Low levels of anti-cyclic citrullinated peptide (CCP) 3.1 associated with diseases other than rheumatoid arthritis

Our aim was to investigate the newest generation anti-cyclic citrullinated peptide (CCP) antibody 3.1 assay in diagnosing rheumatoid arthritis (RA) compared with other autoimmune and non-autoimmune diseases. We performed a retrospective observational chart review of patients with a positive CCP level over a one-year period at a single academic institution and assessed the associated diagnoses after at least six-months of follow-up. Of the 281 CCP positive patients during that period, 48% had a diagnosis of RA. The positive predictive value of RA in patients with a high CCP 3.1 assay was 0.619 compared to 0.248 with a low positive CCP 3.1 assay (P < .0001). Overall, there was a lower than expected positive predictive value of CCP 3.1 level with an RA diagnosis, though the likelihood of having an RA diagnosis was higher with a higher CCP level.

Mutations at the arginine residues in α8 loop ofBacillus thuringiensisδ-endotoxin Cry1Ac affect toxicity and binding toManduca sextaandLymantria disparaminopeptidase N

The functional role of the alpha8 loop residues in domain II of Bacillus thuringiensis Cry1Ac toxin was examined. Alanine substitution mutations were introduced in the residues from 275 to 293. Among the mutant toxins, substitutions at R281 and R289 affected toxicity to Manduca sexta and Lymantria dispar. Loss of toxicity by these mutant toxins was well correlated with reductions in binding affinity for brush border membrane vesicles and the purified receptor, aminopeptidase N (APN), from both insects. These data suggest that the two arginine residues in the alpha8 loop region are important in toxicity and APN binding in L. dispar and M. sexta.

Identification of potential compounds promoting BDNF production in nigral dopaminergic neurons: clinical implication in Parkinson's disease

Parkinson's disease (PD) is characterized by the selective loss of dopamine (DA) neurons in the substantia nigral brain region. Currently, there is no cure or treatment that prevents such neuronal loss. Brain-derived neurotrophic factor (BDNF) has been found to support the survival of DA neurons in animal models and in primary cell cultures. However, the large molecular size of BDNF, coupled with the blood brain barrier, prevents its delivery to DA neurons to promote cell survival in the PD brain. The nigral DA neurons have the ability to produce BDNF for neuroprotection via either autocrine or paracrine mechanisms. Low mol. wt compounds were tested to see whether they could increase the production of BDNF in the DA neurons. The compounds tested include neurotransmitters, neuropeptides, intracellular signaling agents, known neuroprotective agents and growth factors. Our results demonstrate that salicyclic acid, cGMP analog, okadaic acid, IBMX, dipyridamole and glutamate significantly enhance BDNF production in DA neuronal cells.