Joseph J. Amato

High velocity missile injury: An experimental study of the retentive forces of tissue

Abstract Wound ballistics is defined as the study of the motion of missiles within the tissues. To understand tissue destruction we must realize that the severity of injury depends on an intricate balance of the action of the missile and the reaction of the tissues. The mass, shape, and velocity of the bullet and the change in presented area are the major factors that render destruction to the tissues. Our studies of the mechanism of injury to various tissues such as the muscle, liver, lungs, and bone have demonstrated graphically the formation of a temporary cavity within these tissues and the sequence of events that occur within these isolated tissues. The size of the temporary cavity is proportionate to the specific gravity of the tissues and to the severity of the injury. However, the elasticity and cohesiveness of the tissue counteract the expansion of the wound tract and absorb the deposition of kinetic energy by the missile. The tissues with a more cohesive structure and with large amounts of elastic tissue consequently demonstrate a greater resistance to injury.

Anaesthetic management of a patient with erythropoietic protoporphyria for ventricular septal defect closure

Erythropoietic protoporphyria (EPP) is due to a deficiency in ferrochelatase required for haem synthesis. We describe the anaesthetic management of a seven‐year‐old with EPP undergoing closure of a haemodynamically significant ventricular septal defect. Photosensitivity in EPP patients is triggered at wavelengths near 400 nm and light‐excited porphyrins generate free radicals and singlet oxygen that lead to erythrocyte deformity and haemolysis. Stimuli that could trigger a porphyric crisis during anaesthesia and surgery were reduced by avoiding exposure to the sensitive 400 nm spectrum and using light sources covered with yellow acrylate filters in the operating room. Anaesthetic agents not previously associated with porphyric crisis were chosen. Whole blood priming of the extracorporeal circuit was performed to ensure adequate haemoglobin concentrations during the perioperative period.

Zinc sulfate-failure as an accelerator of collagen biosynthesis and fibroblast proliferation.

Summary The effect of zinc sulfate on collagen biosynthesis and fibroblast proliferation has been studied in a tissue culture model system using human skin fibroblasts. Addition of zinc sulfate to newly established (low density) cultures in concentrations of 10-4 to 10-8 M results in concentration-dependent cytotoxicity with inhibition of collagen biosynthesis, as well as cellular proliferation. Zinc sulfate at 10-4 to 10-7 M added to confluent (high density) cultures does not influence cellular proliferation, but results in selective inhibition of collagen biosynthesis at the 10-4 M concentration. Lower concentrations of zinc sulfate (10-5 to 10-7 M) do not affect collagen biosynthesis in high density cultures. The results show that zinc does not have a direct acceleratory effect on either cellular proliferation or collagen biosynthesis in human skin fibroblasts in vitro.

Flexible Fiberoptic Bronchoscopy

Abstract The flexible fiberoptic bronchoscope has become an invaluable diagnostic and therapeutic instrument in the management of pulmonary disease. Advantages over the conventional rigid bronchoscope include airway examination to the subsegmental level, increased accuracy of diagnosis in pulmonary malignancy, patient comfort, ease of bedside examination, and atraumatic aspiration of postoperative secretions. Disadvantages include cost, inability to remove foreign bodies, and lack of a satisfactory technique for infant endoscopy. The extended range of diagnostic and therapeutic capabilities of the flexible bronchoscope makes it an important instrument for the thoracic surgeon.

Aortic gunshot injury and paraplegia: preoperative definition with arteriography and computerized axial tomography.

Computerized axial tomography provided the diagnosis for an evolving paraplegia in a patient with a gunshot wound of the descending thoracic aorta. Successful surgical management of the aortic injury and considerations regarding the paraplegia are presented. We do not advocate arteriography and computed tomography routinely in major vascular injuries; however, in clinically stable patients with a high suspicion of associated injuries, use of both can be useful.