The Interplay among Radiation Therapy, Antibiotics and the Microbiota: Impact on Cancer Treatment Outcomes

Radiation therapy has been used for more than a century, either alone or in combination with other therapeutic modalities, to treat most types of cancer. On average, radiation therapy is included in the treatment plans for over 50% of all cancer patients, and it is estimated to contribute to about 40% of curative protocols, a success rate that may reach 90%, or higher, for certain tumor types, particularly on patients diagnosed at early disease stages. A growing body of research provides solid support for the existence of bidirectional interaction between radiation exposure and the human microbiota. Radiation treatment causes quantitative and qualitative changes in the gut microbiota composition, often leading to an increased abundance of potentially hazardous or pathogenic microbes and a concomitant decrease in commensal bacteria. In turn, the resulting dysbiotic microbiota becomes an important contributor to worsen the adverse events caused in patients by the inflammatory process triggered by the radiation treatment and a significant determinant of the radiation therapy anti-tumor effectiveness. Antibiotics, which are frequently included as prophylactic agents in cancer treatment protocols to prevent patient infections, may affect the radiation/microbiota interaction through mechanisms involving both their antimicrobial activity, as a mediator of microbiota imbalances, and their dual capacity to act as pro- or anti-tumorigenic effectors and, consequently, as critical determinants of radiation therapy outcomes. In this scenario, it becomes important to introduce the use of probiotics and/or other agents that may stabilize the healthy microbiota before patients are exposed to radiation. Ultimately, newly developed methodologies may facilitate performing personalized microbiota screenings on patients before radiation therapy as an accurate way to identify which antibiotics may be used, if needed, and to inform the overall treatment planning. This review examines currently available data on these issues from the perspective of improving radiation therapy outcomes

Drastic population decline and conservation prospects of roadside dark-bellied bonnet macaques (Macaca radiata radiata) of Southern India

We carried out a survey on roadside dark-bellied bonnet macaques (Macaca radiata radiata) on the highways around the south Indian city of Mysore. The present survey was the fourth since 1989 on the same populations. We divided the habitats into intensive cultivation (IC), wet cultivation (WC), and scrub forests (SC). The number of groups has significantly reduced from 54 to 31 and the number of animals has declined from 1,207 to 697 from 1989 to 2009. This decline has been recorded only in the IC and WC areas, whereas the population in SC with places of Hindu worship has remained stable. Due to the loss of roadside Ficus trees over the years, the habitat of the monkeys has almost disappeared. Since bonnet macaque is not primarily a forest-dwelling species, the seemingly widespread primate may soon become 'threatened' if the non-forest populations continue to decline. Scrub forests in small hillocks housing Hindu temples remain the only prospective places for conservation of bonnet macaques

Update on the management of gastrointestinal varices

Cirrhosis of liver is a major problem in the western world. Portal hypertension is a complication of cirrhosis and can lead to a myriad of pathology of which include the development of porto-systemic collaterals. Gastrointestinal varices are dilated submucosal veins, which often develop at sites near the formation of gastroesophageal collateral circulation. The incidence of varices is on the rise due to alcohol and obesity. The most significant complication of portal hypertension is life-threatening bleeding from gastrointestinal varices, which is associated with substantial morbidity and mortality. In addition, this can cause a significant burden on the health care facility. Gastrointestinal varices can happen in esophagus, stomach or ectopic varices. There has been considerable progress made in the understanding of the natural history, pathophysiology and etiology of portal hypertension. Despite the development of endoscopic and medical treatments, early mortality due to variceal bleeding remains high due to significant illness of the patient. Recurrent variceal bleed is common and in some cases, there is refractory variceal bleed. This article aims to provide a comprehensive review of the management of gastrointestinal varices with an emphasis on endoscopic interventions, strategies to handle refractory variceal bleed and newer endoscopic treatment modalities. Early treatment and improved endoscopic techniques can help in improving morbidity and mortality