Dr. Avideh Motmaen-Far, Osteopath D.O./Radio Koocheh
Stomach ulcer is a common disease that affects millions of adults and children each year around the globe. It is mainly caused by Helicobacter pylori that infects the stomachs of one-sixth of the world’s population. A stomach ulcer also called peptic ulcer is a small erosion in the stomach. An ulcer is not contagious but it can become cancerous. While duodenal ulcers are almost always benign, stomach ulcers may become malignant.
Stomach ulcer is defined as mucosal erosions equal to or greater than 0.5 cm of an area of the gastrointestinal tract. The majority of ulcers are known to be caused by Helicobacter Pylori, a bacterium that lives in the stomach but they can also be caused or worsened by drugs such as aspirin, ibuprofen and all the other Non-steroidal anti-inflammatory drugs. Helicobacter pylori may be transmitted from person to person through contaminated food and water. Antibiotics are the most effective treatment for Helicobacter pylori peptic ulcers.
We are not sure of the exact reason why children develop stomach ulcers but we know that unlike adults, children do not usually develop stomach ulcers because of Helicobacter pylori infections but as a result of medication. Stomach ulcer appears when the gastric mucosal lining of the stomach is destroyed by hydrochloric acid, an acid normally present in the digestive juices of the stomach. The chronic inflammation due to Helicobacter pylori colonizing the mucus of the stomach seems to be the most important factor in gastric and duodenal ulcers. The bacterium cause a chronic gastritis which influence the production of gastrin in the stomach. Gastrin is a hormone that stimulates secretion of gastric acid (HCl) by the parietal cells of the stomach. The increase in gastric acid production ends up with an erosion of the mucosa of the stomach and therefore an ulceration of the lining of the stomach.
What has once been a rare cancer, oesophageal adenocarcinoma now constitute approximately half of all oesophageal cancers cases in countries such as the United States and the United Kingdom.
Abdominal pain in the epigastria area is the most common sign of a peptic ulcers. This pain is related to mealtimes. It may last a few minutes or several hours and it may be worse when the stomach is empty. Gastric ulcers are usually exacerbated by food while the duodenal ulcers are usually relieved by food. Bloating, water brash, nausea, vomiting, loss of appetite, weight loss, hematemesis are other symptoms of stomach ulcer. The symptoms may vary with the location of the ulcer and the patient’s age. Usually, children and the elderly do not develop any symptoms unless complications have arisen.
Scientists have recently identified a group of substances that block a key chemical pathway that the Helicobacter pylori needs for survival. The scientists knew from past research that blocking flavodoxin, a key protein that Helicobacter pylori needs for survival, could be the key to developing narrow-spectrum antibiotics that specifically target Helicobacter pylori. Because an estimated one billion people remain infected worldwide because of the cost of existing antibiotics and the emergence of antibiotic resistant strains of the bacteria. These new inhibitors constitute promising candidates to develop new specific antibiotics against Helicobacter pylori. While some scientists are trying to find new antibiotics to fight the Helicobacter pylori, other scientists have found that people who had H. pylori strains carrying a gene called CagA have 50% less chance to get adenocarcinoma of the oesophagus.
Farin Kamangar, M.D., Ph.D., a research fellow at the National Cancer Institute and co author in this study said that CagA- positive strains of H. pylori may decrease the risk of adenocarcinoma by reducing acid production in the stomach and, therefore, reducing acid reflux to the oesophagus. She believes that it may also work by decreasing the production of the hormone ghrelin, which is secreted from the stomach to stimulate appetite. A reduction in the level of ghrelin may lead to lower rates of obesity, an important risk factor for adenocarcinoma.
It seems that with advancements in sanitation and antibiotics, H. pylori have become less common which have consequently lowered the incidence of stomach cancer and ulcers. However, as H. pylori, including CagA-positive H. pylori, has become less common, oesophageal adenocarcinomas have increased. The study suggests that the declining rates of H. pylori in developed populations may be partly responsible for this increase. What has been once a rare cancer, oesophageal adenocarcinomas now constitute approximately half of all oesophageal cancers cases in countries such as the United States and the United Kingdom.
According to Kamangar, humans had been living with H. pylori for 60,000 years and it has once been present in the stomach of about everyone. Despite of being the potential cause of stomach cancer and ulcers, H. pylori’s long history of co-existence with humans suggests that it also may have some beneficial effects, including possible roles in reducing diarrheal diseases and asthma. In this study, Kamangar and co-author Farhad Islami of the University of Tehran in Iran analyzed results from 19 published studies examining the associations of H. pylori with oesophageal adenocarcinoma and oesophageal squamous cell carcinoma, another type of oesophageal cancer.
«نوشته فوق می تواند نظر نویسنده باشد و الزامن نظر رادیو کوچه نیست»
