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Biomedical subjects

R Cartwright

Publications and source records attributed to R Cartwright.

At least 19 recordsLinked to original sources
PubMed2002

Exposure to power frequency electric fields and the risk of childhood cancer in the UK.

The United Kingdom Childhood Cancer Study, a population-based case-control study covering the whole of Great Britain, incorporated a pilot study measuring electric fields. Measurements were made in the homes of 473 children who were diagnosed with a malignant neoplasm between 1992 and 1996 and who were aged 0-14 at diagnosis, together with 453 controls matched on age, sex and geographical location. Exposure assessments comprised resultant spot measurements in the child's bedroom and the family living-room. Temporal stability of bedroom fields was investigated through continuous logging of the 48-h vertical component at the child's bedside supported by repeat spot measurements. The principal exposure metric used was the mean of the pillow and bed centre measurements. For the 273 cases and 276 controls with fully validated measures, comparing those with a measured electric field exposure >/=20 V m(-1) to those in a reference category of exposure <10 V m(-1), odds ratios of 1.31 (95% confidence interval 0.68-2.54) for acute lymphoblastic leukaemia, 1.32 (95% confidence interval 0.73-2.39) for total leukaemia, 2.12 (95% confidence interval 0.78-5.78) for central nervous system cancers and 1.26 (95% confidence interval 0.77-2.07) for all malignancies were obtained. When considering the 426 cases and 419 controls with no invalid measures, the corresponding odds ratios were 0.86 (95% confidence interval 0.49-1.51) for acute lymphoblastic leukaemia, 0.93 (95% confidence interval 0.56-1.54) for total leukaemia, 1.43 (95% confidence interval 0.68-3.02) for central nervous system cancers and 0.90 (95% confidence interval 0.59-1.35) for all malignancies. With exposure modelled as a continuous variable, odds ratios for an increase in the principal metric of 10 V m(-1) were close to unity for all disease categories, never differing significantly from one.

Adolescent↗
PubMed2001

Low NAD(P)H:quinone oxidoreductase 1 activity is associated with increased risk of acute leukemia in adults.

NAD(P)H:quinone oxidoreductase 1 (NQO1) is an enzyme that detoxifies quinones and reduces oxidative stress. A cysteine-to-threonine (C --> T) substitution polymorphism at nucleotide 609 of the NQO1 complementary DNA (NQO1 C609T) results in a lowering of NQO1 activity. Individuals homozygous for this mutation have no NQO1 activity, and heterozygotes have low to intermediate activity compared with people with wild type. DNA samples from 493 adult de novo acute leukemia patients and 838 matched controls were genotyped for NQO1 C609T. The majority of cases were diagnosed as acute myeloid leukemia (AML) (n = 420); 67 as acute lymphoblastic leukemia (ALL); and 6 as other forms of acute leukemia. The frequency of cases with low or null NQO1 activity (heterozygote + homozygous mutant) was significantly higher among total acute leukemia case subjects compared with their matched controls (odds ratio [OR] = 1.49; 95% confidence interval [CI], 1.17-1.89). Both ALL (OR = 1.93; 95% CI, 0.96-3.87) and AML case subjects (OR = 1.47; 95% CI, 1.13-1.90) exhibited a higher frequency of low or null NQO1 genotypes than controls. For de novo AML, the most significant effect of low or null NQO1 activity was observed among the 88 cases harboring translocations and inversions (OR = 2.39; 95% CI, 1.34-4.27) and was especially high for those harboring inv(16) (OR = 8.13; 95% CI, 1.43-46.42). These findings were confirmed in a second group of 217 de novo AML cases with known cytogenetics. Thus, inheritance of NQO1 C609T confers an increased risk of de novo acute leukemia in adults, implicating quinones and related compounds that generate oxidative stress in producing acute leukemia.

Acute Disease↗
PubMed2001

Temperature-controlled radiofrequency tissue volume reduction in the human soft palate.

OBJECTIVE: To validate the use of temperature-controlled radiofrequency energy applied to the soft palate in a multicenter setting for reduction of snoring in a minimally morbid manner. METHODS: Prospective, nonrandomized multicenter study of 113 patients who had a respiratory disturbance index less than 15 and minimum oxygen saturation not less than 85% and who were seeking treatment for habitual disruptive snoring. Patients were given either single or multiple lesions to the soft palate during each treatment session. RESULTS: Patients received 1978 J on average with an overall average of 2.4 treatments. Snoring scores went from an average of 7.8 (visual analog scale (VAS), 0-10) pretreatment to 3.2 posttreatment. Pain was minimal, averaging 1.7 (VAS 0-10) on days 1 to 6. Complications were few and transient, and mild. CONCLUSIONS: The multiple lesion protocol was the most successful; reducing snoring from 7.6 to 2.7, on a VAS with an average of 1232 J delivered over 1.6 treatments. Temperature-controlled radiofrequency was found to be a minimally invasive, well-tolerated procedure that was safe and efficacious in this study group.

Adult↗
PubMed2001

Ground zero.

Explore the source record for details and available documents.

Aircraft↗
PubMed2000

Sleep-related violence: does the polysomnogram help establish the diagnosis?

With the growing number of legal cases of sleep-related violence coming to public attention, and the development of sleep medicine as an area of expertise, sleep clinicians are being turned to for help in discriminating those violent individuals who sustain a diagnosis of adult parasomnia of the arousal disorder type, (sleep walking, 307.46-0, sleep terrors 307.46-1, or confusional arousals 307.46-2) according to the International Classification of Sleep Disorders (The International Classification of Sleep Disorders: revised: diagnostic and coding manual. Rochester MN, American Sleep Disorders Association, 1997) from those whose episode of violence may have been carried out with full waking consciousness, or as the result of an impairment of judgement due to some psychiatric or neurological disorder. Clearly there is need to refine the diagnostic characteristics to resolve some of the contradictory descriptions of this disorder in the present literature. There is also the question whether the classical overnight polysomnogram is helpful in making this differential diagnosis, and if so, how should it be done to be maximally useful and what other testing is indicated.

Journal Article↗
PubMed2000

Residential radon exposure and adult acute leukaemia.

Exposure to radioactive radon gas in homes, from natural sources, is an important public-health issue for many countries. We found no association between household exposure to radon and leukaemia in adults in the UK.

Acute Disease↗
PubMed2000

Polymorphic variation within the glutathione S-transferase genes and risk of adult acute leukaemia.

Polymorphisms within the phase II metabolizer enzymes GST T1, GST M1 and GST P1 affect the body's ability to detoxify a range of potential leukaemogens encountered in the environment. Using PCR, GST T1, GST M1 and GST P1 genotypes were determined in 557 adults with acute leukaemia and 952 age, sex and geographically matched controls. The strongest association with acute leukaemia was observed for the GST T1 null genotype, which occurred among 19% of cases and 14% of controls [odds ratio (OR) 1.45, 95% confidence interval (CI) 1.09-1.93]. A slightly higher proportion of cases (53%) than controls (49%) displayed the GST M1 null genotype, although the difference was not statistically significant (OR 1.22, 95% CI 0.98-1.52). No effect was observed for the GST P1 genotype and no interaction between the GST T1 and GST M1 genotypes was evident. Acute myeloid leukaemia (AML) was weakly associated with both GST T1 null (OR 1.32, 95% CI 0.97-1.79) and GST M1 null (OR 1. 24, 95% CI 0.98-1.56), whereas acute lymphoblastic leukaemia (ALL) was associated with GST T1 null (OR 3.28, 95% CI 1.31-8.26). No associations between smoking and disease risk in relation to GST T1 and GST M1 polymorphic status were found.

Adolescent↗
PubMed2000

Treatments for snoring: a comparison of somnoplasty and an oral appliance.

OBJECTIVES: Objectives of the study are 1) to test the effectiveness of somnoplasty (radiofrequency volumetric tissue reduction of the soft palate) for the control of loud, socially disruptive, snoring; 2) to test the long-term efficacy of this treatment by spouse report; and 3) to compare the effectiveness of somnoplasty with another treatment. STUDY DESIGN: Twenty patients with complaints of loud snoring and a respiratory disturbance index no greater than 15 respiratory events per hour with sleep-related episodes of oxygen desaturation no lower than 80% were offered an experimental treatment. Ten were treated with somnoplasty, and a comparison group of 10 matched patients used an oral appliance. All were restudied in the laboratory wearing a device programmed to count minutes of sleep during which snoring was loud, soft, or absent. METHODS: For the 10 somnoplasty patients, a spouse rating of snoring determined whether the patient received one or more treatments. Five patients had a single treatment to three sites, and five others had two such treatments. Ten patients wore an oral appliance of the tongue-retaining type (Snore X, Fremont, CA). RESULTS: Seven of the 10 somnoplasty patients met the improvement criteria set for reduced loud snoring (a spouse rating of 3 or less on a 10-point scale, and 10% or less of sleep time in loud snoring in the laboratory). The comparison group also had a significant improvement in the percentage of sleep time in loud snoring while wearing the Snore X appliance. CONCLUSION: Since there was no significant difference between the two groups in percentage of sleep time spent in loud snoring while treated, the choice of method to control snoring must be based on factors other than efficacy.

Humans↗
PubMed2000

Poor metabolizers at the cytochrome P450 2D6 and 2C19 loci are at increased risk of developing adult acute leukaemia.

We have genotyped over 550 cases of acute leukaemia and 950 matched controls from a population-based case-control study, to investigate the impact cytochrome P450s 2D6, 2C19 and 1A1 have on susceptibility to adult acute leukaemia. Analysis included potential associations between polymorphic status and acute myeloid leukaemia (AML), acute lymphoblastic leukaemia (ALL), plus the FAB and cytogenetic subtypes therein. A significant increased risk was found for CYP2D6 poor metabolizer phenotype and acute leukaemia [odds ratio (OR) = 1.69, 95% confidence interval (CI) 1.17-2.43], a risk also found in AML and ALL. No interaction was found with smoking. However, a significant age-related association between CYP2D6 polymorphism and acute myeloid leukaemia implied that the excess risk was confined to persons aged 40 years and over (OR 2.38, 95% CI 1.53-3.71). Amongst AML cases, increased odds ratios were observed in both de-novo (OR 1.54, 95% CI 1.02-2.32) and secondary leukaemia (OR 2.83, 95% CI 0.91-8.77), and among patients with a chromosomal abnormality (OR 2.00, 95% CI 1.11-3.61). An increased risk was found for the CYP2C19 poor metabolizer phenotype (OR 1.68, 95% CI 0.97-2.92) which was also present in AML and ALL. For this CYP450 locus, an increased risk was suggested in secondary leukaemia (OR 2.67, 95% CI 0.44-16.3) and amongst AML cases with a chromosomal abnormality (OR 6.72, 95% CI 2.22-20.4). No difference in CYP1A1 genotype distribution was found for acute leukaemia, AML, ALL or any other diagnostic classification group used. No significant interactions between CYP2D6, CYP2C19 or CYP1A1 were found.

Acute Disease↗
PubMed1999

The rise in incidence of lymphomas in Europe 1985-1992.

A collaborative study was carried out of the descriptive epidemiology of the lymphomas from seven countries across Europe in the period 1985-1992. Careful attention was paid to sources of information and the data quality in close collaboration with expert histopathologists. The data were classified as non-Hodgkin's lymphoma (NHL) and Hodgkin's disease (HD). An attempt was made to put the data into a modified version of the Revised European American Lymphoma (REAL) classification. We observed an overall rise in total NHL throughout the time period in all European countries but no such trend in HD. The increase in NHL overall being 4.2% per annum, representing an increase of 4.8% in males and 3.4% in females per annum, was only marked in middle and old age. Such increases were observed in all participating areas except in Burgundy. Different countries, however, have different base rates, the rates being highest in Scandinavia and the Netherlands. The analysis by subcategory classification suggested that the increase in NHL was confined to the follicle centre cell type, extranodal B-cell, nodal T-cell and nodal lymphomas not otherwise specified, categories. These new observations present a picture of real increase in case incidence with no obvious explanation. The increases in NHL do not appear to be due solely to better diagnoses. Pending other explanations or refutation, these present a compelling picture of an inexorable rise in incidence of this disease.

Adolescent↗
PubMed1999

Tobacco and the risk of acute leukaemia in adults.

Self-reported smoking histories were collected during face-to-face interviews with 807 patients with acute leukaemia and 1593 age- and sex-matched controls. Individuals who had smoked regularly at some time during their lives were more likely to develop acute leukaemia than those who had never smoked (odds ratio (OR) = 1.2, 95% confidence interval (CI) 1.0-1.4). The association was strongest for current smokers, defined here as smoking 2 years before diagnosis (OR = 1.4, 95% CI 1.1-1.7). With respect to the numbers of years smoked, risk estimates were raised in all groups except those who had smoked for fewer than 10 years. Similarly, the odds ratio decreased as the number of years 'stopped smoking' increased, falling to one amongst those who had given up smoking for more than 10 years. No significant linear trends were found, however, with either the numbers of years smoked or the numbers of years stopped smoking, and no significant differences were found between AML and ALL.

Acute Disease↗
PubMed1999

A quest for seasonality in presentation of leukaemia and non-Hodgkin's lymphoma.

The literature on presentation of seasonality of leukaemia fails to provide clear conclusions. Using the Data Collection Study organised by the Leukaemia Research Fund (LRF) Centre for Clinical Epidemiology, University of Leeds, this question was re-examined. This data has a high level of ascertainment and is population based. The results were mainly negative, there being no fit to a sinusoidal curve (Cosinor analysis) in any part of the data. Using normal approximation to Poisson there were individual months with positive findings. Such a method could not be specifically depended on to provide reliable conclusions, nevertheless, further work in this area is justified. Non-Hodgkin's lymphoma was also examined but again with mainly negative findings.

Acute Disease↗
PubMed1998

Role of REM sleep and dream affect in overnight mood regulation: a study of normal volunteers.

To test that REM sleep and/or dreaming aid in the overnight regulation of negative mood, 60 student subjects, selected to have no current or past episodes of depression, were tested with the Profile of Mood States (POMS) before and after two nights of laboratory sleep. There was a significant overnight effect of sleep on the Depression scale (Dep) both on a sleep-through night and a night of REM awakenings for dream recall. Pre-sleep Dep was significantly correlated with the affect in the first REM report. Although Dep scores were truncated due to the screening criteria, a subgroup of the 10 highest scorers differed from the 50 low scorers in the distribution of dream affect categories across the night. Low scorers displayed a flat distribution of positive and negative affect in dreams, while those with some pre-sleep depressed mood showed a pattern of decreasing negative and increasing positive affect in dreams reported from successive REM periods. This suggests that dreaming may actively moderate mood overnight in normal subjects.

Adult↗
PubMed1998

Role of REM sleep and dream variables in the prediction of remission from depression.

To test the hypothesis that REM sleep and/or dreams contribute to overnight mood regulation, 61 subjects were tested on the Beck Depression Inventory (BDI), and for 3 nights of monitored sleep on two occasions, once close to, and 1 year after, a marital separation. Forty-nine percent of the variance in the follow-up BDI could be accounted for by the initial BDI score, and three sleep and dream variables associated with the mood regulatory hypothesis: eye movement density in the first REM, strength of the affect in the first dream and total number of negative dreams recalled from REM awakenings. Among the 39 who met BDI depression criteria initially, 71.8% could be classified correctly as remitted or not remitted at follow-up by discriminant function analysis based on the presence of negative dreams the first vs. second half of the night. Subjects reporting more negative dreams at the beginning and fewer at the night's end were more likely to be in remission 1 year later than were those with fewer negative dreams at the beginning and more at the end of the night. Early negative dreams may reflect a within-sleep mood regulation process taking place, while those that occur later may indicate a failure in the completion of this process.

Adult↗
PubMed1998

The XRCC2 DNA repair gene from human and mouse encodes a novel member of the recA/RAD51 family.

We recently identified a positional candidate for the XRCC2 DNA repair gene at human chromosome 7q36.1. We have now cloned the cDNA for this gene from both human and mouse and show that it is a highly conserved novel member of the recA / RAD51 recombination repair gene family. The cDNA is able to complement significantly the phenotype of a unique cell line, irs1 , which shows extreme sensitivity to DNA cross-linking agents and genetic instability. Thisphenotype is consistent with a role for the XRCC2 gene in recombination repair in somatic cells, suggesting that in addition to RAD51 , other members of this gene family have an important function in high fidelity repair processes in mammals. Despite this function, the XRCC2 gene transcript is expressed at a very low level in somatic tissue, but is elevated in mouse testis, suggesting an additional role in meiosis.

Amino Acid Sequence↗