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Breast cancer has been suggested to potentially have prenatal origins. We examined associations between birth weight, body mass index (BMI) at four-time points over 25 years of adulthood, and risk of postmenopausal breast cancer, with emphasis on whether the association between birth weight and risk of breast cancer was mediated by weight and height changes over the adult life course. Postmenopausal women (n = 70,397) aged 50–79 years without breast cancer at enrollment (1993–1998) were followed up to 25 years. Weight and height were measured at baseline. Birth weight, and weights at ages 18, 35 and 50 were self-reported. Breast cancer cases were centrally adjudicated. Compared to women with birth weight of 6–8 pounds, women with birth weight of <6 pounds had lower risk of breast cancer (HR = 0.88 95% CI: 0.79–0.99). 44% and 21% of the relationship between birth weight and breast cancer risk was mediated by adult height and weight at baseline, respectively. Birth weight of 8 pounds or more was not associated with risk of postmenopausal breast cancer. Weight gain in adulthood was associated with increased risk of breast cancer regardless of time periods. In conclusion, lower birthweight was associated with lower risk of postmenopausal breast cancer, and this reduction in risk was significantly mediated by childhood or adolescent growth, especially by adult height. Our data suggest that reaching and maintaining a healthy weight during adulthood is key in the prevention of breast cancer.  相似文献   
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The WHI found an unexpected reduced breast cancer risk in women using CEE alone. We hypothesized CEE alone induces estrogen hydroxylation along the 2-pathway rather than the competing 16-pathway, a pattern linked to reduced postmenopausal breast cancer risk. One thousand eight hundred and sixty-four women in a WHIOS case–control study of estrogen metabolism and ovarian and endometrial cancer were studied of whom 609 were current E + P users (351 used CEE + MPA), while 272 used E alone (162 used CEE). Fifteen EM were measured, and analyses were conducted for each metabolite, hydroxylation pathway (2-, 4-, or 16-pathway) and ratios of pathway concentrations using inverse probability weighted linear regression. Compared to E + P users, all EM were higher in E alone users (significant for unconjugated estrone, total/conjugated estradiol, total/unconjugated 2-methoxyestrone, 4-methoxyestrone and unconjugated estriol). The relative concentrations of 2- and 4-pathway EM did not differ between the MHT users (2-pathway EM comprised 15% and 4-pathway EM <2% of the total), but 16-pathway EM were lower in E alone users (p = 0.036). Ratios of 2- and 4-pathway EM compared to 16-pathway EM were significantly higher in E alone compared to E + P users. Similar but not significant patterns were observed in CEE-alone and CEE + MPA users. Our data suggest that compared to E + P users, women using E alone have more extensive metabolism via the 2- vs. the competing 16-pathway. This is consistent with epidemiologic evidence of reduced postmenopausal breast cancer risk associated with this metabolic profile and may provide a clue to the breast cancer risk reduction in CEE alone users during the WHI.  相似文献   
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The types of midfacial fractures and their complexity were evaluated in admissions to the Maryland Institute of Emergency Medical Service Systems (MIEMSS) during the years of 1984 to 1988. Two hundred and sixty-eight LeFort fractures were treated and followed (3.2 percent of admissions). One half (50 percent) had skull fractures and 40 patients (15 percent) had LeFort, skull and mandibular fractures. Isolated nasoethmoidal fractures were observed in 176 patients and in 107 patients (39 percent) of patients with LeFort fractures. Isolated mandibular fractures were observed in 321 patients and in 104 patients with LeFort fractures (39 percent). Eleven percent of patients had midfacial, nasoethmoidal and frontal sinus fractures. Six percent of patients had midfacial, frontal bone, frontal sinus and nasoethmoidal fractures (Cranial Base Crush Syndrome). Twenty two percent of patients had LeFort and frontal sinus fractures. Reconstruction of multiple area injuries is simplified by a highly organized treatment sequence that conceptualizes the face in two groups of two units. Each unit is divided into sections, and each section is assembled in three dimensions. Sections are integrated into units and units into a single reconstruction. Conceptually, in each unit, facial width must first be controlled by orientation from cranial base landmarks. Projection is then (and often reciprocally with width) established. Finally, facial length is set both in individual units and in the upper and lower face. Soft tissue is considered the "fourth dimension" of facial reconstruction. Bone reconstruction should be completed as early as possible to minimize soft tissue shrinkage, stiffness and scarring of soft tissues in nonantomic positions.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
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Spring-mediated mandibular distraction osteogenesis   总被引:4,自引:0,他引:4  
Successful performance of distraction osteogenesis requires rigorous patient compliance with a daily activation regimen of a percutaneous screw. Previous clinical studies have found that failure of patient compliance with this regimen is the most common complication leading to technical failure of the distraction process. The authors have developed an internalized spring-mediated device for mandibular distraction osteogenesis that can potentially abrogate the risks associated with patient compliance by allowing for automated distraction across an osteotomy. Twenty adult New Zealand White rabbits underwent unilateral mandibular osteotomy. A segment of nickel-titanium shape memory alloy reinforced at both ends with a pinball was fashioned into an inferiorly based arc and secured to the mandible with stainless steel wire. On postoperative day 12, spring activation commenced by cutting a wire binding the two pinballs to one another. Animals were observed for 6 weeks before they were killed. Radiographic studies and decalcified histologic analysis were performed on extracted mandibles. Temperature- and displacement-dependent properties of the shape memory alloy were also examined. Five animals were excluded from the study due to infection, nonunion, or device failure. A mean distraction of 1.2 mm in the distracted hemimandible relative to the nonoperated hemimandible was found (P <.001, two-tailed paired t test). The maximum distraction achieved in an experimental specimen using the spring distractor was 3.7 mm. There were no other histologic or radiographic differences found between study specimens and specimens subjected to traditional distraction methods. Biomechanical testing of the shape memory alloy revealed a temperature-dependent increase in force at body temperature compared with room temperature and a reduction in force with increased displacement of the spring. This study demonstrates the feasibility of spring-mediated distraction osteogenesis across an osteotomy. As the field of distraction osteogenesis matures, the next level of sophistication in the clinical development of devices will incorporate technology that permits fully internalized and automated distraction to occur.  相似文献   
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Summary

Some recent reports suggest that calcium supplement use may increase risk of cardiovascular disease. In a prospective cohort study of 74,245 women in the Nurses' Health Study with 24 years of follow-up, we found no independent associations between supplemental calcium intake and risk of incident coronary heart disease (CHD) and stroke.

Introduction

Some recent reports suggest that calcium supplements may increase cardiovascular disease (CVD) risk. The objective was to examine the independent associations between calcium supplement use and risk of CVD.

Methods

We conducted a prospective cohort study of supplemental calcium use and incident CVD in 74,245 women in the Nurses' Health Study (1984–2008) free of CVD and cancer at baseline. Calcium supplement intake was assessed every 4 years. Outcomes were incident CHD (nonfatal or fatal MI) and stroke (ischemic or hemorrhagic), confirmed by medical record review.

Results

During 24 years of follow-up, 4,565 cardiovascular events occurred (2,709 CHD and 1,856 strokes). At baseline, women who took calcium supplements had higher levels of physical activity, smoked less, and had lower trans fat intake compared with those who did not take calcium supplements. After multivariable adjustment for age, body mass index, dietary calcium, vitamin D intake, and other CVD risk factors, the relative risk of CVD for women taking >1,000 mg/day of calcium supplements compared with none was 0.82 (95 % confidence interval [CI] 0.74 to 0.92; p for trend <0.001). For women taking >1,000 mg/day of calcium supplements compared with none, the multivariable-adjusted relative risk for CHD was 0.71 (0.61 to 0.83; p for trend?<?0.001) and for stroke was 1.03 (0.87 to 1.21; p for trend?=?0.61). The relative risks were similar in analyses limited to non-smokers, women without hypertension, and women who had regular physical exams.

Conclusions

Our findings do not support the hypothesis that calcium supplement intake increases CVD risk in women.  相似文献   
8.
The first epigenome-wide association study of BMI identified DNA methylation at an HIF3A locus associated with BMI. We tested the hypothesis that DNA methylation variants are associated with BMI according to intake of B vitamins. In two large cohorts, we found significant interactions between the DNA methylation–associated HIF3A single nucleotide polymorphism (SNP) rs3826795 and intake of B vitamins on 10-year changes in BMI. The association between rs3826795 and BMI changes consistently increased across the tertiles of total vitamin B2 and B12 intake (all P for interaction <0.01). The differences in the BMI changes per increment of minor allele were −0.10 (SE 0.06), −0.01 (SE 0.06), and 0.12 (SE 0.07) within subgroups defined by increasing tertiles of total vitamin B2 intake and −0.10 (SE 0.06), −0.01 (SE 0.06), and 0.10 (SE 0.07) within subgroups defined by increasing tertiles of total vitamin B12 intake. In two independent cohorts, a DNA methylation variant in HIF3A was associated with BMI changes through interactions with total or supplemental vitamin B2, vitamin B12, and folate. These findings suggest a potential causal relation between DNA methylation and adiposity.  相似文献   
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