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-A study of heavy metals in estuarine sediments and foraminifera1 tests along with foraminifera1 distributions from Southampton Water indicates that: a) heavy metals have a marked effect upon foraminiferid distribution. Some species are able to tolerate pollution and their relative abundance increases at discharge points, whereas other species develop test deformities. Investigation of cores show that no deformed specimens exist within sediments prior to the introduction of pollution. b) deformed specimens contain higher levels of elements such as Cu and Zn than non-deformed specimens. This indicates that heavy metals may be responsible for the abnormalities within foraminiferid tests. Culture experiments support this hypothesis. Specimens of Ammonia beccarii (Linnk) developed abnormal chambers over a period of 12 weeks within a culture medium containing 10-20ppb of Cu.

Previous immunohistochemical data have shown that the 44-kDal bone phosphoprotein (44K BPP, also called sialoprotein I or oestopontin) recently isolated in our laboratory was synthesized by osteoblasts and osteocytes and was expressed early during differentiation of bone-forming cells. We report here the presence of 44K BPP antigenicity at certain ectopic sites, namely, the proximal-convoluted tubule of the kidney, neurons, sensory and secretory cells in the internal ear. To insure specificity and reproducibility, different immunohistochemical methods were used and affinity-purified antibodies against two separate preparations of pure 44K BPP were tested. In the cells of the proximal-convoluted tubule, 44K BPP immunoreactivity was observed within apical endocytotic vacuoles and within lysosomes. This staining thus correlates with the degradation of the 44K BPP epitope which we previously demonstrated to occur in serum. On the other hand, in the neurons of the acoustic ganglion and the sensory cells of the macula, 44K BPP immunoreactivity was associated with the Golgi apparatus indicating synthesis and secretion by these cells. The finding that the 44K BPP (or a structurally related molecule) is synthesized by neurons and neuroepithelial cells deserves further investigation with respect to a possible embryologic relationship between neuroectodermal cells and the precursors of some bone forming-cells of the skull.

The contributions of microwave methods and digital imaging techniques, when taken together, can reduce routine specimen processing and evaluation for diagnostic electron microscopy to a time frame never thought possible. Significant improvements in both technologies over the last 5 years led the authors to evaluate their combined attributes as the most likely candidate to provide a realistic solution in the reduction of turnaround times for diagnostic electron microscopy. For diagnostic electron microscopy to compete favorably with immunohistochemistry and other ancillary diagnostic techniques, it must improve its turnaround time. To evaluate this hypothesis the microwave-assisted processing results of over 2,000 diagnostic cases were evaluated as was a digital image administration system used for the acquisition and dissemination of diagnostic results. The incorporation of both technologies resulted in turnaround times being reduced to 4 h or less.

Bone gamma-carboxyglutamic acid (Gla)-containing protein (BGP or osteocalcin) and 44 kDa bone phosphoprotein (44K BPP, also called Sialoprotein I or osteopontin) have been localized at the ultrastructural level in osteoblasts from woven bones of newborn rats. Frozen, undecalcified sections of periodate-lysine-paraformaldehyde fixed specimens were incubated with affinity purified, monospecific antibodies against BGP or 44K BPP. The sites of the antigen-antibody reaction were demonstrated by the avidin-biotin-peroxidase complex method using the Hanker-Yates reagent as a peroxidase substrate. In some cases immunostaining could only be achieved after detergent treatment. The immunostained sections were then flat-embedded in Epon 812 and processed for electron microscopy. Strong specific intracellular labeling was obtained with both antibodies, but the patterns of staining differed significantly: BGP antigenicity was mainly located in the endoplasmic reticulum (ER), whereas 44K BPP behaved as a Golgi-specific antigen. In both cases, however, we found no evidence for immunostained secretory vesicles. There was no correlation between the expression of BGP by osteoblasts and the morphological aspect of these cells, their apparent degree of polarization with respect to the bone matrix, or their relation with the mineralized phase.