Ira B. Lamster

Evaluation and modification of spectrophotometric procedures for analysis of lactate dehydrogenase, beta-glucuronidase and arylsulphatase in human gingival crevicular fluid collected with filter-paper strips

Filter-paper strips were used to collect GCF, and the sample eluted into a larger volume of diluent. This procedure allows for detection of site-to-site variation in GCF volume, and provides a 300-400 microliter sample for analysis of lactate dehydrogenase (LDH), beta-glucuronidase (BG) and arylsulphatase (AS) activities by a standard (serum) spectrophotometric assay modified for increased sensitivity. The results indicate that although the standard assay for LDH (based on oxidation of NADH) was adequate for detecting low activity in GCF samples, the modification doubled the sensitivity and allowed the use of less sample volume, thereby providing additional material for other assays. The standard assay for BG based on phenolphthalein being generated from phenophthalein glucuronic acid was not adequate for use in GCF analysis. The modification used increased assay sensitivity five-fold and allowed smaller samples to be used. The serum assay for AS (conversion of nitrocatechol sulphate to nitrocatechol) was accurate to the lower limit of AS activity in GCF and could be used without modification. The results emphasize the need to evaluate critically standard spectrophotometric assays for sensitivity when studying physiologically-collected GCF.

Modulation of human T-cell suppressor activity by beta endorphin and glycyl-L-glutamine

beta-endorphin (10(-7) M) induced suppressor cell activity in human peripheral blood lymphocyte cultures comparable to that of concanavalin A (Con A) (60 micrograms/ml). beta-endorphin and Con A, when used together during the induction portion of the suppressor assays, displayed synergistic activity. In contrast, glycyl-L-glutamine, the carboxy terminal dipeptide of beta-endorphin, inhibited development of Con A induced suppressor activity. It appears that the previously reported suppressive effects of beta-endorphin on immune function may be achieved by activation of specific suppressor T cell populations.

The polyamines putrescine, spermidine and spermine in human gingival crevicular fluid

In human periodontal disease, there may be periods of exacerbation and remission. Definition of the homeostatic mechanisms in the periodontium may therefore be important in understanding the natural history of this disorder. The polyamines are biologically active amines involved in the regulation of cell growth, regeneration of tissue and modulation of inflammation. Their occurrence was examined in gingival crevicular fluid (GCF). Fifteen sites were evaluated in four patients with moderately advanced periodontitis before and after root planing and scaling, and 15 sites were evaluated in four patients with mild inflammatory gingivitis and no attachment loss. Polyamine analysis was by high-performance liquid chromatography. GCF from untreated sites in periodontitis patients contained the highest concentration of putrescine (10(4) greater than serum). This polyamine was detected in all periodontitis samples and 12 of 15 gingivitis samples. Significant differences were seen when the amount of putrescine/30 s sample was compared: periodontitis sites before treatment 1005.7 +/- 106.1 pmol; periodontitis sites after treatment 504.7 +/- 89.2 pmol; gingivitis sites 186.7 +/- 40.1 pmol. In contrast, spermidine and spermine were detected only occasionally. Thus putrescine may play an important homeostatic role in the periodontium.

Arylsulphatase activity in human gingival crevicular fluid

Arylsulphatase activity in fluid collected from non-inflamed (n = 5), gingivitis (n = 5) and periodontitis (n = 5) subjects was assayed. The mean volume activity for each group was: non-inflamed = 768 +/- 165 nm/ml per h; gingivitis = 2431 +/- 1118 nm/ml per h; periodontitis = 2860 +/- 1839 nm/ml per h. The mean total unit activity for each group was: non-inflamed = 0.326 +/- 0.076 nm; gingivitis = 1.394 +/- 0.411 nm; and periodontitis = 3.571 +/- 1.700 nm. Analysis of fluid from isolated sites in periodontitis suggests that reporting total unit activity (absolute amount of enzyme activity) is more meaningful than reporting volume activity (enzyme concentration) for arylsulphatase activity.

Immunosuppressive Effects of the Opiopeptins

The immune system has long been considered an organ system differing significantly from others in the immediacy of its regulation by the central nervous system. Whereas other organs have, to differing degrees, well characterized neural and hormonal afferent as well as efferent regulatory pathways, immune function has traditionally been viewed as an internally regulated effector system essentially devoid of CNS modulation with the possible exception of the CRF-ACTHcorticosteroid link. Such views were reinforced by Jerne’s natural antibody selection theory (Jerne, 1955), and the observed ability of immune elements to display significant levels of activity in varied in vitro assay systems (Nowell, 1960). Astute clinicians, however, have for centuries reported antecdotal evidence of increased disease susceptibility associated with diverse physiological and psychological stimuli (Shigami, 1919) including those of stress and emotional distress (Locke, 1982). Patients suffering stressful injury such as burns, and operative or accidental trauma, exhibit decreased immune responsiveness which is often well correlated with post-traumatic susceptibility to bacterial, viral and fungal infections (Constantian et al., 1977; Wolfe et al., 1981; Alexander, 1968; and Goodman et al., 1968). Cancer patients have generally suppressed immunocompetence and, conversely, a large body of experimental data indicates that stress reduces the rate of implanted tumor rejection (Visintaner et al., 1982), and increases tumor growth (Riley, 1981) along with other correlates of invasiveness (Shavit et al., 1983).