Antibody isotype profiles in serum and circulating antibody-secreting cells following mucosal and peripheral immunisations of sheep.

The isotype-specific antibody responses of sheep immunised with keyhole limpet hemocyanin by a peripheral route (intramuscular (i.m.) injection) were compared to those induced by immunisation via different mucosal routes: (1) intra-nasal spray; (2) rectal deposition with cholera toxin; (3) injection into the mucosa of the small intestine or rectum. Antigen-specific IgG1 antibodies were induced in the i.m., intra-intestinal and intra-rectal injection groups and in a proportion of the cholera toxin immunised sheep, but not in the intra-nasal immunisation group. IgA was the only antibody isotype detected in serum collected from the intra-nasal immunisation group. No significant differences in serum IgA levels were detected in any of the mucosal immunisation groups as compared to the i.m. injection group. In contrast, analysis of the in vitro antibody profiles secreted by circulating antibody-secreting cells (ASC) revealed significantly higher IgA responses in the supernatants from all mucosal immunisation groups. This suggests that the measurement of antibodies secreted by circulating ASCs may be a better correlate of local mucosal responses in ruminants, as has been previously demonstrated in human studies. In addition to IgG1 and IgA responses, immunisation by direct injection of antigen formulations into the intestinal and rectal mucosa were the only groups to induce consistently high IgG2 antibodies in serum and ASC cultures.

The effect of sulfur fertilizer on glucoraphanin levels in broccoli (B. oleracea L. var. italica) at different growth stages.

Three sulfur (S) treatements were imposed by applying gypsum to three broccoli cultivars (Claudia, Marathon, and TB-234) known to differ in glucoraphanin content of mature seeds. The S treatments were control (very low added S), low S (23 kg S ha(-)(1)), and high S (92 kg S ha(-)(1)). The gypsum applications during the early vegetative phase of the three broccoli cultivars increased S uptake and the glucoraphanin content in each plant organ. There were significant genotypic differences for the content of both S and glucoraphanin in all plant organs at different growth stages with gypsum applications. A large increase in S and glucoraphanin content was found in the green heads of broccoli and mature seeds. S present in glucoraphanin accounted for only 4-10% of total S content in broccoli heads. However, S present in glucoraphanin in mature seeds accounted for 40-46% of the total S in the seeds of moderate and high glucoraphanin cultivars (Marathon and TB-234). The partitioning of S into glucoraphanin also increased with gypsum applications. Differences in S uptake, S distribution between organs, and partitioning of S into glucoraphanin largely explained the differences in glucoraphanin content in the green heads and mature seeds for the three broccoli cultivars and three S treatments.

The effect of post-harvest and packaging treatments on glucoraphanin concentration in broccoli (Brassica oleracea var. italica).

The effects of post-harvest and packaging treatments on glucoraphanin (4-methylsulfinylbutyl glucosinolate), the glucosinolate precursor of anticancer isothiocyanate sulforaphane [4-methylsulfinylbutyl isothiocyanate], were examined in broccoli (Brassica oleracea var. italica) during storage times. The results showed that at 20 degrees C, 55% loss of glucoraphanin concentration occurred in broccoli stored in open boxes during the first 3 days of the treatment and 56% loss was found in broccoli stored in plastic bags by day 7. Under both air and controlled atmosphere (CA) storage, glucoraphanin concentration appeared to fluctuate slightly during 25 days of storage and the concentrations under CA was significantly higher than those stored under air treatment. In modified atmosphere packaging (MAP) treatments, glucoraphanin concentration in air control packaging decreased significantly whereas there were no significant changes in glucoraphanin concentration in MAP with no holes at 4 degrees C and two microholes at 20 degrees C for up to 10 days. Decreases in glucoraphanin concentration occurred when the broccoli heads deteriorated. In the present study, the best method for preserving glucoraphanin concentration in broccoli heads after harvest was storage of broccoli in MAP and refrigeration at 4 degrees C. This condition maintained the glucoraphanin concentration for at least 10 days and also maintained the visual quality of the broccoli heads.