Premenstrual dysphoric disorder (PMDD) is a severe form of premenstrual syndrome (PMS), afflicting 3% to 8% of women. It is a diagnosis associated primarily with the luteal phase of the menstrual cycle. Up to one-third of women diagnosed with PMDD report residual symptoms into the first 2 or 3 days of the follicular phase.
{ Wikipedia | Continue reading }
blood, health | December 15th, 2011 10:52 am
How does inheritance of blood types work?
There are three blood genes: A, B, and O. (I’m going to ignore the + and - part of this.) A and B are dominant, and O is recessive. You inherit one blood gene from your mother and one from your father. The combination of genes determines your blood type. There are four possibilities: A, B, AB, and O. Here’s how it works:
A + A = A
A + O = A
A + B = AB
B + B = B
B + O = B
O + O = O
{ The Straight Dope | Continue reading }
The Rh (Rhesus) blood group system (including the Rh factor) is one of the currently 30 human blood group systems. It is clinically the most important blood group system after ABO. The Rh blood group system currently consists of 50 defined blood-group antigens, among which the 5 antigens D, C, c, E, and e are the most important ones. The commonly-used terms Rh factor, Rh positive and Rh negative refer to the D antigen only.
An individual either has, or does not have, the “Rhesus factor” on the surface of their red blood cells. This term strictly refers only to the most immunogenic D antigen of the Rh blood group system, or the Rh- blood group system. The status is usually indicated by Rh positive (Rh+, does have the D antigen) or Rh negative (Rh-, does not have the D antigen) suffix to the ABO blood type.
{ Wikipedia | Continue reading }
blood | September 12th, 2011 3:25 pm
I’m going to tell you a little story about a menstruating nurse.
Dr. Bela Schick, a doctor in the 1920s, was a very popular doctor and received flowers from his patients all the time. One day he received one of his usual bouquets from a patient. The way the story goes, he asked one of his nurses to put the bouquet in some water. The nurse politely declined. Dr. Schick asked the nurse again, and again she refused to handle the flowers. When Dr. Schick questioned his nurse why she would not put the flowers in water, she explained that she had her period. When he asked why that mattered, she confessed that when she menstruated, she made flowers wilt at her touch.
Dr. Schick decided to run a test. Gently place flowers in water on the one hand… and have a menstruating woman roughly handle another bunch in order to really get her dirty hands on them.
The flowers that were not handled thrived, while the flowers that were handled by a menstruating woman wilted.
This was the beginning of the study of the menstrual toxin, or menotoxin, a substance secreted in the sweat of menstruating women.
{ Scientific American | Continue reading }
photo { Andres Marroquin Winkelmann }
Botany, blood, science | September 10th, 2011 7:32 pm