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Biomedical subjects

R S Patterson

Publications and source records attributed to R S Patterson.

At least 55 records · Page 3Linked to original sources
PubMed1989

Pharmacodynamics of malathion and carbaryl in susceptible and multiresistant German cockroaches (Dictyoptera: Blattellidae).

Studies with malathion and carbaryl were done to compare toxicity; absorption, metabolism, internal accumulation, and excretion; and in vivo inhibition of acetylcholinesterase (AChE) after topical applications to adult male susceptible (S, Orlando normal) or multiresistant (R, HRDC) German cockroaches, Blattella germanica (L.). Compared with the S strain, R cockroaches were highly resistant to malathion (about 33-fold) and only moderately resistant or tolerant to carbaryl (about 5-fold). Tests with topically applied 14C-labeled malathion and carbaryl indicated that both compounds penetrated rapidly and radioactive products were readily excreted. Rates of absorption or excretion in S and R strains did not differ significantly. Both insecticides were extensively metabolized; each yielded the same array and similar concentrations of metabolites in insects from either strain. In contrast, metabolic detoxification of malathion and carbaryl was significantly greater in R cockroaches when the insects were treated by injection. Strains did not differ significantly in the in vitro inhibition of brain AChE by either malaoxon or carbaryl. However, dramatic differences were observed between strains in the in vivo inhibition of AChE during a 6-h test period after topical treatment with malathion, and moderate but significant differences occurred between strains in the in vivo inhibition of AChE by carbaryl. These data suggest that the strong resistance to malathion and moderate resistance or tolerance to carbaryl in R cockroaches is probably a result of enhanced capability for metabolic detoxification.

Animals↗
PubMed1987

Transconjunctival lateral canthopexy in Down's syndrome patients: a nonstigmatizing approach.

In Down's syndrome patients, surgical correction of the palpebral fissure obliquity through an external approach may produce a red, slightly hypertrophic scar. A transconjunctival approach for this repair was used for 15 Down's syndrome patients aged 3 to 17 years (mean 8.7 years), and the results were compared with those in two boys aged 6 and 17 years who underwent correction by the external approach. Palpebral fissure inclinations were recorded using anthropometric measurements preoperatively and 6 months postoperatively. Inclinations were reduced significantly by either technique; however, often the precise degree of the improvement was clear only from the measurements rather than from photographs. Complications of the transconjunctival approach were few, and there were no problems with wound healing and no ocular injury. Transconjunctival lateral canthopexy is a safe, effective method that avoids a potentially stigmatizing external scar.

Adolescent↗
PubMed1985

Early postoperative nutritional enhancement utilizing enteral branched-chain amino acids by way of a needle catheter jejunostomy.

Twenty patients who underwent extensive intraabdominal surgical procedures and placement of a needle catheter jejunostomy were prospectively studied to evaluate gastrointestinal tolerance and nutritional enhancement when fed an enteral branched-chain amino acid-enriched diet. At a mean caloric intake of 1,325.75 kcal/day (20.6 kcal/kg per day) and a mean nitrogen intake of 7.64 g/day (0.12 g/kg per day), positive nitrogen balance was achieved 2 to 3 days postoperatively. Total lymphocyte count and levels of transferrin and prealbumin increased significantly (p less than 0.05) during the study. Gastrointestinal tolerance was excellent. Plasma levels of leucine, isoleucine, and valine increased significantly during the study period but remained within the normal range.

Abdomen↗
PubMed1983

Long-term nutritional assessment of patients with esophageal atresia and/or tracheoesophageal fistula.

Fifty-three patients operated for esophageal atresia and/or tracheoesophageal fistula at the Childrens Hospital of Los Angeles returned for long-term nutritional assessment. The ages ranged from 11 months to 31 years of age with a mean age of 9 years 11 months. Nineteen percent of the patients were below the third percentile in height for their age, thus exhibiting evidence of chronic malnutrition. No significant differences could be demonstrated between patients with a birth weight above or below 2500 g or above or below 5 years of age. Patients over 13 years of age demonstrated considerably less evidence of chronic malnutrition (p less than .06), thus exhibiting a "catch-up" growth phenomenon. Associated anomalies and illnesses were frequently seen in patients with the most significant abnormal nutritional-assessment parameters. Nutritional assessment should be part of long-term management and follow-up of all patients with esophageal atresia or other congenital surgical anomalies.

Adolescent↗