Biomedical subjects
Publications and source records attributed to D Egan.
The electrochemical behaviour of 7-OH-coumarin at the bare glassy carbon electrode has been studied using differential pulse voltammetry, and based on anodic detection of this metabolite at 0.66 V (vs SCE) using DC amperometry, a method has been developed for the determination of 7-OH-coumarin levels in urine samples, and a pharmacokinetic profile established.
An amperometric biosensor, based on an anti-7-hydroxycoumarin (7-OH-coumarin) antibody immobilized at the surface of a glassy carbon electrode, and contained behind a cellulose dialysis membrane, is described. The electrochemical behaviour of this metabolite at the bare glassy carbon electrode was found to be well defined by using differential-pulse voltammetry, and a 90% decrease in peak height was observed on binding of the antibody to the antigen, which occurs at the electroactive site of 7-OH-coumarin. The kinetics of the antibody-antigen reaction was investigated and a first-order reaction was observed with k = 0.0329 mA min-1. This system provides a novel method for studying antibody specificity and the kinetics of such antibody-antigen interactions.
We analyzed clinical data on 22,739 contact lens wearers who were studied and whose lenses were approved under 48 manufacturer-sponsored studies for the Food and Drug Administration between 1980 and 1988. The incidence of corneal ulcers was low in the cosmetic (nontherapeutic) daily-wear soft and rigid gas-permeable lens wearers (1/1,923 and 1/1,471 patient-years, respectively). Corneal ulcers and severe adverse reactions occurred two to four times more frequently in extended-wear cosmetic soft and rigid gas-permeable lens wearers than in cosmetic daily-wear lens wearers. Aphakic extended-wear soft lens users were nine times more likely to develop a corneal ulcer when compared to the soft daily-wear cosmetic group. Corneal abrasions and keratitis accounted for 81 of 159 severe adverse reactions, whereas corneal ulcers accounted for 28 of 159 adverse reactions. The data indicate that overnight extended wear of contact lenses is associated with a greater risk of serious, sight-threatening complications than daily wear.
Previous investigations of in vitro fertilization (IVF) cycles stimulated with gonadotropins have shown that it is possible to predict IVF outcome on the basis of the pattern of estradiol (E2) production in the terminal phase of follicular growth. This analysis looked at endocrine and ultrasound parameters in the late follicular phase of 320 patients in their first cycle of IVF. All cycles were stimulated by an association of gonadotropin-releasing hormone agonists (GnRH-a) and human menopausal gonadotropins (hMG). The pregnancy rate (PR) was not related to the E2 pattern in the 5 days before ovulation induction and was 33% and 39% even when E2 values fell during hMG administration. The PR was independent of the E2 level and the number of follicles greater than 14 mm on the day of human chorionic gonadotropin administration (day 0). The incidence of multiple pregnancy increased when E2 levels were greater than 1,000 pg/mL. It is concluded that follicular phase parameters used for cycle cancellation in hMG-stimulated IVF cycles cannot be extrapolated to GnRH-a/hMG cycles.
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Severe ovarian hyperstimulation syndrome (OHSS) was recorded in 8 of 413 patients after the use of gonadotropin-releasing hormone agonists (GnRH-a) associated with gonadotropins for in vitro fertilization. Seven of the 8 patients were pregnant. Common factors associated with the development of OHSS were high serum estradiol values on the day of ovulation induction and many follicles greater than or equal to 12 mm. Based on this experience, a new therapeutic schedule was used in a group of 10 patients who, after GnRH-a and gonadotropin stimulation, were judged to be at high risk of OHSS on the day of human chorionic gonadotropin (hCG). No hCG was administered and gonadotropins were stopped. The administration of GnRH-a was continued and, after a further period of pituitary desensitization, follicular stimulation was recommended with a lower dose of gonadotropins. No cases of OHSS occurred and 3 patients became pregnant.
Three patients had an undetected pregnancy when they commenced a GnRH-a on the 21st day of their cycle before ovulation stimulation for IVF. Two of the three pregnancies were later diagnosed as ectopic gestations. Based on this and previous case reports in the literature, it is suggested that luteal phase administration of GnRH-a may predispose to EPs, particularly in patients with damaged tubes, by reducing tubal motility secondary to a transient increase in circulating P concentrations.
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More competition for finite resources and increasing regulation have led many hospitals to consider a strategic reorganization. Recently, one common reorganization strategy has been"product line management." Product line management can be broadly defined in terms of centralized program management, planning, and marketing strategies. In Canada, while strategic driving forces may be different, a product line management alternative has arisen in one of the most potentially complex product lines, cancer services. This article compares and contrasts the theoretical model for product line management development, with special reference to cancer services, to the experience of one Canadian medical center and cancer center.
A marked decrease in renal blood flow (RBF) and glomerular filtration rate (GFR) was found after 24, 48 and 72 hours of total unilateral ureteral obstruction (UUO) in the rabbit. Contralateral GFR showed a modest increase consistent with compensatory hypertrophy. The urinary excretion of thromboxane B2 (TxB2), the stable metabolite of the vasoconstrictor prostaglandin, thromboxane A2 (TxA2) was significantly elevated in the urine obtained following release of the obstructed ureter when compared to the TxB2 level in the urine from the contralateral kidney. Continuous infusion of OKY-046 at 100 micrograms./kg./min. over 24 hours during UUO decreased TxB2 excretion by greater than 80 per cent. However there was no significant preservation of RBF or GFR of the obstructed kidney following ureteral release despite the selective inhibition of TxA2. Moreover the increase in contralateral GFR was also abolished. Taken together with other studies these results strongly suggest that the potent vasoconstrictor TxA2 is not responsible for the rise in renal resistance that follows acute UUO.
A rapidly progressive destructive spondyloarthropathy that resembles infectious spondylitis is reported in four patients undergoing long-term hemodialysis for chronic renal disease. Its characteristics are similar to those of a recently recognized entity reported in ten patients in the rheumatology literature. It is believed that the alterations represent a crystal-induced arthropathy because these crystals are known to cause destructive arthropathy in extra-spinal sites, the association of crystal deposits and chronic renal disease in patients undergoing dialysis is well recognized, and calcium hydroxyapatite and calcium pyrophosphate have been recovered from biopsy material in two of the reported 14 cases. Patients with chronic renal disease in whom a rapidly destructive spinal arthropathy develops should have a biopsy of the affected area to exclude infection. Because a crystal-induced destructive process may simulate infection, crystalline analysis should also be performed on the biopsy material.
Needs assessments are conducted with the expectation that the information obtained will be used to make rational decisions. However, appropriate planning and service delivery decisions do not always flow from needs assessment information. Assessment of the anticipated utilization of needs assessment data, and evaluation of the appropriateness of these uses prior to conducting a needs assessment may prevent inefficient use of resources. The present study evaluated the willingness and ability of community mental health leaders to use needs assessment data. A structured interview was developed which tapped into several dimensions relevant to the evaluation of the need for a needs assessment. The most striking result was that when asked how they would use future needs assessment data, all respondents indicated that the results would not influence service delivery patterns. Strategies to facilitate the constructive use of information gained from needs assessments are discussed.
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Explore the source record for details and available documents.
The authors conducted a controlled study in which families who had experienced the sudden death of a family member were given crisis intervention services and compared at follow-up with two untreated control groups. Results did not support the hypothesis that such services decrease the risk of psychiatric illness, disturbed family functioning, or increased social cost to the families. The authors suggest that environmental and social systems factors and individual variables are powerful predictors of outcome in bereavement.