Testosterone concentration is increased in whole saliva, but not in ultrafiltrate, after toothbrushing.

The concentration of testosterone in whole saliva is significantly increased (by 9%) after toothbrushing. In ultrafiltrates of saliva collected at the same time as the whole saliva, testosterone concentrations after toothbrushing were unchanged. In 88% of the 162 whole-saliva specimens, but not in the ultrafiltrates, we also measured higher hemoglobin concentrations after toothbrushing. We conclude that the increase of testosterone in whole saliva after toothbrushing can be attributed to a protein-bound fraction. For analytes that are bound to serum proteins, salivary measurements can give spurious results. This problem can be avoided by using as a diagnostic medium an ultrafiltrate of saliva collected directly in the mouth.

Cotinine in an ultrafiltrate of saliva.

BACKGROUND: We have developed a device for the simplified collection of a prepurified sample of saliva in the mouth. METHOD: The device is based on the principle of an osmotic pump and accumulated about 1.2 ml of an ultrafiltrate of saliva within 8 min. We have investigated the ultrafiltrate for its utility as a biological medium in the evaluation of cigarette smoking status. RESULTS: (a) In 58 matched samples from 13 subjects, the correlation coefficient for the cotinine concentration in the saliva and the ultrafiltrate was 0.95; (b) in matched plasma and ultrafiltrate samples from 27 smokers, the correlation coefficient for the cotinine concentrations was 0.96 with plasma containing 1.2 times the ultrafiltrate mean; (c) in a nonsmoker, elevated cotinine levels could be detected in the ultrafiltrate more than 24 hr after smoking 2 cigarettes, and the pattern of rise and decrease reflected that in whole saliva; and (d) in a habitual smoker; the mean cotinine concentration in the ultrafiltrate was 157 ng/ml (SD +/- 25.7 ng/ml) during a period of smoking 15 cigarettes per day and dropped to a mean of 47 ng/ml (SD +/- 10.5) when smoking was reduced to 5 cigarettes per day; after cessation of smoking, detectable concentrations of cotinine persisted for up to 5 days. CONCLUSION: The device facilitated the aesthetic, noninvasive collection of a biological sample useful in the validation of smoking status.

Rapid solid-phase immunoassay for 6-keto prostaglandin F1 alpha on microplates.

We describe, for the measurement of 6-keto prostaglandin F1 alpha in biological media, a solid-phase immunoassay with immobilized antibodies that requires a total processing time of less than 2 h with hands-on time less than 30 min for 40 samples. The method combines the convenience of the microplate format with the sensitivity of radiolabeled prostaglandin derivatives as tracers in a competitive immunoassay. The intra- and interassay variations at 50% displacement of the radiolabeled prostaglandin derivative as tracer were 9.0% and 11.8%, respectively. At 50% displacement of the radiolabeled tracer, the sensitivity is about 20 pg per well. Optimal incubation time is between 60 and 90 min. Nonspecific binding was less than 1% if about 8 pg of tracer (approximately 25,000 counts/min per well) was used. Inhibition curves of samples in different dilutions were parallel to standard curves. The variation of bound radiolabeled prostaglandin derivative within the wells of one microplate (n = 96) was less than 3%. Human plasma samples and medium from tissue culture assayed for 6-keto prostaglandin F1 alpha correlated well with results obtained with a solid-phase assay based on use of magnetic particles (r = 0.99, n = 24 for culture-medium samples; r = 0.99; n = 26 for plasma samples.

Potentiation of nitrogen mustard cytotoxicity by disulfiram, diethyldithiocarbamic acid, and diethylamine in mice.

Disulfiram (DSF) and its metabolites, diethyldithiocarbamic acid (DDC) and diethylamine (DEA), were studied as pretreatments in combination with the alkylating agent nitrogen mustard (HN2) on the cytotoxicity of HN2 against both leukemia cells and normal hematopoietic stem cells. Both time intervals and dose relationships were examined. DSF showed a substantial potentiation of HN2 cytotoxicity against murine AKR leukemia cell spleen colony-forming units (LCFU) when given i.p. between 15 to 30 min prior to HN2 i.v. treatment. For 3 mg DSF/mouse pretreatment, leukemia LCFU survival was about 10(-6) whereas it was about 10(-2) for HN2 alone. The extent of this potentiation decreased as the time between treatments increased. Significant potentiation was noted even when a low dose of DSF (0.25 mg/mouse) was administered 15 min before HN2. However, DSF had little if any effect on the modulation of HN2 cytotoxicity to normal hematopoietic cell spleen colony-forming units (NCFU). DDC showed an increasing potentiation of HN2 cytotoxicity against LCFU when given i.p. prior to HN2 i.v. treatment. The maximum effect was noted between 2 and 4 h with a surviving fraction for LCFU between 10(-5) and 10(-6) for 20 mg/mouse DDC pretreatment. The extent of this effect then decreased as the time interval increased beyond 4 h, but it was still significant for the 24-h interval. This pronounced potentiation effect was dose dependent for DDC. The compound exhibited a protective effect against HN2 cytotoxicity to NCFU when given 15 min before HN2. This protection decreased with increased time interval. DEA (20 mg/mouse) did not show a significant potentiation of HN2 cytotoxicity against LCFU when administered i.p. prior to HN2. Also, DEA did not show any significant protection of NCFU.

Potentiation of nitrogen mustard cytotoxicity to leukemia cells by sulfur-containing compounds administered in vivo.

Fifteen sulfur-containing compounds were examined for their ability to both protect normal hematopoietic stem cells (NCFU) from the cytotoxic effect of nitrogen mustard (HN2), and potentiate the cytotoxicity of HN2 to AKR leukemia cells (LCFU). All except four agents demonstrated some protection of NCFU with WR-2721 being most active. Five of the agents were also protective for LCFU with cysteine and glutathione being most active. However, a number of agents potentiated the cytotoxicity of HN2 to LCFU, the most active being disulfiram and AET followed by cysteamine, DMSO, WR-638, and WR-3689. The dose-response relationship for the potentiation was defined for DMSO. A second leukemia model, L1210, was also studied for potentiation of HN2 cytotoxicity by four of the most active agents--WR-2721, AET, DMSO, and disulfiram. The first two agents showed no effect (either protection or potentiation) when given either 15 min or 6 hr before HN2 administration. The last two agents, however, potentiated the cytotoxicity to a level similar to that found with the AKR leukemia.

Dose and interval relationship for the interaction of WR-2721 and nitrogen mustard with normal and malignant cells.

The protective effect of WR-2721 on nitrogen mustard (HN2) cytotoxicity against hematopoietic stem cells as well as the potentiation effect previously noted against leukemia cells was further examined for dose and interval dependency for these opposite effects. For AKR leukemia cells, a dose dependent potentiation of HN2 cytotoxicity was noted with WR-2721. The magnitude of the potentiation was about 10-fold with 5 mg/mouse WR-2721 and nearly 100-fold at 10 mg/mouse. Interval studies showed maximum potentiation occurred when WR-2721 was given close in time to HN2 and decreased in magnitude as the interval between the agents increased. However, a pronounced potentiation of cytotoxicity was also found when HN2 followed WR-2721 by 4 to 12 hr. For hematopoietic stem cells, a protective effect of WR-2721 on HN2 cytotoxicity was observed. This effect decreased rapidly with interval between the agents with no protection noted for an interval of 6 hr. These results indicate that agents like WR-2721 may have an important therapeutic role in chemotherapy.