Search PubMed⌕ Search

Biomedical subjects

C Todd

Publications and source records attributed to C Todd.

At least 91 records · Page 5Linked to original sources
PubMed1993

12-hour shifts: job satisfaction of nurses.

A before and after study was carried out amongst staff of 10 wards of a county hospital before and after the introduction of a 12-hour shift system for nurses. The purpose was to investigate the impact of the shift system on job satisfaction. Some 320 nurses covering all qualified and unqualified grades were surveyed using a standard job satisfaction attitude scale. It was found that under the 12-hour shift both intrinsic and extrinsic factors of job satisfaction had been detrimentally affected. Considerable dissatisfaction was expressed about hours of work, conditions of work and the impact of the shift on domestic and social arrangements. The vast majority (83%) reported that they did not want to go on working the shift and there was support for the view that recruitment to nursing would be adversely affected by the shift.

Adult↗
PubMed1993

Technical note: computing tests of fixed effects in a restricted class of mixed models.

Inferences about fixed effects in mixed linear models are important in a variety of animal science studies. The statistical theory for making such inferences is well known, and if the variance components are known up to a proportionality constant, then optimal exact tests can be performed. Computing the test statistics, however, can still be problematic when the random effects have many levels. In practice, approximate tests that are easily computed but less efficient are usually employed. This article describes reduction in error sum of squares procedures for performing the exact test and for computing associated confidence intervals. By taking advantage of iterative algorithms for solving Henderson's mixed-model equations, the tests can be performed without inverting the covariance matrix or computing a generalized inverse of the mixed-model coefficient matrix. The procedures are illustrated on an animal model that has three random effects, two with 1,372 levels and one with 450 levels.

Algorithms↗
PubMed1993

Kabuki make-up syndrome and hearing impairment.

In 1981, Niikawa et al. and Kuroki et al. independently described patients with a new syndrome consisting of mental retardation, postnatal growth deficiency and unusual facial features such as long palpebral fissures with eversion of the lateral one-third of the lower eyelids, arched and laterally sparse eyebrows and large prominent ears among other malformations. The condition has been called Kabuki make-up syndrome because the facial features in affected individuals resemble the make-up of the actors in a Japanese play: Kabuki. After the initial reports on Japanese individuals, the condition has been observed in several other patients of different ethnic origins including a few patients from this country (Kaiser-Kupfer et al., 1986; Pagon et al., 1986). We describe an additional 13-year-old male patient with Kabuki make-up syndrome with possible implication of autosomal dominant inheritance from his mother. Interestingly, our patient also displayed hitherto unreported severe ossicular malformations resulting in significant hearing impairment.

Abnormalities, Multiple↗
PubMed1992

The development and application of automated gridding for efficient screening of yeast and bacterial ordered libraries.

An automated gridding procedure for the inoculation of yeast and bacterial clones in high-density arrays has been developed. A 96-pin inoculating tool compatible with the standard microtiter plate format and an eight-position tablet have been designed to fit the Biomek 1000 programmable robotic workstation (Beckman Instruments). The system is used to inoculate six copies of 80 x 120-mm filters representing a total of approximately 20,000 individual clones in approximately 3 h. High-density arrays of yeast artificial chromosome (YAC) and cosmid clones have been used for rapid large-scale hybridization screens of ordered libraries. In addition, an improved PCR library screening strategy has been developed using strips cut from the high-density arrays to prepare row and column DNA pools for PCR analysis. This strategy eliminates the final hybridization step and allows identification of a single clone by PCR in 2 days. The development of automated gridding technology will have a significant impact on the establishment of fully versatile screening of ordered library resources for genomic studies.

Animals↗
PubMed1992

Retinoic acid receptor expression in human skin keratinocytes and dermal fibroblasts in vitro.

Retinoic acid is essential for the normal differentiation of epithelia but its cellular function is obscure. The expression patterns of retinoic acid receptors (RARs) in skin cell types may give an insight into the role of retinoic acid in skin. We have compared the patterns of RAR expression in human keratinocytes and dermal fibroblasts in vitro, and studied the effects of retinoic acid on RAR expression. RAR-alpha and RAR-gamma were expressed in keratinocytes and fibroblasts: RAR-gamma was expressed at similar levels in both cell types but RAR-alpha was more abundant in fibroblasts. There were no differences in expression of either RAR-alpha or RAR-gamma between stratifying (high-calcium medium) and proliferating (low-calcium medium) keratinocytes and expression of these RARs was unaffected by retinoic acid. RAR-beta was undetectable in keratinocytes. In the majority of fibroblast cell lines, RAR-beta transcripts were either undetectable or expressed at a low level. Retinoic acid at low concentrations (10(-10) to 10(-9) M) rapidly induced the expression of RAR-beta. Cyclic adenosine monophosphate (cAMP) analogues inhibit RAR-beta induction in teratocarcinoma cells. However, dibutyryl-cAMP did not affect RAR-beta induction in fibroblasts. Forskolin, an adenylate cyclase activator, and the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine (IBMX) decreased constitutive RAR-beta mRNA levels but did not block induction of RAR-beta by retinoic acid. Since intracellular cAMP levels were only increased detectably in response to forskolin, the reduction in constitutive levels of RAR-beta mRNA may be mediated by mechanisms other than via cAMP.

Carrier Proteins↗
PubMed1991

Educational activities on wards under 12 hour shifts.

Interest in 12 hour nursing shifts has renewed in response to demands for improved cost effectiveness in the NHS. But the effects of the shift on nursing education are unclear. A repeated measures study was conducted, using activity analysis to record patterns of nursing and educational behaviour under a 12 hour as compared to an 8 hour shift. Lower levels of ward based education occur under the 12 hour shift. Students pair up with trained staff less. Rather they work alone or with other students more. They also have less contact with patients than under an 8 hour shift.

Attitude of Health Personnel↗
PubMed1991

Safety and immunogenicity of hydrogen peroxide-inactivated pertussis toxoid in 18-month-old children.

The immunogenicity and adverse effects of an acellular pertussis vaccine consisting of a purified pertussis toxin inactivated with hydrogen peroxide (PTxd) was evaluated. Children aged 15 to 30 months were injected with 10 (n = 33) or 50 micrograms (n = 34) of PTxd or with diphtheria and tetanus toxoids and whole cell pertussis vaccine (DTP) (n = 34). All children had previously received three doses of DTP during infancy. Both dosages of PTxd induced higher IgG antibody (p less than 0.05 for 10 micrograms dose and p less than 0.01 for 50 micrograms dose) and pertussis antitoxin responses (p less than 0.01 for 50 micrograms dose) than DTP. The 50 micrograms dose gave slightly higher (though not significantly) antibody responses than the 10 micrograms dose of PTxd. None of the vaccines induced detectable IgM or IgA antibody responses to pertussis toxin. At 24 h, local reactions occurred in none of the children injected with 10 micrograms PTxd, 12% with 50 micrograms PTxd and 78% with DTP. Fever at 24 h occurred in 13% after 10 micrograms PTxd, in none after 50 micrograms PTxd and in 53% after DTP. Recipients of DTP, but not of PTxd, had significant increases in neutrophils and decreases in lymphocytes and haematocrit at 24 h (all p less than 0.05). None of the groups showed changes in blood glucose at 24 h. PTxd induced pertussis toxin antibody levels similar to those observed in patients convalescing from natural pertussis. This acellular pertussis vaccine deserves further evaluation for safety and immunogenicity in infants and for efficacy in preventing pertussis.

Antibodies, Viral↗
PubMed1991

Metastatic squamous carcinoma in the neck: an anatomical and physiological study using CT and SPECT 99Tcm (V) DMSA.

Technetium-99m (99Tcm) (V) dimercaptosuccinic acid (DMSA) is a new tumour imaging agent that has been used to image squamous cell carcinoma (SCC) of the head and neck. This study has been undertaken to compare clinical examination with computed tomography (CT) (anatomical) and SPECT 99Tcm (V) DMSA (physiological) imaging in the evaluation of metastatic SCC of the neck. Twenty-five patients with head and neck cancer were studied. Computed tomography was as sensitive but more accurate than clinical examination in predicting the presence of cancer. SPECT 99Tcm (V) DMSA was inferior to both techniques in identifying metastatic disease. There is no role for SPECT 99Tcm (V) DMSA imaging in the management of patients with SCC metastatic to the neck. Combined imaging with CT offered no advantages over anatomical imaging with CT alone. There is no role for CT in the routine evaluation of the clinically N0 neck and the role of CT of the neck in the management of patients with metastatic SCC is discussed.

Adult↗
PubMed1990

The biological activity of retinoids in melanoma cells. Induction of expression of retinoic acid receptor-beta by retinoic acid in S91 melanoma cells.

The expression of mRNA for retinoic acid receptor beta (RAR-beta) was induced by all trans-retinoic acid in murine S91 melanoma cells. The induction of RAR-beta was dose-dependent, rapid and insensitive to cycloheximide. Both 13-cis-retinoic acid and 3,4-didehydro-all trans-retinoic acid also induced expression of RAR-beta but were only effective at concentrations 100-fold greater than all trans-retinoic acid. The expression of RAR-alpha and RAR-gamma was unaffected by retinoic acid.

Animals↗
PubMed1990

Food store accessibility.

Although occupational therapists try to help their wheelchair-bound clients reenter the community or maintain independence, many facilities' noncompliance with accessibility standards makes such planning difficult. In the present study, a survey was used to investigate the wheelchair accessibility of 20 grocery and convenience stores. The results of the survey indicated that types of stores with greatest accessibility, in descending order, were (a) rural grocery stores, (b) urban grocery stores, (c) urban convenience stores, and (d) rural convenience stores. No overall differences were found between the urban and rural stores. The types of deficiencies found and their effects on clients' shopping are described. A follow-up study was conducted to see if the store managers, who were sent letters notifying them of their stores' deficiencies, would correct these problems. Six months after notification, the survey was repeated. Five of the 20 managers made changes in specific deficient areas, whereas the remaining 15 made no changes. The survey results and the fact that 25% of the stores made changes after receipt of a letter indicate that occupational therapists can be effective advocates for accessibility and thus provide a vital link to productive living for persons in wheelchairs.

Activities of Daily Living↗
PubMed1990

Du phenotyping by the rosette technique when the direct antiglobulin test is positive.

The rosette technique provides a simple rapid and accurate procedure for Du phenotyping of red blood cells (RBCs) with a positive direct antiglobulin test (DAT) due to antibodies other than those of the Rh system. We used Sebring and Polesky's rosette technique to test RBCs with positive DATs. Characteristic microscopic agglutination was observed for the Du phenotype which was different from the mixed-field agglutination seen as positive rosettes in feto-maternal hemorrhage (FMH). The microscopic "starry-sky" pattern typical for FMH-positive rosettes is easily differentiated from the uniform agglutination produced by the D phenotype. The rosette technique was performed on 202 Rh negative cord RBCs out of 4815 cord cells with a positive DAT. Parallel testing for Du by the chloroquine elution and antihuman globulin (AHG) test was done on 67 of the 202 cases. Four Du RBCs that were identified by the rosette technique were confirmed by the chloroquine Du technique The rosette technique proved to be time saving and as sensitive as the routinely performed elution technique for removal of antibodies followed by the AHG Du test.

Journal Article↗
PubMed1990

[Dipyridamole-thallium 201 tomography following acute myocardial infarct: significance for stratifying cardiac risk factors].

For the purpose of risk stratification 80 consecutive patients (mean age 58 +/- 7) with a chest pain syndrome after documented myocardial infarction underwent tomographic vasodilation-redistribution thallium-201 perfusion imaging, using 0.56 mg/kg intravenous dipyridamole. Tomograms were analyzed for size and location of reversible and fixed perfusion defects and correlated to angiographic characteristics, left ventricular ejection fraction and wall motion, collateral status, and 1-year prognosis as measured by cardiac events within 14 +/- 3 months. No serious side effects were noted with the diagnostic use of intravenous dipyridamole. According to the perfusion pattern three subgroups of post-infarction patients were identified: 1) by ischemia at a distance with redistribution in non-infarct related territories (n = 48), 2) by peri-infarctional ischemia with redistribution in the territory of the "infarct artery" (n = 9), and 3) by exclusively fixed defects without redistribution (n = 23). Ischemia at a distance was associated with a larger reversible defect than peri-infarctional ischemia (p less than 0.05) and the pattern without redistribution (p less than 0.005); the fixed defect size, however, was similar in all three subgroups. In addition, the severity of coronary artery disease (Gensini score and number of diseased vessels) and the degree of collateralization was higher in presence of a redistribution pattern (p less than 0.05), although no significant differences in global and regional function were noted as a function of thallium-201 redistribution.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

The quality of nursing care on wards working eight and twelve hour shifts: a repeated measures study using the MONITOR index of quality of care.

Interest in 12 hr nursing shifts has renewed in response to demands for improved cost effectiveness in the NHS, but the effects of this shift on patient care are unclear. A repeated measures study of 10 wards comparing quality of care, measured by MONITOR, under 8 and 12 hr shifts was conducted. The overall MONITOR scores were significantly lower under the 12 hr shift, with planning, non-physical care and evaluation of care scales showing significant decreases. The pattern of results when data were analysed by patient dependency levels reveals that whilst the quality of care overall for the four dependency categories was significantly poorer under the 12 hr shift, the lower dependency categories were less adversely affected in terms of physical and non-physical care delivered.

Humans↗
PubMed1988

The effects of retinoic acid on rat epidermal cells in vitro: changes in patterns of protein phosphorylation in relation to growth and differentiation.

Keratinocytes proliferate, stratify, and differentiate in vitro but if the calcium concentration of the medium is reduced to 0.07 mM Ca2+ (low calcium medium) the cells proliferate but do not stratify or differentiate. Keratinocytes proliferating in low calcium medium synthesized DNA at a higher rate than cultures of stratifying keratinocytes and this correlated with increased phosphorylation of a membrane-associated Mr 23,200 phosphoprotein (pp23) relative to cytosolic phosphoproteins of Mr 26,500 (pp27a and pp27b). In both normal and low calcium medium, all-trans-retinoic acid increased phosphorylation of pp23 relative to that of pp27 and increased DNA synthesis after 12-24 h. These results suggest that the phosphoproteins pp23 and pp27 are cell-cycle regulated and that the changes in phosphorylation were a consequence of a stimulation of cell proliferation by retinoic acid. The half-life of all-trans-retinoic acid in these cultures was about 6 h; increased DNA synthesis and concomitant changes in phosphorylation patterns also resulted from a 6-h pulse of retinoic acid followed by an 18-h washout period.

Animals↗
PubMed1988

A numerical classification of the genus Bacillus.

Three hundred and sixty-eight strains of aerobic, endospore-forming bacteria which included type and reference cultures of Bacillus and environmental isolates were studied. Overall similarities of these strains for 118 unit characters were determined by the SSM, SJ and DP coefficients and clustering achieved using the UPGMA algorithm. Test error was within acceptable limits. Six cluster-groups were defined at 70% SSM, which corresponded to 69% SP and 48-57% SJ. Groupings obtained with the three coefficients were generally similar but there were some changes in the definition and membership of cluster-groups and clusters, particularly with the SJ coefficient. The Bacillus strains were distributed among 31 major (4 or more strains), 18 minor (2 or 3 strains) and 30 single-member clusters at the 83% SSM level. Most of these clusters can be regarded as taxospecies. The heterogeneity of several species, including Bacillus brevis, B. circulans, B. coagulans, B. megateriun, B. sphaericus and B. stearothermophilus, has been indicated and the species status of several taxa of hitherto uncertain validity confirmed. Thus on the basis of the numerical phenetic and appropriate (published) molecular genetic data, it is proposed that the following names be recognized; Bacillus flexus (Batchelor) nom. rev., Bacillus fusiformis (Smith et al.) comb. nov., Bacillus kaustophilus (Prickett) nom. rev., Bacillus psychrosaccharolyticus (Larkin & Stokes) nom. rev. and Bacillus simplex (Gottheil) nom. rev. Other phenetically well-defined taxospecies included 'B. aneurinolyticus', 'B. apiarius', 'B. cascainensis', 'B. thiaminolyticus' and three clusters of environmental isolates related to B. firmus and previously described as 'B. firmus-B. lentus intermediates'. Future developments in the light of the numerical phenetic data are discussed.

Bacillus↗
PubMed1986

Differences between terminally ill patients who know, and those who do not know, that they are dying.

Four GPs each selected 6 patients, 2 terminally ill with knowledge of diagnosis and prognosis, 2 terminally ill without knowledge, and 2 chronically ill. Semi-structured interviews were conducted with the patients, and the transcripts' content was analyzed. There were large group differences in the predicted direction in frequency of utterances that indicated knowledge, which both validated the content analysis and verified the GPs' capacity to categorize patients according to knowledge. Terminally ill patients with knowledge produced significantly longer transcripts than the other two groups. Groups did not differ significantly on state or trait anxiety scales. Differences due to demographic variables could not account for the main effects. There were significant associations that involved age, anxiety, and the dependent variables of the content analysis, especially among the terminally ill patients without knowledge.

Age Factors↗
PubMed1982

Numerical and chemical classification of Nocardia amarae.

Twenty-one strains of Nocardia amarae and marker cultures of Mycobacterium, Nocardia, Rhodococcus and the 'aurantiaca' taxon were subjected to numerical phenetic analyses using 92 unit characters. The data were examined using the simple matching (SSM), Jaccard (SJ) and pattern (DP) coefficients and clustering was achieved using the unweighted average linkage algorithm. Neither cluster nor aggregate cluster composition was markedly affected by the coefficient used or by test error, estimated at 1.5%. The N. amarae strains formed a distinct and homogeneous cluster which showed its highest similarity to phena equated with Nocardia asteroides, Nocardia brasiliensis and Nocardia otitidis-caviarum. The non-hydroxylated fatty acid composition and overall size of the mycolic acids was similar to that found to be characteristic of Nocardia sensu stricto, though the long-chain in the 2-position of the mycolic acids was relatively much richer in monounsaturated components. Nocardia amarae, in containing dihydrogenated menaquinones with nine isoprene units, is clearly distinguished from established representatives of Nocardia.

Fatty Acids↗