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Biomedical subjects

J Etienne

Publications and source records attributed to J Etienne.

At least 127 records · Page 7Linked to original sources

Toxin involvement in staphylococcal scalded skin syndrome.

The production of staphylococcal exfoliative toxin A (ETA) and toxin B (ETB), toxic shock syndrome toxin (TSST-1), and enterotoxins A-E was analyzed in 60 Staphylococcus aureus strains isolated from children with scalded skin syndrome (15 with generalized exfoliative syndrome, 28 with bullous impetigo, and 17 with staphylococcal scarlet fever). All strains isolated from patients with generalized exfoliative syndrome or bullous impetigo produced ETA and/or ETB and caused a Nikolsky's sign when injected subcutaneously into newborn mice. In contrast, exfoliative toxin was detected in an S. aureus strain from only one of 17 case of staphylococcal scarlet fever; the 16 other S. aureus strains produced TSST-1 and/or an enterotoxin. In conclusion, enterotoxins or TSST-1 are more frequently associated with staphylococcal scarlet fever than are exfoliative toxins. Hence staphylococcal scarlet fever may well represent an abortive form of toxic shock syndrome rather than a milder form of staphylococcal scalded skin syndrome.

Animals↗

Adult polycystic liver disease: is fenestration the most adequate operation for long-term management?

OBJECTIVE: The aim of this study was to evaluate the immediate and long-term results in a retrospective series of patients with highly symptomatic adult polycystic liver disease (APLD) treated by extensive fenestration techniques. A classification of APLD was developed as a stratification scheme to help surgeons conceptualize which operation to offer to patients with APLD. SUMMARY BACKGROUND DATA: Treatment options for APLD remain controversial, with partisans of fenestration techniques or combined liver resection-fenestration. METHODS: Clinical symptoms, performance status, liver volume measurement by computed tomography (CT), and morbidity were recorded before surgery and after surgery. Adult polycystic liver disease was classified according to the number, size, and location of liver cysts and the amount of remaining liver parenchyma. Follow-up was obtained by clinical and CT examinations in all patients. RESULTS: Ten patients with highly symptomatic APLD were operated on using an extensive fenestration technique (by laparotomy in 8 patients and by laparoscopy in 2 patients, 1 of whom conversion to laparotomy was required). The mean preoperative liver volume was 7761 cm3. There was no mortality. Postoperative morbidity occurred in 50%, mainly from biliary complications, requiring reintervention in two cases. Massive intraoperative hemorrhage occurred in one patient. During a mean follow-up time of 71 months (range, 17 to 239 months), all patients were improved clinically according to their estimated performance status. The mean postoperative liver volume was 4596 cm3, which represents a mean liver volume reduction rate of 43%. However, in type III APLD, despite absence of clinical symptoms, a significant increase in liver volume was observed in 40% of the patients. CONCLUSIONS: Extensive fenestration is effective in relieving symptoms in patients with APLD. Hemorrhage and biliary complications are possible consequences of such an aggressive attempt to reduce liver volume. The procedure can be performed laparoscopically in type I APLD. A longer follow-up period is mandatory in type II APLD, to confirm the usefulness of the fenestration procedure. In type III APLD, significant disease progression was observed in 40% of the patients during long-term follow-up. Fenestration may not be the most appropriate operation for long-term management of all types of APLD.

Adult↗

Synergistic hemolytic activity of Staphylococcus lugdunensis is mediated by three peptides encoded by a non-agr genetic locus.

Some strains of the coagulase-negative Staphylococcus lugdunensis produce a synergistic hemolytic activity (SLUSH), phenotypically similar to the delta-hemolysin of S. aureus. Reverse-phase high-pressure liquid chromatography of supernatants from S. lugdunensis 307 yielded three late-eluting peaks of 3.5 kDa with synergistic hemolytic activity. A degenerate oligonucleotide probe was designed from partial amino acid sequences of the 23-amino-acid (aa) tryptic fragments from one of the three peaks and hybridized to a single 2.8-kb HindIII chromosomal fragment. The relevant portion of this fragment was cloned by PCR, and sequencing showed the presence of three related open reading frames (ORFs), SLUSH-A, SLUSH-B, and SLUSH-C, preceded by an unrelated short potentially coding sequence (ORF-X), cotranscribed on a polycistronic 838-nucleotide mRNA. The amino acid sequences of the peptides from the three peaks align perfectly with the predicted sequences from the three SLUSH ORFs (peak I = SLUSH-B; peak II = SLUSH-C; peak III = SLUSH-A). These three peptides are closely related (amino acid homology, >76%) and do not show significant homology to S. aureus delta-hemolysin but do resemble a Salmonella typhimurium invasin and the "gonococcal growth inhibitor," a bacteriocin secreted by Staphylococcus haemolyticus. The predicted ORF-X gene product is a 24-aa peptide with no homology to the SLUSH peptides.

Amino Acid Sequence↗

Rapid and accurate identification of Staphylococcus species by tRNA intergenic spacer length polymorphism analysis.

PCR-amplified tRNA gene (tDNA) intergenic spacer length polymorphism (tDNA-ILP) was analyzed for its ability to identify to the species level type strains (n = 18) and clinical isolates (n = 163) of staphylococci. Amplified products obtained by PCR with outwardly directed consensus tDNA primers were separated by agarose and polyacrylamide gel electrophoreses. The results were compared with those obtained by biochemical identification and ribotyping. Each type strain presented a specific tDNA-ILP pattern. PCR with fluorescent primers allowed for the detection of labelled DNA fragments on polyacrylamide gels by using an automated laser fluorescence sequencer and provided enhanced pattern resolution in comparison with that by analysis on agarose gels. tDNA patterns indistinguishable from those of the type strains were produced by clinical isolates of all tested species except for some isolates of S. aureus (n = 3) and S. haemolyticus (n = 1), which showed variant patterns. Strains of S. saprophyticus and S. xylosus showed very closely related profiles, and S. cohnii subspecies were indistinguishable. The identities obtained by tDNA-ILP analysis agreed with those obtained by the biochemical method to the species level for 99% (162 of 163) of the strains tested and to the subspecies level for 96% (156 of 163) of the strains tested. These results indicate that fluorescence-labelled PCR analysis of tDNA-ILP provides an accurate and rapid molecular method for the identification of human staphylococci.

Bacterial Typing Techniques↗

Comparative performances of six agglutination kits assessed by using typical and atypical strains of Staphylococcus aureus.

Six commercial agglutination tests designed for the identification of Staphylococcus aureus were compared by using a strain collection which included 512 staphylococci representing 33 species (318 isolates of Staphylococcus aureus [including 144 oxacillin resistant], 46 S. epidermidis isolates, 15 S. haemolyticus isolates, 12 S. saprophyticus isolates, 29 S. schleiferi isolates, 30 S. lugdunensis isolates, and 62 other coagulase-negative staphylococci). This group also included a proportion of strains with unusual phenotypes (e.g., 19 coagulase-negative S. aureus isolates, 26 clumping factor-negative S. aureus isolates, and 4 S. aureus isolates each with a double deficiency). The overall sensitivity for identification of typical and atypical S. aureus was high with the Staphaurex Plus test (Murex Biotech) (99.7%), the Pastorex Staph Plus test (Sanofi Diagnostics Pasteur) (99.7%), and the Slidex Staph Plus test (bioMérieux) (100%). The overall rate of specificity was affected by the unusual inclusion in this study of a high proportion of non-S. aureus species, such as S. lugdunensis and S. schleiferi, which express a clumping factor and therefore produce a positive result with the agglutination tests.

Agglutination Tests↗

The first clinical isolate of Legionella parisiensis, from a liver transplant patient with pneumonia.

A bluish white autofluorescent strain of Legionella was isolated from the tracheal aspirate of a female liver transplant patient who developed hospital-acquired pneumonia. This strain had biochemical characteristics compatible with those of L. cherrii, L. anisa, and L. parisiensis and could not be differentiated from L. bozemanii and L. parisiensis by the direct fluorescent-antibody assay. Phylogenetic analysis of partial 16S rRNA gene sequences of this strain (ATCC 700174) revealed the closest homology to the species L. parisiensis (99.5%). An L. parisiensis species-specific profile was also identified by a random amplified polymorphic DNA technique. This is the first report of L. parisiensis isolation from humans.

Adult↗

Serological cross-reactions between Bartonella and Chlamydia species: implications for diagnosis.

Diagnosis of Chlamydia or Bartonella infections continues to rely mainly on serology. However, serological cross-reactions between members of these genera have recently been described. Sera from eight patients originally diagnosed as having Chlamydia pneumoniae endocarditis reacted with both Chlamydia sp. and Bartonella quintana antigens (microimmunofluorescence technique). Adsorption of sera with B. quintana or C. pneumoniae antigens removed anti-C. pneumoniae antibodies, whereas adsorption with C. pneumoniae antigens did not change antibody titers to B. quintana. Western blot analysis confirmed the presence of cross-reacting antigens and showed antibody patterns in all sera to be compatible with a Bartonella infection. These patients were therefore probably suffering from Bartonella-induced rather than Chlamydia-induced endocarditis. In contrast, sera from 10 patients presumed to be suffering from C. pneumoniae pneumonia did not display anti-B. quintana antibodies, although cross-reacting antigens were revealed by Western blotting. This work highlights the possibility that cases of infective Bartonella endocarditis are erroneously diagnosed as chlamydial infections.

Adsorption↗

Diagnosis of 22 new cases of Bartonella endocarditis.

BACKGROUND: Bartonella species are emerging pathogens that are seldom reported as a cause of blood culture-negative endocarditis. OBJECTIVE: To report the occurrence of, risk factors for, and clinical features of Bartonella endocarditis and to evaluate the diagnostic tools available for this condition. DESIGN: Case series and comparison with past series. SETTING: Multicenter international study in Halifax, Nova Scotia, Canada; Lyon, France; and Marseille, France. PATIENTS: 22 patients from France, England, Canada, and South Africa were investigated for blood culture-negative endocarditis. MEASUREMENTS: Titer of antibodies to Bartonella species by microimmunofluorescence assay, blood or vegetation culture, and amplification of Bartonella DNA from valvular tissue by polymerase chain reaction. Cross-adsorption was done for patients with antibodies to Chlamydia species. RESULTS: 22 patients had definite endocarditis. Five were infected with B. quintana, 4 with B. henselae, and 13 with an undetermined Bartonella species. These cases were compared with the 11 previously reported cases. Of the patients with the newly reported cases, 19 had valvular surgery and 6 died. Nine were homeless, 11 were alcoholic, 4 owned cats, and 13 had preexisting valvular heart disease. Bartonella species caused 3% of the cases of endocarditis seen in the three study centers. The patients with these cases could have previously received a diagnosis of chlamydial endocarditis because of apparently high levels of cross-reacting antibodies to Chlamydia species. CONCLUSIONS: Bartonella species are an important cause of blood culture-negative endocarditis and can be identified by culture, serologic studies, or molecular biology techniques. Alcoholism and homelessness without previous valvular heart disease are risk factors for B. quintana infection but not for infection with other Bartonella species.

Adult↗

Comparison of infective endocarditis in patients with and without previously recognized heart disease.

In a consecutive series of patients with infective endocarditis, we compared the charts of 123 nonaddicted patients without previously known heart disease with those of 174 patients with native valve disease. The 2 groups were similar in age, sex, clinical findings, and mortality rates, but infective endocarditis was more often located on the aortic valve, more often due to Streptococcus bovis and enterococci in patients without previously known heart disease.

Aged↗

New serotype of Bartonella henselae in endocarditis and cat-scratch disease.

BACKGROUND: The fastidious nature of Bartonella henselae is such that demonstration of clinical infection relies mainly on serological or molecular biological methods. Only five isolates have been obtained from patients with cat-scratch disease (CSD) and none from endocarditis. METHODS: We isolated B henselae from a CSD patient and, for the first time, from a patient with endocarditis. The isolates were characterised on the basis of morphology, biochemistry, cell-wall fatty-acid analysis, PCR-restriction fragment length polymorphism analysis of the 16-23S intragenic spacer region, and 16S rRNA gene sequences. Characterisation of these isolates indicated them to belong to a new serogroup, which we have called "Marseille", and to a new genotype based on the 16S rRNA gene sequence. The new variant was incorporated into an immuno-fluorescence antibody test (IFAT), which was used to reassess serum samples from 113 CSD patients who were seronegative with the conventional IFAT. FINDINGS: 18 (16%) of these apparently seronegative patients yielded significantly raised titres. 20 CSD patients who were seropositive as judged by the conventional IFAT remained seropositive with the new IFAT. INTERPRETATION: Antigenic variability within the species is one possible reason for inconsistent results in the serological diagnosis of CSD.

Adult↗

Nucleic acid sequence and affiliation of pLUG10, a novel cadmium resistance plasmid from Staphylococcus lugdunensis.

Tolerance of Staphylococcus lugdunensis to relatively high levels of cadmium is mediated by a 3117-bp plasmid, pLUG10. Sequencing reveals three major open reading frames (ORFs) in a single orientation. One ORF encompasses the origin of replication and its predicted product (RepL: 350 amino acids (aa)) shows 70% homology in its deduced aa sequence with Rep proteins of the pT181 family. A lagging strand conversion signal (palA) very similar to that of class 1 plasmids is present outside the rep-ori locus. The other two ORFs of 209 and 116 aa show 92.5% homology between their deduced aa sequences and the CadB and CadX peptides from the pOX6 plasmid of Staphylococcus aureus. The CadX-like peptide is 40% homologous to the S. aureus CadC product. Deletion of the C-terminal cadX gene by restriction enzyme digestion or frame-shift inactivation of the cadB gene reduced, but did not completely abolish, cadmium resistance. The two gene products may act cooperatively to confer cadmium resistance in S. lugdunensis.

Amino Acid Sequence↗

Human lipoprotein lipase last exon is not translated, in contrast to lower vertebrates.

We have sequenced the first fish (zebrafish, Brachydanio rerio) lipoprotein lipase (LPL) cDNA clone. Similarities were found in mammalian LPL cDNA, but the codon spanning the last two exons (which is thus split by the last intron) is AGA (Arg) as opposed to TGA in mammals. Exon 10 is thus partially translated. These results were confirmed with rainbow trout (Oncorhynchus mykiss). We also investigated whether mammal TGA coded for selenocystein (SeCys), the 21st amino acid, but found that this was not the case: TGA does not encode SeCys but is a stop codon. It thus appears that the sense codon AGA (fish) has been transformed into a stop codon TGA (human) during the course of evolution. It remains to be determined if the "loss" of the C-terminal end of mammalian LPL protein has conferred an advantage in terms of LPL activity or, on the contrary, a disadvantage (e.g., susceptibility to diabetes or atherosclerosis).

Animals↗

Laparoscopic splenectomy in adults and children: experience with 31 patients.

BACKGROUND: Open surgery is the standard approach for splenectomy in hematologic disorders, but a few cases of successful laparoscopic splenectomy have been reported. METHODS: Thirty-one patients (18 adults, group 1; and 13 children, group 2) underwent laparoscopic splenectomy. Indications for surgery included idiopathic thrombocytopenic purpura (25 patients), congenital spherocytosis (4 patients), and hemolytic anemia (2 patients). In 97% of the patients the diameter of the spleen was less than 15 cm. RESULTS: Laparoscopic splenectomy was successful in 94% of the patients; conversion to open surgery was mainly related to hemorrhage. Accessory spleen was found in 39% in group 1 and 8% in group 2. Two adults received intraoperative autotransfusion. Postoperative morbidity was minimal. The median postoperative stay was 3 days (range, 2 to 12 days) in group 1 and 2 days (range, 2 to 5 days) in group 2. CONCLUSIONS: Laparoscopic splenectomy is safe in both adults and children. Adequate selection of patients (small-size spleen, splenic destruction on preoperative scanning of platelets), appropriate preparation in patients with idiopathic thrombocytopenic purpura (immunoglobulin G), and meticulous surgical technique (with routine opening of the gastrocolic ligament to search for accessory spleen) are key factors in obtaining the same long-term results as with open surgery.

Adolescent↗

Assessment of wall velocity gradient imaging using a test phantom.

A new phantom has been designed to gain a better understanding of tissue Doppler imaging (TDI). Specifically, the phantom can easily be used to determine myocardial velocity gradients. The phantom mimics the left ventricle and is made of fine-grade sponge material whose ultrasound image closely resembles the gray scale image obtained from heart walls. Theoretical analysis of phantom wall movements offers a plausible explanation for the velocity gradients developing across the heart walls. The results of computer analysis were found to be in very good agreement with TDI M-mode recordings of phantom wall displacement.

Computer Simulation↗

Distribution of mip-related sequences in 39 species (48 serogroups) of Legionellaceae.

The macrophage infectivity potentiator gene (mip) from Legionella pneumophila is a major virulence factor of the species. Thus, mip-detection by amplification has been proposed to assess the presence of L. pneumophila in clinical and environmental samples. The distribution of mip-related sequences within the Legionellaceae was studied by DNA amplification using mip-specific primers followed by Southern blot hybridization with an internal probe. Thirty-nine species (48 serogroups) of Legionellaceae were screened in this attempt. Using this approach, sequences related to mip were observed in 89% of the tested species including the most recently described L. fairfieldensis, L. lansingensis and L. shakespearei. In several cases, cloning and sequencing of the amplified products confirmed the high levels of similarity between the sequence found in non-pneumophila species with that of the L. pneumophila mip gene. This confirms previous reports that mip related genes are widespread among Legionellaceae and therefore specific detection of the species L. pneumophila cannot be based on mip-targeted amplification.

Blotting, Southern↗

Elective Laparoscopic Splenectomy: Person Experience and Literature Review.

Laparoscopic splenectomy has become an attractive treatment for patients with selected hematologic disorders. Almost 200 observations have been reported. The rate of conversion to laparotomy is 10% to 15%, and the complication rate is between 0% and 30%. Adequate selection of patients, preoperative administration of intravenous immunoglobulin in patients with idiopathic thrombocytopenic purpura, meticulous surgical techniques, and careful preoperative and intraoperative search for accessory spleen are critical factors for success in these patients. The procedure should be confined to expert laparoscopic surgeons with considerable experience in the management of hematologic diseases.

Journal Article↗

Coagulase-negative staphylococci isolated from two cases of toxic shock syndrome lack superantigenic activity, but induce cytokine production.

Two strains of Staphylococcus epidermidis isolated from patients with toxic shock symptoms have been reported to carry genes related to S. aureus enterotoxins B and C by dot-blot hybridisation, although the corresponding superantigenic toxins were not detected immunologically. We here show that these strains produce no superantigens capable of stimulating proliferation of human mononuclear leukocytes or rabbit splenocytes, and that no DNA homologous to the seb or sec genes can be detected by PCR. However, stimulation of human monocytes by whole killed bacteria induced dose-dependent production of the cytokines TNF alpha, IL-1 beta and IL-6, which may be responsible for the clinical symptoms in these patients.

Antigens, Bacterial↗