Local and cortical effects of olfactory bulb lesions on trophic support and cholinergic function and their modulation by estrogen.

This study determined whether olfactory bulb lesions would affect trophic support to its afferent, the horizontal limb of the diagonal band of Broca (hIDBB), and if estrogen would ameliorate the effects of neural injury in this circuit. NMDA injections into the olfactory bulb resulted in neural injury as indicated by cell loss and increased glial fibrillary acidic protein immunoreactivity. Olfactory bulb lesions severely reduced BDNF expression in its afferent, the hIDBB, while NGF was only reduced in lesioned animals deprived of estrogen. In the olfactory bulb itself, lesions increased BDNF expression, but not NGF. Paradoxically, bulb lesions up-regulated both NGF and BDNF in another target of the hIDBB, the cingulate cortex. Moreover, olfactory bulb lesions affected choline uptake and ChAT activity locally, as well as in the cingulate cortex. Estrogen significantly attenuated the lesion-induced loss of choline uptake in the cingulate cortex, but not at the primary lesion site. Collectively, these results indicate that neural injury to one limb of the forebrain cholinergic system may result in collateral damage to other limbs of this system, suggesting a mechanism for the progression of neurodegenerative diseases, such as Alzheimer's disease, that involve the cholinergic system. Furthermore, these data also indicate that estrogen selectively attenuates certain lesion-induced deficits.

Beneficial effects of an open artery on left ventricular remodeling after myocardial infarction.

During the last 2 decades researchers have developed a clearer understanding of the pathophysiology of acute myocardial infarction (AMI). The use of thrombolysis and coronary angioplasty early in the course of AMI salvages myocardium and preserves left ventricular function, which results in improved survival rates. Late reperfusion after AMI, however, may provide beneficial effects on long-term prognosis, especially owing to attenuation of left ventricular remodeling. This article reviews the evidence of the benefits of an open infarct-related artery on left ventricular remodeling after AMI.

The clinical application of a fetal membrane on a diabetic patient's injury.

A description of the successful use of a fetal membrane in the recovery of a injured patient is presented. A diabetic female patient, 63 years old, was accidentally injured with a winnowing fork, which opened the skin of the front side of her left foot. For first two weeks, she was submitted to a treatment involving antibiotics, analgesics and antiinflammatories, but the infection did not disappear and the pain was almost unbearable. At the end of the third week, the injury underwent surgical washing with epidural blockage; suitable insulin dose and oral antidiabetics controlled the high-glucose concentration. However, due to the intensity of the pain, a risky epidural blockage was administered every four hours for 12 days. Finally, a radiosterilised human fetal membrane, which was collected at HCSAE and processed at ININ, was used as a biological wound dressing. Biological control of the tissue was performed at Facultad de Química de la Universidad Nacional Autónoma de México (The Chemistry Faculty of the National Autonomous University of Mexico) (UNAM). As a result, the pain first diminished and then stopped. The healing process started in a few days and led to a complete recovery in 2 1/2 months. At present, the patient is in good condition, living a normal life.

[Usefulness of exercise test in programming dual chamber pacemakers]. / Utilidad de la prueba de esfuerzo en la programación de los marcapasos bicamerales.

Prospectively, we studied 42 patient to evaluate the usefulness of treadmill exercise to programme pacemaker DDD in relation to the functioning upper frequency (relation between block frequency of pacemaker and the upper rate frequency). We excluded patient who had no treadmill exercise test after implant pacemaker. During stress 7 (17%) patient presented AV conduction 1:1 (group I); 16 (38%) second degree AV block type Wenckebach (group II); 14 (33%) second degree AV block 2:1 (group III); and 5 (12%) showed inhibition of the pacemaker by intrinsic activity (group IV). Block frequency of the pacemaker in group I and II was superior in regard of the upper rate frequency, 156.85 +/- 22.16 vs 141.43 +/- 20.82 and 135.25 +/- 11.54 vs 121.25 +/- 5.9, respectively. In group III and IV, it was lower, 120.36 +/- 15.31 vs 138.57 +/- 13.29 and 121.0 +/- 7.38 vs 142.0 +/- 14.39. The comparative analysis of the block frequency of the pacemaker in relation with the upper rate frequency showed statistically significant differences (p < 0.05) between groups I and II, and between the group I and III. The appearance of second degree AV block 2:1 is nonphysiologic, is rather due to an abrupt falling in the cardiac output. This phenomenon is able to be predicted and corrected by programming with the use the telemetry with parameters as the AV delay, as well as upper rate frequency and post-ventricular refractory atrial period.

[Radiofrequency ablation in the treatment of supraventricular tachyarrhythmia. Experience with 500 consecutive patients]. / Ablación con radiofrecuencia en el tratamiento de las taquiarritmias supraventriculares. Experiencia en 500 pacientes consecutivos.

Several reports have demonstrated that radiofrequency catheter ablation provides effective control of a variety of supraventricular tachyarrhythmias. This report details the results of radiofrequency catheter ablation in 500 consecutive patients with a wide variety of supraventricular tachycardia treated at the Instituto Nacional de Cardiología "Ignacio Chaávez". Tachyarrhythmias were associated with the presence of an accessory pathway in 355 patients (71%). The accessory pathways were capable of both anterograde and retrograde conduction in 220 of cases (60%), only retrograde conduction in 146 (40%), dual accessory pathways were present in 11 patients (2.2%) giving a total of 366 accessory pathways. The mechanism of the arrhythmia was AV nodal reentrant tachycardia in 115 patients (23%). Ablation of the reentrant circuit of atrial flutter within the right atrium was attempted in 15 (15%) patients and a primary atrial tachycardia in 3 patients (0.7%). AV node ablation and permanent pacemaker implantation were performed in 11 patients (2%). Radiofrequency catheter ablation was successful in 312 of 355 (87.9%) patients with accessory pathways 312 of 366 (85.2%) pathways with a complication rate of 6/355 (2%) and a recurrence rate of (12.4%). AV nodal reentry was successfully abolished in 110 of 115 patients by selective ablation of the slow pathway in 92/96 (95.8%) patients and the fast pathway in 18/19 (94.7%) patients. The complication rate of this group was 7/115 (6.0%) with a recurrence rate of 16 patients (12%). The reentrant circuit of atrial flutter was ablated successfully in 13 of 15 patients with recurrent atrial flutter in (27%) patients. 2/3 (66%) primary atrial tachycardia were successfully ablated. Complete AV block was achieved in 11 of 11 patients with atrial fibrillation or flutter treated by AV nodal ablation without complications or recurrence. The results of this series of patients demonstrates the safety and efficacy of radiofrequency ablation for the treatment of a wide variety of supraventricular arrhythmias with high rate of success and low risk of complications.