Acid-etching of caries-like lesions of enamel: a scanning electron microscopic study.
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Biomedical subjects
Publications and source records attributed to M J Hicks.
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To resolve the controversy over the immunologic nature of nodular mixed lymphoma (NM), we examined nine cases of NM for surface antigens using both tissue section and cell suspension methods. These were contrasted with 12 cases of nodular poorly differentiated lymphocytic lymphoma. We found two major B cell types of NM, those with monoclonal immunoglobulin (SIg+)-positive nodules with an SIg+B1+B2+Ia+T- phenotype (four cases) and those with nodules devoid of immunoglobulin with an SIg-B1+B2-Ia+T- phenotype (five cases). Our SIg+ NM cases appear similar to nodular poorly differentiated lymphocytic lymphoma (SIg+B1+B2+Ia+T-), except suspension assay indicates fewer SIg+ cells in NM. In our SIg- NM cases, the neoplastic nodules consistently expressed B1 and Ia-like antigens and lacked T cells, indicating a B cell neoplasm similar to many large cell lymphomas. By demonstrating a B cell antigen in SIg- nodules, we substantially resolve the controversial NM cases previously called "null" or T cell. The two distinct immunotypes indicate the complexity of B cell antigenic expression in NM and might also explain the variable response to therapy in NM described in previous studies. Finally, we describe NM cases with the simultaneous occurrence of several stages of B cell differentiation. This suggests that some NM cases are not frozen in a single stage of B cell development but may express a range of B cell antigens. NM, then, may be a paradigm of variable, simultaneous B cell maturation.
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T-lymphocyte subpopulations were studied in 68 patients with monoclonal gammopathies and 27 age-matched healthy controls using the monoclonal antibodies (mAb) OKT-3, OKT-4 and OKT-8. 13 patients had untreated multiple myeloma (MM), 51 had MM and were receiving intermittent pulse chemotherapy or were in remission and followed up without treatment. Four patients had a monoclonal gammopathy of unknown significance (MGUS). Analysis of the data for disease activity demonstrated a significant imbalance of T-lymphocyte subpopulations in patients with stable (plateau phase) MM. In these patients the relative number of cells with suppressor phenotype (OKT-8 positive) was significantly increased (p less than 0.0001) and the relative number of cells with helper phenotype (OKT-4 positive) significantly decreased (p less than 0.0001) when compared with normal controls or patients with active MM. Patients with stable disease also had a significantly higher absolute number of OKT-8 positive cells than patients with active MM (p = 0.04). Additionally, in vitro functional studies showed significant suppression of clonal growth of the human myeloma cell line (RPMI 8226) by a soluble suppressor factor of OKT-8 positive cells from the peripheral blood of healthy donors as well as from bone marrow aspirates of patients with MM. These findings support the hypothesis that T-lymphocyte subpopulations play an important role in the control of proliferation of the myeloma cell clone in patients with low cell mass (stable phase) multiple myeloma.
This study examines the relationship between age and mitogen-induced lymphocyte blastogenesis. Lymphocytes were stimulated with PHA; Concanavalin A (Con A), and PWM in 156 normal, healthy subjects ranging in age from birth to 75 years. The findings indicate a gradual but significant decrease in PHA- and Con A-induced blastogenesis with increasing age. The decrease in Con A and PHA induced in vitro lymphocyte function begins in early childhood and young adulthood, respectively, and continues throughout the age range studied. In addition, there appears to be a decreased range of lymphocyte functional capacity among the 50-75-year-old subjects. The clinical and laboratory implications of these observations are discussed.
The effect of acid-etching on SnF2-treated caries-like lesions was investigated. The results suggested that remineralization occurred, limited to the superficial portions of the lesions. In addition, we observed etching patterns which are comparable to those described for etched sound enamel.
Quantitation of T and B lymphocytes in infants and children is an important test in the diagnosis of a suspected immuno-deficiency. Previous studies indicated that the absolute and relative numbers of lymphocyte subpopulations vary with age, but these data in the pediatric age group are incomplete and often contradictory. We reviewed the literature and investigated the relationship between age and lymphocyte subpopulations in healthy infants and children using common methods and recent methodologic improvements. We found that absolute numbers of T and B cells followed the same trend as the total lymphocyte count, which was elevated at birth, increased in the first six months, and then gradually decreased to adult levels at approximately 13 years of age. Compared with adult values, the percentage of B cells also was higher at birth and continued to increase for six months, followed by a gradual decrease to adult levels by late childhood or early adolescence. The percentage of T cells gradually increased to adult levels by the same age range.
The purpose of this study was to evaluate, prospectively, the clinical usefulness of the rate nephelometric method for determining rheumatoid factor (RF) activity, measured in International Units (IU), in patients with rheumatoid arthritis. These results were compared with those of standard latex agglutination titration. The overall correlation between clinical activity and RF activity measured by rate nephelometry and serologic titration are similar, i.e., r = 0.47 (P less than 0.001) and r = 0.43 (p less than 0.001), respectively. However, on an individual patient basis, the nephelometric determination appears to correlate better with disease activity and response to therapy than do titers. The RF activity measured in IU would give the clinician a more sensitive and precise tool with which to follow RF activity in individual patients with active disease.
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This study examines the relationship between percent recovery of lymphocytes and T- and B-cell typing results. Lymphocytes were recovered from heparinized whole blood by density gradient centrifugation. T- and B-cells were enumerated by spontaneous sheep rosetting and direct fluorescent antibody staining for surface immunoglobulin, respectively. The findings indicate that at low recovery levels ( less than 80%) there is a significant increase in variability of lymphocyte typing results and a significant increase in IgG-bearing B-lymphocytes. Possible explanations for these findings are discussed. These results suggest that lymphocyte typing results should be interpreted in relation to recovery level and that recovery levels of greater than or equal to 80% are desirable.
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Mammography and physical examination of the breast are evaluated as screening instruments for detecting breast cancer based on local biopsy data obtained from women enrolled in a national breast cancer screening program. One hundren thirteen cancers (15.5%) of women who underwent biopsy) were detected. The individual sensitivities of mammography and physical examination for detecting breast cancer are 62% and 24%, respectively. The sensitivity of the two methods combined is 75% (85 of 113). Thirty-seven cancers were in situ or minimally invasive (less than or equal to 1 cm in greatest dimension). Eighty-one percent (30 of 37) of these small cancers were detected by screening, and they comprised 35% (30 of 85) of all cancers detected by mammography, physical examination, or both. Improved survival is anticipated due to this high rate of discovery of small cancers.
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We describe the measurement of rheumatoid factor in human sera with a rate nephelometer. The National Reference Preparation for Rheumatoid Factors is used to calibrate the assay in International Units. We used Hyland Positive Control, Level I, as a secondary standard. The standard curve is exponential, but is linear when plotted on log-log graph paper. Aggregated immune globulin (IgG) is the antigen used to detect rheumatoid factor (IgM-class antibody to IgG). The rate reaction measures the rate of increase in light-scatter by the antigen-antibody complexes; the reaction takes place in 17 to 20 s. Precision, linearity, and accuracy are excellent. Results agree well with those for a commonly used latex precipitation test. The advantages of speed, quantification in International Units, and superior discrimination of concentration as compared to serological titration provide a more reliable test for use in the diagnosis and treatment of rheumatoid arthritis.
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