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Biomedical subjects

M Duyme

Publications and source records attributed to M Duyme.

At least 37 records · Page 2Linked to original sources
PubMed2000

Hemispheric asymmetry and corpus callosum morphometry: a magnetic resonance imaging study.

Previous post-mortem studies (Aboitiz, F., Scheibel, A.B., Fisher, R.S., Zaidel, E., 1992. Brain Res. 598, 154-161 and Aboitiz, F., Scheibel, A.B., Zaidel, E., 1992. Brain 115, 1521-1541) have shown an inverse association between asymmetry in perisylvian areas and the size of a specific segment, the isthmus, of the corpus callosum (CC) in males. The purpose of this work was to study in vivo the association between hemispheric asymmetry and the total size of the CC in 35 right-handed subjects (16 males, 19 females; mean age 24.9 +/- 3.9). An MRI scan was performed for each subject. The area of the right (RH) and left (LH) hemispheres were measured from images in the sagittal plane and the area of the CC from images in the mid-sagittal plane. The index of hemispheric asymmetry was absolute value((LH - RH)/[(LH + RH)/2]). There was a negative correlation between the absolute value of hemispheric asymmetry and the size of the CC in males (r = -0.55, P = 0.03) but not in females (r = -0.20, P = 0.42). These findings, like those of Aboitiz et al. (Aboitiz, F., Scheibel, A.B., Zaidel, E., 1992. Brain 115, 1521-1541), suggest a sex-dependent decrease in interhemispheric connectivity with increasing hemispheric asymmetry.

Adult↗
PubMed2000

Fetal biometric parameters, twin type and birth weight difference. A longitudinal study.

OBJECTIVE: To examine the relationship between twin type, divided by zygosity, chorionicity, and birth weight difference [more or less than 15% intertwin weight difference at delivery] on fetal biometric measurements, including biparietal diameter, transverse abdominal diameter, head and abdominal circumferences (AC) and head and abdominal areas, femur length (FL), transverse cerebellar diameter, cerebellar circumference and cerebellar area at 18, 23, 28 and 32 weeks of gestational age. STUDY DESIGN: A prospective and longitudinal study was done on 75 twin pairs that did not present the twin-twin transfusion syndrome (150 fetuses) divided into birth weight difference group I (<15%) and group II (>/=15%). The twin pairs were divided into three groups: dizygotic, monochorionic, and dichorionic-monozygotic. In each group the differences in various ultrasound indices were evaluated in reference to discordant growth or concordant growth. RESULTS: In our sample, there were no monozygotic twin pairs with dichorionic placentation with a birth weight difference of more than 15%. Significant associations of group and gestational age were found in dizygotic and monochorionic twins. Intrapair differences were significantly higher in group II (>/=15%) than in group I (<15%) for all fetal parameters studied except for AC, abdominal area and all cerebellar parameters. The value of these discrepancies increased according to gestational age except for FL. Significant interactions between group and zygosity type indicated that intrapair FL differences were more associated with group in monochorionic twins, whereas intrapair transverse cerebellar diameter differences were more associated with group in dizygotic twins. CONCLUSION: Our data show that most fetal biometric parameters are associated with birth weight discordancy. Abdominal area could be a relevant marker for twins with obstetric complications. Note that this is the first research that has studied a twin sample divided by both twin type and birth weight group.

Biometry↗
PubMed2000

[Biometry 2000. Fetal growth charts by the French College of fetal ultrasonography and the Inserm U 155].

OBJECTIVE: The aim of Biometry 2000 was to establish reliable sonographic fetal auxology reference charts for biparietal diameter, head circumference, abdominal diameter, abdominal circumference and femur length. DESIGN: A prospective multicentric longitudinal and transversal study was carried out. SUBJECTS: The data of this study were obtained from 35,456 scans recorded in 10,043 women for a period of one year. METHODS: Sonographic measurements were performed using a single method for each parameter. Twins and unknown gestational ages were not included. No exclusions were made for small-for-age, congenital malformations or any event during pregnancy. Assuming measurements have a normal distribution, centiles were calculated after polynomial regression models from mean and standard deviation according to gestational age in exact weeks from last menstrual period. RESULTS: A total of 32,584 fetal biparietal diameters, 20,400 direct cephalic circumferences, 31,790 transverse abdominal diameters, 21,562 direct abdominal circumferences and 30,960 femur lengths were obtained. Fetal growth charts with means, standard deviations and centiles are presented. CONCLUSION: The multicentric study, Biometry 2000, has established sonographic fetal charts derived from a large sample of scans and unselected pregnant women assuming a normal distribution.

Abdomen↗
PubMed1999

How can we boost IQs of "dull children"?: A late adoption study.

From 5,003 files of adopted children, 65 deprived children, defined as abused and/or neglected during infancy, were strictly selected with particular reference to two criteria: (i) They were adopted between 4 and 6 years of age, and (ii) they had an IQ <86 (mean = 77, SD = 6.3) before adoption. The average IQs of adopted children in lower and higher socioeconomic status (SES) families were 85 (SD = 17) and 98 (SD = 14.6), respectively, at adolescence (mean age = 13.5 years). The results show (i) a significant gain in IQ dependent on the SES of the adoptive families (mean = 7.7 and mean = 19.5 IQ points in low and high SES, respectively), (ii) IQs after adoption are significantly correlated with IQs before adoption, and (iii) during adolescence, verbal IQs are significantly lower than performance IQs.

Adolescent↗
PubMed1999

Is there a negative correlation between explicit memory and hippocampal volume?

The aim of this research was to study the relationship between explicit memory and hippocampal volume. Seventy healthy adults were administered one implicit memory test and one explicit memory (EM) test and underwent magnetic resonance imaging. The major finding was a negative correlation between the EM test and the right hippocampus/brain volume ratio (t = -0.25, P = 0.03) and the left hippocampus/brain volume ratio (t = -0.27, P = 0.02). This finding is not consistent with pathologic findings, which tend to show a relationship between decrease in memory performance and hippocampal atrophy. This discrepancy is discussed.

Adolescent↗
PubMed1999

Perinatal mortality in twin pregnancies: a 3-year analysis in Seine Saint-Denis (France).

OBJECTIVES: Our purpose was to evaluate perinatal mortality in twins and to investigate factors associated with this mortality. STUDY DESIGN: A prospective study on the perinatal mortality was performed in the department of Seine-Saint-Denis. Out of all the perinatal deaths, we have retrospectively isolated those arising from twin pregnancies. RESULTS: There were 54 twin pregnancies complicated with perinatal death. The perinatal mortality rate in twin pregnancy was 78.0 per 1000 twin babies delivered. Out of 86 twin deaths, 38 (44.2%) were born before 28 weeks gestation and out of 82 twin perinatal deaths, 37 (45.1%) weighed less than 1000 g. Chorionicity was recorded in 44 twin pairs: 21 (47.7%) were dichorionic and 23 (52.3%) monochorionic. Finally, out of 48 twin sets there were four (8.3%) monoamniotic pregnancies. CONCLUSIONS: The present data show that extreme prematurity represents nearly half of perinatal mortality in twins. This study indicates also a significant proportion of monochorionic placentation among twin pregnancies with poor outcome.

Adult↗
PubMed1999

Procedure to extract a weekly pattern of performance of human reaction time.

A study of reaction time in six tests (speed of simple identification, simultaneous and sequential letter identification, simultaneous and sequential stimulus word matching, and semantic verification) was carried out on 130 children aged 7 to 12 years. Subjects were tested Monday, Tuesday, Thursday, and Friday, using a cross-sectional design. The answers to each of the tests are binary in nature (Yes/No) measured by the recording of a click one of the two buttons of a microcomputer. Controlled variables were age, failure, sex, and day of test. The greatest percentage of the variance produced by the data was due to the age (typically 25%). The percentage attributable to the "day of test" (typically 5%) is hence masked by the variance due to the other factors. The method proposed herein makes it possible to isolate the percentage of the variance for the variable "day of test" alone and to provide evidence for a circaseptan effect on reaction time. It used a regressive correction on predominant variables. This effect shows performance is best on Thursday and weakest on Monday, the amplitude of the weekly rhythm being related to the task.

Achievement↗
PubMed1998

Magnetic resonance imaging of cerebral central sulci: a study of monozygotic twins.

The cerebral central sulci, seat of the sensorimotor cortex, vary anatomically in form, length and depth among individuals and present a left/right asymmetry. The purpose of this work was to measure central sulcus's lengths, at the surface and in-depth, in each hemisphere of monozygotic twins in order to evaluate the influence of environmental factors on the morphometry and asymmetry of this structure. A measurement technique on MR images of the brains using 3 D software was developed. Two operators applied this technique to measure central sulcus lengths at the surface of the brain and in-depth in each hemisphere. Besides the fact that the technique developed gave high Intraclass Correlation Coefficients (ICC) for the surface lengths (mean value 0.94), and slightly less high for the in-depth length (mean value 0.87), we found a weak (from 0.57 to 0.73 for raw data) but significant ICC between homologous sulci in pairs of twins. In addition, the ICC for asymmetry indices were not significant. Hence, if central sulcus morphometry is in part genetically influenced, these results show that nongenetic factors are nonetheless important in their development.

Adult↗
PubMed1998

Twin differences and similarities of birthweight and term in the French Romulus population.

This study was performed to examine the main characteristics of the French Romulus twin population: zygosity, chorionicity, sex, term and birthweight. A sample of 104 pairs of twins was distinguished by zygosity, chorionicity and sex, and divided into concordant and discordant birthweight groups. Fifty-three % (n = 55) of the fetus pairs studied were born at "ideal term" (35-38 weeks), and 25% (n = 26) were delivered at "preterm" (28-34 weeks). The very preterm (< 28 weeks), and "postterm" (> 38 weeks) represented altogether 22% (n = 23) of the sample. Of the 104 twin pairs, 68% (n = 71) differ by less than 15% in birthweight, and 32% (n = 33) have a birthweight difference higher than 15%. In dizygotic (DZ) pairs females had more tendency to be in the discordant group (p = 0.01) while in monochorionic-monozygotic (MC-MZ) pairs males were more discordant (p = 0.07). We found a significant interaction between sex and zygosity type (p = 0.02). Males had a birthweight difference significantly weaker than that of females in dichorionic-monozygotic (DC-MZ) and DZ twins whereas it was higher than that of females in MC-MZ twins. There were no MZ twin pairs with DC placentation over than 15% birthweight difference. Log linear analysis demonstrated a three-way interaction (p < 0.05) between term type, zygosity type and hypotrophy. Our data indicate that in the group of twins born between 35 and 38 weeks' gestation the crucial question still remains unsettled on how term and birthweight are related to zygotism and/or chorionicity.

Birth Weight↗
PubMed1998

[Prevention of prematurity in 842 consecutive twin pregnancies].

OBJECTIVE: To evaluate the effects of a specific management in prevention of prematurity in twin pregnancies. METHOD: The parameters involved in obstetrical follow-up of twin pregnancies were evaluated in a retrospective study of 842 twin pregnancies between 1979-1992. RESULTS: Five-hundred-and-fifteen pregnancies were spontaneous. Two-hundred followed treatment with ovulation induction agents and 127 were due to in vitro fertilization. Early diagnosis of twin pregnancies allowed preventive measures against prematurity. Management of twin pregnancies included rest at home and regular clinical examination of the cervix. Monthly consultations and monthly ultrasounds were performed at hospital. Weekly consultations were made by midwives at home. Hospitalization was not systematic, but was necessary in cases of maternal complications. The diagnosis of twin pregnancy was made before 16 weeks in 82.4% of the cases. The mean gestational age at delivery was 36.2 weeks. The prematurity rate was 45.96%. The mean weight of the neonates was 2,376 +/- 533 g for the first twin and 2,297 +/- 547 g for the second twin. The mean Apgar score at 5 minutes was 9.7 and 9.3, respectively for the first and the second twin. The perinatal mortality was 39.3 per 1,000. The main neonatal complications resulted from prematurity. Twins were hospitalized in the intensive care unit in 20.7 cases. CONCLUSION: The present study supports early diagnosis of multiple pregnancies with systematic ultrasound at 11-13 weeks for each pregnancy, information of the patients, rest at home and regular clinical examination of the cervix.

Bed Rest↗
PubMed1998

Are the brains of monozygotic twins similar? A three-dimensional MR study.

PURPOSE: The role of genetic mechanisms and the influence of environmental events in human brain development have been difficult to evaluate. The purpose of this study was to compare the cerebral cortical morphology and midline structures of monozygotic twin pairs using MR imaging. METHODS: Six observers, blinded to twin pairings, evaluated the 3-D renderings of the cortical surface and midline structures from MR images of seven monozygotic twin pairs. A morphometric analysis of the corpus callosum and of the distance between the anterior and posterior commissures was also performed. RESULTS: Despite surprising anatomic differences, the brains of the twin pairs were similar enough to enable the observers to distinguish twin pairs from unrelated subjects. Five of six observers correctly identified the brains of all seven twin pairs; the remaining observer failed to make a correct match in only one of seven pairs. Three of six observers identified the midline sagittal images of the related twins in all seven pairs, and the other three identified the related midline sagittal images in five of seven pairs. The results were statistically significant. CONCLUSION: Although the observed differences in morphologic characteristics between twins necessarily reflect nongenetic influences, the cortical patterns and midline structures of monozygotic twins probably are genetically similar.

Adult↗
PubMed1997

Twin zygosity diagnosis by mailed questionnaire below age twelve months. Le Groupe Romulus.

Parents of a sample of 76 same sexed pairs of twins aged 3 to 9 months completed a mailed similarity questionnaire. It included the Bonnelykke et al.'s questionnaire and a four anthropological variable scale. To improve each of these two methods, three other combined methods were carried out and results were compared with the biological zygosity diagnosis. The Bonnelykke et al.'s classification combined with anthropological scale (method 4) gave only 1.2% misclassified in the whole sample. It is concluded that zygosity diagnosis using this type of procedure to distinguish MZ and DZ pairs would be important not only for epidemiological study but also for pediatricians and parents.

Humans↗
PubMed1997

Biparietal diameter in twins at gestational weeks 18-32. Differences and similarities. Le Groupe Romulus.

OBJECTIVE: To examine twin similarities on biparietal diameter (BPD) measurements by zygosity (monozygotic [MZ] and dizygotic [DZ]) and chorionicity (monochorionic [MC] and dichorionic [DC]) and their evolution during pregnancy. METHOD: A sample of 54 pairs of twins (43 DZ sets, 11 MZ sets [7 MC and 4 DC]) was constructed using retrospective data. Despite the small sample size, our data were complete, and, for the first time we measured different fetal parameters on digital ultrasound images outside routine examination. The intraexaminer and interexaminer reliability of BPD measurement was significant (r = .95, P < .001). RESULTS: In this study, developmental results indicate significant linear regression coefficient (R) through the whole period of gestation (r = .96, P < .001), though product moment correlations comparing the periods of gestation two by two are weaker. The distribution of BPD values was slightly wider at the 28th week and markedly wider at the 32nd week than that at the 18th and 23rd weeks. The intraclass correlations of DZ and MZ (MC and DC) twins were examined at the 18th, 23rd, 28th and 32nd weeks of amenorhea. The intraclass correlations of DZ twins were significant through the whole period of gestation (r = .45, P = .001; r = .27, P = .04; r = .36, P = .008; and r = .42, P = .002, respectively), whereas the intraclass correlations of MZ twins were significant only at the 18th, 23rd and 28th weeks (r = .73, P = .002; r = .69, P = .005; r = .49, P = .047, respectively). We found significant within-variance differences not only between DZ and DC-MZ but also between DC-MZ and MC-MZ in late gestation. CONCLUSION: Our analysis of twin BPD development demonstrated that zygosity and chorionicity type are both important determinants of twin fetal development.

Biometry↗
PubMed1993

Is a dot-filling group test a good tool for assessing manual performance in children?

A dot-filling test was used to assess hand performance in two populations of French children. In the first experiment, the effect of sex, age and handedness on hand performance was examined (1742 children). Age was related to the degree of laterality, but girls were less lateralized than boys. The second experiment (200 children) showed that the surprising sex differences cannot be explained by the group testing procedure. Underlying processes leading to performance in the dot-filling task are probably different from those involved in other tests generally used for children.

Adolescent↗
PubMed1990

Antisocial behaviour and postnatal environment: a French adoption study.

The higher rate of antisocial behaviour in children from lower class environments has been hypothesized as arising from (a) genetic social class differences and/or (b) cultural/environmental disadvantages. The present study aims to evaluate the strength of the incidence of social class on adolescent antisocial behaviour. To separate genetic factors and the prenatal environment from postnatal rearing conditions, 77 children relinquished at birth and adopted before the age of 3 were studied. Using the Rutter "Children's Behaviour Questionnaire for Completion by Teachers", eight antisocial behaviours were assessed when subjects were in late adolescence. With the exception of theft and bullying, results indicate that the higher the adoptive parental social class, the lower the antisocial behaviour rates in the adoptees. It is shown that the relationship between the total score of adoptees' antisocial behaviour and social class cannot be attributed exclusively to a concentration of these behaviours in the lowest class. No significant selective placement was observed. Concordances and discrepancies with previous studies are discussed.

Adolescent↗