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OBJECTIVE:To investigate changes in bone metabolism by positron emission tomography (PET), as well as spatial relationships between bone metabolism and magnetic resonance imaging (MRI) quantitative markers of early cartilage degradation, in anterior cruciate ligament (ACL)-reconstructed knees. DESIGN:Both knees of 15 participants with unilateral reconstructed ACL tears and unaffected contralateral knees were scanned using a simultaneous 3.0T PET-MRI system following injection of 18F-sodium fluoride (18F-NaF). The maximum pixel standardized uptake value (SUVmax) in the subchondral bone and the average T2 relaxation time in cartilage were measured in each knee in eight knee compartments. We tested differences in SUVmax and cartilage T2 relaxation times between the ACL-injured knee and the contralateral control knee as well as spatial relationships between these bone and cartilage changes. RESULTS:Significantly increased subchondral bone 18F-NaF SUVmax and cartilage T2 times were observed in the ACL-reconstructed knees (median [inter-quartile-range (IQR)]: 5.0 [5.8], 36.8 [3.6] ms) compared to the contralateral knees (median [IQR]: 1.9 [1.4], 34.4 [3.8] ms). A spatial relationship between the two markers was also seen. Using the contralateral knee as a control, we observed a significant correlation of r = 0.59 between the difference in subchondral bone SUVmax (between injured and contralateral knees) and the adjacent cartilage T2 (between the two knees) [P < 0.001], with a slope of 0.49 ms/a.u. This correlation and slope were higher in deep layers (r = 0.73, slope = 0.60 ms/a.u.) of cartilage compared to superficial layers (r = 0.40, slope = 0.43 ms/a.u.). CONCLUSIONS:18F-NaF PET-MR imaging enables detection of increased subchondral bone metabolism in ACL-reconstructed knees and may serve as an important marker of early osteoarthritis (OA) progression. Spatial relationships observed between e

The short-fibered chrysotile-asbestos of serpentine and the serpentine show a fibrogenic action on the lung tissue, however, it is more pronounced in the asbestos. The opinion of some authors on the biological inertness of the serpentine and the short fibers of asbestos was not verified. Data indicate that the formation of fibrosis was connected not with the solution of silicic acid nor with the fibroacerous shape of the asbestos particles. The authors hypothesize that asbestos and serpentine, despite the significant morphological differences between them, are capable of causing fibrosis since the asbestos, which possesses a tubular structure, also has a large specific surface. The probability of the formation of active chemosorptive centers in it are higher than in the serpentine. In conclusion, it is possible to show that in the fibrogenic action of asbestos; the decisive properties are the physical-chemical and colloidal properties of its surface., Edited trans. of Gigiena i Sanitariya (USSR) n11 p10-14 Nov 66, by Catherine M. Barber.

Anaphylaxis with desensitization demonstrated that in animals with experimental asbestosis and silicosis there takes place an antigenic reconstruction of the pulmonary tissue in which antigenic complexes inherent in a normal pulmonary tissue continue to be present, but, at the same time, antigens most characteristic of a 'pneumoconiotic' lung make the appearance. There are reasons to believe that during development of an 'asbestous' and 'silicotic' pneumoconioses there also emerge antigens which are common to but one of these conditions., Edited trans. of Gigiena Truda i Professionalnye Zabolevaniya (USSR) n5 p19-21 May 73, by Victor Mesenzeff.

A general outline is given of the carcinogenic behavior of asbestos, and the effect of it and other mineral powders in inducing fibrosis and asbestosis., Edited machine trans. of Patogenez Pnevmokoniozov, Trudy Vsesoyuznogo Simpozyuma, n.p., 18-20 Nov 1968. Sverdlovsk, 1970 p16-34, by R. Wallace.