Ventilator-associated pneumonia due to meticillin-resistant Staphylococcus aureus: risk factors and outcome in a large general hospital.

BACKGROUND: Data about risk factors and impact on outcome of methicillin-resistant S. aureus (MRSA) in unselected patients with ventilator-associated pneumonia (VAP) are limited. AIM: To assess predisposing factors and outcome of VAP due to MRSA in a large teaching institution. METHODS: Prospective study carried out over four years in the three adult ICUs of our hospital. Patients with MRSA-VAP were compared with those with bacterial VAP due to other microorganisms. FINDINGS: Overall, 474 episodes of bacterial VAP were collected. Significant differences between MRSA-VAP (111) and VAP due to other microorganisms (363) were found for median age (68 vs. 62 years), median APACHE II score (12 vs. 11), neurosurgery (5.4% vs. 13.8%), abdominal surgery (35% vs. 19%), prior treatment with any antibiotic (82.9% vs. 64.5%) and with imipenem (24% vs. 11%) at present admission before VAP, and pleural effusion (12% vs. 5%). Multivariate analysis adjusted for confounding factors showed that higher APACHE II score, prior treatment with any antibiotic and pleural effusion were independent risk factors for MRSA. As for treatment and outcome, the differences between MRSA-VAP and other VAP were inadequate empiric treatment (70% vs. 53%), median cost of antibiotics per episode (€974 vs. €726), and in-hospital mortality (60% vs. 47%). At multivariate analysis, however, MRSA was not found to be an independent risk factor for mortality. CONCLUSION: MRSA is a common cause of VAP. Underlying conditions predispose to its high mortality.

Negative aging stereotypes and their relation with psychosocial variables in the elderly population.

This study explores whether there is a relationship between the level of belief in negative aging stereotypes in 65-year-old people and their results concerning some psychosocial variables. These were selected for their relevance for health and well being in elderly people. These were: living situation, responsibilities toward others, subjective health, frequency of medical appointments, subjective age, participation in community social activities and regular physical activity. The sample consisted of 757 people of low educational level, ranged from 65 to 96 years. Age and gender were homogeneously distributed. Participants were non-institutionalized people. Firstly, the psychosocial variables under focus were assessed by means of seven questions. Secondly, a questionnaire about negative aging stereotypes (CENVE) was administered. It was composed of three factors: health, motivational-social and character-personality. Results show that a high score in negative stereotypes is significantly associated to the studied variables, except for living situation, showing a worse quality of life (QoL) profile. Results are discussed in terms of their utility for assessment and psychosocial intervention, which is meant to improve health in the elderly.

A comparison between disk diffusion and microdilution for susceptibility testing of Mycobacterium fortuitum complex.

We evaluated a disk diffusion method using Mueller-Hinton agar for susceptibility testing of Mycobacterium fortuitum complex organisms. Ninety-five strains were tested both by broth microdilution and disk diffusion. Global results showed good correlation for all antimicrobials except for clarithromycin and erythromycin. However, when the results were analyzed according to species, correlation was poor except for a few antimicrobials. The analysis of the resistant/susceptible results was good for all the antimicrobials tested except azithromycin and erythromycin. In conclusion, the disk diffusion technique could be useful as a screening technique for some antibiotics, but the results must be confirmed by using an accepted reference technique.

Satellite oligodendrocytes and myelin are displaced in the cortex of the reeler mouse.

The spatial distribution of satellite (perineuronal) oligodendrocytes and myelin was studied in the cortices of normal and reeler mice. In normal mice, satellite oligodendrocytes were concentrated in the inner third of the cortex. In reeler mice, satellite oligodendrocytes were present beneath the pial surface and distributed throughout the width of the cortex. In reeler mice, but not normal mice, myelin was present in patches beneath the pia and distributed throughout the width of the cortex. The abnormal position of satellite oligodendrocytes and myelin coincides with the displacement of neurons and axons in the cortex of reeler mice. These studies indicate that the distribution of cortical oligodendrocytes is influenced by neuronal/axonal position.

Morphological features of degenerating oligodendrocytes in twitcher mice.

The morphological features of degenerating oligodendrocytes in twitcher mice were examined by a modified iron histochemical technique. Oligodendrocytes in twitcher mice were found to have several features distinct from oligodendrocytes in normal mice; swellings at different sites along their processes, swollen soma and an increase in iron-rich, oval structures in their cytoplasm. In addition to changes in oligodendrocyte morphology, endothelial cells in brains of twitcher mice were found to be highly enriched with iron.