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991.

Background  

Several transitions that a woman experiences prenatally may influence her desire or ability to discontinue smoking. This study explores the role of smoking for young, Appalachian, nulliparous pregnant women and their plans for smoking during their pregnancies.  相似文献   
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Harris GD 《Primary care》2000,27(3):767-84;vii-viii
Advances in the understanding of the pathophysiology, diagnosis, and medical and surgical management of neonates with cardiovascular disease has led to their improved survival rates. These improvements have resulted in an increased number of pediatric patients presenting to the primary care physician's office with underlying heart disease. Understanding the genetic, congenital, or acquired etiologies to the various pediatric heart diseases is crucial to preventing these lesions and treating these patients.  相似文献   
994.
OBJECTIVE: To evaluate the use of GHb as a screening test for undiagnosed diabetes (fasting plasma glucose > or =7.0 mmol/l) in a representative sample of the U.S. population. RESEARCH DESIGN AND METHODS: The Third National Health and Nutrition Examination Survey included national samples of non-Hispanic whites, non-Hispanic blacks, and Mexican Americans aged > or =20 years. Of these subjects, 7,832 participated in a morning examination session, of which 1,273 were excluded because of a previous diagnosis of diabetes, missing data, or fasting time of <8 h before examination. Venous blood was obtained to measure fasting plasma glucose and GHb in the remaining 6,559 subjects. Receiver operating characteristic curve analysis was used to examine the sensitivity and specificity of GHb for detecting diabetes at increasing GHb cutoff levels. RESULTS: GHb demonstrated high sensitivity (83.4%) and specificity (84.4%) for detecting undiagnosed diabetes at a GHb cutoff of 1 SD above the normal mean. Moderate sensitivity (63.2%) and very high specificity (97.4%) were evident at a GHb cutoff of 2 SD above the normal mean. Sensitivity at this level ranged from 58.6% in the non-Hispanic white population to 83.6% in the Mexican-American population; specificity ranged from 93.0% in the nonHispanic black population to 98.3% in the non-Hispanic white population. CONCLUSIONS: GHb is a highly specific and convenient alternative to fasting plasma glucose for diabetes screening. A GHb value of 2 SD above the normal mean could identify a high proportion of individuals with undiagnosed diabetes who are at risk for developing diabetes complications.  相似文献   
995.
Multichannel tetrode array recording in awake behaving animals provides a powerful method to record the activity of large numbers of neurons. The power of this method could be extended if further information concerning the intracellular state of the neurons could be extracted from the extracellularly recorded signals. Toward this end, we have simultaneously recorded intracellular and extracellular signals from hippocampal CA1 pyramidal cells and interneurons in the anesthetized rat. We found that several intracellular parameters can be deduced from extracellular spike waveforms. The width of the intracellular action potential is defined precisely by distinct points on the extracellular spike. Amplitude changes of the intracellular action potential are reflected by changes in the amplitude of the initial negative phase of the extracellular spike, and these amplitude changes are dependent on the state of the network. In addition, intracellular recordings from dendrites with simultaneous extracellular recordings from the soma indicate that, on average, action potentials are initiated in the perisomatic region and propagate to the dendrites at 1.68 m/s. Finally we determined that a tetrode in hippocampal area CA1 theoretically should be able to record electrical signals from approximately 1, 000 neurons. Of these, 60-100 neurons should generate spikes of sufficient amplitude to be detectable from the noise and to allow for their separation using current spatial clustering methods. This theoretical maximum is in contrast to the approximately six units that are usually detected per tetrode. From this, we conclude that a large percentage of hippocampal CA1 pyramidal cells are silent in any given behavioral condition.  相似文献   
996.
OBJECTIVE: Low muscle strength is associated with poorer physical function, but limited empirical evidence is available to prove the relationship between muscle mass and physical function. We tested the hypothesis that persons with lower muscle mass or muscle strength have poorer lower-extremity performance (LEP). DESIGN: A cross-sectional, population-based study. PARTICIPANTS: A cohort of 449 men and women aged 65 years and older living in Amsterdam and its surroundings participating in the second examination (1995-1996) of the Longitudinal Aging Study Amsterdam. MEASUREMENTS: Leg skeletal muscle mass was measured using dual-energy X-ray absorptiometry (DXA). Grip strength was used as an indicator of muscle strength. Timed functional performance tests, including walking and repeated chair stands, were used to assess LEP. RESULTS: After adjustment for body height and age, leg muscle mass was positively associated with LEP in men (regression coefficient 0.178 [95% confidence interval 0.013-0.343], P = .035). In women an inverse association was observed, which became positive after additional adjustment for body mass index (BMI) (0.202 [-0.001-0.405], P = .052). Grip strength was positively associated with LEP in men and women. After additional adjustment for behavioral, physiological, and psychological variables, the associations between leg muscle mass and LEP disappeared, whereas grip strength remained to be independently associated with LEP in men (0.079 [0.042-0.116], P = .0001), with a tendency in women (0.046 [-0.009-0.101], P = .11). Results were similar when quartiles of leg muscle mass or grip strength were used. CONCLUSIONS: These results suggest that low muscle strength, but not low muscle mass, is associated with poor physical function in older men and women. However, prospective studies are needed to investigate the association between loss of muscle mass and physical function.  相似文献   
997.
Sixty nine patients with meningococcal disease some of whom presented with a maculopapular rash were entered in a prospective multicentre study. The clinical and laboratory features of children presenting with maculopapular rashes were compared with those of children presenting with typical haemorrhagic rashes. Of the 69 children 26 (38%) developed maculopapular rashes; nine (13%) had a maculopapular rash only, and the remaining 17 had a mixed maculopapular-purpuric rash. Twelve of the 17 (7%) had less than 12 petechiae. Children with maculopapular rashes had significantly higher platelet counts (median 294 compared with 243 x 10(9)/l), and plasma total haemolytic complement activity (80.5 compared with 65.0 U/ml) and significantly lower Glasgow meningococcal septicaemia prognostic scores (2.5 compared with 5.5) than those with purpuric rashes on admission. There were no significant differences between the groups in mortality, white cell count or absolute neutrophil count on admission, or C reactive protein concentration. Meningococcal disease can present with a maculopapular rash alone but this does not necessarily mean that the disease is less severe.  相似文献   
998.
The transoropalatal approach to the atlantoaxial-clival area provides excellent exposure for neurosurgical decompression and fusion procedures. The technique has been effectively applied in the treatment of bony and soft tissue abnormalities of the anterior spinal region. Although this approach is safe and reliable, it is not part of the otolaryngologist's usual surgical armamentarium. In the present study, we describe the case histories of five patients who underwent resection of the odontoid process for cervicomedullary compression. Neurological compromise was manifested by progressive upper and/or lower extremity paresis in all patients. In each patient, a transoropalatal approach was used. The surgical technique is discussed, and the prevention of possible sequelae, including velopharyngeal incompetence and palatal or pharyngeal wound dehiscence, is addressed.  相似文献   
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