The Amount of Phosphorus in the Blood of Heroin Abusers Compared to that of Healthy Subjects.

BACKGROUND: The aim of the current retrospective study was to assess any difference in terms of serum phosphate (P) between heroin addicts and healthy subjects. METHODS: Between 2011 and 2012, under the authority of the Greek Organization Against Drugs (OKANA), 30 regular heroin addicts, 22 males and 8 females (Group A) participated at the study. Between 2010 and 2011, 30 healthy individuals, 22 males and 8 females (Group B), presented on an outpatient basis for either fatigue or common flu symptoms without fever at the 424 Military Hospital of Thessaloniki. RESULTS: No significant difference between group A and B, in terms of either age (p = 0.454, Mann-Whitney test) or male/female ratio (p = 0.573, Chi2 test), suggesting a homogeneity for the population of individuals participating in the study. The mean values of serum-P in group A and B were 3.47 ± 0.65 and 3.35 ± 0.58, respectively (p = 0.45, Mann Whitney test). CONCLUSIONS: The absence of statistical difference of serum-P between heroin addicts and healthy subjects as shown in our results should be confirmed in further studies.

Survival Fraction at 2 Gy and γH2AX Expression Kinetics in Peripheral Blood Lymphocytes From Cancer Patients: Relationship With Acute Radiation-Induced Toxicities.

PURPOSE: Predictive assays for acute radiation toxicities would be clinically relevant in radiation oncology. We prospectively examined the predictive role of the survival fraction at 2 Gy (SF2) and of γH2AX (double-strand break [DSB] DNA marker) expression kinetics in peripheral blood mononuclear cells (PBMCs) from cancer patients before radiation therapy. METHODS AND MATERIALS: SF2 was measured with Trypan Blue assay in the PBMCs from 89 cancer patients undergoing radiation therapy at 4 hours (SF2[4h]) and 24 hours (SF2[24h]) after ex vivo irradiation. Using Western blot analysis and band densitometry, we further assessed the expression of γH2AX in PBMC DNA at 0 hours, 30 minutes, and 4 hours (33 patients) and 0 hour, 4 hours, and 24 hours (56 patients), following ex vivo irradiation with 2 Gy. Appropriate ratios were used to characterize each patient, and these were retrospectively correlated with early radiation therapy toxicity grade. RESULTS: The SF2(4h) was inversely correlated with the toxicity grade (P=.006). The γH2AX-ratio(30min) (band density of irradiated/non-irradiated cells at 30 minutes) revealed, similarly, a significant inverse association (P=.0001). The DSB DNA repair rate from 30 minutes to 4 hours, calculated as the relative RγH2AX-ratio (γH2AX-ratio(4h)/γH2AX-ratio(30min)) showed a significant direct association with high toxicity grade (P=.01). CONCLUSIONS: Our results suggest that SF2 is a significant radiation sensitivity index for patients undergoing radiation therapy. γH2AX Western blot densitometry analysis provided 2 important markers of normal tissue radiation sensitivity. Low γH2AX expression at 30 minutes was linked with high toxicity grade, suggesting that poor γH2AX repair activity within a time frame of 30 minutes after irradiation predicts for poor radiation tolerance. On the other hand, rapid γH2AX content restoration at 4 hours after irradiation, compatible with efficient DSB repair ability, predicts for increased radiation tolerance.