Block 28

Question 1

Non modifiable Risk factors for osteoporotic fractures

Answer 1

• age
• white ethnicity
• female sex
• personal or family history of fracture

Question 2

Stress related mucosal disease

Answer 2

-charactrized by acute gastric mucosal defect that develops in response to sever physiologic stress (eg, shock,extensive burns, sepsis and severe trauma). Pts often have multiple, small , circular lesion in the stomach, ranging from superficial erosion to full thickness ulcers.
Ulcers may perforate or bleed as in this patient.
-the pathogenesis of these ulcers often due to local ischemia caused by hypotention or splanchinc vasoconstriction.

Question 3

Curling vs cushing ulcers

Answer 3

• ulcers arising in the proximal duodenum in association with severe trauma/ burns are called curlings ulcers.
• ulcers arising in esophagus, stomach or duodenum in patients with intracranial injury are particularly prone to perforation and are called cushing ulcers. (They are the consequence of vagus stimulation -> Ach release and hypersecretion of gastric acid)

Question 4

Neural tube defect inheritance is

Answer 4

Multifactorial (genetic and envirnomental factors interact to determine phenotypic expression).
Other examples of multifactorial disease inheritance include cleft lip palate, diabetes mellitus, coronary heart disease and hypertension.

Question 5

Chediak higashi syndrome

Answer 5

• autosomal recessive consist of :
  1. Immunodeficiency
  2. Albinism
  3. Neurologic defect (nystagmus)
  4. Peripheral and cranial neuropathies
  5. Failure of phagolysosome fusion

Question 6

DNA polymerase type III function

Answer 6

5’ to 3’ DNA synthesis and 3’ to 5’ exonuclease activity (proofreading (repair ))

Question 7

Gardeners mydriasis

Answer 7

Due to jimson weed poisining, it produces belladona toxin that have high anticholenergic proporties. (Similar to atropine poisining)
Signs include tachycardia, mydriasis , skin flushing, delayed gastric emptying, decreased intestinal motility and secretion, bronchodilation, dry secretion , hallucination and delerium.
Treatment : physostygmine

Question 8

Diabetes ketoacidosis changes in ph,hco3 and buffers in “urine”

Answer 8

1. Increases HCO3 reabsorption
2. Increased H+ secretion(Na/H antiporter in proximal nephron and H atpase and H/K ATPase in a intercalated cells
3. Increased acid buffer excretion (HPO4,NH3 —> NH4…)

Question 9

Gallstone ileus

Answer 9

Uncommon complication of longstanding cholelithiasis that usually occurs in elder women.
- large >2.5 CM gallstone causes formation of cholecystoenteric fistula between gallbladder and adjoining gut due to pressure necorsis and erosion of these tissues.
-stone travels easily until it becomes trapped in the illeum (narrowest portion of intestine)
- patients develops signs of small bowel obstruction, including abdominal pain/ distention, nausea/vomiting, high pitched bowel sounds and tendrness to palpation.
-mmunication may also allow gas to enter the billiary tree ( pneumobilia )
(Not seen in common bile duct occlusion)

Question 10

Persistence of allantois remnant

Answer 10

Around 3 weeks of gestation the yolk sac forms a protrusion that extends into the urogenital sinus. The upper part of the urogenital sinus gives rise to the bladder. The allantois which originally connected to the urogenital sinus with the yolk sac, becomes the urachus, a duct between bladder and the yolk sac. Failure to obliterate before birth :

1. Patent urachus (complete failure of obliteration) , patients presents with straw colored urine discharge from umbilicus, and erythema present.
2. Urachal sinus (failure to close the distal part of urachus) present as periumbilical discharge due to persistent and recurrent infection.
3. Urachal cyst

Question 11

Lateral pontine syndrome

Answer 11

Lesion in AICA
Symptoms include.
1. Lateral spinothalmic tract (controlateral loss of pain and temp )
2. Facial nucleus and nerve.-> ipsilateral paralysis, loss of lacrimation and reduced salivation , taste from 2/3 and corneal reflex
3. Spinal trigiminal nerve (ipsilateral loss of pain and temperature sensation from the face)
4. Vesticular nuclei (nystagmus, nausea, vomiting and vertigo
5. Cochlear nuclei (hearing loss- ipsilateral central deafness
6. Middle cerebellar pudencle ( gait ataxia , dysmetria …)
7. Horner syndrome.

Question 12

Increased blood ammonia levels and orotic acid is seen in

Answer 12

Ornithine transcarbamylase deficiency

Question 13

Ornithine transcarbamylase deficiency

Answer 13

• MCC urea cycle disorder
• results in excess carbomyl phosphate —> stimulate pyrimidine synthesis —> orotic acid accumulates and result in increased urinary orotic acid.
• hyperammonemia due to imapired ammonia excertion, which is a metabolic emergency.
• Tx :protein restriction, sodium benzoate (scavenger for nitrogen), arginine supplementation

Question 14

Metabolic acidosis compensation after 12 hours

Answer 14

After 12 hours of metabolic acidosis, the primary respiratory alkalosis will most likely progress to mixed respiratory alkalosis/metabolic acidosis.
- the PH will most likely become normal if compensetory mechanism is working well (no respiratory failure) however the repiratory alkalosis will be lower than predicted due to concurrent primary respiratory alkalosis.

Question 15

Intususception in young children

Answer 15

Invagination of a portion of intestine into the lumen of the adjacent intestinal segment.
-most typical site is at ileocolic junction. The size differences in the adjacent segments of the intestine allow the small bowel to invaginate into the cecum. Its most common in children younger than 2 years old.

Question 16

13 c labeled urea is used to diagnose ?

Answer 16

The presence of H.pylori

Question 17

S.pneumoniae virulent factor

Answer 17

Polysaccharide capsule.
(Prevents phagocytosis)
(There are >90 different capsule types due to polysaccharide variation)

Question 18

Virulent factor for streptococci

Answer 18

M protein is present in cell wall and has antiphagocytic effects, it also binds to fibrinogen resulting in inflammatory mediator release and vascular leakage.

Question 19

Neonatal abstinence syndrome

Answer 19

-present due to withdrawl from opiates( which the mother was taking)
- NAS can result from illicit maternal drug user or prescribed opiate use
- at risk newborns include those born to mothers with poor mental health, no prenatal care and HEP C infection.
-pathophysiology: withdrawl from transplacental opiates due to maternal drug use
Clinical: neurologic : irritability, hypertonia, jittery movements seizures, GI diarrhea, vomiting, feeding intolerance. Autonomic : sweating, sneezing and pupillary dilation
Treatment : opoid therapy (methadone , morphineO)

Question 20

Prostate cancer spread

Answer 20

• after regional lymph nodes, liver and lung, the skeletal muscle is the fourth system to be involved in the metastasis, which usually disseminate hematogenously.
• cancer of the pelvis, including the prostate spread to the lumbosacral spine via the vertebral venous plexus(VVP).
• VVP communicates with number of venous networks including the prostatic venous plexus, which receives the venous supply from the prostate, penis and bladder.

Question 21

Jugular vein tracing

Answer 21

A=right atrial contraction
C= bulging of tricuspid valve during right ventricular contraction
X= right atrial relaxation
V= continued inflow of venous blood
Y= passive emptying of right atrium after tricuspid valve opening.

Question 22

Constrictive pericarditis on CT

Answer 22

• calcification around the heart is seen in CT
• patients usually have progressive dyspnea, chronic edema, and ascities.
• rapid Y descent .

Question 23

Fabry disease

Answer 23

X-linked recessive, a galactosidase A deficiency results in accumulation of a globotriaosylceramide .(ceramide trihexoside)

• clinically :
  1. Neuropathic pain
  2. Angiokeratomas
  3. Telengectasia
  4. Glomelular disease (CKD)
  5. Cerebervascular diseases(stroke … )
  6. Cardiac disease (LVH)

Question 24

Phenoxybenzamine

Answer 24

Irreversible å1 and å2 blocker.
- its primarily used in treatment of pheochromocytoma in which a tumor of the adrenal medulla overproduces NE, causing systemic arterial vasoconstriction

Question 25

Catalase positive organisms

Answer 25

Most common organism are S.aureus, burkholderia capacia, seetia marescens, nocardia and aspergillus, pseudomonas, E.coli, listeria ,candida, Streptoccus pneumonia/pyogenes are catalase negative.

Question 26

Lopinavir (side effects)

Answer 26

-protease inhibitor used in HIV, these drugs reversibly inhibit viral protease , an enzyme responsible for HIV polyprotein cleavage to form mature viral proteins. PI are never used as monotherapy. Side effects include: 1. Lipodystophy (from face to the back and abdomen) 2. Hyperglycemia (insulin resistance) 3. Inhibit cP450

Question 27

Transpeptidase

Answer 27

- penicillin and cephalosporins function by irreversibly binding to pencillin binding proteins.(PBP) - transpeptidase are one form of PBP that function to cross link with peptidoglycans in bacterial cell wall. - inhibition of transpeptidase leads to cell wall instability and bacteriolysis.

Question 28

Cephalospornins resistance

Answer 28

1. Structual changes in penicillin binding protein that prevent ceftriaxone from binding to bacteria 2. Beta lactamase producing bacteria

Question 29

Transmembrane efflux pumps - antibiotic resistance

Answer 29

This is found in antibiotics that require entery to the cell to function such as tetracyclins and macrolides.

Question 30

If a patient with ulcerative colitis comes to the emergency what is the best initial diagnostic test to be done

Answer 30

- abdominal X ray as it may show colonic dilation with multiple air fluid levels. - free air may also be visualized in the setting of intestinal rupture

Question 31

Jarvell and lange nielsen syndrome

Answer 31

- sinsoneural hearing loss | - congeintal long QT syndrome , with increased risk of sudden cardiac death.

Question 32

Brugada syndrome

Answer 32

Austomal dominant that can be associated with mutation in cardiac sodium of L type calcium channels, leading to ECG changes( pseudo RBBB, ST elevation is V1-V3 and increased risk for ventricular arrythmias and sudden cardiac death.

Question 33

Vitamin E deficiency with CF

Answer 33

- recurrent respiratory infection, diarrhea in a child is highly associated with CF, CF results in fat malabsorption and deficiencies in ADEK vitamins. - VIT E deficiency predispose cell membranes to oxidative injury. This result in hemolytic anemia and neuromuscular disease (ataxia, polyneuropathy .. this is due to susceptibility of neurons with long axon to oxidative injury). - involvement of dorsal common in spinal cord associated with loss of proprioception and vibratory sense.

Question 34

Pernicious anemia

Answer 34

- autoimmune disorder caused by CD4+ cell mediated destruction of parietal cells in the gastric body and fundus. Overtime this results in chronic atrophic gastritis which is characterized histologically as loss of parietal cells with marked lymphocytic plasma cell infiltration. - parietal cells are usually present in the upper glandular layer in the mucosa under epithelial layer

Question 35

Cervical and inguinal lymphadenopathy, headache , sezuires and multiple ring enchancing CNS lesion on MRI , oral thrush . All suggests :?

Answer 35

-HIV patients infected with toxoplasmosis

Question 36

Lambart eaton mesthynic syndrome

Answer 36

- paraneoplastic sequence of small cell lung carcinoma - resent with progressive dizziness, limb and truncal ataxia, dysarthria, and visual disturbances. - paraneoplastic cellebellar degeneration is due to immune response against tumor cells that cross reacts with purkinje neuron antigens, leading to acute onset rapid degeneration of cerebellum. - anti-Yo, anti P/Q, and anti Hu are the most common antibodies present in serum.

Question 37

Acute acalculous cholecystitis

Answer 37

0acute inflammation of gallbladder in the absence of gallstones. - it most commonly occurs in critically ill patients, and is associated with high mortality. The condition is thought to arise secondary to gallbladder stasis and ischemia, which causes inflammation and injury of the gallbladder wall. - clinical manifestation may be subtle especially in those who are sedated or intubated. - fever, RUQ pain, murphy positive, leukocytosis and mild elevation in LFT. - ultrasound shows signs of acute cholecystitis and no gallstones