Multiple coronary embolisms in a woman with risk factors for thromboembolic disease

We report the case of a 33-years-old woman, smoker and taking oral contraceptives, who presented to the emergency room with an anterior ST-elevation myocardial infarction. Thrombolytic treatment was initiated and a few minutes after, chest pain returned and an inferior ST-segment-elevation infarction was diagnosed at that moment. Catheterization revealed multiple embolic occlusion of coronary branches. We discuss tests performed and pathophysiology of myocardial infarction in this patient.     

The release of gentamicin from acrylic bone cements in a simulated prosthesis-related interfacial gap

Gentamicin is added to polymethylmethacrylate bone cements in orthopedics as a measure against infection in total joint arthroplasties. Numerous studies have been published on gentamicin release from bone cements, but none have been able to estimate the local concentrations in the prosthesis-related interfacial gap, present after implantation. The aim of this study was to develop a method allowing determination of antibiotic release in such a gap. Two-hundred-micrometer-wide gaps with a volume of 6 microl and a surface area of 0.6 cm2 were created by inserting stainless-steel strips in gentamicin-loaded bone cement plugs prior to polymerization. After hardening, the gap surface was exposed to 6 microl or 10 ml of phosphate-buffered saline. Within 2 h, gentamicin concentrations in the gaps reached around 4000 microg/ml for 4 different CMW and Palamed cements and 2500 microg/ml for Palacos R. Concentrations measured in the larger volume were several hundred times lower than in the gaps. This simulated prosthesis-related interfacial gap model offers new insights in the clinical efficacy of antibiotic-loaded bone cements. It is demonstrated that concentrations up to 1000-fold the antibiotic resistance levels for most bacterial strains causing implant infection can be achieved in a realistic in vitro model.     

A 7-year study of severe hospital-acquired pneumonia requiring ICU admission

Objective To examine the characteristics, prognostic factors, and outcome of patients with severe hospital-acquired pneumonia admitted to the ICU.Design and setting Prospective observational clinical study in two medical-surgical ICUs with 16 and 20 bedsPatients and participants During a 7-year period all hospitalized patients requiring admission to either ICU for hospital-acquired pneumonia were followed up.Measurements and results We diagnosed 96 episodes of severe hospital-acquired pneumonia, and in 67 cases a causal diagnosis was made. Most episodes were late-onset pneumonia. Gram-negative micro-organisms were isolated in 51% of episodes diagnosed, and Pseudomonas aeruginosa was the most frequent pathogen isolated (24%). Clearly significant variations happened between hospitals, particularly affecting the incidence of Aspergillus spp. and Legionella pneumophila. Forty-nine patients developed septic shock (51%). Fifty-one patients died (53%). Aspergillosis and pneumonia due to P. aeruginosa were associated with the highest mortality. Septic shock (OR: 14.27) and chronic obstructive pulmonary disease (OR: 6.11) were independently associated with a poor prognosis.Conclusions Patients with severe hospital-acquired pneumonia admitted to the ICU present high mortality. The presence of septic shock and chronic obstructive pulmonary disease in conjunction with specific microorganisms are associated with a poor prognosis. Local epidemiological data combined with a patient-based approach may allow a more accurate therapy decision making.     

Simultaneous identification of Mycobacterium genus and Mycobacterium tuberculosis complex in clinical samples by 5'-exonuclease fluorogenic PCR

Early diagnosis of tuberculosis and screening of other mycobacteria is required for the appropriate management of patients. We have therefore developed a 5'-exonuclease fluorogenic PCR assay in a single-tube balanced heminested format that simultaneously detects Mycobacterium tuberculosis complex (MTC) and members of the Mycobacterium genus (MYC) using the 16S ribosomal DNA target directly on clinical samples. One hundred twenty-seven clinical samples (65 smear negative and 62 smear positive) with a positive culture result from 127 patients were tested, including 40 negative control specimens. The finding of both a positive MTC and probe value and a positive MYC probe value confirmed the presence of MTC or mycobacteria with a 100% positive predictive value. However, a negative value for MTC or MYC did not discount the presence of mycobacteria in the specimen. Interestingly, the addition of the MYC probe allowed the diagnosis of an additional 7% of patients with tuberculosis and rapid screening of nontuberculous mycobacteria (NTM). Thus, over 75% of the patients were diagnosed with mycobacterial disease by PCR. The sensitivity was much higher on smear-positive samples (90.3%) than smear-negative samples (49.2%) and was slightly higher for MTC than NTM samples. With regard to the origin of the sample, MTC pulmonary samples gave better results than others. In conclusion, we believe this test may be useful for the rapid detection of mycobacteria in clinical samples and may be a valuable tool when used together with conventional methods and the clinical data available.     

Human monocyte scavenger receptors are pattern recognition receptors for (1-->3)-beta-D-glucans

Glucans are cell wall constituents of fungi and bacteria that bind to pattern recognition receptors and modulate innate immunity, in part, by macrophage activation. We used surface plasmon resonance to examine the binding of glucans, differing in fine structure and charge density, to scavenger receptors on membranes isolated from human monocyte U937 cells. Experiments were performed at 25 degrees C using a biosensor surface with immobilized acetylated low density lipoprotein (AcLDL). Inhibition of the binding by polyinosinic acid, but not polycytidylic acid, confirmed the interaction of scavenger receptors. Competition studies showed that there are at least two AcLDL binding sites on human U937 cells. Glucan phosphate interacts with all sites, and the CM-glucans and laminarin interact with a subset of sites. Polymer charge has a dramatic effect on the affinity of glucans with macrophage scavenger receptors. However, it is also clear that human monocyte scavenger receptors recognize the basic glucan structure independent of charge.