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Biomedical subjects

J D Fox

Publications and source records attributed to J D Fox.

43 records · Page 3Linked to original sources
PubMed1981

Effect of dietary iodine on tissue iodine content in the bovine.

Twelve yearling Holstein steers were blocked by weight and assigned to receive one of three dietary I levels (0, 50 or 400 mg ethylenediamine dihydriodide [EDDI]/head/day) for 4 weeks. Average daily gain, body temperature and respiration rate were measured before and during the I feeding period, and no significant differences among treatment groups were found. Serum total I showed a significant increase with each increment of I. When animals were slaughtered, five muscle samples and liver and thyroid samples were dissected for I analysis. Mean total muscle I levels for the 0-, 50- and 400-mg treatment groups were .092, .127 and .406 micrograms/g wet tissue, respectively, each being different (P less than .05) from the other two. I concentrations did not differ statistically between individual muscles within the 0- and 50-mg treatment groups, but in the 400-mg EDDI group, the trapezius (.469 micrograms/g) and biceps brachii (.569 micrograms/g) muscles had higher (P less than .05) I concentrations than the semimembranous (.316 micrograms/g), psoas major (.365 micrograms/g) and longissimus (.307 micrograms/g). Dietary I increased (P less than .05) liver and thyroid I concentrations in the 400-mg treatment group over those observed for the 0- and 50-mg treatment groups.

Animal Feed↗
PubMedDate not supplied

Comparison of three immunoassays for the detection of anti-HHV6.

Sera from 96 blood donors were tested for antibody to human herpesvirus 6 by indirect immunofluorescence (IF), circle immunoassay (CIA) and competitive radioimmunoassay (RIA). The correlation between the three assays was good but the CIA and competitive RIA were more sensitive for the detection of HHV6 antibody than indirect IF. The crossreaction of HHV6 antibody with that to the other human herpesviruses was also studied in this blood donor group. No correlation was found between antibody to human herpesvirus 6 by any of the methods described and antibody to any of the other human herpesviruses in these sera.

Antibodies, Viral↗
PubMedDate not supplied

Conjugates of cis-4-hydroxy-L-proline and poly(PEG-Lys), a water soluble poly(ether urethane): synthesis and evaluation of antifibrotic effects in vitro and in vivo.

Synthetic approaches for the preparation of macromolecular conjugates of the antifibrotic agent cis-4-hydroxy-L-proline (cHyp) were explored, and the efficacy of the conjugates in inhibiting collagen accumulation was investigated in vitro and in vivo. In one approach, poly(PEG-Lys), an alternating copolymer of poly(ethylene glycol) (PEG) and lysine, was used as the carrier. To prepare pendent chain systems, cHyp was attached to poly(PEG-Lys) through an amide linkage [poly(PEG-Lys-cHyp amide)] or through an ester linkage [poly(PEG-Lys-cHyp ester)]. In an alternative approach, cHyp was incorporated into the backbone of a linear copolymer consisting of PEG, succinic acid, and cHyp units [poly(PEG-succinate-cHyp)]. Bioactivity in vitro was assessed by the ability of the cHyp conjugates to inhibit growth of cultured smooth muscle cells (SMC) and rat lung fibroblasts (RLF). Cell numbers were compared to control experiments in the presence of biologically inactive trans-4-hydroxy-L-proline (tHyp). After a 5 day period, the presence of 8 micrograms/mL of cHyp delivered by poly(PEG-Lys-cHyp amide) resulted in a 47% reduction in the number of SMC (p < 0.05), the presence of 36 micrograms/mL of cHyp delivered by poly(PEG-Lys-cHyp ester) resulted in a 38% reduction in the number of SMC (p < 0.05), while the presence of 118 micrograms/mL of cHyp delivered by poly(PEG-succinate-cHyp) resulted in a 31% reduction in the number of cells (p < 0.05). An identical trend was observed for the inhibition of RLF growth. In general, poly(PEG-Lys-cHyp amide) was most active, followed by poly(PEG-Lys-cHyp ester) and the backbone system, poly(PEG-succinate-cHyp). Specifically, poly(PEG-Lys-cHyp amide) was over 100-fold more active in inhibiting cell growth than free cHyp. Bioactivity in vivo was evaluated by measuring collagen accumulation in subcutaneously implanted poly(vinyl alcohol) sponges in rats. Among the tested conjugates, poly(PEG-Lys-cHyp amide) was most active, reducing collagen accumulation in the sponge by 33% after 14 days relative to controls (p < 0.05). This result indicates that the covalent attachment of cHyp to poly(PEG-Lys) carries may be a useful strategy for the local inhibition of collagen accumulation in tissues.

Animals↗