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Biomedical subjects

N Ross

Publications and source records attributed to N Ross.

At least 19 recordsLinked to original sources
PubMed2005

How to measure dietary intake and food habits in adolescence: the European perspective.

AIM: This paper deals with some methodological aspects of data collection in the context of measuring dietary intake in individuals in their adolescence life stage. METHOD: Experiences from three partners of the HELENA project in dietary intake measurement in children and adolescents are presented in this paper with emphasis on characteristics of under-reporting, long-term diet measurement and food patterns (Dortmund DONALD group), influences of survey duration on under-reporting (Ghent group) and meal habits (Spanish AVENA group). RESULTS: Under-reporters in the DONALD Study, particularly female adolescents, had a significantly higher body mass index (BMI) than non-under-reporters; BMI could not be explained by different long-term dietary patterns during childhood and adolescence clustered according to fat consumption; consumers of fast food had higher BMI values than nonconsumers. In the Ghent experience, the decline in population mean energy intake as calculated over selected clusters of days is 184 kcal (6.5%) in boys and 116 (5.6%) in girls; the cluster of 1 recording day and the cluster of 3 recording days were not significantly different but they were both significantly different from the 7-day cluster; no significant interaction was observed between the effect of time and BMI. In the AVENA Study, the percentage of adolescents skipping breakfast was higher in females (8.6%) than in males (3.5%, P<0.001); higher BMI values were observed in those skipping breakfast than in those notskipping breakfast, but differences were statistically significant in males at 15 y and in females at 14 and 17 y; adolescents avoiding some food groups for breakfast had higher BMI values (carbohydrates, fruits and pastries in males and milk, fruits and pastries in females). CONCLUSION: Dietary and nutrient intake data in the HELENA project will be obtained by means of repeated 24-h dietary recalls. Data from HELENA might be a basis for developing complex approaches like Healthy Eating Indices.

Adolescent↗
PubMed2004

Effects of chlorinated solvents on four species of North American amphibians.

Tetrachloroethylene (PCE), a dry cleaning and degreasing solvent, can enter groundwater through accidental leaks or spills, and concentrations as high as 75 mg/L have been reported in Canadian aquifers. Amphibians in wetlands receiving contaminated groundwater may be exposed to PCE and its degradation products, but little information is available on the impacts of these compounds on indigenous amphibian species. Acute (96-h static renewal) exposures to PCE and its major degradation products, trichloroethylene (TCE) and cisand trans-dichloroethylene, were conducted on embryos of four North American amphibian species: wood frogs (Rana sylvatica), green frogs (R. clamitans), American toads (Bufo americanus), and spotted salamanders (Ambystoma maculatum). Subsequently, chronic exposures to PCE and TCE were conducted with the larvae of American toads. Both PCE and TCE were teratogenic to amphibian embryos; median effective concentrations (EC50s) for developmental deformities produced by PCE and TCE exposure for wood frogs and green frogs were 12 and 40 mg/L, respectively. Embryonic survivorship, however, was not compromised at these concentrations. American toads were less sensitive; the EC50 for developmental abnormalities was not attained at the highest test concentrations, 45 and 85 mg/L PCE and TCE, respectively. These results are pertinent in assessing the impact of groundwater pollution on an aquifer-fed wetland.

Amphibians↗
PubMed2002

Timing of surgery for supratentorial aneurysmal subarachnoid haemorrhage: report of a prospective study.

OBJECTIVES: The debate on the timing of aneurysm surgery after subarachnoid haemorrhage (SAH) pivots on the balance of the temporal risk for fatal rebleeding versus the risk of surgical morbidity when operating early on an acutely injured brain. By following a strict management protocol for SAH, the hypothesis has been tested that in the modern arena of treatment for aneurysmal SAH the timing of surgery to secure supratentorial aneurysms does not affect surgical outcome. METHODS: Over a 6 year period, patients admitted with a diagnosis of SAH to a regional neurosurgical unit have been prospectively studied. All have been on a management protocol in which early transfer and resuscitation has been followed regardless of age and clinical condition. Angiographic investigation and surgery have been pursued in those who have been able to at least flex to pain. A total of 1168 patients (60.7% female, mean age 54.3) with proved SAH were received on median day 1 (86.4% arrived within 3 days) of the ictus. Of these, 784 (67.1%) showed aneurysms on angiography and were prepared for surgery. Those who received surgery for a supratentorial aneurysm within 21 days of the ictus were included in the final analysis (n=550). Patients with an initial negative angiogram, with posterior circulation aneurysms, or aneurysms treated by endovascular means, with aneurysms requiring emergency surgery for space occupying haematomas, with aneurysms which re-bled before surgery, and those who received very late surgery (after 21 days from ictus) were excluded. Surgical outcomes at hospital discharge and after 6 months were assessed using the Glasgow outcome score (GOS). Discharge destination and duration of stay in a neurosurgical ward were also documented. The influence of the timing of surgery (early group day 1-3 postictus, intermediate group day 4-10, or late group day 11-21) was analysed prospectively. RESULTS: 60.2% of cases fell into the early surgery group, 32.4% into the intermediate group, and 7.5% into the late operated group. Late surgery was due to delays in diagnosis, transfer, and logistic factors, but not clinical decision. The demographic characteristics, site of aneurysm, and clinical condition of the patients at the time of initial medical assessment were balanced in the three surgical timing groups. There was no significant difference in GOS between the surgical timing groups at 6 months (favourable GOS score 4 and 5: 83.2%, 80.5%, and 83.8% respectively; p=0.47, Kruskal-Wallis test). Outcome was favourable in 84% of patients under 65 years, and 70% in those over 65. The discharge destinations (home, referring hospital, nursing home, rehabilitation centre) showed no significant difference between surgical timing groups. There was no significant difference in mean time to discharge after admission to this hospital from the referring hospital (16.2, 16.2, and 14.6 days for early, intermediate, and late groups respectively; p=0.789, Analysis of variance (ANOVA)). As a result, there was reduction in the mean duration of total hospital inpatient stay in favour of the earliest operated patients (mean time 18.1, 22.0, and 28.3 days respectively; p=0.001. ANOVA showed that besides age, the only determinant of surgical outcome and duration of stay was presenting clinical grade (p<0.0005). CONCLUSION: The current management of patients presenting with SAH from anterior circulation aneurysms allows early surgery to be followed safely regardless of age. The only independent variables affecting outcome are age and clinical grade at presentation. The timing of surgery did not significantly affect surgical outcome, promoting a policy for early surgery that avoids the known risks of rebleeding and reduces inpatient stay.

Adolescent↗
PubMed2001

Characterization of the human Xq21.3/Yp11 homology block and conservation of organization in primates.

The Xq21.3/Yp11 homology block on the human sex chromosomes represents a recent addition to the Y chromosome through a transposition event. It is believed that this transfer of material occurred after the divergence of the hominid lineage from other great apes. In this paper we investigate the structure and evolution of the block through fluorescence in situ hybridisation, contig assembly, the polymerase chain reaction, exon trapping, sequence comparison, and annotation of sequence data. The overall structure is well conserved between the human X chromosome and the Y chromosome as well as between the X chromosomes from different primates. Although the sequence data reveal a high level of nucleotide sequence identity for the human X and Y, there are regions of significant divergence, such as that around the marker DXS214. These are presumably the consequence of multiple rearrangements during evolution and are of particular importance with respect to the potential gene content in this segment of the interval.

Animals↗
PubMed2001

Clogging of a limestone fracture by stimulating groundwater microbes.

Biological clogging is promoted in aquifers either to contain or to remediate groundwater. In this study, an apparatus able to detect small changes in hydraulic conductivity (K) was developed to measure the clogging of a single fracture in limestone, following microbial stimulation. The fracture had a 2.5 mm2 section and was 50 cm long. Prior to the inoculation of the limestone, the sequencing of representative clones from 16S rRNA genes isolated from groundwater, showed significant affiliation with Cytophaga spp., Arcobacter spp. and Rhizobium spp. These bacteria are known to secrete extracellular polymeric substances and form biofilms. When nutrients were added to the inoculated limestone, a decrease in K occurred after 8 days, reaching 0.8% of its initial value after 22 days (Kfi = 340 cm min-1). This study showed that a stimulation of indigenous microbes from groundwater effectively clogged a macrofracture in limestone, suggesting the potential application of biobarriers in fractured rock aquifers.

Arcobacter↗
PubMed2001

Community voices: views on the training of future doctors in Birmingham, UK.

The United Kingdom (UK) population is diverse with nearly 6% minority ethnic communities. Both patients and doctors experience difficulties when dealing with someone from a different ethnic group. Medical education has failed to keep pace with the changing needs of the diverse population. We report a project in which 12 established (religious/cultural and specific interest) community groups expressed their views on what future doctors should learn about serving diverse populations. Data were obtained by group discussion and through the media using a structured format. Fifteen themes emerged which were grouped under three broad themes: firstly, the identification by group members of their perception of the 'differences' in social and cultural beliefs and behaviours of their individual community; secondly, the identification of characteristics of a culturally sensitive doctor; and lastly, recommendations for changes in medical training. New teaching has been introduced to the medical curriculum that incorporates the themes raised by the communities and which reflects consciousness raising and communication issues.

Attitude to Health↗
PubMed2001

Recovering maxillofacial trauma patients: the hidden problems.

This longitudinal study highlights the psychological and functional problems that can result from maxillofacial trauma. This is the first study to report outcome at one year. A total of 147 patients admitted for surgery following facial trauma were recruited over a seven-month period. Three questionnaires were used to record patient-derived levels of dysfunction: the Hospital Anxiety Depression scale, a modified University of Washington Quality of Life questionnaire and five non-validated facial trauma items. At one year 46 patients (31%) responded. Although there were significant improvements in scores from pre-operatively to one year, with all patients being discharged from outpatient follow-up, there was a substantial level of subjective symptomatology. Most notable was the level of anxiety and depression, which were present in 30% of the sample at both time points. Health-care professionals tend to underestimate the long-term effects of maxillofacial trauma. To improve patient care, greater appreciation of these problems is required at the time of initial management.

Adaptation, Psychological↗
PubMed1999

Relation between income inequality and mortality: empirical demonstration.

OBJECTIVE: To assess the extent to which observed associations at population level between income inequality and mortality are statistical artefacts. DESIGN: Indirect "what if" simulation by using observed risks of mortality at individual level as a function of income to construct hypothetical state level mortality specific for age and sex as if the statistical artefact argument were 100% correct. SETTING: Data from the 1990 census for the 50 US states plus Washington, DC, were used for population distributions by age, sex, state, and income range; data disaggregated by age, sex, and state from the Centers for Disease Control and Prevention were used for mortality; and regressions from the national longitudinal mortality study were used for the individual level relation between income and risk of mortality. RESULTS: Hypothetical mortality, while correlated with inequality (as implied by the logic of the statistical artefact argument), showed a weaker association with states' levels of income inequality than the observed mortality. CONCLUSIONS: The observed associations in the United States at the state level between income inequality and mortality cannot be entirely or substantially explained as statistical artefacts of an underlying individual level relation between income and mortality. There remains an important association between income inequality and mortality at state level over and above anything that could be accounted for by any statistical artefact. This result reinforces the need to consider a broad range of factors, including the social milieu, as fundamental determinants of health.

Adult↗
PubMed1999

Folkecology and commons management in the Maya Lowlands.

Three groups living off the same rainforest habitat manifest strikingly distinct behaviors, cognitions, and social relationships relative to the forest. Only the area's last native Maya reveal systematic awareness of ecological complexity involving animals, plants, and people and practices clearly favoring forest regeneration. Spanish-speaking immigrants prove closer to native Maya in thought, action, and social networking than do immigrant Maya. There is no overriding "local," "Indian," or "immigrant" relationship to the environment. Results indicate that exclusive concern with rational self-interest and institutional constraints do not sufficiently account for commons behavior and that cultural patterning of cognition and access to relevant information are significant predictors. Unlike traditional accounts of relations between culture, cognition, and behavior, the models offered are not synthetic interpretations of people's thoughts and behaviors but are emergent cultural patterns derived statistically from measurements of individual cognitions and behaviors.

Anthropology↗
PubMed1999

Community-based clinical education at the University of Birmingham Medical School.

Throughout the United Kingdom, medical schools have begun to make significant changes in the content and delivery of their undergraduate curricula in response to a number of social and educational forces. In particular, many schools have begun to focus increasingly on community-based education. This and other changes mirror developments that have taken place in other countries and in the context of other health care systems, with such forerunners as Harvard, Maastricht, and McMaster having had a fundamental influence. In this article, the authors describe the forces for curricular change in the United Kingdom and the specific recommendations for change made by the General Medical Council. They then discuss in detail the new curriculum at the University of Birmingham medical school, focusing in particular on a community medicine module, where students spend ten days per academic year learning in general medical practices in and around the city of Birmingham.

Clinical Clerkship↗
PubMed1998

Further characterization of the latency-associated transcription unit of Marek's disease virus.

Previous studies have identified a large (L) and a small (S) RNA transcript antisense to the MDV homologue of the ICP4 gene of herpes simplex virus (HSV) in cells infected with Marek's disease virus (MDV) and in lymphoblastoid cell lines. In this study the 5' and 3' ends of the L RNA and of the sense ICP4 transcript of MDV were mapped by Northern hybridization and RNase protection assays. The results showed that L RNA is approximately 10.6 kb and that the ICP4 sense transcript is initiated in the region of genomic DNA where the L RNA terminates whereas L RNA is initiated where the ICP4 transcript terminates. L RNA was abundant in chick embryo fibroblasts (CEF) infected with virus strain HPRS16/attenuated whereas S RNA was predominant in CEF infected with oncogenic HPRS16 and in RPL-1 cell line. Results of cycloheximide experiments showed that the ICP4 gene of MDV was transcribed as an immediate-early gene in infected CEF whereas transcription of the L RNA required protein synthesis. Sequencing of cDNA and Northern hybridization using oligonucleotide probes showed that S RNA shared similar intron/exon boundaries as the cDNAs from several cell lines indicating that there might be a relationship between the S RNA and the antisense transcripts that generated the cDNAs.

Animals↗
PubMed1998

Antiangiogenic properties of a novel shark cartilage extract: potential role in the treatment of psoriasis.

BACKGROUND: A number of inflammatory and immune diseases are associated with vascular changes. Psoriasis, as an example, is a common inflammatory skin disease with dilation of capillaries as an early histological change. In more developed psoriatic lesions there is proliferation of blood vessels and neovascularization. The use of agents that target these vascular changes represents a novel therapeutic strategy in the treatment of inflammatory diseases. Since cartilage is an avascular tissue, it has been hypothesized that there may be factors found in cartilage that inhibit blood vessel formation. OBJECTIVE: The objectives of this study were 1) to determine whether extracts of cartilage could inhibit angiogenesis, and 2) since altered angiogenesis is associated with certain diseases, including psoriasis, to examine whether inhibition of angiogenesis could potentially contribute to the treatment of psoriasis. METHODS: Extracts of shark cartilage were prepared by homogenization and ultrafiltration to derive the active agent termed AE -941. This agent was tested for antiangiogenesis activity using the embryonic vascularization test, which is a modification of the ex vivo chick embryo culture (CAM). Since one of the first steps in angiogenesis is degradation by metalloproteinases of the basement membrane of capillaries, AE -941 was tested for collagenase activity using a fluorogenic peptide substrate. Anti-inflammatory properties were tested using a cutaneous irritation model in humans. RESULTS: A dose dependent inhibition in embryonic neovascularization as well as in collagenase activity by AE -941 was demonstrated. When test compounds were applied on the forearms of test subjects, AE -941 was shown to have anti-inflammatory properties. Anecdotal data suggested that topical AE -941 had a beneficial effect in psoriasis. CONCLUSION: Our results show that AE -941 has anti-angiogenic and anti-inflammatory properties. Antiangiogenesis agents such as AE -941 provide an entirely new class of agents to treat cutaneous and systemic diseases associated with altered vascularity.

Animals↗
PubMed1998

Attitudes toward smoking.

OBJECTIVES: This article examines socio-demographic variations in attitudes about the health effects of smoking, second-hand smoke, and the importance of smoke-free environments. DATA SOURCE: The data are from the Health file of the 1996/97 cross-sectional provincial household component of the National Population Health Survey, conducted by Statistics Canada. The sample consists of 60,260 respondents aged 12 or older. ANALYTICAL TECHNIQUES: Three smoking attitudes scores were derived. Multivariate analyses were used to study how age, sex, educational attainment, province and smoking status were associated with attitude scores. MAIN RESULTS: Smokers placed less emphasis than non-smokers on the health risks associated with smoking. Older Canadians, particularly smokers aged 65 and older, tended to have more lenient attitudes toward smoking, compared with younger age groups. Respondents with high school education or less held more lenient attitudes, compared with those with a university degree. Quebec residents were more tolerant of tobacco use than were residents of other provinces.

Adolescent↗
PubMed1997

Quantification of Marek's disease virus in chicken lymphocytes using the polymerase chain reaction with fluorescence detection.

A quantitative assay was developed for Marek's disease virus (MDV). The assay determines the numbers of viral genomes present in samples by polymerase chain reaction (PCR) amplification of a portion of the viral genome for a restricted number of cycles. Fluorescent-tagged primers are used for the PCR amplification which allows quantification of the fluorescent product. Previously, quantitation of Marek's disease virus has required plaque assays, which are laborious and potentially error-prone, and this had limited quantitative comparisons. The PCR assay is rapid, less laborious and can be applied to high levels of accuracy, since replicate assays can be carried out relatively easily. The PCR-based assay assesses the number of viral genomes present in the sample, rather than the numbers of infected cells measured in the plaque assay, however correlation between the two assays is high, suggesting viral copy number per cell may be rather uniform. In crosses between genetically resistant and susceptible animals the PCR-based assay was correlated significantly with subsequent development of disease, and was a better predictor than the plaque assay of the likelihood of development of pathological disease in the birds studied.

Animals↗
PubMed1997

Marek's disease virus EcoRI-Q gene (meq) and a small RNA antisense to ICP4 are abundantly expressed in CD4+ cells and cells carrying a novel lymphoid marker, AV37, in Marek's disease lymphomas.

Mature lymphomas produced in Rhode Island Red (RIR) chickens infected with the RB1B strain of Marek's disease virus (MDV) were examined for the presence of viral DNA and RNA and expression of viral antigens. In situ hybridization showed that all tumours examined contained viral DNA in areas of lymphoid infiltration. In 3/5 tumours, there was a correlation between the number and distribution of cells expressing the Marek's disease EcoRI-Q gene (meq) and those that carried the lymphoid cell marker AV37. Expression of the MDV-specific phosphoprotein pp38 was infrequent in lymphomas but abundant in a splenic tumour which also expressed the viral glycoprotein gB. Northern blot analysis of lymphocyte fractions purified by immunoaffinity showed that CD4+ and AV37+ fractions from lymphomas expressed meq and the small RNA antisense to ICP4 (SAR). The results are consistent with the notion that transformed cells are CD4+ cells, carrying the AV37 marker and expressing meq and SAR.

Animals↗