A full-term pregnancy early in life reduces lifetime risk of developing breast cancer, and the effect can be mimicked in rodents by full-term pregnancy or shortterm treatment with exogenous estrogen and progesterone. To gain insight into the protective mechanism, 15 3-mo-old postpubertal virgin Lewis rats were randomly assigned to three groups: control (C), pregnancy (P), or hormone (H). The P group animals underwent a full-term pregnancy, and H group animals were implanted subcutaneously with silastic capsules filled with ethynyl estradiol and megesterol acetate for 21 days. C and P animals were implanted with sham capsules. On day 21 capsules were removed, which was followed by a 49-day involution period, euthanasia, and mammary tissue collection. Global gene expression was measured using Rat Genome 230.2 Arrays. Histological analysis revealed that P and H treatments induced sustained morphological changes in the mammary gland with significantly increased percentages of mammary parenchyma and stromal tissues and higher ratio of stroma to parenchyma. Transcriptome analysis showed that P and H treatments induced sustained global changes in gene expression in the mammary gland. Analysis of commonly up-and downregulated genes in P and H relative to C treatment showed increased expression of three matrix metallopeptidases (Mmp3, 8, and 12), more differentiated mammary phenotype, enhanced innate and adaptive immunity, and reduced cell proliferation and angiogenic signatures. The sustained morphological and global gene expression changes in mammary tissue after pregnancy and hormone treatment may function together to provide the protective effect against breast cancer. breast cancer protection; hormone; pregnancy BREAST CANCER IS ONE OF THE most common cancers in women and affects nearly 10% of all women in US. In the year 2009, 192,370 new cases of invasive and 62,280 new cases of in situ breast cancer were estimated to have occurred, with 40,170 estimated deaths (3). Various epidemiological studies have revealed that multiple factors including hormones, genetics, reproductive history, radiation, socio-economic status, place of residence, ethnicity, and the environment affect the incidence of breast cancer (9,19,28,29,50,51,60). It has been shown that full-term pregnancy early in life has a protective effect on women against the risk of breast cancer irrespective of genetic background, age, race, or ethnic background (2,37,39,40,64,65,72). For instance, Lambe et al. (1996) (39, 40) and Albrektsen et al. (2005) (2) reported that full-term gestation in a woman younger than 24 yr of age reduces her lifetime risk of developing breast cancer, and this parity-induced protection against breast cancer is significantly affected by the total number of pregnancies. The epidemiological data on breastfeeding and breast cancer risk in humans also show that prolonged breast-feeding confers additional protection against breast cancer (17). However, aborted pregnancies are not associated with decreased risk for breast cancer (8).A ...
SummaryBackground: Prevention and management of chronic conditions is a priority for many healthcare systems. Personal health records have been suggested to facilitate implementation of chronic care programs. However, patients' attitude towards personal health records (PHRs) can significantly affect the adoption rates and use of PHRs. Objectives: to evaluate the attitude of patients with Type II diabetes towards using a PHR to manage their condition. Methods: We used a cross-sectional exploratory pilot study. Fifty-four (54) patients used a PHR to monitor and record their blood glucose levels, diet, and activities for 30 days, and to communicate with their clinicians. At the end of the study, patients responded to a survey based on three constructs borrowed from different technology acceptance frameworks: relative advantage, job fit, and perceived usefulness. A multivariate predictive model was formed using partial least squaring technique (PLS) and the effect of each construct on the patients' attitude towards system use was evaluated. Patients also participated in a semi-structured interview. Results: We found a significant positive correlation between job fit and attitude (JF → ATT = +0.318, p<0.01). There was no statistical evidence of any moderating or mediating effect of other main constructs or any of the confounding factors (i.e., age, gender, time after diagnosed) on attitude. Conclusion:The attitude of patients towards using PHR in management of their diabetes was positive. Their attitude was mainly influenced by the extent to which the system helped them better perform activities and self-manage their condition.
Cows exposed to short day photoperiod (SD, 8L:16D) during the 60-day nonlactating period prior to parturition produce more milk in their subsequent lactation compared with cows exposed to long day photoperiod (LD, 16L:8D). Although this response is well established in dairy cows, the underlying mechanisms are not understood. We hypothesized that differential gene expression in cows exposed to SD or LD photoperiods during the dry period could be used to identify the functional basis for the subsequent increase in milk production during lactation. Pregnant, multiparous cows were maintained on an SD or LD photoperiod for 60 days prior to parturition. Mammary biopsies were obtained on days -24 and -9 relative to parturition and Affymetrix GeneChip Bovine Genome Arrays were used to quantify gene expression. Sixty-four genes were differentially expressed (P ≤ 0.05 and fold-change ≥ |1.5|) between SD and LD treatments. Many of these genes were associated with cell growth and proliferation, or immune function. Ingenuity Pathway Analysis predicted upstream regulators to include TNF, TGF-β1, interferon-γ, and several interleukins. In addition, expression of 125 genes was significantly different between day -24 and day -9; those genes were associated with milk component metabolism and immune function. The interaction of photoperiod and time affected 32 genes associated with insulin-like growth factor I signaling. Genes differentially expressed in response to photoperiod were associated with mammary development and immune function consistent with the enhancement of milk yield in the ensuing lactation. Our results provide insight into the mechanisms by which photoperiod affects the mammary gland and subsequently lactation.
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