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D Bull

Publications and source records attributed to D Bull.

At least 19 recordsLinked to original sources
PubMed2001

Malignant neoplasms of the brain during childhood: the role of prenatal and neonatal factors (United Kingdom).

OBJECTIVES: To evaluate whether factors in pregnancy and around birth influence the risk of childhood malignant neoplasms of the brain or other parts of the nervous system. METHODS: The distribution of certain characteristics of pregnancy and birth among 83 cases of malignant neoplasms of the brain and other parts of the nervous system (diagnosed between 0 and 14 years of age) and 166 controls (individually matched on date of birth, sex, and hospital of birth) were compared. Odds ratios (OR), 95% confidence intervals (95% CI) and two-sided p-values were calculated using conditional logistic regression for matched sets. RESULTS: Children whose mothers had documented evidence of a clinically diagnosed viral infection during pregnancy had an approximately 11-fold increase in risk of developing a malignant neoplasm of the brain or other part of the nervous system (OR = 10.6, 95% CI = 1.1-503.2). In addition, non-statistically significant increased risks were observed among children who had a non-cephalic presentation (OR = 3.3, 95% CI = 0.8-13.9) or a low 1-minute apgar score (OR = 2.7, 95% CI = 1.0-7.4). No other aspects of the index pregnancy, delivery, or maternal characteristics were associated with an increased risk of childhood brain tumors. CONCLUSIONS: The results reported here provide limited evidence for the role of prenatal and neonatal factors in the etiology of childhood malignant neoplasms of the brain. The finding for maternal viral infection during pregnancy warrants further investigation.

Adolescent↗
PubMed2001

Randomized trial of nasal synchronized intermittent mandatory ventilation compared with continuous positive airway pressure after extubation of very low birth weight infants.

OBJECTIVE: To determine whether noninvasive, nasal synchronized intermittent mandatory ventilation (nSIMV) improves the likelihood that very low birth weight infants will be successfully extubated. METHODS: Infants of <1251-g birth weight who were due to be extubated before 6 weeks of age were eligible once they were receiving <35% oxygen and were on a ventilator rate of <18 breaths per minute (bpm). Extubation was performed following intravenous loading with aminophylline, after a successful trial of 12 hours of endotracheal synchronized intermittent mandatory ventilation at a rate of 8. Infants were randomized to either nasal continuous positive airway pressure (nCPAP) at 6 cm H(2)O or nSIMV after extubation. nSIMV was commenced at a rate of 12 bpm with pressure on the ventilator set to achieve a delivered pressure of at least 12 cm H(2)O and a peak end expiratory pressure of 6 cm H(2)O. Continuous recording for diagnosis of apnea was performed for 72 hours after extubation. Objective criteria for failure of extubation were as follows: a PaCO(2) >70; FIO(2) >0.7; or severe recurrent apnea (>2 apneas requiring intermittent positive-pressure ventilation in 24 hours or >6 apneas >20 seconds per day). The study ended after 72 hours postextubation or when infants satisfied failure criteria. A sample size of 54 was determined by power analysis. RESULTS: Mean birth weight (831 standard deviation [SD]: 193 g) and gestation (26.3 SD: 1.8 weeks) did not differ between groups. Mean age at extubation was 7.6 (SD: 9.7) days, range 1 to 40 days. The nSIMV group had a lower incidence of failed extubation 4/27 compared with the continuous positive airway pressure group, 12/27. This was attributable to both a decreased incidence of apnea and a decreased incidence of hypercarbia. There was no increase in the incidence of abdominal distension or feeding intolerance. DISCUSSION: nSIMV is effective in preventing extubation failure in very low birth weight infants in the first 72 hours after extubation. Noninvasive ventilation may have other roles in the care of the very low birth weight infant.

Aminophylline↗
PubMed2000

The spectrum of HIV-1 related cancers in South Africa.

Despite the high prevalence of infection by the Human Immunodeficiency Virus (HIV) in South Africa, information on its association with cancer is sparse. Our study was carried out to examine the relationship between HIV and a number of cancer types or sites that are common in South Africa. A total of 4,883 subjects, presenting with a cancer or cardiovascular disease at the 3 tertiary referral hospitals in Johannesburg, were interviewed and had blood tested for HIV. Odds ratios associated with HIV infection were calculated by using unconditional logistic regression models for 16 major cancer types where data was available for 50 or more patients. In the comparison group, the prevalence of HIV infection was 8.3% in males and 9.1% in females. Significant excess risks associated with HIV infection were found for Kaposi's sarcoma (OR=21.9, 95% CI=12.5-38.6), non-Hodgkin lymphoma (OR=5.0, 95%CI=2.7-9.5), vulval cancer (OR=4.8, 95%CI= 1.9-12.2) and cervical cancer (OR= 1.6, 95%CI= 1.1-2.3) but not for any of the other major cancer types examined, including Hodgkin disease, multiple myeloma and lung cancer. In Johannesburg, South Africa, HIV infection was associated with significantly increased risks of Kaposi's sarcoma, non-Hodgkin lymphoma and cancers of the cervix and the vulva. The relative risks for Kaposi's sarcoma and non-Hodgkin lymphoma associated with HIV infection were substantially lower than those found in the West.

Acquired Immunodeficiency Syndrome↗
PubMed1999

Antibodies against human herpesvirus 8 in black South African patients with cancer.

BACKGROUND: Infection with human herpesvirus 8 (HHV-8) has been consistently linked to Kaposi's sarcoma, but its mode of transmission, association with other cancers, and interaction with the human immunodeficiency virus type 1 (HIV-1) are largely unknown. METHODS: Between January 1992 and December 1997, we interviewed 3591 black patients with cancer in Johannesburg and Soweto, South Africa. Blood was tested for antibodies against HIV-1 and HHV-8 in 3344 of the patients. Antibodies against HHV-8 were detected with an indirect immunofluorescence assay. The intensity of the fluorescent signal correlated well with the titers of antibodies (P<0.001). The relations among the presence of anti-HHV-8 antibodies, sociodemographic and behavioral factors, type of cancer, and the presence or absence of coexistent HIV infection were examined with the use of unconditional logistic-regression models. RESULTS: Among the 3293 subjects with cancers other than Kaposi's sarcoma, the standardized seroprevalence of antibodies against HHV-8 was 32 percent, which did not differ significantly from the standardized seroprevalence among black blood donors. Among these 3293 patients, the prevalence of antibodies against HHV-8 increased with increasing age (P<0.001) and an increasing number of sexual partners (P=0.05) and decreased with increasing years of education (P=0.007); it was not strongly associated with HIV-1 infection. Anti-HHV-8 antibodies were more frequent among black than white blood donors (P<0.001). Among the 51 patients with Kaposi's sarcoma, the standardized seroprevalence of antibodies against HHV-8 was 83 percent, significantly higher than the prevalence among those without Kaposi's sarcoma (P<0.001). For 16 other specific types of cancer, including multiple myeloma (108 cases) and prostate cancer (202 cases), the variation in the standardized seroprevalence of antibodies against HHV-8 was not remarkable. At a given intensity of fluorescence of anti-HHV-8 antibodies, Kaposi's sarcoma was more frequent among HIV-1-positive patients than among those who were HIV-1-negative (P<0.001). CONCLUSIONS: Among black patients with cancer in South Africa, the seroprevalence of anti-HHV-8 antibodies is high and is specifically associated with Kaposi's sarcoma, particularly at high titers.

Adolescent↗
PubMed1999

Low back pain in a population of school children.

A study was undertaken to analyse the prevalence of low back pain (LBP) and confounding factors in primary school children in the city of Antwerp. A total of 392 children aged 9 were included in the study. All children completed a validated three-page questionnaire and they all underwent a specific lumbar spine oriented medical examination during their annual routine medical school control. This examination was performed by the city school doctors. The questionnaire was composed of easy "yes/no" questions and visual analogue scales. Statistical analysis was performed using Student's t-test and chi-squared test at the significance level P < 0.05. The prevalence of LBP was high. No gender difference was found. A total of 142 children (36%) reported having suffered at least one episode of LBP in their lives. Of these, 33 (23%) had sought medical help for LBP from a doctor or physiotherapist. Sixty-four percent of children reporting LBP said that at least one of their parents suffered from or complained of LBP. This was significantly higher than for the children who did not report having suffered LBP. The way in which the school satchel was carried (in the hand, on the back) had no bearing on the incidence of LBP. There was significantly more LBP in children who reported playing video games for more than 2 h per day, but this was not so for television watchers. The visual analogue scales concerning general well-being were all very significantly correlated with self-reported LBP, with children who reported LBP being more tired, less happy, and worse sleepers. Of the 19 clinical parameters taken down during the medical examination, only one was significantly more prevalent in the group of children reporting LBP: pain on palpation at the insertion site on the iliac crest of the ilio-lumbar ligament. From this study we can establish that there are few clinical signs that can help to single out school children with LBP.

Child↗
PubMed1999

Estimating relative survival among people registered with cancer in England and Wales.

Because routinely collected survival data for cancer patients in England and Wales do not typically specify cause of death, conventional estimates of survival in cancer patients based on such data are a measure of their mortality from all causes rather than their mortality due to cancer. As a result, trends in survival over time are difficult to interpret because changes in overall survival may well reflect changes in the risk of death from other causes, rather than from the cancer of interest. One way of overcoming this problem is to use some form of 'relative survival' defined as a measure of survival corrected for the effect of other independent causes of death. Since this concept was first introduced, various methods for calculating relative survival have been proposed and this had led to some confusion as to the most appropriate choice of estimate. This paper aims to provide an introduction to the concept of relative survival and reviews some of the suggested methods of estimation. In addition, a particularly simple, but robust approach, is highlighted based on expected and observed mortality. This method is illustrated using preliminary data from the Office for National Statistics on cancer survival in patients born after 1939 and diagnosed with cancer during 1972-84. The examples presented, although limited to analyses on a small number of selected sites, highlight some encouraging trends in survival in people aged under 35 diagnosed with leukaemia, Hodgkin's disease and testicular cancer during this period.

Cohort Studies↗
PubMed1997

Leukaemia and non-Hodgkin's lymphoma in children and young adults: are prenatal and neonatal factors important determinants of disease?

A medical record-based study of leukaemia and non-Hodgkin's lymphoma diagnosed before the age of 30 years was carried out at three hospitals in the south of England. Findings for 177 cases and 354 age- and sex-matched controls are presented here. For documented viral infection in pregnancy, the odds ratio (OR) was 6.0 [95% confidence interval (CI) 1.2-29.7] for leukaemia and infinity (95% CI 1.24-infinity) for non-Hodgkin's lymphoma. Mothers of leukaemic cases were more likely to be anaemic, the OR for a pregnancy haemoglobin below 10 g being 3.8 (95% CI 1.3-11.1). An association with birthweight was found for acute myeloid leukaemia, the OR for birthweights > 3500 g being 6.2 (95% CI 1.3-29.8). Further, the preceding siblings of those diagnosed with any form of leukaemia were also more likely to weigh > 3500 g at birth (OR 2.2; 95% CI 1.1-4.4). Overall, leukaemic cases appeared to be comparatively robust at birth with respect to other indicators of well-being, the ORs for jaundice, phototherapy, admission to special care nursery and neonatal intensive care all being less than 1.0. Further, no relation between childhood leukaemia and neonatal administration of intramuscular vitamin K was noted (OR 0.6, 95% CI 0.3-1.4; for acute lymphoblastic leukaemia diagnosed between the ages of 1 and 6 years).

Adolescent↗
PubMed1997

The support needs of pregnant and parenting adolescents in rural communities.

Pregnant adolescents and teenage mothers in rural communities face extraordinary difficulties accessing appropriate and adequate support services, despite having recognised specialist health needs and unique support requirements. The Australian Rural Health Research Institute at Charles Sturt University, Wagga Wagga, is currently engaged in a federally funded project aimed it significantly improving access to services for this disadvantaged and often neglected group, through the publication and wide dissemination of a resource booklet identifying successful aspects of service delivery across a range of rural support settings. Five existing health and welfare support services for pregnant or parenting adolescent: in rural Australia have been selected for inclusion in the booklet, which is being developed for community use. Assessment is being undertaken during visits to each of the services, and, following interviews with staff, referral agencies and consumers. This paper outlines the strengths, attributes and access difficulties associated with two contrasting service models involved in the project, and stresses the importance of improving access to services for rural adolescents. A framework for establishing innovative and effective new services is also presented.

Adolescent↗
PubMed1996

A case-control study of cryptorchidism and maternal hormone concentrations in early pregnancy.

Serum samples taken between 6 and 20 weeks of gestation were obtained from 28 mothers who gave birth to cryptorchid sons (cases) and from 108 control mothers. In comparison with controls the cases had 10% higher geometric mean oestradiol (95% CI -13% to +39%: P=0.42) and 10% lower geometric mean testosterone (95% CI -27% to +10%: P=0.30). Among the samples collected between 6 and 14 weeks of gestation geometric mean concentrations of oestradiol and testosterone were 5% lower (95% CI -32% to +31%: P=0.74) and 25% lower (95% CI -45% to +1%: P=0.06) respectively in cases than in controls. Among the samples collected between 15 and 20 weeks of gestation geometric mean concentrations of oestradiol and testosterone were 29% higher (95% CI -8% to +79%: P=0.14) and 21% higher (95% CI -8% to +60%: P=0.18) respectively in cases than in controls. The results do not support the hypothesis that cryptorchidism may be caused by high concentrations of oestradiol in the maternal blood during the first phase of testicular descent, but suggest that the possible association of cryptorchidism with low maternal testosterone during early gestation should be further investigated.

Adult↗
PubMed1996

Cancer in electrical workers: an analysis of cancer registrations in England, 1981-87.

Associations between work in the electrical and electronic industry and cancer incidence were assessed using data for 371 890 cancers registered in England between 1981 and 1987, of which 7981 were in electrical workers. Proportional registration ratios (PRRs) were calculated, both with and without the commonest cancers, with adjustment for age, social class, cancer registry of origin and sex. Of four cancers previously linked with work in the electrical and electronic industry (leukaemia, brain, breast and melanoma), only two were significantly raised: leukaemia (PRR=124, 95% CI=109-142, based on 217 cases) and malignant brain cancer (PRR=118, 95% CI=103-136, based on 204 cases). A significantly increased risk was also observed for pleural cancer (PRR=201, 95% CI=167-241, based on 115 cases). The histology of almost 90% of pleural cancers was coded as mesothelioma, confirming the previously observed association between pleural cancer and exposure to asbestos in electrical workers. The extent to which workplace exposures to extremely low frequency electromagnetic fields explains the excesses seen here for leukaemia and brain cancer requires further study.

Adult↗
PubMed1996

Molecular characterization of berberine bridge enzyme genes from opium poppy.

In Papaver somniferum (opium poppy) and related species, (S)-reticuline serves as a branch-point intermediate in the biosynthesis of numerous isoquinoline alkaloids. The berberine bridge enzyme (BBE) ([S]-reticuline:oxygen oxidoreductase [methylene bridge forming], EC 1.5.3.9) catalyzes the stereospecific conversion of the N-methyl moiety of (S)-reticuline into the berberine bridge carbon of (S)-scoulerine and represents the first committed step in the pathway leading to the antimicrobial alkaloid sanguinarine. Three unique genomic clones (bbe1, bbe2, and bbe3) similar to a BBE cDNA from Eschscholtzia californica (California poppy) were isolated from opium poppy. Two clones (bbe2 and bbe3) contained frame-shift mutations of which bbe2 was identified as a putative, nonexpressed pseudogene by RNA blot hybridization using a gene-specific probe and by the lack of transient expression of a chimeric gene fusion between the bbe2 5' flanking region and a beta-glucuronidase reporter gene. Similarly, bbe1 was shown to be expressed in opium poppy plants and cultured cells. Genomic DNA blot-hybridization data were consistent with a limited number of bbe homologs. RNA blot hybridization showed that bbe genes are expressed in roots and stems of mature plants and in seedlings within 3 d after germination. Rapid and transient BBE mRNA accumulation also occurred after treatment with a fungal elicitor or with methyl jasmonate. However, sanguinarine was found only in roots, seedlings, and fungal elicitor-treated cell cultures.

Amino Acid Sequence↗
PubMed1996

Health of children born to medical radiographers.

OBJECTIVES: To develop a reliable method for collecting information on reproductive outcome in an occupational setting; and to investigate the health of children born to medical radiographers. METHODS: The study population comprised 6730 members of the College of Radiographers who were, at the time of survey; aged between 30 and 64 years, on the current membership file of the College, and were resident in Britain. RESULTS: The postal method developed proved to be reliable, with around 87% of questionnaires being returned. The observed frequencies of reproductive events were broadly in line with findings from other studies: of the 9208 pregnancies reported, 83% were livebirths, 12% were miscarriages (gestational age < 20 weeks), 1% were stillbirths (gestational age > or = 20 weeks), and 1% were other rarer spontaneous adverse events (ectopic pregnancy, blighted ovum, and hydatidiform mole). There was little difference between men and women in the frequency of adverse reproductive events reported, with the exception that male radiographers reported fewer medical terminations, the proportions being 3.1% and 1.4% for women and men respectively. Among children, the overall risks of major congenital malformation (RR 1.0, 95%CI 0.9-1.2), chromosomal anomaly (RR 1.4, 95%CI 0.8-2.3), and cancer (RR 1.2 95%CI 0.7-2.0) were as expected based on general population rates. Borderline excesses of chromosomal anomalies other than Down's syndrome in the children of female radiographers (RR 3.9, 95%CI 1.3-9.0, based on five observations), and cancer in the children of male radiographers (RR 2.7, 95%CI 0.9-6.5, based on five observations) were noted. The numbers on which these risks are based are small and the findings should be interpreted cautiously. CONCLUSIONS: The postal methods developed for obtaining information about reproductive events and child health proved to be reliable in men, as well as in women. Overall, the findings for medical radiographers are reassuring. Dose-response relations could not, however, be examined as long term dose records of radiographers are not routinely kept in an accessible form.

Abnormalities, Radiation-Induced↗
PubMed1994

Cloning and characterisation of the human 5-HT5A serotonin receptor.

The human 5-HT5A serotonin receptor has been cloned. As with the mouse and rat 5-HT5A receptors, the gene consists of two coding exons separated by a large intron. The deduced amino acid sequence of the gene reveals a protein of 357 residues which shares 93% (nucleotide) and 84% (amino acid) identity to the cloned mouse 5-HT5A receptor. We have determined the tissue distribution of the receptor by reverse transcriptase-PCR and found expression in all regions of the brain examined with little or no expression in peripheral tissues. The receptor has been transiently expressed in Cos M6 cells and exhibits a pharmacological profile closely resembling the mouse and rat 5-HT5A receptors with high, specific binding for ergotamine and methiothepin.

Amino Acid Sequence↗
PubMed1994

Turks and Kurds.

Explore the source record for details and available documents.

Ethnicity↗
PubMed1993

Functional abilities at age 4 years of children born before 29 weeks of gestation.

OBJECTIVES: To assess the rate of impairment and disability among babies born very preterm and to investigate the association between such impairment and gestational age at birth. DESIGN: Cohort study of a geographically defined population of babies. SETTING: Oxford Regional Health Authority. SUBJECTS: All babies born alive before 29 weeks of gestation to mothers resident in the region during 1984-6. MAIN OUTCOME MEASURES: Survival rates and rates of impairment and disability among survivors at the age of 4 years. RESULTS: Of the 342 babies, half (170) survived to be discharged home. Of the 164 survivors to age 4 years, 153 (93%) were assessed. A total of 35 (23%; 95% confidence interval 16% to 30%) were severely disabled and only 54 (35%; 28% to 43%) were unimpaired. The risk of impairment and disability increased with decreasing gestational age at birth (p < 0.003). CONCLUSIONS: With the increasing survival rate among babies born before 29 weeks of gestation, we need urgently to establish reliable ways of monitoring the proportion of survivors who have a disability.

Child, Preschool↗
PubMed1993

Case-control study of leukaemia and non-Hodgkin's lymphoma among children aged 0-4 years living in west Berkshire and north Hampshire health districts.

OBJECTIVE: To investigate the relation between parental employment in the nuclear industry and childhood leukaemia and non-Hodgkin's lymphoma. DESIGN: Case-control study. SETTING-West Berkshire and Basingstoke and North Hampshire District Health Authorities. SUBJECTS: 54 children aged 0-4 years who had leukaemia or non-Hodgkin's lymphoma diagnosed during 1972-89, who were born in the study area and were resident there when cancer was diagnosed. Six controls were selected for each case: four from hospital delivery registers and two from livebirth registers maintained by the NHS central register. Controls were matched for sex, date of birth (within six months), and area of residence at birth and time of diagnosis. MAIN OUTCOME MEASURES: Parents' employment by the nuclear industry and exposure to ionising radiation at work. RESULTS: Five (9%) of the 54 cases and 14 (4%) of the 324 controls had fathers or mothers, or both, who had been employed by the nuclear industry (relative risk 2.2, 95% confidence interval 0.6 to 6.9). Nuclear industry employees who work in areas where exposure to radiation is possible are given film badges to monitor their exposure to external penetrating ionising radiation. Three fathers of cases and two fathers of controls (and no mothers of either) had been monitored in this way before their child was conceived (relative risk 9.0, 95% confidence interval 1.0 to 107.8). No father (of a case or control) had accumulated a recorded dose of more than 5 mSv before his child was conceived, and no father had been monitored at any time in the four years before his child was conceived. A dose-response relation was not evident among fathers who had been monitored. CONCLUSIONS: These results suggest that the children of fathers who had been monitored for exposure to external penetrating ionising radiation in the nuclear industry may be at increased risk of developing leukaemia before their fifth birthday. The finding is based on small numbers and could be due to chance. If the relationship is real the mechanisms are far from clear, except that the effect is unlikely to be due to external radiation; the possibility that it could be due to internal contamination by radioactive substances or some other exposure at work should be pursued. The above average rates of leukaemia in the study area cannot be accounted for by these findings.

Case-Control Studies↗