Biomedical subjects

Jennifer Turner

Publications and source records attributed to Jennifer Turner.

8 recordsLinked to original sources

PubMed2005

Risk of non-Hodgkin lymphoma associated with occupational exposure to solvents, metals, organic dusts and PCBs (Australia).

OBJECTIVE: Several studies have suggested that there is an occupational component to the causation of non-Hodgkin lymphoma (NHL). We aimed to use accurate means to assess occupational exposures to solvents, metals, organic dusts and polychlorinated biphenyls (PCBs) in a case-control study. METHODS: Cases were incident NHLs during 2000 and 2001 in two regions of Australia. Controls were randomly selected from the electoral roll and frequency matched to cases by age, sex and region. A detailed occupational history was taken from each subject. For jobs with likely exposure to the chemicals of interest, additional questions were asked by telephone interview using modified job specific modules. An expert allocated exposures using the information in the job histories and the interviews. Odds ratios were calculated for each exposure adjusting for age, sex, region and ethnic origin. RESULTS: 694 cases and 694 controls (70 and 45 respectively of those potentially eligible) participated. The risk of NHL was increased by about 30 for exposure to any solvent with a dose response relationship, subgroup analysis showed the finding was restricted to solvents other than benzene. Exposure to wood dust also increased the risk of NHL slightly. Exposures to other organic dusts, metals, and PCBs were not strongly related to NHL. CONCLUSIONS: The risk of NHL appears to be increased by exposure to solvents other than benzene and possibly to wood dust.

Adult↗

PubMed2004

Sun exposure may protect against non-Hodgkin lymphoma: a case-control study.

Ultraviolet radiation is a hypothesised risk factor for non-Hodgkin lymphoma (NHL) but no epidemiological study has examined this association using direct measures of sun exposure in individuals. Adults aged 20-74 years living in NSW and ACT, Australia, were the study population. Cases (704 of 829 invited to take part, 85%) were diagnosed January 2000 to August 2001. Controls (694 of 1,136 invited to take part, 61%) were randomly selected from state electoral rolls and frequency-matched to cases by age, sex and state of residence. A self-administered questionnaire and telephone interview measured outdoor hours on working and nonworking days and vacations at 10, 20, 30, 40, 50 and 60 years of age. Logistic regression models of NHL and sun exposure contained the 3 matching variables, ethnicity and sun sensitivity measures as covariates. Contrary to expectations, risk of NHL fell with increasing reported sun exposure hours. Relative to 1.0 for the lowest quarter of total sun exposure hours, the odds ratios (ORs) for successively higher quarters were 0.72 (95% CI 0.53-0.98), 0.66 (0.48-0.91) and 0.65 (0.46-0.91) (p(trend)=0.01). The association of sun exposure on nonworking days with NHL was stronger; OR for highest quarter 0.47 (0.34-0.66) (p(trend)=0.0001). Risk also fell with sun exposure on vacations; OR for highest quarter 0.60 (0.43-0.85) (p(trend)=0.003). These associations appeared strongest in women and in childhood. There was little evident trend in risk with exposure on working day. Our results provide strong statistical evidence for an inverse association between sun exposure and NHL. Increasing evidence that vitamin D may protect against cancer makes UV-mediated synthesis of vitamin D a plausible mechanism whereby sun exposure might protect against NHL.

Adolescent↗

PubMed2004

Pigmentary characteristics, sun sensitivity and non-Hodgkin lymphoma.

We report on pigmentary characteristics, sun sensitivity and some other possible risk factors for non-Hodgkin lymphoma (NHL) in people 20-74 years of age. A statewide case-control study was conducted in New South Wales, Australia, with population-based sampling of cases (n = 704) and controls (n = 694). Risk of NHL was increased in subjects with hazel eyes (OR = 1.48; 95% CI = 1.07-2.04), very fair skin (OR = 1.44; 95% CI = 1.01-2.07) and poor ability to tan (OR = 1.70; 95% CI = 1.06-2.71). Risk with mild facial freckling as a child (OR = 0.77; 95% CI = 0.59-0.99) was reduced relative to that with no or moderate to severe freckling. Smokers were not at increased risk of NHL. A past history of treatment for skin cancer was associated with a slight nonsignificant increase in risk. Previous radiotherapy and chemotherapy were associated with 1.5- to 2-fold increases in risk but with wide confidence intervals. These results provide weak support for the possibility that sun sensitivity or perhaps sun exposure increases risk of NHL.

Adult↗

PubMed2004

Structure of a kinesin microtubule depolymerization machine.

With their ability to depolymerize microtubules (MTs), KinI kinesins are the rogue members of the kinesin family. Here we present the 1.6 A crystal structure of a KinI motor core from Plasmodium falciparum, which is sufficient for depolymerization in vitro. Unlike all published kinesin structures to date, nucleotide is not present, and there are noticeable differences in loop regions L6 and L10 (the plus-end tip), L2 and L8 and in switch II (L11 and helix4); otherwise, the pKinI structure is very similar to previous kinesin structures. KinI-conserved amino acids were mutated to alanine, and studied for their effects on depolymerization and ATP hydrolysis. Notably, mutation of three residues in L2 appears to primarily affect depolymerization, rather than general MT binding or ATP hydrolysis. The results of this study confirm the suspected importance of loop 2 for KinI function, and provide evidence that KinI is specialized to hydrolyze ATP after initiating depolymerization.

Animals↗

PubMed2004

Cardiovascular risk factors and sequelae in hypertensive children identified by referral versus school-based screening.

To determine whether systematic differences exist between hypertensive children referred for evaluation by primary care providers and children identified through community-based screening, cardiovascular risk factors and surrogate markers of hypertensive injury were compared based on subject source (referral versus screening). Children referred to a hypertension clinic for persistently elevated blood pressure were compared with children identified as hypertensive during school screening of 5102 students in Houston public schools. M-mode echocardiography of the left ventricle was performed and subsequently reviewed by 2 independent sonographers blinded to identifying subject information. Subsets of subjects also underwent carotid artery ultrasound for measurement of intimal-medial thickness, overnight urine collections for microalbuminuria, and fasting serum cholesterol, triglycerides, and glucose. Ninety-seven total subjects (54 screening and 43 referral) met inclusion criteria and had technically adequate echocardiography performed. The prevalence of left ventricular hypertrophy (LVH) was 37%. Referral subjects demonstrated significantly greater left ventricular mass index (38.8 versus 34.2 g/m(2.7); P<0.01) and a higher prevalence of LVH (49% versus 28%; P<0.05). Among subjects who underwent carotid ultrasound (n=75), carotid intimal-medial thickness was significantly higher in referral subjects (0.61 versus 0.57, P<0.05). When controlling for BMI z score, which was significantly higher in referral subjects, systematic differences by subject source did not persist. These findings suggest that hypertensive children who are predominantly overweight, independent of the manner in which patients come to medical attention, will manifest evidence of more severe cardiovascular disease assessed by surrogate markers such as left ventricular mass index or carotid artery intimal medial thickness.

Adolescent↗

PubMed2004

Characteristics of hypertensive children identified by primary care referral compared with school-based screening.

OBJECTIVES: To determine whether there are clinical differences between children referred for hypertension evaluation from a primary care practice and children with hypertension detected through school-based screening. Study design Referral patients (n=58) were compared with 44 screening patients with hypertension from school-based screening of 5102 students. All subjects underwent 24-hour ambulatory blood pressure (BP) monitoring. White coat hypertension was defined as 24-hour mean BP <95th percentile and BP load <25%. RESULTS: Referral subjects were more likely to be male and had higher body mass index than screening subjects but did not differ by age or ethnic distribution. Average clinic BP values tended to be higher among referral patients (140/79 vs 135/76 mm Hg, P=.07); however, the hypertension severity was closely matched when clinic BP was indexed to the subject-specific 95th percentile. Ambulatory mean BP, BP indices, and BP loads showed no differences by subject source for 24-hour, wake, or sleep periods. White coat hypertension prevalence did not differ between referral and screening subjects (28% vs 30%, P=.83). CONCLUSION: These findings suggest that hypertensive children identified by subspecialty referral are representative of the overall population of hypertensive children in the community, thereby supporting the generalizability of clinic-based research in pediatric hypertension.

Adolescent↗

PubMed2004

Overweight, ethnicity, and the prevalence of hypertension in school-aged children.

OBJECTIVES: To describe the current prevalence of pediatric hypertension and the relationships between gender, ethnicity, overweight, and blood pressure. METHODS: School-based screening was performed in 5102 children (13.5 +/- 1.7 years) from May through November 2002. Age, gender, ethnicity, weight, and height were ascertained, and body mass index (BMI) was calculated as weight (kg)/height (m2). Overweight was defined as BMI > or =95th percentile. Students with blood pressure >95th percentile on the first screening underwent a second screening 1 to 2 weeks later, and then a third screening if blood pressure was >95th percentile at the second screening. RESULTS: Ethnicity distribution was 44% white, 25% Hispanic, 22% African American, and 7% Asian. Overall, overweight prevalence was 20%, which varied significantly by ethnicity (31% Hispanic, 20% African American, 15% white, and 11% Asian). The prevalence of elevated blood pressure after first, second, and third screenings was 19.4%, 9.5%, and 4.5%, respectively. Elevated blood pressure on first screening was highest among Hispanics (25%) and lowest among Asians (14%). Ethnic differences in the prevalence of hypertension (elevated blood pressure on 3 screenings) were not significant after controlling for overweight. The prevalence of hypertension increased progressively as the BMI percentile increased from < or =5th percentile (2%) to > or =95th percentile (11%). After adjustment for gender, ethnicity, overweight, and age, the relative risk of hypertension was significant for gender (relative risk: 1.50; confidence interval: 1.15, 1.95) and overweight (relative risk: 3.26; confidence interval: 2.50, 4.24). CONCLUSIONS: These results confirm an evolving epidemic of cardiovascular risk in youth, as evidenced by an increase in the prevalence of overweight and hypertension, notably among ethnic minority children.

Adolescent↗

PubMed2002

Galanin in human pituitary adenomas: frequency and clinical significance.

OBJECTIVES: Galanin (GAL) is a neuropeptide widely expressed in the central and peripheral nervous system and in neuroendocrine tissue, including the adenohypophysis where, in humans, it is expressed in corticotrophs and in ACTH-producing adenomas. Previous analyses of human tissue have used antiserum against porcine GAL for detection of GAL immunoreactivity (GAL-IR) and no pathophysiological correlates have been reported. Given significant differences between the sequence of porcine and human GAL peptides, the aim of this study was to use antiserum raised against synthetic human GAL to investigate GAL-IR in non tumorous pituitaries and in pituitary adenomas, and to correlate GAL-IR with the clinical and hormonal characteristics of patients with Cushing's disease. PATIENTS: Six nontumorous pituitaries were obtained from autopsy and 151 pituitary adenomas, comprising 62 functioning (16 corticotroph, 26 somatotroph, 19 lactotroph and one thyrotroph) and 89 nonfunctioning adenomas, were obtained by surgery. RESULTS: All non tumorous pituitary glands showed GAL-IR in corticotrophs, in basophil cells within the neurohypophysis and in nerve fibres of the neurohypophysis. GAL-IR was found in a subset (10 of 16) of patients with ACTH-secreting tumours causing Cushing's syndrome. GAL-IR was rarely expressed in somatotroph adenomas and prolactinomas, but was expressed in approximately one-third of nonfunctioning tumours. GAL-IR was found in almost 90% of nonfunctioning tumours that were positive for ACTH. There were no significant differences in sex ratio, age at presentation or 24-h urinary free cortisol secretion in the subset of patients with Cushing's disease positive (n = 10) or negative (n = 6) for GAL-IR. However, Cushing's patients positive for GAL-IR tended to have smaller tumours and achieved a higher cure rate than those without (100 vs. 50%, P = 0.017). CONCLUSIONS: Galanin is present in normal and tumorous human pituitaries. In addition, GAL colocalizes exclusively in corticotrophs of normal pituitaries and is coexpressed almost exclusively in corticotrophs from functioning and nonfunctioning tumours. The finding that corticotroph adenomas can function irrespective of the presence of GAL suggests that GAL may not play a pathophysiological role in Cushing's disease. However, the better surgical outcome observed in patients with Cushing's disease who had tumours positive for GAL-IR suggests that the expression of GAL confers a less aggressive tumour phenotype.

Adenoma↗