Chitin (β-1,4-linked-N-acetylglucosamine) provides structural integrity to the nematode eggshell and pharyngeal lining. Chitin is synthesized in nematodes, but not in plants and vertebrates, which are often hosts to parasitic roundworms; hence, the chitin metabolism pathway is considered a potential target for selective interventions. Polysaccharide deacetylases (PDAs), including those that convert chitin to chitosan, have been previously demonstrated in protists, fungi and insects. We show that genes encoding PDAs are distributed throughout the phylum Nematoda, with the two paralogs F48E3.8 and C54G7.3 found in C. elegans. We confirm that the genes are somatically expressed and show that RNAi knockdown of these genes retards C. elegans development. Additionally, we show that proteins from the nematode deacetylate chitin in vitro, we quantify the substrate available in vivo as targets of these enzymes, and we show that Eosin Y (which specifically stains chitosan in fungal cells walls) stains the C. elegans pharynx. Our results suggest that one function of PDAs in nematodes may be deacetylation of the chitinous pharyngeal lining.

Objective To determine the influence of needle gauge, syringe volume, and syringe size on needle tract leakage after injection in porcine jejunum. Study design Ex vivo experiment. Sample population Three hundred sixty jejunal segments from 20 feedlot pigs. Methods Fresh porcine intestines were divided into 5‐cm or 10‐cm segments and randomly assigned to the one of nine treatment groups: 25‐gauge, 22‐gauge, and 20‐gauge needles attached to full 12‐mL, half‐full 20‐mL, and full 20‐mL syringes (n = 20/group). The jejunal segments were occluded with Rochester‐Carmalt forceps prior to injection of diluted India ink. Injection time and leakage were noted by a blinded observer. Multivariate analysis was used with segment size, needle gauge, volume infused, time to inject per milliliter, and syringe size as variables. Results Leakage occurred in 36% of 5‐cm and 15% of 10‐cm segments and was immediate without palpation in 33.8% and 11% of segments, respectively. Protective effects were seen for 22‐gauge needles in both 5‐cm (P = .002) and 10‐cm (P = .001) segments, whereas injection of 20 mL had a higher odds ratio of leakage compared with injection of 10 mL and 12 mL in 5‐cm segments (P = .003). Conclusion Injections with 22‐gauge needles reduced the frequency of leakage, while 20 mL instilled in 5‐cm segments increased the frequency of leakage in intact segments of porcine jejunum. Clinical significance Injection with a smaller syringe size attached to a 22‐gauge needle through a 10‐cm segment of small intestine may lower the frequency of leakage from the injection site, but influence on the detection of surgical site leakage remains unknown.

A 2-year-old female spayed Great Dane presented for inappetence and lethargy. Abdominal radiographs revealed a severely gas-distended segment of colon. Computed tomography was performed and characterized a 180 • anticlockwise colonic torsion with entrapment in a mesenteric/omental rent without vascular compromise. Exploratory laparotomy confirmed entrapment, but not colonic torsion. Computed tomography provided important information to assist clinical management decisions for this dog with colonic entrapment.

Objective The objective of this study was to determine the frequency of positive cultures of the surgical gown cuffs among scrubbed personnel prior to and immediately after orthopaedic surgical procedures performed on client-owned dogs. Study Design In this cross-sectional study, the left and right surgical gown cuffs of three scrubbed persons in 10 orthopaedic surgical procedures were individually sampled using a sterile wipe prior to and immediately after surgery in order to determine the frequency of and risk factors associated with positive bacterial cultures. Results Fifty of 120 (41.6%) cultures were positive with an even distribution before and after surgery. The three most common genera were Staphylococcus, Corynebacterium and Streptococcus. Using multivariable logistic regression models, humidity in the operating room (odds ratio: 1.04, 95% confidence interval: 1.00–1.08; p = 0.038) and the number of individuals scrubbed into surgery (odds ratio: 0.59, 95% confidence interval: 0.39–0.91; p = 0.016) had a significant effect on the likelihood of positive culture after surgery. Of the nine patients available for follow-up, one dog developed osteomyelitis. Conclusions Maintaining the humidity in the operating room to the lowest comfortable level may reduce contamination of the surgical gown cuffs. Confirmation of bacterial contamination of surgical gown cuffs warrants adherence to operative guidelines to minimize the risk of surgical gown cuffs' contact with sterile attire, equipment and the surgical field during surgical procedures.

Retained surgical sponges or gauzes (RSS) are an uncommon complication of exploratory laparotomy surgery and pose a clinically significant risk to the patient. The purpose of this two‐part, prospective, descriptive study was to describe the previously uncharacterized ultrasonographic appearance of RSS in phantom and cadaveric models of the acute postoperative period (24–48 h). For the first part of the study, a gelatin phantom containing a woven gauze with a radiopaque marker (radiopaque gauze), a woven gauze with no marker (nonradiopaque gauze), and a laparotomy sponge with a radiopaque marker (radiopaque sponge) was evaluated with ultrasonography. For the second part of the study, a total of 23 gauzes and sponges (of the aforementioned three types) were placed within the peritoneal cavity of 20 cadavers in one of three randomized locations during an exploratory laparotomy laboratory. The cadavers were imaged with ultrasonography 17 h later and still images and video clips were reviewed. The retained surgical sponges and gauzes in the gelatin phantom displayed multiple hyperechoic layers and variable degrees of distal acoustic shadowing. In cadavers, 100% (23/23) of the retained surgical sponges and gauzes displayed a single hyperechoic layer of variable thickness and distal acoustic shadowing. In 95.6% (22/23) retained sponges and gauzes, there was a thin hypoechoic layer noted superficially to the hyperechoic layer. An improved understanding of the ultrasonographic appearance of retained sponges or gauzes in the acute postoperative period may assist in the identification of these objects.

To assess the accuracy of a proportion-corrected radiographic cementless femoral stem level calculation in a cadaver model. Study design: Cadaveric study.Sample population: Twelve cadaveric canine femurs.Methods: Cementless femoral stems were implanted in 12 cadaver femurs at three stem levels. Craniocaudal projection radiographs of the implanted femurs were obtained at 0 , 10 , 20 , 30 , and 45 angulations in the sagittal plane (relative to the radiographic plate) and at 0 , 15 , and 30 internal and external axial rotation. A proportional calculation including actual stem length, radiographically measured stem length, and radiographically measured stem level relative to the greater trochanter (uncorrected stem level) was solved to yield a corrected stem level. The errors of the stem level measurements were compared.Results: With 0 or 15 of internal rotation, the true stem level differed by more than 0.5 mm from corrected stem level in 2 of 30 tested femoral positions. It differed from the uncorrected stem level in 10 of 30 positions. With 15 and 30 external rotation or 30 internal rotation, the corrected stem level was not more accurate than the uncorrected stem level for any femoral position. Conclusion: Use of a proportion correction minimized variability in the stemlevel measurements due to sagittal angulation (up to 30 ) of the femur at 0 or 15 of internal rotation.Clinical significance: A proportion correction can improve the accuracy of femoral stem-level assessment on craniocaudal projection radiographs, which may aid in the detection of subsidence after cementless total hip replacement. | INTRODUCTIONCementless total hip replacement (THR) is a common surgical treatment for diseases of the coxofemoral joint in dogs. 1 Press-fit THR systems rely on osseointegration for long-term stability; however, the initial stability of the Abbreviations: RM, repeated measures; THR, total hip replacement.The results of this study were reported in part at the 44th annual