Genetherapy

Cells recognize one another because of the saccharides attached to cell surfaces. 

They  are present usually as oligosaccharides associated through covalent links to lipids and/or proteins forming Glycoconjugates. The lipid or protein part is integrated into the cell membrane structure, with the saccharide part towards the external membrane surface.

Membrane carbohydrates  (2-10% of the membranes) are on the extracellular surface bounded to lipids or proteins of the membrane, forming glycoconjugates that serve as docking sites in cell recognition, adhesion and receptor action. These sugars include mainly glucose, galactose, mannose, fucose, N-acetyl galactosamine and  N-acetyl glucosamine.

The different kinds of Glycoconjugates include:

Proteoglycans: In the Proteoglycans, the Glucosaminoglycan moety forms the greater fraction of the molecule (tipically a proteoglycan consists of 95 % of carbohydrates) and is the main site of biological activity, providing multiple binding sites. They are found mainly in the extracellular matrix. They are major components of connective tissue.

Glycoproteins: Membrane bound glycoproteins participate in a wide range of cellular phenomena, including cell recognition, cell surface antigenicity, etc. In the glycoproteins, the majority of the molecule consist of proteins; they have one or more oligosaccharides attached to a protein, and they usually are branched and do not have serial repeats, so they are rich in information, forming highly specific sites for recognition and high affinity binding by other proteins

Glycolipids: are membrane lipids in which the hydrophilic head groups are oligosaccharides.

 As in glycoproteins, glycolipids  act as specific sites for recognition by carbohydrate binding proteins.  The four types of human RBC have different oligosaccharides (antigens) in their cell membranes. Blood groups depends on the gangliosides (a kind of sphingolipid) in the surface of the RBC .

Where do the visits come from today?

The Dietary Reference Intake can be defined  a system of nutrition recommendations that estimates the amounts of nutrients required to prevent deficiencies and maintain optimal Health.

The DRI includes some concepts that sometimes are used as equivalents, when they are not. In other cases, the same concept receive different names, depending of the source of the article you are reading.

DRIs consists of four dietary reference standards:

1.- Estimated Average Requirement (EAR): Average daily nutrient intake level estimated to meet the requirement of one half of the healthy individuals in a specific age and gender group.

 2.- Recommended Dietary Allowance (RDA): Average daily Dietary intake level that is sufficient to meet the nutrient requirements of nearly all (97-98%) individuals (EAR+2DS) on each life state and gender group. It is approximately 20 % higher than the EAR. RDA are printed in food labels in the United States and Canada.  (The definition of RDA is similar to the definition of  Recommended Nutrient Intake (RNI)  used by the World Health Organization and other international organizations).

 3.- Adequate Intake (AI): Estimation of nutrient intake in healthy people (used when EAR and RDA are not known)

 4.- Tolerable Upper Intake Level (UL): Highest average daily intake level from food, water and supplements that is likely to pose no risk of adverse health effect from excess in almost all apparently healthy individuals in an age and gender specific population group. (This concept is important mainly in relation to nutritional supplements, since the ingestion of natural foods is regulated in the body through mechanisms of absorption and excretion), In absence of observations of known adverse effects, it is used a default value of 10 times de Recommended Dietary Allowance.

More information about these reference standards can be found at:

Dietary Reference Intake

Reference dialy Intake 

 Interactive DRI for health care professionals

 Yates, A.A.: Dietary Reference Intakes –What is new and how to use them (Power point presentation)

Who Experts Committee:

Vitamin and Mineral requirements in human nutrition

World Health Organization, 2004

A 70 year-old English lady that lives alone is admitted to the hospital for evaluation of a leg wound that is not healing properly. The patient also complains of pain in muscle and bones. On the examination, you find some hemorrhagic lesions in the skin, including ecchymosis in buttocks and both legs and petechiaes in other areas of the skin. The nails show splinter hemorrhages. When asked about her dietetic habits, the patient refers that she is too old to eat so much, so she has a very frugal lunch and dinners based mainly in tea and toasts.

Laboratory examinations show normal blood coagulation tests and Hemoglobin of 9.8 g/dL

The treatment for the condition described above should consist mainly in the administration of the following vitamin:

a)     Ascorbic Acid

b)     Biotin

c)      Folic Acid

d)     Pantothenic acid

e)     Niacin

f)       Vitamin B1

g)     Vitamin B2

h)    Vitamin B6

i)       Vitamin B12

j)       Vitamin D

k)     Vitamin E

l)       Vitamin K

Mouse Islet of Langerhans immunostained for Glucagon

Assume that you find a patient with a glucagon-secreting pancreatic tumor (glucagonoma). Which one of the following is most likely to result from hyperglucagonemia?

a)     Decreased lipolysis

b)     Hyperglycemia

c)      Increased muscle protein synthesis.

d)     Increased liver glycolytic rate

e)     Increased glycogenesis

In this representation of Krebs Cycle, each reaction, is marked with a number.

Select the two reactions that require the participation of Flavoproteins.

a)     1 and 3

b)     2 and 4

c)      3 and 5

d)     4 and 6

e)     5 and 7

f)       6 and 8

The International Association for Medical Education in Europe (AMEE) has released  a provisional Agenda for its General Assembly that will be held in Malaga, Spain, on September 1^st.

Palacio de los Congresos, Malaga

General Assembly 2009

Palacio de Ferias y Congresos de Málaga, Málaga, Spain

Tuesday 1 September: 1300-1400 hrs

Draft Agenda

This compound dissipates the electrochemical gradient between the intermembrane space and the mitochondrial matrix, consequently the electron transportation takes place but not the synthesis of ATP

a)     Antimycin B

b)     Carbon Monoxide

c)      Oligomycin

d)     Rotenone

e)     UCP

After Vincent genetic test:

Vincent: What about the interview?

Dr. Lamar: That was it.

Basically GATTACA  is a movie about a future where your DNA becomes your Curriculum Vitae.

What does “GATTACA” means?

In the movie, it is the name of the facility where the action occurs, and apparently, it was the better way that was found by the creators of the movie for arranging the four “bases”  in the DNA (Adenine, Guanine, Cytosine and Thymine) in such a way that it sounds like a name.

The title sequences highlight these letters that represent the nitrogen bases in the DNA:

GATTACA main message is:

“There is no gen for the human spirit”

For additional information about this movie, please visit the Moviecular Biology page.

SOME QUOTES FOR TODAY:

One night a father overheard his son pray: Dear God, Make me the kind of man my Daddy is. Later that night, the Father prayed, Dear God, Make me the kind of man my son wants me to be.

Sherman made the terrible discovery that men make about their fathers sooner or later… that the man before him was not an aging father but a boy, a boy much like himself, a boy who grew up and had a child of his own and, as best he could, out of a sense of duty and, perhaps love, adopted a role called Being a Father so that his child would have something mythical and infinitely important: a Protector, who would keep a lid on all the chaotic and catastrophic possibilities of life.
Tom Wolfe
The Bonfire of the Vanities

There are fathers who do not love their children, but there is no grandfather who does not adore his grandson.
Victor Hugo 

“I won’t lie to you, fatherhood isn’t easy like motherhood”

Dan Castellaneta

By the time a man realizes that maybe his father was right,
he usually has a son who thinks he’s wrong.
Charles Wadsworth 

“A father is a banker provided by nature.”
- French Proverb

The child had every toy his father wanted.”
- Robert C. Whitten

LEONTINE: An only son, Sir, might expect more indulgence
CROAKER: An only father, Sir, might expect more obedience
- Oliver Goldsmith 1728-1774 from The Good Natured Man

It is admirable for a man to take his son fishing, but there is a special place in heaven for the father who takes his daughter shopping.
John Sinor

We think our fathers fools, so wise we grow.
Our wiser sons, no doubt will think us so.
- Alexander Pope

When I was a boy of 14, my father was so ignorant I could hardly stand to have the old man around. But when I got to be 21, I was astonished at how much the old man had learned in seven years.

The father is always a Republican toward his son, and his mother’s always a democrat.
- Robert Frost

There are three stages of a man’s life: He believes in Santa Claus, he doesn’t believe in Santa Claus, he is Santa Claus.

Life was a lot simpler when what we honored was father and mother rather than all major credit cards.
- Robert Orben

In this representation of Krebs Cycle, each reaction is marked with a number.  The reactions where NAD+ is reduced to NADH.H+ are those marked with the numbers:

a)     1,3 and 4

b)     3,4 and 5

c)      3,4 and 6

d)     3,4 and 8

e)     5,6 and 7

f)       4,5 and 6