Filip Čulo

Prognostic significance of plasma prostaglandin E concentration in patients with head and neck cancer

SummaryPlasma prostaglandin E (PGE) levels were determined by radioimmunoassay in 53 patients with various stages (II, III, and IV) of hypoharyngeal and laryngeal sequamous cell carcinoma, in 12 non-cancer patients and in 10 healthy volunteers. The mean PGE concentration was somewhat higher in non-cancer patients (mean ± SD=34.6±5.37 pg/ml) than in healthy subjects (28.1±4.96 pg/ml). In spite of a high data variability, the mean preoperative PGE levels in cancer patients were proportional to the stage of the disease and higher than in non-cancer patients (41.2±19.7 pg/ml, 52.8±26.7 pg/ml and 82.0±34.9 pg/ml in stages II, III and IV respectively). The mean plasma PGE concentration significantly decreased for all tumour stages 15–30 days after surgical removal of the tumour, but rose again in some patients within 6–18 months after surgery. The incidence of tumour recurrences 6 and 18 months after surgery was significantly higher in patients with an increased preoperative PGE level (>43.3 pg/ml) than in those patients with a PGE level within the normal range (<43.3 pg/ml). The mortality was also higher in the former group, but the difference did not reach the level of significance. Similarly, the mean preoperative and most postoperative concentrations of PGE were significantly higher in patients in whom tumour recurred within 18 months than in tumour-free patients.

Anti-tumoral and anti-inflammatory effects of biological stains

The biological stains, methylene blue and its metabolite azure B, were evaluated as anti-tumor and anti-inflammatory agents. Azur B, administered in drinking water to tumor-bearing mice, inhibited the growth of transplanted tumors and the growth of primary tumors induced by methylcholanthrene. Inhibition of growth of primary tumors was observed only in female mice. Azure B also reduced the wet weight of carrageenin-induced granulomas in rats. Azure B, given intravenously to BCG-sensitized mice 15 minutes prior to challenge with lipopolysaccharide, decreased TNF production (to 10% of control values) and prevented death from endotoxic shock. Methylene blue decreased TNF production (to 50% of control values) but did not protect the animals from endotoxic shock. Our results suggest that some of the effects previously ascribed to methylene blue are probably mediated via its metabolite, i.e. azure B. Low toxicity and easy administration of the dyes explain their use in clinical settings.

Arachidonic Acid Metabolites and Sinonasal Polyposis. I. Possible Prognostic Value

PURPOSE The etiology of sinonasal polyps is sometimes obscure. This study was undertaken to evaluate the potential role of arachidonic acid metabolites (AAm) on recurrent polyposis. MATERIALS AND METHODS Tissue production of prostaglandin E2 (PGE2), 6-keto-prostaglandin F1-alpha (PGI2), thromboxane A2 (TxA2), and leukotriene C4 (LTC4) by nasal mucosa was determined by radioimmunoassay in 27 patients with sinonasal polyposis (SNp) and in 10 volunteers. RESULTS The group of patients with SNp with the evidence of recurrences in postoperative period (Group 1) showed significantly lower PGE2 concentrations than group of patients with SNp recurrences (Group 2). The differences in concentrations of PGI2 in mentioned groups were insignificant. In comparison with other groups, a group of patients who underwent surgery several times for SNp (Group 4) had a higher mean TxA2 concentration. The LTC4 concentrations were the highest in groups of patients where SNp recurrences were observed. When the incidence of polyposis recurrences (within 18 months after surgery) was correlated with the level of LTC4 production at the time of surgery, the rate of recurrence was significantly higher in patients with increased LTC4 level than in those with normal LTC4 levels. CONCLUSIONS LTC4 might have a prognostic value. The possible role of AAm in occurrence of SNp is apparent and suggests possible role for medical intervention.

Interference of anti-tumor and immunosuppressive effects of cyclophosphamide in tumor-bearing rats

SummaryAdult rats were given 105 or 106 Yoshida ascites sarcoma (YAS) cells IP and were treated with cyclophosphamide (CY) given IP in single doses of 20 mg/kg or 100 mg/kg, 2 or 5 days after YAS inoculation. Both the curative effect of CY and subsequent resistance to tumor challenge in rats that survived depended on the dose of injected tumor cells and on the dose and time of administration of CY. These three factors determined whether the hosts immune response to tumor antigens would develop and contribute to the overall anti-tumor effects of the chemotherapy. The curative effects of CY were significantly less pronounced in T-cell-deficient than in normal rats. Anti-tumor and immunosuppressive activities of CY exerted opposite influences on the ultimate result of the chemotherapy. Adverse immunosuppressive effects prevailed when the drug was administered early (2 days) after YAS inoculation. In this case the chemotherapy was less efficient and the surviving rats were susceptible to a subsequent tumor challenge. Further analysis showed that the injection of CY 2 days after inoculation of YAS antigens induced strong and specific immunologic tolerance to the tumor. In contrast, when a sufficient amount of tumor antigens (higher dose of tumor cells injected and CY injection delayed) elicited an anti-YAS immune response that was not suppressed by early injection of CY (CY administered 5 days after the tumor) effective eradication of tumor cells and anti-YAS resistance in cured animals were observed.

Cyclic adenosine 5′-monophosphate in synovial fluid of rheumatoid arthritis and osteoarthritis patients

The relationship between synovial fluid (SF) cAMP level and IL-18 and PGE2 SF levels in rheumatoid arthritis (RA) and osteoarthritis (OA) patients, and between SF cAMP level and disease as well as inflammatory activity in RA were investigated in 17 RA and 19 OA patients. Erythrocyte sedimentation rate (ESR), serum (S) C-reactive protein (CRP) level and SF IL-18 level were higher in RA than in OA patients. SF PGE2 level was similar in both groups. SF cAMP level was higher in OA than in RA patients. In RA patients, SF cAMP level showed negative correlation with Disease Activity Score including a 28-joint count and S CRP, ESR and SF IL-18 level. The results suggest that cAMP promotes anti-inflammatory response in RA and OA patients, which is higher in the latter. Promotion of anti-inflammatory response by cAMP elevating agents might be useful in the treatment of RA.

Lipid-bound sialic acid, prostaglandin e and histamine in head and neck cancer

Blood concentration of lipid-bound sialic acid (LBSA), prostaglandin E (PGE) and histamine were determined in 37 patients with carcinoma of hypopharynx and larynx (supraglottic and glottic), in 12 non-cancer patients and in 10 healthy subjects. The concentration of LBSA was significantly increased in 94.4% cancer patients preoperatively and fell to somewhat lower levels within 1 month after tumour resection. In patients with complete tumour resection and no tumour recurrences within 2 years, it steadily decreased thereafter, reaching normal levels within 6-24 months after surgery, whereas in patients with tumour recurrences or incomplete tumour resection it rose again within 6 months after tumour resection. Similarly, the concentration of PGE was significantly increased in about two thirds of cancer patients (67.6%) preoperatively, dropped significantly within 1 month after tumour resection and rose again in patients with tumour recurrences. Preoperative histamine concentration was decreased in 24.3% of cancer patients and postoperatively it rose both in patients with or without tumour recurrences.

Cell cooperation in abolition of tolerance to xenogeneic tumor

Abstract Thymectomized, lethally irradiated mice reconstituted with syngeneic bone marrow cells are tolerant to xenogeneic Yoshida ascites sarcoma (YAS). The tolerance was abolished by an injection of syngeneic normal spleen, thymus, or lymph node cells given simultaneously with YAS. Allogeneic and semiallogeneic spleen cells were ineffective. The YAS-rejecting mice produced specific anti-tumor antibodies. The serum of these mice transferred to tolerant T-cell-deficient mice protected the latter from inoculated YAS cells. These serum-protected mice were not able to resist the reinoculum of the tumor cells as the mice restored with lymphoid cells did. The latter mice rejected the YAS at the time when donor cells were practically absent in their lymphoid tissue. The low effective ratio of injected syngeneic lymphoid to tumor cells, efficiency of injected thymus cells, and other data led to the conclusion that transferred lymphoid cells did not act directly on tumor cells but through cooperation with host lymphoid cells. The cooperation of donor T- and host B-lymphocytes enabled the activation of the latter, and YAS cells were rejected.

The influence of cyclophosphamide on antitumor immunity in mice bearing late-stage tumors

Spleen cells from mice bearing late-stage methylcholanthrene-induced tumor did not show any tumor activity when mixed with tumor cells in Winns assay. Treatment of these mice with cyclophosphamide (CY) induced a tumor-inhibitory activity in spleen, occurring on day 7 after treatment, reaching its maximum on day 11 and disappearing by day 21. This antitumor activity could not be induced in control, tumor-free or T-deficient tumor-bearing mice. CY-induced tumor-inhibitory activity was immunologically specific, and mediated by Thy-1+, L3T4−, Ly-2+ cells. Contrary to spleen cells from untreated tumor-bearing mice, spleen cells from CY-treated tumor-bearing mice did not suppress the antitumor activity of immune spleen cells in Winns assay. However, in contrast to immune spleen cells, CY-induced tumor-inhibitory cells did not manifest antitumor activity when transferred systemically (i. v.) into T-cell-deficient tumor-bearing mice. Even more, spleen cells from CY-pretreated mice, harvested 7–15 days after the drug administration, partially suppressed the antitumor activity of concomitantly transferred spleen cells from specifically immune mice. Nevertheless, CY-pretreated mice manifested concomitant immunity, i.e. these mice exhibited higher resistance to a second inoculum of the same tumor than did nontreated mice or even mice with excised primary tumor.

The Influence of α-, β-, and γ-Melanocyte Stimulating Hormone on Acetaminophen Induced Liver Lesions in Male CBA Mice

Research over the past decade has indicated that melanocortin peptides are potent inhibitors of inflammation and a promising source of new anti-inflammatory and cytoprotective therapies. The purpose of the present paper is to compare protective effects of α-, β-, and γ-melanocyte stimulating hormone on acetaminophen induced liver lesions in male CBA mice. Acetaminophen was applied intragastrically in a dose of 150 mg/kg, and tested substances were applied intraperitoneally 1 hour before acetaminophen. Mice were sacrificed after 24 hours and intensity of liver injury was estimated by measurement of plasma transaminase activity (AST and ALT) and histopathological grading of lesions. It was found that α-, β-, and γ-MSH decrease intensity of lesions by both criteria in a dose-dependent manner.

The effect of interleukin 1α on acetaminophen-induced hepatotoxicity

Abstract The protective effect of interleukin 1α (IL-1α) in mice with acetaminophen (AAP)-induced hepatitis was investigated. IL-1α had a significant protective effect if given 2 or more hours (up to 24 hours) before AAP; it significantly reduced mortality of mice and decreased serum transaminase level. The maximal effect was obtained with the dose of 1000 U (166 mg/kg) IL-1α. Pretreatment with IL-1 significantly increased the synthesis of prostaglandin E2 (PGE2) in samples of liver tissue from AAP-treated mice, but had no effect on the synthesis of leukotriene C4 (LTC4). Pretreatment with indomethacin (IMC) did not abrogate significantly the protective effect of IL-1. Thus, the hepatoprotective effect of IL-1α can not be entirely explained by the stimulation of prostaglandin (PG) synthesis.