Quiz 57 Flashcards
Acid-fast fecal oocysts in patient with AIDs
Cryptosporidium
How does cryptosporidium parvum cause diarrhea?
Direct lysis of cells of the brush border
Blistering rash with flaccid bullae and epithelial cell separation (acantholysis) is seen in what disease?
Pemphigus vulgaris
Positive Nikolsky sign is seen in what autoimmune blistering disease?
Pemphigus vulgaris
What are the antibodies against in pemphigus vulgaris?
Desmosomal proteins
Subepidermal, tense blisters that do not easily rupture (negative Nikolsky sign) is seen in what blistering disease?
Bullous pemphigoid
What are the antibodies directed against in bullous pemphigoid?
Hemidesmosomes
What disease has autoantibodies to desmosomes?
Pemphigus vulgaris
What organism is characterized by “box-car” large gram positive, spore forming rod?
C. Perfringens
What is the toxin associated with C. Perfringens and the myonecrosis?
Alpha toxin - lecithinase
What is the gram stain and morphology of C. Perfringens?
Gram positive rod - spore forming and anaerobic
Positive Nagler’s reaction for lecithinase is seen in what organism?
C. Perfringens
What is transplant rejection, immunologically?
Host immune system attacks the foreign tissue
What is GVHD?
Graft vs host disease - donor leukocytes consider recipient foreign and attack host tissue
What is a normal, non-pathologic form of intrinsic apoptosis?
Menstruation
Brain tumor with necrosis and hemorrhage; tumor cells are pleomorphic and frequently bizarre in appearance
GBM
What is seen histologically in GBM?
Necrosis, hemorrhage, and tumor cells that are pleomorphic with a bizarre appearance
A well differentiated variant of astrocytic tumor?
Fibrillary astrocytomas
Fried egg appearance is characteristic of what brain tumor?
Oligodendrogliomas
Nuclei surrounded by clear cytoplasm is seen in what type of brain tumor?
This is the fried egg appearance seen in oligodendrogliomas
Rosenthal fibers are a classic finding in what brain tumor?
Pilocytic astrocytoma
What patient population and where in the cranium do pilocytic astrocytomas form?
In children, usually located in the cerebellum
GBM form in what region in adults?
Cerebral cortex
Where do GBM form in children?
Brainstem
What is seen histologically in pilocytic astrocytoma?
Rosenthal fibers - “eosinophilic corkscrew fibers”
What portion of the collecting system resorbs the most water in the kidney?
Proximal convoluted tubule
What remains intact in a patient with locked in syndrome?
Vertical eye movements and blinking
What is delusional disorder?
Psychotic disorder involving one or more non-bizarre delusions in absence of other significant psychopathology
Partial glucocorticoid resistance can result in what PE and lab findings?
Increased BP, acne, hirsutism, hypokalemia, decreased renin
What is graft vascular disease?
Graft arteriosclerosis, a result from chronic transplant rejection
What can result from chronic transplant rejection?
Graft vascular disease
What is seen histologically in graft vascular disease?
Intimal and medial thickening or coronary arteries without associated atheroma formation
Patient with history of transplant dies, on autopsy there is intimal and medial thickening of the coronary arteries w/o association atheroma formation, what is the diagnosis?
Graft vascular disease
RBCs that lack the normal central pallor and concave shape
Spherocytes
What is the inheritance pattern of hereditary spherocytosis?
Autosomal dominant
What is defective in hereditary spherocytosis?
Cytoskeletal proteins - most commonly spectrin and ankyrin
Infection with what can cause red cell aplasia? Who is more likely to be affected?
Parvovirus B19; patients with pre-existing marrow disease (sickle cell anemia, HS)
What type of anemia is hereditary spherocytosis?
Normocytic and intrinsic hemolytic
How is hereditary spherocytosis diagnosed?
Osmotic fragility test
RBCs with heinz bodies and bite cells is seen in what disease?
G6PD
What disease can commonly cause hemolytic anemia in newborns?
Pyruvate kinase def.
What is the antibiotic of choice for pseudomembranous colitis?
Metronidazole
What is the mechanism of action of metronidazole?
Forms toxic free radical metabolites in the bacterial cell that damage DNA
What is an adverse effect of metronidazole?
Disulfiram-like reaction
What is seen in the labs of a patient with familial hypocalciuric hypercalcemia?
Increased serum calcium, decreased urine calcium, high levels of PTH
What is the defect in familial hypocalciuric hypercalcemia?
Defect in C coupled calcium sensing receptors
What is the genetic mutation in familial hypocalciuric hypercalcemia?
Autosomal dominant mutation of CaSR gene
Mutation in AIRE can cause what characteristic findings?
Autoimmune hypoparathyroidism; mucocutaneous candidiasis with hypocalcemia
What two arteries does CN III pass through?
Superior cerebellar artery and posterior cerebral artery
What region of the brain does the posterior cerebral artery supply?
Medial midbrain
A stroke involving the posterior cerebral artery causes what symptoms?
Contralateral hemianopia with macular sparing
Compression of CN III can cause what symptoms?
Mydriasis and inability to adduct the eye
What is the function of CN IV? What does it innervate?
Depression of the eye from the adducted position; innervates superior oblique muscles
Patient with ptosis and down and out gaze has a damage to what CN?
CN III
What muscle is responsible for abduction of the eye? What is its innervation?
Lateral rectus; supplied by CN VI (abducens n.)
Why is there an increased cardiac afterload in a patient with nocturnal hypoxia?
Increased pulmonary and vascular resistance
What is the inheritance pattern of G6PD?
X-linked recessive
What is Leber hereditary optic neuropathy?
Acute/subacute vision loss, especially in young men
What is the inheritance patter of Leber hereditary optic neuropathy?
Mitochondrial inheritance pattern
What is the inheritance of neurofibromatosis?
Autosomal dominant
What is the inheritance pattern of sickle cell anemia?
Autosomal recessive
What is the inheritance pattern on Tay-Sachs?
Autosomal recessive
Prolonged exercise (greater than a few hours) uses what metabolism to supply energy?
Hepatic gluconeogenesis
What does hepatic glycogenolysis occur in regards to exercise?
First few hours of exercise
Half life of a drug can be determined using what equation?
T 1/2 = (0.7 x Vd) / Cl
How long does it take to reach steady state?
4-5 half lives
(0.7 x volume of distribution) / clearance can be used to calculate what?
Half life
Protein extracted from cells is subjected to electrophoresis, then transferred to a filter and exposed to labeled DNA. This describes what type of technique?
Southwestern blotting
What is southwestern blotting used for?
Can be used to identify transcription factors
What interactions are involved in a Southwestern blot?
DNA-protein interactions
What technique is helpful in determining which tissues express the gene for a specific protein?
Northern blotting
What technique can be used to compare DNA samples for genetic relatedness?
Southern blot
What symptoms are seen in a patient on PCP?
Reckless behavior, horizontal or vertical (mostly) nystagmus, hypertension, tachycardia, diaphoresis
What is a Marcus-Gunn pupil?
An afferent pupillary defect - Decreased sensitivity of the affected eye to light
How can a Marcus-Gunn pupil be diagnosed?
Swinging light test
What will you see in a Marcus-Gunn pupil upon the swinging flashlight test?
Stimulation of the unaffected eye leads to pupillary constriction in both eyes, stimulation of affected eye can lead to relative dilation of both eyes
What type of T cells cause the development of IgE antibodies?
Th2
What is responsible for isotype switching to IgE?
Th2 secretion of IL-4
What cytokine is important in isotype switching to IgA?
IL-5
Amyotrophic lateral sclerosis results in degeneration of what?
UMN and LMN
Patient with UMN signs and LMN signs, what is on the top of your DDx?
ALS
In ALS, what regions of the spinal cord are affected?
Corticospinal tract (UMN) and ventral anterior horn (LMN)
Are fasciculations seen in LMN lesions or UMN lesions?
LMN lesions
Damage to the caudate nucleus is seen in what disease?
Huntington disease
What is damaged in Parkinson disease?
Substantia nigra
What is seen on a EEG during an absence seizure?
3-Hz spike and wave complex
Dynein does what in nerves?
Retrograde transport ( toward minus end)
Chlamydophila pneumoniae, Legionella pneumophila, and Mycoplasma pneumoniae have what in common?
Cause atypical or walking pneumonia and do not gram stain
What is the gram stain and morphology of H. Influenzae?
Gram negative coccobacilli
What is required for growth of Legionella pneumophila?
Charcoal yeast extrac medium with iron and cysteine
What is the gram stain and morphology of Moraxella catarrhalis?
Gram negative diplococcus
What is a key genetic marker of neuroblastoma?
Amplification of N-myc oncogene (poorer prognosis)
What is opsoclonus-myoclonus?
Opsoclonus - rapid, involuntary horizontal and vertical conjugate fast eye movements; myclonus - brief, involuntary twitching of muscles
In a patient with a neuroblastoma, what is elevated in the serum and urine?
Homovanillic acid and VMA
Young child with abdominal mass that crosses the midline, uncontrolled movement on lower limbs and eyes?
Neuroblastoma
What is the most common cause of GI obstruction in children 3 months to 6 years?
Intussusception
6 month old male presents with sudden onset of vomiting with reddish and gelatinous stool, what is the most likely underlying condition?
Intussusception
What is the mechanism of action of lactulose in the treatment of hepatic encephalopathy?
Degraded by gut flora to lactic acid, which acidifies the gut lumen. Acidification of the gut lumen favors conversion of NH3 (ammonia) to NH4 (ammonium) - NH4 cannot cross intestinal lumen
What are two other important treatments in hepatic encephalopathy besides lactulose?
Low protein diet and rifaximin (kills intestinal bacteria)
What is the drug classification of hydroxyzine?
First generation H1 antihistamine
Name 4 second generation H1 receptor antagonists
Fexofenadine, cetirizine, loratadine, desloratadine
What regions of the brain are most commonly affected by kernicterus?
Basal ganglia and brainstem nuclei involved in oculomotor and auditory function
Child with opisthotonos, high pitched cry, and abnormal Moro reflex is seen in what disease?
Kernicterus
What is a common antibiotic that can cause of kernicterus in newborns?
Sulfonamide antibiotics
During what stage of pregnancy should sulfonamide antibiotics be avoided? Why?
2nd and 3rd trimester; can cause kernicterus in newborns
What antibiotic is associated with gray baby syndrome?
Chloramphenicol
What is the MOA of chloramphenicol?
Blocks peptidyltransferase at 50S ribosomal subunit
What is the acronym for metabolic acidosis?
MUDPILES
What does the acronym MUDPILES stand for?
Methanol, uremia, DKA, propylene glycol (paraldehyde, paracetamol, phenformin), iron/isoniazid, lactic acidosis, ethylene glycol, salicylates (late)
What is seen in the urine of a patient with ethylene glycol poisoning?
Oxalate crystals - calcium oxalate
What enzyme metabolizes ethylene glycol?
Alcohol dehydrogenase
What can be used as an antidote to ethylene glycol poisoning? Why?
Fomepizole - inhibits alcohol dehydrogenase
What acid/base pathophysiology is seen with severe aspirin poisoning?
Early-primary respiratory alkalosis (stimulates resp drive); Late-metabolic acidosis (due to ASA metabolites
What nerve pierces the coracobrachialis?
Musculocutaneous
What nerve pierces the pronator teres?
Median
What nerve pierces the supinator?
Radial
What nerve pierces the flexor carpi ulnaris?
Ulnar nerve
What muscle does the median nerve pierce?
Pronator teres
What muscle does the musculocutaneous nerve pierce?
Coracobrachialis
What nerve, artery and vein exit the greater sciatic foramen above the piriformis?
The superior gluteal nav
What does the superior gluteal nerve innervate?
Gluteus medius and gluteus minimus
What is the function of the gluteus medius and gluteus minimus?
Major abductors at the hip
What is the function of the gluteus maximus?
Extensor and lateral rotator of the hip
What innervates the gluteus maximus?
Inferior gluteal nerve
Eosinophilic cytoplasmic inclusions seen in alcoholic liver disease
Mallory bodies
What are Russell bodies?
Cytoplasmic inclusions of antibody in plasma cells
