PubMed Health⌕ Search

Biomedical subjects

J Powell

Publications and source records attributed to J Powell.

At least 37 records · Page 2Linked to original sources
PubMed2004

Chlamydia trachomatis prevalence in men in the mid-west of Ireland.

OBJECTIVES: To estimate the prevalence of chlamydia infection in young men in the Mid-Western Health Board Region of Ireland, and to determine risk factors for its acquisition. METHODS: Consecutive men attending orthopaedic clinics (OPD), and a university sports arena (UL) were recruited to a chlamydia prevalence study. All men aged 17-35 who had been sexually active and had not passed urine in the last hour were eligible. Information about chlamydia was given, informed consent obtained, and a self administered questionnaire was completed. A first void urine (FVU) was collected and tested by ligase chain reaction (LCR). RESULTS: 82% (207/252) of men from OPD, and 60% (186/310) from UL participated. 6.3% (13/207) from the OPD and 5.4% (10/186) from UL tested LCR positive, giving an overall prevalence of 5.9% (23/393). Proved risk factors for chlamydial positivity were: (1) more than one sexual partner in previous 6 months, (2) more than eight lifetime sexual partners, (3) current symptoms (dysuria or discharge). No statistical significance was found for age, condom use, smoking, days since last sexual intercourse and previous GUM clinic attendance. No statistically significant difference to cost effective prevalence of 6% was shown. CONCLUSIONS: A 5.9% prevalence of Chlamydia trachomatis was found which is cost effective to screen and treat. Non-invasive screening of men in the community was possible. Numbers of sexual partners and current symptoms were significant risk factors. Since only 25% of men in this laboratory were diagnosed with chlamydia outside the GUM clinic, compared with 59% of women, it is important that community screening of men is promoted.

Adolescent↗
PubMed2003

Acute administration of nutritionally sourced tryptophan increases fear recognition.

RATIONALE: The serotonin precursor tryptophan (TRP) has been widely used as a nutritional supplement and antidepressant. Recently, however, the use of TRP has been severely restricted due to its association with the eosinophilic myalgic syndrome, an autoimmune disorder probably caused by ingestion of a contaminant produced in certain TRP manufacturing processes. OBJECTIVES: To determine the bioavailability of a nutritional source of TRP obtained from milk protein and to assess whether administration of this material produced neuroendocrine and neuropsychological effects consistent with increased brain serotonin activity. METHODS: We studied 24 healthy subjects who ingested approximately 1.8 g of nutritionally-sourced TRP or placebo in a double-blind, parallel group, design. We carried out venous sampling for amino acid and hormone estimation and performed a test of emotional processing using a facial expression recognition task. RESULTS: The nutritionally-sourced TRP caused a substantial increase in the availability of TRP in plasma. Relative to placebo the TRP material produced some evidence of an increase in plasma cortisol, and enhanced the perception of fearful and happy facial expressions. CONCLUSIONS: A nutritional source of TRP increased the availability of TRP for brain serotonin synthesis and produced endocrine and neuropsychological changes consistent with increased brain serotonin function. The effect of TRP on emotional processing may be relevant to its reported activity in primate studies of social behaviour.

Adult↗
PubMed2003

The effect of a nutritional source of tryptophan on dieting-induced changes in brain 5-HT function.

BACKGROUND: Dieting in healthy women results in a decrease in the availability of tryptophan (TRP), the amino-acid precursor of serotonin (5-HT), for brain 5-HT synthesis. This is associated with increases in the prolactin response to 5-HT drug challenge suggesting a 'supersensitivity' of 5-HT neuroendocrine responses. The aim of the study was to assess whether increased TRP intake during dieting would prevent the changes in TRP availability and 5-HT neuroendocrine function. METHOD: Fifty female subjects underwent a 1000 kcal daily diet for 3 weeks. In the final week of the diet subjects were randomly allocated to receive either nutritionally-sourced TRP (1.8 g daily) or placebo in a double-blind, parallel group, design. RESULTS: TRP supplementation failed to modify the dieting-induced reduction in fasting TRP availability to the brain. However, in contrast to placebo-treated subjects, subjects receiving additional TRP did not show enhanced prolactin responses to intravenous TRP challenge. CONCLUSIONS: The decrease in TRP availability produced by dieting may be due to increased TRP metabolism rather than decreased TRP intake. While TRP treatment did not increase fasting TRP availability it may have modified the effect of dieting on brain 5-HT function. Further studies will be needed to see if this effect of TRP has consequences for the effectiveness of dieting as means of weight control.

Administration, Oral↗
PubMed2003

Treatment of oro-facial hypersensitivity following brain injury.

A 56 year old man who was 10 months post-severe traumatic brain injury was unable to tolerate oral hygiene. He had oro-facial hypersensitivity, oral dyspraxia and limited oral function. Poor oral hygiene with coating of oral structures and infection was present. An intensive systematic desensitization programme over 2 weeks, even at this late stage post-injury, increased oral tolerance and allowed full oral hygiene. Participation in oral hygiene and functional patterns of movement also improved, enabling some oral nutritional intake. This case study provides controlled evidence, very little of which exists in the literature, to demonstrate the effectiveness of these treatment techniques

Accidents↗
PubMed2003

Contractures in the post-stroke wrist: a pilot study of its time course of development and its association with upper limb recovery.

BACKGROUND: Contractures are common in a stroke population, yet there is little information on the time course of development. OBJECTIVES: Investigate quantitatively changes associated with contracture formation in an acute stroke population. STUDY DESIGN: Longitudinal study on 22 subjects who were 2-4 weeks post stroke. OUTCOME MEASURES: Contractures were assessed by quantifying the resting posture, resistance to passive movement and passive range of movement. Upper limb function was measured using the Action Research Arm Test and the Nine-Hole Peg Test. Active range of extension, wrist extension strength (isometric), grip strength and neglect were also measured. REPEATED MEASURES: Following an initial assessment, repeated measurements were taken at 4, 8, 20 and 32 weeks after recruitment. RESULTS: Two distinct subgroups, one capable of some functional movement (F group; 8 subjects) and another which was not (NF group; 14 subjects), were identified at the start of the study. The NF group showed changes associated with contracture formation at the wrist, i.e., reduction in the passive range of movement, an increase in resistance to passive movement and a worsening of the flexion posture. Changes were observed from the time of recruitment even though neglect improved. The F group showed improvements in upper limb function and there was no evidence to support contracture formation. CONCLUSIONS: Subjects most prone to contracture formation were those who showed no signs of early functional recovery (2-4 weeks after the stroke). Changes consistent with adaptive shortening were seen from week 4 of the study period.

Adult↗
PubMed2003

The NCI/CIT microArray database (mAdb) system - bioinformatics for the management and analysis of Affymetrix and spotted gene expression microarrays.

A scalable, modular, enterprise-level system for both microarray databasing and analysis over the Internet has been developed over the past four years by the National Cancer Institute's Center for Cancer Research in collaboration with NIH's Center for Information Technology. This completely Web-based system, called mAdb (for microArray database), is currently supporting over 810 registered users and collaborators at NIH and contains over 22,000 microarray experiments, making it one of the largest collections of microarray data in existence. In addition, the mAdb system has been ported for the Netherlands Cancer Institute, the Genome Institute of Singapore, and the CDC. This system has been used for a wide variety of scientific experiments spanning the range from cancer to studies of early development, and for human, mouse, rat, yeast, and numerous microbial organisms.

Animals↗
PubMed2002

Surgical workload and outcome after resection for carcinoma of the oesophagus and cardia.

BACKGROUND: Performing cancer surgery in high-volume centres may lead to improved outcomes. This study explored the relationship between annual workload and outcome following resection for carcinoma of the oesophagus and cardia. METHODS: The study was a retrospective case-note review of 1125 patients who had surgery for cardio-oesophageal cancer in the West Midlands region of England. Outcome measures were 30-day mortality and long-term survival. RESULTS: The overall 30-day mortality rate was 10.0 per cent with a median survival of 14 months and a 5-year survival rate of 17.2 per cent. Increasing age, advanced stage of disease and emergency resection independently affected outcome adversely. Forty-one infrequent operators (fewer than four resections per year) performed 146 resections (13.0 per cent), 18 intermediate operators (between four and 11 resections per year) performed 488 resections (43.4 per cent) and five frequent operators (12 or more resections per year) performed 491 resections (43.6 per cent). The 30-day mortality rate was greatest in the infrequent group (15.1 per cent) compared with both the intermediate group (6.6 per cent; adjusted odds 0.40, P = 0.004) and the frequent group (11.8 per cent; odds 0.73, P = 0.28). There were no differences in survival rates between the groups, and no difference in outcome between high- and low-volume hospitals. CONCLUSION: In this unselected population-based series there was little evidence of a trend of improving 30-day mortality rate with increasing workload, or between workload and long-term survival.

Adenocarcinoma↗
PubMed2002

Linear IgA disease: successful treatment with erythromycin.

Conventional first-line treatments for linear IgA disease (and the related chronic immunobullous disease of childhood) include topical steroids and dapsone, both of which may be associated with potentially serious side-effects. Alternative anti-inflammatory therapies such as tetracycline and macrolide antibiotics, have been used to treat other immunobullous disorders and we now report an adult case of linear IgA disease and a paediatric case of mixed immunobullous disease of childhood that both responded to the macrolide antibiotic erythromycin. The mode of action is speculative and anti-inflammatory mechanisms are unclear. Nevertheless, from a clinical perspective, erythromycin may have a role in the treatment of linear IgA disease and could be considered ahead of many other, perhaps potentially more toxic, therapies.

Anti-Bacterial Agents↗
PubMed2002

The influence of 4G/5G polymorphism in the plasminogen activator inhibitor-1 gene promoter on the incidence, growth and operative risk of abdominal aortic aneurysm.

BACKGROUND: a single base pair deletion/insertion (4G/5G) polymorphism in the plasminogen activator inhibitor (PAI-1) promoter appears to influence PAI-1 synthesis (increased PAI-1 and inhibition of fibrinolysis with the 4G allele) and survival after severe trauma. OBJECTIVE: to identify whether the 4G/5G polymorphism influences the natural history of abdominal aortic aneurysm (AAA). METHODS: Four hundred and sixty patients with small AAA were genotyped for the 4G/5G polymorphism. AAA growth was assessed from serial ultrasonographic measurements, subject to linear regression analysis. Mortality following eventual elective surgery was recorded. RESULTS: the frequency of the 3 genotypes (4G4G, 4G5G and 5G5G) was in Hardy-Weinberg equilibrium and similar to that in a healthy population. The mean aneurysm growth rate was 0.37, 0.35 and 0.44 cm/year respectively for patients of 4G4G, 4G5G and 5G5G genotype respectively, p = 0.07. The 30d mortality following open elective aneurysm repair was 8% (7/87), 8% (11/145) and 0% (0/56) for patients of 4G4G, 4G5G and 5G5G genotype respectively, giving a higher mortality for those carrying a 4G allele p = 0.03. CONCLUSIONS: polymorphism of the PAI-1 gene promoter does not influence the development of AAA, although AAA growth is faster for patients of 5G5G genotype. However, this genotype (5G5G), which is associated with enhanced fibrinolysis, appears protective following open aneurysm repair. This effect of PAI-1 genotype on survival following surgery is likely to have widespread significance in vascular and general surgery.

Aged↗
PubMed2002

Community based rehabilitation after severe traumatic brain injury: a randomised controlled trial.

OBJECTIVE: Evaluation of multidisciplinary community based outreach rehabilitation after severe traumatic brain injury (TBI). METHODS: A randomised controlled trial compared outreach treatment (mean of two sessions a week for 27.3 (SD 19.1) weeks) in community settings such as participants' homes, day centres, or workplaces, with provision of written information detailing alternative resources. Follow up for an average of 24.8 months after initial allocation was by a blinded independent assessor. Participants were aged 16-65, had sustained severe TBI between 3 months and 20 years previously, and had no other neurological conditions. Of 110 initially allocated, 48 outreach and 46 information participants were successfully followed up. Primary outcome measures (Barthel index (BI) and the brain injury community rehabilitation outcome-39 (BICRO-39)) focused on levels of activity and participation. Secondary measures were the functional independence measure and the functional assessment measure (FIM+FAM) and, in a subgroup of 46 participants, the hospital anxiety and depression scale. Analyses were non-parametric. RESULTS: outreach participants were significantly more likely to show gains on the BI and the BICRO-39 total score and self organisation and psychological wellbeing subscales. There were likewise strong trends (p<0.10) for BICRO personal care and mobility, and on the FIM+FAM for personal care and cognitive functions. Differential improvements were not seen for indices of socializing, productive employment, anxiety, or depression. Median changes on individual subscales were small, reflecting the diversity of the clinical population; however, 40% of outreach but only 20% of information participants made a clinically significant improvement of 2+ points on at least one BICRO-39 scale. Time since injury was unrelated to the magnitude of gains. CONCLUSIONS: This is the first RCT of multidisciplinary community rehabilitation after severe TBI, and suggests that even years after injury it can yield benefits which outlive the active treatment period.

Activities of Daily Living↗
PubMed2002

Psychosocial outcomes at three and nine months after good neurological recovery from aneurysmal subarachnoid haemorrhage: predictors and prognosis.

OBJECTIVES: To investigate (1) the prevalence of various aspects of cognitive and psychosocial dysfunction, including post-traumatic stress symptoms, over nine months after subarachnoid haemorrhage (SAH); (2) whether SAH is preceded by increased life stress; (3) to what extent adverse outcomes may be predicted from preillness life stress, early neurological impairment, age, and sex; and (4) relations between emotional and functional outcomes. METHODS: 52 patients with good neurological recovery after surgery for SAH were each matched for age, sex, and occupation with a healthy control participant. SAH patients were assessed three and nine months postdischarge on measures of cognitive functioning, mood, and social functioning. Objective stressors and subjective life change during the preceding year were rated retrospectively. Controls completed measures of mood and social functioning once only. RESULTS: Compared with controls, SAH patients showed increased mood disturbance, subtle cognitive impairment, and abnormally low independence and participation on measures of social functioning. 60% showed clinically significant post-traumatic stress symptomatology (intrusive thoughts or avoidance of reminders) at three months and 30% at nine months. Independence in activities of daily living was greatly reduced in half to a third of the sample at both three and nine months. Productive employment was below the 10th percentile of the control group for 75% of patients at three months and for 56% at nine months; this outcome could not be predicted from selected demographic, premorbid, or clinical variables but dependence on others for organisational activities was predicted by impaired prose recall. Mood at nine months was strongly predicted by prior mental health problems, poor physical health, dysphasia, and impaired prose recall at three months. There was no evidence of an abnormally high level of stressful life events in the year before SAH, although patients rated their subjective level of stress in this period slightly more highly than did the control participants. CONCLUSIONS: These findings highlight the need for structured support and treatment after surgery for SAH to reduce persisting mood disturbance and increase independence and participation.

Adult↗
PubMed2002

Genetic variability in the insulin signalling pathway may contribute to the risk of late onset Alzheimer's disease.

OBJECTIVE: To test the hypothesis that polymorphic variation in insulin signalling genes may underlie the shared risk of dysfunctional insulin signalling and late onset Alzheimer's disease (AD). The p85alpha subunit of phosphatidyl inositol 3 kinase (PIK3R1) and the regulatory subunit 3 of protein phosphatase 1 (PPP1R3) were selected as candidate genes because both encode key proteins involved in insulin signalling and because polymorphisms in these genes have been previously implicated in insulin resistance or type II diabetes. METHODS: Analysis of the Met326Ile PIK3R1 and the Asp905Tyr PPP1R3 polymorphisms in 202 patients with late onset AD and 160 or 170 age matched normal subjects. RESULTS: Logistic regression analysis using the recessive genetic model showed significant differences in genotype and allelic frequencies between the AD group and normal controls (genotypes: odds ratio (OR) 2.09, 95% confidence interval (CI) 1.17 to 3.74, p = 0.01; alleles: OR 1.99, 95% CI 1.17 to 3.40, p = 0.01) for the Met326Ile PIK3R1 polymorphism that were female specific. Additionally, in the dominant genetic model a marginally significant association in genotype frequencies between the Asp905Tyr PPP1R3 polymorphism and AD was observed (genotypes: OR 1.85, 95% CI 1.03 to 3.30, p = 0.04; alleles: OR 1.68, 95% CI 0.98 to 2.88, p = 0.06). Both polymorphisms were tested for their interactions with sex and the presence of the apolipoprotein E epsilon 4 allele. CONCLUSIONS: The results support the hypothesis for a common genetic aetiology predisposing to insulin resistance and AD.

Age Factors↗
PubMed2002

Effect of sub-lethal concentrations of aluminium on the filtration activity of the freshwater mussel Anodonta cygnea L. at neutral pH.

Significant amounts of aluminium (Al) are commonly present in rivers and lakes, largely in particulate form in neutral waters. Freshwater bivalves, as filter feeders are therefore exposed to both particulate and dissolved metal and are potentially vulnerable to Al. The effect of Al on filtering behaviour of the freshwater mussel Anodonta cygnea L. was investigated during short (1 hour) and long-term (15 days) exposure to environmentally relevant concentrations (250 and 500 microg l(-1)) at neutral pH. Water flow through the outflow siphon was monitored as an indicator of pumping capacity. Short-term (1 hour) exposure to 500 microg l(-1) added Al produced an irreversible decrease in the duration of filtering periods, presumably as an avoidance response to the toxicant. One-hour exposure 250 microg l(-1) Al had no detectable effect. When mussels were exposed to 250 or 500 microg l(-1) added Al for 15 days, siphon activity measured in days 11-15 of exposure was inhibited by 50% and 65%, respectively, compared to pre-exposure levels. Recovery occurred following transfer of mussels to uncontaminated water. Interaction between Al and freshwater bivalves at neutral pH may affect both the performance of the mussels and the chemical speciation of the metal in the natural environment.

Aluminum↗
PubMed2002

Lichen sclerosus. A review.

Lichen sclerosus is a chronic inflammatory skin condition that can cause substantial physical and psychological morbidity. It most commonly affects women in the anogenital region, but may affect any area of skin in either sex at any age. Not only does it cause itching and soreness, but also urinary and sexual problems. There is an increased risk of developing squamous cell carcinoma in the genital area in both female and male sufferers, thus long term follow-up may be justified. The aetiology of Lichen sclerosus is unknown but genetic factors play a role, and chronic infection had been postulated but not proven. The association with autoimmune disease is also well recognized. The mainstay of treatment for genital lichen sclerosus is potent topical steroid. Surgery may be required only to relieve the effect of scarring. Current research to understand the pathogenesis of disease may allow us to target specific intervention in the future.

Female↗
PubMed2001

Relation of gene expression phenotype to immunoglobulin mutation genotype in B cell chronic lymphocytic leukemia.

The most common human leukemia is B cell chronic lymphocytic leukemia (CLL), a malignancy of mature B cells with a characteristic clinical presentation but a variable clinical course. The rearranged immunoglobulin (Ig) genes of CLL cells may be either germ-line in sequence or somatically mutated. Lack of Ig mutations defined a distinctly worse prognostic group of CLL patients raising the possibility that CLL comprises two distinct diseases. Using genomic-scale gene expression profiling, we show that CLL is characterized by a common gene expression "signature," irrespective of Ig mutational status, suggesting that CLL cases share a common mechanism of transformation and/or cell of origin. Nonetheless, the expression of hundreds of other genes correlated with the Ig mutational status, including many genes that are modulated in expression during mitogenic B cell receptor signaling. These genes were used to build a CLL subtype predictor that may help in the clinical classification of patients with this disease.

Gene Expression↗