High Yields Week 4 Flashcards
What are the three phases of disease progression in Lyme disease (Borrelia burgdorferi infection)?
- Early phase - flu-like symptoms and erythema chronicum migrans (target looking rash)
- Early disseminated phase - CNS involvement (facial palsy) and/or cardiac involvement (AB nodal block)
- Late Lyme disease - asymmetric arthritis (typically a single knee joint) and/or encephalopathy with memory/mood changes
What are common side effects of nondihydropyridine calcium channel blockers (diltiazem, verapamil)?
Constipation
Bradycardia
AV conduction block (↓ chronotropic effect)
Worsening of HF in patients with reduced left ventricular systolic function (↓ inotropic effect)
What are the highlights of the three phases of syphilis (Treponema pallidum infection)?
Primary (3-5 wks) - painless chancre on genitals
Secondary (5-10 wks) - Diffuse macular rash that includes palms and soles, condylomata (gray wartlike lesions in genital/perianal area)
Tertiary (years later) - Gummas (white-gray rubbery lesion), ascending aortic aneurysm (vasa vasorum destruction), Argyll Robertson pupil (constricts w/ accommodation but not reactive to light)
Neurosyphilis (tabes dorsalis, “general paresis) can occur at ANY stage, but most common in tertiary
What is McCune-Albright syndrome?
Characterized by a triad of:
- fibrous dysplasia of the bone (bony abnormalities, scar tissue in bone)
- endocrine abnormalities (such as hyperthyroidism)
- cafe-au-lait spots
- precocious puberty in girls
Results from a mosaic G-protein signaling mutation causing constituitive activation of the G-protein/cAMP/adenylate cyclase signaling pathway
What is the mechanism of action of SSRIs?
Inhibition of serotonin reuptake into the presynaptic neuron, increasing the amount of serotonin in the synaptic space
This is done by blocking the “serotonin transporter”
A 45 y/o homeless man with a history of alcohol abuse presents to the ER with decreased urine output (oliguria), flank pain, metabolic acidosis and multiple calcium oxalate crystals in the urine. Disease/Dx?
Ethylene glycol ingestion
Causes metabolic acidosis, kidney stones and acute tubular necrosis (glycolic acid metabolite of ethylene glycol is toxic to renal tubules)
What is the most common type of thyroid cancer?
Papillary thyroid cancer
On histology - psammoma bodies, nuclear grooves and “Orphan Annie”
What is the inheritance pattern of MEN syndromes?
Autosomal dominant
“All MEN are dominant”
What is classically seen in MEN1?
3 P’s
Parathyroid tumors (↑ PTH → hypercalcemia Pituitary tumors (prolactin, visual/mass effects) Pancreatic endocrine tumors (usually gastrinomas → Zollinger-Ellison syndrome)
What is classically seen in MEN2A?
2 P’s
Medullary thyroid cancer (calcitonin)
Pheochromocytoma
Parathyroid hyperplasia
What is classically seen in MEN2B?
1 P
Medullary thyroid cancer (calcitonin)
Pheochromocytoma
Mucosal neuromas (skin colored lesions on lips/tongue)
Marfanoid habitus (long arms, long fingers, tall)
A 34 yo man presents with blue-black spots in his sclera and around his ears. He states that his urine turned black overnight after he forgot to flush the toilet. Disease/Dx?
Alkaptonuria
Autosomal recessive with deficient homogenistic acid dehydrogenase
This blocks the metabolism of tyrosine and causes an accumulation of homogenistic acid which is responsible for blue-black pigmentation discolorations
A 55 yo man presents with complaints of difficulty getting up from chairs and climbing stairs, diplopia, dry mouth and impotence. On physical exam he has decreased deep tendon reflexes. Chest x-ray notable for an irregular round mass in the upper lobe of his right lung. Disease/Dx?
Lambert-Eaton myasthenic syndrome secondary to small-cell carcinoma of the lung (classic association)
Lamert-Easton myasthenic syndrome is due to autoantibodies against the Ca2+ channels in the presynaptic terminal membrane that participate in acetylcholine release
Causes
- proximal muscle weakness
- cranial nerve involvement (diplopia, dysphagia)
- autonomic dysfunction (dry mouth, impotence)
In the presence of ADH, where is the most concentrated fluid in the nephron? the most dilute fluid in the nephron?
Most concentrated → Collecting ducts (ADH mediates water absorption here, concentrating the urine)
Most dilute → thick ascending limb of Henle and distal convoluted tubule (impermeable to water with lots of electrolyte reabsorption, diluting the urine)
Where is airway resistance highest in the lungs?
The first 10 generations bronchi (small/medium bronchi)
This is due to all the turbulent airflow in these regions
As a class of drugs, what is the most common adverse effect associated with atypical (2nd generation) antipsychotics?
Metabolic adverse effects
- WEIGHT GAIN
- dyslipidemia
- hyperglycemia
- increased risk of diabetes
What main veins do the right and left ovarian veins drain into?
Right ovarian vein → IVC
Left ovarian vein → left renal vein (then draining to IVC)
This mimics the testicular veins
What causes the green discoloration seen in pus or coughed up sputum during common bacterial infections (such as Strep pneumo)?
The presence of myeloperoxidase
Myeloperoxidase is a blue-green enzyme released from neutrophils during an infection
What drug should be administered for acute exacerbations of COPD or asthma?
Beta-adrenergic agonists
B2-mediated relaxation of smooth muscle causes bronchodilation, opening the airways and providing relief of obstructive lung disease
Pancreatic beta cells contain adrenergic receptors a2 and B2. What are the effects of stimulation of these receptors on the pancreatic beta cells?
a2 stimulation → inhibits insulin secretion
B2 stimulation → promotes insulin secretion
What is the most common cause of death in tricyclic antidepressant (amitriptyline) overdose?
Cardiac arrhythmias and refractory hypotension
(due to inhibition of fast sodium channels in cardiac myocytes)
Treatment of TCA overdose is NaHCO3 (sodium bicarb)
What does the presence of Howell-Jolly bodies suggest?
Decreased or absent splenic function
Howell-Jolly bodies are RBCs that DNA remnant inclusions that are normally removed by the spleen during circulation
What do the RBCs of a patient with lead poisoning look like on a peripheral blood smear? on bone marrow aspirate?
Peripheral blood smear - RBCs with basophilic stippling (due to RNA aggregation)
Bone marrow aspirate - RBCs with ring sideroblasts (due to iron deposition)
What is the most common type of cancer in people chronically exposed to asbestos?
Lung cancer (bronchogenic carcinoma) is most common
Mesothelioma (pleural cancer) is second most common
Lung cancer > Mesothelioma