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Biomedical subjects

J Y Riou

Publications and source records attributed to J Y Riou.

At least 19 recordsLinked to original sources
PubMed2004

[Transradial approach for diagnostic angiography].

Seventy five arteriographies were performed via the transradial route using 5F 130cm - long catheter. Prior to puncture the radial artery was evaluated with Allen test. Satisfying quality examinations were obtained for the thoracic aorta, selective carotid arteries examinations, infra renal aorta, pelvic and legs arteries. The major advantages obtained for the technique were the very low rate complication and technical failure. Transradial route for arteriography is a reasonable alternative approach to transfemoral or brachial arteriography for out patient management (peripheral angiography) in case in which transfemoral route is not feasible but also with patients with important haemorragic-risks.

Angiography↗
PubMed2003

[Aneurysm of the persistent sciatic artery].

The authors report a case of persistent sciatic artery presenting with limb ischemia and pulsatile mass in the buttock treated only by femoro tibio peroneal by pass graft since follow up helical CTA at six months showed spontaneous aneurysmal exclusion by thrombosis of the persistent sciatic artery above the aneurysm. Review of the literature confirms the rarity of this anomaly, which is frequently associated with aneurysmal transformation and its specific inherent complications. It is treated by femoro popliteal shunt with endovascular embolization.

Aneurysm↗
PubMed2002

[Endovascular embolization of a splenic aneurysm and of a false aneurysm of the splenic artery].

Splenic artery aneurysms, once considered rare entities are now being reported with increasing frequency. Rupture may be the presenting and only symptom and can be fatal. The authors present two cases of splenic aneurysms treated by endovascular embolization. The initial imaging work-up included sonography, angiography and helical computed tomography with multiplanar and 3D reformations. This enabled comprehensive evaluation of the aneurysms, including their configuration, essential for coil selection. Embolization was uneventful. Post-embolization angiograms confirmed exclusion of the aneurysms. Follow-up CT at 9 months showed complete thrombosis of the aneurysms and no evidence of pancreatic or splenic complication. Endovascular management for definitive treatment of splenic aneurysms is technically possible and should be considered.

Aged↗
PubMed2001

Fit genotypes and escape variants of subgroup III Neisseria meningitidis during three pandemics of epidemic meningitis.

The genetic variability at six polymorphic loci was examined within a global collection of 502 isolates of subgroup III, serogroup A Neisseria meningitidis. Nine "genoclouds" were identified, consisting of genotypes that were isolated repeatedly plus 48 descendent genotypes that were isolated rarely. These genoclouds have caused three pandemic waves of disease since the mid-1960s, the most recent of which was imported from East Asia to Europe and Africa in the mid-1990s. Many of the genotypes are escape variants, resulting from positive selection that we attribute to herd immunity. Despite positive selection, most escape variants are less fit than their parents and are lost because of competition and bottlenecks during spread from country to country. Competition between fit genotypes results in dramatic changes in population composition over short time periods.

Alleles↗
PubMed2001

[Intra-arterial fibrinolytic therapy for acute mesenteric ischemia].

We report a case of mesenteric ischemia secondary to embolic occlusion treated by percutaneous intra-arterial thrombolysis. Early initial radiographic evaluation included abdominal plain film, ultrasonography, abdominal CT, and arteriography. Only selective superior mesenteric artery angiography provided definite diagnosis. The duration of ischemic symptoms before thrombolysis was 6 hours. Post procedure angiogram at 12 hours showed complete resolution of the mesenteric arterial thrombus with clinical improvement. The most important criteria for patient survival is early diagnosis and immediate treatment. Direct infusion of urokinase into the superior mesentric artery may be an alternative to surgery in selected patients and particularly in patients without evidence of frank bowel necrosis.

Acute Disease↗
PubMed2001

[Percutaneous treatment of a common iliac aneurysm extending to the hypogastric artery with embolization and a covered endoprosthesis].

A case of iliac aneurysm treated percutaneously by endovascular stent graft (Wallgraft - Boston) and transcatheter embolization of internal iliac artery in order to prevent retrograde filling of the aneurysm from the patent hypogastric artery is presented. The initial radiographic evaluation included arteriography, and 2D and 3D spiral CT angiograms. This enabled analysis of the extent of mural thrombus, flow direction, as well as selection of stent graft and coil size. The procedure of embolization and implantation was technically uneventful. Post procedure 3D CT and arteriography demonstrated exclusion of the aneurysm, and return to a normal flow pattern. Follow-up at 6 and 12 months confirmed the stability of the results. Percutaneous treatment of common iliac artery aneurysms involving the hypogastric artery can be performed easily, especially in elderly patients. 3D CT is essential in assessing the endo and extra luminal characteristics of the aneurysm to insure optimal results and to detect complications.

Aged↗
PubMed1999

[Community-acquired bacterial meningitis in the Loire-Atlantic region: evolution of pneumococcal and meningococcal sensitivity to penicillin].

OBJECTIVES: An epidemiological study of community-acquired bacterial meningitis was conducted in Loire-Atlantique in subjects aged over 1 month. Risk factors and changes in pneumococcal and meningococcal susceptibility to betalactams were analyzed. PATIENTS AND METHODS: All cases of proven or presumed bacterial meningitis registered by Loire-Atlantic bacteriology laboratories between May 1995 and April 1998 were analyzed. RESULTS: One hundred two cases were registered (annual incidence: 3.12 cases per 100,000 inhabitants). In children (33 cases) the main germs were meningococci (51%), pneumococci (24%) and Haemophilus influenzae (6%). In adults (69 cases), pneumococci (49%), meningococci (14%) and Listeria (4%) predominated. An underlying disease was noted 44% of the cases. Mortality was 17.6%. Sequellae were observed in 9.5%. Some degree of penicillin resistance was observed in 45% of the pneumococcal strains and in 50% of the meningococcal strains. Half of the pneumococcal strains were also resistant to third generation cephalosporins (C3G). No risk factor was significantly related to resistant strains. Susceptibility to antibiotics was not correlated with mortality for either pneumococcal or meningococcal strains, but sequellae were more frequent after meningitis caused by resistant pneumococci. CONCLUSION: For cases of community-acquired meningococcal meningitis diagnosed in 1999, it would be advisable to prescribe a combination C3G-vancomycin regimen as the first line empirical treatment while waiting for results of susceptibility tests. Certain guidelines proposed by the February 1996 consensus conference on community-acquired purulent meningitis would thus need to be amended.

Adult↗
PubMed1999

Pulmonary thromboendarterectomy for chronic thromboembolic obstruction of the pulmonary artery in piglets.

OBJECTIVE: The 2 main causes of death after thromboendarterectomy for chronic pulmonary thromboembolism are incomplete repermeabilization responsible for persistent pulmonary hypertension and acute high-permeability pulmonary edema. We wish to establish an experimental model of chronic pulmonary thromboembolism to replicate the conditions encountered during and after pulmonary thromboendarterectomy. METHODS: Multiple-curled coils and tissue adhesive were embolized in 6 piglets to induce complete obstruction of the left pulmonary artery, documented by angiography. After 5 weeks, the main pulmonary artery was repermeabilized by thromboendarterectomy during circulatory arrest. The left lung was reperfused ex vivo with autologous blood at constant flow, and patency of the pulmonary artery was evaluated on a barium angiogram. The endarterectomy-reperfusion procedure was also done in 6 nonembolized piglets that served as the controls. The severity of lung injury induced by 60 minutes of reperfusion was assessed on the basis of measurements of the lung filtration coefficient and of lung myeloperoxidase activity. RESULTS: Marked hypertrophy of the bronchial circulation was seen in the chronic pulmonary thromboembolism group. Thromboendarterectomy removed the organized obstructing thrombus that was incorporated into the arterial wall and restored patency of the pulmonary artery. Acute lung inflammation and high-permeability edema occurred after reperfusion, as indicated by a 1.5-fold increases in both lung filtration coefficient and lung myeloperoxidase values in the chronic pulmonary thromboembolism group; these 2 variables being correlated. CONCLUSIONS: Our model replicated the perioperative conditions of pulmonary thromboendarterectomy, suggesting that it may prove useful for improving the repermeabilization technique and for investigating the mechanisms and prevention of reperfusion injury.

Animals↗
PubMed1999

[Percutaneous treatment of a superficial femoral artery aneurysm using an intravascular stent-prosthesis].

One case of superficial femoral aneurysm treated percutaneously by endovascular stent graft (Passager Boston) is reported. The initial radiographic evaluation included arteriography and color doppler sonography which enable analysis of the flow path, the extent of the wall thrombus, the choice of stended graft size. The procedure of implantation was technically trouble free. The post-procedure 3D CT and arteriography demonstrated occlusion of the aneurysm and resaturation of normal flow path. The six and twelve month check confirmed the stability of the results locally and the integrity of run off vessels. In weakened and specially elderly patient percutaneous treatment of superficial femoral artery aneurysm can be carried out easily. The contribution of 3D CT is essential in follow up to ensure an optimal result and to detect any complication.

Aged↗
PubMed1998

High-level chloramphenicol resistance in Neisseria meningitidis.

BACKGROUND: Neisseria meningitidis is nearly always susceptible to the penicillins, the cephalosporins, and chloramphenicol. Between 1987 and 1996, however, chloramphenicol-resistant strains were isolated from 11 patients in Vietnam and 1 in France. METHODS: The minimal inhibitory concentration of chloramphenicol was determined for the 12 isolates. The isolates were analyzed by monoclonal-antibody-based serotyping and subtyping, pulsed-field gel electrophoresis, and multilocus enzyme electrophoresis. Bacterial DNA was analyzed by hybridization, the polymerase chain reaction, and sequencing to identify the resistance gene and determine the origin of the resistance. RESULTS: The isolates were resistant to chloramphenicol (minimal inhibitory concentration, > or =64 mg per liter) and produced an active chloramphenicol acetyltransferase. All 12 strains belonged to serogroup B but had a high degree of diversity, and 10 could not be typed with the use of monoclonal antibodies. The nucleotide sequence of the resistance gene and the flanking regions was identical to that of an internal portion of transposon Tn4451 that carries the catP gene in Clostridium perfringens. Moreover, this gene was located in the same genomic site in the chloramphenicol-resistant isolates. CONCLUSIONS: The high-level chloramphenicol resistance that we describe in N. meningitidis isolates is of great concern, since in developing countries, chloramphenicol given intramuscularly is the standard therapy for meningococcal meningitis. The resistance to chloramphenicol is due to the presence of the catP gene on a truncated transposon that has lost mobility because of internal deletions, and the transformation of genetic material between strains of N. meningitidis probably played an important part in the dissemination of the gene.

Base Sequence↗
PubMed1997

Endocervical infection in a pregnant woman caused by Neisseria meningitidis: evidence of associated oropharyngeal colonization of the male partner.

A case of premature birth associated with an endocervical infection caused by Neisseria meningitidis is reported. Treatment of the mother with amoxycillin eradicated the bacteria from the endocervix and avoided newborn colonization or infection. Epidemiological investigation identified meningococcal oropharyngeal colonization of the male partner. The two strains were of the same antigenic formula B:4:P1.14 and exhibited identical rDNA restriction fragment patterns and outer membrane protein profiles. This phenotypic and genomic identity of strains is the first clear evidence for cross-colonization between sexual partners.

Adult↗
PubMed1997

Genetic analysis of a meningococcal population based on polymorphism of the pilA-pilB locus: a molecular approach for meningococcal epidemiology.

The genetic relationships between 88 meningococcal strains were analyzed by using the polymorphism of the pilA gene and the multilocus enzyme electrophoresis. While a good agreement was observed, correlation with antigenic formula (serogroup, serotype, and serosubtype) was incomplete. The inadequacy of serological classification alone in outbreak surveillance may be overcome by DNA-based approaches.

Alleles↗
PubMed1997

Neisseria meningitidis: fifteen cases of bronchopulmonary infections associated with septicaemia.

From 1989 to 1995, 4,053 meningococcal strains with a clinical information form were sent to the National Reference Center for Meningococci (NRCM). Among these strains 569 meningococci (14.04%) were isolated from secretions of the bronchopulmonary tract by expectoration or fibroscopy protected or not from contamination by microflora. Fifteen observations associated an infection of bronchopulmonary syndrome and a meningococcemia without any other symptoms. These patients were in general elderly (mean = 71.3 years old) except for two cases: one of them presented sickle cell anemia and the other was very young (13 months). In all cases, there were signs of clinical and X-ray pneumopathies. Among the fifteen cases described, eight cases occurred during the winter, and four during the spring. Twelve were described in countries north of the Loire. Serogroup Y was isolated six times, serogroup B four times and serogroup C three times. The small quantity of cases did not permit us to study the distribution of serotype and serosubtype. Three patients, aged 92, 86 and 74 years old, died from the meningococcal infection.

Adult↗
PubMed1997

Epidemiological survey of Neisseria meningitidis susceptibility to penicillin G in France.

The susceptibility of 82 strains of Neisseria meningitidis to penicillin G and amoxicillin was evaluated with two media "gonococci-meningococci" medium (G medium) derived from Mueller Hinton and chocolate agar. Among these 82 strains 52 were isolated from CSF and/or blood and 30 from miscellaneous isolates. G medium was compared with chocolate agar using the correlation between diameters and MIC and the E-test. Routinely standardised antibiogram is still used but the authors added the following techniques 1) MIC of penicillin G is tested (0.06; 0.125; 0.250; 0.50 mg/l); 2) use of oxacillin disc charged with 5 micrograms. Penicillinase producing meningococci were not found. Standardised antibiogram on 4192 strains resulted in a modal distribution of diameters between 18 to 40 mm. Moderate meningococci susceptible strains to penicillin G are increasing in France: 1994: 4%; 1995: 11%; 1996: 18%.

Amoxicillin↗
PubMed1996

Epidemics of serogroup A Neisseria meningitidis of subgroup III in Africa, 1989-94.

A total of 125 strains of Neisseria meningitidis recovered in the course of outbreaks from patients with systemic disease in 11 African countries between 1989 and 1994 were analysed by serogrouping, serotyping and multilocus enzyme electrophoresis. Of the 125 patient strains 115 (92%) belonged to the clone-complex of serogroup A meningococci, designated subgroup III. Among the remaining strains, 4 were also serogroup A, but belonged to the clonal groups I and IV-1 (2 strains each), whilst 6 strains (4 serogroup C and 2 serogroup W135) represented clones of the ET-37 complex. Our results indicated that the second pandemic caused by clones of subgroup III is still spreading in Africa. Towards the West it has reached Niger, Mali, Guinea and The Gambia, and towards the South, the Central African Republic, Uganda, Rwanda, Burundi, Tanzania and Zambia.

Africa↗
PubMed1996

A predictable comeback: the second pandemic of infections caused by Neisseria meningitidis serogroup A subgroup III in Africa, 1995.

Between 14 January and 4 April 1995 we isolated and characterized 44 meningococcal strains in Cameroon, Chad, Niger, and Burkina Faso; among these was the strain A:4:P1.9/clone III-1, which was involved in the second meningitis pandemic. This isolate was found in the clonal form in Niger and strains of the ET-37 complex were also found in the other three study countries, but apparently did not cause epidemics. One strain (Y:2a:P1.2,5 (ET-37 complex)) was isolated in January 1995 and another (A:4:P1.9) in March 1995 in Garoua (Cameroon). Eight strains were isolated in Moundou (Chad) between January and April 1995: the A:4:P1.9/clone III-1 (1 strain); members of the ET-37 complex (Y:2a:P1.2,5 (4 strains), Y:NT:P1.2,5 (1 strain), and Y:2a:-(1 strain)); and serogroup X (1 strain). In Niger, 31 strains were isolated between February and April 1995 from different regions. All were A:4:P1.9/clone III-1; between November 1994 and April 1995 there were 23814 cases of meningitis reported of which 2227 resulted in death. Three strains were isolated in Burkina Faso in April 1995: two were Y:2a:P1.2,5 (ET-37 complex) and one was A:4:P1.9/clone III-1. Thus in 1995 the epidemic and invasive strain (A:4:P1.9/clone III-1) responsible for the second pandemic was present in the four countries (Cameroon, Chad, Niger and Burkino Faso) that make up the area frequently affected by such epidemics and where cases are generally reported during the dry season.

Adolescent↗