Primary Meningeal Rhabdomyosarcoma of the Spinal Cord of a Young Dog with Neuromelanocytosis and Multiple Cutaneous Neurofibromas.

A 7-week-old male black Labrador retriever puppy was presented for post-mortem examination following progressive hindlimb paralysis and multiple masses within the skin. A highly compressive and infiltrative intradural mass was found within the T9-T11 spinal cord. Microscopical and immunohistochemical analysis revealed features compatible with spindle cell rhabdomyosarcoma (RMS). The adjacent spinal cord had numerous melanin-containing cells, arranged in small nodules, predominantly within the grey matter (proposed term of 'micronodular neuromelanocytosis') and the left lateral thorax had multifocal dermal neurofibromas. In this case, the constellation of proliferative/neoplastic lesions represents a unique case presentation with unclear aetiology. Primary canine meningeal RMS of the spinal cord has not been reported previously and represents a novel differential diagnosis for spinal tumours of young dogs. Moreover, such cases should be assessed for the presence of additional congenital abnormalities.

Analysis of change in gait in the ovine stifle: normal, injured, and anterior cruciate ligament reconstructed.

BACKGROUND: Many patients who undergo anterior cruciate ligament (ACL) reconstructive surgery develop post-traumatic osteoarthritis (PTOA). ACL reconstructive surgery may not fully restore pre-injury joint biomechanics, thereby resulting in further joint damage and contributing to the development of PTOA. In an ovine model of idealized ACL reconstruction (ACL-R), it has been shown that signs of PTOA develop within surgical joints by 20 weeks post-surgery. The aim of the present study was to investigate whether altered kinematics contribute to early PTOA development within ACL-R joints of the ovine injury model by comparing the gait of these surgical animals to the gait of a stable normal control group, and an unstable injury group in which the ACL and medial collateral ligament (MCL) had been transected. METHODS: Fifteen skeletally mature female sheep were allocated evenly into 3 treatment groups: normal control, ACL-R, and ACL/MCL Tx (each group n = 5). Each animal's gait was recorded at baseline, 4 weeks post injury, and 20 weeks post injury. Principal component analysis (PCA) was used to identify the kinematic patterns that may be discriminant between treatment groups. Results from previous studies were referenced to present the amount of gross PTOA-like changes that occurred in the joints. RESULTS: ACL-R and ACL/MCL transected (Tx) animals developed a similar amount of early PTOA-like changes within the surgical joints, but differed significantly in the amount of kinematic change present at 20 weeks post-surgery. We showed that the stifle joint kinematics of ACL/MCL Tx differed significantly from those of CTRL and the majority of ACL-R animals, while no significant differences in joint kinematic changes were found between ACL-R and CTRL animals. CONCLUSIONS: These results suggest that the early PTOA-like changes reported in the ACL-R model cannot be attributed exclusively to post-surgical kinematic changes, and therefore biologic components in the post-injury environment must be contributing significantly to PTOA development.

Malignant anal sac melanoma in dogs: eleven cases (2000 to 2015).

OBJECTIVES: To report the signalment, clinical presentation, treatments pursued and outcomes of dogs with malignant anal sac melanoma. METHODS: Medical records from five institutions from January 2000 through December 2015 were reviewed and dogs with cytologically- or histologically-confirmed malignant anal sac melanoma were identified. Signalment, clinical signs, staging, cytology, histopathologic analysis, surgical and non-surgical treatments were extracted from the medical records. The referring veterinarians and owners were contacted for follow-up data. RESULTS: Eleven dogs were included and survival data was available for all. The most common clinical signs were bloody anal sac discharge and perianal licking. Initial treatments pursued included surgery (n=8), chemotherapy (n=1), and palliative treatment with pain medications and stool softeners (n=2). In an adjuvant setting, melanoma vaccine was pursued following surgery in three dogs and chemotherapy in one dog. Regardless of treatment, progression-free survival (mean 92 · 5 days) and overall survival times (median 107 days) were short. CLINICAL SIGNIFICANCE: Dogs in this case series had a guarded to poor prognosis regardless of treatment. Ten of 11 dogs were euthanased due to local or distant disease progression. Only 1 of 11 dogs was alive one year after diagnosis. An understanding of tumour behaviour in this location could lead to improved survival times with earlier diagnosis and treatment.

BCL2 and MYC are expressed at high levels in canine diffuse large B-cell lymphoma but are not predictive for outcome in dogs treated with CHOP chemotherapy.

Diffuse large B-cell lymphoma (DLBCL) is the most common haematopoietic malignancy in dogs. Recently, MYC and BCL2 expression levels determined with immunohistochemistry (IHC) were found to be prognostic in people with DLBCL. We hypothesized that canine DLBCL can be similarly subdivided into prognostic subtypes based on expression of MYC and BCL2. Cases of canine DLBCL treated with CHOP chemotherapy were retrospectively collected and 43 dogs had available histologic tissue and complete clinical follow-up. Median values of percent immunoreactive versus immunonegative cells were used to determine positive or negative expression status. Completion of CHOP was significantly associated with a positive outcome. Compared with human patients, our canine DLBCL patients had high IHC expression of both MYC and BCL2, and relative expression levels of one or both markers were not associated with clinical outcome.

Immunohistochemical Detection of Pax8 and Napsin A in Canine Thyroid Tumours: Comparison with Thyroglobulin, Calcitonin and Thyroid Transcription Factor 1.

Expression of thyroid transcription factor (TTF)-1 corroborates a thyroid origin of neoplasms. Thyroglobulin and calcitonin immunohistochemistry (IHC) can distinguish between a follicular and C-cell origin of thyroid tumours, respectively. Pax8 (expressed by normal canine thyroid follicular cells) and napsin A (expressed mainly by C-cells) labelling was compared with labelling for TTF-1, thyroglobulin and calcitonin in 114 canine proliferative thyroid lesions. All 81 follicular tumours expressed thyroglobulin and were negative for calcitonin; 79/81 (98%) of these tumours expressed TTF-1 and Pax8 and 60/81 (74%) expressed napsin A. All 25 C-cell lesions expressed calcitonin and were negative for expression of thyroglobulin; 22 (88%) were positive for TTF-1, 13 (57%) for Pax8 and 24/24 for napsin A. Six mixed follicular-medullary carcinomas expressed all five markers. Both carcinosarcomas expressed TTF-1 and napsin A, and one each of these tumours expressed thyroglobulin, calcitonin or Pax8. Pax8 expression was also detected in epididymal cells, endometrial cells and vas deferens epithelium, in Sertoli-like ovarian cells, and in some cases of ovarian adenoma, pancreatic carcinoma, renal cell carcinoma and Sertoli cell tumour. Napsin A was also detected in adrenocortical cells, ovarian granulosa cells, epididymal and endometrial cells, as well as in some renal cell carcinomas, pulmonary adenocarcinomas and Sertoli cell tumours. In summary, Pax8 was as sensitive as TTF-1 and slightly less sensitive than thyroglobulin for identification of follicular tumours, but had low sensitivity for C-cell tumours. Napsin A was as sensitive as calcitonin for C-cell neoplasms, but was less sensitive than thyroglobulin for follicular neoplasms. Thus, these markers are sensitive and, except for renal cell carcinoma (for Pax8, napsin A) and pulmonary adenocarcinoma (for napsin A), are specific thyroid tumour markers.

Cerebral Candidal Abscess and Bovine Viral Diarrhoea Virus Infection in an Aborted Bovine Fetus.

Candida species are opportunistic fungi associated with immunosuppression and are the most commonly isolated fungal pathogens from the human central nervous system. Invasive candidiasis is reported uncommonly in animals and there have only been two reports of candidal infection of the brain. This report presents a case of a cerebral candidal abscess in an aborted late-term calf co-infected with bovine viral diarrhoea virus. Candida etchellsii, a species not previously identified as pathogenic, was identified as the causative agent by polymerase chain reaction.

Cartilage boundary lubrication of ovine synovial fluid following anterior cruciate ligament transection: a longitudinal study.

OBJECTIVE: To assess ovine synovial fluid (oSF) from different post-injury time points for (1) proteoglycan-4 (PRG4) and hyaluronan (HA) concentration, (2) HA molecular weight (MW) distribution, (3) cartilage boundary lubrication function, and (4) lubricant composition-function relationships. The association between cartilage boundary lubrication and gross cartilage changes after injury was also examined. METHODS: oSF was collected 2, 4, 10, and 20 weeks post anterior cruciate ligament (ACL) transection in five skeletally mature sheep. PRG4 and HA concentrations were measured using sandwich enzyme-linked immunosorbent assay, and HA MW distribution by agarose gel electrophoresis. Cartilage boundary lubrication of oSF was assessed using a cartilage-cartilage friction test. Gross damage to articular cartilage was also quantified at 20 weeks using modified Drez scoring protocol. RESULTS: Early (2-4 weeks) after ACL injury, PRG4 concentrations were significantly higher (P = 0.045, P = 0.037), and HA concentrations were substantially lower (P = 0.005, P = 0.005) compared to 20 weeks. The HA MW distribution also shifted towards lower ranges in the early post-injury stage. The kinetic friction coefficients were significantly higher 2-4 weeks post injury (P = 0.008 and P = 0.049) compared to 20 weeks. Poor cartilage boundary lubricating ability early after injury was associated with cartilage damage at 20 weeks. CONCLUSION: Altered composition and diminished boundary lubrication of oSF early after ACL transection may pre-dispose the articular cartilage to degenerative changes and initiate osteoarthritis (OA). These observations also provide potential motivation for biotherapeutic interventions at earlier time points post injury.

Immunohistochemical expression of melanocytic antigen PNL2, Melan A, S100, and PGP 9.5 in equine melanocytic neoplasms.

The immunoreactivity of PNL2, Melan A, and protein gene product (PGP) 9.5 was compared with that of S100 protein in 50 formalin-fixed, paraffin-embedded equine melanocytic neoplasms. PNL2, PGP 9.5, and S100 protein were detected in all 50 neoplasms; none expressed Melan A. PNL2 was not expressed in 62 nonmelanocytic tumors (equine sarcoids, schwannomas, carcinomas, sarcomas, endocrine tumors, sex-cord stromal tumors, germ cell tumors, and leukocytic tumors) or in normal tissues other than epidermis. In summary, antibody PNL2 is a sensitive marker of equine melanocytic neoplasms and is more specific than S100 protein or PGP 9.5. In contrast, the monoclonal antibody to Melan A did not react with any of the equine melanomas.

Changes of early post-traumatic osteoarthritis in an ovine model of simulated ACL reconstruction are associated with transient acute post-injury synovial inflammation and tissue catabolism.

The study described here tested the hypothesis that early intra-articular inflammation is associated with the development of post-traumatic osteoarthritis (PTOA) in a sheep model. We extended previously published work in which we investigated joint gross morphology and synovial mRNA expression of inflammatory and catabolic molecules 2 weeks after anatomic Anterior cruciate ligament (ACL) autograft reconstructive surgery (ACL-R). The same variables have been analyzed at 20 weeks post surgery together with new experimental variables at both time points. Animals were sacrificed at 20 weeks post ACL-R surgery and their joints graded for signs of PTOA. Synovial samples were harvested for histological grading plus mRNA and protein analysis for a panel of inflammatory and catabolic molecules. The mRNA expression levels for this panel plus connective tissue matrix turnover molecules were also investigated in cartilage samples. Results of gross morphological assessments at 20 weeks post surgery showed some changes consistent with early OA, but indicated little progression of damage from the 2 week time point. While significant alterations in mRNA levels for synovial inflammatory and catabolic molecules were detected at 2 weeks, values had normalized by 20 weeks. Similarly, all mRNA expression levels for inflammatory and catabolic molecules in articular cartilage had returned to normal levels by 20 weeks post ACL-R surgery. We conclude that synovial inflammatory processes are initiated very early after ACL-R surgery and may instigate events that lead to the gross cartilage and joint abnormalities observed as early as 2 weeks. However, the absence of sustained inflammation and joint instability may prevent OA progression.

Correlation of inflammation with adrenocortical atrophy in canine adrenalitis.

Hypoadrenocorticism or Addison's disease (AD) is a functional disorder in which insufficient mineralocorticoid and glucocorticoid hormones are produced by the adrenal cortex. Human AD is usually attributed to lymphoplasmacytic adrenalitis with autoimmune destruction of the adrenal cortex. Lymphoplasmacytic adrenalitis is also reported in some descriptions of canine AD; however, the histological aspects of adrenalitis or adrenocortical atrophy have not been well characterized because microscopical examination is not required for diagnosis of AD. In this study, sections of adrenal glands from 33 dogs with adrenalitis were compared with those of 37 dogs without adrenal lesions. The affected dogs were classified clinically as having AD (n = 3), being suspected of having AD (n = 17), not having AD (n = 11) or were unclassified (n = 2). The adrenal inflammation was lymphoplasmacytic in 17 dogs, lymphocytic in four, lymphohistiocytic in one, granulomatous in three and neutrophilic in eight cases. Adrenal glands from control dogs lacked leucocyte infiltration and had a cortical to medullary area ratio of 1.1-7.2. All three dogs with AD, 8/17 dogs with suspected AD and 1/11 dogs without AD had a cortical to medullary area ratio <1.1. Because the area ratio was correlated (r = 0.94) with a linear cortical to medullary thickness ratio, a thickness ratio <1.1 could also indicate severe adrenocortical atrophy. Severe adrenocortical atrophy was associated typically with lymphoplasmacytic infiltration and nearly complete loss of cortical cells; however, the zona glomerulosa was partially spared in three dogs with lymphoplasmacytic adrenalitis and severe cortical atrophy. In contrast, non-lymphoid inflammation was generally part of systemic disease, multifocal and was unaccompanied by severe adrenocortical atrophy.

[Digital X-ray: interhospital data transfer by CD-ROM. Prospective data evaluation during the import process]. / Digitales Röntgen: interhospitaler Datentransfer auf CD-ROM. Prospektive Datenevaluation während des Arbeitsprozesses.

BACKGROUND: Increasing numbers of radiological imaging diagnostics are archived in digital form. In addition to the results of diagnostics performed in hospital a growing number of patients present with digital results of outpatient radiological investigations. These digitized images represent a challenge for the internal hospital work flow. The aim of the study was to determine the expenditure for the hospital when dealing with digital outpatient diagnostic results. METHOD: Several parameters were observed and analyzed within the import process of nearly 400 CD-ROMs over a time period of 5 months. Only a negligible number of data on CD-ROMs could not be transferred into the hospital archive (1.5%). The duration of the process depended on the amount of data and the time period. RESULTS: During regular hours the import process took on average 13 min per CD and 19 min per patient while the time increased significantly during on-call duties. This study demonstrates the significance of the import of digital outpatient radiological diagnostic results into the hospital archive which can in particular influence patient treatment.

There is significant load sharing and physical interaction between the anteromedial and posterolateral bundles of the ovine ACL under anterior tibial loads.

INTRODUCTION: The ovine stifle joint is an ideal preclinical model to test the ability of double-bundle reconstruction techniques in providing superior joint stability and less osteoarthritis (OA) compared with single-bundle techniques. However, knowledge of the normal ovine ACL and more specifically the load sharing and physical interaction between the two main bundles of the ovine ACL is currently limited. METHODS: Six ovine stifle joints were tested using a robotic testing system. Each joint was cyclically loaded to 200N in the anterior tibial direction between 30° and 90° flexion and the force-displacement data were recorded for both the intact ACL, and when the anteromedial (AM, n=3) or the posterolateral bundle (PL, n=3) was transected. RESULTS: The load shared by the AM bundle increased from 30° to 75° of flexion at all loading levels (25-200N); whereas, the load shared by the PL bundle decreased between full extension and mid flexion (60°) and then increased again. The load borne by the AM bundle did not change in response to increasing Anterior Tibial Loads (ATL) at each flexion angle, in contrast to the PL bundle (P=0.004). Physical interaction between bundles was greatest at 60° and under 50N ATL. CONCLUSION: These data will help create double-bundle ACL reconstructions in sheep which are functionally similar to intact native ACL. In turn, this model can be used to examine the success of anatomically accurate double-bundle reconstructions to prevent the development of OA. LEVEL OF EVIDENCE: III.

[PHTLS team course: a pilot project. Structured student education in prehospital care of severely injured patients]. / Der PHTLS-TEAM-Kurs ­ ein Pilotprojekt. Strukturierte studentische Ausbildung in der präklinischen Versorgung schwerverletzter Patienten.

BACKGROUND: The training of medical school students at the University of Heidelberg seems to be improvable regarding prehospital trauma treatment compared to an established anaesthesiology-based training for medical emergencies. This study addresses the current situation and possibilities for advancing this training. MATERIAL AND METHODS: A baseline was set by interviews of the medical school students. Based on this the hypothesis was postulated that there is a deficit in the education of the medical school students concerning the training in prehospital trauma treatment. This was proved by questionnaires given to the students in the 7th and 8th semesters at the University of Heidelberg Medical School. The results were evaluated and a possible approach for improvement was developed. RESULTS: A total of 111 questionnaires could be evaluated. It could be shown that the existing education was not effectual and that there is a need for a praxis-orientated 1-day course in prehospital trauma treatment. CONCLUSION: Especially the treatment of multiply injured patients is a challenge for young medical professionals. However, there is a high motivation to learn and train in emergency medicine. The students long for a practical trauma course compared to the advanced medical CPR course provided by the Department of Anaesthesiology of the University of Heidelberg. Those algorithm-based trauma courses do exist with PHTLS® and ATLS®. Based on these courses we developed the PHTLS® TEAM course.

Technical issues in using robots to reproduce joint specific gait.

Reproduction of the in vivo motions of joints has become possible with improvements in robot technology and in vivo measuring techniques. A motion analysis system has been used to measure the motions of the tibia and femur of the ovine stifle joint during normal gait. These in vivo motions are then reproduced with a parallel robot. To ensure that the motion of the joint is accurately reproduced and that the resulting data are reliable, the testing frame, the data acquisition system, and the effects of limitations of the testing platform need to be considered. Of the latter, the stiffness of the robot and the ability of the control system to process sequential points on the path of motion in a timely fashion for repeatable path accuracy are of particular importance. Use of the system developed will lead to a better understanding of the mechanical environment of joints and ligaments in vivo.

New understanding of the complex structure of knee menisci: implications for injury risk and repair potential for athletes.

Menisci help maintain the structural integrity of the knee. However, the poor healing potential of the meniscus following a knee injury can not only end a career in sports but lead to osteoarthritis later in life. Complete understanding of meniscal structure is essential for evaluating its risk for injury and subsequent successful repair. This study used novel approaches to elucidate meniscal architecture. The radial and circumferential collagen fibrils in the meniscus were investigated using novel tissue-preparative techniques for light and electron microscopic studies. The results demonstrate a unique architecture based on differences in the packaging of the fundamental collagen fibrils. For radial arrays, the collagen fibrils are arranged in parallel into ∼10 µm bundles, which associate laterally to form flat sheets of varying dimensions that bifurcate and come together to form a honeycomb network within the body of the meniscus. In contrast, the circumferential arrays display a complex network of collagen fibrils arranged into ∼5 µm bundles. Interestingly, both types of architectural organization of collagen fibrils in meniscus are conserved across mammalian species and are age and sex independent. These findings imply that disruptions in meniscal architecture following an injury contribute to poor prognosis for functional repair.

Cystic pseudotumours in both upper ankle joints in gouty arthritis.

This case demonstrates a yet unreported clinical entity of bilateral tophaceous cystic lesions of the tibiotalar joints of an 37-year-old white male who presents with moderate painful swelling in both upper ankle joints for 2 years. Radiodiagnostic studies show cystic lesions in both upper ankle joints and the right talus considering neoplastic processes in the differential diagnosis. The incisional biopsy reveals chalk-like material of the intraosseous lesions which was pathognomonic for tophaceous gout. Antihyperuricemic medication led to a stagnation of growth of the lesions without a sign of osseous remodeling. However, due to limitation of discomfort, personal preferences and a lack of surgical options conservative treatment was maintained.

Strength of medial structures of the knee joint are decreased by isolated injury to the medial collateral ligament and subsequent joint immobilization.

Past studies of the healing of the medial collateral ligament (MCL) in animal models have been conducted over a variety of healing intervals, some as early as 1 week. One concern with testing at early healing intervals is the difficulty in identifying and isolating the tissues that carry load. The purpose of this study was to determine if isolation of the MCL and healing time are critical factors in the assessment of structural strength in this model. Furthermore, the effect of immobilization on these critical factors was investigated. Our approach was to calculate the load-sharing ratio between the MCL and the MCL plus capsule. A 4 mm gap was created in the midsubstance of both hindlimb MCLs of 52 female New Zealand White rabbits (n=104). Of these, 29 rabbits had their right hindlimb pin immobilized (immobilized group), leaving the left hindlimb non-immobilized. Testing was performed at 3 (n=12), 6 (n=22), and 14 (n=24) weeks. The remaining 23 rabbits, which had both limbs non-immobilized (non-immobilized group), were tested at 3 (n=10), 6 (n=12), 14 (n=12), and 40 (n=12) weeks. For both groups, half of the specimens at each healing interval were used to test the MCL alone and half to test the MCL plus capsule, except for 3 week immobilized joints where only the MCL plus capsule was tested. Additionally, MCL (n=12), MCL plus capsule (n=6), and capsule alone (n=5) were tested from normal animals. The load-sharing ratio at MCL failure for the normal joint was 89%, suggesting an MCL-dominated response. For the non-immobilized group, the load-sharing ratio was 24% at 3 weeks of healing, suggesting a capsule-dominated response. At and after 6 weeks of healing, an MCL-dominated response was observed, with the ratio being 68% or greater. Thus, at less than 6 weeks of healing, the structural strength capabilities of the joint may be better represented by the medial structures rather than the isolated MCL. Immobilization delayed the transition from a capsule-dominated response to an MCL-dominated response in this model.

Biomechanical study using fuzzy systems to quantify collagen fiber recruitment and predict creep of the rabbit medial collateral ligament.

In normal daily activities, ligaments are subjected to repeated loads, and respond to this environment with creep and fatigue. While progressive recruitment of the collagen fibers is responsible for the toe region of the ligament stress-strain curve, recruitment also represents an elegant feature to help ligaments resist creep. The use of artificial intelligence techniques in computational modeling allows a large number of parameters and their interactions to be incorporated beyond the capacity of classical mathematical models. The objective of the work described here is to demonstrate a tool for modeling creep of the rabbit medial collateral ligament that can incorporate the different parameters while quantifying the effect of collagen fiber recruitment during creep. An intelligent algorithm was developed to predict ligament creep. The modeling is performed in two steps: first, the ill-defined fiber recruitment is quantified using the fuzzy logic. Second, this fiber recruitment is incorporated along with creep stress and creep time to model creep using an adaptive neurofuzzy inference system. The model was trained and tested using an experimental database including creep tests and crimp image analysis. The model confirms that quantification of fiber recruitment is important for accurate prediction of ligament creep behavior at physiological loads.

Ligament structure, physiology and function.

Ligaments are specialized connective tissues with very interesting biomechanical properties. They have the ability to adapt to the complex functions that each are required to perform. While ligaments were once thought to be inert, they are in fact responsive to many local and systemic factors that influence their function within the organism. Injury to a ligament results in a drastic change in its structure and physiology and creates a situation where ligament function is restored by the formation of scar tissue that is biologically and biomechanically inferior to the tissue it replaces. This article will briefly review the basic structure, physiology and function of normal versus healing knee ligaments, referring specifically to what is known about two of the most extensively studied and clinically relevant knee ligaments, the anterior cruciate (ACL) and medial collateral (MCL) ligaments of the knee. Those readers wishing for more comprehensive sources of information on ligament biology and biomechanics are referred to many excellent reviews on these topics.