Search PubMed⌕ Search

Biomedical subjects

M P Vazquez

Publications and source records attributed to M P Vazquez.

At least 19 recordsLinked to original sources
PubMed2001

Pierre Robin sequence and interstitial deletion 2q32.3-q33.2.

Pierre Robin sequence (PRS) consists of the nonrandom association of micrognathia, cleft palate (CP), and glossoptosis. It also includes respiratory and feeding difficulties that appear to be neurogenic rather than mechanical in causation. Genetic determinants are thought to underlie this functional and morphological entity, based on the existence of Mendelian syndromes with PRS, and the rare observations of familial nonsyndromic PRS, in which some of the affected individuals have isolated CP. We report the association of PRS with deletion 2q32.3-q33.2 due to an unbalanced reciprocal translocation 46,XX, t(2;21), del 2(q32.3q33.2), and we refine the deletion interval with regard to YAC probes and polymorphic DNA markers. The deletion was shown to be flanked by D2S369 (telomeric) and D2S315 (centromeric), thus it maps to a recently determined chromosomal region known to be nonrandomly associated with CP. This observation supports the hypothesis for the genetic bases of nonsyndromic PRS, strengthens its possible genetic association with isolated CP, and provides a candidate PRS locus, in chromosomal region 2q32.3-q33.2.

Chromosome Banding↗
PubMed2001

[Mandibular advancement: osteotomy or distraction osteogenesis? A case report].

From an experience in osteogenic distraction techniques acquired since 1993 and facing a case of retromandible, the authors have tried to define the criteria leading them to suggest a distraction rather a classical surgical procedure. The selection of the patient is based upon the age, the significance of the advancement, the asymmetry of the advancement and the former existence of a temporomandibular joint degenerative disease. Monitoring the distraction, in particular with per- and post-distraction orthodontics, remains complicated. The overcorrection and the reduction of recurrences after advancement using distraction remain openly discussed.

Adolescent↗
PubMed2001

Analysis of the methylation status of the KCNQ1OT and H19 genes in leukocyte DNA for the diagnosis and prognosis of Beckwith-Wiedemann syndrome.

Beckwith-Wiedemann syndrome (BWS) is an overgrowth disorder involving developmental abnormalities, tissue and organ hyperplasia and an increased risk of embryonal tumours (most commonly Wilms tumour). This multigenic disorder is caused by dysregulation of the expression of imprinted genes in the 11p15 chromosomal region. Molecular diagnosis of BWS is currently difficult, mostly due to the large spectrum of genetic and epigenetic abnormalities. The other difficulty in managing BWS is the identification of patients at risk of tumour. An imprinted antisense transcript within KCNQ1, called KCNQ1OT (also known as LIT1), was recently shown to be normally expressed from the paternal allele. A loss of imprinting of the KCNQ1OT gene, associated with the loss of maternal allele-specific methylation of the differentially methylated region KvDMR1 has been described in BWS patients. The principal aim of this study was to evaluate the usefulness of KvDMR1 methylation analysis of leukocyte DNA for the diagnosis of BWS. The allelic status of the 11p15 region and the methylation status of the KCNQ1OT and H19 genes were investigated in leukocyte DNA from 97 patients referred for BWS and classified into two groups according to clinical data: complete BWS (CBWS) (n=61) and incomplete BWS (IBWS) (n=36). Fifty-eight (60%) patients (39/61 CBWS and 19/36 IBWS) displayed abnormal demethylation of KvDMR1. In 11 of the 56 informative cases, demethylation of KvDMR1 was related to 11p15 uniparental disomy (UPD) (nine CBWS and two IBWS). Thirteen of the 39 patients with normal methylation of KvDMR1 displayed hypermethylation of the H19 gene. These 13 patients included two siblings with 11p15 trisomy. These results show that analysis of the methylation status of KvDMR1 and the H19 gene in leukocyte DNA is useful in the diagnosis of 11p15-related overgrowth syndromes, resulting in the diagnosis of BWS in more than 70% of investigated patients. We also evaluated clinical and molecular features as prognostic factors for tumour and showed that mosaicism for 11p15 UPD and hypermethylation of the H19 gene in blood cells were associated with an increased risk of tumour.

Adolescent↗
PubMed2001

"Distraction" of grafted alveolar bone in cleft case using endosseous implant.

OBJECTIVE: Presentation of a specific surgical technique of vertical alveolar ridge distraction performed on an alveolar bone graft 1 year after the primary grafting procedure designed to correct a labioalveolar cleft. The graft had not obtained the results desired and presented heavily scarred mucosal tissue. TECHNIQUE: A dental implant placed within the graft once it has been entirely freed by osteotomies functions as an endless screw. To avoid vascular risk, the alveolar bone graft is detached as a whole along its total height. Consequently, no bone remains above it to provide support for a conventional alveolar distractor. An osteosynthetic miniplate, fastened in a horizontal position beneath the nasal mucosae above the graft, is used to replace the missing bony support and to stabilize the implant, which activates the distraction process. PATIENT: This study is based on our first clinical case with a follow-up of 18 months at present. RESULT: A vertical displacement of the entire graft was achieved, including its attached mucosal layer, which repositioned both bone and mucosa on a far better level in the cleft area. Thus, a normal length of abutment was obtained permitting prosthetic rehabilitation based on the same endosseous implant, which was left in place within the graft. CONCLUSION: This technique may prove particularly helpful in certain cases in which a primary alveolar bone grafting procedure has produced borderline results. In such cases, on the one hand, neither the reasonably satisfactory volume of the bone graft itself nor the poor quality of its scarred mucosal tissue argue in favor of a secondary grafting procedure. On the other hand, it is impossible to resort to currently available alveolar distracters since our choice of techniques leaves no bone support above the graft.

Adolescent↗
PubMed2001

[The Wiedemann-Beckwith syndrome and a congenital cataract].

Wiedemann-Beckwith syndrome is a congenital syndrome with characteristic abnormalities: omphalocele, macroglossia, neonatal gigantism, visceromegaly, hemihypertrophy and a predisposition to embryonic tumors. Ophthalmologic abnormalities have not been described with Wiedemann-Beckwith syndrome. The authors report one case of Wiedemann-Beckwith syndrome associated with bilateral congenital cataract. Family studies indicate linkage of the Wiedemann-Beckwith syndrome locus to the marker 11p15,5. The genetics of cataract is heterogenic. Several mutations responsible for congenital cataract have been described. The association of the Wiedemann-Beckwith syndrome and cataract may contribute to the understanding of the genetics of congenital cataract.

Beckwith-Wiedemann Syndrome↗
PubMed2000

Neurophysiological brainstem investigations in isolated Pierre Robin sequence.

Polysomnography, electromyography (EMG) of the face, tongue, and soft palate, blink reflexes (BRs), EMG during bottle-feeding, and brainstem auditory evoked responses (BAERs) were performed in 25 newborn babies with isolated Pierre Robin sequence (PRS) to aid in evaluation and management. Obstructive apneas were found in 23/24 patients (the 25th having undergone tracheotomy). Number and duration of central respiratory pauses were always normal, as well as electroencephalographic and clinical organization of sleep stages. EMG recruitment pattern in facial and lingual muscles, and BRs were normal in all cases. EMG recruitment pattern in muscles of the soft palate was normal in 14/25 patients, showed a reduced average amplitude with short-duration and low amplitude motor unit potentials in 10/25, and showed signs of denervation in 1/25. EMG during bottle-feeding showed sucking-swallowing disorders in 20/25 patients. BAERs showed a bilateral conductive impairment with increased latencies and thresholds in 5/19 patients, but with normal and symmetric I-III and I-V interpeak latencies in 19/19. These neurophysiological findings suggest that in isolated PRS a dysfunction of the lingual and pharyngeal motor organization exists without any structural impairment in brainstem nuclei and pathways.

Blinking↗
PubMed2000

Assessment of p57(KIP2) gene mutation in Beckwith-Wiedemann syndrome.

Beckwith-Wiedemann syndrome (BWS) is an overgrowth disorder involving developmental anomalies, tissue and organ hyperplasia and an increased risk of embryonic tumours (most commonly Wilms' tumour). This multigenic disorder is caused by dysregulation of the expression of imprinted genes in the 11p15 chromosomal region. It may involve paternal uniparental disomy (UPD), loss of imprinting of the IGF2 gene, maternal inherited translocations and trisomy with paternal duplication. Recently, a small proportion of BWS patients has been shown to have a mutation in the paternal imprinted p57(KIP2) gene, which encodes a cyclin-dependent kinase inhibitor and negatively regulates cell proliferation. We screened for p57(KIP2) gene mutations in 21 BWS patients with no 11p15 UPD in leucocyte DNA. All patients had a phenotype typical of BWS. We analysed the entire coding sequence of p57(KIP2), including intron-exon boundaries, by direct sequencing of five PCR-amplified fragments. No mutation was found in the p57(KIP2) gene. Our results are consistent with those of previous studies showing that mutation of p57(KIP2) is infrequent in BWS. Thus, other mechanisms of p57(KIP2) silencing (imprinting errors) and/or other 11p15 genes are probably involved in the pathogenesis of BWS.

Beckwith-Wiedemann Syndrome↗
PubMed1999

Functional analysis of the intergenic regions of TcP2beta gene loci allowed the construction of an improved Trypanosoma cruzi expression vector.

TcP2beta ribosomal protein genes in Trypanosoma cruzi are encoded by four different loci, H6.4, H1.8, H1.5 and H1.3. All loci have a similar organization, except for H1.8 that harbors two TcP2beta genes arranged in tandem and separated by a short repetitive sequence, named SIRE (short interspersed repetitive element), which is also found upstream of the first gene of the tandem and downstream of the second. In this locus the trans-splicing signal of TcP2beta is located within the SIRE element, while in the other loci it is positioned within the first 50bases upstream of the AUG with an AG acceptor site at position -12 respective to the initiation codon. Transient transfection experiments were used to evaluate the efficiency of these two different trans-splicing regions to drive CAT activity. The region named HX1 located upstream the TcP2beta H1. 8 gene was clearly more efficient than the SIRE sequence contained in the region named HX2. Therefore, we decided to use the HX1 region to ameliorate the performance of the cryptic trans-splicing signal present in the T. cruzi expression vector pRIBOTEX (Martinez-Calvillo, S., López, I., Hernandez, H., 1997. pRIBOTEX expression vector: a pTEX derivative for a rapid selection of Trypanosoma cruzi transfectants. Gene 199, 71-76). By insertion of the region HX1 downstream of the ribosomal promoter of pRIBOTEX, we constructed pRHX1CAT40 that, in stable transfected cells, was able to drive CAT activity 2760 times more efficiently than the control plasmids. Based on this, a novel plasmid vector was conceived, named pTREX-n, which retains the neo gene of pRIBOTEX as a positive selectable marker and replaces the CAT-SV40 cassette in pRHX1CAT40 by a multiple cloning site.

Animals↗
PubMed1999

Linkage analysis of 5 novel van der Woude syndrome kindreds to 1q32-q41 markers further supports locus homogeneity of the disease trait.

van der Woude syndrome (vWS, MIM 119300) is a rare autosomal dominant clefting condition with cardinal features of mucous cysts (lower-lip pits) and clefts to the lip and/or palate. The vWS gene has been assigned to a locus in 1q32-q41 by linkage analysis and physical mapping. We have investigated 5 novel vWS families through probands attended for cleft lip and/or palate repair at the Department of Maxillofacial Surgery of Hôpital Trousseau, Paris, in order to tentatively refine the genetic map of the vWS region in 1q32-q41 and possibly identify unlinked pedigrees. Linkage analysis was carried out to 6 microsatellite markers (D1S249, D1S425, D1S491, D1S205, D1S414, D1S425), yielding a maximum cumulative LOD score of Z = 3.27 at theta = 0.00 for D1S245. The innermost four markers were found to be tightly linked to one another, with no evidence for recombination. Our results support linkage of vWS within a region of tightly linked markers and do not favour locus heterogeneity of the disease trait.

Chromosome Mapping↗
PubMed1999

[Circumscribed mandibular osteitis in children due to hematogenous dissemination. Apropos of 5 clinical cases].

In children, mandibular swelling associated with an X-ray bone osteolysis may correspond to tumoral or infection diseases. Circumscribed osteitis of a child's mandibula, with no dental etiology occurs around 7-years of age, adjacent to a healthy first molar. Five cases reports were analyzed. Clinically, it is a bone swelling of the mandibula's lateral cortical associated with a soft tissue swelling. X-ray signs were not specific but all cases showed a bone lacuna with sharp outlines. Such clinical and X-ray signs strongly suggest diagnosis of osteitis which has a higher incidence than malignant tumors. The lack of dental pathology suggests bloodstream dissemination from another localized sepsis. Surgical removal of pathologic bone in addition to antibiotics (6 or 8 weeks) appears to be an effective treatment.

Amoxicillin↗
PubMed1999

Intraoral mandibular distraction: indications, technique and long-term results.

This report describes the experience of the Trousseau Hospital, Paris, France, with distraction osteogenesis of the mandible using an intraoral distraction device. From 1993 to 1998, 26 paediatric patients with mandibular hypoplasia underwent distraction of the mandible using the Leibinger Intraoral Distractor. The majority of the patients had hemifacial microsomia. Distraction was performed at a rate of 1 mm a day following complete osteotomy of the mandible. A mean of 15 mm of distraction was obtained. In conjunction with combined orthodontic management, satisfactory morphologic results were achieved in the majority of patients with good facial symmetry, adequate occlusal relationships and balanced maxillary mandibular relationships. Radiographic evaluation revealed that substantial new bone formation and remodelling was induced by the intraoral distraction along the entire hemimandible on the distracted side and that this contributed significantly to the aesthetically pleasing clinical results.

Adolescent↗
PubMed1998

Arteriovenous malformations of the dental arcades. The place of endovascular therapy: results in 12 cases are presented.

Twelve arteriovenous malformations of the dental arcades (AVMDAs) (seven mandibular and five maxillary) were seen in our institution between 1977 and 1997. All these lesions consisted of true arteriovenous shunts (of either nidus or fistulous type) involving the bone, with or without soft tissue extension. Haemorrhage was present in eight patients (67%); either torrential, necessitating emergency embolization, or recurrent and progressive. Teeth instability was detected in all patients and was the origin of the bleeding. All lesions were embolized. Lesions in nine patients were embolized with Polyvinyl Alcohol Particles (PVA): this helped to stabilize the situation but could not avoid recurrences in all patients, necessitating complementary embolizations and or surgery. The use of acrylic glue (N-Butyl-Cyano-Acrylate [NBCA] Histoacryl) as the embolic agent has changed the results obtained tremendously. Eight patients have been treated with NBCA (five as complementary therapy to PVA during later sessions and three at the first attempt); injection either via the transarterial route or direct transcutaneous puncture (four patients) achieved a cure in four of these lesions (34%) with stability at long-term follow-up of all the other AVMs. Embolization with glue represents the therapy of choice in these sometimes life-threatening lesions, achieving a cure if directed towards the osseous venous lakes. Surgery, often leading to facial mutilation and necessitating massive reconstruction should be avoided nowadays, at least as the initial therapy.

Adolescent↗
PubMed1997

The Beckwith-Wiedemann syndrome phenotype and the risk of cancer.

Beckwith-Wiedemann syndrome (BWS) comprises of a number of childhood abnormalities, often associated with one or more tumors. Thirty-eight patients were investigated to determine clinical and/or biological signs associated with a tumor presence. Our patients exhibited a higher incidence of tumor development (21%) than that previously reported, underlying the care with which such patients should be followed, when particular clinical features are observed: visceromegaly affecting three organs (liver, kidney, spleen), and also family history with sign of BWS such as macroglossia, omphalocele, hemihypertrophy, embryonic tumor), high body weight at birth (> or = +2 standard deviations and diastasis recti.

Beckwith-Wiedemann Syndrome↗
PubMed1997

Submerged intraoral device for mandibular lengthening.

The authors report a new technique for mandibular distraction. Lengthening of the mandible by gradual intraoral distraction was obtained in nine young patients. An intraoral device was used in order to avoid external scars. Seven patients had hemifacial microsomia, one patient had a ramus hypoplasia after TMJ ankylosis and one patient had the Treacher-Collins syndrome. The amount of mandibular lengthening ranged from 12 to 28 mm depending on the duration of expansion. Retention after expansion, to allow ossification to take place, lasted for 3 weeks on average. The follow-up period ranged from a minimum of 5 months to a maximum of 44 months.

Ankylosis↗
PubMed1997

[Mandibular distraction].

The authors review the bone lengthening techniques used in orthopaedics, analyse the application of osteogenesis by surgical distraction of the mandible and describe the progress in techniques and equipment. The presentation of clinical cases of mandibular hypoplasia treated by intraoral distraction emphasizes the value of this new technique, particularly in terms of the morphological results, which are superior to those obtained by conventional techniques.

Child↗