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1.
We assessed the mechanics and morphology of the lung in 165 rats treated neonatally with either room air (RA), O2, RA + steroids, or O2, + steroids. Newborn Sprague-Dawley male rats were randomly assigned to these groups. O2,-exposure (0.96-1.0 FiO2 lasted 5 days, and dexamethasone treatment consisted of eight daily S.C. injections of drug or buffer in successive doses of 0.5,0.4.0.3,0.2,0.1, 0.1. 0.1. and 0.1 mg/kg. At 58 days, right ventricular systolic pressure (RVP) was measured. At 60 days, all rats were sacrificed for obtaining lung weight and DNA, saline pressure-volume (P-V) curves, and morphometry. We weighed right ventricles (RV) and left ventricles + septa (LV). Hyperoxia alone did not, but steroid decreased survival rate to 79.4% (95.3% in RA rats, P < 0.02). Only 21 of 40 (52%) O2 + steroids rats survived, less than in both RA groups (P < 0.001). RV weight, RVP and muscularization of alveolar duct arteries were significantly increased in O2 vs. RA rats. In RA + steroids rats, weight of the LV was decreased but RV, RVP, and lung vasculature were not affected. These effects were additive in the O2 + steroid group. Wet lung weights and DNA were increased for RA + steroid rats over all others. O2 and steroids shifted the P-V curve to the left and O2+ steroids still further. Maximal lung volume increased significantly with RA + steroids and still further in O2 + steroids but not in O2 alone. O2 and steroids significantly increased the mean linear intercept and O2 + steroids even more so. In O2- and steroid-treated rats, the parenchymal air space increased. In conclusion, both neonatal hyperoxia and steroid administration caused aberrations in the growth of lung and connective tissue. The effects of the two were additive. The vascular system, maximal lung volume, and DNA responded differently, presumably by different modes of action. Pediatr Pulmonol. 1993; 16:81–88. © 1993 Wiley-Liss, Inc. 相似文献
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V Allen PhD DW Ryan MB FRCA A Murray PhD FIPSM 《International journal of clinical practice》1994,48(3):125-129
SUMMARY Four specialised air mattresses had interface pressure measured under six body sites prone to pressure sores in 10 subjects, supine and sitting. The mattresses were the Clinirest (SSI) and FirstStep (KCI) continuous airflow mattress overlays, and Airwave (Pegasus) and Nimbus (Huntleigh) alternating pressure air mattresses. On the mattress overlays, average supine interface pressures were 2.33 kPa (scapula), 4.15 kPa (elbow), 1.94 kPa (sacrum) and 2.79 kPa (buttock), although they were higher at the occiput (7.97 kPa) and heel (11.7 kPa). The alternating pressure air mattresses had an average minimum interface pressure close to zero for three sites, rising to 4.28 kPa under the heel. Average maximum interface pressures were 8.61 kPa (occiput), 5.21 kPa (scapula), 4.90 (elbow), 4.85 kPa (sacrum), 4.61 kPa (buttock) and 13.2 kPa (heel). No accepted scientific method exists for comparing the two types of mattress. Our data suggest a clinical benefit at the occiput and heel (supine) in using an alternating pressure air mattress and a benefit in using a continuous airflow mattress overlay at other sites. 相似文献
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Eleven radiologists appointed by the major radiological societies participated for the past 5 years in the development of the Health Policy Agenda for the American People. The Agenda is an action plan to address a wide variety of serious problems in medicine. The first phase involved establishment of 159 principles, broad value statements that were the foundation of the project. Phase 2 involved the development of policy proposals on 38 urgent issues for action in medical science; education; health resources; delivery mechanisms; evaluation, assessment, and control; and payment for services. These proposals are summarized in this report. The activities and recommendations of representatives for the field of radiology are described. The Agenda has been released, and an implementation phase has begun. It will likely be of great importance to the practice of radiology over the next decade. Important issues can be addressed by acting with the coalitions that are being formed from among the more than 150 participating organizations. 相似文献
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Hart TC; Bowden DW; Bolyard J; Kula K; Hall K; Wright JT 《Human molecular genetics》1997,6(13):2279-2284
Tricho-dento-osseous syndrome (TDO), MIM# 190320, is transmitted as a
highly penetrant autosomal dominant trait that is characterized by variable
clinical expression. The principal clinical features include kinky/curly
hair in infancy, enamel hypoplasia, taurodontism, as well as increased
thickness and density of cranial bones. Possible genetic linkage has been
reported for TDO with the ABO blood group locus, but the gene defect
remains unknown. We have identified four multiplex families (n = 63, 39
affected, 24 unaffected) from North Carolina segregating TDO. We previously
have excluded a major locus for TDO in the ABO region for these families.
Utilizing a genome-wide search strategy, we obtained conclusive evidence
for linkage of the TDO syndrome locus to markers on chromosome 17q21
(D17S791, Z max = 10.54, Theta = 0.00) with no indication of genetic
heterogeneity. Multipoint analysis suggests the TDO locus is located in a 7
cM chromosomal segment flanked by D17S932 and D17S941. This finding
represents the first step towards isolation and cloning of the TDO gene.
Identification of this gene has important implications for understanding
normal and abnormal craniofacial development of hair, teeth and bone.
相似文献