NEET MDS Shorts
812547
PathologyEpitheloid cells are a hallmark of granulomatous inflammation, which occurs in response to certain chronic infections (like tuberculosis), autoimmune diseases, and foreign body reactions. In granulomas, epitheloid cells aggregate to form a protective wall around the irritant.
406416
PathologySarcoidosis is a systemic granulomatous disorder of unknown etiology that can
affect any organ in the body. It is characterized by the formation of non-caseating
granulomas, which are clumps of inflammatory cells that cluster together in
response to an unidentified antigen. The lungs and lymph nodes are most commonly
involved. Here's a detailed explanation for each of the options:
1. Dry cough: This is a common symptom of pulmonary sarcoidosis. The cough is
usually persistent and non-productive, meaning it does not bring up mucus or
phlegm. The presence of a dry cough is not contradicted in the statement "All
are true regarding Sarcoidosis except," so this option is not the correct
answer.
2. Exertional dyspnoea: Shortness of breath on exertion can occur in individuals
with pulmonary sarcoidosis due to the inflammation and granuloma formation in
the lungs. This symptom can be a result of the impaired lung function and
decreased lung capacity caused by the disease. Therefore, this is also a true
statement regarding sarcoidosis.
3. Wheezing: Wheezing is a high-pitched whistling sound that occurs during
breathing, typically heard when airways become narrowed or blocked. It can be a
symptom of pulmonary sarcoidosis, particularly if the disease involves the
bronchi and bronchioles, leading to bronchial obstruction and airflow
limitation. However, it is not the primary symptom and may be less common than
the other respiratory symptoms mentioned.
4. Hemoptysis: While hemoptysis, or coughing up blood, is not a hallmark symptom
of sarcoidosis, it can occur in some cases, particularly when the granulomas are
located in the lungs. It is usually mild and self-limited, but severe cases can
lead to significant bleeding. This is a true statement regarding sarcoidosis, as
it is a possible, although less common, respiratory symptom of the disease.
Since all the options (1, 2, and 4) are true regarding Sarcoidosis
451930
PathologyOpsonins are molecules that enhance the phagocytosis of antigens by binding to their surfaces and acting as markers or labels that make them more recognizable to phagocytes.
1. lgG (Fc fragment): Immunoglobulin G (IgG) is the most common antibody isotype
in human serum. It plays a crucial role in the secondary immune response. The Fc
region of IgG is the fragment that interacts with Fc receptors present on the
membrane of phagocytic cells. When an antigen is coated with IgG, the Fc
fragments of these antibodies can bind to the Fc receptors, leading to the
activation of the phagocytic process. This is known as antibody-dependent
phagocytosis, where the antibody acts as an opsonin to facilitate the
recognition and engulfment of the antigen by phagocytic cells.
2. C3b of complement cascade: The complement system is a cascade of proteins
that can be activated in response to an infection or the presence of foreign
substances. C3 is a central protein in this system, and when it is cleaved into
C3a and C3b, the latter can bind directly to antigens. C3b acts as an opsonin by
coating the surface of pathogens. The presence of C3b on a microbial surface
allows it to be recognized by complement receptors on phagocytic cells, such as
macrophages. This interaction enhances the efficiency of phagocytosis, as the
receptors can recognize the bound C3b and engulf the antigen more readily.
3. IgM (Fc fragment) and C5b of complement cascade: While IgM is the first
antibody isotype produced in response to an infection and can also opsonize
antigens, it is less efficient than IgG due to its pentameric structure and
lower affinity for phagocytic receptors. However, it is not as commonly
associated with phagocytosis as IgG. Regarding C5b, it is part of the membrane
attack complex (MAC) and is involved in the direct destruction of pathogens
rather than acting as a classical opsonin that leads to phagocytosis. The MAC
assembles on the surface of the antigen and creates pores, leading to osmotic
lysis and destruction of the cell membrane.
776926
PathologyExtensive cellulitis is most accurately described by the term "phlegmon
Phlegm is a thick, viscous substance produced by the respiratory tract,
especially during a respiratory infection, which can be coughed up from the
lungs or expelled from the nose. It is primarily composed of mucus, dead cells,
and other substances.
Phlegmon is a term that is closely related to extensive cellulitis. It refers
to a severe form of cellulitis where the infection has spread deeply into the
subcutaneous tissues and is accompanied by significant inflammation, including
the presence of pus and necrosis. Phlegmon is characterized by intense pain,
swelling, redness, and warmth in the affected area. This condition often
requires aggressive medical management, including intravenous antibiotics and
surgical drainage if an abscess forms. It is an advanced and severe stage of
cellulitis that can lead to systemic infection if not treated properly.
381672
PathologySickle cell disease results from mutation, or change, of certain types of hemoglobin chains in red blood cells (the beta hemoglobin chains).
When the oxygen concentration in the blood is reduced, the red blood cell assumes the characteristic sickle shape. This causes the red blood cell to be stiff and rigid, and stops the smooth passage of the red blood cells through the narrow blood vessels.
273131
Pathology1. Noduloulcerative Basal Cell Carcinoma: This is the most common subtype of
BCC, making up about 60-70% of all cases. It typically appears as a slowly
growing, round to oval, pearly or translucent nodule with a central ulceration
that may bleed or ooze. The borders of the lesion are often not well-defined and
may have a rolled, pearly edge with telangiectasias (small, dilated blood
vessels).
2. Cystic Basal Cell Carcinoma: This subtype presents as a round, dome-shaped
lesion with a cystic or fluid-filled center. It is less common than the
noduloulcerative type, and it may be mistaken for a benign cyst or epidermoid
cyst.
3. Morphoeic Basal Cell Carcinoma: Also known as sclerosing or morpheaform BCC,
this type is characterized by a slowly growing, ill-defined, firm, plaque-like
lesion that can infiltrate deeply into the skin. It may have a whitish, waxy
appearance with a scar-like texture. Morphoeic BCC tends to be more aggressive
and can be challenging to diagnose due to its subtlety.
4. Pigmented Basal Cell Carcinoma: This is a less common variant of BCC,
accounting for approximately 6-15% of cases. It presents with pigmentation in
the lesion, which can be brown, blue, or black. The presence of pigment can make
it look similar to melanoma, another type of skin cancer, so a biopsy is often
necessary to confirm the diagnosis.
424640
PathologyCells die by one of two mechanisms – necrosis or
apoptosis
• Two physiologically different processes
– Necrosis – death by injury
– Apoptosis – death by suicide
Appoptosis:
Disintegration of cells into membrane-bound particles that are then eliminated by phagocytosis or by shedding.
139486
PathologyOncofoetal antigens are substances that are normally present in the
developing fetus but are found in abnormally high quantities in the tissues of
certain cancer cells. These antigens are proteins that can be used as markers
for the detection of certain types of cancers. The presence of these antigens in
cancer cells suggests that the tumor cells have partially reverted to a more
primitive, embryonic stage of development.
Explanation for each option:
1. á-Fetoprotein (AFP): This is an oncofoetal antigen. It is a glycoprotein that
is produced by the liver cells of the developing fetus. In adults, the
production of AFP is usually very low. However, in cases of certain cancers such
as hepatocellular carcinoma (primary liver cancer) and some types of testicular
cancer, the tumor cells start producing AFP in large amounts. Therefore, high
levels of AFP in the blood can be indicative of these cancers.
2. Carcinoembryonic antigen (CEA): CEA is another example of an oncofoetal
antigen. It is a glycoprotein that is present in the gastrointestinal tract,
pancreas, and sometimes in the respiratory and reproductive systems of a
developing fetus. In adults, CEA levels are typically very low. However, in
certain types of cancers, such as colorectal cancer, gastric cancer, and some
forms of lung, pancreatic, and breast cancer, the tumor cells may start
producing large amounts of CEA, which can be detected in the blood and used as a
tumor marker for these malignancies.
3. A and B: Both α-fetoprotein and carcinoembryonic antigen are examples of
oncofoetal antigens, so this option is correct.