Search PubMed⌕ Search

Biomedical subjects

K Kirby

Publications and source records attributed to K Kirby.

28 records · Page 2Linked to original sources
PubMed1990

Transfer and expression of an organophosphate insecticide-degrading gene from Pseudomonas in Drosophila melanogaster.

The organophosphorus acid hydrolases represent a distinct class of enzymes that catalyze the hydrolysis of a variety of organophosphate substrates, including many insecticides and their structural analogues. The plasmid-borne opd gene of Pseudomonas diminuta strain MG specifies an organophosphorus acid hydrolase, a phosphotriesterase, that has been well characterized and can hydrolyze a broad spectrum of insect and mammalian neurotoxins. The in situ functioning of this enzyme in the metabolism of organophosphates has been analyzed directly in insects by transferring the opd gene into embryos of Drosophila melanogaster by P element-mediated transformation. The chromosomal locations of this stably inherited transgenic locus differed from strain to strain and demonstrated various expressivity on the whole-insect basis. Transcriptional induction of opd in one of these strains under control of the Drosophila heat shock promoter, hsp70, resulted in the synthesis of stable active enzyme that accumulated to high levels with repeated induction. The heat shock-induced synthesis of organophosphorus acid hydrolases in transgenic flies conferred enhanced resistance to toxic paralysis by the organophosphate insecticide paraoxon.

Animals↗
PubMed1988

Prostatectomy in patients with bleeding disorders.

Urological surgery is becoming increasingly necessary in patients with acquired or congenital bleeding disorders. We reviewed the management of 10 such patients who required prostatectomy. The average age of the patients at operation was 65.7 years. Seven patients underwent transurethral prostatectomy and 3 underwent suprapubic prostatectomy. Postoperative bleeding occurred in 9 patients who required secondary procedures. Bleeding occurred an average of 13 days postoperatively. The mean hospital stay was 24 days. Partial thromboplastin time when determined was uniformly elevated in all patients preoperatively. The amount of factor and blood replacement is presented. Perioperative management of these patients is discussed in detail. A rational approach for the prevention of postoperative bleeding is presented.

Adult↗
PubMed1988

An inverse relationship between baseline fixed-interval response rate and the effects of a tandem response requirement.

Previous experiments examining the effects of adding a tandem fixed-ratio response requirement on fixed-interval schedule performance have reported inconsistent results. One variable that may account for such inconsistencies is the baseline response rate in the fixed-interval condition. This possibility was investigated in the present study. Rats were given histories with either interresponse times greater than 11 s or fixed-ratio 40 schedules of reinforcement, which engendered either relatively low or high rates of responding, respectively, in the subsequent fixed-interval condition. A tandem ratio response requirement (fixed-ratio 9) was then introduced. The effects of adding this tandem response requirement were inversely related to the baseline fixed-interval response rates; low rates of responding in the fixed-interval condition were markedly increased, whereas high rates of responding were relatively unaffected. This inverse relationship appears to be similar to the rate-dependent relations observed in behavioral pharmacology. These results may provide an explanation for the inconsistent findings reported in previous studies on tandem fixed-interval fixed-ratio schedules and suggest that principles of behavioral pharmacology research may be applicable to the study of the effects of nonpharmacological variables on schedule-controlled behavior.

Animals↗
PubMed1987

Hemiplegia and lower extremity amputation: double disability.

A retrospective study of 52 consecutive patients was conducted to determine the influence of certain factors on the ambulatory rehabilitation of patients with hemiplegia and lower extremity amputation. Factors studied included side of hemiplegia, laterality of disability, level of amputation, order of disability (amputation first or hemiplegia first), neuromuscular status, mental status, sex, age. The level of function was defined as independent, limited, or nonambulatory. Of 52 double-disability patients, thirty were fitted with a prosthesis. Eight patients attained independent prosthetic function while 16 patients were limited and six were nonambulatory. Factors such as ipsilateral BK amputation preceding hemiplegia, a good-to-fair neuromuscular status, and an intact mental status have been associated with better functional results. Although producing higher fitting rates, none of these factors has been found in the present study to be associated with statistically higher levels of ambulatory function. A good-to-fair neuromuscular status seemed to be the prime requisite for good ambulation with a prosthesis in a patient with the double disability of amputation and hemiplegia.

Aged↗
PubMed1986

Visceral nociception in developing rats.

Maturational changes in visceral nociception were measured in developing or adult rats challenged with hypertonic saline or acetylcholine. Chemically induced abdominal constrictions were absent in rats younger than 7 days of age, regardless of the dose of hypertonic saline or acetylcholine used. Age-related increases in the percent of animals responding, the number of abdominal constrictions emitted per responder, and total response duration occurred in animals 10-20 days of age, until adult-like patterns of responding were attained at the time of weaning. Additional changes in the percent animals responding, as well as in the frequency and total duration of abdominal constriction responses, were also seen in postweanling, but not in preweanling, animals. Five-day-old animals did emit audible vocalizations to the intraperitoneal insertion of a hypodermic needle, however, at a time when these animals failed to show observable responses to the noxious visceral stimuli. Hence, mechanisms mediating pain associated with intraperitoneal needle insertion may be functional during the first postnatal week, at a time when mechanisms mediating visceral pain appear to be immature. These differences may be caused by the differential maturation of sensory, neural, or motoric mechanisms important for hypodermic needle insertion versus visceral nociception.

Age Factors↗
PubMed1980

Canine hip dysplasia: breed effects.

This paper is a refinement of previous studies in that only suitably radiographed dogs were included in the data base. The rate of hip dysplasia varied widely by breed from five percent in siberian huskies to eighty-three percent in english bulldogs. There was a significant difference in the prevalence of dysplasia within at least two breeds; golden retrievers and old english sheepdogs. Physical size per se did not appear to be an important determinant of hip dysplasia.

Animals↗