Chapter 17( Immunohematology and Transfusion Medicine)

A 17-year-old man is admitted with multiple injuries after his motorcycle crashes. The emergency department physician draws a blood sample for a STAT type and crossmatch. The motorcyclist's passenger also has blood drawn for a STAT type and screen. An immediate-spin crossmatch is compatible between the group A patient and group A donor. The unit of blood is issued from the blood bank as an emergency release. After receiving 50 mL of the first unit of RBCs, the man develops shaking chills and becomes hypotensive with a falling blood pressure. The unit of cells is immediately discontinued, and the transfusion service is notified of the situation. A recheck of testing is requested immediately.

Laboratory Testing Clerical check:

No evidence of clerical errors

Hemoglobinemia: Slight hemolysis observed

Direct antiglobulin test

Patient pretransfusion: Negative

Patient posttransfusion: Weakly positive

Recheck of blood grouping

pretransfusion: A positive Patient

posttransfusion: O positive

Donor: A positive

Repeat crossmatches

Patient pretransfusion + Donor red blood cells = Compatible

posttransfusion + Donor red blood cells = Incompatible

Critical Thinking Group Discussion

1. Why did this patient experience shaking chills and other adverse effects after receiving only 50 mL of red blood cells?

2. If the patient's adverse reaction to the blood transfusion had not been noted soon after the beginning of the transfusion, what physiologic changes would have occurred to the patient?

PneumoTech, Inc. is studying the addition of a new valve to its product line. The valve would be used by manufacturers of pneumatic equipment. The company anticipates starting with a relatively low sales volume and then boosting demand over the next several years. A new salesperson must be hired because PneumoTech's current sales force is working at capacity. Two compensation plans are under consideration:

           Plan A:    An annual salary of $33,000 plus a 10% commission based on gross dollar sales.

           Plan B:    An annual salary of $99,000 and no commission.

PneumoTech, Inc. will purchase the valve for $75 and sell it for $120. Anticipated demand during the first year is 6,000 units. (In the following requirements, ignore income taxes.)

Required:

1. Compute PneumoTech's break-even point for Plan A and Plan B.

2. What is meant by the term operating leverage?

3. Analyze the cost structures of both plans at the anticipated demand of 6,000 units. Which of the two plans is more highly leveraged? Why?

4. Assume that a general economic downturn occurred during year 2, with product demand falling from 6,000 to 5,000 units. Determine the percentage decrease in company net income if PneumTech had adopted Plan A.

5. Repeat requirement (4) for Plan B. Compare Plan A and Plan B, and explain a major factor that underlies any resulting differences.

6. Briefly discuss the likely profitability impact of an economic recession for highly automated manufacturers. What can you say about the risk associated with these firms?

This question has its origin to the reference on the Aegis experiment at CERN where they aim to produce super cooled antihydrogen and detect whether its reaction to gravity is negative.

It set me thinking that the beams in the Tevatron circulate for more than a second and everything falls about 4.9 meters in a second, so the bunches must be falling too. This of course will be compensated by the fields that keep the bunches in track among all the other corrections necessary. If though the antiprotons have a different behavior under gravity, this difference would appear in the orbits of protons and antiprotons.

The question has two points: a) since the beams are travelling equal and opposite paths through the magnetic circuit, a negative gravity effect on antiprotons would disperse the antiproton beam up with respect to the path of the proton one. Could one get a limit on the magnitude of the gravitational effect difference between protons and antiprotons from this?

I found one reference where the antiproton beam has a different behavior in chromaticity than the proton one, and it is explained away.

Now I am completely vague about beam dynamics which I have filed under "art" rather than "physics" but b) am wondering whether this observed difference could be interpreted as a gravitational field difference in a dedicated experiment.

Maybe there are beam engineers reading this list. My feeling is that if antiparticles had negative gravity interactions , beam engineers would have detected it since the first e+e- machine, but feelings can be wrong.

If a nation’s economy is sliding into recession, and you are an economist, would you recommend that the government cut taxes and then make up for the drop in taxes collected by the government by cutting government spending? If not, what would you recommend? Explain your answer.

Permanent Income Hypothesis holds true (by friedman) then government stabilization policies would be ineffective. However, empirically, the data shows that for example, tax cuts/credits can encourage more consumer spending. How do you explain this?

What societal changes have affected the cost of health care? How has the government responded to contain and reduce health care spending? What role should government play in controlling the cost of care and ensuring health coverage?

Assume that an effective government-imposed price on a particular good. The price is set below equilibrium. Now, the imposed price is removed.

True, False, or Uncertain: Consumer spending on the good will increase only if demand is inelastic. Explain your answer.

1. Explain, using Keynes’s concept of the marginal efficiency of capital, how it is possible foe investment spending to decline, even though the market rate of interest remains unchanged.

2. As the classical school is to Isaac Newton, the Institutionalist school is to whom? Explain.

Assume: a = 150, b = .75, I = 200, Yf = 1600

The equilibrium level of output and income is?

The value of consumption at the equilibrium level of output and income is?

Aggregate spending at full employment is?

The value of savings at full employment is?

The recessionary gap is?