Ischemic colitis: surging waves of update.

Ischemic colitis is the most common type of intestinal ischemia, and it represents the consequences of acute or, more commonly, chronic blockage of blood flow through arteries that supply the large intestine. Ischemic colitis is manifested through a continuum of injury and considered as an illness of the elderly. The incidence of ischemic colitis has been underestimated, because many mild cases may go unreported. Patients experience abdominal pain, usually, localized to the left side of the abdomen, along with tenderness and bloody diarrhea. Severe ischemia may lead to bowel necrosis and perforation, which results in an acute abdomen and shock, frequently, being accompanied by lactic acidosis. Although computed tomography may have indicative findings, colonoscopy is the golden standard of diagnosis. Supportive care with intravenous fluids, optimization of hemodynamic status, avoidance of vasoconstrictive drugs, bowel rest, and empiric antibiotics will produce clinical improvement within 1 to 2 days in most patients. The condition resolves completely with conservative treatment, in most cases, but late diagnosis or severe ischemia can be associated with high rates of complications and death. However, when the interruption to the blood supply is more severe or more prolonged, the affected portion of the large intestine may have to be surgically removed. The present paper aims at bringing ischemic colitis up to date, by reviewing the current medical literature and extracting the contemporary data, about its presentation, diagnosis and treatment, which is of benefit to the readership, who may encounter this potentially fatal entity.

Mesenteric ischemia: still a deadly puzzle for the medical community.

The main goal of this article is to update etiology, epidemiology, diagnosis, treatment and outcome of the various causes of mesenteric ischemia in order to elucidate its labyrinthine clinical riddle, by reviewing the current English medical literature. Mesenteric ischemia is a quite uncommon disorder, observed in the emergency department. It is a life-threatening vascular emergency that requires early diagnosis and intervention to restore mesenteric blood flow and to prevent bowel necrosis and patient death. Consequently, it is a vital diagnosis to make because of its high mortality rate and its thorny complications. The underlying causes vary, and the prognosis depends on the specific findings during clinical examination. Vague and nonspecific clinical findings and limitations of diagnostic studies make the diagnosis a significant challenge. The prognosis of acute mesenteric ischemia of any type is grave. The complications following this medical jigsaw puzzle are also severe. Patients in whom the diagnosis is missed until infarction occurs have a mortality rate of 90%. Even with good treatment, up to 50-80% of patients die. Survivors of extensive bowel resection face lifelong disability. Despite the progress in understanding the pathogenesis of mesenteric ischemia and the development of treatment modalities, the entity remains a diagnostic challenge for clinicians. Delay in diagnosis contributes to a high mortality rate. Early diagnosis and adequate treatment can improve the clinical outcome. Even if diagnostic modalities have improved since the first successful attempts to confront effectively this clinical entity, mesenteric ischemia still remains a lethal diagnostic enigma for the medical community.

Genetic association studies in digestive system malignancies.

The multifactorial process of carcinogenesis in the digestive system involves mutations in oncogenes or tumor suppressor genes, as well as influence of environmental etiological factors. In recent years, common DNA polymorphisms in low penetrance genes emerged as genetic factors that seem to modulate an individual's susceptibility to malignancy, through interaction with environmental factors, such as diet or smoking. The increasing number of publications of genetic association studies on digestive system neoplasias has produced both important true association results and negative or controversial results. Here, we review the findings of genetic association studies of gene polymorphisms in regard to cancers of the digestive tract (oral, esophageal, nasopharyngeal, gastric and colorectal). We discuss the association of several DNA polymorphisms in genes of cytokines, matrix metalloproteinases, signal transduction proteins, diet-, and coagulation-related factors with specific types of cancer in the digestive tract. Genetic studies, which lead to a true association, are expected to increase understanding of the pathogenesis of each malignancy and to be a powerful tool of prevention and prognosis in the future.

Review. Animal models of carcinogenesis in the digestive system.

Digestive system malignancies are quite common, accounting for 25% of deaths from cancer in the European Union. Various etiological factors of carcinogenesis include hereditary mutations and susceptibility polymorphisms, inflammation due to infectious agents, environmental and dietary factors. Transgenic, knockout or mutant animal models are very useful in reproducing cancers of the digestive tract that occur in humans. They offer the opportunity to study the disease phenotype and the function of the underlying mechanisms of carcinogenesis. In addition, animal models are valuable tools in cancer treatment attempts with the combined use of gene targeting or chemotherapy. This review illustrates the importance of the numerous animal models that have been developed by various methods in order to study carcinogenesis in the digestive tract and test potential therapeutic treatments.