Topiramate promotes neurological recovery in a new model of traumatic brain injury in rats.

The aim of this study is to investigate the neuroprotective effects of the anticonvulsant topiramate in a new model of traumatic brain injury in rats. A new model of traumatic brain injury, based on the weight-drop technique, was developed for the purpose of this study. Seventy-five male Wistar rats weighing 320-470 g were studied. All rats were anesthetized, subsequently submitted to a round craniectomy in the left parietal region and a weight of 50 g was used for the production of a cortical contusion. In study I, 44 rats were randomized in three groups to receive either topiramate 40 mg/kg (n=13), topiramate 60 mg/kg (n=14), or water for injection (n=17) i.p. 30 min after the injury and every 12 h thereafter for 3 days. The rats were tested clinically 24 h, 72 h, 10 days and 20 days after the injury. On day 21 the animals were sacrificed and the brains were removed and prepared for histopathological analysis. In study II, 19 rats were randomized to receive either topiramate 60 mg/kg (n=10) or water for injection (n=9) i.p. 30 min after the injury and every 12 h (four doses in total). 48 h after the injury the animals were sacrificed and the brains were rapidly removed and analyzed for water content with the dry-wet weight technique. The animals that received topiramate performed significantly better in neurological tests compared to the animals that received vehicle ten (P<0.05) and 20 (P<0.001) days after the injury. There was no difference between the high and the low dose of the drug. Topiramate had no effect on the anatomic volume of the lesion. The animals that received topiramate had a tendency to present with less cerebral edema formation, but the difference was not statistically significant (P>0.05). These findings suggest that topiramate promotes neurological recovery in rats after traumatic brain injury without affecting the final size of the traumatic lesion and that it might play a role in the reduction of post-traumatic cerebral edema.

A five-year clinical experience with 112 Blalock-Taussig shunts.

In spite of recent advances in neonatal open repair for complex cyanotic heart disease, some patients require palliation with a systemic-to-pulmonary artery shunt. We report a 5-year experience (1985-1990) with 112 Blalock-Taussig shunts. Forty-six of the 92 patients had some variant of tetralogy of Fallot, with a wide spectrum of diagnoses in the remainder. The median age at surgery was 3 months. A classic Blalock-Taussig shunt was done in 26% (group I), and a 4- or 5-mm PTFE graft was utilized in the remainder (group II). The technical aspects of each of the procedures are reviewed. There were three early deaths in the entire group, none of them related to Blalock-Taussig shunt function. There was no incidence of early shunt insufficiency, bleeding, infection, limb ischemia, or pulmonary artery distortion. There was a 21% incidence of clinical congestive heart failure, seen somewhat more commonly in group I. The overall need for reshunting/open repair was similar in both groups, but there was a statistically longer interval between the initial Blalock-Taussig shunt and the second procedure in group I (21.6 vs 12.4 months). The Blalock-Taussig shunt remains a safe, reliable, and effective means of increasing pulmonary flow.

Aortic root blood flow increases after pancuronium in neonates with hyaline membrane disease.

OBJECTIVE: To determine the effects of muscle paralysis on aortic root blood flow in preterm infants with hyaline membrane disease. DESIGN: Each patient served as his/her own control in a prospectively controlled trial. SETTING: Neonatal ICU in a university hospital. PATIENTS: Ten ventilator-dependent preterm infants weighing 800 to 2820 g, 0 to 8 days of age, with hyaline membrane disease and seven control patients. INTERVENTIONS: Noninvasive measurement of aortic root blood flow by Doppler echocardiography 30 min before and 60 min after respiratory paralysis with 0.1 to 0.5 mg/kg of iv pancuronium, or following ventilator changes in control subjects. RESULTS: Mean aortic root blood flow increased significantly (p less than .001), from 212 to 276 mL/min.kg, accompanied by significant increases in stroke volume and heart rate. CONCLUSIONS: Pancuronium bromide may have a direct beneficial effect on the circulation of preterm infants with hyaline membrane disease.

Increased blood viscosity and tachypnoea in infants of diabetic mothers.

Tachypnoea was significantly more common in class B than in class A or C infants of diabetic mothers. Whole blood viscosity at a standardised packed cell volume and moderately low shear rate was significantly higher in infants of diabetic mothers with tachypnoea than in those without tachypnoea or healthy controls.