While no relationship exists between the severity of heartburn and the development of Barretts esophagus, a relationship does exist between chronic heartburn and the development of Barretts esophagus. Sometimes, people with Barretts esophagus have no heartburn symptoms at all. Some anecdotal evidence indicates those with the eating disorder bulimia are more likely to develop Barretts esophagus because bulimia can cause severe acid reflux, and because purging also floods the esophagus with acid. However, a link between bulimia and Barretts esophagus remains unproven.During episodes of reflux, bile acids enter the esophagus, and this may be an important factor in carcinogenesis. Individuals with GERD and BE are exposed to high concentrations of deoxycholic acid that has cytotoxic effects and can cause DNA damage. Diagnosis
Both macroscopic (from endoscopy) and microscopic positive findings are required to make a diagnosis. Barretts esophagus is marked by the presence of columnar epithelia in the lower esophagus, replacing the normal squamous cell epithelium—an example of metaplasia. The secretory columnar epithelium may be more able to withstand the erosive action of the gastric secretions; however, this metaplasia confers an increased risk of adenocarcinoma. Screening
Screening endoscopy is recommended among males over the age of 60 who have reflux symptoms that are of long duration and not controllable with treatment. Among those not expected to live more than 5 years screening is not recommended.The Seattle protocol is used commonly in endoscopy to obtain endoscopic biopsies for screening, taken every 1 to 2 cm from the gastroesophageal junction.
This is a significant problem, as it can cause weight loss of 55 to 75 pounds per animal. Some species of lice infesting cattle include the cattle biting louse (Bovicola bovis), the shortnosed cattle louse (Haematopinus eurysternus), the longnosed cattle louse (Linognathus vituli), and the little blue cattle louse (Solenopotes capillatus). Treatment
Cattle infested with bovine pediculosis are generally treated chemically, by drugs like ivermectin and cypermethrin. History
In the 15th century, topical mercury treatment was used to treat pediculosis. See also
Nitpicking

References
External links

Head louse infestations: Biology, prevention and control  by Prof. Kosta Y. Mumcuoglu
Head lice: Biology and Management at IdentifyUS LLC
National Pediculosis Association
Frankowski BL, Weiner LB (September 2002). "Head lice". Pediatrics. 110 (3): 638–643. doi:10.1542/peds.110.3.638. PMID 12205271. S2CID 245074002. Archived from the original on 2008-10-13. Retrieved 2004-07-12. Morewitz H (2005). "A Brief History of Head Lice". Speare R (2007). "Head Lice Information Sheet". James Cook University, N. Queensland, Australia. Archived from the original on 2014-05-29. Pediculus humanus Head Lice Infestation: Symptoms, Causes & Diagnosis