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Biomedical subjects

M J Mayaux

Publications and source records attributed to M J Mayaux.

16 recordsLinked to original sources
PubMed1992

The use of viral culture and p24 antigen testing to diagnose human immunodeficiency virus infection in neonates. The HIV Infection in Newborns French Collaborative Study Group.

BACKGROUND: Early diagnosis of human immunodeficiency virus (HIV) infection in infants born to infected mothers is important for the infants' medical care, but the presence of maternal antibodies makes serologic tests uninformative. METHODS: In a cohort study of 181 infants born to HIV-infected mothers, we assessed the diagnostic value of HIV viral culture and testing for the presence of p24 antigen. The infants were tested at birth, again during the first 3 months, then followed and tested at the age of at least 18 months. RESULTS: Of the 181 infants, 3 died of HIV infection and 37 were seropositive after the age of 18 months. Viral cultures at birth were positive in 19 of the 40 infected infants and in none of the uninfected infants, yielding a sensitivity of 48 percent (95 percent confidence interval, 32 to 63 percent) and a specificity of 100 percent (95 percent confidence interval, 97 to 100 percent). By the age of three months, 30 of the 40 infants (75 percent) had positive cultures; again, there were no false positive results among the infants who were tested a second time, of the 141 who remained uninfected. The sensitivity of testing for p24 antigen at birth was only 18 percent, with a specificity of 100 percent. The presence of p24 antigen at birth was associated with the development of early and severe HIV-related disease (P less than 0.04). CONCLUSIONS: Viral culture at birth can correctly identify about half of newborns with HIV infection. The fact that this usually sensitive technique fails to identify about half the ultimately infected neonates suggests that vertical transmission of HIV may occur late in pregnancy or during delivery.

False Negative Reactions↗
PubMed1992

Perinatal HIV transmission facts and controversies.

In 1992, HIV infection in children is essentially due to vertical or perinatal transmission, i.e. from the mother to the fetus and neonates. This is a particularly serious public-health problem in Africa where the percentage of infected women of child bearing age is as high as 20% in some suburban areas. During the last few years, three important points have been established. (i) In Europe and North America, the rate of perinatal transmission is between 15 and 25% and appears to have remained relatively stable with time in various prospective cohorts. (ii) Considerable efforts have been directed at defining the optimal methods for early diagnosis of HIV infection in the infants. At present viral cultures and gene amplification of HIV DNA by polymerase chain reaction are the most promising procedures for early diagnosis within the first 6 months of life. (iii) Finally, the course of the disease in the infected infant has been well characterised, it takes two main forms--that of an early and severe disease or that of a slowly progressive infection: In addition, follow-up is now sufficient to confirm that children with negative tests at 15 months are indeed uninfected. However, knowledge is lacking in a number of essential areas. These include the exact timing of transmission (in utero, during delivery or post-partum), the relative frequency of transmission during each period, the mechanism(s) involved (particularly the role of the placenta), and, finally, the influence of maternal, fetal and viral factors. Answers must be found rapidly in order to develop preventive therapy, to identify women who may have an increased risk of transmitting the virus, to develop a reliable antenatal diagnostic test and, finally, to be in a better position to inform HIV-seropositive women of the relative risks.

Animals↗
PubMed1989

A prospective study of infants born to women seropositive for human immunodeficiency virus type 1. HIV Infection in Newborns French Collaborative Study Group.

Assessment of the risks of transmission of infection with human immunodeficiency virus type 1 (HIV-1) from mother to newborn is difficult, partly because of the persistence for up to a year of maternal antibodies transmitted passively to the infant. To determine the frequency of perinatal transmission of HIV infection, we studied from birth 308 infants born to seropositive women, 62 percent of whom were intravenous drug abusers. Of 117 infants evaluated 18 months after birth, 32 (27 percent) were seropositive for HIV or had died of the acquired immunodeficiency syndrome (AIDS) (n = 6); of the 32, only 2 remained asymptomatic. Another 76 infants (65 percent) were seronegative and free of symptoms, whereas 9 (8 percent) were seronegative but had symptoms suggestive of HIV-1 infection. The infants infected with HIV-1 did not differ from the others at birth with respect to weight, height, head circumference, or rate of malformations, but as compared with newborns who were seronegative at 18 months, their serum IgM levels were higher (78 +/- 81 mg per deciliter vs. 38 +/- 39 mg per deciliter; P less than 0.03) and their CD4 lymphocyte counts were lower (2054 +/- 1221 per cubic millimeter vs. 2901 +/- 1195 per cubic millimeter; P less than 0.006). Neither maternal risk factors nor the route of delivery was a predictor of seropositivity at 18 months; however, 5 of the 6 infants who were breast-fed became seropositive, as compared with 25 of 99 who were not (P less than 0.01). We conclude that approximately one third of the infants born to seropositive mothers will have evidence of HIV-1 infection or of AIDS by the age of 18 months, and that about one fifth of this group will have died.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Paternal age and mental functions of progeny in man.

The effects of maternal age on the quality of offspring are well known. Those due to the father's age are less obvious, apart from the role of increasing paternal age in the onset of many dominant autosomal disorders. But an experimental model has demonstrated that, in rats, increasing paternal age, without any other anomalies, might produce a decreased learning capacity in progeny. The object of the epidemiological investigation presented here was to verify whether this effect might also occur in man. The study involved the distribution of scores obtained in psychometric tests by 18-year-old male subjects, according to their father's age at the time of their birth. This distribution indicated not only that increasing paternal age is accompanied by effects similar to those observed in animals, but also that very young paternal age was also related to these effects. Thus, the curve of such scores produced an inverted U-shape, with maximum scores obtained when the father was about thirty years of age. Maternal age did not appear to play a part in this event. These results pose the problem of identifying genetic and/or psychosocial factors which might have an impact on the quality of the conceptus.

Adolescent↗
PubMed1988

[Donor artificial insemination. Psychological survey of 830 couples].

830 couples who had asked for Artificial Insemination by Donor (AID) were questioned using separate questionnaires for the husband and for the wife. The questions were directed to the reactions that followed in succession to discovery of the sterility, the psychological conditions that led to choosing AID, their attitude as far as secrecy was concerned and finally their contribution to finding donors of sperm. Overall the husband-wife replies corresponded to one another. Frequently the reaction to the news that the man is sterile is a depressive one and to a lesser degree followed by troubles in sexual performance. The choice of AID is usually a decision of both members of the couple. Most couples express themselves as hesitant about adoption. Most of them said that secrecy about the procedure was an essential condition. It appears that, above all, male sterility had to be hidden from the circle in which they associated and from the child. It is this position as far as secrecy is concerned that makes it difficult for the couples to help in recruiting sperm donors.

Attitude↗
PubMed1986

In-vitro fertilization and embryo transfer: a collaborative study of 1163 pregnancies on the incidence and risk factors of ectopic pregnancies.

In a multi-centric study undertaken on 1163 pregnancies obtained by in-vitro fertilization, a 5% risk of ectopic pregnancies was observed. This figure is certainly higher than that admitted for natural reproduction. After simultaneous adjusting for all variables in our data by means of a multiple logistic regression technique, two factors have specific influence: the therapeutic use of clomiphene citrate which increased the rate of ectopic pregnancies from 3 to 6% and the number of patent Fallopian tubes with a change in ectopic pregnancies rate from 3 or 4% (with 0 or 2 patent tubes) to 13% (with one patent tube). These results suggest various physiologic hypotheses as well as therapeutic considerations.

Clomiphene↗
PubMed1976

Classical and "true" gestational postmaturity.

In a study of a sample of 317 conceptional basal body temperature (BBT) curves obtained from normal women, the authors have applied new definitions of prematurity and postmaturity which take into account the time of ovulation. They were thus able to estimate (1) the error rates associated with the classical definitions-incorrect classification as pre- or postmature and nondetection; in particular, for this series, the percentage of incorrectly classified postmatures is high (70 per cent) and is even more so when considering only the unwanted births (80 per cent); (2) the order of magnitude in terms of days of the error made in assessing postmaturity by the classical method. This was found to be quite substantial for the misclassified cases.

Body Temperature↗
PubMed1976

[Length of gestation and parameters of the menstrual cycle].

In studying the BBT curves of 433 conceptional cycles, no evidence was found of any correlation between duration of gestation counted from "zero" day, the last day of the hypothermic phase, and various parameters measuring durations or temperatures evaluated from the curves. There is, in particular, no positive correlation with the duration of the hypothermic phase; and the authors were able, by taking into account the error made in replacing ovulation by "zero" day, to deduce that the "true" duration of gestation is not correlated with the "true" length of the preovulatory phase or indeed with the length of the cycle.

Body Temperature↗
PubMedDate not supplied

Antimitotic drugs in the male rat. Behavioral abnormalities in the second generation.

The second generation descended from rats treated either with cyclophosphamide alone or with both cyclophosphamide and vinblastine were investigated. As in the first generation, the offspring were evaluated for mean litter size, sex ratio, frequency of gross external malformations and, within the first 4 months of life, growth and mortality. When they reached adulthood, between 12 and 16 weeks of age, the offspring were also tested for spontaneous activity and learning capacity. At birth, the progeny of the treated grandfathers did not show malformations or any other obvious disorder. However, when compared with the control population, the experimental animals showed significantly decreased success rates in a learning task, whatever the learning performance of their parents. Furthermore, decreased spontaneous activity was observed in the male subjects from unsuccessful parents. The similarities between the anomalies found in the first and the second generations argue for the induction of mutations by antimitotic drugs. This hypothesis and the subtle differences between generations and between sexes are discussed.

Animals↗
PubMedDate not supplied

Abortion rate in A.I.D. and semen characteristics: a study of 1345 pregnancies.

A study undertaken on 1345 pregnancies resulting from artificial insemination with donor showed an 18% risk of abortion. This figure is the same as that admitted for natural reproduction. It does not depend on any of the classically studied semen characteristics and in particular remains invariant whatever the postthaw motility, the factor most strongly linked to conception rate. Two results, well known from the literature, i.e. the increased abortion rate mentioned in natural reproduction when the sperm is of poor quality and the high incidence of repeated abortions when sperm quality is particularly good are discussed. The first of these results cannot be considered as being established in a statistically significant way. The second may result from different sources of bias, some of which are identified. In essence a high frequency of abortions signifies simply a high frequency of pregnancies, it is therefore not surprising that the semen is in this case particularly good.

Abortion, Habitual↗
PubMedDate not supplied

Correlation between defects in chromatin condensation of human spermatozoa stained by aniline blue and semen characteristics.

Human sperm heads which present disturbances of chromatin condensation are stained by acidic aniline, blue. To determine whether the proportion of unstained heads, i.e. with well condensed chromatin, can be considered as an index of sperm quality, a study was undertaken in 157 men during an infertility evaluation. In addition to the usual sperm characteristics, the percentages of unstained heads and of morphologically normal and abnormal forms were concomitantly evaluated. In a total of 15760 spermatozoa, the percentage of unstained heads was much higher in the population of morphologically normal forms than in that of abnormal forms (79.1% and 49.4% respectively, p less than 10(-9]. Among spermatozoa with structural abnormalities, it was much higher in cells with a single anomaly than in those with associated anomalies (53.9% and 40.6% respectively, p less than 10(-9]. When morphology was taken into account, only vitality was found to vary significantly with the percentage of unstained heads.

Adult↗