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R Andrews

Publications and source records attributed to R Andrews.

At least 19 recordsLinked to original sources
PubMed2006

Observation of muon neutrino disappearance with the MINOS detectors in the NuMI neutrino beam.

This Letter reports results from the MINOS experiment based on its initial exposure to neutrinos from the Fermilab NuMI beam. The rates and energy spectra of charged current nu(mu) interactions are compared in two detectors located along the beam axis at distances of 1 and 735 km. With 1.27 x 10(20) 120 GeV protons incident on the NuMI target, 215 events with energies below 30 GeV are observed at the Far Detector, compared to an expectation of 336+/-14 events. The data are consistent with nu(mu) disappearance via oscillations with |Delta(m)2/32|=2.74 +0.44/-0.26 x10(-3)eV(2) and sin(2)(2theta(23))>0.87 (68% C.L.).

Journal Article↗
PubMed2006

Clear not simple: an approach to community consultation for a maternal pneumococcal vaccine trial among Indigenous women in the Northern Territory of Australia.

PneuMum is a randomised controlled maternal vaccination trial, using 23-valent Pneumococcal Polysaccharide Vaccine (23vPPV) during the third trimester or at delivery compared to vaccination at 7 months post delivery. The primary outcomes are infant middle ear disease and nasopharyngeal pneumococcal carriage at 7 months of age. PneuMum is the first vaccine trial to be conducted among Indigenous people in the Northern Territory. We describe the study design and the approach taken to develop the PneuMum message in collaboration with key Indigenous stakeholders and then to communicate the PneuMum message with Indigenous communities and potential participants. We hope that these methods will provide a model for future research involving Indigenous communities to ensure Indigenous involvement in research and ultimate improvements in Indigenous health.

Adolescent↗
PubMed2006

The role of mitochondrial haplogroups in primary open angle glaucoma.

AIM: To investigate a possible association between mitochondrial haplogroups and primary open angle glaucoma (POAG). METHODS: Genomic DNA was extracted from 140 POAG patients and 75 healthy individuals. Restriction enzyme digest analysis of polymerase chain reaction (PCR) amplified fragments was used to determine the mitochondrial haplogroup of each patient and control. RESULTS: The median age was 73 years for the POAG patients (range 51-87, SD 8.01) and 78 years for the controls (range 68-90, SD 4.4). Mean IOP was 20.8 mm Hg for the patients (SD 2.6) and 16.2 mm Hg for the controls (SD 3.4). Median cup/disc ratio was 0.8 and 0.3 for patients and controls respectively. No statistically significant difference was found in the haplogroup distribution between the POAG patients and the healthy individuals (Fisher's exact test). CONCLUSION: In this cohort, mitochondrial haplogroups do not appear to contribute to the pathogenesis of POAG.

Aged↗
PubMed2005

Right ventricular infarction complicated by right to left shunting through an atrial septal defect: successful treatment with an Amplatzer septal occluder.

A 68 year old woman presented with right ventricular myocardial infarction complicated by refractory hypoxaemia. She was found to have a significant right to left shunt at the atrial level through a previously undiagnosed ostium secundum atrial septal defect. Percutaneous closure of the atrial septal defect with an Amplatzer septal occluder resulted in prompt improvement in her oxygenation and clinical state. Such closure should be considered for patients with right ventricular infarction and refractory hypoxaemia caused by a right to left interatrial shunt.

Aged↗
PubMed2004

Head lice prevalence in primary schools in Victoria, Australia.

OBJECTIVES: To determine the prevalence of and assess risk factors associated with head lice infections (pediculosis) in children from government primary schools in Victoria, Australia. METHODS: Between May and October 2001, children were selected by clustered random sampling of schools and classes, then examined for head lice using hair conditioner and a fine-toothed head lice comb. There were 1838 children screened from 16 primary schools. Risk factors evaluated included metropolitan or rural residence, school class, gender and hair length. RESULTS: Thirteen percent of children (239/1838) had an active infection (95% CI, 10.9-15.1) and 3.3% (61/1838) had an inactive infection (95% CI, 2.0-4.6). Prevalence of active pediculosis varied between schools from 0 to 28%. Our screening identified no more than one case per class in the majority of classes screened (58.5%). Females were 2.2 times more likely to have active infection than males (95% CI [1.7,2.9]) and there was no significant difference for the other risk factors investigated. CONCLUSIONS: Our study demonstrated the prevalence of head lice varied across Victoria and showed that risk factors commonly attributed to head lice infections did not hold true. Our findings support the premise that traditional ad hoc mass school-based screening may not be the best use of resources when controlling head lice. We suggest a more pragmatic community-based approach.

Adolescent↗
PubMed2004

Heliox in the treatment of chronic obstructive pulmonary disease.

OBJECTIVE: To determine if breathing helium oxygen mixtures in addition to conventional therapy in non-intubated adult chronic obstructive airways disease (COPD) patients reduces the arterial partial pressure of carbon dioxide (Paco(2)) more than conventional treatment alone, and confers an advantage in terms of the odds of intubation in the acute setting. DESIGN: Meta-analysis. SETTING: Diverse settings. PARTICIPANTS: Adult patients with a diagnosis of either stable severe or acute COPD. MAIN OUTCOME MEASURES: Decrease in partial pressure of arterial Paco(2) and intubation rates. RESULTS: Combination of the results from trials measuring change in Paco(2) in COPD subjects receiving conventional therapy but breathing helium-oxygen estimated a reduction of 0.78 KPa (1.44-0.13) beyond that produced by conventional therapy with air-oxygen breathing (n = 234). Using quantitative and qualitative measures of validity it was found that most trials were unsatisfactory. Chief concerns were poor concealment of allocation and lack of blinding. Analysis excluding all papers with low methodological quality (Jadad<2) estimated the reduction in Paco(2) conferred by use of Heliox breathing to be 0.22 KPa (+0.57 to -0.14). A non-significant reduction (p = 0.2). When combined, the results from trials measuring the intubation rates of patients treated conventionally or with Heliox (n = 121) the odds ratio of intubation was 0.096 (0.03-0.27). CONCLUSION: Definitive evidence of a beneficial role of Heliox in treatment of severe COPD is lacking and therefore its wide scale use cannot be recommended based on this analysis. However, as a beneficial effect of Heliox breathing was reported in all trials, further investigation with a well conducted randomised controlled trial is warranted.

Adult↗
PubMed2004

Predicting sudden death in patients with mild to moderate chronic heart failure.

OBJECTIVES: To explore the relation between non-invasive measures of cardiac function and sudden cardiac death, as well as the development and utility of an index integrating these variables to identify patients at increased risk of this mode of death. DESIGN: UK-HEART (United Kingdom-heart failure evaluation and assessment of risk trial) was a prospective study conducted between December 1993 and April 2000. The study was specifically designed to identify non-invasive markers of death and mode of death among patients with chronic heart failure. SETTING: 8 UK general hospitals. MAIN OUTCOME MEASURES: Death and mode of death. RESULTS: 553 patients aged a mean (SD) of 63 (10) years, in New York Heart Association functional class 2.3 (0.02), recruited prospectively. After 2365 patient-years' follow up, 201 patients had died (67 suddenly). Predictors of sudden death were greater cardiothoracic ratio, QRS dispersion, QT dispersion corrected for rate (QTc) across leads V1-V6 on the 12 lead ECG, and the presence of non-sustained ventricular tachycardia. The hazard ratio and 95% confidence intervals (CI) of sudden death for a 10% increase in cardiothoracic ratio was 1.43 (95% CI 1.20 to 1.71), for a 10% increase in QRS dispersion 1.11 (95% CI 1.04 to 1.19), for the presence of non-sustained ventricular tachycardia 2.03 (95% CI 1.27 to 3.25), and for a 10% increase in QTc dispersion across leads V1-V6 1.03 (95% CI 1.00 to 1.07) (all p < 0.04). An index derived from these four factors performed well in identifying patients specifically at increased risk of sudden death. CONCLUSIONS: Results show that an index derived from three widely available non-invasive investigations has the potential to identify ambulant patients with chronic heart failure at increased risk of sudden death. This predictive tool could be used to target more sophisticated investigations or interventions aimed at preventing sudden death.

Aged↗
PubMed2003

Vaccines for preventing pneumococcal infection in adults.

BACKGROUND: Diseases caused by Streptococcus pneumoniae (S. pneumoniae) continue to cause substantial morbidity and mortality throughout the world. Polysaccharide pneumococcal vaccines have been developed for over 50 years and may have the potential to prevent disease and death. OBJECTIVES: To assess the effectiveness of polysaccharide pneumococcal vaccination in preventing disease or death in adults. SEARCH STRATEGY: Trials were identified by electronic searches of the Cochrane Central Register of Controlled Trials (CENTRAL) issue 2, 2003 (which includes the Cochrane ARI Group's specialised register); MEDLINE (January 1966 to June 2003); and EMBASE (1974 to June 2003). We searched existing literature. The bibliographies of all newly revealed studies were read in order to identify further studies. The vaccine manufacturers, the lead authors of newly identified studies not included in existing meta-analyses were contacted. SELECTION CRITERIA: A) Prospective, randomised or quasi-randomised studies comparing pneumococcal vaccines with placebo, control vaccines or no intervention.B) Case-control studies (including indirect cohort studies) assessing pneumococcal vaccine effectiveness against invasive pneumococcal disease. Cohort studies are excluded. DATA COLLECTION AND ANALYSIS: A) Randomised studies. Trial quality assessment was conducted by two reviewers (JH and DT). Data extraction was done by three reviewers (JH, DT, KD). There were many instances of unclear or incomplete data in the trial reports, and the final dataset was arrived at after much deliberation and discussion, including comparison with the data used in two previous reviews of this question. Due to the age of the trials (dating back to 1954 in one case) it was not generally possible to obtain clarification from the authors, though a partial clarification was achieved in one case.B) Non-randomised studies. Study quality was assessed by two reviewers (RA and KD). MAIN RESULTS: The combined results from the randomised studies fail to show that the polysaccharide pneumococcal vaccine is effective in preventing either pneumonia (outcome 6: odds ratio = 0.77, confidence interval 0.58, 1.02, number = 14) or death (outcome 8: odds ratio 0.90, confidence interval 0.76, 1.07, number = 11). Despite encouraging data from some very early trials, pooling trials published from 1977 on suggests there is no effect (outcome 6; odds ratio = 0.96, confidence interval 0.80, 1.15, number = 12; outcome 9: odds ratio = 0.98, confidence interval 0.88, 1.09, number = 10). The available data cannot distinguish whether this heterogeneity in results is due to improvements in trial methodology and reporting, to differences in trial setting or to real loss of efficacy over time. This is because the early, poorly reported trials were conducted in high-risk healthy populations where the expected benefit is greatest. The case-control studies show significant efficacy in preventing invasive pneumococcal disease: OR 0.47 (CI 0.37, 0.59) corresponding to an efficacy of 53%. REVIEWER'S CONCLUSIONS: While polysaccharide pneumococcal vaccines do not appear to reduce the incidence of pneumonia or death in adults with or without chronic illness, or in the elderly (55 years and above), the evidence from non-randomised studies suggests that the vaccines are effective in the reducing the incidence of the more specific outcome, invasive pneumococcal disease, among adults and the immunocompetent elderly (55 years and above). Surveillance data suggest that infection rates vary widely between and also within countries, but a typical figure in developed countries is 0.01%, or 10 per 100,000 per year. Efficacy of 50% then corresponds to a number-needed-to-treat (NNT) of 20,000 vaccinations per infection avoided, and perhaps 50,000 per death avoided.

Adult↗
PubMed2003

Enhanced mechanical properties of polyacrylonitrile/multiwall carbon nanotube composite fibers.

The use of multiwall carbon nanotubes (MWNTs) as a reinforcing phase in a polyacrylonitrile (PAN) fiber matrix was investigated with the goal of producing a PAN-derived carbon/MWNT composite fiber with enhanced physical properties. MWNTs were dispersed in a PAN/DMAc (dimethylacetamide) solution and spun into composite fibers containing up to 5 wt.% MWNTs, with the use of a lab-scale dry-jet wet spinline. The spinning process resulted in alignment of the MWNTs parallel with the fiber axis. Three types of chemical vapor deposition (CVD)-derived, high-purity MWNTs were used: as produced, graphitized (heat treated to 2800 degrees C), and NaCN-treated (chemically treated to attach CN groups to the nanotube surface). Tensile tests were performed to measure yield stress/strain, initial modulus, break stress/strain, and energy to yield and energy to break. Significant mechanical property increases were recorded for the composite fibers compared with the control samples with no MWNT reinforcement: break strength +31%, initial modulus +36%, yield strength +46%, energy to yield +80%, and energy to break +83%.

Acrylic Resins↗
PubMed2002

The use of sequential studies in a salmonellosis outbreak linked to continental custard cakes.

We investigated an outbreak of 54 cases of Salmonella Typhimurium phage type 9 (STM9) with a specific antibiotic resistance pattern. We used sequential analytic studies: two retrospective cohort studies, a case-control study, and a modified case-control study. An outbreak of salmonellosis due to Salmonella Typhimurium PT9 SSu (resistant to streptomycin and sulphafurazole) was identified. Fifty-four cases had illness onset from November 1998 to March 1999. Notifications commenced following a restaurant birthday party in December 1998. An initial cohort and case control study found no association with consumption of custard cake. However, case follow-up identified another cohort of people who had attended a birthday party in February at which 8/27 people who consumed a continental custard cake were ill compared to 0/10 who did not (P = 0.07). A revised case control study found illness was strongly associated with consumption of a particular continental custard cake (Mantel-Haenszel matched OR infinity, P = 0.00004). This report highlights the epidemiological value of using sequential study types, and persisting with the investigation of apparently sporadic food-borne outbreaks.

Anti-Bacterial Agents↗
PubMed2002

Systemic cholesterol crystal embolisation with pulmonary involvement: a fatal combination after coronary angiography.

Cholesterol crystal embolisation (CCE) is a rare but serious complication of invasive arterial procedures associated with a high mortality, and is a condition that medical staff undertaking invasive vascular procedures should be aware of. It is manifest as a multisystem disorder commonly involving the kidneys and peripheries, but rarely affecting the lungs. A case of fatal CCE with pulmonary involvement is reported, and similar published case reports are reviewed. The pathogenesis of lung involvement in CCE is unclear, but the combination is reported to be invariably fatal.

Coronary Angiography↗
PubMed2001

Reconstitution of a functional human type II IL-4/IL-13 receptor in mouse B cells: demonstration of species specificity.

IL-13 is a Th2-derived pleiotropic cytokine that recently was shown to be a key mediator of allergic asthma. IL-13 mediates its effects via a complex receptor system, which includes the IL-4R alpha-chain, IL-4Ralpha, and at least two other cell surface proteins, IL-13Ralpha1 and IL-13Ralpha2, which specifically bind IL-13. IL-13 has been reported to have very limited effects on mouse B cells. It was unclear whether this was due to a lack of receptor expression, a disproportionate relative expression of the receptor components, or an additional subunit requirement in B cells. To determine the requirements for IL-13 signaling in murine B cells, we examined IL-13-dependent Stat6 activation and CD23 induction in the murine B cell line, A201.1. A201.1 cells responded to murine IL-4 via the type I IL-4R, but were unresponsive to IL-13, and did not express IL-13 receptor. B220(+) splenocytes also failed to signal in response to IL-13 and did not express IL-13 receptor. We transfected A201.1 cells with human IL-4Ralpha, IL-13Ralpha1, or both. Transfectants expressing either human IL-4Ralpha or human IL-13Ralpha1 alone were unable to respond or signal to IL-13. Thus, human IL-13Ralpha1 could not combine with the endogenous murine IL-4Ralpha to generate a functional IL-13R. However, cells transfected with both human IL-4Ralpha and IL-13Ralpha1 responded to IL-13. Thus, the relative lack of IL-13 responsiveness in murine B cells is due to a lack of receptor expression. Furthermore, the heterodimeric interaction between IL-4Ralpha and IL-13Ralpha1 is species specific.

Animals↗
PubMed2001

Single incision for implanting a vagal nerve stimulator system (VNSS): technical note.

BACKGROUND: A technique for implanting the vagal nerve stimulator system through a single incision is described. METHOD: A transverse incision is made in the lower part of the neck. Subcutaneous (s.c.) dissection is then done over the clavicle into the infraclavicular area to create a pocket. The vagus nerve is exposed and the electrodes are wrapped around it through the neck incision. The distal ends of the lead are connected to the pulse generator, and latter is then placed in the infraclavicular pocket through the neck incision. RESULTS: Thirty-eight implants were conducted with this technique. The pulse generator could be implanted and anchored to the underlying tissue without any difficulty. Except for wound infections in two patients there was no other complication. CONCLUSION: A single incision is an alternate to the double incision procedure. This procedure can be performed safely.

Adolescent↗
PubMed2001

Outcome of staged reconstructive surgery for hypoplastic left heart syndrome following antenatal diagnosis.

BACKGROUND AND AIMS: Staged reconstructive surgery has radically altered the prognosis of hypoplastic left heart syndrome (HLHS). Antenatal diagnosis allows for appropriate counselling, and time to consider treatment options. We report outcome from a centre where most cases are antenatally diagnosed and delivered on site. METHODS: Information was collated on 188 consecutive cases of HLHS between 1995 and 2000, including timing of diagnosis, outcome of pregnancy, and age and outcome at each stage of surgery. At Guy's Hospital, 174 cases were diagnosed antenatally, of whom 50 underwent surgery. Fourteen others (five diagnosed antenatally at other centres, and nine diagnosed postnatally) also underwent surgery. RESULTS: Survival after stage I (the Norwood operation) was 52% (33/64). Postoperative survival after stage II (the hemi-Fontan operation, performed in 29), and stage III (the Fontan operation, performed in 10), was 100%. Two late deaths occurred 3 and 10 months after stage II, giving overall survival of 48% (31/64). At follow up, three children have neurological impairment, and one had poor right ventricular function necessitating cardiac transplantation. CONCLUSIONS: Antenatal diagnosis allows informed decisions about treatment options, and facilitates preoperative care. Mortality following stage I is high, irrespective of timing of diagnosis, but medium term outcome for survivors is good.

Cardiac Surgical Procedures↗