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Q1 : A female patient with rheumatoid arthritis suffers from renal
failure. Renal biopsy shows deposition of eosinophilic material in the
wall of renal arterioles. This material appears as non-branching fibrils
by electron microscopy.
a. what is the name of this material and what is its chemical
composition?
its name is amyloid, its chemical composition:
Approximately 95% of amyloid deposits are made up of fibrillar
proteins. The remaining 5% are glycoproteins.
Two chemically distinct major classes of amyloid fibrillar proteins
have been identified:
1. amyloid light chain (AL) : it is derived form plasma cells (
immimocytes) and contains Ig light chains.
2. Amyloid associated (AA) is a non immunoglobulin protein
synthesized by the liver.
Other proteins are transthyretin, B2 –macroglobulin and B2 –
amyloid proteins.
b. Mention the special stains specific for this material?
1.Cogno red : appears pink or red by light microscope. A green
birefringeness is seen by polarized light.
2.Methyl violet (metachromatic stain): appears pink.
3.Immunohistochemistry: appears brown using antibodies specific to
various amyloid subtypes of fibrils.
c. Describe the gross picture of the kidney in such condition and
mention a stain that demonstrates it grossly?
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It is enlarged, pale grey, waxy and firm. Later on, it becomes
contracted due to chronic vascular occlusion by amyloid deposits.
The stain is iodine, when added to fresh specimen containing amyloid a
brown coloration is developed, that turns to bluish violet when
sulphuric acid is added.
Q2 :Explain how molecular mimicry can cause autoimmune diseases.
Give an example.
Some infections share the same epitopes (antigenic determinants)
with self antigens. Thus an immune response against such
microbes may produce tissue damaging reactions against self
antigens. E.g. rheumatic fever which follows streptococcal
infection, the antibody against the streptococcal M protein cross
react with cardiac glycoproteins.
Q3 :Give a short account on the problems associated with Neoplasia.
1. Anemia: it is due to chronic blood loss ( usually associated with
gastrointestinal or genitourinary neoplasms) , an iron deficiency
anemia may be responsible for the initial symptoms of cancer such as
weakness and fatigue. Anemia may also result from poor nutrition
especially in oral and esophageal cancers or from metastatic
replacement of the red-cell producing bone marrow.
2. loss of function: can result from the mass effect of cancer or from
replacement of normal tissue.
3. Malnutrition and cachexia:
Cachexia is defined as a state of general weakness, wasting and loss of
body fat.
Malnutrition: is due to loss of appetite especially noticed in cancer of
head and neck or upper gastrointestinal tract. Some times malnutrition
is due to nausea and vomiting resulting from radiotherapy and /or
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chemotherapy. Furthermore, carcinoma may produce substances that
interfere with intestinal absorption or produce diarrhea. Recently novel
proteoglycans that cause breakdown of skeletal muscle proteins have
been detected in the urine of cancer patients.
4. Infections: are common among cancer patients. Sit is due to
obstructive neoplasms which cause obstruction of a bronchus leading
to post-obstructive infection such as bronchiactasis and/or pneumonia.
Also, altered host resistance ma permit relatively avirulent organisms
e.g. normal bacterial flora, as well as common viruses and fungi to
cause infection and death.
5. paraneoplastic syndromes: these are symptom complexes seen in
cancer patients. These symptoms are neither caused by the tumor
itself nor by its metastases or by hormones secreted by the tumor
tissue of origin, but it is due to ectopic hormonal production (e.g. ACTH
may be increased in some forms of lung cancer leading to Cushing's
syndrome) that may be a life threatening clinical problem.
Q4 :List the types of acute suppurative inflammation.
a. Localized: abscess, boil, stye, carbuncle.
b. Diffuse: cellulitis, phlegmonous, empyema.
Q5 :Enumerated complications of wound healing.
1. Keloid.
2. Exuberant granulation or proud flesh.
3. Contracture.
4. Wound dehiscence (split-apart/ rupture of a wound).
5. Weak scars.
6. Painful.
7. Implantations.
8. Neoplasia.
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Q6 ) Enumerate the mechanisms of conversion of proto-oncogens
to oncogenes with an example.
1. Point mutation. E.g. epidermal gross factor receptor (EGFR)
2. Gene amplification
3. chromosome rearrangement.
Q7)Explain the role of p53 tumor suppressor gene.
It is a nuclear phosphoprotein and acts as a transcriptional
regulator ( regulating certain genes that participate in cell cycle)
The level of p53 increases after exposure to agents that damage
DNA.
Two main types of effects of activated p53:
a. G1 specific stop/regulation of cell cycle and allows time for DNA
repair to occur.
b. Induction of apoptosis if the damage is massive and cannot be
repaired.
In this way ot acts as the guardian of the genome or molecular
policeman.
Absence or mutations of p53 is associated with genome instability
and increases the occurrence of tumors.
Q8)List causes of hypernatremia.
1. Rapid administration of sodium salts by intravenous route.
2. Cushing disease.
3. Rapid loss of water in cases of diabetes inspidus.
4. During pregnancy due to placental hormones.
Q9 : Suggest two situations where community health education is
needed.
1. when a problem affects many or all people in the community,
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and when the cooperation of everyone is required to solve the
problem.
2. in emergencies.
3. When the problem requires pooling of resources and efforts.
Q10: Mention uses of health indicators.
They are required :
1. To measure the health status of a community.
2. To make comparisons between areas, regions and nations.
3. For assessment of health care needs.
4. For allocation of scarce (limited) resources.
5. For monitoring and evaluation of health services, activities and
program. Indicators help to measure the extent to which
objectives and targets of a problem are being attained.
Q11: Discuss in brief causes of water quality deterioration in a
community.
1. Population growth ـــ an increase in the number of people
generating waste.
2. Widespread and increasing chemical manufacture and usage of
synthetic products.
3. Gross mismanagement and irresponsible disposal of hazardous
wastes.
4. Reckless land-use practices that result in runoff of pollutants
into waterways.
