Chemistry Week 2 Emma version

Trinder Reaction

Trinder Reaction

Glucose + H20 + 02 --glucose-oxidase--> gluconic acid + H202

H202 + chromagen --peroxidase--> chromagen + 2H20

What is the Trinder reaction used for?

point of care glucose

What causes diabetic ketosis?

Lack of insulin; ketones accumulate in blood

Causes of hypoglycemia

insulin overdose, insuloma, neonate whose mother was given insulin, medications

What is the reagent that's used to detect urinary or serum ketones? What color does it turn?

sodium nitroprusside; purple

What is the coenzyme that's used in the hexokinase method for glucose measurement, and how is it used to quantiate the glucose level?

G6PD

Reference range for serum glucose?

70-100 mg/dL

At what blood glucose level do symptoms of hypoglycemia usually occur?

<55 mg/dL

What is gestational diabetes?

glucose intolerance during pregnancy

Do diabetics remove glucose from the blood faster or slower than a normal person?

slower

Describe Type I diabetes

Insulin deficiency; require insulin; early onset; can progress to ketoacidosis if untreated

Describe Type II diabetes

Insulin resistance; later onset; can be managed by diet and lifestyle changes

At what serum glucose range does glycosuria occur?

160-180 mg/dL

If a diabetic patient has an elevated fasting glucose and an elevated glycosylate hemoglobin, what conclusions can be drawn about his/her glucose control?

uncontrolled

If a diabetic patient has an normal fasting glucose and an elevated glycosylate hemoglobin, what conclusions can be drawn about his/her glucose control?

uncontrolled

If a diabetic patient has an elevated fasting glucose and a normal glycosylate hemoglobin, what conclusions can be drawn about his/her glucose control?

controlled

If a diabetic patient has a normal fasting glucose and a normal glycosylate hemoglobin, what conclusions can be drawn about his/her glucose control?

controlled

A diabetic is considered to be under good control if their glycosylated hemoglobin is what percentage?

<7%

Which glucose methods measure true glucose?

glucose oxidase, hexokinase

What test can be done to distinguish hypoglycemia and hyperglycemia?

blood glucose

What are the conditions that much be met prior and during the OGTI so that the results are reliable?

Fasted beforehand
Given 75 g glucose load

If a diabetic patient has a really elevated glucose level such as 572 mg/dL and has 3+ ketones in his serum, what condition does he have?

Diabetic ketoacidosis

What types of meningitis can cause a reduced CSF glucose level?

bacterial, fungal, tubercular

What causes the electrolyte imbalance that occurs in uncontrolled diabetes?

Polydipsia, polyuria

Glycogenolysis

breakdown of glycogen to glucose

Glycolysis

Breakdown of glucose for energy production

Glycogenesis

Excess glucose is converted and store as glycogen

Gluconeogenesis

Conversion of amino acids into glucose (takes place in liver)

Lipogenesis

Conversion of carbohydrates into fatty acids :(

Is blood glucose increased or decreased in uncontrolled diabetes?

Increased

Is glucagon levels increased or decreased in uncontrolled diabetes?

Increased

Is insulin levels increased or decreased in uncontrolled diabetes?

decreased

Is glycogenolysis increased or decreased in uncontrolled diabetes?

increased

Is gluconeogenesis increased or decreased in uncontrolled diabetes?

Increased

Is lipid metabolism increased or decreased in uncontrolled diabetes?

increased

Is urinary and serum ketones increased or decreased in uncontrolled diabetes?

increased

Name the three ketone bodies

acetone
acetoacetate
B-hydroxybutyrate

List the interferences for the glucose oxidase procedure

ascorbic acid, bilirubin, uric acid

Why is sodium fluoride used in certain situations when collecting samples for glucose analysis?

Inhibits glycolysis

CSF glucose formuka

Lower range: SGV x 0.6
Upper range: SGV x 0.7

If a patient has a serum glucose value of 98, what is their CSF glucose level?

58-68 mg/dL

List the sources of error when performing the glycosylated hemoglobin procedure

hemoglobinopathies

Reference range for CSF glucose

60-70% of plasma glucose

Fructosuria

fructose in urine

galactosemia

increased galactose

Von Gierke's Disease

glycogen cannot be converted back to glucose

Microalbumin screens for

renal failure/damage

Best assay to determine a patient's current glucose concentration in circulation

Serum/plasma glucose level

What is the estimated level of plasma glucose if a capillary puncture results as 77.0 mg/dL

88 mg/dL

Type I diabetes can be associated with the destruction of what cells?

Pancreatic beta cells in the Islets of Langerhan

Monitoring long-term glucose control in patient with adult onset type II diabetes can be best accomplished by testing

Hemoglobin A1C

A patient has a serum glucose of 220 mg./dL. What is the approximate glucose range in the patient's CSF?

132-154 mg/dL

A random plasma glucose level greater than _______ on 2 occasions along with symptoms is diagnostic of DM

200 mg/dL

Which hemoglobin A1c value indicates the diabetic patient is not demonstrating glucose control?

7.0%

Which is the only hormone that decreases blood glucose levels?

insulin

In the hexokinase glucose method what end product is measured?

NADPH @ 340nm

Are ketones typically seen in the urine of type II patients?

no

What are the critical glucose levels?

<40 mg/dL
>400 mg/dL

List the 4 functions of lipids in the human body.

Energy
Structural components of cells
Hormone precursors
Nerve insulators

List the 4 functions of apolipoproteins

Transport lipids through the plasma
Activate and inhibit enzymes that act on lipoproteins
Cofactors for remove of lipoproteins in the plasma
Maintain structure of lipoproteins

An increase in which Apo protein is associated with a decreased risk of CAD?

Apoprotein A1

Which part of the triglyceride molecule is measured to determine the serum triglyceride level?

Glycerol

How long should a patient fast before a specimen is collected for a lipid panel (cardiac risk)?

10-12 hours

How does the Lp(a) level relate to increased risk of CAD?

Increased Lp(a) = Increased risk of CAD
(Increased risk of early atherosclerosis and plaque thrombosis and risk of clotting)

Lp(a) is measured by Immunoassay: Name the Antigen

Lp(a)

Lp(a) is measured by Immunoassay: Name the Antibody

anti-Lp(a)

What is the main component in the LDL fraction of lipoproteins?

Cholesterol

Define: Atherosclerosis

Athero - thick soup
Scleros - hard = hardening of the arteries
Cholesterol deposits and scarred portion of an arterial plaque

Define: Xanthoma

Small, yellow-red papules deposited on the back of forearms, shins and pressure points
Erupt when Triglycerides > 2000 md/dL

Define: Steatorrhea

Excretion of abnormal quantities of fat in feces

Chylomicrons transport _____ from _____ to _____.

Triglycerides
Small intestines
Muscle cells and Adipose tissue

VLDL transports _____ from _____ to _____.

Triglycerides
Liver
Muscle cells and Adipose tissue

LDL transports _____ to _____.

Cholesterol
Liver, tissues, and the endocrine gland

HDL transports _____ from _____ to _____.

Cholesterol
Cells
Liver

Which lipoprotein is cleared from plasma in 6 hours and should be absent from a fasting specimen?

Chylomicrons

What is the appearance of the plasma after 6 hours if Chylomicrons are present?

Creamy white top layer

Name the substance that is produced in the liver from cholesterol, it is stored in the gallbladder and emulsifies fats

Bile

Cholesterol is also used to synthesize what class of hormones?

Steroid

What tests results are included in a Lipid Panel: Indicate which are measured

Total Cholesterol
Triglycerides
HDL

What tests results are included in a Lipid Panel: Indicate which are calculated

VLDL
LDL

State the Friedwald calculation. (Given a set of measured values, be able to calculate the appropriate lipid panel values.)

LDL = CHOL - (HDL + VLDL)

VLDL = Triglycerides/5

State the Optimal and Very High Risk ranges for: Total Cholesterol

Optimal: <200 mg/dL

Very High Risk: > or equal to 240 mg/dL

State the Optimal and Very High Risk ranges for: HDL

Optimal: > or equal to 60 mg/dL

Very High Risk: Men: <40 mg/dL

Women: <50 mg/dL

State the Optimal and Very High Risk ranges for: LDL

Optimal: <100 mg/dL

Very High Risk: > or equal to 190 mg/dL

State the Optimal and Very High Risk ranges for: Triglycerides

Optimal: <150 mg/dL

Very High Risk: > or equal to 500 mg/dL

Why do pre-menopausal women have a decreased risk of atherosclerosis and CAD vs. men of the same age?

Estrogen provides a protective effect against atheroma formation

List 12 other risk factors that increase the risk of cardiovascular disease

Older age
Male
Genetics
Family history
Stress
Hypertension
High homocysteine levels (MTHFR)
Diabetes
Smoking
Inflammation (increased hs-CRP)
Inactivity
Increased Lp(a)

Why do premenopausal women have a decreased risk of atherosclerosis and CAD vs men of the same age?

estrogen

Describe how atherosclerosis happens (or how atheroma's form)

Begins with endothelial damage, lipids and inflammatory cells deposit in the area, the inflammatory cells stimulate collagen production, build up becomes fibrous creating a soft atheroma, repeated cycles of this process causes scarring, chronic inflammation, and calcium to be deposited, producing a hard, calcified atheroma

Describe how atherosclerosis leads to a heart attack

Atheroma in coronary arteries become large enough to block blood and oxygen flow to the heart muscles. Heart muscle without an appropriate amount of oxygen does not function properly, total lack of blood and oxygen flow causes the heart muscle to die = heart attack (MI)

Name the disease when atherosclerosis occurs and blocks blood flow in the following: Aorta

Bulges in aorta
Aneurysm

Name the disease when atherosclerosis occurs and blocks blood flow in the following: Arms/Legs

PVD (Peripheral Vascular Disease)

Name the disease when atherosclerosis occurs and blocks blood flow in the following: Brain

CVD (Cerebrovascular Disease)
Stroke

Define ischemia.

Decreased blood flow

Lipoprotein Lipase deficiency triglyceride levels

>/= 10,000 mg/dL

Lipoprotein Lipase deficiency chylomicrons

increased

Lipoprotein Lipase deficiency typical age of diagnosis

childhood

Lipoprotein Lipase deficiency unique characteristics

abdominal pain

Type V Hyperlipidemia triglyceride levels

increased

Type V hyperlipidemia chylomicrons

increased