Biomedical subjects

G A Emerson

Publications and source records attributed to G A Emerson.

10 recordsLinked to original sources

PubMed1998

Effects of ventilation style on surfactant metabolism and treatment response in preterm lambs.

We investigated whether the style of ventilation would influence respiratory physiology or surfactant metabolism in surfactant-treated preterm lambs. Preterm lambs were delivered at 131 +/- 1 d gestation and treated with an organic solvent extract of sheep surfactant (100 mg/kg). The lambs were randomized to ventilation peiods of 2 h, 5 h, 10 h, or 24 h, and to ventilation with a low rate (15 breaths/min) and high VT (15 ml/kg), with a high rate (50 breaths/min) and low VT (8 ml/kg), or with high-frequency oscillatory ventilation (HFOV). Gas exchange and lung volumes were similar across time and for the different ventilation styles. Saturated phosphatidylcholine (SatPC) in alveolar lavage was lower for the HFOV group than for the other ventilation groups at 10 h and 24 h. The rate of loss of surfactant protein B (SP-B) from these preterm animals' lungs was slow and not influenced by ventilation style. The percentages of surfactants in large-aggregate forms were not changed by style of ventilation, and the large-aggregate surfactants had excellent function when tested in surfactant-deficient preterm rabbits. Alveolar lavage protein was low (30 ml/kg), and tissue hyaluronan did not change with time or ventilation style. In preterm lambs ventilated without causing injury, the extreme styles of ventilation examined in the study had minimal effects on lung function, surfactant function, or surfactant metabolism.

Animals↗

PubMed1997

Intra-amniotic interleukin-1 alpha treatment alters postnatal adaptation in premature lambs.

We measured the physiological and biochemical responses of preterm lambs to intra-amniotic injection of interleukin-1 alpha (IL-1 alpha). Singleton lamb fetuses at 126 days of gestation were randomized to receive 125 micrograms IL-1 alpha or vehicle control via ultrasound-guided intra-amniotic injection. Each lamb was delivered 48 h later by caesarian section and ventilated for 120 min. Relative to controls, IL-1 alpha-treated lambs had higher dynamic compliance, ventilatory efficiency indices, and saturated phosphatidylcholine levels (all p < 0.05). Umbilical cord plasma cortisol and catecholamine levels, white blood cells and differentials, cardiac output, regional blood flow, and kidney function did not differ between the groups. However, at 120 min after delivery, the cortisol levels for IL-1 alpha-treated animal were higher than for controls. Single intra-amniotic IL-1 alpha treatment increases surfactant pool size and improves dynamic compliance in the absence of an inflammatory response or differences in other indicators of fetal or newborn organ function.

Adaptation, Physiological↗

PubMed1979

Effect of diethylcarbamazine citrate on fourth stage and adult Brugia malayi in cats.

Sixty-three experimental and 58 control cats were infected with Brugia malayi so that the developing and adult worms localized in the regional lymphatics of the hind legs. At 20 days after infection when Brugia were in the 4th larval stage, and at 8 weeks when worms were young adults, cats were divided into groups to test the efficacy of diethylcarbamazine citrate (DEC) at various dosage levels. At 100 mg total DEC/kg no 4th-stage larvae were seen in 5 cats compared with a mean of 20.4 living larvae in each of 5 controls. At this level of DEC, 2 of 5 cats had 1 and 2 adult worms while 4 of 4 controls had a mean of 23.2 living adult worms. At 50 and 25 mg/kg there was a substantial reduction of both 4th stage and adult worms when compared to controls. At 10 mg/kg, 4 of 6 cats had 4th-stage larvae but at a lower level (mean = 7.0) than in 6 controls (mean = 23.2). No reduction of either 4th-stage larvae or adult worms was seen at 1 mg/kg. This study establishes the efficacy of DEC against 4th-stage and adult Brugia malayi in cats, although considerably higher levels of the drug were required than the level previously determined to kill 3rd-stage larvae. It appears that the cat-B. malayi model will be an effective method to compare the efficacy of drugs against adult lymphatic-dwelling filariae.

Animals↗

PubMed1977

Agnes Fay Morgan and early nutrition discoveries in California.

Agnes Fay Morgan (1884-1968) and several other California pioneers in nutrition contributed much to the early increase in basic knowledge of nutrition and foods. Dr. Morgan became a member of the faculty in the division of Nutrition at the University of California at Berkeley in 1915. Her academic retirement was in 1954, but she remained active and productive even to the time of her death in 1968. The hallmark of her career was the high standards she established both in training home economists and nutrition investigators and in gaining widespread public recognition of the importance of good nutrition. Also,, she was imaginative and productive in significant research. Such work was directed to the nutrients of California foods and the effects on food values resulting from heat processing and storage. Other major early nutrition scientists in California included Ruth Okey, H. M. Evans, H. S. Olcott, S. Lepkovsky, H. J. Almquist, T. H. Jukes, and E. L. R. Stokstad. Their contributions included major accomplishments in the discovery and/or characterization of vitamin E, vitamin B6, pantothenic acid, and vitamin K.

California↗

PubMed1975

Effect of diethylcarbamazine on third stage Brugia malayi larvae in cats.

Forty-one experimental and 37 control cats were each infected with 50 Brugia malayi larvae in such a way that a preponderance of the larvae remained localized in the popliteal lymph node or in the lymphatics of the leg draining into that node. During the 1st week after infection cats were treated with varying doses of diethylcarbamazine citrate (DEC). Two weeks after infection, necropsy for worm recovery was performed on treated and control cats. No living larva was recovered from 21 of 22 cats treated with a total of 10 mg DEC/kg body weight or greater. A single living larva was recovered in only 2 of 5 cats treated at 5 mg/kg. At 2 mg/kg, 8 of 10 cats had substantially fewer larvae than their controls; the remaining 2 were negative. In 4 cats treated with a total of 1 mg/kg, there was no reduction of larvae. All 37 untreated controls harbored living larvae, with a mean of 56% of the inoculum being recovered.

Brugia↗

PubMed1973