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Biomedical subjects

A Ben Ali

Publications and source records attributed to A Ben Ali.

At least 19 recordsLinked to original sources

[Detection of nasal colonization methicillin-resistant Staphylococcus aureus: a prospective study comparing real-time genic amplification assay vs selective chromogenic media].

UNLABELLED: In contrast to "classical" genic amplification, real-time genic amplification can be performed in every laboratory without the need of sophisticated isolation procedures. Moreover, real-time genic amplification allows an early detection of meticillin resistant Staphylococcus aureus colonization, 2 hours compared to 1 or 2 days for culture. OBJECTIVE: In order to assess the feasibility on Smartcycler of the IDI-MRSA real-time genic amplification assay in comparison with chromogenic media. METHODS: A prospective study has been initiated in July 2004: nasal swabs were taken from patients entering the ICU, vascular surgery, diabetology and geriatry wards. During a 4 months period, 682 specimens have been obtained from 508 patients. RESULTS: Sixty-four (9.3%) patients were positive by genic amplification and selective agar culture (CHROMagar MRSA, MRSASelect and/or ORSAB), 19 (2.9%) were positive by genic amplification only (3 of these patients were under antibiotic treatment); 572 specimens remained negative by both methods. The sensitivity and specificity of this assay were 100% and 96% respectively with a positive predictive value of 70% and negative predictive value of 100%. Initially 82 nasal specimens were unresolved (12%). 38 were resolved following a freeze-thaw cycle. Thus, 44 (6.4%) were unresolved specimens. Comparison between CHROMagar MRSA and MRSASelect showed a good correlation for the detection at 24 hours (5.5% and 5.6% respectively). These two chromogenic media allowed a much better detection of MRSA than ORSAB medium within 24H. CONCLUSION: The results obtained by the early real-time genic amplification for the detection of meticillin resistant Staphylococcus aureus are promising. Despite 6.4% amplification failure, we consider that IDI-MRSA real-time genic amplification assay represents a significant breakthrough in the detection of colonization.

Culture Media↗

[Hydatid cyst of the liver].

Hydatid cyst of the liver is a parasitic disease caused by Echinococcus granulosus. The principal complications are infection, biliary duct fistula, and rupture into the peritoneum or chest. Diagnosis has become easier with advances in ultrasonic imaging and CT scanning. Surgery remains the most effective treatment but postoperative complications arise in 30% of cases, particularly when the surgical approach is conservative. Radical surgical approaches give better results and should be used in most cases. Biliocutaneous fistula and infection of the residual cavity are the most common postoperative complications and result in prolonged hospitalization and excess costs. New therapeutic strategies incorporate endoscopic, percutaneous, and medical therapies with surgery and have allowed an improvement in morbidity and mortality due to hydatid cysts of the liver. Until immunization becomes a possibility, preventive measures are necessary to avoid disease recurrence.

Echinococcosis, Hepatic↗

False synergy between vancomycin and beta-lactams against glycopeptide-intermediate Staphylococcus aureus (GISA) caused by inappropriate testing methods.

The combination of vancomycin and beta-lactams is often considered synergistic and has been recommended for the treatment of glycopeptide-intermediate Staphylococcus aureus (GISA) infections. In this study, the combination of vancomycin or teicoplanin with different beta-lactams was tested. When using NaCl 4% w/v, for better expression of heterogeneous resistance to beta-lactams, with a longer (48-h) incubation period and a higher (10(7) CFU/mL) inoculum, the association of vancomycin with beta-lactams was antagonistic. However, a synergistic effect was observed for teicoplanin under the same conditions.

Anti-Bacterial Agents↗

[Treatment of severe botulism with 3,4-diaminopyridine]].

INTRODUCTION: The specific treatments of botulism with serotherapy and with guanidine are of debatable efficacy. We report a case of nutritional toxin B botulism successfully treated with 3,4-diaminopyridine. OBSERVATION: Following a meal, a 69 year-old woman consulted for digestive disorders followed by damage to several cranial pairs, autonomous nervous system and ventilation command, motivating mechanical ventilation on tracheal intubation. Administration of symptomatic treatment with 3,4-diaminopyridine led to progressive improvement, although the diagnosis of toxin B botulism was confirmed. COMMENTS: Administration of 3,4-diaminopyridine, the efficacy of which had been suggested by the review of experimental literature, led to rapid and clear improvement, probably due to its potentiating effect on acetylcholine release in the neuromuscular junction.

4-Aminopyridine↗

[The Munchausen syndrome: a diagnosis not to be forgotten in urology].

INTRODUCTION: Among the manifestations of Münchausen's syndrome, "neurological" forms may exist. OBSERVATION: We present the case of a patient presenting with urinary retention following treatment for urinary incontinence. The patient had injected himself with infected urine collected from his catheter, in order to create septicemia. COMMENTS: Nephritic colitis, false gall stones, addition of fecal matter or of food and saliva in the urine or the bladder, neurogenic bladder and urinary infections have all been reported as possible manifestations of Münchausen's syndrome. Diagnosis of this syndrome is often delayed and laborious, after repeated hospitalisations, examinations and often aggressive treatment. Its therapeutic management is difficult. Patients, despite proof, deny their deceit and refuse psychiatric care.

Diagnosis, Differential↗

[Anal metastasis of colonic adenocarcinoma?].

Two cases of sigmoid and anal adenocarcinoma are reported. The two patients were treated by abdominoperineal resection of the rectum and resection of the sigmoid colon. The relationship between colonic adenocarcinoma and anal adenocarcinoma is not obvious but possible. The various mechanisms of tumoral spread are discussed and the most frequent mechanism seems to be cellular exfoliation.

Adenocarcinoma↗

Colonization with methicillin-resistant Staphylococcus aureus in ICU patients: morbidity, mortality, and glycopeptide use.

OBJECTIVE: To determine the impact of methicillin-resistant Staphylococcus aureus (MRSA) colonization on the occurrence of S. aureus infections (methicillin-resistant and methicillin-susceptible), the use of glycopeptides, and outcome among intensive care unit (CU) patients. DESIGN: Prospective observational cohort survey. SETTING: A medical-surgical ICU with 10 single-bed rooms in a 460-bed, tertiary-care, university-affiliated hospital. PATIENTS: A total of 1,044 ICU patients were followed for the detection of MRSA colonization from July 1, 1995, to July, 1 1998. METHODS: MRSA colonization was detected using nasal samples in all patients plus wound samples in surgical patients within 48 hours of admission or within the first 48 hours of ICU stay and weekly thereafter. MRSA infections were defined using Centers for Disease Control and Prevention standard definitions, except for ventilator-associated pneumonia and catheter-related infections, which were defined by quantitative distal culture samples. RESULTS: One thousand forty-four patients (70% medical patients) were included in the analysis. Mean age was 61+/-18 years; mean Simplified Acute Physiologic Score (SAPS) II was 36.4+/-20; and median ICU stay was 4 (range, 1-193) days. Two hundred thirty-one patients (22%) died in the ICU. Fifty-four patients (5.1%) were colonized with MRSA on admission, and 52 (4.9%) of 1,044 acquired MRSA colonization in the ICU. Thirty-five patients developed a total of 42 S. aureus infections (32 MRSA, 10 methicillin-susceptible). After factors associated with the development of an S. aureus infection were adjusted for in a multivariate Cox model (SAPS II >36: hazard ratio [HR], 1.64; P=.09; male gender: HR, 2.2; P=.05), MRSA colonization increased the risk of S. aureus infection (HR, 3.84; P=.0003). MRSA colonization did not influence ICU mortality (HR, 1.01; P=.94). Glycopeptides were used in 11.4% of the patients (119/1,044) for a median duration of 5 days. For patients with no colonization, MRSA colonization on admission, and ICU-acquired MRSA colonization, respectively, glycopeptide use per 1,000 hospital days was 37.7, 235.2, and 118.3 days. MRSA colonization per se increased by 3.3-fold the use of glycopeptides in MRSA-colonized patients, even when an MRSA infection was not demonstrated, compared to non-colonized patients. CONCLUSIONS: In our unit, MRSA colonization greatly increased the risk of S. aureus infection and of glycopeptide use in colonized and non-colonized patients, without influencing ICU mortality. MRSA colonization influenced glycopeptide use even if an MRSA infection was not demonstrated; thus, an MRSA control program is warranted to decrease vancomycin use and to limit glycopeptide resistance in gram-positive cocci.

Adult↗

Phylogenetic relationships among algae based on complete large-subunit rRNA sequences.

The complete or nearly complete large-subunit rRNA (LSU rRNA) sequences were determined for representatives of several algal groups such as the chlorarachniophytes, cryptomonads, haptophytes, bacillariophytes, dictyochophytes and pelagophytes. Our aim was to study the phylogenetic position and relationships of the different groups of algae, and in particular to study the relationships among the different classes of heterokont algae. In LSU rRNA phylogenies, the chlorarachniophytes, cryptomonads and haptophytes seem to form independent evolutionary lineages, for which a specific relationship with any of the other eukaryotic taxa cannot be demonstrated. This is in accordance with phylogenies inferred on the basis of the small-subunit rRNA (SSU rRNA). Regarding the heterokont algae, which form a well-supported monophyletic lineage on the basis of LSU rRNA, resolution between the different classes could be improved by combining the SSU and LSU rRNA data. Based on a concatenated alignment of both molecules, the phaeophytes and the xanthophytes are sister taxa, as well as the pelagophytes and the dictyochophytes, and the chrysophytes and the eustigmatophytes. All these sister group relationships are highly supported by bootstrap analysis and by different methods of tree construction.

Base Sequence↗

Microsporidia: accumulating molecular evidence that a group of amitochondriate and suspectedly primitive eukaryotes are just curious fungi.

Microsporidia are obligate intracellular parasites that have long been considered to be primitive eukaryotes, both on the basis of morphological features and on the basis of molecular, mainly ribosomal RNA-based, phylogenies. However, accumulating sequence data and the use of more sophisticated tree construction methods now seem to suggest that microsporidia share a common origin with fungi and are therefore most probably just curious fungi. In this paper, we describe the current views on the phylogenetic position of the microsporidia and present additional evidence for a close relationship between fungi and microsporidia on the basis of reanalyzed ribosomal RNA data. In this respect, the importance of incorporating detailed knowledge of the substitution pattern of sequences into phylogenetic methods is discussed.

Animals↗

[Tuberculous mesenteric lymphadenitis: a case report].

The authors report a case of mesenteric tuberculous lymphadenitis which mimic a pancreatic cystadenoma. They emphasize ultrasound and CT scan features which lead to the recognition of tuberculosis and permit a percutaneous fine needle biopsy. Laparotomy seems the most reliable method for a positive diagnosis. The place of different imaging methods is discussed.

Adult↗

[Neutropenia with fever].

CAUSAL GERMS: Over the last 10 years, hemotology units have seen many changes in the epidemiological pattern of infections in neutropenic patients, with a growing number of infections caused by Gram-positive germs. The number of septicemias due to multiresistant Gram-negative germs (Pseudomonas aeruginosa, Strenotrophomonas maltophilia) has however remained high. IMPACT OF THERAPEUTIC REGIMENS: Improved prognosis in neutropenic patients depends for a large part on careful management of septic episodes. As the risk of septicemia is strongly correlated with the degree of efficacy of antibiotic regimens, susceptibility data must always be examined when developing antibiotic protocols in units caring for neutropenic patients.

Anti-Bacterial Agents↗

Construction of a variability map for eukaryotic large subunit ribosomal RNA.

In this paper, we present a variability map of the eukaryotic large subunit ribosomal RNA, showing the distribution of variable and conserved sites in this molecule. The variability of each site in this map is indicated by means of a colored dot. Construction of the variability map was based on the substitution rate calibration (SRC) method, in which the substitution rate of each nucleotide site is computed by looking at the frequency with which sequence pairs differ at that site as a function of their evolutionary distance. Variability maps constructed by this method provide a much more accurate and objective description of site-to-site variability than visual inspection of sequence alignments.

Animals↗

[Postero-lateral surgical approach to soft cervical herniated discs. Technical note].

Most ruptured cervical discs are operated on by an anterolateral approach. The posterior approach is an older procedure, nowadays underused because it was associated with a high morbidity, especially in terms of medullary complications. However, posterior approach has evolved in posterolateral route, which is not so devastating and has a very low morbidity rate. It gives excellent functional results when surgery is dedicated to monoradiculopathy from soft posterolateral cervical hernias. It seems appropriate to consider this surgical route as an alternative to anterolateral surgery in these very selected cases. The authors describe and comment the technique.

Cervical Vertebrae↗

[Hydatic cysts of the liver ruptured into the thorax. Diagnostic and therapeutic aspects].

Hydatic cysts of the liver can rupture into the thorax. The aim of this work was to demonstrate how abdominal access can be used in most cases. We report 44 cases of hydatic cysts which ruptured into the thorax among a series of 1411 hydatic cysts of the liver operated between 1974 and 1995. Abdominal ultrasound and chest x-ray provided the diagnosis preoperatively in 35/42 operated cases (one case of spontaneous elimination of a hydatic membrane via a cutaneous orifice and one case of preoperative death). Thoracophrenolaparotomy was used in 12 cases, thoracotomy with laparotomy in 6, thoracotomy alone in 5 and laparotomy alone in 19. Pulmonary resections were performed in 18 cases. No procedure could be performed in one patient who died at the beginning of surgery. A breach in the diaphragm was repaired in 41 cases. The dome of the cyst was resected in 29 cases and complete pericystectomy was performed in 12. There were 7 post-operative deaths. There were no deaths in the abdominal access patients. All emergency problems were controlled with abdominal access. Thoracic access was reserved for specific cases.

Adolescent↗

[Rhino-orbito-cerebral zygomycosis (mucormycosis) in diabetes insipidus].

A case of rhino-orbito-cerebral zygomycosis in a diabetic patient treated with insulin is reported. Diagnosis was suspected because of extensive necrotic lesions of the face and was confirmed by mycologic tests. During hospital stay the patient developed a diabetes insipidus and the outcome was lethal because of the extension of lesions in spite of convenient antimycotic therapy.

Adult↗