Multivariate qualitative methodology for semi-quantitative information. A case study: Adulteration of olive oil with sunflower oil.

This paper proposes a strategy to assess the performance of a multivariate screening method for semi-quantitative purposes. The adulteration of olive oil with sunflower oil was considered as a case study using fluorescence spectroscopy and two-class Partial Least Squares Discriminant Analysis (PLS-DA). Building the proper screening methodology based on two-class multivariate classification model involve setting the cut-off value for the adulterated class (class 2). So, four classification models were established for four levels of adulterant (cut-off). Model validation involved calculating the main quality parameters (sensitivity, specificity and efficiency) and three additional semi-quantitative parameters (limit of detection, detection capability and unreliability region). The probability of successfully recognizing non-adulterated samples as such was set by the main performance parameters of the two-class model. However, the probability of successfully recognizing adulterated samples as such was more accurately extracted from the performance characteristic curves (PCC) curves instead of just from the sensitivity of the adulterated class. The main performance parameters of the PLS-DA models increased as the cut-off level increased although after a particular value the increase was less pronounced. As an example, when the cut-off was changed from 5% to 20%, sensitivity changed from 70 to 93%, specificity changed from 87 to 97%, and efficiency changed from 78 to 95%. The same can be stated for the semi-quantitative parameter's decision limit and detection capability, which moved from 0 to 1.6 and from 17.7 to 21.6 (% of adulterant), respectively.

Ozone Therapy as Adjuvant for Cancer Treatment: Is Further Research Warranted?

INTRODUCTION: This article provides an overview of the potential use of ozone as an adjuvant during cancer treatment. METHODS: We summarize the findings of the most relevant publications focused on this goal, and we include our related clinical experience. RESULTS: Over several decades, prestigious journals have published in vitro studies on the capacity of ozone to induce direct damage on tumor cells and, as well, to enhance the effects of radiotherapy and chemotherapy. Indirect effects have been demonstrated in animal models: immune modulation by ozone alone and sensitizing effect of radiotherapy by concurrent ozone administration. The effects of ozone in modifying hemoglobin dissociation curve, 2,3-diphosphoglycerate levels, locoregional blood flow, and tumor hypoxia provide additional support for potential beneficial effects during cancer treatment. Unfortunately, only a few clinical studies are available. Finally, we describe some works and our experience supporting the potential role of local ozone therapy in treating delayed healing after tumor resection, to avoid delays in commencing radiotherapy and chemotherapy. CONCLUSIONS: In vitro and animal studies, as well as isolated clinical reports, suggest the potential role of ozone as an adjuvant during radiotherapy and/or chemotherapy. However, further research, such as randomized clinical trials, is required to demonstrate its potential usefulness as an adjuvant therapeutic tool.

Ozone Therapy in the Management of Persistent Radiation-Induced Rectal Bleeding in Prostate Cancer Patients.

Introduction. Persistent radiation-induced proctitis and rectal bleeding are debilitating complications with limited therapeutic options. We present our experience with ozone therapy in the management of such refractory rectal bleeding. Methods. Patients (n = 12) previously irradiated for prostate cancer with persistent or severe rectal bleeding without response to conventional treatment were enrolled to receive ozone therapy via rectal insufflations and/or topical application of ozonized-oil. Ten (83%) patients had Grade 3 or Grade 4 toxicity. Median follow-up after ozone therapy was 104 months (range: 52-119). Results. Following ozone therapy, the median grade of toxicity improved from 3 to 1 (p < 0.001) and the number of endoscopy treatments from 37 to 4 (p = 0.032). Hemoglobin levels changed from 11.1 (7-14) g/dL to 13 (10-15) g/dL, before and after ozone therapy, respectively (p = 0.008). Ozone therapy was well tolerated and no adverse effects were noted, except soft and temporary flatulence for some hours after each session. Conclusions. Ozone therapy was effective in radiation-induced rectal bleeding in prostate cancer patients without serious adverse events. It proved useful in the management of rectal bleeding and merits further evaluation.

Long-term control of refractory hemorrhagic radiation proctitis with ozone therapy.

CONTEXT: Persistent or severe hemorrhagic radiation proctitis (HRP) has limited therapeutic options. OBJECTIVES: To describe our experience with ozone therapy (O3T) in the management of refractory HRP. METHODS: Patients (n=17; median age 69 years [range 42-80 years]) previously irradiated for prostate or uterine cancer and suffering persistent or severe HRP without response to conventional treatment were enrolled to receive an O3/O2 gas mixture via rectal insufflations and topical application of ozonized oil. Most of the patients (83%) had Grade 3 or Grade 4 toxicity. Median follow-up post-O3T was 40 months (range 3-56 months). RESULTS: Endoscopic treatments required were: 43 (median 1; range 0-10) pre-O3T; 17 (median 0; range 0-8; P=0.063) during O3T; and five (median 0; range 0-2; P=0.008) during follow-up. Hemoglobin levels were 10.35g/dL (7-14g/dL) pre-O3T and 13g/dL (9-15g/dL) (P=0.001) post-O3T. Median toxicity grades were 3 (range 2-4) pre-O3T, 1 (range 0-2; P<0.001) at the end of O3T, and 0 (range 0-1; P<0.001) at the last follow-up. CONCLUSION: Persistent advanced HRP was significantly improved with O3T. The addition of O3T can be useful as a complementary treatment in the long-term management of HRP and, as such, merits further evaluation.