Factors modulating preferences of female house mice for males differing in t-complex genotype: Role of t-complex genotype,genetic background,and estrous condition of females

The present study investigates factors mediating odor and social preferences in female house mice (Muc domesticus) based on the t-complex geontype of males. Previous studies in this laboratory showed that females prefer the odors of wild-type (+/+) males over those that carry lethal genes (+/t). The purpose of this study was to determine the genetic, hormonal, and environmental factors that regulate these preferences. The variables examined include t-complex genotype, genetic background, estrous condition of test females (+/+ or +/t), and genotype of the test female's parents. Results indicate that female preferences for +/+ males are dependent upon the t-complex genotype and estrous condition of test females. Only +/t females in estrus showed preferences for +/+ males. Estrous cycle condition effects were seen in both wild (+/+w ⁵) and inbred (129 +/tw ⁵)females. Homozygous females (+/+) and diestrous females of both geno-types did not demonstrate preferences for either +/+ or +/t males.     

Electrical impedance scanning for the early detection of breast cancer in young women: preliminary results of a multicenter prospective clinical trial.

PURPOSE: To evaluate the feasibility and patient satisfaction with electrical impedance scanning (EIS) for early detection of breast cancer in young women. METHODS: Women undergoing screening clinical breast examination, imaging, or biopsy were eligible for EIS examination with T-Scan 2000ED (Mirabel Medical Systems, Austin, TX). Multiple logistic regression analysis evaluated the association between clinical variables and EIS performance. Patients completed a screening EIS satisfaction questionnaire (1 = least satisfied to 5 = most satisfied). RESULTS: Twenty-nine cancers were identified among 1,103 women. Sixty-six percent (19 of 29) of cancers were nonpalpable and 55% (16 of 29) were in women age < or = 50 years. EIS sensitivity and specificity in women younger than 40 years was 50% and 90%, respectively. Exogenous estrogen use (P < .001) and menopausal status (P = .007) correlated significantly with EIS performance. False-positive rates were increased in postmenopausal women and those taking exogenous hormones. No correlation was evident between EIS performance and family history, prior breast cancer, breast density, or palpability. EIS-positive women younger than age 40 were 4.5 times more likely to have breast carcinoma than were women randomly selected from the general population. Patients were highly satisfied with the comfort, speed, and reporting of EIS screening (mean score, 4.8). CONCLUSION: EIS seems promising for early detection of breast cancer, and identification of young women at increased risk for having the disease at time of screening. Positive EIS-associated breast cancer risk compares favorably with relative risks of conditions commonly used to justify early breast cancer screening. Patients are satisfied with a screening paradigm involving breast EIS.     

Environmental influences on the preferences of wild female house mice for males of differing t-complex genotypes

Twenty-five percent of wild house mice are heterozygous (+/t) for a deleterious, recessive mutation at the t complex. In previous studies we have demonstrated that wild female house mice can discriminate +/+ from +/t males and show strong preferences for the odors of males who do not carry t mutations. In the present study we examine the extent to which preferences of +/+ female mice are influenced by the genotype of their parents and or littermates. Our data indicate that when +/+ females are reared by two +/+ parents, they exhibit strong preferences for the odors of +/+ males. In contrast, when a +/+ female is reared by one +/+ and one +/t parent she shows no preference for males of either genotype. A second experiment using mice carrying recombinant chromosomes indicates that the genes responsible for the parental (or family) odor cue are not the deleterious t mutations per se but rather other genes linked to these mutations.This work was funded by a grant from the Research Council of Rutgers University.     

Satisfaction with breast cancer screening and future screening participation.

BACKGROUND: To measure satisfaction with an investigational breast cancer risk screening technique [electrical impedance scanning (EIS)] and to investigate the relationship between satisfaction and willingness to return for follow-up examination one year later. MATERIAL/METHODS: 2727 women volunteers (age 18-45 years, military healthcare beneficiaries) underwent an EIS exam [reported as "negative" (average risk) or "positive" (high risk)]; then they filled out a questionnaire assessing satisfaction with the procedure. One year later, women were invited for follow-up screening. RESULTS: Satisfaction score was significantly related to EIS exam result (higher for women with negative exams), importance assigned to breast cancer screening, and family history of breast cancer. However, satisfaction was not related to scheduling a visit the following year for a follow-up examination. The only satisfaction component predicting return was satisfaction with exam reporting for participants with positive exam results. Return was related positively to age and race/ethnicity; older women and Hispanic women were more likely, while African American women were less likely, to return for follow-up. CONCLUSIONS: Factors affecting breast cancer screening participation among younger women are diverse and complex. Further study and delineation of such factors is necessary to understand how best to tailor breast cancer education programs in young women.     

Breast electrical impedance and estrogen use in postmenopausal women.

OBJECTIVES: To examine the potential for using electrical impedance measurements on the breast as an indicator of estrogen activity in breast tissue. METHODS: Eighty-six postmenopausal women were examined with TS2000, a device that measures electrical capacitance and conductance on the breast. Seventy women had undergone natural menopause (NM) and 16 had had a hysterectomy/ovarectomy. Twenty-one women were using estrogen replacement therapy (ERT). Each woman had electrical impedance measured over several frequencies on the nipple sector of both breasts. We analyzed capacitance and conductance at 200 and 1100 Hz and the slopes and intercepts of regression lines relating capacitance and conductance to the natural log of frequency. RESULTS: Type of menopause (natural or induced) was not statistically related to any measured variable. The number of years since the start of menopause was statistically related to all measured variables. Overall, levels of capacitance and conductance decreased as the number of years since the start of menopause increased. Women who used ERT had a statistically higher level of nipple conductance at 200 Hz than did women who did not use ERT. CONCLUSIONS: The pattern of electrical measurements on the nipple (and in particular conductance at 200 Hz) is correlated with the pattern of estrogen changes after menopause. These data indicate that electrical measurements might be a useful, non-invasive assay of estrogen activity in breast tissue.     

Female discrimination of male odors correlated with male genotype at the T locus: A response to T-locus or H-2-locus variability?

Female house mice (Mus musculus), derived from several populations of wild-caught mice, were tested for their ability to discriminate between males whose genotype at the T locus was +/+ and those whose genotype was +/t, using odor cues alone. Females spent more time near the odors or +/+ males than near the odors of +/t males. This preference was independent of the T-locus genotype of the female and the particular type of t allele carried by either the male or the female. A female's preference, however, did appear to be related to the genotype of her parents. Females with one +/t parent were more likely to prefer +/t males than were females whose parents were both +/+. In a second experiment 18 females were tested with odors from soiled bedding of recombinant males whose genotype varied at the T locus but who were similar at the H-2 locus. As a control, these 18 females were also tested with bedding of wild-derived +/+ and +/t^{w semilethal} males. Females tested with recombinant males preferred odors of males not carrying lethal t alleles over those of males carrying two lethal t alleles, indicating that T-locus variability, not H-2-locus variability, is responsible for odor differences between +/+ and +/t males. Female responses to odors of recombinanat males did not differ from those to odors of +/+ and +/t^{w semilethal} males. Responses of mice to odor differences associated with T-locus variability may have evolved independently of responses to odor variability associated with the H-2 locus.This work was supported by NIH Grant HD 15997-01.     

Electrical Impedance Scanning of Thyroid Nodules Before Thyroid Surgery: A Prospective Study

Background Electrical impedance scanning (EIS) is a novel imaging technique based on differential electrical conductivity and capacitance of malignant and normal human tissues. The aim of this study was to evaluate the accuracy of EIS in the detection of thyroid malignancies.Methods Patients with thyroid nodules scheduled for thyroid surgery were eligible for the study. Enrolled patients underwent EIS with a T-Scan 2000ED. Nodule location, size, and type (cystic vs. solid) measured by ultrasound, cytology results, thyroid conductivity, and capacitance calculated by EIS were recorded. EIS results were interpreted as positive or negative for malignancy and compared with final histopathology results. Study end points included EIS accuracy, sensitivity, specificity, negative and positive predictive values, and false-positive and false-negative rates.Results Sixty-four patients were enrolled onto the study, and all underwent either lobectomy-isthmusectomy (20%) or total thyroidectomy (80%). The mean tumor diameter was 2.64±14.8 mm. Thyroid cancers were identified by histology in 30 patients (46.9%). There were 11 false-positive and four false-negative cases. The overall diagnostic accuracy of EIS was 76.6% (49 of 64 correct diagnoses). The sensitivity and specificity of EIS were 86.7% (26 of 30 true positive) and 67.6% (23 of 34 true negative), respectively. The corresponding positive and negative predictive values were 70.3% and 85.2%.Conclusions EIS is a potentially useful imaging modality for differentiating thyroid neoplasms. If these results are confirmed in large-scale trials, EIS may be an important part of the evaluation of thyroid nodules.