NBME 7 BLOCK 1-4 (with Answers)

Skip to: NBME 7 BLOCK 1
Block 1
Block 2
Block 3
Block 4



Loading...



For number 4...This is a case of Sacrococcygeal teratoma...
Sacrococcygeal teratoma is one of the extragonadal germ cell tumors ...This is what I get
from emedicine.......These tumors can be found anywhere on the midline, particularly the
retroperitoneum, the anterior mediastinum, the sacrococcyx, and the pineal gland. Other

Loading...less common sites include the orbit, suprasellar area, palate, thyroid, submandibular region,

anterior abdominal wall, stomach, liver, vagina, and prostate. The classic theory suggests
that germ cell tumors (GCTs) in these areas are derived from local transformation of
primordial germ cells misplaced during embryogenesis...which means defect in primordial
germ cell migration ......
My answer Is EE
F ... is for sacral agenesis
D..is for spina bifida
C..is for neurocristopathies, which include conditions such as frontonasal dysplasia,
Waardenburg-Shah syndrome, and DiGeorge syndrome, ......etc
B..is clear
A...is for cranial abnormalities.....





Pyruvate carboxylase is a mitochondria enzime requiring biotin. It is activated by acetylCoA( from beta-
oxidation. The product oxaloacetate(OAA), a citric acid cycle intermediate, cannot leave the mitochondria
but is reduced to malate that can leave via a Malate shuffle. In the cytoplasm malate is reduced to (OAA).
Pyruvate carboxylase deficiency is an inherited disorder that causes lactic acid and other potentially
toxic compounds to accumulate in the blood. High levels of these substances can damage the body's
organs and tissues, particularly in the nervous system. Pyruvate carboxylase deficiency is a rare
condition, with an estimated incidence of 1 in 250,000 births worldwide. This disorder appears to be
much more common in some Algonkian Indian tribes in eastern Canada.





Loading...





































Loading...









remove the tonic inhibition exerted by GPi on the VL and VA nuclei of the thalamus





















The P value for a study should be less than 0.05.
This value means that when we perform a study, the 95% of the time the observations
are rite & 5 % of the time the observation are due to chance alone.
In this question the value of P is 0.3 which means that the probability that these
observations are due to chance alone is 30%, which is not a statistically acceptable
number





In this test, "stimulator" lymphocytes from a potential donor are first killed by irradiation
and then mixed with live "responder" lymphocytes from the recipient; the mixture is
incubated in cell culture to permit DNA synthesis, which is measured by incorporation of
tritiated thymidine. The greater the amount of DNA synthesis in the responder cells, the
more foreign are the class II MHC proteins of the donor cells. A large amount of DNA
synthesis indicates an unsatisfactory "match"; i.e., donor and recipient class II (HLA-D) MHC
proteins are not similar, and the graft is likely to be rejected. The best donor is, therefore,
the person whose cells stimulated the incorporation of the least amount of tritiated
thymidine in the recipient cells.