Variability of TSNA in U.S. Tobacco and Moist Smokeless Tobacco Products.

Tobacco-specific nitrosamines (TSNAs) have been of concern to the public health community for decades and their reduction through agricultural practices, plant breeding, and tobacco processing has also been a decades-long industry effort. Despite those efforts, TSNAs, though lower, continue to be constituents of concern in tobacco products. This paper examines the TSNA levels of dark air-cured, dark fire-cured, and burley tobaccos purchased in the United States by U.S. Smokeless Tobacco Company LLC (USSTC) and of nine finished USSTC moist smokeless tobacco products. TSNA values of the incoming purchased tobaccos and the finished products showed considerable variability. For the incoming tobaccos, the coefficient of variation was generally more than 100 % for each tobacco type and for each of the measured TSNAs. The relative TSNA variability of the finished tobacco products was also considerable, averaging approximately 25 %. It was also found that the measured values for the finished products averaged well above the proposed FDA NNN proposed product standard of 1.0 µg/g dry weight. Because of the large variability in NNN values, products would have to average well below FDA's proposed product standard to be consistently compliant.

Novel approach for selective reduction of NNN in cigarette tobacco filler and mainstream smoke.

Research conducted during past decades to reduce the level of the tobacco specific nitrosamine N-nitrosonornicotine (NNN) and its precursor nornicotine in tobacco yielded identification of three tobacco genes encoding for cytochrome P450 nicotine demethylases converting nicotine to nornicotine. We carried out trials to investigate the effect of using tobaccos containing three non-functional nicotine demethylase genes on the selective reduction of NNN in cigarette tobacco filler and mainstream smoke. Our results indicate that the presence of non-functional alleles of the three genes reduces the level of nornicotine and NNN in Burley tobacco by 70% compared to the level observed in currently available low converter (LC) Burley tobacco varieties. The new technology, named ZYVERT™, does not require a regular screening process, while a yearly selection process is needed to produce LC Burley tobacco seeds for NNN reduction. The reduction of NNN observed in smoke of blended prototype cigarettes is proportional to the inclusion level of tobacco having ZYVERT™ technology. Inclusion of Burley tobacco possessing the new trait into a typical American blend resulted in a selective reduction of NNN in cigarette smoke, while the levels of other Harmful and Potentially Harmful Constituents (HPHC) currently in the abbreviated list provided by the US Food and Drug Administration are statistically equivalent in comparison with the levels obtained in reference prototype cigarettes containing LC Burley.

Reactive oxygen species, antioxidant mechanisms and serum cytokine levels in cancer patients: impact of an antioxidant treatment.

OBJECTIVE: So far, it is not well established whether oxidative stress found in cancer patients results from an increased production of oxidants in the body or from a failure of physiological antioxidant systems. To further investigate this question we have assessed the blood levels of reactive oxygen species as a marker of free radicals producing oxidative stress and the most relevant of the physiological body enzymes counteracting reactive oxygen species, namely glutathione peroxidase and superoxide dismutase. Serum levels of proinflammatory cytokines and IL-2 were also investigated. All these parameters were studied in relation to the clinically most important index of disease progression, namely Performance Status (ECOG PS). We also tested the reducing ability of different antioxidant agents on reactive oxygen species levels by measuring the increase in glutathione peroxidase activity, and the reduction of serum levels of IL-6 and TNF. DESIGN, SETTING AND SUBJECTS: We carried out an open non randomized study on 28 advanced stage cancer patients (stage III, 10.7%, and stage IV, 89.3%) with tumours at different (8) sites: all were hospitalized in the Medical Oncology Dept, University of Cagliari Interventions. The patients were divided into 5 groups and a different antioxidant treatment was administered to each group. The selected antioxidants were: alpha lipoic acid 200 mg/day orally, N-acetylcysteine 1800 mg/day i.v. or carboxycysteine-lysine salt 2.7 g/day orally, amifostine 375 mg/day i.v., reduced glutathione 600 mg/day i.v., vitamin A 30000 IU/day orally plus vitamin E 70 mg/day orally plus Vitamin C 500 mg/day orally. The antioxidant treatment was administered for 10 consecutive days. RESULTS: Our results show that all but one of the antioxidants tested were effective in reducing reactive oxygen species levels and 2 of them (cysteine-containing compounds and amifostine) had the additional effect of increasing glutathione peroxidase activity. Comprehensively, the "antioxidant treatment" was found to have an effect both on reactive oxygen species levels and glutathione peroxidase activity. The antioxidant treatment also reduced serum levels of IL-6 and TNF. Patients in both ECOG PS 0-1 and ECOG PS 2-3 responded to antioxidant treatment.

Serum values of proinflammatory cytokines are inversely correlated with serum leptin levels in patients with advanced stage cancer at different sites.

Leptin is a recently identified hormone produced by the adipocyte ob gene which acts as a negative feedback signal critical to the normal control of food intake and body weight. A number of proinflammatory cytokines, such as interleukin 6, tumor necrosis factor alpha, and interferon gamma, have been proposed as mediators of cancer cachexia; these data suggest that abnormalities in leptin production/release or in its feedback mechanism play a role in cancer patients. We therefore studied the relationship between serum leptin and serum cytokines interleukin 6 and tumor necrosis factor alpha levels in advanced-stage cancer patients. Twenty-nine advanced stage cancer patients (all but one stage IV) with tumors at various sites were included in the study. A direct correlation between body mass index and serum leptin levels was found both in cancer patients and in healthy individuals. The serum levels of interleukin 6 were significantly higher in cancer patients than in healthy individuals. In cancer patients an inverse correlation was found between serum levels of leptin and proinflammatory cytokines. There was an inverse correlation between the Eastern Cooperative Oncology Group performance status scale and serum levels of leptin. Regarding survival, patients with very high serum levels of proinflammatory cytokines and very low levels of leptin had very short survival. Although obtained in a cancer patient population not overtly cachectic, our results provide further evidence that a simple dysregulation of leptin production and/or release cannot be involved in cancer-associated pathophysiological changes leading to cachexia.

Immunotherapy (recombinant interleukin 2), hormone therapy (medroxyprogesterone acetate) and antioxidant agents as combined maintenance treatment of responders to previous chemotherapy.

An open, non-randomized phase II study was carried out including all patients treated with whatever chemotherapy or combined modality regimen for whatever cancer who were in clinical objective response or stable disease (SD) for more than three months, to receive maintenance treatment with recombinant interleukin-2 (rIL-2) plus medroxyprogesterone acetate (MPA) plus antioxidant agents alpha-lipoic acid (ALA) and N-acetyl cysteine (NAC). The main study endpoints were clinical outcome and toxicity. The secondary endpoints were effects of treatment on cancer-related anorexia/cachexia syndrome (CACS) symptoms, on serum levels of proinflammatory cytokines, IL-2, C-reactive protein (CRP) and leptin as well as the evaluation of quality of life (QL). rIL-2 was administered at a dose of 1.8 MIU subcutaneously three times/week on alternate days for the first two weeks of every month and MPA was given orally at a dose of 500 mg once a day at alternate days without interruption. ALA 300 mg/day orally and NAC 1800 mg/day orally were also administered. The treatment was administered until progression of disease or appearance of toxicity. From July 1998 to May 2000, 16 patients were enrolled in the study (M/F ratio: 15/1; mean age: 62 years, range 45-71). The median duration of maintenance treatment was 10 months (range 5-22). The response to maintenance treatment at September 2000 was: CR (persistent throughout the treatment) 4 patients (25%); SD 1 patient (6.2%); PD 11 patients (68.8%). The median duration of response was 9.8 months (range: 5-22+). The median follow-up duration was 19 months (range: 8-102). The median OS was not reached. The median PFS was 14 months (range 1-29). The 1-year survival rate was 25%. At September 2000, 9 patients are still surviving. No grade 3/4 toxicity was observed. One Grade 2 skin toxicity was observed and Grade 1: 2 fever, 2 thrombocytopenia, 1 neutropenia and 1 skin were observed. The ECOG PS did worsen significantly, the body weight and BMI increased significantly after treatment, whereas the appetite did not change significantly. The QL evaluation showed a significant amelioration of cognitive functions and a borderline significant amelioration of emotional functions after treatment, whereas a borderline worsening of dyspnea was observed. The absolute lymphocyte count increased significantly after the maintenance treatment, as well as the serum IL-2, TNFalpha decreased at borderline statistical significance; the serum levels of leptin did not change significantly. The evaluation of patient subgroups showed that responders/survivors had a pattern superimposable to that of whole patient population, the patients who rapidly progressed and died exhibited no significant changes of these parameters during treatment. The results of the present study suggest that the host immune response, evaluated by several parameters, after IL-2 administration, (e.g. lymphocytosis), are worth further study as potential markers for the major end points of cancer treatment, i.e. OS and QL, in an adequate number of patients.

Serum levels of leptin and proinflammatory cytokines in patients with advanced-stage cancer at different sites.

Leptin is a recently identified hormone produced by the adipocyte ob gene which acts as a negative feedback signal critical to the normal control of food intake and body weight. A number of proinflammatory cytokines, such as interleukin (IL) 1alpha, IL-6, tumor necrosis factor (TNF) alpha and interferon (IFN) gamma, have been proposed as mediators of cancer cachexia. These data suggest that abnormalities in leptin production/release or in its feedback mechanism play a role in cancer patients. To elucidate this we studied the relationship between total serum leptin and serum cytokines IL-1alpha, IL-6, TNFalpha as well as the production of leptin and cytokines by peripheral blood mononuclear cells (PBMC) isolated from cancer patients. Sixteen advanced cancer patients (mainly stage IV) with tumors at different sites were included in the study. The serum levels of leptin in cancer patients were significantly lower than those of healthy individuals at all times (7 a.m., noon, 3 p.m.). No significant differences were found in circadian rhythm between patients and controls. Serum levels of IL-1alpha, IL-6, and TNFalpha were significantly higher in cancer patients than in healthy individuals. An inverse correlation between serum levels of leptin and IL-6 was found in cancer patients. The production in culture of leptin by unstimulated PBMCs and those stimulated by phytohemagglutinin M or by phorbol myristate acetate isolated from cancer patients was very low; no differences were observed in comparison with leptin production by PBMCs from healthy individuals.

Characterization of a Diffusible Signal Capable of Inducing Defense Gene Expression in Tobacco.

Treatment of tobacco (Nicotiana tabacum) cell-suspension cultures with cryptogein, an elicitin protein from Phytophthora cryptogea, resulted in the release of a factor(s) that diffused through a 1000-D cutoff dialysis membrane and was capable of inducing sesquiterpene cyclase enzyme activity (a key phytoalexin biosynthetic enzyme in solanaceous plants) when added to fresh cell-suspension cultures. The diffusible factor(s) was released from cells over a 20-h period and induced a more rapid induction of cyclase enzyme activity than did direct treatment of the cultures with pure elicitin protein. The diffusible factor also induced a more rapid accumulation of transcripts encoding for sesquiterpene cyclase, acidic and basic chitinase, and hsr203 (a putative hypersensitive response gene) than did elicitin treatment. The diffusible factor(s) was resistant to protease, pectinase, Dnase, and RNase treatments, was not extractable into organic solvents, and was not immunoprecipitable when challenged with polyclonal antibodies prepared against elicitin protein. The diffusible factor(s) could not induce the release of more factor, suggesting that it was a terminal signal. These results are consistent with the notion that cells directly challenged or stimulated by pathogen-derived elicitors release diffusible secondary signal molecules that orchestrate the induction of complementary defense responses in neighboring cells.