Week 8 Flashcards
1
Q
what effect can diabetes have on the GI?
A
In some cases of longstanding diabetes, the enteric nerves supplying the small intestine may be affected, leading to abnormal motility, secretion, or absorption. This leads to symptoms such as central abdominal pain, bloating, and diarrhea. Delayed emptying and stagnation of fluids in the small intestine may lead to bacterial overgrowth syndromes, resulting in diarrhea and abdominal pain.
Metclopropamide and cisapride may help to accelerate the passage of fluids through the small intestine, whereas broad-spectrum antibiotics will decrease bacterial levels.
2
Q
How to differentiate gout or pseudo gout with septic arthritis?
A
Obtain athrocentesis
gout - yellow, parallel, needle shaped
pseudogout - rhomboid, parallel is blue
*could see neutrophils from acute inflammation*
vs septic arthritis, likely to see culprit!
S. aureus, Strep or N. gonorrhea
3
Q
what area of the brain does the ACA supply?
Stroke here –>
A
anterior-medial surface (could see in a midsaggital cut)
lesion –> contralateral lower limb paralysis and loss of contralateral lower limb sensation
4
Q
viral particle with wheel like shaped?
What symptoms could this cause in a young child/infant?
A
double-stranded RNA, segmented, naked w/icosahedral capsid
Disease - #1 cause of severe infantile gastroenteritis that leads to watery diarrhea
5
Q
ABG metabolic ketoacidosis?
A
METABOLIC acidosis –> bicarbonate will be low
increased anion gap
INC H+ / hyperventalation will compensate (decreasing PCO2)
** insulin normally shifts potassium in - lack of, plus acidosis, shifts potassium out of cell –> hyperkalemia but depleted totaly body K+ ..and eventually will be lost in urine –> part of treatment includes giving potassium
6
Q
Recurrent vomiting ABG?
A
vomiting = expelling hydrogens –> metabolic ALKALOSIS
HCO3- INC
pH increased
Anion gap is normal
K+ decreased (in alkalosis, K+ shifts into the cells –> decreased K+)
7
Q
what are the calories per gram of fats, proteins and carbs?
A
fats: 9 calories/gram
proteins: 4 calories/gram
carbs: 4 calories/gram
alcohol: 7 calories/gram
*Calories = Kcal = 1000 calories
8
Q
What murmur could be described as brisk with a rapid fall?
A
aortic regurg
9
Q
leukocytes vs lymphocytes vs myeloid cells?
A
leukocytes = white blood cells (not RBCs)
Lymphocytes = T cells, B cells, Natural killers (part of innate)
Rest are myeloid origin - includes: of myeloblast origin:neutrophils, basophils, eosinophils, monocyte/macrophage
10
Q
Anestetics - what does it mean to have increased/decreased blood vs lipid solubility?
A
drugs with DECREASE solubility in BLOOD –>
rapid induction and rapid recovery
drugts with INCREASE solubility in LIPIDS–>
increase potency = 1/MAC (minimal alveolar concentration-in inhaled; amt required to prevent 50% of its subjects from moving in response to noxious stimuli)
11
Q
what is pseudocholinesterase?
A
glycoprotein enzyme made by the liver to hydrolyze/deactive exogenous choline esters
ppl with a defect in this enzyme have higher levels of succinylcholine –> neuromuscular blockade by succinylcholine neurmuscular blocks
provide artificial ventilation until pt wakes up; no further medical complications have been noted
12
Q
where are the most actively dividing cells in the GI found?
A
base of crypt
13
Q
Fluoroquinoloes (-floxicans) should not be taken with what other drugs?
A
do not take with anti-acids!
(aluminum hydroxide, calcium carbonate, magnesium hydroxide)
*Tetracyclines also should not be taken wtih milk, anti-acids or iron containing preparations because it will decrease the bioavailability of the drug in the gut
14
Q
polycystic kidney disease with clear kideny damaged ABG?
A
INC in BUN, INC in creatine, with a ratio <15 –> intrinsic renal failure –> metabolic acidosis
low pH and low bicarb
low PCO2 to compensate
15
Q
What marker should be used to monitor heparin?
an increase of tihs marker could be an indication of what?
A
use PTT (partial thrombinplastin time-intrinsic pathway)
Heparin induced thrombocytopenia (HIT) = development of IgG antibodies against heparin boudn platelet factor 4
Ig-heparin-PF4 complex activates platelets –> thrombosis and thrombocytopenia
16
Q
No neutrophils at infection site, yet enough in the blood + mulitple skin and mucosal infections?
A
LIkely to be leukocyte adhesion deficiency type 1 -defect in LFA1-integrin CD18 protein on phagocytes –> impaired migration and chemotaxis
Auto recessive
also associated with: absent pus formation, impaired wound healing and delay umbilical cord separation (>30days)
17
Q
person with hemochromatosis is at increased risk for what disease processes?
A
HCC
also results in HF and testicular atrophy
primary is autosomal recessive
secondary could be do to excessive transfusions
18
Q
Atelectasis-
what is it? what does it cause and what could precipitate it?
A
atelectasis = alveolar collapse –> bronchial obstruction
on lung exam: decreased breath sounds, dull to percussion, decreased fremitus, and if there is tracheal deviation, it wil be towards the affected side
causes:
- compression (usually an accumulation of fluid/blood/air that physically compress/collapse the adjacent lung) examples are pleural effusions from HF, typically reversible
- Resportion (when air is blocked from reaching the alveoli) examples are obstruction of bronchus by mucopurulent plug; typically reversible
- Contraction (occurs when local or generalized fibrotic changes in the lung/pleura hamper expansion and increase elastic recoil during expiration) example radiation therapy; typically irreversible
19
Q
fingershaped fibrovascular core with benign squamous cell epithelium on vocal cords or epligottis?
A
think HPV 6
20
Q
Dry tap?
A
think: aplastic anemia (hypocellular) or myelofibrosis (fibrotic)
myelofibrosis–> tear drop cells
=obliteration of bone marrow due to increase fibroblast activity in response to proliferation of monoclonal cell lines
see tear drop RBC and immature forms of the myeloid line (ie-nucleated erythrocytes)
often associated with massive splenomegaly
NOT associated with the philadelphia chromosome but in 30-50% of the cases with a JAK2 mutation
21
Q
left lower sternal border holosystolic murmur?
A
ventricular septal defect
22
Q
leukamoid reaction:
A
acute inflammatory response to infection
increase WBC with increase neutrophils and increase precursors such as band cells (left shift)
increase LAP (leukocyte alkaline phosphatase - in contrast to CML which as a decrease LAP)
23
Q
melanoma - what affects its prognosis?
A
significant risk for metastasis
DEPTH correlates with risk
24
Q
pulmonary hypertension is mostly idipathic but can be secondary to..
A
fibrosis
fibrosis –> deoxygenation –> vasoconstriction via endothelin-1
tx: bosentan (endothelin-1 antagoinst –> decreasing vascular resistance), PDE inhibitors, prostaglandin analogs (PGI1 - epoprestinol, iloprost)
*pulmonary sclerosis is the most common cause of death in people with scleroderma*
25
Overview of MS pahtogen:
Autoimmune with destruction of oligodendrocytes
hypersensitivity reaction type IV
thought of CD4+ T activated by myelin basic protein
related with HLA-DR2
26
What HTN drug should be avoided in bilateral renal stenosis
ACE inhibitors (-prils)
it can increase the progression to renal failure by further decreasing GFR
one of the tale-tell sign of renal stenosis when PT has high blood pressure with INC renin and INC aldosterone; hypokalemia and metabolic alkalosis+ giving ACE inhibitor further increases serum renin!
27
Olser-Weber-Rendu syndrome-
clinical presentations:
aka: hereditary hemorrhagic telangiectasia
Autosomal Dominant
*inherited blood disorder of blood vessels*
branching skin lesions (telangiectasias), reccurent epistaxis, skin discoloration, AV malformations, GI bleeding and hematuria
pulmonary AV shunting --\> shortness of breath
28
Drug-induced interstitial nephritis:
presentation
causative agents
=tubulointerstitial nephritis
pyuria, often with eosinophils and azotemia occuring after administration of drugs that act as haptens --\> hypersensitivity
associated with: fever, joint pain, rash, CVA tenderness, hematuria (or could be asymptomatic)
biopsy: inflammatory infiltrates
Nephritis occurs 1-2 weeks after certain drugs: diuretics, penicillin derivatives, PPI, sulfonamides, rifampin
but can occur months after NSAID use
29
underventilated but well perfused area of lung --\>?
physiologic shunt
30
which vibrio could cause cellulitis?
vibrio vulfinuclus
31
factor that leads to vasoconstriction in the lungs with lack of ventilation?
Endothelin-1
Bosetan = endothelin antagonist, used in pulmonary hypertension
32
what is the result and cause of glycogen deficiency in the vaginal epithelium
glycogen deficiency can result from estrogen due to premature ovarian failure or menopause
this results in --\> flattening of the labial folds and vaginal rugage which can cause dyspareuria
33
How do RBC accomodate for low blood oxygenation levels?
RBCs don't have a mitochondria thus can't produce tons of ATP via the citric acid cycle
BUT they have the enzyme **bisphosphoglycerate mutase** which is able to **convert 1,3 bisphos to 2,3 bisphos**; this step *_bypasses the ATP-generating step of glycolysis_*
*_this increases in hypoxia and chronic anemia_*
2,3-BPG allosterically decreases hemoglobins affinity for oxygen thus increasing oxygen delivery at the periphery
34
what contributes to slow phase 4 of cardiac pacemaker cells:
what drugs prolong phase 4?
- closure of K+ channels
- slow inward Na2+ flow through funny channels
- opening of T-type Ca2+ channels
Acetycholine and adenosine prolong phase 4, reducing the rate of spontaenous deoplarization in cardiac pacemaker cells
35
what is the major determinant of symptom severity in pt with tetrology of fallot?
the degree of right ventricular outflow obstruction, determines how much deoxygenated blood is delievered to the systemic system, thus determing the degree of right to left intracardiac shunting and cynosis
note- the degree of RVOT obstruction is dynamic and can increase sudenly --\> cyanosis / tet spells
can be triggered by: hyperventilation, dehydration, idiopathic
36
what type of trauma is common with posterior and anterior urethral injuries in men?
mgmt?
Posterior urethra includes the prostate and mebraneous segment; the membraneous segment is more likely to be injured due to its lack of surrounding supporting tissue
-- pelvic injury
anterior urethra includes the bulbous and penile segment;
-- straddle injuries
if urtheraly injury is suspected, foley is contraindicated as it may worsen the injury; do a retrograde urethrogram to assess injury
37
where is the center related to acute nausea post chemotherapy?
stimulation of the chemoreceptor trigger zone, which lies in the area postrema of the dorsal medulla near the 4th ventricle
this area received blood from fenestrated blood vessels / no BBB thus allowing it to sample chemicals circulating in the blood
38
Name the function of RB:
one of the regulators of the G1 --\> S transition
active RB = HYPOphosphorylated (ie- resting cells in Go phase)
inactive RB = HYPERphosphorylated
when the cell is stimulated by growth factor, activation of cyclin D, cyclin E and the corresponding cyclin kinases 4 and 6, occur --\> hyperphosphorylation of the RB protein = inactivation --\> release of E2F transcription factor allowing the cell to progressin from G1 --\> S
if RB is active (hypophosphorylated) in binds to E2F stopping the transcription of genes necessary for G1 --\> S thus cell division
39
what is p27?
cell cycle **inhibitor**
acts during **G1 phase** by inhibiting cyclin-dependent kinases
normal tissue contains high levels of p27 while malignant tissues contain low levels
40
where does meningitis colonize?
mucosal epithelium of the nasal pharynx
transmission is droplet or direct contact with respiratory secretions
colonize via pilus mediated adhesionso the mucolsa epithelium --\> invade --\> gain access to the vasculature where they spread hemotogenously
recombo between silent and expressed pili genes --\> antigenic variation that makes vaccines difficult to target
also have an IgA protease that inhibits mucosal antibodies
41
Diffuse esophageal spasms (DES)
pathogen
sx
imaging
Most likely nvolved impaired inhibitory neurotransmission within the esophageal myenteric plexus --\> inappropriate contraction of the esophagus --\> disorganized non-peristaltic contractions
sx: food bolus is inefficiently propelled towards the stomach --\> intermitten solid/liquid dysphagia, chest pain, heartburn, food regur
monometry shos disorganized non-peristaltic contractions
corkscrew esophagus on barium esophagroam
42
mgmt of febrile seizures
acetaminophen or ibuprofen for comfort
most common neurologic disorder affecting children
rf: high temps, family hx
exclude CNS infections
minimally increase risk of developing nonfebrile seizures
use: antipyrecs can dec fever and improve pt comfort by inhibiting prostaglandin synthesis; decrease **prostaglandin E2 --\> r*educe thermoregulatory set* point in the _hypothalamus_, thus lowering body temp**
do not prevent future sezures though!
43
With which of the congenital adrenal hyperplasia would a pt have increase bp?
11b- hydroxylase (due to weak mineralcorticoid of 11- deoxycorticosterone) w/ ambiguous genitalia in females
17a- hydroxylase (increased aldosterone production)
all pt phenotypically female; affected individuals do not undergo puberty (no sex steroids), develop hypertension, hypokalemia
44
what are common initial symptoms of MS?
Manifest with various self-limiting neurological sx, usually in pt 20-30 y/o
most common initial sx: optic neuritis, internuclear opthalmoplegia, sensory deficits
**\*symptoms usually worsen with heat exposure** (hot shower, streneous activity) --\> fatigue; due to decreased axonal transmission associated with increased heat, also may lead to episodes of worsening neurological deficits
affected areas demonstrate myelin breakdown/demyelinaiton
chronic demyelinating dx affecting the white matter of CNS
45
NK Cells:
- derived from **lyphoid** stem cells
~10% of lymphocytes circulating
large cells with cytoplasmic granules containing perforins, granzymes --\> apoptosis
Do not directly lyse cells
**responsible for destruction of cells with decreased or absetn MHC class I on their surface**
**CD 16 or CD56**
do not req. thymus for maturation; found in athymic pt
have no antigen-specific activitys; dont req antigen for activation and do not ahve memory ability
**activated by interferon-gamma, IL12**
46
Benzos vs barbituates
Benzos - increase FREQUENCY of chloride channel opening
Barbs - increase DURATION of chloride channel openning
47
N gonorrhea tx?
must treat for both N gonorrrhoeae and Chlamydia trachomatis
N. gonorrhea: ceftriaxone
C. trachomatis: doxycycline or azithromycin (macrolide - erythromycin
48
how does chronic rejection affect the lungs?
\*\*rejection of lung transplant differs from rejection of an intra-abdominal organ-which is primary vascular obliteration\*\*
In lung transplant, the immune system affects the small airways --\> inflammation of the small bronchiles= bronchiolitis obliterans syndrome
-inflammation and fibrosis of the bronchiolar wall --\> narrowing and obstruction of the affected bronchioli
\*major cause of mortality in lung transplantation
sx: dyspnea and wheezing
note: pulmonary and bronchial vessels are the main targets of acute rejection- perivascular infiltration with lymphocytes, macrophages, plasma cells is characteristic
49
primary platelete problem
+ megakaryocytes??
immune thrombocytopenia
antibodies directed against G11b/IIIa
--\> splenic macrophage consumption of the immune complex
commonly due to viral illness
Labs: megakaryocytes
Tx: steroids, IVIG, splenectomy for refractory
50
increase in hydrostatic pressure in bowman's space?
something beyond the bowman's capsule that is pushing up pressure...
ie) BPH
51
When a renal artery is blocked, what are the effects?
renal is not being perfused and is not filtering --\>
blood pressure is going to increase (depends how much the other kidney is working)
The affected kidney is not "sensing" that blood is coming through / sense "low blood pressure" --\> activate the RAAS system --\> increased renin, increased aldosterone --\> greater increase to the bp, total peripheral pressure is increased
(think of this case with low renal perfusion from stenosis or fibromuscular dysplasia, CHF, ect..)
52
chronic gastritis --\>
mucosal inflammation often leading to atrophy, (hypochlorydia --\> hypergastrinemia) intestinal metaplasia, hyperplasia of enterochromaffin cells
increase risk for cancer
53
4 day old boy
lathargy, fatigue
vomiting after being breastfed
high sodium
high 17-hydroxyprogesterone
enzyme deficiency?
21 hydroxylase
XX virilization, salt wasting, most common
note: only one with elevated potassium, only one with elevated 17 hydroxyprogesterone, only one with decrease in BP
54
Vitamin B9 deficiency
AKA: Folate
increasingly seen in alcoholics and pregnant women
-macrocytic, megaloblastic anemia
hypersegmented PMNs
No neuro symptoms (opposed to B12 vit deficiency)
glossitis
increased homocystein, NL methylmalonic acid
(opposed to B12 deficiency - increased both)
55
Legionella pneumonia
serious pneumonia
gram negative rod/bacilli
hard to gram stain - regquires silver stain to visualize; growth requires presence of cystein and iron; could grow on charcol yeast agar, urine antigen test for rapid analysis
could present with: hyponatremia, diarrhea, fever, confusion
tx: macrolides, fluoroquinolone
acquired from inhalation of aerosols from environmental source (esp contaminated aresolized water -, water jets, sprays, A/C units)
NO direct human to human transmission
56
which drugs are more commonly associated with reprerfusion arrhythmia?
Fibrinolytics
tPA, streptokinase, retelplase, tenecteplace
57
what is the origin of keratin markers?
epithelial origin
Keratin is an intermediate filament
58
Bulimia nervosa vs binge eating?
Bulimia nervosa is eating with compensatory actions (purging or restrictive behavior) to prevent weight gain; excessive worrying about wt, but normal BMI/wt to overweight; distorted views of body
anorexia nervosa - underweight, thinking they are fat, intense fear to gain weight
vs
Binge-eating - no compensatory actions, lacks self-control
59
C. perfringes toxin
alpha toxin / phospholipase C
=Lecithanase
concentration correlated with lethal and necrotic effects
catalyzes the splitting of phospholipid molecules, degrading lecthin --\> membrane distruction, cell death and widespread necrosis
60
what biochemical process could be defective in pt with alzheimers or parkinsons / other neurological diseases?
ubiquitin-pathway
ubiquin is a protein that is ATP-depent attached to other proteins and marks them for dedegration via the ubiquitin-proteosome system
**parkinson genetics - parkin, PINK1, DJ1**
61
what CNS tumors are considered gliomas and what do they stain positive for?
astrocytomas, olidendrocytoma, eppedymomas
Stain for GFAP (glial fibrillary acidic protein)
62
CNS tumor staining positive for synaptophysin, indicates what origin?
neurons
synaptophysin is a transmembrane protein found on the presynapic vessels of neurons, neuroectoderm and neuroendoderm cells
63
what type of murmur is associated with ASD?
wide and fixed splitting of S2
64
how can you distinguish between homocystinuria (w/marfanoid body habitus) vs marfan syndrome?
**homocystinuria**, you'll see *_intellectual disability_*, and increase propensity for thrombotic events, downard lens dislocation, autosomal recessive, megaloblastic anemia, fair skin
**Marfan** - upward lens dislocation, autosomal dominant
65
what lab findings is expected with spherocytosis
anemia, reticulocytes, increased indirect bilirubin (indicative of hemolytic anemia)
decreased haptoglobin, RBC without central pallor, elevated **MCHC** (due to membrane loss, and slight dehdration; most specific red cell marker indicative of spherocytosis), increased LDH
spherocytosis is caused by defective binding of the cytoskeleton to the plasma membrane due to mutation in **ankyrin**, **band 3** or **spectrin proteins**
66
What are the labs associated with pre-renal azotemia?
due to decrease in RBF (hypotension) --\> kidney tries to maintain GFR, increasing absorbing BUN, creatinine is not
FeNA \<1%
Increased BUN/Cr ratio
67
what are enteroendocrine cells of the GI?
cells that produce endocrine hormones that regulate GI function
include: I, K, L, G, N, enterochromaffin cell, S cell in the intestines
G cells and enterochromaffin like cells in stomach
alpha and beta cells of the pancreas
68
Parinaud syndrome
paralysis of conjugate vertical gaze due to injury of the superior colliculus
could be due to a stroke, pinealoma (sits above the superior colliculus, hydrocephalus - below the superior colliculus and inferior colliculus is the 4th ventricle, thus if there is obstruction above, you could see enlargement of the 3rd and lateral ventricles
69
which tumor is associated with opsoclonus-myoclonus syndrome?
= non-rhythmic eye movements + myoclonus
In youn children, it is associated with paraneoplastic sydnrome associated with **neuroblastoma** (of the **adrena medulla**)
increased copies of N-myc
most common extracranial tumor in children
70
external laryngeal nerve
fxn:
terminal brach of superior laryngeal nerve (branch of vagus)
supplies the criocothyroid muscle
fxn: varies the length and tension of the vocal cords
injury --\> monotone voice
(vs injury to recurrent laryngeal --\> hoarseness)
71
what are the two types of sweat glands and what are they innervated by?
apocrine and eccrine
apocrine - secrete only oils, stimulated by catecholamines; greater at axillary, areolar, genitals and anus - become active after puberty
eccrine - secrete watery substance, secreted by the sympathetic NS and serve a thermoregulatory function; all over skin, greater and palms and soles
72
cavernous hemangiomas-
vascular malformations that typically occur within the brain parenchyma above the cerebellar tentorium (sporadic or familiar)
consist mainly of dilated, thin-walled capillaries with little to no intervening nerve tissue
tend to bleed, ppl to tend to experience seizures due to mass effect and other neurological deficits
increased risk for **intracerebral hemorrhage** and **seizures**
73
How do you differentiate a pt experiencing DIC vs TTP/HUS syndrome??
DIC - massive activation of the entire coagulation cascade, because platelets are being used --\> increased risk for bleeding; PT and PTT are prolonged, low fibrinogen and increased fibrin dedegration products especially dimer proteins, decreased factor V and VIII; schistocytes
exposure to procoagulants initiates intravascular thrombosis, which is then followed by thrombolysis
TTP/HUS - increase platelet adhesions --\> increased aggregation --\> thrombosis
usually no bleeding; only platelets activated
normal PT, PTT, normal fibrinogen
74
Vitamin E deficiency:
what cells are highly susceptible?
what are clinical manifestations?
what is susceptible to having vitamin E deficiency?
Vitamin E is important to help protect fatty acid from oxidation, thus deficiency predisposes cell membranes to oxidative injury
Cells highly predisposed to vitamin E deficiency are neurons with long axons (because of the high surface area) and RBC (due to the high exposure to oxygen)
_Clinical manifestations:_ **neuromuscular disease** - *spincerebellar ataxia, polyneuropathy, skeletal myopathy --\> _ataxia, impaired proprioception, impaired vibratory sensation_* (sx similar to subacute combined degeneration) and **_hemolytic anemia_**
Susceptible population: ppl with fat malabsorption- CF patients, pancreatic insufficiency..etc.
75
What does the lesser omentum consist of?
The lesser omentum is a double layer of peritoneum that extends from the liver to the lesser curvature of the stomach and the duodenum
it consists of 2 ligaments:
1) hepatogastric / gastrohepatic - contains the gastric arteries, separates the greater and lesser omentum on the right - may be cut to access the lesser sac
2) hepatodudodenum (where the portal triad is connected), borders to omental foramen which lies between the greater and lesser omentum; compressing the ligament at the omental foramen --\> pringle maneavuer - could control bleeding of the triad here)
76
What retinal damages could severe hypertesion manifest as?
1. **dot or flamed shaped hemorrhages** - severe hemorrhage at rentinal precapillar arterioles --\> endothelial disruption --\> leakage of plasma into capillaries --\> fibrinoid necrosis --\> necrotic vessles bleed into nerve fiber layers --\> flamed shaped hemorrhages
2. **cotton-wool spots** - white foci of retinal ischemia
3. **Copper / wiring** - thickening of arteriolar walls
4. **AV malformations** - compression of associated veins
77
What is one sign of minimal change disease?
Selective loss of albumin (proteinura, with high albumin loss vs other proteins)
due to **immune dysregulation** --\> increased production of glomerular permeability factor --\> **damage of podocyte (foot process effacement and fusion**) and **loss of anionic** feature of glomeural basement membrane
--\> contributes to hypoalbuminemia and generalized edema
\*\*light microscopy and IF show NORMAL kidney
**\*\*selective loss of foot processes can _ONLY be detected via EM!_**
Most common neprhotic syndrome in young children (2-6 y/o)
associted with **respiratory**, **immunization** and **atopic disorders** with *_good response to glucocorticoids_*
78
Leuprolide MOA
GnRH agonist
If given continuously, has an initial increase in the production of testosterone via increased LH (--\> stimulates the leydig cells), but prolong use --\> suppression of LH release and susequently testosterone fall (DHT follows the same concentration pattern as testosterone)
79
Chiari Malformations
describe the 2 types and typical manifestations
**congenital disorder** --\> underdevelopment of posterior fossa
--\> cerebellum and part of medulla to herniate through the foramen magnum
**Type 1:** most **common**, and more **benign** that doesn't present until **late adolescences/early adulthood** with increasing **occipital headaches** (due to meningeal irritaiton) and **cerebellar dysfunction** (ataxia, dizziness) due to compression of cerebellar tonsils
**Type 2: Arnold-Chiari malformation**, more severe, typically evident during neonatal period
downward displacement of cerebellar (tonsils and vermis) and medulla through the foramen --\> non-communicating hydrocephalus, mostly at the adequate stenosis
medulla compression -\> stridor, dysphagia and apnea
associated wtih lumbar myelomeningocele, which causes lower extremity paralysis
80
what is the difference between unfractionated heparin and low molecular weight heparin?
both can bind antithrombin to increase its activity againts factor Xa
Only unfractionated heparin though can bind both antithrombin AND thrombin, to allow antithrombin to inactivate thrombin, via its longer polypeptide chain
thus equal activity against Xa and anti-thrombin
vs: LMWH has greater affinity for Xa vs anti-thrombin due to is smaller polypeptide chain and inability to bind anti-thrombin as great.
81
best way to manage somatic symptom disease?
best managed with regular visits instead of extensive and unnecessary tests, referals to specialist (especially to psychiatrist at the beginning of the pt-physician relation because they may feel as you are dismissing their symtopms/feeligns)
82
How do sporadic, familia and HPCC colorectal cancer arise?
**Most cases of sporadic** and **all cases of familial adenomatous polyposis**, arise via the adenoma to carcinoma sequence
**APC (inac) --\> Kras (act) --\> DCC (inact) --\> p53 (inact)**
**Microsatalite instability pathway,** due to mutations in the DNA mismatch repair genes, highly seen in **HNCC/Lynch syndrome** (associated with: **MLH1, MSH2, MSH6, PMS2**) - other family members have cancers, increased cancer in first-degree family members; due to one inherited mutation + one more mutation occuring in adulthood
**CRC due to IBD**, *_is more often associated with early p53 mutations and late APC- huge contrast to the other forms of CRC formation,_* multifocal in nature, and higher histoloical grade
83
Systemic scleroderma could cause esophageal dysmotility; what is the pathogenesis under this feature of CREST?
what are these patients at increased risk of?
Recall that CREST is limited to the skin predominately the face, forearms and fingers
pathogenesis involves: **chronic autoimmune inflammation** --\> vascular **endothelial injury** --\> chronic ischemic tissue damage (ie-finger tip ulcers) --\> excessive **activation of fibroblast** --\> excessive and progressive **tissue fibrosis**
**Esophageal dysmotility** is due to atrophy and fibrosis replacement of the muscularis layer of the lower esophagus
could result in atonia and dilation of the lower esophageal tube and sphincter, which could present as symptoms of GERD
Predisposes pt to **barretts esophagu**s and **fibrous stricture formation**
84
Type II DM with acanthosis nigrans is a sign of insulin resistance.
What additional disease state could contribute to insulin resistance?
Obesity, sedentary lifestyle and increased free fatty acids contribute to insulin resistance.
In normal cells, insulin has **anti-lipolytic** effects in adipose tissue. Thus, in insulin resistance tissue, this effect of insulin is **blocked** --\> **increase lipolysis and the release of free fatty acids**
Free fatty acids further perpetuates insulin resistance by **impairing insulin-dependence glucose uptake** and **increasing hepatic gluconeogenesis**
85
Causes of pigmented stones
Brown - usually associated to biliary tract infection (esp anaerobe microbes with b-glucuronidase)
Black - usually associated with chronic chemolysis (SCD, b-thalasemia, hereditary spheryocytosis) and increased enterohepatic cycling of bilirubin (ileal diseae)
--\>increased amoun of unconjugated biliruib --\> precipatation of calcium bilirubinate --\> radiopaque (you can see on x-ray!)
86
which hepatitis viral infection can integrate into host genome?
HBV although a partial dsDNA virus, it can integrate into the host genome with its reverse transcriptase
allows for continual transcription of host oncogenic genes, such as HBx --\> disrupts cell cycle control by activating multiple growth-promoting genes and inactivating P53
HCV does not integrate into host genome
87
what is the pathological lesion of malignant hypertension?
onion-like concentric thickening of arteriolar walls in the renal vascular (further perpetuating HTN via RAAS) and elsewhere
due to persistent dyastolic pressure exceeding \>130 mmHg often associated with acute vascular damage
this is a result of laminated smooth muscle cells and reduplicated basement membranes
nephrosclerosis, retinal hemorrhages, exudates or papiledema, hypertensive encephalopathy
88
Mockenberg sclerosis
typically occur to ppl \>50
form of arteriosclerosis characterized by calcification of the medial layer of muscular arteries --\> medial-band calcification
though to cause isolated systolic hypertension due to arterial hardening
asymptomatic
could be see in xray
89
carcinoembryonic antigen
what is its importance?
glycoprotein associated with cell adhesion
CEA typically produced by embryonic pancreas, liver and intestines and detectable in trace amts in adults
levels are increased in most pts with colorectal ca (and other malignancies and diseases)
NOT used for diagnosis
used for the detection of residual disease after surgery and recurrence
initial high leves when CRC is detected is associated with worse prognosis and failure to normalize post surgery - but low sensitivity and specificity not good for initial screening or diagnosis/prognosis of pt
90
What are the signs of bladder outlet obstruction?
straining with urination, could lead to incomplete feeling of bladder emptying and could cause overflow incontinence
in elderly men most common due to BPH --\> increased pressure of the urinary tract
- bladder wall hypertrophies
- ureter, renal calyces and renal pelvis dilate and deform leading to hydronephrosis
- renal parenchyma becomes atrophic and scarred due to continual reflux of urine and damage of renal tissue
91
where is airway resistance the greatest and the least within the respiratory tract?
Overall, upper airway resistance (nasal passages, mouth, larynx, pharynx) accounts for about 50% of total airway resistance
trachea and main stem restistance high but
greatest in the middle sized bronchi (2nd - 5th generation include segmental bronchi)
highly turbulent airflow
least in terminal bronchioles due to increased summated cross-sectional area of all the bronchioles icreases greatly --\> slowed velocity and thus low-resistance laminar flow prefered for gas exchange
92
What is the histological finding in Reyes disease?
syndrome occurs in children with febrile illness due to the use of salicylates (aspirin)
consists of hepatic dysfunction due to mitochondrial damage and hepatic encephalopathy (due to hepatic dysfunction and hyperammonemia)
NO inflammation NO cerebral edema
Light microscopy: microvascular steatosis, with small fat vacuoles in the hepatocytes
Electron microscopy: swelling, decreased # of mitochondria and glycogen deposition
93
SCD genetic mutation?
point mutation in the 6th codon of the beta-globin gene that causes the substituation of valine (hydrophobic) for glutamic acid (hydrophilic)
this change, causes the hb to polymerize at low oxygen levels --\> sickling and hemolysis --\> vascular occlusion
94
cricothyroid membrane...
between the thyroid cartilage and the cricothyroid membrane
For a cricothyromitry, you cut through:
skin, superficial cervical fascia (including fat and patysma muscle), investing and pretracheal layers of the deep cervical fascia (not the prevertebral layer!!) + cricothyroid membrane
95
In a myocyte action potential, what causes the upstroke?
voltage gated sodium channels
tetrodotoxin and saxitoxin (red tide) binds to the Na+ channels, inhibiting sodium influx and preventing action potential and conduction
96
cerebral amyloid angiopathy
**amyloid angiopathy** is a consequence of B-amyloid deposition in the walls of small and medium sized blood vessels --\> vessel weakening and predisposition to rupture
most common cause of spontaneous lobar hemorrhage, esp in adults \>60 years old
Recurrent hemorrhages, esp in the occipital and parietal lobes
VS **charcot-bouchard aneurysms** - rupture is usually due to chronic hypertension, and typically causes hemorrhages in the deep structures of the brain such as (basal ganglia, cerebellar nuclei, thalamus and pons)
97
what are current alzheimer specific therapies?
cholinesterase inhibitors
antioxidants (vitamin E)
NMDA receptor antagonist (memantine)
98
curling vs cushing ulcers?
Curling are due to shock, trauma, burns, physiological stress...
--\> hypovolemia and hypotension, splanchnic vasoconstriction --\> local ischemia --\> decrease mucosal protection --\> erosion/ulcer formaiton esp at duodenum
Cushing are due to elevated intracranial pressure/disease --\> vagal stimulation via increased acetylcholine release --\> increase H+ --\> erosion/ulcer formation, esp at stomach, esophagus or duodenum
99
fever, rash, acute renal failure after starting new med (possible b-lactam, diuretics, proton-pump inhibitor, sulfonamides, rifampin, NSAIDS)...
indicative of acute interstitial nephritis
(thought to be mediated by IgE-mediated hypersensitivity or cell mediated reaction type IV depending on the drug)
primarily involved renal interstitium, causing interstitial edema and leukocyte infiltration -- commonly infiltrate the tubular epithelium and granuloma formation may be observed.
increased eosinophils, IgE,
100
what are the possible deficiencys that could cause subacute combined degeneration?
vitamin B12 def, copper deficiency, vitamin E def, HIV
**SCD -**
**S**pinocerebellar tract
lateral **C**orticospinal tract
**D**orsal columns
101
what is the method of VRE resistance?
**substitution of D-lactate in place of D-alanine** during the process of peptidoglycan cell wall synthesis, preventing vanco from binding to its usual **D-alanyl-D-alanine**
102
Cerebellar injuries
fxn: motor planning and coordination of **ipsilateral**
*_Cerebellar hemisphere_* impt for extremeties via lateral descending motor systems (lateral corticospinal tract and rubrospinal tract)
*_Cerebellar vermis_* impt for trunal coordination via connections to medial descending motor tracts (ant corticospinal, reticulospinal, vestibularspinal, tectospinal)
Lesions show ipsilateral defects:
**@ cerebellar hemisphere** --\> dysdiadochokinesia (impaired rapid alternating movements), limb dysmetria (overshoot or undershoot during targeted movement), intent tremor (tremor during targeted movement)
@ cerebellar vermis --\> trucal ataxia, vertigo and nystagmus could also occur due to inferior vermis connection to floculonodular node
103
Presentation of idiopathic pulmonary fibrosis:
restrictive profile on PFT
CT - patchy involvement with dense fibrosis,
alveolar wall collapses --\> cystic sapces (honeycomb appearance), lined with pneumocytes II or bronchiolar epithelium (honeycomb fibrosis)
\> subpleural and paraseptal spaces
104
co-factor impt for transanimation reactions?
Vitamin B6 (pyridoxal phosphate)
transanimation reaction: typically occurs between an animo acid and an alpha-keto group
the amino group from the amino acid is transfered to the alpha-keto group which then becomes an amino acid.
Vitamin B6 impt for transanimation and decarboxylation reactions
105
which drugs used for DM II, increase the insulin secretion via oral intake?
sulfonylureas (ie- glyburide) and meglitinides
incrase secretion of insulin from pancreatic B-cells
106
what are some complications of nephrotic syndrome?
hypercoagulable state due to loss of Anti-thrombin III in urine
increased risk for infection due to loss of immunoglobulins
107
why is the left renal vein more susceptible to varicole?
The left gonadal vein empties into the left renal vein, which crosses over the aorta to empty in the IVC
The left renal vein can get compressed in-between the SMA and aorta --\> increasing back pressure to the left renal vein, and left gonadal vein --\> dilation of the left pampiniform plexus = varicocele
\*\*difference in venous drainage gives diagnositic significance to isolated right vericocele - can indicate IVC occlusion by malignant tumor or thrombus
108
Arsenic poisoning:
Arsenic binds to sulfhydryl groups --\> impaired cellular respiration via **inhibition of pyruvate dehydrogenase, disruption of gluconeogenesis, gluthianone metabolism**
\*\*N,V,D hypotension, QTc innervation,
109
Clinical presentation of scabies:
highly contagious
highly puritic rash, worse at night, in the flexor surfaces of the wrist, lateral surface of the finger and finger webs
exoriations with small crusted red papules around affected area
dx: skin scrappings that show mites, ova and feces under microscopic light
110
complications of hereditary spherocytosis?
hereditary spherocytosis is the most common hemolytic anemia, due to RBC membrane defect most often on spectrin or akyrin (plasma-membrane scaffolding proteins)
increased osmotic fragility test
aplastic anemia from parvovirus B18 infection
pigmented gallstones
111
glucokinase vs hexokinase
enzyme in the first step of glycolysis (and glycogenesis in the liver)
**glucokinase** is only found in the liver and pancreatic B cells; **induced by insulin**
\*mutation associated with *_maturity onset diabetes of the young_*
**high Km, high Vmax/high capacity**
not inhibited by g-6-p, inhibited by fructose-6-p
Hexokinase is found in all cells except the liver and pancreatic B cells; **NOT induced** by insulin
low Km, low Vmax/low capacity, neg feedback by G-6-p
\*at LOW glucose concentrations - hexokinase sequesters glucose in the tissue
at HIGH glucose conc - glucokinase stores glucose in the liver
112
glycolytic enzyme deficiency presentation?
typically presents as hemolytic anemia as RBC rely compeltely on anaerobic glycolysis for energy production
113
what is the role of histones in DNA?
8 histones (2X H2A, H2B, H3, H4) = histone core, positively charged
histone core + DNA (neg charged) --\> nucleosome
Nucleosome is kept tight with Histone 1 - bind the linker DNA segments
114
how to distinguis graft T-cell sensitivity rxn vs host T-cell sensitivity rxn?
**Host reponse** --\> graft failure without much of a full systemic response
vs
**Graft response** --\> Skin (rash), liver and GI are most often organs affected
115
Amaurosis fugax?
painless, transient, monocular vision loss due to small embolus to the **opthalmic artery**; usually doesn't last more than a few seconds
116
acalculous cholecystitis?
acute inflammation of the gallbladder in absence of gallstones
typically occurs in critically ill patients due to sepsis, etc--\> stasis and ischemia
clinical signs may be subtle with some RUQ abdominal pain, leukocytosis and fever
diagnostic: ultrasound (showing edematous and enlarged GB)
high mortality
117
what antibiotics should be used for anerobic infections?
*_Rule of thumb_*
Above the diaphragm: clindamycin
Below the diaphgram: metronidazole
118
class I anti-arrythmics:
inhibition of phase 0?
effect on length of action potential?
Inhibition: IC (use-dependent!) \> IA \> IB
effect on AP:
1A - prolongs
IB - shortens
IC - no change but prolong qrs.
119
leukamoid reaction:
acute inflammatory response to infection, other
inc WBC, inc neutrophils, increase bands cells
**INC leukocyte alkaline phosphatase** (contrast to CML that has increase wbc, with increase immature neutrophils but dec LAP)
\*early mature neutrophil precurors with inclusions (dohle bodies)
120
what is the effect of V2 stimulation in the kidney/
vasopressin (V1 and V2) and desmopressin (V2) --\>
receptor mediated increase in water and urea permeability at the inner medullary collecting duct --\>
resulting rise in urea reabsorption/decrease clearance results in maximally concentrated medullary osmotic gradient --\> production of maximally concentrated urine
121
Why are infants low on vitamin K?
- poor stores due to poor transplacental transfer
- immature gut biota
- breast milk (if breast fed exclusively) are low on vitamin K
- refusal for prophylaxic vitamin K shot
- liver are unable to use it efficiently
- if pt with CF, risk for malabsorption
sx: increase bleeding
122
organ susceptibility to infarction:
CNS \> myocardium\> kidney \> spleen \> liver (dual artery + tons of collaterals)
123
treatment of choice for lung abscesses?
want to ensure you are covering gram + (stre pneumo most common cause of lung infection) but also oral anaerobic organisms since many times lung abscesses are polymicrobial.
clindamycin and macrolides
124
what is livedo reticularis a tale-tell sign of?
swelling of venules due to an underlying obstruction (anything that can cause an obstruction, embolism, vasculities...)
125
where could we see vitamin E deficiency?
sx?
rare, but could occur in pt with fat malabsorption and abetalipoprotenemia
most notable sx: hemolysis and neurological dysfunction (mimic friedrick ataxia!! and similar to vitamin B12 deficiency too!)
ataxia, loss of proprioception and vibration, and loss of deep tendon reflexes
126
mutation involved in melanoma?
BRAF (valine --\> glutamic acid)
protein kinase involved in melanocyte proliferation (mutation --\> NRAS independent and uncontrlled BRAF)
127
IgE independent vs IgE depedent mast cell degranulation?
IgE independent is often associated with certain medications including: opiods, radiocontrast agents, some antibiotics (vancomycin - red man syndrome)
--\> induce mast cell degranulation by activation of protein kinase A and PI3 kinase
IgE dependent mast cell degranulation is more due to allergens such as environmental exposures, foods, insect stings, some meds - beta lactam and sulfonamide
--\> cross linking induces teh activation of mast cell degranulation
128
pathogenic diverticula could be due to traction or pulsion...what is the cause of each?
Traction is often due to inflammation that then leads to scarring --\> pulling and outpouching of the layers (usually a true diverticula)
pulsion is often due to increased intraluminal pressure due to straining --\> the mucosa and submucosal (false diverticula) to herniate through areas of muscular weakness
diverticulosis most common at sigmoid colon in pt \>60
129
what nerve is at greatest risk to be injured during a thyroidectomy?
the external branch of the superior laryngeal nerve
innervates the cricothyroid muscle
fxn: tense the vocal cords --\> injury could cause LOW horse voice with limited range of pitch
(vs: recurrent laryngeal --\> innervates
130
melanocytic nevi
benign neoplasm of melanocytes, uniform, mitotically quiescent
mature through different phases:
junctional - at the dermal, epidermal junciton, flat, brown to black, darker in the center
coumpound - exist at base of epidermis and extend into dermis
intradermal - loss of epidermal cells and the dermal cells have lost their tyrosinase activity thus skin to tan color, dome shaped sometimes pedunculated
131
Fibromuscular dysplasia
stenosis and aneurysms of medium sized arteries
renal involvement --\> secondary hypertension
causes an apearance of **beads on a string** appearance
non-inflammatory, non-arterosclerotic
\> in renal and carotid arteries
\> young women
