Structural synaptic remodeling in the perirhinal cortex of adult and old rats following object-recognition visual training.

The ultrastructural features of layer II synapses in the perirhinal cortex of adult (4- to 6-month-old) and old (25- to 27-month-old) rats exposed to a six-session object recognition visual training were investigated by morphometric methods. The comparative analysis showed a higher synaptic numeric density, a lower synaptic average area, and a lower percentage of megasynapses (S > 0.5 microm2) in old trained rats versus controls, and a higher percentage of small (S < 0.15 microm2) junctions in adult trained rats versus controls. The more marked synaptic remodeling underlying memory consolidation in the perirhinal cortex of old rats might reflect a pre-existing lower dynamic status.

[Subacute extrinsic allergic alveolitis with lesion edema]. / Alvéolite allergique extrinsèque suraiguë avec oedéme lésionnel.

BACKGROUND: Extrinsic allergic alveolitis may have a chronic, subacute or acute course. Its fulminant form with interstitial edema is unusual. CASE REPORT: An 11-year-old girl was referred to our intensive care unit because she suffered from high fever. Chest X-rays showed bilateral alveolitis. History revealed home exposure to several birds for many years, and episodes of dyspnea and fever for a few months. Diagnosis of extrinsic allergic alveolitis was confirmed by strongly positive results of precipitins to avian antigens. In addition, a paramyxovirus influenzae was recovered from broncho-alveolar lavage. Treatment, including high dose steroids, hydroxychloroquine, and suppression of antigenic exposure allowed weaning from mechanical ventilation after 50 days. Severe pulmonary restriction was disclosed by lung function testing following weaning and slow improvement occurred 5 months later, despite persistent interstitial lesions on chest X-rays. CONCLUSION: Extrinsic allergic alveolitis may mimic an acute respiratory distress syndrome. Documenting bird exposure in such a case helps to achieve appropriate diagnosis which requires early administration of steroids in order to improve vital and functional prognosis.

Tidal expiratory flow limitation and chronic dyspnoea in patients with cystic fibrosis.

Cystic fibrosis (CF) eventually leads to hyperinflation linked to tidal expiratory flow limitation (FL) and ventilatory failure. Presence of FL was assessed at rest in 22 seated children and adults with CF (forced expiratory volume in one second (FEV1) range: 16-92% predicted), using both the negative expiratory pressure (NEP) technique and the "conventional" method based on comparison of tidal and maximal expiratory flow/volume curves. In addition, chronic dyspnoea was scored with the modified Medical Research Council (MRC) scale. Measurements were made before and 15 min after inhalation of salbutamol. With NEP, FL was present in only three malnourished patients, who had the lowest FEV1 values (16-27% pred) and claimed very severe dyspnoea (MRC score 5). By contrast, an additional seven patients were classified as FL with the conventional method. Six of these patients had little or no dyspnoea (MRC scores 0-1). Salbutamol administration had no effect on the extent of FL, and the concomitant decrease in functional residual capacity (FRC) was too small to play any clinically significant role. This study concluded that in seated patients with cystic fibrosis, expiratory flow limitation is absent at rest, unless the forced expiratory volume in one second is <30% predicted. If present, expiratory flow limitation is associated with severe chronic dyspnoea. The conventional method for assessing expiratory flow limitation is not reliable and bronchodilator administration has little effect on expiratory flow limitation.