American journal of respiratory and critical care medicine
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Am. J. Respir. Crit. Care Med. · May 2000
The prone position eliminates compression of the lungs by the heart.
The prone position improves gas exchange in many patients with ARDS. Animal studies have indicated that turning prone restores ventilation to dorsal lung regions without markedly compromising ventral regions. To investigate a potential mechanism by which this might occur, the relative volume of lung located directly under the heart was measured in the supine and prone positions in seven patients. ⋯ When supine, the percent of the total lung volume located under the heart increased from 7 +/- 4% to 42 +/- 8%, and from 11 +/- 4% to 16 +/- 4% in Sections 1 through 4, in the left and right lungs, respectively. When prone, the percent of left and right lung volume located under the heart was
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Am. J. Respir. Crit. Care Med. · May 2000
Polymorphisms of the IL-4, TNF-alpha, and Fcepsilon RIbeta genes and the risk of allergic disorders in at-risk infants.
Polymorphisms in the TNF-alpha (A-308G), IL-4 (C-589T), and Fcalpha RIbeta (E237G) genes have been associated with asthma and related phenotypes. To determine the predictive value of these polymorphisms we have assessed their relative risk (RR) for the development of atopy, asthma, and rhinitis in a high-risk infant population that is being followed longitudinally from birth. DNA was extracted and genotyped for 373 infants and 572 parents for each polymorphism. ⋯ However, we found that the IL4-589*T allele was associated with "probable" asthma (RR = 4.1) and that homozygotes for the IL4-589*T allele had an increased risk for the development of rhinitis (RR = 2.4). Using the transmission disequilibrium test, an association of IL4-589*T with atopy was found. We conclude that IL-4-589*T, but not TNF-alpha-308*2 or Fcalpha RIbeta*G, is a risk factor for the development of atopy, asthma, and rhinitis by 12 mo of age.
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Am. J. Respir. Crit. Care Med. · May 2000
Antituberculosis activity of once-weekly rifapentine-containing regimens in mice. Long-term effectiveness with 6- and 8-month treatment regimens.
The effectiveness of various once-weekly 10 mg/kg rifapentine (P)- containing regimens for treatment of tuberculosis was assessed in mice infected intravenously with 4.3 x 10(6) colony-forming units (cfu) of Mycobacterium tuberculosis H37Rv, and treated 14 d later with various combinations of rifampin (R), P, isoniazid (H), pyrazinamide (Z), ethambutol (E), or streptomycin (S). Control mice treated daily with either 2-mo HRZ + 4-mo HR or 2-mo HRZ + 6-mo HE were rendered spleen and lung culture-negative at 6 mo and 8 mo, respectively. ⋯ When the initial daily phase was reduced to 2 wk, once-weekly PH-containing treatment was successful, at 6 mo, only if it was supplemented with S during the initial daily and the once-weekly phases, and at 8 mo if it was supplemented with daily H during the once-weekly phase. Without these supplements, once-weekly treatment failed in some mice with selection of R-resistant or H-resistant mutants.