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Laboratories↗
Biomedical subjects
Bahjat Qaqish
Publications and source records attributed to Bahjat Qaqish.
A new statistical approach demonstrated menstrual patterns during the menopausal transition did not vary by age at menopause.
OBJECTIVE: To describe population mean, variance, and correlation of cycle length across the life span and by age at menopause and age at menarche using a new statistical approach. STUDY DESIGN AND SETTING: Data from the Tremin Trust (n=997), a prospective menstrual diary study, was analyzed. Marginal models with generalized estimating equations were used to describe changes in menstrual parameters across the reproductive life span. RESULTS: During the menopausal transition, the increase in standard deviation preceded that in mean by 2 to 6 years. Although beginning earlier in women with earlier menopause, increases in mean and variance for women with different ages at menopause were parallel. Women with later menopause had longer cycles throughout life and longer, more variable cycles during the transition. CONCLUSION: The transition from late reproductive life to early menopausal transition appears to begin in the late thirties when variability of cycle length increases. Patterns of change in menstrual function during the menopausal transition do not differ by age at menopause; thus, differences in age at menopause are likely to reflect changes in the timing and not changes in the process of ovarian senescence, at least for the normative ages of menopause.
Adolescent↗
Familial aggregation and genome-wide linkage analysis of carotid artery plaque: the NHLBI family heart study.
OBJECTIVE: To evaluate familial and genetic influences on carotid artery plaque, a qualitative marker of the systemic burden of atherosclerosis. METHODS: The design was a cross-sectional study of 2,223 members of 525 randomly-ascertained families and 2,514 members of 589 high coronary heart disease (CHD) risk families from 4 U.S. communities. RESULTS: The prevalence of plaque was 33, 36, and 47%, respectively, among probands with 0, 1, and 2 or more first-degree relatives with a history of CHD. There was evidence of sibling aggregation of plaque in random families (OR = 1.89; 95% CI: 1.44, 2.48), but associations were substantially attenuated when adjusted for major cardiovascular disease risk factors. A genome scan with 420 microsatellite markers revealed no regions of significant or suggestive linkage for plaque in 342 affected sibling pairs, although suggestive linkage (LOD score: 2.43) was found on chromosome 2p11.2 (D2S1790) in pairs aged 55 years or younger. Other markers with nominal evidence for linkage (p < 0.05) were found on chromosomes 2p25, 2q24-q32, 6q21-q23, 7p12-p21, 7q11-q21, 8q24, 12q12-q13, 18p11, 21q21 and Xp11, Xq12, and Xq24. CONCLUSIONS: There was modest familial aggregation of carotid artery plaque, but a genome-wide scan indicated no regions of significant or suggestive linkage.
Adult↗
Sampling strategy for prostate tissue microarrays for Ki-67 and androgen receptor biomarkers.
OBJECTIVE: To develop an optimal sampling strategy for tissue microarrays using automated digital analysis for androgen receptor (heterogeneous expression) and the cellular proliferation marker Ki-67 (homogeneous expression and evaluated by others using nonautomated methods). STUDY DESIGN: Tissue microarrays were constructed from 23 radical prostatectomy specimens and immunostained for androgen receptor expression and cellular proliferation. Automated digital image analysis was used, and the minimum number of cores necessary to capture variance change <3% was determined. Androgen receptor immunostaining was described by percent positive nuclei (PPN) and mean optical density (MOD). RESULTS: Androgen receptor PPN variance measurements showed that 5 cores should be obtained when a single block of a radical prostatectomy specimen contained cancer. If all of 15 blocks contained cancer, 2 cores should be obtained from each of 6 blocks. An optimal sampling strategy was developed for androgen receptor PPN, androgen receptor MOD and Ki-67 PPN. CONCLUSION: The selection of the number of cores to sample is a tradeoff between the number of cores available that contain cancer and the amount of work involved in the analysis. Sampling no fewer than 5 but no more than 12 cores per radical prostatectomy specimen can capture tissue heterogeneity.
Aged↗
Comparison of full-field digital mammography to screen-film mammography with respect to diagnostic accuracy of lesion characterization in breast tissue biopsy specimens.
RATIONALE AND OBJECTIVES: This study was performed to investigate whether full-field digital mammography (FFDM) is at least as accurate as screen-film mammography with respect to breast lesion characterization. MATERIALS AND METHODS: Seventy-nine breast surgical specimens were obtained by means of preoperative needle localization with surgical excision from 79 patients. The specimens were imaged with both screen-film mammography and FFDM. Six radiologists specialized in breast imaging analyzed both sets of images and characterized the visualized lesions on a five-point scale: 1, definitely not malignant; 2, probably not malignant; 3, possibly malignant; 4, probably malignant; and 5, definitely malignant. Receiver operating characteristic curve analysis of the data was then performed to assess for differences between modalities in the radiologists' ability to predict breast malignancy. RESULTS: The areas under the receiver operating characteristic curves for the prediction of breast malignancy in surgical biopsy specimens were not statistically significantly different for FFDM and screen-film mammography. CONCLUSION: The results demonstrate that with breast surgical specimens, FFDM is similar in diagnostic accuracy to screen-film mammography.
Adult↗
Increasing use of mammography among older, rural African American women: results from a community trial.
OBJECTIVES: A community trial was undertaken to evaluate the effectiveness of the North Carolina Breast Cancer Screening Program, a lay health advisor network intervention intended to increase screening among rural African American women 50 years and older. METHODS: A stratified random sample of 801 African American women completed baseline (1993-1994) and follow-up (1996-1997) surveys. The primary outcome was self-reported mammography use in the previous 2 years. RESULTS: The intervention was associated with an overall 6 percentage point increase (95% confidence interval [CI] = -1, 14) in community-wide mammography use. Low-income women in intervention counties showed an 11 percentage point increase (95% CI = 2, 21) in use above that exhibited by low-income women in comparison counties. Adjustment for potentially confounding characteristics did not change the results. CONCLUSIONS: A lay health advisor intervention appears to be an effective public health approach to increasing use of screening mammography among low-income, rural populations.
Black or African American↗