PubMed Health⌕ Search

Biomedical subjects

B K Wilson

Publications and source records attributed to B K Wilson.

11 recordsLinked to original sources
PubMed1993

Converting to gamma-radiation sterilization: an overview for medical device manufacturers.

Gamma radiation is becoming increasingly popular as a method of sterilizing disposable medical devices. The conversion from ethylene oxide sterilization to gamma radiation may involve redesigning products and packaging, and establishing a new method of sterilization. However, the conversion process can be regarded as an opportunity to enhance product design, improve processes, and reduce costs. In this article, the authors explain how conversion can be manageably achieved by providing a step-by-step conversion programme.

Equipment Contamination↗
PubMed1989

Neuropeptide Y potentiates excitation of supraoptic neurosecretory cells by noradrenaline.

The effects of neuropeptide Y (NPY) and noradrenaline (NA) on the activity of rat supraoptic nucleus (SON) neurosecretory cells were examined using perfused hypothalamic slices. Bath application of either NPY (10(-9)-10(-6) M) or NA (10(-6)-10(-3) M) excited SON cells, although only NA elicited consistent, dose-dependent effects. Application of NPY at a dose having virtually no direct effects (10(-8) M) produced a 5-fold increase in SON cell responsiveness to NA at the sub-maximal response dose of 10(-5) M, but did not alter the minimum concentration of NA required to excite SON cells or increase the maximal response elicited by higher NA concentrations. The effects of NA, alone or in combination with NPY, were abolished by alpha-adrenoreceptor blockade. These data suggest that NPY has only weak direct effects on neurosecretory cells, but may have important neuromodulatory actions, significantly enhancing the excitatory effects of NA.

Action Potentials↗
PubMed1982

MMPI profiles of rheumatic fever adolescents and adults.

MMPI elevations for adolescent and adult groups (N = 162) who had experienced rheumatic fever (RF) were generally lower than Mayo Clinic norms, particularly on scales K, 1, 2, 3, and 6. Significant age effects on Scales F, 3, 4, 8, and 9 confirm previous findings that adolescent groups score higher on the MMPI. Contrary to expectation, patients who had not experienced carditis as part of their RF scored significantly higher than carditis patients on scales 2, 3, and 4. The results are discussed from a chronic disease perspective.

Adolescent↗
PubMed1977

Plasma l-alpha-Acetylmethadol (LAAM) after acute and chronic administration.

l-alpha-Acetylmethadol (LAAM) was administered orally to two groups of subjects; one group received methadone, 50 mg/day, for three months previously and the other group were heroin addicts who had no prior exposure to methadone or LAAM. Plasma elimination curves for methadone, LAAM, and its metabolites, noracetylmethadol (N-LAAM) and dinoracetylmethadol (DN-LAAM), were determined after acute and chronic administration. The plasma decay curve for LAAM was biexpoenential (t1/2alpha = 6 hr; t1/2beta greater than 50 hr) following acute or chronic administration. Following chronic administration, N-LAAM and DN-LAAM plasma levels increased 5- to 10-fold. At this time, N-LAAM had a t1/2 of 31 hr and DN-LAAM had a t1/2 of greater than 100 hr. There appear to be at least two factors which determine the long duration of action of LAAM: metabolic conversion to active metabolites and tissue or plasma binding. Both methadone and LAAM may compete for plasma protein or tissue binding sites. The clinical implications of this potential drug-drug interaction are discussed.

Adult↗
PubMed1975

Outpatient vs hospital methadone detoxification: an experimental comparison.

This study compares the effectiveness and cost of hospital narcotic detoxificationand outpatient narcotic detoxification using methadone. Forty heroin addicts seeking narcotic withdrawal were randomly assigned to treatment groups. Methadone treatment was planned for no longer than 10 days while psychiatric supportive services were made available to continue as needed. The results suggest little benefit from either treatment approach and there was no significant differences between the treatments. Only a few patients achieved a drug-free state, and of those who did, all but one had returned to use of narcotics within 2 months. The data indicate that detoxification using methadone is a palliative procedure. The cost of outpatient detoxification can be accomplished for approximately one-tenth the cost of inhospital treatment without significantlyaltering the effectiveness of treatment.

Administration, Oral↗
PubMedDate not supplied

Glucuronidation of propranolol by dog liver microsomes. Effects of enantiomeric inhibition and detergent treatment on stereoselectivity.

The diastereomeric glucuronides of (R)- and (S)-propranolol [(R)-PG and (S)-PG] formed by incubating the racemic drug with dog liver microsomes were separated and quantitated chromatographically. Conjugation occurred stereoselectively with 3- to 4-fold more (S)-PG than (R)-PG produced. The values for the apparent Km were 1.0 and 1.7 mM, and those of the Vmax were 6.4 and 25 nmol/min/mg protein for (R)- and (S)-propranolol, respectively. Stereoselectivity was lower in parallel incubations conducted with the separate enantiomers than in incubates with the racemic substrate. The S enantiomer was found to be a noncompetitive inhibitor of (R)-PG formation, with a Ki of 1.8 mM. (S)-PG did not inhibit (R)-PG formation when added to incubates and (R)-propranolol did not inhibit the formation of (S)-PG. The presence of sodium cholate and Brij 35 stimulated glucuronidation by 60 and 120%, respectively, but did not affect the stereoselectivity even at concentrations high enough to inhibit conjugation. On the contrary, Triton X-100 and Emulgen 911 were inhibitory and produced a decrease in stereoselectivity; the magnitude of these effects increased with increasing detergent concentration.

Animals↗