The usefulness of serum LH radioimmunoassay in the diagnosis of male hypogonadism

International Nuclear Information System (INIS)

Sobieszczyk, S.

1975-01-01

Serum LH was determined in a group of 56 males with gandal insufficiency. In this group were included 20 cases of Klinefelter's syndronme, 14 patients with total anterior pituitary insufficiency and 22 patients with eunuchoidism. Serum LH was also performed in a group of 50 healthy men. In the presented studies the LH radioimmunoassay with double antibodies was applied. In most cases of Klinefelter's syndrome the concentration of LH in serum was increased but in four subjects was normal. In total hypopituitarism serum LH was undetectable. Among patients with eunuchoidism the results of serum LH concentrations were different. Three cases with anorchia as well as four patients with testicular atrophy had elevated serum LH. In the other fifteen subjects serum LH was undetectable; hypogonadotropic eunuchoidism was diagnosed in these patients. (author)

The effect of restricted suckling on LH and ovarian steroids after ...

African Journals Online (AJOL)

time inseminations, and to decrease the incidence of 'short' oestrous cycles following GnRh.Tonic luteinizing hormone. (LH) levels, the release of LH in response to GnRh and oestro- .... fixed-time insemination was performed. The cows were rec- ..... growth rates in the calves between birth and 90 days were not affected by ...

Correlation between FSH, LH and prolactin serum levels. [Radioimmunoassay of hormones

Energy Technology Data Exchange (ETDEWEB)

Krause, W [Giessen Univ. (Germany, F.R.)

1978-01-01

In 188 males FSH, LH, and prolactin serum levels determined by radioimmunoassay from a single blood sample were found to be closely correlated. No correlation appeared to testosterone levels. The same correlation is observed, if serum levels of FSH, LH, and prolactin are measured after stimulation with LH-RH and TRH. In order to explain the close correlation, in five young men hormone levels were measured at 2-min-intervals over a period of 2 hours. Peaks of prolactin often correspond to those of FSH and LH, and a statistical correlation was found in two cases between FSH and prolactin. Results suggest a common releasing mechanism, which is superposed to the main mediating mechanism.

The involvement of dopaminergic system on LH secretion Nelore heifers Sistema dopaminérgico na secreção de LH de novilhas Nelore

Directory of Open Access Journals (Sweden)

Silvia Helena Venturoli Perri

2009-12-01

Full Text Available The aim of this study was to evaluate the response of sulpiride administration (dopamine D2 antagonist, 0.59 m/kg body weight, s.c. and blood collected every 15 min for 10 h thereafter on Luteinizing Hormone (LH secretion in B. indicus pre-pubertal heifers at 8, 12 and 16 month of age. LH was quantified by RIA, sensitivity (0.039 ng/ml and CV (15.51%. In heifers given sulpiride treatment didn’t differ (P≥0.05 in LH concentration, total secretion area, peak total area, number of peaks, area of highest secretion peak and time to highest peak occurrence and maximum LH secretion, from control group. The results suggest absence of dopamine D2 antagonist effect on LH secretion in pre-pubertal Nellore heifers, didn’t neurotransmitter participating on sexual maturation.O presente trabalho foi realizado com o objetivo de investigar a variação na secreção do Hormônio Luteinizante (LH em resposta ao tratamento com sulpiride, antagonista de receptor (D2 dopaminérgico, com administração de 0,59mg/kg, s.c. e colheita de amostras de sangue a cada 15min, por 10h. Foram utilizadas 10 novilhas da raça Nelore pré-púberes, aos 8, 12 e 16 meses de idade. A concentração de LH foi quantificada por radioimunoensaio, e o coeficiente de variação intra, o interensaio e a sensibilidade dos ensaios de LH foram respectivamente de: 11,86%; 15,51%; 0,039ng/mL. O tratamento com sulpiride não diferiu na concentração média de LH, área total de secreção de LH e picos, número de picos, área do maior pico, tempo necessário ao aparecimento do maior pico de secreção de LH e amplitude máxima de LH, em comparação ao grupo controle. Os resultados indicam ausência de efeito da dopamina, através de receptores D2, durante a fase pré-púbere, em novilhas da raça Nelore, o que sinaliza a não participação como neurotransmissora na secreção de LH durante o processo de maturação sexual.

release of lh in ewes treated with progestogen and oestrogen during

African Journals Online (AJOL)

ly in ewes after the use of progestogens to synchronise oestrus or to ... Two hours later a blood ... which received progesterone exhibited neither oestrus nor an LH surge ... been too short (Radford et al., 1970) or the fall in proges- terone titre ...

Operation and coupling of LH waves with the ITER-like wall at JET

International Nuclear Information System (INIS)

Kirov, K K; Mailloux, J; Arnoux, G; Baranov, Yu; Brix, M; Mayoral, M-L; Rimini, F; Stamp, M; Ekedahl, A; Goniche, M; Petrzilka, V; Jachmich, S; Ongena, J

2013-01-01

In this paper important aspects of the lower hybrid (LH) operation with the ITER-like wall (ILW) [1] at JET are reported. Impurity release during LH operation was investigated and it was found that there is no significant Be increase with LH power. The concentration of W was analysed in more detail and it was concluded that LH negligibly contributes to its increase. No cases of W accumulation in LH-only heating experiments were observed so far. LH wave coupling was studied and optimised to achieve the level of system performance similar to before ILW installation. Measurements by Li-beam were used to study systematic dependencies of the scrape-off layer (SOL) density on the gas injection rate from a dedicated gas introduction module and the LH power and launcher position. Experimental results are supported by SOL transport modelling. Observations of arcs in front of the LH launcher and hotspots on magnetically connected sections of the vessel are reported. Overall, a relatively trouble-free operation of the LH system up to 2.5 MW of coupled radio frequency power in L-mode plasma was achieved with no indication that the power cannot be increased further. (paper)

Glucocorticoid regulation of gonadotropin release from gonadotropes of ovine pituitary gland in vitro

International Nuclear Information System (INIS)

Nangalama, A.W.

1989-01-01

In order to understand the role of glucocorticoids in the regulation of gonadotropin release by the pituitary gland, the short-term effects of cortisol perifusion (1.5 h to 8 hrs) on GnRH-induced LH secretion were investigated. To determine the biochemical mechanism(s) by which cortisol can act to modulate GnRH-induced LH release, the interactions of cortisol and arachidonic acid in GnRH-stimulated LH release were examined. Cortisol perifusion for 1.5 hr had no effect on GnRH-induced LH release, but longer treatment periods (4 hr-8 hrs) significantly reduced GnRH-stimulated LH release (4.0 hr, p -4 M AA was administered for 20 min before a 10 min, 10 -10 M GnRH pulse. Like cortisol, chloroquine also failed to inhibit AA-induced LH release. Perifusion with 10 -6 M cortisol for 6.0 hours significantly (p 3 ]AA release 24% below the basal (100%) [ 3 H]AA secretion. Reduction of [ 3 H]AA release was accompanied by decreased GnRH-stimulated LH secretion

LH-RH binding to purified pituitary plasma membranes: absence of adenylate cyclase activation.

Science.gov (United States)

Clayton, R N; Shakespear, R A; Marshall, J C

1978-06-01

Purified bovine pituitary plasma membranes possess two specific LH-RH binding sites. The high affinity site (2.5 X 10(9) l/mol) has low capacity (9 X 10(-15) mol/mg membrane protein) while the low affinity site 6.1 X 10(5) l/mol) has a much higher capacity (1.1 X 10(-10) mol/mg). Specific LH-RH binding to plasma membranes is increased 8.5-fold during purification from homogenate whilst adenylate cyclase activity is enriched 7--8-fold. Distribution of specific LH-RH binding to sucrose density gradient interface fractions parallels that of adenylate cyclase activity. Mg2+ and Ca2+ inhibit specific [125I]LH-RH binding at micromolar concentrations. Synthetic LH-RH, up to 250 microgram/ml, failed to stimulate adenylase cyclase activity of the purified bovine membranes. Using a crude 10,800 g rat pituitary membrane preparation, LH-RH similarly failed to activate adenylate cyclase even in the presence of guanyl nucleotides. These data confirm the presence of LH-RH receptor sites on pituitary plasma membranes and suggest that LH-RH-induced gonadotrophin release may be mediated by mechanisms other than activation of adenylate cyclase.

Distribution of rhodopin and spirilloxanthin between LH1 and LH2 complexes when incorporating carotenoid mixture into the membrane of purple sulfur bacterium Allochromatium minutissimum in vitro.

Science.gov (United States)

Bolshakov, M A; Ashikhmin, A A; Makhneva, Z K; Moskalenko, A A

2016-11-01

Carotenoid mixture enriched by rhodopin and spirilloxanthin was incorporated in LH2 and LH1 complexes from Allochromatium (Alc.) minutissimum in vitro. The maximum incorporating level was ~95%. Rhodopin (56.4%) and spirilloxanthin (13.8%) were incorporated into the LH1 complex, in contrast to the control complex, which contained primarily spirilloxanthin (66.8%). After incorporating, the LH2 complex contained rhodopin (66.7%) and didehydrorhodopin (14.6%), which was close to their content in the control (67.4 and 20.5%, respectively). Thus, it was shown that carotenoids from the total pool are not selectively incorporated into LH2 and LH1 complexes in vitro in the proportion corresponding to the carotenoid content in the complexes in vivo.

LH2 Airbus studies

International Nuclear Information System (INIS)

Anon.

1992-01-01

The scope of work of the WP covers the 'Assessment of realistic prospects of LH 2 -usage in civil aviation', in detail: - Operational scenario for western Europe, - LH 2 cost development, - Investigations on a/c design and cryo systems, - Environmental impact of LH 2 -aircraft, - Cost estimate, - The way to a LH 2 fuelled aircraft. (orig.)

Role of calcium in gonadotropin releasing hormone-induced luteinizing hormone secretion from the bovine pituitary

International Nuclear Information System (INIS)

Kile, J.P.

1986-01-01

The hypothesis was tested that GnRH acts to release LH by increasing calcium uptake by gonadotroph which in turn stimulates calcium-calmodulin activity and results in LH release from bovine pituitary cells as it does in the rat. Pituitary glands of calves (4-10 months of age) were enzymatically dispersed (0.2% collagenase) and grown for 5 days to confluency in multiwell plates (3 x 10 5 /well). Cells treated with GnRH Ca ++ ionophore A23187, and ouabain all produced significant releases of LH release in a pronounced all or none fashion, while thorough washing of the cells with 0.5 mM EGTA in Ca ++ -free media prevented the action of GnRH. GnRH caused a rapid efflux of 45 Ca ++ . Both GnRH-stimulated 45 Ca efflux and LH release could be partially blocked by verapamil GnRH-induced LH release could also be blocked by nifedipine and tetrodotoxin, although these agents did not affect 45 Ca efflux. The calmodulin antagonists calmidazolium and W7 were found to block GnRH induced LH release, as well as LH release induced by theophylline, KC PGE 2 and estradiol. These data indicated that: (1) calcium is required for GnRH action, but extracellular Ca ++ does not regulate LH release; (2) GnRH elevates intracellular Ca ++ by opening both voltage sensitive and receptor mediated Ca ++ channels; (3) activation of calmodulin is one mechanism involved in GnRH-induced LH release

On the evocability of a positive oestrogen feedback action on LH secretion in transsexual men and women.

Science.gov (United States)

Dörner, G; Rohde, W; Seidel, K; Haas, W; Schott, G S

1976-03-01

In transsexual men with homosexual behaviour and intact testicular function, as well as in homosexual men with normal gender identity, following a negative oestrogen feedback effect a delayed positive oestrogen feedback action on LH secretion was evoked. By contrast, in transsexual men with hypo- or asexuality and intact testes or hypergonadotrophic hypo- or agonadism, as well as in heterosexual men with normal gender identity, a negative oestrogen feedback effect was not followed by a positive feedback action on LH release. In transsexual women with homosexual behaviour and oligo- and/or hypomenorrhoea, only a weak or at best moderate positive oestrogen feedback action on LH release was evocable, similarly as in castrated and oestrogen-primed heterosexual men. By contrast, in a transsexual woman with bisexual behaviour and eumenorrhoea, a strong positive oestrogen feedback action on LH secretion was evocable, as well as in heterosexual women with normal gender identity.

Safety Precautions for Total Release Foggers

Science.gov (United States)

Total release foggers, also known as bug bombs, are pesticide products containing aerosol propellants that release their contents at once to fumigate an area. They can pose a hazard if used incorrectly. Find safety information and videos on this page.

Suboptimal response to GnRHa long protocol is associated with a common LH polymorphism

DEFF Research Database (Denmark)

Alviggi, C; Clarizia, R; Pettersson, K

2011-01-01

The aim of this observational preliminary trial was to estimate the association between the most common polymorphism of LH (LH-β variant: v-βLH), with different profiles of ovarian response to recombinant human FSH (rhFSH). A total of 60 normogonadotrophic patients undergoing a gonadotrophin-rele...

Production of specific antisera for radioimmunoassay of human luteinizing hormone (LH) in the presence of human chorionic gonadotropin (hCG)

International Nuclear Information System (INIS)

Thorell, J.I.; Jeppsson, S.; Holmstrom, B.

1976-01-01

A specific radioimmunoassay for LH, which measures plasma LH in the presence of human chorionic gonadotropin (hCG) is described. Rabbits were immunized with highly purified native LH. One of the antisera with a difference in its reactivity against LH and hCG was further purified by affinity chromatography on a column with hCG coupled to Sepharose 4B. The adsorbed antiserum and 125 I-LH was used in a double antibody assay. The LH standard (MRC/68/40) efficiently inhibited the binding of 125 I-LH, and the standard curve showed a sensitivity of 0.5 ng/ml in the sample. hCG up to 10,000 ng/ml did not inhibit the binding of 125 I-LH. The plasma level of LH in pregnant women in the first trimester was low (1.3 +- 0.1 ng/ml). When LH was measured in fertile or menopausal women with or without stimulation with LH/FSH releasing hormone (LH-RH)/sup x/ the results agreed to those found with our conventional LH-assay based on antiserum against hCG

Correlation between LH secretion in castrated rats with cellular proliferation and synthesis of DNA in the anterior pituitary gland.

Science.gov (United States)

Romano, M I; Machiavelli, G A; Pérez, R L; Carricarte, V; Burdman, J A

1984-07-01

The relationship between the release of LH and the synthesis of DNA was studied in the anterior pituitary gland of castrated rats. Cell types were characterized immunocytochemically. Castration significantly (P less than 0.01) increased the concentration of LH in serum (1326%) and the incorporation of [3H]thymidine into pituitary DNA (72%). This was accompanied by an increment in the activity of the enzyme DNA polymerase-alpha (58%) and in the number of mitoses (from 2 +/- 0.1/mm2 in intact rats to 21 +/- 0.8/mm2 15 days after castration). Only 20% of the mitoses found in the pituitary gland of castrated rats were positively stained with the antiserum against the beta-subunit of LH. The other 80% did not stain either with LH antiserum or with antisera against the other pituitary hormones. There was a significant (P less than 0.01) increase in the number of LH cells in castrated rats (48%). All the changes produced in the anterior pituitary gland after castration were prevented by the administration of dihydrotestosterone. The results demonstrate that a stimulation of LH release is followed by an increase of DNA synthesis and cell proliferation of gonadotrophs in the anterior pituitary gland.

Maternal postpartum learned helplessness (LH) affects maternal care by dams and responses to the LH test in adolescent offspring.

Science.gov (United States)

Kurata, Akiko; Morinobu, Shigeru; Fuchikami, Manabu; Yamamoto, Shigeto; Yamawaki, Shigeto

2009-06-01

It is known that the early environment affects the mental development of rodent and human offspring. However, it is not known specifically whether a postpartum depressive state influences the depressive state in offspring. Using learned helplessness (LH) in rats as an animal model of depression, we examined the influence of maternal postpartum LH on responses to the LH test of offspring. Dam rats were judged as LH or non-helpless (nLH) on postnatal days (PN) 2-3, and maternal behavior was recorded during PN2-14. On PN 45-46, offspring were subjected to the LH test. Plasma corticosterone (CORT) levels, hippocampal levels of glucocorticoid receptor (GR) and brain-derived neurotrophic factor (BDNF) mRNA were measured before and after the LH test in offspring. Active nursing in LH dams was significantly lower than that in nLH dams. Susceptibility to LH in the offspring of LH dams was significantly higher than in those of nLH dams, and was negatively correlated with active nursing by LH dams. The GR mRNA levels before and after the LH test were lower in the offspring of LH dams than in those of nLH dams, and the reduced basal GR mRNA and protein might have resulted in the higher CORT response after the LH test. There was no significant difference in BDNF mRNA in the offspring of LH and nLH dams. These findings suggest that early postpartum LH decreased active nursing and increased depression-like behavior in the adolescent offspring via dysfunction of the hypothalamic-pituitary-adrenal axis.

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

International Nuclear Information System (INIS)

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

1990-01-01

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

Energy Exchange Dynamics across L-H transitions in NSTX

Science.gov (United States)

Diallo, Ahmed

2017-10-01

H-mode is planned for future devices such as ITER, and is preceded by a low (L) to high (H) transition. A key question remains. What is the mechanism behind the L-H transition? Most theoretical descriptions of the L-H transition are based on the shear of the radial electric field and coincident ExB poloidal flow shear, which is thought to be responsible for the onset of the anomalous transport suppression that leads to the L-H transition. This talk will focus on the analysis of the flow dynamics across the L-H transition in NSTX. We analyze the L-H transition dynamics using the velocimetry of 2D edge turbulence data from gas-puff imaging (GPI). We determine the velocity components at the edge across the L-H transition for 17 discharges with three types of heating power (NBI, ohmic, and RF). Using a reduced model equation of edge flows and turbulence, the energy transfer dynamics is compared with the turbulence depletion hypothesis of the predator-prey model. In order for Reynolds work to suppress the turbulence, it must deplete the total turbulent free energy, including the thermal free-energy term. For this to occur, the increase in kinetic energy in the mean flow over the L-H transition must be comparable to the pre-transition thermal free energy. However, this ratio was found to be of order 10-2. Although there are significant simplifications in the theoretical model, they are unlikely to cause inaccuracy by two orders of magnitude, suggesting that direct turbulence depletion by the Reynolds work may not be large enough to explain the L-H transition on NSTX, contrary to the predator-prey model. This work is supported by the US DOE Contract No. DE-AC02-09CH11466.

Influence of bovine LH tracer quality on levels of LH in GnRH-treated cows

International Nuclear Information System (INIS)

Madej, A.; Hallin, P.; Madej, M.; Seguin, B.; Edqvist, L.E.

1989-01-01

Chromatography of 125I-bovine LH (LER-1716-2 and USDA-I-1) by means of anion exchange high performance liquid chromatography (HPLC) revealed two main peaks of radioactivity regardless as to whether or not the tracer was initially purified on cellulose CF11. The content of radioactivity in the first peak tended to increase as the storage time of the bLH preparation, either before or after iodination, increased. The first peak of radioactivity after HPLC fractionation either with or without cellulose adsorption consisted of material with low binding ability to bLH antiserum (6.9% +/- 0.5 and 13.0% +/- 1.0, respectively) and high binding ability to ovine LH alpha antiserum (51.0% +/- 2.7 and 35.2% +/- 3.6, respectively). The average ratio of alpha-subunit immuno-reactivity to 125I-bLH immunoreactivity in this material was 7.4 +/- 0.1 and 2.7 +/- 0.2, respectively (P less than 0.001). Peaks in 125I-bLH radioactivity and 125I-bLH immunoreactivity had different elution times. Radioimmunoassays with tracers obtained from fractions derived from the first radioactive peak after HPLC chromatography (i.e. 125I-bLH-LER-1716-2) both with and without cellulose adsorption, yielded significantly lower mean plasma LH levels in GnRH-treated cows compared with the control tracer routinely purified only on cellulose CF11 (e.g. 5.7 vs. 8.2 micrograms/; 4.6 vs. 8.2 micrograms/l). Plasma LH levels in GnRH-treated cows were significantly (P less than 0.001) lower as measured by radioimmunoassay utilizing 125I-USDA-blH-I-1 tracers than by radioimmunoassays utilizing 125I-blH-LER-1716-2 tracers (i.e. either Y = 0.17 + 0.75X or Y = 1.18 + 0.60X)

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

International Nuclear Information System (INIS)

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

1987-01-01

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

Proinflammatory Cytokine Infusion Attenuates LH's Feedforward on Testosterone Secretion: Modulation by Age.

Science.gov (United States)

Veldhuis, Johannes; Yang, Rebecca; Roelfsema, Ferdinand; Takahashi, Paul

2016-02-01

In the experimental animal, inflammatory signals quench LH's feedforward drive of testosterone (T) secretion and appear to impair GnRH-LH output. The degree to which such suppressive effects operate in the human is not known. To test the hypothesis that IL-2 impairs LH's feedforward drive on T and T's feedback inhibition of LH secretion in healthy men. Mayo Center for Translational Science Activities. A total of 35 healthy men, 17 young and 18 older. Randomized prospective double-blind saline-controlled study of IL-2 infusion in 2 doses with concurrent 10-minute blood sampling for 24 hours. Deconvolution analysis of LH and T secretion. After saline injection, older compared with young men exhibited reduced LH feedforward drive on T secretion (P enforces biochemical hypogonadism, viz, combined feedforward block and feedback amplification; and 2) unequal absolute inhibition of T and LH secretion by IL-2 in young and older men. These outcomes establish that the male gonadal axis is susceptible to dual-site suppression by a prototypic inflammatory mediator. Thus, we postulate that selected ILs might also enforce male hypogonadism in chronic systemic inflammation.

Adrenergic system participation on LH secretion in pre-pubertal Nelore heifers Participação do sistema adrenérgico na secreção de LH, em novilhas nelores

Directory of Open Access Journals (Sweden)

Guilherme Paula Nogueira

2008-12-01

Full Text Available The aim of this study was to evaluate the response of clonidine administration (alfa-adrenoceptor agonist, 10g/kg body weight, i.v. and blood collected every 15 min for 4 h thereafter on luteinizing hormone (LH secretion in B. indicus pre-pubertal heifers at 8, 12 e 15 months of age. LH was quantified by RIA, sensitivity (0.05 ng/mL and coefficient of variation (20.39%. Alfa-adrenoceptor action (clonidine reduced (P<0,05 basal LH and time to greatest peak occurrence at 15 months-old and increased (P>0,05 peak total area and area of highest peak of LH secretion to 8 months-old. The results suggest reduced hypothalamic sensibility by gonadal steroid in pre-pubertal Nelore heifer maturation sexual and clonidine neurotransmitter participation, either stimulating or inhibiting LH secretion.Objetivou-se com este trabalho investigar a variação na secreção do hormônio luteinizante (LH em resposta ao tratamento com clonidina (agonista alfa-adrenérgico, 10µg/kg, i.v., amostras 15 min por 4h, em novilhas da raça Nelore pré-púberes aos 8, 12 e 15 meses de idade. A concentração de LH foi quantificada por radioimunoensaio, sensibilidade de 0,05 ng/mL e coeficiente de variação de 20,39%. A ativação de receptores alfa-adrenérgicos por intermédio da clonidina diminuiu (P<0,05 a concentração de LH e o tempo necessário para o aparecimento do maior pico de LH aos 15 meses de idade e aumentou (P>0,05 a área total e área do maior pico de secreção de LH aos 8 meses de idade. Os resultados indicam diminuição da sensibilidade do hipotálamo aos esteróides gonadais durante o processo de maturação sexual nas novilhas da raça Nelore e a participação da clonidina como neurotransmissora.

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

Energy Technology Data Exchange (ETDEWEB)

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

1990-12-01

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

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

Science.gov (United States)

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

1990-06-01

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

Proinflammatory Cytokine Infusion Attenuates LH's Feedforward on Testosterone Secretion: Modulation by Age

Science.gov (United States)

Yang, Rebecca; Roelfsema, Ferdinand; Takahashi, Paul

2016-01-01

Context: In the experimental animal, inflammatory signals quench LH's feedforward drive of testosterone (T) secretion and appear to impair GnRH-LH output. The degree to which such suppressive effects operate in the human is not known. Objective: To test the hypothesis that IL-2 impairs LH's feedforward drive on T and T's feedback inhibition of LH secretion in healthy men. Setting: Mayo Center for Translational Science Activities. Patients or Other Participants: A total of 35 healthy men, 17 young and 18 older. Interventions: Randomized prospective double-blind saline-controlled study of IL-2 infusion in 2 doses with concurrent 10-minute blood sampling for 24 hours. Main Outcome Measures: Deconvolution analysis of LH and T secretion. Results: After saline injection, older compared with young men exhibited reduced LH feedforward drive on T secretion (P feedback inhibition of LH secretion (P feedforward onto T secretion declined markedly especially in young subjects (P feedback on LH secretion especially in older volunteers. Conclusion: This investigation confirms combined feedforward and feedback deficits in older relative to young men given saline and demonstrates 1) joint mechanisms by which IL-2 enforces biochemical hypogonadism, viz, combined feedforward block and feedback amplification; and 2) unequal absolute inhibition of T and LH secretion by IL-2 in young and older men. These outcomes establish that the male gonadal axis is susceptible to dual-site suppression by a prototypic inflammatory mediator. Thus, we postulate that selected ILs might also enforce male hypogonadism in chronic systemic inflammation. PMID:26600270

The Association Between LH Serum Levels at the time of hCG Injection and Clinical Pregnancy during IVF

Directory of Open Access Journals (Sweden)

Budi Wiweko

2015-12-01

Full Text Available Some studies showed that recombinant follicle stimulating hormone (r-FSH administration without LH supplementation has a good success rate on in vitro fertilization (IVF. However, LH role in IVF has been controversial. This study was conducted to evaluate the association between serum LH levels at the time of hCG injection and clinical pregnancy during IVF. This retrospective study included 136 patients underwent long protocol IVF from January 2005 to December 2009 in Yasmin Clinic, Cipto Mangunkusumo Hospital, Jakarta. The controlled ovarian hyper-stimulation protocol used in this study was gonadotropin-releasing hormone (GnRH agonist and r-FSH.  Serum LH level was measured on the day of hCG administration and the outcome evaluated was the clinical pregnancy following IVF cycles. There were 32 IVF cycles resulted in pregnancy out of 136 cycles (23.5%. There was significant difference between serum LH levels on the day of hCG administration and clinical pregnancy outcome (p=0.036. LH serum level cut-off value of ≥1.050 IU/l was the best value to predict pregnancy outcome with 62.5% sensitivity, 59.4% specificity, 83.3% positive predictive value, and 32.76% negative predictive value. It was concluded that there was an association between serum LH levels at the time of hCG injection and clinical pregnancy during IVF. Keywords: IVF cycles, LH levels serum, hCG administration   Hubungan Kadar LH saat Penyuntikan hCG dengan Kejadian Kehamilan pada Fertilisasi In vitro Abstrak Pemberian follicles stimulating hormone rekombinan (r-FSH tanpa suplementasi LH memiliki tingkat keberhasilan fertilisasi in vitro (FIV yang baik namun, peran LH pada FIV masih kontroversial. Tujuan penelitian ini adalah untuk mengevaluasi hubungan antara kadar serum LH pada hari penyuntikan hCG dengan kehamilan klinis selama FIV. Penelitian retrospektif ini melibatkan 136 perempuan yang menjalani FIV siklus pertama dengan protokol panjang mulai bulan Januari 2005 sampai

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

International Nuclear Information System (INIS)

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

1986-01-01

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

Direct Visualization of Exciton Reequilibration in the LH1 and LH2 Complexes of Rhodobacter sphaeroides by Multipulse Spectroscopy

NARCIS (Netherlands)

Cohen Stuart, T.A.; Vengris, M.; Novoderezhkin, V.I.; Cogdell, R.J.; Hunter, C.N.; van Grondelle, R.

2011-01-01

The dynamics of the excited states of the light-harvesting complexes LH1 and LH2 of Rhodobacter sphaeroides are governed, mainly, by the excitonic nature of these ring-systems. In a pump-dump-probe experiment, the first pulse promotes LH1 or LH2 to its excited state and the second pulse dumps a

Intranasal LH-RH treatment of cryptorchidism. A clinical trial and 5 years follow-up

DEFF Research Database (Denmark)

Thorup, Jørgen Mogens; Mauritzen, K; Skakkebaek, N E

1987-01-01

The effect of intranasal LH-RH on cryptorchidism was investigated in 45 prepubertal boys with 68 undescended testes. A daily dose of 1.2 mg LH-RH was given for 4 weeks. A total of 16 testes (24%) descended. Follow-up examination 5 years later showed that relapse had occurred in two cases. Fifty......-two testes did not descend during the LH-RH treatment. However, seven of these testes descended spontaneously during puberty. So far surgical treatment has been carried out in 39 of the remaining 45 testes. Anatomical anomalies (ectopic position of the testis, open processus vaginalis, abnormal epididymis......) explained the failure of LH-RH to cause descent in the majority of the surgically treated cases....

LH2 airport requirements study

Science.gov (United States)

Brewer, G. D. (Editor)

1976-01-01

A preliminary assessment of the facilities and equipment which will be required at a representative airport is provided so liquid hydrogen LH2 can be used as fuel in long range transport aircraft in 1995-2000. A complete facility was conceptually designed, sized to meet the projected air traffic requirement. The facility includes the liquefaction plant, LH2, storage capability, and LH2 fuel handling system. The requirements for ground support and maintenance for the LH2 fueled aircraft were analyzed. An estimate was made of capital and operating costs which might be expected for the facility. Recommendations were made for design modifications to the reference aircraft, reflecting results of the analysis of airport fuel handling requirements, and for a program of additional technology development for air terminal related items.

Quick look report for Semiscale Mod-2C experiments S-LH-1 and S-LH-2

International Nuclear Information System (INIS)

Loomis, G.G.; Streit, J.E.

1985-05-01

Results from a preliminary analysis of Semiscale Tests S-LH-1 and S-LH-2 are presented. Both experiments were 5%, cold leg, centerline pipe break, loss-of-coolant accident simulations with only the downcomer to upper head bypass flow different. Test S-LH-1 had a bypass flow of 0.9% of core flow and Test S-LH-2 had a 3% bypass flow. Phenomena of interest included two core liquid level depressions with minor core rod temperature excursions. The first liquid level depression was induced by a manometric balance formed by a liquid seal in the pump suctions of both loops and the second level depletion was due to core liquid boiloff. Pump suction seal clearing mitigated the first core heatup and accumulator flow refilled the core to terminate the second core heatup. Comparisons are made between a pretest RELAP5 calculation and S-LH-1 data. RELAP5 calculated the manometric core level depression but not the core rod heatups

A disordered polaron model for polarized fluorescence excitation spectra of LH1 and LH2 bacteriochlorophyll antenna aggregates

International Nuclear Information System (INIS)

Trinkunas, Gediminas; Freiberg, Arvi

2006-01-01

Excitonic polarons in antenna complexes are subject to static lattice disorder. A model has been developed to analyze polarized fluorescence excitation spectra of circular light-harvesting complexes from purple photosynthetic bacteria containing bacteriochlorophyll as the main photoactive pigment that includes both diagonal (energetic) and off-diagonal (structural) disorders. Essential differences of disorder realizations seem to exist between the core LH1 and peripheral LH2 complexes from the bacterium Rhodobacter sphaeroides. The disorder in LH1 appears to be dominated by the structural disorder, while that in LH2, by energetic one. These differences may be due to relatively bigger size of the LH1 complex and, consequently, with its enhanced structural flexibility

Evaluation of the double antibody - solid phase radioimmunoassay technique in plasma LH and FSH and urinary LH measurements

International Nuclear Information System (INIS)

Karonen, S.-L.; Laehteenmaeki, P.; Hohenthal, U.; Adlercreutz, H.

1978-01-01

Double antibody phase (DASP) radioimmunoassay methods for plasma LH and FSH and urinary LH were developed and carefully evaluated as to their reliability and practicability. The peptide hormones were iodinated enzymatically with immobilized lactoperoxidase which resulted in pure and stable products of unchanged immunoreactivity. The sensitivities of these assay methods are 0.02, 0.17 and 0.20 mlU/tube for plasma LH (MRC 68/40) and FSH (MRC 68/39) and urinary LH (IRP-HMG, urinary), respectively. Interassay coefficients of variation obtained over a 6-18 month period were 14.2, 14.7 and 12.8%, respectively. The latter values for plasma LH and FSH assays were obtained from one level pool samples, and the value for urinary LH is the mean of those obtained from two pools of different levels. Plasma reference values for LH and FSH obtained using these methods are about 1.8-2.9 times higher than those cited for other types of radioimmunoassay. However, the values obtained for LH in urine are similar to those reported in the literature. It is suggested that the DASP technique is less influenced by interference from plasma proteins and because of this gives plasma values closer to the true ones. It is concluded that the methods are well suited for use as routine clinical assays in laboratories with a high work load. (Auth.)

Radioimmunoassay of pituitary LH in fetal rabbit

International Nuclear Information System (INIS)

Veyssiere, Georges; Berger, Michel; Jean-Faucher, Christiane; Turckheim, Marc de; Jean, Claude

1981-01-01

LH was measured by radioimmunology from the 18th day of gestation to birth in 318 male and female pituitary glands. LH was first detectable in the pituitary of 19 day old fetuses of both sexes. In both sexes pituitary LH levels increased from the 18th to the 31st day of gestation with a marked acceleration from the 24th day. LH pituitary levels were not sex-dependent [fr

Empirical Profiling of Cold Hydrogen Plumes Formed from Venting Of LH2 Storage Vessels: Preprint

Energy Technology Data Exchange (ETDEWEB)

Buttner, William J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Rivkin, Carl H [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Schmidt, Kara [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Hartmann, Kevin S [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Wright, Hannah [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Weidner, Eveline [Joint Research Centre, Petten, the Netherlands; Ciotti, Michael [H2 Fueling and CIP Markets Engineering

2017-11-16

Liquid hydrogen (LH2) storage is a viable approach to assuring sufficient hydrogen capacity at commercial fuelling stations. Presently, LH2 is produced at remote facilities and then transported to the end-use site by road vehicles (i.e., LH2 tanker trucks). Venting of hydrogen to depressurize the transport storage tank is a routine part of the LH2 delivery process. The behaviour of cold hydrogen plumes has not been well-characterized because empirical field data is essentially non-existent. The NFPA 2 Hydrogen Storage Safety Task Group, which consists of hydrogen producers, safety experts, and CFD modellers, has identified the lack of understanding of hydrogen dispersion during LH2 venting of storage vessel as a critical gap for establishing safety distances at LH2 facilities, especially commercial hydrogen fuelling stations. To address this need, the NREL sensor laboratory, in collaboration with the NFPA 2 Safety Task Group developed the Cold Hydrogen Plume Analyzer to empirically characterize the hydrogen plume formed during LH2 storage tank venting. A prototype Analyzer was developed and field-deployed at an actual LH2 venting operation with critical findings that included: - H2 being detected as much as 2 m lower than the release point, which is not predicted by existing models - A small and inconsistent correlation between oxygen depletion and the hydrogen concentration - A negligible to non-existent correlation between in-situ temperature and the hydrogen concentration The Analyzer is currently being upgraded for enhanced metrological capabilities including improved real-time spatial and temporal profiling of the plume and tracking of prevailing weather conditions. Additional deployments are planned to monitor plume behaviour under different wind, humidity, and temperatures. This data will be shared with the NFPA 2 Safety Task Group and ultimately will be used support theoretical models and code requirements prescribed in NFPA 2.

Different serotonin receptor types participate in 5-hydroxytryptophan-induced gonadotropins and prolactin release in the female infantile rat.

Science.gov (United States)

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

1996-05-01

Serotonin (5-HT) receptors can be classified into at least three, possibly up to seven, classes of receptors. They comprise the 5-HT1, 5-HT2, and 5-HT3 classes, the "uncloned' 5-HT4 receptor and the recombinant receptors 5-ht5, 5-ht6 and 5-ht7. We investigated the role of different serotonin receptor types in a neuroendocrine response to the activation of the serotonergic system. Female immature rats were chosen as an experimental model as it has been shown that during the 3rd week of life, and not at later developmental stages, 5-hydroxytryptophan (5-HTP, a serotonin precursor) induces gonadotropin release in females and not in males. Besides, at this age, serotonin releases prolactin in both sexes. 5-HTP (50 mg/kg) released prolactin, luteinizing hormone (LH) and follicle-stimulating hormone (FSH) as expected. Ketanserin (5-HT2A antagonist) and methysergide (5-HT2C antagonist) blocked 5-HTP-induced prolactin release, but did not block the LH or FSH responses. Ondansetron (5-HT3 receptor antagonist) did not modify prolactin response to 5-HTP, whereas it blocked 5-HTP-induced LH and FSH release. Propranolol (5-HT1 and beta-adrenergic antagonist) blocked prolactin, LH and FSH release induced by 5-HTP. The 5-HT2C agonist 1-(3-chlorophenyl)piperazine dihydrochloride released prolactin, without modifying LH or FSH release. Methyl-quipazine and phenylbiguanide (5-HT3 agonists) increased both LH and FSH levels, without altering prolactin secretion. The present experiments indicate that serotonin acting at the 5-HT3 receptor mediates LH and FSH release in infantile female rats, whereas 5-HT2C or 2A receptor types participate in the release of prolactin at this age. 5-HT1 receptor type may be involved in the release of the three hormones, though a beta-adrenergic component of the response cannot be discarded.

Differential testosterone response to GnRH-induced LH release before and after musth in adult Asian elephant (Elephas maximus) bulls.

Science.gov (United States)

Somgird, Chaleamchat; Sripiboon, Supaphen; Mahasawangkul, Sittidet; Boonprasert, Khajohnpat; Brown, Janine L; Stout, Tom A E; Colenbrander, Ben; Thitaram, Chatchote

2016-04-15

Bull elephants exhibit marked increases in testosterone secretion during musth, and studies have shown a heightened sensitivity of the testis to GnRH-stimulated testosterone production in musth compared to nonmusth males. However, activity of the hypothalamo-pituitary-gonadal axis before or soon after musth has not been studied in detail. The aim of this study was to evaluate LH and testosterone responses to GnRH challenge in nine adult Asian elephant (Elephas maximus) bulls during three periods relative to musth: premusth, postmusth, and nonmusth. Bulls were administered 80 μg of a GnRH agonist, and blood was collected before and after injection to monitor serum hormone concentrations. The same bulls were injected with saline 2 weeks before each GnRH challenge and monitored using the same blood collection protocol. All bulls responded to GnRH, but not saline, with an increase in LH and testosterone during all three periods. The mean peak LH (1.76 ± 0.19 ng/mL; P elephants. Furthermore, although the hypothalamo-pituitary-gonadal axis is active throughout the year, the testis appears to be more responsive to LH in terms of testosterone production in the period leading up to musth, compared to the nonmusth and postmusth periods. This heightened sensitivity, perhaps as a result of LH receptor up-regulation, may prime the testis for maximal testosterone production, leading to the physiological and behavioral changes associated with musth. Copyright © 2016 Elsevier Inc. All rights reserved.

Effect of gas injection during LH wave coupling at ITER-relevant plasma-wall distances in JET

International Nuclear Information System (INIS)

Ekedahl, A; Goniche, M; Basiuk, V; Delpech, L; Imbeaux, F; Joffrin, E; Loarer, T; Rantamaeki, K; Mailloux, J; Alper, B; Baranov, Y; Beaumont, P; Corrigan, G; Erents, K; Hawkes, N; McDonald, D; Petrzilka, V; Granucci, G; Hobirk, J; Kirov, K

2009-01-01

Good coupling of lower hybrid (LH) waves has been demonstrated in different H-mode scenarios in JET, at high triangularity (δ ∼ 0.4) and at large distance between the last closed flux surface and the LH launcher (up to 15 cm). Local gas injection of D 2 in the region magnetically connected to the LH launcher is used for increasing the local density in the scrape-off layer (SOL). Reciprocating Langmuir probe measurements magnetically connected to the LH launcher indicate that the electron density profile flattens in the far SOL during gas injection and LH power application. Some degradation in normalized H-mode confinement, as given by the H98(y,2)-factor, could be observed at high gas injection rates in these scenarios, but this was rather due to total gas injection and not specifically to the local gas puffing used for LH coupling. Furthermore, experiments carried out in L-mode plasmas in order to evaluate the effect on the LH current drive efficiency, when using local gas injection to improve the coupling, indicate only a small degradation (ΔI LH /I LH ∼ 15%). This effect is largely compensated by the improvement in coupling and thus increase in coupled power when using gas puffing.

[Determining visual acuity with LH symbols and Landolt rings].

Science.gov (United States)

Gräf, M; Becker, R

1999-08-01

Lea (LH) symbols seem to be favourable for visual acuity assessment in childhood. The symbols of the LH test are well standardized and applicable to preschool children. We compared the visual acuity determined by LH single symbols (LH) and the acuity measured with the Landolt-C (LC). 138 cooperative subjects aged 7 to 91 years were examined. Their visual acuity was either normal or reduced due to various etiologies. Their refractive error was corrected. The monocular LH and LC were determined by a 3/4 criterion (study 1). In 19 healthy subjects aged 21 to 58 years, acuity was reduced stepwise by 5 different calibrated occlusives (study 2). A Lighthouse single symbol book (LH symbols) was used at a distance of 3 m. LC was determined at a distance of 5 m. The luminance of the test field was 180-200 cd/m2. The right eye of each patient and the amblyopic eye of the squinting patients was taken for statistical evaluation. The strabismic patients' interocular differences of LC and LH were compared. Within study 1, LC ranged from 0.02 to 2.0 and LH from 0.03 to 2.5. LH overestimated LC by 1.4 lines on an average (t-test p 1 line, 85.7% resp. 90% of the strabismic amblyopic patients with an interocular LC difference > 1 resp > 2 lines were detected. In study 2, LC ranged from 0.1 to 1.6, LH from 0.12 to 2.0. The mean difference LH-LC was 1.3 lines. The regression equation was lgLH = 0.91 lgLC + 0.08 (r = 0.95). LH symbols allow a reliable measurement of recognition acuity. Due to the design of the symbols, they are excellently suitable for application to preschool children. Age related normal values should be established. The systematic difference between the LC acuity and the LH acuity measured with the Lighthouse LH single symbol book by 1.4 lines has to be considered.

Suppression of LH during ovarian stimulation: analysing threshold values and effects on ovarian response and the outcome of assisted reproduction in down-regulated women stimulated with recombinant FSH.

Science.gov (United States)

Balasch, J; Vidal, E; Peñarrubia, J; Casamitjana, R; Carmona, F; Creus, M; Fábregues, F; Vanrell, J A

2001-08-01

It has been recently suggested that gonadotrophin-releasing hormone agonist down-regulation in some normogonadotrophic women may result in profound suppression of LH concentrations, impairing adequate oestradiol synthesis and IVF and pregnancy outcome. The aims of this study, where receiver-operating characteristic (ROC) analysis was used, were: (i) to assess the usefulness of serum LH measurement on stimulation day 7 (S7) as a predictor of ovarian response, IVF outcome, implantation, and the outcome of pregnancy in patients treated with recombinant FSH under pituitary suppression; and (ii) to define the best threshold value, if any, to discriminate between women with 'low' or 'normal' LH concentrations. A total of 144 infertile women undergoing IVF/intracytoplasmic sperm injection (ICSI) treatment were included. Seventy-two consecutive patients having a positive pregnancy test (including 58 ongoing pregnancies and 14 early pregnancy losses) were initially selected. As a control non-pregnant group, the next non-conception IVF/ICSI cycle after each conceptual cycle in our assisted reproduction programme was used. The median and range of LH values in non-conception cycles, conception cycles, ongoing pregnancies, and early pregnancy losses, clearly overlapped. ROC analysis showed that serum LH concentration on S7 was unable to discriminate between conception and non-conception cycles (AUC(ROC) = 0.52; 95% CI: 0.44 to 0.61) or ongoing pregnancy versus early pregnancy loss groups (AUC(ROC) = 0.59; 95% CI: 0.46 to 0.70). To assess further the potential impact of suppressed concentrations of circulating LH during ovarian stimulation on the outcome of IVF/ICSI treatment, the three threshold values of mid-follicular serum LH proposed in the literature (women with 'low' or 'normal' LH were applied to our study population. No significant differences were found with respect to ovarian response, IVF/ICSI outcome, implantation, and the outcome of pregnancy between 'low' and

Antidopaminergic-induced hypothalamic LHRH release and pituitary gonadotrophin secretion in 12 day-old female and male rats.

Science.gov (United States)

Lacau-Mengido, I M; Becú-Villalobos, D; Thyssen, S M; Rey, E B; Lux-Lantos, V A; Libertun, C

1993-12-01

In previous studies we have shown that the developing rat provides an interesting physiologic model in which the dopaminergic control of both LH and FSH is well defined in contrast to the controversial results obtained in adult rats. We wished to establish the role of testosterone in antidopaminergic induced gonadotrophins release in 12 day-old male and female rats, and evaluate the effect of antidopaminergic drugs at the hypothalamic level during this developmental stage. Haloperidol, an antidopaminergic drug, increased both LH and FSH in female 12 day-old rats but not in male littermates. The effect was blocked by bromocriptine and not by phentolamine indicating that haloperidol acted on the dopaminergic receptor, and that unspecific stimulation of the noradrenergic system was not involved. Haloperidol was ineffective when female rats were previously ovariectomized and injected with testosterone propionate at 9 days of age. If females were treated on the day of birth with testosterone propionate, haloperidol-induced FSH and LH release was also abolished. In control males haloperidol had no effect on the release of LH or FSH. But if males were orchidectomized at birth or at 9 days of age, haloperidol released both LH and FSH during the infantile period. In an attempt to establish the site of action of antidopaminergic drugs on gonadotrophin release, hypothalami (mediobasal and preoptic-suprachiasmatic area) from 12 day-old infant female rats were perifused with either haloperidol or domperidone (2*10(-6) M). Both drugs increased LHRH release into the perifusate. Besides haloperidol did not modify the release of LH or FSH from adenohypophyseal cells incubated in vitro. We therefore conclude that antidopaminergic-induced gonadotrophins release is modulated by serum testosterone concentrations, and that the site of action is probably the LHRH-secreting neuron of the hypothalamus.

Immunoreactive LH in long-term frozen human urine samples.

Science.gov (United States)

Singh, Gurmeet Kaur Surindar; Jimenez, Mark; Newman, Ron; Handelsman, David J

2014-04-01

Urine provides a convenient non-invasive alternative to blood sampling for measurement of certain hormones. Urinary luteinizing hormone (LH) measurements have been used for endocrinology research and anti-doping testing. However, the commercially available LH immunoassays are developed and validated for human blood samples but not urine so that LH assays intended for use with urine samples need thorough validation. Therefore, the present study evaluated the measurement of urinary LH immunoreactivity using previously validated immunofluorometric (IF) and immunochemiluminometric (ICL) LH assays after prolonged frozen storage. LH was measured in serial urine samples following administration of a single injection of one of two doses of recombinant human chorionic hormone (rhCG) with assays run at the end of study (2008) and again after four years of frozen (-20 °C) storage where samples were stored without adding preservatives. The ICL assay showed quantitatively reproducible LH measurements after prolonged -20 °C storage. However, the IF immunoassay gave consistently lower LH levels relative to ICL (2008) with a further proportionate reduction after four years of sample storage (2012). Yet, both the assays displayed similar patterns of the time-course of urine LH measurement both before and after four years of frozen storage. In conclusion, we found that both immunoassays are suitable for urinary LH measurements with ICL assay being more robust for quantitative urinary LH measurement such as for anti-doping purposes, whereas the IF could be applicable for research studies where urine LH levels are compared within-study but not in absolute terms. Copyright © 2013 John Wiley & Sons, Ltd.

(LH) secretion in fasted prepubertal ewes

African Journals Online (AJOL)

DR. NJ TONUKARI

2012-01-10

Jan 10, 2012 ... decreased luteinizing hormone (LH) secretion in fasted prepubertal ewes .... kisspeptin-10 injection could restore the baseline levels of. LH changed by ..... Terasawa E (2005). Role of GABA in the mechanism of the onset of.

Energy exchange dynamics across L-H transitions in NSTX

Science.gov (United States)

Diallo, A.; Banerjee, S.; Zweben, S. J.; Stoltzfus-Dueck, T.

2017-06-01

We studied the energy exchange dynamics across the low-to-high-confinement (L-H) transition in NSTX discharges using the gas-puff imaging (GPI) diagnostic. The investigation focused on the energy exchange between flows and turbulence to help clarify the mechanism of the L-H transition. We applied this study to three types of heating schemes, including a total of 17 shots from the NSTX 2010 campaign run. Results show that the edge fluctuation characteristics (fluctuation levels, radial and poloidal correlation lengths) measured using GPI do not vary just prior to the H-mode transition, but change after the transition. Using a velocimetry approach (orthogonal-dynamics programming), velocity fields of a 24× 30 cm GPI view during the L-H transition were obtained with good spatial (˜1 cm) and temporal (˜2.5 μs) resolutions. Analysis using these velocity fields shows that the production term is systematically negative just prior to the L-H transition, indicating a transfer from mean flows to turbulence, which is inconsistent with the predator-prey paradigm. Moreover, the inferred absolute value of the production term is two orders of magnitude too small to explain the observed rapid L-H transition. These discrepancies are further reinforced by consideration of the ratio between the kinetic energy in the mean flow to the thermal free energy, which is estimated to be much less than 1, suggesting again that the turbulence depletion mechanism may not play an important role in the transition to the H-mode. Although the Reynolds work therefore appears to be too small to directly deplete the turbulent free energy reservoir, order-of-magnitude analysis shows that the Reynolds stress may still make a non-negligible contribution to the observed poloidal flows.

Stability of integral membrane proteins under high hydrostatic pressure: the LH2 and LH3 antenna pigment-protein complexes from photosynthetic bacteria.

Science.gov (United States)

Kangur, Liina; Timpmann, Kõu; Freiberg, Arvi

2008-07-03

The bacteriochlorophyll a-containing LH2 and LH3 antenna complexes are the integral membrane proteins that catalyze the photosynthetic process in purple photosynthetic bacteria. The LH2 complex from Rhodobacter sphaeroides shows characteristic strong absorbance at 800 and 850 nm due to the pigment molecules confined in two separate areas of the protein. In the LH3 complex from Rhodopesudomonas acidophila the corresponding bands peak at 800 and 820 nm. Using the bacteriochlorophyll a cofactors as intrinsic probes to monitor local changes in the protein structure, we investigate spectral responses of the antenna complexes to very high hydrostatic pressures up to 2.5 GPa when embedded into natural membrane environment or extracted with detergent. We first demonstrate that high pressure does induce significant alterations to the tertiary structure of the proteins not only in proximity of the 800 nm-absorbing bacteriochlorophyll a molecules known previously (Gall, A.; et al. Biochemistry 2003, 42, 13019) but also of the 850 nm- and 820 nm-absorbing molecules, including breakage of the hydrogen bond they are involved in. The membrane-protected complexes appear more resilient to damaging effects of the compression compared with the complexes extracted into mixed detergent-buffer environment. Increased resistance of the isolated complexes is observed at high protein concentration resulting aggregation as well as when cosolvent (glycerol) is added into the solution. These stability variations correlate with ability of penetration of the surrounding polar solvent (water) into the hydrophobic protein interiors, being thus the principal reason of the pressure-induced denaturation of the proteins. Considerable variability of elastic properties of the isolated complexes was also observed, tentatively assigned to heterogeneous protein packing in detergent micelles. While a number of the isolated complexes release most of their bacteriochlorophyll a content under high pressure

Ground-State Electronic Structure of RC-LH1 and LH2 Pigment Assemblies of Purple Bacteria via the EBF-MO Method.

Science.gov (United States)

Shrestha, Kushal; Jakubikova, Elena

2015-08-20

Light-harvesting antennas are protein-pigment complexes that play a crucial role in natural photosynthesis. The antenna complexes absorb light and transfer energy to photosynthetic reaction centers where charge separation occurs. This work focuses on computational studies of the electronic structure of the pigment networks of light-harvesting complex I (LH1), LH1 with the reaction center (RC-LH1), and light-harvesting complex II (LH2) found in purple bacteria. As the pigment networks of LH1, RC-LH1, and LH2 contain thousands of atoms, conventional density functional theory (DFT) and ab initio calculations of these systems are not computationally feasible. Therefore, we utilize DFT in conjunction with the energy-based fragmentation with molecular orbitals method and a semiempirical approach employing the extended Hückel model Hamiltonian to determine the electronic properties of these pigment assemblies. Our calculations provide a deeper understanding of the electronic structure of natural light-harvesting complexes, especially their pigment networks, which could assist in rational design of artificial photosynthetic devices.

Radioimmunoassay for luteinizing hormone releasing hormone in plasma

International Nuclear Information System (INIS)

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

1975-01-01

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

[Preparation of hydrophilic matrix sustained release tablets of total lactones from Andrographis paniculata and study on its in vitro release mechanism].

Science.gov (United States)

Xu, Fang-Fang; Shi, Wei; Zhang, Hui; Guo, Qing-Ming; Wang Zhen-Zhong; Bi, Yu-An; Wang, Zhi-Min; Xiao, Wei

2015-01-01

In this study, hydrophilic matrix sustained release tablets of total lactones from Andrographis paniculata were prepared and the in vitro release behavior were also evaluated. The optimal prescription was achieved by studying the main factor of the type and amount of hydroxypropyl methylcellulose (HPMC) using single factor test and evaluating through cumulative release of three lactones. No burst drug release from the obtained matrix tablets was observed. Drug release sustained to 14 h. The release mechanism of three lactones from A. paniculata was accessed by zero-order, first-order, Higuchi and Peppas equation. The release behavior of total lactones from A. paniculata was better agreed with Higuchi model and the drug release from the tablets was controlled by degradation of the matrix. The preparation of hydrophilic matrix sustained release tablets of total lactones from A. paniculata with good performance of drug release was simple.

Avian LH and FSH: comparison of several radioimmunoassays

International Nuclear Information System (INIS)

Goldsmith, A.R.; Follett, B.K.

1983-01-01

Comparisons were made between various LH and FSH radioimmunoassays currently being used to measure avian hormones. The two LH assays were the homologous chicken system of Follett et al. (1972) and the turkey assay of Burke et al. (1979). These assays were also used in heterologous arrangement by interchanging the iodinated LH fractions and antisera. Five FSH assays were analyzed: two homologous chicken systems (Scanes et al., 1977; Sakai and Ishii, 1980) an assay based on mammalian materials (rat FSH and anti-ovine FSH antiserum, and one using labelled turkey FSH (Burke et al., 1979) with an anti-chicken FSH antiserum. The potencies of purified chicken and turkey gonadotrophin preparations and of a range of plasma samples from Japanese quail were measured in each assay. The two LH systems showed some degree of species specificity, such that chicken LH was more active than turkey LH in the chicken assay, whereas the reverse was true in the turkey LH assay. The potency estimates of the purified hormones in the various FSH assays were very consistent. The qualitative changes in plasma hormone levels were similar in all assays, although there were some differences in the magnitude of the responses

Melatonin and LH secretion patterns in pubertal boys

International Nuclear Information System (INIS)

Fevre, M.; Boyar, R.M.; Rollag, M.D.

1979-01-01

Plasma melatonin and LH were measured at 20 minute intervals for 24 hours in four normal pubertal boys. All four subjects showed a significant augmentation of LH and melatonin during nocturnal sleep. There was also a significant correlation between the LH and melatonin levels (p [fr

Radioimmunologic assessment of the level of circulating LH antibodies after passive immunization in the rat: relation to the level of LH secretion

International Nuclear Information System (INIS)

Morishige, W.K.; Billiar, R.B.; Rothchild, I.

1975-01-01

A double antibody radioimmunologic technique was used to estimate circulating levels of free LH antibodies (Ab) (i.e., Ab available for binding to radioiodinated rat LH in vitro) after a single injection of an equine antiserum to bovine LH (LH--AS) into cyclic (diestrus-l), early pregnant (d 6 or d 8), short-term (1 d) or long-term (12 d) ovariectomized, or 8-d hyopophysectomized female rats. In both cyclic and pregnant rats given 0.5 ml LH--AS SC the blood Ab levels peaked 1 to 2 days after injection and then decreased exponentially (half-time: 14.6 to 17.0 h) and equally; vaginal estrus also appeared in the cyclic and in the aborting pregnant rats on the 6th day, and ovulation on the 7th day after LH--AS treatment, when the blood levels had fallen to very low values. The rate of exponential decrease in blood Ab levels was not affected by other routes of administration (iv or ip) of LH--AS, or by SC doses of 1.0 or 0.25 ml, although the peak levels and their duration were related to dose and route of administration. Ovariectomy significantly increased the rate of exponential Ab decrease (half-time: 9.8 h in rats tested 12 days after operation) and hypophysectomy markedly diminished it (half-time: 63.0 h in rats tested 8 days after operation). Daily treatment of hypophysectomized rats with 20 μg/day of ovine LH from the time of LH-AS injection increased the rate of exponential Ab decrease to one approaching that of the intact rats (half-time: 20.5 h). Free LH antibodies thus seem to disappear from the circulation at a rate proportional to the amount of LH in the circulation. (U.S.)

Highly potent metallopeptide analogues of luteinizing hormone-releasing hormone

International Nuclear Information System (INIS)

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

1989-01-01

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

Overview of L-H power threshold studies in NSTX

International Nuclear Information System (INIS)

Maingi, R.; Biewer, T.M.; Kaye, S.M.; Bell, R.E.; Gates, D.A.; Gerhardt, S.P.; Hosea, J.; LeBlanc, B.P.; Mueller, D.; Stevenson, T.A.; Wilson, J.R.; Chang, C.S.; Park, G-Y.; Meyer, H.; Raman, R.; Sabbagh, S.A.

2010-01-01

A summary of results from recent L-H power threshold (P LH ) experiments in the National Spherical Torus Experiment is presented. First P LH (normalized linearly by plasma density) was found to be a minimum in double-null configuration, tending to increase as the plasma was shifted more strongly towards lower- or upper-single null configuration with either neutral beam or rf heating. The measured P LH /n e was comparable with neutral beam or rf heating, suggesting that rotation was not playing a dominant role in setting the value of P LH . The role of triangularity (δ bot ) in setting P LH /n e is less clear: while 50% less auxiliary heating power was required to access H-mode at low δ bot than at high δ bot , the high δ bot discharges had lower ohmic heating and higher dW/dt, leading to comparable loss of power over a range of δ bot . In addition, the dependences of P LH on the density, species (helium versus deuterium), plasma current, applied non-axisymmetric error fields and lithium wall conditioning are summarized.

Differences in Signal Activation by LH and hCG are Mediated by the LH/CG Receptor's Extracellular Hinge Region.

Science.gov (United States)

Grzesik, Paul; Kreuchwig, Annika; Rutz, Claudia; Furkert, Jens; Wiesner, Burkhard; Schuelein, Ralf; Kleinau, Gunnar; Gromoll, Joerg; Krause, Gerd

2015-01-01

The human lutropin (hLH)/choriogonadotropin (hCG) receptor (LHCGR) can be activated by binding two slightly different gonadotropic glycoprotein hormones, choriogonadotropin (CG) - secreted by the placenta, and lutropin (LH) - produced by the pituitary. They induce different signaling profiles at the LHCGR. This cannot be explained by binding to the receptor's leucine-rich-repeat domain (LRRD), as this binding is similar for the two hormones. We therefore speculate that there are previously unknown differences in the hormone/receptor interaction at the extracellular hinge region, which might help to understand functional differences between the two hormones. We have therefore performed a detailed study of the binding and action of LH and CG at the LHCGR hinge region. We focused on a primate-specific additional exon in the hinge region, which is located between LRRD and the serpentine domain. The segment of the hinge region encoded by exon10 was previously reported to be only relevant to hLH signaling, as the exon10-deletion receptor exhibits decreased hLH signaling, but unchanged hCG signaling. We designed an advanced homology model of the hormone/LHCGR complex, followed by experimental characterization of relevant fragments in the hinge region. In addition, we examined predictions of a helical exon10-encoded conformation by block-wise polyalanine (helix supporting) mutations. These helix preserving modifications showed no effect on hormone-induced signaling. However, introduction of a structure-disturbing double-proline mutant LHCGR-Q303P/E305P within the exon10-helix has, in contrast to exon10-deletion, no impact on hLH, but only on hCG signaling. This opposite effect on signaling by hLH and hCG can be explained by distinct sites of hormone interaction in the hinge region. In conclusion, our analysis provides details of the differences between hLH- and hCG-induced signaling that are mainly determined in the L2-beta loop of the hormones and in the hinge

Monomeric RC-LH1 core complexes retard LH2 assembly and intracytoplasmic membrane formation in PufX-minus mutants of Rhodobacter sphaeroides.

Science.gov (United States)

Adams, Peter G; Mothersole, David J; Ng, Irene W; Olsen, John D; Hunter, C Neil

2011-09-01

In the model photosynthetic bacterium Rhodobacter sphaeroides domains of light-harvesting 2 (LH2) complexes surround and interconnect dimeric reaction centre-light-harvesting 1-PufX (RC-LH1-PufX) 'core' complexes, forming extensive networks for energy transfer and trapping. These complexes are housed in spherical intracytoplasmic membranes (ICMs), which are assembled in a stepwise process where biosynthesis of core complexes tends to dominate the early stages of membrane invagination. The kinetics of LH2 assembly were measured in PufX mutants that assemble monomeric core complexes, as a consequence of either a twelve-residue N-terminal truncation of PufX (PufXΔ12) or the complete removal of PufX (PufX(-)). Lower rates of LH2 assembly and retarded maturation of membrane invagination were observed for the larger and less curved ICM from the PufX(-) mutant, consistent with the proposition that local membrane curvature, initiated by arrays of bent RC-LH1-PufX dimers, creates a favourable environment for stable assembly of LH2 complexes. Transmission electron microscopy and high-resolution atomic force microscopy were used to examine ICM morphology and membrane protein organisation in these mutants. Some partitioning of core and LH2 complexes was observed in PufX(-) membranes, resulting in locally ordered clusters of monomeric RC-LH1 complexes. The distribution of core and LH2 complexes in the three types of membrane examined is consistent with previous models of membrane curvature and domain formation (Frese et al., 2008), which demonstrated that a combination of crowding and asymmetries in sizes and shapes of membrane protein complexes drives membrane organisation. 2011 Elsevier B.V. All rights reserved.

Highly potent metallopeptide analogues of luteinizing hormone-releasing hormone.

Science.gov (United States)

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

1989-08-01

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

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

Science.gov (United States)

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

2017-11-01

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

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

International Nuclear Information System (INIS)

Dahlen, H.G.

1986-01-01

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

The relationship of EDLS, FSH and LH with PIH

International Nuclear Information System (INIS)

Zhang Xuefeng

2003-01-01

To evaluate the role of serum EDLS, FSH and LH in the pathogenesis of PIH, levels of serum EDLS, FSH and LH were measured by radioimmunoassay in 200 patients with PIH. Results: In PIH group, mean level of serum EDLS was significantly higher than that in the normal control group (P<0.01); mean levels of serum FSH and LH were significantly lower than that in the normal control group (P<0.001). EDLS, FSH and LH may play important action in the pathogenesis of PIH

Differences in Signal Activation by LH and hCG are Mediated by the LH/CG Receptor’s Extracellular Hinge Region

Science.gov (United States)

Grzesik, Paul; Kreuchwig, Annika; Rutz, Claudia; Furkert, Jens; Wiesner, Burkhard; Schuelein, Ralf; Kleinau, Gunnar; Gromoll, Joerg; Krause, Gerd

2015-01-01

The human lutropin (hLH)/choriogonadotropin (hCG) receptor (LHCGR) can be activated by binding two slightly different gonadotropic glycoprotein hormones, choriogonadotropin (CG) – secreted by the placenta, and lutropin (LH) – produced by the pituitary. They induce different signaling profiles at the LHCGR. This cannot be explained by binding to the receptor’s leucine-rich-repeat domain (LRRD), as this binding is similar for the two hormones. We therefore speculate that there are previously unknown differences in the hormone/receptor interaction at the extracellular hinge region, which might help to understand functional differences between the two hormones. We have therefore performed a detailed study of the binding and action of LH and CG at the LHCGR hinge region. We focused on a primate-specific additional exon in the hinge region, which is located between LRRD and the serpentine domain. The segment of the hinge region encoded by exon10 was previously reported to be only relevant to hLH signaling, as the exon10-deletion receptor exhibits decreased hLH signaling, but unchanged hCG signaling. We designed an advanced homology model of the hormone/LHCGR complex, followed by experimental characterization of relevant fragments in the hinge region. In addition, we examined predictions of a helical exon10-encoded conformation by block-wise polyalanine (helix supporting) mutations. These helix preserving modifications showed no effect on hormone-induced signaling. However, introduction of a structure-disturbing double-proline mutant LHCGR-Q303P/E305P within the exon10-helix has, in contrast to exon10-deletion, no impact on hLH, but only on hCG signaling. This opposite effect on signaling by hLH and hCG can be explained by distinct sites of hormone interaction in the hinge region. In conclusion, our analysis provides details of the differences between hLH- and hCG-induced signaling that are mainly determined in the L2-beta loop of the hormones and in the

Effect of early release of tourniquet in total knee arthroplasty

International Nuclear Information System (INIS)

Abbas, K.; Raza, H.; Umer, M.; Hafiz, K.

2013-01-01

To evaluate whether tourniquet release intraoperatively is better than postoperative release in reducing overall blood loss, duration of surgery, duration of tourniquet, length of hospital stay, wound related complications and transfusion requirement. Study Design: Comparative study. Place and Duration of Study: Department of Surgery, The Aga Khan University Hospital, Karachi, from January 2004 to June 2007. Methodology: One hundred and thirty patient files were reviewed retrospectively. Patients were divided into two groups. Group-A consisted of 65 patients with early deflation of tourniquet and group-B comprised of 65 patients with the release of tourniquet after applying compressive dressing. Total blood loss (determined by Gross method) and other study variables were noted as per objective and computed. Results: There were 22 males and 108 females with comparable BMI. All had undergone posterior stabilized cemented total knee replacement. Calculated blood loss was 1.208 L and 1.108 L in group-A and B respectively (p = 0.27). Significant increase in duration of surgery was noted in group-A patients. Four patients in group-B showed complication related to wound with 3 being minor and 1 requiring additional operation room visit. Mean length of hospital stay was 9 days. Transfusion frequency was higher in group-B despite comparable postoperative haemoglobin values. Conclusion: Intraoperative tourniquet release does not reduce overall blood loss with no effect in conserving blood after total knee replacement, however, this group had relatively shorter hospital stay. (author)

Tracing of backward energy transfer from LH1 to LH2 in photosynthetic membranes grown under high and low irradiation.

Directory of Open Access Journals (Sweden)

Lanzani G.

2013-03-01

Full Text Available By introducing derivative transient absorption spectroscopy, we obtain rate constants for backward and forward energy transfer between LH1 and LH2 complexes in purple bacterial membranes. We find that backward energy transfer is strongly reduced in membranes grown under low irradiation conditions, compared to high light grown ones. We conclude that backward energy transfer is managed actively by the bacteria to avoid LH1 exciton deactivation under high irradiation conditions. The analytical method is generally applicable to excitonically coupled systems.

[The lh-rh-test in men with fertility disorders (author's transl)].

Science.gov (United States)

Krause, W; Höbel, W

1976-11-01

89 mal patients with fertility disorders underwent a test with 50 mug synthetic LH-RH. The basal levels of FSH and LH are elevated in patients with azoospermia, with testicular atrophy, varicocele and Klinefelters syndrome. They increase with age. After stimulation with LH-RH the highest relative peaks (maximal value divided by control value) of LH are seen younger patients, in those with varicocele, and oligozoospermia. The FSH-values do not differ significantly between these groups. Low relative peaks of LH are seen in older patients. In Klinefelter's syndrome the relative peaks of FSH and LH are significantly lowered.

The effect of luteinizing hormone releasing hormone (LH-RH) and estrogen on RNA synthesis in anterior pituitary and different brain regions of rats

International Nuclear Information System (INIS)

Biro, J.

1978-01-01

Estradiol-17beta caused a marked reduction of RNA content in the cortex, hippocampus, brain stem, hypothalamus and RNA synthesis in the pituitary. LH-RH had facilitatory effect on the cortical and inhibitory influence on the hypothalamic RNA synthesis in vitro, and suppressed the pituitary RNA synthesis both in vivo and in vitro. The possible regulatory role of the LH-RH in the nucleic acid metabolism is discussed. (author)

Direct visualization of exciton reequilibration in the LH1 and LH2 complexes of Rhodobacter sphaeroides by multipulse spectroscopy.

Science.gov (United States)

Cohen Stuart, Thomas A; Vengris, Mikas; Novoderezhkin, Vladimir I; Cogdell, Richard J; Hunter, C Neil; van Grondelle, Rienk

2011-05-04

The dynamics of the excited states of the light-harvesting complexes LH1 and LH2 of Rhodobacter sphaeroides are governed, mainly, by the excitonic nature of these ring-systems. In a pump-dump-probe experiment, the first pulse promotes LH1 or LH2 to its excited state and the second pulse dumps a portion of the excited state. By selective dumping, we can disentangle the dynamics normally hidden in the excited-state manifold. We find that by using this multiple-excitation technique we can visualize a 400-fs reequilibration reflecting relaxation between the two lowest exciton states that cannot be directly explored by conventional pump-probe. An oscillatory feature is observed within the exciton reequilibration, which is attributed to a coherent motion of a vibrational wavepacket with a period of ∼150 fs. Our disordered exciton model allows a quantitative interpretation of the observed reequilibration processes occurring in these antennas. Copyright © 2011 Biophysical Society. Published by Elsevier Inc. All rights reserved.

The correlation between LH determination in the urine (luteonosticon and HI-gonavis) and serum LH, FSH, oestradiol, progesterone testosterone and prolactin levels at midcycle

International Nuclear Information System (INIS)

Kemeter, P.; Woegerbauer, C.; Gring, H.; Salzer, H.; Friedrich, F.; Breitenecker, G.

1979-01-01

Radioimmunoassays (RIA) were carried out of serum gonadotrophins, prolactin, oestradiol, progesterone and testosterone at the time of presumed ovulation in 15 normal cycles and in 4 clomiphen-stimulated cycles of 14 women. In addition, daily measurements of LH in urine were performed using two semiquantitative methods: Luteonosticon and HI-Gonavis. Finally, the viscosity of the cervical mucus was assessed daily in order to find out the optimum time for conception. LH in serum, as well as in urine, increased significantly at midcycle and so did FSH, progesterone, testosterone, prolactin and viscosity. Lutenosticon, used in the modification of Keller and Gerber 1970 showed the first significant increase 2 days before the serum LH peak. HI-Gonavis, on the other hand, showed a significant increase only on the day of LH peak in serum. The best correlation of the 3 LH methods was found between LH in serum (RIA) and HI-Gonavis in urine. For the evaluation of the optimum time for conception in normal and clomiphen-stimulated cycles, determination of the uriany LH increase at midcycle by HI-Gonavis appears to be the most economic, both in time and expense, hormone method tested. Since only one significant increase in LH becomes apparent at midcycle by this method, the interpretation of the results is easy and additional gynaecological investigations are, thus, not absolutely necessary. (author)

The follicle-stimulating hormone (FSH) and luteinizing hormone (LH) response to a gonadotropin-releasing hormone analogue test in healthy prepubertal girls aged 10 months to 6 years

DEFF Research Database (Denmark)

Vestergaard, Esben T; Schjørring, Mia Elbek; Kamperis, Konstantinos

2017-01-01

and bone age were determined in all participants. Forty-eight healthy normal-weight girls aged 3.5 ± 0.2 years (range: 0.8-5.9 years) were included. Serum concentrations of LH and FSH were measured before and 30 min after the gonadorelin injection. RESULTS: The 30-min LH responses (mean ± 2 s.d.) were 5.......2 ± 4.0 and 2.9 ± 2.5 IU/L and the FSH responses were 23.3 ± 16.2 and 14.5 ± 10.3 IU/L in girls aged 0.8-3.0 years and 3.0-5.9 years respectively. This corresponds to upper cut-off limits for LH of 9.2 IU/L (3 years) and 5.3 IU/L (3-6 years). The stimulated LH/FSH ratio was 0.23 ± 0.19 (range 0.......06-0.43) and did not correlate with age. CONCLUSIONS: We found that LH increases up to 9.2 IU/L during GnRH test in healthy normal-weight girls below 3 years of age and that the stimulated LH/FSH ratio did not exceed 0.43. Our findings have important implications for appropriate diagnosis of central precocious...

Differences in signal activation by LH and hCG are mediated by the LH/CG receptor`s extracellular hinge region

Directory of Open Access Journals (Sweden)

Paul eGrzesik

2015-09-01

Full Text Available The human lutropin/choriogonadotropin receptor (LHCGR can be activated by binding two slightly different gonadotropic glycoprotein hormones, choriogonadotropin (CG - secreted by the placenta, and lutropin (LH - produced by the pituitary. They induce different signaling profiles at the LHCGR. This cannot be explained by binding to the receptor's leucine-rich repeat domain (LRRD, as this binding is similar for the two hormones. We therefore speculate that there are previously unknown differences in the hormone/receptor interaction at the extracellular hinge region, which might help to understand functional differences between the two hormones. We have therefore performed a detailed study of the binding and action of LH and CG at the LHCGR hinge region. We focused on a primate-specific additional exon in the hinge region, which is located between LRRD and the serpentine domain. The segment of the hinge region encoded by exon10 was previously reported to be only relevant to hLH signaling, as the exon10-deletion receptor exhibits decreased hLH signaling, but unchanged hCG signaling. We designed an advanced homology model of the hormone/LHCGR complex, followed by experimental characterization of relevant fragments in the hinge region. In addition, we examined predictions of a helical exon10-encoded conformation by block-wise polyalanine (helix supporting mutations. These helix preserving modifications showed no effect on hormone induced signaling. However, introduction of a structure-disturbing double-proline mutant LHCGR-Q303P/E305P within the exon10-helix has, in contrast to exon10 deletion, no impact on hLH, but only on hCG signaling. This opposite effect on signaling by hLH and hCG can be explained by distinct sites of hormone interaction in the hinge region s. In conclusion, our analysis provides details of the differences between hLH- and hCG-induced signaling that are mainly determined in the L2-beta loop of the hormones and in the hinge region

Circulating LH/hCG receptor (LHCGR may identify pre-treatment IVF patients at risk of OHSS and poor implantation

Directory of Open Access Journals (Sweden)

Chambers Anne E

2011-12-01

Full Text Available Abstract Background Successful pregnancy via in vitro fertilization (IVF depends on the recovery of an adequate number of healthy oocytes and on blastocyst implantation following uterine transfer. Two hormones, LH and hCG, utilize a common LH/hCG receptor (LHCGR, variations in which have profound implications in human reproduction. Soluble LHCGR (sLHCGR is released from experimental cell lines and placental explants and it can be detected in the follicular fluid and serum. Methods To evaluate the impact of circulating soluble LHCGR (sLHCGR in fertility treatment, we measured sLHCGR and LH-sLHCGR complex in serum from women seeking IVF using specifically developed quantitative enzyme-linked immunosorbent assays (ELISA. Following an IVF cycle of treatment, patients were grouped according to oocyte yield into low (lower than or equal to 7 oocytes, intermediate (8-14 oocytes and high (greater than or equal to 15 oocytes responders and pregnancy outcome noted. Results Pre-treatment sLHCGR identified many women at risk of ovarian hyperstimulation. Low levels of sLHCGR were associated with pregnancy in both high and low responders but sLHCGR did not significantly affect the treatment outcome of intermediate responders. Low responders who failed to become pregnant had high levels of circulating sLHCGR bound to LH (LH-sLHCGR. Conclusions Pre-treatment measurement of sLHCGR could be used to tailor individual fertility treatment programs and improve outcomes by avoiding ovarian hyperstimulation and poor embryo implantation.

Understanding L-H transition in tokamak fusion plasmas

Science.gov (United States)

Xu, Guosheng; Wu, Xingquan

2017-03-01

This paper reviews the current state of understanding of the L-H transition phenomenon in tokamak plasmas with a focus on two central issues: (a) the mechanism for turbulence quick suppression at the L-H transition; (b) the mechanism for subsequent generation of sheared flow. We briefly review recent advances in the understanding of the fast suppression of edge turbulence across the L-H transition. We uncover a comprehensive physical picture of the L-H transition by piecing together a number of recent experimental observations and insights obtained from 1D and 2D simulation models. Different roles played by diamagnetic mean flow, neoclassical-driven mean flow, turbulence-driven mean flow, and turbulence-driven zonal flows are discussed and clarified. It is found that the L-H transition occurs spontaneously mediated by a shift in the radial wavenumber spectrum of edge turbulence, which provides a critical evidence for the theory of turbulence quench by the flow shear. Remaining questions and some key directions for future investigations are proposed. This work was supported by National Magnetic Confinement Fusion Science Program of China under Contracts No. 2015GB101000, No. 2013GB106000, and No. 2013GB107000 and National Natural Science Foundation of China under Contracts No. 11575235 and No. 11422546.

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

International Nuclear Information System (INIS)

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

1975-01-01

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

Genetic analysis and fine mapping of LH1 and LH2, a set of complementary genes controlling late heading in rice (Oryza sativa L.).

Science.gov (United States)

Liu, Shuang; Wang, Feng; Gao, Li Jun; Li, Jin Hua; Li, Rong Bai; Gao, Han Liang; Deng, Guo Fu; Yang, Jin Shui; Luo, Xiao Jin

2012-12-01

Heading date in rice (Oryza sativa L.) is a critical agronomic trait with a complex inheritance. To investigate the genetic basis and mechanism of gene interaction in heading date, we conducted genetic analysis on segregation populations derived from crosses among the indica cultivars Bo B, Yuefeng B and Baoxuan 2. A set of dominant complementary genes controlling late heading, designated LH1 and LH2, were detected by molecular marker mapping. Genetic analysis revealed that Baoxuan 2 contains both dominant genes, while Bo B and Yuefeng B each possess either LH1 or LH2. Using larger populations with segregant ratios of 3 : 1, we fine-mapped LH1 to a 63-kb region near the centromere of chromosome 7 flanked by markers RM5436 and RM8034, and LH2 to a 177-kb region on the short arm of chromosome 8 between flanking markers Indel22468-3 and RM25. Some candidate genes were identified through sequencing of Bo B and Yuefeng B in these target regions. Our work provides a solid foundation for further study on gene interaction in heading date and has application in marker-assisted breeding of photosensitive hybrid rice in China.

Structural Stability of Light-harvesting Protein LH2 Adsorbed on Mesoporous Silica Supports.

Science.gov (United States)

Shibuya, Yuuta; Itoh, Tetsuji; Matsuura, Shun-ichi; Yamaguchi, Akira

2015-01-01

In the present study, we examined the reversible thermal deformation of the membrane protein light-harvesting complex LH2 adsorbed on mesoporous silica (MPS) supports. The LH2 complex from Thermochromatium tepidum cells was conjugated to MPS supports with a series of pore diameter (2.4 to 10.6 nm), and absorption spectra of the resulting LH2/MPS conjugates were observed over a temperature range of 273 - 313 K in order to examine the structure of the LH2 adsorbed on the MPS support. The experimental results confirmed that a slight ellipsoidal deformation of LH2 was induced by adsorption on the MPS supports. On the other hand, the structural stability of LH2 was not perturbed by the adsorption. Since the pore diameter of MPS support did not influence the structural stability of LH2, it could be considered that the spatial confinement of LH2 in size-matches pore did not improve the structural stability of LH2.

Immuno-histochemical localization of LH-RH during different phases of estrus cycle of rat, with reference to the preoptic and arcuate neurons, and the ependymal cells.

Science.gov (United States)

Naik, D V

1976-10-06

Immunohistochemical localization of luteinizing hormone-releasing hormone (LH-RH), during different phases of the estrus cycle, in the preoptic, suprachiasmatic and arcuate nuclei, and in the OVLT of rats, with special emphasis on the ependymal cells, was studied by light, fluorescent and electron microscopy, by using rabbit anti serum to synthetic LH-RH. The LH-RH neurons in the above mentioned areas, were very active during late diestrus and early proestrus phases. Specialized ependymal cells bordering the 3rd ventricle also showed varied LH-RH positive reaction during different phases of the estrus cycle. Immunofluorescent studies showed cyclic variations in the LH-RH material in the CSF of the preoptic and infundibular recesses, as well as in the 3rd ventricle near OVLT, in that, it was maximum during late diestrus and early proestrus phases. Immediately after this, the LH-RH late proestrus was reached. We have also observed that during the proestrus phase, as the LH-RH material started declining in the CSF, it had started building up in the specialized ependyma. Estrus, metaestrus and early diestrus phases showed very weak immunofluorescent LH-RH material in the lumen of the infundibular recess and in the specialized ependyma. Our immuno-electron microscopic observations showed pleomorphic LH-RH granules in the specialized ependyma during late kiestrus and proestrus phases. All these observations lead us to believe that LH-RH is not synthesized in the ependymal cells,but is phagocytosed from the CSF of the 3rd ventricle by the specialized ependyma, which transports it to the ME portal system. In males, the fluorescent LH-RH material did not show any noticeable changes. With the present and previous work,it is concluded that the neurons in differentnuclei synthesize LH-RH and transport it to the ME portal system,primarily through the nerve fibers and secondarily by the ventricular route. It is also suggested that the ependymal transport of LH-RH to the ME

Average concentrations of FSH and LH in seminal plasma as determined by radioimmunoassay

International Nuclear Information System (INIS)

Milbradt, R.; Linzbach, P.; Feller, H.

1979-01-01

In 322 males, 25 to 50 years of age, levels of LH and FSH respectively were determined in seminal plasma by radioimmunoassay. Average values of 0,78 ng/ml and 3,95 ng/ml were found as for FSH and LH respectively. Sperm count and motility were not related to FSH levels, but were to LH levels. A high count of spermatozoa corresponded to high concentration of LH, and normal motility was associated with higher levels of LH as compared to levels associated with asthenozoospermia. With respect to count of spermatozoa of a single or the average patient, it is suggested that the ratio of FSH/LH would be more meaningful than LH level alone. (orig.) [de

Isolation and purification of porcine LH for radioimmunoassay and radioreceptor assay

International Nuclear Information System (INIS)

Ziecik, A.; Goralska, M.; Krzymowski, T.; Pogorzelski, K.

1979-01-01

The procedure of isolation and purification of LH from porcine pituitary glands is described. From 1 kg of pituitary glands 150 mg of LH GPZ-1 preparation of high purity were obtained. Immunization of rabbits with the prepared hormone gave homogeneous antibodies against porcine LH with high affinity and low cross-reactions with FSH. Radioreceptor assay with the use of the prepared porcine LH demonstrated the high capacity of cell membrane receptors of the boar tests for binding this hormone. (author)

Follicle-stimulating hormone (FSH) and luteinizing hormone (LH), ch. 10

International Nuclear Information System (INIS)

Franchimont, P.

1976-01-01

A radioimmunoassay for FSH and LH is described. Both FSH and LH were labelled with 131 I by the Greenwood method. The FSH iodination mixture is purified by passing over a column of DEAE cellulose. The LH iodination mixture can be purified by sephadex gel filtration or by cellulose adsorption chromatography. After incubation, the bound and free-labelled hormones are separated by the double antibody technique

Development of a radioimmunoassay for circulating levels of gonadotropin releasing hormone

International Nuclear Information System (INIS)

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

1976-01-01

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

Decreased expression of lysyl hydroxylase 2 (LH2) in skin fibroblasts from three Ehlers-Danlos patients does not result from mutations in either the coding or proximal promoter region of the LH2 gene.

Science.gov (United States)

Walker, L C; Teebi, A S; Marini, J C; De Paepe, A; Malfait, F; Atsawasuwan, P; Yamauchi, M; Yeowell, H N

2004-12-01

The Ehlers-Danlos syndromes (EDS) are a heterogeneous group of inherited connective tissue disorders characterized by tissue fragility, hyperelasticity of the skin and joint hypermobility. This phenotype, accompanied by kyphoscoliosis and/or ocular fragility, is present in patients with the autosomal recessive type VI form of EDS. These patients have significantly decreased levels of lysyl hydroxylase (LH) activity, due to mutations in the LH1 gene. LH hydroxylates specific lysine residues in the collagen molecule that are precursors for the formation of cross-links which provide collagen with its tensile strength. No disorder has been directly linked to decreased expression of LH2 and LH3, two other isoforms of LH. This study describes 3 patients with mixed phenotypes of EDS, who have significantly decreased mRNAs for LH2, but normal levels of LH1 and LH3 mRNAs, in their skin fibroblasts. In contrast to the effect of LH1 deficiency in EDS VI patients, the decreased expression of LH2 does not affect LH activity, bifunctional collagen cross-links (measured after reduction as dihydroxylysinonorleucine (DHLNL) and hydroxylysinonorleucine (HLNL)), or helical lysine hydroxylation in these cell lines. Sequence analysis of full length LH2 cDNAs and 1kb of the promoter region of LH2 does not show mutations that could explain the decreased expression of LH2. These results suggest that the deficiency of LH2 in these fibroblasts may be caused by changes in other factors required for the expression of LH2.

Study on the relationship between serum E2, FSH, LH levels and morphologic changes of uterus and ovary in girls with idiopathic central precocious puberty

International Nuclear Information System (INIS)

Li Jingsong; Du Xueliang; Fu Hongliang; Wu Zhen; Gu Rong; Feng Guoqiang; Wu Jingchuan

2003-01-01

Objective: To explore the characteristics of the girls with idiopathic central precocious puberty (ICPP) through study on the relationship between serum E 2 , FSH, LH levels and morphologic changes of uterus and ovary. Methods: Serum E 2 , FSH and LH levels were measured with ECLIA and morphologic changes of uterus and ovary were studied with B-US in 67 girls with idiopathic central precocious puberty. Results: 1) Among the three types of ovaries (type 1, homogeneous type; type 2, small follicular type; type 3, large follicular type), differences of the serum LH and E 2 values were significant (p 2 levels (p 2 levels were correlated to the maximal follicular diameter but not to the total volume of ovary. It proved that there was close relationship between LH levels and follicular development. It also proved that serum E 2 levels was mainly decided by the development status of the follicles irrespective the total ovary volume. 2) Volume of uterus was correlated to both LH and E 2 levels. Development of uterus was significantly estrogen-dependent. 3) Judgement based upon observations on measurement of serum E 2 , LH, FSH levels and morphologic changes of uterus and ovary would be crucial for establishing the diagnosis of idiopathic central precocious puberty

Effect of LH and prolactin on steroid secretion by perifused luteal tissue from pregnant gilts with induced hypoprolactinemia or after passive immunoneutralization of LH

International Nuclear Information System (INIS)

Szafranska, B.; Przala, J.; Grazul-Bilska, A.

1992-01-01

The study was performed using luteal tissue obtained from 24 pregnant gilts. Group 1 was treated with bromocriptine (BR) from 37th to 42nd day of day of pregnancy. Group 2 was treated with homologous anti-pLH serum from 37th to 42nd day of pregnancy. Group 3 was given BR from 67th to 72nd day of gestation. Group 4 received anti-pLH serum from 67th to 72nd day of pregnancy. The effect of exogenous LH or prolactin (100 ng/ml) on secretion of progesterone (P 4 ) and estradiol (E 2 ) by luteal tissue was studied using perfusion technique. Prolactin caused a significant (P 4 secretion by luteal tissue from gilts in groups 1 and 4. Both LH and prolactin decreased (P 4 and E 2 secretion by luteal tissue from gilts from groups 4 and 2, respectively. The results demonstrate that both LH and prolactin have a regulatory role in steroid secretion by luteal tissue of gilts in the mid- and late period of pregnancy. (author). 28 refs, 2 figs

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

Science.gov (United States)

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

1988-03-01

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

Overexpression of the LH receptor increases distant metastases in an endometrial cancer mouse model

Directory of Open Access Journals (Sweden)

Serena ePillozzi

2013-11-01

Full Text Available Objective. The aim of the present study was to define the role of luteinizing hormone receptor (LH-R expression in endometrial cancer (EC, using preclinical mouse models, to further transfer these data to the clinical setting. Methods. The role of LH-R over-expression was studied using EC cells (Hec1A, e.g. cells with low endogenous LH-R expression transfected with the LH-R (Hec1A-LH-R. In vitro cell proliferation was measured through the WST1 assay, whereas cell invasion was measured trough the matrigel assay. The effects of LH/hCG-R overexpresion in vivo were analyzed in an appropriately developed preclinical mouse model of EC, which mimicked postmenopausal conditions. The model consisted in an orthotopic xenograft of Hec1A cells into immunodeficient mice treated daily with recombinant LH, to assure high levels of LH. Results. In vitro data indicated that LH-R overexpression increased Hec1A invasiveness. In vivo results showed that tumors arising from Hec1A-LH-R cells injection displayed a higher local invasion and a higher number of distant metastases, mainly in the lung, compared to tumors obtained from the injection of Hec1A cells. LH withdrawl strongly inhibited local and distant metastatic spread of tumors, especially those arising from Hec1A-LH-R cells. Conclusions. The overexpression of the LH-R increases the ability of EC cells to undergo local invasion and metastatic spread. This occurs in the presence of high LH serum concentrations.

The cytoskeleton proteins and LH-regulated steroidogenesis in porcine luteal cells

International Nuclear Information System (INIS)

Gregoraszczuk, Ewa L.; Slomczynska, Maria

1996-01-01

The involvement of microtubules (MT) and microflilaments (MF) in LH-regulation of luteal cell stereoidogenesis was assessed at the middle stage of corpus luteum development. The influence microtubule- and microfilament-altering agents on basal and LH-stimulated progesterone (P4) production and secretion into the incubation medium was determined by RIA. LH-stimulated P4 production was 2.5 times higher than in the control cultures. Cytochalasis B (Cyt B) was without effect on basal P4 synthesis but increased the basal fraction of P4 secreted into the incubation medium, while colchicine (Col) increased both basal P4 synthesis and the fraction of P4 secreted into the incubation medium. LH-stimulated progesterone synthesis was reduced by Col, but the fraction secreted into the incubation medium increased. Cyt B had no effect on LH-stimulated synthesis but it decreased the fraction of P4 secreted into the incubation medium. Our findings demonstrate significant differences in the effect of Cyt B and Col on steroidogenesis in corpus luteum. We conclude that microtubules play an important role in the process of LH-stimulated P4 synthesis, while microfilaments act in the process of basal and LH-stimulated P4 secretion. (author). 23 refs, 4 figs

Ground Operations Demonstration Unit for Liquid Hydrogen (GODU LH2)

Science.gov (United States)

Notardonato, William U.

2015-01-01

When the technology associated with zero loss storage and transfer is implemented, NASA can reduce the LH2 losses and procurement costs by up to 30 compared to historical Shuttle numbers. This return on investment is based on the mission manifest and commodity use. LH2 densification can provide improved launch vehicle ascent performance by minimizing the size of the LH2 tanks or storing more mass of propellant in the given tank volume.

Weak evidence of bright light effects on human LH and FSH

Directory of Open Access Journals (Sweden)

Kripke Daniel F

2010-05-01

Full Text Available Abstract Background Most mammals are seasonal breeders whose gonads grow to anticipate reproduction in the spring and summer. As day length increases, secretion increases for two gonadotropins, luteinizing hormone (LH and follicle stimulating hormone (FSH. This response is largely controlled by light. Light effects on gonadotropins are mediated through effects on the suprachiasmatic nucleus and responses of the circadian system. There is some evidence that seasonal breeding in humans is regulated by similar mechanisms, and that light stimulates LH secretion, but primate responses seem complex. Methods To gain further information on effects of bright light on LH and FSH secretion in humans, we analyzed urine samples collected in three experiments conducted for other goals. First, volunteers ages 18-30 years and 60-75 commenced an ultra-short 90-min sleep-wake cycle, during which they were exposed to 3000 lux light for 3 hours at balanced times of day, repeated for 3 days. Urine samples were assayed to explore any LH phase response curve. Second, depressed participants 60-79 years of age were treated with bright light or dim placebo light for 28 days, with measurements of urinary LH and FSH before and after treatment. Third, women of ages 20-45 years with premenstrual dysphoric disorder (PMDD were treated to one 3-hour exposure of morning light, measuring LH and FSH in urine before and after the treatments. Results Two of the three studies showed significant increases in LH after light treatment, and FSH also tended to increase, but there were no significant contrasts with parallel placebo treatments and no significant time-of-day treatment effects. Conclusions These results gave some support for the hypothesis that bright light may augment LH secretion. Longer-duration studies may be needed to clarify the effects of light on human LH and FSH.

Weak evidence of bright light effects on human LH and FSH.

Science.gov (United States)

Kripke, Daniel F; Elliott, Jeffrey A; Youngstedt, Shawn D; Parry, Barbara L; Hauger, Richard L; Rex, Katharine M

2010-05-11

Most mammals are seasonal breeders whose gonads grow to anticipate reproduction in the spring and summer. As day length increases, secretion increases for two gonadotropins, luteinizing hormone (LH) and follicle stimulating hormone (FSH). This response is largely controlled by light. Light effects on gonadotropins are mediated through effects on the suprachiasmatic nucleus and responses of the circadian system. There is some evidence that seasonal breeding in humans is regulated by similar mechanisms, and that light stimulates LH secretion, but primate responses seem complex. To gain further information on effects of bright light on LH and FSH secretion in humans, we analyzed urine samples collected in three experiments conducted for other goals. First, volunteers ages 18-30 years and 60-75 commenced an ultra-short 90-min sleep-wake cycle, during which they were exposed to 3000 lux light for 3 hours at balanced times of day, repeated for 3 days. Urine samples were assayed to explore any LH phase response curve. Second, depressed participants 60-79 years of age were treated with bright light or dim placebo light for 28 days, with measurements of urinary LH and FSH before and after treatment. Third, women of ages 20-45 years with premenstrual dysphoric disorder (PMDD) were treated to one 3-hour exposure of morning light, measuring LH and FSH in urine before and after the treatments. Two of the three studies showed significant increases in LH after light treatment, and FSH also tended to increase, but there were no significant contrasts with parallel placebo treatments and no significant time-of-day treatment effects. These results gave some support for the hypothesis that bright light may augment LH secretion. Longer-duration studies may be needed to clarify the effects of light on human LH and FSH.

Diagnostic evaluation of serum FSH and LH in primary amenorrhea by radioimmunoassay

International Nuclear Information System (INIS)

Hong, I.S.; Kim, G.E.; Yoo, H.S.; Lee, J.T.; Park, C.Y.

1980-01-01

The usefulness of single, random measurements of serum FSH and LH in the diagnosis of primary amenorrhea by radioimmunoassay was investigated. The 16 patients were divided into 3 groups by the level of serum FSH and LH. The first group with increased level of serum FSH and LH is five patients, all of these are related to the acquired or congenital abnormality of the ovary. Further studies indicated include buccal smear, chromosome analysis, gynecography and laparoscopy. The second group with normal serum FSH and LH is nine patients, four patients of these are related to the developmental anomaly of the Mullerian duct and five patients are undetermined origin. Further studies indicated include laparoscopy and gynecography. The third group with decreased serum FSH and normal or decreased serum LH is two patients, one of these is related to the pituitary function, isolated FSH deficiency, the other is undetermined origin. Further studies indicated include the pituitary function test, LH-RH stimulation test, skull radiography. Determination of serum FSH and LH levels does not permit a specific etiologic diagnosis of promary amenorrhea. However the serum levels of FSH and LH can be used to differentiate the principal area of the investigation and can be of assistance in choosing more specific testing procedures. (Author)

Recovery of pituitary-gonadal function in male and female rats after prolonged administration of a potent antagonist of luteinizing hormone-releasing hormone (SB-75).

Science.gov (United States)

Bokser, L; Srkalovic, G; Szepeshazi, K; Schally, A V

1991-08-01

The reversibility of the antifertility effects induced by long-term administration of the LH-RH antagonistic analog [Ac-D-Nal(2)1, D-Phe(4Cl)2, D-Pal(3)3, D-Cit6, D-Ala10]-LH-RH (SB-75) was investigated in male and female rats. Male rats were implanted with osmotic minipumps releasing 50 micrograms of SB-75/day for 60 days. The control rats were implanted with minipumps containing only vehicle. The treatment with the antagonist caused a significant decrease in the weights of the testes, seminal vesicles and ventral prostates (p less than 0.01) and reduced serum LH and testosterone levels (p less than 0.01). The histology of the testes from the treated rats showed that spermatogenesis was totally depressed. No mature elongated or round spermatids were found in the seminiferous tubules, spermatocytes being the most advanced germ cell form in 100% of the testicular tubules. These changes indicate that a total spermatogenetic arrest occurred in the treated animals. Ninety days after cessation of treatment with the LH-RH antagonist, there was a complete recovery of the weights of the testes, seminal vesicles and ventral prostates and LH and testosterone returned to control levels. Histological studies revealed a complete recovery of spermatogenesis, with 99.2% of seminiferous tubules containing mature elongated spermatids. Immediately after the discontinuation of treatment with SB-75, a significant down-regulation of the pituitary LH-RH receptors was found, but 90 days later, this phenomenon was completely reversed. Female rats were injected every 3 weeks for 6 weeks with SB-75 microcapsules, at a dose calculated to release 27 micrograms/day of the antagonist. The treatment with SB-75 disrupted the normal estrous cycle. Body weights were not affected, but ovarian and uterine weights were significantly decreased (p less than 0.01 and p less than 0.05, respectively) in the animals treated with the antagonist. Treated rats had significantly lower LH (p less than 0.05) and

Astronomy. ASASSN-15lh: A highly super-luminous supernova.

Science.gov (United States)

Dong, Subo; Shappee, B J; Prieto, J L; Jha, S W; Stanek, K Z; Holoien, T W-S; Kochanek, C S; Thompson, T A; Morrell, N; Thompson, I B; Basu, U; Beacom, J F; Bersier, D; Brimacombe, J; Brown, J S; Bufano, F; Chen, Ping; Conseil, E; Danilet, A B; Falco, E; Grupe, D; Kiyota, S; Masi, G; Nicholls, B; Olivares E, F; Pignata, G; Pojmanski, G; Simonian, G V; Szczygiel, D M; Woźniak, P R

2016-01-15

We report the discovery of ASASSN-15lh (SN 2015L), which we interpret as the most luminous supernova yet found. At redshift z = 0.2326, ASASSN-15lh reached an absolute magnitude of Mu ,AB = -23.5 ± 0.1 and bolometric luminosity Lbol = (2.2 ± 0.2) × 10(45) ergs s(-1), which is more than twice as luminous as any previously known supernova. It has several major features characteristic of the hydrogen-poor super-luminous supernovae (SLSNe-I), whose energy sources and progenitors are currently poorly understood. In contrast to most previously known SLSNe-I that reside in star-forming dwarf galaxies, ASASSN-15lh appears to be hosted by a luminous galaxy (MK ≈ -25.5) with little star formation. In the 4 months since first detection, ASASSN-15lh radiated (1.1 ± 0.2) × 10(52) ergs, challenging the magnetar model for its engine. Copyright © 2016, American Association for the Advancement of Science.

Conditions and limits of serum LH radioimmunoassay in normal, hypophysectomised or castred rats

International Nuclear Information System (INIS)

Andre, M.; Boucher, D.; Thieblot, L.

1976-01-01

Serum LH was measured by radioimmunoassay (NIAMD Kits) free and linked hormones were separated by double antibodies method. Influence of concentration on antibody-hormone complex is studied. Hypophysectomised rats serum does not modify results. The standard (rat LH-RPl) has the same action as serum LH. Rat serum LH contents are measured in normal or castred rats [fr

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

International Nuclear Information System (INIS)

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

1985-01-01

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

Production and Characterization of Anti-LH Polyclonal Antibodies for Establishment of Sepharose Solid Phase Radioimmunoassay

International Nuclear Information System (INIS)

Ebeid, N.H.; Mehany, N.L.

2016-01-01

The present study was designed to achieve the production and characterization of polyclonal antibody of luteinizing hormone (Anti-LH) as a basic component of LH radioimmunoassay (RIA). The main objective was to improve the immunogenicity of LH by conjugation of LH with bovine serum albumin (LH: BSA) as a protein carrier using Ethyl dimethylaminopropyl Carbodiimide (ECDI). Production of Anti-LH was described where LH : BSA immunogen was immunized into three male mature white New-Zealand rabbits through primary immunization and four boosters. The criteria for selecting LH antiserum for liquid phase RIA system were mainly titer, displacement and immuno response profile and followed by partial purification of IgG-LH. The radioiodinated 125 I-LH tracer was carried out using Chloramine-T as an oxidizing agent and the tracer was purified through PD-10 column. The preparation of LH standards was carried out. Coupling of purified IgG-LH to activated Sepharose particles CL-4B was carried out after activation of Sepharose particles with 1,1-carbonyldiimidazole. Extensive studies were carried out to obtain the optimum conditions of using solid phase Sepharose particles to reach the optimum separation efficiency. The results of validation tests revealed that the local solid phase RIA system is precise and accurate to detect LH concentration in human serum to be used as a diagnostic tool in investigating the infertility in the hypothalamic pituitary gonadal disorders

Comparison of radioimmunology and serology methods for LH determination

International Nuclear Information System (INIS)

Szymanski, W.; Jakowicki, J.

1976-01-01

A comparison is presented of LH determinations by immunoassay and radioimmunoassay using the 125 I-labelled HCG double antibody system. The results obtained by both methods are well comparable and in normal and elevated LH levels the serological determinations may be used for estimating concentration levels found by RIA. (L.O.)

Developmental programming: Prenatal BPA treatment disrupts timing of LH surge and ovarian follicular wave dynamics in adult sheep

International Nuclear Information System (INIS)

Veiga-Lopez, A.; Beckett, E.M.; Abi Salloum, B.; Ye, W.; Padmanabhan, V.

2014-01-01

Developmental exposure to BPA adversely affects reproductive function. In sheep, prenatal BPA treatment induces reproductive neuroendocrine defects, manifested as LH excess and dampened LH surge and perturbs early ovarian gene expression. In this study we hypothesized that prenatal BPA treatment will also disrupt ovarian follicular dynamics. Pregnant sheep were treated from days 30 to 90 of gestation with 3 different BPA doses (0.05, 0.5, or 5 mg/kg BW/day). All female offspring were estrus synchronized and transrectal ultrasonography was performed daily for 22 days to monitor ovarian follicular and corpora lutea dynamics. Blood samples were collected to assess preovulatory hormonal changes and luteal progesterone dynamics. Statistical analysis revealed that the time interval between the estradiol rise and the preovulatory LH surge was shortened in the BPA-treated females. None of the three BPA doses had an effect on corpora lutea, progestogenic cycles, and mean number or duration of ovulatory and non-ovulatory follicles. However, differences in follicular count trajectories were evident in all three follicular size classes (2–3 mm, 4–5 mm, and ≥ 6 mm) of prenatal BPA-treated animals compared to controls. Number of follicular waves tended also to be more variable in the prenatal BPA-treated groups ranging from 2 to 5 follicular waves per cycle, while this was restricted to 3 to 4 waves in control females. These changes in ovarian follicular dynamics coupled with defects in time interval between estradiol rise and preovulatory LH release are likely to lead to subfertility in prenatal BPA-treated females. - Highlights: • Prenatal BPA shortens interval between estradiol rise and preovulatory LH surge. • Prenatal BPA affects follicular count trajectory and follicular wave occurrence. • Prenatal BPA does not affect ovulatory rate and progesterone dynamics

Developmental programming: Prenatal BPA treatment disrupts timing of LH surge and ovarian follicular wave dynamics in adult sheep

Energy Technology Data Exchange (ETDEWEB)

Veiga-Lopez, A.; Beckett, E.M.; Abi Salloum, B. [Department of Pediatrics, University of Michigan, Ann Arbor, MI (United States); Ye, W. [Department of Biostatistics, University of Michigan, Ann Arbor, MI (United States); Padmanabhan, V., E-mail: vasantha@umich.edu [Department of Pediatrics, University of Michigan, Ann Arbor, MI (United States); The Reproductive Sciences Program, University of Michigan, Ann Arbor, MI (United States)

2014-09-01

Developmental exposure to BPA adversely affects reproductive function. In sheep, prenatal BPA treatment induces reproductive neuroendocrine defects, manifested as LH excess and dampened LH surge and perturbs early ovarian gene expression. In this study we hypothesized that prenatal BPA treatment will also disrupt ovarian follicular dynamics. Pregnant sheep were treated from days 30 to 90 of gestation with 3 different BPA doses (0.05, 0.5, or 5 mg/kg BW/day). All female offspring were estrus synchronized and transrectal ultrasonography was performed daily for 22 days to monitor ovarian follicular and corpora lutea dynamics. Blood samples were collected to assess preovulatory hormonal changes and luteal progesterone dynamics. Statistical analysis revealed that the time interval between the estradiol rise and the preovulatory LH surge was shortened in the BPA-treated females. None of the three BPA doses had an effect on corpora lutea, progestogenic cycles, and mean number or duration of ovulatory and non-ovulatory follicles. However, differences in follicular count trajectories were evident in all three follicular size classes (2–3 mm, 4–5 mm, and ≥ 6 mm) of prenatal BPA-treated animals compared to controls. Number of follicular waves tended also to be more variable in the prenatal BPA-treated groups ranging from 2 to 5 follicular waves per cycle, while this was restricted to 3 to 4 waves in control females. These changes in ovarian follicular dynamics coupled with defects in time interval between estradiol rise and preovulatory LH release are likely to lead to subfertility in prenatal BPA-treated females. - Highlights: • Prenatal BPA shortens interval between estradiol rise and preovulatory LH surge. • Prenatal BPA affects follicular count trajectory and follicular wave occurrence. • Prenatal BPA does not affect ovulatory rate and progesterone dynamics.

Fluorescence spectroscopy of conformational changes of single LH2 complexes

NARCIS (Netherlands)

Rutkauskas, D.; Novoderezhkin, V.; Cogdell, R.J.; van Grondelle, R.

2005-01-01

We have investigated the energy landscape of the bacterial photosynthetic peripheral light-harvesting complex LH2 of purple bacterium Rhodopseudomonas acidophila by monitoring sequences of fluorescence spectra of single LH2 assemblies, at room temperature, with different excitation intensities as

Gonadotropin determination in 24-h-urine by sensitive LH and FSH radioimmunoassays

International Nuclear Information System (INIS)

Raid, A.; Fenske, M.; Koenig, A.

1979-01-01

Urinary lutropin (LH) and follitropin (FSH) were precipitated with acetone and measured by specific radioimmunoassays. Recovery experiments with special regard to urinary pH values were done by adding 125 I-labelled LH and FSH to unprocessed urine. At pH 4.5 68.6% of LH and 66.1% of FSH were recovered. Increasing pH values up to 6.0 resulted in a significant recovery loss of 125 I-LH, but not of 125 I-FSH. Immunoreactive FSH concentrations decreased significantly 6 and 48 hours after starting storage at room temperature. In healthy males and females there were found mean LH and FSH concentrations in 24-h-urine which were similar to those reported by others: LH: males: 22.6 IU; cycling females: 17.8 IU; postmenopausal females: 49.1 IU; FSH: males 6.0 IU; cycling females: 15.0 IU; postmenopausal females: 48.5 IU. Because of their high sensitivity and practicability. These radioimmunoassays could be clinically useful approaches in assessment of pituitary and gonadal disorders in human subjects. (author)

Developmental programming: Prenatal BPA treatment disrupts timing of LH surge and ovarian follicular wave dynamics in adult sheep

Science.gov (United States)

Veiga-Lopez, A; Beckett, EM; Abi Salloum, B; Ye, W; Padmanabhan, V

2014-01-01

Developmental exposure to BPA adversely affects reproductive function. In sheep, prenatal BPA treatment induces reproductive neuroendocrine defects, manifested as LH excess and dampened LH surge and perturbs early ovarian gene expression. In this study we hypothesized that prenatal BPA treatment will also disrupt ovarian follicular dynamics. Pregnant sheep were treated from days 30 to 90 of gestation with 3 different BPA doses (0.05, 0.5, or 5 mg/kg BW/day). All female offspring were estrus synchronized and transrectal ultrasonography was performed daily for 22 days to monitor ovarian follicular and corpora lutea dynamics. Blood samples were collected to assess hormonal preovulatory changes and luteal progesterone dynamics. Statistical analysis revealed that the time interval between the estradiol rise and the preovulatory LH surge was shortened in the BPA-treated females. None of the three BPA doses had an effect on corpora lutea, progestogenic cycles, and mean or duration of ovulatory and non-ovulatory follicles. However, differences in follicular count trajectories were evident in all three follicular size classes (2–3 mm, 4–5 mm, and ≥ 6 mm) of prenatal BPA-treated animals compared to controls. Number of follicular waves tended also to be more variable in the prenatal BPA-treated groups ranging from 2 to 5 follicular waves per cycle, while this was restricted to 3 to 4 waves in control females. These changes in ovarian follicular dynamics coupled with defects in time interval between estradiol rise and preovulatory LH release are likely to lead to subfertility in prenatal BPA-treated females. PMID:24923655

Peripheral Inhibitor of AChE, Neostigmine, Prevents the Inflammatory Dependent Suppression of GnRH/LH Secretion during the Follicular Phase of the Estrous Cycle

Directory of Open Access Journals (Sweden)

Andrzej P. Herman

2017-01-01

Full Text Available The study was designed to test the hypothesis that the inhibition of acetylcholinesterase (AChE activity at the periphery by Neostigmine (0.5 mg/animal will be sufficient to prevent inflammatory dependent suppression of the gonadotropin-releasing hormone (GnRH/luteinising hormone (LH secretion in ewes in the follicular phase of the estrous cycle, and this effect will be comparable with the systemic AChE inhibitor, Donepezil (2.5 mg/animal. An immune/inflammatory challenge was induced by peripheral administration of lipopolysaccharide (LPS; 400 ng/kg. Peripheral treatment with Donepezil and Neostigmine prevented the LPS-induced decrease (P<0.05 in LHβ gene expression in the anterior pituitary gland (AP and in LH release. Moreover, Donepezil completely abolished (P<0.05 the suppressory effect of inflammation on GnRH synthesis in the preoptic area, when pretreatment with Neostigmine reduced (P<0.05 the decrease in GnRH content in this hypothalamic structure. Moreover, administration of both AChE inhibitors diminished (P<0.05 the inhibitory effect of LPS treatment on the expression of GnRH receptor in the AP. Our study shows that inflammatory dependent changes in the GnRH/LH secretion may be eliminated or reduced by AChE inhibitors suppressing inflammatory reaction only at the periphery such as Neostigmine, without the need for interfering in the central nervous system.

Do Substance P and Neurokinin A Play Important Roles in the Control of LH Secretion in Ewes?

Science.gov (United States)

Fergani, Chrysanthi; Mazzella, Leanne; Coolen, Lique M.; McCosh, Richard B.; Hardy, Steven L.; Newcomb, Nora; Grachev, Pasha; Lehman, Michael N.

2016-01-01

There is now general agreement that neurokinin B (NKB) acts via neurokinin-3-receptor (NK3R) to stimulate secretion of GnRH and LH in several species, including rats, mice, sheep, and humans. However, the roles of two other tachykinins, substance P (SP) and neurokinin A, which act primarily via NK1R and NK2R, respectively, are less clear. In rodents, these signaling pathways can stimulate LH release and substitute for NKB signaling; in humans, SP is colocalized with kisspeptin and NKB in the mediobasal hypothalamus. In this study, we examined the possible role of these tachykinins in control of the reproductive axis in sheep. Immunohistochemistry was used to describe the expression of SP and NK1R in the ovine diencephalon and determine whether these proteins are colocalized in kisspeptin or GnRH neurons. SP-containing cell bodies were largely confined to the arcuate nucleus, but NK1R-immunoreactivity was more widespread. However, there was very low coexpression of SP or NK1R in kisspeptin cells and none in GnRH neurons. We next determined the minimal effective dose of these three tachykinins that would stimulate LH secretion when administered into the third ventricle of ovary-intact anestrous sheep. A much lower dose of NKB (0.2 nmol) than of neurokinin A (2 nmol) or SP (10 nmol) consistently stimulated LH secretion. Moreover, the relative potency of these three neuropeptides parallels the relative selectivity of NK3R. Based on these anatomical and pharmacological data, we conclude that NKB-NK3R signaling is the primary pathway for the control of GnRH secretion by tachykinins in ewes. PMID:27704950

Analogues of luteinizing hormone-releasing hormone containing cytotoxic groups.

Science.gov (United States)

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

1992-02-01

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

The total release of xenon-133 from the Fukushima Dai-ichi nuclear power plant accident

International Nuclear Information System (INIS)

Stohl, Andreas; Seibert, Petra; Wotawa, Gerhard

2012-01-01

The accident at the Fukushima Dai-ichi nuclear power plant (FD-NPP) on 11 March 2011 released large amounts of radioactivity into the atmosphere. We determine the total emission of the noble gas xenon-133 ( 133 Xe) using global atmospheric concentration measurements. For estimating the emissions, we used three different methods: (i) using a purely observation-based multi-box model, (ii) comparisons of dispersion model results driven with GFS meteorological data with the observation data, and (iii) such comparisons with the dispersion model driven by ECMWF data. From these three methods, we have obtained total 133 Xe releases from FD-NPP of (i) 16.7 ± 1.9 EBq, (ii) 14.2 ± 0.8 EBq, and (iii) 19.0 ± 3.4 EBq, respectively. These values are substantially larger than the entire 133 Xe inventory of FD-NPP of about 12.2 EBq derived from calculations of nuclear fuel burn-up. Complete release of the entire 133 Xe inventory of FD-NPP and additional release of 133 Xe due to the decay of iodine-133 ( 133 I), which can add another 2 EBq to the 133 Xe FD-NPP inventory, is required to explain the atmospheric observations. Two of our three methods indicate even higher emissions, but this may not be a robust finding given the differences between our estimates. - Highlights: ► We determine the total release of xenon-133 from the Fukushima nuclear accident. ► We used global measurements and a box model, as well as dispersion model estimates. ► Total 133 Xe release is about 14.2-19 EBq, more than Fukushima 133 Xe inventory. ► Additional release of iodine-133 and decay into 133 Xe needed to explain results.

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...

High-resolution AFM topographs of Rubrivivax gelatinosus light-harvesting complex LH2

Science.gov (United States)

Scheuring, Simon; Reiss-Husson, Francoise; Engel, Andreas; Rigaud, Jean-Louis; Ranck, Jean-Luc

2001-01-01

Light-harvesting complexes 2 (LH2) are the accessory antenna proteins in the bacterial photosynthetic apparatus and are built up of αβ-heterodimers containing three bacteriochlorophylls and one carotenoid each. We have used atomic force microscopy (AFM) to investigate reconstituted LH2 from Rubrivivax gelatinosus, which has a C-terminal hydrophobic extension of 21 amino acids on the α-subunit. High-resolution topographs revealed a nonameric organization of the regularly packed cylindrical complexes incorporated into the membrane in both orientations. Native LH2 showed one surface which protruded by ∼6 Å and one that protruded by ∼14 Å from the membrane. Topographs of samples reconstituted with thermolysin-digested LH2 revealed a height reduction of the strongly protruding surface to ∼9 Å, and a change of its surface appearance. These results suggested that the α-subunit of R.gelatinosus comprises a single transmembrane helix and an extrinsic C-terminus, and allowed the periplasmic surface to be assigned. Occasionally, large rings (∼120 Å diameter) surrounded by LH2 rings were observed. Their diameter and appearance suggest the large rings to be LH1 complexes. PMID:11406579

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

NARCIS (Netherlands)

Turkstra, Jouwert Anne

2005-01-01

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

Anchored LH2 complexes in 2D polarization imaging.

Science.gov (United States)

Tubasum, Sumera; Sakai, Shunsuke; Dewa, Takehisa; Sundström, Villy; Scheblykin, Ivan G; Nango, Mamoru; Pullerits, Tõnu

2013-09-26

Protein is a soft material with inherently large structural disorder. Consequently, the bulk spectroscopies of photosynthetic pigment protein complexes provide averaged information where many details are lost. Here we report spectroscopy of single light-harvesting complexes where fluorescence excitation and detection polarizations are both independently rotated. Two samples of peripheral antenna (LH2) complexes from Rhodopseudomonas acidophila were studied. In one, the complexes were embedded in polyvinyl alcohol (PVA) film; in the other, they were anchored on the glass surface and covered by the PVA film. LH2 contains two rings of pigment molecules-B800 and B850. The B800 excitation polarization properties of the two samples were found to be very similar, indicating that orientation statistics of LH2s are the same in these two very different preparations. At the same time, we found a significant difference in B850 emission polarization statistics. We conclude that the B850 band of the anchored sample is substantially more disordered. We argue that both B800 excitation and B850 emission polarization properties can be explained by the tilt of the anchored LH2s due to the spin-casting of the PVA film on top of the complexes and related shear forces. Due to the tilt, the orientation statistics of two samples become similar. Anchoring is expected to orient the LH2s so that B850 is closer to the substrate. Consequently, the tilt-related strain leads to larger deformation and disorder in B850 than in B800.

Energy transfer dynamics in an RC-LH1-PufX tubular photosynthetic membrane

International Nuclear Information System (INIS)

Hsin, J; Sener, M; Schulten, K; Struempfer, J; Qian, P; Hunter, C N

2010-01-01

Light absorption and the subsequent transfer of excitation energy are the first two steps in the photosynthetic process, carried out by protein-bound pigments, mainly bacteriochlorophylls (BChls), in photosynthetic bacteria. BChls are anchored in light-harvesting (LH) complexes, such as light-harvesting complex I (LH1), which directly associates with the reaction center (RC), forming the RC-LH1 core complex. In Rhodobacter sphaeroides, RC-LH1 core complexes contain an additional protein, PufX, and assemble into dimeric RC-LH1-PufX core complexes. In the absence of LH complex II (LH2), the former complexes can aggregate into a helically ordered tubular photosynthetic membrane. We have examined the excitation transfer dynamics in a single RC-LH1-PufX core complex dimer using the hierarchical equations of motion for dissipative quantum dynamics that accurately, yet in a computationally costly manner, treat the coupling between BChls and their protein environment. A widely employed description, the generalized Foerster (GF) theory, was also used to calculate the transfer rates of the same excitonic system in order to verify the accuracy of this computationally cheap method. Additionally, in light of the structural uncertainties in the Rba. sphaeroides RC-LH1-PufX core complex, geometrical alterations were introduced into the BChl organization. It is shown that the energy transfer dynamics are not affected by the considered changes in the BChl organization and that the GF theory provides accurate transfer rates. An all-atom model for a tubular photosynthetic membrane is then constructed on the basis of electron microscopy data, and the overall energy transfer properties of this membrane are computed.

Energy transfer dynamics in an RC-LH1-PufX tubular photosynthetic membrane

Energy Technology Data Exchange (ETDEWEB)

Hsin, J; Sener, M; Schulten, K [Department of Physics and Beckman Institute, University of Illinois at Urbana-Champaign, Urbana (United States); Struempfer, J [Center for Biophysics and Computational Biology and Beckman Institute, University of Illinois at Urbana-Champaign, Urbana (United States); Qian, P; Hunter, C N, E-mail: kschulte@ks.uiuc.ed [Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN (United Kingdom)

2010-08-15

Light absorption and the subsequent transfer of excitation energy are the first two steps in the photosynthetic process, carried out by protein-bound pigments, mainly bacteriochlorophylls (BChls), in photosynthetic bacteria. BChls are anchored in light-harvesting (LH) complexes, such as light-harvesting complex I (LH1), which directly associates with the reaction center (RC), forming the RC-LH1 core complex. In Rhodobacter sphaeroides, RC-LH1 core complexes contain an additional protein, PufX, and assemble into dimeric RC-LH1-PufX core complexes. In the absence of LH complex II (LH2), the former complexes can aggregate into a helically ordered tubular photosynthetic membrane. We have examined the excitation transfer dynamics in a single RC-LH1-PufX core complex dimer using the hierarchical equations of motion for dissipative quantum dynamics that accurately, yet in a computationally costly manner, treat the coupling between BChls and their protein environment. A widely employed description, the generalized Foerster (GF) theory, was also used to calculate the transfer rates of the same excitonic system in order to verify the accuracy of this computationally cheap method. Additionally, in light of the structural uncertainties in the Rba. sphaeroides RC-LH1-PufX core complex, geometrical alterations were introduced into the BChl organization. It is shown that the energy transfer dynamics are not affected by the considered changes in the BChl organization and that the GF theory provides accurate transfer rates. An all-atom model for a tubular photosynthetic membrane is then constructed on the basis of electron microscopy data, and the overall energy transfer properties of this membrane are computed.

Effect of metal nanoparticles on energy spectra and optical properties of peripheral light-harvesting LH2 complexes from photosynthetic bacteria

International Nuclear Information System (INIS)

Goliney, I.Yu.; Sugakov, V.I.; Valkunas, L.; Vertsimakha, G.V.

2012-01-01

Highlights: ► Excitons of light-harvesting complexes (LH2) hybridize with plasmon modes. ► Light absorption of LH2 is enhanced by a metal nanoparticle. ► Using nanoshells allows reaching resonance between molecular and plasmons. ► Metal nanoparticles introduce additional channel of excitation decay. ► Light-harvesting may gain from the proper positioning of nanoshells. -- Abstract: The paper explores the theoretical possibility of affecting optical spectra and the quantum yield of the energy transfer in the peripheral light-harvesting complexes (LH2) from photosynthetic bacteria by placing a metal nanoparticle or a nanoshell nearby. An increased probability of the excitonic transition in the LH2 arises due to the borrowing of the oscillator strength from surface plasmons of the metal particle or the nanoshell. While both absorption and quenching of the excitations increase in the vicinity to a metal nanoparticle, having opposite effects, the total yield of the excitation transfer to reaction centers is shown to grow in the certain range of parameters.

Effect of metal nanoparticles on energy spectra and optical properties of peripheral light-harvesting LH2 complexes from photosynthetic bacteria

Energy Technology Data Exchange (ETDEWEB)

Goliney, I.Yu., E-mail: igoliney@kinr.kiev.ua [Institute for Nuclear Research, National Academy of Science of Ukraine, 47 Nauki pr., 03680 Kyiv (Ukraine); Sugakov, V.I. [Institute for Nuclear Research, National Academy of Science of Ukraine, 47 Nauki pr., 03680 Kyiv (Ukraine); Valkunas, L. [Center for Physical Sciences and Technology, Savanoriu Ave. 231, 02300 Vilnius (Lithuania); Department of Theoretical Physics, Vilnius University, Sauletekio 9, Build. 3, 10222 Vilnius (Lithuania); Vertsimakha, G.V. [Institute for Nuclear Research, National Academy of Science of Ukraine, 47 Nauki pr., 03680 Kyiv (Ukraine)

2012-08-24

Highlights: Black-Right-Pointing-Pointer Excitons of light-harvesting complexes (LH2) hybridize with plasmon modes. Black-Right-Pointing-Pointer Light absorption of LH2 is enhanced by a metal nanoparticle. Black-Right-Pointing-Pointer Using nanoshells allows reaching resonance between molecular and plasmons. Black-Right-Pointing-Pointer Metal nanoparticles introduce additional channel of excitation decay. Black-Right-Pointing-Pointer Light-harvesting may gain from the proper positioning of nanoshells. -- Abstract: The paper explores the theoretical possibility of affecting optical spectra and the quantum yield of the energy transfer in the peripheral light-harvesting complexes (LH2) from photosynthetic bacteria by placing a metal nanoparticle or a nanoshell nearby. An increased probability of the excitonic transition in the LH2 arises due to the borrowing of the oscillator strength from surface plasmons of the metal particle or the nanoshell. While both absorption and quenching of the excitations increase in the vicinity to a metal nanoparticle, having opposite effects, the total yield of the excitation transfer to reaction centers is shown to grow in the certain range of parameters.

Comparison of L-H transition measurements with physics models

International Nuclear Information System (INIS)

Carlstrom, T.N.; Burrell, K.H.; Carreras, B.A.

1999-01-01

Sawteeth and neutrals are found to have a significant influence on the H-mode power threshold scaling. The ion ∇B drift direction has only a small effect on the edge plasma conditions measured near the plasma midplane but a large effect on the divertor plasma. Since the power threshold changes dramatically with the direction of the ion ∇B drift, this implies that phenomena in the divertor region are critical for the L-H transition. Local conditions at the plasma edge are consistent with several theories of the L-H transition that use edge gradients in their formulation of a critical threshold parameter. However, scatter in the database is too large to distinguish between conditions that lead to an L-H transition and those that remain in L-mode. (author)

Comparison of L-H transition measurements with physics models

International Nuclear Information System (INIS)

Carlstrom, T.N.; Burrell, K.H.; Groebner, R.J.

2001-01-01

Sawteeth and neutrals are found to have a significant influence on the H-mode power threshold scaling. The ion ∇B drift direction has only a small effect on the edge plasma conditions measured near the plasma midplane but a large effect on the divertor plasma. Since the power threshold changes dramatically with the direction of the ion ∇B drift, this implies that phenomena in the divertor region are critical for the L-H transition. Local conditions at the plasma edge are consistent with several theories of the L-H transition that use edge gradients in their formulation of a critical threshold parameter. However, scatter in the database is too large to distinguish between conditions that lead to an L-H transition and those that remain in L-mode. (author)

Use of length heterogeneity polymerase chain reaction (LH-PCR as non-invasive approach for dietary analysis of Svalbard reindeer, Rangifer tarandus platyrhynchus.

Directory of Open Access Journals (Sweden)

Sungbae Joo

Full Text Available To efficiently investigate the forage preference of Svalbard reindeer (Rangifer tarandus platyrhynchus, we applied length-heterogeneity polymerase chain reaction (LH-PCR based on length differences of internal transcribed spacer (ITS regions of ribosomal RNA (rRNA to fecal samples from R. tarandus platyrhynchus. A length-heterogeneity (LH database was constructed using both collected potential food sources of Svalbard reindeer and fecal samples, followed by PCR, cloning and sequencing. In total, eighteen fecal samples were collected between 2011 and 2012 from 2 geographic regions and 15 samples were successfully amplified by PCR. The LH-PCR analysis detected abundant peaks, 18.6 peaks on an average per sample, ranging from 100 to 500 bp in size and showing distinct patterns associated with both regions and years of sample collection. Principal component analysis (PCA resulted in clustering of 15 fecal samples into 3 groups by the year of collection and region with a statistically significant difference at 99.9% level. The first 2 principal components (PCs explained 71.1% of the total variation among the samples. Through comparison with LH database and identification by cloning and sequencing, lichens (Stereocaulon sp. and Ochrolechia sp. and plant species (Salix polaris and Saxifraga oppositifolia were detected as the food sources that contributed most to the Svalbard reindeer diet. Our results suggest that the use of LH-PCR analysis would be a non-invasive and efficient monitoring tool for characterizing the foraging strategy of Svalbard reindeer. Additionally, combining sequence information would increase its resolving power in identification of foraged diet components.

Effects of recombinant LH treatment on folliculogenesis and responsiveness to FSH stimulation

DEFF Research Database (Denmark)

Durnerin, Cedrin I; Erb, K; Fleming, R

2008-01-01

at the start of r-hLH treatment, on FSH stimulation Days 0 and 8 and at the time of HCG administration. RESULTS: The LH treatment was associated with increased small antral follicles prior to FSH stimulation (P = 0.007), and an increased yield of normally fertilized (2 PN) embryos (P = 0...... in a clinical setting by employing a sequential approach to stimulation by recombinant human (r-h) LH followed by r-hFSH in women who were profoundly down-regulated by depo GnRH agonist. METHODS: We employed a multi-centre, prospective, randomized approach. Women (n = 146) were treated in a long course high......-dose GnRH agonist (Decapeptyl, 4.2 mg s.c.) protocol and were randomized to receive r-hLH (Luveris, 300 IU/day) for a fixed 7 days, or no r-hLH treatment. This was followed by a standard r-hFSH stimulation regime (Gonal-F, 150 IU/day). Ultrasound and hormone assessments of responses were measured...

The organization of LH2 complexes in membranes from Rhodobacter sphaeroides.

Science.gov (United States)

Olsen, John D; Tucker, Jaimey D; Timney, John A; Qian, Pu; Vassilev, Cvetelin; Hunter, C Neil

2008-11-07

The mapping of the photosynthetic membrane of Rhodobacter sphaeroides by atomic force microscopy (AFM) revealed a unique organization of arrays of dimeric reaction center-light harvesting I-PufX (RC-LH1-PufX) core complexes surrounded and interconnected by light-harvesting LH2 complexes (Bahatyrova, S., Frese, R. N., Siebert, C. A., Olsen, J. D., van der Werf, K. O., van Grondelle, R., Niederman, R. A., Bullough, P. A., Otto, C., and Hunter, C. N. (2004) Nature 430, 1058-1062). However, membrane regions consisting solely of LH2 complexes were under-represented in these images because these small, highly curved areas of membrane rendered them difficult to image even using gentle tapping mode AFM and impossible with contact mode AFM. We report AFM imaging of membranes prepared from a mutant of R. sphaeroides, DPF2G, that synthesizes only the LH2 complexes, which assembles spherical intracytoplasmic membrane vesicles of approximately 53 nm diameter in vivo. By opening these vesicles and adsorbing them onto mica to form small, LH2-only membranes for the first time. The transition from highly curved vesicle to the planar sheet is accompanied by a change in the packing of the LH2 complexes such that approximately half of the complexes are raised off the mica surface by approximately 1 nm relative to the rest. This vertical displacement produces a very regular corrugated appearance of the planar membrane sheets. Analysis of the topographs was used to measure the distances and angles between the complexes. These data are used to model the organization of LH2 complexes in the original, curved membrane. The implications of this architecture for the light harvesting function and diffusion of quinones in native membranes of R. sphaeroides are discussed.

A common polymorphic allele of the LH beta-subunit gene is associated with higher exogenous FSH consumption during controlled ovarian stimulation for assisted reproductive technology

DEFF Research Database (Denmark)

Alviggi, Carlo; Pettersson, Kim; Longobardi, Salvatore

2013-01-01

BACKGROUND: V-betaLH is a common genetic variant of LH caused by two polymorphic base changes in the beta subunit gene, altering the amino acid sequence (Trp8Arg and Ile15Thr). In a previous-preliminary trial performed in women undergoing IVF, it was demonstrated that carriers of v-betaLH show sub......-optimal ovarian response to a standard long GnRH-agonist down -regulation protocol when stimulated with pure recombinant FSH (r-hFSH). The aim of this study was to confirm the hypothesis that women with v-betaLH display hypo-sensitivity to exogenous FSH in a larger IVF population and to explore the frequency...... of this variant in a Danish female population. METHODS: In the present study, the effect of v-betaLH was retrospectively investigated in a larger series of women undergoing controlled ovarian stimulation (COS) and, for the first time, in a Danish IVF population. A total of 220 normogonadotrophic women following...

Convection-type LH2 absorber R and D for muon ionization cooling

International Nuclear Information System (INIS)

Ishimoto, S.; Bandura, L.; Black, E.L.; Boghosian, M.; Cassel, K.W.; Cummings, M.A.; Darve, C.; Dyshkant, A.; Errede, D.; Geer, S.; Haney, M.; Hedin, D.; Johnson, R.; Johnstone, C.J.; Kaplan, D.M.; Kubik, D.; Kuno, Y.; Majewski, S.; Popovic, M.; Reep, M.; Summers, D.; Suzuki, S.; Yoshimura, K.

2003-01-01

A feasibility study on liquid hydrogen (LH 2 ) absorbers for muon ionization cooling is reported. In muon ionization cooling, an LH 2 absorber is required to have a high cooling power greater than 100 W to cool heat deposited by muons passing through. That heat in LH 2 can be removed at either external or internal heat exchangers, which are cooled by cold helium gas. As one of the internal heat exchanger types, a convection-type absorber is proposed. In the convection-type absorber, heat is taken away by the convection of LH 2 in the absorber. The heat exchanger efficiency for the convection-type absorber is calculated. A possible design is presented

A comparison between r-LH and urinary supplements containing LH activity in patients undergoing the microdose GnRH agonist flare protocol for in-vitro fertilization: a pilot study.

Science.gov (United States)

Shavit, Tal; Agdi, Mohammed; Son, Weon Y; Hasson, Josseph; Dahan, Michael H

2016-08-01

The aim of this study was to compare pregnancy rates and stimulation parameters in patients with diminished ovarian reserve, who were treated with recombinant human luteinizing hormone (r-LH) or menopausal gonadotropins (hMG), as part of a microdose flare protocol. A retrospective cohort study was performed. Comparisons between the group that was stimulated with r-LH plus follicle stimulating hormone (FSH) to those treated with hMG and FSH, were performed. Measurements included: medication doses, number of oocyte collected, number of embryos obtained, pregnancy and clinical pregnancy rates. Patients in the r-LH group (N.=40) had significant higher clinical pregnancy rates (33% vs. 14%; P=0.04) and used lower dose of LH (1938 IU vs. 2807 IU; P=0.02) compared to patients that were stimulated with hMG (N.=39). r-LH may offer advantages for the treatment of diminished ovarian reserve when performing a microdose flare protocol when compared to hMG. Both larger and prospective studies should be carried out to confirm these findings.

Bifurcation analysis and dimension reduction of a predator-prey model for the L-H transition

DEFF Research Database (Denmark)

Dam, Magnus; Brøns, Morten; Juul Rasmussen, Jens

2013-01-01

The L-H transition denotes a shift to an improved confinement state of a toroidal plasma in a fusion reactor. A model of the L-H transition is required to simulate the time dependence of tokamak discharges that include the L-H transition. A 3-ODE predator-prey type model of the L-H transition...

LH-power coupling in advanced tokamak plasmas in JET

International Nuclear Information System (INIS)

Joffrin, E.; Erents, K.; Gormezano, C.

2000-02-01

Lower Hybrid Current Drive (LHCD) is the most efficient tool to generate non-inductive current in tokamak plasmas. In JET, significant modifications of the current profile have been recently achieved in coupling up to 3MW of LH power in optimised shear discharges. However, the improved particle confinement during optimised shear plasmas results in a sharp decrease of the electron density in front the launcher close or below the cut-off density (ne=1.7.10 17 m -3 for f LH =37GHz) and makes difficult the coupling of the LH power. Deuterium gas near the launcher can help to improve the coupling, but has also the effect of increasing the ELM activity leading to the erosion of the internal transport barrier (ITB). Future development of lower hybrid launcher should include the constraints imposed by scenario such as the optimised shear. (author)

Construction of hybrid photosynthetic units using peripheral and core antennae from two different species of photosynthetic bacteria: detection of the energy transfer from bacteriochlorophyll a in LH2 to bacteriochlorophyll b in LH1.

Science.gov (United States)

Fujii, Ritsuko; Shimonaka, Shozo; Uchida, Naoko; Gardiner, Alastair T; Cogdell, Richard J; Sugisaki, Mitsuru; Hashimoto, Hideki

2008-01-01

Typical purple bacterial photosynthetic units consist of supra-molecular arrays of peripheral (LH2) and core (LH1-RC) antenna complexes. Recent atomic force microscopy pictures of photosynthetic units in intact membranes have revealed that the architecture of these units is variable (Scheuring et al. (2005) Biochim Bhiophys Acta 1712:109-127). In this study, we describe methods for the construction of heterologous photosynthetic units in lipid-bilayers from mixtures of purified LH2 (from Rhodopseudomonas acidophila) and LH1-RC (from Rhodopseudomonas viridis) core complexes. The architecture of these reconstituted photosynthetic units can be varied by controlling ratio of added LH2 to core complexes. The arrangement of the complexes was visualized by electron-microscopy in combination with Fourier analysis. The regular trigonal array of the core complexes seen in the native photosynthetic membrane could be regenerated in the reconstituted membranes by temperature cycling. In the presence of added LH2 complexes, this trigonal symmetry was replaced with orthorhombic symmetry. The small lattice lengths for the latter suggest that the constituent unit of the orthorhombic lattice is the LH2. Fluorescence and fluorescence-excitation spectroscopy was applied to the set of the reconstituted membranes prepared with various proportions of LH2 to core complexes. Remarkably, even though the LH2 complexes contain bacteriochlorophyll a, and the core complexes contain bacteriochlorophyll b, it was possible to demonstrate energy transfer from LH2 to the core complexes. These experiments provide a first step along the path toward investigating how changing the architecture of purple bacterial photosynthetic units affects the overall efficiency of light-harvesting.

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

Science.gov (United States)

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

1992-11-01

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

Influence of hormonal control on LH pulsatility and secretion in women with classical congenital adrenal hyperplasia.

Science.gov (United States)

Bachelot, Anne; Chakhtoura, Zeina; Plu-Bureau, Geneviève; Coudert, Mathieu; Coussieu, Christiane; Badachi, Yasmina; Dulon, Jérome; Charbit, Beny; Touraine, Philippe

2012-10-01

Women with classical congenital adrenal hyperplasia (CAH) exhibit reduced fertility due to several factors including anovulation. This has been attributed to a disturbed gonadotropic axis as in polycystic ovary syndrome (PCOS), but there is no precise evaluation. Our aim was to evaluate the gonadotropic axis and LH pulsatility patterns and to determine factor(s) that could account for the potential abnormality of LH pulsatility. Case/control study. Sixteen CAH women (11 with the salt-wasting form and five with the simple virilizing form), aged from 18 to 40 years, and 16 age-matched women, with regular menstrual cycles (28 ± 3 days), were included. LH pulse patterns over 6 h were determined in patients and controls. No differences were observed between patients and controls in terms of mean LH levels, LH pulse amplitude, or LH frequency. In CAH patients, LH pulsatility patterns were heterogeneous, leading us to perform a clustering analysis of LH data, resulting in a two-cluster partition. Patients in cluster 1 had similar LH pulsatility patterns to the controls. Patients in cluster 2 had: lower LH pulse amplitude and frequency and presented menstrual cycle disturbances more frequently; higher 17-OH progesterone, testosterone, progesterone, and androstenedione levels; and lower FSH levels. LH pulsatility may be normal in CAH women well controlled by hormonal treatment. Undertreatment is responsible for hypogonadotropic hypogonadism, with low LH pulse levels and frequency, but not PCOS. Suppression of progesterone and androgen concentrations during the follicular phase of the menstrual cycle should be a major objective in these patients.

Photosynthetic complex LH2 – Absorption and steady state fluorescence spectra

International Nuclear Information System (INIS)

Zapletal, David; Heřman, Pavel

2014-01-01

Nowadays, much effort is devoted to the study of photosynthesis which could be the basis for an ideal energy source in the future. To be able to create such an energy source – an artificial photosynthetic complex, the first step is a detailed understanding of the function of photosynthetic complexes in living organisms. Photosynthesis starts with the absorption of a solar photon by one of the LH (light-harvesting) pigment–protein complexes and transferring the excitation energy to the reaction center where a charge separation is initiated. The geometric structure of some LH complexes is known in great detail, e.g. for the LH2 complexes of purple bacteria. For understanding of photosynthesis first stage efficiency, it is necessary to study especially optical properties of LH complexes. In this paper we present simulated absorption and steady-state fluorescence spectra for ring molecular system within full Hamiltonian model. Such system can model bacteriochlorophyll ring of peripheral light-harvesting complex LH2 from purple bacterium Rhodopseudomonas acidophila (Rhodoblastus acidophilus). Dynamic disorder (coupling with phonon bath) simultaneously with uncorrelated static disorder (transfer integral fluctuations) is used in our present simulations. We compare and discuss our new results with our previously published ones and of course with experimental data. - Highlights: • We model absorption and steady state fluorescence spectra for B850 ring from LH2. • Fluctuations of environment is modelled by static and dynamic disorder. • Full Hamiltonian model is compared with the nearest neighbour approximation one. • Simulated fluorescence spectrum is compared with experimental data

Ovarian hyperstimulation, hyperprolactinaemia and LH gonadotroph adenoma.

Science.gov (United States)

Castelo-Branco, Camil; del Pino, Marta; Valladares, Esther

2009-08-01

This report considers a highly exceptional case of ovarian hyperstimulation syndrome due to a gonadotroph adenoma secreting LH in a 31-year-old patient who presented with amenorrhoea and galactorrhoea syndrome and a complex bilateral ovarian mass. Magnetic resonance imaging revealed a pituitary adenoma, and laboratory tests corroborated the hyperprolactinaemia without other hormonal pituitary abnormalities. Ovarian hyperstimulation syndrome due to a gonadotroph adenoma with normal gonadotrophins is extremely rare. Most of the described cases are caused by FSH adenomas. Due to the originality of the case, it was considered useful for understanding the management of this entity, and it is proposed that LH adenomas should also be considered in the differential diagnosis of patients with spontaneous ovarian hyperstimulation syndrome.

Variations of serum testosterone levels in prostate cancer patients under LH-releasing hormone therapy: an open question.

Science.gov (United States)

Reis, Leonardo Oliveira

2012-06-01

The hypothesis 'the lower the better when achieving castration levels of testosterone' is based on the data from second-line hormonal manipulation and its molecular basis, and on better oncological results reported for lower castration levels in prostate cancer (PCa) patients, including those achieved with maximal androgen blockade. In this regard, the equivalence of surgical and different pharmacological castrations has been controversial. The modified amino acid structure that makes LH-releasing hormone (LHRH) analogs more potent than LHRH, and the method of delivering the analogs impacts on bioavailibility and potentially causes differences in androgen levels and in its final oncological efficacy. In addition to this, there is a myriad of circumstances, such as those related to ethnic variations and co-morbidities, which uniquely impact on the pharmacological approach in a highly heterogeneous population of castration-resistant prostate cancer (CRPC) patients. Ineffective testosterone suppression through hormonal escape is currently poorly recognized and may result in increased PCa mortality. Until now, the optimal serum testosterone level in patients under castration, and the impact of its variations in patients under LHRH therapy, remain open questions and have been merged to a broad spectra of patients who are highly heterogeneous. This heterogeneity relates to a number of mechanisms regarding response to treatment, which influences the biology of the relapsing tumor and the sensitivity to subsequent therapies in the individual patient. The rationale to achieve testosterone levels below 20-50 ng/dl warrant further investigation as these levels have recently rescued CRPC patients. In the last few years and months, important advancements in prostate cancer treatment have been achieved. Nevertheless, these advances are measured in a few months of additional survival and under high costs, not available to most of the world population, compared with the benefits

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

Science.gov (United States)

Lubin, V; Charbonnel, B; Bouchard, P

1998-12-01

Polycystic ovarian disease (PCOD) is characterized by anovulation, eventually high luteinizing hormone (LH) levels, with increased LH pulse frequency, and hyperandrogenism. As the aetiology of the disease is still unknown, gonadotrophin-releasing hormone (GnRH) antagonists, competitive inhibitors of GnRH for its receptor, are interesting tools in order to study and treat the role of increased LH levels and pulse frequency in this disease. Their administration provokes a rapid decrease in bioactive and immunoactive LH followed by a slower decrease in follicle-stimulating hormone (FSH). In patients with PCOD, the suppression of gonadotrophin secretion eradicates the symptoms of the disease as long as the treatment lasts. Several authors have suggested that increased plasma LH levels have deleterious effects on the fertility of women with PCOD. Indeed, fewer spontaneous pregnancies with more miscarriages are observed when plasma LH levels are high. Assisted reproduction techniques such as in vitro fertilization (IVF) have provided other clues to the role of the LH secretory pattern in women with PCOD. The number of oocytes retrieved, the fertilization rate and the cleavage rate are lower in PCOD patients undergoing IVF and this is inversely correlated with FSH:LH ratio. These abnormalities are corrected when endogenous secretion of LH is suppressed. On the other hand, implantation and pregnancy rates after IVF are similar to those observed in control women. New GnRH antagonists are devoid of side effects and suppress LH secretion within a few hours without a flare-up effect. This action lasts for 10-100 hours. When GnRH antagonists are associated with i.v. pulsatile GnRH, this combination both suppresses the effect of endogenous GnRH and because of the competition for GnRH receptors restores a normal frequency of LH secretion. We have studied two women with PCOD, administering first 10 mg s.c. every 72 hours for 7 days of the GnRH antagonist Nal-Glu, then adding on

Protein structural deformation induced lifetime shortening of photosynthetic bacteria light-harvesting complex LH2 excited state.

Science.gov (United States)

Chen, Xing-Hai; Zhang, Lei; Weng, Yu-Xiang; Du, Lu-Chao; Ye, Man-Ping; Yang, Guo-Zhen; Fujii, Ritsuko; Rondonuwu, Ferdy S; Koyama, Yasushi; Wu, Yi-Shi; Zhang, J P

2005-06-01

Photosynthetic bacterial light-harvesting antenna complex LH2 was immobilized on the surface of TiO(2) nanoparticles in the colloidal solution. The LH2/TiO(2) assembly was investigated by the time-resolved spectroscopic methods. The excited-state lifetimes for carotenoid-containing and carotenoidless LH2 have been measured, showing a decrease in the excited-state lifetime of B850 when LH2 was immobilized on TiO(2). The possibility that the decrease of the LH2 excited-state lifetime being caused by an interfacial electron transfer reaction between B850 and the TiO(2) nanoparticle was precluded experimentally. We proposed that the observed change in the photophysical properties of LH2 when assembled onto TiO(2) nanoparticles is arising from the interfacial-interaction-induced structural deformation of the LH2 complex deviating from an ellipse of less eccentric to a more eccentric ellipse, and the observed phenomenon can be accounted by an elliptical exciton model. Experiment by using photoinactive SiO(2) nanoparticle in place of TiO(2) and core complex LH1 instead of LH2 provide further evidence to the proposed mechanism.

Aerodigitalni senzori - LH Systems ADS 40 / Airborne digital sensors: LH Systems ADS 40

Directory of Open Access Journals (Sweden)

Marko Pejić

2004-01-01

Full Text Available U radu su prezentovane osnove prikupljanja prostornih podataka metodom daljinske detekcije i klasičnim fotogrametrijskim metodom. Ukazano je na kompromis između dva metoda koji nudi digitalna aerokamera. Kompanija LH Systems proizvela je digitalnu aerokameru ADS 40 koja nudi sasvim nov koncept prikupljanja prostornih podataka. Sistem kamere obezbeđuje panhromatske i trodimenzionalne informacije koristeći tri CCD linije i opciono još pet linija iz multispektralnog opsega. Kamera skenira teren sa prostornom rezolucijom od 25 cm, površine od 300 kvadratnih kilometara, uz vreme trajanja leta koje je nešto kraće od jednog sata. / This paper presents basics of collecting spatial data with remote sensing and the classical photogrammetric method. A compromise between two methods, offered by a digital aero camera, is also suggested. The LH Systems has produced a new camera concept called Airborne Digital Sensor (ADS 40 which uses a new way of collecting spatial data. The camera system provides panchromatic and stereo information using three CCD lines and up to five more lines for multispectral imagery. The performance of the camera allows a three dimensional and multispectral image with a ground sample distance of 25 cm for an area of 300 square miles within a flight time shorter than one hour.

Failure of total hip implants: metals and metal release in 52 cases

DEFF Research Database (Denmark)

Jakobsen, Stig Storgaard; Lidén, Carola; Søballe, Kjeld

2014-01-01

Background . The pathogenesis of total joint replacement failure is multifactorial. One hypothesis suggests that corrosion and wear of alloys result in metal ion release, which may then cause sensitization and even implant failure, owing to the acquired immune reactivity. Objectives . To assess c...

The total kinetic energy release in the fast neutron-induced fission of {sup 232}Th

Energy Technology Data Exchange (ETDEWEB)

King, Jonathan; Yanez, Ricardo; Loveland, Walter; Barrett, J. Spencer; Oscar, Breland [Oregon State University, Dept. of Chemistry, Corvallis, OR (United States); Fotiades, Nikolaos; Tovesson, Fredrik; Young Lee, Hye [Los Alamos National Laboratory, Physics Division, Los Alamos, NM (United States)

2017-12-15

The post-emission total kinetic energy release (TKE) in the neutron-induced fission of {sup 232}Th was measured (using white spectrum neutrons from LANSCE) for neutron energies from E{sub n} = 3 to 91 MeV. In this energy range the average post-neutron total kinetic energy release decreases from 162.3 ± 0.3 at E{sub n} = 3 MeV to 154.9 ± 0.3 MeV at E{sub n} = 91 MeV. Analysis of the fission mass distributions indicates that the decrease in TKE with increasing neutron energy is a combination of increasing yields of symmetric fission (which has a lower associated TKE) and a decrease in the TKE release in asymmetric fission. (orig.)

Protein Structural Deformation Induced Lifetime Shortening of Photosynthetic Bacteria Light-Harvesting Complex LH2 Excited State

OpenAIRE

Chen, Xing-Hai; Zhang, Lei; Weng, Yu-Xiang; Du, Lu-Chao; Ye, Man-Ping; Yang, Guo-Zhen; Fujii, Ritsuko; Rondonuwu, Ferdy S.; Koyama, Yasushi; Wu, Yi-Shi; Zhang, J. P.

2005-01-01

Photosynthetic bacterial light-harvesting antenna complex LH2 was immobilized on the surface of TiO2 nanoparticles in the colloidal solution. The LH2/TiO2 assembly was investigated by the time-resolved spectroscopic methods. The excited-state lifetimes for carotenoid-containing and carotenoidless LH2 have been measured, showing a decrease in the excited-state lifetime of B850 when LH2 was immobilized on TiO2. The possibility that the decrease of the LH2 excited-state lifetime being caused by ...

Convection-type LH{sub 2} absorber R and D for muon ionization cooling

Energy Technology Data Exchange (ETDEWEB)

Ishimoto, S. E-mail: shigeru.ishimoto@kek.jp; Bandura, L.; Black, E.L.; Boghosian, M.; Cassel, K.W.; Cummings, M.A.; Darve, C.; Dyshkant, A.; Errede, D.; Geer, S.; Haney, M.; Hedin, D.; Johnson, R.; Johnstone, C.J.; Kaplan, D.M.; Kubik, D.; Kuno, Y.; Majewski, S.; Popovic, M.; Reep, M.; Summers, D.; Suzuki, S.; Yoshimura, K

2003-05-01

A feasibility study on liquid hydrogen (LH{sub 2}) absorbers for muon ionization cooling is reported. In muon ionization cooling, an LH{sub 2} absorber is required to have a high cooling power greater than 100 W to cool heat deposited by muons passing through. That heat in LH{sub 2} can be removed at either external or internal heat exchangers, which are cooled by cold helium gas. As one of the internal heat exchanger types, a convection-type absorber is proposed. In the convection-type absorber, heat is taken away by the convection of LH{sub 2} in the absorber. The heat exchanger efficiency for the convection-type absorber is calculated. A possible design is presented.

Body mass index and gonadotropin hormones (LH & FSH) associate with clinical symptoms among women with polycystic ovary syndrome.

Science.gov (United States)

Esmaeilzadeh, Seddigheh; Andarieh, Maryam Ghanbari; Ghadimi, Reza; Delavar, Mouloud Agajani

2014-09-28

To evaluate the relevance of body mass index (BMI), luteinizing hormone (LH), follicle-stimulating hormone (FSH) and LH/FSH ratio with clinical symptoms in polycystic ovary syndrome (PCOS) women. We reviewed the medical records of all women visited in the PCOS Clinic of Babol (Iran) from 2008 to 2012. A retrospective cross-sectional study was conducted on 175 PCOS women; aged 18-38 years diagnosed based on the Rotterdam criteria. Among the PCOs women, the prevalence of oligomenorrhea, acne, and hirsutism were found to be 92.0%, 31.4%, and 78.9%, respectively. Positive finding of polycystic ovaries was observed in 89.1% of PCOS women with by using sonography. A total of 69.2% overweight/obesity patients had polycystic ovary morphology on ultrasound image. Compared with non- overweight/obesity, the adjusted OR of PCOS women for sonographic view of polycystic ovaries was 4.33 (95% CI, 1.42-13.15, p=0.001), Nevertheless, the adjusted odds ratio (OR) showed no significant associations between LH, FSH, and LH/FSH ratio with clinical symptoms in these women. The findings of this study indicated that the overweight/obese women with PCOS are at an increased risk for sonographic view of polycystic ovaries. Therefore, it is suggested that successful weight loss is the most effective method of restoring ovulation, menstruation that should be used as major advice in obese PCOS patients.

Pretest analysis document for Semiscale Test S-LH-1

International Nuclear Information System (INIS)

Shaw, R.A.

1985-03-01

Results from various pretest calculations which were performed for Test S-LH-1 are included in this report. Test S-LH-1 has been designed to produce primary liquid holdup in the steam generator U-tubes similar to Tests S-UT-8. The analyses included in this report indicate liquid will be held in the tubes, the core liquid level will be appropriately depressed, and a core heater rod temperature excursion should occur. Several sensitivity studies are also included which identify parameters which could affect the response

In vitro assay for ACTH-releasing activity using ACTH radioimmunoassay. ACTH releasing activities by various drugs

Energy Technology Data Exchange (ETDEWEB)

Hashimoto, K; Takahara, J; Hosogi, H; Ofuji, N; Yasuhara, T [Okayama Univ. (Japan). School of Medicine

1976-02-01

This report deals with an in vitro assay of ACTH releasing activity utilizing pituitary incubation combined with ACTH radioimmunoassay. Half of a rat pituitary was preincubated in 2ml Krebs Ringer bicarbonate buffer containing 0.2% glucose and 0.25% BSA (KRBG-BSA) for 1.5 hr (45 min x 2). The medium was replaced by 1 ml KRBG-BSA and incubated for 30 min. Then the medium was again replaced by 1 ml KRBG-BSA or KRBG-BSA containing test materials and incubated for another 30 min. The amount of ACTH assayed by radioimmunoassay in the 2nd 30 min incubation was compared with that in the 1st 30 min incubation, and the result was expressed as a percentage. In the ACTH radioimmunoassay, anti-ACTH serum was diluted to 1:1,500-3,000. The /sup 125/I-..cap alpha../sup 1 -24/ACTH-antibody system was not affected by lysine-vasopressin (LVP), arginine-vasopressin (AVP), rat's pituitary LH, GH or prolactin. Human /sup 1 -39/ACTH was used as the ACTH standard. The dilution curve of the incubation medium was parallel to the standard curve. Reproducibility of immunoassayable ACTH within-assay was 174 +- 5.0 pg/tube (CV=2.9%). A log dose-relationship was observed between the amounts of stalk median eminence extracts (SME; NIAMDD) added to the incubation medium and its ACTH releasing activities. The sensitivity of this assay method was at least 0.1 SME or 10 mU of LVP and AVP. Using this method, it was found that LVP, AVP, norepinephrine (100 ng/ml--200 ng/ml) and 5-hydroxytryptophane (1 ..mu..g/ml) had ACTH releasing activities, but LH-RH, TRH, glucagon, dopamine, phentolamine, propranolol, haloperidol, prostaglandin E/sub 1/ and indomethacin did not affect the release of ACTH.

Intracerebroventricular Infusion of Vasoactive Intestinal Peptide (VIP Rescues the Luteinizing Hormone Surge in Middle-Aged Female Rats

Directory of Open Access Journals (Sweden)

Yan eSun

2012-02-01

Full Text Available Reproductive aging is characterized by delayed and attenuated luteinizing hormone (LH surges apparent in middle-aged rats. The suprachiasmatic nucleus (SCN contains the circadian clock that is responsible for the timing of diverse neuroendocrine rhythms. Electrophysiological studies suggest vasoactive intestinal peptide (VIP originating from the SCN excites gonadotropin-releasing hormone (GnRH neurons and affects daily patterns of GnRH-LH release. Age-related LH surge dysfunction correlates with reduced VIP mRNA expression in the SCN and fewer GnRH neurons with VIP contacts expressing c-fos, a marker of neuronal activation, on the day of the LH surge. To determine if age-related LH surge dysfunction reflects reduced VIP availability or altered VIP responsiveness under estradiol positive feedback conditions, we assessed the effect of intracerebroventricular (icv VIP infusion on c-fos expression in GnRH neurons and on LH release in ovariohysterectomized, hormone-primed young and middle-aged rats. Icv infusion of VIP between 1300 and 1600 h significantly advanced the time of peak LH release, increased total and peak LH release, and increased the number of GnRH neurons expressing c-fos on the day of the LH surge in middle-aged rats. Surprisingly, icv infusion of VIP in young females significantly reduced the number of GnRH neurons expressing c-fos and delayed and reduced the LH surge. These observations suggest that a critical balance of VIP signaling is required to activate GnRH neurons for an appropriately timed and robust LH surge in young and middle-aged females. Age-related LH surge changes may, in part, result from decreased availability and reduced VIP-mediated neurotransmission under estradiol positive feedback conditions.

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

Science.gov (United States)

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

1985-08-15

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

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

Science.gov (United States)

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

2000-05-01

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

LH-receptor gene expression in human granulosa and cumulus cells from antral and preovulatory follicles

DEFF Research Database (Denmark)

Jeppesen, Janni Vikkelsø; Kristensen, Stine Gry; Nielsen, Maria Eilsø

2012-01-01

Context:Human granulosa cells (GC) acquire LH receptor (LHR) expression during the follicular phase of the menstrual cycle. Currently, the precise follicular stage is unknown, and specific roles of LH in the follicular development are not fully understood.Objective:Our objective was to measure LH...

Membrane Curvature Induced by Aggregates of LH2s and Monomeric LH1s

OpenAIRE

Chandler, Danielle E.; Gumbart, James; Stack, John D.; Chipot, Christophe; Schulten, Klaus

2009-01-01

The photosynthetic apparatus of purple bacteria is contained within organelles called chromatophores, which form as extensions of the cytoplasmic membrane. The shape of these chromatophores can be spherical (as in Rhodobacter sphaeroides), lamellar (as in Rhodopseudomonas acidophila and Phaeospirillum molischianum), or tubular (as in certain Rb. sphaeroides mutants). Chromatophore shape is thought to be influenced by the integral membrane proteins Light Harvesting Complexes I and II (LH1 and ...

Risk Assessment and Scaling for the SLS LH2 ET

Science.gov (United States)

Hafiychuk, Halyna; Ponizovskaya-Devine, Ekaterina; Luchinsky, Dmitry; Khasin, Michael; Osipov, Viatcheslav V.; Smelyanskiy, Vadim N.

2012-01-01

In this report the main physics processes in LH2 tank during prepress and rocket flight are studied. The goal of this investigation is to analyze possible hazards and to make risk assessment in proposed LH2 tank designs for SLS with 5 engines (the situation with 4 engines is less critical). For analysis we use the multinode model (MNM) developed by us and presented in a separate report and also 3D ANSYS simulations. We carry out simulation and theoretical analysis the physics processes such as (i) accumulation of bubbles in LH2 during replenish stage and their collapsing in the liquid during the prepress; (ii) condensation-evaporation at the liquid-vapor interface and tank wall, (iv) heating the liquid near the interface and wall due to condensation and environment heat, (v) injection of hot He during prepress and of hot GH2 during flight, (vi) mixing and cooling of the injected gases due to heat transfer between the gases, liquid and the tank wall. We analyze the effects of these physical processes on the thermo- and fluid gas dynamics in the ullage and on the stratification of temperature in the liquid and assess the associated hazards. A special emphasize is put on the scaling predictions for the larger SLS LH2 tank.

Excitonic polarons in quasi-one-dimensional LH1 and LH2 bacteriochlorophyll a antenna aggregates from photosynthetic bacteria: A wavelength-dependent selective spectroscopy study

International Nuclear Information System (INIS)

Freiberg, Arvi; Raetsep, Margus; Timpmann, Kou; Trinkunas, Gediminas

2009-01-01

Spectral characteristics of the optically excited states in the ring-shaped quasi-one-dimensional aggregates comprising 18 and 32 tightly coupled bacteriochlorophyll a molecules have been investigated using selective spectroscopy methods and theoretical modelling of the data. Distinguished by the lowest electronic transition energies in the LH2 and LH1 antenna complexes these aggregates govern the functionally important ultrafast funneling of solar excitation energy in the photosynthetic membranes of purple bacteria. It was found by using a sophisticated differential fluorescence line narrowing method that exciton-phonon coupling in terms of the dimensionless Huang-Rhys factor is strong in these systems, justifying an excitonic polaron theoretical approach for the data analysis. Although we reached this qualitative conclusion already previously, in this work essential dependence of the exciton-phonon coupling strength and reorganization energy on excitation wavelength as well as on excitation light fluence has been established. We then show that these results corroborate with the properties of excitonic polarons in diagonally disordered ensembles of the aggregates. Furthermore, the weighted density of states of the phonon modes, which is an important characteristic of dynamical systems interacting with their surroundings, was derived. Its shape, being similar for all studied circular aggregates, deviates significantly from a reference profile describing local response of a protein to the Q y electronic transition in a single bacteriochlorophyll a molecule. Similarities of the data for regular and B800 deficient mutant LH2 complexes indicate that the B800 pigments have no direct influence on the electronic states of the B850 aggregate system. Consistent set of model parameters was determined, unambiguously implying that excitonic polarons, rather than bare excitons are proper lowest-energy optical excitations in the LH1 and LH2 antenna complexes

Excitonic polarons in quasi-one-dimensional LH1 and LH2 bacteriochlorophyll a antenna aggregates from photosynthetic bacteria: A wavelength-dependent selective spectroscopy study

Energy Technology Data Exchange (ETDEWEB)

Freiberg, Arvi [Institute of Physics, University of Tartu, Riia 142, 51014 Tartu (Estonia); Institute of Molecular and Cell Biology, University of Tartu, Riia 23, 51010 Tartu (Estonia)], E-mail: arvi.freiberg@ut.ee; Raetsep, Margus; Timpmann, Kou [Institute of Physics, University of Tartu, Riia 142, 51014 Tartu (Estonia); Trinkunas, Gediminas [Insitute of Physics, Savanoriu pr. 231, LT-02300 Vilnius (Lithuania)

2009-02-23

Spectral characteristics of the optically excited states in the ring-shaped quasi-one-dimensional aggregates comprising 18 and 32 tightly coupled bacteriochlorophyll a molecules have been investigated using selective spectroscopy methods and theoretical modelling of the data. Distinguished by the lowest electronic transition energies in the LH2 and LH1 antenna complexes these aggregates govern the functionally important ultrafast funneling of solar excitation energy in the photosynthetic membranes of purple bacteria. It was found by using a sophisticated differential fluorescence line narrowing method that exciton-phonon coupling in terms of the dimensionless Huang-Rhys factor is strong in these systems, justifying an excitonic polaron theoretical approach for the data analysis. Although we reached this qualitative conclusion already previously, in this work essential dependence of the exciton-phonon coupling strength and reorganization energy on excitation wavelength as well as on excitation light fluence has been established. We then show that these results corroborate with the properties of excitonic polarons in diagonally disordered ensembles of the aggregates. Furthermore, the weighted density of states of the phonon modes, which is an important characteristic of dynamical systems interacting with their surroundings, was derived. Its shape, being similar for all studied circular aggregates, deviates significantly from a reference profile describing local response of a protein to the Q{sub y} electronic transition in a single bacteriochlorophyll a molecule. Similarities of the data for regular and B800 deficient mutant LH2 complexes indicate that the B800 pigments have no direct influence on the electronic states of the B850 aggregate system. Consistent set of model parameters was determined, unambiguously implying that excitonic polarons, rather than bare excitons are proper lowest-energy optical excitations in the LH1 and LH2 antenna complexes.

LH Dynamics in Overweight Girls with Premature Adrenarche and Slowly Progressive Sexual Precocity

Directory of Open Access Journals (Sweden)

Rosenfield RobertL

2010-08-01

Full Text Available Background. Excess adiposity and premature adrenarche (PA are risk factors for the development of polycystic ovary syndrome (PCOS. Methods. Girls with slowly progressive precocious breast development, who were overweight and had PA (SPPOPA, 6.2–8.2 years, , overweight PA (6.6–10.8 years, , and overweight premenarcheal controls (OW-PUB, 10.6–12.8 years, underwent hormonal sleep testing and GnRH agonist (GnRHag and ACTH tests. Results. Despite an insignificant sleep-related increase in LH and prepubertal baseline hormone levels, SPPOPA peak LH and estradiol responses to GnRHag were intermediate between those of PA and OW-PUB, the LH being significantly different from both. Conclusions. GnRHag tests indicate that SPPOPA is a slowly progressive form of true puberty with blunted LH dynamics. These results argue against the prepubertal hyperandrogenism of excess adiposity or PA enhancing LH secretion or causing ovarian hyperandrogenism prior to menarche. Excess adiposity may contribute to both the early onset and slow progression of puberty.

Apolipoprotein E4 reduces evoked hippocampal acetylcholine release in adult mice

Czech Academy of Sciences Publication Activity Database

Dolejší, Eva; Liraz, O.; Rudajev, Vladimír; Zimčík, Pavel; Doležal, Vladimír; Michaelson, D. M.

2016-01-01

Roč. 136, č. 3 (2016), s. 503-509 ISSN 0022-3042 R&D Projects: GA MŠk(CZ) LH13269 Institutional support: RVO:67985823 Keywords : acetylcholine release * Alzheimer's disease (AD) * apolipoprotein E4 (apoE4) * hippocampus Subject RIV: FH - Neurology Impact factor: 4.083, year: 2016

The pattern of LH secretion and the ovarian response to the 'ram effect' in the anoestrous ewe is influenced by body condition but not by short-term nutritional supplementation.

Science.gov (United States)

Scaramuzzi, R J; Oujagir, L; Menassol, J-B; Freret, S; Piezel, A; Brown, H M; Cognié, J; Fabre Nys, C

2014-10-01

In sheep, the 'ram effect' induces out-of-season fertility and good nutrition increases prolificacy. This experiment determined if fatness or short-term nutritional supplementation modified the response to the 'ram effect'. A group of 48 Île-de-France ewes were fed diets that produced groups with body-condition scores (BCS) of >3.0 and <2.0. Within each BCS group animals were supplemented daily with 500g of lupins from Day -5 to Day 0 (ram introduction) resulting in four groups: low BCS, supplemented (n=7) and non-supplemented (n=8) and high BCS, supplemented (n=12) and non-supplemented (n=11). The blood concentrations of glucose and insulin and the LH response to gonadotrophin-releasing hormone (GnRH) were determined. After the 'ram effect' the pattern of LH pulsatility, the LH surge and ovarian responses were analysed. Low BCS ewes had lower glucose and insulin (P<0.001) and supplementation increased both (P≤0.001). The increase in LH induced by GnRH was reduced in low BCS ewes (P=0.015) but it was not affected by supplementation. Similarly, LH pulsatility was reduced in low BCS ewes (P<0.05). The LH surge and ovarian cyclicity were not affected but the follow-up cycle was delayed (P=0.034) and progesterone was reduced (P=0.029) in low BCS ewes. There was an effect of BCS on ovulation rate (P<0.05). These results show that the BCS can modify the response to the 'ram effect' and that supplementation has little effect on this response.

Early postnatal treatment of hypogonadotropic hypogonadism with recombinant human FSH and LH

DEFF Research Database (Denmark)

Main, Katharina M; Schmidt, Ida M; Toppari, Jorma

2002-01-01

BACKGROUND: Patients with hypogonadotropic hypogonadism may be diagnosed shortly after birth because of micropenis and cryptorchidism, combined with subnormal LH and FSH concentrations during the postnatal period. OBJECTIVE: To investigate whether treating these patients with gonadotropins postna...... observed. CONCLUSIONS: Gonadotropin treatment in an infant with hypogonadotropic hypogonadism succeeded in inducing an increase in inhibin B and testicular growth.......BACKGROUND: Patients with hypogonadotropic hypogonadism may be diagnosed shortly after birth because of micropenis and cryptorchidism, combined with subnormal LH and FSH concentrations during the postnatal period. OBJECTIVE: To investigate whether treating these patients with gonadotropins...... the normal range (0.05-0.17 IU/l and 79-112 pg/ml respectively). METHODS: From 7.9 to 13.7 months of age, the patient was treated with recombinant human LH and FSH in doses of 20 and 21.3 IU s.c. twice weekly respectively. RESULTS: During treatment concentrations of LH, FSH, inhibin B and estradiol increased...

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

Science.gov (United States)

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

2001-12-01

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

Evolution of Edge Pedestal Profiles Over the L-H Transition

Science.gov (United States)

Sayer, M. S.; Stacey, W. M.; Floyd, J. P.; Groebner, R. J.

2012-10-01

The detailed time evolution of thermal diffusivities, electromagnetic forces, pressure gradients, particle pinch and momentum transport frequencies (which determine the diffusion coefficient) have been analyzed during the L-H transition in a DIII-D discharge. Density, temperature, rotation velocity and electric field profiles at times just before and after the L-H transition are analyzed in terms of these quantities. The analysis is based on the fluid particle balance, energy balance, force balance and heat conduction equations, as in Ref. [1], but with much greater time resolution and with account for thermal ion orbit loss. The variation of diffusive and non-diffusive transport over the L-H transition is determined from the variation in the radial force balance (radial electric field, VxB force, and pressure gradient) and the variation in the interpreted diffusive transport coefficients. 6pt [1] W.M. Stacey and R.J. Groebner, Phys. Plasmas 17, 112512 (2010).

Dietary lipid and cholesterol induce ovarian dysfunction and abnormal LH response to stimulation in rabbits.

Directory of Open Access Journals (Sweden)

Anne-Gaël Cordier

Full Text Available BACKGROUND/AIM: Excess of fat intake is dramatically increasing in women of childbearing age and results in numerous health complications, including reproductive disorders. Using rabbit does as a biomedical model, the aim of this study was to evaluate onset of puberty, endocrine responses to stimulation and ovarian follicular maturation in females fed a high fat high cholesterol diet (HH diet from 10 weeks of age (i.e., 2 weeks before normal onset of puberty or a control diet (C diet. METHODOLOGY/PRINCIPAL FINDINGS: Three experiments were performed, each including 8 treated (HH group and 8 control (C group does. In experiment 1, the endocrine response to Gonadotropin releasing hormone (GnRH was evaluated at 13, 18 and 22 weeks of age. In experiment 2, the follicular population was counted in ovaries of adult females (18 weeks of age. In experiment 3, the LH response to mating and steroid profiles throughout gestation were evaluated at 18 weeks of age. Fetal growth was monitored by ultrasound and offspring birth weight was recorded. Data showed a significantly higher Luteinizing hormone (LH response after induction of ovulation at 13 weeks of age in the HH group. There was no difference at 18 weeks, but at 22 weeks, the LH response to GnRH was significantly reduced in the HH group. The number of atretic follicles was significantly increased and the number of antral follicles significantly reduced in HH does vs. controls. During gestation, the HH diet induced intra-uterine growth retardation (IUGR. CONCLUSION: The HH diet administered from before puberty onwards affected onset of puberty, follicular growth, hormonal responses to breeding and GnRH stimulation in relation to age and lead to fetal IUGR.

ASASSN-15LH: A SUPERLUMINOUS ULTRAVIOLET REBRIGHTENING OBSERVED BY SWIFT AND HUBBLE

Energy Technology Data Exchange (ETDEWEB)

Brown, Peter J.; Yang, Yi; Wang, Lifan [George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A. and M. University, Department of Physics and Astronomy, 4242 TAMU, College Station, TX 77843 (United States); Cooke, Jeff; Mould, Jeremy [Centre for Astrophysics and Supercomputing, Swinburne University, Hawthorn VIC 3122 (Australia); Olaes, Melanie; Quimby, Robert M. [Department of Astronomy, San Diego State University, San Diego, CA 92182 (United States); Baade, Dietrich [European Organisation for Astronomical Research in the Southern Hemisphere (ESO), Karl-Schwarzschild-Str. 2, D-85748 Garching b. München (Germany); Gehrels, Neil [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Hoeflich, Peter [Department of Physics, Florida State University, Tallahassee, FL 32306 (United States); Maund, Justyn [Department of Physics and Astronomy F39 Hicks Building, Hounsfield Road Sheffield, S3 7RH (United Kingdom); Wheeler, J. Craig [Department of Astronomy, University of Texas at Austin, Austin, TX 78712 (United States)

2016-09-01

We present and discuss ultraviolet and optical photometry from the Ultraviolet/Optical Telescope, X-ray limits from the X-Ray Telescope on Swift, and imaging polarimetry and ultraviolet/optical spectroscopy with the Hubble Space Telescope , all from observations of ASASSN-15lh. It has been classified as a hydrogen-poor superluminous supernova (SLSN I), making it more luminous than any other supernova observed. ASASSN-15lh is not detected in the X-rays in individual or co-added observations. From the polarimetry we determine that the explosion was only mildly asymmetric. We find the flux of ASASSN-15lh to increase strongly into the ultraviolet, with an ultraviolet luminosity 100 times greater than the hydrogen-rich, ultraviolet-bright SLSN II SN 2008es. We find that objects as bright as ASASSN-15lh are easily detectable beyond redshifts of ∼4 with the single-visit depths planned for the Large Synoptic Survey Telescope. Deep near-infrared surveys could detect such objects past a redshift of ∼20, enabling a probe of the earliest star formation. A late rebrightening—most prominent at shorter wavelengths—is seen about two months after the peak brightness, which is itself as bright as an SLSN. The ultraviolet spectra during the rebrightening are dominated by the continuum without the broad absorption or emission lines seen in SLSNe or tidal disruption events (TDEs) and the early optical spectra of ASASSN-15lh. Our spectra show no strong hydrogen emission, showing only Ly α absorption near the redshift previously found by optical absorption lines of the presumed host. The properties of ASASSN-15lh are extreme when compared to either SLSNe or TDEs.

Initial results of high resolution L-H transition studies on DIII-D

International Nuclear Information System (INIS)

Wang, G; Rhodes, T L; Doyle, E J; Peebles, W A; Zeng, L; Burrell, K H; McKee, G R; Groebner, R J; Evans, T E

2004-01-01

Understanding the L-H transition in tokamaks has been an important area of research for more than two decades. High time resolution diagnostics on DIII-D allow detailed characterization of the L-H transition and, therefore, testing and benchmarking of theoretical models. An experiment was performed in DIII-D utilizing a novel, high temporal and spatial resolution reflectometer density profile system to measure densities from the SOL to the inside separatrix. Initial data analysis indicates different density profile evolution during L-H transitions in upper single-null and lower single-null divertor configuration plasmas. A detailed comparison of the density gradient and fluctuation changes is presented for these two cases

Initial results of high resolution L-H transition studies on DIII-D

Energy Technology Data Exchange (ETDEWEB)

Wang, G [Department of Electrical Engineering and PSTI, University of California, Los Angeles, CA 90095 (United States); Rhodes, T L [Department of Electrical Engineering and PSTI, University of California, Los Angeles, CA 90095 (United States); Doyle, E J [Department of Electrical Engineering and PSTI, University of California, Los Angeles, CA 90095 (United States); Peebles, W A [Department of Electrical Engineering and PSTI, University of California, Los Angeles, CA 90095 (United States); Zeng, L [Department of Electrical Engineering and PSTI, University of California, Los Angeles, CA 90095 (United States); Burrell, K H [General Atomics, PO Box 85608, San Diego, CA 92186 (United States); McKee, G R [University of Wisconsin-Madison, 1500 Engineering Drive, Madison, WI 53706 (United States); Groebner, R J [General Atomics, PO Box 85608, San Diego, CA 92186 (United States); Evans, T E [General Atomics, PO Box 85608, San Diego, CA 92186 (United States)

2004-05-01

Understanding the L-H transition in tokamaks has been an important area of research for more than two decades. High time resolution diagnostics on DIII-D allow detailed characterization of the L-H transition and, therefore, testing and benchmarking of theoretical models. An experiment was performed in DIII-D utilizing a novel, high temporal and spatial resolution reflectometer density profile system to measure densities from the SOL to the inside separatrix. Initial data analysis indicates different density profile evolution during L-H transitions in upper single-null and lower single-null divertor configuration plasmas. A detailed comparison of the density gradient and fluctuation changes is presented for these two cases.

High Specific Power Motors in LN2 and LH2

Science.gov (United States)

Brown, Gerald V.; Jansen, Ralph H.; Trudell, Jeffrey J.

2007-01-01

A switched reluctance motor has been operated in liquid nitrogen (LN2) with a power density as high as that reported for any motor or generator. The high performance stems from the low resistivity of Cu at LN2 temperature and from the geometry of the windings, the combination of which permits steady-state rms current density up to 7000 A/sq cm, about 10 times that possible in coils cooled by natural convection at room temperature. The Joule heating in the coils is conducted to the end turns for rejection to the LN2 bath. Minimal heat rejection occurs in the motor slots, preserving that region for conductor. In the end turns, the conductor layers are spaced to form a heat-exchanger-like structure that permits nucleate boiling over a large surface area. Although tests were performed in LN2 for convenience, this motor was designed as a prototype for use with liquid hydrogen (LH2) as the coolant. End-cooled coils would perform even better in LH2 because of further increases in copper electrical and thermal conductivities. Thermal analyses comparing LN2 and LH2 cooling are presented verifying that end-cooled coils in LH2 could be either much longer or could operate at higher current density without thermal runaway than in LN2.

Characterisation of the LH2 spectral variants produced by the photosynthetic purple sulphur bacterium Allochromatium vinosum.

Science.gov (United States)

Carey, Anne-Marie; Hacking, Kirsty; Picken, Nichola; Honkanen, Suvi; Kelly, Sharon; Niedzwiedzki, Dariusz M; Blankenship, Robert E; Shimizu, Yuuki; Wang-Otomo, Zheng-Yu; Cogdell, Richard J

2014-11-01

This study systematically investigated the different types of LH2 produced by Allochromatium (Alc.) vinosum, a photosynthetic purple sulphur bacterium, in response to variations in growth conditions. Three different spectral forms of LH2 were isolated and purified, the B800-820, B800-840 and B800-850 LH2 types, all of which exhibit an unusual split 800 peak in their low temperature absorption spectra. However, it is likely that more forms are also present. Relatively more B800-820 and B800-840 are produced under low light conditions, while relatively more B800-850 is produced under high light conditions. Polypeptide compositions of the three different LH2 types were determined by a combination of HPLC and TOF/MS. The B800-820, B800-840 and B800-850 LH2 types all have a heterogeneous polypeptide composition, containing multiple types of both α and β polypeptides, and differ in their precise polypeptide composition. They all have a mixed carotenoid composition, containing carotenoids of the spirilloxanthin series. In all cases the most abundant carotenoid is rhodopin; however, there is a shift towards carotenoids with a higher conjugation number in LH2 complexes produced under low light conditions. CD spectroscopy, together with the polypeptide analysis, demonstrates that these Alc. vinosum LH2 complexes are more closely related to the LH2 complex from Phs. molischianum than they are to the LH2 complexes from Rps. acidophila. Copyright © 2014. Published by Elsevier B.V.

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

International Nuclear Information System (INIS)

Marche, Pierre.

1975-01-01

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

Fluorescence spectral fluctuations of single LH2 complexes from Rhodopseudomonas acidophila strain 10050

NARCIS (Netherlands)

Rutkauskas, D.; Novoderezkhin, V.; Cogdell, R.J.; van Grondelle, R.

2004-01-01

We have investigated the energy landscape of the bacterial photosynthetic peripheral light-harvesting complex LH2 of purple bacterium Rhodopseudomonas acidophila by monitoring sequences of fluorescence spectra of single LH2 assemblies, at room temperature, with different excitation intensities as

Neurokinin-3 Receptor Activation in the Retrochiasmatic Area is Essential for the Full Preovulatory LH Surge in Ewes

Science.gov (United States)

Porter, Katrina L.; Hileman, Stanley M.; Hardy, Steven L.; Nestor, Casey C; Lehman, Michael N.; Goodman, Robert L.

2014-01-01

Neurokinin B (NKB) is essential for human reproduction and has been shown to stimulate LH secretion in several species, including sheep. Ewes express the neurokinin-3 receptor (NK3R) in the retrochiasmatic area (RCh) and there is one report that placement of senktide, an NK3R agonist, therein stimulates LH secretion that resembles an LH surge in ewes. In this study, we first confirmed that local administration of senktide to the RCh produced a surge-like increase in LH secretion, and then tested the effects of this agonist in two other areas implicated in the control of LH secretion and where NK3R is found in high abundance: the preoptic area (POA) and arcuate nucleus (ARC). Bilateral microimplants containing senktide induced a dramatic surge-like increase in LH when given in the POA similar to that seen with RCh treatment. In contrast, senktide treatment in the ARC resulted in a much smaller, but significant, increase in LH concentrations suggestive of an effect on tonic secretion. The possible role of POA and RCh NK3R activation in the LH surge was next tested by treating ewes with SB222200, an NK3R antagonist, in each area during an E2-induced LH surge. SB222200 in the RCh, but not in the POA, reduced LH surge amplitude by about 40% compared to controls, indicating that NK3R activation in the former region is essential for full expression of the preovulatory LH surge. Based on these data, we propose that NKB actions in the RCh are an important component of the preovulatory LH surge in ewes. PMID:25040132

Both recombinant African catfish LH and FSH are able to activate the African catfish FSH receptor

NARCIS (Netherlands)

Vischer, HF; Granneman, JCM; Linskens, MHK; Schulz, RW; Bogerd, J

LH and FSH are heterodimeric glycoprotein hormones, composed of a common alpha-subunit non-covalently associated with a hormone-specific beta-subunit. Repeated efforts to isolate catfish FSH (cfFSH) have not been successful and only catfish LH (cfLH) has been purified from catfish pituitaries.

Dynamics of energy transfer from lycopene to bacteriochlorophyll in genetically-modified LH2 complexes of Rhodobacter sphaeroides.

Science.gov (United States)

Hörvin Billsten, H; Herek, J L; Garcia-Asua, G; Hashøj, L; Polívka, T; Hunter, C N; Sundström, V

2002-03-26

LH2 complexes from Rb. sphaeroides were modified genetically so that lycopene, with 11 saturated double bonds, replaced the native carotenoids which contain 10 saturated double bonds. Tuning the S1 level of the carotenoid in LH2 in this way affected the dynamics of energy transfer within LH2, which were investigated using both steady-state and time-resolved techniques. The S1 energy of lycopene in n-hexane was determined to be approximately 12 500 +/- 150 cm(-1), by direct measurement of the S1-S2 transient absorption spectrum using a femtosecond IR-probing technique, thus placing an upper limit on the S1 energy of lycopene in the LH2 complex. Fluorescence emission and excitation spectra demonstrated that energy can be transferred from lycopene to the bacteriochlorophyll molecules within this LH2 complex. The energy-transfer dynamics within the mutant complex were compared to wild-type LH2 from Rb. sphaeroides containing the carotenoid spheroidene and from Rs. molischianum, in which lycopene is the native carotenoid. The results show that the overall efficiency for Crt --> B850 energy transfer is approximately 80% in lyco-LH2 and approximately 95% in WT-LH2 of Rb. sphaeroides. The difference in overall Crt --> BChl transfer efficiency of lyco-LH2 and WT-LH2 mainly relates to the low efficiency of the Crt S(1) --> BChl pathway for complexes containing lycopene, which was 20% in lyco-LH2. These results show that in an LH2 complex where the Crt S1 energy is sufficiently high to provide efficient spectral overlap with both B800 and B850 Q(y) states, energy transfer via the Crt S1 state occurs to both pigments. However, the introduction of lycopene into the Rb. sphaeroides LH2 complex lowers the S1 level of the carotenoid sufficiently to prevent efficient transfer of energy to the B800 Q(y) state, leaving only the Crt S1 --> B850 channel, strongly suggesting that Crt S1 --> BChl energy transfer is controlled by the relative Crt S1 and BChl Q(y) energies.

Neurosteroids, trigger of the LH surge

Science.gov (United States)

Kuo, John; Micevych, Paul

2012-01-01

Recent experiments from our laboratory are consistent with the idea that hypothalamic astrocytes are critical components of the central nervous system (CNS) mediated estrogen positive feedback mechanism. The “astrocrine hypothesis” maintains that ovarian estradiol rapidly increases free cytoplasmic calcium concentrations ([Ca2+]i) that facilitate progesterone synthesis in astrocytes. This hypothalamic neuroprogesterone along with the elevated estrogen from the ovaries allows for the surge release of gonadotropin-releasing hormone (GnRH) that triggers the pituitary luteinizing hormone (LH) surge. A narrow range of estradiol stimulated progesterone production supports an “off-on-off” mechanism regulating the transition from estrogen negative feedback to estrogen positive feedback, and back again. The rapidity of the [Ca2+]i response and progesterone synthesis support a non-genomic, membrane-initiated signaling mechanism. In hypothalamic astrocytes, membrane-associated estrogen receptors (mERs) signal through transactivation of the metabotropic glutamate receptor type 1a (mGluR1a), implying that astrocytic function is influenced by surrounding glutamatergic nerve terminals. Although other putative mERs, such as mERβ, STX-activated mER-Gαq, and G protein-coupled receptor 30 (GPR30), are present and participate in membrane-mediated signaling, their influence in reproduction is still obscure since female reproduction be it estrogen positive feedback or lordosis behavior requires mERα. The astrocrine hypothesis is also consistent with the well-known sexual dimorphism of estrogen positive feedback. In rodents, only post-pubertal females exhibit this positive feedback. Hypothalamic astrocytes cultured from females, but not males, responded to estradiol by increasing progesterone synthesis. Estrogen autoregulates its own signaling by regulating levels of mERα in the plasma membrane of female astrocytes. In male astrocytes, the estradiol-induced increase in m

Quiet Periods in Edge Turbulence Preceding the L-H Transition in NSTX

International Nuclear Information System (INIS)

Zweben, S.; Maqueda, R.J.; Hager, R.; Hallatschek, K.; Kaye, S.M.; Munsat, T.; Poli, F.M.; Roquemore, A.L.; Sechrest, Y.; Stotler, D.P.

2010-01-01

This paper describes the first observations in NSTX of 'quiet periods' in the edge turbulence preceding the L-H transition, as diagnosed by the GPI diagnostic near the outer midplane separatrix. During these quiet periods the GPI D light emission pattern was transiently similar to that seen during Hmode, i.e. with a relatively small fraction of the GPI light emission located outside the separatrix. These quiet periods had a frequency of ∼3 kHz for at least 30 msec before the L-H transition, and were correlated with changes in the direction of the local poloidal velocity. The GPI turbulence images were also analyzed to obtain an estimate for the dimensionless poloidal shearing S =(dVp/dr)(Lr/Lp). The values of S were strongly modulated by the quiet periods, but not otherwise varying for at least 30 msec preceding the L-H transition. Since neither the quiet periods nor the shear flow increased significantly immediately preceding the L-H transition, neither of these appears to be the trigger for this transition, at least for these cases in NSTX.

Modeling of LH current drive in self-consistent elongated tokamak MHD equilibria

International Nuclear Information System (INIS)

Blackfield, D.T.; Devoto, R.S.; Fenstermacher, M.E.; Bonoli, P.T.; Porkolab, M.; Yugo, J.

1989-01-01

Calculations of non-inductive current drive typically have been used with model MHD equilibria which are independently generated from an assumed toroidal current profile or from a fit to an experiment. Such a method can lead to serious errors since the driven current can dramatically alter the equilibrium and changes in the equilibrium B-fields can dramatically alter the current drive. The latter effect is quite pronounced in LH current drive where the ray trajectories are sensitive to the local values of the magnetic shear and the density gradient. In order to overcome these problems, we have modified a LH simulation code to accommodate elongated plasmas with numerically generated equilibria. The new LH module has been added to the ACCOME code which solves for current drive by neutral beams, electric fields, and bootstrap effects in a self-consistent 2-D equilibrium. We briefly describe the model in the next section and then present results of a study of LH current drive in ITER. 2 refs., 6 figs., 2 tabs

Preovulatory progesterone concentration associates significantly to follicle number and LH concentration but not to pregnancy rate

DEFF Research Database (Denmark)

Yding Andersen, Claus; Bungum, Leif; Nyboe Andersen, Anders

2011-01-01

Using data from a large prospective randomized controlled trial that evaluated the effect of recombinant LH (rLH)co-administration for ovarian stimulation, the present study assessed whether progesterone concentration on the day of human chorionic gonadotrophin (HCG) administration was associated...... with or without rLH administration from day 6 of stimulation. There was no significant association between the late-follicular-phase progesterone concentration and the clinical pregnancy rate. However, progesterone concentration was strongly associated with the number of follicles and retrieved oocytes. Late......-follicular-phase LH concentration also showed a significant positive association with progesterone concentration (P = 0.018). Administration of rLH during ovarian stimulation did not affect progesterone concentration. The present study does not support an association between progesterone concentration on the day...

Cost-effectiveness analysis on the use of rFSH + rLH for the treatment of anovulation in hypogonadotropic hypogonadal women

Directory of Open Access Journals (Sweden)

Papaleo E

2014-06-01

Full Text Available Enrico Papaleo,1 Carlo Alviggi,2 Giorgio Lorenzo Colombo,3,4 Claudio Pisanelli,5,6 Claudio Ripellino,7 Salvatore Longobardi,8 Pier Luigi Canonico91Centro Scienze della Natalità, Gynecological-Obstetrics Department, San Raffaele Hospital, Vita-Salute San Raffaele, Milan, Italy; 2Department of Neuroscience, Reproductive Sciences and Odontostomatology, University “Federico II” of Naples, Naples, Italy; 3Department of Drug Sciences, University of Pavia, Pavia, Italy; 4SAVE Studi Analisi Valutazioni Economiche, Milan, Italy; 5ACO San Filippo Neri, Rome, Italy; 6Società Italiana Di Farmacia Ospedaliera, Milan, Italy; 7CSD Medical Research Srl, Milan, Italy; 8Medical Department, Merck Serono SpA, Rome, Italy; 9Department of Pharmaceutical Sciences, University of Piemonte Orientale, Novara, Italy Background: Hypogonadotropic hypogonadal women are characterized by ovarian functionality deficiency, caused by low concentrations of follicle-stimulating hormone (FSH and luteinizing hormone (LH. To recover reproduction functionality, recommended therapies for ovarian induction involve injections of FSH and LH medications. Objective: Since important differences exist between recombinant and urinary gonadotropin therapies in terms of efficacy and cost, the objective of this study was to develop a cost-effectiveness model to compare recombinant FSH (rFSH + recombinant LH (rLH and highly purified human menopausal gonadotropin (HP-HMG. Methods: A Markov model was developed, considering three cycles of therapy; probability of pregnancy and miscarriage were considered, and the efficacy was evaluated in terms of pregnancy occurrence. The perspective of the model was that of the Italian Health Service, so only direct cost (drugs, specialist visits, patient examinations, and hospitalizations were included. Results: rFSH + rLH is associated with a higher total cost (€3,453.50 and higher efficacy (0.87 compared with HP-HMG (€2,719.70 and 0.50. rFSH + rLH

Comparison of L-H transition measurements with physics models

International Nuclear Information System (INIS)

Carlstrom, T.N.; Burrell, K.H.; Groebner, R.J.; Leonard, A.W.; Osborne, T.H.; Thomas, D.M.

1998-12-01

A technique of fitting a modified hyperbolic tangent to the edge profiles has improved the localization of plasma edge parameters. Non-dimensional edge parameters are broadly consistent with several theories of the L-H transition that use edge gradients in their formulation of a critical threshold parameter. The ion ∇B drift direction has only a small effect on the edge plasma conditions measured near the plasma midplane but a large effect on the divertor plasma. The dramatic change of power threshold with the direction of the ion ∇B drift implies that phenomena in the divertor region may be critical for the L-H transition

Impact of the lipid bilayer on energy transfer kinetics in the photosynthetic protein LH2.

Science.gov (United States)

Ogren, John I; Tong, Ashley L; Gordon, Samuel C; Chenu, Aurélia; Lu, Yue; Blankenship, Robert E; Cao, Jianshu; Schlau-Cohen, Gabriela S

2018-03-28

Photosynthetic purple bacteria convert solar energy to chemical energy with near unity quantum efficiency. The light-harvesting process begins with absorption of solar energy by an antenna protein called Light-Harvesting Complex 2 (LH2). Energy is subsequently transferred within LH2 and then through a network of additional light-harvesting proteins to a central location, termed the reaction center, where charge separation occurs. The energy transfer dynamics of LH2 are highly sensitive to intermolecular distances and relative organizations. As a result, minor structural perturbations can cause significant changes in these dynamics. Previous experiments have primarily been performed in two ways. One uses non-native samples where LH2 is solubilized in detergent, which can alter protein structure. The other uses complex membranes that contain multiple proteins within a large lipid area, which make it difficult to identify and distinguish perturbations caused by protein-protein interactions and lipid-protein interactions. Here, we introduce the use of the biochemical platform of model membrane discs to study the energy transfer dynamics of photosynthetic light-harvesting complexes in a near-native environment. We incorporate a single LH2 from Rhodobacter sphaeroides into membrane discs that provide a spectroscopically amenable sample in an environment more physiological than detergent but less complex than traditional membranes. This provides a simplified system to understand an individual protein and how the lipid-protein interaction affects energy transfer dynamics. We compare the energy transfer rates of detergent-solubilized LH2 with those of LH2 in membrane discs using transient absorption spectroscopy and transient absorption anisotropy. For one key energy transfer step in LH2, we observe a 30% enhancement of the rate for LH2 in membrane discs compared to that in detergent. Based on experimental results and theoretical modeling, we attribute this difference to

LH prevents cisplatin-induced apoptosis in oocytes and preserves female fertility in mouse

Science.gov (United States)

Rossi, Valerio; Lispi, Monica; Longobardi, Salvatore; Mattei, Maurizio; Rella, Francesca Di; Salustri, Antonietta; De Felici, Massimo; Klinger, Francesca G

2017-01-01

Premature ovarian failure and female infertility are frequent side effects of anticancer therapies, owing to the extreme sensitivity of the ovarian reserve oocytes to the damaging effects of irradiation and chemotherapy on DNA. We report here a robust protective effect of luteinizing hormone (LH) on the primordial follicle pool of prepubertal ovaries against the cisplatin (Cs)-induced apoptosis. In vitro LH treatment of prepubertal ovarian fragments generated anti-apoptotic signals by a subset of ovarian somatic cells expressing LH receptor (LHR) through cAMP/PKA and Akt pathways. Such signals, reducing the oocyte level of pro-apoptotic TAp63 protein and favoring the repair of the Cs-damaged DNA in the oocytes, prevented their apoptosis. Noteworthy, in vivo administration to prepubertal female mice of a single dose of LH together with Cs inhibited the depletion of the primordial follicle reserve caused by the drug and preserved their fertility in reproductive age, preventing significant alteration in the number of pregnancy and of delivered pups. In conclusion, these findings establish a novel ovoprotective role for LH and further support the very attracting prospective to use physiological 'fertoprotective' approaches for preventing premature infertility and risks linked to precocious menopause in young patients who survived cancer after chemotherapy. PMID:27689876

LH prevents cisplatin-induced apoptosis in oocytes and preserves female fertility in mouse.

Science.gov (United States)

Rossi, Valerio; Lispi, Monica; Longobardi, Salvatore; Mattei, Maurizio; Rella, Francesca Di; Salustri, Antonietta; De Felici, Massimo; Klinger, Francesca G

2017-01-01

Premature ovarian failure and female infertility are frequent side effects of anticancer therapies, owing to the extreme sensitivity of the ovarian reserve oocytes to the damaging effects of irradiation and chemotherapy on DNA. We report here a robust protective effect of luteinizing hormone (LH) on the primordial follicle pool of prepubertal ovaries against the cisplatin (Cs)-induced apoptosis. In vitro LH treatment of prepubertal ovarian fragments generated anti-apoptotic signals by a subset of ovarian somatic cells expressing LH receptor (LHR) through cAMP/PKA and Akt pathways. Such signals, reducing the oocyte level of pro-apoptotic TAp63 protein and favoring the repair of the Cs-damaged DNA in the oocytes, prevented their apoptosis. Noteworthy, in vivo administration to prepubertal female mice of a single dose of LH together with Cs inhibited the depletion of the primordial follicle reserve caused by the drug and preserved their fertility in reproductive age, preventing significant alteration in the number of pregnancy and of delivered pups. In conclusion, these findings establish a novel ovoprotective role for LH and further support the very attracting prospective to use physiological 'fertoprotective' approaches for preventing premature infertility and risks linked to precocious menopause in young patients who survived cancer after chemotherapy.

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

Science.gov (United States)

Shargil, A A

1987-03-01

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

Experimental study of temperature sensor for an ocean-going liquid hydrogen (LH2) carrier

Science.gov (United States)

Nakano, A.; Shimazaki, T.; Sekiya, M.; Shiozawa, H.; Aoyagi, A.; Ohtsuka, K.; Iwakiri, T.; Mikami, Z.; Sato, M.; Kinoshita, K.; Matsuoka, T.; Takayama, Y.; Yamamoto, K.

2018-04-01

The prototype temperature sensors for an ocean-going liquid hydrogen (LH2) carrier were manufactured by way of trial. All of the sensors adopted Platinum 1000 (PT-1000) resistance thermometer elements. Various configurations of preproduction temperature sensors were tested in AIST's LH2 test facility. In the experiments, a PT-1000 resistance thermometer, calibrated at the National Metrology Institute of Japan at AIST, was used as the standard thermometer. The temperatures measured by the preproduction sensors were compared with the temperatures measured by the standard thermometer, and the measurement accuracy of the temperature sensors in LH2 was investigated and discussed. It was confirmed that the measurement accuracies of the preproduction temperature sensors were within ±50 mK, which is the required measurement accuracy for a technical demonstration ocean-going LH2 carrier.

Functional LH1 antenna complexes influence electron transfer in bacterial photosynthetic reaction centers

NARCIS (Netherlands)

Visschers, R.W.; Vulto, S.I.E.; Jones, M.R.; van Grondelle, R.; Kraayenhof, R.

1999-01-01

The effect of the light harvesting 1 (LH1) antenna complex on the driving force for light-driven electron transfer in the Rhodobacter sphaeroides reaction center has been examined. Equilibrium redox titrations show that the presence of the LH1 antenna complex influences the free energy change for

Functional LH1 antenna complexes influence electron transfer in bacterial photosynthetic reaction centers.

NARCIS (Netherlands)

Visschers, R.W.; Vulto, S.I.E.; Jones, M.R.; van Grondelle, R.; Kraayenhof, R.

1999-01-01

The effect of the light harvesting 1 (LH1) antenna complex on the driving force for light-driven electron transfer in the Rhodobacter sphaeroides reaction center has been examined. Equilibrium redox titrations show that the presence of the LH1 antenna complex influences the free energy change for

LHRH and LH in peripubertal female rats following prenatal and/or postnatal ethanol exposure

International Nuclear Information System (INIS)

Morris, D.L.; Harms, P.G.; Petersen, H.D.; McArthur, N.H.

1989-01-01

The effects of pre- and postnatal exposure to ethanol (ETHO) on LHRH and LH were investigated. Pregnant and/or lactating dams were fed ETHOD during: (1) gestation, (2) lactation, or (3) gestation-lactation. Female offspring were decapitated at 30 or 40 days-of-age; trunk blood was collected for plasma LH RIA; and hypothalamic tissues were collected for LHRH RIA. Hypothalamic LHRH content of all ETOH-exposed groups was less than that of non-ETOH-fed controls at 30 and 40 days-of-age. Plasma LH concentrations of all ETOH-exposed groups were less than those of non-ETOD-fed controls at 30 and 40 days-of-age. Also, at 30 and 40 days-of-age, the plasma LH concentrations of the animals exposed to ETOH during lactation and gestation-lactation were less than those of the animals exposed to ETOH during gestation. These data suggest that ETOH exposure during gestation and/or lactation negatively affects hypothalamic LHRH content of femal rat offspring. Decreased hypothalamic LHRH content with corresponding lowered plasma LH concentration suggests that ETOH influences development or maturation of hypothalamic LHRH neurons by possibly decreasing their number or synthesizing capability

Photovoltaic Performance and Characteristics of Dye-Sensitized Solar Cells Prepared with the N719 Thermal Degradation Products Ru(LH)(2)(NCS)(4-tert-butylpyridine) N(Bu)(4) and Ru(LH)(2)(NCS)(1-methylbenzimidazole) N(Bu)(4)

DEFF Research Database (Denmark)

Nguyen, P. T.; Binh, X. T. L.; Andersen, A. R.

2011-01-01

The dye-sensitized solar cell N719 thermal degradation products [Ru(LH)(2)(NCS)(4-tert-butylpyridine)][N(Bu)(4)] (1) and [Ru(LH)(2)(NCS)(1-methylbenzimidazole)][N(Bu)(4)] (2) were synthesized from [Ru(LH)(2)(NCS)(2)][N(Bu)(4)](2) (N719), (L = 2,2'-bipyridyl-4,4'-dicarboxylic acid) and characterized...

The effect of dietary protein on reproduction in the mare. IV. Serum progestagen, FSH, LH and melatonin concentrations during the anovulatory, transitional and ovulatory periods in the non-pregnant mare

Directory of Open Access Journals (Sweden)

F.E. Van Niekerk

1997-07-01

Full Text Available The effect of total protein intake and protein quality on the serum concentrations of certain reproductive hormones during the anovulatory, transitional and ovulatory periods were studied in 36 Anglo-Arab mares. High-quality protein stimulated FSH and LH production during the late transitional period. Serum progestagen and melatonin concentrations were unaffected by the quality of protein nutrition during the anovulatory period. Mares receiving high-quality protein exhibited a 10-14-day cyclical pattern of FSH release approximately 4-6 weeks earlier than the mares fed the lower-quality protein diet, and also ovulated 3-4 weeks earlier than the mares on the lower-quality protein diet. Progesterone concentrations during the 1st oestrous cycle after the anovulatory period were unaffected by protein quality in the diet.

Effects of aggregation on the excitation dynamics of LH2 from Thermochromatium tepidum in aqueous phase and in chromatophores.

Science.gov (United States)

Yang, Fan; Yu, Long-Jiang; Wang, Peng; Ai, Xi-Cheng; Wang, Zheng-Yu; Zhang, Jian-Ping

2011-06-23

We carried out femtosecond magic-angle and polarized pump-probe spectroscopies for the light-harvesting complex 2 (LH2) from Thermochromatium (Tch.) tepidum in aqueous phase and in chromatophores. To examine the effects of LH2 aggregation on the dynamics of excitation energy transfer, dominant monodispersed and aggregated LH2s were prepared by controlling the surfactant concentrations. The aqueous preparations solubilized with different concentrations of n-dodecyl-β-D-maltoside (DDM) show similar visible-to-near-infrared absorption spectra, but distinctively different aggregation states, as revealed by using dynamic light scattering. The B800 → B850 intra-LH2 energy transfer time was determined to be 1.3 ps for isolated LH2, which, upon aggregation in aqueous phase or clustering in chromatophores, shortened to 1.1 or 0.9 ps, respectively. The light-harvesting complex 1 (LH1) of this thermophilic purple sulfur bacterium contains bacteriochlorophyll a absorbing at 915 nm (B915), and the LH2(B850) → LH1(B915) intercomplex transfer time in chromatophores was found to be 6.6 ps. For chromatophores, a depolarization time of 21 ps was derived from the anisotropy kinetics of B850*, which is attributed to the migration of B850* excitation before being trapped by LH1. In addition, the B850* annihilation is accelerated upon LH2 aggregation in aqueous phase, but it is much less severe upon LH2 clustering in the intracytoplasmic membrane. These results are helpful in understanding the light-harvesting function of a bacterial photosynthetic membrane incorporating different types of antenna complexes.

LH Pretreatment as a Novel Strategy for Poor Responders

Directory of Open Access Journals (Sweden)

Anna Pia Ferraretti

2014-01-01

Full Text Available Introduction. Poor response to ovarian stimulation is still a major problem in IVF. The study presents a new stimulation protocol evaluated in a suppopulation of very difficult young poor ovarian responders. Material and Methods. The study consists in two sections. The first includes data from a randomized controlled study involving forty-three young patients with a poor ovarian response in at least two previous cycles (intended as cycle cancellation or with ≤3 collected oocytes. Patients were randomized in two groups: group A (control received FSH (400 IU/day, while group B received the new stimulation protocol consisting in a sequential association of 150 IU r-LH for 4 days followed by 400 IU r-FSH/after downregulation with daily GnRh agonist. The second includes data from the overall results in 65 patients treated with the new protocol compared to their previous performance with conventional cycles (historical control. Results. Both in the RCT and in the historical control study, LH pretreatment was able to decrease the cancellation rate, to improve the in vitro performance, and to significantly increase the live birth rates. Conclusions. LH pretreatment improved oocyte quantity and quality in young repeated poor responders selected in accordance with the Bologna criteria.

Bio-equivalent doses of recombinent HCG and recombinent LH during ovarian stimulation result in similar oestradiol output

DEFF Research Database (Denmark)

Alsbjerg, Birgit; Elbaek, Helle Olesen; Laursen, Rita Jakubcionyte

2017-01-01

In nature, HCG is secreted by the implanting embryo from peri-implantation and onwards. In contrast, LH is mandatory for steroidogenesis and follicular development during the follicular phase, working in synergy with FSH. Moreover, LH is mandatory for the function of the corpus luteum. Although LH...... and HCG bind to the same receptor, significant molecular, structural and functional differences exist, inducing differences in bioactivity. This randomized controlled study compared the effect of recombinant FSH stimulation combined with daily either micro-dose recombinant HCG or recombinant LH...

Direct Observation of Energy Detrapping in LH1-RC Complex by Two-Dimensional Electronic Spectroscopy.

Science.gov (United States)

Ma, Fei; Yu, Long-Jiang; Hendrikx, Ruud; Wang-Otomo, Zheng-Yu; van Grondelle, Rienk

2017-01-18

The purple bacterial core light harvesting antenna-reaction center (LH1-RC) complex is the simplest system able to achieve the entire primary function of photosynthesis. During the past decade, a variety of photosynthetic proteins were studied by a powerful technique, two-dimensional electronic spectroscopy (2DES). However, little attention has been paid to LH1-RC, although its reversible uphill energy transfer, trapping, and backward detrapping processes, represent a crucial step in the early photosynthetic reaction dynamics. Thus, in this work, we employed 2DES to study two LH1-RC complexes of Thermochromatium (Tch.) tepidum. By direct observation of detrapping, the complex reversible process was clearly identified and an overall scheme of the excitation evolution in LH1-RC was obtained.

Neurotensin releases norepinephrine differentially from perfused hypothalamus of sated and fasted rat

International Nuclear Information System (INIS)

Lee, T.F.; Rezvani, A.H.; Hepler, J.R.; Myers, R.D.

1987-01-01

The central injection of neurotensin (NT) has been reported to attenuate the intake of food in the fasted animal. To determine whether endogenous norepinephrine (NE) is involved in the satiating effect of NT, the in vivo activity of NE in circumscribed sites in the hypothalamus of the unanesthetized rat was examined. Bilateral guide tubes for push-pull perfusion were implanted stereotaxically to rest permanently above one of several intended sites of perfusion, which included the paraventricular nucleus (PVN), ventromedial nucleus (VMN), and the lateral hypothalamic (LH) area. After endogenous stores of NE at a specific hypothalamic locus were radiolabeled by microinjection of 0.02-0.5 μCi of [ 3 H]NE, an artificial cerebrospinal fluid was perfused at the site at a rate of 20 μl/min over successive intervals of 5.0 min. When 0.05 or 0.1 μg/μl NT was added to the perfusate, the peptide served either to enhance or educe the local release of NE at 50% of the sites of perfusion. In these experiments, the circumscribed effect of NT on the characteristics of catecholamine efflux depended entirely on the state of hunger or satiety of the rat. That is, when NT was perfused in the fully satiated rat, NE release was augmented within the PVn or VMN; conversely, NE release was inhibited in the LH. in the animal fasted for 18-22 h, NT exerted an opposite effect on the activity of NE within the same anatomical loci in that the efflux of NE was enhanced in the LH but attenuated or unaffected in the PVN or VMN. Taken together, these observations provide experimental support for the view-point that NT could act as a neuromodulator of the activity of hypothalamic noradrenergic neurons that are thought to play a functional role in the regulation of food intake

Release of transgenic progranulin from a living hyaline cartilage graft model: An in vitro evaluation on anti-inflammation.

Science.gov (United States)

Lau, Ting Ting; Zhang, Feng; Tang, Wei; Wang, Dong-An

2016-12-01

Osteoarthritis (OA) is a prevalent condition that compromises and even jeopardizes the life quality of millions of people. Common symptoms in OA includes joint stiffness and soreness, and they are often associated with inflammations to various extend. Due to the avascular and aneural nature of articular hyaline cartilage, it has limited self-repair capabilities; especially under inflammatory conditions, damages inflicted on cartilage are often irreversible. Hence, treatment approaches focus on anti-inflammation or articular cartilage replacement. In this study, an engineered, dual-functional living hyaline cartilage graft (LhCG), capable of releasing transgenic anti-inflammatory cytokine-progranulin (PGRN) is developed and envisioned to simultaneously fulfil both requirements. The therapeutic functionality of PGRN releasing LhCG is evaluated by co-culturing the constructs with tumor necrosis factor-alpha (TNFα) secreting THP-1 cells to simulate the inflammatory condition in arthritis. Non-transgenic LhCG constructs and non-coculture sample groups were set up as controls. Gene expression and ECM composition changes across samples were assessed to understand the effects of PGRN as well as inflammatory environment on the cartilage graft. Collectively, the results in this study suggest that in situ release of transgenic recombinant PGRN protects LhCG from induced inflammation in vitro; contrastively, in the absence of PGRN, cartilage grafts are at risk of being degraded and mineralized under exposure to TNFα signaling. This shows that cartilage graft itself can be at risk of degradation or calcification when implanted in arthritic microenvironment. Hence, the inflammatory microenvironment has to be considered in cartilage replacement therapy to increase chances of successful joint mobility restoration. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2968-2977, 2016. © 2016 Wiley Periodicals, Inc.

Effects of polymer coated slow-release urea on ruminal fermentation and nutrient total tract digestion of beef steers

Directory of Open Access Journals (Sweden)

Rodrigo Gardinal

2016-02-01

Full Text Available ABSTRACT The objective of this study was to evaluate the effects of polymer coated slow-release urea (SRU in high-forage diets of beef steers on nutrient intake and digestibility, ruminal fermentation, microbial protein synthesis, and energy balance. Eight 24-mo-old rumen-fistulated castrated Nellore steers (average body weight = 418.0±40.0 kg were used in a replicated 4 × 4 Latin square design. Animals were randomly distributed to receive one of the following diets: no urea inclusion; 1.0% inclusion of feed grade urea in the diet (dry matter [DM] basis; 1.0% inclusion of slow-release urea 1 in the diet (DM basis; and 1.0% inclusion of slow-release urea 2 in the diet (DM basis. Slow-release urea 2 had a similar composition to that of slow-release urea 1 and differed in that it contained 2.95% sulfur. A high-forage diet was provided (75% of total DM and corn silage was used as the forage source. Diets with urea had increased crude protein (CP intake, and CP and total digestible nutrients total tract digestion. Urea sources increased ruminal concentrations of ammonia nitrogen and acetate, and decreased butyrate concentrations. The polymer coated urea did not alter ruminal fermentation when compared with feed grade urea. Diets did not affect the energy balance of steers. Feed grade urea presented greater microbial protein synthesis than polymer coated slow-release urea. The partial replacement of soybean meal by 1% slow-release urea in a diet with 75% forage does not improve ruminal fermentation and microbial protein synthesis, and shows similar results as feeding feed grade urea to beef steers.

Reciprocating Probe Measurements of L-H Transition in LHCD H-mode on EAST

DEFF Research Database (Denmark)

Peng, Liu; Guosheng, Xu; Huiqian, Wang

2013-01-01

that the power loss P loss was comparable during the L-H transition, by comparing the adjacent L-mode and H-mode discharge. The Dα emission, Te and ne decreased rapidly in the time scale of about 1 ms, and the radial electric field Er turned positive in this process near the last closed flux surface. Multiple L......-H-L transitions were observed during a single shot when the applied LHW power was marginal to the threshold. The floating potential (Vf) had negative spikes corresponding with the Dα signal, and Er oscillation evolved into several intermittent negative spikes just before the L-H transition. In some shots......, dithering was observed just before the L-H transition....

Comparison of platelet counts by sysmex XE 2100 and LH-750 with the international flow reference method in thrombocytopenic patients

Directory of Open Access Journals (Sweden)

Tina Dadu

2013-01-01

Full Text Available Background: There are several methods for counting platelets, of which the international flow reference method (IRM is considered to be the gold standard. We compared the platelet count given by this method to the count given by automated analyzers using other methods, such as optical fluorescence and impedance. Aims: The aim of this study is to compare the platelet counts obtained by Sysmex XE 2100 by Impedance (Sysmex-I, optical florescence (Sysmex-O and reported (Sysmex-R based on the switching algorithm and LH-750 by Impedance (LH-750 with the IRM in thrombocytopenic blood samples. To calculate the sensitivity, specificity, positive predictive value (PPV and negative predictive value (NPV of various technologies at the clinically relevant transfusion thresholds of 10 × 10 9 /l and 20 × 10 9 /l. Materials and Methods: A total of 118 blood samples with platelet count of <50 × 10 9 /l were selected for the study. Platelet counts of all samples were analyzed by all methods using the Sysmex analyzer, LH-750 and IRM in parallel within 6 h of collection. Statistical Analysis Used: Pearson correlation, bland Altman analysis, sensitivity and specificity, PPV and NPV. Results and Conclusions: Sysmex-R had the least Bias and 95% limits of agreement (95%LA range and thus correlated best with IRM values. LH-750 had a higher Bias compared to Sysmex-O and Sysmex-R, but a strikingly similar 95% LA ensures similar results in all three methods. In fact, in the oncology subset, it had the narrowest 95% LA, which made it the best performer in this subgroup. Of the three Sysmex results, Sysmex-I had the highest bias, widest 95% LA and highest potential risk of over transfusion. Hence, Sysmex-R and LH-750 were found to be reliable tools for estimation of platelet count in thrombocytopenic patients.

The electronically excited states of LH2 complexes from Rhodopseudomonas acidophila strain 10050 studied by time-resolved spectroscopy and dynamic Monte Carlo simulations. I. Isolated, non-interacting LH2 complexes.

Science.gov (United States)

Pflock, Tobias J; Oellerich, Silke; Southall, June; Cogdell, Richard J; Ullmann, G Matthias; Köhler, Jürgen

2011-07-21

We have employed time-resolved spectroscopy on the picosecond time scale in combination with dynamic Monte Carlo simulations to investigate the photophysical properties of light-harvesting 2 (LH2) complexes from the purple photosynthetic bacterium Rhodopseudomonas acidophila. The variations of the fluorescence transients were studied as a function of the excitation fluence, the repetition rate of the excitation and the sample preparation conditions. Here we present the results obtained on detergent solubilized LH2 complexes, i.e., avoiding intercomplex interactions, and show that a simple four-state model is sufficient to grasp the experimental observations quantitatively without the need for any free parameters. This approach allows us to obtain a quantitative measure for the singlet-triplet annihilation rate in isolated, noninteracting LH2 complexes.

Use of the gonadotrophin-releasing hormone antagonist azaline B to control the oestrous cycle in the koala (Phascolarctos cinereus).

Science.gov (United States)

Ballantyne, K; Anderson, S T; Pyne, M; Nicolson, V; Mucci, A; Lisle, A; Johnston, S D

2015-05-01

The present study examined the effectiveness of the gonadotrophin-releasing hormone (GnRH) antagonist azaline B to suppress plasma LH and 17β-oestradiol concentrations in koalas and its potential application for oestrous synchronisation. In Experiment 1, single subcutaneous injections of azaline B successfully blocked the LH response to exogenous mammalian (m) GnRH in a dose-dependent manner; specifically, 0 mg (n = 4) did not suppress the LH response, 1 mg azaline B (n = 6) suppressed the LH response for 24 h (P < 0.05), 3.3 mg azaline B (n = 8) suppressed the LH response significantly in all animals only for 3 h (P < 0.05), although in half the animals LH remained suppressed for up to 3 days, and 10 mg azaline B (n = 4) suppressed the LH response for 7 days (P < 0.05). In Experiment 2, daily 1 mg, s.c., injections of azaline B over a 10-day period during seasonal anoestrus (June-July; n = 6) suppressed (P < 0.01) the LH response to mGnRH consecutively over the 10-day treatment period and, 4 days after cessation of treatment, the LH response had not recovered. Experiment 3 was designed to test the efficacy of daily 1 mg, s.c., azaline B over 10 days to suppress plasma LH and 17β-oestradiol concentrations and ultimately synchronise timed return to oestrus during the breeding season. Although azaline B treatment did not suppress basal LH or 17β-oestradiol, oestrus was delayed in all treated females by 24.2 days, but with high variability (range 9-39 days). Overall, the present study demonstrates that the GnRH antagonist azaline B is able to inhibit the LH response in koalas to exogenous mGnRH and successfully delay the return to oestrus. However, although azaline B clearly disrupts folliculogenesis, it has not been able to effectively synchronise return to oestrus in the koala.

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

Science.gov (United States)

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

2006-01-01

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

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

Science.gov (United States)

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

1989-08-01

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

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

International Nuclear Information System (INIS)

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

1989-01-01

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

Role of exogenous estrogen in initiation of estrus and induction of an LH surge

Science.gov (United States)

Among cattle the LH surge that causes ovulation occurs shortly after the onset of a spontaneous estrus. In addition an injection of 100 'g of GnRH can induce an LH surge capable of inducing ovulation. We hypothesized that different preovulatory estradiol profiles would result in different ovulator...

Results of Semiscale Mod-2C small-break (5%) loss-of-coolant accident. Experiments S-LH-1 and S-LH-2

International Nuclear Information System (INIS)

Loomis, G.G.; Streit, J.E.

1985-11-01

Two experiments simulating small break (5%) loss-of-coolant accidents (5% SBLOCAs) were performed in the Semiscale Mod-2C facility. These experiments were identical except for downcomer-to-upper-head bypass flow (0.9% in Experiment S-LH-1 and 3.0% in Experiment S-LH-2) and were performed at high pressure and temperature [15.6 MPa (2262 psia) system pressure; 37 K (67 0 F) core differential temperature; 595 K(610 0 F) hot leg fluid temperature]. From the experimental results, the signature response and transient mass distribution are determined for a 5% SBLOCA. The core thermal-hydraulic response is characterized, including core void distribution maps, and the effect of core bypass flow on transient severity is assessed. Comparisons are made between postexperiment RELAP5 calculations and the experimental results, and the capability of RELAP5 to calculate the phenomena is assessed. 115 figs

Standardization of the radioimmunoassay of 17β-estradiol (E2) plasmatic and his application to the study of secretion of E2 in normal women, during the menstrual cycle and after the infusion of the gonadotropin (LH/FSH/RH) release factor

International Nuclear Information System (INIS)

Kiyan, Takeko Shimizu

1979-01-01

A radioimmunoassay method for measurement of plasma E 2 was standardized utilizing a highly specific antisera against E 2 [-6 (-0-carboxymethyl)-oxime] BSA without the need of previous chromatographic purification. The anti-E 2 serum was highly specific, showing high affinity with affinity constants: K 1 =1 .62x10 12 M -1 and K 2 = 2.94x10 11 M -1 , calculated by Scatchard plot. The standard curve sensitivity was 2 pico grams. The method was specific and accurate, showing an intra-assay precision with a mean C.V. of 2.9%, with the inter-assay evaluation showing a mean C.V. of 5.0%. This method was employed to evaluate E 2 secretion during the menstrual cycle in 6 normal females, as indicated below: Days: -14 to -10 (early follicular phase..64.68 pg/ml±12.14; - 9 to - 1(late follicular phase).122.39 pg/ml ±33,54; Peak day 281.28 pg/ml ±66 ,59; + 1 to + 7(early luteal phase) 127.47 pg/ml ±24.88; + 8 to +14 (late luteal phase) 87.57 pg/ml±37,56. The effect of the acute and prolonged infusion of LH/FSH-RH(synthetic hypothalamic LH and FSH releasing hormone) was evaluated in the follicular and luteal phase in some of the normal females. (author)

Human anti-luteinizing hormone-releasing hormone antibodies in patients treated with synthetic luteinizing hormone-releasing hormone

International Nuclear Information System (INIS)

Meakin, J.L.; Keogh, E.J.; Martin, C.E.

1985-01-01

One hundred sixty-three patients who were given synthetic LH-RH therapeutically underwent monitoring of serum IgG anti-LH-RH antibodies. Five of the patients showed specific binding to antibodies. Development of anti-LH-RH antibodies was not limited to those patients with a congenital deficiency of LH-RH. Urticarial responses occurred in four patients, only one of whom had IgG antibodies. Patients who had IgG antibodies or an urticarial response underwent monitoring of their serum IgE anti-LH-RH antibodies, but none had a positive binding response. The refractory state which has been reported in patients in whom similar antibodies to LH-RH develop was not invariably observed among these patients

Analysis of LH Launcher Arrays (Like the ITER One) Using the TOPLHA Code

International Nuclear Information System (INIS)

Maggiora, R.; Milanesio, D.; Vecchi, G.

2009-01-01

TOPLHA (Torino Polytechnic Lower Hybrid Antenna) code is an innovative tool for the 3D/1D simulation of Lower Hybrid (LH) antennas, i.e. accounting for realistic 3D waveguides geometry and for accurate 1D plasma models, and without restrictions on waveguide shape, including curvature. This tool provides a detailed performances prediction of any LH launcher, by computing the antenna scattering parameters, the current distribution, electric field maps and power spectra for any user-specified waveguide excitation. In addition, a fully parallelized and multi-cavity version of TOPLHA permits the analysis of large and complex waveguide arrays in a reasonable simulation time. A detailed analysis of the performances of the proposed ITER LH antenna geometry has been carried out, underlining the strong dependence of the antenna input parameters with respect to plasma conditions. A preliminary optimization of the antenna dimensions has also been accomplished. Electric current distribution on conductors, electric field distribution at the interface with plasma, and power spectra have been calculated as well. The analysis shows the strong capabilities of the TOPLHA code as a predictive tool and its usefulness to LH launcher arrays detailed design.

Effect of etorphine on the spontaneous and field stimulation-mediated release of norepinephrine and total tritium from perfused guinea pig hearts

International Nuclear Information System (INIS)

Anon.

1986-01-01

Isolated guinea pig hearts were prelabeled with 3 H-norepinephrine ( 3 H-NE) and perfused with modified Krebs-bicarbonate solution at 37 0 C. Spontaneous release of total 3 H and field stimulation-mediated (supramax. V., 1 Hz, 2 msec duration for a total of 60 pulses) overflow of NE and 3 H-NE were measured in the absence or presence of etorphine. Etorphine (0.1 - 100 μM) was added to the perfusion fluid 15 min. before the stimulation. To study the effect of etorphine on spontaneous release of total 3 H, etorphine was added cumulatively without stimulation. Etorphine (1.0 - 100 μM) caused a significant decrease in the stimulation-mediated overflow of NE and the inhibition was dose-related. The overflow of NE was 5.1 +/- 0.3 ng in the absence and 4.0 +/- 0.2 ng in the presence of etorphine (1.0 μM). Low concentrations of etorphine (0.1 - 1.0 μM) had no effect on the spontaneous release of total 3 H while 10 μM and 100 μM caused a 3 and 6-fold increase respectively. The results show that etorphine inhibited neuronal release of NE at a dose which had no effect on spontaneous release. It is suggested that opiate receptors might be involved in the prejunctional modulation of the release of NE in the guinea pig heart

Single-molecule spectroscopy reveals photosynthetic LH2 complexes switch between emissive states.

Science.gov (United States)

Schlau-Cohen, Gabriela S; Wang, Quan; Southall, June; Cogdell, Richard J; Moerner, W E

2013-07-02

Photosynthetic organisms flourish under low light intensities by converting photoenergy to chemical energy with near unity quantum efficiency and under high light intensities by safely dissipating excess photoenergy and deleterious photoproducts. The molecular mechanisms balancing these two functions remain incompletely described. One critical barrier to characterizing the mechanisms responsible for these processes is that they occur within proteins whose excited-state properties vary drastically among individual proteins and even within a single protein over time. In ensemble measurements, these excited-state properties appear only as the average value. To overcome this averaging, we investigate the purple bacterial antenna protein light harvesting complex 2 (LH2) from Rhodopseudomonas acidophila at the single-protein level. We use a room-temperature, single-molecule technique, the anti-Brownian electrokinetic trap, to study LH2 in a solution-phase (nonperturbative) environment. By performing simultaneous measurements of fluorescence intensity, lifetime, and spectra of single LH2 complexes, we identify three distinct states and observe transitions occurring among them on a timescale of seconds. Our results reveal that LH2 complexes undergo photoactivated switching to a quenched state, likely by a conformational change, and thermally revert to the ground state. This is a previously unobserved, reversible quenching pathway, and is one mechanism through which photosynthetic organisms can adapt to changes in light intensities.

Induction of ovarian activity and ovulation in an induced ovulator, the maned wolf (Chrysocyon brachyurus), using GnRH agonist and recombinant LH.

Science.gov (United States)

Johnson, Amy E M; Freeman, Elizabeth W; Colgin, Mark; McDonough, Caitlin; Songsasen, Nucharin

2014-07-01

Assisted reproductive techniques, such as ovarian manipulation and artificial insemination, are useful for enhancing genetic management of threatened wildlife maintained ex situ. In this study, we used noninvasive fecal hormone monitoring to investigate (1) the influence of pairing with a male on endocrine responses of female maned wolves (Chrysocyon brachyurus) to a GnRH agonist (deslorelin) and (2) the efficiency of recombinant LH (reLH) on ovulation induction in females housed alone. Deslorelin (2.1 mg Ovuplant) was given to females that were either paired with a male (n = 4) or housed alone (n = 7); the implant was removed 7 to 11 days postimplantation. Three of seven singleton females were injected with reLH (0.0375 mg) on the day of implant removal, whereas the remaining females (n = 4) did not receive the additional treatment. Fecal samples were collected 5 to 7 days/wk from all females starting 11 days prior to hormone insertion until at least 70 days post implant removal for a total of 11 hormone treatment cycles. Fecal estrogen and progestagen metabolites were extracted and analyzed by enzyme immunoassay. Evidence of ovulation, demonstrated by a surge of estrogen followed by a significant rise in progestagen, occurred in all paired females. Three of the four singleton females that did not receive reLH treatment exhibited no rise in progestagen after an estrogen surge. All singleton females treated with reLH exhibited a rise in fecal progestagen after injection, indicating ovulation. In conclusion, deslorelin is effective at inducing ovarian activity and ovulation in paired female maned wolves; however, exogenous reLH is needed to induce ovulation in females housed alone. The findings obtained from this study serve as a foundation for future application of artificial insemination to enhance genetic management of this threatened species ex situ. Published by Elsevier Inc.

The LH2 complexes are assembled in the cells of purple sulfur bacterium Ectothiorhodospira haloalkaliphila with inhibition of carotenoid biosynthesis.

Science.gov (United States)

Ashikhmin, Aleksandr; Makhneva, Zoya; Moskalenko, Andrey

2014-03-01

The effect of the inhibitor of carotenoid (Car) biosynthesis, diphenylamine (DPA), on the cells of the purple sulfur bacterium Ectothiorhodospira (Ect.) haloalkaliphila has been studied. There occurs an inhibition of the biosynthesis of colored Cars (≥99 %) at 71 μM DPA. Considering "empty" Car pockets (Moskalenko and Makhneva 2012) the content of Cars in the DPA-treated samples is first calculated more correctly. The total content of the colored Cars in the sample at 71 μM DPA does not exceed 1 % of the wild type. In the DPA-treated cells (membranes) a complete set of pigment-protein complexes is retained. The LH2 complex at 71 μM DPA is isolated, which is identical to the LH2 complex of the wild type in near IR absorption spectra. This suggests that the principles for assembling this LH2 complex in vivo in the absence of colored Cars remain the same. These results are in full agreement with the data obtained earlier for Allochromatium (Alc.) minutissimum (Moskalenko and Makhneva 2012). They are as follows: (1) DPA almost entirely inhibits the biosynthesis of the colored Cars in Ect. haloalkaliphila cells. (2) In the DPA-treated samples non-colored Cars are detected at 53.25 μM DPA (as traces) and at 71 μM DPA. (3) DPA may affect both phytoene synthase (at ≤71 μM DPA) and phytoene desaturase (at ≥53.25 μM DPA). (4) The assembly of LH2 complex does occur without any colored Cars.

LO2/LH2 propulsion for outer planet orbiter spacecraft

Science.gov (United States)

Garrison, P. W.; Sigurdson, K. B.

1983-01-01

Galileo class orbiter missions (750-1500 kg) to the outer planets require a large postinjection delta-V for improved propulsion performance. The present investigation shows that a pump-fed low thrust LO2/LH2 propulsion system can provide a significantly larger net on-orbit mass for a given delta-V than a state-of-the-art earth storable, N2O4/monomethylhydrazine pressure-fed propulsion system. A description is given of a conceptual design for a LO2/LH2 pump-fed propulsion system developed for a Galileo class mission to the outer planets. Attention is given to spacecraft configuration, details regarding the propulsion system, the thermal control of the cryogenic propellants, and aspects of mission performance.

Sequencing and generation of an infectious clone of the pathogenic goose parvovirus strain LH.

Science.gov (United States)

Wang, Jianye; Duan, Jinkun; Zhu, Liqian; Jiang, Zhiwei; Zhu, Guoqiang

2015-03-01

In this study, the complete genome of the virulent strain LH of goose parvovirus (GPV) was sequenced and cloned into the pBluescript II (SK) plasmid vector. Sequence alignments of the inverted terminal repeats (ITR) of GPV strains revealed a common 14-nt-pair deletion in the stem of the palindromic structure in the LH strain and three other strains isolated after 1982 when compared to three GPV strains isolated earlier than that time. Transfection of 11-day-old embryonated goose eggs with the plasmid pLH, which contains the entire genome of strain LH, resulted in successful rescue of the infectious virus. Death of embryos after transfection via the chorioallantoic membrane infiltration route occurred earlier than when transfection was done via the allantoic cavity inoculation route. The rescued virus exhibited virulence similar to that of its parental virus, as evaluated by the mortality rate in goslings. Generation of the pathogenic infectious clone provides us with a powerful tool to elucidate the molecular pathogenesis of GPV in the future.

Evaluation of biological activities of new LH-RH antagonists (T-series) in male and female rats.

Science.gov (United States)

Pinski, J; Yano, T; Janaky, T; Nagy, A; Juhasz, A; Bokser, L; Groot, K; Schally, A V

1993-01-01

A series of new highly potent LH-RH antagonists (T-series) has been synthesized in our laboratory. Among these analogs, antagonists [Ac-D-Nal(2), D-Phe(4Cl)2, D-Pal(3)3, D-Lys(A2pr(Car)2)6, D-Ala10]LH-RH (T-140); [Ac-D-Nal(2)1, D-Phe(4Cl)2, D-Pal(3)3, D-Lys(A2pr(Ac)2)6, D-Ala10]LH-RH (T-148); [Ac-D-Nal(2)1, D-Phe(4Cl)2, D-Pal(3)3, D-Lys(A2pr(For)2)6, D-Ala10]LH-RH (T-151) and [Ac-D-Nal(2)1, D-Phe(4Cl)2, D-Pal(3)3, D-Lys(A2bu(For)2)6, D-Ala10]LH-RH (T-159) were the most powerful. Antagonists T-140, T-148 and T-151 produced a complete blockade of ovulation in normal cycling rats at a dose of 1.5 micrograms/rat and antagonist T-159 at a dose of only 0.75 micrograms/rat. The inhibitory effects of compounds T-148, T-151 and T-159 on gonadotropin and sex steroid secretion were investigated in male and female rats. To determine their effect on LH levels in castrated male and ovariectomized female rats, T-148, T-151 and T-159 were injected subcutaneously in doses of 0.625 and 2.5 micrograms/rat. Blood samples were taken at different intervals for 48 h. All three compounds at either dose caused a significant (P < 0.01) decrease in LH levels for more than 6 h. Significant (P < 0.01) inhibition of LH lasted for more than 24 h following a dose of 2.5 micrograms sc of all 3 antagonists in both male and female rats. Serum FSH levels were also suppressed significantly for more than 48 h in castrated male rats by all three antagonists at a dose of 5 micrograms/rat sc.(ABSTRACT TRUNCATED AT 250 WORDS)

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

Science.gov (United States)

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

2017-10-26

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

Environment-assisted Quantum Critical Effect for Excitation Energy Transfer in a LH2-type Trimer

Science.gov (United States)

Xu, Lan; Xu, Bo

2015-10-01

In this article, we are investigating excitation energy transfer (EET) in a basic unit cell of light-harvesting complex II (LH2), named a LH2-type trimer. Calculation of energy transfer efficiency (ETE) in the framework of non-Markovian environment is also implemented. With these achievements, we theoretically predict the environment-assisted quantum critical effect, where ETE exhibits a sudden change at the critical point of quantum phase transition (QPT) for the LH2-type trimer. It is found that highly efficient EET with nearly unit efficiency may occur in the vicinity of the critical point of QPT.

Structural model and excitonic properties of the dimeric RC-LH1-PufX complex from Rhodobacter sphaeroides

International Nuclear Information System (INIS)

Sener, Melih; Hsin, Jen; Trabuco, Leonardo G.; Villa, Elizabeth; Qian, Pu; Hunter, C. Neil; Schulten, Klaus

2009-01-01

The light-harvesting apparatus of the purple bacterial photosynthetic unit consists of a pool of peripheral light-harvesting complexes that transfer excitation energy to a reaction center (RC) via the surrounding pigment-protein complex LH1. Recent electron microscopy and atomic force microscopy studies have revealed that RC-LH1 units of Rhodobacter (Rba.) sphaeroides form membrane-bending dimeric complexes together with the polypeptide PufX. We present a structural model for these RC-LH1-PufX dimeric complexes constructed using the molecular dynamics flexible fitting method based on an EM density map. The arrangement of the LH1 BChls displays a distortion near the proposed location of the PufX polypeptide. The resulting atomic model for BChl arrays is used to compute the excitonic properties of the dimeric RC-LH1 complex. A comparison is presented between the structural and excitonic features of the S-shaped dimeric BChl array of Rba. sphaeroides and the circular BChl arrangement found in other purple bacteria

Neuroanatomical organization of gonadotropin-releasing hormone neurons during the oestrus cycle in the ewe

Science.gov (United States)

Batailler, Martine; Caraty, Alain; Malpaux, Benoît; Tillet, Yves

2004-01-01

Background During the preovulatory surge of gonadotropin-releasing hormone (GnRH), a very large amount of the peptide is released in the hypothalamo-hypophyseal portal blood for 24-36H00. To study whether this release is linked to a modification of the morphological organization of the GnRH-containing neurons, i.e. morphological plasticity, we conducted experiments in intact ewes at 4 different times of the oestrous cycle (before the expected LH surge, during the LH surge, and on day 8 and day 15 of the subsequent luteal phase). The cycle stage was verified by determination of progesterone and LH concentrations in the peripheral blood samples collected prior to euthanasia. Results The distribution of GnRH-containing neurons throughout the preoptic area around the vascular organ of the lamina terminalis was studied following visualisation using immunohistochemistry. No difference was observed in the staining intensity for GnRH between the different groups. Clusters of GnRH-containing neurons (defined as 2 or more neurons being observed in close contact) were more numerous during the late follicular phase (43 ± 7) than during the luteal phase (25 ± 6), and the percentage of clusters was higher during the beginning of the follicular phase than during the luteal phase. There was no difference in the number of labelled neurons in each group. Conclusions These results indicate that the morphological organization of the GnRH-containing neurons in ewes is modified during the follicular phase. This transitory re-organization may contribute to the putative synchronization of these neurons during the surge. The molecular signal inducing this plasticity has not yet been identified, but oestradiol might play an important role, since in sheep it is the only signal which initiates the GnRH preovulatory surge. PMID:15555074

Neuroanatomical organization of gonadotropin-releasing hormone neurons during the oestrus cycle in the ewe

Directory of Open Access Journals (Sweden)

Malpaux Benoît

2004-11-01

Full Text Available Abstract Background During the preovulatory surge of gonadotropin-releasing hormone (GnRH, a very large amount of the peptide is released in the hypothalamo-hypophyseal portal blood for 24-36H00. To study whether this release is linked to a modification of the morphological organization of the GnRH-containing neurons, i.e. morphological plasticity, we conducted experiments in intact ewes at 4 different times of the oestrous cycle (before the expected LH surge, during the LH surge, and on day 8 and day 15 of the subsequent luteal phase. The cycle stage was verified by determination of progesterone and LH concentrations in the peripheral blood samples collected prior to euthanasia. Results The distribution of GnRH-containing neurons throughout the preoptic area around the vascular organ of the lamina terminalis was studied following visualisation using immunohistochemistry. No difference was observed in the staining intensity for GnRH between the different groups. Clusters of GnRH-containing neurons (defined as 2 or more neurons being observed in close contact were more numerous during the late follicular phase (43 ± 7 than during the luteal phase (25 ± 6, and the percentage of clusters was higher during the beginning of the follicular phase than during the luteal phase. There was no difference in the number of labelled neurons in each group. Conclusions These results indicate that the morphological organization of the GnRH-containing neurons in ewes is modified during the follicular phase. This transitory re-organization may contribute to the putative synchronization of these neurons during the surge. The molecular signal inducing this plasticity has not yet been identified, but oestradiol might play an important role, since in sheep it is the only signal which initiates the GnRH preovulatory surge.

Preovulatory progesterone concentration associates significantly to follicle number and LH concentration but not to pregnancy rate

DEFF Research Database (Denmark)

Yding Andersen, Claus; Bungum, Leif; Nyboe Andersen, Anders

2011-01-01

Using data from a large prospective randomized controlled trial that evaluated the effect of recombinant LH (rLH)co-administration for ovarian stimulation, the present study assessed whether progesterone concentration on the day of human chorionic gonadotrophin (HCG) administration was associated...... with or without rLH administration from day 6 of stimulation. There was no significant association between the late-follicular-phase progesterone concentration and the clinical pregnancy rate. However, progesterone concentration was strongly associated with the number of follicles and retrieved oocytes. Late...

Intercellular communications within the rat anterior pituitary. XVI: postnatal changes of distribution of S-100 protein positive cells, connexin 43 and LH-RH positive sites in the pars tuberalis of the rat pituitary gland. An immunohistochemical and electron microscopic study.

Science.gov (United States)

Wada, Ikuo; Sakuma, Eisuke; Shirasawa, Nobuyuki; Wakabayashi, Kenjiro; Otsuka, Takanobu; Hattori, Kazuki; Yashiro, Takashi; Herbert, Damon C; Soji, Tsuyoshi

2014-02-01

The architecture of luteinizing hormone-releasing hormone (LH-RH) nerve ends and the S-100 protein containing folliculo-stellate cells forming gap junctions in the pars tuberalis is basically important in understanding the regulation of the hormone producing mechanism of anterior pituitary glands. In this study, intact male rats 5-60 days old were prepared for immunohistochemistry and electron microscopy. From immunostained sections, the S-100 containing cells in pars tuberalis were first detected on day 30 and increased in number to day 60; this was parallel to the immunohistochemical staining of gap junction protein, connexin 43. LH-RH positive sites were clearly observed on just behind the optic chiasm and on the root of pituitary stalk on day 30. On day 60, the width of layer increased, while follicles and gap junctions were frequently observed between agranular cells in 10 or more layers of pars tuberalis. In the present study, we investigated the sexual maturation of the anterior pituitary glands through the postnatal development of S-100 positive cells, connexin 43 and LH-RH nerves. It is suggested that the folliculo-stellate cell system including the LH-RH neurons in the pars tuberalis participates in the control of LH secretion along with the portal vein system. Copyright © 2013 Elsevier Ltd. All rights reserved.

Cost Beneftt Analysts of LH2 PadB

Science.gov (United States)

Mott, Brittany

2013-01-01

This analysis is used to evaluate, from a cost and benefit perspective, potential outcomes when replacing the pressurization switches and the pressurization system to meet the needs of the LH2 storage system at Pad B. This also includes alternatives, tangible and intangible benefits, and the results of the analysis.

Use of purified FSH and LH for embryo production, cryopreservation by conventional freezing or vitrification and transfer of embryos in dairy ewes

Directory of Open Access Journals (Sweden)

Giovanni Martemucci

2010-01-01

Full Text Available Three experiments were carried out with the aim of evaluating the efficiency of techniques of in vivo production, storageand transfer of embryos in dairy sheep. Experiment I - For embryo production, thirty-one ewes were synchronized withFGA (vaginal sponges, 40 mg, 9 d and PGF2α (ICI; 50 μg, 7th d, and subdivided into three groups corresponding to thefollowing superovulatory treatments over 3 days with purified gonadotrophic preparations: A control, FSH/LH ratio = 1(250 IU p-FSH : 250 UI p-LH; B FSH/LH ratio = 2 (250 IU p-FSH : 125 IU p-LH and daily FSH/LH ratio of 3.4 – 1.7 –0.8 in the 3 days of treatment, respectively; C FSH/LH ratio = 2 (250 IU p-FSH : 125 IU p-LH and daily FSH/LH ratioof 5.0 – 1.0 – 0.3. On the 7th day after oestrus and mating, ovarian response and embryo production were evaluated.Experiment II – Three freezing methods were evaluated based upon post-thaw embryo quality: CF conventional slowfreezing by 1.5 M ethylene glycol (EG; V-1 one-step vitrification based on exposure of the embryos to one solution (EG7.15 M + ficoll 2.5 mM; V-3 vitrification in three steps, corresponding to three solutions at increasing concentration ofglycerol (GLY and EG (GLY 1.4 M; GLY 3.4 M + EG 1.4 M; GLY 4.6 M + EG 3.4 M. V-1 and V-3 frozen embryos weredirectly plunged in liquid nitrogen. At thawing, embryo viability was evaluated on the basis of morphological features.Experiment III – For embryo transfer, a total of 26 recipient ewes were synchronized with donors. On the 7th d fromoestrus, 11 recipient ewes received fresh embryos (Group FE – control and 15 recipients received vitrified-thawedembryos (Group VTE. Each recipient received 2 embryos. Superovulatory treatment B significantly advanced the onsetof oestrus compared to the control (27.3 vs 34.7 h; P10.8. Transferable embryos in Group B (7.2 resulted similar to Group A (5.3 and significantly (Pcompared to Group C (3.2. V3-method resulted in the highest (PCF- and V1-methods

Lab-on-fiber optofluidic platform for in situ monitoring of drug release from therapeutic eluting polyelectrolyte multilayers

Czech Academy of Sciences Publication Activity Database

Tian, F.; Min, J.; Kaňka, Jiří; Li, X.; Hammond, P. T.; Du, H.

2015-01-01

Roč. 23, č. 15 (2015), s. 20132-20142 ISSN 1094-4087 R&D Projects: GA MŠk(CZ) LH11038 Institutional support: RVO:67985882 Keywords : long-period grating * drug release * thin film Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 3.148, year: 2015

Testosterone stimulates progesterone production and STAR, P450 cholesterol side-chain cleavage and LH receptor mRNAs expression in hen (Gallus domesticus) granulosa cells.

Science.gov (United States)

Rangel, P L; Rodríguez, A; Rojas, S; Sharp, P J; Gutierrez, C G

2009-12-01

The chicken ovary is organized into a hierarchy of yellow yolky follicles that ovulate on successive days. Active or passive immunization of laying hens against testosterone blocks ovulation without affecting follicle development. Testosterone may play a role in pre-ovulatory follicle maturation by stimulating granulosa progesterone production. We assessed whether this stimulus is dose-related and depends on the maturity of the donor follicle, and if it does so by stimulating granulosa cell STAR, P450 cholesterol side-chain cleavage (P450scc), and LH receptor (LHCGR) mRNAs expression. Progesterone production by granulosa cells from F1, F3, and F4 follicles, cultured for 3 h without testosterone was greater in cells collected 11-14 h than 1-4 h after ovulation. These differences in progesterone production were less pronounced after granulosa cells had been cultured for 24 h. Culture of granulosa cells for 3 or 24 h with testosterone (1-100 ng/ml) stimulated progesterone production in cells collected from F4, F3, or F1 follicles 1-4, or 11-14 h after ovulation. Testosterone (0-4000 ng/ml) alone or in combination with LH (0-100 ng/ml) increased progesterone production by F1 granulosa cells, collected 1-4 and 11-14 h after ovulation and cultured for 3 h. Finally, testosterone (10 or 100 ng/ml) increased STAR, P450scc, and LHCGR mRNAs, when added to 3 h cultures of F1 granulosa cells. In conclusion, testosterone stimulates granulosa cell progesterone production in hen pre-ovulatory hierarchical follicles irrespective of maturational state, acting alone or additively with LH. We propose that testosterone promotes granulosa cell maturation to facilitate the pre-ovulatory release of LH.

A replacement LH2 recirculation line before installation in Discovery

Science.gov (United States)

1999-01-01

A spare four-inch diameter LH2 recirculation line (shown in photo) will be used to replace a damaged LH2 line in the orbiter Discovery. The line recirculates hydrogen from the Shuttle main engines back to the external tank during prelaunch engine conditioning. Workers noted a dent in the line during routine aft compartment inspections Tuesday, Dec. 7. The dent measures 12 inches long and about =-inch deep. Managers expect the replacement work to take about 3 days, followed by system retests and final aft compartment close-outs. Preliminary assessments reflect a launch date of Space Shuttle Discovery on mission STS-103 no earlier than Dec. 16. STS-103 is the third servicing mission for the Hubble Space Telescope.

The electronically excited states of LH2 complexes from Rhodopseudomonas acidophila strain 10050 studied by time-resolved spectroscopy and dynamic Monte Carlo simulations. II. Homo-arrays of LH2 complexes reconstituted into phospholipid model membranes.

Science.gov (United States)

Pflock, Tobias J; Oellerich, Silke; Krapf, Lisa; Southall, June; Cogdell, Richard J; Ullmann, G Matthias; Köhler, Jürgen

2011-07-21

We performed time-resolved spectroscopy on homoarrays of LH2 complexes from the photosynthetic purple bacterium Rhodopseudomonas acidophila. Variations of the fluorescence transients were monitored as a function of the excitation fluence and the repetition rate of the excitation. These parameters are directly related to the excitation density within the array and to the number of LH2 complexes that still carry a triplet state prior to the next excitation. Comparison of the experimental observations with results from dynamic Monte Carlo simulations for a model cluster of LH2 complexes yields qualitative agreement without the need for any free parameter and reveals the mutual relationship between energy transfer and annihilation processes.

Protein-induced geometric constraints and charge transfer in bacteriochlorophyll-histidine complexes in LH2.

Science.gov (United States)

Wawrzyniak, Piotr K; Alia, A; Schaap, Roland G; Heemskerk, Mattijs M; de Groot, Huub J M; Buda, Francesco

2008-12-14

Bacteriochlorophyll-histidine complexes are ubiquitous in nature and are essential structural motifs supporting the conversion of solar energy into chemically useful compounds in a wide range of photosynthesis processes. A systematic density functional theory study of the NMR chemical shifts for histidine and for bacteriochlorophyll-a-histidine complexes in the light-harvesting complex II (LH2) is performed using the BLYP functional in combination with the 6-311++G(d,p) basis set. The computed chemical shift patterns are consistent with available experimental data for positive and neutral(tau) (N(tau) protonated) crystalline histidines. The results for the bacteriochlorophyll-a-histidine complexes in LH2 provide evidence that the protein environment is stabilizing the histidine close to the Mg ion, thereby inducing a large charge transfer of approximately 0.5 electronic equivalent. Due to this protein-induced geometric constraint, the Mg-coordinated histidine in LH2 appears to be in a frustrated state very different from the formal neutral(pi) (N(pi) protonated) form. This finding could be important for the understanding of basic functional mechanisms involved in tuning the electronic properties and exciton coupling in LH2.

L-H transition in the mega-Amp spherical tokamak

DEFF Research Database (Denmark)

Akers, R.J.; Counsell, G.F.; Sykes, A.

2002-01-01

H-mode plasmas have been achieved on the MAST spherical tokamak at input power considerably higher than predicted by conventional threshold scalings. Following L-H transition, a clear improvement in energy confinement is obtained, exceeding recent international scalings even at densities approach...

Análise de eventos hidrológicos extremos, usando-se a distribuição GEV e momentos LH Analysis of extreme hydrological events using GEV distribution and LH moments

Directory of Open Access Journals (Sweden)

Manoel M. F. de Queiroz

2006-06-01

Full Text Available A distribuição de probabilidade generalizada de valores extremos (GEV, tem facilitado muitas aplicações em hidrologia, utilizada na modelação de eventos extremos naturais. Estudos sobre o assunto mostram que estimadores de máxima verossimilhança dos parâmetros da GEV são instáveis em pequenas amostras, podendo fornecer valores absurdos do parâmetro de forma, quando então são recomendados estimadores de momentos LH, baseados na combinação linear de estatísticas de altas ordens, introduzidas para caracterizar a parte mais alta da distribuição e os valores extremos dos dados; contudo, não se dispõe de programas computacionais para PC, que modelem eventos extremos via momentos LH. Objetivou-se, com este trabalho, apresentar a modelação de eventos hidrológicos extremos através da distribuição GEV, utilizando-se momentos LH para estimar seus parâmetros e o teste estatístico proposto por Wang (1998 para verificação da qualidade dos ajustes desenvolvidos no ambiente Matlab. Como resultados, são apresentados as estimativas dos parâmetros da GEV, os valores das taxas de momentos LH: coeficientes de variação, assimetria e curtose, e os valores do teste de qualidade de ajuste, em aplicações com dados de vazão de rios do Paraná.The generalized extreme-value (GEV distribution has facilitated many applications in hydrology, used to model a wide variety of natural extreme events. Previous studies show that small-sample maximum-likelihood estimators parameters are unstable and demonstrates that absurd values of the GEV shape parameter can be generated. It is recommended that LH moments estimators, based on linear combinations of higher-order statistics, should be introduced for characterizing the upper part of distributions and larger events in data. However, there have been no computer packages for PC that model extreme events by LH moments. The objective of this paper was to present the modeling of hydrological extreme

Function of membrane protein in silica nanopores: incorporation of photosynthetic light-harvesting protein LH2 into FSM.

Science.gov (United States)

Oda, Ippei; Hirata, Kotaro; Watanabe, Syoko; Shibata, Yutaka; Kajino, Tsutomu; Fukushima, Yoshiaki; Iwai, Satoshi; Itoh, Shigeru

2006-01-26

A high amount of functional membrane protein complex was introduced into a folded-sheet silica mesoporous material (FSM) that has nanometer-size pores of honeycomb-like hexagonal cylindrical structure inside. The photosynthetic light-harvesting complex LH2, which is a typical membrane protein, has a cylindrical structure of 7.3 nm diameter and contains 27 bacteriochlorophyll a and nine carotenoid molecules. The complex captures light energy in the anoxygenic thermophilic purple photosynthetic bacterium Thermochromatium tepidum. The amount of LH2 adsorbed to FSM was determined optically and by the adsorption isotherms of N2. The FSM compounds with internal pore diameters of 7.9 and 2.7 nm adsorbed LH2 at 1.11 and 0.24 mg/mg FSM, respectively, suggesting the high specific affinity of LH2 to the interior of the hydrophobic nanopores with a diameter of 7.9 nm. The LH2 adsorbed to FSM showed almost intact absorption bands of bacteriochlorophylls, and was fully active in the capture and transfer of excitation energy. The LH2 complex inside the FSM showed increased heat stability of the exciton-type absorption band of bacteriochlorophylls (B850), suggesting higher circular symmetry. The environment inside the hydrophobic silica nanopores can be a new matrix for the membrane proteins to reveal their functions. The silica-membrane protein adduct will be useful for the construction of new probes and reaction systems.

Functional characteristics of spirilloxanthin and keto-bearing Analogues in light-harvesting LH2 complexes from Rhodobacter sphaeroides with a genetically modified carotenoid synthesis pathway.

Science.gov (United States)

Niedzwiedzki, Dariusz M; Dilbeck, Preston L; Tang, Qun; Mothersole, David J; Martin, Elizabeth C; Bocian, David F; Holten, Dewey; Hunter, C Neil

2015-01-01

Light-harvesting 2 (LH2) complexes from a genetically modified strain of the purple photosynthetic bacterium Rhodobacter (Rba.) sphaeroides were studied using static and ultrafast optical methods and resonance Raman spectroscopy. Carotenoid synthesis in the Rba. sphaeroides strain was engineered to redirect carotenoid production away from spheroidene into the spirilloxanthin synthesis pathway. The strain assembles LH2 antennas with substantial amounts of spirilloxanthin (total double-bond conjugation length N=13) if grown anaerobically and of keto-bearing long-chain analogs [2-ketoanhydrorhodovibrin (N=13), 2-ketospirilloxanthin (N=14) and 2,2'-diketospirilloxanthin (N=15)] if grown semi-aerobically (with ratios that depend on growth conditions). We present the photophysical, electronic, and vibrational properties of these carotenoids, both isolated in organic media and assembled within LH2 complexes. Measurements of excited-state energy transfer to the array of excitonically coupled bacteriochlorophyll a molecules (B850) show that the mean lifetime of the first singlet excited state (S1) of the long-chain (N≥13) carotenoids does not change appreciably between organic media and the protein environment. In each case, the S1 state appears to lie lower in energy than that of B850. The energy-transfer yield is ~0.4 in LH2 (from the strain grown aerobically or semi-aerobically), which is less than half that achieved for LH2 that contains short-chain (N≤11) analogues. Collectively, the results suggest that the S1 excited state of the long-chain (N≥13) carotenoids participates little if at all in carotenoid-to-BChl a energy transfer, which occurs predominantly via the carotenoid S2 excited state in these antennas. Copyright © 2015 Elsevier B.V. All rights reserved.

125I-luteinizing hormone (LH) binding to soluble receptors from the primate (Macaca mulatta) corpus luteum: effects of ethanol exposure

International Nuclear Information System (INIS)

Danforth, D.R.; Stouffer, R.L.

1988-01-01

In the current study, we compared the effects of ethanol on gonadotropin receptors solubilized from macaque luteal membranes to those on receptors associated with the lipid bilayer. Treatment with 1% Triton X-100 for 30 min at 4C, followed by precipitation with polyethylene glycol, resulted in recovery of 50% more binding sites for 125 I-human luteinizing hormone (hLH) than were available in particulate preparations. However, the soluble receptors displayed a 3-fold lower affinity for 125 I-hLH. Conditions which enhanced LH binding to particulates, i.e., 1-8% ethanol at 25C, decreased specific 125 I-hLH binding to soluble receptors. Steady-state LH binding to soluble receptors during incubation at 4C was half of that observed at 25C. The presence of 8% ethanol at 4C restored LH binding to levels observed in the absence of ethanol at 25C. Thus, LH binding sites in the primate corpus luteum can be effectively solubilized with Triton X-100. The different binding characteristics of particulate and soluble receptors, including the response to ethanol exposure, suggest that the lipid environment in the luteal membrane modulates the availability and affinity of gonadotropin receptors

Fast change in core transport after L-H transition

International Nuclear Information System (INIS)

Kadomtsev, B.B.; Itoh, K.; Itoh, S.

1995-03-01

The transport in the core tokamak plasma is known to change very rapidly after the L-H transition in the edge plasma. A qualitative discussion is given for this fast transmission of the transport change. A picture based on the successive bifurcations is presented. (author)

Plasma biasing by fast particles generation in front of CASTOR and TORE SUPRA tokamak LH grills

International Nuclear Information System (INIS)

Petrzilka, V.; Jakubka, K.; Klima, R.

1999-01-01

Computation results are presented concerning the electron acceleration by the LH wave alone, which are necessary for determining the value of the effective ponderomotive potential W. One set of selected parameters is representative for large tokamaks like Tore Supra and JET; the other set is representative for the small CASTOR tokamak. To estimate the value of W, the test-particle model was used for describing the electron acceleration. Then, by using the two-fluid model, profiles of U and Ε z are presented. Further, by using the corresponding value of W in the Particle-in-Cell model for the simulations of the plasma vortex in front of the LH grill, the effects are explored of the electrostatic fields Ε r , Ε θ and Ε z , on the following processes: 1. particle acceleration in front of LH grills by rf waves - it is demonstrated that in addition to electron acceleration, the charge-separation electrostatic field Ε z also accelerates ions to energies of several keV; 2. effects of plasma sources on the flow of particles from the narrow layer in front of the LH grill mouth - here it is shown that ionization alone is not sufficient for creating the experimentally observed plasma densities in front of LH grills

Full-wave Simulations of LH Wave Propagation in Toroidal Plasma with non-Maxwellian Electron Distributions

International Nuclear Information System (INIS)

Valeo, E.J.; Phillips, C.K.; Bonoli, P.T.; Wright, J.C.; Brambilla, M.

2007-01-01

The generation of energetic tails in the electron distribution function is intrinsic to lower-hybrid (LH) heating and current drive in weakly collisional magnetically confined plasma. The effects of these deformations on the RF deposition profile have previously been examined within the ray approximation. Recently, the calculation of full-wave propagation of LH waves in a thermal plasma has been accomplished using an adaptation of the TORIC code. Here, initial results are presented from TORIC simulations of LH propagation in a toroidal plasma with non-thermal electrons. The required efficient computation of the hot plasma dielectric tensor is accomplished using a technique previously demonstrated in full-wave simulations of ICRF propagation in plasma with non-thermal ions

Ovarian response and pregnancy outcome related to mid-follicular LH levels in women undergoing assisted reproduction with GnRH agonist down-regulation and recombinant FSH stimulation

DEFF Research Database (Denmark)

Humaidan, P; Bungum, L; Bungum, M

2002-01-01

stimulation with recombinant FSH. METHODS: Blood samples were prospectively collected from a total of 207 normal women undergoing assisted reproduction and analysed retrospectively. Based on LH levels on stimulation day 8 patients were divided into four groups: 1.51 IU/l. RESULTS...

Temporal concentrations of cortisol and LH in virgin ewes acutely exposed to rams during the transition into the breeding season.

Science.gov (United States)

McCosh, R B; Berry, E M; Wehrman, M E; Redden, R R; Hallford, D M; Berardinelli, J G

2015-03-01

The objectives of this study were to determine if exposing seasonally anovular ewes to rams would alter patterns of cortisol concentrations, and if these changes are associated with changes in characteristics of LH concentrations. Seasonally anestrous ewes were assigned to be exposed to rams (RE; n=11) or wethers (NE; n=12). Blood samples were collected at 15-min intervals beginning 120 min before introduction of males (time=0 min), and continued for 360 min after male exposure. Characteristics of cortisol and LH concentrations included: mean and baseline concentrations, pulse amplitude, duration, frequency, and time to first pulse. Mean and baseline cortisol concentrations, and cortisol pulse amplitude, frequency, and time to first pulse after male exposure did not differ between RE and NE ewes. Cortisol pulse duration was longer (Pewes than in NE ewes. Mean LH and LH pulse amplitude, duration, and time to first pulse after male exposure did not differ between RE and NE ewes. Baseline LH concentrations and LH pulse frequency were greater (Pewes. In RE ewes, but not NE ewes, LH pulse frequency tended to increase (P=0.06) as pulse frequency of cortisol decreased. In conclusion, exposing ewes to mature rams during the transition into the breeding season increased LH pulse frequency which hastened ovulatory activity. However, the results do not support the hypothesis that changes in cortisol concentrations plays a significant role in the 'ram effect'. Copyright © 2015 Elsevier B.V. All rights reserved.

LOX/LH2 vane pump for auxiliary propulsion systems

Science.gov (United States)

Hemminger, J. A.; Ulbricht, T. E.

1985-01-01

Positive displacement pumps offer potential efficiency advantages over centrifugal pumps for future low thrust space missions. Low flow rate applications, such as space station auxiliary propulsion or dedicated low thrust orbiter transfer vehicles, are typical of missions where low flow and high head rise challenge centrifugal pumps. The positive displacement vane pump for pumping of LOX and LH2 is investigated. This effort has included: (1) a testing program in which pump performance was investigated for differing pump clearances and for differing pump materials while pumping LN2, LOX, and LH2; and (2) an analysis effort, in which a comprehensive pump performance analysis computer code was developed and exercised. An overview of the theoretical framework of the performance analysis computer code is presented, along with a summary of analysis results. Experimental results are presented for pump operating in liquid nitrogen. Included are data on the effects on pump performance of pump clearance, speed, and pressure rise. Pump suction performance is also presented.

Regional and temporal differences in gene expression of LH(BETA)T(AG) retinoblastoma tumors.

Science.gov (United States)

Houston, Samuel K; Pina, Yolanda; Clarke, Jennifer; Koru-Sengul, Tulay; Scott, William K; Nathanson, Lubov; Schefler, Amy C; Murray, Timothy G

2011-07-23

The purpose of this study was to evaluate by microarray the hypothesis that LH(BETA)T(AG) retinoblastoma tumors exhibit regional and temporal variations in gene expression. LH(BETA)T(AG) mice aged 12, 16, and 20 weeks were euthanatized (n = 9). Specimens were taken from five tumor areas (apex, anterior lateral, center, base, and posterior lateral). Samples were hybridized to gene microarrays. The data were preprocessed and analyzed, and genes with a P 2.5 were considered to be differentially expressed. Differentially expressed genes were analyzed for overlap with known networks by using pathway analysis tools. There were significant temporal (P regional differences in gene expression for LH(BETA)T(AG) retinoblastoma tumors. At P 2.5, there were significant changes in gene expression of 190 genes apically, 84 genes anterolaterally, 126 genes posteriorly, 56 genes centrally, and 134 genes at the base. Differentially expressed genes overlapped with known networks, with significant involvement in regulation of cellular proliferation and growth, response to oxygen levels and hypoxia, regulation of cellular processes, cellular signaling cascades, and angiogenesis. There are significant temporal and regional variations in the LH(BETA)T(AG) retinoblastoma model. Differentially expressed genes overlap with key pathways that may play pivotal roles in murine retinoblastoma development. These findings suggest the mechanisms involved in tumor growth and progression in murine retinoblastoma tumors and identify pathways for analysis at a functional level, to determine significance in human retinoblastoma. Microarray analysis of LH(BETA)T(AG) retinal tumors showed significant regional and temporal variations in gene expression, including dysregulation of genes involved in hypoxic responses and angiogenesis.

Simulations of the L-H transition on experimental advanced superconducting Tokamak

International Nuclear Information System (INIS)

Weiland, Jan

2014-01-01

We have simulated the L-H transition on the EAST tokamak [Baonian Wan, EAST and HT-7 Teams, and International Collaborators, “Recent experiments in the EAST and HT-7 superconducting tokamaks,” Nucl. Fusion 49, 104011 (2009)] using a predictive transport code where ion and electron temperatures, electron density, and poloidal and toroidal momenta are simulated self consistently. This is, as far as we know, the first theory based simulation of an L-H transition including the whole radius and not making any assumptions about where the barrier should be formed. Another remarkable feature is that we get H-mode gradients in agreement with the α – α d diagram of Rogers et al. [Phys. Rev. Lett. 81, 4396 (1998)]. Then, the feedback loop emerging from the simulations means that the L-H power threshold increases with the temperature at the separatrix. This is a main feature of the C-mod experiments [Hubbard et al., Phys. Plasmas 14, 056109 (2007)]. This is also why the power threshold depends on the direction of the grad B drift in the scrape off layer and also why the power threshold increases with the magnetic field. A further significant general H-mode feature is that the density is much flatter in H-mode than in L-mode

Solvation effect of bacteriochlorophyll excitons in light-harvesting complex LH2.

Science.gov (United States)

Urboniene, V; Vrublevskaja, O; Trinkunas, G; Gall, A; Robert, B; Valkunas, L

2007-09-15

We have characterized the influence of the protein environment on the spectral properties of the bacteriochlorophyll (Bchl) molecules of the peripheral light-harvesting (or LH2) complex from Rhodobacter sphaeroides. The spectral density functions of the pigments responsible for the 800 and 850 nm electronic transitions were determined from the temperature dependence of the Bchl absorption spectra in different environments (detergent micelles and native membranes). The spectral density function is virtually independent of the hydrophobic support that the protein experiences. The reorganization energy for the B850 Bchls is 220 cm(-1), which is almost twice that of the B800 Bchls, and its Huang-Rhys factor reaches 8.4. Around the transition point temperature, and at higher temperatures, both the static spectral inhomogeneity and the resonance interactions become temperature-dependent. The inhomogeneous distribution function of the transitions exhibits less temperature dependence when LH2 is embedded in membranes, suggesting that the lipid phase protects the protein. However, the temperature dependence of the fluorescence spectra of LH2 cannot be fitted using the same parameters determined from the analysis of the absorption spectra. Correct fitting requires the lowest exciton states to be additionally shifted to the red, suggesting the reorganization of the exciton spectrum.

Directed formation of micro- and nanoscale patterns of functional light-harvesting LH2 complexes.

Science.gov (United States)

Reynolds, Nicholas P; Janusz, Stefan; Escalante-Marun, Maryana; Timney, John; Ducker, Robert E; Olsen, John D; Otto, Cees; Subramaniam, Vinod; Leggett, Graham J; Hunter, C Neil

2007-11-28

The precision placement of the desired protein components on a suitable substrate is an essential prelude to any hybrid "biochip" device, but a second and equally important condition must also be met: the retention of full biological activity. Here we demonstrate the selective binding of an optically active membrane protein, the light-harvesting LH2 complex from Rhodobacter sphaeroides, to patterned self-assembled monolayers at the micron scale and the fabrication of nanometer-scale patterns of these molecules using near-field photolithographic methods. In contrast to plasma proteins, which are reversibly adsorbed on many surfaces, the LH2 complex is readily patterned simply by spatial control of surface polarity. Near-field photolithography has yielded rows of light-harvesting complexes only 98 nm wide. Retention of the native optical properties of patterned LH2 molecules was demonstrated using in situ fluorescence emission spectroscopy.

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

Science.gov (United States)

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

2011-01-01

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

Self diffusion and spectral modifications of a membrane protein, the Rubrivivax gelatinosus LH2 complex, incorporated into a monoolein cubic phase.

OpenAIRE

Tsapis, N; Reiss-Husson, F; Ober, R; Genest, M; Hodges, R S; Urbach, W

2001-01-01

The light-harvesting complex LH2 from a purple bacterium, Rubrivivax gelatinosus, has been incorporated into the Q230 cubic phase of monoolein. We measured the self-diffusion of LH2 in detergent solution and in the cubic phase by fluorescence recovery after photobleaching. We investigated also the absorption and fluorescence properties of this oligomeric membrane protein in the cubic phase, in comparison with its beta-octyl glucoside solution. In these experiments, native LH2 and LH2 labeled ...

Separation of prostaglandin metabolites on sephadex LH 20 columns

DEFF Research Database (Denmark)

Hansen, Harald S.; Bukhave, K.

1978-01-01

Sephadex LH 20 columns have been investigated for the separation of initial prostaglandin metabolites. Solvent systems are described for the separation of the free acids of 15-keto-dihydro-PGE, 15-keto-PGE, PGE, and PGF(1a). Further, one of the solvent systems is described for the separation...

Heterogeneity of carotenoid content and composition in LH2 of the purple sulphur bacterium Allochromatium minutissimum grown under carotenoid-biosynthesis inhibition.

Science.gov (United States)

Makhneva, Zoya; Bolshakov, Maksim; Moskalenko, Andrey

2008-01-01

The effects brought about by growing Allochromatium (Alc.) minutissimum in the presence of different concentrations of the carotenoid (Car) biosynthetic inhibitor diphenylamine (DPA) have been investigated. A decrease of Car content (from approximately 70% to >5%) in the membranes was accompanied by an increase of the percentage of (immature) Cars with reduced numbers of conjugated C=C bonds (from neurosporene to phytoene). Based on the obtained results and the analysis of literature data, the conclusion is reached that accumulation of phytoene during inhibition did not occur. Surprisingly, DPA inhibited phytoene synthase instead of phytoene desaturase as generally assumed. The distribution of Cars in peripheral antenna (LH2) complexes and their effect on the stability of LH2 has been investigated using absorption spectroscopy and HPLC analysis. Heterogeneity of Car composition and contents in the LH2 pool is revealed. The Car contents in LH2 varied widely from control levels to complete absence. According to common view, the assembly of LH2 occurs only in the presence of Cars. Here, we show that the LH2 can be assembled without any Cars. The presence of Cars, however, is important for structural stability of LH2 complexes.

Fluorescence polarization measures energy funneling in single light-harvesting antennas--LH2 vs conjugated polymers.

Science.gov (United States)

Camacho, Rafael; Tubasum, Sumera; Southall, June; Cogdell, Richard J; Sforazzini, Giuseppe; Anderson, Harry L; Pullerits, Tõnu; Scheblykin, Ivan G

2015-10-19

Numerous approaches have been proposed to mimic natural photosynthesis using artificial antenna systems, such as conjugated polymers (CPs), dendrimers, and J-aggregates. As a result, there is a need to characterize and compare the excitation energy transfer (EET) properties of various natural and artificial antennas. Here we experimentally show that EET in single antennas can be characterized by 2D polarization imaging using the single funnel approximation. This methodology addresses the ability of an individual antenna to transfer its absorbed energy towards a single pool of emissive states, using a single parameter called energy funneling efficiency (ε). We studied individual peripheral antennas of purple bacteria (LH2) and single CP chains of 20 nm length. As expected from a perfect antenna, LH2s showed funneling efficiencies close to unity. In contrast, CPs showed lower average funneling efficiencies, greatly varying from molecule to molecule. Cyclodextrin insulation of the conjugated backbone improves EET, increasing the fraction of CPs possessing ε = 1. Comparison between LH2s and CPs shows the importance of the protection systems and the protein scaffold of LH2, which keep the chromophores in functional form and at such geometrical arrangement that ensures excellent EET.

Peripheral Light-Harvesting LH2 Complex Can Be Assembled in Cells of Nonsulfur Purple Bacterium Rhodoblastus acidophilus without Carotenoids.

Science.gov (United States)

Bol'shakov, M A; Ashikhmin, A A; Makhneva, Z K; Moskalenko, A A

2015-09-01

The effect of carotenoids on the assembly of LH2 complex in cells of the purple nonsulfur bacterium Rhodoblastus acidophilus was investigated. For this purpose, the bacterial culture was cultivated with an inhibitor of carotenoid biosynthesis - 71 µM diphenylamine (DPA). The inhibitor decreased the level of biosynthesis of the colored carotenoids in membranes by ~58%. It was found that a large amount of phytoene was accumulated in them. This carotenoid precursor was bound nonspecifically to LH2 complex and did not stabilize its structure. Thermostability testing of the isolated LH2 complex together with analysis of carotenoid composition revealed that the population of this complex was heterogeneous with respect to carotenoid composition. One fraction of the LH2 complex with carotenoid content around 90% remains stable and was not destroyed under heating for 15 min at 50°C. The other fraction of LH2 complex containing on average less than one molecule of carotenoid per complex was destroyed under heating, forming a zone of free pigments (and polypeptides). The data suggest that a certain part of the LH2 complexes is assembled without carotenoids in cells of the nonsulfur bacterium Rbl. acidophilus grown with DPA. These data contradict the fact that the LH2 complex from nonsulfur bacteria cannot be assembled without carotenoids, but on the other hand, they are in good agreement with the results demonstrated in our earlier studies of the sulfur bacteria Allochromatium minutissimum and Ectothiorhodospira haloalkaliphila. Carotenoidless LH2 complex was obtained from these bacteria with the use of DPA (Moskalenko, A. A., and Makhneva, Z. K. (2012) J. Photochem. Photobiol., 108, 1-7; Ashikhmin, A., et al. (2014) Photosynth. Res., 119, 291-303).

Resumption of menstruation and pituitary response to gonadotropin-releasing hormone in functional hypothalamic amenorrhea subjects undertaking estrogen replacement therapy.

Science.gov (United States)

Shen, Z Q; Xu, J J; Lin, J F

2013-11-01

Functional hypothalamic amenorrhea (FHA) refers to a functional menstrual disorder with various causes and presentations. Recovery of menstrual cyclicity is common in long-term follow-up but the affecting factors remain unknown. To explore factors affecting the menstrual resumption and to evaluate the pituitary response to gonadotropin-releasing hormone (GnRH) in FHA. Thirty cases with FHA were recruited. All subjects were put on continuous 1 mg/day estradiol valerate orally and followed up monthly. Recovery was defined as the occurrence of at least three consecutive regular cycles. Responder referred to those who recovered within two years of therapy. Gonadotropin response to the 50 μg GnRH challenge was tested every three months. Nineteen (63.3%) subjects recovered with a mean time to recovery of 26.8 months. Time to recovery was negatively correlated with body mass index (BMI) before and by amenorrhea. Twentyone cases had undertaken therapy for more than two years and 10 of them recovered. BMI before and by amenorrhea were negatively correlated with the recovery. Significant increase of serum luteinizing hormone (LH) and LH response to GnRH were noted after recovery. Menstrual resumption was common in FHA undertaking estrogen replacement therapy (ERT). The likelihood of recovery was affected by their BMI before and by amenorrhea but not by the weight gain during therapy. Low serum LH and attenuated LH response to GnRH were the main features of pituitary deficiency in FHA. The menstrual resumption in FHA was accompanied by the recovery of serum LH and the LH response to GnRH.

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

Directory of Open Access Journals (Sweden)

Musgrove Lois C

2001-11-01

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

Ultrafast time-resolved carotenoid to-bacteriochlorophyll energy transfer in LH2 complexes from photosynthetic bacteria.

Science.gov (United States)

Cong, Hong; Niedzwiedzki, Dariusz M; Gibson, George N; LaFountain, Amy M; Kelsh, Rhiannon M; Gardiner, Alastair T; Cogdell, Richard J; Frank, Harry A

2008-08-28

Steady-state and ultrafast time-resolved optical spectroscopic investigations have been carried out at 293 and 10 K on LH2 pigment-protein complexes isolated from three different strains of photosynthetic bacteria: Rhodobacter (Rb.) sphaeroides G1C, Rb. sphaeroides 2.4.1 (anaerobically and aerobically grown), and Rps. acidophila 10050. The LH2 complexes obtained from these strains contain the carotenoids, neurosporene, spheroidene, spheroidenone, and rhodopin glucoside, respectively. These molecules have a systematically increasing number of pi-electron conjugated carbon-carbon double bonds. Steady-state absorption and fluorescence excitation experiments have revealed that the total efficiency of energy transfer from the carotenoids to bacteriochlorophyll is independent of temperature and nearly constant at approximately 90% for the LH2 complexes containing neurosporene, spheroidene, spheroidenone, but drops to approximately 53% for the complex containing rhodopin glucoside. Ultrafast transient absorption spectra in the near-infrared (NIR) region of the purified carotenoids in solution have revealed the energies of the S1 (2(1)Ag-)-->S2 (1(1)Bu+) excited-state transitions which, when subtracted from the energies of the S0 (1(1)Ag-)-->S2 (1(1)Bu+) transitions determined by steady-state absorption measurements, give precise values for the positions of the S1 (2(1)Ag-) states of the carotenoids. Global fitting of the ultrafast spectral and temporal data sets have revealed the dynamics of the pathways of de-excitation of the carotenoid excited states. The pathways include energy transfer to bacteriochlorophyll, population of the so-called S* state of the carotenoids, and formation of carotenoid radical cations (Car*+). The investigation has found that excitation energy transfer to bacteriochlorophyll is partitioned through the S1 (1(1)Ag-), S2 (1(1)Bu+), and S* states of the different carotenoids to varying degrees. This is understood through a consideration of the

Crystallization and preliminary X-ray diffraction analysis of the peripheral light-harvesting complex LH2 from Marichromatium purpuratum.

Science.gov (United States)

Cranston, Laura J; Roszak, Aleksander W; Cogdell, Richard J

2014-06-01

LH2 from the purple photosynthetic bacterium Marichromatium (formerly known as Chromatium) purpuratum is an integral membrane pigment-protein complex that is involved in harvesting light energy and transferring it to the LH1-RC `core' complex. The purified LH2 complex was crystallized using the sitting-drop vapour-diffusion method at 294 K. The crystals diffracted to a resolution of 6 Å using synchrotron radiation and belonged to the tetragonal space group I4, with unit-cell parameters a=b=109.36, c=80.45 Å. The data appeared to be twinned, producing apparent diffraction symmetry I422. The tetragonal symmetry of the unit cell and diffraction for the crystals of the LH2 complex from this species reveal that this complex is an octamer.

Small scale purification of human pituitary lutropin (hLH) for use in radioligand assays

International Nuclear Information System (INIS)

Schwarz, I.; Morgante, L.; Bartolini, P.

1988-08-01

Human lutropin (hLH) is a relatively unstable protein, which even in lyophilised form tends to dissociate into subunits during long storage periods. Considering the limited disposibilty of human pituitaries, a small-scale extraction method is proposed for radioassays. Starting from 10 and 20 hypophyses after Sephadex G 100 purification, 10 μg/gland with approximate 10% purity was obtained. After the last purification, hLH recovery was of 1.5 μg/gland. (author) [pt

Singlet-triplet fission of carotenoid excitation in light-harvesting LH2 complexes of purple phototrophic bacteria.

Science.gov (United States)

Klenina, I B; Makhneva, Z K; Moskalenko, A A; Gudkov, N D; Bolshakov, M A; Pavlova, E A; Proskuryakov, I I

2014-03-01

The current generally accepted structure of light-harvesting LH2 complexes from purple phototrophic bacteria conflicts with the observation of singlet-triplet carotenoid excitation fission in these complexes. In LH2 complexes from the purple bacterium Allochromatium minutissimum, a drop in the efficiency of carotenoid triplet generation is demonstrated, which correlates with the extent of selective photooxidation of bacteriochlorophylls absorbing at ~850 nm. We conclude that singlet-triplet fission of carotenoid excitation proceeds with participation of these excitonically coupled bacteriochlorophylls. In the framework of the proposed mechanism, the contradiction between LH2 structure and photophysical properties of carotenoids is eliminated. The possibility of singlet-triplet excitation fission involving a third mediator molecule was not considered earlier.

Carotenoid-to-bacteriochlorophyll energy transfer through vibronic coupling in LH2 from Phaeosprillum molischianum.

Science.gov (United States)

Thyrhaug, Erling; Lincoln, Craig N; Branchi, Federico; Cerullo, Giulio; Perlík, Václav; Šanda, František; Lokstein, Heiko; Hauer, Jürgen

2018-03-01

The peripheral light-harvesting antenna complex (LH2) of purple photosynthetic bacteria is an ideal testing ground for models of structure-function relationships due to its well-determined molecular structure and ultrafast energy deactivation. It has been the target for numerous studies in both theory and ultrafast spectroscopy; nevertheless, certain aspects of the convoluted relaxation network of LH2 lack a satisfactory explanation by conventional theories. For example, the initial carotenoid-to-bacteriochlorophyll energy transfer step necessary on visible light excitation was long considered to follow the Förster mechanism, even though transfer times as short as 40 femtoseconds (fs) have been observed. Such transfer times are hard to accommodate by Förster theory, as the moderate coupling strengths found in LH2 suggest much slower transfer within this framework. In this study, we investigate LH2 from Phaeospirillum (Ph.) molischianum in two types of transient absorption experiments-with narrowband pump and white-light probe resulting in 100 fs time resolution, and with degenerate broadband 10 fs pump and probe pulses. With regard to the split Q x band in this system, we show that vibronically mediated transfer explains both the ultrafast carotenoid-to-B850 transfer, and the almost complete lack of transfer to B800. These results are beyond Förster theory, which predicts an almost equal partition between the two channels.

Total Wellness and Holistic Health: A Bandwagon We Cannot Afford to Jump Onto

Science.gov (United States)

Sechrist, William C.

1979-01-01

The changing public attitude towards "total wellness" creates pressure for health educators to desert the basic problem-oriented research programs in favor of nebulous, unmeasurable, but conspicuous targets such as "holistic health." (LH)

Airline view of LH2 as a fuel for commercial aircraft

Energy Technology Data Exchange (ETDEWEB)

Wilkinson, K.G.

1983-01-01

Fuel for air transport is a particularly important matter, because it is an energy-intensive form of transport. Price and energy density are therefore correspondingly critical. Airlines views tend to be short term because there is no future if they do not survive tomorrow. Thus, although petroleum supply and price has been unstable since 1973, airlines' primary concern has been with economizing the use of fuel and specifying more fuel economic equipment for the future, rather than serious pursuit of more radical solutions. LH2 gives promise of being a serious candidate for the longer term, but there is not yet convincing proof that cheaper seat mile costs could be produced in today's circumstances. The situation could be changed by the realization of laminar flow by surface cooling at subsonic speeds. There is a strong case for a modest programme of carefully aimed research on an international basis to fill the most important gaps in our knowledge on the design of LH2 fueled aircraft. Future crises in energy supplies may well raise questions of transport fuel strategy which will heed this background for wise decision-making. Particular significance attaches to the place of nuclear power in world energy policy since this dominates the question of LH2 availability and price. 2 references, 2 figures.

The 21st LH Gray Conference (June 4-6, 2008)

Energy Technology Data Exchange (ETDEWEB)

West, C. M. L. [Univ. of Manchester (United Kingdom); Martin, C. J. [Gartnavel Royal Hospital, Glasgow (United Kingdom); Sutton, D. G. [Ninewells Hospital and Medical School, Dundee (United Kingdom); Wright, E. G. [Ninewells Hospital and Medical School, Dundee (United Kingdom)

2009-01-12

The 21st LH Gray Conference, organised by the LH Gray Trust with the Society for Radiological Protection, brought together international experts in radiobiology, epidemiology and risk assessment, and scientists involved in diagnostic and therapeutic radiation exposure. The meeting - held in Edinburgh, Scotland 4-6 June 2008 - aimed to raise awareness, educate and share knowledge of important issues in radiation protection. A distinguished group of speakers discussed topics which included: non-targeted effects of radiation, exposure to high natural background radiation, non-cancer effects in Japanese bomb survivors, lessons learnt from Chernobyl, radiation in the workplace, biokinetic modelling, uncertainties in risk estimation, issues in diagnostic medical exposures, lessons leant from the polonium-210 incidence and how the radiobiology-radiation oncology community is needed to help society prepare for potential future acts of radiation terrorism. The conference highlighted the importance, relevance and topicality of radiobiology today.

Fast renal trapping of porcine Luteinizing Hormone (pLH shown by 123I-scintigraphic imaging in rats explains its short circulatory half-life

Directory of Open Access Journals (Sweden)

Locatelli Alain

2003-10-01

Full Text Available Abstract Background Sugar moieties of gonadotropins play no primary role in receptor binding but they strongly affect their circulatory half-life and consequently their in vivo biopotencies. In order to relate more precisely hepatic trapping of these glycoproteic hormones with their circulatory half-life, we undertook a comparative study of the distribution and elimination of porcine LH (pLH and equine CG (eCG which exhibit respectively a short and a long half-life. This was done first by following half-lives of pLH in piglets with hepatic portal circulation shunted or not. It was expected that such a shunt would enhance the short half-life of pLH. Subsequently, scintigraphic imaging of both 123I-pLH and 123I-eCG was performed in intact rats to compare their routes and rates of distribution and elimination. Methods Native pLH or eCG was injected to normal piglets and pLH was tested in liver-shunted anæsthetized piglet. Blood samples were recovered sequentially over one hour time and the hormone concentrations were determined by a specific ELISA method. Scintigraphic imaging of 123I-pLH and 123I-eCG was performed in rats using a OPTI-CGR gamma camera. Results In liver-shunted piglets, the half-life of pLH was found to be as short as in intact piglets (5 min. In the rat, the half-life of pLH was also found to be very short (3–6 min and 123I-pLH was found to accumulate in high quantity in less than 10 min post injection at the level of kidneys but not in the liver. 123I-eCG didn't accumulate in any organ in the rats during the first hour, plasma concentrations of this gonadotropin being still elevated (80% at this time. Conclusion In both the porcine and rat species, the liver is not responsible for the rapid elimination of pLH from the circulation compared to eCG. Our scintigraphic experiments suggest that the very short circulatory half-life of LH is due to rapid renal trapping.

PENGARUH PEMBERIAN MONOSODIUM GLUTAMAT (MSG PADA TIKUS JANTAN (Rattus Norvegicus TERHADAP FSH DAN LH

Directory of Open Access Journals (Sweden)

Zulkarnain Edward

2010-09-01

Full Text Available AbstrakKemajuan teknologi informasi membawa dampak terhadap perubahan gaya hidup masyarakat, termasuk perubahan pola konsumsi makanan yang lebih banyak mengkonsumsi jenis makanan cepat saji, makanan kemasan dan makanan awetan yang belakangan ini semakin banyak dijual dipasar tradisional dan swalayan. Penggunaan bahan tambahan makanan sering dijumpai, salah satunya adalah bahan penyedap yang banyak sekali digunakan seperti senyawa L-asam glutamat yang digunakan dalam bentuk garam yaitu monosodium glutamat (MSG. Berbagai merk dagang MSG telah dikenal dimasyarakat secara luas seperti ajinomoto, vetsin, micin, sasa, miwon dan sebagainya.MSG adalah garam monosodium dengan asam glutamat yang sering digunakan sebagai bahan penyedap masakan untuk merangsang selera makan. Pemberian MSG mengakibatkan gangguan hormonal pada hewan coba, ion glutamat dalam sirkulasi portal akan mempengaruhi hipotalamus dalam memproduksi GnRH yang selanjutnya akan mengganggu hipofise anterior dalam memproduksi FSH dan LH. Fungsi FSH adalah untuk bekerja pada tubulus seminiferus terutama pada sel sertoli untuk meningkatkan spermatogenesis, sedangkan LH berfungsi pada sel Leydig untuk mengatur sekresi testosteron.Penelitian ini bersifat eksperimen dengan rancangan post only group design. Penelitian dilakukan di laboratorium Biologi dan laboratorium Biokimia Fakultas Kedokteran Unand Padang dari tanggal 20 Desember 2009 sampai 30 Februari 2010. Populasi adalah tikus putih jantan strain Jepang (Rattus norvegicus yang berasal dari laboratorium Fakultas Matematika dan Ilmu Pengetahuan Alam Unand. Sampel berjumlah 20 ekor dibagi atas 4 kelompok dengan satu kelompok kontrol dan tiga kelompok perlakuan. Dosis MSG yang digunakan yaitu P1= 4800 mg/kgbb/hari, P2=7200 mg/kgbb/hari dan P3= 9600 mg/kgbb/hari diberikan peroral sebanyak dua siklus epitel seminiferus. Analisa dengan uji Anova dengan derajat kepercayaan 95% dan jika bermakna dilanjutkan dengan uji Multiple Comparissons jenis

Fluorescence polarization measures energy funneling in single light-harvesting antennas—LH2 vs conjugated polymers

Science.gov (United States)

Camacho, Rafael; Tubasum, Sumera; Southall, June; Cogdell, Richard J.; Sforazzini, Giuseppe; Anderson, Harry L.; Pullerits, Tõnu; Scheblykin, Ivan G.

2015-10-01

Numerous approaches have been proposed to mimic natural photosynthesis using artificial antenna systems, such as conjugated polymers (CPs), dendrimers, and J-aggregates. As a result, there is a need to characterize and compare the excitation energy transfer (EET) properties of various natural and artificial antennas. Here we experimentally show that EET in single antennas can be characterized by 2D polarization imaging using the single funnel approximation. This methodology addresses the ability of an individual antenna to transfer its absorbed energy towards a single pool of emissive states, using a single parameter called energy funneling efficiency (ɛ). We studied individual peripheral antennas of purple bacteria (LH2) and single CP chains of 20 nm length. As expected from a perfect antenna, LH2s showed funneling efficiencies close to unity. In contrast, CPs showed lower average funneling efficiencies, greatly varying from molecule to molecule. Cyclodextrin insulation of the conjugated backbone improves EET, increasing the fraction of CPs possessing ɛ = 1. Comparison between LH2s and CPs shows the importance of the protection systems and the protein scaffold of LH2, which keep the chromophores in functional form and at such geometrical arrangement that ensures excellent EET.

Dual fluorescence of single LH2 antenna nanorings

International Nuclear Information System (INIS)

Freiberg, A.; Raetsep, M.; Timpmann, K.; Trinkunas, G.

2004-01-01

A dual nature of fluorescence from LH2 pigment-protein complexes, which is a part of the light harvesting system of purple bacteria, is confirmed by fluorescence-lifetime dependence on recording wavelength and spectrally selective spectroscopy. An analysis based on the Holstein molecular crystal model, modified by allowing diagonal disorder, suggests coexistence of large- and small-radius self-trapped excitons, which serve as the origin of the dual fluorescence

Molecular Level Design Principle behind Optimal Sizes of Photosynthetic LH2 Complex: Taming Disorder through Cooperation of Hydrogen Bonding and Quantum Delocalization.

Science.gov (United States)

Jang, Seogjoo; Rivera, Eva; Montemayor, Daniel

2015-03-19

The light harvesting 2 (LH2) antenna complex from purple photosynthetic bacteria is an efficient natural excitation energy carrier with well-known symmetric structure, but the molecular level design principle governing its structure-function relationship is unknown. Our all-atomistic simulations of nonnatural analogues of LH2 as well as those of a natural LH2 suggest that nonnatural sizes of LH2-like complexes could be built. However, stable and consistent hydrogen bonding (HB) between bacteriochlorophyll and the protein is shown to be possible only near naturally occurring sizes, leading to significantly smaller disorder than for nonnatural ones. Extensive quantum calculations of intercomplex exciton transfer dynamics, sampled for a large set of disorder, reveal that taming the negative effect of disorder through a reliable HB as well as quantum delocalization of the exciton is a critical mechanism that makes LH2 highly functional, which also explains why the natural sizes of LH2 are indeed optimal.

Spectral heterogeneity and carotenoid-to-bacteriochlorophyll energy transfer in LH2 light-harvesting complexes from Allochromatium vinosum.

Science.gov (United States)

Magdaong, Nikki M; LaFountain, Amy M; Hacking, Kirsty; Niedzwiedzki, Dariusz M; Gibson, George N; Cogdell, Richard J; Frank, Harry A

2016-02-01

Photosynthetic organisms produce a vast array of spectral forms of antenna pigment-protein complexes to harvest solar energy and also to adapt to growth under the variable environmental conditions of light intensity, temperature, and nutrient availability. This behavior is exemplified by Allochromatium (Alc.) vinosum, a photosynthetic purple sulfur bacterium that produces different types of LH2 light-harvesting complexes in response to variations in growth conditions. In the present work, three different spectral forms of LH2 from Alc. vinosum, B800-820, B800-840, and B800-850, were isolated, purified, and examined using steady-state absorption and fluorescence spectroscopy, and ultrafast time-resolved absorption spectroscopy. The pigment composition of the LH2 complexes was analyzed by high-performance liquid chromatography, and all were found to contain five carotenoids: lycopene, anhydrorhodovibrin, spirilloxanthin, rhodopin, and rhodovibrin. Spectral reconstructions of the absorption and fluorescence excitation spectra based on the pigment composition revealed significantly more spectral heterogeneity in these systems compared to LH2 complexes isolated from other species of purple bacteria. The data also revealed the individual carotenoid-to-bacteriochlorophyll energy transfer efficiencies which were correlated with the kinetic data from the ultrafast transient absorption spectroscopic experiments. This series of LH2 complexes allows a systematic exploration of the factors that determine the spectral properties of the bound pigments and control the rate and efficiency of carotenoid-to-bacteriochlorophyll energy transfer.

The effects of Vitex agnus castus extract and its interaction with dopaminergic system on LH and testosterone in male mice.

Science.gov (United States)

Nasri, Sima; Oryan, Shahrbano; Rohani, Ali Haeri; Amin, Gholam Reza

2007-07-15

The purpose of this study was to evaluate the probable effects of Vitex agnus castus (Vac.) on the male reproductive physiology. It is a well known fact that LH secretion from the anterior pituitary of mammals is controlled by many neurotransmiters such as dopamine. In this experiment, we have studied the effect of Vac. extract on the LH and testosterone hormones and its interaction with the dopaminergic system on male mice. In order to evaluate these effects, we used the hydroalcoholic Vac. extract (for extraction we used percolation technique) injection with the following doses: 65, 165, 265, 365 and 465 mg kg-', bromocriptine as a dopamine receptor agonist (5, 10, 20 mg kg(-1)) and haloperidol as a dopamine receptor antagonist (1, 1.5, 2, 2.5, 3 mg kg(-1)). To study the interaction between Vac. extract and dopaminergic system, we injected the optimum doses of Vac. with bromocriptine or haloperidol at the same time. Intraperitoneal injections were applied in all experiments, once a day for 30 days. The control group remained intact and the sham group received vehicle. After the last injection, we collected the animal blood serums for hormonal assays. LH and testosterone were measured by Radio Immuno Assay (RIA). LH and testosterone, showed significant decrease in bromocriptine group and haloperidol increased these hormones. Vac. extract decreased significantly the LH and testosterone levels. The coadministration of Vac. extract and bromocriptine decreased LH and testosterone. Coadministration of Vac. extract and haloperidol decreased LH and testosterone levels. These results suggest: dopamine regulates the gonadotroph-leydig cells axis. It appears that Vac. exertes effects through dopaminergic system and other pathways. The findings of this study show we can use Vac. extract for pathological cases of increasing LH and testosterone.

LH-21 and abnormal cannabidiol improve β-cell function in isolated human and mouse islets through GPR55-dependent and -independent signalling.

Science.gov (United States)

Ruz-Maldonado, Inmaculada; Pingitore, Attilio; Liu, Bo; Atanes, Patricio; Huang, Guo Cai; Baker, David; Alonso, Francisco José; Bermúdez-Silva, Francisco Javier; Persaud, Shanta J

2018-04-01

To examine the effects of Abn-CBD (GPR55 agonist) and LH-21 (CB1 antagonist) on human and mouse islet function, and to determine signalling via GPR55 using islets from GPR55 -/- mice. Islets isolated from human organ donors and mice were incubated in the absence or presence of Abn-CBD or LH-21, and insulin secretion, [Ca 2+ ] i, cAMP , apoptosis, β-cell proliferation and CREB and AKT phosphorylation were examined using standard techniques. Abn-CBD potentiated glucose-stimulated insulin secretion and elevated [Ca 2+ ] i in human islets and islets from both GPR55 +/+ and GPR55 -/- mice. LH-21 also increased insulin secretion and [Ca 2+ ] i in human islets and GPR55 +/+ mouse islets, but concentrations of LH-21 up to 0.1 μM were ineffective in islets from GPR55 -/- mice. Neither ligand affected basal insulin secretion or islet cAMP levels. Abn-CBD and LH-21 reduced cytokine-induced apoptosis in human islets and GPR55 +/+ mouse islets, and these effects were suppressed after GPR55 deletion. They also increased β-cell proliferation: the effects of Abn-CBD were preserved in islets from GPR55 -/- mice, while those of LH-21 were abolished. Abn-CBD and LH-21 increased AKT phosphorylation in mouse and human islets. This study showed that Abn-CBD and LH-21 improve human and mouse islet β-cell function and viability. Use of islets from GPR55 -/- mice suggests that designation of Abn-CBD and LH-21 as a GPR55 agonist and a CB1 antagonist, should be revised. © 2017 John Wiley & Sons Ltd.

Comparison of four mathematical models for the calculation of radioimmunoassay data of LH, FSH and GH

International Nuclear Information System (INIS)

Geier, T.; Rohde, W.

1981-01-01

Weighted linear logit-log regression, point-to-point logit-log interpolation, smoothing spline approximation and the four-parameter logistic function calculated by non-linear regression have been compared. The data for comparison have been obtained from two different pool-sera for each of the LH-, FSH- and GH-RIA and from the basal serum LH values of two populations of children. The Wilcoxon matched pairs signed rank test was used for comparison: For GH there is no significant difference between all methods, for FSH the weighted linear logit-log regression and spline approximation appeared to be equivalent, but for LH no unequivocal assertion can be made. There is no significant difference between the mathematical models for determination of hormone concentration within one assay run of a population as exemplified for LH. In addition, pool sera data were subjected to an analysis of variance and the comparison of the results revealed that the different models did not lead to different statements about assay performance. The point-to-point logit-log interpolation is proposed as most simple curvilinear approximation for assays which cannot be linearized by logit-log transformation. (author)

Internalization of Rat FSH and LH/CG Receptors by rec-eCG in CHO-K1 Cells.

Science.gov (United States)

Park, Jong-Ju; Seong, Hun-Ki; Kim, Jeong-Soo; Munkhzaya, Byambaragchaa; Kang, Myung-Hwa; Min, Kwan-Sik

2017-06-01

Equine chorionic gonadotropin (eCG) is a unique molecule that elicits the response characteristics of both follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in other species. Previous studies from this laboratory had demonstrated that recombinant eCG (rec-eCG) from Chinese hamster ovary (CHO-K1) cells exhibited both FSH- and LH-like activity in rat granulosa and Leydig cells. In this study, we analyzed receptor internalization through rec-eCGs, wild type eCG (eCGβ/α) and mutant eCG (eCGβ/αΔ56) with an N-linked oligosaccharide at Asn 56 of the α-subunit. Both the rec-eCGs were obtained from CHO-K1 cells. The agonist activation of receptors was analyzed by measuring stimulation time and concentrations of rec-eCGs. Internalization values in the stably selected rat follicle-stimulating hormone receptor (rFSHR) and rat luteinizing/chorionic gonadotropin receptor (rLH/CGR) were highest at 50 min after stimulation with 10 ng of rec-eCGβ/α. The dose-dependent response was highest when 10 ng of rec-eCGβ/α was used. The deglycosylated eCGβ/αΔ56 mutant did not enhance the agonist-stimulated internalization. We concluded that the state of activation of rFSHR and rLH/CGR could be modulated through agonist-stimulated internalization. Our results suggested that the eLH/CGRs are mostly internalized within 60 min by agonist-stimulation by rec-eCG. We also suggested that the lack of responsiveness of the deglycosylated eCGβ/ αΔ56 was likely because the site of glycosylation played a pivotal role in agonist-stimulated internalization in cells expressing rFSHR and rLH/CGR.

Normal levels of plasma FSH and LH in the menstrual cycle as determined by radioimmunoassay

International Nuclear Information System (INIS)

Lemgruber, I.; Pinto, J.C.M.; Linhares, E.; Granafer, A.

1981-01-01

The biological methods were not able to establish adequately the separate determination of FSH and LH. The introduction of radioimmunoassay had allowed the identification of plasma FSH and LH for the purpose of routine clinical use. The utilization of commercial kits, however, obliges each laboratory to have normal levels of his own. Such is the finality of this work, studying samples from 200 normal women, hospitalized for surgical reasons and having not any endocrinological problem. (author) [pt

Minimizing Total Completion Time For Preemptive Scheduling With Release Dates And Deadline Constraints

Directory of Open Access Journals (Sweden)

He Cheng

2014-02-01

Full Text Available It is known that the single machine preemptive scheduling problem of minimizing total completion time with release date and deadline constraints is NP- hard. Du and Leung solved some special cases by the generalized Baker's algorithm and the generalized Smith's algorithm in O(n2 time. In this paper we give an O(n2 algorithm for the special case where the processing times and deadlines are agreeable. Moreover, for the case where the processing times and deadlines are disagreeable, we present two properties which could enable us to reduce the range of the enumeration algorithm

Evaluation of different ranges of LH:FSH ratios in polycystic ovarian syndrome (PCOS) - Clinical based case control study.

Science.gov (United States)

Malini, N A; Roy George, K

2018-05-01

Polycystic ovary syndrome (PCOS) is a highly prevalent endocrine and metabolic disorder among reproductive aged women, leading to infertility. One of the common clinical manifestations in PCOS is that there is a difference in the range of LH production in different case of PCOS and accordingly variability in LH:FSH ratio was observed. The aim of the present study was to evaluate different ranges of LH:FSH ratios in PCOS. In this cross sectional study, a consecutive series of 745 women (aged 28.11 ± 0.2) who were subjected to infertility treatment at specialist infertility clinics in central Travancore region were considered. About 50 healthy females (aged 27.58 ± 0.4) with regular menstrual cycles were regarded as control. The data were collected from hospital records using subject's written informed consent. PCOS patients were observed to have different ranges of LH:FSH ratios from PCOS. Copyright © 2018 Elsevier Inc. All rights reserved.

Biosynthesis of gonadotropin-releasing hormone (GnRH) and GnRH receptor (GnRHR) in hypothalamic-pituitary unit of anoestrous and cyclic ewes.

Science.gov (United States)

Ciechanowska, M O; Łapot, M; Mateusiak, K; Paruszewska, E; Malewski, T; Przekop, F

2017-02-01

This study was performed to explain how the molecular processes governing the biosynthesis of gonadotropin-releasing hormone (GnRH) and GnRH receptor (GnRHR) in the hypothalamic-pituitary unit are reflected by luteinizing hormone (LH) secretion in sheep during anoestrous period and during luteal and follicular phases of the oestrous cycle. Using an enzyme-linked immunosorbent assay (ELISA), we analyzed the levels of GnRH and GnRHR in preoptic area (POA), anterior (AH) and ventromedial hypothalamus (VM), stalk-median eminence (SME), and GnRHR in the anterior pituitary gland (AP). Radioimmunoassay has also been used to define changes in plasma LH concentrations. The study provides evidence that the levels of GnRH in the whole hypothalamus of anoestrous ewes were lower than that in sheep during the follicular phase of the oestrous cycle (POA: p pituitary unit, as well as LH level, in the blood in anoestrous ewes were significantly lower than those detected in animals of both cyclic groups. Our data suggest that decrease in LH secretion during the long photoperiod in sheep may be due to low translational activity of genes encoding both GnRH and GnRHR.

Metal Cations Induced alpha beta-BChl a Heterogeneity in LH1 as Revealed by Temperature-Dependent Fluorescence Splitting

NARCIS (Netherlands)

Ma, Fei; Yu, Long-Jiang; Llansola-Portoles, Manuel J.; Robert, Bruno; Wang-Otomo, Zheng-Yu; van Grondelle, Rienk

2017-01-01

Two spectral forms of the core light-harvesting complex (LH1) of the purple bacterium Thermochromatium (Tch.) tepidum, the native Ca2+-binding and the Ba2+-substituted one, exhibit different fluorescence (FL) emission spectra at low temperature (T). While Ca-LH1 exhibits one emission band, an

[Anthology of the first clinical studies with hypothalamic hormones: a story of successful international cooperation].

Science.gov (United States)

Schally, Andrew V; Gual, Carlos

2002-01-01

Our early pioneering clinical trials in Mexico with natural and synthetic thyrotropin-releasing hormone (TRH) and luteinizing hormone releasing hormone (LH-RH) also known as gonadotropin releasing hormone (Gn-RH), were reviewed. Highly purified TRH of porcine origin was shown to stimulate Thyrotropin (TSH) release in hypothyroid cretins. Subsequent tests with synthetic TRH also demonstrated significant increases in plasma TSH in normal men and women as well as in patients with primary hypothyroidism and other endocrine disorders. Even more extensive clinical studies were carried out with highly purified natural porcine LH-RH. Subjects with normal basal serum levels of gonadotropins, low levels (men and women pretreated with steroids) and high levels (e.g. post menopausal women) all responded to LH-RH with a release of LH and FSH. The results of these early studies with the natural LH-RH were confirmed by the use of synthetic LH-RH. These investigations made in Mexico with TRH and LH-RH preceded all other clinical studies by a wide margin. Subsequently various clinical investigations with LH-RH agonists and antagonists were also carried out. All these studies played a major role in introducing hypothalamic-releasing hormones into clinical medicine.

Immunodetection of Luteinizing Hormone (LH, Follicle-Stimulating Hormone (FSH, Thyroid Stimulating Hormone (TSH and Prolactin (PRL in Brachionus calyciflorus (Rotifera: Monogononta

Directory of Open Access Journals (Sweden)

Jesús Alvarado-Flores

2009-12-01

Full Text Available The endocrine system controls and coordinates behavioral, biochemical, and physiological processes through signal mechanisms using neuropeptides or products of neurosecretory cells. Among invertebrates, this system is poorly studied in rotifers, in which estrogens and androgens significantly affect sexual reproduction. This is the first report of the presence of the Luteinizing Hormone (LH, Follicle-Stimulating Hormone (FSH, Thyroid Stimulating Hormone (TSH and Prolactin (PRL in rotifers. Analyses included the avidin-biotin-peroxidase complex method with primary antibodies LH (Anti-Rat LH serum for RIA, PRL (Anti-Rat PRL serum for RIA, FSH (Anti-Rat FSH serum for RIA and TSH (Anti-Rat TSH serum for RIA. These hormones were found in females, males and parthenogenetic and sexual eggs of the freshwater Brachionus calyciflorus. The immunoreactivity of FSH, LH, TSH and PRL in females was observed in: ovaries, cerebrum, mastax, stomach, lorica, and the stomach gland. However, in males LH was observed only at the trochal disk and cerebrum. The hormones FSH, TSH and PRL, were observed in testicles, contractil vesicles, and cementary gland of males. Regarding amictic or parthenogenetic eggs, the hormones LH, FSH, TSH, and PRL were located mainly in the micromeres, and the staining in the macromeres was weak. On the other hand, in the mictic or sexual eggs the inner shell is stained for the hormones PRL and LH, opposite to the staining of FSH and TSH, located mainly in the embryo. In general, immuno-reactivity was observed in areas important for the reproductive, excretory, digestive and developmental processes. Rev. Biol. Trop. 57 (4: 1049-1058. Epub 2009 December 01.Se logró detectar la presencia de las hormonas: Hormona Luteinizante (LH, Hormona Folículo Estimulante (FSH, Hormona Estimulante de la Tiroides (TSH y Prolactina (PRL en Brachionus calyciflorus siendo el primer reporte de la presencia de dichas hormonas en rotíferos. Estas hormonas fueron

Study of the linear and non-linear coupling of the LH wave to the tokamak plasmas

International Nuclear Information System (INIS)

Preynas, M.

2012-10-01

In order to achieve long pulse operation with a tokamak, additional heating and current drive systems are necessary. High frequency antennas, which deliver several megawatts of power to the plasma, are currently used in several tokamaks. Moreover, a good control of the coupling of the wave launched by the antenna to the edge plasma is required to optimize the efficiency of heating and current drive LH systems. However, non-linear effects which depend on the level of injected power in the plasma strongly damage the coupling of the LH wave at particular edge parameters (density and temperature profiles). Results presented in the manuscript deal with the study of the linear and non-linear coupling of the LH wave to the plasma. In the framework of the commissioning of the Passive Active Multijunction antenna in 2009 on the Tore Supra tokamak aiming at validating the LH system suggested for ITER, the characterisation of its coupling properties was realized from low power experiments. The experimental results, which are compared with the linear coupling code ALOHA, have validated the theoretical predictions of good coupling at edge plasma density around the cut-off density. Besides, the ponderomotive effect is clearly identified as responsible for the deterioration in the coupling of the wave, which is measured under particular edge plasma conditions. A theoretical model combining the coupling of the LH wave with the ponderomotive force is suggested to explain the experimental observations. Thus, a new full wave code (named PICCOLO-2D) was developed and results from simulations validate the working hypothesis of the contribution of the ponderomotive effect in the non-linear observations of LHCD coupling on Tore Supra. (author)

An Ab Initio Description of the Excitonic Properties of LH2 and Their Temperature Dependence.

Science.gov (United States)

Cupellini, Lorenzo; Jurinovich, Sandro; Campetella, Marco; Caprasecca, Stefano; Guido, Ciro A; Kelly, Sharon M; Gardiner, Alastair T; Cogdell, Richard; Mennucci, Benedetta

2016-11-10

The spectroscopic properties of light-harvesting (LH) antennae in photosyntehtic organisms represent a fingerprint that is unique for each specific pigment-protein complex. Because of that, spectroscopic observations are generally combined with structural data from X-ray crystallography to obtain an indirect representation of the excitonic properties of the system. Here, an alternative strategy is presented which goes beyond this empirical approach and introduces an ab initio computational description of both structural and electronic properties and their dependence on the temperature. The strategy is applied to the peripheral light-harvesting antenna complex (LH2) present in purple bacteria. By comparing this model with the one based on the crystal structure, a detailed, molecular level explanation of the absorption and circular dichroism (CD) spectra and their temperature dependence is achieved. The agreement obtained with the experiments at both low and room temperature lays the groundwork for an atomistic understanding of the excitation dynamics in the LH2 system.

Automatic determination of L/H transition times in DIII-D through a collaborative distributed environment

International Nuclear Information System (INIS)

Farias, G.; Vega, J.; González, S.; Pereira, A.; Lee, X.; Schissel, D.; Gohil, P.

2012-01-01

Highlights: ► An automatic predictor of L/H transition times has been implemented for the DIII-D tokamak. ► The system predicts the transition combining two techniques: a morphological pattern recognition algorithm and a support vector machines multi-layer model. ► The predictor is employed within a collaborative distributed computing environment. The system is trained remotely in the Ciemat computer cluster and operated on the DIII-D site. - Abstract: An automatic predictor of L/H transition times has been implemented for the DIII-D tokamak. The system predicts the transition combining two techniques: A morphological pattern recognition algorithm, which estimates the transition based on the waveform of a Dα emission signal, and a support vector machines multi-layer model, which predicts the L/H transition using a non-parametric model. The predictor is employed within a collaborative distributed computing environment. The system is trained remotely in the Ciemat computer cluster and operated on the DIII-D site.

LH power deposition and CD efficiency studies by application of modulated power at JET

International Nuclear Information System (INIS)

Kirov, K.K.; Baranov, Yu.; Mailloux, J.; Mayoral, M.-L.; Nave, M.F.F.; Ongena, J.

2010-01-01

The lower hybrid (LH) power deposition and the current drive (CD) efficiency were assessed by the application of modulated LH power. Density and magnetic field scans were performed and the response of the electron temperature provided by the available electron cyclotron emission diagnostic was investigated by means of fast Fourier transform analysis. An innovative technique based on a comparison between modelled and experimental data was developed and used in the study. The LH waves are absorbed by fast electrons with energies of a few times the thermal one, causing a modification in the electron distribution function (EDF) by creating a plateau in the parallel direction. The phase of the temperature perturbations, φ, as well as the ratio between the amplitudes of the third and the main harmonics, δT e3 /δT e1 , are found to be strongly affected by the plateau of the EDF as the broader the plateau the larger |φ|, (φ e3 /δT e1 are. Transport and Fokker-Planck modelling was used to support this conclusion as well as to interpret the experimental data and hence to assess the LHCD efficiency and deposition profile. The results from the analysis are consistent with broad off-axis LH power deposition profile. For densities between 1 x 10 19 and 4 x 10 19 m -3 , which is the accessibility limit at the highest magnetic field discharges, a gradual shift of the maximum of the power deposition to the periphery and a degradation of the CD efficiency was observed.

Nocturnal Urinary Excretion of FSH and LH in Children and Adolescents With Normal and Early Puberty.

Science.gov (United States)

Kolby, Nanna; Busch, Alexander S; Aksglaede, Lise; Sørensen, Kaspar; Petersen, Jorgen Holm; Andersson, Anna-Maria; Juul, Anders

2017-10-01

Clinical use of single serum gonadotropin measurements in children is limited by the pulsatile secretion of follicle-stimulating hormone (FSH) and luteinizing hormone (LH). However, first morning voided (FMV) urine may integrate the fluctuating gonadotropin serum levels. We aimed to evaluate urinary and serum gonadotropin levels according to age, sex, and pubertal stage in healthy children and to assess the clinical use of FMV urinary gonadotropins in children with disordered puberty. Cross-sectional part of the COPENHAGEN Puberty Study and longitudinal study of patients. Population-based and outpatient clinic. Eight hundred forty-three healthy children from the COPENHAGEN Puberty Study and 25 girls evaluated for central precocious puberty (CPP). Clinical pubertal staging, including serum and urinary gonadotropin levels. Urinary gonadotropins increased with advancing age and pubertal development and were detectable in FMV urine before physical signs of puberty. FMV urinary LH correlated strongly with basal (r = 0.871, P 5 IU/L). Urinary concentrations of LH decreased after 3 months of GnRH treatment to levels below +2 SDs. Urinary gonadotropin levels increased before the onset of puberty and were elevated in girls with CPP. We suggest urinary LH as an alternative noninvasive method to improve diagnosing and therapeutic management of children with disordered puberty. Copyright © 2017 Endocrine Society

First evidence of the role of zonal flows for the L-H transition at marginal input power in the EAST tokamak

DEFF Research Database (Denmark)

Xu, G. S.; Wan, B. N.; Wang, H. Q.

2011-01-01

A quasiperiodic Er oscillation at a frequency of transition, has been observed for the first time in the EAST tokamak, using two...... toroidally separated reciprocating probes. Just prior to the L-H transition, the Er oscillation often evolves into intermittent negative Er spikes. The low-frequency Er oscillation, as well as the Er spikes, is strongly correlated with the turbulence-driven Reynolds stress, thus providing first evidence...... of the role of the zonal flows in the L-H transition at marginal input power. These new findings not only shed light on the underlying physics mechanism for the L-H transition, but also have significant implications for ITER operations close to the L-H transition threshold power....

Dynamics of L-H transition and I-phase in EAST

DEFF Research Database (Denmark)

Xu, G. S.; Wang, H. Q.; Xu, M.

2014-01-01

The turbulence and flows at the plasma edge during the L-I-H, L-I-L and single-step L-H transitions have been measured directly using two reciprocating Langmuir probe systems at the outer midplane with several newly designed probe arrays in the EAST superconducting tokamak. The E × B velocity, tu...

Solid propellant ignition motors for LH_2/LOX rocket engine system

OpenAIRE

ARAKI, Tetsuo; AKIBA, Ryojiro; HASHIMOTO, Yasunari; AIHARA, Kenji; TOMITA, Etsu; YASUDA, Seiichi; 荒木, 哲夫; 秋葉, 鐐二郎; 橋本, 保成; 相原, 賢二; 富田, 悦; 安田, 誠一

1983-01-01

Solid propellant ignition motors are used in the series of experiments of the 10 ton LH_2/LOX engine featured by the channel wall thrust chamber, This paper presents design specification, experiments and results obtained by actual applications of those ignition motors.

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

Science.gov (United States)

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

1991-02-01

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

Population and coherence dynamics in light harvesting complex II (LH2).

Science.gov (United States)

Yeh, Shu-Hao; Zhu, Jing; Kais, Sabre

2012-08-28

The electronic excitation population and coherence dynamics in the chromophores of the photosynthetic light harvesting complex 2 (LH2) B850 ring from purple bacteria (Rhodopseudomonas acidophila) have been studied theoretically at both physiological and cryogenic temperatures. Similar to the well-studied Fenna-Matthews-Olson (FMO) protein, oscillations of the excitation population and coherence in the site basis are observed in LH2 by using a scaled hierarchical equation of motion approach. However, this oscillation time (300 fs) is much shorter compared to the FMO protein (650 fs) at cryogenic temperature. Both environment and high temperature are found to enhance the propagation speed of the exciton wave packet yet they shorten the coherence time and suppress the oscillation amplitude of coherence and the population. Our calculations show that a long-lived coherence between chromophore electronic excited states can exist in such a noisy biological environment.

X-Rays from the Location of the Double-humped Transient ASASSN-15lh

Science.gov (United States)

Margutti, R.; Metzger, B. D.; Chornock, R.; Milisavljevic, D.; Berger, E.; Blanchard, P. K.; Guidorzi, C.; Migliori, G.; Kamble, A.; Lunnan, R.; Nicholl, M.; Coppejans, D. L.; Dall'Osso, S.; Drout, M. R.; Perna, R.; Sbarufatti, B.

2017-02-01

We present the detection of persistent soft X-ray radiation with {L}x˜ {10}41-1042 erg s-1 at the location of the extremely luminous, double-humped transient ASASSN-15lh as revealed by Chandra and Swift. We interpret this finding in the context of observations from our multiwavelength campaign, which revealed the presence of weak narrow nebular emission features from the host-galaxy nucleus and clear differences with respect to superluminous supernova optical spectra. Significant UV flux variability on short timescales detected at the time of the rebrightening disfavors the shock interaction scenario as the source of energy powering the long-lived UV emission, while deep radio limits exclude the presence of relativistic jets propagating into a low-density environment. We propose a model where the extreme luminosity and double-peaked temporal structure of ASASSN-15lh is powered by a central source of ionizing radiation that produces a sudden change in the ejecta opacity at later times. As a result, UV radiation can more easily escape, producing the second bump in the light curve. We discuss different interpretations for the intrinsic nature of the ionizing source. We conclude that, if the X-ray source is physically associated with the optical-UV transient, then ASASSN-15lh most likely represents the tidal disruption of a main-sequence star by the most massive spinning black hole detected to date. In this case, ASASSN-15lh and similar events discovered in the future would constitute the most direct probes of very massive, dormant, spinning, supermassive black holes in galaxies. Future monitoring of the X-rays may allow us to distinguish between the supernova hypothesis and the hypothesis of a tidal disruption event.

Mathematical modeling of gonadotropin-releasing hormone signaling.

Science.gov (United States)

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

2017-07-05

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

COMMERCIAL SNF ACCIDENT RELEASE FRACTIONS

Energy Technology Data Exchange (ETDEWEB)

S.O. Bader

1999-10-18

The purpose of this design analysis is to specify and document the total and respirable fractions for radioactive materials that are released from an accident event at the Monitored Geologic Repository (MGR) involving commercial spent nuclear fuel (CSNF) in a dry environment. The total and respirable release fractions will be used to support the preclosure licensing basis for the MGR. The total release fraction is defined as the fraction of total CSNF assembly inventory, typically expressed as an activity inventory (e.g., curies), of a given radionuclide that is released to the environment from a waste form. The radionuclides are released from the inside of breached fuel rods (or pins) and from the detachment of radioactive material (crud) from the outside surfaces of fuel rods and other components of fuel assemblies. The total release fraction accounts for several mechanisms that tend to retain, retard, or diminish the amount of radionuclides that are available for transport to dose receptors or otherwise can be shown to reduce exposure of receptors to radiological releases. The total release fraction includes a fraction of airborne material that is respirable and could result in inhalation doses. This subset of the total release fraction is referred to as the respirable release fraction. Potential accidents may involve waste forms that are characterized as either bare (unconfined) fuel assemblies or confined fuel assemblies. The confined CSNF assemblies at the MGR are contained in shipping casks, canisters, or disposal containers (waste packages). In contrast to the bare fuel assemblies, the container that confines the fuel assemblies has the potential of providing an additional barrier for diminishing the total release fraction should the fuel rod cladding breach during an accident. However, this analysis will not take credit for this additional bamer and will establish only the total release fractions for bare unconfined CSNF assemblies, which may however be

COMMERCIAL SNF ACCIDENT RELEASE FRACTIONS

International Nuclear Information System (INIS)

S.O. Bader

1999-01-01

The purpose of this design analysis is to specify and document the total and respirable fractions for radioactive materials that are released from an accident event at the Monitored Geologic Repository (MGR) involving commercial spent nuclear fuel (CSNF) in a dry environment. The total and respirable release fractions will be used to support the preclosure licensing basis for the MGR. The total release fraction is defined as the fraction of total CSNF assembly inventory, typically expressed as an activity inventory (e.g., curies), of a given radionuclide that is released to the environment from a waste form. The radionuclides are released from the inside of breached fuel rods (or pins) and from the detachment of radioactive material (crud) from the outside surfaces of fuel rods and other components of fuel assemblies. The total release fraction accounts for several mechanisms that tend to retain, retard, or diminish the amount of radionuclides that are available for transport to dose receptors or otherwise can be shown to reduce exposure of receptors to radiological releases. The total release fraction includes a fraction of airborne material that is respirable and could result in inhalation doses. This subset of the total release fraction is referred to as the respirable release fraction. Potential accidents may involve waste forms that are characterized as either bare (unconfined) fuel assemblies or confined fuel assemblies. The confined CSNF assemblies at the MGR are contained in shipping casks, canisters, or disposal containers (waste packages). In contrast to the bare fuel assemblies, the container that confines the fuel assemblies has the potential of providing an additional barrier for diminishing the total release fraction should the fuel rod cladding breach during an accident. However, this analysis will not take credit for this additional bamer and will establish only the total release fractions for bare unconfined CSNF assemblies, which may however be

Study of fuel systems for LH2-fueled subsonic transport aircraft, volume 1

Science.gov (United States)

Brewer, G. D.; Morris, R. E.; Davis, G. W.; Versaw, E. F.; Cunnington, G. R., Jr.; Riple, J. C.; Baerst, C. F.; Garmong, G.

1978-01-01

Several engine concepts examined to determine a preferred design which most effectively exploits the characteristics of hydrogen fuel in aircraft tanks received major emphasis. Many candidate designs of tank structure and cryogenic insulation systems were evaluated. Designs of all major elements of the aircraft fuel system including pumps, lines, valves, regulators, and heat exchangers received attention. Selected designs of boost pumps to be mounted in the LH2 tanks, and of a high pressure pump to be mounted on the engine were defined. A final design of LH2-fueled transport aircraft was established which incorporates a preferred design of fuel system. That aircraft was then compared with a conventionally fueled counterpart designed to equivalent technology standards.

Effects of Calcium Ions on the Thermostability and Spectroscopic Properties of the LH1-RC Complex from a New Thermophilic Purple Bacterium Allochromatium tepidum.

Science.gov (United States)

Kimura, Yukihiro; Lyu, Shuwen; Okoshi, Akira; Okazaki, Koudai; Nakamura, Natsuki; Ohashi, Akira; Ohno, Takashi; Kobayashi, Manami; Imanishi, Michie; Takaichi, Shinichi; Madigan, Michael T; Wang-Otomo, Zheng-Yu

2017-05-18

The light harvesting-reaction center (LH1-RC) complex from a new thermophilic purple sulfur bacterium Allochromatium (Alc.) tepidum was isolated and characterized by spectroscopic and thermodynamic analyses. The purified Alc. tepidum LH1-RC complex showed a high thermostability comparable to that of another thermophilic purple sulfur bacterium Thermochromatium tepidum, and spectroscopic characteristics similar to those of a mesophilic bacterium Alc. vinosum. Approximately 4-5 Ca 2+ per LH1-RC were detected by inductively coupled plasma atomic emission spectroscopy and isothermal titration calorimetry. Upon removal of Ca 2+ , the denaturing temperature of the Alc. tepidum LH1-RC complex dropped accompanied by a blue-shift of the LH1 Q y absorption band. The effect of Ca 2+ was also observed in the resonance Raman shift of the C3-acetyl νC═O band of bacteriochlorophyll-a, indicating changes in the hydrogen-bonding interactions between the pigment and LH1 polypeptides. Thermodynamic parameters for the Ca 2+ -binding to the Alc. tepidum LH1-RC complex indicated that this reaction is predominantly driven by the largely favorable electrostatic interactions that counteract the unfavorable negative entropy change. Our data support a hypothesis that Alc. tepidum may be a transitional organism between mesophilic and thermophilic purple bacteria and that Ca 2+ is one of the major keys to the thermostability of LH1-RC complexes in purple bacteria.

Distinct responses of human granulosa lutein cells after hCG or LH stimulation in a spheroidal cell culture system.

Science.gov (United States)

Becker, Julia; Walz, Andrea; Daube, Stefanie; Keck, Christoph; Pietrowski, Detlef

2007-10-01

The growth and development of the corpus luteum (CL) is regulated by gonadotropic hormones. It is formed by granulosa cells (GCs), theca cells, and endothelial cells, and is the primary source of circulating progesterone. During early pregnancy only human chorionic gonadotropin (hCG) but not luteinizing hormone (LH) extends the life span of the CL, although hCG and LH interact with the same receptor and have similar actions on the CL. In this study a recently by our group established spheroidal GC culture assay served as a model of CL development on which we compared the actions of the gonadotropic hormones LH and hCG. To find out which signal pathways take part in the hormonal regulation of GC we stimulated GC-spheroids with modulators of protein kinases A and C dependent signaling cascades and determined their impact on sprout forming activity in GC. Our results indicate that PKA-dependent signaling pathways play a major role in mediating the hormonal-induced signaling cascades leading to sprouting in GC. Furthermore, this study strongly indicates that the different effects of hCG and LH in the maintenance of the CL may be reasoned in different signal transduction pathways triggered by hCG or LH. (c) 2007 Wiley-Liss, Inc.

Characterization of LH induced current carrying fast electrons in JET

Energy Technology Data Exchange (ETDEWEB)

Ramponi, G.; Airoldi, A. [Consiglio Nazionale delle Ricerche, Milan (Italy). Lab. di Fisica del Plasma; Bartlett, D.; Brusati, M.; Froissard, P.; Gormezano, C.; Rimini, F.; Silva, R.P. da; Tanzi, C.P. [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking

1992-12-31

Lower Hybrid Current Drive (LHCD) experiments have recently been made at JET by coupling up to 2.4 MW of RF power at 3.7 GHz, with a power spectrum centered at n{sub ||} = 1.8 {+-} 0.2 corresponding to a resonating electron energy of about 100 keV via Electron Landau Damping. The Current Drive (CD) efficiency has been observed to increase when LH and ICRH power are applied simultaneously to the plasma, suggesting that a part of the fast magnetosonic wave is absorbed on the LH-generated fast electrons. An important problem of CD experiments in tokamaks is the determination of the radial distribution of the driven current and the characterization in the momentum space of the current carrying fast electrons by using appropriate diagnostic tools. For this purpose, a combined analysis of the Electron Cyclotron Emission (ECE) and of the Fast Electron Bremsstrahlung (FEB) measurements has been made, allowing the relevant parameters of the suprathermal electrons to be estimated. (author) 5 refs., 5 figs., 2 tabs.

Characterization of LH induced current carrying fast electrons in JET

International Nuclear Information System (INIS)

Ramponi, G.; Airoldi, A.; Bartlett, D.; Brusati, M.; Froissard, P.; Gormezano, C.; Rimini, F.; Silva, R.P. da; Tanzi, C.P.

1992-01-01

Lower Hybrid Current Drive (LHCD) experiments have recently been made at JET by coupling up to 2.4 MW of RF power at 3.7 GHz, with a power spectrum centered at n || = 1.8 ± 0.2 corresponding to a resonating electron energy of about 100 keV via Electron Landau Damping. The Current Drive (CD) efficiency has been observed to increase when LH and ICRH power are applied simultaneously to the plasma, suggesting that a part of the fast magnetosonic wave is absorbed on the LH-generated fast electrons. An important problem of CD experiments in tokamaks is the determination of the radial distribution of the driven current and the characterization in the momentum space of the current carrying fast electrons by using appropriate diagnostic tools. For this purpose, a combined analysis of the Electron Cyclotron Emission (ECE) and of the Fast Electron Bremsstrahlung (FEB) measurements has been made, allowing the relevant parameters of the suprathermal electrons to be estimated. (author) 5 refs., 5 figs., 2 tabs

The origin of the split B800 absorption peak in the LH2 complexes from Allochromatium vinosum.

Science.gov (United States)

Löhner, Alexander; Carey, Anne-Marie; Hacking, Kirsty; Picken, Nichola; Kelly, Sharon; Cogdell, Richard; Köhler, Jürgen

2015-01-01

The absorption spectrum of the high-light peripheral light-harvesting (LH) complex from the photosynthetic purple bacterium Allochromatium vinosum features two strong absorptions around 800 and 850 nm. For the LH2 complexes from the species Rhodopseudomonas acidophila and Rhodospirillum molischianum, where high-resolution X-ray structures are available, similar bands have been observed and were assigned to two pigment pools of BChl a molecules that are arranged in two concentric rings (B800 and B850) with nine (acidophila) or eight (molischianum) repeat units, respectively. However, for the high-light peripheral LH complex from Alc. vinosum, the intruiging feature is that the B800 band is split into two components. We have studied this pigment-protein complex by ensemble CD spectroscopy and polarisation-resolved single-molecule spectroscopy. Assuming that the high-light peripheral LH complex in Alc. vinosum is constructed on the same modular principle as described for LH2 from Rps. acidophila and Rsp. molischianum, we used those repeat units as a starting point for simulating the spectra. We find the best agreement between simulation and experiment for a ring-like oligomer of 12 repeat units, where the mutual arrangement of the B800 and B850 rings resembles those from Rsp. molischianum. The splitting of the B800 band can be reproduced if both an excitonic coupling between dimers of B800 molecules and their interaction with the B850 manifold are taken into account. Such dimers predict an interesting apoprotein organisation as discussed below.

Clinical significance of changes of plasma leptin and serum T, E2, FSH, LH, PRL levels in patients with polycystic ovary syndrome (PCOS)

International Nuclear Information System (INIS)

Yang Wen; Wang Ying

2010-01-01

Objective: To explore the clinical significance of changes of plasma leptin and serum T, E 2 , FSH, LH, PRL levels in patients with polycystic ovary syndrome(PCOS). Methods: Plasma leptin (with RIA), serum T, E 2 , FSH, LH, PRL (with ECLIA) levels were detected in 31 patients with polycystic ovary syndrome(PCOS) as well as in 35 controls. Results: The plasma leptin and serum T, LH, PRL levels in the patients with PCOS were significantly higher than those in controls (P 2 , FSH levels were not significantly different from those in controls (P>0.05). Plasma leptin levels were positively correlated with those of serum T, LH, PRL (r=0.5784, 0.5411, 0.6082, P<0.01). Conclusion: Development of PCOS was closely related to the plasma leptin and serum T, LH, PRL levels. (authors)

Receptor-targeted therapy of human experimental urinary bladder cancers with cytotoxic LH-RH analog AN-152 [AEZS- 108].

Science.gov (United States)

Szepeshazi, Karoly; Schally, Andrew V; Keller, Gunhild; Block, Norman L; Benten, Daniel; Halmos, Gabor; Szalontay, Luca; Vidaurre, Irving; Jaszberenyi, Miklos; Rick, Ferenc G

2012-07-01

Many bladder cancers progress to invasion with poor prognosis; new therapeutic methods are needed. We developed a cytotoxic LH-RH analog, AN-152 (AEZS-108) containing doxorubicin (DOX), for targeted therapy of cancers expressing LHRH receptors. We investigated the expression of LH-RH receptors in clinical bladder cancers and in HT-1376, J82, RT-4 and HT-1197 human bladder cancer lines. The effect of analog, AN-152, on growth of these tumor lines xenografted into nude mice was analyzed. Using molecular and functional assays, we also evaluated the differences between the effects of AN-152, and DOX alone. We demonstrated the expression of LH-RH receptors on 18 clinical bladder cancers by immunohistochemistry and on four human urinary bladder cancer lines HT-1376, J82, RT-4 and HT-1197 by Western blotting and binding assays. AN-152 powerfully inhibited growth of these bladder cancers in nude mice. AN-152 exerted greater effects than DOX and was less toxic. DOX activated strong multidrug resistance mechanisms in RT-4 and HT-1197 cancers, while AN-152 had no or less such effect. PCR assays and in vitro studies revealed differences in the action of AN-152 and DOX on the expression of genes involved in apoptosis. These results suggest that targeted cytotoxic LH-RH analog, AN-152 (AEZS- 108), should be examined for treatment of patients with LH-RH receptor positive invasive bladder cancers.

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

Science.gov (United States)

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

2011-01-01

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

A transduced living hyaline cartilage graft releasing transgenic stromal cell-derived factor-1 inducing endogenous stem cell homing in vivo.

Science.gov (United States)

Zhang, Feng; Leong, Wenyan; Su, Kai; Fang, Yu; Wang, Dong-An

2013-05-01

Stromal cell-derived factor-1 (SDF-1), also known as a homing factor, is a potent chemokine that activates and directs mobilization, migration, and retention of certain cell species via systemic circulation. The responding homing cells largely consist of activated stem cells, so that, in case of tissue lesions, such SDF-1-induced cell migration may execute recruitment of endogenous stem cells to perform autoreparation and compensatory regeneration in situ. In this study, a recombinant adenoviral vector carrying SDF-1 transgene was constructed and applied to transduce a novel scaffold-free living hyaline cartilage graft (SDF-t-LhCG). As an engineered transgenic living tissue, SDF-t-LhCG is capable of continuously producing and releasing SDF-1 in vitro and in vivo. The in vitro trials were examined with ELISA, while the in vivo trials were subsequently performed via a subcutaneous implantation of SDF-t-LhCG in a nude mouse model, followed by series of biochemical and biological analyses. The results indicate that transgenic SDF-1 enhanced the presence of this chemokine in mouse's circulation system; in consequence, SDF-1-induced activation and recruitment of endogenous stem cells were also augmented in both peripheral blood and SDF-t-LhCG implant per se. These results were obtained via flow cytometry analyses on mouse blood samples and implanted SDF-t-LhCG samples, indicating an upregulation of the CXCR4(+)(SDF-1 receptor) cell population, accompanied by upregulation of the CD34(+), CD44(+), and Sca-1(+) cell populations as well as a downregulation of the CD11b(+) cell population. With the supply of SDF-1-recruited endogenous stem cells, enhanced chondrogenesis was observed in SDF-t-LhCG implants in situ.

LH2 three-phase pump control circuit description

International Nuclear Information System (INIS)

Pierce, W.

1977-05-01

A brief description and circuit drawings are given for a pump control system. The pump is used to circulate liquid hydrogen through the cell and heat exchanger of an LH 2 target. The pump is powered by three-phase 60 cycle power, and the control unit is powered from a positive and negative 24 V dc supply available in the NIM Bin. The control unit is packaged in a double-width NIM module. Drawings are given for the pump speed indicator, function generator, and power supply

Engineering of a calcium-ion binding site into the RC-LH1-PufX complex of Rhodobacter sphaeroides to enable ion-dependent spectral red-shifting.

Science.gov (United States)

Swainsbury, David J K; Martin, Elizabeth C; Vasilev, Cvetelin; Parkes-Loach, Pamela S; Loach, Paul A; Neil Hunter, C

2017-11-01

The reaction centre-light harvesting 1 (RC-LH1) complex of Thermochromatium (Tch.) tepidum has a unique calcium-ion binding site that enhances thermal stability and red-shifts the absorption of LH1 from 880nm to 915nm in the presence of calcium-ions. The LH1 antenna of mesophilic species of phototrophic bacteria such as Rhodobacter (Rba.) sphaeroides does not possess such properties. We have engineered calcium-ion binding into the LH1 antenna of Rba. sphaeroides by progressively modifying the native LH1 polypeptides with sequences from Tch. tepidum. We show that acquisition of the C-terminal domains from LH1 α and β of Tch. tepidum is sufficient to activate calcium-ion binding and the extent of red-shifting increases with the proportion of Tch. tepidum sequence incorporated. However, full exchange of the LH1 polypeptides with those of Tch. tepidum results in misassembled core complexes. Isolated α and β polypeptides from our most successful mutant were reconstituted in vitro with BChl a to form an LH1-type complex, which was stabilised 3-fold by calcium-ions. Additionally, carotenoid specificity was changed from spheroidene found in Rba. sphaeroides to spirilloxanthin found in Tch. tepidum, with the latter enhancing in vitro formation of LH1. These data show that the C-terminal LH1 α/β domains of Tch. tepidum behave autonomously, and are able to transmit calcium-ion induced conformational changes to BChls bound to the rest of a foreign antenna complex. Thus, elements of foreign antenna complexes, such as calcium-ion binding and blue/red switching of absorption, can be ported into Rhodobacter sphaeroides using careful design processes. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

Reusable LH2 tank technology demonstration through ground test

Science.gov (United States)

Bianca, C.; Greenberg, H. S.; Johnson, S. E.

1995-01-01

The paper presents the project plan to demonstrate, by March 1997, the reusability of an integrated composite LH2 tank structure, cryogenic insulation, and thermal protection system (TPS). The plan includes establishment of design requirements and a comprehensive trade study to select the most suitable Reusable Hydrogen Composite Tank system (RHCTS) within the most suitable of 4 candidate structural configurations. The 4 vehicles are winged body with the capability to deliver 25,000 lbs of payload to a circular 220 nm, 51.6 degree inclined orbit (also 40,000 lbs to a 28.5 inclined 150 nm orbit). A prototype design of the selected RHCTS is established to identify the construction, fabrication, and stress simulation and test requirements necessary in an 8 foot diameter tank structure/insulation/TPS test article. A comprehensive development test program supports the 8 foot test article development and involves the composite tank itself, cryogenic insulation, and integrated tank/insulation/TPS designs. The 8 foot diameter tank will contain the integrated cryogenic insulation and TPS designs resulting from this development and that of the concurrent lightweight durable TPS program. Tank ground testing will include 330 cycles of LH2 filling, pressurization, body loading, depressurization, draining, and entry heating.

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

NARCIS (Netherlands)

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

2009-01-01

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

Commercial SNF Accident Release Fractions

Energy Technology Data Exchange (ETDEWEB)

J. Schulz

2004-11-05

The purpose of this analysis is to specify and document the total and respirable fractions for radioactive materials that could be potentially released from an accident at the repository involving commercial spent nuclear fuel (SNF) in a dry environment. The total and respirable release fractions are used to support the preclosure licensing basis for the repository. The total release fraction is defined as the fraction of total commercial SNF assembly inventory, typically expressed as an activity inventory (e.g., curies), of a given radionuclide that is released to the environment from a waste form. Radionuclides are released from the inside of breached fuel rods (or pins) and from the detachment of radioactive material (crud) from the outside surfaces of fuel rods and other components of fuel assemblies. The total release fraction accounts for several mechanisms that tend to retain, retard, or diminish the amount of radionuclides that are available for transport to dose receptors or otherwise can be shown to reduce exposure of receptors to radiological releases. The total release fraction includes a fraction of airborne material that is respirable and could result in inhalation doses; this subset of the total release fraction is referred to as the respirable release fraction. Accidents may involve waste forms characterized as: (1) bare unconfined intact fuel assemblies, (2) confined intact fuel assemblies, or (3) canistered failed commercial SNF. Confined intact commercial SNF assemblies at the repository are contained in shipping casks, canisters, or waste packages. Four categories of failed commercial SNF are identified: (1) mechanically and cladding-penetration damaged commercial SNF, (2) consolidated/reconstituted assemblies, (3) fuel rods, pieces, and debris, and (4) nonfuel components. It is assumed that failed commercial SNF is placed into waste packages with a mesh screen at each end (CRWMS M&O 1999). In contrast to bare unconfined fuel assemblies, the

Commercial SNF Accident Release Fractions

International Nuclear Information System (INIS)

Schulz, J.

2004-01-01

The purpose of this analysis is to specify and document the total and respirable fractions for radioactive materials that could be potentially released from an accident at the repository involving commercial spent nuclear fuel (SNF) in a dry environment. The total and respirable release fractions are used to support the preclosure licensing basis for the repository. The total release fraction is defined as the fraction of total commercial SNF assembly inventory, typically expressed as an activity inventory (e.g., curies), of a given radionuclide that is released to the environment from a waste form. Radionuclides are released from the inside of breached fuel rods (or pins) and from the detachment of radioactive material (crud) from the outside surfaces of fuel rods and other components of fuel assemblies. The total release fraction accounts for several mechanisms that tend to retain, retard, or diminish the amount of radionuclides that are available for transport to dose receptors or otherwise can be shown to reduce exposure of receptors to radiological releases. The total release fraction includes a fraction of airborne material that is respirable and could result in inhalation doses; this subset of the total release fraction is referred to as the respirable release fraction. Accidents may involve waste forms characterized as: (1) bare unconfined intact fuel assemblies, (2) confined intact fuel assemblies, or (3) canistered failed commercial SNF. Confined intact commercial SNF assemblies at the repository are contained in shipping casks, canisters, or waste packages. Four categories of failed commercial SNF are identified: (1) mechanically and cladding-penetration damaged commercial SNF, (2) consolidated/reconstituted assemblies, (3) fuel rods, pieces, and debris, and (4) nonfuel components. It is assumed that failed commercial SNF is placed into waste packages with a mesh screen at each end (CRWMS M andO 1999). In contrast to bare unconfined fuel assemblies, the

Power injection performance of the LH antenna tipped with carbon grills in JT-60U

International Nuclear Information System (INIS)

Ishii, Kazuhiro; Seki, Masami; Shinozaki, Shinichi; Hasegawa, Koichi; Hiranai, Shinichi; Suzuki, Sadaaki; Sato, Fumiaki; Moriyama, Shinichi; Yokokura, Kenji

2007-07-01

The lower hybrid (LH) antenna in JT-60U has interaction with plasmas because it should be close to them in order to inject effectively radio frequency (RF) power into them. As a result, it has been a serious problem that the antenna mouth made of stainless steels was damaged due to excessive heat loads of plasmas and RF breakdowns. To solve the problem, a heat-resistant LH antenna was developed tipping carbon grills with fairly high heat resistance on the antenna mouth, and therefore reduction in damages on the mouth was expected. Power injection into plasmas was firstly performed with the heat-resistant antenna. RF conditioning was done carefully in the initial phase because RF breakdown due to outgassing from the grills might be occurred. After sufficient degassing was done through RF conditioning, RF power of about 1.6 MW x 10 sec injection was successfully injected to plasmas. Moreover it was demonstrated that it had comparably high plasma current drive capability (about 1.6 x 10 19 A/W/m 2 ), required as a current drive LH antenna. (author)

Flexibility and size heterogeneity of the LH1 light harvesting complex revealed by atomic force microscopy - Functional significance for bacterial photosynthesis

NARCIS (Netherlands)

Bahatyrova, S.; Frese, R.N.; van der Werf, K.O.; Otto, C.; Hunter, C.N.; Olsen, J.D.

2004-01-01

Previous electron microscopic studies of bacterial RC-LH1 complexes demonstrated both circular and elliptical conformations of the LH1 ring, and this implied flexibility has been suggested to allow passage of quinol from the Q

The Use of rLH, HMG and hCG in Controlled Ovarian Stimulation for Assisted Reproductive Technologies

Science.gov (United States)

2012-11-21

responders involves the use of the microdose flare protocol. This protocol avoids the profound suppression of endogenous LH and FSH in the early...follicular phase normally achieved with long luteal downregulation protocols. Scott and Novat’s initial investigation of the microdose flare found it to...protocol increases live birth rates (113-116). One RCT did not show any benefit to adding either rLH or low-dose rHCG to a microdose flare protocol for

Effect of medium type and luteinizing hormone (LH) on in vitro ...

African Journals Online (AJOL)

Maturation rate was assessed by evaluation of degree of cumulus cells expansion and meiotic development. Results indicate that recovery rate ranged between 2.4 to 2.8. Moreover, results revealed that maturation rate, telophase and metaphase II stages were higher for oocytes matured in TCM-199 + LH than oocytes ...

Measurement Differences Between Two Immunoassay Systems for LH and FSH: A Comparison of Roche Cobas e601 vs. Abbott Architect i2000sr.

Science.gov (United States)

Yin, Lianli; Tang, Yinghua; Chen, Xiang; Sun, Yifan

2018-03-01

Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) regulate the growth and reproductive activity of gonadal tissue and determine the concentration of LH is essential for the prediction of ovulation. Collectively, FSH and LH are important measurements to ascertain the causes of infertility as well as diagnosing disorders such as polycystic ovary syndrome and pituitary and gonadal dysfunction. This study compares the correlation between LH and FSH measurements during examination with two different systems, Architect i2000sr (Abbott Laboratories; Lake Bluff, IL, USA) and Cobas e601 (Roche; Geneva, Switzerland), and assesses the differences between these systems. Serum analysis was performed for 95 patients using both the Cobas e601 and Architect i2000sr systems. The method used to compare the systems was Passing-Bablok regression analysis with a Bland-Altman agreement plot. Inter-rater agreement was analyzed using a concordance correlation coefficient. Architect i2000sr and Cobas e601 have strong correlations in their LH and FSH results. However, the Bland-Altman plot shows that LH and FSH measurements in Cobas e601 are about 1.31 times and 1.26 times higher than those in Architect i2000sr, respectively. Passing-Bablok regression analysis also shows significant proportional deviation between them. The difference between the test results for LH and FSH in Cobas e601 and Architect i2000sr indicate that the results from one system cannot be directly used to evaluate the other system.

Factors that predict a positive response on gonadotropin-releasing hormone stimulation test for diagnosing central precocious puberty in girls

Directory of Open Access Journals (Sweden)

Junghwan Suh

2013-12-01

Full Text Available PurposeThe rapid increase in the incidence of precocious puberty in Korea has clinical and social significance. Gonadotropin-releasing hormone (GnRH stimulation test is required to diagnose central precocious puberty (CPP, however this test is expensive and time-consuming. This study aimed to identify factors that can predict a positive response to the GnRH stimulation test.MethodsClinical and laboratory parameters, including basal serum luteinizing hormone (LH, follicle-stimulating hormone (FSH, and estradiol (E2, were measured in 540 girls with clinical signs of CPP.ResultsTwo hundred twenty-nine of 540 girls with suspected CPP had a peak serum LH level higher than 5 IU/L (the CPP group. The CPP group had advanced bone age (P<0.001, accelerated yearly growth rate (P<0.001, increased basal levels of LH (P=0.02, FSH (P<0.001, E2 (P=0.001, and insulin-like growth factor-I levels (P<0.001 compared to the non-CPP group. In contrast, body weight (P<0.001 and body mass index (P<0.001 were lower in the CPP group. Although basal LH was significantly elevated in the CPP group compared to the non-CPP group, there was considerable overlap between the 2 groups. Cutoff values of basal LH (0.22 IU/L detected CPP with 87.8% sensitivity and 20.9% specificity.ConclusionNo single parameter can predict a positive response on the GnRH stimulation test with both high sensitivity and specificity. Therefore, multiple factors should be considered in evaluation of sexual precocity when deciding the timing of the GnRH stimulation test.

Synchrotron small-angle x-ray scattering investigation on integral membrane protein light-harvesting complex LH2 from photosynthetic bacterium rhodopseudomonas acidophila

International Nuclear Information System (INIS)

Du Luchao; Weng Yuxiang; Hong Xinguo; Xian Dingchang; Kobayashi Katsumi

2006-01-01

Structures of membrane protein in solution are different from that in crystal phase. We present the primary results of small angle x-ray scattering (SAXS) resolved topological structures of a light harvesting antenna membrane protein complex LH2 from photosynthetic bacteria Rhodopseudomonas acidophila in detergent solution for the first time. Our results show that the elliptical shape of the LH2 complex in solution clearly deviates from its circular structure in crystal phase determined by x-ray diffraction. This result provides an insight into the structure and function interplay in LH2. (authors)

Recombinant LH supplementation to recombinant FSH during the final days of controlled ovarian stimulation for in vitro fertilization. A multicentre, prospective, randomized, controlled trial

DEFF Research Database (Denmark)

Nyboeandersen, A.; Humaidan, P.; Fried, G.

2008-01-01

BACKGROUND: The purpose of this multicentre, multinational trial was to study whether rLH supplementation to recombinant FSH (rFSH) during the late follicular phase increased pregnancy rates. METHODS: After down-regulation with nafarelin, 526 women were randomized on Day 1 of stimulation to use...... either rFSH (Gonal-F) alone (n = 261) or to continue after Day 6 of stimulation with both rFSH (Gonal-F) and rLH (Luveris) (n = 265) from Day 6. The starting dose of rFSH was 150-225 IU/day according to age below or above 35 years. RESULTS: Ongoing pregnancy rate at week 10-12 was 28.7% after rFSH alone...... and 27.2% after rFSH + rLH. This showed no evidence of a difference. Administration of rLH significantly (Prates in patients with low LH levels (

Recombinant LH supplementation to recombinant FSH during the final days of controlled ovarian stimulation for in vitro fertilization. A multicentre, prospective, randomized, controlled trial

DEFF Research Database (Denmark)

Nyboeandersen, A; Al Humaidan, Peter Samir Heskjær; Fried, G

2008-01-01

BACKGROUND: The purpose of this multicentre, multinational trial was to study whether rLH supplementation to recombinant FSH (rFSH) during the late follicular phase increased pregnancy rates. METHODS: After down-regulation with nafarelin, 526 women were randomized on Day 1 of stimulation to use...... either rFSH (Gonal-F) alone (n = 261) or to continue after Day 6 of stimulation with both rFSH (Gonal-F) and rLH (Luveris) (n = 265) from Day 6. The starting dose of rFSH was 150-225 IU/day according to age below or above 35 years. RESULTS: Ongoing pregnancy rate at week 10-12 was 28.7% after rFSH alone...... and 27.2% after rFSH + rLH. This showed no evidence of a difference. Administration of rLH significantly (PLH. Ongoing pregnancy rates in patients with low LH levels (

Preparatory separation of the silymarin flavonolignans by Sephadex LH-20 gel

Czech Academy of Sciences Publication Activity Database

Křenek, Karel; Marhol, Petr; Peikerová, Žaneta; Křen, Vladimír; Biedermann, David

2014-01-01

Roč. 65, č. 1 (2014), s. 115-120 ISSN 0963-9969 R&D Projects: GA ČR(CZ) GAP301/11/0662; GA MŠk LH13097; GA MŠk(CZ) LD13041 Institutional support: RVO:61388971 Keywords : silymarin * silybin * nutraceutical Subject RIV: CE - Biochemistry Impact factor: 2.818, year: 2014

GnRH Agonist Trigger and LH Activity Luteal Phase Support versus hCG Trigger and Conventional Luteal Phase Support in Fresh Embryo Transfer IVF/ICSI Cycles—A Systematic PRISMA Review and Meta-analysis

Directory of Open Access Journals (Sweden)

Thor Haahr

2017-06-01

Full Text Available IntroductionThe use of GnRH agonist (GnRHa for final oocyte maturation trigger in oocyte donation and elective frozen embryo transfer cycles is well established due to lower ovarian hyperstimulation syndrome (OHSS rates as compared to hCG trigger. A recent Cochrane meta-analysis concluded that GnRHa trigger was associated with reduced live birth rates (LBRs in fresh autologous IVF cycles compared to hCG trigger. However, the evidence is not unequivocal, and recent trials have found encouraging reproductive outcomes among couples undergoing GnRHa trigger and individualized luteal LH activity support. Thus, the aim was to compare GnRHa trigger followed by luteal LH activity support with hCG trigger in IVF patients undergoing fresh embryo transfer.Material and methodsWe conducted a systematic review and meta-analysis of randomized trials published until December 14, 2016. The population was infertile patients submitted to IVF/ICSI cycles with GnRH antagonist cotreatment who underwent fresh embryo transfer. The intervention was GnRHa trigger followed by LH activity luteal phase support (LPS. The comparator was hCG trigger followed by a standard LPS. The critical outcome measures were LBR and OHSS rate. The secondary outcome measures were number of oocytes retrieved, clinical and ongoing pregnancy rates, and miscarriage rates.ResultsA total of five studies met the selection criteria comprising a total of 859 patients. The LBR was not significantly different between the GnRHa and hCG trigger groups (OR 0.84, 95% CI 0.62, 1.14. OHSS was reported in a total of 4/413 cases in the GnRHa group compared to 7/413 in the hCG group (OR 0.48, 95% CI 0.15, 1.60. We observed a slight, but non-significant increase in miscarriage rate in the GnRHa triggered group compared to the hCG group (OR 1.85; 95% CI 0.97, 3.54.ConclusionGnRHa trigger with LH activity LPS resulted in comparable LBRs compared to hCG trigger. The most recent trials reported LBRs close to unity

EC + LH current drive efficiency in the presence of an internal transport barrier

International Nuclear Information System (INIS)

Rosa, P.R. da S; Ziebell, L.F.

2002-01-01

In this paper we study the effects of the presence of an internal transport barrier (ITB) on the current drive efficiency and power deposition profiles in the case of electron cyclotron waves interacting with an extended tail generated by lower hybrid (LH) waves. We study the subject by numerically solving the Fokker-Planck equation, with temperature and density profiles corrected along the time evolution at each collision time, based on the actual time-evolving electron distribution function. The results obtained show that the LH and electron cyclotron (EC) power absorption profiles and the current driven by the combined action of both types of waves are weakly dependent on the depth of the ITB, slightly more dependent on the level of magnetic turbulence and much more dependent on the level of EC wave power. (author)

Warm-ion drift Alfven turbulence and the L-H transition

International Nuclear Information System (INIS)

Scott, B.

1998-01-01

Computations of fluid drift turbulence treating ions and electrons on equal footing, including both temperatures, are conducted in a model toroidal geometry. The resulting 'ion mixing mode' turbulence bears features of both electron drift-Alfven and ion temperature gradient turbulence, and nonlinear sensitivity to the relative strengths of the density and temperature gradients provides a possible route to the bifurcation needed for the L-H transition. (author)

Production of anti-IgG antibodies in sheep for using in the radioimmunoassays of LH, FSH and prolactin

International Nuclear Information System (INIS)

Caso, R.; Perez, E.; Mosquera, M.; Arranz, C.

1996-01-01

In this work described the production of second antibodies in sheep against rabbit IgG for being used in radioimmunoassays for determination LH, FSH and Prolactin. There was made the comparison between the results obtained using the Kits-RIA produced by us and the commercial WHO Kits-RIA, using these antibodies. The results allowed us to use these antibodies for production Kits-RIA of LH, FSH and Prolactin

Thermal Design of Vapor Cooling of Flight Vehicle Structures Using LH2 Boil-Off

Science.gov (United States)

Wang, Xiao-Yen; Zoeckler, Joseph

2015-01-01

Using hydrogen boil-off vapor to cool the structure of a flight vehicle cryogenic upper stage can reduce heat loads to the stage and increase the usable propellant in the stage or extend the life of the stage. The hydrogen vapor can be used to absorb incoming heat as it increases in temperature before being vented overboard. In theory, the amount of heat leaking into the hydrogen tank from the structure will be reduced if the structure is cooled using the propellant boil-off vapor. However, the amount of boil-off vapor available to be used for cooling and the reduction in heat leak to the propellant tank are dependent to each other. The amount of heat leak reduction to the LH2 tank also depends on the total heat load on the stage and the vapor cooling configurations.

Developmental programming: Impact of fetal exposure to endocrine-disrupting chemicals on gonadotropin-releasing hormone and estrogen receptor mRNA in sheep hypothalamus

International Nuclear Information System (INIS)

Mahoney, Megan M.; Padmanabhan, Vasantha

2010-01-01

Bisphenol-A (BPA) and methoxychlor (MXC), two endocrine-disrupting chemicals (EDCs) with estrogenic and antiandrogenic effects, disrupt the reproductive system. BPA has profound effects on luteinizing hormone (LH) surge amplitude, and MXC has profound effects on on LH surge timing in sheep. The neural mechanisms involved in the differential disruption of the LH surge by these two EDCs remain to be elucidated. We tested the hypothesis that the differential effects of BPA and MXC on LH surge system involved changes in hypothalamic gonadotropin-releasing hormone (GnRH) and estrogen receptors (ESR), ESR1 and ESR2, mRNA expression. Pregnant sheep were given daily injections of cottonseed oil (controls), MXC, or BPA (5 mg/kg/day) from day 30 to 90 of gestation (term 147 d). Offspring from these animals were euthanized as adults, during the late follicular phase following synchronization of estrus with prostaglandin F 2α , just before the expected onset of preovulatory LH surge and changes in mRNA expression of hypothalamic GnRH, ESR1, and ESR2 quantified following in situ hybridization. GnRH mRNA expression was significantly lower in both groups of EDC-treated females compared to controls. ESR1 expression was increased in prenatal BPA- but not MXC-treated females in medial preoptic area relative to controls. In contrast, ESR2 expression was reduced in the medial preoptic area of both EDC-treated groups. Differences in expression of ESR1/ESR2 receptors may contribute to the differential effects of BPA and MXC on the LH surge system. These findings provide support that prenatal exposure to EDCs alters the neural developmental trajectory leading to long-term reproductive consequences in the adult female.

Developmental programming: impact of fetal exposure to endocrine-disrupting chemicals on gonadotropin-releasing hormone and estrogen receptor mRNA in sheep hypothalamus.

Science.gov (United States)

Mahoney, Megan M; Padmanabhan, Vasantha

2010-09-01

Bisphenol-A (BPA) and methoxychlor (MXC), two endocrine-disrupting chemicals (EDCs) with estrogenic and antiandrogenic effects, disrupt the reproductive system. BPA has profound effects on luteinizing hormone (LH) surge amplitude, and MXC has profound effects on on LH surge timing in sheep. The neural mechanisms involved in the differential disruption of the LH surge by these two EDCs remain to be elucidated. We tested the hypothesis that the differential effects of BPA and MXC on LH surge system involved changes in hypothalamic gonadotropin-releasing hormone (GnRH) and estrogen receptors (ESR), ESR1 and ESR2, mRNA expression. Pregnant sheep were given daily injections of cottonseed oil (controls), MXC, or BPA (5mg/kg/day) from day 30 to 90 of gestation (term 147d). Offspring from these animals were euthanized as adults, during the late follicular phase following synchronization of estrus with prostaglandin F(2alpha), just before the expected onset of preovulatory LH surge and changes in mRNA expression of hypothalamic GnRH, ESR1, and ESR2 quantified following in situ hybridization. GnRH mRNA expression was significantly lower in both groups of EDC-treated females compared to controls. ESR1 expression was increased in prenatal BPA- but not MXC-treated females in medial preoptic area relative to controls. In contrast, ESR2 expression was reduced in the medial preoptic area of both EDC-treated groups. Differences in expression of ESR1/ESR2 receptors may contribute to the differential effects of BPA and MXC on the LH surge system. These findings provide support that prenatal exposure to EDCs alters the neural developmental trajectory leading to long-term reproductive consequences in the adult female. 2010 Elsevier Inc. All rights reserved.

Standardization of the radioimmunoassay of 17{beta}-estradiol (E{sub 2}) plasmatic and his application to the study of secretion of E{sub 2} in normal women, during the menstrual cycle and after the infusion of the gonadotropin (LH/FSH/RH) release factor; Padronizacao do metodo de radioimunoensaio de 17{beta}-estradiol (E{sub 2}) plasmatico e sua aplicacao ao estudo da secrecao de E{sub 2} em mulheres normais, durante o ciclo menstrual e apos a infusao do fator liberador de gonadotrofinas (LH/FSH/RH)

Energy Technology Data Exchange (ETDEWEB)

Kiyan, Takeko Shimizu

1979-07-01

A radioimmunoassay method for measurement of plasma E{sub 2} was standardized utilizing a highly specific antisera against E{sub 2} [-6 (-0-carboxymethyl)-oxime] BSA without the need of previous chromatographic purification. The anti-E{sub 2} serum was highly specific, showing high affinity with affinity constants: K{sub 1}=1 .62x10{sup 12} M{sup -1} and K{sub 2} = 2.94x10{sup 11} M{sup -1}, calculated by Scatchard plot. The standard curve sensitivity was 2 pico grams. The method was specific and accurate, showing an intra-assay precision with a mean C.V. of 2.9%, with the inter-assay evaluation showing a mean C.V. of 5.0%. This method was employed to evaluate E{sub 2} secretion during the menstrual cycle in 6 normal females, as indicated below: Days: -14 to -10 (early follicular phase..64.68 pg/ml{+-}12.14; - 9 to - 1(late follicular phase).122.39 pg/ml {+-}33,54; Peak day 281.28 pg/ml {+-}66 ,59; + 1 to + 7(early luteal phase) 127.47 pg/ml {+-}24.88; + 8 to +14 (late luteal phase) 87.57 pg/ml{+-}37,56. The effect of the acute and prolonged infusion of LH/FSH-RH(synthetic hypothalamic LH and FSH releasing hormone) was evaluated in the follicular and luteal phase in some of the normal females. (author)

The Evolution of Utilizing Manual Throttles to Avoid Low LH2 NPSP at the SSME Inlet

Science.gov (United States)

Henfling, Rick

2011-01-01

Even before the first flight of the Space Shuttle, it was understood low liquid hydrogen (LH2) Net Positive Suction Pressure (NPSP) at the inlet to the Space Shuttle Main Engine (SSME) can have adverse effects on engine operation. A number of failures within both the External Tank (ET) and the Orbiter Main Propulsion System could result in a low LH2 NPSP condition. Operational workarounds were developed to take advantage of the onboard crew s ability to manually throttle down the SSMEs, which alleviated the low LH2 NPSP condition. A throttling down of the SSME resulted in an increase in NPSP, mainly due to the reduction in frictional flow losses while at a lower throttle setting. As engineers refined their understanding of the NPSP requirements for the SSME (through a robust testing program), the operational techniques evolved to take advantage of these additional capabilities. Currently the procedure, which for early Space Shuttle missions required a Return-to-Launch-Site abort, now would result in a nominal Main Engine Cut Off (MECO) and no loss of mission objectives.

Effect of different dose rates administration of FSH + LH (Pergonal®)

African Journals Online (AJOL)

The does were randomly assigned to 4 treatment groups administered of 19.0 IU, 38.0 IU and 76.0 IU FSH + LH (Pergonal®) and 1.0 ml physiological saline as the control treatment. The treatments were administered intramuscularly for 3 days consecutively. The results on the number of corpora lutea on the ovary did not ...

Evidence for high-pressure-induced rupture of hydrogen bonds in LH2 photosynthetic antenna pigment-protein complexes

International Nuclear Information System (INIS)

Kangur, L; Leiger, K; Freiberg, A

2008-01-01

The bacteriochlorophyll a-containing LH2 light harvesting complex is an integral membrane protein that catalyzes the photosynthetic process in purple photosynthetic bacteria. The LH2 complexes from Rhodobacter sphaeroides show characteristic strong absorbance at 800 and 850 nm due to the bacteriochlorophyll a molecules confined in two separate areas of the protein. Using these cofactors as intrinsic probes to monitor changes in membrane protein structure, we investigate the response to high hydrostatic pressure up to 2.1 GPa of LH2 complexes embedded into natural membrane environment or extracted with detergent. We demonstrate that high pressure does induce significant alterations to the tertiary structure of the protein in proximity of the protein-bound bacteriochlorophyll a molecules, including breakage of the hydrogen bond they are involved in. The membrane-embedded complexes appear more resilient to damaging effects of the compression than the complexes extracted into detergent environment. This difference has tentatively been explained by more compact structure of the membrane-embedded complexes

Evidence for high-pressure-induced rupture of hydrogen bonds in LH2 photosynthetic antenna pigment-protein complexes

Energy Technology Data Exchange (ETDEWEB)

Kangur, L; Leiger, K; Freiberg, A [Institute of Physics, University of Tartu, Riia 142, Tartu 51014 (Estonia)

2008-07-15

The bacteriochlorophyll a-containing LH2 light harvesting complex is an integral membrane protein that catalyzes the photosynthetic process in purple photosynthetic bacteria. The LH2 complexes from Rhodobacter sphaeroides show characteristic strong absorbance at 800 and 850 nm due to the bacteriochlorophyll a molecules confined in two separate areas of the protein. Using these cofactors as intrinsic probes to monitor changes in membrane protein structure, we investigate the response to high hydrostatic pressure up to 2.1 GPa of LH2 complexes embedded into natural membrane environment or extracted with detergent. We demonstrate that high pressure does induce significant alterations to the tertiary structure of the protein in proximity of the protein-bound bacteriochlorophyll a molecules, including breakage of the hydrogen bond they are involved in. The membrane-embedded complexes appear more resilient to damaging effects of the compression than the complexes extracted into detergent environment. This difference has tentatively been explained by more compact structure of the membrane-embedded complexes.

Extension of Light-Harvesting Ability of Photosynthetic Light-Harvesting Complex 2 (LH2) through Ultrafast Energy Transfer from Covalently Attached Artificial Chromophores.

Science.gov (United States)

Yoneda, Yusuke; Noji, Tomoyasu; Katayama, Tetsuro; Mizutani, Naoto; Komori, Daisuke; Nango, Mamoru; Miyasaka, Hiroshi; Itoh, Shigeru; Nagasawa, Yutaka; Dewa, Takehisa

2015-10-14

Introducing appropriate artificial components into natural biological systems could enrich the original functionality. To expand the available wavelength range of photosynthetic bacterial light-harvesting complex 2 (LH2 from Rhodopseudomonas acidophila 10050), artificial fluorescent dye (Alexa Fluor 647: A647) was covalently attached to N- and C-terminal Lys residues in LH2 α-polypeptides with a molar ratio of A647/LH2 ≃ 9/1. Fluorescence and transient absorption spectroscopies revealed that intracomplex energy transfer from A647 to intrinsic chromophores of LH2 (B850) occurs in a multiexponential manner, with time constants varying from 440 fs to 23 ps through direct and B800-mediated indirect pathways. Kinetic analyses suggested that B800 chromophores mediate faster energy transfer, and the mechanism was interpretable in terms of Förster theory. This study demonstrates that a simple attachment of external chromophores with a flexible linkage can enhance the light harvesting activity of LH2 without affecting inherent functions of energy transfer, and can achieve energy transfer in the subpicosecond range. Addition of external chromophores, thus, represents a useful methodology for construction of advanced hybrid light-harvesting systems that afford solar energy in the broad spectrum.

Mean and oscillating plasma flows and turbulence interactions across the L-H confinement transition.

Science.gov (United States)

Conway, G D; Angioni, C; Ryter, F; Sauter, P; Vicente, J

2011-02-11

A complex interaction between turbulence driven E × B zonal flow oscillations, i.e., geodesic acoustic modes (GAMs), the turbulence, and mean equilibrium flows is observed during the low to high (L-H) plasma confinement mode transition in the ASDEX Upgrade tokamak. Below the L-H threshold at low densities a limit-cycle oscillation forms with competition between the turbulence level and the GAM flow shearing. At higher densities the cycle is diminished, while in the H mode the cycle duration becomes too short to sustain the GAM, which is replaced by large amplitude broadband flow perturbations. Initially GAM amplitude increases as the H-mode transition is approached, but is then suppressed in the H mode by enhanced mean flow shear.

Evolution of the Turbulence Radial Wavenumber Spectrum near the L-H Transition in NSTX Ohmic Discharges

Energy Technology Data Exchange (ETDEWEB)

Kubota, S.; Peebles, W.A., E-mail: skubota@ucla.edu [UCLA, Los Angeles (United States); Bush, C. E.; Maingi, R. [Oak Ridge National Laboratory, Oak Ridge (United States); Zweben, S. J.; Bell, R.; Crocker, N.; Diallo, A.; Kaye, S.; LeBlanc, B. P.; Park, J. K.; Ren, Y. [Princeton Plasma Physics Laboratory, Princeton University, Princeton (United States); Maqueda, R. J. [Nova Photonics, Princeton (United States); Raman, R. [University of Washington, Seattle (United States)

2012-09-15

Full text: The measurement of radially extended meso-scale structures such as zonal flows and streamers, as well as the underlying microinstabilities driving them, is critical for understanding turbulence-driven transport in plasma devices. In particular, the shape and evolution of the radial wavenumber spectrum indicate details of the nonlinear spectral energy transfer, the spreading of turbulence, as well as the formation of transport barriers. In the National Spherical Torus Experiment (NSTX), the FMCW backscattering diagnostic is used to probe the turbulence radial wavenumber spectrum (k{sub r} = 0 - 22 cm-1 ) across the outboard minor radius near the L- to H-mode transition in Ohmic discharges. During the L-mode phase, a broad spectral component (k{sub r} {approx} 2 - 10 cm{sup -1} ) extends over a significant portion of the edge-core from R = 120 to 155 cm ({rho} = 0.4 - 0.95). At the L-H transition, turbulence is quenched across the measurable k{sub r} range at the ETB location, where the radial correlation length drops from {approx} 1.5 - 0.5 cm. The k{sub r} spectrum away from the ETB location is modified on a time scale of tens of microseconds, indicating that nonlocal turbulence dynamics are playing a strong role. Close to the L-H transition, oscillations in the density gradient and edge turbulence quenching become highly correlated. These oscillations are also present in Ohmic discharges without an L-H transition, but are far less frequent. Similar behavior is also seen near the L-H transition in NB-heated discharges. (author)

Controlled ovarian stimulation with r-FSH plus r-LH vs. HMG plus r-FSH in patients candidate for IVF/ICSI cycles: An RCT

Directory of Open Access Journals (Sweden)

Ensieh Shahrokh Tehraninejad

2017-08-01

Full Text Available Background: Different combination of gonadotropin preparation has been introduced with no definite superiority of one over others in in vitro fertilization (IVF, but individualized regimens for each patient are needed. Objective: The aim of the present study was to investigate the effect of controlled ovarian stimulation with recombinant- follicle stimulating hormone (r-FSH plus recombinant-luteinizing hormone (rLH versus human menopausal gonadotropin (HMG plus r-FSH on fertility outcomes in IVF patients. Materials and Methods: This is a randomized clinical trial study that was performed from October 2014-April 2016 on 140 infertile patients with a set of inclusion criteria that referred to infertility clinics in Vali- asr and Gandhi Hospital in Tehran. The women were randomly divided into two treatment groups. The first group (n=70 received rFSH from the second day of cycle and was added HMG in 6th day and the 2nd group (n=70, received rFSH from the second day of cycle and was added recombinant-LH in 6th day. Then ovum Pick-Up and embryo transfer were performed. In this study, we assessed the outcomes such as; chemical and clinical pregnancy rate, live birth and abortion rate. Results: Number of follicles in ovaries, total number of oocytes or M2 oocytes and quality of fetuses has no significant differences between two groups (p>0.05. Total number of fetuses were significantly higher in patients who received rFSH + HMG (p=0.02. Fertility outcomes consisted of: live birth rate, chemical pregnancy and clinical pregnancy rate were higher in rFSH + HMG group in comparison to rFSH +r-LH group (p<0.05. Conclusion: It seems that in IVF patients, HMG + rFSH used for controlled ovarian hyperstimulation have better effects on fertility outcomes, but in order to verify the results, it is recommended to implement studies on more patients.

Orbiter LH2 Feedline Flowliner Cracking Problem. Version 1.0

Science.gov (United States)

Harris, Charles E.; Cragg, Clinton H.; Raju, Ivatury S.; Elliot, Kenny B.; Madaras, Eric I.; Piascik, Robert S.; Halford, Gary R.; Bonacuse, Peter J.; Sutliff, Daniel L.; Bakhle, Milind A.

2005-01-01

In May of 2002, three cracks were found in the downstream flowliner at the gimbal joint in the LH2 feedline at the interface with the Low Pressure Fuel Turbopump (LPFP) of Space Shuttle Main Engine (SSME) #1 of Orbiter OV-104. Subsequent inspections of the feedline flowliners in the other orbiters revealed the existence of 8 additional cracks. No cracks were found in the LO2 feedline flowliners. A solution to the cracking problem was developed and implemented on all orbiters. The solution included weld repair of all detectable cracks and the polishing of all slot edges to remove manufacturing discrepancies that could initiate new cracks. Using the results of a fracture mechanics analysis with a scatter factor of 4 on the predicted fatigue life, the orbiters were cleared for return to flight with a one-flight rationale requiring inspections after each flight. OV-104 flew mission STS-112 and OV-105 flew mission STS-113. The post-flight inspections did not find any cracks in the repaired flowliners. At the request of the Orbiter Program, the NESC conducted an assessment of the Orbiter LH2 Feedline Flowliner cracking problem with a team of subject matter experts from throughout NASA.

Male goat vocalizations stimulate the estrous behavior and LH secretion in anestrous goats that have been previously exposed to bucks.

Science.gov (United States)

Delgadillo, José Alberto; Vielma, Jesús; Hernandez, Horacio; Flores, José Alfredo; Duarte, Gerardo; Fernández, Ilda Graciela; Keller, Matthieu; Gelez, Hélène

2012-09-01

We investigated whether live vocalizations emitted by bucks interacting with anestrous females stimulate secretion of LH, estrous behavior and ovulation in anestrous goats. In experiment 1, bucks rendered sexually active by exposure to long days followed by natural photoperiod were exposed in a light-proof-building to five anestrous females. Buck vocalizations were reproduced through a microphone-amplifier-loudspeaker system to an open pen where one group of goats (n=6) was exposed for 10 days to these live vocalizations. Another group of females (n=6) was isolated from males and vocalizations. The proportion of goats displaying estrous behavior was significantly higher in females exposed to buck vocalizations than in females isolated from males. The proportion of goats that ovulated did not differ between the 2 groups (exposed to males versus isolated). In experiment 2, female goats that either had previous contact with males (n=7), or no previous contact with males (n=7) were exposed to live buck vocalizations, reproduced as described in experiment 1, for 5 days. The number and amplitude of LH pulses did not differ between groups before exposition to buck vocalizations. Five days of exposure to male vocalizations significantly increased LH pulsatility only in females that had previous contact with males, while LH pulse amplitude was not modified. We concluded that live buck vocalizations can stimulate estrous behavior and LH secretion in goats if they have had previous contact with bucks. Copyright © 2012 Elsevier Inc. All rights reserved.

Elimination of polarity in the carotenoid terminus promotes the exposure of B850-binding sites (Tyr 44, 45) and ANS-mediated energy transfer in LH2 complexes of Rhodobacter sphaeroides.

Science.gov (United States)

Liu, Yuan; Wu, Yongqiang; Xu, Chunhe

2004-12-10

Carotenoids in the peripheral light-harvesting complexes (LH2) of the green mutant (GM309) of Rhodobacter sphaeroides were identified as containing neurosporenes, which lack the polar CH(3)O group, compared to spheroidenes in native-LH2 of R. sphaeroides 601. After LH2 complexes were treated with 1-anilino-8-naphthalene sulfonate (ANS), new energy transfer pathways from ANS or tryptophan to carotenoids were discovered in both native- and GM309-LH2. The carotenoid fluorescence intensity of GM309-LH2 was greater than that of native-LH2 when bound with ANS, suggesting that the elimination of polarity in the neurosporene increases the energy transfer from ANS to carotenoid. The fact that two alpha-tyrosines (alpha-Tyr 44, 45, B850-binding sites) in each alpha-apoprotein of GM309-LH2 were more easily modified than those of native-LH2 by N-acetylimidazole (NAI) indicates that the elimination of polarity in the neurosporene terminus increases the exposure of these sites to solution.

Altered neuroendocrine regulation of gonadotropin secretion in women distance runners.

Science.gov (United States)

Veldhuis, J D; Evans, W S; Demers, L M; Thorner, M O; Wakat, D; Rogol, A D

1985-09-01

We tested the hypothesis that the neuroendocrine control of gonadotropin secretion is altered in certain women distance runners with secondary amenorrhea. To this end, we quantitated the frequency and amplitude of spontaneous pulsatile LH secretion during a 24-h interval in nine such women. The ability of the pituitary gland to release LH normally was assessed by administration of graded bolus doses of GnRH during the subsequent 8 h. Compared to normally menstruating women, six of nine amenorrheic distance runners had a distinct reduction in spontaneous LH pulse frequency, with one, three, six, five, four, or two pulses per 24 h (normal, 8-15 pulses/24 h). This reduction in LH pulse frequency occurred without any significant alterations in plasma concentrations of estradiol and free testosterone or 24-h integrated serum concentrations of LH, FSH, or PRL. Moreover, in long-distance runners, the capacity of the pituitary gland to release LH was normal or accentuated in response to exogenous pulses of GnRH. In the six women athletes with diminished spontaneous LH pulsatility, acute ovarian responsiveness also was normal, since serum estradiol concentrations increased normally in response to the GnRH-induced LH pulses. Although long-distance runners had significantly lower estimated percent body fat compared to control women, specific changes in pulsatile gonadotropin release did not correlate with degree of body leanness. In summary, certain long-distance runners with secondary amenorrhea or severe oligomenorrhea have unambiguously decreased spontaneous LH pulse frequency with intact pituitary responsiveness to GnRH. This neuroendocrine disturbance may be relevant to exercise-associated amenorrhea, since pulsatile LH release is a prerequisite for cyclic ovarian function. We speculate that such alterations in pulsatile LH release in exercising women reflect an adaptive response of the hypothalamic pulse generator controlling the intermittent GnRH signal to the

Identification of the upper exciton component of the B850 bacteriochlorophylls of the LH2 antenna complex, using a B800-free mutant of Rhodobacter sphaeroides.

NARCIS (Netherlands)

Koolhaas, M.H.C.; Frese, R.N.; Fowler, G.J.S.; Bibby, T.S.; Georgakopoulou, S.; van der Zwan, G.; Hunter, C.N.; van Grondelle, R.

1998-01-01

In this paper, we report the circular dichroism (CD) spectra of two types of LH2 -only mutants of Rhodobacter sphaeroides. In the first, only the wild type LH2 is present, while in the second, the B800 binding site of LH2 has been either destabilized or removed. For the first time, we have

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

Science.gov (United States)

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

2016-06-01

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

Investigation of the critical edge ion heat flux for L-H transitions in Alcator C-Mod and its dependence on B T

Science.gov (United States)

Schmidtmayr, M.; Hughes, J. W.; Ryter, F.; Wolfrum, E.; Cao, N.; Creely, A. J.; Howard, N.; Hubbard, A. E.; Lin, Y.; Reinke, M. L.; Rice, J. E.; Tolman, E. A.; Wukitch, S.; Ma, Y.; ASDEX Upgrade Team; Alcator C-Mod Team

2018-05-01

This paper presents investigations on the role of the edge ion heat flux for transitions from L-mode to H-mode in Alcator C-Mod. Previous results from the ASDEX Upgrade tokamak indicated that a critical value of edge ion heat flux per particle is needed for the transition. Analysis of C-Mod data confirms this result. The edge ion heat flux is indeed found to increase linearly with density at given magnetic field and plasma current. Furthermore, the Alcator C-Mod data indicate that the edge ion heat flux at the L-H transition also increases with magnetic field. Combining the data from Alcator C-Mod and ASDEX Upgrade yields a general expression for the edge ion heat flux at the L-H transition. These results are discussed from the point of view of the possible physics mechanism of the L-H transition. They are also compared to the L-H power threshold scaling and an extrapolation for ITER is given.

The combined effects of pituitary gonadotropin and estrogen on the ovarian response of rats to /sup 125/I-LH uptake

Energy Technology Data Exchange (ETDEWEB)

Hosomichi, T; Yoshida, H; Ichinohe, K [Wakayama Medical Coll. (Japan)

1974-12-01

It discussed the effect of estradiol on the ovarian response of mature rats and hypophysectomized mature rats to /sup 125/I-LH uptake and the combined effects of FSH and estradiol. The constant concentration on the change of blood concentration with time was maintained in about one hour when given with the intravenous infusion of /sup 125/I-LH prepared for radioimmunoassay. Moreover, increased uptake of /sup 125/I-LH was noted especially in ovaries, livers, kidneys and thyroid glands, and by giving estradiol the uptake was increased to a level which was about twice the normal. Of hypophysectomized rats, the uptake was increased to a level which was about four times the normal in the group of rats which were given estradiol for eight days and also in the group of rats which were given FSH for four days. The effect with four-day-estradiol administration following four-day-FSH administration was to increase to a level which was about six times the group which was given each single administration. These experimental results are apparently due to the effects of FSH and estradiol on follicles and thus follicles are ready for LH uptake.

The mutation of carotenoids affects the energy transfer in LH2 light harvesting complexes from Rhodobacter sphaeroides 601 at room temperature

International Nuclear Information System (INIS)

Liu Weimin; Liu Yuan; Guo Lijun; Xu Chunhe; Qian Shixiong

2006-01-01

Energy transfer in two kinds of peripheral antenna complexes LH2 from Rhodobacter sphaeroides 601 was studied by absorption, fluorescence emission, time-resolved fluorescence and femtosecond transient absorption spectroscopy at room temperature. These two complexes are LH2 (RS601) and green carotenoid mutated LH2 (GM309). The obtained results demonstrate that: (a) compared with spheroidenes, which have ten carbon-carbon double bonds in native RS601, carotenoids in GM309 were identified as containing neurosporenes with nine carbon-carbon double bonds, which show a significant blue shift of ∼20 nm in the three absorption peaks because of the higher energy levels of neurosporene than those of spheroidene, (b) the higher energy levels of neurosporene in GM309 induce a lower B800 → B850 energy transfer rate and efficiency as compared to that in RS601 resulting from the relatively higher band gap between the donor of B800 and the bridge of the carotenoids (c) the same lifetime of the B850 excited singlet state is observed in these two LH2 complexes

Significance of determination of female sex hormones (E2, LH, FSH), insulin-like growth factor I (IGF-I) and leptin in girls with precocious puberty

International Nuclear Information System (INIS)

Huang Jianrong

2004-01-01

Objective: To investigate the diagnostic value of determination of serum levels of estradiol (E 2 ), luteinizing hormone (LH) and follicle stimulating hormone (FSH), insulin-like growth factor (IGF-I) and leptin in girls with idiopathic central precocious puberty (ICPP). Methods: Serum E 2 , LH, FSH, IGF-I (with chemiluminescence immunoassay) and leptin (with RIA) levels were determined in 35 girls with early development of breast as the sign of precocious puberty, of which, 15 was considered to be of the ICPP group and 20 of simple premature thelarche group (SPT). Criteria of diagnosis for ICPP were: peak LH value>12IU/L and LH/FSH>1 after GnRH stimulating test. Results: Serum E 2 , LH, FSH, IGF-I leptin levels in girls with ICPP were significantly higher than those in the girls with SPT (P 0.2 as the cut-off value for diagnosis of ICPP there would still be a positive rate of 86.6% suggesting that the diagnostic criteria might be set lower. Serum IGF-I levels were positively correlated to those of E 2 (r=0.47, P 2 and IGF-I. Conclusion: Determinations of serum E 2 , LH, FHS, IGF-I and leptin levels were helpful for the early diagnosis of ICPP. (author)

Developmental Programming: Prenatal and Postnatal Androgen Antagonist and Insulin Sensitizer Interventions Prevent Advancement of Puberty and Improve LH Surge Dynamics in Prenatal Testosterone-Treated Sheep.

Science.gov (United States)

Padmanabhan, Vasantha; Veiga-Lopez, Almudena; Herkimer, Carol; Abi Salloum, Bachir; Moeller, Jacob; Beckett, Evan; Sreedharan, Rohit

2015-07-01

Prenatal T excess induces maternal hyperinsulinemia, early puberty, and reproductive/metabolic defects in the female similar to those seen in women with polycystic ovary syndrome. This study addressed the organizational/activational role of androgens and insulin in programming pubertal advancement and periovulatory LH surge defects. Treatment groups included the following: 1) control; 2) prenatal T; 3) prenatal T plus prenatal androgen antagonist, flutamide; 4) prenatal T plus prenatal insulin sensitizer, rosiglitazone; 5) prenatal T and postnatal flutamide; 6) prenatal T and postnatal rosiglitazone; and 7) prenatal T and postnatal metformin. Prenatal treatments spanned 30-90 days of gestation and postnatal treatments began at approximately 8 weeks of age and continued throughout. Blood samples were taken twice weekly, beginning at approximately 12 weeks of age to time puberty. Two-hour samples after the synchronization with prostaglandin F2α were taken for 120 hours to characterize LH surge dynamics at 7 and 19 months of age. Prenatal T females entered puberty earlier than controls, and all interventions prevented this advancement. Prenatal T reduced the percentage of animals having LH surge, and females that presented LH surge exhibited delayed timing and dampened amplitude of the LH surge. Prenatal androgen antagonist, but not other interventions, restored LH surges without normalizing the timing of the surge. Normalization of pubertal timing with prenatal/postnatal androgen antagonist and insulin sensitizer interventions suggests that pubertal advancement is programmed by androgenic actions of T involving insulin as a mediary. Restoration of LH surges by cotreatment with androgen antagonist supports androgenic programming at the organizational level.

New features of L-H transition in limiter H-modes of JIPP T-IIU

International Nuclear Information System (INIS)

Toi, K.; Morita, S.; Kawahata, K.

1992-09-01

In limiter H-modes of JIPP T-IIU, a new type of L-H transition preceded by an ELM is observed. The preceding ELM (pre-ELM) appears just prior to the L-H transition. This type of transition is usually observed in H-modes of JIPP T-IIU. The L-H transition without the pre-ELM is triggered only in the case when a sufficiently large rapid current ramp down is emploied. In H-modes with constant q(a)∼3.5-4.5, coherent magnetic oscillations with m=3/n=1 destabilized during L-phase are further enhanced at the pre-ELM, and suppressed suddenly at the transition. This mode is situated in the region of the transport barrier. Propagation frequency of the m=3/n=1 mode, which may be affected by plasma mass rotation, rises appreciably (by ∼ 10 %) during H-phase with frequent ELMs, but remains unchanged for at least 200 μs after the transition. Behaviours of the m=3/n=1 and m=2/n=1 modes are well explained by quasi-linear resistive tearing mode analysis for modelled toroidal current density profiles slightly detached from the limiter. These experimental results suggest that the transition is controlled by the change of a magnetic field structure relating to the modification of a toroidal current density profile near the edge. The possibility for the development of edge radial electric field as a consequence of the transition is discussed. (author)

High efficiency light harvesting by carotenoids in the LH2 complex from photosynthetic bacteria: unique adaptation to growth under low-light conditions.

Science.gov (United States)

Magdaong, Nikki M; LaFountain, Amy M; Greco, Jordan A; Gardiner, Alastair T; Carey, Anne-Marie; Cogdell, Richard J; Gibson, George N; Birge, Robert R; Frank, Harry A

2014-09-25

Rhodopin, rhodopinal, and their glucoside derivatives are carotenoids that accumulate in different amounts in the photosynthetic bacterium, Rhodoblastus (Rbl.) acidophilus strain 7050, depending on the intensity of the light under which the organism is grown. The different growth conditions also have a profound effect on the spectra of the bacteriochlorophyll (BChl) pigments that assemble in the major LH2 light-harvesting pigment-protein complex. Under high-light conditions the well-characterized B800-850 LH2 complex is formed and accumulates rhodopin and rhodopin glucoside as the primary carotenoids. Under low-light conditions, a variant LH2, denoted B800-820, is formed, and rhodopinal and rhodopinal glucoside are the most abundant carotenoids. The present investigation compares and contrasts the spectral properties and dynamics of the excited states of rhodopin and rhodopinal in solution. In addition, the systematic differences in pigment composition and structure of the chromophores in the LH2 complexes provide an opportunity to explore the effect of these factors on the rate and efficiency of carotenoid-to-BChl energy transfer. It is found that the enzymatic conversion of rhodopin to rhodopinal by Rbl. acidophilus 7050 grown under low-light conditions results in nearly 100% carotenoid-to-BChl energy transfer efficiency in the LH2 complex. This comparative analysis provides insight into how photosynthetic systems are able to adapt and survive under challenging environmental conditions.

Cetrorelix suppresses the preovulatory LH surge and ovulation induced by ovulation-inducing factor (OIF present in llama seminal plasma

Directory of Open Access Journals (Sweden)

Letelier Claudia

2011-05-01

Full Text Available Abstract Background The purpose of the study was to determine if the effect of llama OIF on LH secretion is mediated by stimulation of the hypothalamus or pituitary gland. Methods Using a 2-by-2 factorial design to examine the effects of OIF vs GnRH with or without a GnRH antagonist, llamas with a growing ovarian follicle greater than or equal to 8 mm were assigned randomly to four groups (n = 7 per group and a pre-treated with 1.5 mg of GnRH antagonist (cetrorelix acetate followed by 1 mg of purified llama OIF, b pre-treated with 1.5 mg of cetrorelix followed by 50 micrograms of GnRH, c pre-treated with a placebo (2 ml of saline followed by 1 mg of purified llama OIF or d pre-treated with a placebo (2 ml of saline followed by 50 micrograms of GnRH. Pre-treatment with cetrorelix or saline was given as a single slow intravenous dose 2 hours before intramuscular administration of either GnRH or OIF. Blood samples for LH measurement were taken every 15 minutes from 1.5 hours before to 8 hours after treatment. The ovaries were examined by ultrasonography to detect ovulation and CL formation. Blood samples for progesterone measurement were taken every-other-day from Day 0 (day of treatment to Day 16. Results Ovulation rate was not different (P = 0.89 between placebo+GnRH (86% and placebo+OIF groups (100%; however, no ovulations were detected in llamas pre-treated with cetrorelix. Plasma LH concentrations surged (P Conclusion Cetrorelix (GnRH antagonist inhibited the preovulatory LH surge induced by OIF in llamas suggesting that LH secretion is modulated by a direct or indirect effect of OIF on GnRH neurons in the hypothalamus.

Lower-hybrid (LH) oscillitons evolved from ion-acoustic (IA)/ion-cyclotron (IC) solitary waves: effect of electron inertia

Science.gov (United States)

Ma, J. Z. G.; Hirose, A.

2010-05-01

Lower-hybrid (LH) oscillitons reveal one aspect of geocomplexities. They have been observed by rockets and satellites in various regions in geospace. They are extraordinary solitary waves the envelop of which has a relatively longer period, while the amplitude is modulated violently by embedded oscillations of much shorter periods. We employ a two-fluid (electron-ion) slab model in a Cartesian geometry to expose the excitation of LH oscillitons. Relying on a set of self-similar equations, we first produce, as a reference, the well-known three shapes (sinusoidal, sawtooth, and spiky or bipolar) of parallel-propagating ion-acoustic (IA) solitary structures in the absence of electron inertia, along with their Fast Fourier Transform (FFT) power spectra. The study is then expanded to illustrate distorted structures of the IA modes by taking into account all the three components of variables. In this case, the ion-cyclotron (IC) mode comes into play. Furthermore, the electron inertia is incorporated in the equations. It is found that the inertia modulates the coupled IA/IC envelops to produce LH oscillitons. The newly excited structures are characterized by a normal low-frequency IC solitary envelop embedded by high-frequency, small-amplitude LH oscillations which are superimposed upon by higher-frequency but smaller-amplitude IA ingredients. The oscillitons are shown to be sensitive to several input parameters (e.g., the Mach number, the electron-ion mass/temperature ratios, and the electron thermal speed). Interestingly, whenever a LH oscilliton is triggered, there occurs a density cavity the depth of which can reach up to 20% of the background density, along with density humps on both sides of the cavity. Unexpectedly, a mode at much lower frequencies is also found beyond the IC band. Future studies are finally highlighted. The appendices give a general dispersion relation and specific ones of linear modes relevant to all the nonlinear modes encountered in the text.

Spatial structure of compound dither in L/H transition

International Nuclear Information System (INIS)

Toda, Shinichiro; Itoh, Kimitaka; Itoh, Sanae I.; Yagi, Masatoshi; Fukuyama, Atsushi

2000-03-01

To study the plasma evolution and spatial structure at the L/H transition, the double hysteresis is examined by use of the 1-dimensional transport model equations. Three mechanisms for the bipolar losses, i.e., the loss cone loss, collisional bulk viscosity loss of ions and the anomalous loss are simultaneously retained. Five-fold multiple bifurcations are found to exist at the plasma edge, similar to the previous 0-dimensional study. Double hysteresis causes a self-generated oscillation, which is attributed to the compound dither, a kind of ELMs. Spatio-temporal evolution of the compound dither is analyzed. (author)

Dynamics of Exciton Relaxation in LH2 Antenna Probed by Multipulse Nonlinear Spectroscopy

NARCIS (Netherlands)

Novoderezhkin, V.I.; Cohen Stuart, T.A.; van Grondelle, R.

2011-01-01

We explain the relaxation dynamics in the LH2-B850 antenna as revealed by multipulse pump - dump - probe spectroscopy (Th. A. Cohen StuartM. VengrisV. I. NovoderezhkinR. J. CogdellC. N. HunterR. van Grondelle, submitted). The theory of pump - dump - probe response is evaluated using the doorway -

Endocrine correlates of reproduction in the wolf. I. Serum progesterone, estradiol and LH during the estrous cycle

Science.gov (United States)

Seal, U.S.; Plotka, E.D.; Packard, J.M.; Mech, L.D.

1979-01-01

The estrous cycle of 10 intact female wolves, aged 8 months-8 years at the initiation of the study, was characterized in terms of vaginal smears, behavioral observations and serum concentrations of estradiol-17β, progesterone and luteinizing hormone (LH) from January through June. No estrous cycles occurred in these animals between June and December. All were housed with male wolves. Two pups and 1 adult remained anestrous during this interval. One pup and 2 adults produced litters between May 4-6. Four adults exhibited endocrine changes similar to those of the pregnant animals but no litters or signs of abortion were observed. The duration of proestrus was 15.7 ± 1.6 days (X ± SEM, n = 6), of estrus 9.0 ± 1.2 days (n = 4) and of the luteal phase 63 ± 2 days (n = 6). The duration of pregnancy was between 60-65 days. The anestrous females (86 blood samples) had 6 progesterone values between 1-2 ng/ml and the remainder below 1 ng/ml. Their estradiol-17β concentrations varied between 5-20 pg/ml. Values for LH varied between 0.1-2 ng/ml, except for 1 value above 15 ng/ml for each of the 2 anestrous pups on 12 January.The 7 estrous animals (260 samples) included 1 pup and 2 adults that delivered litters. Estradiol-17β varied between 10-20 pg/ml during proestrus, peaked at 30-70 pg/ml late in proestrus and fluctuated between 10-30 pg/ml during pregnancy or the duration of luteal activity in the nonpregnant animals. The preovulatory LH rise, 5-15 ng/ml, extended over 3 days during and immediately following the peak estradiol-17β values. An earlier elevation in LH was observed in 3 of the estrous animals. Progesterone began increasing during the LH surge and peaked 11-14 days later at 22-40 ng/ml. Progesterone concentrations greater than 3 ng/ml were maintained for 56-68 days in 6 of the 7 animals exhibiting estrus. Progesterone concentrations declined at parturition but continued to fluctuate between 0.2-3 ng/ml for 3-6 weeks.

Modelling of profile control with LH wave injection in the HL-2A single-null divertor plasma

International Nuclear Information System (INIS)

Gao Qingdi; Yuan Baoshan; Li Fangzhu; Wang, Aike; Budny, R.V.

2005-01-01

In the HL-2A tokamak a single-null divertor configuration has been established. The separatrix of the single-null diverted plasma was identified with a filament model, and the determined striking area on the target plate is in agreement with the measurements of electric probe array. Higher power LH wave (1.5MW) is injected to the diverted plasma with a nearly symmetric spectrum. Dominant electron heating and current profile control are investigated with numerical simulation. Plasma heating by electron Landau interaction results in operation scenarios of preferentially dominant electron heating. Due to the off-axis driven current, an optimized q-profile is formed, and an enhanced confinement regime with steep electron temperature gradient is produced. The clear decrease of the electron thermal conductivity in the LH power deposition region shows that an electron-ITB is developed. When higher LH power injects into the target plasma that is heated by NBI (0.5MW), the ion temperature has a large increment in addition to the high increase of electron temperature. The temperature profiles indicate that an enhanced core confinement is established with both ion-ITB and electron-ITB developed. (author)

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

Carotenoid stoichiometry in the LH2 crystal: no spectral evidence for the presence of the second molecule in the alpha/beta-apoprotein dimer.

Science.gov (United States)

Gall, Andrew; Gardiner, Alastair T; Cogdell, Richard J; Robert, Bruno

2006-07-10

In this work we have investigated the carotenoid-protein interactions in LH2 complexes of Rhodopseudomonas acidophila both in "free in solution" mixed-micelles and in three-dimensional crystals by Raman spectroscopy in resonance with the carotenoid (Car) molecules. We show that the Car molecules when bound to their binding pockets show no significant differences when the complexes are "free in solution" or packed in crystalline arrays. Furthermore, there is no significant wavelength dependence in the Raman spectrum of the Car molecules of LH2. This indicates that there is only one Car configuration in LH2 and thus only one molecule per alpha/beta-heterodimer.

Leydig cell micronodules are a common finding in testicular biopsies from men with impaired spermatogenesis and are associated with decreased testosterone/LH ratio

DEFF Research Database (Denmark)

Holm, Mette; Rajpert-De Meyts, Ewa; Andersson, Anna-Maria

2003-01-01

were examined using a semi-quantitative stereological method. In patients, serum concentrations of testosterone, sex hormone binding globulin (SHBG), luteinizing hormone (LH), follicle stimulating hormone (FSH), oestradiol and inhibin-B were correlated with the findings on histological examination......, with the exception of testes with bilateral micronodules, which had significantly increased Leydig cell volume compared to those without micronodules. The number of micronodules correlated positively to LH (r = 0.577, p ... in the hyperstimulated testes, as reflected by an increased LH/testosterone ratio. In conclusion, Leydig cell micronodules were more frequent in biopsies with impaired spermatogenesis and associated with decreased ratios of testicular hormones to gonadotrophins. The presence of micronodules thus seems...

The use of recombinant human LH (lutropin alfa) in the late stimulation phase of assisted reproduction cycles: a double-blind, randomized, prospective study.

Science.gov (United States)

Tarlatzis, B; Tavmergen, E; Szamatowicz, M; Barash, A; Amit, A; Levitas, E; Shoham, Z

2006-01-01

The effect of recombinant human LH (r-hLH; lutropin alfa) in women undergoing controlled ovarian stimulation with recombinant human FSH (r-hFSH) prior to IVF was investigated. After down-regulation with the GnRH agonist, buserelin, 114 normo-ovulatory women (aged 18-37 years) received r-hFSH alone until the lead follicle reached a diameter of 14 mm. Patients were then randomized in a double-blind fashion to receive r-hFSH in addition to r-hLH, 75 IU s.c., or placebo daily for a maximum of 10 days prior to oocyte retrieval and IVF. The primary end-point was the number of metaphase II oocytes. There were no significant differences between treatment groups for the primary end-point. Serum estradiol concentrations on the day of HCG administration were significantly higher in the group receiving r-hLH plus r-hFSH than in the group receiving r-hFSH alone (P = 0.0001), but there were no significant differences between the groups in dose and duration of r-hFSH treatment required, oocyte maturation, fertilization rate, pregnancy rate and live birth rate. In this patient population, the addition of r-hLH during the late follicular phase of a long GnRH agonist and r-hFSH stimulation cycle provides no further benefit in terms of oocyte maturation or other end-points.

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

Science.gov (United States)

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

1997-06-01

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

Protein dynamics revealed in the excitonic spectra of single LH2 complexes

International Nuclear Information System (INIS)

Valkunas, Leonas; Janusonis, Julius; Rutkauskas, Danielis; Grondelle, Rienk van

2007-01-01

The fluorescence emission spectrum of single peripheral light-harvesting (LH2) complexes of the photosynthetic purple bacterium Rhodopseudomonas acidophila exhibits remarkable dynamics on a time scale of several minutes. Often the spectral properties are quasi-stable; sometimes large spectral jumps to the blue or to the red are observed. To explain the dynamics, every pigment is proposed to be in two conformational substates with different excitation energies, which originate from the conformational state of the protein as a result of pigment-protein interaction. Due to the excitonic coupling in the ring of 18 pigments, the two-state assumption generates a substantial amount of distinct spectroscopic states, which reflect part of the inhomogeneous distributed spectral properties of LH2. To describe the observed dynamics, spontaneous and light-induced transitions are introduced between the two states. For each 'realization of the disorder', the spectral properties are calculated using a disordered exciton model combined with the modified Redfield theory to obtain realistic spectral line shapes. The single-molecule fluorescence peak (FLP) distribution, the distribution dependence on the excitation intensity, and the FLP time traces are well described within the framework of this model

Relationship of testis size and LH levels with incidence of major adverse cardiovascular events in older men with sexual dysfunction.

Science.gov (United States)

Rastrelli, Giulia; Corona, Giovanni; Lotti, Francesco; Boddi, Valentina; Mannucci, Edoardo; Maggi, Mario

2013-11-01

Measurement of testis volume (TV) is a reliable clinical procedure that predicts reproductive fitness. However, the role of TV in overall and cardiovascular (CV) fitness has never been studied. The study aims to analyze the clinical correlates of TV in patients with sexual dysfunction (SD) and to verify the value of this parameter and its determinants (i.e., luteinizing hormone [LH] levels) in predicting major adverse CV events (MACE). A consecutive series of 2,809 subjects without testiculopathy (age 51.2 ± 13.1) consulting for SD was retrospectively studied. A subset of this sample (n=1,395) was enrolled in a longitudinal study. Several clinical and biochemical parameters were investigated. After adjusting for confounders, TV was negatively associated with both LH (Adj. r=-0.234; PTV (hazard ratio [HR]=1.041 [1.021-1.061], PTV (Adj. r=0.157; PTV were only partially related to changes in gonadotropin levels. In the longitudinal analysis, after adjusting for confounders, TV was associated with a higher incidence of MACE (HR=1.066 [1.013-1.122]; P=0.014), and the stepwise introduction in the Cox model of lifestyle factors, mean blood pressure and body mass index progressively smoothed out the association, which was no longer statistically significant in the fully adjusted model. Conversely, the association of higher LH levels with increased incidence of MACE was not attenuated by the progressive introduction of the aforementioned confounders in the model. Our data show that in SD subjects, TV and LH are associated with an adverse CV risk profile that mediate the higher TV-associated incidence of MACE. High LH levels are an independent marker of CV risk. Further studies are needed for clarifying determinants and mechanisms of testis enlargement that, beyond gonadotropins, could mediate the increased incidence of MACE. © 2013 International Society for Sexual Medicine.

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

Science.gov (United States)

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

2000-03-01

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

Role of MHD activity in LH-assisted discharges in the PBX-M tokamak

International Nuclear Information System (INIS)

Talvard, M.; Bell, R.E.; Bernabei, S.; Kaye, S.; Okabayashi, M.; Sesnic, S.; von Goeler, S.

1995-01-01

A data base for the 1993 run period of PBX-M has been documented (i) to investigate whether it was possible to forecast the development of MHD instabilities often observed in LH assisted discharges and (ii) to detail the origin, the nature and the effects of those instabilities. The deposition radius of the RF current, the plasma internal inductance and the LH power are used to separate MHD active and quiescent regimes prior the MHD onset. 1/1, 2/1, 3/1 global modes driven by the m = 2, n = 1 component are observed in discharges with LHCD. The destabilization is attributed to an increase of the current density gradient within the q = 2 surface. MHD fluctuations reduce the soft x-ray and hard x-ray intensities mainly around the RF current deposition radius. Minor disruptions with large inversion radii and mode locking are analyzed. Pi possible precursor to the MHD is evidenced on the hard x-ray horizontal profiles. A resonance between fast trapped electrons and turbulent waves present in the background plasma is proposed to support the observations

Comparative effects of sub-stimulating concentrations of non-human versus human Luteinizing Hormones (LH) or chorionic gonadotropins (CG) on adenylate cyclase activation by forskolin in MLTC cells.

Science.gov (United States)

Nguyen, Thi-Mong Diep; Filliatreau, Laura; Klett, Danièle; Combarnous, Yves

2018-05-15

We have compared various Luteinizing Hormone (LH) and Chorionic Gonadotropin (CG) preparations from non-human and human species in their ability to synergize with 10 µM forskolin (FSK) for cyclic AMP intracellular accumulation, in MLTC cells. LH from rat pituitary as well as various isoforms of pituitary ovine, bovine, porcine, equine and human LHs and equine and human CG were studied. In addition, recombinant human LH and CG were also compared with the natural human and non-human hormones. Sub-stimulating concentrations of all LHs and CGs (2-100 pM) were found to stimulate cyclic AMP accumulation in MLTC cells in the presence of an also non-stimulating FSK concentration (10 µM). Like rat LH, the most homologous available hormone for mouse MLTC cells, all non-human LHs and CG exhibit a strong potentiating effect on FSK response. The human, natural and recombinant hLH and hCG also do so but in addition, they were found to elicit a permissive effect on FSK stimulation. Indeed, when incubated alone with MLTC cells at non-stimulating concentrations (2-70 pM) hLH and hCG permit, after being removed, a dose-dependent cyclic AMP accumulation with 10 µM FSK. Our data show a clearcut difference between human LH and CG compared to their non-human counterparts on MLTC cells adenylate cyclase activity control. This points out the risk of using hCG as a reference ligand for LHR in studies using non-human cells. Copyright © 2018 Elsevier Inc. All rights reserved.

The MuCool/MICE LH2 Absorber Program

International Nuclear Information System (INIS)

Cummings, Mary Anne

2004-01-01

Hydrogen absorber R and D for the MuCool Collaboration is actively pushing ahead on two parallel and complementary fronts. The continuing LH2 engineering and technical developments by the MuCool group, conducted by ICAR institutions (NIU, IIT and UIUC), the University of Mississippi and Oxford University in cooperation with Fermilab, are summarized here, including plans for the first tests of an absorber prototype from Osaka University and KEK cooled by internal convection at the newly constructed FNAL MuCool Test Area (MTA). Designs for the high-power test of another absorber prototype (employing external heat exchange) are complete and the system will be installed by summer 2004. A convection-cooled absorber design is being developed for the approved MICE cooling demonstration at Rutherford Appleton Laboratory

Spontaneous L-H transitions under marginal hot cathode biasing in the Tohoku University Heliac

International Nuclear Information System (INIS)

Kitajima, S; Takahashi, H; Tanaka, Y; Utoh, H; Yokoyama, M; Inagaki, S; Suzuki, Y; Nishimura, K; Shinde, J; Ogawa, M; Iwazaki, K; Aoyama, H; Okamoto, A; Shinto, K; Sasao, M

2006-01-01

A series of hot cathode biasing experiments with marginal conditions for improved mode transition were carried out in the Tohoku University Heliac (TU-Heliac). Spontaneous transitions were observed accompanied by a delay of a few milliseconds. Transition conditions were explored over a wide operation range. The transition points can be identified clearly and easily in the operation range, because the plasma parameters changed slowly until the spontaneous transition. Although operation conditions were spread over a wide range, poloidal Mach numbers for transitions were concentrated in the range of -M p = 1-2 and normalized driving forces for poloidal rotation agreed well with the local maximum value of ion viscosity predicted by neoclassical theory. The local maximum of ion viscosity against the poloidal Mach number was found to play a key role in the L-H transition. Marginal hot cathode biasing is suitable to determine the threshold conditions for the L-H transition

KEA-144: Final Results of the Ground Operations Demonstration Unit for Liquid Hydrogen (GODU-LH2) Project

Science.gov (United States)

Notardonato, William; Fesmire, James; Swanger, Adam; Jumper, Kevin; Johnson, Wesley; Tomsik, Thomas

2017-01-01

GODU-LH2 system has successfully met all test objectives at the 33%, 67%, and 100% tank fill level. Complete control over the state of the fluid has been demonstrated using Integrated Refrigeration and Storage (IRAS). Almost any desired point along the H2saturation curve can essentially be "dialed in" and maintained indefinitely. System can also be used to produce densified hydrogen in large quantities to the triple point. Exploring multiple technology infusion paths. Studying implementation of IRAS technology into new LH2sphere for EM-2 at LC39B. Technical interchange also occurring with STMD, LSP, ULA, DoE, KIST, Kawasaki, Shell Oil, SpaceX, US Coast Guard, and Virgin Galactic.

Evidence of Zonal-Flow-Driven Limit-Cycle Oscillations during L-H Transition and at H-mode Pedestal of a New Small-ELM Regime in EAST

DEFF Research Database (Denmark)

Xu, G.; Wang, H.; Guo, H.

Small-amplitude edge localized oscillations have been observed, for the first time, in EAST preceding the L-H transition at marginal input power, which manifest themselves as dithering in the divertor D signals at a frequency under 4 kHz, much lower than the GAM frequency. Detailed measurements...... edge turbulence in the range of 30 100 kHz and low-frequency Er oscillations. Just prior to the L-H transition, the Er oscillations often evolve into intermittent negative Er spikes. The Er oscillations, as well as the Er spikes, are strongly correlated with the turbulence driven Reynolds stress, thus...... providing a direct evidence of the zonal flows for the L-H transition at marginal input power. Furthermore, near the transition threshold sawtooth heat pulses appear to periodically enhance the dithering, finally triggering the L-H transition after a big sawtooth crash. The zonal flow induced limit...

Safety Extension Study Of Leuprolide Acetate (Lupron Depot) In The Treatment Of Central Precocious Puberty

Science.gov (United States)

2014-01-08

Precocious; Leuprolide Acetate; Luteinizing Hormone (LH); Gonadotrophin-releasing Hormone Agonist (GnRHa); Tanner Staging; Depot Formulation; Suppression of LH; Central Precocious Puberty (CPP); Gonadotrophin-releasing Hormone (GnRH); Lupron; GnRH Analog; Pediatrics Central Precocious Puberty

A METHOD USING GNSS LH-REFLECTED SIGNALS FOR SOIL ROUGHNESS ESTIMATION

Directory of Open Access Journals (Sweden)

Y. Jia

2018-04-01

Full Text Available Global Navigation Satellite System Reflectometry (GNSS-R is based on the concept of receiving GPS signals reflected by the ground using a passive receiver. The receiver can be on the ground or installed on a small aircraft or UAV and collects the electromagnetic field scattered from the surface of the Earth. The received signals are then analyzed to determine the characteristics of the surface. Many research has been reported showing the capability of the GNSS-R technique. However, the roughness of the surface impacts the phase and amplitude of the received signals, which is still a worthwhile study. This paper presented a method can be used by GNSS-R to estimate the surface roughness. First, the data was calculated in the specular reflection with the assumption of a flat surface with different permittivity. Since the power reflectivity can be evaluated as the ratio of left-hand (LH reflected signal to the direct right-hand (RH signal. Then a semi-empirical roughness model was applied to the data for testing. The results showed the method can distinguish the water and the soil surface. The sensitivity of the parameters was also analyzed. It indicates this method for soil roughness estimation can be used by GNSS-R LH reflected signals. In the next step, several experiments need to be done for improving the model and exploring the way of the estimation.

a Method Using Gnss Lh-Reflected Signals for Soil Roughness Estimation

Science.gov (United States)

Jia, Y.; Li, W.; Chen, Y.; Lv, H.; Pei, Y.

2018-04-01

Global Navigation Satellite System Reflectometry (GNSS-R) is based on the concept of receiving GPS signals reflected by the ground using a passive receiver. The receiver can be on the ground or installed on a small aircraft or UAV and collects the electromagnetic field scattered from the surface of the Earth. The received signals are then analyzed to determine the characteristics of the surface. Many research has been reported showing the capability of the GNSS-R technique. However, the roughness of the surface impacts the phase and amplitude of the received signals, which is still a worthwhile study. This paper presented a method can be used by GNSS-R to estimate the surface roughness. First, the data was calculated in the specular reflection with the assumption of a flat surface with different permittivity. Since the power reflectivity can be evaluated as the ratio of left-hand (LH) reflected signal to the direct right-hand (RH) signal. Then a semi-empirical roughness model was applied to the data for testing. The results showed the method can distinguish the water and the soil surface. The sensitivity of the parameters was also analyzed. It indicates this method for soil roughness estimation can be used by GNSS-R LH reflected signals. In the next step, several experiments need to be done for improving the model and exploring the way of the estimation.

Leydig cell micronodules are a common finding in testicular biopsies from men with impaired spermatogenesis and are associated with decreased testosterone/LH ratio

DEFF Research Database (Denmark)

Holm, Mette; Rajpert-De Meyts, Ewa; Andersson, Anna-Maria

2003-01-01

To assess the biological significance of Leydig cell 'hyperplasia' in man, Leydig cell distribution, volume, and function were studied in patients with infertility or testicular cancer and in suddenly deceased controls. A total of 156 biopsies from 95 patients and 18 necropsies from 13 controls......), and were rare in testes from controls (median = 0, p = 0.02). The proportion of testicular tissue occupied by Leydig cells increased with decreasing spermatogenic capacity. In contrast, the total volume of Leydig cells per testis was roughly comparable irrespective of the histological pattern...... in the hyperstimulated testes, as reflected by an increased LH/testosterone ratio. In conclusion, Leydig cell micronodules were more frequent in biopsies with impaired spermatogenesis and associated with decreased ratios of testicular hormones to gonadotrophins. The presence of micronodules thus seems...

Avaliação da perda sanguínea na artroplastia total do joelho com e sem soltura do torniquete Blood loss in total knee arthroplasty with and without tourniquet release

Directory of Open Access Journals (Sweden)

José Wanderley Vasconcelos

2011-01-01

Full Text Available OBJETIVO: Avaliar a perda sanguínea em pacientes submetidos à artroplastia total cimentada do joelho com e sem soltura trans-operatória do torniquete pneumático para a hemostasia. MÉTODOS: Foram estudados 72 pacientes submetidos à artroplastia total, num total de 80 joelhos, divididos em dois grupos: Grupo 1 onde se manteve o torniquete pneumático até a sutura e curativo da ferida operatória, e Grupo 2 onde foi realizada a soltura do torniquete pneumático após a cimentação da prótese, com realização de hemostasia direta, antes da sutura e curativo. Os pacientes foram avaliados quanto ao sangramento pelo dreno de sucção e à contagem de hemoglobina e hematócrito, considerando os intervalos de duas, 24 e 48 horas de pós-operatório. RESULTADOS: Não houve diferença significante entre os dois grupos quanto ao sangramento pós-operatório e decréscimo dos parâmetros hematimétricos. Somente um paciente do Grupo 2 necessitou transfusão de concentrado de hemáceas no pós-operatório. CONCLUSÃO: O sangramento pós-operatório na ATJ mostrou-se igual com e sem a soltura do torniquete pneumático para a realização da hemostasia.OBJECTIVE: To evaluate blood loss in patients submitted to cemented total knee arthroplasty with and without perioperative tourniquet release for hemostasis. METHODS: Seventy-two patients (eighty knees were submitted to total knee arthroplasty, allocated into two groups: in Group 1, in which the pneumatic tourniquet was maintained until suture and dressing of the operated wound, and Group 2, in which the pneumatic tourniquet was released intraoperatively after cementing the prosthesis, with direct hemostasis, before the suture and dressing. The patients were evaluated for blood loss by the suction drain, and hemoglobin and hematocrit counts, at intervals of 2, 24 and 48 hours in the postoperative period tube. RESULTS: There was no significant difference between the groups in terms of postoperative blood

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

Science.gov (United States)

Dulka, Eden A; Moenter, Suzanne M

2017-11-01

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

Operational Issues in the Development of a Cost-Effective Reusable LOX/LH2 Engine

Science.gov (United States)

Ballard, Richard O.

2005-01-01

Contents include the following: SLI initiated under NASA Research Announcement (NRA) 8-30. Strategic Objectives. Make spaceflight safer (1 in 10000 mission LOV). Make spaceflight cheaper ($1000/lb payload). Two prototype LOX/LH2 engine systems funded under Cycle-1 of NRA8-30. COBRA (Pratt & Whitney / Aerojet). RS-83 (Rocketdyne).

GABAergic projections from lateral hypothalamus to paraventricular hypothalamic nucleus promote feeding

Science.gov (United States)

Lesions of the lateral hypothalamus (LH) cause hypophagia. However, activation of glutamatergic neurons in LH inhibits feeding. These results suggest a potential importance for other LH neurons in stimulating feeding. Our current study in mice showed that disruption of GABA release from adult LH GAB...

Anti-oxidant and hepatoprotective activities of total flavonoids of Indocalamus latifolius

Directory of Open Access Journals (Sweden)

Juan Tan

2015-12-01

Full Text Available The total flavonoids of Indocalamus latifolius were evaluated in term of their anti-oxidant and hepatoprotective activities. The results showed that in vitro hepatoprotective and anti-oxidant activities of total flavonoids at doses of 200 and 400 mg/kg and 100 mg/kg, respectively, were comparable to those of the known hepatoprotective drug silymarin at 100 mg/kg. These data were supplemented with histopathological studies of rat liver sections. Seven of the main flavonoid compounds purified by column chromatography using silica gel, sephadex LH-20 and develosil ODS, and determined to be vitexin, orientin, isovitexin, homoorientin, tricin, tricin-7-O-β-D-glucopyranoside and quercetin-3-O-glucopyranoside.

Total surface area change of Uranium dioxide fuel in function of burn-up and its impact on fission gas release during neutron irradiation for small, intermediate and high burn-up

International Nuclear Information System (INIS)

Szuta, M.

2011-01-01

In the early published papers it was observed that the fractional fission gas release from the specimen have a tendency to increase with the total surface area of the specimen - a fairy linear relationship was indicated. Moreover it was observed that the increase of total surface area during irradiation occurs in the result of connection the closed porosity with the open porosity what in turn causes the increase of fission gas release. These observations let us surmise that the process of knock-out release is the most significant process of fission gas release since its quantity is proportional to the total surface area. Review of the experiments related to the increase of total surface area in function of burn-up is presented in the paper. For very high burn-up the process of grain sub-division (polygonization) occurs under condition that the temperature of irradiated fuel lies below the temperature of grain re-crystallization. Simultaneously with the process of polygonization, the increase in local porosity and the decrease in local density in function of burn-up occurs, which leads to the increase of total surface area. It is suggested that the same processes take place in the transformed fuel as in the original fuel, with the difference that the total surface area is so big that the whole fuel can be treated as that affected by the knock-out process. This leads to explanation of the experimental data that for very high burn-up (>120 MWd/kgU) the concentration of xenon is constant. An explanation of the grain subdivision process in function of burn-up in the 'athermal' rim region in terms of total surface area, initial grain size and knock-out release is undertaken. Correlation of the threshold burn-up, the local fission gas concentration, local total surface area, initial and local grain size and burn-up in the rim region is expected. (author)

Tritium labeling of gonadotropin releasing hormone in its proline and histidine residues

International Nuclear Information System (INIS)

Klauschenz, E.; Bienert, M.; Egler, H.; Pleiss, U.; Niedrich, H.; Nikolics, K.

1981-01-01

3,4-dehydroproline9-GnRH prepared by solid phase peptide synthesis was tritiated catalytically under various conditions yielding 3H-GnRH with specific radioactivities in the range from 35-60 Ci/mmol and full LH releasing activity in vitro. Using palladium/alumina catalyst, the tritiation of the double bond occurs within ten minutes. Investigation of the tritium distribution between the amino acid residues showed a remarkably high incorporation of tritium into the histidine residue (11 to 37%). On the basis of this observation, the tritium labeling of GnRH and angiotensin I by direct catalytic hydrogen-tritium exchange was found to be useful for the labeling of these peptides at remarkably high specific radioactivity

Prenatal testosterone treatment alters LH and testosterone responsiveness to GnRH agonist in male sheep

Directory of Open Access Journals (Sweden)

SERGIO E RECABARREN

2007-01-01

Full Text Available Although evidence is accumulating that prenatal testosterone (T compromises reproductive function in the female, the effects of excess T in utero on the postnatal development of male reproductive function has not been studied. The aim of this study was to assess the influence of prenatal T excess on age-related changes in pituitary and gonadal responsiveness to GnRH in the male sheep. We used the GnRH agonist, leuprolide (10 µg/kg, as a pharmacologic challenge at 5, 10, 20 and 30 weeks of age. These time points correspond to early and late juvenile periods and the prepubertal and postpubertal periods of sexual development, respectively. LH and T were measured in blood samples collected before and after GnRH agonist administration. The area under the response curve (AUC of LH increased progressively in both controls and prenatal T-treated males from 5 to 20 weeks of age (P<0.01. The LH responses in prenatal T-treated males were lower at 20 and 30 weeks of age compared to controls (P<0.05. AUC-T increased progressively in control males from 5 through 30 weeks of age and prenatal T-treated males from 5 to 20 weeks of age. The T response in prenatal T-treated males was higher at 20 weeks compared to controls of same age but similar to controls and prenatal T-treated males at 30 weeks of age (P <0.05. Our findings suggest that prenatal T treatment advances the developmental trajectory of gonadal responsiveness to GnRH in male offspring

LUTEINIZING HORMONE SECRETION IN NELLORE HEIFER’S AFTER WEANING TO FIRST OVULATION CONCENTRAÇÃO DE LH EM NOVILHAS DA RAÇA NELORE DA DESMAMA À PRIMEIRA OVULAÇÃO

Directory of Open Access Journals (Sweden)

Daniel Cardoso

2009-12-01

Full Text Available

Development and validation of cryogenic foam insulation for LH2 subsonic transports

Science.gov (United States)

Anthony, F. M.; Colt, J. Z.; Helenbrook, R. G.

1981-01-01

Fourteen foam insulation specimens were tested. Some were plain foam while others contained flame retardants, chopped fiberglass reinforcement and/or vapor barriers. The thermal performance of the insulation was determined by measuring the rate at which LH2 boiled from an aluminum tank insulated with the test material. The test specimens were approximately 50 mm (2 in.) thick. They were structurally scaled so that the test cycle would duplicate the maximum thermal stresses predicted for the thicker insulation of an aircraft liquid hydrogen fuel tank during a typical subsonic flight. The simulated flight cycle of approximately 10 minutes duration heated the other insulation surface to 316 K (110 F) and cooled it to 226 K (20 F) while the inner insulation surface remained at liquid hydrogen temperature of 20 K (-423 F). Two urethane foam insulations exceeded the initial life goal of 2400 simulated flight cycles and sustained 4400 cycles with only minor damage. The addition of fiberglass reinforcement of flame retardant materials to an insulation degraded thermal performance and/or the life of the foam material. Installation of vapor barriers enhanced the structural integrity of the material but did not improve thermal performance. All of the foams tested were available materials; none were developed specifically for LH2 service.

Statistical theory of L-H transition in tokamaks

International Nuclear Information System (INIS)

Itoh, S.-I.; Itoh, K.; Toda, S.

2003-01-01

A statistical model for the bifurcation of the radial electric field E r is developed in view of describing L-H transitions of tokamak plasmas. Noise in micro fluctuations is shown to lead to random changes of E r , if a deterministic approach allows for more than one solution. The probability density function for and the ensemble average of E r are obtained. The L-to-H and the H-to-L transition probabilities are calculated, and the effective phase limit is derived. Due to the suppression of turbulence by shear in E r , the limit deviates from Maxwell's rule. The ensemble average of heat flux as well as that of E r do not show a hysteresis in contrast to the deterministic model. Experimental condition for observing the hysteresis is also addressed. (author)

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

Directory of Open Access Journals (Sweden)

Engin Türkgeldi

2015-06-01

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

The release of silver nanoparticles from commercial toothbrushes

Energy Technology Data Exchange (ETDEWEB)

Mackevica, Aiga, E-mail: aima@env.dtu.dk; Olsson, Mikael Emil; Hansen, Steffen Foss

2017-01-15

Highlights: • Ag and Ag nanoparticle release was measured from two types of toothbrushes. • Maximum release for entire intended product use period was 10 ng Ag per toothbrush. • Released Ag nanoparticles had median sizes from 42 to 47 nm. • Up to 2.8% of total Ag released was detected in nanoparticulate form. - Abstract: The use of silver nanoparticles (NPs) in commercial products has become increasingly common in the past decade, mostly due to their antimicrobial properties. Using Ag NP-containing articles may lead to particle release, which raises concern of human and environmental safety. The published literature addressing particle release is scarce, especially when it comes to quantifying exposure to NPs specifically. In this study, we have experimentally investigated the release of total Ag and Ag NP from commercially available toothbrushes i.e. biodegradable toothbrushes for adults and toothbrushes for children. Toothbrushes were immersed and abraded in tap water for 24 h corresponding to more than the whole intended usage time of a toothbrush. The total amount of released Ag was quantified by inductively coupled plasma—mass spectrometry (ICP-MS) analysis, and the Ag NPs were characterized by single particle ICP-MS and transmission electron microscopy (TEM). The median size of the released Ag NPs ranged from 42 to 47 nm, and the maximum total Ag release was 10.2 ng per toothbrush. The adult toothbrushes were generally releasing more total Ag and NPs than children toothbrushes. In conclusion, our results indicate that the use of Ag NP-impregnated toothbrushes can cause consumer as well as environmental exposure to Ag NPs.

The release of silver nanoparticles from commercial toothbrushes

International Nuclear Information System (INIS)

Mackevica, Aiga; Olsson, Mikael Emil; Hansen, Steffen Foss

2017-01-01

Highlights: • Ag and Ag nanoparticle release was measured from two types of toothbrushes. • Maximum release for entire intended product use period was 10 ng Ag per toothbrush. • Released Ag nanoparticles had median sizes from 42 to 47 nm. • Up to 2.8% of total Ag released was detected in nanoparticulate form. - Abstract: The use of silver nanoparticles (NPs) in commercial products has become increasingly common in the past decade, mostly due to their antimicrobial properties. Using Ag NP-containing articles may lead to particle release, which raises concern of human and environmental safety. The published literature addressing particle release is scarce, especially when it comes to quantifying exposure to NPs specifically. In this study, we have experimentally investigated the release of total Ag and Ag NP from commercially available toothbrushes i.e. biodegradable toothbrushes for adults and toothbrushes for children. Toothbrushes were immersed and abraded in tap water for 24 h corresponding to more than the whole intended usage time of a toothbrush. The total amount of released Ag was quantified by inductively coupled plasma—mass spectrometry (ICP-MS) analysis, and the Ag NPs were characterized by single particle ICP-MS and transmission electron microscopy (TEM). The median size of the released Ag NPs ranged from 42 to 47 nm, and the maximum total Ag release was 10.2 ng per toothbrush. The adult toothbrushes were generally releasing more total Ag and NPs than children toothbrushes. In conclusion, our results indicate that the use of Ag NP-impregnated toothbrushes can cause consumer as well as environmental exposure to Ag NPs.

Balance of the stored energies sustained by the internal and edge transport barriers and effects of ELMs and L-H transitions in JT-60U

International Nuclear Information System (INIS)

Kamada, Y.; Yoshida, M.; Sakamoto, Y.; Koide, Y.; Oyama, N.; Urano, H.; Kamiya, K.; Suzuki, T.; Isayama, A.

2009-01-01

To understand key physics processes determining radial profiles of the kinetic plasma parameters in the advanced tokamak operation scenarios, correlations between the edge transport barrier (ETB) and the internal transport barrier (ITB) have been studied in the JT-60U tokamak device. It has been found that the edge pedestal poloidal beta, β p -ped, increases almost linearly with the total poloidal beta, β p -tot, over a wide range of the plasma current for type I ELMing H-mode plasmas, and this dependence becomes stronger with increasing triangularity. This dependence is not due to the profile stiffness, since the dependence is the same regardless of the existence of ITB. As the stored energy inside the ITB-foot radius (W ITB ) increases, the total thermal stored energy (W th ) increases and then the pedestal stored energy (W ped ) increases. On the other hand, as W ped increases, the ELM penetration expands more inwards and finally reaches the ITB-foot radius. At this situation, the ITB-foot radius cannot move outwards because of the erosion by ELMs. Then the fractions of W ITB /W th and W ped /W th become almost constant. It has also been found that the type I ELM expels/decreases the edge toroidal momentum larger than the edge ion thermal energy. The ELM penetration for the toroidal rotation tends to be deeper than that for the ion temperature and can exceed the ITB-foot radius. The ELM penetration is deeper for CO-rotating plasmas than CTR rotating plasmas. In both cases, the ELM penetration is deeper in the order of the toroidal rotation (V t ), the ion temperature (T i ) and then the electron temperature (T e ). The L-H transition also changes the V t profile more significantly than the T i profile. At the L-H transition, the pedestal V t shifts into the CTR-direction deeply and suddenly without a change in T i , and then the pedestal V t grows further together with a growth of the pedestal T i in a slower timescale. Such changes in V t by ELMs and L-H

Resonance Raman and surface-enhanced resonance Raman spectra of LH2 antenna complex from Rhodobacter sphaeroides and Ectothiorhodospira sp. excited in the Qx and Qy transitions.

Science.gov (United States)

Chumanov, G; Picorel, R; Ortiz de Zarate, I; Cotton, T M; Seibert, M

2000-05-01

Well-resolved vibrational spectra of LH2 complex isolated from two photosynthetic bacteria, Rhodobacter sphaeroides and Ectothiorhodospira sp., were obtained using surface-enhanced resonance Raman scattering (SERRS) exciting into the Qx and the Qy transitions of bacteriochlorophyll a. High-quality SERRS spectra in the Qy region were accessible because the strong fluorescence background was quenched near the roughened Ag surface. A comparison of the spectra obtained with 590 nm and 752 nm excitation in the mid- and low-frequency regions revealed spectral differences between the two LH2 complexes as well as between the LH2 complexes and isolated bacteriochlorophyll a. Because peripheral modes of pigments contribute mainly to the low-frequency spectral region, frequencies and intensities of many vibrational bands in this region are affected by interactions with the protein. The results demonstrate that the microenvironment surrounding the pigments within the two LH2 complexes is somewhat different, despite the fact that the complexes exhibit similar electronic absorption spectra. These differences are most probably due to specific pigment-pigment and pigment-protein interactions within the LH2 complexes, and the approach might be useful for addressing subtle static and dynamic structural variances between pigment-protein complexes from different sources or in complexes altered chemically or genetically.

Quantum coherence spectroscopy reveals complex dynamics in bacterial light-harvesting complex 2 (LH2).

Science.gov (United States)

Harel, Elad; Engel, Gregory S

2012-01-17

Light-harvesting antenna complexes transfer energy from sunlight to photosynthetic reaction centers where charge separation drives cellular metabolism. The process through which pigments transfer excitation energy involves a complex choreography of coherent and incoherent processes mediated by the surrounding protein and solvent environment. The recent discovery of coherent dynamics in photosynthetic light-harvesting antennae has motivated many theoretical models exploring effects of interference in energy transfer phenomena. In this work, we provide experimental evidence of long-lived quantum coherence between the spectrally separated B800 and B850 rings of the light-harvesting complex 2 (LH2) of purple bacteria. Spectrally resolved maps of the detuning, dephasing, and the amplitude of electronic coupling between excitons reveal that different relaxation pathways act in concert for optimal transfer efficiency. Furthermore, maps of the phase of the signal suggest that quantum mechanical interference between different energy transfer pathways may be important even at ambient temperature. Such interference at a product state has already been shown to enhance the quantum efficiency of transfer in theoretical models of closed loop systems such as LH2.

The effects of serum concentration of androgens, LH and IGF1 in early follicular phase on follicular growth parameters and pregnancy rate

Directory of Open Access Journals (Sweden)

Zahra Raoofi

2016-03-01

Full Text Available Objective: Many studies have showed the role of androgens on the follicular maturation. The present study investigated the effect of serum concentration of androgens, LH and IGF1 in the early follicular phase on the results of the ovulation induction (I/O and intrauterine insemination (IUI cycles. Materials and methods: This prospective observational cross-sectional study was carried out in the infertility department of a university hospital in Tehran, Iran. The case’s selection was based on the inclusion and exclusion criteria and was nonrandomized. 59 patients under the age of 45 who were candidate for induction ovulation (I/O or intrauterine insemination were included. The inclusion criteria consist of infertility for at least one year and at least one open tube in HSG. Patients were excluded if they had polycystic ovary syndrome (PCOS or endometriosis. The serum concentration of androgens (testosterone, dehydroepiandrosterone and androstenedione, LH and IGF1 was measured on the third day of menstruation. Clomiphene and human menopausal gonadotropin (HMG were drugs of induction ovulation. Human chorionic gonadotropin (HCG was injected when there was at least one follicle with the size of (18 mm. IUI was done 36 h later for eligible patients and the relation of concentration of androgens, LH and IGF1 with follicular growth parameters and pregnancy rate was analyzed. Results: There was not any statistical significant link between the number and size of follicles with levels of free testosterone, dehydroepiandrosterone, androstenedione, IGF1 and LH. There was not any statistical significant link between the number of follicles in the ovaries and levels of testosterone (P = 0.090 and r = 0.223, dehydroepiandrosterone (P = 0.642 and r = 0.062 and androstenedione (P = 0.526 and r = 0.084, IGF1 (P = 0.470 and r = 0.096 and LH (P = 0.446 and r = 0.102. There was not any statistical significant link between the mean follicular

High pressure near infrared study of the mutated light-harvesting complex LH2

Directory of Open Access Journals (Sweden)

Braun P.

2005-01-01

Full Text Available The pressure sensitivities of the near infrared spectra of the light-harvesting (LH2 complex and a mutant complex with a simplified BChl-B850 binding pocket were compared. In the mutant an abrupt change in the spectral properties occurred at 250 MPa, which was not observed with the native sample. Increased disorder due to collapse of the chromophore pocket is suggested.

Cetrorelix suppresses the preovulatory LH surge and ovulation induced by ovulation-inducing factor (OIF) present in llama seminal plasma.

Science.gov (United States)

Silva, Mauricio E; Smulders, Juan P; Guerra, Monserrat; Valderrama, Ximena P; Letelier, Claudia; Adams, Gregg P; Ratto, Marcelo H

2011-05-30

The purpose of the study was to determine if the effect of llama OIF on LH secretion is mediated by stimulation of the hypothalamus or pituitary gland. Using a 2-by-2 factorial design to examine the effects of OIF vs GnRH with or without a GnRH antagonist, llamas with a growing ovarian follicle greater than or equal to 8 mm were assigned randomly to four groups (n = 7 per group) and a) pre-treated with 1.5 mg of GnRH antagonist (cetrorelix acetate) followed by 1 mg of purified llama OIF, b) pre-treated with 1.5 mg of cetrorelix followed by 50 micrograms of GnRH, c) pre-treated with a placebo (2 ml of saline) followed by 1 mg of purified llama OIF or d) pre-treated with a placebo (2 ml of saline) followed by 50 micrograms of GnRH. Pre-treatment with cetrorelix or saline was given as a single slow intravenous dose 2 hours before intramuscular administration of either GnRH or OIF. Blood samples for LH measurement were taken every 15 minutes from 1.5 hours before to 8 hours after treatment. The ovaries were examined by ultrasonography to detect ovulation and CL formation. Blood samples for progesterone measurement were taken every-other-day from Day 0 (day of treatment) to Day 16. Ovulation rate was not different (P = 0.89) between placebo+GnRH (86%) and placebo+OIF groups (100%); however, no ovulations were detected in llamas pre-treated with cetrorelix. Plasma LH concentrations surged (P llamas suggesting that LH secretion is modulated by a direct or indirect effect of OIF on GnRH neurons in the hypothalamus.

Luteinizing hormone pulsatility in females following radiation therapy for central nervous system malignancies

International Nuclear Information System (INIS)

Brasacchio, R.A.; Constine, L.S.; Woolf, P.; Raubertas, R.F.; Veldhuis, J.D.; Muhs, A.G.

1997-01-01

patient/volunteer was injected with GnRH (25 ug) to demonstrate pituitary LH responsiveness. Deconvolution analysis was applied to each series of 72 measurements to calculate the following summary values: the number of LH pulses, their mean amplitude, the total amount of hormone released, and the metabolic clearance rate. Results: Four controls and four patients were studied. The patients had a mean age of 13.5 years at the time of RT (range 16-47), and were studied at a median of 9.8 years (range 0.7-13.2) years) following RT. The median dose delivered to the H/P-A was 57.9 Gy (range 44.4-69.1) Gy). Fig 1 shows normal LH levels and pulsatility in a 26 year-old control with normal estrogen levels and menstruation. MCP/NAL administration appeared to blunt the LH response to GnRH. Fig 2 shows suppressed LH levels and absent LH pulsatility in a 20.5 year old amenorrheic, hypoestrogenemic female irradiated 9.2 years previously to the H/P-A for a low-grade astrocytoma of the right temporal lobe. MCP/NAL administration failed to correct the defect. The response of LH to GnRH stimulation was intact, although decreased, and again not altered by administration of MCP or NAL. Deconvolution analysis suggested that LH burst amplitude (mIU/ml/min) and possibly secretion per burst (mIU/ml), and production rate (mIU/ml/12h) were abnormal in the patient group. Further results of deconvolution analysis will be presented. Conclusion: Preliminary analysis suggests that patients irradiated to the H/P-A who develop oligo-amenorrhea have impaired hypothalamic control of LH pulsatility. Innate pituitary function appears to be preserved. Intervention in the adrenergic or opiate pathways mediating the H/P-A was not corrective. Further exploration of the nature of the H/P-A injury, which may suggest pharmacologic interventions to reverse the oligo-amenorrhea seen in these patients is in progress

Possible applications of RIA of LH and FSH in diagnosis of Stein-Leventhal syndrome

International Nuclear Information System (INIS)

Zenisek, L.; Talas, M.; Stehlikova, J.; Fingerova, H.; Duskova, M.

1981-01-01

LH determination in the serum significantly assists in diagnosing polycystic ovaries. Values exceeding 22 mIU/ml serum are indicative of a typical picture of polycystic ovaries similar to those found in the Stein-Leventhal syndrome. Lower levels indicate an atypical picture of polycystic ovaries or low-cyst ovary degeneration. FSH level cannot be used for this diagnosis. (author)

Possible applications of RIA of LH and FSH in diagnosis of Stein-Leventhal syndrome

Energy Technology Data Exchange (ETDEWEB)

Zenisek, L.; Talas, M.; Stehlikova, J.; Fingerova, H.; Duskova, M.

1981-01-01

LH determination in the serum significantly assists in diagnosing polycystic ovaries. Values exceeding 22 mIU/ml serum are indicative of a typical picture of polycystic ovaries similar to those found in the Stein-Leventhal syndrome. Lower levels indicate an atypical picture of polycystic ovaries or low-cyst ovary degeneration. FSH level cannot be used for this diagnosis.

Statistical theory of L-H transition in tokamaks

Energy Technology Data Exchange (ETDEWEB)

Itoh, S.-I. [Kyushu Univ., Research Institute for Applied Mechanics, Kasuga, Fukuoka (Japan); Itoh, K.; Toda, S. [National Inst. for Fusion Science, Toki, Gifu (Japan)

2003-01-01

A statistical model for the bifurcation of the radial electric field E{sub r} is developed in view of describing L-H transitions of tokamak plasmas. Noise in micro fluctuations is shown to lead to random changes of E{sub r}, if a deterministic approach allows for more than one solution. The probability density function for and the ensemble average of E{sub r} are obtained. The L-to-H and the H-to-L transition probabilities are calculated, and the effective phase limit is derived. Due to the suppression of turbulence by shear in E{sub r}, the limit deviates from Maxwell's rule. The ensemble average of heat flux as well as that of E{sub r} do not show a hysteresis in contrast to the deterministic model. Experimental condition for observing the hysteresis is also addressed. (author)

In silico predictions of LH2 ring sizes from the crystal structure of a single subunit using molecular dynamics simulations.

Science.gov (United States)

Janosi, Lorant; Keer, Harindar; Cogdell, Richard J; Ritz, Thorsten; Kosztin, Ioan

2011-07-01

Most of the currently known light-harvesting complexes 2 (LH2) rings are formed by 8 or 9 subunits. As of now, questions like "what factors govern the LH2 ring size?" and "are there other ring sizes possible?" remain largely unanswered. Here, we investigate by means of molecular dynamics (MD) simulations and stochastic modeling the possibility of predicting the size of an LH2 ring from the sole knowledge of the high resolution crystal structure of a single subunit. Starting with single subunits of two LH2 rings with known size, that is, an 8-ring from Rs. moliscianum (MOLI) and a 9-ring from Rps. acidophila (ACI), and one with unknown size (referred to as X), we build atomic models of subunit dimers corresponding to assumed 8-, 9-, and 10-ring geometries. After inserting each of the dimers into a lipid-water environment, we determine the preferred angle between the corresponding subunits by three methods: (1) energy minimization, (2) free MD simulations, and (3) potential of mean force calculations. We find that the results from all three methods are consistent with each other, and when taken together, it allows one to predict with reasonable level of confidence the sizes of the corresponding ring structures. One finds that X and ACI very likely form a 9-ring, while MOLI is more likely to form an 8-ring than a 9-ring. Finally, we discuss both the merits and limitations of all three prediction methods. Copyright © 2011 Wiley-Liss, Inc.

Effects of human chorionic gonadotropin combined with clomiphene on Serum E2, FSH, LH and PRL levels in patients with polycystic ovarian syndrome.

Science.gov (United States)

Yonggang, Huang; Xiaosheng, Lu; Zhaoxia, Huang; Yilu, Chen; Jiqiang, Lv; Huina, Zhang

2017-02-01

Effects of human chorionic gonadotropin combined with clomiphene on serum E 2 , FSH, LH and PRL levels in patients with polycystic ovarian syndrome were analyzed. 90 patients with polycystic ovarian syndrome treated from January 2015 to March 2016 were randomly and evenly divided into control group and observation group. Patients in the control group were only treated with clomiphene. On the basis of the treatment in control group, human chorionic gonadotropin was added in the treatment of observation group. The changes of E 2 , FSH, LH, PRL levels were compared between two groups before and after the treatment. Clinical curative effects of patients in the two groups was evaluated. Adverse reactions during treatment in two groups were observed and recorded. The incidence of adverse reactions was calculated. Serum E 2 , FSH, LH and PRL levels in the two groups decreased significantly after treatment compared with that before treatment. The difference is statistical significant ( P   0.05). Combined use of human chorionic gonadotropin can significantly reduce serum E 2 , FSH, LH and PRL levels, improve clinical curative effects and reduce the incidence of adverse reactions. Human chorionic gonadotropin has high application value on the treatment of polycystic ovary syndrome.

Impact of the lipid bilayer on energy transfer kinetics in the photosynthetic protein LH2† †Electronic supplementary information (ESI) available. See DOI: 10.1039/c7sc04814a

Science.gov (United States)

Ogren, John I.; Tong, Ashley L.; Gordon, Samuel C.; Chenu, Aurélia; Lu, Yue; Blankenship, Robert E.; Cao, Jianshu

2018-01-01

Photosynthetic purple bacteria convert solar energy to chemical energy with near unity quantum efficiency. The light-harvesting process begins with absorption of solar energy by an antenna protein called Light-Harvesting Complex 2 (LH2). Energy is subsequently transferred within LH2 and then through a network of additional light-harvesting proteins to a central location, termed the reaction center, where charge separation occurs. The energy transfer dynamics of LH2 are highly sensitive to intermolecular distances and relative organizations. As a result, minor structural perturbations can cause significant changes in these dynamics. Previous experiments have primarily been performed in two ways. One uses non-native samples where LH2 is solubilized in detergent, which can alter protein structure. The other uses complex membranes that contain multiple proteins within a large lipid area, which make it difficult to identify and distinguish perturbations caused by protein–protein interactions and lipid–protein interactions. Here, we introduce the use of the biochemical platform of model membrane discs to study the energy transfer dynamics of photosynthetic light-harvesting complexes in a near-native environment. We incorporate a single LH2 from Rhodobacter sphaeroides into membrane discs that provide a spectroscopically amenable sample in an environment more physiological than detergent but less complex than traditional membranes. This provides a simplified system to understand an individual protein and how the lipid–protein interaction affects energy transfer dynamics. We compare the energy transfer rates of detergent-solubilized LH2 with those of LH2 in membrane discs using transient absorption spectroscopy and transient absorption anisotropy. For one key energy transfer step in LH2, we observe a 30% enhancement of the rate for LH2 in membrane discs compared to that in detergent. Based on experimental results and theoretical modeling, we attribute this difference

Total petroleum hydrocarbon degradation by hybrid electrobiochemical reactor in oilfield produced water

International Nuclear Information System (INIS)

Mousa, Ibrahim E.

2016-01-01

The crude oil drilling and extraction operations are aimed to maximize the production may be counterbalanced by the huge production of contaminated produced water (PW). PW is conventionally treated through different physical, chemical, and biological technologies. The efficiency of suggested hybrid electrobiochemical (EBC) methods for the simultaneous removal of total petroleum hydrocarbon (TPH) and sulfate from PW generated by petroleum industry is studied. Also, the factors that affect the stability of PW quality are investigated. The results indicated that the effect of biological treatment is very important to keep control of the electrochemical by-products and more TPH removal in the EBC system. The maximum TPH and sulfate removal efficiency was achieved 75% and 25.3%, respectively when the detention time was about 5.1 min and the energy consumption was 32.6 mA/cm 2 . However, a slight increasing in total bacterial count was observed when the EBC compact unit worked at a flow rate of average 20 L/h. Pseudo steady state was achieved after 30 min of current application in the solution. Also, the results of the study indicate that when the current intensity was increased above optimum level, no significant results occurred due to the release of gases. - Highlights: • The hybrid electrolytic biological cell was used for degradation of oilfield produced water. • Decomposition of Total Petroleum Hydrocarbon with or without the biofilter. • High saline water with the high chloride and sulfate ions content treatment. • The removal of electrochemical by-products is a phase change technique that requires the maintenance the biofilm on the filter media, which is sensitive and a complex operation. • Biofilter is efficient for the degradation of PW bye products, the critical drawback to their utility in full-scale operations is high TDS water content and detention time of treatment.

Dynamics of exciton relaxation in LH2 antenna probed by multipulse nonlinear spectroscopy.

Science.gov (United States)

Novoderezhkin, Vladimir I; Cohen Stuart, Thomas A; van Grondelle, Rienk

2011-04-28

We explain the relaxation dynamics in the LH2-B850 antenna as revealed by multipulse pump-dump-probe spectroscopy (Th. A. Cohen Stuart, M. Vengris, V. I. Novoderezhkin, R. J. Cogdell, C. N. Hunter, R. van Grondelle, submitted). The theory of pump-dump-probe response is evaluated using the doorway-window approach in combination with the modified Redfield theory. We demonstrate that a simultaneous fit of linear spectra, pump-probe, and pump-dump-probe kinetics can be obtained at a quantitative level using the disordered exciton model, which is essentially the same as used to model the spectral fluctuations in single LH2 complexes (Novoderezhkin, V.; Rutkauskas, D.; van Grondelle, R. Biophys. J. 2006, 90, 2890). The present studies suggest that the observed relaxation rates are strongly dependent on the realization of the disorder. A big spread of the rates (exceeding 3 orders of magnitude) is correlated with the disorder-induced changes in delocalization length and overlap of the exciton wave functions. We conclude that the bulk kinetics reflect a superposition of many pathways corresponding to different physical limits of energy transfer, varying from sub-20 fs relaxation between delocalized and highly spatially overlapping exciton states to >20 ps jumps between states localized at the opposite sides of the ring.

Transport-driven scrape-off layer flows and the x-point dependence of the L-H power threshold in Alcator C-Moda)

Science.gov (United States)

LaBombard, B.; Rice, J. E.; Hubbard, A. E.; Hughes, J. W.; Greenwald, M.; Granetz, R. S.; Irby, J. H.; Lin, Y.; Lipschultz, B.; Marmar, E. S.; Marr, K.; Mossessian, D.; Parker, R.; Rowan, W.; Smick, N.; Snipes, J. A.; Terry, J. L.; Wolfe, S. M.; Wukitch, S. J.

2005-05-01

Factor of ˜2 higher power thresholds for low- to high-confinement mode transitions (L-H) with unfavorable x-point topologies in Alcator C-Mod [Phys. Plasmas 1, 1511 (1994)] are linked to flow boundary conditions imposed by the scrape-off layer (SOL). Ballooning-like transport drives flow along magnetic field lines from low- to high-field regions with toroidal direction dependent on upper/lower x-point balance; the toroidal rotation of the confined plasma responds, exhibiting a strong counter-current rotation when B ×∇B points away from the x point. Increased auxiliary heating power (rf, no momentum input) leads to an L-H transition at approximately twice the edge electron pressure gradient when B ×∇B points away. As gradients rise prior to the transition, toroidal rotation ramps toward the co-current direction; the H mode is seen when the counter-current rotation imposed by the SOL flow becomes compensated. Remarkably, L-H thresholds in lower-limited discharges are identical to lower x-point discharges; SOL flows are also found similar, suggesting a connection.

The simultaneous measurements of core and outer core density fluctuations in L-H transition using CO2 laser collective scattering diagnostic in the EAST superconducting tokamak

International Nuclear Information System (INIS)

Cao, G.M.; Li, Y.D.; Zhang, X.D.; Sun, P.J.; Hu, L.Q.; Li, J.G.; Wu, G.J.

2013-01-01

The H-mode is the projected basic operation scenario for the ITER tokamak. The turbulence de-correlation by the synergistic effect of zonal flow and equilibrium ExB flow shear is believed to be the reason for L-H transition, however, the detailed physical mechanism has not been identified so far. Tangential multi-channel CO 2 laser collective scattering diagnostic system (mainly k r measurement) was first installed to investigate electron density fluctuations on EAST tokamak. The measurements in a spontaneous dithering L-H transition show that in core plasma (0 < r/a < 0.5) the low-frequency fluctuations strengthen greatly before L-H transition; meanwhile in outer core plasma (0.2 < r/a < 1) the low-frequency fluctuations strengthen slightly. Bispectral analysis reveals that the coupling strength between low- and high-frequency fluctuations in both core and outer core plasma strengthens greatly before the transition, but the latter is greater than the former. The results indicate that the low-frequency fluctuations of the core and outer core plasma play active, but different, roles in the spontaneous L-H transition. (author)

[Spermatogenesis of pulsatile gonadotropin-releasing hormone infusion versus gonadotropin therapy in male idiopathic hypogonadotropic hypogonadism].

Science.gov (United States)

Huang, Bingkun; Mao, Jiangfeng; Xu, Hongli; Wang, Xi; Liu, Zhaoxiang; Nie, Min; Wu, Xueyan

2015-05-26

To compare the efficacies of pulsatile gonadotropin-releasing hormone (GnRH) versus human chorionic gonadotropin/human menopausal gonadotropin (HCG/HMG) for spermatogenesis in male idiopathic hypogonadotropic hypogonadism (IHH). For this retrospective study, a total of 92 male IHH outpatients from May 2010 to October 2014 were recruited and categorized into GnRH (n = 40) and HCG/HMG (n = 52) groups. Each subject selected one specific therapy voluntarily. The gonadotropin levels were measured in the first week and monthly post-treatment in GnRH group. And serum total testosterone (TT), testicular volume (TV) and rate of spermatogenesis were observed monthly post-treatment in two groups. Spermatogenesis, TT and TV were compared between two groups. All IHH patients were treated for over 3 months. The median follow-up periods in GnRH and HCG/HMG groups was 8.2 (3.0-18.4) and 9.2 (3.0-18.6) months respectively (P = 0.413). In GnRH group, LH ((0.5 ± 0.6) vs (3.4 ± 2.4) U/L, P treatment. In GnRH group, at the end of follow-up, TT ((1.0 ± 1.0) vs (7.4 ± 5.2) nmol/L, P treatment time for initial sperm appearance than HCG/HMG group ((6.5 ± 3.1) vs (10.8 ± 3.7) months, P = 0.001). Pulsatile GnRH requires a shorter time for initiation of spermatogenesis than gonadotropin therapy in IHH male patients.

Development of advanced materials composites for use as insulations for LH2 tanks

Science.gov (United States)

Lemons, C. R.; Salmassy, O. K.

1973-01-01

A study of thread-reinforced polyurethane foam and glass fabric liner, serving as internally bonded insulation for space shuttle LH2 tanks, is reported. Emphasis was placed on an insulation system capable of reentry and multiple reuse in the shuttle environment. The optimized manufacturing parameters associated with each element of the composite are established and the results, showing successful completion of subscale system evaluation tests using the shuttle flight environmental requirements, are given.

Regulation of LH/FSH expression by secretoglobin 3A2 in the mouse pituitary gland.

Science.gov (United States)

Miyano, Yuki; Tahara, Shigeyuki; Sakata, Ichiro; Sakai, Takafumi; Abe, Hiroyuki; Kimura, Shioko; Kurotani, Reiko

2014-04-01

Secretoglobin (SCGB) 3A2 was originally identified as a downstream target for the homeodomain transcription factor NKX2-1 in the lung. NKX2-1 plays a role in the genesis and expression of genes in the thyroid, lung and ventral forebrain; Nkx2-1-null mice have no thyroid and pituitary and severely hypoplastic lungs and hypothalamus. To demonstrate whether SCGB3A2 plays any role in pituitary hormone production, NKX2-1 and SCGB3A2 expression in the mouse pituitary gland was examined by immunohistochemical analysis and RT-PCR. NKX2-1 was localized in the posterior pituitary lobe, whereas SCGB3A2 was observed in both anterior and posterior lobes as shown by immunohistochemistry and RT-PCR. Expression of CCAAT-enhancer binding proteins (C/EBPs), which regulate mouse Scgb3a2 transcription, was also examined by RT-PCR. C/EBPβ, γ, δ and ζ were expressed in the adult mouse pituitary gland. SCGB3A2 was expressed in the anterior and posterior lobes from postnatal days 1 and 5, respectively and the areas where SCGB3A2 expression was found coincided with the area where FSH-secreting cells were found. Double-staining for SCGB3A2 and pituitary hormones revealed that SCGB3A2 was mainly localized in gonadotrophs in 49 % of FSH-secreting cells and 47 % of LH-secreting cells. In addition, SCGB3A2 dramatically inhibited LH and FSH mRNA expression in rat pituitary primary cell cultures. These results suggest that SCGB3A2 regulates FSH/LH production in the anterior pituitary lobe and that transcription factors other than NKX2-1 may regulate SCGB3A2 expression.

Mechanized Sephadex LH-20 multiple column chromatography as a prerequisite for automated multi-steroid radioimmunoassays

International Nuclear Information System (INIS)

Sippell, W.G.; Bidlingmaier, F.; Knorr, D.

1978-01-01

To establish a procedure for the simultaneous determination of all major corticosteroid hormones and their immediate biological precursors in the same plasma sample, two different mechanized methods for the simultaneous isolation of aldosterone (A), corticosterone (B), 11-deoxycorticosterone (DOC), progesterone (P), 17-hydroxyprogesterone (17-OHP), 11-deoxycortisol (S), cortisol (F) and cortisone (E) from the methylene chloride extracts of 0.1 to 2.0ml plasma samples have been developed. In method I, steroids are separated with methylene chloride:methanol=98:2 as solvent system on 60-cm Sephadex LH-20 columns, up to eight of which are eluted in parallel using a multi-channel peristaltic pump and individual flow-rate control (40ml/h) by capillary valves and micro-flowmeters. Method II, on the other hand, utilizes the same solvent system on ten 75-cm LH-20 columns which are eluted in reversed flow simultaneously by a ten-channel, double-piston pump that precisely maintains an elution flow rate of 40ml/h in every column. In both methods, eluate fractions of each of the isolated steroids are automatically pooled and collected from all parallel columns by one programmable linear fraction collector. As a result of the high reproducibility of the elution patterns, both between different parallel columns and between 30 to 40 consecutive elutions, mean recoveries of tritiated steroids including extraction are 60 to 84% after a single separation and still over 50% after an additional separation on 40-cm LH-20 columns, with coefficients of variation below 15% (method II). Thus, the eight steroids can be completely isolated from each of ten plasma extracts within 3 to 4 hours, yielding 80 samples readily prepared for subsequent quantitation by radioimmunoassay. (author)

Persistent X-Ray Emission from ASASSN-15lh: Massive Ejecta and Pre-SLSN Dense Wind?

Science.gov (United States)

Huang, Yan; Li, Zhuo

2018-06-01

The persistent soft X-ray emission from the location of the most luminous supernova (SN) so far, ASASSN-15lh (or SN 2015L), with L∼ {10}42 {erg} {{{s}}}-1, is puzzling. We show that it can be explained by radiation from electrons accelerated by the SN shock inverse-Compton scattering the intense UV photons. The non-detection in radio requires strong free–free absorption in the dense medium. In these interpretations, the circumstellar medium is derived to be a wind (n ∝ R ‑2) with mass-loss rate of \\dot{{M}}≳ 3× {10}-3{{M}}ȯ ({{v}}{{w}}/{10}3 {{k}}{{m}} {{{s}}}-1) {{{y}}{{r}}}-1, and the initial velocity of the bulk SN ejecta is ≲ 0.02c. These constraints imply a massive ejecta mass of ≳ 60({E}0/2× {10}52 {erg}){M}ȯ in ASASSN-15lh, and a strong wind ejected by the progenitor star within ∼ 8{({v}{{w}}/{10}3{km}{{{s}}}-1)}-1 yr before explosion.

Latent Heating Profiles Derived from ARM Radar Observations in MC3E and GoAmazon Field Campaigns

Science.gov (United States)

Min, Q.; Li, R.; Mu, Z.; Giangrande, S. E.; Wang, Y.

2016-12-01

Atmosphere latent heating (LH) is released through water phase change processes in the atmosphere. There is a physical connection between LH rate and updraft velocity (ω) inside clouds. In this study, we develop a new LH algorithm based on a quantified LH-ω relationship found in cloud resolving model (CRM) simulations. The self-consistency check with CRM simulations shows that the retrievals correctly replicate the main features of LH profiles, including their total and individual components (i.e. condensation-evaporation heating rate, deposition-sublimation heating rate, and freezing-melting heating rate). Further, the algorithm is applied to real cases from the DOE-ARM MC3E and GoAmazon2014/6 Field Campaigns using available UHF (915 and 1290 MHz) zenith radar retrievals of vertical velocity and rain rate as input. The retrieved LH profiles in the deep convective rains show positive heating throughout the column, the LH profiles in the stratiform rains with well-defined bright-band showing clear dipole patterns with positive heating above and negative cooling below the freezing level. The altitudes of maximum heating in the widespread stratiform regimes are clearly higher than those found within deep convective regions. Overall, these Latent heating rate profiles, as an important geophysical quantity of interest, can provide useful climate diagnostic data, and ultimately, constraints for model-based analyses of large-scale heating distributions.

Validation of the LH antenna code ALOHA against Tore Supra experiments

International Nuclear Information System (INIS)

Hillairet, J.; Ekedahl, A.; Kocan, M.; Gunn, J. P.; Goniche, M.

2009-01-01

Comparisons between ALOHA code predictions and experimental measurements of reflection coefficients for the two different Lower Hybrid Current Drive (LHCD) antennas (named C2 and C3) in Tore Supra are presented. A large variation of density in front of the antennas was obtained by varying the distance between the plasma and the antennas. Low power ( 2 ) was used in order to avoid non-linear effects on the wave coupling. Results obtained with ALOHA are in good agreement with the experimental measurements for both Tore Supra antennas and show that ALOHA is an efficient LH predictive tool.

Turbulence simulations of X point physics on the L-H transitions

International Nuclear Information System (INIS)

Xu, X.Q.; Cohen, R.H.; Nevins, W.M.

2001-01-01

We show that the resistive X-point mode is the dominant mode in boundary plasmas in X-point divertor geometry. The poloidal fluctuation phase velocity from the simulation results of the resistive X-point turbulence shows experimentally measured structure across separatrix in many fusion devices. The fluctuation phase velocity is larger than ExB velocity both in L and H mode phases. We also demonstrate that there is a strong poloidal asymmetry of particle flux in the proximity of the separatrix. Turbulence suppression in the L-H transition results when sources of energy and particles drive sufficient gradients as in the experiments. (author)

Relaxation dynamics of the LH2 complex from a photosynthetic purple bacterium Thiorhodospira sibirica studied by the near-IR femtosecond pump-probe method

International Nuclear Information System (INIS)

Razjivin, A P; Pishchal'nikov, R Yu; Kozlovskii, V S; Kompanets, V O; Chekalin, Sergei V; Moskalenko, A A; Makhneva, Z K

2005-01-01

Photoinduced changes in the absorption spectrum of the LH2 (B800-830-850) complex from a Thiorhodospira sibirica (Trs. sibirica) bacterium are studied by the pump-probe method. The complex has the anomalous absorption spectrum exhibiting three bands in the near-IR region at 793, 826.5, and 846.5 nm. At room temperature, the excitation energy transfer from the B800, B830, and B859 bands was detected with the time constants τ 1 ∼0.5 ps, τ 2 ∼2.5 ps, and τ 3 of the order of a few hundreds of picoseconds, respectively. A rapid energy transfer from the B830 band compared to energy transfer from the B850 band (τ 2 ||τ 3 ) suggests that all the three bands belong to the same complex (i.e., that the LH2 complex from Trs. sibirica is homogeneous). A slower energy transfer (by three - five times) from the B830 band of the LH2 complex from Trs. sibirica compared to energy transfer from the B800 band of the LH2 complexes (B800-850 and especially B800-820) from other purple bacteria suggests that the electronic structures of ensembles of bacteriochlorophyll molecules in these complexes are substantially different. (laser applications and other topics in quantum electronics)

Fission fragment yields and total kinetic energy release in neutron-induced fission of235,238U,and239Pu

Science.gov (United States)

Tovesson, F.; Duke, D.; Geppert-Kleinrath, V.; Manning, B.; Mayorov, D.; Mosby, S.; Schmitt, K.

2018-03-01

Different aspects of the nuclear fission process have been studied at Los Alamos Neutron Science Center (LANSCE) using various instruments and experimental techniques. Properties of the fragments emitted in fission have been investigated using Frisch-grid ionization chambers, a Time Projection Chamber (TPC), and the SPIDER instrument which employs the 2v-2E method. These instruments and experimental techniques have been used to determine fission product mass yields, the energy dependent total kinetic energy (TKE) release, and anisotropy in neutron-induced fission of U-235, U-238 and Pu-239.

Total Variation-Based Reduction of Streak Artifacts, Ring Artifacts and Noise in 3D Reconstruction from Optical Projection Tomography

Czech Academy of Sciences Publication Activity Database

Michálek, Jan

2015-01-01

Roč. 21, č. 6 (2015), s. 1602-1615 ISSN 1431-9276 R&D Projects: GA MŠk(CZ) LH13028; GA ČR(CZ) GA13-12412S Institutional support: RVO:67985823 Keywords : optical projection tomography * microscopy * artifacts * total variation * data mismatch Subject RIV: EA - Cell Biology Impact factor: 1.730, year: 2015

L-H Power Threshold, Pedestal Stability and Confinement in JET with a Metallic Wall

Energy Technology Data Exchange (ETDEWEB)

Beurskens, M.; Alper, B.; Challis, C.; Flanagan, J.; Giroud, C.; Kempenaars, M.; Lomas, P.; Maslov, M.; Matthews, G.; Mayoral, M. L.; Snyder, P. B.; Saarelma, S., E-mail: marc.beurskens@ccfe.ac.uk [EURATOM /CCFE Fusion Association, Culham Science Centre, Abingdon (United Kingdom); Frassinetti, L. [Division of Fusion Plasma Physics, Association EURATOM-VR , Stockholm (Sweden); Maggi, C.; Angioni, C.; Hobirk, J.; Neu, R. [IPP Garching, Garching (Germany); Calabro, G.; Buratti, P.; Giovannozzi, E. [Associazione EURATOM-ENEA sulla Fusione, Frascati (Italy); Bourdelle, C.; Joffrin, E. [Association Euratom-CEA, IRFM, St-Paul-Lez-Durance (France); Brezinsek, S. [Forschungszentrum Juelich, Juelich (Germany); Groth, M. [Association EURATOM/Helsinki University of Technology, Espoo (Finland); Leyland, M. [Department of Physics, University of York, Heslington, York (United Kingdom); De la Luna, E. [Ciemat, Madrid (Spain); Mantica, P. [Istituto di Fisica del Plasma ' P. Caldirola' , Milano (Italy); Nunes, I. [Centro de Fusao Nuclear, Associacao EURATOM-IST, Lisboa (Portugal); Osborne, T. [General Atomics, San Diego (United States); De Vries, P. [FOM DIFFER, Nieuwegein (Netherlands)

2012-09-15

Full text: After the change-over from the Carbon-Fibre Composite (CFC) wall to an ITER-like metallic wall (ILW) the baseline type I ELMy H-mode scenario has been re-established in JET with the new plasma-facing materials Be and W. A key finding for ITER is that the power required to enter H-mode has reduced with respect to that in JET with the CFC wall. In JET with the ILW the power threshold to enter H-mode (P{sub L-H}) is below the international L-H power threshold scaling P{sub Martin-08}. The minimum threshold is P{sub L-H} = 1.8 MW compared to P{sub Martin-08} = 4 MW with a pedestal density of n{sub ped} = 2 x 10{sup 19} m{sup -3} in plasmas with I{sub p} = 2.0 MA, B{sub t} = 2.4 T. However the threshold depends strongly on density; using slow ion cyclotron heating (ICRH) power ramps P{sub L-H} varies from 1.8 to 4.5 MW in a range of lower and upper plasma triangularity ({delta}{sub L} = 0.32 - 0.4, {delta}{sub U} = 0.19 - 0.38). Stationary Type I ELMy H-mode operation has been re-established at both low and high triangularity with I{sub p} {<=} 2.5 MA, q{sub 95} = 2.8 - 3.6 and H{sub 98} {<=} 1. The achieved plasma collisionality is relatively high, in the range of 1 < v{sub eff} < 4 due to the required strong gas dosing. Stability analysis with the linear MHD stability code ELITE show that the pedestal is marginally unstable with respect to the Peeling Ballooning boundary. Due to the stabilising effect of the global pressure on the pedestal stability, a strong coupling between core and edge confinement is expected. Indeed in an H-mode profile database comparison with 119 CFC- (0.1 < v{sub eff} < 1) and 40 ILW-H-modes a strong coupling of the core versus edge confinement is found, independent of wall material. In addition, the pedestal predictions using the EPED predictive pedestal code coincide with the measured pedestal height over a wide range of normalised pressure 1.5 < {beta}{sub N} < 3.5. Due to the strong core-edge coupling, beneficial effects of core

[Diagnostic value of baseline serum luteinizing hormone level for central precocious puberty in girls].

Science.gov (United States)

Ou-Yang, Li-Xue; Yang, Fan

2017-07-01

To evaluate the diagnostic value of baseline serum luteinizing hormone (LH) level for central precocious puberty (CPP) in girls. A total of 279 girls with precocious puberty were subjected to assessment of growth and development, bone age determination, baseline LH test, and follicle-stimulating hormone (FSH) test, gonadotropin-releasing hormone stimulation test, and other related examinations. Of the 279 patients, 175 were diagnosed with CPP and 104 with premature thelarche (PT). The receiver operating characteristic (ROC) curve was used to evaluate the diagnostic value of baseline LH and FSH levels and their peak levels for CPP, and the correlation between the baseline LH level and the peak LH level was analyzed. The CPP group had significantly higher bone age, baseline LH and FSH levels, peak LH and FSH levels, and ratio of peak LH level to peak FSH level than the PT group (Pbaseline LH level and peak LH level had good diagnostic values for CPP. Among the three bone age subgroups in the CPP group (7.0-9.0 years, 9.0-11.0 years, and >11.0 years), baseline LH level showed the best diagnostic value in the >11.0 years subgroup, with the largest area under the ROC curve. At a baseline LH level of 0.45 IU/L, the Youden index reached the peak value, and the sensitivity and specificity were 66.7% and 80% respectively, for the diagnosis of CPP. At a peak LH level of 9.935 IU/L, the Youden index reached the peak value, and the sensitivity and specificity were 74.8% and 100% respectively, for the diagnosis of CPP. The baseline LH level was positively correlated with the peak LH level (r=0.440, PBaseline LH level can be used as an primary screening index for the diagnosis of CPP. It has a certain diagnostic value for CPP at different bone ages, and may be used as a monitoring index during the treatment and follow-uP.

PERBAIKAN KEBIJAKAN PENGENDALIAN PERSEDIAAN JUST IN TIME KOMPONEN PRODUK MAIN FLOOR SIDE LH PADA PT GAYA MOTOR

Directory of Open Access Journals (Sweden)

Bella Suciana Istiqomah

2015-06-01

Full Text Available PT . Gaya Motor is a manufacturing company that is engaged in the assembly and production of automotive components incorporated in the group of PT Astra International.Perusahaan implement inventory control system Just In Time.Kanban’s supplier with safety stock of 0.5 days plus a safety stock of 0.5 extra days beyond the kanban. The study was conducted on the material supply products Main Floor Side LH SA - 001 , SA - 002 , SA - 003 , SA - 004 , SA - 005 , SA - 006 , SA - 007 , SA - 008 and SA - 009. Problems faced by the company are the high amount of inventory caused by inaccurate inventory systems and fault current in raw material procurement procedures. The purpose of this study was to evaluate the company's current inventory control system and propose improvements inventory control system that can minimize inventory costs compared to the cost of inventory at the company's current inventory system.Kanban inventory method supplier company currently has a total cost of inventory of Rp 318.861.462,00. Supplier kanban inventory control methods with safety stock kanban 0.1 days has a total cost of inventory of Rp 158.703.378,00. Inventory control methods Two - Bin Replenishment has a total inventory cost of Rp 98.497.214,00. From the results of these calculations, the minimum inventory cost obtained by using the method of inventory Two - Bin Replenishment, and made proposals related to changes in inventory control system.

Evidence of excited state localization and static disorder in LH2 investigated by 2D-polarization single-molecule imaging at room temperature.

Science.gov (United States)

Tubasum, Sumera; Camacho, Rafael; Meyer, Matthias; Yadav, Dheerendra; Cogdell, Richard J; Pullerits, Tõnu; Scheblykin, Ivan G

2013-12-07

Two-dimensional polarization fluorescence imaging of single light harvesting complexes 2 (LH2) of Rps. acidophila was carried out to investigate the polarization properties of excitation and fluorescence emission simultaneously, at room temperature. In two separate experiments we excited LH2 with a spectrally narrow laser line matched to the absorption bands of the two chromophore rings, B800 and B850, thereby indirectly and directly triggering fluorescence of the B850 exciton state. A correlation analysis of the polarization modulation depths in excitation and emission for a large number of single complexes was performed. Our results show, in comparison to B800, that the B850 ring is a more isotropic absorber due to the excitonic nature of its excited states. At the same time, we observed a strong tendency for LH2 to emit with dipolar character, from which preferential localization of the emissive exciton, stable for minutes, is inferred. We argue that the observed effects can consistently be explained by static energetic disorder and/or deformation of the complex, with possible involvement of exciton self-trapping.

The Effects of Trifluralin on LH, FSH and Testosterone Hormone Levels and Testis Histological Changes in Adult Rats

Directory of Open Access Journals (Sweden)

Mehrdad Shariati

2008-01-01

Full Text Available Background: Trifluralin is a herbicide and used in agriculture widely. It enters plants throughdeveloping roots and stops plant cells from division and elongation (meristemic inhibitor.Extensive application of trifluralin to control annual grasses and broadleaf weeds in agriculture,horticulture and horn garden, leads to environmental pollution and its entrance into the food chaincould have determined effects on human and other species. In this research the effects of trifluralinon reproductive parameters of the male rats including serum luteinizing hormone (LH, folliclestimulatinghormone (FSH, testosterone levels, and changes in testicular tissue and body weightwere investigated.Materials and Methods: For this purpose male rats were randomly divided in 5 groups, to includecontrol, sham (received normal saline as a solvent, and three experimental groups which received500, 1000 and 2000 mg/kg oral trifluralin respectively. After 16 days, body and testis weight weremeasured and blood samples were taken from heart and used for measurement of LH, FSH andtestosterone levels. To evaluate histological changes, testes were removed and weighed and, afterobtaining tissue section, stained by HE.Results: Serum testosterone, FSH, and LH levels showed significant decrease in experimentalgroups (p<0.05. There was significant decrease in the number of germinal and somatic cells intestis in experimental groups. There was also a significant decrease in body and testis weight inexperimental groups.Conclusion: It can be concluded that oral administration of trifluralin could decrease gonadotropinsand testosterone hormone levels and also this herbicide could have hazardous effects on testistissue.

Development of an objective assessment tool for total laparoscopic hysterectomy: A Delphi method among experts and evaluation on a virtual reality simulator

Science.gov (United States)

Knight, Sophie; Aggarwal, Rajesh; Agostini, Aubert; Loundou, Anderson; Berdah, Stéphane

2018-01-01

Introduction Total Laparoscopic hysterectomy (LH) requires an advanced level of operative skills and training. The aim of this study was to develop an objective scale specific for the assessment of technical skills for LH (H-OSATS) and to demonstrate feasibility of use and validity in a virtual reality setting. Material and methods The scale was developed using a hierarchical task analysis and a panel of international experts. A Delphi method obtained consensus among experts on relevant steps that should be included into the H-OSATS scale for assessment of operative performances. Feasibility of use and validity of the scale were evaluated by reviewing video recordings of LH performed on a virtual reality laparoscopic simulator. Three groups of operators of different levels of experience were assessed in a Marseille teaching hospital (10 novices, 8 intermediates and 8 experienced surgeons). Correlations with scores obtained using a recognised generic global rating tool (OSATS) were calculated. Results A total of 76 discrete steps were identified by the hierarchical task analysis. 14 experts completed the two rounds of the Delphi questionnaire. 64 steps reached consensus and were integrated in the scale. During the validation process, median time to rate each video recording was 25 minutes. There was a significant difference between the novice, intermediate and experienced group for total H-OSATS scores (133, 155.9 and 178.25 respectively; p = 0.002). H-OSATS scale demonstrated high inter-rater reliability (intraclass correlation coefficient [ICC] = 0.930; pvirtual reality simulator. The implementation of this scale is expected to facilitate deliberate practice. Next steps should focus on evaluating the validity of the scale in the operating room. PMID:29293635

Development of an objective assessment tool for total laparoscopic hysterectomy: A Delphi method among experts and evaluation on a virtual reality simulator.

Science.gov (United States)

Knight, Sophie; Aggarwal, Rajesh; Agostini, Aubert; Loundou, Anderson; Berdah, Stéphane; Crochet, Patrice

2018-01-01

Total Laparoscopic hysterectomy (LH) requires an advanced level of operative skills and training. The aim of this study was to develop an objective scale specific for the assessment of technical skills for LH (H-OSATS) and to demonstrate feasibility of use and validity in a virtual reality setting. The scale was developed using a hierarchical task analysis and a panel of international experts. A Delphi method obtained consensus among experts on relevant steps that should be included into the H-OSATS scale for assessment of operative performances. Feasibility of use and validity of the scale were evaluated by reviewing video recordings of LH performed on a virtual reality laparoscopic simulator. Three groups of operators of different levels of experience were assessed in a Marseille teaching hospital (10 novices, 8 intermediates and 8 experienced surgeons). Correlations with scores obtained using a recognised generic global rating tool (OSATS) were calculated. A total of 76 discrete steps were identified by the hierarchical task analysis. 14 experts completed the two rounds of the Delphi questionnaire. 64 steps reached consensus and were integrated in the scale. During the validation process, median time to rate each video recording was 25 minutes. There was a significant difference between the novice, intermediate and experienced group for total H-OSATS scores (133, 155.9 and 178.25 respectively; p = 0.002). H-OSATS scale demonstrated high inter-rater reliability (intraclass correlation coefficient [ICC] = 0.930; pvirtual reality simulator. The implementation of this scale is expected to facilitate deliberate practice. Next steps should focus on evaluating the validity of the scale in the operating room.

Consideration of LH2 and LD2 cold neutron sources in heavy water reactor reflector

International Nuclear Information System (INIS)

Potapov, I.A.; Serebrov, A.P.

2001-01-01

The reactor power, the required CNS dimensions and power of the cryogenic equipment define the CNS type with maximized cold neutron production. Cold neutron fluxes from liquid hydrogen (LH 2 ) and liquid deuterium (LD 2 ) cold neutron sources (CNS) are analyzed. Different CNS volumes, presents and absence of reentrant holes inside the CNS, different adjustment of beam tube and containment are considered. (orig.)

Transient absorption study of two-photon excitation mechanism in the LH2 complex from purple bacterium Rhodobacter sphaeroides.

Science.gov (United States)

Stepanenko, Ilya; Kompanetz, Viktor; Makhneva, Zoya; Chekalin, Sergey; Moskalenko, Andrei; Razjivin, Andrei

2012-03-08

The mechanism of two-photon excitation of a peripheral light-harvesting complex LH2 (B800-850) from purple bacterium Rhodobacter sphaeroides was explained on the basis of femtosecond transient absorption data. Fast bleaching of the B850 absorption band was measured under two-photon excitation by 1350 nm femtosecond pulses, showing fast subpicosecond arrival of excitation energy to B850 circular aggregates. Any spectral changes connected with the B800 absorption band of B800-BChl molecules were absent. A similar picture was observed under one-photon excitation of the LH2 complex by 675 nm femtosecond pulses. We believe these effects may be attributed to direct excitation of high-energy excitonic states of a B850 circular aggregate or its vibrational manifold in accordance with the model of Abe [Chem. Phys. 2001, 264, 355-363].

Effects of long term feeding of Quillaja saponins on sex ratio, muscle and serum cholesterol and LH levels in Nile tilapia (Oreochromis niloticus (L)).

Science.gov (United States)

Francis, George; Levavi-Sivan, Berta; Avitan, Ayelet; Becker, Klaus

2002-12-01

Seventeen-day-old Nile tilapia fry were fed a standard diet (C) or diets containing 50-700 mg kg(-1) Quillaja saponin (QS) extract (groups S50, S150, S300, S500 and S700). After the first 8 weeks, 30 randomly selected tilapia from each of the treatments were placed in separate aquaria and fed the standard diet without saponins from then on (these were designated S50/C, S150/C, S300/C, S500/C and S700/C). The fish grew from an initial average weight of approximately 30 mg to a final average weight of 79 g during the 6-month feeding period. The difference between the average weight of C-fed tilapia and the treatment with the highest average weight after 6 months was 53.5%. The sex ratio of tilapia in the saponin-fed groups deviated from the normal 50:50 male:female ratio, with the S700 group showing a significantly higher number of males. Quillaja saponin stimulated LH release from dispersed tilapia pituitary cells in vitro. This effect was abolished in the presence of dilute calf serum. Serum LH values did not show any diet-dependent trend in either male or female tilapia in vivo. In both continuously saponin-fed and only-initially saponin-fed groups, the average serum (but not muscle) cholesterol levels in males showed an increasing trend (R(2) values of 0.62 and 0.69) with increasing dietary saponin level. It was concluded that dietary QS has the potential to change the sex-ratio in favour of males. More investigations are required to determine the mechanism of action and the optimum dietary level of QS for maximum effects.

Comparison of the Levels of LH and FSH, TSH, Prolactin, Progesterone and Estradiol Hormones between Iranian Infertile Women with Polycystic Ovary Syndrome and Healthy Women

Directory of Open Access Journals (Sweden)

Amir Hossein Hashemi

2016-12-01

Full Text Available Polycystic ovary syndrome (PCOS with the prevalence of 5 to 7% among Iranian women is a leading cause of infertility and endocrine disorder. Metabolic disorders such as increased levels of LH and FSH hormones in these patients was common and influences health of women with PCOS in long-term. Treatment of female infertility and other complications in many cases need to regulate hormones and receive exogenous hormone, and then the effect of female hormones on the disease is very important. In this study, levels of Luteinizing hormone (LH and Follicle stimulating hormone (FSH and other female hormones among Iranian women with PCOS and infertility and healthy people were measured in this regard and values were compared. The result of this study showed that LH and progesterone hormone levels were significantly different in this syndrome than healthy women.

Study of EAST LH antennas coupling at ENEA-Frascati

Energy Technology Data Exchange (ETDEWEB)

Panaccione, L.; Mirizzi, F. [Consorzio CREATE, Via Claudio 21, 80125, Napoli (Italy); Ceccuzzi, S.; Cesario, R.; Tuccillo, A. A., E-mail: angelo.tuccillo@enea.it [ENEA for EUROfusion, via E. Fermi 45, 00044 Frascati (RM) (Italy); Ding, B. J.; Li, M.; Liu, F.; Liu, L.; Shan, J. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China)

2015-12-10

The two Lower Hybrid (LH) launchers of the EAST tokamak have been analysed using some tools available at ENEA-Frascati research centre. The antennas, working at 2.45 and 4.6 GHz, have been assessed in terms of reflection coefficient and launched power spectrum for several plasma loads differing in the electron density profile. Fitting an experimental profile we derived a set of parameterised realistic density profiles to compute the coupling performances of different spectra, launched by considering different phasing between antenna modules. The sensitivity to the tilt of the magnetic field with respect to the equatorial plane as well as to an additional progressive phasing at the mouth due to the toroidal curvature has been studied too. The most suitable operational conditions for the minimization of reflected power and side lobes in the n{sub ||} spectra are identified.

5l/h pump for dosing corrosion radioactive liquids

International Nuclear Information System (INIS)

Przybylovich, S.; Shraer, V.; Chermak, R.

1977-01-01

The technical requirements, design and main technical characteristics of the pump for dosing corrosion and radioactive liquids with capacity up to 5 l/h are described. The design is based on the popular sixvertical split casing pump. The pump has four separate pump membrane type blocks with nonstraight hydraulic membrane control. The membranes are made of the cold worked CrNi(18/10)type stainless steel with thickness up to 0.1 mm and have the lifetime up to 3000 hours. The remote pump heads are used for pumping radioactive fluids when the pumping goes behind the safe wall, separating the pump from a hot lab. The tests showed that the pump secures the satisfactory accuracy of dozing and uniformity of pumping and that it is really possible to achieve the required life time of 10000 hours by this pump

TOPLHA: an accurate and efficient numerical tool for analysis and design of LH antennas

International Nuclear Information System (INIS)

Milanesio, D.; Lancellotti, V.; Meneghini, O.; Maggiora, R.; Vecchi, G.; Bilato, R.

2007-01-01

Auxiliary ICRF heating systems in tokamaks often involve large complex antennas, made up of several conducting straps hosted in distinct cavities that open towards the plasma. The same holds especially true in the LH regime, wherein the antennas are comprised of arrays of many phased waveguides. Upon observing that the various cavities or waveguides couple to each other only through the EM fields existing over the plasma-facing apertures, we self-consistently formulated the EM problem by a convenient set of multiple coupled integral equations. Subsequent application of the Method of Moments yields a highly sparse algebraic system; therefore formal inversion of the system matrix happens to be not so memory demanding, despite the number of unknowns may be quite large (typically 10 5 or so). The overall strategy has been implemented in an enhanced version of TOPICA (Torino Polytechnic Ion Cyclotron Antenna) and in a newly developed code named TOPLHA (Torino Polytechnic Lower Hybrid Antenna). Both are simulation and prediction tools for plasma facing antennas that incorporate commercial-grade 3D graphic interfaces along with an accurate description of the plasma. In this work we present the new proposed formulation along with examples of application to real life large LH antenna systems

Cetirizine release from cyclodextrin formulated compressed chewing gum

DEFF Research Database (Denmark)

Stojanov, Mladen; Larsen, Kim Lambertsen

2012-01-01

release patterns, but with variations in the total amount released. Chewing gum formulated with cetirizine alone, demonstrated a release of 75% after 8 min of chewing. The presence of CDs resulted in increased cetirizine release. The analysis of variance (ANOVA) demonstrated that parameters with the most...... the statistical analysis (ANOVA) demonstrated significance in the release (P

Role of the higher harmonics in the launched LH spectrum in the ponderomotive effects at the plasma edge

Energy Technology Data Exchange (ETDEWEB)

Preinhaelter, J [Akademie Ved Ceske Republiky, Prague (Czech Republic). Ustav Fyziky Plazmatu; Vahala, L [Old Dominion Univ., Norfolk, VA (United States). Dept. of Electrical and Computer Engineering; Vahala, G [College of William and Mary, Williamsburg, VA (United States). Dept. of Physics

1995-12-01

The ponderomotive effects of higher harmonic waves in the lower hybrid waveguide grill power spectrum were investigated. Although possessing a few percent of the coupled power, these short-wavelength modes play an important part in the inhomogeneous scrape-off layer in tokamak plasma. Using a barometric representation of the ponderomotive potential for the electron density, the full wave coupled theory was solved self-consistently for 4 modes using a shooting-and-matching method to satisfy the surface impedance boundary conditions determined from infinite grill theory. For a symmetric LH spectrum and below a threshold power, the total reflection coefficient is independent of the coupled power. Isolated plasma density depressions (cavitons) are formed in regions of constructive superposition of short and long wavelength modes. Intense mode conversion also occurs in these regions. For power levels above the threshold, the reflection coefficient increases with power and eventually saturates. Numerical results are presented for the ASDEX tokamak and its 24 waveguide grill. 19 figs., 20 refs.

Comparing the Immediate Effects of a Total Motion Release Warm-up and a Dynamic Warm-up Protocol on the Dominant Shoulder in Baseball Athletes.

Science.gov (United States)

Gamma, Stephen C; Baker, Russell; May, James; Seegmiller, Jeff G; Nasypany, Alan; Iorio, Steven M

2018-04-10

Gamma, SC, Baker, R, May, J, Seegmiller, JG, Nasypany, A, and Iorio, SM. Comparing the immediate effects of a total motion release warm-up and a dynamic warm-up protocol on the dominant shoulder in baseball athletes. J Strength Cond Res XX(X): 000-000, 2017-A decrease in total range of motion (ROM) of the dominant shoulder may predispose baseball athletes to increased shoulder injury risk; the most effective technique for improving ROM is unknown. The purpose of this study was to compare the immediate effects of Total Motion Release (TMR) to a generic dynamic warm-up program in baseball athletes. Baseball athletes (n = 20) were randomly assigned to an intervention group: TMR group (TMRG; n = 10) or traditional warm-up group (TWG; n = 10). Shoulder ROM measurements were recorded for internal rotation (IR) and external rotation (ER), the intervention was applied, and postmeasurements were recorded. Each group then received the other intervention and postmeasurements were again recorded. The time main effect (p ≤ 0.001) and the time × group interaction effect were significant (p ≤ 0.001) for IR and ER. Post hoc analysis revealed that TMR produced significant increases in mean IR (p ≤ 0.005, d = 1.52) and ER (p ≤ 0.018, d = 1.22) of the dominant shoulder initially. When groups crossed-over, the TMRG experienced a decrease in mean IR and ER after the dynamic warm-up, whereas the TWG experienced a significant increase in mean IR (p ≤ 0.001, d = 3.08) and ER (p ≤ 0.001, d = 2.56) after TMR intervention. Total Motion Release increased IR and ER of the dominant shoulder more than a dynamic warm-up. Dynamic warm-up after TMR also resulted in decreased IR and ER; however, TMR after dynamic warm-up significantly improved IR and ER. Based on these results, TMR is more effective than a generic dynamic warm-up for improving dominant shoulder ROM in baseball players.

The effect of Ramadan fasting on LH, FSH, oestrogen, progesterone and leptin in pregnant women.

Science.gov (United States)

Khoshdel, A; Kheiri, S; Hashemi-Dehkordi, E; Nasiri, J; Shabanian-Borujeni, S; Saedi, E

2014-10-01

Many pregnant Muslim women fast during Ramadan. Leptin has an important role in the reproductive system and hormones. In this study, FSH, LH, oestrogen, progesterone and leptin were measured in the first, second and fourth week of Ramadan and the second week post-Ramadan, in 30 fasting pregnant women. Data were analysed using repeated measures ANOVA by SPSS. The weight and BMI did not change during the study. A significant change in FSH, oestrogen, progesterone and leptin was observed (p Ramadan. Progesterone increased at the end of Ramadan and the second week after. Oestrogen increased significantly during Ramadan and decreased after Ramadan. A decreasing trend was seen in LH during the Ramadan and 2 weeks after (p Ramadan. We found poor weight gain and hypoleptinaemia in pregnant fasted women during the study. Food restriction in pregnant fasted women during Ramadan may induce poor weight gain during pregnancy. These data confirm that Ramadan fasting by pregnant women may have potential risks during pregnancy. We recommend further study to evaluate long-term effects of Ramadan fasting during pregnancy in different countries with different food habits and traditions, to obtain reliable and documented data.

131I release from a HTGR during the LOFC accident

International Nuclear Information System (INIS)

Foley, J.E.

1975-03-01

The time-dependent release of 131 I from both the core and the containment building of a high temperature gas-cooled (HTGR) reactor during the loss of forced coolant (LOFC) accident is studied. A simplified core release model is combined with a containment building release model so that the total amount of the isotope released to the environment can be calculated. The time-dependent release of 131 I from the core during the LOFC accident is primarily a function of the time-dependent core temperatures and the failed fuel release constants. The most important factor in calculating the amount of the isotope released to the environment is the total amount released into the containment building. (U.S.)

Statistical theory of L-H transition and its implication to threshold database

International Nuclear Information System (INIS)

Itoh, S.-I.; Itoh, K.; Toda, S.

2003-01-01

A statistical model for the bifurcation of the radial electric field E r is analyzed in view of describing L-H transitions of toroidal plasmas. Noise in micro fluctuations is shown to lead to random changes of E r , if a deterministic approach allows for more than one solution. The probability density function for and the ensemble average of E r are obtained. The L-to-H and the H-to-L transition probabilities are calculated, and the effective phase limit is derived. Due to the suppression of turbulence by shear in E r , the limit deviates from Maxwell's rule. (author)

Energy transfer in LH2 of Rhodospirillum Molischianum, studied by subpicosecond spectroscopy and configuration interaction excition calculations.

NARCIS (Netherlands)

Ihalainen, J.A.; Linnanto, J.; Myllyperkiö, P.; van Stokkum, I.H.M.; Ücker, B.; Scheer, H.; Korppi-Tommola, J.E.I.

2001-01-01

Two color transient absorption measurements were performed on a LH2 complex from Rhodospirillum molischianum by using several excitation wavelengths (790, 800, 810, and 830 nm) and probing in the spectral region from 790 to 870 nm at room temperature. The observed energy transfer time of ∼1.0 ps

Energy transfer in LH2 of Rhodospirillum Molischianum, studied by subpicosecond spectroscopy and configuration interaction exciton calculations.

NARCIS (Netherlands)

Ihalainen, J.A.; Linnanto, J.; Myllyperkio, P.; van Stokkum, I.H.M.; Ucker, B.; Scheer, H.; Korppi-Tommola, J.E.I.

2001-01-01

Two color transient absorption measurements were performed on a LH2 complex from Rhodospirillum molischianum by using several excitation wavelengths (790, 800, 810, and 830 nm) and probing in the spectral region from 790 to 870 nm at room temperature. The observed energy transfer time of ∼1.0 ps

Developmental programming: impact of prenatal testosterone excess on pre- and postnatal gonadotropin regulation in sheep.

Science.gov (United States)

Manikkam, Mohan; Thompson, Robert C; Herkimer, Carol; Welch, Kathleen B; Flak, Jonathan; Karsch, Fred J; Padmanabhan, Vasantha

2008-04-01

The goal of this study was to explore mechanisms that mediate hypersecretion of LH and progressive loss of cyclicity in female sheep exposed during fetal life to excess testosterone. Our working hypothesis was that prenatal testosterone excess, by its androgenic action, amplifies GnRH-induced LH (but not FSH) secretion and, thus, hypersecretion of LH in adulthood, and that this results from altered developmental gene expression of GnRH and estradiol (E2) receptors, gonadotropin subunits, and paracrine factors that differentially regulate LH and FSH synthesis. We observed that, relative to controls, females exposed during fetal life to excess testosterone, as well as the nor-aromatizable androgen dihydrotestosterone, exhibited enhanced LH but not FSH responses to intermittent delivery of GnRH boluses under conditions in which endogenous LH (GnRH) pulses were suppressed. Luteinizing hormone hypersecretion was more evident in adults than in prepubertal females, and it was associated with development of acyclicity. Measurement of pituitary mRNA concentrations revealed that prenatal testosterone excess induced developmental changes in gene expression of pituitary GnRH and E2 receptors and paracrine modulators of LH and FSH synthesis in a manner consistent with subsequent amplification of LH release. Together, this series of studies suggests that prenatal testosterone excess, by its androgenic action, amplifies GnRH-induced LH response, leading to LH hypersecretion and acyclicity in adulthood, and that this programming involves developmental changes in expression of pituitary genes involved in LH and FSH release.

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

Science.gov (United States)

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

1990-06-01

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