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Biomedical subjects

L Parker

Publications and source records attributed to L Parker.

At least 19 recordsLinked to original sources
PubMed2006

Birth prevalence of cryptorchidism and hypospadias in northern England, 1993-2000.

AIM: There is much debate as to whether the prevalence rates of cryptorchidism and hypospadias are increasing. To address this issue we investigated the birth prevalence of cryptorchidism and hypospadias in the northern region of England during the period 1993-2000. METHODS: Cases of cryptorchidism and hypospadias were identified from northern region hospital episodes statistics (HES). Trends in birth prevalence, based on the number of male live births, were assessed using linear regression. RESULTS: Prevalence was 7.6 per 1000 male live births for cryptorchidism and 3.1 per 1000 male live births for hypospadias. The orchidopexy rates for 0-4 year olds and 5-14 year olds were 1.8 and 0.8 per 1000 male population, respectively. The rates for hypospadias repair for 0-4 year olds and 5-14 year olds were 0.6 and 0.1 per 1000 male population, respectively. There was a statistically significant decreasing temporal trend for the corrective procedure in cryptorchidism of 0.1 per 1000 male population aged under 5 years per annum (95% confidence interval: -0.01 to -0.05, p<0.001), but no temporal change for the corrective procedure in hypospadias (p = 0.60). CONCLUSION: HES data were of high quality for the study period. There was no significant change in the prevalence of surgically corrected hypospadias. However, there was an apparent decline in the prevalence of surgically corrected cryptorchidism that may reflect a decrease in the prevalence of the condition or may be due to a decrease in the rate of surgical intervention.

Adolescent↗
PubMed2006

Childhood IQ and deaths up to middle age: The Newcastle Thousand Families Study.

OBJECTIVES: To test the hypothesis that an association exists between childhood IQ (at age 11) and mortality up to middle age. STUDY DESIGN: The Newcastle Thousand Families study, a prospectively followed cohort, originally consisted of all 1142 births in the city of Newcastle in May and June 1947. Using data on 717 members of this cohort, we investigated the associations between the results of tests of IQ and English and arithmetic ability at age 11 years and mortality up to the end of 2003 using Cox's proportional hazards models. RESULTS: Childhood IQ was significantly related to mortality in men (hazard ratio 0.57 for a standard deviation change in IQ at age 11; 95% CI 0.37, 0.86; P=0.007), but not in women (hazard ratio 0.79; 95% CI 0.49, 1.27; P=0.33). Adjustment for social class at birth had little effect on the associations. Similar results were seen when using the English and arithmetic scores. CONCLUSIONS: These results confirm a recently reported association between individual differences in childhood cognition and mortality up to middle age, independent of childhood socio-economic circumstances. It is possible that the link between IQ and mortality is in part mediated through later life choices. Further research is required to identify the mechanisms by which such an association may occur, and to provide input to health promotion and disease management strategies that may improve health throughout life.

Adolescent↗
PubMed2006

Space-time clustering analyses of type 1 diabetes among 0- to 29-year-olds in Yorkshire, UK.

AIMS/HYPOTHESIS: Infections have been suggested to play a role in the aetiology of type 1 diabetes. The presence of space-time clustering is consistent with the notion of an environmental component in disease aetiology, possibly linked to infections. We tested for evidence of space-time clustering among children and young adults under 30 years of age using data from a population-based register in Yorkshire, UK. SUBJECTS AND METHODS: Two data sets of children and young people diagnosed with type 1 diabetes were analysed: (1) children aged 0-14 years and resident in Yorkshire during 1978-2002; (2) those aged 15-29 years and resident in West Yorkshire during 1991-2002. Tests for space-time interactions between cases were applied. Addresses at diagnosis were geo-coded and used as the basis for the analyses. RESULTS: The study analysed 3,019 type 1 diabetic patients in the 0-14 years age group and 989 patients in the 15-29 years group. Statistically significant space-time clustering based on place and time of diagnosis was detected both for the 10-14-year-olds (p=0.04) and for the 15-19-year-olds (p=0.01). CONCLUSIONS/INTERPRETATION: Previous studies of clustering of type 1 diabetes have generally been restricted to childhood. Our results from a data set that includes teenagers and young adults show that space-time clustering was limited to young people aged 10-19 years. This finding is consistent with an aetiology involving late exposure to infection. However, the question of whether this is directly diabetogenic or unmasks latent diabetes cannot be addressed by this methodology.

Adolescent↗
PubMed2006

Space-time clustering analyses of testicular cancer amongst 15-24-year-olds in Northern England.

There has been speculation that environmental exposures may be involved in the aetiology of testicular cancer in adolescent boys and young men. Indirect evidence for this hypothesis would be provided by the finding of space-time clustering. To examine this we have looked for evidence of space-time clustering using data from a population-based cancer registry from Northern England. All cases of testicular cancer diagnosed in males aged 15-24 years during the period 1968-2002 were included in the study. Tests for space-time interactions between cases were applied with fixed thresholds of close in space and close in time. Addresses at birth and diagnosis were used in the analyses. To adjust for the effect of varying population density tests were repeated replacing fixed geographical distances with nearest neighbour thresholds. A total of 257 cases of testicular cancer were identified for analysis. Overall there was no evidence for space-time clustering. However, there was statistically significant space-time clustering for 15-19-year-old based on time of birth and place of diagnosis (p<0.001). The very limited finding of space-time clustering may provide tentative evidence for an environmental, or infectious component to aetiology. However, it may well be a chance finding. A larger study based on national data is required.

Adolescent↗
PubMed2006

How do factors at different stages of the lifecourse contribute to oral-health-related quality of life in middle age for men and women?

The relative contributions of factors operating in fetal life, childhood, and adulthood to the risk of disease in middle age have become important research issues, but self-perceived oral health has rarely been considered in this context. This study investigated the impact of risk factors operating throughout life on self-perceived oral health, according to the Oral Health Impact Profile (OHIP), at age 50 yrs in 305 individuals from the Newcastle Thousand Families cohort. Factors from early and adult life contributed to the OHIP scores, but in men, self-perceived oral health was mostly explained by factors operating early in life. In women, the number of teeth retained in adulthood had a more prominent impact. Lifecourse influences on oral-health-related quality of life appear different for men and women, which may have implications for the effectiveness of public health interventions and health promotion.

England↗
PubMed2006

Obstructive sleep apnoea syndrome in morbidly obese children with tibia vara.

Morbid obesity and its association with obstructive sleep apnoea syndrome have been increasingly recognised in children. Orthopaedic surgeons are often the primary medical contact for older children with tibia vara, which has long been associated with obesity, but are unfamiliar with the evaluation and treatment of sleep apnoea in children. We reviewed all children with tibia vara treated surgically at one of our institutions over a period of five years. Thirty-seven patients were identified; 18 were nine years of age or older and 13 of these (72%) had morbid obesity and a history of snoring. Eleven children were diagnosed as having sleep apnoea on polysomnography. The incidence of this syndrome in the 18 children aged nine years or older with tibia vara, was 61%. All these patients required pre-operative non-invasive positive-pressure ventilation; tonsillectomy and adenoidectomy were necessary in five (45%). No peri-operative complications related to the airway occurred. There is a high incidence of sleep apnoea in morbidly obese patients with tibia vara. These patients should be screened for snoring and, if present, should be further evaluated for sleep apnoea before corrective surgery is undertaken.

Adenoidectomy↗
PubMed2005

Lifecourse determinants of fasting and post-challenge glucose at age 50 years: the Newcastle Thousand Families Study.

Suboptimal nutrition in early life is suggested to influence plasma glucose levels in later life. This study aimed to determine and quantify influences on plasma glucose levels at age 50. We studied 169 men and 219 women from the Newcastle Thousand Families cohort who attended for clinical examination, including measurements of fasting and 2 h post oral glucose load) at age 50. A lifecourse approach was used to estimate proportions of variance in plasma glucose levels accounted for by each stage of the lifecourse. Birth weight significantly predicted two-hour glucose levels in men (adjusted p = 0.03). Body composition was a significant predictor of both glucose measures in both genders. Interactions existed between body composition and birth weight on fasting glucose in men and two-hour glucose in women and between gender and birth weight on both outcome measures. Fetal life factors directly explained little variation in either glucose measure (< 2%). Adult lifestyle and body composition directly explained larger proportions of the variances (8-13%) for fasting and two-hour glucose than early life measures. The significant effect of birth weight on two-hour glucose seen in men provides support for the fetal origins hypothesis, although adult factors may be more important. Any effect of birth weight on later plasma glucose levels may be compounded by additional effects of adult body composition.

Birth Weight↗
PubMed2005

Effect of cricoid pressure on the view at laryngoscopy.

The impact of cricoid pressure on laryngoscopy is unknown. We have developed a quantitative method of recording the laryngoscopic view using a rigid, zero-degree endoscope. We found that an image matching the laryngoscopist's view could be obtained by positioning the endoscope along the laryngoscopist's 'line of sight'. Photographing this image allowed us to measure laryngeal exposure. We set out to define the effect of cricoid pressure on laryngoscopy using this method. In 40 patients undergoing elective surgery, laryngoscopy was performed with cricoid pressures of 0-60 N, increasing by increments of 10 N. We photographed the laryngoscopic view at each force and recorded dynamic images as cricoid pressure was released. The change in laryngoscopic view with increasing cricoid pressure fell into one of four broad patterns: little change (11 subjects); gradual deterioration (10 subjects); improvement at low force (< 20 N) followed by deterioration (9 subjects); improvement at high force (> 30 N) (10 subjects). We identified five subjects with a good initial view (anteroposterior length of the rima glottidis > 5 mm) who showed a marked deterioration in laryngoscopic view as cricoid pressure increased; in three of these subjects this progressed to obscure the larynx completely at a force of 30 N, 40 N and 60 N, respectively. We conclude that the effect of cricoid pressure on laryngoscopy is complex. However, in some individuals, a force close to that currently recommended (30 N) may cause a complete loss of the glottic view.

Adult↗
PubMed2005

No consistent association between birthweight and parental risk of diabetes and cardiovascular disease.

INTRODUCTION: The fetal insulin hypothesis proposes that the inverse relationship between birthweight and risk of diabetes and cardiovascular disease is partly as a result of inherited factors which influence the effect of insulin and insulin-like growth factors. It has been proposed that an inverse relationship between birthweight and parental risk of diabetes and cardiovascular disease is evidence in support of this hypothesis. PATIENTS AND METHODS: Data from a prospective birth cohort study, followed up to age 50, was used to assess the relationship between birthweight and reported parental diabetes, hypertension, angina and stroke using logistic regression. RESULTS: Of the 832 cohort members traced at age 50, 574 (69%) returned questionnaires that included questions on parental illness. Complete data was available for 541 (94%) of these on maternal illness and for 531 (92%) on paternal illness. Birthweight, standardized for sex and gestational age and adjusted for social class at birth, was inversely associated with maternal stroke (odds ratio = 0.75, 95% confidence intervals 0.60-0.95). There were no other statistically significant associations between birthweight and risk of parental illness. DISCUSSION: We found little evidence of a consistent inverse relationship between birthweight and parental risk of diabetes or cardiovascular disease. This may be because of the quality of our data--which is limited by the problems of collecting robust data over two generations.

Angina Pectoris↗
PubMed2005

Changing socioeconomic inequality in infant mortality in Cumbria.

AIMS: To investigate infant deaths in Cumbria, 1950-93, in relation to individual and community level socioeconomic status. METHODS: Retrospective birth cohort study of all 283,668 live births and 4889 infant deaths in Cumbria, 1950-93. Community deprivation (Townsend score) and individual social class were used to estimate socioeconomic status. Logistic regression was used to investigate risk of infant death (early neonatal, neonatal, and postneonatal) in relation to social class and Townsend deprivation score, adjusting for year of birth, birth order, multiple births, and stratified by time period, 1950-65, 1966-75, 1976-85, 1986-93. RESULTS: The risk of infant death in all categories was higher in the lower social classes and more deprived communities, although inequality in risk of neonatal death declined after 1975 to such an extent that there was no significant difference in neonatal death rates by socioeconomic status in the most recent time period. By contrast, there was no narrowing in socioeconomic inequality in postneonatal death risk over the study period. Community deprivation was associated with a significant increased risk of postneonatal death after adjusting for individual level socioeconomic status. CONCLUSIONS: Postneonatal deaths remain higher in the most deprived communities and in the more disadvantaged social classes. The social, lifestyle, and environmental determinates of adverse health outcomes for children need to be fully understood, and interventions should be designed and targeted at the more socially deprived sectors of our community.

England↗
PubMed2005

Early discharge and readmission to hospital in the first month of life in the Northern Region of the UK during 1998: a case cohort study.

AIMS: To study the frequency and associations of early postpartum discharge and infant readmission to hospital. METHODS: Infants readmitted to hospital during the first 28 days of life in 1998 in the Northern Region of the UK were studied. RESULTS: A total of 4743 of 11,338 (42%) babies were discharged on or before the first postnatal day. Rates of early discharge varied significantly between hospitals. Infants <2500 g at birth (adjusted odds ratio (AOR) 0.44, 95% CI 0.29 to 0.66), infants 35-37 weeks gestation at birth (AOR 0.65, 95% CI 0.49 to 0.86), and firstborn infants (AOR 0.09, 95% CI 0.08 to 0.10) were less likely to be discharged early. Women from more deprived areas were more likely to be discharged early (AOR 1.37, 95% CI 1.12 to 1.67). A total of 907 of 32,015 (2.8%) babies liveborn in the region were readmitted to hospital during 1998. Readmission rates varied significantly by hospital of birth but not by timing of discharge. Babies <2500 g at birth (AOR 1.95, 95% CI 1.16 to 3.28) and babies born at 35-37 weeks gestation (AOR 1.72, 95% CI 1.15 to 2.57) were more likely to be readmitted. Breast fed babies were less likely to be readmitted (AOR 0.69, 95% CI 0.53 to 0.90). Infants initially discharged early were not more likely to be readmitted. CONCLUSIONS: Early discharge occurred variably in the Northern Region in 1998. It is not associated with readmission to hospital. Breast feeding is associated with lower rates of readmission to hospital.

England↗
PubMed2005

Differences in bone mineral density and geometry in men and women: the Newcastle Thousand Families Study at 50 years old.

In 1947 Sir James Spence initiated the Newcastle Thousand Families study, which recruited all 1142 children born in the city between May and June that year. At the age of 50 years, 832 survivors were traced and invited to attend for measurement of bone mineral density (BMD) by dual energy X-ray absorptiometry (DXA). The aim was to compare BMD measurements of men and women in this cohort, before and after adjustment for skeletal size. The femoral neck shaft angles (NSA) were also measured manually from the DXA scan printouts. A total of 171 men and 218 women agreed to participate. As expected men had greater bone mineral content and bone area at all sites (p<0.0001) and were taller and heavier (p<0.0001) than women. Men also had significantly higher BMD than women at all regions (p<0.0002), except at the femoral neck or lumbar spine. After correction for skeletal size and body weight, men had statistically significantly lower volumetric BMD at all sites. The measurement of NSA had good intra/interobserver errors and precision (coefficient of variations 0.79%, 1.2% and 1.2%). Men had significantly larger NSAs (mean 130 degrees , range 121-138 degrees ) than women (mean 128 degrees , range 119-137 degrees ). We conclude that there are gender differences in BMD, skeletal size and geometry in middle aged men and women, which together with the subsequent rate of bone loss, may influence fracture risk in later life.

Absorptiometry, Photon↗
PubMed2004

Regulation of BMP and activin signaling in Drosophila.

Cytokines of the TGF-beta superfamily act through an evolutionarily conserved signaling pathway to elicit a diverse range of biological responses in vertebrates as well as invertebrates. Drosophila has proved to be a powerful system to unravel the profound complexities underlying the regulation of this superficially simple signaling system for two reasons--the availability of sophisticated genetic tools and the restricted number of core signaling components compared to vertebrates. A BMP signaling pathway in Drosophila that regulates growth, differentiation and morphogenesis of the embryo and the larva has been extensively characterized. This work has provided major insights into how gradients of secreted proteins can be established and maintained in vivo, allowing a single ligand to induce multiple cell fates rather than function as an on-off switch. More recently, an activin signaling pathway has also been delineated that is required for growth and neuronal function during development. This review provides an overview of TGF-beta signaling in Drosophila with emphasis on the extensive modulation of signaling activity both within and outside the cell, that enables ligands to trigger specific and context-dependent effects.

Activins↗
PubMed2004

Hospital accessibility and infant death risk.

This study of all 4889 infant deaths within the cohort of all 287 993 births in Cumbria, northwest England (1950-93), found no evidence of an increased risk of infant death with greater travel time to hospitals.

England↗
PubMed2004

Changing patterns of perinatal death, 1982-2000: a retrospective cohort study.

OBJECTIVE: To describe trends in cause specific stillbirth and neonatal mortality. DESIGN: Retrospective cohort study. SETTING AND PARTICIPANTS: 686,860 births in 1982-2000, to mothers resident in the Northern Region of England. MAIN OUTCOME MEASURES: Cause specific stillbirth and neonatal mortality; rate ratios (RR) and 95% confidence intervals (CI) in 1991-2000 compared with 1982-1990. RESULTS: In singletons, rates of stillbirth and neonatal mortality declined over time (RR stillbirths, 0.81 (95% CI 0.76 to 0.87); RR neonatal mortality, 0.76 (95% CI 0.70 to 0.82)). Death from congenital anomalies declined substantially for both stillbirths (RR 0.52; 95% CI 0.40 to 0.68) and neonatal mortality (RR 0.58; 95% CI 0.51 to 0.67). Mortality due to intrapartum hypoxia also fell, by nearly 50% for stillbirths and 30% for neonatal deaths. There was no reduction in stillbirths due to antepartum hypoxia in babies weighing > or = 2500 g, or in mortality attributed to infection. In multiples, the risk of death was higher (RR stillbirths, 4.13 (95% CI 3.68 to 4.64); RR neonatal death, 7.82 (95% CI 7.13 to 8.58)). Stillbirth rates declined significantly (RR 0.71; 95% CI 0.57 to 0.89) but neonatal mortality did not (RR 0.91; 95% CI 0.77 to 1.08). There was no reduction in neonatal mortality resulting from prematurity, or in mortality from congenital anomalies. CONCLUSIONS: There is considerable overlap in the causes of stillbirth and neonatal mortality. Future progress in reducing perinatal mortality requires better understanding of the aetiology of antepartum stillbirth, of the excess risks of prematurity facing multiple births, particularly in the light of their increasing incidence, and of strategies to prevent perinatal infection.

Adult↗