Uworld- block 1 Flashcards
Most common causes of metabolic alkalosis
- Vomiting or nasogastric tube(hypotension)
- Thiazide or loop diuretics
- Mineralcorticoids excess(hypertension)
What are the most important steps in the workup of metabolic alkalosis
Checking the patients volume status and urine chloride
Differential diagnosis of metabolic alkalosis
In case of low chloride in urine: vomiting, nasogastric aspiration and prior diuretic use.
High chloride in urine: if euvolemia or hypovolemia are present -> bartter and gitelman syndromes
And if hypervolemia is present that means a status of excess mineralocorticoids
Which are saline responsive and unresponsive in treatment of metabolic alkalosis
Saline responsive : vomiting, nasogastric, diuretics
Saline unresponsive: barrter and gitelman syndrome, as well as excess mineralocorticoids.
Restlessness and purposeless jerking movement after a history of sore throat
Acute rheumatic fever -> sydenham chorea
Jerking extremity movement in Parkinson disease patients
Its seen only in case of levodopa intoxication
What is the role of thiamine in brain
Thiamine i a key coenzyme for pyruvate dehydrogenase which is involved in glucose metabolism. Its deficiency results in patients inability to metabolize glucose into energy. The most affected area in case of thiamine deficiency in the brain is the mammillary body( part of circuit of papez)
What is the character of inheritance for hemophilia a and b
X-linked recessive disorder
GRaft versus host disease (gvhd)
It can occur following transplantation of organs rich in lymphocytes.
This occur because the patients are severely immunodeficient due to immunosuppressant medications.
This is done via sensetization of T-cells and not B-cells.
GRaft versus host disease (gvhd) presentation
Any organ might be the target of this disease, but usually skin, liver , and gi tract are the most frequently affected. Early signs include a diffuse maculopapular rash the has predilection for palms and soles and may desquamate in severe cases.
Classification of MEN I
MEN I:
- Primary hyperparathyroidism.
- Pituitary tumors( prolactin, visual defects).
- Pancreatic tumors.
MEN II-A
MEN II-A:
- Medullary thyroid cancer(calcitonin).
- Pheochromocytoma.
- Parathyroid hyperplasia.
MEN II-B
MEN II-B:
- Medullary thyroid cancer
- Pheochromocytoma
- Mucosal neuromas, marfanoid habitus.
Thiamine is a cofactor for
- Pyruvate dehydrogenase
- A-ketoglutarate dehydrogenase
- Branched chain a ketoacid dehydrogenase
- Transketolase.
A deficiency in thiamine means that all these enzymes might not work prroporelly.
Chronic thiamine deficiency
If patients with chronic thiamine deficiency is given glucose infusion without thiamine supplementation, acute cereberal damage may occur. It can be diagnosed if baseline erythrocyte transketolase activity is low but increase after addition of thiamine pryiphosphate.
What is the most abundant amino acid in collagen
Glycine
Triple helix
The triple helical conformation of collagen molecules occurs due to the simple and repetitive amino acid sequence within each alpha chain in which glycine occupies every third amino acid position.
Proline in collagen
Proline residues are essential for alpha helix formation because of their ring configuration introduces a kink in the polypeptide chain, enhancing the rigidity oh the helical structure.
When does Hemoglobin F replaced b hemoglobin A
After 6 months.
Hemoglobin H diseaes
It manifests as chronic hemolytic anemia. It has 4 beta chains and its part of a-thalassemia. This have very high affinity for o2 that it doesnt release it.
Melanocyte embryonic derivative
Neural crest cell
Malignant melanoma can lead to
Focal neurological deficit which may manifest as tonic clonic seizures.
Most common cancers that lead to brain metastases
- Lung cancer
- Renal cancer
- Melanoma
Squatting in teratology of fallot- mechanismv
Squatting relieves tet spells. This posture increases systemic vascular resistance (important), without changing the pulmonary vascular resistance, increasing svr:pvr ratio. The increased svr forces a higher proportion of right ventricular output to enter the pulmonary circulation and oxygenate in the pulmonary capillary beds, increasing arterial oxygen concentration and relieving tet spell.
Hypoglycemia signs
Disorientation, sweating, tremor and palpitations.
Predisposing factors for hypoglycemia in diabetes I
Excessive insulin dose, inadequate food intake and exercise .
How is glucose uptake by skeletal muscle is mediated
GLUT-4
Hyperglycemia in type I diabetes patients causes:
Pain, infections, sleep deprivation. Stressful situations increase catecholamines release which raises glucose by decreasing pancreatic insulin secretion and by increasing glycogenolysis and gluconeogenesis
Types of adverse drug reactions: Type A
Type A: predictable reaction due to known pharmacological properties of the drug such as (e.g gastritis following NSAIDs use or nephrotoxicity following aminoglycosides)
Types of adverse drug reactions:Type B
- Exaggerated sensitivity: predictable reaction occurring at lower than expected exposure. (E.g tinnitus after one aspirin use)
- Idiosyncratic: unpredictable reaction in certain patients (e.g non immune hemolytic anemia with primaquine in G6PD deficiency)
3.immunologic (drug allergy): unpredictable, specific immunological reaction.
Examples:
A. {Rapid urticaria or anaphylaxis-> type I}
B. {drug induced hemolysis -> type II}
C. {serum sickness -> type III}
D. {contact dermatitis -> type IV}
Chronic aspirin use- side effects
Tinnitus
ACEI effect on kidney
Decrease efferent arteriolar resistance and systemic vascular resistance.
Spastic bladder
Urinary frequency and urge incontenince.
Usually due to upper motor neuron lesion in the spinal cord.
Its common in MS patients after weeks of spinal cord injury.
Reduced urine flow or elevated urethral pressure present in
Mechanical obstruction such as enlarged prostate or urethral stricture along the urinary tract.
Flaccid bladder
Typically occur in the setting of lower motor neuron lesions such as cauda equina syndrome. Patients will have residual volume (large) of urine after attempted emptying and at the end of the day will experience urinary incontinence.
Heteroplasmy
FA: Presence of both normal and mutated mtDNA, resulting in variable expression in mitochondrically inherited diseases. E.g lactic acidosis or myopathy.
UWORLD: having different mitochondrial genomes within a single cell. The severity of mitochondrial diseases is often directly related to the proportion of abnormal to normal mitochondria within patients cells.
C-section in case of large for gestational age baby
C-section typically involved midline vertical separation of the rectus abdominis muscle, but in case of large for gestational age infant, horizontal transection of the rectus abdominis muscle may be considered.( due to weight or position). If rectus abdominis transacted horizontally, the inferior epigastric arteries must be identified and ligated bilaterally (they are susceptible to injury)
Rectus abdominis covering
Above the arcuate line( below umbilicus- horizontal line), rectus abdominis is surrounded by anterior and posterior sheaths, while below the arcuate line its covered only by anterior sheath.
Insulin effects
- Increase glucose uptake
- Increase glycogen synthesis and decrease glycogenolysis
- Decrease glucagon synthesis (it acts directly on alpha cells in pancreas-> prevents glucagon from interfering )
- Decrease lipolysis and ketogenesis
- Increase protein synthesis in muscles
- Increase renal reabsorption of sodium.
What hormones induce lipolysis
Glucagon Norepinephrine and epinephrine Cortisol Gherilin and growth hormones Testosterone and cortisol
Parenteral nutrition (through central venous catheter ) patients are at high risk of :
Candidemia.
Candida can colonize the catheter and lipid emulsion in the parenteral nutrition solution is though to promote the growth of some candida species.
The morphology of candida includes branching pseudohyphae with blastochonidia. Its almost always susceptible to fluconazole.
Broad based budding yeast
Blastomyces .
Pulmonary infection and occasional dissemination
Coccidioides
Dimorphic fungi, endemic to southwestern united states. Its inhaled organism and can cause pulmonary infection. With occasional dissemination. Especially with immunecompromised patients .
Yeast with thick capsule that doesnt absorb india ink
Cryptococus
Right angle branching hyphae
Characteristic of mucor-mycosis (mucorales). -> invasive disease in immune compromised (doesnt respect normal barriers).
Acid fast staining
- the smear is first treated with an anilline dye ( carbofluchsin)
- the dye (red color) penetrates the bacterial cell wall where it bind to mycolic acid.
- slide is treated with hydrochloric acid and alcohol.
- this acid alcohol dissolve the outer cell membrane of nontuberculosis bacteria, but the presence of mycolic acid in myobacterium prevent it from happening.
- a counterstain such as methylene blue is then applied and taken up be decolorized bacteria. As a result the carbofluchsin acid fast stain produces red myobacteria and blue non-acid fast bacteria.
Mycolic acid
-Its present on myobacterium.
Myobacterium can stain as weak gram positive bacteria, but the difference is that they are encapsulated with mycolic acid.
-its also present in nocardia.
Because it contains fewer mycolic acid its a weak acid fast , gram + bacteria.
Ergosterol
Is the sterol component of fungal cell membrane. This molecule is found in human cell membrane, as human cells have cholesterol in their cell membrane instead.
Clozapine side effects and indication
Atypical antipsychotic. Binds loosely and transiently to dopamine D2 receptos -> fewer extrapyramidal side effects. Indications : -treatment resistance schizophrenia -schizophrenia associated with suicide attempts Adverse effects : 1. Agranulocytosis 2. Seizures 3. Metabolic syndrome
Resperidone side effects
Prolactin levels increased
Ziprasidone side effect
Prolonged QT interval
Gastric varices
Dilated submucosal veins that can cause life threatining bleeding in the upper GI tract. The varcies commonly due to portal hypertension which can be a complication of cirrhosis. It can also be seen with splenic vein thrombosis due to chronic pancreatitis, pancreatic cancer and abdominal tumors.
Varices in fundus of stomach only
Splenic vein thrombosis- usually due to chronic pancreatitis or pancreatic tumor
21 hydroxylase defeciancy
Usually present with ambiguous genitalia, clitoromegaly, in females ,however males have normal genitalia but will present later in life with precocious puberty and salt wasting. bilateral adrenal hyperplasia(most common cause- nearly 90%) is also present.
-It cant convert progesterone into 11-Deoxycorticosterone.
-it cant convert 17-OH progesterone into 11-Deoxycortisol.
This results in the conversion of all the cycle into androgen synthesis.
What is elevated in 21 hydroxylase deficiency
17-hydroxyprogesterone.
uniformly enlarged uterus with normal appearing endometrial tissue on biopsy.
Adenomyosis: Endometrial glandular tissue within myometrium .(endometriosis).
Symptoms include : heavy menstrual bleeding , dysmenorrhea, and enlarged uterus.
Irregulary enlarged uterus with heavy bleeding
Leiomyoma(fibroids)
Adenosine deaminase deficiency
The second cause of SCID, after X-linked SCID.
Adenosine deaminase is present in all cells of the human body and its function is to deaminate adenosine into inosine as first step of elimination of adenosine from the cell.
Adenosine accumulation is toxic to lymphocytes and leads to wide spread death of both T and B cells.
Treatment is bone marrow graft but nowadays reteroviral vectors are used to “infect” patients hematopoietic stem cells with genetic code for deaminase adenosine enzyme.
Superoxide dismutase is deficient in
Amyotrophic lateral sclerosis
Mitral regurgitation severity indicator
Audible S3 gallop .due to the increased regurgitant volume, left atrium contracts against the flow –> increased intensity of S3
Mid systolic click
Its characteristic of mitral valve prolapse. Its caused by sudden tensing of the chordae tendineae as they are pulled taut by the valve leaflets ballooning into the left atrium.
The S2 to Opening snap interval is useful in
Its and indicator of severity of mitral stenosis
Its a diastolic time interval between the closure of aortic valve and abrtupt haltinng of leaflet motion during opening of stenotic mitral valve.
Gaucher disease
Autosomal recessive lyzozomal storage disease. Accumulation of gluocerebrocidase.
Lipid laden macrophages (gaucher cells) are classically described as wrinkled tissue paper or wriknled silk or crumpled newspaper in a bone marrow aspirate.
Hepatosplenomegaly easy bleeding and bruising, fatigue due to pancytopenia, spleen enlargment (massive and prior to hepatic).
Gaucher disease
Sudden onset of palpitations and rapid regular tachycardia that is responsive to carotid sinus massage
Paroxysmal supra-ventricular tachycardia (PSVT)
Carotid sinus massage
It leads to increased afferent firing from the carotid sinus which in turn increase vagal parasympathetic tone . This slows conduction throught the AV node and prolongs the AV node REFRACTORY period, helping terminate the reentrant tachycardia. ‘
Carotid sinus massage stimulates the baroreceptors and increase firing rates from carotid sinus, leading to an increase in parasympthateic output and withdrawl of symphathetic output to the heart.
This is why its not useful in ventriculat tachycardia.
Galrigine and detemir
Long acting insulin as well as NPH
Short acting insulin
Lispro Asparat Glulisine Peak in 0.5-3.0 hrs-- >best option for postprandial hyperglycemia Regular insulin Peak 2-5 hrs Best for diabetic ketoacidosis (IV use)
Gram variable rod
Gardnerella vaginalis:
Graish whitish discharge, fishy odor especially with whiff test (K+ hydroxide addition).
Clue cells.
No vaginal inflammation usually
Vaginal discharge : PH and color
PH>4.5 bacterial vaginosis–> graysih white, fishy odor
PH>4.5 trichomoniasis –> yellow green, malodourus
PH 3.8-4.5 candida —–> pseudohyphae, thick cottage cheese discharge.
Gram negative diplococci in std
N.Gonorrhea
Gram negative intracellular bacterium (STD)
C.Trochomatis
Septate hyphae
Aspergillus
Clear polysaccharide capsule, unstained zone with india ink and stains red with mucicarmine(responisble for red).
Cryptococcus neoformans: can cause meningoencephalitis, cryptococal lung disease with pneumonia like symptoms.
Round yeast with broad based budding and thick
Blastomyces dermatidis
Thick walled spherules that contain small, round endospores
Coccidioides immitis
Small ovoid and budding yeast cells.
Histoplasma capsuatum
Broad hyphae with irregular branching and rare septations
Rhizopus
Doxorubicin side effects
Dilated cardiomyopathy. Use dexrazoxane to prevent.
Pericardial fibrosis
Usually presents following cardiac surgery, radiation therapy or viral infection of the pericardium.
Mechanism of action of statins
(HMG-COA reductase inhibitors) Inhibit the rate limiting enzyme in hepatic cholesterol synthesis. In response to these changes, hepatocytes increase their surface expression of the LDL receptor to increase the uptake of circulating LDL.
Tx generally produces a 20%-50% reduction in serum cholesterol and LDL concentration
Sickle cell trait: clinical
Patients with sickle cell trait are usually asymptomatic with normal Hb levels , however they might develop hematuria, priapism and increased incidence of UTI.
These patients also have relative protection from plasmodium falciparum (malaria)(not immunity)
Vasocclusive pain crises
Vasocclusive pain crises develops in patients with sickle cell anemia are thought to occur when Hb S polymerizes and causes RBC to assume sickle shape typically in response to trigger.(wheather , dehydration … )
Case: dyspnea, othopnea, elevated jugular vein pressure, lower extrimity edema and lung crackles
Acute decompensated heart failure :
Treated with furosemide( loop diuretics) .
Median and ulnar nerve in the hand
Median nerve innervate, thumb, index and middle , theanear eminence
Ulnar: hypothenar eminence little and ring
Carpal tunnel syndrome results from compression on
Its usually due to compression of transverse carpal ligament which is also called flexor retinaculum.
Carpal tunnel syndrome clinical
Pain , parasethesias in the median territory . Motor involvment causes weakness of thumb abduction and opposition, and atrophy of thenear eminence
Clostridium difficile risk factors :
Recent antibiotics, hospitiliazation and PPi.
Especially clindamycin
Sigmoid containing white yellow plaques on the colonic mucosa and biopsy shows that the plaque are composed of fibrin and inflammatory cells
Pseudomembrane colitis
Consumption of undercooked pork
Risk factor for cysticercosis . –> sezuires, subcutaneous nodules or IM calcification.
Serum antibodies to phospholipase A2 receptor (PLA2R)
“Idiopathic membranous nephropathy.”
Its indicative for glomerulonephritis. Its transmembrne receptor found in high concentration in glomerular podocytes and thought to be major antigen in the pathogenesis of “idiopathic membranous nephropathy.”
Mixed cryglobulinemia
Its found in patients with hep C, the renal disease is likely due to IgM deposition in the glomerulus that leads to basement membrane thickening and cellular proliferation.
Hypertrophic obstructive cardiomyopathy murmer increase
- Sudden standing –> decrease preload –> increase murmur.
2. Valsalva and nitroglycerine –> decrease preload –> increases murmur.
Hypertrophic obstructive cardiomyopathy murmur intensity decrease
- Sustained hand grip —> increase afterload .
- Squatting —> increase afterlaod and preload .
- Passive legraise —> increase preload.
When is usually the peak volume after antibiotic therapy
Usually 1/2 hours after Iv or 1 hour after IM dosing whearas the lowest drug dose occurs during the last 1/2 hours before the last dose
Drug concentration, dose, volume of distrbution and etc..
Drug concentration can be calculated by dividing the drug dose by the volume of distribution
Volume of distrbution (Vd)
refers to the theoretical required volume if the drugs were contained completely in plasma, it can vary Depending on how well the drug distribute into the tissues, the higher the Vd the greater the drug binds to tissues,
Half life in first order kinetic
when drug metabolism occurs via first order kinetics the half life represent the amount of time required to lower drug concentration by 50%.
