Neonatal mortality because of low birth weight or prematurity remains high in many developing country settings. This research aimed to estimate the sensitivity and specificity, and the positive and negative predictive values of newborn foot length to identify babies who are low birth weight or premature and in need of extra care in a rural African setting.A cross-sectional study of newborn babies in hospital, with community follow-up on the fifth day of life, was carried out between 13 July and 16 October 2009 in southern Tanzania. Foot length, birth weight and gestational age were estimated on the first day and foot length remeasured on the fifth day of life.In hospital 529 babies were recruited and measured within 24 hours of birth, 183 of whom were also followed-up at home on the fifth day. Day one foot length <7 cm at birth was 75% sensitive (95%CI 36-100) and 99% specific (95%CI 97-99) to identify very small babies (birth weight <1500 grams); foot length <8 cm had sensitivity and specificity of 87% (95%CI 79-94) and 60% (95%CI 55-64) to identify those with low birth weight (<2500 grams), and 93% (95%CI 82-99) and 58% (95%CI 53-62) to identify those born premature (<37 weeks). Mean foot length on the first day was 7.8 cm (standard deviation 0.47); the mean difference between first and fifth day foot lengths was 0.1 cm (standard deviation 0.3): foot length measured on or before the fifth day of life identified more than three-quarters of babies who were born low birth weight.Measurement of newborn foot length for home births in resource poor settings has the potential to be used by birth attendants, community volunteers or parents as a screening tool to identify low birth weight or premature newborns in order that they can receive targeted interventions for improved survival Despite important gains in the survival of children under five years in sub-Saharan Africa during the last twenty years, the neonatal mortality rate (NMR) remains virtually unchanged at 41 deaths within 28 days of birth for every 1000 live births. This currently represents an estimated 41% of all under five deaths .-16.11-16Here we report on the first African study of newborn foot length to identify low birth weight and premature babies and give the sensitivity and specificity estimates, and positive and negative predictive values for different foot length cut-offs. The aim was to determine the utility of using foot length as a screening tool in home delivery settings to identify low birth weight or premature babies in need of extra care. Our goal was to define a simple operational foot length cut-off that could be used to screen babies as follows: (1) babies who have an urgent need for care because they are very low birth weight (<1500 grammes); (2) babies who would benefit from additional care in the home because they have birth weight 1500-2499 grams or gestational age <37 weeks; and (3) babies who have birth weight >2499 grams and gestation age >36 weeks, and thus do not need special care because they are small.We conducted a cross-sectional study of newborn babies born in hospital, with a non random subset followed up at home on the fifth day of life. A clinical officer examined babies and measured their feet on the first day, an experienced field supervisor tracked and measured the feet of babies on the fifth day; a medical doctor supervised the work. All staff were trained together on the maternity ward for one week prior to the start of data collection, each repeating foot length, birth weight and gestational age measures and comparing findings.The research was carried out between 13 July and 16 October 2009 within the framework of an ongoing randomised controlled trial  called "Improving newborn survival in southern Tanzania" (INSIST). It is based in Lindi and Mtwara regions, a predominantly rural and poor area with high neonatal (43 per 1000 live births) and infant (76 per 1000 live births) mortality . SeventyDuring the study period, all babies born at the Mtwara Regional hospital, known as "Ligula hospital", were assessed for inclusion within 24 hours of birth and mothers asked to give informed written consent. Babies showing signs of any one of the following were excluded: severe respiratory distress, birth asphyxia, congenital deformity, birth weight <1000 grams or gestational age <28 weeks.On the first day of life, each baby recruited in hospital for whom consent was given had their right foot measured from the heel to the tip of hallux (big) toe using a stiff transparent plastic metric ruler. Birth weight was measured using digital Salter scales which were calibrated at each use with a bottle weighing 1000 grams. Gestational age was estimated by the Eregie method ,19 whichMothers were asked to give their home address and those estimated to live within 20 kilometres of the hospital were asked for permission for project staff to make a home visit on the fifth day of baby's life to re-measure foot length. This was then compared to the first day newborn foot length, birth weight, and gestational age estimate to explore the association up to five days after birth. Finally, project staff were asked to comment on the ease of implementation of the foot length measurement, and to report any perceptions of acceptability by parents.2 test for heterogeneity to look for evidence of difference between the two samples that could introduce bias. We defined three binary variables to describe outcomes: (1)less than 1500 grams (very low birth weight), (2)less than 2500 grams (low birth weight) and (3)less than 37 weeks gestation (premature). Babies with these outcomes are referred to as 'small' in this context.Data was entered directly into personal digital assistants at point of measurement on the first and fifth day of life, with internal consistency checks pre-programmed. Data was analysed using STATA version 10.0. The distribution of gender, birth weight, foot length and gestational age estimates for the babies measured on the first day and the fifth day subset were compared using ChiThe absolute difference in foot length measured on the first and the fifth day for individual babies was calculated. Non-parametric receiver operating characteristics (ROC) analysis was conducted on first and fifth day foot lengths for the three outcome variables. To generate a simple operational foot length cut-off for babies with low birth weight or prematurity, a range of foot lengths was then defined as those that approximated 80% sensitivity and 80% specificity across the three outcomes. Sensitivity, specificity, positive and negative predictive values were calculated for these foot lengths.The study was approved by the Institutional Review Board of Ifakara Health Institute, Tanzania, the Medical Research Coordinating Committee, Tanzania and the London School of Hygiene and Tropical Medicine, UK. Written, informed consent was obtained from the caregiver of each infant in the study.2 p > 0.05, table During the study period, 635 babies were born at Ligula Hospital of whom 529 (83%) were recruited to the foot length project and had their feet measured on the first day of life. According to maternal reports, 257 lived within 20 km of the hospital and of these 183 (71%) had their feet measured again on the fifth day of life , and the mean foot length of the 182 babies measured on the fifth day was 8.1 cm (SD 0.3). On average, each baby's foot was 0.2 cm (SD 0.3) longer on the fifth day than on the first day.Sensitivity and specificity estimates for different foot lengths measured on the first day to identify small babies are shown in figures Using this range of foot length estimates as a guide, we show in table Fourteen newborns (3%) had a foot length <7 cm, and 275 (52%) a foot length of <8 cm on the day of birth. Of the eight babies with birth weight <1500 g, six had foot length <7 cm and all had feet shorter than 8 cm. Of the 77 babies with birth weight <2500 g, 14 had foot length <7 cm and 67 had feet shorter than 8 cm. Of the 44 premature babies, 12 had foot length <7 cm and 41 had feet shorter than 8 cm.Newborn foot length of <7 cm had sensitivity and specificity of 75%  and 99%  respectively to identify birth weight <1500 grams, foot length of 8 cm had sensitivity and specificity of 87%  and 60%  respectively to identify birth weight <2500 grams, and foot length of 8 cm had sensitivity and specificity of 93%  and 58%  to identify premature babies.On day five, foot length of 8 cm had sensitivity and specificity of 77%  and 74%  respectively to identify low birth weight babies, and foot length of 8 cm had sensitivity and specificity of 79%  and 72%  to identify premature babies  for these foot length cut-offs were low, being highest at 43% for the 7 cm cut-off to predict very low birth weight. The negative predictive values (NPV) were high at 96% for low birth weight and 99% for very low birth weight table .Project staff reported that using the ruler to measure feet was simple to learn and to explain to others: overall, the approach was easily understood by parents. The exceptions were the four mothers who refused in hospital who reported a fear of association with measuring baby length for coffins, and the eight fathers who refused at the home visit because they had not been present for, or informed about, the participation in hospital on the first day.Measuring newborn foot length in Tanzania using a simple transparent plastic ruler can identify babies needing extra care because they are low birth weight or premature. A foot length of less than 7 cm at birth was75% sensitive and 99% specific to identify very low birth weight babies <1500 grams) and foot length less than 8 cm had sensitivity and specificity of 87% and 60% to identify those with low birth weight (<2500 grams), or 93% and 58% to identify those born premature (<37 weeks). The average newborn foot length increased by only 0.2 cm by the fifth day of life, and foot length measured on day five identified more than three-quarters of babies who were born small. The foot length cut-offs of 7 and 8 cm defined in this African setting were very similar to that previously recommended to identify small babies in Europe (7.2 cm) , and in 00 grams This was a cross sectional hospital based study of babies at birth with a community follow-up on the fifth day of life: findings suggest that measuring newborn foot length even days after birth could be useful to identify babies needing extra care. We defined 'small babies' both by birth weight and by gestational age but had a small sample size for analysis of the relatively rare occurrence of very low birth weight (<1500 g). Although the hospital based recruitment was not representative of the population level, the prevalence of low birth weight  was consistent with previous findings . Very liThe utility of an anthropometric surrogate to identify small babies in the community will largely be determined by the implementing environment . The LivIn 2009, WHO and UNICEF released a joint statement promoting community volunteer programmes to make home visits to newborns as a strategy to improve survival, especially where access to facility-based skilled care is limited . In TanzIn figure Two previous studies have reported high inter- and intra-observer agreement of foot length when measured by trained medical staff ,12. HoweIn resource poor settings where neonatal mortality remains disproportionately high, there are many missed opportunities to provide extra care to premature or low birth weight babies born at home. This study has shown that the simple and inexpensive measurement of newborn foot length can be used to screen for low birth weight and prematurity, with great potential for impact on newborn survival.The authors declare that they have no competing interests.TM and JAS were responsible for the study concept and design. Statistical analysis and interpretation was conducted by TM, JJ, SP, MT and JAS. TM wrote the first draft, TM, JAS, SP, JJ and MT revised the paper and contributed to discussion. All authors read and approved the final manuscript. TM acts as guarantor for the study.The pre-publication history for this paper can be accessed here:http://www.biomedcentral.com/1471-2458/10/624/prepub


Relationships between incidence of Wilms' tumour and information recorded at birth were investigated in a prospective study of the 1,489,297 children born in Norway between 1967 and 1992. A total of 119 individuals were diagnosed with Wilms' tumour in the age interval 0-14 years. A high length at birth was significantly associated with a high risk . A low Apgar score at 1 min was also associated with an increased risk . For all variables for which an association was indicated, the association seemed to be restricted mainly to children aged less than 2 years. This suggests that Wilms' tumour diagnosed early in life may differ aetiologically from that of cases diagnosed later.


Sir,We welcome the comments of van Noord concerning the different results for birth weight and breast cancer risk reported by ourselves (Reliable information on maternal age at birth was available in the Trondheim data, and hence this analysis is based on 186 breast cancer cases and 662 age-matched controls. We used conditional logistic regression to explore the association between the risk of breast cancer and maternal age at birth, and the estimated odds ratios are adjusted for age at first birth and parity. As shown in Although van Noord has proposed an interesting hypothesis, we found no evidence to support that maternal age at birth is positively associated with breast cancer risk. In light of our original findings, that both birth weight and birth length are positively associated with breast cancer risk, important mechanisms linking birth characteristics to breast cancer may be related to foetal growth. Recent research has shown that both birth weight and maternal pre-eclampsia are associated with adolescent growth and maturation (


SirWith great interest, I read the different results found for birth weight and birth length on adult breast cancer risk reported by in vitro fertilisations where successful implantation, among biologically older women, became possible again when their own less viable oocytes were coinjected upon conception with mitochondria from a younger mother  actually reflects the quality of the mitochondria with which an individual begins his or her life. This preconceptional mitochondrial hypothesis can also account for the opposing effects on carcinogenesis of caloric restriction and the role of free radicals that spill from the Krebs's cycle, as both relate to the proper functioning of the energy production by the mitochondria . This alThe role of mitochondria is relevant to the interpretation of the results of Vatten because they play such an essential role in cell metabolism through their production of energy/ATP. The correlation of maternal age at birth with mitochondrial viability would link a subcellular phenomena to those observable at the level of populations as can be studied by epidemiology. Several (breast) cancer risk factors in adult life such as adult height, age at first childbirth, BMI, age at natural menopause and breast dysplasia, show some correlation with maternal age at birth .Maternal age at birth may represent not just the biological age of the maternal oocyte, but may also reflect the age of the mother's mother , where the initial meiotic cleavage of such an oocyte occurred . From thafter imprinting and gastrulation, when by then the most crucial first cell cycles have already taken place (5) cells that cover 10% of all the 50 divisions an embryonic cell can make in a human lifetime (There are reasons to believe that all these periconceptional phenomena represent purely maternal-, and not paternal-inherited epigenetic aspects that operate well before another maternal factor, the postimplantation placenta-dependent intrauterine environment, of en place . All thelifetime . These flifetime  as well lifetime  or enzymlifetime . SuboptiThe increases in aneuploidy run parallel to the decline in fecundity in biologically older mothers . In the Birth weight and length at birth have not only been linked to IGF-2 but also to IGF-1. A role of the IGF-1 axis on breast cancer, however, has only been found for premenopausal breast cancers . Since bReanalysis of the data by Vatten and possibly also the data of Sanderson, using maternal age at birth instead of birth weight could test whether and, if so, to what extent, this preconception hypothesis on the role of mitochondria required for optimal cell function could better explain subsequent cancer risks.


Objectives: To investigate if live births conceived in months when surface water agrichemicals are highest are at greater risk for birth defects.Methods: Monthly concentrations during 1996–2002 of nitrates, atrazine and other pesticides were calculated using United States Geological Survey's National Water Quality Assessment data. Monthly United States birth defect rates were calculated for live births from 1996 to 2002 using United States Centers for Disease Control and Prevention natality data sets. Birth defect rates by month of last menstrual period (LMP) were then compared to pesticide/nitrate means using logistical regression models.Results: Mean concentrations of agrichemicals were highest in April–July. Total birth defects, and eleven of 22 birth defect subcategories, were more likely to occur in live births with LMPs between April and July. A significant association was found between the season of elevated agrichemicals and birth defects.Conclusion: Elevated concentrations of agrichemicals in surface water in April–July coincided with higher risk of birth defects in live births with LMPs April–July. While a causal link between agrichemicals and birth defects cannot be proven from this study an association might provide clues to common factors shared by both variables. The leading cause of infant mortality in the United States is birth defects , accountLarge-scale longitudinal human studies evaluating pesticide/nitrate exposure at the time of conception have not yet been performed in the United States. Concentrations of nitrates and pesticides in stream water may be an indication of human exposure levels. The United States Geological Survey's (USGS) National Water-Quality Assessment (NAWQA) study provides the most comprehensive national-scale analysis of pesticide occurrence and concentrations in streams and ground water. In the NAWQA study, pesticide concentrations were measured in water samples from 186 stream sites representing 51 hydrological systems from 1991 to 2002. The NAWQA study units account for 70% of total water use and 50% of the United States drinking water. Pesticides were found to be present in most stream water samples and over half of the ground water samples. Seasonal patterns of pesticide concentrations were found with the highest monthly concentrations in May and June  and other agencies indicating that seasonal variations in nitrates, atrazine and other pesticides may serve as markers for annual agricultural and urban pest-control activities. In the present investigation we sought to answer a qualitative question; are annual peaks in pesticides and nitrates  correlated with greater risk to pregnancies conceived in those months? If no increase in birth defects were found in April–July conceptions it might be inferred that the contaminant peaks pose little threat to human reproductive success.Surface water nitrates, atrazine and all other measured pesticide concentrations  were obtained monthly for each year between 1996 and 2002 from the USGS NAWQA database. Monthly pregnancy and birth outcome data were obtained from the Centers for Disease Control (CDC) natality database for the same years 1996–2002. Year of delivery, month of last menstrual period (LMP), presence of any birth defect and category of birth defect were recorded for each live birth. Maternal risk factors and demographics including alcohol use, tobacco use, diabetes, age, race and metropolitan or non-metropolitan residence were also recorded. Mother's month of LMP was used as a proxy for the time of conception and all birth defect rates were calculated based on cases per 100 000 live births for each LMP month. Stillbirths and abortion data were not used.Primary measures of interest are (i) dichotomous variables of total birth defects and individual birth defects and (ii) numerical variables of concentrations of agrichemicals including atrazine, nitrate and other pesticides. The major factor of interest is the monthly or seasonal factor, that is the months April–July versus other months. Other predictors/factors include maternal risk factors, maternal demographics and year of birth.We performed three major analyses in this study. First, dichotomous variables such as total and individual birth defects were assessed for their associations with the seasonal factor (a two-level factor of ‘peak’ season in months April–July and ‘off-peak’ season of other months) in a multivariate logistic regression model adjusting for other covariates such as maternal risk factors, maternal demographics and year. Second, agrichemicals were modelled with the seasonal factor using multivariate regression models, adjusting for years. Agrichemicals were log-transformed before performing multivariate regression analyses since their distributions were right skewed. Third, relationships between birth defects and agrichemicals were assessed using multiple logistic regression models, adjusting for maternal risk factors, maternal demographics and years. Both simple and multiple models were considered in this approach. The simple model used only one agrichemical as the major predictor of interest while the multiple models used all three agrichemicals as the predictor. All statistical analyses were performed using statistical software package SAS version 9.2 . p-value <0.05 was considered statistically significant.A total of 30.11 million births were studied between 1996 and 2002. Our study included 22 birth defect categories with the overall birth defect rate defined as any one birth defect. This report has shown that during the period from 1996 to 2002 women in the United States with LMPs in April–July (i.e. the time of conception) were significantly more likely to have a live birth with a birth defect than in other months. The report further demonstrates, using NAWQA surface water samples that concentrations of atrazine, nitrates and other pesticides also were higher in the months of April–July. The correlation between birth defects, pesticides and nitrates was statistically significant.Pesticides and nitrates, separately and in combination, have been linked to embryo toxicity and to untoward outcomes of pregnancy ,13. WomeIn Missouri men, high urine levels of atrazine, alachlor and diazinon were associated with abnormal sperm . The samA causal link between birth defects and environmental nitrates/pesticides is plausible but not proven from this present ecological study. Nevertheless a statistically significant increased risk was found for any birth defect and for spina bifida, circulatory, tracheal, gastrointestinal, urogenital, musculoskeletal anomalies, cleft lip, adactyly, clubfoot and Down's syndrome in women with LMPs between April and July in the United Sates . This peNitrates and pesticides occur as mixtures in most water samples . Recent This study has many limitations. Vital records have limited reliability and validity and should be used with caution . As of MUsing NAWQA water data as a proxy for human exposure have significant limitations as well. Drinking water sources vary from surface to ground water and varied mixtures at different times of the year are common. Mean levels of nitrates and pesticides in NAWQA test sites are significantly higher than drinking water means would be in most locations. Nevertheless, in an EPA drinking water data sample from the same time period, peak frequency of pesticide detections were found in June, and correlated qualitatively with NAWQA surface water data. Atrazine was found in 57.9% of drinking water samples in Maryland  and 87% in utero and most are exposed to mixtures of several pesticides  found that 95% of the United States population has measurable pesticide metabolites in urine samples . AlthougBirth defect rates in the Unites States were found to be highest for women conceiving in the spring and summer . This increase was significant for 11 of the 22 categories of birth defects reported in the CDC natality database from 1996 to 2002. A significant association was found between the months of increased risk of a birth defect (April–July) and increased levels of nitrates, atrazine and other pesticides in surface water. Critical time periods before and after conception may link seasonal peaks in environmental contaminants to certain birth defects.


Objective. Individuals with inflammation have a myriad of pregnancy aberrations including increasing their preterm birth risk. Toll-like receptors (TLRs) and receptor for advanced glycation end products (RAGE) and their ligands were all found to play a key role in inflammation. In the present study, we reviewed TLR and RAGE expression, their ligands, and signaling in preterm birth. Research Design and Methods. A systematic search was performed in the electronic databases PubMed and ScienceDirect up to July 2010, combining the keywords “preterm birth,” “TLR”, “RAGE”, “danger signal”, “alarmin”, “genomewide,” “microarray,” and “proteomics” with specific expression profiles of genes and proteins. Results. This paper provides data on TLR and RAGE levels and critical downstream signaling events including NF-kappaB-dependent proinflammatory cytokine expression in preterm birth. About half of the genes and proteins specifically present in preterm birth have the properties of endogenous ligands “alarmin” for receptor activation. The interactions between the TLR-mediated acute inflammation and RAGE-mediated chronic inflammation have clear implications for preterm birth via the TLR and RAGE system, which may be acting collectively. Conclusions. TLR and RAGE expression and their ligands, signaling, and functional activation are increased in preterm birth and may contribute to the proinflammatory state. Preterm birth (delivery prior to 37 weeks gestation) occurs in around 10% of all deliveries and is the most significant problem encountered in obstetrics including neonatal morbidity and mortality , 3. InfeA comprehensive mapping of the proteome and microarray analysis was provided by several investigators –15. ReceThe harmful effects of cytokines are mediated by specific receptors for inflammation. Toll-like receptors (TLRs) are the most extensively studied signaling receptors that participate in the initiation of inflammation . SeveralThe present paper reviews the English language literature for biological, pathogenetic, and pathophysiological studies on preterm birth. We searched MEDLINE (PubMed) electronic databases for a 20-year period (1990–2010), combining the keywords “preterm birth”, “TLR”, “RAGE”, “danger signal”, “alarmin”, “genome-wide,” “microarray,” and “proteomics” with specific expression profiles of genes and proteins. Several recent studies are discussed in the context of pathogenesis of preterm birth. Additionally, references in each paper were searched to identify potentially missed studies for a 20-year period. Here, we discuss promising molecular candidates for preterm birth.Recent advances in the application of various platforms have facilitated the process of discovery of novel biomarkers of preterm birth. These analyses include the DNA microarray experiment, principal component analysis, pathway analysis, signaling networks analysis, or proteomics analysis using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) techniques. Recent progress in the microarray, or proteomics-based technologies allows researchers to perform screening to detect differentially expressed genes and proteins in preterm birth subjects. Maternal serum and plasma, amniotic fluid, cervicovaginal fluid, urine, or placental trophoblasts, fetal membranes or cord blood have been used to develop markers for preterm birth.The first aim of this study was to review molecular factors predictive of preterm birth by reviewing biochemical research identifying gene and protein expression profiles. Specific genes differentially expressed in preterm birth subjects are shown in A number of “preterm birth signature” genes involved in inflammation and immune system were specifically expressed, suggesting that excessive induction of the inflammatory response is a well-characterized cause of preterm birth. The expression of cytokines  by either the maternal, fetal, or placental tissues has been demonstrated to upregulate the activity of a number of uterine and cervical factors , leading to premature initiation and progression of the parturition process . The anaThe S100A5 gene is a member of the S100 family of proteins containing 2 EF-hand calcium-binding motifs. Some members are secreted from cells upon stimulation, exerting cytokine- and chemokine-like extracellular activities via the Receptor for Advanced Glycation End products, RAGE (see below) . S100 prUterine cervix is composed of extracellular matrix components such as collagen, elastin, proteoglycans, hyaluronan, and others. Cervical remodeling includes softening, ripening, dilatation, and repair. New insights propose that infection-induced premature cervical remodeling is distinct from the normal process –42. The Systemic or local inflammatory effects can influence cervical tissue remodeling , 44. MorTissue remodeling in the uterine cervix depends on precise networks to fine tune the balance between proteases and inhibitors. The balance between plasminogen activator inhibitor-1 (PAI-1) and urokinase (uPA) and tissue-type plasminogen activator (tPA) is an important determinant of proteolytic activity at the maternal-fetal interface , 49. CatKey mediators of the innate immune system during pregnancy are the natural antimicrobial peptides, including secretory leukocyte peptidase inhibitor (SLPI), elafin and the defensins, may account for some of the antimicrobial activity of amniotic fluid , 7, 60. The purpose of the second aim of this study was to undertake a comprehensive review of exogenous and endogenous ligands, their receptors, and downstream signaling in preterm birth subjects. The innate immune system possesses pattern recognition receptors (PRRs) that recognize pathogen-associated molecular patterns (PAMPs) that are specific to microbes. These PRRs include Toll-like receptors (TLRs), nucleotide-binding domain leucine-rich repeat containing receptors (NLRs), RIG-I-like RNA helicases (RLHs) and C-type lectin receptors (CLRs) . TLRs are evolutionarily preserved pattern-recognition receptor molecules that recognize the molecular patterns of pathogens . TLR actInterestingly, TLRs 1-10 are expressed in the female reproductive tract . The TLRExperimental evidence in animals demonstrates that TLR4 activation leads to the development of preterm birth . While tIn addition, the NLR  family of intracellular sensors is a crucial component of the innate immune system . The cytThe most frequently involved pathogens are thought to originate from the genital flora  , 80 Fig. AlthougA number of animal studies have described a role of TLRs for controlling bacterial infection and its impact on preterm birth , 83. InfIn placenta, gram-positive bacteria cell wall component peptidoglycan induces trophoblast apoptosis . FurtherBased on the proteomic discoveries, it has been propose that not only acute phase (IL-6 or PAMPs) but also chronic phase of the inflammatory and stress response is associated with preterm birth . The chrHeat shock proteins (HSPs) such as HSP60, HSP 70, HSP72, and HSP 90 are representative endogenous ligands for TLRs or RAGE . In geneIncreased circulating HSP70 level may not only be a marker of these conditions but might also play a role in their pathogenesis . IncreasWith great advancements in proteomics, new preterm birth biomarkers have been, and continue to be, discovered. Amniotic fluid biomarkers relevant for preterm birth are S100A12, S100A8, S100A9, defensin-1, defensin-2, and IGFBP-1 . S100 prImmune activation represents an adaptive reaction triggered by both exogenous (microbes) and endogenous inducers of inflammation . High-moProteins specifically present in preterm birth may have the properties of an endogenous alarmin. They include fibrinogen, fibronectin, heparan sulfate proteoglycan, hyaluronic acid, low-molecular weight hyaluronic acid, tenascin-C, neutrophil defensin 1, defensin 2, eosinophil-derived neurotoxin (EDN), lipocalin 2, fatty acid, apolipoprotein A-I, E and H (beta-2-glycoprotein I), oxidized LDL, lipoprotein, lipopeptides, annexin A2, amyloid beta A4 protein precursor, interferon- (IFN-) gamma, and lung surfactant protein, surfactant protein A . Among tRecent study on genetic polymorphism and contributions to disparities in preterm birth demonstrated that candidate genes include those involved in the host response to inflammation and those involved in the degradation of the extracellular matrix . They inThis paper provides key evidence for increased TLR and RAGE expression, activation, exogenous and endogenous ligands, and downstream signaling contributing to inflammation seen in preterm birth subjects , 75, 88.The paper largely consists of a series of summaries reporting experimental or clinical evidence for the involvement of each particular receptor, factor, or downstream signaling system. “Alarmins” might be more important for the development of preterm birth, leading to a chronic pro-inflammatory state by the activation of TLRs and RAGE. RAGE has been implicated in chronic diseases such as diabetes, atherosclerosis, neurodisorders, cancers, and aging. Signalling pathways downstream of RAGE are activated by the accumulation of its ligands “alarmins.” A major event in the functional activation of TLRs and RAGE results in NF-kappaB activation and cytokine production . RAGE biIn conclusion, the interactions between the TLR-mediated acute inflammation and RAGE-mediated chronic inflammation might have clear implications for preterm birth via the innate immune system. Taken together, the basic findings of this comprehensive review suggest that there is significant elevation of TLRs and RAGE, endogenous ligands, and cofactors in preterm birth patients, which contributes to the increase in chronic stress signaling and persistent pro-inflammatory state of preterm birth. These genes and proteins significantly elevated in preterm birth subjects may provide a foundation for further validation in larger patient cohorts. Future studies will address the mechanism of synergistic effects of endogenous ligands on TLR and RAGE signaling.


EHP 115:1670–1676; Apelberg et al.][.Scientists have accumulated a wealth of evidence that perfluorooctane sulfonate (PFOS) and perfluorooctanoate  accumulate in the environment and humans. Animal studies have shown these compounds to cause a variety of health effects, including reduced birth size and infant mortality. Now researchers are presenting the first evidence to suggest that human exposure to the chemicals is linked to reduced birth weight PFOS, PFOA, and related polyfluoroalkyl compounds (PFCs) that can be transformed into these chemicals in the environment are used in a wide range of consumer applications, including oil and water repellents for fabric, apparel, and carpets, and paper coatings such as fast-food wrappers. The chemicals have been found in the blood of people throughout the world.in utero exposure) had lower birth weights. The authors calculate the reduction as −69 g for PFOS and −104 g for PFOA. The study population included 293 infants born in Baltimore, Maryland, in 2004 and 2005. In earlier research, PFOA had been found in all these infants, and PFOS had been found in 99% of them. Infants with higher levels of PFOS and PFOA also had smaller head circumferences and lower scores on the ponderal index, a measure of body mass at birth. The study was not designed to allow the cohort to be followed in the future.The new study shows that infants born with higher concentrations of PFOS and/or PFOA in their umbilical cord serum (a measure the researchers used as a marker of The results are consistent with those of toxicologic studies conducted with mice and rats that also have linked exposure to PFOS and PFOA with low birth weight—albeit at doses that resulted in much higher body burdens than those seen in the Baltimore infants. Both compounds have also been tied to developmental delays in animal studies. Previous studies in humans have correlated low birth weight with obesity, diabetes, and cardiovascular diseases later in life.The researchers stress that the effect was small but statistically significant. They also note that the concentrations of PFOS, PFOA, and other PFCs in the infants’ blood were relatively low compared with levels tested in other studies.The results were statistically adjusted to consider other potential sources of altered birth weight, such as maternal smoking, diabetes, and hypertension. The new study did not find a correlation between levels of the compounds and socioeconomic status, as had previous research. The researchers also found no evidence of an association between the infants’ exposure to the chemicals and their cholesterol or triglyceride levels, despite previous human and animal studies suggesting that these blood lipids are particularly sensitive to PFC exposure.


Research evidence suggests that exposure to ambient air pollutants can adversely affect the growth and development of the foetus and infant survival. Much less is known regarding the potential for an association between black smoke air pollution and stillbirth risk. This potential association was examined using data from the historical cohort UK Particulate Matter and Perinatal Events Research (PAMPER) study.Using data from paper-based neonatal records from the two major maternity hospitals in Newcastle upon Tyne (UK), a birth record database of all singletons born during 1961–1992 to mothers resident in the city was constructed. Weekly black smoke levels were obtained from routine data recorded at 20 air pollution monitoring stations over the study period. A two-stage statistical modelling strategy was used, incorporating temporally and spatially varying covariates to estimate black smoke exposure during each trimester and for the whole pregnancy period for each individual pregnancy. Conditional logistic regression models, with stratification on year of birth, were used to assess potential associations between black smoke exposures in pregnancy and stillbirth risk.The PAMPER database consists of 90,537 births, between 1962 and 1992, with complete gestational age and residential address information, of which 812 were stillborn. There was no association between black smoke exposures in any trimester or across whole pregnancy and risk of stillbirth. Adjustment for potential confounders did not alter these results.While black smoke in pregnancy is likely to be related to other pregnancy outcomes, our findings do not suggest that black smoke air pollution exposure during pregnancy increases the risk of stillbirth. The effculates) . Associaculates) .A growing body of evidence now also suggests that exposure to ambient air pollutants, including particulates, can adversely affect the growth and development of the foetus   and infaPrevious research into risk of stillbirth associated with particulate air pollution is limited. The three studies included in the systematic review reported little evidence of an association between exposure to particulate matter and stillbirth risk . HoweverThe aim of this study was to investigate further the potential association between ambient particulate matter and stillbirth risk, using individual-level information from the UK Particulate Matter and Perinatal Events Research (PAMPER) births database, an historical cohort study of all singleton births in Newcastle upon Tyne during 1961–1992 .2The PAMPER birth cohort consists of all singletons born during 1961–1992 to mothers resident in the city of Newcastle upon Tyne  in the northern region of England. The population structure of the northern region is characterised by a low percentage of ethnic minorities, of about 2% and a relatively stable population with low levels of both inward and outward migration . A compuThe birth data were linked to information on stillbirths from the Office for National Statistics (ONS) for 1961–1992 to obtain data on cause of death. The linkage was based on date of birth, vital status (stillbirth), place of delivery and infant sex for 1961–1962. For 1963–1992 baby’s birth weight (where recorded), maternal age category and multiple birth indicator were also available as additional linkage variables. Among the total of 1248 eligible  stillbirths provided by the ONS for the study period, 1222 (97.9%) were matched to the PAMPER database. For cross-validation we also linked PAMPER data to stillbirth data from the Northern Perinatal Mortality Survey (PMS) (available form 1981 onwards) . Causes For consistency across the study period we defined a stillbirth as the birth of a dead baby at 28 or more completed weeks of gestation . Four stillbirths with unknown gestational age and birth weight less than 500 g were excluded.X–Y co-ordinates) or, where a complete postcode could not be identified, a grid reference directly. Townsend Deprivation Score (TDS), an area-based measure of socio-economic status incorporating the proportion of home ownership, car ownership, unemployment and overcrowding, was calculated at the enumeration district level using data from the 1971, 1981 and 1991 UK Census Surveys.All births were assigned unique spatial identifiers (postcodes and/or grid references). For births before 1970 (i.e. prior to the introduction of postcodes), the address at birth was assigned a postcode from the 1991 postcode book and converted to a grid reference  are reported. Although variables are presented categorically in descriptive tables, all conditional logistic regression analyses used continuous, or for parity, ordinal, data for all variables other than infant sex. A further analysis limiting cases of stillbirth to those due to antepartum hypoxia, which reflect intrauterine growth retardation, was also done.Potential associations between estimates of black smoke and risk of stillbirth were investigated using conditional logistic regression, with stratification on year of birth to account for the dramatic decrease in stillbirth rates over the study period. An analysis by time period  is also presented. Odds ratios (ORs) per 10 μg/mThe statistical software package Stata, version 10,  was used for all statistical analyses.2.3The study received a favourable ethical opinion from the Sunderland Local Research Ethics Committee.3The PAMPER database contains details of 109,080 births. Of the 90,537 births with complete gestational age information and black smoke exposure estimates, 812 were stillborn . The distribution of births included in this study by time period, sex parity and maternal age is shown in n=563).There were no significant associations between stillbirth risk and any of the black smoke exposure estimates during pregnancy, either for the whole study period or in any of the time periods considered . Adjusti4A growing body of evidence suggests that exposure to ambient air pollutants, including particulates, can adversely affect the growth and development of the foetus   and infaIn contrast to the previous studies which have been ecological or time-series in design with relatively crude measures of exposure, this study used individual-level exposure estimates on a large unselected birth cohort. Completeness of the PAMPER database both for the number of births and collected information for each birth is one of the evident strengths . The stuThe black smoke recordings used in this study were collected routinely over the study period, although not all monitors were in place throughout the study period, creating likely geographical differences in uncertainties surrounding our estimated exposures. In addition, monitoring procedures reflected best practise at the time and are thus the best estimates available, although their accuracy would have varied over time.Residential mobility during pregnancy may be associated with exposure misclassification and therefore may introduce bias. It has been reported for the United States, Canada and Australia that 25–33%, 12% and 19% of the population move during pregnancy, respectively . Whilst The accuracy of gestational age estimates is important for epidemiologic studies of pregnancy outcomes. Different methods for gestational age assessment  or early ultrasound measurements) throughout the study period may introduce bias in gestational age estimation over time. However, while creating our birth record database, we made the recording of gestational age as objective and accurate as possible by accepting gestational age calculated from the recorded estimated date of delivery (EDD) (i.e. LMP based) for the majority of births rather than by entering gestational age recorded in the neonatal notes or birth records. In this study the ultrasound age estimate has been used since the early 1980s only for pregnancies with uncertain date of LMP or if there was a significant discrepancy between the two estimates, therefore it should not bias gestational age estimates over time . Further, as the live and stillbirths in this study were effectively matched on year of birth, any difference in the quality of records over time would be unlikely to introduce a bias.As the legal cut-off in gestational age for stillbirth was changed to 24 weeks in October 1992 in England and Wales , only str=−0.84) and the substantial decline in stillbirth rates over the study period, year of birth is likely to confound any association between stillbirth risk and black smoke. Therefore we chose to use a conditional model, stratified by year of birth. This effectively matches stillbirths to live births by year of birth, though maintains the entire dataset for analysis and utilises the entire exposure range across a year, while adjusting for the known decrease in stillbirth rates over time. We also analysed the data in three different time periods to address whether associations may only be evident in certain time periods, for example due to much higher exposures in the earlier years of the study, or due to the changing composition of black smoke air pollution over the study period. No significant associations were seen in any of these analyses.Given the strong inverse correlation between black smoke exposure during pregnancy and year of birth (While black smoke in pregnancy may be adversely related to other pregnancy outcomes, our findings do not suggest that black smoke air pollution exposure during pregnancy increases the risk of stillbirth.


We found no increased risk for brain tumour after ultrasound exposure, either for all tumours or for any subgroup.We carried out a nationwide case–control study of childhood brain tumours in Sweden ( Since prenatal ultrasound scanning was introduced more than 40 years ago , althougPrevious studies on prenatal ultrasound exposure and childhood cancer have failed to show any clear association  before the age of 15. The same number of controls were randomly selected from the Medical Birth Register and frequency matched to cases by gender and year of birth. With this sample and assuming a power of 80%, a two-sided 5% significance level and an ultrasound exposure frequency of 50%, we estimated that we should be able to detect an odds ratio (OR) of at least 1.4 for all CBT. For 62 out of the 601 cases, the information on personal identification numbers or hospital of birth was incomplete or missing, which made it impossible to identify their antenatal records. Out of the remaining 539 cases, we retrieved antenatal records for 512 (95%), and for the 539 controls, 524 antenatal records (97%).Information on mother's reproductive history and obstetric parameters was retrieved from the Medical Birth Register. From the antenatal records, we extracted information on ultrasound exposure, including gestational age at exposure and number of examinations. All data collections were blind to case/control status. Individual record linkage was made possible by the personal identification number assigned to each Swedish resident at birth.Associations were evaluated for all types of CBT combined and by the following subtypes: low-grade astrocytoma, high-grade astrocytoma, primitive neuroectodermal tumour (PNET), ependymoma, germ-cell tumour or other rare and incompletely specified tumours.A priori, we identified potential confounding factors that could interfere with both ultrasound exposure and outcome (CBT), and for which it was possible to retain information from either the registers or the antenatal records. The following confounders were included in the adjusted analyses: maternal age at birth, parity, multiple births, mother's country of birth  or non-Nordic country), mother's smoking habits, hypertension, mode of delivery, breech position, gestational age at birth, birth weight, head circumference at birth and the level of hospital where born. Statistical analyses were conducted with the SAS 9.1 software package. A detailed description of population and study methods has been published elsewhere  were calculated. This study was approved by the Ethics Committees at Karolinska Institutet and Uppsala University.P=0.01), and to be born at a primary- or secondary-level hospital (P=0.04), than for controls. No other significant differences between cases and controls were seen in maternal and neonatal characteristics  for case mothers and 45.7% (n=240) for control mothers. All ultrasound examinations were performed abdominally and none involved Doppler ultrasound. In The overall exposure rate for ultrasound was 44.1% . Although not statistically significant, this slightly increased risk may indicate that children followed-up with further scans had some confounding factor unknown to us and therefore not adjusted for.Ultrasound can damage the biological tissue by heating, cavitation or streaming. Whether any of these mechanisms is carcinogenic is not known, but experimental studies on tissue cultures have shown that ultrasound with intensities used for prenatal scanning can damage cell membranes (One of the main potential biological effects of prenatal ultrasound is heating. Bone has the highest absorption coefficient for heat, and as the CNS tissues are encased in the skull or vertebrae, the CNS can be subjected to heating by conduction . The inc−2 spatial peak temporal average intensity (−2 for any type of ultrasound examination (No carcinogenic effect of prenatal ultrasound exposure was found in this or previous studies (mination . The sus


It is unclear whether the socioeconomic status (SES) of the community of residence has a substantial association with infant birth weight. We used multilevel models to examine associations of birth weight with family- and community-level SES in the Cape Cod Family Health Study. Data were collected retrospectively on births to women between 1969 and 1983 living on Cape Cod, Massachusetts. The sample included siblings born in different residences with differing community-level SES.We used cross-classified models to account for multiple levels of correlation in a non-hierarchical data structure. We accounted for clustering at family- and community-levels. Models included extensive individual- and family-level covariates. SES variables of interest were maternal education; paternal occupation; percent adults living in poverty; percent adults with a four year college degree; community mean family income; and percent adult unemployment.Residual correlation was detected at the family- but not the community-level. Substantial effects sizes were observed for family-level SES while smaller magnitudes were observed for community-level SES. Overall, higher SES corresponded to increased birth weight though neither family- nor community-level variables had significant associations with the outcome. In a model applied to a reduced sample that included a single child per family, enforcing a hierarchical data structure, paternal occupation was found to have a significant association with birth weight (p = 0.033). Larger effect sizes for community SES appeared in models applied to the full sample that contained limited covariates, such as those typically found on birth certificates.Cross-classified models allowed us to include more than one child per family even when families moved between births. There was evidence of mild associations between family SES and birth weight. Stronger associations between paternal occupation and birth weight were observed in models applied to reduced samples with hierarchical data structures, illustrating consequences of excluding observations from the cross-classified analysis. Models with limited covariates showed associations of birth weight with community SES. In models adjusting for a complete set of individual- and family-level covariates, community SES was not as important. Birth weight is a measure of overall infant health and a predictor of death and long-term disability . PreviouResearchers turned to multilevel models to examine the impact of family- and community-level SES on birth weight while accounting for residual community level correlation between subjects ,4,9,10. Traditional multilevel models were limited by the requirement of a single child per household. If siblings born in the same community were included in the sample a third level would be introduced to the multilevel analysis: the child-level, family-level, and community-level. The model would assume children were nested within families and families were nested within communities . Models However, it is not reasonable to assume that the family lived in the same community for all births. Relocation is relatively common as 47% of United States residents reported relocation between 1965 and 1970  and, in The purpose of this paper is three-fold. The first objective is to evaluate the importance of family- and community-level measures of SES in predicting birth weight in the Cape Cod Family Health Study, a retrospective cohort study conducted on Cape Cod, Massachusetts. This study provides an example of a non-hierarchical data structure with siblings born in different communities. To the best of our knowledge, no previous research has examined the multilevel association between family- and community-level SES and birth weight allowing for a non-nested data structure. The second objective is instructive as we illustrate how such non-hierarchical data can be appropriately analyzed and give recommendations for the analysis of multilevel data in general. As we collected extensive individual- and family-level information about our study participants, our third objective is to compare the results of multilevel models using full confounder information with those of models including limited data typically found in birth records. From these analyses we are able to assess confounding of birth weight associations with SES in our study population.The Cape Cod Family Health Study is a retrospective cohort study designed to investigate the relationship between environmental PCE  exposure from contaminated drinking water and reproductive health outcomes on Cape Cod, Massachusetts. Children were eligible for the study if they were born between 1969 and 1983 to a mother living in one of eight Cape Cod towns . We restThese data provided an opportunity to examine predictors of birth outcomes at child-, family-, and community-levels. Current analyses focused on birth weight, obtained from birth certificates. We selected continuous birth weight as it provides an opportunity to apply cross-classified models to a continuous outcome. Child- and family-level data were ascertained through birth certificate review and self-administered questionnaires sent to the mothers in 2002-2003. For community-level variables, study mothers' residential addresses at time of birth were linked to census data from 1980. These data were closest to the birth years of children in the study: 89% were born between 1974 and 1983. Community-level data was purchased from GeoLytics  at the enumeration district level. Enumeration districts are roughly the same size as census tracts and were used to designate communities as Cape Cod was not divided into census tracts until after 1980 .Predictors of interest included family- and community-level SES variables. At the family-level, SES was measured by maternal education  and paternal occupation  at time of birth. Community-level SES measures included percent adults living in poverty, mean family income, percent adults graduated from a four-year college, and percent unemployment in the enumeration district of residence. Mean family income and percent adults graduated from a four-year college were parameterized by quartiles while percent adults living in poverty and percent unemployment were dichotomized at 0 and 10%, respectively, based on evidence of a clear cut point from an unadjusted locally-weighted running-line smoothing (LOESS) plot .Other confounding variables were selected based on known relevance to birth weight. From birth certificate review we included child gender, gestational duration (> = 37 weeks), birth order, year of birth, maternal age, and adequacy of prenatal care. From survey questionnaires we obtained information on the adequacy of maternal weight gain, maternal history of cervical incompetence, and smoking and alcohol consumption during pregnancy. Family-level covariates included maternal race from birth certificate review, maternal history of diabetes or hypertension before or during pregnancy and history of prior low birth weight (birth weight < 2500 g) or premature (gestation < 37 weeks) infants from the questionnaire.Differences between family-level SES measures could occur between siblings due to changes in paternal occupation, maternal education, or paternity. Differences between community-level SES measures could occur due to family relocation between child births.Smooth LOESS plots  were useWe expected residual correlation within families and enumeration districts as siblings likely have correlated birth weights after adjusting for other predictors due to genetic similarities. Children within enumeration districts may also have comparable birth weights due to similar parental behaviors or environmental exposures. We used a mixed model with random intercepts for family and enumeration district to account for these correlations.The mixed model was non-hierarchical due to cross-classification of sibling births between enumeration districts. The applied model was a mixed linear regression model as follows:Yijk represented the birth weight of the kth child from the jth family living in the ith enumeration district. The term α represented the intercept, Xk the child- and family-specific demographic characteristics, and Wi and Vj represented the community- and family-level SES values, respectively. The corresponding regression coefficients were β, λ, and γ. di and fj were random intercepts for enumeration district and family [d family . FormallThree mixed linear regression models were compared to evaluate the necessity of random intercepts. Model I included random intercepts for enumeration district only, Model II had random intercepts for family only and Model III allowed for variation between both family and enumeration district means. It was assumed that family and enumeration district effects were distinct and the variances of each level could be identified. Table  HypothesWe applied two additional cross-classified models to evaluate possible confounding of family- and community-level SES measures. Model IIIa excluded family-level SES variables while Model IIIb excluded community-level SES variables. Table Two models were performed using restricted samples to impose a hierarchical data structure and avoid the need for cross-classified models. For Model IV, the sample was restricted to the eldest child per family. Random intercepts for enumeration district were included. Model V allowed multiple children per family but required that all children be born in the same enumeration district creating a nested hierarchy. In this sub-sample, later-born children were considered eligible if they were born in the same enumeration district as the eldest child. Random intercepts were included for both family and enumeration district.Predictors of primary interest were family- and community-level SES measures. All analyses were adjusted for relevant covariates. We tested for confounding by PCE exposure but found no association with the outcome. As a result, the models presented do not control for PCE exposure.We analyzed a birth certificate covariates only model (Model VI) to test for association between community-level SES and infant birth weight adjusting only for variables selected from birth certificate review. Variables reflected those used in the previous research that found significant associations between community SES and birth outcomes: child birth order, gender, birth year, adequate prenatal care, maternal age, maternal race, and maternal education ,4,8. To All analyses were performed using SAS Version 9.1 .  Subjects with at least one missing covariate were excluded from analyses. (n = 240) No single covariate had more than 5% missing values. The final sample included 1,449 children from 1,252 families living in one of 170 enumeration districts. Of those families, 175 had between two and four children in the study and 34 families moved between enumeration districts at least once between births. On average, enumeration districts included 9 children, with a range of 1 to 79. There was evidence of variation in birth weight: the sample mean was 3524.0 g and the standard deviation was 466.4 g. The standard deviation of family mean birth weight was 460.0 g while the standard deviation of mean birth weight in enumeration districts was smaller (247.8 g). This is a crude illustration that enumeration districts accounted for less variation in birth weight than families.Infants were nearly 50% female with an average gestational duration of 40.2 weeks. Fewer than 5% of mothers had a history of giving birth to a low birth weight infant, 8% had a history of hypertension, and over 95% of mothers were white. Over one-fourth of mothers smoked during pregnancy and nearly 40% consumed alcoholic beverages, both behaviors have been shown to decrease birth weight ,22 . The estimates for some community-level SES measures changed by more than 10% suggesting confounding of the community-level effects by the two family-level measures; however the magnitudes of the effects remained small. When the community-level SES variables were excluded from the model (Model IIIb) there were small change to the coefficients of the family-level SES measures indicating little confounding by the community-level measures. Table Model IV was applied to the eldest eligible child per family, excluding 262 later-born children from the analysis. Model V was applied to eligible eldest children and later-born children born in the same enumeration district as the eldest child.  Increased maternal education effect sizes were observed for Models IV and V when compared to Model III. Most notably, the effect size was increased considerably for the comparison of women without a high school diploma to those who have attended some college for the models applied to sub-samples. In Model IV, paternal occupation was significantly associated with birth weight. (p = 0.033) Fathers with blue collar occupations had children with significantly lower birth weights than white collar occupations (p = 0.024) while no difference was detected between white and "other" occupations. (p = 0.651) Paternal occupation in Model V had a p-value just over the 5% cut-off, (p = 0.057) indicating a possible trend in the same direction as Model IV. Similar effect sizes were observed for all community-level SES variables in Models III, IV, and V.  had coefficient magnitudes of only 3.15 and 3.29 g per one unit increase in the corresponding variables when predicting birth weight. In analyses adjusted for fewer covariates these variables had coefficient magnitudes greater than 20 and 10 g per one unit increase, respectively. Interestingly, community-level variables capturing stress in the neighborhood, violent crime rate and reciprocated mutual support were more important predictors than percent of families living in poverty or residential stability with coefficient magnitudes greater than 10 g per unit increase in a model with limited covariates and magnitudes greater than 6 g per unit increase in a full model . Other sWhen we compared the individual-level factors included in previous studies, we found that studies with moderate to large associations between community-level SES and birth outcomes adjusted for a small number of individual-level covariates. These papers focused on community variables and did not control for known risk factors and possible mediators such as gestational duration and smoking status during pregnancy ,4,8. We No previous study allowed or accounted for multiple children per family. Statistical models assumed either nested data ,8-10 or When drawing samples from populations with a primary interest in community-level variables, subjects often fall into subgroups within communities. In the present study, subgroups were families. We found that sibling birth weights were highly correlated and between-family variation accounted for much of the overall birth weight variation. Incorrectly assuming that subjects are independent may lead to incorrect variability estimates and test statistics.Analysts often assume random components are needed without considering alternate models. In the present study we found that adjustments for within-family correlations were important; however, there was little variability between enumeration districts and random components for enumeration district would be excluded in the most parsimonious model. Similar results indicating small community-level correlations have been found in other studies ,17 emphaMultilevel models are a common tool for examining associations between outcomes and exposures at individual- and group-levels. While hierarchical models are often assumed, many populations do not have a nested data structure. Analysts can employ cross-classified models to allow for non-hierarchical, multilevel data. Researchers can evaluate whether random components are necessary and compare goodness of fit statistics to select a parsimonious model.Using cross-classified multilevel models we analyzed the association of birth weight with family and community SES while adjusting for numerous potential confounders. The flexibility of cross-classified models allowed us to sample more than one child per family and to include families who moved between births. Results from a restricted to individual-level variables generally found on birth records, showed an association of birth weight with community SES. When we adjusted for a more complete set of individual- and family-level covariates, community SES was not as important. Residual confounding may explain some results previously reported between community SES and birth weight.The authors declare that they have no competing interests.RLY reviewed prior literature, performed statistical analyses, drafted and revised the manuscript, and has approved the final version for submission to this journal. JW, VV, AA, and TFW participated in study design and variable selection, made significant revisions and contributions to the manuscript, and approved the final version for submission to this journal.An additional file including general SAS code to illustrate how cross-classified models can be applied using standard statistical software is included.Click here for file


An infective, mostly viral basis has been found in different human cancers. To test the hypothesis of a possible infectious aetiology for central nervous system (CNS) tumours in children, we investigated the associations with proxy measures of exposure to infectious disease.In a large case–control study nested in the populations of Denmark, Norway, Sweden, and Finland of 4.4 million children, we studied the association of birth order and seasonal variation of birth with subsequent risk for CNS tumours. We identified 3983 children from the national cancer registries, and information on exposure was obtained from the high-quality national administrative health registries. We investigated the association between childcare attendance during the first 2 years of life and the risk for CNS tumours in a subset of Danish children with CNS tumours, using information from the Danish Childcare database.vs first born, 1.03; 95% confidence interval (CI), 0.96–1.10) or by histological subgroup, and children with CNS tumours did not show a seasonal variation of birth that was distinct from that of the background population. Childcare attendance compared with homecare showed a slightly increased OR  for CNS tumours, with the highest risk observed in children attending a crèche. The strongest association was observed for embryonal CNS tumours. We found no effect of age at enrolment or duration of enrolment in childcare.We observed no association between birth order and risk of CNS tumours overall (odds ratio (OR) for second born or later born These results do not support the hypothesis that the burden of exposure to infectious disease in early childhood has an important role in the aetiology of paediatric CNS tumours. Knowledge about the aetiology of central nervous system (CNS) tumours in children is sparse; however, several studies indicate that the pathogenic process of CNS tumours in children is initiated prenatally , sex, and country to five controls, identified randomly from the Nordic childhood population. Controls were identified from the national population registries, they had to be alive, should have had no previous diagnosis of childhood solid tumour, and had to be living in the respective country at the time of diagnosis of the corresponding case. Birth order was obtained by identifying all maternal siblings in the population registries. We were able to obtain birth order for 3600 cases and 17 848 matching controls; in 43 cases, we were unable to identify the mother, and in Finland, we had information only on children born after 1986. Birth weight and gestational age were obtained from the Danish Medical Birth Registry  and 95% confidence intervals (CIs). Analyses were performed using the LOGISTIC procedure in SAS (version 9.1) . Thus, by retaining the individual matching, we accounted for country, sex, and age in the analyses.Walter and Elwood's test for a sinusoidal variation was applied to evaluate changes in CNS tumour incidence by month of birth, adjusted for the distribution of birth in the reference population . The stuP=0.3)  . FurtherInformation on childcare attendance during the first 2 years of life was complete for 170 cases and 1601 matched controls . We founWe evaluated the effect of childcare in relation to sex, age at diagnosis, preterm birth, and birth order in restricted analysis (data not shown). No differences of the effects of attending childcare were observed between first born and later born children. In addition, we did not see any variation by age at diagnosis or sex. Restricting the data set to children born at term did not change the estimate (data not shown); however, few of the children in the study were born preterm.In this study, the investigated proxy measures of infectious diseases were only weakly associated with CNS tumours in children, if at all. We found strong evidence that birth order has at the most a very small association with CNS tumours, consistent with most previous studies .Birth order may be a particularly poor proxy for exposure to childhood infections in Nordic countries, where a large proportion of children attend childcare (We observed no seasonal variation of birth among children with any kind of CNS tumours in the Nordic countries. Hence, we did not confirm our previous observation of a seasonal variation of birth among children with ependymoma in Denmark , or it mSeasonal variation in births of patients diagnosed with a specific disease, which differs from the underlying seasonality of births in the general population, suggests an environmental factor operating at conception, during pregnancy, in the neonatal period, or later in childhood. Such a seasonal pattern may reflect, for example, variation in exposure to sunlight or to infections. Most previous studies found no seasonal variation of birth among children with CNS tumour overall (Our finding of a small nonsignificant increase in risk associated with childcare attendance should be interpreted carefully, as the numbers are small, resulting in wide CIs of the effect estimates. Furthermore, the lack of a dose–response relationship makes a biological phenomenon less likely. For embryonal CNS tumours, however, the direction of the estimates is more consistent, and this finding should be explored further in larger studies. In contrast to our findings, previous studies suggested a small protective effect of early social contact and childcare attendance (The design and size of our study give high credibility to the results. The Nordic national health registries contain mandatory, continuously updated information on vital status, emigration status, birth, and cancer, and all patients have equal, free access to health care. Thus, use of these virtually complete population registries established for administrative purposes years before the current hypothesis was tested makes the probability of selection bias and information bias negligible.Childhood CNS tumours comprise a heterogeneous group (Overall, the results do not support the hypothesis that exposure to infections in early childhood has a strong role in the pathogenesis of CNS tumours in children. However, we cannot rule out the possibility that a specific infectious agent is involved in the aetiology of CNS tumours.


Caenorhabditis elegans, it is hypothesized that similar genetic mechanisms control the development of these forms. In the parasite Strongyloides stercoralis, FKTF-1 is an ortholog of DAF-16, a forkhead transcription factor that regulates dauer larval development in C. elegans. Using transgenesis, we investigated the role of FKTF-1 in S. stercoralis' infective larval development. In first-stage larvae, GFP-tagged recombinant FKTF-1b localizes to the pharynx and hypodermis, tissues remodeled in infective larvae. Activating and inactivating mutations at predicted AKT phosphorylation sites on FKTF-1b give constitutive cytoplasmic and nuclear localization of the protein, respectively, indicating that its post-translational regulation is similar to other FOXO-class transcription factors. Mutant constructs designed to interfere with endogenous FKTF-1b function altered the intestinal and pharyngeal development of the larvae and resulted in some transgenic larvae failing to arrest in the infective stage. Our findings indicate that FKTF-1b is required for proper morphogenesis of S. stercoralis infective larvae and support the overall hypothesis of similar regulation of dauer development in C. elegans and the formation of infective larvae in parasitic nematodes.Based on metabolic and morphological similarities between infective third-stage larvae of parasitic nematodes and dauer larvae of  Caenorhabditis elegans. Our lab studies the development of the human nematode parasite Strongyloides stercoralis. We identified S. stercoralis' FKTF-1 as an ortholog of DAF-16, a forkhead transcription factor controlling dauer larval development in C. elegans. Transgenes were introduced into S. stercoralis to investigate the possibility that FKTF-1 regulates development of its infective larvae. We discovered that recombinant FKTF-1b tagged with GFP localizes to specific tissues remodeled in infective larvae. Furthermore, mutant forms of FKTF-1b designed to interfere with endogenous FKTF-1b function resulted in incomplete development of the infective larval structures and prevented some transgenic larvae from arresting in the infective stage. Indicating that FKTF-1b is required for the proper development of Strongyloides stercoralis infective larvae, our findings support the hypothesis of similar controls over parasitic and free-living nematode development and pave the way for further comparative studies.Parasitic nematodes are an important threat to public health in much of the world. Understanding how these worms find and invade their hosts may lead to improved therapies. The infectious forms of many parasitic nematodes developmentally arrest as infective third-stage larvae that require hosts to reactivate. Development of these larvae has been compared to that of the diapausing dauer larvae of  Caenorhabditis elegans, this signaling pathway mediates entry into the dauer larvae diapause by negatively regulating DAF-16, a forkhead transcription factor type O (FOXO) C. elegans dauer larvae include increased resistance to stress and a metabolism altered to allow the animal to persist, potentially for months, in unfavorable environments S. stercoralis, have similar requirements for survival prior to host finding. The ‘dauer hypothesis’ recognizes the common physiological characteristics of dauer larvae and parasitic infective larvae, and proposes that the same molecular genetic mechanisms control the morphogenesis of both forms Parasitism among nematodes appears to have arisen multiple times throughout evolution Strongyloides and Parastrongyloides spp., unusual among the parasitic nematodes, alternate between free-living and parasitic generations S. stercoralis females typically develop into free-living adults unless triggered by genetic, environmental or host-associated conditions to develop directly into infective third-stage larvae (L3i) S. stercoralis are uniformly fated to become L3i that invade the host and develop into parasitic females. Previous work identified the FOXO encoding gene fktf-1 (forkhead transcription factor-1) as the ortholog of C. elegans daf-16 in S. stercoralisC. elegans daf-2;daf-16 double mutants fktf-1b encodes a working forkhead transcription factor that can function in insulin-like signaling to regulate L3 development in C. elegans.The life cycles of S. stercoralis itself can now be addressed using new methods for transgenesis in this parasite S. stercoralis with constructs encoding a 2.6 kb fktf-1β promoter controlling expression of GFP::FKTF-1b fusion proteins. We then examined first-stage larval progeny of these female worms for anatomical and intra-cellular localization of GFP-linked proteins and for phenotypes associated with expression of transgenes encoding mutant forms of FKTF-1b.The more relevant question of whether FKTF-1b regulates infective larval development in fktf-1β expression in S. stercoralis mimics that of C. elegans daf-16β, which is expressed primarily in the pharynx and body neurons S. stercoralis larvae expressed fktf-1β::gfp::fktf-1b   exhibited significant (P<0.01) growth retardation at 24 hours , it does not exist in the natural life cycle of S. stercoralisWith regard to the dauer hypothesis and the role of insulin signaling in infective larval development, the most significant results in the present study were the morphogenetic changes seen in L3 expressing the GFP::FKTF-1b(dominant-negative) transgene. Under the null hypothesis, all of our transgenic larvae should develop to L3i. While L3i expressing the wild-type GFP::FKTF-1b fusion protein were morphologically identical to their non-transgenic counterparts , L3 exprFive of the 11 transgenic L3 expressing the dominant-negative construct exhibited changes consistent with a failure to remodel the free-living intestine into the darkened, radially constricted intestine of the L3i. In some cases, the L3 intestine retained bacteria  and in oStrongyloides stercoralis in a manner similar to the dauer regulatory functions of DAF-16 in Caenorhabditis elegans. Furthermore, in this study, we have demonstrated the utility of transgenesis in S. stercoralis for investigation not only of temporal and spatial patterns of gene expression, but also of endogenous gene function. This work opens new avenues of inquiry into the genes involved in the shift between free-living and parasitic states in Strongyloides stercoralis and ultimately into the evolution of parasitism in nematodes generally.Our findings support the ‘dauer hypothesis’ Strongyloides stercoralis was maintained in immuno-suppressed dogs and cultured as described S. stercoralis were isolated from two-day-old coprocultures via Baermann funnels. The worms were washed twice with sterile deionized water to reduce carryover of fecal bacteria and plated on Nematode Growth Medium (NGM agar) plates seeded with Escherichia coli OP50. All cultures of S. stercoralis were incubated at 22°C unless otherwise noted.The UPD strain of C. elegans, the promoter for splice form daf-16b exists in the large intron between exons 4 and 5 fktf-1 genomic sequence also includes a large, approximately 6 kb, intron between the end of the fktf-1a-specific exons (exons 1–3) and the beginning of the fktf-1b-specific exon 4 fktf-1b-specific ATG codon plus the first 90 bp of the coding sequence as the fktf-1β promoter element. Using the primers SsHindBprF1 and SsBprPstR2 ::era-1). The cDNA sequence for fktf-1b had been previously cloned into a plasmid vector pPV207. The coding region of fktf-1b was amplified from pPV207 using the primers: BspE-FkBF  , to remove the terminator for the EF and R . The clospE-FkBF  and FkB-spE-FkBF  and inse::era-1) .fktf-1b in the pCR-BluntII-TOPO cloning vector  to improve the efficiency of the reactions. The phosphorylation-null construct was created in three stages, each stage mutating the key regulatory residues in one of the three functional domains. Primers FK-1bPsite1F2  coding region was cloned in using BspEI and AvrII sites using standard techniques. The phospho-null construct was designated pPV243 (fktf-1β::gfp::fktf-1b(4A)::era-1) . All phosphorylation-null mutagenesis reactions were carried out on the cDNA sequence of Psite1F2  and FK-1Psite1F2  mutated Psite1F2  mutated Psite1F2  mutated ::era-1) .fktf-1β::gfp::fktf-1b(S238E/T240E)::era-1) (Phosphorylation-mimetic primers FkB S238E&T240E F and FkB S238E&T240E R  mutated ::era-1) .The phospho-null construct, GFP::FKTF-1b(4A), which sequesters in the nucleus, still contains functional forkhead (DNA binding) domain and C-terminal transactivation domains and thus should out compete endogenous FKTF-1b for DNA binding sites. Truncation of the C-terminal domain in the phospho-null GFP::FKTF-1b, should create a protein constitutively bound to DNA but unable to activate transcription. Subsequently, replacing the endogenous transactivation domain of FKTF-1b with a repressor domain should create a protein actively repressing transcription specific to FKTF-1b's DNA binding domain.fktf-1b(4A) in the pCR-BluntII-TOPO vector  was again used for mutagenesis using the primers FKTFtrcMutCla1F and FkMutTrcCla R2  coding region -ClaI).The transactivation domain was truncated using an introduced ClaI site immediately downstream of the regulatory phosphorylation site S317. The phospho-null rcCla R2  to introC. elegans gene pie-1 was amplified from RNA prepared from a pool of C. elegans N2 worms using the primers Ce-pie-1ATGF and Ce-pie-1StopR . The resulting PCR product was digested with ClaI and AvrII for cloning, (ClaI-pieCTD-AvrII).The coding region for the e-1StopR  and clon1teravrR  the reprfktf-1b coding region. The ligation reaction included the digested pPV234 vector, the BspEI-fktf-1b-ClaI and the ClaI-pie-1CTD-AvrII simultaneously. The resulting construct, pPV251 ::pie-1CTD::era-1), incorporated gfp upstream of the mutated and truncated fktf-1b region, which became fused to the pie-1CTD ::era-1)  using standard methods and blunt-end ligated.pPV234 was digested with BspEI and AvrII to remove the wild-type pie-1CTD . The dom::era-1) , was creS. stercoralis were transformed with transgene encoding plasmids via intra-gonadal microinjection using standard protocols Adult female S. stercoralis larvae made it impractical to accumulate sufficient numbers of individuals for both phenotypic study . Current methods only allow us to observe transgene expression in F1 generation following transformation.For general expression patterns, plates were scored at 24 hour intervals for adult survival and frequency of transgene expression among F1 progeny. For specific time points, adults were transferred to clean NGM OP50 plates at three to five hour intervals to obtain egg cohorts. All plates with eggs were checked at hourly intervals for the presence of transgenic progeny. When the time of hatch was known, transgenic larvae were transferred to clean plates marked with the time point and examined after the appropriate interval. Transgenic progeny for which the time of hatch was not known were used for analysis of L3i development. The low transformation rate, <5%, of Transgenic larvae were identified based on GFP fluorescence using an Olympus SZX12 stereomicroscope with coaxial epifluorescence. For more detailed examination of particular tissues and individual cells, larvae were immobilized on 4% Agar Noble  pads in 10 mM (L1) or 20 mM (L3i) levamisole and observed using an Olympus BX60 compound microscope equipped with Nomarski Differential Interference Contrast (DIC) optics and epifluorescence . Specimens were imaged with a Spot RT Color digital camera and images were processed using either the Spot Advanced image analysis software package  or Adobe Photoshop 7.0. All image-processing algorithms (e.g. brightness and contrast adjustments) were applied in a linear fashion to the entire image.http://rsb.info.nih.gov/ij/) Worm lengths were measured using the ImageJ program available from the National Institutes of Health  fusion protein expression vector. pPV243 (GFP::FKTF-1b(4A)) has all four canonical Akt/PKB phosphorylation sites mutated to alanine. pPV244 (GFP::FKTF-1b(S238E/T240E) has the phosphorylation sites in the forkhead domain changed to the phospho-mimetic glutamic acid. pPV251 (GFP::FKTF-1b(dom-rep)) and pPV298 (GFP::FKTF-1b(dom-neg)) both contain the four alanine mutations. pPV251 encodes a chimeric fktf-1b with the repressor domain from Ce-pie-1 replacing the endogenous transactivation domain. pPV298 is truncated just downstream of the fourth regulatory phosphorylation site and thus lacks either a transactivation or a repressor domain.Diagrams of (0.63 MB TIF)Click here for additional data file.Figure S2S. stercoralis L1 at 1 hour post-hatch. DIC and fluorescence images of S. stercoralis larvae. Each DIC image is a separate individual. All scale bars = 10 µm. (A–D) 1-hour-old transgenic hatchlings exhibit similar morphology to the non-transgenic hatchling. (E–G) The fusion protein transgenes have similar levels of expression throughout the larvae. (H–K) Intestinal cells of the 1-hour post-hatch larvae were examined for presence or absence of granules using the primordial gonad (arrow) as a landmark. All larvae, wild-type and transgenic, show healthy looking cells with little granularity at this early timepoint. The similar morphologies of the larvae at 1 hour post-hatch indicate apparently normal embryogenesis of transgenic larvae.Transgenic (3.25 MB TIF)Click here for additional data file.Figure S3Strongyloides stercoralis wild-type L3i. (A) DIC image of wild-type L3i showing filariform pharynx, pharynx-intestinal junction (black triangle), and constricted, dark intestine. Scale bar = 20 µm. (B) Anterior half of L3i pharynx showing constricted cylindrical structure characteristic of the filariform pharynx. Scale bar = 10 µm. (C) Pharynx-intestinal junction (black triangle) of an L3i. Note the lack of a grinder-like structure at the base of the pharynx and the closed intestine to the left of the junction. Scale bar = 10 µm. Each image is a separate individual.Examples of (3.95 MB TIF)Click here for additional data file.Table S1Primer sequences used in construct creation.(0.06 MB DOC)Click here for additional data file.Table S2Wild-type and transgenic larvae examined for developmental abnormalities. Images of larvae at 1 hour, 24 hours, and L3i timepoints were examined for intestinal structure abnormalities, pharyngeal abnormalities, presence of storage granules in intestinal cells, and overall body integrity. Intestinal structure abnormalities were defined as atrophy of the intestine or structural defects. Pharyngeal abnormalities included loss of musculature, terminal bulb irregularities, and loss of synchronized contractions. The larva was positive for granules if the majority of intestinal cells near the primordial gonad contained granules. Overall body damage takes into account loss of cells outside of the intestine, damaged tail architecture, and any structural abnormality other than in the intestine and pharynx.(1.12 MB TIF)Click here for additional data file.


Recurrence after surgical treatment of hydatid cyst of the spine is extremely common. Preexisting fibrosis, fragility of the cyst wall, confluent cysts and proximity to vital structures makes radical excision difficult and repeated recurrences are inevitable. This case report describes a recurrent hydatid cyst presenting as three separate cysts in the dorsal spine in a middle-aged male. The extradural cyst caused paraplegia. The extraspinal cyst presented as an extrapleural mass in relation with the eighth, ninth and the tenth ribs near the costo-vertebral junction. The three cysts were resected en masse. Complete neurological recovery occurred with no recurrence at four years follow-up. Resection of the hydatid cyst en masse offers the best chance of cure and must be attempted in all cases. A prolonged chemotherapy should be administered in all cases. Recurrent spinal hydatid disease causing cord compression is a rare occurrence. Multiple surgeries in such situations are associated with a high rate of mortality. Treatment of recurrent lesions is controversial. En masse excision of the lesion wherever possible, is the only way of achieving a lasting cure. The exact role of chemotherapy is unclear.A 48-year-old male presented with progressively worsening pain in the thoracic spine radiating along the right eighth rib of four weeks duration and spastic paraplegia with bladder involvement of two weeks duration. He had undergone intralesional curettage for a progressively enlarging mass in the right eighth rib two years ago. The patient had received anti-echinococcus chemotherapy for six months. The radiographs revealed a residual cyst in the eighth rib with intrathoracic extension . The verUsing a right-sided posterior paramedian curvilinear incision , a myocuThe patient reached full functional status by six months and received albendazole for 12 months. Rod loosening was noticed after four years which was removed subsequently. Alignment of the thoracic spine was maintained and did not show any signs of collapse on follow-up radiographs. Magnetic resonance imaging (MRI) done at four years showed resolution of the cyst .Spinal hydatidosis accounts for 50% of all musculoskeletal hydatid infections.248Pain results from a compressive radiculopathy or due to erosion of the vertebral corpus. Spinal compression causing slowly progressive myelopathy is seen in three situations in decreasing order of frequency: 1. Contiguous spread of an intrathoracic or a retropleural cyst through the neural foramen into the spinal canal. 2. Epidural spread of an anterior osseous cyst and 3. A discreet epidural or an intradural cyst.898The three most widely used drugs are albendazole, mebendazole and praziquantel. Effectiveness of these agents, both in terms of the dose and duration of treatment and role of combination therapy is controversial. Albendazole has better intestinal absorption, a longer half life of 8.5 h and a higher cyst concentration than the other drugs.13It is unclear whether lesions that may be amenable for radical surgery should be treated medically. Benign slow-growing asymptomatic lesions are best treated medically rather than risking an inadvertent surgical rupture, unless these lesions are in close proximity to the spinal cord. In recurrent infiltrative lesions, it is probably wise to combine protracted chemotherapy with punctuated palliative surgeries aimed to improve the quality of life of the patient.There are no criteria on MRI to differentiate between an infectious and a non-infectious treated cyst if the latter does not completely resolve.12


Metronidazole is used to treat trichomoniasis, bacterial vaginosis, and other diseases. As is the case with many drugs, physicians often hesitate to use it during pregnancy, particularly in the first trimester. A review of the nearly four decades' worth of published literature on metronidazole use in pregnant women indicates that it is not teratogenic, regardless of the trimester in which it is used. On the other hand, a number of published studies indicate that bacterial vaginosis and trichomoniasis are associated with preterm birth and low birth weight. Treatment of these conditions with metronidazole during pregnancy may decrease the incidence of preterm birth and low birth weight, thus potentially decreasing the complications that can result from prematurity.