Effect of diazepam on digitalis-induced ventricular arrhythmias in the cat

The capacity of diazepam to counteract cardiac arrhythmias was studied in barbiturate-anesthetized cats treated with digitalis (i.e., deslanoside, 25 μg/kg given every 15 min iv). Diazepam dissolved in commercial propylene glycol solvent was administered in repeated doses of 10 mg iv at approximately 45-sec intervals to five animals exhibiting deslanoside-induced ventricular arrhythmias. Conversion of the arrhythmia to sinus rhythm was observed in two animals, while development of more serious rhythm changes was observed in the other three animals. One explanation for the deleterious effect seen with diazepam in the three animals is that the solvent itself may produce significant cardiocirculatory changes. To test this possibility, seven animals were intoxicated with deslanoside and the diazepam solvent was administered in doses of 1.0 ml every 45 sec until a total dose of 5.0 ml was given. In each animal, the administration of the solvent was associated with the development of more serious rhythm changes. Ventricular fibrillation (VF) developed 10.8 ± 1.6 min after the onset of deslanoside-induced ventricular tachycardia (VT). The corresponding time interval between deslanoside-induced VT and VF was 26.7 ± 5.0 min when no solvent was administered. These results indicate that propylene glycol solvent is deleterious to cardiac rhythm and should not be employed as a vehicle for antiarrhythmic drugs.     

Perinatal management of gastroschisis: analysis of a newly established clinical pathway

Purpose

The authors developed a clinical pathway for optimal management after antenatal diagnosis of gastroschisis. This is the outcomes analysis of our first 30 consecutive patients.

Method

Antenatal counseling was provided for all families with in-utero diagnosis of gastroschisis. Bowel dilatation, thickness, motility, amniotic fluid volume, and fetal development were followed by ultrasonography every 4 weeks. Babies were delivered by cesarean section between 36 and 38 weeks gestation if the lungs were mature or earlier for bowel complications. Gastroschisis repair was scheduled 90 minutes after birth. Primary repair was attempted in all through the abdominal wall defect without an additional incision, resulting in an umbilicus with no abdominal scar.

Results

Primary repair was achieved in 83%. Babies needed assisted ventilation for 3 days, reached full feeds by 19 days, and were discharged by 24 days (all medians). There were 3 (10%) deaths, all after staged repair.

Conclusions

Our new protocol of both scheduled elective cesarean section and early gastroschisis repair resulted in a higher proportion of primary repair, shorter duration of mechanical ventilation, earlier full feeds, and shorter length of stay. There was no increase in mortality or morbidity. The primary-repair babies had no mortality and had excellent cosmesis.     

Biliary dyskinesia: the most common indication for cholecystectomy in children

BACKGROUND: The purpose of this study is to examine the current indications for cholecystectomy in children and to evaluate the results after such surgery. METHODS: Retrospective analysis of 107 consecutive cholecystectomies performed in children at the Children's Hospital of Illinois between October 1998 and September 2003. Hospital medical charts and outpatient clinic charts were reviewed. Patients' families were contacted by telephone to obtain longer-term follow-up. Results were analyzed with SPSS 12.0 for Windows (SPSS Inc, Chicago, Ill). RESULTS: Biliary dyskinesia (BD) was the indication for surgery for 62 (58%) of the 107 children who underwent cholecystectomy during the study period. Gallbladder calculus (GC) disease was the next most common indication with 29 (27%) children. The duration of symptoms was longer for BD. The most common presenting symptom in both groups was abdominal pain. Food intolerance was reported by 45% of patients with BD, significantly higher than patients with GC. Mean length of stay after cholecystectomy was 17 hours and 45 hours for BD and GC, respectively. Short-term follow-up showed relief or improvement of symptoms in 85% of children with BD and in 97% with GC. There were no deaths. Two (1.9%) children of the total of 107 developed complications; both had intra-abdominal abscesses. Most patients had complete or considerable long-term improvement in symptoms. CONCLUSIONS: Biliary dyskinesia was the most common indication for cholecystectomy in children in our study. More than half of the surgeries were performed on an outpatient basis. Morbidity was minimal and mortality was zero. We had satisfactory short- and long-term symptom resolution with long-term patient satisfaction reaching 95%.     

d-Amphetamine-induced increase in catecholamine synthesis in the corpus striatum of the rat: Persistence of the effect after tolerance

Summary The effect ofd-amphetamine onin vivo catecholamine synthesis in four regions of rat brain was determined by measuring the accumulation of dopa after inhibition of dopa decarboxylase. In doses up to 2.5 mg/kg,d-amphetamine caused dose-dependent increases in striatal dopa accumulation to a maximum of 280% of control; further increases in dose resulted in smaller effects until 10 mg/kgd-amphetamine was not significantly different from control.d-Amphetamine did not alter dopa accumulation in telencephalon, in diencephalon-mesencephalon, or in pons-medulla oblongata.d-Amphetamine did not affect either dopamine levels in striatum or NE levels in pons-medulla oblongata; at high doses,d-amphetamine did reduce norepinephrine levels in telencephalon and in diencephalon-mesencephalon.Daily administration of pre-session but not of post-sessiond-amphetamine produced tolerance to the effects ofd-amphetamine on milk consumption in rats. The ability ofd-amphetamine to increase striatal catecholamine synthesis was not altered by the development of tolerance tod-amphetamine. These results suggest that tolerance tod-amphetamine is not related to its effect on catecholamine synthesis but instead occurs via changes in aspects of catecholamine metabolism other than synthesis via change in catecholamine release, reuptake, or receptor sensitivity, or via changes in non-catecholaminergic mechanisms.This research was supported by U.S. Public Health Service National Institute of Mental Health Grant MH-011191-12.Supported by Training Grant USPHS 2 TO5 GM 01939-07 (MSTP).Supported by Research Career Development Award 5 KO2 MH-10562-01.