This study assesses chronological age of immature individuals from the degree of ossification evident in the foot skeleton. We considered all tarsal and ray bones in various combinations to determine the most sensitive indicators of chronological age. Skeletal maturity was rated according to a subjective but simple scoring system applied to radiographs of normal feet of children of known chronological age. Scales for assessing the primary center of ossification, secondary center of ossification, and state of fusion are defined. In general, as expected, females show earlier onset of skeletal maturity than males; in particular, females in our sample are skeletally mature in most elements beginning 48 months prior to the earliest incidence of skeletal maturity in males for the same bones. Females in our sample show a marked tendency toward skeletal maturity of all elements by 150 months of age, while males do not show the same tendency until approximately 200 months of age. In general within each sex, consecutive states of fusion show broad overlap in range of chronological age within each bone. Combining scores from several different bones enables a reasonable estimate of potential age in a test application of the model.

In a previous study (Xu, Z., Vo, L., and Macher, B. A. (1996) J. Biol. Chem. 271, 8818 -8823), a domain swapping approach demonstrated that a region of amino acids found in human ␣1,3/4-fucosyltransferase III (FucT III) conferred a significant increase in ␣1,4-FucT acceptor substrate specificity into ␣1,3-fucosyltransferase V (FucT V), which, under the same assay conditions, has extremely low ␣1,4-FucT acceptor substrate specificity. In the current study, site-directed mutagenesis was utilized to identify which of the eight amino acids, associated with ␣1,4-FucT acceptor substrate specificity, is/ are responsible for conferring this new property. The results demonstrate that increased ␣1,4-FucT activity with both disaccharide and glycolipid acceptors can be conferred on FucT V by modifying as few as two (Asn 86 to His and Thr 87 to Ile) of the eight amino acids originally swapped from FucT III into the FucT V sequence. Neither single amino acid mutant had increased ␣1,4-FucT activity relative to that of FucT V. Kinetic analyses of FucT V mutants demonstrated a reduced K m for Gal␤1,3GlcNAc (type 1) acceptor substrates compared with native FucT V. However, this was about 20-fold higher than that found for native FucT III, suggesting that other amino acids in FucT III must contribute to its overall binding site for type 1 substrates. These results demonstrate that amino acid residues near the amino terminus of the catalytic domain of FucT III contribute to its acceptor substrate specificity.␣1,3/4-Fucosyltransferases (FucTs) 1 can bind a wide variety of acceptor substrates (see Ref. 1 and references therein) and catalyze the synthesis of glycoconjugates with different immunological and functional properties including blood group antigens and selectin ligands (2-9). Interestingly, the acceptor substrate specificity of different forms of the human FucTs with highly homologous amino acid sequences can differ significantly (1, 10 -13). For example, FucT III has a very high level of activity with a type 1 disaccharide acceptor (Gal␤1, 3GlcNAc), whereas FucT VI appears to be a true ␣1,3-FucT and utilizes exclusively type 2 acceptors (1, 10 -15 substrate specificities when assayed in vitro with disaccharide acceptors despite the fact that they share Ͼ90% amino acid sequence homology (10 -13). In addition, some of these enzymes can bind the same acceptor substrates but produce different products. For example, mammalian cells transfected with FucT V can produce cell surface antigens recognized by anti-VIM 2 and anti-difucosyl-sLe x , whereas cells transfected with FucT VI express antigens recognized by antidifucosyl-sLe x but not anti-VIM 2 (11, 13). In a previous study, we demonstrated that truncated forms of FucT III and FucT V, containing ϳ300 amino acids and differing at less than 25 positions, have dramatically different acceptor substrate specificities when assayed with simple disaccharide substrates (16). Furthermore, we found that the swapping of an NH 2 -terminal segment of FucT III, containing eight amino acids u...

The low-Dye strap is used routinely to temporarily control pronation of the foot and, thereby, to diagnose and treat pronatory sequelae. However, the exact biomechanical effects of this strapping technique on the foot are not well documented. The main purpose of this study was to establish the specific mechanical effects of the low-Dye strap on the pronatory foot. Within this context, the specific aim was to assess the effect of the low-Dye strap on three distinct pronation-sensitive mechanical attributes of the foot in the weightbearing state: 1) calcaneal eversion, 2) first metatarsophalangeal joint range of motion, and 3) medial longitudinal arch height. Weightbearing measurements of these three attributes were made before and after application of a low-Dye strap, and statistical comparisons were made. The results of this study indicate that the low-Dye strap is effective in reducing calcaneal eversion, increasing first metatarsophalangeal joint range of motion, and increasing medial longitudinal arch height in the weightbearing state. Knowledge of the exact mechanisms of action of the low-Dye strap will provide practitioners with greater confidence in the use of this modality.

Plantar verrucae in HIV-positive patients may be associated with unusual HPV types and should be analyzed and treated aggressively given the potential for a more distinct clinical manifestation. Additional lesional analysis studies are needed.

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