Uworld29 Flashcards
Late onset familial Alzheimer disease is associate with?
apoplipoprotein E4 genotype
Dysfunction of CNIII leads to?
The oculomotor nerve (CNIII) provides innervation to many of the extraocular muscles (superior rectus, medial rectus, inferior rectus, inferior oblique), parasympathetic innervation to the pupil, and somatic innervation of the levator palpebrae superioris.
Dysfunction of CN III leads to a characteristic triad of a “down and out” pupil, an efferent pupillary defect, and ptosis.
When can angiosarcomas occur?
Angiosarcomas classically occur after the treatment of breast cancer from either radiation exposure or chronic lymphedema with firm, violaceous nodules on the ipsilateral extremity.
Lack of vitamin D effect (eg, vitamin D def, vitamin D receptor mutation) causes?
hypocalcemia due to inadequate calcium absorption.
The compensatory rise in parathyroid hormone causes increased bone resorption, renal calcium reabsorption, and renal phosphorus wasting.
PTH also induces 1-alpha-hydroxylase acitivty, leading to elevated 1,25-dihydroxyvitamin D levels.
What is orthostatic hypotension?
a frequent cause of lightheadedness and syncope and is define as a decrease in systolic (>20 mmHg) or diastolic (>10mmHg) blood pressure on standing from the supine position.
Medications (alpha-1 adrenergic antagonists, diuretics), volume depletion, and autonomic dysfunction are common causes of orthostatic hypotension.
What is infantile hemangioma?
a common, benign vascular tumor that presents soon after birth as a bright red, raised, sharply demarcated plaque.
The natural course of hemangiomas is proliferation in infancy followed by regression in early childhood.
What is myositis ossificans?
characterized by the formation of lamellar bone in extraskeletal tissues (ie, heterotopic ossification), often triggered by trauma.
It typically presents as a painful, firm, mobile mass within a muscle (eg, quadriceps).
Histo: benign metaplastic bone and proliferating fibroblasts without mitotic atypia.
What is EBV mononucleosis?
Presents as fever, pharyngitis, lymphadenopathy, splenomegaly, and atypical lymphocytosis.
EBV is generally transmitted from an asymptomatic virus shedder to a susceptible individual through saliva transfer (eg, kissing)
Which tumors can present at the cerebellopontine angle?
Tumors at the cerebellopontine angle can cause unilateral progressive hearing loss due to compression of the vestibulocochlear nerve (CNVIII).
These tumors are most likely vestibular schwannomas or meningiomas.
MOA of ethosuximide
prevents neuronal burst firing by blocking thalamic T-type Ca2+ channels.
The first line treatment for absence seizures.
MOA of phenytoin, carbamazepine, and valproic acid
inhibit high frequency neuronal firing by blocking Na+ channels.
The contractile mechanism in skeletal muscle depends on?
proteins (myosin II, actin, tropomyosin, and troponin) as well as calcium ions.
What can be injured when you horizontally transect the rectus abdominis muscle?
Horizontal transection of the rectus abdominis muscle must be performed with great caution as the inferior epigastric arteries enter this muscle at the level of the arcuate line.
The inferior epigastric arteries below the arcuate line are susceptible to injury (eg, hematoma) due to lack of a supporting posterior rectus sheath.
What is the power of a study?
indicates the probability of seeing a difference when there is one.
The formula is Power= 1- beta, where beta is the type II error rate.
What are the labs seen in lactose intolerance?
Lactose intolerance presents with flatulence, crampy abdominal pain, and watery diarrhea after dairy product consumption.
It can be acquired by inflammatory/infectious conditions that injure the mucosal brush border of the small intestine where lactase is expressed.
Studies can show increased breath hydrogen content, reduced stool ph, and elevated stool osmolality.
What is acute monoarthritis?
characterized by pain, erythema, swelling, and reduced range of motion in a joint.
It may represent serious pathology such as septic arthritis, especially if accompanied by fever.
Urgent synovial fluid analysis should be performed to evaluate for infection.
Atherosclerosis is initiated by?
repetitive endothelial cell injury, which leads to a chronic inflammatory state in the underlying intima of large elastic arteries as well as in large and medium sized muscular arteries.
Traits of pseudomonas
nonlactose-fermenting, oxidase+, motile, gram-negative rod.
What is the most common cause of malignant otitis externa?
Pseudomonas.
MOE is a serious infection of the ear seen in elderly diabetic patients.
Presents with exquisite ear pain and drainage, and granulation tissue is often seen within the ear canal.
What is seen on physical examination of pulmonary hypertension?
A loud pulmonic component of S2 and an accentuated, palpable impulse at the left sternal border (left parasternal lift due to right ventricular heave)
Umbilical hernias are caused by?
a defect in the linea alba and present as protrusions at the umbilicus that are soft, reducible, and benign.
They can occur in isolation or in association with other conditions (eg, Down syndrome)
What are the 3 types of population pyramids?
expansive= young and growing population, high birth and mortality rates
stationary= stable population, declining birth rates and low mortality rates
constrictive= shrinking population, significantly low birth and mortality rates
How does glucocorticoids effect bone?
Chronic or recurrent glucocorticoid (eg, prednisone) use can lead to loss of bone density.
Glucocorticoids inhibit replication and differentiation of osteoblast precursor cells, increase osteoclast activity, and promote intestinal and renal calcium wasting.
What is buprenorphine?
a semisynthetic opioid with mixed/partial agonist-antagonist activity, resulting in a therapeutic ceiling.
Relative to full opioid agonists, this reduces the risk of dose-dependent adverse effects such as respiratory depression
Innervation of external hemorrhoids
External hemorrhoids, which originate below the dentate line, are covered by modified squamous epithelium and have cutaneous (somatic) nervous innervation from the inferior rectal nerve, a branch of the pudendal nerve.
What confirms the diagnosis of menopause?
Menopause occurs on average at age 51 and is diagnosable retrospectively after 12 months of amenorrhea.
An elevated serum FSH level confirms the diagnosis.
Lymphatic drainage of the rectum proximal to the anal dentate line occurs via?
the inferior mesenteric and internal iliac lymph nodes.
Lymphatic drainage of the rectum distal to the dentate line drain primarily into?
inguinal nodes.
What uses the JAK-STAT pathway?
Growth hormone binds to cell surface receptors, leading to intracellular activation of the JAK-STAT pathway.
Cytokines (eg, interferon) and hematopoietic growth factors (eg, erythropoietin, G-CSF) also use this pathway.
Function of tumor necrosis factor-alpha
TNF-alpha is released from activated macrophages and is one of the most important mediators of the systemic inflammatory response in sepsis.
Other cytokines responsible for inducing the systemic inflammatory response include IL-1 and IL-6
Patients with severe burn injury commonly develop?
a hypermetabolic response that results in an increased basal metabolic rate and often lean muscle wasting.
Administration of oxandrolone, a synthetic testosterone analogue, enhances muscle protein synthesis and decreases protein catabolism, reducing lean muscle loss.
Primary (idiopathic) membranous nephropathy is associated with what antibodies?
IgG4 antibodies to the phospholipase A2 receptor, which might play a role in the development of the disease.
Antibody titers are useful for diagnosis and correlate with disease activity.
What causes an accessory nipple?
Incomplete involution of the mammary ridge during fetal development can lead to an accessory nipple, a well-circumscibed, hyperpigmented papule located anywhere from the axilla to the thigh.
Similar to hormone induced changes in normal breast tissue (eg, due to puberty/menses), they may grow larger and become tender/swollen
What causes gynecomastia in men with hypogonadism (low testosterone)?
The adrenal cortex produces estrogen precursors (eg, androstenedione, dehydroepiandristerone (DHEA), DHEA sulfate, which are subsequently aromatized to estrogens in peripheral tissues
In men with hypogonadism, the resulting elevation in the estrogen/testosterone ratio can produce gynecomastia.
Black gallstones form due to?
supersaturation of the bile with bilirubin, which precipitates with calcium to form calcium bilirubinate stones.
This typically occurs in the setting of chronic hemolysis (eg, sickle cell disease) or altered enterohepatic circulation of bilirubin (eg, Crohn disease, ileal resection)
What is the cause of cholelithiasis in women who are pregnancy or using oral contraceptives?
Estrogen induced cholesterol hypersecretion and progesterone induced gallbladder hypomotility
What should be implemented in patients receiving chronic red blood cell transfusions?
Chelation therapy with deferoxamine.
Deferoxamine prevents iron-induced cardiotoxicity and congestive heart failure from developing in this patient population.
Acute lesions to the cerebellar vermis typically cause?
truncal and gait ataxia due to impaired modulation of the medial-descending moto systems.
Involvement of the lower vermis and the flocculonodular lobe also causes vertigo/nystagmus due to dysregulation of the vestibular nuclear complex.
Massive, life-threatening hemoptysis is typically due to?
hemorrhage from the high-pressure bronchial circulation.
Bronchiectasis is a common etiology because chronic airway inflammation causes hypertrophied bronchial arteries that are prone to rupture with coughing.
What is syringomyelia?
The combination of fixed segmental loss of upper extremity pain and temperature sensations, upper extremity lower motor neuron signs, and/or lower extremity upper motor neuron signs in the setting of scoliosis suggests syringomyelia.
Labs for SIADH
Ectopic production of antidiuretic hormone from malignancy can lead to the syndrome of inappropriate ADH secretion, a condition of impaired urinary water excretion.
This condition manifests with low serum osmolality, hyponatremia, high urine osmolality, and high urine sodium concentration.
MOA of nimodipine?
Delayed cerebral ischemia due to cerebral vasopasm usually presents 3-12 days after the initial subarachnoid hemorrhage with an acute change in mental status and/or new focal neurological deficits.
Nimodipine, a selective calcium channel blocker, improves outcomes in patients with cerebral vasospasm by inducing cerebral vasodilation and decreasing calcium-dependent excitotoxicity.
What are adverse effects of bisphosphantes (eg, alendronate, risedronate)?
Medication induced esophagitis is a common adverse effect of bisphosphonates.
Bisphosphonates are also associated with increased risk of osteonecrosis of the jaw and atypical femoral fractures.
Function of programmed-death receptor 1 (PD-1)
a checkpoint inhibitor that downregulates the cytotoxic T cell response.
Neoplastic cells often exploit this receptor via the overexpression of PD-1 ligand.
PD-1 receptor inhibitors (eg, pembrolizumab) restore the T cell response, allowing cytotoxic T cells to invade the tumor and induce apoptosis of neoplastic cells
Where in the body does rotavirus (segmented, dsRNA) effect?
Rotavirus is a common cause of self-limited childhood diarrhea in unvaccinated people.
It infects villous enterocytes in the duodenum and proximal jejunum and results in villous blunting, proliferation of secretory crypt cells, and a loss of brush border enzymes; this results in watery diarrhea without fecal leukocytes
What is attributable risk percent (ARP) in the exposed?
represents the excess risk in the exposed population that can be attributed to the risk factor.
ARPexposed = 100 x [(RR-1)/RR]
Following myocardial infarction, collagen deposition and fibrosis within the infarct region and eccentric hypertrophy of surviving myocytes can lead to?
progressive left ventricular dilation and worsening contractile dysfunction. Because much of this remodeling is driven by neurohormonal signaling via angiotensin II, ACE inhibitors (eg, lisinopril) reduce deleterious cardiac remodeling following myocardial infarction, minimizing LV dilation and helping preserve contractile function
Stress urinary incontinence (intermittent, involuntary leakage of urine) is caused by?
weakened pelvic floor muscle support that often occurs due to chronically increased intraabdominal pressure (eg, obesity, chronic cough, prior pregnancies)
What is testicular torsion due to?
twisting of the testis around the spermatic cord (containing the gonadal artery), which can eventually lead to ischemia.
The gonadal arteries arise from the abdominal aorta.
The right gonadal vein drains directly into the inferior vena cava while the left gonadal vein drains into the left renal vein.
In diabetic nephropathy, early adaptive changes in the kidney cause?
a transient increase in glomerular filtration (hyperfiltration). As diabetic nephropathy progresses, glomerular filtration falls, with a concurrent increase in urine albumin loss.
MOA of methynaltrexone
Constipation is the most common side effect of opiate therapy and occurs due to the binding of mu-opioid receptors in the GI tract, which decreases intestinal motility and inhibits ion and fluid secretion.
Methylnatrexone, a peripherally acting mu-opioid receptor antagonist that does not cross the blood brain barrier, can alleviate opioid induced constipation without inducing opiate related withdrawal symptoms
Turner syndrome is associated with what heart conditions?
Associated with congenital anomalies of the aorta, most commonly bicuspid aortic valve.
A bicuspid aortic valve typically creates an early systolic click over the right upper sternal border, often with a faint ejection murmur.
The abnormal structure and altered hemodynamics surrounding the valve accelerate age-related valvular calcification, commonly leading to aortic stenosis or, less commonly, aortic regurg.
What is the correlation coefficient (r)?
indicates where there is a negative (r<0) or positive (r>0) linear relationship between 2 variables.
The closer r is to -1 or 1, the stronger the linear relationship.
A statistically significant (ie, p value < significance level) linear relationshop between 2 variables does not imply that the relationship is causal.
What are prolactinomas?
the most common hormonally active pituitary adenomas.
The excess prolactin produced by these tumors can cause galactorrhea and amenorrhea in premenopausal women.
With a large mass, visual changs and headaches may occur due to compression of the optic chiasm
Function of eosinophils
Eosinophils have bilobed nuclei and numerous eosinophilic granules in the cytoplasm and are important in allergic disease and defense against parasitic infection.
The eosinophilic granules predominantly contain major basic protein, which acts as a potent antihelminthic toxin.
Major basic protein also damages epithelial and endothelial cells and is a major cause of chronic lung damage in asthma
Ventricular septal defect occurs due to?
insufficient development of the interventricular septum and commonly presents with a holosystolic murmur at the left lower sternal border as pulmonary vascular resistance decline in the neonatal period.
Presentation varies from asymptomatic murmur (small defect) to heart failure (large defect)
What are the pulmonary values in COPD?
elevated residual volume (air trapping)
elevated total lung capacity (hyperinflation)
and reduced forced vital capacity
What are the effects of volatile anesthetics?
increase cerebral blood flow.
It is an undesirable effect as it results in increased ICP.
Other important effects of inhalation anesthetics are myocardial depression, hypotension, respiratory depression and decreased renal function
Neonatal intraventricular hemorrhage usually originates from?
the fragile germinal matrix in infants born before 32 weeks gestation and/or with birth weight <1500 g (3 lb 5 oz)
It is a common complication of prematurity that can lead to long term neurodevelopment impairment
What is familial adenomatous polyposis (FAP)?
AD disorder caused by germline mutation to the tumor suppressor gene adenomatous polyposis coli.
Patients with FAP develop hundreds or thousands of colonic polyps; lifetime risk of colon cancer is close to 100%
MOA of direct factor Xa inhibitors (eg, apixaban)
anticoagulants that block the active site of factor Xa, which leads to reduced conversion of prothrombin to thrombin.
This class of meds is administered orally and requires no drug level monitoring.
What is sarcoidosis?
often presents in young women with the insidious onset of respiratory symptoms (eg, cough, dyspnea, chest pain) accompanied by fatigue, fever, and weight loss.
Histo: noncaseating granulomas, which consist of aggregates of epitheloid macrophages, frequently with multinucleated giant cells
What is aldolase B deficiency?
causes hereditary fructose intolerance.
This disease manifests after introduction of fructose into the diet with vomiting and hypoglycemia about 20-30 minutes after fructose ingestion.
These infants can present with failure to thrive, jaundice, and hepatomegaly.
What is the pathogenesis of multiple sclerosis?
involves an autoimmune response (T cell and antibody-mediated) targeting oligodendrocytes and myelin in the central nervous system, leading to slowed nerve conduction with neurologic deficits.
DIfference between benign lymph node and malignant
Benign lymph node enlargement in response to antigenic stimulation is associated with a polyclonal proliferation of lymphocytes.
A monoclonal lymphocytic proliferation is strong evidence of malignancy.
What is seen in congenital syphilis (ie, spirochete infection with Treponema pallidum)?
umbilical cord inflammation with abscess-like foci of necrosis
Infants with secondhand smoke exposure are at increased risk for?
pneumonia because cigarette smoke affects alveolar macrophage function and impairs mucociliary clearance.
What is essential tremor?
Essential tremor is the most common movement disorder.
Patients experience a slowly progressice, symmetric postural and/or kinetic tremor that most commonly affects the upper extremities. Essential tremor is often inherited in an autosomal dominant fashion (referred to as familial tremor).
First-line treatment is the nonspecific beta-adrenergic antagonist propranolol.
Spinal stenosis most common cause
Spinal stenosis occurs most commonly in the lumbar region and presents with posture-dependent lower extremity pain, numbness/paresthesia, and weakness.
The most common cause is degenerative arthritis of the spine, which results in narrowing of the spinal canal due to intervertebral disc herniation, ligamentum flavum hypertrophy, and osteophyte formation affecting the facet joints.
What causes varicose veins?
Chronically elevated venous pressure in the lower extremities can lead to incompetent venous valves and venous dilation (varicose veins).
Venous congestion and tissue ischemia can result in venous stasis dermatitis.
What is the volume of distribution (Vd)?
refers to how well the drug distributes into tissues compared to plasma; the higher the Vd, the greater the drug distribution into the tissues.
The drug concentration (mg/L) is equal to drug dose (mg) divided by Vd(L)
How the the diagnosis of herpes established?
PCR testing, direct fluorescence antibody testing, or Tzanck smear.
The finding of multiple painful genital ulcers and constitutional symptoms in a sexually active patient is highly suggestive of primary genital infection with herpes simplex virus.
What is the afferent and efferent limbs of the carotid sinus?
The carotid sinus is a dilation of the internal carotid artery located just above the bifurcation of the common carotid artery.
The carotid sinus reflex has an afferent limb that arises from the baroreceptors in the carotid sinus and travels to the vagal nucleus and medullary centers via the glossopharyngeal nerve (CN IX); the efferent limb carries parasympathetic impulses via the vagus nerve (CN X)
What is seen in nonseminomatous germ cell tumors?
Most cases of testicular cancer are either seminomatous or nonseminomatous germ cell tumors.
Nonsemiomatous germ cell tumors are composed of partially differentiated germ cells, which often retain the ability to secrete human chorionic growth hormone and alpha-fetoprotein. Serum lactate dehydrogenase, a marker of tissue injury and cell turnover, is also frequently increased.
What is granulomatosis with polyangiitis?
an ANCA associated vasculitis that typically presents with upper (eg, purulent nasal discharge) and lower (eg, cavitary lung lesion) respiratory manifestations and renal insufficiency due to glomerulonephritis.
Biopsy typically reveals a necrotizing arteritis with granulomatous inflammation (eg, epithelioid histiocytes, multinucleated giant cells) and lack of immunoglobulin/complement deposition
How is glucose absorbed at normal plasma concentration versus higher?
At normal plasma concentrations of glucose, the renal tubules reabsorb the entire filtered load of glucose because it is below the maximum tubular reabsorption ability (transport maximum of glucose).
At higher plasma concentrations, glucose is excreted when the filtered amount exceeds the transport maximum.
The serum concentration at which glucosuria begins, called the threshold of glucose, is approximately 200 mg/dL.
What is acute tubular necrosis?
Acute tubular necrosis can be caused by renal ischemia and is characterized by oliguria, increased serum creatinine, and muddy brown casts.
Ischemic injury predominantly affects the renal medulla, which has a relatively low blood supply.
The proximal tubules and the thick ascending limb of the loop of Henle are the most commonly involved portions of the nephron.
How is recurrent herpes treated?
A genital vesicular rash and a positive Tzanck smear suggest genital herpes simplex virus infection.
Recurrence is common and can be mitigated with daily oral valacyclovir (preferred), acyclovir, or famciclovir
What is a cherry hemangioma?
Cherry hemangiomas are small, red, cutaneous papules common in aging adults.
They do not regress spontaneously and typically increase in number with age.
Light microscopy of these lesions shows proliferation of capillaries and post capillary venules in the papillary dermis.
What is cystic fibrosis?
an autosomal recessive disorder in which a defective chloride channel causes impaired clearance of thick, viscous airway secretions.
Patients typically develop a chronic cough, recurrent pulmonary infections, and bronchiectasis (dilated bronchial tree)
What is matching?
Matching is used in case-control studies in order to control confounding.
Matching variables should always be the potential confounders of the study (eg, age, race).
Cases and controls are then selected based on the matching variables so that both groups have a similar distribution in accordance with the variables.
Which beta blocker is preferred in patients with underlying asthma or COPD?
Beta blockers are used in acute myocardial infarction to reduce morbidity and mortality by decreasing cardiac output and myocardial oxygen demand.
Non-cardioselective beta blockers (eg, propranolol, nadolol) can trigger bronchospasm in patients with underlying asthma or COPD.
Cardioselective beta blockers (eg, metoprolol) predominantly affect beta-1 receptors and are preferred in such patients.
What is atomoxetine?
a norepinephrine reuptake inhibitor that can be considered as an alternate to stimulants in the treatment of patients with ADHD who have a personal or family history of substance abuse.
What is primary CNS lymphomas?
occur in immunosuppressed patients, such as those suffering from AIDS.
These tumors arise from B cells and are universally associated with EBV. They are high-grade tumors with a poor prognosis.
Pregnancy is a prothrombotic state due to?
increased procoagulant factors (eg, fibrinogen), decreased anticoagulant factors (eg, protein S), and reduced fibrinolysis.
These physiologic changes protect against maternal hemorrhage with delivery but increase the risk of peripartum venous thromboembolism.
What is a pudendal nerve block?
A pudendal nerve block provides anesthesia to most of the perineum and external genitalia.
It is performed by transvaginal injection of a local anesthetic medial to the ischial spine and through the sacrospinous ligament.
Mechanism of Bacillus anthracis edema factor?
an adenylate cyclase that increases intracellular cyclic AMP, leading to neutrophil and macrophage dysfunction and tissue edema.
The mechanism of action is similar to that of adenylate cyclase toxin, produced by Bordetella pertussis.
Why does atrial septal defects cause right sided volume overload?
Atrial septal defects cause left to right atrial shunting and right sided volume overload with enlargement of the right atrium and right ventricle; left-sided volume overload does not occur as excess flow entering the left atrium cycles back into the right atrium through the septal defect.
In contrast, left to right shunts distal ot the atrioventricular valves (eg, ventricular septal defect, patent ductus arteriosus) initially cause left sided volume overload
Ocular effects of phosphodiesterase 5 inhibitors (eg, sildenafil, tadalfil)
Can cause a transient bluish discoloration to vision. Less common ocular effects include sudden monocular vision loss due to nonarteritic anterior ischemic optic neuropathy; findings include an afferent pupillary defect, decreased visual acuity, and optic disc edema.
What is infantile hypertrophic pyloric stenosis?
characterized by smooth muscle overgrowth of the pylorus. Gastric outlet obstruction leads to the classic presentation of nonbilious, projectile emesis and dehydration in an infant age 3-6 weeks.
What is Hyper IgM syndrome?
presents with recurrent sinopulmonary and gastrointestinal infections due to the absence of CD40 ligand on CD4 T cells.
Lack of interaction between CD40L and CD40 on B cells prevents the development of secondary germinal centers and impairs B cell activation and immunoglobulin class switching
Where in the lung is perfusion and ventilation highest and lowest?
Both perfusion and ventilation are highest in the base of the lung and lowest in the apex; however, the variability in perfusion is greater than that in ventilation.
This causes the ventilation/perfusion ratio to follow the opposite gradient: it is lowest in the base and highest in the apex
Isoniazid side effect
can be directly hepatotoxic, causing acute, mild hepatic dysfunction in 10-20% patients and frank hepatitis (fever, anorexia, and nausea, sometimes progressing to hepatic failure) in a small percentage of patients
How doe hepatitis B virus replicate?
dsDNA - +RNA template - partially dsDNA progeny.
Although it is a DNA virus, HBV uses reverse transcription to generate new viral DNA from a positive-sense RNA template
Massive pulmonary embolism can lead to sudden cardiac death due to?
a sudden loss of cardiac output. Less commonly, SCD may result from cardiac arrhythmia triggered by right ventricular strain and ischemia.
What is acute acalculous cholecystitis?
an acute inflammation of the gallbladder in the absence of gallstones.
It typically occurs in critically ill patients (eg, those with sepsis, severe burns, trauma, immunosuppression) due to gallbladder stasis and ischemia.
CF: fever, RUQ pain, leukocytosis
MOA of cocaine
Cocaine blocks the presynaptic reuptake of catecholamine neurotransmitters, including norepinephrine and dopamine.
With cocaine toxicity, excessive postsynaptic stimulation by catecholamines can lead to arterial vasospasm and increased sympathetic drive, resulting in increased risk of stroke and myocardial infarction.
What is reverse transcription polymerase chain reaction (RT-PCR)?
used to detect and quantify levels of mRNA in a sample. It uses reverse transcription to create a complementary DNA template that is then amplified using the standard PCR procedure.
RT-PCR can be used to diagnose chronic myelogenous leukemia by identifying an mRNA transcript containing both BCR and ABL exons in affected cells.
Plasmodium falciparum can achieve much higher levels of parasitemia than other species of malaria due to?
its ability to infect erythrocytes of all ages. In contrast, Plasmodium ovale and Plasmodium vivax primarily infect reticulocytes, and Plasmodium malariae primarily infects old erythrocytes
Supplemental oxygen administration in patients with COPD can lead to?
increased CO2 retention (oxygen-induced hypercapnia), resulting in confusion and depressed consciousness.
The major cause is reversal of hypoxic pulmonary vasoconstriction, which increases physiologic dead space as blood is shunted away from well-ventilated alveoli.
