Biomedical subjects

M Bailey

Publications and source records attributed to M Bailey.

At least 37 records · Page 2Linked to original sources

PubMed2005

Host immune reactions and worm kinetics during the expulsion of Ascaris suum in pigs.

Pigs single inoculated with Ascaris suum eggs expel the majority of larvae between days 14 and 21 post inoculation (p.i.), but the role of the immune system in expulsion is unclear. To investigate the dynamics of immune responses before, during and after the expulsion of A. suum larvae, pigs inoculated with 10 000 A. suum eggs were sequentially necropsied. Ascaris suum gradually moved distally from days 10-14 p.i. and only a few larvae were left by day 21 p.i. Pronounced increases in mucosal A. suum-specific IgA antibody secreting cells (ASCs) were already found by day 10 p.i. especially in the proximal jejunum, while only small increases in parasite-specific IgM ASCs were observed by day 21 p.i. in both proximal and distal jejunum. No mucosal IgG ASC responses could be detected. Increases in systemic A. suum-specific IgG1, IgM and to a lesser extent IgA antibodies were observed, while IgG2 remained almost unchanged. The levels of eosinophils and mast cells in the small intestinal mucosa did not change throughout infection. The results demonstrate that both systemic and mucosal A. suum-specific effector mechanisms are strongly stimulated in A. suum single infections and indicate that mucosal IgA may be an important mediator in the expulsion of A. suum.

Animals↗

PubMed2005

Australia-wide comparison of intensity modulated radiation therapy prostate plans.

The aim of this study was to investigate the ability of Australian centres to produce high-dose intensity modulated radiation therapy (IMRT) prostate plans, and to compare the planning parameters and resultant dose distributions. Five Australian radiation therapy departments were invited to participate. Each centre received an identical 5 mm-slice CT data set complete with contours of the prostate, seminal vesicles, rectum, bladder, femoral heads and body outline. The planning team was asked to produce the best plan possible, using published Memorial Sloan-Kettering Cancer Centre prescription and dose constraints. Three centres submitted plans for evaluation. All plans covered the planning target volume adequately; however, only one plan met all the critical organ dose constraints. Although the planning parameters, beam arrangements and planning systems were different for each centre, the resulting plans were similar. In Australia, IMRT for prostate cancer is in the early stages of implementation, with routine use limited to a few centres.

Australia↗

PubMed2005

Intestinal adaptation after massive intestinal resection.

Patients with short bowel syndrome require long term parenteral nutrition support. However, after massive intestinal resection the intestine undergoes adaptation and nutritional autonomy may be obtained. Given that the complications of parenteral nutrition may be life threatening or result in treatment failure and the need for intestinal transplantation, a more attractive option is to wean patients off nutrition support by optimising the adaptive process. The article examines the evidence that after extensive small bowel resection adaptation occurs in humans and focuses on the factors that influence adaptation and the strategies that have been used to optimise this process. The review is based on an English language Medline search with secondary references obtained from key articles. There is evidence that adaptation occurs in humans. Adaptation is a complex process that results in response to nutrient and non-nutrient stimuli. Successful and reproducible strategies to improve adaptation remain elusive despite an abundance of experimental data. Nevertheless given the low patient survival and quality of life associated with other treatments for irreversible intestinal failure it is imperative that clinical research continues into the optimisation of the adaptation.

Adaptation, Physiological↗

PubMed2005

Reduced bone density in cystic fibrosis: DeltaF508 mutation is an independent risk factor.

The aim of this cross-sectional study was to determine the prevalence and identify determinants of reduced bone mineral density (BMD) in adults with cystic fibrosis (CF). Adults (88) with CF (mean+/-SD age 29.9+/-7.7 yrs; forced expiratory volume in one second (FEV1) 58.2+/-21.5% of the predicted value) were studied. BMD at the lumbar spine (LS) and femoral neck (FN) and body composition were measured using dual-energy X-ray absorptiometry. Blood and urine were analysed for hormones, bone turnover markers, and the cytokines tumour necrosis factor-alpha, and interleukin-6 and -1beta. FEV1 (% pred); CF genotype; malnutrition; history of growth, development or weight gain delays; and corticosteroid use were analysed. BMD Z-scores were -0.58+/-1.30 (mean+/-SD) at the LS and -0.24+/-1.19 at the FN. Z-scores of <-2.0 were found in 17% of subjects. Subjects who were homozygous or heterozygous for the DeltaF508 mutation exhibited significantly lower Z-scores than those with no DeltaF508 allele. Multiple linear regression showed that the DeltaF508 genotype and male sex were independently associated with lower BMD at both sites. Other factors also independently associated with lower BMD included malnutrition, lower 25-hydroxyvitamin D level, lower fat-free mass and lower FEV1 (% pred). In conclusion, reduced bone mineral density in cystic fibrosis is associated with a number of factors, including DeltaF508 genotype, male sex, greater lung disease severity and malnutrition.

Adult↗

PubMed2004

A systematic review of case-control studies of human papillomavirus infection in laryngeal squamous cell carcinoma.

A role for human papillomavirus (HPV) has been suggested in laryngeal squamous cell carcinoma (LSCC). In order to quantitate the available evidence, we reviewed studies examining the risk of laryngeal cancer-associated HPV. PubMed was searched for case-control studies conducted worldwide and published in any language since 1966. Relevant papers were hand-searched and cross-referenced. Six studies met the inclusion criteria. The studies are heterogeneous in the methods used to harvest tissue samples and techniques for detecting the virus within the tissue. HPV-16 positivity among cases ranged from 2.7% to 46.9% and 0-5.7% among controls. Two studies showed a significantly increased risk of LSCC if HPV-16 was present (OR 18.5, 95% CI 2.2-154.8, OR 2.6, 95% CI 1.1-6.0). An increased risk was also observed for glottic versus supraglottic cancer in one study (OR 9.69, 95% CI 1.47-64.04). The direction of effect is towards an increase in risk of LSCC in people with evidence of HPV-16 infection. There is marked heterogeneity in the methods used to detect the virus and frequency with which it is detected. An adequately powered study using a reliable detection technique is required to confirm and quantify this risk and to examine effect modification.

Carcinoma, Squamous Cell↗

PubMed2004

Febrile adults presenting to the emergency department: outcomes and markers of serious illness.

OBJECTIVES: To determine outcomes and markers of serious illness for febrile patients presenting to an adult emergency department. METHODS: A prospective cohort study of patients presenting to the emergency department with a temperature >or=38 degrees C. Medical staff obtained demographic data and risk factor profiles while assessing each febrile patient. All were followed up to determine death, admission to intensive care, length of stay in hospital, or subsequent admission to hospital within 30 days. Univariate and multivariate analysis determined which factors were markers of serious illness. RESULTS: For febrile adults admitted to hospital 3.0% died, 6.1% were admitted to intensive care, median length of stay in hospital was 7.2 days. Independent risk factors were-death: age (OR = 1.04), respiratory rate (OR = 1.06), white cell count (OR = 1.02), cardiac disease (OR = 3.3), and jaundice (OR = 21.4). Admission to intensive care: respiratory rate (OR = 1.1), pulse rate (OR = 1.03), and jaundice (OR = 5.1). Increased length of hospital stay: age (p<0.01), jaundice (p<0.01), respiratory rate (p = 0.01), focal neurological signs (p = 0.01), and changed mental state (p = 0.04). For febrile adults sent home 7.9% required admission to hospital within 30 days. Risk factors were respiratory rate (OR = 1.2), being female (OR = 5.36), malignancy (OR = 15.3), and cardiac disease (OR = 19.7). Initially having no focus of infection was protective (OR = 0.13). No febrile patient sent home from the emergency department died or required admission to intensive care. CONCLUSIONS: Few febrile adults presenting to the emergency department suffer an adverse outcome suggesting effective risk stratification is occurring. The identification of factors associated with adverse events may further improve this process.

Adult↗

PubMed2004

Increased long-term mortality in heart failure due to sleep apnoea is not yet proven.

Previous small-scale studies of the effect of sleep-disordered breathing (SDB) on prognosis in congestive heart failure (CHF) are either lacking or conflicting. The aim of this study was to assess the impact of the presence and type of SDB on mortality in a patient group with severe CHF referred to a specialised heart failure centre. Out of 78 patients ((mean +/- SD) 53 +/- 9 yrs, left ventricular ejection fraction 19.9 +/- 7.2% and pulmonary capillary wedge pressure 16.5 +/- 8.3 mmHg) followed-up over a median period of 52 months, 29% had no apnoea (CHF-N), 28% had obstructive sleep apnoea (CHF-OSA) and 42% had central sleep apnoea (CHF-CSA). At 52 months, their overall mortality was 40%, and combined mortality and transplantation was 72%. Mortality rates were similar between the three apnoea groups. Survivors had a similar prevalence of SDB (71%) as the nonsurvivors (70%). Although a significant increase in mortality was evident at 500 days in those patients with either CHF-SDB or CHF-CSA as compared with CHF-N, this was not significant at final follow-up (52 months) using Kaplan Meier analysis. Multivariate analysis identified transplantation but not SDB type or severity as a significant predictor of survival. In conclusion, sleep-disordered breathing impacts upon early (500 day), but not long-term (52 month), mortality in a specialised heart failure centre.

Adult↗

PubMed2003

A genome-screen of a large twin cohort reveals linkage for quantitative ultrasound of the calcaneus to 2q33-37 and 4q12-21.

UNLABELLED: A genome-wide screen was performed on a large cohort of dizygous twin pairs to identify regions of the genome that contain QTL for QUS of bone. Suggestive linkage of QUS parameters to 2q33-37 and 4q12-21 highlighted these regions as potentially important for studies of genes that regulate bone. INTRODUCTION: The genetics of osteoporotic fracture is only partly explained by bone mineral density (BMD). Quantitative ultrasound (QUS) of the calcaneus can also be used for independent clinical assessment of osteoporotic fracture risk. Two specific indices are derived from this assessment: broadband ultrasound attenuation (BUA) and velocity of sound (VOS). Both parameters provide information on fracture risk; however, BUA has been studied more extensively and may be favored because it is thought to have a stronger predictive value for osteoporotic fracture and incorporates aspects of trabecular structure and bone quality as well as BMD. Studies of QUS in twins have shown that both derived parameters are under substantial genetic control, independent of BMD. MATERIALS AND METHODS: To identify regions of the genome that contain quantitative trait loci (QTL) for QUS of bone, we performed a genome-wide screen on a large cohort of dizygous twin pairs. Unselected female dizygous twins from 1067 pedigrees from the St Thomas' UK Adult Twin Registry were genome scanned (737 highly polymorphic microsatellite markers). Multipoint linkage analyses provided maximum evidence of linkage for BUA (LOD 2.1-5.1) to 2q33-37. Linkage for VOS (LOD 2.2-3.4) was maximal at 4q12-21. Potential evidence of linkage in the cohort indicated five other possible locations of QTL (LOD > 2.0) relevant to bone density or structure on chromosomes 1, 2, 13, 14, and X. RESULTS AND CONCLUSIONS: This study has identified eight genomic locations with linkage of LOD > 2.0. This data should be of value in assisting researchers to localize genes that regulate bone mass and microstructure. These results should complement genome screens of BMD and bone structure and serve to enable further targeted positional candidate and positional cloning studies to advance our understanding of genetic control of bone quality and risk of fracture.

Adolescent↗

PubMed2003

Impact of increasing parenteral protein loads on amino acid levels and balance in critically ill anuric patients on continuous renal replacement therapy.

OBJECTIVES: We wanted to establish optimum protein and glucose intakes during total parenteral nutrition by using a constant caloric but changing protein intake in critically ill, ventilated, anuric patients on continuous renal replacement therapy and measuring amino acid and glucose losses across the hemofilter. METHODS: Eleven consecutive, critically ill patients (eight male, age, 43.5 +/- 21.8 y; Acute Physiology and Chronic Health Evaluation II score, 20.5 +/- 7.0; Acute Physiology and Chronic Health Evaluation risk of death: 36.5% +/- 23.0 and 6 +/- 1 impaired organ systems) entered this study. Patients were fed by continuous infusion of a total parenteral mixture consisting of Synthamin (a mixture of essential and non-essential amino acids), 50% dextrose, and intralipid (long-chain triglycerides) to meet caloric requirements as predicted by Schofield's equation corrected by stress factors. The amount of protein infused was varied (1 to 2.5 g. kg(-1). d(-1)) by increments of 0.25 g. kg(-1). d(-1). Patients were stabilized on each feeding regimen for at least 24 h before paired samples of blood and dialysate were taken for amino acid and glucose measurements. Continuous renal replacement therapy was performed by using a blood pump with a blood flow of 100 to 175 mL/min. Dialysate was pumped in and out counter-currently to the blood flow at 2 L/h. A biocompatible polyacrylonitrile hemofilter was used in all cases. RESULTS: With protein intakes below 2.5 g. kg(-1). d(-1), blood levels of 14% to 57% of the measured amino acids were below the lower limits of the normal range. At 2.5 g. kg(-1). d(-1), all measured amino acids were within the normal range. Amino acid balance became more positive as protein input increased (P = 0.0001). Glucose and amino acid losses were dependent on blood concentration. Overall, 17% (range, 13% to 24%) of infused amino acids and 4% of infused glucose were lost in the dialysate. CONCLUSIONS: This study of critically ill, ventilated, anuric patients on continuous renal replacement therapy suggested that increases in protein and glucose are required to account for the increased losses across the hemofilter. A protein intake of 2.5 g. kg(-1). d(-1) appeared to optimize nitrogen balance and correct amino acid deficiencies.

Adult↗

PubMed2003

Treatment and outcome of 104 hospitalized patients with legionnaires' disease.

BACKGROUND: Large outbreaks of Legionella pneumonia are rare, but when they occur provide an opportunity to assess predictors of mortality and efficacy of drug therapy. Although erythromycin has been the treatment of choice for many years, newer antimicrobials with increased activity against Legionella are available. A large outbreak of legionnaires' disease associated with the Melbourne Aquarium occurred in April 2000. AIM: To describe the patterns and impact of Legionella therapy, and predictors of outcome in a large group of hospitalized patients with legionnaires' disease. METHODS: A 6-month retrospective audit of hospitalized patients with proven legionnaires' disease around the time of the Melbourne Aquarium outbreak was conducted. Statistical analysis was performed using SAS version 8.0 (SAS Institute Inc., NC, USA). RESULTS: Data were obtained on 104 patients (71 aquarium related, 33 not related). There were six deaths (mortality rate 5.8%), three of which were attributable directly to progressive legionnaires' disease. The major predictors of death were pre-existing cardiac failure (P = 0.0035) and renal disease (P = 0.026). Erythro-mycin is still the most commonly used antibiotic (80% received i.v. erythromycin) with clinicians prescribing more than one active Legionella drug in the majority of cases (76%). Choice of initial antibiotic therapy did not statistically affect outcome as measured by death, length of hospital stay or time to defervescence, although there was a trend towards improved survival with i.v. erythromycin (P = 0.063). Intravenous erythromycin was associated with a 19% rate of phlebitis, whereas side-effects from other antibiotics were uncommon. CONCLUSION: The most commonly used Legionella therapy in Australia remains erythromycin. This continues to be an effective agent, however, side-effects are common.

Adult↗

PubMed2003

Lessons learned from interlaboratory comparisons of bioassay data interpretation.

When a set of bioassay data is given to two different dosimetrists, it is likely that these data will be interpreted differently, that different methods and dosimetric models will be applied and therefore different numerical values will be obtained. Thus, it is important for laboratories dealing with internal dosimetry to undergo performance testing procedures such as interlaboratory comparisons of bioassay data interpretation. Several intercomparison exercises have already been organised at national and international levels. The largest one so far was the 3rd European Intercomparison Exercise on Internal Dose Assessment, which has been organised in the framework of the EULEP/EURADOS Action Group, 'Derivation of parameter values for application to the new model of the human respiratory tract for occupational exposure'. The most important lesson learned from these intercomparison exercises was the need to develop agreed guidelines for internal dose evaluation procedures to promote harmonisation of assessments between organisations and countries.

Benchmarking↗

PubMed2003

Guidance on internal dose assessments from monitoring data (project IDEAS).

Several international inter-comparison exercises on intake and internal dose assessments from monitoring data led to the conclusion that the results calculated by different participants varied significantly, mainly due to the broad variety of methods and assumptions applied in the assessment procedure. Based on these experiences, the need of harmonisation of the procedures has been formulated as an EU research project under the 5th Framework Programme, with the aim of developing general guidelines for standardising assessments of intakes and internal doses. In the IDEAS project, eight institutions from seven European countries are participating, also using inputs from internal dosimetry professionals from across Europe to ensure broad consensus in the outcome of the project. To ensure that the guidelines are applicable to a wide range of practical situations, the first step will be to compile a database on well documented cases of internal contamination. In parallel, an improved version of existing software will be developed and distributed to the partners for further use. Many cases from the database will be evaluated independently by more partners using the same software and the results will be discussed and the draft guidelines prepared. The guidelines will then be revised and refined on the basis of the experiences and discussions of two workshops, and an intercomparison exercise organised in the frame of the project which will be open to all internal dosimetry professionals.

Body Burden↗

PubMed2003

Factors affecting knee cartilage volume in healthy men.

OBJECTIVES: To understand the factors that influence joint cartilage in health and disease as they are important for the prevention and management of osteoarthritis. METHODS: We conducted a cross-sectional study to determine factors influencing knee cartilage volume in 45 males aged (mean+/-S.D.) 52.5+/-13.2 yr. RESULTS: Total and medial tibial volumes were inversely associated with age, body mass index (BMI) and amount of physical activity and positively associated with total bone content. BMI explained the largest amount of the variation in tibial cartilage volume (18.7%). There were similar findings at the lateral tibial cartilage, but for age and total bone content this did not reach statistical significance. There was a positive association with serum testosterone at all tibial cartilage sites, but this only reached statistical significance for medial tibial cartilage, where serum testosterone explained up to 8% of the variation in cartilage volume. CONCLUSIONS: Modifiable risk factors of osteoarthritis also appear to be significant determinants of tibial cartilage volume. Serum testosterone may provide one possible explanation for gender differences in tibial cartilage volume and prevalence of tibiofemoral osteoarthritis. The proposed link between osteoarthritis and knee cartilage volume and the effect of testosterone will need to be confirmed in longitudinal studies.

Adult↗

PubMed2003

Differential major histocompatibility complex class II locus expression on human laryngeal epithelium.

The survival of a laryngeal allograft will be dependent on the immunological composition of the donor larynx and, in particular, on the expression of major histocompatibility complex (MHC) class II antigens on professional and non-professional antigen-presenting cells. Laryngeal and tonsillar biopsies from normal individuals aged 18-78 years were processed and prepared for quantitative, multiple-colour immunofluorescence using mouse antihuman monoclonal antibodies to human leucocyte antigen (HLA)-DR, HLA-DQ and CD45. The laryngeal epithelium expressed HLA-DR locus products at variable levels, but expression of HLA-DQ was virtually absent. Tonsillar epithelial cells expressed HLA-DR at the basal layer only, while HLA-DQ was similarly not expressed. In contrast, both HLA-DR and -DQ locus products were present on lamina propria and intraepithelial leucocytes in both laryngeal and tonsillar mucosae, although at varying levels. The finding that laryngeal epithelial cells express MHC class II antigens has implications for the survival of laryngeal allografts and suggests that they may require significant immunomodulation. In addition, antigen presentation by epithelial cells has been hypothesized to contribute to the immunoregulatory function of mucosal tissues, and the finding that HLA-DQ locus products are only expressed at low levels by laryngeal epithelium raises questions about the repertoire of peptides to which the mucosal immune system can respond.

Adolescent↗

PubMed2002

Comparison of genome screens for two independent cohorts provides replication of suggestive linkage of bone mineral density to 3p21 and 1p36.

Low bone mineral density (BMD) is a major risk factor for osteoporotic fracture. Studies of BMD in families and twins have shown that this trait is under strong genetic control. To identify regions of the genome that contain quantitative trait loci (QTL) for BMD, we performed independent genomewide screens, using two complementary study designs. We analyzed unselected nonidentical twin pairs (1,094 pedigrees) and highly selected, extremely discordant or concordant (EDAC) sib pairs (254 pedigrees). Nonparametric multipoint linkage (NPL) analyses were undertaken for lumbar spine and total-hip BMD in both cohorts and for whole-body BMD in the unselected twin pairs. The maximum evidence of linkage in the unselected twins (spine BMD, LOD 2.7) and the EDAC pedigrees (spine BMD, LOD 2.1) was observed at chromosome 3p21 (76 cM and 69 cM, respectively). These combined data indicate the presence, in this region, of a gene that regulates BMD. Furthermore, evidence of linkage in the twin cohort (whole-body BMD; LOD 2.4) at chromosome 1p36 (17 cM) supports previous findings of suggestive linkage to BMD in the region. Weaker evidence of linkage (LOD 1.0-2.3) in either cohort, but not both, indicates the locality of additional QTLs. These studies validate the use, in linkage analysis, of large cohorts of unselected twins phenotyped for multiple traits, and they highlight the importance of conducting genome scans in replicate populations as a prelude to positional cloning and gene discovery.

Adolescent↗

PubMed2002

Laparascopic sigmoid colectomy for diverticular disease in a patient with situs inversus.

We present the case of a 50-year-old man with situs inversus who underwent laprascopic colonic resection for diverticulitis. The patient, who had right-sided pain due to inversion of the viscera mimicking appendicitis, initially presented a diagnostic challenge. A barium meal confirmed situs inversus and the diagnosis of diverticulitis. We present an overview of the operative technique of what is the first documented laparoscopic colectemy in a patient with situs inversus. We then discuss the benefits of the laproscopic approach to colectomy, with reference to this interesting case with unusual anatomy.

Colectomy↗

PubMed2002

Quercetin derivatives are deconjugated and converted to hydroxyphenylacetic acids but not methylated by human fecal flora in vitro.

By using a batch in vitro anaerobic fecal fermentation model, we have shown that the fecal microflora can rapidly deconjugate rutin, isoquercitrin, and a mixture of quercetin glucuronides. High levels of beta,D-glucosidase, alpha,L-rhamnosidase, and beta,D-glucuronidase were present. Rutin underwent deglycosylation, ring fission, and dehydroxylation. The main metabolite, 3,4-dihydroxyphenylacetic acid, appeared rapidly (2 h) and was dehydroxylated to 3-hydroxyphenylacetic acid within 8 h. The pattern of in vitro fermentation of rutin was not changed by changing the pH (6.0 or 6.9), fermentation scale (10 or 1000 mL), or donors of the inoculum. Hydroxyphenylacetic acids were not methylated by colon flora in vitro. The colonic microflora has enormous potential to transform flavonoids into lower molecular weight phenolics, and these might have protective biological activities in the colon. The site of absorption of flavonoids and the form in which they are absorbed are critical for determining their metabolic pathway and consequent biological activities in vivo.

3,4-Dihydroxyphenylacetic Acid↗

PubMed2002

Postal survey of ovine caseous lymphadenitis in the United Kingdom between 1990 and 1999.

Members of the Sheep Veterinary Society and three terminal sire breed societies (A, B and C) were surveyed to investigate the prevalence and characteristics of ovine caseous lymphadenitis in the UK. In total, 264 veterinary surgeons and 510 farmers responded. Eighteen per cent of the vets had seen at least one case of the disease, and 45 per cent of the farmers had seen abscesses in their sheep. Relatively few farmers had had the cause of the abscesses investigated, but 24 of the 32 flocks that had submitted samples to a laboratory had had the disease confirmed. The incidence of the disease and abscesses increased from 1990 to 1999. The disease was more likely to be investigated in certain breeds and when male sheep had abscesses. Risk factors for the disease included the presence of sheep of breed B in the flock, the presence of half-bred sheep, showing sheep, and the use of shearing contractors. Dipping sheep appeared to be protective.

Animals↗