Biomedical subjects

T P O'Brien

Publications and source records attributed to T P O'Brien.

At least 73 records · Page 4Linked to original sources

PubMed1989

Collagen corneal shields enhance penetration of topical prednisolone acetate.

We used an animal model to compare the corneal and aqueous penetration of topical prednisolone acetate 1% with and without the presence of a commercially available collagen corneal shield. A significant (P less than .02) increase in penetration into cornea and aqueous humor at 30 minutes and 120 minutes was found in eyes with a collagen corneal shield in place. Increased concentrations were achieved by soaking the shield in prednisolone acetate for 15 minutes prior to application.

Administration, Topical↗

PubMed1989

Enhancing lineup identification accuracy: two codes are better than one.

Ways of improving identification accuracy were explored by comparing the conventional visual lineup with an auditory/visual lineup, one that paired color photographs with voice recordings. This bimodal lineup necessitated sequential presentation of lineup members; Experiment 1 showed that performance in sequential lineups was better than performance in traditional simultaneous lineups. In Experiments 2A and 2B unimodal and bimodal lineups were compared by using a multiple-lineup paradigm: Ss viewed 3 videotaped episodes depicting standard police procedures and were tested in 4 sequential lineups. Bimodal lineups were more diagnostic than either visual or auditory lineups alone. The bimodal lineup led to a 126% improvement in number of correct identifications over the conventional visual lineup, with no concomitant increase in number of false identifications. These results imply strongly that bimodal procedures should be adopted in real-world lineups. The nature of memorial processes underlying this bimodal advantage is discussed.

Crime↗

PubMed1988

Use of collagen corneal shields in the treatment of bacterial keratitis.

We used an animal model of Pseudomonas keratitis to compare treatment by topical tobramycin with and without the presence of a commercially available collagen corneal shield. Pilot studies showed a significant, 30-fold increase in penetration of tobramycin into the anterior chamber in eyes with a collagen shield in place. Twenty albino rabbit eyes were inoculated with P. aeruginosa to produce stromal keratitis. After 12 hours of topical tobramycin dosing, eyes with a collagen corneal shield in place had a statistically significant (P less than .01) decrease in colony forming unit counts in comparison to treated eyes without a shield and control eyes.

Animals↗

PubMed1988

Topical imipenem therapy of aminoglycoside-resistant Pseudomonas keratitis in rabbits.

We used a rabbit model of bacterial keratitis to assess in vivo efficacy of topical imipenem, a highly potent beta-lactam antibiotic with an unusually broad spectrum of activity, including aminoglycoside-resistant Pseudomonas aeruginosa. Albino rabbits received intrastromal injections of 5 x 10(2) organisms of an aminoglycoside-resistant strain of P. aeruginosa. At five hours postinoculation, imipenem (5 mg/ml) therapy was initiated using one drop per 30 minutes for 12 hours. Corneal tissue was then excised for colony forming unit counts. Imipenem was highly effective in reducing colony forming unit counts to zero in comparison to 4.1 x 10(5) organisms for untreated controls. A second regimen beginning 24 hours postinoculation of one drop per hour for 24 hours was also successful in significantly reducing colony forming units vs controls (P less than .05). These data suggest that topical imipenem may have clinical applicability in the treatment of P. aeruginosa keratitis.

Administration, Topical↗

PubMed1988

Topical ciprofloxacin treatment of Pseudomonas keratitis in rabbits.

Ciprofloxacin is a new quinolone antibiotic that is highly active in vitro against Pseudomonas aeruginosa. A rabbit model of bacterial keratitis was used to assess the in vivo efficacy of topical ciprofloxacin. Albino rabbits received intrastromal injections of 5 X 10(2) aminoglycoside-resistant P aeruginosa organisms. At five hours after inoculation, ciprofloxacin (3 mg/mL) therapy was initiated (one drop every 30 minutes for 12 hours). Corneal tissue was then excised for bacterial colony counts. No organisms were recovered from ciprofloxacin-treated eyes, compared with an average of 3.1 X 10(7) organisms per milliliter recovered from untreated controls. This model suggests that topical ciprofloxacin may be clinically useful in the treatment of aminoglycoside-resistant P aeruginosa keratitis.

Administration, Topical↗

PubMed1988

Use of collagen corneal shields versus soft contact lenses to enhance penetration of topical tobramycin.

We compared the corneal penetration in rabbits of topical tobramycin in the presence of collagen corneal shields and bandage soft contact lenses. A collagen corneal shield was placed on six albino rabbit eyes, while therapeutic soft contact lenses (61.4% poly-2-hydroxyethyl-methacrylate/38.6% water) were placed on six eyes. Four control eyes received no shield or contact lens. Topical tobramycin was applied to all 16 eyes every five minutes for six doses. Samples of aqueous humor were removed at 15 and 60 minutes following the last dose. Collagen corneal shields allowed a significant (P less than .05) increase in tobramycin penetration into the anterior chamber at 60 minutes compared with hydrophilic soft contact lenses or controls.

Administration, Topical↗

PubMed1983

Adolescent self-poisoning: a nine-year followup.

A 9-year followup was made of 47 adolescents initially hospitalized at ages 12 to 18 years in a psychiatric facility because of severe psychosocial dysfunction associated with an intentional self-poisoning. No deaths were disclosed as determined by an extensive telephone interview (15 subjects), report by the family (9 subjects), or death certificate search. The 15 subjects interviewed (14 females, 1 male) reported a total of 47 suicide gestures with a peak frequency at ages 14 to 15. There was a sharp decline after age 18, supporting the concept that self-poisoning is an age-related mode of expression. All subjects considered themselves better adjusted, with greater life satisfaction and improved interpersonal relationships; 80% had completed high school, and 93% were capable of stable employment. Functional adaptation was independent to the number of repeat poisonings or of the initial psychiatric diagnosis. All subjects attributed benefits to multiple support systems, particularly a strong relationship with at least one emotionally mature person, a more favorable environment--usually accomplished by moving out of their parents' house--achievement of education and employment skills, and economic independence.

Adaptation, Psychological↗

PubMed1983

The effects of a child's self-evaluation program on compliance with parental instructions in the home.

A self-evaluation program was implemented with a kindergarten-aged boy in the home to increase compliance with parent instructions and decrease inappropriate verbal behavior. The self-evaluation package included the child's assessing the appropriateness of his behavior in 5-min intervals, receiving chips for positive self-evaluations, and exchanging chips for a reward following experimental sessions. In a reversal design, analyses were conducted of the effectiveness of the self-evaluation program, the requisite conditions for effective child behavior change with a self-evaluation approach, and the parent's efficiency in using the self-evaluation package. The self-evaluation procedures typically resulted in increased compliant behavior and decreased inappropriate behavior, although the effects generally weakened with time. Behavioral gains were greater and better maintained when the self-evaluation procedures were preceded by a phase of external evaluation via the mother than by baseline, suggesting that self-evaluation procedures may serve more to maintain the effects of external evaluation rather than to induce their own changes. The parent generally was efficient in implementing the procedures. Research and clinical implications for using self-evaluation procedures in a home setting are discussed.

Behavior Therapy↗

PubMed1983

The preprophase band of microtubules: does it block cleavage?

The preprophase band of microtubules is known to predict the future plane of cytokinesis accurately in both symmetric and asymmetric divisions of the cell. Of the three major types of cytokinetic systems which are now known, so far there are no reports of systems that divide by cleavage having preprophase bands of microtubules. It is proposed that a major function of a preprohase band is to prevent the initiation of cleavage in systems which require the development of a phragmoplast to hold daughter nuclei apart after telophase.

Animals↗

PubMed1982

Naturalistic observation of the snack-selecting behavior of obese and nonobese children.

No previous study has examined the snack-selecting behavior of children although information from such a study may be useful in preventing and treating obesity or in determining its etiology. To provide data on this behavior, male (n=190) and female (n=166) children were unobtrusively observed purchasing snacks in either of two movie theaters. The amount of soft drinks and snack foods that were selected was recorded, and the corresponding caloric values were determined. Ratings were also made for obesity and sex. No differences for obesity or sex emerged on the measure of amount of calories selected. The implications of these results for the treatment of obesity are discussed.

Child↗

PubMed1980