Biomedical subjects

A J Bartlett

Publications and source records attributed to A J Bartlett.

5 recordsLinked to original sources

PubMed1998

Effects of ventilation strategies on the efficacy of exogenous surfactant therapy in a rabbit model of acute lung injury.

We evaluated the effects of various ventilation strategies on the efficacy of exogenous surfactant therapy in lung-injured adult rabbits. Lung injury was induced by repetitive whole-lung saline lavage followed by mechanical ventilation. Three hours after the final lavage, 100 mg lipid/kg bovine lipid extract surfactant was instilled. After confirmation of similar responses to exogenous surfactant, animals were then randomized to one of four ventilation groups; (1) Normal tidal volume (VT) (5 cm H2O): VT = 10 ml/kg, respiratory rate (RR) = 30/min, positive end-expiratory pressure (PEEP) = 5 cm H2O; (2) Normal VT (9 cm H2O): VT = 10 ml/kg, RR = 30/min, PEEP = 9 cm H2O; (3) Low VT (5 cm H2O): VT = 5 ml/kg, RR = 60/min, PEEP = 5 cm H2O; (4) Low VT (9 cm H2O): VT = 5 ml/kg, RR = 60/min, PEEP = 9 cm H2O. Animals were ventilated for an additional 3 h and then killed, and lung lavage fluid was analyzed. Animals ventilated with the low-VT modes (Low VT [5 cm H2O] and Low VT [9 cm H2O]) had higher PaO2 values (430 +/- 7 mm Hg and 425 +/- 18 mm Hg versus 328 +/- 13 mm Hg) and higher percentages of surfactant in large aggregate forms (83 +/- 2% and 82 +/- 2% versus 67 +/- 4%) at 3 h after treatment than did the Normal VT (5 cm H2O) group (p < 0.05). Increasing the PEEP level was beneficial for a short period after surfactant administration to maintain oxygenation, but did not affect exogenous surfactant aggregate conversion. We speculate that ventilation strategies resulting in low exogenous surfactant aggregate conversion will result in superior physiologic responses to exogenous surfactant.

Animals↗

PubMed1997

A convenient and efficient moldable dressing for skin grafts.

In this paper we present our positive experience with use of Aquaplast thermoplastic as a tie-down dressing for securing and maintaining skin grafts in good position against their nutrient recipient beds. This unique polymer is safe to use, simple to apply, and maintains uniform pressure across the entire surface of the skin graft, no matter how contoured the shape of the anatomical region.

Bandages↗

PubMed1997

Ventilation strategies affect surfactant aggregate conversion in acute lung injury.

This study evaluated the effects of varying tidal volumes (VT) and positive end-expiratory pressure (PEEP) levels on surfactant aggregate conversion and lung function in an animal model of lung injury induced by N-nitroso-N-methylurethane. Lung-injured adult rabbits were initially ventilated using a VT of 10 ml/kg (VT10), a respiratory rate of 30 breaths/min (RR30), and a PEEP of 3.5 cm H2O. A trace dose of radiolabeled rabbit large surfactant aggregates was instilled after the onset of ventilation, and animals were then ventilated at different ventilator settings for 1 h. Ventilation strategies involving a lower VT (VT5, RR60) resulted in significantly superior oxygenation and lower surfactant aggregate conversion rates than strategies involving a higher VT ([VT10, RR30], [VT15, RR20], p < 0.05). Increasing the PEEP level to 8.0 cm H2O improved oxygenation, but it was sustained only with a low VT (VT5, RR60), and deteriorated with a high VT (VT10, RR30). Varying VT but not PEEP levels resulted in significant changes in surfactant aggregate conversion. We conclude that increased surfactant aggregate conversion resulting from suboptimal ventilation of injured lungs may play an important role in the pathophysiology of ventilation-induced lung dysfunction in acute lung injury.

Animals↗

PubMed1991

Emerging differences between 5-HT3 receptor antagonists.

A brief review is presented of some recently described 5-HT3 receptor antagonists. These antagonists are primarily targeted for use as anti-emetics. However, evidence is emerging that there are differences in their basic pharmacology. This evidence is reviewed in terms of the selectivity of the antagonists in binding studies and also of their efficacy in emesis and gastric emptying. The possibility that these differences may translate into meaningful clinical differences between the available 5-HT3 receptor antagonists in their use as anti-emetics is also discussed.

Animals↗

PubMed1980

The radioimmunoassay of buprenorphine.

Antisera to buprenorphine were obtained in rabbits immunised with 3-0-carboxymethylbuprenorphine and N-hemisuccinyl-norbuprenorphine conjugated to bovine serum albumin. Using the latter antiserum and tritium labelled buprenorphine a radioimmunoassay have good accuracy and precision was developed for concentrations as low as 50 picograms in 1 ml of plasma. The N-hemisuccinyl antiserum crossreacted with norbuprenorphine, and the 3-0-glucuronide conjugate with the 3-0-carboxymethyl antiserum. Cross-reactivity of both antisera to other pharmacologically related compounds was negligible. The assay was employed to determine plasma buprenorphine concentration following its parenteral administration to dog and man.

Animals↗