Uworld23 Flashcards
What is the first line treatment of bipolar?
The goal of bipolar maintenance treatment is to delay or prevent recurrent manic and depressive episodes.
Lithium is a first line treatment and has the added benefit of reducing the risk of suicide.
Portal hypertension in cirrhosis leads to?
vasodilation and decreased systemic perfusion pressure, which causes antidiuretic hormone release and activation of the renin-angiotensin-aldosterone system, promoting sodium and water retention.
However, due to resistance to splanchnic flow, low oncotic pressure, and hyperdynamic circulation, the fluid is third-spaced into the extravascular compartments (eg, ascites). Therefore, despite increased total body volume, patients with cirrhosis remain intravascularly volume depleted.
What is abetalipoproteinemia?
an inherited inability to synthesize apolipoprotein B, an important component of chylomicrons and very low density lipoprotein,
Lipids absorbed by the small intestine cannot be transported into the circulation and instead accumulate in the intestinal epithelium, resulting in enterocytes with clear or foamy cytoplasm.
Candida albicans is a normal commensal of what?
Expectorated sputum cultures are often contaminated by normal oral flora. The growth of Candida albicans, a normal commensal of the gastrointestinal tract and skin, almost always indicates oral contamination rather than true pulmonary infection.
What is necrotizing enterocolitis?
one of the most common gastrointestinal emergencies affecting newborns.
It is characterized by bacterial invasion and ischemic necrosis of the bowel wall, and is associated with prematurity and initiation of enteral feeding.
Abdominal xray showing pneumatosis intestinalis (ie, air in the bowel wall) confirms the diagnosis.
Which antibiotics disrupt bacterial cell wall synthesis?
The bacterial cell wall protects the organism from osmotic stress. Antibiotics that target the cell wall result in bacterial lysis in hypotonic solutions.
Fosfomycin, vancomycin, penicillins, and cephalosporins all disrupt bacterial cell wall synthesis.
hCG is structurally similar to?
Anovulatory infertility can be treated with ovulation induction therapy, which may include a course of gonadotropins to stimulate the ovarian follicles.
Once the follicles mature, patients are administered an injection of hCG, which mimics the LH surge and acts as the ovulation trigger
What age do kids understand death?
Preschool children have no developed an understanding of the finality of death, which typically occurs around age 7.
They may have magical thoughts that death is temporary or reversible and believe that other people’s grief is their fault.
Primary herpes simplex virus type 1 infection causes what in children?
gingivostomatitis (ie, vesicles on the anterior oral mucosa, particularly the lips and gingivae). HSV-1 and other herpesviruses are double stranded, enveloped DNA viruses.
Which portion of the portal circulation does esophageal varices come from?
left gastric vein
Which part of the portal circulation does anorectal varices come from?
Superior rectal vein
which part of the portal circulation does caput medusae come from?
paraumbilical veins
In patients with hemolytic anemia, peripheral blood smear usually reveals evidence of?
reticulocytosis, spherocytes, and nucleated red blood cells.
What is the major pathogenic contributor to atrial fibrillation?
Atrial remodeling is the major pathogenic contributor to atrial fibrillation.
Age and comorbidities that cause atrial dilation (eg, hypertension, heart failure, mitral valve disease) cause atrial structural changes that predispose to atrial fibrillation development. In addition, age and previous atrial fibrillation cause atrial conduction system changes that further propagate atrial fibrillation.
What is histone H1?
Nucleosomes are composed of DNA wrapped around a core of histone proteins.
Histone H1 is unique in that it is located outside this histone core and helps package nucleosomes into more compact structures, limiting transcriptional access to DNA.
Urine sediment in acute ureterolithiasis typically shows?
free red blood cells (hematuria) and crystals consistent with the type of stone.
Ultrasound can reveal ureteral and calyceal dilation (hydronephrosis), but small stones themselves may not be visible.
What is alveolar consolidation?
occurs when the alveoli become filled with fluid (eg, inflammatory exudate in bacterial pneumonia).
The increased compactness of the alveolar fluid (compared to air) causes sound to travel faster and more efficiently, resulting in bronchophony, increased tactile fremitus (vibration) and increased intensity of breath sounds over the affected area.
Dullness to percussion is also present.
Methicillin-resistance Staph aureus (MRSA) is resistant to most beta-lactam medications (eg, oxacillin, methicillin, cephalosporins) due to?
the acquistion of a mobile genetic element that contains the mecA gene. This gene encodes for a specialized penicillin-binding protein that has low affinity for beta-lactam antibiotics.
Treatment of MRSA therefore requires a non-beta lactam medication such as trimethoprim-sulfamethoxazole, clindamycin, doxycycline, or vancomycin.
What are the effects of epinephrine?
Epinephrine increases systolic blood pressure (a1 and b1) and heart rate (b1), and either increases or decreases diastolic blood pressure depending on the dose (either a1 or b2 predominates)
Pretreatment with propranolol eliminates the beta effects of epinephrine (vasodilatation and tachycardia), leaving only the alpha effect (vasoconstriction)
What is von Willebrand disease?
the most common inherited bleeding disorder.
It has an autosomal dominant pattern of inheritance and variable penetrance.
Absence of von Willebrand factor leads to impaired platelet function (prolonged bleeding time) and coagulation pathway abnormalities due to decreased factor VIII activity (prolonged partial thromboplastin time)
What is negative selection?
The process of negative selection in T cell maturation is essential for eliminating T cells that bind to self MHC or self antigens with overly high affinity.
This process occurs in the thymic medulla. If these cells are permitted to survive, they would likely induce immune and inflammatory reactions against self antigens leading to autoimmune disease
What is Sjogren syndrome?
autoimmune disorder characterized by lymphocytic inflammation in exocrine glands (eg, lacrimal, salivary). It presents with dry eyes (keratoconjunctivitis sicca) and dry mouth (xerostomia)
Chronic B cell proliferation increases the risk for non-Hodgkin lymphoma.
What is major depressive disorder with psychotic features?
a severe subtype of unipolar major depression characterized by symptoms meeting the criteria for MDD and the presence for delusions and/or hallucinations.
The splenic artery originates from which artery?
the celiac artery and gives off several branches to the stomach and pancreas (pancreatic, short gastric, and left gastroepiploic arteries) before finally reaching the spleen.
Due to poor anastomoses, the gastric tissue supplied by the short gastric arteries is vulnerable to ischemic injury following splenic artery blockage.
What are villous adenomas?
Villous adenomas tend to be larger, sessile, and more severely dysplastic than tubular adenomas.
Villous adenomas can cause a secretory diarrhea from increased mucin production; patients may develop hypoproteinemia and hypokalemia.
What is a tension pneumothorax?
involves progressively increasing intrapleural pressure that leads to contralateral mediastinal shifting (eg, tracheal deviation) and vena cava collapse.
Hypotension, tachycardiac, and obstructive shock develop due to decrease venous return to the heart.
Fluoroquinolones can form insoluble chelate complexes with?
polyvalent cations (eg, calcium, iron, aluminum, magnesium) in the GI tract, leading to impaired absorption.
This effect can be seen with over the counter antacids containing calcium, magnesium, and/or aluminum salts and in patients taking calcium salts (eg, calcium carbonate, calcium citrate) for treatment of osteoporosis.
What is the most common cause of severe, unilateral fetal hydronephrosis?
Inadequate canalization of the ureter at the ureteropelvic junction (the connection site between the kidney and the ureter)
Anemia with an elevated reticulocyte count (ie, reticulocytosis) indicates?
that the bone marrow is responding appropriately to the anemia by generating new erythrocytes.
Reticulocytosis is commonly seen in patients with hemolysis or acute bleeding.
Many other causes of anemia are associated with LOW reticulocyte count, including bone marrow suppression (eg, parvovirus), iron deficiency anemia, vitamin b12/folate def, and anemia of chronic disease.
MOA of echinocandins (capsofungin, micafungin)
antifungal medications that inhibit synthesis of the polysaccharide glucan, an essential component of the fungal cell wall.
An inappropriately small sample will fail to identify important clinically signifcant differences as statistically significant because of a lack of?
sufficient statistical power.
The probability that an autosomal recessive disease will be transmitted to a child can be calculated bases on the maternal and paternal pedigrees. An unaffected individual (with unaffected parents) who has a sibling afftected by an autosomal recessive condition has what chance of being a carrier for that condition?
2/3
What is social anxiety disorder?
excessive fear of scrutiny or embarrassment in social or performance situations, resulting in significant distress and functional impairment.
Function of the lateral pterygoid muscles
The lateral pterygoid muscles are the only muscles of mastication that aid in depressing the mandible (ie, opening the jaw).
Spasm of the lateral pterygoids prevents spontaneous reduction of an anterior dislocation of the temporomandibular joint.
Injury to which artery can cause osteonecrosis of the femoral head?
The medial circumflex femoral artery and its branches provide the majority of blood supply to the femoral head and neck.
Injury to these vessels due to a displaced femoral neck fracture can cause osteonecrosis of the femoral head.
What is acute rheumatic fever?
an autoimmune reaction following an untreated group A streptococcal pharyngitis.
Anti-group A streptococcus antibodies (eg, anti-M protein, anti-N-acetyl-beta-D-glucosamine) cross react and attack cardiac and central nervous system antigens
What is Crohn disease?
presents with insidious onset of abdominal pain, diarrhea, and constitutional symptoms (eg, weight loss, fever).
Patients are prone to developing fistulas/abscesses as the lesions affect the entire thickness of the bowel wall.
Perianal disease (skin tags, fissures) is also common.
What are the physiologic renal adaptions during pregnancy?
increased glomerular filtration rate, greater basement membrane permeability, and decreased tubular resorption of filtered protein.
As a result, trace urinary protein excretion (ie, <300 mg/24 hr) is a normal finding in pregnancy.
What is an essential tremor?
most often presents as a tremor of the hands that is suppressed at rest, exacerbated by outstretched arms, and more pronounced during goal-directed movements.
It is often hereditary (autosomal dominant) and can be associated with a head tremor, but it is not associated with other neurologic symptoms.
What is the most common cause of peripheral polyneuropathy in adults?
Diabetes mellitus; common findings include numbness and paresthesias in a stocking glove distribution and decreased proprioception due to degeneration of large-fiber sensory axons.
