Search PubMed⌕ Search

Biomedical subjects

V Vidal

Publications and source records attributed to V Vidal.

At least 55 records · Page 3Linked to original sources
PubMed1996

Endovascular repair of iliac artery aneurysm with Endoprosystem I: a multicentric French study.

Due to their position deep in the pelvis, the classical surgical treatment of iliac artery aneurysm leads to a high morbidity and mortality rate. The transfemoral percutaneous repair of these aneurysms is now possible thanks to a new device the endoprosystem I from "Mintech". We began in 1994 a study including radiological, cardiac and vascular centers all of them skilled in endovascular procedures. 27 patients entered the study: 1 patient died, 2 attempt failed and 2 presented leakage: the immediate failure rate was then 18.5%. For the late result (min 6, Max 19, mean 12 months) we had 1 thrombosis treated by surgery, 1 restenosis treated by PTA. We did not see any polyester dilatation or reactivation of aneurysm at the scan control at one year. We conclude that the percutaneous treatment of iliac aneurysm is possible and safe but we need long term result to validate the method.

Blood Vessel Prosthesis↗
PubMed1996

[Hereditary predispositions to cancer: the genetic diagnosis in practice].

Genetic consultations allow to identify families in which an hereditary predisposition to cancer is transmitted. In most cases the gene involved can be studied leading to identification of families members carrying or not the mutation conferring the cancer risk. In this case, cancer risk is more accurately explained and measures, adjusted to the risk, were proposed for early screening of the disease. Capacities to characterize an inherited mutation of the susceptibility gene vary according to our knowledge of the gene, its structure, its function, the kind of mutation(s) and also, the available techniques. The purpose of this paper is to describe the most frequently used techniques for direct or indirect molecular diagnosis of cancer predisposition and to specify, for each of them, the situations where its use seem the fittest. The example of breast cancer hereditary predisposition, where multiple susceptibility genes were identified and other are still unknown, illustrates the various degree of diagnosis that can be proposed and the strategy techniques used according to the gene.

Breast Neoplasms↗
PubMed1995

Transluminal recanalization of occluded iliac arteries: a surgical experience.

The purpose of this study was to evaluate the feasibility of transluminal techniques in an unselected group of patients and to assess long-term outcome in successful procedures. All patients in whom iliac artery recanalization was attempted were included in this study. Patients with an occluded prosthesis or recent embolism were excluded. A total of 37 patients were studied. Assessment of the success or failure of the procedure was based on the results of control arteriography. Recanalization was deemed successful in 31 patients. This study demonstrates that transluminal recanalization of occluded iliac arteries by a surgeon is indeed feasible. Primary patency was 66% at 24 months. The potential risk, however, is long-term restenosis. Thus follow-up examination every 6 months is recommended including pressure index measurements after exercise and color Doppler ultrasonography of the recanalized zone.

Adult↗
PubMed1995

[A new method of studying gastric emptying in gastrectomized patients].

OBJECTIVE: We present a new method of assessment of gastric emptying in gastrectomized patients. PATIENTS AND METHODS: The gastric emptying of non digestible solids were studied in two groups of gastrectomized patients, the Billroth II (n = 25) and the Roux-en-Y (n = 36) to relate the gastric emptying with the postgastrectomy symptoms. RESULTS: The food retained in the gastric stump is related with significance with the presence (p = 0.01) and the absence (p = 0.02) of markers. The patients operated on with the Billroth II technique present a higher frequency of markers in the gastric stump (40% over 19.4% with the Roux-en-Y). The markers in the gastric stump are more common with the symptoms of pyrosis, nausea, bilious vomit, diarrhea and the postoperative gastritis of alkaline reflux. CONCLUSIONS: The method of gastric emptying of non digestible solids is a valid and reliable study of the gastric emptying and should be carried out in all candidates for endoscopy because it is harmless and easy to perform and evaluate.

Adult↗
PubMed1995

Interaction of BiP with substance P and nucleotides.

A rapid and simple spin column assay has been used to study interactions of BiP with substance P (SP) and ATP. At 4 degrees C, the binding of SP to BiP requires ATP and a stable SP-BiP.ATP complex is formed. Nonhydrolyzable ATP analogues or ADP cannot replace ATP. Although ATP converts BiP dimers to monomers, the requirement for ATP for SP binding is not solely due to BiP dissociation, because purified BiP monomers also require ATP for peptide binding. At 37 degrees C, there is rapid binding of SP to BiP even in the absence of ATP and, in fact, ATP at concentrations above 5 microM causes release of SP from BiP. At this higher temperature, there is also rapid hydrolysis of ATP bound to BiP. These results extend our previous results (Brot et al., 1994) that indicated the formation, at low ATP concentrations, of a labile SP.BiP.ATP complex that, after ATP hydrolysis, resulted in a stable SP.BiP.ADP complex.

Adenosine Triphosphate↗
PubMed1994

Similarity of nucleotide interactions of BiP and GTP-binding proteins.

BiP is a member of the Hsp70 heat shock protein family found in the lumen of the endoplasmic reticulum, that binds to a variety of proteins destined to be secreted. Substance P (SP) has been used as a model peptide to study the interaction of BiP with protein substrates. SP stimulates BiP ATPase activity and forms a stable complex with BiP that is dissociated in the presence of levels of ATP > 50 microM. At lower concentrations of ATP, the SP remains bound to BiP, and the results are consistent with the view that a BiP-ATP complex is initially formed that reacts with SP to form a ternary complex, SP-BiP-ATP. Hydrolysis of ATP in this complex yields a SP-BiP-ADP complex. An exchange of ATP with ADP bound to BiP has also been demonstrated, and the results suggest that the interactions of BiP with ATP resemble those seen with GTP-binding proteins and GTP.

Adenosine Diphosphate↗
PubMed1994

BiP is a substrate for src kinase in vitro.

In a study to investigate the ability of chaperones to modulate src kinase activity, it was observed that BiP, a member of the HSP70 family found in the endoplasmic reticulum, is an excellent substrate for src kinase in vitro. The reaction requires polylysine and the results suggest that two tyrosine residues are phosphorylated. Although there is no evidence for this reaction in vivo, it does provide a very efficient method to label BiP.

Carrier Proteins↗
PubMed1993

Dissociation of glucose-regulated protein Grp78 and Grp78-IgE Fc complexes by ATP.

Recent studies have shown that ATP can dissociate dimers of the glucose-regulated protein Grp78 to monomers. In the present study, we have used purified recombinant Grp78 from Escherichia coli to investigate this reaction in more detail. During the course of the Grp78 dimer-monomer conversion, a stable Grp78 monomer-ATP complex is formed. Upon removal of the ATP, the Grp78 dimer is reformed. ADP, nonhydrolyzable ATP analogues, and GTP do not effect the dissociation of Grp78 dimers. A cell line that overproduces IgE Fc has been used to examine the nature of the Grp78-IgE Fc complexes present and the effect of ATP on them. Grp78-IgE Fc complexes ranging from 100 kDa to 300 kDa were observed by sucrose gradient analysis, suggesting that aggregate forms of Grp78 may be present in some of these complexes. Treatment of the extracts with ATP resulted in release of a Grp78 monomer from the complex. These results suggest that the dissociation of Grp78 oligomers by ATP may be involved in the function of Grp78 in protein translocation through the endoplasmic reticulum.

Adenosine Triphosphate↗
PubMed1993

Molecular characterization of a 70 kDa heat-shock protein of bean mitochondria.

A bean cDNA clone that specifies a 70 kDa heat-shock protein (hsp70) has been isolated and sequenced. The nucleotide sequence analysis shows that the cDNA could encode a 72 kDa protein that is highly related to prokaryotic and mitochondrial members of the hsp70 family. The predicted protein was found to contain an amino-terminal extension typical of transit sequences. The in vitro transcription/translation product of the cDNA behaved as a 72 kDa polypeptide as predicted from the longest open reading frame. This polypeptide could be imported into isolated mitochondria and recovered as a 68 kDa product. The imported protein is identical in size to a mitochondrial protein that cross-reacts with hsp70-specific antibodies. The import data and Western blot analysis suggest that the cDNA clone encodes a mitochondrial member of the hsp70 family. Electrophoretic and immunoblot analysis reveal that the protein is loosely associated to the mitochondrial envelope and also exists as discrete soluble protein aggregates of about 270 and 420 kDa. Hsp70 of bean mitochondria can be in vitro phosphorylated on threonine residues in a calcium-dependent manner, and the modified protein was detected as an oligomer of about 160 kDa only. The data are discussed with respect to the chaperone function of hsp70 in mitochondria.

Amino Acid Sequence↗
PubMed1993

[Long-term results of Carpentier-Edwards and Saint-Jude Medical mitral valve prosthesis].

Between 1980 and 1985, 239 patients underwent mitral valve replacement with a Saint Jude Medical (130) or Carpentier-Edwards (109) prosthesis alone or associated with correction of tricuspid regurgitation. Age, NYHA grade and pulmonary artery pressures were comparable in the two groups. Two hundred and seventeen of the 221 survivors were contacted (98.6% follow-up): the long-term prosthesis-related mortality was 35% in the Saint Jude Medical group and 22.5% in the Carpentier-Edwards group. The global survival at 9 years was 82% in the Saint Jude Medical group but only 63% in the Carpentier-Edwards group. The actuarial thromboembolic-free rate at 9 years was 96% in the Saint Jude Medical and 86% in the Carpentier-Edwards group (not significant). Two Saint Jude Medical and one Carpentier-Edwards bioprosthesis thrombosed--a linear rate of 0.2% PY and 0.1% PY respectively. Furthermore, there was no significant difference in the actuarial rate of haemorrhagic complications between the two groups. Endocarditis and valve degeneration were more common in the Carpentier-Edwards group (1.3% and 1.6% PY respectively). Over the 9 year period, the thromboembolic complications of the Saint Jude Medical and Carpentier-Edwards prostheses were similar in actuarial and linear terms. With respect to long-term mortality and morbidity, the results with the Saint Jude Medical valve seem to be superior to those of the Carpentier-Edwards bioprosthesis.

Actuarial Analysis↗
PubMed1993

[20 years of mitral valve replacement. Development of a patient profile and operative mortality].

Between 1971 and 1991, 1,179 mitral valve replacements (MVR) were carried out in 1,134 patients. The sex ratio was stable over this period (0.7 men/women) whereas the average age of the patients increased by 10 years (50 years in 1971, 61 years in 1991). Since 1980, patients over 60 years of age represent about 60% and those over 70 years of age 16 to 22% of the population. The functional status of the patients has tended to be less severe, the NYHA stages III and IV which were initially preponderant, only represent 50 to 60% of patients operated nowadays. This reduction in the severity of symptoms is reflected in the average value of the cardio thoracic index which was 60 in 1971 and 54.8 in 1991. Similarly, the mean pulmonary artery pressures (measured in 823 patients, 69.8%) have decreased from 37.4 mmHg in 1971 to 29.9 mmHg in 1991. Rheumatic fever has tended to be replaced by degenerative etiologies which, since 1985, represent 40 to 50% of cases. Ischemic mitral regurgitation rare before 1980, is more common, presently making up 5 to 15% of MVR cases. In relation with the etiological changes mitral stenosis is giving way to mitral regurgitation as the commonest valve lesion (40 to 50% of cases in 1991). The annual operative mortality is lower (6 to 8%) than in 1982, despite the increasing number of emergency cases (7 to 10% of cases since 1985). The number of MVR with associated tricuspid valve repair has decreased with respect to isolated MVR or associated with aortocoronary bypass grafting. The only constant feature is the death rate due to myocardial dysfunction which remains over 50% whereas mortality related to the prosthetic valves varied over the years.

Age Factors↗
PubMed1992

[Immediate and long-term results of 790 mitral valve replacements].

A total of 790 patients underwent isolated (N = 520) or mitral valve replacement associated with a tricuspid valve procedure for lesions excluding post-myocardial infarction mitral regurgitation. The mean age was 54 years: the sex ratio was 1.9 +/- 1.1, female/male. Three hundred and four patients (38.5%) were in the NYHA functional class II and 406 patients (61.5%) were in classes III or IV. The operative mortality was 9.7% (77 patients). The factors associated with a high operative risk were, on multifactorial analysis: double valve replacement, age over 70 years, NYHA class IV, aortic clamp time over 68 minutes and the presence of mitral regurgitation. Seven hundred and four of the 713 survivors were contacted (98.7% follow-up). The average follow-up period was 5.05 years (range 11 to 219 months) giving a total of 3,997 patient-years. The 5 and 10 year actuarial survival rates were 74.7% and 64.7% respectively. The presence of a tricuspid lesion requiring surgical correction, a high NYHA classification and the presence of mitral regurgitation were poor prognostic factors of long-term survival. Three hundred and sixteen of the 533 survivors at the time of the inquiry were in NYHA class I (59.3%), 188 in NYHA class II (35.3%) and 29 in NYHA class III or IV (5.4%). Mitral valve replacement should be considered early as the immediate and long-term results are closely related to the preoperative myocardial function.

Actuarial Analysis↗
PubMed1991

[Mitral valve replacement in postinfarction mitral insufficiency. Immediate and long-term results apropos of a series of 39 surgically-treated patients].

Thirty nine patients, mainly males (84.6%) with an average age of 66 years underwent mitral valve replacement for postinfarction mitral regurtation between March 1971 and December 1987. Twenty four were in Class IV of the NYHA Classification, 9 in Class III and 6 in Class II. All had a history of myocardial infarction predominantly of the inferior wall. The 33 preoperative coronary angiogrammes showed 13 patients with triple vessel disease, 15 with double vessel disease and 5 with single vessel disease. At operation, 13 patients had ruptured papillary muscles; acute dysfunction was observed in 16 and chronic in 10 patients. The hospital mortality was 36%; over three quarters of deaths were due to myocardial dysfunction. Twenty two patients had an associated myocardial revascularisation procedure with mitral valve replacement. All 25 survivors were followed up for an average of 2.3 years (94 patient-years). The 5 year actuarial survival (operative mortality included) was 55% and 77% of the 17 survivors are in Stages I or II of the NYHA Classification. The quality of these long-term results justifies surgery despite the high operative risk.

Actuarial Analysis↗
PubMed1991

[A comparative evaluation of a prosthetic operation and balloon valvuloplasty in aortic valve stenosis in elderly people].

The results of surgical treatment of aortic stenosis (AS) in elderly patients were studied in a group of 602 patients aged from 70 to 90 years (average age 74.6 years) chosen from a total number of 1,643 persons who underwent operation for AS in 1975-1988. Total operative mortality with consideration for mortality connected with combined interventions was 11.4%, in the group of isolated prosthetics it was 10.4%. The late-term results were appraised in 96.6% of patients (in 3.6 years, on the average). According to actuarial charts, survival after 3 years was 75.9%, after 5 years--66.7%, and after 7 years--55.6%. There was no difference in the survival values of recipients of biological and mechanical prostheses. Significant improvement of the functional condition was noted (96.5% of patients belonged to NYHA classes I and II). Demographic and epidemiological studies showed this pathology in the elderly to be a new problem of surgery. Surgical treatment is justified by the quality of the results, prolonged survival, and an admissible risk level even at the age of 80-90 years. Comparison with the results of aortic balloon valvuloplasty studied on basis of a rich literature review shows these to be much poorer. On the whole, only surgery may be the real method of treatment allowing effective removal of AS. The operation can be carried out even on very old patients if there are no substantiated contraindications on the part of the brain and the patient's general condition.

Actuarial Analysis↗
PubMed1990

[Duplication of the urethra in a young girl. Apropos of a case].

Duplication of the female urethra is quite uncommon. A case of complete urethral duplication is reported in a 2.5 year old girl seen for pyuria. Physical examination showed and epispadiac meatus with dribbling urine just above a bifid clitoris associated with an orthotopic meatus. The two urethras were patent and situated on the same sagittal plane as seen on the cystography. The treatment consisted of excising the whole epispadic urethra using a combined perineal and suprapubic approach enlarged by symphyseal section for a better repair of the bladder outlet. Postoperatively, the patient was content and free of symptom. The main features of urethral duplication in girl are reviewed.

Child, Preschool↗