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Biomedical subjects

S Todd

Publications and source records attributed to S Todd.

At least 37 records · Page 2Linked to original sources
PubMed2000

Strategic planning and progress under the All Wales Strategy: reflecting the perceptions of stakeholders.

Nominated representatives from the various stakeholder interests, i.e. social services, health, education, voluntary organizations, parent groups and self-advocacy groups, involved in the implementation of the All Wales Strategy for the development of services for people with intellectual disability were interviewed 2 years after the end of the initial 10-year phase. Interviewees were asked to reflect on the strengths and weaknesses of policy implementation, including: changing priorities, planning arrangements, agency roles, central guidance and financial mechanisms, consumer participation, and the impact of more recent policy or structural developments. Despite recognition of the leadership of the Welsh Office, the shift in thinking achieved, the developments made in joint agency collaboration and in consumer participation in planning, and an increasing competence to plan effectively over time, the overriding perception was that more could have been made of the opportunity afforded by the clearest and best resourced central government policy within the UK in this area. At the heart of this judgement lay concerns about pragmatic rather than strategic planning, a failure to link annual service developments to a final comprehensive end point and a related failure to integrate planning to meet community needs with hospital resettlement Factors which may have contributed to these weaknesses are discussed, as are lessons for subsequent community care policy.

Community Health Planning↗
PubMed2000

Working in the public and private domains: staff management of community activities for and the identities of people with intellectual disability.

In addition to describing how the concept of stigma continues to be a pervasive influence in encounters between people with intellectual disability and others, the present study suggests that the management of this situation has passed into the control of care staff. An ethnographic study of young adults and community relationships suggests that the activities of staff are crucial in shaping the social profile of people with intellectual disability. The views of care staff about the taken-for-granted rights which characterize presence and participation in the community domain encourage them to adopt a semi-insulation approach to their work. Staff extend this approach by adopting information control strategies to conceal important information from students. The present author argues that there is a need for on-going research into staff activity in the community domain.

Adult↗
PubMed2000

New onset atrial flutter termination by overdrive transoesophageal pacing: effects of different protocols of stimulation.

AIM: We evaluated the effect of different stimulation protocols on atrial flutter interruption by transoesophageal pacing. METHODS AND RESULTS: Eighty patients with new onset atrial flutter were randomized into four groups. Pacing was attempted under the following conditions: with short bursts (5 s), without treatment (group A) and after oral administration of propafenone 600 mg (group B); with prolonged bursts (30 s), without treatment (group C) and after oral administration of propafenone 600 mg (group D). Pacing interrupted atrial flutter in 20% of patients in A, 55% in B, 50% in C and 85% in D. The use of longer bursts gave better results both in patients without treatment (P < 0.05: C vs A) and in patients with propafenone (P < 0.05: D vs B). Comparing groups with the same stimulation protocol, we observed a better response in patients treated with propafenone (P < 0.05: B vs A and D vs C). In the groups without treatment the use of shorter bursts was associated with a lower induction of stable atrial fibrillation (three vs nine episodes), in the groups on propafenone no differences were observed (one vs one episode). CONCLUSIONS: We conclude that the association of propafenone with long bursts gives the best result for interruption of new onset atrial flutter by transoesophageal pacing.

Administration, Oral↗
PubMed1999

Dietary antioxidant vitamins and fiber in the etiology of cardiovascular disease and all-causes mortality: results from the Scottish Heart Health Study.

In this paper, data obtained between 1984 and 1993 from 11,629 men and women as part of the Scottish Heart Health Study (Scotland, United Kingdom) were used to investigate the relation between antioxidant vitamin and fiber intakes and both incident coronary heart disease (CHD) (649 events) and all-causes mortality (591 deaths). All age-adjusted mean intakes tended to be higher in the group that experienced no event. For men, increased fiber intake was associated with decreased risk of CHD even after adjustment for a host of other major coronary risk factors; hazard ratios relative to the lowest quarter were 0.68, 0.70, and 0.64 by increasing quarter. This relation was also observed for mortality (hazard ratios of 0.62, 0.66, and 0.62). Evidence was found that higher intakes of the antioxidants were also beneficial, although the associations were weaker. For women, fiber was the only obviously influential dietary factor, with hazard ratios of 0.94, 0.60, and 0.56 for CHD and 1.25, 0.82, and 0.65 for mortality. These results suggest that the current public health drive to increase the consumption of foods rich in antioxidant vitamins and (particularly) fiber will impact on both CHD risk and the general health of the population.

Adult↗
PubMed1999

Colostrum intake by dairy calves.

AIMS: To determine which clinical parameters could be used to identify calves with low serum immunoglobulin levels and to examine the influence of cow and calf behaviour on colostrum intake. METHODS: Blood samples were taken from 74 dairy calves after they were separated from their dams, and analysed for serum gamma glutamyltransferase (GGT) activity. Physical and behavioural measurements were taken for 57 of these calves at this time. The behaviour of 2 1 dairy cows and their calves was observed between birth and the time the calves were separated when a blood sample was taken from 17 of them and analysed for GGT. RESULTS: Low serum GGT activities (below 200 U/l GGT), indicating low serum immunoglobulin levels, were found in 45% of the group of 74 calves. The calves which had not received colostrum were not easy to distinguish from those that had on the basis of physical or behavioural features. The amount of time that the 2 1 calves spent with their dams before being separated ranged from 1.2 to 24.9 hours. Thirty-three per cent of these calves had not sucked within this time. Of the calves that did suck, 79% did so within 6 hours of birth. CONCLUSIONS: About one half of New Zealand dairy calves may not receive colostrum from their dams even when they are together for up to 24 hours. Most calves that are going to suck of their own accord will do so within 6 hours of birth. CLINICAL SIGNIFICANCE: Dairy calves should be removed from their dams after 6 hours and fed colostrum to guarantee that they receive sufficient immunoglobulins.

Journal Article↗
PubMed1998

Effect of sample volume location on Doppler-derived transmitral inflow velocity values in 288 normal subjects 20 to 80 years old: an echocardiographic, two-dimensional color Doppler cooperative study.

The aims of the study were to evaluate in a population of 288 normal subjects 20 to 80 years old (1) the normal values of the indexes of the mitral flow velocity pattern measured either at the tips of the mitral leaflets or at the annulus; (2) whether there was a significant difference between the values obtained at the tips compared with those measured at the mitral annulus; (3) the correlation with aging between the indexes measured in the two different positions; and (4) whether certain physiological variables have different effects on diastolic function measured in the two different positions. The highest values were always measured at the tips of the mitral leaflets (p < 0.05); only atrial filling fraction, E acceleration time, and E deceleration velocity had higher values when measured at the level of the annulus (p < 0.05). The A-wave peak velocity had the same mean value when measured at both the tips and at the annulus. A significant difference in the correlation between parameters measured at the tips of the mitral leaflets with age and at the annulus (with age) was observed for the following parameters: (1) peak E velocity, E integral, total integral and E acceleration showed better correlation with age when measured at the annulus (p < 0.02); (2) peak A velocity and A integral showed better correlation with age when measured at the tips of the mitral leaflets (p < 0.001). Multivariate analysis showed that age was the variable that had the most influence on diastolic function parameters; heart rate had less influence on the diastolic function indexes.

Adult↗
PubMed1998

Mental health attrition from Air Force basic military training.

The Department of Defense invests considerable money in recruiting and training new military recruits who are discharged for mental health reasons before completing their first enlistment, often within the first 6 months of active duty. The purpose of this study was to provide a description of 1,138 Air Force recruits referred for a mental health evaluation while in basic military training. Variables examined include dispositions, demographic features, diagnoses, mental health history, and attitude and motivation characteristics. Findings show that trainees recommended for discharge often had a history of depression, expressed a lack of motivation to continue in the military, were reporting suicidal ideation, and typically had withheld information on their mental health history during their Military Entrance Processing Station processing. The results are discussed in terms of potential strategies for reducing mental health attrition in Air Force basic military training.

Adult↗
PubMed1997

Incorporation of sequential trials into a fixed effects meta-analysis.

The technique of meta-analysis provides a systematic and quantitative approach to the summary of results from a collection of similar randomized studies. Comprehensive methodology exists for analysis when all trials are of a fixed sample size design, but this is based on assumptions which are no longer valid when incorporating sequentially designed studies. In this paper the effect of incorporating one or more sequential trials into a meta-analysis otherwise consisting of fixed sample size trials is investigated. The results from simulation studies of a variety of plausible scenarios are presented. The aim is to quantify the extent to which bias is introduced. It was found that when incorporating two alternative sequential designs, the triangular test and the O'Brien and Fleming procedure, the results of a conventional meta-analysis remain accurate.

Bias↗
PubMed1997

Homozygous deletions of human chromosome 3p in lung tumors.

Cytogenetic and loss of heterozygosity (LOH) studies have demonstrated that deletions of chromosome 3p occur at a high frequency in all forms of lung cancer. To clarify the role of 3p in lung tumorigenesis and to more precisely identify targets for positional cloning efforts, we have performed 3p deletion analyses (microsatellite and fluorescence in situ hybridization) in a series of lung cancer cell lines and uncultured tumor samples. Importantly, we identified homozygous deletions in four uncultured tumors and one cell line. Homozygous deletions were found in three squamous tumors within a region of 3p21 which had previously been described only in cell lines, a 1-2-megabase homozygous deletion in a small cell tumor at 3p12, and a 3p14.2 homozygous deletion in a non-small cell lung carcinoma cell line. The detection of homozygous deletions affecting these multiple regions in uncultured tumor cells substantiates the belief (previously based on deletions found only in tumor cell lines) that these sites contain important tumor suppressor genes. Along with previously reported homozygous deletions in a distal portion of 3p21.3, we now have evidence for four separate regions of 3p which undergo homozygous deletions in either uncultured lung tumors or cell lines.

Carcinoma, Small Cell↗
PubMed1997

Translation and replication properties of the human rhinovirus genome in vivo and in vitro.

The poor translation efficiency of genome-length human rhinovirus RNA in vitro using HeLa cell extract-supplemented rabbit reticulocyte lysate has hampered the study of rhinovirus IRES-mediated translation and polyprotein synthesis in a cell-free system. In contrast, the efficient in vitro translation characteristics of poliovirus RNAs have ultimately allowed the programming of cell-free coupled translation/replication extracts which are able to produce infectious poliovirus particles in vitro. A possible explanation for the decreased burst size observed during the course of a rhinovirus infection, compared to poliovirus infection, is reduced levels of polyprotein synthesis in vivo. In order to test this hypothesis and extend in vitro translation/replication technology to the study of human rhinoviruses, a chimeric cDNA construct was engineered which allowed the in vitro synthesis of T7 transcripts containing the intact poliovirus type 1 (PV1) 5' noncoding region (5' NCR) and initiation codon upstream of the human rhinovirus 14 (HRV14) polyprotein-coding region and 3'-terminal sequences. These chimeric RNAs translated efficiently in vitro and were used successfully to program a cell-free replication extract. Unexpectedly, parental HRV14 RNAs also translated efficiently in the HeLa cell-free translation/replication extract but replicated less efficiently than the chimera in vitro. The chimeric HRV14/PV1 RNAs were infectious and gave rise to a virus with a growth phenotype similar to that of parental HRV14. Preliminary characterization of this chimeric virus suggests that the biological properties characteristic of rhinovirus in vivo are determined primarily by the rhinovirus gene products. Although the translation efficiency of the HRV14 5' NCR may be a limitation in rabbit reticulocyte lysate-based in vitro translation extracts, it does not appear to be a major limiting determinant for growth of rhinovirus in vivo or replication in the HeLa cell-free extract.

Animals↗
PubMed1997

Chromosome 3p14 homozygous deletions and sequence analysis of FRA3B.

Loss of heterozygosity (LOH) involving 3p occurs in many carcinomas but is complicated by the identification of four distinct homozygous deletion regions. One putative target, 3p14.2, contains the common fragile site, FRA3B, a hereditary renal carcinoma-associated 3;8 translocation and the candidate tumor suppressor gene, FHIT. Using a approximately 300 kb comsid/lambda contig, we identified homozygous deletions in cervix, breast, lung and colorectal carcinoma cell lines. The smallest deletion (CC19) was shown not to involve FHIT coding exons and no DNA sequence alterations were present in the transcript. We also detected discontinuous deletions as well as deletions in non-tumor DNAs, suggesting that FHIT is not a selective target. Further, we demonstrate that some reported FHIT aberrations represent normal splicing variation. DNA sequence analysis of 110 kb demonstrated that the region is high in A-T content, LINEs and MER repeats, whereas Alu elements are reduced. We note an intriguing similarity in repeat sequence composition between FRA3B and a 152 kb segment from the Fragile-X region. We also identified similarity between a FRA3B segment and a small polydispersed circular DNA. In contrast to the selective loss of a tumor suppressor gene, we propose an alternative hypothesis, that some putative targets including FRA3B may undergo loss as a consequence of genomic instability. This instability is not due to DNA mismatch repair deficiency, but may correlate in part with p53 inactivation.

Acid Anhydride Hydrolases↗
PubMed1997

Pulmonary venous flow velocity patterns in 143 normal subjects aged 20 to 80 years old. An echo 2D colour Doppler cooperative study.

In order to find out the normal values and to evaluate the effects of age, heart rate, sex, and haemodynamic and standard echocardiographic parameters on pulmonary venous flow velocity obtained by the transthoracic approach. Doppler pulmonary venous flow parameters were measured in 143 healthy subjects aged from 20 to 80 years. Doppler pulmonary venous flow parameters which had the best correlation with age were: the peak velocity of the systolic wave (r = 0.39) and its integral (r = 0.5), the peak velocity of the diastolic wave (r = -0.6) and its integral (r = -0.44); the systolic (r = 0.68) and diastolic fractions (r = -0.68); the systolic/diastolic peak velocity ratio (r = 0.73) and the systolic/diastolic integral ratio (r = 0.7). The atrial reversal wave did not correlate with age; the atrial reversal wave was more difficult and probably less reliable to measure than the systolic and diastolic waves. The correlations of pulmonary venous flow parameters with mitral flow parameters were also examined. This study showed that, in healthy subjects, despite an increase in the early and atrial waves from the annulus to the tips of the mitral leaflets, there is a similar association between pulmonary venous flow and mitral flow measured at the annulus or at the tips of the mitral leaflets. The intra-observer reproducibility of all the pulmonary venous flow parameters considered were found to be excellent. Moderate inter-observer variability was observed for the systolic, diastolic and atrial reversal wave peak velocities and integrals; however, the systolic/diastolic ratio improved the precision of the measurements. Multivariate analysis showed that age is the principal determinant of the Doppler parameters of pulmonary venous flow: heart rate, sex, body surface area, the size of the left atrium in systole and the left ventricular ejection fraction all influence the Doppler parameters of pulmonary venous flow, even if only slightly.

Adult↗
PubMed1997

Parental work: an account of the day-to-day activities of parents of adults with learning disabilities.

The parental role can be an enduring one for many people with sons or daughters with learning disabilities. Despite this, there has been little research on parents' experiences during their offspring's adult years. The present paper examines the different dimensions of work undertaken by parents in the care of their adult offspring and how they felt these had changed over the years. The paper also explores how parents seek to combine parental work with other aspects of their lives. Data for this study were derived from a qualitative, in-depth study of the experiences of parents of 33 co-resident adult offspring with learning disabilities. The data suggest that the long-term nature of parenting involves both stability and change. For example, some parents had experienced a depletion of physical resources and enthusiasm that made it difficult for them to carry out some aspects of parental work. Parents had also met new difficulties, such as the handling of the disclosure of learning disability to their offspring, as well as to members of the public. For all parents, parenting had remained an extensive involvement, so that they still found it difficult to meet the demands of parenting, and their own non-parental tasks and interests. The data also indicate that service intervention needs to be based on an appreciation of the temporal and personal difficulties in parents' lives, and that service intervention can add to the perceived burden of carers without such an appreciation.

Adolescent↗
PubMed1997

Replication-competent picornaviruses with complete genomic RNA 3' noncoding region deletions.

The genomic RNA 3' noncoding region is believed to be a major cis-acting molecular genetic determinant for regulating picornavirus negative-strand RNA synthesis by promoting replication complex recognition. We report the replication of two picornavirus RNAs harboring complete deletions of the genomic RNA 3' noncoding regions. Our results suggest that while specific 3'-terminal RNA sequences and/or secondary structures may have evolved to promote or regulate negative-strand RNA synthesis, the basic mechanism of replication initiation is not strictly template specific and may rely primarily upon the proximity of newly translated viral replication proteins to the 3' terminus of template RNAs within tight membranous replication complexes.

Gene Expression Regulation, Viral↗
PubMed1997

Speech intelligibility of children with multichannel cochlear implants.

The purpose of this longitudinal study is to document improvements in speech intelligibility in children who have received multichannel cochlear implants, to compare their performance to that of a matched group of children with different levels of hearing loss who use conventional hearing aids. Speech intelligibility was measured by panels of listeners who analyzed recorded speech samples preimplant and at 6-month intervals following implantation. The results of this study demonstrate that prelingually deafened children with the Nucleus multichannel cochlear implant achieved significant improvements in speech intelligibility. By the 4.5- to 7.5-year intervals, the speech intelligibility exceeded 40%.

Child↗
PubMed1997

Comparative evaluation of Wellhöfer ion chamber array and Scanditronix diode array for dynamic wedge dosimetry.

Normalised profiles have been measured using the Scanditronix diode array and the Wellhöfer ion chamber array for the Varian dynamic wedge. Agreement was of the order of 0.1% of central axis peak dose for an open beam at depth, 0.3% for a dynamic wedge field at depth, and up to 0.6% at the peak depth. The use of the arrays for data acquisition is discussed, including user interface limitations. Data reproducibility is determined to be of the order of 0.1% for both systems. The issue of beam hardening within dynamic wedges is discussed and resolved in terms of the dose-gradient effect. A method for interpolation between dynamic wedge profiles using open beam data is presented that allows construction of isodoses to an estimated accuracy of 0.7%. Finally a benchmark for comparison of different measuring systems based on quality assurance requirements for the enhanced dynamic wedge is suggested.

Particle Accelerators↗
PubMed1996

The effect of IL-2 treatment on transcriptional attenuation in proto-oncogenes pim-1 and c-myb in human thymic blast cells.

IL-2 is the major mitogenic cytokine for mature human T cells. This growth factor has been shown previously to induce the expression of a number of genes, including structural proteins, proto-oncogenes, and metabolic enzymes. Multiple mechanisms, including increases in mRNA stability, protein synthesis, and new transcriptional initiation, have been studied to determine how IL-2 induces such a wide variety of genes. The following studies show that a release of transcriptional attenuation is important in IL-2-induced gene expression. A thymic blast cell system was developed and used to demonstrate that IL-2-deprived cells have a marked attenuation of transcription in the 3' ends of the pim-1 and c-myb genes. IL-2 stimulation removes this attenuation and leads to read-through transcription. This effect is gene-specific, as demonstrated by the fact that GAPDH is not attenuated in unstimulated cells. The IL-2-mediated relief of attenuation occurs within 1 h of IL-2 stimulation and is insensitive to the translation inhibitor cycloheximide, suggesting that new protein synthesis is not necessary. Further, the effect is insensitive to the immunosuppressant cyclosporin A, but is sensitive to rapamycin and the tyrosine kinase inhibitor genistein. These studies demonstrate that release of transcription attenuation is a mechanism used to induce gene expression in response to IL-2 treatment.

Cells, Cultured↗