Plasma (carotenoids, retinol, alpha-tocopherol) and tissue (carotenoids) levels after supplementation with beta-carotene in subjects with precancerous and cancerous lesions of sigmoid colon.

OBJECTIVES: (1) To compare tissue and plasma carotenoids status of healthy subjects and subjects with pre-cancer and cancer lesions; (2) to evaluate the effect of beta-carotene supplementation on the concentrations of other carotenoids in tissue (luteine + zeaxanthin, cryptoxanthin, lycopene, alpha-carotene) and in plasma and also retinol and alpha-tocopherol levels. DESIGN: Eighteen subjects were divided into three groups on the basis of colonoscopy and histological analytical findings: four healthy subjects (control group A); seven subjects affected by adenomatous polyps (group B with pre-cancer lesions); seven subjects suffering from colonic cancer (group C). Blood and colonic biopsy samples were taken (of colon and rectal mucosa) before and after beta-carotene supplementation in all subjects. Groups A and B received a daily dose of beta-carotene (30 mg/die) for 43 d. Group C's supplementation was terminated at the time which was performed, usually within 15 d. The tissue and plasma concentration of carotenoids, retinol and alpha-tocopherol were determined by high-performance liquid chromatography. RESULTS: The tissue concentrations of each carotenoid were similar in all the intestinal sites examined as regards groups A and B, although there was a high degree of intra individual variability within each group. Only beta-carotene made significant increases (P < 0.001) after supplementation. The subjects with cancer show tissue levels for each carotenoid lower than those of healthy subjects or subjects with polypous. The plasma levels of alpha-tocopherol did not change after supplementation while significant increases were noted of retinol, alpha-carotene (P < 0.01) and of beta-carotene (P < 0.001). CONCLUSIONS: The patients with colonic cancer seemed to undergo a significant reduction in their antioxidant reserves with respect to the normal subjects and or polyps. We can confirm that oral B-carotene supplementation induces also an increase in plasma alpha-carotene in all groups.

Antioxidant agents and colorectal carcinogenesis: role of beta-carotene, vitamin E and vitamin C.

In consideration of findings reported in the literature and of our study, we examined the correlation between antioxidants (beta-carotene, vitamin C, vitamin E) and colorectal carcinogenesis. Although diagnostic progress has been made in the last decades, no significant improvements in death rates have been achieved in the western world. Exogenous factors might be responsible for a complex alteration process of might be responsible for a complex alteration process of normal colonic mucosa into adenoma and carcinoma. Free radicals and reactive oxygen metabolites, due to increased production or to reduced inactivation, following a decrease in the antioxidant burden in the mucosa, might cause damage to DNA, thereby resulting in genetic alterations. This might represent the cause of the transformation process: normal mucosa --> adenoma --> carcinoma. In a prospective study, we observed a reduction of beta-carotene levels in normal colonic mucosa in patients with polyps and colorectal cancer. We also showed that beta-carotene supplementation raises levels of this micronutrient in the colonic mucosa of these patients. Findings from the literature and our trials show a significant decrease in the antioxidant capacity of colorectal mucosa in patients affected by colorectal cancer, although there is a significant interindividual variability. Such results suggest a possible chemopreventive role of antioxidant agents in colorectal cancer.

Accumulation of beta-carotene in normal colorectal mucosa and colonic neoplastic lesions in humans.

The quantity of beta-carotene (BC) accumulated in colonic polyps and colonic cancerous tissue in humans in situ was determined relative to the quantity accumulated in normal colon and rectal tissue. Serum concentration of BC, retinol, and alpha-tocopherol and tissue BC concentration were determined by high-performance liquid chromatography in samples obtained before and after oral supplementation with BC (30 mg/day). The serum BC and retinol concentrations significantly increased in response to supplementation in control, polyp, and cancer patients, but there was no change in serum alpha-tocopherol concentration. The BC concentration in tissue (colon, rectum, and tumor) of cancer patients was significantly less than that in tissue samples from control and polyp patients. Relative to baseline values, BC accumulated to a significant extent in tissues from all patients, including polyp and tumor tissue, during supplementation. The results indicate that BC does accumulate in colonic neoplastic tissue in humans and may potentially be utilized to augment cytotoxicity of chemotherapeutics or to prevent malignant transformation of cells.

Retroperitoneal malignant schwannoma. A case report.

The isolated retroperitoneal malignant schwannoma unassociated with Von Recklinghausen's disease is an unusual neoplasm, representing 0.01% of all retroperitoneal malignant neoplasms, with a poor prognosis, and an average survival at 5 years of 50% in patients treated by radical exeresis. At present, it is impossible, without histologic and immunohistochemical examinations, to differentiate it from other isolated retroperitoneal sarcomatous neoplasms. The authors report a case of retroperitoneal malignant schwannoma 20 cm in diameter in a 62-year-old woman surgically treated by radical exeresis. Postoperative complications were absent, and the patient, discharged from the hospital on the 12th postoperative day, died 8 months later of diffuse metastases, without local relapse. Despite the patient's short survival, the authors believe radical surgery to be the best therapeutic choice. Only surgery can establish a final diagnosis and can offer the best chance of survival and a significant and sometimes prolonged relief of symptomatology.

[Substernal goiter: new diagnostic methods and treatment]. / Il gozzo immerso: attualità terapeutiche sulla base dei nuovi mezzi diagnostici.

The authors report 47 cases of substernal goiters operated between 1971 and 1990. Forty-five patients had mediastinal-cervical-goiters (g.c.m.) and 2 had ectopic goiter (g.e.). Cervicotomy was performed in the 45 g.c.m., in 3 cases associated with sternal "split". The g.e. were treated with thoracotomy. Computed Tomography (TC) has been performed since 1984 in 26 patients; Magnetic Resonance (RM) since 1987 in 6 patients. The diagnostic accuracy for TC was 84.6% and 100% for MR on anatomical-topographic-definition, and 80.8% and 83.3% for presumptive diagnosis of nature, respectively. Considering the high diagnostic accuracy, the possibility to reconstruct the images in sagittal and coronal planes, the RM seems to be the elective diagnostic procedure for all substernal goiters.

[Esophageal manometry and pH-monitoring for surgical indications]. / La manometria e la pH-metria esofagea nell'indicazione chirurgica.

The Authors report a review of the data gathered by manometry and pH-metry in the functional esophageal diseases. Manometric and pH-metric patterns of gastro-esophageal reflux, Barrett esophagus, diverticula, achalasia, aspecific motility disorders and non-cardiac chest pain, are analyzed. Data conditioning the choice of surgical treatment in the literature and in the authors' experience are reported in detail.