Natural coral exoskeleton as a bone graft substitute: a review.

Natural coral graft substitutes are derived from the exoskeleton of marine madreporic corals. Researchers first started evaluating corals as potential bone graft substitutes in the early 1970s in animals and in 1979 in humans. The structure of the commonly used coral, Porites, is similar to that of cancellous bone and its initial mechanical properties resemble those of bone. The exoskeleton of these high content calcium carbonate scaffolds has since been shown to be biocompatible, osteoconductive, and biodegradable at variable rates depending on the exoskeleton porosity, the implantation site and the species. Although not osteoinductive or osteogenic, coral grafts act as an adequate carrier for growth factors and allow cell attachment, growth, spreading and differentiation. When applied appropriately and when selected to match the resorption rate with the bone formation rate of the implantation site, natural coral exoskeletons have been found to be impressive bone graft substitutes. The purpose of this article is to review and summarize all the pertinent work that has been published on natural coral as a bone graft including in vitro, animal and clinical human studies. Preliminary report of our own experiments as well as our recommendations on the use of coral are also included.

Snowmobile injuries in northern Newfoundland and Labrador: an 18-year review.

The charts of 310 consecutive patients with snowmobile injuries admitted to Charles S. Curtis Memorial Hospital, St. Anthony, Newfoundland, during the years 1969 through 1986 were reviewed in order to determine the causes and possible ways of prevention of these injuries. There were 237 males and 73 females. Most patients were less than 30 years of age (73%). Drivers represented 57% of the injured. Falling off the machine and collisions were responsible for 60% of the injuries; 3.0% were due to mechanical failure of the snowmobile. The lower limbs and head and neck regions were most commonly affected (42.6 and 27.6%, respectively); less than 10% of the patients were wearing helmets at the time of the accident. We conclude that the human factor was responsible for the majority of the injuries. We recommend enforcement of legislation, intensification of public education about the hazards of driving snowmobiles, and modifications in the design of the engine, especially to provide increased protection for the lower limbs.

The use of long-acting propranolol ('Inderal' LA) in the management of elderly hypertensive patients.

Fifteen elderly patients whose hypertension was controlled by conventional propranolol 80 mg twice a day had their medication changed to one capsule of 'Inderal' LA (160 mg) daily. The blood pressure, heart rate and propranolol concentrations were measured at various time points when the patients were receiving the conventional preparation and these assessments were repeated when the long-acting preparation was administered. Although the heart rate was lower with conventional propranolol than with 'Inderal' LA there was no significant difference in the blood pressure levels. The mean peak blood level of propranolol was, however, significantly lower with 'Inderal' LA compared with conventional propranolol and occurred later. At 12 h the plasma propranolol levels were higher after 'Inderal' LA then following the intake of conventional propranolol (p less than 0.01); there was no difference in the plasma levels at 24 h. The area under the concentration time curve was significantly higher on conventional propranolol. Compared with published data, the plasma levels were higher than those in younger patients. 'Inderal' LA was well tolerated and side effects were minimal.