Classification and management strategies for paediatric chronic nonbacterial osteomyelitis and chronic recurrent multifocal osteomyelitis

INTRODUCTION

Chronic non-bacterial osteomyelitis (CNO) is an autoinflammatory bone disease that most commonly affects children and adolescents causing significant pain and damage to bones. The absence of diagnostic criteria and biomarkers, an incomplete understanding of the molecular pathophysiology, and lack of evidence from randomized and controlled trials make the diagnosis and care challenging.

AREAS COVERED

This review provides an overview of the clinical and epidemiological features of CNO and displays diagnostic challenges and how they can be addressed following strategies used internationally and by the authors. It summarizes the molecular pathophysiology, including pathological activation of the NLRP3 inflammasome and IL-1 secretion, and how these observations can inform future treatment strategies. Finally, it provides a summary of ongoing initiatives aiming at classification criteria (ACR/EULAR) and outcome measures (OMERACT) that will enable the generation of evidence through clinical trials.

EXPERT OPINION

Scientific efforts have linked molecular mechanisms to cytokine dysregulation in CNO, thereby delivering arguments for cytokine blocking strategies. Recent and ongoing collaborative international efforts are providing the basis to move toward clinical trials and target directed treatments for CNO that find approval by regulatory agencies.

The cervical spine in paediatric radiology

Accurate radiological assessment of the cervical spine is vital in the management of the child presenting with trauma. Compared to an adult's spine, the significant differences in the developmental anatomy (variants or synchondrosis), biomechanics and fracture patterns in the paediatric cervical spine makes assessment difficult, even for experienced radiologists. This review discusses the unique biomechanical factors, developmental anatomy, patterns of injury and imaging strategy in the paediatric population.

Rate and severity of radiological features of physical abuse in children during the first UK-wide COVID-19 enforced national lockdown

Rate and severity of radiological features of physical abuse in children during the first UK-wide COVID-19 enforced national lockdown.

OBJECTIVE

To assess the number, type and outcome of radiological investigations for children presenting to hospital with suspected physical abuse (SPA; including abusive head trauma) during the first national COVID-19 enforced lockdown compared with the prelockdown period.

DESIGN

Multicentre, retrospective, observational, interrupted time series analysis.

SETTING

Eight secondary/tertiary paediatric centres between January 2018 and July 2020 inclusive.

PARTICIPANTS

1587 hospital assessed children undergoing radiographic skeletal surveys (SkS) and head CT imaging performed for SPA/child protection concerns.

MAIN OUTCOME MEASURES

Incidence and severity of fractures identified on SkS; head injury (composed of incidence rates and ratios of skull fracture, intracranial haemorrhage (ICH) and hypoxic ischaemic injury (HII)) on head CT imaging; and ratio of antemortem and postmortem SkS.

RESULTS

1587 SkS were performed: 1282 (81%) antemortem, 762 (48%) male, and positive findings in 582 (37%). Median patient age was 6 months. There were 1.7 fractures/child prelockdown versus 1.1 fractures/child during lockdown. There was no difference between positive/negative SkS rates, the absolute ratio of antemortem/postmortem SkS or absolute numbers of head injury occurring between January 2018 and February 2020 and the lockdown period April-July 2020. Likewise, prelockdown incidence and rates of skull fracture 30/244 (12%), ICH 28/220 (13%) and HIE 10/205 (5%) were similar to lockdown, 142/1304 (11%), 171/1152 (15%) and 68/1089 (6%), respectively.

CONCLUSION

The first UK COVID-19 lockdown did not lead to an increase in either the number of antemortem or postmortem radiological investigations performed for SPA, or the number or severity of fractures and intracranial injuries identified by these investigations.

Revision of 116 orthognathic surgery patients operated on with the high-oblique sagittal osteotomy (HOSO): a retrospective case series (PROCESS-compliant article)

BACKGROUND

The high-oblique sagittal osteotomy (HOSO) is an alternative to a bilateral sagittal split osteotomy (BSSO). Due to its novelty, there are no long-term studies which have focused on describing the incidence and type of complications encountered in the post-operative follow-up. The aim of this retrospective study is to analyze patients operated on with this surgical technique and the post-operative complications encountered.

PATIENT AND METHODS

The electronic medical records of all patients treated with orthognathic surgery at the Department of Oral, Maxillofacial and Facial Plastic Surgery, University Hospital Frankfurt, Goethe University, Frankfurt, Germany, between the years 2009 and 2016 were retrospectively reviewed.

RESULTS

A total of 116 patients fulfilled the inclusion criteria. The cases operated on with the standard osteosynthesis (X, Y, and straight) showed a complication rate of 36.37% (n = 4/11). The cases operated on with the HOSO-dedicated plates (HOSO-DP) showed, in total, a complication rate of 6.67% (n = 7/105). The most common post-operative complication resulting from both fixation methods was a reduction in mouth opening and TMJ pain for 4.3%. During the first years of performing the surgery (2009-211), a variety of standard plates had material failure causing non-union or pseudarthrosis. No cases of material failure were observed in the cases operated on with the HOSO-DP. The statistical results showed a highly significant dependence of a reduction in OP-time over the years, when the HOSO was performed without additional procedures (R² > 0.83, P < 0.0015).

CONCLUSION

The rate of complications in the HOSO were shown to be comparable to the rate of complications from the BSSO reported in the literature. Moreover, the use of the ramus dedicated plate appears to provide enough stability to the bone segments, making the surgery safer.

CLINICAL RELEVANCE

The HOSO needs to be considered by surgeons as an alternative to BSSO. Once the use of the HOSO-DP was established, the rate of complications and the operation time reduced considerably.

Skeletal abnormalities secondary to antenatal etidronate treatment for suspected generalised arterial calcification of infancy

Background

Generalised arterial calcification of infancy (GACI) is a rare disorder characterised by the deposition of hydroxyapatite crystals within the vessel walls. It is associated with a high mortality rate. Bisphosphonates have been used with some success in the treatment of GACI. However, there is a paucity of data on the antenatal use of bisphosphonates for GACI. In this paper, we report development of the skeletal changes suggestive of hypophosphatasia (HPP) in an infant with GACI, whose mother was treated with etidronate during pregnancy.

Case report

A Caucasian infant boy had a suspected antenatal diagnosis of GACI based on the findings suggestive of calcification of the annulus of the tricuspid valve and wall of the right ventricular (RV) outflow tract and main pulmonary artery on foetal echocardiography and the genetic analysis which showed a pathogenic heterozygous mutation in ABCC6. Based on these findings, mother was started on etidronate treatment from 26 weeks of gestation. A healthy male baby was delivered at 38 weeks of gestation. Initial postnatal echocardiogram on day 1 of life was normal with good biventricular function; subtle changes suggestive of microcalcifications were detected on the CT angiography. Serum calcium, phosphate, alkaline phosphatase and renal profile were normal. Further, the serum inorganic pyrophosphate (PPi) level was significantly low. Skeletal changes suggestive of HPP were seen on the radiographs. The baby developed cardiac dysfunction on day 4 of life with evidence of ischaemic changes on electrocardiogram (ECG).Treatment with etidronate was started in view of probable evolving coronary calcifications. Despite treatment with cardiac supportive measures and bisphosphonate, he succumbed to death in the third week of life.

Discussion

We believe, this is the first report of skeletal changes suggestive of HPP, arising secondary to antenatal etidronate (first generation bisphosphonate) used for the treatment of suspected GACI due to a heterozygous ABCC6 mutation.

Short-term outcome of surgical arthrodiastasis of the ankle with Ilizarov frame in a cohort of children and young people with juvenile idiopathic arthritis

Objectives

Despite medical advances, life-changing articular damage may still occur in patients with JIA. We report a cohort with destructive arthropathy of the ankle treated by surgical arthrodiastasis.

Methods

Eight patients (nine ankles) received arthrodiastasis by means of an Ilizarov frame between 2009 and 2013. Patient- and clinician-reported outcome measures were collated prospectively, with retrospective analysis of demographics, disease and pre-surgical treatment.

Results

Pre-surgery, all patients received IA CS (mean 0.8 injections/year) and MTX (mean diagnosis to treatment 3.8 years; two of eight started within 3 months). Seven of eight patients received biologic drugs. Pain scores improved by 56 and 29% (P < 0.005) at 6 and 12 months post-frame removal. American Academy Orthopaedic Foot and Ankle Society ankle–hindfoot scale, Oxford Ankle Foot Questionnaire-Child and Oxford Ankle Foot Questionnaire-Parent scores improved by 171, 62 and 80%, respectively (P < 0.005) at 12 months post-frame removal. Patients remained satisfied with surgical treatment for a mean of 13.3 months. There was transient pin site infection in three patients, and all patients had radiological improvement in joint space.

Conclusion

Arthrodiastasis with an Ilizarov frame is a safe, well-tolerated technique that should be considered as a short-term joint-preserving procedure to improve pain and function when damage has occurred. Delays to systemic medical treatment in this cohort would be considered out-with standard modern practice but, although less prevalent, destructive ankle arthropathy continues to occur in JIA, and we believe this study to be relevant. The ankle is particularly susceptible to damage and, even if localized, should be treated early and aggressively with DMARDs and rapid progression to biologic therapies.

Levelof evidence

Level IV.

Shortage of paediatric radiologists acting as an expert witness: position statement from the British Society of Paediatric Radiology (BSPR) National Working Group on Imaging in Suspected Physical Abuse (SPA)

One of the most challenging areas of radiological imaging in children is the diagnosis of physical abuse. There is a dearth of paediatric radiologists willing to act as expert witnesses, particularly in the family courts. There are a number of reasons why radiologists may not be interested or willing to put themselves forward to work as expert witnesses in this field. A group of imaging experts recently formed the "British Society of Paediatric Radiology (BSPR) Working Group on Imaging in Suspected Physical Abuse (SPA)". The group comprises radiologists and neuroradiologists with current or previous experience of providing expert witness reports to the court in cases of SPA. The group met in January 2019 to explore pragmatic solutions to the chronic inefficiencies in both medical and legal practices and the challenges that arise from working in a legal arena with different structures, goals, and assessment criteria. Key issues concerned organisational inefficiencies, variable support from National Health Service Trusts and the Royal College of Radiologists to conduct this work, and the risk/benefit of involvement. This work is important for the patient, parents, and society in general, and highly rewarding for clinical practitioners who are involved, but there are several issues with current practices that discourage active participation. With several members of the group either retired or close to retirement, the shortage of experts is becoming a pressing issue within the UK, which requires an engaged multidisciplinary group to come up with creative solutions. Here, the group provide a consensus opinion highlighting the current barriers and potential facilitators to increasing the number of radiologists willing to provide opinions to the court.

Introduction of a novel magnetic resonance imaging-based scoring system for assessing disease activity in children with juvenile dermatomyositis

Objectives

We aimed to develop and assess the reliability of a novel MRI-based scoring system for reporting the severity of MRI findings in children with suspected JDM.

Methods

Nine consultant paediatric radiologists independently assessed and scored 40 axial and 30 coronal thigh MR images of children with suspected JDM on two occasions using the juvenile dermatomyositis magnetic resonance Imaging Score (JIS). JIS was calculated for both reads for each plane and each limb, with possible scores ranging from 0 (normal) to 100 (severe). Inter- and intraobserver agreement was calculated using the intraclass correlation coefficient (ICC) and two- and one-way random effects models, respectively. Bland-Altman plots of the difference in JIS against the average JIS were also produced for each rater.

Results

Overall, the interobserver reliability and agreement was good—for axial images, JIS ranged from 46.8 to 61.0 [ICC = 0.88 (95% CI: 0.82, 0.92)] for the left limb and 47.9–61.4 [ICC = 0.87 (95% CI: 0.81, 0.92)] for the right limb. For coronal images, JIS ranged from 56.7 to 65.1 [ICC = 0.90 (95% CI: 0.85, 0.95)] for the left limb and 55.7 to 66.8 [ICC = 0.90 (95% CI: 0.84, 0.94)] for the right limb. The intraobserver reliability and agreement was good, with ICC ranging from 0.90 to 0.94.

Conclusion

JIS is a semi-objective scoring system with potential to serve as a reliable biomarker of disease severity and response to therapeutic interventions in children with JDM.

Soft-tissue evidence of head injury in infants and young children: is CT head examination justified?

AIM

To determine whether it is justified to undertake a computed tomography (CT) examination of the head in children under 1 year of age who present with a bruise, swelling, or laceration of >5 cm following head injury in children presenting to a paediatric accident and emergency (A&E) department in the northwest of England. Further aims were to determine whether there was any justification for performing a CT head examination for children with soft-tissue injuries measuring <5 cm, or for children >1 year with evidence of soft-tissue injury, but without any other concerning feature.

MATERIALS AND METHODS

Children <3 years of age presenting with soft-tissue evidence of head injury between May 2011 and Oct 2014 and who subsequently underwent head CT were retrospectively identified from radiology requests. The CT images and clinical notes were used to identify those with skull fracture or intracranial haemorrhage and to determine whether the child was subsequently admitted or discharged from A&E.

RESULTS

Eighty-five CT head examinations met the criteria for inclusion. Of these, 45 examinations demonstrated skull fractures and four examinations identified intracranial haemorrhage. Thirty-eight requests included soft-tissue evidence of head injury as the sole reason indicated for CT head examination. Of these, 22 examinations demonstrated skull fractures and one examination identified intracranial haemorrhage.

CONCLUSION

Soft-tissue evidence of head injury as the sole reason for CT head examination appears to be justified in the present patient population. Furthermore, this study suggests that CT head examination should also be considered for children with soft-tissue injuries of <5 cm and for children aged between 1 and 3 years if identification of a skull fracture would alter the child's management.

Computer-assisted pre- and postoperative evaluation of surgically assisted rapid maxillary expansion

OBJECTIVE

Computer-assisted methods were used to evaluate different variants of surgically assisted rapid maxillary expansion (SARME) in terms of bone repositioning, new bone formation in the osteotomy gap, and bone quality before and after surgery.

MATERIALS AND METHODS

Twenty-nine patients (18 male, 11 female) with a mean age of 29 years (16 to 44 years) were included in the study. Surgically assisted rapid maxillary expansion with Le Fort I osteotomy was performed in all patients studied. High-resolution computed tomography (CT) was carried out directly before and 6 to 8 weeks after surgery. After registration of the preoperative CT data on the postoperative data, 3D models were constructed and superimposed. New bone formation in the osteotomy gap was visualized by means of a visualization procedure developed specifically for this purpose. Bone quality was analyzed by dividing the models into different anatomical segments. A qualitative comparison of the data was accomplished using a direct volume rendering procedure with a special transfer function. A quantitative comparison was carried out based on the pre- and postoperative histograms of each region.

RESULTS

Maxillary widening was confirmed in all patients by computer-assisted analysis. Four patients exhibited significant maxillary asymmetry after surgery. New bone formation within the osteotomy gap was irregular along the osteotomy lines but often symmetrical on both sides. The more symmetrical the osteotomy, the more symmetrical the new bone formation proved to be. In all but two cases, the postoperative qualitative and quantitative analyses showed a significant decrease in Hounsfield units, particularly in the vestibular bone.

CONCLUSION

The differences in new bone formation in the osteotomy gap suggest that the type of surgical technique and distractor used influence the outcome. Our results indicate that SAME results in a decrease in bone quality, particularly in the vestibular bone. Computer-assisted analysis clearly results in an information gain.

Finite element simulation of skeletal muscular structures obtained from images of histological serial sections

In this study, we present a method for the three-dimensional reconstruction of objects obtained from histological serial sections (exemplified by those of a pennate striated skeletal muscle) and its application to the finite element method. A hyperelastic material model is used for modeling biological soft tissue. The reconstruction process relies on the direct construction of a volumetric mesh using an octree approach which leads to a stable finite element method. Stability can be expressed in the spectral matrix condition number. To visualize stress patterns within the underlying anatomy the simulation results are projected onto images of the histological scenario.

Phaeochromocytoma in children

Phaeochromocytoma is a rare clinical entity in children. Contrary to traditional teaching, which suggested that 10% of phaeochromocytomas are "familial", a germline mutation has been identified in up to 59% (27/48) of apparently sporadic phaeochromocytomas presenting at 18 years or younger and in 70% of those presenting before 10 years of age. The inherited predisposition may be attributable to a germline mutation in the Von Hippel-Lindau gene, the genes encoding the subunits B and D of succinate dehydrogenase, the RET proto-oncogene predisposing to multiple endocrine neoplasia type 2, or the neurofibromatosis type 1 gene. Of these, the Von Hippel-Lindau gene is the most commonly mutated gene in children presenting with a phaeochromocytoma. Genetic counselling is recommended before gene testing and investigation of the wider family. This review provides guidance on the aetiology, investigation, management, histopathology, genetics and follow-up of children with a phaeochromocytoma.

[Ultrasonic bone cutting in oral surgery: a review of 60 cases]

PURPOSE

Surgical reconstruction of bony defects in the oral cavity can often be challenging since thin and fragile bony structures are especially prone to fracture cased by bulky cutting tips or the application of significant pressure by conventional mechanical instruments. The risk of accidental damage to adjacent soft tissue structures, such as nerves, by a dental drill or saw is also extremely high. The use of modulated ultrasound (piezosurgery) makes it possible to overcome such complications as a result of the precise and minimally invasive surgery technique which is limited to mineralized hard tissue.

MATERIALS AND METHODS

In 60 patients (38 male, 22 female) a piezosurgery device was used for different bone augmentation procedures before dental implant placement. The instrument uses modulated ultrasound (25 - 30 kHz) and the amplitude of the working tip ranges from 60 mum to 200 mum. The device was employed for sinus floor elevation (25), alveolar ridge augmentation using an autogenous block graft (25), alveolar ridge splitting (5) or lateralization of the alveolar nerve (5). Physiological sodium chloride was used as a cooling solution. For all osteotomies mode boosted burst c and pump 5 were used.

RESULTS

Piezoelectric osteotomy permitted micrometric selective cutting and a clear surgical site due to the cavitation effect created by the cooling solution and the oscillating tip. No excessive bleeding was encountered. The risk of accidental soft tissue harm, such as perforating the sinus membrane or damaging adjacent nerves, was definitely lower than in the case of a conventional bur. No serious complications were encountered in the postoperative wound healing process after 2, 14, 30 and 90 days. However, the surgical procedures were time-consuming.

CONCLUSION

Piezosurgery is an advantageous osteotomy technique for delicate structures in the oral and maxillofacial region. With respect to osteotomies of thin and fragile bones, the application of ultrasound is superior to other mechanical instruments because of the extremely precise and virtually arbitrary cut geometries, easy handling, efficient bone ablation and minimal accidental damage to adjacent soft tissue structures.

Histopathologic findings after treatment with different oxidosqualene cyclase (OSC) inhibitors in hamsters and dogs

In order to investigate the toxicity of oxidosqualene cyclase (OSC) inhibitors, hamsters and dogs were treated up to 13 weeks with three different agents of this compound class. Subacute treatment (< or = 4 weeks) of hamsters and dogs with OSC inhibitors produced a similar spectrum of histopathologic lesions, which have previously been described for compounds of this pharmacological class. In the hamster, other lesions were produced only after subchronic treatment (13 weeks). After subacute treatment, histopathologic findings were observed in the eye, skin and forestomach. Lesions in the eye were characterized as proliferation, swelling and degeneration of lens fiber cells. This finding was considered to be an early stage in cataract development. In the skin and forestomach, squamous cell hyperplasia and hyperkeratosis accompanied by a mixed inflammation was observed. After subchronic treatment of hamsters, histopathologic findings were observed in the eye, skin, forestomach, testes, epididymides, prostate gland, seminal vesicles and long bones. Lesions in the eye were characterized as cataracts. Squamous cell hyperplasia accompanied by a diffuse hyperkeratosis and a mixed inflammation was seen in the skin and forestomach epithelium. In addition, testes lesions were characterized as testicular atrophy, generalized germ cell depletion, germ cell degeneration and tubular collapse. Atrophy, oligospermia and lumenal germ cells/cell debris were found in the epididymides. The prostate gland and seminal vesicles were decreased in size (atrophy). The bone lesions were characterized as a failure of enchondral ossification causing variable widening of the growth plate and a failure to form primary bone trabecula (lesions resemble those found in rickets). To our knowledge, this is the first study describing the toxicity of OSC inhibitors after subchronic treatment in hamsters and dogs. As all adverse effects described in this report are considered to be due to an exaggeration of the desired biochemical mechanism of action at high dose levels, a decrease of the systemic exposure by the use of more hepatoselective OSC inhibitors is expected to reduce the probability of these adverse effects in humans.

Sonography of the temporomandibular joint from 60 examinations and comparison with MRI and axiography

BACKGROUND AND OBJECTIVE

Establishing a diagnosis of temporomandibular joint disorder is mainly based on clinical assessment, functional examination, nuclear magnetic resonance imaging (MRI) and axiography. Sonographic examination was compared with MRI and axiography in assessing temporomandibular joint (TMJ) function in 55 patients.

PATIENTS AND METHODS

Fifty-five patients with different TMJ problems were examined clinically, by means of axiography, sonography and some also by MRI. The range of motion was measured by sonography and axiography and the results compared using Student's t-test. Anatomical details diagnostic for disc-displacement were tested by sonography and MRI.

RESULTS

The average time required for sonography was 2 min and for axiography 20 min. The mean measurement differences for condylar movement in maximal mouth opening was 1.7 mm, for protrusion 1.6 mm and for mediotrusion 2.5 mm. The range of condylar movement as measured by sonography and axiography coincided for opening and for protrusion (statistically significant). No significance was found for lateral excursions. The concordance in diagnosis of disc dislocation, hypermobility and impaired range of motion when comparing ultrasound with MRI was 83%. All sonographic examinations were performed by one person only. Sixty repeat examinations in patients produced no complaints and showed an absolute range of difference of 0.6 mm, with a relative range of 7%. Student's t-test was significant (p<0.05) (two repetitive measurements).

CONCLUSION

Sonography proved to be a fast and reliable method for evaluating the range of movement of the TMJ. The lateral joint capsule, lateral disc, and upper condyle could be demonstrated. Pathological processes such as anterior or lateral disc displacement, disc perforation, seroma following contusion, capsular fibrosis, crystalline structures in the synovia and fracture dislocation of the condyle could be diagnosed with considerable reliability when compared with MRI. However, the medial aspect of the joint, medial disc dislocation and the angulation of the condylar slope could not be seen.

The dorsal fascia dentata as a probe of fixation quality in the rodent brain

In microscopic sections of the rodent brain the dorsal fascia dentata frequently shows perineuronal swelling and neuronal swelling and shrinkage. Factors influencing the occurrence of such changes, which may mimic excitotoxic effects, have been examined using various schedules of anaesthesia and perfusion fixation. Laboratory mice anaesthetized with a low dose of sodium pentobarbital manifested prolonged excitation in comparison to those anaesthetized with a high dose: the occurrence of tremor and convulsions, however, was not related to the morphological changes in the fascia dentata. The changes were diminished by increasing the perfusion pressure (from 80 to 120 mmHg), by reducing the duration of the wash-out period with buffer (from 45 to 15 seconds) and by prolonging the perfusion time (from 7 to 15 minutes). They were abolished when 5% solution of glutaraldehyde was used instead of a 2.5%. The results show that the quality of brain fixation may be best assessed according to the morphology of the dorsal fascia dentata, and that the occurrence of acute swelling and shrinkage in this area should not be mistaken for pathological changes.

[Radiologic determination of bone screw exit site on the femoral condyle. A method of exact imaging and length determination of internal fixation devices (screws, K-wires) in metaphyses of larger tubular bones exemplified by the distal femur]

Distal femur imaging (A-P and lateral X-rays) after internal fixation often give only poor visualization of the exact position. A model with two anteriorly positioned cortex screws was used to show that an additional oblique X-ray, or fluoroscopy of the tip of the screw, allows much more exact determination of its length, so that it can be changed if necessary. This method is considered by the authors as a simple check of screw length measurement in "foyer fermée" procedures.

Delayed epidural hematoma

A case of delayed epidural hematoma is described who had an initial computerized tomography (CT) scan reported as normal. Repeat CT scan at 48 h demonstrated a right temporal epidural hematoma. A skull fracture was not observed radiographically or at surgery. The world literature is reviewed and the criteria for repeat CT scanning is discussed.

Contribution of immunohistochemistry toward the diagnosis of tumors of laboratory rats

A polyclonal antibody detecting S-100 protein (S-100) and a monoclonal antibody demonstrating epithelial cell (Lu-5) were used in addition to routine, hematoxylin-eosin stain to improve the identification of tumors of neural or epithelial origin diagnosed in conventionally treated tissue from rat bioassays. Among 108 lesions tested for S-100, 51 reacted positively; they included benign and malignant schwannoma, endomyocardial disease, some cases of benign and malignant thymoma, and renal tubular adenoma. S-100 protein is considered particularly useful for discriminating of neoplasms of Schwann cell origin from mesenchymal tumors. 31 of 51 lesions tested for Lu-5 reacted positively: they comprised adenoma, carcinoma, benign and malignant thymoma and atriocaval node tumor of the heart. Lu-5 was especially useful to distinguish epithelial from mesenchymal neoplasms and was capable of identifying epithelial elements in lymphocyte-rich thymomas as well as in dedifferentiated or autolytic tumors. The binding of both antibodies in neoplastic tissue was compared with a complete set of anatomically normal rat tissues.

Rat endomyocardial disease: a neural origin?

Of 58 cardiac lesions in rats from a Sprague-Dawley-derived strain, representing different stages of endomyocardial disease including 10 cases progressing to tumors, most stained positively for S-100 protein, while duplicate sections of selected cases also reacted positively for neuron-specific enolase. The results demonstrate the probable neural origin of these lesions.

[Causes of death and disease in cats based on 1969-1982 autopsy statistics]

The post mortem investigation of 4561 cats during 14 years is analysed according to the diagnosis. The age of the cats necropsied ranged from 1 day to 22 years, with an average of 3,3 years. The sex distribution was about 1:1. The most common disease is feline panleucopenia (16,6%) followed by traumata (11,5%), disorders of the urinary tract (7,0%), feline infectious peritonitis (6,0%), disorders of the circulatory system (5,8%), and diseases of the digestive tract (5,3%). The majority of kittens died of virus diseases, mainly feline panleucopenia. Feline leucosis is found among all groups of age. In middle aged animals (5-10 years) feline leucosis and diseases of the urinary tract are the main causes of death. Cats older than eight years show a high rate of tumor incidence, especially those of non lymphatic origin. Among siamese cats congestive cardiomyopathy is very common. A sexual disposition is notable for the feline urologic syndrome, occurring predominantly in male individuals.