Effect of whole-milk allowance on liveweight gain and growth of parenchyma and fat pads in the mammary glands of dairy heifers at weaning.

The rates of development of 2 tissues in mammary glands, parenchyma (PAR) and the mammary fat pad (MFP), in response to nutrition in early life might have a major bearing on lifetime milk production. Historical studies reported that feeding greater amounts of dietary nutrients from postweaning to puberty increased growth rates of heifers and stimulated the growth of MFP at the expense of PAR, which might suggest compromised mammary development and future milk production. The current study sought to determine if a higher volume of whole milk (8 vs. 4 L/d) offered to calves would increase rates of growth and development of PAR in mammary glands at weaning (1 to 12 wk). To measure these tissues, we developed 2 simple methods to assess the size of PAR and MFP at the time of screening using ultrasound. We report that calves offered 8 L/d of whole milk had greater rates of growth until weaning (0.86 ± 0.06 vs. 0.81 ± 0.09 kg/d), compared with calves offered 4 L/d. Ultrasonography showed that despite the faster rates of growth in calves offered 8 L/d of milk/d, the ratio of PAR:MFP depth was 40% less at weaning in the front glands (34%) compared with calves offered 4 L of milk/d. Rear glands were less impaired. The ultrasound methods developed here might be useful to monitor the development of mammary glands in response to different nutritional regimens during the preweaning period.

An oral vaccine against NMDAR1 with efficacy in experimental stroke and epilepsy.

The brain is generally considered immunoprivileged, although increasing examples of immunological responses to brain antigens, neuronal expression of major histocompatibility class I genes, and neurological autoimmunity have been recognized. An adeno-associated virus (AAV) vaccine generated autoantibodies that targeted a specific brain protein, the NR1 subunit of the N-methyl-D-aspartate (NMDA) receptor. After peroral administration of the AAV vaccine, transgene expression persisted for at least 5 months and was associated with a robust humoral response in the absence of a significant cell-mediated response. This single-dose vaccine was associated with strong anti-epileptic and neuroprotective activity in rats for both a kainate-induced seizure model and also a middle cerebral artery occlusion stroke model at 1 to 5 months following vaccination. Thus, a vaccination strategy targeting brain proteins is feasible and may have therapeutic potential for neurological disorders.

Isolation, characterisation and cell growth-regulatory properties of kumara (sweet potato) trypsin inhibitors.

Locally grown kumara (sweet potato; Ipomea batatis) was used as the starting point for the purification of a proteinase inhibitor. The purified inhibitor was highly specific for trypsin, and much less effective as an inhibitor of chymotrypsin. Two 22kDa variants were present, closely homologous to each other and to sporamin A, but with a single amino acid substitution (proline in place of serine, the second residue in mature sporamin A). One variant had the same N-terminus as sporamin A, whereas the other had a tripeptide N-terminal extension, which may represent an intermediate in the proteolytic processing of the precursor protein. A larger variant was apparently a disulphide-linked dimer of the monomeric inhibitor. A rabbit polyclonal antiserum prepared against the trypsin inhibitor reacted with all of these variants, but did not cross-react with commercially-available soybean proteinase inhibitors. The purified inhibitor did resemble other proteinase inhibitors in having a biphasic effect upon the proliferation of human fibroblasts, with a mitogenic action at low concentrations, and an inhibitory effect at higher concentrations.