instruction:
In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.
question:
Context: To determine whether fertilization rate serves as a biological assay, reflects oocyte quality, and may be used to help predict patient implantation rate.', 'Retrospective cohort study.', 'Academic center.', 'Couples undergoing 3603 in vitro fertilization (IVF) cycles from 2001 to 2007.', 'None.', 'We compared the implantation rate among cycles with high versus low fertilization rate. Univariate analyses were performed to determine the association of implantation rate with potential confounding variables: age, day-3 follicle-stimulating hormone level, day-3 estradiol level, antral follicle count, oocyte number, cycle attempts, embryo grading, and number of embryos transferred. Multivariate analysis was then performed to determine whether the fertilization rate remained an independent predictor.', 'Cutoffs for fertilization rate were 50% for intracytoplasmic sperm injection (ICSI) and 75% for conventional insemination. Higher ICSI fertilization was statistically significantly associated with the implantation rate (25.2% vs. 17.8 %). After adjusting for variables associated with implantation rate, fertilization rate for ICSI remained a strong independent predictor of implantation. Higher conventional insemination fertilization was statistically significantly associated with implantation (32.1% vs. 25.7%) and remained a statistically significant predictor after adjustment.\Question: Is fertilization rate an independent predictor of implantation rate?
answer:
Fertilization is a strong, independent predictor of implantation rate and may be useful in modeling to guide decision making for the number of embryos to transfer.


question:
Context: To determine whether testosterone levels change as women with the polycystic ovary syndrome (PCOS) grow older.', 'A follow-up cross-sectional study of a cohort of women with PCOS identified up to 20-25 years ago.', 'Women with PCOS were recruited primarily from practice records between 1970 and 1990. Voter registration tapes and household directories were used to identify age-, race-, and neighborhood-matched controls.', 'Eighty-four women with PCOS, 20-57 years of age, and 37 age-matched controls participating in a study of the risk for cardiovascular disease in women with PCOS.', 'Clinical data were collected by questionnaire and fasting blood samples were obtained randomly throughout the menstrual cycle.', 'Total and non-SHBG-bound testosterone levels.', 'Total and non-SHBG-bound testosterone levels were similar in women with PCOS who were 20-42 years of age but were reduced by approximately 50% among women 42-47 years of age and remained stable in women older than 47 years of age. Testosterone levels were increased in younger and older women with PCOS compared with controls but were similar to controls in women 42-47 years of age.\Question: Do serum testosterone levels decrease in middle age in women with the polycystic ovary syndrome?
answer:
Hyperandrogenism partly resolves before menopause in women with PCOS. This change may explain the tendency of women with PCOS to cycle regularly as they grow older. Testosterone levels remain elevated in older women with PCOS, however, and may contribute to their increased risk for cardiovascular disease, endometrial cancer, and other diseases.


question:
Context: The high affinity IgE receptor (FcepsilonRI) on mast cells and basophils is up-regulated by its own ligand IgE; however, the mechanism is unknown.', 'To study the IgE-mediated effect on FcepsilonRI on basophils by using the human basophilic cell line KU812.', 'Expression of cell surface FcepsilonRI was assessed by flow cytometry. Western blot technique was used to illustrate tyrosine-phosphorylation and the Ca2+ level in KU812 was measured by fluorescence of Fura-2. Soluble specimens of the alpha-chain from FcepsilonRI (FcepsilonRIalpha) were obtained by lysing 107 KU812 pr. mL. FcepsilonRIalpha was detected by a sandwich immunoradiometric assay employing the IgE-binding capacity of FcepsilonRIalpha in conjunction with a monoclonal antibody. Polyclonal rabbit anti-FcepsilonRIalpha was used for detection of FcepsilonRIalpha by Western blotting.', 'We found that monomeric IgE did not induce tyrosine-phosphorylation in KU812, which was the case when stimulating with IgE cross-linked by anti-IgE binding. Further, only cross-linking of IgE, but not monomeric IgE, increased the Ca2+ level. Using the immunoradiometric assay, we found a temperature dependent reduction in the amount of FcepsilonRIalpha. Samples incubated at 37 degrees C for 5 h displayed a 16-fold decrease in the FcepsilonRIalpha level compared with samples incubated at 4 degrees C. In the presence of IgE the reduction at 37 degrees C was only threefold.\Question: Does monomeric immunoglobulin E stabilize FcepsilonRIalpha from the human basophil cell line KU812 by protecting it from natural turnover?
answer:

These results indicate that IgE does not induce intracellular signals in KU812, i.e., tyrosine-phosphorylation or Ca2+ release. Instead it appears that FcepsilonRIalpha is an unstable protein that IgE stabilizes and thereby protects from a temperature dependent turnover.