Post mortem computed tomography and core needle biopsy in comparison to autopsy in eleven bernese mountain Dogs with histiocytic sarcoma

Background: Bernese mountain dogs are reported to have a shorter life expectancy than other breeds. A Major reason for this has been assigned to a high tumour prevalence, especially of histiocytic sarcoma. The efforts made by the breeding clubs to improve the longevity with the help of genetic tests and breeding value estimations are impeded by insufficiently reliable diagnoses regarding the cause of death. The current standard for post mortem examination in animals is performance of an autopsy. In human forensic medicine, imaging modalities, such as computed tomography and magnetic resonance imaging, are used with increasing frequency as a complement to autopsy. The present study investigates, whether post mortem computed tomography in combination with core needle biopsy is able to provide a definitive diagnosis of histiocytic sarcoma. For this purpose we have analysed the results of post mortem computed tomography and core needle biopsy in eleven Bernese mountain dogs. In the subsequent autopsy, every dog had a definitive diagnosis of histiocytic sarcoma, based on immunohistochemistry. Results: Computed tomography revealed space-occupying lesions in all dogs. Lesion detection by post mortem computed tomography was similar to lesion detection in autopsy for lung tissue (9 cases in computed tomography / 8 cases in autopsy), thoracic lymph nodes (9/8), spleen (6/7), kidney (2/2) and bone (3/3). Hepatic nodules, however, were difficult to detect with our scanning protocol (2/7). Histology of the core needle biopsies provided definitive diagnoses of histiocytic sarcoma in ten dogs, including confirmation by immunohistochemistry in six dogs. The biopsy samples of the remaining dog did not contain any identifiable neoplastic cells. Autolysis was the main reason for uncertain histological diagnoses. Conclusions: Post mortem computed tomography is a fast and effective method for the detection of lesions suspicious for histiocytic sarcoma in pulmonary, thoracic lymphatic, splenic, osseous and renal tissue. Optimization of the procedure regarding the scanning protocol and tissue sample size and number will improve the accuracy of the method. Keywords: Post mortem computed tomography, Core needle biopsy, Bernese mountain dog, Histiocytic sarcoma, Autopsy

Accidental infection of veterinary personnel with Mycobacterium tuberculosis at necropsy: a case study

Mycobacterium tuberculosis is the main cause of human tuberculosis. Infection in companion animals is mainly acquired from close contact to a diseased human patient and hence rarely diagnosed in countries with low tuberculosis incidence rates. Therefore the general awareness of the disease might be low. Here we report the potential risk of infection for veterinary personnel with M. tuberculosis during the clinical and pathological examination of a dog with unexpected disseminated tuberculosis. The dog had presented with symptoms of a central nervous system disease; rapid deterioration prevented a complete clinical workup, however. Post-mortem examination revealed systemic mycobacteriosis, and M. tuberculosis was identified by PCR amplification of DNA extracts from paraffin-embedded tissue sections and spoligotyping. Contact investigations among the owners and veterinary personnel using an IFN-? release assay indicated that the index dog did not infect humans during its lifetime. Serological and IFN-? release assay results of one of two cats in direct contact with the index dog, however, suggested that transmission of M. tuberculosis might have occurred. Importantly, all three pathologists performing the necropsy on the dog tested positive. Accidental infection was most likely due to inhalation of M. tuberculosis containing aerosols created by using an electric saw to open the brain cavity. As a consequence routine necropsy procedures have been adapted and a disease surveillance program, including tuberculosis, has been initiated. Our results highlight the importance of disease awareness and timely diagnosis of zoonotic infectious agents in optimizing work safety for veterinary personnel.

Outer skull landmark-based coordinates for measurement of cerebral blood flow and intracranial pressure in rabbits

Despite the increased use of intracranial neuromonitoring during experimental subarachnoid hemorrhage (SAH), coordinates for probe placement in rabbits are lacking. This study evaluates the safety and reliability of using outer skull landmarks to identify locations for placement of cerebral blood flow (CBF) and intraparenchymal intracranial pressure (ICP) probes. Experimental SAH was performed in 17 rabbits using an extracranial-intracranial shunt model. ICP probes were placed in the frontal lobe and compared to measurements recorded from the olfactory bulb. CBF probes were placed in various locations in the frontal cortex anterior to the coronary suture. Insertion depth, relation to the ventricular system, and ideal placement location were determined by post-mortem examination. ICP recordings at the time of SAH from the frontal lobe did not differ significantly from those obtained from the right olfactory bulb. Ideal coordinates for intraparenchymal CBF probes in the left and right frontal lobe were found to be located 4.6±0.9 and 4.5±1.2 anterior to the bregma, 4.7±0.7mm and 4.7±0.5mm parasagittal, and at depths of 4±0.5mm and 3.9±0.5mm, respectively. The results demonstrate that the presented coordinates based on skull landmarks allow reliable placement of intraparenchymal ICP and CBF probes in rabbit brains without the use of a stereotactic frame.

Response of the rat spinal cord to X-ray microbeams

BACKGROUND AND PURPOSE: To quantify the late dose-related responses of the rat cervical spinal cord to X-ray irradiations by an array of microbeams or by a single millimeter beam. MATERIALS AND METHODS: Necks of anesthetized rats were irradiated transversely by an 11mm wide array of 52 parallel, 35μm wide, vertical X-ray microbeams, separated by 210μm intervals between centers. Comparison was made with rats irradiated with a 1.35mm wide single beam of similar X-rays. Rats were killed when paresis developed, or up to 383days post irradiation (dpi). RESULTS: Microbeam peak/valley doses of ≈357/12.7Gy to 715/25.4Gy to an 11mm long segment of the spinal cord, or single beam doses of ≈146-454Gy to a 1.35mm long segment caused foreleg paresis and histopathologically verified spinal cord damage; rats exposed to peak/valley doses up to 253/9Gy were paresis-free at 383dpi. CONCLUSIONS: Whereas microbeam radiation therapy [MRT] for malignant gliomas implanted in rat brains can be safe, palliative or curative, the high tolerance of normal rat spinal cords to similar microbeam exposures justifies testing MRT for autochthonous malignancies in the central nervous system of larger animals with a view to subsequent clinical applications.

Synchrotron X-ray interlaced microbeams suppress paroxysmal oscillations in neuronal networks initiating generalized epilepsy

Radiotherapy has shown some efficacy for epilepsies but the insufficient confinement of the radiation dose to the pathological target reduces its indications. Synchrotron-generated X-rays overcome this limitation and allow the delivery of focalized radiation doses to discrete brain volumes via interlaced arrays of microbeams (IntMRT). Here, we used IntMRT to target brain structures involved in seizure generation in a rat model of absence epilepsy (GAERS). We addressed the issue of whether and how synchrotron radiotherapeutic treatment suppresses epileptic activities in neuronal networks. IntMRT was used to target the somatosensory cortex (S1Cx), a region involved in seizure generation in the GAERS. The antiepileptic mechanisms were investigated by recording multisite local-field potentials and the intracellular activity of irradiated S1Cx pyramidal neurons in vivo. MRI and histopathological images displayed precise and sharp dose deposition and revealed no impairment of surrounding tissues. Local-field potentials from behaving animals demonstrated a quasi-total abolition of epileptiform activities within the target. The irradiated S1Cx was unable to initiate seizures, whereas neighboring non-irradiated cortical and thalamic regions could still produce pathological oscillations. In vivo intracellular recordings showed that irradiated pyramidal neurons were strongly hyperpolarized and displayed a decreased excitability and a reduction of spontaneous synaptic activities. These functional alterations explain the suppression of large-scale synchronization within irradiated cortical networks. Our work provides the first post-irradiation electrophysiological recordings of individual neurons. Altogether, our data are a critical step towards understanding how X-ray radiation impacts neuronal physiology and epileptogenic processes.

Extranodal B-cell lymphoma in the urinary bladder with cytological evidence of concurrent involvement of the gall bladder in a cat

A 15-year-old domestic shorthair cat was presented with severe haematuria, stranguria, anorexia and lethargy of 10 days' duration. Physical examination revealed a large painful urinary bladder and pain in the cranial abdomen. Abdominal ultrasound revealed severe generalised mural thickening of both the gall bladder and the urinary bladder. Lymphoma was diagnosed on cytology of urine sediment and fine-needle aspirates of the gall bladder. Despite a transitory clinical improvement and partial remission following chemotherapy, the cat was euthanased six weeks after initial presentation due to recurrent clinical signs. Post-mortem examination confirmed a B-cell lymphoma in the urinary bladder. This report is the first description of gall bladder and bladder lymphoma in a cat.

Infectious endocarditis caused by gas-producing Escherichia coli in a diabetic dog

A 10-year-old, female West Highland white terrier was presented with poorly controlled diabetes mellitus and a previously undetected heart murmur. Emphysematous cystitis, emphysematous peritonitis and infective endocarditis of the tricuspid valve with gas accumulation were diagnosed with radiographs, including non-selective angiocardiography. The diagnoses were confirmed by post-mortem examination and positive cultures for Escherichia coli in blood, urine and tricuspid valve tissue samples.

Cerebellar cortical degeneration with selective granule cell loss in Bavarian mountain dogs

Three Bavarian mountain dogs aged between 18 and 20 months, not related to each other, were presented with chronic signs of cerebellar dysfunction. On sagittal T2-weighted magnetic resonance imaging brain images, the tentative diagnosis of cerebellar hypoplasia was established based on an enlarged cerebrospinal fluid space around the cerebellum and an increased cerebrospinal fluid signal between the folia. Post-mortem examination was performed in one dog and did show an overall reduction of cerebellar size. On histopathologic examination, a selective loss of cerebellar granule cells with sparing of Purkinje cells was evident. Therefore, the Bavarian mountain dog is a breed where cerebellar cortical degeneration caused by the rather exceptional selective granule cell loss can be seen as cause of chronic, slowly progressive cerebellar dysfunction starting at an age of several months.

Primary prostatic haemangiosarcoma causing severe haematuria in a dog

A 10-year-old, entire, male, mixed-breed dog was presented for severe haematuria and stranguria. Ultrasound revealed a large intraluminal urinary bladder blood clot and a prostatic space-occupying lesion. Invasion of the lesion into the prostatic urethra was detected ultrasonographically during compression of the urinary bladder. Post-mortem examination revealed primary prostatic haemangiosarcoma infiltrating the urethra. Haemangiosarcoma should be considered as a rare cause of prostatic mass lesions, haematuria or lower urinary tract signs in dogs.

Frequency of PRRS live vaccine virus (European and North American genotype) in vaccinated and non-vaccinated pigs submitted for respiratory tract diagnostics in North-Western Germany

The frequency of PRRSV corresponding to live vaccines and wild-type was determined in 902 pigs from North-Western Germany submitted for post-mortem examination. Overall, 18.5% of the samples were positive for the EU wild-type virus. EU genotype vaccine virus was detected in 1.3% and the NA genotype vaccine virus in 8.9% of all samples. The detection of the EU vaccine was significantly higher in pigs vaccinated with the corresponding vaccine (OR=9.4). Pigs vaccinated with NA genotype had significantly higher detection chances for the corresponding vaccine virus when compared to non-vaccinated animals (OR=3.34) animals, however, NA vaccine was also frequently detected in non-vaccinated pigs. Concluding, the dynamics of NA genotype vaccine and EU wild-type virus corresponds with studies on PRRSV spread in endemically infected herds. The potential of spontaneous spread of the NA genotype vaccine should be considered in the planning of eradication programs.

Bacteriological diagnosis and molecular strain typing of Mycobacterium bovis and Mycobacterium caprae

The primary isolation of a Mycobacterium sp. of the Mycobacterium tuberculosis complex from an infected animal provides a definitive diagnosis of tuberculosis. However, as Mycobacterium bovis and Mycobacterium caprae are difficult to isolate, particularly for animals in the early stages of disease, success is dependent on the optimal performance of all aspects of the bacteriological process, from the initial choice of tissue samples at post-mortem examination or clinical samples, to the type of media and conditions used to cultivate the microorganism. Each step has its own performance characteristics, which can contribute to sensitivity and specificity of the procedure, and may need to be optimized in order to achieve the gold standard diagnosis. Having isolated the slow-growing mycobacteria, species identification and fine resolution strain typing are keys to understanding the epidemiology of the disease and to devise strategies to limit transmission of infection. New technologies have emerged that can now even discriminate different isolates from the same animal. In this review we highlight the key factors that contribute to the accuracy of bacteriological diagnosis of M. bovis and M. caprae, and describe the development of advanced genotyping techniques that are increasingly used in diagnostic laboratories for the purpose of supporting detailed epidemiological investigations.

Diagnosis of fatal pulmonary fat embolism with minimally invasive virtual autopsy and post-mortem biopsy

We report a case of a 78-year-old female with a proximal femur fracture caused by an accidental fall who died suddenly 1h after orthopaedic prosthesis insertion. Post-mortem computed tomography (CT) scan and histological examination of samples obtained with post-mortem percutaneous needle biopsies of both lungs were performed. Analysis of the medical history and the clinical scenario immediately before death, imaging data, and biopsy histology established the cause of death without proceeding to traditional autopsy. It was determined to be acute right ventricular failure caused by massive pulmonary fat embolism. Although further research in post-mortem imaging and post-mortem tissue sampling by needle biopsies is necessary, we conclude that the use of CT techniques and percutaneous biopsy, as additional tools, can offer a viable alternative to traditional autopsy in selected cases and may increase the number of minimally invasive forensic examinations performed in the future.

Performance of laser fluorescence devices, visual and radiographic examination for the detection of occlusal caries in primary molars

The aim of this in vitro study was to compare the performance of two laser fluorescence devices (LF, LFpen), conventional visual criteria (VE), ICDAS and radiographic examination on occlusal surfaces of primary teeth. Thirty-seven primary human molars were selected from a pool of extracted teeth, which were stored frozen at -20°C until use. Teeth were assessed twice by two experienced examiners using laser fluorescence devices (LF and LFpen), conventional visual criteria, ICDAS and bitewing radiographs, with a 2-week interval between measurements. After measurement, the teeth were histologically prepared and assessed for caries extension. The highest sensitivity was observed for ICDAS at D(1) and D(3) thresholds, with no statistically significant difference when compared to the LF devices, except at the D(3) threshold. Bitewing radiographs presented the lowest values of sensitivity. Specificity at D(1) was higher for LFpen (0.90) and for VE at D(3) (0.94). When VE was combined with LFpen the post-test probabilities were the highest (94.0% and 89.2% at D(1) and D(3) thresholds, respectively). High values were observed for the combination of ICDAS and LFpen (92.0% and 80.0%, respectively). LF and LFpen showed the highest values of ICC for interexaminer reproducibility. However, regarding ICDAS, BW and VE, intraexaminer reproducibility was not the same for the two examiners. After primary visual inspection using ICDAS or not, the use of LFpen may aid in the detection of occlusal caries in primary teeth. Bitewing radiographs may be indicated only for approximal caries detection.

Pros and cons of post-mortem CT imaging on aspiration diagnosis

Recently, the field of forensics has experienced a rapid increase in the use of modern cross-sectional imaging in forensic investigations. We examined the value of post-mortem computed tomography (CT) imaging relative to autopsy for distinguishing aspiration into the lungs from airways, from lung alterations due to other causes, and for identifying the aspirated material. We selected 54 bodies submitted to whole-body CT scanning prior to autopsy. All cases had autopsy findings of blood (31 cases), fresh water (12 cases), or gastric content (11 cases) aspiration. The radiological images were retrospectively analyzed for airway and lung aspiration. In all cases, CT imaging detected pulmonary abnormalities suggestive of aspiration. Nevertheless, analysis of the CT images alone was not able to identify the aspirated material or to distinguish pulmonary findings of aspiration from lung changes due to other causes, except for a few cases of hemo-aspiration. However, due to its ability to visualize the entire parenchyma, CT imaging was superior to autopsy in providing additional data about the distribution and severity of the aspiration as well as in detecting small abnormalities. Post-mortem CT imaging should be considered as a superior tool for forensic investigations of aspiration due to its ability to document diagnostic conclusions and to guide the forensic pathologist during lung tissue examination.

Incidental findings in post-mortem CT: Calcified ligamentum arteriosum

This case report describes the incidental finding of a calcified ligamentum arteriosum during post-mortem CT examination. The calcification of the ligament was confirmed at autopsy. Subsequent histological examination revealed the presence of cartilage-like and bone-like tissue as well as extended calcification areas. The importance of not confusing this normal post-mortem CT finding with vessel pathology is being emphasized.