Cesarean delivery is associated with an increased risk of obesity in adulthood in a Brazilian birth cohort study

Background: Obesity is epidemic worldwide, and increases in cesarean delivery rates have occurred in parallel. Objective: This study aimed to determine whether cesarean delivery is a risk factor for obesity in adulthood in a birth cohort of Brazilian subjects. Design: We initiated a birth cohort study in Ribeirao Preto, southeastern Brazil, in 1978. A randomly selected sample of 2057 subjects from the original cohort was reassessed in 2002-2004. Type of delivery, birth weight, maternal smoking, and schooling were obtained after birth. The following data from subjects were collected at 23-25 y of age: body mass index (BMI; in kg/m(2)), physical activity, smoking, and income. Obesity was defined as a BMI >= 30. A Poisson multivariable model was performed to determine the association between cesarean delivery and BMI. Results: The obesity rate in adults born by cesarean delivery was 15.2% and in those born by vaginal delivery was 10.4% (P = 0.002). Adults born by cesarean delivery had an increased risk (prevalence ratio: 1.58; 95% CI: 1.23, 2.02) of obesity at adulthood after adjustments. Conclusion: We hypothesize that increasing rates of cesarean delivery may play a role in the obesity epidemic worldwide. Am J Clin Nutr 2011;93:1344-7.

Birth weight and bone mass in young adults from Brazil

Background: Birth weight is positively associated with adult bone mass. However, it is not clear if its effect is already evident in early adulthood. Objective: To investigate the association between birth weight, adult body size, the interaction between them and bone mass in young adults. Methods: Bone densitometry by DXA was performed on 496 individuals (240 men) aged 23-24 years from the 1978/79 Ribeirao Preto (southern Brazil) birth cohort, who were born and still residing in the city in 2002. Birth weight and length as well as adult weight and height were directly measured and converted to z-scores. The influence of birth weight and length, and adult weight and height on bone area (BA), bone mineral content (BMC) and bone mineral density (BMD) at the lumbar spine, proximal femur and femoral neck were investigated through simple and multiple linear regression models. Adjustments were made for sex, skin color, gestational age, physical activity level, smoking status and dietary consumption of protein, calcium and alcohol. Interaction terms between birth weight and adult weight, and birth length and adult height were tested. Results: Men in the highest fertile of birth weight distribution had greater BA and BMC at all three bone sites when compared with their counterparts in the lowest tertiles (p<0.008). For BMD, this trend was observed only in the lumbar spine. Adult weight and height were positively associated with BA and BMC at all three bone sites (p<0.05). For BMD, these associations were seen for adult weight, but for adult height an association was observed only in the lumbar spine. Birth weight retained positive associations with proximal femur BA and BMC after adjustments for current weight and height. No interaction was observed between variables measuring prenatal growth and adult body size. Conclusion: Birth weight and postnatal growth are independent determinants of adult bone mass in a sample of Brazilian adults. This effect is already evident in early adulthood. (C) 2010 Elsevier Inc. All rights reserved.

Adiponectin: serum levels, promoter polymorphism, and associations with birth size and cardiometabolic outcome in young adults born large for gestational age

Objective: To assess whether the -11391G > A polymorphism in the regulatory region of the adiponectin gene (ADIPOQ) is associated with birth size, postnatal growth, adiponectinemia, and cardiometabolic risk in adult life. Design: Case-control study nested within a prospective cohort of 2063 community subjects born in 1978/1979 and followed since birth to date. Methods: ADIPOQ -11391G > A genotype-phenotype associations were evaluated in 116 subjects born large for gestational age (LGA) and 392 gender-matched controls at birth (birth size), at 8-10 years (catch-down growth), and at 23-25 years of age (cardiometabolic profile). Results: The -11391A variant allele frequency was higher in LGA subjects (P=0.04). AA genotype was associated with augmented probability of being born LGA (odds ratio=4.14; 95% confidence interval: 1.16-16.7; P=0.03). This polymorphism was associated neither with body composition nor with postnatal growth pattern. At the age of 23-25 years, the -11391A variant allele was associated with higher serum adiponectin levels (GG: 10.7 +/- 6.2 versus GA: 12.2 +/- 6.5 versus AA: 14.2 +/- 6.8 mu g/ml; P < 0.01). Subjects born LGA presented higher body mass index (BMI; P=0.01), abdominal circumference (P=0.04), blood pressure (P=0.04), and homeostasis assessment model for insulin resistance (P=0.01) than adequate for gestational age. Symmetry at birth did not influence these variables. The occurrence of catch-down of weight was associated with lower BMI and abdominal circumference (P < 0.001) at 23-25 years. Conclusions: The -11391A ADIPOQ gene variant was associated with increased chance of being born LGA and with higher adiponectin levels in early adult life.

The rise of multiple births in Brazil

Aim: The aim of this study was to assess the rise in multiple births and its influence on trends of low birth weight (LBW) rates in Porto Alegre, Brazil. Methods: This is a registry-based study of live births from 1994 to 2005 obtained from the national live birth information system. Chi-square tests for trends were assessed for LBW and multiple birth rates. The impact of multiple births on LBW trends was assessed by sequential modelling, including year and further adjustment for multiple births. Risk factors for multiple births were assessed using the Poisson regression. Results: A total of 263 252 live births were studied. The LBW rate increased from 9.70% to 9.88% (p < 0.001) and the multiple birth rate rose from 1.95% to 2.53% (p < 0.001). LBW rate increased among twins, from 57.14% to 63.46% (p = 0.001). The twin birth rate rose by 24.7%, while the rate of triplets or higher-order increased by 150%. Multiple births may be responsible for 23.9% of the increase in the LBW rate over the period. Mothers with higher levels of schooling, older mothers and mothers delivering in private hospitals were more likely to deliver multiple births. Conclusions: It seems that both the increase in multiple births and in the LBW among multiple births contributed to this rise in overall LBW rate.

Birth Prevalence and Natural History of Congenital Cytomegalovirus Infection in a Highly Seroimmune Population

Background. The natural history of congenital cytomegalovirus (CMV) infection is scarcely known in populations with high maternal CMV seroprevalence. This study evaluated the birth prevalence, clinical findings at birth, and hearing outcome in CMV-infected children from such a population. Methods. Consecutively born infants were screened for the presence of CMV in urine and/or saliva specimens during the first 2 weeks after birth. Neonatal clinical findings were recorded, and CMV-infected children were tested to document hearing function during follow-up. A subset of mothers of CMV-infected infants were prenatally tested for the presence of anti-CMV immunoglobulin G antibodies. Results. Congenital CMV infection was confirmed in 87 (1.08%; 95% confidence interval [CI], 0.86%-1.33%) of 8047 infants. Seven infants (8.1%; 95% CI, 3.3%-15.9%) had at least 1 clinical finding suggestive of CMV infection, and 4 (4.6%; 95% CI, 1.3%-11.3%) had 13 findings of systemic disease. Sensorineural hearing loss was found in 5 (8.6%; 95% CI, 2.9%-19.0%) of 58 children tested at a median age of 21 months. Bilateral profound hearing loss was observed in 2 children, and the hearing threshold was 160 decibels in all 5 children with hearing loss, including 2 children born to mothers with probable nonprimary CMV infection. Conclusions. The results of this large newborn screening study in a population with high CMV seroimmunity provide additional evidence that congenital CMV disease occurs in populations with high seroprevalence rates, with a similar incidence of CMV-related hearing loss to that reported in the offspring of women from populations in developed countries with lower rates of seroimmunity to CMV.

Stereological and allometric studies on neurons and axo-dendritic synapses in the superior cervical ganglia of rats, capybaras and horses

The superior cervical ganglion (SCG) in mammals varies in structure according to developmental age, body size, gender, lateral asymmetry, the size and nuclear content of neurons and the complexity and synaptic coverage of their dendritic trees. In small and medium-sized mammals, neuron number and size increase from birth to adulthood and, in phylogenetic studies, vary with body size. However, recent studies on larger animals suggest that body weight does not, in general, accurately predict neuron number. We have applied design-based stereological tools at the light-microscopic level to assess the volumetric composition of ganglia and to estimate the numbers and sizes of neurons in SCGs from rats, capybaras and horses. Using transmission electron microscopy, we have obtained design-based estimates of the surface coverage of dendrites by postsynaptic apposition zones and model-based estimates of the numbers and sizes of synaptophysin-labelled axo-dendritic synaptic disks. Linear regression analysis of log-transformed data has been undertaken in order to establish the nature of the relationships between numbers and SCG volume (V(scg)). For SCGs (five per species), the allometric relationship for neuron number (N) is N=35,067xV (scg) (0.781) and that for synapses is N=20,095,000xV (scg) (1.328) , the former being a good predictor and the latter a poor predictor of synapse number. Our findings thus reveal the nature of SCG growth in terms of its main ingredients (neurons, neuropil, blood vessels) and show that larger mammals have SCG neurons exhibiting more complex arborizations and greater numbers of axo-dendritic synapses.

Peripartum Haemodynamic Status of Bitches with Normal Birth or Dystocia

There has been limited investigation of parturition in the bitch and there is little information published on clinical and obstetrical examination other than opinion and anecdote. While there are substantial data on haemodynamic and vascular changes during normal parturition in humans, little is known about the physiological events in the dog. This study was aimed at maternal haemodynamic changes occurring during normal parturition and to investigate how these were modified in bitches with dystocia (DYST) treated either medically or via assisted delivery and caesarean operation. Three groups of 10 bitches were investigated; those with normal parturition, those with DYST corrected by manipulative assistance or caesarean operation and those with uterine inertia treated by oxytocin administration. Heart rate, systolic and diastolic blood pressure, electrocardiogram and blood glucose concentration were measured pre-partum, intra-partum, immediately after parturition and 1 h later. Heart rate was high at all times throughout the study and the majority of bitches had normal sinus rhythm. Blood pressure was generally within the normal range, and although systolic and diastolic blood pressure was highest during the intra-partum period and sometimes during the immediate post-partum period, there were no significant differences between groups. All bitches had blood glucose concentrations within the normal range throughout the study although pre-partum concentrations were statistically lower than many of the other time periods. The study provides useful physiological data that will facilitate monitoring and clinical management of bitches throughout normal parturition and DYST.

Neonatal Clinical Evaluation, Blood Gas and Radiographic Assessment After Normal Birth, Vaginal Dystocia or Caesarean Section in Dogs

This study aimed to standardize signs and diagnostic criteria of respiratory function in newborn puppies delivered normally or after dystocia and caesarean operation. A total of 48 neonates were allocated into groups: eutocia (n = 20), dystocia (n = 8), caesarean (c)-section (n = 20). Neonatal health was assessed using the Apgar score and body temperature was determined at 0, 5 and 60 min after delivery. Venous blood gases (pO(2) and SO(2)) was measured immediately and 60 min after delivery, and a thoracic radiograph was made between 0 and 5 min of life. The c-section group had significantly lower Apgar scores at birth and 5 min. Hypothermia was present at 5 min in the eutocia and c-section groups, and at 60 min in all groups. The eutocia group had an irregular respiratory pattern in 78% of puppies at birth, 27.7% at 5 min and 21% at 60 min compared with 87.5%, 62.5% and 12.5% of the pups in the dystocia group where there was irregular respiratory rhythm, moderate to intense respiratory sounds with agonic episodes. The c-section group had respiratory alterations in 70%, 45% and 16% of puppies at 0, 5 and 60 min, respectively. Radiographic abnormalities were present in 17% of the pups in the eutocia group, 25% of the pups in the dystocia group and 30% of the pups in the c-section group, respectively. The c-section group had significantly lower SO(2) values at 60 min than at birth. All puppies had hypoxaemia, but a significant decrease was observed in the c-section group. Newborn puppies had tissue hypoxia and irregular respiratory pattern at birth. Caesarean-section puppies had lower vitality; however, all developed satisfactory Apgar scores at 5 min of life, regardless of the obstetric condition.

Acid-Base Changes in Canine Neonates Following Normal Birth or Dystocia

There are limited data concerning blood gas parameters in neonatal dogs. Knowledge of the normal physiology may facilitate effective therapeutic intervention and potentially reduce neonatal mortality. This study examined acid-base parameters in pups born at normal parturition (n = 27) compared with those born after obstetrical assistance or caesarean operation (n = 13) and those born following oxytocin (OXY) administration for treatment of uterine inertia (n = 11). Pups were subjected to an objective scoring method of neonatal health adapted from use in humans (the Apgar score) at birth and again at 5 and 60 min after birth. Venous blood samples were collected at 5 and 60 min after birth for evaluation of blood gas parameters. At birth, all pups had low Apgar scores and a mixed acidosis. The base excess was lowest for pups delivered after OXY administration. The Apgar score improved for all pups after 5 min of birth and there was an improvement in carbon dioxide tension, base excess and venous blood pH at 1 h, although in all pups a metabolic acidosis persisted. These data provide an important insight into neonatal physiology and the variability of blood gas parameters in pups born at normal and abnormal parturition and provide the basis for clinical decision making following dystocia.

Three-point boundary value problems for second-order, ordinary, differential equations

We establish existence results for solutions to three-point boundary value problems for nonlinear, second-order, ordinary differential equations with nonlinear boundary conditions. (C) 2001 Elsevier Science Ltd. All rights reserved.

Smallest weak and smallest totally weak critical sets in the latin squares of order at most seven

A critical set in a latin square of order n is a set of entries in a latin square which can be embedded in precisely one latin square of order n. Also, if any element of the critical set is deleted, the remaining set can be embedded in more than one latin square of order n. In this paper we find smallest weak and smallest totally weak critical sets for all the latin squares of orders six and seven. Moreover, we computationally prove that there is no (totally) weak critical set in the back circulant latin square of order five and we find a totally weak critical set of size seven in the other main class of latin squares of order five.

Genetic and non-genetic factors affecting birth-weight and adult body mass index

Birthweight affects neonatal mortality and morbidity and has been used as a marker of foetal undernutrition in studies of prenatal effects on adult characteristics. It is potentially influenced by genetic and environmental influences on the mother, and effects of foetal genotype, which is partially derived from the maternal genotype. Interpretations of variation in birthweight and associated characteristics as being due to prenatal environment ignore other possible modes of materno-foetal transmission. Subjects were adult twins recruited through the Australian Twin Registry, aged 17 to 87 years, and the sample comprised 1820 men and 4048 women. Twins reported their own birthweight as part of a health questionnaire. Body Mass Index (BMI) was calculated from self-reports of height and weight. Correlations between co-twins' birthweights were high for both monozygotic (r = 0.77) and dizygotic (r = 0.67) pairs, leading to substantial estimates of shared environmental effects (56% of variance) with significant additive genetic (23%) and non-shared environmental (21%) components. Adult BMI was mainly influenced by genetic factors, both additive (36% of variance) and nonadditive (35%). The correlation between birthweight and BMI was positive, in that heavier babies became on average more obese adults. A bivariate model of birthweight and adult BMI showed significant positive genetic (rg = 0.16, p = 0.005) and environmental (re = 0.08, p = 0.000011) correlations. Intra-uterine environmental or perinatal influences shared by cotwins exercise a strong influence on birthweight, but the factors which affect both birthweight and adult BMI are partly genetic and partly non-shared environmental.

A comparison of low-storage strategies for spectral analysis in dissipative systems: filter diagonalisation in the Lanczos representation and harmonic inversion of the Chebychev-order-domain autocorrelation function

We compare the performance of two different low-storage filter diagonalisation (LSFD) strategies in the calculation of complex resonance energies of the HO2, radical. The first is carried out within a complex-symmetric Lanczos subspace representation [H. Zhang, S.C. Smith, Phys. Chem. Chem. Phys. 3 (2001) 2281]. The second involves harmonic inversion of a real autocorrelation function obtained via a damped Chebychev recursion [V.A. Mandelshtam, H.S. Taylor, J. Chem. Phys. 107 (1997) 6756]. We find that while the Chebychev approach has the advantage of utilizing real algebra in the time-consuming process of generating the vector recursion, the Lanczos, method (using complex vectors) requires fewer iterations, especially for low-energy part of the spectrum. The overall efficiency in calculating resonances for these two methods is comparable for this challenging system. (C) 2001 Elsevier Science B.V. All rights reserved.

Urban birth and migrant status as risk factors for psychosis: An Australian case-control study

Background Urban birth and migrant status have been identified as risk factors for psychosis in North American and European studies. The aim of this study was to explore these variables in an Australian case-control study. Method Country of birth of subjects and their parents, and place of birth of Australian-born subjects, were examined in individuals with psychosis drawn from a prevalence study (n = 310) and well controls recruited from the same catchment area (n = 303). Results Migrant status was associated with a significantly decreased odds of having a psychotic disorder. For those born in Australia, neither migrant status of parents nor urban birth was associated with having a psychotic disorder. Conclusions The lack of effect for urban birth and second-generation migrant status may help generate candidate environmental risk factors that operate in Europe but not in Australia.