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USMLE STEP-1 POINTS MADE EASY
2000 + Important exclusive points
Mostly repeated in USMLE part 1
Made easy to understand
Note : there are many things like this that we have at our institute and we
distribute all this for our students so ill be posting some of sample pointswhich is quite enough to understand about our material
www.gims-org.com
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Addison's disease Adrenal insufficiency can cause hyperpigmented skin due to an increase in
melanocyte-stimulating hormone (MSH). Patients will have electrolyte imbalances due to
aldosterone deficiency and experience severe reactions to minor illnesses due to cortisol
deficiency. Diagnosis is confirmed using the ACTH stimulation test.
Cushing's syndrome Patients with Cushing's syndrome will have characteristic features such as
central obesity with a buffalo hump, moon facies, peripheral muscle wasting, purple striae,
easy bruising, and psychiatric disorders. This disorder is due to glucocorticoid excess.
Diagnosis is confirmed with the dexamethasone suppression test.
Diabetes mellitus Although DM causes polyuria and polydipsia, it cannot account for the patient's
other symptoms.
Hemochromatosis This metabolic disorder, which is also known as bronze diabetes, is an autosomal
recessive disorder resulting from increased absorption of iron from the GI tract.
Iron accumulates in several organs, including the pancreas (causing diabetes),
heart (causing cardiomyopathy), testicles (causing testicular atrophy), skin
(causing increased pigmentation), and liver (causing cirrhosis). Treatment
consists of regular phlebotomy and deferoxamine, an iron chelator.
Wilson's disease This autosomal recessive disorder is caused by impaired copper excretion. Signs and
symptoms include tremor, ataxia, dementia, and psychoses. The classic
ophthalmic finding is Kayser-Fleischer rings (brown-pigmented rings at the edge
of the cornea) from copper deposits. Treat with penicillamine, a copper
chelator.
AcetazolamideA
cetazolamide is a carbonic anhydrase inhibitor. Members of this class of drugs aregenerally not used to treat hypertension, as the diuresis is self-limiting within
two to three days. The mechanism of self-limiting diuresis is as follows: By
inhibiting carbonic anhydrase in proximal convoluted tubules, acetazolamide
causes increased urinary excretion of bicarbonate. As the body bicarbonate level
decreases, excretion slows even with continued diuretic use, and the diuresis
becomes self-limiting.
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Amiloride This potassium-sparing diuretic works in the late distal tubules and the cortical collecting
ducts by inhibiting reabsorption of Na and secretion of K and H. It would be
useful for treatment of hypertension, but it does not have any effect on
reabsorption of calcium. Furosemide is a better option, as it would also helpreabsorb calcium and, therefore, not make the patient's osteoporosis worse.
Clorothiazide This thiazide diuretic inhibits Na/CL cotransported in the early distal convoluted
tubules. It is useful for treatment of hypertension, especially in a patient with
osteoporosis, as it increases calcium reabsorption from urine by an unknown
mechanism.
Furosemide Furosemide is a loop diuretic that works on the medullary ascending loop of Henle by
inhibiting Na/K/2 CL cotransport that accounts for 20% to 25% of reabsorption
of Na. Downstream sites cannot compensate for the sodium excretion, which
makes these drugs very efficacious and useful for treatment of hypertension.
Loop diuretics cause decreased reabsorption of calcium from urine, however,
and they may worsen this patient's osteoporosis condition. In fact, loop
diuretics are often employed for treatment of hypercalcemia (as induced by
malignancy, for example).
Mannitol Mannitol is an osmotic diuretic. Most of the filtered solutes will be excreted in larger
amounts unless they are actively reabsorbed. Osmotic diuretics are not
indicated for treatment of hypertension, but may be used to decrease cerebral
edema and intraocular pressure.
Cavernous sinus This sinus contains cranial nerves III, IV, V, and VI as well as the internal carotid
artery. Cranial nerves VII and VIII do not pass through here.
Floor of the middle cranial fossa in the trigeminal dural cave The middle cranial fossa contains anumber of structures that carry many important vessels and nerves, including
the cranial nerves associated with ocular motility (III, IV, and VI) and sensation
(V). However, this portion of the fossa does not contain any nerves that would
explain the patient's unilateral hearing loss.
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Internal auditory meatus This structure holds the facial and vestibulocochlear nerves (cranial nerves
VII and VIII) as well as the labyrinthine artery. Because the patient has difficulty
with the facial muscles of both the upper and lower face, we know that the
lesion in cranial nerve VII must be peripheral instead of central (in which only
the lower portion would be involved). Cranial nerve VII also gives rise to the
preganglionic parasympathetic fibers that will innervate the lacrimal gland,
which forms tears. A lesion in cranial nerve VIII in this location also explains
unilateral hearing loss.
Jugular foramen This foramen transmits cranial nerves IX, X, and XI as well as a portion of the internal
jugular artery. These structures are not responsible for the patient's symptoms.
Superior orbital fissure This fissure transmits cranial nerves associated with ocular motility (cranialnerves III, IV, and VI) as well as the ophthalmic nerves and veins. A lesion here
would not explain the patient's auditory symptoms or the lack of abnormalities
in ocular motility.
Leukotrienes productionAspirin, like NSAIDs and acetaminophen, blocks COX-1 and COX-2 enzymes
in the arachidonic acid metabolism. However, the lipoxygenase enzyme
pathway is not blocked, thus funneling most of the arachidonic acid through the
lipoxygenase pathway that produces leukotrienes (LTB, LTC, LTD). LTs are
responsible for increased bronchial tone (i.e., bronchospasm), causing the
respiratory distress symptoms observed in this patient.
Phospholipase A2 deficiency A deficiency in phospholipase A2 would mean that no arachidonic acid is
produced. If there is a deficiency in arachidonic acid, then aspirin has no
negative effect and would not cause respiratory distress.
Prostacyclin production Prostacyclins are by-products of arachidonic acid metabolism via the COXenzyme pathway. Because aspirin blocks both COX-1 and COX-2, no PGIs will be
produced. In addition, PGIs are responsible for decreased bronchial and vascular
tones, as well as decreased platelet aggregation.
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Prostaglandin production Prostaglandins are by-products of arachidonic acid metabolism via the COX
enzyme pathway. Because aspirin blocks both COX-1 and COX-2, no PGE/PGF
will be produced. Prostaglandins are responsible for decreased bronchial and
vascular tones.
Thromboxane production Thromboxane is a by-product of arachidonic acid metabolism via the COX
enzyme pathway. Because aspirin blocks both COX-1 and COX-2, no TXA will be
produced. TXA, however, can increase bronchial tone and result in
bronchospasm, leading to respiratory distress.
Acting out Acting out is the expression of unacceptable thoughts in actions. An example might be
violent behavior toward an inanimate object.
Denial A reality is avoided. This is a very common reaction to hearing any life-changing news.
Displacement Unacceptable thoughts are placed on another person or object.
Isolation Emotions are divorced from events. This response is often experienced after being a
survivor of a plane crash, bombing, or cataclysmic fire.
Rationalization Unacceptable thoughts are replaced by logical reasoning, explaining why something
happened.
Frameshift mutation This type of mutation is caused by the addition or deletion of a base pair, which
changes the reading frame. The resultant protein is usually nonfunctional.
Large segment deletion mutation This type of mutation is usually due to an unequal crossover in
meiosis. Alpha-thalassemia is an example.
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Missense mutation The patient has sickle cell anemia and is in a sickle cell crisis. This condition is
caused by a point mutation in which glutamic acid is replaced with valine. The
result is an unstable hemoglobin molecule.
Nonsense mutation This type of mutation causes the insertion of a stop codon in the reading frame.
The resultant protein is usually shorter and nonfunctional.
Silent mutation In this mutation, the codon is changed but still specifies the same amino acid. There is
no adverse reaction from this type of mutation.
Left middle cerebral artery Blockage of this vessel would cause, among other effects, right-sided
hemiplegia and sensory deficits mainly of the face and arms, a right visual field
defect with inability to gaze to the right, and aphasia.
Right middle cerebral artery Blockage of this vessel would cause, among other things, left-sided
hemiplegia and sensory deficits mainly of the face and arms and left visual field
neglect with inability to gaze to the left. In addition, there may be neglect of the
left side.
Left anterior cerebral artery This vessel supplies the medial aspects of the left hemisphere. Blockage
may cause a weak, numb right leg (and possibly arm symptoms in milder forms).
The face is typically spared.
Right anterior cerebral artery This vessel supplies the medial aspects of the right hemisphere.
Blockage may cause a weak, numb left leg (and possibly arm symptoms in milder
forms). The face is typically spared.
Left posterior cerebral artery This lesion presents as a right-sided visual field deficit, alexia without
agraphia (if the corpus callosum is spared), and possible defects in naming
colors.
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Right posterior cerebral artery This lesion typically presents as a left-sided visual field deficit along
with left-sided sensory loss if the thalamus is affected. There may also be left-
sided neglect.
Left posterior inferior cerebellar arteryThis lesion would cause infarction of the lateral medulla and
inferior cerebellar surface, causing vertigo with vomiting, dysphagia, and
dysarthria. In addition, there would be nystagmus looking toward the left, left
sided Horner's syndrome, and loss of pinprick sensation on the left side of the
face and on the right side of the trunk and extremities. This condition is also
known as Wallenberg's syndrome.
Right posterior inferior cerebellar artery This lesion would cause infarction of the lateral medulla and
inferior cerebellar surface, causing vertigo with vomiting, dysphagia, anddysarthria. In addition, there would be nystagmus looking toward the right,
rightsided Horner's syndrome, and loss of pinprick sensation on the right side
of the face and on the left side of the trunk and extremities. This condition is
also known as Wallenberg's syndrome.
Colorless colonies on MacConkey agar; oxidase positive; blue-green pigment on nutrient agar
Pseudomonas aeruginosa causes pneumonia, urinary tract infections, sepsis,
and hot tub folliculitis. Pseudomonas grows in water and can withstand many
detergents and disinfectants. Pyocyanin gene product gives purulent material a
bluish hue, while pyoverdin is seen as yellow-green with ultraviolet light.
Ultraviolet light may be used to assess cutaneous infection by Pseudomonas in
burn patients. Pseudomonas does not ferment glucose.
Colorless colonies on MacConkey agar; urease positive; blackens triple sugar iron agar Proteus
commonly causes urinary tract infections. Liberation of ammonia by urease
increases urine pH, which increases the potential for struvite stone
development.
Colorless colonies on MacConkey agar; oxidase negative; no gas on triple sugar iron agar Shigella is
characterized by its virulenceonly 100 bacteria must be ingested to develop
shigellosis. Person-to-person acquisition is common, via fingers, flies, food, and
feces. Symptoms begin as fever and abdominal pain, progressing to watery
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diarrhea, which later consists of blood and mucus. No rash is associated with
shigellosis. Lactose is not fermented, as evidenced by colorless colonies on
MacConkey agar.
Colored (pink) colonies on MacConkey agar; urease positive K lebsiella is found in the large intestine,
soil sources, and water sources. The thick capsule is characteristic of this
bacterium. K lebsiella causes pneumonia in the elderly, diabetic patients,
patients with chronic obstructive pulmonary disease, and alcoholics. Pink
coloration on MacConkey plates indicates lactose fermentation. Current jelly
sputum, necrosis, and abscess formation are commonly associated with
pneumonia caused by K lebsiella.
Colored (pink) colonies on MacConkey agar; metallic green sheen on EMB agar E sc heric hia coli causesdiarrhea, urinary tract infections, hemolyticuremic syndrome, and meningitis.
Pink coloration on MacConkey plates indicates lactose fermentation.
A great increase cardiac output and GFR Prazosin does not greatly affect cardiac output, renal
perfusion. or GFR; rather, its action is to decrease arterial and venous resistance.
There is some effect but it is not a dramatic one
A high risk for syncope Syncope often is a side effect of alpha inhibitors. It is often associated with the
first dose, but prazosin is usually given at night to prevent this side effect.
Increased tone in the smooth muscle of the bladder and prostate, leading to decreased urinary
retention The tone in the prostate gland is decreased, which leads to the
decrease in urinary retention.
An association with bradycardia Alpha blockers are associated with tachycardia. Beta blockers
decrease the sympathetic tone on the heart, thereby reducing chrontopic
stimulation to the heart. The alpha blockers affect only the resistance of the
blood circuit, so in response to a relatively low blood pressure the sympathetic
nervous system stimulates the heart to beat faster and harder.
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Chagas disease This disease is caused by infection with T rypanosoma cruzi . It is spread by reduviid
insects, typically in South America. A nodule, or chagoma, forms at the site of
the insect bite. Later complications include megacolon, megaesophagus, and
cardiac abnormalities (conduction block).
Gonorrhea While disseminated gonorrhea can cause joint pains, infection with the responsible
organism is better known for its monoarticular manifestations. In addition, it is
not associated with cranial nerve palsies.
Lyme disease Borrelia burgdorferi is a tick-borne spirochete that is classically associated with
erythema chronicum migrans, often missed by patients. This patient manifested
other signs, such as her malaise and arthralgias. Her facial droop is also a classic
finding for Lyme disease. A tetracycline will be helpful in eradicating the disease.
Rocky Mountain spotted fever This disease is caused by infection with a tick-borne rickettsia
(R. rickettsii ). It presents with headache, fever, and a generalized skin rash
(palms and soles first).
Sleeping sicknessAlso known as African trypanosomiasis, sleeping sickness is not found on the
Eastern Seaboard of the United States. Fever, lymphadenopathy, joint pains,
and CNS changes are characteristic.
HIV This patient is presenting with Pneumocystis carinii pneumonia, which is very often the way HIV
is diagnosed. Unfortunately, this patient likely has a CD4 count less than 200,
which means that his infection is quite advanced. First-line treatment is to get
an ABG and, if the P O2 is less than 70, start steroids, along with high-dose IV
trimethoprim-sulfamethoxazole.
Pasturella multocida This infection is often associated with pain and limited motion to an extremity,
which can lead to osteomyelitis.
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Hypertensive emergencyThis condition is typically seen in patients who have end-organ damage,
such as retinal changes, mental status changes, or renal dysfunction. It does not
specifically present with a picture typical for pneumonia.
Plague The plague (Y ersinia pestis infection) typically presents with tachycardia, tender lymph nodes
(particularly inguinal), high fever, malaise, and myalgia. It can also be associated
with a lobar process on CXR.
Pulmonary tuberculosis While the malnourishment fits this diagnosis, the severe hypoxia is more
indicative of PCP.
Chloroquine One would not use chloroquine against chloroquine-resistant species of Plasmodia.
Iodoquinol This luminal amebicide may be used against E ntameba histolytica, but not against any
species of Plasmodia.
Mefloquine Mefloquine is used for prophylaxis in cases where a patient is predicted to be exposed to
chloroquine-resistant P. falcipartum, as in this case. A blood schizonticide, it has
no effect on extraerythrocytic stages of the malarial parasite. Therefore,mefloquine does not act against P. ovale or P. vivax , which left this patient
vulnerable to malaria caused by infection with one of these species.
Pentamidine This drug is used for trypanosomiasis and in Pneumocystis carinii pneumonia, but not
against malaria.
Primaquine Primaquine is used for prophylaxis in cases where a patient is predicted to be exposed to
P. ovale or P. vivax . This patient was treated with a drug that would decrease
her chances of getting malaria via P. falcipartum. Primaquine is a tissue
schizonticide that works by forming cellular oxidants.
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Pyrimethamine This antifolate drug blocks folic acid synthesis in susceptible protozoa. A blood
scizonticide, it acts primarily against P. falcipartum. This drug is not used for
prophylactic purposes.
Eating undercooked beef is usually how the infection occurs. T aenia saginata (beef tapeworm) is the
cause of infection when undercooked beef is ingested.
In addition to residing in the colon, the infectious agent can migrate to the lung. F ilariaris,
Pargonimiasis, and E c hinoccus are helminths that have been known to migrate
to the lung. E nterobius resides only in the colon.
It is diagnosed by looking for proglottids in the stool. Proglottids can be found in the stool of persons
infected with T aenia saginata and T aenia solium (pork tapeworm)
It is diagnosed with the Scotch-tape test. With E nterobius vermicularis, female worms leave the anus
at night, lay eggs, and die. This causes severe anal itching. Placing Scotch tape
over the area at night will pick up the eggs, which can then be examined under a
microscope to confirm the diagnosis.
E nterobius is transmitted via the fecal-oral route
Continue frequent breast feeding and take an antibiotic. Frequent breast feeding has been shown to
shorten the clinical course of mastitis along with antibiotic treatment. The
organisms will be killed in the infant's stomach, and the antibiotic must be safe
for infants.
Stop nursing and let the infection heal. This will likely lengthen the clinical course and possibly cause
abscess
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We will set you up for a mammogram today. There is no current indication for mammogram. Also,
due to the density of the breast tissue, the study would not find many small
cancers if they existed.
Amyotrophic lateral sclerosis ALS is characterized by both upper and lower motor neuron loss in the
spinal cord, brainstem, and motor cortex. It is a chronic, progressive,degenerative disease.
Conversion disorder Conversion disorder is a psychiatric diagnosis for people with multiple symptoms
that cannot be explained by a medical cause. There must be psychological issues
related to the onset, although the patient is not conscious that these reasons
are why the symptoms have occurred.
Multiple sclerosis MS is a demyelinating disease characterized by multiple neurologic complaints that
are set apart by time and space, and that cannot be explained by a single lesion.
It is typically relapsing-remitting, with symptoms that abate for a period of
months to years before other symptoms appear. It typically is worsened by heat.
Myasthenia gravis MG is an autoimmune disease characterized by antibodies that bind to post-
synaptic acetylcholine receptors. It commonly affects eyesight and causes
fluctuating fatigable ptosis or double vision. Symptoms typically worsen during
the day.
Parkinson's disease Parkinson's disease usually occurs in people older than 50 years. It is caused by
dopamine depletion in the substantia nigra. Typical symptoms include
bradykinesia, resting tremor, shuffling gait, stiffness, and fatigue.
Adenosine phosphoribosyl transferase Adenosine phosphoribosyl transferase is an enzyme used in
the salvage pathway of purines. It is involved in the final step of the pathway,the conversion of adenine to AMP.
Hypoxanthine-guanine phosphoribosyl transferase Hypoxanthine-guanine phosphoribosyl transferase
(part of the salvage pathway for purines) deficiency leads to LeschNyhan
syndrome, which is the clinical picture presented in this case. This is an X-linked
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metabolic disease. These patients will have hyperuricemia and should be
treated with allopurinol. These patients are also mentally retarded.
Nucleoside diphosphate kinase Nucleoside diphosphate kinase is involved in nucleotide synthesis
specifically, the conversion of nucleoside diphosphates to nucleoside
triphosphates, and vice versa.
Purine nucleoside phosphorylase Purine nucleoside phosphorylase converts guanosine to guanine and
inosine to hypoxanthine in the formation of uric acid.
Xanthine oxidase Xanthine oxidase is used in the formation of uric acid. It oxidizes hypoxanthine to
xanthine and xanthine to uric acid.
Asbestos exposure This condition is typically found in shipyard workers from years ago. The disease
process is not normally acute and leads to the classic cancer mesothelioma.
Asthma exacerbation You would expect to see a lower oxygen saturation level, along with wheezing
or decreased air movement on exam.
Carbon monoxide poisoning Anyone who comes in with a 100% oxygen saturation and in severe
respiratory distress with a normal exam should be considered for CO poisoning.
This condition can result from inhalation of car exhaust or an old gas heater that
has just been started up on a cold night. The diagnostic test is the ABG, which
reveals carboxyhemoglobin. The treatment is oxygen, hyperbaric if available.
Carbon monoxide has a very high affinity for hemoglobin; once it binds, it causes
the other three sites in the hemoglobin to be less likely to bind oxygen.
Pneumonia This diagnosis is a possibility but is less likely if the patient is in this much distress and has
a 100% oxygen saturation.
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Pulmonary embolism The oxygen saturation is too high, although the acute onset of the illness is in
line with this diagnosis. A blood gas would be useful in this setting, where you
would expect a low PaO2.
The G2 phase involves checking DNA for errors. This phase follows immediately the S phase, in which
DNA is made. This phase is involved in checking DNA for errors.
In the cell cycle, most cells spend the majority of time in mitosis.Cells typically spend the majority of
time in interphase.
Mitosis involves semiconservative replication, and DNA is typically circular. Mitosis does involve
semiconservative replication, in which daughter DNA is partnered with parental
DNA. DNA is typically not circular.
Most epithelial cells remain in the G0 phase. G0 is a phase that indicates a cell is no longer actively
dividing. Epithelial cells are actively dividing and are not in the G0 phase.
Reverse transcription plays a significant role in DNA replication. Reverse transcription plays a limited
role in cell replication. It is involved in replication of highly repetitive sequencesof DNA.
Antisocial personality disorder Patients with antisocial personality disorder avoid conforming to
societal norms and are not concerned with the welfare of other people, animals,
and objects.
Avoidant personality disorder Avoidant personality disorder is a cluster C personality disorder.
Patients with avoidant personality disorder feel inferior to others, avoid
interacting with others, and are sensitive to rejection.
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Histrionic personality disorder Histrionic personality disorder is a cluster B personality disorder.
Patients with this personality disorder are theatrical and extroverted. They will
often try to sexually seduce others, but they avoid intimate relationships.
Narcissistic personality disorder Narcissistic personality disorder is a cluster B personality disorder.
Patients with narcissistic personality disorder believe that they are more
important than others and are insensitive to the needs of others.
Paranoid personality disorder Patients with paranoid personality disorder (a clusterA personality
disorder) are distrustful of other people and do not take responsibility for their
own problems.
17 and older A person has a good chance of attaining stage IV ethics by age 17 or older, at which
point right behavior is viewed as lawful behavior. Life is seen as sacred in terms
of its place in a categorical moral or religious order.
Change the antibiotic because it is unlikely to cover Streptococcus bovis Vancomycin and gentamicin
provide broad empiric coverage of all the likely organisms of infective
endocarditis: Streptococcus viridans and bovis, and Staphylococcus aureus and
epidermitis.
Consult GI to initiate a GI workup Streptococcus bovis is associated with a 50% risk of colonic
malignancy, making a GI workup mandatory.
Consult Infectious Disease for the unusual nature of the organism Streptococcus bovis is one of the
normal organisms for infective endocarditis. Blood cultures are positive in
approximately 90% of patients. Those for whom it is not positive often have an
unusual organism.
Consult Social Service because the patient is a likely drug abuser Right-sided endocarditis is usually
associated with IV drug use. Tricuspid, rather than mitral, regurgitation would
be expected.
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No change is management is necessary at this time With such a strong association of S. bovis with
colonic malignancy, one would be remiss in not investigating it.
Anomalous insertion of odd-chain fatty acids into membrane lipids The patient is pale, which might
suggest anemia. The most consistent sign of B12 deficiency is loss of vibration
sense in the legs, which can extent to the trunk. Changes in mental status are
frequently observed and include irritability, confusion, suspiciousness, and
emotional instability. Lack of cobalamin leads to accumulation of methylmalonyl
CoA and propionyl CoA. Excess propionyl CoA leads to displacement of succinyl
CoA, which results in formation of anamolous odd-chain fatty acids in
membrane lipids.
Prescribe a trial of ativan Night terrors are nightmares that are not recalled.
Prescribe a trial of imiprimine Imiprimine is used for bedwetting.
Prescribe a trial of phenobarbital Phenobarbital lessens REM sleep.
Psychiatric referral for forgotten trauma Forgotten trauma does not usually present with isolated
nightmares that are never remembered upon waking and that usually occur
during the first half of the night. They can be familial. Ativan is a benzodiazepine
that lessens stage IV sleep. Night terrors occur during stage IV sleep, so
benzodiazepines are often helpful for night terrors.
Which hormone is responsible for insulin resistance in gestational diabetes mellitus?
hPL Human placental lactogen is believed to be the main culprit in the development of GDM in
pregnant women. This hormone, which is produced in the placenta, is important
for ensuring a constant nutrient supply to the fetus. It causes lipolysis and hence
increases free fatty acids. It also has diabetogenic effects on the mother and
leads to increased levels of insulin and development of diabetes.
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hCG is not believed to play a role in the development of GDM.
Estrogen Estrogen is not believed to play a role in the development of GDM.
LH Luteinizing hormone is not believed to play a role in the development of GDM.
Progesterone Progesterone is not believed to play a role in the development of GDM.
He complains of a circular, red, itchy patch of skin on his right forearm.
This is a dermatophyte infection of a microsporum species. Certain microsporum species, when hairs
are involved, will fluoresce under a Wood's lamp. Microsporum species infect
only hair and skin.
This is a dermatophyte infection of the epidermophyton species. Epidermophyton species do not
fluoresce under a Wood's lamp. E . floccosum infects skin and nails, but not hair.
Further examination of this area is warranted to narrow down the fungal species infecting the
individual. Of the species that cause dermatophyte infections, only microsporum
will fluoresce under a Wood's lamp.
This is a dermatophyte infection of a trichophyton species. Lyme disease is caused by Borrelia
bergdorferi, which is transmitted by a tick bite.
This is an erythema migrans rash of Lyme disease. The erythema migrans rash, which is usually
described as a bulls-eye' rash, does not fluoresce under a Wood's lamp. It is the
hallmark rash of Lyme disease. Lyme disease is caused by infection with Borrelia
bergdorferi, which is transmitted by a tick bite.
Epidural hemorrhage An epidural hemorrhage may follow a blow to the head. It usually presents with
a brief loss of consciousness, followed by a lucid interval that may last several
hours, followed by drowsiness and coma. Bleeding is usually from a torn artery,
most commonly the middle meningeal artery.
Intracerebral hemorrhage Intracerebral hemorrhages are most commonly seen in patients with
hypertension. They may produce a paralytic stroke.
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Subhyaloid hemorrhage A subhyaloid hemorrhage is a hemorrhage in the eye between the retina and
vitreous body. It may be seen in conjunction with a subarachnoid hemorrhage.
Subarachnoid hemorrhage A subarachnoid hemorrhage most commonly occurs as the result of an
aneurysm of an intracranial artery. It results in signs of meningeal irritation,
such as severe headache, stiff neck, and loss of consciousness. There is no lucid
interval.
Subdural hemorrhage This injury typically follows a blow to the head that forcefully moves the brain
inside the skull. It is seen most commonly in the elderly population secondary to
shrinkage of the brain. There is no lucid interval.
Common hepatic artery The common hepatic artery runs along the upper edge of the pancreas before
dividing into the proper hepatic artery and gastroduodenal artery. It is not found
near the cystohepatic triangle.
Cystic artery The cystic artery travels through the cystohepatic triangle and is the most likely artery to
be injured during a cholecystectomy.
Left hepatic artery The left hepatic artery supplies the left portion of the liver. It is not located near
the cystohepatic triangle
Right gastric artery The right gastric artery supplies the stomach and is not likely to be injured during
a cholecystectomy.
Right hepatic artery The right hepatic artery supplies the right side of the liver and gives rise to the
cystic artery, which lies in the cystohepatic triangle. While it may be injured
during a gallbladder surgery, it is not the most common artery damaged during
dissection of that area.
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P. falciparum The most feared form, it causes malignant malaria, which can manifest as cerebral
malaria. Cerebral malaria can lead to coma and is associated with a mortality
rate in excess of 20%.
P. malariae This organism causes benign quartan malaria. When chronic, P. malariae infection is also
associated with nephrotic syndrome due to glomerulonephritis.
P. ovale This organism causes benign tertian malaria. One important consideration with this parasite
is that hypnozoite forms can be present in the liver, causing relapse. For this
reason, primaquine must be added to the therapy.
P. simiovale This strain infects simian species. The four human malarial species are P. falciparum,
P. ovale, P. vivax , and P. malariae.
P. vivax This organism causes benign tertian malaria. One important consideration with this parasite
is that hypnozoite forms can be present in the liver, causing relapse. For this
reason, primaquine must be added to the therapy. In addition, P. vivax can be
associated with delayed splenic rupture.
Routine lab work shows an elevated bilirubin level of 2.3 mg/dL (normal = 0.21.0 mg/dL).
Gilbert's syndrome Gilbert's syndrome is often found by the presence of an elevated bilirubin level on
routine lab work in an otherwise asymptomatic individual. The bilirubin level
fluctuates, and may be elevated by stress, exercise, infection, or fasting. Patients
may notice scleral icterus or mild jaundice of the skin during these periods.
Gilbert's syndrome affects 3% to 7% of the population and is more common in
males than in females. The hyperbilirubinemia is caused by reduced hepatic
glucuronyl transferase activity.
Cirrhosis This patient has no risk factors for cirrhosis, including no reports of excessive alcohol use, no
hepatosplenomegaly, and normal liver function tests.
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CriglerNajjar syndrome type I In CriglerNajjar Syndrome type I, the patient has no glucuronyl
transferase, kernicterus, and early death.
CriglerNajjar syndrome type II In CriglerNajjar syndrome type II, the patient has low levels of
glucoronyl transferase. Patients are usually diagnosed early in life, with severe
jaundice and a bilirubin level of 917 mg/dL.
Hemolytic anemia Hemolytic anemia is characterized by an elevated bilirubin level; however, the
complete blood count would reveal decreased hemoglobin and hematocrit
levels. The patient would also have an elevated reticulocyte count.
Decreased calcium, increased phosphate, normal alkaline phosphataseA patient with decreased
calcium, increased phosphate, and normal alkaline phosphatase would most
likely present with renal insufficiency.
Normal calcium, normal phosphate, increased alkaline phosphataseA patient with normal calcium,
normal phosphate, and increased alkaline phosphatase would not suggest
osteoporosis.
Increased calcium, decreased phosphate, increased alkaline phosphataseA patient with increased
calcium, decreased phosphate, and increased alkaline phosphatase would not
have osteoporosis but could be a candidate for hyperparathyroidism.
Increased calcium, increased phosphate, normal alkaline phosphataseThese lab results would not
suggest osteoporosis but could suggest vitamin D intoxication.
Normal calcium, normal phosphate, normal alkaline phosphatase This patient most likely has
osteoporosis; therefore, her calcium, phosphate, and alkaline phosphatase
would most likely be normal.
For which of the following cases is confidentiality allowed to be broken?
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A patient is confides in you her plan for killing another person A person with a plan to harm another
person needs to be taken seriously. If there is no other way to warn the person
at risk, it is the obligation of anyone who knows of this plan to break
confidentiality.
A husband calls your office for his wife's test results without having her explicit permission to give outany information This scenario does not meet the requirements for breach of
confidentiality.
A parent asks you whether her teenage daughter has been taking birth control pills In most states,
teenagers are granted confidentiality from their parents regarding sexual
matters.
The local TV station contacts the emergency room to verify whether a celebrity has been recently
treated All patients, including celebrities, have the right to privacy and not to
have their presence confirmed or denied unless they authorize it.
Lysosomal storage Diseases such as Gaucher disease do not give the clinical findings described here.
An alpha-1,6-glucosidase deficiency In Cori's disease, patients lack a debranching enzyme.
A glucose-6-phosphatase deficiency In Von Gierke's disease, patients exhibit severe fasting
hypoglycemia and have increased amounts of liver glycogen.
A glycogen phosphorylase enzyme deficiency In McArdle's disease, patients exhibit cramps and
weakness after minimal exertion.
A lysosomal glucosidase deficiency In Pompe's disease, patients often die within the first year because
of a defective pump.
Which of the following hormones is responsible for stimulating pancreatic enzyme secretion,
stimulating gallbladder contraction, and inhibiting gastric acid secretion?
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Cholecystokinin Cholecystokinin is responsible for these activities. It is stimulated by amino acids and
fatty acids.
Gastrin Gastrin stimulates gastric motility and the secretion of pepsinogen, hydrochloric acid, and
intrinsic factor.
Pepsin Pepsin is stimulated by acid and begins the process of protein digestion.
Secretin Secretin inhibits gastric acid secretion and stimulates bicarbonate secretion by the pancreas.
Somatostatin Somatostatin inhibits gallbladder contraction, pancreatic fluid secretion, small-bowel
fluid secretion, gastric acid secretion, and pepsinogen secretion. It is responsible
for the release of glucagons and insulin.
Antisocial personality disorder Antisocial personality disorder is a cluster A personality disorder.
Patients with conduct disorder in childhood have an increased risk of developing
antisocial personality disorder. Patients with antisocial personality disorder will
avoid conforming to societal norms and are not concerned with the welfare of
other people, animals, and objects.
Avoidant personality disorder Avoidant personality disorder is a cluster C personality disorder.
Patients with avoidant personality disorder feel inferior to others, avoid
interacting with others, and are sensitive to rejection.
Histrionic personality disorder Histrionic personality disorder is a cluster B personality disorder.
Patients with this personality disorder are theatrical and extroverted. They will
often try to sexually seduce others, but they avoid intimate relationships.
Narcissistic personality disorder Narcissistic personality disorder is a cluster B personality disorder.
Patients with narcissistic personality disorder believe that they are more
important than others and are insensitive to the needs of others.
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Paranoid personality disorder Patients with paranoid personality disorder (a clusterA personality
disorder) are distrustful of other people and do not take responsibility for their
own problems.
Group B streptococci, E . coli, and Listeria Group B streptococci, E . coli, and Listeria are the common
causes of meningitis in newborns.
Listeria and E . coli While Listeria and E . coli are common causes of meningitis in the newborn, answer
A is correct because it includes Group B streptococci, a common cause of
meningitis in newborns.
N. meningitidis and H. influenzae B N . meningitidis and H. influenzae B are common causes of
meningitis in children, but not newborns. The incidence of infection with
H. influenzae B is decreasing due to the widespread use of the prevnar vaccine
against this pathogen.
S. pneumoniae and gram-negative rods S. pneumoniae is an uncommon cause of meningitis in
newborns, but it is a common cause of meningitis in children and adults. Gram-
negative rods are a common cause of meningitis in the elderly.
Staphylococcus aureus and Klebsiella pneumoniae Staphylococcus aureus and K lebsiella pneumoniae
are rare causes of meningitis.
Decreased number of CD4 count and increased p24 antigen One month after infection with HIV,
patients will have decreased levels of CD4 lymphocytes; this level eventually
increases two to three months after infection. One month after infection, p24antigen levels peak and then decrease by two months post-infection.
Increased anti-gp120 antigenAnti-gp120 antigen does not appear until 6 weeks after infection and
peaks around 812 weeks post-infection.
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Increased anti-p24 antigen Anti-p24 antigen does not appear until 6 weeks after infection and peaks
Normal CD4 count and increased p24 antigen One month after infection with
HIV, patients will have decreased levels of CD4 lymphocytes; this level
eventually increases two to three months after infection. around 812 weekspost-infection
Normal CD4 count and increased p24 antigen One month after infection with HIV, patients will have
decreased levels of CD4 lymphocytes; this level eventually increases two to
three months after infection. One month after infection, p24 antigen levels peak
and then decrease by two months post-infection.
Normal CD4 count and undetectable p24 antigen One month after infection with HIV, patients will
have decreased levels of CD4 lymphocytes; this level eventually increases two to
three months after infection. One month after infection, p24 antigen levels peak
and then decrease by two months post-infection.
The husband suffers from a kinesin deficiency The deficiency is in the dynein protein
The patient suffers from Kartagener's syndrome The constellation of infertility,
bronchiectasis/sinusitis, and situs inversus should make you think of
Kartagener's syndrome. These patients suffer from a deficiency of the dynein
protein found in cilia that is responsible for ciliary motion. In the absence of thiscritical protein, males are infertile secondary to sperm immobility. The lack of
proper ciliary motility also means decreased bacterial clearance from the lungs
and sinuses, resulting in bronchiectasis and chronic sinusitis. The situs inversus is
secondary to improper cell mobility during embryogenesis.
Flutamide The patient has metastatic carcinoma of the prostrate. He has a history of BPH, which is
common in men older than 50 years of age. Superimposed on the BPH the
patient has developed prostate cancer that has now metastasized to his spine
not an uncommon mode of presentation for prostate cancer. Flutamide is an
oral anti-androgen at the level of the prostate gland and prostate cancer cells. It
blocks the stimulation signal for proliferation in these cells and controls the rate
of cell replication.
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Actinomycin D This drug binds to double-stranded DNA and inhibits DNA-directed RNA synthesis. It is
not indicated for prostate cancer.
Carboplatin This drug binds to DNA and creates interstrand cross links. It is not indicated for prostate
cancer.
Interferon-alpha, -beta, or -gamma Interferons are not indicated for prostate cancer.
Mitomysin C This alkylating drug is not indicated for prostate cancer.
A 24-year-old male is thrown from a car that he drove into a tree. He suffers from a T6 spinal crush
injury. After he recovers from his acute injury, what is the most appropriate
course of action regarding his bladder?
The bladder should remain catherized until the patient's micturation reflexes return. The patient can
then be taught to cutaneously stimulate the genital area to stimulate a
micturation reflex. In this case, spinal shock causes complete suppression of the
micturation reflex for the first few days.
The patient will have frequent bladder reflux with resulting bladder infections. Bladder dyssynergia can
be caused by upper spinal cord lesions, which causes ureteral reflux.
The bladder is paralyzed, and the patient will have to use abdominal compression and straining to void.
Bladder paralysis will be caused by lesions below T12. Abdominal straining and
compression, called Crede's maneuver, will often allow voiding.
The patient will have a bladder that fills and dribbles urine continually. Lesions that affect the sensory
nerves prevent normal micturation reflex. The bladder will fill to capacity and
overflow a little at a time.
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The patient should be taught how to self-catherize, because he will never be able to control his
bladder. Self-catherization is appropriate if the patient can never control his
bladder. This permanent condition can be caused by loss of sensory nerves.
Codeine This drug is a narcotic. Narcotics have an addictive potential.
Heroin This drug is a narcotic. Narcotics have an addictive potential.
Hydrocodone This drug is a narcotic. Narcotics have an addictive potential.
Morphine This drug is a narcotic. Narcotics have an addictive potential.
Tramadol This agent is the only non-narcotic drug on the list. A patient with a history of substance
abuse (no matter what the substance of abuse was) must not be given
medications that have the potential to be addicting and abused. The diagnosis
of substance abuse is a lifetime diagnosis. Patients so diagnosed, even if their
addiction resolves, continue to maintain that diagnosis for life.
A 25-year-old female has recently had her first psychotic break. After many months of therapy, she has
been diagnosed with paranoid schizophrenia. She has been responding well to her
inpatient olanzapine regimen, and you would like to continue this medication with
her while following her in the outpatient setting. Which of the following features
of her family history would be of the greatest concern to you?
Three first-degree relatives with type II diabetes mellitusThere is an established genetic component to
type II diabetes mellitus. Olanzapine has been shown to cause significant
increases in weight, which in turn promotes a state of hyperinsulinemia and
insulin resistance. It would be worrisome to start a patient with a significant
family history of diabetes mellitus on a medication that would further increase
her risk of developing this disease via weight gain and insulin resistance.
A 65-year-old woman comes into your office complaining of a left-sided headache, jaw pain, and stiff,
achy shoulders for about one week. She has no other medical problems and has
never had a headache before this presentation. On examination, she has a
prominent, pulsating left temporal artery that is very tender to palpation. Yoususpect temporal arteritis (giant-cell arteritis) and decide to do a biopsy to
confirm the diagnosis. What is the best course of action in the meantime, while
waiting for the results?
High-dose prednisone A serious consequence of untreated temporal arteritis is blindness due to
inflammation extending to the optic nerve. If your clinical suspicion is high, it is
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best to start steroids immediately. If the biopsy is negative for temporal
arteritis, the short course of steroids is unlikely to have any adverse effects.
Tylenol for headache relief Although Tylenol can help relieve pain symptoms and could be given as an
adjuvant to treatment, it is also important to start the patient on steroids.
Nothing; wait for results before giving any treatment Any delay in treatment while waiting for the
results increases the patient's risk of blindness.
Antibiotics Temporal arteritis is not an infectious process, but rather is caused by chronic
inflammation of large blood vessels. Antibiotics would not help reduce the
inflammation.
Have other family members come in for evaluation Temporal arteritis is not a hereditary process.
However, its incidence increases with advancing age. If family members present
with similar complaints, it is best to have them evaluated.
During a busy day in the emergency room, a 37-year-old male presents complaining of acute epigastric
abdominal pain, describing it as shooting straight through to my back. He alsostates that he has not been able to eat because of nausea and vomiting. On
examination, the patient is afebrile and uncomfortable, and he requests
medication for his pain. He appears intoxicated. The abdominal exam reveals mild
distention, absent bowel sounds, and extreme pain on palpation, but no rebound
tenderness. Initial lab results show elevated amylase and lipase levels. A KUB
shows multiple calcifications in the abdomen. Which diagnosis best explains these
results?
Pancreatitis In the setting of alcohol use, this patient's presentation is convincing for acute
pancreatitis in the context of chronic pancreatitis.A
lcohol use and gallstones arethe main causes of acute pancreatitis in the United States; the presence of
pancreatic calcifications suggests that the patient has experienced previous
episodes.A follow-up CT scan or ultrasound may reveal pancreatic fluid
collections, indicating the development of a pseudocyst.
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Aortic dissection Patients with aortic dissection classically complain of intense epigastric pain that
radiates to the back, but do not have elevated lipase and amylase levels.
Appendicitis This patient presents with acute, fixed, and intense epigastric pain. Appendicitis typically
begins as colicky central abdominal pain that worsens as it localizes to the right-
lower quadrant. It is not generally associated with elevated lipase levels.
Esophagitis Erosive conditions of the esophagus are not associated with elevated amylase and lipase
levels.
Gastritis Although patients with gastritis often present with epigastric pain and nausea, serum
amylase and lipase levels are not typically elevated. In addition, abdominal
calcifications in this setting are strongly suggestive of pancreatic calcifications,
indicating that the patient likely has a chronic condition.
As an intern in the ER, you evaluate a 55-year-old patient with a history of a duodenal ulcer who
complains of severe, nonremitting, mid-epigastric pain and vomiting of bright red
blood. An upright X ray reveals free air under the diaphragm, and you suspect a
perforated ulcer. Endoscopy confirms your suspicion and reveals a perforated
ulcer in the posterior portion of the first part of the duodenum. Perforation into
which artery best explains this patient's symptoms?
Gastroduodenal artery This artery descends immediately behind the first part of the duodenum;
ulcers commonly penetrate into this vessel. It arises from the common hepatic
artery and gives off the right gastroepiploic and superior pancreaticoduodenal
arteries.
Cystic artery This artery does not run near the first portion of the duodenum.
Hepatic artery The right and left hepatic arteries are branches of the proper hepatic artery, which is
itself a branch of the common hepatic artery. These arteries are closer to the
liver and the second portion of the duodenum.
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Right gastric artery This artery runs along the lesser curvature of the stomach away from the
duodenum.
Right gastroepiploic artery This artery runs along the greater curvature of the stomach.
According to current thinking, which of the following is the first-line treatment for congestive heart
failure?
ACE inhibitors ACE inhibitors decrease vascular resistance, decrease blood pressure, and increase
cardiac output. They also blunt the release of aldosterone and epinephrine
caused by angiotensin II. Studies have shown that ACE inhibitors reduce the
chances of arrhythmic death, MI, and stroke. Interestingly, studies scheduled to
be published in the near future may make new statements about ACE inhibitors
and beta blockers, so this answer may change in the future. Currently, however,
ACE inhibition is the correct answer for this question.
Beta blockers Once thought to be contraindicated in CHF, these medicines are now finding a place in
the treatment of CHF and the prevention of further disease and complication.
They are not the first-line option, however.
Digitalis Widely used in heart failure, digitalis has no effect on mortality and is not used as a first-line
therapy. Its utility actually derives from its ability to decrease the number of
hospitalizations of patients with CHF.
Diuretics While useful in heart failure because of its ability to reduce the effects of volume overload
and decrease the symptoms of paroxysmal nocturnal dyspnea and orthopnea,
diuretics are is not the first-line option for CHF.
Macrolides This class of drugs, and all classes of antibiotics, have not been shown to offer any
benefits in the treatment of CHF.
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A 25-year-old woman with regular menses is given an estrogen challenge. The challenge consists of
exogenous estrogen supplementation to see if her LH level will increase. Which of
the following regimens would be most effective?
Estrogen 10 days after menses High levels of estrogen are needed to stimulate adequate LH
production.
Estradiol 20 days after menses If estradiol was given 20 days after menses, then the cycle would
already be in the luteal phase. Once in the luteal phase, the LH level will not rise
until the next cycle.
Progesterone 10 days after onset of menses Progesterone level is typically very low during the
follicular phase. This hormone does not stimulate LH production.
Progesterone 20 days after onset of menses Progesterone does not stimulate LH production.
Synthetic FSH 15 days after onset of menses FSH is the not the principal stimulator of LH production.
A 47-year-old African American male presents for follow-up for depression. He denies improvement
after eight weeks of sertraline with good compliance. His smoking has increased
to three packs per day, up from two packs per day for 30 years. He admits tointermittent back pain, incapacitating pruritus, and a 30-pound weight loss.
Umbilical tenderness and a distended gallbladder are noted on physical
examination. Which of the following is the most likely to be true in this case?
The pancreatic head is the origination site of the patient's pancreatic carcinoma. Pancreatic carcinoma
most often occurs in the pancreatic head. This location allows earlier
identification as compared to the tail of the pancreas. However, surgical
procedures require removal of the pancreatic head, gallbladder, and a portion of
the duodenum (Whipple procedure). Migrating thrombophlebitis is often
observed with pancreatic carcinoma.
No association has been made between cigarette smoking and pancreatic carcinoma. Smoking
increases the risk of pancreatic carcinoma.
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The patient's tumor represents the malignant transformation of exocrine cells. Duct cells represent 4%
of the healthy pancreas, but 99% of primary pancreatic malignancies originate
from duct cell neoplasia.
The patient's gallbladder distention is due to choledocholelithiasis from elevated cholesterol
nucleation. Courvoisier's sign notes the tendency of biliary-tractrelated
malignancies to lead to gallbladder distention, but cholelithiasis-related disease
results in a normal- or reduced-size gallbladder.
Lifespan has been improved to greater than 10 years with current chemotherapy regimens.The
prognosis for pancreatic carcinoma remains poor, with death typically occurring
within one year of diagnosis.
A four-year-old white female presents to the pediatric clinic for follow-up due to developmental delay.
Her medical history reports frequent episodes of otitis media, bronchitis, and
pneumonia. Physical examination reveals coarse facial features, gingival
hypertrophy, joint stiffness, claw hand deformity, and generalized hypotonia.
Significant motor delay is appreciated. Electron microscopy of muscle biopsy
demonstrates numerous intracytoplasmic inclusions, which are membrane-bound
vacuoles filled with fibrillogranular material. I-cell disease is suspected. What is
the function of the deficient enzyme?
Phosphorylation of mannose residues Failure to phosphorylate mannose residues targets intracellular
enzymes to extracellular sites. Lysosomal enzymes cannot be routed
appropriately, and enzymes accumulate in the plasma. Lysosomal substrates
accumulate, as the lytic enzymes are not present intracellularly. Key findings are
gingival hypertrophy and hypotonia. Death is common before the patient
reaches age eight years.
Breakdown of dermatan sulfate and heparan sulfate Mucopolysaccharidoses and another class of
lysosomal disorders, Hurler's syndrome, Hunter's syndrome, Scheie's syndrome,
and Sanfilippo's syndrome are all disorders due to faulty metabolism of
dermatan sulfate and heparan sulfate. Hurler's syndrome and Scheie's syndrome
are notable for corneal clouding. Scheie's syndrome is the only listed disorder
with normal intellect and life expectancy. Hunter's syndrome is X-linked, where
the remaining disorders are autosomal recessive.
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Cleavage of disaccharides Brush border enzymes include lactase and isomaltase sucrase. These
disorders cause flatulence due to bacterial digestion of disaccharides and
osmotic diarrhea.
Cleavage of fructose Fructose intolerance is caused by lack of aldolase B. Phosphorylated fructose
accumulates within the cell due to insufficient metabolism. Possible sequelae
include hypoglycemia, hemorrhage, and liver failure. Avoidance of fructose and
sucrose is curative.
Degradation of sphingolipids Lysosomal hydrolytic enzymes are missing in this class of enzyme
deficiencies. Sphingolipidoses include Tay-Sachs disease, Meimann-Pick disease,
and Fabry's disease. Lysosomal accumulation of sphingolipids often leads to
mental retardation and shortened life expectancy.
Metabolism of galactose Galactosemia, as caused by uridyltransferase or galactokinase deficiency,
may lead to adverse effects that include cataract formation and mental
retardation. Accumulation of galactitol damages nerve tissue, liver, kidney, and
the lens of the eye. Strict avoidance of galactose and lactose is required.
Which of the following antibiotics works by blocking cell-wall synthesis through the inhibition of
peptidoglycan cross-linking?
Penicillin Along with the cephalosporins, imipenem and actreonam, penicillin inhibits peptidoglycan
cross-linking.
Aminoglycosides Block protein synthesis at the 30S ribosomal subunit, as do the tetracyclines.
Chloramphenicol Blocks protein synthesis at the 50S ribosomal subunit.
Clindamycin Blocks protein synthesis at the 50S ribosomal subunit.
Macrolides Block protein synthesis at the 50S ribosomal subunit.
Quinolones Block DNA topoisomerases.
Rifampin Blocks mRNA synthesis.
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Sulfonamides Block nucleotide synthesis.
Vancomycin Blocks peptidoglycan synthesis.