Localized amyloid deposition in cartilage is glycosaminoglycans-associated

Localized amyloid deposition is known to occur commonly in the articular cartilage of elderly patients. Its pathogenesis is uncertain and it is not known if other cartilage-containing tissues also contain amyloid deposits. Systemic amyloid deposits are known to contain highly sulphated glycosaminoglycans, a major constituent of cartilage. As the composition of articular cartilage glycosaminoglycans is known to change with age, we sought to identify whether localized amyloid deposition in cartilage was glycosaminoglycan-related. We examined specimens of articular cartilage over a wide age range and also examined a variety of cartilaginous tumours and tumour-like lesions for the presence or absence of amyloid deposits. Using mucin histochemistry (alcian blue: MgCl₂ critical electrolyte concentration) and immunohistochemistry, we found that highly sulphated glycosaminoglycans (0.9 M and 1 M MgCl₂), in particular keratan sulphate, localized to amyloid deposits in both articular cartilage and loose bodies derived from the articular surface. Other cartilaginous lesions (including loose bodies of primary synovial chondromatosis) were negative for amyloid and did not contain highly sulphated glycosaminoglycans. These findings suggest that changes in specific highly sulphated glycosaminoglycans may play a role in localized amyloid deposition in articular cartilage.     

Identifying the denture space

In the absence of pre-extraction records, the positioning of teeth on complete dentures is a somewhat arbitrary procedure. The present study was designed to evaluate a number of different criteria for tooth placement. Miniature foil strain gauges were used to measure the forces brought to bear on complete dentures by the lingual and peri-oral musculature. Previous studies of the pattern of post-extraction resorption found that the vestige of the lingual gingival margins of the maxillary teeth could be identified on the cast and it was suggested that these biometric guides are reliable for the correct placement of the upper artificial teeth. The results reported confirmed the use of biometric guides to tooth placement as a reliable method of positioning the teeth in Class I edentulous cases.     

POSTOPERATIVE ANALGESIA FOLLOWING BRACHIAL PLEXUS BLOCK

The time from the end of surgery to the administration of thefirst post-operative analgesic has been measured in 86 patientsfollowing brachial plexus block with bupivacaine, lignocaine,mepivacaine or prilocaine. A significant increase in time occurredwith bupivacaine; the combination of regional and general anaesthesiasignificantly increased the time when compared with generalanaesthesia in the same patient. In children, the use of regionalanaesthesia almost removed the need for analgesia after surgery.