Biomedical subjects

A Lines

Publications and source records attributed to A Lines.

3 recordsLinked to original sources

PubMed1999

Alterations in lung expansion affect surfactant protein A, B, and C mRNA levels in fetal sheep.

Obstruction of the fetal trachea is a potent stimulus for fetal lung growth, and it has been suggested that this procedure may be used therapeutically to reverse lung growth deficits in human fetuses with lung hypoplasia. However, little is known about the effects of increased lung expansion on other aspects of lung development. Our aim was to determine the effect of increased and decreased lung expansion on the mRNA levels encoding surfactant protein (SP) A, SP-B, and SP-C in ovine fetal lungs. Lung tissue samples were collected from fetuses exposed to 2, 4, or 10 days of increased lung expansion caused by tracheal obstruction. The mRNA levels for SP-A, SP-B, and SP-C were determined by Northern blot analysis with specific ovine cDNA probes; SP-A protein levels were determined by Western blot analysis. Compared with age-matched (128-day gestational age) control fetuses, SP-A, SP-B, and SP-C mRNA levels in fetal lung tissue were significantly reduced at 2 days of tracheal obstruction and remained reduced at 4 and 10 days. However, SP-A protein levels were not reduced at 2 days of tracheal obstruction, tended to be reduced at 4 days, and were almost undetectable at 10 days. In contrast to tracheal obstruction, 7 days of lung liquid drainage significantly increased SP-C, but not SP-A, mRNA levels in fetal lung tissue compared with age-matched control fetuses. Our results demonstrate that increases in fetal lung expansion, induced by obstruction of the fetal trachea, cause large simultaneous reductions in SP-A, SP-B, and SP-C mRNA levels in the fetal lung as well as a decrease in SP-A protein levels. These data suggest that expression of the genes encoding SPs in the fetal lung are specifically responsive to the degree of lung expansion.

Animals↗

PubMed1997

Lung liquid production rates and volumes do not decrease before labor in healthy fetal sheep.

Previous studies have suggested that the volume and production rate of fetal lung liquid decrease late in gestation, before the onset of labor, in preparation for the clearance of lung liquid at birth. In contrast, our earlier studies have not shown a decrease in lung liquid volume near term, although these studies were not continued to the onset of labor. Our aim was to determine the changes in lung liquid volume and production rate in fetal sheep during the last 2 wk of gestation up to the onset of labor at term (approximately 147 days). In eight chronically catheterized fetal sheep, the volume and production rate of fetal lung liquid were measured at 130, 135, and 140 days of gestation and then on every 2nd day until the onset of labor. Labor was detected by monitoring uterine muscle activity and intrauterine pressure changes. On the day of labor onset, which occurred at 147 +/- 1 days of gestation, fetuses weighted 5.0 +/- 0.2 kg. The volume of fetal lung liquid was 40.4 +/- 2.7 ml/kg at 19 +/- 1 days before labor onset and had not significantly changed by 0.7 +/- 0.2 days (44.8 +/- 5.1 ml/kg) before labor. Similarly, lung liquid production rates at 19 +/- 1 days before labor (5.1 +/- 1.8 ml.h-1.kg-1) were not significantly different from those at 0.7 +/- 0.2 days before labor (3.4 +/- 0.7 ml.h-1.kg-1). We conclude that, in healthy ovine fetuses, lung liquid volumes and production rates do not decrease before the onset of labor. Our results indicate that the entire volume of fetal lung liquid (approximately 222.5 +/- 36.6 ml) must be cleared after the onset of labor.

Animals↗

PubMed1993

Self-management of osteoarthritis.

Osteoarthritis is the most prevalent activity-limiting condition among older persons. In addition to, or instead of, taking nonsteroidal anti-inflammatory drugs, people use a variety of activities to manage their osteoarthritis. This study describes the self-management methods reported by 61 participants aged 60 years or older assessed on two occasions 8 months apart. A questionnaire was developed to assess levels of use of 10 self-management methods including low-impact activity, rest, range-of-motion exercises, relaxation, heat (or cold), taking medication, joint protection, massage, splints, and any other activity. On a typical day, participants used about four of these activities to manage osteoarthritis symptoms, and significantly more on a day that their arthritis was worse than usual. Three self-management scales were formed from groups of activities suggested by factor analysis (medication taking, typical management, and worse-day passive management) that demonstrated adequate internal consistency and stability across the two assessments. The findings are discussed in terms of the importance of developing a brief measure of osteoarthritis self-management, and the substantial individual variation in subsets of methods used.

Activities of Daily Living↗