Block 45 Flashcards
Western blotting
Is used to detect a target polypeptide or protein from within a mixed sample. Potential target proteins are seperated by gel Electrophoresis.
Cerbellar ataxia, telangectasia and increased risk of infection
Ataxia telengectasia syndrome
Autosomal recessive condition due to mutation in ATM gene which is responsible for DNA break repair.
-telengectasia : supreficial blanching nests of distended capillaries
- ataxia
-IgA deficiency
-increased AFP, decreased IgG, IgA, and IgE.
-cerbellar atrophy
Matrix metalloprotinease (MMP)function in wound
Its secreted by various cell types such as macrophages, neutrophils, synovial cells, some epithelial cells.
- it primarily function in the degradation of collagen and other proteins in extracellular matrix.
- MMP activity is important in wound healing, as it encourages both myofibroblast accumulation at the wound accumulation at the wound edges and scar tissue remodeling.
- the amassed myofibroblasts initiate wound contraction during healing by second intention.
- contracture may occur when unusually pronounced MMP activity results in excessive wound contraction.
Diagnosis of GCA (temporal)
- elevated ESR and CRP
- temporal artery biopsy shows intimal thickening, elastic lamina fragmentation and multi-nucleated giant cells.
- angiography isnt as sensetive as ESR and CRP for initial assesment.
Pure red cell aplasia(PRCA)
Rare form of marrow failure charactrized by severe hypoplasia of marrow erythroid elements in the setting of normal granulopoiesis and thrombopoiesis.(normal WBC and platelets).
- the pathogenesis of PRCA often involves the inhibition of erythropoietic precursors and progenitors by IgG autoantibodies or cytotoxic T lymphocytes.
- it has been associated with immune system disease such as thymomas and lymphocytic leukemias.if thymoma is present, removal of thymus can resolve the problem
- it can also arise from B19 infection, the virus pereferntially attacks and destroys pro-erythroblasts. Recent parvovirus infection can be confirmed via the detection of anti-B19 IgM antibodies.
- patients presents with low reticulocytes count, normocytic anemia
Cysteine tellurite agar
Bordett gengou medium
Cysteine tellurite = cornybacterium diphteriae- dark black .
also can be cultured on lofflers medium where it develop cytoplasmic metachromatic granules.
Bordett gengou medium = bortadella pertusis
Aging changes in spirometry
- Patients age >35 experience steady decrease in chest wall compliance as a result of stiffening from Rib calcification and from increased thoracic curvature due to osteoporosis and osteoarthritis.
- diminished elastic recoil and the collapse of supporting tissues around the airway causes a significant increase in RV. However TLC remains unchanged because the decreased chest wall compliance counterbalance increasing in lung compliance.
Restless leg syndrome
Clinical features:
-uncomfortable urge to move the legs with unpleasant sensation in the legs, onset with inactivity or at night, relief with movement (walking stretching ).
-causes:
Idiopathic, iron deficiency, uremia, diabetes
Treatment:
-avoidance of aggravating factors (alcohol, sleep deprivation)
-dopamine agonists (pramipexole).
Aspiration pneumonia develops
- develops in the most dependent portions of the lung.
- patients who aspirate while lying supine typically have involvement of the posterior segments of the upper lobes and the superior segments of the lower lobes.
- in addition the right main bronchus is more prone to aspiration that the left main bronchus and has a larger diameter, is shorter, and is more vertically oriented than the left main bronchus.
Dengue fever symptoms
2 types, classic and hemorrhagic fever
- Classic: flu like febrile illness with marked mylagia, and joint pains. Retro-orbital pain, rash.
- Dengue hemorrhagic fever: increased vascular permeability, thrombocytopenia, spontaneous bleeding —> shock, positive tourniquet test (petechiae after sphygmomanometer cuff inflation for 5 minutes)
Dengue fever features
Dengue viruses are transmitted by the aedes mosquito and are single stranded RNA viruses with 4 different serotypes (DENV1-4).
Corticosteroids changes on immune system
- Neutrophilia due to neutrophils demargination.
- Immunosupression
- Increase risk of infection
Pyruvate dehydrogenase deficiency
Inherited inborn error of metabolism often presenting in infancy with lactic acidosis and neurologic defects.
- the disease results from deficient activity of the pyruvate dehydrogenase complex, the lack of this enzyme leads to buildup of pyruvate which is shunted to lactate via lactate dehydrogenase generating lactic acidosis.
- disease managment involves the implementation of a ketogenic diet, high fat, and low carbohydate food with low levels of proteins.
- the diet forces the production of ketone bodies from fat and amino acid to fuel up the body in place of glucose.
- ketogenic amino acid metabolism generates the ketone body precursor actyl-CoA.
- lysine and leucine are exclusively ketogenic amino acids, they cant be metabolized to pyruvate and consumption will not lead to increased production of lactic acid.
Radical mastectomy, after few years violaceous nodules appear on arm
- chronic lymphedema is a risk factor for development of cutaneous angiosarcoma. This is usually post mastectomy with axilalry lymph nodes dissection complication.
- histologically, it shows infiltration of the dermis with slit like abnormal vascular spaces.
- prognosis for patients with angiosarcoma is poor because tumor is usually widespread by the time of diagnosis.
Dopamine features
Its an adrenergic agonist that have varying effects based on the dose. At lower doses, it stimulates D1 receptors in the renal vasculature and tubules, inducing increase in renal blood flow, glomelular filtration rate and sodium excretion.
- as the dosage increase, dopamine begins to stimulate ß1 adrenergic receptors in the heart increasing cardiac contractility, HR, and systolic BP.
- at the higher end of dose range (increase further more) stimulation of å1 receptors in systemic vasculature leads to generalized vasoconstriciton along with decrease cardiac output due to increase afterload.
Tuberous sclerosis
Autosomal dominant condition charactrized by cortical tubers and subependymal hamartomas in the brain.
- renal angiomyolipoma is a benign tumor, they are highly associated with this disease.
- cardiac rhabdomyomas, facial angiofibromas, and leaf shaped patches of skin lacking pigment can also occur (ash leaf patches)
ATN phases
3 phases
- Intitation phase corresponds with the original ischemic or toxic insult and last about 36 hours.
- Maintenance phase : tubular damage is fully established and patients commonly have oliguria, fluid overload and electrolyte abnormalities.it lasts 1-2 weeks until GFR stabilizes.
- Recovery phase: its charactrized by “re-epithelization” of the tubules. The GFR recovers relatively quickly as the tubules clear of casts and debris. However the tubular cells recover more gradually resulting in transient polyuria and loss of electrolytes due to impaired tubular resorption and decreased renal concentrating ability.
Neutric plaques
Another name for senile plaque found in Alzheimer diseae.
Acute intermittent porphyria treatment
The mainstay is to inhibit the whole heme synthesis process. Glucose or hemin inhibits ALA synthase and are used in AIP managment.
Measles virus clinical and complication
Clinical presentation:
-prodrome with cough, coryza, conjucivitis, fever, koplik spots.
-macupapular exanthem which spares the palms and soles and cephalocaudal spread.
Complication:
1. Primary measles pneumonia
2. Secondary bacterial infections (pneumonia or otitis media)
3. Neurologic (encephalitis, acute disseminated encephalomyelitis, subacute sclerosing panencephalitis ).
High frequency deep brain stimulation targeted to treat parkinson disease
- Nigrostriatal degeneration in Parkinson disease results in excessive excitation of the globus pallidus internus by the subthalamic nucleus which in turn cause excessive inhibition of the thalamus.
- reduced actiivity of the thalamus and its projection to the cortex consequently result in rigidity and bradykinesia.
- patients with medically intractable symptoms of parkinson disease may benefit from high frequency deep brain stimulation of the globus pallidus internus or subthalamic nucleus.
- high frequency stimulation inhibits firing of these nuclei. This causes increased activity in the downstream nuclei, resulting in thalamocortical disinhibition with improved mobility.
Alcohol related chronic pancreatitis
- its thought that alcohol related chronic pancreatitis develops in part due to alcohol induced secretion of protein rich fluid.
- these proteinaceous secretion can precipitate within the pancreatic ducts forming ductal plugs that may calcify and be detectable on abdominal imaging.
- ductal obstruction by such concretions may cause exocrine insufficiency due to atrophy of the pancreatic acinar cells and pancreatic fibrosis.
- pancreatic exocrine insufficiency leads to malabsorption with consequent diarrhea/steatorrhea.
- weight loss and bulky, frothy stools are typical clinical findings. This patients abdominal pain is most likely due to the pancreatitis itself.
Hives treatment
Hives are triggered in most cases by IgE dependent mast cell degranulation.
- as histamines is one of the primary mediators in this type of allergic reaction, antihistamines are the preferred treatment in most cases.
- loratidine and cetirizine are helpful
Pupil that dont react to light but do constrict with accomodation
Arhyll robertson pupils
Tabes dorsalis
What histological finding confirm irrevesible damage in the myocardium
-the appearance of vaculoes and phospholipid containing amorphous densities within mitochondria generally signifies irreversible injury, and implies a permanent inability to generate further ATP via oxidative phosphorylation. When the mitochondria are injured irreversibly the cell cannot recover. However simple mitochondrial injury can be associated with reversible damage.
Congeital hydrocephalus
Its caused by aqueductal stenosis and chiari malformation.
Symptoms include macrocephaly, bulging fontanelle, poor feeding, developmental delay, spasticity and hyperreflexia.
Mucle hypertonicity as well may arise (UMN symptoms)
Treatment include cerberal shunt
I-cell disease
AR disorder, lysosomal storage disease.
- it occurs due to defects in protein targeting, a process by which proteins are transported to their appropriate intra of extracellular location.
- post translational modification such as glycosylation and phosphorylation often function as markers that help guide the protein to its final destination.
- defective phosphotransferase enzyme causes extracelluar secretion of the proteins targeted for lysosomes, and accumulation of cellular debris in the lysosomes, forming characteristic inclusion bodies seen in I-cell disease.
- patient present with this disorder typically present with failure to thrive and cognitive deficits in the first year of life along with characteristic physical features (eg, coarse facial feature, corneal clouding).
Proteins targeted for lysosomes
Modified differently than those destined for extracellular secretion. A golgi body phosphotransferase enzyme catalyzes the phosphorylation of mannose residues on lysosome bound proteins, allowing them to traverse the golgi network and ultimately be transported to the lysosomes where they serve as catalysts for degredation of cellular components.
Cystitis pathophysiology in women
Pyleonephritis development
In women, sexual intercourse facilitates bacterial ascent by relatively short urethra and into the bladder which have several antibacterial defenses such as bladder mucosa that doesn’t allow bacterial attachment, urine flow , and normal urine is bactericidial with high urea content and osmolarity.
- when these mechanisms are disrupted or overcome due to bacterial virulence factors , cystitis occurs.
- frequent cystitis occurrence can weaken the veriscureteral valve leading to vesicuretral reflux —> pyelnophritis
High altitude changes
- hypobaric hypoxia —> low Po2
- hyperventilation in an attempt to improve oxygenation —> hypocapnia —> respiratory alkalosis.
- renal bicarbonate excretion compensate for alkalosis stabilizing the normal PH range within 48 hours.
Measles lead to what complication in the brain
Subacute sclerosing panecnephalitis
Pterion fracture
Fracture at the pterion (region where frontal, parietal temporal and sphenoid meet in the skull )
- the bone is thin and fracture there raise the risk for lacerating the middle meningeal artery and causing epidural hematoma.
- the middle meningeal artery is a branch of maxillary artery, which enters the skull at the foramen spinosum and supplies the dura mater and periosteum
Charcoal yeast extract medium
Supplemented with L-cysteine and iron (factor V,X) used for legionella pneumonia.
-its commonly contaminate natural bodies of water, municipal water supplies and water based cooling system found in commercial and hospital settings. Its frequent nosocomial sources of infection.
Identifying spinal cord level by picture
Moving rostally the amount of white matter steadily increase and section becomes more ovoid (particulary in upper thoracic and cervical regions).
Also the ventral horns of the lower cervical and lumbosacral regions are more prominent as these areas innervate the muscles of the arm and legs respectively.
Cavernous hemangioma complication
- they most commonly occur within the brain parynchema above cerbellar tentorium.
- patients often have seizures and may develop profressive neurologic deficits due to mass effect with interruption of cerberal microcirculation.
- these lesion have the tendency to bleed which can lead to intacerebellar hemorrhage.
S4
Its a sign of diastolic dysfunction, it occurs due to a sudden rise in EDV pressure caused by atrial contraction that has reached its elastic limit. It can be present in any condition that decrease ventricular compliance.
What is the fastest way to reverse warfarin effect
FFP which contain all of the coagulation factors unlike cryoprecipitates which contain only soluble proteins like factor VII , VwF and vitronectin.
Pulmonary hypertension due to LV HF
It begins with passive increase in capillary and arterial pulmonary secondary to pulmonary venous congestion.
-the high pressure —> endothelial damage -> capillary leakage of serum proteins into intestitium —> decreased production of NO and increased production of endothillin ->increased vascular tone —> over time remodeling occur with increased smooth muscle cell proliferation.
Antipsychotic side effects
- Extrapyramidal side effects:
- acute dystonic reaction : sudden onset sustained muscle contractions.
- akathisia: subjective restlessness with inability to sit still (can be treated with beta blockers or carbamazepine)
- drug induced parkinsonism: tremor, rigidity, bradykinesia, masked facies. - Tardive dyskinesia: involuntary movements after chronic use such as lip smacking and choreoathetoid movements.
- Neuroleptic malignant syndrome
Nitroprusside infusion can lead to what toxicity
Cyanide toxicity.
- cyanide is a potent mitochondrial toxin that binds to Fe3+ in cytochrome C oxidase, inhibiting ETC and halting aerobic respiration in the cell.
- its normally metabolized in the tissues by rhodanese, an enzyme that transfers a sulfur molecule to cyanide to form thiocyanate which is less toxic and excreted in the urine.
- cyanide overdose depletes the available sulfur donors, allowing cyanide to accumulate in toxic amounts.
- sodium thiosulfate works as antidote by providing additional sulfur groups for rhodanese, enhancing cyanide detoxification, its used in conjunction with hydroxocobolamin and sodium nitrite in management of cyanide toxicity.
Clinical manifestation of hemochromatosis include
- hepatomegaly (bronze diabetes )
- diabetes mellitus
- skin hyper-pigmentation (particularly in sun exposed areas)
myobacterium avium complex (MAC)infection
- MAC occurs in HIV patients with CD 4+ counts <50 cells/uL
- MAC typically present with the nonspecific symptoms of fever, weight loss , and diarrhea in an HIV + patients.
- MAC grows well at high temperatures and will exhibit optimum growth 41 C.
- MAC is resistant to many of the typical antimycobacterial drugs. As such, disseminated infection is treated with clarithromycin or azithromycin in combination with rifabutin or ethambutol.
- MAC can be prevented with weekly azithromycin at high risk HIV + pts.
