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Background: Abnormally low plasma levels of coenzyme Q10 (CoQ10) have been found in patients with cancer of the breast, lung, or pancreas. Objective: A prospective study of patients with melanoma was conducted to assess the usefulness of CoQ10 plasma levels in predicting the risk of metastasis and the duration of the metastasis-free interval. Methods: Between January 1997 and August 2004, plasma CoQ10 levels were measured with high-performance liquid chromatography in 117 consecutive melanoma patients without clinical or instrumental evidence of metastasis according to American Joint Committee on Cancer criteria and in 125 matched volunteers without clinically suspect pigmented lesions. Patients taking CoQ10 or cholesterol-lowering medications and those with a diagnosis of diabetes mellitus were excluded from the study. Multiple statistical methods were used to evaluate differences between patients and control subjects and between patients who did (32.5%) and did not (67.5%) develop metastases during follow-up. Results: CoQ10 levels were significantly lower in patients than in control subjects (t test: P < .0001) and in patients who developed metastases than in the metastasis-free subgroup (t test: P < .0001). Logistic regression analysis indicated that plasma CoQ10 levels were a significant predictor of metastasis (P = .0013). The odds ratio for metastatic disease in patients with CoQ10 levels that were less than 0.6 mg/L (the low-end value of the range measured in a normal population) was 7.9, and the metastasis-free interval was almost double in patients with CoQ10 levels 0.6 mg/L or higher (Kaplan-Meier analysis: P < .001). Limitations: A study with a larger sample, which is currently being recruited, and a longer follow-up will doubtlessly increase the statistical power and enable survival statistics to be obtained. Conclusions: Analysis of our findings suggests that baseline plasma CoQ10 levels are a powerful and independent prognostic factor that can be used to estimate the risk for melanoma progression. [Copyright &y& Elsevier]

The possible degradation of the tumor antigen epitope gp100280–288 (YLEPGPVTA) in the presence of the monocyte-like line U937, and the effect of degradation on the in vitro-measured immune recognition, were investigated by chromatographic techniques and immunological assays. Results indicate a rapid hydrolysis of the substrate in the presence of the model cells, which is consistent with the hypothesis that degradation of gp100280–288 is caused by the activity of U937-expressed enzymes, specifically amino- and carboxypeptidases. On the other hand, these results do not support the involvement of other enzymes known to be expressed by U937 cells. From a functional point of view, these data indicate that the degradation of gp100280–288 severely hampered recognition by specific CTL clones. The results obtained may provide a model for epitope degradation by the antigen-presenting cells found in defined anatomical compartments and may, at least in part, account for the low activity of peptide-based antineoplastic vaccines, as well as for the transience of the effects of subcutaneously administered peptides in general. [Copyright &y& Elsevier]

Objectives: We analyzed the relationships between sudden sensorineural hearing loss (SSNHL) and serum levels of fatty acids, total cholesterol, low-density lipoproteins (LDLs), and the antioxidant coenzyme Q10., Methods: Forty-three patients with SSNHL and 43 healthy subjects were enrolled in the study. The main outcome measures were serum levels of fatty acids, coenzyme Q10, total cholesterol, and LDLs., Results: On univariate logistic regression analysis, high levels of total cholesterol (p < 0.001), LDLs (p = 0.024), behenic acid (p < 0.001), docosahexaenoic acid (p < 0.001), linolenic acid (p = 0.017), and oleic acid (p < 0.001) and low levels of coenzyme Q10 (p < 0.001) and nervonic acid (p < 0.001) were associated with an elevated risk of SSNHL. On multivariate analysis, only hypercholesterolemia (p = 0.15) and low levels of coenzyme Q10 (p = 0.02) and nervonic acid (p = 0.005) were significantly associated with SSNHL., Conclusions: This is the first report of low serum levels of nervonic acid as an independent risk factor for SSNHL. Considering that hypercholesterolemia, high serum levels of LDL, and low serum levels of the antioxidant coenzyme Q10 were associated with SSNHL as well, we hypothesize that saturated fatty acids may play a role in determining the dysmetabolic state in a subset of SSNHL patients. Together, these findings suggest that not only total cholesterol and LDL levels, but also fatty acid determination, may help identify SSNHL patients with cardiovascular risk factors.

Early surgical intervention remains the most successful therapy for melanoma. Despite better outcomes observed in soft tissue and lymph node metastases, the results of pharmacological therapies are still disappointing. Currently, there is no standard adjuvant therapy for melanoma. Low concentrations of coenzyme Q10 have been demonstrated in melanoma cell lines and in sera of melanoma patients. These data and the results of clinical trials of patients with other advanced cancers prompted this study of the long-term administration of an optimized dose of recombinant interferon alpha-2b and coenzyme Q10 to patients with stage I and II melanoma. A 3-year trial envisaging uninterrupted treatment with low-dose recombinant interferon alpha-2b (9 000 000 000 IU weekly) administered twice daily and coenzyme Q10 (400 mg/day) was conducted in patients with stage I and II melanoma (American Joint Committee on Cancer criteria 2002) and surgically removed lesions. Treatment efficacy was evaluated as incidence of recurrences at 5 years. All patients completed the treatment and the follow-up. Significantly different rates of disease progression were observed in the interferon+coenzyme Q10 and the interferon group for both stages. No patient withdrew from the study owing to side effects. Long-term administration of an optimized dose of recombinant interferon alpha-2b in combination with coenzyme Q10 seemed to induce significantly decreased rates of recurrence and had negligible adverse effects. A survival study could not be undertaken owing to the small patient sample and the short duration of follow-up.

Experimental hyperoxia represents a suitable in vitro model to study some pathogenic mechanisms related to oxidative stress. Moreover, it allows the investigation of the molecular pathophysiology underlying oxygen therapy and toxicity. In this study, a modified experimental set up was adopted to accomplish a model of moderate hyperoxia (50% O(2), 96 h culture) to induce oxidative stress in the human leukemia cell line, U-937. Spectrophotometric measurements of mitochondrial respiratory enzyme activities, NMR spectroscopy of culture media, determination of antioxidant enzyme activities, and cell proliferation and differentiation assays were performed. The data showed that moderate hyperoxia in this myeloid cell line causes: i) intriguing alterations in the mitochondrial activities at the levels of succinate dehydrogenase and succinate-cytochrome c reductase; ii) induction of metabolic compensatory adaptations, with significant shift to glycolysis; iii) induction of different antioxidant enzyme activities; iv) significant cell growth inhibition and v) no significant apoptosis. This work will permit better characterization the mitochondrial damage induced by hyperoxia. In particular, the data showed a large increase in the succinate cytochrome c reductase activity, which could be a fundamental pathogenic mechanism at the basis of oxygen toxicity.

Chronic hypoxia (CH) is believed to induce myocardial protection, but this is in contrast with clinical evidence. Here, we test the hypothesis that repeated brief reoxygenation episodes during prolonged CH improve myocardial tolerance to hypoxia-induced dysfunction. Male 5-week-old Sprague-Dawley rats (n = 7-9/group) were exposed for 2 weeks to CH (F(I)O(2) = 0.10), intermittent hypoxia (IH, same as CH, but 1 hr/day exposure to room air), or normoxia (N, F(I)O(2) = 0.21). Hearts were isolated, Langendorff perfused for 30 min with hypoxic medium (Krebs-Henseleit, PO(2) = 67 mmHg), and exposed to hyperoxia (PO(2) = 670 mm Hg). CH hearts displayed higher end-diastolic pressure, lower rate x pressure product, and higher vascular resistance than IH. During hypoxic perfusion, anaerobic mechanisms recruitment was similar in CH and IH hearts, but less than in N. Thus, despite differing only for 1 hr daily exposure to room air, CH and IH induced different responses in animal homeostasis, markers of oxidative stress, and myocardial tolerance to reoxygenation. We conclude that the protection in animals exposed to CH appears conferred by the hypoxic preconditioning due to the reoxygenation rather than by hypoxia per se.