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Sample records for analyzing pulsatile hormone

  1. Nonlinear analysis and prediction of pulsatile hormone secretion

    Energy Technology Data Exchange (ETDEWEB)

    Prank, K. [Abteilung Klinische Endokrinologie, Medizinische Hochschule Hannover, D-30623 Hannover (Germany)]|[Howard Hughes Medical Institute and Computational Neurobiology Laboratory, The Salk Institute, San Diego, California 92186-5800 (United States); Kloppstech, M. [Abteilung Klinische Endokrinologie, Medizinische Hochschule Hannover, D-30623 Hannover (Germany); Nowlan, S.J. [Howard Hughes Medical Institute and Computational Neurobiology Laboratory, The Salk Institute, San Diego, California 92186-5800 (United States); Harms, H.M.; Brabant, G.; Hesch, R. [Abteilung Klinische Endokrinologie, Medizinische Hochschule Hannover, D-30623 Hannover (Germany); Sejnowski, T.J. [Howard Hughes Medical Institute and Computational Neurobiology Laboratory, The Salk Institute, San Diego, California 92186-5800 (United States)

    1996-06-01

    Pulsatile hormone secretion is observed in almost every hormonal system. The frequency of episodic hormone release ranges from approximately 10 to 100 pulses in 24 hours. This temporal mode of secretion is an important feature of intercellular information transfer in addition to a dose-response dependent regulation. It has been demonstrated in a number of experiments that changes in the temporal pattern of pulsatile hormone secretion specifically regulate cellular and organ function and structure. Recent evidence links osteoporosis, a disease characterized by loss of bone mass and structure, to changes in the dynamics of pulsatile parathyroid hormone (PTH) secretion. In our study we applied nonlinear and linear time series prediction to characterize the secretory dynamics of PTH in both healthy human subjects and patients with osteoporosis. Osteoporotic patients appear to lack periods of high predictability found in normal humans. In contrast to patients with osteoporosis patients with hyperparathyroidism, a condition which despite sometimes reduced bone mass has a preserved bone architecture, show periods of high predictability of PTH secretion. Using stochastic surrogate data sets which match certain statistical properties of the original time series significant nonlinear determinism could be found for the PTH time series of a group of healthy subjects. Using classical nonlinear analytical techniques we could demonstrate that the irregular pattern of pulsatile PTH secretion in healthy men exhibits characteristics of deterministic chaos. Pulsatile secretion of PTH in healthy subjects seems to be a first example of nonlinear determinism in an apparently irregular hormonal rhythm in human physiology. {copyright} {ital 1996 American Institute of Physics.}

  2. Nonlinear analysis and prediction of pulsatile hormone secretion

    International Nuclear Information System (INIS)

    Pulsatile hormone secretion is observed in almost every hormonal system. The frequency of episodic hormone release ranges from approximately 10 to 100 pulses in 24 hours. This temporal mode of secretion is an important feature of intercellular information transfer in addition to a dose-response dependent regulation. It has been demonstrated in a number of experiments that changes in the temporal pattern of pulsatile hormone secretion specifically regulate cellular and organ function and structure. Recent evidence links osteoporosis, a disease characterized by loss of bone mass and structure, to changes in the dynamics of pulsatile parathyroid hormone (PTH) secretion. In our study we applied nonlinear and linear time series prediction to characterize the secretory dynamics of PTH in both healthy human subjects and patients with osteoporosis. Osteoporotic patients appear to lack periods of high predictability found in normal humans. In contrast to patients with osteoporosis patients with hyperparathyroidism, a condition which despite sometimes reduced bone mass has a preserved bone architecture, show periods of high predictability of PTH secretion. Using stochastic surrogate data sets which match certain statistical properties of the original time series significant nonlinear determinism could be found for the PTH time series of a group of healthy subjects. Using classical nonlinear analytical techniques we could demonstrate that the irregular pattern of pulsatile PTH secretion in healthy men exhibits characteristics of deterministic chaos. Pulsatile secretion of PTH in healthy subjects seems to be a first example of nonlinear determinism in an apparently irregular hormonal rhythm in human physiology. copyright 1996 American Institute of Physics

  3. Single dose and pulsatile treatment with human growth hormone in growth hormone deficiency.

    OpenAIRE

    Smith, P J; Pringle, P J; Brook, C G

    1987-01-01

    The growth and growth hormone profiles in four children receiving three different regimens of treatment with human growth hormone (hGH) were compared. There was no significant difference in the rate of growth between the regimens; the rate of growth fell dramatically after treatment. Pulsatile administration of hGH was no better than conventional treatment.

  4. One hundred pregnancies after treatment with pulsatile luteinizing-hormone releasing hormone to induce ovulation

    OpenAIRE

    Homburg, R.; Eshel, A.; Armar, NA; Tucker, M.; Mason, PW; Adams, J.; Kilborn, J.; Sutherland, IA; Jacobs, HS

    1989-01-01

    OBJECTIVE--To review treatment with pulsatile luteinising hormone releasing hormone in infertile women who do not ovulate and are resistant to clomiphene after 100 pregnancies achieved with this treatment. DESIGN--Retrospective analysis of 146 courses of treatment over 434 cycles. SETTING--Infertility clinic. PATIENTS--118 Women whose failure to ovulate was due to idiopathic hypogonadotrophic hypogonadism (n = 39), amenorrhoea related to low weight (n = 17), organic pituitary disease (n = 15)...

  5. Pulsatile glycoprotein hormone secretion in glycoprotein-producing pituitary tumors.

    Science.gov (United States)

    Samuels, M H; Henry, P; Kleinschmidt-Demasters, B K; Lillehei, K; Ridgway, E C

    1991-12-01

    To study patterns of hormone production and secretion in glycoprotein-producing pituitary tumors, 12 patients with such tumors underwent the following studies. Preoperatively, all patients had serum TSH, LH, FSH, and alpha-subunit levels measured every 15 min for 24 h. Hormone pulses were located by cluster analysis, and pulse parameters were compared to those in healthy young men, healthy young women, healthy postmenopausal women, and subjects with primary hypothyroidism. After surgery, immunocytochemistry for the four glycoproteins was performed on all tumors, and Northern blot analysis was performed in six tumors with probes for the four subunits. By immunocytochemistry, 42% of the tumors were positive for TSH beta, 83% for LH beta, 75% for FSH beta, and 92% for alpha-subunit. Preoperative serum hormone levels varied widely between patients and were not well correlated with the intensity of immunocytochemical staining. Northern blot analysis did not appear to be as sensitive as immunocytochemistry for detection of the glycoproteins. All patients had pulsatile glycoprotein secretion, with pulses of normal frequency but varied amplitude. These results suggest that in patients with glycoprotein tumors, hormone pulses may be an integral part of autonomous secretion, or that hypothalamic control is involved in glycoprotein secretion and, perhaps, in the pathogenesis of these tumors. PMID:1955510

  6. Nonlinear dynamics in pulsatile secretion of parathyroid hormone in normal human subjects

    Science.gov (United States)

    Prank, Klaus; Harms, Heio; Brabant, Georg; Hesch, Rolf-Dieter; Dämmig, Matthias; Mitschke, Fedor

    1995-03-01

    In many biological systems, information is transferred by hormonal ligands, and it is assumed that these hormonal signals encode developmental and regulatory programs in mammalian organisms. In contrast to the dogma of endocrine homeostasis, it could be shown that the biological information in hormonal networks is not only present as a constant hormone concentration in the circulation pool. Recently, it has become apparent that hormone pulses contribute to this hormonal pool, which modulates the responsiveness of receptors within the cell membrane by regulation of the receptor synthesis, movement within the membrane layer, coupling to signal transduction proteins and internalization. Phase space analysis of dynamic parathyroid hormone (PTH) secretion allowed the definition of a (in comparison to normal subjects) relatively quiet ``low dynamic'' secretory pattern in osteoporosis, and a ``high dynamic'' state in hyperparathyroidism. We now investigate whether this pulsatile secretion of PTH in healthy men exhibits characteristics of nonlinear determinism. Our findings suggest that this is conceivable, although on the basis of presently available data and techniques, no proof can be established. Nevertheless, pulsatile secretion of PTH might be a first example of nonlinear deterministic dynamics in an apparently irregular hormonal rhythm in human physiology.

  7. Overtrained horses alter their resting pulsatile growth hormone secretion

    OpenAIRE

    de Graaf-Roelfsema, E.; Veldhuis, P. P.; Keizer, H.A.; van Ginneken, M. M. E.; van Dam, K. G.; Johnson, M L; Barneveld, A.; Menheere, P. P. C. A.; van Breda, E; Wijnberg, I. D.; van der Kolk, J. H.

    2009-01-01

    The influence of intensified and reduced training on nocturnal growth hormone (GH) secretion and elimination dynamics was studied in young (1.5 yr) Standardbred geldings to detect potential markers indicative for early overtraining. Ten horses trained on a treadmill for 32 wk in age-, breed-, and gender-matched fixed pairs. Training was divided into four phases (4, 18, 6, and 4 wk, respectively): 1) habituation to high-speed treadmill trotting, 2) normal training, in which speed and duration ...

  8. Induction of ovulation in anestrous mares with pulsatile administration of gonadotropin-releasing hormone.

    Science.gov (United States)

    Johnson, A L

    1986-05-01

    Four seasonally anestrous mares (Standardbred), housed under a nonstimulatory photoperiod of 8 hours light:16 hours dark, were administered gonadotropin-releasing hormone (GnRH) in a pulsatile pattern (50 or 250 micrograms of GnRH/hour) for 8 to 18 days during February and March 1985. Treatment with GnRH, irrespective of dose or month, induced an increase in serum luteinizing hormone from a mean pretreatment value typical of anestrus (0.58 +/- 0.02 ng/ml +/- SE) to 10.84 +/- 1.27 ng/ml on day 8 of GnRH treatment. Ovulation in the 4 mares occurred 8.8 +/- 0.7 days after the initiation of pulsatile GnRH administration. In each instance, ovulation was followed by a functional corpus luteum, as indicated by a luteal phase (defined as the number of days on which serum levels of progesterone were greater than 1.0 ng/ml) which lasted 14.5 +/- 0.6 days. These results indicate that infusion of GnRH in a pulsatile pattern is effective in inducing follicular development and ovulation in anestrous mares in the absence of a stimulatory photoperiod. PMID:3521408

  9. Frequency-Dependent Regulation of Follicle-Stimulating Hormone β by Pulsatile Gonadotropin-Releasing Hormone Is Mediated by Functional Antagonism of bZIP Transcription Factors ▿

    Science.gov (United States)

    Ciccone, Nick A.; Xu, Shuyun; Lacza, Charlemagne T.; Carroll, Rona S.; Kaiser, Ursula B.

    2010-01-01

    Oscillatory synthesis and secretion of the gonadotropins, follicle-stimulating hormone (FSH) and luteinizing hormone (LH), under the control of pulsatile hypothalamic gonadotropin-releasing hormone (GnRH), is essential for normal reproductive development and fertility. The molecular mechanisms by which various patterns of pulsatile GnRH regulate gonadotrope responsiveness remain poorly understood. In contrast to the α and LHβ subunit genes, FSHβ subunit transcription is preferentially stimulated at low rather than high frequencies of pulsatile GnRH. In this study, mutation of a cyclic AMP response element (CRE) within the FSHβ promoter resulted in the loss of preferential GnRH stimulation at low pulse frequencies. We hypothesized that high GnRH pulse frequencies might stimulate a transcriptional repressor(s) to attenuate the action of CRE binding protein (CREB) and show that inducible cAMP early repressor (ICER) fulfills such a role. ICER was not detected under basal conditions, but pulsatile GnRH stimulated ICER to a greater extent at high than at low pulse frequencies. ICER binds to the FSHβ CRE site to reduce CREB occupation and abrogates both maximal GnRH stimulation and GnRH pulse frequency-dependent effects on FSHβ transcription. These data suggest that ICER production antagonizes the stimulatory action of CREB to attenuate FSHβ transcription at high GnRH pulse frequencies, thereby playing a critical role in regulating cyclic reproductive function. PMID:20008557

  10. Effects of a Growth Hormone-Releasing Hormone Analog on Endogenous GH Pulsatility and Insulin Sensitivity in Healthy Men

    OpenAIRE

    Stanley, Takara L.; Chen, Cindy Y.; Branch, Karen L.; Makimura, Hideo; GRINSPOON, Steven K.

    2010-01-01

    Context and Objective: Strategies to augment pulsatile GH may be beneficial in patients with excess visceral adiposity, in whom GH secretion is reduced. The objective of this study was to determine the effects of a novel GHRH (GHRH1–44) analog, tesamorelin, on endogenous GH pulsatility and insulin sensitivity in healthy men.

  11. Negative feedback regulation of pulsatile growth hormone secretion by insulin-like growth factor I. Involvement of hypothalamic somatostatin.

    OpenAIRE

    Bermann, M; Jaffe, C A; Tsai, W.; DeMott-Friberg, R; Barkan, A. L.

    1994-01-01

    To investigate the mechanisms of the negative feedback inhibition of growth hormone (GH) secretion by IGF-I, we studied parameters of GH pulsatility in six normal, fed men before and during a 48-h infusion of recombinant human IGF-I (rhIGF-I) (10-15 micrograms/kg per h). Plasma levels of IGF-I increased from the baseline value of 163.5 +/- 9.3 micrograms/liter (mean +/- SE) to a new steady state of 452.0 +/- 20.9 micrograms/liter during the infusion. Plasma GH concentrations were measured eve...

  12. Pulsatile growth hormone secretion in patients with acromegaly and normal men: the effects of growth hormone-releasing hormone infusion.

    Science.gov (United States)

    Gelato, M C; Oldfield, E; Loriaux, D L; Merriam, G R

    1990-09-01

    Twenty-four GH secretory patterns were studied before and during continuous infusions of GHRH in six patients with active acromegaly and in six normal adult men. GH release was episodic in both groups. Control subjects showed a normal diurnal variation in GH release, with the majority of GH released at night (2200-0800 h); mean levels were 1.5 +/- 0.4 (SE) ng/mL (day) and 4.2 +/- 0.8 ng/mL (night). Acromegalics had no diurnal variation in GH; levels were 45.3 +/- 13.7 ng/mL (day) and 39.8 +/- 12.2 ng/mL (night). Acromegalics demonstrated an increased frequency of GH pulses compared to normals (11.8 +/- 0.8 vs. 2.2 +/- 0.3/24 h). During continuous 24-h infusions of GHRH, the normal subjects continued to show a diurnal variation in GH release, but GH pulse frequency increased to a rate (11.7 +/- 1.4 pulses/24 h) very similar to that of the patients with acromegaly. In contrast, GHRH infusion did not alter the GH pulse frequency in the acromegalics. GHRH increased the mean levels of GH in both groups (patients 80.2 +/- 20.3 vs. 41.0 +/- 12.1 ng/mL, x +/- SE. P less than 0.05; controls 10.2 +/- 2.0 vs. 3.33 +/- 0.5 ng/mL, P less than 0.01). Some of the patients with acromegaly showed a progressive decline in GH levels during the infusion period, suggesting desensitization or exhaustion of releaseable stores; however, GH levels remained above basal values in all patients. After the 24-h GHRH infusions, the GH response to a bolus of GHRH was diminished in the normal subjects (2.1 +/- 0.9 vs. 16.8 +/- 5 ng/mL, x +/- SE; P less than 0.01) but not in the acromegalic patients (30.2 +/- 8.9 vs. 35.5 +/- 12.5 ng/mL; NS). These results indicate that GH release is episodic under basal conditions and during continuous GHRH infusion in both acromegalic and normal subjects, indicating the importance of other modulators of GH release, such as somatostatin, which may remain pulsatile even in acromegaly. PMID:2118536

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

    International Nuclear Information System (INIS)

    Interleukin 1α (IL-1α), a powerful endogenous pyrogen released from monocytes and macrophages by bacterial endotoxin, stimulates corticotropin, prolactin, and somatotropin release and inhibits thyrotropin release by hypothalamic action. The authors injected recombinant human IL-1α into the third cerebral ventricle, to study its effect on the pulsatile release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in conscious, freely moving, ovariectomized rats. Intraventricular injection of 0.25 pmol of IL-1α caused an almost immediate reduction of plasma LH concentration. To determine the mechanism of the suppression of LH release, mediobasal hypothalamic fragments were incubated in vitro with IL-1α (10 pM) and the release of LH-releasing hormone (LHRH) and prostaglandin E2 into the medium was measured by RIA in the presence or absence of nonrepinephrine. 1α reduced basal LHRH release and blocked LHRH release induced by nonrepinephrine. In conclusion, IL-1α suppresses LH but not FSH release by an almost complete cessation of pulsatile release of LH in the castrated rat. The mechanism of this effect appears to be by inhibition of prostaglandin E2-mediated release of LHRH

  14. The effect of non-steroidal antiandrogen flutamide on luteinizing hormone pulsatile secretion in male-to-female transsexual subjects.

    Science.gov (United States)

    Giusti, M; Falivene, M R; Carraro, A; Cuttica, C M; Valenti, S; Giordano, G

    1995-06-01

    We evaluated LH pulsatile patterns before and 4 weeks after the oral administration of flutamide (750 mg/day) in 9 male-to-female transsexuals (age range 17-28 yr) requesting gender reassignment. Flutamide was given to explore the feedback role of androgens on the LHRH-LH unit in LH pulsatility in transsexuals. Seven normal age-matched men served as a control group, without receiving flutamide, due to ethical considerations. LH pulsatility was evaluated on samples collected every 15 min for 360 min. FSH, PRL, cortisol, SHBG and sex steroids were evaluated on pooled samples. LH pulses were analyzed by the Santen and Bardin algorithm, slightly modified. No differences in FSH, PRL, total- or free-testosterone, estradiol and SHBG levels were noted between transsexuals and controls. Normal circadian cortisol decline was observed in all subjects. Mean LH levels (p < 0.05) and LH pulses (p < 0.01) were significantly lower in transsexuals. Flutamide induced an increase in mean LH and testosterone levels (p < 0.01). After flutamide administration there was an increase in LH pulse frequency (P < 0.01) and the frequency and amplitude of LH pulses in transsexuals were restored to levels observed in controls. No differences in FSH, PRL or estradiol levels were found after flutamide. These data suggest that a decrease in LH pulse frequency could be an endocrine marker in male-to-female transsexuals. An increase in endogenous androgen negative feed-back could be speculated in these subjects. However, normal testosterone levels indirectly suggest that a normal that a normal qualitative LH secretion is maintained.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7594235

  15. Increased levels and pulsatility of follicle-stimulating hormone in mothers of hereditary dizygotic twins.

    Science.gov (United States)

    Lambalk, C B; Boomsma, D I; De Boer, L; De Koning, C H; Schoute, E; Popp-Snijders, C; Schoemaker, J

    1998-02-01

    According to the endocrine model of hereditary dizygotic twinning, high FSH is responsible for multiple ovulation and pregnancy. Our study explored the underlying neuroendocrine causes. In a prospective clinical study, we compared the third day of menses parameters of episodic secretion of LH and FSH, the pituitary response to LHRH, plasma estradiol, and dimeric inhibin A and B in 16 regularly menstruating and 9 postmenopausal mothers of dizygotic twins with a family history of twinning and 14 premenopausal and 9 postmenopausal controls. Seven of 16 premenopausal mothers of twins had abnormally high FSH levels of more than 10 IU/L compared with 1/14 in controls (P = 0.024). In the premenopausal mothers of twins, mean FSH concentrations (P = 0.025) and FSH pulse frequency (P = 0.003) were significantly elevated, whereas FSH pulse amplitude and FSH response to LHRH were unaltered. For LH, neither the secretory parameters nor the response to LHRH was different. There were no differences between estradiol and inhibin A and B levels. Postmenopausal mothers of twin and controls did not differ with respect to the secretory pattern of LH and FSH. We conclude that under equal ovarian feedback conditions, premenopausal mothers of a dizygotic twin have hyper stimulation by endogenous FSH caused by neuroendocrine, hypothalamic, or pituitary mechanisms. This is the result of altered responsiveness to ovarian feedback and/or pituitary or suprapituitary, non-LHRH-like mechanisms that stimulate pulsatile FSH. PMID:9467561

  16. 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 sampl

  17. Basal, But Not Pulsatile, Growth Hormone Secretion Determines the Ambient Circulating Levels of Insulin-Like Growth Factor-I

    OpenAIRE

    Faje, Alexander T.; Barkan, Ariel L.

    2010-01-01

    Context: Previous studies have shown that mean 24-h GH concentrations determine plasma IGF-I levels in patients with acromegaly. However, we have recently shown that continuous GH infusion, mimicking the interpulse GH levels, was significantly more effective than the pulsatile GH administration at increasing IGF-I concentrations.

  18. Pulsatile control of reproduction.

    Science.gov (United States)

    1984-08-18

    An aspect of the neuroendocrine regulation of reproduction to emerge in the past decade is the pulsatile nature of hormone secretion. The pulse generator is in the central nervous system -- in the medial basal region of the hypothalamus. It works by a synchronous firing of entire populations of endocrine neurons, which discharge a quantum of the decapeptide gonadotropin-releasing hormone (GnRH) into the portal blood capillaries which then carry it to the anterior pituitary gland. In man, episodic secretion of pituitary gonadotropins, especially luteinizing hormone (LH) is considered to imply a preceding pulsatile GnRH stimulus also, though this cannot be observed directly. This LH pattern is characterized by discrete bursts (pulses) separated by periods of little or no secretion. It is observalbe at all stages and states of reproductive life, being most evident at high secretion rates (e.g., at midcycle and after menopause). The pulse frequency is important and leads to the possibility of physiological and pharmacological control of pituitary-gonadal function by frequency modulation. Physiologically, pulses of LH secretion occur every 1-2 hours. The need for pulsatility in therapeutic GnRH stimulation of the pituitary also has been established following the early days of GnRH therapy when both constant and infrequent administration were found to be ineffective. Pulsatile GnRH therapy through portable pumps delivering small doses subcutaneously or intravenously every 1-2 hours has now been successfully applied to the treatment of anovulatory infertility, male hypogonadism, and the initiation of puberty. Supraphysiological GnRH stimulation, whether through increased frequency or amplitude or use of the "superactive" agonist analogues, produces a seemingly paradoxical inhibition of gonadotropin secretion. Although a postreceptor effect has been proposed, the mechanism appears to be a "down-regulation" of the GnRH receptors. Normally, the gaps between the physiological

  19. Impaired crosstalk between pulsatile insulin and glucagon secretion in prediabetic individuals

    DEFF Research Database (Denmark)

    Rohrer, Stefan; Menge, Björn A; Grüber, Lena; Deacon, Carolyn F; Schmidt, Wolfgang E; Veldhuis, Johannes D; Holst, Jens Juul; Meier, Juris J

    2012-01-01

    Postprandial hyperglucagonemia is frequently found in patients with diabetes. Recently, a loss of the inverse relationship between pulsatile insulin and glucagon secretion has been reported in patients with type 2 diabetes. The crosstalk between pulsatile islet hormone secretion in prediabetic...

  20. Objective pulsatile tinnitus

    OpenAIRE

    Yacovino, Dario A.; Casas, Pablo

    2015-01-01

    Key Clinical Message Tinnitus is the usually unwanted perception of sound, in most cases there is no genuine physical source of sound. Less than 10% of tinnitus patients suffer from pulsatile tinnitus. Objective Pulsatile tinnitus can also be the first indication of dural arteriovenous fistula, so examination for such vascular origin must be performed.

  1. 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.

  2. 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)

    Prostacyclin (PGI2) 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 PGI2 was injected and frequent samples taken thereafter. With this protocol injection of 2 μg of PGI2 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, PGI2 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 PGI2 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

  3. 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, ...

  4. Secreción pulsátil diurna de la hormona foliculo estimulante (FSH en ovejas prepúberes con y sin restriccion alimenticia Pulsatile follicle stimulating hormone (FSH secretion in prepubertal female sheep with and without food restriction

    Directory of Open Access Journals (Sweden)

    S. E. RECABARREN

    2003-12-01

    ón de LH que a una deficiencia en la secreción de FSHFood restriction delays the onset of puberty due to a low secretion of LH and probably the FSH as well. The objective of this work was to assess and to compare the diurnal pulsatile secretion of FSH in normal growing and in growth-retarded ewe lambs due to food restriction. Five Suffolk ewe lambs were fed at 2% of their body weight in two daily rations whereas the other 5 were fed ad-libitum from 20 and until 30 weeks of age and served as a control group. A FSH pulsatile study was conducted, before and after six and ten weeks of food restriction corresponding to 20, 26 and 30 weeks of age respectively. The FSH pulsatile study consisted in collecting blood samples every 10 minutes for 5 hours from 10 AM onwards. In the obtained plasma the FSH was measured by RIA. The characteristics of the pulsatile FSH secretion were assessed using the CLUSTER program. Data obtained from the CLUSTER program were analyzed with analysis of variance for repeated measures. Mean plasma FSH concentrations (ng/mL/5h increased in almost 50% in control ewe lambs between 20 and 30 weeks of age but without statistical difference. At 30 weeks of age, control lambs had a 50% higher mean plasma FSH concentrations and mean FSH pulse amplitude than food-restricted lambs. FSH pulse frequency did not show any difference between ages within a group or between groups. Results suggest that food restriction has a partial suppressor effect on the FSH secretion. The delay on the onset of puberty due to food-restriction in the ewe lamb could be attributed more to an insufficient LH secretion GnRH-stimulated than to an inadequate FSH secretion

  5. Pulsatile characteristics of spontaneous growth hormone (GH) concentration profiles in boys evaluated by an ultrasensitive immunoradiometric assay: Evidence for ultradian periodicity of GH secretion

    International Nuclear Information System (INIS)

    To investigate underlying ultradian periodicities in spontaneous circulating GH concentrations, blood samples were drawn from 15 normal short boys every 20 min over a 24-h period, and plasma GH concentrations were measured using an ultrasensitive immunoradiometric assay. The limit of detection for the GH assay was 0.01 μg/L. The GH time series were analyzed using the Cluster program, Ultra program, cosinor analysis, and autocorrelation analysis. Plasma GH concentrations in 1,095 samples derived from 15 normal short boys were all within the detectable range of the assay and ranged from 0.07-52.2 μg/L. Thirty-six percent of the GH values in the 1,095 samples from 15 normal short boys were below 1 μg/L, and 82% of them occurred during the diurnal awakening period. Cluster analysis disclosed a total of 176 peaks in 15 normal short boys, with a mean ± SEM number of significant GH peaks of 12.1 ± 0.5/24 h. Twelve percent of the 176 peaks were below 1 μg/L, and 95% of them occurred during the diurnal awakening period. In addition, Cluster analysis disclosed 161 interpulse intervals in total, with a mean ± SEM interval of 116.5 ± 4.3 min. The GH interpulse interval did not show a significant 24-h rhythm, whereas the GH peak height increased significantly at night. An independent discrete peak detection in program, Ultra, identified 12.6 ± 0.5 GH peaks/24 h. This result was in good agreement with that from analysis by the Cluster program (P = NS). Autocorrelation analysis revealed that GH time series were significantly autocorrelated in 9 of the 15 boys, with maximal autocorrelation coefficients at 115.5 min, on the average. The mean autocorrelation coefficient for a group of 15 normal short boys was significantly positive at a 100-min lag. These findings suggest that there could be a regularly occurring periodicity of approximately 100-120 min in the human GH time series. 18 refs., 4 figs., 1 tab

  6. Jointly amplified basal and pulsatile growth hormone (GH) secretion and increased process irregularity in women with anorexia nervosa: indirect evidence for disruption of feedback regulation within the GH-insulin-like growth factor I axis

    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...

  7. Efecto de melatonina sobre la secreción pulsátil de hormona luteinizante y de hormona del crecimiento en borregas con restricción alimenticia Effect of melatonin on the pulsatile luteinizing hormone and growth hormone secretion in ewe lambs under food restriction

    Directory of Open Access Journals (Sweden)

    S. E. RECABARREN

    2000-01-01

    Full Text Available El objetivo del presente trabajo fue caracterizar la secreción pulsátil de LH y GH en borregas sometidas a restricción alimenticia (n=5, grupo R-MEL, a las 20, 26 y 30 semanas de edad, tratadas diariamente con melatonina (3 mg/día, a las 16:00 h, desde las 10 semanas de edad. La restricción alimenticia se inició a las 16 semanas de edad. Borregas de la misma edad con restricción alimenticia sin administración de melatonina actuaron como grupo comparativo (n=6, R-SOL. El promedio transversal de LH tendió a aumentar desde 0,35± 0,04 a las 20 sem. hasta 0,61±0,15 ng/ml/6h a las 30 sem en las borregas del grupo R-MEL, mientras que en las borregas del grupo R-SOL el promedio no cambió entre ambas edades: 0,34± 0,03 a las 20 sem y 0,25±0,05 ng/ml/6h a las 30 sem. La frecuencia de pulsos de LH no cambió y no fue diferente entre los 2 grupos. La amplitud de pulsos de LH tendió a ser mayor en las borregas R-MEL a las 30 sem: 0,76± 0,28 y 0,38± 0,09 ng/ml respectivamente (PThe aim of the present work was to characterize the pulsatile LH and GH secretion in food restricted Suffolk ewe lambs (n=5, R-MEL group receiving daily oral administration of melatonin (3mg/20 mL, at 16:00 h, at 20-26- and 30 weeks of age, after 4,10 and 14 weeks of food restriction. Melatonin treatment was initiated at 10 weeks of age. Food restricted lambs of the same age, without melatonin treatment acted as comparative group (n=6, R-SOL. Blood samples were collected from a jugular vein by means of an indwelling catheter at 10 min-intervals for 6 hours, from 09:00 h. LH and GH were measured by radioimmunoassay. Plasma concentrations of both hormones were analyzed by the Cluster program to define pulse frequency (n° pulses/6h, and pulse amplitude (ng/mL. The transversal mean of LH and GH was also calculated (ng/mL/6h. In the R-MEL group, the transversal mean of LH tended to increase from 0.35± 0.04 in 20 weeks old lambs to 0.61± 0.15 ng/mL/6h in 30 weeks old

  8. Fractality of pulsatile flow in speckle images

    Science.gov (United States)

    Nemati, M.; Kenjeres, S.; Urbach, H. P.; Bhattacharya, N.

    2016-05-01

    The scattering of coherent light from a system with underlying flow can be used to yield essential information about dynamics of the process. In the case of pulsatile flow, there is a rapid change in the properties of the speckle images. This can be studied using the standard laser speckle contrast and also the fractality of images. In this paper, we report the results of experiments performed to study pulsatile flow with speckle images, under different experimental configurations to verify the robustness of the techniques for applications. In order to study flow under various levels of complexity, the measurements were done for three in-vitro phantoms and two in-vivo situations. The pumping mechanisms were varied ranging from mechanical pumps to the human heart for the in vivo case. The speckle images were analyzed using the techniques of fractal dimension and speckle contrast analysis. The results of these techniques for the various experimental scenarios were compared. The fractal dimension is a more sensitive measure to capture the complexity of the signal though it was observed that it is also extremely sensitive to the properties of the scattering medium and cannot recover the signal for thicker diffusers in comparison to speckle contrast.

  9. CURRENT TRENDS IN PULSATILE DRUG DELIVERY SYSTEMS

    OpenAIRE

    S. R. Tajane et al.

    2012-01-01

    The purpose for this review on pulsatile drug delivery systems (PDDS) is to compile the recent literatures with special focus on the different types and approaches involved in the development of the formulation. Pulsatile drug delivery system is the most interesting time and site-specific system. This system is designed for chronopharmacotherapy. Thus, to mimic the function of living systems and in view of emerging chronotherapeutic approaches, pulsatile delivery, which is meant to release a ...

  10. ANALYSIS OF PULSATILE FLOW IN THE PARALLEL-PLATE FLOW CHAMBER WITH SPATIAL SHEAR STRESS GRADIENT

    Institute of Scientific and Technical Information of China (English)

    QIN Kai-rong; HU Xu-qu; LIU Zhao-rong

    2007-01-01

    The Parallel-Plate Flow Chamber (PPFC), of which the height is far smaller than its own length and width, is one of the main apparatus for the in-vitro study of the mechanical behavior of cultured vascular Endothelical Cells (ECs) exposed to fluid shear stress. The steady flow in different kinds of PPFC has been extensively investigated, whereas, the pulsatile flow in the PPFC has little attention. In consideration of the characteristics of geometrical size and pulsatile flow in the PPFC, the 3-D pulsatile flow was decomposed into a 2-D pulsatile flow in the vertical plane, and an incompressible plane potential flow in the horizontal plane. A simple method was then proposed to analyze the pulsatile flow in the PPFC with spatial shear stress gradient. On the basis of the method, the pulsatile fluid shear stresses in several reported PPFCs with spatial shear stress gradients were calculated. The results were theoretically meaningful for applying the PPFCs in-vitro, to simulate the pulsatile fluid shear stress environment, to which cultured ECs were exposed.

  11. 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

  12. PULSATILE DRUG DELIVERY SYSTEM: A REVIEW

    OpenAIRE

    Jamil Faraz; Singh Arjun; Kumar Sunil; Sharma Ritika

    2012-01-01

    The purpose for this review on pulsatile drug delivery systems (PDDS) is to compile the recent literatures with special focus on the different types and approaches involved in the development of the formulation. Pulsatile drug delivery system is the most interesting time and site-specific system. Diseases wherein PDDS are promising include asthma, peptic ulcer, cardiovascular diseases, arthritis,attention deficit syndrome in children, and hypercholesterolemia. PDDS can be classified into time...

  13. 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.

  14. 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

  15. 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)

    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

  16. Film coatings for oral pulsatile release.

    Science.gov (United States)

    Maroni, Alessandra; Zema, Lucia; Loreti, Giulia; Palugan, Luca; Gazzaniga, Andrea

    2013-12-01

    Pulsatile delivery is generally intended as a release of the active ingredient that is delayed for a programmable period of time to meet particular chronotherapeutic needs and, in the case of oral administration, also target distal intestinal regions, such as the colon. Most oral pulsatile delivery platforms consist in coated formulations wherein the applied polymer serves as the release-controlling agent. When exposed to aqueous media, the coating initially performs as a protective barrier and, subsequently, undergoes a timely failure based on diverse mechanisms depending on its physico-chemical and formulation characteristics. Indeed, it may be ruptured because of the gradual expansion of the core, swell and/or erode due to the glassy-rubbery polymer transition or become permeable thus allowing the drug molecules to diffuse outwards. Otherwise, when the coating is a semipermeable membrane provided with one or more orifices, the drug is released through the latter as a result of an osmotic water influx. The vast majority of pulsatile delivery systems described so far have been prepared by spray-coating, which offers important versatility and feasibility advantages over other techniques such as press- and dip-coating. In the present article, the design, manufacturing and performance of spray-coated pulsatile delivery platforms is thus reviewed. PMID:23506956

  17. CURRENT TRENDS IN PULSATILE DRUG DELIVERY SYSTEMS

    Directory of Open Access Journals (Sweden)

    S. R. Tajane et al.

    2012-01-01

    Full Text Available The purpose for this review on pulsatile drug delivery systems (PDDS is to compile the recent literatures with special focus on the different types and approaches involved in the development of the formulation. Pulsatile drug delivery system is the most interesting time and site-specific system. This system is designed for chronopharmacotherapy. Thus, to mimic the function of living systems and in view of emerging chronotherapeutic approaches, pulsatile delivery, which is meant to release a drug following programmed lag phase, has increasing interest in the recent years. Diseases wherein PDDS are promising include asthma, peptic ulcer, cardiovascular diseases, arthritis, and attention deficit syndrome in children, cancer, diabetes, and hypercholesterolemia. Pulsatile drug delivery system divided into 2 types’ preplanned systems and stimulus induced system, preplanned systems based on osmosis, rupturable layers, and erodible barrier coatings. Stimuli induced system based on electrical, temperature and chemically induced systems. This review also summarizes some current PDDS already available in the market. These systems are useful to several problems encountered during the development of a pharmaceutical dosage form.

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

    International Nuclear Information System (INIS)

    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.

  19. Pulsatile lipid vesicles under osmotic stress

    CERN Document Server

    Chabanon, Morgan; Liedberg, Bo; Parikh, Atul N; Rangamani, Padmini

    2016-01-01

    The response of lipid bilayers to osmotic stress is an important part of cellular function. Previously, in [Oglecka et al. 2014], we reported that cell-sized giant unilamellar vesicles (GUVs) exposed to hypotonic media, respond to the osmotic assault by undergoing a cyclical sequence of swelling and bursting events, coupled to the membrane's compositional degrees of freedom. Here, we seek to deepen our quantitative understanding of the essential pulsatile behavior of GUVs under hypotonic conditions, by advancing a comprehensive theoretical model for vesicle dynamics. The model quantitatively captures our experimentally measured swell-burst parameters for single-component GUVs, and reveals that thermal fluctuations enable rate dependent pore nucleation, driving the dynamics of the swell-burst cycles. We further identify new scaling relationships between the pulsatile dynamics and GUV properties. Our findings provide a fundamental framework that has the potential to guide future investigations on the non-equili...

  20. Arterial tree asymmetry reduces cerebral pulsatility.

    Science.gov (United States)

    Vrselja, Zvonimir; Brkic, Hrvoje; Curic, Goran

    2015-11-01

    With each heartbeat, pressure wave (PW) propagates from aorta toward periphery. In cerebral circulation, at the level of circle of Willis (CW), four arteries and four PWs converge. Since the interference is an elemental property of the wave, PWs interfere at the level of CW. We hypothesize that the asymmetry of brain-supplying arteries (that join to form CW) creates phase difference between the four PWs that interfere at the level of CW and reduce downstream cerebral pulsatility. To best of our knowledge, the data about the sequence of PWs' arrival into the cerebral circulation is lacking. Evident imperfect bilateral symmetry of the vessels results with different path length of brain-supplying arteries, hence, PWs should arrive into the head at different times. The probabilistic calculation shows that asynchronous arrival is more probable than synchronous. The importance of PWs for the cerebral circulation is highlighted by the observation that barotrauma protection mechanisms are more influenced by the crest of PW (pulse pressure) than by the mean arterial pressure. In addition, an increased arterial pulsatility is associated with several brain pathologies. We created simple computational models of four converging arteries and found that asynchronous arrival of the PWs results with lower maximum pressure, slower rate of pressure amplification and lower downstream pulsatility. In analogy, the asynchronous arrival of the pressure waves into the cerebral circulation should decrease blood flow pulsatility and lower transmission of kinetic energy on arterial wall. We conclude that asynchronous arrival of PWs into the cerebral circulation influences cerebral hemodynamics and represents a physiological necessity. PMID:26277658

  1. PULSATILE DRUG DELIVERY SYSTEM: A REVIEW

    Directory of Open Access Journals (Sweden)

    Jamil Faraz

    2012-07-01

    Full Text Available The purpose for this review on pulsatile drug delivery systems (PDDS is to compile the recent literatures with special focus on the different types and approaches involved in the development of the formulation. Pulsatile drug delivery system is the most interesting time and site-specific system. Diseases wherein PDDS are promising include asthma, peptic ulcer, cardiovascular diseases, arthritis,attention deficit syndrome in children, and hypercholesterolemia. PDDS can be classified into time controlled systems wherein the drug release is controlled primarily by the delivery system; stimuli induced PDDS in which release is controlled by the stimuli, like the pH or enzymes present in the Intestinal tract or enzymes present in the drug delivery system and externally regulated system where release is programmed by external stimuli like magnetism, ultrasound, electrical effect and irradiation. Marketed product like Pulsicap®, Ritalin® and Pulsys® are based on pulsatile release system. The aim of this review is to describe several types of drug delivery systems. This review also summarizes some current PDDS already available in the market. These systems are useful to several problems encountered during the development of a pharmaceutical dosage form.

  2. Occipital artery anastomosis to vertebral artery causing pulsatile tinnitus

    OpenAIRE

    Alexander, Matthew David; English, Joey; Hetts, Steven W.

    2013-01-01

    Pulsatile tinnitus can result from various vascular etiologies that cause transmission of pulsatile turbulent flow into the inner ear. Less commonly, non-vascular sources cause increased blood flow and transmission of sound perceived as tinnitus. Thorough clinical examination leads to appropriate imaging evaluation and therapeutic planning. Most pulsatile tinnitus results from expected mechanisms, such as dural arteriovenous fistula, jugular bulb dehiscence, or paraganglioma; however, the lit...

  3. Microprocessor-controlled pulsatile flow loop for hemodynamic studies.

    Science.gov (United States)

    Lynch, T G; Hobson, R W; Pawel, H E

    1986-03-01

    Validation of spectral analytic techniques in the clinical assessment and quantitation of vascular stenoses has been aided by use of in vitro flow loops. We have used a recently developed microprocessor-controlled pulsatile flow model to examine the influence of varying stenoses on Doppler-shifted peak systolic frequencies. A nonaxisymmetric, vertically oriented stenosis was produced by extrinsic compression of latex rubber tubing 12 mm in diameter, reducing the cross-sectional area (CSA) by 25, 40, 50, 60, 70, 85, and 97%. A rolling diaphragm pump, driven through a slider-crank mechanism by a microprocessor-controlled stepper motor, generated characteristic arterial pulse waves at a rate of 75 cycles per minute. Using an 8 MHz, continuous-wave, directional Doppler velocimeter, the Doppler-shifted frequencies were recorded at the stenosis. Four sets of observations were made at each of the stenoses, and the peak systolic frequency (PSF) was determined using a spectrum analyzer. The PSF in the absence of an obstructing stenosis was 2.56 +/- 0.03 (KHz +/- SEM). This increased significantly (P less than 0.05) to 4.80 +/- 0.09 when the CSA was reduced by 50%, to 5.90 +/- 0.37 when the CSA was reduced by 60% (P less than 0.05), to 8.40 +/- 0.10 when the CSA was reduced by 70% (P less than 0.05), and to 17.84 +/- 0.89 when the CSA was reduced by 85% (P less than 0.05). These data establish the utility of this pulsatile flow model, confirming the direct relationship between the Doppler-shifted PSF and the percentage reduction in CSA.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3951221

  4. Slip Effects on Pulsatile Flow of Blood through a Stenosed Arterial Segment under Periodic Body Acceleration

    OpenAIRE

    Sinha, A; Shit, G. C.; Kundu, P.K.

    2013-01-01

    A theoretical investigation concerning the influence of externally imposed periodic body acceleration on the flow of blood through a time-dependent stenosed arterial segment by taking into account the slip velocity at the wall of the artery has been carried out. A mathematical model is developed by treating blood as a non-Newtonian fluid obeying the Casson fluid model. The pulsatile flow is analyzed by considering a periodic pressure gradient and the inertial effects as negligibly small. A su...

  5. Decreased hypothalamic growth hormone-releasing hormone content and pituitary responsiveness in hypothyroidism.

    OpenAIRE

    Katakami, H; Downs, T R; Frohman, L A

    1986-01-01

    The effects of thyroidectomy (Tx) and thyroxine replacement (T4Rx) on pituitary growth hormone (GH) secretion and hypothalamic GH-releasing hormone (GRH) concentration were compared to define the mechanism of hypothyroid-associated GH deficiency. Thyroidectomized rats exhibited a complete loss of pulsatile GH secretion with extensive reduction in GRH responsiveness and pituitary GH content. Cultured pituitary cells from Tx rats exhibited reduced GRH sensitivity, maximal GH responsiveness, and...

  6. Occipital artery anastomosis to vertebral artery causing pulsatile tinnitus.

    Science.gov (United States)

    Alexander, Matthew David; English, Joey; Hetts, Steven W

    2014-03-01

    Pulsatile tinnitus can result from various vascular etiologies that cause transmission of pulsatile turbulent flow into the inner ear. Less commonly, non-vascular sources cause increased blood flow and transmission of sound perceived as tinnitus. Thorough clinical examination leads to appropriate imaging evaluation and therapeutic planning. Most pulsatile tinnitus results from expected mechanisms, such as dural arteriovenous fistula, jugular bulb dehiscence, or paraganglioma; however, the literature contains reports of numerous rare causes, particularly variant anatomic morphologies. We present the case of a novel cause of pulsatile tinnitus in which collateral vascular flow compensated for decreased normal intracranial cerebral arterial supply and might have caused catastrophic consequences if intervened upon after assumptions based on an incomplete evaluation. PMID:23493341

  7. ORAL MULTIPARTICULATE PULSATILE DRUG DELIVERY SYSTEMS: A REVIEW

    OpenAIRE

    Shaji Jessy; Shinde Amol B

    2011-01-01

    Pulsatile drug delivery aims to release drugs in a planned pattern i.e. at appropriate time and/or at a suitable site of action. Pharmaceutical invention and research are increasingly focusing on delivery systems which enhance desirable therapeutic objectives while minimising side effects. However, in recent pharmaceutical applications involving pulsatile delivery, multiparticulate dosage forms are gaining much favour over single-unit dosage forms because of their potential benefits like pred...

  8. Pulsatile ocular blood flow in subjects with sleep apnoea syndrome

    OpenAIRE

    Nowak, Michal S.; Jurowski, Piotr; Gos, Roman; Prost, Marek E.; Smigielski, Janusz

    2011-01-01

    Introduction The aim of the study was to determine the correlation between pulsatile ocular blood flow (POBF) and sleep apnoea syndrome (SAS). Material and methods Patients were recruited from those who underwent polysomnography in the “Sleep Unit” of the physiology department (Medical University, Lodz, Poland). A total of 52 Caucasian patients, 34 with SAS and 18 age- and gender-matched controls, were included in the study. Comprehensive ophthalmic examination included the pulsatile ocular b...

  9. Optimization studies on compression coated floating-pulsatile drug delivery of bisoprolol.

    Science.gov (United States)

    Jagdale, Swati C; Bari, Nilesh A; Kuchekar, Bhanudas S; Chabukswar, Aniruddha R

    2013-01-01

    The purpose of the present work was to design and optimize compression coated floating pulsatile drug delivery systems of bisoprolol. Floating pulsatile concept was applied to increase the gastric residence of the dosage form having lag phase followed by a burst release. The prepared system consisted of two parts: a core tablet containing the active ingredient and an erodible outer shell with gas generating agent. The rapid release core tablet (RRCT) was prepared by using superdisintegrants with active ingredient. Press coating of optimized RRCT was done by polymer. A 3² full factorial design was used for optimization. The amount of Polyox WSR205 and Polyox WSR N12K was selected as independent variables. Lag period, drug release, and swelling index were selected as dependent variables. Floating pulsatile release formulation (FPRT) F13 at level 0 (55 mg) for Polyox WSR205 and level +1 (65 mg) for Polyox WSR N12K showed lag time of 4 h with >90% drug release. The data were statistically analyzed using ANOVA, and P < 0.05 was statistically significant. Release kinetics of the optimized formulation best fitted the zero order model. In vivo study confirms burst effect at 4 h in indicating the optimization of the dosage form. PMID:24367788

  10. Optimization Studies on Compression Coated Floating-Pulsatile Drug Delivery of Bisoprolol

    Directory of Open Access Journals (Sweden)

    Swati C. Jagdale

    2013-01-01

    Full Text Available The purpose of the present work was to design and optimize compression coated floating pulsatile drug delivery systems of bisoprolol. Floating pulsatile concept was applied to increase the gastric residence of the dosage form having lag phase followed by a burst release. The prepared system consisted of two parts: a core tablet containing the active ingredient and an erodible outer shell with gas generating agent. The rapid release core tablet (RRCT was prepared by using superdisintegrants with active ingredient. Press coating of optimized RRCT was done by polymer. A 32 full factorial design was used for optimization. The amount of Polyox WSR205 and Polyox WSR N12K was selected as independent variables. Lag period, drug release, and swelling index were selected as dependent variables. Floating pulsatile release formulation (FPRT F13 at level 0 (55 mg for Polyox WSR205 and level +1 (65 mg for Polyox WSR N12K showed lag time of 4 h with >90% drug release. The data were statistically analyzed using ANOVA, and P<0.05 was statistically significant. Release kinetics of the optimized formulation best fitted the zero order model. In vivo study confirms burst effect at 4 h in indicating the optimization of the dosage form.

  11. 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

  12. Mathematical modeling of fluid dynamics in pulsatile cardiopulmonary bypass.

    Science.gov (United States)

    Pennati, Giancarlo; Fiore, Gianfranco B; Laganà, Katia; Fumero, Roberto

    2004-02-01

    The design criteria of an extracorporeal circuit suitable for pulsatile flow are quite different and more entangled than for steady flow. The time and costs of the design process could be reduced if mutual influences between the pulsatile pump and other extracorporeal devices were considered without experimental trial-and-error activities. With this in mind, we have developed a new lumped-parameter mathematical model of the hydraulic behavior of the arterial side of an extracorporeal circuit under pulsatile flow conditions. Generally, components feature a resistant-inertant-compliant behavior and the most relevant nonlinearities are accounted for. Parameter values were derived either by experimental tests or by analytical analysis. The pulsatile pump is modeled as a pure pulsatile flow generator. Model predictions were compared with flow rate and pressure tracings measured during hydraulic tests on two different circuits at various flow rates and pulse frequencies. The normalized root mean square error did not exceed 24% and the model accurately describes the changes that occur in the basic features of the pressure and flow wave propagating from the pulsatile pump to the arterial cannula. PMID:14961960

  13. Optimum Heart Rate to Minimize Pulsatile External Cardiac Power

    Science.gov (United States)

    Pahlevan, Niema; Gharib, Morteza

    2011-11-01

    The workload on the left ventricle is composed of steady and pulsatile components. Clinical investigations have confirmed that an abnormal pulsatile load plays an important role in the pathogenesis of left ventricular hypertrophy (LVH) and progression of LVH to congestive heart failure (CHF). The pulsatile load is the result of the complex dynamics of wave propagation and reflection in the compliant arterial vasculature. We hypothesize that aortic waves can be optimized to reduce the left ventricular (LV) pulsatile load. We used an in-vitro experimental approach to investigate our hypothesis. A unique hydraulic model was used for in-vitro experiments. This model has physical and dynamical properties similar to the heart-aorta system. Different compliant models of the artificial aorta were used to test the hypothesis under various aortic rigidities. Our results indicate that: i) there is an optimum heart rate that minimizes LV pulsatile power (this is in agreement with our previous computational study); ii) introducing an extra reflection site at the specific location along the aorta creates constructive wave conditions that reduce the LV pulsatile power.

  14. Growth Hormone

    Science.gov (United States)

    ... page: Was this page helpful? Also known as: GH; Human Growth Hormone; HGH; Somatotropin; Growth Hormone Stimulation Test; Growth Hormone ... I should know? How is it used? Growth hormone (GH) testing is primarily used to identify growth hormone ...

  15. Pulsatile blood flow in Abdominal Aortic Aneurysms

    Science.gov (United States)

    Salsac, Anne-Virginie; Lasheras, Juan C.; Singel, Soeren; Varga, Chris

    2001-11-01

    We discuss the results of combined in-vitro laboratory measurements and clinical observations aimed at determining the effect that the unsteady wall shear stresses and the pressure may have on the growth and eventual rupturing of an Abdominal Aortic Aneurysm (AAA), a permanent bulging-like dilatation occurring near the aortic bifurcation. In recent years, new non-invasive techniques, such as stenting, have been used to treat these AAAs. However, the development of these implants, aimed at stopping the growth of the aneurysm, has been hampered by the lack of understanding of the effect that the hemodynamic forces have on the growth mechanism. Since current in-vivo measuring techniques lack the precision and the necessary resolution, we have performed measurements of the pressure and shear stresses in laboratory models. The models of the AAA were obtained from high resolution three-dimensional CAT/SCANS performed in patients at early stages of the disease. Preliminary DPIV measurements show that the pulsatile blood flow discharging into the cavity of the aneurysm leads to large spikes of pressure and wall shear stresses near and around its distal end, indicating a possible correlation between the regions of high wall shear stresses and the observed location of the growth of the aneurysm.

  16. Evaluating microcirculation by pulsatile laser Doppler signal

    Science.gov (United States)

    Chao, P. T.; Jan, M. Y.; Hsiu, H.; Hsu, T. L.; Wang, W. K.; Wang, Y. Y. Lin

    2006-02-01

    Laser Doppler flowmetry (LDF) is a popular method for monitoring the microcirculation, but it does not provide absolute measurements. Instead, the mean flux response or energy distribution in the frequency domain is generally compared before and after stimulus. Using the heartbeat as a trigger, we investigated whether the relation between pressure and flux can be used to discriminate different microcirculatory conditions. We propose the following three pulsatile indices for evaluating the microcirculation condition from the normalized pressure and flux segment with a synchronized-averaging method: peak delay time (PDT), pressure rise time and flux rise time (FRT). The abdominal aortic blood pressure and renal cortex flux (RCF) signals were measured in spontaneously hypertensive rats (SHR) and Wistar Kyoto rats (WKY). The mean value of the RCF did not differ between SHR and WKY. However, the PDT was longer in SHR (87.14 ± 5.54 ms, mean ± SD) than in WKY (76.92 ± 2.62 ms; p discriminate RCF signals that cannot be discriminated using traditional methods.

  17. Secreción pulsátil diurna y nocturna de hormona del crecimiento en ovejas prepúberes con y sin restricción alimentaria Diurnal and nocturnal pulsatile growth hormone secretion in ewe lambs with and without food restriction

    Directory of Open Access Journals (Sweden)

    S.E. RECABARREN

    1998-01-01

    Full Text Available Estudios sobre las características de la secreción pulsátil ultradiana de GH en la borrega en crecimiento son escasos, y en particular, respecto de posibles diferencias entre la secreción diurna y nocturna, y si la restricción alimentaria es capaz de modificar los patrones de secreción pulsátil. En el presente estudio se comparó la frecuencia y la amplitud de pulsos de hormona del crecimiento (GH diurnos y nocturnos durante el desarrollo prepuberal de borregas Suffolk con y sin restricción alimentaria Para ello, se realizaron estudios de pulsatilidad de GH a las 20, 26 y 30 semanas de edad, en borregas sometidas a restricción alimentaria (GR por 5, 11 y 15 semanas. Borregas de la misma edad sirvieron de control (GC. El estudio de pulsatilidad de GH se repitió en las borregas GR luego de 2 semanas de realimentación. El estudio de pulsatilidad de GH consistió en la colección de muestras de sangre desde la vena yugular cada 10 min por seis horas desde las 08:00 h para la determinación de la pulsatilidad diurna y desde las 20:00 h para la pulsatilidad nocturna. La definición de las características de la secreción pulsátil de GH se obtuvo con el programa CLUSTER. La concentración promedio (ng/ml, la amplitud de pulsos (ng/ml y la frecuencia de pulsos (nº de pulsos/6h diurna fue similar a la nocturna tanto en las borregas GC como en las borregas GR, en las 3 edades estudiadas. Aunque los parámetros de secreción diurnos y nocturnos fueron iguales entre sí en cada grupo, la concentración promedio diurna y nocturna del grupo GR fue siempre mayor (p The aim of the study was to characterise and to compare diurnal (D and nocturnal (N GH secretion in normal growing and in food-restricted Suffolk ewe lambs. Pulsatile GH secretion was studied in 6, 20, 26 and 30 week-old lambs (group GC and in six other lambs of the same age, after 5, 11 and 15 weeks of food restriction (group GR. At the end of the food restriction period, GR lambs

  18. Entrainment and thrust augmentation in pulsatile ejector flows

    Science.gov (United States)

    Sarohia, V.; Bernal, L.; Bui, T.

    1981-01-01

    This study comprised direct thrust measurements, flow visualization by use of a spark shadowgraph technique, and mean and fluctuating velocity measurements with a pitot tube and linearized constant temperature hot-wire anemometry respectively. A gain in thrust of as much as 10 to 15% was observed for the pulsatile ejector flow as compared to the steady flow configuration. From the velocity profile measurements, it is concluded that this enhanced augmentation for pulsatile flow as compared to a nonpulsatile one was accomplished by a corresponding increased entrainment by the primary jet flow. It is also concluded that the augmentation and total entrainment by a constant area ejector critically depends upon the inlet geometry of the ejector. Experiments were performed to evaluate the influence of primary jet to ejector area ratio, ejector length, and presence of a diffuser on pulsatile ejector performance.

  19. 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.

  20. 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.)

  1. 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

  2. Neuroendocrine Regulation of Growth Hormone Secretion.

    Science.gov (United States)

    Steyn, Frederik J; Tolle, Virginie; Chen, Chen; Epelbaum, Jacques

    2016-01-01

    This article reviews the main findings that emerged in the intervening years since the previous volume on hormonal control of growth in the section on the endocrine system of the Handbook of Physiology concerning the intra- and extrahypothalamic neuronal networks connecting growth hormone releasing hormone (GHRH) and somatostatin hypophysiotropic neurons and the integration between regulators of food intake/metabolism and GH release. Among these findings, the discovery of ghrelin still raises many unanswered questions. One important event was the application of deconvolution analysis to the pulsatile patterns of GH secretion in different mammalian species, including Man, according to gender, hormonal environment and ageing. Concerning this last phenomenon, a great body of evidence now supports the role of an attenuation of the GHRH/GH/Insulin-like growth factor-1 (IGF-1) axis in the control of mammalian aging. © 2016 American Physiological Society. Compr Physiol 6:687-735, 2016. PMID:27065166

  3. Augmentation of abdominal organ perfusion during cardiopulmonary bypass with a novel intra-aortic pulsatile catheter pump

    NARCIS (Netherlands)

    Gu, YJ; De Kroon, T; Elstrodt, JM; van Oeveren, W; Boonstra, PW; Rakhorst, G

    2005-01-01

    Background: Current pulsatile pumps for cardiopulmonary bypass (CPB) are far from satisfactory because of the poor pulsatility. This study was undertaken to examine the efficiency of a novel pulsatile catheter pump on pulsatility and its effect on abdominal organ perfusion during CPB. Methods: Twelv

  4. Frequency-Dependent Neural Activity in Patients with Unilateral Vascular Pulsatile Tinnitus

    Directory of Open Access Journals (Sweden)

    Han Lv

    2016-01-01

    Full Text Available Previous resting-state functional magnetic resonance imaging (rs-fMRI studies have shown that neurological changes are important findings in vascular pulsatile tinnitus (PT patients. Here, we utilized rs-fMRI to measure the amplitude of low-frequency fluctuations (ALFF in forty patients with unilateral PT and forty age-, gender-, and education-matched normal control subjects. Two different frequency bands (slow-4, 0.027–0.073 Hz, and slow-5, 0.010–0.027 Hz, which are more sensitive to subcortical and cortical neurological signal changes, resp. were analyzed to examine the intrinsic brain activity in detail. Compared to controls, PT patients had increased ALFF values mainly in the PCu, bilateral IPL (inferior parietal lobule, left IFG (inferior frontal gyrus, and right IFG/anterior insula and decreased ALFF values in the multiple occipital areas including bilateral middle-inferior occipital lobe. For the differences of the two frequency bands, widespread ALFF differences were observed. The ALFF abnormalities in aMPFC/ACC, PCu, right IPL, and some regions of occipital and parietal cortices were greater in the slow-5 band compared to the slow-4 band. Additionally, the THI score of PT patients was positively correlated with changes in slow-5 and slow-4 band in PCu. Pulsatile tinnitus is a disease affecting the neurological activities of multiple brain regions. Slow-5 band is more sensitive in detecting the alternations. Our results also indicated the importance of pathophysiological investigations in patients with pulsatile tinnitus in the future.

  5. Frequency-Dependent Neural Activity in Patients with Unilateral Vascular Pulsatile Tinnitus.

    Science.gov (United States)

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

    2016-01-01

    Previous resting-state functional magnetic resonance imaging (rs-fMRI) studies have shown that neurological changes are important findings in vascular pulsatile tinnitus (PT) patients. Here, we utilized rs-fMRI to measure the amplitude of low-frequency fluctuations (ALFF) in forty patients with unilateral PT and forty age-, gender-, and education-matched normal control subjects. Two different frequency bands (slow-4, 0.027-0.073 Hz, and slow-5, 0.010-0.027 Hz, which are more sensitive to subcortical and cortical neurological signal changes, resp.) were analyzed to examine the intrinsic brain activity in detail. Compared to controls, PT patients had increased ALFF values mainly in the PCu, bilateral IPL (inferior parietal lobule), left IFG (inferior frontal gyrus), and right IFG/anterior insula and decreased ALFF values in the multiple occipital areas including bilateral middle-inferior occipital lobe. For the differences of the two frequency bands, widespread ALFF differences were observed. The ALFF abnormalities in aMPFC/ACC, PCu, right IPL, and some regions of occipital and parietal cortices were greater in the slow-5 band compared to the slow-4 band. Additionally, the THI score of PT patients was positively correlated with changes in slow-5 and slow-4 band in PCu. Pulsatile tinnitus is a disease affecting the neurological activities of multiple brain regions. Slow-5 band is more sensitive in detecting the alternations. Our results also indicated the importance of pathophysiological investigations in patients with pulsatile tinnitus in the future. PMID:27413554

  6. Automatic segmentation and co-registration of gated CT angiography datasets: measuring abdominal aortic pulsatility

    Science.gov (United States)

    Wentz, Robert; Manduca, Armando; Fletcher, J. G.; Siddiki, Hassan; Shields, Raymond C.; Vrtiska, Terri; Spencer, Garrett; Primak, Andrew N.; Zhang, Jie; Nielson, Theresa; McCollough, Cynthia; Yu, Lifeng

    2007-03-01

    Purpose: To develop robust, novel segmentation and co-registration software to analyze temporally overlapping CT angiography datasets, with an aim to permit automated measurement of regional aortic pulsatility in patients with abdominal aortic aneurysms. Methods: We perform retrospective gated CT angiography in patients with abdominal aortic aneurysms. Multiple, temporally overlapping, time-resolved CT angiography datasets are reconstructed over the cardiac cycle, with aortic segmentation performed using a priori anatomic assumptions for the aorta and heart. Visual quality assessment is performed following automatic segmentation with manual editing. Following subsequent centerline generation, centerlines are cross-registered across phases, with internal validation of co-registration performed by examining registration at the regions of greatest diameter change (i.e. when the second derivative is maximal). Results: We have performed gated CT angiography in 60 patients. Automatic seed placement is successful in 79% of datasets, requiring either no editing (70%) or minimal editing (less than 1 minute; 12%). Causes of error include segmentation into adjacent, high-attenuating, nonvascular tissues; small segmentation errors associated with calcified plaque; and segmentation of non-renal, small paralumbar arteries. Internal validation of cross-registration demonstrates appropriate registration in our patient population. In general, we observed that aortic pulsatility can vary along the course of the abdominal aorta. Pulsation can also vary within an aneurysm as well as between aneurysms, but the clinical significance of these findings remain unknown. Conclusions: Visualization of large vessel pulsatility is possible using ECG-gated CT angiography, partial scan reconstruction, automatic segmentation, centerline generation, and coregistration of temporally resolved datasets.

  7. Frequency-Dependent Neural Activity in Patients with Unilateral Vascular Pulsatile Tinnitus

    Science.gov (United States)

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

    2016-01-01

    Previous resting-state functional magnetic resonance imaging (rs-fMRI) studies have shown that neurological changes are important findings in vascular pulsatile tinnitus (PT) patients. Here, we utilized rs-fMRI to measure the amplitude of low-frequency fluctuations (ALFF) in forty patients with unilateral PT and forty age-, gender-, and education-matched normal control subjects. Two different frequency bands (slow-4, 0.027–0.073 Hz, and slow-5, 0.010–0.027 Hz, which are more sensitive to subcortical and cortical neurological signal changes, resp.) were analyzed to examine the intrinsic brain activity in detail. Compared to controls, PT patients had increased ALFF values mainly in the PCu, bilateral IPL (inferior parietal lobule), left IFG (inferior frontal gyrus), and right IFG/anterior insula and decreased ALFF values in the multiple occipital areas including bilateral middle-inferior occipital lobe. For the differences of the two frequency bands, widespread ALFF differences were observed. The ALFF abnormalities in aMPFC/ACC, PCu, right IPL, and some regions of occipital and parietal cortices were greater in the slow-5 band compared to the slow-4 band. Additionally, the THI score of PT patients was positively correlated with changes in slow-5 and slow-4 band in PCu. Pulsatile tinnitus is a disease affecting the neurological activities of multiple brain regions. Slow-5 band is more sensitive in detecting the alternations. Our results also indicated the importance of pathophysiological investigations in patients with pulsatile tinnitus in the future. PMID:27413554

  8. Time controlled pulsatile transdermal delivery of nicotine: A phase I feasibility trial in male smokers.

    Science.gov (United States)

    Hammann, Felix; Kummer, Oliver; Guercioni, Stefania; Imanidis, Georgios; Drewe, Juergen

    2016-06-28

    Nicotine substitution is a mainstay component in smoking cessation schemes. Current products including patches are poorly effective mainly because they do not give smokers the same pharmacokinetic profile of nicotine as cigarette consumption. This work evaluates a new computer operated delivery system for time controlled pulsatile transdermal administration of nicotine in a phase I clinical trial with twelve heavy smoking male volunteers. The device was affixed to the ventral side of the leading lower arm of the subjects and was programmed to deliver two pulses of drug within 16h with three delivery rates in a consecutive dose escalation study. Tolerability of the three increasing doses of nicotine was established. Plasma concentration of nicotine exhibited two peaks and one trough and reached therapeutically effective levels that behaved linearly with the drug load concentration of the device. In vivo input rate, delivered amount and elimination kinetics were deduced by pharmacokinetic modeling to analyze device performance. Timing, dose and duration of delivery were controlled by system operation parameters. Hence, feasibility of controlled pulsatile delivery of nicotine at predetermined intervals was demonstrated. After additional optimization, preprogrammed or on demand administration to meet individualized and circadian replacement needs should improve smoking cessation efficacy. PMID:27090163

  9. Non-invasive monitoring of reproduction in male lesser mouse deer (Tragulus javanicus): Analyzing hormon testosterone and its metabolites in faeces using HPLC and enzyme immunoassay

    International Nuclear Information System (INIS)

    The lesser mouse deer (Tragulus javanicus, family Tragulidae) is a ruminant that inhabits the tropical rain forest of the South East Asia (Medway, 1969). The animal is regarded as the smallest ruminant and has been proposed to be a model in the biomedical and ruminant research (Kudo et al., 1997). On the other hand, this animal is an interesting collection in the zoo and other conservation areas for the purpose of education and tourism, showed larger proportion of carcasses and therefore suitable as an alternative meat source. Recently, the population of the lesser mouse deer is threatened by illegal hunting and habitat destruction. Therefore, conservation and management of the animal is becoming important. One success key on the conservation and breeding strategy of wild animal include the management and knowledge of the reproductive system. Only limited information are available on the reproductive physiology of the lesser mouse deer although several studies have been undertaken on the reproductive system of the male and female lesser mouse deer (Haron et al., 2000; Kimura et al., 2004; Agungpriyono et al., 2005). Previous studies on the male lesser mouse deer revealed the sperm quality (Haron et al., 2000; Agungpriyono et al., 2005), spermatozoa morphology and histochemical properties (Agungpriyono et al., 2005). Furthermore, it has also been reported that intermandibular scent gland may play important roles in the communication and sexual behaviour of mouse deer (Ralls et al., 1975; Agungpriyono et al., 2006). Attempts at natural breeding of lesser mouse deer in captive are still unsuccessful. This may be due to the lack of information about animal reproduction, both male and female of lesser mouse deer, the unstable behaviour, aggressiveness, stress and less attraction and ability to mount during the captive breeding (Haron et al 2000, Kudo et al 1997). Testosterone is the main hormone concerning the male reproductive biology that it indicates the age of

  10. Numerical computation of pulsatile flow through a locally constricted channel

    Science.gov (United States)

    Bandyopadhyay, S.; Layek, G. C.

    2011-01-01

    This paper deals with the numerical solution of a pulsatile laminar flow through a locally constricted channel. A finite difference technique has been employed to solve the governing equations. The effects of the flow parameters such as Reynolds number, flow pulsation in terms of Strouhal number, constriction height and length on the flow behaviour have been studied. It is found that the peak value of the wall shear stress has significantly changed with the variation of Reynolds numbers and constriction heights. It is also noted that the Strouhal number and constriction length have little effect on the peak value of the wall shear stress. The flow computation reveals that the peak value of the wall shear stress at maximum flow rate time in pulsatile flow situation is much larger than that due to steady flow. The constriction and the flow pulsation produce flow disturbances at the vicinity of the constriction of the channel in the downstream direction.

  11. Influence of vascular function and pulsatile hemodynamics on cardiac function.

    Science.gov (United States)

    Bell, Vanessa; Mitchell, Gary F

    2015-09-01

    Interactions between cardiac and vascular structure and function normally are optimized to ensure delivery of cardiac output with modest pulsatile hemodynamic overhead. Aortic stiffening with age or disease impairs optimal ventricular-vascular coupling, increases pulsatile load, and contributes to left ventricular (LV) hypertrophy, reduced systolic function, and impaired diastolic relaxation. Aortic pulse pressure and timing of peak systolic pressure are well-known measures of hemodynamic ventricular-vascular interaction. Recent work has elucidated the importance of direct, mechanical coupling between the aorta and the heart. LV systolic contraction results in displacement of aortic and mitral annuli, thereby producing longitudinal stretch in the ascending aorta and left atrium, respectively. Force associated with longitudinal stretch increases systolic load on the LV. However, the resulting energy stored in the elastic elements of the proximal aorta during systole facilitates early diastolic LV recoil and rapid filling. This review discusses current views on hemodynamics and mechanics of ventricular-vascular coupling. PMID:26164466

  12. Arterial Stiffness, Central Pulsatile Hemodynamic Load, and Orthostatic Hypotension.

    Science.gov (United States)

    Liu, Kai; Wang, Si; Wan, Shixi; Zhou, Yufei; Pan, Pei; Wen, Bo; Zhang, Xin; Liao, Hang; Shi, Di; Shi, Rufeng; Chen, Xiaoping; Jangala, Tulasiram

    2016-07-01

    The association between central pulsatile hemodynamic load, arterial stiffness, and orthostatic hypotension (OH) is unclear. The authors recruited 1099 participants from the community. Questionnaire, physical examination, and laboratory tests were performed. To assess the correlation between central pulsatile hemodynamic load, arterial stiffness, and OH, multiple logistic regression analysis was performed, and the discriminatory power was assessed by the area under the receiver operating curve. The prevalence of OH in this population was 5.6%. After adjusting for potential confounders, brachial-ankle pulse wave velocity (BaPWV) was significantly and positively correlated with OH in both the hypertension and nonhypertension groups (all Ppower than CSBP in both subgroups. BaPWV appears to be a better indicator of OH than CSBP in routine clinical practice. PMID:26543017

  13. INTERVENTIONAI DIAGNOSIS AND TREATMENT OF VASCULOGENEIC PULSATILE TINNITUS

    Institute of Scientific and Technical Information of China (English)

    LI Baomin; CAO Xiangyu; LIU Xinfeng; LI Sheng; WANG Jun; LIANG Yongping; GE Aili; ZHANG Alan; FENG Huimin

    2014-01-01

    Objective To retrospectively study clinical features and diagnostic imaging of vasculogeneic pulsatile tin-nitus, and the feasibility and efficacy of transvascular interventional treatment for this condition. Methods Data from 82 cases of arterial or venous pulsatile tinnitus were reviewed. DSA characteristics and possible pathophysiological mechanisms of pulsatile tinnitus in these cases were studied. Diagnoses in this group in-cluded intracranial arterovenous fistula (AVF) (n=3), spontaneous skull base dural AVF (n=16), traumatic ca-rotid-cavernous sinus fistula (n=5), subclavian artery stenosis (n=2), internal carotid artery stenosis (n=3), in-tracranial arterial stenosis (n=1), kinked and/or elongated vertebrobasilar artery (n=2), venous sinus divertic-ulum (n=2), venous sinus stenosis on the dominant drainage side (n=46) and occipital sinus stenosis (n=2). Treatments included embolization and stenting using coils, NBCA glue, Balt balloons, self-expansion stents and intracranial micro-stents via either the femoral artery or femoral vein. Results Procedures were suc-cessful in all cases with no surgery-related complications. Tinnitus disappeared within 2 days after the pro-cedure in all cases. Follow up duration was 5-36 months. Recurrence occurred in 4 cases of arterial tinnitus within 3 months following the initial procedure, which improved after revision embolization or symptom management. There was no recurrence in venous tinnitus cases following stent plastic or stent-coiling embo-lization treatments. Conclusions Endovascular intervention provides a new approach to the diagnosis and treatment of intractable pulsatile tinnitus. It is also effective in differentiating and studying other types of tinnitus.

  14. Painless pulsatile mass as first presentation of renal cell carcinoma

    OpenAIRE

    Kimberley Hoyland; Nikhil Vasdev; Paul Nathan; Damian Hanbury

    2014-01-01

    Renal cell carcinoma rarely presents with typical features of abdominal pain, flank mass and haematuria, and up to 30% of patients present with metastases. We present the case of an 81 year old man who presented with a painless, pulsatile sternal metastasis as an initial presentation of renal cell carcinoma. This case highlights the importance of recognizing even unusual presentations of renal cell carcinoma, and that although sternal metastases are rare, when they do occur there should be a ...

  15. 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.

  16. CURRENT TECHNIQUES IN PULSATILE DRUG DELIVERY: A REVIEW

    Directory of Open Access Journals (Sweden)

    RajkumarKotha

    2013-03-01

    Full Text Available The purpose of writing this review on pulsatile drug delivery system (PDDS is to compile the recent literatures with special focus on the different types and approaches involved in the development of the formulation and classification, advantages, limitation, and future aspects of pulsatile drug delivery system. PDDS is gaining a lot of interest as they deliver the drug at the right place at the right time and in the right amount, thus providing spatial and temporal delivery and increasing patient compliance. These systems are designed according to the circadian rhythm of the body. The principle rationale for the use of pulsatile release of the drugs is where a constant drug release is not desired. A pulse has to be designed in such a way that a complete and rapid drug release is achieved after a lag time. In this article, various systems like capsular systems, osmotic systems, single and multiple-unit systems based on the use of soluble or erodible polymer coating and use of rupturable membranes have been dealt. It summarizes the latest technological developments (including Wirelessly Controlled Drug-delivery MicroChip, formulation parameters, and release profiles of these systems.

  17. Pulsatile drug delivery systems: An approach for controlled drug delivery

    Directory of Open Access Journals (Sweden)

    Arora Shweta

    2006-01-01

    Full Text Available Pulsatile systems are gaining a lot of interest as they deliver the drug at the right site of action at the right time and in the right amount, thus providing spatial and temporal delivery and increasing patient compliance. These systems are designed according to the circadian rhythm of the body. The principle rationale for the use of pulsatile release is for the drugs where a constant drug release, i.e., a zero-order release is not desired. The release of the drug as a pulse after a lag time has to be designed in such a way that a complete and rapid drug release follows the lag time. Various systems like capsular systems, osmotic systems, single- and multiple-unit systems based on the use of soluble or erodible polymer coating and use of rupturable membranes have been dealt with in the article. It summarizes the latest technological developments, formulation parameters, and release profiles of these systems. Products available as once-a-daily formulation based on Pulsatile release like Pulsincap ®, Ritalin ®, and Pulsys ® are also covered in the review. These systems are beneficial for the drugs having chronopharmacological behaviour where night time dosing is required and for the drugs having high first-pass effect and having specific site of absorption in GIT. Drugs used in asthmatic patients and patients suffering from rheumatoid arthritis are also discussed along with many other examples.

  18. Child and adult vibrotactile thresholds for sinusoidal and pulsatile stimuli.

    Science.gov (United States)

    Bernstein, L E; Schechter, M B; Goldstein, M H

    1986-07-01

    Three experiments were performed to obtain vibrotactile sensitivity thresholds from hearing children and adults, and from deaf children. An adaptive two-interval forced-choice procedure was used to obtain estimates of the 70.7% point on the psychometric sensitivity curve. When hearing children of 5-6 and 9-10 years of age and adults were tested with sinusoids and haversine pulse stimuli, at 10, 100, 160, and 250 Hz or pps, respectively, only the 10-Hz stimulus resulted in an age effect. For this stimulus, young children were significantly less sensitive than adults. When sinusoids were again tested at 20, 40, 80, and 160 Hz, a small overall effect of age was observed with a significant effect only at 20 Hz. Two prelingually profoundly deaf children were tested with haversine pulse trains at 10, 50, 100, 160, and 250 pps. Both children were at least as sensitive to the tactile stimulation as were the hearing children and adults. Pulsatile stimulation, compared to sinusoidal stimulation, exhibited relatively flat threshold versus frequency functions. The present results, demonstrating no age effect for pulsatile stimulation and similar performance for deaf and hearing children, suggest that pulsatile stimulation would be appropriate in vibrotactile speech communication aids for the deaf. PMID:3745657

  19. Visualization of pulsatile flow for magnetic nanoparticle based therapies

    Science.gov (United States)

    Wentzel, Andrew; Yecko, Philip

    2015-11-01

    Pulsatile flow of blood through branched, curved, stenosed, dilated or otherwise perturbed vessels is more complex than flow through a straight, uniform and rigid tube. In some magnetic hyperthermia and magnetic chemo-therapies, localized regions of magnetic nanoparticle laden fluid are deliberately formed in blood vessels and held in place by magnetic fields. The effect of localized magnetic fluid regions on blood flow and the effect of the pulsatile blood flow on such magnetic fluid regions are poorly understood and difficult to examine in vivo or by numerical simulation. We present a laboratory model that facilitates both dye tracer and particle imaging velocimetry (PIV) studies of pulsatile flow of water through semi-flexible tubes in the presence of localized magnetic fluid regions. Results on the visualization of flows over a range of Reynolds and Womersley numbers and for several different (water-based) ferrofluids are compared for straight and curved vessels and for different magnetic localization strategies. These results can guide the design of improved magnetic cancer therapies. Support from the William H. Sandholm Program of Cooper Union's Kanbar Center for Biomedical Engineering is gratefully acknowledged.

  20. Regulatory mechanisms of growth hormone secretion are sexually dimorphic.

    OpenAIRE

    Jaffe, C A; Ocampo-Lim, B; Guo, W; Krueger, K.; Sugahara, I; DeMott-Friberg, R; Bermann, M; Barkan, A. L.

    1998-01-01

    Sexually dimorphic growth hormone (GH) secretory pattern is important in the determination of gender-specific patterns of growth and metabolism in rats. Whether GH secretion in humans is also sexually dimorphic and the neuroendocrine mechanisms governing this potential difference are not fully established. We have compared pulsatile GH secretion profiles in young men and women in the baseline state and during a continuous intravenous infusion of recombinant human insulin-like growth factor I ...

  1. Hormone assay

    International Nuclear Information System (INIS)

    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. 125I-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)

  2. Specificity of synergistic coronary flow enhancement by adenosine and pulsatile perfusion in the dog.

    Science.gov (United States)

    Pagliaro, P; Senzaki, H; Paolocci, N; Isoda, T; Sunagawa, G; Recchia, F A; Kass, D A

    1999-10-01

    1. Coronary flow elevation from enhanced perfusion pulsatility is synergistically amplified by adenosine. This study determined the specificity of this interaction and its potential mechanisms. 2. Mean and phasic coronary flow responses to increasing pulsatile perfusion were assessed in anaesthetized dogs, with the anterior descending coronary artery servoperfused to regulate real-time physiological flow pulsatility at constant mean pressure. Pulsatility was varied between 40 and 100 mmHg. Hearts ejected into the native aorta whilst maintaining stable loading. 3. Increasing pulsatility elevated mean coronary flow +11.5 +/- 1.7 % under basal conditions. Co-infusion of adenosine sufficient to raise baseline flow 66 % markedly amplified this pulsatile perfusion response (+82. 6 +/- 14.3 % increase in mean flow above adenosine baseline), due to a leftward shift of the adenosine-coronary flow response curve at higher pulsatility. Flow augmentation with pulsatility was not linked to higher regional oxygen consumption, supporting direct rather than metabolically driven mechanisms. 4. Neither bradykinin, acetylcholine nor verapamil reproduced the synergistic amplification of mean flow by adenosine and higher pulsatility, despite being administered at doses matching basal flow change with adenosine. 5. ATP-sensitive potassium (KATP) activation (pinacidil) amplified the pulse-flow response 3-fold, although this remained significantly less than with adenosine. Co-administration of the phospholipase A2 inhibitor quinacrine virtually eliminated adenosine-induced vasodilatation, yet synergistic interaction between adenosine and pulse perfusion persisted, albeit at a reduced level. 6. Thus, adenosine and perfusion pulsatility specifically interact to enhance coronary flow. This synergy is partially explained by KATP agonist action and additional non-flow-dependent mechanisms, and may be important for modulating flow reserve during exercise or other high output states where

  3. An Optimization Formulation for Characterization of Pulsatile Cortisol Secretion

    Directory of Open Access Journals (Sweden)

    Rose Taj Faghih

    2015-08-01

    Full Text Available Cortisol is released to relay information to cells to regulate metabolism and reaction to stress and inflammation. In particular, cortisol is released in the form of pulsatile signals. This low-energy method of signaling seems to be more efficient than continuous signaling. We hypothesize that there is a controller in the anterior pituitary that leads to pulsatile release of cortisol, and propose a mathematical formulation for such controller, which leads to impulse control as opposed to continuous control. We postulate that this controller is minimizing the number of secretory events that result in cortisol secretion, which is a way of minimizing the energy required for cortisol secretion; this controller maintains the blood cortisol levels within a specific circadian range while complying with the first order dynamics underlying cortisol secretion. We use an l0-norm cost function for this controller, and solve a reweighed l1-norm minimization algorithm for obtaining the solution to this optimization problem. We use 4 examples to illustrate the performance of this approach: (i a toy problem that achieves impulse control, (ii two examples that achieve physiologically plausible pulsatile cortisol release, (iii an example where the number of pulses is not within the physiologically plausible range for healthy subjects while the cortisol levels are within the desired range. This novel approach results in impulse control where the impulses and the obtained blood cortisol levels have a circadian rhythm and an ultradian rhythm that are in agreement with the known physiology of cortisol secretion. The proposed formulation is a first step in developing intermittent controllers for curing cortisol deficiency. This type of bio-inspired pulse controllers can be employed for designing non-continuous controllers in brain-machine interface design for neuroscience applications.

  4. Holographic laser Doppler imaging of pulsatile blood flow

    CERN Document Server

    Bencteux, Jeffrey; Kostas, Thomas; Bayat, Sam; Atlan, Michael

    2015-01-01

    We report on wide-field imaging of pulsatile motion induced by blood flow using heterodyne holographic interferometry on the thumb of a healthy volunteer, in real-time. Optical Doppler images were measured with green laser light by a frequency-shifted Mach-Zehnder interferometer in off-axis configuration. The recorded optical signal was linked to local instantaneous out-of-plane motion of the skin at velocities of a few hundreds of microns per second, and compared to blood pulse monitored by plethysmoraphy during an occlusion-reperfusion experiment.

  5. Pulsatile, circhoral, and circadian rhythmicity in human TSH

    International Nuclear Information System (INIS)

    In 4 healthy human (2 female, 2 male) volunteers, serum TSH was determined over 24 h in 2 min intervals. A new sensitive TSH assay was used. TSH rhythmicity was found in all volunteers and on three levels of frequency and amplitude: a circadian rhythmicity (mean frequency 2/24 h; max. amplitude 1.4 mE/l), a circhoral rhythmicity (mean frequency 10/24 h; max. amplitude 0,9 mE/l), and a 'pulsatile' rhythmicity (mean frequency 54/24 h; max. amplitude 0.4 mE/l). (orig.)

  6. Methods of measurement of the temperature field in pulsatile fluid

    Czech Academy of Sciences Publication Activity Database

    Dančová, Petra; Vít, Tomáš; Trávníček, Zdeněk; Lédl, Vít; Psota, Pavel

    New York : Begell House Inc, 2012 - (Hanjalic, K.; Nagano, Y.; Borello, D.; Jakirlic, C.), s. 263-266 ISBN 978-1-56700-301-7. [Turbulence, Heat and Mass Transfer /7./. Palermo (IT), 24.09.2012-27.09.2012] R&D Projects: GA AV ČR(CZ) IAA200760801; GA ČR(CZ) GCP101/11/J019 Institutional support: RVO:61388998 ; RVO:61389021 Keywords : pulsatile jet * temperature field * digital holography interferometry Subject RIV: BJ - Thermodynamics; BH - Optics, Masers, Lasers (UFP-V)

  7. CASE SERIES : PULSATILE LOWER LIMB VEINS - HAVE A LOOK AT THE HEART

    OpenAIRE

    Rupesh Mandava; Ritesh Santosham; Rajiv Santosham; Roy Santosham; Rajan Santosham

    2015-01-01

    Respiratory phasic variation is a normal phenomenon in the lower limb veins. Whenever there is evidence of a pulsatile flow or a positive wave seen above the baseline it calls for evaluation of the cardiovascular system. We present three cases of pulsatile wave form in the lower limb veins that had cardiac pathologies

  8. Pulsatile Delivery of Clarithromycin Alone or in Combination with Amoxicillin against Streptococcus pneumoniae

    OpenAIRE

    Leuthner, Kimberly D.; Cheung, Chrissy M.; Rybak, Michael J.

    2006-01-01

    We evaluated pulsatile dosing of clarithromycin and amoxicillin alone or combined against Streptococcus pneumoniae with various susceptibilities. When combined, pulsatile amoxicillin with clarithromycin was superior to either 8- or 12-h dosing against the intermediate strain and was identical for the susceptible strain. Pulse dosing of antimicrobials warrants further investigation.

  9. Automatic Germination Evaluation and Qualitative Analysis of Essential Oil of Mentha × piperita L. under the Influence of High Frequency Pulsatile Electromagnetic and Ultrasound Pulsatile Fields

    Directory of Open Access Journals (Sweden)

    Valentin SINGUREANU

    2015-04-01

    Full Text Available The study illustrates the influence of high frequency pulsatile electromagnetic fields and ultrasound pulsatile fields on Mentha × piperita L. seed germination and the quality of its essential oil. The physiological role of the above mentioned experimental factors was considered to be a catalyticall base point, improving germination percent, SVI (seedling vigor index, GVI (germination velocity index. All the biometric aspects of the germination process (seed area, seed perimeter, seed development on x and y radius, radicele length, hypocotyl length where determined using open free software, consolidating the general idea that scientific communities can improve and perfect open source projects. High frequency pulsatile electromagnetic fields (91.75% and ultrasound pulsatile fields (64.75% experimental variants gave higher germination percent compared to control (47.00%. Following the main terpenes determination, the same experimental variants obtained high accumulations of menthol, eugenol, thymol, eucalyptol, linalool and other components. These aspects can be scientifically sustained by the seedling vigor index marks obtained at high frequency pulsatile electromagnetic fields (1985.47 and ultrasound pulsatile fields (1480.09, creating the general premises for better development stages in the nursery sector. Raised accumulation of main therapeutical terpenes in Mentha × piperita L. must be supervised in further studies, when microscopically imagery of glandular trichomes and their density may lead to more profound conclusions.

  10. Fluid-structure interaction for nonlinear response of shells conveying pulsatile flow

    Science.gov (United States)

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

    2016-06-01

    Circular cylindrical shells with flexible boundary conditions conveying pulsatile flow and subjected to pulsatile pressure are investigated. The equations of motion are obtained based on the nonlinear Novozhilov shell theory via Lagrangian approach. The flow is set in motion by a pulsatile pressure gradient. The fluid is modeled as a Newtonian pulsatile flow and it is formulated using a hybrid model that contains the unsteady effects obtained from the linear potential flow theory and the pulsatile viscous effects obtained from the unsteady time-averaged Navier-Stokes equations. A numerical bifurcation analysis employs a refined reduced order model to investigate the dynamic behavior. The case of shells containing quiescent fluid subjected to the action of a pulsatile transmural pressure is also addressed. Geometrically nonlinear vibration response to pulsatile flow and transmural pressure are here presented via frequency-response curves and time histories. The vibrations involving both a driven mode and a companion mode, which appear due to the axial symmetry, are also investigated. This theoretical framework represents a pioneering study that could be of great interest for biomedical applications. In particular, in the future, a more refined model of the one here presented will possibly be applied to reproduce the dynamic behavior of vascular prostheses used for repairing and replacing damaged and diseased thoracic aorta in cases of aneurysm, dissection or coarctation. For this purpose, a pulsatile time-dependent blood flow model is here considered by applying physiological waveforms of velocity and pressure during the heart beating period. This study provides, for the first time in literature, a fully coupled fluid-structure interaction model with deep insights in the nonlinear vibrations of circular cylindrical shells subjected to pulsatile pressure and pulsatile flow.

  11. Pulsatile Drug Delivery System: Method and Technology Review

    Directory of Open Access Journals (Sweden)

    Kumar Amit

    2012-12-01

    Full Text Available Traditionally, drugs are released in an immediate or extended manner. A pulsatile drug release, where the drug is released rapidly after a well defined lag-time, could be advantageous for many drugs or therapies. As the pulsatile drug delivery achieve desired therapeutic effect and reducing side effect, so patient compliance can be obtained along with lowering dose frequency. These systems are designed according to the circadian rhythm of the body and the drug is released as a pulse. Diseases like asthma, peptic ulcers, cardiovascular ailments, arthritis and attention deficit syndrome in children and hypercholesterolemia can be cured by drugs, released by PDDS. Recent trends include Multiparticulate drug delivery systems that are especially suitable for achieving controlled or delayed release oral formulations with low risk of dose dumping, flexibility of blending to attain different release patterns as well as reproducible and short gastric residence time. Various methods and marketed technologies of PDDS such as Pulsincap TM, Diffucaps, CODAS, OROS and PULSYSTM are covered in this review.

  12. Cinematics and sticking of heart valves in pulsatile flow test.

    Science.gov (United States)

    Köhler, J; Wirtz, R

    1991-05-01

    The aim of the project was to develop laboratory test devices for studies of the cinematics and sticking behaviour of technical valve protheses. The second step includes testing technical valves of different types and sizes under static and dynamic conditions. A force-deflection balance was developed in order to load valve rims by static radial forces until sticking or loss of a disc (sticking- and clamping-mould point) with computer-controlled force deflection curves. A second deflection device was developed and used for prosthetic valves in the aortic position of a pulsatile mock circulation loop with simultaneous video-cinematography. The stiffness of technical valve rims varied between 0.20 (St. Jude) and about 1.0 N/micron (metal rim valves). The stiffness decreased significantly with increasing valve size. Sticking under pulsatile flow conditions was in good agreement with the static deflection measurements. Hence, valve sticking with increasing danger of thrombus formation is more likely with a less stiff valve rim. In the case of forces acting perpendicularly to the pendulum axis, the clamping mould-point of the valve can be reached, followed by disc dislodgement. PMID:1864654

  13. Predictable pulsatile release of tramadol hydrochloride for chronotherapeutics of arthritis.

    Science.gov (United States)

    Dabhi, Chandu; Randale, Shivsagar; Belgamwar, Veena; Gattani, Surendra; Tekade, Avinash

    2010-07-01

    The present investigation deals with the development of a pH and time-dependent press-coated pulsatile drug delivery system for delivering drugs into the colon. The system consists of a drug containing core, coated by a combination of natural polymer Delonix regia gum (DRG) and hydroxypropyl methylcellulose (HPMC K4M) in various proportions, which controls the onset of release. The whole system was coated with methacrylic acid copolymers, which not only prevents the drug release in the stomach, but also prolongs the lag time. Tramadol HCl was used as a model drug and varying combinations of DRG and HPMC K4M were used to achieve the desired lag time before rapid and complete release of the drug in the colon. It was observed that the lag time depends on the coating ratio of DRG to HPMC and also on press coating weight. Drug release was found to be increased by 15-30% in the presence of colonic microbial flora. The results showed the capability of the system in achieving pulsatile release for a programmable period of time and pH-dependent release to attain colon-targeted delivery. PMID:20524906

  14. Prediction and control of neural responses to pulsatile electrical stimulation

    Science.gov (United States)

    Campbell, Luke J.; Sly, David James; O'Leary, Stephen John

    2012-04-01

    This paper aims to predict and control the probability of firing of a neuron in response to pulsatile electrical stimulation of the type delivered by neural prostheses such as the cochlear implant, bionic eye or in deep brain stimulation. Using the cochlear implant as a model, we developed an efficient computational model that predicts the responses of auditory nerve fibers to electrical stimulation and evaluated the model's accuracy by comparing the model output with pooled responses from a group of guinea pig auditory nerve fibers. It was found that the model accurately predicted the changes in neural firing probability over time to constant and variable amplitude electrical pulse trains, including speech-derived signals, delivered at rates up to 889 pulses s-1. A simplified version of the model that did not incorporate adaptation was used to adaptively predict, within its limitations, the pulsatile electrical stimulus required to cause a desired response from neurons up to 250 pulses s-1. Future stimulation strategies for cochlear implants and other neural prostheses may be enhanced using similar models that account for the way that neural responses are altered by previous stimulation.

  15. Increasing pulmonary artery pulsatile flow improves hypoxic pulmonary hypertension in piglets.

    Science.gov (United States)

    Courboulin, Audrey; Kang, Chantal; Baillard, Olivier; Bonnet, Sebastien; Bonnet, Pierre

    2015-01-01

    Pulmonary arterial hypertension (PAH) is a disease affecting distal pulmonary arteries (PA). These arteries are deformed, leading to right ventricular failure. Current treatments are limited. Physiologically, pulsatile blood flow is detrimental to the vasculature. In response to sustained pulsatile stress, vessels release nitric oxide (NO) to induce vasodilation for self-protection. Based on this observation, this study developed a protocol to assess whether an artificial pulmonary pulsatile blood flow could induce an NO-dependent decrease in pulmonary artery pressure. One group of piglets was exposed to chronic hypoxia for 3 weeks and compared to a control group of piglets. Once a week, the piglets underwent echocardiography to assess PAH severity. At the end of hypoxia exposure, the piglets were subjected to a pulsatile protocol using a pulsatile catheter. After being anesthetized and prepared for surgery, the jugular vein of the piglet was isolated and the catheter was introduced through the right atrium, the right ventricle and the pulmonary artery, under radioscopic control. Pulmonary artery pressure (PAP) was measured before (T0), immediately after (T1) and 30 min after (T2) the pulsatile protocol. It was demonstrated that this pulsatile protocol is a safe and efficient method of inducing a significant reduction in mean PAP via an NO-dependent mechanism. These data open up new avenues for the clinical management of PAH. PMID:25993379

  16. Pulsatile Drug Delivery System Based on Electrohydrodynamic Method

    CERN Document Server

    Zheng, Yi; Hu, Junqiang; Gao, Wenle

    2012-01-01

    Electrohydrodynamic (EHD) generation, a commonly used method in BioMEMS, plays a significant role in the pulsatile drug delivery system for a decade. In this paper, an EHD based drug delivery system is well designed, which can be used to generate a single drug droplet as small as 2.83 nL in 8.5 ms with a total device of 2\\times2\\times3 mm^3, and an external supplied voltage of 1500 V. Theoretically, we derive the expressions for the size and the formation time of a droplet generated by EHD method, while taking into account the drug supply rate, properties of liquid, gap between two electrodes, nozzle size, and charged droplet neutralization. This work proves a repeatable, stable and controllable droplet generation and delivery system based on EHD method experimentally as well as theoretically.

  17. 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

  18. The pulsatility volume index: an indicator of cerebrovascular compliance based on fast magnetic resonance imaging of cardiac and respiratory pulsatility.

    Science.gov (United States)

    Bianciardi, Marta; Toschi, Nicola; Polimeni, Jonathan R; Evans, Karleyton C; Bhat, Himanshu; Keil, Boris; Rosen, Bruce R; Boas, David A; Wald, Lawrence L

    2016-05-13

    The influence of cardiac activity on the viscoelastic properties of intracranial tissue is one of the mechanisms through which brain-heart interactions take place, and is implicated in cerebrovascular disease. Cerebrovascular disease risk is not fully explained by current risk factors, including arterial compliance. Cerebrovascular compliance is currently estimated indirectly through Doppler sonography and magnetic resonance imaging (MRI) measures of blood velocity changes. In order to meet the need for novel cerebrovascular disease risk factors, we aimed to design and validate an MRI indicator of cerebrovascular compliance based on direct endogenous measures of blood volume changes. We implemented a fast non-gated two-dimensional MRI pulse sequence based on echo-planar imaging (EPI) with ultra-short repetition time (approx. 30-50 ms), which stepped through slices every approximately 20 s. We constrained the solution of the Bloch equations for spins moving faster than a critical speed to produce an endogenous contrast primarily dependent on spin volume changes, and an approximately sixfold signal gain compared with Ernst angle acquisitions achieved by the use of a 90° flip angle. Using cardiac and respiratory peaks detected on physiological recordings, average cardiac and respiratory MRI pulse waveforms in several brain compartments were obtained at 7 Tesla, and used to derive a compliance indicator, the pulsatility volume index (pVI). The pVI, evaluated in larger cerebral arteries, displayed significant variation within and across vessels. Multi-echo EPI showed the presence of significant pulsatility effects in both S0 and [Formula: see text] signals, compatible with blood volume changes. Lastly, the pVI dynamically varied during breath-holding compared with normal breathing, as expected for a compliance indicator. In summary, we characterized and performed an initial validation of a novel MRI indicator of cerebrovascular compliance, which might prove useful

  19. EFFECTS OF VASCULAR ZERO-STRESS STATE ON PULSATILE BLOOD FLOW

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In this paper, blood flow in artery was treated as the flow under equilibrium state (the steady flow under mean pressure) combined with the periodically small pulsatile flow. Based on vascular zero-stress state[1], the pulsatile strains according to the radial and axial displacements of blood vessel were obtained. With the use of Hooke’s law, the pulsatile strains and the corresponding Cauchy stresses were connected, so the corresponding wall motion equations could be established here. By solving the linearized Navier-Stokes equations, the analytic expressions of the blood flow velocities and the vascular displacements could be obtained, and the influence of the circumferential and axial stretch ratio on pulsatile blood flow and vascular motion was discussed in details.

  20. Hydrodynamic characteristics of mechanical heart valve prostheses in steady and pulsatile flow

    Czech Academy of Sciences Publication Activity Database

    Klimeš, František; Kořenář, Josef

    2002-01-01

    Roč. 9, č. 4 (2002), s. 249-258. ISSN 1210-2717 Institutional research plan: CEZ:AV0Z2060917 Keywords : mechanical heart valve prostheses * flow visualization- steady and pulsatile flow Subject RIV: BO - Biophysics

  1. Field-Induced Self-Assembled Ferrofluid Aggregation in Pulsatile Flow

    OpenAIRE

    Ganguly, . R.; Zellmer, B.; Puri, Ishwar K.

    2005-01-01

    Ferrofluid aggregation and dispersion occurs at several length scales in pulsatile flow applications, e. g., in ferrofluidic pumps, valves, and biomedical applications such as magnetic drug targeting. Because of a yet limited understanding, ferrohydrodynamic investigations involving laboratory-scale studies in idealized geometries are of considerable use. We have injected a ferrofluid into a pulsatile host flow and produced field-induced dissolution (aggregation) using external magnets. A com...

  2. Design and In Vitro Evaluation of Compression-coated Pulsatile Release Tablets of Losartan Potassium

    OpenAIRE

    Bajpai, M.; Singh, D. C. P.; Bhattacharya, A.; Singh, A.

    2012-01-01

    In majority of individuals blood pressure rises in the early morning hours, which lead to serious cardiovascular complications. Formulation of pulsatile system makes it possible to deliver drug at definite period of time when symptoms of the disease condition are most critical. The purpose of the present work was to develop pulsatile release tablet of losartan potassium for chronotherapy in hypertension. The prepared system consisted of a core tablet coated with versatile and safe hydrophilic...

  3. Optimization Studies on Compression Coated Floating-Pulsatile Drug Delivery of Bisoprolol

    OpenAIRE

    Swati C. Jagdale; Bari, Nilesh A.; Kuchekar, Bhanudas S.; Chabukswar, Aniruddha R.

    2013-01-01

    The purpose of the present work was to design and optimize compression coated floating pulsatile drug delivery systems of bisoprolol. Floating pulsatile concept was applied to increase the gastric residence of the dosage form having lag phase followed by a burst release. The prepared system consisted of two parts: a core tablet containing the active ingredient and an erodible outer shell with gas generating agent. The rapid release core tablet (RRCT) was prepared by using superdisintegrants w...

  4. Three-dimensional shape construction of pulsatile tissue from ultrasonic movies for assistance of clinical diagnosis

    Science.gov (United States)

    Fukuzawa, Masayuki; Kawaguchi, Hikari; Yamada, Masayoshi; Nakamori, Nobuyuki; Kitsunezuka, Yoshiki

    2010-02-01

    Three-dimensional shape of pulsatile tissue due to blood flow, which is one of key diagnostic features in ischemia, has been constructed from 2D ultrasonic movies for assisting clinical diagnosis. The 2D ultrasonic movies (640x480pixels/frame, 8bits/pixel, 33ms/frame) were taken with a conventional ultrasonic apparatus and an ultrasonic probe, while measuring the probe orientations with a compact tilt-sensor. The 2D images of pulsatile strength were obtained from each 2D ultrasonic movie by evaluating a heartbeat-frequency component calculated by Fourier transform of a series of pixel values sampled at each pixel. The 2D pulsatile images were projected into a 3D domain to obtain a 3D grid of pulsatile strength according to the probe orientations. The 3D shape of pulsatile tissue was constructed by determining the iso-surfaces of appropriate strength in the 3D grid. The shapes of pulsatile tissue examined in neonatal crania clearly represented the 3D structures of several arteries such as middle cerebral artery, which is useful for diagnosis of ischemic diseases. Since our technique is based on feature extraction in tissue dynamics, it is also useful for homogeneous tissue, for which conventional 3D ultrasonogram is unsuitable due to unclear tissue boundary.

  5. Bioidentical Hormones and Menopause

    Science.gov (United States)

    ... Balance › Bioidentical Hormones and Menopause Fact Sheet Bioidentical Hormones and Menopause January, 2012 Download PDFs English Espanol ... take HT for symptom relief.) What are bioidentical hormones? Bioidentical hormones are identical to the hormones that ...

  6. 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

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

    International Nuclear Information System (INIS)

    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

  8. Kisspeptin regulates gonadotropin-releasing hormone secretion in gonadotropin-releasing hormone/enhanced green fluorescent protein transgenic rats

    Institute of Scientific and Technical Information of China (English)

    Haogang Xue; Chunying Yang; Xiaodong Ge; Weiqi Sun; Chun Li; Mingyu Qi

    2013-01-01

    Kisspeptin is essential for activation of the hypothalamo-pituitary-gonadal axis. In this study, we established gonadotropin-releasing hormone/enhanced green fluorescent protein transgenic rats. Rats were injected with 1, 10, or 100 pM kisspeptin-10, a peptide derived from full-length kisspeptin, into the arcuate nucleus and medial preoptic area, and with the kisspeptin antagonist peptide 234 into the lateral cerebral ventricle. The results of immunohistochemical staining revealed that pulsatile luteinizing hormone secretion was suppressed after injection of antagonist peptide 234 into the lateral cerebral ventricle, and a significant increase in luteinizing hormone level was observed after kisspeptin-10 injection into the arcuate nucleus and medial preoptic area. The results of an enzyme-linked immunosorbent assay showed that luteinizing hormone levels during the first hour of kisspeptin-10 infusion into the arcuate nucleus were significantly greater in the 100 pM kisspeptin-10 group than in the 10 pM kisspeptin-10 group. These findings indicate that kisspeptin directly promotes gonadotropin-releasing hormone secretion and luteinizing hormone release in gonadotropin-releasing hormone/enhanced green fluorescent protein transgenic rats. The arcuate nucleus is a key component of the kisspeptin-G protein-coupled receptor 54 signaling pathway underlying regulating luteinizing hormone pulse secretion.

  9. 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...

  10. A pulsatile pump for cardiopulmonary bypass and its clinical use.

    Science.gov (United States)

    Sasaki, Y; Kawai, T; Nishiyama, K; Murayama, Y; Toda, S; Wada, T; Kitaura, K; Sato, S; Kadowaki, M; Kanki, Y

    1988-09-01

    A pulsatile pump driven by a coil spring, which was designed and constructed by us, is described in this report. It consists of two main parts, a disposable blood chamber and a driving section. The blood chamber has two leaflet valves and a piston, which is covered with two bellofram rolling diaphragms and moves into the housing to draw in and eject the blood. The driving section consists of three cams, an electric motor and a coil spring. The ejection force is wholly produced by the compressed coil spring and is transmitted to the piston in the blood chamber by a rod. This pump allows the ejection pressure, the beat rates, and the stroke volume all to be changed independently. The performance of the pump was tested by using a circulation model where the beat rate was adjusted from 30 to 250 bpm. The output subsequently increased from 0.8 l/min to 5.7 l/min and the stroke volume, from 20.4 ml to 36.7 ml. This new pump has been used for clinical cardiopulmonary bypasses in 24 patients of open heart surgery and the pressure traces during perfusion resembled those of the patients' own hearts. PMID:3230723

  11. CT evaluation of sigmoid plate dehiscence causing pulsatile tinnitus

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  12. Cora valveless pulsatile rotary pump: new design and control.

    Science.gov (United States)

    Monties, J R; Trinkl, J; Mesana, T; Havlik, P J; Demunck, J L

    1996-01-01

    For decades, research for developing a totally implantable artificial ventricle has been carried on. For 4 to 5 years, two devices have been investigated clinically. For many years, we have studied a rotary (but not centrifugal) pump that furnishes pulsatile flow without a valve and does not need external venting or a compliance chamber. It is a hypocycloidal pump based on the principle of the Maillard-Wankel rotary compressor. Currently made of titanium, it is activated by an electrical brushless direct-current motor. The motor-pump unit is totally sealed and implantable, without noise or vibration. This pump was implanted as a left ventricular assist device in calves. The midterm experiments showed good hemodynamic function. The hemolysis was low, but serious problems were encountered: blood components collecting on the gear mechanism inside the rotor jammed the pump. We therefore redesigned the pump to seal the gear mechanism. We used a double system to seal the open end of the rotor cavity with components polished to superfine optical quality. In addition, we developed a control system based on the study of the predicted shape of the motor current. The new design is now underway. We hope to start chronic experiments again in a few months. If the problem of sealing the bearing could be solved, the Cora ventricle could be used as permanent totally implantable left ventricular assist device. PMID:8561627

  13. Unexpected responses of the hypothalamic gonadotropin-releasing hormone "pulse generator" to physiological estradiol inputs in the absence of the ovary.

    OpenAIRE

    Kesner, J S; Wilson, R. C.; Kaufman, J.M.; Hotchkiss, J.; Chen, Y.; Yamamoto, H; Pardo, R R; Knobil, E

    1987-01-01

    In the rhesus monkey (Macaca mulatta), the frequency of pulsatile gonadotropic hormone release is relatively constant in the face of widely varying levels of estradiol (E2) in the peripheral circulation--e.g., in the course of the follicular phase of the menstrual cycle and after ovariectomy. This suggests that modulation of the hypothalamic gonadotropin-releasing hormone (GnRH) "pulse generator" by this steroid is not of major physiological importance. Herein is described the unexpected inhi...

  14. FORMULATION AND EVALUATION OF PULSATILE DRUG DELIVERY SYSTEM CONTAINING INDOMETHACIN USING NATURAL POLYMERS

    Directory of Open Access Journals (Sweden)

    Kamat Akshay Ramesh

    2013-02-01

    Full Text Available Aim of the present work was to formulate and evaluate an oral pulsatile drug delivery system using natural superdisintegrants and natural polymers to achieve time release of Indomethacin, based on chronopharmaceutical approach for the treatment of rheumatoid arthritis. Pulsatile delivery system is capable of delivering drug when and where it required most. By administering the system at bedtime, but releasing drug as a burst after the lag time (during peak morning hours thereby delivering the drug when and where it is required the most with decreased side effects, dose size and prolonged action. The press-coated pulsatile release tablet contains Indomethacin in the inner rapid release core tablet formulated by direct compression method using plantago ovata mucilage and modified agar as superdisintegrants and the external coat formulated using natural polymers such as dammar gum, chitosan, xanthan gum and gaur gum by both direct and wet granulation method. The prepared press-coated pulsatile tablets were evaluated for various pre-compressional and post-compressional parameters. In-vitro release profiles of pulsatile device during 10 h studies were found to have very good sustaining efficacy. Formulation code A1, A8, B2 and B7 were selected as the best formulations with formulation B2 containing xanthan gum and dammar gum in the ratio 2:1 having maximum lag time of 7 h 15 min.

  15. Experimental study on average frictional pressure drop of gas-liquid two-phase pulsatile flow

    International Nuclear Information System (INIS)

    The gas-liquid two-phase pulsatile flow was studied in a rectangular channel with 40 mm × 3 mm cross section under different periods, flow rate amplitudes and its mean values (mean Re1<10000, mean Reg<800). There was difference between the single phase pulsatile flow and the gas-liquid two-phase pulsatile flow, and pulsation period and amplitude were not sensitive for the average frictional pressure drop. There was no significant difference on the values and distribution between the calculation deviations in pulsatile flow and the calculation deviations in steady flow by using different empirical formulas. Almost all of the relative deviations were less than 20%, and the relative deviations of Mishima-Hibiki method and Lee-Lee method were less than 10%. The results show that the empirical formulas for the two-phase steady flow frictional pressure drop are also suitable for the calculation of the average value of two-phase pulsatile flow. (authors)

  16. 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

  17. Hormone impostors

    Energy Technology Data Exchange (ETDEWEB)

    Colborn, T.; Dumanoski, D.; Myers, J.P.

    1997-01-01

    This article discusses the accumulating evidence that some synthetic chemicals disrupt hormones in one way or another. Some mimic estrogen and others interfere with other parts of the body`s control or endocrine system such as testosterone and thyroid metabolism. Included are PCBs, dioxins, furans, atrazine, DDT. Several short sidebars highlight areas where there are or have been particular problems.

  18. Analytical and experimental characterization of a miniature calorimetric sensor in pulsatile flow

    CERN Document Server

    Gelderblom, H; Haartsen, J R; Rutten, M C M; van de Ven, A A F; van de Vosse, F N; 10.1017/S0022112010004234

    2011-01-01

    The behaviour of a miniature calorimetric sensor, which is under consideration for catheter-based coronary artery flow assessment, is investigated in both steady and pulsatile tube flow. The sensor is composed of a heating element operated at constant power, and two thermopiles that measure flow-induced temperature differences over the sensor surface. An analytical sensor model is developed, which includes axial heat conduction in the fluid and a simple representation of the solid wall, assuming a quasi-steady sensor response to the pulsatile flow. To reduce the mathematical problem, described by a two-dimensional advection-diffusion equation, a spectral method is applied. A Fourier transform is then used to solve the resulting set of ordinary differential equations and an analytical expression for the fluid temperature is found. To validate the analytical model, experiments with the sensor mounted in a tube have been performed in steady and pulsatile water flow with various amplitudes and Strouhal numbers. E...

  19. Endocrine Glands & Their Hormones

    Science.gov (United States)

    ... Characteristics of Hormones Endocrine Glands & Their Hormones Pituitary & Pineal Glands Thyroid & Parathyroid Glands Adrenal Gland Pancreas Gonads Other ... hormone secretion. « Previous (Characteristics of Hormones) Next (Pituitary & Pineal Glands) » Contact Us | Privacy Policy | Accessibility | FOIA | File Formats ...

  20. Evaluation of a physiologic pulsatile pump system for neonate-infant cardiopulmonary bypass support.

    Science.gov (United States)

    Undar, A; Masai, T; Inman, R; Beyer, E A; Mueller, M A; McGarry, M C; Frazier, O H; Fraser, C D

    1999-01-01

    An alternate physiologic pulsatile pump (PPP) system was designed and evaluated to produce sufficient pulsatility during neonate-infant open heart surgery. This hydraulically driven pump system has a unique "dual" pumping chamber mechanism. The first chamber is placed between the venous reservoir and oxygenator and the second chamber between the oxygenator and patient. Each chamber has two unidirectional tricuspid valves. Stroke volume (0.2-10 ml), upstroke rise time (10-350 msec), and pump rate (2-250 beats per minute [bpm]) can be adjusted independently to produce adequate pulsatility. This system has been tested in 3-kg piglets (n = 6), with a pump flow of 150 ml/kg/min, a pump rate of 150 bpm, and a pump ejection time of 110 msec. After initiation of cardiopulmonary bypass (CPB), all animals were subjected to 25 minutes of hypothermia to reduce the rectal temperatures to 18 degrees C, 60 minutes of deep hypothermic circulatory arrest (DHCA), then 10 minutes of cold perfusion with a full pump flow, and 40 minutes of rewarming. During CPB, mean arterial pressures were kept at less than 50 mm Hg. Mean extracorporeal circuit pressure (ECCP), the pressure drop of a 10 French aortic cannula, and the pulse pressure were 67+/-9, 21+/-6, and 16+/-2 mm Hg, respectively. All values are represented as mean+/-SD. No regurgitation or abnormal hemolysis has been detected during these experiments. The oxygenator had no damping effect on the quality of the pulsatility because of the dual chamber pumping mechanism. The ECCP was also significantly lower than any other known pulsatile system. We conclude that this system, with a 10 French aortic cannula and arterial filter, produces adequate pulsatility in 3 kg piglets. PMID:9952008

  1. 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.

  2. Formulation and process optimization of multiparticulate pulsatile system delivered by osmotic pressure-activated rupturable membrane.

    Science.gov (United States)

    Hung, Sheng-Feng; Hsieh, Chien-Ming; Chen, Ying-Chen; Lin, Cheng-Mao; Ho, Hsiu-O; Sheu, Ming-Thau

    2015-03-01

    In this study, a multiparticulate pulsatile drug delivery system activated by a rupturable controlled-release membrane (Eudragit(®) RS) via osmotic pressure (with NaCl as the osmogent) was developed and characterized for omeprazole, omeprazole sodium, and propranolol HCl which have different water solubilities. Multiparticulates in pellet form for incorporation with or without the osmogent were manufactured by three methods and then used to coat a polymeric membrane. Results demonstrated that drug/osmogent-containing pellets manufactured by the extrusion/spheronization method with incorporation of the osmogent were optimal. The lag time (tL) to initiate pulsatile release is regulated by tL=l(2)/(6×D), which is dependent on the coating levels (l(2)) and plasticizer content (D). The pulsatile release pattern was found to be dependent on the osmotic pressure (osmogent), drug solubility, and mechanical properties of the polymeric membrane (elasticity and toughness). Omeprazole with lower water solubility could not generate sufficient osmotic pressure to create a crack in the membrane to activate pulsatile release, whereas the two other model drugs with higher solubilities could. But adsorption of omeprazole sodium on Eudragit(®) RS via charge-charge interactions led the its incomplete release. Finally, with 4% osmogent of NaCl added, a lag time in a range from 0 to 12h proportionally regulated by varying both the membrane thickness and plasticizer level initiated the complete pulsatile release of propranolol HCl. In conclusion, a multiparticulate pulsatile drug delivery system activated by a rupturable controlled-release membrane via osmotic pressure was successfully developed, and clinical applications of chronotherapy with drugs like propranolol HCl are expected. PMID:25575473

  3. 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.

  4. Hormonal changes in humans during spaceflight.

    Science.gov (United States)

    Strollo, F

    1999-01-01

    Readers of this review may feel that there is much more that we do not know about space endocrinology than what we know. Several reasons for this state of affairs have been given: 1. the complexity of the field of endocrinology with its still increasing number of known hormones, releasing factors and precursors, and of the interactions between them through various feedback mechanisms 2. the difficulty in separating the microgravity effects from the effects of stress from launch, isolation and confinement during flight, reentry, and postflight re-adaptation 3. the experimental limitations during flight, such as limited number of subjects, limited number of samples, impossibility of collecting triple samples for pulsatile hormones like growth hormone 4. the disturbing effects of countermeasures used by astronauts 5. the inadequacy of postflight samples for conclusions about inflight values 6. limitations of conclusions from animal experiments and space simulation studies The endocrinology field is divided in to nine systems or axes, which are successively reviewed: 1. Rapid bone demineralization in the early phase of spaceflight that, when unopposed, leads to catastrophic effects after three months but that slows down later. The endocrine mechanism, apart from the effect of exercise as a countermeasure, is not yet understood. 2. The hypothalamic-pituitary-adrenal axis is involved in stress reactions, which complicate our understanding and makes postflight analysis dubious. 3. In the hypothalamic-pituitary-gonadal axis, pulsatility poses a problem for obtaining representative values (e.g., for luteinizing hormone). Reproduction of rats in space is possible, but much more needs to be known about this aspect, particularly in women, before the advent of space colonies, but also in males because some evidence for reversible testicular dysfunction in space has been found. 4. The hypothalamic-pituitary-somato-mammotrophic axis involves prolactin and growth hormone. The

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

    International Nuclear Information System (INIS)

    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

  6. 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)], e-mail: gongs@ccmu.edu.cn

    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.

  7. A quantitative study of CSF pulsatile flow in normal pressure hydrocephalus

    International Nuclear Information System (INIS)

    In the previous report, we described the visualization and quantitative analysis of a normal CSF pulsatile flow using cine MR phase imaging. In the present study, CSF flow velocities were measured in patients with normal pressure hydrocephalus (NPH) before and after a shunting procedure. All of the healthy subjects showed a similar flow pattern in the time-velocity flow profiles (TVFP). However, patients with NPH showed a variable pattern of TVFP and could be divided into the following four types: Type 0: the CSF flow pattern was similar to that of the healthy subjects. Type I: the caudal peak flow was delayed more than 190 msec on TVFP. Type II: the caudal peak flow was not apparent, but the CSF flow through the aqueduct was remarkable on phase images. Type III: the amplitude of TVFP was very small, and no CSF flow through the aqueduct was identified. The patients with Type III TVFP showed significantly lower NPH scores. The lumbar CSF pressures tended to be high in the patients with Type III TVFP, but nevertheless failed to reach a statistically significant level. The amplitude of TVFP increased in the patients who improved clinically after the shunting procedure. Some of the Type III patients changed into Type II, I, and 0; also, one of the Type II patients changed into a Type I patients after the shunting procedure. We conclude that cine MR phase imaging is useful for analyzing the CSF flow of the patients with NPH before and after the shunting procedure as well as for evaluating shunt patency. (author)

  8. Development of a new introduction technique for the pulsatile catheter pump

    NARCIS (Netherlands)

    Mihaylov, D; Kik, C; Elstrodt, J; Verkerke, GJ; Blanksma, PK; Rakhorst, G

    1997-01-01

    The pulsatile catheter (PUCA) pump is an intraventricular blood pump that can be introduced into the left ventricular cavity through a superficial artery (trans arterially) or directly through the thoracic aorta during open chest conditions. When positioned, the pump aspirates blood from the left ve

  9. Evaluation of the optimal driving mode during left ventricular assist with pulsatile catheter pump in calves

    NARCIS (Netherlands)

    Mihaylov, D; Verkerke, GJ; Blanksma, PK; Elstrodt, J; de Jong, ED; Rakhorst, G

    1999-01-01

    The pulsatile catheter (PUCA) pump, a left ventricular assist device, was tested during acute experiments in calves using asynchronous and EGG-synchronous assist modes. The aim of the study is to compare ECG-synchronous and asynchronous assist and to find the optimal driving mode for the PUCA pump w

  10. IN-VITRO EVALUATION OF THE INFLUENCE OF PULSATILE INTRAVENTRICULAR PUMPING ON VENTRICULAR PRESSURE PATTERNS

    NARCIS (Netherlands)

    RAKHORST, G; VERKERKE, GJ; HENSENS, AG; DEMUINCK, ED; BLANKSMA, PK; PILLON, M; JUFER, M

    1994-01-01

    The Pulsatile catheter (PUCA) pump consists of a single port membrane pump connected to an indwelling valved catheter. This so-called transarterial blood pump was originally designed to be introduced through a superficial artery into the left ventricular cavity to pump blood from the left ventricle

  11. Flap raising on pulsatile perfused cadaveric tissue: a novel method for surgical teaching and exercise.

    Science.gov (United States)

    Wolff, Klaus-Dietrich; Fichter, Andreas; Braun, Christian; Bauer, Florian; Humbs, Martin

    2014-10-01

    Exercising flap raising procedures on cadavers is considered a prerequisite to prepare for clinical practise. To improve teaching and create conditions as realistic as possible, a perfusion device was developed providing pulsatile flow through the vessels of different donor sites. A plastic bag filled with red stained tab water was placed into a pump, which was driven by an electric motor. The bag was set under rhythmic compression with variable frequency and pressure. The pedicles of the radial forearm, anterolateral thigh, rectus abdominis, fibular and iliac crest flap were cannulated at the origin from their source arteries. Flap raising was performed under pulsatile perfusion in 15 fresh bodies and subsequently in 6 Thiel-embalmed cadavers during a flap raising course. We regularly observed staining of the skin and skin bleeding in fresh bodies and less reliable in embalmed cadavers. All flap pedicles showed pulsatile movements, and the radial pulse became palpable. Most perforators of the anterolateral thigh and osteocutaneous fibular flap could be identified by their pulse. Bleeding from bony tissue and venous return was seldom observed. We conclude that pulsatile perfusion of cadaveric tissue creates more realistic conditions for flap raising and improves teaching for beginners and advanced surgeons. PMID:24938642

  12. Three-dimensional flow separation over a surface-mounted hemisphere in pulsatile flow

    Science.gov (United States)

    Carr, Ian A.; Plesniak, Michael W.

    2016-01-01

    Flow separation over a surface-mounted obstacle is prevalent in numerous applications. Previous studies of 3D separation around protuberances have been limited to steady flow. In biological and geophysical flows, pulsatile conditions are frequently encountered, yet this situation has not been extensively studied. Primarily motivated by our previous studies of the flow patterns observed in various human vocal fold pathologies such as polyps, our research aimed to fill this gap in the knowledge concerning unsteady 3D flow separation. This is achieved by characterizing velocity fields surrounding the obstacle, focused primarily on the vortical flow structures and dynamics that occur around a hemispheroid in pulsatile flow. As part of this study, two-dimensional, instantaneous and phase-averaged particle image velocimetry data in both steady and pulsatile flows are presented and compared. Coherent vortical flow structures have been identified by their swirling strength. This analysis revealed flow structures with dynamics dependent on the pulsatile forcing function. A mechanism to explain the formation and observed dynamics of these flow structures based on the self-induced velocity of vortex rings interacting with the unsteady flow is proposed.

  13. Pulsatile lavage for pressure ulcer management in spinal cord injury: a retrospective clinical safety review.

    Science.gov (United States)

    Bogie, Kath M; Ho, Chester H

    2013-03-01

    Pressure ulcers are major complications of reduced mobility and/or sensation. Pulsatile lavage therapy delivers localized hydrotherapy directly to the wound utilizing a pulsatile pressurized stream of normal saline. The purpose of this study was to evaluate the clinical safety of pulsatile lavage therapy, provided daily at the bedside, in routine management of Stage III and Stage IV pressure ulcers. Charts from 28 male patients with Stage III and Stage IV pressure ulcers and spinal cord injury (SCI) or spinal cord disorders (SCD) were retrospectively reviewed for documentation of adverse events/safety concerns. Mean therapy duration was 46 days (SD 37 days, range 6-152 days). Treatment was interrupted for 6 days in one patient due to minor wound bleeding. No other adverse events, including backsplash injuries, were documented. The results of this chart review suggest pulsatile lavage therapy can be administered at the patient's bedside without adverse events if appropriate protocols are followed. Additional research to confirm the efficacy and effectiveness of this treatment modality in a broader subject population is warranted. PMID:23475450

  14. Development and optimization of press coated floating pulsatile drug delivery of sumatriptan succinate.

    Science.gov (United States)

    Jagdale, Swati C; Pawar, Chandrakala R

    2014-01-01

    Floating pulsatile is combined approach designed according to circadian rhythm to deliver the drug at right time, in right quantity and at right site as per pathophysiological need of disease with prolong gastric residence and lag phase followed by burst release. As the migraine follows circadian rhythm in which headache is more painful at the awakening time, the dosage form should be given during night time to release drug when pain get worsen. Present work deals with formulation and optimization of floating pulsatile tablet of sumatriptan succinate. Core tablet containing crospovidone as superdisintegrant (10%) showed burst release. Lag time was maintained using swellable polymer as polyoxN12K and xanthum gum. 3(2) experimental design was carried out. Developed formulations were evaluated for physical characteristics, in vitro and in vivo study. Optimized batch F2 with concentration of polyox N12K (73.43%) and xanthum gum (26.56%) of total polymer weight showed floating lag time 15±2 sec, drug content 99.58±0.2 %, hardness 6±0.2 Kg/cm(2) and drug release 99.54±2% with pulsatile manner followed lag period of 7±0.1h. In vivo x-ray study confirms prolong gastric residence of system. Programmable pulsatile release has been achieved by formulation F2 which meet demand of chronotherapeutic objective of migraine. PMID:24893996

  15. FORMULATION AND OPTIMIZATION OF FLOATING PULSATILE ACECLOFENAC MICROSPHERES USING RESPONSE SURFACE METHODOLOGY

    Directory of Open Access Journals (Sweden)

    Shaji Jessy

    2012-01-01

    Full Text Available The purpose of present work is to develop aceclofenac microspheres for floating pulsatile release intended for chronopharmacotheraphy. Floating pulsatile concept was applied to increase the gastric residence of the dosage form having lag phase followed by a burst release. The floating pulsatile microspheres were prepared by emulsion solvent diffusion technique. A 32 factorial design was employed to study the effect of independent variables, drug to polymer ratio and stirring speed, on dependent variables, particle size and drug entrapment efficiency. The best batch exhibited a high entrapment efficiency of 90.1% and mean particle size 118.66 μm. Polymers used for the preparation were Eudragit L100 and Eudragit S100 which gets solubilized at pH above 6 and 7 respectively. The floating microsphere provides two phase release pattern with initial lag time during floating in acidic medium followed by rapid release in phosphate buffer. This approach suggested the use of floating pulsatile microsphere as promising drug delivery for site and time specific release of aceclofenac for chronotheraphy of rheumatoid arthritis.

  16. The effect of pulsatile cardiopulmonary bypass on lung function in elderly patients

    NARCIS (Netherlands)

    Engels, Gerwin E.; Dodonov, Mikhail; Rakhorst, Gerhard; van Oeveren, Willem; Milano, Aldo D.; Gu, Y. John; Faggian, Giuseppe

    2014-01-01

    Purpose: Cardiopulmonary bypass is still a major cause of lung injury and delay in pulmonary recovery after cardiac surgery. Although it has been shown that pulsatile flow induced by intra-aortic balloon pumping is beneficial for preserving lung function, it is not clear if the same beneficial effec

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

    NARCIS (Netherlands)

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

    2010-01-01

    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 Netherland

  18. Oxygen analyzer

    Science.gov (United States)

    Benner, William H.

    1986-01-01

    An oxygen analyzer which identifies and classifies microgram quantities of oxygen in ambient particulate matter and for quantitating organic oxygen in solvent extracts of ambient particulate matter. A sample is pyrolyzed in oxygen-free nitrogen gas (N.sub.2), and the resulting oxygen quantitatively converted to carbon monoxide (CO) by contact with hot granular carbon (C). Two analysis modes are made possible: (1) rapid determination of total pyrolyzable oxygen obtained by decomposing the sample at 1135.degree. C., or (2) temperature-programmed oxygen thermal analysis obtained by heating the sample from room temperature to 1135.degree. C. as a function of time. The analyzer basically comprises a pyrolysis tube containing a bed of granular carbon under N.sub.2, ovens used to heat the carbon and/or decompose the sample, and a non-dispersive infrared CO detector coupled to a mini-computer to quantitate oxygen in the decomposition products and control oven heating.

  19. Thymic hormones

    Energy Technology Data Exchange (ETDEWEB)

    Davies, A.J.S.

    1975-02-28

    RResults of experiments by various investigators attempting to demonstrate the existence of thymic hormones are reported. In most cases irradiated, thymectomized mice injected with bone marrow cells were used; some experiments were carried out on various extracts of thymuses. Results of most experiments were negative. In one experiment using mice with thymus transplants, sera were evaluated for their capacity to restore azathioprine sensitivity in relation to the rosette forming capacity to spleen cells of thymectomized mice in vitro. In all instances the thymus-grafted mice had a higher titer of serum factor than did normal mice. (HLW)

  20. Formulation and Evaluation of Chronomodulated Pulsatile Drug Delivery System of Salbutamol Sulphate

    Directory of Open Access Journals (Sweden)

    Anusha V

    2015-12-01

    Full Text Available Chronotherapy denotes the therapy in which the release of the drug in the body is allowed to match with the circadian rhythm of the disease, such that the required action of the drug is shown with minimal side effects. The main interesting fact of chronotherapy is its ability to deliver the drug in required concentrations during the time of its greatest need such that synchronizing circadian rhythm of diseases or symptoms. Pulsatile drug delivery system for Salbutamol sulphate was formulated initially as core tablets followed by formulation of pulsatile tablets using press-coated technology. Core tablets were formulated using various concentrations of superdisintegrant (Sodium starch glycolate, cross povidone and diluents (MCC & Dicalcium phosphate. The core tablets were then compressed into pulsatile tablets using combinations of HPMC K 100M and Eudragit L 100, Eudragit S 100 in various concentrations. Core tablets were evaluated and based on the dissolution studies trial T3was optimized as it shows lower disintegration time and faster drug release. Then the pulsatile tablets were evaluated for various tests and drug release studies were conducted for 2 hours in 0.1N HCl followed by pH 6.8 buffer and the trial S6 was optimized which showed satisfactory greater lag time of about 6 hours with satisfactory drug release which contains a combination of HPMC K15M (20mg, Eudragit L 100 (50mg, Eudragit S100 (60mg. Pulsatile tablets were formulated utilizing press coated technology and the combination of polymers provided required lag time with satisfactory dissolution profile.

  1. DynPeak : An algorithm for pulse detection and frequency analysis in hormonal time series

    CERN Document Server

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

    2011-01-01

    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 feedb...

  2. Thyroid Hormone Treatment

    Science.gov (United States)

    ... Giving Workplace Giving Other Ways to Donate Thyroid Hormone Treatment Thyroid hormone is used in two situations: ... prevent recurrence or progression of their cancer. THYROID HORMONE REPLACEMENT THERAPY Many people have a thyroid gland ...

  3. Hormone Replacement Therapy

    Science.gov (United States)

    ... before and during menopause, the levels of female hormones can go up and down. This can cause ... hot flashes and vaginal dryness. Some women take hormone replacement therapy (HRT), also called menopausal hormone therapy, ...

  4. Growth hormone test

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003706.htm Growth hormone test To use the sharing features on this page, please enable JavaScript. The growth hormone test measures the amount of growth hormone in ...

  5. The Effect of Pulsatile Versus Nonpulsatile Blood Flow on Viscoelasticity and Red Blood Cell Aggregation in Extracorporeal Circulation

    OpenAIRE

    Ahn, Chi Bum; Kang, Yang Jun; Kim, Myoung Gon; Yang, Sung; Lim, Choon Hak; Son, Ho Sung; Kim, Ji Sung; Lee, So Young; Son, Kuk Hui; Sun, Kyung

    2016-01-01

    Background Extracorporeal circulation (ECC) can induce alterations in blood viscoelasticity and cause red blood cell (RBC) aggregation. In this study, the authors evaluated the effects of pump flow pulsatility on blood viscoelasticity and RBC aggregation. Methods Mongrel dogs were randomly assigned to two groups: a nonpulsatile pump group (n=6) or a pulsatile pump group (n=6). After ECC was started at a pump flow rate of 80 mL/kg/min, cardiac fibrillation was induced. Blood sampling was perfo...

  6. A Case of Pulsatile Tinnitus from the Atherosclerosis and Atheroma in Superior Labial Artery and Facial Artery

    OpenAIRE

    Kim, Jung Min; Kim, Choon Dong; Kim, Seung Woo

    2012-01-01

    Tinnitus is one of the most common symptoms in an audiologic field. It can be classified as either as subjective or objective; former referring to the sensation heard by both patient and examiner. Pulsatile tinnitus is perceived as sounds that vary in frequency, intensity and duration. The cause of pulsatile tinnitus include high jugular bulb, benign intracranial hypertension, glomus tumors, carotid artery stenosis, vascular lesions of the temporal bone, arteriovenous malformation, aneurysms,...

  7. A new imaging technique on strength and phase of pulsatile tissue-motion in brightness-mode ultrasonogram

    Science.gov (United States)

    Fukuzawa, Masayuki; Yamada, Masayoshi; Nakamori, Nobuyuki; Kitsunezuka, Yoshiki

    2007-03-01

    A new imaging technique has been developed for observing both strength and phase of pulsatile tissue-motion in a movie of brightness-mode ultrasonogram. The pulsatile tissue-motion is determined by evaluating the heartbeat-frequency component in Fourier transform of a series of pixel value as a function of time at each pixel in a movie of ultrasonogram (640x480pixels/frame, 8bit/pixel, 33ms/frame) taken by a conventional ultrasonograph apparatus (ATL HDI5000). In order to visualize both the strength and the phase of the pulsatile tissue-motion, we propose a pulsatile-phase image that is obtained by superimposition of color gradation proportional to the motion phase on the original ultrasonogram only at which the motion strength exceeds a proper threshold. The pulsatile-phase image obtained from a cranial ultrasonogram of normal neonate clearly reveals that the motion region gives good agreement with the anatomical shape and position of the middle cerebral artery and the corpus callosum. The motion phase is fluctuated with the shape of arteries revealing local obstruction of blood flow. The pulsatile-phase images in the neonates with asphyxia at birth reveal decreases of the motion region and increases of the phase fluctuation due to the weakness and local disturbance of blood flow, which is useful for pediatric diagnosis.

  8. 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; Krueger, Katharina; Liu, Ying; Baumunk, Daniel; Zakrzewicz, Andreas; Tepel, Martin

    2012-01-01

    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...... shear stress, producing a constant laminar flow (generating a shear stress of 6 dyne/cm(2)), laminar pulsatile atheroprotective flow (with a mean shear stress of 20 dyne/cm(2)), or laminar atheroprone bidirectional flow (with a mean shear stress of 0 dyne/cm(2)) differentially induced TRPC6 and TRPV1 m......RNA as measured by quantitative real-time RT-PCR and normalized to GAPDH expression. Thereby, TRPC6 and TRPV1 mRNA expressions were significantly increased after 24 hours of exposure to an atheroprone flow profile compared with an atheroprotective flow profile. Furthermore, the expression of...

  9. Numerical reconstruction of pulsatile blood flow from 4D computer tomography angiography data

    CERN Document Server

    Lovas, Attila; Csobo, Elek; Szilágyi, Brigitta; Sótonyi, Péter

    2015-01-01

    We present a novel numerical algorithm developed to reconstuct pulsatile blood flow from ECG-gated CT angiography data. A block-based optimization method was constructed to solve the inverse problem corresponding to the Riccati-type ordinary differential equation that can be deduced from conservation principles and Hooke's law. Local flow rate for 5 patients was computed in 10cm long aorta segments that are located 1cm below the heart. The wave form of the local flow rate curves seems to be realistic. Our approach is suitable for estimating characteristics of pulsatile blood flow in aorta based on ECG gated CT scan thereby contributing to more accurate description of several cardiovascular lesions.

  10. Analysis of Pulsatile Flow of Blood in a Porous Channel under Effect of Magnetic Field

    Directory of Open Access Journals (Sweden)

    Mitali Sarma

    2011-11-01

    Full Text Available To study the effect of magnetic field on pulsatile flow of blood in a porous channel a numerical model has been developed. An approximate solution is presented to the problem of pulsatile flow of blood in a porous channel in presence of transverse magnetic field. The blood is assumed to be an incompressible non Newtonian fluid. To reduce the equation of motion to an ordinary differential equation, a dimensionless variable is used. Numerical results were obtained for different values of the magnetic parameter, frequency parameter and Reynolds number. It is observed that when the Hartmann number increases, the fluid velocity as well as magnitude as well as magnitude of mass flux decrease.

  11. Artificial Heart Rejects High Tech? Lessens Learnt from Non-pulsatile VAD with Straight Impeller Vanes

    OpenAIRE

    Qian, Kun-xi

    2007-01-01

    Despite the progresses in developing pulsatile impeller pump and impeller total heart, as well as in applying streamlined impeller vanes, the best results in application of artificial heart pumps have been achieved by nonpulsatile univentricular assist pump with straight impeller vanes until now. It seems all efforts and successes have been done in vain because artificial heart rejects Hi-Tech! This paper recalls some important achievements in R&D of artificial heart in past 25 years and shar...

  12. FORMULATION AND EVALUATION OF METOPROLOL SUCCINATE PULSATILE DRUG DELIVERY SYSTEM FOR CHRONO BIOLOGICAL DISORDER: ANTI HYPERTENSION

    OpenAIRE

    A. Anil Kumar et al

    2012-01-01

    The objective of the present study was to develop and evaluate an oral pulsatile drug delivery system to mimic the circadian rhythm of the disease by releasing the drug with a distinct predetermined log time of 5 hrs (+ 0.25 hrs). The basic design of the pulse in cap formulation of metoprolol provides time controlled release to treat the nocturnal symptoms of hypertension and angina pectoris. The pulsincap formulation of Metoprolol provides time controlled release to treat the nocturnal sympt...

  13. [Hormonal dysnatremia].

    Science.gov (United States)

    Karaca, P; Desailloud, R

    2013-10-01

    Because of antidiuretic hormone (ADH) disorder on production or function we can observe dysnatremia. In the absence of production by posterior pituitary, central diabetes insipidus (DI) occurs with hypernatremia. There are hereditary autosomal dominant, autosomal recessive or X- linked forms. When ADH is secreted but there is an alteration on his receptor AVPR2, it is a nephrogenic diabetes insipidus in acquired or hereditary form. We can make difference on AVP levels and/or on desmopressine response which is negative in nephrogenic forms. Hyponatremia occurs when there is an excess of ADH production: it is a euvolemic hypoosmolar hyponatremia. The most frequent etiology is SIADH (syndrome of inappropriate secretion of ADH), a diagnostic of exclusion which is made after eliminating corticotropin deficiency and hypothyroidism. In case of brain injury the differential diagnosis of cerebral salt wasting (CSW) syndrome has to be discussed, because its treatment is perfusion of isotonic saline whereas in SIADH, the treatment consists in administration of hypertonic saline if hyponatremia is acute and/or severe. If not, fluid restriction demeclocycline or vaptans (antagonists of V2 receptors) can be used in some European countries. Four types of SIADH exist; 10 % of cases represent not SIADH but SIAD (syndrome of inappropriate antidiuresis) due to a constitutive activation of vasopressin receptor that produces water excess. c 2013 Published by Elsevier Masson SAS. PMID:24356291

  14. FABRICATION OF PULSATILE DELIVERY MULTIPARTICULATE SYSTEM OF POORLY WATER SOLUBLE CARVEDILOL PHOSPHATE

    Directory of Open Access Journals (Sweden)

    Singh DK

    2012-09-01

    Full Text Available Pulsatile drug delivery system is required to satisfy the needs of chronotherapy. Among solids, multiparticulates have its own advantages. Pulsatile drug delivery system provides better therapy with many of the actives. Rupturable pulsatile drug delivery system consists of a drug core; swelling layer of a super disintegrant; and an insoluble, water-permeable polymeric coating. Upon water ingress, the swellable layer expands, resulting in the rupturing of outer membrane followed by drug release. The active pharmaceutical ingredient selected was Carvedilol Phosphate, deposited on sugar pellets as first layer. The second layer composed of swelling excipient, had crospovidone, L–substituted hydroxy propyl cellulose and sodium starch glycolate. Third and the outer most layer was based on ethyl cellulose. The release after lag time was fast and complete, when crospovidone was used as a swelling agent. In contrast, a sustained release was achieved after the lag time, when L–substituted hydroxy propyl cellulose and sodium starch glycolate were used as swelling agents. Fast release would be preferable in the present case. Optimal level of crospovidone to achieve a fast and complete release of Carvedilol phosphate was 33%. Outer membrane, formed using aqueous dispersion of ethyl cellulose was suitable enough to rupture sufficiently ensuring fast drug release, compared to stronger ethyl cellulose membrane formed using organic solution. It was possible to design multiparticulates of carvedilol phosphate having a suitable release profile.

  15. Alkaline phosphatase in osteoblasts is down-regulated by pulsatile fluid flow

    Science.gov (United States)

    Hillsley, M. V.; Frangos, J. A.

    1997-01-01

    It is our hypothesis that interstitial fluid flow plays a role in the bone remodeling response to mechanical loading. The fluid flow-induced expression of three proteins (collagen, osteopontin, and alkaline phosphatase) involved in bone remodeling was investigated. Rat calvarial osteoblasts subjected to pulsatile fluid flow at an average shear stress of 5 dyne/cm2 showed decreased alkaline phosphatase (AP) mRNA expression after only 1 hour of flow. After 3 hours of flow, AP mRNA levels had decreased to 30% of stationary control levels and remained at this level for an additional 5 hours of flow. Steady flow (4 dyne/cm2 fluid shear stress), in contrast, resulted in a delayed and less dramatic decrease in AP mRNA expression to 63% of control levels after 8 hours of flow. The reduced AP mRNA expression under pulsatile flow conditions was followed by reduced AP enzyme activity after 24 hours. No changes in collagen or osteopontin mRNA expression were detected over 8 hours of pulsatile flow. This is the first time fluid flow has been shown to affect gene expression in osteoblasts.

  16. Strategies for the Determination of Plant Hormones.

    Science.gov (United States)

    Davis, Gregory C.; And Others

    1985-01-01

    Describes methods for isolating, purifying, and analyzing plant hormones (molecules involved in plant growth regulation and development). The presentation reflects the historical development of analyses, beginning with bioassays and ending with novel immunochemical assays. (JN)

  17. Cyclic variations of high-frequency ultrasonic backscattering from blood under pulsatile flow.

    Science.gov (United States)

    Huang, Chih-Chung

    2009-08-01

    It was shown previously that ultrasonic scattering from whole blood varies during the flow cycle under pulsatile flow both in vitro and in vivo. It has been postulated that the cyclic variations of the backscattering signal are associated with red blood cell (RBC) aggregation in flowing whole blood. To obtain a better understanding of the relationship between blood backscattering and RBC aggregation behavior for pulsatile flowing blood, the present study used high-frequency ultrasound to characterize blood properties. The backscattering signals from both whole blood and an RBC suspension at different peak flow velocities (from 10 to 30 cm/s) and hematocrits (20% and 40%) under pulsatile flow (stroke rate of 20 beats/min) were measured with 3 single-element transducers at frequencies of 10, 35, and 50 MHz in a mock flow loop. To avoid the frequency response problem of a Doppler flowmeter, the integrated backscatter (IB) and flow velocity as functions of time were calculated directly using RF signals from flowing blood. The experimental results showed that cyclic variations of the IB curve were clearly observed at a low flow velocity and a hematocrit of 40% when using 50 MHz ultrasound, and that these variations became weaker as the peak flow velocity increased. However, these cyclic variations were detected only at 10 cm/s when using 10 MHz ultrasound. These results demonstrate that a high flow velocity can stop the formation of rouleaux and that a high hematocrit can promote RBC aggregation to produce cyclic variations of the backscattering signal under pulsatile flow. In addition, slight cyclic variations of the IB curve for an RBC suspension were observed at 35 and 50 MHz. Furthermore, the peak of the IB curve from whole blood led the peak of the velocity waveform when using high-frequency ultrasound, which could be explained by the assumption that a rapid flow can promote RBC aggregation under pulsatile flow. Together, the experimental results showed that the

  18. 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

  19. Dynamic, Sex-Differential STAT5 and BCL6 Binding to Sex-Biased, Growth Hormone-Regulated Genes in Adult Mouse Liver

    OpenAIRE

    Zhang, Yijing; Laz, Ekaterina V.; Waxman, David J.

    2012-01-01

    Sex-dependent pituitary growth hormone (GH) secretory patterns determine the sex-biased expression of >1,000 genes in mouse and rat liver, affecting lipid and drug metabolism, inflammation, and disease. A fundamental biological question is how robust differential expression can be achieved for hundreds of sex-biased genes simply based on the GH input signal pattern: pulsatile GH stimulation in males versus near-continuous GH exposure in females. STAT5 is an essential transcriptional mediator ...

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

    Energy Technology Data Exchange (ETDEWEB)

    Bok, Tae Hoon; Kong, Qi; Nam, Kweon Ho; Choi, Jay Chol; Paeng, Dong Guk [Department of Ocean System Engineering, Jeju National University, Jeju (Korea, Republic of)

    2012-10-15

    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.

  1. Dendro-dendritic bundling and shared synapses between gonadotropin-releasing hormone neurons

    OpenAIRE

    Campbell, Rebecca E.; Gaidamaka, Galina; Han, Seong-Kyu; Herbison, Allan E.

    2009-01-01

    The pulsatile release of gonadotropin-releasing hormone (GnRH) is critical for mammalian fertility, but the mechanisms underlying the synchronization of GnRH neurons are unknown. In the present study, the full extent of the GnRH neuron dendritic tree was visualized by patching and filling individual GnRH neurons with biocytin in acute brain slices from adult GnRH-green fluorescent protein (GFP) transgenic mice. Confocal analysis of 42 filled GnRH neurons from male and female adult mice reveal...

  2. Three-dimensional visualization of pulsatile tissue-motion in B-mode ultrasonogram of neonatal cranium

    Science.gov (United States)

    Fukuzawa, Masayuki; Kawaguchi, Hikari; Yamada, Masayoshi; Nakamori, Nobuyuki; Kitsunezuka, Yoshiki

    2009-02-01

    Pulsatile tissue-motion in the B-mode ultrasonogram of neonatal cranium has been visualized in the three-dimensional (3-D) domain. A movie of 2-D ultrasonogram (640×480pixels/frame, 8bits/pixel, 33ms/frame), which was taken with a conventional ultrasonogram apparatus (ATL HDI5000) and an ultrasonic probe combined with a compact tilt-sensor, was captured and recorded together with the orientations of probe into a 2-D visualization system developed by ourselves. The pulsatile strength was evaluated from a heartbeat-frequency component calculated by Fourier transform of a series of pixel values as a function of time sampled at each pixel of the 2-D ultrasonogram. The 3-D image of pulsatile strength was obtained by projecting the pulsatile strength on the several sections at different orientations of probe. The 3-D images of pulsatile-strength clearly described characteristic 3-D structures of arteries such as the anterior, middle and posterior cerebral arteries, Willis ring and cerebellar arteries. Since our technique is completely noninvasive, it is very useful for neonates rested completely at incubators. Furthermore, it is effective approach to obtain a useful 3-D ultrasonogram even in homogeneous tissues other than brain tissues, because it is easy to recognize the tissue boundary by selective detection of special tissues with their own motion characteristics.

  3. Hormone Health Network

    Science.gov (United States)

    ... reduce risk for other diseases The Hormone Health Network helps you and your health care provider have ... Copyright Endocrine Society. All rights reserved. Terms & Policies Network Partners The Hormone Health Network partners with other ...

  4. Hormones and Obesity

    Science.gov (United States)

    ... Balance › Hormones and Obesity Fact Sheet Hormones and Obesity March, 2010 Download PDFs English Espanol Editors Caroline Apovian, MD Judith Korner, MD, PhD What is obesity? Obesity is a chronic (long-term) medical problem ...

  5. Menopause and Hormones

    Science.gov (United States)

    ... 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 ...

  6. Hormones and Hypertension

    Science.gov (United States)

    Fact Sheet Hormones and Hypertension What is hypertension? Hypertension, or chronic (long-term) high blood pressure, is a main cause of ... tobacco, alcohol, and certain medications play a part. Hormones made in the kidneys and in blood vessels ...

  7. DEVELOPMENT OF BIPHASIC PULSATILE RELEASE MINI-TABLETS SYSTEM OF POORLY WATER SOLUBLE CARVEDILOL PHOSPHATE

    Directory of Open Access Journals (Sweden)

    D. K. Singh

    2015-05-01

    Full Text Available Objective: Carvedilol Phosphate is indicated for the treatment of mild-to-severe chronic heart failure of ischemic or cardiomyopathic origin. The ultimate goal of pulsatile release mini-tablets to deliver a drug to the specific site and then to maintain the desired plasma drug concentration at particular site in chronotherapeutic manner. Among solids, multiparticulate delivery have its own advantages. Pulsatile drug delivery system provides better therapy with many of the actives. Rupturable pulsatile mini-tablet consists of a drug core; swelling layer of a super disintegrant; an insoluble, water-permeable polymeric and enteric coating. Upon water access, the swellable layer expands, resulting in the rupturing of outer membrane followed by drug release. There were no drug release ob served in acid phase. The active pharmaceutical ingredient selected was Carvedilol Phosphate, in core mini-tablets. The second layer composed of swelling excipient, had crospovidone, Croscarmellose sodium and sodium starch glycolate. Third and the outer most layer was based on ethyl cellulose and enteric polymer. The release after lag time was fast and complete, when crospovidone was used as a swelling agent. In contrast, a sustained release was achieved after the lag time, when croscarmellose sodium and sodium starch glycolate were used as swelling agents. Fast release would be preferable in the present case. Optimal level of crospovidone to achieve a fast and complete release of Carvedilol phosphate was 30%. Outer membrane, formed using ethyl cellulose was suitable enough to rupture sufficiently ensuring fast drug release in upper portion of small intestine. It was possible to design multiparticulate of carvedilol phosphate having a suitable release profile.

  8. Atraumatic Pulsatile Leukocyte Circulation for Long-Term In Vitro Dynamic Culture and Adhesion Assays.

    Science.gov (United States)

    Mazza, Giulia; Stoiber, Martin; Pfeiffer, Dagmar; Schima, Heinrich

    2015-11-01

    Low flow rate pumping of cell suspensions finds current applications in bioreactors for short-term dynamic cell culture and adhesion assays. The aim of this study was to develop an atraumatic pump and hemodynamically adapted test circuit to allow operating periods of at least several hours. A computer-controlled mini-pump (MP) was constructed based on non-occlusive local compression of an elastic tube with commercial bi-leaflet valves directing the pulsatile flow into a compliant circuit. Cell damage and activation in the system were tested with whole blood in comparison with a set with a conventional peristaltic pump (PP). Activation of circulating THP-1 monocytes was tested by measuring the expression of CD54 (ICAM-1). Additionally, monocyte-endothelial interactions were monitored using a parallel-plate flow chamber with an artificial stenosis. The system required a priming volume of only 20 mL, delivering a peak pulsatile flow of up to 35 mL/min. After 8 h, blood hemolysis was significantly lower for MP with 11 ± 3 mg/dL compared with PP with 100 ± 16 mg/dL. CD142 (tissue factor) expression on blood monocytes was 50% lower for MP. With MP, THP-1 cells could be pumped for extended periods (17 h), with no enhanced expression of CD54 permitting the long-term co-culture of THP-1 with endothelial cells and the analysis of flow pattern effects on cell adhesion. A low-damage assay setup was developed, which allows the pulsatile flow of THP-1 cells and investigation of their interaction with other cells or surfaces for extended periods of time. PMID:25894522

  9. Detecting spatial variations of erythrocytes by ultrasound backscattering statistical parameters under pulsatile flow.

    Science.gov (United States)

    Huang, Chih-Chung

    2011-05-01

    The echogenicity of whole blood is known to vary during the flow cycle under pulsatile flow both in vitro and in vivo. However, the fundamental underlying mechanisms remain uncertain. The combined effects of flow acceleration and the shear rate were recently used to explain the cyclic variations of signals backscattered from flowing blood. However, testing this hypothesis requires determination of the spatial distributions of red blood cells (RBCs) in flowing blood. Recently, the Nakagami (m) and scaling (Ω) parameters have been used, respectively, to detect the spatial distributions of RBCs and the intensity of backscattering signal from blood under steady flow. For a better understanding of the relationship between the spatial distributions of RBCs and erythrocyte aggregation under pulsatile flow condition, these ultrasound backscattering statistical parameters were used, in this study, to characterize signals backscattered from both whole blood and RBC suspensions at different peak flow velocities (from 10 to 30 cm/s) and hematocrits (20% and 40%). The experiments were carried out by a 35-MHz ultrasound transducer. The m and Ω parameters were calculated for different blood properties and conditions, and the flow velocity in the center of blood flowing through a tube was measured synchronously. In whole blood, the results demonstrated that most RBCs were aggregated progressively toward the center of tube as the flow velocity started to accelerate, and that the increase in the intensity of the backscattered signal envelope to a maximum was attributable to larger rouleaux being formed in the center of tube. This phenomenon became apparent at a lower peak flow velocity with 40% hematocrit. However, there were no cyclic and spatial variations of the backscattering signal over a pulsatile cycle in RBC suspensions. PMID:21134805

  10. Hormone therapy in acne

    OpenAIRE

    Chembolli Lakshmi

    2013-01-01

    Underlying hormone imbalances may render acne unresponsive to conventional therapy. Relevant investigations followed by initiation of hormonal therapy in combination with regular anti-acne therapy may be necessary if signs of hyperandrogenism are present. In addition to other factors, androgen-stimulated sebum production plays an important role in the pathophysiology of acne in women. Sebum production is also regulated by other hormones, including estrogens, growth hormone, insulin, insulin-l...

  11. A Pulsatile Flow Phantom for Image-Guided HIFU Hemostasis of Blood Vessels

    International Nuclear Information System (INIS)

    A pulsatile flow phantom for studying ultrasound image-guided acoustic hemostasis in a controlled environment has been developed. An ex vivo porcine carotid artery was attached to the phantom and embedded in a visually and ultrasonically transparent gel. Heparinized porcine blood was pumped through the phantom. Power-Doppler and B-mode ultrasound were used to remotely target the HIFU focus to the site of a needle puncture. In nine trials, complete hemostasis was achieved after an average HIFU application of 55 +/- 34 seconds. The vessels remained patent after treatment. With this phantom, it will be possible to do controlled studies of ultrasound image-guided acoustic hemostasis

  12. Pulsatile flow with heat transfer of dusty magnetohydrodynamic Ree-Eyring fluid through a channel

    Energy Technology Data Exchange (ETDEWEB)

    Shawky, Hameda Mohammed [Faculty of Women, AL-Azhar University, Department of Mathematics, Cairo (Egypt)

    2009-08-15

    The flow due to the pulsatile pressure gradient of dusty non-Newtonian fluid with heat transfer in a channel is considered. The system is stressed by an external magnetic field. The non-Newtonian fluid under consideration is obeying the rheological equation of state due to Ree-Eyring's stress-strain relation. The equations of momentum and energy have been solved by using Lightill method. The velocity and temperature distributions of the two phase of the dusty fluid are obtained. The effects of various physical parameters of distributions the problem on these distributions are discussed and illustrated graphically through a set of figure. (orig.)

  13. Effect of Applied Magnetic Field on Pulsatile Flow of Blood in a Porous Channel

    Directory of Open Access Journals (Sweden)

    Sarfraz Ahmed

    2011-11-01

    Full Text Available An approximate solution is presented to the problem of pulsatile flow of blood in porous channel in presence of induced magnetic field. The blood is assumed to be an incompressible Non Newtonian fluid. To reduce the equation of motion to an ordinary differential equation, a dimensionless variable is used. Numerical results were obtained for different values of the magnetic parameter, frequency parameter and Reynolds number. It is observed that when the magnetic parameter, the Hartmann number increases, the velocity as well as magnitude of mass flux decreases. For non magnetic case the paper reduces to the problem investigated by Wang

  14. Frequency-Dependent Neural Activity in Patients with Unilateral Vascular Pulsatile Tinnitus

    OpenAIRE

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

    2016-01-01

    Previous resting-state functional magnetic resonance imaging (rs-fMRI) studies have shown that neurological changes are important findings in vascular pulsatile tinnitus (PT) patients. Here, we utilized rs-fMRI to measure the amplitude of low-frequency fluctuations (ALFF) in forty patients with unilateral PT and forty age-, gender-, and education-matched normal control subjects. Two different frequency bands (slow-4, 0.027–0.073 Hz, and slow-5, 0.010–0.027 Hz, which are more sensitive to subc...

  15. Neoglycoenzyme-Gated Mesoporous Silica Nanoparticles: Toward the Design of Nanodevices for Pulsatile Programmed Sequential Delivery.

    Science.gov (United States)

    Díez, Paula; Sánchez, Alfredo; de la Torre, Cristina; Gamella, María; Martínez-Ruíz, Paloma; Aznar, Elena; Martínez-Máñez, Ramón; Pingarrón, José M; Villalonga, Reynaldo

    2016-03-01

    We report herein the design of a stimulus-programmed pulsatile delivery system for sequential cargo release based on the use of a lactose-modified esterase as a capping agent in phenylboronic acid functionalized mesoporous silica nanoparticles. The dual-release mechanism was based on the distinct stability of the cyclic boronic acid esters formed with lactose residues and the long naturally occurring glycosylation chains in the modified neoglycoenzyme. Cargo delivery in succession was achieved using glucose and ethyl butyrate as triggers. PMID:26966914

  16. Integration of pulsatile gonadotropin secretion by timed urinary measurements: an accurate and sensitive 3-hour test

    International Nuclear Information System (INIS)

    The integration of pulsatile gonadotropin secretion by the radioimmunoassay of an acetone precipitation from a short-term urine sample was evaluated. FSH and LH excretion over a 3-h period was compared to the mean level of 10 blood samples obtained every 20 min for a similar time period from 71 patients. A highly significant correlation existed between blood and urine results. In addition, the gonadotropin levels obtained from a 3-h sample correlated well with the 24-h excretion of FSH and LH from the same individual. A 3-h urine collection can provide a simple, sensitive, and accurate means of assessing circulating FSH and LH levels. (U.S.)

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

    International Nuclear Information System (INIS)

    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)

  18. Computational Fluid Dynamics Analysis of Pulsatile Blood Flow Behavior in Modelled Stenosed Vessels with Different Severities

    OpenAIRE

    Mohsen Mehrabi; Saeed Setayeshi

    2012-01-01

    This study focuses on the behavior of blood flow in the stenosed vessels. Blood is modelled as an incompressible non-Newtonian fluid which is based on the power law viscosity model. A numerical technique based on the finite difference method is developed to simulate the blood flow taking into account the transient periodic behaviour of the blood flow in cardiac cycles. Also, pulsatile blood flow in the stenosed vessel is based on the Womersley model, and fluid flow in the lumen region is gove...

  19. Pulsatile microfluidics as an analytical tool for determining the dynamic characteristics of microfluidic systems

    DEFF Research Database (Denmark)

    Vedel, Søren; Olesen, Laurits Højgaard; Bruus, Henrik

    2010-01-01

    An understanding of all fluid dynamic time scales is needed to fully understand and hence exploit the capabilities of fluid flow in microfluidic systems. We propose the use of harmonically oscillating microfluidics as an analytical tool for the deduction of these time scales. Furthermore, we......-filled interconnected elastic microfluidic tubes containing a large, trapped air bubble and driven by a pulsatile pressure difference. We demonstrate good agreement between the system-level model and the experimental results, allowing us to determine the dynamic time scales of the system. However, the generic analysis...... can be applied to all microfluidic systems, both ac and dc....

  20. A Case of Pulsatile Tinnitus from the Atherosclerosis and Atheroma in Superior Labial Artery and Facial Artery

    Science.gov (United States)

    Kim, Jung Min; Kim, Choon Dong

    2012-01-01

    Tinnitus is one of the most common symptoms in an audiologic field. It can be classified as either as subjective or objective; former referring to the sensation heard by both patient and examiner. Pulsatile tinnitus is perceived as sounds that vary in frequency, intensity and duration. The cause of pulsatile tinnitus include high jugular bulb, benign intracranial hypertension, glomus tumors, carotid artery stenosis, vascular lesions of the temporal bone, arteriovenous malformation, aneurysms, and Arnold-Chiari malformation. Vascular tinnitus is most common (7.6%). Recently, the authors experienced one case of the pulsatile tinnitus caused by atherosclerosis and atheroma in superior labial artery & facial artery. After surgery, the symptom had disappeared. We report a unique case regarding the objective tinnitus with the literature review. PMID:24653894

  1. Pulsatile Support Mode of BJUT-II Ventricular Assist Device (VAD) has Better Hemodynamic Effects on the Aorta than Constant Speed Mode: A Primary Numerical Study.

    Science.gov (United States)

    Gu, Kaiyun; Gao, Bin; Chang, Yu; Zeng, Yi

    2016-01-01

    BACKGROUND BJUT-II VAD is a novel left ventricular assist device (LVADs), directly implanted into the ascending aorta. The pulsatile support mode is proposed to achieve better unloading performance than constant speed mode. However, the hemodynamic effects of this support mode on the aorta are still unclear. The aim of this study was to clarify the hemodynamic effects BJUT-II VAD under pulsatile support mode on the aorta. MATERIAL AND METHODS Computational fluid dynamics (CFD) studies, based on a patient-specific aortic geometric model, were conducted. Wall shear stress (WSS), averaged WSS (avWSS), oscillatory shear index (OSI), and averaged helicity density (Ha) were calculated to compare the differences in hemodynamic effects between pulsatile support mode and constant speed mode. RESULTS The results show that avWSS under pulsatile support mode is significantly higher than that under constant speed mode (0.955Pa vs. 0.675Pa). Similarly, the OSI value under pulsatile mode is higher than that under constant speed mode (0.104 vs. 0.057). In addition, Ha under pulsatile mode for all selected cross-sections is larger than that under constant mode. CONCLUSIONS BJUT-II VAD, under pulsatile control mode, may prevent atherosclerosis lesions and aortic remodeling. The precise effects of pulsatile support mode on atherosclerosis and aortic remodeling need to be further studied in animal experiments. PMID:27363758

  2. The decline in pulsatile GH secretion throughout early adulthood in mice is exacerbated by dietary-induced weight gain.

    Science.gov (United States)

    Huang, L; Steyn, F J; Tan, H Y; Xie, T Y; Veldhuis, J D; Ngo, S T; Chen, C

    2012-09-01

    The transition between puberty and adulthood is accompanied by a slowing in linear growth. Although GH is a key factor that drives somatic development into adulthood, early adulthood coincides with a reduction in circulating levels of GH. To this extent, a pathological decline in postpubertal GH secretion is detrimental to attainment of peak lean muscle mass and bone mass and promotes adiposity and increases susceptibility to the development of obesity in adulthood. Here we characterized pulsatile GH secretion in C57BL/6J mice at 12 and 16 wk of age. Deconvolution analysis of these measures reveals a reduction in pulsatile GH secretion between 12 and 16 wk of age. Dietary intervention with high-fat feeding at 8 wk of age results in a significant increase in adiposity, the development of glucose intolerance, and hyperinsulinemia. We show the exacerbation of the age-associated decline in pulsatile GH secretion in high-fat-fed mice after 4 wk of dietary intervention (at 12 wk of age), and a further suppression of pulsatile GH secretion by 8 wk of dietary intervention (at 16 wk of age). Suppressed pulsatile secretion of GH did not coincide with an elevation in circulating free fatty acids. Rather, we observed increased hepatic triglyceride content and an eventual decrease in circulating levels of IGF-I. Given the established role of GH in maintaining healthy aging, we anticipate that an advancing of the age-associated decline in pulsatile GH secretion as a consequence of dietary-induced weight gain may have long-term ramifications on adult health. PMID:22802464

  3. Pulsatile microvascular blood flow imaging by short-time Fourier transform analysis of ultrafast laser holographic interferometry

    CERN Document Server

    Puyo, L; Rancillac, A; Simonutti, M; Paques, M; Sahel, J A; Fink, M; Atlan, M

    2015-01-01

    We report on wide-field imaging of pulsatile microvascular blood flow in the exposed cerebral cortex of a mouse by holographic interferometry. We recorded interferograms of laser light backscattered by the tissue, beating against an off-axis reference beam with a 50 kHz framerate camera. Videos of local Doppler contrasts were rendered numerically by Fresnel transformation and short-time Fourier transform analysis. This approach enabled instantaneous imaging of pulsatile blood flow contrasts in superficial blood vessels over 256 x 256 pixels with a spatial resolution of 10 microns and a temporal resolution of 20 ms.

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

    OpenAIRE

    Vemula, Sateesh Kumar

    2015-01-01

    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...

  5. Hormones, genes, and behavior

    OpenAIRE

    Pfaff, Donald W.

    1997-01-01

    With assays of hormone-sensitive behaviors, it is possible to demonstrate both direct and indirect actions of genes on mammalian social behaviors. Direct effects of estrogen receptor gene expression and progesterone receptor gene expression figure prominently in well analyzed neuroendocrine mechanisms for sex behavior, operating through a neural circuit that has been delineated. Indirect effects, notably the consequences of sexual differentiation, display complex d...

  6. Hormonal therapies in acne.

    Science.gov (United States)

    Shaw, James C

    2002-07-01

    Hormones, in particular androgen hormones, are the main cause of acne in men, women, children and adults, in both normal states and endocrine disorders. Therefore, the use of hormonal therapies in acne is rational in concept and gratifying in practice. Although non-hormonal therapies enjoy wide usage and continue to be developed, there is a solid place for hormonal approaches in women with acne, especially adult women with persistent acne. This review covers the physiological basis for hormonal influence in acne, the treatments that are in use today and those that show promise for the future. The main treatments to be discussed are oral contraceptives androgen receptor blockers like spironolactone and flutamide, inhibitors of the enzyme 5 alpha-reductase and topical hormonal treatments. PMID:12083987

  7. Pulsatile arginine vasopressin release from the rat hypothalamo neurohypophyseal system during osmotic stimulation.

    Directory of Open Access Journals (Sweden)

    Ohno,Norihito

    1981-06-01

    Full Text Available Arginine vasopressin (AVP was released in vitro in a pulsatile pattern from the hypothalamo-neurohypophyseal system (HNS and from the hypothalamus during continuous hyperosmotic stimuli with NaCl or fructose. No significant difference was found in the AVP pulse frequency between the two kinds of hyperosmotic agents. AVP was released from the HNS in a dose-related manner under NaCl stimulation. When the neural lobe was stimulated with NaCl or fructose, a clear AVP pulse pattern was not apparent. Urea failed to evoke a significant AVP release from the neural lobe or HNS. A stepwise increase in NaCl stimulation from 5 to 25 mEq induced a AVP response from the HNS and hypothalamus similar to that under constant stimulation at 25 mEq NaCl. This phenomenon was also found with fructose or sucrose. These results suggest that AVP release from the HNS during continuous osmotic stimulation has a pulsatile pattern regardless of the hyperosmotic substance or osmotic pressure. This AVP release accurately reflects the physiological function of the hypothalamus without modulation in the neural lobe. These results also suggest that the total amount of AVP was related to the osmotic pressure or the osmotic substance but that the frequency of the pulse release was not, moreover, that the AVP release depends not only on the absolute osmotic pressure, but also on the changing rate of osmotic pressure.

  8. 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.

  9. 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. PMID:26983961

  10. Formulating SLMs as oral pulsatile system for potential delivery of melatonin to pediatric population.

    Science.gov (United States)

    Albertini, Beatrice; Di Sabatino, Marcello; Melegari, Cecilia; Passerini, Nadia

    2014-07-20

    The formulation development of melatonin (MLT) for infants and children with neurodevelopmental difficulties was fully investigated. This population have a higher prevalence of sleep disorders and present special challenges for drug administration and swallowing. To solve these issues, solid lipid microparticles (SLMs) were designed to obtain an oral flexible dosage form constituted by GRAS excipients and a free flow pulsatile delivery system for MLT, able to maintain its release through 8h. Three groups of SLMs were produced by spray congealing and characterized as regards particle size, morphology, flowability, solid state, drug content and release behavior. The SLMs manipulation with milk and yogurt and the MLT stability in these foods were also investigated. Microparticles with different excipient composition were selected to obtain a pulsatile release pattern over 8h. The final delivery platform displayed a prompt release from group I SLMs together with a lag phase of groups II and III SLMs, followed by a repeated MLT release from group II and a prolonged MLT release related to the last group. Finally, MLT was compatible and stable in milk and yogurt suggesting that microparticles sprinkled into food is acceptable for MLT administration to children unable to swallow capsules or tablets. PMID:24768728

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

    International Nuclear Information System (INIS)

    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

  12. Enteric-coating of pulsatile-release HPC capsules prepared by injection molding.

    Science.gov (United States)

    Macchi, E; Zema, L; Maroni, A; Gazzaniga, A; Felton, L A

    2015-04-01

    Capsular devices based on hydroxypropyl cellulose (Klucel® LF) intended for pulsatile release were prepared by injection molding (IM). In the present work, the possibility of exploiting such capsules for the development of colonic delivery systems based on a time-dependent approach was evaluated. For this purpose, it was necessary to demonstrate the ability of molded cores to undergo a coating process and that coated systems yield the desired performance (gastric resistance). Although no information was available on the coating of IM substrates, some issues relevant to that of commercially-available capsules are known. Thus, preliminary studies were conducted on molded disks for screening purposes prior to the spray-coating of HPC capsular cores with Eudragit® L 30 D 55. The ability of the polymeric suspension to wet the substrate, spread, start penetrating and initiate hydration/swelling, as well as to provide a gastroresistant barrier was demonstrated. The coating of prototype HPC capsules was carried out successfully, leading to coated systems with good technological properties and able to withstand the acidic medium with no need for sealing at the cap/body joint. Such systems maintained the original pulsatile release performance after dissolution of the enteric film in pH 6.8 fluid. Therefore, they appeared potentially suitable for the development of a colon delivery platform based on a time-dependent approach. PMID:25585355

  13. Design and in vitro evaluation of compression-coated pulsatile release tablets of losartan potassium

    Directory of Open Access Journals (Sweden)

    M Bajpai

    2012-01-01

    Full Text Available In majority of individuals blood pressure rises in the early morning hours, which lead to serious cardiovascular complications. Formulation of pulsatile system makes it possible to deliver drug at definite period of time when symptoms of the disease condition are most critical. The purpose of the present work was to develop pulsatile release tablet of losartan potassium for chronotherapy in hypertension. The prepared system consisted of a core tablet coated with versatile and safe hydrophilic cellulosic ethers such as, hydroxypropyl methylcellulose, hydroxypropyl cellulose and sodium carboxy methylcellulose to produce burst release after predetermined lag time. Various formulation factors were studied through series of test and in vitro dissolution study. It was found that core tablets containing superdisintegrant failed to produce burst drug release pattern while effervescent agent was able to do so. Results also reveal that coating composition and coating level affects lag time. Formulation containing effervescent agent in core and coated with 200 mg hydroxypropyl cellulose provide lag time of 4.5 h with 73% drug release in 6 h that followed a sigmoidal release pattern. These values were close to the desired objective of producing lag time of 5-6 h followed by fast drug release. This approach can thus provide a useful means for timed release of losartan and is helpful for patients with morning surge.

  14. Pulsatile flow simulator for comparison of cardiac output measurements by electromagnetic flow meter and thermodilution.

    Science.gov (United States)

    Jebson, P J; Karkow, W S

    1986-01-01

    This study examined a pulsatile flow simulator for the purpose of evaluating two measurement devices, an extracorporeal flow probe with an electromagnetic flow meter and several thermodilution catheters. We measured the performance of these devices in a range of low to high flows. Using either saline or blood as a perfusate, we obtained different results with these fluids (p less than 0.001). Each catheter behaved in a linear manner, although variation occurred among the catheters with both saline (minimum slope 1.090, maximum slope 1.190) and blood (minimum slope 1.107, maximum slope 1.154). An increase in rate and stroke volumes of the simulator did not demonstrate an identifiable trend in error. The thermodilution catheters were most accurate at 5.0 L/min irrespective of rate, stroke volume, or perfusate used. In contrast, the electromagnetic flow meter accurately represented flows across the wide range of outputs examined (2.4 to 10.7 L/min). (Slope with saline 1.091, slope with blood 1.080) Throughout the range of flow, the flow meter gave a calibration line 5% higher with blood than with saline. The results indicate that accurate measurement of pulsatile blood flow can be achieved in vitro with an electromagnetic flow meter using saline as a perfusate, provided a correction factor is determined and applied to convert values for saline to accurate values for blood. PMID:2940345

  15. Elderly depression diagnostic of diabetic patients by brain tissue pulsatility imaging

    Science.gov (United States)

    Hachemi, Mélouka Elkateb; Remeniéras, Jean-pierre; Desmidt, Thomas; Camus, Vincent; Tranquart, François

    2010-01-01

    Pulsatile motion of brain parenchyma results from cardiac and breathing cycles and consists in a rapid displacement in systole, with slow diastolic recovery. Based on the vascular depression concept and recent studies where a correlation was found between cerebral haemodynamics and depression in the elderly, we emitted the hypothesis that tissue brain motion due to perfusion is correlated to elderly depression associated with cardiovascular risk factors. Tissue Pulsatlity Imaging (TPI) is a new ultrasound technique developed firstly at the University of Washington to assess the brain tissue motion. We used TPI technique to measure the brain displacement of two groups of elderly patients with diabetes as a vascular risk factor. The first group is composed of 11 depressed diabetic patients. The second group is composed of 12 diabetic patients without depressive symptoms. Transcranial acquisitions were performed with a 1.8 MHz ultrasound phased array probe through the right temporal bone window. The acquisition of six cardiac cycles was realized on each patient with a frame rate of 23 frames/s. Displacements estimation was performed by off-line analysis. A significant decrease in brain pulsatility was observed in the group of depressed patients compared to the group of non depressed patients. Mean displacement magnitude was about 44±7 μm in the first group and 68±13 μm in the second group.

  16. Flow dynamics in anatomical models of abdominal aortic aneurysms: computational analysis of pulsatile flow.

    Science.gov (United States)

    Finol, Ender A; Amon, Cristina H

    2003-01-01

    Blood flow in human arteries is dominated by time-dependent transport phenomena. In particular, in the abdominal segment of the aorta under a patient's average resting conditions, blood exhibits laminar flow patterns that are influenced by secondary flows induced by adjacent branches and in irregular vessel geometries. The flow dynamics becomes more complex when there is a pathological condition that causes changes in the normal structural composition of the vessel wall, for example, in the presence of an aneurysm. An aneurysm is an irreversible dilation of a blood vessel accompanied by weakening of the vessel wall. This work examines the importance of hemodynamics in the characterization of pulsatile blood flow patterns in individual Abdominal Aortic Aneurysm (AAA) models. These patient-specific computational models have been developed for the numerical simulation of the momentum transport equations utilizing the Finite Element Method (FEM) for the spatial and temporal discretization. We characterize pulsatile flow dynamics in AAAs for average resting conditions by means of identifying regions of disturbed flow and quantifying the disturbance by evaluating wall pressure and wall shear stresses at the aneurysm wall. PMID:14515766

  17. Hormones and the pilosebaceous unit

    OpenAIRE

    Chen, Wen-Chieh; Zouboulis, Christos C

    2009-01-01

    Hormones can exert their actions through endocrine, paracrine, juxtacrine, autocrine and intracrine pathways. The skin, especially the pilosebaceous unit, can be regarded as an endocrine organ meanwhile a target of hormones, because it synthesizes miscellaneous hormones and expresses diverse hormone receptors. Over the past decade, steroid hormones, phospholipid hormones, retinoids and nuclear receptor ligands as well as the so-called stress hormones have been demonstrated to play pivotal rol...

  18. Multidetector CT imaging of mechanical prosthetic heart valves: quantification of artifacts with a pulsatile in-vitro model

    NARCIS (Netherlands)

    Symersky, P.; Budde, R.P.; Westers, P.; Mol, B.A. de; Prokop, M.

    2011-01-01

    OBJECTIVES: Multidetector computed tomography (MDCT) can detect the cause of prosthetic heart valve (PHV) dysfunction but is hampered by valve-induced artifacts. We quantified artifacts of four PHV using a pulsatile in-vitro model and assessed the relation to leaflet motion and valve design. METHODS

  19. Multidetector CT imaging of mechanical prosthetic heart valves : quantification of artifacts with a pulsatile in-vitro model

    NARCIS (Netherlands)

    Symersky, Petr; Budde, Ricardo P. J.; Westers, Paul; de Mol, Bas A. J. M.; Prokop, Mathias

    2011-01-01

    Objectives Multidetector computed tomography (MDCT) can detect the cause of prosthetic heart valve (PHV) dysfunction but is hampered by valve-induced artifacts. We quantified artifacts of four PHV using a pulsatile in-vitro model and assessed the relation to leaflet motion and valve design. Methods

  20. Multidetector CT imaging of mechanical prosthetic heart valves: quantification of artifacts with a pulsatile in-vitro model

    NARCIS (Netherlands)

    P. Symersky; R.P.J. Budde; P. Westers; B.A.J.M. de Mol; M. Prokop

    2011-01-01

    Multidetector computed tomography (MDCT) can detect the cause of prosthetic heart valve (PHV) dysfunction but is hampered by valve-induced artifacts. We quantified artifacts of four PHV using a pulsatile in-vitro model and assessed the relation to leaflet motion and valve design. A Medtronic Hall ti

  1. First-trimester measurement of the ductus venosus pulsatility index and the prediction of congenital heart defects

    NARCIS (Netherlands)

    Timmerman, E.; Clur, S. A.; Pajkrt, E.; Bilardo, C. M.

    2010-01-01

    Objective This study was carried out to evaluate the additional predictive value of ductus venosus pulsatility index for veins (DV-PIV) in the identification of congenital heart defects (CHDs) in fetuses with an enlarged nuchal translucency (NT) and a normal karyotype. Methods All chromosomally norm

  2. Clinical Effectiveness of Centrifugal Pump to Produce Pulsatile Flow During Cardiopulmonary Bypass in Patients Undergoing Cardiac Surgery

    NARCIS (Netherlands)

    Gu, Y. John; van Oeveren, Willem; Mungroop, Hubert E.; Epema, Anne H.; den Hamer, Inez J.; Keizer, Jorrit J.; Leuvenink, Ron P.; Mariani, Massimo A.; Rakhorst, Gerhard

    2011-01-01

    Although the centrifugal pump has been widely used as a nonpulsatile pump for cardiopulmonary bypass (CPB), little is known about its performance as a pulsatile pump for CPB, especially on its efficacy in producing hemodynamic energy and its clinical effectiveness. We performed a study to evaluate w

  3. 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 dis

  4. Need for Comprehensive Hormonal Workup in the Management of Adrenocortical Tumors in Children

    OpenAIRE

    Gönç, E. Nazlı; Özön, Zeynep Alev; Çakır, Meltem Didem; Alikaşifoğlu, Ayfer; Kandemir, Nurgün

    2014-01-01

    Ob­jec­ti­ve: Clinical findings do not reflect the excess hormonal status in adrenocortical tumors (ACTs) in children. Identification of abnormal hormone secretion may help provide the tumor marker and delineate those patients with a risk of adrenal suppression following tumor removal. To analyze the impact of complete hormonal assessment regardless of the clinical presentation in hormone-secreting ACTs in childhood. Methods: Association of hormonal workup at diagnosis with the clinical findi...

  5. A Reevaluation of the Question: Is the Pubertal Resurgence in Pulsatile GnRH Release in the Male Rhesus Monkey (Macaca mulatta) Associated With a Gonad-Independent Augmentation of GH Secretion?

    Science.gov (United States)

    Shahab, M; Trujillo, M Vargas; Plant, T M

    2015-10-01

    A somatic signal has been posited to trigger the pubertal resurgence in pulsatile GnRH secretion that initiates puberty in highly evolved primates. That GH might provide such a signal emerged in 2000 as a result of a study reporting that circulating nocturnal GH concentrations in castrated juvenile male monkeys increased in a 3-week period immediately preceding the pubertal resurgence of LH secretion. The present study was conducted to reexamine this intriguing relationship, again in an agonadal model. Four castrated juvenile male monkeys were implanted with indwelling jugular catheters, housed in remote sampling cages, and subjected to 24 hours of sequential blood sampling (every 30 min) every 2 weeks from 19.5 to 22 months of age. Twenty-four-hour profiles of circulating GH concentrations were analyzed using the pulse detection algorithm, PULSAR, and developmental changes in pulsatile GH release with respect to the initiation of the pubertal rise of LH secretion (week 0; observed between 22.5 and 32 mo of age) were examined for significance by a repeated-measures ANOVA. Changes in the parameters of pulsatile GH secretion, including mean 24-hour GH concentration and GH pulse frequency and pulse amplitude for 3 (n = 4) and 6 (n = 3) months before week 0 were unremarkable and nonsignificant. These findings fail to confirm those of the earlier study and lead us to conclude that the timing of the pubertal resurgence of GnRH release in the male monkey is not dictated by GH. Reasons for the discrepancy between the two studies are unclear. PMID:26181107

  6. Hormonal therapy for acne.

    Science.gov (United States)

    George, Rosalyn; Clarke, Shari; Thiboutot, Diane

    2008-09-01

    Acne affects more than 40 million people, of which more than half are women older than 25 years of age. These women frequently fail traditional therapy and have high relapse rates even after isotretinoin. Recent advances in research have helped to delineate the important role hormones play in the pathogenesis of acne. Androgens such as dihydrotestosterone and testosterone, the adrenal precursor dehydroepiandrosterone sulfate, estrogens, growth hormone, and insulin-like growth factors may all contribute to the development of acne. Hormonal therapy remains an important part of the arsenal of acne treatments available to the clinician. Women dealing with acne, even those without increased serum androgens, may benefit from hormonal treatments. The mainstays of hormonal therapy include oral contraceptives and antiandrogens such as spironolactone, cyproterone acetate, or flutamide. In this article, we discuss the effects of hormones on the pathogenesis of acne, evaluation of women with suspected endocrine abnormalities, and the myriad of treatment options available. PMID:18786497

  7. Hormones and endometrial carcinogenesis.

    Science.gov (United States)

    Kamal, Areege; Tempest, Nicola; Parkes, Christina; Alnafakh, Rafah; Makrydima, Sofia; Adishesh, Meera; Hapangama, Dharani K

    2016-02-01

    Endometrial cancer (EC) is the commonest gynaecological cancer in the Western World with an alarmingly increasing incidence related to longevity and obesity. Ovarian hormones regulate normal human endometrial cell proliferation, regeneration and function therefore are implicated in endometrial carcinogenesis directly or via influencing other hormones and metabolic pathways. Although the role of unopposed oestrogen in the pathogenesis of EC has received considerable attention, the emerging role of other hormones in this process, such as androgens and gonadotropin-releasing hormones (GnRH) is less well recognised. This review aims to consolidate the current knowledge of the involvement of the three main endogenous ovarian hormones (oestrogens, progesterone and androgens) as well as the other hormones in endometrial carcinogenesis, to identify important avenues for future research. PMID:26966933

  8. Adult growth hormone deficiency

    OpenAIRE

    Vishal Gupta

    2011-01-01

    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...

  9. Modelling plant hormone gradients.

    OpenAIRE

    S. Moore; Zhang, X.; Liu, J; Lindsey, K.

    2015-01-01

    Cellular patterning in the Arabidopsis root is coordinated via a localised auxin concentration maximum in the root tip, requiring the regulated expression of specific genes. The activities of plant hormones such as auxin, ethylene and cytokinin depend on cellular context and exhibit either synergistic or antagonistic interactions. Due to the complexity and nonlinearity of spatiotemporal interactions between both hormones and gene expression in root development, modelling plant hormone gradien...

  10. 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. PMID:26017285

  11. Using Cox cluster processes to model latent pulse location patterns in hormone concentration data.

    Science.gov (United States)

    Carlson, Nichole E; Grunwald, Gary K; Johnson, Timothy D

    2016-04-01

    Many hormones, including stress hormones, are intermittently secreted as pulses. The pulsatile location process, describing times when pulses occur, is a regulator of the entire stress system. Characterizing the pulse location process is particularly difficult because the pulse locations are latent; only hormone concentration at sampled times is observed. In addition, for stress hormones the process may change both over the day and relative to common external stimuli. This potentially results in clustering in pulse locations across subjects. Current approaches to characterizing the pulse location process do not capture subject-to-subject clustering in locations. Here we show how a Bayesian Cox cluster process may be adapted as a model of the pulse location process. We show that this novel model of pulse locations is capable of detecting circadian rhythms in pulse locations, clustering of pulse locations between subjects, and identifying exogenous controllers of pulse events. We integrate our pulse location process into a model of hormone concentration, the observed data. A spatial birth-and-death Markov chain Monte Carlo algorithm is used for estimation. We exhibit the strengths of this model on simulated data and adrenocorticotropic and cortisol data collected to study the stress axis in depressed and non-depressed women. PMID:26553914

  12. Pulsatile microfluidics as an analytical tool for determining the dynamic characteristics of microfluidic systems

    International Nuclear Information System (INIS)

    An understanding of all fluid dynamic time scales is needed to fully understand and hence exploit the capabilities of fluid flow in microfluidic systems. We propose the use of harmonically oscillating microfluidics as an analytical tool for the deduction of these time scales. Furthermore, we suggest the use of system-level equivalent circuit theory as an adequate theory of the behavior of the system. A novel pressure source capable of operation in the desired frequency range is presented for this generic analysis. As a proof of concept, we study the fairly complex system of water-filled interconnected elastic microfluidic tubes containing a large, trapped air bubble and driven by a pulsatile pressure difference. We demonstrate good agreement between the system-level model and the experimental results, allowing us to determine the dynamic time scales of the system. However, the generic analysis can be applied to all microfluidic systems, both ac and dc.

  13. Estimation of pressure gradients in pulsatile flow from magnetic resonance acceleration measurements.

    Science.gov (United States)

    Tasu, J P; Mousseaux, E; Delouche, A; Oddou, C; Jolivet, O; Bittoun, J

    2000-07-01

    A method for estimating pressure gradients from MR images is demonstrated. Making the usual assumption that the flowing medium is a Newtonian fluid, and with appropriate boundary conditions, the inertial forces (or acceleration components of the flow) are proportional to the pressure gradients. The technique shown here is based on an evaluation of the inertial forces from Fourier acceleration encoding. This method provides a direct measurement of the total acceleration defined as the sum of the velocity derivative vs. time and the convective acceleration. The technique was experimentally validated by comparing MR and manometer pressure gradient measurements obtained in a pulsatile flow phantom. The results indicate that the MR determination of pressure gradients from an acceleration measurement is feasible with a good correlation with the true measurements (r = 0.97). The feasibility of the method is demonstrated in the aorta of a normal volunteer. Magn Reson Med 44:66-72, 2000. PMID:10893523

  14. Doppler ultrasound for assessment of pulsatility index variation of middle cerebral artery in intrauterine growth retardation

    International Nuclear Information System (INIS)

    To assess variation of pulsatility index of middle cerebral artery (MCA-PI) in intrauterine growth retardation (IUGR). Study Design: Descriptive study. Place and Duration of Study: The study was conducted in department of Radiology, Combined Military Hospital Lahore, from March 2006 to September 2006. Patients and Method: A total 100 patients with IUGR in third trimester were selected. Ultrasound estimation of fetal weight (using fetal biometry) below 10th percentile for that gestational age was labeled as IUGR. MCA-PI value of less than 0.751 was labeled as abnormal. Result: Abnormal values of PI-MCA were found in 79% of IUGR cases while 21% had normal values. Conclusion: PI-MCA is a sensitive modality of assessing IUGR. (author)

  15. Development and Evaluation of Dual Cross-Linked Pulsatile Beads for Chronotherapy of Rheumatoid Arthritis

    Directory of Open Access Journals (Sweden)

    Abanesh kumar Bansal

    2013-01-01

    Full Text Available In the present investigation, pulsatile release beads were prepared by ionic gelation technique. Lornoxicam dual cross-linked beads were prepared by dropping dispersed phase of lornoxicam, pectin, and sodium alginate into the dispersion phase of different concentrations of calcium chloride solution followed by aluminium chloride solution. The formulated beads were further coated by Eudragit L & S 100 in the ratio 1 : 2 w/w in order to achieve desired lag time. In vitro release study showed lag time of 5–8 h before release of lornoxicam from the formulated beads. Thus, formulated dual cross-linked beads when administered at bed time may release lornoxicam when needed most for chronotherapeutics of early morning rheumatoid arthritis attacks in chronic patients.

  16. Non-invasive Estimation of Pressure Gradients in Pulsatile Flow using Ultrasound

    DEFF Research Database (Denmark)

    Olesen, Jacob Bjerring; Villagómez Hoyos, Carlos Armando; Traberg, Marie Sand;

    2014-01-01

    This paper investigates how pressure gradients in a pulsatile flow environment can be measured non-invasively using ultrasound. The presented set-up is based on vector velocity fields measured on a blood mimicking fluid moving at a peak flow rate of 1 ml/s through a constricted vessel. Fields of...... pressure gradients are calculated using the Navier-Stokes equations. Flow data are acquired to a depth of 3 cm using directional synthetic aperture flow imaging on a linear array transducer producing 1500 image frames of velocity estimates per second. Scans of a carotid bifurcation phantom with a 70......% constriction are performed using an experimental scanner. The performance of the presented estimator is evaluated by comparing its results to a numerical simulation model, which geometry is reconstructed from MRI data. The study showed pressure gradients varying from 0 kPa/m to 4.5 kPa/m with a maximum bias...

  17. Analysis of high gradient magnetic field effects on distribution of nanoparticles injected into pulsatile blood stream

    Energy Technology Data Exchange (ETDEWEB)

    Reza Habibi, Mohammad, E-mail: mohammad_habibi_4@yahoo.com [Mechanical Engineering Department, K.N.Toosi University of Technology, Tehran (Iran, Islamic Republic of); Ghassemi, Majid; Hossien Hamedi, Mohammad [Mechanical Engineering Department, K.N.Toosi University of Technology, Tehran (Iran, Islamic Republic of)

    2012-04-15

    Magnetic nanoparticles are widely used in a wide range of applications including data storage materials, pharmaceutical industries as magnetic separation tools, anti-cancer drug carriers and micro valve applications. The purpose of the current study is to investigate the effect of a non-uniform magnetic field on bio-fluid (blood) with magnetic nanoparticles. The effect of particles as well as mass fraction on flow field and volume concentration is investigated. The governing non-linear differential equations, concentration and Navier-stokes are coupled with the magnetic field. To solve these equations, a finite volume based code is developed and utilized. A real pulsatile velocity is utilized as inlet boundary condition. This velocity is extracted from an actual experimental data. Three percent nanoparticles volume concentration, as drug carrier, is steadily injected in an unsteady, pulsatile and non-Newtonian flow. A power law model is considered for the blood viscosity. The results show that during the systole section of the heartbeat when the blood velocity increases, the magnetic nanoparticles near the magnetic source are washed away. This is due to the sudden increase of the hydrodynamic force, which overcomes the magnetic force. The probability of vein blockage increases when the blood velocity reduces during the diastole time. As nanoparticles velocity injection decreases (longer injection time) the wall shear stress (especially near the injection area) decreases and the retention time of the magnetic nanoparticles in the blood flow increases. - Highlights: Black-Right-Pointing-Pointer At the systole time nanoparticles were washed away and concentration decreases. Black-Right-Pointing-Pointer Increasing injection velocity increases the shear stress on upper wall. Black-Right-Pointing-Pointer With decreasing blood velocity nanoparticles remain in flow for longer time. Black-Right-Pointing-Pointer Magnetic nanoparticles aggregation couldn't change

  18. Glucocorticoid and thyroid hormones transcriptionally regulate growth hormone gene expression.

    OpenAIRE

    Evans, R M; Birnberg, N C; Rosenfeld, M G

    1982-01-01

    In order to define the molecular mechanisms by which glucocorticoids and thyroid hormone act to regulate growth hormone gene expression, the sites at which they exert their effects on growth hormone biosynthesis were examined in vivo and in a pituitary cell line. Glucocorticoids were shown to rapidly increase accumulation of growth hormone mRNA and nuclear RNA precursors. Glucocorticoids and thyroid hormone were shown to rapidly and independently increase growth hormone gene transcription. Th...

  19. Hemostatic Disorders in Hormonally Active Pituitary Tumors.

    Science.gov (United States)

    Świątkowska-Stodulska, R; Babińska, A; Mital, A; Stodulski, D; Sworczak, K

    2015-10-01

    Endocrinopathies encompass heterogeneous diseases that can lead to hemostasis disorders at various stages over their clinical course. Normal hemostasis requires an equilibrium between the processes of coagulation and fibrinolysis, which depend on multiple activators and inhibitors. To date, the influence of various hormonal disorders on the hemostatic system has been assessed many times. The aim of this review was to analyze hemostasis abnormalities that occur in patients with hormonally active pituitary tumors: corticotropinoma, somatotropinoma, prolactinoma, gonadotropinoma and thyrotropinoma. Authors discuss studies that examined coagulation and hemostasis parameters among patients with these tumors, as well as analyze antithrombotic prophylaxis approach for endogenous hypercortisolemia subjects in particular. PMID:26285071

  20. Plant Hormone Binding Sites

    OpenAIRE

    Napier, Richard

    2004-01-01

    • Aims Receptors for plant hormones are becoming identified with increasing rapidity, although a frustrating number remain unknown. There have also been many more hormone‐binding proteins described than receptors. This Botanical Briefing summarizes what has been discovered about hormone binding sites, their discovery and descriptions, and will not dwell on receptor functions or activities except where these are relevant to understand binding.

  1. Hormone therapy for prostate cancer

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000908.htm Hormone therapy for prostate cancer To use the sharing ... helps slow the growth of prostate cancer. Male Hormones and Prostate Cancer Androgens are male sex hormones. ...

  2. 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 ...

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

    International Nuclear Information System (INIS)

    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

  4. Hormones and female sexuality

    Directory of Open Access Journals (Sweden)

    Bjelica Artur L.

    2003-01-01

    Full Text Available Introduction In contrast to animal species in which linear relationships exist between hormonal status and sexual behaviour sexuality in human population is not determined so simply by the level of sexual steroids. The article analyses female sexuality in the light of hormonal status. Administration of sexual steroids during pregnancy and sexual differentiation High doses of gestagens, especially those with high androgen activity, widely used against miscarriages may lead to tomboys, but without differences in sexual orientation. However, it has been observed that the frequency of bisexual and lesbian women is higher in women with congenital adrenogenital syndrome. Hormones sexual desire and sexuality during menstrual cycle It has been established that sexual desire, autoeroticism and sexual fantasies in women depend on androgen levels. There are a lot of reports claiming that sexual desire varies during the menstrual cycle. Hormonal contraception and sexuality Most patients using birth control pills present with decreased libido. But, there are reports that progestagens with antiandrogenic effect in contraceptive pills do not affect sexual desire. Hormonal changes in peri- and postmenopausal period and sexuality Decreased levels of estrogen and testosterone in older women are associated with decreased libido, sensitivity and erotic stimuli. Sexuality and hormone replacement therapy Hormonal therapy with estrogen is efficient in reference to genital atrophy, but not to sexual desire. Really increased libido is achieved using androgens. Also, therapy with dehydroepiandrosterone (DHEA and tibolone have positive effects on female libido. Conclusion Effect of sexual steroids on sexual sphere of women is very complex. The association between hormones and sexuality is multidimensional, as several hormones are important in regulation of sexual behaviour. Still, it should be pointed out that sexuality is in the domain of hormonal, emotional

  5. Experiment K-7-22: Growth Hormone Regulation Synthesis and Secretion in Microgravity. Part 3; Plasma Analysis Hormone Measurements

    Science.gov (United States)

    Grindeland, R. E.; Popova, I. A.; Grossman, E.; Rudolph, I.

    1994-01-01

    Plasma from space flight and tail suspended rats was analyzed for a number of constituents in order to evaluate their metabolic status and endocrine function. The data presented here cover plasma hormone measurements. Corticosterone, thyroxine, and testosterone were measured by radioimmunoassay. Prolactin and growth hormone were measured by double antibody immunoassays using hormones and antisera prepared in house. Data were evaluated by analysis of variance.

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

    International Nuclear Information System (INIS)

    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

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

    OpenAIRE

    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 utilize a computational model to compare a synchronized valveless pulsatile left ventricular assist device to 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 support of a healthy or failing native heart from a continuous flow left ventricular assist device or a synchronous, pulsatile, va...

  8. FORMULATION DESIGN AND OPTIMIZATION OF PULSATILE RELEASE TABLET OF ACEBROPHYLLINE WITH SWELLING AND ERODIABLE LAYERS FOR TREATMENT OF NOCTURNAL BRONCHIAL ASTHMA

    Directory of Open Access Journals (Sweden)

    Mohit D. Bauskar et al.

    2011-12-01

    Full Text Available Acebrophylline is a bronchodilator with mucosecrytolytic and anti-inflammatory activity. It is used to treat the bronchial asthma, and chronic obstructive pulmonary diseases. This work is based on the formulation and optimization of time dependant pulsatile release tablets of Acebrophylline having adequate mechanical strength of tablet and proper drug release of tablet. Pulsatile drug delivery system has an advantage as delivers the drug at right place, right time and right quantity. The crucial aspect in the formulation of pulsatile drug delivery system is to release the drug as pulse after a lag time has to be designed in such a way that rapid and complete drug release follows after lag time. Present work conceptualizes a specific technology, based on pulsatile principles to develop drug delivery system, intended for chronotherapy in bronchial asthma. This approach will be achieved by using a programmed delivery of acebrophylline. In this work rapid pulse to pulsatile drug delivery system can be achieved through immediate release tablet with good mechanical strength and proper disintegration. Lag time in pulsatile drug delivery system can be maintained by using coating with time responsive polymer having good mechanical strength. In this study immediate release tablet can be prepared by using two super disintegrants as Cross carmellose sodium and Cross-povidone to give rapid pulse of drug. The lag time of pulsatile drug delivery system can be maintained by coating using extended release polymer as HPMC E 50 (Methocel E 50. The programmable pulsatile release of Acebrophylline was consistent with the demands of bronchial asthma.

  9. A lumped-parameter approach for designing a novel pulsatile bioreactor for ex-vivo studies of human saphenous vein remodeling.

    Science.gov (United States)

    Piola, Marco; Soncini, Monica; Pesce, Maurizio; Fiore, Gianfranco B

    2015-08-01

    After coronary artery bypass grafting (CABG), the hemodynamic conditions experienced by the saphenous veins are similar to those experienced by coronary arteries: pulsatile pressure (80-120 mmHg), pulsatile flow (mean flow rate of 250 ml/min), and elevated shear stress (1-7 Pa). Here we present a novel pulsatile platform for studying the human saphenous vein early remodeling events after CABG. The system was designed in order to apply CABG-like pressure/flow stimulation patterns to the hosted human saphenous vein segments, i.e. a pulsatile pressure oscillating between a diastolic minimum and a systolic maximum in counter-phase with a pulsatile flow rate. Functional tests revealed good fitting of simulated and measured tracings and the ability of the pulsatile platform to mimic the complexity of the coronary hemodynamic environment with good fidelity in comparison with state-of-the-art devices. This system will enable us to study the biological response of human saphenous veins to CABG conditioning ex vivo, in currently ongoing experiments. PMID:26736821

  10. Real-time visualization of pulsatile tissue-motion in B-mode ultrasonogram for assistance in bedside diagnosis of ischemic diseases of neonatal cranium

    Science.gov (United States)

    Fukuzawa, M.; Yamada, M.; Nakamori, N.; Kitsunezuka, Y.

    2008-03-01

    By developing a real-time visualization system, pulsatile tissue-motion caused by artery pulsation of blood flow has been visualized continuously from a video stream of ultrasonogram in brightness mode. The system concurrently executes the three processes: (1) capturing an input B-mode video stream (640×480 pixels/frame, 30 fps) into a ring buffer of 256 frames, (2) detecting intensity and phase of pulsatile tissue-motion at each pixel from a heartbeat-frequency component in Fourier transform of a series of pixel value through the latest 64 frames as a function of time, and (3) generating an output video-stream of pulsatile-phase image, in which the motion phase is superimposed as color gradation on an input video-stream when the motion intensity exceeds a proper threshold. By optimizing the visualization software with the streaming SIMD extensions, the pulsatile-phase image has been continuously updated at more than 10 fps, which was enough to observe pulsatile tissue-motion in real time. Compared to the retrospective technique, the real-time visualization had clear advantages not only in enabling bedside observation and quick snapshot of pulsatile tissue-motion but also in giving useful feedback to probe handling for avoiding unwanted motion-artifacts, which may strongly assist pediatricians in bedside diagnosis of ischemic diseases.

  11. Pulsatile blood flow in large arteries:comparative study of Burton’s and McDonald’s models

    Institute of Scientific and Technical Information of China (English)

    K.GAYATHRI; K.SHAILENDHRA

    2014-01-01

    To get a clear picture of the pulsatile nature of blood flow and its role in the pathogenesis of atherosclerosis, a comparative study of blood flow in large arteries is carried out using the two widely used models, McDonald’s and Burton’s models, for the pressure gradient. For both models, the blood velocity in the lumen is obtained analytically. Elaborate investigations on the wall shear stress (WSS) and oscillatory shear index (OSI) are carried out. The results are in good agreement with the available data in the literature. The superiority of McDonald’s model in capturing the pulsatile nature of blood flow, especially the OSI, is highlighted. The present investigation supports the hypothesis that not only WSS but also OSI are the essential features determining the pathogenesis of atherosclerosis. Finally, by reviewing the limitations of the present investigation, the possibility of improvement is explored.

  12. MR angiography of stenosis and aneurysm models in the pulsatile flow: variation with imaging parameters and concentration of contrast media

    International Nuclear Information System (INIS)

    The image quality of magnetic resonance angiography (MRA) varies according to the imaging techniques applied and the parameters affected by blood flow patterns, as well as by the shape of the blood vessels. This study was designed to assess the influence on signal intensity and its distribution of the geometry of these vessels, the imaging parameters, and the concentration of contrast media in MRA of stenosis and aneurysm models. MRA was performed in stenosis and aneurysm models made of glass tubes, using pulsatile flow with viscosity and flow profile similar to those of blood. Slice and maximum intensity projection (MIP) images were obtained using various imaging techniques and parameters;there was variation in repetition time, flip angle, imaging planes, and concentrations of contrast media. On slice images of three-dimensional (3D) time-of-flight (TOF) techniques, flow signal intensity was measured at five locations in the models, and contrast ratio was calculated as the difference between flow signal intensity (SI) and background signal intensity (SIb) divided by background signal intensity or (SI-SIb)/SIb. MIP images obtained by various techniques and using various parameters were also analyzed, with emphasis in the stenosis model on demonstrated degree of stenosis, severity of signal void and image distortion, and in the aneurysm model, on degree of visualization, distortion of contour and distribution of signals. In 3D TOF, the shortest TR (36 msec) and the largest FA (50 deg ) resulted in the highest contrast ratio, but larger flip angles did not effectively demonstrate the demonstration of the peripheral part of the aneurysm. Loss of signal was most prominent in images of the stenosis model obtained with parallel or oblique planes to the flow direction. The two-dimensional TOF technique also caused signal void in stenosis, but precisely demonstrated the aneurysm, with dense opacification of the peripheral part. The phase contrast technique showed some

  13. Osteoblasts respond to pulsatile fluid flow with short-term increases in PGE(2) but no change in mineralization

    Science.gov (United States)

    Nauman, E. A.; Satcher, R. L.; Keaveny, T. M.; Halloran, B. P.; Bikle, D. D.

    2001-01-01

    Although there is no consensus as to the precise nature of the mechanostimulatory signals imparted to the bone cells during remodeling, it has been postulated that deformation-induced fluid flow plays a role in the mechanotransduction pathway. In vitro, osteoblasts respond to fluid shear stress with an increase in PGE(2) production; however, the long-term effects of fluid shear stress on cell proliferation and differentiation have not been examined. The goal of this study was to apply continuous pulsatile fluid shear stresses to osteoblasts and determine whether the initial production of PGE(2) is associated with long-term biochemical changes. The acute response of bone cells to a pulsatile fluid shear stress (0.6 +/- 0.5 Pa, 3.0 Hz) was characterized by a transient fourfold increase in PGE(2) production. After 7 days of static culture (0 dyn/cm(2)) or low (0.06 +/- 0.05 Pa, 0.3 Hz) or high (0.6 +/- 0.5 Pa, 3.0 Hz) levels of pulsatile fluid shear stress, the bone cells responded with an 83% average increase in cell number, but no statistical difference (P > 0.53) between the groups was observed. Alkaline phosphatase activity per cell decreased in the static cultures but not in the low- or high-flow groups. Mineralization was also unaffected by the different levels of applied shear stress. Our results indicate that short-term changes in PGE(2) levels caused by pulsatile fluid flow are not associated with long-term changes in proliferation or mineralization of bone cells.

  14. Glucose uptake and pulsatile insulin infusion: euglycaemic clamp and (3-/sup 3/H)glucose studies in healthy subjects

    Energy Technology Data Exchange (ETDEWEB)

    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 rather 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 center dot min or in identical amounts in pulses of 1/sup 1///sub 2/ to 2/sup 1///sub 4/ min followed by intervals of 10/sup 1///sub 2/ to 9/sup 3///sub 4/ min. Average serum insulin levels were similar during the two infusion protocols, but pulsatile administration induced oscillations ranging between 15 and 62 ..mu..U/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 center dot min, P < 0.01, and 330-354 min: 8.9 +- 0.5 vs 7.4 +- 0.9 ml/kg center dotmin, P<0.05). The superior efficacy of pulsatile insulin delivery on glucose uptake was not consistently found until after 210 min of insulin administration. In both infusion protocols, endogenous glucose production as estimated by the (3-/sup 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.

  15. Particle Image Velocimetry Study of Pulsatile Flow in Bi-leaflet Mechanical Heart Valves with Image Compensation Method

    OpenAIRE

    Shi, Yubing; Yeo, Tony Joon Hock; Zhao, Yong; Hwang, Ned H. C.

    2006-01-01

    Particle Image Velocimetry (PIV) is an important technique in studying blood flow in heart valves. Previous PIV studies of flow around prosthetic heart valves had different research concentrations, and thus never provided the physical flow field pictures in a complete heart cycle, which compromised their pertinence for a better understanding of the valvular mechanism. In this study, a digital PIV (DPIV) investigation was carried out with improved accuracy, to analyse the pulsatile flow field ...

  16. The Heritability of Glaucoma-Related Traits Corneal Hysteresis, Central Corneal Thickness, Intraocular Pressure, and Choroidal Blood Flow Pulsatility

    OpenAIRE

    Freeman, Ellen E.; Roy-Gagnon, Marie-Hélène; Descovich, Denise; Massé, Hugues; Mark R. Lesk

    2013-01-01

    Purpose The purpose of this work was to investigate the heritability of potential glaucoma endophenotypes. We estimated for the first time the heritability of the pulsatility of choroidal blood flow. We also sought to confirm the heritability of corneal hysteresis, central corneal thickness, and 3 ways of measuring intraocular pressure. Methods Measurements were performed on 96 first-degree relatives recruited from Maisonneuve-Rosemont Hospital in Montreal. Corneal hysteresis was determined u...

  17. The heritability of glaucoma-related traits corneal hysteresis, central corneal thickness, intraocular pressure, and choroidal blood flow pulsatility.

    Directory of Open Access Journals (Sweden)

    Ellen E Freeman

    Full Text Available PURPOSE: The purpose of this work was to investigate the heritability of potential glaucoma endophenotypes. We estimated for the first time the heritability of the pulsatility of choroidal blood flow. We also sought to confirm the heritability of corneal hysteresis, central corneal thickness, and 3 ways of measuring intraocular pressure. METHODS: Measurements were performed on 96 first-degree relatives recruited from Maisonneuve-Rosemont Hospital in Montreal. Corneal hysteresis was determined using the Reichert Ocular Response Analyser. Central corneal thickness was measured with an ultrasound pachymeter. Three measures of intraocular pressure were obtained: Goldmann-correlated and corneal compensated intraocular pressure using the Ocular Response Analyser, and Pascal intraocular pressure using the Pascal Dynamic Contour Tonometer. The pulsatility of choroidal blood velocity and flow were measured in the sub-foveolar choroid using single-point laser Doppler flowmetry (Oculix. We estimated heritability using maximum-likelihood variance components methods implemented in the SOLAR software. RESULTS: No significant heritability was detected for the pulsatility of choroidal blood flow or velocity. The Goldman-correlated, corneal compensated, and Pascal measures of intraocular pressure measures were all significantly heritable at 0.94, 0.79, and 0.53 after age and sex adjustment (p = 0.0003, p = 0.0023, p = 0.0239. Central corneal thickness was significantly heritable at 0.68 (p = 0.0078. Corneal hysteresis was highly heritable but the estimate was at the upper boundary of 1.00 preventing us from giving a precise estimate. CONCLUSION: Corneal hysteresis, central corneal thickness, and intraocular pressure are all heritable and may be suitable as glaucoma endophenotypes. The pulsatility of choroidal blood flow and blood velocity were not significantly heritable in this sample.

  18. How to use and interpret hormone ratios.

    Science.gov (United States)

    Sollberger, Silja; Ehlert, Ulrike

    2016-01-01

    Hormone ratios have become increasingly popular throughout the neuroendocrine literature since they offer a straightforward way to simultaneously analyze the effects of two interdependent hormones. However, the analysis of ratios is associated with statistical and interpretational concerns which have not been sufficiently considered in the context of endocrine research. The aim of this article, therefore, is to demonstrate and discuss these issues, and to suggest suitable ways to address them. In a first step, we use exemplary testosterone and cortisol data to illustrate that one major concern of ratios lies in their distribution and inherent asymmetry. As a consequence, results of parametric statistical analyses are affected by the ultimately arbitrary decision of which way around the ratio is computed (i.e., A/B or B/A). We suggest the use of non-parametric methods as well as the log-transformation of hormone ratios as appropriate methods to deal with these statistical problems. However, in a second step, we also discuss the complicated interpretation of ratios, and propose moderation analysis as an alternative and oftentimes more insightful approach to ratio analysis. In conclusion, we suggest that researchers carefully consider which statistical approach is best suited to investigate reciprocal hormone effects. With regard to the hormone ratio method, further research is needed to specify what exactly this index reflects on the biological level and in which cases it is a meaningful variable to analyze. PMID:26521052

  19. Growth hormone deficiency - children

    Science.gov (United States)

    ... be done include: Insulin-like growth factor 1 (IGF-1) and insulin-like growth factor binding protein ... themselves the shot. Treatment with growth hormone is long-term, often lasting for several years. During this ...

  20. Growth hormone stimulation test

    Science.gov (United States)

    The growth hormone (GH) stimulation test measures the ability of the body to produce GH. ... killing medicine (antiseptic). The first sample is drawn early in the morning. Medicine is given through the ...

  1. LH (Luteinizing Hormone) Test

    Science.gov (United States)

    ... reason for the delayed puberty. Some of the causes for delayed puberty can include: Failure of the ovaries or testicles Hormone deficiency Turner syndrome Klinefelter syndrome Chronic infections Cancer Eating disorder (anorexia nervosa) ^ Back to top Is there anything ...

  2. Pulsatile dynamic stiffness of cartilage-like materials and use of agarose gels to validate mechanical methods and models.

    Science.gov (United States)

    Scandiucci de Freitas, P; Wirz, D; Stolz, M; Göpfert, B; Friederich, N-F; Daniels, A U

    2006-08-01

    Stiffness is a fundamental indicator of the functional state of articular cartilage. Reported test modes include compressive incremental strain to determine the equilibrium modulus, and sinusoidal strain to determine the dynamic modulus and stress/strain loss angle. Here, initial development is described for a method recognizing that gait is pulsatile. Agarose gels have been used by others for validation or comparison of mechanical test methods and models for cartilage and proteoglycan aggregate. Accordingly, gels ranging from 0.5 to 20% agarose were prepared. Pulsatile stiffness in both indentation and unconfined compression were closely reproducible. Stiffness as a function of agarose concentration rose exponentially, as found using other methods. Indentation stiffness was higher than for unconfined compression and ranged from approximately 2.0 kPa for 0.5% gel to approximately 3,800 kPa for 20% gel. Pulsatile dynamic stiffness appears to be a useful method, although further development is needed. Agarose gel stiffness values obtained by other methods were reviewed for comparison. Unfortunately, reported values for a given agarose concentration ranged widely (e.g. fourfold) even when test methods were similar. Causes appear to include differences in molecular weight and gel preparation time-temperature regimens. Also, agarose is hygroscopic, leading to unintended variations in gel composition. Agarose gels are problematic materials for validation or comparison of cartilage mechanical test methods and models. PMID:16470817

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

    International Nuclear Information System (INIS)

    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 11/2 to 21/4 min followed by intervals of 101/2 to 93/4 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 3H]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)

  4. Bioidentical Hormone Therapy

    OpenAIRE

    Files, Julia A.; Ko, Marcia G.; Pruthi, Sandhya

    2011-01-01

    The change in hormonal milieu associated with perimenopause and menopause can lead to a variety of symptoms that can affect a woman's quality of life. Postmenopausal hormone therapy (HT) is an effective, well-tolerated treatment for these symptoms. However, combined HT consisting of conjugated equine estrogen and medroxyprogesterone acetate has been associated with an increased number of health risks when compared with conjugated equine estrogen alone or placebo. As a result, some women are t...

  5. Protein Hormones and Immunity‡

    Science.gov (United States)

    Kelley, Keith W.; Weigent, Douglas A.; Kooijman, Ron

    2007-01-01

    A number of observations and discoveries over the past 20 years support the concept of important physiological interactions between the endocrine and immune systems. The best known pathway for transmission of information from the immune system to the neuroendocrine system is humoral in the form of cytokines, although neural transmission via the afferent vagus is well documented also. In the other direction, efferent signals from the nervous system to the immune system are conveyed by both the neuroendocrine and autonomic nervous systems. Communication is possible because the nervous and immune systems share a common biochemical language involving shared ligands and receptors, including neurotransmitters, neuropeptides, growth factors, neuroendocrine hormones and cytokines. This means that the brain functions as an immune-regulating organ participating in immune responses. A great deal of evidence has accumulated and confirmed that hormones secreted by the neuroendocrine system play an important role in communication and regulation of the cells of the immune system. Among protein hormones, this has been most clearly documented for prolactin (PRL), growth hormone (GH), and insulin-like growth factor-1 (IGF-I), but significant influences on immunity by thyroid stimulating hormone (TSH) have also been demonstrated. Here we review evidence obtained during the past 20 years to clearly demonstrate that neuroendocrine protein hormones influence immunity and that immune processes affect the neuroendocrine system. New findings highlight a previously undiscovered route of communication between the immune and endocrine systems that is now known to occur at the cellular level. This communication system is activated when inflammatory processes induced by proinflammatory cytokines antagonize the function of a variety of hormones, which then causes endocrine resistance in both the periphery and brain. Homeostasis during inflammation is achieved by a balance between cytokines and

  6. Gastrointestinal hormones regulating appetite

    OpenAIRE

    Chaudhri, Owais; Small, Caroline; Bloom, Steve

    2006-01-01

    The role of gastrointestinal hormones in the regulation of appetite is reviewed. The gastrointestinal tract is the largest endocrine organ in the body. Gut hormones function to optimize the process of digestion and absorption of nutrients by the gut. In this capacity, their local effects on gastrointestinal motility and secretion have been well characterized. By altering the rate at which nutrients are delivered to compartments of the alimentary canal, the control of food intake arguably cons...

  7. Hormones and female sexuality

    OpenAIRE

    Bjelica Artur L.; Kapamadžija Aleksandra; Maticki-Sekulić Milana

    2003-01-01

    Introduction In contrast to animal species in which linear relationships exist between hormonal status and sexual behaviour sexuality in human population is not determined so simply by the level of sexual steroids. The article analyses female sexuality in the light of hormonal status. Administration of sexual steroids during pregnancy and sexual differentiation High doses of gestagens, especially those with high androgen activity, widely used against miscarriages may lead to tomboys, but with...

  8. Body segments and growth hormone.

    OpenAIRE

    Bundak, R; Hindmarsh, P. C.; Brook, C G

    1988-01-01

    The effects of human growth hormone treatment for five years on sitting height and subischial leg length of 35 prepubertal children with isolated growth hormone deficiency were investigated. Body segments reacted equally to treatment with human growth hormone; this is important when comparing the effect of growth hormone on the growth of children with skeletal dysplasias or after spinal irradiation.

  9. Kinetics of thyroid hormones

    International Nuclear Information System (INIS)

    Kinetics of thyroid hormones were outlined, and recent progress in metabolism of these hormones was also described. Recently, not only T4 and T3 but also rT3, 3,3'-T2, 3',5'-T2, and 3,5-T2 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 T3 and T2 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 T4 metabolism, T3 was formed by 5'-monodeiodination of T4, and rT3 was formed by 5-monodeiodination of T4. As metabolic pathways of T3 and rT3, conversion of them to 3,3'-T2 or to 3',5'-T2 and 3,5-T2 was supposed. This subject will be an interesting research theme in future. (Tsunoda, M.)

  10. Hormonal control of inflammatory responses

    OpenAIRE

    Garcia-Leme, J.; Farsky, Sandra P

    1993-01-01

    Almost any stage of inflammatory and immunological responses is affected by hormone actions. This provides the basis for the suggestion that hormones act as modulators of the host reaction against trauma and infection. Specific hormone receptors are detected in the reactive structures in inflamed areas and binding of hormone molecules to such receptors results in the generation of signals that influence cell functions relevant for the development of inflammatory responses. Diversity of hormon...

  11. Generating a Pulsatile Pulmonary Flow after Fontan Operation by Means of Computational Fluid Dynamics (CFD)

    Science.gov (United States)

    Ghoreyshi, Mostafa

    2011-03-01

    This study considers blood flow in total cavopulmonary connection (TCPC) morphology, which is created in Fontan surgical procedure in patients with single ventricle heart disease. Ordinary process of TCPC operation reduces pulmonary blood flow pulsatility; because of right ventricle being bypassed. This phenomenon causes a lot of side effects for patients. A cardiac surgeon has suggested that keeping main pulmonary artery (MPA) partially open, would increase pulmonary flow pulsations. MPA gets closed in ordinary TCPC operation. The purpose of current study is to verify the effects of keeping MPA partially open on pulmonary flow pulsations, by means of computational fluid dynamics (CFD). 3D geometry is reconstructed from CT Angiography (CTA) scan of a patient who has undergone an ordinary TCPC procedure. The stenosed MPA or pulmonary stenosis (PS) is virtually added to the original geometry. Flow field is studied in six different models in which average antegrade flow (AF) -coming through PS- increases gradually. Results show that adding AF increases flow pulsations in both pulmonary arteries. Moreover, power loss increases with respect to average AF. We conclude that adding AF is an impressive way to increase pulsations of pulmonary flow, but energy losses should be considered too.

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

    Science.gov (United States)

    Shit, G. C.; Majee, Sreeparna

    2015-08-01

    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.

  13. Computational Fluid Dynamics Analysis of Pulsatile Blood Flow Behavior in Modelled Stenosed Vessels with Different Severities

    Directory of Open Access Journals (Sweden)

    Mohsen Mehrabi

    2012-01-01

    Full Text Available This study focuses on the behavior of blood flow in the stenosed vessels. Blood is modelled as an incompressible non-Newtonian fluid which is based on the power law viscosity model. A numerical technique based on the finite difference method is developed to simulate the blood flow taking into account the transient periodic behaviour of the blood flow in cardiac cycles. Also, pulsatile blood flow in the stenosed vessel is based on the Womersley model, and fluid flow in the lumen region is governed by the continuity equation and the Navier-Stokes equations. In this study, the stenosis shape is cosine by using Tu and Devil model. Comparing the results obtained from three stenosed vessels with 30%, 50%, and 75% area severity, we find that higher percent-area severity of stenosis leads to higher extrapressure jumps and higher blood speeds around the stenosis site. Also, we observe that the size of the stenosis in stenosed vessels does influence the blood flow. A little change on the cross-sectional value makes vast change on the blood flow rate. This simulation helps the people working in the field of physiological fluid dynamics as well as the medical practitioners.

  14. Dynamic time warping and machine learning for signal quality assessment of pulsatile signals

    International Nuclear Information System (INIS)

    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)

  15. 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.

  16. Numerical analysis of bypass model geometrical parameters influence on pulsatile blood flow

    Directory of Open Access Journals (Sweden)

    Jonášová A.

    2011-06-01

    Full Text Available The present study is focused on the analysis of pulsatile blood flow in complete idealized 3D bypass models in dependence on three main geometrical parameters (stenosis degree, junction angle and diameter ratio. Assuming the blood to be an incompressible Newtonian fluid, the non-linear system of Navier-Stokes equations is integrated in time by a fully implicit second-order accurate fractional-step method. The space discretization is performed with the help of the cell-centred finite volume method formulated for unstructured tetrahedral grids. In order to model a realistic coronary blood flow, a time-dependent flow rate taken from corresponding literature is considered. For the analysis of obtained numerical results, special emphasis is placed on their comparison in the form of velocity isolines at several selected cross-sections during systolic and diastolic phases. The remainder of this paper is devoted to discussion of walls shear stress distribution and its oscillatory character described by the oscillatory shear index with regard to areas prone to development of intimal hyperplasia or to thrombus formation.

  17. 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 press-coated tablets of 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). PMID:25721985

  18. FORMULATION AND EVALUATION OF METOPROLOL SUCCINATE PULSATILE DRUG DELIVERY SYSTEM FOR CHRONO BIOLOGICAL DISORDER: ANTI HYPERTENSION

    Directory of Open Access Journals (Sweden)

    A. Anil Kumar et al

    2012-10-01

    Full Text Available The objective of the present study was to develop and evaluate an oral pulsatile drug delivery system to mimic the circadian rhythm of the disease by releasing the drug with a distinct predetermined log time of 5 hrs (+ 0.25 hrs. The basic design of the pulse in cap formulation of metoprolol provides time controlled release to treat the nocturnal symptoms of hypertension and angina pectoris. The pulsincap formulation of Metoprolol provides time controlled release to treat the nocturnal symptoms of hypertension and angina pectoris. If the formulation is administered in the night at 10.00 pm symptoms that are experienced in early morning hours could be avoided. In the present study, polymer such as Guargum selected for colon targeting of Metoprolol succinate. Metoprolol succinate granules were prepared using these polymers to prolong and target to the colon. Granules were prepared by wet granulation technique using different polymers in different ratios. These granules filled into the formaldehyde treated capsules and plugged with optimized HPMC plug, to maintain the 5hr lag time. Finally capsules are enteric coated with enteric coating polymers and conducted dissolution studies with different pH mediums.

  19. A thrombus susceptibility comparison of two pulsatile Penn State 50 cc left ventricular assist device designs.

    Science.gov (United States)

    Navitsky, Michael A; Deutsch, Steven; Manning, Keefe B

    2013-01-01

    Left ventricular assist devices (LVADs) have proven successful as bridge to transplant devices for patients awaiting donor organs. While survival rates continue to increase, destination therapy remains hindered by thrombus formation within the device. Research has shown that thrombosis is correlated to the fluid dynamics within the device and may be a result of sustained shear rates below 500 s(-1) on the polyurethane blood sac used in the Penn State pulsatile LVAD. Particle image velocimetry is used to compare flow within two 50 cc LVAD designs to assess fluid patterns and quantify wall shear rates in regions known from in vivo studies to be susceptible to thrombus formation. The two designs differ in their front face geometry. The V-1 model has an outward-facing "dome" whereas the face of the V-2 model is flat. A thrombus susceptibility metric, which uses measured wall shear rates and exposure times, was applied to objectively compare pump designs over the entire cardiac cycle. For each design, there are regions where wall shear rates remained below 500 s(-1) for the entire cardiac cycle resulting in high thrombus susceptibility potential. Results of this study indicate that the V-2 device had an overall lower propensity for thrombus formation in the current region of interest. PMID:22825798

  20. The usefulness of pulsatile flow detection in measuring resistive index in renal doppler US

    International Nuclear Information System (INIS)

    To assess the usefulness of pulsatile flow detection (PFD), a newly developed function of color Doppler US, in measuring resistive index (RI) in renal Doppler US and to compare it with conventional color Doppler (CCD). Fifty-six kidneys in 31 patients were randomly selected and divided into two groups. In group A, RI was measured first with the aid of CCD, and then with PFD. In group B, data were obtained in the reverse order. The time required for each RI measurement was recorded in seconds. The quality of the Doppler spectral waveform was subjectively graded as 0, 1, or 2 and examination time and waveform quality were compared between PFD and CCD. The time required to measure RI with PFD (PFD time) was less than with CCD (CCD time) (mean 42.7 secs vs. mean 70.3 secs; p = 0.031). There was no significant difference in PFD time between group A and B, but CCD time was shorter in group B (70.3 secs vs. 24.6 secs; p = 0.0004). Spectral waveform quality was not significantly different between PFD and CCD. The time required to measure RI in kidneys can be shortened with the aid of the PFD function in color Doppler US without affecting the quality of the examination

  1. Superficial temporal artery pseudoaneurysm presenting as a growing, pulsatile, and tender mass

    Science.gov (United States)

    Seferi, Arsen; Alimehmeti, Ridvan; Pajaj, Ermira; Vyshka, Gentian

    2016-01-01

    Background: Superficial temporal artery (STA) pseudoaneurysms have been reported in the literature since the mid of seventeenth century from Bartholin, however, there is an increasing number of cases, suggesting a diversity of etiological factors. Among these, traumatic events, even of an iatrogenic nature, have been identified as causative factors for nonspontaneous STA pseudoaneurysms. Regional pain and tenderness, troublesome pulsations of the mass, cosmetic concerns as well as the risk of bleeding warrant a thorough evaluation and a definite interventional approach to the condition. Case Description: A 21-year-old Caucasian male searched medical advice for a growing, tender, and pulsatile mass on his right temple, with isolated and short episodes of lancinating sensations, after sustaining a blunt trauma following a hit with a stick half a year before the admission. Enhanced cranial computed tomography and angiography confirmed the diagnosis of an STA pseudoaneurysm. A direct percutaneous aspiration, as well as ultrasonography, was performed prior to the neurosurgical intervention, with the complete removal of the mass. Conclusions: STA pseudoaneurysms require a careful evaluation and a conclusive approach in order to avoid the risk of a growing mass and other nonremote complications such as bone erosions and bleeding. Different treatment options are available, including endovascular obliteration and embolization, however, surgical removal after ligation of the afferent and efferent segments of the vessel seem to be highly effective.

  2. 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.

  3. Impedance cardiography: Pulsatile blood flow and the biophysical and electrodynamic basis for the stroke volume equations

    Directory of Open Access Journals (Sweden)

    Donald P Bernstein

    2010-01-01

    Full Text Available Impedance cardiography (ICG is a branch of bioimpedance pimarily concerned with the determination of left ventricular stroke volume (SV. As implemented, using the transthoracic approach, the technique involves applying a current field longitudinally across a segment of thorax by means of a constant magnitude, high frequency, low amplitude alternating current (AC. By Ohm's Law, the voltage difference measured within the current field is proportional to the electrical impedance Z (Ω. Without ventilatory or cardiac activity, Z is known as the transthoracic, static base impedance Z0. Upon ventricular ejection, a characteristic time dependent cardiac-synchronous pulsatile impedance change is obtained, ΔZ(t, which, when placed electrically in parallel with Z0, constitutes the time-variable total transthoracic impedance Z(t. ΔZ(t represents a dual-element composite waveform, which comprises both the radially-oriented volumetric expansion of and axially-directed forward blood flow within both great thoracic arteries. In its majority, however, ΔZ(t is known to primarily emanate from the ascending aorta. Conceptually, commonly implemented methods assume a volumetric origin for the peak systolic upslope of ΔZ(t, (i.e. dZ/dtmax, with the presumed units of Ω·s-1. A recently introduced method assumes the rapid ejection of forward flowing blood in earliest systole causes significant changes in the velocity-induced blood resistivity variation (Δρb(t, Ωcm·s-1, and it is the peak rate of change of the blood resistivity variation dρb(t/dtmax (Ωcm·s-2 that is the origin of dZ/dtmax. As a consequence of dZ/dtmax peaking in the time domain of peak aortic blood acceleration, dv/dtmax (cm·s-2, it is suggested that dZ/dtmax is an ohmic mean acceleration analog (Ω·s-2 and not a mean flow or velocity surrogate as generally assumed. As conceptualized, the normalized value, dZ/dtmax/Z0, is a dimensionless ohmic mean acceleration equivalent (s-2

  4. Pulsatility index in carotid arteries is increased in levothyroxine-treated Hashimoto disease.

    Science.gov (United States)

    Owecki, M; Sawicka-Gutaj, N; Owecki, M K; Ambrosius, W; Dorszewska, J; Oczkowska, A; Michalak, M; Fischbach, J; Kozubski, W; Ruchała, M

    2015-07-01

    The aim of this case-control study was to evaluate carotid hemodynamic variables and traditional cardiovascular risk factors in women with Hashimoto thyroiditis (HT). The study group consisted of 31 females with HT on levothyroxine (L-T4) and 26 euthyroid women with HT without L-T4 matched for age and body mass index (BMI) as controls. Carotid intima-media thickness (CIMT), carotid extra-media thickness (CEMT), and pulsatility indexes in common carotid artery (PI CCA) and in internal carotid artery (PI ICA) were measured. BMI, waist circumference, lipid profile, fasting glucose and insulin levels, and parameters of thyroid function [TSH, free thyroxine (FT4) and antithyroperoxidase antibodies (TPOAbs)] were assessed. The study and the control groups did not differ in age, BMI, waist circumference, lipid profile, fasting glucose, and insulin levels. Results are expressed as median (IQR). Treated HT group had higher FT4 levels than nontreated [17.13 (5.11) pmol/l vs. 14.7 (2.27) pmol/l; p=0.0011] and similar TSH [1.64 (2.08) IU/ml vs. 2.07 (3.14) IU/ml; p=0.5915]. PI CCA and PI ICA were higher in the study group than in controls (p=0.0224 and p=0.0477, respectively). The difference remained statistically significant for PI ICA and PI CCA after adjustment for other variables (coefficient=0.09487; standard error=0.04438; p=0.037 and coefficient=0.1786; standard error=0.0870; p=0.0449, respectively). CIMT and CEMT were similar in both groups (p=0.8746 and p=0.0712, respectively). Women with HT on L-T4 replacement therapy have increased PI in common and internal carotid arteries than nontreated euthyroid HT patients. Therefore, it seems that hypothyroidism, but not autoimmune thyroiditis per se, influences arterial stiffness. PMID:25671800

  5. Pulsatility Index in Aortic Coarctation: A Possible Way to Evaluate Factors Affecting Stenting Outcome

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Keramati

    2012-03-01

    Full Text Available Background: The pulsatility index (PI shows continuous blood flow to the end organs and is a significant factor believed to decrease in aortic coarctation. Correction of this factor is of great importance in the treatment of stenotic lesions of the aorta. However, there are minimal data regarding the trend of changes in the PI after stent implantation. Furthermore, the association between the PI and other echocardiographic indices in patients undergoing stent implantation is unclear. This study was designed to evaluate changes in the PI following stenting and its correlation with other echocardiographic indices. Methods: Twenty-three patients with a diagnosis of aortic coarctation consecutively underwent two-dimensional and Doppler echocardiographic imaging modalities twice (before and after stenting. The patients were divided into two groups based on the percentage of increase in the PI after stenting ( < 50% or ≥ 50%. The relation between the post-stenting PI and the baseline echocardiographic indices was assessed. Results: The PI was increased from 0.89 (SD = 0.30 to 1.75 (SD = 0.51 after stenting (p value < 0.001. Baseline diastolic/systolic velocity (D/S velocity ratio of the abdominal aorta (p value = 0.013, mean velocity (p value = 0.033, and peak gradient of the descending aorta (p value = 0.033 were significantly higher in the patients with ≥ 50% increase in the PI after stenting. Conclusion: Our findings showed that elevation in the PI after stenting was a predictable criterion in patients with aortic coarctation: it was predicted by some baseline clinical and echocardiographic indices. Baseline D/S ratio velocity of the abdominal aorta, mean velocity and peak gradient of the descending aorta, and baseline systolic blood pressure were the statistically significant indices to predict ≥ 50% increase in the PI in our patients.

  6. Development of press-coated, floating-pulsatile drug delivery of lisinopril.

    Science.gov (United States)

    Jagdale, Swati C; Suryawanshi, Vishnu M; Pandya, Sudhir V; Kuchekar, Bhanudas S; Chabukswar, Aniruddha R

    2014-06-01

    Lisinopril is an angiotensin-converting enzyme (ACE) inhibitor, primarily used for the treatment of hypertension, congestive heart failure, and heart attack. It belongs to BCS class III having a half-life of 12 hrs and 25% bioavailability. The purpose of the present work was to develop a press-coated, floating-pulsatile drug delivery system. The core tablet was formulated using the super-disintegrants crosprovidone and croscarmellose sodium. A press-coated tablet (barrier layer) contained the polymer carrageenan, xanthan gum, HPMC K4M, and HPMC K15M. The buoyant layer was optimized with HPMC K100M, sodium bicarbonate, and citric acid. The tablets were evaluated for physical characteristics, floating lag time, swelling index, FTIR, DSC, and in vitro and in vivo behavior. The 5% superdisintgrant showed good results. The FTIR and DSC study predicted no chemical interactions between the drug and excipients. The formulation containing xanthan gum showed drug retaining abilities, but failed to float. The tablet containing HPMC K15M showed a high swelling index. The lag time for the tablet coated with 200 mg carrageenan was 3±0.1 hrs with 99.99±1.5% drug release; with 140 mg HPMC K4M, the lag time was 3±0.1 hrs with 99.71±1.2% drug release; and with 120 mg HPMC K15M, the lag time was 3±0.2 hrs with 99.98±1.7% drug release. The release mechanism of the tablet followed the Korsmeyer-Peppas equation and a first-order release pattern. Floating and lag time behavior have shown good in vitro and in vivo correlations. PMID:24959410

  7. Fetal umbilical artery Doppler pulsatility index and childhood neurocognitive outcome at 12 years

    Science.gov (United States)

    Mone, Fionnuala; McConnell, Barbara; Thompson, Andrew; Segurado, Ricardo; Hepper, Peter; Stewart, Moira C; Dornan, James C; Ong, Stephen; McAuliffe, Fionnuala M; Shields, Michael D

    2016-01-01

    Objective To determine whether an elevated fetal umbilical artery Doppler (UAD) pulsatility index (PI) at 28 weeks’ gestation, in the absence of fetal growth restriction (FGR) and prematurity, is associated with adverse neurocognitive outcome in children aged 12 years. Methods Prospective cohort study, comparing children with a normal fetal UAD PI (<90th centile) (n=110) and those with an elevated PI (≥90th centile) (n=40). UAD was performed at 28, 32 and 34 weeks gestation. At 12 years of age, all children were assessed under standardised conditions at Queen's University, Belfast, UK to determine cognitive and behavioural outcomes using the British Ability Score-II and Achenbach Child Behavioural Checklist Parent Rated Version under standardised conditions. Regression analysis was performed, controlling for confounders such as gender, socioeconomic status and age at assessment. Results The mean age of follow-up was 12.4 years (±0.5 SD) with 44% of children male (n=63). When UAD was assessed at 28 weeks, the elevated fetal UAD group had lower scores in cognitive assessments of information processing and memory. Parameters included (1) recall of objects immediate verbal (p=0.002), (2) delayed verbal (p=0.008) and (3) recall of objects immediate spatial (p=0.0016). There were no significant differences between the Doppler groups at 32 or 34 weeks' gestation. Conclusions An elevated UAD PI at 28 weeks' gestation in the absence of FGR or prematurity is associated with lower scores of declarative memory in children aged 12 years. A potential explanation for this is an element of placental insufficiency in the presence of the appropriately grown fetus, which affects the development of the fetal hippocampus and information processing and memory long-term. These findings, however, had no impact on overall academic ability, mental processing and reasoning or overall behavioural function. PMID:27311899

  8. Development of a miniature motor-driven pulsatile LVAD driven by a fuzzy controller.

    Science.gov (United States)

    Okamoto, Eiji; Makino, Tsutomu; Tanaka, Shuji; Yasuda, Takahiko; Akasaka, Yuta; Tani, Makiko; Inoue, Yusuke; Mitoh, Ayumu; Mitamura, Yoshinori

    2007-01-01

    We have been developing a small, lightweight motor-driven pulsatile left ventricular assist device (LVAD) with a ball screw. The motor-driven LVAD consists of a brushless DC motor and a ball screw. The attractive magnetic force between Nd-Fe-B magnets (with a diameter of 5 mm and a thickness of 1.5 mm) mounted in holes in a silicone rubber sheet (thickness 2 mm) and an iron plate adhered onto the a diaphragm of the blood pump can provide optimum active blood filling during the pump filling phase. The LVAD has a stroke volume of 55 ml and an overall volume of 285 ml; it weighs 360 g. The controller mainly consists of a fuzzy logic position and velocity controller to apply doctors' and engineers' knowledge to control the LVAD. Each unit of the controller consists of a functionally independent program module for easy improvement of the controller's performance. The LVAD was evaluated in in vitro experiments using a mock circulation. A maximum pump outflow of 5.1 l/min was obtained at a drive rate of 95 bpm against an afterload of 95 mmHg, and active filling using the attractive magnetic force provided a pump output of 3.6 l/min at a drive rate of 75 bpm under a preload of 0 mmHg. The operating efficiency of the LVAD was measured at between 8% and 10.5%. While the LVAD can provide adequate pump outflow for cardiac assistance, further upgrading of the software and improvement of the blood pump are required to improve pump performance and efficiency. PMID:17846714

  9. Simulation of a pulsatile total artificial heart: Development of a partitioned Fluid Structure Interaction model

    Science.gov (United States)

    Sonntag, Simon J.; Kaufmann, Tim A. S.; Büsen, Martin R.; Laumen, Marco; Linde, Torsten; Schmitz-Rode, Thomas; Steinseifer, Ulrich

    2013-04-01

    Heart disease is one of the leading causes of death in the world. Due to a shortage in donor organs artificial hearts can be a bridge to transplantation or even serve as a destination therapy for patients with terminal heart insufficiency. A pusher plate driven pulsatile membrane pump, the Total Artificial Heart (TAH) ReinHeart, is currently under development at the Institute of Applied Medical Engineering of RWTH Aachen University.This paper presents the methodology of a fully coupled three-dimensional time-dependent Fluid Structure Interaction (FSI) simulation of the TAH using a commercial partitioned block-Gauss-Seidel coupling package. Partitioned coupling of the incompressible fluid with the slender flexible membrane as well as a high fluid/structure density ratio of about unity led inherently to a deterioration of the stability (‘artificial added mass instability’). The objective was to conduct a stable simulation with high accuracy of the pumping process. In order to achieve stability, a combined resistance and pressure outlet boundary condition as well as the interface artificial compressibility method was applied. An analysis of the contact algorithm and turbulence condition is presented. Independence tests are performed for the structural and the fluid mesh, the time step size and the number of pulse cycles. Because of the large deformation of the fluid domain, a variable mesh stiffness depending on certain mesh properties was specified for the fluid elements. Adaptive remeshing was avoided. Different approaches for the mesh stiffness function are compared with respect to convergence, preservation of mesh topology and mesh quality. The resulting mesh aspect ratios, mesh expansion factors and mesh orthogonalities are evaluated in detail. The membrane motion and flow distribution of the coupled simulations are compared with a top-view recording and stereo Particle Image Velocimetry (PIV) measurements, respectively, of the actual pump.

  10. Amoxicillin pulsatile - MiddleBrook: APC 111, APC-111, PULSYS-enhanced amoxicillin.

    Science.gov (United States)

    2007-01-01

    MiddleBrook Pharmaceuticals (formerly Advancis Pharmaceutical) is developing an improved version of amoxicillin using its pulsatile oral drug delivery technology, called PULSYS. Amoxicillin PULSYS is intended to provide a lower treatment dose, once-daily alternative to currently approved amoxicillin and penicillin regimens for the treatment of adolescents/adults with pharyngitis and/or tonsillitis. If amoxicillin PULSYS is approved, it will be the first and only once-daily amoxicillin therapy approved for use in the US. Regulatory submissions for the treatment of pharyngitis/tonsillitis have been made in the US. Amoxicillin PULSYS is in clinical development for the treatment of pharyngitis and/or tonsillitis due to group A streptococcal infections in adolescents/adults as a tablet formulation. MiddleBrook was conducting clinical development of a sprinkle formulation for children. However, this has been put on hold for financial reasons. MiddleBrook is seeking regulatory approval for this product as a 505(b)(2) product, which is one that is not considered to be a completely new product, but is also not a generic product. It is a product with some differences from a previously approved product and clinical data to support such differences are required; however, the basic safety and efficacy studies may have been conducted by other organisations. In June 2007, Advancis Pharmaceutical was renamed as MiddleBrook Pharmaceuticals, Inc. MiddleBrook and Par Pharmaceuticals entered a co-promotion agreement for this product in June 2004. Par was to fund future development in exchange for co-exclusive marketing rights and exclusive rights to sell amoxicillin PULSYS. MiddleBrook retained responsibility for the manufacturing programme and also retained all patents and brand names and was responsible for their enforcement. However, this collaboration was subsequently terminated in August 2005 by Par Pharmaceutical. MiddleBrook received the US $4.75 million R&D reimbursement

  11. Growth Hormone Deficiency in Children

    Science.gov (United States)

    ... which the body does not make enough growth hormone (GH). GH is made by the pituitary gland, a ... blood test checks levels of IGF-1, a hormone that reflects GH levels. • GH stimulation test. The child is given ...

  12. Aging changes in hormone production

    Science.gov (United States)

    ... that produce hormones are controlled by other hormones. Aging also changes this process. For example, an endocrine ... produce the same amount at a slower rate. AGING CHANGES The hypothalamus is located in the brain. ...

  13. 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 ...

  14. SHBG (Sex Hormone Binding Globulin)

    Science.gov (United States)

    ... as: Testosterone-estrogen Binding Globulin; TeBG Formal name: Sex Hormone Binding Globulin Related tests: Testosterone , Free Testosterone, ... I should know? How is it used? The sex hormone binding globulin (SHBG) test may be used ...

  15. Hormonal contraception and venous thromboembolism

    DEFF Research Database (Denmark)

    Lidegaard, Øjvind; Milsom, Ian; Geirsson, Reynir Tomas;

    2012-01-01

    New studies about the influence of hormonal contraception on the risk of venous thromboembolism (VTE) have been published.......New studies about the influence of hormonal contraception on the risk of venous thromboembolism (VTE) have been published....

  16. 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...

  17. Radioimmunoassay of steroid hormone

    International Nuclear Information System (INIS)

    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 3H. 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.)

  18. Transdermal iontophoresis of gonadotropin releasing hormone (LHRH) and two analogues.

    Science.gov (United States)

    Miller, L L; Kolaskie, C J; Smith, G A; Rivier, J

    1990-06-01

    Gonadotropin releasing hormone (GnRH), as well as an antagonist [Ac-D2Nal,1 D4ClPhe,2 D3Pal,3 NicLys,5 DNicLys,6 ILys,8 DAla10] GnRH.HOAc (1) and a superagonist [DTrp6, Pro9-NHEt]GnRH (2), have been electrochemically driven across excised hairless mouse skin. Determined by HPLC analysis, the delivery rate from aqueous solution into isotonic saline at 0.5 mA cm-2 was as high as 19 nM cm-2 h-1 for 2. Because of its insolubility in water, analogue 1 could only be delivered from an acidic donor solution. Analogue 2 was also delivered in pulsatile fashion using current on/off cycles. For all three peptides, passive transport was negligible and stability is evident when in contact with the stratum corneum. Slow metabolism occurs when GnRH contacts the dermal side of hairless mouse skin. PMID:2203894

  19. Hormone Therapy for Breast Cancer in Men

    Science.gov (United States)

    ... Topic Targeted therapy for breast cancer in men Hormone therapy for breast cancer in men Hormone therapy ... fatigue, and pain at the injection site. Luteinizing hormone-releasing hormone (LHRH) analogs and anti-androgens LHRH ...

  20. The Effect of Boundary Slip on the Transient Pulsatile Flow of a Modified Second-Grade Fluid

    OpenAIRE

    Khajohnsaksumeth, N.; B. Wiwatanapataphee; Wu, Y. H.

    2013-01-01

    We investigate the effect of boundary slip on the transient pulsatile fluid flow through a vessel with body acceleration. The Fahraeus-Lindqvist effect, expressing the fluid behavior near the wall by the Newtonian fluid while in the core by a non-Newtonian fluid, is also taken into account. To describe the non-Newtonian behavior, we use the modified second-grade fluid model in which the viscosity and the normal stresses are represented in terms of the shear rate. The complete set of equations...

  1. 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....

  2. 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....

  3. Laboratory Evaluation of Hemolysis and Systemic Inflammatory Response in Neonatal Nonpulsatile and Pulsatile Extracorporeal Life Support Systems.

    Science.gov (United States)

    Wang, Shigang; Krawiec, Conrad; Patel, Sunil; Kunselman, Allen R; Song, Jianxun; Lei, Fengyang; Baer, Larry D; Ündar, Akif

    2015-09-01

    The objective of this study was to compare the systemic inflammatory response and hemolytic characteristics of a conventional roller pump (HL20-NP) and an alternative diagonal pump with nonpulsatile (DP3-NP) and pulsatile mode (DP3-P) in simulated neonatal extracorporeal life support (ECLS) systems. The experimental neonatal ECLS circuits consist of a conventional Jostra HL20 roller pump or an alternative Medos DP3 diagonal pump, and Medos Hilite 800 LT hollow-fiber oxygenator with diffusion membrane. Eighteen sterile circuits were primed with freshly donated whole blood and divided into three groups: conventional HL20 with nonpulsatile flow (HL20-NP), DP3 with nonpulsatile flow (DP3-NP), and DP3 with pulsatile flow (DP3-P). All trials were conducted for durations of 12 h at a flow rate of 500 mL/min at 36°C. Simultaneous blood flow and pressure waveforms were recorded. Blood samples were collected to measure plasma-free hemoglobin (PFH), human tumor necrosis factor-alpha, interleukin-6 (IL-6), and IL-8, in addition to the routine blood gas, lactate dehydrogenase, and lactic acid levels. HL20-NP group had the highest PFH levels (mean ± standard error of the mean) after a 12-h ECLS run, but the difference among groups did not reach statistical significance (HL20-NP group: 907.6 ± 253.1 mg/L, DP3-NP group: 343.7 ± 163.2 mg/L, and DP3-P group: 407.6 ± 156.6 mg/L, P = 0.06). Although there were similar trends but no statistical differences for the levels of proinflammatory cytokines among the three groups, the HL20-NP group had much greater levels than the other groups (P > 0.05). Pulsatile flow generated higher total hemodynamic energy and surplus hemodynamic energy levels at pre-oxygenator and pre-clamp sites (P < 0.01). Our study demonstrated that the alternative diagonal pump ECLS circuits appeared to have less systemic inflammatory response and hemolysis compared with the conventional roller pump ECLS circuit in simulated

  4. Multidetector CT imaging of mechanical prosthetic heart valves: quantification of artifacts with a pulsatile in-vitro model

    OpenAIRE

    Symersky, P.; Budde, R. P. J.; Westers, P.; Mol, de, B.A.J.M.; Prokop, M

    2011-01-01

    Objectives Multidetector computed tomography (MDCT) can detect the cause of prosthetic heart valve (PHV) dysfunction but is hampered by valve-induced artifacts. We quantified artifacts of four PHV using a pulsatile in-vitro model and assessed the relation to leaflet motion and valve design. Methods A Medtronic Hall tilting disc (MH), and Carbomedics (CM), St Jude (SJM), and ON-X bileaflet valves underwent CT in an in-vitro model using retrospective gating with a 64 detector CT system in stati...

  5. 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...

  6. Growth Hormone: Use and Abuse

    Science.gov (United States)

    ... is huma n gr owth hormone? Human growth hormone (GH) is a substance that controls your body’s growth. ... prescribed for the FDA-approved conditions. In children, GH is used to treat • Growth hormone deficiency • Conditions that cause short stature (being shorter ...

  7. High Frequency Pulsatile Electromagnetic Fields and Ultrasound Pulsatile Fields Impact on Germination Dynamic at Ocimum basilicum L. and O. basilicum var. purpurascens Benth., Observed with Open Source Software’s

    Directory of Open Access Journals (Sweden)

    Ioan ONAC

    2016-06-01

    Full Text Available Basil (Ocimum sp., generally knowned as “king of herbs” due to its pharmaceutical and culinary properties, is considered to be a native plant derived from Africa and Asia. Ocimum sp. grows in tropical and sub-tropical regions with more than 50 species knowned till present time. Germination percent of Ocimum sp. is considered to be between 85-95%. Even though Ocimum sp. are considered to have fast germination velocity index (GVI, short mean germination time (MGT and increased seedling vigor index (SVI values, their experimental monitoring is done with specialized software’s that are expensive. Low cost scientific solutions are keen on open source software germination protocols. For observing the accuracy of open source C.A.D. software’s Ocimum sp. seeds where submitted to high frequency pulsatile electromagnetic fields (300 impulses/3 peak penetrance - 293 W and ultrasound pulsatile fields (1/2 pulses by 0.5 W/cm2. All sequence images where taken using a positive/negative photo filter enhancing differences in seed development. At the end of the experiment all images where transformed into vector formats (dwg. On the dwg extension, selective free plug-ins such as Face Centroid and Area Properties help to collect data like seed development on X/Y scale, area, perimeter, no. of germinated seeds, length of seedling root, hypocotyl length.

  8. Pulsatile support using a rotary left ventricular assist device with an electrocardiography-synchronized rotational speed control mode for tracking heart rate variability.

    Science.gov (United States)

    Arakawa, Mamoru; Nishimura, Takashi; Takewa, Yoshiaki; Umeki, Akihide; Ando, Masahiko; Kishimoto, Yuichiro; Kishimoto, Satoru; Fujii, Yutaka; Date, Kazuma; Kyo, Shunei; Adachi, Hideo; Tatsumi, Eisuke

    2016-06-01

    We previously developed a novel control system for a continuous-flow left ventricular assist device (LVAD), the EVAHEART, and demonstrated that sufficient pulsatility can be created by increasing its rotational speed in the systolic phase (pulsatile mode) in a normal heart animal model. In the present study, we assessed this system in its reliability and ability to follow heart rate variability. We implanted an EVAHEART via left thoracotomy into five goats for the Study for Fixed Heart Rate with ventricular pacing at 80, 100, 120 and 140 beats/min and six goats for the Study for native heart rhythm. We tested three modes: the circuit clamp, the continuous mode and the pulsatile mode. In the pulsatile mode, rotational speed was increased during the initial 35 % of the RR interval by automatic control based on the electrocardiogram. Pulsatility was evaluated by pulse pressure and dP/dt max of aortic pressure. As a result, comparing the pulsatile mode with the continuous mode, the pulse pressure was 28.5 ± 5.7 vs. 20.3 ± 7.9 mmHg, mean dP/dt max was 775.0 ± 230.5 vs 442.4 ± 184.7 mmHg/s at 80 bpm in the study for fixed heart rate, respectively (P < 0.05). The system successfully determined the heart rate to be 94.6 % in native heart rhythm. Furthermore, pulse pressure was 41.5 ± 7.9 vs. 27.8 ± 5.6 mmHg, mean dP/dt max was 716.2 ± 133.9 vs 405.2 ± 86.0 mmHg/s, respectively (P < 0.01). In conclusion, our newly developed the pulsatile mode for continuous-flow LVADs reliably provided physiological pulsatility with following heart rate variability. PMID:26608806

  9. Pituitary carcinoma with different hormone expressions

    OpenAIRE

    Lu, Tao; Wang, Ren-Zhi; Zhao-hui ZHU; Ding-rong ZHONG

    2015-01-01

    Objective To introduce the experience of diagnosing and treating one case of pituitary carcinoma with distinct hormone expressions in primary and metastatic lesions and to improve understanding of this disease.  Methods Retrospective study was performed to analyze the clinical manifestations, imaging characteristics, histopathologic findings, and treatment information of the patient. Immunohistochemical staining was done to both primary and metastatic lesions.  Results The patient pre...

  10. Hormonal control of implantation.

    Science.gov (United States)

    Sandra, Olivier

    2016-06-01

    In mammals, implantation represents a key step of pregnancy and its progression conditions not only the success of pregnancy but health of the offspring. Implantation requires a complex and specific uterine tissue, the endometrium, whose biological functions are tightly regulated by numerous signals, including steroids and polypeptide hormones. Endometrial tissue is endowed with dynamic properties that associate its ability to control the developmental trajectory of the embryo (driver property) and its ability to react to embryos displaying distinct capacities to develop to term (sensor property). Since dynamical properties of the endometrium can be affected by pre- and post-conceptional environment, determining how maternal hormonal signals and their biological actions are affected by environmental factors (e.g. nutrition, stress, infections) is mandatory to reduce or even to prevent their detrimental effects on endometrial physiology in order to preserve the optimal functionality of this tissue. PMID:27172870

  11. Hormones in pregnancy

    Directory of Open Access Journals (Sweden)

    Pratap Kumar

    2012-01-01

    Full Text Available The endocrinology of human pregnancy involves endocrine and metabolic changes that result from physiological alterations at the boundary between mother and fetus. Progesterone and oestrogen have a great role along with other hormones. The controversies of use of progestogen and others are discussed in this chapter. Progesterone has been shown to stimulate the secretion of Th2 and reduces the secretion of Th1 cytokines which maintains pregnancy. Supportive care in early pregnancy is associated with a significant beneficial effect on pregnancy outcome. Prophylactic hormonal supplementation can be recommended for all assisted reproduction techniques cycles. Preterm labor can be prevented by the use of progestogen. The route of administration plays an important role in the drug′s safety and efficacy profile in different trimesters of pregnancy. Thyroid disorders have a great impact on pregnancy outcome and needs to be monitored and treated accordingly. Method of locating review: Pubmed, scopus

  12. Pulsatile flow in the aorta of the LVAD supported heart studied using particle image velocimetry

    Science.gov (United States)

    Moyedi, Zahra

    Currently many patients die because of the end-stage heart failure, mainly due to the reduced number of donor heart transplant organs. Studies show that a permanent left ventricular assist device (LVAD), a battery driven pump which is surgically implanted, increased the survival rate of patients with end-stage heart failure and improved considerably their quality of life. The inlet conduit of the LVAD is attached to the left ventricle and the outflow conduit anastomosed to the ascending aorta. The purpose of LVAD support is to help a weakened heart to pump blood to the rest of the body. However LVAD can cause some alterations of the natural blood flow. When your blood comes in contact with something that isn't a natural part of your body blood clots can occur and disrupt blood flow. Aortic valve integrity is vital for optimal support of left ventricular assist LVAD. Due to the existence of high continuous transvalvular pressure on the aortic valve, the opening frequency of the valve is reduced. To prevent the development of aortic insufficiency, aortic valve closure during LVAD implantation has been performed. However, the closed aortic valve reduces wash out of the aortic root, which causes blood stagnation and potential thrombus formation. So for this reason, there is a need to minimize the risks of occurring blood clot, by having more knowledge about the flow structure in the aorta during LVAD use. The current study focuses on measuring the flow field in the aorta of the LVAD assisted heart with two different types of aortic valve (Flat and Finned) using the SDSU cardiac simulator. The pulsatile pump that mimics the natural pulsing action of the heart also added to the system. The flow field is visualized using Particle Image Velocimetry (PIV). Furthermore, The fluid mechanics of aorta has been studied when LVAD conduit attached to two different locations (proximal and distal to the aortic valve) with pump speeds of 8,000 to 10,000 revolutions per minute (RPM

  13. Reference ranges for uterine artery pulsatility index during the menstrual cycle: a cross-sectional study.

    Directory of Open Access Journals (Sweden)

    Luís Guedes-Martins

    Full Text Available Cyclic endometrial neoangiogenesis contributes to changes in local vascular patterns and is amenable to non-invasive assessment with Doppler sonography. We hypothesize that the uterine artery (UtA impedance, measured by its pulsatility index (PI, exhibits a regular pattern during the normal menstrual cycle. Therefore, the main study objective was to derive normative new day-cycle-based reference ranges for the UtA-PI during the entire cycle from days 1 to 34 according to the isolated time effect and potential confounders such as age and parity.From January 2009 to December 2012, a cross-sectional study of 1,821 healthy women undergoing routine gynaecological ultrasound was performed. The Doppler flow of the right and left UtA-PI was studied transvaginally by colour and pulsed Doppler imaging. The mean right and left values and the presence or absence of a bilateral protodiastolic notch were recorded. Reference intervals for the PI according to the cycle day were generated by classical linear regression.The majority of patients (97.5% presented unilateral or bilateral UtA notches. The crude 5th, 50th, and 95th reference percentile curves of the UtA-PI at 1-34 days of the normal menstrual cycle were derived. In all curves, a progressive significant decrease occurred during the first 13 days, followed by an increase and recovery in the UtA-PI. The adjusted 5th, 50th, and 95th reference percentile curves for the effects of age and parity were also obtained. These two conditions generated an approximately identical UtA-PI pattern during the cycle, except with small but significant reductions at the temporal extremes.The median, 5th, and the 95th percentiles of the UtA-PI decrease during the first third of the menstrual cycle and recover to their initial values during the last two thirds of the cycle. The rates of decrease and recovery depend significantly on age and parity.

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

    International Nuclear Information System (INIS)

    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 ∗ 10−9 m2/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

  15. Simultaneous assessment of red blood cell aggregation and oxygen saturation under pulsatile flow using high-frequency photoacoustics

    Science.gov (United States)

    Bok, Tae-Hoon; Hysi, Eno; Kolios, Michael C.

    2016-01-01

    We investigate the feasibility of photoacoustic (PA) imaging for assessing the correlation between red blood cell (RBC) aggregation and the oxygen saturation (sO2) in a simulated pulsatile blood flow system. For the 750 and 850 nm illuminations, the PA amplitude (PAA) increased and decreased as the mean blood flow velocity decreased and increased, respectively, at all beat rates (60, 120 and 180 bpm). The sO2 also cyclically varied, in phase with the PAA for all beat rates. However, the linear correlation between the sO2 and the PAA at 850 nm was stronger than that at 750 nm. These results suggest that the sO2 can be correlated with RBC aggregation induced by decreased mean shear rate in pulsatile flow, and that the correlation is dependent on the optical wavelength. The hemodynamic properties of blood flow assessed by PA imaging may be used to provide a new biomarker for simultaneous monitoring blood viscosity related to RBC aggregation, oxygen delivery related to the sO2 and their clinical correlation.

  16. Simultaneous assessment of red blood cell aggregation and oxygen saturation under pulsatile flow using high-frequency photoacoustics.

    Science.gov (United States)

    Bok, Tae-Hoon; Hysi, Eno; Kolios, Michael C

    2016-07-01

    We investigate the feasibility of photoacoustic (PA) imaging for assessing the correlation between red blood cell (RBC) aggregation and the oxygen saturation (sO2) in a simulated pulsatile blood flow system. For the 750 and 850 nm illuminations, the PA amplitude (PAA) increased and decreased as the mean blood flow velocity decreased and increased, respectively, at all beat rates (60, 120 and 180 bpm). The sO2 also cyclically varied, in phase with the PAA for all beat rates. However, the linear correlation between the sO2 and the PAA at 850 nm was stronger than that at 750 nm. These results suggest that the sO2 can be correlated with RBC aggregation induced by decreased mean shear rate in pulsatile flow, and that the correlation is dependent on the optical wavelength. The hemodynamic properties of blood flow assessed by PA imaging may be used to provide a new biomarker for simultaneous monitoring blood viscosity related to RBC aggregation, oxygen delivery related to the sO2 and their clinical correlation. PMID:27446705

  17. A novel hydrogel plug of Sterculia urens for pulsatile delivery: in vitro and in vivo evaluation.

    Science.gov (United States)

    Amrutkar, Jitendra R; Gattani, Surendra G

    2012-01-01

    The objective of this study was to investigate a novel hydrogel plug using isolated root mucilage of Sterculia urens to obtain a desired lag time for an oral chronotherapeutic colon-specific pulsatile drug delivery of indomethacin. Pulsatile drug delivery was developed using chemically treated hard gelatin capsule bodies filled with eudragit multiparticulates of indomethacin, and sealed with different hydrogel plugs (root mucilage of S. urens, xanthan gum, guar gum, HPMC K4M and combination of maltodextrin with guar gum). Indomethacin multiparticulates were prepared using extrusion spheronization, spray drying and solvent evaporation techniques with Eudragit® L-100 and S-100 (1:2) by varying drug-to-polymer ratio. After oral administration, the water-soluble cap of capsule dissolved in the intestinal fluid and the hydrogel plug swells. After a controlled time, the swollen plug subsequently ejected from the dosage form, releases the contents of the capsule. The formulation factors affecting the drug release were concentration and types of hydrogel plug used. In vivo gamma scintigraphy study in healthy rabbits proved the capability of the system to release drug in lower parts of the gastrointestinal tract after a programmed lag time. This study demonstrates that the indomethacin multiparticulates could be successfully colon-targeted by the design of time and pH-dependent modified chronopharmaceutical formulation. In conclusion, the investigated novel hydrogel plug could be a valuable tool for achieving desired lag time. PMID:22034955

  18. Sensitivity and specificity of pulsatility index umbilical artery and middle cerebral artery in detecting intra uterine growth restriction

    International Nuclear Information System (INIS)

    To determine the sensitivity and specificity of the pulsatile index in umbilical artery (PI-UA) and pulsatile index in middle cerebral artery (PI-MCA) in detecting IUGR by comparing it with the birth weight. Study Design: Validation Study. Place and Duration of Study: Study was conducted in Department of Radiology, Military Hospital and Combined Military Hospital Rawalpindi, which was equipped with the (Aloka SSD-5500) using 3.5 MHz transducer after seeking permission from hospital ethical committee from 1st January 2010 to 10th January 2010. Subjects and Methods: Two hundred and fifty pregnant women with IUGR in third trimester were included in the study. Ultrasound estimation of fetal weight (using fetal biometry) below 10th percentile for that gestational age was labeled as IUGR. PI-MCA value of less than 11 was labeled as abnormal. PI-UA value of more than 1.451 was labeled as abnormal. Birth weight was taken as gold standard. Results: Sensitivity of PI-UA were 94.8% and 79.8%, respectively. Specificity of PI-UA and PI-MCA were 36.8% and 90.7%, respectively. Conclusion: Raised PI value of UA is highly sensitive of IUGR; lower PI value of MCA is highly specific of IUGR and grave sign of fetal demise. (author)

  19. Application of design of experiment for polyox and xanthan gum coated floating pulsatile delivery of sumatriptan succinate in migraine treatment.

    Science.gov (United States)

    Jagdale, Swati C; Pawar, Chandrakala R

    2014-01-01

    Migraine follows circadian rhythm in which headache is more painful at the awakening time. This needs administration of dosage form at night time to release drug after lag period when pain gets worse. Sumatriptan succinate is a drug of choice for migraine. Sumatriptan succinate has bitter taste, low oral bioavailability, and shorter half-life. Present work deals with application of design of experiment for polyox and xanthan gum in development of press coated floating pulsatile tablet. Floating pulsatile concept was applied to increase gastric residence of the dosage form. Burst release was achieved through immediate release tablet using crospovidone as superdisintegrant (10%). Pulse lag time was achieved using swellable polymer polyox WSR 205 and xanthan gum. 3(2) experimental design was applied. Optimized formulation was evaluated for physical characteristics and in-vitro and in-vivo study. From results, it can be concluded that optimized batch F8 containing polyox WSR205 (72.72%) and xanthan gum (27.27%) of total weight of polymer has shown floating lag time of 55 ± 2 sec, drug content of 100.35 ± 0.4%, hardness of 6 ± 0.1 Kg/cm(2), and 98.69 ± 2% drug release in pulse manner with lag time of 7 ± 0.1 h. Optimized batch showed prolong gastric residence which was confirmed by in-vivo X-ray study. PMID:25530963

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

    International Nuclear Information System (INIS)

    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 (R2 = 0.982) and a mean absolute error (e) of 0.323 L min−1, while for head, R2 = 0.933 and e = 7.682 mmHg were obtained. R2 = 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

  1. An Ultrasound Simulation Model for the Pulsatile Blood Flow Modulated by the Motion of Stenosed Vessel Wall.

    Science.gov (United States)

    Zhang, Qinghui; Zhang, Yufeng; Zhou, Yi; Zhang, Kun; Zhang, Kexin; Gao, Lian

    2016-01-01

    This paper presents an ultrasound simulation model for pulsatile blood flow, modulated by the motion of a stenosed vessel wall. It aims at generating more realistic ultrasonic signals to provide an environment for evaluating ultrasound signal processing and imaging and a framework for investigating the behaviors of blood flow field modulated by wall motion. This model takes into account fluid-structure interaction, blood pulsatility, stenosis of the vessel, and arterial wall movement caused by surrounding tissue's motion. The axial and radial velocity distributions of blood and the displacement of vessel wall are calculated by solving coupled Navier-Stokes and wall equations. With these obtained values, we made several different phantoms by treating blood and the vessel wall as a group of point scatterers. Then, ultrasound echoed signals from oscillating wall and blood in the axisymmetric stenotic-carotid arteries were computed by ultrasound simulation software, Field II. The results show better consistency with corresponding theoretical values and clinical data and reflect the influence of wall movement on the flow field. It can serve as an effective tool not only for investigating the behavior of blood flow field modulated by wall motion but also for quantitative or qualitative evaluation of new ultrasound imaging technology and estimation method of blood velocity. PMID:27478840

  2. Multidetector CT imaging of mechanical prosthetic heart valves: quantification of artifacts with a pulsatile in-vitro model

    Energy Technology Data Exchange (ETDEWEB)

    Symersky, Petr [Onze Lieve Vrouwe Gasthuis, Department of Cardiothoracic Surgery, Oosterpark 9, P.O box 95500, Amsterdam (Netherlands); Academic Medical Center, Department of Cardiothoracic Surgery, Amsterdam (Netherlands); Budde, Ricardo P.J. [University Medical Center, Department of Radiology, Utrecht (Netherlands); Westers, Paul [Julius Center for Health Sciences and Primary Care, Department of Biostatistics, Utrecht (Netherlands); Mol, Bas A.J.M. de [Academic Medical Center, Department of Cardiothoracic Surgery, Amsterdam (Netherlands); University of Technology Eindhoven, Department of Biomedical Engineering, Eindhoven (Netherlands); Prokop, Mathias [Radboud University Nijmegen Medical Center, Department of Radiology, Nijmegen (Netherlands)

    2011-10-15

    Multidetector computed tomography (MDCT) can detect the cause of prosthetic heart valve (PHV) dysfunction but is hampered by valve-induced artifacts. We quantified artifacts of four PHV using a pulsatile in-vitro model and assessed the relation to leaflet motion and valve design. A Medtronic Hall tilting disc (MH), and Carbomedics (CM), St Jude (SJM), and ON-X bileaflet valves underwent CT in an in-vitro model using retrospective gating with a 64 detector CT system in stationary and pulsatile conditions. Artifacts and radiopaque component volumes were quantified with thresholds based on surrounding structures and valvular components. Hypodense artifacts volumes (mm{sup 3}) were 1,029 {+-} 147, 535 {+-} 53, 371 {+-} 16, and 366 {+-} 18 for the SJM, MH, CM and ON-X valves (p < 0.001 except for the latter two valves p = 0.43). Hyperdense artifact volumes were 3,546 {+-} 141, 2,387 {+-} 103, 2,003 {+-} 102, and 3,033 {+-} 31 for the SJM, MH, CM and ON-X valve, respectively (all differences p < 0.001). Leaflet motion affected hypodense (F = 41.5, p < 0.001) and hyperdense artifacts (F = 53.7, p < 0.001). Closed and moving leaflets were associated with the least and the most artifacts respectively (p < 0.001, both artifact types). Both valve design and leaflet motion affect PHV-induced artifacts. Best imaging results may be expected for the CM valve during phases in which the leaflets are closed. (orig.)

  3. The wound hormone jasmonate

    OpenAIRE

    Koo, Abraham J.K.; Howe, Gregg A.

    2009-01-01

    Plant tissues are highly vulnerable to injury by herbivores, pathogens, mechanical stress, and other environmental insults. Optimal plant fitness in the face of these threats relies on complex signal transduction networks that link damage-associated signals to appropriate changes in metabolism, growth, and development. Many of these wound-induced adaptive responses are triggered by de novo synthesis of the plant hormone jasmonate (JA). Recent studies provide evidence that JA mediates systemic...

  4. Growth Hormone Promotes Lymphangiogenesis

    OpenAIRE

    Banziger-Tobler, Nadja Erika; Halin, Cornelia; Kajiya, Kentaro; Detmar, Michael

    2008-01-01

    The lymphatic system plays an important role in inflammation and cancer progression, although the molecular mechanisms involved are poorly understood. As determined using comparative transcriptional profiling studies of cultured lymphatic endothelial cells versus blood vascular endothelial cells, growth hormone receptor was expressed at much higher levels in lymphatic endothelial cells than in blood vascular endothelial cells. These findings were confirmed by quantitative real-time reverse tr...

  5. Profile of thyroid hormones in breast cancer patients

    OpenAIRE

    Saraiva P.P.; Figueiredo N.B.; Padovani C.R.; Brentani M.M.; Nogueira C.R.

    2005-01-01

    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 analyze...

  6. Analyzing in the Present

    DEFF Research Database (Denmark)

    Revsbæk, Line; Pedersen, Lene Tanggaard

    2015-01-01

    The article presents a notion of “analyzing in the present” as a source of inspiration in analyzing qualitative research materials. The term emerged from extensive listening to interview recordings during everyday commuting to university campus. Paying attention to the way different parts of...... various interviews conveyed diverse significance to the listening researcher at different times became a method of continuously opening up the empirical material in a reflexive, breakdown-oriented process of analysis. We argue that situating analysis in the present of analyzing emphasizes and acknowledges...... contributes to an ongoing methodological conversation problematizing the notion of “data” and the use of “data-reliant” methods of analysis....

  7. A quantitative study of CSF pulsatile flow in normal pressure hydrocephalus; An analysis of flow patterns before and after a shunting procedure using cine MR phase imaging

    Energy Technology Data Exchange (ETDEWEB)

    Katayama, Shinji; Makabe, Tetsuo; Itoh, Takahiko (Okayama Univ. (Japan). School of Medicine) (and others)

    1992-06-01

    In the previous report, we described the visualization and quantitative analysis of a normal CSF pulsatile flow using cine MR phase imaging. In the present study, CSF flow velocities were measured in patients with normal pressure hydrocephalus (NPH) before and after a shunting procedure. All of the healthy subjects showed a similar flow pattern in the time-velocity flow profiles (TVFP). However, patients with NPH showed a variable pattern of TVFP and could be divided into the following four types: Type 0: the CSF flow pattern was similar to that of the healthy subjects. Type I: the caudal peak flow was delayed more than 190 msec on TVFP. Type II: the caudal peak flow was not apparent, but the CSF flow through the aqueduct was remarkable on phase images. Type III: the amplitude of TVFP was very small, and no CSF flow through the aqueduct was identified. The patients with Type III TVFP showed significantly lower NPH scores. The lumbar CSF pressures tended to be high in the patients with Type III TVFP, but nevertheless failed to reach a statistically significant level. The amplitude of TVFP increased in the patients who improved clinically after the shunting procedure. Some of the Type III patients changed into Type II, I, and 0; also, one of the Type II patients changed into a Type I patients after the shunting procedure. We conclude that cine MR phase imaging is useful for analyzing the CSF flow of the patients with NPH before and after the shunting procedure as well as for evaluating shunt patency. (author).

  8. Transmastoid reshaping of the sigmoid sinus: preliminary study of a novel surgical method to quiet pulsatile tinnitus of an unrecognized vascular origin.

    Science.gov (United States)

    Kim, Chong Sun; Kim, So Young; Choi, Hyunseok; Koo, Ja-Won; Yoo, Shin-Young; An, Gwang Seok; Lee, Kyogu; Choi, Inyong; Song, Jae-Jin

    2016-08-01

    OBJECTIVE A dominant sigmoid sinus with focal dehiscence or thinning (DSSD/T) of the overlying bony wall is a commonly encountered, but frequently overlooked, cause of vascular pulsatile tinnitus (VPT). Also, the pathophysiological mechanism of sound perception in patients with VPT remains poorly understood. In the present study, a novel surgical method, termed transmastoid SS-reshaping surgery, was introduced to ameliorate VPT in patients with DSSD/T. The authors reviewed a case series, analyzed the surgical outcomes, and suggested the pathophysiological mechanism of sound perception. The theoretical background underlying VPT improvement after transmastoid SS-reshaping surgery was also explored. METHODS Eight patients with VPT that was considered attributable to DSSD/T underwent transmastoid SS-reshaping surgery between February 2010 and February 2015. The mean postoperative follow-up period was 9.5 months (range 4-13 months). Transmastoid SS-reshaping surgery featured simple mastoidectomy, partial compression of the SS using harvested cortical bone chips, and reinforcement of the bony SS wall with bone cement. Perioperative medical records, imaging results, and audiological findings were comprehensively reviewed. RESULTS In 7 of the 8 patients (87.5%), the VPT abated immediately after surgery. Statistically significant improvements in tinnitus loudness and distress were evident on numeric rating scales. Three patients with preoperative ipsilesional low-frequency hearing loss exhibited postoperative improvements in their low-frequency hearing thresholds. No major postoperative complications were encountered except in the first subject, who experienced increased intracranial pressure postoperatively. This subsided after a revision operation for partial decompression of the SS. CONCLUSIONS Transmastoid SS-reshaping surgery may be a good surgical option in patients with DSSD/T, a previously unrecognized cause of VPT. Redistribution of severely asymmetrical blood flow

  9. Miniature mass analyzer

    CERN Document Server

    Cuna, C; Lupsa, N; Cuna, S; Tuzson, B

    2003-01-01

    The paper presents the concept of different mass analyzers that were specifically designed as small dimension instruments able to detect with great sensitivity and accuracy the main environmental pollutants. The mass spectrometers are very suited instrument for chemical and isotopic analysis, needed in environmental surveillance. Usually, this is done by sampling the soil, air or water followed by laboratory analysis. To avoid drawbacks caused by sample alteration during the sampling process and transport, the 'in situ' analysis is preferred. Theoretically, any type of mass analyzer can be miniaturized, but some are more appropriate than others. Quadrupole mass filter and trap, magnetic sector, time-of-flight and ion cyclotron mass analyzers can be successfully shrunk, for each of them some performances being sacrificed but we must know which parameters are necessary to be kept unchanged. To satisfy the miniaturization criteria of the analyzer, it is necessary to use asymmetrical geometries, with ion beam obl...

  10. Software Design Analyzer System

    Science.gov (United States)

    Tausworthe, R. C.

    1985-01-01

    CRISP80 software design analyzer system a set of programs that supports top-down, hierarchic, modular structured design, and programing methodologies. CRISP80 allows for expression of design as picture of program.

  11. Ten-year adjuvant hormone therapy for breast cancer: the pros and cons (a review of literature

    Directory of Open Access Journals (Sweden)

    S. M. Portnoy

    2014-07-01

    Full Text Available Tamoxifen is one of the basic drugs of adjuvant hormone therapy in patients with hormone-dependent breast tumors. The purpose of this paper is to analyze the results of randomized trials of long-term adjuvant hormone therapy for breast cancer.

  12. Ten-year adjuvant hormone therapy for breast cancer: the pros and cons (a review of literature)

    OpenAIRE

    S. M. Portnoy; T. A. Shendrikova

    2014-01-01

    Tamoxifen is one of the basic drugs of adjuvant hormone therapy in patients with hormone-dependent breast tumors. The purpose of this paper is to analyze the results of randomized trials of long-term adjuvant hormone therapy for breast cancer.

  13. Total organic carbon analyzer

    Science.gov (United States)

    Godec, Richard G.; Kosenka, Paul P.; Smith, Brian D.; Hutte, Richard S.; Webb, Johanna V.; Sauer, Richard L.

    1991-01-01

    The development and testing of a breadboard version of a highly sensitive total-organic-carbon (TOC) analyzer are reported. Attention is given to the system components including the CO2 sensor, oxidation reactor, acidification module, and the sample-inlet system. Research is reported for an experimental reagentless oxidation reactor, and good results are reported for linearity, sensitivity, and selectivity in the CO2 sensor. The TOC analyzer is developed with gravity-independent components and is designed for minimal additions of chemical reagents. The reagentless oxidation reactor is based on electrolysis and UV photolysis and is shown to be potentially useful. The stability of the breadboard instrument is shown to be good on a day-to-day basis, and the analyzer is capable of 5 sample analyses per day for a period of about 80 days. The instrument can provide accurate TOC and TIC measurements over a concentration range of 20 ppb to 50 ppm C.

  14. Quo vadis plant hormone analysis?

    OpenAIRE

    Tarkowská, D. (Danuše); Novák, O. (Ondřej); Floková, K. (Kristýna); Tarkowski, P.; Turečková, V. (Veronika); Grúz, J. (Jiří); Rolčík, J. (Jakub); Strnad, M.

    2014-01-01

    Plant hormones act as chemical messengers in the regulation of myriads of physiological processes that occur in plants. To date, nine groups of plant hormones have been identified and more will probably be discovered. Furthermore, members of each group may participate in the regulation of physiological responses in planta both alone and in concert with members of either the same group or other groups. The ideal way to study biochemical processes involving these signalling molecules is 'hormon...

  15. Mammalian sex hormones in plants

    OpenAIRE

    Andrzej Skoczowski; Anna Janeczko

    2011-01-01

    The occurrence of mammalian sex hormones and their physiological role in plants is reviewed. These hormones, such as 17β-estradiol, androsterone, testosterone or progesterone, were present in 60-80% of the plant species investigated. Enzymes responsible for their biosynthesis and conversion were also found in plants. Treatment of the plants with sex hormones or their precursors influenced plant development: cell divisions, root and shoot growth, embryo growth, flowering, pollen tube ...

  16. Hormones and Borderline Personality Features

    OpenAIRE

    Evardone, Milagros; Alexander, Gerianne M.; Morey, Leslie C.

    2008-01-01

    Borderline personality is diagnosed in clinical settings three times more often in women than in men, and symptom severity in women appears sensitive to circulating sex steroid levels. In non-human mammals, prenatal hormones contribute to the development of sex-linked behavior and their responsiveness to postnatal hormones. Therefore, this study examined the hypothesis that prenatal hormones may influence the development of borderline personality traits by measuring a marker of perinatal andr...

  17. Growth hormone and aging

    OpenAIRE

    Bartke, Andrzej; Brown-Borg, Holly; Kinney, Beth; Mattison, Julie; Wright, Chris; Hauck, Steven; Coschigano, Karen; Kopchick, John

    2000-01-01

    The potential usefulness of growth hormone (GH) as an anti-aging therapy is of considerable current interest. Secretion of GH normally declines during aging and administration of GH can reverse age-related changes in body composition. However, mutant dwarf mice with congenital GH deficiency and GH resistant GH-R-KO mice live much longer than their normal siblings, while a pathological elevation of GH levels reduces life expectancy in both mice and men. We propose that the actions of GH on gro...

  18. Pulmonary artery pulsatility and effect on vessel diameter assessment in magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Shariat, Masoud, E-mail: masoudshariat@gmail.com [Department of Medical Imaging, University Health Network, University of Toronto, Toronto, Ontario (Canada); Department of Diagnostic Imaging, Hospital for Sick Children, Toronto, Ontario (Canada); Schantz, Daryl, E-mail: daryl.schantz@gmail.com [Department of Diagnostic Imaging, Hospital for Sick Children, Toronto, Ontario (Canada); Yoo, Shi-Joon, E-mail: shi-joon.yoo@sickkids.ca [Department of Diagnostic Imaging, Hospital for Sick Children, Toronto, Ontario (Canada); Wintersperger, Bernd J., E-mail: bernd.wintersperger@uhn.ca [Department of Medical Imaging, University Health Network, University of Toronto, Toronto, Ontario (Canada); Seed, Mike, E-mail: mike.seed@sickkids.ca [Department of Diagnostic Imaging, Hospital for Sick Children, Toronto, Ontario (Canada); Department of Cardiology, Hospital for Sick Children, Toronto, Ontario (Canada); Alnafisi, Bahiyah, E-mail: bahiyah.alnafisi@uhn.ca [Department of Medical Imaging, University Health Network, University of Toronto, Toronto, Ontario (Canada); Chu, Leysia, E-mail: leysia_99@yahoo.com [Department of Diagnostic Imaging, Hospital for Sick Children, Toronto, Ontario (Canada); MacGowan, Christopher K., E-mail: christopher.macgowan@sickkids.ca [Department of Physiology and Experimental Medicine, Hospital for Sick Children, Toronto, Ontario (Canada); Amerom, Joshua van, E-mail: Joshu.vanamerom@sickkids.ca [Department of Physiology and Experimental Medicine, Hospital for Sick Children, Toronto, Ontario (Canada); Grosse-Wortmann, Lars, E-mail: lars.grosse-wortmann@sickkids.ca [Department of Diagnostic Imaging, Hospital for Sick Children, Toronto, Ontario (Canada); Department of Cardiology, Hospital for Sick Children, Toronto, Ontario (Canada)

    2014-02-15

    systolic cine SSFP or MRA in both groups (p < 0.0001). Vessel diameters measured on systolic SSFP were significantly larger than measurements made on diastolic SSFP (p < 0.0001). There was no significant difference between vessel measurements on MRA and measurements on systolic cine SSFP (p = 0.44 for the TOF group and p = 0.79 for ARVC group). Measurements on the MRA datasets were significantly larger than those on diastolic SSFP images (p < 0.0001). Conclusion: Black blood, white blood and MRA sequences are all reproducible CMR methods for the assessment of arterial diameters in children and adolescents. Measurements from systolic phase SSFP images are comparable to those from contrast-enhanced MRA. Therefore, the administration of contrast medium is not necessary in every case. Cine SSFP images offer the additional advantage over the other methods in such that both the largest and the smallest diameter of the vessel during the cardiac cycle can be assessed using this technique. This is even more relevant in highly pulsatile circulations, such as patients with repaired TOF and significant pulmonary insufficiency.

  19. Pulmonary artery pulsatility and effect on vessel diameter assessment in magnetic resonance imaging

    International Nuclear Information System (INIS)

    systolic cine SSFP or MRA in both groups (p < 0.0001). Vessel diameters measured on systolic SSFP were significantly larger than measurements made on diastolic SSFP (p < 0.0001). There was no significant difference between vessel measurements on MRA and measurements on systolic cine SSFP (p = 0.44 for the TOF group and p = 0.79 for ARVC group). Measurements on the MRA datasets were significantly larger than those on diastolic SSFP images (p < 0.0001). Conclusion: Black blood, white blood and MRA sequences are all reproducible CMR methods for the assessment of arterial diameters in children and adolescents. Measurements from systolic phase SSFP images are comparable to those from contrast-enhanced MRA. Therefore, the administration of contrast medium is not necessary in every case. Cine SSFP images offer the additional advantage over the other methods in such that both the largest and the smallest diameter of the vessel during the cardiac cycle can be assessed using this technique. This is even more relevant in highly pulsatile circulations, such as patients with repaired TOF and significant pulmonary insufficiency

  20. List mode multichannel analyzer

    Science.gov (United States)

    Archer, Daniel E.; Luke, S. John; Mauger, G. Joseph; Riot, Vincent J.; Knapp, David A.

    2007-08-07

    A digital list mode multichannel analyzer (MCA) built around a programmable FPGA device for onboard data analysis and on-the-fly modification of system detection/operating parameters, and capable of collecting and processing data in very small time bins (<1 millisecond) when used in histogramming mode, or in list mode as a list mode MCA.

  1. Centrifugal analyzer development

    International Nuclear Information System (INIS)

    The development of the centrifuge fast analyzer (CFA) is reviewed. The development of a miniature CFA with computer data analysis is reported and applications for automated diagnostic chemical and hematological assays are discussed. A portable CFA system with microprocessor was adapted for field assays of air and water samples for environmental pollutants, including ammonia, nitrates, nitrites, phosphates, sulfates, and silica. 83 references

  2. An efficient approach to study the pulsatile blood flow in femoral and coronary arteries by Differential Quadrature Method

    Science.gov (United States)

    Ghasemi, Seiyed E.; Hatami, M.; Hatami, J.; Sahebi, S. A. R.; Ganji, D. D.

    2016-02-01

    In this paper, flow analysis for a non-Newtonian third grade blood in coronary and femoral arteries is simulated numerically. Blood is considered as the third grade non-Newtonian fluid under periodic body acceleration motion and pulsatile pressure gradient. Differential Quadrature Method (DQM) and Crank Nicholson Method (CNM) are used to solve the Partial Differential Equation (PDE) governing equation by which a good agreement between them was observed in the results. The influences of some physical parameters such as amplitude, lead angle and body acceleration frequency on non-dimensional velocity and profiles are considered. For instance, the results show that increasing the amplitude, Ag, and reducing the lead angle of body acceleration, ϕ, make higher velocity profiles in the center line of both arteries.

  3. Pulsatile Tinnitus due to a Tortuous Siphon-Like Internal Carotid Artery Successfully Treated by Arterial Remodeling

    Directory of Open Access Journals (Sweden)

    Dirk De Ridder

    2013-01-01

    Full Text Available A patient is described with a right-sided tortuous siphon-like extracranial internal carotid artery leading to highly distressing ipsilateral heart beat synchronous pulsatile tinnitus, scoring 9/10 measuring loudness. Dilating the balloon during the occlusion test in or distal to the siphon-like anomaly reduces the arterial pulsations. Subsequently, surgery is performed using Teflon as an external construct to straighten the siphon-like anomaly. Postoperatively, the pulsations improve to 5/10 in a standing position and disappear during a reclined position. By adding a hearing aid, the pulsations are almost completely gone during a standing position (1/10 and remain absent in a reclined position.

  4. Piecewise function parameters as responses of the design of experiment in the development of a pulsatile release chronopharmaceutical system.

    Science.gov (United States)

    Vonica-Gligor, Andreea Loredana; Tomuţă, Ioan; Leucuţa, Sorin E

    2016-06-01

    The aim of this work was to develop a pulsatile release system with metoprolol for chronotherapeutical use by coating swellable mini-tablets with Eudragit RS. To study the influence of the formulation factors (amount of coating polymer, plasticizer percentage in film coating and swelling agent percentage in mini-tablets), a Box-Behnken design of experiment (DoE) was used. To evaluate the influence of the studied factors on the sigmoid shape of the dissolution profile, piecewise function parameters were used as the responses of DoE. The results show that higher concentrations of coating polymer and higher concentrations of plasticizer polymer led to a thicker and more elastic polymeric film, which led to a delay in drug release. Using the parameters of the piecewise function as DoE responses, an optimum formulation with a sigmoid shape dissolution profile and a 2.5-h lag time followed by rapid drug release were obtained. PMID:27279062

  5. Analyzed Using Statistical Moments

    International Nuclear Information System (INIS)

    Diffraction enhanced imaging (DEl) technique is a new x-ray imaging method derived from radiography. The method uses a monorheumetten x-ray beam and introduces an analyzer crystal between an object and a detector Narrow angular acceptance of the analyzer crystal generates an improved contrast over the evaluation radiography. While standart radiography can produce an 'absorption image', DEl produces 'apparent absorption' and 'apparent refraction' images with superior quality. Objects with similar absorption properties may not be distinguished with conventional techniques due to close absorption coefficients. This problem becomes more dominant when an object has scattering properties. A simple approach is introduced to utilize scattered radiation to obtain 'pure absorption' and 'pure refraction' images

  6. PhosphoSiteAnalyzer

    DEFF Research Database (Denmark)

    Bennetzen, Martin V; Cox, Jürgen; Mann, Matthias; Andersen, Jens S.

    2012-01-01

    Phosphoproteomic experiments are routinely conducted in laboratories worldwide, and because of the fast development of mass spectrometric techniques and efficient phosphopeptide enrichment methods, researchers frequently end up having lists with tens of thousands of phosphorylation sites for...... sets that have been subjected to kinase prediction using the previously published NetworKIN algorithm. NetworKIN applies sophisticated linear motif analysis and contextual network modeling to obtain kinase-substrate associations with high accuracy and sensitivity. PhosphoSiteAnalyzer provides an...

  7. Lear CAN analyzer

    OpenAIRE

    Peiró Ibañez, Felipe

    2013-01-01

    Since it was introduced in the automotive industry, the protocol CAN (Controller Area Network) has been widely used for its benefits. This has led many companies to offer several hardware and software solutions in order to monitor the communications that gives this protocol. The current master thesis presents the Lear CAN Analyzer as a software tool developed within the company LEAR Corporation. It is designed to be used in the automobile industry as a complement or substitute for other co...

  8. Analyzing business process management

    OpenAIRE

    Skjæveland, Børge

    2013-01-01

    Within the Oil & Gas Industry, the market is constantly growing more competitive, forcing companies to continually adapt to changes. Companies need to cut costs and improve the business efficiency. One way of successfully managing these challenges is to implement business process management in the organization. This thesis will analyze how Oceaneering Asset Integrity AS handled the implementation of a Business Process Management System and the effects it had on the employees. The main goal...

  9. Magnetoresistive Emulsion Analyzer

    OpenAIRE

    Lin, Gungun; Baraban, Larysa; Han, Luyang; Karnaushenko, Daniil; Makarov, Denys; Cuniberti, Gianaurelio; Schmidt, Oliver G.

    2013-01-01

    We realize a magnetoresistive emulsion analyzer capable of detection, multiparametric analysis and sorting of ferrofluid-containing nanoliter-droplets. The operation of the device in a cytometric mode provides high throughput and quantitative information about the dimensions and magnetic content of the emulsion. Our method offers important complementarity to conventional optical approaches involving ferrofluids, and paves the way to the development of novel compact tools for diagnostics and n...

  10. Radioisotope analyzer of barium

    International Nuclear Information System (INIS)

    Principle of operation and construction of radioisotope barium sulphate analyzer type MZB-2 for fast determination of barium sulphate content in barite ores and enrichment products are described. The gauge equipped with Am-241 and a scintillation detector enables measurement of barium sulphate content in prepared samples of barite ores in the range 60% - 100% with the accuracy of 1%. The gauge is used in laboratories of barite mine and ore processing plant. 2 refs., 2 figs., 1 tab. (author)

  11. IPv6 Protocol Analyzer

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    With the emerging of next generation Intemet protocol (IPv6), it is expected to replace the current version of Internet protocol (IPv4) that will be exhausted in the near future. Besides providing adequate address space, some other new features are included into the new 128 bits of IP such as IP auto configuration, quality of service, simple routing capability, security, mobility and multicasting. The current protocol analyzer will not be able to handle IPv6 packets. This paper will focus on developing protocol analyzer that decodes IPv6 packet. IPv6 protocol analyzer is an application module,which is able to decode the IPv6 packet and provide detail breakdown of the construction of the packet. It has to understand the detail construction of the IPv6, and provide a high level abstraction of bits and bytes of the IPv6 packet.Thus it increases network administrators' understanding of a network protocol,helps he/she in solving protocol related problem in a IPv6 network environment.

  12. 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.

  13. Chronomodulated press-coated pulsatile therapeutic system for aceclofenac: optimization of factors influencing drug release and lag time

    Directory of Open Access Journals (Sweden)

    et al

    2011-02-01

    Full Text Available Sumit Patil1, Swati Pund2, Amita Joshi2, Chamanlal J Shishoo2, Aliasgar Shahiwala11Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research (NIPER, Ahmedabad, India; 2Department of Pharmaceutics, BV Patel PERD Centre, Ahmedabad, IndiaBackground: The objective of this study was to develop and evaluate a press-coated pulsatile drug delivery system intended for treatment of early morning stiffness and symptomatic relief from pain in patients with rheumatoid arthritis.Methods: The formulation involved press coating of a rupturable coat around a rapidly disintegrating core tablet of aceclofenac. A three-factor, two-level, full factorial design was used to investigate the influence of amount of glyceryl behenate, amount of sodium chloride in the coating composition, and the coating level on the responses, ie, lag time to release and amount of aceclofenac released in 450 minutes.Results: Glyceryl behenate and the coating level had a significant influence on lag time, while sodium chloride helped in the rupture of the coat by acting as a channeling agent. After the coat was ruptured, the core tablet showed a rapid release of aceclofenac due to the presence of Ac-Di-Sol®. Graphical analysis of effects by Lenth's method and Bayesian analysis of coefficients enabled identification of variables active on the selected responses. The optimized formulation comprised 20% w/w glyceryl behenate and 2.2% w/w sodium chloride with a 650 mg coating level, and showed a desired lag time of 358.23 minutes, which mimics the fluctuating symptoms of rheumatoid arthritis, followed by rapid release of aceclofenac.Keywords: chronotherapy, pulsatile delivery, rupturable coat, aceclofenac 

  14. DynPeak: an algorithm for pulse detection and frequency analysis in hormonal time series.

    Directory of Open Access Journals (Sweden)

    Alexandre Vidal

    Full Text Available 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.

  15. Alternatives of menopausal hormone therapy

    OpenAIRE

    Kutlešić Ranko M.; Popović Jasmina; Stefanović Milan; Vukomanović Predrag; Lukić Bojan; Lilić Goran

    2016-01-01

    Introduction. It has been generally accepted that the benefits of menopausal hormone therapy outweigh the risks, but there are still some concerns about the administration of menopausal hormone therapy, which has introduced alternative treatments. Pharmacological Alternatives. Central alpha-2 agonist clonidine is only marginally more effective than placebo, and significantly less effective than estrogen. Antiepileptic drug gabapentin reduces hot flashes; ho...

  16. Hormonal control of inflammatory responses

    Directory of Open Access Journals (Sweden)

    J. Garcia-Leme

    1993-01-01

    Full Text Available Almost any stage of inflammatory and immunological responses is affected by hormone actions. This provides the basis for the suggestion that hormones act as modulators of the host reaction against trauma and infection. Specific hormone receptors are detected in the reactive structures in inflamed areas and binding of hormone molecules to such receptors results in the generation of signals that influence cell functions relevant for the development of inflammatory responses. Diversity of hormonal functions accounts for recognized pro- and anti-inflammatory effects exerted by these substances. Most hormone systems are capable of influencing inflammatory events. Insulin and glucocorticoids, however, exert direct regulatory effects at concentrations usually found in plasma. Insulin is endowed with facilitatory actions on vascular reactivity to inflammatory mediators and inflammatory cell functions. Increased concentrations of circulating glucocorticoids at the early stages of inflammation results in downregulation of inflammatory responses. Oestrogens markedly reduce the response to injury in a variety of experimental models. Glucagon and thyroid hormones exert indirect anti-inflammatory effects mediated by the activity of the adrenal cortex. Accordingly, inflammation is not only merely a local response, but a hormone-controlled process.

  17. Recent advances in hormonal contraception

    OpenAIRE

    Li, HW Raymond; Richard A. Anderson

    2010-01-01

    This report reviews some of the new studies regarding new hormonal contraceptive formulations (e.g., Yaz, Qlaira®, extended-cycle or continuous combined contraceptives, subcutaneous depot medroxyprogesterone acetate, and ulipristal acetate as an emergency contraceptive). Recent data on the relationship between hormonal contraceptive use and bone health are also reviewed. © 2010 Medicine Reports Ltd.

  18. Hormonal contraception, thrombosis and age

    DEFF Research Database (Denmark)

    Lidegaard, Øjvind

    2014-01-01

    INTRODUCTION: This paper reviews the risk of thrombosis with use of different types of hormonal contraception in women of different ages. AREAS COVERED: Combined hormonal contraceptives with desogestrel, gestodene, drospirenone or cyproterone acetate (high-risk products) confer a sixfold increased...

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

    International Nuclear Information System (INIS)

    A radioimmunoassay for bovine (bLH), ovine (oLH) and porcine (pLH) luteinizing hormone was developed using a human 125ILH 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 μg/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.)

  20. [Do hormones determine our fate?].

    Science.gov (United States)

    Vermeulen, A

    1994-01-01

    The hormonal system is a communication system between cells and organs. Hence it is not surprising that it influences almost all physiological functions and, at least partially, our behaviour and fate. The sexual phenotype is determined by the sex hormones. Normally, the phenotype is in accordance with gonadal and genetic sex, but occasionally, as a consequence of enzymatic defects in the biosynthesis of sex hormones or of androgen resistance, gonadal and genetic sex are in discordance with the phenotype, the latter determining generally the civil sex and the sex of rearing. Whereas the gender role is generally determined by the sex of rearing and the phenotype, itself under hormonal influence, homo- and transsexuality constitute notorious exceptions to this rule. Although several authors consider homo- and transsexuality to be the consequence of an impairment in androgenic impregnation in the perinatal period, there are at present no convincing arguments for an hormonal origin for either homo- or transsexuality, although such a possibility can't be excluded either. Besides their role in psychosexual behaviour, sex hormones play also a role in our life expectancy. Indeed, although maximal life expectancy of man is genetically determined, a major determinant of individual life expectancy is cardiovascular pathology. The latter is partly responsible for the difference in life expectancy between men and women, cardiovascular mortality increasing rapidly at menopause and being halved by oestrogen replacement therapy. Also atherogenesis as such is, to a large extend, under hormonal control. Indeed insulin resistance and hyperinsulinism, which develop as a corollary of the aging process, is an important cause of atherosclerosis as well as of hypertension. Other hormones also play an important role in our behaviour. We can mention here the role of the thyroid hormones in the physical and mental development of children as well as in the regression of the intellectual

  1. Estrogen and Progestin (Hormone Replacement Therapy)

    Science.gov (United States)

    Combinations of estrogen and progestin are used to treat certain symptoms of menopause. Estrogen and progestin are two female sex hormones. Hormone replacement therapy works by replacing estrogen hormone that is no longer being made by ...

  2. Genetics Home Reference: combined pituitary hormone deficiency

    Science.gov (United States)

    ... Genetics Home Health Conditions combined pituitary hormone deficiency combined pituitary hormone deficiency Enable Javascript to view the ... boxes. Print All Open All Close All Description Combined pituitary hormone deficiency is a condition that causes ...

  3. Fluorescence analyzer for lignin

    Science.gov (United States)

    Berthold, John W.; Malito, Michael L.; Jeffers, Larry

    1993-01-01

    A method and apparatus for measuring lignin concentration in a sample of wood pulp or black liquor comprises a light emitting arrangement for emitting an excitation light through optical fiber bundles into a probe which has an undiluted sensing end facing the sample. The excitation light causes the lignin concentration to produce fluorescent emission light which is then conveyed through the probe to analyzing equipment which measures the intensity of the emission light. Measures a This invention was made with Government support under Contract Number DOE: DE-FC05-90CE40905 awarded by the Department of Energy (DOE). The Government has certain rights in this invention.

  4. Analyzing Chinese Financial Reporting

    Institute of Scientific and Technical Information of China (English)

    SABRINA; ZHANG

    2008-01-01

    If the world’s capital markets could use a harmonized accounting framework it would not be necessary for a comparison between two or more sets of accounting standards. However,there is much to do before this becomes reality.This article aims to pres- ent a general overview of China’s General Accepted Accounting Principles(GAAP), U.S.General Accepted Accounting Principles and International Financial Reporting Standards(IFRS),and to analyze the differ- ences among IFRS,U.S.GAAP and China GAAP using fixed assets as an example.

  5. Trial of Recombinant Follicle-Stimulating Hormone Pretreatment for GnRH-Induced Fertility in Patients with Congenital Hypogonadotropic Hypogonadism

    Science.gov (United States)

    Dwyer, Andrew A.; Sykiotis, Gerasimos P.; Hayes, Frances J.; Boepple, Paul A.; Lee, Hang; Loughlin, Kevin R.; Dym, Martin; Sluss, Patrick M.; Crowley, William F.

    2013-01-01

    Context and Objective: The optimal strategy for inducing fertility in men with congenital hypogonadotropic hypogonadism (CHH) is equivocal. Albeit a biologically plausible approach, pretreatment with recombinant FSH (rFSH) before GnRH/human chorionic gonadotropin administration has not been sufficiently assessed. The objective of the study was to test this method. Design and Setting: This was a randomized, open-label treatment protocol at an academic medical center. Patients and Interventions: GnRH-deficient men (CHH) with prepubertal testes (<4 mL), no cryptorchidism, and no prior gonadotropin therapy were randomly assigned to either 24 months of pulsatile GnRH therapy alone (inducing endogenous LH and FSH release) or 4 months of rFSH pretreatment followed by 24 months of GnRH therapy. Patients underwent serial testicular biopsies, ultrasound assessments of testicular volume, serum hormone measurements, and seminal fluid analyses. Results: rFSH treatment increased inhibin B levels into the normal range (from 29 ± 9 to 107 ± 41 pg/mL, P < .05) and doubled testicular volume (from 1.1 ± 0.2 to 2.2 ± 0.3 mL, P < .005). Histological analysis showed proliferation of both Sertoli cells (SCs) and spermatogonia, a decreased SC to germ cell ratio (from 0.74 to 0.35), and SC cytoskeletal rearrangements. With pulsatile GnRH, the groups had similar hormonal responses and exhibited significant testicular growth. All men receiving rFSH pretreatment developed sperm in their ejaculate (7 of 7 vs 4 of 6 in the GnRH-only group) and showed trends toward higher maximal sperm counts. Conclusions: rFSH pretreatment followed by GnRH is successful in inducing testicular growth and fertility in men with CHH with prepubertal testes. rFSH not only appears to maximize the SC population but also induces morphologic changes, suggesting broader developmental roles. PMID:24037890

  6. Leptin: a multifunctional hormone

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Leptin is the protein product encoded by the obese (ob)gene. It is a circulating hormone produced primarily by the adipose tissue. ob/ob mice with mutations of the gene encoding leptin become morbidly obese, infertile, hyperphagic, hypothermic,and diabetic. Since the cloning of leptin in 1994, our knowledge in body weight regulation and the role played by leptin has increased substantially. We now know that leptin signals through its receptor, OB-R, which is a member of the cytokine receptor superfamily. Leptin serves as an adiposity signal to inform the brain the adipose tissue mass in a negative feedback loop regulating food intake and energy expenditure. Leptin also plays important roles in angiogenesis, immune function, fertility, and bone formation. Humans with mutations in the gene encoding leptin are also morbidly obese and respond to leptin treatment,demonstrating that enhancing or inhibiting leptin's activities in vivo may have potential therapeutic benefits.

  7. Field Deployable DNA analyzer

    Energy Technology Data Exchange (ETDEWEB)

    Wheeler, E; Christian, A; Marion, J; Sorensen, K; Arroyo, E; Vrankovich, G; Hara, C; Nguyen, C

    2005-02-09

    This report details the feasibility of a field deployable DNA analyzer. Steps for swabbing cells from surfaces and extracting DNA in an automatable way are presented. Since enzymatic amplification reactions are highly sensitive to environmental contamination, sample preparation is a crucial step to make an autonomous deployable instrument. We perform sample clean up and concentration in a flow through packed bed. For small initial samples, whole genome amplification is performed in the packed bed resulting in enough product for subsequent PCR amplification. In addition to DNA, which can be used to identify a subject, protein is also left behind, the analysis of which can be used to determine exposure to certain substances, such as radionuclides. Our preparative step for DNA analysis left behind the protein complement as a waste stream; we determined to learn if the proteins themselves could be analyzed in a fieldable device. We successfully developed a two-step lateral flow assay for protein analysis and demonstrate a proof of principle assay.

  8. Ring Image Analyzer

    Science.gov (United States)

    Strekalov, Dmitry V.

    2012-01-01

    Ring Image Analyzer software analyzes images to recognize elliptical patterns. It determines the ellipse parameters (axes ratio, centroid coordinate, tilt angle). The program attempts to recognize elliptical fringes (e.g., Newton Rings) on a photograph and determine their centroid position, the short-to-long-axis ratio, and the angle of rotation of the long axis relative to the horizontal direction on the photograph. These capabilities are important in interferometric imaging and control of surfaces. In particular, this program has been developed and applied for determining the rim shape of precision-machined optical whispering gallery mode resonators. The program relies on a unique image recognition algorithm aimed at recognizing elliptical shapes, but can be easily adapted to other geometric shapes. It is robust against non-elliptical details of the image and against noise. Interferometric analysis of precision-machined surfaces remains an important technological instrument in hardware development and quality analysis. This software automates and increases the accuracy of this technique. The software has been developed for the needs of an R&TD-funded project and has become an important asset for the future research proposal to NASA as well as other agencies.

  9. Genetics Home Reference: isolated growth hormone deficiency

    Science.gov (United States)

    ... deficiency dwarfism, pituitary growth hormone deficiency dwarfism isolated GH deficiency isolated HGH deficiency isolated human growth hormone deficiency isolated somatotropin deficiency isolated somatotropin deficiency disorder ...

  10. Hormonal contraception and platelet function.

    Science.gov (United States)

    Saleh, A A; Ginsburg, K A; Duchon, T A; Dorey, L G; Hirata, J; Alshameeri, R S; Dombrowski, M P; Mammen, E F

    1995-05-15

    73 healthy women (29 controls, 25 using OCs, and 19 using Norplant) were selected from the clinic population at North Oakland Medical Center for inclusion in this study after obtaining informed consent. Age, race, height, weight, blood pressure, and cigarette smoking were recorded for each subject. 12 patients were on monophasic OCs while 13 were on triphasic preparations. Both hormonal contraceptive groups had used their particular contraceptive for at least 3 months prior to blood drawing. Platelet tests were performed within 2 hours of sample collection: platelet counts (PLC) and mean platelet volume (MPV) were determined on an Automated Platelet Counter (Baker 810 Platelet Analyzer). Whole blood aggregation was performed on a platelet aggregometer (Chrono-Log, Model 550) using both ADP (ADP, 5 mM) and collagen (COLL, 2 mcg/ml) as inducing agents. Demographic differences were not significant (p 0.05) among the 3 treatment groups, whose average age was 25.3-25.8 years old. Furthermore, no significant differences (p 0.05) in platelet function were detected among controls or subjects receiving either oral contraceptives or Norplant, compared to control patients. The mean platelet counts (X 10/9/L) were 223 for OC users, 231 for Norplant users, and 232 for controls. The respective platelet aggregation (ADP, ohms) values were 12.5, 18.0, and 19.2 as well as (COLL, ohms) 35.6, 40.7, and 39.0. These results demonstrated that there is no evidence for altered platelet function, with the testing methods employed, in women using either Norplant or combination low dose oral contraceptives. To date, several studies have examined this issue, with contradictory reports about the effects of hormonal contraceptives in platelet function. After controlling for differences between various steroid preparations and other such confounding variables, some of these conflicting conclusions could be the result of a lack of uniformity among the methods used to evaluate platelet aggregation

  11. Residual gas analyzer calibration

    Science.gov (United States)

    Lilienkamp, R. H.

    1972-01-01

    A technique which employs known gas mixtures to calibrate the residual gas analyzer (RGA) is described. The mass spectra from the RGA are recorded for each gas mixture. This mass spectra data and the mixture composition data each form a matrix. From the two matrices the calibration matrix may be computed. The matrix mathematics requires the number of calibration gas mixtures be equal to or greater than the number of gases included in the calibration. This technique was evaluated using a mathematical model of an RGA to generate the mass spectra. This model included shot noise errors in the mass spectra. Errors in the gas concentrations were also included in the valuation. The effects of these errors was studied by varying their magnitudes and comparing the resulting calibrations. Several methods of evaluating an actual calibration are presented. The effects of the number of gases in then, the composition of the calibration mixture, and the number of mixtures used are discussed.

  12. Analyzing Cosmic Bubble Collisions

    CERN Document Server

    Gobbetti, Roberto

    2012-01-01

    We develop a set of controlled, analytic approximations to study the effects of bubble collisions on cosmology. We expand the initial perturbation to the inflaton field caused by the collision in a general power series, and determine its time evolution during inflation in terms of the coefficients in the expansion. In models where the observer's bubble undergoes sufficient slow-roll inflation to solve the flatness problem, in the thin wall limit only one coefficient in the expansion is relevant to observational cosmology, allowing nearly model-independent predictions. We discuss two approaches to determining the initial perturbation to the inflaton and the implications for the sign of the effect (a hot or cold spot on the Cosmic Microwave Background temperature map). Lastly, we analyze the effects of collisions with thick-wall bubbles, i.e. away from the thin-wall limit.

  13. Analyzing business models

    DEFF Research Database (Denmark)

    Nielsen, Christian

    2014-01-01

    New types of disclosure and reporting are argued to be vital in order to convey a transparent picture of the true state of the company. However, they are unfortunately not without problems as these types of information are somewhat more complex than the information provided in the traditional......, because the costs of processing and analyzing it exceed the benefits indicating bounded rationality. Hutton (2002) concludes that the analyst community’s inability to raise important questions on quality of management and the viability of its business model inevitably led to the Enron debacle. There seems...... to be evidence of the fact that all types of corporate stakeholders from management to employees, owners, the media and politicians have grave difficulties in interpreting new forms of reporting. One hypothesis could be that if managements’ own understanding of value creation is disclosed to the...

  14. Analyzing architecture articles

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In the present study, we express the quality, function, and characteristics of architecture to help people comprehensively understand what architecture is. We also reveal the problems and conflict found in population, land, water resources, pollution, energy, and the organization systems in construction. China’s economy is transforming. We should focus on the cities, architectural environment, energy conservation, emission-reduction, and low-carbon output that will result in successful green development. We should macroscopically and microscopically analyze the development, from the natural environment to the artificial environment; from the relationship between human beings and nature to the combination of social ecology in cities, and farmlands. We must learn to develop and control them harmoniously and scientifically to provide a foundation for the methods used in architecture research.

  15. PDA: Pooled DNA analyzer

    Directory of Open Access Journals (Sweden)

    Lin Chin-Yu

    2006-04-01

    Full Text Available Abstract Background Association mapping using abundant single nucleotide polymorphisms is a powerful tool for identifying disease susceptibility genes for complex traits and exploring possible genetic diversity. Genotyping large numbers of SNPs individually is performed routinely but is cost prohibitive for large-scale genetic studies. DNA pooling is a reliable and cost-saving alternative genotyping method. However, no software has been developed for complete pooled-DNA analyses, including data standardization, allele frequency estimation, and single/multipoint DNA pooling association tests. This motivated the development of the software, 'PDA' (Pooled DNA Analyzer, to analyze pooled DNA data. Results We develop the software, PDA, for the analysis of pooled-DNA data. PDA is originally implemented with the MATLAB® language, but it can also be executed on a Windows system without installing the MATLAB®. PDA provides estimates of the coefficient of preferential amplification and allele frequency. PDA considers an extended single-point association test, which can compare allele frequencies between two DNA pools constructed under different experimental conditions. Moreover, PDA also provides novel chromosome-wide multipoint association tests based on p-value combinations and a sliding-window concept. This new multipoint testing procedure overcomes a computational bottleneck of conventional haplotype-oriented multipoint methods in DNA pooling analyses and can handle data sets having a large pool size and/or large numbers of polymorphic markers. All of the PDA functions are illustrated in the four bona fide examples. Conclusion PDA is simple to operate and does not require that users have a strong statistical background. The software is available at http://www.ibms.sinica.edu.tw/%7Ecsjfann/first%20flow/pda.htm.

  16. Genotoxic potential of nonsteroidal hormones

    Directory of Open Access Journals (Sweden)

    Topalović Dijana

    2015-01-01

    Full Text Available Hormones are cellular products involved in the regulation of a large number of processes in living systems, and which by their actions affect the growth, function and metabolism of cells. Considering that hormones are compounds normally present in the organism, it is important to determine if they can, under certain circumstances, lead to genetic changes in the hereditary material. Numerous experimental studies in vitro and in vivo in different systems, from bacteria to mammals, dealt with the mutagenic and genotoxic effects of hormones. This work presents an overview of the research on genotoxic effects of non­steroidal hormones, although possible changes of genetic material under their influence have not still been known enough, and moreover, investigations on their genotoxic influence have given conflicting results. The study results show that mechanisms of genotoxic effect of nonsteroidal hormones are manifested through the increase of oxidative stress by arising reactive oxygen species. A common mechanism of ROS occurence in thyroid hormones and catecholamines is through metabolic oxidation of their phenolic groups. Manifestation of insulin genotoxic effect is based on production of ROS by activation of NADPH isophorms, while testing oxytocin showed absence of genotoxic effect. Considering that the investigations on genotoxicity of nonsteroidal hormones demonstrated both positive and negative results, the explanation of this discordance involve limitations of test systems themselves, different cell types or biological species used in the experiments, different level of reactivity in vitro and in vivo, as well as possible variations in a tissue-specific expression. Integrated, the provided data contribute to better understanding of genotoxic effect of nonsteroidal hormones and point out to the role and mode of action of these hormones in the process of occurring of effects caused by oxidative stress. [Projekat Ministarstva nauke Republike

  17. Micro-electrolytic iodination of polypeptide hormones

    International Nuclear Information System (INIS)

    This report describes a constant voltage microelectrolytic 125I-labelling procedure and applies it to the iodination of 5-50 μg quantities of polypeptide hormones (synthetic salmon calcitonin, porcine glucagon, dog growth hormone, bovine growth hormone, bovine lutenizing hormone, bovine parathyroid hormone and bovine thyroid stimulating hormone). The electrolytic technique avoids exposure of the hormones to oxidizing agents which damage hormones and alter their biological and immunological activity. The labeled hormones showed no apparent damage by chromatoelectrophoresis or polyacrylamide gel filtration and all of the labelled hormones tested were either biologically or immunologically active. Finally, this simple, mild, and rapid micro-electrolytic iodination technique is highly reproducible, and rapid micro-electrolytic iodination technique is highly reproducible, yields a high degree of iodination and allows for the preparation of either high or low specific activity labeled hormone molecules. (author)

  18. Pseudostupidity and analyzability.

    Science.gov (United States)

    Cohn, L S

    1989-01-01

    This paper seeks to heighten awareness of pseudostupidity and the potential analyzability of patients who manifest it by defining and explicating it, reviewing the literature, and presenting in detail the psychoanalytic treatment of a pseudostupid patient. Pseudostupidity is caused by an inhibition of the integration and synthesis of thoughts resulting in a discrepancy between intellectual capacity and apparent intellect. The patient's pseudostupidity was determined in part by his need to prevent his being more successful than father, i.e., defeating his oedipal rival. Knowing and learning were instinctualized. The patient libidinally and defensively identified with father's passive, masochistic position. He needed to frustrate the analyst as he had felt excited and frustrated by his parents' nudity and thwarted by his inhibitions. He wanted to cause the analyst to feel as helpless as he, the patient, felt. Countertransference frustration was relevant and clinically useful in the analysis. Interpretation of evolving relevant issues led to more anxiety and guilt, less pseudostupidity, a heightened alliance, and eventual working through. Negative therapeutic reactions followed the resolution of pseudostupidity. PMID:2708771

  19. Downhole Fluid Analyzer Development

    Energy Technology Data Exchange (ETDEWEB)

    Bill Turner

    2006-11-28

    A novel fiber optic downhole fluid analyzer has been developed for operation in production wells. This device will allow real-time determination of the oil, gas and water fractions of fluids from different zones in a multizone or multilateral completion environment. The device uses near infrared spectroscopy and induced fluorescence measurement to unambiguously determine the oil, water and gas concentrations at all but the highest water cuts. The only downhole components of the system are the fiber optic cable and windows. All of the active components--light sources, sensors, detection electronics and software--will be located at the surface, and will be able to operate multiple downhole probes. Laboratory testing has demonstrated that the sensor can accurately determine oil, water and gas fractions with a less than 5 percent standard error. Once installed in an intelligent completion, this sensor will give the operating company timely information about the fluids arising from various zones or multilaterals in a complex completion pattern, allowing informed decisions to be made on controlling production. The research and development tasks are discussed along with a market analysis.

  20. Sex Hormones and Ischemic Stroke

    DEFF Research Database (Denmark)

    Holmegard, Haya N; Nordestgaard, Børge G; Jensen, Gorm B;

    2016-01-01

    = 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......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...

  1. 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 hormone (TSH) was negatively correlated with most maternal PFASs (r = -0.261 to -0.170, all P hormone homeostasis in humans.

  2. GnRH脉冲治疗对男性垂体柄中断综合征患者垂体-睾丸轴功能的影响%Effect of pulsatile GnRH therapy on pituitary-testicular axis function in male patients with pituitary stalk interruption syndrome

    Institute of Scientific and Technical Information of China (English)

    郑俊杰; 茅江峰; 伍学焱; 王曦; 刘兆祥; 黄炳昆

    2016-01-01

    Objective To evaluate the efficacy of pulsatile gonadotropin-releasing hormone(GnRH) therapy in male patients with pituitary stalk interruption syndrome (PSIS).Methods Fourteen male PSIS patients,who had received subcutaneous pulsatile GnRH therapy for at least four weeks at Peking Union Medical College Hospital from April 2014 to September 2015,were included in the study.Serum luteinizing hormone (LH),follicle-stimulating hormone (FSH),testosterone level,testicular volume and sperm in ejaculation were measured.After treatment for four weeks,subjects with serum LH ≥ 1.24 U/L were classified as "good response group",and others were classified as "poor response group".Results All patients were born by breech delivery and presented with absent pubertal development.Laboratory findings showed combined pituitary hormone deficiency in all patients.Pituitary stalk interruption syndrome was diagnosed based on MRI findings.Totally 11 out of 14 patients showed good response to pulsatile GnRH therapy.Their LH level increased from 0.32 (0.15,0.61) U/L to 4.34 (2.52,7.39) U/L(P < 0.001),FSH from 0.84 (0.30,1.50) U/L to 7.12 (4.53,10.09) U/L (P < 0.001);serum testosterone level from 0 (0,0.45) nmol/L to 2.46 (0.56,11.45) nmol/L (P =0.004) and testicular volume from 2.0 (2.0,4.0) ml to 4.0 (3.0,6.0) ml (P =0.005).Sperm was detected in seminal samples after treatment for 8 weeks in two patients and for 12 weeks in one patients.Three out of 14 patients showed poor response to pulsatile GnRH therapy.Conclusion Pulsatile GnRH therapy can effectively establish the pituitarytesticular axis function for most patients with pituitary stalk interruption syndrome,indicating enough reserve of gonadotrophs in the pituitary.%目的 评价促性腺激素释放激素(GnRH)脉冲治疗对男性垂体柄中断综合征(PSIS)患者垂体-睾丸轴功能的影响.方法 回顾性分析北京协和医院内分泌科2014年4月至2015年9月14例男性PSIS患者,应用GnRH皮下脉冲输注治

  3. Digital Microfluidics Sample Analyzer

    Science.gov (United States)

    Pollack, Michael G.; Srinivasan, Vijay; Eckhardt, Allen; Paik, Philip Y.; Sudarsan, Arjun; Shenderov, Alex; Hua, Zhishan; Pamula, Vamsee K.

    2010-01-01

    Three innovations address the needs of the medical world with regard to microfluidic manipulation and testing of physiological samples in ways that can benefit point-of-care needs for patients such as premature infants, for which drawing of blood for continuous tests can be life-threatening in their own right, and for expedited results. A chip with sample injection elements, reservoirs (and waste), droplet formation structures, fluidic pathways, mixing areas, and optical detection sites, was fabricated to test the various components of the microfluidic platform, both individually and in integrated fashion. The droplet control system permits a user to control droplet microactuator system functions, such as droplet operations and detector operations. Also, the programming system allows a user to develop software routines for controlling droplet microactuator system functions, such as droplet operations and detector operations. A chip is incorporated into the system with a controller, a detector, input and output devices, and software. A novel filler fluid formulation is used for the transport of droplets with high protein concentrations. Novel assemblies for detection of photons from an on-chip droplet are present, as well as novel systems for conducting various assays, such as immunoassays and PCR (polymerase chain reaction). The lab-on-a-chip (a.k.a., lab-on-a-printed-circuit board) processes physiological samples and comprises a system for automated, multi-analyte measurements using sub-microliter samples of human serum. The invention also relates to a diagnostic chip and system including the chip that performs many of the routine operations of a central labbased chemistry analyzer, integrating, for example, colorimetric assays (e.g., for proteins), chemiluminescence/fluorescence assays (e.g., for enzymes, electrolytes, and gases), and/or conductometric assays (e.g., for hematocrit on plasma and whole blood) on a single chip platform.

  4. 3D Computer Simulations of Pulsatile Human Blood Flows in Vessels and in the Aortic Arch: Investigation of Non-Newtonian Characteristics of Human Blood

    CERN Document Server

    Sultanov, Renat A; Engelbrekt, Brent; Blankenbecler, Richard

    2008-01-01

    Methods of Computational Fluid Dynamics are applied to simulate pulsatile blood flow in human vessels and in the aortic arch. The non-Newtonian behaviour of the human blood is investigated in simple vessels of actual size. A detailed time-dependent mathematical convergence test has been carried out. The realistic pulsatile flow is used in all simulations. Results of computer simulations of the blood flow in vessels of two different geometries are presented. For pressure, strain rate and velocity component distributions we found significant disagreements between our results obtained with realistic non-Newtonian treatment of human blood and widely used method in literature: a simple Newtonian approximation. A significant increase of the strain rate and, as a result, wall sear stress distribution, is found in the region of the aortic arch. We consider this result as theoretical evidence that supports existing clinical observations and those models not using non-Newtonian treatment underestimate the risk of disru...

  5. Pre-Treatment Objective Diagnosis and Post-Treatment Outcome Evaluation in Patients with Vascular Pulsatile Tinnitus Using Transcanal Recording and Spectro-Temporal Analysis

    Science.gov (United States)

    Choi, Inyong; Koo, Ja-Won; Lee, Kyogu

    2016-01-01

    Objective Although vascular pulsatile tinnitus (VPT) has been classified as “objective”, VPT is not easily recognizable or documentable in most cases. In response to this, we have developed transcanal sound recording (TSR) and spectro-temporal analysis (STA) for the objective diagnosis of VPT. By refining our initial method, we were able to apply TSR/STA to post-treatment outcome evaluation, as well as pre-treatment objective diagnosis. Methods TSR was performed on seven VPT patients and five normal controls before and after surgical or interventional treatment. VPT was recorded using an inserted microphone with the subjects placed in both upright and supine positions with 1) a neutral head position, 2) head rotated to the tinnitus side, 3) head rotated to the non-tinnitus side, and 4) a neutral position with ipsi-lesional manual cervical compression. The recorded signals were analyzed in both time and time-frequency domains by performing a short-time Fourier transformation. Results The pre-treatment ear canal signals of all VPT patients demonstrated pulse-synchronous periodic structures and acoustic characteristics that were representative of their presumptive vascular pathologies, whereas those the controls exhibited smaller peaks and weak periodicities. Compared with the pre-treatment signals, the post-treatment signals exhibited significantly reduced peak- and root mean square amplitudes upon time domain analysis. Additionally, further sub-band analysis confirmed that the pulse-synchronous signal of all subjects was not identifiable after treatment and, in particular, that the signal decrement was statistically significant at low frequencies. Moreover, the post-treatment signals of the VPT subjects revealed no significant differences when compared to those of the control group. Conclusion We reconfirmed that the TSR/STA method is an effective modality to objectify VPT. In addition, the potential role of the TSR/STA method in the objective evaluation of

  6. Pulsatile flow and heat transfer of a magneto-micropolar fluid through a stenosed artery under the influence of body acceleration

    OpenAIRE

    Shit, G. C.; Roy, M.

    2012-01-01

    With an aim to investigate the effect of externally imposed body acceleration and magnetic field on pulsatile flow of blood through an arterial segment having stenosis is under consideration in this paper. The flow of blood is presented by a unsteady micropolar fluid and the heat transfer characteristics have been taken into account. The non-linear equations that governing the flow are solved numerically using finite difference technique by employing a suitable coordinate transformation. The ...

  7. Dogmas and controversies in the handling of nitrogenous wastes: 5-HT2-like receptors are involved in triggering pulsatile urea excretion in the gulf toadfish, Opsanus beta.

    Science.gov (United States)

    McDonald, M Danielle; Walsh, Patrick J

    2004-05-01

    When injected arterially, serotonin (5-hydroxytryptamine; 5-HT) has been shown to elicit naturally sized urea pulse events in the gulf toadfish, Opsanus beta. The goal of the present study was to determine which 5-HT receptor(s) was involved in mediating this serotonergic stimulation of the pulsatile excretion mechanism. Toadfish were surgically implanted with caudal arterial catheters and intraperitoneal catheters and injected with either 8-OH-DPAT (1 micro mol kg(-1)), a selective 5-HT(1A) receptor agonist, alpha-methyl-5-HT (1 micro mol kg(-1)), a 5-HT(2) receptor agonist, or ketanserin, a 5-HT(2) receptor antagonist (0.01, 0.1, 1 and 10 micro mol kg(-1)) plus alpha-methyl-5-HT. 8-OH-DPAT injection did not mediate an increase in urea excretion, ruling out the involvement of 5-HT(1A) receptors in pulsatile excretion. However, within 5 min, alpha-methyl-5-HT injection caused an increase in the excretion of urea in >95% (N=27) of the fish injected, with an average pulse size of 652+/-102 micro mol N kg(-1) (N=26). With alpha-methyl-5-HT injection there was no corresponding increase in ammonia or [(3)H]PEG 4000 permeability. Urea pulses elicited by alpha-methyl-5-HT were inhibited in a dose-dependent fashion by the 5-HT(2) receptor antagonist ketanserin, which at low doses caused a significant inhibition of pulse size and at higher doses significantly inhibited the occurrence of pulsatile excretion altogether. However, neither 8-OH-DPAT nor alpha-methyl 5-HT injection had an effect on plasma cortisol or plasma urea concentrations. These findings suggest the involvement of a 5-HT(2)-like receptor in the regulation of pulsatile urea excretion. PMID:15143134

  8. 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.

  9. Soft Decision Analyzer

    Science.gov (United States)

    Steele, Glen; Lansdowne, Chatwin; Zucha, Joan; Schlensinger, Adam

    2013-01-01

    The Soft Decision Analyzer (SDA) is an instrument that combines hardware, firmware, and software to perform realtime closed-loop end-to-end statistical analysis of single- or dual- channel serial digital RF communications systems operating in very low signal-to-noise conditions. As an innovation, the unique SDA capabilities allow it to perform analysis of situations where the receiving communication system slips bits due to low signal-to-noise conditions or experiences constellation rotations resulting in channel polarity in versions or channel assignment swaps. SDA s closed-loop detection allows it to instrument a live system and correlate observations with frame, codeword, and packet losses, as well as Quality of Service (QoS) and Quality of Experience (QoE) events. The SDA s abilities are not confined to performing analysis in low signal-to-noise conditions. Its analysis provides in-depth insight of a communication system s receiver performance in a variety of operating conditions. The SDA incorporates two techniques for identifying slips. The first is an examination of content of the received data stream s relation to the transmitted data content and the second is a direct examination of the receiver s recovered clock signals relative to a reference. Both techniques provide benefits in different ways and allow the communication engineer evaluating test results increased confidence and understanding of receiver performance. Direct examination of data contents is performed by two different data techniques, power correlation or a modified Massey correlation, and can be applied to soft decision data widths 1 to 12 bits wide over a correlation depth ranging from 16 to 512 samples. The SDA detects receiver bit slips within a 4 bits window and can handle systems with up to four quadrants (QPSK, SQPSK, and BPSK systems). The SDA continuously monitors correlation results to characterize slips and quadrant change and is capable of performing analysis even when the

  10. Hormone Therapy for Prostate Cancer

    Science.gov (United States)

    ... agonists , which are sometimes called LHRH analogs, are synthetic proteins that are structurally similar to LHRH and ... gland to stop producing luteinizing hormone, which prevents testosterone from being produced. Treatment with an LHRH agonist ...

  11. Thyroid Hormone and Vascular Remodeling.

    Science.gov (United States)

    Ichiki, Toshihiro

    2016-03-01

    Both hyperthyroidism and hypothyroidism affect the cardiovascular system. Hypothyroidism is known to be associated with enhanced atherosclerosis and ischemic heart diseases. The accelerated atherosclerosis in the hypothyroid state has been traditionally ascribed to atherogenic lipid profile, diastolic hypertension, and impaired endothelial function. However, recent studies indicate that thyroid hormone has direct anti-atherosclerotic effects, such as production of nitric oxide and suppression of smooth muscle cell proliferation. These data suggest that thyroid hormone inhibits atherogenesis through direct effects on the vasculature as well as modification of risk factors for atherosclerosis. This review summarizes the basic and clinical studies on the role of thyroid hormone in vascular remodeling. The possible application of thyroid hormone mimetics to the therapy of hypercholesterolemia and atherosclerosis is also discussed. PMID:26558400

  12. Revisiting Thyroid Hormones in Schizophrenia

    Directory of Open Access Journals (Sweden)

    Nadine Correia Santos

    2012-01-01

    Full Text Available Thyroid hormones are crucial during development and in the adult brain. Of interest, fluctuations in the levels of thyroid hormones at various times during development and throughout life can impact on psychiatric disease manifestation and response to treatment. Here we review research on thyroid function assessment in schizophrenia, relating interrelations between the pituitary-thyroid axis and major neurosignaling systems involved in schizophrenia’s pathophysiology. These include the serotonergic, dopaminergic, glutamatergic, and GABAergic networks, as well as myelination and inflammatory processes. The available evidence supports that thyroid hormones deregulation is a common feature in schizophrenia and that the implications of thyroid hormones homeostasis in the fine-tuning of crucial brain networks warrants further research.

  13. 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...

  14. Plant hormone receptors: new perceptions

    OpenAIRE

    Spartz, Angela K.; William M Gray

    2008-01-01

    Plant growth and development require the integration of a variety of environmental and endogenous signals that, together with the intrinsic genetic program, determine plant form. Central to this process are several growth regulators known as plant hormones or phytohormones. Despite decades of study, only recently have receptors for several of these hormones been identified, revealing novel mechanisms for perceiving chemical signals and providing plant biologists with a much clearer picture of...

  15. History of growth hormone therapy

    OpenAIRE

    Vageesh S Ayyar

    2011-01-01

    Although the importance of the pituitary gland for growth was recognized in late 19 th century, Growth hormone (GH) therapy was made available for severely GH-deficient children and adolescents only in late 1950s. Use of GH for other conditions was limited because of the limited supply of human pituitary-derived hormone. With unlimited availability of recombinant human GH (rhGH), the scenario of GH treatment has been changed enormously. Currently there is ever increasing list of indications o...

  16. Stress hormones and physical activity

    OpenAIRE

    Editorial Office

    1991-01-01

    Hormone secretion during physical activity of specific duration and intensity is part of the stress response. In a study to investigate the secretion of ß-endorphin, leucine enkephalin and other recognised stress hormones during physical exercise, blood samples were taken from fourteen (14) healthy, male athletes who competed in a 21 km roadrace. Blood samples were collected before and after completion of the race. This study shows that ß-endorphin/ß-lipotropin, leucine enkephalin, prolact...

  17. Fatigue and cognition - hormonal perspectives

    OpenAIRE

    Möller, Marika

    2013-01-01

    Fatigue is a common complaint and considered a very challenging symptom to cope with in many different medical diseases. The assessment of fatigue is bound up with the problems of both conceptualization and definition. In addition, few studies have investigated suitable neuropsychological tests to examine fatigue and its consequences. This thesis evaluates whether neuropsychological tests can elicit cognitive fatigue. It also investigates whether specific hormones and hormon...

  18. Revisiting Thyroid Hormones in Schizophrenia

    OpenAIRE

    Nadine Correia Santos; Patrício Costa; Dina Ruano; António Macedo; Maria João Soares; José Valente; Ana Telma Pereira; Maria Helena Azevedo; Joana Almeida Palha

    2012-01-01

    Thyroid hormones are crucial during development and in the adult brain. Of interest, fluctuations in the levels of thyroid hormones at various times during development and throughout life can impact on psychiatric disease manifestation and response to treatment. Here we review research on thyroid function assessment in schizophrenia, relating interrelations between the pituitary-thyroid axis and major neurosignaling systems involved in schizophrenia’s pathophysiology. These include the ser...

  19. Short Stature and Growth Hormone Deficiency

    OpenAIRE

    Matemi, Sezer

    1994-01-01

    This paper summarizes the importance of measurements of height and weight in normal children and emphasizes the role of growth increments for the diagnosis of short stature Causes of short stature methods for diagnosis of GH hormone deficiency actions of growth hormone treatment of growth hormone deficiency and doses for biosynthetic GH treatment are described Key words: Short Stature Growth Hormone

  20. 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....

  1. Cadmium affects the episodic luteinizing hormone secretion in male rats: possible age-dependent effects.

    Science.gov (United States)

    Lafuente, A; Márquez, N; Piquero, S; Esquifino, A I

    1999-01-11

    Cadmium affects luteinizing hormone (LH) secretion through unknown mechanisms. The present study was undertaken to assess whether chronic exposure to low concentrations of cadmium may affect the episodic secretion of LH and if these effects are age-dependent. Male rats were given cadmium at a dose of 50 ppm in the drinking water, from day 30 to 60 or from day 60 to 90 of life. Age-matched rats with access to cadmium-free water were used as controls. At the end of the treatment, blood samples were collected every 7 min for 3 h, from 10:30 to 13.30 in conscious, freely moving rats. In control animals, mean serum LH levels and pulse duration increased with age (P < or = 0.001), and pulse frequency and the relative amplitude of LH pulses decreased (P < or = 0.001). Cadmium administration, from day 30 to 60 of life, decreased the pulse frequency and mean half-life of the hormone (P < or = 0.05, P < or = 0.01, respectively). However, no changes in any other parameters studied were observed as compared to the control group. When cadmium was administered from day 60 to 90, mean serum LH levels and the duration of LH pulses decreased (P < or = 0.05), whereas the pulse frequency increased (P < or = 0.05). The absolute and relative amplitude of the LH peaks and the mean half-life of the hormone were not changed after cadmium administration from day 60 to 90. These results indicate that low doses of cadmium change the pulsatile secretion of LH in male rats and that the effect of cadmium on episodic LH release was age-dependent. PMID:10048746

  2. Nongenomic actions of thyroid hormone.

    Science.gov (United States)

    Davis, Paul J; Goglia, Fernando; Leonard, Jack L

    2016-02-01

    The nongenomic actions of thyroid hormone begin at receptors in the plasma membrane, mitochondria or cytoplasm. These receptors can share structural homologies with nuclear thyroid hormone receptors (TRs) that mediate transcriptional actions of T3, or have no homologies with TR, such as the plasma membrane receptor on integrin αvβ3. Nongenomic actions initiated at the plasma membrane by T4 via integrin αvβ3 can induce gene expression that affects angiogenesis and cell proliferation, therefore, both nongenomic and genomic effects can overlap in the nucleus. In the cytoplasm, a truncated TRα isoform mediates T4-dependent regulation of intracellular microfilament organization, contributing to cell and tissue structure. p30 TRα1 is another shortened TR isoform found at the plasma membrane that binds T3 and mediates nongenomic hormonal effects in bone cells. T3 and 3,5-diiodo-L-thyronine are important to the complex nongenomic regulation of cellular respiration in mitochondria. Thus, nongenomic actions expand the repertoire of cellular events controlled by thyroid hormone and can modulate TR-dependent nuclear events. Here, we review the experimental approaches required to define nongenomic actions of the hormone, enumerate the known nongenomic effects of the hormone and their molecular basis, and discuss the possible physiological or pathophysiological consequences of these actions. PMID:26668118

  3. Growth Hormone and Endocrinopathies

    International Nuclear Information System (INIS)

    This is an analysis of 39 patients studied at the Yonsei Medical Center from January, 1976 to March 1979. Of these 35 patient were suspected of having hypothalamic insufficiency and subjected to the L-Dopa stimulation test to observe growth hormone secretary function while four acromegaly patient received the glucose loading test and L-Dopa stimulation test. The results are as follows: 1) The basal level of GH in the various disease was as follows: a) The basal level was lower than the control level but was not statistically significant b) In diabetes the mean value tended to higher than the control level but was not significant statistically c) In all four acromegaly patients the GH level was significantly higher than the control level 2) Of 13 patients with diabetes, nine had diabetic retinopathy, and of those nine, six showed increased L-Dopa response. However, of the four non retinopathic DM patients, only one showed increased response to L-Dopa. 3) Two patients out of ten with Sheehan's syndrome responded to L-Dopa stimulation. 4) One Patient of eight with pituitary chromophobe adenoma responded to L-Dopa stimulation. 5) Four acromegaly patients revealed 3 acidophilic adenoma and one chromophobe adenoma histologically. Of patients receiving the L-Dopa stimulation test. Two showed a paradoxical response. Two patients who received the glucose loading test showed suppressed response. 6) Of two craniopharyngioma patients, one showed increased GH response after L-Dopa stimulation. Increased response of GH after L-Dopa stimulation was seen in one two craniopharyngioma patients and also in one of two patients with short structure.

  4. Discrimination ability and reproducibility of a new index reflecting autonomic nervous function based on pulsatile amplitude of photoplethysmography.

    Science.gov (United States)

    Kano, Yusuke; Yoshizawa, Makoto; Sugita, Norihiro; Abe, Makoto; Homma, Noriyasu; Tanaka, Akira; Yamauchi, Tsuyoshi; Miura, Hidekazu; Shiraishi, Yasuyuki; Yambe, Tomoyuki

    2014-01-01

    A new physiological index (μ(PA)) is proposed to represent the autonomic nervous system (ANS) function. The index μ(PA) is defined as the natural logarithm of the ratio between two different frequency components of the pulsatile amplitude of the photoplethysmogram (PPG) signal. The discrimination ability and the reproducibility of μ(PA) have been compared with other traditional ANS indices. In the experiment, the electrocardiogram, the PPG and continuous blood pressure were measured in 59 healthy young subjects (age 25.7 ± 6.3) and 86 healthy elderly subjects (age 70.2 ± 4.1) at rest. The discrimination ability and the reproducibility were evaluated by Cohen's d between young and elderly groups and by the interclass correlation coefficient, respectively. The results showed that the elderly subjects were significantly (p<;0.001) lower than young subjects in μ(PA) and a few traditional indices introduced to be compared with μ(PA). Therefore, it suggests that μ(PA) is associated with the decrease in the ANS function accompanied by aging. Moreover, it showed that the discrimination ability and the reproducibility of the proposed index are comparable or larger than those of traditional indices. The proposed index based on the PPG signal will be applied to tele-healthcare systems for monitoring people's health in daily life in combination with the ratio of the standard deviation of the R-R intervals to their average value (CVRR). PMID:25570325

  5. Sensitivity Analysis of Pulsatile Hydromagnetic Biofluid Flow and Heat Transfer with Non Linear Darcy-Forchheimer Drag

    Directory of Open Access Journals (Sweden)

    S. Rawat

    2016-01-01

    Full Text Available In the present paper we examine the pulsatile hydromagnetic flow and heat transfer of a non-Newtonian biofluid through a saturated non-Darcian porous medium channel. The upper plate of the channel is heated and the lower plate is cooled. The Nakamura-Sawada rheological model is employed which provides a higher yield stress than the Casson model. A Darcy-Forchheimer porous medium drag force model is incorporated to simulate blood vessel blockage with deposits in the cardiovascular system. Viscous heating is also included in the energy equation. The governing conservation equations for mass, momentum and energy equation are transformed into a system of nonlinear, coupled ordinary differential equations and these are solved numerically using finite element method. The effect of other important parameters such as magnetohydrodynamic parameter (Nm, Reynolds number (Re, Eckert number (Ec, Darcian parameter (, Forchheimer parameter (NF and Prandtl number on velocity and temperature profiles are studied graphically. Spatial-temporal velocity and temperature profile visualizations are also presented. Numerical results shows that normalized fluid velocity (U increases throughout the channel (-1 < Y < 1 with an increase in Reynolds number, Darcian parameter, steady pressure gradient parameter and rheological parameter; conversely velocity is decreased with the increase in magnetic parameter and Forchheimer quadratic drag parameter. Higher Eckert number (Ec = 3 is also found to have a considerable effect on temperature ( profile. Finite difference numerical computations are also compared with the finite element solutions to verify efficiency and accuracy.

  6. Pulsatile magneto-hydrodynamic blood flows through porous blood vessels using a third grade non-Newtonian fluids model.

    Science.gov (United States)

    Akbarzadeh, Pooria

    2016-04-01

    In this paper, the unsteady pulsatile magneto-hydrodynamic blood flows through porous arteries concerning the influence of externally imposed periodic body acceleration and a periodic pressure gradient are numerically simulated. Blood is taken into account as the third-grade non-Newtonian fluid. Besides the numerical solution, for small Womersley parameter (such as blood flow through arterioles and capillaries), the analytical perturbation method is used to solve the nonlinear governing equations. Consequently, analytical expressions for the velocity profile, wall shear stress, and blood flow rate are obtained. Excellent agreement between the analytical and numerical predictions is evident. Also, the effects of body acceleration, magnetic field, third-grade non-Newtonian parameter, pressure gradient, and porosity on the flow behaviors are examined. Some important conclusions are that, when the Womersley parameter is low, viscous forces tend to dominate the flow, velocity profiles are parabolic in shape, and the center-line velocity oscillates in phase with the driving pressure gradient. In addition, by increasing the pressure gradient, the mean value of the velocity profile increases and the amplitude of the velocity remains constant. Also, when non-Newtonian effect increases, the amplitude of the velocity profile. PMID:26792174

  7. Polymeric coatings for a multiple-unit pulsatile delivery system: preliminary study on free and applied films.

    Science.gov (United States)

    Maroni, Alessandra; Del Curto, Maria Dorly; Cerea, Matteo; Zema, Lucia; Foppoli, Anastasia; Gazzaniga, Andrea

    2013-01-20

    In order to adapt a previously described swellable/erodible pulsatile delivery system to a multiple-unit configuration, insoluble films with adequate permeability and flexibility were proposed for application to its functional hydroxypropyl methylcellulose (HPMC) layer. By slowing down the penetration of water into the system, such films would be expected to improve the relevant effectiveness in delaying the onset of release without possibly impacting on the mechanism involved. Free films of Eudragit(®)NE containing differing amounts (10-20%) of a superdisintegrant, i.e. Explotab(®)V17, Ac-Di-Sol(®), Kollidon(®)CL or Kollidon(®)CL-M, were prepared by spraying technique and evaluated for hydration, permeability and tensile properties. The hydration and permeability characteristics were enhanced by the addition of the superdisintegrants, generally as a function of their concentration. Explotab(®)V17 was shown particularly useful to increase the film permeability. Moreover, it exerted a minor impact on the advantageous tensile properties of the acrylic polymer, especially in the wet state. Based on these results and on a preliminary release study performed with two-layer devices, the Eudragit(®)NE film with Explotab(®)V17 at the highest investigated percentage was identified as a potential formulation candidate for being applied to HPMC-coated cores thus allowing the onset of release to effectively be delayed by coatings of reduced thickness. PMID:22688248

  8. Gastroretentive Pulsatile Release Tablets of Lercanidipine HCl: Development, Statistical Optimization, and In Vitro and In Vivo Evaluation

    Directory of Open Access Journals (Sweden)

    Gagganapalli Santhoshi Reddy

    2014-01-01

    Full Text Available The present study was aimed at the development of gastroretentive floating pulsatile release tablets (FPRTs of lercanidipine HCl to enhance the bioavailability and treat early morning surge in blood pressure. Immediate release core tablets containing lercanidipine HCl were prepared and optimized core tablets were compression-coated using buoyant layer containing polyethylene oxide (PEO WSR coagulant, sodium bicarbonate, and directly compressible lactose. FPRTs were evaluated for various in vitro physicochemical parameters, drug-excipient compatibility, buoyancy, swelling, and release studies. The optimized FPRTs were tested in vivo in New Zealand white rabbits for buoyancy and pharmacokinetics. DoE optimization of data revealed FPRTs containing PEO (20% w/w with coat weight 480 mg were promising systems exhibiting good floating behavior and lag time in drug release. Abdominal X-ray imaging of rabbits after oral administration of the tablets, confirmed the floating behavior and lag time. A quadratic model was suggested for release at 7th and 12th h and a linear model was suggested for release lag time. The FPRT formulation improved pharmacokinetic parameters compared to immediate release tablet formulation in terms of extent of absorption in rabbits. As the formulation showed delay in drug release both in vitro and in vivo, nighttime administration could be beneficial to reduce the cardiovascular complications due to early morning surge in blood pressure.

  9. Zumbido pulsátil: tratamento com clonazepan e propranolol Pulsatile tinnitus: treatment with clonazepam and propranolol

    Directory of Open Access Journals (Sweden)

    Sergio Albertino

    2005-02-01

    Full Text Available O zumbido pulsátil sincrônico com os batimentos cardíacos é pouco freqüente, sendo de etiologia tanto vascular arterial (malformações, fístulas artério-venosas ou venosa (anormalidades do bulbo jugular, tumor glômico jugular ou timpânico. A identificação precoce da etiologia é essencial para que a terapêutica adequada possa ser instituída. A angioressonância possibilita a identificação de alterações vasculares com maior precisão. Relatamos um caso onde, após o diagnóstico de uma alteração vascular arterial, foi instituído o tratamento com propranolol e clonazepam, com melhora da sintomatologia.Pulsatile tinnitus synchronous with heartbeat is rare and normally has vascular origin: arterial (malformation, arterial anatomical variation or venous (aberrant jugular bulb, glomus tumors, tympanic glomus tumor. Early etiology identification is essential for appropriate treatment to be established. Magnetic angioresonance makes the vascular identification possible and precise. We report a case of arterial anatomical variation in which the treatment was propranolol and clonazepam, showing tinnitus improvement.

  10. Fluid Dynamic Characterization of a Polymeric Heart Valve Prototype (Poli-Valve) tested under Continuous and Pulsatile Flow Conditions

    Science.gov (United States)

    De Gaetano, Francesco; Serrani, Marta; Bagnoli, Paola; Brubert, Jacob; Stasiak, Joanna; Moggridge, Geoff D.; Costantino, Maria Laura

    2016-01-01

    Introduction Only mechanical and biological heart valve prostheses are currently commercially available. The former show longer durability but require anticoagulant therapy, the latter display better fluid dynamic behaviour but do not have adequate durability. New Polymeric Heart Valves (PHVs) could potentially combine the haemodynamic properties of biological valves with the durability of mechanical valves. This work presents a hydrodynamic evaluation of two groups of newly developed supra-annular tri-leaflet prosthetic heart valves made from styrenic block copolymers (SBC): Poli-Valves. Methods Two types of Poli-Valves made of SBC differing in polystyrene fraction content were tested under continuous and pulsatile flow conditions as prescribed by ISO 5840 Standard. An ad - hoc designed pulse duplicator allowed the valve prototypes to be tested at different flow rates and frequencies. Pressure and flow were recorded; pressure drops, effective orifice area (EOA), and regurgitant volume were computed to assess the valve’s behaviour. Results Both types Poli-Valves met the minimum requirements in terms of regurgitation and EOA as specified by ISO 5840 Standard. Results were compared with five mechanical heart valves (MHVs) and five tissue heart valves (THVs), currently available on the market. Conclusion Based on these results, polymeric heart valves based on styrenic block copolymers, as Poli-Valves are, can be considered as promising alternative for heart valve replacement in near future. PMID:26689146

  11. High-frequency photoacoustic imaging of erythrocyte aggregation and oxygen saturation: probing hemodynamic relations under pulsatile blood flow

    Science.gov (United States)

    Bok, Tae-Hoon; Hysi, Eno; Kolios, Michael C.

    2015-03-01

    In this paper, we investigate the feasibility of high-frequency photoacoustic (PA) imaging to study the shear rate dependent relationship between red blood cell (RBC) aggregation and oxygen saturation (SO2) in a simulated blood flow system. The PA signal amplitude increased during the formation of aggregates and cyclically varied at intervals corresponding to the beat rate (30, 60, 120, 180 and 240 bpm) for all optical wavelengths of illumination (750 and 850 nm).The SO2 also cyclically varied in phase with the PA signal amplitude for all beat rates. In addition, the mean blood flow velocity cyclically varied at the same interval of beat rate, and the shear rate (i.e. the radial gradient of flow velocity) also cyclically varied. On the other hand, the phase of the cyclic variation in the shear rate was reversed compared to that in the PA signal amplitude. This study indicates that RBC aggregation induced by periodic changes in the shear rate can be correlated with the SO2 under pulsatile blood flow. Furthermore, PA imaging of flowing blood may be capable of providing a new biomarker for the clinical application in terms of monitoring blood viscosity, oxygen delivery and their correlation.

  12. Thyroid Hormone Deiodinases and Cancer

    Directory of Open Access Journals (Sweden)

    Antonio eBianco

    2012-06-01

    Full Text Available Deiodinases constitute a group of thioredoxin-containing selenoenzymes that play an important function in thyroid hormone homeostasis and control of thyroid hormone action. There are three known deiodinases: D1 and D2 activate the pro-hormone thyroxine (T4 to T3, the most active form of thyroid hormone, while D3 inactivates thyroid hormone and terminates T3 action. A number of studies indicate that deiodinase expression is altered in several types of cancers, suggesting that (i they may represent a useful cancer marker and/or (ii could play a role in modulating cell proliferation - in different settings thyroid hormone modulates cell proliferation. For example, although D2 is minimally expressed in human and rodent skeletal muscle, its expression level in rhabdomyosarcoma (RMS-13 cells is 3-4 fold higher. In basal cell carcinoma (BCC cells, sonic hedgehog (Shh-induced cell proliferation is accompanied by induction of D3 and inactivation of D2. Interestingly a 5-fold reduction in the growth of BCC in nude mice was observed if D3 expression was knocked down. A decrease in D1 activity has been described in renal clear cell carcinoma, primary liver cancer, lung cancer, and some pituitary tumors, while in breast cancer cells and tissue there is an increase in D1 activity. Furthermore D1 mRNA and activity were found to be decreased in papillary thyroid cancer while D1 and D2 activities were significantly higher in follicular thyroid cancer tissue, in follicular adenoma and in anaplastic thyroid cancer. It is conceivable that understanding how deiodinase dysregulation in tumor cells affect thyroid hormone signaling and possibly interfere with tumor progression could lead to new antineoplastic approaches.

  13. Alternatives of menopausal hormone therapy

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    Kutlešić Ranko M.

    2016-01-01

    Full Text Available Introduction. It has been generally accepted that the benefits of menopausal hormone therapy outweigh the risks, but there are still some concerns about the administration of menopausal hormone therapy, which has introduced alternative treatments. Pharmacological Alternatives. Central alpha-2 agonist clonidine is only marginally more effective than placebo, and significantly less effective than estrogen. Antiepileptic drug gabapentin reduces hot flashes; however, it is less effective than estrogen. Selective serotonin reuptake inhibitors (paroxetine and fluoxetine and selective noradrenaline reuptake inhibitors (venlafaxine reduce vasomotor symptoms and improve depression, anxiety and sleep. Results of studies about dehydroepiandrosterone effects on menopausal symptoms are inconsistent and additional investigations are needed. Non-Pharmacological Alternatives. Stellatum ganglion blockade is a successful treatment for reducing vasomotor symptoms in patients with contraindications for menopausal hormone therapy. Efficacy of acupuncture, homeopathy and reflexology should be proved by adequate studies. Phytoestrogens could reduce vasomotor symptoms but to a lesser extent than conventional menopausal hormone therapy. However, they have not been proved yet to provide cardiovascular protection and prevention of osteoporosis, nor they could be recommended instead of traditional menopausal hormone therapy. There is a concern about their undesirable effects. Adequate diet, unchanging body weight within ideal values and adequate physical activities have beneficial long-term effects, first of all on preservation of bone density. Alternatives for Atrophic Changes of Vaginal Epithelium. Menopausal symptoms resulting from vaginal atrophy could be resolved by use of hydrophilic preparations, lubricants and topical lidocaine cream or 4% lidocaine water solution for dyspareunia. Conclusion. If there are contrain­dications to menopausal hormone therapy or

  14. Is dehydroepiandrosterone a hormone?

    Science.gov (United States)

    Labrie, F; Luu-The, V; Bélanger, A; Lin, S-X; Simard, J; Pelletier, G; Labrie, C

    2005-11-01

    Dehydroepiandrosterone (DHEA) is not a hormone but it is a very important prohormone secreted in large amounts by the adrenals in humans and other primates, but not in lower species. It is secreted in larger quantities than cortisol and is present in the blood at concentrations only second to cholesterol. All the enzymes required to transform DHEA into androgens and/or estrogens are expressed in a cell-specific manner in a large series of peripheral target tissues, thus permitting all androgen-sensitive and estrogen-sensitive tissues to make locally and control the intracellular levels of sex steroids according to local needs. This new field of endocrinology has been called intracrinology. In women, after menopause, all estrogens and almost all androgens are made locally in peripheral tissues from DHEA which indirectly exerts effects, among others, on bone formation, adiposity, muscle, insulin and glucose metabolism, skin, libido and well-being. In men, where the secretion of androgens by the testicles continues for life, the contribution of DHEA to androgens has been best evaluated in the prostate where about 50% of androgens are made locally from DHEA. Such knowledge has led to the development of combined androgen blockade (CAB), a treatment which adds a pure anti-androgen to medical (GnRH agonist) or surgical castration in order to block the access of the androgens made locally to the androgen receptor. In fact, CAB has been the first treatment demonstrated to prolong life in advanced prostate cancer while recent data indicate that it can permit long-term control and probably cure in at least 90% of cases of localized prostate cancer. The new field of intracrinology or local formation of sex steroids from DHEA in target tissues has permitted major advances in the treatment of the two most frequent cancers, namely breast and prostate cancer, while its potential use as a physiological HRT could well provide a physiological balance of androgens and estrogens, thus

  15. Presence and concentration of 17 hormones in human placenta processed for encapsulation and consumption.

    Science.gov (United States)

    Young, Sharon M; Gryder, Laura K; Zava, David; Kimball, David W; Benyshek, Daniel C

    2016-07-01

    Human maternal placentophagy is a rare but growing practice in several industrialized countries among postpartum mothers seeking a variety of purported health benefits attributed to the practice. These postpartum mothers typically consume their placenta as a processed, encapsulated supplement. To determine whether free (unconjugated) steroid hormones and melatonin in placenta can survive the encapsulation process (namely steaming and dehydration), we analyzed 28 placenta samples processed for encapsulation using liquid chromatography tandem-mass spectrometry (LC-MS/MS) to evaluate the concentration of 17 hormones. The results revealed detectable concentrations for 16 of the hormones analyzed, some in concentrations that could conceivably yield physiological effects. PMID:27324105

  16. 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 of...... 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...

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

    International Nuclear Information System (INIS)

    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.)

  18. RELATIONSHIP BETWEEN PROLACTIN HORMONE LEVEL, MOLTING AND DUCK EGG PRODUCTION

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  20. Stress hormones and physical activity

    Directory of Open Access Journals (Sweden)

    Editorial Office

    1991-07-01

    Full Text Available Hormone secretion during physical activity of specific duration and intensity is part of the stress response. In a study to investigate the secretion of ß-endorphin, leucine enkephalin and other recognised stress hormones during physical exercise, blood samples were taken from fourteen (14 healthy, male athletes who competed in a 21 km roadrace. Blood samples were collected before and after completion of the race. This study shows that ß-endorphin/ß-lipotropin, leucine enkephalin, prolactin, and melatonin may be classified as stress hormones in physical activity of duration 80 to 120 minutes and intensity exceeding 75%-V0₂max. Widespread intra-individual variation in serum cortisol concentrations prevent definite conclusion. The un­expected increase in serum testosterone levels warrants further research.

  1. The interaction of growth hormone releasing hormone with other hypothalamic hormones on the release of anterior pituitary hormones.

    Science.gov (United States)

    Looij, B J; Nieuwenhuijzen Kruseman, A C; Mudde, A H; Frölich, M; Piaditis, G P; Hodgkinson, S C; McLean, C; Grossman, A; Coy, D H; Rees, L H

    1986-02-01

    To determine whether the 29 amino-acid fragment of growth hormone releasing hormone (GHRH) can be combined with other hypothalamic releasing hormones in a single test of anterior pituitary reserve, the responses of anterior pituitary hormones to combinations of an i.v. bolus of GHRH(1-29)NH2 or saline with an i.v. bolus of either LH releasing hormone (LHRH) plus TRH, ovine CRH(oCRH) or saline were studied. Each infusion of GHRH(1-29)NH2 resulted in a rapid increment of the plasma GH value. Infusion of GHRH(1-29)NH2 also caused a small and transient rise in plasma PRL, but no change in the integrated PRL response. The combination of GHRH(1-29)NH2 with LHRH plus TRH caused a larger increment of peak and integrated plasma TSH levels than LHRH plus TRH alone. GHRH(1-29)NH2 did not affect the release of other anterior pituitary hormones after infusion with oCRH or LHRH plus TRH. Because of the finding of potentiation of the TSH-releasing activity of LHRH plus TRH by GHRH(1-29)NH2, the study was extended to the investigation of TSH release after infusion of TRH in combination with either GHRH(1-29)NH2 or GHRH(1-40). In this study the combination of TRH with both GHRH preparations also caused a larger increment of the peak and integrated plasma TSH levels than TRH alone. It is concluded that GHRH(1-29)NH2 possesses moderate PRL-releasing activity apart from GH-releasing activity. In addition, GHRH potentiates the TSH-releasing activity of TRH.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2871949

  2. Hormonal evaluation in erectile dysfunction

    Directory of Open Access Journals (Sweden)

    Selahattin Çalışkan

    2012-03-01

    Full Text Available Objective: Erectile dysfunction (ED is defined as the inability to achieve and maintain an erection sufficient to permit satisfactory sexual intercourse. In this study, we evaluated the relationship between ED and hormonal abnormalities. Material and methods: We evaluated 178 patients between the ages of 25 and 85 years old. Medical histories and details were collected, and the IIEF question test was completed by all patients. After the basic evaluation, serum total testosterone, thyroid stimulating hormone (TSH, prolactin, follicle stimulating hormone (FSH and luteinizing hormone (LH levels were measured.Results: The mean age of the patients and IIEF scores were 50.5±12.3 and 12.8±6.13, respectively. The mean testosterone, prolactin, TSH, LH and FSH were 426±152 ng/dL, 15.8±45.6 ng/mL, 1.56±1.2 micro IU/mL, 5.5±4.3 m IU/mL and 7.7±6.9 m IU/mL, respectively. Two patients had abnormal TSH levels, and 27 patients had abnormal LH levels. Abnormal FSH levels were detected in 6 patients. Eight patients had abnormal testosterone levels, and twenty had abnormal prolactin levels.Conclusion: ED is an illness that affects older men, and multiple factors cause this illness. Hormonal abnormalities are one of these factors that can be corrected. When appropriate, hormone levels should be measured and treated in patients who present with ED.

  3. Hormonal interaction in diabetic pregnancy

    International Nuclear Information System (INIS)

    Serum glucose, human placental lactogen (HPL), prolactin (PRL), estradiol (E2), progesterone (P), cortisol and human growth hormone (HGH) were determined in nondiabetic (19 cases) and diabetic (19 cases) pregnant women during the 32nd and 36th week of gestation. Significant elevation of HPL, PRL, HGH and cortisol was found in the diabetic pregnant women during the 32nd week while E2 and P were not significantly changed from the corresponding levels in the nondiabetic group. One can conclude that the changes in the hormonal pattern during gestation may induce carbohydrate intolerance observed in diabetic pregnancies. (author)

  4. Hormonal interaction in diabetic pregnancy

    Energy Technology Data Exchange (ETDEWEB)

    Hafiez, A.R.A.; Abdel-Hafez, M.A.; Osman, E.A. (Cairo Univ. (Egypt)); Ibrahim, M.S. (Al-Azhar Univ., Cairo (Egypt))

    1984-08-01

    Serum glucose, human placental lactogen (HPL), prolactin (PRL), estradiol (E/sub 2/), progesterone (P), cortisol and human growth hormone (HGH) were determined in nondiabetic (19 cases) and diabetic (19 cases) pregnant women during the 32nd and 36th week of gestation. Significant elevation of HPL, PRL, HGH and cortisol was found in the diabetic pregnant women during the 32nd week while E/sub 2/ and P were not significantly changed from the corresponding levels in the nondiabetic group. One can conclude that the changes in the hormonal pattern during gestation may induce carbohydrate intolerance observed in diabetic pregnancies.

  5. Percentage of peak-to-peak pulsatility of portal blood flow can predict right-sided congestive heart failure

    Institute of Scientific and Technical Information of China (English)

    Jui-Ting Hu; Sien-Sing Yang; Yun-Chih Lai; Cheng-Yen Shih; Cheng-Wen Chang

    2003-01-01

    AIM: To study the change of portal blood flow for the prediction of the status of right-sided heart failure by using non-invasive way.METHODS: We studied 20 patients with rheumatic and atherosclerotic heart diseases. All the patients had constant systemic blood pressure and body weight 1 week prior to the study. Cardiac index (CI), left ventricular end-diastolic pressure (LVEDP), mean aortic pressure (AOP), pulmonary wedge pressure (PWP), mean pulmonary arterial pressure (PAP), mean right atrial pressure (RAP), right ventricular end-diastolic pressure (RVEDP) were recorded during cardiac catheterization. Ten patients with RAP<10 mmHg were classified as Group 1. The remaining 10 patients with RAP ≥ 10 mmHg were classified as Group 2. Portal blood velocity profiles were studied using an ultrasonic Doppler within 12h after cardiac catheterization.RESULTS: CI, AOP, and LVEDP had no difference between two groups. Patients in Group 1 had normal PWP (14.6±7.3mmHg), PAP (25.0±8.2 mmHg), RAP (4.7±2.4 mmHg), and RVEDP (6.4±2.7 mmHg). Patients in Group 2 had increased PWP (29.9±9.3 mmHg), PAP (46.3±13.2 mmHg), RAP (17.5±5.7 mmHg), and RVEDP (18.3±5.6 mmHg) (P<0.001).Mean values of maximum portal blood velocity (Vmax), mean portal blood velocity (Vmean), cross-sectional area (Area)and portal blood flow volume (PBF) had no difference between 2 groups. All the patients in Group 1 had a continuous antegrade portal flow with a mean percentage of peak-topeak pulsatility (PP) 27.0±8.9 % (range: 17-40 %). All the patients in Group 2 had pulsatile portal flow with a mean PP 86.6±45.6 (range: 43-194 %). One patient had a transient stagnant and three patients had a transient hepatofugal portal flow, which occurred mainly during the ventricular systole. Vmax, Vmean and PBF had a positive correlation with CO (P<0.001) but not with AOP, LVEDP, PWP, PAP,RAP, and RVEDP.PP showed a good correlation (P<0.001)with PWP, PAP, RAP, and RVEDP but not with CI, AOP, and LVEDP. All

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

    Directory of Open Access Journals (Sweden)

    ErikHrabovszky

    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.

  7. Pilot study of adrenal steroid hormones in hair as an indicator of chronic mental and physical stress

    Science.gov (United States)

    Ullmann, E.; Barthel, A; Petrowski, K.; Stalder, T.; Kirschbaum, C.; Bornstein, S. R.

    2016-01-01

    Currently, the quantitative analysis of moderators affecting the function of the hypothalamus-pituitary-adrenal (HPA)-axis in health and sickness is still unreliable. This is, in particular, due to physiological factors such as pulsatile ultradian and circadian glucocorticoid secretion as well as to methodological limitations of the current techniques for steroid hormone determination. Based on this background, the determination of long-term hair steroid concentrations is an important methodological improvement allowing for the quantitative analysis of chronic HPA axis-activation. In order to determine the relationship between chronic mental and physical stress and a chronic activation of the HPA axis, we performed a cross-sectional pilot-study with 40 healthy students and examined the relationships between physical activity, mental burden(s), subjective stress perceptions, depressiveness, anxiety, physical complaints, sense of coherence, resilience, and the long-term integrated steroid hormone levels in hair. The results showed that the concentrations of cortisol, cortisone, and dehydroepiandrosterone in hair were significantly correlated to mental (p = 0.034) and physical stress (p = 0.001) as well as to subjective stress perception (p = 0.006). We conclude that steroid concentrations in hair are decisive predictors for an increase in the long-term-HPA axis activity. Moreover, this biomarker is suitable for capturing the stresslevel after burdening events and physical activity. PMID:27174654

  8. Pilot study of adrenal steroid hormones in hair as an indicator of chronic mental and physical stress.

    Science.gov (United States)

    Ullmann, E; Barthel, A; Petrowski, K; Stalder, T; Kirschbaum, C; Bornstein, S R

    2016-01-01

    Currently, the quantitative analysis of moderators affecting the function of the hypothalamus-pituitary-adrenal (HPA)-axis in health and sickness is still unreliable. This is, in particular, due to physiological factors such as pulsatile ultradian and circadian glucocorticoid secretion as well as to methodological limitations of the current techniques for steroid hormone determination. Based on this background, the determination of long-term hair steroid concentrations is an important methodological improvement allowing for the quantitative analysis of chronic HPA axis-activation. In order to determine the relationship between chronic mental and physical stress and a chronic activation of the HPA axis, we performed a cross-sectional pilot-study with 40 healthy students and examined the relationships between physical activity, mental burden(s), subjective stress perceptions, depressiveness, anxiety, physical complaints, sense of coherence, resilience, and the long-term integrated steroid hormone levels in hair. The results showed that the concentrations of cortisol, cortisone, and dehydroepiandrosterone in hair were significantly correlated to mental (p = 0.034) and physical stress (p = 0.001) as well as to subjective stress perception (p = 0.006). We conclude that steroid concentrations in hair are decisive predictors for an increase in the long-term-HPA axis activity. Moreover, this biomarker is suitable for capturing the stresslevel after burdening events and physical activity. PMID:27174654

  9. Association between idiopathic intracranial hypertension and sigmoid sinus dehiscence/diverticulum with pulsatile tinnitus: a retrospective imaging study

    Energy Technology Data Exchange (ETDEWEB)

    Zhaohui, Liu; Qing, Li [Capital Medical University, Beijing Tongren Hospital, Department of Radiology, Beijing (China); Cheng, Dong; Xiao, Wang; Xiaoyi, Han; Pengfei, Zhao; Han, Lv; Zhenchang, Wang [Capital Medical University, Beijing Friendship Hospital, Department of Radiology, Beijing (China)

    2015-07-15

    The mechanism of occurrence of sigmoid sinus dehiscence/diverticulum (SSDD) in pulsatile tinnitus (PT) patients remains under debate. Its association with idiopathic intracranial hypertension (IIH) lacks evidence, which is important for therapeutic planning and improving the clinical outcome. This study aimed to evaluate the association between SSDD and IIH by comparing the prevalence of several established imaging features of IIH between PT patients with SSDD and healthy volunteers. Thirty-three unilateral PT patients with SSDD identified on CT images and 33 age- and sex-matched healthy volunteers underwent T1-weighted volumetric magnetic resonance imaging (MRI). The optic nerve, pituitary gland, transverse sinus, and ventricles were assessed. The prevalence of established IIH imaging features was compared between the two groups. Furthermore, the PT patients were divided into two subgroups: PT patients with dehiscence only and PT patients with diverticulum. The same statistical analysis was performed on each pathophysiologic entity respectively. The PT patients with SSDD showed a significantly higher prevalence of empty sella (P < 0.001), flattened posterior sclera (P = 0.001), vertical tortuosity of the optic nerve (P = 0.001), protrusion of the optic nerve (P = 0.006), transverse sinus stenosis (P = 0.011), and distension of the optic nerve sheath (P = 0.000). There were no significant differences between the PT and control groups in the maximum widths of the third and fourth ventricles and the lateral ventricle size. In contrast to controls, the imaging findings persisted in both of pathophysiologic entities, except for transverse sinus stenosis. Several IIH imaging features occur more frequently in PT patients with SSDD than in healthy individuals, which suggests a potential correlation between SSDD with PT and IIH. (orig.)

  10. Association between idiopathic intracranial hypertension and sigmoid sinus dehiscence/diverticulum with pulsatile tinnitus: a retrospective imaging study

    International Nuclear Information System (INIS)

    The mechanism of occurrence of sigmoid sinus dehiscence/diverticulum (SSDD) in pulsatile tinnitus (PT) patients remains under debate. Its association with idiopathic intracranial hypertension (IIH) lacks evidence, which is important for therapeutic planning and improving the clinical outcome. This study aimed to evaluate the association between SSDD and IIH by comparing the prevalence of several established imaging features of IIH between PT patients with SSDD and healthy volunteers. Thirty-three unilateral PT patients with SSDD identified on CT images and 33 age- and sex-matched healthy volunteers underwent T1-weighted volumetric magnetic resonance imaging (MRI). The optic nerve, pituitary gland, transverse sinus, and ventricles were assessed. The prevalence of established IIH imaging features was compared between the two groups. Furthermore, the PT patients were divided into two subgroups: PT patients with dehiscence only and PT patients with diverticulum. The same statistical analysis was performed on each pathophysiologic entity respectively. The PT patients with SSDD showed a significantly higher prevalence of empty sella (P < 0.001), flattened posterior sclera (P = 0.001), vertical tortuosity of the optic nerve (P = 0.001), protrusion of the optic nerve (P = 0.006), transverse sinus stenosis (P = 0.011), and distension of the optic nerve sheath (P = 0.000). There were no significant differences between the PT and control groups in the maximum widths of the third and fourth ventricles and the lateral ventricle size. In contrast to controls, the imaging findings persisted in both of pathophysiologic entities, except for transverse sinus stenosis. Several IIH imaging features occur more frequently in PT patients with SSDD than in healthy individuals, which suggests a potential correlation between SSDD with PT and IIH. (orig.)

  11. Pulsatile blood flow in human bone assessed by laser-Doppler flowmetry and the interpretation of photoplethysmographic signals

    International Nuclear Information System (INIS)

    Human bone blood flow, mean blood speed and the number of moving red blood cells were assessed (in arbitrary units), as a function of time, during one cardiac cycle. The measurements were obtained non-invasively on five volunteers by laser-Doppler flowmetry at large interoptode spacing. The investigated bones included: patella, clavicle, tibial diaphysis and tibial malleolus. As hypothesized, we found that in all bones the number of moving cells remains constant during cardiac cycles. Therefore, we concluded that the pulsatile nature of blood flow must be completely determined by the mean blood speed and not by changes in blood volume (vessels dilation). Based on these results, it is finally demonstrated using a mathematical model (derived from the radiative transport theory) that photoplethysmographic (PPG) pulsations observed by others in the literature, cannot be generated by oscillations in blood oxygen saturation, which is physiologically linked to blood speed. In fact, possible oxygen saturation changes during pulsations decrease the amplitude of PPG pulsations due to specific features of the PPG light source. It is shown that a variation in blood oxygen saturation of 3% may induce a negative change of ∼1% in the PPG signal. It is concluded that PPG pulsations are determined by periodic ‘positive’ changes of the reduced scattering coefficient of the tissue and/or the absorption coefficient at constant blood volume. No explicit experimental PPG measurements have been performed. As a by-product of this study, an estimation of the arterial pulse wave velocity obtained from the analysis of the blood flow pulsations give a value of 7.8 m s−1 (95% confidence interval of the sample mean distribution: [6.7, 9.5] m s−1), which is perfectly compatible with data in the literature. We hope that this note will contribute to a better understanding of PPG signals and to further develop the domain of the vascular physiology of human bone. (note)

  12. Superior semicircular canal dehiscence in relation to the superior petrosal sinus: a potential cause of pulsatile tinnitus

    International Nuclear Information System (INIS)

    Aim: To examine the association between superior semicircular canal dehiscence (SSCD) and pulsatile tinnitus (PT). Materials and methods: Two SSCD groups included 408 unilateral persistent PT patients, and 511 controls undergoing head and neck dual-phase contrast-enhanced computed tomography (DP-CECT) for reasons other than PT. The prevalence of type I (no the superior petrosal sinus running through the dehiscence) and type II (superior semicircular canal dehiscence in relation to the superior petrosal sinus) SSCD was analysed using chi-square test. Results: SSCD was identified in 5.1% (21/408) of PT ears, significantly different from 2% (8/408) of non-PT ears and 0.7% (7/1022) of controls. There was no significant difference in SSCD prevalence between non-PT ears in the PT group and controls. In the PT group, 15/21 ears were type II SSCD; 6/21 ears were type I. Fifteen combined non-PT and control ears with SSCD included two type II and 13 type I SSCD. The prevalence of type II SSCD in PT ears was significantly higher than that of non-PT ears in both groups, and the prevalence of type I SSCD in PT ears was similar to that of non-PT ears in both groups. Conclusion: Compared with type I SSCD, there may be a causal relationship between type II SSCD and PT. -- Highlights: •The prevalence of type II SSCD in PT ears was significantly higher than that in non-PT ears in both the PT group and controls. •The prevalence of type I SSCD was similar among the PT ears and non-PT ears. •The superior petrosal sinus running through the dehiscence may be essential for SSCD to induce PT. •Venous phase CT images with bone window settings is the modality method to differentiate type II from type I SSCD

  13. Investigation of suspected growth hormone deficiency

    OpenAIRE

    Milner, R. D. G.; Burns, E C

    1982-01-01

    This paper describes views of the Health Services Human Growth Hormone Committee on how a child suspected of growth hormone deficiency should be investigated in a district general hospital or in a regional growth centre.

  14. Hormone May Be Linked to Teenage Obesity

    Science.gov (United States)

    ... 159014.html Hormone May Be Linked to Teenage Obesity Researchers suspect low levels of spexin might play ... reduced levels of this hormone in adults with obesity. Overall, our findings suggest spexin may play a ...

  15. Hormone May Be Linked to Teenage Obesity

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_159014.html Hormone May Be Linked to Teenage Obesity Researchers suspect ... may have lower levels of a weight-regulating hormone than normal-weight teens, a new study says. " ...

  16. 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...... 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 posttranslational...... 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 outside the gut, some only in extraintestinal endocrine cells and cerebral or peripheral neurons but others also in...

  17. Hormonal contraceptives and venous thrombosis

    NARCIS (Netherlands)

    Stegeman, Berendina Hendrika (Bernardine)

    2013-01-01

    Oral contraceptive use is associated with venous thrombosis. However, the mechanism behind this remains unclear. The aim of this thesis was to evaluate genetic variation in the first-pass metabolism of contraceptives, to identify the clinical implications of hormonal contraceptive use after a thromb

  18. Sex hormone binding globulin phenotypes

    DEFF Research Database (Denmark)

    Cornelisse, M M; Bennett, Patrick; Christiansen, M;

    1994-01-01

    Human sex hormone binding globulin (SHBG) is encoded by a normal and a variant allele. The resulting SHBG phenotypes (the homozygous normal SHBG, the heterozygous SHBG and the homozygous variant SHBG phenotype) can be distinguished by their electrophoretic patterns. We developed a novel detection...

  19. Parathyroid hormone and bone healing

    DEFF Research Database (Denmark)

    Ellegaard, M; Jørgensen, N R; Schwarz, P

    2010-01-01

    pharmacological treatments are available. There is therefore an unmet need for medications that can stimulate bone healing. Parathyroid hormone (PTH) is the first bone anabolic drug approved for the treatment of osteoporosis, and intriguingly a number of animal studies suggest that PTH could be beneficial in the...

  20. Control of puberty onset and fertility by gonadotropin-releasing hormone neurons.

    Science.gov (United States)

    Herbison, Allan E

    2016-08-01

    The gonadotropin-releasing hormone (GnRH) neuronal network generates pulse and surge modes of gonadotropin secretion critical for puberty and fertility. The arcuate nucleus kisspeptin neurons that innervate the projections of GnRH neurons in and around their neurosecretory zone are key components of the pulse generator in all mammals. By contrast, kisspeptin neurons located in the preoptic area project to GnRH neuron cell bodies and proximal dendrites and are involved in surge generation in female rodents (and possibly other species). The hypothalamic-pituitary-gonadal axis develops embryonically but, apart from short periods of activation immediately after birth, remains suppressed through a combination of gonadal and non-gonadal mechanisms. At puberty onset, the pulse generator reactivates, probably owing to progressive stimulatory influences on GnRH neurons from glial and neurotransmitter signalling, and the re-emergence of stimulatory arcuate kisspeptin input. In females, the development of pulsatile gonadotropin secretion enables final maturation of the surge generator that ultimately triggers the first ovulation. Representation of the GnRH neuronal network as a series of interlocking functional modules could help conceptualization of its functioning in different species. Insights into pulse and surge generation are expected to aid development of therapeutic strategies ameliorating pubertal disorders and infertility in the clinic. PMID:27199290

  1. Internal Jugular Vein Cross-Sectional Area and Cerebrospinal Fluid Pulsatility in the Aqueduct of Sylvius: A Comparative Study between Healthy Subjects and Multiple Sclerosis Patients

    Science.gov (United States)

    Beggs, Clive B.; Magnano, Christopher; Belov, Pavel; Krawiecki, Jacqueline; Ramasamy, Deepa P.; Hagemeier, Jesper; Zivadinov, Robert

    2016-01-01

    Objectives Constricted cerebral venous outflow has been linked with increased cerebrospinal fluid (CSF) pulsatility in the aqueduct of Sylvius in multiple sclerosis (MS) patients and healthy individuals. This study investigates the relationship between CSF pulsatility and internal jugular vein (IJV) cross-sectional area (CSA) in these two groups, something previously unknown. Methods 65 relapsing-remitting MS patients (50.8% female; mean age = 43.8 years) and 74 healthy controls (HCs) (54.1% female; mean age = 43.9 years) were investigated. CSF flow quantification was performed on cine phase-contrast MRI, while IJV-CSA was calculated using magnetic resonance venography. Statistical analysis involved correlation, and partial least squares correlation analysis (PLSCA). Results PLSCA revealed a significant difference (pC4. Controlling for age and cardiovascular risk factors, statistical trends were identified in HCs between: increased net positive CSF flow (NPF) and increased IJV-CSA at C5-C6 (left: r = 0.374, p = 0.016; right: r = 0.364, p = 0.019) and C4 (left: r = 0.361, p = 0.020); and increased net negative CSF flow and increased left IJV-CSA at C5-C6 (r = -0.348, p = 0.026) and C4 (r = -0.324, p = 0.039), whereas in MS patients a trend was only identified between increased NPF and increased left IJV-CSA at C5-C6 (r = 0.351, p = 0.021). Overall, correlations were weaker in MS patients (p = 0.015). Conclusions In healthy adults, increased CSF pulsatility is associated with increased IJV-CSA in the lower cervix (independent of age and cardiovascular risk factors), suggesting a biomechanical link between the two. This relationship is altered in MS patients. PMID:27135831

  2. The pulsatile motion of a semi-infinite bubble in a channel: flow fields, and transport of an inactive surface-associated contaminant

    Science.gov (United States)

    Zimmer, Maximillian E.; Williams, Harvey A. R.; Gaver, Donald P.

    2005-08-01

    We investigate a theoretical model of the pulsatile motion of a contaminant-doped semi-infinite bubble in a rectangular channel. We examine the fluid mechanical behaviour of the pulsatile bubble, and its influence on the transport of a surface-inactive contaminant (termed surfinactant). This investigation is used to develop a preliminary understanding of surfactant responses during unsteady pulmonary airway reopening. Reopening is modelled as the pulsatile motion of a semi-infinite gas bubble in a horizontal channel of width 2a filled with a Newtonian liquid of viscosity mu and constant surface tension gamma. A modified Langmuir sorption model is assumed, which allows for the creation and respreading of a surface multilayer. The bubble is forced via a time-dependent volume flux Q(t) with mean and oscillatory components (Q_{M} and Q_{omega }, respectively) at frequency omega . The flow behaviour is governed by the dimensionless parameters: Ca_{M} {=} mu Q_{M}/(2agamma ), a steady-state capillary number, which represents the ratio of viscous to surface tension forces; Ca_{Omega } {=} mu Q_{omega }/(2agamma ), an oscillatory forcing magnitude; Omega {=} omega mu a/gamma , a dimensionless frequency that represents the ratio of viscous relaxation to oscillatory-forcing timescales; and A {=} 2Ca_{Omega }/Omega , a dimensionless oscillation amplitude. Our simulations indicate that contaminant deposition and retention in the bubble cap region occurs at moderate frequencies if retrograde bubble motion develops during the oscillation cycle. However, if oscillations are too rapid the ensuing large forward tip velocities cause a net loss of contaminant from the bubble tip. Determination of an optimal oscillation range may be important in reducing ventilator-induced lung injury associated with infant and adult respiratory distress syndromes by increasing surfactant transport to regions of collapsed airways.

  3. Cardiac hypertrophy and thyroid hormone signaling

    OpenAIRE

    Dillmann, Wolfgang

    2009-01-01

    Thyroid hormone exerts a large number of influences on the cardiovascular system. Increased thyroid hormone action increases the force and speed of systolic contraction and the speed of diastolic relaxation and these are largely beneficial effects. Furthermore, thyroid hormone has marked electrophysiological effects increasing heart rate and the propensity for atrial fibrillation and these effects are largely mal-adaptive. In addition, thyroid hormone markedly increases cardiac angiogenesis a...

  4. Cardiac hypertrophy and thyroid hormone signaling

    OpenAIRE

    Dillmann, Wolfgang

    2010-01-01

    Thyroid hormone exerts a large number of influences on the cardiovascular system. Increased thyroid hormone action increases the force and speed of systolic contraction and the speed of diastolic relaxation and these are largely beneficial effects. Furthermore, thyroid hormone has marked electrophysiological effects increasing heart rate and the propensity for atrial fibrillation and these effects are largely mal-adaptive. In addition, thyroid hormone markedly increases cardiac angiogenesis a...

  5. Developing a model of plant hormone interactions

    OpenAIRE

    Wang, Yu Hua; Helen R Irving

    2011-01-01

    Plant growth and development is influenced by mutual interactions among plant hormones. The five classical plant hormones are auxins, cytokinins, gibberellins, abscisic acid and ethylene. They are small diffusible molecules that easily penetrate between cells. In addition, newer classes of plant hormones have been identified such as brassinosteroids, jasmonic acid, salicylic acid and various small proteins or peptides. These hormones also play important roles in the regulation of plant growth...

  6. Endocrine disruptors and thyroid hormone physiology

    OpenAIRE

    Jugan, Mary-Line; Levi, Yves; Blondeau, Jean-Paul

    2010-01-01

    Abstract Endocrine disruptors are man-made chemicals that can disrupt the synthesis, circulating levels, and peripheral action of hormones. The disruption of sex hormones was subject of intensive research, but thyroid hormone synthesis and signaling are now also recognized as important targets of endocrine disruptors. The neurological development of mammals is largely dependent on normal thyroid hormone homeostasis, and it is likely to be particularly sensitive to disruption of the...

  7. A tandem parallel plate analyzer

    International Nuclear Information System (INIS)

    By a new modification of a parallel plate analyzer the second-order focus is obtained in an arbitrary injection angle. This kind of an analyzer with a small injection angle will have an advantage of small operational voltage, compared to the Proca and Green analyzer where the injection angle is 30 degrees. Thus, the newly proposed analyzer will be very useful for the precise energy measurement of high energy particles in MeV range. (author)

  8. "Sex Hormones" in Secondary School Biology Textbooks

    Science.gov (United States)

    Nehm, Ross H.; Young, Rebecca

    2008-01-01

    This study explores the extent to which the term "sex hormone" is used in science textbooks, and whether the use of the term "sex hormone" is associated with pre-empirical concepts of sex dualism, in particular the misconceptions that these so-called "sex hormones" are sex specific and restricted to sex-related physiological functioning. We found…

  9. 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...

  10. The hormonal regulation of life processes in insects (2.) The anti-juvenile hormones (1.)

    International Nuclear Information System (INIS)

    Those compounds that decrease either the level or activity of natural endogenous juvenile hormones in insects are called anti-juvenile hormones (AJH). The possible effects of anti-juvenile hormones are manifold: they may inhibit special enzymes or the bindings of juvenile hormones to receptors and transport proteins or may cause the destruction of corpora allata, the sources of juvenile hormones. The most obvious possibility to elicit an anti-juvenile hormone effect lies in the inhibition of enzymes participating in the biosynthesis of juvenile hormones

  11. Etiology of growth hormone deficiency in children and adolescents

    Directory of Open Access Journals (Sweden)

    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.

  12. Melatonin effects on luteinizing hormone in postmenopausal women: a pilot clinical trial NCT00288262

    Directory of Open Access Journals (Sweden)

    Kline Lawrence E

    2006-05-01

    Full Text Available Abstract Background In many mammals, the duration of the nocturnal melatonin elevation regulates seasonal changes in reproductive hormones such as luteinizing hormone (LH. Melatonin's effects on human reproductive endocrinology are uncertain. It is thought that the same hypothalamic pulse generator may both trigger the pulsatile release of GnRH and LH and also cause hot flashes. Thus, if melatonin suppressed this pulse generator in postmenopausal women, it might moderate hot flashes. This clinical trial tested the hypothesis that melatonin could suppress LH and relieve hot flashes. Methods Twenty postmenopausal women troubled by hot flashes underwent one week of baseline observation followed by 4 weeks of a randomized controlled trial of melatonin or matched placebo. The three randomized treatments were melatonin 0.5 mg 2.5–3 hours before bedtime, melatonin 0.5 mg upon morning awakening, or placebo capsules. Twelve of the women were admitted to the GCRC at baseline and at the end of randomized treatment for 24-hour sampling of blood for LH. Morning urine samples were collected twice weekly to measure LH excretion. Subjective responses measured throughout baseline and treatment included sleep and hot flash logs, the CESD and QIDS depression self-ratings, and the SAFTEE physical symptom inventory. Results Urinary LH tended to increase from baseline to the end of treatment. Contrasts among the 3 randomized groups were statistically marginal, but there was relative suppression combining the groups given melatonin as contrasted to the placebo group (p Conclusion The data are consistent with the hypothesis that melatonin suppresses LH in postmenopausal women. An effect related to the duration of nocturnal melatonin elevation is suggested. Effects of melatonin on reproductive endocrinology should be studied further in younger women and in men. Larger studies of melatonin effects on postmenopausal symptoms would be worthwhile.

  13. Thyroid hormone receptors bind to defined regions of the growth hormone and placental lactogen genes.

    OpenAIRE

    Barlow, J W; Voz, M L; Eliard, P H; Mathy-Harter, M; De Nayer, Philippe; Economidis, I V; Belayew, A; Martial, J A; Rousseau, Guy

    1986-01-01

    The intracellular receptor for thyroid hormone is a protein found in chromatin. Since thyroid hormone stimulates transcription of the growth hormone gene through an unknown mechanism, the hypothesis that the thyroid hormone-receptor complex interacts with defined regions of this gene has been investigated in a cell-free system. Nuclear extracts from human lymphoblastoid IM-9 cells containing thyroid hormone receptors were incubated with L-3,5,3'-tri[125I]iodothyronine and calf thymus DNA-cell...

  14. The menopause and hormone replacement therapy: views of women in general practice receiving hormone replacement therapy.

    OpenAIRE

    Roberts, P J

    1991-01-01

    Women's views on the menopause and hormone replacement therapy were explored using a questionnaire given to women attending one general practice who were having hormone replacement therapy under the supervision of their doctor. Sixty four women (67%) responded. Although only 5% of women had requested hormone replacement therapy from their general practitioner the majority of women indicated that they had been helped by hormone replacement therapy. Eight per cent of women were using hormone re...

  15. Growth hormone state after completion of treatment with growth hormone.

    OpenAIRE

    Clayton, P E; Price, D. A.; Shalet, S M

    1987-01-01

    After completion of treatment with growth hormone (GH) 19 patients with isolated 'idiopathic' GH deficiency and 15 with post-irradiation GH deficiency underwent retesting of GH secretion with an insulin tolerance test or an arginine stimulation test, or both. Patients with post-irradiation GH deficiency comprised 13 patients with central nervous system tumours distant from the hypothalamo-pituitary axis and two with acute lymphoblastic leukaemia, who had received cranial or craniospinal irrad...

  16. Effects of EDTA and Sodium Citrate on hormone measurements by fluorometric (FIA and immunofluorometric (IFMA methods

    Directory of Open Access Journals (Sweden)

    Lando Valeria

    2002-05-01

    Full Text Available Abstract Background Measurements of hormonal concentrations by immunoassays using fluorescent tracer substance (Eu3+ are susceptible to the action of chemical agents that may cause alterations in its original structure. Our goal was to verify the effect of two types of anticoagulants in the hormone assays performed by fluorometric (FIA or immunofluorometric (IFMA methods. Methods Blood samples were obtained from 30 outpatients and were drawn in EDTA, sodium citrate, and serum separation Vacutainer®Blood Collection Tubes. Samples were analyzed in automatized equipment AutoDelfia™ (Perkin Elmer Brazil, Wallac, Finland for the following hormones: Luteinizing hormone (LH, Follicle stimulating homone (FSH, prolactin (PRL, growth hormone (GH, Sex hormone binding globulin (SHBG, thyroid stimulating hormone (TSH, insulin, C peptide, total T3, total T4, free T4, estradiol, progesterone, testosterone, and cortisol. Statistical analysis was carried out by Kruskal-Wallis method and Dunn's test. Results No significant differences were seen between samples for LH, FSH, PRL and free T4. Results from GH, TSH, insulin, C peptide, SHBG, total T3, total T4, estradiol, testosterone, cortisol, and progesterone were significant different between serum and EDTA-treated samples groups. Differences were also identified between serum and sodium citrate-treated samples in the analysis for TSH, insulin, total T3, estradiol, testosterone and progesterone. Conclusions We conclude that the hormonal analysis carried through by FIA or IFMA are susceptible to the effects of anticoagulants in the biological material collected that vary depending on the type of assay.

  17. Analysis of Paired Primary-Metastatic Hormone-Receptor Positive Breast Tumors (HRPBC Uncovers Potential Novel Drivers of Hormonal Resistance.

    Directory of Open Access Journals (Sweden)

    Luis Manso

    Full Text Available We sought to identify genetic variants associated with disease relapse and failure to hormonal treatment in hormone-receptor positive breast cancer (HRPBC. We analyzed a series of HRPBC with distant relapse, by sequencing pairs (n = 11 of tumors (primary and metastases at >800X. Comparative genomic hybridization was performed as well. Top hits, based on the frequency of alteration and severity of the changes, were tested in the TCGA series. Genes determining the most parsimonious prognostic signature were studied for their functional role in vitro, by performing cell growth assays in hormonal-deprivation conditions, a setting that mimics treatment with aromatase inhibitors. Severe alterations were recurrently found in 18 genes in the pairs. However, only MYC, DNAH5, CSFR1, EPHA7, ARID1B, and KMT2C preserved an independent prognosis impact and/or showed a significantly different incidence of alterations between relapsed and non-relapsed cases in the TCGA series. The signature composed of MYC, KMT2C, and EPHA7 best discriminated the clinical course, (overall survival 90,7 vs. 144,5 months; p = 0.0001. Having an alteration in any of the genes of the signature implied a hazard ratio of death of 3.25 (p<0.0001, and early relapse during the adjuvant hormonal treatment. The presence of the D348N mutation in KMT2C and/or the T666I mutation in the kinase domain of EPHA7 conferred hormonal resistance in vitro. Novel inactivating mutations in KMT2C and EPHA7, which confer hormonal resistance, are linked to adverse clinical course in HRPBC.

  18. Analysis of Paired Primary-Metastatic Hormone-Receptor Positive Breast Tumors (HRPBC) Uncovers Potential Novel Drivers of Hormonal Resistance.

    Science.gov (United States)

    Manso, Luis; Mourón, Silvana; Tress, Michael; Gómez-López, Gonzalo; Morente, Manuel; Ciruelos, Eva; Rubio-Camarillo, Miriam; Rodriguez-Peralto, Jose Luis; Pujana, Miguel A; Pisano, David G; Quintela-Fandino, Miguel

    2016-01-01

    We sought to identify genetic variants associated with disease relapse and failure to hormonal treatment in hormone-receptor positive breast cancer (HRPBC). We analyzed a series of HRPBC with distant relapse, by sequencing pairs (n = 11) of tumors (primary and metastases) at >800X. Comparative genomic hybridization was performed as well. Top hits, based on the frequency of alteration and severity of the changes, were tested in the TCGA series. Genes determining the most parsimonious prognostic signature were studied for their functional role in vitro, by performing cell growth assays in hormonal-deprivation conditions, a setting that mimics treatment with aromatase inhibitors. Severe alterations were recurrently found in 18 genes in the pairs. However, only MYC, DNAH5, CSFR1, EPHA7, ARID1B, and KMT2C preserved an independent prognosis impact and/or showed a significantly different incidence of alterations between relapsed and non-relapsed cases in the TCGA series. The signature composed of MYC, KMT2C, and EPHA7 best discriminated the clinical course, (overall survival 90,7 vs. 144,5 months; p = 0.0001). Having an alteration in any of the genes of the signature implied a hazard ratio of death of 3.25 (p<0.0001), and early relapse during the adjuvant hormonal treatment. The presence of the D348N mutation in KMT2C and/or the T666I mutation in the kinase domain of EPHA7 conferred hormonal resistance in vitro. Novel inactivating mutations in KMT2C and EPHA7, which confer hormonal resistance, are linked to adverse clinical course in HRPBC. PMID:27195705

  19. Reproductive Hormones and Mood Disorders

    Directory of Open Access Journals (Sweden)

    Sermin Kesebir

    2010-12-01

    Full Text Available During the menstrual cycle, pregnancy and breast-feeding periods, as well as in menopausal and post-menopausal periods, the physiological and psychological processes that change according to the hormonal fluctuations influence every women similarly and each one differently. These physiological processes are controlled by neuroendocrine sequences, of which the hypothalamo-pituitary-adrenal axis and the hypothalamo-pituitary-gonadal axis are the most important ones. The hypothalamo-pituitary-gonadal axis affects mood, anxiety, cognition and pain. The interaction of these hormones with mood and behavior is bidirectional. The differences in phenomenology and epidemiology of mood disorders with regards to gender can be explained with the effects of hormones. All of the periods mentioned above are related with mood disorders at terms of risk factors, disease symptoms, progress of disease and response to treatment. Epidemiologic data supports the relationship between the mood disorders and reproductive processes. The prevalence of major depression increases in women with the menarche and ceases in post- menopausal period. Similarly, the initial symptoms of bipolar disorder begins around the menarche period in 50% of the cases. Despite proper treatment, some female patients with major depression experience recurrence during the premenstrual period of their menstrual cycles. The conformity and change in a woman’s brain during pregnancy is controlled dominantly by the neuroendocrine systems, while it is controlled by the external stimuli actively related to the baby during nursing period. The changes that occur are closely related to postpartum mood disorders. Again, all the changes and suspension of medication during this procedure are risk factors for early depressive and dysphoric situations. Variables of a wide range, from follicle stimulating hormone, melatonin, and sleep to body mass index interact with mood disorders in menopausal and post

  20. Analyses of plasma for metabolic and hormonal changes in rats flown aboard Cosmos 2044

    Science.gov (United States)

    Merrill, Alfred H., Jr.; Wang, Elaine; Mullins, Richard E.; Grindeland, Richard E.; Popova, Irina A.

    1992-01-01

    Plasmas samples from rats flown aboard Cosmos 2044 were analyzed for the levels of key metabolites, electrolytes, enzymes, and hormones. The major differences between the flight group and the synchronous control were elevations in glucose, cholesterol, phosphate, creatinine, blood urea nitrogen, lactate dehydrogenase, and aspartate aminotransferase and decreased levels of thyroxine. Most of these differences were not mimicked by tail suspension of ground-based rats; however, both flight and suspended rats exhibited inhibited testosterone secretion. Corticosterone, immunoreactive growth hormone, and prolactin showed inconsistent differences from the various control groups, suggesting that the levels of these hormones were not due to actual or simulated microgravity.

  1. A mathematical model for LH release in response to continuous and pulsatile exposure of gonadotrophs to GnRH

    Directory of Open Access Journals (Sweden)

    Reed Michael C

    2004-09-01

    Full Text Available Abstract In a previous study, a model was developed to investigate the release of luteinizing hormone (LH from pituitary cells in response to a short pulse of gonadotropin-releasing hormone (GnRH. The model included: binding of GnRH to its receptor (R, dimerization and internalization of the hormone receptor complex, interaction with a G protein, production of inositol 1,4,5-trisphosphate (IP3, release of calcium from the endoplasmic reticulum (ER, entrance of calcium into the cytosol via voltage gated membrane channels, pumping of calcium out of the cytosol via membrane and ER pumps, and release of LH. The extended model, presented in this paper, also includes the following physiologically important phenomena: desensitization of calcium channels; internalization of the dimerized receptors and recycling of some of the internalized receptors; an increase in Gq concentration near the plasma membrane in response to receptor dimerization; and basal rates of synthesis and degradation of the receptors. With suitable choices of the parameters, good agreement with a variety of experimental data of the LH release pattern in response to pulses of various durations, repetition rates, and concentrations of GnRH were obtained. The mathematical model allows us to assess the effects of internalization and desensitization on the shapes and time courses of LH response curves.

  2. Ovarian hormones and drug abuse.

    Science.gov (United States)

    Moran-Santa Maria, Megan M; Flanagan, Julianne; Brady, Kathleen

    2014-11-01

    There are significant gender differences in course, symptomology, and treatment of substance use disorders. In general data from clinical and preclinical studies of substance use disorders suggest that women are more vulnerable than men to the deleterious consequences of drug use at every phase of the addiction process. In addition data from epidemiologic studies suggest that the gender gap in the prevalence of substance use is narrowing particularly among adolescence. Therefore, understanding the role of estrogen and progesterone in mediating responses to drugs of abuse is of critical importance to women's health. In this review we will discuss findings from clinical and preclinical studies of (1) reproductive cycle phase; (2) endogenous ovarian hormones; and (3) hormone replacement on responses to stimulants, nicotine, alcohol, opioids, and marijuana. In addition, we discuss data from recent studies that have advanced our understanding of the neurobiologic mechanisms that interact with estrogen and progesterone to mediate drug-seeking behavior. PMID:25224609

  3. Radioactive labelling of peptidic hormones

    International Nuclear Information System (INIS)

    The labelling of peptidic hormones requires stability, specificity and sensitivity of the label. Introduction of a radioactive atome is one way to satisfy these criteria. Several processes have been described to prepare radioactive TRF: synthesis of the peptide with labelled aminoacids or introduction of the label into the hormone. In that approach, tritium can be substituted in the imidazole ring, via precursors activating the proper carbon. Monoiodo TRF leads essentially to tritium labelling of the 5 positions whereas monoazo TRF allows the preparation of 3H TRF labelled in the 2 positions. Di-substituted TRF leads to labelling into the 2 and 5 carbons. Labelled analogs of TRF can be prepared with labelled iodine; further developments of peptide labelling, will be presented. In particular, the homolytic scission of the C-iodine, bond by photochemical activation. The nascent carbon radical can be stabilized by a tritiated scavenger. This approach eliminates the use of heavy metal catalysts

  4. Investigation of the effects of dynamic change in curvature and torsion on pulsatile flow in a helical tube.

    Science.gov (United States)

    Selvarasu, N K C; Tafti, Danesh K

    2012-07-01

    Cardiovascular diseases are the number one cause of death in the world, making the understanding of hemodynamics and the development of treatment options imperative. The effect of motion of the coronary artery due to the motion of the myocardium is not extensively studied. In this work, we focus our investigation on the localized hemodynamic effects of dynamic changes in curvature and torsion. It is our objective to understand and reveal the mechanism by which changes in curvature and torsion contribute towards the observed wall shear stress distribution. Such adverse hemodynamic conditions could have an effect on circumferential intimal thickening. Three-dimensional spatiotemporally resolved computational fluid dynamics (CFD) simulations of pulsatile flow with moving wall boundaries were carried out for a simplified coronary artery with physiologically relevant flow parameters. A model with stationary walls is used as the baseline control case. In order to study the effect of curvature and torsion variation on local hemodynamics, this baseline model is compared to models where the curvature, torsion, and both curvature and torsion change. The simulations provided detailed information regarding the secondary flow dynamics. The results suggest that changes in curvature and torsion cause critical changes in local hemodynamics, namely, altering the local pressure and velocity gradients and secondary flow patterns. The wall shear stress (WSS) varies by a maximum of 22% when the curvature changes, by 3% when the torsion changes, and by 26% when both the curvature and torsion change. The oscillatory shear stress (OSI) varies by a maximum of 24% when the curvature changes, by 4% when the torsion changes, and by 28% when both the curvature and torsion change. We demonstrate that these changes are attributed to the physical mechanism associating the secondary flow patterns to the production of vorticity (vorticity flux) due to the wall movement. The secondary flow patterns

  5. The "black hole" phenomenon in ultrasonic backscattering measurement under pulsatile flow with porcine whole blood in a rigid tube.

    Science.gov (United States)

    Cao, P J; Paeng, D G; Shung, K K

    2001-01-01

    The "black hole" phenomenon was further investigated with porcine whole blood under pulsatile flow conditions in a straight rigid tube 120 cm long and of 0.95 cm diameter. A modified Aloka 280 commercial scanner with a 7.5 MHz linear array was used to collect the radio frequency (RF) signal of backscattering echoes from the blood inside the tube. The transducer was located downstream from the entrance and parallel to the longitudinal direction of the tube. The experimental results showed that higher hematocrits enhanced the black hole phenomenon, leading to a more apparent and larger diameter black hole. The black hole was not apparent at hematocrits below 23%. The highest hematocrit used in the experiment was 60%. Beat rates of 20, 40 and 60 beats per minute (bpm) were used, and the black hole became weaker in amplitude and smaller in diameter when the peak flow velocity was increased at each beat rate. These results are consistent with the suggestion in previous work that the black hole arises from insufficient aggregation of red blood cells (RBCs) at the center of the tube because of the low shear rate. At 20 and 40 bpm, the peak flow velocity ranges were 10 approximately 25 cm/s and 18 approximately 27 cm/s, respectively. The black hole was very clear at the minimal peak flow velocity but almost disappeared at the maximal velocities for each beat rate. At 60 bpm, experiments were only performed at one peak flow velocity of 31 cm/s and the black hole was clear. The results showed that the black hole was more pronounced at higher beat rates when the peak velocity was the same. This phenomenon cannot be explained by previous hypotheses. Acceleration seems to be the only flow parameter that varies at different beat rates when peak velocities are the same. Therefore, the influence of acceleration on the structural organization and orientation of RBC rouleaux might be another factor involved in the formation of the black hole in addition to the shear rate. As the

  6. Parathyroid Hormone Levels and Cognition

    Science.gov (United States)

    Burnett, J.; Smith, S.M.; Aung, K.; Dyer, C.

    2009-01-01

    Hyperparathyroidism is a well-recognized cause of impaired cognition due to hypercalcemia. However, recent studies have suggested that perhaps parathyroid hormone itself plays a role in cognition, especially executive dysfunction. The purpose of this study was to explore the relationship of parathyroid hormone levels in a study cohort of elders with impaied cognition. Methods: Sixty community-living adults, 65 years of age and older, reported to Adult Protective Services for self-neglect and 55 controls matched (on age, ethnicity, gender and socio-economic status) consented and participated in this study. The research team conducted in-home comprehensive geriatric assessments which included the Mini-mental state exam (MMSE), the 15-item geriatric depression scale (GDS) , the Wolf-Klein clock test and a comprehensive nutritional panel, which included parathyroid hormone and ionized calcium. Students t tests and linear regression analyses were performed to assess for bivariate associations. Results: Self-neglecters (M = 73.73, sd=48.4) had significantly higher PTH levels compared to controls (M =47.59, sd=28.7; t=3.59, df=98.94, p<.01). There was no significant group difference in ionized calcium levels. Overall, PTH was correlated with the MMSE (r=-.323, p=.001). Individual regression analyses revealed a statistically significant correlation between PTH and MMSE in the self-neglect group (r=-.298, p=.024) and this remained significant after controlling for ionized calcium levels in the regression. No significant associations were revealed in the control group or among any of the other cognitive measures. Conclusion: Parathyroid hormone may be associated with cognitive performance.

  7. Growth hormone and its disorders

    OpenAIRE

    Ayuk, J.; Sheppard, M C

    2006-01-01

    Growth hormone (GH) is synthesised and secreted by the somatotroph cells of the anterior lobe of the pituitary gland. Its actions involve multiple organs and systems, affecting postnatal longitudinal growth as well as protein, lipid, and carbohydrate metabolism. GH hypersecretion results in gigantism or acromegaly, a condition associated with significant morbidity and mortality, while GH deficiency results in growth retardation in children and the GH deficiency syndrome in adults. This articl...

  8. Reproductive Hormones and Mood Disorders

    OpenAIRE

    Sermin Kesebir; Arzu Etlik Aksoy

    2010-01-01

    During the menstrual cycle, pregnancy and breast-feeding periods, as well as in menopausal and post-menopausal periods, the physiological and psychological processes that change according to the hormonal fluctuations influence every women similarly and each one differently. These physiological processes are controlled by neuroendocrine sequences, of which the hypothalamo-pituitary-adrenal axis and the hypothalamo-pituitary-gonadal axis are the most important ones. The hypothalamo-pituitary-go...

  9. Growth hormone doping: a review

    OpenAIRE

    Sonksen, Peter

    2011-01-01

    Ioulietta Erotokritou-Mulligan, Richard IG Holt, Peter H SönksenDevelopmental Origins of Health and Disease Division, University of Southampton School of Medicine, The Institute of Developmental Science, Southampton General Hospital, Southampton, UKAbstract: The use of growth hormone (GH) as a performance enhancing substance was first promoted in lay publications, long before scientists fully acknowledged its benefits. It is thought athletes currently use GH to enhance their athletic...

  10. Parathyroid Hormone Levels and Cognition

    Science.gov (United States)

    Burnett, J.; Smith, S.M.; Aung, K.; Dyer, C.

    2009-01-01

    Hyperparathyroidism is a well-recognized cause of impaired cognition due to hypercalcemia. However, recent studies have suggested that perhaps parathyroid hormone itself plays a role in cognition, especially executive dysfunction. The purpose of this study was to explore the relationship of parathyroid hormone levels in a study cohort of elders with impaied cognition. Methods: Sixty community-living adults, 65 years of age and older, reported to Adult Protective Services for self-neglect and 55 controls matched (on age, ethnicity, gender and socio-economic status) consented and participated in this study. The research team conducted in-home comprehensive geriatric assessments which included the Mini-mental state exam (MMSE), the 15-item geriatric depression scale (GDS) , the Wolf-Klein clock test and a comprehensive nutritional panel, which included parathyroid hormone and ionized calcium. Students t tests and linear regression analyses were performed to assess for bivariate associations. Results: Self-neglecters (M = 73.73, sd=48.4) had significantly higher PTH levels compared to controls (M =47.59, sd=28.7; t=3.59, df=98.94, plevels. Overall, PTH was correlated with the MMSE (r=-.323, p=.001). Individual regression analyses revealed a statistically significant correlation between PTH and MMSE in the self-neglect group (r=-.298, p=.024) and this remained significant after controlling for ionized calcium levels in the regression. No significant associations were revealed in the control group or among any of the other cognitive measures. Conclusion: Parathyroid hormone may be associated with cognitive performance.

  11. Hormonal crosstalk in plant immunity

    OpenAIRE

    D. Van der Does

    2012-01-01

    The plant hormones salicylic acid (SA), also known as plant aspirin, and jasmonic acid (JA) play major roles in the regulation of the plant immune system. In general, SA is important for defense against pathogens with a biotrophic lifestyle, whereas JA is essential for defense against insect herbivores and pathogens with a necrotrophic lifestyle. Antagonistic and synergistic interactions between the SA- and JA-dependent signaling pathways allow the plant to fine-tune the activation of defense...

  12. Hormesis and Female Sex Hormones

    OpenAIRE

    Elvar Theodorsson; Jakob O. Strom; Annette Theodorsson

    2011-01-01

    Hormone replacement after menopause has in recent years been the subject of intense scientific debate and public interest and has sparked intense research efforts into the biological effects of estrogens and progestagens. However, there are reasons to believe that the doses used and plasma concentrations produced in a large number of studies casts doubt on important aspects of their validity. The concept of hormesis states that a substance can have diametrically different effects depending on...

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

    Directory of Open Access Journals (Sweden)

    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

  14. Hormonal Regulation and Expression Profiles of Wheat Genes Involved during Phytic Acid Biosynthesis Pathway

    OpenAIRE

    Sipla Aggarwal; Vishnu Shukla; Kaushal Kumar Bhati; Mandeep Kaur; Shivani Sharma; Anuradha Singh; Shrikant Mantri; Ajay Kumar Pandey

    2015-01-01

    Phytic acid (PA) biosynthesis pathway genes were reported from multiple crop species. PA accumulation was enhanced during grain filling and at that time, hormones like Abscisic acid (ABA) and Gibberellic acid (GA3) interplay to control the process of seed development. Regulation of wheat PA pathway genes has not yet been reported in seeds. In an attempt to find the clues for the regulation by hormones, the promoter region of wheat PA pathway genes was analyzed for the presence of cis-elements...

  15. The Biological Effects of Sex Hormones on Rabbit Articular Chondrocytes from Different Genders

    OpenAIRE

    Shwu Jen Chang; Shyh Ming Kuo; Yen Ting Lin; Shan-Wei Yang

    2014-01-01

    The aim of this study was to investigate the biological effects of sex hormones (17 β -estradiol and testosterone) on rabbit articular chondrocytes from different genders. We cultured primary rabbit articular chondrocytes from both genders with varying concentration of sex hormones. We evaluate cell proliferation and biochemical functions by MTT and GAG assay. The chondrocyte function and phenotypes were analyzed by mRNA level using RT-PCR. Immunocytochemical staining was also used to evaluat...

  16. BLOOD METABOLIC HORMONES AND LEPTIN IN GROWING LAMBS

    Directory of Open Access Journals (Sweden)

    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.

  17. Analyzing Valuation Practices through Contracts

    DEFF Research Database (Denmark)

    Tesnière, Germain; Labatut, Julie; Boxenbaum, Eva

    This paper seeks to analyze the most recent changes in how societies value animals. We analyze this topic through the prism of contracts between breeding companies and farmers. Focusing on new valuation practices and qualification of breeding animals, we question the evaluation of difficult...

  18. Analyzing data files in SWAN

    CERN Document Server

    Gajam, Niharika

    2016-01-01

    Traditionally analyzing data happens via batch-processing and interactive work on the terminal. The project aims to provide another way of analyzing data files: A cloud-based approach. It aims to make it a productive and interactive environment through the combination of FCC and SWAN software.

  19. Pituitary carcinoma with different hormone expressions

    Directory of Open Access Journals (Sweden)

    Tao LU

    2015-01-01

    Full Text Available Objective To introduce the experience of diagnosing and treating one case of pituitary carcinoma with distinct hormone expressions in primary and metastatic lesions and to improve understanding of this disease.  Methods Retrospective study was performed to analyze the clinical manifestations, imaging characteristics, histopathologic findings, and treatment information of the patient. Immunohistochemical staining was done to both primary and metastatic lesions.  Results The patient presented with eye pain and discomfort 4 months posterior to pituitary adenoma surgery. Head MRI showed multiple abnormal intracranial signals, irregular pituitary contour, and abnormal enhancements of the sellar region. PET-CT scan showed multiple hypermetabolic lesions. After the first surgery, histological study of the pituitary tumor showed disseminated tumor cells. The cells were round-shaped or polygonal, with mild atypia, moderate amount of eosinophilic plasma and round-shaped nuclei with fine chromatin and unconspicuous nucleoli; mitosis was abundant, while necrosis was absent. The tumor cells expressed P53, chromogranin A (CgA, with scattered expression for growth hormone (GH and a Ki-67 index of 80% by immunohistochemistry. The first pathologic diagnosis was atypical pituitary adenoma. The parietal tumor cells infiltrated parenchymal after the tumor recurrence. Immunohistochemistry findings were different from the first one. The tumor cells expressed GH diffusely, with a decreased Ki-67 index of 75%. The second pathologic diagnosis was metastatic pituitary carcinoma.  Conclusions Pituitary carcinoma is a rare malignant pituitary tumor. Diagnosis relies on radiology and pathology. Surgical resection and radiochemotherapy are the current treatment of choice but yield poor response. General prognosis of the disease is poor. DOI: 10.3969/j.issn.1672-6731.2015.01.013

  20. Nuclear fuel microsphere gamma analyzer

    Science.gov (United States)

    Valentine, Kenneth H.; Long, Jr., Ernest L.; Willey, Melvin G.

    1977-01-01

    A gamma analyzer system is provided for the analysis of nuclear fuel microspheres and other radioactive particles. The system consists of an analysis turntable with means for loading, in sequence, a plurality of stations within the turntable; a gamma ray detector for determining the spectrum of a sample in one section; means for analyzing the spectrum; and a receiver turntable to collect the analyzed material in stations according to the spectrum analysis. Accordingly, particles may be sorted according to their quality; e.g., fuel particles with fractured coatings may be separated from those that are not fractured, or according to other properties.

  1. 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....

  2. Thyroid hormone resistance and its management

    Science.gov (United States)

    Lado-Abeal, Joaquin

    2016-01-01

    The syndrome of impaired sensitivity to thyroid hormone, also known as syndrome of thyroid hormone resistance, is an inherited condition that occurs in 1 of 40,000 live births characterized by a reduced responsiveness of target tissues to thyroid hormone due to mutations on the thyroid hormone receptor. Patients can present with symptoms of hyperthyroidism or hypothyroidism. They usually have elevated thyroid hormones and a normal or elevated thyroid-stimulating hormone level. Due to their nonspecific symptomatic presentation, these patients can be misdiagnosed if the primary care physician is not familiar with the condition. This can result in frustration for the patient and sometimes unnecessary invasive treatment such as radioactive iodine ablation, as in the case presented herein. PMID:27034574

  3. Anabolic hormone profiles in elite military men.

    Science.gov (United States)

    Taylor, Marcus K; Kviatkovsky, Shiloah A; Hernández, Lisa M; Sargent, Paul; Segal, Sabrina; Granger, Douglas A

    2016-06-01

    We recently characterized the awakening responses and daily profiles of the catabolic stress hormone cortisol in elite military men. Anabolic hormones follow a similar daily pattern and may counteract the catabolic effects of cortisol. This companion report is the first to characterize daily profiles of anabolic hormones dehydroepiandrosterone (DHEA) and testosterone in this population. Overall, the men in this study displayed anabolic hormone profiles comparable to that of healthy, athletic populations. Consistent with the cortisol findings in our prior report, summary parameters of magnitude (hormone output) within the first hour after awakening displayed superior stability versus summary parameters of pattern for both DHEA (r range: 0.77-0.82) and testosterone (r range: 0.62-0.69). Summary parameters of evening function were stable for the two hormones (both panabolic balance and resultant effects upon health and human performance in this highly resilient yet chronically stressed population. PMID:27083310

  4. Sex steroids and growth hormone interactions.

    Science.gov (United States)

    Fernández-Pérez, Leandro; de Mirecki-Garrido, Mercedes; Guerra, Borja; Díaz, Mario; Díaz-Chico, Juan Carlos

    2016-04-01

    GH and sex hormones are critical regulators of body growth and composition, somatic development, intermediate metabolism, and sexual dimorphism. Deficiencies in GH- or sex hormone-dependent signaling and the influence of sex hormones on GH biology may have a dramatic impact on liver physiology during somatic development and in adulthood. Effects of sex hormones on the liver may be direct, through hepatic receptors, or indirect by modulating endocrine, metabolic, and gender-differentiated functions of GH. Sex hormones can modulate GH actions by acting centrally, regulating pituitary GH secretion, and peripherally, by modulating GH signaling pathways. The endocrine and/or metabolic consequences of long-term exposure to sex hormone-related compounds and their influence on the GH-liver axis are largely unknown. A better understanding of these interactions in physiological and pathological states will contribute to preserve health and to improve clinical management of patients with growth, developmental, and metabolic disorders. PMID:26775014

  5. Ovarian Cyst Formation Following Gonadotropin-Releasing Hormone-Agonist Administration Decreases the Oocyte Quality in IVF Cycles

    OpenAIRE

    Muammer Doğan; Sevtap Hamdemir; Fatma Nur Aksakal; Esma Sarıkaya; Özlem Gün Eryılmaz; Leyla Mollamahmutoğlu

    2012-01-01

    Objective: The gonadotropin-releasing hormone-agonist (GnRH-a) treatment during in vitro fertilization (IVF) sometimes causes a functional ovarian cyst during the administration period before gonadotropin stimulation, as an undesired event. The aim of this study was to analyze the effect of these cysts on the IVF outcomes.Materials and Methods: Out of 981 IVF cycles, 78 with ovarian cysts were retrospectively analyzed with respect to the demographic characteristics, hormonal outcomes, and fer...

  6. The thyroid hormone, parathyroid hormone and vitamin D associated hypertension

    Directory of Open Access Journals (Sweden)

    Sandeep Chopra

    2011-01-01

    Full Text Available Thyroid disorders and primary hyperparathyroidism have been known to be associated with increases in blood pressure. The hypertension related to hypothyroidism is a result of increased peripheral resistance, changes in renal hemodynamics, hormonal changes and obesity. Treatment of hypothyroidism with levo-thyroxine replacement causes a decrease in blood pressure and an overall decline in cardiovascular risk. High blood pressure has also been noted in patients with subclinical hypothyroidism. Hyperthyroidism, on the other hand, is associated with systolic hypertension resulting from an expansion of the circulating blood volume and increase in stroke volume. Increased serum calcium levels associated with a primary increase in parathyroid hormone levels have been also associated with high blood pressure recordings. The mechanism for this is not clear but the theories include an increase in the activity of the renin-angiotensin-aldosterone system and vasoconstriction. Treatment of primary hyperparathyroidism by surgery results in a decline in blood pressure and a decrease in the plasma renin activity. Finally, this review also looks at more recent evidence linking hypovitaminosis D with cardiovascular risk factors, particularly hypertension, and the postulated mechanisms linking the two.

  7. Human growth hormone (HGH), ch. 6

    International Nuclear Information System (INIS)

    A radioimmunoassay method for the human growth hormone (HGH) is described. The requirements are discussed in detail and a scheme for the preparation of incubation mixtures is given. HGH is labelled with 125I by the chloramine T method and purified by gel filtration or electrophoresis. Separation of bound and free-labelled hormones is performed by absorption of the free hormone, using talc or charcoal

  8. Monitoring Plant Hormones During Stress Responses

    OpenAIRE

    Engelberth, Marie J.; Engelberth, Jurgen

    2009-01-01

    Plant hormones and related signaling compounds play an important role in the regulation of plant responses to various environmental stimuli and stresses. Among the most severe stresses are insect herbivory, pathogen infection, and drought stress. For each of these stresses a specific set of hormones and/or combinations thereof are known to fine-tune the responses, thereby ensuring the plant's survival. The major hormones involved in the regulation of these responses are jasmonic acid (JA), sa...

  9. Plant Hormones: Metabolism, Signaling and Crosstalk

    Institute of Scientific and Technical Information of China (English)

    Li-Jia Qu; Yunde Zhao

    2011-01-01

    @@ Plants synthesize various hormones in response to environmental cues and developmental signals to ensure their proper growth and development.Elucidation of the molecular mechanisms by which plant hormones control growth and development contributes to our understanding of fundamental plant biology and provides tools to improve crops.Because of their critical roles in plant growth and development, plant hormones have been studied extensively since the early days of plant biology.

  10. Hormones and aggression in childhood and adolescence

    OpenAIRE

    Ramirez, J. Martin

    2003-01-01

    This review is a survey on recent psychobiosocial studies on association between hormones and aggression/violence in children and adolescents, with a special focus on puberty, given the rapid changes in both hormones and behavior occurring during that developmental period. Since it cannot be assumed that all readers have much background knowledge, it inevitably begins with some comments about the concept and multifaceted nature of aggression, as well as with a brief reminding about hormone ca...

  11. Leptin and Hormones: Energy Homeostasis.

    Science.gov (United States)

    Triantafyllou, Georgios A; Paschou, Stavroula A; Mantzoros, Christos S

    2016-09-01

    Leptin, a 167 amino acid adipokine, plays a major role in human energy homeostasis. Its actions are mediated through binding to leptin receptor and activating JAK-STAT3 signal transduction pathway. It is expressed mainly in adipocytes, and its circulating levels reflect the body's energy stores in adipose tissue. Recombinant methionyl human leptin has been FDA approved for patients with generalized non-HIV lipodystrophy and for compassionate use in subjects with congenital leptin deficiency. The purpose of this review is to outline the role of leptin in energy homeostasis, as well as its interaction with other hormones. PMID:27519135

  12. Hormonal contraceptives and venous thrombosis

    OpenAIRE

    Stegeman, Berendina Hendrika (Bernardine)

    2013-01-01

    Oral contraceptive use is associated with venous thrombosis. However, the mechanism behind this remains unclear. The aim of this thesis was to evaluate genetic variation in the first-pass metabolism of contraceptives, to identify the clinical implications of hormonal contraceptive use after a thrombotic event and to provide an overview of the risk of venous thrombosis per combined oral contraceptive. We found that the UGT2B7 gene in the first-pass metabolism may at least in part explain the r...

  13. Thyroid hormones and cardiac arrhythmias

    Czech Academy of Sciences Publication Activity Database

    Tribulová, N.; Knezl, V.; Shainberg, A.; Seki, S.; Soukup, Tomáš

    2010-01-01

    Roč. 52, 3-4 (2010), s. 102-112. ISSN 1537-1891 R&D Projects: GA ČR(CZ) GA304/08/0256 Grant ostatní: VEGA(SK) 2/0049/09; APVV(SK) 51-059505; APVV(SK) 51-017905 Institutional research plan: CEZ:AV0Z50110509 Keywords : thyroid hormone * arrhythmias * ion channels * connexin-43 Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 2.174, year: 2010

  14. Steroid hormone runoff from agricultural test plots applied with municipal biosolids

    Science.gov (United States)

    Yang, Yun-Ya; Gray, James L.; Furlong, Edward T.; Davis, Jessica G.; ReVollo, Rhiannon C.; Borch, Thomas

    2012-01-01

    The potential presence of steroid hormones in runoff from sites where biosolids have been used as agricultural fertilizers is an environmental concern. A study was conducted to assess the potential for runoff of seventeen different hormones and two sterols, including androgens, estrogens, and progestogens from agricultural test plots. The field containing the test plots had been applied with biosolids for the first time immediately prior to this study. Target compounds were isolated by solid-phase extraction (water samples) and pressurized solvent extraction (solid samples), derivatized, and analyzed by gas chromatography–tandem mass spectrometry. Runoff samples collected prior to biosolids application had low concentrations of two hormones (estrone -1 and androstenedione -1) and cholesterol (22.5 ± 3.8 μg L-1). In contrast, significantly higher concentrations of multiple estrogens (-1), androgens (-1), and progesterone (-1) were observed in runoff samples taken 1, 8, and 35 days after biosolids application. A significant positive correlation was observed between antecedent rainfall amount and hormone mass loads (runoff). Hormones in runoff were primarily present in the dissolved phase (<0.7-μm GF filter), and, to a lesser extent bound to the suspended-particle phase. Overall, these results indicate that rainfall can mobilize hormones from biosolids-amended agricultural fields, directly to surface waters or redistributed to terrestrial sites away from the point of application via runoff. Although concentrations decrease over time, 35 days is insufficient for complete degradation of hormones in soil at this site.

  15. Gender-specific regulation of response to thyroid hormone in aging

    Directory of Open Access Journals (Sweden)

    Suzuki Satoru

    2012-01-01

    Full Text Available Abstract Background Similar to other systems, the endocrine system is affected by aging. Thyroid hormone, the action of which is affected by many factors, has been shown to be associated with longevity. The most useful marker for the assessment of thyroid hormone action is TSH level. Although age and gender are believed to modify the pituitary set point or response to free thyroid hormone concentration, the precise age- and gender-dependent responses to thyroid hormone have yet to be reported. Methods We analyzed the results of 3564 thyroid function tests obtained from patients who received medication at both out- and inpatient clinics of Shinshu University Hospital. Subjects were from among those with thyroid function test results in the normal or mildly abnormal range. Based on a log-linear relationship between the concentrations of FHs and TSH, we established the putative resistance index to assess the relation between serum FH and TSH levels. Results Free thyroid hormone and TSH concentration showed an inverse log-linear relation. In males, there was a negative relationship between the free T3 resistance index and age. In females, although there were no relationships between age and FHs, the indices were positively related to age. Conclusions These findings indicated that there is a gender-specific response to thyroid hormone with aging. Although the TSH level is a useful marker for the assessment of peripheral thyroid hormone action, the values should be interpreted carefully, especially with regard to age- and gender-related differences.

  16. Pituitary hormone circadian rhythm alterations in cirrhosis patients with subclinical hepatic encephalopathy

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    AIM: To analyze pituitary hormone and melatonin cir- cadian rhythms, and to correlate hormonal alterations with clinical performance, hepatic disease severity and diagnostic tests used for the detection of hepatic en- cephalopathy in cirrhosis. METHODS: Twenty-six patients with cirrhosis were enrolled in the study. Thirteen patients hospitalized for systemic diseases not affecting the liver were included as controls. Liver disease severity was assessed by the Child-Pugh score. All patients underwent detailed neurological assessment, electroencephalogram (EEG), brain magnetic resonance imaging (MRI), assays of pi- tuitary hormone, cortisol and melatonin, and complete blood chemistry evaluation. RESULTS: Pituitary hormone and melatonin circadian patterns were altered in cirrhosis patients without clinical encephalopathy. Circadian hormone alterations were different in cirrhosis patients compared with con- trois. Although cortisol secretion was not altered in any patient with cirrhosis, the basal cortisol levels were low and correlated with EEG and brain MRI abnormalities. Melatonin was the only hormone associated with the severity of liver insufficiency. CONCLUSION: Abnormal pituitary hormone and mel- atonin circadian patterns are present in cirrhosis before the development of hepatic encephalopathy. These abnormalities may be early indicators of impending hepatic encephalopathy. Factors affecting the human biologic clock at the early stages of liver insufficiency require further study.

  17. Predicting the Probability of Abnormal Stimulated Growth Hormone Response in Children After Radiotherapy for Brain Tumors

    International Nuclear Information System (INIS)

    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.

  18. 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.

  19. SU-D-18C-04: The Feasibility of Quantifying MRI Contrast Agent in Pulsatile Flowing Blood Using DCE-MRI

    Energy Technology Data Exchange (ETDEWEB)

    N, Gwilliam M; J, Collins D; O, Leach M; R, Orton M [Institute of Cancer Research, London (United Kingdom)

    2014-06-01

    Purpose: To assess the feasibility of accurately quantifying the concentration of MRI contrast agent (CA) in pulsatile flowing blood by measuring its T{sub 1}, as is common for the purposes of obtaining a patientspecific arterial input function (AIF). Dynamic contrast enhanced (DCE) - MRI and pharmacokinetic (PK) modelling is widely used to produce measures of vascular function but accurate measurement of the AIF undermines their accuracy. A proposed solution is to measure the T{sub 1} of blood in a large vessel using the Fram double flip angle method during the passage of a bolus of CA. This work expands on previous work by assessing pulsatile flow and the changes in T{sub 1} seen with a CA bolus. Methods: A phantom was developed which used a physiological pump to pass fluid of a known T{sub 1} (812ms) through the centre of a head coil of a clinical 1.5T MRI scanner. Measurements were made using high temporal resolution sequences suitable for DCE-MRI and were used to validate a virtual phantom that simulated the expected errors due to pulsatile flow and bolus of CA concentration changes typically found in patients. Results: : Measured and virtual results showed similar trends, although there were differences that may be attributed to the virtual phantom not accurately simulating the spin history of the fluid before entering the imaging volume. The relationship between T{sub 1} measurement and flow speed was non-linear. T{sub 1} measurement is compromised by new spins flowing into the imaging volume, not being subject to enough excitations to have reached steady-state. The virtual phantom demonstrated a range of recorded T{sub 1} for various simulated T{sub 1} / flow rates. Conclusion: T{sub 1} measurement of flowing blood using standard DCE-MRI sequences is very challenging. Measurement error is non-linear with relation to instantaneous flow speed. Optimising sequence parameters and lowering baseline T{sub 1} of blood should be considered.

  20. Anomalies in the hormonal status of athymic nude mice.

    Science.gov (United States)

    Köpf-Maier, P; Mboneko, V F

    1990-01-01

    The serum levels of hormones that are known to influence growth, development, and differentiation of the skin and its appendages were analyzed in female haired (NMRI) and nude (NMRI, nu/nu) mice. Whereas the concentrations of testosterone, prolactin, and triiodothyronine did not differ in nude animals from those found in normal mice of the same age in the anestrous phase of the sexual cycle, the serum levels of estradiol, progesterone, and thyroxine were found in female nude mice at significantly lower levels than in normally haired animals. These results point to a hormonal situation that contributes to the poor fertility of homozygous (nu/nu) female mice and may promote impairment of growth and differentiation of skin and hair, resulting in the macroscopic nudity of athymic, nude mice. PMID:2370246

  1. Trans-activation by thyroid hormone receptors: functional parallels with steroid hormone receptors.

    OpenAIRE

    Thompson, C C; Evans, R M

    1989-01-01

    The effects of thyroid hormones are mediated through nuclear receptor proteins that modulate the transcription of specific genes in target cells. We previously isolated cDNAs encoding two different mammalian thyroid hormone receptors, one from human placenta (hTR beta) and the other from rat brain (rTR alpha), and showed that their in vitro translation products bind thyroid hormones with the characteritistic affinities of the native thyroid hormone receptor. We now demonstrate that both of th...

  2. 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.......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....

  3. SCAN: a Fortran syntax analyzer

    International Nuclear Information System (INIS)

    SCAN is a computer program which analyzes the syntax of a Fortran program. It reads statements of a Fortran program, checks the grammatical validity of them, and produces tables of the analyzed results and intermediate codes for further use. SCAN recognizes the Fortran syntax of the Japan Industrial Standards-7000, plus some Fortran-H statements. In this report, the structure of SCAN, the methods used by the SCAN to analyze statements, tables and intermediate Buckus form texts produced by the SCAN, are presented. The SCAN itself is also written in Fortran language and consists of about 5000 statements. By slight modifications the SCAN may be useful for any application which needs analysis operations of Fortran syntax. (author)

  4. Age-Specific Serum Anti-Mullerian Hormone and Follicle Stimulating Hormone Concentrations in Infertile Iranian Women

    Directory of Open Access Journals (Sweden)

    Alireza Raeissi

    2015-04-01

    Full Text Available Background: Anti-Müllerian hormone (AMH is secreted by the granulosa cells of growing follicles during the primary to large antral follicle stages. Abnormal levels of AMH and follicle stimulating hormone (FSH may indicate a woman’s diminished ability or inability to conceive. Our aim is to investigate the changes in serum AMH and FSH concentrations at different age groups and its correlation with ovarian reserves in infertile women. Materials and Methods: This cross-sectional study analyzed serum AMH and FSH levels from 197 infertile women and 176 healthy controls, whose mean ages were 19-47 years. Sample collection was performed by random sampling and analyzed with SPSS version 16 software. Results: There were significantly lower mean serum AMH levels among infertile women compared to the control group. The mean AMH serum levels from different ages of infertile and control group (fertile women decreased with increasing age. However, this reduction was greater in the infertile group. The mean FSH serum levels of infertile women were significantly higher than the control group. Mean serum FSH levels consistently increased with increasing age in infertile women; however mean luteinizing hormone (LH levels were not consistent. Conclusion: We have observed increased FSH levels and decreased AMH levels with increasing age in women from 19 to 47 years of age. Assessments of AMH and FSH levels in combination with female age can help in predicting ovarian reserve in infertile women.

  5. Loviisa nuclear power plant analyzer

    International Nuclear Information System (INIS)

    The APROS Simulation Environment has been developed since 1986 by Imatran Voima Oy (IVO) and the Technical Research Centre of Finland (VTT). It provides tools, solution algorithms and process components for use in different simulation systems for design, analysis and training purposes. One of its main nuclear applications is the Loviisa Nuclear Power Plant Analyzer (LPA). The Loviisa Plant Analyzer includes all the important plant components both in the primary and in the secondary circuits. In addition, all the main control systems, the protection system and the high voltage electrical systems are included. (orig.)

  6. Analyzing the Grammar of English

    CERN Document Server

    Teschner, Richard V

    2007-01-01

    Analyzing the Grammar of English offers a descriptive analysis of the indispensable elements of English grammar. Designed to be covered in one semester, this textbook starts from scratch and takes nothing for granted beyond a reading and speaking knowledge of English. Extensively revised to function better in skills-building classes, it includes more interspersed exercises that promptly test what is taught, simplified and clarified explanations, greatly expanded and more diverse activities, and a new glossary of over 200 technical terms.Analyzing the Grammar of English is the only English gram

  7. Metabolism of growth hormone releasing peptides.

    Science.gov (United States)

    Thomas, Andreas; Delahaut, Philippe; Krug, Oliver; Schänzer, Wilhelm; Thevis, Mario

    2012-12-01

    New, potentially performance enhancing compounds have frequently been introduced to licit and illicit markets and rapidly distributed via worldwide operating Internet platforms. Developing fast analytical strategies to follow these new trends is one the most challenging issues for modern doping control analysis. Even if reference compounds for the active drugs are readily obtained, their unknown metabolism complicates effective testing strategies. Recently, a new class of small C-terminally amidated peptides comprising four to seven amino acid residues received considerable attention of sports drug testing authorities due to their ability to stimulate growth hormone release from the pituitary. The most promising candidates are the growth hormone releasing peptide (GHRP)-1, -2, -4, -5, -6, hexarelin, alexamorelin, and ipamorelin. With the exemption of GHRP-2, the entity of these peptides represents nonapproved pharmaceuticals; however, via Internet providers, all compounds are readily available. To date, only limited information on the metabolism of these substances is available and merely one metabolite for GHRP-2 is established. Therefore, a comprehensive in vivo (po and iv administration in rats) and in vitro (with human serum and recombinant amidase) study was performed in order to generate information on urinary metabolites potentially useful for routine doping controls. The urine samples from the in vivo experiments were purified by mixed-mode cation-exchange solid-phase extraction and analyzed by ultrahigh-performance liquid chromatography (UHPLC) separation followed by high-resolution/high-accuracy mass spectrometry. Combining the high resolution power of a benchtop Orbitrap mass analyzer for the first metabolite screening and the speed of a quadrupole/time-of-flight (Q-TOF) instrument for identification, urinary metabolites were screened by means of a sensitive full scan analysis and subsequently confirmed by high-accuracy product ion scan experiments. Two

  8. 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 m...

  9. Hormesis and Female Sex Hormones

    Directory of Open Access Journals (Sweden)

    Elvar Theodorsson

    2011-05-01

    Full Text Available Hormone replacement after menopause has in recent years been the subject of intense scientific debate and public interest and has sparked intense research efforts into the biological effects of estrogens and progestagens. However, there are reasons to believe that the doses used and plasma concentrations produced in a large number of studies casts doubt on important aspects of their validity. The concept of hormesis states that a substance can have diametrically different effects depending on the concentration. Even though estrogens and progestagens have proven prone to this kind of dose-response relation in a multitude of studies, the phenomenon remains clearly underappreciated as exemplified by the fact that it is common practice to only use one hormone dose in animal experiments. If care is not taken to adjust the concentrations of estrogens and progestagens to relevant biological conditions, the significance of the results may be questionable. Our aim is to review examples of female sexual steroids demonstrating bidirectional dose-response relations and to discuss this in the perspective of hormesis. Some examples are highlighted in detail, including the effects on cerebral ischemia, inflammation, cardiovascular diseases and anxiety. Hopefully, better understanding of the hormesis phenomenon may result in improved future designs of studies of female sexual steroids.

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

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jian.

    1989-01-01

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

  11. Portable pulse height analyzing system

    International Nuclear Information System (INIS)

    Low power, battery operated, compact Portable Pulse Height Analyzing System/Multi Channel Analyzer (PMCA) has been designed and developed for monitoring the various low activity radioisotopes in situ. PMCA can also be used in mobile radiation monitoring vans, wherein, gamma spectrum data collected at different locations can be stored in the battery backed RAM disk and down-loaded on to the PC via a serial link. Designed primarily for measurement and analysis of isotope activity and for field experiments, it can be used with most of the radiation detectors used for pulse height spectrum analysis. PMCA is built around embedded PC hardware architecture wherein all the cards are made with state of the art technology with extensive use of SMT and ASICS. PMCA provides features comparable with standard laboratory models and enables computation of integral area, background area, net peak area, FWHM, peak centroid and energy calibration in the field. This paper describes Portable Pulse Height Analyzing System with focus on following features: a) Hardware implementation of well-known multi channel analyzer technique using embedded PC hardware architecture. b) Software implementation of spectrum acquisition and analysis using high level language namely, C. (author)

  12. Analyzing Software Piracy in Education.

    Science.gov (United States)

    Lesisko, Lee James

    This study analyzes the controversy of software piracy in education. It begins with a real world scenario that presents the setting and context of the problem. The legalities and background of software piracy are explained and true court cases are briefly examined. Discussion then focuses on explaining why individuals and organizations pirate…

  13. Helping Students Analyze Business Documents.

    Science.gov (United States)

    Devet, Bonnie

    2001-01-01

    Notes that student writers gain greater insight into the importance of audience by analyzing business documents. Discusses how business writing teachers can help students understand the rhetorical refinements of writing to an audience. Presents an assignment designed to lead writers systematically through an analysis of two advertisements. (SG)

  14. Software-Design-Analyzer System

    Science.gov (United States)

    Tausworthe, Robert C.

    1991-01-01

    CRISP-90 software-design-analyzer system, update of CRISP-80, is set of computer programs constituting software tool for design and documentation of other software and supporting top-down, hierarchical, modular, structured methodologies for design and programming. Written in Microsoft QuickBasic.

  15. FORTRAN Static Source Code Analyzer

    Science.gov (United States)

    Merwarth, P.

    1984-01-01

    FORTRAN Static Source Code Analyzer program, SAP (DEC VAX version), automatically gathers statistics on occurrences of statements and structures within FORTRAN program and provides reports of those statistics. Provisions made for weighting each statistic and provide an overall figure of complexity.

  16. Pulsatile flow and heat transfer of a magneto-micropolar fluid through a stenosed artery under the influence of body acceleration

    CERN Document Server

    Shit, G C

    2012-01-01

    With an aim to investigate the effect of externally imposed body acceleration and magnetic field on pulsatile flow of blood through an arterial segment having stenosis is under consideration in this paper. The flow of blood is presented by a unsteady micropolar fluid and the heat transfer characteristics have been taken into account. The non-linear equations that governing the flow are solved numerically using finite difference technique by employing a suitable coordinate transformation. The numerical results have been observed for axial and microrotation component of velocity, fluid acceleration, wall shear stress(WSS), flow resistance, temperature and the volumetric flow rate. It thus turns out that the rate of heat transfer increases with the increase of Hartmann number $H$, while the wall shear stress has a reducing effect on the Hartmann number $H$ and an enhancing effect on microrotation parameter $K$ as well as the constriction height $\\delta$.

  17. Glucoregulatory function of thyroid hormones: role of pancreatic hormones

    International Nuclear Information System (INIS)

    Glucose metabolism was investigated in humans before and 14 days after 300 micrograms L-thyroxine (T4)/day using a sequential clamp protocol during short-term somatostatin infusion (500 micrograms/h, 0-6 h) at euglycemia (0-2.5 h), at 165 mg/dl (2.5-6 h), and during insulin infusion (1.0 mU.kg-1.min-1, 4.5-6 h). T4 treatment increased plasma T4 (+96%) and 3,5,3'-triiodothyronine (T3, +50%), energy expenditure (+8%), glucose turnover (+32%), and glucose oxidation (Glucox +87%) but decreased thyroid-stimulating hormone (-96%) and nonoxidative glucose metabolism (Glucnonox, -30%) at unchanged lipid oxidation (Lipox). During somatostatin and euglycemia glucose production (Ra, -67%) and disposal (Rd, -28%) both decreased in euthyroid subjects but remained at -22% and -5%, respectively, after T4 treatment. Glucox (control, -20%; +T4, -25%) fell and Lipox increased (control, +42%; +T4, +45%) in both groups, whereas Glucnonox decreased before (-36%) but increased after T4 (+57%). During somatostatin infusion and hyperglycemia Rd (control, +144%; +T4, +84%) and Glucnonox (control, +326%; +T4, +233%) increased, whereas Glucox and Lipox remained unchanged. Insulin further increased Rd (+76%), Glucox (+155%), and Glucnonox (+50%) but decreased Ra (-43%) and Lipox (-43%). All these effects were enhanced by T4 (Rd, +38%; Glucox, +45%; Glucnonox, +35%; Ra, +40%; Lipox, +11%). Our data provide evidence that, in humans, T3 stimulates Ra and Rd, which is in part independent of pancreatic hormones

  18. Sequential growth hormone deficiency and acromegaly.

    OpenAIRE

    Heffernan, A.

    1988-01-01

    This is the case of a patient with a pituitary tumour presenting initially with growth hormone deficiency and requiring treatment with human growth hormone. Eight years later he represented with acromegaly. This sequence of events has not to my knowledge been reported previously.

  19. Recombinant Bovine Growth Hormone Criticism Grows.

    Science.gov (United States)

    Gaard, Greta

    1995-01-01

    Discusses concerns related to the use of recombinant bovine growth hormone in the United States and other countries. Analyses the issue from the perspectives of animal rights, human health, world hunger, concerns of small and organic farmers, costs to the taxpayer, and environmental questions. A sidebar discusses Canadian review of the hormone.…

  20. Clinical Trials in Male Hormonal Contraception

    OpenAIRE

    Nieschlag E

    2011-01-01

    Research has established the principle of hormonal male contraception based on suppression of gonadotropins and spermatogenesis. All hormonal male contraceptives use testosterone, but only in East Asian men can testosterone alone suppress spermatogenesis to a level compatible with contraceptive protection. In Caucasians, additional agents are required of which progestins are favored. Clinical trials concentrate on testosterone combined with norethisterone, desogestrel, etonogestrel or depo...