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Biomedical subjects

K Nicholson

Publications and source records attributed to K Nicholson.

At least 19 recordsLinked to original sources
PubMed2004

Mission creep: an analysis of accident and emergency room activity in a military facility in Bosnia-Herzegovina.

OBJECTIVE: To evaluate accident and emergency (A&E) room activity at a Role 3 Multinational Integrated Medical Unit (R3 MIMU) facility in Bosnia-Herzegovina. METHODS: Retrospective analysis of all patients attending the A&E room from 1st October 1999-30th September 2002. RESULTS: 1864 casualties are included in the analysis. 52.1% of casualties were Bosnian, 43.8% were military. Mean age of casualties was 35.5 years (SD 18.3), range 1-88 years. Traumatic injury was the leading cause of presentation (58.1%). Following treatment 66.7% of all cases were discharged or returned to unit, with 19.8% admitted to a ward area. During the 3 year period there was a 5 fold increase in the number of Bosnian nationals treated, this included 80 children (<13 years). CONCLUSION: There has been a dramatic increase in Methods A&E use during the period evaluated, Setting of study particularly by the local population. The increasing number of locals treated, both adult and child, has the potential to undermine the R3 MIMU mission and increase dependency within the Bosnian population. A balance is needed to ensure the staff and functions of a hospital are maintained whilst preserving the capability to deal with an influx of military casualties.

Accidents↗
PubMed2003

Altered central somatosensory processing in chronic pain patients with "hysterical" anesthesia.

OBJECTIVE: The authors hypothesized that central factors may underlie sensory deficits in patients with nondermatomal somatosensory deficits (NDSD) and that functional brain imaging would reveal altered responses in supraspinal nuclei. BACKGROUND: Patients with chronic pain frequently present with NDSD, ranging from hypoesthesia to complete anesthesia in the absence of substantial pathology and often in association with motor weakness and occasional paralysis. Patients with pain and such pseudoneurologic symptoms can be classified as having both a pain disorder and a conversion disorder (Diagnostic and Statistical Manual of Mental Disorders-IV classification). METHODS: The authors tested their hypothesis with functional MRI (fMRI) of brush and noxious stimulation-evoked brain responses in four patients with chronic pain and NDSD. RESULTS: The fMRI findings revealed altered somatosensory-evoked responses in specific forebrain areas. Unperceived stimuli failed to activate areas that were activated with perceived touch and pain: notably, the thalamus, posterior region of the anterior cingulate cortex (ACC), and Brodmann area 44/45. Furthermore, unperceived stimuli were associated with deactivations in primary and secondary somatosensory cortex (S1, S2), posterior parietal cortex, and prefrontal cortex. Finally, unperceived (but not perceived) stimuli activated the rostral ACC. CONCLUSIONS: Diminished perception of innocuous and noxious stimuli is associated with altered activity in many parts of the somatosensory pathway or other supraspinal areas. The cortical findings indicate a neurobiological component for at least part of the symptoms in patients presenting with nondermatomal somatosensory deficits.

Adult↗
PubMed2003

Systematic review and economic decision modelling for the prevention and treatment of influenza A and B.

OBJECTIVES: To establish the clinical and cost-effectiveness of amantadine, oseltamivir and zanamivir compared to standard care for the treatment and prevention of influenza. DATA SOURCES: Electronic databases. Reference lists of identified articles and key publications. Relevant trials. REVIEW METHODS: A systematic review and meta-analysis of the randomised evidence was undertaken to investigate the effectiveness of oseltamivir and zanamivir compared to standard care for treatment and prophylaxis use for influenza A and B. An additional systematic review of the effectiveness of amantadine for treatment and prophylaxis use for influenza A in children and the elderly was also undertaken. Economic decision models were constructed to examine the cost-effectiveness and cost-utility of the alternative strategies for treating and preventing influenza A and/or B. This was informed by the systematic reviews outlined above and additional sources of information where required. RESULTS: The systematic review of the treatment of influenza found that oseltamivir reduced the median duration of symptoms in the influenza positive group by 1.38 days for the otherwise healthy adult population, 0.5 day for the high-risk population, and 1.5 days for the children population. This compared to 1.26 days, 1.99 days, and 1.3 for the similar groups for inhaled zanamivir. The systematic review of the prevention of influenza found that the relative risk reduction for oseltamivir was between approximately 75 and 90% and approximately 70 and 90% for inhaled zanamivir depending on the strategy adopted and the population under consideration. For the economic model a base case was constructed that focussed primarily on the health benefits generated by shortening the period of influenza illness. This base case found that, compared to standard care, the estimated cost per quality-adjusted life year ranged from pound 6190 to pound 31,529 for healthy adults, from pound 4535 to pound 22,502 for the 'high-risk' group, from pound 6117 to pound 30,825 for children, and from pound 5057 to pound 21,781 for the residential care elderly population. The base case model included valuations of the health effects of pneumonia (and otitis media in the children's model) based on observed rates in the trials. However it does not include the cost of hospitalisations as only very limited data was available for the effects of antivirals on hospitalisation rates. As for mortality rates, deaths from influenza were rare in trials of neuraminidase inhibitors (NIs). Therefore, suitable data on mortality were not available from these sources. As avoided hospitalisation costs and avoided mortality are potentially important we also carried out sensitivity analysis that involved extrapolating the observed reductions in pneumonias in the NI trials to hospitalisations and deaths. In all four models the cost-effectiveness of NIs is substantially improved by this extrapolation. For prophylaxis, antiviral drugs were compared with vaccination as preventative strategies. In all cases the cost-effectiveness ratios for vaccination were either low or cost-saving. In the base case the cost-effectiveness of antivirals was relatively unfavourable, there were scenarios relating to the elderly residential care model where antivirals as an additional strategy could be cost-effective. CONCLUSIONS: The cost-effectiveness varies markedly between the intervention strategies and target populations. The estimate of cost effectiveness is also sensitive to variations in certain key parameters of the model, for example the proportion of all influenza-like illnesses that are influenza. The effectiveness literature that was used to inform the economic decision model spans many decades and hence great caution should be exercised when interpreting the results of indirect intervention comparisons from the model. Further randomised trials making direct comparisons would be valuable to verify the model's findings.

Antiviral Agents↗
PubMed2001

Psychosocial factors, respiratory viruses and exacerbation of asthma.

The aim of this research was study the role of psychosocial factors in exacerbations of asthma in adults induced by upper respiratory tract infections (URTIs). It involved a longitudinal study (one year) of 92 adults with asthma. The volunteers were 27 men and 65 women 19-46 years of age with a mean duration of wheeze of 19 years. The main outcome measure was symptomatic colds producing asthma exacerbations (infections confirmed by laboratory assays and exacerbation of asthma confirmed by objective changes in peak expiratory flow rate). The results showed that about 20% of the sample did not report an episode. This sub-group had a high proportion of males, low negative affectivity scores and consumed more alcohol. When volunteers with at least one episode were considered it was found that those who reported more negative life events and had low levels of social support had more episodes. Smokers were more likely to have to visit their doctor when they developed a cold-induced exacerbation of asthma. Overall, these results show that health-related behaviours, demographic and psychosocial factors influence susceptibility to and severity of exacerbations of asthma by URTIs.

Adult↗
PubMed2001

Unexplainable nondermatomal somatosensory deficits in patients with chronic nonmalignant pain in the context of litigation/compensation: a role for involvement of central factors?

OBJECTIVE: To address the prevalence and characteristics of nondermatomal somatosensory deficits (NDSD) in subjects with chronic pain in the context of compensation/litigation. METHODS: Data were collected via standardized history, examination, and patient- as well as physician-drawn body maps in a consecutive series of 194 subjects seen for the purpose of an independent medical examination. RESULTS: Forty-nine subjects (25.3%) with primarily widespread pain (often diagnosed as fibromyalgia) presented with hemisensory or quadrotomal deficits to pinprick and other cutaneous stimuli on the side of lateralized pain or worse pain. The NDSD limbs often had impairment of vibration sense (not infrequently associated with "forehead vibration split"), reduced strength, dexterity or movement, and extreme sensitivity to superficial skin palpation or profound insensitivity to deep pain. Spatial, temporal, qualitative, and evolutionary patterns of NDSD emerged associated with cognitive/affective symptoms. NDSD subjects were more often born outside Canada, more likely to be injured at work, present with abnormal pain behavior, and have negative investigations. CONCLUSION: NDSD are a prevalent problem associated with chronic pain. Future research should explore the prevalence of NDSD in other pain populations, the role of personality and related factors, and the underlying biological substrate of these deficits.

Adolescent↗
PubMed2001

Does pain confound interpretation of neuropsychological test results?

There is increasing evidence that pain and related problems (e.g., affective distress, sleep disturbance, medication use) can interfere with cognitive performance and confound the interpretation of neuropsychological test results. This may be of particular concern in cases of the persistent post-concussive syndrome where headache is the primary problem. Such effects can be pronounced, obscuring the effects associated with mild or even much more significant brain injury. However, it remains unclear what specific chronic or acute pain experiences, in what individuals, with or without which associated problems, will actually result in particular performance deficits. Whereas pain may disrupt brain function, this is likely to be temporary and not indicative of permanent impairment of neuropsychological function. Further study of this important topic is warranted.

Data Interpretation, Statistical↗
PubMed2001

Weaving a circle: a relaxation program using imagery and music.

This article examines the imagery and music components of the relaxation program at the Vancouver Centre of the British Columbia Cancer Agency. An outline of the objectives and design of the experiential portion of the sessions is accompanied by a detailed description of the musical elements and influences. Some participant evaluation is also included.

Humans↗
PubMed1999

Extrapyramidal side effects during chronic combined dopamine D1 and D2 antagonist treatment in Cebus apella monkeys.

Previous studies in non-human primates have shown that tolerance to dystonia occurs during chronic dopamine D1 (D1) but not D2 antagonism and induction/aggravation of oral dyskinesia (TD) during D2 but not D1 antagonism. We were therefore interested in determining the effects of combined chronic D1 + D2 antagonism on dystonia and dyskinesia. To this intent, 8 male Cebus apella monkeys were treated 10 weeks with gradually increasing doses of D1 antagonist (NNC 112) + a D2 antagonist (raclopride), followed by 2 weeks of treatment with the D2 antagonist alone. Due to previous neuroleptic exposure, 5 monkeys had TD and all were sensitized to dystonia. During the combined antagonist treatment, tolerance to dystonia occurred; the tolerance disappearing upon discontinuation of the D1 antagonist and continuation of the D2 antagonist alone. Parallel to these results, improvement of TD was seen during the combined antagonist treatment with worsening during the D2 antagonist alone. Both the combined antagonists and the D2 antagonist alone resulted in moderate/severe bradykinesia, with no tolerance. These findings indicate that supplementation of traditional D2 antagonism with a D1 antagonist would lessen the risk of dystonia and allow alleviation of preexisting TD, though parkinsonian side effects might still occur. The findings further indicate that separate dopaminergic mechanisms control dystonia/dyskinesia and parkinsonism.

Animals↗
PubMed1998

Effects of the common cold on mood and performance.

Previous research has shown that both experimentally-induced and naturally occurring upper respiratory tract illnesses (URTIs) influence mood and mental functioning. None of the previous studies of naturally occurring colds has conducted appropriate virological assays to determine the nature of the infecting agent. This is an essential methodological step in studies of malaise associated with URTIs. The aim of this research was to investigate the effects of naturally occurring colds on mood and objective measures of performance. This was done by first conducting a cross-sectional comparison of 37 healthy people and 158 volunteers with colds and then a longitudinal study in which 100 volunteers developed colds and 87 remained healthy. Virological techniques were used to identify infecting agents and comparisons made across the different groups. The results showed that having a cold was associated with reduced alertness and slowed reaction times. These effects were observed both for colds where the infecting virus was identified and those where it was not. Similar effects were obtained for both rhinovirus and coronavirus colds. One may conclude that upper respiratory tract illnesses lead to a reduction in subjective alertness and impaired psychomotor functioning. This was true for both illnesses where the infecting agent was identified and for those clinical illnesses where no virus was detected. It is now important to identify the mechanisms linking infection and illness with the behavioural changes. Similarly, the impact of these effects on real-life activities such as driving needs examining. Finally, methods of treatment need to be developed which not only treat the local symptoms of the illnesses but remove the negative mood and the performance impairments.

Adolescent↗
PubMed1995

[Abuse of Ecstasy (3,4-methylenedioxymethamphetamine). Pharmacological, neuropsychiatric and behavioral aspects].

Ecstasy (3,4-methylenedioxymethamphetamine) is a popular recreational drug, a "designer drug", which has been developed from the basic structure in amphetamine. Ecstasy has now reached the illegal drug market in Denmark via the US, Great Britain and Sweden. The drug is related to a certain youth culture from which it is estimated that many drug abusers have been recruited. The desired effects of ecstasy, namely enhanced openness, awareness and empathy, have previously been used in various therapeutic connections. In later years the drug has led to abuse which, in connection with certain cultural behaviour patterns (for example in discotheques), can cause dangerous psychiatric as well as somatic effects. The undesirable psychiatric effects range from fear through depression to actual psychoses, and the somatic effects vary from symptoms of increased sympathetic activity to malignant hyperthermia, disseminated intravascular coagulation, rhabdomyolysis, renal failure, and lethal hepatotoxicity. The last mentioned symptoms occur in connection with prolonged physical activities such as exhausting dancing sessions. The article discusses the available treatments for conditions of abuse and stresses the need for prophylactic efforts in the form of information and awareness of the problem.

Brain Diseases↗
PubMed1995

Behavior and the basal ganglia.

When viewed as a whole, these basal ganglia-thalamo-cortical circuits appear to play a modulating role in a wide range of behaviors. At the cortical level, given convergence upon specified regions within the frontal lobes, the behaviors in question would be those dependent upon SMA, premotor, frontal eye fields, dorsolateral, and orbitofrontal outflow targets. Broadly speaking, processes such as the generation, maintenance, switching, and blending of motor, mental, or emotional sets would be involved. Accordingly, in basal ganglia disease, the planning and the execution of the above behavioral domains can be affected. Given the diversity and complexity of activity within the basal ganglia, the consequences of disruption depend largely upon lesion site and the associated interplay of neurochemical factors. For example, in the motor domain, damage to various striatal circuitry levels can result in either hypo- or hyperkinetic disorders of movement. Following this analogy, it might also be said that diverse lesions, depending on site, can result in problems with the development and maintenance of behavioral sets ("hypophrenic") versus problems in relinquishing preferential sets ("hyperphrenic"). These contrasting patterns are best represented in PD and OCD, respectively. In the latter case, however, the "hyperphrenic" pattern would only apply to those behaviors which are part of the obsessional rituals. This suggests that procedural system "overdrive" remains domain-specific as is the case for most operations within the procedural system. To return to the broad principle of habituation, a process first described in the context of the visual system and its connections with the tail of the caudate nucleus, it would be tempting to view PD and OCD as disorders of "under" and "over" habituation to behavioral routines. Unfortunately, the situation has proven to be more complex in view of recent neuropsychological findings (Nicholson et al., in preparation). Using a variety of problem-solving and other cognitive tasks, both PD and OCD patients were found to require more practice and/or the provision of external guidelines to facilitate habit formation. Thus, in both cases, as in other disorders of the basal ganglia, the establishment of useful heuristics by which to direct adaptive behavior suffers. OCD patients therefore appear to have at least two compartmentalized types of basal ganglia dysfunction: the ritualistic compulsions and obsessions as well as the heuristic inefficiency (i.e., poor procedural mobilization). PD patients would also suffer a similar fate as it is known that the degrees of motor versus nonmotor (i.e., procedural) deficit are poorly correlated (42).(ABSTRACT TRUNCATED AT 400 WORDS)

Affect↗
PubMed1994

Prognosis in cystic fibrosis treated with continuous flucloxacillin from the neonatal period.

All newborn infants in East Anglia are screened for cystic fibrosis by blood immunoreactive trypsin assay at 7 days. Thirty eight infants with cystic fibrosis were randomised to treatment with either continuous oral flucloxacillin 250 mg/day (group P, n = 18) or with episodic antimicrobials as clinically indicated (group E, n = 20). Their progress was monitored from diagnosis to 24 months by a nurse coordinator who visited all infants regularly, at home and in hospital, to collect anthropometric, dietary, clinical, and microbiological data. Mean (range) age of confirmation of diagnosis was 5.7 weeks (1-14 weeks). There was no significant difference in birth weight, genotype, immunoreactive trypsin concentration, neonatal history, symptoms at diagnosis, pancreatic enzyme supplementation, or parental smoking history between the groups. Infants in group E had more frequent cough and a greater number of Staphylococcus aureus isolates than infants in group P. More infants of group E were admitted to hospital, had higher admission rates during the second year (19 v 5), for longer periods (6.4 v 2.2 days), despite receiving more than double the number of courses of antibiotics than group P infants (in addition to flucloxacillin). Continuous prophylactic flucloxacillin from early diagnosis of cystic fibrosis is associated with improved clinical progress during the first two years of life.

Bacterial Infections↗
PubMed1993

Primary diagnosis predicts prognosis of lung transplant candidates.

Optimal timing for consideration of lung transplantation remains unknown. This study examined survival in patients with end-stage lung disease awaiting transplantation. Primary disease group and relevant indicators were evaluated. Ninety-three patients who met selection criteria for lung transplantation were included in this retrospective review. Of this total, 31% underwent transplantation, 38% remain waiting, and 31% died. Results demonstrate that the six-month actuarial survival rate was 89% for Eisenmenger's syndrome, 81% for emphysema, 74% for cystic fibrosis, 60% for primary pulmonary hypertension, and 38% for interstitial lung disease. Parameters found to be significant included a higher mean right atrial pressure in primary pulmonary hypertension patients who died awaiting transplantation, and lower forced expiratory volume in one second and forced vital capacity measurements in cystic fibrosis patients who died awaiting transplantation. We conclude that primary disease significantly affects survival in candidates awaiting transplantation. Reliable indicators predictive of survival are not available. Earlier referral for consideration of lung transplantation is recommended.

Adolescent↗
PubMed1993

Cystic fibrosis identified by neonatal screening: incidence, genotype, and early natural history.

The incidence of cystic fibrosis over the last 10 years in East Anglia (a region of the United Kingdom with a population of 2.1 million) has halved. This has happened during the establishment of a neonatal screening programme, which has enabled early diagnosis, genetic counselling, and lately the option of prenatal diagnosis in subsequent pregnancies. One hundred and seven children were born with cystic fibrosis between 1981 and 1990, eight of whom were siblings. The Guthrie blood spots of 82 infants detected by neonatal immunoreactive trypsin screening between 1981 and 1990 were examined for the presence of the most common cystic fibrosis gene mutation (delta F508). It was present in 135 (82%) of the 164 cystic fibrosis genes analysed with 54 (66%) cases being homozygous and 27 (33%) heterozygous. Sixty nine per cent of infants were symptomatic at the time of diagnosis regardless of genotype. No association was found between the early clinical or biochemical features of the disease and homozygosity or heterozygosity for this mutation. Screening for cystic fibrosis using the blood immunoreactive trypsin assay alone remains an effective method of identifying infants with the disease soon after birth, thereby allowing early therapeutic intervention. Genetic counselling and prenatal diagnosis have contributed to a reduction in the number of children born with cystic fibrosis, but may not entirely explain the decreasing incidence of the disease.

Cystic Fibrosis↗
PubMed1993

Influenza immunisation: policies and practices of general practitioners in England, 1991/92.

A large questionnaire survey of general practices in England to determine the most recent policies, perceptions, and procedures for influenza immunisation, and the extent to which individual practice characteristics were related to levels of vaccine distribution, was conducted during January and February 1992. The results indicate that the proportion of practices with influenza immunisation policies has increased considerably since the mid 1980s. However, some notable shortcomings remain and practice characteristics appear to have little influence on vaccine delivery, suggesting that other factors may also be important.

Aged↗
PubMed1991

High-grade T-cell lymphoma following treatment with cyclosporin A.

A 47-year-old man with persistent severe oropharyngeal ulceration developed a high-grade T-cell lymphoma soon after commencing treatment with cyclosporin A. Using Southern blotting to identify T-cell beta-chain gene rearrangements, evidence of clonal restriction was found both in blood and lymph node DNA samples. Two BamH1 rearranged bands were demonstrated in both samples. In the blood a 16 Kb band predominated, with a weaker 28 kb band. In the lymph node sample this pattern was reversed. The findings suggest that a bi-clonal population of T-lymphocytes or clonal evolution of an existing T-cell monoclone had developed, and that cyclosporin contributed to the emergence of a high-grade T-cell lymphoma.

Antigens, CD↗