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Biomedical subjects

S McCarthy

Publications and source records attributed to S McCarthy.

At least 19 recordsLinked to original sources
PubMed2007

Estimation of exposure to food packaging materials. 3: Development of consumption factors and food-type distribution factors from data collected on Irish children.

There are many initiatives in Europe trying to refine the exposure assessment for food packaging migrants. In the USA, the US Food and Drug Administration (US FDA) uses food consumption and food-type distribution factors to aid the exposure assessment process and generate more realistic estimates of exposure. The present study developed food-consumption factors and food-type distribution factors for Irish children aged 5-12 years from data collected as part of a National Children's Food Survey (NCFS) completed in Ireland in 2003-04, combined with data from the 2003-05 Irish Food Packaging Database and from literature data on surface area-to-weight ratios for food packaging. Consumption factors are defined as the fraction of a person's diet likely to contact a specific food-contact material, while food-type distribution factors reflect the fraction of all food contacting each material that is aqueous, acidic, alcoholic or fatty. In this study, it was found that 'total plastics' had the highest consumption factor of 0.83, while 'total paper and board' had a factor of 0.13 and 'total metal and alloys' had a factor of 0.06. Although it is tentative to compare the US FDA factors with the factors derived in the current study, as the US FDA data are for the total US population, the consumption factor for 'total plastics' in the present study (0.83) was similar to that used by the US FDA (0.79). However, a large difference existed for the consumption factor for 'total metal and alloys' in the Irish data (0.06) and the US FDA data (0.2). In terms of the type of materials used for foods, glass was used mainly for acidic foods (0.67), while plastic was uniformly used for all food types. The food-contact area for plastic packaging for all foods consumed by children was 10.67 dm2/child day(-1), which is slightly lower than the proposed value for the average European consumer of 12.4 dm2/person day(-1). However, this should be expected, as children do not consume as much food as adults. When scenario exposure estimates were made, it was found that when using European Union assumptions, estimates were much larger than when using consumption factors and food-type distribution factors in the exposure assessment, even when conservative assumptions were employed for the consumption factor. This study highlights the potential use of consumption factors and food-type distribution factors in the refinement of the exposure assessment process and how these factors can be calculated using data collected as part of a national food survey.

Child↗
PubMed2006

Estimation of exposure to food-packaging materials. 2: patterns of intakes of packaged foods in Irish children aged 5-12 years.

In the European Union (EU), many assumptions are employed to calculate the intake of migrating chemicals from food packaging. However, very little is known about the actual intake of packaged food, the type of this food and the type of packaging used for this food. The objective of the current study was to examine intakes of packaged food in children aged 5-12 years to provide information on the types of food that are packaged and the type of packaging used. To do this, a food-consumption database, which also recorded information on packaging, was merged with a packaging database, which provided information on the contact layers of packaging. Foods were classified into EU Food categories according to European Council Directive EC 85/575/EEC (European Council 1985), which determined their food type (i.e. aqueous, acidic, alcoholic and fatty). The mean daily intake of all packaged food was 1195 g day-1 with an upper intake of 1959 g day-1 (97.5th percentile); the intake of food packaged in plastic was 993 g day-1 with an upper percentile of 1692 g day-1 (97.5th percentile). The mean daily intake of fat from all packaged food was 62 g day-1, with an upper intake of 100 g day-1 (97.5th percentile). When this was investigated further, it was found that the mean fat intake from packaged 'fatty' foods only was 32 g day-1, with an upper intake of 61 g day-1 (97.5th percentile). The food that contributed most to fat intake was milk. As many food chemical intake assessments are moving towards probabilistic methods, probabilities of a food being packaged and the probability of the type of packaging used were determined. The probability of food being packaged was 0.88. Some foods not 100% packaged included fruit, vegetables, liquid beverages non-alcoholic (includes water) and bread. Probabilities were also derived for the packaging types used for food. It can be concluded that not all the individual assumptions used in the EU exposure assessment are conservative, but in combination they are conservative.

Child↗
PubMed2006

Digital photography.

OBJECTIVE: The emergence of a new generation of "point-and-shoot" digital cameras offers doctors a compact, portable and user-friendly solution to the recording of highly detailed digital photographs and video images. This work highlights the use of such technology, and provides information for those who wish to record, store and display their own medical images. METHODS: Over a 3-month period, a digital camera was carried by a doctor in a busy, adult emergency department and used to record a range of clinical images that were subsequently transferred to a computer database. RESULTS: In total, 493 digital images were recorded, of which 428 were photographs and 65 were video clips. These were successfully used for teaching purposes, publications and patient records. CONCLUSIONS: This study highlights the importance of informed consent, the selection of a suitable package of digital technology and the role of basic photographic technique in developing a successful digital database in a busy clinical environment.

Computers, Handheld↗
PubMed2006

Differential response induced by exposure to low-dose ionizing radiation in SHSY-5Y and normal human fibroblast cells.

Radiation therapy has been used in the treatment of a wide variety of cancers for nearly a century and is one of the most effective ways to treat cancer. Low-dose ionizing radiation (IR) can interfere with cell division of cancer and normal cells by introducing oxidative stress and injury to DNA. The differences in the response to IR-induced DNA damage and increased reactive oxygen species between normal human fibroblasts (NHFs) and cancerous SHSY-5Y cells were considered. H2AX staining and comet assays revealed that NHF cells responded by initiating a DNA repair sequence whereas SHSY-5Y cells did not. In addition, NHF cells appeared to quench the oxidative stress induced by IR, and after 24 h no DNA damage was present. SHSY-5Y cells, however, did not repair their DNA, did not quench the oxidative stress, and showed characteristic signs that they were beginning to undergo apoptosis. These results indicate that there is a differential response between this cancerous and normal cell line in their ability to respond to low-dose IR, and these differences need to be exploited in order to treat cancer effectively. Further study is needed in order to elucidate the mechanism by which SHSY-5Y cells undergo apoptosis following radiation and why these normal cells are better equipped to deal with IR-induced double-strand breaks and oxidative stress.

Adenosine Triphosphate↗
PubMed2005

Role of mitochondria in neuronal cell death induced by oxidative stress; neuroprotection by Coenzyme Q10.

Neuronal cells depend on mitochondrial oxidative phosphorylation for most of their energy needs and therefore are at a particular risk for oxidative stress. Mitochondria play an important role in energy production and oxidative stress-induced apoptosis. In the present study, we have demonstrated that external oxidative stress induces mitochondrial dysfunction leading to increased ROS generation and ultimately apoptotic cell death in neuronal cells. Furthermore, we have investigated the role of Coenzyme Q10 as a neuroprotective agent. Coenzyme Q10 is a component of the mitochondrial respiratory chain and a potent anti-oxidant. Our results indicate that total cellular ROS generation was inhibited by Coenzyme Q10. Further, pre-treatment with Coenzyme Q10 maintained mitochondrial membrane potential during oxidative stress and reduced the amount of mitochondrial ROS generation. Our study suggests that water-soluble Coenzyme Q10 acts by stabilizing the mitochondrial membrane when neuronal cells are subjected to oxidative stress. Therefore, Coenzyme Q10 has the potential to be used as a therapeutic intervention for neurodegenerative diseases.

Cell Death↗
PubMed2004

Paraquat induces oxidative stress and neuronal cell death; neuroprotection by water-soluble Coenzyme Q10.

Neuronal cell death induced by oxidative stress is correlated with numerous neurodegenerative diseases, including Alzheimer's disease (AD), Parkinson's disease (PD), and stroke. The causes of sporadic forms of age-related neurodegenerative diseases are still unknown. Recently, a correlation between paraquat exposure and neurodegenerative diseases has been observed. Paraquat, a nonselective herbicide, was once widely used in North America and is still routinely used in Taiwan. We have used differentiated Human Neuroblastoma (SHSY-5Y) cells as an in vitro model to study the mechanism of cell death induced by paraquat. We observed that paraquat-induced oxidative stress in differentiated SHSY-5Y cells as indicated by an increase in the production of cellular reactive oxygen species (ROS). Furthermore, apoptosis was evident as indicated by cellular and nuclear morphology and DNA fragmentation. Interestingly, pretreatment of SHSY-5Y cells with water-soluble Coenzyme Q10 (CoQ10) before paraquat exposure inhibited ROS generation. Pretreatment with CoQ10 also significantly reduced the number of apoptotic cells and DNA fragmentation. We also analyzed the effect of paraquat and CoQ10 on isolated mitochondria. Our results indicated that treatment with paraquat induced the generation of ROS from isolated mitochondria and depolarization of the inner mitochondrial membrane. Pretreatment with CoQ10 was able to inhibit ROS generation from isolated mitochondria as well as the collapse of mitochondrial membrane potential. Our results indicate that water-soluble CoQ10 can prevent oxidative stress and neuronal damage induced by paraquat and therefore, can be used for the prevention and therapy of neurodegenerative diseases caused by environmental toxins.

Apoptosis↗
PubMed2004

Glucose self-monitoring in primary care: a survey of current practice.

BACKGROUND: The role of long-term glycaemic control in minimizing long-term complications of diabetes mellitus is evidence-based and national guidelines recommend a target glycosylated haemoglobin level of approximately 7%. Although the role of self-monitoring blood and urine glucose is less well defined, this activity consumes vast National Health Service (NHS) resources. AIMS: The aims of this study were to (i) determine the current practice of glucose self-monitoring in primary care, (ii) determine any changes to therapy made as a result and (iii) compare monitoring and frequency of monitoring in those patients using insulin with those patients taking oral hypoglycaemic agents. METHODS: Postal questionnaire to 311 patients using insulin or oral hypoglycaemic agents identified from three general practices. RESULTS: The response rate was 59.8% (186/311), with the majority of responding patients (n = 158, 87.3%) performing self-monitoring. The patients using insulin were more likely to be self-monitoring than those taking oral therapy (chi(2), P < 0.001, d.f. = 1). The majority of patients who self-monitored and were using insulin (n = 45, 61.1%) altered the dose of insulin if a reading was beyond their target range. However, the majority of patients who self-monitored and were taking oral therapy (n = 48, 68.6%) took no action at all. CONCLUSIONS: Blood glucose self-monitoring was common in those treated with insulin or oral hypoglycaemics, although those using insulin were more likely to self-monitor. Notably many patients, particularly those on oral therapy, took no action based on the results of self-monitoring.

Administration, Oral↗
PubMed2003

Epiphyseal osteoblastoma-like osteosarcoma.

Osteoblastoma-like osteosarcoma is a rare variant of osteosarcoma occurring in this instance in a highly unusual location: the lateral femoral condyle of a 13-year-old girl. The radiological features were non-aggressive and, although slightly unusual, were most suggestive of chondroblastoma.

Adolescent↗
PubMed2001

Physical activity patterns in a nationally representative sample of adults in Ireland.

OBJECTIVE: To evaluate habitual levels of physical activity in a nationally representative sample of adults in Ireland. DESIGN: Cross-sectional survey using a self-administered questionnaire. Usual levels of work, recreational and household activities were evaluated in relation to anthropometric, demographic and socio-economic characteristics. The amount and intensity of all activities were quantified by assigning metabolic equivalents (METS) to each activity. SETTING: Republic of Ireland and Northern Ireland, 1997-1999. SUBJECTS: Random sample of 1379 adults aged 18-64 years. RESULTS: Men were approximately twice as active in work and recreational activity (139.7 +/- 83.9 METS) as women (68.5 +/- 49.8 METS; P<0.001) but women were three times more active in household tasks (65.9 +/- 58.7 METS vs. 22.6 +/- 24.6 METS; P<0.001). Overall levels of physical activity declined with increasing age, particularly leisure activity in men. In women the decline in work activity was offset by spending more time in household pursuits. Twenty-five per cent of the subjects were extremely overweight (body mass index (BMI>28 kg m(-2)) or obese (BMI >30 kg m (-2)). Fewer obese subjects reported higher levels of work and leisure activities. However, a higher percentage of obese women reported participation in the higher levels of household activities. Participation rates in recreational activities were low. Walking was the most important leisure activity of both men (41%) and women (60%). In terms of hours per week spent in vigorous physical activity, men were more active than women, professional and skilled non-manual women were more active than women in other social classes, and younger subjects (aged 18-35 years) were more active than older subjects. CONCLUSIONS: The holistic approach used in the assessment of physical activity in this study has revealed important and subtle differences in the activity patterns of men and women. Failure to fully characterise the respective activity patterns of men and women could lead to ill-informed public health policy aimed at promoting and sustaining lifetime habits of physical activity. The results suggest that simple population-focused programmes to promote physical activity are unlikely to offer the same chance of long-term success as more sensitive and individualised strategies.

Adolescent↗
PubMed2000

Isolation and characterization of the notch ligand delta4.

Notch signaling plays a critical role in a variety of developmental programs. In vertebrates, the complexity of the process is underscored by the existence of multiple Notch receptors and multiple ligands, each of which displays a distinct expression profile. Furthermore, the ligands can be subdivided into two families, the Serrate/Jagged family and the Delta family. Here we present the isolation of a novel Notch ligand, Delta4. Expression analyses indicate that mouse Delta4 is highly expressed in the eye and lung during embryogenesis and in the heart, lung, liver, and kidney of the adult. Functionally, Delta4 is indistinguishable from Jagged1 in its abilities to inhibit myogenesis and to stimulate transcription through Notch1 and the DNA binding protein CSL.

3T3 Cells↗
PubMed2000

Hyperphosphorylated tau and neurofilament and cytoskeletal disruptions in mice overexpressing human p25, an activator of cdk5.

Hyperphosphorylation of microtubule-associated proteins such as tau and neurofilament may underlie the cytoskeletal abnormalities and neuronal death seen in several neurodegenerative diseases including Alzheimer's disease. One potential mechanism of microtubule-associated protein hyperphosphorylation is augmented activity of protein kinases known to associate with microtubules, such as cdk5 or GSK3beta. Here we show that tau and neurofilament are hyperphosphorylated in transgenic mice that overexpress human p25, an activator of cdk5. The p25 transgenic mice display silver-positive neurons using the Bielschowsky stain. Disturbances in neuronal cytoskeletal organization are apparent at the ultrastructural level. These changes are localized predominantly to the amygdala, thalamus/hypothalamus, and cortex. The p25 transgenic mice display increased spontaneous locomotor activity and differences from control in the elevated plus-maze test. The overexpression of an activator of cdk5 in transgenic mice results in increased cdk5 activity that is sufficient to produce hyperphosphorylation of tau and neurofilament as well as cytoskeletal disruptions reminiscent of Alzheimer's disease and other neurodegenerative diseases.

Age Factors↗
PubMed2000

Interaction of exogenous DNA with the nuclear matrix of live spermatozoa.

Sperm chromatin is a highly organized array of protamines and DNA, with the protamines serving to tightly condense the DNA into a compact, defined structure. We have previously demonstrated that the sperm nucleus is an ordered library of DNA organized into functional zones, such as the nuclear matrix and nuclear annulus. Other laboratories have suggested that mouse spermatozoa can interact with exogenous pSV2CAT plasmid DNA. In this work, we explored this interaction and examined the subcellular localization of the exogenous DNA. We found a repeatable association of exogenous DNA with a specific region of the sperm nuclear matrix. This region of the nucleus correlates with the equatorial segment of the sperm head. This interaction requires only a defined fertilization media, transfection quality DNA, and incubation with spermatozoa.

Animals↗
PubMed2000

Telangiectatic dedifferentiation of a parosteal osteosarcoma.

A unique case of parosteal osteosarcoma (POS) of the proximal femur, with areas of telangiectatic dedifferentiation, in a 28-year-old woman is reported. The patient had a 7-week history of pain and swelling in her right thigh. A biopsy diagnosis of POS was established. The patient was treated with two cycles of intraarterial chemotherapy, followed by limb salvage surgery. Histological examination of the resected specimen showed POS with areas of dedifferentiation composed of highgrade telangiectatic osteosarcoma with associated secondary aneurysmal bone cyst change.

Adult↗
PubMed2000

Structural genomics in the biotechnology sector.

Commercial efforts in structural genomics focus on providing to pharmaceutical customers information that relates to the suitability of specific proteins as drug targets and the informed selection and refinement of lead compounds generated by high-throughput screening and rational approaches. These efforts follow a variety of business models and are impacted by activities in the public domain, recent technological advances, and the changing intellectual property landscape.

Animals↗
PubMed2000

Risk behaviours for HIV and hepatitis infection among anabolic-androgenic steroid users.

This study examined HIV and hepatitis risk behaviours among anabolic-androgenic steroid (AAS) users and controls, providing a detailed assessment of both injection and sexual practices. Fifty AAS-using and 40 non-AAS-using weight trainers completed a semi-structured interview followed by a detailed questionnaire. The 'high risk' behaviour of sharing needles and syringes was not current practice among the AAS-using sample, with only one user reporting sharing injecting equipment in the past. However, for some users it was common practice to share multi-dose vials (19%) and to divide drugs using syringes (17%). Both these practices are potential routes for HIV and hepatitis infection. Significantly more AAS users (36%) reported increases in sex drive over the last three months than did the control subjects (5%). More AAS users than controls were engaging in sex with more than one partner while infrequently using condoms. These findings support the maintenance of needle exchange schemes which are essential to continued safe injecting practices among AAS users. The elevated sexual risk behaviour of AAS users could be due to AAS's effect of increasing sex drive or to a 'risk taking' personality trait among AAS users.

Adolescent↗
PubMed2000

International variations in youth drug use: the effect of individual behaviours, peer and family influences, and geographical location.

This international study investigates factors underlying international variations in rates of youth drug use among representative samples of 15-year-olds in five cities (Bremen, n = 871; Dublin, n = 983; Groningen, n = 487; Newcastle upon Tyne, n = 880; Rome, n = 666). It reveals a higher level of drug use in English-speaking compared to continental populations. Drug use was associated with peer, family and individual factors. Logistic regression showed that family structure and sport were associated with lower rates and delinquent behaviour with higher rates of drug use in all cities and among males and females. Among males, city of residence also independently predicted drug use. The effect of traditional families and studiousness in reducing drug use was most evident for male drug use in low-use cities: higher rates of use in English-speaking cities appear partially due to the drug use of low-risk males.

Adolescent↗