[The Implications of Primary Tumor Resection during Recent Chemotherapy of Unresectable Colon Cancer].

Some patients with unresectable colorectal cancer can be treated by chemotherapy leaving the primary tumor unresected, but indications and implications of a later resection of the primary tumor (RPT) are often controversial. We investigated 5 patients whose primary tumors were resected during chemotherapy, either panitumumab or bevacizumab. The median age of these patients was 63 years and all were men. The unresectable disease was liver metastases in 4 patients and a primary tumor in 2 patients. A diverting stoma was constructed before initiation of chemotherapy in 2 patients. The median interval until RPT was 8.3 months and the reasons for resection were the appearance of obstructive symptoms in 3 patients and a desire for stoma closure in 2 patients. The size of the primary tumor had decreased until RPT in all patients. RPT was performed successfully in all patients, but 2 of the 3 operations that were initiated laparoscopically had to be converted to open surgery. Intensive chemotherapy was resumed in all patients and median survival after RPT was 19 months, including a patient whose liver metastasis was also resected later. RPT can relieve obstructive symptoms and close stomas. Because intensive chemotherapy is still possible and a lengthy survival can be expected after RPT, it should be considered not merely as a palliative option but also as a treatment strategy.

Selective, sensitive and fluorometric determination of urinary cytosine with 4-trifluoromethylbenzamidoxime and N,N-dimethylformamide.

BACKGROUND: Cytosine in urine is one of the biomarkers for the diagnosis of metabolic immunodeficiency. It has been mentioned that a high level of cytosine is found in urine of children having immunodeficiency. In this study, we have developed a fluorescence (fluorescence) derivatization reaction of cytosine using 4-trifluoromethylbenzamidoxime (4-TFMBAO) as a fluorogenic reagent. METHODS: In this reaction, cytosine was mixed with 4-TFMBAO, K3[Fe(CN)6], N,N-dimethylformamide (DMF) and KOH in an aqueous solution. The mixture was heated at 100°C for 20 min. The fluorescence intensity of the mixture was measured with a spectrofluorometer. RESULTS: Under the optimized reaction conditions, a strong fluorescence was produced only from cytosine amongst 62 compounds including structurally related bio-substances. The selectivity and sensitivity of this method were compared with a conventional fluorescence one using 2-bromoacetophenone that reacts with cytosine, adenine and their related substances. The present method was sufficiently selective toward cytosine, and approximately 50 times more sensitive than the conventional one. CONCLUSIONS: Our method permitted the quantitative determination of cytosine in human urines without any pretreatment for a primary screening test of inborn disorder in pyrimidine metabolism with immunodeficiency, and indicated the lower detection limit of 0.1 µmol/l cytosine which gave 3 times greater fluorescence intensity than that observed for the reagent blank.

A novel and specific fluorescence reaction for uracil.

Facile and specific methods to quantify a nucleobase in biological samples are of great importance for diagnosing disorders in nucleic acid metabolism. In the present study, a novel fluorogenic reaction specific for uracil has been developed. The reaction was carried out in an alkaline medium containing benzamidoxime and K(3)[Fe(CN)(6)] which were heated for 2.0 min. Under the optimum reaction conditions, strong fluorescence was produced only from uracil, not from other many biogenic compounds tested such as cytosine, thymine, adenine, guanine, nucleobases, nucleosides, nucleotides, amino acids, saccharides, creatine, creatinine and urea. The sensitivity of this method was compared with a known fluorogenic reaction using phenacylbromide which does not react with uracil but reacts with cytosine, adenine and their analogues. The proposed uracil-specific reaction showed approximately 400-fold higher sensitivity than the phenacylbromide reaction. The lower detection limit of uracil by the present method was 100 pmol mL(-1), and a good linearity of the calibration curve was obtained up to 100 nmol mL(-1) uracil. Due to its high sensitivity and specificity, the quantitative determination of uracil was possible by the proposed fluorimetric method.