Pituitary-hormone secretion by thyrotropinomas

OpenAIRE

Roelfsema, Ferdinand; Kok, Simon; Kok, Petra; Pereira, Alberto M.; Biermasz, Nienke R.; Smit, Jan W.; Frolich, Marijke; Keenan, Daniel M.; Veldhuis, Johannes D.; Romijn, Johannes A.

2008-01-01

Hormone secretion by somatotropinomas, corticotropinomas and prolactinomas exhibits increased pulse frequency, basal and pulsatile secretion, accompanied by greater disorderliness. Increased concentrations of growth hormone (GH) or prolactin (PRL) are observed in about 30% of thyrotropinomas leading to acromegaly or disturbed sexual functions beyond thyrotropin (TSH)-induced hyperthyroidism. Regulation of non-TSH pituitary hormones in this context is not well understood. We there therefore ev...

Pituitary-hormone secretion by thyrotropinomas.

Science.gov (United States)

Roelfsema, Ferdinand; Kok, Simon; Kok, Petra; Pereira, Alberto M; Biermasz, Nienke R; Smit, Jan W; Frolich, Marijke; Keenan, Daniel M; Veldhuis, Johannes D; Romijn, Johannes A

2009-01-01

Hormone secretion by somatotropinomas, corticotropinomas and prolactinomas exhibits increased pulse frequency, basal and pulsatile secretion, accompanied by greater disorderliness. Increased concentrations of growth hormone (GH) or prolactin (PRL) are observed in about 30% of thyrotropinomas leading to acromegaly or disturbed sexual functions beyond thyrotropin (TSH)-induced hyperthyroidism. Regulation of non-TSH pituitary hormones in this context is not well understood. We there therefore evaluated TSH, GH and PRL secretion in 6 patients with up-to-date analytical and mathematical tools by 24-h blood sampling at 10-min intervals in a clinical research laboratory. The profiles were analyzed with a new deconvolution method, approximate entropy, cross-approximate entropy, cross-correlation and cosinor regression. TSH burst frequency and basal and pulsatile secretion were increased in patients compared with controls. TSH secretion patterns in patients were more irregular, but the diurnal rhythm was preserved at a higher mean with a 2.5 h phase delay. Although only one patient had clinical acromegaly, GH secretion and IGF-I levels were increased in two other patients and all three had a significant cross-correlation between the GH and TSH. PRL secretion was increased in one patient, but all patients had a significant cross-correlation with TSH and showed decreased PRL regularity. Cross-ApEn synchrony between TSH and GH did not differ between patients and controls, but TSH and PRL synchrony was reduced in patients. We conclude that TSH secretion by thyrotropinomas shares many characteristics of other pituitary hormone-secreting adenomas. In addition, abnormalities in GH and PRL secretion exist ranging from decreased (joint) regularity to overt hypersecretion, although not always clinically obvious, suggesting tumoral transformation of thyrotrope lineage cells.

Nanoscaffold matrices for size-controlled, pulsatile transdermal testosterone delivery: nanosize effects on the time dimension

International Nuclear Information System (INIS)

Malik, Ritu; Misra, Amit; Tondwal, Shailesh; Venkatesh, K S

2008-01-01

Pulsatile transdermal testosterone (T) has applications in hormone supplementation and male contraception. Pulsatile T delivery was achieved by assembling crystalline and nanoparticulate T in nucleation-inhibiting polymer matrices of controlled porosity. Different interference patterns observed from various polymeric films containing T were due to the various particle sizes of T present in the polymer matrices. Scanning electron microscopy was used to determine the size and shape of T crystals. Skin-adherent films containing T nanoparticles of any size between 10-500 nm could be prepared using pharmaceutically acceptable vinylic polymers. Drug release and skin permeation profiles were studied. The dissolution-diffusion behavior of nanoparticles differed from crystalline and molecular states. Nanosize may thus be used to engineer chronopharmacologically relevant drug delivery.

Nanoscaffold matrices for size-controlled, pulsatile transdermal testosterone delivery: nanosize effects on the time dimension

Science.gov (United States)

Malik, Ritu; Tondwal, Shailesh; Venkatesh, K. S.; Misra, Amit

2008-10-01

Pulsatile transdermal testosterone (T) has applications in hormone supplementation and male contraception. Pulsatile T delivery was achieved by assembling crystalline and nanoparticulate T in nucleation-inhibiting polymer matrices of controlled porosity. Different interference patterns observed from various polymeric films containing T were due to the various particle sizes of T present in the polymer matrices. Scanning electron microscopy was used to determine the size and shape of T crystals. Skin-adherent films containing T nanoparticles of any size between 10-500 nm could be prepared using pharmaceutically acceptable vinylic polymers. Drug release and skin permeation profiles were studied. The dissolution-diffusion behavior of nanoparticles differed from crystalline and molecular states. Nanosize may thus be used to engineer chronopharmacologically relevant drug delivery.

Surface obstacles in pulsatile flow

Science.gov (United States)

Carr, Ian A.; Plesniak, Michael W.

2017-11-01

Flows past obstacles mounted on flat surfaces have been widely studied due to their ubiquity in nature and engineering. For nearly all of these studies, the freestream flow over the obstacle was steady, i.e., constant velocity, unidirectional flow. Unsteady, pulsatile flows occur frequently in biology, geophysics, biomedical engineering, etc. Our study is aimed at extending the comprehensive knowledge base that exists for steady flows to considerably more complex pulsatile flows. Characterizing the vortex and wake dynamics of flows around surface obstacles embedded in pulsatile flows can provide insights into the underlying physics in all wake and junction flows. In this study, we experimentally investigate the wake of two canonical obstacles: a cube and a circular cylinder with an aspect ratio of unity. Our previous studies of a surface-mounted hemisphere in pulsatile flow are used as a baseline for these two new, more complex geometries. Phase-averaged PIV and hot-wire anemometry are used to characterize the dynamics of coherent structures in the wake and at the windward junction of the obstacles. Complex physics occur during the deceleration phase of the pulsatile inflow. We propose a framework for understanding these physics based on self-induced vortex propagation, similar to the phenomena exhibited by vortex rings.

21 CFR 870.4320 - Cardiopulmonary bypass pulsatile flow generator.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiopulmonary bypass pulsatile flow generator... Cardiopulmonary bypass pulsatile flow generator. (a) Identification. A cardiopulmonary bypass pulsatile flow generator is an electrically and pneumatically operated device used to create pulsatile blood flow. The...

Pulmonary O2 transfer during pulsatile and non-pulsatile perfusion.

Science.gov (United States)

Hauge, A; Nicolaysen, G

1980-07-01

The importance of the perfusion pattern for the oxygen transfer has been examined in isolated rabbit lungs perfused with plasma at constant volume inflow. The lungs were ventilated with constant tidal volume and constant end-expiratory pressure. Following a standardized rise in FIO2 the rate of rise in pulmonary venous PO2 (delta PO2/delta t) was measured during alternately pulsatile and non-pulsatile perfusion in normal lungs and in lungs made edematous by elevation of left atrial pressure. In normal lungs there was no difference in delta PO2/delta t when the two modes of perfusion were compared. In edematous lungs delta PO/delta t was statistically higher during pulsatile perfusion, indicating a beneficial effect of flow- and pressure pulsations, e.g. a better distribution of V/Q ratios throughout the lungs. In a separate series of expts. the advancement of a high O2 front through the airways was measured, and the two perfusion patterns compared. Since no difference was found, we suggest that the phenomenon of "cardiogenic gas mixing" in the airways in vivo is a result of a direct action of the heart on the lungs rather than arterial pulsations.

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.

Imaging in pulsatile tinnitus

International Nuclear Information System (INIS)

Madani, G.; Connor, S.E.J.

2009-01-01

Tinnitus may be continuous or pulsatile. Vascular lesions are the most frequent radiologically demonstrable cause of pulsatile tinnitus. These include congenital vascular anomalies (which may be arterial or venous), vascular tumours, and a variety of acquired vasculopathies. The choice of imaging depends on the clinical findings. If a mass is present at otoscopy, thin-section computed tomography (CT) is indicated. In the otoscopically normal patient, there is a range of possible imaging approaches. However, combined CT angiography and venography is particularly useful

Imaging in pulsatile tinnitus

Energy Technology Data Exchange (ETDEWEB)

Madani, G. [Radiology Department, St Mary' s Hospital, London (United Kingdom)], E-mail: gittamadani@yahoo.com; Connor, S E.J. [Neuroradiology Department, King' s College Hospital, London (United Kingdom)

2009-03-15

Tinnitus may be continuous or pulsatile. Vascular lesions are the most frequent radiologically demonstrable cause of pulsatile tinnitus. These include congenital vascular anomalies (which may be arterial or venous), vascular tumours, and a variety of acquired vasculopathies. The choice of imaging depends on the clinical findings. If a mass is present at otoscopy, thin-section computed tomography (CT) is indicated. In the otoscopically normal patient, there is a range of possible imaging approaches. However, combined CT angiography and venography is particularly useful.

Pulsatile luteinizing hormone secretion in patients with Addison's disease. Impact of glucocorticoid substitution

DEFF Research Database (Denmark)

Hangaard, J; Andersen, M; Grodum, E

1998-01-01

The physiological and pathophysiological role of cortisol in pulsatile LH release was investigated in 14 patients (5 men, 6 premenopausal women, and 3 postmenopausal women) with Addison's disease. The explicit effect of cortisol in relation to the effect of corticotropin-releasing factor (CRF......), ACTH, and opioids was ensured by hypo-, normo-, and hypercortisolism. Hypocortisolism was obtained by 24-h discontinuation of hydrocortisone (HC) followed by 23-h saline infusion. Eucortisolism was secured by infusion of HC (0.5 mg/kg) over 23 h. Stress-appropriate hypercortisolism was obtained...

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.

Does polycystic ovarian morphology influence the response to treatment with pulsatile GnRH in functional hypothalamic amenorrhea?

Science.gov (United States)

Dumont, Agathe; Dewailly, Didier; Plouvier, Pauline; Catteau-Jonard, Sophie; Robin, Geoffroy

2016-04-29

Pulsatile GnRH therapy is the gold standard treatment for ovulation induction in women having functional hypothalamic amenorrhea (FHA). The use of pulsatile GnRH therapy in FHA patients with polycystic ovarian morphology (PCOM), called "FHA-PCOM", has been little studied in the literature and results remain contradictory. The aim of this study was to compare the outcomes of pulsatile GnRH therapy for ovulation induction between FHA and "FHA-PCOM" patients in order to search for an eventual impact of PCOM. Retrospective study from August 2002 to June 2015, including 27 patients with FHA and 40 "FHA-PCOM" patients (85 and 104 initiated cycles, respectively) treated by pulsatile GnRH therapy for induction ovulation. The two groups were similar except for markers of PCOM (follicle number per ovary, serum Anti-Müllerian Hormone level and ovarian area), which were significantly higher in patients with "FHA-PCOM". There was no significant difference between the groups concerning the ovarian response: with equivalent doses of GnRH, both groups had similar ovulation (80.8 vs 77.7 %, NS) and excessive response rates (12.5 vs 10.6 %, NS). There was no significant difference in on-going pregnancy rates (26.9 vs 20 % per initiated cycle, NS), as well as in miscarriage, multiple pregnancy or biochemical pregnancy rates. Pulsatile GnRH seems to be a successful and safe method for ovulation induction in "FHA-PCOM" patients. If results were confirmed by prospective studies, GnRH therapy could therefore become a first-line treatment for this specific population, just as it is for women with FHA without PCOM.

Does the location of a vascular loop in the cerebellopontine angle explain pulsatile and non-pulsatile tinnitus?

International Nuclear Information System (INIS)

Nowe, V.; Wang, X.L.; Gielen, J.; Goethem, J.Van; Oezsarlak, Oe.; De Schepper, A.M.; Parizel, P.M.; Ridder, D. De; Heyning, P.H.Van de

2004-01-01

The purpose was to investigate patients with unexplained pulsatile and non-pulsatile tinnitus by means of MR imaging of the cerebellopontine angle (CPA) and to correlate the clinical subtype of tinnitus with the location of a blood vessel (in the internal auditory canal or at the cisternal part of the VIIIth cranial nerve). Clinical presentation of tinnitus and perceptive hearing loss were correlated. In 47 patients with unexplained tinnitus, an MR examination of the CPA was performed. Virtual endoscopy reconstructions were obtained using a 3D axial thin-section high-resolution heavily T2-weighted gradient echo constructive interference in steady state (CISS) data-set. High-resolution T2-weighted CISS images showed a significantly higher number of vascular loops in the internal auditory canal in patients with arterial pulsatile tinnitus compared to patients with non-pulsatile tinnitus (P<0.00001). Virtual endoscopy images were used to investigate vascular contacts at the cisternal part of the VIIIth cranial nerve in patients with low pitch and high pitch non-pulsatile tinnitus. A significantly different distribution of the vascular contacts (P=0.0320) was found. Furthermore, a correlation between the clinical presentation of non-pulsatile tinnitus (high pitch and low pitch) and the perceptive hearing loss was found (P=0.0235). High-resolution heavily T2-weighted CISS images and virtual endoscopy of the CPA can be used to evaluate whether a vascular contact is present in the internal auditory canal or at the cisternal part of the VIIIth cranial nerve and whether the location of the vascular contact correlates with the clinical subtype of tinnitus. Our findings suggest that there is a tonotopical structure of the cisternal part of the VIIIth cranial nerve. A correlation between the clinical presentation of tinnitus and hearing loss was found. (orig.)

Does the location of a vascular loop in the cerebellopontine angle explain pulsatile and non-pulsatile tinnitus?

Energy Technology Data Exchange (ETDEWEB)

Nowe, V; Wang, X L; Gielen, J; Goethem, J Van; Oezsarlak, Oe; De Schepper, A M; Parizel, P M [University of Antwerp, Department of Radiology, Edegem (Belgium); Ridder, D De [University of Antwerp, Department of Neurosurgery, Edegem (Belgium); Heyning, P.H.Van de [University of Antwerp, Department of Otorhinolaryngology, Edegem (Belgium)

2004-12-01

The purpose was to investigate patients with unexplained pulsatile and non-pulsatile tinnitus by means of MR imaging of the cerebellopontine angle (CPA) and to correlate the clinical subtype of tinnitus with the location of a blood vessel (in the internal auditory canal or at the cisternal part of the VIIIth cranial nerve). Clinical presentation of tinnitus and perceptive hearing loss were correlated. In 47 patients with unexplained tinnitus, an MR examination of the CPA was performed. Virtual endoscopy reconstructions were obtained using a 3D axial thin-section high-resolution heavily T2-weighted gradient echo constructive interference in steady state (CISS) data-set. High-resolution T2-weighted CISS images showed a significantly higher number of vascular loops in the internal auditory canal in patients with arterial pulsatile tinnitus compared to patients with non-pulsatile tinnitus (P<0.00001). Virtual endoscopy images were used to investigate vascular contacts at the cisternal part of the VIIIth cranial nerve in patients with low pitch and high pitch non-pulsatile tinnitus. A significantly different distribution of the vascular contacts (P=0.0320) was found. Furthermore, a correlation between the clinical presentation of non-pulsatile tinnitus (high pitch and low pitch) and the perceptive hearing loss was found (P=0.0235). High-resolution heavily T2-weighted CISS images and virtual endoscopy of the CPA can be used to evaluate whether a vascular contact is present in the internal auditory canal or at the cisternal part of the VIIIth cranial nerve and whether the location of the vascular contact correlates with the clinical subtype of tinnitus. Our findings suggest that there is a tonotopical structure of the cisternal part of the VIIIth cranial nerve. A correlation between the clinical presentation of tinnitus and hearing loss was found. (orig.)

Efficacy and safety of pulsatile gonadotropin-releasing hormone therapy among patients with idiopathic and functional hypothalamic amenorrhea: a systematic review of the literature and a meta-analysis.

Science.gov (United States)

Tranoulis, Anastasios; Laios, Alexandros; Pampanos, Andreas; Yannoukakos, Drakoulis; Loutradis, Dimitrios; Michala, Lina

2018-04-01

To systematically review and appraise the existing evidence in relation to the efficacy and safety of pulsatile gonadotropin-releasing hormone (pGnRH) for the treatment of women with hypothalamic amenorrhea (HA). Systematic review and meta-analysis. Not applicable. A total of 35 studies (three randomized and 32 observational) encompassing 1,002 women with HA. None. Primary outcomes: ovulation rate (OvR), pregnancy per ovulatory cycle rate (POR), and live birth per ovulatory cycle rate (LBOR). multiple gestation (MG), ovarian hyperstimulation syndrome (OHSS), and superficial thrombophlebitis (ST) rates. The summary measures were expressed as proportions and 95% confidence intervals (CI). Pulsatile GnRH treatment appears to achieve high OvRs. A trend toward high PORs and LBORs among women with HA is demonstrated. SC pGnRH achieves comparable OvR compared with IV pGnRH. The incidence of OHSS is low and of mild severity. Treatment with pGnRH is associated with low but slightly higher MG rates compared with the general population. IV administered pGnRH is rarely associated with ST. The high OvRs leading to a high rate of singleton pregnancies and the low likelihood of OHSS render the pGnRH treatment modality both effective and safe for the treatment of women with HA of either primary or secondary origin. Copyright © 2017 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Jointly Amplified Basal and Pulsatile Growth Hormone (GH) Secretion and Increased Process Irregularity in Women with Anorexia Nervosa

DEFF Research Database (Denmark)

Støving, R K; Veldhuis, J D; Flyvbjerg, A

1999-01-01

Anorexia nervosa (AN) is associated with multiple endocrine alterations. In the majority of AN patients, basal and GHRH-stimulated serum GH levels are increased. The metabolic effects of GH are known to be related to its pulsatile secretory pattern. The present study was performed to examine GH...

Induction of spermatogenesis and fertility in hypogonadotropic azoospermic men by intravenous pulsatile gonadotropin-releasing hormone (GnRH).

Science.gov (United States)

Blumenfeld, Z; Makler, A; Frisch, L; Brandes, J M

1988-06-01

Gonadotropin-releasing hormone (GnRH) has only recently become a helpful tool in the medication of hypogonadotropic hypogonadism (HH). Two azoospermic patients with HH who had previously been treated with hCG/hMG because of delayed puberty and each of whom had fathered a child after previous gonadotropin therapy were referred due to secondary failure of hCG/hMG treatment to induce spermatogenesis and fertility. A pulse study where blood was drawn every 15 minutes for LH, FSH and PRL RIAs was performed in each patient, and afterwards a bolus of i.v. GnRH was injected to assess gonadotropin responsiveness. A portable GnRH pump was connected to each patient so that it administered 5-20 micrograms of GnRH i.v. every 89 minutes. Spermatogenesis was first detected after 42 and 78 days respectively in the 2 treated HH men and 4 1/2 months from the start of treatment their wives became pregnant. No thrombophlebitis or other complications of the i.v. therapy occurred. In the case of the first patient, the semen was washed and concentrated and intra-uterine inseminations were carried out in an attempt to shorten the time needed to achieve fertility. The first pregnancy was successfully terminated at 38 weeks with the delivery of 2 heterozygotic normal male babies. The second pregnancy ended in spontaneous delivery of a healthy female. We conclude that i.v. pulsatile, intermittent GnRH administration is a safe, efficient and highly successful means of treating azoospermic men with HH.

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.

AN OVERVIEW ON PULSATILE FLOW DYNAMICS

OpenAIRE

Çarpinlioğlu, Melda Özdinç

2015-01-01

Pulsatile flow dynamics in reference to the relevant experimental research on the manner between the time periods of 1997- 2015 is presented in this paper. The flow field under discussion is generated through a rigid circular cross-sectional pipe as an axial slightly- compressible and sinusoidal one in a controlled range of the oscillation parameters. Laminar and turbulent flow regimes are considered with a particular emphasis devoted to the transitional characteristics of laminar pulsatile f...

Fluid-structure interaction modeling of aneurysmal arteries under steady-state and pulsatile blood flow: a stability analysis.

Science.gov (United States)

Sharzehee, Mohammadali; Khalafvand, Seyed Saeid; Han, Hai-Chao

2018-02-01

Tortuous aneurysmal arteries are often associated with a higher risk of rupture but the mechanism remains unclear. The goal of this study was to analyze the buckling and post-buckling behaviors of aneurysmal arteries under pulsatile flow. To accomplish this goal, we analyzed the buckling behavior of model carotid and abdominal aorta with aneurysms by utilizing fluid-structure interaction (FSI) method with realistic waveforms boundary conditions. FSI simulations were done under steady-state and pulsatile flow for normal (1.5) and reduced (1.3) axial stretch ratios to investigate the influence of aneurysm, pulsatile lumen pressure and axial tension on stability. Our results indicated that aneurysmal artery buckled at the critical buckling pressure and its deflection nonlinearly increased with increasing lumen pressure. Buckling elevates the peak stress (up to 118%). The maximum aneurysm wall stress at pulsatile FSI flow was (29%) higher than under static pressure at the peak lumen pressure of 130 mmHg. Buckling results show an increase in lumen shear stress at the inner side of the maximum deflection. Vortex flow was dramatically enlarged with increasing lumen pressure and artery diameter. Aneurysmal arteries are more susceptible than normal arteries to mechanical instability which causes high stresses in the aneurysm wall that could lead to aneurysm rupture.

Demonstration of uneven distribution of intracranial pulsatility in hydrocephalus patients.

Science.gov (United States)

Eide, Per K

2008-11-01

Data from intracranial pressure (ICP) recordings in patients with hydrocephalus were reviewed to determine whether intracranial pulsatility within the cerebrospinal fluid (CSF) of cerebral ventricles (ICP(LV)) may differ from that within the brain parenchyma (ICP(PAR)), and whether pulsatility may differ between noncommunicating ventricles. The authors retrieved data from recordings previously obtained in 7 patients with hydrocephalus (noncommunicating in 4 and communicating in 3) and shunt failure who received both an external ventricular drainage (EVD) and an ICP sensor as part of surveillance during intensive care. Simultaneous ICP(LV) and ICP(PAR) signals were available in 6 cases, and simultaneous signals from the lateral and fourth ventricles (ICP(LV) and ICP4V, respectively) were recorded in 1 case. The recordings with both signals were parsed into 6-second time windows. Pulsatility was characterized by the wave amplitude and rise time coefficient, and differences in pulsatility between the ICP(LV) and ICP(PAR) signals (6 cases) or ICP(LV) and ICP4V signals (1 case) were determined. There was uneven distribution of intracranial pulsatility in all 7 patients, shown as significantly elevated pulsatility (that is, higher wave amplitudes and rise time coefficients) within the ventricles (ICP(LV)) than within brain parenchyma (ICP(PAR)) in 6 patients, and significantly higher pulsatility in the fourth (ICP4V) than in the lateral (ICP(LV)) ventricles in 1 patient. Differences > or = 1 mm Hg in ICP wave amplitude were found in 0.5-100% (median 9.4%) of observations in the 7 patients (total number of 6-second time windows, 68,242). The present observations demonstrate uneven distribution of intracranial pulsatility in patients with hydrocephalus, higher pulse pressure amplitudes within the ventricular CSF (ICP(LV)) than within the brain parenchyma (ICP(PAR)). This may be one mechanism behind ventricular enlargement in hydrocephalus.

Pulsatile blood flow, shear force, energy dissipation and Murray's Law

Directory of Open Access Journals (Sweden)

Bengtsson Hans-Uno

2006-08-01

Full Text Available Abstract Background Murray's Law states that, when a parent blood vessel branches into daughter vessels, the cube of the radius of the parent vessel is equal to the sum of the cubes of the radii of daughter blood vessels. Murray derived this law by defining a cost function that is the sum of the energy cost of the blood in a vessel and the energy cost of pumping blood through the vessel. The cost is minimized when vessel radii are consistent with Murray's Law. This law has also been derived from the hypothesis that the shear force of moving blood on the inner walls of vessels is constant throughout the vascular system. However, this derivation, like Murray's earlier derivation, is based on the assumption of constant blood flow. Methods To determine the implications of the constant shear force hypothesis and to extend Murray's energy cost minimization to the pulsatile arterial system, a model of pulsatile flow in an elastic tube is analyzed. A new and exact solution for flow velocity, blood flow rate and shear force is derived. Results For medium and small arteries with pulsatile flow, Murray's energy minimization leads to Murray's Law. Furthermore, the hypothesis that the maximum shear force during the cycle of pulsatile flow is constant throughout the arterial system implies that Murray's Law is approximately true. The approximation is good for all but the largest vessels (aorta and its major branches of the arterial system. Conclusion A cellular mechanism that senses shear force at the inner wall of a blood vessel and triggers remodeling that increases the circumference of the wall when a shear force threshold is exceeded would result in the observed scaling of vessel radii described by Murray's Law.

Imaging findings of pulsatile tinnitus caused by sigmoid sinus abnormalities

International Nuclear Information System (INIS)

Liang Xihong; Wang Zhenchang; Gong Shusheng; Xia Yin; Wang Zhengyu; Yang Bentao; Yan Fei; Li Jing; Xian Junfang; Chen Guangli

2010-01-01

Objective: To study a rare CT finding of pulsatile tinnitus (PT) caused by sigmoid sinus abnormalities. Methods: The imaging data of PT caused by sigmoid sinus abnormalities were analyzed retrospectively in 15 patients (15 female). The median age was 45 years (24 to 63 years). The duration of persistence pulsatile tinnitus was from 0.5 year to 36.0 years (median time, 2.0 years). The tinnitus was at left side in 5 patients and right side in 10 patients. Fifteen patients underwent HRCT of the temporal bone. Of them, 12 patients underwent cerebral CT angiography and CT venogram (CTA/CTV), and 9 patients underwent cerebral digital subtraction angiography (DSA). Nine patients underwent transmastoid reconstruction surgery of the sigmoid sinus. Of them, the tinnitus was at left side in 2 patients and right side in 7 patients. Paired rank sum test was used to compare the cross-sectional area of the sigmoid sinus of the tinnitus side and normal side.Results: On HRCT, foca bony coarse defect is shown in the anterior sigmoid wall in 11 patients and anterolateral sigmoid wall in 4 patients. On CTA/CTV, the sigmoid sinus focally protuded into the adjacent mastoid air cells and formed diverticulum in 10 patients. The pulsatile tinnitus disappeared immediately after transmastoid reconstruction surgery of the sigmoid sinus in all 9 patients. The cross-sectional area of the sigmoid sinus of the tinnitus side was 100.6 (41.5-96.2)mm 2 , it was 77.0 (92.1-122.4)mm 2 in the nonmal side (Z=2.158, P=0.031). Conclusion: Focal bony defect of the sigmoid wall with sigmoid sinus diverticula is one of the causes which lead to pulsatile tinnitus, which can be easily identified by imaging examination. (authors)

Imaging findings of pulsatile tinnitus caused by sigmoid sinus abnormalities

Energy Technology Data Exchange (ETDEWEB)

Xihong, Liang; Zhenchang, Wang; Shusheng, Gong; Yin, Xia; Zhengyu, Wang; Bentao, Yang; Fei, Yan; Jing, Li; Junfang, Xian; Guangli, Chen [Department of Radiology, Beijing Tongren Hospital, Capital University of Medical Science, Beijing (China)

2010-04-15

Objective: To study a rare CT finding of pulsatile tinnitus (PT) caused by sigmoid sinus abnormalities. Methods: The imaging data of PT caused by sigmoid sinus abnormalities were analyzed retrospectively in 15 patients (15 female). The median age was 45 years (24 to 63 years). The duration of persistence pulsatile tinnitus was from 0.5 year to 36.0 years (median time, 2.0 years). The tinnitus was at left side in 5 patients and right side in 10 patients. Fifteen patients underwent HRCT of the temporal bone. Of them, 12 patients underwent cerebral CT angiography and CT venogram (CTA/CTV), and 9 patients underwent cerebral digital subtraction angiography (DSA). Nine patients underwent transmastoid reconstruction surgery of the sigmoid sinus. Of them, the tinnitus was at left side in 2 patients and right side in 7 patients. Paired rank sum test was used to compare the cross-sectional area of the sigmoid sinus of the tinnitus side and normal side.Results: On HRCT, foca bony coarse defect is shown in the anterior sigmoid wall in 11 patients and anterolateral sigmoid wall in 4 patients. On CTA/CTV, the sigmoid sinus focally protuded into the adjacent mastoid air cells and formed diverticulum in 10 patients. The pulsatile tinnitus disappeared immediately after transmastoid reconstruction surgery of the sigmoid sinus in all 9 patients. The cross-sectional area of the sigmoid sinus of the tinnitus side was 100.6 (41.5-96.2)mm{sup 2}, it was 77.0 (92.1-122.4)mm{sup 2} in the nonmal side (Z=2.158, P=0.031). Conclusion: Focal bony defect of the sigmoid wall with sigmoid sinus diverticula is one of the causes which lead to pulsatile tinnitus, which can be easily identified by imaging examination. (authors)

Chrono pharmacotherapy: A pulsatile Drug Delivery

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Huma Hameed

2015-01-01

Full Text Available Chronopharmacotherapy refers to a treatment in which controlled drug delivery is achieved according to circadian rhythms of disease by enhancing therapeutic outcomes and minimizing side effects. Colon targeting has gained great importance not only for the treatment of local diseases such as Crohn’s disease, inflammatory bowel disease and ulcerative colitis but also very important in systemic delivery of proteins/peptides, antiasthmatic drugs, antidiabetic agents and antihypertensive drugs, which mostly show their efficacy based on circadian rhythms of the body.Colon drug delivery is one of the difficult approaches to achieve the targeted and desired outcomes through pulsatile drug delivery by avoiding dose dumping.The main reasonbehind the use of pulsatile delivery is provision ofconstant drug release where a zero-order release is notpreferred. Chronopharmacotherapy in colon targeting play its role bymany systems such ascapsular systems, pulsatile system and osmotic systems, which are based on use of rupturable membranes and biodegradable polymers.The objective of this review article is to provide latest knowledge about drugs with chrono-pharmacological behavior entails night time dosing specially to the colon.

Anti-Mullerian hormone levels do not predict response to pulsatile GnRH in women with hypothalamic amenorrhea.

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Billington, Emma O; Corenblum, Bernard

2016-09-01

Pulsatile GnRH is used to induce ovulation in women with hypothalamic amenorrhea (HA), but tools to predict response are lacking. We assessed whether baseline AMH levels are associated with response to pulsatile GnRH in 16 women with HA. AMH levels were compared between non-responders and women who achieved follicular development or pregnancy. Median AMH for the cohort was 2.2 ng/mL. AMH levels were undetectable or low in four women, normal in nine and high in three. Follicular development was observed in 13 (81%) women (82% of cycles) and pregnancy achieved in 10 (63%) women (29% of cycles). All four women with low or undetectable AMH had follicular response and three achieved pregnancy. Of the 12 women with normal or high AMH, 10 had a follicular response and seven achieved pregnancy. Median AMH levels were comparable in those who achieved follicular development and those who did not (2.2 ng/mL versus 1.3 ng/mL, p = 0.78) and in those who became pregnant and those who did not (2.2 ng/mL versus 1.9 ng/mL, p = 0.52). In summary, low AMH does not preclude response to ovulation induction in women with HA, suggesting that ovarian potential may not be the primary determinant of AMH concentrations in this population.

Modeling of pulsatile flow-dependent nitric oxide regulation in a realistic microvascular network.

Science.gov (United States)

Wang, Ruofan; Pan, Qing; Kuebler, Wolfgang M; Li, John K-J; Pries, Axel R; Ning, Gangmin

2017-09-01

Hemodynamic pulsatility has been reported to regulate microcirculatory function. To quantitatively assess the impact of flow pulsatility on the microvasculature, a mathematical model was first developed to simulate the regulation of NO production by pulsatile flow in the microcirculation. Shear stress and pressure pulsatility were selected as regulators of endothelial NO production and NO-dependent vessel dilation as feedback to control microvascular hemodynamics. The model was then applied to a real microvascular network of the rat mesentery consisting of 546 microvessels. As compared to steady flow conditions, pulsatile flow increased the average NO concentration in arterioles from 256.8±93.1nM to 274.8±101.1nM (Pflow as compared to steady flow conditions. Network perfusion and flow heterogeneity were improved under pulsatile flow conditions, and vasodilation within the network was more sensitive to heart rate changes than pulse pressure amplitude. The proposed model simulates the role of flow pulsatility in the regulation of a complex microvascular network in terms of NO concentration and hemodynamics under varied physiological conditions. Copyright © 2017 Elsevier Inc. All rights reserved.

A durability study of a paracorporeal pulsatile electro-mechanical pneumatic biventricular assist device.

Science.gov (United States)

Choi, Hyuk; Lee, Heung-Man; Nam, Kyoung Won; Choi, Jaesoon; Lee, Jung-Joo; Kim, Ho Chul; Song, Seung Joon; Ahn, Chi Bum; Son, Ho Sung; Lim, Choon Hak; Son, Kuk Hui; Park, Yong Doo; Jeong, Gi Seok; Sun, Kyung

2011-06-01

In 2002, the paracorporeal pulsatile electro-mechanical pneumatic ventricular assist device (VAD) began to be developed by the Korea Artificial Organ Center at Korea University under a Health & Medical Technology Research and Development program which finished in 2008. In vitro durability testing was conducted on the paracorporeal pulsatile pneumatic VAD to determine device durability and to evaluate device failures. The 1- and 2-year reliability of the paracorporeal pulsatile pneumatic VAD was shown to be 91.2% and 54.9%, respectively, with an 80% confidence level. Failure modes were analyzed using fault tree analysis, with customized software continuously acquiring data during the test period. After this period, 21 in vivo animal tests were done, with 14 cases of left atrium to left ventricle (LV) inflow cannulation (36Fr)/outflow grafting to descending aorta, and seven cases of apex cannulation of LV to descending aorta (12 mm). The longest postoperative day (182 days) in Korea was recently recorded in in vivo animal testing (bovine, 90 kg, male, 3.5-4.0 L/min flow rate, and 55 bpm). © 2011, Copyright the Authors. Artificial Organs © 2011, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Tonsillar pulsatility before and after surgical decompression for children with Chiari malformation type 1: an application for true fast imaging with steady state precession

International Nuclear Information System (INIS)

Radmanesh, Alireza; Greenberg, Jacob K.; Smyth, Matthew D.; Limbrick, David D.; Chatterjee, Arindam; Sharma, Aseem

2015-01-01

We hypothesize that surgical decompression for Chiari malformation type 1 (CM-1) is associated with statistically significant decrease in tonsillar pulsatility and that the degree of pulsatility can be reliably assessed regardless of the experience level of the reader. An Institutional Review Board (IRB)-approved Health Insurance Portability and Accountability Act (HIPAA)-compliant retrospective study was performed on 22 children with CM-1 (8 males; mean age 11.4 years) who had cardiac-gated true-FISP sequence and phase-contrast cerebrospinal fluid (CSF) flow imaging as parts of routine magnetic resonance (MR) imaging before and after surgical decompression. The surgical technique (decompression with or without duraplasty) was recorded for each patient. Three independent radiologists with different experience levels assessed tonsillar pulsatility qualitatively and quantitatively and assessed peritonsillar CSF flow qualitatively. Results were analyzed. To evaluate reliability, Fleiss kappa for multiple raters on categorical variables and intra-class correlation for agreement in pulsatility ratings were calculated. After surgical decompression, the degree of tonsillar pulsatility appreciably decreased, confirmed by t test, both qualitatively (p values <0.001, <0.001, and 0.045 for three readers) and quantitatively (amount of decrease/p value for three readers 0.7 mm/<0.001, 0.7 mm/<0.001, and 0.5 mm/0.022). There was a better agreement among the readers in quantitative assessment of tonsillar pulsatility (kappa 0.753-0.834), compared to qualitative assessment of pulsatility (kappa 0.472-0.496) and qualitative assessment of flow (kappa 0.056 to 0.203). Posterior fossa decompression with duraplasty led to a larger decrease in tonsillar pulsatility, compared to posterior fossa decompression alone. Tonsillar pulsatility in CM-1 is significantly reduced after surgical decompression. Quantitative assessment of tonsillar pulsatility was more reliable across readers than

Tonsillar pulsatility before and after surgical decompression for children with Chiari malformation type 1: an application for true fast imaging with steady state precession

Energy Technology Data Exchange (ETDEWEB)

Radmanesh, Alireza [University of California, San Francisco, Department of Radiology and Biomedical Imaging, San Francisco, CA (United States); Washington University School of Medicine, Mallinckrodt Institute of Radiology, St Louis, MO (United States); Greenberg, Jacob K.; Smyth, Matthew D.; Limbrick, David D. [Washington University School of Medicine, Department of Neurosurgery, St Louis, MO (United States); Chatterjee, Arindam; Sharma, Aseem [Washington University School of Medicine, Mallinckrodt Institute of Radiology, St Louis, MO (United States)

2015-04-01

We hypothesize that surgical decompression for Chiari malformation type 1 (CM-1) is associated with statistically significant decrease in tonsillar pulsatility and that the degree of pulsatility can be reliably assessed regardless of the experience level of the reader. An Institutional Review Board (IRB)-approved Health Insurance Portability and Accountability Act (HIPAA)-compliant retrospective study was performed on 22 children with CM-1 (8 males; mean age 11.4 years) who had cardiac-gated true-FISP sequence and phase-contrast cerebrospinal fluid (CSF) flow imaging as parts of routine magnetic resonance (MR) imaging before and after surgical decompression. The surgical technique (decompression with or without duraplasty) was recorded for each patient. Three independent radiologists with different experience levels assessed tonsillar pulsatility qualitatively and quantitatively and assessed peritonsillar CSF flow qualitatively. Results were analyzed. To evaluate reliability, Fleiss kappa for multiple raters on categorical variables and intra-class correlation for agreement in pulsatility ratings were calculated. After surgical decompression, the degree of tonsillar pulsatility appreciably decreased, confirmed by t test, both qualitatively (p values <0.001, <0.001, and 0.045 for three readers) and quantitatively (amount of decrease/p value for three readers 0.7 mm/<0.001, 0.7 mm/<0.001, and 0.5 mm/0.022). There was a better agreement among the readers in quantitative assessment of tonsillar pulsatility (kappa 0.753-0.834), compared to qualitative assessment of pulsatility (kappa 0.472-0.496) and qualitative assessment of flow (kappa 0.056 to 0.203). Posterior fossa decompression with duraplasty led to a larger decrease in tonsillar pulsatility, compared to posterior fossa decompression alone. Tonsillar pulsatility in CM-1 is significantly reduced after surgical decompression. Quantitative assessment of tonsillar pulsatility was more reliable across readers than

Pulsatile pipe flow transition: Flow waveform effects

Science.gov (United States)

Brindise, Melissa C.; Vlachos, Pavlos P.

2018-01-01

Although transition is known to exist in various hemodynamic environments, the mechanisms that govern this flow regime and their subsequent effects on biological parameters are not well understood. Previous studies have investigated transition in pulsatile pipe flow using non-physiological sinusoidal waveforms at various Womersley numbers but have produced conflicting results, and multiple input waveform shapes have yet to be explored. In this work, we investigate the effect of the input pulsatile waveform shape on the mechanisms that drive the onset and development of transition using particle image velocimetry, three pulsatile waveforms, and six mean Reynolds numbers. The turbulent kinetic energy budget including dissipation rate, production, and pressure diffusion was computed. The results show that the waveform with a longer deceleration phase duration induced the earliest onset of transition, while the waveform with a longer acceleration period delayed the onset of transition. In accord with the findings of prior studies, for all test cases, turbulence was observed to be produced at the wall and either dissipated or redistributed into the core flow by pressure waves, depending on the mean Reynolds number. Turbulent production increased with increasing temporal velocity gradients until an asymptotic limit was reached. The turbulence dissipation rate was shown to be independent of mean Reynolds number, but a relationship between the temporal gradients of the input velocity waveform and the rate of turbulence dissipation was found. In general, these results demonstrated that the shape of the input pulsatile waveform directly affected the onset and development of transition.

Analyzing Cell Wall Elasticity After Hormone Treatment: An Example Using Tobacco BY-2 Cells and Auxin.

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Braybrook, Siobhan A

2017-01-01

Atomic force microscopy, and related nano-indentation techniques, is a valuable tool for analyzing the elastic properties of plant cell walls as they relate to changes in cell wall chemistry, changes in development, and response to hormones. Within this chapter I will describe a method for analyzing the effect of the phytohormone auxin on the cell wall elasticity of tobacco BY-2 cells. This general method may be easily altered for different experimental systems and hormones of interest.

Effect of Acute Resistance Exercise on Carotid Artery Stiffness and Cerebral Blood Flow Pulsatility

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Wesley K Lefferts

2014-03-01

Full Text Available Arterial stiffness is associated with cerebral flow pulsatility. Arterial stiffness increases following acute resistance exercise (RE. Whether this acute RE-induced vascular stiffening affects cerebral pulsatility remains unknown. Purpose: To investigate the effects of acute RE on common carotid artery (CCA stiffness and cerebral blood flow velocity (CBFv pulsatility. Methods: Eighteen healthy men (22 ± 1 yr; 23.7 ± 0.5 kg∙m-2 underwent acute RE (5 sets, 5-RM bench press, 5 sets 10-RM bicep curls with 90 s rest intervals or a time control condition (seated rest in a randomized order. CCA stiffness (β-stiffness, Elastic Modulus (Ep and hemodynamics (pulsatility index, forward wave intensity and reflected wave intensity were assessed using a combination of Doppler ultrasound, wave intensity analysis and applanation tonometry at baseline and 3 times post-RE. CBFv pulsatility index was measured with transcranial Doppler at the middle cerebral artery (MCA. Results: CCA β-stiffness, Ep and CCA pulse pressure significantly increased post-RE and remained elevated throughout post-testing (p 0.05. There were significant increases in forward wave intensity post-RE (p0.05. Conclusion: Although acute RE increases CCA stiffness and pressure pulsatility, it may not affect CCA or MCA flow pulsatility. Increases in pressure pulsatility may be due to increased forward wave intensity and not pressure from wave reflections.

Cerebral blood flow and intracranial pulsatility studied with MRI: measurement, physiological and pathophysiological aspects

International Nuclear Information System (INIS)

Waahlin, Anders

2012-01-01

During each cardiac cycle pulsatile arterial blood inflates the vascular bed of the brain, forcing cerebrospinal fluid (CSF) and venous blood out of the cranium. Excessive arterial pulsatility may be part of a harmful mechanism causing cognitive decline among elderly. Additionally, restricted venous flow from the brain is suggested as the cause of multiple sclerosis. Addressing hypotheses derived from these observations requires accurate and reliable investigational methods. This work focused on assessing the pulsatile waveform of cerebral arterial, venous and CSF flows. The overall aim of this dissertation was to explore cerebral blood flow and intracranial pulsatility using MRI, with respect to measurement, physiological and pathophysiological aspects.Two-dimensional phase contrast magnetic resonance imaging (2D PCMRI) was used to assess the pulsatile waveforms of cerebral arterial, venous and CSF flow. The repeatability was assessed in healthy young subjects. The 2D PCMRI measurements of cerebral arterial, venous and CSF pulsatility were generally repeatable but the pulsatility decreased systematically during the investigation. A method combining 2D PCMRI measurements with invasive CSF infusion tests to determine the magnitude and distribution of compliance within the craniospinal system was developed and applied in a group of healthy elderly. The intracranial space contained approximately two thirds of the total craniospinal compliance. The magnitude of craniospinal compliance was less than suggested in previous studies. The vascular hypothesis for multiple sclerosis was tested. Venous drainage in the internal jugular veins was compared between healthy controls and multiple sclerosis patients using 2D PCMRI. For both groups, a great variability in the internal jugular flow was observed but no pattern specific to multiple sclerosis could be found. Relationships between regional brain volumes and potential biomarkers of intracranial cardiac-related pulsatile

Cerebral blood flow and intracranial pulsatility studied with MRI: measurement, physiological and pathophysiological aspects

Energy Technology Data Exchange (ETDEWEB)

Waahlin, Anders

2012-07-01

During each cardiac cycle pulsatile arterial blood inflates the vascular bed of the brain, forcing cerebrospinal fluid (CSF) and venous blood out of the cranium. Excessive arterial pulsatility may be part of a harmful mechanism causing cognitive decline among elderly. Additionally, restricted venous flow from the brain is suggested as the cause of multiple sclerosis. Addressing hypotheses derived from these observations requires accurate and reliable investigational methods. This work focused on assessing the pulsatile waveform of cerebral arterial, venous and CSF flows. The overall aim of this dissertation was to explore cerebral blood flow and intracranial pulsatility using MRI, with respect to measurement, physiological and pathophysiological aspects.Two-dimensional phase contrast magnetic resonance imaging (2D PCMRI) was used to assess the pulsatile waveforms of cerebral arterial, venous and CSF flow. The repeatability was assessed in healthy young subjects. The 2D PCMRI measurements of cerebral arterial, venous and CSF pulsatility were generally repeatable but the pulsatility decreased systematically during the investigation. A method combining 2D PCMRI measurements with invasive CSF infusion tests to determine the magnitude and distribution of compliance within the craniospinal system was developed and applied in a group of healthy elderly. The intracranial space contained approximately two thirds of the total craniospinal compliance. The magnitude of craniospinal compliance was less than suggested in previous studies. The vascular hypothesis for multiple sclerosis was tested. Venous drainage in the internal jugular veins was compared between healthy controls and multiple sclerosis patients using 2D PCMRI. For both groups, a great variability in the internal jugular flow was observed but no pattern specific to multiple sclerosis could be found. Relationships between regional brain volumes and potential biomarkers of intracranial cardiac-related pulsatile

Endocrine dynamics during pulsatile GnRH administration in patients with hypothalamic amenorrhea and polycystic ovarian disease.

Science.gov (United States)

Rossmanith, W G; Wirth, U; Benz, R; Wolf, A S

1989-01-01

The LH secretory patterns and ovarian endocrine responses have been determined during pulsatile gonadotropin-releasing hormone (GnRH) administration for induction of ovulation in patients with hypothalamic amenorrhea (HA). However, until now these endocrine dynamics during GnRH therapy have not been thoroughly investigated in patients with polycystic ovarian disease (PCOD). Seven patients with HA and 4 patients with PCOD have therefore been studied to determine changes in LH pulsatile activity and in serum sex steroid levels in response to chronic intermittent GnRH stimulation. GnRH was administered intravenously (5-10 micrograms/90 minutes) by means of a portable infusion pump. Blood samples were obtained at 15-minute intervals for 4 hours on the day before the start of GnRH stimulation (control day) and on treatment days 5, 10 and 15. LH was determined in all samples and FSH, serum androgens and estrogens were measured in baseline samples by RIA. While 8 (62%) ovulations and 5 conceptions were observed in 13 treatment cycles in patients with HA, no ovulations were achieved during 9 treatment cycles in patients with PCOD. On the control day significantly (p less than 0.05) higher basal LH and testosterone (T) levels and significantly (p less than 0.05) lower FSH levels were found in the PCOD patients. The LH pulsatile profiles of the PCOD patients showed significantly (p less than 0.05) higher pulse amplitudes and areas under the curve (integrated responses). Pulsatile GnRH administration induced a significant (p less than 0.05) increase in LH pulse amplitudes in both HA and PCOD patients, and also increased (p less than 0.05) the integrated responses in patients with HA. During the GnRH stimulation, the LH interpulse intervals of both HA and PCOD patients were found to be similar to the frequency in which exogenous GnRH was administered. FSH levels rose continuously (p less than 0.001) during stimulation in patients with HA, but remained unchanged in patients

Recent Advancement and Technological Aspects of Pulsatile Drug Delivery System - A Laconic Review.

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Pandit, Vinay; Kumar, Ajay; Ashawat, Mahendra S; Verma, Chander P; Kumar, Pravin

2017-01-01

Pulsatile drug delivery system (PDDS) shows potential significance in the field of drug delivery to release the maximum amount of drug at a definite site and at specific time. PDDS are mainly time controlled delivery devices having a definite pause period for drug release, which is not affected by acidity, alkalinity, motility and enzymes present in the gastrointestinal tract. Pulsatile medication possess the potential to deliver the drugs in the therapy of diseases where drug dose is essential during sleep, drugs having greater first pass metabolism and absorption at precise location in digestive tract. The review article, discuss the general concepts, marketed formulations and patents or any other recent advancement in pulsatile release technology. It also highlights on diseases requiring therapy by pulsatile release, various researches on herbal pulsatile formulations and quality control aspects of PDDS. Pulsatile medication possess the potential to deliver the drugs in the therapy of diseases where drug dose is essential during sleep, drugs having greater first pass metabolism and absorption at precise location in digestive tract. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Pulsatile versus steady infusions for hepatic artery chemotherapy

International Nuclear Information System (INIS)

Kim, E.E.; Haynie, T.P.; Wright, K.C.; Chaynsangavej, C.; Gianturco, C.; Lamki, L.; Wallace, S.

1984-01-01

Hepatic artery chemotherapy for unresectable liver tumors requires an even distribution of the drugs in the tumor or vascular bed. This cannot be determined angiographically because the drugs are infused at a much lower rate than the contrast media. It is easy, however, to determine the quality of the perfusion by injecting a small volume of Tc-99m MAA in one of the side ports while chemotherapeutic agent is being infused at the same rate. Usually this shows a uniform, satisfactory distribution of isotope. Occasionally, however, some areas fail to receive Tc-99m in spite of what appears to be a good position of the catheter tip. Since ''streaming'' of the infused drugs has been blamed for their uneven distribution, the authors decided to compare the usual steady flow infusions with infusions made pulsatile by the addition of a pulsing device (Gianturco Pump) attached to the infusion tubing. Eighty-three patients were studied with steady as well as pulsatile infusions. In 16 of these patients the perfusion pattern was definitely changed by the pulsatile infusion. In one patient the pulsatile mode resulted in an unwanted gastric perfusion. In 5 patients the distribution was improved in one hepatic lobe and in 10 patients it was improved in both lobes. These results show that hepatic artery perfusions can occasionally be improved by pulsing the infusate. However, pulsing can produce the unwanted perfusion of extra-hepatic areas

Leptin does not mediate short-term fasting-induced changes in growth hormone pulsatility but increases IGF-I in leptin deficiency states.

Science.gov (United States)

Chan, Jean L; Williams, Catherine J; Raciti, Patricia; Blakeman, Jennifer; Kelesidis, Theodore; Kelesidis, Iosif; Johnson, Michael L; Thorner, Michael O; Mantzoros, Christos S

2008-07-01

States of acute and chronic energy deficit are characterized by increased GH secretion and decreased IGF-I levels. The objective of the study was to determine whether changes in levels of leptin, a key mediator of the adaptation to starvation, regulate the GH-IGF system during energy deficit. We studied 14 healthy normal-weight men and women during three conditions: baseline fed and 72-h fasting (to induce hypoleptinemia) with administration of placebo or recombinant methionyl human leptin (r-metHuLeptin) (to reverse the fasting associated hypoleptinemia). We also studied eight normal-weight women with exercise-induced chronic energy deficit and hypothalamic amenorrhea at baseline and during 2-3 months of r-metHuLeptin treatment. GH pulsatility, IGF levels, IGF and GH binding protein (GHBP) levels were measured. During short-term energy deficit, measures of GH pulsatility and disorderliness and levels of IGF binding protein (IGFBP)-1 increased, whereas leptin, insulin, IGF-I (total and free), IGFBP-4, IGFBP-6, and GHBP decreased; r-metHuLeptin administration blunted the starvation-associated decrease of IGF-I. In chronic energy deficit, total and free IGF-I, IGFBP-6, and GHBP levels were lower, compared with euleptinemic controls; r-metHuLeptin administration had no major effect on GH pulsatility after 2 wk but increased total IGF-I levels and tended to increase free IGF-I and IGFBP-3 after 1 month. The GH/IGF system changes associated with energy deficit are largely independent of leptin deficiency. During acute energy deficit, r-metHuLeptin administration in replacement doses blunts the starvation-induced decrease of IGF-I, but during chronic energy deficit, r-metHuLeptin administration increases IGF-I and tends to increase free IGF-I and IGFBP-3.

Investigation of the pulsatile pipe flow

Czech Academy of Sciences Publication Activity Database

Adamec, J.; Nožička, J.; Kořenář, Josef

2000-01-01

Roč. 18, č. 2 (2000), s. 17-22 ISSN 0392-8764 Institutional research plan: CEZ:AV0Z2060917 Keywords : pulsatile flow * laminar-turbulent transition * reynolds normal stress Subject RIV: BK - Fluid Dynamics

Obesity, growth hormone and exercise.

Science.gov (United States)

Thomas, Gwendolyn A; Kraemer, William J; Comstock, Brett A; Dunn-Lewis, Courtenay; Maresh, Carl M; Volek, Jeff S

2013-09-01

Growth hormone (GH) is regulated, suppressed and stimulated by numerous physiological stimuli. However, it is believed that obesity disrupts the physiological and pathological factors that regulate, suppress or stimulate GH release. Pulsatile GH has been potently stimulated in healthy subjects by both aerobic and resistance exercise of the right intensity and duration. GH modulates fuel metabolism, reduces total fat mass and abdominal fat mass, and could be a potent stimulus of lipolysis when administered to obese individuals exogenously. Only pulsatile GH has been shown to augment adipose tissue lipolysis and, therefore, increasing pulsatile GH response may be a therapeutic target. This review discusses the factors that cause secretion of GH, how obesity may alter GH secretion and how both aerobic and resistance exercise stimulates GH, as well as how exercise of a specific intensity may be used as a stimulus for GH release in individuals who are obese. Only five prior studies have investigated exercise as a stimulus of endogenous GH in individuals who are obese. Based on prior literature, resistance exercise may provide a therapeutic target for releasing endogenous GH in individuals who are obese if specific exercise programme variables are utilized. Biological activity of GH indicates that this may be an important precursor to beneficial changes in body fat and lean tissue mass in obese individuals. However, additional research is needed including what molecular GH variants are acutely released and involved at target tissues as a result of different exercise stimuli and what specific exercise programme variables may serve to stimulate GH in individuals who are obese.

Loss of inverse relationship between pulsatile insulin and glucagon secretion in patients with type 2 diabetes

DEFF Research Database (Denmark)

Menge, Björn A; Grüber, Lena; Jørgensen, Signe M

2011-01-01

In patients with type 2 diabetes, glucagon levels are often increased. Furthermore, pulsatile secretion of insulin is disturbed in such patients. Whether pulsatile glucagon secretion is altered in type 2 diabetes is not known.......In patients with type 2 diabetes, glucagon levels are often increased. Furthermore, pulsatile secretion of insulin is disturbed in such patients. Whether pulsatile glucagon secretion is altered in type 2 diabetes is not known....

The use of a combined regimen of GnRH agonist plus a low-dose oral contraceptive improves the spontaneous pulsatile LH secretory characteristics in patients with polycycstic ovary disease after discontinuation of treatment.

Science.gov (United States)

Genazzani, A D; Battaglia, C; Gamba, O; Petraglia, F; Malavasi, B; Genazzani, A R

2000-05-01

The fertility rate in women with polycystic ovary disease (PCOD) is influenced by the type of treatment received. The present study evaluated the possible correlation between treatment and pulsatile release of gonadotropins. Spontaneous episodic secretion of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) and hormonal parameters were monitored before and after 1, 3, and 6 months after treatments suspension. Twenty-four PCOD patients were randomly divided into two groups of 12 subjects. Group A was treated with gonadotropin-releasing hormone (GnRH)-analogue plus oral contraceptive (OC). Group B was treated only with OC. Both groups were treated for 6 months and followed up for 6 months. In all subjects the therapeutic regimens reduced the androgenic milieau and the gonadotropin plasma levels. Spontaneous pulsatile secretion of LH and FSH was significantly modified in both groups, but patients who received the combined regimen showed a significantly greater reduction of LH plasma levels and a significantly greater decrease of LH pulse amplitude throughout the 6 months after treatment suspension. Ferriman-Gallway score and ovarian volumes were significantly reduced in patients who received the combined treatment than in the OC-treated patients. These data support the evidence of a higher efficacy of the combination of GnRH-a + OC than OC alone in restoring a normal and adequate spontaneous episodic gonadotropin discharge and in decreasing Ferriman-Gallway score and ovarian volumes in patients with PCOD.

Heat Transfer to Pulsatile Slip Flow in a Porous Channel Filled With ...

African Journals Online (AJOL)

This paper investigate the effect of slip on the hydromagnetic pulsatile flow through a porous channel filled with saturated porous medium with time dependent boundary condition on the heated wall. Based on the pulsatile flow nature, the dimensionless flow governing equations are resolved to harmonic and non-harmonic ...

Cerebrovascular blood oxygenation level dependent pulsatility at baseline and following acute exercise among healthy adolescents.

Science.gov (United States)

Theyers, Athena E; Goldstein, Benjamin I; Metcalfe, Arron Ws; Robertson, Andrew D; MacIntosh, Bradley J

2018-01-01

Arterial stiffness is linked to cerebral small vessel damage and neurodegeneration, but barriers to accessing deep cerebrovascular anatomy limit our ability to assess the brain. This study describes an adaptation of a cardiac-related scrubbing method as a means of generating blood oxygenation level-dependent pulsatility maps based on the cardiac cycle. We examine BOLD pulsatility at rest, based on the non-parametric deviation from null metric, as well as changes following acute physiological stress from 20 min of moderate-intensity cycling in 45 healthy adolescents. We evaluate the influence of repetition time (TR) and echo time (TE) using simulated and multi-echo empirical data, respectively. There were tissue-specific and voxel-wise BOLD pulsatility decreases 20 min following exercise cessation. BOLD pulsatility detection was comparable over a range of TR and TE values when scan volumes were kept constant; however, short TRs (≤500 ms) and TEs (∼14 ms) acquisitions would yield the most efficient detection. Results suggest cardiac-related BOLD pulsatility may represent a robust and easily adopted method of mapping cerebrovascular pulsatility with voxel-wise resolution.

Changes in Bone Mineral Density and Metabolic Parameters after Pulsatile Gonadorelin Treatment in Young Men with Hypogonadotropic Hypogonadism

Directory of Open Access Journals (Sweden)

Chen-Xi Li

2015-01-01

Full Text Available To assess the prevalence of osteoporosis in young men with hypogonadotropic hypogonadism (HH and to investigate the changes of BMD and metabolic parameters, a total of 22 young male patients with HH and 20 healthy controls were enrolled in the study. BMD, biochemical, and hormonal parameters were measured in two groups. Osteoporosis was more prevalent in HH patients (45.45% than the control subjects (10.00% (P<0.001. The patients with HH had lower BMD in lumbar spine 2–4, femoral neck, and total hip (P<0.001, for all and higher fasting insulin (P=0.001, HOMA-IR (P=0.002, and SHBG (P<0.001 compared to the controls. After 6 months of pulsatile gonadorelin treatment, BMI (P=0.021 and BMD in lumbar spine 2–4, femoral neck, and total hip (P=0.002, P=0.003, and P=0.003, resp. increased dramatically and total cholesterol (P=0.034, fasting insulin (P=0.025, HOMA-IR (P=0.021, and SHBG (P=0.001 decreased significantly in HH patients. The study shows a higher prevalence of osteoporosis in young men with HH. Long-term pulsatile gonadorelin treatment indicates a positive effect on BMD and metabolic parameters of HH patients.

Gonadotropin-releasing hormone for infertility in women with primary hypothalamic amenorrhea. Toward a more-interventional approach.

Science.gov (United States)

Kesrouani, A; Abdallah, M A; Attieh, E; Abboud, J; Atallah, D; Makhoul, C

2001-01-01

To assess the effectiveness of a protocol of pulsatile gonadotropin releasing-hormone (GnRH) in treating infertility in women with primary hypothalamic amenorrhea. Retrospective analysis of 44 cycles treated at an infertility center. Twenty-four patients with primary hypothalamic amenorrhea were treated intravenously with pulsatile GnRH using 5 micrograms per bolus every 90 minutes. Ultrasound monitoring and cervical assessment by Insler's scoring system allowed timed injection of human chorionic gonadotropin (hCG) and intrauterine insemination if needed. Luteal support was provided with hCG. The ovulation rate was 95% with the 5-microgram dose. A single follicle was produced in 91% of cycles. The overall pregnancy rate per ovulatory cycle was 45%, and the pregnancy rate per patient was 83%. In patients treated previously with exogenous gonadotropins, poor results were observed. Only one case of mild overstimulation was reported. Pulsatile GnRH is an effective and safe method of treating infertility in women with primary hypothalamic amenorrhea, thus simulating normal ovulation; however, more-interventional management, including the qualitative estrogenic response, may lead to optimal results and increase the pregnancy rate.

Observation of the CSF pulsatile flow in the aqueduct using cine MRI with presaturation bolus tracking, 3

International Nuclear Information System (INIS)

Nakajima, Satoshi

1992-01-01

The to-and-fro motion patterns of the CSF flow in the aqueduct in ten normal adults, ten patients with secondary normal-pressure hydrocephalus (NPH), and fourteen patients with idiopathic ventriculomegaly were analyzed using cine MRI with presaturation bolus tracking. The to-and-fro motion patterns of the CSF flow in the aqueduct were thus classified into four types according to their maximum velocity and the relative time duration of their flow in the rostral and caudal directions. The correlation between the clinical symptoms, the CT findings, the RI-cisternography findings, the results of the ICP monitorings, and the CSF pulsatile-flow patterns were then analyzed. In secondary NPH disclosing frequent B waves on ICP monitoring, the maximum velocity of the CSF flow in the aqueduct was over 15 mm/sec, and the duration of the CSF flow was longer in the caudal direction than in the rostral direction. Furthermore, the faster the maximum velocity of the CSF flow, the larger the ventricular size on CT and the more severe the CSF malabsorption on cisternography. In idiopathic ventriculomegaly, only two cases demonstrated the same CSF flow pattern as was shown in secondary NPH; the other cases demonstrated other CSF flow patterns, which were considered to indicate hydrocephalus ex vacuo or arrested hydrocephalus. The CSF pulsatile-flow pattern was assumed to change according to the degree of the CSF circulatory disorder, its compensatory process, and the plasticity of the brain. The investigation of the CSF pulsatile flow gives important information for the evaluation of various hydrocephalic conditions. (author)

Effects of acute aerobic exercise on arterial stiffness and cerebrovascular pulsatility in adults with and without hypertension.

Science.gov (United States)

Lefferts, Wesley K; DeBlois, Jacob P; Receno, Candace N; Barreira, Tiago V; Brutsaert, Tom D; Carhart, Robert L; Heffernan, Kevin S

2018-04-19

Stiffer central arteries, as seen in hypertension (HTN), foster transmission of pulsatile hemodynamics into fragile cerebral vessels. Aerobic exercise is recommended for adults with HTN, but its effects on arterial stiffness and pulsatility in this group are unclear. This study sought to investigate the effect of acute aerobic exercise on arterial stiffness and cerebrovascular pulsatility in 30 adults with treated HTN and 30 age, sex, and BMI-matched adults without HTN (56 ± 6 years, BMI 28.2 ± 2.9 kg/m; 28 women). Patients underwent hemodynamic measures before/after 30-min cycling (≈55% peak oxygen consumption). Aortic stiffness was measured using carotid-femoral pulse wave velocity, and carotid artery stiffness was assessed with β-stiffness via ultrasound. Aortic/carotid pulse pressure (aortic via radial generalized transfer function) was measured by tonometry and calibrated to brachial mean pressure and diastolic pressure. Carotid/middle cerebral artery (MCA) blood velocity pulsatility indices were measured using Doppler. Carotid wave intensity analysis was used to derive forward wave intensity (W1). Exercise impacted hemodynamics similarly in HTN compared to no-HTN. Carotid-femoral pulse wave velocity, MCA pulsatility index, carotid pulsatility index, and W1 increased similarly after exercise in both groups (P < 0.05). Carotid pulse pressure and β-stiffness were unaltered after exercise. Postexercise changes in W1 were positively associated with carotid pulsatility index, which was further associated with MCA pulsatility index. These data suggest adults with treated HTN experience similar increases in aortic stiffness and cerebrovascular hemodynamic pulsatility during early recovery from acute aerobic exercise as their counterparts without HTN.

Non-invasive assessment of pulsatile intracranial pressure with phase-contrast magnetic resonance imaging.

Directory of Open Access Journals (Sweden)

Geir Ringstad

Full Text Available Invasive monitoring of pulsatile intracranial pressure can accurately predict shunt response in patients with idiopathic normal pressure hydrocephalus, but may potentially cause complications such as bleeding and infection. We tested how a proposed surrogate parameter for pulsatile intracranial pressure, the phase-contrast magnetic resonance imaging derived pulse pressure gradient, compared with its invasive counterpart. In 22 patients with suspected idiopathic normal pressure hydrocephalus, preceding invasive intracranial pressure monitoring, and any surgical shunt procedure, we calculated the pulse pressure gradient from phase-contrast magnetic resonance imaging derived cerebrospinal fluid flow velocities obtained at the upper cervical spinal canal using a simplified Navier-Stokes equation. Repeated measurements of the pulse pressure gradient were also undertaken in four healthy controls. Of 17 shunted patients, 16 responded, indicating high proportion of "true" normal pressure hydrocephalus in the patient cohort. However, there was no correlation between the magnetic resonance imaging derived pulse pressure gradient and pulsatile intracranial pressure (R = -.18, P = .43. Pulse pressure gradients were also similar in patients and healthy controls (P = .26, and did not differ between individuals with pulsatile intracranial pressure above or below established thresholds for shunt treatment (P = .97. Assessment of pulse pressure gradient at level C2 was therefore not found feasible to replace invasive monitoring of pulsatile intracranial pressure in selection of patients with idiopathic normal pressure hydrocephalus for surgical shunting. Unlike invasive, overnight monitoring, the pulse pressure gradient from magnetic resonance imaging comprises short-term pressure fluctuations only. Moreover, complexity of cervical cerebrospinal fluid flow and -pulsatility at the upper cervical spinal canal may render the pulse pressure gradient a poor surrogate

MR imaging of pulsatile CSF movement in hydrocephalus communicans before and after CSF shunt implantation

International Nuclear Information System (INIS)

Goldmann, A.; Kunz, U.; Rotermund, F.; Friedrich, J.M.; Schnarkowski, P.

1992-01-01

16 patients with hydrocephalus communicans and 5 healthy volunteers were examined to demonstrate the pattern of the pulsatile CSF flow. After implantation of a CSF shunt system the same patients were examined again to show the influence of the shunt on the CSF pulsations. We used a flow-sensitised, cardiac-gated 2D FLASH sequence and analysed the phase and magnitude images. It could be shown that most patients (n=12) had a hyerdynamic pulsatile flow preoperatively. After shunt implantation the pulsatile CSF motion and the clinical symptoms were improved in 8 of these patients. MRI of pulsatile CSF flow movement seems to be a helpful noninvasive tool to estimate the prognosis of a shunt implantation in patients with hydrocephalus communicans. (orig.) [de

Non-dimensional physics of pulsatile cardiovascular networks and energy efficiency.

Science.gov (United States)

Yigit, Berk; Pekkan, Kerem

2016-01-01

In Nature, there exist a variety of cardiovascular circulation networks in which the energetic ventricular load has both steady and pulsatile components. Steady load is related to the mean cardiac output (CO) and the haemodynamic resistance of the peripheral vascular system. On the other hand, the pulsatile load is determined by the simultaneous pressure and flow waveforms at the ventricular outlet, which in turn are governed through arterial wave dynamics (transmission) and pulse decay characteristics (windkessel effect). Both the steady and pulsatile contributions of the haemodynamic power load are critical for characterizing/comparing disease states and for predicting the performance of cardiovascular devices. However, haemodynamic performance parameters vary significantly from subject to subject because of body size, heart rate and subject-specific CO. Therefore, a 'normalized' energy dissipation index, as a function of the 'non-dimensional' physical parameters that govern the circulation networks, is needed for comparative/integrative biological studies and clinical decision-making. In this paper, a complete network-independent non-dimensional formulation that incorporates pulsatile flow regimes is developed. Mechanical design variables of cardiovascular flow systems are identified and the Buckingham Pi theorem is formally applied to obtain the corresponding non-dimensional scaling parameter sets. Two scaling approaches are considered to address both the lumped parameter networks and the distributed circulation components. The validity of these non-dimensional number sets is tested extensively through the existing empirical allometric scaling laws of circulation systems. Additional validation studies are performed using a parametric numerical arterial model that represents the transmission and windkessel characteristics, which are adjusted to represent different body sizes and non-dimensional haemodynamic states. Simulations demonstrate that the proposed non

Development of a gastroretentive pulsatile drug delivery platform.

Science.gov (United States)

Thitinan, Sumalee; McConville, Jason T

2012-04-01

To develop a novel gastroretentive pulsatile drug delivery platform by combining the advantages of floating dosage forms for the stomach and pulsatile drug delivery systems. A gastric fluid impermeable capsule body was used as a vessel to contain one or more drug layer(s) as well as one or more lag-time controlling layer(s). A controlled amount of air was sealed in the innermost portion of the capsule body to reduce the overall density of the drug delivery platform, enabling gastric floatation. An optimal mass fill inside the gastric fluid impermeable capsule body enabled buoyancy in a vertical orientation to provide a constant surface area for controlled erosion of the lag-time controlling layer. The lag-time controlling layer consisted of a swellable polymer, which rapidly formed a gel to seal the mouth of capsule body and act as a barrier to gastric fluid ingress. By varying the composition of the lag-time controlling layer, it was possible to selectively program the onset of the pulsatile delivery of a drug. This new delivery platform offers a new method of delivery for a variety of suitable drugs targeted in chronopharmaceutical therapy. This strategy could ultimately improve drug efficacy and patient compliance, and reduce harmful side effects by scaling back doses of drug administered. © 2012 The Authors. JPP © 2012 Royal Pharmaceutical Society.

Increasing awareness with recognition of pulsatile tinnitus for nurse practitioners in the primary care setting: A case study.

Science.gov (United States)

Vecchiarelli, Kelly; Amar, Arun Paul; Emanuele, Donna

2017-09-01

Pulsatile tinnitus is a whooshing sound heard synchronous with the heartbeat. It is an uncommon symptom affecting fewer than 10% of patients with tinnitus. It often goes unrecognized in the primary care setting. Failure to recognize this symptom can result in a missed or delayed diagnosis of a potentially life-threatening condition known as a dural arteriovenous fistula. The purpose of this case study is to provide a structured approach to the identification of pulsatile tinnitus and provide management recommendations. A case study and review of pertinent literature. Pulsatile tinnitus usually has a vascular treatable cause. A comprehensive history and physical examination will alert the nurse practitioner (NP) when pulsatile tinnitus is present. Auscultation in specific areas of the head can detect audible or objective pulsatile tinnitus. Pulsatile tinnitus that is audible to the examiner is an urgent medical condition requiring immediate consultation and referral. Knowledge of pulsatile tinnitus and awareness of this often treatable condition directs the NP to perform a detailed assessment when patients present with tinnitus, directs appropriate referral for care and treatment, and can reduce the risk of delayed or missed diagnosis. ©2017 American Association of Nurse Practitioners.

Force Trends and Pulsatility for Catheter Contact Identification in Intracardiac Electrograms during Arrhythmia Ablation.

Science.gov (United States)

Rivas-Lalaleo, David; Muñoz-Romero, Sergio; Huerta, Mónica; Erazo-Rodas, Mayra; Sánchez-Muñoz, Juan José; Rojo-Álvarez, José Luis; García-Alberola, Arcadi

2018-05-02

The intracardiac electrical activation maps are commonly used as a guide in the ablation of cardiac arrhythmias. The use of catheters with force sensors has been proposed in order to know if the electrode is in contact with the tissue during the registration of intracardiac electrograms (EGM). Although threshold criteria on force signals are often used to determine the catheter contact, this may be a limited criterion due to the complexity of the heart dynamics and cardiac vorticity. The present paper is devoted to determining the criteria and force signal profiles that guarantee the contact of the electrode with the tissue. In this study, we analyzed 1391 force signals and their associated EGM recorded during 2 and 8 s, respectively, in 17 patients (82 ± 60 points per patient). We aimed to establish a contact pattern by first visually examining and classifying the signals, according to their likely-contact joint profile and following the suggestions from experts in the doubtful cases. First, we used Principal Component Analysis to scrutinize the force signal dynamics by analyzing the main eigen-directions, first globally and then grouped according to the certainty of their tissue-catheter contact. Second, we used two different linear classifiers (Fisher discriminant and support vector machines) to identify the most relevant components of the previous signal models. We obtained three main types of eigenvectors, namely, pulsatile relevant, non-pulsatile relevant, and irrelevant components. The classifiers reached a moderate to sufficient discrimination capacity (areas under the curve between 0.84 and 0.95 depending on the contact certainty and on the classifier), which allowed us to analyze the relevant properties in the force signals. We conclude that the catheter-tissue contact profiles in force recordings are complex and do not depend only on the signal intensity being above a threshold at a single time instant, but also on time pulsatility and trends. These

Superior vena cava syndrome after pulsatile bidirectional Glenn shunt procedure: Perioperative implications

Directory of Open Access Journals (Sweden)

Neema Praveen

2009-01-01

Full Text Available Bidirectional superior cavopulmonary shunt (bidirectional Glenn shunt is generally performed in many congenital cardiac anomalies where complete two ventricle circulations cannot be easily achieved. The advantages of BDG shunt are achieved by partially separating the pulmonary and systemic venous circuits, and include reduced ventricular preload and long-term preservation of myocardium. The benefits of additional pulsatile pulmonary blood flow include the potential growth of pulmonary arteries, possible improvement in arterial oxygen saturation, and possible prevention of development of pulmonary arteriovenous malformations. However, increase in the systemic venous pressure after BDG with additional pulsatile blood flow is known. We describe the peri-operative implications of severe flow reversal in the superior vena cava after pulsatile BDG shunt construction in a child who presented for surgical interruption of the main pulmonary artery.

Feasibility Study of Ex Ovo Chick Chorioallantoic Artery Model for Investigating Pulsatile Variation of Arterial Geometry.

Directory of Open Access Journals (Sweden)

Kweon-Ho Nam

Full Text Available Despite considerable research efforts on the relationship between arterial geometry and cardiovascular pathology, information is lacking on the pulsatile geometrical variation caused by arterial distensibility and cardiomotility because of the lack of suitable in vivo experimental models and the methodological difficulties in examining the arterial dynamics. We aimed to investigate the feasibility of using a chick embryo system as an experimental model for basic research on the pulsatile variation of arterial geometry. Optical microscope video images of various arterial shapes in chick chorioallantoic circulation were recorded from different locations and different embryo samples. The high optical transparency of the chorioallantoic membrane (CAM allowed clear observation of tiny vessels and their movements. Systolic and diastolic changes in arterial geometry were visualized by detecting the wall boundaries from binary images. Several to hundreds of microns of wall displacement variations were recognized during a pulsatile cycle. The spatial maps of the wall motion harmonics and magnitude ratio of harmonic components were obtained by analyzing the temporal brightness variation at each pixel in sequential grayscale images using spectral analysis techniques. The local variations in the spectral characteristics of the arterial wall motion were reflected well in the analysis results. In addition, mapping the phase angle of the fundamental frequency identified the regional variations in the wall motion directivity and phase shift. Regional variations in wall motion phase angle and fundamental-to-second harmonic ratio were remarkable near the bifurcation area. In summary, wall motion in various arterial geometry including straight, curved and bifurcated shapes was well observed in the CAM artery model, and their local and cyclic variations could be characterized by Fourier and wavelet transforms of the acquired video images. The CAM artery model with

Uric acid association with pulsatile and steady components of central and peripheral blood pressures.

Science.gov (United States)

Lepeytre, Fanny; Lavoie, Pierre-Luc; Troyanov, Stéphan; Madore, François; Agharazii, Mohsen; Goupil, Rémi

2018-03-01

Whether the cardiovascular risk attributed to elevated uric acid levels may be explained by changes in central and peripheral pulsatile and/or steady blood pressure (BP) components remains controversial. In a cross-sectional analysis of normotensive and untreated hypertensive participants of the CARTaGENE populational cohort, we examined the relationship between uric acid, and both pulsatile and steady components of peripheral and central BP, using sex-stratified linear regressions. Of the 20 004 participants, 10 161 individuals without antihypertensive or uric acid-lowering drugs had valid pulse wave analysis and serum uric acid levels. In multivariate analysis, pulsatile components of BP were not associated with uric acid levels, whereas steady components [mean BP (MBP), peripheral and central DBP] were all associated with higher levels of uric acid levels in women and men (all P uric acid levels but not for MBP-adjusted cSBP. Peripheral and cSBP, which are aggregate measures of pulsatile and steady BP, were also associated with uric acid levels in women (β = 0.063 and 0.072, respectively, both P uric acid levels. Serum uric acid levels appear to be associated with both central and peripheral steady but not pulsatile BP, regardless of sex.

Radiometrical, hormonal and biological correlates of skeletal growth in the female rat from birth to senescence.

Science.gov (United States)

del Pozo, Emilio; Janner, Marco; Mackenzie, Andrew R; Arampatzis, Spyridon; Dixon, Arnold K; Perrelet, Romain; Ruch, Walter; Lippuner, Kurt; Zapf, Juergen; Lamberts, Steven W; Mullis, Primus E

2014-01-01

We investigated the skeletal growth profile of female rats from birth to senescence (100weeks) on the basis of sequential radiometrical, hormonal and biochemical parameters. Weaning rats entered the study which was divided into two sections: a) sequential measurements of vertebral and tibial growths and bone mineral density (BMD), estimation of mineral content of the entire skeleton (BMC) and chemical analysis of vertebral Ca; and b) determination of basal and pulsatile growth hormone (rGH), insulin-like growth hormone (IGF-I), estradiol (E2), parathyroid hormone (PTH), osteocalcin (OC) and urinary d-pyridinoline (dp) throughout the experimental period. Vertebral and tibial growths ceased at week 25 whereas BMD and BMC as well as total vertebral Ca exhibited a peak bone mass at week 40. rGH pulsatile profiles were significantly higher in younger animals coinciding with the period of active growth and IGF-I peaked at 7weeks, slowly declining thereafter and stabilizing after week 60. OC and dp closely paralleled IGF-I coinciding with the period of enhanced skeletal growth, remaining thereafter in the low range indicative of reduced bone turnover. E2 increased during reproductive life but the lower values subsequently recorded were still in the physiological range, strongly suggesting a protective role of this steroid on bone remodeling. PTH followed a similar profile to E2, but the significance of this after completion of growth remains unclear. Mechanisms governing skeletal growth in the female rat appear similar to those in humans. Bone progression and attainment of peak bone mass are under simultaneous control of rGH, IGF-I and calciotropic hormones and are modulated by E2. This steroid seems to protect the skeleton from resorption before senescence whereas the role of PTH in this context remains uncertain. Copyright © 2014. Published by Elsevier Ltd.

Pituitary gland development and disease: from stem cell to hormone production.

Science.gov (United States)

Davis, Shannon W; Ellsworth, Buffy S; Peréz Millan, María Inés; Gergics, Peter; Schade, Vanessa; Foyouzi, Nastaran; Brinkmeier, Michelle L; Mortensen, Amanda H; Camper, Sally A

2013-01-01

Many aspects of pituitary development have become better understood in the past two decades. The signaling pathways regulating pituitary growth and shape have emerged, and the balancing interactions between the pathways are now appreciated. Markers for multipotent progenitor cells are being identified, and signature transcription factors have been discovered for most hormone-producing cell types. We now realize that pulsatile hormone secretion involves a 3D integration of cellular networks. About a dozen genes are known to cause pituitary hypoplasia when mutated due to their essential roles in pituitary development. Similarly, a few genes are known that predispose to familial endocrine neoplasia, and several genes mutated in sporadic pituitary adenomas are documented. In the next decade, we anticipate gleaning a deeper appreciation of these processes at the molecular level, insight into the development of the hypophyseal portal blood system, and evolution of better therapeutics for congenital and acquired hormone deficiencies and for common craniopharyngiomas and pituitary adenomas. © 2013 Elsevier Inc. All rights reserved.

Pulsatility role in cylinder flow dynamics at low Reynolds number

KAUST Repository

Qamar, Adnan

2012-01-01

We present dynamics of pulsatile flow past a stationary cylinder characterized by three non-dimensional parameters: the Reynolds number (Re), non-dimensional amplitude (A) of the pulsatile flow velocity, and Keulegan-Carpenter number (KC = Uo/Dωc). This work is motivated by the development of total artificial lungs (TAL) device, which is envisioned to provide ambulatory support to patients. Results are presented for 0.2 ≤ A ≤ 0.6 and 0.57 ≤ KC ≤ 2 at Re = 5 and 10, which correspond to the operating range of TAL. Two distinct fluid regimes are identified. In both regimes, the size of the separated zone is much greater than the uniform flow case, the onset of separation is function of KC, and the separation vortex collapses rapidly during the last fraction of the pulsatile cycle. The vortex size is independent of KC, but with an exponential dependency on A. In regime I, the separation point remains attached to the cylinder surface. In regime II, the separation point migrates upstream of the cylinder. Two distinct vortex collapse mechanisms are observed. For A < 0.4 and all KC and Re values, collapse occurs on the cylinder surface, whereas for A > 0.4 the separation vortex detaches from the cylinder surface and collapses at a certain distance downstream of the cylinder. The average drag coefficient is found to be independent of A and KC, and depends only on Re. However, for A > 0.4, for a fraction of the pulsatile cycle, the instantaneous drag coefficient is negative indicating a thrust production. © 2012 American Institute of Physics.

Measurement of real pulsatile blood flow using X-ray PIV technique with CO2 microbubbles.

Science.gov (United States)

Park, Hanwook; Yeom, Eunseop; Seo, Seung-Jun; Lim, Jae-Hong; Lee, Sang-Joon

2015-03-06

Synchrotron X-ray imaging technique has been used to investigate biofluid flows in a non-destructive manner. This study aims to investigate the feasibility of the X-ray PIV technique with CO2 microbubbles as flow tracer for measurement of pulsatile blood flows under in vivo conditions. The traceability of CO2 microbubbles in a pulsatile flow was demonstrated through in vitro experiment. A rat extracorporeal bypass loop was used by connecting a tube between the abdominal aorta and jugular vein of a rat to obtain hemodynamic information of actual pulsatile blood flows without changing the hemorheological properties. The decrease in image contrast of the surrounding tissue was also investigated for in vivo applications of the proposed technique. This technique could be used to accurately measure whole velocity field information of real pulsatile blood flows and has strong potential for hemodynamic diagnosis of cardiovascular diseases.

Measurement of real pulsatile blood flow using X-ray PIV technique with CO2 microbubbles

Science.gov (United States)

Park, Hanwook; Yeom, Eunseop; Seo, Seung-Jun; Lim, Jae-Hong; Lee, Sang-Joon

2015-01-01

Synchrotron X-ray imaging technique has been used to investigate biofluid flows in a non-destructive manner. This study aims to investigate the feasibility of the X-ray PIV technique with CO2 microbubbles as flow tracer for measurement of pulsatile blood flows under in vivo conditions. The traceability of CO2 microbubbles in a pulsatile flow was demonstrated through in vitro experiment. A rat extracorporeal bypass loop was used by connecting a tube between the abdominal aorta and jugular vein of a rat to obtain hemodynamic information of actual pulsatile blood flows without changing the hemorheological properties. The decrease in image contrast of the surrounding tissue was also investigated for in vivo applications of the proposed technique. This technique could be used to accurately measure whole velocity field information of real pulsatile blood flows and has strong potential for hemodynamic diagnosis of cardiovascular diseases. PMID:25744850

Experimental Investigation of Pulsatile Flow in Circular Tubes

Czech Academy of Sciences Publication Activity Database

Adamec, J.; Nožička, J.; Hanus, D.; Kořenář, Josef

2001-01-01

Roč. 17, č. 5 (2001), s. 1133-1136 ISSN 0748-4658 Institutional research plan: CEZ:AV0Z2060917 Keywords : pulsatile flow * laminar-turbulent transition * reynolds normal stress Subject RIV: BK - Fluid Dynamics Impact factor: 0.418, year: 2001

Evaluation of hepatic venous pulsatility and portal venous velocity with doppler ultrasonography during the puerperium

Energy Technology Data Exchange (ETDEWEB)

Pekindil, Goekhan [Department of Radiology, Trakya University School of Medicine, 22030 Edirne (Turkey); Varol, Fuesun G. [Department of Obstetrics and Gynecology, Trakya University School of Medicine, 22030 Edirne (Turkey); Ali Yuece, M. [Department of Obstetrics and Gynecology, Trakya University School of Medicine, 22030 Edirne (Turkey); Yardim, Turgut [Department of Obstetrics and Gynecology, Trakya University School of Medicine, 22030 Edirne (Turkey)

1999-03-01

Objective: The aim of this study is to evaluate pregnancy-induced changes of hepatic venous pulsatility and portal venous velocity in the puerperium and to determine if these changes disappeared by the end of the puerperium. Methods and material: Healthy normal volunteers (90) were examined on the 2nd and 7th days of puerperium and between the 6th and 8th weeks postpartum. Doppler waveform patterns were obtained in the middle hepatic vein and main portal vein. The hepatic venous pulsatility was named as normal, damped or flat. Results: On the 2nd day postpartum, the hepatic vein pulsatility was shown as normal in 8 (26%), damped in 11 (37%) and flat in 11 (37%) cases. On the 7th day postpartum, 15 (50%) cases had normal, 9 (30%) cases had dampened, and 6 (20%) cases had still flat pattern. The majority of the cases (60%) displayed normal hepatic venous pulsatility in the 6th and 8th weeks of puerperium, whereas 23% had still dampened and 17% had flat patterns. There was a trend toward normal pulsatility with increasing puerperal age. The mean portal venous velocity was still higher than the non-pregnant levels and did not showed significant alterations during puerperium. Conclusion: This study emphasised that, since pregnancy-induced alterations in hepatic venous pulsatility and portal venous velocity had not completely returned to normal in most cases until the end of the puerperium, these physiological changes should be considered whenever hepatic and portal systems are interpreted with Doppler sonography during the puerperal period.

Evaluation of hepatic venous pulsatility and portal venous velocity with doppler ultrasonography during the puerperium

International Nuclear Information System (INIS)

Pekindil, Goekhan; Varol, Fuesun G.; Ali Yuece, M.; Yardim, Turgut

1999-01-01

Objective: The aim of this study is to evaluate pregnancy-induced changes of hepatic venous pulsatility and portal venous velocity in the puerperium and to determine if these changes disappeared by the end of the puerperium. Methods and material: Healthy normal volunteers (90) were examined on the 2nd and 7th days of puerperium and between the 6th and 8th weeks postpartum. Doppler waveform patterns were obtained in the middle hepatic vein and main portal vein. The hepatic venous pulsatility was named as normal, damped or flat. Results: On the 2nd day postpartum, the hepatic vein pulsatility was shown as normal in 8 (26%), damped in 11 (37%) and flat in 11 (37%) cases. On the 7th day postpartum, 15 (50%) cases had normal, 9 (30%) cases had dampened, and 6 (20%) cases had still flat pattern. The majority of the cases (60%) displayed normal hepatic venous pulsatility in the 6th and 8th weeks of puerperium, whereas 23% had still dampened and 17% had flat patterns. There was a trend toward normal pulsatility with increasing puerperal age. The mean portal venous velocity was still higher than the non-pregnant levels and did not showed significant alterations during puerperium. Conclusion: This study emphasised that, since pregnancy-induced alterations in hepatic venous pulsatility and portal venous velocity had not completely returned to normal in most cases until the end of the puerperium, these physiological changes should be considered whenever hepatic and portal systems are interpreted with Doppler sonography during the puerperal period

Generation of tunable and pulsatile concentration gradients via microfluidic network

KAUST Repository

Zhou, Bingpu

2014-06-04

We demonstrate a compact Polydimethylsiloxane microfluidic chip which can quickly generate ten different chemical concentrations simultaneously. The concentration magnitude of each branch can be flexibly regulated based on the flow rate ratios of the two injecting streams. The temporal/pulsatile concentration gradients are achieved by integrating on-chip pneumatic actuated valves controlled by the external signals. The temporal concentration gradients can also be tuned precisely by varying applied frequency and duty cycle of the trigger signal. It is believed that such microdevice will be potentially used for some application areas of producing stable chemical gradients as well as allowing fast, pulsatile gradient transformation in seconds.

The use of gonadotrophin-releasing hormone antagonists in polycystic ovarian disease.

Science.gov (United States)

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

An in vitro experimental study of flow past aortic valve under varied pulsatile conditions

Science.gov (United States)

Zhang, Ruihang; Zhang, Yan

2017-11-01

Flow past aortic valve represents a complex fluid-structure interaction phenomenon that involves pulsatile, vortical, and turbulent conditions. The flow characteristics immediately downstream of the valve, such as the variation of pulsatile flow velocity, formation of vortices, distribution of shear stresses, are of particular interest to further elucidate the role of hemodynamics in various aortic diseases. However, the fluid dynamics of a realistic aortic valve is not fully understood. Particularly, it is unclear how the flow fields downstream of the aortic valve would change under varied pulsatile inlet boundary conditions. In this study, an in vitro experiment has been conducted to investigate the flow fields downstream of a silicone aortic valve model within a cardiovascular flow simulator. Phased-locked Particle Image Velocimetry measurements were performed to map the velocity fields and Reynolds normal and shear stresses at different phases in a cardiac cycle. Temporal variations of pressure across the valve model were measured using high frequency transducers. Results have been compared for different pulsatile inlet conditions, including varied frequencies (heart rates), magnitudes (stroke volumes), and cardiac contractile functions (shapes of waveforms).

Closing in on the Mechanisms of Pulsatile Insulin Secretion.

Science.gov (United States)

Bertram, Richard; Satin, Leslie S; Sherman, Arthur S

2018-03-01

Insulin secretion from pancreatic islet β-cells occurs in a pulsatile fashion, with a typical period of ∼5 min. The basis of this pulsatility in mouse islets has been investigated for more than four decades, and the various theories have been described as either qualitative or mathematical models. In many cases the models differ in their mechanisms for rhythmogenesis, as well as other less important details. In this Perspective, we describe two main classes of models: those in which oscillations in the intracellular Ca 2+ concentration drive oscillations in metabolism, and those in which intrinsic metabolic oscillations drive oscillations in Ca 2+ concentration and electrical activity. We then discuss nine canonical experimental findings that provide key insights into the mechanism of islet oscillations and list the models that can account for each finding. Finally, we describe a new model that integrates features from multiple earlier models and is thus called the Integrated Oscillator Model. In this model, intracellular Ca 2+ acts on the glycolytic pathway in the generation of oscillations, and it is thus a hybrid of the two main classes of models. It alone among models proposed to date can explain all nine key experimental findings, and it serves as a good starting point for future studies of pulsatile insulin secretion from human islets. © 2018 by the American Diabetes Association.

Enhancement of Arterial Pressure Pulsatility by Controlling Continuous-Flow Left Ventricular Assist Device Flow Rate in Mock Circulatory System.

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Bozkurt, Selim; van de Vosse, Frans N; Rutten, Marcel C M

Continuous-flow left ventricular assist devices (CF-LVADs) generally operate at a constant speed, which reduces pulsatility in the arteries and may lead to complications such as functional changes in the vascular system, gastrointestinal bleeding, or both. The purpose of this study is to increase the arterial pulse pressure and pulsatility by controlling the CF-LVAD flow rate. A MicroMed DeBakey pump was used as the CF-LVAD. A model simulating the flow rate through the aortic valve was used as a reference model to drive the pump. A mock circulation containing two synchronized servomotor-operated piston pumps acting as left and right ventricles was used as a circulatory system. Proportional-integral control was used as the control method. First, the CF-LVAD was operated at a constant speed. With pulsatile-speed CF-LVAD assistance, the pump was driven such that the same mean pump output was generated. Continuous and pulsatile-speed CF-LVAD assistance provided the same mean arterial pressure and flow rate, while the index of pulsatility increased significantly for both arterial pressure and pump flow rate signals under pulsatile speed pump support. This study shows the possibility of improving the pulsatility of CF-LVAD support by regulating pump speed over a cardiac cycle without reducing the overall level of support.

Positron emission particle tracking in pulsatile flow

Energy Technology Data Exchange (ETDEWEB)

Patel, Nitant; Ruggles, Arthur [University of Tennessee-Knoxville, Department of Nuclear Engineering, Knoxville, TN (United States); Wiggins, Cody [University of Tennessee-Knoxville, Department of Physics and Astronomy, Knoxville, TN (United States)

2017-05-15

Positron emission particle tracking (PEPT) is increasingly used to understand the flow characteristics in complex systems. This research utilizes PEPT to measure pulsatile flow of frequency 2.1 Hz in an elastic Masterkleer PVC tube of 19 mm inner diameter and 3.2 mm wall thickness. Anion exchange resin beads are labeled with {sup 18}F and delivered to a pump driven flow loop with motorized ball valve used to develop the pulsatile flow. Data are collected in the tube with circular cross section, and measurements are also collected with a section of the tube pinched. Nominal flow velocities are near 1 m/s and Reynolds numbers near 20,000. Many thousand PEPT particle traces are collected and synchronized with the flow pulsation. These Lagrangian data are presented as a series of 20 still frames depicting the 3-D velocity field present during each phase of the flow pulsation. Pressure data are also collected to resolve the pressure wave front moving through the open elastic tube at velocity 15.2 m/s. (orig.)

Pulsatile flow in ventricular catheters for hydrocephalus

Science.gov (United States)

Giménez, Á.; Galarza, M.; Thomale, U.; Schuhmann, M. U.; Valero, J.; Amigó, J. M.

2017-05-01

The obstruction of ventricular catheters (VCs) is a major problem in the standard treatment of hydrocephalus, the flow pattern of the cerebrospinal fluid (CSF) being one important factor thereof. As a first approach to this problem, some of the authors studied previously the CSF flow through VCs under time-independent boundary conditions by means of computational fluid dynamics in three-dimensional models. This allowed us to derive a few basic principles which led to designs with improved flow patterns regarding the obstruction problem. However, the flow of the CSF has actually a pulsatile nature because of the heart beating and blood flow. To address this fact, here we extend our previous computational study to models with oscillatory boundary conditions. The new results will be compared with the results for constant flows and discussed. It turns out that the corrections due to the pulsatility of the CSF are quantitatively small, which reinforces our previous findings and conclusions. This article is part of the themed issue `Mathematical methods in medicine: neuroscience, cardiology and pathology'.

Is the use of low-pressure pulsatile lavage for pressure ulcer management associated with environmental contamination with Acinetobacter baumannii?

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Ho, Chester H; Johnson, Tova; Miklacic, Joan; Donskey, Curtis J

2009-10-01

Ho CH, Johnson T, Miklacic J, Donskey CJ. Is the use of low-pressure pulsatile lavage for pressure ulcer management associated with environmental contamination with Acinetobacter baumannii? To determine the extent of environmental contamination associated with low-pressure pulsatile lavage of stage III or IV pressure ulcers in patients with spinal cord injury (SCI) when routine infection control precautions are used for wounds colonized or infected with Acinetobacter baumannii. Prospective investigation in which pressure ulcer cultures and environmental cultures were obtained before and after low-pressure pulsatile lavage treatment, and before and after regular dressing changes. Environmental cultures included the patient's bedrail and settle plates placed 0.6, 1.5, and 2.4m from the wound to assess airborne spread of A. baumannii. SCI inpatient unit in a Department of Veterans Affairs Medical Center. Inpatients (N=15) with SCI receiving daily low-pressure pulsatile lavage treatment for stage III or IV pressure ulcers with standard dressing change, as well as regular dressing changes without low-pressure pulsatile lavage at other times of the day. Standard, regular dressing changes and dressing changes with low-pressure pulsatile lavage. Comparison of frequency of environmental contamination with A. baumannii associated with low-pressure pulsatile lavage versus regular dressing changes. Of the 15 SCI inpatients meeting inclusion criteria, 9 (60%) grew A. baumannii from their wounds. Of the 9 patients with wound cultures positive for A. baumannii, only 1 (11%) had environmental contamination with this organism after performance of low-pressure pulsatile lavage, and the same patient had environmental contamination after a standard dressing change. The antibiotic susceptibility patterns of the wound and environmental A. baumannii isolates were identical. Low-pressure pulsatile lavage using the infection control methods described is not associated with an increased

Sigmoid Sinus Diverticulum, Dehiscence, and Venous Sinus Stenosis: Potential Causes of Pulsatile Tinnitus in Patients with Idiopathic Intracranial Hypertension?

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Lansley, J A; Tucker, W; Eriksen, M R; Riordan-Eva, P; Connor, S E J

2017-09-01

Pulsatile tinnitus is experienced by most patients with idiopathic intracranial hypertension. The pathophysiology remains uncertain; however, transverse sinus stenosis and sigmoid sinus diverticulum/dehiscence have been proposed as potential etiologies. We aimed to determine whether the prevalence of transverse sinus stenosis and sigmoid sinus diverticulum/dehiscence was increased in patients with idiopathic intracranial hypertension and pulsatile tinnitus relative to those without pulsatile tinnitus and a control group. CT vascular studies of patients with idiopathic intracranial hypertension with pulsatile tinnitus ( n = 42), without pulsatile tinnitus ( n = 37), and controls ( n = 75) were independently reviewed for the presence of severe transverse sinus stenosis and sigmoid sinus diverticulum/dehiscence according to published criteria. The prevalence of transverse sinus stenosis and sigmoid sinus diverticulum/dehiscence in patients with idiopathic intracranial hypertension with pulsatile tinnitus was compared with that in the nonpulsatile tinnitus idiopathic intracranial hypertension group and the control group. Further comparisons included differing degrees of transverse sinus stenosis (50% and 75%), laterality of transverse sinus stenosis/sigmoid sinus diverticulum/dehiscence, and ipsilateral transverse sinus stenosis combined with sigmoid sinus diverticulum/dehiscence. Severe bilateral transverse sinus stenoses were more frequent in patients with idiopathic intracranial hypertension than in controls ( P tinnitus within the idiopathic intracranial hypertension group. Sigmoid sinus dehiscence (right- or left-sided) was also more common in patients with idiopathic intracranial hypertension compared with controls ( P = .01), but there was no significant association with pulsatile tinnitus within the idiopathic intracranial hypertension group. While our data corroborate previous studies demonstrating increased prevalence of sigmoid sinus diverticulum

The Characteristics of Turbulence in Curved Pipes under Highly Pulsatile Flow Conditions

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Kalpakli, A.; Örlü, R.; Tillmark, N.; Alfredsson, P. Henrik

High speed stereoscopic particle image velocimetry has been employed to provide unique data from a steady and highly pulsatile turbulent flow at the exit of a 90 degree pipe bend. Both the unsteady behaviour of the Dean cells under steady conditions, the so called "swirl switching" phenomenon, as well as the secondary flow under pulsations have been reconstructed through proper orthogonal decomposition. The present data set constitutes - to the authors' knowledge - the first detailed investigation of a turbulent, pulsatile flow through a pipe bend.

Pulsatile thyrotropin secretion in patients with Cushing's syndrome

NARCIS (Netherlands)

Adriaanse, R.; Brabant, G.; Endert, E.; Wiersinga, W. M.

1994-01-01

Pulsatile and circadian thyrotropin (TSH) secretion were studied in 16 healthy controls and in three patients with Cushing's syndrome who were studied twice (before and after treatment). Blood was sampled every 10 minutes over 24 hours for TSH (immunoradiometric assay [IRMA]). Mean 24-hour TSH in

Ultradian rhythms in pituitary and adrenal hormones: their relations to sleep.

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Gronfier, C; Brandenberger, G

1998-02-01

Sleep and circadian rhythmicity both influence the 24-h profiles of the main pituitary and adrenal hormones. From studies using experimental strategies including complete and partial sleep deprivation, acute and chronic shifts in the sleep period, or complete sleep-wake reversal as occurs with transmeridian travel or shift-work, it appears that prolactin (PRL) and growth hormone (GH) profiles are mainly sleep related, while cortisol profile is mainly controlled by the circadian clock with a weak influence of sleep processes. Thyrotropin (TSH) profile is under the dual influence of sleep and circadian rhythmicity. Recent studies, in which we used spectral analysis of sleep electroencephalogram (EEG) rather than visual scoring of sleep stages, have evaluated the temporal associations between pulsatile hormonal release and the variations in sleep EEG activity. Pulses in PRL and in GH are positively linked to increases in delta wave activity, whereas TSH and cortisol pulses are related to decreases in delta wave activity. It is yet not clear whether sleep influences endocrine secretion, or conversely, whether hormone secretion affects sleep structure. These well-defined relationships raise the question of their physiological significance and of their clinical implications.

Pulsatile Lavage of Musculoskeletal Wounds Causes Muscle Necrosis and Dystrophic Calcification in a Rat Model.

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Chiaramonti, Alexander M; Robertson, Astor D; Nguyen, Thao P; Jaffe, David E; Hanna, E Lex; Holmes, Robert; Barfield, William R; Fourney, William L; Stains, Joseph P; Pellegrini, Vincent D

2017-11-01

Adequate irrigation of open musculoskeletal injuries is considered the standard of care to decrease bacterial load and other contaminants. While the benefit of debris removal compared with the risk of further seeding by high-pressure lavage has been studied, the effects of irrigation on muscle have been infrequently reported. Our aim in the present study was to assess relative damage to muscle by pulsatile lavage compared with bulb-syringe irrigation. In an animal model of heterotopic ossification, 24 Sprague-Dawley rats underwent hindlimb blast amputation via detonation of a submerged explosive, with subsequent through-the-knee surgical amputation proximal to the zone of injury. All wounds were irrigated and underwent primary closure. In 12 of the animals, pulsatile lavage (20 psi [138 kPa]) was used as the irrigation method, and in the other 12 animals, bulb-syringe irrigation was performed. A third group of 6 rats did not undergo the blast procedure but instead underwent surgical incision into the left thigh muscle followed by pulsatile lavage. Serial radiographs of the animals were made to monitor the formation of soft-tissue radiopaque lesions until euthanasia at 6 months. Image-guided muscle biopsies were performed at 8 weeks and 6 months (at euthanasia) on representative animals from each group. Histological analysis was performed with hematoxylin and eosin, alizarin red, and von Kossa staining on interval biopsy and postmortem specimens. All animals managed with pulsatile lavage, with or without blast injury, developed soft-tissue radiopaque lesions, whereas no animal that had bulb-syringe irrigation developed these lesions (p = 0.001). Five of the 12 animals that underwent blast amputation with pulsatile lavage experienced wound complications, whereas no animal in the other 2 groups experienced wound complications (p = 0.014). Radiopaque lesions appeared approximately 10 days postoperatively, increased in density until approximately 16 weeks, then

Continuous 24-hour intravenous infusion of recombinant human growth hormone (GH)-releasing hormone-(1-44)-amide augments pulsatile, entropic, and daily rhythmic GH secretion in postmenopausal women equally in the estrogen-withdrawn and estrogen-supplemented states.

Science.gov (United States)

Evans, W S; Anderson, S M; Hull, L T; Azimi, P P; Bowers, C Y; Veldhuis, J D

2001-02-01

How estrogen amplifies GH secretion in the human is not known. The present study tests the clinical hypothesis that estradiol modulates the stimulatory actions of a primary GH feedforward signal, GHRH. To this end, we investigated the ability of short-term (7- to 12-day) supplementation with oral estradiol vs. placebo to modulate basal, pulsatile, entropic, and 24-h rhythmic GH secretion driven by a continuous iv infusion of recombinant human GHRH-(1--44)-amide vs. saline in nine healthy postmenopausal women. Volunteers underwent concurrent blood sampling every 10 min for 24 h on four occasions in a prospectively randomized, single blind, within-subject cross-over design (placebo/saline, placebo/GHRH, estradiol/saline, estradiol/GHRH). Intensively sampled serum GH concentrations were quantitated by ultrasensitive chemiluminescence assay. Basal, pulsatile, entropic (feedback-sensitive), and 24-h rhythmic modes of GH secretion were appraised by deconvolution analysis, the approximate entropy (ApEn) statistic, and cosine regression, respectively. ANOVA revealed that continuous iv infusion of GHRH in the estrogen-withdrawn (control) milieu 1) amplified individual basal (P = 0.00011) and pulsatile (P < 10(-13)) GH secretion rates by 12- and 11-fold, respectively; 2) augmented GH secretory burst mass and amplitude each by 10-fold (P < 10(-11)), without altering GH secretory burst frequency, duration, or half-life; 3) increased the disorderliness (ApEn) of GH release patterns (P = 0.0000002); 4) elevated the mesor (cosine mean) and amplitude of the 24-h rhythm in serum GH concentrations by nearly 30-fold (both P < 10(-12)); 5) induced a phase advance in the clocktime of the GH zenith (P = 0.021); and 6) evoked a new 24-h rhythm in GH secretory burst mass with a maximum at 0018 h GH (P < 10(-3)), while damping the mesor of the 24-h rhythm in GH interpulse intervals (P < 0.025). Estradiol supplementation alone 1) increased the 24-h mean and integrated serum GH concentration

Pivagabine decreases stress-related hormone secretion in women with hypothalamic amenorrhea.

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Genazzani, A D; Stomati, M; Bersi, C; Luisi, S; Fedalti, M; Santuz, M; Esposito, G; Petraglia, F; Genazzani, A R

2000-09-01

Stress-induced neuroendocrine activities influence the regulation of endocrine glands and axes. Weight loss-related hypothalamic amenorrhea is a typical stress-induced physiopathological condition. It is characterized by increased adrenal cortex activation and by reduced GH, LH, FSH and gonadal steroid hormone levels. The aim of the present study was to investigate the effects of pivagabine, a neurotropic drug (1800 mg/day for 7 days) or placebo administration on ACTH, cortisol, GH, LH, FSH and PRL plasma levels in patients with hypothalamic amenorrhea related to weight loss. Hormonal parameters and the pulsatile release of cortisol (6-hour pulsatility, sampling every 10 minutes) were evaluated before and after 7 days of treatment. Pivagabine administration significantly reduced mean plasma ACTH (from 21.7+/-1.7 to 15.4+/-1.2 pg/ml, p<0.05) and cortisol levels (from 12.2+/-0.7 to 9.7+/-0.7 ng/ml, p<0.05) and increased GH levels (from 1.4+/-0.5 to 3.0+/-0.9 ng/ml, p<0.05). A significant reduction of cortisol pulse amplitude was observed (p<0.01) while no change in pulse frequency occurred. No changes were observed in placebo-treated subjects. LH, FSH and PRL levels were not modified by placebo or pivagabine administration. In conclusion, in patients with hypothalamic amenorrhea related to weight loss pivagabine induced a significant decrease of cortisol secretion and an increase of GH release by pivagabine administration, suggesting that this drug exerts a specific neuroendocrine modulatory role.

Augmentative effect of pulsatility on the wall shear stress in tube flow.

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Nakata, M; Tatsumi, E; Tsukiya, T; Taenaka, Y; Nishimura, T; Nishinaka, T; Takano, H; Masuzawa, T; Ohba, K

1999-08-01

Wall shear stress (WSS) has been considered to play an important role in the physiological and metabolic functions of the vascular endothelial cells. We investigated the effects of the pulse rate and the maximum flow rate on the WSS to clarify the influence of pulsatility. Water was perfused in a 1/2 inch transparent straight cylinder with a nonpulsatile centrifugal pump and a pulsatile pneumatic ventricular assist device (VAD). In nonpulsatile flow (NF), the flow rate was changed 1 to 6 L/min by 1 L/min increments to obtain standard values of WSS at each flow rate. In pulsatile flow (PF), the pulse rate was controlled at 40, 60, and 80 bpm, and the maximum flow rate was varied from 3.3 to 12.0 L/min while the mean flow rate was kept at 3 L/min. The WSS was estimated from the velocity profile at measuring points using the laser illuminated fluorescence method. In NF, the WSS was 12.0 dyne/cm2 at 3 L/min and 33.0 dyne/cm2 at 6 L/min. In PF, the pulse rate change with the same mean, and the maximum flow rate did not affect WSS. On the other hand, the increase in the maximum flow rate at the constant mean flow rate of 3 L/min augmented the mean WSS from 13.1 to 32.9 dyne/cm2. We concluded that the maximum flow rate exerted a substantial augmentative effect on WSS, and the maximum flow rate was a dominant factor of pulsatility in this effect.

On the pulsatile nature of intracranial and spinal CSF-circulation demonstrated by MR imaging

International Nuclear Information System (INIS)

Greitz, D.; Franck, A.; Nordell, B.

1993-01-01

Cerebrospinal fluid (CSF) flow was studied in 24 healthy volunteers using gated MR phase imaging. The subarachnoid space (SAS) was divided into 5 compartments depending on the magnitude of the pulsatile CSF flows: a high velocity compartment in the area of the brain stem and spinal cord, 2 slow ones at the upper and lower extremes of the SAS, and finally 2 intermediate velocity compartments in between. The main pulsatile spinal flow channel had a meandering pattern. The extraventricular CSF-circulation can be explained by pulsatile CSF flow without the necessity of assuming existence of a net flow. A successive time offset during the cardiac cycle has been found in the fronto-occipital direction of the interplay between the arterial expansion, brain expansion, volume changes of the CSF spaces and of the veins. It is proposed to name this time offset the intracranial ''volume wave'' (VoW). (orig.)

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.

Does Flexible Arterial Tubing Retain More Hemodynamic Energy During Pediatric Pulsatile Extracorporeal Life Support?

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Wang, Shigang; Kunselman, Allen R; Ündar, Akif

2017-01-01

The objective of this study was to evaluate the hemodynamic performance and energy transmission of flexible arterial tubing as the arterial line in a simulated pediatric pulsatile extracorporeal life support (ECLS) system. The ECLS circuit consisted of a Medos Deltastream DP3 diagonal pump head, Medos Hilite 2400 LT oxygenator, Biomedicus arterial/venous cannula (10 Fr/14 Fr), 3 feet of polyvinyl chloride (PVC) arterial tubing or latex rubber arterial tubing, primed with lactated Ringer's solution and packed red blood cells (hematocrit 40%). Trials were conducted at flow rates of 300 to 1200 mL/min (300 mL/min increments) under nonpulsatile and pulsatile modes at 36°C using either PVC arterial tubing (PVC group) or latex rubber tubing (Latex group). Real-time pressure and flow data were recorded using a custom-based data acquisition system. Mean pressures and energy equivalent pressures (EEP) were the same under nonpulsatile mode between the two groups. Under pulsatile mode, EEPs were significantly great than mean pressure, especially in the Latex group (P tubing retained more hemodynamic energy passing through it under pulsatile mode while mean pressures and pressure drops across the ECLS circuit were similar between PVC and latex rubber arterial tubing. Further studies are warranted to verify our findings. © 2016 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Tissue Doppler Imaging in the evaluation of abdominal aortic pulsatility: a useful tool for the neonatologist.

Science.gov (United States)

Valerio, Enrico; Grison, Alessandra; Capretta, Anna; Golin, Rosanna; Ferrarese, Paola; Bellettato, Massimo

2017-03-01

Sonographic cardiac evaluation of newborns with suspected aortic coarctation (AoC) should tend to demonstrate a good phasic and pulsatile flow and the absence of pressure gradient along a normally conformed aortic arch from the modified left parasternal and suprasternal echocardiographic views; these findings, however, may not necessarily rule out a more distal coarctation in the descending aorta. For this reason, the sonographic exam of newborns with suspected AoC should always include a Doppler evaluation of abdominal aortic blood flow from the subcostal view. Occasionally, however, a clearly pulsatile Doppler flow trace in abdominal aorta may be difficult to obtain due to the bad insonation angle existing between the probe and the vessel. In such suboptimal ultrasonic alignment situation, the use of Tissue Doppler Imaging instead of classic Doppler flow imaging may reveal a preserved aortic pulsatility by sampling the aortic wall motion induced by normal flow. We propose to take advantage of the TDI pattern as a surrogate of a normal pulsatile Doppler flow trace in abdominal aorta when the latter is difficult to obtain due to malalignment with the insonated vessel.

Precise position control of a helical magnetic robot in pulsatile flow using the rotating frequency of the external magnetic field

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Jongyul Kim

2017-05-01

Full Text Available We propose a position control method for a helical magnetic robot (HMR that uses the rotating frequency of the external rotating magnetic field (ERMF to minimize the position fluctuation of the HMR caused by pulsatile flow in human blood vessels. We prototyped the HMR and conducted several experiments in pseudo blood vessel environments with a peristaltic pump. We experimentally obtained the relation between the flow rate and the rotating frequency of the ERMF required to make the HMR stationary in a given pulsatile flow. Then we approximated the pulsatile flow by Fourier series and applied the required ERMF rotating frequency to the HMR in real time. Our proposed position control method drastically reduced the position fluctuation of the HMR under pulsatile flow.

Stability of Carotid Artery Under Steady-State and Pulsatile Blood Flow: A Fluid–Structure Interaction Study

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Saeid Khalafvand, Seyed; Han, Hai-Chao

2015-01-01

It has been shown that arteries may buckle into tortuous shapes under lumen pressure, which in turn could alter blood flow. However, the mechanisms of artery instability under pulsatile flow have not been fully understood. The objective of this study was to simulate the buckling and post-buckling behaviors of the carotid artery under pulsatile flow using a fully coupled fluid–structure interaction (FSI) method. The artery wall was modeled as a nonlinear material with a two-fiber strain-energy function. FSI simulations were performed under steady-state flow and pulsatile flow conditions with a prescribed flow velocity profile at the inlet and different pressures at the outlet to determine the critical buckling pressure. Simulations were performed for normal (160 ml/min) and high (350 ml/min) flow rates and normal (1.5) and reduced (1.3) axial stretch ratios to determine the effects of flow rate and axial tension on stability. The results showed that an artery buckled when the lumen pressure exceeded a critical value. The critical mean buckling pressure at pulsatile flow was 17–23% smaller than at steady-state flow. For both steady-state and pulsatile flow, the high flow rate had very little effect (<5%) on the critical buckling pressure. The fluid and wall stresses were drastically altered at the location with maximum deflection. The maximum lumen shear stress occurred at the inner side of the bend and maximum tensile wall stresses occurred at the outer side. These findings improve our understanding of artery instability in vivo. PMID:25761257

Stability of carotid artery under steady-state and pulsatile blood flow: a fluid-structure interaction study.

Science.gov (United States)

Saeid Khalafvand, Seyed; Han, Hai-Chao

2015-06-01

It has been shown that arteries may buckle into tortuous shapes under lumen pressure, which in turn could alter blood flow. However, the mechanisms of artery instability under pulsatile flow have not been fully understood. The objective of this study was to simulate the buckling and post-buckling behaviors of the carotid artery under pulsatile flow using a fully coupled fluid-structure interaction (FSI) method. The artery wall was modeled as a nonlinear material with a two-fiber strain-energy function. FSI simulations were performed under steady-state flow and pulsatile flow conditions with a prescribed flow velocity profile at the inlet and different pressures at the outlet to determine the critical buckling pressure. Simulations were performed for normal (160 ml/min) and high (350 ml/min) flow rates and normal (1.5) and reduced (1.3) axial stretch ratios to determine the effects of flow rate and axial tension on stability. The results showed that an artery buckled when the lumen pressure exceeded a critical value. The critical mean buckling pressure at pulsatile flow was 17-23% smaller than at steady-state flow. For both steady-state and pulsatile flow, the high flow rate had very little effect (<5%) on the critical buckling pressure. The fluid and wall stresses were drastically altered at the location with maximum deflection. The maximum lumen shear stress occurred at the inner side of the bend and maximum tensile wall stresses occurred at the outer side. These findings improve our understanding of artery instability in vivo.

The detection of ovulation with a two-hour radioimmunoassay for human plasma luteinizing hormone using the Centria Analyzer

International Nuclear Information System (INIS)

Schwarz, S.

1980-01-01

We describe a rapid (2-h) radioimmunoassay for human plasma luteinizing hormone which utilizes the reagents from a commercially available kit. Standardization of the assay was achieved using plasma standards instead of a buffer system and the Centria radioimmunoassay centrifugal analyzer which allowed simultaneous initiation and termination of reactions in all assay tubes. The specificity, precision, and accuracy of the assay were equal to or better than the conventional 24-h assay. Since this assay is designed to detect the mid-cycle surge of luteinizing hormone, its decreased sensitivity was small price to pay for the speed with which a result could be obtained. (orig.) [de

Association between the extent of sigmoid sinus dehiscence and an occurrence of pulsatile tinnitus: a retrospective imaging study

International Nuclear Information System (INIS)

Dong, C.; Zhao, P.; Liu, Z.; Xu, W.; Lv, H.; Pang, S.; Wang, Z.

2016-01-01

Aim: To assess the extent of sigmoid sinus dehiscence (SSD) on high-resolution computed tomography venography (HRCTV) or high-resolution computed tomography (HRCT) images in pulsatile tinnitus (PT) and non-PT groups to determine whether there is an association between the extent of SSD and occurrence of PT. Materials and methods: Twenty-eight SSD patients with ipsilateral PT and 28 age- and gender-matched SSD patients without PT who underwent HRCTV or HRCT were enrolled in this study and categorised into two groups: “PT group” and “non-PT group”. The extent of SSD in each group was calculated and compared. Results: The largest transverse diameter and largest vertical diameter of SSD in the PT group were 6.21±1.7 and 6.15±2.19 mm, respectively. The largest transverse diameter and largest vertical diameter of SSD in the non-PT group were 3.06±1.38 and 2.51±1.03 mm, respectively. The extent of SSD was statistically different between the two groups (p<0.001; p<0.001). Conclusions: As a cause of PT, SSD can also occur in individuals without PT symptoms. Preliminary findings suggest that there may be a potential correlation between the extent of SSD and an occurrence of PT. - Highlights: • We compared the extent of sigmoid sinus dehiscence in pulsatile tinnitus and non-pulsatile tinnitus groups. • The sigmoid sinus dehiscence in the pulsatile tinnitus patients was larger than those in non-pulsatile tinnitus patients. • There may be a potential correlation between the extent of sigmoid sinus dehiscence and an occurrence of pulsatile tinnitus.

Obesity, serum steroid levels, and pulsatile gonadotropin secretion in polycystic ovarian disease.

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Laatikainen, T; Tulenheimo, A; Andersson, B; Kärkkäinen, J

1983-04-01

Serum binding capacity of sex-hormone binding globulin (SHBG-BC), steroid concentrations, and secretion patterns of LH and FSH were compared between groups of seven nonobese and seven obese patients with polycystic ovarian disease (PCOD). Obese patients with PCOD differed from those with normal weight in having very low SHBG-BC and elevated serum levels of free and albumin bound testosterone. Compared to healthy women in the follicular phase, both nonobese and obese patients with PCOD showed equally elevated serum levels of androstenedione, estrone, and albumin-bound and free estradiol. Pattern of gonadotropin secretion was studied from blood samples taken at 15 min intervals for 6 h. In 6 patients of both groups low pulses of FSH were found coincidently with pulses of LH. Serum level of LH showed a clear pulsatile pattern in all patients with PCOD, varying from 4.5 to 7.5 pulses per 6 h. The mean pulse rate in the groups of nonobese and obese patients with PCOD was similar, 5.9 pulses per 6 h. In the obese patients the mean LH levels were, however, less elevated and the pulse amplitudes were smaller than those in the nonobese patients. We suggest that this difference is due to high levels of biologically active testosterone in obese patients with PCOD.

Nonlinear dynamics of shells conveying pulsatile flow with pulse-wave propagation. Theory and numerical results for a single harmonic pulsation

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Tubaldi, Eleonora; Amabili, Marco; Païdoussis, Michael P.

2017-05-01

In deformable shells conveying pulsatile flow, oscillatory pressure changes cause local movements of the fluid and deformation of the shell wall, which propagate downstream in the form of a wave. In biomechanics, it is the propagation of the pulse that determines the pressure gradient during the flow at every location of the arterial tree. In this study, a woven Dacron aortic prosthesis is modelled as an orthotropic circular cylindrical shell described by means of the Novozhilov nonlinear shell theory. Flexible boundary conditions are considered to simulate connection with the remaining tissue. Nonlinear vibrations of the shell conveying pulsatile flow and subjected to pulsatile pressure are investigated taking into account the effects of the pulse-wave propagation. For the first time in literature, coupled fluid-structure Lagrange equations of motion for a non-material volume with wave propagation in case of pulsatile flow are developed. The fluid is modeled as a Newtonian inviscid pulsatile flow and it is formulated using a hybrid model based on the linear potential flow theory and considering the unsteady viscous effects obtained from the unsteady time-averaged Navier-Stokes equations. Contributions of pressure and velocity propagation are also considered in the pressure drop along the shell and in the pulsatile frictional traction on the internal wall in the axial direction. A numerical bifurcation analysis employs a refined reduced order model to investigate the dynamic behavior of a pressurized Dacron aortic graft conveying blood flow. A pulsatile time-dependent blood flow model is considered by applying the first harmonic of the physiological waveforms of velocity and pressure during the heart beating period. Geometrically nonlinear vibration response to pulsatile flow and transmural pulsatile pressure, considering the propagation of pressure and velocity changes inside the shell, is here presented via frequency-response curves, time histories, bifurcation

Estimating right ventricular stroke work and the pulsatile work fraction in pulmonary hypertension.

Science.gov (United States)

Chemla, Denis; Castelain, Vincent; Zhu, Kaixian; Papelier, Yves; Creuzé, Nicolas; Hoette, Susana; Parent, Florence; Simonneau, Gérald; Humbert, Marc; Herve, Philippe

2013-05-01

The mean pulmonary artery pressure (mPAP) replaces mean systolic ejection pressure (msePAP) in the classic formula of right ventricular stroke work (RVSW) = (mPAP - RAP) × stroke volume, where RAP is mean right atrial pressure. Only the steady work is thus taken into account, not the pulsatile work, whereas pulmonary circulation is highly pulsatile. Our retrospective, high-fidelity pressure study tested the hypothesis that msePAP was proportional to mPAP, and looked at the implications for RVSW. Eleven patients with severe, precapillary pulmonary hypertension (PH) (six patients with idiopathic pulmonary arterial hypertension and five with chronic thromboembolic PH; mPAP = 57 ± 10 mm Hg) were studied at rest and during mild to moderate exercise. Eight non-PH control subjects were also studied at rest (mPAP = 16 ± 2 mm Hg). The msePAP was averaged from end diastole to dicrotic notch. In the full data set (53 pressure-flow points), mPAP ranged from 14 to 99.5 mm Hg, cardiac output from 2.38 to 11.1 L/min, and heart rate from 53 to 163 beats/min. There was a linear relationship between msePAP and mPAP (r² = 0.99). The msePAP matched 1.25 mPAP (bias, -0.5 ± 2.6 mm Hg). Results were similar in the resting non-PH group and in resting and the exercising PH group. This implies that the classic formula markedly underestimates RVSW and that the pulsatile work may be a variable 20% to 55% fraction of RVSW, depending on RAP and mPAP. At rest, RVSW in patients with PH was twice as high as that of the non-PH group (P work fraction was similar between the two groups (26 ± 4% vs 24 ± 1%) because of the counterbalancing effects of high RAP (11 ± 5 mm Hg vs 4 ± 2 mm Hg), which increases the fraction, and high mPAP, which decreases the fraction. Our study favored the use of an improved formula that takes into account the variable pulsatile work fraction: RVSW = (1.25 mPAP - RAP) × stroke volume. Increased RAP and increased mPAP have opposite effects on the pulsatile work

Pulsatile operation of a continuous-flow right ventricular assist device (RVAD) to improve vascular pulsatility.

Science.gov (United States)

Ng, Boon C; Kleinheyer, Matthias; Smith, Peter A; Timms, Daniel; Cohn, William E; Lim, Einly

2018-01-01

Despite the widespread acceptance of rotary blood pump (RBP) in clinical use over the past decades, the diminished flow pulsatility generated by a fixed speed RBP has been regarded as a potential factor that may lead to adverse events such as vasculature stiffening and hemorrhagic strokes. In this study, we investigate the feasibility of generating physiological pulse pressure in the pulmonary circulation by modulating the speed of a right ventricular assist device (RVAD) in a mock circulation loop. A rectangular pulse profile with predetermined pulse width has been implemented as the pump speed pattern with two different phase shifts (0% and 50%) with respect to the ventricular contraction. In addition, the performance of the speed modulation strategy has been assessed under different cardiovascular states, including variation in ventricular contractility and pulmonary arterial compliance. Our results indicated that the proposed pulse profile with optimised parameters (Apulse = 10000 rpm and ωmin = 3000 rpm) was able to generate pulmonary arterial pulse pressure within the physiological range (9-15 mmHg) while avoiding undesirable pump backflow under both co- and counter-pulsation modes. As compared to co-pulsation, stroke work was reduced by over 44% under counter-pulsation, suggesting that mechanical workload of the right ventricle can be efficiently mitigated through counter-pulsing the pump speed. Furthermore, our results showed that improved ventricular contractility could potentially lead to higher risk of ventricular suction and pump backflow, while stiffening of the pulmonary artery resulted in increased pulse pressure. In conclusion, the proposed speed modulation strategy produces pulsatile hemodynamics, which is more physiologic than continuous blood flow. The findings also provide valuable insight into the interaction between RVAD speed modulation and the pulmonary circulation under various cardiovascular states.

Polycystic ovarian disease unmasked by pulsatile GnRH therapy in a subgroup of women with hypothalamic amenorrhea.

Science.gov (United States)

Mattle, Verena; Bilgyicildirim, Aysen; Hadziomerovic, Dijana; Ott, Helmut W; Zervomanolakis, Ioannis; Leyendecker, Gerhard; Wildt, Ludwig

2008-02-01

To present the observation in six out of 120 women treated with pulsatile GnRH for ovulation induction, who developed hyperandrogenemia and polycystic ovaries during treatment. Clinical observation. Department of Gynecologic Endocrinology and Reproductive Medicine, Medical University of Innsbruck, Austria. A total of 120 women initially diagnosed as suffering from primary or secondary hypothalamic amenorrhea were treated for ovulation induction with pulsatile administration of GnRH for up to 140 days. There was no indication of the presence of polycystic ovaries or hyperandrogenemia before therapy. Pulsatile GnRH therapy using the Zyklomat pump. Ovulatory menstrual cycles. Initially, all patients responded to pulsatile GnRH administration with ovulation and corpus luteum formation. During continuation of treatment, 6 patients developed an increase in LH and LH/FSH ratio as well as a progressive rise in serum T levels resulting in hyperandrogenemia. This was accompanied by the development of polycystic ovaries and cessation of follicular maturation. We conclude from these observations that restoration of normal GnRH stimulation of the pituitary gland can result in the development of hyperandrogenemia and polycystic ovaries, suggesting a pituitary or ovarian defect underlying the pathogenesis of this disorder.

Obstructive Hydrocephalus Secondary to Enlarged Virchow-Robin Spaces: A Rare Cause of Pulsatile Tinnitus.

Science.gov (United States)

Donaldson, Christopher; Chatha, Gurkirat; Chandra, Ronil V; Goldschlager, Tony

2017-05-01

Obstructive hydrocephalus secondary to enlarged Virchow-Robin Spaces (VRS) is a rare entity, with only a few cases reported in the literature. Presenting symptoms vary widely from headaches to dizziness. We report a case of a 31-year-old man who presented with pulsatile tinnitus and magnetic resonance imaging showing obstructive hydrocephalus secondary to tumefactive VRS. After a cerebrospinal fluid diversion procedure in the form of an endoscopic third ventriculostomy, he had almost complete resolution of his symptoms. This is the first case of obstructive hydrocephalus secondary to enlarged VRS, presenting with pulsatile tinnitus. Copyright © 2017 Elsevier Inc. All rights reserved.

Pulsatile dry cupping in chronic low back pain - a randomized three-armed controlled clinical trial.

Science.gov (United States)

Teut, M; Ullmann, A; Ortiz, M; Rotter, G; Binting, S; Cree, M; Lotz, F; Roll, S; Brinkhaus, B

2018-04-02

We aimed to investigate the effectiveness of two different forms of dry pulsatile cupping in patients with chronic low back pain (cLBP) compared to medication on demand only in a three-armed randomized trial. 110 cLBP patients were randomized to regular pulsatile cupping with 8 treatments plus paracetamol on demand (n = 37), minimal cupping with 8 treatments plus paracetamol on demand (n = 36) or the control group with paracetamol on demand only (n = 37). Primary outcome was the pain intensity on a visual analogue scale (VAS, 0-100 mm) after 4 weeks, secondary outcome parameter included VAS pain intensity after 12 weeks, back function as measured with the 'Funktionsfragebogen Hannover Rücken' (FFbH-R) and health related quality of life questionnaire Short form 36 (SF-36) after 4 and 12 weeks. The mean baseline-adjusted VAS after 4 weeks was 34.9 mm (95% CI: 28.7; 41.2) for pulsatile cupping, 40.4 (34.2; 46.7) for minimal cupping and 56.1 (49.8; 62.4) for control group, resulting in statistically significant differences between pulsatile cupping vs. control (21.2 (12.2; 30.1); p back function after 4 weeks, but not after 12 weeks (- 5.4 (- 11.7;0.8); p = 0.088), pulsatile cupping also showed better improvements on SF-36 physical component scale compared to control at 4 and 12 weeks (- 5.6 (- 9.3;-2.0); p = 0.003; - 6.1 (- 9.9;-2.4); p = 0.002). For back function and quality of life minimal cupping group was not statistically different to control after 4 and 12 weeks. Paracetamol intake did not differ between the groups (cupping vs. control (7.3 (- 0.4;15.0); p = 0.063); minimal cupping vs. control (6.3 (- 2.0;14.5); p = 0.133). Both forms of cupping were effective in cLBP without showing significant differences in direct comparison after four weeks, only pulsatile cupping showed effects compared to control after 12 weeks. The study was registered at ClinicalTrials.gov (identifier: NCT02090686 ).

Renal artery pulsatility index and renal volume: Normal fetuses versus growth-retarded fetuses

International Nuclear Information System (INIS)

Lee, Kyung Soon; Woo, Bock Hi

2001-01-01

To evaluate the blood flow velocity waveform of the renal artery and renal volume of growth-retarded fetuses and to compare them with those of normal fetuses. Pulsatility index of the renal artery and renal volume measured by three-dimensional ultrasonography were obtained from seventy eight normal fetuses at the gestational age from twenty five to thirty nine weeks and eighteen intrauterine growth retarded fetuses whose weight was below ten percentile at birth. We studied changes of the pulsatility index of the renal artery and renal volume according to the gestational age and compared with those of growth-retarded fetuses. Pulsatility index (PI) of the fetal renal artery decreased throughout the gestational period (r=0.703, p<0.0001). In growth-retarded fetuses, despite of abnormal doppler velocity waveform of the middle cerebral artery, which was showing fetal hypoxia, the renal PI was not increased significantly. The fetal renal volume increased throughout the gestational period (r=0.834, p<0.0001) whereas in growth-retarded fetuses, all renal volume was below fifth percentile of normal fetuses. In growth-retarded fetuses, fetal renal volume was decreased significantly without change of the renal vascular flow. Therefore, the fetal renal volume measured by three-dimensional ultrasonography may be a helpful parameter in the diagnosis of growth-retarded fetuses.

Renal artery pulsatility index and renal volume: Normal fetuses versus growth-retarded fetuses

Energy Technology Data Exchange (ETDEWEB)

Lee, Kyung Soon; Woo, Bock Hi [Ewha Womans University College of Medicine, Seoul (Korea, Republic of)

2001-06-15

To evaluate the blood flow velocity waveform of the renal artery and renal volume of growth-retarded fetuses and to compare them with those of normal fetuses. Pulsatility index of the renal artery and renal volume measured by three-dimensional ultrasonography were obtained from seventy eight normal fetuses at the gestational age from twenty five to thirty nine weeks and eighteen intrauterine growth retarded fetuses whose weight was below ten percentile at birth. We studied changes of the pulsatility index of the renal artery and renal volume according to the gestational age and compared with those of growth-retarded fetuses. Pulsatility index (PI) of the fetal renal artery decreased throughout the gestational period (r=0.703, p<0.0001). In growth-retarded fetuses, despite of abnormal doppler velocity waveform of the middle cerebral artery, which was showing fetal hypoxia, the renal PI was not increased significantly. The fetal renal volume increased throughout the gestational period (r=0.834, p<0.0001) whereas in growth-retarded fetuses, all renal volume was below fifth percentile of normal fetuses. In growth-retarded fetuses, fetal renal volume was decreased significantly without change of the renal vascular flow. Therefore, the fetal renal volume measured by three-dimensional ultrasonography may be a helpful parameter in the diagnosis of growth-retarded fetuses.

Leaback of Pulsatile Flow of Particle Fluid Suspension Model of ...

African Journals Online (AJOL)

Leaback of Pulsatile Flow of Particle Fluid Suspension Model of Blood Under Periodic Body Acceleration. ... The variation in body acceleration amplitude though affects the velocity profile in the capillary tubes, it has no effect on the leakback in the tubes. Leakback is mainly determined by the balance of the viscous drag and ...

A study of doppler waveform using pulsatile flow model

International Nuclear Information System (INIS)

Chung, Hye Won; Chung, Myung Jin; Park, Jae Hyung; Chung, Jin Wook; Lee, Dong Hyuk; Min, Byoung Goo

1997-01-01

Through the construction of a pulsatile flow model using an artificial heart pump and stenosis to demonstrate triphasic Doppler waveform, which simulates in vivo conditions, and to evaluate the relationship between Doppler waveform and vascular compliance. The flow model was constructed using a flowmeter, rubber tube, glass tube with stenosis, and artificial heart pump. Doppler study was carried out at the prestenotic, poststenotic, and distal segments;compliance was changed by changing the length of the rubber tube. With increasing proximal compliance, Doppler waveforms show decreasing peak velocity of the first phase and slightly delayed acceleration time, but the waveform itself did not change significantly. Distal compliance influenced the second phase, and was important for the formation of pulsus tardus and parvus, which without poststenotic vascular compliance, did not develop. The peak velocity of the first phase was inversely proportional to proximal compliance, and those of the second and third phases were directly proportional to distal compliance. After constructing this pulsatile flow model, we were able to explain the relationship between vascular compliance and Doppler waveform, and also better understand the formation of pulsus tardus and parvus

Colon-specific pulsatile drug release provided by electrospun shellac nanocoating on hydrophilic amorphous composites.

Science.gov (United States)

Yang, Yao-Yao; Liu, Zhe-Peng; Yu, Deng-Guang; Wang, Ke; Liu, Ping; Chen, Xiaohong

2018-01-01

Colon-specific pulsatile drug release, as a combined drug controlled-release model, is a useful drug delivery manner for a series of diseases. New nanomedicines and related preparation methods are highly desired. With diclofenac sodium (DS) as a model drug, a new type of structural nanocomposite (SC), in which composite polyvinylpyrrolidone (PVP)-DS core was coated by shellac, was fabricated via modified coaxial electrospinning. For comparison, traditional PVP-DS monolithic hydrophilic nanocomposites (HCs) were generated using a traditional blending process. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), attenuated total reflectance-Fourier transform infrared (ATR-FTIR), water contact angle (WCA), and in vitro dissolution and ex vivo permeation tests were conducted to characterize the composites. SEM images demonstrated that both composites were linear nanofibers with smooth surface morphology and cross sections. TEM disclosed that the SCs had a thin shellac sheath layer of approximately 12 nm. XRD and ATR-FTIR results demonstrated that the crystalline DS was converted into amorphous composites with PVP because of favorable secondary interactions. WCA and in vitro dissolution tests demonstrated that the sheath shellac layers in SC could resist acid conditions and provide typical colon-specific pulsatile release, rather than a pulsatile release of HC under acid conditions. Ex vivo permeation results demonstrated that the SCs were able to furnish a tenfold drug permeation rate than the DS particles on the colon membrane. A new SC with a shellac coating on hydrophilic amorphous nanocomposites could furnish a colon-specific pulsatile drug release profile. The modified coaxial process can be exploited as a useful tool to create nanocoatings.

Evaluation of pulsatile plasma concentrations of growth hormone in healthy dogs and dogs with dilated cardiomyopathy

NARCIS (Netherlands)

Beijerink, N.J.; Lee, W.M.; Stokhof, A.A.; Voorhout, G.; Mol, J.A.; Kooistra, H.S.

2011-01-01

Abstract OBJECTIVE: To evaluate plasma concentrations of growth hormone (GH) and insulin-like growth factor I (IGF-I) in healthy dogs and large-breed dogs with dilated cardiomyopathy (DCM). ANIMALS: 8 dogs with DCM and 8 healthy control dogs of comparable age and body weight. PROCEDURES: Blood

Induction of pulsatile secretion of leptin in horses following thyroidectomy.

Science.gov (United States)

Buff, Preston R; Messer, Nat T; Cogswell, Andria M; Wilson, David A; Johnson, Philip J; Keisler, Duane H; Ganjam, Venkataseshu K

2007-02-01

Endocrine characteristics of Quarter Horse-type mares were determined during a 68 h feed deprivation and again in the same mares following surgical thyroidectomy (THX). A crossover experimental design was implemented, in which mares received brome hay available ad libitum (FED) or were food deprived (RES) for 68 h. Blood samples were collected every 20 min for 48 h, beginning 20 h after the onset of food deprivation. Concentrations of triiodothyronine and thyroxine were undetectable post-THX. Plasma concentrations of thyrotropin were greater post-THX versus pre-THX (P<0 x 001). Plasma concentrations of leptin were greater in the THX FED group than in the THX RES group (P<0 x 01). The existence of leptin pulse secretion was found only in post-THX compared with the same horses pre-THX (P=0 x 02). We theorize that non-pulsatile secretion of leptin may have contributed to the survival of this species, as it evolved in the regions of seasonal availability of food. Lack of pulsatile secretion of leptin may contribute to the accumulation of energy stores by modulating leptin sensitivity.

Arterial stiffness, pressure and flow pulsatility and brain structure and function: the Age, Gene/Environment Susceptibility--Reykjavik study.

Science.gov (United States)

Mitchell, Gary F; van Buchem, Mark A; Sigurdsson, Sigurdur; Gotal, John D; Jonsdottir, Maria K; Kjartansson, Ólafur; Garcia, Melissa; Aspelund, Thor; Harris, Tamara B; Gudnason, Vilmundur; Launer, Lenore J

2011-11-01

Aortic stiffness increases with age and vascular risk factor exposure and is associated with increased risk for structural and functional abnormalities in the brain. High ambient flow and low impedance are thought to sensitize the cerebral microcirculation to harmful effects of excessive pressure and flow pulsatility. However, haemodynamic mechanisms contributing to structural brain lesions and cognitive impairment in the presence of high aortic stiffness remain unclear. We hypothesized that disproportionate stiffening of the proximal aorta as compared with the carotid arteries reduces wave reflection at this important interface and thereby facilitates transmission of excessive pulsatile energy into the cerebral microcirculation, leading to microvascular damage and impaired function. To assess this hypothesis, we evaluated carotid pressure and flow, carotid-femoral pulse wave velocity, brain magnetic resonance images and cognitive scores in participants in the community-based Age, Gene/Environment Susceptibility--Reykjavik study who had no history of stroke, transient ischaemic attack or dementia (n = 668, 378 females, 69-93 years of age). Aortic characteristic impedance was assessed in a random subset (n = 422) and the reflection coefficient at the aorta-carotid interface was computed. Carotid flow pulsatility index was negatively related to the aorta-carotid reflection coefficient (R = -0.66, Pwave velocity were each associated with increased risk for silent subcortical infarcts (hazard ratios of 1.62-1.71 per standard deviation, Pwave velocity was associated with higher white matter hyperintensity volume (0.108 ± 0.045 SD/SD, P = 0.018). Pulsatility index was associated with lower whole brain (-0.127 ± 0.037 SD/SD, Pwave velocity (-0.095 ± 0.043 SD/SD, P = 0.028) and carotid pulse pressure (-0.114 ± 0.045 SD/SD, P = 0.013) were associated with lower memory scores. Pulsatility index was associated with lower memory scores (-0.165 ± 0.039 SD/SD, Pwave

Pulsatile turbulent flow through pipe bends at high Dean and Womersley numbers

Science.gov (United States)

Kalpakli, Athanasia; Örlü, Ramis; Tillmark, Nils; Alfredsson, P. Henrik

2011-12-01

Turbulent pulsatile flows through pipe bends are prevalent in internal combustion engine components which consist of bent pipe sections and branching conduits. Nonetheless, most of the studies related to pulsatile flows in pipe bends focus on incompressible, low Womersley and low Dean number flows, primarily because they aim in modeling blood flow, while internal combustion engine related flows have mainly been addressed in terms of integral quantities and consist of single point measurements. The present study aims at bridging the gap between these two fields by means of time-resolved stereoscopic particle image velocimetry measurements in a pipe bend with conditions that are close to those encountered in exhaust manifolds. The time/phase-resolved three-dimensional cross-sectional flow-field 3 pipe diameters downstream the pipe bend is captured and the interplay between different secondary motions throughout a pulse cycle is discussed.

Pulsatile turbulent flow through pipe bends at high Dean and Womersley numbers

International Nuclear Information System (INIS)

Kalpakli, Athanasia; Örlü, Ramis; Tillmark, Nils; Alfredsson, P Henrik

2011-01-01

Turbulent pulsatile flows through pipe bends are prevalent in internal combustion engine components which consist of bent pipe sections and branching conduits. Nonetheless, most of the studies related to pulsatile flows in pipe bends focus on incompressible, low Womersley and low Dean number flows, primarily because they aim in modeling blood flow, while internal combustion engine related flows have mainly been addressed in terms of integral quantities and consist of single point measurements. The present study aims at bridging the gap between these two fields by means of time-resolved stereoscopic particle image velocimetry measurements in a pipe bend with conditions that are close to those encountered in exhaust manifolds. The time/phase-resolved three-dimensional cross-sectional flow-field 3 pipe diameters downstream the pipe bend is captured and the interplay between different secondary motions throughout a pulse cycle is discussed.

Verification of a computational cardiovascular system model comparing the hemodynamics of a continuous flow to a synchronous valveless pulsatile flow left ventricular assist device.

Science.gov (United States)

Gohean, Jeffrey R; George, Mitchell J; Pate, Thomas D; Kurusz, Mark; Longoria, Raul G; Smalling, Richard W

2013-01-01

The purpose of this investigation is to use a computational model to compare a synchronized valveless pulsatile left ventricular assist device with continuous flow left ventricular assist devices at the same level of device flow, and to verify the model with in vivo porcine data. A dynamic system model of the human cardiovascular system was developed to simulate the support of a healthy or failing native heart from a continuous flow left ventricular assist device or a synchronous pulsatile valveless dual-piston positive displacement pump. These results were compared with measurements made during in vivo porcine experiments. Results from the simulation model and from the in vivo counterpart show that the pulsatile pump provides higher cardiac output, left ventricular unloading, cardiac pulsatility, and aortic valve flow as compared with the continuous flow model at the same level of support. The dynamic system model developed for this investigation can effectively simulate human cardiovascular support by a synchronous pulsatile or continuous flow ventricular assist device.

The Two Populations of Kisspeptin Neurons Are Involved in the Ram-Induced LH Pulsatile Secretion and LH Surge in Anestrous Ewes.

Science.gov (United States)

Fabre-Nys, Claude; Cognié, Juliette; Dufourny, Laurence; Ghenim, Meriem; Martinet, Stephanie; Lasserre, Olivier; Lomet, Didier; Millar, Robert P; Ohkura, Satoshi; Suetomi, Yuta

2017-11-01

Exposure to a ram during spring stimulates luteinizing hormone (LH) secretion and can induce ovulation in sexually quiescent ewes ("ram effect"). Kisspeptin (Kiss) present in the arcuate nucleus (ARC) and the preoptic area (POA) is a potent stimulators of LH secretion. Our aim was to investigate whether Kiss neurons mediate the increase in LH secretion during the ram effect. With double immunofluorescent detection, we identified Kiss neurons (Kiss IR) activated (Fos IR) by exposure to a ram for 2 hours (M2) or 12 hours (M12) or to ewes for 2 hours (C). The density of cells Kiss + Fos IR and the proportion of Kiss IR cells that were also Fos IR cells were higher in M2 and M12 than in C in ARC (P populations of Kiss neurons are involved in the ram-induced pulsatile LH secretion and in the LH surge. Copyright © 2017 Endocrine Society.

A Novel Approach to Flurbiprofen Pulsatile Colonic Release: Formulation and Pharmacokinetics of Double-Compression-Coated Mini-Tablets.

Science.gov (United States)

Vemula, Sateesh Kumar

2015-12-01

A significant plan is executed in the present study to study the effect of double-compression coating on flurbiprofen core mini-tablets to achieve the pulsatile colonic delivery to deliver the drug at a specific time as per the patho-physiological need of the disease that results in improved therapeutic efficacy. In this study, pulsatile double-compression-coated tablets were prepared based on time-controlled hydroxypropyl methylcellulose K100M inner compression coat and pH-sensitive Eudragit S100 outer compression coat. Then, the tablets were evaluated for both physical evaluation and drug-release studies, and to prove these results, in vivo pharmacokinetic studies in human volunteers were conducted. From the in vitro drug-release studies, F6 tablets were considered as the best formulation, which retarded the drug release in the stomach and small intestine (3.42 ± 0.12% in 5 h) and progressively released to the colon (99.78 ± 0.74% in 24 h). The release process followed zero-order release kinetics, and from the stability studies, similarity factor between dissolution data before and after storage was found to be 88.86. From the pharmacokinetic evaluation, core mini-tablets producing peak plasma concentration (C max) was 14,677.51 ± 12.16 ng/ml at 3 h T max and pulsatile colonic tablets showed C max = 12,374.67 ± 16.72 ng/ml at 12 h T max. The area under the curve for the mini and pulsatile tablets was 41,238.52 and 72,369.24 ng-h/ml, and the mean resident time was 3.43 and 10.61 h, respectively. In conclusion, development of double-compression-coated tablets is a promising way to achieve the pulsatile colonic release of flurbiprofen.

Pulsatile fluidic pump demonstration and predictive model application

International Nuclear Information System (INIS)

Morgan, J.G.; Holland, W.D.

1986-04-01

Pulsatile fluidic pumps were developed as a remotely controlled method of transferring or mixing feed solutions. A test in the Integrated Equipment Test facility demonstrated the performance of a critically safe geometry pump suitable for use in a 0.1-ton/d heavy metal (HM) fuel reprocessing plant. A predictive model was developed to calculate output flows under a wide range of external system conditions. Predictive and experimental flow rates are compared for both submerged and unsubmerged fluidic pump cases

Secondary flow structures in a 180∘ elastic curved vessel with torsion under steady and pulsatile inflow conditions

Science.gov (United States)

Najjari, Mohammad Reza; Plesniak, Michael W.

2017-11-01

Secondary flow vortical structures were investigated in an elastic 180° curved pipe with and without torsion under steady and pulsatile flow using particle image velocimetry (PIV). The elastic thin-walled curved pipes were constructed using Sylgard 184, and inserted into a bath of refractive index matched fluid to perform PIV. A vortex identification method was employed to identify various vortical structures in the flow. The secondary flow structures in the planar compliant model with dilatation of 0.61%-3.23% under pulsatile flow rate were compared with the rigid vessel model results, and it was found that local vessel compliance has a negligible effect on secondary flow morphology. The secondary flow structures were found to be more sensitive to out of plane curvature (torsion) than to vessel compliance. Torsion distorts the symmetry of secondary flow and results in more complex vortical structures in both steady and pulsatile flows. In high Re number steady flow with torsion, a single dominant vortical structure can be detected at the middle of the 90° cross section. In pulsatile flow with torsion, the split-Dean and Lyne-type vortices with same rotation direction originating from opposite sides of the cross section tend to merge together. supported by GW Center for Biomimetics and Bioinspired Engineering.

An intriguing design concept to enhance the pulsatile fatigue life of self-expanding stents.

Science.gov (United States)

Hsiao, Hao-Ming; Yin, Ming-Ting

2014-02-01

Intravascular stenting has emerged as the primary treatment for vascular diseases and has received great attention from the medical community since its introduction two decades ago. The endovascular self-expanding stent is used to treat peripheral artery diseases; however, once implanted, these stents suffer from various cyclic motions caused by pulsatile blood pressure and daily activities. Due to this challenging environment, fatigue performance has become a critical issue for stent design. In this paper, a simple yet intriguing concept of stent design aimed at enhancing pulsatile fatigue life is investigated. The concept of this design is to shift the highly concentrated stresses/strains away from the crown and re-distribute them along the stress-free bar arm by tapering its strut width. Finite element models were developed to evaluate the mechanical integrity and pulsatile fatigue resistance of the stent to various loading conditions. Results show that the fatigue safety factor jumped to 2.5-3.0 times that of the standard stent with constant strut width. This is astonishing considering that the stent profile and scaffolding were not compromised. The findings of this paper provide an excellent approach to the optimization of future stent design to greatly improve stent fatigue performance.

Generating pulsatility by pump speed modulation with continuous-flow total artificial heart in awake calves.

Science.gov (United States)

Fukamachi, Kiyotaka; Karimov, Jamshid H; Sunagawa, Gengo; Horvath, David J; Byram, Nicole; Kuban, Barry D; Dessoffy, Raymond; Sale, Shiva; Golding, Leonard A R; Moazami, Nader

2017-12-01

The purpose of this study was to evaluate the effects of sinusoidal pump speed modulation of the Cleveland Clinic continuous-flow total artificial heart (CFTAH) on hemodynamics and pump flow in an awake chronic calf model. The sinusoidal pump speed modulations, performed on the day of elective sacrifice, were set at ±15 and ± 25% of mean pump speed at 80 bpm in four awake calves with a CFTAH. The systemic and pulmonary arterial pulse pressures increased to 12.0 and 12.3 mmHg (±15% modulation) and to 15.9 and 15.7 mmHg (±25% modulation), respectively. The pulsatility index and surplus hemodynamic energy significantly increased, respectively, to 1.05 and 1346 ergs/cm at ±15% speed modulation and to 1.51 and 3381 ergs/cm at ±25% speed modulation. This study showed that it is feasible to generate pressure pulsatility with pump speed modulation; the platform is suitable for evaluating the physiologic impact of pulsatility and allows determination of the best speed modulations in terms of magnitude, frequency, and profiles.

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

Ghrelin: ghrelin as a regulatory Peptide in growth hormone secretion.

Science.gov (United States)

Khatib, Nazli; Gaidhane, Shilpa; Gaidhane, Abhay M; Khatib, Mahanaaz; Simkhada, Padam; Gode, Dilip; Zahiruddin, Quazi Syed

2014-08-01

Ghrelin is a type of growth hormone (GH) secretagogue that stimulates the release of GH. It is a first hormone linking gastrointestinal-pituitary axis. This review highlights the interaction of ghrelin with GHRH and somatostatin to regulate the secretion of GH and intends to explore the possible physiological role of the ghrelin-pituitary-GH axis linkage system. Ghrelin is highly conserved among species and is classified into octanoylated (C8:0), decanoylated (C10:0), decenoylated (C10:1) and nonacylated,ghrelin. Acylated ghrelin is the major active form of human ghrelin. The primary production site of ghrelin is the stomach, and it interacts with stomach ghrelin as well as hypothalamic GHRH and somatostatin in the regulation of pituitary GH secretion. Ghrelin stimulate GH release through the GHS receptor to increase intracellular Ca2+ ([Ca2+] levels via IP3 signal transduction pathway. Ghrelin is a specific endogenous ligand for the GHS receptor and provides a definitive proof of the occurance of a GHS-GHS receptor signalling system in the regulation of GH secretion. Studies suggests that ghrelin is a powerful pharmacological agent that exerts a potent, time-dependent stimulation of pulsatile secretion of GH.

Estriol administration modulates luteinizing hormone secretion in women with functional hypothalamic amenorrhea.

Science.gov (United States)

Genazzani, Alessandro D; Meczekalski, Blazej; Podfigurna-Stopa, Agnieszka; Santagni, Susanna; Rattighieri, Erica; Ricchieri, Federica; Chierchia, Elisa; Simoncini, Tommaso

2012-02-01

To evaluate the influence of estriol administration on the hypothalamus-pituitary function and gonadotropins secretion in patients affected by functional hypothalamic amenorrhea (FHA). Controlled clinical study. Patients with FHA in a clinical research environment. Twelve hypogonadotropic patients affected by FHA. Pulsatility study of luteinizing hormone (LH) and follicle-stimulating hormone (FSH), and a gonadotropin-releasing hormone (GnRH) test (10 μg in bolus) at baseline condition and after 8 weeks of therapy with 2 mg/day of estriol. Measurements of plasma LH, FSH, estradiol (E(2)), androstenedione (A), 17α-hydroxyprogesterone (17-OHP), cortisol, androstenedione (A), testosterone (T), thyroid-stimulating hormone (TSH), free triiodothyronine (fT(3)), free thyroxine (fT(4)), and insulin, and pulse detection. After treatment, the FHA patients showed a statistically significant increase of LH plasma levels (from 0.7 ± 0.1 mIU/mL to 3.5 ± 0.3 mIU/mL) and a statistically significant increase of LH pulse amplitude with no changes in LH pulse frequency. In addition, the LH response to the GnRH bolus was a statistically significant increase. Estriol administration induced the increase of LH plasma levels in FHA and improved GnRH-induced LH secretion. These findings suggest that estriol administration modulates the neuroendocrine control of the hypothalamus-pituitary unit and induces the recovery of LH synthesis and secretion in hypogonadotropic patients with FHA. Copyright © 2012 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Lutropin alpha, recombinant human luteinizing hormone, for the stimulation of follicular development in profoundly LH-deficient hypogonadotropic hypogonadal women: a review

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Bernd Th Krause

2009-06-01

Full Text Available Bernd Th Krause1, Ralf Ohlinger2, Annette Haase31Center for Endocrinology and Reproductive Medicine, MVZ Uhlandstr, Berlin, Germany; 2Ernst-Moritz-Arndt-University, Department of Gynecology and Obstetrics, Greifswald, Germany; 3Uhlandstr. 162, 10719 BerlinAbstract: Hypogonadotropic hypogonadism is defined as a medical condition with low or undetectable gonadotropin secretion, associated with a complete arrest of follicular growth and very low estradiol. The main cause can be traced back to an irregular or absent hypothalamic GnRH secretion, whereas only a minority suffers from a pituitary disorder. The choice of treatment to reverse this situation is a pulsatile GnRH application or a direct ovarian stimulation using gonadotropin injections. The goal is to achieve a proper ovarian function in these cases for a short time to allow ovulation and chance of pregnancy. Since the pulsatile GnRH treatment lost its former importance, several gonadotropins are in use to stimulate follicular growth, such as urine-derived human menopausal gonadotropin, highly purified follicle stimulating hormone (FSH or recombinant FSH, all with different success. The introduction of recombinant luteinizing hormone (LH and FSH provided an opportunity to investigate the distinct influences of LH and FSH alone and in combination on follicular growth in monofollicular ovulation induction cycles, and additionally on oocyte maturation, fertilization competence of the oocyte and embryo quality in downregulated IVF patients. Whereas FSH was known to be indispensable for normal follicular growth, the role of LH remained questionable. Downregulated IVF patients with this short-term gonadotropin depletion displayed no advance in stimulation success with the use of recombinant LH. Patients with hypogonadotropic hypogonadism undergoing monofollicular stimulation for ovulation induction showed clearly a specific role and need for both hormones in normal follicular growth. Therefore, a

Tolerance to continuous intrathecal baclofen infusion can be reversed by pulsatile bolus infusion

NARCIS (Netherlands)

Heetla, H. W.; Staal, M. J.; van Laar, T.

Study design: Pilot study. Objective: To study the effect of pulsatile bolus infusion of intrathecal baclofen (ITB) on daily ITB dose, in patients showing dose increases, probably due to tolerance. Setting: Department of neurology and neurosurgery, University Medical Center Groningen, the

Neuroanatomical Alterations in Patients with Early Stage of Unilateral Pulsatile Tinnitus: A Voxel-Based Morphometry Study

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Yawen Liu

2018-01-01

Full Text Available During the past several years, the rapid development of neuroimaging techniques has contributed greatly in the noninvasive imaging studies of tinnitus. The aim of the present study was to explore the brain anatomical alterations in patients with right-sided unilateral pulsatile tinnitus (PT in the early stage of PT symptom using voxel-based morphometry (VBM analysis. Twenty-four patients with right-sided pulsatile tinnitus and 24 age- and gender-matched normal controls were recruited to this study. Structural image data preprocessing was performed using VBM8 toolbox. Tinnitus Handicap Inventory (THI score was acquired in the tinnitus group to assess the severity of tinnitus and tinnitus-related distress. Two-sample t-test and Pearson’s correlation analysis were used in statistical analysis. Patients with unilateral pulsatile tinnitus had significantly increased gray matter (GM volume in bilateral superior temporal gyrus compared with the normal controls. However, the left cerebellum posterior lobe, left frontal superior orbital lobe (gyrus rectus, right middle occipital gyrus (MOG, and bilateral putamen showed significantly decreased brain volumes. This was the first study which demonstrated the features of neuroanatomical changes in patients with unilateral PT during their early stages of the symptom.

INFLUENCE OF PULSATILE FLOW ON THE BEHAVIOR OF HUMAN FIBROBLASTS ADHERED TO GLASS

NARCIS (Netherlands)

VANKOOTEN, TG; SCHAKENRAAD, JM; VANDERMEI, HC; BUSSCHER, HJ

1993-01-01

In the human body, cells contacting biomaterials surfaces are frequently exposed to pulsatile shear stresses, e.g. blood vessel prostheses. Most studies involving shear, however, try to achieve a steady, pulse-free shear stress in studying cell-biomaterial interactions. In this study, human

Pulsatile secretion of thyrotropin during fasting: a decrease of thyrotropin pulse amplitude

NARCIS (Netherlands)

Romijn, J. A.; Adriaanse, R.; Brabant, G.; Prank, K.; Endert, E.; Wiersinga, W. M.

1990-01-01

The effect of fasting on circadian and pulsatile TSH secretion was investigated in eight healthy subjects (four men and four women in the follicular phase). Each subject was studied twice, once during 24 h with normal food intake and once during the last 24 h of a 60-h fast. Blood was sampled every

Pulsatile Hyperglycaemia Induces Vascular Oxidative Stress and GLUT 1 Expression More Potently than Sustained Hyperglycaemia in Rats on High Fat Diet

DEFF Research Database (Denmark)

Rakipovski, Gunaj; Lykkesfeldt, Jens; Raun, Kirsten

2016-01-01

expression of glucose transporter 1 (GLUT1), gp-91(PHOX) and super oxide dismutase (SOD), while only the PLG group showed increased accumulation of oxidative stress and oxidised low density lipoprotein (oxLDL) in aorta. Conclusion Pulsatile hyperglycaemia induced relatively higher levels of oxidative stress......Introduction Pulsatile hyperglycaemia resulting in oxidative stress may play an important role in the development of macrovascular complications. We investigated the effects of sustained vs. pulsatile hyperglycaemia in insulin resistant rats on markers of oxidative stress, enzyme expression...... and glucose metabolism in liver and aorta. We hypothesized that liver's ability to regulate the glucose homeostasis under varying states of hyperglycaemia may indirectly affect oxidative stress status in aorta despite the amount of glucose challenged with. Methods Animals were infused with sustained high (SHG...

Experimental study on quantitative evaluation of slow pulsatile flow of CSF with cine MRI

International Nuclear Information System (INIS)

Matsuda, Masao

1991-01-01

The present study was designed to evaluate the slow pulsatile flow of cerebrospinal fluid (CSF) quantitatively with cine MRI in phantom experiment for the clinical application. The flow phantom was constructed from a plastic tube with a narrow channel to represent the central aqueduct. The phantom was filled with water to represent the CSF. The second tube filled with stationary water was positioned beside the flow phantom and acted as a control for no-flow signal strength. The ratio of signal intensity in regions of interest for the flow phantom and the control was measured. Not only the actual velocity curve of the flowing water through the phantom but also the temporal profile of signal intensity showed two main peaks with other small peaks in one cycle. This suggested a close relationship between signal intensity of cine MRI and flow velocity. A significant correlation between the signal intensity ratio and the velocity was obtained on cine MRI pulse sequences. Cine MRI was thus found to have the ability to give quantitative information about slow pulsatile flow. The most suitable pulse sequence was fast imaging with steady state free precession pulse sequence at the flip angle between 50 and 90 degrees. This preliminary study suggests that the slow pulsatile flow of CSF passing along the aqueduct can be visualized and measured. Thus, the sequence proposed has a potential for the investigation of normal and disturbed CSF circulation and the mapping of the flow pattern in different pathological conditions. (N.K.)

[Ovulation induction by pulsatile GnRH therapy in 2014: literature review and synthesis of current practice].

Science.gov (United States)

Gronier, H; Peigné, M; Catteau-Jonard, S; Dewailly, D; Robin, G

2014-10-01

The hypogonadotropic hypogonadism is an easily treatable form of female infertility. The most common cause of hypogonadotropic hypogonadism is functional hypothalamic amenorrhea. The GnRH pump is a simple and effective treatment to restore fertility of patients with hypothalamic amenorrhea: cumulative pregnancy rate is estimated between 70 and 100% after 6 cycles, compared to a low rate of complications and multiple pregnancies. While only 2.8 cycles are on average required to achieve a pregnancy with a pump, this induction of ovulation stays underused in France. The objective of this paper is to propose a practical manual of pulsatile GnRH, in order to improve the accessibility of pulsatile GnRH for patients with hypogonadotropic hypogonadism. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Real time monitoring of pulsatile change in hemoglobin concentrations of cerebral tissue by a portable tissue oximeter with a 10-Hz sampling rate

Science.gov (United States)

Shiga, Toshikazu; Chihara, Eiichi; Tanabe, Kazuhisa; Tanaka, Yoshifumi; Yamamoto, Katsuyuki

1998-01-01

A portable CW tissue oximeter of a 10-Hz sampling rate was developed for examination of pulsatile components of the output signals as a mean of checking the signal reliability during long-term monitoring. Feasible studies were performed on a healthy subject. Changes in Hb and HbO2 signals of cerebral tissue were continuously measured by placing a photoprobe on the forehead during 6-hour sleep. Pulsatile changes in Hb and HbO2 were steadily observed over a whole period of the recording. The phase relation of pulsation in Hb and HbO2 was almost inverse. Not only information for reliable monitoring but also physiological parameters with respect to cerebral circulation and metabolism could be obtained by measuring the pulsatile components.

Long-Term Durability Test for the Left Ventricular Assist System EVAHEART under the Physiologic Pulsatile Load.

Science.gov (United States)

Kitano, Tomoya; Iwasaki, Kiyotaka

The EVAHEART Left Ventricular Assist System (LVAS) was designed for the long-term support of a patient with severe heart failure. It has an original water lubrication system for seal and bearing and wear on these parts was considered one of its critical failure modes. A durability test focusing on wear was designed herein. We developed a mock loop, which generates a physiologic pulsatile flow and is sufficiently durable for a long-term test. The pulsatile load and the low fluid viscosity enable the creation of a severe condition for the mechanical seal. A total of 18 EVAHEART blood pumps completed 2 years of operation under the pulsatile condition without any failure. It indicated the EVAHEART blood pump had a greater than 90% reliability with a 88% confidence level. The test was continued with six blood pumps and achieved an average of 8.6 years, which was longer than the longest clinical use in Japan. The test result showed that no catastrophic, critical, marginal, or minor failures of the blood pump or their symptoms were observed. The seal performance was maintained after the test. Moreover, the surface roughness did not change, which showed any burn or abnormal wear occurred. The original water lubrication system equipped in EVAHEART LVAS prevent severe wear on the seal and the bearing, and it can be used in the bridge to transplant and destination therapy.

Pulsatile spiral blood flow through arterial stenosis.

Science.gov (United States)

Linge, Fabian; Hye, Md Abdul; Paul, Manosh C

2014-11-01

Pulsatile spiral blood flow in a modelled three-dimensional arterial stenosis, with a 75% cross-sectional area reduction, is investigated by using numerical fluid dynamics. Two-equation k-ω model is used for the simulation of the transitional flow with Reynolds numbers 500 and 1000. It is found that the spiral component increases the static pressure in the vessel during the deceleration phase of the flow pulse. In addition, the spiral component reduces the turbulence intensity and wall shear stress found in the post-stenosis region of the vessel in the early stages of the flow pulse. Hence, the findings agree with the results of Stonebridge et al. (2004). In addition, the results of the effects of a spiral component on time-varying flow are presented and discussed along with the relevant pathological issues.

A High Performance Pulsatile Pump for Aortic Flow Experiments in 3-Dimensional Models.

Science.gov (United States)

Chaudhury, Rafeed A; Atlasman, Victor; Pathangey, Girish; Pracht, Nicholas; Adrian, Ronald J; Frakes, David H

2016-06-01

Aortic pathologies such as coarctation, dissection, and aneurysm represent a particularly emergent class of cardiovascular diseases. Computational simulations of aortic flows are growing increasingly important as tools for gaining understanding of these pathologies, as well as for planning their surgical repair. In vitro experiments are required to validate the simulations against real world data, and the experiments require a pulsatile flow pump system that can provide physiologic flow conditions characteristic of the aorta. We designed a newly capable piston-based pulsatile flow pump system that can generate high volume flow rates (850 mL/s), replicate physiologic waveforms, and pump high viscosity fluids against large impedances. The system is also compatible with a broad range of fluid types, and is operable in magnetic resonance imaging environments. Performance of the system was validated using image processing-based analysis of piston motion as well as particle image velocimetry. The new system represents a more capable pumping solution for aortic flow experiments than other available designs, and can be manufactured at a relatively low cost.

The Effect of Pulsatile Flow on bMSC-Derived Endothelial-Like Cells in a Small-Sized Artificial Vessel Made by 3-Dimensional Bioprinting

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Kang Woog Lee

2018-01-01

Full Text Available Replacement of small-sized vessels is still challenging. This study is aimed at investigating the possibility of small-sized artificial vessels made by 3-dimensional bioprinting and the effect of pulsatile flow on bMSC-derived endothelial-like cells. Cells were harvested from rabbit bone marrow and primary cultured with or without growth factors. Endothelial differentiation was confirmed by the Matrigel tube formation assay, Western blot, and qRT-PCR. In addition, embedment of endothelial-like cells in an artificial vessel was made by 3-dimensional bioprinting, and the pulsatile flow was performed. For pumped and nonpumped groups, qRT-PCR was performed on CD31 and VE-cadherin gene expression. Endothelial-like cells showed increased gene expression of CD31 and VE-cadherin, and tube formation is observed at each week. Endothelial-like cells grow well in a small-sized artificial vessel made by 3-dimensional bioprinting and even express higher endothelial cell markers when they undergo pulsatile flow condition. Moreover, the pulsatile flow condition gives a positive effect for cell observation not only on the sodium alginate hydrogel layer but also on the luminal surface of the artificial vessel wall. We have developed an artificial vessel, which is a mixture of cells and carriers using a 3-dimensional bioprinting method, and applied pulsatile flow using a peristaltic pump, and we also demonstrated cell growth and differentiation into endothelial cells. This study suggests guidelines regarding a small-sized artificial vessel in the field of tissue engineering.

Partial thickness autologus calvarial bone orbitocranioplasty for a sphenorbital encephalocele presenting as pulsatile exophthalmos

OpenAIRE

Trivedi, Adarsh; Garg, Amrish Kumar; Hiran, Subodh

2015-01-01

Basal encephalocele accounts only 1.5% of all encephaloceles. But Sphenorbital encephalocele is the rarest cause of herniation of brain into orbit leading to pulsatile exphothalmos. Authors presenting a case of sphenorbital encephalocele in a 16 yrs old girl successsfully managed by orbitcranioplasty by partilal thickness autologus calvarial bone graft.

Intraindividual variation in levels of serum testosterone and other reproductive and adrenal hormones in men.

Science.gov (United States)

Brambilla, Donald J; O'Donnell, Amy B; Matsumoto, Alvin M; McKinlay, John B

2007-12-01

Estimates of intraindividual variation in hormone levels provide the basis for interpreting hormone measurements clinically and for developing eligibility criteria for trials of hormone replacement therapy. However, reliable systematic estimates of such variation are lacking. To estimate intraindividual variation of serum total, free and bioavailable testosterone (T), dihydrotestosterone (DHT), SHBG, LH, dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulphate (DHEAS), oestrone, oestradiol and cortisol, and the contributions of biological and assay variation to the total. Paired blood samples were obtained 1-3 days apart at entry and again 3 months and 6 months later (maximum six samples per subject). Each sample consisted of a pool of equal aliquots of two blood draws 20 min apart. Men aged 30-79 years were randomly selected from the respondents to the Boston Area Community Health Survey, a study of the health of the general population of Boston, MA, USA. Analysis was based on 132 men, including 121 who completed all six visits, 8 who completed the first two visits and 3 who completed the first four visits. Day-to-day and 3-month (long-term) intraindividual standard deviations, after transforming measurements to logarithms to eliminate the contribution of hormone level to intraindividual variation. Biological variation generally accounted for more of total intraindividual variation than did assay variation. Day-to-day biological variation accounted for more of the total than did long-term biological variation. Short-term variability was greater in hormones with pulsatile secretion (e.g. LH) than those that exhibit less ultradian variation. Depending on the hormone, the intraindividual standard deviations imply that a clinician can expect to see a difference exceeding 18-28% about half the time when two measurements are made on a subject. The difference will exceed 27-54% about a quarter of the time. Given the level of intraindividual variability in hormone

Prospective, randomized comparison between pulsatile GnRH therapy and combined gonadotropin (FSH+LH) treatment for ovulation induction in women with hypothalamic amenorrhea and underlying polycystic ovary syndrome.

Science.gov (United States)

Dubourdieu, Sophie; Fréour, Thomas; Dessolle, Lionel; Barrière, Paul

2013-05-01

To compare the efficacy of pulsatile GnRH therapy versus combined gonadotropins for ovulation induction in women with both hypothalamic amenorrhoea and polycystic ovarian syndrome (HA/PCOS) according to their current hypothalamic status. This single-centre, prospective, randomized study was conducted in the Nantes University Hospital, France. Thirty consecutive patients were treated for ovulation induction with either pulsatile GnRH therapy or combined gonadotropins (rFSH+rLH). Frequency of adequate ovarian response (mono- or bi-follicular) and clinical pregnancy rate were then compared between both groups. Ovarian response was similar in both groups with comparable frequency of adequate ovarian response (73% vs 60%), but the clinical pregnancy rate was significantly higher in the pulsatile GnRH therapy group than in the combined gonadotropin group (46% vs 0%). HA/PCOS is a specific subgroup of infertile women. Pulsatile GnRH therapy is an effective and safe method of ovulation induction that can be used successfully in these patients. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Secondary flow vortical structures in a 180∘ elastic curved vessel with torsion under steady and pulsatile inflow conditions

Science.gov (United States)

Najjari, Mohammad Reza; Plesniak, Michael W.

2018-01-01

Secondary flow structures in a 180∘ curved pipe model of an artery are studied using particle image velocimetry. Both steady and pulsatile inflow conditions are investigated. In planar curved pipes with steady flow, multiple (two, four, six) vortices are detected. For pulsatile flow, various pairs of vortices, i.e., Dean, deformed-Dean, Lyne-type, and split-Dean, are present in the cross section of the pipe at 90∘ into the bend. The effects of nonplanar curvature (torsion) and vessel dilatation on these vortical structures are studied. Torsion distorts the symmetric secondary flows (which exist in planar curvatures) and can result in formation of more complex vortical structures. For example, the split-Dean and Lyne-type vortices with same rotation direction originating from opposite sides of the cross section tend to merge together in pulsatile flow. The vortical structures in elastic vessels with dilatation (0.61%-3.23%) are also investigated and the results are compared with rigid model results. It was found that the secondary flow structures in rigid and elastic models are similar, and hence the local compliance of the vessel does not affect the morphology of secondary flow structures.

Glucose uptake and pulsatile insulin infusion: euglycaemic clamp and [3-3H]glucose studies in healthy subjects

International Nuclear Information System (INIS)

Schmitz, O.; Arnfred, J.; Hother Nielsen, O.; Beck-Nielsen, H.; Oerskov, H.

1986-01-01

To test the hypothesis that insulin has a greater effect on glucose metabolism when given as pulsatile than as continuous infusion, a 354-min euglycaemic clamp study was carried out in 8 healthy subjects. At random order soluble insulin was given intravenously either at a constant rate of 0.45mU/kg · min or in identical amounts in pulses of 1 1 / 2 to 2 1 / 4 min followed by intervals of 10 1 / 2 to 9 3 / 4 min. Average serum insulin levels were similar during the two infusion protocols, but pulsatile administration induced oscillations ranging between 15 and 62 μU/ml. Glucose uptake expressed as metabolic clearance rate (MCR) for glucose was significantly increased during pulsatile insulin delivery as compared with continuous administration (270-294 min: 8.7±0.7 vs 6.8±0.9 ml/kg · min, P 3 H]glucose infusion technique was suppressed to insignificant values. Finally, the effect of insulin on endogenous insulin secretion and lipolysis as assessed by changes in serum C-peptide and serum FFA was uninfluenced by the infusion mode. In conclusion, insulin infusion resulting in physiological serum insulin levels enhances glucose uptake in peripheral tissues in healthy subjects to a higher degree when given in a pulsed pattern mimicking that of the normal endocrine pancreas than when given as a continuous infusion. (author)

Reference Curve for the Mean Uterine Artery Pulsatility Index in Singleton Pregnancies.

Science.gov (United States)

Weichert, Alexander; Hagen, Andreas; Tchirikov, Michael; Fuchs, Ilka B; Henrich, Wolfgang; Entezami, Michael

2017-05-01

Doppler sonography of the uterine artery (UA) is done to monitor pregnancies, because the detected flow patterns are useful to draw inferences about possible disorders of trophoblast invasion. Increased resistance in the UA is associated with an increased risk of preeclampsia and/or intrauterine growth restriction (IUGR) and perinatal mortality. In the absence of standardized figures, the normal ranges of the various available reference curves sometimes differ quite substantially from one another. The causes for this are differences in the flow patterns of the UA depending on the position of the pulsed Doppler gates as well as branching of the UA. Because of the discrepancies between the different reference curves and the practical problems this poses for guideline recommendations, we thought it would be useful to create our own reference curves for Doppler measurements of the UA obtained from a singleton cohort under standardized conditions. This retrospective cohort study was carried out in the Department of Obstetrics of the Charité - Universitätsmedizin Berlin, the Department for Obstetrics and Prenatal Medicine of the University Hospital Halle (Saale) and the Center for Prenatal Diagnostics and Human Genetics Kurfürstendamm 199. Available datasets from the three study locations were identified and reference curves were generated using the LMS method. Measured values were correlated with age of gestation, and a cubic model and Box-Cox power transformation (L), the median (M) and the coefficient of variation (S) were used to smooth the curves. 103 720 Doppler examinations of the UA carried out in singleton pregnancies from the 11th week of gestation (10 + 1 GW) were analyzed. The mean pulsatility index (Mean PI) showed a continuous decline over the course of pregnancy, dropping to a plateau of around 0.84 between the 23rd and 27th GW, after which it decreased again. Age of gestation, placental position, position of pulsed Doppler gates and branching of

The pituitary-gonadal axis in healthy female dogs and bitches with gynecological disorders

NARCIS (Netherlands)

Buijtels, J.J.C.W.M.

2011-01-01

The pituitary gland produces and secretes follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in a pulsatile fashion, induced by pulses of gonadotropin-releasing hormone (GnRH) from the hypothalamus. Different cells in the ovary are capable of secreting estradiol, testosterone and

Aneurysm pulsatility after endovascular exclusion: an experimental study using human aortic aneurysms

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Hussein Amin Orra

2008-01-01

Full Text Available OBJECTIVE: To measure the pulsatility of human aneurysms before and after complete exclusion with an endograft. METHOD: Five aortic aneurysms obtained during necropsy were submitted to pulsatile perfusion before and after implantation of a bifurcated endograft. The specimens were contained in a closed chamber filled with saline solution. A vertical tube attached to the chamber was used to measure volume dislocation in each systole. Mural thrombus was kept intact, and the space around the device was filled with human blood. After each experiment, the aneurysm was opened to check for the correct positioning and attachment of the device. RESULTS: The level of the saline column oscillated during pulsation in each case, with respective amplitudes of 17, 16, 13, 7, and 25 cm before the endograft insertion. After the insertion, the amplitudes dropped to 13, 12, 9, 3.5, and 23 cm, respectively. The differences were not significant. During the post-experimental examination, all devices were found to be in position and well attached to the neck and iliacs. No endoleak was detected during perfusion or by visual inspection. CONCLUSION: Pulsation of an endograft is transmitted to the aneurysm wall even in the absence of endoleak, and should not be interpreted as procedural failure.

Anti-inflammatory effect with high intensity focused ultrasound-mediated pulsatile delivery of diclofenac.

Science.gov (United States)

Wang, Chih-Yu; Yang, Chih-Hui; Lin, Yung-Sheng; Chen, Chih-Hsin; Huang, Keng-Shiang

2012-02-01

A pulsatile ultrasound controlled drug release platform with diclofenac-loaded alginate microcapsules (fabricated with a home-made electrostatic device, 75% embedded rate) was established to evaluate anti-inflammation efficiency. Better anti-inflammation efficiency was found using the ultrasound system and the drug delivery can be adjusted based on the programmed ultrasound cycle. The results of the in vitro study show that an approx. 30% higher drug release rate was obtained by using continuous ultrasound irradiation (9-Watt, 180 min), and an approx. 16% higher drug release rate was obtained by using pulsatile ultrasound irradiation (9-Watt, 60 min) compared to without ultrasound activation. For the in vivo study, the anti-inflammatory test with carrageenan-induced rat's paw edema shows that diclofenac-loaded microcapsules followed by ultrasound irradiation (9-Watt, 60 min) contributed to an 81% inhibition rate, which was significantly higher than diclofenac only (approx. 60% higher). In addition, because of their heat conducting properties, gold nanoparticles encapsulated in the diclofenac-loaded microcapsules resulted in better drug release efficiency, but tended to depress the anti-inflammation effect. Copyright © 2011 Elsevier Ltd. All rights reserved.

Establishment of detailed reference values for luteinizing hormone, follicle stimulating hormone, estradiol, and progesterone during different phases of the menstrual cycle on the Abbott ARCHITECT® analyzer

OpenAIRE

Stricker, Reto; Eberhart, Raphael; Chevailler, Marie-Christine; Quinn, Frank A.; Bischof, Paul; Stricker, René

2017-01-01

During a normal menstrual cycle, serum levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH), estradiol, and progesterone can vary widely between cycles for the same woman, as well as between different woman. Reliable reference values based on the local population are important for correct interpretation of laboratory results. The purpose of our study was to determine detailed reference values for these hormones throughout the menstrual cycle using the Abbott ARCHITECT system...

Discrepancies between Antimullerian Hormone and Follicle Stimulating Hormone in Assisted Reproduction

Directory of Open Access Journals (Sweden)

Munawar Hussain

2013-01-01

Full Text Available Data from 107 women undergoing their first IVF/ICSI were analyzed. Relationships between antimullerian hormone (AMH and follicle stimulating hormone (FSH were analyzed after dividing patients into four groups according to AMH/FSH levels. Concordance was noted in 57% of women (both AMH/FSH either normal or abnormal while 43%of women had discordant values (AMH/FSH one hormone normal and the other abnormal. Group 1 (AMH and FSH in normal range and group 2 (normal AMH and high FSH were younger compared to group 3 (low AMH and normal FSH and group 4 (both AMH/FSH abnormal. Group 1 showing the best oocyte yield was compared to the remaining three groups. Groups 3 and 4 required higher dose of gonadotrophins for controlled ovarian hyperstimulation showing their low ovarian reserve. There was no difference in cycle cancellation, clinical pregnancy, and live birth/ongoing pregnancy rate in all groups. These tests are useful to predict ovarian response but whether AMH is a substantially better predictor is not yet established.

Ocular Perfusion Pressure and Pulsatile Ocular Blood Flow in Normal and Systemic Hypertensive Patients.

Science.gov (United States)

Kanadani, Fabio N; Figueiredo, Carlos R; Miranda, Rafaela Morais; Cunha, Patricia Lt; M Kanadani, Tereza Cristina; Dorairaj, Syril

2015-01-01

Glaucomatous neuropathy can be a consequence of insufficient blood supply, increase in intraocular pressure (IOP), or other risk factors that diminish the ocular blood flow. To determine the ocular perfusion pressure (OPP) in normal and systemic hypertensive patients. One hundred and twenty-one patients were enrolled in this prospective and comparative study and underwent a complete ophthalmologic examination including slit lamp examination, Goldmann applanation tonometry, stereoscopic fundus examination, and pulsatile ocular blood flow (POBF) measurements. The OPP was calculated as being the medium systemic arterial pressure (MAP) less the IOP. Only right eye values were considered for calculations using Student's t-test. The mean age of the patients was 57.5 years (36-78), and 68.5% were women. There was a statistically significant difference in the OPP of the normal and systemic hypertensive patients (p cite this article: Kanadani FN, Figueiredo CR, Miranda RM, Cunha PLT, Kanadani TCM, Dorairaj S. Ocular Perfusion Pressure and Pulsatile Ocular Blood Flow in Normal and Systemic Hypertensive Patients. J Curr Glaucoma Pract 2015;9(1):16-19.

EIT based pulsatile impedance monitoring during spontaneous breathing in cystic fibrosis.

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Krueger-Ziolek, Sabine; Schullcke, Benjamin; Gong, Bo; Müller-Lisse, Ullrich; Moeller, Knut

2017-06-01

Evaluating the lung function in patients with obstructive lung disease by electrical impedance tomography (EIT) usually requires breathing maneuvers containing deep inspirations and forced expirations. Since these maneuvers strongly depend on the patient's co-operation and health status, normal tidal breathing was investigated in an attempt to develop continuous maneuver-free measurements. Ventilation related and pulsatile impedance changes were systematically analyzed during normal tidal breathing in 12 cystic fibrosis (CF) patients and 12 lung-healthy controls (HL). Tidal breaths were subdivided into three inspiratory (In1, In2, In3) and three expiratory (Ex1, Ex2, Ex3) sections of the same amplitude of global impedance change. Maximal changes of the ventilation and the pulsatile impedance signal occurring during these sections were determined (▵I V and ▵I P ). Differences in ▵I V and ▵I P among sections were ascertained in relation to the first inspiratory section. In addition, ▵I V /▵I P was calculated for each section. Medians of changes in ▵I V were  <0.05% in all sections for both subject groups. Both groups showed a similar pattern of ▵I P changes during tidal breathing. Changes in ▵I P first decreased during inspiration (In2), then increased towards the end of inspiration (In3) and reached a maximum at the beginning of expiration (Ex1). During the last two sections of expiration (Ex2, Ex3) ▵I P changes decreased. The CF patients showed higher variations in ▵I P changes compared to the controls (CF:  -426.5%, HL:  -158.1%, coefficient of variation). Furthermore, ▵I V /▵I P significantly differed between expiratory sections for the CF patients (Ex1-Ex2, p  <  0.01; Ex1-Ex3, p  <  0.001; Ex2-Ex3, p  <  0.05), but not for the controls. No significant differences in ▵I V /▵I P between inspiratory sections were determined for both groups. Differences in ▵I P changes and in ▵I V /▵I P between

Mathematical Modelling of CSF Pulsatile Flow in Aqueduct Cerebri.

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Czosnyka, Zofia; Kim, Dong-Joo; Balédent, Olivier; Schmidt, Eric A; Smielewski, Peter; Czosnyka, Marek

2018-01-01

The phase-contrast MRI technique permits the non-invasive assessment of CSF movements in cerebrospinal fluid cavities of the central nervous system. Of particular interest is pulsatile cerebrospinal fluid (CSF) flow through the aqueduct cerebri. It is allegedly increased in hydrocephalus, having potential diagnostic value, although not all scientific reports contain unequivocally positive conclusions. For the mathematical simulation of CSF flow, we used a computational model of cerebrospinal blood/fluid circulation designed by a former student as his PhD project. With this model, cerebral blood flow and CSF may be simulated in various vessels using a system of non-linear differential equations as time-varying signals. The amplitude of CSF flow seems to be positively related to the amplitude of pulse waveforms of intracranial pressure (ICP) in situations where mean ICP increases, such as during simulated infusion tests and following step increases of resistance to CSF outflow. An additional positive association between the pulse amplitude of ICP and CSF flow can be seen during simulated increases in the amplitude of arterial pulses (without changes in mean arterial pressure, MAP). The opposite effect can be observed during step increases in the resistance of the aqueduct cerebri and with decreasing elasticity of the system, where the CSF flow amplitude and the ICP pulse amplitude are related inversely. Vasodilatation caused by both gradual decreases in MAP and by increases in PaCO2 provokes an elevation in the observed amplitude of pulsatile CSF flow. Preliminary results indicate that the pulsations of CSF flow may carry information about both CSF-circulatory and cerebral vasogenic components. In most cases, the pulsations of CSF flow are positively related to the pulse amplitudes of both arterial pressure and ICP and to a degree of cerebrovascular dilatation.

Electroresponsive polymer-carbon nanotube hydrogel hybrids for pulsatile drug delivery in vivo.

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Servant, Ania; Methven, Laura; Williams, Rhodri P; Kostarelos, Kostas

2013-06-01

Drug release triggered by an external non-invasive stimulus is of great interest for the development of new drug delivery systems. The preparation of an electroresponsive multiwalled carbon nanotube/poly(methylacrylic acid) (MWNT/PMAA)-based hybrid material is reported. The hydrogel hybrids achieve a controlled drug release upon the ON/OFF application of an electric field, giving rise to in vitro and in vivo pulsatile release profiles. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Radioimmunoassay of bovine, ovine and porcine luteinizing hormone with a monoclonal antibody and a human tracer

Energy Technology Data Exchange (ETDEWEB)

Fosberg, M; Tagle, R; Madej, A; Molina, J R; Carlsson, M -A

1993-01-01

A radioimmunoassay for bovine (bLH), ovine (oLH) and porcine (pLH) luteinizing hormone was developed using a human [sup 125]ILH tracer from a commercial kit and a monoclonal antibody (518B7) specific for LH but with low species specificity. Standard curves demonstrated similar binding kinetics when bLH, oLH and pLH were incubated with tracer and antibody for 2 h at room temperature. A 30-min delay in the addition of the tracer gave sufficient sensitivity when analysing pLH. Separation of antibody-bound LH from free hormone was achieved by using second antibody-coated micro Sepharose beads. The assay was validated and the performance compared with that of an RIA currently in use for determination of bLH (coefficient of correlation: 0.99 and 0.98). Regardless of the standards used, intra-assay coefficients of variation were <10% for LH concentrations exceeding 1 [mu]g/L. The inter-assay coefficients of variation were <15%. The assay was used for clinical evaluation demonstrating the pre-ovulatory LH surge in two cyclic cows, LH pulsatility in an oophorectomized ewe and LH response to GnRH injection in a boar. (au) (7 refs.).

Arduino control of a pulsatile flow rig.

Science.gov (United States)

Drost, S; de Kruif, B J; Newport, D

2018-01-01

This note describes the design and testing of a programmable pulsatile flow pump using an Arduino micro-controller. The goal of this work is to build a compact and affordable system that can relatively easily be programmed to generate physiological waveforms. The system described here was designed to be used in an in-vitro set-up for vascular access hemodynamics research, and hence incorporates a gear pump that delivers a mean flow of 900 ml/min in a test flow loop, and a peak flow of 1106 ml/min. After a number of simple identification experiments to assess the dynamic behaviour of the system, a feed-forward control routine was implemented. The resulting system was shown to be able to produce the targeted representative waveform with less than 3.6% error. Finally, we outline how to further increase the accuracy of the system, and how to adapt it to specific user needs. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

Functional hypothalamic amenorrhea: current view on neuroendocrine aberrations.

Science.gov (United States)

Meczekalski, Blazej; Podfigurna-Stopa, Agnieszka; Warenik-Szymankiewicz, Alina; Genazzani, Andrea Riccardo

2008-01-01

Functional hypothalamic amenorrhea (FHA) is defined as a non-organic and reversible disorder in which the impairment of gonadotropin-releasing hormone (GnRH) pulsatile secretion plays a key role. There are main three types of FHA: stress-related amenorrhea, weight loss-related amenorrhea and exercise-related amenorrhea. The spectrum of GnRH-luteinizing hormone (LH) disturbances in FHA is very broad and includes lower mean frequency of LH pulses, complete absence of LH pulsatility, normal-appearing secretion pattern and higher mean frequency of LH pulses. Precise mechanisms underlying the pathophysiology of FHA are very complex and unclear. Numerous neuropeptides, neurotransmitters and neurosteroids play important roles in the physiological regulation of GnRH pulsatile secretion and there is evidence that different neuropeptides may be involved in the pathophysiology of FHA. Particular attention is paid to such substances as allopregnanolone, neuropeptide Y, corticotropin-releasing hormone, leptin, ghrelin and beta-endorphin. Some studies reveal significant changes in these mentioned substances in patients with FHA. There are also speculations about use some of these substances or their antagonists in the treatment of FHA.

Computational fluid dynamics analysis and PIV validation of a bionic vortex flow pulsatile LVAD.

Science.gov (United States)

Xu, Liang; Yang, Ming; Ye, Lin; Dong, Zhaopeng

2015-01-01

Hemocompatibility is highly affected by the flow field in Left Ventricular Assistant Devices (LVAD). An asymmetric inflow and outflow channel arrangement with a 45° intersection angle with respect to the blood chamber is proposed to approximate the vascular structure of the aorta and left atrium on the left ventricle. The structure is expected to develop uninterruptible vortex flow state which is similar to the flow state in human left ventricle. The Computational Fluid Dynamics (CFD) asymmetric model is simulated using ANSYS workbench. To validate the velocity field calculated by CFD, a Particle Image Velocimetry (PIV) experiment is conducted. The CFD results show that the proposed blood chamber could generate a shifting vortex flow that would be redirected to the aorta during ejection to form a persistent recirculating flow state, which is similar to the echocardiographic flow state in left ventricle. Both the PIV and the CFD results show the development of a persistent vortex during the pulsatile period. Comparison of the qualitative flow pattern and quantitative probed velocity histories in a pulsatile period shows a good agreement between the CFD and PIV data. The goal of developing persistent quasi intra-ventricle vortex flow state in LVAD is realized.

Concomitant inhibition of pulsatile luteinizing hormone (LH) and stimulation of prolactin release by prostacyclin (PGI2) in ovariectomized (OVX) conscious rats

International Nuclear Information System (INIS)

Ottlecz, A.; McCann, S.M.

1988-01-01

Prostacyclin (PGI 2 ) or its stable metabolite, 6-keto-PGF/sub 1 alpha/ in 2.5 μl 0.05 M phosphate buffer, was injected into the third ventricle (3 V) of ovariectomized (OVX), freely moving rats. Control animals received 2.5 μl of buffer. In the initial experiments a control blood sample was taken and then the PGI 2 was injected and frequent samples taken thereafter. With this protocol injection of 2 μg of PGI 2 produced a significant decrease in mean plasma LH only at 60 min after its injection, while the higher dose decreased plasma LH concentration at 30 and 60 min. In subsequent experiments, blood was removed from indwelling external jugular vein cannulae every 5-6 min during 2 hours and plasma LH and PRL levels were determined by radioimmunoassay. LH pulses were monitored and several parameters of LH pulsation were calculated during the hour before and after injection of phosphate buffer, PGI 2 or 6-keto-PGF/sub 1a/. Intraventricular injection of phosphate buffer failed to modify the characteristic pulsatile release of LH and did not alter plasma PRL levels. The amplitude of LH pulses was significantly reduced by PGI 2 and the inhibitory effect was dose-related. Even a dose of 1 μg produced a significant reduction in pulse height and the response was graded with maximal reduction occurring with the 5 μg dose which essentially abolished the LH pulses

A Novel Pulsatile Bioreactor for Mechanical Stimulation of Tissue Engineered Cardiac Constructs

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Günther Eissner

2011-07-01

Full Text Available After myocardial infarction, the implantation of stem cell seeded scaffolds on the ischemic zone represents a promising strategy for restoration of heart function. However, mechanical integrity and functionality of tissue engineered constructs need to be determined prior to implantation. Therefore, in this study a novel pulsatile bioreactor mimicking the myocardial contraction was developed to analyze the behavior of mesenchymal stem cells derived from umbilical cord tissue (UCMSC colonized on titanium-coated polytetrafluorethylene scaffolds to friction stress. The design of the bioreactor enables a simple handling and defined mechanical forces on three seeded scaffolds at physiological conditions. The compact system made of acrylic glass, Teflon®, silicone, and stainless steel allows the comparison of different media, cells and scaffolds. The bioreactor can be gas sterilized and actuated in a standard incubator. Macroscopic observations and pressure-measurements showed a uniformly sinusoidal pulsation, indicating that the bioreactor performed well. Preliminary experiments to determine the adherence rate and morphology of UCMSC after mechanical loadings showed an almost confluent cellular coating without damage on the cell surface. In summary, the bioreactor is an adequate tool for the mechanical stress of seeded scaffolds and offers dynamic stimuli for pre-conditioning of cardiac tissue engineered constructs in vitro.

Laser Doppler anemometer measurements of pulsatile flow in a model carotid bifurcation.

Science.gov (United States)

Ku, D N; Giddens, D P

1987-01-01

Hemodynamics at the human carotid bifurcation is important to the understanding of atherosclerotic plaque initiation and progression as well as to the diagnosis of clinically important disease. Laser Doppler anemometry was performed in a large scale model of an average human carotid. Pulsatile waveforms and physiologic flow divisions were incorporated. Disturbance levels and shear stresses were computed from ensemble averages of the velocity waveform measurements. Flow in the common carotid was laminar and symmetric. Flow patterns in the sinus, however, were complex and varied considerably during the cycle. Strong helical patterns and outer wall flow separation waxed and waned during each systole. The changing flow patterns resulted in an oscillatory shear stress at the outer wall ranging from -13 to 9 dyn cm-2 during systole with a time-averaged mean of only -0.5 dyn cm-2. This contrasts markedly with an inner wall shear stress range of 17-50, (mean 26) dyn cm-2. The region of transient separation was confined to the carotid sinus outer wall with no reverse velocities detected in the distal internal carotid. Notable disturbance velocities were also time-dependent, occurring only during the deceleration phase of systole and the beginning of diastole. The present pulsatile flow studies have aided in identifying hemodynamic conditions which correlate with early intimal thickening and predict the physiologic level of flow disturbances in the bulb of undiseased internal carotid arteries.

Hormone action. Part I. Peptide hormones

International Nuclear Information System (INIS)

Birnbaumer, L.; O'Malley, B.W.

1985-01-01

The major sections of this book on the hormonal action of peptide hormones cover receptor assays, identification of receptor proteins, methods for identification of internalized hormones and hormone receptors, preparation of hormonally responsive cells and cell hybrids, purification of membrane receptors and related techniques, assays of hormonal effects and related functions, and antibodies in hormone action

Correlation between vortices and wall shear stress in a curved artery model under pulsatile flow conditions

Science.gov (United States)

Cox, Christopher; Plesniak, Michael W.

2017-11-01

One of the most physiologically relevant factors within the cardiovascular system is the wall shear stress. The wall shear stress affects endothelial cells via mechanotransduction and atherosclerotic regions are strongly correlated with curvature and branching in the human vasculature, where the shear stress is both oscillatory and multidirectional. Also, the combined effect of curvature and pulsatility in cardiovascular flows produces unsteady vortices. In this work, our goal is to assess the correlation between multiple vortex pairs and wall shear stress. To accomplish this, we use an in-house high-order flux reconstruction Navier-Stokes solver to simulate pulsatile flow of a Newtonian blood-analog fluid through a rigid 180° curved artery model. We use a physiologically relevant flow rate and generate results using both fully developed and uniform entrance conditions, the latter motivated by the fact that flow upstream to a curved artery may not be fully developed. Under these two inflow conditions, we characterize the evolution of various vortex pairs and their subsequent effect on several wall shear stress metrics. Supported by GW Center for Biomimetics and Bioinspired Engineering.

Prediction of low birth weight: the placental T2* estimated by MRI versus the uterine artery pulsatility index

DEFF Research Database (Denmark)

Sinding, Marianne Munk; Peters, David Alberg; Frøkjær, Jens Brøndum

(MRI) variable T2* reflects the placental oxygenation and thereby placental function. Therefore, we aimed to evaluate the performance of placental T2* in the prediction of low birth weight using the uterine artery (UtA) pulsatility index (PI) as gold standard. Methods: The study population......CONTROL ID: 2516296 ABSTRACT FINAL ID: P22.05 TITLE: Prediction of low birth weight: the placental T2* estimated by MRI versus the uterine artery pulsatility index AUTHORS (FIRST NAME, LAST NAME): Marianne Sinding1, David Peters2, Jens B. Frøkjær3, 4, Ole B. Christiansen1, 4, Astrid Petersen5...... had an EFW T2* was measured by MRI at 1.5T. A gradient recalled echo MRI sequence with readout at 16 echo times was used, and the placental T2* value was obtained by fitting the signal intensity as a function of the echo times...

Measuring pulsatile forces on the human cranium.

Science.gov (United States)

Goldberg, Cory S; Antonyshyn, Oleh; Midha, Rajiv; Fialkov, Jeffrey A

2005-01-01

The cyclic stresses in the cranium caused by pulsation of the brain play an important role in the design of materials for cranioplasty, as well as craniofacial development. However, these stresses have never been quantified. In this study, the force in the epidural space against the cranium was measured intraoperatively in 10 patients using a miniature force probe. Heart and ventilatory rates computed from the force tracing correlated closely with the corresponding measured values in the patients, confirming that the forces measured were indeed a result of brain pulsation. The mean outward systolic normal and tangential stresses were 54.2 kilo-Pascals (kPa) and 345.4 kPa, respectively. The systolic shear stress was 199.8 kPa. Through mechanotransduction, these stresses play a role in cranial development. The calculated yield stress of a cranioplasty repair was 0.4 MPa, which is within one order of magnitude of the known strength of common calcium-phosphate cements. This indicates a possible relation of these pulsatile forces and occult failure of calcium-phosphate cement cranioplasties through material fatigue.

Thyroid Hormone, Cancer, and Apoptosis.

Science.gov (United States)

Lin, Hung-Yun; Chin, Yu-Tan; Yang, Yu-Chen S H; Lai, Husan-Yu; Wang-Peng, Jacqueline; Liu, Leory F; Tang, Heng-Yuan; Davis, Paul J

2016-06-13

Thyroid hormones play important roles in regulating normal metabolism, development, and growth. They also stimulate cancer cell proliferation. Their metabolic and developmental effects and growth effects in normal tissues are mediated primarily by nuclear hormone receptors. A cell surface receptor for the hormone on integrin [alpha]vβ3 is the initiation site for effects on tumor cells. Clinical hypothyroidism may retard cancer growth, and hyperthyroidism was recently linked to the prevalence of certain cancers. Local levels of thyroid hormones are controlled through activation and deactivation of iodothyronine deiodinases in different organs. The relative activities of different deiodinases that exist in tissues or organs also affect the progression and development of specific types of cancers. In this review, the effects of thyroid hormone on signaling pathways in breast, brain, liver, thyroid, and colon cancers are discussed. The importance of nuclear thyroid hormone receptor isoforms and of the hormone receptor on the extracellular domain of integrin [alpha]vβ3 as potential cancer risk factors and therapeutic targets are addressed. We analyze the intracellular signaling pathways activated by thyroid hormones in cancer progression in hyperthyroidism or at physiological concentrations in the euthyroid state. Determining how to utilize the deaminated thyroid hormone analog (tetrac), and its nanoparticulate derivative to reduce risks of cancer progression, enhance therapeutic outcomes, and prevent cancer recurrence is also deliberated. © 2016 American Physiological Society. Compr Physiol 6:1221-1237, 2016. Copyright © 2016 John Wiley & Sons, Inc.

On heat transfer to pulsatile flow of a two-phase fluid

Directory of Open Access Journals (Sweden)

S. P. Chakraborty

2005-09-01

Full Text Available The problem of heat transfer to pulsatile flow of a two-phase fluid-particle system contained in a channel bounded by two infinitely long rigid impervious parallel walls has been studied in this paper. The solutions for the steady and the fluctuating temperature distributions are obtained. The rates of heat transfer at the walls are also calculated. The results are discussed numerically with graphical presentations. It is shown that the presence of the particles not only diminishes the steady and unsteady temperature fields but also decreases the reversal of heat flux at the hotter wall irrespective of the influences of other flow parameters.

Effects of growth hormone administration on the body composition and hormone levels of genetically fat sheep

International Nuclear Information System (INIS)

Francis, S.M.; Jopson, N.B.; Littlejohn, R.P.; Stuart, S.K.; Veenvliet, B.A.; Young, M.J.; Suttie, J.M.

1998-01-01

Coopworth sheep selected for low (lean) or high (fat) backfat have large differences in plasma GH profiles. Fat genotype ram lambs (5 months old) were treated with growth hormone (GH) to simulate the plasma GH profiles of lean sheep and investigate whether exogenous GH could modify carcass fatness. For 77 days, bovine GH was administered at 25mug/kg live weight per day either as a single, daily subcutaneous bolus (fat bolus) or via portable pulsatile infusion pumps (fat pump) which delivered GH solution at 90-min intervals into a jugular catheter. Measurements of body composition were made by computed tomography (CT) and ultrasonic scanning during the trial, with linear carcass measurements and proximate analysis undertaken at the end of the experiment. Before treatments began, mean plasma GH levels were lower (P < 0.01) in fat control (0.34 mug/l) than in lean lambs (1.1 mug/l). Several weeks after the start of the trial, mean plasma GH had increased in both fat bolus (1.2mug/l) and fat pump (0.45mug/l) treatment lambs with major changes in the pulsatility relative to the fat control lambs. Although these changes were maintained in the fat bolus lambs, by the end of the trial there was no significant difference in mean plasma GH between fat pump and fat control sheep. Throughout the trial, plasma IGF-1 levels were higher in fat bolus, fat pump and lean lambs than in fat control lambs. Analysis of body composition data over the GH treatment period revealed that the slope of the allometric equation for total fat relative to empty body weight was lower in the fat bolus lambs (1.07) than in the lean lambs (1.50) with fat control and fat pump treatment lambs intermediate (1.30 and 1.36, respectively). Subcutaneous fat was later maturing in lean lambs than in fat control and bolus treatment lambs when regressed against total fat, with the fat pump treatment lambs being intermediate. Linear carcass measurements revealed changes due to GH administration in the

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

Neuropeptides linking the control of appetite with reproductive function in domestic animals

Science.gov (United States)

The occurrence of puberty and maintenance of normal reproductive cycles are regulated by secretion of gonadotropin hormones from the pituitary gland, which is dependent upon the pulsatile release of gonadotropin-releasing hormone (GnRH) from the hypothalamus. It is well established that secretion of...

Characterization of the hormone-binding domain of the chicken c-erbA/thyroid hormone receptor protein

DEFF Research Database (Denmark)

Muñoz, A; Zenke, M; Gehring, U

1988-01-01

mutations present in the carboxy-terminal half of P75gag-v-erbA co-operate in abolishing hormone binding, and that the ligand-binding domain resides in a position analogous to that of steroid receptors. Furthermore, a point mutation that is located between the putative DNA and ligand-binding domains of P75......To identify and characterize the hormone-binding domain of the thyroid hormone receptor, we analyzed the ligand-binding capacities of proteins representing chimeras between the normal receptor and P75gag-v-erbA, the retrovirus-encoded form deficient in binding ligand. Our results show that several......gag-v-erbA and that renders it biologically inactive fails to affect hormone binding by the c-erbA protein. These results suggest that the mutation changed the ability of P75gag-v-erbA to affect transcription since it also had no effect on DNA binding. Our data also suggest that hormone...

Menstrual phase-related differences in the pulsatility index on the central retinal artery suggest an oestrogen vasodilatation effect that antagonizes with progesterone.

Science.gov (United States)

Viana, Luiz Carlos; Faria, Marcos; Pettersen, Heverton; Sampaio, Marcos; Geber, Selmo

2011-03-01

The actual effect of steroid hormones on cerebral microcirculation is still controversial. Therefore, the aim of our study was to investigate vascular flow variations in the central retinal artery that may exist during the ovulatory menstrual cycle. A total of 34 healthy women were included in this observational, longitudinal, and prospective study. All participants were submitted to dopplerfluxometric evaluation of the eyes in order to study the pulsatility index (PI) of the central retinal arteries, during four phases of the menstrual cycle: early follicular, mid follicular, periovulatory, and mid luteal phases. Subjects' ages ranged from 14 to 47 years old (mean: 29.7 ± 10.1) and PI did not differ among age groups. The PI of the central retinal artery was different among the four phases of the menstrual cycle. PI showed a significant decrease from early follicular phase (1.72) to mid follicular phase (1.57) (p = 0.037), and was similar during periovulatory phase (1.56) and significantly increased in mid luteal phase (1.70). After that it returned to the values observed in the early follicular phase. Our results suggest the existence of an oestrogen vasodilatation effect on the central retinal artery that is menstrual phase-related and antagonized by progesterone.

Pulsatile drug delivery to ileo-colonic segments by structured incorporation of disintegrants in pH-responsive polymer coatings

NARCIS (Netherlands)

Schellekens, R.C.A.; Stellaard, F.; Mitrovic, D.; Stuurman, F.E.; Kosterink, J.G.W.; Frijlink, H.W.

2008-01-01

Conventional pH-responsive coatings used for oral drug delivery to the lower parts of the gastro-intestinal tract often show a poor performance. A new system for site-specific pulsatile delivery in the ileo-colonic regions is described. The system is based on the non-percolating incorporation of

Local pulsatile contractions are an intrinsic property of the myosin 2A motor in the cortical cytoskeleton of adherent cells.

Science.gov (United States)

Baird, Michelle A; Billington, Neil; Wang, Aibing; Adelstein, Robert S; Sellers, James R; Fischer, Robert S; Waterman, Clare M

2017-01-15

The role of nonmuscle myosin 2 (NM2) pulsatile dynamics in generating contractile forces required for developmental morphogenesis has been characterized, but whether these pulsatile contractions are an intrinsic property of all actomyosin networks is not known. Here we used live-cell fluorescence imaging to show that transient, local assembly of NM2A "pulses" occurs in the cortical cytoskeleton of single adherent cells of mesenchymal, epithelial, and sarcoma origin, independent of developmental signaling cues and cell-cell or cell-ECM interactions. We show that pulses in the cortical cytoskeleton require Rho-associated kinase- or myosin light chain kinase (MLCK) activity, increases in cytosolic calcium, and NM2 ATPase activity. Surprisingly, we find that cortical cytoskeleton pulses specifically require the head domain of NM2A, as they do not occur with either NM2B or a 2B-head-2A-tail chimera. Our results thus suggest that pulsatile contractions in the cortical cytoskeleton are an intrinsic property of the NM2A motor that may mediate its role in homeostatic maintenance of tension in the cortical cytoskeleton of adherent cells. © 2017 Baird et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Visualization and quantitative analysis of the CSF pulsatile flow with cine MR phase imaging

International Nuclear Information System (INIS)

Katayama, Shinji; Itoh, Takahiko; Kinugasa, Kazushi; Asari, Shoji; Nishimoto, Akira; Tsuchida, Shohei; Ono, Atsushi; Ikezaki, Yoshikazu; Yoshitome, Eiji.

1991-01-01

The visualization and the quantitative analysis of the CSF pulsatile flow were performed on ten healthy volunteers with cine MR phase imaging, a combination of the phase-contrast technique and the cardiac-gating technique. The velocities appropriate for the visualization and the quantitative analysis of the CSF pulsatile flow were from 6.0 cm/sec to 15.0 cm/sec. The applicability of this method for the quantitative analysis was proven with a steady-flow phantom. Phase images clearly demonstrated a to-and-fro motion of the CSF flow in the anterior subarachnoid space and in the posterior subarachnoid space. The flow pattern of CSF on healthy volunteers depends on the cardiac cycle. In the anterior subarachnoid space, the cephalic CSF flow continued until a 70-msec delay after the R-wave of the ECG and then reversed to caudal. At 130-190 msec, the caudal CSF flow reached its maximum velocity; thereafter it reversed again to cephalic. The same turn appeared following the phase, but then the amplitude decreased. The cephalic peaked at 370-430 msec, while the caudal peaked at 490-550 msec. The flow pattern of the CSF flow in the posterior subarachnoid space was almost identical to that in the anterior subarachnoid space. Cine MR phase imaging is thus useful for the visualization and the quantitative analysis of the CSF pulsative flow. (author)

Functional hypothalamic amenorrhea and its influence on women’s health

OpenAIRE

Meczekalski, B.; Katulski, K.; Czyzyk, A.; Podfigurna-Stopa, A.; Maciejewska-Jeske, M.

2014-01-01

Introduction Functional hypothalamic amenorrhea (FHA) is one of the most common causes of secondary amenorrhea. There are three types of FHA: weight loss-related, stress-related, and exercise-related amenorrhea. FHA results from the aberrations in pulsatile gonadotropin-releasing hormone (GnRH) secretion, which in turn causes impairment of the gonadotropins (follicle-stimulating hormone and luteinizing hormone). The final consequences are complex hormonal changes manifested by profound hypoes...

Enhancement of arterial pressure pulsatility by controlling continuous-flow left ventricular assist device flow rate in mock circulatory system

NARCIS (Netherlands)

Bozkurt, S.; van de Vosse, F.N.; Rutten, M.C.M.

Continuous-flow left ventricular assist devices (CF-LVADs) generally operate at a constant speed, which reduces pulsatility in the arteries and may lead to complications such as functional changes in the vascular system, gastrointestinal bleeding, or both. The purpose of this study is to increase

Pulsatile delivery of a leucine supplement during long-term continuous enteral feeding enhances lean growth in term neonatal pigs

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Neonatal pigs are used as a model to study and optimize the clinical treatment of infants who are unable to maintain oral feeding. Using this model, we have previously shown that pulsatile administration of leucine during continuous feeding over 24 h via orogastric tube enhanced protein synthesis in...

DynPeak: An Algorithm for Pulse Detection and Frequency Analysis in Hormonal Time Series

Science.gov (United States)

Vidal, Alexandre; Zhang, Qinghua; Médigue, Claire; Fabre, Stéphane; Clément, Frédérique

2012-01-01

The endocrine control of the reproductive function is often studied from the analysis of luteinizing hormone (LH) pulsatile secretion by the pituitary gland. Whereas measurements in the cavernous sinus cumulate anatomical and technical difficulties, LH levels can be easily assessed from jugular blood. However, plasma levels result from a convolution process due to clearance effects when LH enters the general circulation. Simultaneous measurements comparing LH levels in the cavernous sinus and jugular blood have revealed clear differences in the pulse shape, the amplitude and the baseline. Besides, experimental sampling occurs at a relatively low frequency (typically every 10 min) with respect to LH highest frequency release (one pulse per hour) and the resulting LH measurements are noised by both experimental and assay errors. As a result, the pattern of plasma LH may be not so clearly pulsatile. Yet, reliable information on the InterPulse Intervals (IPI) is a prerequisite to study precisely the steroid feedback exerted on the pituitary level. Hence, there is a real need for robust IPI detection algorithms. In this article, we present an algorithm for the monitoring of LH pulse frequency, basing ourselves both on the available endocrinological knowledge on LH pulse (shape and duration with respect to the frequency regime) and synthetic LH data generated by a simple model. We make use of synthetic data to make clear some basic notions underlying our algorithmic choices. We focus on explaining how the process of sampling affects drastically the original pattern of secretion, and especially the amplitude of the detectable pulses. We then describe the algorithm in details and perform it on different sets of both synthetic and experimental LH time series. We further comment on how to diagnose possible outliers from the series of IPIs which is the main output of the algorithm. PMID:22802933

A pulsatile flow model for in vitro quantitative evaluation of prosthetic valve regurgitation

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S. Giuliatti

2000-03-01

Full Text Available A pulsatile pressure-flow model was developed for in vitro quantitative color Doppler flow mapping studies of valvular regurgitation. The flow through the system was generated by a piston which was driven by stepper motors controlled by a computer. The piston was connected to acrylic chambers designed to simulate "ventricular" and "atrial" heart chambers. Inside the "ventricular" chamber, a prosthetic heart valve was placed at the inflow connection with the "atrial" chamber while another prosthetic valve was positioned at the outflow connection with flexible tubes, elastic balloons and a reservoir arranged to mimic the peripheral circulation. The flow model was filled with a 0.25% corn starch/water suspension to improve Doppler imaging. A continuous flow pump transferred the liquid from the peripheral reservoir to another one connected to the "atrial" chamber. The dimensions of the flow model were designed to permit adequate imaging by Doppler echocardiography. Acoustic windows allowed placement of transducers distal and perpendicular to the valves, so that the ultrasound beam could be positioned parallel to the valvular flow. Strain-gauge and electromagnetic transducers were used for measurements of pressure and flow in different segments of the system. The flow model was also designed to fit different sizes and types of prosthetic valves. This pulsatile flow model was able to generate pressure and flow in the physiological human range, with independent adjustment of pulse duration and rate as well as of stroke volume. This model mimics flow profiles observed in patients with regurgitant prosthetic valves.

Chronotherapeutically Modulated Pulsatile System of Valsartan Nanocrystals-an In Vitro and In Vivo Evaluation.

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Biswas, Nikhil; Kuotsu, Ketousetuo

2017-02-01

The objective was to improve the dissolution of valsartan by developing valsartan nanocrystals and design a pulsed release system for the chronotherapy of hypertension. Valsartan nanocrystals were prepared by sonication-anti-solvent precipitation method and lyophilized to obtain dry powder. Nanocrystals were directly compressed to minitablets and coated to achieve pulsatile valsartan release. Pharmacokinetic profiles of optimized and commercial formulations were compared in rabbit model. The mean particle size and PDI of the optimized nanocrystal batch V4 was reported as 211 nm and 0.117, respectively. DSC and PXRD analysis confirmed the crystalline nature of valsartan in nanocrystals. The dissolution extent of valsartan was markedly enhanced with both nanocrystals and minitablets as compared to pure valsartan irrespective of pH of the medium. Core minitablet V4F containing 5% w/w polyplasdone XL showed quickest release of valsartan, over 90% within 15 min. Coated formulation CV4F showed two spikes in release profile after successive lag times of 235 and 390 min. The pharmacokinetic study revealed that the bioavailability of optimized formulation (72.90%) was significantly higher than the commercial Diovan tablet (30.18%). The accelerated stability studies showed no significant changes in physicochemical properties, release behavior, and bioavialability of CV4F formulation. The formulation was successfully designed to achieve enhanced bioavailability and dual pulsatile release. Bedtime dosing will more efficiently control the circadian spikes of hypertension in the morning.

Pulsatility of Lenticulostriate Arteries Assessed by 7 Tesla Flow MRI-Measurement, Reproducibility, and Applicability to Aging Effect.

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Schnerr, Roald S; Jansen, Jacobus F A; Uludag, Kamil; Hofman, Paul A M; Wildberger, Joachim E; van Oostenbrugge, Robert J; Backes, Walter H

2017-01-01

Characterization of flow properties in cerebral arteries with 1.5 and 3 Tesla MRI is usually limited to large cerebral arteries and difficult to evaluate in the small perforating arteries due to insufficient spatial resolution. In this study, we assessed the feasibility to measure blood flow waveforms in the small lenticulostriate arteries with 7 Tesla velocity-sensitive MRI. The middle cerebral artery was included as reference. Imaging was performed in five young and five old healthy volunteers. Flow was calculated by integrating time-varying velocity values over the vascular cross-section. MRI acquisitions were performed twice in each subject to determine reproducibility. From the flow waveforms, the pulsatility index and damping factor were deduced. Reproducibility values, in terms of the intraclass correlation coefficients, were found to be good to excellent. Measured pulsatility index of the lenticulostriate arteries significantly increased and damping factor significantly decreased with age. In conclusion, we demonstrate that blood flow through the lenticostriate arteries can be precisely measured using 7 Tesla MRI and reveal effects of arterial stiffness due to aging. These findings hold promise to provide relevant insights into the pathologies involving perforating cerebral arteries.

Measurement of pulsatile motion with millisecond resolution by MRI.

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Souchon, Rémi; Gennisson, Jean-Luc; Tanter, Mickael; Salomir, Rares; Chapelon, Jean-Yves; Rouvière, Olivier

2012-06-01

We investigated a technique based on phase-contrast cine MRI combined with deconvolution of the phase shift waveforms to measure rapidly varying pulsatile motion waveforms. The technique does not require steady-state displacement during motion encoding. Simulations and experiments were performed in porcine liver samples in view of a specific application, namely the observation of transient displacements induced by acoustic radiation force. Simulations illustrate the advantages and shortcomings of the methods. For experimental validation, the waveforms were acquired with an ultrafast ultrasound scanner (Supersonic Imagine Aixplorer), and the rates of decay of the waveforms (relaxation time) were compared. With bipolar motion-encoding gradient of 8.4 ms, the method was able to measure displacement waveforms with a temporal resolution of 1 ms over a time course of 40 ms. Reasonable agreement was found between the rate of decay of the waveforms measured in ultrasound (2.8 ms) and in MRI (2.7-3.3 ms). Copyright © 2011 Wiley-Liss, Inc.

Effects of experimentally induced mild hyperthyroidism on growth hormone and insulin secretion and sex steroid levels in healthy young men.

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Lovejoy, J C; Smith, S R; Bray, G A; Veldhuis, J D; Rood, J C; Tulley, R

1997-12-01

Although triiodothyronine (T3) exerts major regulatory actions in both animals and humans, most clinical studies of T3 administration have been relatively short-term. The present study examined the effects of more than 2 months (63 days) of low-dose T3 treatment on overnight pulsatile growth hormone (GH) secretion, short-term insulin secretion, and of sex steroid levels in seven healthy, lean men studied at an inpatient metabolic unit. At baseline, there were strong correlations between sex hormone-binding globulin (SHBG) and several measures of GH production, including total GH production (r = .99), GH interburst interval (r = -.75), and GH mass (r = .82). SHBG was also inversely correlated with basal insulin secretion (r = -.74). There was a 42% increase in serum levels of total testosterone (18.5 +/- 1.3 to 26.3 +/- 1.8 nmol/L, P = .005) and a 150% increase in SHBG (18.0 +/- 2.2 to 44.9 +/- 7.0 nmol/L, P = .008) following T3 treatment. Estradiol and free testosterone levels were unchanged by treatment, although free testosterone decreased from 142.8 +/- 18.4 to 137.3 +/- 19.5 pmol/L. T3 treatment significantly reduced the GH interburst interval (P secretion. There were no statistically significant effects of T3 treatment on insulin secretion, although insulin peak amplitude, mass secreted per burst, and total production all decreased. We conclude that experimentally induced T3 excess in healthy men produces significant and sustained changes in sex hormone levels and GH secretion. Furthermore, there are strong associations between SHBG and both GH and insulin secretion independent of thyroid hormone excess that require additional study.

Pulsatile flow of blood and heat transfer with variable viscosity under magnetic and vibration environment

International Nuclear Information System (INIS)

Shit, G.C.; Majee, Sreeparna

2015-01-01

Unsteady flow of blood and heat transfer characteristics in the neighborhood of an overlapping constricted artery have been investigated in the presence of magnetic field and whole body vibration. The laminar flow of blood is taken to be incompressible and Newtonian fluid with variable viscosity depending upon temperature with an aim to provide resemblance to the real situation in the physiological system. The unsteady flow mechanism in the constricted artery is subjected to a pulsatile pressure gradient arising from systematic functioning of the heart and from the periodic body acceleration. The numerical computation has been performed using finite difference method by developing Crank–Nicolson scheme. The results show that the volumetric flow rate, skin-friction and the rate of heat transfer at the wall are significantly altered in the downstream of the constricted region. The axial velocity profile, temperature and flow rate increases with increase in temperature dependent viscosity, while the opposite trend is observed in the case of skin-friction and flow impedance. - Highlights: • We have investigated the pulsatile MHD flow of blood and heat transfer in arteries. • The influence of periodic body acceleration has been taken into account. • The temperature dependent viscosity of blood is considered. • The variable viscosity has an increasing effect on blood flow and heat transfer. • The overall temperature distribution enhances in the presence of magnetic field

Pulsatile flow of blood and heat transfer with variable viscosity under magnetic and vibration environment

Energy Technology Data Exchange (ETDEWEB)

Shit, G.C., E-mail: gopal_iitkgp@yahoo.co.in; Majee, Sreeparna

2015-08-15

Unsteady flow of blood and heat transfer characteristics in the neighborhood of an overlapping constricted artery have been investigated in the presence of magnetic field and whole body vibration. The laminar flow of blood is taken to be incompressible and Newtonian fluid with variable viscosity depending upon temperature with an aim to provide resemblance to the real situation in the physiological system. The unsteady flow mechanism in the constricted artery is subjected to a pulsatile pressure gradient arising from systematic functioning of the heart and from the periodic body acceleration. The numerical computation has been performed using finite difference method by developing Crank–Nicolson scheme. The results show that the volumetric flow rate, skin-friction and the rate of heat transfer at the wall are significantly altered in the downstream of the constricted region. The axial velocity profile, temperature and flow rate increases with increase in temperature dependent viscosity, while the opposite trend is observed in the case of skin-friction and flow impedance. - Highlights: • We have investigated the pulsatile MHD flow of blood and heat transfer in arteries. • The influence of periodic body acceleration has been taken into account. • The temperature dependent viscosity of blood is considered. • The variable viscosity has an increasing effect on blood flow and heat transfer. • The overall temperature distribution enhances in the presence of magnetic field.

The induction of ovulation by pulsatile administration of GnRH: an appropriate method in hypothalamic amenorrhea.

Science.gov (United States)

Christou, Fotini; Pitteloud, Nelly; Gomez, Fulgencio

2017-08-01

The induction of ovulation by the means of a pump which assures the pulsatile administration of GnRH is a well-known method that applies to women suffering from amenorrhea of hypothalamic origin. Although a simple and efficient method to establish fertility, it is underused. Twelve patients suffering from this condition, 1 Kallmann syndrome, 4 normosmic isolated hypogonadotropic hypogonadism, and 7 functional hypothalamic amenorrhea desiring pregnancy were treated. They underwent one or more cycles of pulsatile GnRH, at a frequency of 90 minutes, either by the intravenous or the subcutaneous route. An initial dose of 5 μg per pulse in the intravenous route was administered and of 15 μg per pulse in the subcutaneous route. The treatment was monitored by regular dosing of gonadotropins, estradiol and progesterone, and the development of follicles and ovulation was monitored by intra-vaginal ultrasonography. All the patients had documented ovulation, after a mean of 17 days on pump stimulation. Single ovulation occurred in 30 of 33 treatment cycles, irrespective of the route of administration. Ovulation resulted in 10 pregnancies over 7 patients (2 pregnancies in 3 of them), distributed in the 3 diagnostic categories. For comparison, a patient with PCOS treated similarly, disclosed premature LH surge without ovulation.

Effects of Thyroid Dysfunction on Reproductive Hormones in Female Rats.

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Liu, Juan; Guo, Meng; Hu, Xusong; Weng, Xuechun; Tian, Ye; Xu, Kaili; Heng, Dai; Liu, Wenbo; Ding, Yu; Yang, Yanzhou; Zhang, Cheng

2018-05-10

Thyroid hormones (THs) play a critical role in the development of ovarian cells. Although the effects of THs on female reproduction are of great interest, the mechanism remains unclear. We investigated the effects of TH dysregulation on reproductive hormones in rats. Propylthiouracil (PTU) and L-thyroxine were administered to rats to induce hypo- and hyper-thyroidism, respectively, and the reproductive hormone profiles were analyzed by radioimmunoassay. Ovarian histology was evaluated with H&E staining, and gene protein level or mRNA content was analyzed by western blotting or RT-PCR. The serum levels of gonadotropin releasing hormone (GnRH) and follicle stimulating hormone (FSH) in both rat models were significantly decreased on day 21, although there were no significant changes at earlier time points. There were no significant differences in luteinizing hormone (LH) or progesterone levels between the treatment and the control groups. Both PTU and L-thyroxine treatments downregulated estradiol concentrations; however, the serum testosterone level was increased only in hypothyroid rats at day 21. In addition, the expression levels of FSH receptor, cholesterol side-chain cleavage enzyme (P450scc), and steroidogenic acute regulatory protein were decreased in both rat models. Moreover, the onset of puberty was significantly delayed in the hypothyroid group. These results provide evidence that TH dysregulation alters reproductive hormone profiles, and that the initiation of the estrous cycle is postponed in hypothyroidism.

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)

The "multiple hormone deficiency" theory of aging: is human senescence caused mainly by multiple hormone deficiencies?

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Hertoghe, T

2005-12-01

reverse or even cure them. If hormone deficiencies and imbalances are the major causes of senescence, what then is the treatment? Crucial for the treatment of senescent persons is to make a correct diagnosis by making up an anamnesis of all symptoms related to hormone disturbances, conducting a thorough physical examination, and getting laboratory tests done such as serum and 24-hour urine analyses. The physician should look not only for hormone deficiencies, including the mildest ones, but also for any alterations in hormone circadian cycles, and for the presence of any factors--nutritional, dietary, behavioral, lifestyle, environmental (including illumination and indoor, outdoor, or dietary pollutants)--that cause or aggravate hormone deficiencies. After completion of the detailed diagnostic phase and obtaining and analyzing the results of the tests, treatment can start. In general, before supplying hormones, all other factors that contribute to senescence should be eliminated. After that, supplements of the missing hormones can then be administered, carefully respecting an appropriate timing of their intake, and eventually recommending measures such as lifestyle changes to restore circadian rhythmicity.

Implantable batteryless device for on-demand and pulsatile insulin administration

Science.gov (United States)

Lee, Seung Ho; Lee, Young Bin; Kim, Byung Hwi; Lee, Cheol; Cho, Young Min; Kim, Se-Na; Park, Chun Gwon; Cho, Yong-Chan; Choy, Young Bin

2017-04-01

Many implantable systems have been designed for long-term, pulsatile delivery of insulin, but the lifetime of these devices is limited by the need for battery replacement and consequent replacement surgery. Here we propose a batteryless, fully implantable insulin pump that can be actuated by a magnetic field. The pump is prepared by simple-assembly of magnets and constituent units and comprises a drug reservoir and actuator equipped with a plunger and barrel, each assembled with a magnet. The plunger moves to noninvasively infuse insulin only when a magnetic field is applied on the exterior surface of the body. Here we show that the dose is easily controlled by varying the number of magnet applications. Also, pump implantation in diabetic rats results in profiles of insulin concentration and decreased blood glucose levels similar to those observed in rats treated with conventional subcutaneous insulin injections.

Effects of sexually dimorphic growth hormone secretory patterns on arachidonic acid metabolizing enzymes in rodent heart

Energy Technology Data Exchange (ETDEWEB)

Zhang, Furong; Yu, Xuming [Department of Pharmacology, School of Basic Medical Sciences, Wuhan University, Wuhan 430071 (China); He, Chunyan [Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Wuhan University, Wuhan 430071 (China); Ouyang, Xiufang; Wu, Jinhua; Li, Jie; Zhang, Junjie; Duan, Xuejiao [Department of Pharmacology, School of Basic Medical Sciences, Wuhan University, Wuhan 430071 (China); Wan, Yu [Department of Physiology, School of Basic Medical Sciences, Wuhan University, Wuhan 430071 (China); Yue, Jiang, E-mail: yuejiang@whu.edu.cn [Department of Pharmacology, School of Basic Medical Sciences, Wuhan University, Wuhan 430071 (China)

2015-12-15

The arachidonic acid (AA) metabolizing enzymes are the potential therapeutic targets of cardiovascular diseases (CVDs). As sex differences have been shown in the risk and outcome of CVDs, we investigated the regulation of heart AA metabolizing enzymes (COXs, LOXs, and CYPs) by sex-dependent growth hormone (GH) secretory patterns. The pulsatile (masculine) GH secretion at a physiological concentration decreased CYP1A1 and CYP2J3 mRNA levels more efficiently in the H9c2 cells compared with the constant (feminine) GH secretion; however, CYP1B1 mRNA levels were higher following the pulsatile GH secretion. Sex differences in CYP1A1, CYP1B1, and CYP2J11 mRNA levels were observed in both the wild-type and GHR deficient mice. No sex differences in the mRNA levels of COXs, LOXs, or CYP2E1 were observed in the wild-type mice. The constant GH infusion induced heart CYP1A1 and CYP2J11, and decreased CYP1B1 in the male C57/B6 mice constantly infused with GH (0.4 μg/h, 7 days). The activity of rat Cyp2j3 promoter was inhibited by the STAT5B protein, but was activated by C/EBPα (CEBPA). Compared with the constant GH administration, the levels of the nuclear phosphorylated STAT5B protein and its binding to the rat Cyp2j3 promoter were higher following the pulsatile GH administration. The constant GH infusion decreased the binding of the nuclear phosphorylated STAT5B protein to the mouse Cyp2j11 promoter. The data suggest the sexually dimorphic transcription of heart AA metabolizing enzymes, which might alter the risk and outcome of CVDs. GHR-STAT5B signal transduction pathway may be involved in the sex difference in heart CYP2J levels. - Highlights: • The transcription of heart Cyp1a1, Cyp1b1 and Cyp2j genes is sexually dimorphic. • There are no sex differences in the mRNA levels of heart COXs, LOXs, or CYP2E1. • GHR-STAT5B pathway is involved in sexually dimorphic transcription of heart Cpy2j genes. • Heart CYPs-mediated metabolism pathway of arachidonic acid may be sex

Effects of sexually dimorphic growth hormone secretory patterns on arachidonic acid metabolizing enzymes in rodent heart

International Nuclear Information System (INIS)

Zhang, Furong; Yu, Xuming; He, Chunyan; Ouyang, Xiufang; Wu, Jinhua; Li, Jie; Zhang, Junjie; Duan, Xuejiao; Wan, Yu; Yue, Jiang

2015-01-01

The arachidonic acid (AA) metabolizing enzymes are the potential therapeutic targets of cardiovascular diseases (CVDs). As sex differences have been shown in the risk and outcome of CVDs, we investigated the regulation of heart AA metabolizing enzymes (COXs, LOXs, and CYPs) by sex-dependent growth hormone (GH) secretory patterns. The pulsatile (masculine) GH secretion at a physiological concentration decreased CYP1A1 and CYP2J3 mRNA levels more efficiently in the H9c2 cells compared with the constant (feminine) GH secretion; however, CYP1B1 mRNA levels were higher following the pulsatile GH secretion. Sex differences in CYP1A1, CYP1B1, and CYP2J11 mRNA levels were observed in both the wild-type and GHR deficient mice. No sex differences in the mRNA levels of COXs, LOXs, or CYP2E1 were observed in the wild-type mice. The constant GH infusion induced heart CYP1A1 and CYP2J11, and decreased CYP1B1 in the male C57/B6 mice constantly infused with GH (0.4 μg/h, 7 days). The activity of rat Cyp2j3 promoter was inhibited by the STAT5B protein, but was activated by C/EBPα (CEBPA). Compared with the constant GH administration, the levels of the nuclear phosphorylated STAT5B protein and its binding to the rat Cyp2j3 promoter were higher following the pulsatile GH administration. The constant GH infusion decreased the binding of the nuclear phosphorylated STAT5B protein to the mouse Cyp2j11 promoter. The data suggest the sexually dimorphic transcription of heart AA metabolizing enzymes, which might alter the risk and outcome of CVDs. GHR-STAT5B signal transduction pathway may be involved in the sex difference in heart CYP2J levels. - Highlights: • The transcription of heart Cyp1a1, Cyp1b1 and Cyp2j genes is sexually dimorphic. • There are no sex differences in the mRNA levels of heart COXs, LOXs, or CYP2E1. • GHR-STAT5B pathway is involved in sexually dimorphic transcription of heart Cpy2j genes. • Heart CYPs-mediated metabolism pathway of arachidonic acid may be sex

Flow Visualization of Three-Dimensionality Inside the 12 cc Penn State Pulsatile Pediatric Ventricular Assist Device

OpenAIRE

Roszelle, Breigh N.; Deutsch, Steven; Manning, Keefe B.

2010-01-01

In order to aid the ongoing concern of limited organ availability for pediatric heart transplants, Penn State has continued development of a pulsatile Pediatric Ventricular Assist Device (PVAD). Initial studies of the PVAD observed an increase in thrombus formation due to differences in flow field physics when compared to adult sized devices, which included a higher degree of three-dimensionality. This unique flow field brings into question the use of 2D planar particle image velocimetry (PIV...

Abnormal Baseline Brain Activity in Patients with Pulsatile Tinnitus: A Resting-State fMRI Study

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Lv Han

2014-01-01

Full Text Available Numerous investigations studying the brain functional activity of the tinnitus patients have indicated that neurological changes are important findings of this kind of disease. However, the pulsatile tinnitus (PT patients were excluded in previous studies because of the totally different mechanisms of the two subtype tinnitus. The aim of this study is to investigate whether altered baseline brain activity presents in patients with PT using resting-state functional magnetic resonance imaging (rs-fMRI technique. The present study used unilateral PT patients (n=42 and age-, sex-, and education-matched normal control subjects (n=42 to investigate the changes in structural and amplitude of low-frequency (ALFF of the brain. Also, we analyzed the relationships between these changes with clinical data of the PT patients. Compared with normal controls, PT patients did not show any structural changes. PT patients showed significant increased ALFF in the bilateral precuneus, and bilateral inferior frontal gyrus (IFG and decreased ALFF in multiple occipital areas. Moreover, the increased THI score and PT duration was correlated with increased ALFF in precuneus and bilateral IFG. The abnormalities of spontaneous brain activity reflected by ALFF measurements in the absence of structural changes may provide insights into the neural reorganization in PT patients.

Afferent neuronal control of type-I gonadotropin releasing hormone (GnRH neurons in the human

Directory of Open Access Journals (Sweden)

Erik eHrabovszky

2013-09-01

Full Text Available Understanding the regulation of the human menstrual cycle represents an important ultimate challenge of reproductive neuroendocrine research. However, direct translation of information from laboratory animal experiments to the human is often complicated by strikingly different and unique reproductive strategies and central regulatory mechanisms that can be present in even closely related animal species. In all mammals studied so far, type-I gonadotropin releasing hormone (GnRH synthesizing neurons form the final common output way from the hypothalamus in the neuroendocrine control of the adenohypophysis. Under various physiological and pathological conditions, hormonal and metabolic signals either regulate GnRH neurons directly or act on upstream neuronal circuitries to influence the pattern of pulsatile GnRH secretion into the hypophysial portal circulation. Neuronal afferents to GnRH cells convey important metabolic-, stress-, sex steroid-, lactational- and circadian signals to the reproductive axis, among other effects. This article gives an overview of the available neuroanatomical literature that described the afferent regulation of human GnRH neurons by peptidergic, monoaminergic and amino acidergic neuronal systems. Recent studies of human genetics provided evidence that central peptidergic signaling by kisspeptins and neurokinin B play particularly important roles in puberty onset and later, in the sex steroid-dependent feedback regulation of GnRH neurons. This review article places special emphasis on the topographic distribution, sexual dimorphism, aging-dependent neuroanatomical changes and plastic connectivity to GnRH neurons of the critically important human hypothalamic kisspeptin and neurokinin B systems.

Analysis of hormone-dependent pathology in female patients with juvenile myoclonic epilepsy

Directory of Open Access Journals (Sweden)

D. V. Anisimova

2017-01-01

Full Text Available Objective: to study the characteristics of manifestations of hormonal abnormalities in women with juvenile myoclonic epilepsy (JME and to comparatively analyze identified syndromes.Patients and methods. Hormonal disorders were analyzed in 48 reproductive-aged women with JME, who had received antiepileptic drug (AED mono- and bitherapy during one or more years.Results. 66.7% of the patients were found to have ovarian hormonal dysfunction manifesting itself as the development of polycystic ovary syndrome, hypogonadism, isolated hyperandrogenism, and hypoprogesteronemia. Clinically detected syndromes frequently appeared as menstrual irregularity in 29% of the patients. Comparative analysis of hormone-dependent syndromes showed that there were no differences in the clinical features of JME, but the earliest age at onset in isolated hyperandrogenism, and no patients with menstrual irregularity in the presence of isolated hypoprogesteronemia. The use of different AEDs had no impact on the incidence of hormonal abnormalities, which requires further investigation and its inclusion of a greater number of patients receiving various AEDs. 

Pulsatile flow of viscous and viscoelastic fluids in constricted tubes

Energy Technology Data Exchange (ETDEWEB)

Javadzadegan, A.; Esmaeili, M.; Majidi, S. [University of Tehran, Tehran (Iran, Islamic Republic of); Fakhimghanbarzadeh, B. [Sharif University of Technology, Tehran (Iran, Islamic Republic of)

2009-09-15

The unsteady flow of blood through stenosed artery, driven by an oscillatory pressure gradient, is studied. An appropriate shape of the time-dependent stenoses which are overlapped in the realm of the formation of arterial narrowing is constructed mathematically. A mathematical model is developed by treating blood as a non-Newtonian fluid characterized by the Oldroyd-B and Cross models. A numerical scheme has been used to solve the unsteady nonlinear Navier- stokes equations in cylindrical coordinate system governing flow, assuming axial symmetry under laminar flow condition so that the problem effectively becomes two-dimensional. Finite difference technique was used to investigate the effects of parameters such as pulsatility, non-Newtonian properties and the flow time on the velocity components, the rate of flow, and the wall shear stress through their graphical representations quantitatively at the end of the paper in order to validate the applicability of the present improved mathematical model under consideration

Pulsatile flow of viscous and viscoelastic fluids in constricted tubes

International Nuclear Information System (INIS)

Javadzadegan, A.; Esmaeili, M.; Majidi, S.; Fakhimghanbarzadeh, B.

2009-01-01

The unsteady flow of blood through stenosed artery, driven by an oscillatory pressure gradient, is studied. An appropriate shape of the time-dependent stenoses which are overlapped in the realm of the formation of arterial narrowing is constructed mathematically. A mathematical model is developed by treating blood as a non-Newtonian fluid characterized by the Oldroyd-B and Cross models. A numerical scheme has been used to solve the unsteady nonlinear Navier- stokes equations in cylindrical coordinate system governing flow, assuming axial symmetry under laminar flow condition so that the problem effectively becomes two-dimensional. Finite difference technique was used to investigate the effects of parameters such as pulsatility, non-Newtonian properties and the flow time on the velocity components, the rate of flow, and the wall shear stress through their graphical representations quantitatively at the end of the paper in order to validate the applicability of the present improved mathematical model under consideration

Contact-Free Screening of Atrial Fibrillation by a Smartphone Using Facial Pulsatile Photoplethysmographic Signals.

Science.gov (United States)

Yan, Bryan P; Lai, William H S; Chan, Christy K Y; Chan, Stephen Chun-Hin; Chan, Lok-Hei; Lam, Ka-Ming; Lau, Ho-Wang; Ng, Chak-Ming; Tai, Lok-Yin; Yip, Kin-Wai; To, Olivia T L; Freedman, Ben; Poh, Yukkee C; Poh, Ming-Zher

2018-04-05

We aimed to evaluate a novel method of atrial fibrillation (AF) screening using an iPhone camera to detect and analyze photoplethysmographic signals from the face without physical contact by extracting subtle beat-to-beat variations of skin color that reflect the cardiac pulsatile signal. Patients admitted to the cardiology ward of the hospital for clinical reasons were recruited. Simultaneous facial and fingertip photoplethysmographic measurements were obtained from 217 hospital inpatients (mean age, 70.3±13.9 years; 71.4% men) facing the front camera and with an index finger covering the back camera of 2 independent iPhones before a 12-lead ECG was recorded. Backdrop and background light intensity was monitored during signal acquisition. Three successive 20-second (total, 60 seconds) recordings were acquired per patient and analyzed for heart rate regularity by Cardiio Rhythm (Cardiio Inc, Cambridge, MA) smartphone application. Pulse irregularity in ≥1 photoplethysmographic readings or 3 uninterpretable photoplethysmographic readings were considered a positive AF screening result. AF was present on 12-lead ECG in 34.6% (n=75/217) patients. The Cardiio Rhythm facial photoplethysmographic application demonstrated high sensitivity (95%; 95% confidence interval, 87%-98%) and specificity (96%; 95% confidence interval, 91%-98%) in discriminating AF from sinus rhythm compared with 12-lead ECG. The positive and negative predictive values were 92% (95% confidence interval, 84%-96%) and 97% (95% confidence interval, 93%-99%), respectively. Detection of a facial photoplethysmographic signal to determine pulse irregularity attributable to AF is feasible. The Cardiio Rhythm smartphone application showed high sensitivity and specificity, with low negative likelihood ratio for AF from facial photoplethysmographic signals. The convenience of a contact-free approach is attractive for community screening and has the potential to be useful for distant AF screening. © 2018 The

Pulsatile and steady-state hemodynamics of the human patella bone by diffuse optical spectroscopy

International Nuclear Information System (INIS)

Farzam, Parisa; Zirak, Peyman; Durduran, Turgut; Binzoni, Tiziano

2013-01-01

The cardiac cycle related pulsatile behavior of the absorption and scattering coefficients of diffuse light and the corresponding alterations in hemoglobin concentrations in the human patella was studied. The pulsations in scattering is considerably smaller than absorption. The difference in amplitude of absorption coefficient pulsations for different wavelengths was translated to pulsations in oxygenated and deoxygenated hemoglobin, which leads to strong pulsations in the total hemoglobin concentration and oxygen saturation. The physiological origin of the observed signals was confirmed by applying a thigh-cuff. Moreover, we have investigated the optical and physiological properties of the patella bone and their changes in response to arterial cuff occlusion. (paper)

Pulsatile and steady-state hemodynamics of the human patella bone by diffuse optical spectroscopy.

Science.gov (United States)

Farzam, Parisa; Zirak, Peyman; Binzoni, Tiziano; Durduran, Turgut

2013-08-01

The cardiac cycle related pulsatile behavior of the absorption and scattering coefficients of diffuse light and the corresponding alterations in hemoglobin concentrations in the human patella was studied. The pulsations in scattering is considerably smaller than absorption. The difference in amplitude of absorption coefficient pulsations for different wavelengths was translated to pulsations in oxygenated and deoxygenated hemoglobin, which leads to strong pulsations in the total hemoglobin concentration and oxygen saturation. The physiological origin of the observed signals was confirmed by applying a thigh-cuff. Moreover, we have investigated the optical and physiological properties of the patella bone and their changes in response to arterial cuff occlusion.

Assessment of turbulence models for pulsatile flow inside a heart pump.

Science.gov (United States)

Al-Azawy, Mohammed G; Turan, A; Revell, A

2016-02-01

Computational fluid dynamics (CFD) is applied to study the unsteady flow inside a pulsatile pump left ventricular assist device, in order to assess the sensitivity to a range of commonly used turbulence models. Levels of strain and wall shear stress are directly relevant to the evaluation of risk from haemolysis and thrombosis, and thus understanding the sensitivity to these turbulence models is important in the assessment of uncertainty in CFD predictions. The study focuses on a positive displacement or pulsatile pump, and the CFD model includes valves and moving pusher plate. An unstructured dynamic layering method was employed to capture this cyclic motion, and valves were simulated in their fully open position to mimic the natural scenario, with in/outflow triggered at control planes away from the valves. Six turbulence models have been used, comprising three relevant to the low Reynolds number nature of this flow and three more intended to investigate different transport effects. In the first group, we consider the shear stress transport (SST) [Formula: see text] model in both its standard and transition-sensitive forms, and the 'laminar' model in which no turbulence model is used. In the second group, we compare the one equation Spalart-Almaras model, the standard two equation [Formula: see text] and the full Reynolds stress model (RSM). Following evaluation of spatial and temporal resolution requirements, results are compared with available experimental data. The model was operated at a systolic duration of 40% of the pumping cycle and a pumping rate of 86 BPM (beats per minute). Contrary to reasonable preconception, the 'transition' model, calibrated to incorporate additional physical modelling specifically for these flow conditions, was not noticeably superior to the standard form of the model. Indeed, observations of turbulent viscosity ratio reveal that the transition model initiates a premature increase of turbulence in this flow, when compared with

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

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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.

Comparison between induction effect with pulsatile and continuous oxytocin administration on outcomes of pregnancy in the pregnant women referring to Tabriz 29 Bahman hospital in 2006

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fahimeh Sehhati

2008-04-01

Full Text Available Abstract Background: Insufficient uterine activity or hypotonic uterine contraction is a common reason and the cause of abnormal labor progress that can be corrected with oxytocin. Realizing this fact that undue prolongation of labor may contribute to prenatal morbidity has resulted in using oxytocin infusion in different kinds of ineffective uterine contractions. Materials and methods: In this study, one hundred pregnant women in 29 Bahman hospital participated in a quasi-experimental research and were divided randomly into 2 groups of pulsatile induction as well as continuous induction and were compared in terms of pregnancy outcomes including progress of labor, hyperstimulation, mood of delivery, third stage duration, newborn’s Apgar score, and hyperbilirobinemia. Results: There were no significant differences between the two groups in progress of labor, hyperstimulation rate, newborn’s Apgar score, and hyperbilirobinemia (p>0.05 however, significant differences were observed in labor duration (p=0.022, mood of delivery (p=0.008, and dose of oxytocin (p<0.0005. Conclusion: According to the findings of this study, administration of oxytocin with the feedback pulsatile oxytocin system is easier and more physiologic to establish the effective uterine contraction and reduces duration of labor and cesarean section rate. Moreover, the average dose of oxytocin administered is significantly less in the pulsatile induction group.

Pulsatility Index of Blood Echogenicity of the Human Radial and Common Carotid Arteries: Relation with Age and Stroke

International Nuclear Information System (INIS)

Bok, Tae Hoon; Kong, Qi; Nam, Kweon Ho; Choi, Jay Chol; Paeng, Dong Guk

2012-01-01

In the present paper, the ultrasound blood images were measured at both the human radial artery(RA) and common carotid artery(CCA), depending on the age, and the pulsatility index of blood echogenicity(PIBE) was analyzed. In addition, the ultrasound blood images were measured at both RA and CCA of both the stroke patients and the control group, and PIBE was compared. PIBE of RA for the young group was similar with that for the old group (0.13±0.21 and 0.16±0.03). PIBE of CCA for the young group, however, was larger than that for the old group (0.70±0.21 and 0.32±0.01), and was more variable depending on the subject. Similarly, the fibrinogen concentrations of the patients (336±61 and 340±126 mg/dl) were more than that of the control group (264±38 and 43 mg/dl), for both RA and CCA. The results indicate the possibility of the ultrasonic test on the correlation between erythrocyte aggregation and stroke, and it is expected that the in-vivo EA measurement would be clinically useful.

PLATELET ADHESION TO POLYURETHANE UREA UNDER PULSATILE FLOW CONDITIONS

Science.gov (United States)

Navitsky, Michael A.; Taylor, Joshua O.; Smith, Alexander B.; Slattery, Margaret J.; Deutsch, Steven; Siedlecki, Christopher A.; Manning, Keefe B.

2014-01-01

Platelet adhesion to a polyurethane urea surface is a precursor to thrombus formation within blood-contacting cardiovascular devices, and platelets have been found to adhere strongly to polyurethane surfaces below a shear rate of approximately 500 s−1. The aim of the current work is to determine platelet adhesion properties to the polyurethane urea surface as a function of time varying shear exposure. A rotating disk system is used to study the influence of steady and pulsatile flow conditions (e.g. cardiac inflow and sawtooth waveforms) for platelet adhesion to the biomaterial surface. All experiments retain the same root mean square angular rotation velocity (29.63 rad/s) and waveform period. The disk is rotated in platelet rich bovine plasma for two hours with adhesion quantified by confocal microscopy measurements of immunofluorescently labeled bovine platelets. Platelet adhesion under pulsating flow is found to exponentially decay with increasing shear rate. Adhesion levels are found to depend upon peak platelet flux and shear rate regardless of rotational waveform. In combination with flow measurements, these results may be useful for predicting regions susceptible to thrombus formation within ventricular assist devices. PMID:24721222

Sigmoid sinus diverticulum and pulsatile tinnitus - Analysis of CT scans from 15 cases

International Nuclear Information System (INIS)

Liu, Zhaohui; Wang, Zhenchang; Xian, Junfang; Wang, Yongzhe; Liang, Xihong; Chen, Chengfang; Gong, Shusheng; Ma, Xiaobo; Li, Yi

2013-01-01

Background: Although the imaging features of sigmoid sinus diverticulum induced pulsatile tinnitus (PT) have been presented in some extent, detailed imaging findings still have not been systematically evaluated and precise diagnostic radiographic criteria has not been established. Purpose: To examine the computed tomography (CT) characteristics of sigmoid sinus diverticulum accompanied with PT. Material and Methods: Fifteen PT patients with sigmoid sinus diverticula proven by surgery were recruited after consenting. CT images of 15 patients were obtained and analyzed, including features of diverticula, brain venous systems, integrity of the sigmoid plate, and the degree of temporal bone pneumatization. Results: Sigmoid sinus diverticulum was located on the same side of PT in 15 patients. Diverticula originated at the superior curve of the sigmoid sinus in 11 patients and the descending segment of the sigmoid sinus in four patients. Sigmoid sinus diverticula focally eroded into the adjacent mastoid air cells in 12 patients and mastoid cortex in three patients. Among eight patients with unilateral dominant brain venous systems, the diverticula were seen on the dominant side in seven patients and non-dominant side in one patient. In contrast, the other seven patients showed co-dominant brain venous systems, with three presenting diverticula on the right side and four on the left. More notably, dehiscent sigmoid plate on the PT side was demonstrated in all patients. In addition, temporal bone hyper-pneumatization was found in nine patients, good and moderate pneumatization in three patients, respectively. Conclusion: Dehiscent sigmoid plate and extensive temporal bone pneumatization are two important imaging characteristics of the PT induced by sigmoid sinus diverticulum

Sigmoid sinus diverticulum and pulsatile tinnitus - Analysis of CT scans from 15 cases

Energy Technology Data Exchange (ETDEWEB)

Liu, Zhaohui; Wang, Zhenchang; Xian, Junfang; Wang, Yongzhe; Liang, Xihong [Dept. of Radiology, Capital Medical Univ., Beijing Tongren Hospital, Beijing (China); Chen, Chengfang; Gong, Shusheng; Ma, Xiaobo; Li, Yi [Dept. of Otolaryngology Head and Neck Surgery, Capital Medical Univ., Beijing Tongren Hospital, Beijing (China)

2013-09-15

Background: Although the imaging features of sigmoid sinus diverticulum induced pulsatile tinnitus (PT) have been presented in some extent, detailed imaging findings still have not been systematically evaluated and precise diagnostic radiographic criteria has not been established. Purpose: To examine the computed tomography (CT) characteristics of sigmoid sinus diverticulum accompanied with PT. Material and Methods: Fifteen PT patients with sigmoid sinus diverticula proven by surgery were recruited after consenting. CT images of 15 patients were obtained and analyzed, including features of diverticula, brain venous systems, integrity of the sigmoid plate, and the degree of temporal bone pneumatization. Results: Sigmoid sinus diverticulum was located on the same side of PT in 15 patients. Diverticula originated at the superior curve of the sigmoid sinus in 11 patients and the descending segment of the sigmoid sinus in four patients. Sigmoid sinus diverticula focally eroded into the adjacent mastoid air cells in 12 patients and mastoid cortex in three patients. Among eight patients with unilateral dominant brain venous systems, the diverticula were seen on the dominant side in seven patients and non-dominant side in one patient. In contrast, the other seven patients showed co-dominant brain venous systems, with three presenting diverticula on the right side and four on the left. More notably, dehiscent sigmoid plate on the PT side was demonstrated in all patients. In addition, temporal bone hyper-pneumatization was found in nine patients, good and moderate pneumatization in three patients, respectively. Conclusion: Dehiscent sigmoid plate and extensive temporal bone pneumatization are two important imaging characteristics of the PT induced by sigmoid sinus diverticulum.

Deconvolution of serum cortisol levels by using compressed sensing.

Directory of Open Access Journals (Sweden)

Rose T Faghih

Full Text Available The pulsatile release of cortisol from the adrenal glands is controlled by a hierarchical system that involves corticotropin releasing hormone (CRH from the hypothalamus, adrenocorticotropin hormone (ACTH from the pituitary, and cortisol from the adrenal glands. Determining the number, timing, and amplitude of the cortisol secretory events and recovering the infusion and clearance rates from serial measurements of serum cortisol levels is a challenging problem. Despite many years of work on this problem, a complete satisfactory solution has been elusive. We formulate this question as a non-convex optimization problem, and solve it using a coordinate descent algorithm that has a principled combination of (i compressed sensing for recovering the amplitude and timing of the secretory events, and (ii generalized cross validation for choosing the regularization parameter. Using only the observed serum cortisol levels, we model cortisol secretion from the adrenal glands using a second-order linear differential equation with pulsatile inputs that represent cortisol pulses released in response to pulses of ACTH. Using our algorithm and the assumption that the number of pulses is between 15 to 22 pulses over 24 hours, we successfully deconvolve both simulated datasets and actual 24-hr serum cortisol datasets sampled every 10 minutes from 10 healthy women. Assuming a one-minute resolution for the secretory events, we obtain physiologically plausible timings and amplitudes of each cortisol secretory event with R (2 above 0.92. Identification of the amplitude and timing of pulsatile hormone release allows (i quantifying of normal and abnormal secretion patterns towards the goal of understanding pathological neuroendocrine states, and (ii potentially designing optimal approaches for treating hormonal disorders.

Non-invasive estimation of pulsatile flow and differential pressure in an implantable rotary blood pump for heart failure patients

International Nuclear Information System (INIS)

AlOmari, A H; Savkin, A V; Karantonis, D M; Lim, E; Lovell, N H

2009-01-01

We propose dynamical models for pulsatile flow and head estimation in an implantable rotary blood pump. Pulsatile flow and head data were obtained using a circulatory mock loop where fluid solutions with different values of viscosities were used as a blood analogue with varying haematocrit (HCT). Noninvasive measurements of power and pump speed were used with HCT values as inputs to the flow model while the estimated flow was used with the speed as inputs to a head estimation model. Linear regression analysis between estimated and measured flows obtained from a mock loop resulted in a highly significant correlation (R 2 = 0.982) and a mean absolute error (e) of 0.323 L min −1 , while for head, R 2 = 0.933 and e = 7.682 mmHg were obtained. R 2 = 0.849 and e = 0.584 L min −1 were obtained when the same model derived in the mock loop was used for flow estimation in ex vivo porcine data (N = 6). Furthermore, in the steady state, the solution of the presented flow model can be described by a previously designed and verified static model. The models developed herein will play a vital role in developing a robust control system of the pump flow coping with changing physiological demands

Analysis of pulsatile retinal movements by spectral-domain low-coherence interferometry: influence of age and glaucoma on the pulse wave.

Directory of Open Access Journals (Sweden)

Carolyne Dion

Full Text Available Recent studies have shown that ocular hemodynamics and eye tissue biomechanical properties play an important role in the pathophysiology of glaucoma. Nevertheless, better, non-invasive methods to assess these characteristics in vivo are essential for a thorough understanding of degenerative mechanisms. Here, we propose to measure ocular tissue movements induced by cardiac pulsations and study the ocular pulse waveform as an indicator of tissue compliance. Using a novel, low-cost and non-invasive device based on spectral-domain low coherence interferometry (SD-LCI, we demonstrate the potential of this technique to differentiate ocular hemodynamic and biomechanical properties. We measured the axial movement of the retina driven by the pulsatile ocular blood flow in 11 young healthy individuals, 12 older healthy individuals and 15 older treated glaucoma patients using our custom-made SD-OCT apparatus. The cardiac pulse was simultaneously measured through the use of an oximeter to allow comparison. Spectral components up to the second harmonic were obtained and analyzed. For the different cohorts, we computed a few parameters that characterize the three groups of individuals by analyzing the movement of the retinal tissue at two locations, using this simple, low-cost interferometric device. Our pilot study indicates that spectral analysis of the fundus pulsation has potential for the study of ocular biomechanical and vascular properties, as well as for the study of ocular disease.

Experimental and theoretical investigations of Lantana camara oil diffusion from polyacrylonitrile membrane for pulsatile drug delivery system

Energy Technology Data Exchange (ETDEWEB)

Verma, Vivek [Department of Chemistry, Indian Institute of Science Education and Research (IISER), Pune 411008 (India); Balasubramanian, K., E-mail: meetkbs@gmail.com [Department of Materials Engineering, Defence Institute of Advance Technology (DIAT), Ministry of Defence, Girinagar, Pune 411025 (India)

2014-08-01

Porous composite membrane of polyacrylonitrile (PAN) and Lantana camara essential oil was synthesized by solvent casting method. Stability of oil in PAN solution was measured by XiGo nano tool indicating constant relaxation time of 1487 time/s. Pore size of few microns confirmed by electron microscopy was supported by atomic force microscopy indicating roughness factor of 0.9 nm. Contact angle of 2° inveterates superhydrophilicity of the composite membrane. Membrane showed excellent antibacterial activity against both Gram-positive Bacillus subtilis and Gram-negative Escherichia coli with a 7–10 mm zone of inhibition. In vitro release of Lantana oil from the composite membrane was carried out in isotonic phosphate buffer solution (pH = 7.4). Lantana oil was released for 9 h, lag time of 3 h with constant 33% release confirmed PAN membranes as potential system for pulsatile drug delivery applications. Diffusion of E-caryophyllene (antibacterial component of oil) which was studied through molecular simulation using Material Studio software ensued diffusion coefficient value of 1.11 ∗ 10{sup −9} m{sup 2}/s. Biocompatibility of the composite membrane was assessed by mouse embryonic fibroblast cell line (NIH 3T3) through MTT assay indicating more than 91% viable cell even at 200 μg/mL concentration. Such membranes can be efficiently used in biomedical applications as antibacterial and antifungal agent. - Highlights: • Pulsatile release • Lantana oil–PAN composite membrane as antibacterial material • Enhanced bactericidal activity of the membrane.

Pulsatile atheroprone shear stress affects the expression of transient receptor potential channels in human endothelial cells

DEFF Research Database (Denmark)

Thilo, Florian; Vorderwülbecke, Bernd J; Marki, Alex

2012-01-01

in comparison with endothelial cells grown under static conditions. There was a significant association between the expression of TRPC6 and tumor necrosis factor-α mRNA in human vascular tissue. No-flow and atheroprone flow conditions are equally characterized by an increase in the expression of tumor necrosis......The goal of the study was to assess whether pulsatile atheroprone shear stress modulates the expression of transient receptor potential (TRP) channels, TRPC3, TRPC6, TRPM7, and TRPV1 mRNA, in human umbilical vascular endothelial cells. Exposure of cultured vascular endothelial cells to defined...

Hormones

Science.gov (United States)

Hormones are your body's chemical messengers. They travel in your bloodstream to tissues or organs. They work ... glands, which are special groups of cells, make hormones. The major endocrine glands are the pituitary, pineal, ...

Cardiac-driven Pulsatile Motion of Intracranial Cerebrospinal Fluid Visualized Based on a Correlation Mapping Technique.

Science.gov (United States)

Yatsushiro, Satoshi; Sunohara, Saeko; Hayashi, Naokazu; Hirayama, Akihiro; Matsumae, Mitsunori; Atsumi, Hideki; Kuroda, Kagayaki

2018-04-10

A correlation mapping technique delineating delay time and maximum correlation for characterizing pulsatile cerebrospinal fluid (CSF) propagation was proposed. After proofing its technical concept, this technique was applied to healthy volunteers and idiopathic normal pressure hydrocephalus (iNPH) patients. A time-resolved three dimensional-phase contrast (3D-PC) sampled the cardiac-driven CSF velocity at 32 temporal points per cardiac period at each spatial location using retrospective cardiac gating. The proposed technique visualized distributions of propagation delay and correlation coefficient of the PC-based CSF velocity waveform with reference to a waveform at a particular point in the CSF space. The delay time was obtained as the amount of time-shift, giving the maximum correlation for the velocity waveform at an arbitrary location with that at the reference location. The validity and accuracy of the technique were confirmed in a flow phantom equipped with a cardiovascular pump. The technique was then applied to evaluate the intracranial CSF motions in young, healthy (N = 13), and elderly, healthy (N = 13) volunteers and iNPH patients (N = 13). The phantom study demonstrated that root mean square error of the delay time was 2.27%, which was less than the temporal resolution of PC measurement used in this study (3.13% of a cardiac cycle). The human studies showed a significant difference (P correlation coefficient between the young, healthy group and the other two groups. A significant difference (P correlation coefficients in intracranial CSF space among all groups. The result suggests that the CSF space compliance of iNPH patients was lower than that of healthy volunteers. The correlation mapping technique allowed us to visualize pulsatile CSF velocity wave propagations as still images. The technique may help to classify diseases related to CSF dynamics, such as iNPH.

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

Science.gov (United States)

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.

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

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.

Experience With a Long-term Pulsatile Ventricular Assist Device as a Bridge to Heart Transplant in Adults.

Science.gov (United States)

Gómez Bueno, Manuel; Segovia Cubero, Javier; Serrano Fiz, Santiago; Ugarte Basterrechea, Juan; Hernández Pérez, Francisco José; Goirigolzarri Artaza, Josebe; Castedo Mejuto, Evaristo; Burgos Lázaro, Raúl; García Montero, Carlos; Moñivas Palomero, Vanessa; Mingo Santos, Susana; González Román, Ana Isabel; Álvarez Avelló, José Manuel; Vidal Fernández, Mercedes; Forteza Gil, Alberto; Alonso-Pulpón, Luis

2017-09-01

Most long-term ventricular assist devices (VADs) that are currently implanted are intracorporeal continuous-flow devices. Their main limitations include their high cost and inability to provide biventricular support. The aim of this study was to describe the results of using paracorporeal pulsatile-flow VADs as a bridge to transplant (BTT) in adult patients. Retrospective analysis of the characteristics, complications, and outcomes of a single-center case series of consecutive patients treated with the EXCOR VAD as BTT between 2009 and 2015. During the study period, 25 VADs were implanted, 6 of them biventricular. Ventricular assist devices were indicated directly as a BTT in 12 patients and as a bridge to decision in 13 due to the presence of potentially reversible contraindications or chance of heart function recovery. Twenty patients (80%) were successfully bridged to heart transplant after a median of 112 days (range, 8-239). The main complications included infectious (52% of patients), neurological events (32%, half of them fatal), bleeding (28%), and VAD malfunction requiring component replacement (28%). Eighty percent of patients with the EXCOR VAD as BTT achieved the goal after an average of almost 4 months of support. The most frequent complications were infectious, and the most severe were neurological. In our enivonment, the use of these pulsatile-flow VAD as BTT is a feasible strategy that obtains similar outcomes to those of intracorporeal continuous-flow devices. Copyright © 2016 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

The pulsatility index and the resistive index in renal arteries. Associations with long-term progression in chronic renal failure

DEFF Research Database (Denmark)

Petersen, L J; Petersen, J R; Talleruphuus, U

1997-01-01

The pulsatility index (PI) and the resistive index (RI) are used as pulsed-wave Doppler measurements of downstream renal artery resistance. PI and RI have been found to correlate with renal vascular resistance, filtration fraction and effective renal plasma flow in chronic renal failure. The aim...... of the present study was to evaluate the potential relationship between these indices and the rate of decline in renal function, as reflected by changes in different parameters of renal function in patients with chronic renal failure....

The pulsatility index and the resistive index in renal arteries in patients with hypertension and chronic renal failure

DEFF Research Database (Denmark)

Petersen, L J; Petersen, J R; Ladefoged, S D

1995-01-01

The pulsatility index (PI) and the resistive index (RI) are used as pulsed-wave Doppler measurement of downstream renal artery resistance. Little information is available on their value in chronic renal failure and their correlation to parameters of renal function and haemodynamics. The aim...... was to compare PI and RI of renal arteries in healthy volunteers and in patients with hypertension and chronic renal failure, and furthermore to study the correlation of these indices to measurements of renal haemodynamics and function by standard methods in patients with renal failure and hypertension....

Resistance training & beta-hydroxy-beta-methylbutyrate supplementation on hormones

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Hamid Arazi

2015-10-01

Full Text Available RESUMOIntroduction:In recent years, there was an increased interest on the effects of beta-hydroxy-beta-methylbutyrate (HMB supplementation on skeletal muscle due to its anti-catabolic effects.Objectives:To investigate the effect of HMB supplementation on body composition, muscular strength and anabolic-catabolic hormones after resistance training.Methods:Twenty amateur male athletes were randomly assigned to supplement and control groups in a double-blind crossover design and participated in four weeks resistance training. Before and after the test period fasting blood samples were obtained to determine anabolic (the growth hormone and testosterone and catabolic (cortisol hormones, and fat mass, lean body mass (LBM and muscular strength were measured. Dependent and independent t-tests were used to analyze data.Results:After the training period, there were no significant differen-ces between the groups with respect to fat mass, LBM and anabolic-catabolic hormones. HMB supplementation resulted in a significantly greater strength gain (p≤0.05.Conclusion:Greater increase in strength for HMB group was not accompanied by body composition and basal circulating anabolic-catabolic hormonal changes. It seems that HMB supplementation may have beneficial effects on neurological adaptations of strength gain.

Effect of growth hormone replacement therapy on pituitary hormone secretion and hormone replacement therapies in GHD adults

DEFF Research Database (Denmark)

Hubina, Erika; Mersebach, Henriette; Rasmussen, Ase Krogh

2004-01-01

We tested the impact of commencement of GH replacement therapy in GH-deficient (GHD) adults on the circulating levels of other anterior pituitary and peripheral hormones and the need for re-evaluation of other hormone replacement therapies, especially the need for dose changes.......We tested the impact of commencement of GH replacement therapy in GH-deficient (GHD) adults on the circulating levels of other anterior pituitary and peripheral hormones and the need for re-evaluation of other hormone replacement therapies, especially the need for dose changes....

Spermatogenesis Abnormalities following Hormonal Therapy in Transwomen

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Sirachai Jindarak

2018-01-01

Full Text Available Objective. To measure spermatogenesis abnormalities in transwomen at the time of sex reassignment surgery (SRS and to analyze the association between hormonal therapy duration and infertility severity. Design. Retrospective study. Setting. University hospital. Patients. One-hundred seventy-three transwomen who underwent SRS from January 2000 to December 2015. Interventions. All orchidectomy specimens were retrospectively reviewed and classified. History of hormonal therapy duration was retrieved from medical records. Main Outcome Measures. Histological examinations of orchidectomy specimens were performed to assess spermatogenesis. Results. One-hundred seventy-three orchidectomy specimens were evaluated. Histological examinations showed maturation arrest in 36.4%, hypospermatogenesis in 26%, Sertoli cell-only syndrome in 20.2%, normal spermatogenesis in 11%, and seminiferous tubule hyalinization in 6.4% of the specimens. Spermatogenesis abnormality severity was not associated with the total therapy duration (P=0.81 or patient age at the time of surgery (P=0.88. Testicular volumes and sizes were associated with spermatogenesis abnormality severity (P=0.001 and P=0.026, right testicle and left testicle, resp.. Conclusion(s. Feminizing hormonal treatment leads to reductions in testicular germ cell levels. All transwomen should be warned about this consequence, and gamete preservation should be offered before starting hormonal treatment.

CT evaluation of sigmoid plate dehiscence causing pulsatile tinnitus

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Zhao, Pengfei; Lv, Han; Dong, Cheng; Wang, Zhenchang [Capital Medical University, Department of Radiology, Beijing Friendship Hospital, Beijing (China); Niu, Yantao; Xian, Junfang [Capital Medical University, Department of Radiology, Beijing Tongren Hospital, Beijing (China)

2016-01-15

To evaluate the characteristics of sigmoid plate dehiscence (SPD) causing pulsatile tinnitus (PT) on CT arteriography and venography (CTA + V). Thirty PT patients treated successfully with SPD reconstruction were enrolled. Sixty asymptomatic patients were matched. The location, extent, number of SPD cases and concomitant signs, including venous outflow dominance, transverse sinus stenosis, high jugular bulb, temporal bone pneumatization, height of pituitary gland and pituitary fossa, abnormal mastoid emissary vein, were detected and compared using CTA + V. More than one SPD was found on the symptomatic side in 13/30 PT patients (43.3 %). The upper segment of the sigmoid plate was involved in 29/44 SPDs in the vertical direction (65.9 %); the lateral wall was involved in 38/44 SPDs in the horizontal direction (86.4 %). Singular SPD was detected in 3/60 asymptomatic patients (1.67 ± 0.35 mm{sup 2}), less so in PT patients (7.97 ± 5.17 mm{sup 2}). Compared with the control group, ipsilateral venous outflow dominance, high jugular bulb and bilateral transverse sinus stenosis were more common in the PT group, together with deeper pituitary fossa and flatter pituitary glands. SPD causing PT has characteristic CT findings. It may be generated by vascular or intracranial pressure abnormalities and act as a common key to triggering PT's perception. (orig.)

CT evaluation of sigmoid plate dehiscence causing pulsatile tinnitus

International Nuclear Information System (INIS)

Zhao, Pengfei; Lv, Han; Dong, Cheng; Wang, Zhenchang; Niu, Yantao; Xian, Junfang

2016-01-01

To evaluate the characteristics of sigmoid plate dehiscence (SPD) causing pulsatile tinnitus (PT) on CT arteriography and venography (CTA + V). Thirty PT patients treated successfully with SPD reconstruction were enrolled. Sixty asymptomatic patients were matched. The location, extent, number of SPD cases and concomitant signs, including venous outflow dominance, transverse sinus stenosis, high jugular bulb, temporal bone pneumatization, height of pituitary gland and pituitary fossa, abnormal mastoid emissary vein, were detected and compared using CTA + V. More than one SPD was found on the symptomatic side in 13/30 PT patients (43.3 %). The upper segment of the sigmoid plate was involved in 29/44 SPDs in the vertical direction (65.9 %); the lateral wall was involved in 38/44 SPDs in the horizontal direction (86.4 %). Singular SPD was detected in 3/60 asymptomatic patients (1.67 ± 0.35 mm 2 ), less so in PT patients (7.97 ± 5.17 mm 2 ). Compared with the control group, ipsilateral venous outflow dominance, high jugular bulb and bilateral transverse sinus stenosis were more common in the PT group, together with deeper pituitary fossa and flatter pituitary glands. SPD causing PT has characteristic CT findings. It may be generated by vascular or intracranial pressure abnormalities and act as a common key to triggering PT's perception. (orig.)

Bioidentical Hormones and Menopause

Science.gov (United States)

... Endocrinologist Search Featured Resource Menopause Map™ View Bioidentical Hormones January 2012 Download PDFs English Espanol Editors Howard ... take HT for symptom relief. What are bioidentical hormones? Bioidentical hormones are identical to the hormones that ...

Seasonal and pulsatile dynamics of thyrotropin and leptin in mares maintained under a constant energy balance.

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Buff, P R; Messer, N T; Cogswell, A M; Johnson, P J; Keisler, D H; Ganjam, V K

2007-11-01

The objective of this study was to determine if seasonal and/or pulsatile variations occur in plasma concentrations of thyrotropin (TSH) and leptin in mares while maintaining a constant energy balance. Blood samples were collected every 20 min during a 24h period in winter and again in summer from six Quarter Horse type mares. Plasma concentrations of TSH, leptin, and T(4) were determined by radioimmunoassay. No differences were observed in body weight between winter (388.1+/-12.5 kg) and summer (406.2+/-12.5 kg; P=0.11). Plasma concentrations of TSH were greater in the summer (2.80+/-0.07 ng/ml) when compared to winter (0.97+/-0.07 ng/ml; P<0.001). Pulse frequency of TSH was not different between winter (6.17+/-0.78 pulses/24h) and summer (5.33+/-0.78 pulses/24h; P=0.49). Mean TSH pulse amplitude, pulse area, and area under the curve were all greater in summer compared to winter (3.11+/-0.10 ng/ml versus 1.20+/-0.10 ng/ml, 24.86+/-0.10 ng/ml min versus 13.46+/-1.90 ng/ml min, 3936+/-72.93 ng/ml versus 1284+/-72.93 ng/ml, respectively; P<0.01). Mean concentrations of leptin were greater in summer (2.48+/-0.17 ng/ml) compared to winter (0.65+/-0.17 ng/ml; P<0.001). Pulsatile secretion patterns of leptin were not observed in any horses during experimentation. Mean concentrations of T(4) were greater in winter (20.3+/-0.4 ng/ml) compared to summer (18.2+/-0.4 ng/ml; P<0.001). These seasonal differences between winter and summer provide evidence of possible seasonal regulation of TSH and leptin.

BLOOD METABOLIC HORMONES AND LEPTIN IN GROWING LAMBS

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Zvonko Antunović

2010-12-01

Full Text Available The aim of this paper is to determine the concentration of blood metabolic hormones and leptin levels in growing lambs. The research was carried out on Tsigai lambs in two periods (suckling and fattening during the winter feeding season. Lambs were suckling and ate a food mixture and alfalfa hay ad libitum, while during the fattening period they were fed only with the above mentioned mixture and alfalfa hay ad libitum. Their blood was analyzed on 35th and 75th day of age. Concentrations of minsulin, leptin and thyroid hormones were determined in the blood serum of lambs during both periods. In the blood of fattening lambs significantly higher (P0.05 insulin concentrations (1.05 and 0.54 μU/mL, were determined, compared to suckling lambs. A significant strong positive correlation between serum leptin and insulin (r = 0.85, P0.05. The concentration of thyroid hormones did not significantly differ depending on the period of measurement. These changes indicate that the measurement concentrations of metabolic hormones and leptin in blood are very important in order to understand the changes of metabolism and nutrient supply in growing lambs.

Growth hormone, insulin-like growth factor I and its binding proteins 1 and 3 in last trimester intrauterine growth retardation with increased pulsatility index in the umbilical artery

DEFF Research Database (Denmark)

Larsen, T; Main, K; Andersson, A M

1996-01-01

The interrelationships between maternal hormone levels and placental dysfunction in mothers bearing children with intrauterine growth retardation remain unclear. We have examined some endocrinological aspects of intrauterine growth retardation and, in particular, tested whether low levels of GH...

Low-dose prospectively electrocardiogram-gated axial dual-source CT angiography in patients with pulsatile bilateral bidirectional Glenn Shunt: an alternative noninvasive method for postoperative morphological estimation.

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Xiaopeng Ji

Full Text Available To explore the clinical value of low-dose prospectively electrocardiogram-gated axial dual-source CT angiography (low-dose PGA scanning, CTA in patients with pulsatile bilateral bidirectional Glenn shunt (bBDG as an alternative noninvasive method for postoperative morphological estimation.Twenty patients with pulsatile bBDG (mean age 4.2±1.6 years underwent both low-dose PGA scanning and conventional cardiac angiography (CCA for the morphological changes. The morphological evaluation included the anatomy of superior vena cava (SVC and pulmonary artery (PA, the anastomotic location, thrombosis, aorto-pulmonary collateral circulation, pulmonary arteriovenous malformations, etc. Objective and subjective image quality was assessed. Bland-Altman analysis and linear regression analyses were used to evaluate the correlation on measurements between CTA and CCA. Effective radiation dose of both modalities was calculated.The CT attenuation value of bilateral SVC and PA was higher than 300 HU. The average subjective image quality score was 4.05±0.69. The morphology of bilateral SVC and PA was displayed completely and intuitively by CTA images. There were 24 SVC above PA and 15 SVC beside PA. Thrombosis was found in 1 patient. Collateral vessels were detected in 13 patients. No pulmonary arteriovenous malformation was found in our study. A strong correlation (R2>0.8, P0.The mean effective dose of CTA and CCA was 0.50±0.17 mSv and 4.85±1.34 mSv respectively.CT angiography with a low-dose PGA scanning is an accurate and reliable noninvasive examination in the assessment of morphological changes in patients with pulsatile bBDG.

Extrinsic nerves are not involved in branchial 5-HT dynamics or pulsatile urea excretion in Gulf toadfish, Opsanus beta.

Science.gov (United States)

Cartolano, Maria C; Amador, Molly H B; Tzaneva, Velislava; Milsom, William K; McDonald, M Danielle

2017-12-01

Gulf toadfish (Opsanus beta) can switch from continuously excreting ammonia as their primary nitrogenous waste to excreting predominantly urea in distinct pulses. Previous studies have shown that the neurotransmitter serotonin (5-HT) is involved in controlling this process, but it is unknown if 5-HT availability is under central nervous control or if the 5-HT signal originates from a peripheral source. Following up on a previous study, cranial nerves IX (glossopharyngeal) and X (vagus) were sectioned to further characterize their role in controlling pulsatile urea excretion and 5-HT release within the gill. In contrast to an earlier study, nerve sectioning did not result in a change in urea pulse frequency. Total urea excretion, average pulse size, total nitrogen excretion, and percent ureotely were reduced the first day post-surgery in nerve-sectioned fish but recovered by 72h post-surgery. Nerve sectioning also had no effect on toadfish urea transporter (tUT), 5-HT transporter (SERT), or 5-HT 2A receptor mRNA expression or 5-HT and 5-hydroxyindoleacetic acid (5-HIAA) abundance in the gill, all of which were found consistently across the three gill arches except 5-HIAA, which was undetectable in the first gill arch. Our findings indicate that the central nervous system does not directly control pulsatile urea excretion or local changes in gill 5-HT and 5-HIAA abundance. Copyright © 2017 Elsevier Inc. All rights reserved.

Hormone therapy after the Women's Health Initiative: a qualitative study

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Holtrop Jodi S

2006-10-01

Full Text Available Abstract Background Publication of results from the Women's Health Initiative study in July 2002 was a landmark event in biomedical science related to postmenopausal women. The purpose of this study was to describe the impact of new hormone therapy recommendations on patients' attitudes and decision-making in a primary care practice. Methods A questionnaire including structured and open-ended questions was administered in a family practice office waiting room from August through October 2003. Rationale for taking or not taking hormone therapy was specifically sought. Women 50–70 years old attending for office visits were invited to participate. Data were analyzed qualitatively and with descriptive statistics. Chart review provided medication use rates for the entire practice cohort of which the sample was a subset. Results Respondents (n = 127 were predominantly white and well educated, and were taking hormone therapy at a higher rate (38% than the overall rate (26% for women of the same age range in this practice. Belief patterns about hormone therapy were, in order of frequency, 'use is risky', 'vindication or prior beliefs', 'benefit to me outweighs risk', and 'unaware of new recommendations'. Twenty-eight out of 78 women continued hormones use after July 2002. Of 50 women who initially stopped hormone therapy after July 2002, 12 resumed use. Women who had stopped hormone therapy were a highly symptomatic group. Responses with emotional overtones such as worry, confusion, anger, and grief were common. Conclusion Strategies for decision support about hormone therapy should explicitly take into account women's preferences about symptom relief and the trade-offs among relevant risks. Some women may need emotional support during transitions in hormone therapy use.

The role of hormonal imbalance in the development of autoimmune dacryoadenitis in endocrine orbitopathy

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V. G. Likhvantseva

2014-07-01

Full Text Available The authors analyzed the hormonal profile of patients with Graves’ disease and endocrine orbitopathy with or without autoimmune dacryoadenitis. Presented compelling evidence about the role of hormonal imbalance between thyreoglobulines and thyroidstimulating hormones in the development of autoimmune dacryoadenitis. The availability of this kind of imbalance increases the risk of involvement of lacrimal gland in the pathological process with 12.3 % up to 64.3 % in the population with Graves’ disease and endocrine orbitopathy.

Neurokinin B receptor antagonism decreases luteinising hormone pulse frequency and amplitude and delays puberty onset in the female rat.

Science.gov (United States)

Li, S Y; Li, X F; Hu, M H; Shao, B; Poston, L; Lightman, S L; O'Byrne, K T

2014-08-01

The neural mechanisms controlling puberty onset remain enigmatic. Humans with loss of function mutations in TAC3 or TACR3, the genes encoding neurokinin B (NKB) or its receptor, neurokinin-3 receptor (NK3R), respectively, present with severe congenital gonadotrophin deficiency and pubertal failure. Animal studies have shown ambiguous actions of NKB-NK3R signalling with respect to controlling puberty onset. The present study aimed to determine the role of endogenous NKB-NK3R signalling in the control of pulsatile luteinising hormone (LH) secretion and the timing of puberty onset, and also whether precocious pubertal onset as a result of an obesogenic diet is similarly regulated by this neuropeptide system. Prepubertal female rats, chronically implanted with i.c.v. cannulae, were administered SB222200, a NK3R antagonist, or artificial cerebrospinal fluid via an osmotic mini-pump for 14 days. SB222200 significantly delayed the onset of vaginal opening and first oestrus (as markers of puberty) compared to controls in both normal and high-fat diet fed animals. Additionally, serial blood sampling, via chronic indwelling cardiac catheters, revealed that the increase in LH pulse frequency was delayed and that the LH pulse amplitude was reduced in response to NK3R antagonism, regardless of dietary status. These data suggest that endogenous NKB-NK3R signalling plays a role in controlling the timing of puberty and the associated acceleration of gonadotrophin-releasing hormone pulse generator frequency in the female rat. © 2014 British Society for Neuroendocrinology.

Hormones in pain modulation and their clinical implications for pain control: a critical review.

Science.gov (United States)

Chen, Xueyin; Zhang, Jinyuan; Wang, Xiangrui

2016-07-01

Recently, more and more studies have found that pain generation, transmission and modulation are under hormonal regulation. Indeed, hormonal dysregulation is a common component of chronic pain syndromes. Studies have attempted to determine whether the relationship between the pain and its perception and hormones is a causative relationship and how these processes interrelate. This review summarizes and analyzes the current experimental data and provides an overview of the studies addressing these questions. The relationship between pain perception and endocrine effects suggests that hormones can be used as important biomarkers of chronic pain syndromes and/or be developed into therapeutic agents in the fight against pain.

Increased basal and pulsatile secretion of FSH and LH in young men with 47,XXY or 46,XX karyotypes

DEFF Research Database (Denmark)

Aksglaede, L.; Jensen, Rikke Bodin Beck; Carlsen, E.

2008-01-01

testicular failure due to supernumerary X chromosomes. DESIGN: Cross-sectional study. METHODS: In this study, 7 untreated patients with primary gonadal insufficiency due to SRY-positive 46,XX (n=4) and 46,XXY karyotypes (n=3) aged 18.8 years and 25 age-matched healthy controls participated. Reproductive...... basal, pulsatile, and total LH and FSH secretion were associated with significantly more LH peaks per 24 h in comparison with healthy controls. Thus, our data indicate that in patients with Klinefelter syndrome and XX male karyotypes the entire hypothalamic-pituitary-gonadal axis has undergone...

Hormones and absence epilepsy

NARCIS (Netherlands)

Luijtelaar, E.L.J.M. van; Tolmacheva, E.A.; Budziszewska, B.; Stein, J.

2017-01-01

Hormones have an extremely large impact on seizures and epilepsy. Stress and stress hormones are known to reinforce seizure expression, and gonadal hormones affect the number of seizures and even the seizure type. Moreover, hormonal concentrations change drastically over an individual's lifetime,

Evidence of the Presence of Thyroid Hormones in Achatina fulica Snails

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DANILO LUSTRINO

Full Text Available ABSTRACT The objective of this study was to identify thyroid hormones and to examine their putative site of synthesis in Achatina fulica snails. For this purpose, radioimmunoassays were performed for T3 and T4 before and after long starvation with or without hemolymph deproteinization. Sodium/iodide symporter activity in vivo was analyzed through 125I administration with and without KClO4 pretreatment. Only T4 was detected, and its concentration decreased due to starvation or deproteinization. However, high-performance liquid chromatography analysis also showed the presence of T2 and T3 apart from T4, but rT3 was not detected in the A. fulica hemolymph. The sodium/iodide symporter activity was greater in cerebral ganglia than digestive gland, but KClO4 treatment did not inhibit iodide uptake in any of the tissues analyzed. Altogether, our data confirm for the first time the presence of thyroid hormones in A. fulica snails and suggest their participation in the metabolism control in this species, although the putative site of hormone biosynthesis remains to be elucidated.

Evidence of the Presence of Thyroid Hormones in Achatina fulica Snails.

Science.gov (United States)

Lustrino, Danilo; Silva, Alba C M; Araujo, Iracema G; Tunholi, Victor M; Tunholi-Alves, Vinícius M; Castro, Rosane N; Carvalho, Denise P; Pinheiro, Jairo; Marassi, Michelle P

2017-01-01

The objective of this study was to identify thyroid hormones and to examine their putative site of synthesis in Achatina fulica snails. For this purpose, radioimmunoassays were performed for T3 and T4 before and after long starvation with or without hemolymph deproteinization. Sodium/iodide symporter activity in vivo was analyzed through 125I administration with and without KClO4 pretreatment. Only T4 was detected, and its concentration decreased due to starvation or deproteinization. However, high-performance liquid chromatography analysis also showed the presence of T2 and T3 apart from T4, but rT3 was not detected in the A. fulica hemolymph. The sodium/iodide symporter activity was greater in cerebral ganglia than digestive gland, but KClO4 treatment did not inhibit iodide uptake in any of the tissues analyzed. Altogether, our data confirm for the first time the presence of thyroid hormones in A. fulica snails and suggest their participation in the metabolism control in this species, although the putative site of hormone biosynthesis remains to be elucidated.

Direct Regulation of Mitochondrial RNA Synthesis by Thyroid Hormone

Science.gov (United States)

Enríquez, José A.; Fernández-Silva, Patricio; Garrido-Pérez, Nuria; López-Pérez, Manuel J.; Pérez-Martos, Acisclo; Montoya, Julio

1999-01-01

We have analyzed the influence of in vivo treatment and in vitro addition of thyroid hormone on in organello mitochondrial DNA (mtDNA) transcription and, in parallel, on the in organello footprinting patterns at the mtDNA regions involved in the regulation of transcription. We found that thyroid hormone modulates mitochondrial RNA levels and the mRNA/rRNA ratio by influencing the transcriptional rate. In addition, we found conspicuous differences between the mtDNA dimethyl sulfate footprinting patterns of mitochondria derived from euthyroid and hypothyroid rats at the transcription initiation sites but not at the mitochondrial transcription termination factor (mTERF) binding region. Furthermore, direct addition of thyroid hormone to the incubation medium of mitochondria isolated from hypothyroid rats restored the mRNA/rRNA ratio found in euthyroid rats as well as the mtDNA footprinting patterns at the transcription initiation area. Therefore, we conclude that the regulatory effect of thyroid hormone on mitochondrial transcription is partially exerted by a direct influence of the hormone on the mitochondrial transcription machinery. Particularly, the influence on the mRNA/rRNA ratio is achieved by selective modulation of the alternative H-strand transcription initiation sites and does not require the previous activation of nuclear genes. These results provide the first functional demonstration that regulatory signals, such as thyroid hormone, that modify the expression of nuclear genes can also act as primary signals for the transcriptional apparatus of mitochondria. PMID:9858589

Negative regulation of parathyroid hormone-related protein expression by steroid hormones

International Nuclear Information System (INIS)

Kajitani, Takashi; Tamamori-Adachi, Mimi; Okinaga, Hiroko; Chikamori, Minoru; Iizuka, Masayoshi; Okazaki, Tomoki

2011-01-01

Highlights: → Steroid hormones repress expression of PTHrP in the cell lines where the corresponding nuclear receptors are expressed. → Nuclear receptors are required for suppression of PTHrP expression by steroid hormones, except for androgen receptor. → Androgen-induced suppression of PTHrP expression appears to be mediated by estrogen receptor. -- Abstract: Elevated parathyroid hormone-related protein (PTHrP) is responsible for humoral hypercalcemia of malignancy (HHM), which is of clinical significance in treatment of terminal patients with malignancies. Steroid hormones were known to cause suppression of PTHrP expression. However, detailed studies linking multiple steroid hormones to PTHrP expression are lacking. Here we studied PTHrP expression in response to steroid hormones in four cell lines with excessive PTHrP production. Our study established that steroid hormones negatively regulate PTHrP expression. Vitamin D receptor, estrogen receptor α, glucocorticoid receptor, and progesterone receptor, were required for repression of PTHrP expression by the cognate ligands. A notable exception was the androgen receptor, which was dispensable for suppression of PTHrP expression in androgen-treated cells. We propose a pathway(s) involving nuclear receptors to suppress PTHrP expression.

Changes in Plasma Sex Hormone Levels in Women with Severe Concomitant Injury

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K. N Yezhova

2010-01-01

Full Text Available Objective: to perform a complex study of the plasma levels of 11 sex hormones and their functional values in women with severe concomitant injury (SCI. Subjects and methods. The study enrolled 16 women aged 18—45 years who had SCI. Admission APACHE II scores were 18.9±1.3. According to the outcome of a posttraumatic period, all the patients were divided into 2 groups: A survivors; B deceased subjects. The normal values were used to comparatively analyze the concentrations of reproductive hormones. The time course of changes in hormone concentration was studied on postoperative days 1, 3, and 7. The hormone profile was examined by BSL test kits (USA on a STAT Fax 2100 enzyme immunoanalyzer (Awareness Technology Inc., USA. The content of prolactin, luteinizing hormone, follicle-stimulating hormone, progesterone, 17-hydroxyprogesterone, dehydroepiandrosterone sulfate (DHEA-S, androstendione (A, testosterone (T, dihydrotestosterone, estrone, and estradiol (E were measured. Results. The complex study of changes in the profile of 11 plasma sex hormones was first conducted in women in the posttraumat-ic period. Moreover, the typical plasma hormonal changes were elevated prolactin levels, a decrease in the concentrations of gonadotropins, and increases in some androgens, A, T, and E. The deceased women showed lower concentrations of DHEA-S and T. Analysis revealed an inverse correlation between the plasma concentration of DHEA-S and the injury severity. This change seems to suggest that an adrenal adaptation reaction is exhausted. The changes revealed in hormonal levels are of significance in understanding the pathogenesis of SCT. This may serve as a basis for the development of new therapy modalities using reproductive hormones in the postresuscitative period. Key words: severe concomitant injury, sex hormones, prolactin, luteinizing hormone, follicle-stimulating hormone, progesterone, 17-hydroxyprogesterone, androgens, estrogens.

The Use of a Combined Regimen of GnRH Agonist Plus a Low-Dose Oral Contraceptive Improves the Spontaneous Pulsatile LH Secretory Characteristics in Patients with Polycycstic Ovary Disease After Discontinuation of Treatment

OpenAIRE

Genazzani, Alessandro D.; Battaglia, Cesare; Gamba, Ombretta; Petraglia, Felice; Malavasi, Barbara; Genazzani, Andrea R.

2000-01-01

Purpose: The fertility rate in women with polycystic ovarydisease (PCOD) is influenced by the type of treatmentreceived. The present study evaluated the possiblecorrelation between treatment and pulsatile release ofgonadotropins.

Efficacy of chemotherapy after hormone therapy for hormone receptor-positive metastatic breast cancer.

Science.gov (United States)

Mori, Ryutaro; Nagao, Yasuko

2014-01-01

According to the guidelines for metastatic breast cancer, hormone therapy for hormone receptor-positive metastatic breast cancer without life-threatening metastasis should be received prior to chemotherapy. Previous trials have investigated the sensitivity of chemotherapy for preoperative breast cancer based on the efficacy of neoadjuvant hormone therapy. In this retrospective study, we investigated the efficacy of chemotherapy for metastatic breast cancer in hormone therapy-effective and hormone therapy-ineffective cases. Patients who received chemotherapy after hormone therapy for metastatic breast cancer between 2006 and 2013 at our institution were investigated. A total of 32 patients received chemotherapy after hormone therapy for metastatic breast cancer. The median patient age was 59 years, and most of the primary tumors exhibited a T2 status. A total of 26 patients had an N(+) status, while 7 patients had human epidermal growth factor receptor 2-positive tumors. A total of 13 patients received clinical benefits from hormone therapy, with a rate of clinical benefit of subsequent chemotherapy of 30.8%, which was not significantly different from that observed in the hormone therapy-ineffective patients (52.6%). A total of 13 patients were able to continue the hormone therapy for more than 1 year, with a rate of clinical benefit of chemotherapy of 38.5%, which was not significantly different from that observed in the short-term hormone therapy patients (47.4%). The luminal A patients were able to continue hormone therapy for a significantly longer period than the non-luminal A patients (median survival time: 17.8 months vs 6.35 months, p = 0.0085). However, there were no significant differences in the response to or duration of chemotherapy. The efficacy of chemotherapy for metastatic breast cancer cannot be predicted based on the efficacy of prior hormone therapy or tumor subtype, and clinicians should administer chemotherapy in all cases of

Interactions between the thyroid hormones and the hormones of the growth hormone axis.

Science.gov (United States)

Laron, Zvi

2003-12-01

The normal secretion and action of the thyroid hormones and the hormones of the GH/IGF-I (growth hormone/ insulin-like growth factor I) axis are interdependent. Their interactions often differ in man from animal studies in rodents and sheep. Thus neonates with congenital hypothyroidism are of normal length in humans but IUGR (intrauterine growth retardation) in sheep. Postnatally normal GH/IGF-I secretion and action depends on an euthyroid state. Present knowledge on the interactions between the two axes is reviewed in states of hypo- and hyperthyroidism, states of GH/IGF-I deprivation and hypersecretion, as well as the relationship between IGF-I and thyroid cancer. Emphasis is given to data in children and aspects of linear growth and skeletal maturation.

Characterization of the neurohypophysial hormone gene loci in elephant shark and the Japanese lamprey: origin of the vertebrate neurohypophysial hormone genes

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Brenner Sydney

2009-02-01

Full Text Available Abstract Background Vasopressin and oxytocin are mammalian neurohypophysial hormones with distinct functions. Vasopressin is involved mainly in osmoregulation and oxytocin is involved primarily in parturition and lactation. Jawed vertebrates contain at least one homolog each of vasopressin and oxytocin, whereas only a vasopressin-family hormone, vasotocin, has been identified in jawless vertebrates. The genes encoding vasopressin and oxytocin are closely linked tail-to-tail in eutherian mammals whereas their homologs in chicken, Xenopus and coelacanth (vasotocin and mesotocin are linked tail-to-head. In contrast, their pufferfish homologs, vasotocin and isotocin, are located on the same strand of DNA with isotocin located upstream of vasotocin and separated by five genes. These differences in the arrangement of the two genes in different bony vertebrate lineages raise questions about their origin and ancestral arrangement. To trace the origin of these genes, we have sequenced BAC clones from the neurohypophysial gene loci in a cartilaginous fish, the elephant shark (Callorhinchus milii, and in a jawless vertebrate, the Japanese lamprey (Lethenteron japonicum. We have also analyzed the neurohypophysial hormone gene locus in an invertebrate chordate, the amphioxus (Branchiostoma floridae. Results The elephant shark neurohypophysial hormone genes encode vasotocin and oxytocin, and are linked tail-to-head like their homologs in coelacanth and non-eutherian tetrapods. Besides the hypothalamus, the two genes are also expressed in the ovary. In addition, the vasotocin gene is expressed in the kidney, rectal gland and intestine. These expression profiles indicate a paracrine role for the two hormones. The lamprey locus contains a single neurohypophysial hormone gene, the vasotocin. The synteny of genes in the lamprey locus is conserved in elephant shark, coelacanth and tetrapods but disrupted in teleost fishes. The amphioxus locus encodes a single

Acute hormonal, immunological and enzymatic responses to a basketball game

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Denis Foschini

2008-12-01

Full Text Available The objective of the present study was to analyze the acute hormonal, immunological and enzymatic responses of professional basketball players to a basketball game. The sample was composed of eight basketball athletes, with a minimum of 4 years’ experience in basketball. A real game was simulated with a total duration of 40 minutes, divided into two halves of 20 minutes each and an interval of 10 minutes between halves. Blood samples were collected before andimmediately after the game (20 ml, vacuum tube system. The variables analyzed were: testosterone and cortisol hormones, total leukocytes, neutrophils, lymphocytes, monocytes and the enzymes creatine kinase (CK and lactate dehydrogenase (LDH. Statistical analysis was with descriptive statistics and the Student’s t test for paired samples to p≤0.05. The pre (13.34 nmol/L and 301.97 nmol/L and post game (17.34 nmol/L and 395.91 nmol/L levels of testosterone and cortisol were statistically different, with higher levels after the game for both hormones. The immune cell counts exhibited significant differences for total leukocytes (6393.75 nmol/L and 9158.75 nmol/L and neutrophils (3532.5 nmol/L and 6392.62 nmol/L, with levels being higher after the game. No statistical differences were observed for the enzymatic variables. Therefore, based on the markers analyzed, testosterone and cortisol exhibited pronounced increases after the game and the samebehavior was observed for total leukocytes and neutrophils.

Acute hormonal, immunological and enzymatic responses to a basketball game

Directory of Open Access Journals (Sweden)

Denis Foschini

2008-01-01

Full Text Available The objective of the present study was to analyze the acute hormonal, immunological and enzymatic responses of professional basketball players to a basketball game. The sample was composed of eight basketball athletes, with a minimum of 4 years’ experience in basketball. A real game was simulated with a total duration of 40 minutes, divided into two halves of 20 minutes each and an interval of 10 minutes between halves. Blood samples were collected before and immediately after the game (20 ml, vacuum tube system. The variables analyzed were: testosterone and cortisol hormones, total leukocytes, neutrophils, lymphocytes, monocytes and the enzymes creatine kinase (CK and lactate dehydrogenase (LDH. Statistical analysis was with descriptive statistics and the Student’s t test for paired samples to p≤0.05. The pre (13.34 nmol/L and 301.97 nmol/L and post game (17.34 nmol/L and 395.91 nmol/L levels of testosterone and cortisol were statistically different, with higher levels after the game for both hormones. The immune cell counts exhibited significant differences for total leukocytes (6393.75 nmol/L and 9158.75 nmol/L and neutrophils (3532.5 nmol/L and 6392.62 nmol/L, with levels being higher after the game. No statistical differences were observed for the enzymatic variables. Therefore, based on the markers analyzed, testosterone and cortisol exhibited pronounced increases after the game and the same behavior was observed for total leukocytes and neutrophils.

Plurihormonal pituitary adenoma immunoreactive for thyroid-stimulating hormone, growth hormone, follicle-stimulating hormone, and prolactin.

Science.gov (United States)

Luk, Cynthia T; Kovacs, Kalman; Rotondo, Fabio; Horvath, Eva; Cusimano, Michael; Booth, Gillian L

2012-01-01

To describe the case of a patient with an unusual plurihormonal pituitary adenoma with immunoreactivity for thyroid-stimulating hormone (TSH), growth hormone, follicle-stimulating hormone, prolactin, and α-subunit. We report the clinical, laboratory, imaging, and pathology findings of a patient symptomatic from a plurihormonal pituitary adenoma and describe her outcome after surgical treatment. A 60-year-old woman presented to the emergency department with headaches, blurry vision, fatigue, palpitations, sweaty hands, and weight loss. Her medical history was notable for hyperthyroidism, treated intermittently with methimazole. Magnetic resonance imaging disclosed a pituitary macroadenoma (2.3 by 2.2 by 2.0 cm), and preoperative blood studies revealed elevated levels of TSH at 6.11 mIU/L, free thyroxine at 3.6 ng/dL, and free triiodothyronine at 6.0 pg/mL. She underwent an uncomplicated transsphenoidal resection of the pituitary adenoma. Immunostaining of tumor tissue demonstrated positivity for not only TSH but also growth hormone, follicle-stimulating hormone, prolactin, and α-subunit. The Ki-67 index of the tumor was estimated at 2% to 5%, and DNA repair enzyme O6-methylguanine-DNA methyltransferase immunostaining was mostly negative. Electron microscopy showed the ultrastructural phenotype of a glycoprotein-producing adenoma. Postoperatively, her symptoms and hyperthyroidism resolved. Thyrotropin-secreting pituitary adenomas are rare. Furthermore, recent reports suggest that 31% to 36% of adenomas may show evidence of secretion of multiple pituitary hormones. This case emphasizes the importance of considering pituitary causes of thyrotoxicosis and summarizes the clinical and pathology findings in a patient with a plurihormonal pituitary adenoma.

Observation of the CSF pulsatile flow on MRI, (2)

International Nuclear Information System (INIS)

Ohara, Shigeki; Nagai, Hajime; Suzuka, Tomonao; Matsumoto, Takashi; Banno, Tatsuo

1988-01-01

In a retrospective study of the MR images of 289 neurosurgical patients, a loss of the signal intensity (the signal-void phenomenon =SVP) of the cerebrospinal fluid in the mesencephalic aqueduct was observed in 77 patients. The CSF in the cranial cavity flows toward the spinal sac in a to-and-fro manner in response to the pulsations of the brain. Because the intracranial compliance is lower than the intraspinal compliance, the systolic expansions and diastolic reductions in the brain volume are buffered by the spinal cavity via this to-and-fro flow of CSF. The SVP reflects the CSF pulsatile flow forced out of the intracranial space into the intraspinal space by the brain's pulsations. Intracranial abnormalities can be divided into two categories according to the craniospinal compliance (CC): normal CC (communicating hydrocephalus) and decreased CC (supratentorial tumor). We may expect those conditions which increase compliance to increase the CSF flow and yield a more prominent SVP. Conversely, conditions which decrease compliance may be expected to decrease the flow and extinguish the SVP. Both the brain's pulsations and the compliance of the craniospinal cavity are closely related to the presence of the SVP in CSF, as revealed by MRI. The SVP in CSF may reflect the pressure-buffering capacity of the cranio-spinal cavity. If further investigation supports our hypothesis, it may be possible to estimate the intracranial pressure noninvasively. (author)

Novel growth hormone receptor gene mutation in a patient with Laron syndrome.

Science.gov (United States)

Arman, Ahmet; Yüksel, Bilgin; Coker, Ajda; Sarioz, Ozlem; Temiz, Fatih; Topaloglu, Ali Kemal

2010-04-01

Growth Hormone (GH) is a 22 kDa protein that has effects on growth and glucose and fat metabolisms. These effects are initiated by binding of growth hormone (GH) to growth hormone receptors (GHR) expressed in target cells. Mutations or deletions in the growth hormone receptor cause an autosomal disorder called Laron-type dwarfism (LS) characterized by high circulating levels of serum GH and low levels of insulin like growth factor-1 (IGF-1). We analyzed the GHR gene for genetic defect in seven patients identified as Laron type dwarfism. We identified two missense mutations (S40L and W104R), and four polymorphisms (S473S, L526I, G168G and exon 3 deletion). We are reporting a mutation (W104R) at exon 5 of GHR gene that is not previously reported, and it is a novel mutation.

Growth Hormone (GH) and Cardiovascular System

Science.gov (United States)

Díaz, Oscar; Devesa, Pablo

2018-01-01

This review describes the positive effects of growth hormone (GH) on the cardiovascular system. We analyze why the vascular endothelium is a real internal secretion gland, whose inflammation is the first step for developing atherosclerosis, as well as the mechanisms by which GH acts on vessels improving oxidative stress imbalance and endothelial dysfunction. We also report how GH acts on coronary arterial disease and heart failure, and on peripheral arterial disease, inducing a neovascularization process that finally increases flow in ischemic tissues. We include some preliminary data from a trial in which GH or placebo is given to elderly people suffering from critical limb ischemia, showing some of the benefits of the hormone on plasma markers of inflammation, and the safety of GH administration during short periods of time, even in diabetic patients. We also analyze how Klotho is strongly related to GH, inducing, after being released from the damaged vascular endothelium, the pituitary secretion of GH, most likely to repair the injury in the ischemic tissues. We also show how GH can help during wound healing by increasing the blood flow and some neurotrophic and growth factors. In summary, we postulate that short-term GH administration could be useful to treat cardiovascular diseases. PMID:29346331

Cerebrovascular pulsatility in patients with sleep-disordered breathing.

Science.gov (United States)

Ramos, Alberto R; Cabral, Digna; Lee, David J; Sacco, Ralph L; Rundek, Tatjana

2013-05-01

The aim of our study is to determine the association between the pulsatility index (PI), a surrogate of cerebral small vessel disease and sleep-disordered breathing (SDB). We conducted a transcranial Doppler ultrasound (TCD) study of 19 consecutive patients free of stroke and cardiovascular disease, referred for the evaluation of SDB. TCD was performed by a certified technologist. Subsequent polysomnography was performed according to the practice parameters of the American Academy of Sleep Medicine. We evaluated the association between the apnea-hypopnea index (AHI), the oxygen nadir, the blood flow velocities, and the Gosling PI, for the middle cerebral artery. We performed Spearman's rank correlation and nonparametric regression to evaluate the relationship between AHI, oxygen levels, and the PI. Median age was 48 years (range 37-83), with 52 % male sex (n = 10), and median BMI of 29.9 (range 25-40.4). The median AHI was 16.4 (0.2-69). The median PI was 0.97 (0.72-1.89) cm/s. The PI correlated with the AHI (rho = 0.44; p = 0.004) and with age (rho = 0.57; p = 0.001). Nonparametric regression adjusting for age showed a positive association between the AHI and the PI (standardized estimate = 0.88; p = 0.002). There was no relation between the oxygen nadir and the PI. We observed increased PI in patients with SDB during wakefulness. The PI could potentially be an estimate of cerebral small vessel disease in patients with SDB and hence allow evaluating cerebral hemodynamics during wakefulness with a clinically relevant device.

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

Science.gov (United States)

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.

Transition to turbulence in pulsatile flow through heart valves--a modified stability approach.

Science.gov (United States)

Bluestein, D; Einav, S

1994-11-01

The presence of turbulence in the cardiovascular system is generally an indication of some type of abnormality. Most cardiologists agree that turbulence near a valve indicates either valvular stenosis or regurgitation, depending on the phase of its occurrence during the cardiac cycle. As no satisfying analytical solutions of the stability of turbulent pulsatile flow exist, accurate, unbiased flow stability criteria are needed for the identification of turbulence initiation. The traditional approach uses a stability diagram based upon the stability of a plane Stokes layer where alpha (the Womersley parameter) is defined by the fundamental heart rate. We suggest a modified approach that involves the decomposition of alpha into its frequency components, where alpha is derived from the preferred modes induced on the flow by interaction between flow pulsation and the valve. Transition to turbulence in pulsatile flow through heart values was investigated in a pulse duplicator system using three polymer aortic valve models representing a normal aortic valve, a 65 percent stenosed valve and a 90 percent severely stenosed valve, and two mitral valve models representing a normal mitral valve and a 65 percent stenosed valve. Valve characteristics were closely simulated as to mimic the conditions that alter flow stability and initiate turbulent flow conditions. Valvular velocity waveforms were measured by laser Doppler anemometry (LDA). Spectral analysis was performed on velocity signals at selected spatial and temporal points to produce the power density spectra, in which the preferred frequency modes were identified. The spectra obtained during the rapid closure stage of the valves were found to be governed by the stenosis geometry. A shift toward higher dominant frequencies was correlated with the severity of the stenosis. According to the modified approach, stability of the flow is represented by a cluster of points, each corresponding to a specific dominant mode apparent

The Use of Fluid Mechanics to Predict Regions of Microscopic Thrombus Formation in Pulsatile VADs.

Science.gov (United States)

Topper, Stephen R; Navitsky, Michael A; Medvitz, Richard B; Paterson, Eric G; Siedlecki, Christopher A; Slattery, Margaret J; Deutsch, Steven; Rosenberg, Gerson; Manning, Keefe B

2014-03-01

We compare the velocity and shear obtained from particle image velocimetry (PIV) and computational fluid dynamics (CFD) in a pulsatile ventricular assist device (VAD) to further test our thrombus predictive methodology using microscopy data from an explanted VAD. To mimic physiological conditions in vitro , a mock circulatory loop is used with a blood analog that matched blood's viscoelastic behavior at 40% hematocrit. Under normal physiologic pressures and for a heart rate of 75 bpm, PIV data is acquired and wall shear maps are produced. The resolution of the PIV shear rate calculations are tested using the CFD and found to be in the same range. A bovine study, using a model of the 50 cc Penn State V-2 VAD, for 30 days at a constant beat rate of 75 beats per minute (bpm) provides the microscopic data whereby after the 30 days, the device is explanted and the sac surface analyzed using scanning electron microscopy (SEM) and, after immunofluorescent labeling for platelets and fibrin, confocal microscopy. Areas are examined based on PIV measurements and CFD, with special attention to low shear regions where platelet and fibrin deposition are most likely to occur. Data collected within the outlet port in a direction normal to the front wall of the VAD shows that some regions experience wall shear rates less than 500 s -1 , which increases the likelihood of platelet and fibrin deposition. Despite only one animal study, correlations between PIV, CFD, and in vivo data show promise. Deposition probability is quantified by the thrombus susceptibility potential, a calculation to correlate low shear and time of shear with deposition.

Hormonal changes in secondary impotence

International Nuclear Information System (INIS)

Salama, F.M.; El-Shabrawy, N.O.; Nosseir, S.A.; Abo El-Azayem, Naglaa.

1985-01-01

Impotence is one of the problems which is still obscure both in its aetiology and treatment. The present study deals with the possible hormonal changes in cases of secondary infertility. The study involved 25 patients diagnosed as secondary impotence. Hormonal assay was performed for the following hormones: 1. Prolaction hormone. 2. Luteinising hormone (L.H.). 3. Testosterone. 4. Follicle stimulating hormone (F.S.H.). The assay was carried out by radioimmunoassay using double antibody technique. Results are discussed

Perubahan Ketebalan Jaringan Fibroglandular pada Pemeriksaan Ultrasonografi Payudara Perempuan Menopause yang Mendapat Terapi Hormon Tibolon

Directory of Open Access Journals (Sweden)

Viscanita Viscanita

2015-12-01

side effects of tibolon on the breast tissue. This study aims to determine the thickness changes of the fibroglandular tissue due to tibolon hormone therapy. This research was done between December 2013 untill August 2015 in Department of Radiology, dr. Cipto Mangunkusumo Hospital. Design of this research is a quasi-experimental study with the amendment in the form of data retrieval breast ultrasound before and after tibolon hormone therapy. Measurements with breast ultrasound was done in four regions (superior, inferior, medial and lateral then the average change in fibroglandular thickness was analyzed. Of the 40 subjects were analyzed, there were 36 subjects showed  significant increase (p <0.001 of  breast fibroglandular tissue thickness after 3 months of tibolon hormone therapy. The body mass index (p = 0.02 and a history of hormonal contraception (p = 0,01 were factors that influence the increase of fibroglandular thickness post tibolon hormone therapy. While parity, age of first child, history of breastfeeding, age of menarche, age of menopause and history of hormonal contraception were not related. Key word: hormone therapy, tibolon, thickness of breast fibroglandular tissue Normal 0 false false false EN-US X-NONE X-NONE Steroidal Hormone Receptor Expression in Male Breast Cancer

Directory of Open Access Journals (Sweden)

Fatemeh Homaei-Shandiz

2014-01-01

Full Text Available Introduction: The etiology of male breast cancer is unclear, but hormonal levels may play a role in development of this disease. It seems that the risk of male breast cancer related to increased lifelong exposure to estrogen or reduced androgen. The aim of this study was to investigate the expression of the steroid hormone receptors including estrogen receptor (ER and progesterone receptor (PR in Iranian cases with male breast cancer. Methods: This is a prospective review of 18 cases of male breast cancer in in Omid Hospital, Mashhad, North East of Iran, between October 2001 and October 2006. ER and PR were measured by immunohistochemistry. Clinicopathologic features and family history were obtained by interview. Data were analyzed with SPSS 13 using descriptive statistics.  Results: The median age was 63.2 year. All the cases were infiltrating ductal carcinoma. A high rate of expression of ER (88.8% and PR (66.6% was found in the studied cases. Conclusion: Cancers of the male breast are significantly more likely than cancers of the female breast to express hormonal receptors.

Effects on steroid hormones secretion resulting from the acute stimulation of sectioning the superior ovarian nerve to pre-pubertal rats

Directory of Open Access Journals (Sweden)

Morales-Ledesma Leticia

2012-10-01

Full Text Available Abstract In the adult rat, neural signals arriving to the ovary via the superior ovarian nerve (SON modulate progesterone (P4, testosterone (T and estradiol (E2 secretion. The aims of the present study were to analyze if the SON in the pre-pubertal rat also modulates ovarian hormone secretion and the release of follicle stimulating hormone (FSH and luteinizing (LH hormone. P4, T, E2, FSH and LH serum levels were measured 30 or 60 minutes after sectioning the SON of pre-pubertal female rats. Our results indicate that the effects on hormone levels resulting from unilaterally or bilaterally sectioning the SON depends on the analyzed hormone, and the time lapse between surgery and autopsy, and that the treatment yielded asymmetric results. The results also suggest that in the pre-pubertal rat the neural signals arriving to the ovaries via the SON regulate the enzymes participating in P4, T and E2 synthesis in a non-parallel way, indicating that the mechanisms regulating the synthesis of each hormone are not regulated by the same signals. Also, that the changes in the steroids hormones are not explained exclusively by the modifications in gonadotropins secretion. The observed differences in hormone levels between rats sacrificed 30 and 60 min after surgery reflect the onset of the compensatory systems regulating hormones secretion.

Neonatal testosterone suppresses a neuroendocrine pulse generator required for reproduction

Science.gov (United States)

Israel, Jean-Marc; Cabelguen, Jean-Marie; Le Masson, Gwendal; Oliet, Stéphane H.; Ciofi, Philippe

2014-02-01

The pituitary gland releases hormones in a pulsatile fashion guaranteeing signalling efficiency. The determinants of pulsatility are poorly circumscribed. Here we show in magnocellular hypothalamo-neurohypophyseal oxytocin (OT) neurons that the bursting activity underlying the neurohormonal pulses necessary for parturition and the milk-ejection reflex is entirely driven by a female-specific central pattern generator (CPG). Surprisingly, this CPG is active in both male and female neonates, but is inactivated in males after the first week of life. CPG activity can be restored in males by orchidectomy or silenced in females by exogenous testosterone. This steroid effect is aromatase and caspase dependent, and is mediated via oestrogen receptor-α. This indicates the apoptosis of the CPG network during hypothalamic sexual differentiation, explaining why OT neurons do not burst in adult males. This supports the view that stereotypic neuroendocrine pulsatility is governed by CPGs, some of which are subjected to gender-specific perinatal programming.

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....

Perioperative indicators of hypocalcemia in total thyroidectomy: the role of vitamin D and parathyroid hormone.

Science.gov (United States)

Salinger, Eric M; Moore, John T

2013-12-01

Hypocalcemia is a common complication of thyroidectomy. The aim of this study was to identify risk factors for this problem. This prospective analysis included 111 patients undergoing total or completion thyroidectomy. Preoperative vitamin D levels and postoperative day 1 parathyroid hormone levels were analyzed for their predictive effects on postoperative hypocalcemia. Patients with ionized calcium hypocalcemia. Younger age and low postoperative parathyroid hormone levels are predictive of symptomatic hypocalcemia. A parathyroid hormone level outside of the reference range may indicate a need for more aggressive postoperative calcium supplementation and treatment with activated vitamin D. Older patients with normal postoperative parathyroid hormone levels may be safely discharged with appropriate calcium supplementation. Copyright © 2013 Elsevier Inc. All rights reserved.

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...

Missed hormonal contraceptives: new recommendations.

Science.gov (United States)

Guilbert, Edith; Black, Amanda; Dunn, Sheila; Senikas, Vyta

2008-11-01

To provide evidence-based guidance for women and their health care providers on the management of missed or delayed hormonal contraceptive doses in order to prevent unintended pregnancy. Medline, PubMed, and the Cochrane Database were searched for articles published in English, from 1974 to 2007, about hormonal contraceptive methods that are available in Canada and that may be missed or delayed. Relevant publications and position papers from appropriate reproductive health and family planning organizations were also reviewed. The quality of evidence is rated using the criteria developed by the Canadian Task Force on Preventive Health Care. This committee opinion will help health care providers offer clear information to women who have not been adherent in using hormonal contraception with the purpose of preventing unintended pregnancy. The Society of Obstetricians and Gynaecologists of Canada. SUMMARY STATEMENTS: 1. Instructions for what women should do when they miss hormonal contraception have been complex and women do not understand them correctly. (I) 2. The highest risk of ovulation occurs when the hormone-free interval is prolonged for more than seven days, either by delaying the start of combined hormonal contraceptives or by missing active hormone doses during the first or third weeks of combined oral contraceptives. (II) Ovulation rarely occurs after seven consecutive days of combined oral contraceptive use. (II) RECOMMENDATIONS: 1. Health care providers should give clear, simple instructions, both written and oral, on missed hormonal contraceptive pills as part of contraceptive counselling. (III-A) 2. Health care providers should provide women with telephone/electronic resources for reference in the event of missed or delayed hormonal contraceptives. (III-A) 3. In order to avoid an increased risk of unintended pregnancy, the hormone-free interval should not exceed seven days in combined hormonal contraceptive users. (II-A) 4. Back-up contraception should

Treatment of cellulite with a bipolar radiofrequency, infrared heat, and pulsatile suction device: a pilot study.

Science.gov (United States)

Wanitphakdeedecha, Rungsima; Manuskiatti, Woraphong

2006-12-01

Very few therapeutic options have proven effective in the treatment of cellulite. To evaluate the effectiveness and adverse effects of a bipolar radiofrequency (RF), infrared (IR) heat and pulsatile suction device for the treatment of cellulite. Twelve subjects were treated with the RF-light-based device. All subjects were treated twice weekly for a total number of eight to nine treatments. Subjects were evaluated using standardized photographs, and measurements of body weight and circumference of treatment sites at baseline, immediately after the last treatment, and four weeks and one year after the last treatment. Clinical improvement scores of comparable photographs using a quartile grading scale (0 = 75% improvement) were judged independently by two non-treating dermatologists after the series of treatment. The average body weights at baseline, immediately after the last treatment, and four weeks and one year after the complete treatment were 56.30, 56.05, 56.23, and 56.53 kg, respectively. The average circumferential reductions of the abdomen and thigh at the last treatment visit were 5.17 +/- 1.04 cm (6.32%+/- 1.82%) and 3.50 +/- 2.16 cm (6.23 +/- 3.58%), respectively. At four weeks after the last treatment, the average circumferential reductions of the abdomen and thigh were sustained at 3.17 +/- 2.75 cm (4.04%+/- 3.69%) and 3.50 +/- 2.04 cm (6.26%+/- 3.52%), respectively. At one year follow-up visit, the average circumferential reductions of the abdomen and thigh were maintained at 3.83 +/- 0.76 cm (4.64%+/- 1.15%) and 3.13 +/- 3.54 (5.50%+/- 6.12%), respectively. Average clinical improvement scores of the abdomen and thigh after the series of treatments were 0.75 (corresponding to approximately 25% improvement), and 1.75 (corresponding to approximately 50% improvement), respectively. A bipolar RF, IR heat and pulsatile suction device provides a beneficial effect on reduction of abdomen and thigh circumference, and smoothening of the cellulite.

Suckling behaviour and fertility in beef cows on pasture 2. Influence ...

African Journals Online (AJOL)

For two weeks prior to the start of the breeding season, the sucklingbehaviour of beef calves, separated from their dams for 12 h out of ..... BARB., C.R.. 1986. Naloxone infusion increases pulsatile luteinizing hormone release in post partum beef cows. Dom. Anim. Endocrin. 3, 49. WILLIAMS. G.L., KOTWICA. 1., SLANGER ...

Chronic food restriction and the circadian rhythms of pituitary-adrenal hormones, growth hormone and thyroid-stimulating hormone.

Science.gov (United States)

Armario, A; Montero, J L; Jolin, T

1987-01-01

Adult male Sprague-Dawley rats were subjected to food restriction so that they ate 65% of food ingested by control rats. While control rats had free access to food over the 24-hour period, food-restricted rats were provided with food daily at 10 a.m. The experimental period lasted for 34 days. On day 35, rats from both experimental groups were killed at 08.00, 11.00, 14.00, 24.00 and 02.00 h. Food restriction modified the circadian rhythms of ACTH and corticosterone. In addition, total circulating corticosterone throughout the day was higher in food-restricted than in control rats. In contrast, food restriction resulted in depressed secretion of thyroid-stimulating hormone and growth hormone. The results indicate that time of food availability entrained circadian corticosterone rhythm but not thyroid-stimulating hormone and growth hormone rhythms.

Preparation of Single-cohort Colonies and Hormone Treatment of Worker Honeybees to Analyze Physiology Associated with Role and/or Endocrine System.

Science.gov (United States)

Ueno, Takayuki; Kawasaki, Kiyoshi; Kubo, Takeo

2016-09-06

Honeybee workers are engaged in various tasks related to maintaining colony activity. The tasks of the workers change according to their age (age-related division of labor). Young workers are engaged in nursing the brood (nurse bees), while older workers are engaged in foraging for nectar and pollen (foragers). The physiology of the workers changes in association with this role shift. For example, the main function of the hypopharyngeal glands (HPGs) changes from the secretion of major royal jelly proteins (MRJPs) to the secretion of carbohydrate-metabolizing enzymes. Because worker tasks change as the workers age in typical colonies, it is difficult to discriminate the physiological changes that occur with aging from those that occur with the role shift. To study the physiological changes in worker tissues, including the HPGs, in association with the role shift, it would be useful to manipulate the honeybee colony population by preparing single-cohort colonies in which workers of almost the same age perform different tasks. Here we describe a detailed protocol for preparing single-cohort colonies for this analysis. Six to eight days after single-cohort colony preparation, precocious foragers that perform foraging tasks earlier than usual appear in the colony. Representative results indicated role-associated changes in HPG gene expression, suggesting role-associated HPG function. In addition to manipulating the colony population, analysis of the endocrine system is important for investigating role-associated physiology. Here, we also describe a detailed protocol for treating workers with 20-hydroxyecdysone (20E), an active form of ecdysone, and methoprene, a juvenile hormone analogue. The survival rate of treated bees was sufficient to examine gene expression in the HPGs. Gene expression changes were observed in response to 20E- and/or methoprene-treatment, suggesting that hormone treatments induce physiological changes of the HPGs. The protocol for hormone

Kisspeptin Signaling Is Required for the Luteinizing Hormone Response in Anestrous Ewes following the Introduction of Males

Science.gov (United States)

De Bond, Julie-Ann P.; Li, Qun; Millar, Robert P.; Clarke, Iain J.; Smith, Jeremy T.

2013-01-01

The introduction of a novel male stimulates the hypothalamic-pituitary-gonadal axis of female sheep during seasonal anestrus, leading to the resumption of follicle maturation and ovulation. How this pheromone cue activates pulsatile secretion of gonadotropin releasing hormone (GnRH)/luteinizing hormone (LH) is unknown. We hypothesised that pheromones activate kisspeptin neurons, the product of which is critical for the stimulation of GnRH neurons and fertility. During the non-breeding season, female sheep were exposed to novel males and blood samples collected for analysis of plasma LH profiles. Females without exposure to males served as controls. In addition, one hour before male exposure, a kisspeptin antagonist (P-271) or vehicle was infused into the lateral ventricle and continued for the entire period of male exposure. Introduction of a male led to elevated mean LH levels, due to increased LH pulse amplitude and pulse frequency in females, when compared to females not exposed to a male. Infusion of P-271 abolished this effect of male exposure. Brains were collected after the male effect stimulus and we observed an increase in the percentage of kisspeptin neurons co-expressing Fos, by immunohistochemistry. In addition, the per-cell expression of Kiss1 mRNA was increased in the rostral and mid (but not the caudal) arcuate nucleus (ARC) after male exposure in both aCSF and P-271 treated ewes, but the per-cell content of neurokinin B mRNA was decreased. There was also a generalized increase in Fos positive cells in the rostral and mid ARC as well as the ventromedial hypothalamus of females exposed to males. We conclude that introduction of male sheep to seasonally anestrous female sheep activates kisspeptin neurons and other cells in the hypothalamus, leading to increased GnRH/LH secretion. PMID:23469121

Causes of postpartum anoestrus in cattle in the tropics

International Nuclear Information System (INIS)

Hansel, W.; Alila, H.W.

1984-01-01

Prolonged postpartum anoestrus is a major cause of economic losses in cattle in most tropical countries. The length of the period from parturition to first oestrus varies greatly in cattle in the tropics and is influenced by many factors, including endocrine events, management, nutrition, heat and humidity, genetic-environmental interactions, diseases and internal and external parasites. Results of recent research on endocrinology of the postpartum cow are particularly relevant to the problem in tropical cattle. Development of a pulsatile pattern of pituitary luteinizing hormone (LH) secretion is necessary for induction of the first postpartum oestrus, and many cows undergo a short episode of elevated plasma progesterone levels immediately before the first oestrus. Adrenal corticosteroids inhibit development of the pulsatile pattern of LH secretion. The concept is developed that elevated levels of cortisol, resulting from the stresses of heat, high humidity, malnutrition, parasites and diseases to which tropical cattle are often exposed, contribute to anoestrus. Techniques developed for oestrous cycle synchronization of cyclic cattle have been found to induce first oestrus and a fertile ovulation in a significant percentage of anoestrous lactating beef cattle. These treatments involve short-term (6-7 day) progesterone treatments, followed by single injections of prostaglandin Fsub(2α) and insemination 80 hours later. Some success has also been achieved in shortening the postpartum interval by pulsatile administration of gonadotropin-releasing hormone which, in turn, causes pulsatile release of LH, and by administering progestational compounds for short periods of time. Improved management, particularly oestrus detection and insemination at the optimum time, could contribute greatly to reducing the postpartum interval in tropical cattle. Nutritional factors that result in reduced haemoglobin levels (trace mineral deficiencies and parasite infestations) also cause

Highly Sensitive and High-Throughput Analysis of Plant Hormones Using MS-Probe Modification and Liquid Chromatography–Tandem Mass Spectrometry: An Application for Hormone Profiling in Oryza sativa

Science.gov (United States)

Kojima, Mikiko; Kamada-Nobusada, Tomoe; Komatsu, Hirokazu; Takei, Kentaro; Kuroha, Takeshi; Mizutani, Masaharu; Ashikari, Motoyuki; Ueguchi-Tanaka, Miyako; Matsuoka, Makoto; Suzuki, Koji; Sakakibara, Hitoshi

2009-01-01

We have developed a highly sensitive and high-throughput method for the simultaneous analysis of 43 molecular species of cytokinins, auxins, ABA and gibberellins. This method consists of an automatic liquid handling system for solid phase extraction and ultra-performance liquid chromatography (UPLC) coupled with a tandem quadrupole mass spectrometer (qMS/MS) equipped with an electrospray interface (ESI; UPLC-ESI-qMS/MS). In order to improve the detection limit of negatively charged compounds, such as gibberellins, we chemically derivatized fractions containing auxin, ABA and gibberellins with bromocholine that has a quaternary ammonium functional group. This modification, that we call ‘MS-probe’, makes these hormone derivatives have a positive ion charge and permits all compounds to be measured in the positive ion mode with UPLC-ESI-qMS/MS in a single run. Consequently, quantification limits of gibberellins increased up to 50-fold. Our current method needs 180 plant samples simultaneously. Application of this method to plant hormone profiling enabled us to draw organ distribution maps of hormone species in rice and also to identify interactions among the four major hormones in the rice gibberellin signaling mutants, gid1-3, gid2-1 and slr1. Combining the results of hormone profiling data with transcriptome data in the gibberellin signaling mutants allows us to analyze relationships between changes in gene expression and hormone metabolism. PMID:19369275

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

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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.

Pulsatile flow effects on the hemodynamics of intracranial aneurysms.

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Le, Trung B; Borazjani, Iman; Sotiropoulos, Fotis

2010-11-01

High-resolution numerical simulations are carried out to systematically investigate the effect of the incoming flow waveform on the hemodynamics and wall shear stress patterns of an anatomic sidewall intracranial aneurysm model. Various wave forms are constructed by appropriately scaling a typical human waveform such that the waveform maximum and time-averaged Reynolds numbers, the Womersley number (α), and the pulsatility index (PI) are systematically varied within the human physiologic range. We show that the waveform PI is the key parameter that governs the vortex dynamics across the aneurysm neck and the flow patterns within the dome. At low PI, the flow in the dome is similar to a driven cavity flow and is characterized by a quasi-stationary shear layer that delineates the parent artery flow from the recirculating flow within the dome. At high PI, on the other hand, the flow is dominated by vortex ring formation, transport across the neck, and impingement and breakdown at the distal wall of the aneurysm dome. We further show that the spatial and temporal characteristics of the wall shear stress field on the aneurysm dome are strongly correlated with the vortex dynamics across the neck. We finally argue that the ratio between the characteristic time scale of transport by the mean flow across the neck and the time scale of vortex ring formation can be used to predict for a given sidewall aneurysm model the critical value of the waveform PI for which the hemodynamics will transition from the cavity mode to the vortex ring mode.

Gut hormones and gastric bypass

DEFF Research Database (Denmark)

Holst, Jens J.

2016-01-01

Gut hormone secretion in response to nutrient ingestion appears to depend on membrane proteins expressed by the enteroendocrine cells. These include transporters (glucose and amino acid transporters), and, in this case, hormone secretion depends on metabolic and electrophysiological events elicited...... that determines hormone responses. It follows that operations that change intestinal exposure to and absorption of nutrients, such as gastric bypass operations, also change hormone secretion. This results in exaggerated increases in the secretion of particularly the distal small intestinal hormones, GLP-1, GLP-2......, oxyntomodulin, neurotensin and peptide YY (PYY). However, some proximal hormones also show changes probably reflecting that the distribution of these hormones is not restricted to the bypassed segments of the gut. Thus, cholecystokinin responses are increased, whereas gastric inhibitory polypeptide responses...

Point-of-Care Ultrasonography to Assess Portal Vein Pulsatility and the Effect of Inhaled Milrinone and Epoprostenol in Severe Right Ventricular Failure: A Report of 2 Cases.

Science.gov (United States)

Tremblay, Jan-Alexis; Beaubien-Souligny, William; Elmi-Sarabi, Mahsa; Desjardins, Georges; Denault, André Y

2017-10-15

This article describes 2 patients with severe acute right ventricular failure causing circulatory shock. Portal vein pulsatility assessed by bedside ultrasonography suggested clinically relevant venous congestion. Management included cardiac preload reduction and combined inhalation of milrinone and epoprostenol to reduce right ventricular afterload. Portal vein ultrasonography may be useful in assessing right ventricular function in the acutely ill patient.

Adult growth hormone deficiency

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Vishal Gupta

2011-01-01

Full Text Available Adult growth hormone deficiency (AGHD is being recognized increasingly and has been thought to be associated with premature mortality. Pituitary tumors are the commonest cause for AGHD. Growth hormone deficiency (GHD has been associated with neuropsychiatric-cognitive, cardiovascular, neuromuscular, metabolic, and skeletal abnormalities. Most of these can be reversed with growth hormone therapy. The insulin tolerance test still remains the gold standard dynamic test to diagnose AGHD. Growth hormone is administered subcutaneously once a day, titrated to clinical symptoms, signs and IGF-1 (insulin like growth factor-1. It is generally well tolerated at the low-doses used in adults. Pegylated human growth hormone therapy is on the horizon, with a convenient once a week dosing.

Silent pituitary macroadenoma co-secreting growth hormone and thyroid stimulating hormone.

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Sen, Orhan; Ertorer, M Eda; Aydin, M Volkan; Erdogan, Bulent; Altinors, Nur; Zorludemir, Suzan; Guvener, Nilgun

2005-04-01

Silent pituitary adenomas are a group of tumors showing heterogenous morphological features with no hormonal function observed clinically. To date no explanation has been provided as to why these tumors remain "silent". We report a case of a silent macroadenoma with both growth hormone (GH) and thyroid stimulating hormone (TSH) staining and secretion but with no clinical manifestations, in particular, the absence of features of acromegaly or hyperthyroidism. The relevant literature is reviewed.

RELATIONSHIP BETWEEN PROLACTIN HORMONE LEVEL, MOLTING AND DUCK EGG PRODUCTION

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T. Susanti

2012-09-01

Full Text Available The aims of this study were to obtain information on the mechanism of molting and the prolactin hormone levels affecting egg production. The study utilized AP (crossbred of Alabio ♂ with Peking ♀ and PA (crossbred of Peking ♂ and Alabio ♀ ducks with a total of 180 birds. The observed variables were the duration of cessation of egg production before and after molting, the prolactin hormone level in the period of molting, the egg production period before and after molting. The data was analyzed using ANOVA, regression and correlation. The results showed that AP crossbred had fewer molting (23.33% compared to PA (50.00%. The mechanism of molting is always preceded by cessation of egg production, molting and relaying. The prolactin hormone concentrations of AP and PA in the period before and after molting were significantly higher than in the period of molting. At the egg production period before molting, the prolactin hormone concentration of AP ducks was higher than the PA ducks. So that the egg production of AP before molting (0-16 weeks was higher than the PA. The egg production of AP was higher than PA, 256.66±6.00 vs 232.22±6.64 eggs for 48 weeks. So it can be concluded that the prolactin hormone affects the molting and egg production.

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...

Menopause and Hormones

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... Consumer Information by Audience For Women Menopause and Hormones: Common Questions Share Tweet Linkedin Pin it More ... reproduction and distribution. Learn More about Menopause and Hormones Menopause--Medicines to Help You Links to other ...

Steroid hormone regulation of EMP2 expression and localization in the endometrium

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Williams Carmen J

2008-04-01

Full Text Available Abstract Background The tetraspan protein epithelial membrane protein-2 (EMP2, which mediates surface display of diverse proteins, is required for endometrial competence in blastocyst implantation, and is uniquely correlated with poor survival from endometrial adenocarcinoma tumors. Because EMP2 is differentially expressed in the various stages of the murine and human estrous cycle, we tested the hypothesis that the steroid hormones progesterone and estrogen influence EMP2 expression and localization. Methods Frozen human proliferative and secretory endometrium were collected and analyzed for EMP2 expression using SDS-PAGE/Western blot analysis. The response of EMP2 to progesterone and estradiol was determined using a combination of real-time PCR, SDS-PAGE/Western blot analysis, and confocal immunofluorescence in the human endometrial carcinoma cell line RL95-2. To confirm the in vitro results, ovariectomized mice were treated with progesterone or estradiol, and EMP2 expression was analyzed using immunohistochemistry. Results Within normal human endometrium, EMP2 expression is upregulated in the secretory phase relative to the proliferative phase. To understand the role of steroid hormones on EMP2 expression, we utilized RL95-2 cells, which express both estrogen and progesterone receptors. In RL95-2 cells, both estradiol and progesterone induced EMP2 mRNA expression, but only progesterone induced EMP2 protein expression. To compare steroid hormone regulation of EMP2 between humans and mice, we analyzed EMP2 expression in ovarectomized mice. Similar to results observed in humans, progesterone upregulated endometrial EMP2 expression and induced EMP2 translocation to the plasma membrane. Estradiol did not promote translocation to the cell surface, but moderately induced EMP2 expression in cytoplasmic compartments in vivo. Conclusion These findings suggest that targeting of EMP2 to specific locations under the influence of these steroid hormones may

Binding properties of beetal recombinant caprine growth hormone to ...

African Journals Online (AJOL)

The aim of the study was to illustrate the radio-receptor assay of beetal recombinant caprine growth hormone (rcGH). Tracer (125I-rcGH) was prepared by iodinating beetal rcGH with iodine-125 and its biological activity was analyzed by rabbit anti-rcGH antibodies. Liver microsomal membranes of the Bovidae species ...

PIV Measurement of Pulsatile Flows in 3D Curved Tubes Using Refractive Index Matching Method

Energy Technology Data Exchange (ETDEWEB)

Hong, Hyeon Ji; Ji, Ho Seong; Kim, Kyung Chun [Pusan Nat’l Univ., Busan (Korea, Republic of)

2016-08-15

Three-dimensional models of stenosis blood vessels were prepared using a 3D printer. The models included a straight pipe with axisymmetric stenosis and a pipe that was bent 10° from the center of stenosis. A refractive index matching method was utilized to measure accurate velocity fields inside the 3D tubes. Three different pulsatile flows were generated and controlled by changing the rotational speed frequency of the peristaltic pump. Unsteady velocity fields were measured by a time-resolved particle image velocimetry method. Periodic shedding of vortices occurred and moves depended on the maximum velocity region. The sizes and the positions of the vortices and symmetry are influenced by mean Reynolds number and tube geometry. In the case of the bent pipe, a recirculation zone observed at the post-stenosis could explain the possibility of blood clot formation and blood clot adhesion in view of hemodynamics.

PIV Measurement of Pulsatile Flows in 3D Curved Tubes Using Refractive Index Matching Method

International Nuclear Information System (INIS)

Hong, Hyeon Ji; Ji, Ho Seong; Kim, Kyung Chun

2016-01-01

Three-dimensional models of stenosis blood vessels were prepared using a 3D printer. The models included a straight pipe with axisymmetric stenosis and a pipe that was bent 10° from the center of stenosis. A refractive index matching method was utilized to measure accurate velocity fields inside the 3D tubes. Three different pulsatile flows were generated and controlled by changing the rotational speed frequency of the peristaltic pump. Unsteady velocity fields were measured by a time-resolved particle image velocimetry method. Periodic shedding of vortices occurred and moves depended on the maximum velocity region. The sizes and the positions of the vortices and symmetry are influenced by mean Reynolds number and tube geometry. In the case of the bent pipe, a recirculation zone observed at the post-stenosis could explain the possibility of blood clot formation and blood clot adhesion in view of hemodynamics.

[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.

Thyroid Hormone Treatment

Science.gov (United States)

... THYROID HORMONES? Desiccated ( dried and powdered ) animal thyroid ( Armour ®), now mainly obtained from pigs, was the most ... hormone can increase the risk or heart rhythm problems and bone loss making the use of thyroxine ...

Characterisation of monoclonal antibodies for human luteinising hormone, and mapping of antigenic determinants on the hormone

International Nuclear Information System (INIS)

Soos, M.; Siddle, K.

1983-01-01

Twelve mouse monoclonal antibodies for human luteinising hormone were produced. The affinities varied from 4 X 10 7 to 1 X 10 10 l/mol. The specificity of each antibody was assessed by determining the relative reactivities with luteinising hormone, thyroid stimulating hormone, follicle stimulating hormone and chorionic gonadotrophin. Six antibodies bound to the α-subunit as shown by similar reactivity with all hormones, and the remainder to the β-subunit as shown by specificity for luteinising hormone. This latter group of antibodies cross-reacted only weakly with thyroid stimulating hormone (approximately 10%) and follicle stimulating hormone (approximately 3%). Three of these antibodies also showed low reactivity towards chorionic gonadotrophin (<10%), though the others did not (80-300%). The ability of different antibodies to bind simultaneously to luteinising hormone was examined and it was shown that several distinct antigenic determinants existed on both subunits. The characterisation of monoclonal binding sites is discussed in relation to the use of antibodies in two-site immunoradiometric assays. (Auth.)

Evaluation of pulsatility index and diameter of the jugular vein and superficial body temperature as physiological indices of temperament in weaned beef calves: relationship with serum cortisol concentrations, rectal temp..

Science.gov (United States)

The relationship between temperament, pulsatility index and diameter of the jugular vein, and body temperature was assessed in Angus crossbred calves (262±24.9 days old). Temperament scores were used to classify calves as calm (n=31), intermediate (n=32), or temperamental (n=28). Blood samples were ...

Kontrasepsi Hormonal Meningkatkan Kadar α-Amylase Saliva

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Juni Handajani

2014-06-01

control. Each group consisted ten women. Criteria for issue were medication free, healthy, no orthodontic treatment, no prosthesis or crown and took hormonal contraceptives more than three months. Saliva samples were collected at afternoon (16.00-18.00 pm for 1 minute using unstimulating method. The level of SAA was measured by ELISA kit (Salimetrics LLC. Optical Density was read on a standard plate at 405 nm. Data for level SAA were analyzed using ANOVA (p<0.05. Results showed the highest level of SAA in woman who takes pill contraceptive, and there were significant differences between the three groups. This study is suggesting that the hormonal contraceptive increased the level of SAA.

Heart, lipids and hormones

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Peter Wolf

2017-05-01

Full Text Available Cardiovascular disease is the leading cause of death in general population. Besides well-known risk factors such as hypertension, impaired glucose tolerance and dyslipidemia, growing evidence suggests that hormonal changes in various endocrine diseases also impact the cardiac morphology and function. Recent studies highlight the importance of ectopic intracellular myocardial and pericardial lipid deposition, since even slight changes of these fat depots are associated with alterations in cardiac performance. In this review, we overview the effects of hormones, including insulin, thyroid hormones, growth hormone and cortisol, on heart function, focusing on their impact on myocardial lipid metabolism, cardiac substrate utilization and ectopic lipid deposition, in order to highlight the important role of even subtle hormonal changes for heart function in various endocrine and metabolic diseases.

Etiology of growth hormone deficiency in children and adolescents

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Mitrović Katarina

2013-01-01

Full Text Available Introduction. Growth hormone deficiency (GHD can be isolated or associated with deficiency of other pituitary gland hormones. According to age at diagnosis, causes of GHD are divided into congenital or acquired, and according to etiology into recognized and unknown. Objective. We analyzed etiology and prevalence of GHD, demographic data at birth, age, body height (BH and bone age at diagnosis as well as the frequency of other pituitary hormone deficiencies. Methods. The study involved 164 patients (109 male. The main criterion for the diagnosis of GHD was inadequate response of GH after two stimulation tests. The patients were classified into three groups: idiopathic, congenital and acquired GHD. Results. Idiopathic GHD was confirmed in 57.9% of patients, congenital in 11.6% and acquired in 30.5%. The mean age at diagnosis of GHD was 10.1±4.5 years. The patients with congenital GHD had most severe growth retardation (-3.4±1.4 SDS, while the patients with idiopathic GHD showed most prominent bone delay (-3.6±2.3 SDS. The prevalence of multiple pituitary hormone deficiency was 56.1%, in the group with congenital GHD 73.7%, acquired GHD 54.0% and idiopathic GHD 53.7%. The frequency of thyrotropin deficiency ranged from 88.2-100%, of adrenocorticotrophin 57.1-68.8% and of gonadotrophins deficiency 57.1- 63.0%, while deficiency of antidiuretic hormone was 2.0-25.0%. Conclusion. Although regular BH measurements enable early recognition of growth retardation, patients’ mean age and degree of growth retardation indicate that GHD is still diagnosed relatively late. A high incidence of other pituitary hormone deficiencies requires a detailed investigation of the etiology of disorders and evaluation of all pituitary functions in each child with confirmed GHD.

POLYMORPHISMS OF GROWTH HORMONE GENE IN HARINGHATA BLACK CHICKEN

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R. Saikhom

2017-06-01

Full Text Available The present study was carried out with an aim to investigate the genetic variability of growth hormone gene in Haringhata Black chicken. Blood samples were collected from 82 experimental birds and genomic DNA was extracted using the modified high salt method. Amplification of specific DNA fragment of intron 4 of growth hormone gene yielded a product size of 713 bp and was analyzed for polymorphism using PCR-SSCP technique. The banding pattern of present investigation revealed two SSCP variants AA and BB genotype in all experimental birds. In the analysed flock of Haringhata Black Chicken, the genotype frequencies were found to be 0.915 for AA and 0.085 for BB genotype. The frequencies of A and B alleles were 0.915 and 0.085 respectively which indicated A allele was predominant in the studied Haringhata Black Chicken population of the farm. The Chi Square Test revealed that studied population was not in accordance with Hardy Weinberg equilibrium with respect to intron 4 of Growth hormone gene.

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.

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.

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.

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

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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.

Um sistema de ventrículo pulmonar produzindo pressão pulsátil em único ventrículo: modelo experimental A pulmonary ventricle system producing pulsatile pressure in single ventricle: experimental model

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Bilgein Emrecan

2006-09-01

Full Text Available OBJETIVO: Pacientes com ventrículo único funcional têm prognóstico ruim, que resulta em insuficiência cardíaca, mesmo após tratamento cirúrgico. As operações derivação cavo-pulmonar (exceto pelas conexões do átrio direito ao ventrículo direito não apresentam sistema ventricular pulmonar com pressão pulsátil, além do fluxo reduzido ao ventrículo único. Para resolver o problema, tentamos criar um ventrículo pulmonar que produza pressão pulsátil experimentalmente. MÉTODO: Tentamos criar um sistema ventricular direito que produzisse pressão pulsátil. O modelo experimental foi realizado em seis ovelhas. As pressões do ventrículo pulmonar criado, da artéria pulmonar e do ventrículo esquerdo foram medidas após a saída da circulação extracorpórea. RESULTADOS: A média das pressões arteriais pulmonares sistólica e diastólica foi 15,6 ± 2,0 mmHg e 4,5 ± 1,5 mmHg. A média da pressão sistólica ventricular esquerda foi 76,6 ± 4,4 mmHg. CONCLUSÃO: Um ventrículo que produza pressão pulsátil é necessário para a regulação do fluxo da artéria pulmonar, com pressão venosa central e pressão pulmonar não pulsátil nas anomalias como ventrículos únicos funcionais.OBJECTIVE: Patients with functional single ventricle show bad survey, most of which result in cardiac failure even in the case that they are operated. The right heart bypass operations except for right atrium and right ventricle connections lack pulsatile pulmonary ventricle system besides the volume lack coming to the common ventricle. To solve the problem, we tried to create a pulmonary ventricle which produces pulsatile pressure experimentally. METHODS: We tried to form a right ventricle system which produces pulsatile pressure. The experimental model was carried on six sheep. The pressures of the created pulmonary ventricle, pulmonary artery and the left ventricle were measured after leaving the cardiopulmonary bypass. RESULTS: The mean of the

Thyroid Hormone Receptor Mutations in Cancer and Resistance to Thyroid Hormone: Perspective and Prognosis

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Meghan D. Rosen

2011-01-01

Full Text Available Thyroid hormone, operating through its receptors, plays crucial roles in the control of normal human physiology and development; deviations from the norm can give rise to disease. Clinical endocrinologists often must confront and correct the consequences of inappropriately high or low thyroid hormone synthesis. Although more rare, disruptions in thyroid hormone endocrinology due to aberrations in the receptor also have severe medical consequences. This review will focus on the afflictions that are caused by, or are closely associated with, mutated thyroid hormone receptors. These include Resistance to Thyroid Hormone Syndrome, erythroleukemia, hepatocellular carcinoma, renal clear cell carcinoma, and thyroid cancer. We will describe current views on the molecular bases of these diseases, and what distinguishes the neoplastic from the non-neoplastic. We will also touch on studies that implicate alterations in receptor expression, and thyroid hormone levels, in certain oncogenic processes.

Radioimmunoassay of polypeptide hormones and enzymes

International Nuclear Information System (INIS)

Felber, J.P.

1974-01-01

General principles of radioimmunoassay are reviewed. Detailed procedures are reviewed for the following hormones: insulin, pituitary hormones, gonadotropins, parathyroid hormone, ACTH, glucagon, gastrin, and peptide hormones. Radioimmunoassay of enzymes is also discussed. (U.S.)

Aging changes in hormone production

Science.gov (United States)

... this page: //medlineplus.gov/ency/article/004000.htm Aging changes in hormone production To use the sharing ... that produce hormones are controlled by other hormones. Aging also changes this process. For example, an endocrine ...

Kinetics of thyroid hormones

International Nuclear Information System (INIS)

Inada, Mitsuo; Nishikawa, Mitsushige; Naito, Kimikazu; Ishii, Hitoshi; Tanaka, Kiyoshi

1980-01-01

Kinetics of thyroid hormones were outlined, and recent progress in metabolism of these hormones was also described. Recently, not only T 4 and T 3 but also rT 3 , 3,3'-T 2 , 3',5'-T 2 , and 3,5-T 2 can be measured by RIA. To clarify metabolic pathways of these hormones, metabolic clearance rate and production rate of these hormones were calculated. As single-compartment analysis was insufficient to clarify disappearance curves of thyroid hormones in blood such as T 3 and T 2 of which metabolic speed was so fast, multi-compartment analysis or non-compartment analysis were also performed. Thyroid hormones seemed to be measured more precisely by constant infusion method. At the first step of T 4 metabolism, T 3 was formed by 5'-monodeiodination of T 4 , and rT 3 was formed by 5-monodeiodination of T 4 . As metabolic pathways of T 3 and rT 3 , conversion of them to 3,3'-T 2 or to 3',5'-T 2 and 3,5-T 2 was supposed. This subject will be an interesting research theme in future. (Tsunoda, M.)

Pituitary resistance to thyroid hormone associated with a base mutation in the hormone-binding domain of the human 3, 5,3[prime]-triiodothyronine receptor-[beta

Energy Technology Data Exchange (ETDEWEB)

Sasaki, Shigekazu; Nakamura, Hirotoshi; Tagami, Tetsuya; Miyoshi, Yohzi; Nogimori, Tsuyoshi; Mitsuma, Terunori; Imura, Hiroo (Kyoto Univ. School of Medicine, Aichi (Japan))

1993-05-01

Point mutations in the human T[sub 3] receptor-[beta] (TR[beta]) gene causing single amino acid substitutions have been identified in several different kindred with generalized resistance to thyroid hormone. Until now, no study has been reported on the TR gene in cases of pituitary resistance (PRTH). In the present study, the authors analyzed the TR[beta] gene in a 30-yr-old Japanese female with PRTH. She exhibited clinical features of hyperthyroidism, elevated serum thyroid hormone levels accompanied by inappropriately increased secretion of TSH, mildly elevated basal metabolic rate, and increased urinary excretion of hydroxyproline. No pituitary tumor was detected. DNA fragments of exons 3-8 of the geonomic TR[beta] gene were generated by the polymerase chain reaction and analyzed by a single stranded conformation polymorphism method. Exon 7 of the patient's TR[beta] gene showed an abnormal band, suggesting the existence of mutation(s). By subcloning and sequencing the DNA, a point mutation was identified in one allele at nucleotide 1297 (C to T), which altered the 333rd amino acid, arginine, to tryptophan. Neither of her apparently normal parents had any mutations of the TR[beta] gene. In vitro translation products of the mutant TR[beta] gene showed remarkably decreased T[sub 3]-binding activity (K[sub a], 2.1 [times] 10[sup 8] M[sup [minus]1]; normal TR[beta] K[sub a], 1.1 [times] 10[sup 10] M[sup [minus]1]). Since the molecular defect detected in a patient with PRTH is similar to that seen in subjects with generalized resistance to thyroid hormone, both types of the syndrome may represent a continuous spectrum of the same etiological defect with variable tissue resistance to thyroid hormone.

Numerical investigation of flow parameters for solid rigid spheroidal particle in a pulsatile pipe flow

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Varghese, Joffin; Jayakumar, J. S.

2017-09-01

Quantifying, forecasting and analysing the displacement rates of suspended particles are essential while discussing about blood flow analysis. Because blood is one of the major organs in the body, which enables transport phenomena, comprising of numerous blood cells. In order to model the blood flow, a flow domain was created and numerically simulated. Flow field velocity in the stream is solved utilizing Finite Volume Method utilizing FVM unstructured solver. In pulsatile flow, the effect of parameters such as average Reynolds number, tube radius, particle size and Womersley number are taken into account. In this study spheroidal particle trajectory in axial direction is simulated at different values of pulsating frequency including 1.2 Hz, 3.33 Hz and 4.00 Hz and various densities including 1005 kg/m3 and 1025 kg/m3 for the flow domain. The analysis accomplishes the interaction study of blood constituents for different flow situations which have applications in diagnosis and treatment of cardio vascular related diseases.

Plants altering hormonal milieu: A review

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Prashant Tiwari

2017-02-01

Full Text Available The aim of the present review article is to investigate the herbs which can alter the levels of hormones like Follicle stimulating hormone, Prolactin, Growth hormone, Insulin, Thyroxine, Estrogen, Progesterone, Testosterone, and Relaxin etc. Hormones are chemical signal agents produced by different endocrine glands for regulating our biological functions. The glands like pituitary, thyroid, adrenal, ovaries in women and testes in men all secrete a number of hormones with different actions. However, when these hormones are perfectly balanced then people become healthy and fit. But several factors like pathophysiological as well as biochemical changes, disease conditions, changes in the atmosphere, changes in the body, diet changes etc. may result in imbalance of various hormones that produce undesirable symptoms and disorders. As medicinal plants have their importance since ancient time, people have been using it in various ways as a source of medicine for regulation of hormonal imbalance. Moreover, it is observed that certain herbs have a balancing effect on hormones and have great impact on well-being of the people. So, considering these facts we expect that the article provides an overview on medicinal plants with potential of altering hormone level.

Plants altering hormonal milieu: A review

Directory of Open Access Journals (Sweden)

Prashant Tiwari

2017-01-01

Full Text Available The aim of the present review article is to investigate the herbs which can alter the levels of hormones like Follicle stimulating hormone, Prolactin, Growth hormone, Insulin, Thyroxine, Estrogen, Progesterone, Testosterone, and Relaxin etc. Hormones are chemical signal agents produced by different endocrine glands for regulating our biological functions. The glands like pituitary, thyroid, adrenal, ovaries in women and testes in men all secrete a number of hormones with different actions. However, when these hormones are perfectly balanced then people become healthy and fit. But several factors like pathophysiological as well as biochemical changes, disease conditions, changes in the atmosphere, changes in the body, diet changes etc. may result in imbalance of various hormones that produce undesirable symptoms and disorders. As medicinal plants have their importance since ancient time, people have been using it in various ways as a source of medicine for regulation of hormonal imbalance. Moreover, it is observed that certain herbs have a balancing effect on hormones and have great impact on well-being of the people. So, considering these facts we expect that the article provides an overview on medicinal plants with potential of altering hormone level.

Cellular localization of steroid hormone-regulated proteins during sexual development in achlya

International Nuclear Information System (INIS)

Brunt, S.A.; Silver, J.C.

1986-01-01

In the fungus Achlya ambisexualis sexual development in the male strain E87 is controlled by the steroid hormone antheridiol. To investigate the effects of antheridiol on the synthesis and/or accumulation of specific cellular proteins we have analyzed [ 35 S]methionine-labeled proteins from control and hormone-treated cells using both one-dimensional (1D) and two-dimensional (2D) PAGE. The addition of the hormone antheridiol to vegetatively growing cells of Achlya E87 was found to result in changes in the synthesis and/or accumulation of at least 16 specific proteins, which could be localized to the cytoplasmic, nuclear or cell was/cell membrane fractions. The most prominent changes observed in the hormone-treated cells included the appearance in the cytoplasmic fraction of labeled proteins at 28.4 and 24.3kD which were not detectable in control cells, and a significant enrichment in the labeling of a 24.3kD protein in the cell wall/cell membrane fraction. Quantitative changes in the [ 35 S]methionine labeling of several other proteins were noted in all three cell fractions

Concordance of self-reported hormonal contraceptive use and presence of exogenous hormones in serum among African women.

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Pyra, Maria; Lingappa, Jairam R; Heffron, Renee; Erikson, David W; Blue, Steven W; Patel, Rena C; Nanda, Kavita; Rees, Helen; Mugo, Nelly R; Davis, Nicole L; Kourtis, Athena P; Baeten, Jared M

2018-04-01

Studies that rely on self-report to investigate the relationship between hormonal contraceptive use and HIV acquisition and transmission, as well as other health outcomes, could have compromised results due to misreporting. We determined the frequency of misreported hormonal contraceptive use among African women with and at risk for HIV. We tested 1102 archived serum samples from 664 African women who had participated in prospective HIV prevention studies. Using a novel high-performance liquid chromatography-mass spectrometry assay, we quantified exogenous hormones for injectables (medroxyprogesterone acetate or norethisterone), oral contraceptives (OC) (levonorgestrel or ethinyl estradiol) and implants (levonorgestrel or etonogestrel) and compared them to self-reported use. Among women reporting hormonal contraceptive use, 258/358 (72%) of samples were fully concordant with self-report, as were 642/744 (86%) of samples from women reporting no hormonal contraceptive use. However, 42/253 (17%) of samples from women reporting injectable use, 41/66 (62%) of samples from self-reported OC users and 3/39 (8%) of samples from self-reported implant users had no quantifiable hormones. Among self-reported nonusers, 102/744 (14%) had ≥1 hormone present. Concordance between self-reported method and exogenous hormones did not differ by HIV status. Among African women with and at risk for HIV, testing of exogenous hormones revealed agreement with self-reported contraceptive use for most women. However, unexpected exogenous hormones were identified among self-reported hormonal contraceptive users and nonusers, and an important fraction of women reporting hormonal contraceptive use had no hormones detected; absence of oral contraceptive hormones could be due, at least in part, to samples taken during the hormone-free interval. Misreporting of hormonal contraceptive use could lead to biased results in observational studies of the relationship between contraceptive use and health

Hypergravity and estrogen effects on avian anterior pituitary growth hormone and prolactin levels

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Fiorindo, R. P.; Negulesco, J. A.

1980-01-01

Developing female chicks with fractured right radii were maintained for 14 d at either earth gravity (1 g) or a hypergravity state (2 g). The birds at 1 g were divided into groups which received daily injections of (1) saline, (2) 200 micrograms estrone, and (3) 400 micrograms estrone for 14 d. The 2-g birds were divided into three similarly treated groups. All 2-g birds showed significantly lower body weights than did 1-g birds. Anterior pituitary (AP) glands were excised and analyzed for growth hormone and prolactin content by analytical electrophoresis. The 1-g chicks receiving either dose of daily estrogen showed increased AP growth hormone levels, whereas hypergravity alone did not affect growth hormone content. Chicks exposed to daily estrogen and hypergravity displayed reduced growth hormone levels. AP prolactin levels were slightly increased by the lower daily estrogen dose in 1-g birds, but markedly reduced in birds exposed only to hypergravity. Doubly-treated chicks displayed normal prolactin levels. Reduced growth in 2-g birds might be due, in part, to reduced AP levels of prolactin and/or growth hormone.

A study of the pulsatile flow and its interaction with rectangular leaflets

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Ledesma, Rene; Zenit, Roberto; Pulos, Guillermo

2009-11-01

To avoid the complexity and limited understanding of the 3D pulsatile flow field through heart valves, a cardiac-like flow circuit and a test channel were designed to study the behavior of bidimensional leaflets made of hyperelastic materials. We study a simple 2D arrangement to understand the basic physics of the flow-leaflet interaction. Creating a periodic pressure gradient, measurements of leaflet deflection were obtained for different flow conditions, geometries and materials. Using PIV and Phase Locking techniques, we have obtained the leaflet motion and the time-dependent flow velocity fields. The results show that two dimensionless parameters determine the performance of a simple bi-dimensional valve, in accordance with the flow conditions applied: π1=f(sw)^1/2(E/ρ)^1/2 and π2=V/(2slw), where f is the pulsation frequency, V is the stroke volume, s, w and l are the dimensions on the leaftlet and E and ρ are the elastic modulus and density of the material, respectively. Furthermore, we have identified the conditions for which the fluid stresses can be minimized. With these results we propose a new set of parameters to improve the performance of prosthetic heart valves and, in consequence, to reduce blood damage.

Hormones and the blood-brain barrier.

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Hampl, Richard; Bičíková, Marie; Sosvorová, Lucie

2015-03-01

Hormones exert many actions in the brain, and brain cells are also hormonally active. To reach their targets in brain structures, hormones must overcome the blood-brain barrier (BBB). The BBB is a unique device selecting desired/undesired molecules to reach or leave the brain, and it is composed of endothelial cells forming the brain vasculature. These cells differ from other endothelial cells in their almost impermeable tight junctions and in possessing several membrane structures such as receptors, transporters, and metabolically active molecules, ensuring their selection function. The main ways how compounds pass through the BBB are briefly outlined in this review. The main part concerns the transport of major classes of hormones: steroids, including neurosteroids, thyroid hormones, insulin, and other peptide hormones regulating energy homeostasis, growth hormone, and also various cytokines. Peptide transporters mediating the saturable transport of individual classes of hormones are reviewed. The last paragraph provides examples of how hormones affect the permeability and function of the BBB either at the level of tight junctions or by various transporters.

Hormonal control of euryhalinity

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Takei, Yoshio; McCormick, Stephen D.; McCormick, Stephen D.; Farrell, Anthony Peter; Brauner, Colin J.

2013-01-01

Hormones play a critical role in maintaining body fluid balance in euryhaline fishes during changes in environmental salinity. The neuroendocrine axis senses osmotic and ionic changes, then signals and coordinates tissue-specific responses to regulate water and ion fluxes. Rapid-acting hormones, e.g. angiotensins, cope with immediate challenges by controlling drinking rate and the activity of ion transporters in the gill, gut, and kidney. Slow-acting hormones, e.g. prolactin and growth hormone/insulin-like growth factor-1, reorganize the body for long-term acclimation by altering the abundance of ion transporters and through cell proliferation and differentiation of ionocytes and other osmoregulatory cells. Euryhaline species exist in all groups of fish, including cyclostomes, and cartilaginous and teleost fishes. The diverse strategies for responding to changes in salinity have led to differential regulation and tissue-specific effects of hormones. Combining traditional physiological approaches with genomic, transcriptomic, and proteomic analyses will elucidate the patterns and diversity of the endocrine control of euryhalinity.

The role of soil layers in preventing ground water pollution with 17ß-estradiol hormone (E 2

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A’zam Golzari

2016-03-01

Full Text Available Background: Estrogens include estoril (E3, estradiol and estrone (E1. These chemicals are produced in human and animal bodies as well as in synthetic chemicals (drugs. Estrogens can enter water sources in different ways. When these chemicals enter the human body through water and wastewater, they have the ability to mimic or disrupt the normal estrogen activities in humans and animals. Estrogens in wastewater are able to pass soil layers and contaminate groundwater. Therefore, in this study, the removal of the hormone 17ß-estradiol (E2 as a representative of estrogens in three types of soils was studied. The selection was chosen in respect to the importance of entering the hormone into groundwater through the soil. Methods: This study was an experimental study in which the removal of the hormone E2 from different depths of three types of soils was experimented. The soils were consisted of two different textures, the silty sandy clay and the silty sand with gravel. The hormone E2 was diluted and injected into the drilled holes. Soils were characterized in the soil mechanics laboratory. Hormone extraction from the soils was performed using a centrifuge and analyzed with the Elecsys device. The results were analyzed using the IBM SPSS version 22 software. Results: The results showed that the removal rates of hormone E2 in the three types of soils were higher than 99.5%, and the removal rate in the silty sand was more than the others. In all three soil samples, the removal rates in the first layer were high. The average injected hormone in the soil decreased from 3500 to 3112 ng/l. The results showed that the adhesion and plasticity of the soil had also affected the removal rates. Conclusion: Results showed that the soil plays a significant role in the removal of E2 hormone and this hormone was reduced or eliminated in the first layers of the soils. Thus, the risk of groundwater contamination is low.

Timing of growth hormone treatment affects trabecular bone microarchitecture and mineralization in growth hormone deficient mice.

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Kristensen, Erika; Hallgrímsson, Benedikt; Morck, Douglas W; Boyd, Steven K

2010-08-01

Growth hormone (GH) is essential in the development of bone mass, and a growth hormone deficiency (GHD) in childhood is frequently treated with daily injections of GH. It is not clear what effect GHD and its treatment has on bone. It was hypothesized that GHD would result in impaired microarchitecture, and an early onset of treatment would result in a better recovery than late onset. Growth hormone deficient homozygous (lit/lit) mice of both sexes were divided into two treatment groups receiving daily injections of GH, starting at an early (21 days of age) or a late time point (35 days of age, corresponding to the end of puberty). A group of heterozygous mice with normal levels of growth hormone served as controls. In vivo micro-computed tomography scans of the fourth lumbar vertebra were obtained at five time points between 21 and 60 days of age, and trabecular morphology and volumetric BMD were analyzed to determine the effects of GH on bone microarchitecture. Early GH treatment led to significant improvements in bone volume ratio (p=0.006), tissue mineral density (p=0.005), and structure model index (p=0.004) by the study endpoint (day 60), with no detected change in trabecular thickness. Trabecular number increased and trabecular separation decreased in GHD mice regardless of treatment compared to heterozygous mice. This suggests fundamental differences in the structure of trabecular bone in GHD and GH treated mice, reflected by an increased number of thinner trabeculae in these mice compared to heterozygous controls. There were no significant differences between the late treatment group and GHD mice except for connectivity density. Taken together, these results indicate that bone responds to GH treatment initiated before puberty but not to treatment commencing post-puberty, and that GH treatment does not rescue the structure of trabecular bone to that of heterozygous controls. Copyright 2010 Elsevier Inc. All rights reserved.

Pulsatile pressure driven rarefied gas flow in long rectangular ducts

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Tsimpoukis, Alexandros; Valougeorgis, Dimitris

2018-04-01

The pulsatile pressure driven fully developed flow of a rarefied gas through an orthogonal duct is investigated, based on the time-dependent linear Bhatnagar, Gross, and Krook equation, by decomposing the flow into its steady and oscillatory parts. The investigation is focused on the oscillatory part, which is characterized by the gas rarefaction and oscillation parameters, the duct aspect ratio, and the accommodation coefficient. As the oscillation frequency is increased, the amplitude of all macroscopic quantities is decreased, while their phase angle lag is increased reaching the limiting value of π/2. As the gas becomes more rarefied, higher frequencies are needed to trigger this behavior. At small and moderate frequencies, there is a critical degree of gas rarefaction, where a maximum flow rate is obtained. As the duct aspect ratio is decreased and tends to zero, the flow rate and mean wall shear stress amplitudes are increased, while their phase angle lags are slightly affected. The accommodation coefficient has a significant effect on the amplitude and a very weak one on the phase angle of the macroscopic quantities. The computation of the inertia and viscous forces clarifies when the flow consists of only one oscillating viscous region or of two regions, namely, the inviscid piston flow in the core and the oscillating Stokes layer at the wall with the velocity overshooting. Finally, the time average oscillatory pumping power is increased as the oscillation frequency is reduced and its maximum value is one half of the corresponding steady one.

Sex hormones affect neurotransmitters and shape the adult female brain during hormonal transition periods

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Claudia eBarth

2015-02-01

Full Text Available Sex hormones have been implicated in neurite outgrowth, synaptogenesis, dendritic branching, myelination and other important mechanisms of neural plasticity. Here we review the evidence from animal experiments and human studies reporting interactions between sex hormones and the dominant neurotransmitters, such as serotonin, dopamine, GABA and glutamate. We provide an overview of accumulating data during physiological and pathological conditions and discuss currently conceptualized theories on how sex hormones potentially trigger neuroplasticity changes through these four neurochemical systems. Many brain regions have been demonstrated to express high densities for estrogen- and progesterone receptors, such as the amygdala, the hypothalamus, and the hippocampus. As the hippocampus is of particular relevance in the context of mediating structural plasticity in the adult brain, we put particular emphasis on what evidence could be gathered thus far that links differences in behavior, neurochemical patterns and hippocampal structure to a changing hormonal environment. Finally, we discuss how physiologically occurring hormonal transition periods in humans can be used to model how changes in sex hormones influence functional connectivity, neurotransmission and brain structure in vivo.

Profile of thyroid hormones in breast cancer patients

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P.P. Saraiva

2005-05-01

Full Text Available Estrogen involvement in breast cancer has been established; however, the association between breast cancer and thyroid diseases is controversial. Estrogen-like effects of thyroid hormone on breast cancer cell growth in culture have been reported. The objective of the present study was to determine the profile of thyroid hormones in breast cancer patients. Serum aliquots from 26 patients with breast cancer ranging in age from 30 to 85 years and age-matched normal controls (N = 22 were analyzed for free triiodothyronine (T3F, free thyroxine (T4F, thyroid-stimulating hormone (TSH, antiperoxidase antibody (TPO, and estradiol (E2. Estrogen receptor ß (ERß was determined in tumor tissues by immunohistochemistry. Thyroid disease incidence was higher in patients than in controls (58 vs 18%, P < 0.05. Subclinical hyperthyroidism was the most frequent disorder in patients (31%; hypothyroidism (8% and positive anti-TPO antibodies (19% were also found. Subclinical hypothyroidism was the only dysfunction (18% found in controls. Hyperthyroidism was associated with postmenopausal patients, as shown by significantly higher mean T3 and T4 values and lower TSH levels in this group of breast cancer patients than in controls. The majority of positive ERß tumors were clustered in the postmenopausal patients and all cases presenting subclinical hyperthyroidism in this subgroup concomitantly exhibited Erß-positive tumors. Subclinical hyperthyroidism was present in only one of 6 premenopausal patients. We show here that postmenopausal breast cancer patients have a significantly increased thyroid hormone/E2 ratio (P < 0.05, suggesting a possible tumor growth-promoting effect caused by this misbalance.

Hedgehog signaling activation induces stem cell proliferation and hormone release in the adult pituitary gland.

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Pyczek, Joanna; Buslei, Rolf; Schult, David; Hölsken, Annett; Buchfelder, Michael; Heß, Ina; Hahn, Heidi; Uhmann, Anja

2016-04-25

Hedgehog (HH) signaling is known to be essential during the embryonal development of the pituitary gland but the knowledge about its role in the adult pituitary and in associated tumors is sparse. In this report we investigated the effect of excess Hh signaling activation in murine pituitary explants and analyzed the HH signaling status of human adenopituitary lobes and a large cohort of pituitary adenomas. Our data show that excess Hh signaling led to increased proliferation of Sox2(+) and Sox9(+) adult pituitary stem cells and to elevated expression levels of adrenocorticotropic hormone (Acth), growth hormone (Gh) and prolactin (Prl) in the adult gland. Inhibition of the pathway by cyclopamine reversed these effects indicating that active Hh signaling positively regulates proliferative processes of adult pituitary stem cells and hormone production in the anterior pituitary. Since hormone producing cells of the adenohypophysis as well as ACTH-, GH- and PRL-immunopositive adenomas express SHH and its target GLI1, we furthermore propose that excess HH signaling is involved in the development/maintenance of hormone-producing pituitary adenomas. These findings advance the understanding of physiological hormone regulation and may open new treatment options for pituitary tumors.

Effects of the use of growth hormone in children and adolescents with juvenile idiopathic arthritis: a systematic review

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Renan Bazuco Frittoli

Full Text Available Abstract Introduction: Children with juvenile idiopathic arthritis (JIA often have impaired growth and short stature. There is evidence that the therapeutic use of growth hormone (GH is useful and safe in these patients. Objective: To analyze the effects of GH use in patients with JIA. Method: A systematic review of the literature over the last 18 years in Medline and Embase databases. The criteria were analyzed independently by the researchers. We used the following keywords: "growth hormone", "arthritis, juvenile", "arthritis, rheumatoid", "child" and "adolescent". Results: Among the 192 identified articles, 20 corresponded to the inclusion criteria. Seventeen longitudinal studies and 3 case reports were found. Most studies analyzed observed increased growth, muscle mass and bone mass using GH. Adverse effects observed were glucose intolerance, diabetes, bone deformities, osteonecrosis, reactivation of the disease and low final height. Conclusion: The majority of studies reported positive effects after the therapeutic use of GH, but some variability in response to treatment was observed. The combination of growth hormone with other drugs seems to be a good option.

Early Phthalates Exposure in Pregnant Women Is Associated with Alteration of Thyroid Hormones.

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Po-Chin Huang

Full Text Available Previous studies revealed that phthalate exposure could alter thyroid hormones during the last trimester of pregnancy. However, thyroid hormones are crucial for fetal development during the first trimester. We aimed to clarify the effect of phthalate exposure on thyroid hormones during early pregnancy.We recruited 97 pregnant women who were offered an amniocentesis during the early trimester from an obstetrics clinic in southern Taiwan from 2013 to 2014. After signing an informed consent form, we collected amniotic fluid and urine samples from pregnant women to analyze 11 metabolites, including mono-ethyl phthalate (MEP, mono-(2-ethyl-5-carboxypentyl phthalate (MECPP, mono-(2-ethylhexyl phthalate (MEHP, mono-butyl phthalate (MnBP, of 9 phthalates using liquid chromatography/ tandem mass spectrometry. We collected blood samples from each subject to analyze serum thyroid hormones including thyroxine (T4, free T4, and thyroid-binding globulin (TBG.Three phthalate metabolites were discovered to be >80% in the urine samples of the pregnant women: MEP (88%, MnBP (81% and MECPP (86%. Median MnBP and MECPP levels in pregnant Taiwanese women were 21.5 and 17.6 μg/g-creatinine, respectively, that decreased after the 2011 Taiwan DEHP scandal. Results of principal component analysis suggested two major sources (DEHP and other phthalates of phthalates exposure in pregnant women. After adjusting for age, gestational age, TBG, urinary creatinine, and other phthalate metabolites, we found a significantly negative association between urinary MnBP levels and serum T4 (β = -5.41; p-value = 0.012; n = 97 in pregnant women using Bonferroni correction.We observed a potential change in the thyroid hormones of pregnant women during early pregnancy after DnBP exposure. Additional study is necessitated to clarify these associations.

A common polymorphism of the growth hormone receptor is associated with increased responsiveness to growth hormone.

Science.gov (United States)

Dos Santos, Christine; Essioux, Laurent; Teinturier, Cécile; Tauber, Maïté; Goffin, Vincent; Bougnères, Pierre

2004-07-01

Growth hormone is used to increase height in short children who are not deficient in growth hormone, but its efficacy varies largely across individuals. The genetic factors responsible for this variation are entirely unknown. In two cohorts of short children treated with growth hormone, we found that an isoform of the growth hormone receptor gene that lacks exon 3 (d3-GHR) was associated with 1.7 to 2 times more growth acceleration induced by growth hormone than the full-length isoform (P < 0.0001). In transfection experiments, the transduction of growth hormone signaling through d3-GHR homo- or heterodimers was approximately 30% higher than through full-length GHR homodimers (P < 0.0001). One-half of Europeans are hetero- or homozygous with respect to the allele encoding the d3-GHR isoform, which is dominant over the full-length isoform. These observations suggest that the polymorphism in exon 3 of GHR is important in growth hormone pharmacogenetics.

Growth Hormone Overexpression Disrupts Reproductive Status Through Actions on Leptin

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Ji Chen

2018-03-01

Full Text Available Growth and reproduction are closely related. Growth hormone (GH-transgenic common carp exhibit accelerated growth and delayed reproductive development, which provides an amenable model to study hormone cross talk between the growth and reproductive axes. We analyzed the energy status and reproductive development in GH-transgenic common carp by using multi-tissue RNA sequencing, real-time-PCR, Western blotting, ELISA, immunofluorescence, and in vitro incubation. The expression of gys (glycogen synthase and igfbp1 (insulin-like growth factor binding protein as well as blood glucose concentrations are lower in GH-transgenic carp. Agrp1 (agouti-related protein 1 and sla (somatolactin a, which are related to appetite and lipid catabolism, are significantly higher in GH-transgenic carp. Low glucose content and increased appetite indicate disrupted metabolic and energy deprivation status in GH-transgenic carp. Meanwhile, the expression of genes, such as gnrhr2 (gonadotropin-releasing hormone receptor 2, gthα (gonadotropin hormone, alpha polypeptide, fshβ (follicle stimulating hormone, beta polypeptide, lhβ [luteinizing hormone, beta polypeptide] in the pituitary, cyp19a1a (aromatase A in the gonad, and cyp19a1b (aromatase B in the hypothalamus, are decreased in GH-transgenic carp. In contrast, pituitary gnih (gonadotropin inhibitory hormone, drd1 (dopamine receptor D1, drd3 (dopamine receptor D3, and drd4 (dopamine receptor D4 exhibit increased expression, which were associated with the retarded reproductive development. Leptin receptor mRNA was detected by fluorescence in situ hybridization in the pituitary including the pars intermedia and proximal pars distalis, suggesting a direct effect of leptin on LH. Recombinant carp Leptin protein was shown to stimulate pituitary gthα, fshβ, lhβ expression, and ovarian germinal vesicle breakdown in vitro. In addition to neuroendocrine factors, we suggest that reduced hepatic leptin signaling to the

Male patients with terminal renal failure exhibit low serum levels of antimüllerian hormone

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Dag Eckersten

2015-02-01

Full Text Available Male reproductive function is impaired during end-stage renal disease (ESRD. Disturbance of the hypothalamic-pituitary-gonadal axis, and therefore the regulation of sex hormones, is one of the major causes. Our focus was to include antimüllerian hormone (AMH and inhibin B concentrations. Twenty male patients on hemodialysis, median age 40 (26-48 years, were analyzed for follicle-stimulating hormone (FSH, luteinizing hormone (LH, prolactin, sex hormone-binding globulin (SHBG, testosterone, estradiol, AMH and inhibin B levels. We used 144 proven fertile men, median age 32 (19-44 years as a control group and analyzed differences using multiple linear regression. Males with ESRD demonstrated higher mean values for prolactin, 742 versus normal 210 mIE l−1 (95% confidence interval (CI: 60.3, 729, LH, 8.87 versus normal 4.5 IE l−1 (95% CI: 2.75, 6.14, and estradiol 89.7 versus normal 79.0 pmol l−1 (95% CI: −1.31, −0.15. Mean value for AMH was lower, 19.5 versus normal 47.3 pmol l−1 (95% CI: −37.6, −11.6. There were no differences found for FSH, SHBG, inhibin B and testosterone. The most important difference was found for AMH, a marker of Sertoli cell function in the testes, which decreased by close to 60% when compared with controls. Combined with an increase in LH, these findings may indicate a dysfunction of Sertoli cells and an effect on Leydig cells contributing to a potential mechanism of reproductive dysfunction in men with ESRD.

BIOTECHNOLOGY OF RECOMBINANT HORMONES IN DOPING

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Biljana Vitošević

2011-09-01

Full Text Available Recombinant DNA technology has allowed rapid progress in creating biosynthetic gene products for the treatment of many diseases. In this way it can produce large amounts of hormone, which is intended for the treatment of many pathological conditions. Recombinant hormones that are commonly used are insulin, growth hormone and erythropoietin. Precisely because of the availability of these recombinant hormones, it started their abuse by athletes. Experiments in animal models confirmed the potential effects of some of these hormones in increasing physical abilities, which attracted the attention of athletes who push the limits of their competitive capability by such manipulation. The risks of the use of recombinant hormones in doping include serious consequences for the health of athletes. Methods of detection of endogenous hormones from recombined based on the use of a monoclonal antibodies, capillary zone electrophoresis and protein biomarkers

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...

[Hormones and hair growth].

Science.gov (United States)

Trüeb, R M

2010-06-01

With respect to the relationship between hormones and hair growth, the role of androgens for androgenetic alopecia (AGA) and hirsutism is best acknowledged. Accordingly, therapeutic strategies that intervene in androgen metabolism have been successfully developed for treatment of these conditions. Clinical observations of hair conditions involving hormones beyond the androgen horizon have determined their role in regulation of hair growth: estrogens, prolactin, thyroid hormone, cortisone, growth hormone (GH), and melatonin. Primary GH resistance is characterized by thin hair, while acromegaly may cause hypertrichosis. Hyperprolactinemia may cause hair loss and hirsutism. Partial synchronization of the hair cycle in anagen during late pregnancy points to an estrogen effect, while aromatase inhibitors cause hair loss. Hair loss in a causal relationship to thyroid disorders is well documented. In contrast to AGA, senescent alopecia affects the hair in a diffuse manner. The question arises, whether the hypothesis that a causal relationship exists between the age-related reduction of circulating hormones and organ function also applies to hair and the aging of hair.

Heterogeneity of protein hormones

Energy Technology Data Exchange (ETDEWEB)

Rosselin, G; Bataille, D; Laburthe, M; Duran-Garcia, S [Institut National de la Sante et de la Recherche Medicale (INSERM), Hopital Saint-Antoine, 75 - Paris (France)

1975-12-01

Radioimmunoassay measures antigenic determinants of hormonal molecules in the plasmas and tissues. These estimations carried out after fractionation in biological fluids, have revealed several immunological forms of the same hormone. The main problem is in the relationship of the various immunoreactive forms to the same hormonal sequence. The similar immunoreactive forms of high molecular weight usually have low biological activity and suggest the presence of prohormone; the suggestion of prohormonal nature depends on the chronology of the incorporation of labelled leucine and enzymatic transformation of prohormone with low biological into active hormone. The forms with high molecular weight and similar immunological activity may be of another nature. Thus, it has been shown that the biosynthetic nature of a compound such as big big insulin in the rat is doubtful owing to the absence of specific incorporation of labelled leucine into the immunoprecipitate of this fraction. The significance of low molecular weight form is still little known. An example of these forms is supplied by the existence of an alpha sub-unit of gonadotrophin present in the plasma of menopausal women. The interest of analytical methods by radio-receptor, simulation of cyclase activity in the identification of biological activity of immunoreactive forms, is discussed in relation to immunological forms ofenteroglucagon. An unusual aspect of the evolutive and adaptative character of hormonal heterogeneity is given by the gastro-intestinal hormones.

Psychoendocrinological assessment of the menstrual cycle: the relationship between hormones, sexuality, and mood

NARCIS (Netherlands)

van Goozen, S. H.; Wiegant, V. M.; Endert, E.; Helmond, F. A.; van de Poll, N. E.

1997-01-01

The role of sex hormones in sexuality and mood across the menstrual cycle was investigated. Twenty-one normal health women were followed for one menstrual cycle. Blood samples were taken frequently, and analyzed for estradiol, progesterone, testosterone, androstenedione, dehydroepiandrosterone

Growth hormone-secreting pituitary adenoma:clinical and MR imaging findings

International Nuclear Information System (INIS)

Park, Hong Suk; Chang, Kee Hyun; Han, Moon Hee; Sim, Jung Suk; Lee, Sang Hyun; Song, Jae Uoo; Yoo, In Kyu; Jung, Hee Won; Yeon, Kyung Mo

1996-01-01

To describe clinical and MRI findings of growth hormone-secreting pituitary adenoma, to determine if there are any characteristic MRI findings different from those of other pituitary adenomas, to evaluate the relationship between tumor size and serum growth hormone level, and to assess the results of immunohi-stochemical study. We retrospectively analysed clinical and MRI findings of 29 patients with growth hormone-secreting pituitary adenoma confirmed by serum growth hormone level and surgery. We also evaluated the relationship between the tumor volume and serum growth hormone level, and the results of immunohistochemical study. Coronal and sagittal T1-weighted MR images in all patients and gadolinium-enhanced T1-weighted MR images in 28 patients were obtained with 2.0 T(24 cases) and 0.5 T(5 cases) MR imagers. The images were analyzed in terms of tumor size, signal intensity, degree of contrast enhancement, extent of tumor growth and the presence or absence of cystic change, hemorrhage and calcification. Clinical manifestations included facial feature change and soft tissue swelling of hands and feet(n=29), headache(n=12), impaired visual acuity(n=9), symptoms of hyperprolactinemia(n=8), visual field defect(n=5), and others(n=6). On MR images, all of the 29 cases were seen to be macroadenomas and the size of the tumors averaged 2.2cm(1-5.2cm). Supra- and infrasellar extensions were seen in 21 and 22 patients, respectively. Cavernous sinus invasion was noted in seven, and in one this was bilateral. Signal intensity was isointense with cortical grey matter in 26 cases(90%). Cystic change or necrosis was seen in eight cases(28%), hemorrhage in four(14%), and calcification in two(7%). After enhancement, most(25/28) of the tumors enhanced less than normal pituitary in degree. There was no correlation between serum growth hormone level and tumor size. Immunohistochemical study showed positive growth hormone-secreting pituitary adenomas were various and included

Growth hormone-secreting pituitary adenoma:clinical and MR imaging findings

Energy Technology Data Exchange (ETDEWEB)

Park, Hong Suk; Chang, Kee Hyun; Han, Moon Hee; Sim, Jung Suk; Lee, Sang Hyun; Song, Jae Uoo; Yoo, In Kyu; Jung, Hee Won; Yeon, Kyung Mo [Seoul National Univ. College of Medicine, Seoul (Korea, Republic of)

1996-10-01

To describe clinical and MRI findings of growth hormone-secreting pituitary adenoma, to determine if there are any characteristic MRI findings different from those of other pituitary adenomas, to evaluate the relationship between tumor size and serum growth hormone level, and to assess the results of immunohi-stochemical study. We retrospectively analysed clinical and MRI findings of 29 patients with growth hormone-secreting pituitary adenoma confirmed by serum growth hormone level and surgery. We also evaluated the relationship between the tumor volume and serum growth hormone level, and the results of immunohistochemical study. Coronal and sagittal T1-weighted MR images in all patients and gadolinium-enhanced T1-weighted MR images in 28 patients were obtained with 2.0 T(24 cases) and 0.5 T(5 cases) MR imagers. The images were analyzed in terms of tumor size, signal intensity, degree of contrast enhancement, extent of tumor growth and the presence or absence of cystic change, hemorrhage and calcification. Clinical manifestations included facial feature change and soft tissue swelling of hands and feet(n=29), headache(n=12), impaired visual acuity(n=9), symptoms of hyperprolactinemia(n=8), visual field defect(n=5), and others(n=6). On MR images, all of the 29 cases were seen to be macroadenomas and the size of the tumors averaged 2.2cm(1-5.2cm). Supra- and infrasellar extensions were seen in 21 and 22 patients, respectively. Cavernous sinus invasion was noted in seven, and in one this was bilateral. Signal intensity was isointense with cortical grey matter in 26 cases(90%). Cystic change or necrosis was seen in eight cases(28%), hemorrhage in four(14%), and calcification in two(7%). After enhancement, most(25/28) of the tumors enhanced less than normal pituitary in degree. There was no correlation between serum growth hormone level and tumor size. Immunohistochemical study showed positive growth hormone-secreting pituitary adenomas were various and included

Hormonal effects in newborns

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... page: //medlineplus.gov/ency/article/001911.htm Hormonal effects in newborns To use the sharing features on this page, please enable JavaScript. Hormonal effects in newborns occur because in the womb, babies ...

Antidiuretic hormone blood test

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... medlineplus.gov/ency/article/003702.htm Antidiuretic hormone blood test To use the sharing features on this page, please enable JavaScript. Antidiuretic blood test measures the level of antidiuretic hormone (ADH) in ...

Abnormal resting-state functional connectivity study in unilateral pulsatile tinnitus patients with single etiology: A seed-based functional connectivity study

Energy Technology Data Exchange (ETDEWEB)

Lv, Han [Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing 100050 (China); Neuroradiology Division, Department of Radiology, Stanford University, CA, 94305 (United States); Zhao, Pengfei [Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing 100050 (China); Liu, Zhaohui [Department of Radiology, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730 (China); Li, Rui; Zhang, Ling; Wang, Peng [Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing 100050 (China); Yan, Fei [Department of Radiology, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730 (China); Liu, Liheng [Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing 100050 (China); Wang, Guopeng; Zeng, Rong [Department of Otolaryngology Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing 100050 (China); Li, Ting [Department of Radiology, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730 (China); Dong, Cheng [Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing 100050 (China); Gong, Shusheng, E-mail: gongss@ccmu.edu.cn [Department of Otolaryngology Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing 100050 (China); Wang, Zhenchang, E-mail: cjr.wzhch@vip.163.com [Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing 100050 (China)

2016-11-15

Objective: Previous studies demonstrated altered regional neural activations in several brain areas in patients with pulsatile tinnitus (PT), especially indicating an important role of posterior cingulate cortex (PCC). However, few studies focused on the degree of functional connectivity (FC) of this area in PT patients. In this study, we will compare the FC of PCC in patients affected with this condition and normal controls by using resting-state functional magnetic resonance imaging (fMRI). Methods: Structural and functional MRI data were obtained from 36 unilateral PT patients with single etiology and 36 matched healthy controls. FC feature of the region of interest (PCC) were characterized using a seed-based correlation method with the voxels in the whole-brain. Results: Compared with healthy controls, patients showed significant decreased FC to the right middle temporal gyrus (MTG), right thalamus and bilateral insula. By contrast, PCC demonstrated increased functional connectivity between the precuneus, bilateral inferior parietal lobule and middle occipital gyrus. We also found correlations between the disease duration of PT and FC of PCC-right MTG (r = −0.616, p < 0.001). Conclusions: Unilateral PT patients could have abnormal FC to the PCC bilaterally in the brain. PCC, as a highly integrated brain area, is an example of nucleus that was involved in mediation between different neural networks. It might be a modulation core between visual network and auditory network. The decreased FC of MTG to PCC may indicate a down regulation of activity between PCC and auditory associated brain cortex. Decreased FC between limbic system (bilateral AI) and PCC may reflect the emotional message control in patient group. This study facilitated understanding of the underlying neuropathological process in patients with pulsatile tinnitus.

Abnormal resting-state functional connectivity study in unilateral pulsatile tinnitus patients with single etiology: A seed-based functional connectivity study

International Nuclear Information System (INIS)

Lv, Han; Zhao, Pengfei; Liu, Zhaohui; Li, Rui; Zhang, Ling; Wang, Peng; Yan, Fei; Liu, Liheng; Wang, Guopeng; Zeng, Rong; Li, Ting; Dong, Cheng; Gong, Shusheng; Wang, Zhenchang

2016-01-01

Objective: Previous studies demonstrated altered regional neural activations in several brain areas in patients with pulsatile tinnitus (PT), especially indicating an important role of posterior cingulate cortex (PCC). However, few studies focused on the degree of functional connectivity (FC) of this area in PT patients. In this study, we will compare the FC of PCC in patients affected with this condition and normal controls by using resting-state functional magnetic resonance imaging (fMRI). Methods: Structural and functional MRI data were obtained from 36 unilateral PT patients with single etiology and 36 matched healthy controls. FC feature of the region of interest (PCC) were characterized using a seed-based correlation method with the voxels in the whole-brain. Results: Compared with healthy controls, patients showed significant decreased FC to the right middle temporal gyrus (MTG), right thalamus and bilateral insula. By contrast, PCC demonstrated increased functional connectivity between the precuneus, bilateral inferior parietal lobule and middle occipital gyrus. We also found correlations between the disease duration of PT and FC of PCC-right MTG (r = −0.616, p < 0.001). Conclusions: Unilateral PT patients could have abnormal FC to the PCC bilaterally in the brain. PCC, as a highly integrated brain area, is an example of nucleus that was involved in mediation between different neural networks. It might be a modulation core between visual network and auditory network. The decreased FC of MTG to PCC may indicate a down regulation of activity between PCC and auditory associated brain cortex. Decreased FC between limbic system (bilateral AI) and PCC may reflect the emotional message control in patient group. This study facilitated understanding of the underlying neuropathological process in patients with pulsatile tinnitus.

Effects of Growth Hormone Replacement Therapy on Bone Mineral Density in Growth Hormone Deficient Adults: A Meta-Analysis

Directory of Open Access Journals (Sweden)

Peng Xue

2013-01-01

Full Text Available Objectives. Growth hormone deficiency patients exhibited reduced bone mineral density compared with healthy controls, but previous researches demonstrated uncertainty about the effect of growth hormone replacement therapy on bone in growth hormone deficient adults. The aim of this study was to determine whether the growth hormone replacement therapy could elevate bone mineral density in growth hormone deficient adults. Methods. In this meta-analysis, searches of Medline, Embase, and The Cochrane Library were undertaken to identify studies in humans of the association between growth hormone treatment and bone mineral density in growth hormone deficient adults. Random effects model was used for this meta-analysis. Results. A total of 20 studies (including one outlier study with 936 subjects were included in our research. We detected significant overall association of growth hormone treatment with increased bone mineral density of spine, femoral neck, and total body, but some results of subgroup analyses were not consistent with the overall analyses. Conclusions. Our meta-analysis suggested that growth hormone replacement therapy could have beneficial influence on bone mineral density in growth hormone deficient adults, but, in some subject populations, the influence was not evident.

Growth hormone stimulation test

Science.gov (United States)

... this page: //medlineplus.gov/ency/article/003377.htm Growth hormone stimulation test To use the sharing features on this page, please enable JavaScript. The growth hormone (GH) stimulation test measures the ability of ...

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

[Revelation of a polymicrocystic ovary syndrome after one month's treatment by pulsatile GnRH in a patient presenting with functional hypothalamic amenorrhea].

Science.gov (United States)

Reyss, A C; Merlen, E; Demerle, C; Dewailly, D

2003-12-01

Polycystic ovary syndrome (PCOS) and hypothalamic amenorrhea (HA) are the most frequent causes of endocrine infertility, but their association is an uncommon occurrence. We report the case of a 28-year old woman suffering from infertility and amenorrhea. Her weight was normal (BMI = 19) and she had no hirsutism. She self-reported food restriction and a 10 kg weight loss 5 years ago, concomitant with the onset of amenorrhea. At the initial evaluation, the patient was considered as having HA due to food restriction. At ultrasonography, ovaries were small and multifollicular (right and left area: 2.2 and 2.5 cm(2), respectively; number of cysts 2-9 mm in diameter: 15 and 12, respectively), and no stromal hypertrophy was noted. She has been treated for 1 month by intravenous pulsatile GnRH administration. Although the doses were increased from 5 to 15 microg/pulse every 90 min, no E2 response and no follicular development were observed. Hormonal re-evaluation revealed normal levels of serum LH, FSH and androgens, and a normal LH/FSH ratio. However, a typical aspect of PCO was found at ultrasound (right and left area: 6.5 and 5.5 cm(2), respectively, and more than 15 small cysts arranged peripherally around an increased central stroma in each ovary). The treatment has been then switched to hMG, using the low dose step-up regimen and starting with 75 U/day. In the absence of response after 2 weeks, the dose was increased to 112.5 U/day and a multifollicular reaction occurred, leading to cancellation. In conclusion, we hypothesize that this patient had a "hidden" PCOS when she was hypogonadotrophic and that it developed very rapidly after restitution of a normal gonadotropin level under exogenous GnRH. This occurred despite a low insulin level, showing that hyperinsulinism is not a prerequisite for the development of PCOS in every case.

Headache And Hormones

Directory of Open Access Journals (Sweden)

Shukla Rakesh

2002-01-01

Full Text Available There are many reasons to suggest a link between headache and hormones. Migraine is three times common in women as compared to men after puberty, cyclic as well as non-cyclic fluctuations in sex hormone levels during the entire reproductive life span of a women are associated with changes in frequency or severity of migraine attack, abnormalities in the hypothalamus and pineal gland have been observed in cluster headache, oestrogens are useful in the treatment of menstrual migraine and the use of melatonin has been reported in various types of primary headaches. Headache associated with various endocrinological disorders may help us in a better understanding of the nociceptive mechanisms involved in headache disorders. Prospective studies using headache diaries to record the attacks of headache and menstrual cycle have clarified some of the myths associated with menstrual migraine. Although no change in the absolute levels of sex hormones have been reported, oestrogen withdrawal is the most likely trigger of the attacks. Prostaglandins, melatonin, opioid and serotonergic mechanisms may also have a role in the pathogenesis of menstrual migraine. Guidelines have been published by the IHS recently regarding the use of oral contraceptives by women with migraine and the risk of ischaemic strokes in migraineurs on hormone replacement therapy. The present review includes menstrual migraine, pregnancy and migraine, oral contraceptives and migraine, menopause and migraine as well as the hormonal changes in chronic migraine.

Hormone therapy and ovarian borderline tumors

DEFF Research Database (Denmark)

Mørch, Lina Steinrud; Løkkegaard, Ellen; Andreasen, Anne Helms

2012-01-01

Little is known about the influence of postmenopausal hormone therapy on the risk of ovarian borderline tumors. We aimed at assessing the influence of different hormone therapies on this risk.......Little is known about the influence of postmenopausal hormone therapy on the risk of ovarian borderline tumors. We aimed at assessing the influence of different hormone therapies on this risk....

Association of Hormonal Contraception With Depression

DEFF Research Database (Denmark)

Skovlund, Charlotte Wessel; Mørch, Lina Steinrud; Kessing, Lars Vedel

2016-01-01

to those who never used hormonal contraception, the RR estimates for users of combined oral contraceptives increased to 1.7 (95% CI, 1.66-1.71). Conclusions and Relevance: Use of hormonal contraception, especially among adolescents, was associated with subsequent use of antidepressants and a first......Importance: Millions of women worldwide use hormonal contraception. Despite the clinical evidence of an influence of hormonal contraception on some women's mood, associations between the use of hormonal contraception and mood disturbances remain inadequately addressed. Objective: To investigate...... whether the use of hormonal contraception is positively associated with subsequent use of antidepressants and a diagnosis of depression at a psychiatric hospital. Design, Setting, and Participants: This nationwide prospective cohort study combined data from the National Prescription Register...

Response to three years of growth hormone therapy in girls with Turner syndrome

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Hong Kyu Park

2013-03-01

Full Text Available PurposeShort stature is the most common finding in patients with Turner syndrome. Improving the final adult height in these patients is a challenge both for the patients and physicians. We investigated the clinical response of patients to growth hormone treatment for height improvement over the period of three years.MethodsReview of medical records from 27 patients with Turner syndrome treated with recombinant human growth hormone for more than 3 years was done. Differences in the changes of height standard deviation scores according to karyotype were measured and factors influencing the height changes were analyzed.ResultsThe response to recombinant human growth hormone was an increase in the height of the subjects to a mean value of 1.1 standard deviation for subjects with Turner syndrome at the end of the 3-year treatment. The height increment in the first year was highest. The height standard deviation score in the third year was negatively correlated with the age at the beginning of the recombinant human growth hormone treatment. Different karyotypes in subjects did not seem to affect the height changes.ConclusionEarly growth hormone administration in subjects with Turner syndrome is helpful to improve height response to the treatment.

Effects of Growth Hormone Replacement Therapy on Bone Mineral Density in Growth Hormone Deficient Adults: A Meta-Analysis

OpenAIRE

Xue, Peng; Wang, Yan; Yang, Jie; Li, Yukun

2013-01-01

Objectives. Growth hormone deficiency patients exhibited reduced bone mineral density compared with healthy controls, but previous researches demonstrated uncertainty about the effect of growth hormone replacement therapy on bone in growth hormone deficient adults. The aim of this study was to determine whether the growth hormone replacement therapy could elevate bone mineral density in growth hormone deficient adults. Methods. In this meta-analysis, searches of Medline, Embase, and The Cochr...

Sex hormones in early infancy seem to predict aspects of later language development.

Science.gov (United States)

Schaadt, Gesa; Hesse, Volker; Friederici, Angela D

2015-02-01

Sex differences in the development of cognitive behavior such as language have long been of great research interest. Lately, researchers have started to associate language function and brain differences with diverse sex hormones (e.g., testosterone/estradiol). However, results concerning the impact of early postnatal sex hormone concentration on the child's later language development are rare. Here, we analyze the impact of testosterone and estradiol in girls and boys as well as their neurophysiological phonemic discrimination at age 5months on language development at age 4years. Interestingly, we found strong positive estradiol and negative testosterone impact on later language performance at age 4years, which was true for both girls and boys. These results demonstrate that postnatal sex hormone surge might be viewed as one factor determining later language development, independent of gender. Copyright © 2014 Elsevier Inc. All rights reserved.

Safety and efficacy of the Aperio thrombectomy device when compared to the Solitaire AB/FR and the Revive devices in a pulsatile flow system.

Science.gov (United States)

Saleh, Mahdi; Spence, John Nathan; Nayak, Sanjeev; Pearce, Gillian; Tennuci, Christopher; Roffe, Christine

2012-01-01

There are a limited number of studies comparing the Aperio mechanical thrombectomy device to other stent-based devices. In this paper, we compared the Aperio thrombectomy device to the Solitaire AB, FR and Revive devices in a model of the middle cerebral artery (MCA) within a modified pulsatile flow system. Thrombi made of lamb's blood were placed into a pulsatile flow system perfused with Hartmann's solution at 80 bpm with a mean pressure of 90 mm Hg. 30 experiments were run with each device. Recanalization rates were similar for all three devices (90% with the Solitaire AB, FR, 80% with the Revive, and 90% with the Aperio). The mean number of attempts to retrieve the thrombus was also similar for all three devices (1.7 with the Solitaire AB, FR, 2.1 with the Revive, 1.6 with the Aperio). Clot fragmentation and embolization rates revealed no statistical significance but there was a trend towards lower embolization rates with the Aperio (23% compared to 40% with the Solitaire AB, FR and 47% with the Revive). The Aperio was the fastest to recanalize the MCA (mean of 66 seconds compared to 186 seconds for the Solitaire AB, FR and 169 seconds for the Revive). In this in vitro setting, the Aperio device seems to be an efficacious and safe device when compared to other similar clinically used mechanical thrombectomy devices. Larger clinical trials are warranted.

Research resource: novel structural insights bridge gaps in glycoprotein hormone receptor analyses.

Science.gov (United States)

Kreuchwig, Annika; Kleinau, Gunnar; Krause, Gerd

2013-08-01

The first version of a glycoprotein hormone receptor (GPHR) information resource was designed to link functional with structural GPHR information, in order to support sequence-structure-function analysis of the LH, FSH, and TSH receptors (http://ssfa-gphr.de). However, structural information on a binding- and signaling-sensitive extracellular fragment (∼100 residues), the hinge region, had been lacking. A new FSHR crystal structure of the hormone-bound extracellular domain has recently been solved. The structure comprises the leucine-rich repeat domain and most parts of the hinge region. We have not only integrated the new FSHR/FSH structure and the derived homology models of TSHR/TSH, LHCGR/CG, and LHCGR/LH into our web-based information resource, but have additionally provided novel tools to analyze the advanced structural features, with the common characteristics and distinctions between GPHRs, in a more precise manner. The hinge region with its second hormone-binding site allows us to assign functional data to the new structural features between hormone and receptor, such as binding details of a sulfated tyrosine (conserved throughout the GPHRs) extending into a pocket of the hormone. We have also implemented a protein interface analysis tool that enables the identification and visualization of extracellular contact points between interaction partners. This provides a starting point for comparing the binding patterns of GPHRs. Together with the mutagenesis data stored in the database, this will help to decipher the essential residues for ligand recognition and the molecular mechanisms of signal transduction, extending from the extracellular hormone-binding site toward the intracellular G protein-binding sites.

Growth Hormone-Releasing Hormone in Diabetes

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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.

Changes in the Plasma Sex Hormone Profile in Males with Severe Concomitant Injury

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K. N Yezhova

2009-01-01

Full Text Available Objective: to perform a complex study of typical plasma sex hormone changes and their functional significance in males with severe concomitant injury (SCI. Subjects and methods. Fifty-nine males aged 18—49 years who had SCI were enrolled in the study. The admission severity was an APACHE II score of 18.6±2.4. According to the outcome of the disease, all the patients were divided into 2 groups: A survivors; B deceased persons. A control comprised 12 healthy male donors aged 19-36 years, in whom the levels of 8 sex steroids were measured. The standard procedures were used to comparatively analyze the concentrations of pituitary reproductive hormones and aldosterone. Hormonal concentrations were studied over time on posttraumatic days 1, 3, 5, 7, 10, and 15. The plasma hormone profile was examined by test kits (BSL, USA on a Stat Fax 2100 device (Awareness Technology Inc., USA for enzyme immunoassay. Prolactin, luteinizing hormone (LH, follicle-stimulating hormone (FSH, progesterone (P, 17-hydroxyprogesterone (17-OH-P, dehydroepiandrosterone sulfate (DHEA-S, androstendione (A, testosterone (T, dihydrotestosterone (DHT, estrone (E1, estradiol (E2, and aldosterone were determined. Results. The complex study of phasic changes in the profile of 11 plasma sex hormones was first conducted in males in the posttraumatic period. Moreover, the typical plasma hormonal changes were elevated prolactin levels and their phasic variations, normal LH and FSH levels with a tendency for further phasic LH changes and FSH reduction. After the injury, the plasma concentration of P was increased and that of 17-OH-P was decreased. The levels of A and DHEA-S varied in the normal range with a tendency for DHEA-S to be lower during the process. In the posttraumatic period, the plasma content of T and DHT was substantially reduced and that of E1 and E2 was increased. The deceased patients generally showed higher levels of A, DHEA-S, and estrogens as a reflection of

Radioimmunological determination of plasma testosterone, luteinizing hormone, folliculostimulating hormone and prolactin levels in patients with prostate cancer

International Nuclear Information System (INIS)

Milkov, V.; Maleeva, A.; Tsvetkov, M.; Visheva, N.

1986-01-01

The hormone levels were measured before and after hormonal therapy. Statistically significant changes in the levels of the hormones in this study were recognized (p<0,001) as a result of treatment with estrogen preparations. Plasma prolactin was raised before estrogen therapy (statistically significant rise, p<0,001), as compared to the levels in a control group of normal subjects. A mild tendency was observed toward its increase, depending on the duration of treatment. The results of this study show that control of the hormonal status of patients with prostate cancer may serve as reliable criterion in evaluating the effectiveness of hormonal therapy. The changes in prolactin levels are evidence of hormonal disbalance, which may be observed in these patients

Hormones and β-Agonists

NARCIS (Netherlands)

Ginkel, van L.A.; Bovee, T.F.H.; Blokland, M.H.; Sterk, S.S.; Smits, N.G.E.; Pleadin, Jelka; Vulić, Ana

2016-01-01

This chapter provides some updated information on contemporary methods for hormone and β-agonist analyses. It deals with the classical approaches for the effective detection and identification of exogenous hormones. The chapter examines specific problems related to control strategies for natural

Some theoretical aspects of hormone receptor determination

International Nuclear Information System (INIS)

Sluiter, W.J.

1981-01-01

Suitable antisera for determination of hormone receptors are not available for the majority of hormone receptors. Therefore, the determination of hormone receptors is mostly performed in terms of binding capacity for the appropriate hormone, using radioactive hormone labels. Some theoretical aspects of such a receptor determination are discussed including the length of incubation (total or unoccupied receptor concentration), single point or multiple point (Scatchard) analysis (regarding the influence of other specific binders), the correction procedure for non-specific binding and the influence of the circulating hormone level. (Auth.)

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

Pulsatile Flow and Transport of Blood past a Cylinder: Basic Transport for an Artificial Lung.

Science.gov (United States)

Zierenberg, Jennifer R.

2005-11-01

The fluid mechanics and transport for flow of blood past a single cylinder is investigated using CFD. This work refers to an artificial lung in which oxygen travels through fibers oriented perpendicularly to the incoming blood flow. A pulsatile blood flow was considered: Ux=U0[ 1+A( φt ) ], where Ux is the velocity far from the cylinder. The Casson equation was used to describe the shear thinning and yield stress properties of blood. The presence of hemoglobin (i.e. facilitated diffusion) was considered. We examined the effect of A, U0 and φ on the flow and transport by varying the dimensionless parameters: A; Reynolds number, Re; and Womersley parameter, α. Two different feed gases were considered: pure O2 and air. The flow and concentration fields were computed for Re = 5, 10, and 40, 0 transport is found to primarily depend on Re and to increase with increasing Re, α and decreasing A. The presence of hemoglobin increases mass transport. Supported by NIH HL69420, NSF Fellowship

Sex, hormones and neurogenesis in the hippocampus: hormonal modulation of neurogenesis and potential functional implications.

Science.gov (United States)

Galea, L A M; Wainwright, S R; Roes, M M; Duarte-Guterman, P; Chow, C; Hamson, D K

2013-11-01

The hippocampus is an area of the brain that undergoes dramatic plasticity in response to experience and hormone exposure. The hippocampus retains the ability to produce new neurones in most mammalian species and is a structure that is targeted in a number of neurodegenerative and neuropsychiatric diseases, many of which are influenced by both sex and sex hormone exposure. Intriguingly, gonadal and adrenal hormones affect the structure and function of the hippocampus differently in males and females. Adult neurogenesis in the hippocampus is regulated by both gonadal and adrenal hormones in a sex- and experience-dependent way. Sex differences in the effects of steroid hormones to modulate hippocampal plasticity should not be completely unexpected because the physiology of males and females is different, with the most notable difference being that females gestate and nurse the offspring. Furthermore, reproductive experience (i.e. pregnancy and mothering) results in permanent changes to the maternal brain, including the hippocampus. This review outlines the ability of gonadal and stress hormones to modulate multiple aspects of neurogenesis (cell proliferation and cell survival) in both male and female rodents. The function of adult neurogenesis in the hippocampus is linked to spatial memory and depression, and the present review provides early evidence of the functional links between the hormonal modulation of neurogenesis that may contribute to the regulation of cognition and stress. © 2013 British Society for Neuroendocrinology.

Would male hormonal contraceptives affect cardiovascular risk?

Directory of Open Access Journals (Sweden)

Michael Zitzmann

2018-01-01

Full Text Available The aim of hormonal male contraception is to prevent unintended pregnancies by suppressing spermatogenesis. Hormonal male contraception is based on the principle that exogenous administration of androgens and other hormones such as progestins suppress circulating gonadotropin concentrations, decreasing testicular Leydig cell and Sertoli cell activity and spermatogenesis. In order to achieve more complete suppression of circulating gonadotropins and spermatogenesis, a progestin has been added testosterone to the most recent efficacy trials of hormonal male contraceptives. This review focusses on the potential effects of male hormonal contraceptives on cardiovascular risk factors, lipids and body composition, mainly in the target group of younger to middle-aged men. Present data suggest that hormonal male contraception can be reasonably regarded as safe in terms of cardiovascular risk. However, as all trials have been relatively short (< 3 years, a final statement regarding the cardiovascular safety of hormonal male contraception, especially in long-term use, cannot be made. Older men with at high risk of cardiovascular event might not be good candidates for hormonal male contraception. The potential adverse effects of hormonal contraceptives on cardiovascular risk appear to depend greatly on the choice of the progestin in regimens for hormonal male contraceptives. In the development of prospective hormonal male contraception, data on longer-term cardiovascular safety will be essential.

Hormone Replacement Therapy and Your Heart

Science.gov (United States)

Hormone replacement therapy and your heart Are you taking — or considering — hormone therapy to treat bothersome menopausal symptoms? Understand ... you. By Mayo Clinic Staff Long-term hormone replacement therapy used to be routinely prescribed for postmenopausal ...

On the Evolution of Pulsatile Flow Subject to a Transverse Impulse Body Force

Science.gov (United States)

di Labbio, Giuseppe; Keshavarz-Motamed, Zahra; Kadem, Lyes

2014-11-01

In the event of an unexpected abrupt traffic stop or car accident, automotive passengers will experience an abrupt body deceleration. This may lead to tearing or dissection of the aortic wall known as Blunt Traumatic Aortic Rupture (BTAR). BTAR is the second leading cause of death in automotive accidents and, although quite frequent, the mechanisms leading to BTAR are still not clearly identified, particularly the contribution of the flow field. As such, this work is intended to provide a fundamental framework for the investigation of the flow contribution to BTAR. In this fundamental study, pulsatile flow in a three-dimensional, straight pipe of circular cross-section is subjected to a unidirectional, transverse, impulse body force applied on a strictly bounded volume of fluid. These models were simulated using the Computational Fluid Dynamics (CFD) software FLUENT. The evolution of fluid field characteristics was investigated during and after the application of the force. The application of the force significantly modified the flow field. The force induces a transverse pressure gradient causing the development of secondary flow structures that dissipate the energy added by the acceleration. Once the force ceases to act, these structures are carried downstream and gradually dissipate their excess energy.

Gastrointestinal Hormones Induced the Birth of Endocrinology.

Science.gov (United States)

Wabitsch, Martin

2017-01-01

The physiological studies by British physiologists William Maddock Bayliss and Ernest Henry Starling, at the beginning of the last century, demonstrated the existence of specific messenger molecules (hormones) circulating in the blood that regulate the organ function and physiological mechanisms. These findings led to the concept of endocrinology. The first 2 hormones were secretin, discovered in 1902, and gastrin, discovered in 1905. Both hormones that have been described are produced in the gut. This chapter summarizes the history around the discovery of these 2 hormones, which is perceived as the birth of endocrinology. It is noteworthy that after the discovery of these 2 gastrointestinal hormones, many other hormones were detected outside the gut, and thereafter gut hormones faded from both the clinical and scientific spotlight. Only recently, the clinical importance of the gut as the body's largest endocrine organ producing a large variety of hormones has been realized. Gastrointestinal hormones are essential regulators of metabolism, growth, development and behavior and are therefore the focus of a modern pediatric endocrinologist. © 2017 S. Karger AG, Basel.

Inner Ear Conductive Hearing Loss and Unilateral Pulsatile Tinnitus Associated with a Dural Arteriovenous Fistula: Case Based Review and Analysis of Relationship between Intracranial Vascular Abnormalities and Inner Ear Fluids

Directory of Open Access Journals (Sweden)

Ettore Cassandro

2015-01-01

Full Text Available While pulsatile tinnitus (PT and dural arteriovenous fistula (DAVF are not rarely associated, the finding of a conductive hearing loss (CHL in this clinical picture is unusual. Starting from a case of CHL and PT, diagnosed to be due to a DAVF, we analyzed relationship between intracranial vascular abnormalities and inner ear fluids. DAVF was treated with endovascular embolization. Following this, there was a dramatic recovery of PT and of CHL, confirming their cause-effect link with DAVF. We critically evaluated the papers reporting this association. This is the first case of CHL associated with PT and DAVF. We describe the most significant experiences and theories reported in literature, with a personal analysis about the possible relationship between vascular intracranial system and labyrinthine fluids. In conclusion, we believe that this association may be a challenge for otolaryngologists. So we suggest to consider the possibility of a DAVF or other AVMs when PT is associated with CHL, without alterations of tympanic membrane and middle ear tests.

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...

Development and optimization of press coated tablets of release engineered valsartan for pulsatile delivery.

Science.gov (United States)

Shah, Sunny; Patel, Romik; Soniwala, Moinuddin; Chavda, Jayant

2015-01-01

The present work is aimed to develop and optimize pulsatile delivery during dissolution of an improved formulation of valsartan to coordinate the drug release with circadian rhythm. Preliminary studies suggested that β cyclodextrin could improve the solubility of valsartan and showed AL type solubility curve. A 1:1 stoichiometric ratio of valsartan to β cyclodextrin was revealed from phase solubility studies and Job's plot. The prepared complex showed significantly better dissolution efficiency (p valsartan β cyclodextrin complex was significantly higher (p valsartan β cyclodextrin complex were subsequently prepared and application of the Plackett-Burman screening design revealed that HPMC K4M and EC showed significant effect on lag time. A 3(2) full factorial design was used to measure the response of HPMC K4M and EC on lag time and time taken for 90% drug release (T90). The optimized batch prepared according to the levels obtained from the desirability function had a lag time of 6 h and consisted of HPMC K4M:ethylcellulose in a 1:1.5 ratio with 180 mg of coating and revealed a close agreement between observed and predicted value (R(2 )= 0.9694).

The Relationship Between Pulsatile Flow Impingement and Intraluminal Thrombus Deposition in Abdominal Aortic Aneurysms.

Science.gov (United States)

Lozowy, Richard J; Kuhn, David C S; Ducas, Annie A; Boyd, April J

2017-03-01

Direct numerical simulations were performed on four patient-specific abdominal aortic aneurysm (AAA) geometries and the resulting pulsatile blood flow dynamics were compared to aneurysm shape and correlated with intraluminal thrombus (ILT) deposition. For three of the cases, turbulent vortex structures impinged/sheared along the anterior wall and along the posterior wall a zone of recirculating blood formed. Within the impingement region the AAA wall was devoid of ILT and remote to this region there was an accumulation of ILT. The high wall shear stress (WSS) caused by the impact of vortexes is thought to prevent the attachment of ILT. WSS from impingement is comparable to peak-systolic WSS in a normal-sized aorta and therefore may not damage the wall. Expansion occurred to a greater extent in the direction of jet impingement and the wall-normal force from the continuous impact of vortexes may contribute to expansion. It was shown that the impingement region has low oscillatory shear index (OSI) and recirculation zones can have either low or high OSI. No correlation could be identified between OSI and ILT deposition since different flow dynamics can have similar OSI values.

Headaches and Hormones: What's the Connection?

Science.gov (United States)

Headaches and hormones: What's the connection? Being female has some real health advantages, but not when it comes to headaches — particularly ... a relationship between headaches and hormonal changes. The hormones estrogen (ES-truh-jen) and progesterone (pro-JES- ...

Interactions between hormones and epilepsy.

Science.gov (United States)

Taubøll, Erik; Sveberg, Line; Svalheim, Sigrid

2015-05-01

There is a complex, bidirectional interdependence between sex steroid hormones and epilepsy; hormones affect seizures, while seizures affect hormones thereby disturbing reproductive endocrine function. Both female and male sex steroid hormones influence brain excitability. For the female sex steroid hormones, progesterone and its metabolites are anticonvulsant, while estrogens are mainly proconvulsant. The monthly fluctuations in hormone levels of estrogen and progesterone are the basis for catamenial epilepsy described elsewhere in this issue. Androgens are mainly anticonvulsant, but the effects are more varied, probably because of its metabolism to, among others, estradiol. The mechanisms for the effects of sex steroid hormones on brain excitability are related to both classical, intracellularly mediated effects, and non-classical membrane effects due to binding to membrane receptors. The latter are considered the most important in relation to epilepsy. The different sex steroids can also be further metabolized within the brain to different neurosteroids, which are even more potent with regard to their effect on excitability. Estrogens potentiate glutamate responses, primarily by potentiating NMDA receptor activity, but also by affecting GABA-ergic mechanisms and altering brain morphology by increasing dendritic spine density. Progesterone and its main metabolite 5α-pregnan-3α-ol-20-one (3α-5α-THP) act mainly to enhance postsynaptic GABA-ergic activity, while androgens enhance GABA-activated currents. Seizures and epileptic discharges also affect sex steroid hormones. There are close anatomical connections between the temporolimbic system and the hypothalamus controlling the endocrine system. Several studies have shown that epileptic activity, especially mediated through the amygdala, alters reproductive function, including reduced ovarian cyclicity in females and altered sex steroid hormone levels in both genders. Furthermore, there is an asymmetric

Three-component homeostasis control

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Xu, Jin; Hong, Hyunsuk; Jo, Junghyo

2014-03-01

Two reciprocal components seem to be sufficient to maintain a control variable constant. However, pancreatic islets adapt three components to control glucose homeostasis. They are α (secreting glucagon), β (insulin), and δ (somatostatin) cells. Glucagon and insulin are the reciprocal hormones for increasing and decreasing blood glucose levels, while the role of somatostatin is unknown. However, it has been known how each hormone affects other cell types. Based on the pulsatile hormone secretion and the cellular interactions, this system can be described as coupled oscillators. In particular, we used the Landau-Stuart model to consider both amplitudes and phases of hormone oscillations. We found that the presence of the third component, δ cell, was effective to resist under glucose perturbations, and to quickly return to the normal glucose level once perturbed. Our analysis suggested that three components are necessary for advanced homeostasis control.

Evaluation of the renal resistive index and pulsatility index in patients with pleural effusion by duplex Doppler ultrasonography.

Science.gov (United States)

Değirmenci, Nevbahar Akcar; Metintaş, Muzaffer; Atlanoglu, Sahinde; Yıldırım, Huseyin

2013-01-01

The aim of the study was to evaluate the renal resistive index (RI) and pulsatility index (PI) in patients with pleural effusion (PE). We studied the mean renal RI and PI in 50 patients with PE and 30 healthy volunteers by Doppler sonography. We grouped effusion as unilateral and bilateral. Statistical analysis was done by independent t test and correlation coefficient analysis. The mean RI/PI in healthy volunteers and in PE patients was 0.58/0.93 and 0.72/1.35, respectively. We observed a significantly higher RI and PI in patients when compared with healthy volunteers (all p effusion (0.74 or 1.55, respectively) (p > 0.05). Pleural effusion might result in increased renal impedance as seen in cirrhosis, which is a rather complicated pathophysiological process, without causing any morphological changes in kidneys.

Comparative description of the use of modern methods of hormonal contraception for women with excessive body mass

Directory of Open Access Journals (Sweden)

I. B. Gridina

2016-04-01

Full Text Available Maintenance of reproductive health of women with excessive weight is the actual problem of nowadays and is an important direction of modern medicine. Aim. To analyze the efficiency and acceptability of oral, іntravaginal and transdermal hormonal contraceptives among women with excessive body mass. Methods and results. The tolerability and ease of use of different types of hormonal contraception have been studied in 72 women with excessive body mass to determine the reliability and acceptability of modern hormonal contraceptives. It has been investigated that the effectiveness of hormonal contraceptives according to our data is 100%, none patient was registered with an unwanted pregnancy. The total subjective evaluation of all hormonal contraceptives use were positive: 78.6% of women with excessive body mass who used oral contraceptives, were satisfied with the chosen contraceptive method, 81,8% – were satisfied with intravaginal method, 59,1% – transdermal contraceptive. Conclusions. It has been found that intravaginal contraceptive is most suitable as the drug of first choice for women with overweight compared with oral and transdermal hormonal methods of contraception. This suggests that women with excessive body mass can successfully use modern methods of hormonal contraception. But it is necessary to carry out clinical supervision, during which further clarification on the use of hormonal contraception in women with excessive body mass is possible.

Parathyroid hormone-related protein blood test

Science.gov (United States)

... ency/article/003691.htm Parathyroid hormone-related protein blood test To use the sharing features on this page, ... measures the level of a hormone in the blood, called parathyroid hormone-related protein. How the Test is Performed A blood sample is needed . How ...

Thyroid hormone signaling in the hypothalamus

NARCIS (Netherlands)

Alkemade, Anneke; Visser, Theo J.; Fliers, Eric

2008-01-01

PURPOSE OF REVIEW: Proper thyroid hormone signaling is essential for brain development and adult brain function. Signaling can be disrupted at many levels due to altered thyroid hormone secretion, conversion or thyroid hormone receptor binding. RECENT FINDINGS: Mutated genes involved in thyroid

Obesity, growth hormone and weight loss

DEFF Research Database (Denmark)

Rasmussen, Michael Højby

2009-01-01

Growth hormone (GH) is the most important hormonal regulator of postnatal longitudinal growth in man. In adults GH is no longer needed for longitudinal growth. Adults with growth hormone deficiency (GHD) are characterised by perturbations in body composition, lipid metabolism, cardiovascular risk...

Hormone therapy and ovarian cancer

DEFF Research Database (Denmark)

Mørch, Lina Steinrud; Løkkegaard, Ellen; Andreasen, Anne Helms

2009-01-01

CONTEXT: Studies have suggested an increased risk of ovarian cancer among women taking postmenopausal hormone therapy. Data are sparse on the differential effects of formulations, regimens, and routes of administration. OBJECTIVE: To assess risk of ovarian cancer in perimenopausal and postmenopau......CONTEXT: Studies have suggested an increased risk of ovarian cancer among women taking postmenopausal hormone therapy. Data are sparse on the differential effects of formulations, regimens, and routes of administration. OBJECTIVE: To assess risk of ovarian cancer in perimenopausal...... and postmenopausal women receiving different hormone therapies. DESIGN AND SETTING: Nationwide prospective cohort study including all Danish women aged 50 through 79 years from 1995 through 2005 through individual linkage to Danish national registers. Redeemed prescription data from the National Register...... bands included hormone exposures as time-dependent covariates. PARTICIPANTS: A total of 909,946 women without hormone-sensitive cancer or bilateral oophorectomy. MAIN OUTCOME MEASURE: Ovarian cancer. RESULTS: In an average of 8.0 years of follow-up (7.3 million women-years), 3068 incident ovarian...

Bioidentical hormone therapy: Nova Scotia pharmacists’ knowledge and beliefs

OpenAIRE

Whelan, Anne Marie; Thebeau, Jean-Pierre; Jurgens, Tannis M.; Hurst, Eileen

2012-01-01

Objectives: To investigate Nova Scotia (NS) pharmacists´ knowledge and beliefs regarding the use of bioidentical hormones (BHs) for the management of menopause related symptoms. Methods: Using Dillman´s tailored design methodology, an invitation to complete the web-based questionnaire was emailed to pharmacists in NS as part of the Dalhousie College of Pharmacy Continuing Pharmacy Education Department´s (CPE) weekly email update. Data was analyzed using descriptive statistics. Results: Of app...

[Correlations between PBDEs and thyroid hormone concentrations in adults from production source area].

Science.gov (United States)

Li, Ming-Yuan; Jin, Jun; Yang, Cong-Qiao; Wang, Ying; Ding, Wen-Wei; Yang, Xian-Feng; Liu, An-Ming

2011-11-01

Polybrominated diphenyl ethers (PBDEs) concentrations in 36 resident serum samples from PBDEs production source area were analyzed by gas chromatography/negative chemical ionization/mass spectrometry(GC-NCI-MS) method, and the concentrations of thyroid hormones were determined as well. The sigma5PBDEs (BDE-28, -47, -153, -183, -209) concentrations(lipid weight) in serum ranged from 130.3 to 4 478.4 ng x g(-1), with an average value of 529.9 ng x g(-1). BDE-209 was a dominant PBDE congener, on average accounting for 69.8% of the total PBDEs concentrations. Spearman rank correlation coefficient was calculated between PBDEs and thyroid hormone, it showed that there were high significant negative correlation between BDE-28, -47, -153, -183 and thyroid-stimulating hormone (TSH), and significant negative correlation was also found between BDE-183 and free thyroxine (fT4). Additionally, there were significant positive correlation between BDE-28, -47 and triiodothyronine (T3), as well as between BDE-28, -153, -183 and free triiodothyronine(fT3). In summary, the concentrations of PBDEs in serum in this study were at a high level, and BDE-209 was the predominant congener. The exposure to the PBDEs may affect thyroid hormone levels, and the further research should focus on the relationship between PBDEs and thyroid hormone concentrations.

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...

In vitro binding of steroid hormones by natural and purified fibers

International Nuclear Information System (INIS)

Shultz, T.D.; Howie, B.J.

1986-01-01

The in vitro binding of estrone, estradiol-17β, estriol, testosterone, dihydrotestosterone, and estrone-3-glucuronide by wheat, oat and corn brans, oat hulls, cellulose, lignin, and cholestyramine resin was measured. Steroid binding was carried out by mixing 50 mg of binding substance with varying substrate quantities (0.037 μCi; 0.50-2.51 pmol/incubation) of 3 H-estrone, 3 H-estradiol-17β, 3 H-estriol, 3 H-estrone-3-glucuronide, 4 H-testosterone, and 370 C for 1 hr with shaking. Following centrifugation of the reaction mixture, a 1 ml aliquot was analyzed for radioactivity. The extent of steroid sequestration was characteristic and reproducible for each hormone. Cholestyramine bound an average of 90% of all the steroids tested, whereas cellulose bound the least (12%). Of the other substances tested, lignin bound 87%; wheat and oat grans, 45% each; corn bran, 44%; and oat hulls, 32% of the unconjugated hormones. The conjugated steroid was less likely to bind than the unconjugated steroids. Lignin appeared to be an important component in the interaction with steroid hormones. The results support the hydrophobic of nature of adsorption and suggest that the components of the fiber in diet should be considered separately when evaluating in vivo metabolic effects. Implications include the possible modification of hormone-dependent cancer risk through dietary intervention

Growth hormone-mediated breakdown of body fat

DEFF Research Database (Denmark)

Johansen, T.; Malmlöf, K.; Richelsen, Bjørn

2003-01-01

regimen. Twelve-month-old rats fed first a high-fat diet or a low-fat diet for 14 weeks were injected with saline or growth hormone (4 mg/kg/d) for four days or three weeks in different combinations with either high- or low-fat diets. In adipose tissue, growth hormone generally inhibited lipoprotein...... lipase and also attenuated the inhibiting effect of insulin on hormone-sensitive lipase activity. Growth hormone treatment combined with restricted high-fat feeding reduced the activity of both lipases in adipose tissue and stimulated hormone-sensitive lipase in muscle. Generally, plasma levels of free...... fatty acids, glycerol and cholesterol were reduced by growth hormone, and in combination with restricted high-fat feeding, triglyceride levels improved too. We conclude that growth hormone inhibits lipid storage in adipose tissue by reducing both lipoprotein lipase activity and insulin's inhibitory...

Thyroid and Cortisol hormones in Attention Deficit Hyperactivity Disorder: A case-control study.

Science.gov (United States)

Kuppili, Pooja Patnaik; Pattanayak, Raman Deep; Sagar, Rajesh; Mehta, Manju; Vivekanandhan, S

2017-08-01

There is paucity of research in the putative role of hormonal biomarkers in Attention Deficit Hyperactivity Disorder (ADHD). The current study aimed to analyze the clinical profile, socio-demographic status, co-morbidity, hormonal biomarkers namely Thyroid hormones and Cortisol in children with ADHD and compare them with healthy controls and to explore the association of the hormonal biomarkers with severity of ADHD. Thirty children with DSM-IV TR diagnosis of ADHD were assessed using semi structured proforma, Conners' Parent Rating Scale revised short (CPRS - R: S) , Mini international neuropsychiatric interview for children and adolescents and Childrens' Global Assessment Scale as well as serum levels of total Triiodothyronine (T3) ,total Thyroxine (T4) , Thyroid Stimulating Hormone (TSH) and Cortisol using chemiluminescent immunometric assay and compared with 30 age- and gender -matched controls. The typical profile of cases of ADHD was of a male with mean age of 9.47 years (S.D=2.43) belonging to Hyperactive subtype of ADHD. Serum T4 was significantly lower in cases compared to controls. No significant difference was found in serum T3, TSH and Cortisol levels. No significant correlation between the CPRS : R-S scores and the hormonal biomarkers. There is need for exploration of Serum T4 as putative biomarker for ADHD with replication in future studies. It may also be important to report the negative finding of Cortisol as a biomarker of ADHD in the context of effective utilization of resources for research with special relevance to resource deficit developing countries. Copyright © 2017 Elsevier B.V. All rights reserved.

Ovarian hormones and obesity.

Science.gov (United States)

Leeners, Brigitte; Geary, Nori; Tobler, Philippe N; Asarian, Lori

2017-05-01

Obesity is caused by an imbalance between energy intake, i.e. eating and energy expenditure (EE). Severe obesity is more prevalent in women than men worldwide, and obesity pathophysiology and the resultant obesity-related disease risks differ in women and men. The underlying mechanisms are largely unknown. Pre-clinical and clinical research indicate that ovarian hormones may play a major role. We systematically reviewed the clinical and pre-clinical literature on the effects of ovarian hormones on the physiology of adipose tissue (AT) and the regulation of AT mass by energy intake and EE. Articles in English indexed in PubMed through January 2016 were searched using keywords related to: (i) reproductive hormones, (ii) weight regulation and (iii) central nervous system. We sought to identify emerging research foci with clinical translational potential rather than to provide a comprehensive review. We find that estrogens play a leading role in the causes and consequences of female obesity. With respect to adiposity, estrogens synergize with AT genes to increase gluteofemoral subcutaneous AT mass and decrease central AT mass in reproductive-age women, which leads to protective cardiometabolic effects. Loss of estrogens after menopause, independent of aging, increases total AT mass and decreases lean body mass, so that there is little net effect on body weight. Menopause also partially reverses women's protective AT distribution. These effects can be counteracted by estrogen treatment. With respect to eating, increasing estrogen levels progressively decrease eating during the follicular and peri-ovulatory phases of the menstrual cycle. Progestin levels are associated with eating during the luteal phase, but there does not appear to be a causal relationship. Progestins may increase binge eating and eating stimulated by negative emotional states during the luteal phase. Pre-clinical research indicates that one mechanism for the pre-ovulatory decrease in eating is a

Generalized resistance to thyroid hormone associated with a mutation in the ligand-binding domain of the human thyroid hormone receptor β

International Nuclear Information System (INIS)

Sakurai, A.; Takeda, K.; Ain, K.; Ceccarelli, P.; Nakai, A.; Seino, S.; Bell, G.I.; Refetoff, S.; DeGroot, L.J.

1989-01-01

The syndrome of generalized resistance to thyroid hormone is characterized by elevated circulating levels of thyroid hormone in the presence of an overall eumetabolic state and failure to respond normally to triiodothyronine. The authors have evaluated a family with inherited generalized resistance to thyroid hormone for abnormalities in the thyroid hormone nuclear receptors. A single guanine → cytosine replacement in the codon for amino acid 340 resulted in a glycine → arginine substitution in the hormone-binding domain of one of two alleles of the patient's thyroid hormone nuclear receptor β gene. In vitro translation products of this mutant human thyroid hormone nuclear receptor β gene did not bind triiodothyronine. Thus, generalized resistance to thyroid hormone can result from expression of an abnormal thyroid hormone nuclear receptor molecule

Luteinizing hormone (LH) blood test

Science.gov (United States)

ICSH - blood test; Luteinizing hormone - blood test; Interstitial cell stimulating hormone - blood test ... to temporarily stop medicines that may affect the test results. Be sure to tell your provider about ...

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.'".

Investigation of pulsatile flowfield in healthy thoracic aorta models.

Science.gov (United States)

Wen, Chih-Yung; Yang, An-Shik; Tseng, Li-Yu; Chai, Jyh-Wen

2010-02-01

Cardiovascular disease is the primary cause of morbidity and mortality in the western world. Complex hemodynamics plays a critical role in the development of aortic dissection and atherosclerosis, as well as many other diseases. Since fundamental fluid mechanics are important for the understanding of the blood flow in the cardiovascular circulatory system of the human body aspects, a joint experimental and numerical study was conducted in this study to determine the distributions of wall shear stress and pressure and oscillatory WSS index, and to examine their correlation with the aortic disorders, especially dissection. Experimentally, the Phase-Contrast Magnetic Resonance Imaging (PC-MRI) method was used to acquire the true geometry of a normal human thoracic aorta, which was readily converted into a transparent thoracic aorta model by the rapid prototyping (RP) technique. The thoracic aorta model was then used in the in vitro experiments and computations. Simulations were performed using the computational fluid dynamic (CFD) code ACE+((R)) to determine flow characteristics of the three-dimensional, pulsatile, incompressible, and Newtonian fluid in the thoracic aorta model. The unsteady boundary conditions at the inlet and the outlet of the aortic flow were specified from the measured flowrate and pressure results during in vitro experiments. For the code validation, the predicted axial velocity reasonably agrees with the PC-MRI experimental data in the oblique sagittal plane of the thoracic aorta model. The thorough analyses of the thoracic aorta flow, WSSs, WSS index (OSI), and wall pressures are presented. The predicted locations of the maxima of WSS and the wall pressure can be then correlated with that of the thoracic aorta dissection, and thereby may lead to a useful biological significance. The numerical results also suggest that the effects of low WSS and high OSI tend to cause wall thickening occurred along the inferior wall of the aortic arch and the

Postmenopausal hormone replacement therapy--clinical implications

DEFF Research Database (Denmark)

Ravn, S H; Rosenberg, J; Bostofte, E

1994-01-01

The menopause is defined as cessation of menstruation, ending the fertile period. The hormonal changes are a decrease in progesterone level, followed by a marked decrease in estrogen production. Symptoms associated with these hormonal changes may advocate for hormonal replacement therapy....... This review is based on the English-language literature on the effect of estrogen therapy and estrogen plus progestin therapy on postmenopausal women. The advantages of hormone replacement therapy are regulation of dysfunctional uterine bleeding, relief of hot flushes, and prevention of atrophic changes...... in the urogenital tract. Women at risk of osteoporosis will benefit from hormone replacement therapy. The treatment should start as soon after menopause as possible and it is possible that it should be maintained for life. The treatment may be supplemented with extra calcium intake, vitamin D, and maybe calcitonin...

Hormone therapy and different ovarian cancers

DEFF Research Database (Denmark)

Mørch, Lina Steinrud; Løkkegaard, Ellen; Andreasen, Anne Helms

2012-01-01

Postmenopausal hormone therapy use increases the risk of ovarian cancer. In the present study, the authors examined the risks of different histologic types of ovarian cancer associated with hormone therapy. Using Danish national registers, the authors identified 909,946 women who were followed from...... 1995-2005. The women were 50-79 years of age and had no prior hormone-sensitive cancers or bilateral oophorectomy. Hormone therapy prescription data were obtained from the National Register of Medicinal Product Statistics. The National Cancer and Pathology Register provided data on ovarian cancers......, including information about tumor histology. The authors performed Poisson regression analyses that included hormone exposures and confounders as time-dependent covariates. In an average of 8.0 years of follow up, 2,681 cases of epithelial ovarian cancer were detected. Compared with never users, women...

Cerebral Pulsatility Index Is Elevated in Patients with Elevated Right Atrial Pressure.

Science.gov (United States)

Lahiri, Shouri; Schlick, Konrad H; Padrick, Matthew M; Rinsky, Brenda; Gonzalez, Nestor; Jones, Heather; Mayer, Stephan A; Lyden, Patrick D

2018-01-01

Extracerebral venous congestion can precipitate intracranial hypertension due to obstruction of cerebral blood outflow. Conditions that increase right atrial pressure, such as hypervolemia, are thought to increase resistance to jugular venous outflow and contribute to cerebro-venous congestion. Cerebral pulsatility index (CPI) is considered a surrogate marker of distal cerebrovascular resistance and is elevated with intracranial hypertension. Thus, we sought to test the hypothesis that elevated right atrial pressure is associated with increased CPI compared to normal right atrial pressure. We retrospectively reviewed 61 consecutive patients with subarachnoid hemorrhage. We calculated CPI from transcranial Doppler studies and correlated these with echocardiographic measures of right atrial pressure. CPIs were compared from patients with elevated and normal right atrial pressure. There was a significant difference between CPI obtained from all patients with elevated right atrial pressure compared to those with normal right atrial pressure (P right and left hemispheric CPI from patients with both elevated and normal right atrial pressure. Patients with elevated right atrial pressure had significantly higher CPI compared to patients with normal right atrial pressure. These findings suggest that cerebro-venous congestion due to impaired jugular venous outflow may increase distal cerebrovascular resistance as measured by CPI. Since elevated CPI is associated with poor outcome in numerous neurological conditions, future studies are needed to elucidate the significance of these results in other populations. Copyright © 2017 by the American Society of Neuroimaging.

Analysis of the effects of sex hormone background on the rat choroid plexus transcriptome by cDNA microarrays.

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Telma Quintela

Full Text Available The choroid plexus (CP are highly vascularized branched structures that protrude into the ventricles of the brain, and form a unique interface between the blood and the cerebrospinal fluid (CSF, the blood-CSF barrier, that are the main site of production and secretion of CSF. Sex hormones are widely recognized as neuroprotective agents against several neurodegenerative diseases, and the presence of sex hormones cognate receptors suggest that it may be a target for these hormones. In an effort to provide further insight into the neuroprotective mechanisms triggered by sex hormones we analyzed gene expression differences in the CP of female and male rats subjected to gonadectomy, using microarray technology. In gonadectomized female and male animals, 3045 genes were differentially expressed by 1.5-fold change, compared to sham controls. Analysis of the CP transcriptome showed that the top-five pathways significantly regulated by the sex hormone background are olfactory transduction, taste transduction, metabolism, steroid hormone biosynthesis and circadian rhythm pathways. These results represent the first overview of global expression changes in CP of female and male rats induced by gonadectomy and suggest that sex hormones are implicated in pathways with central roles in CP functions and CSF homeostasis.

Radioimmunoassay of steroid hormone

International Nuclear Information System (INIS)

Murakami, Tadashi

1975-01-01

Low acid pepsin treated gamma-globulin was applied to ammonium sulfate salting out method, which was a method to separate bound fraction from free one in radioimmunoassay of steroid hormone, and the effect of the separation and the standard curve were examined. Pepsin treated gamma-globulin was prepared in pH 1.5 to 5.5 and then the pepsin was completely removed. It had an effect to accelerate the precipitation in radioimmunoassay of steroid hormone labelled with 3 H. The effect of pepsin treated gamma-globulin to adhere free steroid hormone and to slat out bound one was compared with that of human gamma-globulin. Pepsin treated gamma-globulin, which was water soluble, could easier reach its optimal concentration, and the separation effect was better than human gamma-globulin. The standard curve of it was steeper, particularly in a small dose, and the reproducibility was also better. It could be applied not only to aldosterone and DOC, but also to the steroid hormones, such as progesterone and DHEA, and it seemed suitable for routine measurement method. (Kanao, N.)

Measurement of the incretin hormones

DEFF Research Database (Denmark)

Kuhre, Rune Ehrenreich; Wewer Albrechtsen, Nicolai Jacob; Hartmann, Bolette

2015-01-01

The two incretin hormones, glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP), are secreted from the gastrointestinal tract in response to meals and contribute to the regulation of glucose homeostasis by increasing insulin secretion. Assessment of plasma concentrat......The two incretin hormones, glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP), are secreted from the gastrointestinal tract in response to meals and contribute to the regulation of glucose homeostasis by increasing insulin secretion. Assessment of plasma...... concentrations of GLP-1 and GIP is often an important endpoint in both clinical and preclinical studies and, therefore, accurate measurement of these hormones is important. Here, we provide an overview of current approaches for the measurement of the incretin hormones, with particular focus on immunological...

Sex hormone-binding globulin as a marker for the thrombotic risk of hormonal contraceptives.

NARCIS (Netherlands)

Raps, M.; Helmerhorst, F.; Fleischer, K.; Thomassen, S.; Rosendaal, F.; Rosing, J.; Ballieux, B.; Vliet, H. van

2012-01-01

BACKGROUND: It takes many years to obtain reliable values for the risk of venous thrombosis of hormonal contraceptive users from clinical data. Measurement of activated protein C (APC) resistance via thrombin generation is a validated test for determining the thrombogenicity of hormonal

Not all elevated hormones are toxic: A case of thyroid hormone resistance

Directory of Open Access Journals (Sweden)

Rajeev Philip

2016-01-01

Full Text Available Resistance to thyroid hormone syndrome (RTH is a rare disorder and is usually inherited as dominantly negative autosomal trait. RTH is caused by mutations in the thyroid hormone receptor beta. Patients with RTH usually do not have signs and symptoms of thyrotoxicosis, but the thyroid function test shows an elevated T3 and T4, which get misinterpreted as hyperthyroidism, resulting in unnecessary treatment.

SHBG (Sex Hormone Binding Globulin)

Science.gov (United States)

... Links Patient Resources For Health Professionals Subscribe Search Sex Hormone Binding Globulin (SHBG) Send Us Your Feedback ... As Testosterone-estrogen Binding Globulin TeBG Formal Name Sex Hormone Binding Globulin This article was last reviewed ...

Hormone Therapy for Breast Cancer

Science.gov (United States)

... Common Cancer Types Recurrent Cancer Common Cancer Types Bladder Cancer Breast Cancer Colorectal Cancer Kidney (Renal Cell) Cancer ... sensitive breast cancer cells contain proteins called hormone receptors that become activated when hormones bind to them. ...

Salivary steroid hormone response to whole-body cryotherapy in elite rugby players.

Science.gov (United States)

Grasso, D; Lanteri, P; Di Bernardo, C; Mauri, C; Porcelli, S; Colombini, A; Zani, V; Bonomi, F G; Melegati, G; Banfi, G; Lombardi, G

2014-01-01

Saliva represents a low stress, not-invasively collected matrix that allows steroid hormone monitoring in athletes by reflecting type, intensity and duration of exercise. Whole body cryotherapy (WBC) consists of short whole-body exposures to extremely cold air (-110° to -140°C) which, despite being initially used to treat inflammatory diseases, is currently acquiring increasing popularity in sports medicine. Cryostimulation practice is now widely accepted as an effective treatment to accelerate muscle recovery in rugby players. The aim of this work was to study the changes of steroid hormones in saliva of rugby players after both 2 and 14 consecutive WBC sessions, in order to investigate the effects of the treatment on their salivary steroid hormonal profile. Twenty-five professional rugby players, belonging to the Italian National Team, underwent a 7-day cryotherapy protocol consisting of 2 daily sessions. Saliva samples were taken in the morning prior to the start of the WBC, in the evening after the end of the second WBC, and in the morning of the day after the last WBC session. The samples were analyzed for cortisol, DHEA, testosterone and estradiol using competitive enzyme-linked immunosorbent assays. Cortisol and DHEA showed a reduction already after the 2 WBC sessions of the first day; after 14 consecutive WBC sessions cortisol, DHEA, and estradiol levels decreased, while testosterone increased as did the testosterone to cortisol ratio. These results were confirmed by the fact that the majority of subjects showed variations exceeding the critical difference (CD). In conclusion, we found that WBC acutely affects the salivary steroid hormone profile, and the results are evident already after only one twice-daily session. Most significantly, after one-week of consecutive twice-daily WBC sessions, all the hormones were modified. This is the first experimental report that links changes in the hormonal asset to WBC.

Hormonal factors and incident asthma and allergic rhinitis during puberty in girls.

Science.gov (United States)

Wei, Junxiang; Gerlich, Jessica; Genuneit, Jon; Nowak, Dennis; Vogelberg, Christian; von Mutius, Erika; Radon, Katja

2015-07-01

Accumulating evidence is indicating that hormonal factors play a role in new-onset allergic rhinitis and asthma after puberty. To determine whether age at menarche and use of hormonal contraceptives predict new-onset allergic rhinitis and asthma after puberty in young German women. A prospective community-based cohort study followed 1,191 girls 9 to 11 years old to early adulthood (19-24 years old). Self-administrated questionnaires concerning age at menarche, use of hormonal contraceptives, and status and age at onset of physician-diagnosed allergic rhinitis and asthma were collected at 16 to 18 and 19 to 24 years of age. Logistic regression models were used to analyze the incidence of asthma and allergic rhinitis after puberty and pooled estimates were obtained from the final model. Eleven percent of girls developed allergic rhinitis after menarche and 3% reported new-onset asthma. Late menarche (>13 years of age) was statistically significantly inversely related to allergic rhinitis (adjusted odds ratio [OR] 0.32, 95% confidence interval [CI] 0.14-0.74) but did not reach the level of statistical significance for asthma (OR 0.32, 95% CI 0.07-1.42). Use of hormonal contraceptives was inversely associated with new-onset allergic rhinitis (OR 0.14, 95% CI 0.08-0.23) and asthma (OR 0.27, 95% CI 0.12-0.58) after puberty. This study shows that girls with late onset of menarche are less likely to develop allergic rhinitis after puberty compared with those who have menarche at an average age. These findings also suggest that, in addition to endogenous hormones, hormonal contraceptives play a role and might protect young women from allergies and asthma. Copyright © 2015 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Predicting the Probability of Abnormal Stimulated Growth Hormone Response in Children After Radiotherapy for Brain Tumors

International Nuclear Information System (INIS)

Hua Chiaho; Wu Shengjie; Chemaitilly, Wassim; Lukose, Renin C.; Merchant, Thomas E.

2012-01-01

Purpose: To develop a mathematical model utilizing more readily available measures than stimulation tests that identifies brain tumor survivors with high likelihood of abnormal growth hormone secretion after radiotherapy (RT), to avoid late recognition and a consequent delay in growth hormone replacement therapy. Methods and Materials: We analyzed 191 prospectively collected post-RT evaluations of peak growth hormone level (arginine tolerance/levodopa stimulation test), serum insulin-like growth factor 1 (IGF-1), IGF-binding protein 3, height, weight, growth velocity, and body mass index in 106 children and adolescents treated for ependymoma (n = 72), low-grade glioma (n = 28) or craniopharyngioma (n = 6), who had normal growth hormone levels before RT. Normal level in this study was defined as the peak growth hormone response to the stimulation test ≥7 ng/mL. Results: Independent predictor variables identified by multivariate logistic regression with high statistical significance (p < 0.0001) included IGF-1 z score, weight z score, and hypothalamic dose. The developed predictive model demonstrated a strong discriminatory power with an area under the receiver operating characteristic curve of 0.883. At a potential cutoff point of probability of 0.3 the sensitivity was 80% and specificity 78%. Conclusions: Without unpleasant and expensive frequent stimulation tests, our model provides a quantitative approach to closely follow the growth hormone secretory capacity of brain tumor survivors. It allows identification of high-risk children for subsequent confirmatory tests and in-depth workup for diagnosis of growth hormone deficiency.

High Fat High Sugar Diet Reduces Voluntary Wheel Running in Mice Independent of Sex Hormone Involvement

Science.gov (United States)

Vellers, Heather L.; Letsinger, Ayland C.; Walker, Nicholas R.; Granados, Jorge Z.; Lightfoot, J. Timothy

2017-01-01

Introduction: Indirect results in humans suggest that chronic overfeeding decreases physical activity with few suggestions regarding what mechanism(s) may link overfeeding and decreased activity. The primary sex hormones are known regulators of activity and there are reports that chronic overfeeding alters sex hormone levels. Thepurpose of this study was to determine if chronic overfeeding altered wheel running through altered sex hormone levels. Materials and Methods: C57BL/6J mice were bred and the pups were weaned at 3-weeks of age and randomly assigned to either a control (CFD) or high fat/high sugar (HFHS) diet for 9–11 weeks depending on activity analysis. Nutritional intake, body composition, sex hormone levels, and 3-day and 2-week wheel-running activity were measured. Additionally, groups of HFHS animals were supplemented with testosterone (males) and 17β-estradiol (females) to determine if sex hormone augmentation altered diet-induced changes in activity. Results: 117 mice (56♂, 61♀) were analyzed. The HFHS mice consumed significantly more calories per day than CFD mice (male: p running-wheel distance in male (p = 0.05, 70 ± 28%) and female mice (p = 0.02, 57 ± 26%). In animals that received hormone supplementation, there was no significant effect on activity levels. Two-weeks of wheel access was not sufficient to alter HFHS-induced reductions in activity or increases in body fat. Conclusion: Chronic overfeeding reduces wheel running, but is independent of the primary sex hormones. PMID:28890701

Predicting the Probability of Abnormal Stimulated Growth Hormone Response in Children After Radiotherapy for Brain Tumors

Energy Technology Data Exchange (ETDEWEB)

Hua Chiaho, E-mail: Chia-Ho.Hua@stjude.org [Department of Radiological Sciences, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Wu Shengjie [Department of Biostatistics, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Chemaitilly, Wassim [Division of Endocrinology, Department of Pediatric Medicine, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Lukose, Renin C.; Merchant, Thomas E. [Department of Radiological Sciences, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States)

2012-11-15

Purpose: To develop a mathematical model utilizing more readily available measures than stimulation tests that identifies brain tumor survivors with high likelihood of abnormal growth hormone secretion after radiotherapy (RT), to avoid late recognition and a consequent delay in growth hormone replacement therapy. Methods and Materials: We analyzed 191 prospectively collected post-RT evaluations of peak growth hormone level (arginine tolerance/levodopa stimulation test), serum insulin-like growth factor 1 (IGF-1), IGF-binding protein 3, height, weight, growth velocity, and body mass index in 106 children and adolescents treated for ependymoma (n = 72), low-grade glioma (n = 28) or craniopharyngioma (n = 6), who had normal growth hormone levels before RT. Normal level in this study was defined as the peak growth hormone response to the stimulation test {>=}7 ng/mL. Results: Independent predictor variables identified by multivariate logistic regression with high statistical significance (p < 0.0001) included IGF-1 z score, weight z score, and hypothalamic dose. The developed predictive model demonstrated a strong discriminatory power with an area under the receiver operating characteristic curve of 0.883. At a potential cutoff point of probability of 0.3 the sensitivity was 80% and specificity 78%. Conclusions: Without unpleasant and expensive frequent stimulation tests, our model provides a quantitative approach to closely follow the growth hormone secretory capacity of brain tumor survivors. It allows identification of high-risk children for subsequent confirmatory tests and in-depth workup for diagnosis of growth hormone deficiency.

Determination of the concentration of thyroid hormone in dialysate and assessment of the loss of thyroid hormone during hemodialysis

International Nuclear Information System (INIS)

Beyer, H.K.; Schuster, P.; Pressler, H.; Bochum Univ.

1980-01-01

In order to determine the hormone concentration in a dialysate, the commercially available radioimmunossay test of Dow-Lepetit for determination of free thyroid hormones in serum had to be modified. The results raised the suspicion that additional protein-bound hormone had passed the membrane. This could be demonstrated by the addition of Thiomersal. In 64 patients examined 1 and 5 hrs after the beginning of hemodialysis the mean total hormone concentration in the dialysate was 12.05 pg/ml for thyroxine and 5.47 pg/ml for triiodothyronine. The resulting loss of total hormone in hemodialysis patients, calculated for 1 week, amounted to 2.25 μg triiodothyronine and 4.87 μg thyroxine. The comparison with the physiologic renal elimination of thyroid hormone shows that the hormone elimination in hemodialysis patients is negligibly small. The quantitative determination of the protein concentration in the dialysate however, that the loss of protein is without clinical relevance. (orig.) [de

Sex hormones and skeletal muscle weakness

DEFF Research Database (Denmark)

Sipilä, Sarianna; Narici, Marco; Kjaer, Michael

2013-01-01

Human ageing is accompanied with deterioration in endocrine functions the most notable and well characterized of which being the decrease in the production of sex hormones. Current research literature suggests that low sex hormone concentration may be among the key mechanism for sarcopenia...... and muscle weakness. Within the European large scale MYOAGE project, the role of sex hormones, estrogens and testosterone, in causing the aging-related loss of muscle mass and function was further investigated. Hormone replacement therapy (HRT) in women is shown to diminish age-associated muscle loss, loss...... properties. HRT influences gene expression in e.g. cytoskeletal and cell-matrix proteins, has a stimulating effect upon IGF-I, and a role in IL-6 and adipokine regulation. Despite low circulating steroid-hormone level, postmenopausal women have a high local concentration of steroidogenic enzymes in skeletal...

Hormone Replacement Therapy: MedlinePlus Health Topic

Science.gov (United States)

... of hormone therapy (Medical Encyclopedia) Also in Spanish Topic Image MedlinePlus Email Updates Get Hormone Replacement Therapy ... Estrogen overdose Types of hormone therapy Related Health Topics Menopause National Institutes of Health The primary NIH ...

Increasing Goat Productivity Through the Improvement of Endogenous Secretion of Pregnant Hormones Using Follicle Stimulating Hormone

Directory of Open Access Journals (Sweden)

Andriyanto Andriyanto

2011-05-01

Full Text Available Abstract. Previous studies reported that the improvement of endogenous estrogen and progesterone secretions during gestation improved fetal prenatal growth, birth weight, mammary gland growth and development, milk production, litter size, pre- and post-weaning growths. An experiment was conducted to apply the improvement of endogenous secretion of pregnant hormones during pregnancy to increase goat productivity. Thirty-six female ettawah-cross does were divided into 2 groups. Group 1 (control: 18 does included does without improvement of endogenous secretion of pregnant hormones and Group 2 (treatment: 18 does included does with improvement of endogenous secretion of pregnant hormones using follicle stimulating hormones to stimulate super ovulation. The application of this technology increased total offspring born (control: 25 offspring; treatment: 42 offspring, average litter size (control: 1.88; treatment: 2.33, offspring birth weight (control: 2.85±0.50 kg; treatment: 3.82±0.40 kg, and does milk production (control: 1.36±0.34 L/does/day; treatment: 2.10±0.21 L/does/day. Offspring born to does with improved endogenous secretion of pregnant hormones had better weaning weight (control: 11.17±1.99 kg/offspring; treatment: 14.5±1.11 kg/offspring. At weaning period, does with improved endogenous secretion of pregnant hormones produced offspring with total weaning weight twice as heavy as control does (control: 189.9 kg; treatment: 403.6 kg. By a simple calculation of economic analysis, this technology application could increase gross revenue per does until weaning by Rp. 432.888,89. It was concluded that this technology is economically feasible to be applied in small-scale farm. Key Words: follicle stimulating hormone, pregnant hormones, endogenous secretion, super ovulation, ettawah-cross does

Structure-activity relationship of crustacean peptide hormones.

Science.gov (United States)

Katayama, Hidekazu

2016-01-01

In crustaceans, various physiological events, such as molting, vitellogenesis, and sex differentiation, are regulated by peptide hormones. To understanding the functional sites of these hormones, many structure-activity relationship (SAR) studies have been published. In this review, the author focuses the SAR of crustacean hyperglycemic hormone-family peptides and androgenic gland hormone and describes the detailed results of our and other research groups. The future perspectives will be also discussed.

Placental Transfer of Perfluoroalkyl Substances and Associations with Thyroid Hormones: Beijing Prenatal Exposure Study

Science.gov (United States)

Yang, Lin; Li, Jingguang; Lai, Jianqiang; Luan, Hemi; Cai, Zongwei; Wang, Yibaina; Zhao, Yunfeng; Wu, Yongning

2016-02-01

Perfluoroalkyl substances (PFASs) have been detected in wildlife and human samples worldwide. Toxicology research showed that PFASs could interfere with thyroid hormone homeostasis. In this study, eight PFASs, fifteen PFAS precursors and five thyroid hormones were analyzed in 157 paired maternal and cord serum samples collected in Beijing around delivery. Seven PFASs and two precursors were detected in both maternal and cord sera with significant maternal-fetal correlations (r = 0.336 to 0.806, all P < 0.001). The median ratios of major PFASs concentrations in fetal versus maternal serum were from 0.25:1 (perfluorodecanoic acid, PFDA) to 0.65:1 (perfluorooctanoic acid, PFOA). Spearman partial correlation test showed that maternal thyroid stimulating hormone (TSH) was negatively correlated with most maternal PFASs (r = -0.261 to -0.170, all P < 0.05). Maternal triiodothyronin (T3) and free T3 (FT3) showed negative correlations with most fetal PFASs (r = -0.229 to -0.165 for T3; r = -0.293 to -0.169 for FT3, all P < 0.05). Our results suggest prenatal exposure of fetus to PFASs and potential associations between PFASs and thyroid hormone homeostasis in humans.

Network identification of hormonal regulation.

Directory of Open Access Journals (Sweden)

Daniel J Vis

Full Text Available Relations among hormone serum concentrations are complex and depend on various factors, including gender, age, body mass index, diurnal rhythms and secretion stochastics. Therefore, endocrine deviations from healthy homeostasis are not easily detected or understood. A generic method is presented for detecting regulatory relations between hormones. This is demonstrated with a cohort of obese women, who underwent blood sampling at 10 minute intervals for 24-hours. The cohort was treated with bromocriptine in an attempt to clarify how hormone relations change by treatment. The detected regulatory relations are summarized in a network graph and treatment-induced changes in the relations are determined. The proposed method identifies many relations, including well-known ones. Ultimately, the method provides ways to improve the description and understanding of normal hormonal relations and deviations caused by disease or treatment.

Sex Hormones and Ischemic Stroke

DEFF Research Database (Denmark)

Holmegard, Haya N; Nordestgaard, Børge G; Jensen, Gorm B

2016-01-01

CONTEXT AND OBJECTIVE: Whether endogenous sex hormones are associated with ischemic stroke (IS) is unclear. We tested the hypothesis that extreme concentrations of endogenous sex hormones are associated with risk of IS in the general population. DESIGN, SETTING, AND PARTICIPANTS: Adult men (n...... = 4615) and women (n = 4724) with measurements of endogenous sex hormones during the 1981-1983 examination of the Copenhagen City Heart Study, Denmark, were followed for up to 29 years for incident IS, with no loss to follow-up. Mediation analyses assessed whether risk of IS was mediated through...

Radioimmunoassay of thyroid hormones

International Nuclear Information System (INIS)

Bartalena, L.; Mariotti, S.; Pinchera, A.

1987-01-01

For many years, methods based on iodine content determination have represented the only techniques available for the estimation of total thyroid hormone concentrations in serum. Subsequently, simple, sensitive, and specific radioligand assays for thyroid hormones have replaced these chemical methods. For the purpose of this chapter, iodometric techniques are only briefly summarized for their historical importance, whereas attention is focused on radioligand assays

Free thyroid hormones in health and disease

International Nuclear Information System (INIS)

Bueber, V.

1984-01-01

Several groups of patients with normal and abnormal thyroid function as well as patients with goitre on hormone substitution are discussed with respect to the diagnostic value of the free thyroid hormone methods. The free T 3 technique under investigation separates clearly between euthyroidism and hyperthyroidism, however, during application of contraceptive pills and during pregnancy free T 3 is slightly enhanced. Free T 4 can be found in the normal range even in hypothyroidism, during T 4 substitution free T 4 is useful for control of adequate hormone substitution. Free thyroid hormones are advantageous to be performed with respect to practicability compared to the estimation of total hormone concentrations by enzyme as well as radioimmunoassay. Normally there is no additional demand for measurement of thyroid hormone binding proteins, another rather economical argument for using these parameters in thyroid diagnosis. (orig.) [de

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.)

Incretin hormone secretion over the day

DEFF Research Database (Denmark)

Ahren, B; Carr, RD; Deacon, Carolyn F.

2010-01-01

The two incretin hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are key factors in the regulation of islet function and glucose metabolism, and incretin-based therapy for type 2 diabetes has gained considerable interest during recent years. Regulat......The two incretin hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are key factors in the regulation of islet function and glucose metabolism, and incretin-based therapy for type 2 diabetes has gained considerable interest during recent years....... Regulation of incretin hormone secretion is less well characterized. The main stimulus for incretin hormone secretion is presence of nutrients in the intestinal lumen, and carbohydrate, fat as well as protein all have the capacity to stimulate GIP and GLP-1 secretion. More recently, it has been established...... that a diurnal regulation exists with incretin hormone secretion to an identical meal being greater when the meal is served in the morning compared to in the afternoon. Finally, whether incretin hormone secretion is altered in disease states is an area with, so far, controversial results in different studies...

Quality of life in children and adolescents with growth hormone deficiency: association with growth hormone treatment.

Science.gov (United States)

Geisler, Alexandra; Lass, Nina; Reinsch, Nicole; Uysal, Yvonne; Singer, Viola; Ravens-Sieberer, Ulrike; Reinehr, Thomas

2012-01-01

Quality of life (QoL) as it is related with growth hormone deficiency (GHD) is a matter of controversy. We analyzed QoL in 95 children aged 8-18 years with isolated GHD (72% male) treated with growth hormone (GH). These children were compared to 190 age- and gender-matched healthy children with similar height [height children of normal stature (control group 2: CG2). QoL was measured by the KINDL® questionnaire referring to six domains (physical well-being, emotional well-being, self-esteem, family, friends, and school). QoL was significantly reduced in CG1 (effect-size 0.21) compared to CG2, while QoL was not significantly altered in children with GHD. In multiple linear regression analyses adjusted to age, gender, BMI, migration background, and socioeconomic status, decreasing height-SDS was associated with poorer QoL (especially emotional well-being), and treatment with GH was related significantly to better self-esteem. Increase of height-SDS in children treated with GH was associated positively with QoL and all its subscales except family and school. These findings suggest psychological consequences of short stature in children and an improvement of QoL in children treated with GH with the focus on self-esteem and emotional well-being. Copyright © 2012 S. Karger AG, Basel.

Growth hormone-specific induction of the nuclear localization of porcine growth hormone receptor in porcine hepatocytes.

Science.gov (United States)

Lan, H N; Hong, P; Li, R N; Shan, A S; Zheng, X

2017-10-01

The phenomenon of nuclear translocation of growth hormone receptor (GHR) in human, rat, and fish has been reported. To date, this phenomenon has not been described in a domestic animal (such as pig). In addition, the molecular mechanisms of GHR nuclear translocation have not been thoroughly elucidated. To this end, porcine hepatocytes were isolated and used as a cell model. We observed that porcine growth hormone (pGH) can induce porcine GHR's nuclear localization in porcine hepatocytes. Subsequently, the dynamics of pGH-induced pGHR's nuclear localization were analyzed and demonstrated that pGHR's nuclear localization occurs in a time-dependent manner. Next, we explored the mechanism of pGHR nuclear localization using different pGHR ligands, and we demonstrated that pGHR's nuclear translocation is GH(s)-dependent. We also observed that pGHR translocates into cell nuclei in a pGH dimerization-dependent fashion, whereas further experiments indicated that IMPα/β is involved in the nuclear translocation of the pGH-pGHR dimer. The pGH-pGHR dimer may form a pGH-GHR-JAK2 multiple complex in cell nuclei, which would suggest that similar to its function in the cell membrane, the nuclear-localized pGH-pGHR dimer might still have the ability to signal. Copyright © 2017 Elsevier Inc. All rights reserved.

Sex hormone binding globulin, free estradiol index, and lipid profiles in girls with precocious puberty

Directory of Open Access Journals (Sweden)

Hyun-Wook Chae

2013-06-01

Full Text Available PurposeSex hormone-binding globulin (SHBG modulates the availability of biologically active free sex hormones. The regulatory role of SHBG might be important in the relationship between hormone levels and the modification of lipid profiles in girls with precocious puberty. However, few studies have evaluated the relationship of SHBG, free estradiol index (FEI, and lipid levels in these girls.MethodsOne hundred and nine girls less than 8 years of age with pubertal development were enrolled. FEI was calculated with SHBG and estradiol (E2. We analyzed SHBG between peak luteinizing hormone (LH≥5 (IU/L (group 1 and LH<5 (IU/L (group 2 through a gonadotropin releasing hormone stimulation test.ResultsBody mass index (BMI standard deviation score (SDS was higher in group 2 than in group 1 (P=0.004. Serum SHBG levels did not differ and FEI was not higher in group 1 (P=0.122. Serum cholesterol, HDL, and LDL did not differ; however, triglyceride levels were higher in group 2 (P=0.023. SHBG was negatively correlated with bone age advancement, BMI, BMI SDS, and FEI, and was positively correlated with HDL. However, SHBG was not correlated with E2 or peak LH.ConclusionSerum SHBG itself might not be associated with precocious puberty in girls, but it might be related to BMI and lipid profiles. Further studies are needed to reveal the relationship between sex hormone and obesity in girls with precocious puberty.

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

Effects of hormones on platelet aggregation.

Science.gov (United States)

Farré, Antonio López; Modrego, Javier; Zamorano-León, José J

2014-04-01

Platelets and their activation/inhibition mechanisms play a central role in haemostasis. It is well known agonists and antagonists of platelet activation; however, during the last years novel evidences of hormone effects on platelet activation have been reported. Platelet functionality may be modulated by the interaction between different hormones and their platelet receptors, contributing to sex differences in platelet function and even in platelet-mediated vascular damage. It has suggested aspects that apparently are well established should be reviewed. Hormones effects on platelet activity are included among them. This article tries to review knowledge about the involvement of hormones in platelet biology and activity.

Influence of Acidification on the Partitioning of Steroid Hormones among Filtrate, Filter Media, and Retained Particulate Matter.

Science.gov (United States)

Havens, Sonya M; Hedman, Curtis J; Hemming, Jocelyn D C; Mieritz, Mark G; Shafer, Martin M; Schauer, James J

2016-09-01

Hormone contamination of aquatic systems has been shown to have deleterious effects on aquatic biota. However, the assessment of hormone contamination of aquatic environments requires a quantitative evaluation of the potential effects of sample preservation on hormone concentrations. This study investigated the influence of acidification (pH 2) of surface water samples on the partitioning of hormones among filtrate, filter media, and filter-retained particulate matter. Hormones were spiked into unpreserved and sulfuric acid-preserved ultrapure water and surface water runoff samples. The samples were filtered, and hormones were extracted from the filter and filtrate and analyzed by high-performance liquid chromatography. Acidification did not influence the partitioning of hormones onto the filter media. For the majority of the hormones investigated in this study, the partitioning of hormones to the filter-retained particulate matter was not influenced by acidification. Acidification increased the partitioning of progesterone and melengestrol acetate onto the retained particulate matter (about 25% for both analytes). Incorporation of an isotopically labeled internal standard (ISTD) for progesterone accounted for the loss of progesterone to the filter-retained particulates and resulted in accurate concentrations of progesterone in the filtrate. The incorporation of an ISTD for melengestrol acetate, however, was unable to account for the loss of melengestrol acetate to the retained particulates and resulted in underestimations of melengestrol acetate in the filtrate. Our results indicate that the analysis of melengestrol acetate in acid preserved surface runoff samples should be conducted on the filter-retained particulates as well as the filtrate. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Development of additional pituitary hormone deficiencies in pediatric patients originally diagnosed with idiopathic isolated GH deficiency

NARCIS (Netherlands)

W.F. Blum (Werner); C.L. Deal (Cheri Lynn); A.G. Zimmermann (Alan); E.P. Shavrikova (Elena); C.J. Child (Christopher); C.A. Quigley (Charmian); S.L.S. Drop (Stenvert); G. Cutler (Gordon); R.G. Rosenfeld (Ron)

2014-01-01

textabstractObjective: We assessed the characteristics of children initially diagnosed with idiopathic isolated GH deficiency (IGHD) who later developed additional (multiple) pituitary hormone deficiencies (MPHD). Design: Data were analyzed for 5805 pediatric patients with idiopathic IGHD, who were

Stress and hormones

Directory of Open Access Journals (Sweden)

Salam Ranabir

2011-01-01

Full Text Available In the modern environment one is exposed to various stressful conditions. Stress can lead to changes in the serum level of many hormones including glucocorticoids, catecholamines, growth hormone and prolactin. Some of these changes are necessary for the fight or flight response to protect oneself. Some of these stressful responses can lead to endocrine disorders like Graves′ disease, gonadal dysfunction, psychosexual dwarfism and obesity. Stress can also alter the clinical status of many preexisting endocrine disorders such as precipitation of adrenal crisis and thyroid storm.

Thyroid hormone and the central control of homeostasis.

Science.gov (United States)

Warner, Amy; Mittag, Jens

2012-08-01

It has long been known that thyroid hormone has profound direct effects on metabolism and cardiovascular function. More recently, it was shown that the hormone also modulates these systems by actions on the central autonomic control. Recent studies that either manipulated thyroid hormone signalling in anatomical areas of the brain or analysed seasonal models with an endogenous fluctuation in hypothalamic thyroid hormone levels revealed that the hormone controls energy turnover. However, most of these studies did not progress beyond the level of anatomical nuclei; thus, the neuronal substrates as well as the molecular mechanisms remain largely enigmatic. This review summarises the evidence for a role of thyroid hormone in the central autonomic control of peripheral homeostasis and advocates novel strategies to address thyroid hormone action in the brain on a cellular level.

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.

[Serum hormones that regulate the reproductive axis in men with testicular germ cell cancer and its impact on fertility].

Science.gov (United States)

Tovar-Rodríguez, José María; Chávez-Zúñiga, Irma; Bañuelos-Ávila, Leticia; Vargas-Hernández, Víctor Manuel; Acosta-Altamirano, Gustavo

2014-01-01

Epidemiological studies treat testicular germ cancer as a single disease, the behavior of the two histological types of cancer; seminoma and nonseminoma have differences in reproductive hormone secretion and impair fertility differently. To demonstrate that the serum concentration of pituitary hormones involved in fertility and spermatogenesis in the affected male is different in the two histological types. Were determined by radioimmunoassay or inmunoradiometric assay, luteinizing hormone, follicle stimulating hormone, total testosterone, prolactin, estradiol, human chorionic gonadotropin and alpha fetoprotein in 37 patients with germ cell cancer (15 seminoma and 22 nonseminoma) and 35 controls. We analyzed the semen of patients, and were questioned about paternity before the cancer diagnosis. Age was higher in patients with seminoma cancer, showed decreased luteinizing hormone, follicle stimulating hormone, and testosterone and increased estradiol and prolactin in nonseminoma compared with seminoma. In patients with nonseminoma they had 9 children, 5 were oligozoospermic, 3 azoospermic and 6 normal concentration, 8 did not provide sample, seminoma group they had eight children, only one azoospermic, nine normal concentration, and 5 did not provide sample . The hormonal behavior is different in men with nonseminoma compared with seminoma, so that the negative impact on the reproductive axis and fertility is higher in cases of non-seminoma.

SnapShot: Hormones of the gastrointestinal tract.

Science.gov (United States)

Coate, Katie C; Kliewer, Steven A; Mangelsdorf, David J

2014-12-04

Specialized endocrine cells secrete a variety of peptide hormones all along the gastrointestinal (GI) tract, making it one of the largest endocrine organs in the body. Nutrients and developmental and neural cues trigger the secretion of gastrointestinal (GI) hormones from specialized endocrine cells along the GI tract. These hormones act in target tissues to facilitate digestion and regulate energy homeostasis. This SnapShot summarizes the production and functions of GI hormones. Copyright © 2014 Elsevier Inc. All rights reserved.

Hormone abuse in sports: the antidoping perspective.

Science.gov (United States)

Barroso, Osquel; Mazzoni, Irene; Rabin, Olivier

2008-05-01

Since ancient times, unethical athletes have attempted to gain an unfair competitive advantage through the use of doping substances. A list of doping substances and methods banned in sports is published yearly by the World Anti-Doping Agency (WADA). A substance or method might be included in the List if it fulfills at least two of the following criteria: enhances sports performance; represents a risk to the athlete's health; or violates the spirit of sports. This list, constantly updated to reflect new developments in the pharmaceutical industry as well as doping trends, enumerates the drug types and methods prohibited in and out of competition. Among the substances included are steroidal and peptide hormones and their modulators, stimulants, glucocorticosteroids, beta2-agonists, diuretics and masking agents, narcotics, and cannabinoids. Blood doping, tampering, infusions, and gene doping are examples of prohibited methods indicated on the List. From all these, hormones constitute by far the highest number of adverse analytical findings reported by antidoping laboratories. Although to date most are due to anabolic steroids, the advent of molecular biology techniques has made recombinant peptide hormones readily available. These substances are gradually changing the landscape of doping trends. Peptide hormones like erythropoietin (EPO), human growth hormone (hGH), insulin, and insulin-like growth factor I (IGF-I) are presumed to be widely abused for performance enhancement. Furthermore, as there is a paucity of techniques suitable for their detection, peptide hormones are all the more attractive to dishonest athletes. This article will overview the use of hormones as doping substances in sports, focusing mainly on peptide hormones as they represent a pressing challenge to the current fight against doping. Hormones and hormones modulators being developed by the pharmaceutical industry, which could emerge as new doping substances, are also discussed. 2008, Asian

Control of Pituitary Thyroid-stimulating Hormone Synthesis and Secretion by Thyroid Hormones during Xenopus Metamorphosis

Science.gov (United States)

Serum thyroid hormone (TH) concentrations in anuran larvae rise rapidly during metamorphosis. Such a rise in an adult anuran would inevitably trigger a negative feedback response resulting in decreased synthesis and secretion of thyroid-stimulating hormone (TSH) by the pituitary....

Hormonal evaluation of T{sub 4} and T{sub 3} through radioimmunoassay in younglings of rats with hypothyroidism; Avaliacao hormonal de T{sub 4} e T{sub 3} atraves de radioimunoensaio em filhotes de ratas hipotireoideas

Energy Technology Data Exchange (ETDEWEB)

Silveira, M.F.G. [Pernambuco Univ., Recife, PE (Brazil). Dept. de Biofisica e Radiobiologia; Silva, I.M.S.; Pereira, S.S.L.; Souza, G.M.L.; Carvalho, E.F.M.B.; Cavalcante, C.V.G. [Pernambuco Univ., Recife, PE (Brazil). Dept. de Anatomia; Lima Filho, G.L.; Catanho, M.T.J.A. [Faculdade de Formacao de Professores de Nazare da Mata, PE (Brazil). Dept. de Ciencias Naturais

2000-07-01

The onset of fetal thyroid function occurs about 17-18 days after conception in the rat. The maternal hypothyroidism which occurs during gestation provokes alteration in the rat after birth. Due to this alteration, we decided to analyze the hormonal modification in the newborn rats. The hypothyroidism was induced in normal dams, which were being treated for 7 days with MMI (in the concentration of 0,03% in drinking water) before mating. Another dam group which was submitted to an induction of hypothyroidism maintained the treatment with MMI for 13 days during gestation. The hormones were assessed by radioimmunoassay technique. It was seen that the rats which were born from hypothyroid dams suffered alterations on its T{sub 4} and T{sub 3} hormone levels concerning to 10, 30 and 60 days after birth. There was also modifications on their weight and size. The growth is affected throughout post-natal life by thyroid hormones, which has a facilitator influence on growth hormone economy, as opposed to the inhibitory effects on TSH economy. The administration of MMI bars the fetal thyroid gland function, causing a decrease of both T{sub 4} and T{sub 3} levels, even after the birth, indicating that the maternal hypothyroidism influences on the post-natal life of the rat. (author)

Thyroid hormones and fetal brain development.

Science.gov (United States)

Pemberton, H N; Franklyn, J A; Kilby, M D

2005-08-01

Thyroid hormones are intricately involved in the developing fetal brain. The fetal central nervous system is sensitive to the maternal thyroid status. Critical amounts of maternal T3 and T4 must be transported across the placenta to the fetus to ensure the correct development of the brain throughout ontogeny. Severe mental retardation of the child can occur due to compromised iodine intake or thyroid disease. This has been reported in areas of the world with iodine insufficiency, New Guinea, and also in mother with thyroid complications such as hypothyroxinaemia and hyperthyroidism. The molecular control of thyroid hormones by deiodinases for the activation of thyroid hormones is critical to ensure the correct amount of active thyroid hormones are temporally supplied to the fetus. These hormones provide timing signals for the induction of programmes for differentiation and maturation at specific stages of development. Understanding these molecular mechanisms further will have profound implications in the clinical management of individuals affected by abnormal maternal of fetal thyroid status.

The barrier within: endothelial transport of hormones.

Science.gov (United States)

Kolka, Cathryn M; Bergman, Richard N

2012-08-01

Hormones are involved in a plethora of processes including development and growth, metabolism, mood, and immune responses. These essential functions are dependent on the ability of the hormone to access its target tissue. In the case of endocrine hormones that are transported through the blood, this often means that the endothelium must be crossed. Many studies have shown that the concentrations of hormones and nutrients in blood can be very different from those surrounding the cells on the tissue side of the blood vessel endothelium, suggesting that transport across this barrier can be rate limiting for hormone action. This transport can be regulated by altering the surface area of the blood vessel available for diffusion through to the underlying tissue or by the permeability of the endothelium. Many hormones are known to directly or indirectly affect the endothelial barrier, thus affecting their own distribution to their target tissues. Dysfunction of the endothelial barrier is found in many diseases, particularly those associated with the metabolic syndrome. The interrelatedness of hormones may help to explain why the cluster of diseases in the metabolic syndrome occur together so frequently and suggests that treating the endothelium may ameliorate defects in more than one disease. Here, we review the structure and function of the endothelium, its contribution to the function of hormones, and its involvement in disease.

Desensitization of parathyroid hormone receptors on cultured bone cells

International Nuclear Information System (INIS)

Pun, K.K.; Ho, P.W.; Nissenson, R.A.; Arnaud, C.D.

1990-01-01

Administration of excessive amounts of parathyroid hormone (PTH) in the treatment of osteoporosis can reverse the beneficial effects of a low-dose, intermittent regime. To investigate the direct actions and the possible cellular mechanisms of PTH in inducing desensitization of PTH receptors, we studied the effects of desensitization on rat osteoblastic UMR-106 cells. When the osteoblasts were preincubated with bPTH-(1-34), complete refractoriness to a subsequent challenge with the hormone developed within 1 h and at hormone concentrations as low as 5 nM. When osteoblasts thus desensitized were incubated in hormone-free medium, recovery of the cAMP responses began within 2 h and reached maximum after 16 h. Cycloheximide did not affect the process of desensitization. [Nle8,Nle18,Tyr34]bPTH-(3-34)amide significantly impaired the desensitization process by PTH-(1-34) but did not have stimulatory effect on cAMP responses. No significant heterologous desensitization was obvious after preincubation with isoprenaline (50 microM), prostaglandin E1 (50 microM), or prostaglandin E2 (50 microM) for 2 h. Binding experiments with [125I]PLP-(1-36)amide after desensitization revealed that there was an approximate twofold decrease in receptor affinities as analyzed by Scatchard analysis, showing that the decrease in affinity was prominent in the process of desensitization. When the cells were treated with monensin during desensitization, PTH challenge after desensitization produced significantly lower cyclic AMP responses. Recovery after desensitization occurred over a period of 16 h. Inclusion of monensin, but not cycloheximide, impaired the recovery. The results show that homologous desensitization of rat osteoblasts to PTH is brought about by the occupancy of receptors by PTH-(1-34) but not by cAMP generation itself

Basic study of intrinsic elastography: Relationship between tissue stiffness and propagation velocity of deformation induced by pulsatile flow

Science.gov (United States)

Nagaoka, Ryo; Iwasaki, Ryosuke; Arakawa, Mototaka; Kobayashi, Kazuto; Yoshizawa, Shin; Umemura, Shin-ichiro; Saijo, Yoshifumi

2015-07-01

We proposed an estimation method for a tissue stiffness from deformations induced by arterial pulsation, and named this proposed method intrinsic elastography (IE). In IE, assuming that the velocity of the deformation propagation in tissues is closely related to the stiffness, the propagation velocity (PV) was estimated by spatial compound ultrasound imaging with a high temporal resolution of 1 ms. However, the relationship between tissue stiffness and PV has not been revealed yet. In this study, the PV of the deformation induced by the pulsatile pump was measured by IE in three different poly(vinyl alcohol) (PVA) phantoms of different stiffnesses. The measured PV was compared with the shear wave velocity (SWV) measured by shear wave imaging (SWI). The measured PV has trends similar to the measured SWV. These results obtained by IE in a healthy male show the possibility that the mechanical properties of living tissues could be evaluated by IE.

Genetic polymorphisms and protein structures in growth hormone, growth hormone receptor, ghrelin, insulin-like growth factor 1 and leptin in Mehraban sheep.

Science.gov (United States)

Bahrami, A; Behzadi, Sh; Miraei-Ashtiani, S R; Roh, S-G; Katoh, K

2013-09-15

The somatotropic axis, the control system for growth hormone (GH) secretion and its endogenous factors involved in the regulation of metabolism and energy partitioning, has promising potentials for producing economically valuable traits in farm animals. Here we investigated single nucleotide polymorphisms (SNPs) of the genes of factors involved in the somatotropic axis for growth hormone (GH1), growth hormone receptor (GHR), ghrelin (GHRL), insulin-like growth factor 1 (IGF-I) and leptin (LEP), using polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) and DNA sequencing methods in 452 individual Mehraban sheep. A nonradioactive method to allow SSCP detection was used for genomic DNA and PCR amplification of six fragments: exons 4 and 5 of GH1; exon 10 of GH receptor (GHR); exon 1 of ghrelin (GHRL); exon 1 of insulin-like growth factor-I (IGF-I), and exon 3 of leptin (LEP). Polymorphisms were detected in five of the six PCR products. Two electrophoretic patterns were detected for GH1 exon 4. Five conformational patterns were detected for GH1 exon 5 and LEP exon 3, and three for IGF-I exon 1. Only GHR and GHRL were monomorphic. Changes in protein structures due to variable SNPs were also analyzed. The results suggest that Mehraban sheep, a major breed that is important for the animal industry in Middle East countries, has high genetic variability, opening interesting prospects for future selection programs and preservation strategies. Copyright © 2013 Elsevier B.V. All rights reserved.

[Dynamics of hormone secretion during chronic emotional stress].

Science.gov (United States)

Amiragova, M G; Kovalev, S V; Svirskaia, R I

1979-05-01

Study of spontaneous secretion of corticosteroids and thyroid hormones and the direct hormonal response to stress revealed the pathogenic effect of chronic combined emotional stress upon the hormonal function of adrenal glands. The hippocampus takes part in formation of the emotional tension in response to stress stimulus and of the following hormonal secretion.

Effect of radiation on proteo-hormones activity

International Nuclear Information System (INIS)

Mikulaj, L.

1975-05-01

Samples of pituitary hormones were irradiated by a 60 Co source. A dose rate of 1.0-1.1 Mrad/hour and the doses of 0.5, 2.5 and 12.5 Mrad were used. The hormone preparations in the dry solid state or in solution were sealed into glass ampules. After sterilization they were kept at 4 0 C until the biological activity had been tested. The biological activity of thyroid stimulating hormone TSH, subjected to a sterilizing dose of 2.5 Mrad of gamma radiation, was found to have decreased when tested 3-5 months after irradiation. TSH remained fully active for up to 1 month after sterilization. The activity of vasopressin dropped off markedly during the 3-4 week period after irradiation. Biological activity of growth hormone tested shortly after irradiation was found to be unaffected. The activities of adrenocorticotropic hormone, human menopausal gonadotropin and luteinizing hormone were not affected. The experiments can be considered promising since they show that pituitary proteohorm, one preparations in the solid state may be sterilized. The stability on storage needs, however, to be carefully checked individually for every single hormone

Mammographic changes in postmenopausal women : comparative effects between continuous combined hormone and single estrogen replacement therapy

Energy Technology Data Exchange (ETDEWEB)

Oh, Sug; Choi, Jong Tae; Jung, Kyoon Soon; Jung, Seung Hye [Jeil Women' s Hospital, Seoul (Korea, Republic of)

1997-06-01

As the use of hormone replacement therapy for the menopausal women increases, some caution is advised, since there is an increased risk of breast cancer. Accordingly, the importance of regular mammography has been addressed. This cross-setional study analyzed the effects of different hormone therapies on mammographic density. Sixty-seven postemenopausal women who had completed one year of hormone therapy and had undergone follow-up mammography, were divided into two groups : Group I : continuous conjugated equine estrogen, 0.625mg, plus continuous medroxyprogesterone acetate, 2.5mg (n=48), Group II : continuous conjugated equine estrogen 0.625mg (n=19). The mammograms were read by two radiologists. With regard to the radiologists involved, interobserver reliabillity (kappa) was 0.70 and intraobserver reliability (kappa) was 0.51 and 0.67. Before hormone therapy, factors related to decreased mammographic density were age and number of full term pregnancies (p<0.05). After one year of hormone therapy, body fat showed a significant increase (p<0.05), but in spite of this, increased mammographic density induced by hormone therapy remained significantly high (p<0.05). Compared with Group II, Group I showed a significant increase in mammographic density (p<0.05). In Group I, mammographic density increased from P2 to DY pattern in two cases, but there was no such change in Group II. The increase of mammographic density seen in Group II was much more significant statistically than that seen in Group I. The mammograms of women who have undergone continuous combined hormone therapy should therefore be interpreted very cautiously.

Mammographic changes in postmenopausal women : comparative effects between continuous combined hormone and single estrogen replacement therapy

International Nuclear Information System (INIS)

Oh, Sug; Choi, Jong Tae; Jung, Kyoon Soon; Jung, Seung Hye

1997-01-01

As the use of hormone replacement therapy for the menopausal women increases, some caution is advised, since there is an increased risk of breast cancer. Accordingly, the importance of regular mammography has been addressed. This cross-setional study analyzed the effects of different hormone therapies on mammographic density. Sixty-seven postemenopausal women who had completed one year of hormone therapy and had undergone follow-up mammography, were divided into two groups : Group I : continuous conjugated equine estrogen, 0.625mg, plus continuous medroxyprogesterone acetate, 2.5mg (n=48), Group II : continuous conjugated equine estrogen 0.625mg (n=19). The mammograms were read by two radiologists. With regard to the radiologists involved, interobserver reliabillity (kappa) was 0.70 and intraobserver reliability (kappa) was 0.51 and 0.67. Before hormone therapy, factors related to decreased mammographic density were age and number of full term pregnancies (p<0.05). After one year of hormone therapy, body fat showed a significant increase (p<0.05), but in spite of this, increased mammographic density induced by hormone therapy remained significantly high (p<0.05). Compared with Group II, Group I showed a significant increase in mammographic density (p<0.05). In Group I, mammographic density increased from P2 to DY pattern in two cases, but there was no such change in Group II. The increase of mammographic density seen in Group II was much more significant statistically than that seen in Group I. The mammograms of women who have undergone continuous combined hormone therapy should therefore be interpreted very cautiously

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.

Development of a method for comprehensive and quantitative analysis of plant hormones by highly sensitive nanoflow liquid chromatography-electrospray ionization-ion trap mass spectrometry

International Nuclear Information System (INIS)

Izumi, Yoshihiro; Okazawa, Atsushi; Bamba, Takeshi; Kobayashi, Akio; Fukusaki, Eiichiro

2009-01-01

In recent plant hormone research, there is an increased demand for a highly sensitive and comprehensive analytical approach to elucidate the hormonal signaling networks, functions, and dynamics. We have demonstrated the high sensitivity of a comprehensive and quantitative analytical method developed with nanoflow liquid chromatography-electrospray ionization-ion trap mass spectrometry (LC-ESI-IT-MS/MS) under multiple-reaction monitoring (MRM) in plant hormone profiling. Unlabeled and deuterium-labeled isotopomers of four classes of plant hormones and their derivatives, auxins, cytokinins (CK), abscisic acid (ABA), and gibberellins (GA), were analyzed by this method. The optimized nanoflow-LC-ESI-IT-MS/MS method showed ca. 5-10-fold greater sensitivity than capillary-LC-ESI-IT-MS/MS, and the detection limits (S/N = 3) of several plant hormones were in the sub-fmol range. The results showed excellent linearity (R 2 values of 0.9937-1.0000) and reproducibility of elution times (relative standard deviations, RSDs, <1.1%) and peak areas (RSDs, <10.7%) for all target compounds. Further, sample purification using Oasis HLB and Oasis MCX cartridges significantly decreased the ion-suppressing effects of biological matrix as compared to the purification using only Oasis HLB cartridge. The optimized nanoflow-LC-ESI-IT-MS/MS method was successfully used to analyze endogenous plant hormones in Arabidopsis and tobacco samples. The samples used in this analysis were extracted from only 17 tobacco dry seeds (1 mg DW), indicating that the efficiency of analysis of endogenous plant hormones strongly depends on the detection sensitivity of the method. Our analytical approach will be useful for in-depth studies on complex plant hormonal metabolism.

Development of a method for comprehensive and quantitative analysis of plant hormones by highly sensitive nanoflow liquid chromatography-electrospray ionization-ion trap mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

Izumi, Yoshihiro; Okazawa, Atsushi; Bamba, Takeshi; Kobayashi, Akio [Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan); Fukusaki, Eiichiro, E-mail: fukusaki@bio.eng.osaka-u.ac.jp [Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan)

2009-08-26

In recent plant hormone research, there is an increased demand for a highly sensitive and comprehensive analytical approach to elucidate the hormonal signaling networks, functions, and dynamics. We have demonstrated the high sensitivity of a comprehensive and quantitative analytical method developed with nanoflow liquid chromatography-electrospray ionization-ion trap mass spectrometry (LC-ESI-IT-MS/MS) under multiple-reaction monitoring (MRM) in plant hormone profiling. Unlabeled and deuterium-labeled isotopomers of four classes of plant hormones and their derivatives, auxins, cytokinins (CK), abscisic acid (ABA), and gibberellins (GA), were analyzed by this method. The optimized nanoflow-LC-ESI-IT-MS/MS method showed ca. 5-10-fold greater sensitivity than capillary-LC-ESI-IT-MS/MS, and the detection limits (S/N = 3) of several plant hormones were in the sub-fmol range. The results showed excellent linearity (R{sup 2} values of 0.9937-1.0000) and reproducibility of elution times (relative standard deviations, RSDs, <1.1%) and peak areas (RSDs, <10.7%) for all target compounds. Further, sample purification using Oasis HLB and Oasis MCX cartridges significantly decreased the ion-suppressing effects of biological matrix as compared to the purification using only Oasis HLB cartridge. The optimized nanoflow-LC-ESI-IT-MS/MS method was successfully used to analyze endogenous plant hormones in Arabidopsis and tobacco samples. The samples used in this analysis were extracted from only 17 tobacco dry seeds (1 mg DW), indicating that the efficiency of analysis of endogenous plant hormones strongly depends on the detection sensitivity of the method. Our analytical approach will be useful for in-depth studies on complex plant hormonal metabolism.

Molecular mechanisms of regulation of growth hormone gene expression in cultured rat pituitary cells by thyroid and glucocorticoid hormones

International Nuclear Information System (INIS)

Yaffe, B.M.

1989-01-01

In cultured GC cells, a rat pituitary tumor cell line, growth hormone [GH] is induced in a synergistic fashion by physiologic concentrations of thyroid and glucocorticoid hormones. Abundant evidence indicates that these hormones mediate this response via their specific receptors. The purpose of this thesis is to explore the mechanisms by which these hormones affect GH production. When poly (A) + RNA was isolated from cells grown both with and without hormones and translated in a cell-free wheat germ system, the preGH translation products were shown to be proportional to immunoassayable GH production under all combinations of hormonal milieux, indicating that changes in GH production is modulated at a pretranslational level. A cDNA library was constructed from poly (A) + RNA and one clone containing GH cDNA sequences was isolated. This was used to confirm the above results by Northern dot blot analysis. This probe was also used to assess hormonal effects on GH mRNA half-life and synthetic rates as well as GH gene transcription rates in isolated nuclei. Using a pulse-chase protocol in which cellular RNA was labeled in vivo with [ 3 H]uridine, and quantitating [ 3 H]GHmRNA directly by hybridization to GH cDNA bound to nitrocellulose filters, GHmRNA was found to have a half-life of approximately 50 hours, and was not significantly altered by the presence of inducing hormones

Effect of nutritional rehabilitation on acquired growth hormone resistance in malnourished children using radioisotopic technique

International Nuclear Information System (INIS)

El-Nabarawy, F.S.; Nour Eldin, A.M.

2003-01-01

The present study was undertaken to clarify the influence of nutrition on growth hormone resistance in children who were suffering from prologed protein energy malnutrition (PEM). The plasma levels of glucose and serum levels of insulin, free triiodothyronine (FT 3 ), free teraiodothyronine (FT 4 ), thyroid stimulating hormone (TSH), growth hormone (GH), insulin-like growth factor-1 (IGF-1) and insulin like growth factor binding protein-3 (IGFBP-3) were analyzed by radioisotopic techniques in 7 children with marasmus (mean age 5.29 1.01) and 14 children with unexplained short stature (stunted) (mean age 6.21 1.72) before and after nutritional rehabilitation. At the basal condition of laboratory investigations, the GH level was significantly higher in the two malnourished groups compared to control (P< 0.01), whereas, plasma glucose levels and insulin concentrations did not differ significantly between the two malnourished groups and the control

Effect of sex hormones on bone density during growth

International Nuclear Information System (INIS)

Gilsanz, V.; Roe, T.F.; Wells, T.R.; Senac, M.O. Jr.; Landing, B.; Libaneti, C.; Cann, C.E.; Schulz, E.

1986-01-01

The development of special phantoms permitted precise measurement of vertebral mineral content by CT in the very young. The normal standards for spinal trabecular bone of children aged 0-18 years are presented. Although there is no age-related difference in bone density before puberty, there is a significant increase in bone mineral content after puberty. The increase in sex hormones during puberty accounts for the increased density. Longitudinal studies analyzing vertebral density changes in castrated rabbits after testosterone and estradiol administration are discussed

Increased pulsatility index supports diagnosis of vascular parkinsonism versus idiopathic Parkinson's disease.

Science.gov (United States)

Caba, L M; Ferrairó, J I T; Torres, I M; Costa, J F V; Muñoz, R B; Martin, A L

2017-12-29

The diagnosis of vascular parkinsonism (VP) is based on a series of clinical criteria and neuroimaging findings. An increase in transcranial Doppler ultrasonography pulsatility index (PI) has been described as a frequent finding in patients with VP. We aimed to confirm this association and to determine the PI value with the highest sensitivity and specificity for diagnosis of VP. PI was determined in all patients admitted to Hospital Universitari i Politècnic La Fe due to parkinsonism between January 2012 and June 2016. We assessed the probability of having VP based on PI values in patients with a definite diagnosis of either VP or idiopathic Parkinson's disease (IPD). A ROC curve was created to determine the PI value with the highest sensitivity and specificity. We assessed a total of 146 patients with suspected parkinsonism; 54 (37%) were diagnosed with IPD and 15 (10%) with VP. Patients with VP were significantly older than those with IPD (mean age of 79 vs 68.5, P=.00144) and had a higher PI (median of 1.29 [IQR: 1.09-1.38] vs 0.96 [IQR: 0.89-1.16], P=.01328). In our sample, a PI of 1.09 conferred 84% sensitivity and 70% specificity. In our series, the PI was significantly higher in patients with VP than in those with IPD. We therefore support the use of transcranial Doppler ultrasonography for the initial assessment of elderly patients with akinetic-rigid syndrome. Copyright © 2017 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

Thyroid hormone analogs for the treatment of dyslipidemia: past, present, and future.

Science.gov (United States)

Delitala, Alessandro P; Delitala, Giuseppe; Sioni, Paolo; Fanciulli, Giuseppe

2017-11-01

Treatment of dyslipidemia is a major burden for public health. Thyroid hormone regulates lipid metabolism by binding the thyroid hormone receptor (TR), but the use of thyroid hormone to treat dyslipidemia is not indicated due to its deleterious effects on heart, bone, and muscle. Thyroid hormone analogs have been conceived to selectively activate TR in the liver, thus reducing potential side-effects. The authors searched the PubMed database to review TR and the action of thyromimetics in vitro and in animal models. Then, all double-blind, placebo controlled trials that analyzed the use of thyroid hormone analog for the treatment of dyslipidemia in humans were included. Finally, the ongoing research on the use of TR agonists was searched, searching the US National Institutes of Health Registry and the WHO International Clinical Trial Registry Platform (ICTRP). Thyromimetics were tested in humans for the treatment of dyslipidemia, as a single therapeutic agent or as an add-on therapy to the traditional lipid-lowering drugs. In most trials, thyromimetics lowered total cholesterol, low-density lipoprotein cholesterol, and triglycerides, but their use has been associated with adverse side-effects, both in pre-clinical studies and in humans. The use of thyromimetics for the treatment of dyslipidemia is not presently recommended. Future possible clinical applications might include their use to promote weight reduction. Thyromimetics might also represent an interesting alternative, both for the treatment of non-alcoholic steatohepatitis, and type 2 diabetes due to their positive effects on insulin sensitivity. Finally, additional experimental and clinical studies are needed for a better comprehension of the effect(s) of a long-term therapy.

High-performance liquid chromatography of human glycoprotein hormones.

Science.gov (United States)

Chlenov, M A; Kandyba, E I; Nagornaya, L V; Orlova, I L; Volgin, Y V

1993-02-12

The chromatographic behavior of the glycoprotein hormones from human pituitary glands and of placental origin [thyroid-stimulating hormone, luteinizing hormone and chorionic gonadotropin (CG)] was studied. It was shown that hydrophobic interaction chromatography on a microparticulate packing and anion-exchange HPLC can be applied for the purification of these hormones. Reversed-phase HPLC on wide-pore C4-bonded silica at neutral pH can be applied for the determination of the above hormones and for the isolation of pure CG and its subunits.

Controversies in hormone replacement therapy

Directory of Open Access Journals (Sweden)

A. Baziad

2001-09-01

Full Text Available Deficiency of estrogen hormone will result in either long-term or short-term health problems which may reduce the quality of life. There are numerous methods by which the quality of female life can be achieved. Since the problems occuring are due to the deficiency of estrogen hormone, the appropriate method to tackle the problem is by administration of estrogen hormone. The administration of hormone replacement therapy (HRT with estrogen may eliminate climacteric complaints, prevent osteoporosis, coronary heart disease, dementia, and colon cancer. Although HRT has a great deal of advantage, its use is still low and may result in controversies. These controversies are due to fact that both doctor and patient still hold on to the old, outmoded views which are not supported by numerous studies. Currently, the use of HRT is not only based on experience, or temporary observation, but more on evidence based medicine. (Med J Indones 2001; 10: 182-6Keywords: controversies, HRT

Hormone Data

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Hormones quantified from marine mammal and sea turtle tissue provide information about the status of each animal sampled, including its sex, reproductive status and...

Hormonal evaluation of T4 and T3 through radioimmunoassay in younglings of rats with hypothyroidism

International Nuclear Information System (INIS)

Silveira, M.F.G.; Silva, I.M.S.; Pereira, S.S.L.; Souza, G.M.L.; Carvalho, E.F.M.B.; Cavalcante, C.V.G.; Lima Filho, G.L.; Catanho, M.T.J.A.

2000-01-01

The onset of fetal thyroid function occurs about 17-18 days after conception in the rat. The maternal hypothyroidism which occurs during gestation provokes alteration in the rat after birth. Due to this alteration, we decided to analyze the hormonal modification in the newborn rats. The hypothyroidism was induced in normal dams, which were being treated for 7 days with MMI (in the concentration of 0,03% in drinking water) before mating. Another dam group which was submitted to an induction of hypothyroidism maintained the treatment with MMI for 13 days during gestation. The hormones were assessed by radioimmunoassay technique. It was seen that the rats which were born from hypothyroid dams suffered alterations on its T 4 and T 3 hormone levels concerning to 10, 30 and 60 days after birth. There was also modifications on their weight and size. The growth is affected throughout post-natal life by thyroid hormones, which has a facilitator influence on growth hormone economy, as opposed to the inhibitory effects on TSH economy. The administration of MMI bars the fetal thyroid gland function, causing a decrease of both T 4 and T 3 levels, even after the birth, indicating that the maternal hypothyroidism influences on the post-natal life of the rat. (author)

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...

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.

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

UV filters induce transcriptional changes of different hormonal receptors in Chironomus riparius embryos and larvae.

Science.gov (United States)

Ozáez, Irene; Aquilino, Mónica; Morcillo, Gloria; Martínez-Guitarte, José-Luis

2016-07-01

Organic ultraviolet (UV) filters are emerging contaminants that are ubiquitous in fresh and marine aquatic systems due to their extensive use in cosmetics, plastics, paints, textiles, and many other industrial products. The estrogenic effects of organic UV filters have been long demonstrated in vertebrates, and other hormonal activities may be altered, according to more recent reports. The impact of UV filters on the endocrine system of invertebrates is largely unknown. We have previously reported that some UV filters may affect ecdysone-related genes in the aquatic insect Chironomus riparius, an ecotoxicologically important model organism. To further analyze other possible effects on endocrine pathways, we first characterized four pivotal genes related with hormonal pathways in insects; thereafter, these genes were assessed for alterations in transcriptional activity after exposure to 4-methylbenzylidene camphor (4MBC) or benzophenone-3 (BP-3), two extensively used sunscreens. We found that both chemicals disturbed the expression of all four genes analyzed: hormonal receptor 38 (HR38), methoprene-tolerant (Met), membrane-associate progesterone receptor (MAPR) and insulin-like receptor (INSR), measured by changes in mRNA levels by real-time PCR. An upregulatory effect at the genomic level was detected in different developmental stages. Interestingly, embryos appeared to be more sensitive to the action of the UV filters than larvae. Our results suggest that the risk of disruption through different endocrine routes is not negligible, considering the significant effects of UV filters on key hormonal receptor and regulatory genes. Further effort is needed to develop environmental risk assessment studies on these pollutants, particularly for aquatic invertebrate model organisms. Copyright © 2016 Elsevier Ltd. All rights reserved.

Study of Salvia Officinalis Hydroethanolic Extract on Serum Thyroid Hormone Levels in Hypothyroid Male Rat

Directory of Open Access Journals (Sweden)

N. Mirazi

2013-01-01

Full Text Available Introduction & Objective: Medicinal plants are widely used throughout the world. Hypothyroid-ism is an important hormonal disease that causes some disorders in body organs. Salvia offi-cinalis has been known as a medicinal plant since ancient times. In this study the Salvia offi-cinalis extract (SOE effects on thyroid hormones and TSH in hypothyroid rats have been investigated. Materials & Methods: In this experimental study the SOE extract was prepared and 40 male rats were randomly divided in five groups. Control, propylthiouracil (PTU in 4 groups + SOE. The animals were induced hypothyroidism by administration of PTU 0.1% orally in tap water for 14 days. The blood samples were collected and T3 & T4 and TSH hormones were analyzed. Hypothyroid groups were divided into 4 groups and received (PTU+ SOE 40 mg/kg +levothyroxine sodium, 15mcg/kg, orally in tap water and LV+ SOE. All test groups were treated with SOE and levothyroxine sodium for one week. The blood samples were col-lected and for T3 & T4 and TSH hormones were analyzed at the end of the 3rd week. All data were expressed as mean ± SEM and all statistical procedures were performed by MANOVA test.Results: Our results showed that the T3 & T4 plasma levels in hypothyroid animals treated by SOE had significant differences (P<0.05 compared with the control group. Conclusion: Our findings suggest that the SOE has stimulatory effect on thyroid gland func-tion and raises plasma T3 & T4 levels.(Sci J Hamadan Univ Med Sci 2013; 19 (4:27-35

Outcome of salvage radiotherapy for biochemical failure after radical prostatectomy with or without hormonal therapy

International Nuclear Information System (INIS)

Cheung, Rex; Kamat, Ashish M.; Crevoisier, Renaud de; Allen, Pamela K.; Lee, Andrew K.; Tucker, Susan L.; Pisters, Louis; Babaian, Richard J.; Kuban, Deborah

2005-01-01

Background: This study analyzed the outcome of salvage radiotherapy for biochemical failure after radical prostatectomy (RP). By comparing the outcomes for patients who received RT alone and for those who received combined RT and hormonal therapy, we assessed the potential benefits of hormonal therapy. Patients and Methods: This cohort was comprised of 101 patients who received salvage RT between 1990 and 2001 for biochemical failure after RP. Fifty-nine of these patients also received hormone. Margin status (positive vs. negative), extracapsular extension (yes vs. no), seminal vesicle involvement (yes vs. no), pathologic stage, Gleason score, pre-RP PSA, post-RP PSA, pre-RT PSA, hormonal use, radiotherapy dose and technique, RP at M. D. Anderson Cancer Center, and time from RP to salvage RT were analyzed. Statistically significant variables were used to construct prognostic groups. Results: Independent prognostic factors for the RT-alone group were margin status and pre-RT PSA. RP at M. D. Anderson Cancer Center was marginally significant (p = 0.06) in multivariate analysis. Pre-RT PSA was the only significant prognostic factor for the combined-therapy group. We used a combination of margin status and pre-RT PSA to construct a prognostic model for response to the salvage treatment based on the RT group. We identified the favorable group as those patients with positive margin and pre-RT PSA ≤0.5 ng/mL vs. the unfavorable group as otherwise. This stratification separates patients into clinically meaningful groups. The 5-year PSA control probabilities for the favorable vs. the unfavorable group were 83.7% vs. 61.7% with radiotherapy alone (p = 0.03). Androgen ablation seemed to be most beneficial in the unfavorable group. Conclusion: After prostatectomy, favorable-group patients may fare well with salvage radiotherapy alone. These patients may be spared the toxicity of androgen ablation. The other patients may benefit most from a combined approach with hormonal

Vascular Ehlers-Danlos Syndrome Presenting as a Pulsatile Neck Mass: a Case Report and Review of Literature.

Science.gov (United States)

Maraj, Bharat; Harding-Theobald, Emily; Karaki, Fatima

2018-04-26

Ehlers-Danlos syndrome refers to a spectrum of connective tissue disorders typically caused by mutations in genes responsible for the synthesis of collagen. Patients with Ehlers-Danlos syndrome often exhibit hyperflexibility of joints, increased skin elasticity, and tissue fragility. Vascular Ehlers-Danlos (vEDS) is a subtype of Ehlers-Danlos syndrome with a predilection to involve blood vessels. As such, it often manifests as vascular aneurysms and vessel rupture leading to hemorrhage. There are few reports describing primary prevention of aneurysms in the setting of undiagnosed, suspected vEDS. We present a case of a 30-year-old woman who presents with a pulsatile neck mass found to have multiple arterial aneurysms on imaging, hyperflexibility, and characteristic facial features consistent with vEDS. As described in this case, management of a suspected connective tissue disorder is a multidisciplinary approach including vascular surgery, medical therapy, and genetic testing to confirm the diagnosis. We review literature regarding the care of patients with vascular Ehlers-Danlos as it might pertain to hospitalized patients.

High Fat High Sugar Diet Reduces Voluntary Wheel Running in Mice Independent of Sex Hormone Involvement

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Heather L. Vellers

2017-08-01

Full Text Available Introduction: Indirect results in humans suggest that chronic overfeeding decreases physical activity with few suggestions regarding what mechanism(s may link overfeeding and decreased activity. The primary sex hormones are known regulators of activity and there are reports that chronic overfeeding alters sex hormone levels. Thepurpose of this study was to determine if chronic overfeeding altered wheel running through altered sex hormone levels.Materials and Methods: C57BL/6J mice were bred and the pups were weaned at 3-weeks of age and randomly assigned to either a control (CFD or high fat/high sugar (HFHS diet for 9–11 weeks depending on activity analysis. Nutritional intake, body composition, sex hormone levels, and 3-day and 2-week wheel-running activity were measured. Additionally, groups of HFHS animals were supplemented with testosterone (males and 17β-estradiol (females to determine if sex hormone augmentation altered diet-induced changes in activity.Results: 117 mice (56♂, 61♀ were analyzed. The HFHS mice consumed significantly more calories per day than CFD mice (male: p < 0.0001; female: p < 0.0001 and had significantly higher body fat (male: p < 0.0001; female: p < 0.0001. The HFHS diet did not reduce sex hormone levels, but did significantly reduce acute running-wheel distance in male (p = 0.05, 70 ± 28% and female mice (p = 0.02, 57 ± 26%. In animals that received hormone supplementation, there was no significant effect on activity levels. Two-weeks of wheel access was not sufficient to alter HFHS-induced reductions in activity or increases in body fat.Conclusion: Chronic overfeeding reduces wheel running, but is independent of the primary sex hormones.

Thyroid-stimulating hormone pituitary adenomas.

Science.gov (United States)

Clarke, Michelle J; Erickson, Dana; Castro, M Regina; Atkinson, John L D

2008-07-01

Thyroid-stimulating hormone (TSH)-secreting pituitary adenomas are rare, representing secreting or clinically silent TSH-immunostaining pituitary tumors among all pituitary adenomas followed at their institution between 1987 and 2003. Patient records, including clinical, imaging, and pathological and surgical characteristics were reviewed. Twenty-one patients (6 women and 15 men; mean age 46 years, range 26-73 years) were identified. Of these, 10 patients had a history of clinical hyperthyroidism, of whom 7 had undergone ablative thyroid procedures (thyroid surgery/(131)I ablation) prior to the diagnosis of pituitary adenoma. Ten patients had elevated TSH preoperatively. Seven patients presented with headache, and 8 presented with visual field defects. All patients underwent imaging, of which 19 were available for imaging review. Sixteen patients had macroadenomas. Of the 21 patients, 18 underwent transsphenoidal surgery at the authors' institution, 2 patients underwent transsphenoidal surgery at another facility, and 1 was treated medically. Patients with TSH-secreting tumors were defined as in remission after surgery if they had no residual adenoma on imaging and had biochemical evidence of hypo-or euthyroidism. Patients with TSH-immunostaining tumors were considered in remission if they had no residual tumor. Of these 18 patients, 9 (50%) were in remission following surgery. Seven patients had residual tumor; 2 of these patients underwent further transsphenoidal resection, 1 underwent a craniotomy, and 4 underwent postoperative radiation therapy (2 conventional radiation therapy, 1 Gamma Knife surgery, and 1 had both types of radiation treatment). Two patients had persistently elevated TSH levels despite the lack of evidence of residual tumor. On pathological analysis and immunostaining of the surgical specimen, 17 patients had samples that stained positively for TSH, 8 for alpha-subunit, 10 for growth hormone, 7 for prolactin, 2 for adrenocorticotrophic hormone

Correlations Between Seminal Plasma Hormones and Sperm ...

African Journals Online (AJOL)

Context: There is a complex relationship between seminal plasma hormone levels and infertility in men. Previous studies had shown no specific pattern in the serum or seminal plasma hormone profiles of men with infertility and it is debatable whether there is a need to perform routine seminal hormone assays in the ...

Some important concepts in development of radioimmunoassay (RIA) for hormones, viruses and drugs. [Peptide hormones, non-peptide hormones

Energy Technology Data Exchange (ETDEWEB)

Shah, K B; Mani, R S [Bhabha Atomic Research Centre, Bombay (India). Radiopharmaceuticals Section

1981-01-01

Radioimmunoassay (RIA) procedures for the quantitative measurement of polypeptide and steroid hormones and other substances of medical and biological interest constitute one of the most important and rapidly expanding groups of applications of radioactive tracers in analytical chemistry and the life sciences. The method consists in setting up assays wherein the isotopically tagged substance is allowed to compete with its non-radioactive counterpart for the limited binding sites of a specific antibody. The degree of competitive inhibition of binding of labelled tracer is determined by measuring the radioactivity of the bound or unbound (free) complex, and comparing with the corresponding values for standard solutions of known concentration. This paper outlines the salient features, and specific problems associated with the preparation, purification of immunoreactive labelled tracers, and other suitable RIA reagents, the stability and storage conditions and standardisation of assay procedure. The characteristics of the assay systems have been investigated in detail and regular quality control has been instituted for evaluating various statistical parameters, inter-assay and intra-assay variances, and effective shelf life of the RIA reagents, with specific reference to assays of insulin growth hormones and thyroid and pregnancy hormones.

The Different Effects Of Endogenous And Exogenous Sex Hormones On Cerebrovascular Diseases

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Mehdi Shafiee Sabet

2017-02-01

Full Text Available Background: A sexual dimorphism is seen in ischemic stroke. Women have lower stroke incidence than men until an advanced age, when the epidemiology of ischemic stroke shifts and incidence rises dramatically in women. This could indicate the role of sex hormones in pathogenesis of cerebrovascular diseases. This Review summarizes the sex differences related to stroke, and the effects of endogenous and exogenAous hormones on the cerebrovasculature of the male and female brain. Methods: We conducted a vast review to analyze possible associations between exposure to endogenous and exogenous female and male steroid hormones and the risks of cerebrovascular diseases. This association is discussed in the context of the effects of sex hormone levels on the progression of atherosclerosis, the vascular tone, and various risk factors including patient's lipid profile, arterial blood pressure and diabetes. Their therapeutic potentials is also reviewed. Results: There is a debate on the role of androgens. A large array of data testifies in favor of a variety of neuroprotective androgen effects in men mostly, but in many cases in women as well. Testosterone supplementation in low to normal levels in hypogonadal men has mostly been shown to benefit the subjects receiving it, but administration in supraphysiological doses however, along with anabolic steroid abuse, seems to adversely affect both the lipid profile and insulin sensitivity in men. Its effects in women have yet to be researched in depth. Due to the lower stroke incidence observed in pre-menopausal women and robust preclinical evidence of neuroprotective and anti-inflammatory properties of estrogen, researchers have focused on the potential benefits of hormones to reduce ischemic brain injury. However, hormone therapy to postmenopausal females increases the risk and severity of ischemic stroke. Moreover, while estrogen treatment is neuroprotective in younger females, estrogen paradoxically increases

Labelling and standardizing some pituitary hormones for radioimmunoassay

International Nuclear Information System (INIS)

Kim, Y.S.

1976-11-01

Optimum conditions for efficient 125 I labelling of human follicle stimulating hormone (FSH) and human chorionic gonadotropin (HCG) using chloramine-T have been established for radioimmunoassay (RIA). The amount of the hormone, chloramine-T, 125 I, and the reaction time were, respetively, controlled evaluating the yield and the bindability of the labelled hormone to its antibody. To measure the bindability, the labelled hormone was incubated together with its antibody for a definite temperature. In the separation of the free hormone (F) from the antibody bound (B), a double antibody technique was applied comparing with the chromatoelectrophoresis. For the efficient separation of the labelled hormone, two methods of separation such as gel filtration and gel electrophoresis were compared in the sensitivity and in the immunological activity points of view. Experiments for the production of HCG antibody were also conducted. The produced antisera were tested in two ways; i.e., the incubation test with the labelled hormone, and the Ouchterlony test. Using the produced anti-HCG serum and the purchased anti-FSH serum, standard dose-response curves were plotted correlating with the international standard preparation of the hormones

Lipoproteína a, aterosclerosis y terapia hormonal de reemplazo Lipoprotein a, atherosclerosis and replacement hormone therapy

Directory of Open Access Journals (Sweden)

Miguel Lugones Botell

2005-08-01

Full Text Available Se realizó una revisión sobre la lipoproteína plasmática, Lp(a, cuyo papel fisiológico es poco conocido. Se ha descrito una asociación entre las concentraciones aumentadas de Lp(a y el proceso aterosclerótico. Además, su exceso podría inducir una disminución de la actividad fibrinolítica y, por tanto, favorecer la trombosis. También analizamos la terapia hormonal de reemplazo. En relación con los efectos positivos, mejora los síntomas climatéricos y previene la osteoporosis, aunque entre los efectos adversos en las mujeres que la siguen, se ha descrito un ligero aumento del riesgo del tromboembolismo venoso, y más recientemente, en estudios realizados en EE.UU. en los años 2002 y 2004, en el ya conocido estudio (Women´s Health Initiative Study, se reportó mayor incidencia de eventos cardiovasculares para la terapia combinada con estrógenos conjugados equinos y medroxiprogesterona, y de stroke para la terapia estrogénica. Estos estudios pusieron en su lugar los efectos de esta terapia, que no es totalmente inocua. Se precisan estudios más amplios para definir el papel de la terapia hormonal de reemplazo y otras medidas terapéuticas sobre el sistema hemostático, el metabolismo lipídico y la enfermedad cardiovascular.A review of plasmatic lipoprotein, Lp(a, whose physiological role is little known, was made. An association between the augmented concentrations of Lp(a and the atherosclerotic proccess has been described. Besides, its excess may lead to a reduction of the fibrinolytic activity and, therefore, favor thrombosis. The replacement hormone therapy was also analyzed. In relation to its positive effects, it improves the climacteric symptoms and prevents osteoporosis. Among its adverse effects, it has been observed a mild increase of the risk for venous thromboembolism and, more recently, in the aleady known Women's Health Initiative Study, it was reported a higher incidence of cardiovascular events for the combined

Dynamic time warping and machine learning for signal quality assessment of pulsatile signals

International Nuclear Information System (INIS)

Li, Q; Clifford, G D

2012-01-01

In this work, we describe a beat-by-beat method for assessing the clinical utility of pulsatile waveforms, primarily recorded from cardiovascular blood volume or pressure changes, concentrating on the photoplethysmogram (PPG). Physiological blood flow is nonstationary, with pulses changing in height, width and morphology due to changes in heart rate, cardiac output, sensor type and hardware or software pre-processing requirements. Moreover, considerable inter-individual and sensor-location variability exists. Simple template matching methods are therefore inappropriate, and a patient-specific adaptive initialization is therefore required. We introduce dynamic time warping to stretch each beat to match a running template and combine it with several other features related to signal quality, including correlation and the percentage of the beat that appeared to be clipped. The features were then presented to a multi-layer perceptron neural network to learn the relationships between the parameters in the presence of good- and bad-quality pulses. An expert-labeled database of 1055 segments of PPG, each 6 s long, recorded from 104 separate critical care admissions during both normal and verified arrhythmic events, was used to train and test our algorithms. An accuracy of 97.5% on the training set and 95.2% on test set was found. The algorithm could be deployed as a stand-alone signal quality assessment algorithm for vetting the clinical utility of PPG traces or any similar quasi-periodic signal. (paper)

Dynamic time warping and machine learning for signal quality assessment of pulsatile signals.

Science.gov (United States)

Li, Q; Clifford, G D

2012-09-01

In this work, we describe a beat-by-beat method for assessing the clinical utility of pulsatile waveforms, primarily recorded from cardiovascular blood volume or pressure changes, concentrating on the photoplethysmogram (PPG). Physiological blood flow is nonstationary, with pulses changing in height, width and morphology due to changes in heart rate, cardiac output, sensor type and hardware or software pre-processing requirements. Moreover, considerable inter-individual and sensor-location variability exists. Simple template matching methods are therefore inappropriate, and a patient-specific adaptive initialization is therefore required. We introduce dynamic time warping to stretch each beat to match a running template and combine it with several other features related to signal quality, including correlation and the percentage of the beat that appeared to be clipped. The features were then presented to a multi-layer perceptron neural network to learn the relationships between the parameters in the presence of good- and bad-quality pulses. An expert-labeled database of 1055 segments of PPG, each 6 s long, recorded from 104 separate critical care admissions during both normal and verified arrhythmic events, was used to train and test our algorithms. An accuracy of 97.5% on the training set and 95.2% on test set was found. The algorithm could be deployed as a stand-alone signal quality assessment algorithm for vetting the clinical utility of PPG traces or any similar quasi-periodic signal.

Catch-up growth in early treated patients with growth hormone deficiency. Dutch Growth Hormone Working Group.

OpenAIRE

Boersma, B; Rikken, B; Wit, J M

1995-01-01

Catch-up growth of 26 children with growth hormone deficiency during four years of growth hormone treatment, which was started young (< 3 years), was compared with that of 16 children with coeliac disease on a gluten free diet. In children with growth hormone deficiency mean (SD) height SD score increased from -4.3 (1.8) to -1.9 (1.4) and in patients with coeliac disease from -1.8 (0.9) to -0.1 (0.8). Height SD score after four years correlated positively with injection frequency and height S...

Why sex hormones matter for neuroscience: A very short review on sex, sex hormones, and functional brain asymmetries.

Science.gov (United States)

Hausmann, Markus

2017-01-02

Biological sex and sex hormones are known to affect functional cerebral asymmetries (FCAs). Men are generally more lateralized than women. The effect size of this sex difference is small but robust. Some of the inconsistencies in the literature may be explained by sex-related hormonal differences. Most studies focusing on neuromodulatory properties of sex hormones on FCAs have investigated women during the menstrual cycle. Although contradictions exist, these studies have typically shown that levels of estradiol and/or progesterone correlate with the degree of FCAs, suggesting that sex differences in FCAs partially depend on hormonal state and day of testing. The results indicate that FCAs are not fixed but are hormone dependent, and as such they can dynamically change within relatively short periods throughout life. Many issues raised in this Mini-Review refer not only to FCAs but also to other aspects of functional brain organization, such as functional connectivity within and between the cerebral hemispheres. Our understanding of sex differences in brain and behavior as well as their clinical relevance will improve significantly if more studies routinely take sex and sex hormones into account. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

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

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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.

Lifetime Dependent Variation of Stress Hormone Metabolites in Feces of Two Laboratory Mouse Strains.

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Thomas Kolbe

Full Text Available Non-invasive measurement of stress hormone metabolites in feces has become routine practice for the evaluation of distress and pain in animal experiments. Since metabolism and excretion of glucocorticoids may be variable, awareness and adequate consideration of influencing factors are essential for accurate monitoring of adrenocortical activity. Reference values are usually provided by baselines compiled prior to the experiment and by age matched controls. The comparison of stress hormone levels between animals of different ages or between studies looking at hormone levels at the beginning and at the end of a long term study might be biased by age-related effects. In this study we analyzed fecal corticosterone metabolites (FCM during the lifetime of untreated female mice of the strains C57BL/6NCrl and Crl:CD1. For this purpose feces for each individual mouse were collected every two months over a period of 24 hours, at intervals of four hours, until the age of 26 months. Results of the study revealed that age of the animals had a significant impact on the level and circadian rhythm of stress hormone metabolites. Furthermore, long-term observation of mice revealed a strain specific excretion profile of FCM influenced by strong seasonal variability.

[Human growth hormone and Turner syndrome].

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Sánchez Marco, Silvia Beatriz; de Arriba Muñoz, Antonio; Ferrer Lozano, Marta; Labarta Aizpún, José Ignacio; Garagorri Otero, Jesús María

2017-02-01

The evaluation of clinical and analytical parameters as predictors of the final growth response in Turner syndrome patients treated with growth hormone. A retrospective study was performed on 25 girls with Turner syndrome (17 treated with growth hormone), followed-up until adult height. Auxological, analytical, genetic and pharmacological parameters were collected. A descriptive and analytical study was conducted to evaluate short (12 months) and long term response to treatment with growth hormone. A favourable treatment response was shown during the first year of treatment in terms of height velocity gain in 66.6% of cases (height-gain velocity >3cm/year). A favourable long-term treatment response was also observed in terms of adult height, which increased by 42.82±21.23cm (1.25±0.76 SDS), with an adult height gain of 9.59±5.39cm (1.68±1.51 SDS). Predictors of good response to growth hormone treatment are: A) initial growth hormone dose, B) time on growth hormone treatment until starting oestrogen therapy, C) increased IGF1 and IGFBP-3 levels in the first year of treatment, and D) height gain velocity in the first year of treatment. Copyright © 2015 Asociación Española de Pediatría. Publicado por Elsevier España, S.L.U. All rights reserved.

Two families with normosmic congenital hypogonadotropic hypogonadism and biallelic mutations in KISS1R (KISS1 receptor: clinical evaluation and molecular characterization of a novel mutation.

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Frédéric Brioude

Full Text Available CONTEXT: KISS1R mutations have been reported in few patients with normosmic congenital hypogonadotropic hypogonadism (nCHH (OMIM #146110. OBJECTIVE: To describe in detail nCHH patients with biallelic KISS1R mutations belonging to 2 unrelated families, and to functionally characterize a novel KISS1R mutation. RESULTS: An original mutant, p.Tyr313His, was found in the homozygous state in 3 affected kindred (2 females and 1 male from a consanguineous Portuguese family. This mutation, located in the seventh transmembrane domain, affects a highly conserved amino acid, perturbs the conformation of the transmembrane segment, and impairs MAP kinase signaling and intracellular calcium release. In the second family, a French Caucasian male patient with nCHH was found to carry two recurrent mutations in the compound heterozygous state (p.Leu102Pro/Stop399Arg. In this man, pulsatile GnRH (Gonadotropin Releasing Hormone administration restored pulsatile LH (Luteinizing Hormone secretion and testicular hormone secretion. Later, long-term combined gonadotropin therapy induced spermatogenesis, enabling 3 successive pregnancies that resulted in 2 miscarriages and the birth of a healthy boy. CONCLUSION: We show that a novel loss-of-function mutation (p.Tyr313His in the KISS1R gene can cause familial nCHH, revealing the crucial role of this amino acid in KISS1R function. The observed restoration of gonadotropin secretion by exogenous GnRH administration further supports, in humans, the hypothalamic origin of the gonadotropin deficiency in this genetic form of nCHH.

Should symptomatic menopausal women be offered hormone therapy?

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Lobo, Rogerio A; Bélisle, Serge; Creasman, William T; Frankel, Nancy R; Goodman, Neil E; Hall, Janet E; Ivey, Susan Lee; Kingsberg, Sheryl; Langer, Robert; Lehman, Rebecca; McArthur, Donna Behler; Montgomery-Rice, Valerie; Notelovitz, Morris; Packin, Gary S; Rebar, Robert W; Rousseau, MaryEllen; Schenken, Robert S; Schneider, Diane L; Sherif, Katherine; Wysocki, Susan

2006-01-01

Many physicians remain uncertain about prescribing hormone therapy for symptomatic women at the onset of menopause. The American Society for Reproductive Medicine (ASRM) convened a multidisciplinary group of healthcare providers to discuss the efficacy and risks of hormone therapy for symptomatic women, and to determine whether it would be appropriate to treat women at the onset of menopause who were complaining of menopausal symptoms. Numerous controlled clinical trials consistently demonstrate that hormone therapy, administered via oral, transdermal, or vaginal routes, is the most effective treatment for vasomotor symptoms. Topical vaginal formulations of hormone therapy should be preferred when prescribing solely for the treatment of symptoms of vulvar and vaginal atrophy. Data from the Women's Health Initiative indicate that the overall attributable risk of invasive breast cancer in women receiving estrogen plus progestin was 8 more cases per 10,000 women-years. No increased risk for invasive breast cancer was detected for women who never used hormone therapy in the past or for those receiving estrogen only. Hormone therapy is not effective for the treatment of cardiovascular disease and that the risk of cardiovascular disease with hormone therapy is principally in older women who are considerably postmenopause. Healthy symptomatic women should be offered the option of hormone therapy for menopausal symptoms. Symptom relief with hormone therapy for many younger women (at the onset of menopause) with menopausal symptoms outweighs the risks and may provide an overall improvement in quality of life. Hormone therapy should be individualized for symptomatic women. This involves tailoring the regimen and dose to individual needs.

Growth hormone stimulation test - series (image)

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