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K Thomson

Publications and source records attributed to K Thomson.

At least 19 recordsLinked to original sources
PubMed2006

How can the principles of complexity science be applied to improve the coordination of care for complex pediatric patients?

Clinical and technological advances in medicine have resulted in more patients requiring multidisciplinary care and coordination of services. This is particularly challenging in pediatrics, given the dependency of children. Coordination of care is a key ingredient of quality care; when suboptimal, clinical outcomes and satisfaction can suffer. In this article we view coordination of care through the lens of complexity science in an effort to find new solutions to this healthcare challenge.

Child↗
PubMed2005

Transjugular liver biopsy is a safe and effective intervention to guide management for patients with a congenital bleeding disorder infected with hepatitis C.

The prevalence of hepatitis C virus (HCV) infection in adult patients with a congenital bleeding disorder (CBD) approaches 95% and is a major cause of morbidity and mortality. Histological examination of the liver remains the cornerstone of management decisions in patients without a CBD. The reluctance to perform liver biopsies in patients with a CBD has been a major limitation in the management of these patients. We are currently the only haemophilia centre in Australasia performing liver biopsies in patients with a CBD for the purpose of guiding prognostic and therapeutic decisions. We report here the results of our centre's experience with transjugular liver biopsy (TJLB) in patients with a CBD. An adequate specimen for histological assessment was attained from all of the patients. There were no major complications recorded. Patients were hospitalized for < or = 48 h for haemostasis prophylaxis. The diagnostic specimen obtained from patients was integral in guiding their future management. We suggest that with a coordinated multidisciplinary approach, TJLB can be performed in patients with a CBD.

Adult↗
PubMed2005

Determinants of plasma D-dimer levels in a traveling population.

BACKGROUND: Plasma D-dimer measurement is a widely used diagnostic test for assessing individuals with suspected venous thromboembolism (VTE). Whilst a negative test is helpful in ruling out thrombosis, the significance and determinants of an elevated plasma D-dimer level in otherwise healthy subjects are poorly understood. OBJECTIVES: To determine the association between recognized risk factors for VTE and plasma D-dimer levels in an adult population. SUBJECTS AND METHODS: Blood samples for measurement of plasma D-dimer levels were obtained from 1000 adults aged <70 years who were participating in a study investigating the incidence of VTE in long distance air travellers. The relationship between D-dimer levels and selected risks factors for VTE including thrombophilia status was investigated. RESULTS: The median (Inter-quartile range) D-dimer level was 243 ng mL(-1) (175-345). Multivariate analysis showed that plasma D-dimer levels were positively associated with increasing age, larger body mass index, female gender, the use of hormone therapy, thrombophilia state, and the presence of co-morbid conditions. CONCLUSION: Plasma D-dimer levels vary markedly between individuals and are associated with known risk factors for VTE, including the presence of thrombophilia conditions. The potential role for the measurement of plasma D-dimer as a marker for thrombosis risk requires further investigation.

Age Factors↗
PubMed2004

Obstetric epidurals and chronic adhesive arachnoiditis.

It has been suggested that obstetric epidurals lead to chronic adhesive arachnoiditis (CAA). CAA is a nebulous disease entity with much confusion over its symptomatology. This review outlines the pathological, clinical, and radiological features of the disease. The proposed diagnostic criteria for CAA are: back pain that increases on exertion, with or without leg pain; neurological abnormality on examination; and characteristic MRI findings. Using these criteria, there is evidence to show that epidural or subarachnoid placement of some contrast media, preservatives and possibly vasoconstrictors, may lead to CAA. No evidence was found that the preservative-free, low concentration bupivacaine with opioid mixtures or plain bupivacaine currently used in labour lead to CAA.

Anesthesia, Epidural↗
PubMed2004

Embolization for major lower gastrointestinal haemorrhage: five-year experience.

The management of major lower gastrointestinal haemorrhage has changed dramatically in the last 15 years. Innovations in coaxial catheter technology have allowed the interventional radiologist to reach the small peripheral mesenteric arteries and perform superselective embolization with a variety of agents. The present large series represents the 5-year experience of this technique at the Alfred Hospital, Melbourne, in a patient cohort with a high number of comorbidities. Technical success was achieved in 96% of cases. The clinical symptoms of mesenteric ischaemia developed in four patients after embolization and were managed conservatively in two. The procedure-related mortality was low when compared with the published complication rates for emergency surgery, in this clinical setting.

Adult↗
PubMed2003

Dependence of young female volleyballers' performance on their body build, physical abilities, and psycho-physiological properties.

AIM: The aim of the study was to establish which anthropometric characteristics, physical abilities and psycho-physiological properties determine the success of adolescent female volleyballers at competitions. METHODS: For this purpose we studied 32 female volleyballers aged 13-16 years. The anthropometric examination included 43 measurements, 7 tests of physical fitness, and 4 series of computerised psycho-physiological tests (n=21). The performance of game elements was measured empirically during championship games using the original computer program "Game". RESULTS: The proficiency of performing volleyball elements - serve, reception, feint, block and spike - was calculated by regression models from the 14 anthropometric measurements, 4 physical fitness and 7 psychophysiological test results, which showed significant correlation with proficiency in the game. The predictive power of the models was at least 32% and in average 56%. The anthropometric factor was significant in the performance of all the elements of the game, being most essential (71-83%) for attack, block and feint. Good results in physical ability tests granted success in serve, attack and reception. CONCLUSION: It was possible to predict the efficiency of reception (44%) by endurance, flexibility and speed measuring tests. Medicine ball throwing test was essential for attack (22%). Psycho-physiological tests were significant for the performance of block (98%), attack (80%), feint (60%) and reception (39%).

Adolescent↗
PubMed2001

Deletion of the CD4 silencer element supports a stochastic mechanism of thymocyte lineage commitment.

The mechanism of T cell lineage commitment remains controversial; to examine it we deleted the CD4-silencer element in the germ line of a mouse using a combination of gene targeting and Cre/LoxP-mediated recombination. We found that these mice were unable to extinguish CD4 expression either in immature thymocytes or mature CD8+ cytotoxic T cells (CTLs), which resulted in the development of major histocompatibility complex class II-restricted double-positive CTLs in the periphery. This finding strongly supports a stochastic over an instructive mechanism of coreceptor down-regulation.

Animals↗
PubMed2000

Investigation of the effect of marathon running on leucocyte counts of subjects of different ethnic origins: relevance to the aetiology of ethnic neutropenia.

Healthy subjects of African ancestry, including Afro-Caribbeans, have been observed to have lower total white cell counts and neutrophil counts than healthy Caucasian subjects. The cause of this ethnic neutropenia is unclear. We have previously found no evidence that increased margination of neutrophils is responsible. In this study, we have investigated mobilization of neutrophils from the bone marrow granulocyte reserve by endurance exercise. We investigated subjects of different ethnic origins before and after they had competed in a marathon race. Before the race, the neutrophil counts of Africans/Afro-Caribbeans were significantly lower than those of Caucasians (means 2.49 and 3.21 x 109/l respectively; P = 0.043). After the race, the difference was greater, as was the degree of significance (means 10.21 and 12.33 respectively; P = 0.017). The percentage increment was almost identical whereas the absolute increment was considerably less, although of marginal statistical significance (increment 7.72 and 9. 12 x 109/l respectively; P = 0.10). Similar changes were observed in the monocyte count. Before the race, the difference in the means was of marginal statistical significance (0.35 and 0.41 x 109/l respectively; P = 0.105), whereas after the race the difference was greater and was highly significant (means 0.75 and 1.05 x 109/l respectively; P = 0.001). These observations support the results of our earlier study, both of which suggested that ethnic neutropenia is likely to result from a diminished bone marrow reserve rather than being consequent on altered distribution of neutrophils within the blood stream.

Adult↗
PubMed2000

Iron deficiency alters H- and L-ferritin expression in rat brain.

Ferritin (Ft) H and L subunits are independently regulated proteins with both transcriptional and translational regulation in response to cellular iron levels. While the heterogeneous distribution of ferritin and iron in the brain is now well established, the relative response of each subunit to iron deficiency and iron supplementation, is not well defined. Weanling male Sprague-Dawley rats (n=12 per group) were randomly assigned to an iron deficient (3.5 mg Fe/kg diet), control (35 mg Fe/kg diet) or supplemented (350 mg Fe/kg diet) diet for six weeks. The H-/L-ferritin subunit ratio and mRNA levels were determined. Overall, the protein ratio in control rats of H to L was approximately 45:1 compared to a ratio >60:1 in iron deficiency but the absolute amounts of each subunit varied greatly from one brain region to another. The ratio of H-:L-ferritin mRNA was 6:1 and was not affected by dietary iron deficiency in contrast to a potent effect on mRNA levels in liver. Severe iron deficiency reduced brain ferritin H protein levels significantly in all regions, whereas only ferritin L levels in striatum, substantia nigra and pons were affected by iron deficiency. Supplemental dietary iron increased both ferritin subunits, with the largest increase (50%) in the hippocampus. These data indicate that ferritin H and L subunits within the brain respond differently to iron status and suggest post transcription regulation as a key event.

Animals↗
PubMed2000

Women with learning disabilities: risk behaviours and experiences of the cervical smear test.

This paper reports the findings of a study on the views and experiences of women with learning disabilities regarding the cervical smear test. The experience and opinions of the carers were also taken into account. The study was carried out between 1997 and 1999 in Cambridgeshire. The factors that influenced whether women with a learning disability had a smear test included: sexual activity; number of sexual partners; pregnancy; and a past history of smoking. Women with a learning disability who had a cervical smear test most often experienced pain and difficulty with the procedure. Factors that enable women with a learning disability to undergo a cervical smear test, according to their experiences, will be discussed in this paper. These include: the importance of prolonged preparation; issues surrounding communication; the giving of information; and support from the carers. The implications of these findings for collaborative working between learning disability nurses and primary healthcare professionals in clinical practice are highlighted.

Adult↗
PubMed1999

Detection of T. gondii in tissues of sheep and cattle following oral infection.

It has been reported in the literature that cattle are more resistant to toxoplasmosis than sheep. Congenital disease due to T. gondii infection is rarely reported in cattle whereas the parasite is a major cause of abortion and neonatal mortality in sheep. It is believed that sheep remain chronically infected for life. Undercooked meat from infected sheep is an important source of infection for man. In contrast cattle are thought to harbour fewer parasite tissue cysts which may not persist for the lifetime of the host. Therefore, cattle are believed to pose less of a risk for human infection. In this study we examined the presence of T. gondii within a range of tissues in sheep and cattle at 6 weeks and 6 months following oral infection with 10(3) or 10(5) sporulated oocysts of T. gondii. The presence of parasite was determined by bioassay in mice and using polymerase chain reaction (PCR). The results from this study show that T. gondii was more frequently and consistently detected in sheep, in particular within brain and heart tissues, whereas parasites were not detected in the samples of tissues taken from cattle. T. gondii was more frequently detected in sheep given the higher dose of T. gondii. Examination of tissues at either 6 weeks or 6 months after infection did not appear to affect the distribution of T. gondii. The polymerase chain reaction has more specificity and sensitivity when detecting the presence of T. gondii in large animals than histological detection.

Animals↗
PubMed1998

TCR beta spectratyping in RA: evidence of clonal expansions in peripheral blood lymphocytes.

OBJECTIVE: To compare the TCR beta repertoire of peripheral blood CD8 enriched (CD8+) and depleted (CD8-) T cells in rheumatoid arthritis (RA) patients and controls using CDR3 length analysis (spectratyping). METHODS: CD8+ and CD8- T cells were separated from 14 RA patients and 12 controls, using magnetic beads coated with anti-CD8 monoclonal antibodies. cDNA was prepared as the template for amplification with 22 V beta-C beta primer pairs. The products were resolved by electrophoresis in an ABI373 sequencer using GENESCAN software. Expansions were identified as dominant CDR3 lengths, where the area underlying the corresponding peak exceeded the sum of the areas of the two adjacent peaks. This method was validated by sequencing 10 samples displaying dominant peaks. The expansion frequencies in RA patients and controls were compared using the chi 2 test statistic. RESULTS: Dominant peaks were evident in several V beta families. They were more frequent in RA patients in both the CD8+ subset (RA normalised frequency 10.6; control normalised frequency 8.0; p = 0.03) and the CD8- subset (RA normalised frequency 2.9; control normalised frequency 1.5; p = 0.02). Sequencing of 10 samples exhibiting dominant peaks revealed an unequivocal clonal expansion in nine (90%). CONCLUSIONS: RA patients exhibited a significantly increased frequency of T cell expansions both in the CD8+ and CD8- subsets. This phenomenon may reflect the proliferation of autoreactive cells, a nonspecific expansion of memory T cells in response to pro-inflammatory cytokines or a defect of T cell regulation that predates the onset of RA and may itself predipose to disease.

Adult↗