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Objective

We tested the hypothesis that chronic fetal hypoxia, at a severity present in many types of congenital heart disease, would lead to abnormal neurodevelopment.

Methods

Eight mid-gestation fetal sheep were cannulated onto a pumpless extracorporeal oxygenator via the umbilical vessels and supported in a fluid-filled environment for 22 ± 2 days under normoxic or hypoxic conditions. Total parenteral nutrition was provided. Control fetuses (n = 7) were harvested at gestational age 133 ± 4 days. At necropsy, brains were fixed for histopathology. Neurons were quantified in white matter tracts, and the thickness of the external granular layer of the cerebellum was measured to assess neuronal migration. Capillary density and myelination were quantified in white matter. Data were analyzed with unpaired Student t tests or 1-way analysis of variance, as appropriate.

Results

Oxygen delivery was reduced in hypoxic fetuses (15.6 ± 1.8 mL/kg/min vs 24.3 ± 2.3 mL/kg/min, P < .01), but umbilical blood flow and caloric delivery were not different between the 2 groups. Compared with normoxic and control animals, hypoxic fetuses had reduced neuronal density and increased external granular layer thickness. Compared with normoxic and control animals, hypoxic fetuses had increased capillary density in white matter. Cortical myelin integrity score was lower in the hypoxic group compared with normoxic and control animals. There was a significant negative correlation between myelin integrity and capillary density.

Conclusions

Chronic fetal hypoxia leads to white matter hyper-vascularity, decreased neuronal density, and impaired myelination, similar to the neuropathologic findings observed in children with congenital heart disease. These findings support the hypothesis that fetal hypoxia, even in the setting of normal caloric delivery, impairs neurodevelopment.  相似文献   
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OBJECTIVES: Peripheral arterial disease (PAD) is associated with significant cardiovascular morbidity and mortality. The study objectives were to examine the prevalence of PAD and associated risk factors. DESIGN: A cross-sectional nationally representative health examination survey. SETTING: The National Health and Nutrition Examination Survey 1999-2004. PARTICIPANTS: Data from 3,947 men and women aged 60 and older who received a lower extremity examination. MEASUREMENTS: The main outcome was PAD, defined as an ankle-brachial blood pressure index of less than 0.9 in either leg. RESULTS: In older U.S. adults, PAD prevalence was 12.2% (95% confidence interval (CI) = 10.9-13.5%). PAD prevalence increased with age. PAD prevalence was 7.0% (95% CI = 5.6-8.4%) for those aged 60 to 69, 12.5% (95% CI = 10.4-14.6%), and 23.2% (95% CI = 19.8-26.7%) for those aged 70 to 79 and 80 and older. Age-adjusted estimates show that non-Hispanic black men and women and Mexican-American women had a higher prevalence of PAD than non-Hispanic white men and women (19.2%, 95% CI = 13.7-24.6%; 19.3%, 95% CI = 13.3-25.2%; and 15.6%, 95% CI = 12.7-18.6%, respectively). The results of the fully adjusted model show that current smoking (OR = 5.48, 95% CI = 3.60-8.35), previous smoking (OR = 1.94, 95% CI = 1.39-2.69), diabetes mellitus (OR = 1.81, 95% CI = 1.12-2.91), low kidney function (OR = 2.69, 95% CI = 1.58-4.56), mildly decreased kidney function (OR = 1.71, 95% CI = 1.22-2.38), high-sensitivity C-reactive protein greater than 3.0 mg/L (OR = 2.69, 95% CI = 1.24-5.85), treated but not controlled hypertension (OR = 1.95, 95% CI = 1.40-2.72), and untreated hypertension (OR = 1.68, 95% CI = 1.13-2.50) were all significantly associated with prevalent PAD. CONCLUSION: PAD prevalence increases with age and is associated with treatable risk factors for cardiovascular disease.  相似文献   
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