Fatal esophageal-arterial fistula 17 years following tetralogy of Fallot repair.

Blalock-Taussig shunts (subclavian to pulmonary anastomoses) have remained the most effective palliation in cyanotic heart disease. Late complications are rare but can be devastating. The case of a 26-year-old female with tetralogy and an original Blalock shunt constructed at age four years is reported. Despite subsequent primary repair of the tetralogy and presumed ligation of the Blalock shunt, the patient succumbed to a fatal hemorrhage due to esophageal-arterial fistula involving the Blalock shunt. The circumstances leading to this dramatic outcome are outlined and discussed. It is important for cardiologists caring for congenital heart disease patients to be aware of the late complications of congenital heart surgery, and carry out the proper follow-up investigations.     

The work of walking: a calorimetric study

Experiments were designed to test the traditional assumption that during level walking all of the energy from oxidation of fuel appears as heat and no work is done. Work is force expressed through distance, or energy transferred from a man to the environment, but not as heat. While wearing a suit calorimeter in a respiration chamber, five women and five men walked for 70 to 90 min on a level treadmill at 2.5, 4.6, and 6.7 km.h-1 and pedalled a cycle ergometer for 70 to 90 min against 53 and 92 W loads. They also walked with a weighted backpack and against a horizontal load. During cycling, energy from fuel matched heat loss plus the power measured by the ergometer. During walking, however, energy from fuel exceeded that which appeared as heat, meaning that work was done. The power increased with walking speed; values were 14, 29, and 63 W, which represented 11, 12, and 13% of the incremental cost of fuel above the resting level. Vertical and horizontal loads increased the fuel cost and heat loss of walking but did not alter the power output. This work energy did not re-appear as thermal energy during 18 h of recovery. The most likely explanation of the work done is in the inter-action between the foot and the ground, such as compressing the heel of the shoe and bending the sole. We conclude that work is done in level walking.     

Effects of alterations in left ventricular filling, contractility, and systemic vascular resistance on the ascending aortic blood velocity waveform of normal subjects.

OBJECTIVES: To confirm the consistent effects on Doppler-measured aortic blood flow velocity waveform variables of alterations in left ventricular preload, afterload, and inotropy using pharmacologic and physiologic maneuvers. SETTING: Medical school laboratory. SUBJECTS: Healthy volunteers. INTERVENTIONS: Increasing infusion rates of dobutamine (1.25 to 5 micrograms/kg.min), esmolol (1.25 to 5 mg/min), phentolamine (1.25 to 5 mg/min), methoxamine (1.25 to 5 mg/min), metaraminol (1.25 to 5 mg/min), and placebo (1.25 to 5 mL of 0.9% saline/min) and increasing plasma removal (0.5 to 1 L) in awake, rested, supine subjects. MEASUREMENTS AND MAIN RESULTS: Ascending aortic blood flow was measured by the suprasternal Doppler approach allowing calculation of waveform variables of stroke distance and minute distance (linear measures of stroke volume and cardiac output), peak velocity, mean acceleration and flow time corrected for heart rate. An index of systemic vascular resistance was obtained by dividing mean systemic BP by the minute distance. Inotropic changes predominantly affected peak velocity and mean acceleration. Changes in preload mainly affected the flow time corrected for heart rate, whereas afterload changes had an intermediate effect. Unsuspected but subsequently confirmed hemodynamic effects were seen with esmolol and metaraminol. CONCLUSIONS: Aortic blood flow velocity waveform variables measured by Doppler ultrasound can be used to noninvasively follow changes in left ventricular preload, afterload, and inotropy.     

Changes in alpha 2-adrenoceptors on vascular smooth muscle and neural membranes following hypertension induced by renal ischemia.

alpha 2-Adrenoceptors were characterized on neural and vascular membranes from 2-kidney-1-clip renal hypertensive (RHT) and normotensive (NT) rats. Rats were sacrificed 6 weeks after induction of renal ischemia, and the specific binding of 3H-clonidine to smooth muscle membranes form tail arteries and neural membranes from various brain regions was examined. Additionally, isometric contractions of helically cut tail artery strips produced by various alpha-adrenoceptor agonists were measured. Scatchard analysis indicated an increased number of high-affinity binding sites on the smooth muscle membranes from RHT rats (Bmax = 43.5 +/- 1.4 fmol/mg protein) compared to that from the NT rats (25.4 +/- 3.8 fmol/mg protein). An increased contractile sensitivity to clonidine was also observed in tail artery strips from RHT rats (EC50 for RHT = 3.04 x 10(-8) M; NT = 1.52 x 10(-7) M). In neural tissue, the number of alpha 2-adrenoceptor-binding sites was significantly increased in the locus coeruleus from RHT rats, but not in the amygdala, hypothalamus, parietal cortex, hippocampus or lower brain stem. These results demonstrate that renal ischemia produces changes in both peripheral and neural alpha 2-adrenoceptor density. The increase in smooth muscle alpha 2-adrenoceptors might also provide a partial explanation for the supersensitivity to adrenergic agonists in this model of hypertension.     

SRTR Center-Specific Reporting Tools: Posttransplant Outcomes

Measuring and monitoring performance—be it waiting list and posttransplant outcomes by a transplant center, or organ donation success by an organ procurement organization and its partnering hospitals—is an important component of ensuring good care for people with end-stage organ failure. Many parties have an interest in examining these outcomes, from patients and their families to payers such as insurance companies or the Centers for Medicare and Medicaid Services; from primary caregivers providing patient counseling to government agencies charged with protecting patients.
The Scientific Registry of Transplant Recipients produces regular, public reports on the performance of transplant centers and organ procurement organizations. This article explains the statistical tools used to prepare these reports, with a focus on graft survival and patient survival rates of transplant centers—especially the methods used to fairly and usefully compare outcomes of centers that serve different populations. The article concludes with a practical application of these statistics—their use in screening transplant center performance to identify centers that may need remedial action by the OPTN/UNOS Membership and Professional Standards Committee.     

Long-term results of dietary fenbendazole to eradicate Syphacia muris from rat colonies.

The pinworm Syphacia muris was eradicated from rats after treatment with fenbendazole-medicated chow (150 ppm) and without environmental decontamination for > 54 months. However, this regimen was successful only when the treatment was delivered and efficacy monitoring was done by personnel of the institutional animal resources program. The same pinworm elimination program failed 7 to 24 months after the cessation of treatment in a satellite colony in which animal care, including provision of medicated diet and sample collection for efficacy monitoring, was provided by research personnel. A failure to uniformly deliver adequate therapeutic doses or reinoculation of rats with pinworm eggs from the contaminated environment could not be excluded as causes of the failure. However, there were risk factors, and animal care practices unique to the satellite colony that may have facilitated the re-emergence of pinworms. These risk factors included hand-washing of cages, storage of contact bedding in areas that were not vermin-proof, and animal care provided by personnel having contact with rodents of pet-store origin.     

Plate fixation of open fractures of the tibia

The results of immediate plate fixation of 97 open fractures of the tibial shaft in 95 patients are reported. Significant joint stiffness occurred in 11.4% and angular malunion of greater than 5 degrees in any plane was seen in 3.1%. The infection rate was 10.3%. However, even in those cases which develop delayed union or other complications, plate fixation of open fractures can produce excellent recovery of limb function.