bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fetal Programming and the Leningrad Siege Study
Authors: Stanner Sara A. , Yudkin John S. 
Published: May 2007

AbstractThe Leningrad Siege Study investigated the relationship between decreased maternal food intake and risk factors for coronary heart disease in adult life. The study screened 169 subjects exposed to intrauterine starvation during the Siege of Leningrad (now St Petersburg) 1941–4, 192 subjects born in Leningrad before the siege and 188 subjects born concurrently with these two groups but outside the area of the siege. No difference was found between the subjects exposed to starvation in utero and during infancy in glucose tolerance [in utero: 5.2 mmol/l (95% confidence interval 5.1 to 5.3; infancy: 5.3 (5.1 to 5.5), p = 0.94], insulin concentration, blood pressure, lipid concentration or coagulation factors. The intrauterine exposed group had evidence of endothelial dysfunction by higher concentrations of von Willebrand factor and a stronger interaction between adult obesity and blood pressure. Non-systematic differences in subscapular to triceps skinfold ratio, diastolic blood pressure and clotting factors were demonstrated compared to the non-exposed groups. In conclusion, this study did not find an association between intrauterine starvation and glucose intolerance, dyslipidaemia, hypertension or cardiovascular disease in adult life. These findings differ from studies of subjects exposed to maternal starvation during the Dutch Hunger Winter. However, the dissimilar effects of exposure to the two famines may contribute to our understanding of the mechanisms of the ‘thrifty phenotype’ and support the importance of catch-up growth during early childhood, a situation that occurred in the Netherlands but not in Leningrad.
Effects of Prenatal Exposure to the Dutch Famine on Adult Disease in Later Life: An Overview
Authors: Roseboom Tessa J. , van der Meulen Jan H.P. , Ravelli Anita C.J. , Osmond Clive , Barker David J.P. , Bleker Otto P. 
Published: May 2007

AbstractPeople who were small at birth have been shown to have an increased risk of CHD and chronic bronchitis in later life. These findings have led to the fetal origins hypothesis that proposes that the fetus adapts to a limited supply of nutrients, and in doing so it permanently alters its physiology and metabolism, which could increase its risk of disease in later life. The Dutch famine — though a historical disaster — provides a unique opportunity to study effects of undernutrition during gestation in humans. People who had been exposed to famine in late or mid gestation had reduced glucose tolerance. Whereas people exposed to famine in early gestation had a more atherogenic lipid profile, somewhat higher fibrinogen concentrations and reduced plasma concentrations of factor VII, a higher BMI and they appeared to have a higher risk of CHD. Though the latter was based on small numbers, as could be expected from the relatively young age of the cohort. Nevertheless, this is the first evidence in humans that maternal undernutrition during gestation is linked with the risk of CHD in later life. Our findings broadly support the hypothesis that chronic diseases originate through adaptations made by the fetus in response to undernutrition. The long-term effects of intrauterine undernutrition, however, depend upon its timing during gestation and on the tissues and systems undergoing critical periods of development at that time. Furthermore, our findings suggest that maternal malnutrition during gestation may permanently affect adult health without affecting the size of the baby at birth. This gives the fetal origins hypothesis a new dimension. It may imply that adaptations that enable the fetus to continue to grow may nevertheless have adverse consequences for health in later life. CHD may be viewed as the price paid for successful adaptations to an adverse intra-uterine environment. It also implies that the long-term consequences of improved nutrition of pregnant women will be underestimated if these are solely based on the size of the baby at birth. We need to know more about what an adequate diet for pregnant women might be. In general, women are especially receptive to advice about diet and lifestyle before and during a pregnancy. This should be exploited to improve the health of future generations.
Cardiovascular Mortality in Twins and the Fetal Origins Hypothesis
Authors: Christensen Kaare , Wienke Andreas , Skytthe Axel , Holm Niels V. , Vaupel James W. , Yashin Anatoli I. 
Published: May 2007

AbstractThe intrauterine growth patterns for twins are characterized by normal development during the first two trimesters and reduced growth during the third trimester. According to the fetal origins hypothesis this growth pattern is associated with risk factors for cardiovascular morbidity and mortality. We studied cause-specific mortality of 19,986 Danish twin individuals from the birth cohorts 1870–1930 followed from 1952 through 1993. Despite the large sample size and follow-up period we were not able to detect any difference between twins and the general population with regard to all-cause mortality or cardiovascular mortality. Hence, the intrauterine growth retardation experienced by twins does not result in any “fetal programming” of cardiovascular diseases. There is still an important role for twins (and other sibs) to play in the testing of the fetal origins hypothesis, namely in studies of intra-pair differences, which can assess the role of genetic confounding in the association between fetal growth and later health outcome.
Early Changes in Vascular Dynamics in Relation to Twin-Twin Transfusion Syndrome
Authors: Gardiner Helena M. 
Published: May 2007

AbstractAclearer understanding of the early determinants of normal and abnormal vascular development is pivotal in order to identify those at increased risk of later vascular disease, and perhaps to prevent it by early intervention. Measurement of pulse wave velocity(PWV) has been used in the postnatal evaluation of the monochorionic(MC) twins. They are genetically identical and those with twin-twin transfusion syndrome(TTTS) provide an ideal natural model in whom to study the influence of differing haemodynamic stresses on the developing vascular tree. We investigated firstly whether surviving twin pairs with TTTS have altered arterial distensibility in childhood by comparing PWV in the radial arteries of surviving MC twin pairs with TTTS and in two control groups, one cohort of MC twins without TTTS and another dichorionic group (DC) Secondly, we tested a cohort of TTTS twin pair survivors treated with laser photocoagulation. The co-twin pairs in the group managed palliatively with amnioreduction showed increased PWV in the donor and reduced PWV in the recipient twins. This was neither seen in the laser-treated, nor in the control groups. Our studies suggest that a period of haemodynamic imbalance gives rise to changes in a muscular conduit artery that persist at least into infancy and it seems that by correcting the abnormal haemodynamics relatively soon after the disease process had begun, the alterations in elasticity are prevented. These studies are the first to demonstrate fetal programming of the vascular bed in humans, and prevention or reversal of this programming by an intervention in mid-gestation.
Comparing Blood Pressure of Twins and Their Singleton Siblings: Being a Twin Does Not Affect Adult Blood Pressure
Authors: de Geus Eco J.C. , Posthuma Danielle , IJzerman Richard G. , Boomsma Dorret I. 
Published: May 2007

AbstractThe hypothesis was tested that monozygotic (MZ) and dizygotic (DZ) twins, with their lower average birth weight, have higher adult blood pressure than their singleton brothers or sisters. From the Netherlands Twin Registry, 261 twin families were recruited from a young adult and an older adult cohort with mean ages of 26.2 and 50.4 respectively. These families yielded 204 MZ twins with 71 singleton siblings and 271 DZ twins with 103 of their singleton siblings. Anti-hypertensive medication use of these 649 participants was assessed twice with a two-year interval. Resting blood pressure was measured thrice during a standardized laboratory protocol. In spite of a significant difference in birth weight (1036 gram), no differences were found in anti-hypertensive medication use at both time points between twins and singletons nor between their resting laboratory diastolic or systolic blood pressure. These results applied to each gender and to both age cohorts. Limiting the analyses to matched twin-sibling pairs of the same families and taking current weight and height into account did not change the results; no evidence was found for a twin-singleton difference. It was concluded that estimates of genetic and environmental contributions to blood pressure deriving from twin studies do not appear to be biased and may be generalized to singletons. Our results suggest that the lower birth weight in twins does not reflect the intrauterine disadvantage described by the Barker hypothesis.
Health of Human and Livestock Conceived by Assisted Reproduction
Authors: Ceelen Manon , Vermeiden Jan P.W. 
Published: May 2007

AbstractAssisted reproduction is used to resolve infertility problems in human and in breeding programs to generate livestock. Except for gestation length and birth weight, perinatal outcome of children conceived by In Vitro Fertilization is similar to that of spontaneously conceived children. However, large offspring syndrome observed after In Vitro Production in livestock is quite alarming. The distinct parts of assisted reproduction (oocyte maturation, fertilization and culture) have been found to contribute to abnormal fetal growth and development. Genomic imprinting is suggested to be involved in the induction of the aberrant phenotypes observed after assisted reproduction. Furthermore, current knowledge on postnatal health of offspring conceived by assisted reproduction and speculations on potential longterm effects of In Vitro Fertilization will be described.
The Effects of Assisted Reproduction on the Trends and Zygosity of Multiple Births in England and Wales 1974–99
Authors: Platt Mary J. , Marshall Amy , Pharoah Peter O.D. 
Published: May 2007

AbstractAssisted reproductive techniques have led to an increase in the proportion of maternities that are multiple. Though predominantly dizygotic, they are at greater risk of monozygotic division than those spontaneously conceived. England and Wales data 1974–99 on stillbirths and livebirths were analysed for 4 periods: 1974–80 (pre-assisted reproduction; 1982–8; 1989–91 (pre-redefinition of stillbirth); 1993–9 (post-redefinition of stillbirth). For twin data, Weinberg's rule was applied to estimate the proportions that were mono- (MZ) and dizygotic (DZ). Compared with the period before assisted reproduction, the most recent period shows an increase in twin maternities of 3.81 per 1000 comprised of 3.22 (95% CI 3.10 to 3.33;p< 0.0001) DZ and 0.60 (95% CI 0.51 to 0.68;p< 0.0001) MZ twins. It is estimated that 15.7% of assisted reproduction twins are MZ. Higher order multiple births showed an increase of 3.06 (95% CI 2.85 to 3.29;p< 0.0001) per 10,000 maternities. Stillbirth rates in MZ twins are of the same order of magnitude as those in higher order multiple births but higher than those in DZ twins. The improvement in stillbirth rates over the 26 year study period is of the same order magnitude in singletons, DZ and MZ twins and higher order multiples. Assisted reproduction has led to a significant increase in the proportion of MZ twins. These are at high risk of fetal death and this needs to be considered when local stillbirth and perinatal mortality rates are used in auditing obstetric services.
Feasibility of Using Different Approaches for Recruiting Younger Twins to Establish a Population Based Twin Register in Sri Lanka
Authors: Sumathipala Athula , Siribaddana Sisira H. , De Silva Nimali , Abeysingha Nihal M. R. , Sivayogam Sivagurunathan , Fernando Devaka J. S. 
Published: May 2007

AbstractIdentifying twins for a population-based register can be achieved through birth records or community surveys. We studied the feasibility and effectiveness of different methods of identifying and recruiting twins to establish a population based register. To trace twins a population survey was carried out using an interviewer administered questionnaire. We also inspected the birth registration certificates at a divisional secretariat reported from a specified hospital between the years of 1985–1997 and compared it to the birth register of this same hospital. To recruit twins a random sample of 75 twin pairs (150 twins) identified at the Divisional Secretariat were contacted through the post and 25 twin pairs (50 twins) were personally visited. The prevalence of twins was 6.5 twins per 1000 people in the area surveyed. The twinning rate at the hospital was 18.92 twins per 1000 births. A discrepancy of 38 multiples births between the hospital labour room records and those registered at the DS was noted. The response from the postal invitation for recruitment was 59% and the response from the personal invitation was 68%. (Difference 9.4% 95% CI; 7.06–11.73). Community survey and systematic inspection of birth records either at the hospital or the birth registration office was an effective method to trace twins. Once traced, personal contact was more effective than the postal invitation for recruitment of younger twins. A cost-effective approach would be to use a postal coverage followed by personal contact for non-responders. The alternative method, community coverage, would have financial implications.
Are Twins and Singletons Comparable? A Study of Disease-related and Lifestyle Characteristics in Adult Women
Authors: Andrew Toby , Hart Deborah J. , Snieder Harold , de Lange Marlies , Spector Tim D. , MacGregor Alex J. 
Published: May 2007

AbstractThe classic twin study is sometimes described as “the perfect natural experiment” for the investigation of the aetiology of complex disease, but assumptions of the twin design need to be empirically tested if their results are to be considered unbiased and representative of singleton populations. In this study comparisons of disease and prevalence of lifestyle characteristics have been made between twin participants in the St Thomas' Hospital UK adult twin registry, the largest twin volunteer register in the UK for the study of diseases of ageing, and a parallel population-based study of singleton women. The only differences found were for weight, where monozygotic (MZ) twins were lighter and had a smaller variance than dizygotic (DZ) twins and singletons. For the other variables studied, volunteer twins were not found to differ from age-matched singleton women in distribution or prevalence of: bone mineral density, osteoarthritis, blood pressure, hypertensive drug use, height, history of hysterectomy and ovariectomy, menopausal status and current alcohol and overall tobacco consumption. We conclude that the results of twin studies can be generalised to singleton populations for these measures and disease outcomes.
Uprighting Partially Impacted Permanent Second Molars
Authors: Sawicka Monika , Racka-Pilszak Bogna , Rosnowska-Mazurkiewicz Anna 
Published: May 2007

AbstractImpaction of the lower second molar is not a common problem, but it is very challenging for both orthodontist and oral surgeon. Treatment options depend on the degree of tooth inclination, the position of the third molars, and the desired type of movement, which may be surgical and/or orthodontic in nature. A good treatment alternative is surgical uncovering with orthodontically-assisted eruption. A case of successful uprighting using a 0.017 × 0.025–inch titanium molybdenum alloy (TMA) tip-back cantilever is presented. Different aspects of uprighting impacted second molars are discussed in light of the literature. The iatrogenic character of lower second molar impaction is emphasized.
Shear Bond Strength Comparison between Two Orthodontic Adhesives and Self-Ligating and Conventional Brackets
Authors: Northrup Rodney G. , Berzins David W. , Bradley Thomas Gerard , Schuckit William 
Published: May 2007

Abstract
Objective: To evaluate and compare the shear bond strengths of two adhesives using two types of brackets: a conventional and a self-ligating bracket system.
Materials and Methods: Sixty extracted human premolars were collected. The premolars were randomly divided into three groups of 20 teeth. All three groups were direct bonded. Groups 1 and 2 used light-cured adhesive and primer (Transbond XT) with a conventional (Orthos) and a self-ligating bracket (Damon 2), respectively. Group 3 used a light-cured primer (Orthosolo) and a light-cured adhesive (Blūgloo) with a self-ligating bracket (Damon 2). The specimens were stored in distilled water at 37°C for 40 ± 2 hours, after which they were debonded and inspected for Adhesive Remnant Index (ARI) scoring.
Results: The mean shear bond strength was 15.2 MPa for group 1, 23.2 MPa for group 2, and 24.8 MPa for group 3. A one-way analysis of variance and post hoc Tukey test showed significant differences in bond strength (P &lt; .001) between group 1 and groups 2 and 3 but no significant difference (P &gt; .05) between groups 2 and 3. A Weibull analysis demonstrated that all three groups provided sufficient bond strength with over 90% survival rate at normal masticatory and orthodontic force levels. A Kruskal-Wallis test showed no significant difference (P &gt; .05) in ARI scores among all three groups.
Conclusions: All three groups demonstrated clinically acceptable bond strength. The Damon 2 self-ligating bracket exhibited satisfactory in vitro bond strength with both adhesive systems used.
Long-Term Stability of Surgical Mandibular Setback
Authors: Cho Heon Jae 
Published: May 2007

Abstract
Objective: To test the relationship between positional changes of the proximal segments during surgery and the positional rebound of the mandible during the postsurgical period of orthodontic treatment.
Materials and Methods: The sample included records for 34 patients who had received sagittal split surgery for the correction of mandibular prognathism. Data were collected from standardized cephalometric radiographs taken immediately prior to surgery (T2), immediately following surgery (T3), and following the completion of orthodontic treatment (T4). Linear and angular changes in the orientation of the posterior border of the ascending ramus between time points T2, T3, and T4 were measured relative to superimposition on the anterior cranial base. In addition, linear changes in the position of pogonion between T3 and T4 were measured.
Results: The magnitude of linear displacement of the posterior border of the proximal segment during surgery (T2 to T3) was statistically significantly correlated (r = .61) with the magnitude of linear displacement of pogonion during the postsurgical phase of orthodontic treatment (T3 to T4). There was a strong relationship between the magnitude of angular (r = .67) displacement of the posterior border of the proximal segments during surgery (T2 to T3) and the magnitude of angular rebound of the posterior border of the proximal segments that occurred during the postsurgical phase of orthodontic treatment (T3 to T4).
Conclusions: When rigid fixation procedures alter the position of the proximal segments during sagittal split osteotomy of the mandible, the proximal segments tend to go back toward their presurgical positions following surgery.
Cytotoxicity of Two Bonding Adhesives Assessed by Three-Dimensional Cell Culture
Authors: Vande Vannet Bart Maurice Rene Antoine , Hanssens Jean Louis 
Published: May 2007

Abstract
Objective: To determine the toxicity of orthodontic adhesives assessed on in vitro three-dimensional reconstructed human oral epithelium (RHOE).
Materials and Methods: Two adhesive primers, Transbond XT (3M, Monrovia, Calif) and Excite (Vivadent, Schaan, Liechtenstein), were tested. After topical exposure, the cell cultures were fixed, cut, and stained for light microscopy (LM) and transmission electron microscopy (TEM). Detection of cytotoxicity by measuring lactate dehydrogenase (LDH) activity was performed. Toxicity was assessed by evaluating the morphological changes with LM and TEM. Copper wires and Triton X-100 served as positive controls, and native cell cultures as negative control.
Results: Morphological evaluation of the native cell cultures revealed no toxic reactions. The LDH assay revealed the following mean values for viability: native cell line (negative control), 1.51; Triton X-100 (positive control), 3.06; Transbond XT polymerized, 1.15; Excite polymerized, 1.11; Transbond XT primer, 2.67; and Excite primer, 0.04. Acute toxicity was observed for Triton X-100 and Transbond XT primer (P &lt; .001). Histological evaluation of the RHOE showed toxicity for both primers and mild changes after topical application of polymerized adhesives. The biocompatibility ranking of the adhesive primers was the same after histological analysis and LDH assay except for Excite™ noncured.
Conclusions: RHOE proved to be a valuable model for topical exposure. The toxicity of both uncured primers was demonstrated.
Effect of Disinfecting Solutions on the Mechanical Properties of Orthodontic Elastomeric Ligatures
Authors: Evangelista Maylani B. , Berzins David W. , Monaghan Peter 
Published: May 2007

Abstract
Objective: To assess the effect extended exposure to disinfectant solutions has on the tensile load at failure and glass transition temperature (Tg) of orthodontic elastomeric ligatures.
Materials and Methods: Elastomeric ligatures from three manufacturers: Rocky Mountain Orthodontics (RMO, Denver, Colo), American Orthodontics (AO, Sheboygan, Wis), and 3M Unitek (3M, Monrovia, Calif) were exposed to two disinfectant solutions, Vital Defense-D and Cidexplus, for up to 28 days. Unexposed ligatures were also tested. Tensile load at failure was determined by stretching the ligatures using a universal testing machine until they fractured. Glass transition temperature was determined using differential scanning calorimetry (DSC).
Results: For tensile load at failure and glass transition temperature of the ligatures, significant differences were observed among the different manufacturers and exposure times. Type of disinfectant solution was a significant factor with Tg, but not with failure load. The 3M ligatures had the highest tensile load at failure and most positive Tg followed by AO and RMO, respectively. Compared to unexposed ligatures, strength significantly decreased after one hour of disinfectant exposure. Glass transition temperature was also significantly affected with extended disinfectant exposure, but the different disinfectants changed Tg in opposite directions.
Conclusion: Exposure of elastomeric ligatures to disinfectant solution for one hour or more decreases their strength.