Nosocomial respiratory infection due to an imipenem-resistant Pseudomonas aeruginosa O: 12 strain in a Tunis's neonatal intensive care unit

OBJECTIVE: Investigation of an outbreak caused by an imipenem-resistant Pseudomonas aeruginosa strain and research of its hospital reservoir. PATIENTS AND METHODS: Nine strains isolated from protected tracheal specimens during 14 weeks (October 2004 to January 2005) from 8 infants, and one strain from vacuum interrupter were studied. Epidemiological study was investigated by determination of antibiotics susceptibility, serotyping and Pulsed-field gel electrophoresis (PFGE). RESULTS: Strains were of O:12 serotype, they have the same antibiotype characterised by imipenem resistance. Strains were indistinguishable or closely related as determined by PFGE. The common source of P. aeruginosa O:12 strains was not determined, however eradication of the epidemic strain was obtained by amelioration of hygiene conditions and the change of disinfectors. CONCLUSION: Outbreak of respiratory infections due to an imipenem-resistant P. aeruginosa O:12. The common source of the epidemic strain was not determined.     

Differential effects of bexarotene on intrinsic and extrinsic pathways in TRAIL-induced apoptosis in two myeloid leukemia cell lines

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induces programmed cell death (apoptosis) preferentially in tumor cells. However, not all cancer cells are sensitive to TRAIL. We determined whether ligation of the retinoid receptor, RXR, would sensitize cells to TRAIL-mediated apoptosis. The leukemic cell lines KG1a (apoptosis-resistant) and ML-1 (apoptosis-sensitive) were treated with the RXR-specific retinoid bexarotene, TRAIL, or both, and apoptosis was determined. In KG1a cells, bexarotene downregulated FLIP(Long) and activated caspase-8, thereby allowing for TRAIL-triggered apoptosis. Overexpression of FLIP(Long) in ML-1 cells abrogated apoptosis. In unmodified ML-1 cells bexarotene enhanced programmed cell death via truncation of Bid and release of cytochrome C. Blockade of caspase-8 prevented enhancement in both cell lines; blockade of caspase-9 had a significant effect only in ML-1 cells. Thus, the effect of bexarotene on TRAIL-mediated programmed cell death involved proximal events of the extrinsic pathway; however, downstream signals involved the intrinsic pathway in ML-1 but not in KG1a cells. These studies add further information to the regulation of programmed cell death in leukemic cells that have to be considered when designing therapeutic strategies.     

Phenotypic and genotypic characterization of Salmonella enterica recovered from poultry meat in Tunisia and identification of new genetic traits

Thirty-seven Salmonella enterica isolates obtained from poultry meat in Tunisia were included in this study for characterization of antibiotic resistance mechanisms. High percentages of resistance were detected to ampicillin, sulfonamides, tetracycline, nalidixic acid, and streptomycin (32.4%-89.2%), and lower percentages to amoxicillin-clavulanic acid, kanamycin, amikacin, trimethoprim-sulfamethoxazol, and chloramphenicol (2.7%-18.9%). All strains showed susceptibility to ceftazidime, cefotaxime, gentamicin, and ciprofloxacin. Class 1 integrons were detected in 30% of Salmonella isolates, and four different gene cassette arrangements were detected, including genes implicated in resistance to aminoglycosides (aadA1 and aadA2) and trimethoprim (dfrA1). Four different Pc variants (PcW, PcH1, PcH1(TTN-10), PcW(TGN-10)) with inactive P2 have been found among these isolates. Integron-positive isolates were ascribed to eight different serotypes. A Salmonella Schwarzengrund isolate harbored a new class 1 integron containing the qacH-dfrA1b-aadA1b-catB2 gene cassette arrangement, with the very unusual PcH1(TTN-10) promoter, which has been registered in GenBank (accession no. HQ874651). Different plasmid replicon types were demonstrated among integron-positive isolates: IncI1 (8 isolates), IncN (8), IncP (2), IncFIB (2), and IncFII (2). Ten different pulsed-field gel electrophoresis profiles were detected among the 11 integron-positive isolates and 8 different sequence types were identified by multilocus sequence typing, one of them (registered as ST867) was new, detected in 3 Salmonella Zanzibar isolates. A high diversity of clones is observed among poultry Salmonella isolates and a high proportion of them show a multiresistant phenotype with very diverse mobile genetic structures that could be implicated in bacterial dissemination in different environments.     

Finger avulsion injuries: A report of four cases

Injury that occurs to a finger wearing a ring though rare can have grave consequences. It is a preventable injury which has a peculiar mode of trauma that is usually occupational. Injury ranges from simple contusion to degloving of soft tissues to traumatic amputation. We hereby report our experience of four cases of finger avulsion injuries due to a ring and discuss their variable clinical presentation and individualized management.     

E-selectin supports neutrophil rolling in vitro under conditions of flow.

E-selectin was evaluated for its ability to support neutrophil adhesion under conditions of flow. At a wall shear stress of 1.85 dyn/cm2, neutrophils were found to attach to E-selectin expressed on the apical surface of L cell monolayers. The initial intercellular contact was most often evidenced by neutrophils rolling on the monolayer at a mean rate of congruent to 10 microns/s. Anti-E-selectin monoclonal antibody, CL2/6, inhibited this interaction by > 90%. Rolling neutrophils often transiently stopped, but in contrast to the behavior on stimulated endothelial cells, they remained spherical in shape and did not migrate on or beneath the monolayer. A possible contribution of neutrophil L-selectin to this interaction was indicated by the findings that anti-L-selectin monoclonal antibody, DREG-56, inhibited E-selectin-dependent adhesion under flow by > 65%, and there was a highly significant correlation between surface levels of L-selectin and E-selectin-dependent adhesion under flow. E-selectin also appeared to support neutrophil adhesion to IL-1 beta-stimulated endothelial cells under conditions of flow, but it accounted for only congruent to 30% of the level of adherence, in contrast to L-selectin which accounted for > 65%. Thus, both L-selectin and E-selectin can support neutrophil adhesion at wall shear stresses that preclude intercellular adhesion molecule-1-dependent adhesion, and they participate in neutrophil adherence to stimulated endothelial cells under conditions of flow.     

Use of fructosamine test in diabetic children

OBJECTIVE: The goal of this study was to assess the effect of glucose and the contribution of the aldimine component on the measurement of fructosamine, the relationship of serum fructosamine with glycosylated plasma proteins, as measured by a new high-performance liquid chromatography methodology (Glyc PP-HPLC) and by an affinity chromatography (Glyc PP), and the ability of serum fructosamine to assess acute, short-term (1-2 wk), and long-term (2-3 mo) glycemic control. RESEARCH DESIGN AND METHODS: The measurement of fructosamine was unaltered by the addition of up to 27.5 mM glucose or by the elimination of the aldimine component of serum specimens by dialysis. Fructosamine was generated in vitro by incubating serum aliquots. This generation was dependent on time, glucose concentration, and temperature. RESULTS: Fructosamine (n = 27) correlated well with Glyc PP (r = 0.76, P less than 0.01) and significantly less with Glyc PP-HPLC (r = 0.46, P less than 0.01). Although oral glucose ingestion increased serum glucose acutely by 200%, fructosamine was unchanged at each time interval. Improving glycemic control decreased the mean serum fructosamine concentration from 3.68 (baseline) to 3.28 mM (P less than 0.01) at 1 wk and to 3.13 mM (P less than 0.01) at 2 wk. HbA1c correlated with fructosamine (r = 0.59) and Glyc PP-HPLC (r = 0.47) but correlated best with Glyc PP (r = 0.83). CONCLUSIONS: These results indicate the fructosamine assay is unaltered by serum glucose, solely measures the ketoamine component, correlates well with glycosylated plasma proteins measured by aminophenylboronic acid column chromatography, is unaffected by acute changes of serum glucose, and may be used to monitor changes in glycemic control over a 1-wk interval.     

Chemotactic factors regulate lectin adhesion molecule 1 (LECAM-1)-dependent neutrophil adhesion to cytokine-stimulated endothelial cells in vitro.

Monoclonal antibodies recognizing CD18, CD11a, CD11b, and neutrophil lectin adhesion molecule 1 (LECAM-1), i.e., the human homologue of the murine MEL-14 antigen, were used to assess the relative contribution of these glycoproteins to neutrophil-endothelial adhesion. Under static conditions, the adhesion of neutrophils to IL-1-stimulated human umbilical vein endothelial cell (HUVEC) monolayers was inhibited by antibodies to CD18, CD11a, and the neutrophil LECAM-1, and the effect of combining anti-LECAM-1 and anti-CD11a was almost additive. Under flow at a wall shear stress 1.85 dyn/cm2, a condition where CD18-dependent adhesion is minimal, anti-LECAM-1 inhibited adhesion by greater than 50%. Chemotactic stimulation of neutrophils induced a rapid loss of LECAM-1 from the neutrophil surface, and the level of neutrophil surface LECAM-1 was closely correlated with adhesion under flow. Neutrophils contacting the activated endothelial cells for 30 min lost much of their surface LECAM-1, a phenomenon induced by a soluble factor or factors released into the medium by the stimulated monolayers, and a high percentage migrated through the HUVEC monolayer. This migration was almost completely inhibited by anti-CD18, but was unaffected by antibodies to neutrophil LECAM-1. These results support the concept that LECAM-1 is a neutrophil adhesion molecule that participates in the adherence of unstimulated neutrophils to cytokine-stimulated endothelial cells under conditions of flow, and is then lost from the neutrophil surface coincident with the engagement of CD18-dependent mechanisms leading to transendothelial migration.     

La maladie de Trevor: à propos de deux nouvelles observations

Trevor’s disease is a rare skeletal developmental disorder affecting the epiphysis in children. It usually affects a lower limb and involves one or more than one epiphysis. We report two new cases of Trevor’s disease of knee and ankle in 8 and 14 years old boys respectively. The treatment was surgical excision. We discuss the modalities of recognition and the treatment of this rare disease.