Showing posts with label blood. Show all posts
Showing posts with label blood. Show all posts

22 October 2018

B~L~O~O~D !   part 2

Erythrocyte (red blood cell)
by Leigh Lundin

We return to the spell-binding basics of blood for mystery writers and readers.The previous article carried a simplistic table for matching blood donors:

Simplified Blood Type Transfusions by Phenotype
❤︎ blood r e c i p i e n t
blood type O A B AB
d
o
n
o
r
O
A

B

AB



That’s mostly accurate except the Rhesus factor isn’t taken into consideration. No donor with Rhesus positive blood can donate to an Rh negative recipient. This accounts for the gap in the upper right quadrant of the expanded table below:

Actual Blood Type Transfusions by Rh Factor
❤︎ blood r e c i p i e n t
blood type O+ A+ B+ AB+ O- A- B- AB-
d
o
n
o
r
O+



A+





B+





AB+






O-
A-



B-



AB-






Erythrocyte (red blood cell)
The Story of O

O represents the German ohne, meaning omitted or zero antigens. Some regions and countries code the O as a 0 (zero) or ∅ (null). Students familiar with binary recognize this as a 2-bit situation with four values. Russia and a few other countries label O, A, B, AB blood types as I, II, III, IIII.

Type O negative has been called the universal donor, although the reality is a bit more intricate. Type AB positive people might be considered universal recipients.

Scientists have worked out a method of stripping A and B antigens from other blood types to create an artificial type O. The Rhesus factor still remains, so Rh- donations are sought allowing transfusions to any blood type.

But what, exactly, is the Rhesus factor? And what happens when man meets woman?

Rhesus Thesis– The Dark Side of Blood

The Rh blood group system (including the Rh factor) is one of thirty-five current human blood typing systems, the most important blood group system after ABO. At present, the Rh system defines fifty blood-group antigens, among which the five antigens C, c, E, e, and especially D are considered the most significant. Commonly used terms Rh factor, Rh-positive and Rh-negative refer solely to the D antigen. In summarizing the Rh factor,
  • Rh+ means the Rh D antigen is present.
  • Rh− means the Rh D antigen is absent.
Besides its role in blood transfusion, a prenatal blood test can determine blood type of a fetus. As a result, Rh blood grouping determines the risk of hemolytic disease of newborns (erythroblastosis fetalis), emphasizing prevention where possible.

babies Rh±
When the mother is Rh-negative and the father is Rh-positive, the fetus can inherit the Rh factor from the father, making the fetus Rh+ too. Problems can arise when the fetus’s blood has the Rh+ factor and the mother’s blood does not.

An Rh- mother may develop antibodies to her Rh+ baby, not uncommon if dribbles of the baby’s blood mixes with the mother's. The mother's body may respond as if it were allergic to the baby. The mother's body may make antibodies to the Rh antigens in the baby’s blood. This means the mother becomes sensitized. At that point, her antibodies may cross the placenta and impact the baby. Such an attack breaks down the fetus’ red blood cells, creating hemolytic anemia, a low red blood cell count. Severe cases cause illness, brain damage, or even death in a fetus or newborn. Allergen sensitization may occur any time fetus blood combines with the mother’s. Usually an Rh- mother miscarries an Rh+ fetus.
Most of us have offspring without thinking about such a subject, but problems do occur. When I was ten, a classmate’s family had struggled to have another child. They were devastated when attempts ended in perinatal deaths. We kids were saddened for our classmate, a boy we’d never before seen cry. At the time, we were told the problem was one of blood incompatibility. While we children weren’t privy to the particulars, something like the following probably occurred.
When an Rh- mother becomes pregnant with a Rh+ child, the mother’s immune system produces antibodies that attack the fetus’ red blood cells. A first child usually survives because the antibodies don’t appear until late in the pregnancy. However, in subsequent Rh+ pregnancies, antibodies are already in place. Even with extreme intervention, these children can die.

Blood Will Tell

Perhaps you’re writing a Halloween tale or a ghoulish Southern gothic involving a convoluted blood line. If you’re beset how a couple begets, check this handy table.

Blood Type Inheritance by Phenotype
❤︎ blood m o t h e r
blood type O A B AB
f
a
t
h
e
r
O O
    
O  A
    
O
B   
   A
B   
A O  A
    
O  A
    
O  A
B AB
   A
B AB
B O   
B   
O  A
B AB
O   
B   
   A
B AB
AB    A
B   
   A
B AB
   A
B AB
   A
B AB

For example, if Colonel D’Arcy is type A and Miss Annabelle Lee is type O and Baby Willie turns out type B… uh-oh. Oo-la-la as they say in N’Orleans, the colonel’s not the father he thought he was. A new tale is born.

——— Factoids ———

Bloodline Timeline

The type O bloodline was the original, dating back at least 200 000 years and likely two-million or more in ancestral primate lines. One theory suggest other blood types began to diverge as diet changed. Type AB arrived quite recently, only ten centuries ago, although a few researchers suggest an approximate AB date of 1000bc instead of 1000ad.
  • 1000,000 years ago, type O had long been the only type.
  • 100,000 years ago, type A appeared in Western Europe.
  • 10,000 years ago, type B appeared in Eastern Asia.
  • 1,000 years ago, type AB emerged as blood lines mixed.



Two blood cells met and fell in love…

Alas, it was all in vein.

I went trick or treating this year with friends. Good thing I dressed as a zombie… no one could tell it was their blood. My husband died when I couldn’t remember his blood type. I’d jotted A-positive on his donor card, but he kept whispering “Typo.”

My husband died when I couldn’t remember his blood type. As he gasped his last breath, he kept insisting for me to “be positive,” but it’s hard without him. My ex got into a bad accident recently. I told the doctors the wrong blood type. Now he’ll really know what rejection feels like.

Have a safe Halloween!

21 October 2018

B~L~O~O~D !   part 1

Erythrocyte (red blood cell)
Erythrocyte, Red Blood Cell with Type A+B Antigens
by Leigh Lundin

In the spirits of Halloween, SleuthSayers brings you a bloody fine tutorial, the basics of what an author needs to know about blood.

As crime writers, we often deal with blood, splatter, DNA and alleles in fiction and non-fiction. Today, we investigate a bleedin’ serious topic.

A+B antibodies
A+B Antibodies Schematic (Type O blood)
Bloody Detail

Erythrocyte is the technical name for a red blood cell. Scientists describe the shape as a biconcave disc or a toroid without a nucleus, meaning they’re vaguely shaped like a plastic kiddie pool or a fresh out-of-the-pack condom.

The cells contain the pigment hemoglobin that makes erythrocytes appear red. A cell’s primary duty is to carry oxygen from the lungs to other parts of the body and transport carbon dioxide back to the lungs where the breathing process of ‘gas exchange’ takes place.
antigen
An antigen induces an immune response stimulating the production of antibodies. Blood antigens comprise types A and B. Either one, both or neither may appear as part of our blood cells.

epitope
The specific surface features of an antigen type are called epitopes. It’s debatable which is the key and which the lock, so it may be convenient to think of matching antigens and antibodies as jigsaw puzzle tabs. For convenience, our schema employs shapes of letters A and B to represent type A and B antigens.

antibody
Triggered by an immune response, antibodies individually key to epitopes. A particular antibody locks onto the shape of an antigen (A and/or B). Antibodies explain why care is exercised when matching blood donors.
They combine like this.

Blood Type Components and Characteristics
❤︎ ABO ABO blood constituents
blood type O A B AB
Erythrocytes (Red Blood Cells)
Red Blood Cell Antigens
Plasma Antibodies
blood type O A B AB
Blood Type Results Erythrocytes with neither antigen but plasma containing both type antibodies. Erythrocytes with type A surface antigens and plasma with type B antibodies. Erythrocytes with type B surface antigens and plasma with type A antibodies. Erythrocytes with both surface antigens but plasma without either antibody.

M-Mmm, Tasty

If you vampires think your honey’s blood is sweet, you have a point– the ‘A’s and ‘B’s in blood types are sugars. Moreover, under an SEM (scanning electron microscope), antigens lend red blood cells a sugary gumdrop look, quite unlike the glossy renderings we usually see.

Types A, B, and AB feature antigens on the surfaces of their cells. Notice how antibodies are ‘keyed’ to lock onto a particular type of antigen, kind of a socket. Antibodies in plasma can attack the wrong type antigens introduced into the blood stream.

Mayhap you feel it’s better to giveth than to receive. Not to be sanguine about these matters, we practice safe blood-letting. To help take the ‘ick’ out of ichor, following is a convenient Béla Lugosi table of tasty platelets for those special moments.

Simplified Blood Type Transfusions by Phenotype
❤︎ blood r e c i p i e n t
blood type O A B AB
d
o
n
o
r
O
A

B

AB



This explains why blood donations are carefully matched. A person with, say, type B antibodies in the plasma can’t mix blood with type B antigens (blood type B or AB): Only type A or O will serve. For practical purposes, a type O donor can give blood to everyone.

Contrarily, an AB- patient can receive from nearly anyone. Because of AB antigens, an AB donor can give blood only to another AB recipient.

——— Factoids ———

Bleeding Blue

Famously, Mr. Spock exhibited faintly green skin, purportedly because Vulcan blood flowed with copper-based hemocyanin rather than iron-based hemoglobin. Beyond Star Trek, other blood colors can be found. In fact, you’ve likely eaten some of them.

Creature copper carriers include shrimp, lobsters, certain crabs, some snails, crayfish, and squid. Octopuses are known for their copper-protein blood, albeit blue rather than green.

The New Guinea skink bleeds green, not because of copper, but because of staggering levels of biliverdin and bilirubin. The ocellated icefish, with neither iron or copper, carries clear blood in its veins.

Blue Bloods… and Green

Mention ‘blue bloods’ today and people think police. In centuries past, the term connoted nobility. Initially, ’sangre azul’ referred to Spanish royalty, whereupon the phrase spread throughout Europe. But why blue?

Serfs, slaves, and commoners typically labored outdoors in fields and forests, accumulating muscles, thicker skin, and tanned flesh. Such ‘rednecks’ looked markedly different from the aristocracy, usually known for their pale, sunless skin revealing blue veins.

Two other hypotheses about royal blue bloods prove difficult to verify. One suggestion premised that royalty often suffered from hæmophilia, rendering the skin and veins even paler. A somewhat more intriguing idea set forth the notion that a lifetime of exposure to silver serving dishes, wine cups, and table utensils, may have given the skin a pale blue cast.

green Leigh
[On a personal note, during school breaks in my teens, I experienced considerable exposure to copper. During those summers, I literally sweated green. Notice the pointy ears? The Frankenstein flair?]



Tomorrow, grab that sphygmomanometer. We’re bringing you more bloody information.