Q Fever (Coxiella burnetii) Knowledge and Attitudes of Australian Cat Breeders and Their Husbandry Practices.

A Q fever outbreak in a small animal veterinary hospital, associated with a cat caesarean section, initiated a cat seroprevalence study (n = 712) that found circulating antibodies to Coxiella burnetii was highest in cattery-confined breeding cats (9.3%). These findings stimulated interest about potential sources of C. burnetii infection for cats and humans associated with cats. Cat breeders are potentially a group at increased risk of C. burnetii infection, and this study sought to identify potential risk factors. A cross-sectional online survey was conducted targeting all domestic cat breeders registered with an affiliate member body in Australia in 2015. Responses from 177 cat breeders across Australia were analysed. Forty per cent of responding cat breeders had not heard of Q fever. Raw meat was fed as an integral constituent of the diet by 89% of respondents. Eighty per cent of respondents allowed queens access to the home for parturition, and assistance of queens and resuscitation of kittens at the time of birth were reported by 97% of respondents. Respondents who perceived some level of exposure to Q fever through their breeding activities were three times less likely to perform mouth-to-snout resuscitation (OR 0.3 95% CI 0.1-0.9; P = 0.034) than those who did not perceive a risk of exposure. Similarly, respondents who perceived Q fever as a risk through breeding activities were close to eight times more likely to use personal protective equipment during parturition (OR 7.7 95% CI 1.5-39.9; P = 0.015) than those who did not. Husbandry practices of cat breeders that may increase the risk of C. burnetii transmission require further targeted investigations to assess the contribution of these risk factors to the acquisition of disease. Concurrent education forums are recommended to inform Australian cat breeders of the aetiopathogenesis of Q fever.

Seroprevalence of Coxiella burnetii in Australian dogs.

The role of dogs in the transmission of Coxiella burnetii to humans is uncertain, and extensive seroprevalence studies of dogs have not been previously conducted in Australia. This study determined C. burnetii exposure in four diverse canine subpopulations by adapting, verifying and comparing an indirect immunofluoresence assay (IFA) and an enzyme-linked immunosorbent assay (ELISA) used to detect anti-C. burnetii antibodies in humans. Canine serum samples (n = 1223) were tested with IFA from four subpopulations [breeding establishments; household pets; free-roaming dogs in Aboriginal communities; shelter dogs]. The proportions of seropositive dogs were as follows: breeding (7/309, 2.3%), household pets (10/328, 3%), Aboriginal communities (21/321, 6.5%) and shelters (5/265, 1.9%). Dogs from Aboriginal communities were 2.8 times (CI 1.5-5.1; P < 0.001) more likely to be seropositive than dogs from other populations. The ELISA was used on 86 of 1223 sera tested with IFA, and a Cohen's Kappa coefficient of 0.60 (CI 0.43-0.78) indicated good agreement between the two assays. This study has established that Australian dogs within all four subpopulations have been exposed to C. burnetii and that a higher seroprevalence was observed amongst free-roaming dogs associated with Aboriginal communities. As C. burnetii recrudesces during pregnancy and birth products contain the highest concentration of organism, individuals assisting at the time of parturition, those handling pups shortly after birth as well as those residing in the vicinity of whelping dogs are potentially at risk of developing Q fever. However, the identification of active antigen shed in excreta from seropositive dogs is required in order to accurately define and quantify the public health risk.

Asymmetric domain nucleation and unusual magnetization reversal in ultrathin Co films with perpendicular anisotropy.

We report unexpected phenomena during magnetization reversal in ultrathin Co films and Co/Pt multilayers with perpendicular anisotropy. Using magneto-optical Kerr microscopy and magnetic force microscopy we have observed asymmetrical nucleation centers where the reversal begins for one direction of the field only and is characterized by an acute asymmetry of domain-wall mobility. We have also observed magnetic domains with a continuously varying average magnetization, which can be explained in terms of the coexistence of three magnetic phases: up, down, and striped.

Antisymmetric magnetoresistance in magnetic multilayers with perpendicular anisotropy.

While magnetoresistance (MR) has generally been found to be symmetric in applied field in nonmagnetic or magnetic metals, we have observed antisymmetric MR in Co/Pt multilayers. Simultaneous domain imaging and transport measurements show that the antisymmetric MR is due to the appearance of domain walls that run perpendicular to both the magnetization and the current, a geometry existing only in materials with perpendicular magnetic anisotropy. As a result, the extraordinary Hall effect gives rise to circulating currents in the vicinity of the domain walls that contributes to the MR. The antisymmetric MR and extraordinary Hall effect have been quantitatively accounted for by a theoretical model.

Tensile strength of wound closure with cyanoacrylate glue.

2-Octyl cyanoacrylate tissue adhesive is increasingly being used for closure of traumatic lacerations. Data regarding the strength of incisions closed with 2-octyl cyanoacrylate are limited. We compared the strength of disruption of closure with glue with that of more conventional methods of wound closure. Segments of fresh porcine skin measuring 3.5 x 10 cm were approximated by one of four methods: 1) 2-octyl cyanoacrylate glue, 2) surgical staples, 3) 0.5 inch Steri-Strips, and 4) interrupted 4-0 poliglecaprone 25 sutures in a subcuticular fashion. Fifteen specimens were used to test each type of closure. The strength of closure was tested on an Instron 4502 tensionometer. The peak force required for disruption of the closure was recorded and the strength of the closure was compared. Staples provided the strongest closure. Skin glue proved superior to Steri-Strips but inferior to stapled closure. The difference between skin glue and suture closure was not statistically significant (P = 0.12). Patterns of failure differed between the groups. Skin glue failed because of disruption of the skin-glue interface. 2-Octyl cyanoacrylate glue provides a wound closure that is similar to closure with an interrupted subcuticular absorbable suture. This study validates the clinical use of skin glue for closure of surgical incisions. The technique should be used with caution in areas of the body that are subject to tension.

Port-site recurrence reproduced in the VX-2 rabbit carcinoma model: an in vivo model comparing laparoscopic port sites and open incisions.

BACKGROUND: The use of advanced laparoscopy remains controversial in the field of surgical oncology because the potential for port-site recurrence may violate sound oncologic principles. Two mechanisms are theorized to be the cause of port-site recurrences: first, indirect contamination caused by pneumoperitoneum, aerosolization, or intraperitoneal spread, and second, direct contamination by physical trocar seeding. METHODS: A VX-2 carcinoma cell suspension was transferred under the left renal capsule of 31 rabbits with either an open flank incision (16) or laparoscopy (15). Animals were observed for tumor recurrence at the video port, the working port, and the open incision. Intraoperative findings and necropsy were used to document recurrence. RESULTS: The open incision technique resulted in local tumor recurrence in 1/16 animals with 16/16 viable intraabdominal tumors. The laparoscopic technique resulted in 0/15 video port-site recurrences and 9/15 working port-site recurrences, with 14/15 viable intraabdominal tumors. Recurrence at the laparoscopic working port occurred more frequently than in the open (P < 0.02) or laparoscopic video port groups (P < 0.007). No significant difference existed in recurrence between the open incision and the laparoscopic video port (P > 0.5). CONCLUSIONS: Laparoscopic port-site recurrences can be reproduced using the transplantable VX-2 rabbit carcinoma model. In the VX-2 model, trocar recurrence is the result of direct contamination via surgical instrumentation of viable tumor cells. The effect of the pneumoperitoneum or intraperitoneal cytological spillage (indirect contamination) does not have any effect on trocar recurrence. This model can be used to test and improve laparoscopic techniques to minimize the risk of port-site recurrence. Until technological advances have eliminated the risk of trocar recurrences, direct contact between malignant cells and laparoscopic instruments should be performed with caution.

Facial fractures in a level I trauma centre: the importance of protective devices and alcohol abuse.

Urban trauma centres have recently noted a shift in the causative mechanism of facial fractures away from motor vehicle crashes (MVC) to blunt assaults (BA). This study was conducted to examine the incidence and aetiology of facial fractures at our institution as well as the relationship with alcohol and protective device use. Trauma registry records of all patients admitted to a level I trauma centre from 1 January 1988 to 1 January 1999 were reviewed. There were 13594 trauma admissions during the 11-year period. Facial fractures were sustained by 1429 patients (10.5%) and this group forms the subject of this study. MVC was the predominant aetiology (59.9%) followed by BA (18.8%). Facial fractures were found in 9.5% of restrained MVC patients compared to 15.4% of unrestrained patients (P<0.00l). Non-helmeted motorcyclists were four times more likely to sustain facial fractures (4.3% vs. 18.4%) than helmeted patients (P<0.00l). 39.6% of patients in the MVC group were legally intoxicated compared to 73.5% in the BA group (P<0.00l). 45.4% of unrestrained patients with facial fractures were intoxicated compared to 11.8% of restrained MVC patients with facial fractures (P<0.001). MVC continue to be the primary aetiology of facial fractures in our trauma population. Protective devices decrease the incidence of facial fractures. Lack of protective device use and the consumption of alcohol correlate with sustaining facial fractures.

Asymmetry in elementary events of magnetization reversal in a ferromagnetic/antiferromagnetic bilayer.

Real-time magneto-optical indicator film images reveal distinct asymmetry in the motion of a single domain wall in a wedged-NiFe/uniform-FeMn bilayer due to the nucleation and behavior of an exchange spring in the antiferromagnetic layer. Magnetization reversal from the ground state begins at the thick end of the wedge where the exchange anisotropy field (HE) is minimal and the magnetostatic field (HMS) is maximal, whereas reversal into the ground state begins from the thin end where HE is maximal and HMS is minimal.

Managing the nondeflating urethral catheter.

BACKGROUND: Urethral catheterization is a routinely performed procedure in hospitalized patients. Numerous complications have been reported secondary to urethral catheter placement. METHODS: The medical literature was searched using the following key words: "urethral catheter," "complications," and "management." A case report is described and a review of the literature is provided to assist in managing the nondeflating urethral catheter balloon. RESULTS AND CONCLUSIONS: All physicians who order urethral catheters must be aware of the possibility of a nondeflating catheter balloon and be comfortable with its initial management. The literature has an abundance of techniques for managing the nondeflating urethral catheter balloon. The approach and algorithm provided serve as a guide for the management of this complication by the family physician.

Predicting conversion of laparoscopic cholecystectomy for acute cholecystitis.

BACKGROUND AND OBJECTIVES: Laparoscopic cholecystectomy can be safely performed in patients with acute cholecystitis. However, the rate of conversion to open cholecystectomy remains higher when compared with patients with chronic cholecystitis. Preoperative clinical or laboratory parameters that could predict the need for conversion may assist the surgeon in preoperative or intraoperative decision making. This could have cost-saving implications. METHODS: A retrospective review of 46 patients undergoing laparoscopic cholecystectomy for acute cholecystitis was performed. Records were assessed for preoperative clinical, laboratory and radiographic parameters on admission. Temperature and laboratory parameters were also recorded prior to surgery after an initial period of hospitalization that included intravenous antibiotics. The effect of admission and preoperative parameters as well as the trend in these parameters prior to surgery upon the rate of conversion to open cholecystectomy was assessed. RESULTS: Ten patients (22%) required conversion to open cholecystectomy. Conversion was required more often in males (43%) when compared with females (4%) (p=0.003). Conversion rate was 30% in patients with increased wall thickness by ultrasound compared with 12% for patients without wall thickening (p=ns). No admission or preoperative laboratory values predicted conversion. The trend in the patient's temperature (p=0.0003) and serum LDH value (p=0.043) predicted the need for conversion to open surgery. CONCLUSIONS: Preoperative prediction of the need for open cholecystectomy remains elusive. Male patients and patients with rising temperature and LDH levels while on intravenous antibiotics require conversion at increased frequency. However, the benefits of laparoscopic cholecystectomy warrant an attempt at laparoscopic removal in most patients with acute cholecystitis.

Energy-Filtered High-Resolution Electron Microscopy for Quantitative Solid State Structure Determination.

Energy-filtered (or selected) electron imaging is one of the future directions of high-resolution electron microscopy (HREM). In this paper, the characteristics and applications of energy-selected electron imaging at high-resolution for structure determinations are illustrated. It is shown that image contrast can be dramatically improved with the use of an energy filter. High-resolution chemical-sensitive imaging using ionization-loss electrons is demonstrated in studies of Ni/Ti and Al/Ti multilayer thin films. It is also shown that the spatial resolution of energy-selected ionization edge electron images is dominated by the signal-to-noise ratio. Experimental parameters which may be selected to improve the signal-to-noise ratio are discussed.

An in vitro diffusion model for the study of calcification of bovine pericardium tissue.

Bovine pericardium (BP) is extensively used for the production of heart valve bioprostheses. BP has excellent mechanical properties but a limited lifespan because of intrinsic subsurface calcification in vivo. In this study, the in vitro mineralization of BP was investigated by a novel diffusion cell model. In two sets of experiments, glutaraldehyde-treated BP membranes were placed between two compartments, both of which contained calcium phosphate solutions made by equilibration of octacalcium phosphate (Exp I) or dicalcium phosphate dihydrate (Exp II) in phosphoric acid. The movement of calcium (Ca), phosphate (P), and protons through the BP membrane was followed throughout the diffusion process. Histology, scanning electron microscopy, wet chemical analysis, and energy dispersive X-ray analyses provided good evidence of subsurface mineralization of BP that resembled in vivo mineral deposition. Energy dispersive x-ray microanalyses found a Ca/P heterogeneity of the early subsurface mineral that formed in the membrane. The use of a diffusion cell to model BP calcification under well-characterized conditions has led to in vitro mineralization that more closely matches that observed in vivo. The results suggest that this in vitro diffusion model can be used to study the mechanism of pathological mineralization. This model has the potential to provide rapid, inexpensive, basic information about the mineralization process.

Extended aortic arch anastomosis for repair of coarctation in infancy.

Surgical repair of coarctation of the aorta was performed in 17 infants, median age 14 days, median weight 3.5 kg. Extended end-to-end aortic arch anastomosis was used. A long incision was made in the inferior aspect of the aortic isthmus and arch, which was then anastomosed to the obliquely trimmed distal aorta. The aortic arch was hypoplastic in eight patients. Mean cross-clamp time was 17.1 min. Pulmonary artery bands were placed in five patients. Follow-up two-dimensional echocardiographic and Doppler studies on 13 patients 1 to 56 months after surgery demonstrated normal distal aortic flow in 10, slightly decreased flow in two, and diminished flow in one. Patients with abnormal Doppler flow showed no gradient in one case and a 30 mm Hg gradient in two. Extended aortic arch anastomosis is safe in infancy, leaves no native coarctation shelf tissue in the repaired segment, does not sacrifice the subclavian artery, is useful in hypoplastic isthmus, and is at low risk to develop aneurysm or recoarctation.