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排序方式: 共有9193条查询结果,搜索用时 15 毫秒
51.
52.
Zelinski-Wooten MB; Slayden OD; Chwalisz K; Hess DL; Brenner RM; Stouffer RL 《Human reproduction (Oxford, England)》1998,13(2):259-267
Large doses of antiprogestin typically disrupt menstrual cyclicity. A
chronic low-dose regimen of the potent new antiprogestin ZK 137 316, which
permits continued menstrual cyclicity but alters gonadal- reproductive
tract activity, was established. Rhesus monkeys received vehicle (n = 6) or
0.01 (n = 8), 0.03 (n = 8) or 0.1 (n = 5) mg ZK 137 316/kg body weight
daily for five menstrual cycles (C-1 to C-5). Oestradiol, progesterone and
gonadotrophin profiles were normal during cycles involving vehicle and 0.01
and 0.03 mg ZK 137 316/kg body weight. In the 0.1 mg/kg group, mid-cycle
oestradiol and gonadotrophin surges, and subsequent progesterone
production, were absent in C-3 and C-5. Ovarian cyclicity was accompanied
by timely menstruation in the vehicle and 0.01 mg/kg groups. By C-3, half
the animals in the 0.03 mg/kg group and all animals in the 0.1 mg/kg group
were amenorrhoeic. A corpus luteum was noted during the mid-luteal phase of
C-5 in the vehicle, 0.01 mg/kg and 0.03 mg/kg groups. Large antral and
cystic follicles were evident in the 0.1 mg/kg group. Thus, a daily
treatment with 0.01 mg/kg ZK 136317 permitted normal menstrual cyclicity in
macaques. While the daily administration of 0.03 mg/kg ZK 136 317 allowed
ovarian cyclicity, menstruation was disrupted in some animals. Increasing
the dose to 0.1 mg/kg antagonized pituitary function and resulted in
anovulation and amenorrhoea. A chronic low-dose regimen of the
antiprogestin ZK 137 316, which permits normal ovarian/menstrual cyclicity,
has potential as a contraceptive in women.
相似文献
53.
Bertrand Goudeau Ayush Dagvadorj Fernando Rodrigues‐Lima Patrick Ndellec Monique Casteras‐Simon Emmanuelle Perret Sylvie Langlois Lev Goldfarb Patrick Vicart 《Human mutation》2001,18(5):388-396
Desmin‐related myopathy is a familial or sporadic disease characterized by skeletal muscle weakness and cardiomyopathy as well as the presence of intracytoplasmic aggregates of desmin‐reactive material in the muscle cells. Previously, two kinds of deletions and eight missense mutations have been identified in the desmin gene and proven to be responsible for the disorder. The present study was conducted to determine structural and functional defects in a pathogenic desmin variant that caused a disabling disorder in an isolated case presenting with distal and proximal limb muscle weakness and cardiomyopathy. We identified a novel heterozygous Q389P desmin mutation located at the C‐terminal part of the rod domain as the causative mutation in this case. Transfection of desmin cDNA containing the patient’s mutation into C2.7, MCF7, and SW13 cells demonstrated that the Q389P mutant is incapable of constructing a functional intermediate filament network and has a dominant negative effect on filament formation. We conclude that Q389P mutation is the molecular event leading to the development of desmin‐related myopathy. Hum Mutat 18:388–396, 2001. © 2001 Wiley‐Liss, Inc. 相似文献
54.
Sensory relay structures in the spinal cord dorsal horn are now thought to be active processing structures that function before supraspinal sensory integration. Dorsal horn neurons directly receive nociceptive (pain) signals from the periphery, express a high degree of functional plasticity and are involved in long-term sensitization and chronic pain. We show here that deep dorsal horn neurons (DHNs) in Wistar rats can switch their intrinsic firing properties from tonic to plateau or endogenous bursting patterns, depending upon the balance of control by metabotropic glutamate (mGlu) and GABA(B) receptors. We further show that this modulation acts on at least one common target, the inwardly rectifying potassium channel (Kir3). Finally, we found that these firing modes correspond to specific functional states of information transfer in which dorsal horn neurons can faithfully transmit, greatly enhance or block the transfer of nociceptive information. 相似文献
55.
J-L Stievenart EA Cabanis P Menard J Knoplioch A Lopez J Tamraz M-T Iba-Zizen B Philippe G Prevost J-C Bertrand 《Surgical and radiologic anatomy : SRA》1993,15(1):47-54
Summary In view of the variety of 3D representation techniques, a clinical study was carried out in order to evaluate their respective usefulness. It appears that a single technique cannot be claimed to be valid for all clinical situations and that a combination of representations brings more relevant information. Among the different techniques a clear delineation must be established between those which allow the accurate definition of landmarks (multiplanar reformation, surface representation), and those which do not (integral shading, reconstructed radiology). The main point is the possibility to recognize anatomical landmarks on these latter modes and to choose oblique cut planes in relation to them. Visualization quality is strongly dependent upon the acquisition protocol which must provide a spatial resolution as isotropic as possible.
Une revue de différents modes de visualisation en haute résolution d'un objet volumique avec des applications
Résumé Face à la variété des techniques de représentation 3D une étude clinique a été conduite pour évaluer leurs utilités respectives. Il apparait qu'une technique unique ne peut pas convenir à toutes les situations cliniques et qu'une combinaison de différents modes de présentation apporte une information plus pertinente. Parmi les différentes techniques une distinction claire doit être établie entre celles qui autorisent la prise de repères précis (reformatage multiplanaire, représentation de surface), et celles qui ne le permettent pas (ombrage intégral, radiologie reconstruite). Le point principal est la possibilité de reconnaître des repères anatomiques sur ces derniers modes et de choisir des plans de coupe en relation avec eux. La qualité de la visualisation dépend étroitement du protocole d'acquisition qui doit fournir une résolution aussi isotrope que possible.相似文献
56.
Onody P Bertrand F Muzeau F Bièche I Lidereau R 《Archives of pathology & laboratory medicine》2001,125(6):746-750
BACKGROUND: HER-2/neu (ERBB2) gene amplification and/or overexpression is a major event in human breast tumorigenesis. HER-2/neu gene alterations have been the most frequently assessed prognostic factors during the last 10 years in breast cancer and have recently emerged as a management decision tool and a therapeutic target. There is still controversy over the best method to determine whether a tumor is HER-2/neu positive. Because of the increasing demand for HER-2/neu gene status determination in clinical practice, we compared HER-2/neu gene alterations at the DNA level (gene amplification) and the protein level (overexpression) in a panel of patients with lymph node-negative breast cancer who had received local radiotherapy alone, with no adjuvant therapy. METHODS: We tested 100 excised lymph node-negative breast tumors, using fluorescence in situ hybridization (FISH) with a biotinylated HER-2/neu DNA probe and immunohistochemical assays (IHC) with 2 different antibodies. RESULTS: The FISH frequency of HER-2/neu gene amplification was 15%, and the IHC frequency of overexpression was 21%. CONCLUSION: Although HER-2/neu amplification by FISH and HER-2/neu overexpression by IHC correlated well in this panel of lymph node-negative breast carcinomas, there were a number of discordant cases, pointing to the important need for determining HER-2/neu alteration for the future management of HER-2/neu-based clinical applications. 相似文献
57.
58.
Gonadotrophin-releasing hormone agonist dose-dependency of pituitary desensitization during controlled ovarian hyperstimulation in IVF 总被引:2,自引:2,他引:2
Janssens RM; Vermeiden JP; Lambalk CB; Schats R; Schoemaker J 《Human reproduction (Oxford, England)》1998,13(9):2386-2391
The aim of this study was to find the minimal effective daily s.c. dose of
the gonadotrophin-releasing hormone (GnRH) agonist, triptorelin acetate,
that suppresses the GnRH-induced release of luteinizing hormone (LH) at
time of human chorionic gonadotrophin (HCG) injection and thereby prevents
spontaneous LH surges during in-vitro fertilization (IVF) stimulation
cycles. Therefore, a double-blind, prospective and randomized titration
study was performed. A total of 48 IVF patients were divided into four
groups of 12 patients. Each group received a different dose of triptorelin
acetate, namely 5, 15, 50 or 100 microg s.c. daily. Standard ovarian
stimulation was carried out using urinary follicle stimulating hormone
(FSH) preparations. A 500 microg GnRH test was performed 90 min before the
HCG injection in order to measure the degree of pituitary desensitization.
Spontaneous LH surges were not detected in any of the groups, although
three patients in the 5 microg group had ovulated at the time of ovum
retrieval. The pituitary LH response to the GnRH test at time of HCG,
expressed as area under the curve (AUC), appeared to be dose-dependent.
Thus, a daily s.c. dose of 100 microg triptorelin acetate appears to be too
high, since adequate desensitization of the pituitary (i.e. no spontaneous
LH surge) can be achieved with doses as low as 15 and 50 microg.
相似文献
59.
B lymphocytes secreting IgG linked to latent transforming growth factor- beta prevent primary cytolytic T lymphocyte responses 总被引:3,自引:0,他引:3
B lymphocytes secreting IgG linked to latent transforming growth factor
(TGF)-beta (IgG-TGF-beta) prevent cytolytic T lymphocyte (CTL) responses to
unrelated antigens in mixed lymphocyte cultures (MLC) so long as resting
resident macrophages and functional Fc receptors are present. This was
shown using IgG-secreting plaque-forming cells (PFC) to sheep erythrocytes
(SRBC) obtained from popliteal lymph nodes of mice injected repeatedly in
foot pads with SRBC. Remarkably, as few as approximately 300 PFC prevented
CTL responses of 5 x 10(5) normal syngeneic spleen cells in MLC.
Supranatants of short-term cultures of PFC also prevented CTL responses,
and suppression was prevented by eliminating or dissociating IgG and
TGF-beta present in supranatants or by antibody against active TGF-beta.
Furthermore, the latency- associated peptide of latent TGF-beta was
detected in approximately 10% of foci of IgG captured from single PFC,
indicating that at least some B lymphocytes secrete IgG-TGF-beta as a
complex. Resting resident macrophages (which do not produce latent
TGF-beta) and functional Fc receptors were required for suppression,
consistent with idea that IgG- TGF-beta is taken up through Fc receptors
for IgG and that active TGF- beta, cleaved from latent TGF-beta of the
complex, is delivered directly to potentially responding CTL. If CTL
responses in man are similarly regulated by B lymphocytes, then an ongoing
B cell response in patients with chronic viral infections or bearing
immunogenic cancers may prevent effective therapeutic vaccination.
相似文献
60.
Airway reactivity in children is often assessed using a histamine inhalation challenge test. The bronchoconstrictor agents are usually delivered by five slow inspiratory capacity (IC) maneuvers, the IC method. We compared the IC method with a tidal breathing (TB) method in 30 children; 11 were normal, six were under investigation for asthma and 13 were known asthmatics. None of the normal children responded to either method, whereas 18 out of the 19 (95%) known or suspected asthmatics responded to the TB method while only 13 out of 19 (68%) showed a significant reduction in FEV1 when the IC method was used. The concentration of histamine necessary to cause a 20% reduction in FEV1 was less for the TB method, suggesting that in children the TB method will produce airway reactivity more quickly than the IC method. 相似文献