Biomedical subjects

L Bowers

Publications and source records attributed to L Bowers.

At least 55 records · Page 3Linked to original sources

PubMed1996

Community psychiatric nurse education in the United Kingdom: 8 years of surveys and the issues raised.

Over the past 8 years annual surveys of the take-up and development of community psychiatric nursing courses within the United Kingdom have been conducted under the auspices of the Standing Advisory Group on Community Psychiatric Nurse Education (SAGCPNE). They reveal a clear link between changes in funding structure and numbers of community psychiatric nurses (CPNs) undertaking training, with recently implemented arrangements resulting in rises in student numbers. Rising numbers are not distributed evenly across course centres, with some courses showing more dramatic increases than others. As a consequence of Project 2000 and the UKCC PREP (Post-Registration Education and Practice policy), the surveys show that CPN courses have moved in many cases to diploma level and in some cases to degree level. A number of issues are raised by the changes charted by the surveys. Funding structures are set to change again within the next few years, and may have a negative impact upon CPN training. Market pressures have led to greater secrecy over curriculum content at a time when more openness could lead to shared improvements and greater uniformity of courses. In conjunction with these changes, government mental health policy has implications for CPN training. These issues are discussed and some modest recommendations made.

Community Health Nursing↗

PubMed1995

An in vivo 31P magnetic resonance spectroscopy study of uridine excess in rats fed orotic acid.

Spatially localized 31P NMR spectroscopy was used to assay in vivo the liver of intact rats fed orotic acid (OA) in a diet which produces hepatic steatosis. Twenty-three sets of multiple volume spectra were obtained from twenty-one 265- to 315-g female rats after 0-9 days of feeding either a 1% OA/64% sucrose diet (12 rats) or a 65% sucrose control diet (9 rats). The intensity of the in vivo diphosphodiester resonance ascribed to UDP-hexos(amin)es increased and the phosphomonoester resonance decreased in intensity prior to fatty infiltration. High resolution NMR spectroscopy of extracts of these livers indicated that the UDP-hexos(amin)e peak included four different UDP-sugars including UDP-N-acetylglucosamine (UDP-glcNAc), and that lower phosphocholine (P-Cho) accounted for the lower phosphomonoester resonance in vivo. Increased UDP-glcNAc is thought to reflect impaired lipoprotein glycosylation as a mechanism for hepatic steatosis in orotic acid feeding. P-Cho deficiency has been shown to be due to an increased rate of phosphatidylcholine synthesis. Low P-Cho concentration has been shown to be associated with lipid accumulation in a choline-deficient diet, but was not previously associated with hepatic steatosis in OA feeding. Changes in phosphorus metabolites were observed 2 days prior to development of fatty liver. HPLC assay of uridine nucleotides showed a good correlation between magnetic resonance spectroscopy and HPLC quantitation. In this study there were two biochemical correlates of impaired hepatic lipid secretion detectable by in vivo assay with 31P NMR spectroscopy. This method has application for noninvasive assays in ornithine transcarbamylase-deficient patients.

Animals↗

PubMed1994

Pharmacokinetics of FK506 after intravenous and oral administration in patients awaiting renal transplantation.

The authors examined the safety and pharmacokinetics of FK506, a new hepatically metabolized immunosuppressant, after single-dose intravenous (i.v.) infusion (20 micrograms.kg(-1) x 4 hours-1) and oral (80 micrograms/kg) administration in six nondialysis patients, aged 27 to 53 years, with chronic renal failure awaiting transplantation. A two-period, randomized, crossover study protocol was used with blood samples drawn for 72 hours after each dose and a washout period of 4 days. Whole-blood FK506 levels were determined using a standard, two-step, nonspecific enzyme immunoassay. There were no significant changes in vital signs, EKG, or complete laboratory test battery for any patient during the entire study period. No side effects were noted after i.v. or oral FK506 dosing. Mean +/- SD distribution half life was 0.9 +/- 0.2 hours, elimination half life (t1/2 beta) 33 +/- 8 hours, total body clearance (CL) 2.4 +/- 1.1 L/hour, and bioavailability 14 +/- 12%. There was no significant correlation between serum creatinine (Cr) and CL (r = 0.36) or between Cr and t1/2 beta (r = -0.30). It was found that FK506 is incompletely and erratically absorbed after oral administration and is rapidly distributed outside the blood compartment after IV dosing. An extended sampling period seems necessary to accurately characterize the slow elimination phase of FK506.

Administration, Oral↗

PubMed1992

Ethnomethodology. I: An approach to nursing research.

This is the first of two papers outlining and demonstrating an ethnomethodological perspective upon nursing research. The aim of this paper is to introduce the reader to some of the basic ideas of ethnomethodology, and to stimulate nursing researchers into questioning some of the presuppositions involved in their work. To this end ethnomethodology is explored through a series of contrasts between the conventional approach to the sociology of nursing and an ethnomethodological approach. To conclude, some of the areas of interest for ethnomethodological nursing research are outlined.

Ethnology↗

PubMed1992

Ethnomethodology. II: A study of the Community Psychiatric Nurse in the patient's home.

The former paper delineated the main points of ethnomethodology and its implications for nursing research. This paper describes a research study into the home visits of Community Psychiatric Nurses using the framework of ethnomethodology. Relevant sociological, psychological, medical and nursing literature is briefly reviewed. Home visits are found to be socially constructed events in which the sense of the talk is dependent upon the setting and context. The context of being in the home is shown to exert pressure upon how the developing events of the visit are construed by the participants. In particular, it is discovered that being a visitor in the patient's home tends to define the occasion of a Community Psychiatric Nurse visit as that of a meeting of friends. This is oriented to by the participants who draw upon their stock of typified knowledge of conduct of guests and hosts to make visible their desired definitions of the situation. The dynamics of power and control by the nurse are also altered by the location of the visit in the patient's home. Being in the home puts the patient firmly in charge, allowing him to take the lead at every turn. The nurse uses the strategies of persuasion and negotiation which can be enacted in the patient's home without fracturing the intersubjective understandings of the visit. Only in matters seen by both participants as clearly medico-psychiatric will the nurse become more assertive. Attention is drawn to some implications of these findings for the practice of Community Psychiatric Nursing.

Clinical Nursing Research↗

PubMed1992

Mizoribine pharmacokinetics and pharmacodynamics in a canine renal allograft model of local immunosuppression.

We utilized a canine renal transplant model to estimate the first-pass extraction of mizoribine (MZB) during renal artery infusion and to compare the efficacy and toxicity of continuous intraarterial (i.a.) versus intravenous (i.v.) MZB delivery, with and without a background of oral cyclosporine. Five autotransplanted mongrel dogs with programmable, implantable pump/catheter systems were given MZB by both i.v. bolus (5 mg/kg) and i.a. infusion (5.0 mg/kg/day). Mean +/- SD elimination half-life was 3.02 +/- 0.81 hr, and the transplanted kidney removed as much as 47-59% (mean 56%) of locally infused MZB. With increasing local and systemic MZB delivery in a single autografted dog undergoing both i.a. and i.v. pump/catheter placement, renal extraction decreased from at least 47% (5.0 mg/kg/day) to 33% (7.5 mg/kg/day), finally to 18% (10.0 mg/kg/day). A dose of 3.0 mg/kg/day MZB did not significantly prolong survival of renal allograft recipients over that of untreated controls (median survival time [MST] = 8 days) when administered either locally (MST = 9 days) or systemically (MST = 12 days). All dogs receiving 4.0 mg/kg/day MZB i.a. died from rejection, and a survival advantage was still not realized (MST = 7 days). In contrast, 4.0 mg/kg/day i.v. prolonged survival over controls (MST = 14 days; P = 0.03) but not when directly compared with the i.a. group (P = 0.30), and produced death from severe debility in five of seven animals with significantly higher mean systemic MZB levels (P = 0.02). Four of six dogs receiving 5.0 mg/kg/day MZB i.a. (MST = 14 days) and two of four dogs receiving 5.0 mg/kg/day i.v. (MST = 14 days) died from severe debility, though survival in both groups was prolonged over control values (P = 0.01 and P = 0.05, respectively). Coadministration of a subtherapeutic dose of oral CsA (5 mg/kg/day) significantly prolonged the overall survival of dogs receiving MZB 4.0 mg/kg/day i.a. (MST = 23; P = 0.01) but not i.v. (MST = 11; P = 1.00), so that a significant difference in overall survival between the combined MZB i.a. + CSA and MZB i.v. + CSA groups was now realized in favor of the former (P = 0.04). We conclude that at local doses required to achieve immunosuppression, the transplanted kidney was not able to extract enough MZB to prevent death from systemic toxicity, presumably as a result of saturation of renal elimination mechanisms, so that an overall survival benefit was not realized.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

PubMed1992

A preliminary description of the United Kingdom community psychiatric nursing literature, 1960-1990.

Five hundred and two items about community psychiatric nursing have been located and classified. The data indicate a continuing rising trend in the number of publications on this subject. The majority of the literature is about the clinical role of the community psychiatric nurse (CPN) and is descriptive/analytical in nature. The second largest proportion is research, the third largest topic is management and administration and the fourth largest is CPN education. The amount of 'clinical' literature as a proportion of the whole has been in decline since the mid-1970s. The majority of papers cannot be classified by the specialism of community psychiatric nursing to which they relate, but a small and significant number have been written about the care of the elderly mentally ill. Overall, the practising CPNs have been the most prolific writers, followed by academic nurses and then nurse managers. Contributions from other professions are miniscule. Over recent years the contribution of nurse managers has declined, and that of academic nurses has risen. The contribution of practising CPNs remains robust. Research publications also continue to rise, the majority being produced by academics, but large contributions are also being made by nurse managers and practising CPNs. In the early years nearly all publications of articles were in populist nursing magazines. In recent years the spread of journals in which items about community psychiatric nursing appear has widened considerably.

Bibliographies as Topic↗

PubMed1990

L5178Y mouse lymphoma cell mutation assay results with 41 compounds.

Forty-one chemicals were tested for their abilities to induce trifluorothymidine resistance in L5178Y mouse lymphoma (MOLY) cells. These chemicals were included in the National Toxicology Program's evaluation of four in vitro short-term toxicity assays for predicting carcinogenicity in the rodent bioassay. Of the 41 chemicals examined for this report, 8 were equivocal in the rodent bioassay, and 7 were questionable in- the MOLY assay. If these chemicals are eliminated from an analysis of concordance, the remaining 26 chemicals lead to a concordance of 69% with a sensitivity of 71%. The specificity could not be determined because only two non-carcinogens were detected.

Animals↗

PubMed1989

Rapid determination of methandrostenolone in equine urine by isotope dilution liquid chromatography-tandem mass spectrometry.

Urine samples were spiked with [17-methyl-2H3]methandrostenolone as internal standard and extracted with a mixture of dichloromethane and cyclohexane. The organic phase was concentrated and injected onto a short octyl-silica column (30 mm x 4.6 mm I.D.) for separation of methandrostenolone and 17-epimethandrostenolone. The effluent from the column was connected to a Sciex TAGA 6000E triple quadrupole mass spectrometer equipped with an atmospheric pressure ion source for sampling of ions generated by a heated pneumatic nebulizer with corona discharge ionization. This ion source produced abundant [M + H]+ ions and a weak fragment ion due to loss of water. The protonated molecular ions at m/z 301 and 304 for methandrostenolone, 17-epimethandrostenolone and the internal standard were transmitted to the second quadrupole for collision-induced dissociation. Quantification was obtained by selected reaction monitoring of three daughter ions. Methandrostenolone and 17-epimethandrostenolone were separated by liquid chromatography, but gave identical mass spectra. The method detection limit by injection of a urine extract corresponding to 2.8 ml urine was 180 pg/ml at the 99% confidence level. The precision (relative standard deviation) was 3% at the 16 ng/ml level and the linear dynamic range was at least 3 orders of magnitude. Screening for unknown metabolites in urine after administration of methandrostenolone to horses and humans was accomplished by a parent ion scan of m/z 121, a fragment corresponding to the intact A-ring of the steroids.

Animals↗

PubMed1989

Determination of methandrostenolone and its metabolites in equine plasma and urine by coupled-column liquid chromatography with ultraviolet detection and confirmation by tandem mass spectrometry.

Monitoring steroid use requires an understanding of the metabolism in the species in question and development of sensitive methods for screening of the steroid or its metabolites in urine. Qualitative information for confirmation of methandrostenolone and identification of its metabolites was primarily obtained by coupled-column high-performance liquid chromatography-tandem mass spectrometry. The steroids and a sulphuric acid conjugate were isolated and identified by their daughter ion mass spectra in the urine of both man and the horse following administration of methandrostenolone. Spontaneous hydrolysis of methandrostenolone sulphate gave 17-epimethandrostenolone and several dehydration products. This reaction had a half-life of 16 min in equine urine at 27 degrees C. Mono- and dihydroxylated metabolites were also identified. Several screening methods were evaluated for detection and confirmation of methandrostenolone use including thin-layer chromatography and high-performance liquid chromatography. Coupled-column liquid chromatography was used for automated clean-up of analytes difficult to isolate by manual methods. The recovery of methandrostenolone was 101 +/- 3.3% (mean +/- S.D.) at 6.5 ng/ml and both methandrostenolone and 17-epimethandrostenolone were quantified in urine by ultraviolet detection up to six days after a 250-mg intramuscular dose to a horse. The utility of on-line tandem mass spectrometry for confirmation of suspected metabolites is also shown.

Animals↗

PubMed1989

Liposomal formulation eliminates acute toxicity and pump incompatibility of parenteral cyclosporine.

The currently available intravenous dosage form of cyclosporine (CSA), Sandimmune I.V., contains the vehicle, Cremophor EL, which has been implicated in producing anaphylactic reactions in man and animals. This formulation also leaches through silicone tubing, an important component of some automatic drug delivery devices, causing pump dysfunction. In an attempt to develop a less toxic and pump-compatible formulation of CSA, suitable for intrarenal infusion in a canine transplant model, we compared the acute toxicity, pharmacokinetics, and pump compatibility of emulsified (CSA/emulsion) and liposomal (CSA/liposomes) CSA preparations with those of Sandimmune I.V. and CSA dissolved in ethanol vehicle (CSA/alcohol) in healthy, unoperated dogs. Animals receiving Sandimmune I.V. demonstrated marked acute toxicity despite progressive 10-fold dose reduction and greater than 50-fold prolongation of infusion duration. One of two animals receiving CSA/emulsion and both dogs receiving emulsion vehicle alone exhibited a moderately severe reaction, while five of seven dogs receiving CSA/alcohol demonstrated immediate, mild reactions. No discernible adverse reactions occurred in any animal receiving CSA/liposomes. Systemic disposition of CSA/alcohol and CSA/liposomes was similar. In contrast to the liposomal vehicle, the emulsion vehicle produced a marked, early weight gain and substantial decrease in tensile strength of the pump tubing, both of which would adversely affect pump function. These results provide the first description of liposomal CSA toxicology and pharmacokinetics in a large animal model and may lead to the successful development of a less toxic parenteral CSA formulation for systemic and local pump-based administration.

Alcohols↗

PubMed1989

The significance of primary nursing.

Primary nursing is a relatively new phenomenon in the organization of ward-based nursing. This paper seeks to answer the question of what lies behind primary nursing's sudden and startling rise in popularity. Factors within nursing which are implicated include most importantly the adoption of the nursing process, and the attempt to provide truly individualized patient care. Nursing's search for professional status has played its part, primary nursing frequently being seen as a key strategy in its achievement. Other areas of wider social change have also had an impact, from the nascent dominance of new right political/social values, to the micropolitical scene within the British National Health Service. While appearing to be the ideal answer to some of nursing's current problems, primary nursing contains some inherent contradictions, most evident being those surrounding the concept of accountability. It may also threaten the cohesiveness of the nursing team on the ward, and may lead to the uncovering of conflicts between doctors and nurses. Finally, perhaps one of the major reasons for its continuing success is the way it brings together the various nursing interest groups and current managerialism in the NHS.

Humans↗

PubMed1987

Mutagenic activity of fluorides in mouse lymphoma cells.

The L5178Y mouse lymphoma cell forward-mutation assay was used to test for the mutagenic activity of sodium and potassium fluoride at the thymidine kinase locus. Mutants were detected by colony formation in soft agar in the presence of trifluorothymidine. Mutagenic and toxic responses were observed in the concentration range of 300-600 micrograms/ml with both sodium and potassium fluoride. Approximately 3-fold increases in mutant frequency were observed for concentrations in the 500-700 micrograms/ml range that reduced the relative total growth to approximately 10% in the absence or presence of a rat-liver S9 activation system. A sample of 30% sodium fluoride-70% sodium bifluoride (NaHF2) induced a similar mutagenic response but was more toxic with respect to the fluoride concentration. A specificity for fluoride ions in causing mutagenesis was indicated by the fast that much higher concentrations of sodium or potassium chloride were necessary to cause toxicity and increases in the mutant frequency. The possible involvement of chromosomal changes was signaled by the predominant increase in the small colony class of mutants.

Animals↗

PubMed1984