Retrospective Evaluation of Horses Diagnosed with Neuroborreliosis on Postmortem Examination: 16 Cases (2004-2015).

BACKGROUND: Equine neuroborreliosis (NB), Lyme disease, is difficult to diagnose and has limited description in the literature. OBJECTIVE: Provide a detailed description of clinical signs, diagnostic, and pathologic findings of horses with NB. ANIMALS: Sixteen horses with histologically confirmed NB. METHODS: Retrospective review of medical records at the University of Pennsylvania and via an ACVIM listserv query with inclusion criteria requiring possible exposure to Borrelia burgdorferi and histologic findings consistent with previous reports of NB without evidence of other disease. RESULTS: Sixteen horses were identified, 12 of which had additional evidence of NB. Clinical signs were variable including muscle atrophy or weight loss (12), cranial nerve deficits (11), ataxia (10), changes in behavior (9), dysphagia (7), fasciculations (6), neck stiffness (6), episodic respiratory distress (5), uveitis (5), fever (2), joint effusion (2), and cardiac arrhythmias (1). Serologic analysis was positive for B. burgdorferi infection in 6/13 cases tested. CSF abnormalities were present in 8/13 cases tested, including xanthochromia (4/13), increased total protein (5/13; median: 91 mg/dL, range: 25-219 mg/dL), and a neutrophilic (6/13) or lymphocytic (2/13) pleocytosis (median: 25 nucleated cells/µL, range: 0-922 nucleated cells/µL). PCR on CSF for B. burgdorferi was negative in the 7 cases that were tested. CONCLUSION AND CLINICAL IMPORTANCE: Diagnosis of equine NB is challenging due to variable clinical presentation and lack of sensitive and specific diagnostic tests. Negative serology and normal CSF analysis do not exclude the diagnosis of NB.

Primary structure of Chromatium tepidum high-potential iron-sulfur protein in relation to thermal denaturation.

A high-potential ferredoxin (HiPIP) has been purified from the thermophilic purple sulfur bacterium Chromatium tepidum. Most of the properties of this protein, including absorption and electron paramagnetic resonance spectra as well as redox potential, are identical to those of the similar protein isolated from the mesophilic organism Chromatium vinosum. The similarity extends to the amino acid sequences, which share 74 of the 83 residues composing the primary structure of C. tepidum HiPIP. The latter has been determined by sequencing overlapping peptides and precisely measuring the molecular mass of the holoprotein (9136 Da) by electrospray ionization mass spectrometry. The most significant difference between these sequences involves a stretch of 8 amino acids, which is shortened by two residues and notably changed in C. tepidum HiPIP. This region had been identified in the three-dimensional structure of C. vinosum HiPIP as both a link between two strands of a twisted beta sheet coordinating the [4Fe-4S] cluster and an area of strong interaction of the molecule with the solvent. These data have been used to discuss the molecular basis for the slightly improved thermal stability of C. tepidum HiPIP, as compared to C. vinosum HiPIP. Based on the physiological differences distinguishing C. tepidum from other small-sized Chromatiaceae, the presence of an abundant HiPIP in C. tepidum indicates that involvement as electron acceptor for the previously proposed thiosulfate oxidizing activity in C. vinosum may not be the sole function in all purple sulfur bacteria.

Corticotropin-induced secreted protein, an ACTH-induced protein secreted by adrenocortical cells, is structurally related to thrombospondins.

The treatment of primary cultures of bovine adrenocortical cells with nanomolar concentrations of ACTH induces a 10-fold increase in the synthesis of a secreted protein of apparent molecular mass 195 kDa on reducing SDS-polyacrylamide gels. This corticotropin-induced secreted protein (CISP) appears to be an oligomeric calcium-binding protein. Its secretion under serum-free culture conditions is sustained over 4 days in the continuous presence of ACTH. Induction of CISP secretion by ACTH is mimicked by cAMP analogs and adenylate cyclase activators. We report here the purification of CISP to apparent homogeneity with an overall yield of 43% using a combination of heparin-agarose and Mono-Q chromatographies. The NH2-terminal amino acid sequence and the sequence of several tryptic peptides revealed that CISP is structurally related to the members of the thrombospondin (TSP) family. Among these members, bovine CISP appeared to be more homologous to mouse TSP2 (85% identity in the 29 amino acid long NH2-terminal sequence) than to TSP1 (18% identity in the same region). We also observed that CISP binds Ca2+ and is an adhesive protein for bovine adrenocortical cells. Thus, CISP possesses both structural and functional properties of thrombospondins. Whether CISP represents the bovine form of TSP2 or a novel member of the expanding thrombospondin family will need to be elucidated by cloning and sequencing of a larger portion of the molecule.