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Find video protocols related to scientific articles indexed in Pubmed.
Folate pathway gene polymorphisms, maternal folic acid use and risk of childhood acute lymphoblastic leukemia.
Cancer Epidemiol. Biomarkers Prev.
PUBLISHED: 11-15-2014
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Background: Several studies suggest that maternal folic acid supplementation before or during pregnancy protects against childhood acute lymphoblastic leukemia (ALL). We investigated associations between ALL risk and folate pathway gene polymorphisms, and their modification by maternal folic acid supplements, in a population-based case-control study (2003-2007). Methods: All Australian pediatric oncology centers provided cases; controls were recruited by national random digit dialing. Data from 392 cases and 535 controls were included. Seven folate pathway gene polymorphisms (MTHFR 677C>T, MTHFR 1298A>C, MTRR 66A>G, MTR 2756 A>G, MTR 5049 C>A, CBS 844 Ins68 and CBS 2199 T>C) were genotyped in children and their parents. Information on pre-pregnancy maternal folic acid supplement use was collected. Odds ratios (ORs) were estimated with unconditional logistic regression adjusted for frequency-matched variables and potential confounders. Case-parent trios were also analyzed. Results: There was some evidence of a reduced risk of ALL among children who had, or whose father had, the MTRR 66GG genotype: ORs 0.60 (95% CI 0.39, 0.91) and 0.64 (95% CI 0.40, 1.03) respectively. The ORs for paternal MTHFR 677CT and TT genotypes were 1.41 (95% CI 1.02, 1.93) and 1.81 (95% CI 1.06, 3.07). ORs varied little by maternal folic acid supplementation. Conclusions: Some folate-pathway gene polymorphisms in the child or a parent may influence ALL risk. While biologically plausible, underlying mechanisms for these associations need further elucidation. Impact: Folate pathway polymorphisms may be related to risk of childhood ALL, but larger studies are needed for conclusive results.
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Maternal supplementation with folic acid and other vitamins and risk of leukemia in offspring: a childhood leukemia international consortium study.
Epidemiology
PUBLISHED: 09-11-2014
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Maternal prenatal supplementation with folic acid and other vitamins has been inconsistently associated with a reduced risk of childhood acute lymphoblastic leukemia (ALL). Little is known regarding the association with acute myeloid leukemia (AML), a rarer subtype.
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Vehicle refuelling, use of domestic wood heaters and the risk of childhood brain tumours: Results from an Australian case-control study.
Pediatr Blood Cancer
PUBLISHED: 07-09-2014
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The aetiology of childhood brain tumours (CBT) is largely unknown. Damage to germ cells after parental exposure to airborne carcinogens, such as volatile organic compounds and polycyclic aromatic hydrocarbons is one plausible pathway. This analysis aimed to investigate whether parental refuelling of vehicles or the use of domestic wood heaters in key time periods relating to the child's birth was associated with an increased risk of CBT.
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Maternal dietary intake of folate and vitamins B6 and B12 during pregnancy and risk of childhood brain tumors.
Nutr Cancer
PUBLISHED: 06-04-2014
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Childhood brain tumors (CBT) are the second most common childhood cancers, yet their etiology is largely unknown. We investigated whether maternal gestational intake of folate and vitamins B6 and B12 was associated with CBT risk in a nationwide case-control study conducted 2005-2010. Case children 0-14 years were recruited from all 10 Australian pediatric oncology centers. Control children were recruited by national random digit dialing, frequency matched to cases on age, sex, and state of residence. Dietary intake was ascertained using food frequency questionnaires and adjusted for total energy intake. Data from 293 case and 726 control mothers were analyzed using unconditional logistic regression. The odds ratio (OR) for the highest versus lowest tertile of folate intake was 0.70 [95% confidence interval (CI): 0.48, 1.02]. The ORs appeared lower in mothers who drank alcohol during pregnancy (OR = 0.45, 95% CI: 0.22, 0.93), mothers who took folic acid (OR = 0.67, 95% CI: 0.42, 1.06) or B6/B12 supplements (OR = 0.51, 95% CI: 0.25, 1.06) and in children younger than 5 years (OR = 0.50, 95% CI: 0.27, 0.93). These findings are consistent with folate's crucial role in maintenance of genomic integrity and DNA methylation. Dietary intake of B6 and B12 was not associated with risk of CBT.
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Oblique orientation discrimination thresholds are superior in those with a high level of autistic traits.
J Autism Dev Disord
PUBLISHED: 05-30-2014
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Enhanced low-level perception, although present in individuals with autism, is not seen in individuals with high, but non-clinical, levels of autistic traits (Brock et al.in Percept Lond 40(6):739. doi: 10.1068/p6953 , 2011). This is surprising, as many of the higher-level visual differences found in autism have been shown to correlate with autistic traits in non-clinical samples. Here we measure vertical-oblique and, more difficult, oblique-oblique orientation discrimination thresholds in a non-clinical sample. As predicted, oblique-oblique thresholds provided a more sensitive test of orientation discrimination, and were negatively related to autistic traits (N = 94, r = -.356, p < .0001). We conclude that individual differences in orientation discrimination and autistic traits are related, and suggest that both of these factors could be mediated by increased levels of the inhibitory neurotransmitter GABA.
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Maternal consumption of coffee and tea during pregnancy and risk of childhood brain tumors: results from an Australian case-control study.
Cancer Causes Control
PUBLISHED: 04-29-2014
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The causes of childhood brain tumors (CBT) are largely unknown, but gestational diet may influence this risk. The aim of this analysis was to investigate whether maternal coffee or tea consumption during pregnancy was associated with the risk of CBT.
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Paternal intake of folate and vitamins B6 and B12 before conception and risk of childhood acute lymphoblastic leukemia.
Cancer Causes Control
PUBLISHED: 04-25-2014
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We investigated whether paternal dietary intake of folate before conception is associated with the risk of childhood acute lymphoblastic leukemia (ALL) in a nationwide case-control study.
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Ultraviolet radiation exposure and serum vitamin D levels in young children.
J Paediatr Child Health
PUBLISHED: 03-12-2014
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Health benefits of adequate vitamin D levels in the blood include better bone health and a reduced incidence of a range of chronic diseases and infections. Ultraviolet (UV) radiation exposure from the sun is the main source of vitamin D; however, such exposure, especially from a young age, is also a potential risk factor for skin cancer. The current study examined the association of UV exposure with vitamin D production in young children to determine the period of weekly exposure prior to blood testing that affected serum 25-hydroxyvitamin D (25(OH)D) levels.
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Parental occupational pesticide exposure and the risk of childhood leukemia in the offspring: findings from the childhood leukemia international consortium.
Int. J. Cancer
PUBLISHED: 02-26-2014
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Maternal occupational pesticide exposure during pregnancy and/or paternal occupational pesticide exposure around conception have been suggested to increase risk of leukemia in the offspring. With a view to providing insight in this area we pooled individual level data from 13 case-control studies participating in the Childhood Leukemia International Consortium (CLIC). Occupational data were harmonized to a compatible format. Pooled individual analyses were undertaken using unconditional logistic regression. Using exposure data from mothers of 8,236 cases, and 14,850 controls, and from fathers of 8,169 cases and 14,201 controls the odds ratio (OR) for maternal exposure during pregnancy and the risk of acute lymphoblastic leukemia (ALL) was 1.01 [95% confidence interval (CI) 0.78, 1.30] and for paternal exposure around conception 1.20 (95% 1.06, 1.38). For acute myeloid leukemia (AML), the OR for maternal exposure during pregnancy was 1.94 (CI 1.19, 3.18) and for paternal exposure around conception 0.91 (CI 0.66, 1.24.) based on data from 1,329 case and 12,141 control mothers, and 1,231 case and 11,383 control fathers. Our finding of a significantly increased risk of AML in the offspring with maternal exposure to pesticides during pregnancy is consistent with previous reports. We also found a slight increase in risk of ALL with paternal exposure around conception which appeared to be more evident in children diagnosed at the age of 5 years or more and those with T cell ALL which raises interesting questions on possible mechanisms.
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Childhood and parental diagnostic radiological procedures and risk of childhood brain tumors.
Cancer Causes Control
PUBLISHED: 01-08-2014
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Childhood brain tumors (CBT) are the second most common type of childhood cancer and the leading cause of childhood cancer mortality. Few causes of CBT are known, but parental, fetal, and early life exposures are likely to be important given the early age at diagnosis of many cases. We aimed to investigate whether parents' diagnostic radiological procedures before conception, in the mother during pregnancy or the child's procedures were associated with an increased risk of CBT.
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Confirmation of Childhood Acute Lymphoblastic Leukemia Variants, ARID5B and IKZF1, and Interaction with Parental Environmental Exposures.
PLoS ONE
PUBLISHED: 01-01-2014
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Genome wide association studies (GWAS) have established association of ARID5B and IKZF1 variants with childhood acute lymphoblastic leukemia (ALL). Epidemiological studies suggest that environmental factors alone appear to make a relatively minor contribution to disease risk. The polygenic nature of childhood ALL predisposition together with the timing of environmental triggers may hold vital clues for disease etiology. This study presents results from an Australian GWAS of childhood ALL cases (n?=?358) and population controls (n?=?1192). Furthermore, we utilised family trio (n?=?204) genotypes to extend our investigation to gene-environment interaction of significant loci with parental exposures before conception, and child's sex and age. Thirteen SNPs achieved genome wide significance in the population based case/control analysis; ten annotated to ARID5B and three to IKZF1. The most significant SNPs in these regions were ARID5B rs4245595 (OR 1.63, CI 1.38-1.93, P?=?2.13×10-9), and IKZF1 rs1110701 (OR 1.69, CI 1.42-2.02, p?=?7.26×10-9). There was evidence of gene-environment interaction for risk genotype at IKZF1, whereby an apparently stronger genetic effect was observed if the mother took folic acid or if the father did not smoke prior to pregnancy (respective interaction P-values: 0.04, 0.05). There were no interactions of risk genotypes with age or sex (P-values >0.2). Our results evidence that interaction of genetic variants and environmental exposures may further alter risk of childhood ALL however, investigation in a larger population is required. If interaction of folic acid supplementation and IKZF1 variants holds, it may be useful to quantify folate levels prior to initiating use of folic acid supplements.
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The MOBI-Kids Study Protocol: Challenges in Assessing Childhood and Adolescent Exposure to Electromagnetic Fields from Wireless Telecommunication Technologies and Possible Association with Brain Tumor Risk.
Front Public Health
PUBLISHED: 01-01-2014
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The rapid increase in mobile phone use in young people has generated concern about possible health effects of exposure to radiofrequency (RF) and extremely low frequency (ELF) electromagnetic fields (EMF). MOBI-Kids, a multinational case-control study, investigates the potential effects of childhood and adolescent exposure to EMF from mobile communications technologies on brain tumor risk in 14 countries. The study, which aims to include approximately 1,000 brain tumor cases aged 10-24?years and two individually matched controls for each case, follows a common protocol and builds upon the methodological experience of the INTERPHONE study. The design and conduct of a study on EMF exposure and brain tumor risk in young people in a large number of countries is complex and poses methodological challenges. This manuscript discusses the design of MOBI-Kids and describes the challenges and approaches chosen to address them, including: (1) the choice of controls operated for suspected appendicitis, to reduce potential selection bias related to low response rates among population controls; (2) investigating a young study population spanning a relatively wide age range; (3) conducting a large, multinational epidemiological study, while adhering to increasingly stricter ethics requirements; (4) investigating a rare and potentially fatal disease; and (5) assessing exposure to EMF from communication technologies. Our experience in thus far developing and implementing the study protocol indicates that MOBI-Kids is feasible and will generate results that will contribute to the understanding of potential brain tumor risks associated with use of mobile phones and other wireless communications technologies among young people.
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Rule-based exposure assessment versus case-by-case expert assessment using the same information in a community-based study.
Occup Environ Med
PUBLISHED: 11-12-2013
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Retrospective exposure assessment in community-based studies is largely reliant on questionnaire information. Expert assessment is often used to assess lifetime occupational exposures, but these assessments generally lack transparency and are very time-consuming. We explored the agreement between a rule-based assessment approach and case-by-case expert assessment of occupational exposures in a community-based study.
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Factors relating to pregnancy and birth and the risk of childhood brain tumors: Results from an Australian case-control study.
Pediatr Blood Cancer
PUBLISHED: 07-25-2013
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Childhood brain tumors (CBT) are the leading cause of cancer death in children, yet their causes are largely known. This study investigated the association between maternal and birth characteristics and risk of CBT.
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Exposure to household painting and floor treatments, and parental occupational paint exposure and risk of childhood brain tumors: results from an Australian case-control study.
Cancer Causes Control
PUBLISHED: 07-15-2013
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Childhood brain tumors (CBT) are the leading cause of cancer death in children, yet their etiology remains largely unknown. This study investigated whether household exposure to paints and floor treatments and parental occupational painting were associated with CBT risk in a population-based case-control study conducted between 2005 and 2010.
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Brief report: Preliminary evidence of reduced sensitivity in the peripheral visual field of adolescents with autistic spectrum disorder.
J Autism Dev Disord
PUBLISHED: 05-08-2013
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A number of studies have demonstrated atypical perception in individuals with ASD. However, the majority of these studies have presented stimuli to central vision. The aim of the study presented here was to test the sensitivity of peripheral vision in ASD. This was achieved by asking participants to detect brief flashes of light presented between 30 and 85 degrees away from fixation. We found that participants with ASD detected fewer ligh-flashes than the control participants. This deficit was more pronounced in the nasal hemifield than the temporal hemifield. We suggest that the imbalance between nasal and temporal hemifield sensitivity may contribute to the peripheral-field stimulation and lateral glances that are observed in ASD.
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Participation in paediatric cancer studies: timing and approach to recruitment.
BMC Res Notes
PUBLISHED: 05-06-2013
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Participation in epidemiological studies has fallen significantly over the past 30 years; this has been attributed to a busier lifestyle and longer working hours. In case-control studies, participation among cases is usually higher than among controls due to the personal relevance. In Australia, between 2003 and 2011, we conducted three national population-based case-control studies of risk factors for childhood cancers; brain tumors, acute leukemia and neuroblastoma and Wilms tumor. In this sub-study, we aimed to investigate factors that may have influenced study participation and completeness of survey completion.
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Familial aggregation of childhood and adult cancer in the Utah genealogy.
Int. J. Cancer
PUBLISHED: 04-29-2013
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A small proportion of childhood cancer is attributable to known hereditary syndromes, but whether there is any familial component to the remainder remains uncertain. We explored familial aggregation of cancer in a population-based case-control study using genealogical record linkage and designed to overcome limitations of previous studies. Subjects were selected from the Utah Population Database. We compared risk of cancer in adult first-degree relatives of children who were diagnosed with cancer with the risk in relatives of children who had not had a cancer diagnosed. We identified 1,894 childhood cancer cases and 3,788 controls; 7,467 relatives of cases and 14,498 relatives of controls were included in the analysis. Relatives of children with cancer had a higher risk of cancer in adulthood than relatives of children without cancer [odds ratio (OR) 1.31, 95% confidence interval (CI) 1.11-1.56]; this was restricted to mothers and siblings and was not evident in fathers. Familial aggregation appeared stronger among relatives of cases diagnosed before 5 years of age (OR 1.48, 95% CI 1.13-1.95) than among relatives of cases who were older when diagnosed (OR 1.22, 95% CI 0.98-1.51). These findings provide evidence of a generalized excess of cancer in the mothers and siblings of children with cancer. The tendency for risk to be higher in the relatives of children who were younger at cancer diagnosis should be investigated in other large data sets. The excesses of thyroid cancer in parents of children with cancer and of any cancer in relatives of children with leukemia merit further investigation.
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A cross-cultural comparison of autistic traits in the UK, India and Malaysia.
J Autism Dev Disord
PUBLISHED: 03-16-2013
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The disorder of autism is widely recognised throughout the world. However, the diagnostic criteria and theories of autism are based on research predominantly conducted in Western cultures. Here we compare the expression of autistic traits in a sample of neurotypical individuals from one Western culture (UK) and two Eastern cultures (India and Malaysia), using the Autism-spectrum Quotient (AQ) in order to identify possible cultural differences in the expression of autistic traits. Behaviours associated with autistic traits were reported to a greater extent in the Eastern cultures than the Western culture. Males scored higher than females and science students scored higher than non-science students in each culture. Indian students scored higher than both other groups on the Imagination sub-scale, Malaysian students scored higher than both other groups on the Attention Switching sub-scale. The underlying factor structures of the AQ for each population were derived and discussed.
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Assisted reproductive technology and birth defects: a systematic review and meta-analysis.
Hum. Reprod. Update
PUBLISHED: 02-28-2013
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It has been 10 years since we carried out a systematic search of the literature on birth defect risk in infants born following assisted reproductive technology (ART) compared with non-ART infants. Because of changes to ART practice since that review and the publication of more studies the objective of this review was to include these more recent studies to estimate birth defect risk after ART and to examine birth defect risk separately in ART singletons and multiples.
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Parental smoking and risk of childhood brain tumors.
Int. J. Cancer
PUBLISHED: 02-13-2013
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Childhood brain tumors (CBT) are the leading cause of cancer death in children, yet their etiology remains largely unknown. Tobacco smoke contains 61 known carcinogens and increases the risk of several adult cancers. This study investigated associations between parental smoking and risk of CBT in a population-based case-control study conducted between 2005 and 2010. Cases were identified through all ten Australian pediatric oncology centers, controls via nationwide random-digit dialing, frequency matched to cases on age, sex and state of residence. Parental smoking information was obtained for 302 cases and 941 controls through mailed questionnaires that requested average daily cigarette use in each calendar year from age 15 to the childs birth, linked to residential and occupational histories. Data were analyzed using unconditional logistic regression, adjusting for frequency matching variables and potential confounders. Overall, parental smoking before or during pregnancy showed no association with CBT risk. The odds ratios for maternal smoking before and during pregnancy were 0.99 (95% CI: 0.70, 1.40) and 0.89 (95% CI: 0.61, 1.21), respectively, and those for paternal smoking before and during pregnancy were 0.99 (95% CI: 0.71, 1.38) and 1.04 (95% CI: 0.74, 1.46), respectively. In children under 24 months of age, the odds ratios for maternal smoking preconception and during pregnancy were 5.06 (95% CI 1.35-19.00) and 4.61 (95% CI: 1.08, 19.63), although these results were based on modest numbers. Future studies should investigate the associations between maternal smoking and risk of CBT by the childs age of diagnosis.
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The Childhood Leukemia International Consortium.
Cancer Epidemiol
PUBLISHED: 02-09-2013
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Acute leukemia is the most common cancer in children under 15 years of age; 80% are acute lymphoblastic leukemia (ALL) and 17% are acute myeloid leukemia (AML). Childhood leukemia shows further diversity based on cytogenetic and molecular characteristics, which may relate to distinct etiologies. Case-control studies conducted worldwide, particularly of ALL, have collected a wealth of data on potential risk factors and in some studies, biospecimens. There is growing evidence for the role of infectious/immunologic factors, fetal growth, and several environmental factors in the etiology of childhood ALL. The risk of childhood leukemia, like other complex diseases, is likely to be influenced both by independent and interactive effects of genes and environmental exposures. While some studies have analyzed the role of genetic variants, few have been sufficiently powered to investigate gene-environment interactions.
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Fetal growth and childhood acute lymphoblastic leukemia: findings from the childhood leukemia international consortium.
Int. J. Cancer
PUBLISHED: 01-29-2013
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Positive associations have been reported between the measures of accelerated fetal growth and risk of childhood acute lymphoblastic leukemia (ALL). We investigated this association by pooling individual-level data from 12 case-control studies participating in the Childhood Leukemia International Consortium. Two measures of fetal growth-weight-for-gestational-age and proportion of optimal birth weight (POBW)-were analysed. Study-specific odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using multivariable logistic regression, and combined in fixed effects meta-analyses. Pooled analyses of all data were also undertaken using multivariable logistic regression. Subgroup analyses were undertaken when possible. Data on weight for gestational age were available for 7,348 cases and 12,489 controls from all 12 studies and POBW data were available for 1,680 cases and 3,139 controls from three studies. The summary ORs from the meta-analyses were 1.24 (95% CI: 1.13, 1.36) for children who were large for gestational age relative to appropriate for gestational age, and 1.16 (95% CI: 1.09, 1.24) for a one-standard deviation increase in POBW. The pooled analyses produced similar results. The summary and pooled ORs for small-for-gestational-age children were 0.83 (95% CI: 0.75, 0.92) and 0.86 (95% CI: 0.77, 0.95), respectively. Results were consistent across subgroups defined by sex, ethnicity and immunophenotype, and when the analysis was restricted to children who did not have high birth weight. The evidence that accelerated fetal growth is associated with a modest increased risk of childhood ALL is strong and consistent with known biological mechanisms involving insulin-like growth factors. © 2013 UICC.
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Visual search performance is predicted by the degree to which selective attention to features modulates the ERP between 350 and 600ms.
Neuropsychologia
PUBLISHED: 01-17-2013
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Efficient visual search necessitates perception of items in the visual array, rapid classification of items as either targets or distractors, and the selection of target items. Individuals vary in the speed with which they perform these operations and can detect targets within cluttered arrays, as shown in visual search tasks. Individuals with autism spectrum disorders (ASD) show particular strengths in visual search. The aim of the current study was to develop an understanding the origin of individual variability in visual search by delineating the processes involved in feature-based target detection, and establishing which, if any, of these processes predict search efficiency. EEG was recorded while participants performed a feature-based selective attention task from which the following EEG variables were computed: P1 amplitude; P1 latency; selection negativity; induced ?-band power and P3b amplitude. These variables are considered to reflect stimulus encoding, feedback amplification of attended features, cognitive utilization and resource allocation during event classification respectively. Participants also completed a separate visual search task. Regression analyses revealed that only the ERP component associated with resource allocation during event classification (P3b) significantly predicted search efficiency. These data suggest that individual variability in visual search is related to a reduction in modulation of attention allocation to visual features. Implications for the understanding of superior visual search in individuals with ASD are discussed.
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Exposure to pesticides and the risk of childhood brain tumors.
Cancer Causes Control
PUBLISHED: 01-16-2013
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Previous research has suggested positive associations between parental or childhood exposure to pesticides and risk of childhood brain tumors (CBT). This Australian case-control study of CBT investigated whether exposures to pesticides before pregnancy, during pregnancy and during childhood, were associated with an increased risk.
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Parental prenatal smoking and risk of childhood acute lymphoblastic leukemia.
Am. J. Epidemiol.
PUBLISHED: 12-05-2011
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The association between parental smoking and risk of childhood acute lymphoblastic leukemia (ALL) was investigated in an Australian population-based case-control study that included 388 cases and 868 controls aged <15 years, recruited from 2003 to 2006. Both of the childs parents provided information about their smoking habits for each year from age 15 years to the childs birth. Data were analyzed by logistic regression. Maternal smoking was not associated with risk of childhood ALL, but the odds ratio for paternal smoking of ?15 cigarettes per day around the time of the childs conception was 1.35 (95% confidence interval: 0.98, 1.86). The associations between parental smoking risk of childhood ALL did not differ substantially by immunophenotypic or cytogenetic subtype. Meta-analyses of paternal smoking, including results from the Australian Study of Causes of Acute Lymphoblastic Leukemia in Children and those of previous studies, produced summary odds ratios of 1.15 (95% confidence interval: 1.06, 1.24) for any paternal smoking around the time of the childs conception and 1.44 (95% confidence interval: 1.24, 1.68) for smoking ?20 cigarettes per day at that time. Study results suggest that heavier paternal smoking around the time of conception is a risk factor for childhood ALL. Men should be strongly encouraged to cease smoking, particularly when planning to start a family.
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Refuelling of vehicles, the use of wood burners and the risk of acute lymphoblastic leukaemia in childhood.
Paediatr Perinat Epidemiol
PUBLISHED: 08-16-2011
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It is plausible that exposure of the parents before birth or of the child to sources of benzene increases the risk of childhood acute lymphoblastic leukaemia (ALL). The aim of this analysis was to investigate whether refuelling a vehicle with petrol before birth or burning wood to heat the home before or after the childs birth increased the risk of childhood ALL. Data from 389 cases and 876 frequency-matched controls were analysed using unconditional logistic regression, adjusting for study matching factors and potential confounders. The odds ratio (OR) for the mother ever refuelling a vehicle with petrol for non-occupational purposes before or during the pregnancy was 0.97 [95% confidence interval (CI) 0.69, 1.38]. The OR for the father for this exposure in the year before conception was 0.88 [95% CI 0.52, 1.48]. The OR for use of a closed wood burner to heat the home in the year before or during pregnancy was 1.41 [95% CI 1.02, 1.94] and 1.25 [95% CI 0.92, 1.70] after birth. We found no evidence that non-occupational refuelling a vehicle with petrol in the year before or during pregnancy increased the risk of ALL in the offspring. There was weak evidence that burning wood in a closed burner to heat the home increased the risk, but there was no dose-response relationship and chance could explain the finding.
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Parental occupational exposure to exhausts, solvents, glues and paints, and risk of childhood leukemia.
Cancer Causes Control
PUBLISHED: 03-25-2011
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It is unknown whether parental occupational exposure to chemicals before during and after pregnancy increases the risk of acute lymphoblastic leukemia (ALL) in the offspring. Few studies on this topic have assessed maternal exposures.
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Increased intra-participant variability in children with autistic spectrum disorders: evidence from single-trial analysis of evoked EEG.
Front Psychol
PUBLISHED: 03-19-2011
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Intra-participant variability in clinical conditions such as autistic spectrum disorder (ASD) is an important indicator of pathophysiological processing. The data reported here illustrate that trial-by-trial variability can be reliably measured from EEG, and that intra-participant EEG variability is significantly greater in those with ASD than in neuro-typical matched controls. EEG recorded at the scalp is a linear mixture of activity arising from muscle artifacts and numerous concurrent brain processes. To minimize these additional sources of variability, EEG data were subjected to two different methods of spatial filtering. (i) The data were decomposed using infomax independent component analysis, a method of blind source separation which un-mixes the EEG signal into components with maximally independent time-courses, and (ii) a surface Laplacian transform was performed (current source density interpolation) in order to reduce the effects of volume conduction. Data are presented from 13 high functioning adolescents with ASD without co-morbid ADHD, and 12 neuro-typical age-, IQ-, and gender-matched controls. Comparison of variability between the ASD and neuro-typical groups indicated that intra-participant variability of P1 latency and P1 amplitude was greater in the participants with ASD, and inter-trial ?-band phase coherence was lower in the participants with ASD. These data support the suggestion that individuals with ASD are less able to synchronize the activity of stimulus-related cell assemblies than neuro-typical individuals, and provide empirical evidence in support of theories of increased neural noise in ASD.
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Exposure to professional pest control treatments and the risk of childhood acute lymphoblastic leukemia.
Int. J. Cancer
PUBLISHED: 02-11-2011
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Previous studies suggest that exposure to pesticides increases the risk of childhood acute lymphoblastic leukemia (ALL). The aim of this analysis was to investigate whether professional pest treatments in or around the home before birth or during childhood increased the risk of childhood ALL. Data from 388 cases and 870 frequency-matched controls were analyzed using unconditional logistic regression, adjusting for study matching variables and potential confounders, to calculate odds ratios (ORs). A meta-analysis of our findings with the published findings of previous studies was also conducted. The ORs for any professional pest control treatments were 1.19 (95% CI 0.83, 1.69) in the year before pregnancy, 1.30 (95% CI 0.86, 1.97) during pregnancy and 1.24 (95% CI 0.93, 1.65) for those done after the childs birth. The ORs for exposure after birth were highest when it occurred between the ages of two and three years. ORs were elevated for termite treatments before birth. ORs were higher for pre-B than T cell ALL and for t(12;21) (ETV6-Runx-1) than other cytogenetic sub-types. The pooled OR from a meta-analysis of our study with three previous studies of professional pest control treatments during pregnancy was 1.37 (95% CI 1.00, 1.88). Our results, and those of our meta-analysis, provide some evidence of a modestly increased risk of ALL for professional pest control treatments done during the index pregnancy and possibly in the childs early years. The analysis of pooled data from international collaborations may provide more certainty regarding these potentially important associations.
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Western Australian children with acute lymphoblastic leukemia are taller at diagnosis than unaffected children of the same age and sex.
Pediatr Blood Cancer
PUBLISHED: 01-18-2011
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Acute lymphoblastic leukemia (ALL) is the commonest childhood malignancy in Australian children. Recently published data from Western Australia suggest a link between proportion of optimal birth weight and the risk of ALL, but few studies have investigated the relationship between growth during infancy and early childhood and risk of leukemia. The aim of this study was to determine whether children diagnosed with ALL in Western Australia were taller at the time of diagnosis than children of the same age and sex in the general population.
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Development of motion processing in children with autism.
Dev Sci
PUBLISHED: 10-28-2010
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Recent findings suggest that children with autism may be impaired in the perception of biological motion from moving point-light displays. Some children with autism also have abnormally high motion coherence thresholds. In the current study we tested a group of children with autism and a group of typically developing children aged 5 to 12 years of age on several motion perception tasks, in order to establish the specificity of the biological motion deficit in relation to other visual discrimination skills. The first task required the recognition of biological from scrambled motion. Three quasi-psychophysical tasks then established individual thresholds for the detection of biological motion in dynamic noise, of motion coherence and of form-from-motion. Lastly, individual thresholds for a task of static perception--contour integration (Gabor displays)--were also obtained. Compared to controls, children with autism were particularly impaired in processing biological motion in relation to any developmental measure (chronological or mental age). In contrast, there was some developmental overlap in ability to process other types of visual motion between typically developing children and the children with autism, and evidence of developmental change in both groups. Finally, Gabor display thresholds appeared to develop typically in children with autism.
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Exposure to diagnostic radiological procedures and the risk of childhood acute lymphoblastic leukemia.
Cancer Epidemiol. Biomarkers Prev.
PUBLISHED: 09-22-2010
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Diagnostic irradiation of the mother during pregnancy increases the risk of childhood acute lymphoblastic leukemia (ALL). There is inconsistent evidence on associations between ALL and other parental or childhood diagnostic irradiation. The aim of this analysis is to investigate whether diagnostic X-rays of the mother before birth, of the father before conception, or of the child increased the risk of childhood ALL.
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Maternal consumption of coffee and tea during pregnancy and risk of childhood ALL: results from an Australian case-control study.
Cancer Causes Control
PUBLISHED: 06-29-2010
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To investigate whether maternal coffee and/or tea consumption during the last 6 months of pregnancy was associated with risk of childhood ALL.
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Representativeness of child controls recruited by random digit dialling.
Paediatr Perinat Epidemiol
PUBLISHED: 04-27-2010
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Recruiting control subjects who are representative of the population from which the cases are drawn is a challenge in case-control studies. This paper examines the performance of random digit dialling (RDD) in obtaining a control sample, and the samples representativeness of the population with respect to socio-economic status. The study subjects were recruited from 2003 to 2006 for a national, population-based case-control study investigating causes of acute lymphoblastic leukaemia (ALL) in children <15 years of age in Australia. Control families addresses were linked to Australian Bureau of Statistics Census 2006 Collection Districts and thus to Socio-Economic Indexes for Area scores, which are area-based measures of socio-economic status. These scores were compared with those of all collection districts where families lived. We estimate that 55% of eligible families in the RDD sample agreed to participate in the study. Participation was directly related to socio-economic status with those of highest economic status most likely to participate. Completeness of participation in the components of data collection was similarly related to socio-economic status. This evidence of selection according to socio-economic status indicates that there may also be selection with respect to other factors potentially important in the aetiology of ALL.
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A comparison of the development of audiovisual integration in children with autism spectrum disorders and typically developing children.
J Autism Dev Disord
PUBLISHED: 04-01-2010
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This study aimed to investigate the development of audiovisual integration in children with Autism Spectrum Disorder (ASD). Audiovisual integration was measured using the McGurk effect in children with ASD aged 7-16 years and typically developing children (control group) matched approximately for age, sex, nonverbal ability and verbal ability. Results showed that the children with ASD were delayed in visual accuracy and audiovisual integration compared to the control group. However, in the audiovisual integration measure, children with ASD appeared to catch-up with their typically developing peers at the older age ranges. The suggestion that children with ASD show a deficit in audiovisual integration which diminishes with age has clinical implications for those assessing and treating these children.
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Spatial contrast sensitivity in adolescents with autism spectrum disorders.
J Autism Dev Disord
PUBLISHED: 03-10-2010
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Adolescents with autism spectrum disorders (ASD) and typically developing (TD) controls underwent a rigorous psychophysical assessment that measured contrast sensitivity to seven spatial frequencies (0.5-20 cycles/degree). A contrast sensitivity function (CSF) was then fitted for each participant, from which four measures were obtained: visual acuity, peak spatial frequency, peak contrast sensitivity, and contrast sensitivity at a low spatial frequency. There were no group differences on any of the four CSF measures, indicating no differential spatial frequency processing in ASD. Although it has been suggested that detail-oriented visual perception in individuals with ASD may be a result of differential sensitivities to low versus high spatial frequencies, the current study finds no evidence to support this hypothesis.
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Contrast sensitivity for motion detection and direction discrimination in adolescents with autism spectrum disorders and their siblings.
Neuropsychologia
PUBLISHED: 03-08-2010
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The magnocellular (M) pathway hypothesis proposes that impaired visual motion perception observed in individuals with Autism Spectrum Disorders (ASD) might be mediated by atypical functioning of the subcortical M pathway, as this pathway provides the bulk of visual input to cortical motion detectors. To test this hypothesis, we measured luminance and chromatic contrast sensitivity, thought to tap M and Parvocellular (P) pathway processing, respectively. We also tested the hypothesis that motion processing is impaired in ASD using a novel paradigm that measures motion processing while controlling for detectabilty. Specifically, this paradigm compares contrast sensitivity for detection of a moving grating with contrast sensitivity for direction-of-motion discrimination of that same moving grating. Contrast sensitivities from adolescents with ASD were compared to typically-developing adolescents, and also unaffected siblings of individuals with ASD (SIBS). The results revealed significant group differences on P, but not M, pathway processing, with SIBS showing higher chromatic contrast sensitivity than both participants with ASD and TD participants. This atypicality, unique to SIBS, suggests the possible existence of a protective factor in these individuals against developing ASD. The results also revealed impairments in motion perception in both participants with ASD and SIBS, which may be an endophenotype of ASD. This impairment may be driven by impairments in motion detectors and/or by reduced input from neural areas that project to motion detectors, the latter possibility being consistent with the notion of reduced connectivity between neural areas in ASD.
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Detecting genotyping error using measures of degree of Hardy-Weinberg disequilibrium.
Stat Appl Genet Mol Biol
PUBLISHED: 01-06-2010
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Tests for Hardy-Weinberg equilibrium (HWE) have been used to detect genotyping error, but those tests have low power unless the sample size is very large. We assessed the performance of measures of departure from HWE as an alternative way of screening for genotyping error. Three measures of the degree of disequilibrium (alpha, ,D, and F) were tested for their ability to detect genotyping error of 5% or more using simulations and a real dataset of 184 children with leukemia genotyped at 28 single nucleotide polymorphisms. The simulations indicate that all three disequilibrium coefficients can usefully detect genotyping error as judged by the area under the Receiver Operator Characteristic (ROC) curve. Their discriminative ability increases as the error rate increases, and is greater if the genotyping error is in the direction of the minor allele. Optimal thresholds for detecting genotyping error vary for different allele frequencies and patterns of genotyping error but allele frequency-specific thresholds can be nominated. Applying these thresholds would have picked up about 90% of genotyping errors in our actual dataset. Measures of departure from HWE may be useful for detecting genotyping error, but this needs to be confirmed in other real datasets.
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Reduced change blindness suggests enhanced attention to detail in individuals with autism.
J Child Psychol Psychiatry
PUBLISHED: 03-25-2009
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The phenomenon of change blindness illustrates that a limited number of items within the visual scene are attended to at any one time. It has been suggested that individuals with autism focus attention on less contextually relevant aspects of the visual scene, show superior perceptual discrimination and notice details which are often ignored by typical observers.
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Involvement of the IGF system in fetal growth and childhood cancer: an overview of potential mechanisms.
Cancer Causes Control
PUBLISHED: 03-15-2009
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Fetal growth is determined by a complex interplay of genetic, nutritional, environmental, and hormonal factors. Greater than expected fetal growth has been positively associated with the risk of the development of some cancers in childhood, particularly acute lymphoblastic leukemia, and the biological mechanisms underlying such associations are thought to involve insulin-like growth factors (IGFs). Circulating IGF levels are highly correlated with fetal growth, and IGFs are believed to play an important role in carcinogenesis; however, these two bodies of evidence have not been well integrated and, as a result, the potential underlying biological mechanisms linking the IGF system with the development of specific childhood cancers have not been elucidated. This review aims to draw together and summarize the literature linking the IGF system, rapidity of fetal growth, and risk of some specific childhood cancers; suggest explanations for some of the inconsistencies observed in previous studies of these associations; and propose an integrated framework for the putative involvement of the IGF system in the development of at least some childhood cancers. If the challenges involved in studying the complex IGF system can be overcome, this field presents an exciting opportunity to elucidate etiological pathways to childhood malignancies.
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Independent component analysis reveals atypical electroencephalographic activity during visual perception in individuals with autism.
Biol. Psychiatry
PUBLISHED: 03-11-2009
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Individuals with autistic spectrum disorder (ASD) experience atypical visual perception, yet the etiology of this remains unknown. The aim of this study was to investigate the neural correlates of visual perception in individuals with and without ASD by carrying out a detailed analysis of the dynamic brain processes elicited by perception of a simple visual stimulus.
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Global and local perceptual style, field-independence, and central coherence: An attempt at concept validation.
Adv Cogn Psychol
PUBLISHED: 02-06-2009
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Historically, the concepts of field-independence, closure flexibility, and weak central coherence have been used to denote a locally, rather globally, dominated perceptual style. To date, there has been little attempt to clarify the relationship between these constructs, or to examine the convergent validity of the various tasks purported to measure them. To address this, we administered 14 tasks that have been used to study visual perceptual styles to a group of 90 neuro-typical adults. The data were subjected to exploratory factor analysis. We found evidence for the existence of a narrowly defined weak central coherence (field-independence) factor that received loadings from only a few of the tasks used to operationalise this concept. This factor can most aptly be described as representing the ability to dis-embed a simple stimulus from a more complex array. The results suggest that future studies of perceptual styles should include tasks whose theoretical validity is empirically verified, as such validity cannot be established merely on the basis of a priori task analysis. Moreover, the use of multiple indices is required to capture the latent dimensions of perceptual styles reliably.
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Vision in children and adolescents with autistic spectrum disorder: evidence for reduced convergence.
J Autism Dev Disord
PUBLISHED: 01-29-2009
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Evidence of atypical perception in individuals with ASD is mainly based on self report, parental questionnaires or psychophysical/cognitive paradigms. There have been relatively few attempts to establish whether binocular vision is enhanced, intact or abnormal in those with ASD. To address this, we screened visual function in 51 individuals with autistic spectrum disorder and 44 typically developing individuals by measuring visual acuity, stereoacuity, convergence, divergence, ocular motility, incidence of strabismus and integrity of the optokinetic response. The data suggest that many aspects of vision, including visual acuity, are unaffected in ASD, but that convergence is an aspect of visual function that merits further research in those with ASD.
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Parental alcohol consumption and risk of childhood acute lymphoblastic leukemia and brain tumors.
Cancer Causes Control
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Childhood acute lymphoblastic leukemia (ALL) is the most common childhood malignancy and brain tumors (CBTs) are the leading cause of cancer death in children. In our Australian case-control studies of these cancers, we investigated whether parental alcohol consumption before or during pregnancy was associated with risk.
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Parental occupational exposure to engine exhausts and childhood brain tumors.
Int. J. Cancer
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Childhood brain tumors (CBT) are the leading cause of cancer death in children; their risk factors are still largely unknown. Since most CBTs are diagnosed before five years of age, prenatal exposure and early postnatal factors may be involved in their etiology. We investigated the association between CBT and parental occupational exposure to engine exhausts in an Australian population-based case-control study. Parents of 306 cases and 950 controls completed detailed occupational histories. Odds ratios (OR) and 95% confidence intervals (CI) were estimated for both maternal and paternal exposure in key time periods. Increased risks were observed for maternal exposure to diesel exhaust any time before the childs birth (OR 2.03, 95% CI 1.09-3.81) and paternal exposure around the time of the childs conception (OR 1.62, 95% CI 1.12-2.34). No clear associations with other engine exhausts were found. Our results suggest that parental occupational exposure to diesel exhaust may increase the risk of CBT.
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The distribution of and relationship between autistic traits and social anxiety in a UK student population.
Autism
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Traits associated with autism and social anxiety were assessed in a UK student population (n = 1325) using the Autism-spectrum Quotient and the Liebowitz Social Anxiety Scale. Clinically relevant levels of autistic traits were observed in 3.3% of the cohort; 10.1% of the cohort reported clinically relevant levels of social anxiety; 1.8% of the cohort met clinically relevant cut-offs for both conditions. There was a significant positive correlation between scores on the two scales (r = .51); students with high levels of autistic traits were more likely to report increased social anxiety than those with average or low levels of autistic traits. Level of social anxiety was best predicted by autistic traits associated with social skill, attention switching and communication, accounting for 33% of the variance in social anxiety scores. Social skill was a better predictor of social anxiety in males than females; attention switching ability was a better predictor of social anxiety in females than males. Students with high levels of autistic traits displayed heightened anxiety to situations and activities necessary for the successful completion of their degree. Implications for student well-being and attainment are discussed.
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Statistical adjustment of genotyping error in a case-control study of childhood leukaemia.
BMC Med Res Methodol
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Genotyping has become more cost-effective and less invasive with the use of buccal cell sampling. However, low or fragmented DNA yields from buccal cells collected using FTA cards often requires additional whole genome amplification to produce sufficient DNA for genotyping. In our case-control study of childhood leukaemia, discordance was found between genotypes derived from blood and whole genome amplified FTA buccal DNA samples. We aimed to develop a user-friendly method to correct for this genotype misclassification, as existing methods were not suitable for use in our study.
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Maternal dietary intake of folate and vitamins B6 and B12 during pregnancy and the risk of childhood acute lymphoblastic leukemia.
Nutr Cancer
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Our aim was to address the hypothesis that maternal dietary intake of folate during pregnancy is inversely associated with risk of acute lymphoblastic leukemia (ALL) in the offspring. Dietary intake of folate, vitamins B6 and B12 in the last 6 mo of pregnancy from 333 cases and 695 frequency-matched controls were assessed using a food frequency questionnaire. Data were analyzed using unconditional logistic regression, adjusting for study matching variables, total energy, and potentially confounding variables. Higher levels of dietary folate and B12 appeared to be associated with a decreased risk of ALL. Higher levels of vitamin B6 were associated with an increased risk. The strongest associations of ALL with these variables were seen when mothers consumed alcohol in pregnancy. Our findings are consistent with a modest protective effect of higher dietary intake of folate and vitamin B12 against ALL in the offspring, more particularly among women who drank alcohol during pregnancy. These findings are consistent with previous reports of the protective effects of a maternal diet high in fruit, vegetables, and nondairy protein sources. The vitamin B6 findings are not consistent with evidence that it is a protective factor against other cancers, and may be a chance finding.
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Maternal use of folic acid and other supplements and risk of childhood brain tumors.
Cancer Epidemiol. Biomarkers Prev.
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Interest in a possible protective effect of maternal vitamin use before or during pregnancy against childhood brain tumors (CBT) and other childhood cancers has grown over the past decade. Our Australian study of CBTs, conducted between 2005 and 2011, investigated whether maternal use folic acid and other supplements was protective.
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Risk of childhood acute lymphoblastic leukaemia following parental occupational exposure to pesticides.
Occup Environ Med
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To ascertain whether there was an association between parental occupational exposure to pesticides and increased risk of acute lymphoblastic leukaemia (ALL) in the offspring.
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Participation in population-based case-control studies: does the observed decline vary by socio-economic status?
Paediatr Perinat Epidemiol
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An Australian study of childhood leukaemia (Aus-ALL) previously reported that control participation was positively associated with socio-economic status (SES). A similar study of childhood brain tumours (Aus-CBT) was carried out 4 years later, and this paper compares control participation and its relationship with SES in the two studies. To assess the representativeness of controls in terms of SES, the addresses of controls were linked to Australian Bureau of Statistics Census 2006 Collection Districts (CDs), and hence to area-based indices of SES. Independent sample t-tests and chi-squared tests were used to compare the SES indices of CDs where Aus-CBT controls lived with those where Aus-ALL controls lived and with those of all CDs where Australian families lived. The overall percentage of eligible families who agreed to participate was lower in Aus-CBT (53.9%) than in Aus-ALL (70.3%). Control families in both studies were of higher SES than the general population, while the distribution of SES among recruited controls was similar in both studies. These findings provide some reassurance that the observed decline in research participation over time may not be associated with an increasingly unrepresentative participant population.
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Right Temporoparietal Gray Matter Predicts Accuracy of Social Perception in the Autism Spectrum.
J Autism Dev Disord
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Individuals with an autism spectrum disorder (ASD) show hallmark deficits in social perception. These difficulties might also reflect fundamental deficits in integrating visual signals. We contrasted predictions of a social perception and a spatial-temporal integration deficit account. Participants with ASD and matched controls performed two tasks: the first required spatiotemporal integration of global motion signals without social meaning, the second required processing of socially relevant local motion. The ASD group only showed differences to controls in social motion evaluation. In addition, gray matter volume in the temporal-parietal junction correlated positively with accuracy in social motion perception in the ASD group. Our findings suggest that social-perceptual difficulties in ASD cannot be reduced to deficits in spatial-temporal integration.
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What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

How does it work?

We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

Video X seems to be unrelated to Abstract Y...

In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.