The evidence that periodontitis-associated bacteria contain potent PBA factors is very strong. Clearly, antibodies directed against non-oral antigens are produced in the inflamed periodontal lesion, and PBA appears to contribute to that production. It is also clear that B cells and plasma cells are the major cell types in the periodontal lesion. Furthermore, alterations in the regulation of B-cell responses to PBA factors are associated with severe periodontal disease. However, evidence demonstrating that activated B cells and plasma cells are directly involved in the pathogenic mechanisms leading to destruction of the periodontal support is still circumstantial. Polyclonal B-cell activation and potential pathways by which PBA-stimulated cells could be involved in periodontal destruction remain largely hypothetical. It appears that IL-1 is an important osteoclast-activating agent, and that LPS, which is a potent PBA factor in many systems, can elicit IL-1 production by B cells as well as by the monocyte/macrophage lineage. Recent data indicating that IL-1 is produced by numerous malignant B-cell lines lend support for the idea that B-cell IL-1 could be important in bone resorption. It is also likely that polyclonal activation may lead to production of autoantibody such as anti-type I and anti-type III collagens, and the destruction of self tissues through ADCC reactions, immune complex formation, and complement activation. Further research is needed to determine how the B cell/plasma cell may participate in tissue injury in periodontitis, and how the B-cell response to PBA factors is regulated.

Animals↗

PubMed1978

The effect of acrylamide on human polymorphonuclear neutrophils in vitro.

Acrylamide (CH2CHCONH2), the vinyl monomer of the industrially useful polymer polyacrylamide, is a recognised neurotoxin. Investigation in our laboratory indicated that, in addition to its neurotoxic effect, acrylamide depressed human polymorphonuclear leucocyte (PMN) chemotaxis in vitro. As genetic or chemical inhibition of PMN phagocytic function frequently pre-disposes patients to repeated bacterila infections, the in vitro effects of acrylamide on several other human PMN functions were studied. Acrylamide in concentrations up to 37.5 mg/ml had no effect on trypan blue uptake. However, bacterial ingestion, killing, and induced chemiluminescence were depressed by pre-treatment with acrylamide (10 mg/ml). It seems unlikely that acrylamide exposure alters host resistance to bacterial infections, because (a) large doses of acrylamide are necessary to interfere with phagocytic functions, (b) acrylamide reacts readily with proteins on many tissue cells and may be made inaccessible or non-toxic to PMN'S and (C) PMNs have a rapid turnover rate in the body and non-functional cells would be rapidly replaced by functional cells.

Acrylamides↗

PubMedDate not supplied

Metallurgical, manufacturing and surface finish requirements for high purity stainless steel system components.

The stainless steel piping systems that distribute water for injection (WFI) and other critical fluids in pharmaceutical and biotechnology plants will be the subject of this paper. We will confine our focus to the two major components of such systems--tubing and fittings. It should be noted that the discussions here can certainly be applied in the selection of other components such as valves, filter housings, pumps, and tanks used in these industries. The purpose of this paper will be to guide user choices with regard to raw material selection, surface preparation, and surface analysis within the context of system requirements. A suggested material specification for stainless steel tubing and fittings will also be presented.

Drug Industry↗