Adolescent with neuropathic pain (burning sensations) and hypohidrosis (decreased sweating) exacerbated by stress, exercise, and fatigue. Later he develops angiokeratomas (dark red, non-blanching macules and papules in clusters over the butt, groin, and umbilicus) and telangiectasias.
What is the diagnosis?
alpha-galactosidase A deficiency
Buildup of globotriaosylceramide
Leads to: cerebrovascular and cardiac issues, renal failure due to Gb3 buildup
How does sepsis cause ARDS?
As cytokines circulate in response to the infection, they activate the pulmonary epithelium and provoke an inflammatory response mediated by neutrophils. This leads to capillary damage and the leakage of protein and fluid into the alveolar space.
Newborn girl with normal internal genitalia but ambiguous or male-type external genitalia (clitoromegaly). Baby caused mother to be virilized (hirsutism, deep voice). What is deficient in the baby?
High androgen and low estrogen in a female fetus.
What enzyme functions exclusively in the nucleolus?
RNA Polymerase 1
Transcribes 45S pre-rRNA into a template that is processed into mature 18S, 5.8S, and 28S rRNAs.
FORMATION OF RIBOSOMES
Functions of IL-2
1. Proliferation and differentiation of Helper T cells
2. Monocyte activation
3. NK Cell activation
4. Growth of T cells and INF gamma secretion
5. Stimulation of division of B cells
*Anti-cancer effect on metastatic melanoma and renal cell carcinoma*
First line treatment for Narcolepsy (daytime) for stimulation
Rarely causes drug abuse
What is a developmental field defect?
Multiple malformations that occur secondary to an embryonic disturbance in an adjoining group of cells.
Ex = holoprosencephaly
Penicillins, cephalosporins, and vancomycin target what part of an organism?
Peptidoglycan cell wall
Most common pathogens causing nosocomial bloodstream infections
Coag neg staph
An IL-1 or TNF-alpha inducible enzyme that is highly expressed by inflammatory cells and undetectable in surrounding normal tissue....
Target it specifically with Celecoxib
An increased total RBC mass in the presence of an increased hematocrit level
Increased hematocrit with normal RBC mass
Likely due to dehydration or excessive diuresis
Absolute polycythemia with decreased Erythropoietin levels
Caused by a myeloproliferative disorder like PV
Absolute polycythemia with increased erythropoietin levels
Chronic hypoxia from high altitudes, smoking, COPD OR abnormal secretion by neoplastic or otherwise diseased tissues
Pt. with hemolytic anemia, hypercoagulability (hepatic vein thrombosis), pancytopenia
Paroxysmal nocturnal hemoglobinuria (PNH)
Absence of GPI anchor and CD55 and CD59 deficiency leads to complement-mediated hemolysis (more often at night due to lower blood pH)
What is the only prokaryotic polymerase with 5'-3' exonuclease activity?
DNA Polymerase 1
Removes the RNA primer created by RNA primase and repairs damaged DNA sequences.
In a patient with acute mesenteric ischemia, what causes the resulting acid-base disorder?
Inadequate delivery of oxygen to intestinal tissues --> hypoxic conditions --> intracellular accumulation of NADH --> inhibition of pyruvate dehydrogenase --> pyruvate is converted to lactate --> lactic acidosis
This type of cell found on a pap smear... sign of what?
HPV infection - double stranded, non-enveloped DNA virus with a predilection for squamous epithelium of skin/vagina/cervix
Leuprolide has what initial effect on hormones?
GnRH agonist that causes a transient increase in pituitary LH secretion, which leads to a rise in testosterone levels. If used continuously, it will suppress LH release and lead to a decrease in testosterone production.
High arches (pes cavus)
Hypertrophic cardiomyopathy and CHF
Spastic muscle weakness
Loss of position and vibration sensation
Mutated frataxin gene --> GAA repeats
Decreased mitochondrial energy production and increased oxidant stress -->
1. Spinocerebellar and Lateral corticospinal tract degeneration
2. Dorsal column and DRG degeneration
Enteropeptidase is responsible for activation of what? Where is it located?
Jejunal brush border enzyme
Deficiency = protein and fat malabsorption --> diarrhea, failure to thrive, edema
Lesion of the lateral optic chiasm can cause ipsilateral nasal hemianopia. An issue with what artery can cause this issue?
Aneurysm of the internal carotid (cavernous or opthalmic segments)
*uncrossed optic nerve fibers from the temporal portion of the retina*
Spontaneous deep intracerebral hemorrhage
Hypertensive vasculopathy from penetrating branches of major cerebral arteries.
Basal ganglia (putamen), cerebellar nuclei, thalamus, pons
Lenticulostriate arteries off MCA --> basal ganglia
Postpartum hemorrhage is usually due to what artery?
Internal iliac --> uterine arteries
Epithelial cells covered with gram-variable rods
Gardnerella vaginalis (bacterial vaginosis)
Metronidazole or Clindamycin
Thick cottage cheese discharge from cervix
Most characteristic skeletal abnormality of Primary Hyperparathyroidism
Osteitis Fibrosa Cystica:
Cortical (compact) bone: pelvic girdle, pectoral girdle, limbs)
Subperiosteal erosions affecting fingers
Brown tumor bone cysts in long bones
Pt presents with constipation, new-onset 2nd degree AV block, and syncope in the setting of a new medication for atrial fibrillation
Calcium channel block
Kid with poor exercise tolerance, muscle cramps, and rhabdomyolysis
Major virulence factor for Strep Pyogenes that inhibits phagocytosis and the activation of complement
Functions of Insulin
Increases peripheral glucose uptake
Inhibits ketoacid formation
Decreases glucagon release
What class of antiarrythmetics prolongs QRS duration without affecting the QT interval?
*only affect fast sodium channels*
Direct thrombin inhibitors are the DOC for treating what? Why?
Heparin-induced thrombocytopenia (HIT)
They do not require antithrombin-3 for their action because they bind directly to the thrombin active site.
Argatroban, Hirudin, Lepirudin
Which TB drug causes optic neuropathy?
Ascertaining a patient's volume status and checking urine chloride are important steps in working up what?
Crescent formation in RPGN is caused by the deposition of what?
Deposition of fibrin within Bowman's space + proliferatied glomerular parietal cells, monocytes, macrophages that have migrated into Bowman's space
What lab value should be checked before initiation of metformin?
Metformin inhibits hepatic gluconeogenesis and increases peripheral glucose utilization. Lactic acidosis is a rare complication of metformin therapy, but it's risk is increased in pts with underlying renal insufficiency.
Host cell is coinfected with 2 viral strains and progeny virions contain unchanged parental genome from 1 strain and nucleocapsid (or envelope) proteins from the other strain.
Due to the lack of change in the underlying genome, subsequent progeny will revert to having only one viras type surface protein again.
Autopsy findings of endocardial thickening and fibrosis of tricuspid and pulmonary valves are characteristic of what?
Carcinoid heart disease
Pathogenesis of carcinoid heart disease
Excessive secretion of serotonin, which stimulates fibroblast growth and fibrogenesis.
Plaque like deposits of fibrous tissue usually in endocardium, lead to tricuspid regurgitation, pulmonic valve issues, and right sided heart failure (ascites, peripheral edema)
Why is carcinoid heart disease limited to the right side of the heart?
Vasoactive products are inactivated distally by pulmonary vascular endothelial MAO
27 y/o with recurrent episodes of muscle weakness (hypokalemia), high BP, very low plasma renin
Bilateral nodular hyperplasia
Hyperfunctioning adrenal glomerulosa (mineralocorticoids) or an aldosterone-producing adrenal adenoma (Conn syndrome)
Proto-oncogenes stimulate cell proliferation, and their overexpression/amplification (activating mutation) leads to increased cellular proliferation and neoplastic growth. What are they?
RAS (KRAS, HRAS)
What are the tumor suppressor genes? Their inactivation contributes to tumor development.
Infection with systemic symptoms (fever, wt. loss), painful oral ulcers, lymphadenopathy, and hepatosplenomegaly.
Causes disseminated mycosis in immunocompromised pts.
Can survive intracellularly within macrophages.
What bug is + for PYR (pyrrolidonyl arylamidase)?
PYR is more specific than bacitracin.
8 year old with vomiting and lethargy after a period of fasting. Low glucose, SUPER high AST and ALT. Begins seizing. What is deficient?
He has hypoketotic hypoglycemia
Defect in fatty acid beta oxidation in the mitochondria.
Most common enzymatic defect leading to this is acyl-coA dehydrogenase.
This kid cannot oxidize fatty acids for energy or produce ketone bodies when fasting.
What would you treat MRSA with if a pt. is allergic to vancomycin?
Depolarizes cellular membrane by creating transmembrane channels.
It is inactivated by surfactant so it is not useful for pneumonia.
AE = Increased CPK, myopathy
Treatment of urea cycle disorders consists of what?
Balancing dietary protein intake and output, so the body receives the essential amino acids needed for growth and development but not in excess such that excessive ammonia is formed.
Pathogenesis of acute decompensated heart failure
Compensatory neurohumoral stimulation: increased sympathetic --> RAAS activation --> release of ADH
This improves CO by increasing cardiac chronotropy and iontropy, expanding the extracellular fluid compartment, and causing arterial and venous vasoconstriction.
BUT it also leads to increased afterload, excess fluid retention, and deleterious cardiac remodeling.
A parent's authority to make medical decisions for their children can be challenged in cases in which a child is at significant risk for harm. What should a Dr. do?
Obtain a court injunction to proceed with life-saving medical treatment of the child
A pt. with DiGeorge syndrome will cause what change in a lymph node?
Poor development of the LN paracortex due to an extreme deficiency in the number of mature T lymphocytes
Septic shock results from release of endotoxins. What is the source of endotoxin in Gram - bacteria?
Lipid A from LPS
It activates macrophages and granulocytes leading to the synthesis of endogenous pyrogens (IL-1, prostaglandins, TNF alpha, interferon)
The posterior part of the external auditory canal is inervated by what nerve?
Vagus (auricular branch)
Stimulation with an otoscope can cause vasovagal syncope --> parasympathetic outflow via the vagus nerve leads to decreased HR and BP
The majority of the posterior surface of the heart is what?
What lies posterior to the esophagus and can be seen with transesophageal echocardiography?
Descending thoracic aorta
Gastric varices found in the FUNDUS of the stomach are due to an issue with what vein?
Short gastric veins --> splenic vein
Most inhaled particles that lodge in the bronchial tree are removed how?
Via proximal transport of mucus by ciliated epithelial cells (mucociliary clearance)
Macrophages are used to clear particles inhaled if in what part of the lung?
Distal to the terminal bronchioles
What drugs can be used to assist in prevention of cerebral vascular spasm after a subarachnoid hemorrhage?
Calcium channel blockers (specifically Nimodipine)
IgA protease produced by Neisseria species, strep pneumo, and h. flu has what purpose?
It cleaves secretory IgA at it's hinge region, rendering it ineffective.
This allows bacteria to adhere to mucosa
Secretory IgA normally acts to bind and inhibit the action of pili as well as other cell surface antigens that normally mediate mucosal adherence and subsequent penetration.
Child with Lower-extremity claudication (cramping with exercise), blood pressure discrepancy between the upper and lower extremities, and delayed or dimished femoral pulses
Associated with Turner Syndrome (45, XO)
Myxomatous changes with pooling of proteoglycans in the media layer of large arteries are found in cystic medial degeneration, which predisposes to the development of what?
*frequently seen with Marfan Syndrome*
Concurrent use of a statin with what drugs is associated with increased incidence of statin-induced myopathy and rhabdomyolysis (and therefore acute renal failure)?
CYP 450 Inhibitors:
Maple Syrup Urine Disease
Defective breakdown of branched chain amino acids (leucine, isoleucine, and valine)
Branched-chain alpha ketoacid dehydrogenase requires 5 cofactors:
Branched chain alpha ketoacid dehydrogenase
All of these require what?
Progressively weakening diaphragmatic contractions during maximal voluntary ventilation with intact phrenic nerve stimulation indicates what?
Neuromuscular junction pathology (MG)
OR abnormally rapid diaphragmatic muscle fatigue (Restrictive lung disease or chest wall disease)
The adrenal medulla is sharply demarcated from the cortex and is composed of chromaffin cells with deeply basophilic cytoplasm. What activates the cells?
Down syndrome predisposes to what cancer?
A physiologic increase in maternal insulin resistance occurs during the 2nd and 3rd trimester due to the action of what?
Human Placental Lactogen (hPL)
Secreted by the syncytiotrophoblast
A pt. from Guatemala with no underlying immunocompromising conditions has a seizure and is found to have a cystic lesion in his brain.
Taenia Solium (pork tapeworm)
Ingestion of eggs excreted in feces of human carriers
Effects of Nitroprusside
Decreases LV preload and afterload
No change in stroke volume
Acute angle closure glaucoma treatment preference works how?
Inhibits carbonic anhydrase
Affects the PCT
Child with hepatosplenomegaly, neurologic regression, hypotonia, and a cherry-red macular spot in infancy
Accumulation of sphingomyelin
Ehler's Danlos syndrome pathogenesis
Defective collagen synthesis
Deficiency of procollagen peptidase, the enzyme that cleaves terminal propeptides from procollagen in the extracellular space.
Joint laxity, hyperextensible skin, fragilt tissues with easy bruising, poor wound healing
The anterior compartment of the leg contains what?
Deep peroneal nerve
Anterior tibial artery and veins
Empty can test is testing what muscle of the rotator cuff?
Most commonly affected muscle due to chronic repeated trauma from impingement between the head of the humerus and the acromion during abduction.
Pts. with Chronic Granulomatous Disease develop recurrent bacterial and fungal infections that are caused by what?
5 catalase-positive organisms:
Complication that happens within 5-14 days of a large anterior transmural MI
Free wall rupture --> hemopericardium and tamponade --> profound hypotension and shock
During this timeframe, the infarcted myocardium is substantially weakened by coagulative necrosis, neutrophilic and macrophage infiltration, and enzymatic lysis of myocardial connective tissue.
A 1 month old male with persistent jaundice, muscle rigidity, lethargy, and seizures. What is the most likely cause of his hyperbilirubinemia?
Absent UGT (liver conjugation enzyme) needed to catalyze bile glucuronidation.
Crigler-Najjar Type 1 (AR)
Exaggerated drop in systolic BP during inspiration
Impaired expansion into pericardial space
Most frequent causes of pulsus paradoxus in the absence of significant pericardial disease?
Drugs used for acute asthma and COPD exacerbations
Beta-adrenergic agonists --> cause bronchial smooth muscle relaxation via increased intracellular cAMP
Best treatment for generalized epilepsy
Hexagonal shaped urinary crystals
Sodium cyanide-nitroprusside test
Treat = increased hydration and urinary alkalinization (acetazolamide)
Spina bifida has what mode of inheritance?
Due to decreased amounts of bile aids and phospholipids cause the bile to become supersaturated with cholesterol.
Treat = hydrophilic bild acids will promote gallstone dissolution
Human tumor cells can resist chemotherapy via the human multidrug resistance (MDR1) gene. This makes what?
P-glycoprotein, a transmembrane protein that functions as an ATP-dependent efflux pump. This can actively remove chemo agents, particularly hydrophobic agents like the anthracyclines.
At low doses, Atenolol is selective for what?
Selective B1 adrenergic antagonist
Only works on cardiac and renal juxtaglomerular cells
NOT vascular smooth muscle
Pt. with HIV with HA, seizures, and multiple ring enhancing CNS lesions on MRI
Pigment gall stones
Calcium salts of unconjugated bilirubin
Soft, dark brown to black
Usually arise secondary to bacterial or helminthic infection of the biliary tract resulting in the release of beta-glucuronidase by injured hepatocytes and bacteria.
Beta-glucuronidase hydrolyzes bilirubin glucuronides and increases the amound of unconjugated bilirubin.