No abstract

Cytological analysis of material aspirated from the effusion which occasionally develops around a polyglycolic acid (PGA) osteosynthesis implant showed a predominance of inflammatory monocytes and in particular lymphocytes. In order to discover whether PGA implants are immunologically inert, density gradient-isolated peripheral blood mononuclear cells were cultured in 0.2 ml of 10% delta FCS-RPMI 1640 culture medium supplemented with 10 mg PGA. Phytohaemagglutinin (PHA) lectin, a purified protein derivate of tuberculin (PPD) antigen and culture medium alone were used as positive and negative controls. We studied lymphocyte activation kinetics on days 0, 1, 3 and 5. Major histocompatibility complex locus II antigen (MHC locus II antigen) and interleukin-2 receptor (IL-2R) expression were analysed using the avidin-biotin-peroxidase complex (ABC) method and lymphocyte DNA synthesis by using 3H-thymidine incorporation and beta-scintillation counting. Especially on culture days 0 and 1, lymphocytes and monocytes were seen by light microscopy to be attached to PGA particles. However, our results show no PGA-induced lymphocyte DNA synthesis, but PGA-induced MHC locus II antigen and IL-2R activation marker expression was seen, greater than in negative controls, but less than that seen in PPD antigen driven lymphocyte response. This suggests that PGA is an immunologically inert implant material, but it does seem to induce inflammatory mononuclear cell migration and adhesion, leading to a slight non-specific lymphocyte activation. This activation is lower than that seen in mitogen and antigen-driven lymphocyte responses.

Objective. The presence and spatial distribution of peptide-containing nerves in labial salivary glands from 10 Sjogren's syndrome patients were compared with those in salivary glands from 7 healthy controls.Methods. Results. Acini, intralobular ducts, small arteries, and postcapillary veins were richly innervated by VIP-IR fibers, whereas CPON-, CGRP-, and substance P-IR fibers were restricted to blood vessels. Peptide-containing nerves were found surrounding, but not in the middle of, the highly inflamed mononuclear cell areas.Conclusion. This topologic distribution suggests involvement of VIP-IR fibers in vascular, motor, and secretory components of the reflex salivary secretion, whereas the distribution and the vasoactive actions of CPON, CGRP, and substance P suggest a role in the regulation of the salivary gland circulation, and thus of transcapillary flow. Excessive release may contribute to a neurogenic inflammation. Local depletion and absence of trophic neuropeptide stimuli may contribute to acinar atrophy.Aside from Sjogren's syndrome, an autoimmune disease of unknown etiology characterized by keratoconjunctivitis sicca, xerostomia, and focal adenitis, psychogenic and iatrogenic factors are also common causes of "dry mouth." These factors relate, respectively, to inhibitory influences of higher central nervous system control on salivary nuclei and to peripheral anticholinergic effects, and thus illustrate the role of the autonomic nervous system in the control of reflex salivary flow. The sialopenia of Sjogren's syndrome, however, has been generally attributed to autoimmune destruction of the glandular parenchyma, the flow of saliva being roughly proportional to the mass of the secretory end-piece elements. More recently, it has become evident that in addition to the integrated vascular, motor, and secretory control of reflex salivary flow, the autonomic nervous system delivers trophic stimuli to parenchymal tissue ( 1 4 ) .