AMPA receptor downregulation induced by ischaemia/reperfusion is attenuated by age and blocked by meloxicam.

AIM: Stroke prevalence increases with age, while alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptor (AMPAR) and inflammation have been related to ischaemia-induced damage. This study shows how age and treatment with an anti-inflammatory agent (meloxicam) modify the levels of AMPAR subunits GluR1 and GluR2, as well as the mRNA levels of the GluR2-editing enzyme, ADAR2, in a global brain ischaemia/reperfusion (I/R) model. METHODS: Two days after global ischaemia CA1, CA3, dentate gyrus and cerebral cortex were obtained from sham-operated and I/R-injured 3- and 18-month-old Sprague-Dawley rats. Real time polymerase chain reaction, Western blotting and immunohistochemical assays were performed. Meloxicam treatment was assayed on young animals. RESULTS: Data showed that age attenuates the downregulation induced by I/R in the AMPAR subunits GluR1 and GluR2 and modifies the GluR1/GluR2 mRNA level ratio in a structure-dependent way. The study of the ADAR2 mRNA levels showed more downregulation in older animals than young ones. Meloxicam treatment prevented the transcriptional arrest induced by I/R. CONCLUSION: Our data suggest that changes in the AMPAR isoforms could be associated with ageing in the different structures studied. Although GluR2 editing seems to be involved in age-dependent vulnerability to ischaemia supporting the 'GluR2 hypothesis', this alone does not explain the differential vulnerability in the different brain regions. Finally, inflammation could play a role in protection from I/R-induced injury.

A simple procedure to perform intravenous injections in the Mongolian gerbil (Meriones unguiculatus).

We describe a simple and feasible procedure for performing intravenous administration of substances in the gerbil. Under light anaesthesia, animals were held in dorsal recumbency and a very small incision of skin, parallel to the femoral vein on the internal side of the thigh, was made. The vein is easily accessible via thin skin incision. An insulin syringe and a 30 G needle were used for the injection. This is an easy and quick method, which, with appropriate anaesthesia, allows rapid recovery.

Diagnosis of renal agenesis in a beagle.

A case of right renal agenesis in a beagle, of interest because of the age of the dog at the time of diagnosis, is described. Physical, haematological, biochemical and urinary examinations, including measurement of endogenous creatinine clearance, were performed to assess renal function. Survey radiography, excretory urography, ultrasonography, computed tomography and nuclear magnetic resonance examinations were also used to confirm the absence of a kidney. The effect of kidney agenesis on renal function, evaluated on the basis of endogenous creatinine clearance, is discussed together with the benefits of the various imaging techniques to enable in vivo detection of renal abnormalities.

Tricuspid annuloplasty and ventricular plication for Ebstein's malformation.

BACKGROUND: Seven patients with the diagnosis of Ebstein's malformation of the tricuspid valve were operated on. Mean age was 12 years (range, 7 to 16 years). All were cyanotic, with severe tricuspid regurgitation. Thromboembolism was not present. No associated cardiac malformations were present. METHODS: Surgical repair included tricuspid annuloplasty associated with longitudinal plication of the atrialized portion of the right ventricle. This was attained by approximating the anterior-posterior commissure with either the posterior-septal commissure or the septal leaflet remnant. The thin atrialized ventricular wall thus excluded remained as a cul du sac and was plicated by suturing along the longitudinal axis of the heart. When present, the dysplastic posterior leaflet was included in the plication. In essence, a monocuspid right atrioventricular valve was fashioned out of the anterior leaflet. The remaining septal leaflet played a minimal functional role. No additional procedures for treatment of arrhythmia were associated with the technique described. RESULTS: The postoperative course was uneventful in all patients. Mean follow-up is 4.3 years (range, 1 to 10 years). Doppler echocardiographic studies reveal satisfactory monocusp valve function in all patients, with adequate coaptation of the anterior leaflet and the septal structures. CONCLUSIONS: This technique seems applicable to most forms of Ebstein's malformation and is reproducible. The technique relies on the adequate mobilization of the anterior leaflet. Occasionally it is necessary to free fibrous adhesions of the leaflet to the underlying ventricular surface.

Repair of corrected transposition associated with ventricular septal defect and pulmonary stenosis.

Five patients with the diagnosis of classically corrected transposition of the great arteries, ventricular septal defect (VSD), and pulmonary outflow tract obstruction underwent surgical repair. A variant of a previously described technique was used to avoid injury to conduction tissue. Through an incision into the anatomical left ventricle, the VSD patch was sutured inferiorly to the right and away from the edges of the defect and superiorly to the epicardial border of the ventriculotomy. The pulmonary artery was opened, and its proximal end was closed with a suture. A pouch containing the conduction tissue was therefore obtained. Pulmonary ventriculoarterial continuity was reestablished using a valved or nonvalved Dacron or pericardial conduit. The postoperative course of the patients was uneventful. No changes were demonstrated on comparison with preoperative cardiac rhythm. Good hemodynamic performance was noted in 2 patients in whom postoperative catheterization was performed.