Barnet M. Levy

Humoral studies of periodontal disease: I. Characterization of immunoglobulins quantitated from cultures of gingival tissue☆

Abstract Inflamed gingiva from patients with various clinical stages of chronic destructive periodontal disease (CDPD) were placed in organ culture. Quantitation of organ culture supernatant immunoglobulins demonstrated that IgG predominated in all three clinical disease stages: gingivitis, severe gingivitis, and periodontitis. Previous immunopathological studies suggested a predominance of IgG surface and cytoplasmic staining lymphocytes in the destructive lessions of periodontitis. In the present study there was a preponderance of IgG in gingival organ culture supernatants from patients with severe periodontitis. The levels of IgG in periodontitis were 7 times greater than IgA and 12 times greater than IgM. A restrictive IgG subclass distribution was detected in the culture supernatants which differed from normal autologous plasma IgG subclasses. Direct evidence for synthesis of IgG in unstimulated gingival organ cultures was provided by the incorporation of l -[3H]glutamine and l -[3H]leucine into IgG. Addition of cyclohexamide inhibited the subsequent incorporation of label into IgG suggesting de novo synthesis. Evidence from IgG subclass quantitation and incorporation of labeled amino acids into IgG indicate that the IgG found in periodontitis tissue is a product of locally secreting plasma cells and is not serum derived. The de novo synthesis of IgG in unstimulated cultures suggested in situ sensitization to antigenic determinants.

Magnesium Deficiency I. The Femur in Acute Magnesium Deficiency

Duckworth et al. (1) demonstrated a decrease in percentage ash of the leg bones of magnesium-deficient young growing albino rats. Clark (2) and Clark and Belanger (3) on the other hand, using adult rats which had been maintained on a magnesium-deficient diet, reported no decrease in the percentage ash of the femur. Indirect evidence of the effect of magnesium on bone has been supplied by histological studies. Bernick and Hungerford (4) demonstrated an arresting of the proliferating cartilage of the epiphyseal plate, which was later confirmed by Clark and Belanger (3). By the use of tetracycline labeling on magnesium-deficient bones, Trowbridge and Jenks (5) demonstrated a reduction in appositional bone formation. This report describes the effect of magnesium deficiency on the mineral in bone. Materials and Methods. Twelve 100 g male rats of the Sprague-Dawley strain were divided into two groups. Both groups were placed on triple distilled deionized water and were fed Heggtveit low, magnesium test diets purchased from General Biochem (Cat. No. 170489). The diets of the control group were supplemented with 500 ppm Mg in the form of MgSO4 (Analytical Reagent Grade). When an experimental animal appeared to be near terminal stages of the deficiency, it and its control were anesthetized with ether and killed by cardiac puncture. The appendicular skeletons were dissected out along with the head and vertebral column. The femurs were Grenz rayed and scanned by γ-ray absorption densitometry as described by Cameron and Sorenson (6, 7). The scans were made cross-sectionally at 1 mm intervals. The femurs were then sectioned into thirds, the bone marrow was removed and the bone sections were defatted in 1:1 mixture of ether:ethanol. The bones were then weighed, ashed at 550° and reweighed.