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排序方式: 共有912条查询结果,搜索用时 15 毫秒
1.
S Oehninger L Veeck D Franken T F Kruger A A Acosta G D Hodgen 《Fertility and sterility》1991,55(6):1165-1170
OBJECTIVE: The purpose of this study was to investigate the sperm-binding potential of human oocytes at different stages of nuclear maturation under hemizona assay (HZA) conditions. DESIGN: This was a prospective study designed in a blinded fashion. SETTING: Academic research environment approved by the Institutional Review Board. PATIENTS: Surplus oocytes, donated by patients undergoing in vitro fertilization therapy after gonadotropin stimulation, were analyzed. Semen from a fertile donor was used in all assays. INTERVENTIONS: Five groups of oocytes were considered: (1) immature, prophase I; (2) metaphase I; (3) metaphase II; (4) inseminated, unfertilized metaphase II; and (5) immature, prophase I oocytes matured in vitro to metaphase II. Oocytes were stored in salt solution (pH 7.2) and microbisected before assay. MAIN OUTCOME MEASURE(s): Tight binding of sperm to the zona pellucida under HZA conditions was evaluated after 4 hours of gametes coincubation. RESULTS: Metaphase II oocytes (groups 3 and 4) had significantly higher binding than other groups (P = 0.0001). The mean value of the difference between the two halves (hemizona) was not significant, thus showing a small intra-assay variation for all maturational stages. CONCLUSIONS: Full meiotic competence of human oocytes is associated with an increased zona pellucida-binding potential. 相似文献
2.
Ralf Henkel Susan Cooper Khalied Kaskar Wolf-Bernhard Schill Ursula-F. Habenicht Daniel R. Franken 《Journal of assisted reproduction and genetics》1995,12(9):644-649
Purpose
A total of 86 fresh and salt-stored immature human oocytes derived from postmortem ovarian tissue were used for this study.Methods
Oocytes were randomly incubated either in synthetic human tubal fluid medium (untreated zonae) or in a chemically defined medium (treated zonae).Results
Sperm binding experiments using hemizona assay conditions exhibited a 10-fold increased binding of sperm to treated compared to untreated oocytes (272.7±43 versus 24.3±15 sperm bound, respectively; P<0.0001). pH recordings during incubation showed elevated pH levels of 8.1 compared to pH 7.2 among treated and untreated zonae, respectively. Ultrastructural examination showed a spongy appearance of the surface of treated zonae, whereas untreated zonae appeared compact with smooth surface.Conclusions
The marked increase in sperm binding among treated zonae, together with the ultrastructural findings, suggest that the altered zona surface enhances sperm binding. The physiological maturational process of the zona pellucida might be manipulated in vitro, thus increasing sperm binding to the zona.Presented at the IXth World Congress on In Vitro Fertilization and Alternate Assisted Reproduction, April 3–7, 1995. Vienna, Austria. 相似文献
3.
Berbaum KS; el-Khoury GY; Franken EA Jr; Kathol M; Montgomery WJ; Hesson W 《Radiology》1988,168(2):507-511
The effect of knowledge of localizing symptoms and signs in the detection of fractures was studied. Forty radiographs of the extremities were examined twice by seven radiologists; the sessions were separated by 4 months. In 26 cases, a subtle fracture was present; 14 cases were normal. In half of the cases at each session, the precise location of pain, tenderness, or swelling was provided. The observer was asked to determine if the case was normal or abnormal (provide the exact location of the fracture) and to indicate the degree of confidence in the diagnosis. Responses were converted to a numeric scale for analysis. Analysis of receiver operator characteristic parameters indicates that clues regarding location of trauma facilitate detection of fractures. The improvement is based largely on an increased true-positive rate without an increased false-positive rate, regardless of the decision criteria of the radiologist (overall willingness to "overread" or "underread"). This has direct clinical applicability and reinforces the plea of radiologists for precise clinical information. 相似文献
4.
The authors reexamined a suspected difference in the effects of clinical information upon detection of nodules vs. more diverse lesions by directly incorporating classification specificity into detection ROC analysis. Categorical prompts, correct for specific abnormalities, led to detection superior to unprompted reading when non-nodule trials (various lesion types) were analyzed. Trials that contained pulmonary nodules, or contained no lesions but had been preceded by "possible tuberculosis" or "rule out metastatic disease" prompts, failed to demonstrate the diagnostic prompt superiority. Perceptual responses may differ when nodules are compared with more complex lesions. 相似文献
5.
Seventeen couples (13%) were selected from a group of 129 infertilepatients according to the following criteria: (i) unexplainedinfertility for 3 years and (ii) <50% shaking spermatozoaduring SCMC testing. The couples were tested for sperm antibodiesafter a complete diagnostic work-up schedule. Post-coital testswere performed during the first menstrual cycle of the wife,followed by SCMC and sperm antibody titre testing. Ten malesand seven females were thus treated with 96 mg methylprednisolone.Nine (52%) of the 17 with sperm antibodies achieved a pregnancy.The results of the SCMC test were in all the cases indicativeof the actual sperm antibody titre. Reduction of the antibodytitre and a decrease in the percentage of shaking spermatozoaas detected by the SCMC test correlated well with the pregnancyrate amongst the patients. 相似文献
6.
Sleep and EEG spectra in the rabbit under baseline conditions and following sleep deprivation 总被引:3,自引:0,他引:3
The 24-hr sleep-wake distribution and power spectra of the electroencephalogram were determined in rabbits that had been implanted with cortical and hippocampal electrodes. A diurnal preference for sleep was observed. The spectral power density in nonrapid eye movement sleep (NREM sleep) of the cortex showed a decreasing trend in most frequencies within the 12-hr light period. In the 12-hr dim period no clear trend was present. Most hippocampal EEG frequencies decreased in NREM sleep in the first two hours of the light period, and thereafter stayed on a constant level. Sleep deprivation elicited the following changes: a prolonged increase of NREM sleep and a short increase of REM sleep; in the cortex, an increase of slow-wave activity (SWA; power density in the 0.25-2.0 Hz frequency band) in NREM sleep, which declined in the course of recovery; an enhancement of slow-wave (1.25-3 Hz) and theta (6.25-7 Hz) activity in REM sleep. The hippocampus showed an increase in NREM sleep power density in almost all frequencies. In REM sleep the hippocampus exhibited an increase in power density in the 6.25-7 Hz and 12.25-13 Hz bands, whereas in the 7.25-8 Hz band the values were below baseline. The results show that SWA in NREM sleep and theta activity in REM sleep are enhanced by sleep deprivation, as has been observed in other mammalian species. The EEG changes in the hippocampus resembled those in the cortex. 相似文献
7.
Dr. Eric Delcourt Philippe Franken Andre Lenaers 《European journal of nuclear medicine and molecular imaging》1985,11(4):123-126
When performing equilibrium radionuclide angiocardiography with two successive acquisition views, absolute left-ventricular volumes can be calculated using an internal standard generated by a computer in the left-ventricular cavity. The method is based on the computed ratio of maximum to global activity in the 40°-left-anterior-oblique view after background correction and on the measured depth of the left ventricle in almost-orthogonal, 30°-left-posterior-oblique Fourier first-harmonic images. The method does not require blood sampling or correction for self attenuation. The intra- and interobserver reproducibility is excellent, even in patients with severe impairment of the ventricular-contractility pattern. When compared with a classical method requiring venous-blood counting and an attenuation correction factor, the accuracy of the internalstandard method was fairly good, with a regression coefficient of 0.90. 相似文献
8.
Franken N Vanbree C Streefkerk J Kuper I Rodermond H Kipp J Haveman J Barendsen G 《Oncology reports》1997,4(5):1073-1076
To investigate radiosensitization by halogenated pyrimidines in human cells, SW-1573 lung tumor cells were grown in absence or presence of 4 mu M of iododeoxyuridine (IdUrd). Cell survival after irradiation with gamma-rays from a Cs-137 source with single doses up to 8 Gy, was determined by clonogenic assay, Radiosensitization by IdUrd was observed in both exponentially growing and plateau phase cells. Linear-quadratic analyses of the radiation survival curves demonstrated that radiosensitization was mainly expressed by an increase of the value of alpha (determining the initial slope of the survival curve) which can be interpreted as an enhancement of fixation of potentially lethal damage (PLD). The value of beta (determining the curvature of the survival curve), which might be attributed to enhanced interaction or to fixation of sublethal damage (SLD), was not influenced. In view of clinical applications of IdUrd it is of interest that radiosensitization has its main effect in the low dose region of the cell survival curve, described by the linear term alpha D. 相似文献
9.
F. De Geeter F. R. Franken F. F. Knapp Jr A. Bossuyt 《European journal of nuclear medicine and molecular imaging》1994,21(4):283-291
Contradictory data have been published on the relative behaviour of fatty acids and flow tracers during the subacute stage of myocardial infarction. Therefore, the present study was set up (1) to investigate the potential occurrence of mismatches between -methyl-iodophenyl pentadecanoic acid (BMIPP), a fatty acid analogue, and Sestamibi, and to describe their nature, and (2) to relate these mismatches to clinical characteristics such as whether or not thrombolysis or percutaneous transluminal coronary angioplasty (PTCA) had been performed. Twenty-six patients were studied within 2 weeks after myocardial infarction. Sestamibi and BMIPP single-photon emission tomography (SPET) were performed within 4 days of one another. Activity of both tracers was scored in 16 basal, 16 midventricular and 8 apical segments, using a four-point grading system: 3 = normal (65% of maximum activity), 2 = mildly decreased (45%–64%), 1 = moderately decreased (25%–44%), 0 = severely decreased (0%–24%). Coronary arteriography was obtained during the same hospital stay. Four hundred and seventy-seven segments out of 1040 studied were abnormal for at least one tracer: 197 with higher Sestamibi activity (group I), 226 with equal scores for Sestamibi and BMIPP (group II) and 54 with higher BMIPP activity (group III). Seventy-five percent of group I segments and 84% of group III segments were found in infarct-related artery territories. Group I segments were associated with acute thrombolysis and/or PTCA (P < 0.01), and with the absence of prior infarction in the territory of the infarct-related artery (P < 0.001). Group III segments were associated with the absence of thrombolysis or PTCA (P < 0.001), with occlusion of the infarct-related artery (P < 0.001), with previous infarction in the same territory (P < 0.001) and with a- or dyskinesia in this territory (P < 0.001). These data could support the interpretation that areas in which the uptake of BMIPP is more decreased than that of Sestamibi (group I) are due to delayed recovery of fatty acid metabolism after reperfusion, whereas those with higher BMIPP than Sestamibi activity (group III) are accounted for by the enhanced metabolism induced by passive systolic wall stretch. 相似文献
10.