A new staining technique using heavy metals (lead-uranyl acetate) has been developed to allow visualization of bone microdamage using both light microscopy and scanning electron microscopy operated in its back-scattered mode (BSE). At the light microscopic level, the number of microcracks counted in sequential sections of human ribs is the same for both the traditional basic fuchsin method of differentially staining microcracks and the new lead-uranyl acetate procedure. With BSE study, however, the number of microcracks observed is significantly reduced in all samples, because of the reduction of projection effect error associated with surface based imaging techniques. Application of the lead-uranyl acetate staining technique to ex vivo-loaded crack propagation specimens showed an extensive ultrastructurally disrupted region associated with the crack path through bone, consistent with the damage process zone around cracks in toughened composite materials.

Adult↗

PubMedDate not supplied

Limited survival of rat small bowel transplants preserved in University of Wisconsin solution for 48 hours.

We have previously shown that rat small bowel may successfully be transplanted after preservation for 24 hours. In this study, syngeneic rat small bowel transplants were studied by light microscopy and transmission electron microscopy during and after preservation in University of Wisconsin (UW) solution for 48 hours. A total of 6 transplants were carried out using a previously described, standardized technique. In most cases, the bowel appeared histologically well preserved at the end of the 48 hr storage period (prior to implantation). Upon revascularization, however, reperfusion injury was dramatic, with loss of villi and crypts and inflammatory cells in all layers. The bowel was abnormal grossly as well as microscopically. This injury was irreversible with persistently abnormal histology for up to 1 week in all but 2 cases. We conclude that UW solution alone may allow satisfactory preservation of intestinal grafts for 48 hours only in isolated cases, and is therefore not adequate for predictable, satisfactory 48 hr preservation. Attempts to prevent reperfusion injury with oxygen-free radical scavengers are in progress.

Adenosine↗

PubMedDate not supplied

Synovial urate crystals in acute gouty arthritis. A study of their origin and significance.

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Acute Disease↗

PubMedDate not supplied

Psoriatic arthropathy and crystal-induced synovitis.

We demonstrated the simultaneous occurrence of psoriatic arthropathy and the 2 major types of crystalline arthritis--pseudogout and gout. The crystals found within aspirated synovial fluid and exudative leukocytes were unequivocally identified using the compensating polarizing microscope as calcium pyrophosphate dihydrate in one case and sodium monourate in the other. The surface topography of the intracellular sodium monourate crystals were also displayed.

Aged↗