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Biomedical subjects

P O'Reilly

Publications and source records attributed to P O'Reilly.

At least 19 recordsLinked to original sources
PubMed2006

Comparison of the efficacies of disinfectants to control microbial contamination in dental unit water systems in general dental practices across the European Union.

Water delivered by dental unit water systems (DUWS) in general dental practices can harbor high numbers of bacteria, including opportunistic pathogens. Biofilms on tubing within DUWS provide a reservoir for microorganisms and should be controlled. This study compared disinfection products for their ability to meet the American Dental Association's guideline of <200 CFU x ml(-1) for DUWS water. Alpron, BioBlue, Dentosept, Oxygenal, Sanosil, Sterilex Ultra, and Ster4Spray were tested in DUWS (n = 134) in Denmark, Germany, Greece, Ireland, The Netherlands, Spain, and the United Kingdom. Weekly water samples were tested for total viable counts (TVCs) on yeast extract agar, and, where possible, the effects of products on established biofilm (TVCs) were measured. A 4- to 5-week baseline measurement period was followed by 6 to 8 weeks of disinfection (intermittent or continuous product application). DUWS water TVCs before disinfection ranged from 0 to 5.41 log CFU x ml(-1). Disinfectants achieved reductions in the median water TVC ranging from 0.69 (Ster4Spray) to 3.11 (Dentosept) log CFU x ml(-1), although occasional high values (up to 4.88 log CFU x ml(-1)) occurred with all products. Before treatment, 64% of all baseline samples exceeded American Dental Association guidelines, compared to only 17% following commencement of treatment; where tested, biofilm TVCs were reduced to below detectable levels. The antimicrobial efficacies of products varied (e.g., 91% of water samples from DUWS treated with Dentosept or Oxygenal met American Dental Association guidelines, compared to 60% of those treated with Ster4Spray). Overall, the continuously applied products performed better than those applied intermittently. The most effective products were Dentosept and Oxygenal, although Dentosept gave the most consistent and sustained antimicrobial effect over time.

Biofilms↗
PubMed2005

Microbial contamination of dental unit water systems.

INTRODUCTION: Dental unit water systems (DUWS) may serve as a reservoir for biofilms that contribute to high numbers of bacteria in the water used during dental treatment. These microbes are predominantly harmless but potentially pathogenic organisms can also be present in the biofilm. This may pose a potential health risk for patients and dental personnel. AIM: to determine the microbial levels of DUWS in dental practices. MATERIALS AND METHOD: A cross-sectional study of water and tubing samples from 30 general dental practices (15 health board and 15 private surgeries) was undertaken as part of a pan-European investigation of the microbial qualitative and quantitative aspects of DUWS. RESULTS: Microbial loads ranged from 100 to 104 cfu ml-1 and exceeded the European guidelines for drinking water in many cases. The available evidence suggested the presence of isolates most likely belonging to families of aquatic and soil bacteria. It was not possible to draw distinct conclusions correlating microbial loads with dental unit parameters, including age of the unit, water source and chemistry and presence or absence of anti-retraction devices. Opportunistic or true pathogens were not detected. Yeasts were observed in samples from three units although further analysis confirmed that these were not Candida albicans. A decontamination strategy applied to one of the units eliminated the yeasts completely. CONCLUSIONS: Dental practitioners must be knowledgeable regarding microbial contamination and biofilm formation in dental unit waterlines. There is a need for development of European evidence-based guidelines and reliable control regimes for microbial contamination of DUWS.

Biofilms↗
PubMed2003

The fatigue strength of compact bone in torsion.

We have conducted a series of fatigue tests on samples of bovine compact bone loaded in cyclic torsion. The fatigue strength (i.e. the range of stress needed to cause failure in a given number of cycles) was found to be lower than the fatigue strength of the same material in compression by more than a factor of two. We also tested intact chicken metatarsals and found a similar reduction in strength compared to compression testing of chicken tibiae. These results were predicted using a theoretical model in which fatigue failure was assumed to be dependent on the growth of microcracks, oriented approximately parallel to the bone's longitudinal axis but having misorientation angles of up to 30 degrees. An effective stress range was derived which is a function of the normal and shear stresses, and thus of the Mode I and Mode II stress intensities experienced by the crack. These results may have important consequences for the understanding of fatigue in bone in vivo; relatively small amounts of longitudinal shear stress, which are often ignored in analysis, may contribute significantly to fatigue failures. This may shed light on the phenomenon of stress fractures and on the need for repair and adaptation in living bone.

Animals↗
PubMed2003

Pharmaceutical review.

Explore the source record for details and available documents.

Adrenergic alpha-Antagonists↗
PubMed2000

An assessment of the aggressive potential of radiolucencies related to the mandibular molar teeth.

AIM: The purpose of this study was to outline the radiographic appearance of radiolucent lesions related to the molar teeth and to determine which features indicate aggressive lesions. PATIENTS AND METHODS: Panoramic radiographs were reviewed in 66 patients with radiolucencies related to the molar teeth. The radiographic appearances of the lesions were assessed with regard to location and size, and the relationship to the molar teeth. Radiographic evidence of aggression was assessed and pathology reviewed. RESULTS: Nineteen patients had aggressive and 47 had non-aggressive radiolucent lesions. The aggressive lesions included keratocysts, unicystic ameloblastoma, adenoid cystic carcinoma, giant cell granuloma, myxofibroma, chondroblastic osteosarcoma, mestastases and squamous cell carcinoma of the tongue invading the mandible. CONCLUSION: The differential diagnosis of radiolucent lesions in the mandible can be difficult using panoramic radiographs alone. Helpful features in determining aggression were older patients, larger lesions, Lodwick type IC tumour border, condition of the mandibular cortex, movement of adjacent teeth and the relationship of the inferior alveolar canal.

Adult↗
PubMed2000

Cardiac rhythm disturbances in the obstructive sleep apnea syndrome: effects of nasal continuous positive airway pressure therapy.

STUDY OBJECTIVES: A high incidence of nocturnal cardiac rhythm disturbances among patients with obstructive sleep apnea (OSA) syndrome has been described in some reports, but not in others. We wished to examine the prevalence of significant cardiac rhythm disturbance in patients with established moderate to severe OSA syndrome and, in particular, to assess the impact of nasal continuous positive airway pressure (nCPAP) therapy. DESIGN AND SETTING: A prospective study of consecutive eligible patients in a dedicated sleep disorders unit of a university teaching hospital. MEASUREMENTS AND RESULTS: Holter monitoring was performed for 18 h in 45 patients with previously diagnosed OSA syndrome (mean [SD] apnea/hypopnea frequency [AHI] of 50 [23]/h) and repeated within 2 to 3 days after institution of nCPAP therapy. Investigators were blinded to the patients' treatments during data analysis. Thirty-five patients were found to have some cardiac rhythm disturbance, but only 8 had pathologically significant disturbances (ventricular tachycardia or fibrillation, complex ventricular ectopy, new-onset supraventricular tachycardia other than sinus tachycardia, pauses of > 2 s, and second- or third-degree heart block). Significant rhythm disturbances occurred only during the nighttime, and there was a significant correlation between OSA severity and the severity of rhythm disturbance (p = 0.04, r = 0.301). No significant correlation was found between OSA severity and any other anthropometric parameter measured. nCPAP therapy resulted in abolition of rhythm disturbance in seven of these eight patients; the eighth patient was found to have coexisting severe aortic valve disease requiring valve replacement. CONCLUSION: The data indicate that OSA syndrome predisposes to clinically significant cardiac rhythm disturbances that can be successfully controlled by nCPAP therapy.

Body Mass Index↗
PubMed1999

Identification of a CD4 domain required for interleukin-16 binding and lymphocyte activation.

Interleukin-16 (IL-16) activates CD4(+) cells, possibly by direct interaction with CD4. IL-16 structure and function are highly conserved across species, suggesting similar conservation of a putative IL-16 binding site on CD4. Comparison of the human CD4 amino acid sequence with that of several different species revealed that immunoglobulin-like domain 4 is the most conserved extracellular region. Potential interaction of this domain with IL-16 was studied by testing murine D4 sequence-based oligopeptides for inhibition of IL-16 chemoattractant activity and inhibition of IL-16 binding to CD4 in vitro. Three contiguous 12-residue D4 region peptides (designated A, B, and C) blocked IL-16 chemoattractant activity, with peptide B the most potent. Peptides A and B were synergistic for inhibition, but peptide C was not. Peptides A and B also blocked IL-16 binding to CD4 in vitro, whereas peptide C did not. CD4, in addition to its known function as a receptor for major histocompatibility complex class II, contains a binding site for IL-16 in the D4 domain. The D4 residues required for IL-16 binding overlap those previously shown to participate in CD4-CD4 dimerization following class II major histocompatibility complex binding, providing a mechanistic explanation for the known function of IL-16 to inhibit the mixed lymphocyte reaction.

Amino Acid Sequence↗
PubMed1999

Consensus on renal cortical scintigraphy in children with urinary tract infection. Scientific Committee of Radionuclides in Nephrourology.

A questionnaire related to cortical scintigraphy in children with urinary tract infection was submitted to 30 experts. A wide consensus was reached on several issues related to planar images: 99mTc dimercapto succinic acid (DMSA) appears as the most appropriate tracer for renal imaging; dynamic tracers are considered to be inferior, in particular 99mTc diethylenetriaminepentaacetate, which is not recommended. The general opinion is that DMSA scintigraphy is not feasible with a minimal dose below 15 MBq, whereas the maximum dose should not be higher than 110 MBq. The dose schedule generally is based on body surface area, and sedation is only exceptionally given to children. Images are obtained 2 to 3 hours after injection, preferably with high resolution collimators; pinhole images are used by only half of the experts. Posterior and posterior oblique views are used by most of the experts, and the posterior view is acquired in supine positions. At least 200.000 kcounts or 5 minute acquisition is required for nonzoomed images. As a quality control, experts check the presence of blurred or double outlines on the DMSA images. Color images are not used and experts report on film or directly on the computer screen. As far as normal DMSA images are concerned, most experts agree on several normal variants. Hydronephrosis is not a contraindication for DMSA scintigraphy but constitutes a pitfall. Differential renal function generally is measured, but no consensus is reached whether or not background should be subtracted. Most of the experts consider 45% as the lowest normal value. A consensus is reached on some scintigraphic aspects that are likely to improve and on some others that probably represent persistent sequelae. There is a wide consensus for the systematic use of DMSA scintigraphy for detection of renal sequelae, whereas only 58% of the experts are systematically performing this examination during the acute phase of infection.

Child↗
PubMed1999

Compression data on bovine bone confirms that a "stressed volume" principle explains the variability of fatigue strength results.

The literature contains many measurements of the fatigue properties of compact bone, but these experimental results have been difficult to interpret and use due to a large amount of apparent scatter: variation in the number of cycles to failure for a given cyclic stress or strain range. Recently Taylor (1998a, Journal of Orthopaedic Research, 16, 163-169) showed that much of this scatter could be explained using a statistical model which took into account specimen size, or more specifically stressed volume. The present paper describes an attempt to test this model by using it to predict some new data, for bovine bone tested in compressive loading at room temperature at physiological loading rates. Twenty specimens were tested at the same applied load range (100 MPa). The theory was able to predict the mean behaviour of the specimens very well, with an accuracy (expressed in terms of stress) of 2%. It was also able to predict the degree of scatter (i.e. the variation of Nf), which was shown to be similar to that measured by other workers.

Animals↗
PubMed1999

The spectrum of mycobacterial disease in a Dublin teaching hospital.

We describe our experience at our combined tuberculosis and public health clinic, which has been in existence since 1991, and compare it to a previous review of tuberculosis at St. Vincent's Hospital from 1974 to 1979. A total of 107 patients were treated, 58 male and 49 female, with a mean age of 53 years. Seventy-seven patients had pulmonary tuberculosis, 23 extrapulmonary and three had both. Four patients had miliary tuberculosis. Our figures reflect the fall in incidence of tuberculosis in Ireland since the 1970's and a rise in smear negative and presumptive cases. The epidemiology of tuberculosis in Ireland is little changed except for an increasing impact of immigration. Problems such as late diagnosis, especially in older patients, and non-compliance remain significant. In addition, there were four deaths from tuberculosis. However, our combined clinic has led to the appropriate management of patients by Respiratory Medicine specialists and a great move to ambulatory diagnosis and management. We believe it is the best model for the effective management of tuberculosis in Ireland.

Adult↗
PubMed1996

Consensus on diuresis renography for investigating the dilated upper urinary tract. Radionuclides in Nephrourology Group. Consensus Committee on Diuresis Renography.

UNLABELLED: There is great variation in technique and interpretation of diuresis renography between different establishments. METHODS: To address this problem, an International Consensus Committee was appointed by the Ninth International Symposium on Radionuclides in Nephrourology in 1994. RESULTS: The final document was produced and addressed: objectives, equipment, data acquisition, choice of radiopharmaceutical, patient preparation, position, dosage of furosemide, timing of furosemide, role of bladder catheter, duration of study, pediatric considerations, evaluation of the furosemide response, interpretation, and conclusion. CONCLUSION: The report presents a standardized approach to diuresis renography that, if adopted, will improve reproducibility between centers, discourage unacceptable practice and stimulate further discussion between nuclear medicine and urology health care professionals who treat patients with dilated and obstructed upper urinary tracts.

Adolescent↗
PubMed1994

Alcohol content of proprietary mouthwashes.

The use of mouthwashes with high ethanol content has been linked to excess risks of mouth cancer, as have prolonged and frequent use of mouthwashes with lower ethanol contents. Twenty two proprietary mouthwashes available without prescription in Ireland were analysed by gas chromatography and their ethanol contents (w/v) at manufacturers' recommended dilutions for use were calculated. The ethanol contents of diluted mouthwashes ranged from < 0.01-23.40% w/v. 27% had ethanol contents > 10% w/v; 9% had ethanol contents > 20% w/v. As the use of the higher ethanol content mouthwashes may be a possible risk factor for oral cancer in frequent or constant users, we believe that the attention of the statutory regulatory authorities should be drawn to this situation.

Ethanol↗
PubMed1994

Productive aging: an overview of the literature.

"Productive aging" describes an array of activities through which older people contribute to society. Both the extent of current productive activities among older people and the barriers to more extensive productive activity are reviewed. If certain adjustments can be made for their special needs, older people have the potential to make substantial contributions. However, a variety of prejudicial attitudes and discriminatory practices continue to limit the opportunities of older people to make productive contributions, particularly in workplace settings. Interventions are needed to strengthen opportunities for retraining, employment, and volunteering for older people. At the same time, programs and policies to facilitate the productive participation of older people cannot easily correct for the adverse effects of a lifetime of racial or gender discrimination.

Aged↗
PubMed1993

Fluctuations in body satisfaction across situations.

Although the variable nature of body image was underscored by Schilder (The image and appearance of the human body. New York: International Universities Press, 1950), few investigators have addressed the stability of body image or its sensitivity to variation in environmental or situational conditions. Most researchers have assumed that body image is a stable characteristic. The present study was designed to investigate the situational specificity of body satisfaction, one facet of body image. One hundred forty-four undergraduate women indicated their degree of body satisfaction in general and in the following four situations: (a) walking by a group of attractive men and women at the beach in a bathing suit, (b) having a conversation with a close female friend over lunch, (c) getting dressed to go to school in privacy, and (d) trying on bathing suits in the dressing room of a department store. Body satisfaction varied significantly across the four situations for all body parts except the face, hair, and hands. Additionally, body satisfaction scores were found to reflect how subjects felt about their bodies when they were being especially self-critical, rather than how they felt in "everyday" situations.

Adolescent↗
PubMed1989

Role of support networks in maintenance of improved cardiovascular health status.

This study was undertaken to clarify the relationship between maintaining an improved cardiovascular health status and social support networks. Two hundred and ninety participants from a national trial that was carried out to specify the impact of reducing risk for cardiovascular disease were rescreened 3 years after completion of the trial. Original risk status of the participants was compared to risk status at the end to identify who had an improved risk status (n = 204). Risk status of 204 improvers was calculated from the rescreening data to identify maintainers (n = 63) and nonmaintainers (n = 143). No significant differences were found between maintainers and nonmaintainers in sociodemographic status, or in level of general support. Highly significant differences were found for four types of support provided specifically for risk reduction: information/advice (P = 0.002), appraisal (P = 0.004), emotional support (P = 0.01) and availability (P = 0.019). Most of these differences in support were accounted for by the larger support network identified by the maintainers. In addition, compared to nonmaintainers, maintainers' networks were more family-centered (P = 0.012), and were correspondingly more dense (P = 0.021). A discriminant function analysis using the significant variables was able to predict maintenance in 72% of the cases. The significant variables also accounted for 10% of the variance between maintainers and nonmaintainers. The implications of this study are: (1) assessment of support should be specific to the health outcome being studied: (2) research on the impact of social environment on health status will benefit from clearly specifying individual components of social support and social networks; (3) amount of social support provided is related to size of the network and relationship of supporter to the at-risk individual; (4) because social support and social networks account for a small but significant amount of the variance between maintainers and nonmaintainers, these concepts should be included in patient assessments prior to developing a treatment or maintenance plan.

Conflict, Psychological↗
PubMed1988

Methodological issues in social support and social network research.

With the plethora of articles describing a relationship between social support and/or social network and health status, it was considered useful to take stock of the current status of research in this area, focusing on two critical methodological issues: clarity of definition, and validity and reliability of the measurement instruments. Of the 33 instruments reviewed only modest agreement was found in conceptual definition, and frequently the concepts were not defined or ill-defined. Of particular concern is the definitional confusion between social support and social network. Variables used to operationalize these concepts confirm this lack of specificity and ambiguity in definition. As for validity and reliability, many of the investigators reported no data on these issues; others provided information that only modestly supported the validity or reliability of their instrument. The conclusion of this assessment suggests the need to clarify the essential elements of social support and social networks in order to better distinguish between the behavioral (support) and structural (network) variables that may be affecting health status. A question is also raised as to the likelihood of a single questionnaire being designed that would accurately measure the perceptions of support or supportive behaviors in the variety of supportive research that will continue to be studied. Finally, more rigorous standards need to be used by investigators in establishing the validity and reliability of the instruments in order to improve their predictive utility.

Data Collection↗