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Biomedical subjects

S Lloyd

Publications and source records attributed to S Lloyd.

At least 91 records · Page 5Linked to original sources
PubMed1996

Nurses taking on junior doctors' work: a confusion of accountability.

The number of hospital based posts in which nurses take over clinical work previously done by junior doctors is growing. Accountability for the scope of such new roles and the standards of practice which apply to them are still unclear. When analysed together and compared, the regulations arising from the professional bodies (GMC and UKCC), civil law concerning certain wrongs to patients, and employment law are sometimes contradictory and hard to interpret. The resulting uncertainties about appropriate management for clinical roles evolving between the professions, coupled with an increasingly litigious public, put the nurses and consultants involved at risk of complaints and of disciplinary and legal action. Drawing on our current research into changing clinical roles at the medical-nursing interface, we suggest strategies to reduce risk. Doctors and nurses should be equal partners in planning and managing these new posts, patients should be informed adequately about the nature of the postholder's role and training, significant changes in the work of such postholders should be formally acknowledged by the employer and relevant insurers, individuals taking up new roles should have access to legal advice and support to cover legal risk, and national regulatory bodies need to work together to harmonise their codes of practice in relation to changing clinical roles between the professions.

Humans↗
PubMed1996

Beta-amyloidosis in normal aging and transmitter signaling in human temporal lobe.

Interactions between abnormal amyloid precursor protein metabolism and cholinergic dysfunction are increasingly apparent. Both of these major features of Alzheimer's disease occur in restricted loci in normal aging--a potential model for early Alzheimer type pathology. Entorhinal cortex is particularly vulnerable to beta-amyloidosis and compared with other cortical areas is remarkable for the relatively high density of nicotinic (3H-nicotine) but not other cholinergic or glutamate receptor binding. With increasing age, post-maturity, there is a persistent decline in nicotinic receptor binding in entorhinal cortex whereas muscarinic M1 and non-M1, glutamate NMDA and non-NMDA receptors are spared. Normal elderly individuals, distinguished by the absence of beta A4 immunoreactive plaques in this area, are differentiated from those with plaques by higher nicotine binding. Amongst individuals with an established history of smoking tobacco, nicotinic receptor binding and hippocampal choline acetyltransferase were elevated compared with non-smokers and preliminary evidence indicates a reduced density of cortical plaques. These findings are consistent with the hypothesis that down regulation of the nicotinic cholinergic receptor--a ligand gated calcium channel known to control the expression of neurotrophins--plays a role in the evolution of Alzheimer-type pathology.

Adolescent↗
PubMed1996

Establishing equivalence between scaled measures of quality of life.

In this paper, methodologies which have been used in the pharmaceutical industry to demonstrate the equivalence of drug preparations, are applied to the measurement of quality of life (QOL). This approach is feasible when the generated data are measured on the same scale. Data from the quality of life instruments are transformed into interval scales by means of an appropriate scaling procedure. It is demonstrated that equivalence of QOL instruments is linked by a linear relationship between the QOL instruments Functional Assessment of Cancer Therapy (FACT) and the Functional Living Index-Cancer (FLIC). The linear relationship is derived using orthogonal least squares regression which takes into account that both measures are subject to error.

Activities of Daily Living↗
PubMed1996

Rates of reinfection with Echinococcus granulosus, Taenia hydatigena, taenia ovis and other cestodes in a rural dog population in Uruguay.

A survey was undertaken to determine both the prevalence of, and reinfection rates with Echinococcus granulosus and other cestodes in the Department of Florida, Uruguay. Baseline prevalence was determined in 303 rural dogs which then, in 4 groups, were re-examined 2, 4, 8 or 12 months later. Baseline prevalences for E. granulosus, Taenia hydatigena, Taenia ovis and Dipylidium caninum were 13.2, 13.9, 2.3 and 13.2%, respectively. The frequency distribution of E. granulosus was over-dispersed. Dogs in the population became infected with E. granulosus between 2 and 4 months after treatment (prevalences at 2, 4, 8 and 12 months were 0, 6.8, 18.6 and 27.9%, respectively). There was no indication that there was a predisposition of dogs to infection with the Odds Ratio being 1.0. Dogs were infected with T. hydatigena and D. caninum within 2 months and with T. ovis between 2 and 4 months after treatment. The implications of these different rates of reinfection in the dog population on anthelmintic control strategies against cystic echinococcosis are discussed.

Age Factors↗
PubMed1996

Familial breast cancer: a controlled study of risk perception, psychological morbidity and health beliefs in women attending for genetic counselling.

The present study set out to evaluate perceptions of risk, psychological morbidity and health behaviours in women with a family history of breast cancer who have attended genetic counselling and determine how these differ from general population risk women. Data were collected from 62 genetic counselees (cases) attending the Royal Marsden and Mayday University Hospital genetic counselling services and 62 matched GP attenders (controls). Levels of general psychological morbidity were found to be similar between cases and controls; however, cases reported significantly higher breast cancer-specific distress despite clinic attendance [mean (s.d.) total Impact of Event Scale score, 14.1 (14.3) cases; 2.4 (6.7) controls, P < 0.001]. Although cases perceived themselves to be more susceptible to breast cancer, many women failed correctly to recall risk figures provided by the clinic; 66% could not accurately recall their own lifetime chance. Clinics appeared to have a positive impact on preventive behaviours and cases tended to engage more regularly in breast self-examination (monthly, 66% of cases vs 47% of controls), although few differences were found between groups in terms of health beliefs. We conclude that counselees and GP controls showed considerable similarities on many of the outcome measures, and risk of breast cancer was not predictive of greater psychological morbidity; although cases were more vulnerable to cancer-specific distress. Despite genetic counselling, many cases continued to perceive their risk of breast cancer inaccurately.

Adult↗
PubMed1996

Validation of the functional assessment of multiple sclerosis quality of life instrument.

Based on scientific literature and interviews with clinicians and patients, we developed a quality of life instrument for use with people with MS called the Functional Assessment of Multiple Sclerosis (FAMS). The initial item pool consisted of 88 questions: 28 from the general version of the Functional Assessment of Cancer Therapy quality of life instrument, plus 60 generated by patients, providers, and literature review. The validation samples comprised a mail survey cohort (N = 377) and a clinical cohort (N = 56). Both cohorts provides evidence for internal consistency of the derived subscales, test-retest reliability, content validity, concurrent validity, and construct validity. Principal components and Rasch measurement model analyses were applied sequentially to survey sample data, reducing test length to 44 questions, divided into six subscales: mobility, symptoms, emotional well-being (depression), general contentment, thinking/fatigue, and family/social well-being. Fifteen initially rejected questions were added back as miscellaneous (unscored) questions for their potential clinical and empirical value. The mobility subscale was strongly predictive of the Kurtzke Extended Disability Status Scale and the Scripps Neurologic Rating Scales. The other five subscales were not, indicating they measure aspects of patient quality of life not captured by the neurologic exam. The final 59-item English language instrument (FAMS version 2) is available for inclusion in clinical trials and clinical practice.

Adult↗
PubMed1996

Teething in babies: separating fact from fiction.

In one study, out of 50 babies hospitalised for symptoms attributed to teething, 48 had an organic cause of illness. Symptoms may include a slight rise in temperature, disturbed sleep and feeding, irritability, swollen tender gums and dribbling. Diarrhoea, respiratory symptoms, pulling at the ears, fever or convulsions should not be attributed to teething and require medical attention.

Child, Preschool↗
PubMed1995

The Bristol-Myers Anorexia/Cachexia Recovery Instrument (BACRI): a brief assessment of patients' subjective response to treatment for anorexia/cachexia.

A brief visual analogue instrument was developed and tested in the context of a multicentre randomized double-blinded four-dose trial of megestrol acetate for the treatment of AIDS-related anorexia/cachexia. This nine-item instrument, the Bristol-Myers Anorexia/Cachexia Recovery Instrument (BACRI), was administered every 4 weeks after initiation of study drug (placebo vs 100 mg, 400 mg or 800 mg of drug). The purpose of the instrument was to quantify patient perception of benefit in areas such as decreased concern over weight, decreased concern over appearance, increased pleasure in eating and increase in global perception of quality of life. Post-trial psychometric evaluation of the instrument strongly supported the use of a seven-item index of subjective recovery from symptoms of anorexia/cachexia (BACRI-7) and a single criterion item depicting patient perception of benefit (BACRI-1). The BACRI-7 and BACRI-1 scales showed significant improvement over 12 weeks in patients who received higher dose active drug (400 and 800 mg) compared with the placebo and 100 mg doses. Further differentiation of 400 vs 800 mg arms was seen in the BACRI-7 results, consistent with dose-response improvements in weight and lean body mass changes. Quadratic trends over time in lean body mass change and provider-rated appetite grade suggested peak therapeutic effect at 8 weeks for these endpoints, whereas the absence of these trends in overall weight and patient-reported BACRI scores suggested that these benefits are more persistent. Although subjective (patient-reported) benefit is strongly associated with objective indicators of improvement, there remains the possibility that there is some added, independent benefit of megestrol acetate to subjective well-being.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Transmission dynamics of Echinococcus granulosus, Taenia hydatigena and Taenia ovis in sheep in Uruguay.

A base-line survey was carried out on the transmission dynamics of Echinococcus granulosus, Taenia hydatigena and Taenia ovis in sheep in the Department of Florida, Uruguay. Mean life expectancy at birth of the sheep population in this Department was estimated at 3.5 and 4.8 years for male and female sheep, respectively. Both intensity and prevalence of E. granulosus infection increased with age providing no evidence that immunity was acquired in the population. This revealed that E. granulosus was only relatively stable and in an equilibrium endemic steady state with an estimate of the basic reproduction ratio (Ro) of about 1.2. The mature larval population in sheep was over-dispersed with parameter k, from fitting a negative binomial, being 0.199 and 0.556 in 42- and 54-month-old sheep, respectively. The mean number of cysts increased by 1.05 cysts per year and the infection pressure was calculated as 0.174 infections per year, implying that each infection consisted of 693.6 eggs to produce 6.03 cysts. Neither intensity nor prevalence of infection with T. hydatigena or T. ovis increased with age. This indicated that immunity was acquired to reinfection by both parasites and they were in an equilibrium hyperenedemic steady state with an estimated Ro of 4.2-5.8. Viability and fertility of E. granulosus, and viability of T. hydatigena cysts in the older age groups were low. The effects of the different transmission levels of the parasites on potential control strategies are discussed.

Animals↗
PubMed1995

Patterns of Cryptosporidium antigen and oocyst excretion in calves studied by reverse passive haemagglutination and light microscopy.

A reverse passive haemagglutination (RPH) assay incorporating a monoclonal antibody against Cryptosporidium parvum oocysts was used to follow Cryptosporidium coproantigen excretion by calves. RPH detected soluble antigen that passed 0.22 micron filters. Non-specific reactions that occurred in some samples were markedly reduced by heat treatment of the faecal specimens and were abolished by filtration after heat treatment. Results were compared with oocyst counts performed by microscopy of modified Ziehl-Neelsen (MZN) stained faecal smears. Five hundred and thirty-two daily specimens were examined from 30 calves. The mean age at which positive results for both oocysts and antigen was detected was 9 days (range 5-15 days), and excretion lasted for 5-11 days with some cycling of positive reactions in some calves. The occasional cycling to a negative reaction demonstrates a need to take samples from consecutive days to ensure diagnosis. Two hundred and ninety-one (54.7%) specimens were negative in both tests, 178 (33.5%) were positive in both, 14 (2.6%) were positive only by microscopy, and 49 (9.2%) were positive only by RPH. By these criteria the kappa coefficient of agreement between the tests was good (0.753). Compared with MZN, the sensitivity of RPH is 92.7%, specificity 85.6%, positive predictive value 78.4% and negative predictive value 95.4%. The method is simple, objective, has ease of quality control, and either single samples or batches can be processed.

Aging↗
PubMed1995

Comprehensiveness and bias in reporting clinical trials. Study of reviews of pneumococcal vaccine effectiveness.

PURPOSE: To assess the extent to which relevant controlled clinical trials are cited and summarized in review articles, and to determine whether citation of relevant clinical trails is biased as to study results. DATA SOURCES: Articles were identified by searching MEDLINE and EMBASE databases. STUDY SELECTION: Review articles published between 1986 and 1988 on the clinical effectiveness of pneumococcal vaccine. DATA EXTRACTION: Proportion of relevant clinical trials cited and whether citation is biased by study results. DATA SYNTHESIS: The proportion of relevant primary studies cited per review article ranged from 0% to 36% (mean 9%). The number of trials cited per review ranged from zero to six (mean 1.2). In nine of 17 reviews, no clinical trials were cited. Study populations and outcome(s) were specified and results presented quantitatively for 0 to 27% of relevant trials per review (mean 6%). Unsupportive trials were almost twice as likely to be cited as supportive trials. CONCLUSIONS: Reporting of the results of relevant clinical trials in reviews of pneumococcal vaccine effectiveness is incomplete. Our findings suggest a need for greater scientific rigour in preparing, reviewing, and editing review articles.

Bacterial Vaccines↗
PubMed1995

Expression of E6/E7 or SV40 large T antigen-coding oncogenes in human corneal endothelial cells indicates regulated high-proliferative capacity.

PURPOSE: Human corneal endothelial cells are thought to have limited capacity for proliferation. Little is known about the mechanisms that regulate the proliferation of these cells. The authors introduced oncogenes into human corneal endothelial cells to modulate proliferation. In addition, they sought to establish cell lines to facilitate study of human corneal endothelial cells. METHODS: Early-passage human corneal endothelial cells were transduced with disabled retrovirus (pLXSN16E6/E7) coding for the human papilloma virus type 16 transforming oncoproteins E6 and E7. Early-passage cells were also stably transfected by electroporation with the pMTV-D305 plasmid vector, in which SV40 large T antigen (SV40 LTAg) mRNA expression is positively regulated by the mouse mammary tumor virus promoter. Expression of E6/E7 mRNA or SV40 LTAg mRNA in cell lines was monitored with the polymerase chain reaction. SV40 LTAg protein expression was detected by immunocytology and Western blot analysis. RESULTS: Human corneal endothelial cells were efficiently infected with disabled retrovirus coding for E6/E7, and seven strains of cells have continued active proliferation for more than 50 population doublings (PD) (< 8 control PD). E6/E7 mRNA was expressed by each cell strain. E6/E7 transformed cells proliferate rapidly and form a monolayer of cells with a high degree of contact inhibition. Transfection with pMTV-D305 is less efficient, and only a single strain was developed. pMTV-D305-transfected endothelial cells (dexamethasone induced) proliferated at a lower rate than E6/E7-transduced cells or cells transfected with a vector (pSV3neo) in which SV40 LTAg is constitutively regulated. In the absence of dexamethasone, the proliferation of pMTV-D305-transfected cells was even slower, but cells continued to produce SV40 LTAg mRNA and protein. The latter results indicated that SV40 LTAg mRNA continued to be synthesized at significant levels in pMTV-D305-transfected cells in the absence of the inducer dexamethasone. CONCLUSIONS: This study suggests that human corneal endothelial cells have a high capacity for proliferation. Thus, cell division is normally controlled in human corneal endothelial cells by poorly characterized, but efficient, mechanisms. Because the E6 and E7 proteins, as well as the SV40 large T antigen, specifically bind to and interfere with the activity of the retinoblastoma (RB) and p53 tumor suppressor proteins, our results suggest that these proteins have critical roles in regulating the proliferation of human corneal endothelial cells.

Antigens, Polyomavirus Transforming↗
PubMed1995

Libyostrongylus dentatus n. sp. (Nematoda: Trichostrongylidae) from ostriches in North America, with comments on the genera Libyostrongylus and Paralibyostrongylus.

Libyostrongylus dentatus sp. n. is described from ostriches on farms from North Carolina and Texas. Nematodes were recovered from the posterior proventriculus and under the koilon lining of the gizzard; the parasites occurred in mixed infections with Libyostrongylus douglassii. The species is distinguished from congeners by the presence of a prominent, dorsal, esophageal tooth; in males by the structure of the dorsal ray and spicules; and in females by small eggs (52-62 microns in length), a sublateral vulva situated at 93% of the body length from the anterior, and a strongly curled, digitate, tail with cuticular inflations at the anus. Conflicts in the generic diagnoses of Libyostrongylus and Paralibyostrongylus were apparent, based on the structure of the dorsal ray or position of rays 3-5 of the copulatory bursa. These can only be resolved based on phylogenetic analyses of the 11 nominal species referred to these genera.

Animals↗
PubMed1994

Comparison of the binding of nicotinic agonists to receptors from human and rat cerebral cortex and from chick brain (alpha 4 beta 2) transfected into mouse fibroblasts with ion channel activity.

(-)-Nicotine, cytisine and carbachol evoked 86Rb efflux from mouse fibroblasts stably transfected with alpha 4 beta 2 chick brain nicotinic subunits. This response to (-)-nicotine was inhibited by mecamylamine and dihydro-beta-erythroidine and was mirrored by a rise in intracellular Ca2+ measured by microspectrofluorimetry. Lobeline and isoarecolone methiodide evoked no significant 86Rb from cells and unlike the above agonists displayed significantly different IC50 values for the displacement of [3H]nicotine from mammalian (rat and human cerebral cortex) and transfected fibroblast membranes.

Animals↗