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Biomedical subjects

R Williamson

Publications and source records attributed to R Williamson.

At least 19 recordsLinked to original sources

The care home activity project: does introducing an occupational therapy programme reduce depression in care homes?

The primary aim of the study was to test the hypothesis that depression severity in care homes for older people would be reduced by an occupational therapy programme. This was a feasibility study for a cluster randomised controlled trial and involved four intervention and four control homes in northern England. In each intervention home a registered occupational therapist worked full-time for one year delivering an individualised programme to participants. Pre- and post-intervention data for the Geriatric Mental State-Depression Scale (primary outcome measure) were obtained for 143 participants. Secondary outcomes included dependency and quality of life. No significant intervention effects were found in any of the quantitative outcome measures, though qualitative interviews showed the intervention was valued by many participants, staff and relatives. Therapist ratings and qualitative interviews suggested that the intervention was beneficial to some participants but no distinctive characteristics were found that might enable prediction of likely benefit on initial assessment. This exploratory study provides no evidence that this intervention produced benefits in terms of depression, dependency or quality of life. Lack of prior power calculations means these are not definitive findings; but numbers were sufficient to perform the required analyses and data did not suggest effects that would have reached statistical significance with a larger sample. This study highlights issues for consideration in providing such services in care homes.

Aged↗

Is the L-tryptophan metabolite quinolinic acid responsible for eosinophilic fasciitis?

The eosinophilia-myalgia syndrome is accompanied by alterations in L-tryptophan metabolism with elevated levels of L-kynurenine and quinolinic acid having been recorded. It has been suggested that this is due to activation of indoleamine 2,3-dioxygenase by interferon-gamma. It is unknown whether these products of tryptophan metabolism play a role in the pathogenesis of this syndrome and the closely related condition of eosinophilic fasciitis. To explore this possibility, the principal author (RN) received a series of subcutaneous injections of quinolinic acid. A total of 1200 mg was administered over a 1-month period. Peripheral blood eosinophil counts were monitored and biopsies taken for H&E and immunohistochemical stains. Over the 1-month period the eosinophil count rose from 0.3x10(9)/l to 0.8x10(9)/l before falling to 0.4x10(9)/l approximately 5 weeks later. H&E sections showed a mixed infiltrate of eosinophils and neutrophils extending through the reticular dermis and septa of the panniculus. No deep fascia was obtained on biopsy. The immunohistochemical stain for transforming growth factor beta 1 showed staining of endothelial cells and dendritic cells. The interleukin-5 stain was negative. Our results suggest that quinolinic acid may play a role in cutaneous eosinophilic disorders.

Eosinophilia↗

Stem cells for the treatment of liver disease.

Stem cells tantalise. They alone have the capacity to divide exponentially, recreate the stem cell compartment as well as create differentiated cells to build tissues. They should be the natural candidates to provide a renewable source of cells for transplantation. Does the reality support the promise of this exciting alternative to conventional therapies for metabolic and degenerative liver disease? Can techniques be developed to provide the large number of cells that could be required? Must there be "space" in the liver to accept the cells? To what extent is the liver immunoprivileged, and is immunosuppression necessary for stem cell therapy? Is it better to use haematopoietic stem cells, fetal stem cells, mesenchymal cells, embryonic stem cells, hepatocytes or all of the above, but for different disease indications? This paper discusses why the exploration of stem cells for the treatment of liver disease is of great potential, and delineates some of the hurdles that need to be overcome before patients see benefits from laboratory-based research into stem cell transplantation and function.

Animals↗

Association analysis of monoamine genes with measures of depression and anxiety in a selected community sample of siblings.

Evidence indicates the genetic susceptibility to depression and anxiety is both overlapping and dimensional. In the current study, a quantitative phenotype had been created from several depression and anxiety-related measures in order to index this common genetic susceptibility (G). This has been studied in 119 sibships comprising 312 individuals, selected for extreme scores on G, from a community-based sample of 34,371 individuals. In a pathway based candidate gene study, we examined five microsatellite markers located within or nearby to five serotonin system genes (5HT2C, 5HT1D, 5HT1B, TPH1, and MAOB). Statistical analysis, carried out using QTDT, gave a significant association with a microsatellite downstream of TPH1. Further analysis included a life-events composite as a co-variable, this lead to a stronger association of TPH1. To our knowledge, this is the first study to report an association of the 3' end of TPH1 with continuous measures of depression and anxiety.

Alleles↗

Association between 5-HTTLPR genotypes and persisting patterns of anxiety and alcohol use: results from a 10-year longitudinal study of adolescent mental health.

The serotonin transporter gene (5-HTT) encodes a transmembrane protein that plays an important role in regulating serotonergic neurotransmission and related aspects of mood and behaviour. The short allele of a 44 bp insertion/deletion polymorphism (S-allele) within the promoter region of the 5-HTT gene (5-HTTLPR) confers lower transcriptional activity relative to the long allele (L-allele) and may act to modify the risk of serotonin-mediated outcomes such as anxiety and substance use behaviours. The purpose of this study was to determine whether (or not) 5-HTTLPR genotypes moderate known associations between attachment style and adolescent anxiety and alcohol use outcomes. Participants were drawn from an eight-wave study of the mental and behavioural health of a cohort of young Australians followed from 14 to 24 years of age (Victorian Adolescent Health Cohort Study, 1992 - present). No association was observed within low-risk attachment settings. However, within risk settings for heightened anxiety (ie, insecurely attached young people), the odds of persisting ruminative anxiety (worry) decreased with each additional copy of the S-allele (approximately 30% per allele: OR 0.77, 95% CI 0.62-0.97, P=0.029). Within risk settings for binge drinking (ie, securely attached young people), the odds of reporting persisting high-dose alcohol consumption (bingeing) decreased with each additional copy of the S-allele (approximately 35% per allele: OR 0.74, 95% CI 0.64-0.86, P<0.001). Our data suggest that the S-allele is likely to be important in psychosocial development, particularly in those settings that increase risk of anxiety and alcohol use problems.

Adolescent↗

A survey of perceptions and attitudes among European surgeons towards the clinical impact and management of postoperative ileus.

OBJECTIVE: Postoperative ileus (POI) can negatively affect patient recovery and morbidity, yet the lack of an internationally accepted definition and clinical management pathway for this condition suggest POI may be under-recognized as a clinical problem. The purpose of this survey was therefore to assess current attitudes of surgeons towards the clinical impact and management of POI. SUBJECTS AND METHODS: Telephone interviews were conducted with 230 surgeons from hospitals in the UK, France, Germany, Italy and Spain. RESULTS: Across Europe, there are differences in the terms surgeons use to refer to delayed recovery of gastrointestinal (GI) function and the symptoms, concerns and risks they associate with this condition. Furthermore, there is marked variation in the attitudes of European surgeons towards minimizing the risk of delayed recovery of GI function and in the strategies to manage POI. Additionally, some of the measures applied most commonly by European surgeons are in contrast to evidence in the literature indicating that they have no benefit for quicker resolution of GI function. CONCLUSION: The results suggest that there is a need for clearer definition of the factors that constitute POI, increased recognition of the impact of this condition and improved understanding of the most effective peri-/postoperative care for surgical patients.

Clinical Competence↗

In the world of Dolly, when does a human embryo acquire respect?

For most of the 20th century, it was possible to regard fertilisation as the identifiable point when life begins, because this moment could be defined unequivocally and was thought to be the single most essential biological step in the establishment of a new human entity. Since the successful reproductive cloning of Dolly and other mammals, it is clear that any human cell has the potential to supply the full genome of an embryo, and hence a person, without going through fertilisation. At what point in time do such embryos acquire the respect accorded to human beings? The authors argue that the time of implantation is the most useful point at which the potential and the intention to create a new person are translated into reality, because from that point a new life develops. Implantation differentiates a somatic cell in culture (which is not due respect) from a human entity that has acquired its own identity and developmental potential. The authors examine the value of quickening or viability as alternative developmental stages in the process of acquiring respect for the Dolly embryo.

Animals↗

The pupillary response of cephalopods.

This paper provides the first detailed description of the time courses of light-evoked pupillary constriction for two species of cephalopods, Sepia officinalis (a cuttlefish) and Eledone cirrhosa (an octopus). The responses are much faster than hitherto reported, full contraction in Sepia taking less than 1 s, indicating it is among the most rapid pupillary responses in the animal kingdom. We also describe the dependence of the degree of pupil constriction on the level of ambient illumination and show considerable variability between animals. Furthermore, both Sepia and Eledone lack a consensual light-evoked pupil response. Pupil dilation following darkness in Sepia is shown to be very variable, often occurring within a second but at other times taking considerably longer. This may be the result of extensive light-independent variations in pupil diameter in low levels of illumination.

Animals↗

Implementation of HaemScreen, a workplace-based genetic screening program for hemochromatosis.

There is debate as to whether community genetic screening for the mutation(s) causing hereditary hemochromatosis (HH) should be implemented, due to issues including disease penetrance, health economic outcomes, and concerns about community acceptance. Hemochromatosis is a common preventable iron overload disease, due in over 90% of cases to C282Y homozygosity in the HFE gene. We are, therefore, piloting C282Y screening to assess understanding of genetic information and screening acceptability in the workplace setting. In this program, HaemScreen, education was by oral or video presentation in a group setting. C282Y status was assessed by polymerase chain reaction (PCR) and melt-curve analysis on DNA obtained by cheek-brush sampling. Of eligible participants, 5.8% (1.5-15.8%) attended information and screening sessions, of whom 97.7% (5571 individuals) chose to be tested. Twenty-two C282Y (1 : 253) homozygotes were identified and offered clinical follow-up. There were 638 heterozygotes (1 : 8.7). The determinants for participation have been analyzed in terms of the principles outlined in the Health Belief Model. Widespread screening for HH is readily accepted in a workplace setting, and a one-to-many education program is effective. The level of participation varies greatly and the advertizing and session logistics should be adapted to the specific features of each workplace.

Adolescent↗

Is there an ethical difference between preimplantation genetic diagnosis and abortion?

When a person at risk of having a child with a genetic illness or disease wishes to have an unaffected child, this can involve difficult choices. If the pregnancy is established by sexual intercourse, the fetus can be tested early in pregnancy, and if affected a decision can be made to abort in the hope that a future pregnancy with an unaffected fetus ensures. Alternatively, preimplantation genetic diagnosis (PGD) can be used after in vitro fertilisation (IVF) to select and implant an unaffected embryo that hopefully will proceed to term and produce a healthy baby. We are aware that many individuals at risk regard the latter as ethically more acceptable than the former, and examine whether there is an ethical difference between these options. We conclude that PGD and implantation of an unaffected embryo is a more acceptable choice ethically than prenatal diagnosis (PND) followed by abortion for the following reasons: Choice after PGD is seen as ethically neutral because a positive result ("a healthy pregnancy") balances a negative result ("the destruction of the affected embryo") simultaneously (assuming the pregnancy proceeds to full term and a healthy baby is born). While there is usually the intention to establish a healthy pregnancy after an abortion, this is not simultaneous; A woman sees abortion as a personal physical violation of her integrity, and as the pregnancy proceeds she increasingly identifies with and gives ethical status to the embryo/fetus as it develops in utero and not in the laboratory; Many people see aborting a fetus as "killing", whereas in the case of PGD the spare embryos are "allowed to die". We argue that this difference of opinion gives further weight to our conclusion, but note that this has been addressed and debated at length by others.

Abortion, Induced↗

Disruption of a novel member of a sodium/hydrogen exchanger family and DOCK3 is associated with an attention deficit hyperactivity disorder-like phenotype.

BACKGROUND: Attention deficit hyperactivity disorder (ADHD) is a complex condition with high heritability. However, both biochemical investigations and association and linkage studies have failed to define fully the underlying genetic factors associated with ADHD. We have identified a family co-segregating an early onset behavioural/developmental condition, with features of ADHD and intellectual disability, with a pericentric inversion of chromosome 3, 46N inv(3)(p14:q21). METHODS: We hypothesised that the inversion breakpoints affect a gene or genes that cause the observed phenotype. Large genomic clones (P1 derived/yeast/bacterial artificial chromosomes) were assembled into contigs across the two inversion breakpoints using molecular and bioinformatic technologies. Restriction fragments crossing the junctions were identified by Southern analysis and these fragments were amplified using inverse PCR. RESULTS: The amplification products were subsequently sequenced to reveal that the breakpoints lay within an intron of the dedicator of cytokinesis 3 (DOCK3) gene at the p arm breakpoint, and an intron of a novel member of the solute carrier family 9 (sodium/hydrogen exchanger) isoform 9 (SLC9A9) at the q arm. Both genes are expressed in the brain, but neither of the genes has previously been implicated in developmental or behavioural disorders. CONCLUSION: These two disrupted genes are candidates for involvement in the pathway leading to the neuropsychological condition in this family.

Adult↗

A multicentre phase II study of cisplatin and gemcitabine for malignant mesothelioma.

Our previous phase II study of cisplatin and gemcitabine in malignant mesothelioma showed a 47.6% (95% CI 26.2-69.0%) response rate with symptom improvement in responding patients. Here we confirm these findings in a multicentre setting, and assess the effect of this treatment on quality of life and pulmonary function. Fifty-three patients with pleural malignant mesothelioma received cisplatin 100 mg m(-2) i.v. day 1 and gemcitabine 1000 mg m(-2) i.v. days 1, 8, and 15 of a 28 day cycle for a maximum of six cycles. Quality of life and pulmonary function were assessed at each cycle. The best response achieved in 52 assessable patients was: partial response, 17 (33%, 95% CI 20-46%); stable disease, 31 (60%); and progressive disease, four (8%). The median time to disease progression was 6.4 months, median survival from start of treatment 11.2 months, and median survival from diagnosis 17.3 months. Vital capacity and global quality of life remained stable in all patients and improved significantly in responding patients. Major toxicities were haematological, limiting the mean relative dose intensity of gemcitabine to 75%. This schedule of cisplatin and gemcitabine is active in malignant mesothelioma in a multicentre setting. Investigation of alternative scheduling is needed to decrease haematological toxicity and increase the relative dose intensity of gemcitabine whilst maintaining response rate and quality of life.

Aged↗

Gene therapy for inherited lung disorders: an insight into pulmonary defence.

This review summarizes the latest developments in viral and nonviral gene delivery systems to the lung, and the problems that have to be overcome. Gene delivery has the potential to offer effective treatment to patients with life-threatening lung diseases such as cystic fibrosis and alpha(1)-antitrypsin deficiency, and could modify gene-environment relationships in asthma and other respiratory diseases. Phase I clinical trials conducted in the early 1990s showed that in principle gene transfer to the lung was safe. Although the preliminary results gave encouraging laboratory data, gene expression from viral or nonviral gene delivery systems was too inefficient or transient to offer clinical benefit. Initial optimism gave way to the realization that gene therapy to the lung was unlikely to be straightforward. The host innate and acquired immune system, which protects against infection from inhaled bacteria and viruses, represents a major barrier to successful gene transfer to the lung. A better understanding of the immunological barriers which exist in the lung may allow the development of pharmacological and/or immunological agents that modulate the host immune system to allow for a more continuous and regulated level of gene expression following gene transfer.

Drug Delivery Systems↗

Chromosome abnormalities identified by comparative genomic hybridization in embryos from women with repeated implantation failure.

Using comparative genomic hybridization, we have detected chromosome abnormality in 76/126 (60%) single blastomeres biopsied prior to implantation from embryos from 20 women with repeated implantation failure following IVF. The abnormalities detected included aneuploidy for one or two chromosomes [32/126 (25%)] and complex chromosomal abnormality [37/126 (29%)]. Most of the chromosomes involved in single aneuploidy were those commonly found in live births or spontaneously aborted fetuses, whereas a greater range of chromosomes were involved in double aneuploidy. In blastomeres with complex abnormality, random and extensive loss and gain of all the chromosomes was observed. Further blastomeres from 25 embryos with single or double aneuploidy and 11 embryos with complex abnormality were analysed following embryo disaggregation. The specific abnormality was confirmed in the majority of cases and in some cases could be assigned as errors in meiotic or mitotic segregation. Complex abnormalities, suggestive of errors in cell cycle regulation, were present in a slightly higher proportion of these embryos than were seen in our previously studied cohort of surplus embryos. The disruption of the normal sequence of chromosome replication and segregation in early human embryos, caused either by maternal cytoplasmic factors or mutations in cell cycle control genes, may be a common cause of repeated implantation failure.

Adult↗

Detection of the CD56+/CD45- immunophenotype by flow cytometry in neuroendocrine malignancies.

AIMS: Antibodies against CD56 are primarily used in flow cytometric studies to detect natural killer cells. However, they may be useful in the identification of neuroendocrine malignancies, especially if the cells do not express CD45, indicating a non-leucocyte origin. METHODS: A retrospective review was conducted on all solid tissue flow cytometric studies performed between January 1997 and September 2001, to identify all cases with a CD56+/CD45- immunophenotype. RESULTS: Twelve neuroendocrine malignancies (five metastatic small cell carcinomas, three Merkel cell carcinomas, two metastatic undifferentiated neuroendocrine carcinomas, one metastatic pancreatic neuroendocrine carcinoma, and one neuroblastoma) were identified. CONCLUSIONS: CD56+/CD45- neuroendocrine malignancies are only rarely detected in the flow cytometric analysis of solid tissue samples. However, the recognition of this immunophenotype is important to avoid their misclassification as natural killer cell malignancies. Furthermore, flow cytometry assists in the rapid identification of such cases, so that appropriate immunohistochemical studies can be performed to facilitate their correct diagnosis.

Antigens, Neoplasm↗