tumors arising from the breast, prostate, thyroid, lung, and kidney possess a special Yorkshire Cancer Research Campaign (YCRC), propensity to spread to bone. Breast carcinoma, the most prevalent malignancy, Department of Clinical Oncology, Weston Park causes the greatest morbidity. Of great clinical importance is the observation that Hospital, Sheffield, United Kingdom.metastatic bone disease may remain confined to the skeleton. In these patients, the decline in quality of life and eventual death is due almost entirely to skeletal complications and their subsequent treatment. Bone pain is the most common complication of metastatic bone disease, resulting from structural damage, periosteal irritation, and nerve entrapment. Recent evidence suggests that pain caused by bone metastasis may also be related to the rate of bone resorption. Hypercalcemia occurs in 5-10% of all patients with advanced cancer but is most common in patients with breast carcinoma, multiple myeloma, and squamous carcinomas of the lung and other primary sites. Pathologic fractures are a relatively late complication of bone involvement. The clinical courses of breast and prostate carcinoma are relatively long, with a median survival of 2-3 years. For patients with breast carcinoma, good prognostic factors for survival after the development of bone metastases are good histologic grade, positive estrogen receptor status, bone disease at initial presentation, a long disease free interval, and increasing age. In addition, patients with disease that remains confined to the skeleton have a better prognosis than those with subsequent visceral involvement. For patients with prostate carcinoma, adverse prognostic features include poor performance status, involvement of the appendicular skeleton and visceral involvement, whereas for patients with multiple myeloma, the levels of serum b 2 -microglobulin and lactate dehydrogenase and the immunologic phenotype are the most important factors. These prognostic factors may be useful in planning the rational use of bisphosphonates in the treatment of advanced cancer. T he skeleton is the most common organ to be affected by metastatic cancer. Bone metastases from carcinomas of the breast, lung, prostate, kidney, and thyroid are most frequent 1 (Table 1). The prevalence of skeletal disease is greatest in breast and prostate carcinoma, reflecting both the high incidence and the relatively long clinical courses of these tumors. These two cancers probably account for more than 80% of cases of metastatic bone disease. In breast carcinoma, the incidence of bone metastases has been found to be significantly higher in association with tumors that produce parathyroid hor- tastases are more often associated with poorly differentiated tumors. enced by molecular and cellular biologic characteristics of both the
The kinetics of the autoxidation reaction of tartaric acid in an air-saturated solution in the presence of Fe(II) show autocatalytic behavior with distinct initiation, propagation, and termination phases. The initiation phase, which involves activation of dissolved oxygen, decreases with increasing pH, over the test range of pH of 2.5–4.5, indicating that activation of oxygen is catalyzed by an Fe(II)–tartrate complex. The autocatalytic nature of this reaction indicates the presence of a catalytic intermediate that is produced during the initiation phase and regenerated during the propagation phase. The addition of catalase, as well as direct measurements, provided evidence of the presence and kinetic action of hydrogen peroxide as one of the intermediates. Direct addition of hydrogen peroxide resulted in shortening of the initiation stage and the propagation phase with similar rates as in the autoxidation reaction at low pH. The propagation is approximately a zero order reaction with respect to oxygen and iron. The kinetic analysis suggests that an intermediate catalytic complex(s) involving a ferryl ion (FeO2+) controls the rate of the propagation reaction. The Fe(III) formation shows autocatalytic behavior that mirrors the dissolved oxygen consumption patterns under all pH conditions studied. At pH values of 2.5 and 3.0, Fe(III) accumulated to a maximum, before it was partially consumed. This maximum coincided with the depletion of dissolved oxygen. The consumption of Fe(III), or the reduction of Fe(III) back to Fe(II), reflects the catalytic nature of Fe(II) and the essential role of tartaric acid in the initiation phase of Fenton’s original reaction.
The kinetics of autoxidation in wine begins with Fenton (1876) who observed that tartaric acid could be oxidized in the presence of iron without peroxide if left in air. Rodopulo (1951) demonstrated that iron tartrate complexes added to wine promoted more extensive oxygen consumption than the molar equivalent of inorganic ferrous or ferric salts. The role of iron complexes in the activation of oxygen, the formation of reactive oxygen species and the initiation of autoxidation are crucial for understanding wine oxidation kinetics. Mechanisms based on hydroxyl radicals versus the ferryl species are likely to have different oxidation products of wine components based on pH effects. The ferryl ion, hydroxyl radical, and tartaric acid radical are proposed as key intermediates in the proposed general mechanism for hydrogen peroxide formation and the autoxidation of wine components. A quantitative kinetic description is presented for the autoxidation of tartaric acid and extended to other acid components as potential ligands. This chapter explores the theoretical considerations of iron complexes formation, oxygen activation, an autoxidative mechanism, and experimental measurements of tartaric acid oxidation as the basis of autoxidation in wine.
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