Lack of effect of maternal body mass index on anthropometric characteristics of newborns in twin gestations

We examined the correlation between maternal prepregnancy body mass index (BMI) and newborn weight, length, BMI, and gestational order, in singleton and twin births. The sample comprised 381 mothers of multiple babies (562 twins), and 7979 singleton pregnancies, used as controls. The Mann-Whitney non-parametric test was used to compare the values between the two groups, and the Spearman's correlation test (rS) was applied to the quantitative variables. A significant positive correlation was found with singleton baby variables: the higher the maternal BMI, the higher the newborn's BMI, weight, length, and gestational order. However, no significant correlation was found between maternal BMI and any of these variables in twins. Maternal weight gain, in the twin group, showed a significant positive correlation with the newborn gestational order (rS = 0.154; P = 0.002), weight (rS = 0.493; P < 0.001), length (rS = 0.469; P < 0.001), and BMI (rS = 0.418; P < 0.001). In singletons, the correlation was positive with all the variables, except for the gestational order. The newborn BMI was significantly higher in twins born by C-section than those born by vaginal birth (Z = -4.974; P < 0.001). Mothers of singletons delivered by C-section had a significantly higher BMI than those of singletons born by vaginal birth (Z = -1.642; P < 0.001); however, no significant differences were observed in mothers of twins. Prepregnancy maternal BMI in twin births would not be predictive of newborns weight, length and BMI in this population. Maternal weight gain during pregnancy proved to be the most adequate for predicting the weight, length and BMI of twins delivered by C-section

Twinning rate in a sample from a Brazilian hospital with a high standard of reproductive care.

CONTEXT: Epidemiological studies on twin births have been motivated mostly by the positive correlation between twinning rate and human fertility, prematurity, low birth weight, increased risk of infant death and long term risk for morbidity. OBJECTIVE: This paper intends to estimate the incidence of multiple births in a private hospital in Brazil with a high standard of reproductive care, and to evaluate the effects of maternal age, gestation order and assisted fertilization on twinning rate. DESIGN: Retrospective analysis. SETTING: First-class tertiary private hospital, São Paulo, Brazil. PARTICIPANTS: The multiple birth rate was investigated among 7,997 deliveries from 1995 to 1998, including 7,786 singletons, 193 twins, 17 triplets and one quadruplet. RESULTS: The rates per 1,000 dizygotic and monozygotic pairs and for triplets were estimated as 19.51, 4.50 and 2.13, respectively. The dizygotic and triplet rates were the highest observed in Brazil up to the present day. The twinning rate among primigravidae older than 30 years was very high (45.02 per 1,000) and was due to a disproportionately high frequency of dizygotic pairs. The triplet rate was also very high among the mothers of this age group (5.71 per 1,000). These facts are strong indicators that these women were the ones most frequently submitted to assisted reproductive techniques. The mean maternal age of the studied population was about six years higher than that estimated for mothers in the general population of southeastern Brazil. Primigravidae aged under 30 years as well as multigravidae showed similar twinning rates, which were almost 20 per 1,000. Among the deliveries of multigravidae older than 30 years, an unusually high frequency of monozygotic twins was observed (7.04 per 1,000), probably as a consequence of the residual effect of long-term use of oral contraceptives. CONCLUSIONS: The dizygotic twinning rate increased from 13.51 to 28.98 per 1,000 over the four years studied, with the twinning rate for primigravidae over 30 years old in 1998 being twice that observed in 1995. The mean maternal age was also high during this period, but the extremely high increase in twinning rate observed cannot be attributed solely to this variable. Assisted fertilization seems to be the most probable cause of this unusually high twinning rate.

[Intrauterine growth curves in a high-income population] / Curvas de crescimento intra-uterino de uma população de alto nível socioeconômico.

OBJECTIVE: Growth curves can be used to assess intrauterine growth, to predict diseases in newborns, and to characterize different populations. The objective of this study was to obtain intrauterine growth curves of newborns from the maternity ward of the Hospital Albert Einstein (MAE) and compare them with intrauterine growth curves of a population from California, USA. METHODS: We plotted the growth curves according to weight at birth and gestational age, which was obtained according to information from the mother, after the 32nd week of gestation, between February 1995 and February 1999. We calculated the birth weights for the 10th, 50th, and 90th percentiles by each gestational age and compared them with those presented by California growth curves. RESULTS: The growth curves for the 10th and the 50th percentiles did not differ from the California growth curves. For the 90th percentile, however, the MAE growth curves were lower than those of California. The MAE population presented fewer small-for-gestational age (SGA) and big-for-gestational age (BGA) newborns when assessed according to the California curves. The categories of SGA, normal, and BGA for both male and female newborns indicated a statistically significant relation with the weight gain of mothers. CONCLUSIONS: The two populations assessed in this study were different according to intrauterine growth curves. Further studies should be carried out in order to identify specific factors that may be acting on the MAE population.

Hypoendemic malaria in Rondonia (Brazil, western Amazon region): seasonal variation and risk groups in an urban locality.

A longitudinal epidemiologic survey (1989-1991) plus a cross-sectional parasitologic, clinical, and sociodemographic survey (July-October 1990) were conducted in Candeias do Jamary, a village with approximately 7,000 inhabitants in Rondonia, Brazil. Analysis of the results revealed hypoendemic malaria with a complex epidemiology. Plasmodium vivax predominated over P. falciparum infections while infections with P. malariae were absent. Malaria is present throughout the year but was clearly seasonal with epidemic outbreaks in the dry season from June to August. Malaria prevalence was lower in children less than 10 years of age and significantly higher in young adult males, which represent the high-risk group. The incidence of locally acquired infections (autochthonous cases) was significantly lower in the rainy season as compared with the dry season. This is not true with respect to heterotochthonous (imported) malaria cases, that is, malaria acquired elsewhere by Candeias residents, most of whom are male adults working outside the town. In both cases, however, the age and sex distribution of prevalence and its relationship with occupational activities indicate a predominance of outdoor transmission. The results of the cross-sectional survey are in agreement with those of the longitudinal passive survey and, in addition, disclose the absence of asymptomatic infection.

Investigation on seasonality of twin births in Brazil.

The hypothesis of seasonality of twin births was investigated in two important maternity hospitals in the State of São Paulo, Brazil. The study included 1,386 twin births that occurred among 154,699 deliveries from 1984 to 1993. No evidence of seasonality has been detected either for the twin birth rate considered as a whole or for dizygotic twinning rate. The distributions of these rates fitted well sinusoidal regression curves but the cyclic trend did not correspond to any specific season.

Annual variation of sex ratio in twin births and in singletons in Brazil.

The annual variation of the sex ratio (SR) of 1385 twin births was analyzed and compared to that of 85909 singletons. These births referred not only to live births but also to stillbirths in two southeastern Brazilian maternity hospitals from 1984 to 1993. While the annual variation of the SR of singletons was very small, that of twin births was extremely high, due to the significant heterogeneity of the annual data. It is suggested that the large SR annual variation of the twin birth might be a consequence of the variation of male or female monozygotic twins. The hypothesis that twin births show a lower sex ratio than singletons could be supported by the present data.

PIP: This article presents the findings of a study of the annual variation of the sex ratio among twin births compared to singleton births among a maternity population in two urban hospitals in Brazil. Data are obtained from hospital records from a maternity hospital in Campinas and Sao Paulo, Brazil, during 1984-93. There were 1385 twin births and 85,909 singleton births delivered during 1984-93 in these maternity hospitals in Sao Paulo state. Deliveries included stillbirths weighing 500 g or more. Findings indicate that the sex ratio of singletons was 104.6 males per 100 females. The sex ratio of the 763 twins born in Campinas and the 622 twins born in Sao Paulo showed considerable variation from the mean sex ratio of singleton births. The mean sex ratio among twins in Campinas was 107.1 males per 100 females, with a standard deviation of 20.4 in Campinas and 29.7 in Sao Paulo. There were significant differences from the mean sex ratio among twin births in Campinas in 1984 and 1989 and in Sao Paulo in 1984, 1985, 1988, and 1989. There was significant heterogeneity of sex ratios among twin births even with pooled data. The mean of pooled data on twin births was 102.9 males per 100 females, with significant differences from the mean in 1984, 1985, and 1987. The application of Woolf's test indicated heterogeneity in the data and no effect on the sex ratio from twin births. Maternal age was negatively correlated with the sex ratio of twin births. It is argued that monozygotic twins were not primarily females and that twin births did not have a lower sex ratio than singleton births.

Genetic and environmental effects on blood cells.

In a sample of 105 concordant sex MZ and DZ twin pairs, the following characteristics were measured: red cell count, haemoglobin concentration, package cell volume, mean cell volume, mean cell haemoglobin, mean cell haemoglobin concentration, reticulocytes, platelets, white cell count and the six types of leucocytes, lymphocytes, monocytes, band and segmented neutrophils, eosinophils and basophils. The statistical model employed in the univariate twin analysis allows for three sources of variation: genetic (h2), shared environmental (c2) and specific environmental influences (e2). A genetic component was significant for red cell count, haemoglobin and mean cell haemoglobin (0.64, 0.60 and 0.46 respectively), with heritable variation suggested for package cell volume, mean cell volume, mean cell haemoglobin, lymphocytes and monocytes. Shared environmental variation was only present for neutrophils.

A genetic and environmental time series analysis of blood pressure in male twins.

Systolic and diastolic blood pressures were measured on 254 monozygotic (MZ) and 260 dizygotic (DZ) male twin pairs, during middle age (average age 48 years) and at two later age points. Genetic and environmental components of covariation were modeled by time series. For both measures, shared environmental influences were absent and specific environmental influences were largely time-specific. Although heritability was about 0.5 at each time point, genetic variation present at middle age contributed only about 60% to that present 9 years later, the remaining 40% being new. Fifteen years later, at the third time point, no new genetic variation was evident, variation in individual differences being entirely attributable to genetic differences laid down at the two earlier ages.

Functional evaluation of human neutrophils. Is the bactericidal activity correlated with nitroblue tetrazolium reduction?

The cytochemical nitroblue tetrazolium (NBT) reduction test continues to be used in clinical laboratories to detect defects in the oxidative metabolism of phagocytes. However, the specificity of the test is controversial, and it is not clear whether NBT reduction really reflects the microbicidal activity of these cells. In the present study, we evaluated the killing of Staphylococcus aureus by neutrophils from healthy adult individuals and from patients with phagocyte dysfunctions using a fluorochrome phagocytic assay, and compared the results with those obtained with a cytochemical NBT test performed simultaneously. The ability of neutrophils to reduce NBT (expressed as percent reducing neutrophils) with or without a lipopolysaccharide stimulus was not correlated with the bactericidal activity of these cells (expressed as percent killed bacteria per 100 neutrophils). The age and sex of the healthy adults did not influence the results of either assay. It seems that the superoxide anion played a small role in NBT reduction by normal neutrophils, since superoxide dismutase did not significantly inhibit this reaction. Only the absolute absence of NBT reduction reflected the low bactericidal activity of neutrophils, as seen in patients with chronic granulomatous disease (CGD). We conclude that the only clinical usefulness of the NBT test is for the screening of CGD, and that bacterial phagocytic assays are more appropriate for assessing the microbicidal function of neutrophils.

Cerebrospinal fluid levels of lysozyme, IgM and C-reactive protein in the identification of bacterial meningitis.

Lysozyme (LZM), immunoglobulin M (IgM) and C-reactive protein (CRP) levels were determined in cerebrospinal fluid (CSF) from patients classified on the basis of clinical and laboratory findings into three groups: bacterial meningitis (n = 33), lymphocytic meningitis (n = 21) and controls (n = 54). IgM and CRP levels were determined by enzyme-linked immunosorbent assay (ELISA) and LZM by the lysoplate method. Discriminant analysis demonstrated that 93.94% (31/33) and 96.97% (32/33) of patients with bacterial meningitis were correctly classified on the basis of CSF determinations of IgM and LZM, respectively. However, the measurement of CRP levels in CSF correctly classified 100% of these patients (33/33), thus representing a useful additional marker for the screening of bacterial meningitis. Moreover, no more than 4% (3/75) of patients were incorrectly classified as belonging to the bacterial group on the basis of the CRP test. Thus, CRP titres less than or equal to 80 identify cases belonging to one of the non-bacterial groups, whereas titres greater than or equal to 640 classify the bacterial group, with a very low chance of misclassification. The authors recommend that CSF IgM or LZM levels be also measured for patients with CSF CRP titres of 160 and 320, for a more accurate diagnosis. The probability of these cases being of bacterial aetiology, as calculated from the combined results of these measurements, is presented.

[Dose-dependence of the carboxymethylcellulose-papain combination in the prevention of peritoneal adhesions. Study in rats]. / Dose-dependência da associação carboximetilcelulose-papaína na prevenção de aderências peritoneais. Estudo em ratos.

The action of a low volume (one drop) of sodium carboxymethylcellulose (CMC)-papain (PP) association gel to prevent peritoneal adhesions were studied in female Wistar rats. After ether anesthesia and a midline laparotomy incision, the right parietal peritoneum was pinched with a fine hemostat and the pinched peritoneal fold was then ligated. This maneuver was repeated thrice creating four points as if they were little "polyps" with a standardized size. Before closing the incision it was deposited on each point 0.05 ml (one drop) of CMC 2% (group A) or CMC + PP 0.4% (group B), with a total volume of 0.2 ml. These groups were compared with another similar group (group C) of a previous research, in which was used 7 ml/kg of body weight of CMC + PP 0.4% (1.5 ml by animal). Statistically significance was not noticed between groups A and B but it was noticed between these two groups (A and B) and group C (p < 0.001 and p < 0.01, respectively). It was concluded that the lowest effective volume (between 0.2 and 1.5 ml/animal) which can allow the desired effect is to be determined in order to diminish the quantity of substance to be deposited in the abdominal cavity.

[Prevention of peritoneal adhesion formation with a combination of carboxymethyl-cellulose and papain: experimental study]. / Prevenção da formação de aderências peritoneais pela associação carboximetilcelulose-papaína: estudo experimental.

The inhibitory action of sodium carboxymethylcellulose (CMC) and papain (PP) in peritoneal adhesions formation, were studied in Wistar rats. After ether anesthesia and a midline laparotomy incision, the right parietal peritoneum was pinched with a fine hemostat and the pinched peritoneal fold was then ligated. This maneuver was repeated thrice creating four point as if they were little "polyps" with a standardized size. Before closing the incision, it was deposited on the four points of each animal the following substances: group A--saline solution; group B--CMC 2%; group C--PP 0.4% in distilled water; group D--CMC 2% + PP 0.2%; group E--CMC 2% + PP 0.4%. After ten days, the rats were sacrificed and classified according to the number of "points" that showed adhesions with the abdominal structures. There was a statistically significant decrease in the incidence of adhesions only in the group E (CMC + PP 0.4%).

Short stature in Duchenne muscular dystrophy.

Growth rate was assessed in 187 boys affected with Duchenne muscular dystrophy (DMD) and bone age in 127 among them. Patients' heights were compared with their normal sibs, with expected stature according to midparents' stature and with normal Brazilian children of comparable age. The results showed that DMD boys have a normal length and weight at birth, but a delayed growth starting during the first years of life with a mean approximate decrease of -6.00 cm according to the expected height of the normal Brazilian population. The proportion of DMD patients with short stature (below the 3rd centile) was similar in younger boys (up to 7 years) to that in the older group (more than 7 years) of affected boys. Bone maturation in DMD boys did not differ from their normal sibs. Weight was also decreased in DMD patients as compared with normal sibs of comparable age.

Estimates of genetic and environmental components of serum isocitrate dehydrogenase (ICDH) in normal twins.

Environmental (b2) and genetic heritability (h2) of serum isocitrate dehydrogenase (ICDH) were estimated in 96 pairs of healthy twins according to a path analysis model. The results showed significant heritability (0.42) and a very low environmental component (based on obesity and level of habitual physical activity), suggesting that these factors do not influence ICDH serum activity.

Estimate of the intrafamilial correlation for serum creatine kinase and pyruvate kinase in females at risk for Duchenne and Becker muscular dystrophies.

In order to verify the possibility of nonrandom X-inactivation in females heterozygous for Duchenne (DMD) and Becker (BMD) muscular dystrophies, intrafamilial correlations and the heritabilities for serum creatine kinase (CK) and pyruvate kinase (PK) were estimated in a large sample of females belonging to families with affected patients. The results of the present investigation suggest that the apparent intrafamilial correlations for serum CK reported in previous studies in DMD families are not related with the presence of the DMD/BMD gene. Our data do not seem to support the hypothesis of a gene leading to a preferential inactivation of the X-chromosome in females at risk for the dystrophin gene.

Controle de qualidade dos venenos animais e dos correspondentes antivenenos: I. Padronizaçäo dos métodos de ensaio das atividades bioquímicas e farmacológicas dos venenos de algumas espécies do gênero Bothrops e Crotalus ... / Quality control of animal venoms and of their correspondent antivenoms: I. Standardization of the assay methods to analise the biochemical and pharmacological properties of venoms from some snakes belonging to the genus Bothrops and Crotalus...

Para a avaliaçäo das atividades promotoras da coagulaçäo do fibrinogênio e do plasma e indutoras de edema, hemorragia, necrose e mortalidade presentes no veneno de algumas serpentes brasileiras (B.alternatus, B.atrox, B.cotiara, B.jararaca, B.jararacussu, B.moojeni, B.neuwiedi e crotalus durissus terrificus) foram padronizados métodos de ensaio. De cada espécie de serpente foram preparadas misturas homogêneas de venenos, o teor protéico determinado pelo método de Lowry et al.(6) e cada mistura dividida igualmente em duas amostras, uma sendo seca sob vácuo à temperatura ambiente (VS) e a outra liofilizada (VL), e ambas armazenadas a 20'C. O teor protéico foi da ordem de 1.0-1.5 mg/mg de veneno seco na maioria das espécies e da ordem de 0.8-0.85 mg/mg no veneno de B.cotiara. A atividade enzimática, medida pela proteólise da caseína, foi muito pronunciada nos venenos de B.atrox e B.moojeni, baixa no veneno de B.cotiara, intermediária no veneno das demais espécies do gênero Bothrops e praticamente indetectável no veneno de c.d.terrificus. As atividades hemorrágica e necrotizante, conquanto presentes no veneno de todas as espécies botrópicas, foram bastante elevadas no veneno de B.neuwied e ausentes no veneno de c.d.terrificus. Todos os venenos testados exibiram atividade edematogênica. A atividade promotora de coagulaçäo, embora presente em todos os venenos, foi mais alta nos venenos de B.atrox, B.cotiara e B. neuwiedi. A atividade letal, medida em termos de DL50, foi marcadamente elevada no veneno de c.d.terrificus e alta nos venenos de B.jararaca e B.neuwiedi em comparaçäo com os venenos das demais serpentes do gênero Bothrops. Em todos os ensaios as amostras de veneno VS e VL foram sempres testadas em paralelo. Conquanto as atividades enzimáticas e biológicas dos venenos näo se diferissem em ambas as amostras, o processo de liofilizaçäo deveria ser o método de escolha pelo fato de associar, durante o processo de secagem, congelaçäo e vácuo, condiçöes que presumivelmente preservariam melhor a configuraçäo molecular natural da maioria das proteínas

Evaluation of a fluorochrome assay for assessing the bactericidal activity of neutrophils in human phagocyte dysfunctions.

We evaluated a method for the assessment of the phagocytic and bactericidal activity of human peripheral neutrophils against Staphylococcus aureus Cowan I, which is a modified version of the acridine orange staining technique originally described by Smith and Rommel (1977). The modification consisted of the use of free leukocyte suspensions rather than coverglass adhered leukocytes in order to avoid two main problems: the inefficient neutrophil adherence to glass that can be observed in specimens from patients with certain functional phagocyte defects, and the risk of selecting among neutrophils. An additional advantage of the modified procedure is that it permits a uniform bacteria: phagocyte ratio in different cell samples. The method was tested on 25 healthy adults and on four children with functional phagocytic defects (chronic granulomatous disease of infancy, Chediak-Higashi syndrome, and Rothmund-Thomson syndrome associated to persistent neutropenia and low chemotactic response). The neutrophils of all four patients showed a low bactericidal activity, with percent values of intracellular killed bacteria below the mean +/- 2 SD range observed in the healthy population at all incubation times tested (5, 15 and 30 min). A significant reduction in phagocytosis index and in % killed unopsonized S. aureus was observed in relation to bacteria treated with a pool of normal human serum. These results demonstrate the high sensitivity of the method, which could be used to determine intrinsic and extrinsic functional alterations in human neutrophils.

Purification of F(ab')2 anti-snake venom by caprylic acid: a fast method for obtaining IgG fragments with high neutralization activity, purity and yield.

Pooled horse plasma containing antibodies against Crotalus durissus terrificus whole venom were digested with pepsin at an enzyme-substrate ratio of 8:1, pH 3.1, for 40 min and the F(ab')2M fragments purified by adding 8.7% caprylic acid (pH 5.0). For comparison, F(ab')2B purified by precipitation with ammonium sulphate and uncleaved IgG purified with caprylic acid were also prepared. Fab' fragments were obtained by reduction and alkylation of F(ab')2B. The anti-whole C.d. terrificus venom titers, determined by Dot-Blot were 12,800 (IgG), 6400 [F(ab')2B], 4800 [F(ab')2M] and 3200 (Fab'B). Immunochemical analysis of these fragments by SDS gel electrophoresis, Western blot and by double immunodiffusion revealed that the solution containing F(ab')2M was free of IgG and of other plasma proteins, whereas that containing F(ab')2B was not. One milligram of either F(ab')2B, F(ab')2M or Fab'B was able to neutralize respectively 20.7 micrograms, 20.2 micrograms and 13.8 micrograms of C.d. terrificus venom.

Genetic and environmental components of serum creatine kinase (CK) and pyruvate kinase (PK) in normal twins: implication for genetic risks estimates in Duchenne muscular dystrophy carriers.

The serum activity of creatine kinase (CK) and pyruvate kinase (PK) was measured in 98 pairs of same-sex Brazilian twins. The purpose of this study was to estimate the genetic and environmental components of serum activity levels for both enzymes. Heritabilities were estimated separately by path analysis in each sex. The results showed that CK and PK activities are under genetic control in normal males and females. Environmental components were not statistically significant for CK or PK. The genetic component of both enzymes estimated in females has implications in the calculation of genetic risks for Duchenne muscular dystrophy carriers.

Relation between height and clinical course in Duchenne muscular dystrophy.

We have evaluated the relation between height and rate of clinical progression in boys with Duchenne muscular dystrophy (DMD). In all, 111 DMD patients with age ranging from 2 to 23 years (mean 8.2 +/- 3.4 years) were assessed; of these patients, 92 had their height measured. Clinical course was determined through Vignos scale of functional disability, motor ability, and timed functional tests. All patients had grossly elevated serum creatine-kinase (CK) and pyruvate-kinase (PK) levels. When height was adjusted for patients' age, a statistically significant correlation was found between height and clinical course (positive with Vignos scale and negative with motor ability), suggesting that smaller boys have a better clinical course than taller patients of comparable age. These results support our previous hypothesis and suggest that growth inhibition seems to be effective in diminishing the progression of DMD.