Path: Nutritional Pathology

Question 1

What is the difference b/w primary and secondary malnutrtion?

Answer 1

primary - intake is not sufficient

secondary - intake is sufficient, but improper use or storage, increased loss or need, malabsorption

Question 2

When is a child considered to be malnourished?

Answer 2

body weight below 80% ideal

Question 3

What are the two types of primary protein-energy malnutrition?

Answer 3

marasmus = calorie deficiency affects somatic protein compartment (skeletal muscle)
kwashiorkor = protein deficiency affects visceral protein compartment (liver, etc)

Question 4

What are the features of marasmus?

Answer 4

loss of SC fat and muscle
maintained serum albumin
emaciated w weight loss (less than 60% ideal BW)
immune deficiencies

Question 5

What are the features of kwashiorkor?

Answer 5

sparing of SC fat and muscle
low serum albumin and other proteins
protuberant abdomen, edema due to hypoalbuminemia (60-80% ideal BW)
skin lesions = flaky paint sign
immunodeficiencies

Question 6

What can cause secondary protein-energy malnutrition?

Answer 6

cachexia (cancer, AIDS)

chronic GI dz, elderly, severe trauma, sepsis, burns

Question 7

What is the pathophysiologic basis for obesity?

Answer 7

disorder of energy balance, central sensor = hypothalamus
stomach releases ghrelin when food intake needed
fat cells release leptin when food intake not needed

Question 8

What kinds of mutations can cause obesity?

Answer 8

mutations in genes encoding leptin, its receptor and components of anorexigenic pathway
MC4R mutations (target of anorexigenic neurons)

Question 9

What are the sources of vitamin A?

Answer 9

liver, dairy, dark yellow/orange fruits, green leafy vegetables, derived from retinoic acid
humans have a 6 month store in Ito cells

Question 10

What are features of vitamin A def?

Answer 10

night blindness - earliest manifestation
xerophthalmia
squamous metaplasia of respiratory and urothelial mucosa
follicular dermatosis
immune deficiency
keratomalacia = softening and destruction of cornea
Bitot spots = opaque spots on eye from keratin debris

Question 11

What are the features of vitamin A toxicity?

Answer 11

acute: headache, irritability, vomiting, stupor, papilledema
chronic: N/V, weight loss, lip dryness, skin peeling, hyperostosis w bone pain, osteoporosis, hepatomegaly w hepatic fibrosis

Question 12

What are the teratogenic effects vitamin A toxicity?

Answer 12

cleft palate, CV, renal, limb defects, thymic agenesis, embryonic lethality

Question 13

What are sources of vitamin D?

Answer 13

sunlight, fortified foods (milks, grains), fatty fish and fish oil, plants and grains

Question 14

What are the features of vitamin D def?

Answer 14

rickets in children - overgrowth of cartilage at epiphyseal plates
osteomalacia in adults: deranged bone remodeling –> gross or micro fractures, wide unmineralized osteoid

Question 15

What is the normal fxn of vitamin D?

Answer 15

absorption of calcium and phosphorous, mobilizes Ca from bone w PTH

Question 16

What are the features of rickets?

Answer 16

frontal bossing, Harrison’s groove, delayed closure of cranial sutures, rachitic rosary, pigeon breast deformity, kyphoscoliosis and lumbar lordosis, genu valgus/varus, widened wrists and ankles, greenstick fractures, familial rickets

Question 17

What are the features of vitamin D toxicity?

Answer 17

anorexia, N/V
polyuria, polydipsia
weakness, nervousness
pruritus
impaired renal fxn --> proteinuria, casts, azotemia
metastatic calcifications

Question 18

What are sources of vitamin E?

Answer 18

vegetables, grains, nuts and their oils, milk products, fish, meat, fortified breakfast cereals, supplements

Question 19

What are the features of vitamin E deficiency?

Answer 19

rare, neuropathy, posterior column and spinocerebellar degeneration, hemolytic anemia, familial def from mutations in gene encoding TTPA

Question 20

What are the features of vitamin E toxicity?

Answer 20

rare, muscle weakness, fatigue
nausea, diarrhea
antagonizes vit K action and enhances action of oral coumarin anticoagulants

Question 21

What are the sources of vitamin K?

Answer 21

intestinal flora, diet, efficiently recycled

Question 22

What are the features of vit K def?

Answer 22

bleeding diathesis, hemorrhagic dz of newborn

Question 23

What are the features of vit K toxicity?

Answer 23

phylloquinone (vit K1) not toxic at 500x daily amount
menaquinone (vit K2 precursors) toxic –> anemia, hyperbilirubinemia, kernicterus in infants
vit K3 toxic - banned from supplements

Question 24

What can cause vit K def?

Answer 24

coumarin anticoagulants create def
familial combined def of vit-k-dependent clotting factors due to mutation in gamma glutamyl carboxylase or vit K epoxide reductase
destruction of endogenous vit K synthesizing flora by antibiotics
neonatal period susceptible - bacteria not dev, liver small, breast milk levels low

Question 25

What are the features of vitamin C def?

Answer 25

scurvy: hemorrhages (purpura and ecchymoses on the skin and mucosa, subperiosteal hemorrhages, neuro hemorrhages), skeletal changes (poor formation of matrix, bowing of legs, sternal depression, widening of epiphyses), papular rash ringed by hemorrhages, impaired wound healing

Question 26

What syndromes can be caused by a vitamin B1 def?

Answer 26

dry beriberi (polyneuropathy)
wet beriberi (CV syndrome)
wernicke encephalopathy
korsakoff psychosis
subclinical def (think chronic alcoholics) - can convert to overt by extended IV glucose therapy (give thiamine with it!) or refeeding of malnourished
thiamine responsive megaloblastic anemia, DM, sensorineural deafness

Question 27

What are the features of dry beriberi?

Answer 27

symmetric peripheral neuropathy
mixed motor and sensory symptoms
toe, foot, and wrist drop

Question 28

What are the features of wet beriberi?

Answer 28

heart failure w peripheral edema
peripheral vasodilation –> high output cardiac failure
DCM
heart enlarged and globular, 4 chamber dilation, thin walls

Question 29

What are the features of Wernicke encephalopathy?

Answer 29

reversible
ophthalmoplegia, nystagmus
ataxia
global confusion, apathy, disorientation
hemorrhage and necrosis in mamillary bodies, periventricular regions of thalamus, floor of 4th ventricle, ant cerebellum

Question 30

What are the features of Korsakoff psychosis?

Answer 30

irreversible
memory disturbances: retrograde amnesia w confabulation, anterograde amnesia (can’t acquire new info), due to lesions in medial dorsal nucleus of thalamus

Question 31

What are the features of vitamin B2 (riboflavin) def?

Answer 31

ariboflavinosis:

angular stomatitis or cheilosis, glossitis, interstitial keratitis, dermatitis of cheeks, scrotum and vulva

Question 32

What are the features of vitamin B3 def (niacin)?

Answer 32

pellagra:
diarrhea (atrophy and ulceration of GI mucosa), dermatitis, photosensitivity, glossitis, dementia (degeneration of brain neurons)
necklace = erythema and scales around neck

Question 33

What are the features of vitamin B6 (pyridoxine) def?

Answer 33

dermatitis, cheilosis, glossitis, peripheral neuropathy, convulsions, pyridoxine-dependent epilepsy
can be caused by long-term isoniazid

Question 34

What are the features of vitamin B9 (folic acid) def?

Answer 34

megaloblastic anemia
GI signs and symptoms: sore tongue w taste bud atrophy, small bowel villous and crypt atrophy w megalocytosis, diarrhea and weight loss
fetal neural tube defects

Question 35

What are the features of vitamin B12 (cobalamin) def?

Answer 35

same as vitamin B9 +
subacute combined degeneration of spinal cord - hits dorsal columns and descending corticospinal tracts
treatment w folate improves anemia but not neurological symptoms