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Biomedical subjects

D M Schmitt

Publications and source records attributed to D M Schmitt.

5 recordsLinked to original sources
PubMed2004

Effect of an acute bout of soccer heading on postural control and self-reported concussion symptoms.

Our purpose was to determine if an acute bout of heading soccer balls adversely affected postural control and self-reported symptoms of cerebral concussion. Thirty-one college-aged soccer players were randomly placed into either a kicking group or a heading group. Subjects either kicked or headed 18 soccer balls over the course of 40 minutes. Subjects had their postural control assessed while standing on a force plate and completed a concussion symptoms checklist on three separate occasions: prior to, immediately following, and 24 hours after kicking or heading. There were no significant differences between the heading and kicking groups on the postural control measures prior to, immediately following, and 24 hours after kicking/heading. The heading group did, however, report significantly more concussion symptoms than the kicking group immediately after heading, but not 24 hours after heading. The number of previous concussions sustained by subjects did not influence the effects of heading. An acute bout of soccer heading appears to cause an increase in self-reported symptoms of cerebral concussion lasting less than 24 hours but no quantifiable deficits in postural control. Further research is needed to investigate the cumulative effects of soccer heading on postural control and other objective measures of brain function.

Adult↗
PubMed2001

Intron dynamics and the evolution of integrin beta-subunit genes: maintenance of an ancestral gene structure in the coral, Acropora millepora.

We have determined the genomic structure of an integrin beta-subunit gene from the coral, Acropora millepora. The coding region of the gene contains 26 introns, spaced relatively uniformly, and this is significantly more than have been found in any integrin beta-subunit genes from higher animals. Twenty-five of the 26 coral introns are also found in a beta-subunit gene from at least one other phylum, indicating that the coral introns are ancestral. While there are some suggestions of intron gain or sliding, the predominant theme seen in the homologues from higher animals is extensive intron loss. The coral baseline allows one to infer that a number of introns found in only one phylum of higher animals result from frequent intron loss, as opposed to the seemingly more parsimonious alternative of isolated intron gain. The patterns of intron loss confirm results from protein sequences that most of the vertebrate genes, with the exception of beta4, belong to one of two beta subunit families. The similarity of the patterns within each of the beta1,2,7 and beta3,5,6,8 groups indicates that these gene structures have been very stable since early vertebrate evolution. Intron loss has been more extensive in the invertebrate genes, and obvious patterns have yet to emerge in this more limited data set.

Amino Acid Sequence↗