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Biomedical subjects

J Melki

Publications and source records attributed to J Melki.

At least 55 records · Page 3Linked to original sources
PubMed1994

Acute pancreatitis after carbamate insecticide intoxication.

A 29-year-old woman was admitted to the Rouen University Hospital for attempted suicide by ingestion of a carbamate insecticide (Temik G, containing 10% aldicarb). Cardio-respiratory arrest occurred at the second hour and acute necrotic hemorrhagic pancreatitis on the second day. Further evolution was uneventful, and the patient was discharged after 43 days. Carbamate intoxication was confirmed by high urinary aldicarb metabolite concentrations. Pseudocholinesterase levels took 77 days to return to normal. Carbamate pesticides share the same pancreatic risk as organophosphorus pesticides, and should be monitored similarly.

Acute Disease↗
PubMed1994

Linkage of a new locus for autosomal dominant familial spastic paraplegia to chromosome 2p.

Autosomal dominant familial spastic paraplegia (AD-FSP) is a genetically heterogeneous neurodegenerative disorder characterized by a spasticity of the lower limbs. A locus causing AD-FSP (FSP1) has been previously mapped to chromosome 14q. We now report linkage of a second AD-FSP locus (FSP2) to chromosome 2p21-p24 in five of seven French families and one large Dutch pedigree. The analysis of recombination events and multipoint linkage place FSP2 within a 4 cM interval flanked by loci D2S400 and D2S367.

Adolescent↗
PubMed1994

[Physical study of big fragments and search strategy of genes. Application to locus of infant spinal muscular atrophies].

Spinal muscular atrophies (SMA) represent the second most common fatal autosomal recessive disorder after cystic fibrosis. Childhood SMAs are divided into severe (type I) and mild forms (types II and III). By a combination of genetic and physical mapping, a YAC contig of the 5q13 region spanning the disease locus was constructed that showed the presence of low copy-repeats in this region. Allele segregation was analyzed at the closest genetic loci detected by markers C212 and C272 in 201 SMA families. Inherited and de novo deletions were observed in 10 SMA patients. Moreover, deletions were strongly suggested in at least 18% of SMA type I patients by the observation of marked heterozygosity deficiency for the loci studied. These results indicate that deletion events are statistically associated with the severe form of SMA.

Chromosome Mapping↗
PubMed1994

Genetic homogeneity of Pelizaeus-Merzbacher disease: tight linkage to the proteolipoprotein locus in 16 affected families. PMD Clinical Group.

Among the numerous leukodystrophies that have an early onset and no biochemical markers, Pelizaeus-Merzbacher disease (PMD) is one that can be identified using strict clinical criteria and demonstrating an abnormal formation of myelin that is restricted to the CNS in electrophysiological studies and brain magnetic resonance imaging (MRI). In PMD, 12 different base substitutions and one total deletion of the genomic region containing the PLP gene have been reported, but, despite extensive analysis, PLP exon mutations have been found in only 10%-25% of the families analyzed. To test the genetic homogeneity of this disease, we have carried out linkage analysis with polymorphic markers of the PLP genomic region in 16 families selected on strict diagnostic criteria of PMD. We observed a tight linkage of the PMD locus with markers of the PLP gene (cDNA PLP, exon IV polymorphism) and of the Xq22 region (DXS17, DXS94, and DXS287), whereas the markers located more proximally (DXYS1X and DXS3) or distally (DXS11) were not linked to the PMD locus. Multipoint analysis gave a maximal location score for the PMD locus (13.98) and the PLP gene (8.32) in the same interval between DXS94 and DXS287, suggesting that in all families PMD is linked to the PLP locus. Mutations of the extraexonic PLP gene sequences or of another unknown close gene could be involved in PMD. In an attempt to identify molecular defects of this genomic region that are responsible for PMD, these results meant that RFLP analysis could be used to improve genetic counseling for the numerous affected families in which a PLP exon mutation could not be demonstrated.

Adolescent↗
PubMed1993

[Thoracic splanchnectomy under video-thoracoscopy].

The technique of thoracic splanchnicectomy under video thoracoscopic control is described. This little aggressive surgical operation is indicated for very painful forms of pancreatic cancer and for some cases of chronic pancreatitis. It should relieve pain for a longer period than splanchnic nerve injection or radiotherapy.

Humans↗
PubMed1993

Refined linkage map of chromosome 5 in the region of the spinal muscular atrophy gene.

The genetic map in the region of human chromosome 5 that harbors the gene for autosomal recessive forms of spinal muscular atrophy (SMA) has been refined by a multilocus linkage study in 50 SMA-segregating families. Among six markers spanning 8 cM for combined sexes, four were shown to be tightly linked to the SMA locus. Multipoint linkage analysis was used to establish the best estimate of the SMA gene location. Our data suggest that the most likely location for the SMA locus is between blocks AFM114ye7 (D5S465)/EF5.15 (D5S125) and MAP-1B/JK53 (D5S112) at a sex-combined genetic distance of 2.4 and 1.7 cM, respectively. Thus the SMA gene lies in the 4-cM region between these two blocks. This information is of primary importance for designing strategies for isolating the SMA gene.

Base Sequence↗
PubMed1993

Machado-Joseph disease is genetically different from Holguin dominant ataxia (SCA2).

Machado-Joseph disease (MJD) and Holguin ataxia (SCA2) are autosomal dominant multisystem degenerations with spinocerebellar involvement that are predominant among people of Portuguese-Azorean and of Cuban descent, respectively. Their clinical distinction may at times be difficult to make in individual patients, due to significant phenotypic overlapping (similar overall age-of-onset and duration of cerebellar ataxia, eye movement, and, often, other common problems. The recent mapping of SCA2 to chromosome 12q provided another candidate region for linkage studies of MJD. Original data on 10 families with Holguin ataxia show that the locus for phenylalanine hydroxylase (PAH) on chromosome 12q is linked to SCA2 at 4 cM and is thus far its closest marker. The exclusion of linkage 15 cM on each side of PAH in 16 families with MJD shows that these two forms of dominant ataxia are genetically distinct and at different chromosomal locations (nonallelic).

Cuba↗
PubMed1993

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy maps to chromosome 19q12.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) has been recently reported as a cause of stroke. It is characterized, in the absence of hypertension, by recurrent subcortical ischaemic strokes, starting in early or midadulthood and leading in some patients to dementia. Magnetic resonance imaging and pathological examination show numerous small subcortical infarcts and a diffuse leukoencephalopathy underlaid by a non-arteriosclerotic, non-amyloid angiopathy. We performed genetic linkage analysis in two unrelated families and assigned the disease locus to chromosome 19q12. Multilocus analysis with the location scores method established the best estimate for the location of the affected gene within a 14 centimorgan interval bracketed by D19S221 and D19S222 loci.

Adult↗
PubMed1993

Autosomal dominant familial spastic paraplegia is genetically heterogeneous and one locus maps to chromosome 14q.

Autosomal dominant familial spastic paraplegia (FSP) is a degenerative disorder of unknown aetiology characterized by a progressive spasticity of the legs. Three families with autosomal dominant FSP of early onset were analysed in linkage studies using highly polymorphic microsatellite markers. Close linkage to a group of markers on chromosome 14q (maximum multipoint lodscore z = 10) was observed in one family. This chromosome 14q candidate region was entirely excluded in the two other families, providing evidence of genetic heterogeneity within a homogeneous clinical form of FSP.

Adult↗
PubMed1993

Intraoperative coronary angioscopy--technique and results: a study of 38 patients.

Over a period of 11 months, 38 patients submitted to coronary artery revascularization underwent intraoperative angioscopy of the coronary arteries and internal thoracic arteries. Fifty-nine lesions were observed, but only 31 stenoses responsible for coronary insufficiency were observed (33%). Forty-four distal anastomoses were explored (47%) but ten of these explorations were incomplete. None revealed technical failure of the anastomosis. Thirteen harvested left internal mammary arteries were explored. One of the explorations led to rejection of the graft due to an intimal fracture. Some tiny intimal flaps were observed in our experience, as in others. Although the iatrogenic origin of these lesions in relation to the introduction of the angioscope is obvious, it does not seem to influence the outcome of the operation. In our opinion, two main fields appear to be developing in coronary angioscopy: preoperative assessment of the quality of internal thoracic artery grafts, and control of distal graft anastomoses. The flexibility of the angioscopes and of the leading catheters must be improved to minimize the risk of arterial wall traumatic lesions.

Angioscopes↗
PubMed1993

Autosomal dominant Marfan-like connective-tissue disorder with aortic dilation and skeletal anomalies not linked to the fibrillin genes.

We describe a large family with a connective-tissue disorder that exhibits some of the skeletal and cardiovascular features seen in Marfan syndrome. However, none of the 19 affected individuals displayed ocular abnormalities and therefore did not comply with recognized criteria for this disease. These patients could alternatively be diagnosed as MASS (mitral valve, aorta, skeleton, and skin) phenotype patients or represent a distinct clinical entity, i.e., a new autosomal dominant connective-tissue disorder. The fibrillin genes located on chromosomes 15 and 5 are clearly involved in the classic form of Marfan syndrome and a clinically related disorder (congenital contractural arachnodactyly), respectively. To test whether one of these genes was also implicated in this French family, we performed genetic analyses. Blood samples were obtained for 56 family members, and four polymorphic fibrillin gene markers, located on chromosomes 15 (Fib15) and 5 (Fib5), respectively, were tested. Linkage between the disease allele and the markers of these two genes was excluded with lod scores of -11.39 (for Fib15) and -13.34 (for Fib5), at theta = .001, indicating that the mutation is at a different locus. This phenotype thus represents a new connective-tissue disorder, overlapping but different from classic Marfan syndrome.

Adult↗
PubMed1992

Clinical and genetic heterogeneity of Charcot-Marie-Tooth disease.

The autosomal dominant forms of hereditary motor and sensory neuropathies include the hypertrophic form (CMT1) and the neuronal form of Charcot-Marie-Tooth disease (CMT2). While at least two distinct loci have been shown to be linked to the CMT1 phenotype (CMT1A and CMT1B, on chromosomes 17 and 1, respectively), whether the CMT2 phenotype results from mutations allelic to either of the CMT1 genes remains unknown. Studying one CMT1 and two CMT2 pedigrees, we were able to exclude the CMT2 disease locus from the region of chromosome 17 (Z = -2.80 at theta = 0.05 for D17S58) where the CMT1A gene maps (Z = +3.67 at theta = 0.00). Similarly, negative lod score values were obtained in CMT2 for the region of chromosome 1 where the CMT1B gene has been located (Z = -3.09 at theta = 0.05 for D1S61). The present study therefore provides evidence for genetic heterogeneity between the hypertrophic and the neuronal forms of Charcot-Marie-Tooth disease and demonstrates that the CMT2 gene is not allelic to either of the CMT1 genes mapped to date.

Charcot-Marie-Tooth Disease↗
PubMed1992

Prenatal prediction of Werdnig-Hoffmann disease using linked polymorphic DNA probes.

Werdnig-Hoffmann disease is a common autosomal recessive neuromuscular disorder that results in paralysis and death. No treatment to prevent this disease or to alter its unremitting course has been found. Recently, linkage analysis with cloned DNA probes has shown that the mutation causing Werdnig-Hoffmann disease is located on chromosome 5q12-q14. We performed genetic analysis for the prenatal diagnosis of Werdnig-Hoffmann disease in seven at risk families. Two fetuses were diagnosed as being affected and the remainder as unaffected, and this was confirmed after birth. This study shows that prenatal diagnosis of Werdnig-Hoffmann disease has become feasible.

Chromosomes, Human, Pair 5↗
PubMed1992

[Total anomalous pulmonary venous return in a 61 year-old adult].

The authors report a case of total anomalous pulmonary venous return successfully treated by surgery in a 61 year-old man. This case is unusual because of the late discovery of this congenital malformation which is usually rapidly fatal in the absence of surgical correction. This prolonged survival can be explained by the large atrial septal defect and the absence of obstruction, to pulmonary venous return and associated malformations. Surgical repair is essential to prevent the development of irreversible lesions of the right side of the heat and the pulmonary arterial bed.

Heart Defects, Congenital↗
PubMed1992

Proximal spinal muscular atrophy (SMA) types II and III in the same sibship are not caused by different alleles at the SMA locus on 5q.

Proximal spinal muscular atrophy (SMA) is a group of progressive muscular diseases recently mapped to chromosome 5q. SMA is usually classified into types I-III, and there are cases of two types of SMA in the same sibship. Becker and others later proposed that these sibships might be due to the existence of several alleles at the same locus predisposing to the different forms of the disease. In a sample of four sibships in which both SMA type II and SMA type III occur, this hypothesis was clearly rejected for the SMA locus on 5q, by using information on the segregation of linked markers (P less than .001). Thus the difference between SMA type II and SMA type III is not due to different alleles at the SMA locus on 5q. This finding is suggestive of an involvement of other factors, genetic or environmental, in the determination of disease severity in SMA.

Alleles↗