Biomedical subjects

W D Woodward

Publications and source records attributed to W D Woodward.

13 recordsLinked to original sources

PubMed1998

1,25-dihydroxyvitamin D3 is a positive regulator for the two anti-encephalitogenic cytokines TGF-beta 1 and IL-4.

Previously we demonstrated that 1,25-dihydroxyvitamin D3 blocks the progression of relapsing encephalomyelitis. We now propose that 1,25-dihydroxyvitamin D3 blocks these autoimmune symptoms by stimulating the differentiation and/or function of cells that inhibit the encephalitogenic process. To support this belief, we have found that 1,25-dihydroxyvitamin D3 administration to mice increases IL-4 transcripts by 3- to 25-fold and TGF-beta 1 transcripts by 4- to 24-fold. Similarly, IL-4 and TGF-beta 1 transcripts were higher in the central nervous system of 1,25-dihydroxyvitamin D3-treated mice compared with controls. The number of cells recoverable from the lymph nodes of 1,25-dihydroxyvitamin D3-treated mice was only 50% that of controls. Overall, 1,25-dihydroxyvitamin D3 treatment causes a net loss in the total number of lymphocytes while the number of IL-4 and TGF-beta 1 transcripts increased. The systemic and local increase in the expression of these two anti-inflammatory cytokines by 1,25-dihydroxyvitamin D3 may be responsible for the ability of this drug to block encephalomyelitis.

Adjuvants, Immunologic↗

PubMed1988

Teat skin normal flora and colonization with mastitis pathogen inhibitors.

Isolates of bacteria from normal teats were used to attempt colonization of teats of dry cows or neonatal calves. Isolates for inoculation were chosen on the basis of ability to inhibit mastitis pathogens in vitro, with the ultimate goal of in vivo inhibition of mastitis pathogens at the teat surface. Three bacterial normal flora isolates (Corynebacterium xerosis, Bacillus sp. and Aerococcus viridans) persisted less than 10 days on the teats of dry cows. The fourth isolate, Staphylococcus hominis 1, was studied in greatest detail because studies characterizing the normal teat flora showed staphylococci to be the predominant flora. The S. hominis 1 isolated used for inoculation was an inhibitor of Gram-positive mastitis pathogens. It was a biotype not found on these teats prior to inoculation, thus facilitating identification of the inoculated isolate on sequential sampling. Colonization of newborn calves, before other bacterial flora became established, resulted in recovery of inoculated S. hominis 1 for an average of 51 days or longer. On dry cow teats it was detected for up to 28 days. On several occasions the inoculated S. hominis 1 was found in pure culture. Since many new infections occur during the dry period, the colonization of dry cow teats with S. hominis 1 organisms inhibitory for Gram-positive pathogens should be tested as an adjunct to other methods of mastitis prevention.

Animals↗

PubMed1987

In vitro growth inhibition of mastitis pathogens by bovine teat skin normal flora.

One factor contributing to differences in the susceptibility of cows to mastitis may be differences in the teat skin normal flora, which could inhibit or enhance the growth of pathogenic bacteria. Using in vitro cross-streaking methods, we found that 25% of the isolates of teat normal flora of non-lactating heifers inhibited the growth of selected mastitis pathogens, but enhancers were not detected. Gram-positive pathogens were inhibited to a greater extent than Gram-negative pathogens. Inhibition was not a characteristic of specific genera or species of normal flora, but rather a property of certain variants within a species. This phenomenon of inhibition of mastitis pathogens in vitro by normal flora may be useful as an in vivo biological control method to reduce the incidence of mastitis.

Acinetobacter↗

PubMed1984

Decline in serum zinc level throughout adult life in the laboratory mouse.

The objective of the study was to test the hypothesis that age and serum zinc level exhibit a negative correlation in the adult mouse. Fifty-seven male CBA/J mice were fed ad libitum, for 14 days, a semisynthetic diet containing 8 micrograms zinc per gram, a level that meets but does not exceed the weanling growth requirement for this nutrient under our conditions. At the end of the feeding trial the mice ranged in age from 7 to 87 weeks. Regression analysis indicated a linear decrease in serum zinc level with advancing age throughout adult life (Y = 0.70 - 0.0029 X, where Y is zinc level in micrograms/ml and X is age in weeks). The relationship was not changed significantly when adjusted for the effects of serum protein concentration, initial live weight, or 14-day weight gain and feed intake. The results suggest that the dietary zinc requirement increases progressively as an age-related phenomenon.

Aging↗

PubMed1983

Reduced fecundity of vitamin D deficient rats.

1. Female rats fed on a vitamin D deplete (D-) diet for 90 days prior to mating gave birth to litters having significantly fewer young than females fed a diet containing vitamin D (2.2 IU/g, D + diet). 2. Neither age nor body weight of females had a significant influence on litter size. 3. Serum calcium and phosphorus levels in D+ and D- dams were not significantly different, nor were serum calcium and phosphorus levels and bone ash of D+ and D- weanlings. 4. The level of 25-hydroxyvitamin D3 [25(OH)D3], the main circulating form of vitamin D, was low in D- dams and was not detected in D- weanlings. 5. These data suggest that vitamin D is required for reproduction in the rat.

Animals↗

PubMed1976