Cell cycle 7-21 Flashcards
Learning
Griseofulvin is an antifungal agent that binds to ?
α/β-tubulin dimers and disrupts the spindle apparatus, preventing successful anaphase during mitosis.
The patient is 2-year-old and her father reports that she has become clumsy in recent weeks, running into furniture and hitting her head on door frames. The fundoscopy image in this case shows an amelanotic large endophytic mass in the inferior pole of the retina of the right eye, which is most consistent with ?
retinoblastoma. As opposed to the normal red reflex, this patient would be expected to have the characteristic white pupil (leukocoria) seen in children with retinoblastoma.
A mutation in the WT1 tumor-suppressor gene on chromosome 11 leads to ?
Wilms tumor of the kidney in children
Two pieces of information are critical here: first, β-tubulin is part of the microtubule structure, and second, microtubules form the mitotic spindle. Thus, ?
mitosis, or the M phase, is most affected by the posited drug in the vignette.
The patient’s presentation of orthopnea, paroxysmal nocturnal dyspnea, and peripheral edema are highly suggestive of ?
- His recent symptoms, including nausea, vomiting, and visual changes, are likely related to?
congestive heart failure
- digoxin toxicity. Digoxin (although not first-line therapy) is one treatment option for CHF, and it works by increasing contractility and thus cardiac function.
Digoxin inhibits the Na+/K+ pump, which typically extrudes three Na+ for every two K+ brought into the cell during depolarization. Because the pump is inhibited,?
the intracellular concentration of Na+ increases. The increase in intracellular Na+ inhibits the activity of the Na+/Ca2+ pump, which in turn increases the intracellular Ca2+ concentration. The increase in Ca2+ causes the increase in contractility.
Side effects of digoxin include vomiting, diarrhea, ?
vision changes including yellow halos, and arrhythmias secondary to hyperkalemia.
This patient has a tall, slender physique and a family history of a father who died at age 53 from an aortic dissection. Her appearance and family history suggest?
2. Other findings that would be suggestive of Marfan syndrome include arachnodactyly (long and slender fingers, shown in the image) and ocular lens dislocation. Marfan syndrome is associated with a high prevalence of ?
Marfan syndrome.
2. mitral valve prolapse (MVP), which can be heard in the audio clip
MVP is classically described as a midsystolic click followed by a crescendo-decrescendo murmur heard best at the apex. Maneuvers that decrease venous return (eg, Valsalva maneuver, standing) and ?
volume of the left ventricle worsen the prolapse
A ruptured aortic aneurysm in a man of this patient’s age suggests the presence of an underlying disorder. Aortic aneurysms (both abdominal and thoracic) can be sequelae of?
2. The most common type of EDS is the hypermobility type, which is not associated with a known single collagen-type deficiency. However, a defect in the synthesis of ?
Ehlers-Danlos syndrome (EDS), a group of genetic disorders characterized by joint hypermobility, skin hyperelasticity, joint laxity, easy bruising, and tissue weakness.
2. type III collagen is the most frequently seen defect in the vascular type of EDS, as seen in this patient. In the vascular form of EDS, skin hyperelasticity is less prominent. Instead, patients often exhibit thin or transparent skin and increased varicosity.
This patient presents with jaw claudication, optic nerve ischemia, decreased peripheral pulses, and an elevated ESR. Taken together, these findings suggest a diagnosis of?
2. the artery most commonly affected in patients with GCA is ? .
giant cell (temporal) arteritis (GCA), the most common systemic vasculitis in adults.
- The superficial temporal artery. On biopsy, affected arteries are characterized by nodular thickening that reduces the size of the lumen, granulomatous inflammation with mononuclear and giant cells, and fragmentation of the internal elastic membrane
This patient presents with a history of joint hyperflexibility and symptoms of hypotension, tachycardia, pulsus paradoxus, and jugular venous distention. This presentation suggests he most likely has ?
- Cardiac tamponade often manifests with the Beck triad: hypotension, increased jugular venous pressure, and distant heart sounds. On an electrocardigram (ECG), the blood surrounding the heart can attenuate the recorded electrical signal. The ECG will show ?
Marfan syndrome. He is currently experiencing an aortic dissection that has led to cardiac tamponade. Cardiac tamponade is the result of fluid (often blood) accumulating in the potential space between the visceral and parietal pericardium.
- diffuse low-voltage QRS complexes and electrical alternans
Patients with EDS have ?
- Vascular EDS is a less common and more severe form of EDS and is caused by?
hyperextensible skin, hypermobile joints, (like that evidenced in these images) and easy bleeding manifested by excessive bruising. It also may be associated with joint dislocation, organ rupture, or berry aneurysm. EDS can exhibit autosomal dominant or recessive inheritance, and its clinical severity can vary greatly.
- defective type III collagen.
Marfan syndrome is a connective-tissue disease that causes a distinctive tall, thin body habitus. Patients with Marfan syndrome are at high risk for developing heart problems, including ?
cystic medial necrosis of the aortic root, leading to aortic dissection.
This patient with a dislocated lens associated with vision difficulties, taller than average stature, and scoliosis, shows signs and symptoms of?
Together with ectopia lentis (a displaced lens), aortic involvement is a primary hallmark of Marfan syndrome and may be manifest with dilation of the aortic root leading to aortic regurgitation that is detectable on auscultation as a?
Marfan syndrome, a connective tissue disorder.
- decrescendo diastolic murmur
