Chrysotile asbestos exposure in the manufacturing of thermal insulating boards.

Exposure to asbestos fibers has been extensively studied in milling, mining of asbestos fibers, and in industries manufacturing asbestos-cement sheets, pipes, etc. However, very few studies have been reported in asbestos textiles, brake lining workers, and insulation products. In the present investigation, chrysotile exposure monitoring was carried out in a small thermal insulating boards manufacturing facility. Twenty-eight samples were analyzed from various locations like feeding of raw materials, weighing, pressing, machine grinding, and hand finishing of final products. Twenty-five percent of the samples were found to be above ACGIH TLV of 0.1 fibers per milliliter. However, mean fiber concentrations were found to be lower than 0.1 fibers per milliliter, except for the process of feeding of raw materials where the mean fiber concentration was 0.1087+/-0.0631 fibers per milliliter.

Scleredema diabeticorum--a case report.

A 41 year male, diabetic on treatment presented with persistent erythema and. "taut" skin over neck and back since 1 year. The lesions showed symmetric and gradual progression. There was no history of prior sore throat. On examination effected skin was erythematous, woody hard and unpinchable. Scleredema diabeticorum (diutinum), although sharing clinical and historical features with Scleredema adultorum has no prodromal infection, is more extensive and affected individuals are characteristically obese, middle aged diabetics who often have accompanying microangiopathies and macroangiopathies. Recognition of scleredema by the physician has prognostic and therapeutic implications in the management of the coexisting diabetes.

Spinal osteoblastoma: CT and MR imaging with pathological correlation.

OBJECTIVES: To illustrate the CT and MRI features of spinal osteoblastomas and correlate the imaging with histological findings. DESIGN: In a retrospective review the CT and MRI features of spinal osteoblastomas with respect to mineralisation, signal intensity (SI), adjacent reactive changes, enhancement following gadolinium-DTPA (5 cases) and adjacent soft tissue masses were compared and correlated with the histological findings including the degree of osteoid formation and matrix mineralisation, vascularity and surrounding reactive changes in bone and soft tissue. PATIENTS: Eleven patients (7 males and 4 females; age range 8-43 years, mean age 19.5 years) with 12 osteoblastomas (1 patient suffered a recurrence) were studied. RESULTS: All lesions showed classical features on CT with varying degrees of matrix mineralisation, whereas MRI identified mineralisation in only eight of 12 cases. MRI showed low signal intensity of the lesion on both T1- and T2-weighted sequences in several cases in the absence of heavy mineralisation. In these cases, histological examination revealed diffuse osteoid production by the tumour. All patients given gadolinium showed enhancement within the tumour on MRI. Reactive bone marrow changes were identified on MRI in 10 cases, and in five of these the changes were at multiple levels. An adjacent soft tissue mass was demonstrated in five cases, but extraosseous tumour was present histologically in only two of these. CONCLUSIONS: The MRI appearances of spinal osteoblastomas are varied and show no characteristic features. MRI may also overestimate the extent of the lesion due to extensive reactive changes and adjacent soft tissue masses. CT should continue to be the investigation of choice for the characterisation and local staging of suspected spinal osteoblastomas.

Radiology of skeletal tuberculosis.

In recent years, the incidence of tuberculosis (TB) has increased, primarily in developing countries, but also in Europe and North America. The association between TB and human immunodeficiency virus infection is well-documented. In these cases, TB is more likely to be extrapulmonary. The spine is the most common site for skeletal TB. Atypical appearances may be present in immigrants. Plain radiography remains the cornerstone for imaging, but newer cross-sectional modalities such as computed tomography, ultrasonography, and magnetic resonance imaging are becoming increasingly valuable in early and accurate diagnosis. This article reviews the features of musculoskeletal TB and the role that imaging plays in diagnosis and management.

Osteoid osteoma and osteoblastoma of the spine. Factors associated with the presence of scoliosis.

STUDY DESIGN: A retrospective study of 44 museum cases of spinal osteoid osteoma or osteoblastoma and a meta-analysis using 421 additional cases from a review of the literature. OBJECTIVES: To identify the factors that are associated with the development of scoliosis in these patients. SUMMARY OF BACKGROUND DATA: Painful scoliosis is a well recognized presentation of spinal osteoid osteoma and osteoblastoma and is considered to be secondary to pain-provoked muscle spasm on the side of the lesion. Previous studies have been based on small numbers of patients that did not permit statistical validation of the reported observations. METHODS: Eight factors were assessed including: age, gender, duration of symptoms, site of lesion in the spine, vertebral level of lesion, site of lesion in the individual vertebra, type of lesion, and Cobb angle at presentation. Reports were reviewed only if the presence or absence of scoliosis could be determined. Statistical analyses initially were performed on the museum cases and then on a combination of museum cases and cases from the literature. RESULTS: Overall, 63% of subjects had scoliosis. The lesions were typically present on the concave aspect of the curve. Three cases of scoliosis from the literature involved lesions that were reported to be on the convexity. Scoliosis is significantly more common in cases of osteoid osteoma than in cases of osteoblastoma (P < 0.0001); lesions are more common in the thoracic and lumbar regions than in the cervical region (P < 0.0001), in lower cervical region than in the upper cervical region (P value = 0.0027), and they are more commonly located to one side of the midline (P < 0.0001). Age, gender, and duration of symptoms were of no significance. CONCLUSIONS: The findings support the concept that scoliosis is secondary to asymmetric muscle spasm in patients with spinal osteoid osteoma or osteoblastoma.

Unusual imaging findings in association with spinal osteoblastoma.

This paper describes four patients with spinal osteoblastoma that had unusual imaging features. Two cases arose in the cervical spine and two in the thoracic spine. Three tumours were associated with diffuse sclerosis of the vertebral body (an 'ivory vertebra'). All of these lesions either arose in the vertebral body or extended into the body from the adjacent pedicle. Reactive sclerosis at multiple levels was seen in three cases (one involving adjacent vertebral bodies, two involving adjacent pedicles or laminae and one involving multiple ribs). Osteophyte formation was identified bridging the disc space on the concave side of a scoliosis in two cases. Another case had an unusual scintigraphic appearance with an area of linear activity adjacent to the tumour. The finding of an 'ivory vertebra' in a child or young adult should raise the possibility of osteoblastoma involving the vertebral body, especially if there is an associated scoliosis.

Spinal osteoblastoma: relationship between paravertebral muscle abnormalities and scoliosis.

OBJECTIVE: To illustrate the variety of paravertebral muscle abnormalities as seen on computed tomography (CT) or magnetic resonance imaging (MRI) in association with spinal osteoblastomas and correlate the findings with the presence of scoliosis. DESIGN: In a retrospective study the clinical notes, plain radiographic, CT and/or MRI features were reviewed for the presence of scoliosis and paravertebral muscle abnormality (either inflammation or atrophy). PATIENTS: Twelve patients (7 male, 5 female) with a mean age of 17 years were studied. Three lesions occurred in the cervical spine, five in the thoracic spine and four in the lumbar spine. RESULTS AND CONCLUSIONS: Nine patients had scoliosis. All patients with a thoracic or lumbar lesion and scoliosis (n = 8) had an associated abnormality of the paravertebral muscles (usually atrophy with fatty replacement). One patient with a lumbar lesion and no scoliosis had normal paravertebral muscles. One patient with a cervical lesion had thoracic scoliosis but no muscle abnormality in the cervical region, while two patients with cervical lesions and no scoliosis showed muscle abnormalities. The results support the clinical hypothesis that scoliosis in patients with spinal osteoblastoma is due to paravertebral muscle spasm, although this would not appear to be the case for cervical lesions.