Search

Anastomotic fistula represents one of the frequent causes of postoperative morbidity and mortality following transhiatal esophageal resections. The main etiological factor is the ischemia of the gastric tube created for digestive transit reconstruction. Evidence suggests that per operative hypoperfusion can be maintained or even impaired after the surgery. Several methods have been employed in an attempt to assess the blood perfusion of the gastric flap, but they all pose limitations. However, there is a chronological relationship between perfusion assessments, which are almost exclusively performed per operatively, and the occurrence of a leak, which commonly appears several days after the surgery. The authors have developed a method of gastric perfusion evaluation by single photon emission computed tomography scintigraphy, which corrects that temporal matter, allowing the estimation of postoperative gastric perfusion. It is noninvasive, low cost, and may be applied by the time frame when most fistulas occur. High correlation between the event fistula and the low radiotracer uptake in the group of studied patients could be demonstrated. A role in the research of perfusion evaluation of different types of esophageal reconstruction is suggested. [ABSTRACT FROM AUTHOR]

A comprehensive evaluation of the genotoxic potential of chemicals requires the assessment of the ability to induce gene mutations and structural chromosome (clastogenic activity) and numerical chromosome (aneugenic activity) aberrations. Aneuploidy is a major cause of human reproductive failure and an important contributor to cancer and it is therefore important that any increase in its frequency due to chemical exposures should be recognized and controlled. The in vitro binucleate cell micronucleus assay provides a powerful tool to determine the ability of a chemical to induce chromosome damage. The application of an anti-kinetochore antibody to micronuclei allows their classification into kinetochore-positive and kinetochore-negative, indicating their origin by aneugenic or clastogenic mechanisms, respectively. The availability of chromosome-specific centromere probes allows the analysis of the segregation of chromosomes into the daughter nuclei of binucleate cells to evaluate chromosome non-disjunction. Quantitative relationships between the two major causes of aneuploidy, chromosome loss and non-disjunction, can be determined. The mechanisms leading to chromosome loss and non-disjunction can be investigated by the analysis of morphological and structural changes in the cell division apparatus by the application of specific stains and antibodies for various cell division components. We illustrate such analyses by the demonstration of the interaction of the monomer bisphenol-A with the centrosome of the mitotic spindle and the folic acid antagonist pyrimethamine with the centromeres of chromosomes. Both types of modifications lead to the induction of aneuploidy in exposed cells. Our studies also implicate the products of the p53 and XPD genes in the regulation of the fidelity of chromosome segregation at mitosis. [ABSTRACT FROM PUBLISHER]