Gender differences in rat aortic smooth muscle cell matrix metalloproteinase-9

BACKGROUND: A predilection exists for men to develop abdominal aortic aneurysms (AAAs), but the reasons for this gender predisposition are not known. Matrix metalloproteinase-9 (MMP-9) has been implicated in both human and experimental AAAs. This investigation tested the hypothesis that male and female gender differences exist in the production of MMP-9 by rat aortic smooth muscle cells (RASMCs). STUDY DESIGN: In the first set of experiments, cultured male and female RASMCs were stimulated with interleukin-1 beta (IL-1beta) at 2 ng/mL. Messenger RNA was extracted from the RASMCs and gene expression of MMP-9 and tissue inhibitor of metalloproteinase-1 (TIMP-1), an MMP-9 inhibitor, was measured by quantitative real-time polymerase chain reaction. Cell culture media were collected for measurement of MMP-9 protein levels and MMP-9 activity by Western blotting and gelatin zymography, respectively. In the second set of experiments, male RASMCs were treated with 17-beta-estradiol (10(-10) to 10(-6) mol/L) and MMP-9 activity was measured. In the third set of experiments, male rats were pretreated with estradiol, and MMP-9 activity was measured in the media from explanted aortas. RESULTS: MMP-9 gene expression was 10-fold higher in male versus female RASMCs (p=0.003). MMP-9 protein levels (p=0.005) and gelatinolytic activities (p=0.01) were also greater in male than female RASMCs. TIMP-1 expression was fourfold higher in male versus female RASMCs (p<0.001). Estradiol-treated male RASMCs did not exhibit a decrease in MMP-9 activity. But aortic explants from male rats pretreated with 17-beta-estradiol had 60% less MMP-9 activity than explants from male controls (p=0.03). CONCLUSIONS: MMP-9 and TIMP-1 are greater in male than in female RASMCs. These findings support the tenet that gender-related differences in MMP-9 may contribute to AAA formation.     

Qualitative teamwork issues and strategies: coordination through mutual adjustment

Multidisciplinary research teams that include faculty, students, and volunteers can be challenging and enriching for all participants. Although such teams are becoming commonplace, minimal guidance is available about strategies to enhance team effectiveness. In this article, the authors highlight strategies to guide qualitative teamwork through coordination of team members and tasks based on mutual adjustment. Using a grounded theory exemplar, they focus on issues of (a) building the team, (b) developing reflexivity and theoretical sensitivity, (c) tackling analytic and methodological procedures, and (d) developing dissemination guidelines. Sharing information, articulating project goals and elements, acknowledging variation in individual goals, and engaging in reciprocity and respectful collaboration are key elements of mutual adjustment. The authors summarize conclusions about the costs and benefits of the process.     

Identifying the energy gap: magnitude and determinants of 5-year weight gain in midage women

OBJECTIVE: The aims of this study were to estimate average yearly weight gain in midage women and to identify the determinants of weight gain and gaining weight at double the average rate. RESEARCH METHODS AND PROCEDURES: The study sample comprised 8071 participants (45 to 55 years old) in the Australian Longitudinal Study on Women's Health who completed mailed surveys in 1996, 1998, and 2001. RESULTS: On average, the women gained almost 0.5 kg per year [average 2.42 kg (95% confidence interval, 2.29 to 2.54) over 5 years]. In multivariate analyses, variables associated with energy balance (physical activity, sitting time, and energy intake), as well as quitting smoking, menopause/hysterectomy, and baseline BMI category were significantly associated with weight gain, but other behavioral and demographic characteristics were not. After adjustment for all of the other biological and behavioral variables, the odds of gaining weight at about twice the average rate (>5 kg over 5 years) were highest for women who quit smoking (odds ratio = 2.94; 95% confidence interval, 2.17, 3.96). There were also independent relationships between the odds of gaining >5 kg and lower levels of habitual physical activity, more time spent sitting, energy intake (but only in women with BMI > 25 at baseline), menopause transition, and hysterectomy. DISCUSSION: The average weight gain equates with an energy imbalance of only about 10 kcal or 40 kJ per day, which suggests that small sustained changes in the modifiable behavioral variables could prevent further weight gain.     

The procoagulant potential of environmental particles (PM10)

Background and Aims: Epidemiology studies have shown that cardiovascular (CV) disease is primarily responsible for the mortality associated with increased pulmonary environmental particle (PM₁₀) exposure. The mechanisms involved in PM₁₀ mediated CV effects are unknown although changes in plasma viscosity and in the homoeostasis of blood coagulation have been implicated. It was hypothesised that PM₁₀ exposure would result in an inflammatory response and enhance the activation of the extrinsic coagulation mechanisms in pulmonary and vascular cells in culture.     

Reducing knee and anterior cruciate ligament injuries among female athletes: a systematic review of neuromuscular training interventions

There is evidence that neuromuscular training not only decreases the potential biomechanical risk factors for ACL injury, but also decreases knee and, specifically, ACL injury incidence in female athletes. Five of the six interventions in this systematic review demonstrated significant effects on overall knee or ACL injury rates. It appears that plyometric power, biomechanics and technique, strength, balance, and core stability training can induce neuromuscular changes and potential injury prevention effects in female athletes. However, it is unknown which of these components is most effective or whether the effects are combinatorial. Future research should assess the relative efficacy of these interventions alone and in combination to achieve the optimal effect in the most efficient manner possible. Selective combination of neuromuscular training components may provide additive effects, further reducing the risk of ACL injuries in female athletes. Additional research directions include the assessment of relative injury risk using mass neuromuscular screening, the development of more specific injury prevention protocols targeted toward high-risk athletes, and the determination of when these interventions should be implemented. It may be that prepubertal or early pubertal female athletes may have the potential to achieve optimal biomechanical changes and the greatest chance of injury-free sports participation throughout their careers.     

Hypertensive disorders in pregnancy: a population-based study

OBJECTIVES: To determine population-based rates and outcomes of hypertensive disorders in pregnancy. DESIGN: Cross-sectional study using linked population databases. SETTING AND PARTICIPANTS: All women, and their babies, discharged from hospital following birth in New South Wales, between 1 January 2000 and 31 December 2002. MAIN OUTCOME MEASURES: Rates of hypertensive disorders in pregnancy, maternal and infant morbidity and mortality, and level of hospital care for the birth admission. RESULTS: 250 173 women and their 255 931 infants were included in the study. Overall, 24 517 women (9.8%) had a hypertensive disorder in pregnancy, including 1411 (0.6%) with chronic hypertension, 10 379 (4.2%) with pre-eclampsia, 731 (0.3%) with chronic hypertension with superimposed pre-eclampsia, and 10 864 (4.3%) with gestational hypertension. Women with, and infants exposed to, hypertension were more likely to suffer death or major morbidity than those without hypertension. Infants of mothers with hypertension were more likely to be to born preterm and small for gestational age. Just over half the women with major morbidity or mortality delivered in hospitals with a high level of medical care. In contrast, most infants with major morbidity or mortality were delivered in hospitals with neonatal intensive care units. CONCLUSIONS: Hypertension is a common complication of pregnancy, and adverse outcomes are increased among hypertensive women and their babies. Clinicians appear to be better at identifying and seeking an appropriate level of care for pregnancies where the infant is at risk of a poor outcome than when the mother is at risk. More specific antenatal indicators of poor maternal outcome would help guide the referral of hypertensive women to higher levels of care.     

Association between phonocardiographic third and fourth heart sounds and objective measures of left ventricular function

Context  The third (S₃) and fourth (S₄) heart sounds detected by phonocardiography are considered to represent the criterion standards of the gallop sounds, but their test characteristics have not been explored. Objective  To determine the diagnostic test characteristics of the S₃ and S₄ for prediction of left ventricular dysfunction using a computerized heart sound detection algorithm. Design, Setting, and Participants  Prospective study of 90 adult patients undergoing elective left-sided heart catheterization at a single US teaching hospital between August 2003 and June 2004. The mean age was 62 (SD, 13) years (range, 24-90 years) and 61 (68%) were male. Within a 4-hour period, participants underwent computerized heart sound phonocardiographic analysis, cardiac catheterization, transthoracic echocardiography, and blood sampling for assessment of an S₃/S₄, left ventricular end-diastolic pressure (LVEDP), left ventricular ejection fraction (LVEF), and B-type natriuretic peptide (BNP), respectively. Main Outcome Measures  Diagnostic test characteristics of the computerized phonocardiographic S₃ and S₄ using markers of left ventricular function as criterion standards. Results  Mean (SD) LVEDP was significantly elevated (18.4 [6.9] mm Hg vs 12.1 [7.3] mm Hg; P<.001), mean (SD) LVEF was reduced (49.4% [20.2%] vs 63.6% [14.8%]; P<.001), and median (interquartile range) BNP was elevated (330 [98-1155] pg/mL vs 86 [41-192] pg/mL; P<.001) in those with an S₃, S₄, or both compared with patients without a diastolic heart sound. The sensitivities of these heart sounds to detect an elevated LVEDP, reduced LVEF, or elevated BNP were 41%, 52%, and 32% for an S₃, and 46%, 43%, and 40% for an S₄, respectively. For abnormal levels of the same markers of ventricular function, the specificities of the S₃ were 92%, 87%, and 92%, while the specificities of the S₄ were 80%, 72%, and 78%, respectively. Conclusions  Neither the phonocardiographic S₃ nor the S₄ is a sensitive marker of left ventricular dysfunction. The phonocardiographic S₃ is specific for left ventricular dysfunction and appears to be superior to the moderate specificity of the phonocardiographic S₄.      

Longitudinal tear of the tibialis anterior tendon

Diagnosis and treatment of longitudinal tears of the tibialis anterior tendon are not well documented in the surgical literature. Described here is successful primary surgical repair of a longitudinally torn tibialis anterior tendon in a 60-year-old woman.     

Breakfast habits, nutritional status, body weight, and academic performance in children and adolescents

Breakfast has been labeled the most important meal of the day, but are there data to support this claim? We summarized the results of 47 studies examining the association of breakfast consumption with nutritional adequacy (nine studies), body weight (16 studies), and academic performance (22 studies) in children and adolescents. Breakfast skipping is highly prevalent in the United States and Europe (10% to 30%), depending on age group, population, and definition. Although the quality of breakfast was variable within and between studies, children who reported eating breakfast on a consistent basis tended to have superior nutritional profiles than their breakfast-skipping peers. Breakfast eaters generally consumed more daily calories yet were less likely to be overweight, although not all studies associated breakfast skipping with overweight. Evidence suggests that breakfast consumption may improve cognitive function related to memory, test grades, and school attendance. Breakfast as part of a healthful diet and lifestyle can positively impact children's health and well-being. Parents should be encouraged to provide breakfast for their children or explore the availability of a school breakfast program. We advocate consumption of a healthful breakfast on a daily basis consisting of a variety of foods, especially high-fiber and nutrient-rich whole grains, fruits, and dairy products.