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T Leach

Publications and source records attributed to T Leach.

4 recordsLinked to original sources
PubMed1997

Head, neck, and facial injuries in ice hockey: the effect of protective equipment.

OBJECTIVES: To determine the factors and behaviors associated with facial, head, and/or neck injuries to those engaged in ice hockey; the use of protective equipment was also examined. DESIGN: Prospective case series. SETTING: Emergency Department of Sudbury General Hospital. PATIENTS: All patients presenting to the emergency department with a head, neck, or facial injury while playing hockey between the months of October and March 1993-94 and 1994-95 were included in the study. Physicians completed data forms on each patient. Information was validated by review of the emergency-room records; further information was obtained by telephone. RESULTS: A total of 226 patients were identified with ice-hockey-related head, neck, or facial injuries. Most injuries involved males (99%), and the mean age of patients was 23.9 (range, 4-63). Injuries occurred most frequently to the face [192 (85%)]. Many of the injuries were minor, with a mean injury severity score of 1.5 (range, 1-25). However, three patients (1%) required hospital admission, and one teenager suffered a serious spinal fracture. Protective facial hockey equipment use was low in our sample, except among younger injured players. Most of the facial injuries occurred in mature athletes playing recreational hockey. Full facial protection reduced the chance of upper facial injury (p = 0.0001), but the risk of such injury while wearing a half-visor was the same as while wearing no facial protection at all (p > 0.05). From the current study, we estimate that these hockey injuries result in approximately 2.7-3.0 million dollars of direct acute-care medical expenditure per year in emergency departments throughout Ontario. CONCLUSIONS: Head, neck, and facial injuries suffered during ice hockey participation are common problems presented to emergency departments. Moreover, serious injuries can occur while playing this sport. Most injuries appear to be preventable, and facial protection appears to be less frequently used, especially by older men, than is currently recommended. Prevention strategies are discussed.

Adolescent↗
PubMed1987

Posttranslational protein modification by polyamines in intact and regenerating nerves.

A 150,000-g supernatant from axoplasm of the giant axon of the stellate nerve of the squid and from rat sciatic and goldfish optic nerves was found to be able to incorporate covalently [3H]putrescine and [3H]spermidine into an exogenous protein (N,N'-dimethylcasein). Incorporation of radioactivity was inhibited by CuSO4, a specific inhibitor of transglutaminases, the enzymes mediating these reactions in other tissues. Analysis of pH and temperature range and enzyme kinetics displayed characteristics predicted for transglutaminase-mediated reactions. Transglutaminase activity increased during regeneration of both vertebrate nerves, but greater activity was found in segments of nerve containing no intact axons than in either intact segments or in segments containing regenerating axons. Polyacrylamide gel electrophoresis of endogenous modified proteins (in the absence of N,N'-dimethylcasein) showed labeling of 18-, 46- and 200-kilodalton proteins by both [3H]putrescine and [3H]spermidine. Analysis of the protein-bound radioactivity from intact and regenerating rat sciatic nerves demonstrated it to be predominantly in the form of the parent radioactive polyamine. These experiments demonstrate the covalent modification of proteins by polyamines at low levels in squid axoplasm and at relatively higher levels in rat sciatic and goldfish optic nerves. In the latter two cases, the activity of these modification reactions may be due in part to the modification of axonal proteins, but the majority of the activity occurs in nonneuronal cells of the nerve.

Animals↗
PubMed1986

Posttranslational protein modification by amino acid addition in regenerating optic nerves of goldfish.

Previous experiments have demonstrated that 4S RNA, (tRNA), is transported axonally during the reconnection and maturation of regenerating optic nerves of goldfish. The present experiments were performed to determine if tRNA is transported axonally during elongation of these regenerating nerves and whether, as has been demonstrated in other systems, it participates in posttranslational protein modification (PTPM). [3H]Uridine was injected into both eyes of fish with intact optic nerves and 0, 2, 4, or 8 days after bilateral optic nerve cut. Fish were killed 2 days after injection, and [3H]RNA was isolated from retinae and nerves by phenol extraction and ethanol precipitation. [3H]RNA was fractionated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Although the percentage of [3H]4S RNA remained constant in all retinal and control nerve samples, regenerating nerves showed a twofold increase by 6 days after injury, suggesting that [3H]4S RNA is transported axonally in regenerating nerves as early as 6 days after injury. In other experiments, the 150,000-g supernatant of optic nerves was analyzed for incorporation of 3H-amino acids into proteins. No incorporation of 3H-amino acid was found in the soluble supernatant, but when the supernatant was passed through a Sephacryl S-200 column (removing molecules less than 20,000 daltons), [3H]Arg, [3H]Lys, and [3H]Leu were incorporated into proteins. This posttranslational addition of amino acids was greater (1.4-5 times for Lys and 2-13 times for Leu) in regenerating optic nerves than nonregenerating nerves, and the growing tips of regenerating nerves incorporated 5-15 times more [3H]Lys and [3H]Leu into proteins than did the shafts.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acids↗