Carbohydrates Part 2

Question 1

Symptoms unique to adolescent diabetes mellitus

Answer 1

They are the same as adults, but also:

• Blurred vision - frequent infections
• Slow wound healing - Hypertension
• Acanthosis nigricans (skin around neck or armpits appears dark, thick, and velvety)

Question 2

Definition of double diabetes

Answer 2

Child has elements of both Type 1 and type 2 DM

Question 3

How do patients develop double diabetes?

Answer 3

• Type one becomes overweight then becomes insulin resistant
• Type two developed antibodies to beta cells

Question 4

What is the most important factor in the development of adolescent diabetes mellitus?

Answer 4

Important factor is weight gain in diabetic adolescents

Question 5

Typical blood glucose levels and clinical findings in hypoglycemia

Answer 5

Symptoms: weakness, shakiness, sweating, nausea, rapid pulse, lightheadedness, epigastric discomfort

Question 6

Severe Hypoglycemia

• cause
• typical blood glucose concentration

Answer 6

-Severe CNS dysfunction

Question 7

Hypoglycemia in Neonates and Infants

• cause
• typical blood glucose concentration

Answer 7

• due to low glycogen stores at birth

- approximately 35 mg/dL

Question 8

Fasting Hypoglycemia in Adults

• cause
• typical blood glucose concentration

Answer 8

• caused by certain drugs (most common), toxins, advanced liver disease, hormone deficiencies, insulinomas, septicemia, and end-stage renal failure
• < 45 mg/dl

Question 9

Reactive Hypoglycemia

• cause
• typical blood glucose concentration

Answer 9

• Occurs in everyday life after eating

- < 45 - 50 mg/dl

Question 10

Specific enzyme defect in galactosemia

Answer 10

galactase deficiency

Question 11

Clinical symptoms and long-term effects of galactosemia

Answer 11

• infants who fail to thrive on cow’s milk; vomiting and diarrhea
• Later, can cause liver disease, cataracts, and mental retardation

Question 12

Three lab means of galactosemia diagnosis

Answer 12

1. screening urine for reducing substances via Benedict’s Test (Clinitest)
2. ID of the sugar by paper
3. Direct assay of enzyme activity

Question 13

Specific enzyme deficiency of lactose intolerance

Answer 13

lactase deficiency

Question 14

Clinical symptoms of lactose intolerance

Answer 14

1. abdominal pain
2. diarrhea
3. lactose in urine

Question 15

Specific cause of glycogen storage diseases

Answer 15

Caused by deficiencies of a specific enzyme in glycogen metabolism

Question 16

What are the 3 liver forms of glycogen storage diseases?

What are their 4 general clinical biochemical features

Answer 16

Types I, IV, and VI

- are characterized by hepatomegaly,hypoglycemia, decreased insulin, and increased glucagon

Question 17

What are the 4 muscle forms of glycogen storage disease?

What is one general clinical feature of the muscle forms of glycogen storage disease?

Answer 17

Types II, III, V, VII

- appear in young adulthood during strenuous exercise

Question 18

specific enzyme deficiency in von Gierke’s disease

Answer 18

deficiency of glucose-6-phosphatase

Question 19

Is von Gierke’s disease a liver or muscle form of a glycogen storage disease?

Answer 19

Liver form (most common and severe form)

Question 20

Specific enzyme deficiency in Pompe’s disease?

Answer 20

Deficiency of alpha-1,4-glucosidase

Question 21

Is Pompe’s disease a liver or muscle form of a glycogen storage disease?

Answer 21

muscle form

Question 22

Why should separation from the cells or testing must be performed within a half hour of venipuncture in glucose testing?

Answer 22

Glucose decreases up to 7% per hour or more when serum is left in contact with cells

Question 23

Why is oxalate-sodium fluoride the preferred anticoagulant in glucose testing?

Answer 23

(gray top) - it inhibits enolase, a critical enzyme in the glycolytic pathway

Question 24

Whole blood glucose value

Answer 24

60-90 mg/dl

Question 25

Plasma glucose value

Answer 25

70-100 mg/dl

Question 26

Oxygenated, deoxygenated, and capillary blood glucose value

Answer 26

2 to 5 mg/dL higher than deoxygenated samples

Question 27

What is the reason for the prompt analysis of CSF glucose?

Answer 27

due to possible cellular utilization and resultant false picture

Question 28

What is the relationship normally observed between plasma glucose and CSF glucose?

Answer 28

CSF is lower than plasma glucose (60-70%) at the same time

Question 29

Clinical significance for urine glucose

Answer 29

Glucose appears in urine after blood glucose exceededs renal threshold (160-180 mg/dL)

Question 30

specific renal threshold range for urine glucose

Answer 30

160-180 mg/dlL

Question 31

What are the 3 copper reductase methods for glucose?

Answer 31

1. Benedict’s Test (Clinitest)
2. Somogyi-Nelson
3. Neocuproine Copper Reduction

Question 32

Benedict’s copper reduction test (Clinitest)

- principle of measurement

Answer 32

based on the reduction of cupric iron in cupric sulfate. The change in absorbance is measured

Question 33

Benedict’s copper reduction test (Clinitest)

- clinical significance of a positive test

Answer 33

Used as a screen for diseases of inborn errors of carbohydrate metabolism in newborns

Question 34

Benedict’s copper reduction test (Clinitest)

- specific carbohydrates detected

Answer 34

galactose and glucose

Question 35

Benedict’s copper reduction test (Clinitest)

- interferences

Answer 35

include false positives from other sugars, ascorbic acid, salicylates, penicillin, and uric acid