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Biomedical subjects

S Knight

Publications and source records attributed to S Knight.

At least 19 recordsLinked to original sources

The natural history of Niemann-Pick disease type C in the UK.

Niemann-Pick disease type C (NPC) is an autosomal recessive, neurovisceral lipid storage disorder. Mutations in two genes (NPC1 and NPC2) produce indistinguishable clinical phenotypes by biochemical mechanisms that have not yet been entirely clarified. The wide spectrum of clinical presentations of NPC includes hepatic and pulmonary disease as well as a range of neuropsychiatric disorders. Late-onset disease has been increasingly recognized as the biochemical diagnosis of NPC has been more widely applied in adult neurology clinics. The clinical presentation and follow-up of 94 patients with NPC is described, 58 of whom were still alive at the time this report was prepared. The age at diagnosis ranged from the prenatal period (with hydrops fetalis) up to 51 years. This review of NPC patients in the UK confirms the phenotypic variability of this inherited lipid storage disorder reported elsewhere. Although a non-neuronopathic variant has been described, most patients in this series who survived childhood inevitably suffered neurological and in some cases neuropsychiatric deterioration. While symptomatic treatment, such as anticholinergic and antiepileptic drugs, can alleviate some aspects of the disease, there is a clear need to develop a specific treatment for this progressively debilitating neurodegenerative disorder.

Adolescent↗

Patients with stable long-standing rheumatoid arthritis continue to deteriorate despite intensified treatment with traditional disease modifying anti-rheumatic drugs--results of the British Rheumatoid Outcome Study Group randomized controlled clinical trial.

OBJECTIVE: Patients with rheumatoid arthritis (RA) should start treatment early with the aim of suppressing the inflammatory process completely. It is not known if this strategy should, or can, be continued in later disease. METHODS: In a multicentre, randomized, observer-blinded, controlled trial, 466 patients with established RA (>5 yr), on stable therapy for at least 6 months, were randomized to adequate symptom control/shared care setting (SCSC) or aggressive treatment/hospital setting (ATH). All were reviewed annually by a rheumatologist. The primary outcome after 3 yr was the Health Assessment Questionnaire (HAQ). Others included the OMERACT core set and the Disease Activity Score (DAS) 28. RESULTS: Three hundred and ninety-nine patients completed the trial. There was a significant deterioration in HAQ in both arms. Only the physician global score differed between the arms. CONCLUSIONS: The trial showed no additional benefit of intensified treatment with traditional disease modifying anti-rheumatic drugs (DMARDs) in patients with stable, established RA. It proved hard to suppress C-reactive protein levels. Patients in the SCSC arm were able to initiate treatment changes when their symptoms deteriorated without frequent hospital assessment. Pending further evidence, the model of shared care with annual hospital review is as good as 4-monthly hospital review for these patients.

Aged↗

Uncertainty in predictions of the climate response to rising levels of greenhouse gases.

The range of possibilities for future climate evolution needs to be taken into account when planning climate change mitigation and adaptation strategies. This requires ensembles of multi-decadal simulations to assess both chaotic climate variability and model response uncertainty. Statistical estimates of model response uncertainty, based on observations of recent climate change, admit climate sensitivities--defined as the equilibrium response of global mean temperature to doubling levels of atmospheric carbon dioxide--substantially greater than 5 K. But such strong responses are not used in ranges for future climate change because they have not been seen in general circulation models. Here we present results from the 'climateprediction.net' experiment, the first multi-thousand-member grand ensemble of simulations using a general circulation model and thereby explicitly resolving regional details. We find model versions as realistic as other state-of-the-art climate models but with climate sensitivities ranging from less than 2 K to more than 11 K. Models with such extreme sensitivities are critical for the study of the full range of possible responses of the climate system to rising greenhouse gas levels, and for assessing the risks associated with specific targets for stabilizing these levels.

Journal Article↗

Does magnetic stimulation of sacral nerve roots cause contraction or suppression of the bladder?

AIMS: The aim of this study was to resolve the paradox as to whether magnetic stimulation of sacral nerve roots results in contraction or suppression of the bladder, in both normal individuals and patients with spinal cord injury (SCI). MATERIALS AND METHODS: Seven males with complete SCI and neurogenic detrusor overactivity (NDO) and five normal males were investigated. Bladder capacity and maximum cystometric capacity were determined, respectively, in these groups. Magnetic stimulation was applied to sacral nerve roots using a multi-pulse magnetic stimulator and coil. Stimulation was applied at half capacity, near-full capacity, and during NDO or voiding (in normal individuals). Single and intermittent bursts of stimulation were applied. RESULTS: Neither single nor intermittent bursts of magnetic stimulation of the sacral nerve roots resulted in significant bladder pressure rises. Occasionally, following cessation of the magnetic stimulation bladder contractions were seen in patients with NDO. These contractions had an unpredictable and variable latency. As previously reported, magnetic stimulation suppressed NDO in patients with SCI, and suppressed voiding in normal individuals. CONCLUSIONS: Bladder contractions are occasionally observed in patients with NDO following withdrawal of stimulation. This phenomenon hypothetically arises as a result of removal of the bladder suppression provided by magnetic stimulation, rather than direct motor pathway stimulation (as has been reported by others). The ability of sacral magnetic stimulation to suppress detrusor contractions is reaffirmed.

Adult↗

The fast and the fatal: street racing fatal crashes in the United States.

The objective of this study was to determine the annual incidence of fatal motor vehicle crashes involving street racing and to describe the characteristics of these crashes compared to other fatal crashes in the United States. The National Highway Traffic Safety Administration Fatality Analysis Reporting System data for 1998-2001 were used for the analyses. There were 149 568 fatal crashes and 315 (0.21%) involved street racing and 399 fatalities occurred in these crashes. In contrast to other fatal crashes, street racing fatal crashes were more likely to occur on urban roadways and were nearly six times more likely to occur at travel speeds> or = 65 mph. Compared with other drivers involved in fatal crashes, street racers were more likely to be teenagers, male, and have previous crashes and driving violations. Street racing involves risky driving behaviors and warrants further attention.

Accident Proneness↗

A dose-escalating study of oral eniluracil/5-fluorouracil plus oxaliplatin in patients with advanced gastrointestinal malignancies.

BACKGROUND: Oral eniluracil/5-fluorouracil (5-FU) was shown in early clinical studies to have promising activity against gastrointestinal malignancies. Oxaliplatin in combination with 5-FU also has activity against these tumour types. The primary objective of this study was to determine a tolerable dose for oral eniluracil/5-FU in combination with oxaliplatin. PATIENTS AND METHODS: Twenty-three patients with advanced gastrointestinal malignancies were recruited into this open-label study. Patients received a fixed dose of oxaliplatin (130 mg/m(2) on the first day of a 21-day cycle), and the dose intensity of oral eniluracil/5-FU was gradually increased by escalating the number of days of treatment per course. RESULTS: The maximum tolerated dose intensity was eniluracil/5-FU 10.0/1.0 mg/m(2) twice daily for 16 days in combination with oxaliplatin 130 mg/m(2) on the first day of a 21-day cycle. Dose-limiting toxicities included vomiting and diarrhoea. The objective tumour response rate was 26% with a median duration of response of 15.3 weeks (95% confidence interval 8.5-22.1). Twenty-two patients (96%) experienced neurotoxicity (sensory neuropathy or cold-related dysaesthesia), although only two events were severe (grade 3). CONCLUSIONS: The recommended dose for future study in patients with advanced gastrointestinal cancer is 10.0/1.0 mg/m(2) oral eniluracil/5-FU twice daily for 14 days in combination with oxaliplatin 130 mg/m(2) on the first day of each treatment cycle.

Administration, Oral↗

[Effects of peripheral functional electrostimulation in obstructive bladder instability].

INTRODUCTION: The aim of this study was to assess the effects of peripheral functional electrical stimulation (FES) in patients with detrusor instability (DI) secondary to obstructive Benign Prostatic Hyperplasia (BPH). SUBJECTS, MATERIAL & METHODS: Nine patients with urodynamically proven DI secondary to BPH were investigated. Sensory and pudendo-anal reflex thresholds were determined in each patient to individually optimise FES. A standard fill cystometry was then performed and individually optimised FES was given when an unstable detrusor contraction occurred. Non stimulated contractions were used as controls. The effects of FES were analysed by measuring the mean area under the unstable pressure curves with and without FES and were expressed as percentage suppression. RESULTS: The percentage suppression in the mean area under the curves after stimulation was < 10%. There was no statistically significant difference between controls and FES using a two tailed, paired students t-Test (p > 0.1) at 95% confidence level (p > or = 0.05). CONCLUSION: FES did not significantly suppress unstable bladder contractions in patients with DI secondary to BPH. This finding suggests that obstructive DI does not depend on sacral reflex mechanisms and supports the view that it has a peripheral pathophysiological origin (myogenic and/or nerve endings).

Electric Stimulation Therapy↗

Preliminary indication of a high prevalence of polycystic ovary syndrome in indigenous Australian women.

We aimed to estimate the likely prevalence of polycystic ovary syndrome (PCOS) in indigenous Australian women in a cross-sectional survey based on structured interviews. In the Kimberley region of Western Australia and south-western Victoria, between February and June 1999, women over the age of 18 available for interview and willing to participate were included. Menstrual status, anthropometric measures, fasting blood biochemistry and hirsutism were assessed. A total of 38 premenopausal women completed the survey. Of these, 50% had regular menstrual cycles of normal duration and no hirsutism; seven had oligomenorrhea and hirsutism/hyperandrogenemia; and of the nine women with hirsutism and regular menses, three had hyperandrogenemia. Thus, possibly ten women fulfilled the criteria of PCOS. This unique data set suggests a high prevalence of PCOS in indigenous Australian women. Further research to document this formally is warranted, in view of the potential adverse effects of PCOS on reproduction and metabolism.

Adult↗

Shoulder belts in motor vehicle crashes: a statewide analysis of restraint efficacy.

The purpose of our study was to evaluate the impact of shoulder belt use on motor vehicle crash ejection, morbidity and mortality. We analyzed motor vehicle crash records linked to hospital inpatient data for front seat occupants of passenger cars in Utah between 1994 and 1996 (n = 103,035). Stochastic simulations were used to adjust for possible seatbelt misclassification. There were 276 (0.3%) occupants coded as using only a shoulder belt. The adjusted odds of ejection for shoulder only belted occupants was higher compared to lap-shoulder belted (odds ratio (OR) = 18.9; 95% confidence interval (CI) = 15.1, 25.1) and lap only belted occupants (OR = 4.3; 95% Cl = 2.9, 7.7). There was no difference in the odds of ejection for an occupant using a shoulder belt only and an occupant using no seatbelt (OR = 1.1; 95% CI = 1.0, 1.3). Occupants using a shoulder belt only were more likely to sustain a fatal or hospitalizing injury than lap-shoulder belted (OR = 2.3; 95% Cl = 1.9, 3.0), and lap only belted occupants (OR = 1.8; 95% CI = 1.3, 2.7), while controlling for other covariates. Occupants using only a shoulder belt had the same odds of a fatal or hospitalizing injury as unbelted occupants (OR = 1.1; 95% Cl = 0.9, 1.4). Average hospital inpatient length of stay, charges and injury severity scores were similar for all restraint types. These results stress the need for the use of a lap belt in conjunction with the shoulder belt.

Accidents, Traffic↗

Fc gamma RIII mediates neutrophil recruitment to immune complexes. a mechanism for neutrophil accumulation in immune-mediated inflammation.

Neutrophil accumulation is a hallmark of immune complex-mediated inflammatory disorders. Current models of neutrophil recruitment envision the capture of circulating neutrophils by activated endothelial cells. We now demonstrate that immobilized immune complexes alone support the rapid attachment of neutrophils, under physiologic flow conditions. Initial cell tethering requires the low-affinity Fc gamma receptor IIIB (Fc gamma RIIIB), and the beta(2) integrins are additionally required for the subsequent shear-resistant adhesion. The attachment function of Fc gamma RIIIB may be facilitated by its observed presentation on neutrophil microvilli. In vivo, in a model of acute antiglomerular basement membrane nephritis in which immune complexes are accessible to circulating neutrophils, Fc gamma RIII-deficient mice had a significant reduction in neutrophil recruitment. Thus, the interaction of immune complexes with Fc gamma RIII may mediate early neutrophil recruitment in immune complex-mediated inflammation.

Animals↗

The synergistic relationship between a level I trauma center and a regional pediatric trauma center.

A regional pediatric trauma center and a level I trauma center with pediatric commitment in the same city developed a synergistic relationship addressing all aspects of care for pediatric trauma patients. Although it is unlikely that this model could be used in its entirety by all similar institutions, the principles may prove helpful in creating guidelines and relationships. Categorization, optimal use of resources, timely transportation of seriously injured children to the appropriate facility, and maintaining urgent care capabilities of each institution to care for seriously injured children are imperative. The combined effort resulted in our level I trauma center being verified by the American College of Surgeons and designated by our state Health Department as meeting all the criteria for pediatric trauma care. This experience should encourage every pediatric trauma center located in a children's hospital to become a regional pediatric trauma center. The real benefit from the relationship is that injured children receive optimal care at both institutions.

Adult↗

Analysis of school injuries resulting in emergency department or hospital admission.

OBJECTIVE: To describe the epidemiology of school injuries resulting in emergency department (ED) visits, hospital admission, or death. METHODS: Utah statewide school injuries from 1992 to 1996 were probabilistically linked to statewide ED records (1996 only), inpatient hospital records (1992-1996), and death certificate records (1992-1996). RESULTS: There were 43,881 school injuries for the years 1992 through 1996. In 1996, 1,534 of 6,354 total school injuries (17.5%) resulted in ED evaluation. Between 1992 and 1996, 354 school injuries (0.8%) necessitated hospital admission. The overall rates of school injuries (per 1,000 students) of primary (kindergarten-grade 6) and secondary (grades 7-12) school students requiring ED evaluation were 3.29 and 3.28, respectively; for hospital admission, 0.165 and 0.139. Abbreviated Injury Scale-1990 (AIS-90) regions identified in ED patients were the upper extremity (39.2%), face (20.8%), and lower extremity (17.1%), while AIS regions among inpatients were lower extremity (29.1%), upper extremity (26.6%), and head (22.6%). There were a total of 1,123 hospital days, and total charges of $2.16 million. The ED charges totaled $545,000. Median length of hospital stay was 1 day, and median hospital charge was $3,080. There were four fatalities. CONCLUSIONS: This study emphasizes the significance of school injuries and the need for interventions to prevent these injuries

Adolescent↗

Towards integrated catchment management, Whaingaroa, New Zealand.

The paper examines progress towards integrated catchment management and sustainable agriculture at Whaingaroa (Raglan), New Zealand. Application of the Canadian "Atlantic Coastal Action Program" model (ACAP) has been only partially successful within New Zealand's bicultural setting. Even before the introduction of the ACAP process there existed strong motivation and leadership by various sectors of the community. A merging of resource management planning and implementation processes of the larger community and that of the Maori community has not occurred. Research carried out by Crown Research Institutes has clearly shown the actions required to make pastoral farming more sustainable. There are difficulties in the transference to, and uptake of, these techniques by farmers. An examination of the socio-economic context is required. There has been a requirement on local government bodies to tighten their focus as part of recent reform. This has occurred concurrently with a widening of vision towards integrated and sustainable forms of management. This (as well as a clear belief in empowerment of local communities) has lead to Council reliance on voluntary labour. There is a need to account for the dynamic interaction between social and political history and the geological and biophysical history of the area. As part of a re-examination of sustainable development, New Zealand needs to reconcile the earning of the bulk of its foreign income from primary production, with the accelerating ecological deficit that it creates. A sustainability strategy is required linking consumer demand, property rights and responsibilities.

Agriculture↗

Convergent evolution with combinatorial peptides.

Once the sequence of a genome is in hand, understanding the function of its encoded proteins becomes a task of paramount importance. Much like the biochemists who first outlined different biochemical pathways, many genomic scientists are engaged in determining which proteins interact with which proteins, thereby establishing a protein interaction network. While these interactions have evolved in regard to their specificity, affinity and cellular function over billions of years, it is possible in the laboratory to isolate peptides from combinatorial libraries that bind to the same proteins with similar specificity, affinity and primary structures, which resemble those of the natural interacting proteins. We have termed this phenomenon 'convergent evolution'. In this review, we highlight various examples of convergent evolution that have been uncovered in experiments dissecting protein-protein interactions with combinatorial peptides. Thus, a fruitful approach for mapping protein-protein interactions is to isolate peptide ligands to a target protein and identify candidate interacting proteins in a sequenced genome by computer analysis.

Amino Acid Sequence↗

Increase in prevalence of obesity and diabetes and decrease in plasma cholesterol in a central Australian aboriginal community.

OBJECTIVE: To document change in prevalence of obesity, diabetes and other cardiovascular disease (CVD) risk factors, and trends in dietary macronutrient intake, over an eight-year period in a rural Aboriginal community in central Australia. DESIGN: Sequential cross-sectional community surveys in 1987, 1991 and 1995. SUBJECTS: All adults (15 years and over) in the community were invited to participate. In 1987, 1991 and 1995, 335 (87% of eligible adults), 331 (76%) and 304 (68%), respectively, were surveyed. MAIN OUTCOME MEASURES: Body mass index and waist: hip ratio; blood glucose level and glucose tolerance; fasting total and high density lipoprotein (HDL) cholesterol and triglyceride levels; and apparent dietary intake (estimated by the store turnover method). INTERVENTION: A community-based nutrition awareness and healthy lifestyle program, 1988-1990. RESULTS: At the eight-year follow-up, the odds ratios (95% CIs) for CVD risk factors relative to baseline were obesity, 1.84 (1.28-2.66); diabetes, 1.83 (1.11-3.03); hypercholesterolaemia, 0.29 (0.20-0.42); and dyslipidemia (high triglyceride plus low HDL cholesterol level), 4.54 (2.84-7.29). In younger women (15-24 years), there was a trembling in obesity prevalence and a four- to fivefold increase in diabetes prevalence. Store turnover data suggested a relative reduction in the consumption of refined carbohydrates and saturated fats. CONCLUSIONS: Interventions targeting nutritional factors alone are unlikely to greatly alter trends towards increasing prevalences of obesity and diabetes. In communities where healthy food choices are limited, the role of regular physical activity in improving metabolic fitness may also need to be emphasised.

Adolescent↗