Friday, July 23, 1999

Pathophysogy week 2b

Not Me!

All cells have a outer plasma membrane that separate the cell's contents from the extracellular fluid. It provides a physical barrier that separates the inside of the cell from its surrounding environment. It regulates with the environment such as nutrients, waste, and release of secretions. It contains a variety of receptors that helps the cell recognize specific molecules. It provides the cell a stable structure. Cytoplasm consists of material inside the cell from the plasma membrane to the nucleus. Cytoplasm contains all the ingredients for cellular metabolism such as proteins, glucose, electrolytes, and many more depending on the cell's function. The nucleus contains the DNA and enzymes essential for controlling cellular activities. Differentiation is a specialized process that occurs as an embryo. Each cell has all its genetic information intact; however, as the embryo grows, the body dictates what cells need to be produced such as neurons, muscle cells; every cell has their own specialized function and are organized in collections called tissues. Every cell has its own cell cycle and production (mitosis) and the DNA has control over growth and production. If the DNA is altered in the parent cell, the daughter cells contain the same altered cells. All cells need an adequate blood supply, oxygen and nutrition in order to prosper. Hormones stimulates cell growth and reproduction or it may be inhibited by nearby cells. Altered DNA can either mutate in other structures and functions, or cause the cell to die. (Gould, B. E.., pg 96-97, 2011)
The difference between a cancer cell and a normal cell is its growth patterns. Unlike a normal cell, when its time is up, it dies. Cancer cells continue to grow and prosper into mutated cells. Cancer cells can also invade other cells which normal cells cannot. Some cancer cells become neoplasm (tumor). Benign tumors consist of differentiated cells, mitosis is fairly normal, growth is slow, can expand in a mass, most times it is encapsulated and it usually remains localized. Malignant tumors vary in size and are undifferentiated, has an increased mitosis and atypical, has a rapid growth, capable of infiltrating tissues, has no capsule, capable of metastasizing, and become life threating. (Gould, B. E.. , pg 97- 98, 2011)(BreastCancerOverview, pdf, 2011)
Mary is a 35 y.o. Female, 5 foot 3 inches tall, 110 pounds, who has been on oral birth control pills for 5 years, She does regular breast self exams. Her aunt on her mother's side is the only other family member known to have breast cancer. Mary found a lump in her right breast while doing a self exam. She immediately made an appointment with her physician. Other the next few days, she had a physical examination and a mammogram. The mammogram showed a growth and a biopsy was recommended. The biopsy showed cancer and surgery was scheduled.
In Mary's situation, two obvious risk factors were noted, in family history on her mother's side, her aunt had breast cancer. Secondly, Mary was on birth control pills for 5 years and according to the cancer society, 3+ more years on birth control pills can increases the cancer risk for those women; however, if a women stopped taking birth control pills and it has been over 10 years since taking the birth cintrol pills, the risk goes down. Other statistics that were not enclosed in the story are the following: Women who have early menstrual periods before age 12 and went through menopause after 55 have a slight increase of breast cancer due to longer exposure to hormones estrogen and progesterone. The same could be said for women who do not breast feed vs. breast feed their children, there is a decrease risk due to decrease hormonal effects from cessation of the menstrual cycle while breast feeding . Lack of exercise can increase the risk of breast cancer because exercise lowers the hormonal levels, alters metabolism and boosts the immune system. Lastly, woman with dense breast tissue contains more gland tissue and less fatty tissue causing potential problems in mammogram interpretations . (Cancer.org, 2012)



During surgery, a few surrounding lymph nodes were sent to the lab and since some showed cancer cells, a mastectomy was done. Per Mary's wishes, a mastectomy was done on the healthy left breast. After surgery, the breast tissues of both breasts was examined. The lab test found the following: on her right breast, invasive ductal carcinoma; stage 2; Estrogen receptor positive. On her left breast; ductal carcinoma in situ; also ER positive.
Mary's left breast did not show any lumps in her mammogram or on her physical, she still requested if a mastectomy was done on a right, that it would be also be done on her left. Like Mary, other women also choose to have a bilateral (both) mastectomy, especially if one breast contains cancer and the other is healthy in order to decrease their risk for future cancer in the unaffected side. (Cancer.org, 2012)
Per cancer society, the term 'in situ' is used in “early stages of cancer, when it is still confined to the layer of cells where it began”. This preinvasive stage cancer may be present for months or years.
In Mary's case, she elected to have both (bilateral) mastectomy for preventive care. Even with women who option for the bilateral mastectomy, some breast tissue still remains and the risk is greatly decreased; however, cancer can regenerate in the breast tissue that remains. Mary had a biopsy prior to her surgery, I am sure the method of treatment was discussed thoroughly between her and her doctor prior to surgery due to the results of the biopsy. From the biopsy lab test, breast cancer grade are given from one to three. Lower number means slowing growing cancer, and higher number means faster growing cancer. This is also used as a prognosis. Staging of cancer indicates how wide spread the cancer is by the time it is found. It portrays if the cancer is invasive or non-invasive, it also indicates the size of the tumor and if lymph nodes are involved and whether it has metastasize. (Gould, B. E.., pg 99, 2011) (Cancer.org, 2012) (Medicineworld.net, 2012)
Post-op lab results showed that Mary had stage II, invasive ductal (cells lining the milk ducts ) carcinoma with estrogen receptor (ER) positive. This type of cancer had spread out side the duct into the surrounding tissue with no lobe invasion. In order to grow, this type of cancer depends on the hormone estrogen. The lab result on her left breast showed ductal carcinoma in situ (DCIS) with positive ER. This type of cancer is a noninvasive cancer, but if not removed, it could develop into an invasive cancer. It also means that this cancer was only found in the breast ducts and has not spread past the layer of tissue where they began. This type of cancer also relies on the hormone estrogen in order to grow. According to Mary's post-op lab results her left breast cancer would be a stage 0. (Cancer.org, 2012) (Medicineworld.net, 2012)
For Mary, treatment was tailored to her individual cancer. Bilateral mastectomy was performed to removed the cancer that is visible. The next step taken was to lower the risk of recurrence and get rid of any remaining unseen cancer cells that have been left behind (adjuvant therapy). Radiation and hormonal therapy where chosen for her treatment. Radiation therapy is the use of high energy x-rays to kill cancer cells. A radiation regimen consist of a specific number of treatment over a set period of time. Mary was also prescribed tamoxifen for her hormonal therapy. Her type of cancer fuels its growth by the estrogen hormone. Tamoxifen is a drug that blocks estrogen from binding to the cancer cell. It is effective in lowering the risk of recurrence to the breast that had cancer and risk of future recurrence. Tamoxifen can be classified as an antiestrogen or selective estrogen receptor modulators. (Gould, B. E.., pp. 99, 107-110, 11, 2011) (nih.gov, 2012) (medcinenet, 2012)


References

Gould, B. E.. (2011) Chapter 5
(pp. 101-102), Path physiology for the Health Professions, 4th Edition. Saunders Learning, printed in United States.
Gould, B. E.. (2011) Chapter 5
(pp. 96-97), Path physiology for the Health Professions, 4th Edition. Saunders Learning, printed in United States.
Gould, B. E.. (2011) Chapter 5
(pp. 99), Path physiology for the Health Professions, 4th Edition. Saunders Learning, printed in United States.
Gould, B. E.. (2011) Chapter 5
(pp. 107-108), Path physiology for the Health Professions, 4th Edition. Saunders Learning, printed in United States.

Gould, B. E.. (2011) Chapter 5
(pp. 111), Path physiology for the Health Professions, 4th Edition. Saunders Learning, printed in United States.

Anonymous. (2011). Breast Cancer Risk Factors
Retrieved January 15, 2011, from Cancer.org website
http://www.cancer.org/Cancer/BreastCancer/DetailedGuide/breast-cancer-risk-factors
Anonymous. (2011). Tamoxifen
Retrieved January 15, 2011, from NIH website
http://nlm.nih.gov/medicineplus/druginfo/meds/a682414
Anonymous. (2011). Tamoxifen
Retrieved January 15, 2012, from Medcinenet.com website
Http://medcinenet.com/tamoxifen/article.htm
Anonymous. (2011). Breast cancer treatment by stage
Retrieved January 15, 2012, from Medcineworld.org website
medicineworld.org/cancer/breast/treatment/rxbystage.html

Saturday, July 17, 1999

Pathophysiology week 3b

Caution: Fragile!

When we are young and sprite, we believe we are invincible. When we become older, we are programmed to think young regardless of the physical wear and tear changes that occur, it just takes a little longer (life cycle). In the following scenario, Bill is enjoying his retiring life style in ways he enjoys; however back pain may involve some changes.
Bill is a 70 y.o. male who held a desk job until his retirement 5 years ago. Since then, he has spent most of his time working on his stamp collection. Bill has never been very active due to his asthma. He also is a picky eater and does not like dairy products. Bill and his wife do take a daily walk around the neighborhood. One day while on their walk, Bill begins to complain of back pain. The next day, the pain is worse and Bill's wife insists that he see the doctor.
Bill suffers from asthma. Asthma is an chronic allergic lung disorder that inflames, creates swelling and narrows the airways. Because the airways are already inflamed, certain factors promote episodes of breathing difficulties called asthmatic attacks. The factors that can trigger an asthmatic attack include allergens, environmental agents, exercise, or infection. When asthmatic attack occurs narrowing of the airway occurs the same way regardless of the stimuli factor as the following: The inflamed mucosa causes edema (swelling), broncho constriction of the smooth muscle occurs, and increase thick stick mucus. According to the National Heart Lung and Blood Institute inhaled corticosteroids are the preferred medicines for long-term control for asthma. It helps reduced inflammation and helps prevents symptoms caused by asthma. Corticosteroid pills and liquids are only used short term in order to control severe cases of asthma. Prolong use of pill/liquid corticosteroid can raise the risk of cataracts and osteoporosis. (nih, 2012)
The doctor does an x-ray which shows a compression fracture in Bill's L1 vertebrae. As a follow-up, the doctor also orders a Bone Mineral Density Test. This test comes back with a T score of -2.8. The doctor prescribes a pain reliever for Bill's back pain and a course of treatment for the diagnosed disease.
Our skeletal system has many primary functions such as body's structural support, storage for calcium, contributes to blood cell production, protection of the soft tissues in the body, and gives our body leverage in order to assist our muscles in movement. When we are younger, our bones are in a frequent manufacturing mode throughout the year building bone mass ( bone density) by absorbing calcium and removing protein and mineral components. After 30s the body starts to reabsorb calcium faster than the bones can rebuild leading to a net loss in bone mass as we age. This net loss of bone mass (bone density) cause the bones to become more fragile and a candidate for fractures especially in the spine, hip and wrist.
Osteoporosis occurs when there is a marked loss of bone density and a increase in bone porosity. This condition is frequently seen the aging. There is usually no symptoms until the damage has already occurred such as back pain, loss of height and fractures of vertebrae, hips, wrist and other bones. Unlike hip fractures, fractures in the spine do not need an incident like a fall to occur. The spine may have become so weakened that it just starts to compress. There is many risk factors that can make a person prone to osteoporosis. Some of these factors are the following: You are an older person; You are a woman; Decrease estrogen levels especially after menopause; For men, low testosterone levels; Have a sedentary life style; Decreased intake of vitamin D, C, and calcium; Heredity; and Take corticosteroid drugs. (NIH.gov)
Men have more bone mass than women; whereas men in their 50s are loosing bone mass at a very slow rate compared to women after menopause. By the time men reach their mid sixties – 70, men and women lose bone density at the same rate. This is a possible reason why men are not diagnose with osteoporosis until a fracture actually happens because women are having bone density tests earlier in life. (about, 2012)

Diagnosis of osteoporosis can be done by simply having a bone mineral density test called DXA or DEXA ( Dual-energy X-ray absorptiometry) that measures bone loss. DXA is the standard for measuring bone mineral density. A Lateral Vertebral Assessment (LVA) is a low -dose x-ray examination of the spine to screen for vertebral fractures is also performed on the DXA, especially if a person has lost in height, or have an unexplained back pain, or if the DXA scan gives a borderline reading. Radiation from the DXA is lower than a chest x-ray. The DXA works by sending out a low-dose x-rays with two distinct energy peaks through the bones being examine. One peak is absorbed by soft tissue and other is absorbed by bone. The bone density measurement results is by subtracting the soft tissue amount from the total. The test results are in two forms. The 'T' score is the amount of a person's bone compared to a young adult of the same gender, which are the following: A score above
[ -1 ] is considered normal. A score between [ -1 ] and [ -2.5 ] is classified as low bone mass (osteopenia). A score below [ -2.5 ] is defined as osteoporosis. T score estimates your risk of developing fractures. A 'Z' score reflects the amount of bone a person's has compared others in the same age group. Score is usually high or low, indicating a need for further testing. Bills T score was
[-2.8]. Bill T score is classified as osteoporosis accordingly to the DXA test results. (radiologyinfo, 2012)
Bills history, supports his risks for osteoporosis. His use of asthma medications which could be either glucocorticoids or corticosteroid puts him at risk for bone loss. The gluccorticoid is an anti-infla mmatory drug decreases calcium absorption from food, decreases bone formation, and increases calcium excretion in the kidneys. The corticosteroid drug can interfere with sex hormone production, promote muscle and bone loss. Most of Bills activity is mostly sedentary due to his asthma, although he does take daily walks which is a plus. He also does not eat well and does not take in dairy products. Lastly his age makes him an obvious risk. His increasing back pain after a walk was the only symptom that made him go to a physician. The x-ray report showing a compressed (collapse) fracture the L1of the vertebrae which probably cause his pain. The vertebrae (lumbar region) is a region that bears most of the body weight. The Bone Mineral Density Test (DXA) T results was scored [-2.8]. Both x-ray and DXA medical findings support Bill's diagnosis.
Bill's treatment management will possibly require a increase calcium and vitamin D diet intake, with the emphasis in a calcium supplement of 1200-1500 mg daily and a vitamin D of 600 -800 units a day. Continue to encourage a more active life style along with his daily weight bearing exercise to prevent bone loss, which he already does by walking. Bill's physician will probably manage both asthma and osteoporosis by balancing medication that will benefit Bill with least side effects. For his asthma, the physician may put Bill on a glucocorticoid ( hydrocortisone or prednisone) inhaler instead of oral, at a lower dose and encourage shorter time of use. For osteoporosis, treatment would consist of anti-resorptive agents which inhibit bone reabsorption. Bisphosphonates is a class of drugs that inhibits breaking down of bone, decreasing the risk for hip, wrist, and spinal fracture. One example of this drug would be Fosamax ( bisphosphonate anti-resorptive medication) which has shown to increase bone density in men. Another example, Actonel (bisphosphonate anti-resorptive ) is a better medication for those people who have osteoporosis caused by cortisone related medication, which may be indicated in Bill's case. This medication is more potent in resorption of bone than Fosamax and is less irritating to the esophagus.




References
Anonymous. (2012). How Is Asthma Treated and Controlled?
Retrieved January 20, 2012, from Nhlbi.nih.gov website
http://www.nhlbi.nih.gov/health/health-topics/topics/asthma/treatment.html
Anonymous. (2012). What is Asthma?
Retrieved January 20, 2012, from Nhlbi.nih.gov website
http://www.nhlbi.nih.gov/health/health-topics/topics/asthma/
Anonymous. (2011, January). What People With Asthma Need to Know About Osteoporosis
Retrieved January 20, 2012, from Nhlbi.nih.gov website
http://www.niams.nih.gov/Health_Info/Bone/Osteoporosis/Conditions_Behaviors/asthma.asp
Anonymous. (2012). Bone Density Scan
Retrieved January 20, 2012, from Radiologyinfo website
http://www.radiologyinfo.org/en/info.cfm?pg=dexa
Bihari, M. MD. (2008, November 25). Osteoporos for men
Retrieved January 20, 2012, from About website
http://drugs.about.com/od/osteoporosismedications/a/osteoporos_men.htm
Anonymous. (2012). Osteoporosis medications
Retrieved January 20, 2012, from ACAAI website
http://www.acaai.org/allergist/asthma/conditions/osteoporosis-and-asthma/Pages/osteoporosis-medications.aspx


Gould, B. E.. (2011) Chapter 10
(pp. 180), Path physiology for the Health Professions, 4th Edition. Saunders Learning, printed in United States.

Thursday, July 15, 1999

Pathophysiology week 3

I'm Just Tired
You have to love the our immune system. “ You must remember this. A kiss is not just a kiss..., ” is a partial lyrics in a song sung in the classic movie “Casablanca”. The above lyrics is a clue how infectious mononucleosis can be spread. Unknown to any one person, the saliva in the mouth may harbor the Epstein-Barr ( EBV) virus. In part, this may be what happened in the following scenario.
Karen is a 17 y.o. Female basketball player who has been suffering from fatigue. It is beginning to interfere with her playing, and her team is expected to go to the playoffs this year. She also has a sore throat. Karen believes she is just not getting enough sleep due to games and being out with her boyfriend. However, her mother insists she visit the doctor.
Infectious mononucleosis is a common illness caused by Epstein-Barr virus(EBV). EBV is categorize in the herpes virus group. The primary transmission source of EBV is a person-to-person contact with saliva; however in a few cases transmission may occur through air ( droplet in sneezing or coughing) or blood. The EBV exposure eventually leads to the infection of the B lymphocytes in the epithelial cells of the nasopharynx and oropharynx In the United States, 95 % of adults between the ages of 30-45 years of age have already been exposed to the EBV and have antibodies (immunity) that can target the virus. Thus, sometime during their life span, these people have been infected with EBV. Thanks to the immune system, the antibodies that targets the EBV cells, produces a life long immunity. However, the EBV can become dormant and remain in a few epithelial cells in the throat and blood. In some healthy people, this stealth-like nature of the EBV reactivates in the person's saliva, causes no symptoms and , the person then becomes a carrier, shedding the EBV without his/hers knowledge of its existence. According to the Center of Disease and Control (CDC), this may be one reason why EBV is world wide and difficult to prevent. These same people can secrete the EBV through out their life time due to the periods of reactivation. Most children who have been exposed to EBV do not have any symptoms or are treated for having other mild childhood illnesses. In teenagers and young adults, symptomatic conditions and signs of mononucleosis, usually occurs in 35-50% of the cases per National Center of Infectious Disease. Incubation period (time from the initial infection to the appearance of symptoms) for mononucleosis is approximately 4 -8 weeks. Contagious period is usually
during the infection period and weeks after ward. (pg 164-165)( cdc.gov, 2011)(aafp, 2004)
The physician finds Karen has swollen lymph nodes; an enlarged spleen; and tonsillitis. The lab test come back with the following findings: CBC: Increased WBC; normal RBC. Liver Function Test: Increase liver enzymes. Heterophil antibody test : positive.
Clinical symptoms and signs of mononucleosis involve sore throat (80-90%), fever, headache, malaise (lack of energy), fatigue, temporary rash on trunk, enlarged (swollen) lymph nodes/glands (lymphadenopathy), enlarged spleen (splenomegly) and the age factor. Diagnostic measures are also taken to confirm or rule out other illnesses/causes. Lab test that narrow in on certain symptoms or signs such as culture for sore throat or fever, blood chemistry test to reveal infection or abnormal liver functions, and a heterophil antibody test (Monospot test), which is sensitive to specific antibodies made in the immune system. An elevated white count( increase in lymphacytes and monocytes ), an increase or presence of atypical T-lymphacytes, and a positive heterophil test confirms the diagnosis. ( cdc.gov, 2012)( Gould, B. E, pg 165, 2011)(aafp, 2004)(labtestonline, 2012)
Karen's physician likely suspected Karen's diagnosis as mononucleosis due to Karen's symptoms, signs and physical exam. Karen was in the right age group, suffered fatigue, malaise, and had a sore throat. Her exposure to saliva could have come from any one she was close to. Number one, it could have come from her boy friend. Number two, one or more of her family members or friends, where she may shared a bite of cake or another food item where the utensil or food may have saliva on it. It could be any number of situations where saliva maybe exchanged.
Karen's physical exam noted swollen lymph nodes, an enlarge spleen, and tonsillitis. Karen's lab results showed an increase in WBCs and normal RBCs, an increase liver enzymes obtained from the liver function test, and a positive Heterophil Antibody Test. The increase liver enzymes only indicates that there is some liver inflammation, with mono the liver enzymes usually return to normal without treatment. The lab results along with the Heterophil Antibody Test confirmed Karen's diagnosis. Karen had to have mono for a period of time in order to obtain an acceptable amount antibodies made by the immune system for the Heterophil Antibody Test to become positive, approximately 1-4 weeks. ( immunity cycle).
Karen's doctors prescribes a treatment regimen and tells her she may not play basketball for at least one month and she needs an exam before she resumes playing. Karen is disappointed she cannot play basketball, but is happy that the doctor says she will never get this disease again.
Since mononucleosis is viral, Karen's physician more than likely prescribed comfort and supportive measures that would help in relieving her symptoms, such as plenty of rest, or an over-the-counter analgesic like tylenol or motrin for temporary relief from discomfort (no aspirin in her age group due to Reyes syndrome), and fluid hydration. It also might be possible that Karen's tonsillitis is a bacterial infection, secondary affect of mono. An antibacterial drug would be prescribed ( ampicillin and amoxicillin should be avoided due body rash potential in people with mono, thus mistaken as an allergy) . If not, gargling with salt water is one home-made treatment that could be used to soothe the soreness in her throat along with others temporary remedies , such sucking on a Popsicle or warm drinks etc. (medicinenet, 2010)
The spleen is fragile and important part of the immune system. It filters blood, stores iron from recycle RBCs, removes abnormal blood cells, and initiates response of B cells and T cells in the blood. Splenomegaly (enlarged spleen) caused by mono, makes it vulnerable to injury. Karen's physician requested no basketball for a month most likely due to the spleen's vulnerability to injury. A follow up clinic visit was needed in order to evaluate the spleen before Karen resumes basketball. (webmd,
As mentioned earlier, Karen does not have to worry about getting the disease again; she has life time immunity. At the present, she only needs to concern herself in getting better with lots of hugs with no kisses from her family, friends, and boyfriend.

References
Anonymous. (2012). Epstein-Barr Virus and Infectious Mononucleosis
Retrieved January 20, 2012, from CDC.gov website
http://www.cdc.gov/ncidod/diseases/ebv.htm
Ebell, M.H.. (2004, October, 1). Epstein-Barr Virus Infectious Mononucleosis
Retrieved January 20, 2012, from CDC.gov website
http://www.aafp.org/afp/2004/1001/p1279.html
Anonymous. (2012). Epstein-Barr Virus Antibodies
Retrieved January 20, 2012, from CDC.gov website
http://labtestsonline.org/understanding/analytes/ebv/tab/test
Anonymous. (2010, April 19). Spleen
Retrieved January 20, 2012, from webmd.com website
http://www.webmd.com/digestive-disorders/picture-of-the-spleen
Stöppler, M.C. (2012). Infectious Mononucleosis
Retrieved January 20, 2012, from medicinenet website
http://www.medicinenet.com/infectious_mononucleosis/page3.htm#6whatis

Gould, B. E.. (2011) Chapter 10
(pp. 165), Path physiology for the Health Professions, 4th Edition. Saunders Learning, printed in United States.

Structure and Function of the Human Body week 7

1. Compare and contrast non-specific and specific immunity. What is the difference between innate immunity, acquired immunity, active immunity, and passive immunity?

The immunity system works two ways. Non-specifically and specifically. The main difference between non-specific immunity and specific immunity have to do with the following: the response time, non-antigen specific vs. antigen specific and no memory vs. memory after exposure from the pathogen, foreign matter or abnormal cell.
In non-specific immunity (present at birth ) defense barriers are always present, capable of targeting non-specific antigens, has no immunological memory (immediate action only), and responds more immediate to invading organisms. In other words, the main function of non-specific immunity is preventing microbes from entering into the body by targeting antigens before hand or isolating them if microbes does enter the body, as in an inflammatory response (temporary repair, slows the spread of pathogen, and helps with tissue regeneration). An intact skin is the first line of defense for non-specific immunity. The skin prevents invasion of microbes. Other body defense surfaces includes mechanical and tactile protection the hair provides on the scalp and other parts of the body, sweat and sebaceous glands found in the epidermal (that flushes and washes away microbes and chemical agents), and epithelium lining in the digestive, respiratory, and urinary tract where acidity, enzymes, and mucus are secreted. Microbes are caught in the mucous found in the nose and respiratory. The stomach's acidity produces an environment that can hinder microbe growth or can destroy the microbe. Mucous in the urinary track attract microbes and flushes them out of the body. (pg 480)

Also included in non-specific immunity is phagocytes, the first line of cellular defense. There are two classes of phagocytes, microphages and macrophages. These 'Pac-Man' cells circulate in the blood system and enter the peripheral tissue, looking for microbes and pathogens to surround, and destroy. They are usually the first to encounter infection. (pg 479-480)

In the immunological surveillance, our body's immune system is surveying for abnormal cells to attack and destroy. This involves lymphocyte,NK (natural killer)cells. The NK cells pick up antigens on abnormal cells membranes. (pg 480)

The interferons are small proteins released by activated lymphocytes, macrophages, and tissue cells that have been exposed to a virus. In essence, cellular exposure with interferons produces anti-viral proteins; thereby, prevents viral replication inside the cell and slows the spread of the virus.

The complement system (complements antibodies' action) attacks and breaks down. Complement activation attracts phagocytes, stimulates phagocytosis, destroys plasma membranes (breaks down cellular walls), and stimulates inflammation. (pg 480-481)

In the inflammation process, mast cells play an important role. Mast cells are found in connective tissue and their main duty is to release chemicals that activates the body's defenses after an injury or infection. Once the mast cell is activated, blood flow increases, phagocytes are activated, capillary permeability increases the inflammation response, clotting reaction walls off region, regional temperature is increased, and specific defenses are activated. (pg 480)

In specific immunity, there is a lag time between exposure to the antigen and maximum response (antibodies). T-cells and B cells are naturally programmed in the bone marrow and thymus to attack only specific (nonself) antigens and not normal (self)body antigens found on normal cells. T-cells provide defense against abnormal cells and pathogens inside living cells (cell mediated immunity). B-cells provide defense against antigens and pathogens in body fluid (antibody-mediated immunity). Exposure to the pathogen or foreign cell results in immunological memory.

There are also two types of specific immunity, innate and acquired. Innate immunity is the genetically determined at birth and has no prior exposure to the antigen involved. The acquired immunity occurs when prior exposure and antibody production exist. Active and passive immunity are subdivision of acquired immunity. Active immunity is produced when specific antibodies develop in response to specific antigens. Active immunity can either occur through natural ( environmental) means or induced ( administration of antigens) means. Passive immunity is produced by transfer of antibodies from another person. Passive immunity can also occur through natural means such as in maternal breast milk or transferred of maternal antibodies across the placenta. (pg 482-483)

2. Explain the pathway of lymph once it enters into the lymphatic vessels to being “dumped” back into the blood stream. What materials or items could be found in the lymph? What happens to the lymph when it goes through the lymph node?

Unlike our circulatory system, where the blood stream is pumped by the heart, the lymphatic system is only a one way system that flows upward from the extremities (feet and hands), through the body towards the neck. This is accomplished through the normal movement of the respiratory and skeletal muscles and the overlapping arrangement of the endothelial cells found in the lymphatic vessels that promotes forward movement and prevents backflow. (pg 473)

Since the lymphatic vessels run parallel to the venous system, the start of the lymphatic system begins with the lymphatic capillaries which begins as a blind pockets in the peripheral tissue. These capillaries are lined with simple squamous epithelium and lack a basement membrane. This permits permeability of fluids, solids, and waste to flow into the lymphatic capillaries. (pg 473)

Lymphatic capillaries eventually flows into larger lymphatic vessels that eventually leads toward the trunk of the body. Like the venous system, valves are needed in the larger lymphatic vessels to prevent back flow due to the pressure in the vessel is low. The larger lymphatic vessels empty into two large lymphatic ducts, thoracic duct and right lymphatic duct. The thoracic duct collects lymph from the lower abdomen, pelvis, lower limbs and from the left half of the head, neck, and chest. It finally empties into the venous system near the junction between the left jugular vein and the left subclavian vein. The right lymphatic duct covers a smaller area. The right lymphatic duct collects lymph from the upper right quadrant of the body, the right arm, and the right side of the head and neck. It empties into the right subclavian vein (which is blood) that eventually goes into the right atrium of the heart back into the circulatory. I can imagine anything that leaks out from the tissue into the interstitial fluid leaks into the lymphatic capillaries; therefore, the thin epithelium found in the lymphatic capillaries permits water, protein molecules and other molecules, virus, bacteria, fungi and other pathogens are carried in the lymph. (pg 473)

When the lymph is processed through the lymph node, a filtration process is taking place removing waste products, some excess fluids, and purifying lymph fluid before it reaches the venous system. Afferent lymphatic vessels carry unfiltered lymph fluid through the nose. When the lymph flows through the sinuses of the lymph node, 99% of antigens are removed by macrophages (white blood cells). As the antigens are spotted and removed, this stimulates the T-cells and B-cells to activate which initiates the immune response. After the purification of the lymph fluid, the fluid is returned to the venous circulatory system through the efferent lymphatic vessels.

3. Compare and contrast T-lymphocytes and B-lymphocytes specific immunity mechanisms. In specific immunity, why does exposure (1st exposure compared to 2nd and subsequent exposures) matter?

Cells recognize antigens when those antigens are bound to membrane receptors of other cells. The structure of these antigen-binding membrane receptors is generally determine. Membrane receptors are called major histocompatibility complier (MHC) proteins. There are tow classes of MHC. Class I MHC protein are found in the plasma membrane of all nucleated cells. Class II MHC proteins are found in the membranes of lymphocytes of antigen – presenting cells (APC)
Class I MCH is MCH bend of display small peplicales molecules (chain of amino acid that are activated either by recognition such as in organ donation or by contact as in viral or bacterial which results in destruction of the abnormal cell. Class II MCH activate 7 cells to attack foreign cells, including bacteria and foreign proteins such as microglia in the CNS and macrophages in the liver (keep their cells) After the ACC breakdown the foreign antigens / pathogens – fragments of the foreign antigens are imprinted on their cell surfaces bound to class II MHC protein. T Cells that come in contract are APC membrane become activated initiating an immune response activating of T cell only occurs when MHC protein contains the specific antigen the T cell is program to detect T cells divide and differentiate into cells specific function in the immune response. These types are cytotoxic T cells, helper T cells, memory T cells and suppressor T Cells. (pg 486-488)

Cytotoxen T cells (killer t-cells) responsible for all medicated immunity they are activated by exposure to antigens bound to class I MHC proteins. They destroy their target by the following specific secretions: lymphotorein disrupt the cell metabolism, cytocrine tell the cell genes to die and perform which destructs the plasma membrane. T cells are activated by exposure to antigen bound to Class II MHC helper T Cells are activated by exposure to antigen bound to class II MHC proteins on antigen presenting cells through activation they divide to produce memory cells and more helper T cells. (pg 486-488)

Cytotoxin T cells and helper T cells developing into memory T cells these cell remain in reserve until the same antigen appears a second time around in which case they will become either cytotoxic T cells or helper T cells and enhance in speed and effectiveness of the immune response. Suppressor T cells have their major job which is to put the brakes on the response of other T cells and B cells by secreting cytolysis called suppression factors – suppression cells act after the initial immune system. (pg 486-488)

Initial response to antigen exposure is called primary response. Primary response takes approximately one-two weeks to develop peak antibody levels after exposure then recline. ICM modules are the first to appear in the blood stream followed by a slow rise in IGC. Secondly, in the primary response, antigens must activate specific B cells and B cells must then respond by differentiating into plasma cells. Memory B cells do not differentiate into plasma until cells are exposed to the same antigen a second time. After the 2nd exposure occurs, memory B cells respond quickly by dividing and differentiating into plasma cells that then secrete massive amount of antibodies. (pg 486-488)

During the second response, the body is ready with antibodies. The response is faster and stronger. The memory cells are already equipped to attack even with low levels of antigens. Immunization looks as a secondary response. because it stimulates the production of memory B cells under controlled condition. (pg 486-488)

B cells launch a chemical attack on antigens by going through a series of events that result in production of specific antibodies. Each B cells carries its own antibody molecule in its cell membrane. When a corresponding antigen appears in the interstitial luid gets well bound by B cells antibodies. The antigen enters the b cell by endocytosis and become displayed on class II MHC protein surface this is called sensitized activated help T cells encounting the antigen on the sensitizing B cell then release cytogens that trigger the activation of the B cell. The B cell then divides producing memory B cells and plasma cells that secrete antibodies.
Memory B cells like memory T cells remain on reserve to respond until second exposure of the same centigen at which time they respond by differenting into antibodies and secreting plasma cells. (pg 486-488)

Antigen antibody binding occurs between antigen binding sets on the antibody and antigenric determinant sites on the antigen. When an antibody molecule binds to its specific antigen an antigen antibody complex is formed. This is where they bind to certain positions of its exposed surface called antigenic determinate sites. (pg 486-488)

4. Immune responses are consistently occurring within our body and involve many complex steps. For the most part these mechanisms perform very well but there are 3 categories of complications and/or dysfunction that can occur within the immune system. List and describe each category and the cause of the dysfunction.

There are three classes of disorders that can result from a malfunctioning immune system. Autoimmune system is one class that targets normal (self) cells' antigens and tissues as foreign invaders. This causes the B-cells to produce specific antibodies to attack normal cells and tissues. These antibodies are called autoantibodies. Examples of autoimmune deficiency disorder is a situation that occurs in IDDM (insulin-dependent diabetes mellitus) where the auto-antibodies attack cells in the pancreatic islets. Another situation that can occur under autoimmune disorder is when antibodies start to associate normal protein amino acids sequencing with those of several viruses. Many viruses' proteins contain amino acids that closely resembles the amino acid sequence found in the nervous system protein. Complications caused by a viral infection or vaccination can result in a decease such as multiple sclerosis. Lastly, autoimmune disorder can be found in people who have an unusual genetic MHC (major histocompatibility complex) protein. People with this defect may sub-comb to such diseases as rheumatoid arthritis, grave's disease, psoriasis or pernicious anemia.

Immune deficiency disease is another class. In this case, there is an abnormal development of the immune system or the immune response is blocked. Children with SCIDC (severe combined immunodeficiency deceases) get to developed cell on immune response, total protected infected. Aids is another immunodeficiency decease caused by viral infection that targets helper T-cells which eventually causes an immune response to malfunctionencies.

Allergies is a third classes of the immune diffidences caused by antigens called allergens. In this case, the immune responds inappropriately excessively to the allergies. Immune hypersensitivity is a rapid form response to an antigen. The initial exposure does not trigger a response allergic reaction, but only lets the stage for a prone aggressive response second time around. The initial response only starts the process for IGE antibodies production and attach themselves to the cell membrane of the aphelia and mast cells. Later with the second exposure, these cells are activated and release histamine, heparin, several cytoganis, prostoglancilins, and other chemical into the surrounding tissues. The severity depends on the person's sensitively on areas envalve such as the body surface. - inflammation is restricted to that area, blood stream could be devastating in area prophylaxis is where the allergen affects the mast cells producing a severe reaction or even lethal reaction. The affects can produce cells-producing capillaries in the smooth muscle causing difficult breathing and of severe vasodilation causing circulatory collapse in the airway (Cana-phylactic shock)


5. Why can fevers be a good mechanism for the body? Why can they be a bad mechanism?
Fever is any temperature higher than 99°Fahrenheit. Fever is also your body's reaction to infection and illness. It helps the body to fight infections. Fever is only a symptom – along with other symptoms helps one determine your illness.
Fever as high as 103°for short time is helpful, because it helps the body fight infection by increasing the rate of metabolism, which enhances the phagocytosis, and increase enzymatic reaction. Fever occurs when the body's immune response is triggered by a protein called pyrogen (fever producing) . Pyrogens usually come from an outside source of the body and can stimulate production the inside of the body. Pyrogens causes the hypothalamus to increase the temperature set point (higher than 98.6° as an example). Examples of outside pyrogens are viruses, bacteria, fungi, and toxins.
High fevers over a long duration can cause problems for the body such as dehydration, and CNS problems which over the long run can be lethal to the body's homeostasis.

Friday, July 09, 1999

Pathophysogy week 2a

The inflammation process is our body's attempt to zero-in, confine, and repair damaged tissue cells cause by a pathogenic invasion that can occur when the body's first line of defense, the skin, has been broken. In other words, it is the body's natural means in restoring its homeostasis status after a tissue has been injured.
When an injury occurs, the insult stimulates the connective tissue cells (mast cells) and platelets to release chemical mediators such as histamine and heparin. This action causes the injured area blood vessels to dilate and become more permeable. The increase blood flow (hyperemia) to the injured region makes the area warm and reddened, while at the same time, diffusion (protein and fluid shift) of the blood plasma creates swelling in the injured region. The increase pressure from fluid and the chemicals released by the mast cells also activates the nerve endings, causing pain. In some cases, depending on injured area, a loss of function can occur because of the swelling and lack of nutrition to the area's cells. Leukocytes are rapidly attracted to the injured site by mears of chemotaxis,a chemical signal released by the injured cells. Phagocytes become the first line of cellular defense, moving out of the blood stream and interring the injured tissue by squeezing between adjacent cells in the capillary wall (diapedesis). Macrophages remove the cause and the debris (phagocytosis) in order for healing to take place. If the causative agent is not removed, inflammatory response will continue until it is. (Gould, B.E., pp 19 – 21, 22 – 23, 2011)
Richard, a 50 y/o father, fishing with his family in the bounty waters, started out his day with the joy in catching northern pike and days later, ended receiving antibiotics. The events that place cascade from one small mishap, a fish bite. Factors that allow the infection to spread prior to Richard's emergency visit will be pointed out the following narrative along with the answers to the remaining questions.

Richard's son caught a large northern pike. As the fish was brought in, it came off the hook and landed on the bottom of the canoe. Richard manage to subdue the fish and put it on the stringer, but in the process, the fish bit his finger. This caused a puncture and some bleeding at the base of the finger nail on the right ring finger. The wound was washed with boiled water and a Band-Aid applied which he wore for only one day until the bleeding stopped.
The moment the protective skin barrier was broken, the punctured wound ( fish bite) at the base of his finger nail provided a direct avenue for microorganism. Unknown to Richard, a tooth ( foreign body) from the northern pike was embedded in the puncture wound. The embedded tooth was full of germs, thus infection was inevitable. No antibacterial ointment was ever applied and the puncture wound was only Band Aided for one day (no mention of if Band-Aid was changed). The inflammation response was initiated when Richard was bitten by the fish.
Four days later, while at work, Richard noticed that he kept bumping the injured finger and that it was very sore. That evening, he ask his wife (an allied heath professional) about the soreness and she recommended washing it out again and applying a Band-Aid to protect it. The next night , 5 days after the injury, Richard came home and showed his wife his hand and arm. His wound was swollen and white with pus, and his arm now had red streaks to the shoulder. They immediately went to the emergency room and he was put on IV antibiotics. After two days of treatment, Richard was changing the bandage when he noticed a northern fish tooth had come out of the wound with the pus.
Even though the injured finger did not have protected covering from the environment, which it probably should have, the site was never iced, elevated, rested nor monitored for infection since day one and prior to evening on day four, when Richard ask his wife about the soreness. Richard's complaint of soreness in the the injured finger indicated that the inflammation was still in progress and infection had already begun due to the embedded northern pike's tooth (foreign body). Even if the northern pike's tooth was discovered a day or two earlier, contamination had already occurred with the fish's bite. The only possible advantage could be that the infection would be less evasive and Richard possibly only needed to be on oral antibiotics. Secondly, the wound was unprotected when Richard was at work, which may have provided more exposure to more microorganism, especially in his line of work.
Instead, on day five after the injury, Richard's wound was swollen and white with pus and his arm had red streaks to the shoulder. Pus is a purulent exudate that consist of collection of interstitial fluid formed in the inflamed area. Pus is usually thick in consistency, yellow-green in color, and contains leukocytes, cell debris, and microorganisms. Formation of pus found on Richards was a marker for a bacterial infection. The swollen and white wound indicated edema caused by the fluid shift in the interstitial space due to inflammation process. The red streaks found on Richard's arm indicated that the infection had begun to spread . Red streaks do not necessary mean sepsis however, it could eventually occult if immediate treatment was not taken. In Richard's case, the red streaking in the skin may possibly mean that the bacteria had spread into the lymphatic channels, causing lymphangitis; therefore, a excellent reason why Richard was put on IV antibacterial drug, a possible broad spectrum drug,in order to deliver a immediate loading dose and achieve an adequate blood level to effectively treat the infection. Along with help of IV antibacterial drug and the northern pike's tooth (causative agent) being expelled, Richard's injured finger can now start the healing process through skin regeneration. (Gould, B.E , pg 20,26,86, 2011)
The IV treatments were given on an outpatient basis. Richard spent 3 hours, twice a day for 3 days receiving antibiotics. An IV port was left in his arm and wrapped to protect it at work. However, when it was discovered he worked in the sewer system, he was instructed not to return to work until the infection was gone.
Richard already had one encounter with infection from the fish's bite, returning to work with the IV port, would have advance his risk for another infection. Working in a sewer system has to be a microorganism minefield.

References
Gould, B. E.. (2011) Chapter 2
(pp. 19-23), Path physiology for the Health Professions, 4th Edition. Saunders Learning, printed in United States.
Gould, B. E.. (2011) Chapter 2
(pp. 26), Path physiology for the Health Professions, 4th Edition. Saunders Learning, printed in United States.
Gould, B. E.. (2011) Chapter 4
(pp. 86), Path physiology for the Health Professions, 4th Edition. Saunders Learning, printed in United States.