Skeletal pathology and bone mineral density changes in wild muskrats (Ondatra zibethicus) and red squirrels (Tamiasciurus hudsonicus) inhabiting arsenic polluted areas of Yellowknife, Northwest Territories (Canada): A radiographic densitometry study.

The City of Yellowknife is a known hotspot of arsenic contamination and there is a growing body of evidence suggesting that local wildlife in the vicinity of the abandoned Giant Mine site may be at risk of decreased bone mineralization and various bone disorders. The purpose of this study was to preliminarily measure bone mineral density (BMD) changes and investigate the incidence, pattern, and severity of bone lesions in wild muskrats and red squirrels breeding in three (3) catchment areas at different distances from the Giant Mine Site in Yellowknife, Northwest Territories (Canada): ~2 km (location 1), ~18 km (location 2), and ~40-100 km (location 3). Full femoral bones of 15 muskrats and 15 red squirrels were collected from the three sampling locations (5 from each location) and subjected to radiographic analysis and densitometric measurements. The patterns and severities of bone lesions, including changes in bone mineral density, were evaluated and compared between groups. As levels were significantly higher in the bones of muskrats caught from location 1 and 2, relative to location 3. Further, As and Cd levels were significantly higher in the bones of squirrels caught from locations 1 and 2 relative to squirrels caught from location 3. The preliminary results from bones revealed that radiographic abnormalities such as bone rarefaction, osteopenia, and thinning of the femoral shafts with significant ossific cystic lesions and bowing were the most common skeletal pathologies found in bones of red squirrels from the three locations. Radiographic appearances of massive sclerosis and dysplasia, including severe osteocondensation and osteopathia striata-like abnormalities, were found in the bones of muskrats from all the sampling locations. Densitometric evaluation showed no significant differences between the three locations in the bone parameters measured. However, there was a statistically significant correlation between As content in the bones of muskrats and percent fat content in the femur samples, which suggests that accumulation of As could have been a causal factor for a change in percent fat in femurs of muskrats.

Chronic arsenicosis and cadmium exposure in wild snowshoe hares (Lepus americanus) breeding near Yellowknife, Northwest Territories (Canada), part 2: Manifestation of bone abnormalities and osteoporosis.

Various bone abnormalities, including osteoporosis, have been associated with chronic arsenic and cadmium exposure in experimental animal models, but information regarding the bone pathology of wild population of small mammals breeding in contaminated environment is limited. This present study was conducted to comparatively assess the prevalence and pattern of skeletal abnormalities in free ranging snowshoe hares inhabiting an area heavily contaminated by arsenic and other trace metals, near the vicinity of the abandoned Giant mine, and in a reference location approximately 20km from the city of Yellowknife, Northwest Territories, Canada. The femur and vertebrae of snowshoe hares from the mine area and reference location were subjected to bone densitometry examination and biomechanical testing using dual energy X-ray absorptiometry (DXA) and 3-point bending test. t-test results indicated that femoral densitometry parameters such as bone mineral density (BMD) (p=0.5), bone mineral content (BMC) (p=0.675), bone area (BA) (p=0.978) and tissue area (TA) (p=0.549) were not significantly different between locations. All densitometry parameters of the vertebrae (BMD, BA and TA) differed between locations (p<0.05), except for BMC (p=0.951) which showed no significant difference between the two locations. Vertebrae from the mine area also showed relatively lower BA and TA compared to the reference location. A constellation of skeletal abnormalities were also observed along the axial and appendicular bones respectively. Specifically, growth defects, osteoporosis, cortical fractures, sclerosis, and cyst like changes were commonly observed in the femurs and vertebrae of hares from both locations. With respect to biomechanical properties, only bone stiffness and peak load tended to be relatively reduced in specimens from the mine area, whereas work to failure was notably increased in specimens from the reference site compared to those from the mine area. Taken together, the results of this preliminary study suggest that chronic concomitant exposure to arsenic and cadmium may be involved in the etiology of various bone abnormalities, including osteoporosis in wild population of snowshoe hares from the Yellowknife area. The result presented in this study represent the first evaluation of osteological effects in free-ranging furbearers (snowshoe hares) diagnosed with arsenicosis, and concomitantly exposed to environmental levels of cadmium.

[Hip dysplasia and spinal osteochondritis (Scheuermann's disease) in a girl with type II manifesting collagenopathy]. / Hüftdysplasie und Morbus Scheuermann bei einem Mädchen mit Typ-II-Kollagenopathie.

OBJECTIVES: This paper describes the natural course of irritable hip pain associated with spinal rigidity and pain in the thoracic region with subsequent development of mild kyphosis in a girl with a mutation in the collagen 2 alpha 1 gene (type II collagenopathy). METHODS: Phenotypic and genotypic characterization was carried out in a 14-year-old girl to identify the underlying pathology of severe irritable hip pain associated with thoracic spinal rigidity and pain. Detailed clinical examination, skeletal survey and genetic testing were performed accordingly. Bernese periacetabular osteotomy was used to alleviate pain and to improve the anatomical correlation of the acetabular and femoral heads. RESULTS: Short stature associated with acetabulo-femoral dysplasia, spinal osteochondritis (Scheuermann's disease) and mild thoracic kyphosis were the most prominent abnormalities. Genetic analysis showed a heterozygous mutation in the collagen type II gene (COL2A1-c.1636G>A, p. G546S). A Bernese periacetabular osteotomy was performed to improve the clinical status of the patient. There was significant improvement in the extrusion index, the acetabular index and the lateral center-edge angle. CONCLUSIONS: Hip dysplasia and Scheuermann's osteochondritis have never been reported in connection with a mutation in COL2A1 (collagenopathy type II). Awareness is needed for careful phenotypic and genotypic characterization in patients with irritable hip pain and spinal stiffness.

Evidence of reduced bone turnover and disturbed mineralization process in a boy with Stickler syndrome.

We describe a tall-statured 14-year-old boy who illustrated the full phenotypic and radiographic features of Stickler syndrome type I. A bone biopsy showed evidence of reduced bone mass and bone turnover, such as reduced BV/TV (-43%), TbTh (-29%), and OS/BS (-48%), Ob.S/BS (-27%), and Oc/BS (-47%) compared to "age-matched" controls. Moreover, there was evidence that the mineralization process was severely disturbed. Quantitative backscattered electron imaging revealed that the bone mineralization density distribution (BMDD) of cancellous (Cn) as well as cortical (Ct) bone was shifted toward lower mineralization compared to a young control reference cohort. BMDD parameters of mean degree of mineralization, Cn Ca (-9.8%) and Ct Ca (-18.0%), were dramatically decreased. To the best of our knowledge this is the first clinical report describing bone biopsy findings in a boy with Stickler syndrome. Such a severe undermineralization of bone matrix might essentially contribute to the compromised mechanical competence of the skeleton found in this patient.

Sirenomelia (symelia apus) with Potter's syndrome in connection with gestational diabetes mellitus: a case report and literature review.

We report one case of a fetus of sirenomelia sequence with Potters syndrome which showed oligohydramnios and symelia apus. The infant showed absent urinary tract and external genitalia, the legs were fused by skin and had separate bones associated with Potter's syndrome. The mother had a history of gestational diabetes mellitus.

Robinow syndrome: report of two cases and review of the literature.

We report two patients with Robinow syndrome, review the published literature and stress the importance and limitations of radiographic examination in the diagnosis of this disorder, which shows extreme clinical and radiographic variability. The radiographic differential diagnosis of Robinow syndrome is discussed.

Spondylocarpotarsal synostosis syndrome (with a posterior midline unsegmented bar).

Spondylocarpotarsal synostosis syndrome (SSS) is characterised by malsegmentation of the thoracic spine and carpal/tarsal fusions. A unilateral or bilateral unsegmented bar may be present in the thoracic spine. Presenting clinical signs are congenital scoliosis early in life, and shortening of the trunk with scoliosis and/or lordosis in older children. We report a 13-year-old girl with SSS and a midline unsegmented bar running along the spinal processes of T3 to L2 and extending into the posterior vertebral elements.

Distinctive new form of spondyloepimetaphyseal dysplasia with severe metaphyseal changes similar to Jansen metaphyseal chondrodysplasia.

We report a boy with a unique, "new" form of spondyloepimetaphyseal dysplasia. The conspicuous features of the spinal changes were the delay in ossification of the cervical spine and posterior elements of the thoraco-lumbar spine. The vertebral bodies were of abnormal shape but of normal size and well ossified. The hallmark of epiphyseal changes was markedly delayed ossification (bone age). The severely disturbed metaphyseal ossification was similar to Jansen metaphyseal dysplasia. This pattern of changes has not yet been described in spondyloepimetaphyseal dysplasia.

Electron microscopic studies of the interaction between ovine alveolar macrophages and Mycoplasma ovipneumoniae in vitro.

The interaction between Mycoplasma ovipneumoniae and ovine alveolar macrophages with and without the addition of antibody was observed by both scanning and transmission electron microscopy. Mycoplasma ovipneumoniae organisms had the ability to attach to the plasma membrane of macrophages without inducing phagocytosis although they stimulated mitotic division in early cultured cells. The addition of specific antibody to mycoplasma--macrophage cultures stimulated phagocytosis of the organisms. Macrophages stimulated by antibody showed rapid and extensive spreading on the coverslip and their plasma membrane exhibited prominent ruffling. Many openings and fine cytoplasmic pits were also evident. With transmission electron microscopy numerous micro-organisms were seen within phagocytic vacuoles two hours after the addition of antibody.