Timeline of peptic ulcer disease and Helicobacter pylori

This is a timeline of the events relating to the discovery that peptic ulcer disease is caused by H. pylori. In 2005, Barry Marshall

Barry Marshall

Barry James Marshall, AC, FRS, FAA is an Australian physician, Nobel Prize laureate in Physiology or Medicine, and Professor of Clinical Microbiology at the University of Western Australia. Marshall is well-known for proving that the bacterium Helicobacter pylori Barry James Marshall, AC, FRS, FAA...

and Robin Warren

Robin Warren

John Robin Warren AC is an Australian pathologist, Nobel Laureate and researcher who is credited with the 1979 re-discovery of the bacterium Helicobacter pylori, together with Barry Marshall.- Life and career :...

were awarded the Nobel Prize in Physiology or Medicine

Nobel Prize in Physiology or Medicine

The Nobel Prize in Physiology or Medicine administered by the Nobel Foundation, is awarded once a year for outstanding discoveries in the field of life science and medicine. It is one of five Nobel Prizes established in 1895 by Swedish chemist Alfred Nobel, the inventor of dynamite, in his will...

for their discovery that peptic ulcer disease (PUD) was primarily caused by Helicobacter pylori

Helicobacter pylori

Helicobacter pylori , previously named Campylobacter pyloridis, is a Gram-negative, microaerophilic bacterium found in the stomach. It was identified in 1982 by Barry Marshall and Robin Warren, who found that it was present in patients with chronic gastritis and gastric ulcers, conditions that were...

, a bacterium with affinity for acidic environments, such as the stomach

Stomach

The stomach is a muscular, hollow, dilated part of the alimentary canal which functions as an important organ of the digestive tract in some animals, including vertebrates, echinoderms, insects , and molluscs. It is involved in the second phase of digestion, following mastication .The stomach is...

. As a result, PUD that is associated with H. pylori is currently treated with antibiotic

Antibiotic

An antibacterial is a compound or substance that kills or slows down the growth of bacteria.The term is often used synonymously with the term antibiotic; today, however, with increased knowledge of the causative agents of various infectious diseases, antibiotic has come to denote a broader range of...

s used to eradicate the infection. For 30 years prior to their discovery, it was widely believed that PUD was caused by excess acid

Acid

An acid is a substance which reacts with a base. Commonly, acids can be identified as tasting sour, reacting with metals such as calcium, and bases like sodium carbonate. Aqueous acids have a pH of less than 7, where an acid of lower pH is typically stronger, and turn blue litmus paper red...

in the stomach

Stomach

. During this time, acid control was the primary method of treatment for PUD, to only partial success; among other effects, it is now known that acid suppression alters the stomach milieu to make it less amenable to H. pylori infection.

Background

Before the 1950s, there were many microbiological descriptions of bacteria in the stomach and in gastric acid secretions, lending credence to both the infective theory and the hyperacidity theory as being causes of peptic ulcer disease. A single study, conducted in 1954, did not find evidence of bacteria on biopsies of the stomach stained traditionally; this effectively established the acid theory as dogma

Dogma

Dogma is the established belief or doctrine held by a religion, or a particular group or organization. It is authoritative and not to be disputed, doubted, or diverged from, by the practitioners or believers...

. This paradigm was altered when Warren and Marshall effectively proved Koch's postulates

Koch's postulates

Koch's postulates are four criteria designed to establish a causal relationship between a causative microbe and a disease. The postulates were formulated by Robert Koch and Friedrich Loeffler in 1884 and refined and published by Koch in 1890...

for causation of PUD by H. pylori through a series of experiments in the 1980s; however, an extensive effort was required to convince the medical community of the relevance of their work. Now, all major gastrointestinal societies agree that H. pylori is the primary nondrug cause of PUD worldwide, and advocate its eradication as essential to treatment of gastric and duodenal ulcers. Additionally, H. pylori has been associated with lymphomas

Gastric lymphoma

Primary gastric lymphoma is an uncommon condition, accounting for less than 15% of gastric malignancies and about 2% of all lymphomas. However, the stomach is a very common extranodal site for lymphomas...

and adenocarcinomas of the stomach, and has been classified by the World Health Organization

World Health Organization

The World Health Organization is a specialized agency of the United Nations that acts as a coordinating authority on international public health. Established on 7 April 1948, with headquarters in Geneva, Switzerland, the agency inherited the mandate and resources of its predecessor, the Health...

as a carcinogen

Carcinogen

A carcinogen is any substance, radionuclide, or radiation that is an agent directly involved in causing cancer. This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes...

. Advances in molecular biology

Molecular biology

Molecular biology is the branch of biology that deals with the molecular basis of biological activity. This field overlaps with other areas of biology and chemistry, particularly genetics and biochemistry...

in the late 20th century led to the sequencing of the H. pylori genome, resulting in a better understanding of virulence factor

Virulence factor

Virulence factors are molecules expressed and secreted by pathogens that enable them to achieve the following:* colonization of a niche in the host...

s responsible for its colonization and infection, on the DNA level.

Pre-20th century

Pre 16th century

Hippocrates

Hippocrates of Cos or Hippokrates of Kos was an ancient Greek physician of the Age of Pericles , and is considered one of the most outstanding figures in the history of medicine...

first describes gastric symptoms.

Avicenna

Abū ʿAlī al-Ḥusayn ibn ʿAbd Allāh ibn Sīnā , commonly known as Ibn Sīnā or by his Latinized name Avicenna, was a Persian polymath, who wrote almost 450 treatises on a wide range of subjects, of which around 240 have survived...

notes the relationship between gastric pain and mealtimes.

1586

Marcellus Donatus of Mantua performs autopsies and describes gastric ulcers.

1688

Johannes von Murault observes duodenal ulcers.

1728

Stahl hypothesizes that some fever

Fever

Fever is a common medical sign characterized by an elevation of temperature above the normal range of due to an increase in the body temperature regulatory set-point. This increase in set-point triggers increased muscle tone and shivering.As a person's temperature increases, there is, in...

s are related to gastric inflammation and ulceration.

1761

Pain is associated with stomach ulcers.

1799

Matthew Baillie

Matthew Baillie was a Scottish physician and pathologist.-Life:...

publishes a description of ulcers.

1812

Broussais

François-Joseph-Victor Broussais

François-Joseph-Victor Broussais was a French physician.-Life:From his father, who was also a physician, he received his first instructions in medicine, and he studied for some years at a college in Dinan named after him, "Collège François Broussais"...

discovers that if acute gastritis

Gastritis

Gastritis is an inflammation of the lining of the stomach, and has many possible causes. The main acute causes are excessive alcohol consumption or prolonged use of nonsteroidal anti-inflammatory drugs such as aspirin or ibuprofen. Sometimes gastritis develops after major surgery, traumatic...

is untreated, it can become chronic.

1821

Nepveu argues for a relationship between gastritis and gastric cancer.

1822

William Beaumont

William Beaumont was a surgeon in the U.S. Army who became known as the "Father of Gastric Physiology" following his research on human digestion.-Early life:...

first demonstrates the acidity of the stomach and a relationship between acid levels and mood.

1868

Kussmaul

Adolph Kussmaul

Adolph Kussmaul was a German physician and a leading clinician of his time. He was born as the son and grandson of physicians at Graben near Karlsruhe and studied at Heidelberg. He entered the army after graduation and spent two years as an army surgeon...

suggests using bismuth

Bismuth

Bismuth is a chemical element with symbol Bi and atomic number 83. Bismuth, a trivalent poor metal, chemically resembles arsenic and antimony. Elemental bismuth may occur naturally uncombined, although its sulfide and oxide form important commercial ores. The free element is 86% as dense as lead...

compounds, an antibacterial agent, to treat peptic ulcers (bismuth subsalicylate

Bismuth subsalicylate

Bismuth subsalicylate, with a nominal chemical formula of C7H5BiO4, It is a colloidal substance obtained by hydrolysis of bismuth salicylate . The actual structure is unknown and the formulation is only approximate. Recent evidence indicates that it is composed of a bismuth oxide core structure...

has since been used in many commercial drugs, including Pepto Bismol as part of antibacterial H. pylori treatment). The antibacterial properties of bismuth were not known until much later.

1875

G. Bottcher and M. Letulle hypothesize that ulcers are caused by bacteria

Bacteria

Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...

1880

J. Cohnheim suggests that ulcers may be caused by chemical factors.

1881

Klebs

Edwin Klebs

Theodor Albrecht Edwin Klebs was a German-Swiss pathologist. He is mainly known for his work on infectious diseases. He is the father of Arnold Klebs.-Life:...

notes the presence of bacteria-like organisms in the lumen

Lumen (anatomy)

A lumen in biology is the inside space of a tubular structure, such as an artery or intestine...

of the gastric glands.

1889

Walery Jaworski

Walery Jaworski , was one of the pioneers of gastroenterology in Poland.In 1899 he described bacteria living in the human stomach that he named "Vibrio rugula". He speculated that they were responsible for stomach ulcers, gastric cancer and achylia. It was one of the first observations of...

describes spiral organisms in sediment washings of humans. He suggests these organisms might be involved with gastric disease.

1892

Giulio Bizzozero

Giulio Bizzozero was an Italian doctor and medical researcher. He is known as the original discoverer of Helicobacter pylori, the bacteria which is responsible for peptic ulcer disease...

observes spiral organisms in the stomach of dogs.

1896

Saloon finds spirochetes in the stomachs of cats and mice.

1900–1950

1905

F. Reigel suggests that ulcers are caused by excess acid.

1906

Krienitz finds bacteria in the stomach of people with gastric cancer.

Turck feeds dogs Bacillus coli and produces ulcers.

1907

Berkley Moynihan suggests that acid is a cause of ulcers.

1910

Schwartz publishes the excess acid theory of the ulcer, coining the famous phrase "no acid, no ulcer."

Gibelli claims to be unable to reproduce Turck's study where he artificially created ulcers by feeding dogs bacteria.

1913

Rosenow suggests that streptococci produce ulcers.

1915

Antacid

An antacid is a substance which neutralizes stomach acidity.-Mechanism of action:Antacids perform a neutralization reaction, increasing the pH to reduce acidity in the stomach. When gastric hydrochloric acid reaches the nerves in the gastrointestinal mucosa, they signal pain to the central nervous...

s are first recommended for the treatment of PUD.

Bacteria are associated with PUD, but it is assumed that the bacteria reside in the mouth.

1919

Kasai and Kobayashi isolate spirochetes in cats and transmit them to rabbits, producing ulcers.

1921

Luger discovers spirochetes in the gastric juice, and associates their presence with gastric cancer.

1924

Luck and Seth discover urease

Urease

Urease is an enzyme that catalyzes the hydrolysis of urea into carbon dioxide and ammonia. The reaction occurs as follows:In 1926, James Sumner showed that urease is a protein. Urease is found in bacteria, yeast, and several higher plants. The structure of urease was first solved by P.A...

in the human stomach, which they believe is naturally occurring. It is now known that one of the virulence factors of H. pylori is the urease enzyme, which splits urea

Urea

Urea or carbamide is an organic compound with the chemical formula CO2. The molecule has two —NH2 groups joined by a carbonyl functional group....

into ammonia

Ammonia

Ammonia is a compound of nitrogen and hydrogen with the formula . It is a colourless gas with a characteristic pungent odour. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to food and fertilizers. Ammonia, either directly or...

1925

Hoffman injects a small sample from a human with PUD into a guinea pig, producing ulcers, and isolates a bacterium which he believes caused the ulcers.

1936

First edition of the Russian Large Medical Encyclopedia suggests infection is one of the causes of PUD.

1939

A. Stone Freedberg begins a study to look for bacteria in the human stomach at Beth Israel Hospital

Beth Israel Hospital

Beth Israel Hospital may refer to:*Beth Israel Deaconess Medical Center in Boston*Beth Israel Medical Center in Manhattan*Beth Israel Medical Center in Newark...

. He finds H. pylori. It is rumored that others cannot reproduce the results, although no negative results are published.

James Doenges describes spirochetes in autopsies.

1940

Freedberg and Baron observe spirochetes in autopsies. Freedberg abandons his research, however, after his boss advises him to move to another subject. In 2005, Marshall speculates that Freedberg would have won the Nobel Prize in 1951 had he continued his work.

1948

Fitzgerald and Murphy hypothesize that PUD is caused by acid eating away mucosa, and demonstrate the effectiveness of urea

Urea

Urea or carbamide is an organic compound with the chemical formula CO2. The molecule has two —NH2 groups joined by a carbonyl functional group....

as a treatment for PUD.

1950–1970

1951

J. Allende publishes a book describing the treatment of gastric ulcers with penicillin

Penicillin

Penicillin is a group of antibiotics derived from Penicillium fungi. They include penicillin G, procaine penicillin, benzathine penicillin, and penicillin V....

1953

Dintzis and Hastings are able to stop urease

Urease

production in mice with antibiotic

Antibiotic

s, suggesting a relationship between urease and a bacterial infection.

1954

Palmer publishes a study which finds no bacteria in the human stomach. He concludes earlier discoveries were a result of contamination. Unfortunately, he chooses not to use a silver stain

Stain

A stain is a discoloration that can be clearly distinguished from the surface, material, or medium it is found upon. Stains are caused by the chemical or physical interaction of two dissimilar materials...

ing method, which will be later used to reveal H. pylori by Warren and Marshall.

1955

Tarnopolskaya observes that penicillin seems to cure some peptic ulcers.

Moutier and Cornet suggest treating gastritis with antibiotics.

Kornberg and Davies observe that antibiotics reduce urease in cats.

1957

Charles Lieber and Andre Lefèvre discover that antibiotics reduce gastric urea to ammonia

Ammonia

conversion.

1958

Gordon observes that penicillin cures some peptic ulcers.

John Lykoudis

John Lykoudis was a general practitioner in Greece who treated patients suffering from peptic ulcer disease with antibiotics long before it was commonly recognized that bacteria were a dominant cause for the disease....

successfully treats his own gastroenteritis

Gastroenteritis

Gastroenteritis is marked by severe inflammation of the gastrointestinal tract involving both the stomach and small intestine resulting in acute diarrhea and vomiting. It can be transferred by contact with contaminated food and water...

with antibiotics.

Lieber and Lefèvre present their results at the World Congress of Gastroenterology in Washington. It is not well received because of the widespread belief that bacteria cannot survive in the human stomach, due to Palmer.

1959

Lieber and Lefèvre publish a follow-up study demonstrating that antibiotics prevent the conversion of urea to ammonia in the human stomach.

Conway et al. call into question the extent of urease produced by bacteria in mice, as an argument against the bacterial theory of PUD.

1960

Vital and Orrego observe Campylobacter

Campylobacter

Campylobacter is a genus of bacteria that are Gram-negative, spiral, and microaerophilic. Motile, with either unipolar or bipolar flagella, the organisms have a characteristic spiral/corkscrew appearance and are oxidase-positive. Campylobacter jejuni is now recognized as one of the main causes...

-like organisms in the stomachs of cats and dogs.

Lykoudis is awarded a Greek patent (#22,453) for his antibiotic treatment of PUD.

1962

Susser and Stein publish a paper identifying a cohort phenomenon

Cohort effect

The term cohort effect is used in social science to describe variations in the characteristics of an area of study over time among individuals who are defined by some shared temporal experience or common life experience, such as year of birth, or year of exposure to radiation.Cohort effects are...

of PUD in England. This is taken as evidence for stress causing PUD.

1964

Lykoudis presents his antibiotic treatment for PUD at a meeting of the Medico-Surgical Society in Greece. He is largely shunned by the medical establishment.

1966

Lykoudis' manuscript is rejected by the Journal of the American Medical Association

Journal of the American Medical Association

The Journal of the American Medical Association is a weekly, peer-reviewed, medical journal, published by the American Medical Association. Beginning in July 2011, the editor in chief will be Howard C. Bauchner, vice chairman of pediatrics at Boston University’s School of Medicine, replacing ...

1967

Susumu Ito describes Campylobacter-like organisms attached to a gastric epithelial cell.

1968

Lykoudis is fined 4,000 drachmas for treating PUD patients with his treatment, which includes antibiotics.

1970–21st century

1971

Howard Steer observes H. pylori from biopsies of a patient with ulcers.

1972

The first report of successfully using furazolidone

Furazolidone

Furazolidone is a nitrofuran antibacterial. It is marketed by Roberts Laboratories under the brand name Furoxone and by GlaxoSmithKline as Dependal-M.-Uses:It is used to treat diarrhoea and enteritis caused by bacteria or protozoan infections....

(an antibacterial agent) to treat PUD in China.

1974

Morozov observes H. pylori; he does not connect this discovery to PUD.

A well regarded study of PUD is published which does not mention bacteria.

1975

Steer and Colin-Jones publish their results regarding H. pylori and its relation to PUD. They decide that it was Pseudomonas

Pseudomonas

Pseudomonas is a genus of gammaproteobacteria, belonging to the family Pseudomonadaceae containing 191 validly described species.Recently, 16S rRNA sequence analysis has redefined the taxonomy of many bacterial species. As a result, the genus Pseudomonas includes strains formerly classified in the...

, a contaminant, and not related to PUD.

1978

At a meeting of the American Gastroenterology Association in Las Vegas, several papers are presented which suggest that acid control via H₂ blockers is ineffective at curing PUD.

1979

Ramsey publishes a study demonstrating that bismuth can help eradicate PUD. Bismuth is an antibacterial agent, although this is not recognized by Ramsey.

J. Robin Warren first observes H. pylori in a gastric biopsy.

Fung, Papadimitriou, and Matz observe H. pylori.

1981

Yao Shi observes bacteria in the stomach, but he believes they are passing through the stomach and not colonizing it.

July: Barry Marshall joins gastroenterology division of Royal Perth Hospital

Royal Perth Hospital

Royal Perth Hospital is an 855-bed teaching hospital located on the northeastern edge of the CBD of Perth, Western Australia . Royal Perth Hospital also has specialised rehabilitation facilities at Shenton Park.-History:...

and meets Robin Warren

October: Marshall and Warren successfully treat their first PUD patient with antibiotics.

1982

Satoha et al. find evidence for an infectious cause of ulcers in rats.

Marshall and Warren begin their first study to determine the relationship between H. pylori and PUD.

First successful culturing of H. pylori performed; it occurs almost by accident.

October: Marshall discovers the bacteria he is investigating are not campylobacteria, by looking at electron micrographs.

October 2: Marshall presents his and Warren's results at a local College of Physicians meeting. He meets with criticism, which Marshall later admits was well-founded (at least in part).

1983

January: Two letters authored by Warren and Marshall, respectively, are sent to The Lancet describing their results.

February: Gastroenterological Society of Australia rejects Marshall's abstract to present his research at their yearly conference. They deem it in the bottom 10% of papers submitted. The same abstract is accepted for presentation at a Campylobacter workshop in Brussels.

April: Marshall and Ian Hislop begin a study to compare bismuth treatment with cimetidine

Cimetidine

Cimetidine INN is a histamine H2-receptor antagonist that inhibits the production of acid in the stomach. It is largely used in the treatment of heartburn and peptic ulcers. It is marketed by GlaxoSmithKline under the trade name Tagamet...

. The study is abandoned because it is inconclusive.

June: Warren and Marshall's letter appears in The Lancet.

September: H. pylori is observed in patients outside of Australia.

After the appearance of the letters in The Lancet, groups around the world begin isolating H. pylori.

1984

A paper describing Marshall and Warren's results is accepted by the Gastroenterological Society of Australia for presentation.

Marshall and Goodwin attempt to infect pigs with H. pylori in an attempt to demonstrate that it causes PUD. The experiment fails.

Marshall and Warren's paper is accepted by The Lancet in May and published in June. Many reviewers dislike the paper.

McNulty and Watson are able to reproduce Marshall and Warren's results.

June 12: Marshall intentionally consumes H. pylori and becomes ill. He takes antibiotics and is relieved of his symptoms.

The National Health and Medical Research Council

National Health and Medical Research Council

The National Health and Medical Research Council is Australia's peak funding body for medical research, with a budget of roughly 700 million dollars a year...

of Australia fully funds Marshall's research into H. pylori.

A study is published in China about the effectiveness of treating PUD with an antibacterial agent.

July 31: The New York Times

The New York Times

The New York Times is an American daily newspaper founded and continuously published in New York City since 1851. The New York Times has won 106 Pulitzer Prizes, the most of any news organization...

publishes an article by its medical correspondent Dr. Lawrence K. Altman on the possible link between H. pylori and PUD. He states in 2002, "I’ve never seen the medical community more defensive or more critical of a story" since he joined the newspaper in 1969.

1985

Marshall publishes the results of self-induced infection.

1987

Morris intentionally consumes H. pylori. Like Marshall, he becomes ill, but unlike Marshall, he is not completely cured by antibiotics. The infection will remain with him for three years.

An extensive study in Dublin demonstrates that eradicating H. pylori substantially reduces recurrence of ulcers.

1990

Rauws and Tytgat describe cure of duodenal ulcer by eradication of H. pylori using a triple-therapy regimen, consisting of bismuth and two antibiotics. Triple-therapy, modernized to a proton pump inhibitor

Proton pump inhibitor

Proton-pump inhibitors are a group of drugs whose main action is a pronounced and long-lasting reduction of gastric acid production. They are the most potent inhibitors of acid secretion available today. The group followed and has largely superseded another group of pharmaceuticals with similar...

and two antibiotics, soon becomes first line therapy for eradication.

World Congress of Gastroenterology recommends eradicating H. pylori to cure duodenal ulcers.

First report of resistance of H. pylori to the antibiotic metronidazole

Metronidazole

Metronidazole is a nitroimidazole antibiotic medication used particularly for anaerobic bacteria and protozoa. Metronidazole is an antibiotic, amebicide, and antiprotozoal....

. Resistance of H. pylori to treatment will lead to the development of many different antibiotic and proton pump inhibitor regimens for eradication.

1992

Fukuda et al. prove ingestion of H. pylori causes gastritis in rhesus monkeys.

Covacci et al. sequence the CagA gene, which encodes for a cytotoxin-associated surface protein, which correlated strongly with strains of H. pylori that caused duodenal ulcers. This was the first description of a virulence factor

Virulence factor

Virulence factors are molecules expressed and secreted by pathogens that enable them to achieve the following:* colonization of a niche in the host...

for H. pylori infection determined by molecular

Molecular biology

techniques.

1994

Fujioka et al. prove similar results as those from Fukuda et al.

Patent

A patent is a form of intellectual property. It consists of a set of exclusive rights granted by a sovereign state to an inventor or their assignee for a limited period of time in exchange for the public disclosure of an invention....

s for acid reducing drugs expire, removing financial incentive to resist antibiotics as treatment of PUD.

A conference held by National Institute of Health (USA) demonstrates the general acceptance of H. pylori as cause of PUD in the US.

The World Health Organization

World Health Organization

's International Agency for Research on Cancer declares H. pylori a Group 1 carcinogen

Carcinogen

Parsonnet et al. describe an association between H. pylori and lymphoma

Lymphoma

Lymphoma is a cancer in the lymphatic cells of the immune system. Typically, lymphomas present as a solid tumor of lymphoid cells. Treatment might involve chemotherapy and in some cases radiotherapy and/or bone marrow transplantation, and can be curable depending on the histology, type, and stage...

s of the gastrointestinal tract. These malignant

MALT lymphoma

MALT lymphoma is a form of lymphoma involving the mucosa-associated lymphoid tissue , frequently of the stomach, but virtually any mucosal site can be afflicted...

ulcers can also be treated by eradicating Helicobacter.

1997

Tomb et al. complete sequencing of the entire 1,667,867 base pair

Base pair

In molecular biology and genetics, the linking between two nitrogenous bases on opposite complementary DNA or certain types of RNA strands that are connected via hydrogen bonds is called a base pair...

s of the H. pylori genome. This assists in identifying new virulence factor

Virulence factor

Virulence factors are molecules expressed and secreted by pathogens that enable them to achieve the following:* colonization of a niche in the host...

s for the infectivity of H. pylori on the molecular level.

2001

Chan et al. show in a randomized control trial that eradication of H. pylori even prevents bleeding from ulcers that is caused by aspirin

Aspirin

Aspirin , also known as acetylsalicylic acid , is a salicylate drug, often used as an analgesic to relieve minor aches and pains, as an antipyretic to reduce fever, and as an anti-inflammatory medication. It was discovered by Arthur Eichengrun, a chemist with the German company Bayer...

and non-steroidal anti-inflammatory drugs.

2002

The European Helicobacter Pylori Study Group published the Maastricht 2-2000 Consensus Report, suggesting a "test-and-treat" strategy for H. pylori in young patients without atypical symptoms. This strategy advocates the use of noninvasive testing to evaluate for H. pylori and simply treating if found, even in the absence of ulcer disease documented on endoscopy

Endoscopy

Endoscopy means looking inside and typically refers to looking inside the body for medical reasons using an endoscope , an instrument used to examine the interior of a hollow organ or cavity of the body. Unlike most other medical imaging devices, endoscopes are inserted directly into the organ...

2005

Warren and Marshall are awarded the Nobel Prize in Physiology or Medicine

Nobel Prize in Physiology or Medicine

for their work on H. pylori and PUD.

External links

Barry J. Marshall (2001). "One hundred years of discovery and rediscovery of Helicobacter pylori and its association with peptic ulcer disease". Chapter 3 of Helicobacter pylori: Physiology and Genetics ed. by Harry L. T. Mobley, George L. Mendz, and Stuart L. Hazell. ASM Press. ISBN 1-55581-213-9.

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