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Biomedical subjects

A Williams

Publications and source records attributed to A Williams.

At least 19 recordsLinked to original sources
PubMed2007

Immediate hemodynamic effect of the additional use of the SCD EXPRESS Compression System in patients with venous ulcers treated with the four-layer compression bandaging system.

OBJECTIVES: To test the hypothesis that the SCD EXPRESS intermittent pneumatic compression applied in combination with a four-layer bandage in patients with venous ulcers increases popliteal vein volume flow and velocity. DESIGN: Twenty limbs of 18 patients with venous leg ulcers were studied, median age 76 years. The Total Volume Flow (TVF) and the Peak Systolic Velocity (PSV) were recorded in the popliteal vein using duplex ultrasonography. Measurements were made (i) without bandage, (ii) with four layer bandage and (iii) following the application of the SCD Compression System on top of a four-layer bandage for at least 15 minutes. RESULTS: The median VCSS was 17 (range, 12-22) while the median VSDS for reflux was 4.5 (range, 1-7.5). The median TVF was 71 mL/min (inter-quartile range 57-101) without bandage, 112 (IQR 89-148) with four-layer bandage and 291 (IQR 241-392) with the addition of the SCD System (P<.001, Wilcoxon signed ranks test). The median PSV was 8.4 cm/sec (IQR 6.8-14) without bandage, 13 (9.0-19) with four-layer bandage and 27 (21-31) with the addition of the SCD System (P<.001, Wilcoxon signed ranks test). Both TVF and PSV increased slightly with the addition of the four-layer bandage. However, with the addition of the SCD System these parameters increased three fold. CONCLUSIONS: The SCD EXPRESS Compression System accelerates venous flow in the legs of patients with venous ulcers already treated with a four-layer bandage. The combination of four-layer compression with the SCD System on healing venous ulcers needs to be tested by a clinical effectiveness study.

Aged↗
PubMed2006

A multicentre longitudinal observational study of changes in self reported health status in people with Parkinson's disease left untreated at diagnosis.

BACKGROUND: The issue of when to start treatment in Parkinson's disease (PD) remains controversial. Some favour treatment at diagnosis while others opt for a "wait and watch" policy. The effect of the latter policy on the self reported health status of people with PD is unknown. AIMS: To record self reported health status through longitudinal use of a validated PD specific questionnaire (PDQ-39) in untreated PD patients in multiple centres in the UK. To compare patients who were left untreated with those who were offered treatment during follow-up. METHODS: A multicentre, prospective, "real life" observational audit based study addressing patient reported outcomes in relation to self reported health status and other sociodemographic details. RESULTS: 198 untreated PD were assessed over a mean period of 18 months. During two follow-up assessments, the self reported health status scores in all eight domains of the PDQ-39 and the overall PDQ-39 summary index worsened significantly (p<0.01) in patients left untreated. In a comparative group in whom treatment was initiated at or soon after diagnosis, there was a trend towards improvement in self reported health status scores after treatment was started. CONCLUSIONS: This study addresses for the first time self reported health status, an indicator of health related quality of life, in untreated PD. The findings may strengthen the call for re-evaluation of the policy to delay treatment in newly diagnosed patients with PD.

Aged↗
PubMed2006

Orthodontic treatment for deep bite and retroclined upper front teeth in children.

BACKGROUND: Correction of the type of dental problem where the bite is deep and the upper front teeth are retroclined (Class II division 2 malocclusion) may be carried out using different types of orthodontic treatment. However, in severe cases, surgery to the jaws in combination with orthodontics may be required. In growing children, treatment may sometimes be carried out using special upper and lower dental braces (functional appliances) that can be removed from the mouth. In many cases this treatment does not involve taking out any permanent teeth. Often, however, further treatment is needed with fixed braces to get the best result. In other cases, treatment aims to move the upper first permanent molars backwards to provide space for the correction of the front teeth. This may be carried out by applying a force to the teeth and jaws from the back of the head using a head brace (headgear) and transmitting this force to a part of a fixed or removable dental brace. This treatment may or may not involve the removal of permanent teeth. In some cases, neither functional appliances nor headgear are required and treatment may be carried out without extraction of any permanent teeth. Instead of using a headgear, in certain cases, the back teeth are held back in other ways such as with an arch across or in contact with the front of the roof of the mouth which links two bands glued to the back teeth. Often in these cases, two permanent teeth are taken out from the middle of the upper arch (one on each side) to provide room to correct the upper front teeth. It is important for orthodontists to find out whether orthodontic treatment only, carried out without the removal of permanent teeth, in children with a Class II division 2 malocclusion produces a result which is any different from no orthodontic treatment or orthodontic treatment only involving extraction of permanent teeth. OBJECTIVES: To establish whether orthodontic treatment, carried out without the removal of permanent teeth, in children with a Class II division 2 malocclusion, produces a result which is any different from no orthodontic treatment or orthodontic treatment involving removal of permanent teeth. SEARCH STRATEGY: The Cochrane Oral Health Group's Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE were searched. The handsearching of the main international orthodontic journals was updated to April 2006. There were no restrictions with regard to publication status or language of publication. International researchers, likely to be involved in Class II division 2 clinical trials, were contacted to identify any unpublished or ongoing trials. SELECTION CRITERIA: Trials were selected if they met the following criteria: randomised controlled trials (RCTs) and controlled clinical trials (CCTs) of orthodontic treatments to correct deep bite and retroclined upper front teeth in children. DATA COLLECTION AND ANALYSIS: Screening of eligible studies, assessment of the methodological quality of the trials and data extraction were to be conducted in duplicate and independently by two review authors. Results were to be expressed as random-effects models using mean differences for continuous outcomes and risk ratios for dichotomous outcomes with 95% confidence intervals. Heterogeneity was to be investigated including both clinical and methodological factors. MAIN RESULTS: No RCTs or CCTs were identified that assessed the treatment of Class II division 2 malocclusion in children. AUTHORS' CONCLUSIONS: It is not possible to provide any evidence-based guidance to recommend or discourage any type of orthodontic treatment to correct Class II division 2 malocclusion in children.

Child↗
PubMed2006

dGEMRIC as a function of BMI.

OBJECTIVE: Delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) reflects cartilage glycosaminoglycan (GAG) distribution. The technique assumes that the plasma levels of the contrast agent Gd-DTPA(2-) are the same across individuals after intravenous (IV) injection, when dosing by weight. However, adipose tissue has lower extracellular water (ECW) than lean tissue. The aims of this study were to measure (1) plasma Gd-DTPA(2-) levels vs body mass index (BMI), and (2) dGEMRIC vs BMI after correcting for the dose-BMI effect. METHOD: (1) Plasma Gd-DTPA(2-) levels were analyzed at 3-90 min after IV injection per body weight in 24 individuals with BMI between 21.5 and 46.5. (2) dGEMRIC was compared with BMI in 19 asymptomatic volunteers and 23 with osteoarthritis (OA). RESULTS: (1) Plasma Gd-DTPA(2-) kinetics were similar in obese and non-obese groups, however, overall concentration was higher in the obese group. A very obese subject (BMI 45) would have 1.4 times higher Gd-DTPA(2-) concentration than a lean subject (BMI 20), which translates into a bias in dGEMRIC of up to 20%. (2) With dose bias taken into account, dGEMRIC showed no correlation with BMI in asymptomatic knees. In OA knees, unnarrowed femoral compartments demonstrated a negative correlation between dGEMRIC and BMI (R=0.57, P=0.004). No correlation was seen in radiographically narrowed compartments. CONCLUSION: BMI can be a source of dosing bias in dGEMRIC and a correction factor should be considered in cross-sectional studies with a large range of BMI. There is no correlation between dGEMRIC and BMI in asymptomatic knees, but a negative correlation in OA knees.

Adult↗
PubMed2006

Individual and multi-environment combined analyses identify QTLs for morphogenetic and reproductive development traits in white clover (Trifolium repens L.).

White clover (Trifolium repens L.) is a key component legume of temperate pasture agriculture and an important target for molecular marker-assisted plant breeding. A genetic map of white clover has been used to assess genetic control of agronomically important traits that vary in the F2(I.4RxI.5J) mapping family. Phenotypic analysis was performed for a range of vegetative morphogenesis traits (such as leaf area, internode length, plant height and plant spread) and reproductive morphogenesis and development traits (such as flowering date, floral intensity and seed yield), with both spatial and temporal replication. A multi-environment combined analysis (combined analysis) has been performed for traits assessed across multiple experimental datasets in order to identify consistent genetic effects. Quantitative trait locus (QTLs) were detected for the majority of traits, and the locations and magnitudes of QTL effects were compared between individual and combined analyses. This molecular genetic dissection of agronomic traits in white clover provides the basis for equivalent studies in more complex populations, design of marker-assisted selection strategies and comparative genetics with model legume species. Selection for QTLs derived from the combined analysis will permit robust improvement of phenotypic traits over different environments.

Chromosome Mapping↗
PubMed2006

Discovery of a cool planet of 5.5 Earth masses through gravitational microlensing.

In the favoured core-accretion model of formation of planetary systems, solid planetesimals accumulate to build up planetary cores, which then accrete nebular gas if they are sufficiently massive. Around M-dwarf stars (the most common stars in our Galaxy), this model favours the formation of Earth-mass (M(o)) to Neptune-mass planets with orbital radii of 1 to 10 astronomical units (au), which is consistent with the small number of gas giant planets known to orbit M-dwarf host stars. More than 170 extrasolar planets have been discovered with a wide range of masses and orbital periods, but planets of Neptune's mass or less have not hitherto been detected at separations of more than 0.15 au from normal stars. Here we report the discovery of a 5.5(+5.5)(-2.7) M(o) planetary companion at a separation of 2.6+1.5-0.6 au from a 0.22+0.21-0.11 M(o) M-dwarf star, where M(o) refers to a solar mass. (We propose to name it OGLE-2005-BLG-390Lb, indicating a planetary mass companion to the lens star of the microlensing event.) The mass is lower than that of GJ876d (ref. 5), although the error bars overlap. Our detection suggests that such cool, sub-Neptune-mass planets may be more common than gas giant planets, as predicted by the core accretion theory.

Journal Article↗
PubMed2006

Intravesical migration of levonorgestrel-releasing intrauterine system (LNG-IUS) with calculus formation.

The intrauterine contraceptive device (IUD) has been in use for many years as an effective means of birth control. Migration of the device from the uterus to the pelvic cavity is not uncommon and has been reported previously, however intravesical migration and secondary calculus formation is relatively rare. We report a 28-year-old woman in whom an intrauterine contraceptive device (LNG-IUS) migrated from the uterus to the bladder and resulted in stone formation. This case shows that the newer hormone releasing IUDs may also cause bladder perforation.

Adult↗
PubMed2006

Nurse-led clinics reduce severity of childhood atopic eczema: a review of the literature.

BACKGROUND: The increasing prevalence and impact of atopic eczema in children in Western countries such as Australia substantiate the need to evaluate the current management of this illness. It has been well documented that the most important aspects in the management of atopic eczema are to allow adequate time for education and demonstration of treatments. However, current models of healthcare funding restrict the opportunity for patient education during medical consultation times. The contribution of nursing to patient care through nurse-led clinics has significant potential in the management of many common chronic illnesses, although atopic eczema has received minimal attention by researchers to date. OBJECTIVES: To discuss the current clinical management of atopic eczema, and to identify the evidence surrounding the benefits of nurse-led clinics in managing patients with chronic illnesses. METHODS: Systematic searches were undertaken using the Cochrane Library, MedLine, PUBMed and CINAHL from 1995 to 2005. Manual searches of references of retrieved articles identified two additional key studies from 1990 and 1993 which were also included in the review. RESULTS: In total, 22 relevant publications were identified. These included both primary research and descriptive studies that covered the medical management of eczema, patient education and improved patient outcomes. The evidence emerging from the literature indicates that the current management of eczema through doctor-led clinics could be improved, with doctors often lacking the time to offer sufficient patient education to manage chronic illnesses effectively. The literature supports the efficacy of nurse-led clinics in the management of chronic illnesses. The benefits of nurse-led clinics include increased patient satisfaction, longer consultations resulting in improved patient education and similar health outcomes when compared with care from a doctor. No studies were identified comparing nurse-led and doctor-led clinics in the management of eczema. CONCLUSIONS: The most effective way to manage atopic eczema is to provide adequate time for education and demonstration of treatments, which the literature suggests can be achieved through nurse-led clinics. The literature review supports an investigation researching the outcomes of a nurse-led clinic on reducing the severity of eczema in children.

Adolescent↗
PubMed2006

Gene and protein expression of protease-activated receptor 2 in structural and inflammatory cells in the nasal mucosa in seasonal allergic rhinitis.

BACKGROUND: Protease-activated receptor 2 (PAR 2) has been shown to be responsible for trypsin and mast cell tryptase-induced airway inflammation. Here, the present study aimed to explore the expression of PAR 2 in the nasal mucosa of seasonal allergic rhinitis (SAR). METHODS: Study subjects were recruited for the study by medical history, physical examination and laboratory screening tests. Using immunohistochemistry, laser-assisted cell picking and subsequently real-time PCR, nasal mucosa biopsies of SAR patients were investigated for PAR 2 gene and protein expression in complex tissues of the nasal mucosa. RESULTS: Gene and protein expression of PAR 2 was firstly detected in nasal mucosa of SAR patients. The relative gene expression level of PAR 2 was significantly increased in complex tissues of the nasal mucosa of SAR (6.21+/-4.02 vs. controls: 1.38+/-0.86, P=0.004). Moreover, PAR 2 mRNA expression in epithelial cells (SAR: 4.78+/-4.64 vs. controls: 0.84+/-0.61, P=0.003) but not in mucus (SAR: 1.51+/-1.15 vs. controls: 1.35+/-1.02, P=0.78) and endothelial cells (SAR: 1.20+/-0.57 vs. controls: 1.73+/-1.30, P=0.5) was found to be significantly changed in the nasal mucosa in SAR. Using double immunohistochemistry the present study demonstrated that the total numbers of mast cells (P=0.0003) and eosinophils (P=0.03) and the numbers of eosinophils expressing PAR 2 (P=0.006) were significantly elevated in the nasal mucosa of SAR compared with the controls. CONCLUSION: The abundant presence and distribution of gene and protein expression of PAR 2 in different cell types in the nasal mucosa under normal situation, the increased expression of PAR 2 in epithelial cells and the increased number of eosinophils with PAR 2 suggest that PAR 2 may contribute to the pathogenesis of allergic diseases such as SAR.

Adolescent↗
PubMed2006

Intranasal IFNgamma extends passive IgA antibody protection of mice against Mycobacterium tuberculosis lung infection.

Intranasal inoculation of mice with monoclonal IgA against the alpha-crystallin (acr1) antigen can diminish the tuberculous infection in the lungs. As this effect has been observed only over a short-term, we investigated if it could be extended by inoculation of IFNgamma 3 days before infection, and further co-inoculations with IgA, at 2 h before and 2 and 7 days after aerosol infection with Mycobacterium tuberculosis H37Rv. This treatment reduced the lung infection at 4 weeks more than either IgA or IFNgamma alone (i.e. 17-fold, from 4.2 x 10(7) to 2.5 x 10(6) CFU, P = 0.006), accompanied also by lower granulomatous infiltration of the lungs. IFNgamma added prior to infection of mouse peritoneal macrophages with IgA-opsonized bacilli resulted in a synergistic increase of nitric oxide and TNFalpha production and a 2-3 fold decrease in bacterial counts. Our improved results suggest, that combined treatment with IFNgamma and IgA could be developed towards prophylactic treatment of AIDS patients, or as an adjunct to chemotherapy.

Administration, Intranasal↗
PubMed2006

Improving cancer patients' pain: the impact of the hospital specialist palliative care team.

Pain is reported to occur in the majority of patients with advanced cancer and is one of the main reasons for referral to a hospital specialist palliative care team. Yet despite this, there is a paucity of research into the impact the hospital specialist palliative care team has on pain control in patients. A non-equivalent control group design using a quota sample investigated 100 cancer patients who had been admitted to hospital for symptom control. Fifty patients received specialist hospital palliative care team intervention compared with 50 patients receiving traditional care. Outcome was assessed using the Palliative Care Assessment (PACA) tool on three occasions. There was no difference between the groups on the initial assessment and the results indicated that all cancer patients admitted to hospital had a significant improvement in their pain control. However, the patients who had the additional input of the palliative care team demonstrated a statistically significant greater improvement than the control group (P<0.001). Potential explanations are made for the results including the enhanced knowledge and skills of the hospital specialist palliative care team.

Analgesia↗
PubMed2006

Ewing's sarcoma of bone: the detection of specific transcripts in a large, consecutive series of formalin-fixed, decalcified, paraffin-embedded tissue samples using the reverse transcriptase-polymerase chain reaction.

AIMS: (i) To report on the routine use of the reverse transcriptase-polymerase chain reaction (RT-PCR) technique on decalcified or non-decalcified, formalin-fixed, paraffin-embedded tissue (FFPET) for translocation detection, with particular emphasis on improved RNA extraction methodology and the use of PCR primers designed to generate small amplicons. (ii) To report on the relative incidences of translocation types and transcript variants in a large, single institution series of Ewing's sarcoma of bone. METHODS AND RESULTS: Using RT-PCR to detect specific transcript variants, we analysed FFPET from 54 consecutive cases of Ewing's sarcoma of bone. We used 'gold standard' detection methods on corresponding fresh and fresh frozen tissue to validate the technique. We have demonstrated the effective use of RT-PCR on decalcified and non-decalcified FFPET samples for sarcoma-specific translocation detection (96% sensitivity, 100% specificity). Tissue decalcification did not affect the detection rate. The relative incidence of Ewing's sarcoma-specific translocation types and transcript variants was entirely consistent with previously published data. CONCLUSIONS: With equal effectiveness, RT-PCR can be applied to both acid decalcified and non-decalcified FFPET for (Ewing's sarcoma) translocation detection and the technique can be introduced into routine practice in histopathology departments.

Adolescent↗
PubMed2006

Microarray gene expression profiling of a human glioblastoma cell line exposed in vitro to a 1.9 GHz pulse-modulated radiofrequency field.

The widespread use of mobile phones has led to public concerns about the health effects associated with exposure to radiofrequency (RF) fields. The paramount concern of most persons relates to the potential of these fields to cause cancer. Unlike ionizing radiation, RF fields used for mobile telecommunications (800-1900 MHz) do not possess sufficient energy to directly damage DNA. Most rodent bioassay and in vitro genotoxicity/mutation studies have reported that RF fields at non-thermal levels have no direct mutagenic, genotoxic or carcinogenic effects. However, some evidence has suggested that RF fields may cause detectable postexposure changes in gene expression. Therefore, the purpose of this study was to assess the ability of exposure to a 1.9 GHz pulse-modulated RF field for 4 h at specific absorption rates (SARs) of 0.1, 1.0 and 10.0 W/kg to affect global gene expression in U87MG glioblastoma cells. We found no evidence that non-thermal RF fields can affect gene expression in cultured U87MG cells relative to the nonirradiated control groups, whereas exposure to heat shock at 43 degrees C for 1 h up-regulated a number of typical stress-responsive genes in the positive control group. Future studies will assess the effect of RF fields on other cell lines and on gene expression in the mouse brain after in vivo exposure.

Cell Line, Tumor↗
PubMed2005

Discordant plasma and cerebral spinal fluid cytokines/chemokines in relation to HIV-1-associated dementia.

Monocytes and macrophages serve as HIV-1 reservoirs and may indirectly lead to HIV-1-associated dementia via neurotoxic cytokine/chemokine production. It remains unknown if peripheral monocytes and macrophages are responsible for the presence of circulating and cerebral spinal fluid cytokine/chemokine. The purpose of this evaluation was to determine the relationship between inflammatory and chemoattractant cytokine/chemokine in the periphery and the CNS among individuals with HIV-1-associated dementia and normal cognition. To accomplish this, we utilized specimens from the Hawaii Aging with HIV Cohort to assay plasma, cerebral spinal fluid, and cultured peripheral monocyte and macrophage supernatant cytokine/chemokines from individuals with HIV-1-associated dementia and normal cognition by ELISA, relative real-time PCR, and protein macroarrays. To further characterize the activated cells that may be responsible for HIV-1-associated dementia, inverse-PCR was used to identify sites of viral integration. Different mediators of inflammation, and chemoattraction from monocyte and macrophage supernatants, plasma, and cerebral spinal fluid were identified in HIV-1-associated dementia versus normal cognition. The data suggest unique pathways leading to cytokine/chemokine release in the periphery versus the brain region. This may have implications in delineating a cause and effect in HIV-1-associated dementia pathogenesis.

AIDS Dementia Complex↗
PubMed2005

Single-nucleotide polymorphisms in the C-reactive protein (CRP) gene promoter that affect transcription factor binding, alter transcriptional activity, and associate with differences in baseline serum CRP level.

To investigate whether functional polymorphisms exist in the C-reactive protein (CRP) gene, i.e., ones that contribute directly to differences in baseline CRP among individuals, we sequenced a 1,156-nucleotide-long stretch of the CRP gene promoter in 287 ostensibly healthy people. We identified two single-nucleotide polymorphisms (SNPs), a bi-allelic one at nucleotide -409 (G-->A), and a tri-allelic one at -390 (C-->T-->A), both resident within the hexameric core of transcription factor binding E-box elements. Electrophoretic mobility shift assays confirmed that the SNP within the sequence (-412)CACGTG(-407) (E-box 1) modulates transcription factor binding, and that the one within (-394)CACTTG(-389) (E-box 2) supports transcription factor binding only when the -390 T allele is present. The commonest of four E-box 1/E-box 2 haplotypes (-409G/-390T) identified in the population supported highest promoter activity in luciferase reporter assays, and the rarest one (-409A/-390T) supported the least. Importantly, serum CRP in people with these haplotypes reproduced this rank order, i.e., people with the -409G/-390T haplotype had the highest baseline serum CRP (mean +/- SEM 10.9 +/- 2.25 microg/ml) and people with the -409A/-390T haplotype had the lowest (5.01 +/- 1.56 microg/ml). Furthermore, haplotype-associated differences in baseline CRP were not due to differences in age, sex, or race, and were still apparent in people with no history of smoking. At least two other SNPs in the CRP promoter lie within E-box elements (-198 C-->T, E-box 4, and -861 T-->C, E-box 3), indicating that not only is the quality of E-box sites in CRP a major determinant of baseline CRP level, but also that the number of E-boxes may be important. These data confirm that the CRP promoter does encode functional polymorphisms, which should be considered when baseline CRP is being used as an indicator of clinical outcome. Ultimately, development of genetic tests to screen for CRP expression variants could allow categorization of healthy people into groups at high versus low future risk of inflammatory disease.

Adult↗
PubMed2005

Tibio-femoral movement in the living knee. A study of weight bearing and non-weight bearing knee kinematics using 'interventional' MRI.

The aim of this study was to image tibio-femoral movement during flexion in the living knee. Ten loaded male Caucasian knees were initially studied using MRI, and the relative tibio-femoral motions, through the full flexion arc in neutral tibial rotation, were measured. On knee flexion from hyperextension to 120 degrees , the lateral femoral condyle moved posteriorly 22 mm. From 120 degrees to full squatting there was another 10 mm of posterior translation, with the lateral femoral condyle appearing almost to sublux posteriorly. The medial femoral condyle demonstrated minimal posterior translation until 120 degrees . Thereafter, it moved 9 mm posteriorly to lie on the superior surface of the medial meniscal posterior horn. Thus, during flexion of the knee to 120 degrees , the femur rotated externally through an angle of 20 degrees . However, on flexion beyond 120 degrees , both femoral condyles moved posteriorly to a similar degree. The second part of this study investigated the effect of gender, side, load and longitudinal rotation. The pattern of relative tibio-femoral movement during knee flexion appears to be independent of gender and side. Femoral external rotation (or tibial internal rotation) occurs with knee flexion under loaded and unloaded conditions, but the magnitude of rotation is greater and occurs earlier on weight bearing. With flexion plus tibial internal rotation, the pattern of movement follows that in neutral. With flexion in tibial external rotation, the lateral femoral condyle adopts a more anterior position relative to the tibia and, particularly in the non-weight bearing knee, much of the femoral external rotation that occurs with flexion is reversed.

Adult↗