Biomedical subjects

F Perez-Diaz

Publications and source records attributed to F Perez-Diaz.

29 records · Page 2Linked to original sources

PubMed1998

Quantitative trait loci implicated in corpus callosum midsagittal area in mice.

The midsagittal area of the corpus callosum expressed as the percentage of the hemispheric surface is smaller in the NZB/BlNJ than in the C57BL/6By inbred strain of mice. We performed a QTL mapping analysis using 284 F2s. Two loci linked to this measure were found: the CCrSQTL1 and CCrSQTL2 at 87 and 67 centiMorgans from the centromere on chromosomes 1 and 4 respectively. The two loci interacted significantly. The total source of genetic variation contributed to 25% of the observed variance.

Animals↗

PubMed1998

Age at onset and gender resemblance in bipolar siblings.

In order to measure the intrafamilial correlation for age at onset and to examine gender resemblance among bipolar siblings, we assessed a sample of 130 bipolar patients belonging to 59 multiple affected sibships. To study the intrafamilial resemblance for age at onset and gender, we used the intraclass correlation and the sibship method, respectively. Within the whole sample, age at onset for affected siblings was correlated (rho = 0.42, P = 0.0001). Gender was randomly distributed among bipolar sibships, demonstrating the absence of gender resemblance among affected siblings. The existence of an intrafamilial correlation for age at onset among bipolar siblings suggests that this variable may assist in the identification of more heritable forms of the illness. No intrafamilial correlation was found for the gender of affected siblings, suggesting that familial vulnerability factors are not gender-specific.

Adolescent↗

PubMed1996

Vocalizations in newborn mice: genetic analysis.

Two kinds of vocalizations are produced by newborn mice: whistles (between 50 and 150 ms in length), having a narrow bandwidth in each strain that ranges from 30 to 90 kHz; and clicks, which are shorter (about 1 ms) and have a larger bandwidth. These vocalizations were individually recorded in 1-day-old pups from seven inbred strains of laboratory mice, at two temperatures (23 +/- 0.5 and 15 +/- 0.5 degrees C). The numbers of clicks and whistles were counted under these two conditions. Moreover, the length and frequencies at the beginning, apex, and end of the whistles were measured during the 15 degrees C condition. Correlations, including several components-additivity, epistasis (between homozygous loci), and maternal environment-were calculated between the characteristics of the whistles during the 15 degrees C condition. Clicks and whistles were also counted from 1 to 8 days of age during the 15 degrees C condition. The numbers of clicks and whistles were age dependent, with a decrease from day 1 to day 8 for the clicks and a consistent production of whistles. A quantitative genetic analysis was also performed on the 1-day-old pups from the Mendelian generations produced by the inbred strains most contrasting for the number of whistles produced in the cold condition: NZB/BINJ and CBA/H. The heterozygous genotype of the mother induced an increment of the number of whistles. Moreover, a significant part of the additive variance was suspected from the first design, and found with the second one, for this variable. Quantitative genetic analysis showed significant dominance and epistasis between homozygous loci and homozygous and heterozygous loci. This points to multigenic correlates for the number of whistles in this population. The significant additive values for all the variables recorded during the 15 +/- 0.5 degrees C condition and for the number of whistles produced during the 23 +/- 0.5 degrees C condition are compatible with an effect that indicates neither directional nor stabilizing selection. This result is examined in the light of the multichannel sensorial process implicated in maternal behavior in mice.

Animals↗

PubMed1995

Genetic analysis of the relationships between behavioral and neuroendocrine traits in Roman High and Low Avoidance rat lines.

In order to determine whether the coselection observed between the selection trait (active avoidance behavior) of the Roman High Avoidance (RHA) and Roman Low Avoidance (RLA) rat lines and their neuroendocrine characteristics were genetically determined, we analyzed, in nonsegregating (RHA, RLA, and F1) and segregating (F2 and the two backcrosses) crosses, the inheritance pattern and the phenotypic correlations among behavioral (shuttle-box behavior), physiological (body, adrenal, and thymus weights), and neuroendocrine (corticosterone and prolactin reactivity, catecholamine enzyme activities) variables. Physiological characteristics and enzyme activities have a crucial role in sex dissociation. Avoidance behavior and prolactin reactivity to novel environment remained associated in segregating crosses despite gene rearrangement. They represented the most important variables to differentiate the Roman lines, perhaps sharing a common regulatory mechanism under genetic control.

Animals↗

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↗

PubMed1991

Handedness in mice: comparison across eleven inbred strains.

Screening for handedness was performed in 11 inbred strains of mice. Direction and degree of handedness were measured for both males and females in each strain. The data show that there are almost as many right- as left-handed subjects and no strain could be classified as right- or left-handed. Females, however, tend to be more strongly lateralized than males. The range of variation for degree of handedness is pronounced between strains. These results thus suggest that degree of handedness would be the relevant variable in a genetic analysis of handedness in mice. They are in agreement with Collins' previous results showing a response to selection for degree, but not for direction, of handedness.

Animals↗

PubMed1991

An assessment of handedness in mice.

Mice from a pool of inbred strains (384 males and 329 females) were tested for handedness according to Collins' protocol in order to assess the reliability of this measurement. As previously reported by Collins these data revealed that a) approximately half of the mice were right-handed and half left-handed, b) most of the mice were strongly lateralized and c) females were more lateralized than males. The study of the psychometric characteristics of the test suggested that this measurement of behavioral asymmetry is both stable and observer independent. The test of paw preference also appeared to measure preexisting lateralization and was not a function of training during the test.

Animals↗

PubMedDate not supplied

[Alexithymia, depression and drug addiction].

Alexithymia is a multidimensional concept associating an emotional component focused on the difficulty in identifying and describing feelings and a cognitive one centred on the use of a concrete and poorly introspective way of thinking. Alexithymia can be assessed by self-assessment instruments and in particular by the 20 items version of the Toronto Alexithymia Scale (TAS-20). Depressive disorders have complex relationships with the construct of alexithymia and there exist few experimental works on the subject. Epidemiological studies frequently raise an overlap between alexithymia and depression, in particular in the context of addiction. The main aim of this study was to confirm the high prevalence of alexithymia among drug addicted patients taking into account socio-demographic variables (sex, age, social and economic categories). The second aim of the study was to investigate the relationships between alexithymia and depression among drug addicted patients. A sample of 128 drug addicted patients answering DSM IV criteria of dependence to a psycho-active substance (alcohol excluded) was paired according to socio-demographic variables to a control sample of 128 normal subjects. Diagnostic assessment was made using the Mini International Neuropsychiatric Interview (MINI). Alexithymia and depression were assessed with the TAS-20 and with the short version of the Beck Depression Inventory (BDI-13). The results confirm the high prevalence of alexithymia among drug addicted patients (43.5%) compared to controls (24.6%). This difference is based namely on the emotional component of alexithymia, the cognitive component failing to show any difference between the two samples. Moreover, alexithymia appears to be independent from socio-demographic variables in our sample of drug addicted patients; 66.4% of drug addicted patients presents a depressive symptomatology (which is significantly more important in female patients), compared to 26% of the controls. Studies using the TAS and the BDI with 21 items have shown that from 10 to 20% of the variance of alexithymia is explained by depression. Our own results show a shared variance of 20% between the TAS-20 and the BDI, going in the direction of a moderated correlation between alexithymia and depressive symptomatology. Moreover, when we retain only subjects without depressive symptomatology at BDI, drug addicted (n=42) are not any more alexithymic than controls (n=114). Our results plead for a positive association between depression and alexithymia in drug addicted, depressed or healthy subjects. Alexithymia and depression would be two associated dimensions, the emotional component explaining alone this association. The emotional component of the alexithymia would be thymo-dependent, whereas the cognitive component (externally oriented thought) would be independent and constitute a stable clinical feature. These results are concordant with other studies in the literature suggesting that alexithymia in its emotional component is supported by depression. Alexithymia thus did not appear as an autonomous dimension which would discriminate between drug addicted and controls, independently of the absence of a depressive state. The Authors discuss the complexity of the relationships between alexithymia and depression and the correlations between TAS and BDI scales especially for the factor Difficulty Identifying Feelings. These results deserve further studies. The cross-sectional nature of this study do not allow to establish if alexithymia is a subjacent and preexistent in the form of a psychopathological dimension in addictive behaviours, so supporting its emergence, and/or if it develops once the dependence is installed and chronicized. Longitudinal studies remain to be realised.

Adult↗

PubMedDate not supplied

[Is age at onset associated with executive dysfunction in obsessive-compulsive disorder?].

In obsessive-compulsive disorder (OCD), clinical, neurobiological and genetic differences have been reported according to age at onset (AAO). Given the importance of identifying homogeneous subtypes in complex hete-rogeneous disorders such as OCD, it would be particularly useful to identify a specific cognitive profile associated with early-onset OCD. Although impaired cognition has repea-tedly been demonstrated in OCD patients, discrepancies between studies have hampered the identification of a precise cognitive dysfunction. Executive dysfunction has often been reported, but findings have not always been replicated. The aim of this study was to assess executive functions in 30 patients according to their AAO. The sample consisted of 15 early-onset and 15 late-onset OCD patients and 22 normal controls, matched for age, sex and socio-economic status. Various aspects of executive function were assessed with five neuropsychological tests: Tower of London, Trail Making Test, Verbal Fluency, Design Fluency and Association Fluen-cy. The 30 OCD patients obtained lower total scores than the controls in the Tower of London test and association fluen-cy task (p<0.05 and p<0.001, respectively). Impairments were more marked for the early-onset group, with no effect of gender or age at interview. Deficits in specific aspects of frontal lobe function were found in the OCD group and were particularly pronounced within the early-onset group. These findings confirm clinical data suggesting that OCD patients can be subtyped according to age at onset and that OCD patients present unusual cognitive characteristics. They also support the hypothesis that early-onset OCD might be a rele-vant subgroup characterised both by a particular clinical profile and by specific cognitive characteristics.

Adolescent↗

PubMedDate not supplied

Locomotor and exploratory activity in three inbred strains of mice from young adulthood to senescence.

Nine variables measuring activity and exploratory behavior were collected for nine independent groups of three inbred strains of mice (BALB/c, C57BL/6, and DBA/2) at three ages (150, 400, and 750 days). An analysis of variance measuring differences of performances and a covariance analysis estimating the evolution of scores with age shows that (1) some variables are unaffected by age; (2) a strain-age interaction is observed for some variables; (3) some groups do not exhibit any age-related change for certain variables; and (4) the level of ability of age-related behavior varies across groups. These data argue for rejection of a general factor of aging and suggest that we are dealing with two distinct phenotypes: performance, and age-related modification of the performance, which therefore are not linked.

Aging↗

PubMedDate not supplied

Psychometric normalization of a hyperacusis questionnaire.

Clinical hyperacusis consists of a marked intolerance to ordinary environmental sounds, while hearing thresholds are quite often normal. Hyperacusis appears to be a subjective phenomenon, which is not easily defined or quantified by objective measurements. In order to create a tool suitable to quantify and evaluate various hyperacusis symptoms, a questionnaire screening several aspects of auditory symptomatology has been constructed. Two hundred and one subjects (who were either hyperacusic or not), randomly selected from the general population, were tested. A principal component analysis performed on the correlation matrix of the 14 items of the questionnaire isolated three dimensions: attentional, social, and emotional. The three dimensions had satisfactory internal consistency reliability. The mean +/- SD total score was 15 +/- 6.7 out of 42 (maximum of hyperacusis) and a score greater than 28 seems to represent a strong auditory hypersensitivity. This new psychometric tool should further be tested on hyperacusic patients to verify its relevance in pathology and define the involvement of the three dimensions statistically obtained on the hyperacusis symptomatology.

Adolescent↗