Systemic Edwardsiella tarda infection in a Western African lungfish (Protopterus annectens) with cytologic observation of heterophil projections

This report describes a case of systemic bacterial infection caused by Edwardsiella tarda in a Western African lungfish (Protopterus annectens) exposed to poor environmental and husbandry conditions. The fish presented with a large, external ulcerative lesion and died 2 weeks after developing anorexia. Histological evaluation revealed multifocal areas of necrosis and heterophilic and histiocytic inflammation throughout multiple tissues. Gram stain identified small numbers of intra‐ and extracellular monomorphic Gram‐negative 1 to 2 μm rod‐shaped bacilli. Cytology of lung granuloma, kidney and testes imprints identified heterophilic inflammation with phagocytosis of small monomorphic bacilli and some heterophils exhibiting cytoplasmic projections indicative of heterophil extracellular traps (HETs). Initial phenotypic analysis of isolates from coelomic fluid cultures identified E. tarda. Subsequent molecular analysis of spleen, liver and intestine DNA using an E. tarda‐specific endpoint PCR assay targeting the bacterial fimbrial subunit yielded a 115 bp band. Sequencing and BLASTN search revealed the sequence was identical (76/76) to E. tarda strain FL95‐01 (GenBank acc. CP011359 ) and displayed 93% sequence identity (66/71) to Edwardsiella hoshinae strain ATCC 35051 (GenBank acc. CP011359 ). This is the first report of systemic edwardsiellosis in a lungfish with concurrent cytologically identified structures suggestive of HETs.     

Ants (Azteca sp.) as potential biological control agents in shade coffee production in Chiapas, Mexico

The role of Azteca sp. ants as potential biological control agents was studied in an organic coffee farm in Chiapas, Mexico. Individual larvae of Pieris rapae were placed on trees with artificially enhanced ant activity and both time to disappearance of the larvae and ant activity were recorded. There was a general negative relationship between time to disappearance and ant activity. A census of spiders was made of coffee bushes with and without foraging Azteca, encountering a negative relationship between ants and spiders. These results indicate that Azteca ants have potential as pests through their positive effect on scale insects, but also have potential as biological control agents, through their negative effect on potential herbivores. Furthermore, the correlation between ant and spider densities suggests a complicated relationship between these two predatory organisms, implying a more complicated food web structure than simply ants, homoptera and other herbivores.This revised version was published online in November 2005 with corrections to the Cover Date.     

Regulation of Insulin Action by Diet and Exercise

The regulation of the cellular actions of the hormone insulin is essential to the maintenance of macronutrient metabolism, body weight regulation, and a surprisingly diverse range of other integrative physiologic functions. Because of the diverse targets of insulin action, any dysfunction in insulin is likely to have systemic consequences. Although type 1 and type 2 diabetes are the most obvious clinical consequences of impaired insulin synthesis and insulin action, respectively, there are also subclinical disorders that attend defects in the function of insulin. In humans and horses, the “metabolic syndrome” is characterized by a cluster of metabolic sequelae that arise as a result of insulin resistance. Importantly, both diet and exercise can regulate insulin action and can thus be leveraged as treatment tools to prevent and treat the metabolic syndrome. The aim of this review is to characterize the integrative biology of insulin action and to describe the role of diet and exercise in regulating tissue responsiveness to insulin.     

Premature parturition,edema, and ascites in an alpaca infected with Anaplasma phagocytophilum

An 8-year-old alpaca was presented for fever, anorexia, edema, ascites, and premature parturition. She was determined to have Anaplasma phagocytophilum infection based on positive blood polymerase chain reaction (PCR) and positive acute and convalescent serum titers. Antibiotics and supportive therapies were administered and the alpaca made a complete recovery.     

Expression of bone morphogenetic protein-6 and -2 and a bone morphogenetic protein antagonist in horses with naturally acquired osteochondrosis

OBJECTIVE: To determine the mRNA expression of bone morphogenetic protein (BMP)-6 and -2 and a BMP antagonist (Noggin) in horses with osteochondrosis. SAMPLE POPULATION: Samples of articular cartilage from affected stifle or shoulder joints of 10 immature horses with naturally acquired osteochondrosis and corresponding joints of 9 clinically normal horses of similar age; additionally, samples of distal femoral growth plate cartilage and distal femoral articular cartilage were obtained from a normal equine fetus. PROCEDURE: Cartilage specimens were snap-frozen in liquid nitrogen, and total RNA was isolated. Adjacent specimens were fixed in 4% paraformaldehyde for histologic examination. Expression of BMP-6, BMP-2, and Noggin mRNA was evaluated by real-time quantitative polymerase chain reaction (PCR) assays. Spatial tissue mRNA expression of BMP-6 was determined by in situ hybridization. RESULTS: Nucleotide sequences were obtained for portions of the BMP-6 propeptide and mature peptide region, as well as the signal and mature peptide region of Noggin. Expression of BMP-6, BMP-2, and Noggin mRNA was found to be similar in cartilage from normal and osteochondrosis-affected horses. Spatial expression of BMP-6 correlated with the middle and deep layers of articular cartilage; no differences were observed in overall expression between cartilage specimens from the 2 groups of horses. No expression of BMP-6 was found in the superficial layer, subchondral bone, or osteochondrosis-affected cleft fibrous tissue. CONCLUSIONS AND CLINICAL RELEVANCE: Although these signaling peptides may play important roles in cartilage differentiation, results did not provide evidence to suggest that they are involved in the disease process of osteochondrosis.     

Detection of anti-lens crystallin antibody in dogs with and without cataracts

Objective To determine if antilens crystallin (ALC) serum and aqueous humor antibodies were present in normal dogs and dogs with cataracts, whether antibody incidence varied with stage of cataract, and whether antibody titer had a relationship to the presence of lens‐induced uveitis. Methods Serum and aqueous humor samples were obtained from normal dogs and dogs with cataracts. Lens crystallin was separated by SDS‐polyacrylamide gel electrophoresis (SDS‐PAGE), and antilens crystallin antibodies were detected by Western immunoblot analysis. An indirect ELISA using crystallin protein as antigen was also used to detect antilens crystallin antibodies in serum and aqueous humor. Test groups included normal, incipient, immature, mature, hypermature and diabetic cataract. Results SDS‐PAGE identified bands with molecular weights of lens crystallin subunits. Western immunoblotting demonstrated reaction between canine serum and these protein bands. The five canine serum samples that reacted with crystallin subunits on Western blots had corresponding reactivity on the ELISA. All aqueous humor samples (30) were negative. Serum ALC antibodies were detected in 59.3% (16/27) of controls, 66.7% (16/24) of incipients, 50.0% (10/20) of immatures, 37.9% (11/29) of matures, 28.6% (6/21) of hypermatures, and 26.7% (4/15) of diabetics. Serum ALC antibodies were detected in 43.1% (47/109) of all cataract samples. There was a statistically significant negative association between the presence (P = 0.004) and maturity (P = 0.004) of cataract and presence of ALC serum antibodies. In the immature and hypermature cataract groups, there was a statistically significant negative association between ALC serum antibody titer and severity of uveitis (95% confidence interval). Conclusions There is a negative association between the presence (P = 0.004) and maturity (P = 0.004) of cataract and presence of ALC serum antibodies.     

Presence of opioid growth factor and its receptor in the normal dog,cat and horse cornea

Objective To determine if opioid growth factor (OGF, [Met⁵]enkephalin) and its specific receptor (OGFr) are present in normal cat, dog and horse cornea. Animals studied Normal dog, cat and horse. Procedure Corneas were obtained from animals euthanized for reasons unrelated to this project. One cornea from each of three normal cats, dogs and horses was evaluated. The right or left cornea from each animal was chosen randomly. Corneas were harvested and placed in corneal storage media for transport to The M.S. Hershey Medical Center of The Pennsylvania State University where immunocytochemistry techniques were used to demonstrate the presence and location of OGF and OGFr. Tissues were rinsed in Sorenson's phosphate buffer, immersed in 20% sucrose in buffer and then snap frozen in isopentane. Corneas were then embedded in OCT medium and 15 µm cryostat sections were created. Presence of OGF was determined by using a polyclonal antibody to [Met⁵]enkephalin and assessing immunoreactivity. OGFr presence was determined by using a previously characterized rabbit polyclonal antibody to the receptor. Results OGF and OGFr were identified in large quantities in the corneal epithelium of all three species. Conclusion Opioid growth factor and its specific receptor are present in the corneal epithelium of normal cats, dogs and horses. OGF is present in the cornea of many species and its presence is theorized to inhibit healing of injured tissue.