NEET MDS Shorts
909424
PathologyThe expansion of the marrow space due to increased hematopoiesis can lead to resorption of the outer cortical bone and the formation of new bone, resulting in the characteristic "crew cut" appearance on X-rays. This appearance is due to the trabecular pattern of the skull becoming more prominent as the outer layer is resorbed.
378536
PathologyFat Embolism is diagnosed by -
1. Fluffy Exudates in Retina
2. Fat Droplets in Sputum
3. Fat droplets in Urine
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.
158573
PathologyEnlargement of interendothelial junctions: This option refers to the widening of the spaces between endothelial cells, which can occur during inflammation. This enlargement allows leukocytes to pass through the endothelium more easily. This is a significant mechanism in the process of leukocyte transmigration.
495883
PathologyDebulking the tumor by surgery makes the tumor cells re-enter the cell cycle and thus become susceptible to drug therapy: This statement is the most accurate. Surgical removal of a tumor (debulking) can indeed lead to the release of tumor cells into the circulation and may also alter the tumor microenvironment. This can make residual tumor cells more susceptible to chemotherapy, as they may re-enter the cell cycle and become more actively dividing, which is when many chemotherapy agents are most effective.
979232
PathologyNuclear cytoplasmic asynchrony refers to a condition where the nucleus and
cytoplasm of a cell do not develop at the same rate. This can occur in various
forms of anemia and other pathological conditions. Here's a detailed explanation
of the concept and its relevance to the options provided:
1. Megaloblastic Anemia: Megaloblastic anemia is a type of anemia characterized
by the presence of large, immature, nucleated red blood cells (megaloblasts) in
the bone marrow and peripheral blood. This condition is primarily caused by a
deficiency in vitamin B12 or folic acid, which are essential for DNA synthesis
during cell division. The nucleus of the cells divides more slowly than the
cytoplasm, leading to an asynchronous development and the formation of large,
abnormal cells. In megaloblastic anemia, the nucleus is often large and
hyperchromatic (darkly stained), while the cytoplasm is relatively less
developed and pale. Therefore, this option is the most appropriate answer.
2. Fe Deficiency Anemia: Iron deficiency anemia is the most common type of
anemia worldwide, resulting from a lack of iron in the body. Iron is a critical
component of hemoglobin, which is responsible for carrying oxygen in red blood
cells. In this condition, the body produces smaller than normal red blood cells
(microcytic) that lack hemoglobin, leading to decreased oxygen transport. The
nucleus and cytoplasm of the erythrocytes are typically smaller than normal, and
there is no significant asynchrony in their development. Hence, this option is
not a characteristic feature of nuclear cytoplasmic asynchrony.
3. Erythroblastosis Fetalis: This is a condition that occurs when an Rh-negative
mother has an Rh-positive fetus. The mother's immune system produces antibodies
against the fetal red blood cells, leading to their destruction. This causes
anemia in the newborn. However, erythroblastosis fetalis is not typically
associated with nuclear cytoplasmic asynchrony. The anemia is a result of
hemolysis (destruction of red blood cells) rather than an intrinsic defect in
the development of the cells themselves. Thus, this option is not the correct
answer for this characteristic feature.
correct answer is:
1. Megaloblastic anemia
This is because megaloblastic anemia is the condition where nuclear cytoplasmic
asynchrony is a hallmark feature due to the disproportionate growth of the
nucleus and cytoplasm in red blood cell precursors, resulting from vitamin B12
or folic acid deficiencies affecting DNA synthesis.
135863
PathologyMcroscopic picture of red blood cells (RBCs) in thalassemia, the following
characteristics are typically observed:
Microcytic: The RBCs are smaller than normal (microcytic)
due to the reduced hemoglobin content.
Hypochromic: The RBCs have a lower concentration of
hemoglobin, leading to a paler appearance (hypochromic).
Target cells: These are RBCs that have a bullseye
appearance due to an abnormal distribution of hemoglobin within the cell.
Target cells are often seen in thalassemia due to the imbalance of globin
chains and the resultant membrane changes.
388981
Pathology
The principal chemical mediator of the immediate phase of acute inflammation
is Histamine. Here's a detailed explanation of the options given:
1. Serotonin: While serotonin is a vasoactive substance that can cause blood
vessels to constrict or dilate, it is not the primary mediator of the immediate
phase of acute inflammation. It is mainly associated with the regulation of
mood, appetite, and sleep. In the context of inflammation, it plays a minor role
compared to histamine.
2. Histamine: Histamine is indeed the correct answer. It is a potent chemical
mediator released from mast cells and basophils in response to injury or
antigenic stimulation. Upon release, histamine acts on blood vessels to cause
vasodilation, increased permeability, and increased blood flow to the injured
area, which are hallmark features of the immediate phase of acute inflammation.
This results in the cardinal signs of inflammation: redness (rubor), heat
(calor), swelling (tumor), and pain (dolor).
3. Kinin-Kallikrein system: The kinin-kallikrein system is another important
mediator of inflammation, but it is more involved in the later phases. When
activated, it results in the formation of kinins, such as bradykinin, which
contribute to increased vascular permeability and pain. However, it is not the
first line mediator in the immediate phase.
4. Complement system: The complement system is a group of proteins in the blood
that work with antibodies to destroy pathogens and trigger inflammation. It is a
key component of the innate immune response, but its activation and role are
more pronounced in the later stages of inflammation rather than the immediate
phase. The complement system is involved in the opsonization of pathogens,
recruitment of phagocytes, and the formation of the membrane attack complex,
which can lyse certain bacteria and cells.
The immediate phase of acute inflammation is characterized by the rapid response
to tissue injury, which includes vasoactive changes and increased vascular
permeability to allow fluid, cells, and proteins to move into the interstitial
space. Histamine is quickly released from mast cells and basophils and acts on
H1 receptors of blood vessels to induce vasodilation and increased permeability.
This leads to the early symptoms of inflammation, such as swelling, redness,
heat, and pain, and is crucial for the initiation of the inflammatory response
to protect the body from harm.