Evaluation of morphological criteria in the cytological diagnosis of thyroid cold nodules. A preliminary study

Although cytological diagnosis plays a significant role in the management of thyroid cold nodules, the rather high rates of false negative cases diminishes its usefulness. The purpose of this preliminary study is to evaluate the utility of numerous morphological criteria used by the cytologist to exclude benign tumours. Thirty-one cytological criteria were routinely scored as binary (yes/no) or as categories: 6 referred to the general arrangement and frequency of thyroid cells, 9 to the associated cellular and cell product elements, and 16 to the morphological features of the cells. We examined the manner in which these criteria, alone or combined, contributed to the diagnosis. The data base consisted of 171 intraoperative imprint cytological samples (143 histologically benign, 1 atypical adenoma and 27 cancers), as well as 257 thyroid cold nodule aspirates from another set of patients (198 histologically benign, 7 atypical adenomas and 52 cancers). For the imprint cytology, the diagnostic power of each criterion was individually assessed by the likelihood ratio (LR) which eliminated 11 as being undiscriminatory. The remaining independent criteria were subjected to logistic regression analysis to determine the most discriminant. Three were selected: Cellular clustering organisation, nuclear hypertrophy and colloid quantity with the latter being somewhat less powerful. Furthermore, it appears that the diagnostic power of the criteria was significantly lower when there was at least one nucleolus (number of nucleoli greater than 0). The smears gave essentially the same results as the imprints.(ABSTRACT TRUNCATED AT 250 WORDS)     

Improvement of parathyroid Tl-Tc scintigraphy by using a new image subtraction method

Forty five thallium-technetium parathyroid scans were performed preoperatively in patients with a high suspicion of parathyroid adenoma or hyperplasia. The patients were imaged after sequential IV injection of 201Tl-thallous chloride (74 MBq) and 99mTc-pertechnetate (222 MBq) using a gamma camera with a pinhole collimator. According to surgical findings, the prevalence of parathyroid abnormalities was 42/45: single (34 patients) and double (1 patient) adenomas, hyperplasia (7 patients, 16 hyperplastic glands). Three methods of analysis of scintigraphic images were compared. Method one was the visual comparison of the thallium and the technetium images. Method two used the subtraction image obtained after normalisation. Method three used a new image comparison method which performs the geometric and gray level registrations of the two images and generates the image of the significant differences. Three observers were involved in the evaluation procedures. Surgery and histological examinations were taken as the gold standard. Results show that the sensitivity is increased by applying method three. The interobserver reproducibility of the results is also higher for method three. We conclude that an adequate image subtraction technique significantly increases the diagnostic value of parathyroid scintigraphy.     

3-wheeled and 4-wheeled all-terrain vehicles: unstable and dangerous vehicles

We present the results of a questionnaire completed by 526 victims of accidents involving three- and four-wheeled all-terrain vehicles. All victims were treated at the emergency departments of 10 regional hospitals in Quebec. In 70% of cases, the vehicles overturned. Two thirds of victims were injured in accidents without collision, typically involving overturns on level ground or hills. We suggest accident reconstruction research as a means of identifying engineering solutions as one element in an injury control approach.     

Morphological analyses of paraspinal muscles: Comparison of progressive lumbar kyphosis (camptocormia) and narrowing of lumbar canal by disc protrusions

Progressive lumbar kyphosis (camptocormia), a rare, usually familial disease in elderly patients, is characterized by inability to immobilize the lumbar spine in relation to the pelvis. CT scan reveals selective involvement of the spinal muscles with a heterogeneous appearance and is in favour of a primary disorder of these muscles. Our aim was to define the muscular lesions and clarify their nature in this particular disorder. Biopsies of the paravertebral muscles of 14 patients with lumbar kyphosis and of 20 operated on for disc herniation or narrowed lumbar canal, were studied by light microscopy, histochemistry and electron microscopy. In both groups, type 1 fibre predominance and atrophy of type 2 fibres were observed. Ragged-red fibres with abnormal mitochondria also occurred. The differential feature was increased frequency of extensive diffuse or lobulated fibrosis in camptocormia. Other features related to pathogenesis could not be determined.     

Imaging of the aging brain. Part II. Pathologic conditions

The most common pathologic disorders in the elderly result in dementia, movement disorders, and/or focal neurologic deficit. Neuroimaging, particularly magnetic resonance (MR), provides a unique window into the diagnosis and understanding of such diseases. The most common cause of dementing illness is Alzheimer disease (enlarged cerebrospinal fluid spaces, focal medial temporal lobe abnormal signal intensity, cortical iron). Since the initiation of MR imaging, important questions are being asked about the role of white matter disease (signal hyperintensities) in primary degenerative dementia and the nosology of vascular dementia. Parkinsonian disorders are characterized by generalized brain atrophy and dopaminergic site (e.g., putamen, pars compacta of the substantia nigra) iron or pigmentary accumulation best visualized in disease that responds poorly to dopamine replacement therapy. A key role of imaging in the elderly is the noninvasive exclusion of mass lesion (e.g., hematoma, neoplasm). MR imaging is exquisitely sensitive for the detection of the two common abnormalities that cause focal neurologic deficit in the elderly--infarction and intracerebral hematoma.     

Human β-mannosidase deficiency associated with peripheral neuropathy

Human β-mannosidosis is an inherited lysosomal storage disorder described in only seven families. We present a further case in a black African 14-year-old boy with severely deficient β-mannosidase activity, bilateral thenar and hypothenar amyotrophy, electrophysiologically demonstrable demyelinating peripheral neuropathy, and cytoplasmic vacuolation of skin fibroblasts and lymphoid cells. The clinical and biochemical features of our patient are compared to those of previously reported patients.