Atomic structure of granulin determined from native nanocrystalline granulovirus using an X-ray free-electron laser.

To understand how molecules function in biological systems, new methods are required to obtain atomic resolution structures from biological material under physiological conditions. Intense femtosecond-duration pulses from X-ray free-electron lasers (XFELs) can outrun most damage processes, vastly increasing the tolerable dose before the specimen is destroyed. This in turn allows structure determination from crystals much smaller and more radiation sensitive than previously considered possible, allowing data collection from room temperature structures and avoiding structural changes due to cooling. Regardless, high-resolution structures obtained from XFEL data mostly use crystals far larger than 1 µm3 in volume, whereas the X-ray beam is often attenuated to protect the detector from damage caused by intense Bragg spots. Here, we describe the 2 Å resolution structure of native nanocrystalline granulovirus occlusion bodies (OBs) that are less than 0.016 µm3 in volume using the full power of the Linac Coherent Light Source (LCLS) and a dose up to 1.3 GGy per crystal. The crystalline shell of granulovirus OBs consists, on average, of about 9,000 unit cells, representing the smallest protein crystals to yield a high-resolution structure by X-ray crystallography to date. The XFEL structure shows little to no evidence of radiation damage and is more complete than a model determined using synchrotron data from recombinantly produced, much larger, cryocooled granulovirus granulin microcrystals. Our measurements suggest that it should be possible, under ideal experimental conditions, to obtain data from protein crystals with only 100 unit cells in volume using currently available XFELs and suggest that single-molecule imaging of individual biomolecules could almost be within reach.

Assessment of the medium- to long-term radiographically confirmed outcome for juvenile dogs with hip dysplasia treated with double pelvic osteotomy.

OBJECTIVE: To assess the medium- to long-term radiographically confirmed outcomes in juvenile dogs with hip dysplasia (HD) that did and did not undergo double pelvic osteotomy (DPO). STUDY DESIGN: Retrospective case-controlled. ANIMALS: Twenty-six dogs with HD that were candidates for DPO; 22 dogs underwent DPO (16 bilateral, six unilateral); four dogs did not. METHODS: Initial and follow-up radiographs of DPO candidates (2011-2017) that did and did not undergo surgery were reviewed, and the British Veterinary Association and Kennel Club Hip Dysplasia Scheme score (BVA-HD), osteoarthritis score (OAS) and laxity index score (LI) were determined. Baseline and follow-up BVA-HD, OAS, and change in radiographically confirmed scores were compared by using analysis of variance for correlated samples. RESULTS: There was no significant difference in BVA-HD or OAS between surgically treated and nonsurgically treated cohorts at baseline. Follow-up radiographs (median, 49 months) revealed that most (34/38) hips had a BVA-HD ≤10 after DPO, while four of eight hips from the nonsurgical cohort had BVA-HD >10. Follow-up BVA-HD and OAS were lower in hips after surgery (BVA-HD median 2.15, interquartile range [Q1-Q3] 1.3-4.1; OAS median 1.9, Q1-Q3 1.1-4.1) compared with the nonsurgically treated cohort (BVA-HD median 11.4, Q1-Q3 8.1-17.5, P < .01; OAS median 7.0, Q1-Q3 5.1-13.4, P < .01). Seven hips with an LI >1 had no radiographically confirmed progression of osteoarthritis after DPO. CONCLUSION: Double pelvic osteotomy prevented radiographically confirmed progression of osteoarthritis in the medium- to long-term. Laxity index score > 1 was not a contraindication for DPO in this study. CLINICAL SIGNIFICANCE: Double pelvic osteotomy prevents progression of radiographically confirmed features of osteoarthritis in juvenile dogs with HD.

Emergence of Brucella suis in dogs in New South Wales, Australia: clinical findings and implications for zoonotic transmission.

BACKGROUND: Animal reservoirs of brucellosis constitute an ongoing threat to human health globally, with foodborne, occupational and recreational exposures creating opportunities for transmission. In Australia and the United States, hunting of feral pigs has been identified as the principal risk factor for human brucellosis due to Brucella suis. Following increased reports of canine B. suis infection, we undertook a review of case notification data and veterinary records to address knowledge gaps about transmission, clinical presentation, and zoonotic risks arising from infected dogs. RESULTS: Between 2011 and 2015, there was a 17-fold increase in the number of cases identified (74 in total) in New South Wales, Australia. Spatial distribution of cases largely overlapped with high feral pig densities in the north of the state. Ninety per cent of dogs had participated directly in pig hunting; feeding of raw feral pig meat and cohabitation with cases in the same household were other putative modes of transmission. Dogs with confirmed brucellosis presented with reproductive tract signs (33 %), back pain (13 %) or lameness (10 %); sub-clinical infection was also common (40 %). Opportunities for dog-to-human transmission in household and occupational environments were identified, highlighting potential public health risks associated with canine B. suis infection. CONCLUSIONS: Brucellosis due to B. suis is an emerging disease of dogs in Australia. Veterinarians should consider this diagnosis in any dog that presents with reproductive tract signs, back pain or lameness, particularly if the dog has a history of feral pig exposure. Moreover, all people in close contact with these dogs such as hunters, household contacts and veterinary personnel should take precautions to prevent zoonotic transmission.

Effects of Angled Dynamic Compression Holes in a Tibial Plateau Levelling Osteotomy Plate on Cranially Directed Fragment Displacement.

OBJECTIVE: To compare angled dynamic compression holes in a tibial plateau levelling osteotomy (TPLO) plate to a commercially available TPLO plate in an ovine cadaveric model. STUDY DESIGN: Ovine tibias (40 bones) were mounted on a custom-made securement device and radiopaque markers were placed to aid radiographic measurements. A standard TPLO procedure was performed on each tibia with either a custom-made six-hole 3.5 mm angled compression hole plate (APlate) or a six-hole 3.5 mm standard commercial plate (SPlate). Radiographs were obtained before and after tightening of the cortical screws and evaluated by an observer blinded to the plate. Measurements of cranio-caudal displacement (CDisplacement), proximo-distal displacement (PDisplacement) in relation to the long axis of the tibia, and change in tibial plateau angle (TPA) were determined. RESULTS: CDisplacement was significantly greater in APlate (median 0.85 mm, Q1-Q3: 0.575-1.325 mm) compared to SPlate (median 0.00 mm, Q1-Q3: -0.35-0.50 mm, p < 0.0001). There were no significant differences in the PDisplacement (median 0.55 mm, Q1-Q3: 0.075-1.00 mm, p = 0.5066) or TPA change (median -0.50°, Q1-Q3: -1.225-0.25°, p = 0.1846) between the two plate types. CONCLUSION: APlate increases cranially directed displacement of the osteotomy in a TPLO procedure without causing TPA change. The reduced interfragmentary distance across the whole osteotomy could improve osteotomy healing compared to standard commercial TPLO plates.

Surgical stabilization of concomitant canine medial patellar luxation and cranial cruciate ligament disease. Effect of fixation method on postoperative complication rate and clinical outcome.

OBJECTIVES: To compare complication rates and outcomes between cases of concomitant cranial cruciate ligament (CrCL) disease and medial patellar luxation (MPL) treated using extracapsular stabilization and tibial tuberosity transposition (ECS+TTT) and tibial tuberosity transposition and advancement (TTTA). METHODS: In a multicentre retrospective study, records from four referral hospitals were reviewed for dogs with concomitant CrCL pathology and MPL treated using ECS+TTT or TTTA. Data retrieved included signalment, partial/complete CrCL tear, MPL grade, treatment performed, occurrence of postoperative complications, and postoperative outcome grade. Associations between surgical procedure and risk of complication and surgical procedure and outcome were investigated using univariable logistic regression and proportional odds logistic regression respectively. Multiple logistic regression was used to explore confounding factors. RESULTS: A total of 72 stifles were evaluated in 66 dogs; 32 stifles were stabilized using ECS+TTT and 40 using TTTA. Overall complications were 2.7 times more frequent in the ECS+TTT group and major complications occurred only in this group. The TTTA group was less likely to suffer complications (17.5%) compared to the ECS+TTT group (46.9%) (p = 0.009) and TTTA cases had lower odds of a poorer clinical outcome (p = 0.047). CLINICAL SIGNIFICANCE: Stifles stabilized using ECS+TTT are more likely to suffer from postoperative complications and a poorer clinical outcome when compared to TTTA.

Corrigendum: Double-flow focused liquid injector for efficient serial femtosecond crystallography.

This corrects the article DOI: 10.1038/srep44628.

Double-flow focused liquid injector for efficient serial femtosecond crystallography.

Serial femtosecond crystallography requires reliable and efficient delivery of fresh crystals across the beam of an X-ray free-electron laser over the course of an experiment. We introduce a double-flow focusing nozzle to meet this challenge, with significantly reduced sample consumption, while improving jet stability over previous generations of nozzles. We demonstrate its use to determine the first room-temperature structure of RNA polymerase II at high resolution, revealing new structural details. Moreover, the double-flow focusing nozzles were successfully tested with three other protein samples and the first room temperature structure of an extradiol ring-cleaving dioxygenase was solved by utilizing the improved operation and characteristics of these devices [corrected].

Chronic urinary bladder torsion causing urinary incontinence in a cat.

CASE SUMMARY: A 10-month-old female spayed domestic shorthair cat was presented for urinary incontinence. The cat was azotaemic, and ultrasound examination identified hydroureter and hydronephrosis. Subsequent computed tomography (CT) contrast pyelography allowed a diagnosis of urinary bladder torsion. Surgical findings and treatment are described. Postoperatively, incontinence and azotaemia resolved, and marked improvements were documented with ultrasound and CT in urinary tract structural abnormalities. RELEVANCE AND NOVEL INFORMATION: To our knowledge, urinary bladder torsion has not been previously reported in the cat. This case most probably occurred as a complication of ovariohysterectomy, as has been reported in the dog; however, the presenting sign of chronic urinary incontinence is unique. Response to surgical correction was favourable.