Induction of sister chromatid exchanges (SCEs) in cultures of Chinese hamster ovary cells by 10 anticholinesterase organophosphate insecticides was investigated. The insecticides were two phosphates (dichlorvos and dicrotophos), four sulfur-containing organophosphates (malathion, parathion, leptophos, and diazinon), and four oxygen analogs of the latter (malaoxon, paraoxon, leptophosoxon, and diazoxon). All of the compounds except diazinon induced statistically significant increases in SCE frequencies at concentrations between 0.03 and 1.0 mM. These results suggest that SCE induction is a common property of organophosphate insecticides. Compared to the sulfur-containing organophosphates, the oxygen analogs consistently produced higher SCE frequencies and had stronger antiproliferative activity. Compared to two known genotoxicants, doxorubicin and ethyl methanesulfonate, the ability of organophosphates to produce SCEs is much weaker.

Animals↗

PubMedDate not supplied

Histochemical study of vascular endothelial growth factor in squamous cell carcinoma of the esophagus.

BACKGROUND/AIMS: Vascular endothelial growth factor (VEGF) plays a key role in tumor angiogenesis. The aim of this study was to clarify the significance of VEGF expression in esophageal squamous cell carcinoma (SCC). METHODOLOGY: Tissues samples were taken from 52 patients with esophageal SCC after surgery. VEGF expression in these SCCs was examined immunohistochemically. Microvessels in the tumor stained for Factor VIII-related antigen were counted. Ki-67 antigen as a proliferative marker was immunostained with MIB-1, and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate biotin nick end labeling was performed for the evaluation of apoptosis. Ki-67 labeling index (LI) and apoptotic index were then calculated. RESULTS: VEGF expression was observed in 30 of the patients (57.7%). The microvessel count was significantly higher (p = 0.007), and the apoptotic index was significantly lower (p < 0.0001) in the SCC with VEGF expression than in the SCC without it, but no significant difference was observed in the Ki-67 LI between these groups. There was an inverse correlation between the microvessel count and the apoptotic index (p = 0.007). In the clinicopathologic factors, histologic venous invasion of cancer cells (p = 0.039) and lymph node metastasis (p = 0.049) were significantly correlated with VEGF expression. The survival rate after curative surgery was better in the patients without VEGF expression (p < 0.05), and distant organ metastasis after surgery was frequently observed in the patients with VEGF expression (p = 0.023). CONCLUSIONS: These results suggest that VEGF expression is associated with angiogenesis in esophageal SCC, and may be a prognostic factor in patients with esophageal SCC. Furthermore, apoptosis may be influenced by angiogenesis in esophageal SCC.

Aged↗

PubMedDate not supplied

Effective treatment with chemotherapy and surgical resection for small cell carcinoma of the esophagus: report of a case.

We report on a patient with small cell carcinoma of the esophagus treated with effective combination chemotherapy followed by surgical resection. A 69 year-old male had an ulcerated tumor in the middle part of the esophagus, which was microscopically diagnosed as small cell carcinoma of the esophagus. After combination chemotherapy, endoscopy showed that the esophageal tumor had changed into a shallow ulcer. No cancer cell was found in the biopsy specimen of the ulcer. A subtotal esophagectomy with regional lymph node dissection was performed. Histological examination showed that a few cancer cells remained in a microvessel of the submucosal layer in the removed esophagus and no cancerous lesion was found in regional lymph nodes. The patient was well and was able to remain at home. However, he eventually died 21 months after first detection of the carcinoma due to progression of multiple lung and mediastinal lymph node metastases. After complete or partial remission is achieved by the combination chemotherapy, surgical resection may be recommended as the second therapy that occasionally produces long-term remission and possibly long-term survival for patients with small cell carcinoma of the esophagus, such as the present case.

Aged↗