Block 19 Flashcards
Celiac disease
Presentation
Diagnosis
Biopsy results
Presents between ages of 6-24 months after introduction of gluten into diet and with symptoms of malabsorption.
- other manifestation include delayed puberty and short stature in children and anemia in adults.
- screening is with serology testing for elevated IgA anti endomysial and anti tissue transglumainase and confirmed by biopsy (villous atrophy, crypt hyperplasia and inraepethilial lymphocytes infiltration) .
H.pylori associated antral gastritis is usually seen as
Chronic antral inflammation leads to decreased in number of somatostain producing cells —> somatostatin is a hormone that inhibits gastrin release. In its absence high gastrin levels acts to increased HCL by parietal cells —> dudenal ulcer.
Antigenic drift
Refers to point mutation in HA and NA genes that slightly alters the product protiens, allowing them to evade immune recognition and possibly increasing infectivity of the virus.
-However a changes in species to species transmission likely represent a major modification in protein structure that is better explained by RNA segment ressorment
Reassortment (antigenic shift)
When 2 distinct influenza strains attack one cell. For instance a human influenza virus and birds influenza virus , can lead to human HA and birds NA being packed in the same virion. —> this can lead to novel strain of virus which human are susceptible but have no immunologic resistance. (This phenomenon is responsible for all pandemics and epdimics of infleuenza A )
Most common cause of spontaneous intracranial hemorrhage in young adults is
AV malformation, ruptured cerebral aneurysm(its highly associated with coarctation of aorta due to high BP ) or cocaine abuse
Leukocytes extravasation(depends on)
- Margination and rolling : (E-selecting, P-selectin, glyCAM-1, CD34)
- Tight binding : (I-CAM-1, VCAM- 1)
- Transmigration: (PECAM-1)
- Margination (chemotaxis )
Hepcidin is
An APP, synthesized by the liver and act as a central regulator of iron hemostasis.
- high iron levels and inflammatory conditions increase the synthesis of hepcidin.
- hypoxia and increased erythropoiesis decreases hepcidin levels.
Locus ceruleus
Paired “pigmented” brianstem nucleus, located in the posterior rostal pons, near the lateral floor of the 4th ventricle.
- its the principal site for NE synthesis in the brain and projects virtually all parts of CNS.
- its associated with mood control, arousal , sleep-wake state and autonomic function (BP).
- patietns with bilateral pontine hemorrhage typically present with coma due to disruption of the reticular activating system. Other features usually include total paralysis with extensor posturing due to corticospinal and corticobulbar tract injury and pinpoint pupils secondary to descending symphatetic tract damage,
Histamine and orexin origin
Hypothalamus, they play important role in arousal and wakefulness.
Dynorphin found >
Its opoid peptide that modulate pain response. Its produced mostly in the periaqudutal gray, rostal ventral medulla, and dorsal horn of spinal cord.
Dopamine produced in
Ventral regmental area and substancia nigra pats compacta located in midbrain.
-major dopaminergic pathways in the brain include the mesolimbic and mesocrtical pathways.
What carpal bone is usually affected in carpal tunnel syndrome
Lunate
DNA methylation
Role in diseas
DNA methylation refers to addition of methyl groups to nucleotides residues(often adenine and cytosine) by DNA methyltransferase, an enzyme that uses S-adenosyl-methionine as the methyl group donor.
- fragile X syndrome —> increased CGG repeates —>hypermethylation of cytosine residues and FMR1 inactivation.
- cytosine methylation is also found in imprinting in which only one parental chromosome is presented (e.g parder willi syndrome , angelmansyndrome.)
Copper reducation test can detect
Presence of reducing sugar, is positive in fructokinase deficiency.
Maple syrup urine disease
- defective breakdown of branched chain amino acids (leucine, isoleucine and valine).
- mutation leads to accumulation of branched chain AA—> neurotoxicity —> seizures, irritability, lathergy and poor feeding.
- some patients may benefit from high dose “thiamine” treatment but still needs lifelong dietary restriction.
