U World Questions Flashcards
Blotchy red muscle fibers on Gomori stain are characteristic of
Mitochondrial myopathies
Abnormal mitochondria accumulate under the sarcolemma of muscle fibers –> fibers have an irregular shape and size on cross-section
Delayed separation of the umbilical cord;
recurrent cutaneous infections without pus formation;
poor wound healing;
dx?
defect in CD18 - Leukocyte adhesion deficiency
HTN classes that reduce mortality in patients with HF
ACE inhibitors
ARBs
Prevent cardiac remodeling
Common causes for Candida vaginitis (5)
Antibiotic use high estrogen levels ie during pregnancy systemic corticosteroid therapy uncontrolled DM immunosuppression ie HIV
What vascular beds develop the highest burden of atherosclerosis?
lower abdominal aorta
coronary arteries
Excess phenylalanine inhibits:
tyrosinase, required for the downstream production of melanin;
lack of melanin - fair complexion seen in PKU (deficiency of phenylalanine hydroxylase)
Intellectual disability by 6 months;
Seizures
Eczema
Light skin/hair
PKU (also musty body odor)
inability to convert phenylalanine to tyrosine
tx with tyrosine in diet, restrict phenylalanine in diet
Name the branched chain amino acids:
Leucine
Isoleucine
Valine
elevated in MSUD - deficiency of branched-chain alpha-ketoacid dehydrogenase complex
Feeding difficulties Seizures Cerebral edema Sweet odor of urine Dx?
MSUD
The C5-C6 spinal nerves mediate what reflexes?
Biceps and brachioradialis (elbow)
C4 Myotome
Shoulder/scapula elevation
C5 myotome
Shoulder ABduction
C5-C6 myotome
elbow flexion
wrist extension
C7 myotome
elbow extension
finger extension
C8 myotome
wrist flexion
finger flexion
T1 myotome
finger ABduction
C7-C8 reflexes
triceps reflex
SIADH drug causes:
Carbamazepine
SSRIs
Cyclophosphamide
Vasopressin and oxytocin are synthesized within the neurons found in what nuclei?
Paraventricular and supraoptic nuclei;
Neurophysins are involved in the posttranslational processing and stabilization of oxytocin and vasopressin within the neurosecretory vesicles during transport to the posterior pituitary
The internal iliac vein (lower rectum) drains to
the caval system
The superior rectal vein (upper rectum) drains to
the portal system
The venous component of internal hemorrhoids drains into:
the middle and superior rectal veins, which communicate with the internal iliac and inferior mesenteric veins
The venous component of external hemorrhoids drains to:
External hemorrhoids drain via the inferior rectal vein into the internal pudendal vein, which communicates with the internal iliac veins
Bacterial mRNA can be polycistronic, meaning:
that one mRNA codes for several proteins. Example = lac operon in E. Coli - the transcription and translation of the bacterial proteins is regulated by a single promoter, operator, and set of regulatory proteins;
Eukaryotic mRNA is rarely polycistronic
Effect of 2,3 BPG
decreases hemoglobin’s affinity for oxygen;
in the presence of lower blood oxygen concentrations, higher 2,3-BPG enable O2 delivery in the peripheral tissues
How is 2,3-BPG produced?
Glycolysis pathway
Glucose –> Glucose 6P –> Fructose 6P –> Fructose 1,6P –> Glyceraldehyde 3P –> 1,3 BPG
Instead of continuing in glycolysis, 1,3 BPG –(mutase in RBCs) –> 2,3 BPG
2,3 BPG can also return to the glycolysis pathway –(phosphatase)–> 3-phosphoglycerate –> 2-phosphoglycerate –> phosphoenolpyruvate –> pyruvate
What intermediate step in glycolysis produces ATP?
1,3-BPG –(phosphoglycerate kinase)–> 3-phosphoglycerate
Satiety center in the brain
Ventromedial nucleus of the hypothalamus
Where do ependymomas arise?
walls of the ventricles
can hamper CSF flow and cause hydrocephalus;
cells for gland-like structures called “rosettes”
Where are medulloblastomas found?
cerebellum, often at the vermis;
sheets of small, blue cells;
poorly differentiated/poor prognosis
Medulloblastomas and what other kind of tumor are found in the cerebellum?
Pilocytic astrocytoma - most common brain tumor in childhood;
contain pilocytic astrocytes and rosenthal fibers
Indapamide
Class and MOA
Thiazide diuretic
Blocks Na/Cl symporters in the distal tubules
can cause hypokalemia
K+ sparing diuretics (3)
Amiloride
Triamterene
Spironolactone
Block the epithelial sodium channel or aldosterone receptor
How can beta-blockers cause hyperkalemia?
Interfere with beta-2-mediated intracellular potassium uptake
How can ACE inhibitors cause hyperkalemia?
Inhibition of angiotensin II formation with subsequent decrease in aldosterone secretion
How can cardiac glycosides (ie digoxin) cause hyperkalemia?
Inhibition of the Na/K pump
How can ARBs cause hyperkalemia?
Block the AT1 receptor, thus decreasing aldosterone secretion
How can NSAIDs cause hyperkalemia?
Impaired local prostaglandin synthesis reduces renin and aldosterone secretion
MOA Shiga-like toxin
Halts protein synthesis by disabling the 60s ribisomal subunit, leading to intestinal epithelial cell death and diarrhea; AB toxin (active A and binding B) encoded by a plasmid transmitted by a bacteriophage
MOA Tocilizumab
monoclonal antibody to IL-6
treatment of giant cell arteritis, for which IL-6 is an important marker of disease severity
Which Prostaglandins are pro-inflammatory, and cause bronchoconstriction?
TXA2
PGD2
PGF2alpha
Which prostaglandins are anti-inflammatory and cause bronchodilation and vasodilation?
PGI2
PGE2
What enzyme catalyzes the formation of arachadonic acid from membrane phospholipids?
Phospholipase A2 (corticosteroids inhibit)
Prolonged, untreated obstructive sleep apnea can cause:
pulmonary HTN and RHF
Sodium nitroprusside
Use
Management of acute heart failure due to severe hypertension
IV vasodilators
Right sided colon cancers are more likely to ______ while left-sided colon cancers are more likely to ______.
Right-sided colon cancers, ie ascending colon, are more likely to:
bleed, grow as large bulky masses
Left-sided colon cancers are more likely to:
infiltrate the wall of the colon, be smaller, cause obstruction
What are the protective factors against epithelial ovarian carcinoma?
oral contraceptive use;
multiparity, breastfeeding
tubal-ligation or salpingo-oophorectomy
all reduce the # of times the epithelium of the ovary has to get repaired
Warfarin inhibits
epoxide reductase, which converts vitamin K to reduced vitamin K
Failure of PT to correct with vitamin K treatment indicates:
liver disease (reflecting factor VII deficiency)
Superior sulcus tumors are aka
Pancoast tumors
lung apex
cause shoulder pain due to compression of the brachial plexus
Integrins bind to what ECM components?
Fibronectin
Collagen
Laminin
“HALT” - diseases that involve target cells
HbC disease
Asplenia
Liver disease
Thalassemia
Bleeding time is a test of
platelet function
Platelets contain (4 main things)
vWF
thromboxane A2
fibrinogen
COX
Autoaintibodies to GpIIb-IIIa
Dx?
Immune thrombocytopenic purpura (ITP)
Deficiency of metalloprotease ADAMS-TS13
Dx?
Thrombotic thrombocytopenic purpura –> microangiopathic hemolytic anemia
Hemolysis
Uremia
Thrombocytopenia
Dx?
HUS
Hemolysis Uremia Thrombocytopenia Neurologic symptoms Fever
Thrombotic thrombocytopenic purpura –> microangiopathic hemolytic anemia
“Nasty Fever Torched His Kidneys”
How is von WIllebrand disease a mixed platelet and coagulation disorder?
vWF is needed to stabilize factor VIII;
also binds GpIb to subendothelial collagen
Tx: DDAVP (desmopressin) - forces release of vWF from storage cells
“STOP Making Thrombi” - causes of DIC
Sepsis Trauma OB complications Pancreatitis Malignancy Transfusion
Clopidogrel
Ticlopidine
Ticagrelor
Prasugrel
ADP receptor inhibitors
ADP binds ADP receptor –> induces GpIIb-IIIa on the surface of platelets
Abciximab
Tirofiban
Eptifibatide
Direct GpIIb-IIIa inhibitors;
use in NON-ST elevation MI
Maximum life span of platelet
8-10 days
NSAIDs inhibit
Thromboxane A2
MOA Enoxaparin
LMWH - inhibits factor Xa
