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Biomedical subjects

A Pitts

Publications and source records attributed to A Pitts.

9 recordsLinked to original sources
PubMed1991

Immunoglobulin isotype distribution of locally produced autoantibodies to collagen type I in adult periodontitis. Relationship to periodontal treatment.

Production of antibodies to collagen type I was analyzed by means of an enzyme-linked immunospot (ELISPOT) assay in patients with chronic adult periodontitis (AP) before and after periodontal hygiene treatment. Anti-collagen type I antibody-secreting cells were found among mononuclear cells enzymatically eluted from inflamed gingiva in 9 of 15 patients with untreated AP and in 4 of 14 hygiene-treated patients with a varied isotype distribution. A notably high prevalence of IgG and IgM isotypes was observed for the anti-collagen antibodies in untreated patients. With wide variation, chronic AP was characterized by a high frequency of spontaneous IgG and low numbers of IgA and IgM-producing cells. Periodontal hygiene treatment significantly reduced the number of IgA and IgM-secreting cells. Although AP is not an autoimmune disease in the accepted sense, our results indicate that local autoimmune reactions to collagen type I are common in untreated AP, implying an interplay between periodontal infection and autoimmunity.

Autoantibodies↗
PubMed1991

Local IgA and IgM rheumatoid factor production in autoimmune MRL/lpr mice.

Spontaneous local immunoglobulin (IgA, IgG, IgM) as well as IgA and IgM rheumatoid factor (RF) production in salivary glands, lymph nodes, and spleen was analyzed at various ages in autoimmune MRL/Mp-lpr/lpr (MRL/lpr) mice by using an ELISPOT assay. The longitudinal design of the study permitted correlations with severity of disease in salivary glands (sialadenitis). Local production of immunoglobulins in salivary glands and lymph nodes occurred with a pattern of IgG much greater than IgM greater than IgA. This isotype pattern differed from that simultaneously observed in spleen where IgG did not predominate to the same extent. Moreover, the spleen was the major site of IgM production. Rheumatoid factors constituted a significant fraction of local IgA and IgM in involved salivary glands. The pattern of IgA RF isotype expression in salivary glands contrasted with that observed in spleen. While the number of IgA and IgG secreting cells increase at an early age, the peak of RF production in salivary glands occurs in older mice. Furthermore, the level of immunoglobulin secretion was positively correlated with disease severity in salivary glands. The results suggest that local RF production is a secondary event in salivary gland inflammation in MRL/1pr mice rather than an initiating factor in this process.

Animals↗
PubMed1978

Subpopulation of human tonsillar lymphocytes with mitochondria visible by light microscopy.

We observed a subpopulation of human tonsillar lymphocytes with cytoplasmic inclusions that stained orthochromatically blue with Wright stain. These lymphocytes represented fewer than 2% of cells in suspensions of cells from most tonsils; however, suspensions of tonsillar cells from 4 to 18 studied patients contained more than 2% (2.8%--6.4%) lymphocytes with cytoplasmic inclusions. These cells sedimented less rapidly than the modal population of lymphocytes in a previously described isokinetic gradient. Histochemical and ultrastructural studies suggested that the stained inclusions were prominent mitochondria stained by the Wright stain.

Cell Separation↗
PubMed1975

A method for the separation of lymphocytes and plasma cells from the human palatine tonsil using sedimentation in an isokinetic gradient of Ficoll in tissue culture medium.

Several methods for the dissociation of human tonsils into cell suspensions were compared. Dissociation of tonsils using 0-25 per cent trypsin gave both the largest number of total cells and the largest number of plasma cells per gram of tonsil. Lymphocytes and plasma cells were separated in a previously described isokinetic gradient of Ficoll in tissue culture medium. In the purest gradient fractions, lymphocytes were 97-2 plus or minus 1-9 per cent of nucleated cells. The purest gradient fractions contained 43-1 plus or minus 5-9 per cent plasma cells. More than 95 per cent of purified lymphocytes and plasma cells excluded Trypan Blue.

Cell Separation↗
PubMed1973

Separation of lipase-positive cells from suspensions of pancreas cells in an isokinetic gradient of Ficoll in tissue culture medium.

Lipase-positive cells were separated from suspensions of pancreas cells both by velocity sedimentation and by isopycnic sedimentation. Lipase-positive cells were 51.0 +/- 9.6% of the disaggregated pancreas cells in the starting sample suspension. The purest gradient fractions from experiments using velocity sedimentation for cell separation contained a mean of 98.8 +/- 0.6% lipase-positive cells. Cell separation using isopycnic centrifugation was less effective than cell separation using velocity sedimentation and resulted in a mean purity of only 89.8 +/- 6.8% lipase-positive cells. Lipase positivity was assessed using the Gomori technic with the conditions for fixation slightly modified to be suitable for disaggregated cells.

Animals↗