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Biomedical subjects

B Britton

Publications and source records attributed to B Britton.

7 recordsLinked to original sources
PubMed1996

Exogenous surfactants in a piglet model of acute respiratory distress syndrome.

Evidence for surfactant dysfunction in acute respiratory distress syndrome (ARDS) suggests a role for exogenous surfactant which contains apoprotein for resistance to protein inhibition. We compared the effects of KL-4-Surfactant, an artificial preparation containing a synthetic 21 amino acid peptide with SP-B-like activity, with Exosurf, an artificial protein-free surfactant, and Survanta, a bovine protein-containing surfactant, in a saline lung lavage model of ARDS in neonatal piglets. Two sequential series of lung lavages were performed to lower PaO2 < 100 mm Hg, each followed by administration of surfactant or air and a 90-min observation period. Progressive lung injury was demonstrated by deterioration in pulmonary function, increasing bronchoalveolar lavage protein, and changes in histopathology. All surfactants improved oxygenation, although oxygenation was generally better with Survanta and KL-4-Surfactant. Further, Survanta and KL-4-Surfactant groups showed improvement in ventilation, with decreases in PaCO2 and increases in FRC. Only KL-4-Surfactant demonstrated greater pressure-volume characteristics and lower bronchoalveolar protein than those of Controls. We conclude that the physiologic effects of KL-4-Surfactant are more like Survanta in this model. We speculate that KL-4-Surfactant may improve pulmonary function, reduce alveolar protein leak, and thus be efficacious in the treatment of ARDS.

Animals↗
PubMed1994

Proliferative activity as an adjunct in the diagnosis of prostatic adenocarcinoma.

Sixty-nine men underwent transrectal ultrasound-directed biopsy of the prostate. One biopsy core from each side of each gland was sent for DNA flow cytometric testing (138 total specimens). Results were correlated with findings from standard hematoxylin and eosin staining of other cores. Twelve patients (17.4%) had biopsies with histopathologic evidence of prostatic carcinoma. Of 57 patients (82.6%) with benign biopsies, two had stage A prostate adenocarcinoma noted on subsequent transurethral resection. Proliferative activity was calculated from DNA histograms by adding the percentage of nuclei in the proliferative (S and G2/M) phases of the cell-division cycle. Mean proliferative activity for the malignant group (19.08) was significantly higher (p < 0.001) than that of the benign group (13.43). Inflammation was associated with elevated proliferative activity scores among benign glands. Proliferative activity is an objective, easily obtainable indicator of the biological activity of a population of cells which, when elevated, may suggest a need for repeat biopsy in patients with otherwise normal prostate biopsies. Flow cytometry may have value as a complement to standard histologic analysis of transrectal core biopsies in the diagnosis of prostate cancer.

Adenocarcinoma↗
PubMed1992

Level of care for deinstitutionalized psychiatric patients.

The New York state Level-of-Care Survey (LOCS) was used in 1987-88 to assess the community care and social support needs of 936 mentally disabled community residents in Halifax, Nova Scotia. The cases were assigned an appropriate level-of-care by the computerized algorithm based on an 101-item questionnaire covering all aspects of the cases' physical and mental condition, needs and activities. Compared with their current setting, the algorithm assigned 60% of cases to the same level-of-care, 17% to a lower level, and 23% to a higher level-of-care. The net effect on social service costs of the reassignments would be a 7% increase. The increased costs for some cases ($1.5 million) would be partly offset by lowered costs for others ($900,000). The gradual shifting of 14 cases from the relatively expensive rehabilitation unit to more independent living at lower levels of care would compensate for most of the increases.

Aged↗
PubMed1977

Biocompatibility and bioabsorption of microfibrillar collagen hemostat in experimental animals.

The effects of Microfibrillar Collagen Hemostat (MCH) and Gelfoam after surgical implantation into incision sites of the liver, kidney, and brain were studied in beagle dogs, rabbits, and beagle dogs, respectively. The results of these experimental animal studies suggest that MCH is comparable to Gelfoam with respect to biocompatibility, rate of bioassimilation, and a lack for adverse systemic effects. The brain, liver, and kidney tissues responded comparably to MCH and Gelfoam with a mild to moderate infiltration of macrophages and mononuclear cells. Most of the hemostatic compound had disappeared from the incision sites by Day 28 and completely disappeared by Day 84. The tissue degree response was interpreted as a factor in the process of bioassimilation of the two hemostatic materials. Both hemostatic compounds contributed to adhesion formation in the experimental models. The incidence of adhesions was somewhat lower for MCH than for Gelfoam, but both produced more adhesions than were found at the control sites. The adhesions were only to the adjacent structures and always localized to the surgical site. When MCH or Gelfoam is used under conditions similar to those in the present experimental study, where tissue approximation is impaired, and where growth of granulation tissue is stimulated by the physical presence of the hemostatic compound, there is the possibility for increased incidence of adhesion formation. However, when an intraperitoneal absorbable hemostatic compound is desired, the present studies in experimental animals suggest that MCH will be safe by exhibiting minimal tissue reaction.

Absorption↗
PubMed1976

Intraocular irritation evaluation of benzalkonium chloride in rabbits.

The purpose of this study was to define the threshold for intraocular irritation of benzalkonium chloride, a preservative used in some formulations which enter the anterior segment of the eye during ocular surgery. Various concentrations of benzalkonium were injected into anterior chambers of albino rabbit eyes. Conjunctivitis, flare, iritis, and corneal changes occurred in a dose response pattern. The threshold of irritation was 0.03%, with highest nonirritating concentration being 0.01%. In other works in this laboratory, threshold of irritation for topical ocular benzalkonium was 0.05%, but the nature of ocular changes was less substantial than those observed intraocularly. Because the threshold for intraocular irritation is less than that topically, the nature of ocular changes was different for two routes, and there is a paucity of clinical data for intraocular benzalkonium chloride, a safety factor of 10 was utilized in setting the highest safe concentration of 0.001% for intraocular use. The preservative efficacy of 0.001% is questionable; therefore, we cannot endorse benzalkonium chloride as a preservative for formulations which will enter the anterior segment of the eye.

Administration, Topical↗