The Little Plates

Today, WLBOTT proudly celebrates Elder JimZim‘s platelet donations.

Gentle People – in an attempt to ignore unpleasant 4th of July topics, I decided to waste a little time on the internet and my calculator. Over the past year, I have donated platlets 24 times. At each donation, they harvest 6.4E+11 platlets. Thus, the yearly harvest is 15E+12 (15 trillion) Platelets. To put it in perspective, 15 trillion is:

• 10 times the number of Platelets circulating in the average healthy human
• 7 times the number of galaxies in the universe
• 15 times Musk’s net worth
• 3 times the number of miles in light year
• 5 times the number of trees on earth
• 1/2 the number of lies told by the GOP in one day
• Number of seconds that have elapsed since 475,000 BC (475000 BC was in the Stone Age)
• Number of calories consumed by the world’s population in 1 year
• 15 trillion times greater than the number of people that find this interesting

Elder JimZim

We are proud of Elder JimZim‘s generous spirit, and the sacrifices he has made over the past year.

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There have been challenges. Although not technically disqualifying, the pre-screening process revealed a record-high blood methane count.

And because of his unique diet, the team had to put in a custom filtration system for Elder JimZim‘s apheresis:

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Platelets – The Nuts and Bolts

Platelets are a type of blood cell whose job is to plug the leaks.

Platelets or thrombocytes (from Ancient Greek θρόμβος (thrómbos) ‘clot’ and κύτος (kútos) ‘cell’) are a part of blood whose function (along with the coagulation factors) is to react to bleeding from blood vessel injury by clumping to form a blood clot. Platelets have no cell nucleus; they are fragments of cytoplasm from megakaryocytes which reside in bone marrow or lung tissue, and then enter the circulation. Platelets are found only in mammals, whereas in other vertebrates (e.g. birds, amphibians), thrombocytes circulate as intact mononuclear cells.

In addition to facilitating the clotting process, platelets contain cytokines and growth factors which can promote wound healing and regeneration of damaged tissues.

Wikipedia

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And Where Do the Little Plates Come From?

A megakaryocyte (from mega- ‘large’, karyo- ‘cell nucleus’ and -cyte ‘cell’) is a large bone marrow cell with a lobated nucleus that produces blood platelets (thrombocytes), which are necessary for normal clotting. In humans, megakaryocytes usually account for 1 out of 10,000 bone marrow cells.

In general, megakaryocytes are 10 to 15 times larger than a typical red blood cell, averaging 50–100 μm in diameter. During its maturation, the megakaryocyte grows in size and replicates its DNA without cytokinesis in a process called endomitosis. As a result, the nucleus of the megakaryocyte becomes very large and lobulated (8 in number), which, under a light microscope, can give the false impression that there are several nuclei. In some cases, the nucleus may contain up to 64N DNA, or 32 copies of the normal complement of DNA in a human cell.

These functional subpopulations include:
Thrombopoietic megakaryocytes: The classic platelet-producing cells with high expression of genes involved in platelet formation and release.

Platelet release
Once the cell has completed differentiation and become a mature megakaryocyte, it begins the process of producing platelets. The maturation process occurs via endomitotic synchronous replication whereby the cytoplasmic volume enlarges as the number of chromosomes multiplies without cellular division. The cell ceases its growth at 4N, 8N or 16N, becomes granular, and begins to produce platelets.

Wikipedia

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What Activates the Platelets?

Normally, platelets are little globes, but when they sense danger, they transform into octopus-like warriors. The University of Oklahoma has a good introduction to platelets.

Platelets are the smallest of the three major types of blood cells.

Platelets are only about 20% of the diameter of red blood cells. The normal platelet count is 150,000-350,000 per microliter of blood, but since platelets are so small, they make up just a tiny fraction of the blood volume. The principal function of platelets is to prevent bleeding.

Platelet Function
In addition to being the smallest blood cell, platelets are also the lightest. Therefore they are pushed out from the center of flowing blood to the wall of the blood vessel. There they roll along the surface of the vessel wall, which is lined by cells called endothelium. The endothelium is a very special surface, like Teflon, that prevents anything from sticking to it. However when there is an injury or cut, and the endothelial layer is broken, the tough fibers that surround a blood vessel are exposed to the liquid flowing blood. It is the platelets that react first to injury. The tough fibers surrounding the vessel wall, like an envelop, attract platelets like a magnet, stimulate the shape change that is shown in the pictures above, and platelets then clump onto these fibers, providing the initial seal to prevent bleeding, the leak of red blood cells and plasma through the vessel injury.

University of Oklahoma

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Platelets were discovered by Giulio Bizzozero^[1], an Italian doctor and medical researcher.

^[1] Bizzozero: This is the coolest surname we’ve come across in a while.

In 1881 he described platelets as a third element in blood after the erythrocytes and leucocytes. Platelets had been described by Max Schultze in 1865 but Bizzozero identified their function. He called them piastrine (Italian), plaquettes (French) and Blutplattchenin (German).

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The Wheat and the Chaff

So how do the folks at the blood bank extract the platelets? What’s the experience look like to Elder JimZim?

Elder JimZim arrives at the blood bank and is greeted by the friendly MD Anderson staff.

They’ve got a sweet ride.

At the front desk, Elder JimZim checks in and inquires about the bloodmobile. How many donations are needed to drive the bus? The staff politely (but firmly) asks him to sit down and wait for his name to be called.

There is a brief pre-screening procedure, where that draw a small amount of blood. They want to check his platelet count, blood type, and red cell percentage (hematocrit^[1]). They also check your blood pressure, temperature, and make sure you are over 110 pounds. Elder JimZim also confirms that he is not currently pregnant. There are also some screening questions: Are you feeling healthy? What medications are you taking? Travel history? For WLBOTT Elders Only: Have you eaten at the Ladle & Lube in the past 72 hours?

^[1] HCT (hematocrit) is a blood test measuring the percentage of your blood made up of red blood cells. Typical normal ranges are 41% to 50% for adult males and 36% to 48% for adult females. – Gemini

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In a few minutes they call Elder JimZim’s name. He’s led to a brightly lit apheresis room, with comfortable couches and apheresis machines. There are several other donors in the room, in different phases of the donation process. Elder JimZim gets comfortable – he’s going to be strapped in for about an hour and a half.

This center uses a modern apheresis machine – the one-arm. The machine draws Elder JimZim‘s blood, does it’s magic, extracts the platelets, and returns the remaining blood back to him. This cycle repeats until the machine has collected enough platelets. Older machines used both arms – one arm to draw the blood, the other arm for the return. The one-arm machine leave Elder JimZim with the flexibility to practice his sock puppet ventriloquist routine with his other arm, to the delight of both staff and other donors.

The plastic kits that are used for apheresis collection cost about $150+, and the machines run between $30K and $100K. The process takes one to two hours.

The blood center has gone out of their way to provide a comfortable and safe experience for the donors. But the expense of the equipment, staff, and building are all dwarfed by the cookie budget. Elder JimZim is rewarded for his donation by a buffet of biscuits and sweets.

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How Does It Work?

The blood stays completely within the closed system of the apheresis kit.

(From Elder G and other on-line resources)

The centrifuge is part of the disposable kit

Inside the kit is a specially designed centrifuge bowl (or, on some systems, a separation chamber). The bowl is made of clear medical-grade plastic and is discarded after the donation.

The machine has a spindle or rotor that grabs onto this disposable bowl and spins it at high speed, typically several thousand RPM.

Think of it like this:

• The plastic bowl belongs to the kit.
• The motor belongs to the machine.

Blood enters the spinning bowl

As whole blood is drawn from the donor, it flows through sterile tubing into the spinning bowl.

Because of centrifugal force, the blood components separate according to density:

1. Red blood cells move toward the outside.
2. White blood cells form a thin “buffy coat.”
3. Platelets collect in a layer just inside the buffy coat.
4. Plasma remains closest to the center.

The machine continuously monitors where these layers are.

How does it know where the platelets are?

This is another elegant bit of engineering.

Many machines shine light through the transparent spinning bowl. Optical sensors detect the interfaces between the different layers because each layer scatters light differently.

The software adjusts the flow rates so that only the platelet-rich layer is siphoned off while the red cells stay where they belong.

It’s almost like an automatic transmission that’s constantly adjusting itself, except instead of gears it’s tracking microscopic layers of blood components.

The apheresis machine is almost like a computer with no “data” stored inside it. The disposable kit is analogous to removable media:

• Machine: motors, sensors, pumps, software, user interface.
• Disposable kit: tubing, centrifuge bowl, valves, collection bags, and the sterile fluid path.

The machine provides all the “intelligence” and mechanical energy, while the disposable kit provides the sterile environment.

Wikipedia documents two notable corporate screw-up:

Kit problems
Two apheresis kit recalls were:

• Baxter Healthcare Corporation (2005), in which “pinhole leaks were observed at the two-omega end of the umbilicus (multilumen tubing), causing a blood leak.”[13]
• Fenwal Incorporated (2007), in which there were “two instances where the anticoagulant citrate dextrose (ACD) and saline lines were reversed in the assembly process. The reversed line connections may not be visually apparent in the monitor box, and could result in excessive ACD infusion and severe injury, including death, to the donor.”[

Wikipedia

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Single-use WLBOTT Southern Cuisine Apheresis Kit™

Many come to the Ladle & Lube for the fine dining experience.

Our more health-conscious diners are focused on the nutrition and select ingredients. For them, we’ve installed the WLBOTT Southern Cuisine Apheresis Kit™.

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Honoring Our Hero

We had both a private ceremony, hosted by the WLBOTT Ministry of Virtue and Vice….

… and a public dedication of the Elder JimZim Recovery Throne.