Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Chemistry > Exam 10 (Tumor markers, NPNs, Calcium and Bone homeostasis) > Flashcards

Exam 10 (Tumor markers, NPNs, Calcium and Bone homeostasis) Flashcards

1
Q

Which non protein nitrogen is found in greatest concentration in plasma?

A

Urea nitrogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Urea is excreted by all of the following, except:
A. GI tract
B. kidneys
C. skin
D. breath

A

D

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How can urea nitrogen be converted to urea concentration?

A

Multiply by 2.14

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Analytical methods for Urea

A

Urease (most common)
GLDH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Azotemia

A

Elevated urea in blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Uremia

A

Elevated urea in blood WITH renal failure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Causes of prerenal azotemia

A

CHF, Shock, dehydration (circulation-related)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Causes of renal azotemia

A

Renal failure, glomerulonephritis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Cause of post-renal azotemia

A

Obstruction such as tumor or kidney stone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

T/F: creatinine remains stable daily

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What NPN is associated with muscle mass?

A

Creatinine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is inversely proportional to GFR?

A

Creatinine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the analytical methods for creatinine?

A

IDMS
Jaffe reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the GFR?

A

Volume of plasma filtered by the glomerulus per unit of time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the formula for GFR?

A

(urine creatinine)(urine volume)/plasma creatinine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Renal clearance substance measurement characteristics

A
  1. stable concentration in plasma
  2. physiologically inert
  3. freely filtered at the glomerulus
  4. do not want kidney to secrete/reabsorb/metabolize it
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Formula for creatinine clearance

A

U x V 1.73
______ x _______
P SA patient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What four variables are in the CKD-EPI/MDRD measurement for eGFR?

A

Serum/plasma creatinine
patient age
patient gender
patient ethnicity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Equations to measure eGFR

A

Schwartz
MDRD
CKD-EPI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

eGFR <15 = ?

A

Kidney failure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the normal BUN/creatinine ratio?

A

10:1 or 20:1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Clinical applications of uric acid measurement

A

Detect and monitor kidney disfunction
Detect kidney stone formation
Monitor conditions with increased nucleic acid catabolism (leukemia, lymphoma)
Toxemia of pregnancy (Preeclampsia)
Gout

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Analytical methods for uric acid measurement

A

Uricase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the #1 application of ammonia measurement?

A

Hepatic failure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Why would ammonia levels be measured?
Hepatic failure Reye's syndrome
26
What are the special considerations when handling ammonia samples?
Tube should be full and put on ice immediately after collection since ammonia is very unstable Should be refrigerator-centrifuged Hemolysis heavily affects ammonia levels
27
Benign vs malignant
Benign = non cancerous, stays at primary site Malignant = cancerous, has potential to spread to other sites
28
Metastasis
Spread of cancer to other parts of the body
29
Apoptosis
Programmed cell death (natural part of normal cell)
30
Angiogenesis
Creation of blood vessels
31
Oncogene vs tumor suppressor genes
Oncogene = bad, encodes for uncontrolled cell growth TSG = good, encode for proteins that suppress tumor cells
32
Stage I to Stage IV of cancer
stage 1 = localized primary tumor stage 2 = invasion of primary tumor through epithelium and into blood vessels stage 3 = migration of tumor into lymph nodes stage 4 = metastasis and invasion of tumor into distant tissues
33
Characteristics of an ideal tumor marker
1. easy to measure, inexpensive, and easily obtained from body fluids 2. be specific to a tumor 3. have a correlation between measured level and tumor size 4. have an abnormal level at early stage 5. have stability (do not fluctuate) 6. if present in benign conditions, is at much lower level than malignant conditions
34
What will a low cutoff value affect for tumor markers?
High sensitivity Low specificity False positives
35
What will a high cutoff value affect for tumor markers?
Low sensitivity High specificity False negatives
36
Sensitivity
Ability of assay to detect disease
37
Specificity
Ability of assay to classify individuals who do not have the disease
38
PPV
Probability of having the disease if test is positive
39
NPV
probability of having the disease if test is negative
40
Prevalence
frequency of disease in a given population
41
What is the Hook Affect?
When there is so much tumor marker present that the response is not accurate; resolve by diluting specimen
42
ACTH
elevated levels found in pituitary adenomas and ectopic ACTH-producing tumors
43
Estrogen and progesterone receptors
Associated with some types of breast cancer
44
Calcitonin
Associated with medullary thyroid cancer
45
hCG
Can be produced in trophoblastic tumors, choriocarcinoma, and germ cell tumors of the ovary and testis (preferable to use beta-hCG)
46
AFP
Oncofetal antigen ADP normally elevated in newborns If elevated in adults = liver cancers, teste cancers, ovarian cancers, hepatitis, cirrhosis
47
CEA
Elevated in colorectal, GI, lung, and breast cancer Can be elevated in smokers
48
CA 15-3 and CA-27.29
Associated with breast cancer Elevated levels seen in 70-80% of metastatic breast cancers Useful for monitoring, not screening
49
CA 125
Detects ovarian cancer
50
What can be run in parallel with CA 125 to improve sensitivity?
Transferrin, B2 microglobulin, apolipoprotein, lipase
51
CA 19-9
Non-specific, but can be suggestive of pancreatic cancer, lung cancer, colorectal cancer, and hepatobiliary cancer **Related to Lewis blood group antigen If Lea and Leb negative, cannot produce CA 19-9
52
Thyroglobulin
Elevated levels associated with thyroid cancer
53
Chromogranin A
Released from adrenal medulla Elevated in patients with neuroendocrine tumors
54
PSA
Only tumor marker currently FDA approved for screening for disease Can also be elevated in benign prostatic hyperplasia and prostatitis (NOT specific to only prostate cancer)
55
PSA levels and their associations with prostate cancer/benign prostatic hyperplasia
PSA <4 is normal PSA 4-10 could be BPH PSA >10 associated with prostate cancer 67% of the time PSA >50 associated with prostate cancer 99% of the time
56
Osteoblasts vs osteoclasts
Osteoblasts = build bone Osteoclasts = break bone down
57
If blood calcium levels are decreased, what will PTH do?
Increase
58
If blood calcium levels are increased, what will PTH do?
Decrease
59
How do PTH affect calcium
Inc PTH = Inc calcium
60
What is the most important test in differential diagnosis of hypercalcemia?
PTH
61
2 causes of hypercalcemia related to PTH
1. Primary hyperparathyroidism 2. hypercalcemia-associated malignancy
62
What is the most common cause of hypocalcemia?
Chronic renal failure
63
Pseudohypoparathyroidism
Increased PTH
64
Active metabolite of Vitamin D
1,25 (OH)2 AKA calcitriol - made in kidneys only
65
What is the form of vitamin D that is measured in the lab?
25(OH)
66
Increased PTH with decreased phosphate = ? vitamin D
Increased
67
Decreased calcium and Increased PTH = ? vitamin D
Increased
68
How much calcium is ionized? aka free
50%
69
How much calcium is bound to proteins?
40%
70
How much calcium is complexed with small anions?
10%
71
Causes of hypocalcemia
Hypoparathyroidism Vitamin D deficiency Hypomagnesemia Chronic renal failure Hypoalbuminemia
72
S&S of hypercalcemia
Lethargy Decreased alertness Depression
73
S&S of hypocalcemia
tetany numbness tingling
74
Most common cause of hypercalcemia in outpatients?
Primary hyperparathyroidism
75
Most common cause of hypercalcemia in inpatients?
Malignancy
76
What medications can cause hypercalcemia?
Lithium Thiazide diuretics High doses of vitamin A high doses of vitamin D Milk-alkali syndrome
77
What can be measured with hepatitis C antibody to help tell us how long the patient has been infected?
HCV RNA and ALT
78
What does Hep C antibody tell us?
Tells us patient has been infected before, but not specific for acute/chronic or if they are currently infected or not
79
What substances can be used to measure renal clearance?
Inulin, Cystatin C, Creatinine
80
Pros/cons of Inulin as a measurement of renal clearance
Pros: exogenous (not normally found in body) Cons: IV injection to administer, do not have widely available measurement techniques in the lab
81
Pros/cons of cystatin C as a measurement of renal clearance
Pros: LMW protein, easy to use, levels unaffected by gender/diet/muscle mass Cons: Concentrations can be affected by thyroid disease, most labs do not have methods
82
Pros/cons of Creatinine as a measurement of renal clearance
Pros: automated methods available, can use serum, plasma, or urine
83
What is the most common method used to measure renal clearance? Is it the best method?
Creatinine. It is not the best method, but the most common one that is available.

Chemistry (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions