Position of maximal nasopharyngeal maximal occlusion in relation to hamuli pterygoidei: use of hamuli pterygoidei as landmarks for palatoplasty in brachycephalic airway obstruction syndrome surgical treatment.

OBJECTIVES: To assess the influence of complete nasopharyngeal occlusion on respiratory signs in brachycephalic dogs. To determine the cranio-caudal position of rostral nasopharyngeal occlusion in relation to the hamuli pterygoidei in brachycephalic dogs. To determine whether using the hamuli pterygoidei as anatomical landmarks for palatoplasty results in clinical respiratory improvement. MATERIALS AND METHODS: Prospective study of dogs diagnosed with brachycephalic obstructive airway syndrome. The dogs were scored according to the severity of their clinical respiratory signs and the nasopharynx was CT scanned. The site of most rostral nasopharyngeal occlusion was measured in relation to the hamuli pterygoidei. Measurements were compared between brachycephalic obstructive airway syndrome group, completely occluded and partially occluded groups. The hamuli pterygoidei were used as the most cranial landmarks for the palatoplasty incision, such that the incision was made at the point of maximal nasopharyngeal occlusion. Owners were interviewed through telephone for the medium-term follow-up. RESULTS: Thirty-five dogs were included. There was no significant association between the severity of respiratory clinical signs and extent of nasopharyngeal occlusion. Maximal nasopharyngeal occlusion was always located directly caudal to the hamuli pterygoidei (mean ±sd value of 9∙4 ±6∙5 mm). hamuli pterygoidei were easily palpable perioperatively in all cases. There was a significant improvement of clinical grades postoperatively. CLINICAL SIGNIFICANCE: The hamuli pterygoidei are a reliable landmark for soft palate incision for palatoplasty in these cases but the distance between them and the site of maximal nasopharyngeal occlusion varied greatly.

Molecular characterization of a novel tobacco pathogenesis-related (PR) protein: a new plant chitinase/lysozyme.

A new PR (pathogenesis-related) protein was isolated from tobacco leaves (Nicotiana tabacum cv. Samsun NN), reacting hypersensitively to tobacco mosaic virus (TMV), by zinc chelate chromatography and was therefore named Pz. Its reactivity toward several lectins indicated the presence of bound sugar residues. From the amino acid sequence of tryptic peptides, Oligonucleotide primers were derived which allowed the synthesis of Pz cDNA by PCR. Using this cDNA as probe, near full-length clones were isolated from a library made from poly(A)+ RNA purified from TMV-infected leaves. Sequence analysis revealed similarities with chitinases/lysozymes of various origins and the purified protein was, indeed, shown to hydrolyse different N-acetylglucosamine-containing substrates. Comparison of peptide and cDNA sequences indicated that Pz protein is synthesized as a pre-pro-protein, a seven-amino acid C-terminal peptide probably being involved in the vacuolar targeting of the protein. Pz mRNA and protein were demonstrated to accumulate strongly in TMV-infected tobacco leaves. Pz transcripts were also found in various tissues of healthy plants, indicating that Pz gene expression is developmentally regulated.