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Biomedical subjects

S Mitchell

Publications and source records attributed to S Mitchell.

At least 19 recordsLinked to original sources
PubMed2006

Estrogen as treatment of hemorrhagic cystitis in children and adolescents undergoing bone marrow transplantation.

Hemorrhagic cystitis (HC) after allogeneic hematopoietic stem cell transplantation (HSCT) can cause significant morbidity and mortality. Previous reports have suggested a role for estrogen in the control of HC in adult patients. Here, we describe the clinical courses of 10 children and adolescents treated with estrogen for HC following HSCT. Eight patients (80%) experienced a significant improvement in their hematuria following the commencement of therapy, with six (60%) undergoing resolution of macroscopic hematuria, without any recurrences. The treatment was well tolerated by the majority of patients, with only one patient needing to interrupt treatment (hepatotoxicity). We conclude that estrogen is well tolerated and often effective, and should be considered as an adjunctive treatment option in children and adolescents with HC following HSCT.

Adolescent↗
PubMed2006

Quantitative trait loci associated with parasitic infection in Scottish blackface sheep.

This study aimed to identify quantitative trait loci associated with endoparasitic infection in Scottish Blackface sheep. Data were collected from 789 animals over a 3-year period. All of the animals were continually exposed to a mixed nematode infection by grazing. Faecal samples were collected in August, September and October each year at ca. 16, 20 and 24 weeks of age; Nematodirus spp. eggs were counted separately from the other species of nematodes. Blood samples were collected in October from which immunoglobulin A (IgA) activity was measured and DNA was extracted for genotyping. In total, 139 Microsatellite markers were genotyped across eight chromosomal regions (chromosomes 1, 2, 3, 5, 14, 18, 20 and 21) in the sires and progeny were genotyped for the markers that were polymorphic in their sire. Evidence was found for quantitative trait loci (QTL) on chromosomes 2, 3, 14 and 20. QTL associated with specific IgA activity were identified in chromosomes 3 and 20, in regions close to IFNG (chromosome 3) and the MHC (chromosome 20). QTL associated with Nematodirus FEC were identified on chromosomes 2, 3 and 14. Lastly, QTL associated with non-Nematodirus Strongyle FEC were identified on chromosomes 3 and 20. This study has shown that some aspects of host resistance to gastrointestinal parasites are under strong genetic control, therefore these QTL could be utilised in a marker-assisted selection scheme to increase host resistance to gastrointestinal parasites.

Animals↗
PubMed2005

Variation among faecal egg counts following natural nematode infection in Scottish Blackface lambs.

Faecal egg counts were examined in 2 flocks of naturally infected Scottish Blackface sheep in southern and central Scotland. The distribution of mean counts was right skewed and similar to a gamma distribution. The counts varied with month, with mean counts rising from May to July, then falling but rising again in October, although data within each year did not always show such a clear pattern. There was no significant difference in mean egg count between the 2 farms examined. The distribution of egg count variances was also right skewed and conformed to a gamma distribution. There was a strong relationship between the mean and the variance for each population, implying that variation among populations in variances largely mirrored variation in mean egg counts. Populations with high mean egg counts and variances did not necessarily have more adult nematodes but had a greater number of adult nematodes from species other than Teladorsagia circumcincta, particularly Cooperia spp., Trichostrongylus axei and Trichostrongylus vitrinus. The contribution of different parasite species to the egg count explains the relatively poor and inconsistent fit of the negative binomial distribution to faecal egg counts in lambs.

Albendazole↗
PubMed2005

Problem-based learning: is anatomy a casualty?

INTRODUCTION: The teaching of medical anatomy is changing. Medical schools worldwide are moving away from dissection and lectures to a more integrated course, where basic science and clinical skills are taught simultaneously. Medical students on these integrated courses have reported a lack of confidence in their basic science knowledge, especially concerning anatomy. Our aim was to perform a randomised controlled trial (RCT) to compare anatomical knowledge of two groups of second-year medical students, the first group taught on a traditional course, the second on an integrated course. MATERIALS AND METHODS: Testing was done using a Questionnaire in a "True/False" format. There were 80 students in each group. There was no penalty for an incorrect answer. The test was performed under examination conditions. Papers were marked under blind conditions. Results were analysed using a Student's t test analysis. RESULTS: Those students taught on a traditional course exhibited a significantly higher level of basic anatomical knowledge (p<0.001) than those taught on an integrated course. The students taught on an integrated course showed a much greater range of results. CONCLUSIONS: Students taught on a traditional course have a higher level of anatomical knowledge than those taught on an integrated course. Our results differ from previous studies done in Europe which show no difference between the courses.

Anatomy↗
PubMed2005

A new antihistamine levocetirizine inhibits eosinophil adhesion to vascular cell adhesion molecule-1 under flow conditions.

BACKGROUND: We previously demonstrated that low concentrations of a new antihistamine levocetirizine inhibited eosinophil transmigration through human microvascular endothelial cells. OBJECTIVE: Here, the inhibitory effect of levocetirizine on eosinophil adhesion to recombinant human vascular cell adhesion molecule-1 (rhVCAM)-1 was examined under conditions of shear stress using an in vitro model of the post-capillary venules. METHODS: Eosinophils isolated from normal subjects were pre-incubated with a concentration range of levocetirizine (10(-6)-10(-10) m) or negative dilution control. Resting or granulocyte macrophage-colony stimulating factor (GM-CSF)-stimulated cells were pumped through rhVCAM-1 (10 microg/mL) coated capillary tubes using a microfluidic syringe pump at a precise and constant flow rate (1 dyn/cm(2)). Images of rolling and firmly adherent eosinophils were captured using real-time video microscopy. RESULTS: Levocetirizine significantly inhibited resting eosinophil adhesion to rhVCAM-1 with maximal effect at 10(-8) M with an EC(50) of 10(-9) m. Levocetirizine almost abolished resting eosinophil adhesion by the 15 min time-point. GM-CSF significantly enhanced eosinophil adhesion and their ability to flatten on rhVCAM-1. Both phenomena were inhibited by levocetirizine in a dose-dependent manner, at both 5 and 15 min (optimal concentration of 10(-8) m with an EC(50) of 10(-9) m). Real-time imaging revealed that the effect of levocetirizine on post-adhesion behaviour (detachment, flatness) contributed to its inhibitory action on eosinophil adhesion to rhVCAM-1. In contrast, very late antigen (VLA)-4 mAb inhibited eosinophil adhesion to rhVCAM-1 from the earliest time-points. CONCLUSION: Physiologically relevant concentrations of levocetirizine inhibit resting and GM-CSF-stimulated firm eosinophil adhesion to rhVCAM-1 under flow conditions.

Antibodies, Monoclonal↗
PubMed2004

The relationship between IgA activity against 4th-stage larvae and density-dependent effects on the number of 4th-stage larvae of Teladorsagia circumcincta in naturally infected sheep.

The number of Teladorsagia circumcincta 4th-stage larvae in naturally infected lambs from a single farm varied among lambs and among different years. Within each year the distribution of 4th-stage larvae among lambs was similar to that expected from a negative binomial distribution. The ratio of 4th-stage larvae to adult T. circumcincta was low in two years with a low mean intensity of infection but high in two years with a higher mean intensity of infection. The negative binomial distribution is defined by the mean and by k, a parameter that measures dispersion; k was low when mean infection intensity was low but higher when mean infection intensity was high. As k is an inverse index of overdispersion this indicated that the distribution of 4th-stage larvae was more overdispersed at low levels of infection. In a combined analysis, the number of adult T. circumcincta and the plasma IgA activity against 4th-stage larvae were both associated with increased numbers of 4th-stage larvae. There was a statistical interaction between the number of adults and IgA activity that moderated their combined effect.

Abomasum↗
PubMed2004

The effect of shaft flexibility on junior golfers' performance.

The aims of this study were to examine the effect of shaft flexibility on the performance of junior golfers and to determine whether there is a relationship between golfers' physical characteristics (16 anthropometric measures, age, experience, strength), performance and shaft flexibility. We assessed the performance of 30 male golfers, aged 7-10 years, with three 7-iron golf clubs of different shaft flexibility at a driving range. The performance parameters measured for equipment evaluation were ball distance achieved, shot dispersion and impact position of the ball on the clubface. The results suggest that there is no particular shaft flex suitable for the age group considered and that experience, strength and arm span are the significant factors when selecting optimal shaft flexibility for children.

Arm↗
PubMed2004

Tobacco use in popular movies during the past decade.

OBJECTIVE: The top 50 commercially successful films released per year from 1991 to 2000 were content coded to assess trends in tobacco use over time and attributes of films predictive of higher smoking rates. DESIGN: This observational study used media content analysis methods to generate data about tobacco use depictions in films studied (n = 497). Films are the basic unit of analysis. Once films were coded and preliminary analysis completed, outcome data were transformed to approximate multivariate normality before being analysed with general linear models and longitudinal mixed method regression methods. MAIN OUTCOME MEASURES: Tobacco use per minute of film was the main outcome measure used. Predictor variables include attributes of films and actors. Tobacco use was defined as any cigarette, cigar, and chewing tobacco use as well as the display of smoke and cigarette paraphernalia such as ashtrays, brand names, or logos within frames of films reviewed. RESULTS: Smoking rates in the top films fluctuated yearly over the decade with an overall modest downward trend (p < 0.005), with the exception of R rated films where rates went up. CONCLUSIONS: The decrease in smoking rates found in films in the past decade is modest given extensive efforts to educate the entertainment industry on this issue over the past decade. Monitoring, education, advocacy, and policy change to bring tobacco depiction rates down further should continue.

Age Factors↗
PubMed2004

Exploring knowledge and attitudes about emergency contraceptive pills among university students in Jamaica. A qualitative approach.

Emergency contraceptive pills (ECPs) are an important option for university students who may be at high risk for unplanned pregnancies. In the Caribbean, little research has been carried out on university student's knowledge and opinions of this method. This study uses qualitative methodology to explore knowledge and opinions on ECPs among university students attending The University of the West Indies (UWI) Mona campus. We conducted eight focus groups (n = 71) with female and male university students at The University of the West Indies, Kingston, Jamaica, in March 2000. The group discussions lasted approximately two hours. We tape-recorded discussions and then transcribed and analyzed them by coding responses according to themes. General knowledge of ECPs was high, but students lacked specific information about the method such as its time frame and its mechanism of action. Most students supported the method, especially after learning correct information. However, several students were concerned about its side effects and the potential for abuse or irresponsible use by young adults. Although the university students in this study lacked detailed information about ECPs, their opinion toward the method was favourable. We suggest further research to investigate the prevalence of misinformation about the method among other groups of Jamaicans.

Adolescent↗
PubMed2003

Microsatellite identification and characterization in peanut ( A. hypogaea L.).

A major constraint to the application of biotechnology to the improvement of the allotetraploid peanut, or groundnut ( Arachis hypogaea L.), has been the paucity of polymorphism among germplasm lines using biochemical (seed proteins, isozymes) and DNA markers (RFLPs and RAPDs). Six sequence-tagged microsatellite (STMS) markers were previously available that revealed polymorphism in cultivated peanut. Here, we identify and characterize 110 STMS markers that reveal genetic variation in a diverse array of 24 peanut landraces. The simple-sequence repeats (SSRs) were identified with a probe of two 27648-clone genomic libraries: one constructed using PstI and the other using Sau3AI/ BamHI. The most frequent, repeat motifs identified were ATT and GA, which represented 29% and 28%, respectively, of all SSRs identified. These were followed by AT, CTT, and GT. Of the amplifiable primers, 81% of ATT and 70.8% of GA repeats were polymorphic in the cultivated peanut test array. The repeat motif AT showed the maximum number of alleles per locus (5.7). Motifs ATT, GT, and GA had a mean number of alleles per locus of 4.8, 3.8, and 3.6, respectively. The high mean number of alleles per polymorphic locus, combined with their relative frequency in the genome and amenability to probing, make ATT and GA the most useful and appropriate motifs to target to generate further SSR markers for peanut.

Agriculture↗
PubMed2003

Clinical assessment of a generic DNA amplification assay for the identification of respiratory adenovirus infections.

BACKGROUND: respiratory adenoviruses are common, often resulting in serious sporadic and epidemic infections and impaired immunity can dramatically increase their severity. They are now thought capable of establishing latency. Diagnosis by culture is slow while direct antigen detection by immunofluorescence lacks sensitivity. Molecular diagnosis can be both rapid and sensitive but the genetic heterogeneity of adenoviruses poses problems. OBJECTIVES: to design a generic adenovirus nested polymerase chain amplification assay designed to be capable of detecting all respiratory adenoviruses. This was achieved through optimised thermal cycling and the development of a generic degenerate primer set targeting the adenovirus hexon gene. STUDY DESIGN: this was a cross-sectional study on 172 respiratory specimens from hospital-based patients, and one from a general practice, in Northern Ireland. A comparison was made between the amplification assay, virus culture and immunofluorescence. RESULTS: the nested polymerase chain reaction (nPCR) assay had a generic capacity for adenovirus detection and an analytical sensitivity of 6.4x10(2) copies/ml. Using an expanded gold standard (defined as a true positive or a true negative where a specimen was positive or negative by at least two of the study assays, respectively), PCR had a clinical sensitivity and specificity of 46/46 (100%) and 15/126 (91.3%), respectively. Patients with acute respiratory adenovirus infections were more likely to be male (chi(2), p=0.005) and to present with a fever (chi(2), p=0.02) than patients diagnosed with another respiratory virus. Co-infection was identified in 12/172 patients. CONCLUSIONS: the nested amplification assay proved highly sensitive in both the analytical and clinical settings for the detection of respiratory adenovirus infections.

Adenovirus Infections, Human↗
PubMed2003

Pain tolerance in upper limb disorders: findings from a community survey.

AIMS: To test the hypothesis that non-specific upper limb pain arises from altered pain perception with reduced tolerance of sensory stimuli. METHODS: Subjects undergoing clinical examination as part of a community based survey of upper limb disorders were invited to return for an assessment of pain tolerance. A standardised algorithm was used to classify the 94 participants according to whether they had specific upper limb disorders (n = 22), non-specific arm pain (n = 15), or no arm pain (n = 57). Pain tolerance was assessed at three anatomical sites in each arm in response to electrocutaneous stimulation with alternating currents up to a maximum of 10 mA at three frequencies (5, 250, and 2,000 Hz). A proportional odds model was used to compare pain tolerance thresholds according to sex, age, and diagnosis. RESULTS: Women were less tolerant of pain than men (OR 0.13) and tolerance also declined with age (OR for one year increase in age 0.97). After allowance for sex and age, there was no indication that pain tolerance was lower in subjects with non-specific arm pain than in those with specific upper limb disorders or those who had no arm pain. CONCLUSIONS: The study hypothesis was not supported. However, before the hypothesis is dismissed, it should be tested further in patients with more severe and disabling arm pain.

Adult↗