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1.
Anticancer Res ; 41(5): 2661-2667, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33952497

RESUMO

BACKGROUND/AIM: The significance of epidermal growth factor receptor (EGFR) mutation in untreated patients with non-small cell lung cancer (NSCLC) remains uncertain. We aimed to determine the significance of EGFR mutation in patients who received best supportive care (BSC) alone, and compare the outcomes of only EGFR- tyrosine kinase inhibitors (TKI)-treated vs. BSC patients. PATIENTS AND METHODS: Between April 1991-August 2018, 1,197 patients diagnosed with unresectable NSCLC at our institutions were enrolled in the study. RESULTS: Among 226 patients who underwent EGFR mutation analysis and received BSC alone, 35 and 191 did and did not harbor the mutation, and the median survival times (MST) did not differ significantly between these groups. A comparison of only EGFR-TKI-treated and BSC patients with EGFR mutation revealed that the former had a three times longer MST than the latter. CONCLUSION: Our results may help explain the benefit of EGFR-TKI for patients who would be directed towards BSC.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Inibidores de Proteínas Quinases/administração & dosagem , Idoso , Idoso de 80 Anos ou mais , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Intervalo Livre de Doença , Receptores ErbB/genética , Feminino , Humanos , Masculino , Mutação/genética , Inibidores de Proteínas Quinases/efeitos adversos , Resultado do Tratamento
2.
Domest Anim Endocrinol ; 74: 106522, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32841888

RESUMO

Heat stress disrupts reproductive function in cattle. In summer, high ambient temperature and humidity elevate core body temperature, which is considered to be detrimental to reproductive abilities in cattle. Neurokinin B (NKB) is a factor that generates pulsatile GnRH and subsequent LH secretion in mammals. Recent studies have reported that NKB-neurokinin 3 receptor (NK3R) signaling is associated with heat-defense responses in rodents. The present study aimed to clarify the role of NKB-NK3R signaling in thermoregulation in cattle. We examined the effects of an NK3R-selective agonist, senktide, on vaginal temperature as an indicator of core body temperature in winter and summer. In both seasons, continuous infusion of senktide for 4 h immediately decreased vaginal temperature, and the mean temperature change in the senktide-treated group was significantly lower than that of both vehicle- and GnRH-treated groups. Administration of GnRH induced LH elevation, but there was no significant difference in vaginal temperature change between GnRH- and vehicle-treated groups. Moreover, we investigated the effects of senktide on ovarian temperature. Senktide treatment seemed to suppress the increase in ovarian temperature from 2 h after the beginning of administration, although the difference between groups was not statistically significant. Taken together, these results suggest that senktide infusion caused a decline in the vaginal temperature of cattle, in both winter and summer seasons, and this effect was not due to the gonadotropin-releasing action of senktide. These findings provide new therapeutic options for senktide to support both heat-defense responses and GnRH/LH pulse generation.


Assuntos
Temperatura Corporal/efeitos dos fármacos , Bovinos/fisiologia , Resposta ao Choque Térmico/efeitos dos fármacos , Fragmentos de Peptídeos/farmacologia , Receptores da Neurocinina-3/agonistas , Substância P/análogos & derivados , Animais , Regulação da Temperatura Corporal/efeitos dos fármacos , Regulação da Temperatura Corporal/fisiologia , Feminino , Hormônio Liberador de Gonadotropina/fisiologia , Hormônio Luteinizante/fisiologia , Neurocinina B/fisiologia , Ovário/fisiologia , Fragmentos de Peptídeos/uso terapêutico , Receptores da Neurocinina-3/fisiologia , Transdução de Sinais/fisiologia , Substância P/farmacologia , Substância P/uso terapêutico , Vagina/fisiologia
3.
Sci Rep ; 10(1): 22109, 2020 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-33335175

RESUMO

Ti2O3 exhibits unique metal-insulator transition (MIT) at ~ 450 K over a wide temperature range of ~ 150 K. The close relationship between MIT and crystal deformation has been proposed. However, as physical properties are governed by the thermodynamic equilibrium in bulk systems, conducting experimental studies under different lattice deformations remains challenging. Epitaxial thin films can offer high flexibility to accommodate adaptive crystal lattices and provide efficient platforms for investigating the MIT. In this study, we report the synthesis of corundum-type Ti2O3 films on various growth temperatures. We found that the metallic ground states appeared in the films grown at low temperatures. The electronic ground states were further investigated by the electronic-structure calculations. Results suggest that the electrical properties of Ti2O3 films were governed by the c/a ratio of the crystal structure, and the absence of the MIT was attributed to the lattice deformation characterized by an elongated c lattice constant.

4.
Mucosal Immunol ; 12(5): 1201-1211, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31417161

RESUMO

Uncontrolled interferon γ (IFNγ)-mediated T-cell responses to commensal microbiota are a driver of inflammatory bowel disease (IBD). Interleukin-10 (IL-10) is crucial for controlling these T-cell responses, but the precise mechanism of inhibition remains unclear. A better understanding of how IL-10 exerts its suppressive function may allow identification of individuals with suboptimal IL-10 function among the heterogeneous population of IBD patients. Using cells from patients with an IL10RA deficiency or STAT3 mutations, we demonstrate that IL-10 signaling in monocyte-derived dendritic cells (moDCs), but not T cells, is essential for controlling IFNγ-secreting CD4+ T cells. Deficiency in IL-10 signaling dramatically increased IL-1ß release by moDCs. IL-1ß boosted IFNγ secretion by CD4+ T cells either directly or indirectly by stimulating moDCs to secrete IL-12. As predicted a signature of IL-10 dysfunction was observed in a subgroup of pediatric IBD patients having higher IL-1ß expression in activated immune cells and macroscopically affected intestinal tissue. In agreement, reduced IL10RA expression was detected in peripheral blood mononuclear cells and a subgroup of pediatric IBD patients exhibited diminished IL-10 responsiveness. Our data unveil an important mechanism by which IL-10 controls IFNγ-secreting CD4+ T cells in humans and identifies IL-1ß as a potential classifier for a subgroup of IBD patients.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Interferon gama/metabolismo , Interleucina-10/metabolismo , Interleucina-1beta/metabolismo , Transdução de Sinais , Adolescente , Comunicação Celular , Criança , Suscetibilidade a Doenças , Humanos , Doenças Inflamatórias Intestinais/etiologia , Doenças Inflamatórias Intestinais/metabolismo , Doenças Inflamatórias Intestinais/patologia , Doenças Inflamatórias Intestinais/terapia
5.
Domest Anim Endocrinol ; 68: 83-91, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30908995

RESUMO

Pulsatile gonadotropin-releasing hormone (GnRH) secretion is indispensable for reproduction in mammals. Kisspeptin neurons in the hypothalamic arcuate nucleus (ARC), referred to as KNDy neurons because of the coexpression of neurokinin B and dynorphin A, are considered as components of the GnRH pulse generator that produces rhythmic GnRH secretion. The present study aimed to investigate if peripheral administration of PF-4455242, a κ-opioid receptor (KOR, a dynorphin A receptor) antagonist, facilitates pulsatile luteinizing hormone (LH) secretion and GnRH pulse generator activity in estrogen-treated ovariectomized Shiba goats to determine the possibility of using KOR antagonists to artificially control ovarian activities. PF-4455242 was intravenously infused for 4 h (1 or 10 µmol/kg body weight/4 h) or as a single subcutaneous injection (1 or 10 µmol/kg body weight). In a separate experiment, the same KOR antagonist (10 µmol/kg body weight/4 h) was intravenously infused during the recording of multiple unit activity (MUA) in the ARC that reflects the activity of the GnRH pulse generator to test the effects of KOR antagonist administration on GnRH pulse generator activity. Intravenous infusion and single subcutaneous injection of the KOR antagonist significantly increased the frequency of LH pulses compared with controls. Intravenous infusion of KOR antagonist also significantly increased the frequency of episodic bursts in the MUA. The present study demonstrates that peripherally administered KOR antagonist stimulates pulsatile LH secretion by acting on the GnRH pulse generator, and peripheral administration of PF-4455242 can be used to facilitate pulsatile LH secretion, which in turn facilitates ovarian activities in farm animals.


Assuntos
Compostos de Bifenilo/farmacologia , Estrogênios/administração & dosagem , Cabras/fisiologia , Hormônio Liberador de Gonadotropina/metabolismo , Receptores Opioides kappa/antagonistas & inibidores , Sulfonamidas/farmacologia , Animais , Compostos de Bifenilo/administração & dosagem , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Injeções Intravenosas , Injeções Subcutâneas , Ovariectomia/veterinária , Sulfonamidas/administração & dosagem
6.
Osteoporos Int ; 30(3): 697, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30806728

RESUMO

The article Lower grip strength and dynamic body balance in women with distal radial fractures, written by. K. Fujita, H. Kaburagi, A. Nimura, T. Miyamoto, Y. Wakabayashi, Y. Seki, H. Aoyama, H. Shimura, R. Kato, A. Okawa was originally published electronically on the publisher's internet portal.

7.
Osteoporos Int ; 30(5): 949-956, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30607458

RESUMO

In this case-control study, we concluded that women with distal radial fractures who were surgically treated showed lower grip strength and dynamic body balancing than those of controls. These results suggest that measurements of grip strength and dynamic body balance may be useful screening tools to assess future fracture risk. INTRODUCTION: Patients with distal radial fractures (DRFs) are at risk of future fragility fractures. However, their physical characteristics and tendencies for falls remain unclear. We aimed to compare the physical characteristics of women with and without distal radial fractures. METHODS: We included 128 women with a DRF as their first fragility fracture (fracture group) who underwent surgical treatment. Concurrently, 128 age- and sex-matched participants without a history of fragility fractures were selected as controls (control group). The participants underwent assessments of grip strength and the body balancing ability test. Measurements were taken twice in the fracture group, at 2 weeks and 6 months postoperatively, and once in the control group. The body balancing ability test included the Functional Reach Test, Timed Up and Go test (TUG), 2-Step test (2ST), and Timed Uni-pedal Stance test. The participants also completed questionnaires about their health. RESULTS: There were no significant differences (p > 0.05) in patient characteristics between the groups. The fracture group showed lower grip strength across all age groups. In the DRF group, prolonged TUG time was observed at 2 weeks postoperatively in all age groups and at 6 months in participants aged 55-74 years; the 2ST score was significantly lower in participants aged between 65 and 74 years. CONCLUSIONS: Women with DRF demonstrated lower grip strength and dynamic body balancing ability. Lower grip strength and dynamic body balancing ability were identified as significant risk factors in women with DRF, suggesting that these may be useful screening tools to assess fracture risk.


Assuntos
Força da Mão/fisiologia , Fraturas por Osteoporose/fisiopatologia , Equilíbrio Postural/fisiologia , Fraturas do Rádio/fisiopatologia , Acidentes por Quedas , Adulto , Idoso , Densidade Óssea/fisiologia , Estudos de Casos e Controles , Feminino , Humanos , Pessoa de Meia-Idade , Osteoporose Pós-Menopausa/complicações , Osteoporose Pós-Menopausa/fisiopatologia , Fraturas por Osteoporose/etiologia , Período Pós-Operatório , Curva ROC , Fraturas do Rádio/etiologia , Fraturas do Rádio/cirurgia , Medição de Risco/métodos , Fatores de Risco
8.
New Microbes New Infect ; 18: 18-21, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28491325

RESUMO

Propionimicrobium lymphophilum is an anaerobic Gram-positive bacillus that exists in human skin and urinary tract. The pathogenicity is, however, not well known. Only two cases of urinary tract infection have been described recently. In the case presented here, the bacterium was isolated, concomitant with Actinotignum schaalii, from blood culture of a patient with fever and difficulty of urination. The bacteria were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and 16S rRNA sequencing. The case was successfully treated with ampicillin/sulbactam.

9.
J Neuroendocrinol ; 27(1): 57-65, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25367275

RESUMO

A luteinising hormone (LH) surge is fundamental to the induction of ovulation in mammalian females. The administration of a preovulatory level of oestrogen evokes an LH surge in ovariectomised females, whereas the response to oestrogen in castrated males differs among species; namely, the LH surge-generating system is sexually differentiated in some species (e.g. rodents and sheep) but not in others (e.g. primates). In the present study, we aimed to determine whether there is a functional LH surge-generating system in male goats, and whether hypothalamic kisspeptin neurones in male goats are involved in the regulation of surge-like LH secretion. By i.v. infusion of oestradiol (E2; 6 µg/h) for 16 h, a surge-like LH increase occurred in both castrated male and ovariectomised female goats, although the mean peak LH concentration was lower and the mean peak of the LH surge was later in males compared to females. Dual staining with KISS1 in situ hybridisation and c-Fos immunohistochemistry revealed that E2 treatment significantly increased c-Fos expression in the medial preoptic area (mPOA) KISS1 cells in castrated males, as well as ovariectomised females. By contrast, dual-labelled cells were scarcely detected in the arcuate nucleus (ARC) after E2 treatment in both sexes. These data suggest that kisspeptin neurones in the mPOA, but not those in the ARC, are involved in the induction of surge-like LH secretion in both male and female goats. In summary, our data show that the mechanism that initiates the LH surge in response to oestrogen, the mPOA kisspeptin neurones, is functional in male goats. Thus, sexual differentiation of the LH surge-generating system would not be applicable to goats.


Assuntos
Kisspeptinas/metabolismo , Hormônio Luteinizante/biossíntese , Neurônios/metabolismo , Área Pré-Óptica/metabolismo , Animais , Feminino , Cabras , Hibridização In Situ , Kisspeptinas/genética , Hormônio Luteinizante/sangue , Masculino , Área Pré-Óptica/citologia
10.
Science ; 345(6203): 1491-3, 2014 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-25237098

RESUMO

Experimental investigations of transactinoide elements provide benchmark results for chemical theory and probe the predictive power of trends in the periodic table. So far, in gas-phase chemical reactions, simple inorganic compounds with the transactinoide in its highest oxidation state have been synthesized. Single-atom production rates, short half-lives, and harsh experimental conditions limited the number of experimentally accessible compounds. We applied a gas-phase carbonylation technique previously tested on short-lived molybdenum (Mo) and tungsten (W) isotopes to the preparation of a carbonyl complex of seaborgium, the 106th element. The volatile seaborgium complex showed the same volatility and reactivity with a silicon dioxide surface as those of the hexacarbonyl complexes of the lighter homologs Mo and W. Comparison of the product's adsorption enthalpy with theoretical predictions and data for the lighter congeners supported a Sg(CO)6 formulation.

11.
Phys Rev Lett ; 113(9): 096403, 2014 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-25215998

RESUMO

Ultrafast photoinduced transitions of a one-dimensional Mott insulator into two distinct electronic phases, metal and charge-density-wave (CDW) state, were achieved in a bromine-bridged Pd-chain compound [Pd(en)2Br](C5-Y)2H2O (en=ethylenediamine and C5-Y=dialkylsulfosuccinate), by selecting the photon energy of a femtosecond excitation pulse. For the resonant excitation of the Mott-gap transition, excitonic states are generated and converted to one-dimensional CDW domains. For the higher-energy excitation, free electron and hole carriers are produced, giving rise to a transition of the Mott insulator to a metal. Such selectivity in photoconversions by the choice of initial photoexcited states opens a new possibility for the developments of advanced optical switching and memory functions.

12.
Nat Mater ; 13(6): 611-8, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24705382

RESUMO

Resonant X-ray diffraction (RXD) uses X-rays in the vicinity of a specific atomic absorption edge and is a powerful technique for studying symmetry breaking by motifs of various multipole moments, such as electric monopoles (charge), magnetic dipoles (spin) and electric quadrupoles (orbital). Using circularly polarized X-rays, this technique has been developed to verify symmetry breaking effects arising from chirality, the asymmetry of an object upon its mirroring. Chirality plays a crucial role in the emergence of functionalities such as optical rotatory power and multiferroicity. Here we apply spatially resolved RXD to reveal the helix chirality of Dy 4f electric quadrupole orientations and its domain structure in DyFe3(BO3)4, which shows a reversible phase transition into an enantiomorphic space-group pair. The present study provides evidence for a helix chiral motif of quadrupole moments developed in crystallographic helix chirality.

13.
Reprod Domest Anim ; 49(2): 338-42, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24484509

RESUMO

This study evaluated the effects of follicular phase administration of TAK-683, an investigational metastin/kisspeptin analog, on follicular growth, ovulation, luteal function and reproductive hormones in goats. After confirmation of ovulation by transrectal ultrasonography (Day 0), PGF2α (2 mg/head of dinoprost) was administered intramuscularly on Day 10 to induce luteal regression. At 12 h after PGF2α administration, intravenous administration of vehicle or 35 nmol (50 µg)/head of TAK-683 was performed in control (n = 4) and treatment (n = 4) groups, respectively. Blood samples were collected at 6-h intervals for 96 h and then daily until the detection of subsequent ovulation (second ovulation). After the second ovulation, ultrasound examinations and blood sampling were performed every other day or daily until the subsequent ovulation (third ovulation). Mean concentrations of LH and FSH in the treatment group were significantly higher 6 h after TAK-683 treatment than those in the control group (12.0 ± 10.7 vs 1.0 ± 0.7 ng/ml for LH, 47.5 ± 28.2 vs 15.1 ± 3.4 ng/ml for FSH, p < 0.05), whereas mean concentrations of oestradiol in the treatment group decreased immediately after treatment (p < 0.05) as compared with the control group. Ovulation tended to be delayed (n = 2) or occurred early (n = 1) in the treatment group as compared with the control group. For the second ovulation, ovulatory follicles in the treatment group were significantly smaller in maximal diameter than in the control group (3.8 ± 0.5 vs 5.4 ± 0.2 mm, p < 0.05, n = 3). Administration of TAK-683 in the follicular phase stimulates gonadotropin secretion and may have resulted in ovulation of premature follicles in goats.


Assuntos
Cabras/fisiologia , Kisspeptinas/farmacologia , Folículo Ovariano/fisiologia , Animais , Corpo Lúteo/efeitos dos fármacos , Corpo Lúteo/fisiologia , Dinoprosta/administração & dosagem , Dinoprosta/farmacologia , Esquema de Medicação , Feminino , Kisspeptinas/administração & dosagem , Ovulação/efeitos dos fármacos , Ovulação/fisiologia
14.
Nat Commun ; 4: 1835, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23673620

RESUMO

The radioactive element astatine exists only in trace amounts in nature. Its properties can therefore only be explored by study of the minute quantities of artificially produced isotopes or by performing theoretical calculations. One of the most important properties influencing the chemical behaviour is the energy required to remove one electron from the valence shell, referred to as the ionization potential. Here we use laser spectroscopy to probe the optical spectrum of astatine near the ionization threshold. The observed series of Rydberg states enabled the first determination of the ionization potential of the astatine atom, 9.31751(8) eV. New ab initio calculations are performed to support the experimental result. The measured value serves as a benchmark for quantum chemistry calculations of the properties of astatine as well as for the theoretical prediction of the ionization potential of superheavy element 117, the heaviest homologue of astatine.

15.
Phys Rev Lett ; 106(20): 202501, 2011 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-21668223

RESUMO

The low-lying states in ¹°6Zr and ¹°8Zr have been investigated by means of ß-γ and isomer spectroscopy at the radioactive isotope beam factory (RIBF), respectively. A new isomer with a half-life of 620 ± 150 ns has been identified in ¹°8Zr. For the sequence of even-even Zr isotopes, the excitation energies of the first 2⁺ states reach a minimum at N = 64 and gradually increase as the neutron number increases up to N = 68, suggesting a deformed subshell closure at N = 64. The deformed ground state of ¹°8Zr indicates that a spherical subshell gap predicted at N = 70 is not large enough to change the ground state of ¹°8Zr to the spherical shape. The possibility of a tetrahedral shape isomer in ¹°8Zr is also discussed.

16.
Phys Rev Lett ; 106(5): 052502, 2011 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-21405387

RESUMO

The ß-decay half-lives of 38 neutron-rich isotopes from (36)Kr to (43)Tc have been measured; the half-lives of (100)Kr, (103-105)Sr, (106-108)Y, (108-110)Zr, (111,112)Nb, (112-115)Mo, and (116,117)Tc are reported here. The results when compared with previous standard models indicate an overestimation in the predicted half-lives by a factor of 2 or more in the A≈110 region. A revised model based on the second generation gross theory of ß decay better predicts the measured half-lives and suggests a more rapid flow of the rapid neutron-capture process (r-matter flow) through this region than previously predicted.

17.
J Neuroendocrinol ; 22(7): 825-32, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20646176

RESUMO

In sheep and goats, the primer pheromone produced by the male induces out-of-seasonal ovulation in anoestrous females, the so-called 'male effect.' Because the initial endocrine event following reception of the pheromone is the stimulation of pulsatile luteinising hormone (LH) secretion, the central target of the pheromone is considered to be the putative gonadotrophin-releasing hormone (GnRH) pulse generator. Using electrophysiological techniques to record multiple-unit activity (MUA) in close proximity to kisspeptin neurones in the arcuate nucleus (ARC) of Shiba goats, we found that bursts (volleys) of MUA occur at regular intervals, and repetitive bursts are invariably associated with discrete pulses of LH, suggesting that the ARC kisspeptin neurones may be the intrinsic source of the GnRH pulse generator. A brief exposure of female goats to the pheromone immediately elicited an instantaneous rise in MUA, which is followed by an MUA volley and an accompanying LH pulse, indicating that the pheromone signal is transmitted to a subset of the ARC kisspeptin neurones to activate them. Because it has been suggested that the neurokinin B and dynorphin coexpressed in those neurones play critical roles in generating rhythmic bursts, they may be involved in the intracellular pheromone actions that are responsible for inducing the GnRH pulse.


Assuntos
Relógios Biológicos/efeitos dos fármacos , Hormônio Liberador de Gonadotropina/metabolismo , Feromônios/farmacologia , Potenciais de Ação/efeitos dos fármacos , Potenciais de Ação/fisiologia , Animais , Núcleo Arqueado do Hipotálamo/citologia , Núcleo Arqueado do Hipotálamo/efeitos dos fármacos , Núcleo Arqueado do Hipotálamo/metabolismo , Dinorfinas/metabolismo , Eletrofisiologia , Feminino , Humanos , Masculino , Neurocinina B/metabolismo , Neurônios/citologia , Neurônios/efeitos dos fármacos , Neurônios/fisiologia , Ovulação/efeitos dos fármacos , Periodicidade , Transdução de Sinais/efeitos dos fármacos
18.
Rev Sci Instrum ; 81(2): 02B702, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20192442

RESUMO

We have developed a laser and focused ion beam (FIB) compound system to process an optical component device with an ultrafine precision minute surface structure and a micromedical device. This machine consists of an FIB and three types of lasers with an atomic force microscope. This system can fabricate decamicrometer area by laser and submicrometer area by FIB at one chuck. When processing the press mold die of a microlens array (10x10) in a glasslike carbon with a femtosecond laser, a diameter of 3.2 microm and depth of 0.43 microm are obtained. However, the surface roughness is more than Rz=0.5 microm. After this process, we finished this surface with the use of the FIB. As a result, the surface roughness is less than Rz=0.05 microm.


Assuntos
Lasers , Dispositivos Ópticos , Carbono/química , Microscopia de Força Atômica , Propriedades de Superfície , Fatores de Tempo , Raios Ultravioleta
19.
J Neuroendocrinol ; 21(10): 813-21, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19678868

RESUMO

Pulsatile release of gonadotrophin-releasing hormone (GnRH) is indispensable to maintain normal gonadotrophin secretion. The pulsatile secretion of GnRH is associated with synchronised electrical activity in the mediobasal hypothalamus (i.e. multiple unit activity; MUA), which is considered to reflect the rhythmic oscillations in the activity of the neuronal network that drives pulsatile GnRH secretion. However, the cellular source of this ultradian rhythm in GnRH activity is unknown. Direct input from kisspeptin neurones in the arcuate nucleus (ARC) to GnRH cell bodies in the medial preoptic area or their terminals in the median eminence could be the intrinsic source for driving the GnRH pulse generator. To determine whether kisspeptin signalling could be responsible for producing pulsatile GnRH secretion, we studied goats, measured plasma levels of luteinising hormone (LH) and recorded MUA in the posterior ARC, where the majority of kisspeptin neuronal cell bodies are located. Rhythmic volleys of MUA were found to be accompanied by LH pulses with regular intervals in the ARC, where kisspeptin neuronal cell bodies were found. Exogenous administration of kisspeptin stimulated a sustained increase in LH secretion, without influencing MUA, suggesting that the GnRH pulse generator, as reflected by MUA, originated from outside of the network of GnRH neurones, and could plausibly reflect the pacemaker activity of kisspeptin neurones, whose projections reach the median eminence where GnRH fibres project. These observations suggest that the kisspeptin neurones in the ARC may be the intrinsic source of the GnRH pulse generator.


Assuntos
Núcleo Arqueado do Hipotálamo/fisiologia , Hormônio Liberador de Gonadotropina/metabolismo , Hipotálamo/fisiologia , Neurônios/fisiologia , Periodicidade , Sequência de Aminoácidos , Animais , Eletrodos Implantados , Cabras , Humanos , Imuno-Histoquímica , Hibridização In Situ , Kisspeptinas , Hormônio Luteinizante/sangue , Masculino , Dados de Sequência Molecular , Vias Neurais/fisiologia , Orquiectomia , Homologia de Sequência de Aminoácidos , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismo
20.
J Neuroendocrinol ; 21(4): 346-50, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19207811

RESUMO

In small ruminants, such as goats and sheep, a primer pheromone produced by males induces an out-of-seasonal ovulation in anoestrous females, a phenomenon known as the male effect. The male effect is unique in that an external chemical stimulus can immediately modulate the activity of the hypothalamic gonadotrophin-releasing hormone (GnRH) pulse generator. We have established a monitoring method of the GnRH pulse generator activity in Shiba goat. Using this method as a sensitive bioassay to assess the male effect pheromone activity, we have shown that the male effect pheromone is synthesised in an androgen-dependent manner in the sebaceous glands or their vicinity in specific body regions in goats. Although chemical identity of the pheromone is yet to be determined, analyses of male goat hair extracts by gas chromatography fractionation suggest that the male effect pheromone is a volatile substance with relatively small molecular weight. From morphological and molecular biological studies in goats, it is suggested that the pheromone molecule is detected by a member of the V1R family located on both the olfactory neurones and the vomeronasal sensory neurones, and the pheromone signal is conveyed to the medial nucleus of amygdala via the main olfactory and vomeronasal pathways and, subsequently, to the hypothalamic GnRH pulse generator to enhance its activity.


Assuntos
Hormônio Liberador de Gonadotropina/metabolismo , Periodicidade , Ruminantes/fisiologia , Atrativos Sexuais/metabolismo , Tonsila do Cerebelo/fisiologia , Androgênios/metabolismo , Animais , Bioensaio , Feminino , Hipotálamo/fisiologia , Masculino , Vias Neurais/fisiologia , Neurônios/fisiologia , Bulbo Olfatório/fisiologia , Glândulas Sebáceas/metabolismo , Células Receptoras Sensoriais/fisiologia , Caracteres Sexuais , Órgão Vomeronasal/fisiologia
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