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Biomedical subjects

J Amiel

Publications and source records attributed to J Amiel.

At least 91 records · Page 5Linked to original sources

[La Peyronie disease. Historical, epidemiological, physiopathological data. Diagnostic and therapeutic approaches].

The origin of Peyronie's disease remains obscure although the first description dates back to 1743. The prevalence of the disease is 388.6 per 100,000 population. Little physiopathologic data is available. Repeated microtrauma to the tunica albuginea appears to favor the onset of inflammatory phenomena, in turn the source of fibrosis. Clinical examination remains the ideal method for diagnosis and follow-up: it can be completed by ultrasonography of the corpora cavernosa. Magnetic resonance imaging does not appear to provide any significant benefits. The inflammation and pain encountered in early stages of the disease can be managed medically. Numerous treatments have been tested (oral route or local injections); results are in the course of evaluation. In the absence of well-controlled clinical trials, there is no standard medical therapy. Radiotherapy today appears inadvisable. The sequels of Peyronie's disease can be treated surgically, especially in patients who can maintain and adequate erection but suffer from a deformation incompatible with sexual activity. Numerous technical artifices have been proposed; correction of deformations is generally satisfactory but perfections need to be made concerning the quality of erection. Patients with advanced disease and severe erectile insufficiency can be offered reconstructive surgery using penile implants: results of the various procedures are analyzed.

Humans↗

Features of DiGeorge syndrome and CHARGE association in five patients.

We report on five patients presenting with features of two congenital disorders, DiGeorge syndrome (DGS) and CHARGE association. CHARGE association is usually sporadic and its origin is as yet unknown. Conversely, more than 90% of DGS patients are monosomic for the 22q11.2 chromosomal region. In each of the five patients, both cytogenetic and molecular analysis for the 22q11.2 region were normal. In view of the broad clinical spectrum and the likely genetic heterogeneity of both disorders, these cases are consistent with the extended phenotype of either DGS without 22q11.2 deletion or CHARGE association, especially as several features of CHARGE association have been reported in rare patients with 22q11.2 deletion association phenotypes. On the other hand, these could be novel cases of an independent association involving a complex defect of neural crest cells originating from the pharyngeal pouches.

Abnormalities, Multiple↗

Survival motor neuron gene deletion in the arthrogryposis multiplex congenita-spinal muscular atrophy association.

The survival motor neuron (SMN) gene was lacking in 6/12 patients with arthrogryposis multiplex congenita (AMC) associated with spinal muscular atrophy (SMA). Neither point mutation in the SMN gene nor evidence for linkage to chromosome 5q13 were found in the other patients. Hitherto, arthrogryposis was regarded as an exclusion criterion in SMA. Our data strongly suggest that AMC of neurogenic origin is genetically heterogeneous, with a subgroup being allelic to SMA. Absence or interruption of the SMN gene in the AMC-SMA association will make the diagnosis easier and genetic counselling will now become feasible.

Arthrogryposis↗

Gangrene of the perineum.

Fournier's gangrene, an anaerobic necrotizing cellulitis of the infradiaphragmatic soft tissues, is a serious pathologic entity with an unpredictable course. From 1978 to 1991, a total of 24 men (mean age, 57 years; range 27 to 90) were treated for this entity at our institution. Diagnosis prompted immediate institution of multimodal treatment combining triple antibiotics, surgical dissection, debridement, and repeated surgical drainage. Fecal diversion (16 patients), hyperbaric oxygenation, and standard intensive care procedures were widely indicated and performed quasi-systematically. The mean interval between initial symptoms and diagnosis was 7.4 days. Lesions were limited to the perineum in 11 patients but extended to the abdomen, thighs, or loins in the remaining 13. The pathogens were identified in 19 patients, and hemoculture results were positive in 5. A coloproctologic origin was identified in 12 patients and a urogenital origin in 4. In 2 patients, perineal gangrene occurred postoperatively, and no etiology was determined for 6. Six patients died, and 18 patients recovered, without any sequelae. The prognosis is better when the patient is young (less than 60 years old), has clinically localized disease, without systemic involvement, and sterile hemocultures and is managed with colostomy. A thorough workup is mandatory to determine the etiology (locoregional lesion, malignancy, hemopathy, arteritis).

Adult↗

Mutation of the endothelin-3 gene in the Waardenburg-Hirschsprung disease (Shah-Waardenburg syndrome).

Hirschsprung disease (HSCR) and Waardenburg sundrome (WS) are congenital malformations regarded as neurocristopathies since both disorders involve neural crest-derived cells. The WS-HSCR association (Shah-Waardenburg syndrome) is a rare autosomal recessive condition that occasionally has been ascribed to mutations of the endothelin-receptor B (EDNRB) gene. WS-HSCR mimicks the megacolon and white coat-spotting observed in Ednrb mouse mutants. Since mouse mutants for the EDNRB ligand, endothelin-3 (EDN3), displayed a similar phenotype, the EDN3 gene was regarded as an alternative candidate gene in WS-HSCR. Here, we report a homozygous substitution/deletion mutation of the EDN3 gene in a WS-HSCR patient. EDN3 thus becomes the third known gene (after RET and EDNRB) predisposing to HSCR, supporting the view that the endothelin-signaling pathways play a major role in the development of neural crests.

Amino Acid Sequence↗

Germline mutations of the RET ligand GDNF are not sufficient to cause Hirschsprung disease.

Hirschsprung disease (HSCR, aganglionic megacolon) is a common congenital malformation leading to bowel obstruction, with an incidence of 1/5,000 live births. It is characterized by the absence of intrinsic ganglion cells in the myenteric and submucosal plexuses along variable lengths of the gastrointestinal tract. As enteric neurons are derived from the vagal neural crest, HSCR is regarded as a neurocristopathy. On the basis of a skewed sex-ratio (M/F = 4/1) and a risk to relatives much higher than the incidence in the general population, HSCR has long been regarded as a sex-modified multifactorial disorder. Accordingly, segregation analysis suggested an incompletely penetrant dominant inheritance in HSCR families with aganglionosis extending beyond the sigmoid colon. We and others have mapped a dominant gene for HSCR to chromosome 10q11.2 and have ascribed the disease to mutations in the RET proto-oncogene. However, the lack of genotype-phenotype correlation, the low penetrance and the sex-dependent effect of RET mutations supported the existence of one or more modifier gene(s) in familial HSCR. In addition, thus far, RET mutations only accounted for 50% and 15-20% of familial and sporadic HSCR patients, respectively. RET encodes a tyrosine kinase receptor whose ligand was unknown. Recently, the Glial cell line-derived neurotrophic factor (GDNF) has been identified to be a ligand for RET. Moreover, Gdnf-/- knockout mutant mice display congenital intestinal aganglionosis and renal agenesis, a phenotype very similar to the Ret-/- mouse. These data prompted us to hypothesize that mutations of the gene encoding GDNF could either cause or modulate the HSCR phenotype in some cases.

Drosophila Proteins↗

Heterozygous endothelin receptor B (EDNRB) mutations in isolated Hirschsprung disease.

Hirschsprung disease (HSCR, aganglionic megacolon) is a frequent congenital malformation regarded as a multigenic neurocristopathy. Two susceptibility genes have been recently identified in HSCR, namely the RET proto-oncogene and the endothelin B receptor (EDNRB) gene. Hitherto however, homozygosity for EDNRB mutations accounted for the HSCR-Waardenburg syndrome (WS) association. Here, we report heterozygous EDNRB missense mutations (G57S, R319W and P383L) in isolated HSCR. These data might suggest that EDNRB mutations could be dosage sensitive: heterozygosity would predispose to isolated HSCR with incomplete penetrance, while homozygosity would result in more complex neurocristopathies associating HSCR and WS features. In addition, the present data give further support to the role of the endothelin-signalling pathway in the development of neural crest-derived enteric neurons.

Female↗

C618R mutation in exon 10 of the RET proto-oncogene in a kindred with multiple endocrine neoplasia type 2A and Hirschsprung's disease.

The cosegregation of multiple endocrine neoplasia (MEN) type 2A with Hirschsprung's disease (HSCR), two diseases associated with mutation of the RET proto-oncogene, is infrequent. A 30-yr-old man was referred for screening of MEN 2A. Surgery for HSCR was performed at 4 yr of age. Basal and pentagastrin-stimulated calcitonin levels were abnormal. Histological examination of the thyroid confirmed bilateral medullary thyroid carcinoma. Screening of family members revealed six subjects with medullary thyroid carcinoma or abnormal pentagastrin-stimulated calcitonin test; one had an unilateral pheochromocytoma and two were affected with HSCR. DNA sequence analysis showed a heterozygote C618R mutation in exon 10 of the RET proto-oncogene in the proband and his mother, as well as in second-degree relatives with MEN 2A phenotype or HSCR. In this study, we report on a novel kindred with MEN 2A and HSCR phenotype associated with a point mutation (C618R) in one of the cysteine codons at the extracellular domain of the RET proto-oncogene.

Adult↗

A new vaginal procedure for cystocele repair and treatment of stress urinary incontinence.

PURPOSE: Treatment of cystoceles and stress urinary incontinence continues to evolve. We evaluated the efficacy of a new vaginal wall sling procedure for cystocele repair and treatment of stress urinary incontinence. MATERIALS AND METHODS: We present our experience with the vaginal wall sling procedure in 36 patients (mean age 67.4 years) with cystocele. Of the patients 16 had undergone a prior pelvic operation. With our technique a vaginal wall tube was created with the base in the bladder neck and fixation to the periurethral tissues or suspension to the suprapubic area. RESULTS: Success rates were 95 and 82% for cystocele and stress incontinence repair, respectively. Mean followup was 17 months. Morbidity was minimal and mean hospitalization was less than 5 days. CONCLUSIONS: This original, simple, noninvasive treatment is applicable for all cystoceles regardless of patient age or sexual activity, and has shown encouraging results. Based on our experience we recommend this procedure for repair of cystoceles and stress urinary incontinence.

Adolescent↗

[CAL 54, a new cell line derived from a human renal carcinoma: characterization and radiosensitivity].

A new cell line (CAL 54) was isolated from a malignant pleural effusion of a patient with renal carcinoma. CAL 54 is a continuous and stable cell line. Immunochemical staining showed simultaneous expression of cytokeratin, epithelial membrane antigen and vimentin. Cytometric flow analysis of DNA content reveals one major hyperdiploid population. Histological aspect of the tumor induced in the nude mouse showed well differentiated adenocarcinoma with papillary structure. Radiation response of these cells was evaluated by the colony-forming method and the data were fitted with the linear-quadratic model. Survival at 2 Gy (SF2) was 0.28 and the mean inactivation dose (D) = 1.50 Gy, ranking this cell line among the radiation sensitive cells. CAL 54 may be an informative cell line to investigate radiation effects in the management of renal tumours.

Aged↗

[Genetics of Hirschsprung disease].

Hirschsprung's disease (HD) is one of the commonest gastrointestinal malformations, as it affects one child out of 5,000 births. It classically induces severe neonatal intestinal obstruction requiring surgical treatment which currently ensures a favourable prognosis for most of the affected children. Although the great majority of cases are sporadic, the existence of familial forms (10% of cases) has allowed localization and then identification of an autosomal dominant gene on chromosome 10, the RET proto-oncogene, responsible for 50% of familial forms and 15% of sporadic cases. A second gene has been recently localized on chromosome 13, the endothelium beta receptor (EDNRB) gene. Two homozygous mutations of the EDNRB gene have been identified in two consanguineous families, in which HD is associated with Waardenburg's syndrome (WS). Other heterozygous mutations have been identified in patients presenting with isolated HD and an 5% of cases of HD can be considered to present mutations of this gene. Finally, the authors have recently identified a mutation of the endothelium gene 3 (EDN3), one of the EDNRB ligands in a patient presenting with a combination of HD and WS. This mutation, present at the homozygous state in this patient, is predictive of complete absence of EDN3 protein: this is therefore the third known gene responsible for HD.

Drosophila Proteins↗

[Genetics of Hirschsprung disease].

Hirschsprung disease (HD) is one of the commonest gastro-intestinal malformations, as it affects one child out of 5,000 births. It classically induces severe neonatal intestinal obstruction requiring surgical treatment which currently ensures a favourable prognosis for most of the affected children. Although the great majority of cases are sporadic, the existence of familial forms (10% of cases) has allowed the localization and then the identification of an autosomal dominant gene on chromosome 10, the RET proto-oncogene, responsible for 50% of familial forms and 15% of sporadic cases. A second gene has been recently localized on chromosome 13, the endothelin beta receptor (EDNRB) gene. Two homozygous mutations have been identified in two consanguineous families, in which HD is associated with Waardenburg syndrome (WS). Other heterozygous mutations have been identified in patients presenting with isolated HD and 5% of cases can be considered to present mutations of this gene. Finally the authors have recently identified a mutation of the endothelin 3 gene (EDN3), one of EDNRB ligands in a patient presenting a combination of HD and WS. This mutation, present at the homozygous state in this patient, is predictive of complete absence of EDN3 protein: this is therefore the third known gene responsible for HD.

Endothelin-3↗

Familial isolated vitamin E deficiency. Extensive study of a large family with a 5-year therapeutic follow-up.

A major neurological deterioration, beginning with ataxia, led to the diagnosis of familial vitamin E deficiency in a girl. Based upon vitamin E determinations, 4/8 members of the (consanguineous) sibship were considered to be homozygous. Homozygosity was also found for the alleles of six markers linked to the AVED locus, recently identified in similar Tunisian or Sicilian families on chromosome 8q. Measures of vitamin E in lipoprotein fractions and in liver biopsy after vitamin E oral load suggested that free diffusion of vitamin E between the different compartments was possible and even increased. However, a high-affinity ligand seemed to be lacking, either in the hepatic recycling of vitamin E or in both the hepatic and the other vitamin E compartments. The 5-year substitutive treatment was successful only in the pre- or paucisymptomatic patients. Serum vitamin E must be measured in any unexplained progressive ataxia.

Adolescent↗

Diversity of RET proto-oncogene mutations in familial and sporadic Hirschsprung disease.

Hirschsprung disease (HSCR) is a common congenital malformation (1 in 5,000 live births) due to the absence of autonomic ganglia in the terminal hindgut, and resulting in intestinal obstruction in neonates. Recently, a dominant gene for familial HSCR has been mapped to chromosome sub-band 10q11.2 and the disease has been ascribed to mutations in a tyrosine kinase receptor gene mapping to this region, the RET proto-oncogene. Studying the 20 exons of the RET gene by a combination of denaturating gradient gel electrophoresis and single strand conformation polymorphism in a large series of HSCR patients (45 sporadic cases and 35 familial forms), we found mutations of the RET gene in 50% of familial HSCR, regardless of the length of the aganglionic segment. The mean penetrance of the mutant allele in familial HSCR was significantly higher in males (72%) than in females (51%). Most interestingly, mutations at the RET locus accounted for at least 1/3 of sporadic HSCR in our series. These mutations were scattered along the length of the gene. Finally, among the mutations identified in sporadic cases (16/45), seven proved to be de novo mutations suggesting that new mutations at the RET locus significantly contribute to sporadic HSCR. Taken together, the low penetrance of the mutant gene, the lack of genotype-phenotype correlation, the sex-dependent effect of RET mutations and the variable clinical expression of the disease support the existence of one or more modifier genes in familial HSCR.

Base Sequence↗

[Predictive value of urinary cytology in the diagnosis of urothelial tumors].

Between November 1991 and June 1993, 315 patients with urethral lesions were divided into two groups: group 1 included 215 patients with urethral tumours and group 2 included 100 patients with non-tumoural lesions. In all patients, urethral smears (performed on 3 consecutive days), pyelography and uretrocystoscopy (with bladder biopsy of observable lesions) were performed in all. The sensitivity of urine cytology examinations in the diagnosis of bladder cancer was found to by 80% with a specificity of 90%. The positive predictive value was 94.5% and the negative predictive value 67.7%. Urine cytology agreed with the diagnosis of urethral tumours especially well in advanced stage ulcerated tumours. These results underline the importance of cytology examinations in the exploration and follow-up of patients with urethral tumours.

Adult↗

[Surgical treatment of gangrene of the perineum].

Acute perineal gangrene due to anaerobic Gram negative bacilli or streptococci rapidly leads to tissue necrosis and death in 50% of the cases despite progress in intensive care. Emergency treatment requires adapted antibiotics, hyperbaric oxygen therapy and repeated surgery. Factors of poor prognosis include age over 60 years, lomboabdominal or crural extension, septic shock, positive blood cultures and lack of fecal derivation. Surgery is performed under general anaesthesia since loco-regional anaesthesia is contraindicated during the septic phase. Repeated operations are needed to make large incisions, evacuate pus, search for foreign bodies and resect damaged tissue in order to expose all the infected areas to air and hyperbaric oxygen. A colostomy must be performed in order to avoid fistulization and contamination of the infected areas. An indwelling urine catheter is usually sufficient although a suprapubic catheter may be needed at the risk of further extension of the gangrene. Surgical treatment is associated with intensive care and hyperbaric oxygen therapy. Three effective antibiotics are recommended. Using this aggressive surgical protocol, we have been able to reduce mortality to 20% in patients under 60 years of age.

Combined Modality Therapy↗