Laura A. Zonta

Serum IgG subclass concentrations in healthy subjects at different age: Age normal percentile charts

IgG subclass levels were determined in 448 normal children from 6 months to 18 years of age and in 141 healthy adults by radial immunodiffusion using monoclonal antibodies. Age-normal percentile values were calculated for each year of age up to 18 years for IgG1, IgG2, IgG3 and in adults for all four subclasses. The broad spread of IgG4 values in children did not permit calculation of reference values.

Birthweight by gestational age in preterm babies according to a Gaussian mixture model

Objective  To provide a statistically sound criterion for identifying implausibly large birthweights for gestational age.

Paternal Age and Preterm Birth in Italy, 1990 to 1998

Background: Advanced paternal age has been reported to impair pregnancy outcome. Here, we investigated the association of advanced paternal age with preterm birth by using a very large national data set. Methods: We analyzed data from 1990 to 1998 on Italian firstborn singletons to mothers 20–24 and 25–29 years of age (n = 1,510,823). Odds ratios for overall preterm (<37 weeks’ gestation), very preterm (<32 weeks), and moderate preterm (32–36 weeks) births were evaluated through logistic regression models in paternal age classes (20–24, 25–29, 30–34, 35–39, 40–44, 45–49, 50+ years) after adjustment for confounders. Nonparametric regression models were used to fit the effect of paternal ageing on the incidence of very preterm births. Results: Odds ratios increased with paternal age more rapidly for very preterm than for moderate preterm births; among 45- to 49-year-old fathers, odds ratios for very preterm births reached 1.91 (95% confidence interval = 1.08–3.38) and 1.72 (1.25–2.36), respectively, in 20- to 24- and 25- to 29-year-old mothers. Conclusions: This study confirms that paternal age contributes to the risk of preterm birth. The effect is stronger on very preterm births but also influences moderate preterm births.

Evaluation of response to methotrexate by a functional index in juvenile chronic arthritis.

SummaryIn juvenile chronic arthritis (JCA) the indices of disease activity, such as joint swelling, pain, tenderness, and limitation of motion, may poorly correlate with the degree of functional impairment. Since the improvement of functional capacity is one of the main objectives of treatment, we evaluated the effect of methotrexate (MTX) in 29 children with JCA by assessing both the articular indices and a functional status measure. After 6 months of therapy, 15 of the 29 patients had a significant (≥50%) reduction in the number of joints with active arthritis and/or the articular severity score and were then judged as responders, while 14 did not respond to MTX. In the responder group, the median functional index score decreased from 17 (range: 13–27) at baseline to 13 (range: 13–15) at 6 months (p<0.001); the median score of the non-responder group was 20 both at baseline and at 6 months (ranges: 14–27, and 13–36, respectively). These results show an improvement of functional impairment in those patients who respond to MTX according to the conventional indices of articular inflammation.

Late childbearing and its impact on adverse pregnancy outcome: stillbirth, preterm delivery and low birth weight.

BACKGROUND The role of parental ageing on the incidence of adverse pregnancy outcome is based on increased morbidity and obstetric problems during pregnancy and delivery in old mothers, and on the accumulation of spontaneous harmful mutations for continuous cell divisions during spermatogenesis in old fathers. The aim of this study is to estimate the impact of paternal and maternal ageing on the risk of adverse pregnancy outcome. DATA AND METHODS From the group of 3,616,622 Italian singletons born in 1990-1996 we estimated the risks of stillbirth, preterm birth (<37 weeks of gestation) in live births, and low birth-weight (< 2.3 Kg) in live full-term births. The risks were estimated as a function of maternal and paternal ageing through logistic regression models, which included, as covariates, parity (1st, 2nd, > or =3rd) and family education (low, < or =8 years of schooling for both parents; high, >8 years for at least one parent). Parental ages were examined as quantitative (in one year classes) or categorical factors (in three classes: fathers 20-29, 30-39, > or =40; mothers 20-29, 30-34, > or =35). RESULTS AND CONCLUSIONS We found that, compared with 20-29-year old parents, mothers > or =30 years and fathers > or =40 years are at risk of adverse pregnancy outcome. The effects are more relevant for preterm births and greater in the least than in the most favourable birth conditions, i.e., in first-born children of less educated families than in second-born children of highly educated families. For the risk of a preterm delivery, the odds ratio is OR = 1.32 [1.28-1.36] in mothers aged 30-34 years, and OR=1.97 [1.88-2.07] in mothers 235 years in the least favourable conditions, and OR = 1.14 [1.10-1.18] and OR = 1.56 [1.22-1.27] respectively, in the most favourable conditions. The impact of paternal ageing is smaller but significant in fathers > or =40 years: for the risk of a preterm birth, the odds ratio is OR = 1.40 [1.33-1.47] in the least favourable conditions, and OR = 1.14 [1.08-1.21] in the most favourable conditions. This last, baseline risk might be indicative of a paternal genetic component associated with childbearing in advanced age.

Trends in Childbearing and Stillbirth Risk: Heterogeneity among Italian Regions

Abstract: In Italy, as in all Western countries, the almost monotonic decline in fertility observed since the 1960s has been paralleled until the beginning of the 1980s by a decrease in maternal age at delivery. Since then, age at marriage and at childbearing has been increasing and marital fertility has continued to decrease. By 1994 Italy showed extreme values of low total fertility rate (1.22) and of high mean maternal age at delivery (29.7). For the period between 1960 and 1994 we identified five U-shaped patterns in maternal age at delivery corresponding to five geographical areas, which differ socioeconomically and culturally. Since it is well known that an increase in the maternal age is accompanied by an increase in the risk of unfavorable pregnancy outcome, we estimated the stillbirth risk run by older (>=35 years) mothers who delivered in 1994, with respect to their younger counterparts. The differences between the areas are reflected in the higher risk in southern compared to northern Italy: the maximum value occurred in Sicily (odds ratio 2.02, 95% confidence interval, 1.51-2.70) and the minimum value, even lower than in the north but not statistically significant, was found in Sardinia (odds ratio 1.25, 95% confidence interval, 0.81-1.91), known to be characterized by peculiar cultural and biological features.

IgG subclass serum levels in juvenile chronic arthritis.

IgG subclass levels of sera from 26 patients with juvenile chronic arthritis (JCA) were determined by means of mouse monoclonal antibodies. Patients were divided into three groups according to clinical activity of the disease: active disease, partial remission, and remission. One hundred and sixty four age matched, healthy children served as controls. IgG subclass concentrations were log transformed, and a robust regression method was applied to obtain expected values for the different ages. We found a significant increase of IgG3 (p less than 0.0001), IgG1 (p less than 0.002), and IgG2 (p less than 0.035) in JCA sera, while IgG4 values did not differ significantly from those of controls. When patients were divided according to clinical activity significant increases of IgG2 and IgG4 were observed in the patients in partial remission. Our data suggest that differential increase of IgG subclasses during the courses of JCA may be of relevance to the pathogenesis of the disease.

Evaluation of microbiological air quality and of microclimate in university classrooms.

The proliferation of air-diffused microorganisms inside public buildings such as schools, hospitals, and universities, is often indicated as a possible health risk. In this research, we have illustrated the results of an investigation realized to determine the health of the air in some university classrooms, both from a microbiological and a microclimatic viewpoint, during the normal didactic activity of direct lessons. The results obtained have been expressed by means of contamination indices, already used in previous works. Very little contamination was recorded in the different phases of air treatment, which underlines the efficiency of the system and of the maintenance protocols. The Global Index of Microbial Contamination (GIMC per cubic meter) showed a value greater than the mean during the heating period (290), while the highest values (95th percentile 1,138.45) were recorded in the period using air conditioning. The index of mesophilic bacterial contamination, though it did not show any significant differences in the various modes of air treatment, showed a mean value (1.34) and the 95th percentile value (4.14), which was greater in the air-conditioning phase. Finally, the mean value of the amplification index underlined a decrease in the microbial contamination in comparison to the outside, while showing situations of increased microbial amplification during the period of simple ventilation (95th percentile 4.27). The 95th percentile values found for GICM in the three sampling periods, however, permitted us to identify the value of GIMC per cubic meter equal to 1,000 as a guide to provide a means of self-monitoring the quality of the air inside the classrooms. From a microclimatic viewpoint, two periods of the year manifested discomfort situations: during the heating phase (winter) and during the simple ventilation phase (spring). The results obtained indicate, therefore, a need to intervene on the environmental parameters, not being able, in this particular case, to intervene on other aspects that influence the microclimate.

Genetic analysis of adult locomotor activity in Drosophila melanogaster

This study is an attempt to identify genes influencing spontaneous adult locomotor activity in Drosophila melanogaster. A wild type stock and 13 morphological marker stocks (six markers for chromosome X and seven for chromosome three have been used). Backcrosses have been set up to study linkage relationships between loci affecting the quantitative character and marker loci. The results suggest the presence of several genes influencing locomotor activity on both chromosomes analyzed.

Is G6PD A- deficiency associated with recurrent stillbirths in The Gambia?

Hereditary deficiencies in glucose-6-phosphate dehydrogenase (G6PD), first identified in the late 1950s, are the most common enzymopathy known, affecting well over 400 million people worldwide, particularly those from the Mediterranean region, and African and Asian countries. The main clinical complication associated with common deficiencies of G6PD, a cytoprotective enzyme for oxidative stress, is red blood cell hemolysis after ingestion of oxidant drugs. Past studies have shown that litters from untreated pregnant mice with a hereditary G6PD deficiency had increased prenatal (fetal resorptions) and postnatal death [Nicol et al., 2000]. These studies have provided evidence of a critical embryoprotective role for G6PD in oxidative stress and DNA damage. In humans, 100 genetic mutations involving 12 coding exons have been identified so far, andup to 400 enzymevariants have been described. Despite the extensive heterogeneity, a single molecular variant, G6PD Aseems predominant in subSaharan Africa. This variant differs from the normal G6PD B allele by two missense mutations, an A to G transition at position 376, encoding the B to A change (Asn126Asp), and a G to A transition at position 202, encoding the Achange (Val68Met). This last mutation differentiates the Aallele with 12%enzymatic activity from theAallelewith 85%activity [Battistuzzi et al., 1977]. The molecular variant G6PD Acauses a mild deficiency (World Health Organization class 3 G6PDdeficiency), and is associatedwith self-limited hemolytic anemia in oxidative stress [Beutler, 1994]. We examined whether G6PD Awould be related to poor obstetric history in West African women from The Gambia. During the 1999 community-based reproductive morbidity survey in the Farafenni area of rural Gambia, we obtained a pregnancy history on 1,348 participants [Walraven et al., 2001]. Twenty-two of the participating women reported 3 miscarriages or more, 39 women reported more than 1 stillbirth, 41 women more than 1 early neonatal death, and 57 women infertility-problems (aged 25–44 years, not pregnant and not having given birth in the previous 5 years in spite of at least 1/ week regular sexual contact while living with a male partner and not using contraceptive methods). We have defined G6PD Agenotypes in a case-control study of female infertility/subfertility fromTheGambia,WestAfrica, and compared the G6PD Agenotypes in women with a poor obstetric history (cases) with women who had no adverse pregnancy event and reported a live-birth in the last 3 years (controls). The two samples werematched for age (same 5-year band) and ethnic group. Genomic DNA was extracted from buffy coats or whole blood using a standard salting out procedure, and G6PD Agenotyping was performed by PCR, using an amplification refractory mutation system (ARMS), which detects the G to A transition at position 202. Allelespecific primers and one consensus complementary primer were designed to amplify a 271 and 358 bp segment, respectively. Primers for G6PD Aare: 50-CACCAAGGGTGGAGGATGA30 for the forward consensus primer, 50-GGAACGGGCATAGCCCAC-30 for G6PD 202G and 50-GGAACGGGCATAGCCCAT-30 for G6PD 202A. Prior to this study the validity of the ARMS had been confirmed on 100 different G6PD202 genotypes by anRFLP based assay. The 25 ngwhole genome amplified DNAwas added into a 15 ml reaction with 15 pmol each forward and reverse primer, 16 mM (NH4)2 SO4, 67 mM Tris-HCl (pH 8.8 at 258C), 0.01% Tween-20, 1.9 mM MgCl2, 0.6 mM each dNTP, and 0.25 U Taq DNA polymerase (BiolineLtd.,London,UK).Cyclingconditionswere968C1min, 5 cycles of 968C 35 sec, 708C 45 sec, and 728C 35 sec, then 21 cycles of 968C 25 sec, 658C 50 sec, and 728C 40 sec, then 6 cycles of 968C 35 sec and 558C 1 min, followed by 728C 90 sec. PCRproductswere electrophoresed ona1%agarose gel, stained with Ethidium Bromide and digitally photographed using aGel Doc System 2000 apparatus (Bio-Rad Laboratories Ltd., Hertfordshire, UK). DNAwas available for a total of 171women. Seven out of the 83 cases (8.4%) and2out of the 88 controls (2.2%)had theG6PD Adeficiency heterozygous genotype, a threefold, though not statistically significant, difference (Fisher’s exact test P1⁄4 0.072). Among the cases, 5 of the 25 women (20%) with a history of more than one stillbirth had the G6PD Adeficiency heterozygous genotype, while the deficiency was present in only 2 of the remaining 58 women (3.4%) with a history of at least 3 miscarriages (1/10) or 2 neonatal deaths (0/16), or infertility (1/34) (Fisher’s exact testP1⁄4 0.024). The association is even more significant when stillbirth cases only are compared to controls (Fisher’s exact test P1⁄4 0.005). This preliminary study, although carried out ona smallWest African sample, would suggest that poor obstetric history in general and more specifically repeated stillbirths are associated with G6PD Adeficiency. This could be an important finding. There is evidence that the Amutation has attained high frequencies in sub-Saharan African populations, because of thenatural selective advantage conferred by theA-mutation against severe malaria [Ruwende et al., 1995], in full agreement with the same mechanism hypothesized by J.B.S. Haldane in 1948 for thalassemias. However, a mathematical model by Ruwende et al. [1995] incorporating the advantage against malaria has suggested a counterbalancing selective disadvantage, whichwould have retarded a predictedG6PDAfrequency increase in malaria endemic regions if positive selection against malaria were the only acting pressure. If G6PD Ais important in determining stillbirth it would have a negative impact on fitness, and this could be one of the disadvantageous counterbalancing factors responsible for the Grant sponsor: Medical Research Council award (to G.S.); Grant number: G0000690.