Fluoroscopically guided neocanalization for treatment of nasolacrimal atresia in two horses.

CASE DESCRIPTION: A yearling Thoroughbred stallion and an 8-year-old Saddlebred mare were evaluated for persistent mucoid ocular discharge. CLINICAL FINDINGS: Examination of both horses revealed copious yellow-tan mucoid ocular discharge with a negative Jones I test, absent nasal punctum, and unsuccessful anterograde nasolacrimal duct (NLD) irrigation. Clinical abnormalities were present on the right side only in one horse and bilaterally in the other. Computed tomography (CT) with contrast confirmed nasolacrimal duct atresia in both horses. TREATMENT AND OUTCOME: Under general anesthesia, the affected NLD was catheterized anterograde and contrast injected. Using fluoroscopic guidance, retrograde access to the distal NLD was obtained for through-and-through wire access. Over the wire, the stoma was dilated and a temporary stent placed for 4-8 weeks. After the procedure, both horses were comfortable and free of ocular discharge at the minimum time of last follow-up, 9 months postoperatively. CLINICAL RELEVANCE: Fluoroscopically guided neocanalization is a viable alternative to traditional surgical approaches for NLD atresia, especially when access to the site of obstruction is limited.

Encrusted Cystitis with Suspected Ureteral Obstruction Following Cystoscopic-Guided Laser Ablation of Ectopic Ureters in a Dog.

A 1 yr old 30 kg spayed female Labrador retriever presented for stranguria and hematuria 3 wk after cystoscopic laser ablation for ectopic ureters. Encrusted cystitis was diagnosed based on ultrasonography, cystoscopy, urinalysis, and culture of Corynebacterium urealyticum from the urine. Unilateral hydronephrosis and hydroureter were suspected to be secondary to obstruction at the trigone. The dog was treated with focal debridement of plaques at the left ureter, urinary acidification, and long-term antibiotic therapy with complete recovery. This is the first report of encrusted cystitis as a complication of cystoscopic-guided laser ablation for ectopic ureters, and suggests cystoscopic debridement may be useful if ureteral obstruction occurs.

Mucopolysaccharidosis type VI in a juvenile miniature schnauzer dog with concurrent hypertriglyceridemia, necrotizing pancreatitis, and diabetic ketoacidosis.

A 7-month-old, neutered male miniature schnauzer dog with a history of cryptorchidism and umbilical hernia was referred for diabetic ketoacidosis. Clinical evaluation revealed stunted growth, skeletal abnormalities, hypertriglyceridemia, diabetic ketoacidosis, and acute necrotizing pancreatitis. Further testing was diagnostic for mucopolysaccharidosis type VI causing the stunted growth and skeletal deformities, but no connection between mucopolysaccharidosis type VI, hypertriglyceridemia, and pancreatic diseases was found.

Mucopolysaccharidose de type VI chez un jeune chien Schnauzer miniature atteint d'hypertriglycéridémie, de pancréatite nécrosante et d'acidocétose diabétique concomitantes. Un chien Schnauzer miniature castré âgé de 7 mois avec une anamnèse de cryptorchidie et d'hernie ombilicale a été référé pour une acidocétose diabétique. L'évaluation clinique a révélé une croissance arrêtée, des anomalies squelettiques, l'hypertriglycéridemie, l'acidocétose diabétique et une pancréatite nécrosante aiguë. Des tests supplémentaires ont permis de diagnostiquer une mucopolysaccharidose de type VI causant une croissance arrêtée et des difformités squelettiques, mais aucun lien avec la mucopolysaccharidose de type VI, l'hypertriglycéridémie et les maladies pancréatiques n'a été trouvé.(Traduit par Isabelle Vallières).

Structural analysis of a novel anionic polysaccharide from Porphyromonas gingivalis strain W50 related to Arg-gingipain glycans.

The Arg-gingipains (RgpsA and B) of Porphyromonas gingivalis are a family of extracellular cysteine proteases and are important virulence determinants of this periodontal bacterium. A monoclonal antibody, MAb1B5, which recognizes an epitope on glycosylated monomeric RgpAs also cross-reacts with a cell-surface polysaccharide of P. gingivalis W50 suggesting that the maturation pathway of the Arg-gingipains may be linked to the biosynthesis of a surface carbohydrate. We report the purification and structural characterization of the cross-reacting anionic polysaccharide (APS), which is distinct from both the lipopolysaccharide and serotype capsule polysaccharide of P. gingivalis W50. The structure of APS was determined by 1D and 2D NMR spectroscopy and methylation analysis, which showed it to be a phosphorylated branched mannan. The backbone is built up of alpha-1,6-linked mannose residues and the side-chains contain alpha-1,2-linked mannose oligosaccharides of different lengths (one to two sugar residues) attached to the backbone via 1,2-linkage. One of the side-chains in the repeating unit contains Manalpha1-2Manalpha1-phosphate linked via phosphorus to a backbone mannose at position 2. De-O-phosphorylation of APS abolished cross-reactivity suggesting that Manalpha1-2Manalpha1-phosphate fragment forms part of the epitope recognized by MAb1B5. This phosphorylated branched mannan represents a novel polysaccharide that is immunologically related to the post-translational additions of Arg-gingipains.

Generation of lys-gingipain protease activity in Porphyromonas gingivalis W50 is independent of Arg-gingipain protease activities.

Porphyromonas gingivalis, a black-pigmenting anaerobe implicated in the aetiology of periodontal disease, contains two loci, rgpA and rgpB, encoding the extracellular Arg-X specific proteases (RGPs, Arg-gingipains), and kgp, which encodes a Lys-X specific protease (KGP, Lys-gingipain). The rgpA and kgp genes encode polyproteins comprising pro-peptide and catalytic domain with large N- and C-terminal extensions which require proteolytic processing at several Arg and Lys residues to generate mature enzymes. The product of rgpB contains only a pro-peptide and the catalytic domain which requires processing at an Arg residue to generate active enzyme. An rgpA rgpB double mutant (E8) of P. gingivalis was constructed to study the role of RGPs in the processing of KGP. A kgp mutant (K1A) was also studied to investigate the role of KGP in the generation of RGPs. E8 was stable in the absence of the antibiotics tetracycline and clindamycin (selection markers for rgpA and rgpB, respectively) and exhibited the same pigmentation, colony morphology and identical growth rates to the parent W50 strain in the absence of antibiotics, in both complex and chemically defined media. The KGP activity of E8, grown in the absence of tetracycline, in whole cultures and in culture supernatants (up to 6 d) was identical to levels in W50. However, in the presence of tetracycline in the growth medium, the level of KGP was reduced to 50% of levels present in whole cultures of W50. Since tetracycline had no effect on RGP or KGP activity when incorporated into assay buffer, this effect is most likely to be on the synthesis of Kgp polypeptide. K1A was also stable in the absence of antibiotics but was unable to pigment, and remained straw-coloured throughout growth. RGP activity in whole cultures of K1A was identical to levels in W50, but RGP activity in 6 d culture supernatants was reduced to 50% of levels present in W50. Thus, although KGP is not required for generation of RGP activity from RgpA and RgpB polypeptides, its absence affects the release/transport of RGP into culture supernatant.

Alteration of a single amino acid residue reverses fosfomycin resistance of recombinant MurA from Mycobacterium tuberculosis.

Mycobacterium tuberculosis has innate resistance to a range of broad-spectrum antimicrobial agents. This may in part reflect the relative impermeability of the mycobacterial cell wall, but additional specific mechanisms may also be important. In the case of fosfomycin, it has been suggested that a key difference in the active site of the M. tuberculosis MurA enzyme might confer resistance. In Escherichia coli, fosfomycin covalently binds to a cysteine normally involved in the enzymic activity, while protein alignments predict an aspartate at this position in the M. tuberculosis MurA. In the present study, it is demonstrated that the wild-type M. tuberculosis MurA is indeed resistant to fosfomycin, and that it becomes sensitive following replacement of the aspartate residue in position 117 by a cysteine. In addition, the study illustrates the use of an inducible expression system in mycobacteria to allow functional characterization of an M. tuberculosis enzyme that is unstable during constitutive expression.