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1.
The Physical Inactivity Matrix: Lessons from the classification of physical inactivity interventions
Kypros Kypri Alex Donaldson Elizabeth Johnstone 《Journal of Science and Medicine in Sport》2006,9(1-2):98-102
Physical inactivity (PI), a leading modifiable cause of disease and injury, is endemic in industrialised nations. Although considerable research has been undertaken in this field, we lack a system to synthesise the research literature to inform policy and identify research needs. The aims of this study were to (1) develop a system to classify physical inactivity intervention studies, (2) examine the distribution of PI interventions published in the peer-reviewed health literature using the system, and (3) consider implications for future research. We developed the Physical Inactivity Matrix (PIM), with 12 intervention points, created by the intersection of two dimensions: the intervention target (individual, physical environment and social/cultural environment) and the activity focus (transport, work/school, leisure and consumer). A formal search of the health research literature identified 529 eligible studies and each was classified into one of the 12 cells of the PIM. Most studies were categorised as: individual-leisure (68%), individual-work/school (12%) or social/cultural environment-leisure (13%). Only 4% targeted the physical environment. The findings of this initial application of the PIM support the call for greater investment in policies, interventions and research that focus on the relationship between the environment and PI, and transportation in particular. There would be merit in establishing the inter-rater reliability of the PIM and applying it to a wider variety of studies, including those published in the transportation and urban planning literatures. The PIM could be a useful tool for monitoring trends in research directions and funding levels over time and across countries. 相似文献
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Hyett Jon; Moscoso Gonzalo; Nicolaides Kypros 《Human reproduction (Oxford, England)》1995,10(11):3045-3048
Pathological examination of the heart and great vessels wasperformed in 61 specimens obtained after surgical terminationof pregnancy for psychosocial indications at 918 weeksof gestation. The aorta and pulmonary trunk were identifiedand external diameters were measured at the level of, and distalto the aortic valve and pulmonary valve, the level of the aorticisthmus and thoracic aorta, and the proximal and distal ductusarteriosus. All eight vessel diameters increased linearly withgestational age and the ratio of the diameter of the aorticisthmus to that of the aortic valve or the distal ductus arteriosusalso increased with gestation. Early pregnancy is characterizedby rapid growth of the fetal head and this may well be the consequenceof a preferential distribution of left ventricular output infavour of the head due to relative narrowing of the aortic isthmusat this gestation. 相似文献
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Jauniaux Eric; Gavrill Panagiotis; Khun Peter; Kurdi Wesam; Hyett Jon; Nicolaides Kypros H. 《Human reproduction (Oxford, England)》1996,11(2):435-439
Fetal heart rate, umbilical artery pulsatility index, end-diastolicflow,nuchal translucency thickness and placental thickness were recordedin 250 women with a viable singleton pregnancy undergoing chorionicvillous sampling for fetal karyotyping at 11–14 weeksof gestation. The fetal karyotype was normal in 210 cases andabnormal in 40, including 21 with trisomy 21, 13 with trisomy18, three with triploidy, two with monosomy X and one with trisomy13. A total of 52 fetuses with a normal karyotype had a nuchaltranslucency 3 mm and were considered separately. There wasa stable and significant increase in the mean fetal heart ratein trisomy 21 pregnancies compared to controls. No significantdifference was found for the other variables between the groups.In chromosomally normal fetuses with an increased nuchal thickness,the development of fetal heart rate and compliance of the umbilico-placentalcirculation were within the normal ranges. Some fetuses withtrisomy 18 or triploidy had an increased resistance to bloodflow in the umbilical artery, which was probably due to abnormalplacental development. 相似文献
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OBJECTIVE: To examine the distribution of first-trimester biochemical markers of aneuploidy in twin pregnancies, and to assess whether there are differences in the distributions between monochorionic and dichorionic twins. METHODS: Maternal serum-free beta-hCG and PAPP-A were measured between 11 + 0 and 13 + 6 weeks as part of a routine first-trimester screening program in conjunction with fetal nuchal translucency (NT) performed at two sites. Data from twin pregnancies were extracted from the fetal databases along with information on the chorionicty. The individual marker concentrations were expressed as weight corrected, ethnicity corrected, smoking corrected and IVF corrected MoM using data from singleton pregnancies as the reference. The overall medians were compared to those in singleton pregnancies and between monochorionic and dichorionic twins. RESULTS: Data was available from 1914 sets of twins. Of these, 1214 had information with respect to chorionicity, with 1024 being dichorionic and 190 being monochorionic. The overall median weight corrected, ethnicity corrected, smoking corrected and IVF corrected MoM amongst twin pregnancies were 2.023 for free beta-hCG (sd log(10) MoM = 0.2611 and 2.121 for PAPP-A (sd log(10) MoM = 0.2255) -- both medians were significantly greater than the medians in singleton pregnancies (1.00 MoM). In the case of monochorionic and dichorionic twins the median weight corrected, ethnicity corrected, smoking corrected and IVF corrected, free beta-hCG MoM's were not significantly different (1.983 v 2.041), however for PAPP-A the median weight corrected, ethnicity corrected, smoking corrected and IVF corrected MoM in monochorionic twins was significantly lower than in dichorionic twins (1.756 v 2.250) whilst the sd log(10) MoM's were not significantly different (0.2185 v 0.2167). CONCLUSION: Screening in twin pregnancies requires adjustment of the calculated MoM to account for the presence of two fetuses. In general, for free beta-hCG, this should be by dividing the observed corrected MoM by 2.023. For PAPP-A two different factors are required - 2.192 in dichorionic twins and 1.788 in monochorionic twins. 相似文献
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Smith GC Yu CK Papageorghiou AT Cacho AM Nicolaides KH;Fetal Medicine Foundation Second Trimester Screening Group 《Obstetrics and gynecology》2007,109(1):144-151
OBJECTIVE: We sought to relate the risk of antepartum stillbirth to uterine artery Doppler flow velocimetry at 22-24 weeks. METHODS: Data were available from 30,519 unselected women from seven units in the UK who had uterine artery Doppler performed between 22 and 24 weeks of gestation. The risk of stillbirth (n=109) was assessed using time to event and logistic regression analysis. Stillbirths were subdivided into placental (due to abruption, preeclampsia, or growth restriction) or unexplained. RESULTS: The risk of placental stillbirth was increased among women with a mean pulsatility index in the top decile (adjusted hazard ratio [HR] 5.5, 95% confidence interval [CI] 2.8-10.6) and those with a bilateral notch (adjusted HR 3.9, 95% CI 2.0-7.8). The relationship between a mean pulsatility index in the top decile and the risk of unexplained stillbirth was weaker (adjusted HR 2.5, 95% CI 1.1-5.6) and there was no association with a bilateral notch. Placental stillbirths occurred at earlier gestations than unexplained stillbirths (median [interquartile range] 30 [26-36] compared with 38 [36-40], P<.001). Consequently, being in the top 5% of predicted risk of stillbirth on the basis of the combination of mean pulsatility index and notching was a good predictor (sensitivity, specificity, and positive likelihood ratio) of all cause stillbirth up to 32 weeks (58%, 95%, and 12.1, respectively) but a poor predictor of stillbirth at later gestations (7%, 95%, and 1.3, respectively). CONCLUSION: Abnormal uterine artery Doppler was a better predictor of the risk of stillbirth due to placental causes than unexplained stillbirth. Consequently, abnormal uterine artery Doppler was a good predictor of stillbirth at extreme preterm gestations but a poor predictor of stillbirth at term. LEVEL OF EVIDENCE: II. 相似文献
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Banerjee S Smallwood A Moorhead J Chambers AE Papageorghiou A Campbell S Nicolaides K 《The Journal of clinical endocrinology and metabolism》2005,90(2):944-952
The inability of the mother to switch from T helper cell type 1 (Th1) to Th2 cytokine profiles at the fetal-maternal interface has been proposed as one of the primary causes of miscarriage, intrauterine growth restriction (IUGR), and preeclampsia (PE). The Th1 [interferon-gamma (IFN-gamma), TNF-alpha, and IL-12] and Th2 (IL-4 and IL-10) cytokines have opposite effects on human pregnancy. Leukemia inhibitory factor (LIF) promotes embryo implantation and sustains pregnancy, whereas IFN-gamma and TNF-alpha are detrimental to pregnancy. Both IFN-gamma and LIF are produced by maternal cells and tissues at the fetal-maternal interface, whereas the IFN-gamma receptors (IFN-gamma R1 and IFN-gamma R2) and LIF receptor are abundantly expressed on the surface of placental trophoblasts. The effect of IFN-gamma on T lymphocyte activation is influenced by the relative membrane density of its two receptors, particularly IFN-gamma R2. In this study we report that in PE (25-40 wk gestation) and PE complicated by IUGR, IFN-gamma R2 protein expression is severely down-regulated and is similar to that observed in early placenta (7-10 wk gestation) developing under low O(2) tension. IFN-gamma production was found to be inversely related to the IFN-gamma R2 protein expression, and LIF receptor protein expression in PE mimicked that in early placental development. These results show that in PE, placental trophoblasts fail to establish an early to late switch with respect to IFN-gamma and IFN-gamma R2 expression. This supports the hypothesis that trophoblasts control the polarization of maternal immune effectors and cytokine profiles at the fetal-maternal interface that could be subject to oxidative stress in PE. 相似文献
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