors of GnRH for its receptor, are interesting tools in order to study and treat the role of increased LH levels and pulse frequency in this disease. Their administration provokes a rapid decrease in bioactive and immunoactive LH followed by a slower decrease in follicle-stimulating hormone (FSH). In patients with PCOD, the suppression of gonadotrophin secretion eradicates the symptoms of the disease as long as the treatment lasts. Several authors have suggested that increased plasma LH levels have deleterious effects on the fertility of women with PCOD. Indeed, fewer spontaneous pregnancies with more miscarriages are observed when plasma LH levels are high. Assisted reproduction techniques such as in vitro fertilization (IVF) have provided other clues to the role of the LH secretory pattern in women with PCOD. The number of oocytes retrieved, the fertilization rate and the cleavage rate are lower in PCOD patients undergoing IVF and this is inversely correlated with FSH:LH ratio. These abnormalities are corrected when endogenous secretion of LH is suppressed. On the other hand, implantation and pregnancy rates after IVF are similar to those observed in control women. New GnRH antagonists are devoid of side effects and suppress LH secretion within a few hours without a flare-up effect. This action lasts for 10-100 hours. When GnRH antagonists are associated with i.v. pulsatile GnRH, this combination both suppresses the effect of endogenous GnRH and because of the competition for GnRH receptors restores a normal frequency of LH secretion. We have studied two women with PCOD, administering first 10 mg s.c. every 72 hours for 7 days of the GnRH antagonist Nal-Glu, then adding on

Dexamethasone-induced and estradiol-induced CREB activation and annexin 1 expression in CCRF-CEM lymphoblastic cells: evidence for the involvement of cAMP and p38 MAPK

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M. Castro-caldas

2003-01-01

Full Text Available Aims: Annexin 1 (ANXA1, a member of the annexin family of calcium-binding and phospholipid-binding proteins, is a key mediator of the anti-inflammatory actions of steroid hormones. We have previously demonstrated that, in the human lymphoblastic CCRF-CEM cell line, both the synthetic glucocorticoid hormone, dexamethasone (Dex, and the estrogen hormone, 17β-estradiol (E2β, induce the synthesis of ANXA1, by a mechanism independent of the activation of their nuclear receptors. Recently, it was reported that the gene coding for ANXA1 contains a cAMP-responsive element (CRE. In this work, we investigated whether Dex and E2β were able to induce the activation of CRE binding proteins (CREB in the CCRF-CEM cells. Moreover, we studied the intracellular signalling pathways involved in CREB activation and ANXA1 synthesis in response to Dex and E2β; namely, the role of cAMP and the p38 mitogen-activated protein kinase (MAPK.

Dexamethasone Treatment Leads to Enhanced Fear Extinction and Dynamic Fkbp5 Regulation in Amygdala.

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Sawamura, Takehito; Klengel, Torsten; Armario, Antonio; Jovanovic, Tanja; Norrholm, Seth D; Ressler, Kerry J; Andero, Raül

2016-02-01

Posttraumatic stress disorder (PTSD) is both a prevalent and debilitating trauma-related disorder associated with dysregulated fear learning at the core of many of its signs and symptoms. Improvements in the currently available psychological and pharmacological treatments are needed in order to improve PTSD treatment outcomes and to prevent symptom relapse. In the present study, we used a putative animal model of PTSD that included presentation of immobilization stress (IMO) followed by fear conditioning (FC) a week later. We then investigated the acute effects of GR receptor activation on the extinction (EXT) of conditioned freezing, using dexamethasone administered systemically which is known to result in suppression of the HPA axis. In our previous work, IMO followed by tone-shock-mediated FC was associated with impaired fear EXT. In this study, we administered dexamethasone 4 h before EXT training and then examined EXT retention (RET) 24 h later to determine whether dexamethasone suppression rescued EXT deficits. Dexamethasone treatment produced dose-dependent enhancement of both EXT and RET. Dexamethasone was also associated with reduced amygdala Fkbp5 mRNA expression following EXT and after RET. Moreover, DNA methylation of the Fkbp5 gene occurred in a dose-dependent and time course-dependent manner within the amygdala. Additionally, we found dynamic changes in epigenetic regulation, including Dnmt and Tet gene pathways, as a function of both fear EXT and dexamethasone suppression of the HPA axis. Together, these data suggest that dexamethasone may serve to enhance EXT by altering Fkbp5-mediated glucocorticoid sensitivity via epigenetic regulation of Fkbp5 expression.

Melatonin attenuates prenatal dexamethasone-induced blood pressure increase in a rat model.

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Tain, You-Lin; Chen, Chih-Cheng; Sheen, Jiunn-Ming; Yu, Hong-Ren; Tiao, Mao-Meng; Kuo, Ho-Chang; Huang, Li-Tung

2014-04-01

Although antenatal corticosteroid is recommended to accelerate fetal lung maturation, prenatal dexamethasone exposure results in hypertension in the adult offspring. Since melatonin is a potent antioxidant and has been known to regulate blood pressure, we examined the beneficial effects of melatonin therapy in preventing prenatal dexamethasone-induced programmed hypertension. Male offspring of Sprague-Dawley rats were assigned to four groups (n = 12/group): control, dexamethasone (DEX), control + melatonin, and DEX + melatonin. Pregnant rats received intraperitoneal dexamethasone (0.1 mg/kg) from gestational day 16 to 22. In the melatonin-treatment groups, rats received 0.01% melatonin in drinking water during their entire pregnancy and lactation. Blood pressure was measured by an indirect tail-cuff method. Gene expression and protein levels were analyzed by real-time quantitative polymerase chain reaction and Western blotting, respectively. At 16 weeks of age, the DEX group developed hypertension, which was partly reversed by maternal melatonin therapy. Reduced nephron numbers due to prenatal dexamethasone exposure were prevented by melatonin therapy. Renal superoxide and NO levels were similar in all groups. Prenatal dexamethasone exposure led to increased mRNA expression of renin and prorenin receptor and up-regulated histone deacetylase (HDAC)-1 expression in the kidneys of 4-month-old offspring. Maternal melatonin therapy augmented renal Mas protein levels in DEX + melatonin group, and increased renal mRNA expression of HDAC-1, HDAC-2, and HDAC-8 in control and DEX offspring. Melatonin attenuated prenatal DEX-induced hypertension by restoring nephron numbers, altering RAS components, and modulating HDACs. Copyright © 2014 American Society of Hypertension. Published by Elsevier Inc. All rights reserved.

Effects of methimazole treatment on growth hormone (GH) response to GH-releasing hormone in patients with hyperthyroidism.

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Giustina, A; Ferrari, C; Bodini, C; Buffoli, M G; Legati, F; Schettino, M; Zuccato, F; Wehrenberg, W B

1990-12-01

In vitro studies have demonstrated that thyroid hormones can enhance basal and stimulated growth hormone secretion by cultured pituitary cells. However, both in man and in the rat the effects of high thyroid hormone levels on GH secretion are unclear. The aim of our study was to test the GH response to human GHRH in hyperthyroid patients and to evaluate the effects on GH secretion of short- and long-term pharmacological decrease of circulating thyroid hormones. We examined 10 hyperthyroid patients with recent diagnosis of Graves' disease. Twelve healthy volunteers served as controls. All subjects received a bolus iv injection of GHRH(1-29)NH2, 100 micrograms. Hyperthyroid patients underwent a GHRH test one and three months after starting antithyroid therapy with methimazole, 10 mg/day po. GH levels at 15, 30, 45, 60 min and GH peak after stimulus were significantly lower in hyperthyroid patients than in normal subjects. The GH peak was also delayed in hyperthyroid patients. After one month of methimazole therapy, most of the hyperthyroid patients had thyroid hormone levels in the normal range, but they did not show significant changes in GH levels after GHRH, and the GH peak was again delayed. After three months of therapy with methimazole, the hyperthyroid patients did not show a further significant decrease in serum thyroid hormone levels. However, mean GH levels from 15 to 60 min were significantly increased compared with the control study. The GH peak after GHRH was also earlier than in the pre-treatment study.(ABSTRACT TRUNCATED AT 250 WORDS)

Does Dexamethasone Helps in Meningococcal Sepsis?

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Tolaj, Ilir; Ramadani, Hamdi; Mehmeti, Murat; Gashi, Hatixhe; Kasumi, Arbana; Gashi, Visar; Jashari, Haki

2017-01-01

Purpose: Prompt recognition and aggressive early treatment are the only effective measures against invasive meningococcal disease (IMD). Anti-inflammatory adjunctive treatment remains controversial and difficult to assess in patients with IMD. The purpose of this study was to evaluate the effect of dexamethasone (DXM) as adjunctive treatment in different clinical forms of IMD, and attempt to answer if DXM should be routinely used in the treatment of IMD. Methods: In this non-interventional clinical study (NIS), 39 patients with meningococcal septicaemia with or without of meningitis were included, and compared regarding the impact of dexamethasone (DXM), as an adjunctive treatment, on the outcome of IMD. SPSS statistics is used for statistical processing of data. Results: Thirty (76.9%) patients with IMD had sepsis and meningitis, and 9 (23.1%) of them had sepsis alone. Dexamethasone was used in 24 (61.5%) cases, in both clinical groups. The overall mortality rate was 10.3%. Pneumonia was diagnosed in 6 patients (15.4%), arthritis in 3 of them (7.7%), and subdural effusion in one patient (2.6%). The data showed a significant statistical difference on the length of hospitalization, and WBC normalization in groups of patients treated with DXM. Conclusion: The use of DXM as adjunctive therapy in invasive meningococcal disease has a degree of proven benefits and no harmful effects. In fighting this very dangerous and complex infection, even a limited benefit is sufficient to recommend the use of DXM as adjunctive treatment in invasive meningococcal disease. PMID:28974828

Role of dexamethasone in brachial plexus block

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Dawood, M.

2015-01-01

To evaluate the effect of dexamethasone added to (lignocaine) on the onset and duration of axillary brachial plexus block. Study Design: Randomized controlled trial. Place and Duration of Study: Combined Military Hospital Rawalpindi, from September 2009 to March 2010. Patients and Methods: A total of 100 patients, who were scheduled for elective hand and forearm surgery under axillary brachial plexus block, were randomly allocated to group A in which patients received 40 ml 1.5% lidocaine with 2 ml of isotonic saline (0.9%) and group B in which patients received 40 ml 1.5% lidocaine with 2 ml of dexamethasone (8 mg). Nerve stimulator with insulated needle for multiple stimulations technique was used to locate the brachial plexus nerves. After the injection onset of action and duration of sensory blockade of brachial plexus were recorded at 5 minutes and 15 minutes interval. Results: Group A showed the onset of action of 21.64 ± 2.30 min and in group B it was 15.42 ± 1.44 min (p< 0.001). Duration of nerve block was 115.08 ± 10.92 min in group A and 265.42 ± 16.56 min in group B (p < 0.001). Conclusion: The addition of dexamethasone to 1.5% lignocaine solution in axillary brachial plexus block prolongs the duration of sensory blockade significantly. (author)

Adult height in girls with central precocious puberty treated with gonadotropin-releasing hormone agonist with or without growth hormone

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Mo Kyung Jung

2014-12-01

Full Text Available PurposeThere is controversy surrounding the growth outcomes of treatment with gonadotropin-releasing hormone agonist (GnRHa in central precocious puberty (CPP. We analyzed height preservation after treatment with GnRHa with and without growth hormone (GH in girls with CPP.MethodsWe reviewed the medical records of 82 girls with idiopathic CPP who had been treated with GnRHa at Severance Children's Hospital from 2004 to 2014. We assessed the changes in height standard deviation score (SDS for bone age (BA, and compared adult height (AH with midparental height (MPH and predicted adult height (PAH during treatment in groups received GnRHa alone (n=59 or GnRHa plus GH (n=23.ResultsIn the GnRHa alone group, the height SDS for BA was increased during treatment. AH (160.4±4.23 cm was significantly higher than the initial PAH (156.6±3.96 cm (P<0.001, and it was similar to the MPH (159.9±3.52 cm. In the GnRHa plus GH group, the height SDS for BA was also increased during treatment. AH (159.3±5.33 cm was also higher than the initial PAH (154.6±2.55 cm (P<0.001, which was similar to the MPH (158.1±3.31 cm. Height gain was slightly higher than that in the GnRHa alone group, however it statistically showed no significant correlation with GH treatment.ConclusionIn CPP girls treated with GnRHa, the height SDS for BA was increased, and the AH was higher than the initial PAH. Combined GH treatment showed a limited increase in height gain.

Prenatal stress may increase vulnerability to life events comparison with the effects of prenatal dexamethasone

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Hougaard, Karin; Andersen, Maibritt B; Kjaer, Sanna L

2005-01-01

naïve at the time of ASR testing, whereas the other had been through blood sampling for assessment of the hormonal stress response to restraint, 3 months previously. Both prenatal CMS and dexamethasone increased ASR in the offspring compared to controls, but only in prenatally stressed offspring......Prenatal stress has been associated with a variety of alterations in the offspring. The presented observations suggest that rather than causing changes in the offspring per se, prenatal stress may increase the organism's vulnerability to aversive life events. Offspring of rat dams stressed...... of the acoustic startle response. Further, a single aversive life event showed capable of changing the reactivity of prenatally stressed offspring, whereas offspring of dams going through a less stressful gestation was largely unaffected by this event. This suggests that circumstances dating back to the very...

Low-Dose Dexamethasone Therapy from Infancy of Virilizing Congenital Adrenal Hyperplasia

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Stephenson Kerry

2009-12-01

Full Text Available Objective. To assess the growth and control of adrenal androgen secretion in children with virilizing congenital adrenal hyperplasia (CAH treated with dexamethasone. Method. We examined doses used, control of adrenal androgen secretion, and growth and skeletal maturation of 8 children with CAH treated with dexamethasone beginning in infancy. Results. 3 boys and 5 girls with classical CAH (17-hydroxyprogesterone at diagnosis >20,000 ng/dL were treated with dexamethasone beginning at diagnosis ( ; all doses were given in the morning using a dosing syringe to administer a 0.1 mg/mL elixir. The children were treated for years over which time the change in bone age to chronological age ratio (BA/CA was . Most recent height Z' scores were , and body mass index (BMI scores were . Late afternoon levels of 17-hydroxyprogesterone, androstenedione, and testosterone were  ng/dL ( nmol/L,  ng/dL ( nmol/L, and  ng/dL; ( nmol/L, respectively. Conclusions. These observations show that low doses of dexamethasone can be used to effectively treat CAH beginning in infancy.

A radioreceptor assay of luteinizing hormone-releasing hormone receptor and characterization of LHRH binding to pituitary receptors in Shao duck

International Nuclear Information System (INIS)

Yang Peixin; Wu Meiwen; Chen Ziyuan

2000-01-01

The properties of Shao duck pituitary luteinizing hormone-releasing hormone (LHRH) receptors were analyzed in pituitary membrane preparation and isolated pituitary cells prepared by enzymatic dispersion with collagenase and trypsin, by using a super-agonist analog of (D-Lys 6 ) LHRH. High binding of 125 I-(D-Lys 6 ) LHRH to 10 6 cultured cells of Shao duck was observed after a 90 minute incubation at 4 degree C, while binding was significantly reduced after a 24h incubation. Binding of the radioligand was a function of tissue concentration of Shao duck pituitary membrane preparation, with a positive correlation over the range of 1-2 pituitary per-tube. Specific binding for 125 I-(D-Lys 6 ) LHRH increased with the increase in the amount of 125 I-(D-Lys 6 ) LHRH. The Scatchard analysis of data revealed a linear relationship between the amount of specific binding and the ratio of specific binding to free 1 '2 5 I(D-Lys 6 )LHRH, indicating a single class of high affinity sites. Equilibrium dissociation constant (Kd) was 0.34 nM in pituitary membrane preparation and 0.43 nM in isolated pituitary cells. Both Kd values were near and the maximum binding capacity (B max ) was great in isolated cells, suggesting no significant loss of the LHRH receptor population caused by the enzymatic procedure employed for cell dispersion in the present study. Addition of 9D-Lys 6 ) LHRH displaced bound 125 I-(D-Lys 6 ) LHRH. These results demonstrated the presence and provided characterization of LHRH receptors in Shao duck pituitary

Effects of long-term intraperitoneal injection of thyrotropin-releasing hormone (TRH) on aging- and obesity-related changes in body weight, lipid metabolism, and thyroid functions.

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Pierpaoli, Walter; Lesnikov, Vladimir A

2011-02-01

Adult adipose mice, high fat diet-fed (HFD) mice, anterior hypothalamus-lesioned obese mice and genetically obese mice, were injected daily with thyrotropin releasing hormone (TRH). The treatment provoked a mobilization of triglycerides in the peripheral blood, a decrease of leptin and a loss of body weight. The weight loss did not depend on TSH-mediated stimulation of thyroid hormone secretion with consequent metabolic hyperthyroidism. The levels of blood cholesterol were not affected or even suppressed. Even at a very high dosage TRH did not affect the obesity of genetically obese mice. The ubiquitous tripeptide TRH may thus constitute a key element in the hormone-controlled regulation of body weight and fat stores in the adult and aging body.

Molecular Cloning, Genomic Organization and Developmental Regulation of a Novel Receptor from Drosophila melanogaster Structurally Related to Gonadotropin-Releasing Hormone Receptors from Vertebrates

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Hauser, Frank; Søndergaard, Leif; Grimmelikhuijzen, Cornelis J.P.

1998-01-01

After screening the data base of the BerkeleyDrosophilaGenome Project with a sequence coding for the transmembrane region of a G protein-coupled receptor, we found thatDrosophilamight contain a gene coding for a receptor that is structurally related to the Gonadotropin-Releasing Hormone (GnRH) re...

Removal of dexamethasone from aqueous solution and hospital wastewater by electrocoagulation

International Nuclear Information System (INIS)

Arsand, Daniel R.; Kümmerer, Klaus; Martins, Ayrton F.

2013-01-01

This study is concerned with the removal of the anti-inflammatory dexamethasone from aqueous solution and hospital wastewater by electrocoagulation. The variation of the toxicity during the electrocoagulation was also studied through experiments that were designed and optimized by means of response surface methodology. The coagulation efficiency was evaluated by measuring the dexamethasone concentration by high performance liquid chromatography coupled to a diode array detector. In addition, variation was evaluated through a Vibrio fischeri test. The results showed an increase in the removal of dexamethasone (up to 38.1%) with a rise of the current applied and a decrease of the inter-electrode distance, in aqueous solutions. The application to hospital effluent showed similar results for the removal of dexamethasone. The main effect of the electrocoagulation was that it removed colloids and reduced the organic load of the hospital wastewater. Regarding the current applied, the calculated energy efficiency was 100%. Without pH adjustment of the aqueous solution or hospital wastewater, the residual aluminum concentration always remained lower than 10 mg L −1 , and, with adjustment (to pH 6.5), lower than 0.30 mg L −1 , at the final stage. No toxicity variation was observed during the electrocoagulation process in aqueous solution, either in the presence or absence of dexamethasone. - Highlights: ► Removal of DEX and organic load from aqueous solution and hospital wastewater by EC ► Evaluation of the toxicity during the removal of DEX by EC ► Suggestion of the EC process as a pretreatment for subsequent processes

Removal of dexamethasone from aqueous solution and hospital wastewater by electrocoagulation

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Arsand, Daniel R., E-mail: danielarsand@pelotas.ifsul.edu.br [Chemistry Department, Federal University of Santa Maria, RS (Brazil); Kümmerer, Klaus, E-mail: klaus.kuemmerer@leuphana.de [Institute for Environmental Chemistry, Leuphana University Lüneburg (Germany); Martins, Ayrton F., E-mail: martins@quimica.ufsm.br [Chemistry Department, Federal University of Santa Maria, RS (Brazil)

2013-01-15

This study is concerned with the removal of the anti-inflammatory dexamethasone from aqueous solution and hospital wastewater by electrocoagulation. The variation of the toxicity during the electrocoagulation was also studied through experiments that were designed and optimized by means of response surface methodology. The coagulation efficiency was evaluated by measuring the dexamethasone concentration by high performance liquid chromatography coupled to a diode array detector. In addition, variation was evaluated through a Vibrio fischeri test. The results showed an increase in the removal of dexamethasone (up to 38.1%) with a rise of the current applied and a decrease of the inter-electrode distance, in aqueous solutions. The application to hospital effluent showed similar results for the removal of dexamethasone. The main effect of the electrocoagulation was that it removed colloids and reduced the organic load of the hospital wastewater. Regarding the current applied, the calculated energy efficiency was 100%. Without pH adjustment of the aqueous solution or hospital wastewater, the residual aluminum concentration always remained lower than 10 mg L{sup −1}, and, with adjustment (to pH 6.5), lower than 0.30 mg L{sup −1}, at the final stage. No toxicity variation was observed during the electrocoagulation process in aqueous solution, either in the presence or absence of dexamethasone. - Highlights: ► Removal of DEX and organic load from aqueous solution and hospital wastewater by EC ► Evaluation of the toxicity during the removal of DEX by EC ► Suggestion of the EC process as a pretreatment for subsequent processes.

Dexamethasone and sodium carboxymethyl cellulose prevent postoperative intraperitoneal adhesions in rats

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X.H. Du

2015-04-01

Full Text Available We aimed to evaluate the effects of the barrier agent sodium carboxymethyl cellulose (SCMC with and without dexamethasone for the prevention of postoperative adhesion formation in a rat model of postoperative peritoneal adhesion. A total of 160 three-month old male and female Wistar rats underwent a laparotomy, and adhesions were induced by ileocecal abrasion. Rats were randomly assigned to 4 groups (n=40 each: group A, untreated; group B, treated with SCMC only; group C1, treated with SCMC + 3 mg dexamethasone, and group C2, treated with SCMC + 8 mg dexamethasone. After 12 days, adhesion formation and histopathological changes were compared. In groups A, B, C1, and C2, the mortality rates were 10, 5, 5, and 5%, respectively. In groups C1 and C2, the adhesions were filmy and easy to dissect and were milder compared with those in groups A and B. The total adhesion score in group C1 (3.38±0.49 was significantly lower than that of group B (6.01±0.57; P<0.01 or group A (8.01±0.67; P<0.05. There was no significant difference in adhesion formation between groups C1 and C2. Compared with groups A and B, groups C1 and C2 exhibited milder histopathological changes. SCMC in combination with dexamethasone can prevent adhesion formation and is a better barrier agent than SCMC alone. The safety and feasibility of SCMC in combination with dexamethasone to prevent adhesion formation after abdominal surgery warrants further clinical study.

An oral multiparticulate, modified-release, hydrocortisone replacement therapy that provides physiological cortisol exposure.

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Whitaker, Martin; Debono, Miguel; Huatan, Hiep; Merke, Deborah; Arlt, Wiebke; Ross, Richard J

2014-04-01

It is not possible with current hydrocortisone replacement to mimic the diurnal cortisol profile in patients with adrenal insufficiency. Previous attempts with modified-release technology were unsuccessful. Our objective was to develop hydrocortisone formulations that recreate the diurnal cortisol profile using multiparticulate technology. Screening by in vitro dissolution profiles, pharmacokinetic (PK) testing in dexamethasone-suppressed dogs and humans, and comparison with a reference population. Field laboratories and clinical research facility. Formulations were generated using an enteric (delayed release) design configuration with an extended (sustained release) dissolution profile. In vitro dissolution confirmed delayed and sustained hydrocortisone release. However, in dogs and humans, sustained release resulted in reduced bioavailability. A formulation, DIURF-006, was developed that maintained delayed release but omitted the sustained-release functionality. PK characterization of DIURF-006 showed that, despite absence of a sustained-release component, absorption was sufficiently sustained to deliver extended hydrocortisone absorption. In dexamethasone-suppressed volunteers (n = 16) receiving a twice-daily 'toothbrush' regimen (20 mg at 23:00 h and 10 mg at 07:00 h), DIURF-006 gave a similar cortisol profile to physiological cortisol levels: DIURF-006 vs physiological, Geomean AUC 5610 vs 4706 h * nmol/l, Geomean Cmax 665 vs 594 nmol/l and Median Tmax 8·5 h vs clock time 08:12 h for peak cortisol. The relative bioavailability of DIURF-006 vs hydrocortisone was 89%, and cortisol levels increased linearly with doses between 5 and 30 mg. A multiparticulate oral hydrocortisone formulation with only an enteric coat provides delayed and sustained absorption and when given in a 'toothbrush' regimen provides physiological cortisol exposure. © 2013 John Wiley & Sons Ltd.

AMERICAN ASSOCIATION OF CLINICAL ENDOCRINOLOGISTS AND AMERICAN COLLEGE OF ENDOCRINOLOGY DISEASE STATE CLINICAL REVIEW: DIAGNOSIS OF RECURRENCE IN CUSHING DISEASE.

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Fleseriu, Maria; Hamrahian, Amir H; Hoffman, Andrew R; Kelly, Daniel F; Katznelson, Laurence

2016-12-01

Recurrence of hypercortisolemia after initial treatment of Cushing disease (CD) is more common than previously thought, with a third of patients suffering a recurrence over their lifetime. Awareness of this high rate and delayed timeline (sometimes decades) of potential recurrence is critical and patients with CD should be monitored at regular intervals throughout their lives. In this manuscript, we review the complex evaluation needed for defining CD remission versus persistent disease after surgery, and focus on challenges in diagnosing early recurrent hypercortisolemia. Late night salivary cortisol appears to be an earlier predictor of recurrence when compared with urinary free cortisol (UFC) excretion. We also review the criteria suggested to define recurrence of hypercortisolemia in patients treated with medical therapy. Further research is needed to determine the optimal way to evaluate a patient with CD recurrence as well as the riskbenefit ratio of treatment in early, mild recurrent disease. ACTH = adrenocorticotropic hormone AI = adrenal insufficiency CD = Cushing disease CDDT = coupled dexamethasone desmopressin test CR = circadian rhythm CRH = corticotropin-releasing hormone GC = glucocorticoid GCR = global clinical response HPA = hypothalamic-pituitary-adrenal LDDST = low-dose dexamethasone suppression test LNSC = late-night salivary cortisol ODST = overnight dexamethasone suppression test TSS = trans-sphenoidal surgery.

Effects of a gonadotropin-releasing hormone vaccine on ovarian cyclicity and uterine morphology of an Asian elephant (Elephas maximus).

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Boedeker, Nancy C; Hayek, Lee-Ann C; Murray, Suzan; de Avila, David M; Brown, Janine L

2012-09-01

This report describes the successful use of a gonadotropin-releasing hormone (GnRH) vaccine to suppress ovarian steroidogenic activity and to treat hemorrhage and anemia associated with reproductive tract pathology in a 59-year-old Asian elephant (Elephas maximus). The Repro-BLOC GnRH vaccine was administered subcutaneously as a series of 4 boosters of increasing dose from 3 to 30 mg of recombinant ovalbumin-GnRH fusion protein given at variable intervals after initial vaccination with 3 mg protein. Efficacy was confirmed over a year after initial vaccination based on complete ovarian cycle suppression determined by serum progestagen analyses. Estrous cycle suppression was associated with a significant increase in GnRH antibody binding and subsequent decrease in serum luteinizing hormone and follicle-stimulating hormone concentrations. Ultrasonographic examinations of the reproductive tract documented a reduction in uterine size and vascularity after immunization. The hematocrit level normalized soon after the initial intrauterine hemorrhage, and no recurrence of anemia has been detected. No substantive adverse effects were associated with GnRH vaccination. The results indicate that GnRH vaccination in elephants shows potential for contraception and management of uterine pathology in older elephants.

Hormone-refractory prostate cancer and the skeleton

NARCIS (Netherlands)

Soerdjbalie-Maikoe, Vidija

2006-01-01

Prostate cancer is the second most common cancer in men in the UK. Androgen ablation with luteinising hormone-releasing hormone agonists (LHRH agonists) alone, or in combination with anti-androgens is the standard treatment for men with metastatic prostate cancer. Unfortunately, despite maximal

Molecular and functional characterization of a novel gonadotropin-releasing-hormone receptor isolated from the common octopus (Octopus vulgaris)

OpenAIRE

Kanda, Atsuhiro; Takahashi, Toshio; Satake, Honoo; Minakata, Hiroyuki

2006-01-01

GnRH (gonadotropin-releasing hormone) plays a pivotal role in the regulation of reproduction in vertebrates through interaction with a specific receptor. Previously, we isolated a GnRH homo-logue, oct-GnRH, from the common octopus (Octopus vulgaris). In the present study, we have identified a GnRH receptor (oct-GnRHR) specific for oct-GnRH from Octopus brain. Oct-GnRHR includes domains and motifs typical of vertebrate GnRH receptors. The intron-inserted positions are conserved between oct-GnR...

Rats Born to Mothers Treated with Dexamethasone 15 cH Present Changes in Modulation of Inflammatory Process

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Leoni V. Bonamin

2012-01-01

Full Text Available As little information about the effect of ultra high dilutions of glucocorticoid in reproduction is available in the literature, pregnant female Wistar rats (N=12 were blindly subcutaneously treated during all gestational and lactation period with: dexamethasone 4 mg/kg diluted into dexamethasone 15 cH (mixed; or dexamethasone 4 mg/kg diluted in water; or dexamethasone 15 cH, or vehicle. Parental generation had body weight, food and water consumption monitored. The F1 generation was monitored regarding to newborn development. No birth occurred in both groups treated with dexamethasone 4 mg/kg. After 60 days from birth, 12 male F1 rats were randomly selected from each remaining group and inoculated subcutaneously with 1% carrageenan into the footpad, for evaluation of inflammatory performance. Edema and histopathology of the footpad were evaluated, using specific staining methods, immunohistochemistry and digital histomorphometry. Mothers treated with mixed dexamethasone presented reduced water consumption. F1 rats born to dexamethasone 15 cH treated females presented significant increase in mast cell degranulation, decrease in monocyte percentage, increase in CD18+ PMN cells, and early expression of ED2 protein, in relation to control. The results show that the exposure of parental generation to highly diluted dexamethasone interferes in inflammation modulation in the F1 generation.

Ultradian hormone stimulation induces glucocorticoid receptor-mediated pulses of gene transcription.

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Stavreva, Diana A; Wiench, Malgorzata; John, Sam; Conway-Campbell, Becky L; McKenna, Mervyn A; Pooley, John R; Johnson, Thomas A; Voss, Ty C; Lightman, Stafford L; Hager, Gordon L

2009-09-01

Studies on glucocorticoid receptor (GR) action typically assess gene responses by long-term stimulation with synthetic hormones. As corticosteroids are released from adrenal glands in a circadian and high-frequency (ultradian) mode, such treatments may not provide an accurate assessment of physiological hormone action. Here we demonstrate that ultradian hormone stimulation induces cyclic GR-mediated transcriptional regulation, or gene pulsing, both in cultured cells and in animal models. Equilibrium receptor-occupancy of regulatory elements precisely tracks the ligand pulses. Nascent RNA transcripts from GR-regulated genes are released in distinct quanta, demonstrating a profound difference between the transcriptional programs induced by ultradian and constant stimulation. Gene pulsing is driven by rapid GR exchange with response elements and by GR recycling through the chaperone machinery, which promotes GR activation and reactivation in response to the ultradian hormone release, thus coupling promoter activity to the naturally occurring fluctuations in hormone levels. The GR signalling pathway has been optimized for a prompt and timely response to fluctuations in hormone levels, indicating that biologically accurate regulation of gene targets by GR requires an ultradian mode of hormone stimulation.

SIRT1 Regulates Thyroid-Stimulating Hormone Release by Enhancing PIP5Kgamma Activity through Deacetylation of Specific Lysine Residues in Mammals.

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Sayaka Akieda-Asai

Full Text Available BACKGROUND: SIRT1, a NAD-dependent deacetylase, has diverse roles in a variety of organs such as regulation of endocrine function and metabolism. However, it remains to be addressed how it regulates hormone release there. METHODOLOGY/PRINCIPAL FINDINGS: Here, we report that SIRT1 is abundantly expressed in pituitary thyrotropes and regulates thyroid hormone secretion. Manipulation of SIRT1 level revealed that SIRT1 positively regulated the exocytosis of TSH-containing granules. Using LC/MS-based interactomics, phosphatidylinositol-4-phosphate 5-kinase (PIP5Kgamma was identified as a SIRT1 binding partner and deacetylation substrate. SIRT1 deacetylated two specific lysine residues (K265/K268 in PIP5Kgamma and enhanced PIP5Kgamma enzyme activity. SIRT1-mediated TSH secretion was abolished by PIP5Kgamma knockdown. SIRT1 knockdown decreased the levels of deacetylated PIP5Kgamma, PI(4,5P(2, and reduced the secretion of TSH from pituitary cells. These results were also observed in SIRT1-knockout mice. CONCLUSIONS/SIGNIFICANCE: Our findings indicated that the control of TSH release by the SIRT1-PIP5Kgamma pathway is important for regulating the metabolism of the whole body.

Aprepitant, granisetron, and dexamethasone versus palonosetron and dexamethasone for prophylaxis of cisplatin-induced nausea and vomiting in patients with upper gastrointestinal cancer: a randomized crossover phase II trial (KDOG 1002).

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Ishido, Kenji; Higuchi, Katsuhiko; Azuma, Mizutomo; Sasaki, Tohru; Tanabe, Satoshi; Katada, Chikatoshi; Yano, Takafumi; Wada, Takuya; Koizumi, Wasaburo

2016-10-01

We conducted a randomized trial to compare the safety and effectiveness of aprepitant, granisetron, and dexamethasone (AGD) with those of palonosetron and dexamethasone (PD) in patients who received highly emetogenic chemotherapy (HEC). Patients with esophageal or gastric cancer who were scheduled to receive HEC including at least 60 mg/m of cisplatin as the first-line treatment were randomly assigned to receive AGD (oral aprepitant 125 mg on day 1 and 80 mg on days 2-3; intravenous granisetron 3 mg on day 1; intravenous dexamethasone 6.6 mg on day 1 and oral dexamethasone 4 mg on days 2-3) or PD (intravenous palonosetron 0.75 mg on day 1; intravenous dexamethasone 13.2 mg on day 1 and oral dexamethasone 8 mg on days 2-3). The primary endpoint was a complete response during the overall study period (0-120 h after the start of chemotherapy) in the first cycle. Eighty-five patients were enrolled, and 84 were eligible. The complete response rate did not differ between the treatment groups, but the proportion of patients with no vomiting was significantly higher in the AGD group than in the PD group (81.4 vs. 58.5%; P=0.031). The results of a quality-of-life survey indicated that the proportion of patients with no or minimal impact on daily life in the vomiting domain was significantly higher in the AGD group (79.1 vs. 53.7%; P=0.020). The primary endpoint of complete response was not achieved, but AGD seems to be more effective than PD for the prevention of HEC-induced vomiting.

[Common physicochemical characteristics of endogenous hormones-- liberins and statins].

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Zamiatnin, A A; Voronina, O L

1998-01-01

The common chemical features of oligopeptide releasing-hormones and release inhibiting hormones were investigated with the aid of computer methods. 339 regulatory molecules of such type have been extracted out of data from computer bank EROP-Moscow. They contain from 2 to 47 amino acid residues and their sequences include short sites, which play apparently a decisive role in realization of interactions with the receptors. The analysis of chemical radicals shows that all liberins and statins contain positively charged group and cyclic radical of some amino acids or hydrophobic group. Results of this study indicate that the most chemical radicals of hormones are open for the interaction with potential receptors of target-cells. The mechanism of hormone ligand and receptors binding and conceivable role of amino acid and neurotransmitter radicals in hormonal properties of liberins and statins is discussed.

Hormonal influences on growth of the fetal pig

International Nuclear Information System (INIS)

Spencer, G.S.

1986-01-01

Although there is considerable information on hormonal systems regulating growth postnatally, little is known about hormonal influences on growth in the fetuw. It has long been postulated that insulin is the major fetal growth promoting hormone. However, chronic administration of insulin to the fetal pig during 14 days in utero, although producing hyperinsulinaemia and elevated somatomedin levels, did not stimulate an increase in length, weight or cell number. Postnatally the principal growth promoting hormones are the growth hormone dependent somatomedins. It is thought that multiplication stimulating activity (MSA) is the fetal somatomedin. However, under similar conditions to those used for insulin administration, MSA did not affect growth in the fetal pig. Administration of somatostatin to chronically catheterized fetuses inhibited (p≤0.01) and thyrotrophin releasing factor stimulated (≤0.01) GH release. However, chronic administration of SRIF did not inhibit fetal growth. Thus there does seem to be some hypothalamic control over GH secretion but this may not play a major role in regulating fetal growth

Bilateral Intravitreal Dexamethasone Implant for Retinitis Pigmentosa-Related Macular Edema

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Ali Osman Saatci

2013-03-01

Full Text Available Purpose: To report the efficacy of intravitreal dexamethasone implant in a patient with retinitis pigmentosa and bilateral cystoid macular edema unresponsive to topical carbonic anhydrase inhibitors. Case Report: A 36-year-old man with bilateral cystoid macular edema associated with retinitis pigmentosa that was unresponsive to topical carbonic anhydrase inhibitors underwent bilateral 0.7-mg intravitreal dexamethasone implants two weeks apart. Spectral domain optical coherence tomography revealed resolution of macular edema one week following each injection in both eyes and his visual acuity improved. However, macular edema recurred two months later in OS and three months later in OD. Second implant was considered for both eyes. No implant-related complication was experienced during the follow-up of seven months. Conclusion: Inflammatory process seems to play a role in retinitis pigmentosa. Intravitreal dexamethasone implant may offer retina specialists a therapeutic option especially in cases unresponsive to other treatment regimens in eyes with retinitis pigmentosa-related macular edema.

Human fear acquisition deficits in relation to genetic variants of the corticotropin releasing hormone receptor 1 and the serotonin transporter.

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Ivo Heitland

Full Text Available The ability to identify predictors of aversive events allows organisms to appropriately respond to these events, and failure to acquire these fear contingencies can lead to maladaptive contextual anxiety. Recently, preclinical studies demonstrated that the corticotropin-releasing factor and serotonin systems are interactively involved in adaptive fear acquisition. Here, 150 healthy medication-free human subjects completed a cue and context fear conditioning procedure in a virtual reality environment. Fear potentiation of the eyeblink startle reflex (FPS was measured to assess both uninstructed fear acquisition and instructed fear expression. All participants were genotyped for polymorphisms located within regulatory regions of the corticotropin releasing hormone receptor 1 (CRHR1 - rs878886 and the serotonin transporter (5HTTLPR. These polymorphisms have previously been linked to panic disorder and anxious symptomology and personality, respectively. G-allele carriers of CRHR1 (rs878886 showed no acquisition of fear conditioned responses (FPS to the threat cue in the uninstructed phase, whereas fear acquisition was present in C/C homozygotes. Moreover, carrying the risk alleles of both rs878886 (G-allele and 5HTTLPR (short allele was associated with increased FPS to the threat context during this phase. After explicit instructions regarding the threat contingency were given, the cue FPS and context FPS normalized in all genotype groups. The present results indicate that genetic variability in the corticotropin-releasing hormone receptor 1, especially in interaction with the 5HTTLPR, is involved in the acquisition of fear in humans. This translates prior animal findings to the human realm.

Contribution to the study of TRH (thyrotropin-releasing hormone) conformation using circular dichroism. Physico-chemical studies, radioactive labelling and biological applications

International Nuclear Information System (INIS)

Pradelles, Philippe.

1977-01-01

In an attempt to reach a better understanding at the molecular level of phenomena connected with the action of TRF the conformation and radioactive labelling of this hormone were investigated. The specific detection of a hormone at its action site is only possible if labelled substances of very high specific activity are used. TRF was tritium labelled by three methods: direct catalytic exchange; catalytic dehalogenation of mono- and di-iodo TRF; catalytic denitrogenation of mono-azo-TRF. Whatever the method used the tritiated TRF has a very high specific activity and keeps all its biological properties. Biological activity measurements carried out on labelled TRF, in vivo in rats and in vitro on a TRF-sensitive prolactine cell clone, are described. TRF tritiated by the above methods is shown to have the same biological activity as standard TRF. Some results are given concerning the application of labelled TRF to research on the hormone action mechanism. The tritiated TRF distribution kinetics were examined in vivo and in vitro. The kinetics of hormone fixation on the antehypophysary tissue match those of in vivo release of the plasma thyreotropic hormone, confirming the relationships between the hormone fixation on its target tissue and its biological effect. Finally an outline is given of work on the interaction of tritiated TRF with prolactine cell receptors and on the penetration of intact tritiated TRF into these cells. In addition the radioimmunological analysis of TRF was developed by the use of 125 I-mono-iodo-TRF at high specific activity (above 2000 Ci/mmole) [fr

Involvement of hormones in olfactory imprinting and homing in chum salmon.

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Ueda, Hiroshi; Nakamura, Shingo; Nakamura, Taro; Inada, Kaoru; Okubo, Takashi; Furukawa, Naohiro; Murakami, Reiichi; Tsuchida, Shigeo; Zohar, Yonathan; Konno, Kotaro; Watanabe, Masahiko

2016-02-16

The olfactory hypothesis for salmon imprinting and homing to their natal stream is well known, but the endocrine hormonal control mechanisms of olfactory memory formation in juveniles and retrieval in adults remain unclear. In brains of hatchery-reared underyearling juvenile chum salmon (Oncorhynchus keta), thyrotropin-releasing hormone gene expression increased immediately after release from a hatchery into the natal stream, and the expression of the essential NR1 subunit of the N-methyl-D-aspartate receptor increased during downstream migration. Gene expression of salmon gonadotropin-releasing hormone (sGnRH) and NR1 increased in the adult chum salmon brain during homing from the Bering Sea to the natal hatchery. Thyroid hormone treatment in juveniles enhanced NR1 gene activation, and GnRHa treatment in adults improved stream odour discrimination. Olfactory memory formation during juvenile downstream migration and retrieval during adult homing migration of chum salmon might be controlled by endocrine hormones and could be clarified using NR1 as a molecular marker.

Gonadotropin-Releasing Hormone Modulates Vomeronasal Neuron Response to Male Salamander Pheromone

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Celeste R. Wirsig-Wiechmann

2012-01-01

Full Text Available Electrophysiological studies have shown that gonadotropin-releasing hormone (GnRH modifies chemosensory neurons responses to odors. We have previously demonstrated that male Plethodon shermani pheromone stimulates vomeronasal neurons in the female conspecific. In the present study we used agmatine uptake as a relative measure of the effects of GnRH on this pheromone-induced neural activation of vomeronasal neurons. Whole male pheromone extract containing 3 millimolar agmatine with or without 10 micromolar GnRH was applied to the nasolabial groove of female salamanders for 45 minutes. Immunocytochemical procedures were conducted to visualize and quantify relative agmatine uptake as measured by labeling density of activated vomeronasal neurons. The relative number of labeled neurons did not differ between the two groups: pheromone alone or pheromone-GnRH. However, vomeronasal neurons exposed to pheromone-GnRH collectively demonstrated higher labeling intensity, as a percentage above background (75% as compared with neurons exposed to pheromone alone (63%, P < 0.018. Since the labeling intensity of agmatine within neurons signifies the relative activity levels of the neurons, these results suggest that GnRH increases the response of female vomeronasal neurons to male pheromone.

Corticotropin-releasing hormone and mast cells in the regulation of mucosal barrier function in the human colon.

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Wallon, Conny; Söderholm, Johan D

2009-05-01

Corticotropin-releasing hormone (CRH) is an important neuro-endocrine mediator of the stress response. Local effects of CRH in the intestinal mucosa have become evident in recent years. We showed that CRH activates CRH receptor subtypes R1 and R2 on subepithelial mast cells, thereby inducing increased transcellular uptake of protein antigens in human colonic biopsies in Ussing chambers. Ongoing studies also implicate local cholinergic signaling in regulation of macromolecular permeability in the human colon. Since increased uptake of antigenic molecules is associated with mucosal inflammation, our findings may have implications for understanding stress-related intestinal disorders.

Gonadotropin-Releasing Hormone Regulates Expression of the DNA Damage Repair Gene, Fanconi anemia A, in Pituitary Gonadotroph Cells1

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Larder, Rachel; Chang, Lynda; Clinton, Michael; Brown, Pamela

2007-01-01

Gonadal function is critically dependant on regulated secretion of the gonadotropin hormones from anterior pituitary gonadotroph cells. Gonadotropin biosynthesis and release is triggered by the binding of hypothalamic GnRH to GnRH receptor expressed on the gonadotroph cell surface. The repertoire of regulatory molecules involved in this process are still being defined. We used the mouse LβT2 gonadotroph cell line, which expresses both gonadotropin hormones, as a model to investigate GnRH regulation of gene expression and differential display reverse transcription-polymerase chain reaction (RT-PCR) to identify and isolate hormonally induced changes. This approach identified Fanconi anemia a (Fanca), a gene implicated in DNA damage repair, as a differentially expressed transcript. Mutations in Fanca account for the majority of cases of Fanconi anemia (FA), a recessively inherited disease identified by congenital defects, bone marrow failure, infertility, and cancer susceptibility. We confirmed expression and hormonal regulation of Fanca mRNA by quantitative RT-PCR, which showed that GnRH induced a rapid, transient increase in Fanca mRNA. Fanca protein was also acutely upregulated after GnRH treatment of LβT2 cells. In addition, Fanca gene expression was confined to mature pituitary gonadotrophs and adult mouse pituitary and was not expressed in the immature αT3-1 gonadotroph cell line. Thus, this study extends the expression profile of Fanca into a highly specialized endocrine cell and demonstrates hormonal regulation of expression of the Fanca locus. We suggest that this regulatory mechanism may have a crucial role in the GnRH-response mechanism of mature gonadotrophs and perhaps the etiology of FA. PMID:15128600

Plasma growth hormone response to human growth hormone releasing factor in rats administered with chlorpromazine and antiserum against somatostatin. Effects of hypo- and hyperthyroidism.

Science.gov (United States)

Wakabayashi, I; Tonegawa, Y; Ihara, T; Hattori, M; Shibasaki, T; Ling, N

1985-10-01

The effect of hypo- and hyperthyroidism on the plasma growth hormone (GH) response to synthetic human growth hormone releasing factor (GRF) was determined in conscious, freely moving rats pretreated with chlorpromazine and antiserum against somatostatin. Chlorpromazine plus somatostatin antiserum pretreated rats gave consistent response to GRF which was not observed in untreated rats. Chlorpromazine alone has no effect on GH secretion induced by GRF in rat pituitary monolayer culture. In rats made hypothyroid by thyroidectomy, both basal and peak plasma GH responses to a small (0.25 microgram/kg bw) and a moderate dose of GRF (1 microgram/kg bw) were significantly reduced as compared to controls. In rats made hyperthyroid by the administration of thyroxine, basal and peak plasma GH responses to a small but not to a moderate dose of GRF were significantly reduced as compared to controls. A reduced plasma GH response to a small dose of GRF was observed 8 days after the cessation of thyroxine administration. The pituitary GH reserve was markedly reduced in hypothyroid but not in hyperthyroid rats as compared to their respective controls. These results indicate that plasma GH response to GRF is reduced both in hypo- and hyperthyroidism. The mechanism involved in the phenomenon appears to be different between the two conditions.

Dexamethasone-(C21-phosphoramide)-[anti-EGFR]: molecular design, synthetic organic chemistry reactions, and antineoplastic cytotoxic potency against pulmonary adenocarcinoma (A549).

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Coyne, Cody P; Narayanan, Lakshmi

2016-01-01

Corticosteroids are effective in the management of a variety of disease states, such as several forms of neoplasia (leukemia and lymphoma), autoimmune conditions, and severe inflammatory responses. Molecular strategies that selectively "target" delivery of corticosteroids minimize or prevents large amounts of the pharmaceutical moiety from passively diffusing into normal healthy cell populations residing within tissues and organ systems. The covalent immunopharmaceutical, dexamethasone-(C21-phosphoramide)-[anti-EGFR] was synthesized by reacting dexamethasone-21-monophosphate with a carbodiimide reagent to form a dexamethasone phosphate carbodiimide ester that was subsequently reacted with imidazole to create an amine-reactive dexamethasone-(C21-phosphorylimidazolide) intermediate. Monoclonal anti-EGFR immunoglobulin was combined with the amine-reactive dexamethasone-(C21-phosphorylimidazolide) intermediate, resulting in the synthesis of the covalent immunopharmaceutical, dexamethasone-(C21-phosphoramide)-[anti-EGFR]. Following spectrophotometric analysis and validation of retained epidermal growth factor receptor type 1 (EGFR)-binding avidity by cell-ELISA, the selective anti-neoplasic cytotoxic potency of dexamethasone-(C21-phosphoramide)-[anti-EGFR] was established by MTT-based vitality stain methodology using adherent monolayer populations of human pulmonary adenocarcinoma (A549) known to overexpress the tropic membrane receptors EGFR and insulin-like growth factor receptor type 1. The dexamethasone:IgG molar-incorporation-index for dexamethasone-(C21-phosphoramide)-[anti-EGFR] was 6.95:1 following exhaustive serial microfiltration. Cytotoxicity analysis: covalent bonding of dexamethasone to monoclonal anti-EGFR immunoglobulin did not significantly modify the ex vivo antineoplastic cytotoxicity of dexamethasone against pulmonary adenocarcinoma at and between the standardized dexamethasone equivalent concentrations of 10(-9) M and 10(-5) M. Rapid increases in

Effects of an Antagonistic Analog of Growth Hormone-Releasing Hormone on Endometriosis in a Mouse Model and In Vitro.

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Köster, Frank; Jin, Li; Shen, Yuanming; Schally, Andrew V; Cai, Ren-Zhi; Block, Norman L; Hornung, Daniela; Marschner, Gabriele; Rody, Achim; Engel, Jörg B; Finas, Dominique

2017-11-01

Endometriosis is a benign gynecologic disorder causing dysmenorrhea, pelvic pain, and subfertility. Receptors for the growth hormone-releasing hormone (GHRH) were found in endometriotic tissues. Antagonists of GHRH have been used to inhibit the growth of endometriotic endometrial stromal cells. In this study, the GHRH receptor splice variant (SV) 1 was detected in human endometrial tissue samples by Western blots and quantitative reverse transcription polymerase chain reaction (qRT-PCR). The highest messenger RNA (mRNA) and protein levels of SV1 were found in eutopic endometrium from patients with endometriosis compared to ectopic endometriotic tissues and endometrium from normal patients. The highest expression for GHRH mRNA was found by qRT-PCR in ectopic endometriosis lesions. In an in vivo mouse model with human endometrial explants from patients with endometriosis, 10 μg MIA-602 per day resulted in significantly smaller human endometrial xenotransplants after 4 weeks compared to mice treated with vehicle. The endometrial tissues expressed SV1 before and after xenotransplantation. The proliferation of endometrial stromal cells as well as the endometriosis cell lines 12-Z and 49-Z was decreased by exposure to 1 μM MIA-602 after 72 hours. The protein levels of epithelial growth factor receptors in 12-Z and 49-Z cell lines were reduced 48 and 72 hours after the administration of 1 μM MIA-602. MIA-602 decreased the activation of the MAP-kinases ERK-1/2. Our study demonstrates the presence of SV1 receptor as a target for treatment with GHRH antagonist in endometriosis. Endometrial tissues respond to MIA-602 with inhibition of proliferation in vitro and in vivo. The use of MIA-602 could be an effective supplement to the treatment strategies in endometriosis.

Emotional exhaustion and overcommitment to work are differentially associated with hypothalamus-pituitary-adrenal (HPA) axis responses to a low-dose ACTH1-24 (Synacthen) and dexamethasone-CRH test in healthy school teachers.

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Wolfram, Maren; Bellingrath, Silja; Feuerhahn, Nicolas; Kudielka, Brigitte M

2013-01-01

Evidence for a detrimental impact of chronic work stress on health has accumulated in epidemiological research. Recent studies indicate altered hypothalamus-pituitary-adrenal (HPA) axis regulation as a possible biological pathway underlying the link between stress and disease. However, the direction of dysregulation remains unclear, with reported HPA hyper- or hyporeactivity. To disentangle potential effects on different functional levels in the HPA axis, we examined responses using two pharmacological stimulation tests in 53 healthy teachers (31 females, 22 males; mean age: 49.3 years; age range: 30-64 years): a low-dose adrenocorticotrophic hormone (ACTH(1-24), Synacthen) test was used to assess adrenal cortex sensitivity and the combined dexamethasone-corticotropin releasing hormone (DEX-CRH) test to examine pituitary and adrenal cortex reactivity. Blood and saliva samples were collected at - 1,+15,+30,+45,+60,+90,+120 min. Emotional exhaustion (EE), the core dimension of burnout, was measured with the Maslach Burnout Inventory. Overcommitment (OC) was assessed according to Siegrist's effort-reward-imbalance model. We found a significant association between EE and higher plasma cortisol profiles after Synacthen (p = 0.045). By contrast, OC was significantly associated with attenuated ACTH (p = 0.045), plasma cortisol (p = 0.005), and salivary cortisol (p = 0.023) concentrations following DEX-CRH. Results support the notion of altered HPA axis regulation in chronically work-stressed teachers, with differential patterns of hyper- and hyporeactivity depending on individual stress condition and the tested functional level of the HPA axis.

Contralateral eye-to-eye comparison of intravitreal ranibizumab and a sustained-release dexamethasone intravitreal implant in recalcitrant diabetic macular edema

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Thomas BJ

2016-08-01

Full Text Available Benjamin J Thomas, Yoshihiro Yonekawa, Jeremy D Wolfe, Tarek S Hassan Department of Vitreoretinal Surgery, William Beaumont Hospital, Royal Oak, MI, USA Objective: To compare the effects of intravitreal ranibizumab (RZB or dexamethasone (DEX intravitreal implant in cases of recalcitrant diabetic macular edema (DME.Methods: Retrospective, interventional study examining patients with symmetric bilateral, center-involved DME recalcitrant to treatment with RZB, who received DEX in one eye while the contralateral eye continued to receive RZB every 4–5 weeks for a study period of 3 months.Results: Eleven patients (22 eyes were included: mean logarithm of the minimal angle of resolution (logMAR visual acuity (VA for the DEX arm improved from 0.415 (standard deviation [SD] ±0.16 to 0.261 (SD ±0.18 at final evaluation, and mean central macular thickness (CMT improved from 461 µm (SD ±156 to 356 µm (SD ±110; net decrease: 105 µm, P=0.01. Mean logMAR VA for the RZB arm improved from 0.394 (SD ±0.31 to 0.269 (SD ±0.19 at final evaluation. Mean CMT improved from 421 µm (SD ±147 to 373 µm (SD ±129; net decrease: 48 µm, P=0.26.Conclusion: A subset of recalcitrant DME patients demonstrated significant CMT reduction and VA improvement after a single DEX injection. Keywords: aflibercept, bevacizumab, central macular thickness, macular edema, dexamethasone implant, diabetic macular edema, diabetic retinopathy, ranibizumab

Loss of hypothalamic corticotropin-releasing hormone markedly reduces anxiety behaviors in mice

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Zhang, Rong; Asai, Masato; Mahoney, Carrie E; Joachim, Maria; Shen, Yuan; Gunner, Georgia; Majzoub, Joseph A

2016-01-01

A long-standing paradigm posits that hypothalamic corticotropin-releasing hormone (CRH) regulates neuroendocrine functions such as adrenal glucocorticoid release, while extra-hypothalamic CRH plays a key role in stressor-triggered behaviors. Here we report that hypothalamus-specific Crh knockout mice (Sim1CrhKO mice, created by crossing Crhflox with Sim1Cre mice) have absent Crh mRNA and peptide mainly in the paraventricular nucleus of the hypothalamus (PVH) but preserved Crh expression in other brain regions including amygdala and cerebral cortex. As expected, Sim1CrhKO mice exhibit adrenal atrophy as well as decreased basal, diurnal and stressor-stimulated plasma corticosterone secretion and basal plasma ACTH, but surprisingly, have a profound anxiolytic phenotype when evaluated using multiple stressors including open field, elevated plus maze, holeboard, light-dark box, and novel object recognition task. Restoring plasma corticosterone did not reverse the anxiolytic phenotype of Sim1CrhKO mice. Crh-Cre driver mice revealed that PVHCrh fibers project abundantly to cingulate cortex and the nucleus accumbens shell, and moderately to medial amygdala, locus coeruleus, and solitary tract, consistent with the existence of PVHCrh-dependent behavioral pathways. Although previous, nonselective attenuation of CRH production or action, genetically in mice and pharmacologically in humans, respectively, has not produced the anticipated anxiolytic effects, our data show that targeted interference specifically with hypothalamic Crh expression results in anxiolysis. Our data identify neurons that express both Sim1 and Crh as a cellular entry point into the study of CRH-mediated, anxiety-like behaviors and their therapeutic attenuation. PMID:27595593

The role of adjunctive dexamethasone in the treatment of bacterial meningitis: an updated systematic meta-analysis

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Shao M

2016-07-01

Full Text Available Mei Shao,1 Peng Xu,2 Jun Liu,3 Wenyun Liu,1 Xiujie Wu1 1Department of Neurosurgery, Linyi People’s Hospital, 2Department of Neurosurgery, Linyi Yishui Central Hospital, Linyi, 3Department of Neurosurgery, Binzhou Medical College, Yantai, Shandong, People’s Republic of China Background: Bacterial meningitis is a serious infection in children and adults worldwide, with considerable morbidity, mortality, and severe neurological sequelae. Dexamethasone is often used before antibiotics in cases of this disease, and improves outcomes.Objective: Although several studies have identified the role of adjunctive dexamethasone therapy in the treatment of bacterial meningitis, the results are still inconclusive. The aim of this study was to systematically evaluate the therapeutic and adverse effect of adjunctive dexa­methasone in patients with bacterial meningitis.Materials and methods: Relevant randomized, double-blind, placebo-controlled trials of dexamethasone in bacterial meningitis published between 2000 and 2016 were retrieved from the common electronic databases. The odds ratio (OR and risk ratio (RR with their 95% confidence interval (CI were employed to calculate the effect.Results: A total of ten articles including 2,459 bacterial meningitis patients (1,245 in the dexamethasone group and 1,214 in the placebo group were included in this meta-analysis. Our result found that dexamethasone was not associated with a significant reduction in follow-up mortality (292 of 1,245 on dexamethasone versus 314 of 1,214 on placebo; OR =0.91, 95% CI =0.80–1.03, P=0.14 and severe neurological sequelae (22.4% versus 24.1%, OR =0.84, 95% CI =0.54–1.29, P=0.42. However, dexamethasone seemed to reduce hearing loss among survivors (21.2% versus 26.1%; OR =0.76, 95% CI =0.59–0.98, P=0.03. No significant difference was found between these two groups in adverse events.Conclusion: Our results suggested that adjunctive dexamethasone might not be beneficial in the

Effects of adrenal hormones on the expression of adiponectin and adiponectin receptors in adipose tissue, muscle and liver.

Science.gov (United States)

de Oliveira, Cristiane; Iwanaga-Carvalho, Carla; Mota, João F; Oyama, Lila M; Ribeiro, Eliane B; Oller do Nascimento, Cláudia M

2011-11-01

Adiponectin, an insulin-sensitive hormone that is primarily synthesized in adipose tissue, exerts its effects by binding to two receptors, adipoR1 and adipoR2. Little is known regarding the effects of glucocorticoids on the expression of adiponectin receptors. Male Wistar rats were bilaterally adrenalectomized and treated with dexamethasone (0.2 mg/100 g) twice daily for 3 days. To analyze the potential effects of glucocorticoids, rats received two daily injections of the glucocorticoid receptor antagonist (RU-486, 5.0 mg) over the course of 3 days. Additionally, 3T3-L1 adipocytes and C2C12 myotubes were treated with dexamethasone, adrenaline or RU-486. The gene expression of adiponectin, adipoR1 and adipoR2 was determined by real-time PCR, and protein secretion was examined by Western blotting using lysates from retroperitoneal, epididymal and subcutaneous adipose tissue depots, liver and muscle. In rats, excess glucocorticoids increased the levels of insulin in serum and decreased serum adiponectin concentrations, whereas adrenalectomy decreased the mRNA expression of adiponectin (3-fold) and adipoR2 (7-fold) in epididymal adipose tissue and increased adipoR2 gene expression in muscle (3-fold) compared to control group sham-operated. Dexamethasone treatment did not reverse the effects of adrenalectomy, and glucocorticoid receptor blockade did not reproduce the effects of adrenalectomy. In 3T3-L1 adipocytes, dexamethasone and adrenaline both increased adipoR2 mRNA levels, but RU-486 reduced adipoR2 gene expression in vitro. Dexamethasone treatment induces a state of insulin resistance but does not affect adiponectin receptor expression in adipose tissue. However, the effects of catecholamines on insulin resistance may be due to their effects on adipoR2. Copyright © 2011 Elsevier Inc. All rights reserved.

An oral multi-particulate, modified release, hydrocortisone replacement therapy that provides physiological cortisol exposure

Science.gov (United States)

Huatan, Hiep; Merke, Deborah; Arlt, Wiebke; Ross, Richard J.

2013-01-01

Objective It is not possible with current hydrocortisone replacement to mimic the diurnal cortisol profile in patients with adrenal insufficiency. Previous attempts with modified release technology were unsuccessful. Our objective was to develop hydrocortisone formulations that recreate the diurnal cortisol profile using multi-particulate technology. Design and Measurements Screening by in-vitro dissolution profiles, pharmacokinetic testing in dexamethasone suppressed dogs and humans, and comparison to a reference population. Setting Field laboratories and clinical research facility. Results Formulations were generated using an enteric (delayed-release) design configuration with an extended (sustained-release) dissolution profile. In-vitro dissolution confirmed delayed and sustained hydrocortisone release. However, in dogs and humans, sustained release resulted in reduced bioavailability. A formulation, DIURF-006, was developed that maintained delayed release but omitted the sustained release functionality. Pharmacokinetic characterisation of DIURF-006 showed that, despite absence of a sustained release component, absorption was sufficiently sustained to deliver extended hydrocortisone absorption. In dexamethasone-suppressed volunteers (n=16) receiving a twice daily ‘toothbrush’ regimen (20mg at 23:00h and 10mg at 07:00h), DIURF-006 gave a similar cortisol profile to physiological cortisol levels: DIURF-006 vs physiological, Geomean AUC 5610 vs 4706 hr*nmol/l, Geomean Cmax 665 vs 594 nmol/l and Median Tmax 8.5h vs clock time 08:12 hours for peak cortisol. The relative bioavailability of DIURF-006 vs hydrocortisone was 89% and cortisol levels increased linearly with doses between 5 and 30mg. Conclusion A multi-particulate oral hydrocortisone formulation with only an enteric coat provides delayed and sustained absorption and when given in a ‘toothbrush’ regimen provides physiological cortisol exposure. PMID:23980724

Altered calcium handling and increased contraction force in human embryonic stem cell derived cardiomyocytes following short term dexamethasone exposure

Energy Technology Data Exchange (ETDEWEB)

Kosmidis, Georgios; Bellin, Milena; Ribeiro, Marcelo C.; Meer, Berend van; Ward-van Oostwaard, Dorien [Department of Anatomy and Embryology, Leiden University Medical Center, Leiden (Netherlands); Passier, Robert [Department of Anatomy and Embryology, Leiden University Medical Center, Leiden (Netherlands); MIRA, University of Twente (Netherlands); Tertoolen, Leon G.J.; Mummery, Christine L. [Department of Anatomy and Embryology, Leiden University Medical Center, Leiden (Netherlands); Casini, Simona, E-mail: s.casini@amc.uva.nl [Department of Anatomy and Embryology, Leiden University Medical Center, Leiden (Netherlands)

2015-11-27

One limitation in using human pluripotent stem cell derived cardiomyocytes (hPSC-CMs) for disease modeling and cardiac safety pharmacology is their immature functional phenotype compared with adult cardiomyocytes. Here, we report that treatment of human embryonic stem cell derived cardiomyocytes (hESC-CMs) with dexamethasone, a synthetic glucocorticoid, activated glucocorticoid signaling which in turn improved their calcium handling properties and contractility. L-type calcium current and action potential properties were not affected by dexamethasone but significantly faster calcium decay, increased forces of contraction and sarcomeric lengths, were observed in hESC-CMs after dexamethasone exposure. Activating the glucocorticoid pathway can thus contribute to mediating hPSC-CMs maturation. - Highlights: • Dexamethasone accelerates Ca{sup 2+} transient decay in hESC-CMs. • Dexamethasone enhances SERCA and NCX function in hESC-CMs. • Dexamethasone increases force of contraction and sarcomere length in hESC-CMs. • Dexamethasone does not alter I{sub Ca,L} and action potential characteristics in hESC-CMs.

Altered calcium handling and increased contraction force in human embryonic stem cell derived cardiomyocytes following short term dexamethasone exposure

International Nuclear Information System (INIS)

Kosmidis, Georgios; Bellin, Milena; Ribeiro, Marcelo C.; Meer, Berend van; Ward-van Oostwaard, Dorien; Passier, Robert; Tertoolen, Leon G.J.; Mummery, Christine L.; Casini, Simona

2015-01-01

One limitation in using human pluripotent stem cell derived cardiomyocytes (hPSC-CMs) for disease modeling and cardiac safety pharmacology is their immature functional phenotype compared with adult cardiomyocytes. Here, we report that treatment of human embryonic stem cell derived cardiomyocytes (hESC-CMs) with dexamethasone, a synthetic glucocorticoid, activated glucocorticoid signaling which in turn improved their calcium handling properties and contractility. L-type calcium current and action potential properties were not affected by dexamethasone but significantly faster calcium decay, increased forces of contraction and sarcomeric lengths, were observed in hESC-CMs after dexamethasone exposure. Activating the glucocorticoid pathway can thus contribute to mediating hPSC-CMs maturation. - Highlights: • Dexamethasone accelerates Ca"2"+ transient decay in hESC-CMs. • Dexamethasone enhances SERCA and NCX function in hESC-CMs. • Dexamethasone increases force of contraction and sarcomere length in hESC-CMs. • Dexamethasone does not alter I_C_a_,_L and action potential characteristics in hESC-CMs.

Gonadotropin-releasing hormone immunoreactivity in the adult and fetal human olfactory system.

Science.gov (United States)

Kim, K H; Patel, L; Tobet, S A; King, J C; Rubin, B S; Stopa, E G

1999-05-01

Studies in fetal brain tissue of rodents, nonhuman primates and birds have demonstrated that cells containing gonadotropin-releasing hormone (GnRH) migrate from the olfactory placode across the nasal septum into the forebrain. The purpose of this study was to examine GnRH neurons in components of the adult and fetal human olfactory system. In the adult human brain (n=4), immunoreactive GnRH was evident within diffusely scattered cell bodies and processes in the olfactory bulb, olfactory nerve, olfactory cortex, and nervus terminalis located on the anterior surface of the gyrus rectus. GnRH-immunoreactive structures showed a similar distribution in 20-week human fetal brains (n=2), indicating that the migration of GnRH neurons is complete at this time. In 10-11-week fetal brains (n=2), more cells were noted in the nasal cavity than in the brain. Our data are consistent with observations made in other species, confirming olfactory derivation and migration of GnRH neurons into the brain from the olfactory placode. Copyright 1999 Elsevier Science B.V.

Immunocytochemical localization of luteinizing hormone-releasing hormone (LHRH) in the nervus terminalis and brain of the big brown bat, Eptesicus fuscus.

Science.gov (United States)

Oelschläger, H A; Northcutt, R G

1992-01-15

Little is known about the immunohistochemistry of the nervous system in bats. This is particularly true of the nervus terminalis, which exerts strong influence on the reproductive system during ontogeny and in the adult. Luteinizing hormone-releasing hormone (LHRH) was visualized immunocytochemically in the nervus terminalis and brain of juvenile and adult big brown bats (Eptesicus fuscus). The peripheral LHRH-immunoreactive (ir) cells and fibers (nervus terminalis) are dispersed along the basal surface of the forebrain from the olfactory bulbs to the prepiriform cortex and the interpeduncular fossa. A concentration of peripheral LHRH-ir perikarya and fibers was found at the caudalmost part of the olfactory bulbs, near the medioventral forebrain sulcus; obviously these cells mediate between the bulbs and the remaining forebrain. Within the central nervous system (CNS), LHRH-ir perikarya and fibers were distributed throughout the olfactory tubercle, diagonal band, preoptic area, suprachiasmatic and supraoptic nuclei, the bed nuclei of stria terminalis and stria medullaris, the anterior lateral and posterior hypothalamus, and the tuber cinereum. The highest concentration of cells was found within the arcuate nucleus. Fibers were most concentrated within the median eminence, infundibular stalk, and the medial habenula. The data obtained suggest that this distribution of LHRH immunoreactivity may be characteristic for microchiropteran (insectivorous) bats. The strong projections of LHRH-containing nuclei in the basal forebrain (including the arcuate nucleus) to the habenula, may indicate close functional contact between these brain areas via feedback loops, which could be important for the processing of thermal and other environmental stimuli correlated with hibernation.

The stress and migraine interaction.

Science.gov (United States)

Sauro, Khara M; Becker, Werner J

2009-10-01

There are several ways in which stress may interact with migraine in those predisposed to migraine attacks. These interactions may result from biochemical changes related to the physiological stress response, as, for example, the release of corticotrophin releasing hormone, or from changes induced by the psychological response to stressors. Stress is the factor listed most often by migraine sufferers as a trigger for their attacks, but in addition there is evidence that stress can help initiate migraine in those predisposed to the disorder, and may also contribute to migraine chronification. Migraine attacks themselves can act as a stressor, thereby potentially leading to a vicious circle of increasing migraine frequency. Since the important factor in the stress-migraine interaction is likely the individual's responses to stressors, rather than the stressors themselves, the acquisition of effective stress management skills has the potential to reduce the impact of stressors on those with migraine.

Animal manure separation technologies diminish the environmental burden of steroid hormones

DEFF Research Database (Denmark)

Hansen, Martin; Björklund, Erland; Popovic, Olga

2015-01-01

environmental risks associated with the release of steroid hormones to adjacent waterways. To assess the potential benefit of these technologies in reducing the level of release of steroid hormones to adjacent waterways, distribution profiles of nine steroid hormones (pregnenolone, progesterone......Newly developed treatment technologies are capable of separating livestock manure into a liquid fraction and a solid fraction using sedimentation, mechanical, and/or chemical methods. These technologies offer a potential means of distributing nutrients to agricultural lands without the unwanted...

Protection against dexamethasone-induced muscle atrophy is related to modulation by testosterone of FOXO1 and PGC-1{alpha}

Energy Technology Data Exchange (ETDEWEB)

Qin, Weiping, E-mail: weiping.qin@mssm.edu [Center of Excellence for the Medical Consequences of Spinal Cord Injury, James J. Peters VA Medical Center, Bronx, NY (United States); Department of Medicine, Mount Sinai School of Medicine, NY (United States); Pan, Jiangping; Wu, Yong [Center of Excellence for the Medical Consequences of Spinal Cord Injury, James J. Peters VA Medical Center, Bronx, NY (United States); Bauman, William A. [Center of Excellence for the Medical Consequences of Spinal Cord Injury, James J. Peters VA Medical Center, Bronx, NY (United States); Department of Medicine, Mount Sinai School of Medicine, NY (United States); Department of Rehabilitation Medicine, Mount Sinai School of Medicine, NY (United States); Cardozo, Christopher, E-mail: Chris.Cardozo@mssm.edu [Center of Excellence for the Medical Consequences of Spinal Cord Injury, James J. Peters VA Medical Center, Bronx, NY (United States); Department of Medicine, Mount Sinai School of Medicine, NY (United States); Department of Rehabilitation Medicine, Mount Sinai School of Medicine, NY (United States)

2010-12-17

Research highlights: {yields} In rat gastrocnemius muscle, dexamethasone reduced PGC-1{alpha} cellular and nuclear levels without altering mRNA levels for this factor. {yields} Dexamethasone reduced phosphorylating of p38 MAPK, which stabilizes PGC-1{alpha} and promotes its nuclear entry. {yields} Co-administration of testosterone with dexamethasone increased cellular and nuclear levels of PGC-1{alpha} protein without changing its mRNA levels. {yields} Co-administration of testosterone restored p38 MAPK levels to those of controls. -- Abstract: Glucocorticoid-induced muscle atrophy results from muscle protein catabolism and reduced protein synthesis, associated with increased expression of two muscle-specific ubiquitin ligases (MAFbx and MuRF1), and of two inhibitors of protein synthesis, REDD1 and 4EBP1. MAFbx, MuRF1, REDD1 and 4EBP1 are up-regulated by the transcription factors FOXO1 and FOXO3A. The transcriptional co-activator PGC-1{alpha} has been shown to attenuate many forms of muscle atrophy and to repress FOXO3A-mediated transcription of atrophy-specific genes. Dexamethasone-induced muscle atrophy can be prevented by testosterone, which blocks up-regulation by dexamethasone of FOXO1. Here, an animal model of dexamethasone-induced muscle atrophy was used to further characterize effects of testosterone to abrogate adverse actions of dexamethasone on FOXO1 levels and nuclear localization, and to determine how these agents affect PGC-1{alpha}, and its upstream activators, p38 MAPK and AMPK. In rat gastrocnemius muscle, testosterone blunted the dexamethasone-mediated increase in levels of FOXO1 mRNA, and FOXO1 total and nuclear protein. Dexamethasone reduced total and nuclear PGC-1{alpha} protein levels in the gastrocnemius; co-administration of testosterone with dexamethasone increased total and nuclear PGC-1{alpha} levels above those present in untreated controls. Testosterone blocked dexamethasone-induced decreases in activity of p38 MAPK in the gastrocnemius

Regulation of hepatic level of fatty-acid-binding protein by hormones and clofibric acid in the rat.

Science.gov (United States)

Nakagawa, S; Kawashima, Y; Hirose, A; Kozuka, H

1994-01-01

Regulation of the hepatic level of fatty-acid-binding protein (FABP) by hormones and p-chlorophenoxyisobutyric acid (clofibric acid) was studied. The hepatic level of FABP, measured as the oleic acid-binding capacity of the cytosolic FABP fraction, was decreased in streptozotocin-diabetic rats. The level of FABP was markedly increased in adrenalectomized rats, and the elevation was prevented by the administration of dexamethasone. Hypothyroidism decreased the level of FABP and hyperthyroidism increased it. A high correlation between the incorporation of [14C]oleic acid in vivo into hepatic triacylglycerol and the level of FABP was found for normal, diabetic and adrenalectomized rats. The level of FABP was increased by administration of clofibric acid to rats in any altered hormonal states, as was microsomal 1-acylglycerophosphocholine (1-acyl-GPC) acyltransferase, a peroxisome-proliferator-responsive parameter. These results suggest that the hepatic level of FABP is under regulation by multiple hormones and that clofibric acid induces FABP and 1-acyl-GPC acyltransferase by a mechanism which may be distinct from that by which hormones regulate the level of FABP. PMID:8110197

A multifunctional magnetic nanocarrier bearing fluorescent dye for targeted drug delivery by enhanced two-photon triggered release

International Nuclear Information System (INIS)

Banerjee, Shashwat S; Chen, D-H

2009-01-01

We report a novel nanoformulation for targeted drug delivery which utilizes nanophotonics through the fusion of nanotechnology with biomedical application. The approach involves an energy-transferring magnetic nanoscopic co-assembly fabricated of rhodamine B (RDB) fluorescent dye grafted gum arabic modified Fe 3 O 4 magnetic nanoparticle and photosensitive linker by which dexamethasone drug is conjugated to the magnetic nano-assembly. The advantage offered by this nanoformulation is the indirect photo-triggered-on-demand drug release by efficient up-converting energy of the near-IR (NIR) light to higher energy and intraparticle energy transfer from the dye grafted magnetic nanoparticle to the linker for drug release by cleavage. The synthesized nanoparticles were found to be of ultra-small size (13.33 nm) and are monodispersed in an aqueous suspension. Dexamethasone (Dexa) drug conjugated to RDB-GAMNP by photosensitive linker showed appreciable release of Dexa by photo-triggered response on exposure to radiation having a wavelength in the NIR region whereas no detectable release was observed in the dark. Photo-triggered response for the nanoformulation not bearing the rhodamine B dye was drastically less as less Dexa was released on exposure to NIR radiation which suggest that the photo-cleavage of linker and release of Dexa mainly originated from the indirect excitation through the uphill energy conversions based on donor-acceptor model FRET. The promising pathway of nanophotonics for the on-demand release of the drug makes this nanocarrier very promising for applications in nanomedicine.

Electrically responsive microreservoires for controllable delivery of dexamethasone in bone tissue engineering

Science.gov (United States)

Paun, Irina Alexandra; Zamfirescu, Marian; Luculescu, Catalin Romeo; Acasandrei, Adriana Maria; Mustaciosu, Cosmin Catalin; Mihailescu, Mona; Dinescu, Maria

2017-01-01

A major concern in orthopedic implants is to decrease the chronic inflammation using specific drug therapies. The newest strategies rely on the controlled delivery of antiinflammatory drugs from carrier biointerfaces designed in the shape of 3D architectures. We report on electrically responsive microreservoires (ERRs) acting as microcontainers for antiinflammatory drugs, as potential biointerfaces in orthopedic implants. The ERRs consist in arrays of vertical microtubes produced by laser direct writing using two photon polymerization effects (2PP_LDW) of a commercially available photoresist, IP-L780. A polypyrrole (conductive)/dexamethasone (drug model) (PPy/Dex) mixture was loaded into the ERRs via a simple immersion process. Then, the ERRs were sealed with a poly(lactic-co-glycolic acid)(PLGA) layer by Matrix Assisted Pulsed Laser Evaporation. ERRs stimulation using voltage cycles between -1 V and +1 V, applied at specific time intervals, at a scan rate of 0.1 V s-1, enabled to control the Dex release. The release time scales were between 150 and 275 h, while the concentrations of Dex released were between 450-460 nM after three applied voltage cycles, for different microreservoires dimensions. The proposed approach was validated in osteoblast-like MG-63 cell cultures. Cell viability and adhesion assays showed that the Dex-loaded ERRs sustained the cells growth and preserved their characteristic polygonal shape. Importantly, for the electrically-stimulated Dex release, the level of the alkaline phosphatase activity increased twice, the osteogenic differentiation surpassed by 1.6 times and the relative level of osteocalcin gene expression was 2.2 times higher as compared with the unstimulated drug release. Overall, the ERRs were able to accelerate the cells osteogenic differentiation via electrically controlled release of Dex.

Comparison of the effects of intravitreal bevacizumab and dexamethasone in experimental posterior penetrating eye injury

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Ayse Oner

2018-04-01

Full Text Available AIM: To compare the effects of intravitreal anti-vascular endothelial growth factor (VEGF and dexamethasone in an experimental rabbit model of posterior penetrating ocular injury. METHODS: Thirty white New Zealand rabbits were included in the study. A posterior penetrating ocular injury was performed at the superotemporal quadrant. They were randomly divided into three groups. The rabbits in group 1 received intravitreal dexamethasone, in group 2 they received intravitreal bevacizumab and those in group 3 received intravitreal physiological saline solution in both eyes. All eyes were examined ophthalmologically on the 1st, 3rd, 7th, 14th and 28th days following the injury and the clinical findings were scored. On the day 28, the eyes were enucleated, evaluated and scored macroscopically, histopathologically and scanning electron microscopically. RESULTS: The median clinical score on the 14th and 28th days and the median macroscopic score of the dexamethasone group was significantly better than that of control (P=0.004, 0.018. Dexamethasone group was also better than that of bevacizumab group but the differences did not reach statistical significance. Retinal detachment rate was 8.3%, 16.6% and 12.5% in the dexamethasone group, bevacizumab group and control group, respectively (P=0.476. More extensive fibrocelluler proliferations were observed in controls compared with dexamethasone and bevacizumab groups. But these differences did not reach the statistical significance (P=0.538. In scanning electron microscopy all groups showed fibreous stalk and dense collagen fibrils in vitreous. CONCLUSION: This study shows that intravitreal injection of both dexamethasone and bevacizumab may reduce the intraocular fibrous proliferation after an experimental posterior penetrating ocular injury in rabbits.

Effects of dexamethasone and pheniramine hydrogen maleate on stress response in patients undergoing elective laparoscopic cholecystectomy.

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Karaman, Kerem; Bostanci, Erdal Birol; Aksoy, Erol; Ulas, Murat; Yigit, Tuba; Erdemli, Mehmet Ozcan; Ercin, Ugur; Bilgihan, Ayse; Saydam, Gul; Akoglu, Musa

2013-02-01

Laparoscopic cholecystectomy (LC) still leads to significant postoperative nausea and vomiting (PONV) and pain. Our aim was to evaluate the efficacy of dexamethasone or pheniramine hydrogen maleate, either alone or combined, in reducing the stress response and symptoms after LC. Patients were randomly assigned to 1 of 4 groups, each consisting of 20 patients: control, dexamethasone (8 mg/2 mL), pheniramine hydrogen maleate (45.5 mg/2 mL), and the combined group. The drugs were given before anesthesia induction. C-reactive protein levels (CRP) and visual analog scale (VAS) scores were significantly less in the dexamethasone (P = .003) and combined groups (P pheniramine hydrogen maleate (P = .005) significantly reduced PONV. Dexamethasone significantly reduced postoperative pain and the systemic acute-phase response, whereas these effects were only partially attained with pheniramine hydrogen maleate. Both dexamethasone and pheniramine hydrogen maleate significantly reduced PONV. An additive effect seemed to occur if these drugs were used in combination. Copyright © 2013 Elsevier Inc. All rights reserved.

Dexamethasone-(C21-phosphoramide-[anti-EGFR]: molecular design, synthetic organic chemistry reactions, and antineoplastic cytotoxic potency against pulmonary adenocarcinoma (A549

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Coyne CP

2016-08-01

Full Text Available Cody P Coyne,1 Lakshmi Narayanan2 1Department of Basic Sciences, 2Department of Clinical Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS, USA Purpose: Corticosteroids are effective in the management of a variety of disease states, such as several forms of neoplasia (leukemia and lymphoma, autoimmune conditions, and severe inflammatory responses. Molecular strategies that selectively “target” delivery of corticosteroids minimize or prevents large amounts of the pharmaceutical moiety from passively diffusing into normal healthy cell populations residing within tissues and organ systems. Materials and methods: The covalent immunopharmaceutical, dexamethasone-(C21-phosphoramide-[anti-EGFR] was synthesized by reacting dexamethasone-21-monophosphate with a carbodiimide reagent to form a dexamethasone phosphate carbodiimide ester that was subsequently reacted with imidazole to create an amine-reactive dexamethasone-(C21-phosphorylimidazolide intermediate. Monoclonal anti-EGFR immunoglobulin was combined with the amine-reactive dexamethasone-(C21-phosphorylimidazolide intermediate, resulting in the synthesis of the covalent immunopharmaceutical, dexamethasone-(C21-phosphoramide-[anti-EGFR]. Following spectrophotometric analysis and validation of retained epidermal growth factor receptor type 1 (EGFR-binding avidity by cell-ELISA, the selective anti-neoplasic cytotoxic potency of dexamethasone-(C21-phosphoramide-[anti-EGFR] was established by MTT-based vitality stain methodology using adherent monolayer populations of human pulmonary adenocarcinoma (A549 known to overexpress the tropic membrane receptors EGFR and insulin-like growth factor receptor type 1. Results: The dexamethasone:IgG molar-incorporation-index for dexamethasone-(C21-phosphoramide-[anti-EGFR] was 6.95:1 following exhaustive serial microfiltration. Cytotoxicity analysis: covalent bonding of dexamethasone to monoclonal anti-EGFR immunoglobulin

Synthesis of dexamethasone-4-14C

International Nuclear Information System (INIS)

Rao, P.N.; Cessac, J.W.; Hill, K.A.

1982-01-01

The bismethylenedioxy (BMD) derivative of dexamethasone 2 was silylated with trimethylchlorosilane and imidazole in dimethylformamide to give the 11β-trimethylsilyloxy BMD derivative 3. The Δ 1 -double bond in 3 was hydrogenated over 5% palladium on carbon to give the Δ 4 -3-oxo steroid 4. Oxidation of 4 with potassium permanganate-sodium metaperiodate gave the seco-acid 5 which on subsequent treatment with acetic anhydride; sodium acetate and triethylamine gave the enol-lactone 6. The enol-lactone 6 was reacted with 14 C-methylmagnesium iodide to give an adduct 7a which on heating at reflux with lithium 2,6-di-t-butylphenoxide in dioxane gave the Δ 4 -3-oxo derivative 8. Compound 8 was heated at reflux with m-iodylbenzoic acid and diphenyl diselenide in toluene to give the Δsup(1,4)-3-oxo steroid 9. The protecting BMD and silyl groups were removed in a single step by reaction with aqueous trifluoroacetic acid containing 2N hydrochloric acid at room temperature to give dexamethasone-4- 14 C 10. (author)

Compatibility and stability of aloxi (palonosetron hydrochloride) admixed with dexamethasone sodium phosphate.

Science.gov (United States)

Trissel, Lawrence A; Zhang, Yanping

2004-01-01

The purpose of this study was to evaluate the physical and chemical stability of palonosetron hydrochloride 0.25 mg admixed with dexamethasone (as sodium phophate) 10 mg or 20 mg in 5% dextrose injection or 0.9% sodium chloride injection in polyvinylchloride minibags, and also admixed with dexamethasone (as sodium phosphate) 3.3 mg in 5% dextrose injection or 0.9% sodium chloride injection in polypropylene syringes, at 4 deg C stored in the dark for 14 days, and at 23 deg C exposed to normal laboratory fluorescent light over 48 hours. Test samples of palonosetron hydrochloride 5 micrograms/mL with dexamethasone (as sodium phosphate) 0.2 mg/mL and also 0.4 mg/mL were prepared in polyvinylchloride minibags of each infusion solution. Additionally, palonosetron hydrochloride 25 micrograms/mL with dexamethasone (as sodium phosphate) 0.33 mg/mL in each infusion solution were prepared as 10 mL of test solution in 20-mL polypropylene syringes. Evaluations for physical and chemical stability were performed on samples taken initially and after 1, 3, 7 and 14 days of storage at 4 deg C and after 1, 4, 24 and 48 hours at 23 deg C. Physical stability was assessed using visual observation in normal room light and using a high-intensity monodirectional light beam. In addition, turbidity and particle content were measured electronically. Chemical stability of the drug was evaluated by using a stability-indicating high-performance liquid chromatographic analytical technique. All samples were physically compatible throughout the study. The solutions remained clear and showed little or no change in particulate burden and haze level. Additionally, little or no loss of palonosetron hydrochloride and dexamethasone occurred in any of the samples at either temperature throughout the entire study period. Admixtures of palonosetron hydrochloride with dexamethasone sodium phosphate in 5% dextrose injection or in 0.9% sodium chloride injection packaged in polyvinylchloride minibags or in

Effect of a corticotropin releasing hormone receptor antagonist on colonic sensory and motor function in patients with irritable bowel syndrome

OpenAIRE

Sagami, Y; Shimada, Y; Tayama, J; Nomura, T; Satake, M; Endo, Y; Shoji, T; Karahashi, K; Hongo, M; Fukudo, S

2004-01-01

Background and aims: Corticotropin releasing hormone (CRH) is a major mediator of the stress response in the brain-gut axis. Irritable bowel syndrome (IBS) is presumed to be a disorder of the brain-gut link associated with an exaggerated response to stress. We hypothesised that peripheral administration of α-helical CRH (αhCRH), a non-selective CRH receptor antagonist, would improve gastrointestinal motility, visceral perception, and negative mood in response to gut stimulation in IBS patient...

Stressor-specific effects of sex on HPA axis hormones and activation of stress-related neurocircuitry.

Science.gov (United States)

Babb, Jessica A; Masini, Cher V; Day, Heidi E W; Campeau, Serge

2013-11-01

Experiencing stress can be physically and psychologically debilitating to an organism. Women have a higher prevalence of some stress-related mental illnesses, the reasons for which are unknown. These experiments explore differential HPA axis hormone release in male and female rats following acute stress. Female rats had a similar threshold of HPA axis hormone release following low intensity noise stress as male rats. Sex did not affect the acute release, or the return of HPA axis hormones to baseline following moderate intensity noise stress. Sensitive indices of auditory functioning obtained by modulation of the acoustic startle reflex by weak pre-pulses did not reveal any sexual dimorphism. Furthermore, male and female rats exhibited similar c-fos mRNA expression in the brain following noise stress, including several sex-influenced stress-related regions. The HPA axis response to noise stress was not affected by stage of estrous cycle, and ovariectomy significantly increased hormone release. Direct comparison of HPA axis hormone release to two different stressors in the same animals revealed that although female rats exhibit robustly higher HPA axis hormone release after restraint stress, the same effect was not observed following moderate and high intensity loud noise stress. Finally, the differential effect of sex on HPA axis responses to noise and restraint stress cannot readily be explained by differential social cues or general pain processing. These studies suggest the effect of sex on acute stress-induced HPA axis hormone activity is highly dependent on the type of stressor.

Variable effects of dexamethasone on protein synthesis in clonal rat osteosarcoma cells

International Nuclear Information System (INIS)

Hodge, B.O.; Kream, B.E.

1988-01-01

We examined the effects of dexamethasone on protein synthesis in clonal rat osteoblastic osteosarcoma (ROS) cell lines by measuring the incorporation of [ 3 H]proline into collagenase-digestible and noncollagen protein in the cell layer and medium of the cultures. In ROS 17/2 and subclone C12 of ROS 17/2.8, dexamethasone decreased collagen synthesis with no change in DNA content of the cultures. In ROS 17/2.8 and its subclone G2, dexamethasone stimulated collagen and noncollagen protein synthesis, with a concomitant decrease in the DNA content of the cells. These data indicate that ROS cell lines are phenotypically heterogeneous and suggest that in normal bone there may be distinct subpopulations of osteoblasts with varying phenotypic traits with respect to the regulation of protein synthesis

Effects of dexamethasone coadministered with oseltamivir on the pharmacokinetics of oseltamivir in healthy volunteers

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Jang K

2017-03-01

Full Text Available Kyungho Jang,1,2,* Min-Kyoung Kim,3,4,* Jaeseong Oh,1 SeungHwan Lee,1 Joo-Youn Cho,1 Kyung-Sang Yu,1 Tai Kiu Choi,3 Sang-Hyuk Lee,3,4 Kyoung Soo Lim4 1Department of Clinical Pharmacology and Therapeutics, Seoul National University College of Medicine and Hospital, Seoul, 2Center for Clinical Pharmacology and Biomedical Research Institute, Chonbuk National University Medical School, Jeonju, 3Department of Psychiatry, 4Department of Clinical Pharmacology and Therapeutics, CHA University School of Medicine and CHA Bundang Medical Center, Seongnam, Republic of Korea *These authors contributed equally to this work Purpose: Oseltamivir is widely used in the treatment and prophylaxis of influenza A and B viral infections. It is ingested as an oral prodrug that is rapidly metabolized by carboxylesterase 1 (CES1 to its active form, oseltamivir carboxylate. Dexamethasone is also used in the treatment of acute respiratory distress syndrome, a severe complication of influenza; however, its influence on the pharmacokinetics (PK of oseltamivir is controversial. The aim of this study was to investigate the effects of coadministering oseltamivir and dexamethasone on the PK of oseltamivir in healthy volunteers. Methods: An open-label, two-period, one-sequence, multiple-dose study was conducted in 19 healthy male volunteers. Oseltamivir (75 mg was orally administered on Day 1 and Day 8, and dexamethasone (1.5 mg was administered once daily from Day 3 to Day 8. Serial blood and urine samples were collected for PK analysis of oseltamivir and oseltamivir carboxylate on Day 1 and Day 8. Oseltamivir and oseltamivir carboxylate concentrations in plasma and urine were determined using liquid chromatography–tandem mass spectrometry. Results: Area under the plasma concentration–time curve (AUC of oseltamivir and oseltamivir carboxylate decreased after dexamethasone treatment for 6 days. The geometric mean ratio (90% confidence interval of the metabolic ratio

[Anthology of the first clinical studies with hypothalamic hormones: a story of successful international cooperation].

Science.gov (United States)

Schally, Andrew V; Gual, Carlos

2002-01-01

Our early pioneering clinical trials in Mexico with natural and synthetic thyrotropin-releasing hormone (TRH) and luteinizing hormone releasing hormone (LH-RH) also known as gonadotropin releasing hormone (Gn-RH), were reviewed. Highly purified TRH of porcine origin was shown to stimulate Thyrotropin (TSH) release in hypothyroid cretins. Subsequent tests with synthetic TRH also demonstrated significant increases in plasma TSH in normal men and women as well as in patients with primary hypothyroidism and other endocrine disorders. Even more extensive clinical studies were carried out with highly purified natural porcine LH-RH. Subjects with normal basal serum levels of gonadotropins, low levels (men and women pretreated with steroids) and high levels (e.g. post menopausal women) all responded to LH-RH with a release of LH and FSH. The results of these early studies with the natural LH-RH were confirmed by the use of synthetic LH-RH. These investigations made in Mexico with TRH and LH-RH preceded all other clinical studies by a wide margin. Subsequently various clinical investigations with LH-RH agonists and antagonists were also carried out. All these studies played a major role in introducing hypothalamic-releasing hormones into clinical medicine.

Effect of stage of development and sex on gonadotropin-releasing hormone secretion in in vitro hypothalamic perifusion.

Science.gov (United States)

Lacau-Mengido, I M; González Iglesias, A; Díaz-Torga, G; Thyssen-Cano, S; Libertun, C; Becú-Villalobos, D

1998-04-01

Marked sexual and ontogenic differences have been described in gonadotropin regulation in the rat. These could arise from events occurring both at the hypothalamic or hypophyseal levels. The present experiments were designed to evaluate the capacity of the hypothalamus in releasing GnRH in vitro, basally and in response to depolarization with KCl, during ontogeny in the rat. To that end we chose two well-defined developmental ages that differ markedly in sexual and ontogenic characteristics of gonadotropin regulation, 15 and 30 days. We compared GnRH release from hypothalami of females, neonatal androgenized females and males. Mediobasal hypothalami were perifused in vitro, and GnRH measured in the effluent. Basal secretion of the decapeptide increased with age in the three groups with no sexual differences encountered. When studying GnRH release induced by membrane depolarization, no differences within sex or age were encountered. On the other hand FSH serum levels decreased with age in females and increased in males, and in neonatal androgenized females followed a similar pattern to that of females. LH levels were higher in infantile females than in age-matched males or androgenized females. Such patterns of gonadotropin release were therefore not correlated to either basal or K+-induced GnRH release from the hypothalamus. We conclude that sexual and ontogenic differences in gonadotropin secretion in the developing rat are not dependent on the intrinsic capability of the hypothalamus to release GnRH in response to membrane depolarization. The hormonal differences observed during development and between sexes are probably related to differences in the sensitivity of the GnRH neuron to specific secretagogue and neurotransmitter regulation, and/or to differences in hypophyseal GnRH receptors and gonadotrope sensitivity.

Protein alterations induced by long-term agonist treatment of HEK293 cells expressing thyrotropin-releasing hormone receptor and G11alpha protein

Czech Academy of Sciences Publication Activity Database

Drastichová, Z.; Bouřová, Lenka; Hejnová, L.; Jedelský, P.; Svoboda, Petr; Novotný, J.

2010-01-01

Roč. 109, č. 1 (2010), s. 255-264 ISSN 0730-2312 R&D Projects: GA MŠk(CZ) LC554; GA ČR(CZ) GA309/06/0121; GA ČR(CZ) GD305/08/H037 Institutional research plan: CEZ:AV0Z50110509 Keywords : Thyrotropin-releasing hormone * Gq/11 protein * proteomics Subject RIV: ED - Physiology Impact factor: 3.122, year: 2010

A multicenter, randomized, controlled trial of dexamethasone for bronchiolitis.

Science.gov (United States)

Corneli, Howard M; Zorc, Joseph J; Mahajan, Prashant; Majahan, Prashant; Shaw, Kathy N; Holubkov, Richard; Reeves, Scott D; Ruddy, Richard M; Malik, Baqir; Nelson, Kyle A; Bregstein, Joan S; Brown, Kathleen M; Denenberg, Matthew N; Lillis, Kathleen A; Cimpello, Lynn Babcock; Tsung, James W; Borgialli, Dominic A; Baskin, Marc N; Teshome, Getachew; Goldstein, Mitchell A; Monroe, David; Dean, J Michael; Kuppermann, Nathan

2007-07-26

Bronchiolitis, the most common infection of the lower respiratory tract in infants, is a leading cause of hospitalization in childhood. Corticosteroids are commonly used to treat bronchiolitis, but evidence of their effectiveness is limited. We conducted a double-blind, randomized trial comparing a single dose of oral dexamethasone (1 mg per kilogram of body weight) with placebo in 600 children (age range, 2 to 12 months) with a first episode of wheezing diagnosed in the emergency department as moderate-to-severe bronchiolitis (defined by a Respiratory Distress Assessment Instrument score > or =6). We enrolled patients at 20 emergency departments during the months of November through April over a 3-year period. The primary outcome was hospital admission after 4 hours of emergency department observation. The secondary outcome was the Respiratory Assessment Change Score (RACS). We also evaluated later outcomes: length of hospital stay, later medical visits or admissions, and adverse events. Baseline characteristics were similar in the two groups. The admission rate was 39.7% for children assigned to dexamethasone, as compared with 41.0% for those assigned to placebo (absolute difference, -1.3%; 95% confidence interval [CI], -9.2 to 6.5). Both groups had respiratory improvement during observation; the mean 4-hour RACS was -5.3 for dexamethasone, as compared with -4.8 for placebo (absolute difference, -0.5; 95% CI, -1.3 to 0.3). Multivariate adjustment did not significantly alter the results, nor were differences detected in later outcomes. In infants with acute moderate-to-severe bronchiolitis who were treated in the emergency department, a single dose of 1 mg of oral dexamethasone per kilogram did not significantly alter the rate of hospital admission, the respiratory status after 4 hours of observation, or later outcomes. (ClinicalTrials.gov number, NCT00119002 [ClinicalTrials.gov].). Copyright 2007 Massachusetts Medical Society.

Enhancement of a robust arcuate GABAergic input to gonadotropin-releasing hormone neurons in a model of polycystic ovarian syndrome.

Science.gov (United States)

Moore, Aleisha M; Prescott, Mel; Marshall, Christopher J; Yip, Siew Hoong; Campbell, Rebecca E

2015-01-13

Polycystic ovarian syndrome (PCOS), the leading cause of female infertility, is associated with an increase in luteinizing hormone (LH) pulse frequency, implicating abnormal steroid hormone feedback to gonadotropin-releasing hormone (GnRH) neurons. This study investigated whether modifications in the synaptically connected neuronal network of GnRH neurons could account for this pathology. The PCOS phenotype was induced in mice following prenatal androgen (PNA) exposure. Serial blood sampling confirmed that PNA elicits increased LH pulse frequency and impaired progesterone negative feedback in adult females, mimicking the neuroendocrine abnormalities of the clinical syndrome. Imaging of GnRH neurons revealed greater dendritic spine density that correlated with increased putative GABAergic but not glutamatergic inputs in PNA mice. Mapping of steroid hormone receptor expression revealed that PNA mice had 59% fewer progesterone receptor-expressing cells in the arcuate nucleus of the hypothalamus (ARN). To address whether increased GABA innervation to GnRH neurons originates in the ARN, a viral-mediated Cre-lox approach was taken to trace the projections of ARN GABA neurons in vivo. Remarkably, projections from ARN GABAergic neurons heavily contacted and even bundled with GnRH neuron dendrites, and the density of fibers apposing GnRH neurons was even greater in PNA mice (56%). Additionally, this ARN GABA population showed significantly less colocalization with progesterone receptor in PNA animals compared with controls. Together, these data describe a robust GABAergic circuit originating in the ARN that is enhanced in a model of PCOS and may underpin the neuroendocrine pathophysiology of the syndrome.

Silibinin, dexamethasone, and doxycycline as potential therapeutic agents for treating vesicant-inflicted ocular injuries

International Nuclear Information System (INIS)

Tewari-Singh, Neera; Jain, Anil K.; Inturi, Swetha; Ammar, David A.; Agarwal, Chapla; Tyagi, Puneet; Kompella, Uday B.; Enzenauer, Robert W.; Petrash, J. Mark; Agarwal, Rajesh

2012-01-01

There are no effective and approved therapies against devastating ocular injuries caused by vesicating chemical agents sulfur mustard (SM) and nitrogen mustard (NM). Herein, studies were carried out in rabbit corneal cultures to establish relevant ocular injury biomarkers with NM for screening potential efficacious agents in laboratory settings. NM (100 nmol) exposure of the corneas for 2 h (cultured for 24 h), showed increases in epithelial thickness, ulceration, apoptotic cell death, epithelial detachment microbullae formation, and the levels of VEGF, cyclooxygenase-2 (COX-2) and matrix metalloproteinase-9 (MMP-9). Employing these biomarkers, efficacy studies were performed with agent treatments 2 h and every 4 h thereafter, for 24 h following NM exposure. Three agents were evaluated, including prescription drugs dexamethasone (0.1%; anti-inflammatory steroid) and doxycycline (100 nmol; antibiotic and MMP inhibitor) that have been studied earlier for treating vesicant-induced eye injuries. We also examined silibinin (100 μg), a non-toxic natural flavanone found to be effective in treating SM analog-induced skin injuries in our earlier studies. Treatments of doxycycline + dexamethasone, and silibinin were more effective than doxycycline or dexamethasone alone in reversing NM-induced epithelial thickening, microbullae formation, apoptotic cell death, and MMP-9 elevation. However, dexamethasone and silibinin alone were more effective in reversing NM-induced VEGF levels. Doxycycline, dexamethasone and silibinin were all effective in reversing NM-induced COX-2 levels. Apart from therapeutic efficacy of doxycycline and dexamethasone, these results show strong multifunctional efficacy of silibinin in reversing NM-induced ocular injuries, which could help develop effective and safe therapeutics against ocular injuries by vesicants. -- Highlights: ► Established injury biomarkers in rabbit corneal culture with nitrogen mustard (NM) ► This NM model is a cost effective

Silibinin, dexamethasone, and doxycycline as potential therapeutic agents for treating vesicant-inflicted ocular injuries

Energy Technology Data Exchange (ETDEWEB)

Tewari-Singh, Neera, E-mail: Neera.Tewari-Singh@ucdenver.edu [Department of Pharmaceutical Sciences, University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences, Aurora, CO 80045 (United States); Jain, Anil K., E-mail: Anil.Jain@ucdenver.edu [Department of Pharmaceutical Sciences, University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences, Aurora, CO 80045 (United States); Inturi, Swetha, E-mail: Swetha.Inturi@ucdenver.edu [Department of Pharmaceutical Sciences, University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences, Aurora, CO 80045 (United States); Ammar, David A., E-mail: David.Ammar@ucdenver.edu [Department of Ophthalmology, University of Colorado School of Medicine, Aurora, CO 80045 (United States); Agarwal, Chapla, E-mail: Chapla.Agarwal@ucdenver.edu [Department of Pharmaceutical Sciences, University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences, Aurora, CO 80045 (United States); Tyagi, Puneet, E-mail: Puneet.Tyagi@ucdenver.edu [Department of Pharmaceutical Sciences, University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences, Aurora, CO 80045 (United States); Kompella, Uday B., E-mail: Uday.Kompella@ucdenver.edu [Department of Pharmaceutical Sciences, University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences, Aurora, CO 80045 (United States); Enzenauer, Robert W., E-mail: Robert.Enzenauer@ucdenver.edu [Department of Ophthalmology, University of Colorado School of Medicine, Aurora, CO 80045 (United States); Petrash, J. Mark, E-mail: Mark.Petrash@ucdenver.edu [Department of Ophthalmology, University of Colorado School of Medicine, Aurora, CO 80045 (United States); Agarwal, Rajesh, E-mail: Rajesh.Agarwal@ucdenver.edu [Department of Pharmaceutical Sciences, University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences, Aurora, CO 80045 (United States)

2012-10-01

There are no effective and approved therapies against devastating ocular injuries caused by vesicating chemical agents sulfur mustard (SM) and nitrogen mustard (NM). Herein, studies were carried out in rabbit corneal cultures to establish relevant ocular injury biomarkers with NM for screening potential efficacious agents in laboratory settings. NM (100 nmol) exposure of the corneas for 2 h (cultured for 24 h), showed increases in epithelial thickness, ulceration, apoptotic cell death, epithelial detachment microbullae formation, and the levels of VEGF, cyclooxygenase-2 (COX-2) and matrix metalloproteinase-9 (MMP-9). Employing these biomarkers, efficacy studies were performed with agent treatments 2 h and every 4 h thereafter, for 24 h following NM exposure. Three agents were evaluated, including prescription drugs dexamethasone (0.1%; anti-inflammatory steroid) and doxycycline (100 nmol; antibiotic and MMP inhibitor) that have been studied earlier for treating vesicant-induced eye injuries. We also examined silibinin (100 μg), a non-toxic natural flavanone found to be effective in treating SM analog-induced skin injuries in our earlier studies. Treatments of doxycycline + dexamethasone, and silibinin were more effective than doxycycline or dexamethasone alone in reversing NM-induced epithelial thickening, microbullae formation, apoptotic cell death, and MMP-9 elevation. However, dexamethasone and silibinin alone were more effective in reversing NM-induced VEGF levels. Doxycycline, dexamethasone and silibinin were all effective in reversing NM-induced COX-2 levels. Apart from therapeutic efficacy of doxycycline and dexamethasone, these results show strong multifunctional efficacy of silibinin in reversing NM-induced ocular injuries, which could help develop effective and safe therapeutics against ocular injuries by vesicants. -- Highlights: ► Established injury biomarkers in rabbit corneal culture with nitrogen mustard (NM) ► This NM model is a cost effective

Inhibition of growth hormone and prolactin secretion by a serine proteinase inhibitor

International Nuclear Information System (INIS)

Rappay, G.; Nagy, I.; Makara, G.B.; Horvath, G.; Karteszi, M.; Bacsy, E.; Stark, E.

1984-01-01

The action of the tripeptide aldehyde t-butyloxycarbonyl-DPhe-Pro-Arg-H (boc-fPR-H), belonging to a family of serine proteinase inhibitors, on the release of immunoreactive prolactin (iPRL) and growth hormone (iGH) has been studied. In rat anterior pituitary cell cultures and pituitary quarters 1 mM boc-fPR-H inhibited basal iPRL and iGH release. Thyroliberin-induced iPRL release by cultured cells was also markedly inhibited with a concomitant accumulation of intracellular iPRL. During the short- and long-term exposure of cells to boc-fPR-H there were no changes in total cell protein contents and in activities of some lysosomal marker enzymes. The marked inhibition of basal as well as stimulated hormone release in the presence of the enzyme inhibitor might suggest that at least a portion of the hormones is released via a proteolytic enzyme-dependent process

Prophylactic antiemetic effects of midazolam, dexamethasone, and its combination after middle ear surgery

International Nuclear Information System (INIS)

Makhdoom, Naeem K; Farid, Magdy F

2009-01-01

To evaluate and compare the efficacy of the combination of midazolam and dexamethasone, with midazolam and dexamethasone alone, for the prevention of postoperative nausea and vomiting (PONV) in female patients undergoing middle ear surgery. A prospective, randomized, double-blind, placebo-controlled study in 80 female patients (mean age 32.6 years), undergoing middle ear surgery with general anesthesia at Ohud Hospital, Madina, Kingdom of Saudi Arabia from May 2007 to May 2008. Patients were classified into 4 groups. They received intravenous normal saline (S group), midazolam 0.075 mg/kg (M group), or dexamethasone 10 mg (D group), or a combination of midazolam and dexamethasone (MD group), before the induction of anesthesia. Postoperatively for 24 hours observation and assessment of nausea, vomiting, rescue anti-emetics, and side effects of the study drugs such as headache and drowsiness were carried out. There was a significant difference between the 4 groups. The MD group was the least to develop PONV compared to other groups (p<0.01). Regarding nausea, there was a non-significant difference between the 4 groups, although the MD group developed the least symptoms among the 4 groups, there were no significant differences in pain intensity and side effects such as, headache, dizziness, and drowsiness between the 4 groups. The combination of midazolam 0.075 mg/kg and dexamethasone 10 mg intravenously is better than either drug alone in reducing the incidence of PONV in female patients after middle ear surgery. (author)

Developments in human growth hormone preparations: sustained-release, prolonged half-life, novel injection devices, and alternative delivery routes

Directory of Open Access Journals (Sweden)

Cai Y

2014-07-01

Full Text Available Yunpeng Cai,1,2 Mingxin Xu,2 Minglu Yuan,2 Zhenguo Liu,1 Weien Yuan2 1Department of Neurology, Xinhua Hospital, School of Medicine, 2School of Pharmacy, Shanghai Jiao Tong University, Shanghai, People’s Republic of China Abstract: Since the availability of recombinant human growth hormone (rhGH enabled the application of human growth hormone both in clinical and research use in the 1980s, millions of patients were prescribed a daily injection of rhGH, but noncompliance rates were high. To address the problem of noncompliance, numerous studies have been carried out, involving: sustained-release preparations, prolonged half-life derivatives, new injectors that cause less pain, and other noninvasive delivery methods such as intranasal, pulmonary and transdermal deliveries. Some accomplishments have been made and launched already, such as the Nutropin Depot® microsphere and injectors (Zomajet®, Serojet®, and NordiFlex®. Here, we provide a review of the different technologies and illustrate the key points of these studies to achieve an improved rhGH product. Keywords: intranasal, pulmonary, transdermal, microsphere, microneedle, hydrogel

Simultaneous RP-HPLC determination of sparfloxacin and dexamethasone in pharmaceutical formulations

Directory of Open Access Journals (Sweden)

Syed Naeem Razzaq

2013-06-01

Full Text Available The present study describes the development and subsequent validation of simple and accurate stability indicating RP-HPLC method for the determination of sparfloxacin and dexamethasone in pharmaceutical formulations in the presence of their stress-induced degradation products. Both the drugs and their stress-induced degradation products were separated within 10 minutes using C8 column and mixture of methanol and 0.02 M phosphate buffer pH 3.0 (60:40 v/v, respectively as mobile phase at 270 nm using diode array detector. Regression analysis showed linearity in the range of 15-105 µg/mL for sparfloxacin and 5-35 µg/mL for dexamethasone. All the analytes were adequately resolved with acceptable tailing. Peak purity of the two drugs was also greater than 0.9999, showing no co-elution peaks. The developed method was applied for simultaneous determination of sparfloxacin and dexamethasone in pharmaceutical formulations for stability studies.