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Biomedical subjects

A Pitts

Publications and source records attributed to A Pitts.

14 recordsLinked to original sources
PubMed1999

Characterization of Lhx9, a novel LIM/homeobox gene expressed by the pioneer neurons in the mouse cerebral cortex.

In order to explain the phenotype observed in Lhx2 mutant embryos, we previously proposed that an Lhx2 related gene might exist. We now have cloned a new LIM/homeobox gene called Lhx9. Lhx9 is closely related to Lhx2 and is expressed in the developing central nervous system (CNS). Lhx9 and Lhx2 have expression patterns that overlap in some areas but are distinct in others. Thus, in some developmental domains these two highly related proteins may be functionally redundant. Lhx9 is expressed in the pioneer neurons of the cerebral cortex, while Lhx2 is expressed throughout the cortical layers. Postnatally, Lhx9 is expressed in the inner nuclei of the cerebellum, while Lhx2 is in the granular layer. In the developing limbs, both genes are highly expressed in a similar pattern. Based on the expression pattern and the developmental regulation of Lhx9, we propose that Lhx9 may be involved in the specification or function of the pioneer neurons of the cerebral cortex. We show that both Lhx9 and Lhx2 bind the LIM domain binding protein Ldb1/Nli1/Clim2.

Age Factors↗
PubMed1996

Immunoglobulin-containing plasma cells recruited to cervical neoplasia.

OBJECTIVE: To determine the number and isotype of immunoglobulin (Ig)-containing cells that infiltrate various stages of cervical neoplasia from no lesion to invasive cancer. METHODS: By three-color immunofluorescent microscopy, the number and isotype of stromal plasma cells were determined for 91 specimens representing a spectrum of cervical epithelial neoplasia as follows: no lesion (n = 12), koilocytic atypia (n = 13), mild dysplasia (n = 21), high-grade squamous intraepithelial lesions (SIL; n = 22), and invasive carcinoma (n = 23). RESULTS: The Ig-positive cell counts were markedly increased under the low-grade SIL. Specifically, the mean number of IgG-positive plasma cells was significantly increased (P < .003) under the subepithelial stroma of mild dysplasia as compared with no SIL, high-grade SIL, or invasive carcinoma. These immunocyte infiltrates were clustered in the stroma beneath koilocytes, which also demonstrated IgG-positive intracellular staining. CONCLUSION: Low-grade cervical lesions are infiltrated by IgG plasma cells to a greater extent than high-grade or invasive cervical lesions, suggesting that antibody responses are preferentially recruited in early cervical neoplasia, giving credence to the concept that low-grade lesions represent a human papillomavirus infection of the cervix rather than a neoplastic condition.

Female↗
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↗
PubMed1982

Gastroplasty in patients with symptoms of reflux esophagitis.

Forty-one patients underwent gastroplasty by the technique of Gomez and has at least one year of follow-up study. Fifteen patients had symptoms of reflux esophagitis preoperatively. At present, only two have symptoms of reflux esophagitis and both were free of symptoms until reversal of the gastroplasty. pH studies of the proximal pouch were performed preoperatively and postoperatively in 14 patients. There was a significant increase in proximal pouch pH after gastroplasty. Following gastroplasty, there is an immediate decrease in acid reflux and symptom reduction is observed to last at least one year. Patients with reflux esophagitis should not necessarily be excluded from consideration for gastroplasty.

Adult↗
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↗