Uworld18 Flashcards
Urge incontinence can be treated with neuromodulation directed toward which nerve roots?
Directed toward the S2-4 nerve roots, which improves pelvic floor muscle strength and contraction of the external urethral sphincter; it may also impact the bladder stretch contraction reflex
By age 3, a child is expected to?
ride a tricycle, play with others, and speak in simple sentences.
Fine motor milestones for this age include ability to copy a circle, help dress oneself, and use utensils
What is thrombotic thrombocytopenia purpura?
classically presents with the pentad of severe thrombocytopenia, microangiopathic hemolytic anemia (eg, schistocytes on peripheral smear), renal insufficiency, neurologic symptoms, and fever. however, all these signs and symptoms are rarely present.
Diagnosis is often made by identifying severe deficiency of ADAMTS-13, a protease that cleaves large von Willebrand factor multimers off the endothelium
Function of vitamin K
Vit K is necessary for carboxylation of coagulation factors II, VII, IX, and X.
Newborns who do not receive prophylactic supplementation are at risk for life threatening bleeding (eg, intracranial hemorrhage)
Patient with cystic fibrosis are also at increased risk for vitamin K def due to malabsorption of fat soluble vitamins
How does candida albicans look under the microscope?
Microscopic examination of Candida albicans, a common invasive infection in patients with neutropenia, reveals budding yeasts and pseudohyphae. It can be differentiated from other Candida species by a positive germ tube test.
What is an atrial septal defect?
Atrial septal defects cause wide, fixed splitting of S2 due to right-sided volume overload from left to right shunting.
Uncorrected defects can lead to irreversible medial hypertrophy of the pulmonary arteries with pulmonary hypertension and reversal to right to left shunting (ie, Eisenmenger syndrome)
Treatment with statins causes hepatocytes to?
increase their LDL receptor density, leading to increased uptake of circulating LDL
Excess unconjugated bilirubin in the neonatal period, often caused by increased hemolysis, can cross the blood brain barrier and deposit in?
the basal ganglia and brainstem nuclei. If inadequately treated, this can lead to chronic, irreversible neurologic dysfunction, including abnormal movements (eg, chorea, dystonia) and impaired vision and hearing.
What is seen on neuroimaging for Huntington disease?
Huntington disease is an AD neurodegenerative disorder that manifests with chorea (involuntary, jerky, fidgety movements) and behavioral abnormalities (aggressiveness, depression).
Neuroimaging: atrophy of the caudate nuclei which results in enlargement of the frontal horns of the lateral ventricles
Cardiovascular dysphagia can result from external compression of the esophagus by?
a dilated and posteriorly displaced left atrium in patients with rheumatic heart disease and mitral stenosis/regurg
Formation of uric acid kidney stones is promoted by?
low urine pH, which favors formation of insoluble uric acid over soluble urate ion.
Gastrointestinal bicarbonate loss due to chronic diarrhea leads to chronic metabolic acidosis and production of acidic urine, promoting formation of uric acid stones
What is myotonic dystrophy type 1?
due to a cytosine-thymine-guanine trinucleotide repeat expansion in the dystrophia myotonica protein kinase (DMPK) gene, resulting in untranslateable mutant mRNAs.
The mutant mRNAs form hairpin structures and accumulate in the nucleus, sequestering certain RNA binding proteins and leading to aberrant splicing.
Nondividing cells of the brain, skeletal muscles, and myocardium are particularly affected.
Why does ACE inhibitors cause angioedema?
Angioedema is a rare and serious AE of ACE inhibitor therapy.
ACE inhibition increases bradykinin levels, which increase vascular permeability and lead to angioedema.
Symptoms include tongue, lips, or eyelid swelling and less frequently laryngeal edema and difficulty breathing. ACE inhibitors should be discontinued in affected patients.
Traits of campylobacter jejuni?
oxidase positive, G-, curved rod that is a leading cause of gastroenteritis.
A zoonotic organism most commonly contracted by consuming contaminated, undercooked poultry. The infection is marked by fever, abdominal pain, and diarrhea that may be bloody
Function of duodenal S-cells?
Duodenal S-cells secrete secretin in response to increasing H+ concentrations.
Secretin increases pancreatic bicarbonate secretion.
The chloride content of pancreatic secretions decreases in proportion to bicarbonate concentration increases.
Fibrate meds (fenofibrate, gemfibrozil) inhibit?
cholesterol 7a-hydroxylase, which catalyzes the rate limiting step in the synthesis of bile acids.
The reduced bile acid production results in decreased cholesterol solubility in bile and favors the formation of cholesterol gallstones
What is the first step in the classic adenoma to carcinoma sequence?
Mutation of the APC tumor suppressor gene; it is found in most cases of sporadic colon cancer and in all patients with familial adenomatous polyposis.
The microsatellite instability pathway is characterized by mutations in DNA mismatch repair genes and is implicated in the development of hereditary nonpolyposis colorectal cancer (Lynch syndrome)
What is Meniere disease?
episodic vertigo, sensorineural hearing loss, and tinnitus with aural fullness.
Its pathogenesis is related to an increased volume and pressure of endolymph in the vestibular apparatus
How to calculate risk?
Risk is the probability of developing a disease over a certain period of time.
Divide the number of affected subjects by the total number of subjects in the corresponding exposure group
What is a cross-sectional study?
In a cross sectional study, exposure and outcome are measured simultaneously at a particular point in time (“snapshot study”). In other study designs, a certain time period separates the exposure from the outcome
Diastolic blood pressure is largely determined by?
systemic vascular resistanceP
pulse pressure is largely determined by?
stroke volume
What occurs during aerobic exercise on blood pressure?
During aerobic exercise, reduced SVR leads to slightly decreased or unchanged DBP, and increased stroke volume leads to increased pulse pressure and systolic blood pressure
What is seen in a positive Trendelenburg sign?
Superior gluteal nerve injury results in weakness and paralysis of the gluteus medius, gluteus minimus, and tensor fasciae latae muscles.
This causes the pelvis to tilt downward toward the contralateral side (positive Trendelenburg sign).
Patients will also lean toward the ipsilateral side when walking to help stabilize the pelvis (gluteus medius gait)
Formula for half life
half life is a measure of how quickly a drug with first order kinetics is eliminated from the body.
A drug is almost completely eliminated after 5 half life intervals.
The half life can be calculated from the drug’s volume of distribution (Vd) and clearance rate (CL): t1/2= (0.7 x Vd)/CL
What can predispose patients to Giardia?
Giardia lamblia causes injury to the duodenal and jejunal mucosa by adhering to the intestinal brush border and releasing molecules that induce a mucosal inflammatory response.
Secretory IgA, which impairs adherence, is the major component of adaptive immunity against G lamblia infection. Conditions causing IgA def predispose patients to chronic giardiasis
What is the acid base for advanced chronic kidney disease?
Advanced chronic kidney disease typically involves the accumulation of unmeasured acidic compounds in the blood; therefore, anion gap metabolic acidosis with resp compensation is expected.
What is drug induced lupus?
abrupt onset lupus symptoms (fever, arthralgia, pleuritis) with positive antihistone antibodies.
It has been linked to drugs metabolized by N-acetylation in the liver (eg, procainamide, hydralazine, isoniazid). Genetically predisposed indivudals with slow acetylator phenotype are at greater risk for DILE.
Postoperative hypoparathyroidism with resultant hypocalcemia is a common complication of thyroidectomy due to inadvertent injury or removal of the parathyroid glands. What can be given postoperative supplementation?
oral calcium and vitamin D (calcitriol)
What is preeclampsia?
new onset hypertension at >20 weeks gestation plus proteinuria and/or signs of end organ damage.
Caused by widespread maternal endothelial cell damage due to release of antiangiogenic factors from an ischemic placenta. The result is widespread capillary leakage (proteinuria, edema) and vasospasm (hypertension, end organ hypoperfusion (eg renal failure)
MOA of nitrates
Nitrates are primarily venodilators and increase peripheral venous capacitance, thereby reducing cardiac preload and left ventricular end-diastolic volume and pressure.
At high doses, nitrates also cause some degree of arteriolar dilation with a resulting decrease in systemic vascular resistance
What cells cannot utilize ketones for energy?
When glycogen stores are depleted during fasting, ketone bodies are produced in the liver and can be used as an energy source in the mitochondria of peripheral tissues.
The brain prefers glucose, but will use ketones for most of its energy needs during prolonged starvation.
Erythrocytes lack mitochondria and are unable to use ketones.
What can be given to protect from nuclear accidents involving iodine 131?
Potassium iodide competitively inhibits thyroid uptake of radioactive iodine isotopes and is often given after nuclear accidents to protect the thyroid and prevent development of radiation-induced thyroid carcinoma
What is a complication of thiamine deficiency?
Thiamine is a cofactor for several enzymes involved in glucose metabolism. A complication of thiamine def is Wernicke encephalopathy (encephalopathy, ataxia, oculomotor dysfunction), which can be precipitated by a high glucose load causing rapid depletion of limited thiamine stores.
What causes walking pneumonia?
Mycoplasma pneumoniae is the causative agent of walking pneumonia, an infection typically characterized by a nagging nonproductive cough, low grade fever, and malaise. Often, the chest xray suggests a severe pneumonia even though the patient appears relatively well.
Mycoplasma species require cholesterol supplementation to grow on artificial media.
Function of prostacyclin (prostaglandin I2)
It is synthesized from prostaglandin H2 by prostaclycin synthase in vascular endothelial cells.
Once secreted, it inhibits platelet aggregation and causes vasodilation to oppose the functions of thromboxane A2 and help maintain vascular homeostasis.
what is systemic sclerosis? histo?
Systemic sclerosis is an autoimmune characterized by the widespread fibrosis of multiple organ systems.
Histo: expansion of the dermal layer with diffuse collagen deposition and atrophy of the intradermal adipose tissue and dermal appendages.
Pulmonary complications are common (eg, interstitial lung disease, pulmonary hypertension)
Location sites of splicing
Splicing is performed by spliceosomes, which remove introns containing GU at the 5’ splice site and AG at the 3’ splice site.
Splice site mutations may result in inappropriate removal of exons and retention of introns, leading to the formation of dysfunctional proteins.
What is a choriocarcinoma?
a malignant form of gestational trophoblastic disease composed of anaplastic cytotrophoblasts and syncytiotrophoblasts without villi.
It often presents as dyspnea/hemoptysis due to pulmonary metastasis from hematogenous spread.
What is the role of osteoprotegerin?
The receptor activator of nuclear fator kappa B (RANK/RANK ligand) interaction is essential for the formation and differentiation of osteoclasts.
Osteoprotegerin blocks binding of RANK-L to RANK and reduces formation of mature osteoclasts.
Low estrogen states cause osteoporosis by decreasing osteoprotegerin production, increasing RANK-L production, and increasing RANK expression in osteoclast precursors.
