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In the present study, we characterize a polymorphism in the CD93 molecule, originally identified as the receptor for the C1q complement component (i.e., C1qRp, or AA4.1) in non-obese diabetic (NOD) mice. This allele carries a coding polymorphism in the first epidermal growth factor-like domain of CD93, which results in an amino acid substitution from Asn-->His at position 264. This polymorphism does not appear to influence protein translation or ecto-domain cleavage, as CD93 is detectable in bone-marrow-derived macrophage and B-cell precursor lysates and in soluble form in the serum. The NOD CD93 isoform causes a phenotypic aberrancy in the early B-cell developmental stages (i.e., pro-, pre-, immature, and transitional), likely related to a conformational variation. Interestingly, the NZB/W F1 strain, which serves as a murine model of Lupus, also expresses an identical CD93 sequence polymorphism. Cd93 is located within the NOD Idd13 locus and is also tightly linked to the NZB/W F1 Wbw1 and Nkt2 disease susceptibility loci, which are thought to regulate natural killer T (NKT) cell homeostasis. Consistent with this genetic linkage, we found B6 CD93(-/-) and B6.NOD(Idd13) mice to be susceptible to a profound CD4(+) NKT cell deficient state. These data suggest that Cd93 may be an autoimmune susceptibility gene residing within the Idd13 locus, which plays a role in regulating absolute numbers of CD4(+) NKT cells.

Dietary copper sulfate (CuSO4) and tribasic copper chloride (TBCC) were examined for their effects on intestinal physiology and growth of broiler chickens. In 2 experiments (Experiments 1 and 2), day-old broiler chicks were fed 1 of 4 diets: a basal diet with no supplemental copper (Cu; negative control), a basal diet + 188 mg of Cu/kg of diet from TBCC or CuSO4, or a basal diet + subtherapeutic antibiotics (bacitracin and roxarsone; positive control). In Experiment 1 (recycled litter), CuSO4 and TBCC increased carcass weight (d 45 posthatch) compared with the negative control (P < 0.05 for each). In Experiment 2 (fresh litter), negative control and TBCC increased carcass weight (d 42 posthatch) compared with the positive control (P < 0.05 for each). At d 30 to 31 posthatch, intestinal histology was measured. In Experiment 1 (recycled litter), dietary TBCC, CuSO4, and positive control decreased the number of lamina propia lymphocytes or intraepithelial lymphocytes (IEL), or both, compared with the negative control (P < 0.05). However, in Experiment 2 (fresh litter), TBCC and positive control increased the number of duodenum IEL compared with the negative control (P < 0.05), and negative control and TBCC increased the number of ileum IEL. These data demonstrate that broiler performance and intestinal physiology can be influenced by dietary Cu source and level as well as microbial environment (fresh vs. recycled litter).

A reversed-phase high performance liquid chromatographic method is described for the simultaneous determination of vitamins D3, E and K1 and retinyl palmitate in plasma. Narrow-bore columns are recommended because this alternative provides a good separation efficiency, plus greater economy and sensitivity. Detection limits for individual vitamins range from 0.42 to 2.8 ng. All vitamins were separated in less than 9 min. Recovery studies showed good results for all solutes (88.8-100.3%) and the intra-day coefficients of variations ranged from 1.0 to 4.5%. This method permits the simple determination of fat-soluble vitamins using 1 ml of cattle heparinized plasma.