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Biomedical subjects

Brigitte Gilbert

Publications and source records attributed to Brigitte Gilbert.

16 recordsLinked to original sources
PubMed2006

Improvement of episodic memory in persons with mild cognitive impairment and healthy older adults: evidence from a cognitive intervention program.

The efficacy of cognitive training was assessed in persons with mild cognitive impairment (MCI) and persons with normal cognitive aging. Forty-seven participants were included in this study: 28 with MCI and 17 controls. Twenty-one participants received intervention (20 MCI and 9 controls) and 16 participants (8 MCI and 8 controls) received no intervention (waiting-list group). The intervention focused on teaching episodic memory strategies. Three tasks of episodic memory (list recall, face-name association, text memory) were used as primary outcome measures. Results were analyzed using analyses of variance. The intervention effect (pre- and post-intervention difference) was significant on two of the primary outcome measures (delayed list recall and face-name association). A significant pre-post-effect was also found on measures of subjective memory and well-being. There was no improvement in the performance of groups of individuals with MCI and normal elderly persons who did not receive the intervention. These results suggest that persons with MCI can improve their performance on episodic memory when provided with cognitive training.

Aged↗
PubMed2005

Monozygotic twins concordant for blood karyotype, but phenotypically discordant: a case of "mosaic chimerism".

We report on 23 years old discordant monozygotic (MZ) twins, one with minor anomalies and mental delay, the other one being normal. Both had 46,XX,dup(11)(p12p15)/46,XX mosaicism in blood, with a similar proportion of abnormal cells (respectively, 16% and 17%). However, interphase fluorescence in situ hybridization (FISH) analysis performed on buccal smear and urinary sediment using specific probes located at the duplicated region showed that mosaicism was only present in the abnormal twin, with 68% abnormal cells. We hypothesize that the postzygotic chromosomal rearrangement may have occurred early in one embryo after the twinning event, and the blood mosaicism observed in both twins would have resulted from blood exchanges via placental anastomoses. This hypothesis of chimerism is strongly supported by twin-to-twin transfusion syndrome observed during fetal life of our twins. This case and those previously reported lead us to suggest that blood is particularly unsuitable for cytogenetic investigations of twins.

Adult↗
PubMed2005

The 5' region of the MSH2 gene involved in hereditary non-polyposis colorectal cancer contains a high density of recombinogenic sequences.

MSH2 rearrangements are involved in approximately 10% of hereditary non-polyposis colorectal cancer (HNPCC) families, and in most of the rearrangements, exon 1 is deleted. We scanned by quantitative multiplex polymerase chain reaction (PCR) of short fluorescent fragments (QMPSF) 200 kb of genomic sequences upstream of the MSH2 transcription initiation site in 21 HNPCC families with exon 1 deletions. This QMPSF scan revealed 12 distinct 5' breakpoints located up to 200 kb upstream of the MSH2 transcription initiation site. Sequencing analysis of the rearranged allele in 17 families revealed that most of the deletions (15/17) resulted from homologous Alu-mediated recombination. QMPSF and sequencing analysis in these 21 families led us to detect the presence of 20 distinct 5' breakpoints. In 14 out of 15 Alu-mediated recombinations, we found, either within the identical region in which the recombination had probably occurred or in its vicinity, the 26-bp Alu core sequence containing the recombinogenic Chi-like motif. Compared to the equivalent regions of other human genes, the MSH2 upstream region was found to contain a high density of Alu repeats (30% within 228 kb and 43% within 50 kb), most of which belong to the old Alu S subfamilies. In conclusion, this study demonstrates the heterogeneity of the breakpoints within the MSH2 upstream region and reveals the remarkable density of recombinogenic Alu sequences in this region.

Adult↗
PubMed2005

Study of verbal working memory in patients with Parkinson's disease.

The authors examined the nature of the working memory deficit in persons with Parkinson's disease (PD). Three hypotheses were tested: a limited storage capacity, an impaired executive component, and a reduction of psychomotor speed. Verbal working memory was assessed in 14 PD patients without dementia and 14 matched control participants. Participants were administered a classical verbal span test, working memory tasks that required either updating or manipulation capacities, and motor and psychomotor speed tasks. Patients' performance was comparable to that of control participants on the verbal span test. However, results on the working memory tasks indicated a deficit in manipulation with normal updating capacities. Motor and psychomotor slowing were found in the patient group, but slowing could not fully account for the impairment observed in the manipulation task. Results indicated that there is a genuine but selective working memory impairment in patients with PD.

Age Factors↗
PubMed2004

Significant contribution of germline BRCA2 rearrangements in male breast cancer families.

Although screening for large deletions or duplications of the BRCA1 gene is becoming a routine component of the molecular diagnosis of familial breast cancer, little is known about the occurrence of such rearrangements in the BRCA2 gene. Because of the high frequency of BRCA2 mutations in breast cancer families with at least one case of male breast cancer, we selected a cohort of 39 such families, tested negative for mutations in the coding regions of BRCA1 and BRCA2, and developed an assay for BRCA2 rearrangements, based on quantitative multiplex PCR of short fluorescent fragments (QMPSF). We found three rearrangements: (1) a deletion of exons 12 and 13; (2) a duplication of exons 1 and 2; and (3) a complete deletion of BRCA2. We determined the boundaries of the deletion of exons 12 and 13, showing that it resulted from an unequal recombination between Alu sequences. We mapped the complete BRCA2 deletion, which extends over at least 298 kb and showed that it does not affect APRIN/AS3, previously characterized as a tumor suppressor gene, but it comprises several loci corresponding to proven or putative transcripts of unknown functional significance. These data suggest that screening for BRCA2 rearrangements should be done, especially in male breast cancer families tested negative for BRCA1 and BRCA2 mutations.

Breast Neoplasms, Male↗
PubMed2004

Characterization of a novel loss of function mutation of PAX8 in a familial case of congenital hypothyroidism with in-place, normal-sized thyroid.

Thyroid dysgenesis is the most common cause of congenital hypothyroidism, a relatively frequent disease affecting 1 in 3000-4000 newborns. Whereas most cases are sporadic, mutations in transcription factors implicated in thyroid development have been shown to cause a minority of cases transmitted as monogenic Mendelian diseases. PAX8 is one of these transcription factors, and so far, five mutations have been identified in its paired domain in patients with thyroid dysgenesis. We have identified a novel mutation of PAX8, in the heterozygous state, in a father and his two children both presenting with congenital hypothyroidism associated with an in-place thyroid of normal size at birth. In addition, one of the affected siblings displayed unilateral kidney agenesis. The mutation substitutes a highly conserved serine in position 54 of the DNA-binding domain of the protein (S54G mutation) by a glycine. Functional analyses of the mutant protein (PAX8-S54G) demonstrated that it is unable to bind a specific cis-element of the thyroperoxidase gene promoter in EMSAs and that it has almost completely lost the ability to act in synergy with Titf1 to transactivate transcription from the thyroglobulin promoter/enhancer. These results indicate that loss of function mutations of the PAX8 gene may cause congenital hypothyroidism in the absence of thyroid hypoplasia.

Amino Acid Sequence↗
PubMed2004

Oculo-ectodermal syndrome: a new tumour predisposition syndrome.

We report a new case of oculo-ectodermal syndrome who developed giant cell granulomas of the jaw, similar to the patient previously described by Toriello et al. (1999). We review reported cases to better delineate the clinical spectrum of this rare condition. Giant cell granulomas developing in childhood seem to be part of the oculo-ectodermal syndrome. This condition appears to be a new tumour predisposition syndrome.

Alopecia↗
PubMed2003

Temporal preparation strategy may inflate RT deficit in patients with Parkinson's disease.

Twelve patients with Parkinson's disease (PD) and 12 age-matched controls completed a visual reaction time (RT) task to assess the effect of temporal parameters on response preparation. Simple and choice RT conditions were presented in separate blocks. In both conditions, preparatory intervals of various durations (1, 3 and 5 s) were introduced between an auditory warning signal and the visual target. Within a block of trials, intervals varied randomly. The results indicated that PD patients responded slower than controls in both task conditions. Also, there was evidence for preparation in both groups, as RT decreased with increasing intervals. A three-way interaction indicated that PD patients' RT was longer than that of controls at the shortest interval in simple RT. This suggests that PD patients show a different pattern of temporal response preparation and that this may contribute to their deficit on RT tasks.

Acoustic Stimulation↗
PubMed2002

Significant contribution of large BRCA1 gene rearrangements in 120 French breast and ovarian cancer families.

Genetic linkage data have shown that alterations of the BRCA1 gene are responsible for the majority of hereditary breast-ovarian cancers. However, BRCA1 germline mutations are found much less frequently than expected, especially as standard PCR-based mutation detection approaches focus on point and small gene alterations. In order to estimate the contribution of large gene rearrangements to the BRCA1 mutation spectrum, we have extensively analysed a series of 120 French breast-ovarian cancer cases. Thirty-eight were previously found carrier of a BRCA1 point mutation, 14 of a BRCA2 point mutation and one case has previously been reported as carrier of a large BRCA1 deletion. The remaining 67 cases were studied using the BRCA1 bar code approach on combed DNA which allows a panoramic view of the BRCA1 region. Three additional rearrangements were detected: a recurrent 23.8 kb deletion of exons 8-13, a 17.2 kb duplication of exons 3-8 and a 8.6 kb duplication of exons 18-20. Thus, in our series, BRCA1 large rearrangements accounted for 3.3% (4/120) of breast-ovarian cancer cases and 9.5% (4/42) of the BRCA1 gene mutation spectrum, suggesting that their screening is an important step that should be now systematically included in genetic testing surveys.

Adult↗
PubMed2002

Familial isolated congenital asplenia: a rare, frequently hereditary dominant condition, often detected too late as a cause of overwhelming pneumococcal sepsis. Report of a new case and review of 31 others.

UNLABELLED: Congenital isolated asplenia may arise as a minor form of situs abnormalities or result from an unrelated specific defect of spleen development. It is a rare life-threatening condition and pneumococcal sepsis is often the first sign of the disease. We report on the case of a deceased 11-month-old girl and her father who developed recurrent pneumococcal meningitis. The fatal evolution in the girl was due to Streptococcus pneumoniae serotype 23 with intermediate penicillin sensitivity 4 h after amoxicillin (100 mg/kg i.v.) administration. Establishing the diagnosis of congenital isolated asplenia in the case of pneumococcal sepsis can be achieved by performing two easy and non-invasive investigations: searching for Howell-Jolly bodies on blood smears and performing ultrasound examination of the abdomen to look for the spleen. In the case of congenital isolated asplenia, use of appropriate prophylaxis could save the lives of affected children. Our review of the literature yielded 31 cases of congenital isolated asplenia. Thirteen were sporadic and 18 were familial cases involving eight families. CONCLUSION: in the case of Streptococcus pneumoniae sepsis, a systematic search for Howell-Jolly bodies on blood smears and ultrasound examination of the abdomen for the presence of asplenia should be mandatory to detect isolated congenital asplenia. If asplenia is found, potentially life-saving antibiotic prophylaxis and pneumococcal vaccination should be initiated.

Anti-Bacterial Agents↗
PubMed2002

How loss of meaning with preservation of phonological word form affects immediate serial recall performance: a linguistic account.

We present HP, a patient who following the occurrence of herpes simplex encephalitis, lost the ability to understand a subset of words while others remained preserved. Of particular interest is the fact that the meaningless items retained their lexical status. HP's immediate serial recall of meaningless words was thus compared with that of meaningful words to assess the unique contribution of semantic knowledge without the confounding influence of phonological word (lexical) form. The results revealed a clear recall advantage for meaningful over meaningless words, indicating a specific contribution to recall from the semantic level of representation. Furthermore, an error analysis showed that phonemic errors were most common when semantic information was lacking. Interestingly, the same error pattern was found for pseudo-words that shared phonological elements with meaningless words. These findings support a linguistic and interactive activation account of short-term serial recall, which assumes that all levels of representation, including semantic knowledge about words, contribute to recall performance. In addition, the findings provide preliminary evidence that this view may be extended to the recall of pseudo-words, as there appear to be some influences of semantic representation on pseudo-word recall.

Adult↗
PubMedDate not supplied

"Cri-du-chat" syndrome in a patient born to a mother with a paracentric inversion of chromosome 5q.

We report the case of a female child presented at birth with hypotonia, growth retardation and respiratory distress. Chromosome study from peripheral blood showed a 46,XX,del(5)(p14pter) karyotype. Parental chromosome studies revealed that the mother carried an apparently balanced paracentric inversion of long arms of one chromosome 5, giving the karyotype 46,XX,inv(5)(q12q32), whereas paternal karyotype was normal. The maternal abnormality was confirmed by fluorescence in situ hybridization (FISH) and was not present in the daughter's metaphases. Microsatellite analysis in the proposita and her parents permitted us to conclude that the deleted chromosome 5 was paternal in origin, as usually described. Therefore, as might have been expected, maternal paracentric inversion of chromosome 5q and "cri-du-chat syndrome" presented by the daughter were not related.

Adult↗
PubMedDate not supplied

Value of microsatellite instability typing in detecting hereditary non-polyposis colorectal cancer. A prospective multicentric study by the Association Aquitaine Gastro.

AIM OF THE STUDY: To detect hereditary non-polyposis colorectal cancer (HNPCC) patients with a strategy combining clinical selection (patient age at onset of cancer less than 50 years or family history of HNPCC tumors) and microsatellite instability typing plus immunohistochemistry, leading to mismatch repair (MMR) germline mutation analysis. METHODS: Tumors were screened for microsatellite instability (MSI) and for hmlh1 and hmsh2 immunohistochemical expression. Germline mutation analysis was performed to search for MLH1 and MSH2 mutations in patients with MSI-High and MSI-Low tumors. RESULTS: 197 adenocarcinomas were studied: 164 patients were< or =50 years old, 33 were older than 50 years but had a family history of HNPCC tumors. Fifty tumors (25.4%) were MSI-High, 10 were MSI-Low (5.1%), and 130 were MS-Stable (66%). MSI typing was inconclusive in 7 (3.5%). Immunohistochemistry screening was performed on 165 tumors: sensitivity was 63.6%, specificity was 99%. Germline mutation analysis was performed in 33/60 MSI-High or Low tumors: 23 mutations were noted (70% of the tested patients). CONCLUSION: This proposed strategy of determining microsatellite instability in young colorectal cancer patients or in patients with a family history of HNPCC tumors led to an increased frequency in the detection of MMR germline mutations.

Adenocarcinoma↗