Assessment of the performance of the Ames MPF™ assay: A multicenter collaborative study with six coded chemicals.

The Ames MPF™ is a miniaturized, microplate fluctuation format of the Ames test. It is a standardized, commercially available product which can be used to assess mutagenicity in Salmonella and E. coli strains in 384-well plates using a color change-based readout.

Combination of Multidimensional Instrumental Analysis and the Ames Test for the Toxicological Evaluation of Mineral Oil Aromatic Hydrocarbons.

Mineral oil aromatic hydrocarbons (MOAHs) include mutagenic and carcinogenic substances and are considered a potential health risk. Current methods address the total MOAH content but cannot address the actual toxicological hazard of individual components. This work presents a combined methodology closing those gaps: high-performance liquid chromatography (HPLC) coupled to gas chromatography with flame ionization detection was used to determine the MOAH content.

Spo11 generates gaps through concerted cuts at sites of topological stress.

Meiotic recombination is essential for chromosome segregation at meiosis and fertility. It is initiated by programmed DNA double-strand breaks (DSBs) introduced by Spo11, a eukaryotic homologue of an archaeal topoisomerase (Topo VIA). Here we describe previously uncharacterized Spo11-induced lesions, 34 to several hundred base pair-long gaps, which are generated by coordinated pairs of DSBs termed double DSBs.

Mutagenicity assessment of food contact material migrates with the Ames MPF assay.

A major challenge in the safety assessment of food contact materials (FCM) is the evaluation of unknown non-intentionally added substances (NIAS). Even though consumer exposure levels may be quantitatively low, these substances are considered to be of high toxicological concern if they act as DNA reactive mutagens. From a safety assessment perspective, it is therefore important to detect their presence in FCM migrates.

Adenosine to Inosine editing frequency controlled by splicing efficiency.

Alternative splicing and adenosine to inosine (A to I) RNA-editing are major factors leading to co- and post-transcriptional modification of genetic information. Both, A to I editing and splicing occur in the nucleus. As editing sites are frequently defined by exon-intron basepairing, mRNA splicing efficiency should affect editing levels.

OPG-Fc treatment in growing pigs leads to rapid reductions in bone resorption markers, serum calcium, and bone formation markers.

Inhibition of the receptor activator of NF-κB ligand (RANKL) is a novel therapeutic option in the treatment of osteoporosis and related diseases. The aim of this study was to evaluate bone metabolism and structure in pigs after RANKL inhibition. 12 growing pigs were assigned to 2 groups with 6 animals each.

Radiographic and ultrasonographic diagnosis of stenosing tenosynovitis of the abductor pollicis longus muscle in dogs.

Stenosing tenosynovitis of the abductor pollicis longus muscle causes chronic front limb lameness in dogs. The lesion, similar to de Quervain's tenosynovitis in people, is caused by repetitive movements of the carpus. Thirty dogs with front limb lameness, painful carpal flexion, and a firm soft tissue swelling medial to the carpus were examined prospectively.

[X-ray and CT morphology of atlas variants in the dog].

To investigate variations in atlas shape in dogs the image archives of the Department for Small Animals and Horses, University of Vienna, and The Royal Veterinary College, University of London were searched for radiographs and CT images of the canine atlas. 32 radiographic and 78 CT studies, including 51 toy and 54 large breed dogs, were retrieved and analysed. Five dogs had both radiographs and CT scans.

Synovial cyst of the fifth digit in a cat.

A synovial cyst of the fifth digit of the left forelimb in a 15-year-old cat was diagnosed. Radiographs showed severe osteoarthritis of the interphalangeal and metacarpophalangeal joints with soft tissue swelling. An ultrasound examination of the digit revealed a cystic structure.

Brachycephalic feline noses: CT and anatomical study of the relationship between head conformation and the nasolacrimal drainage system.

Aims: A study was designed to evaluate the influence of head conformation on the course of the nasolacrimal drainage system (NDS) in 31 brachycephalic and 15 mesocephalic cats using computed tomography (CT), CT-dacryocystography and anatomical methods.

Findings: The higher the degree of brachycephalia, the more the facial bones and upper canine teeth are displaced dorsally (ie, the more pronounced the dorsorotation). Dorsorotation leads to abnormal dislocation of the ventral nasal concha and to almost horizontally rotated upper canine teeth, and thus a steeply oriented NDS.

Influence of borderline hip dysplasia on joint kinematics of clinically sound Belgian Shepherd dogs.

Objective: To detect changes in joint kinematics of clinically sound dogs with or without radiographically detectable borderline hip dysplasia (HD).

Animals: 20 Belgian Shepherd Dogs (Malinois; mean +/- SD age, 2.75 +/- 1.

Traumatic avulsion fracture of the lesser trochanter in a dog.

A 15-month-old 25 kg female spayed American Staffordshire Terrier was examined to determine the cause of a six month period of lameness of the left pelvic limb. Signs of severe pain were evident on hyperextension and simultaneous internal rotation or abduction of the left hip joint; crepitus or instabiltiy was not detected. The diagnosis of avulsion fracture of the lesser trochanter was based on radiographs, computed tomography (CT) and magnetic resonance imaging (MRI), supported by initial findings such as lameness and hip joint pain in extension.

Hypoxia- and radiation-inducible, breast cell-specific targeting of retroviral vectors.

To facilitate a more efficient radiation and chemotherapy of mammary tumours, synthetic enhancer elements responsive to hypoxia and ionizing radiation were coupled to the mammary-specific minimal promoter of the murine whey acidic protein (WAP) encoding gene. The modified WAP promoter was introduced into a retroviral promoter conversion (ProCon) vector. Expression of a transduced reporter gene in response to hypoxia and radiation was analysed in stably infected mammary cancer cell lines and an up to 9-fold increase in gene expression demonstrated in comparison to the respective basic vector.

Comparative assessment of bone mineral measurements obtained by use of dual-energy x-ray absorptiometry, peripheral quantitative computed tomography, and chemical-physical analyses in femurs of juvenile and adult dogs.

Objective: To compare bone mineral measurements obtained by use of dual-energy x-ray absorptiometry (DEXA), peripheral quantitative computed tomography (pQCT), and chemical-physical analyses and determine effects of age and femur size on values obtained for the various techniques.

Sample Population: Femurs obtained from 15 juvenile and 15 adult large-breed dogs.

Procedure: n each femur, 7 regions of interest were examined by use of DEXA to measure the bone mineral content (BMC) and bone mineral density (BMD), and 5 were examined by use of pQCT to measure BMD.

Appearance and incidence of sacroiliac joint disease in ventrodorsal radiographs of the canine pelvis.

Ventrodorsal (VD) radiographs of cadaveric pelves of large and giant breeds (n = 40) and of the corresponding bone specimens were made. Gross changes seen in the specimens were marked with metal wire or radiopaque paint to relate radiographic changes to the postmortem appearance of degenerative sacroiliac (SI) joint lesions. Two positioning techniques were used, resulting in two radiographs for each specimen.

CT features of alveolitis and sinusitis in horses.

Sinusitis is a common disorder in horses and may result from trauma, dental diseases, or space-occupying lesions. Radiography can only provide a limited amount of information. Computed tomography (CT) has been documented as an alternative imaging method.

The canine trochanteric fossa: a radiographic and anatomic study.

Radiographic features of the region of the trochanteric fossa were evaluated bilaterally on 175 ventrodorsal radiographs of canine hip joints and findings were compared to anatomic specimens. The fossa showed a variable radiographic appearance, which was affected by positioning and anatomic diversity. On a small number of radiographs (n = 12), the trochanteric fossa was clearly defined as a circular area of radiopacity surrounded by a radiolucent halo.

Evaluation of magnetic resonance imaging techniques in the equine digit.

An anatomic study of the equine digit using magnetic resonance imaging (MRI) was performed. Seventeen isolated forelimbs and one hindleg of nine warmblood horses were imaged in transverse, sagittal, and dorsal planes with a 1.5 Tesla magnet using T1-, T2- proton density-weighted spin echo sequences as well as T2 gradient echo sequences.

[Radiologically detectable changes in the radial annular ligament and the supinator muscle of the domestic cat (Felis catus)].

Elbow joints of a random sample of 59 cats were investigated by means of X-rays and dissection as well as histologically and by making cuts through synthetic resin-embedded joints. Bone-dense shadow craniolateral to the elbow joint was observed in X-ray images of 23 limbs (about 20%). Furthermore 8 of these 23 elbow joints (about 7%) showed signs of arthrotic alteration.