“I give permission for the team of BIO 150 instructors to use an essay that I may write as part ofthis assignment for an example for future students or for presentation purposes.”
CHRONIC GASTRITIS TYPE B
I.
Introduction:
Genetic studies support that Helicobacter pylori has coexisted with humans for “at least
58, 000 years” (qtd. in Murphy).
Chronic gastritis (gastric inflammation) and stomach diseases were a point of interest since
th
the 19 century, but it was not until the practice of endoscopies that great progress was
made. “During the 1970s and the early 1980s, scientists, physicians and researchers all
thought that the main cause of Peptic Ulcer Disease or PUD and Gastritis are stress and
lifestyle problems”. Alcohol abuse was also linked to these diseases, but the recurrence of
patients that did not consume alcohol called the attention of scientist to look for a different
cause. In 1979, the Australian pathologist Robert Warren noticed the presence of a specific
bacterium in half of the stomach-antrum biopsies he examined. Two years later, the physician
Barry Marshall joined him to pursue the study of said bacteria (Castillo). The Clinical
Microbiology Reviews of the American Society for Microbiology states that Helicobacter pylori
was identified by Warren and Marshall when making cultures from gastric biopsies. A Nobel
Prize was granted to them when later, in 2005, they connected the bacteria to peptic ulcer
disease, and linked to stomach cancer (Wroblewski et al.). The University of Connecticut
Health Center site states that there are two types of chronic gastritis. “Type A is associated
with antibodies to gastric parietal cells and CD4 cell mediated immunity to parietal cells”,
while type B is linked to the infection of the Helicobacter pylori bacterium (Cotran).
My mother was diagnosed with gastritis and prescribed omeprazole because of the
symptoms she reported to her doctor. Due to a worsening of the symptoms and because of a
family history of cancer, the doctor ordered a gastric endoscopy with a biopsy. The collected
tissue tested positive for Helicobacter pylori, and had a colony count of three crosses, which
made the doctor give a final diagnose of chronic gastritis. She was then put on a treatment
with amoxicillin, omeprazole, and clarithromycin; which successfully lowered the colony count
of the bacteria. Although the presence of the bacteria has decreased, to this day, stress
makes moderate symptoms reappear.
II.
Symptoms and Signs:
Over a three month period of time prior to being diagnosed, my mother noticed that
whichever the size of food intake; she immediately felt full. There was also a burning
sensation in the upper side of her stomach whenever she ate. Among other symptoms, she
experienced dramatic weight loss, sporadic acute pain going form the upper part of the
stomach towards her back; diarrhea, and fatigue.
The Salem Health Reference recognizes that it is common for Helicobacter pylori not to
cause infections. However, when present, they might include upper abdominal pain (called
dyspepsia), nausea, frequent burping, bloating, and weight loss, vomit and bloody stools
(Olle and Stanfill).
III.
Causative Agent:
Type B chronic gastritis has as causative agent the bacteria Helicobacter pylori. The
American Society for Microbiology indicates that the H. pylori bacteria are a Gram-negative
pathogen. It is rod shaped and has 3 to 5 polar flagella. It is selective, colonizing only the
gastric epithelium.
Hosts are unable to eliminate the infection, so the bacterium can live for many years even
in the extreme conditions of the stomach. In fact, it is unique in that is able to thrive in the
highly acidic stomach. H. pylori is able to do so because of enzymes like catalase, urease,
and oxidase that metabolize compound like urea into harmless ammonia that neutralizes the
environment enveloping the H. pylori (Wroblewskil et al.).
IV.
Pathogenicity and Pathogenesis
H. pylori makes use of the many flagella it has to attach to the stomach mucosa. The
acidic environment of the stomach is not suitable for the bacterium, so it synthesizes urease
to increase the pH by reducing the urea to ammonia and bicarbonate. These secretions
induce the formation of inflammatory cytokines. The inflammatory cytokines produced by the
cells and the proteases and phospholipases produced by the bacteria are damaging to the
mucous layer and make the lining in the stomach susceptible to the stomach acids (Salem
Press- Olle).
V.
Anatomy & Physiology
In Microbiology: An Introduction, it is stated that the normal mucosa of the stomach, has
cells that secrete gastric juice. This gastric juice contains proteolytic enzymes as well as
hydrochloric acid to activate these enzymes. There are other types of cells that are
specialized in producing a layer of mucus which function is to prevent the stomach from
digesting itself. H. pylori disrupts this defense, causing gastritis (Tortora et al. 719).
The infection has been directly related to contribution to the development of stomach
cancer. “ H. pylori is designated as a carcinogenic bacterium. Gastric cancer develops in 3%
of the people infected with these bacteria, but no infected persons develop gastric cancer”
(Tortora et al.719).
VI.
Diagnosis
According to Salem Health Helicobacter pylori can be diagnosed by an endoscopy,
where a flexible tube is pushed to the stomach to get a sample tissue. This tissue is later
tested for H. pylori presence. Breath tests are also used, where radioactively labeled urea is
ingested, and since the Helicobacter pylori breaks downs the urea to form radioactive carbon
dioxide, the presence of carbon dioxide is tested. Blood tests are also done to detect
antibodies against the bacteria. This last one however, will detect even prior infections (Olle).
VII.
Treatment
The usual treatment consists of three different drugs taken during 7-14 days. Two of the
three are antibiotics. These are usually clarithromycin and amoxicillin. The other one is
omeprazole (Prilosec) which is a proton pump inhibitor (PPI) (Olle). Also a light diet rich in
vegetables is recommended.
VIII.
Epidemiology
Infections caused by H. pylori are associated to the ingestion of elements like food and
liquids contaminated with the bacteria. Unsanitary conditions like contact with a stool used by
an infected person, their vomit or saliva. “The prevalence of H. pylori infection worldwide is
more than 50 percent of the population and is much higher in developing countries”
Sanitation is the most recommended preventive measure (Olle). Chronic gastritis is not a
reportable infectious disease in the United States.
References
Castillo, Joan Joseph. “Discovery of Helicobacter Pylori.” Experiment-Resources. 2010. 28 July
2012. .
Cotran RS, Kumar V, Robbins SL: Robbins Pathologic Basis of Disease. 5th ed. Philadelphia,
W.B. Saunders, 1994, pp. 770-772. 29 July 2012 <
http://radiology.uchc.edu/eAtlas/GI/1280.htm>
Murphy, Kate. “In Some Cases, even Bad Bacteria May Be Good.” Health. 31 Oct. 2011. The
New York Times. 27 July 2012
Olle, David A. M.S. “Helicobacter pylori infection.” Infectious Diseases & Conditions. Ed. H.
Bradford Hawley. Ipswich, MA: Salem Press, 2011. Salem Health Web. 30 July
2012.
Tortora, Gerard J., Funke, Berdell R., and Case, Christine L. Microbiology: An Introduction. San
Francisco: Pearson, 2010
Wroblewski, Lydia E., Peek Jr., Richard M., and Wilson, Keith T. “Helicobacter pylori and Gastric
Cancer: Factors That Modulate Disease Risk.” Clinical Microbiology Reviews 23.4: 713739. Oct. 2010. American Society for Microbiology. 30 July
2012
Online BIO 150
BIO 150 Microbial Disease Paper Directions
Paper Introduction – Module 5 and Module 6
The purpose of this assignment is to make connections from the textbook to the advancement
of science. In Module 5 and Module 6 we learn human diseases caused by microorganisms. In
this forum we will discuss the recent findings published in the literature that are related to the
topics in Modules 5 and 6.
Two assignments, thus two grades, are associated with this forum:
•
•
Write and host the discussion of your own paper. [30 points]
Participate in the discussions of at least three other papers submitted by peers. [10
points]
NOTE: You should submit your paper to Turnitin and post your paper in Forum 4 in Module 5 as
early as possible and no later than the due date. The Forum 4 discussion occurs during
Modules 5 and 6; the discussion continues until the end date. (The specific paper due date and
discussion end date may be found in Announcements.) You are responsible for hosting the
discussion of your paper during Modules 5 and 6.
Content
You will write a coherent report on a microbial disease that you once experienced or witnessed
(800-1200 words) that is pertinent to the content covered in Modules 5 and 6. In your essay,
you want to include relevant reports of new findings from the list of selected resources below.
Try to relate your paper to life experiences whenever applicable; be sure to refer to the
textbook.
Sometimes your posts for this assignment are so impressive that your instructor would like to
use them as an example for other students or for presentations to other instructors. We need
your permission to do that: Would you please include a statement in your post that gives us
that permission. It can be: “I give permission for the team of BIO 150 instructors to use a post
that I may write as part of this assignment for an example for future students or for
presentation purposes”. You may copy and paste this statement into your post. Your name and
any information that identifies you or anyone else in your writing will be removed. If you do not
include this statement we won’t use your work.
Guidelines
•
Introduction– a brief recount of your personal (or professional) experience and a brief
introduction of the disease (you may include the history and discovery of the disease)
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Online BIO 150
•
•
Symptoms and signs– describe the symptoms and signs experienced and compare these
to the ones stated in the textbook or in a medical field
Causative agent– identify the name and characteristics of the pathogen (including
structural, morphological, genetic, and metabolic characteristics, etc.)
Note: This assignment is to report on a microbial disease; the disease has to have an
identified pathogen.
•
•
•
•
•
•
Pathogenicity and Pathogenesis– describe how the pathogen causes disease, how the
pathogen evades the host defense, and the virulence factors; also describe the
development and progress of the disease.
Anatomy, Physiology, and Pathophysiology– an introduction of the normal and
pathological Anatomy & Physiology that are implicated.
Diagnosis– the steps and tests performed to identify and confirm the cause of this
disease
Treatment– include how the disease is treated and why the treatment works (for
instance, the target and action of the medicine, etc.) and any complications (such as if
there was a recurrence, secondary infection, etc.)
Epidemiology– the mode of transmission and preventive measures; indicate whether
the disease is a reportable infectious disease in the U.S. and/or Virginia
Reference citations– 3 to 10 references. Both MLA and APA are acceptable. It is
required to include the article title, the name of author(s), date/year, journal, volume,
page, and so on and the specific hyperlinks (URL) of the particular articles, not the
homepage of the journals, so readers (your instructor and peers) have easy access to
the references.
Response to Your Peers
Your responses include:
1) responding to comments and questions directed to your paper; that is, hosting the
discussion of your own paper; and
2) participating in the discussions of at least three other papers submitted by peers. Each
response should be a minimum of 50 words. Be sure these responses are substantive
(pertain to content and are not just comments such as “That was very interesting”).
Contributing more into the discussion with cited reference(s) is anticipated.
Please know that this is a collaborative learning activity. In support of each other, please
participate in the forum discussions of both your own paper and the papers submitted by
peers. Be supportive, contributory, academic and scientific, ask questions and answer
questions… Make it a stimulating, substantive, robust, and ongoing discussion. Make it a
constructive, supportive, and pleasant learning activity.
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Online BIO 150
Selected Resources for This Assignment
1) Reference to the specific content in the textbook of this course is essential.
2) You should use articles that are published within 24 months from the following sources:
• Nature News http://www.nature.com/news/
• Science News http://www.sciencenews.org/
• US National Library of Medicine at National Institutes of Health
http://www.ncbi.nlm.nih.gov/pubmed
At least one article has to be from the above resources for the recent research in
the area of your selected microbial disease.
3) In addition, the following resources can be helpful; you may use them as optional
resources (for additional support or additional information):
• Healthy Lifestyle http://www.mayoclinic.org/healthy-lifestyle
• Health Library http://my.clevelandclinic.org/health/modules
• Centers for Disease Control and Prevention http://www.cdc.gov/
• Medline Plus http://www.nlm.nih.gov/medlineplus/
• New York Times http://www.nytimes.com/
• NPR http://www.npr.org/sections/health/
4) Reference citation should include (1) The title, the author(s), the date/year of
publication, the name of journal/publisher; (2) The specific hyperlink(s) to the article(s)
you refer to when citing references.
Note: It is the unique link to that particular article you are citing instead of the link to
the homepage of the journal or the publisher.
Plagiarism
Write in your own words and cite the references that you use. This assignment is graded on
the proficiency of reading scientific literature, analyzing and synthesizing information, and
creating your own writing. No credit will be given to a work of copy-and-paste. Copying is an
act of plagiarism. Quotation is reserved for the unavoidable famous phrases only.
If your submission is plagiarized from any source you will receive a zero for this assignment. If it
occurs more than once, you will receive a zero for all Forum assignments in this course.
Submission
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Online BIO 150
1) Please submit your paper through Turnitin in Canvas. Turnitin will check your work
against a database of other students‘ work and against Internet sources and will create
a report. Be sure you write your paper in your own words.
2) Post your paper to the discussion forum titled “Forum 4 – Microbial Diseases” as a new
reply. Put the title of your paper and your name in the first line of your post (For
example, ‘Amy Brown – Lyme Disease’).
Grading
(A) Writing Paper and Hosting Discussion [30 points]
Writing and hosting your paper is worth 30 points toward your course grade. Refer to the
following table to understand how I will grade your submission
Grading Criteria
Essay is thoughtful and reflective. Essay is both long enough and complete enough
to provide relevant and sufficient information for the readers; the information is
organized in a clear and logical way.
Showed good understanding of the subject matter as demonstrated by analyzing
and synthesizing the information from the texts and literature and relating the
information to your personal or professional lives.
Demonstrated ongoing participation in hosting the discussion of his/her own paper
(at least in three different days) and replied to comments and questions.
Responses to peers are substantive, contributory, friendly, and encouraging.
Posting is easy to read without many obvious grammar or spelling mistakes.
Referenced the selected resources. Clearly cited the sources.
Outstanding. Beyond expectation – better/more than the minimum requirements
described above.
Total
Points
8
8
6
2
3
3
30
(B) Discussion [10 points]
Participating in the discussions of peers’ papers is worth 10 points toward your course grade.
Refer to the following table to understand how I will grade your submission
Grading Criteria
Demonstrated ongoing participation in discussion (at least in three different days)
and replied to comments and questions.
Responded to at least three other students’ papers.
Responses to peers are substantive, contributory, friendly, and encouraging.
Outstanding. Beyond expectation – better/more than the minimum requirements
described above.
Total
Points
3
3
3
1
10
4
Online BIO 150
Topics
You may choose any of the following if you have trouble finding a topic; although, you are not
limited to these.
Scalded skin syndrome, necrotizing fasciitis, impetigo
Meningitis
Rubella
Tetanus
Rabies
Botulism
Poliomyelitis
Rheumatic fever
Endocarditis
Lyme disease
Malaria
Pneumonia
Epiglottitis
Pharyngitis
Diphtheria
Otitis media
Pertussis
Tuberculosis
Legionnaires’ disease
Mumps
Food poisoning (bacterial)
Salmonellosis
Typhoid fever
Hepatitis viruses
Gastroenteritis
Gonorrhea
Herpes
Urethritis, cystitis, ureteritis, pyelonephritis, leptospirosis
5
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