Plasma amino acids in pregnancy, placental intervillous space and preterm newborn infants

Plasma amino acid levels have never been studied in the placental intervillous space of preterm gestations. Our objective was to determine the possible relationship between plasma amino acids of maternal venous blood (M), of the placental intervillous space (PIVS) and of the umbilical vein (UV) of preterm newborn infants. Plasma amino acid levels were analyzed by ion-exchange chromatography in M from 14 parturients and in the PIVS and UV of their preterm newborn infants. Mean gestational age was 34 ± 2 weeks, weight = 1827 ± 510 g, and all newborns were considered adequate for gestational age. The mean Apgar score was 8 and 9 at the first and fifth minutes. Plasma amino acid values were significantly lower in M than in PIVS (166%), except for aminobutyric acid. On average, plasma amino acid levels were significantly higher in UV than in M (107%) and were closer to PIVS than to M values, except for cystine and aminobutyric acid (P < 0.05). Comparison of the mean plasma amino acid concentrations in the UV of preterm to those of term newborn infants previously studied by our group showed no significant difference, except for proline (P < 0.05), preterm > term. These data suggest that the mechanisms of active amino acid transport are centralized in the syncytiotrophoblast, with their passage to the fetus being an active bidirectional process with asymmetric efflux. PIVS could be a reserve amino acid space for the protection of the fetal compartment from inadequate maternal amino acid variations.

Racial inequalities and perinatal health in the southeast region of Brazil

Few studies are available about racial inequalities in perinatal health in Brazil and little is known about whether the existing inequality is due to socioeconomic factors or to racial discrimination per se. Data regarding the Ribeirão Preto birth cohort, Brazil, whose mothers were interviewed from June 1, 1978 to May 31, 1979 were used to answer these questions. The perinatal factors were obtained from the birth questionnaire and the ethnic data were obtained from 2063 participants asked about self-reported skin color at early adulthood (23-25 years of age) in 2002/2004. Mothers of mulatto and black children had higher rates of low schooling (£4 years, 27.2 and 38.0%) and lower family income (£1 minimum wage, 28.6 and 30.4%). Mothers aged less than 20 years old predominated among mulattos (17.0%) and blacks (14.0%). Higher rates of low birth weight and smoking during pregnancy were observed among mulatto individuals (9.6 and 28.8%). Preterm birth rate was higher among mulattos (9.5%) and blacks (9.7%) than whites (5.5%). White individuals had higher rates of cesarean delivery (34.9%). Skin color remained as an independent risk factor for low birth weight (P < 0.001), preterm birth (P = 0.01), small for gestational age (P = 0.01), and lack of prenatal care (P = 0.02) after adjustment for family income and maternal schooling, suggesting that the racial inequalities regarding these indicators are explained by the socioeconomic disadvantage experienced by mulattos and blacks but are also influenced by other factors, possibly by racial discrimination and/or genetics.

Do socioeconomic factors explain why maternal smoking during pregnancy is more frequent in a more developed city of Brazil?

The prevalence of smoking during pregnancy in Ribeirão Preto, a rich Brazilian city, was significantly higher (21.4%) than in São Luís (5.9%), a less developed city. To assess which variables explain the difference in prevalence of smoking during pregnancy, data from two birth cohorts were used, including 2846 puerperae from Ribeirão Preto, in 1994, and 2443 puerperae from São Luís, in 1997/98. In multivariable analysis, risk of maternal smoking during pregnancy was higher in São Luís for mothers living in a household with five or more persons (OR = 1.72, 95%CI = 1.12-2.64), aged 35 years or older (OR = 1.98, 95%CI = 0.99-3.96), who had five or more children (OR = 2.10, 95%CI = 1.16-3.81), and whose companion smoked (OR = 2.20, 95%CI = 1.52-3.18). Age of less than 20 years was a protective factor (OR = 0.55, 95%CI = 0.33-0.92). In Ribeirão Preto there was association with maternal low educational level (OR = 2.18, 95%CI = 1.30-3.65) and with a smoking companion (OR = 3.25, 95%CI = 2.52-4.18). Receiving prenatal care was a protective factor (OR = 0.24, 95%CI = 0.11-0.49). Mothers from Ribeirão Preto who worked outside the home were at a higher risk and those aged 35 years or older or who attended five or more prenatal care visits were at lower risk of smoking during pregnancy as compared to mothers from São Luís. Smoking by the companion reduced the difference between smoking rates in the two cities by 10%. The socioeconomic variables in the model did not explain the higher prevalence of smoking during pregnancy in the more developed city.

Are birth weight and maternal smoking during pregnancy associated with malnutrition and excess weight among school age children?

In the late 1980's child malnutrition was still prevalent in Brazil, and child obesity was beginning to rise in the richest regions of the country. To assess the extent of the nutritional transition during the period and the influence of birth weight and maternal smoking on the nutritional condition of schoolchildren, we estimated the prevalence of excess weight and malnutrition in a cohort of Brazilian schoolchildren from 1987 to 1989. We calculated the body mass index (BMI) of 8- to 10-year-old schoolchildren born in Ribeirão Preto in 1978/79. We considered children with a BMI <5th percentile (P5) to be malnourished, children with P5³BMIpregnancy, marital status, and schooling) and type of school using nominal logistic regression. A total of 2797 schoolchildren were evaluated. There was a significant prevalence of malnutrition (9.5%) and excess weight already tended to increase (15.7%), while 6.4% of the children were obese. Excess weight was more prevalent among children attending private schools (odds ratio, OR = 2.27) and firstborn children (OR = 1.69). Maternal smoking during pregnancy protected against malnutrition (OR = 0.56), while children with lower birth weight were at higher risk for malnutrition (OR = 4.23). We conclude that a nutritional transition was under way while malnutrition was still present, but excess weight and related factors were already emerging.

Mercury toxicity in the Amazon: contrast sensitivity and color discrimination of subjects exposed to mercury

We measured visual performance in achromatic and chromatic spatial tasks of mercury-exposed subjects and compared the results with norms obtained from healthy individuals of similar age. Data were obtained for a group of 28 mercury-exposed subjects, comprising 20 Amazonian gold miners, 2 inhabitants of Amazonian riverside communities, and 6 laboratory technicians, who asked for medical care. Statistical norms were generated by testing healthy control subjects divided into three age groups. The performance of a substantial proportion of the mercury-exposed subjects was below the norms in all of these tasks. Eleven of 20 subjects (55%) performed below the norms in the achromatic contrast sensitivity task. The mercury-exposed subjects also had lower red-green contrast sensitivity deficits at all tested spatial frequencies (9/11 subjects; 81%). Three gold miners and 1 riverine (4/19 subjects, 21%) performed worse than normal subjects making more mistakes in the color arrangement test. Five of 10 subjects tested (50%), comprising 2 gold miners, 2 technicians, and 1 riverine, performed worse than normal in the color discrimination test, having areas of one or more MacAdam ellipse larger than normal subjects and high color discrimination thresholds at least in one color locus. These data indicate that psychophysical assessment can be used to quantify the degree of visual impairment of mercury-exposed subjects. They also suggest that some spatial tests such as the measurement of red-green chromatic contrast are sufficiently sensitive to detect visual dysfunction caused by mercury toxicity.

Operant serial feature-positive conditional discrimination with composite features and different topography responses

In a serial feature-positive conditional discrimination procedure the properties of a target stimulus A are defined by the presence or not of a feature stimulus X preceding it. In the present experiment, composite features preceded targets associated with two different topography operant responses (right and left bar pressing); matching and non-matching-to-sample arrangements were also used. Five water-deprived Wistar rats were trained in 6 different trials: X-R®Ar and X-L®Al, in which X and A were same modality visual stimuli and the reinforcement was contingent to pressing either the right (r) or left (l) bar that had the light on during the feature (matching-to-sample); Y-R®Bl and Y-L®Br, in which Y and B were same modality auditory stimuli and the reinforcement was contingent to pressing the bar that had the light off during the feature (non-matching-to-sample); A- and B- alone. After 100 training sessions, the animals were submitted to transfer tests with the targets used plus a new one (auditory click). Average percentages of stimuli with a response were measured. Acquisition occurred completely only for Y-L®Br+; however, complex associations were established along training. Transfer was not complete during the tests since concurrent effects of extinction and response generalization also occurred. Results suggest the use of both simple conditioning and configurational strategies, favoring the most recent theories of conditional discrimination learning. The implications of the use of complex arrangements for discussing these theories are considered.

Prenatal management, pregnancy and pediatric outcomes in fetuses with septated cystic hygroma

It has been reported that, compared with simple increased nuchal translucency, fetal cases with septated cystic hygroma (CH) are more likely to face perinatal handicaps. However, pediatric outcomes and proper prenatal counseling for this anomaly have not yet been truly defined. We performed this study to determine pregnancy and pediatric outcomes of fetuses with septated CH. We searched records for cases with septated CH and collected data for structural abnormalities, karyotype analysis, and pregnancy outcomes. Fetuses born with septated CH were also evaluated for their pediatric outcomes. Sixty-nine fetuses with septated CH were enrolled in the study. Results showed that chromosomal abnormalities were present in 28 fetuses (40.6%), and the most common aneuploidy was Turner syndrome (n=14, 20.3%); 16 (23.2%) of the remaining cases, in which aneuploidy was not found, had coexistent structural malformations; 25 (36.2%) cases had normal karyotype and morphology. The total number of live births and infants with unfavorable neurologic follow-up were 13 (18.8%) and 2 (2.9%), respectively. Septated CH is associated with poor perinatal outcomes; therefore, karyotype analysis and ultrasonographic anomaly screening should be performed as initial steps, and expectant management should be offered to couples with euploid fetuses that have normal morphology.

Discrimination of Brazilian red wines according to the viticultural region, varietal, and winery origin

This work evaluated the physicochemical composition of 171 red Brazilian wines from the 2006 vintage, which were represented by 21 varietals. These wines were produced by 58 Brazilian wineries in different regions of the country, with latitudes varying from 9º to 31º South. Physicochemical wine analysis was performed in the same year and discrimination in the viticultural regions, varietal wines, and wineries was performed by means of the principal component analysis (PCA). The main results show that wines from São Joaquim had higher values of A420, A520, A620, color intensity, total phenolic compounds, anthocyanins, and dry extracts, while those from Toledo had lower values of these variables; those from Vale do São Francisco had higher values of potassium, pH, density, and volatile acidity; from Serra do Nordeste A, they had higher titratable acidity; and from Planalto Superior B, higher hue. Regarding the varietal wines, PCA mainly discriminated the wines produced from the varieties Ancellotta, Teroldego, Egiodola, Refosco, Marselan, Cabernet Sauvignon, Pinotage, Pinot Noir, Malbec, Arinarnoa, Barbera, and Alfrocheiro. In relation to wineries, twenty two of them were discriminated by their higher values of some variables, i.e., three were characterized by color intensity; three by hue; eight by alcohol content; six by potassium, dry extract, density, and pH; and two by titratablel acidity.

Analytical characteristics and discrimination of Brazilian commercial grape juice, nectar, and beverage

The production and commercialization of Brazilian grape juice is increasing annually, mainly due to its typicality, quality, and nutritional value. The present research was carried out in view of the great significance of Brazilian grape juice for the grape and wine industry. The purpose of this study, therefore, was to assess its composition as well as the discrimination between grape juice and other beverages. Twenty four samples of whole, sweetened, and reprocessed grape juices, grape nectar, and grape beverage were evaluated. Classical variables were analyzed by means of physicochemical methods; tartaric and malic acids, by HPLC; methanol, by gas chromatography; minerals, by atomic absorption spectrophotometry. These products were discriminated by the Principal Component Analysis (PCA). Results show that whole and sweetened grape juices were discriminated from other grape products because they featured higher values of total soluble solids, tartaric and malic acids, most minerals, phenolic compounds, and K/Na ratio, whereas grape nectar and grape beverage presented higher values of ºBrix/titratable acidity ratio. Reprocessed juice was discriminated due to its higher concentrations of Li and Na and lower hue.

Sequence-characterized amplified region (SCAR) technique used for variety discrimination in vinca (Catharanthus roseus (L.) G.Don)

Sequence-Characterized Amplified Region (SCAR) appears as a useful technique for genetic purity testing and variety discrimination, applicable to species in which some other techniques have failed. In particular, this technique is very attractive with species in which RAPD results were not consistent. The RAPD polymorphic bands were cloned, sequenced and from the sequence information, primers pairs for normal PCR were developed. Since the probability of obtaining successful SCAR primers from RAPD polymorphic bands was about 50%, a larger number of RAPD polymorphic bands are needed to develop sufficient SCAR primers for varietal discrimination in vinca. In addition, the efficiency of the SCAR technique is strongly affected by the quality of DNA extracted from seeds. The SCAR banding patterns obtained from vinca seed were consistent and repeatable making the results reliable for genetic purity testing and variety discrimination. The SCAR technique is simple, fast, relatively inexpensive and allows the use of DNA extracted from dry seeds, which is very important in a seed-quality evaluating program

Biomarkers, medical treatment and fetal intrapartum surveillance in intrahepatic cholestasis of pregnancy

Intrahepatic cholestasis of pregnancy (ICP) is a pregnancy-specific disorder characterized by maternal pruritus and elevated liver enzymes. It usually begins in the third trimester of pregnancy and resolves spontaneously after delivery. ICP is considered benign for the pregnant woman, but it is associated with an increased risk for unexplained term stillbirth and preterm delivery. There are no specific laboratory markers to diagnose ICP. The diagnosis is currently based on the presence of maternal pruritus and elevated values of alanine aminotransaminases (ALT) and serum bile acids (BA). Recently, ursodeoxycholic acid (UDCA) has been used for treatment. Mechanisms leading to intrauterine fetal death (IUFD) may be multifactorial and are unknown at present. For this thesis, 415 pregnant women with ICP were studied. The aim was to evaluate the value of the liver enzyme glutathione S-transferase alpha (GSTA) as a specific marker of ICP and to assess the effect of maternal UDCA therapy on maternal laboratory values and fetal outcome. The specific markers predisposing the fetus to heart arrhythmia were studied by comparing waveform analysis of fetal electrocardiograms (FECG) during labor in pregnancies complicated by ICP with controls. The levels of maternal GSTA were high and the values correlated with the value of ALT in patients with ICP. UDCA therapy reduced the values of the liver enzymes and alleviated maternal pruritus, but it did not influence maternal hormonal values. Although the newborns experienced an uneventful perinatal outcome, severe ICP was still associated with preterm birth and admission to the neonatal intensive care unit (NICU). There were no significant differences in intrapartum FECG findings between fetuses born to ICP women and controls.

Tariff discrimination on Brazil's soluble coffee: an economic analysis

This article evaluates the impacts of the imposition of tariffs on the Brazilian soluble coffee mainly by European countries as of the 1990s. More particularly, it verifies whether the imposition of discriminatory trade tariffs by the European Union and of non-discriminatory ones by some Eastern European countries reflects on the international demand for this commodity. For this purpose, dynamic models of global demand for Brazilian soluble coffee were estimated for the 1995-2003 period using data from the International Coffee Organization. Findings suggest that existing tariffs significantly account for the reduction of Brazilian share of soluble in the world market.

ERP and cardiovascular correlates of source memory discrimination in older and younger adults /

There is much evidence to support an age-related decline in source memory ability. However, the underlying mechanisms responsible for this decline are not well understood. The current study was carried out to determine the electrophysiological correlates of source memory discrimination in younger and older adults. Event-related potentials (ERPs) and continuous electrocardiographic (ECG) data were collected from younger (M= 21 years) and older (M= 71 years) adults during a source memory task. Older adults were more likely to make source memory errors for recently repeated, non-target words than were younger adults. Moreover, their ERP records for correct trials showed an increased amplitude in the late positive (LP) component (400-800 msec) for the most recently presented, non-target stimuli relative to the LP noted for target items. Younger adults showed an opposite pattern, with a large LP component for target items, and a much smaller LP component for the recently repeated non-target items. Computation of parasympathetic activity in the vagus nerve was performed on the ECG data (Porges, 1985). The resulting measure, vagal tone, was used as an index of physiological responsivity. The vagal tone index of physiological responsivity was negatively related to the LP amplitude for the most recently repeated, non-target words in both groups, after accounting for age effects. The ERP data support the hypothesis that the tendency to make source memory errors on the part of older adults is related to the ability to selectively control attentional processes during task performance. Furthermore, the relationship between vagal tone and ERP reactivity suggests that there is a physiological basis to the heightened reactivity measured in the LP response to recently repeated non-target items such that, under decreased physiological resources, there is an impairment in the ability to selectively inhibit bottom-up, stimulus based properties in favour of task-related goals in older adults. The inconsistency of these results with other explanatory models of source memory deficits is discussed. It is concluded that the data are consistent with a physiological reactivity model requiring inhibition of reactivity to irrelevant, but perceptually-fluent, stimuli.

Autonomic and electrocortical indices of performance monitoring and source memory discrimination in older and younger adults

Reduced capacity for executive cognitive function and for the autonomic control of cardiac responsivity are both concomitants of the aging process. These may be linked through their mutual dependence on medial prefrontal function, but the specifics ofthat linkage have not been well explored. Executive functions associated with medial prefrontal cortex involve various aspects ofperformance monitoring, whereas centrally mediated autonomic functions can be observed as heart rate variability (HRV), i.e., variability in the length of intervals between heart beats. The focus for this thesis was to examine the degree to which the capacity for phasic autonomic adjustments to heart rate relates to performance monitoring in younger and older adults, using measures of electrocortical and autonomic activity. Behavioural performance and attention allocation during two age-sensitive tasks could be predicted by various aspects of autonomic control. For young adults, greater influence of the parasympathetic system on HRV was beneficial for learning unfamiliar maze paths; for older adults, greater sympathetic influence was detrimental to these functions. Further, these relationships were primarily evoked when the task required the construction and use of internalized representations of mazes rather than passive responses to feedback. When memory for source was required, older adults made three times as many source errors as young adults. However, greater parasympathetic influence on HRV in the older group was conducive to avoiding source errors and to reduced electrocortical responses to irrelevant information. Higher sympathetic predominance, in contrast, was associated with higher rates of source error and greater electrocortical responses tq non-target information in both groups. These relations were not seen for 11 errors associated with a speeded perceptual task, irrespective of its difficulty level. Overall, autonomic modulation of cardiac activity was associated with higher levels of performance monitoring, but differentially across tasks and age groups. With respect to age, those older adults who had maintained higher levels of autonomic cardiac regulation appeared to have also maintained higher levels of executive control over task performance.