At that time, because the retrovirus had only been recently identified as the AIDS virus, much of the pooled factor VIII concentrate supply in hospitals was tainted because doctors did not know how to test for the disease, and donors often did not know they were infected or that blood was a factor in the transmission of the virus.

Hemophilia A is an inherited deficiency in clotting factor VIII, which causes increased bleeding and usually affects males.

However, mild hemophilia A ( and B ) is known to occur heterozygous females due to X-inactivation, so it is recommended that levels of factor VIII and IX be measured in all known or potential carriers prior to surgery and in the event of clinically-significant bleeding .< sup >: 1701 </ sup >

5-10 % of patients with hemophilia A are affected because they make a dysfunctional version of the factor VIII protein ( qualitative deficiency ), while the remainder are affected because they produced factor VIII in insufficient amounts ( quantitative deficiency ).< sup >: 1700 </ sup > Of those who have severe deficiency ( defined as < 1 % activity of factor VIII ), 45-50 % have the same mutation, an inversion within the factor VIII gene that results in total elimination of protein production .< sup >: 1700 </ sup > However, since both forms of hemophilia can be caused by a variety of different mutations, initial diagnosis and classification is done by measurement of protein activity rather than by genetic tests, though genetic tests are recommended for testing of family members once a known case of hemophilia B is identified .< sup >: 1700-1701 </ sup >

Diagnosis of haemophilia A also includes a severity level which can range from mild to severe based on the amount of active and functioning factor VIII detected in the blood.

The two most common differential diagnoses are haemophilia B ( also known as Christmas disease ) which is a deficiency in Factor IX and von Willebrand Disease which is a deficiency in von Willebrand factor needed for the proper functioning of Factor VIII.

Mild hemophiliacs often manage their condition with desmopressin, which releases stored factor VIII from blood vessel walls.

A particular therapeutic conundrum is the development of " inhibitor " antibodies against factor VIII due to frequent infusions.

These develop as the body recognises the " normal form " factor VIII as foreign, as the body does not have its own " copy ".

In order to create a tumor necrosis factor ( TNF ) knockout, an exon containing the nucleotides 3704-5364 was removed from the gene.

For example, the gene encoding Insulin-like growth factor 2 ( IGF2 / Igf2 ) is only expressed from the allele inherited from the father.

The former is the determinant factor for the number of gene lineages, zygosity mutations and founding haplotypes present in today's Indigenous Amerindian populations.

Degradation of Aux / IAA proteins derepresses transcription factors in the auxin-response factor ( ARF ) family and induces ARF-directed gene expression.

Depending on the transcription factor, the transcription of the adjacent gene is either up-or down-regulated.

Another example is the transcription factor encoded by the Sex-determining Region Y ( SRY ) gene, which plays a major role in determining gender in humans.

For example, in a negative feedback loop, the transcription factor acts as its own repressor: If the transcription factor protein binds the DNA of its own gene, it will down-regulate the production of more of itself.

* TNFRSF10B, tumor necrosis factor receptor superfamily, member 10b, a human gene

* Activating transcription factor, a class of DNA-binding proteins that regulate gene transcription

* Artificial transcription factor, a type of engineered protein used in gene modulation

These studies have contributed much to our understanding of the regulation of gene expression, transcription factors, and the sigma factor subunits of RNA polymerase.

Biological importance of a polymorphic CA sequence within intron I of the epidermal growth factor receptor gene ( EGFR ) in high grade central osteosarcomas.

Since specific gene therapies cannot readily be used to treat a significant fraction of patients with retinal dystrophy, there is a major interest in developing a more generally applicable survival factor therapy.

narrow down the locus of the human androgen receptor gene ( or a factor controlling the androgen receptor gene ) to somewhere between Xq11 and Xq13 .</ li >

Treatment with alpha tocopherol was found to downregulate the expression of the CD36 scavenger receptor gene and the scavenger receptor class A ( SR-A ) and modulates expression of the connective tissue growth factor ( CTGF ).

One possible factor is an allele ( variant ) of the MAO-A gene which, in interaction with certain life events such as childhood maltreatment ( which may show a main effect on its own ), can influence development of brain regions such as the amygdala and as a result some types of behavioral response may be more likely.

Symptomatic carriers of the gene, while not hemophiliacs themselves, can have symptoms of hemophilia including a lower than normal blood clotting factor that can lead to heavy bleeding.

The Y chromosome is much smaller than the X, and contains a much smaller set of genes that influence ' maleness ', such as the SRY gene for testis determining factor.

Symptomatic carriers of the gene, while not hemophiliacs themselves, can have symptoms of hemophilia including a lower than normal blood clotting factor that can lead to heavy bleeding.

As another example, if genes in two species independently become restricted to the same region of the animals through regulation by a certain transcription factor, this may be described as a case of parallel evolution — but examination of the actual DNA sequence will probably show only divergent changes in individual base-pair positions, since a new transcription factor binding site can be added in a wide range of places within the gene with similar effect.

The presence of the SRY gene, located on the Y chromosome and encoding the testis determining factor, determines male sexual differentiation.

This intronless gene encodes a transcription factor that is a member of the SOX ( SRY-like box ) gene family of DNA-binding proteins.

The trade balance is identical to the difference between a country's output and its domestic demand ( the difference between what goods a country produces and how many goods it buys from abroad ; this does not include money re-spent on foreign stock, nor does it factor in the concept of importing goods to produce for the domestic market ).

It produces considerably smaller files ( especially for source code and other structured text ), but at the cost of memory and processing time ( up to a factor of 4 ).

Such analysis produces a factor whether or not it corresponds to a real-world phenomenon, and so caution must be exercised in its interpretation.

A magnification of factor 7, for example, produces an image as if one were 7 times closer to the object.

If the reflectivity is high, resulting in a high Q factor ( i. e. high finesse ), monochromatic light produces a set of narrow bright rings against a dark background.

If the reflectivity is high, resulting in a high Q factor, monochromatic light produces a set of narrow bright rings against a dark background.

A factor of 2 in the numerator produces a shift of one decimal place to the right in the quotient.

Rumen fermentation produces large amounts of organic acids and thus maintaining the appropriate pH of rumen fluids is a critical factor in rumen fermentation.

The current produces a voltage drop in the cage factor of and a slightly higher one in the stator windings.

The endothelium derived hyperpolarizing factor stimulates calcium sensitive potassium channels and / or ATP sensitive potassium channels and stimulate potassium efflux which hyperpolarizes the cell and produces relaxation.

Each of the factor combinations A, B and C produces the same level of output, 10 units.

Milking speed is only minorly related to the quantity of milk the cow produces — milking speed is a separate factor from milk quantity ; milk quantity is not determinative of milking speed.

When plated on Niger or birdseed agar C. neoformans produces melanin, which causes the colonies to have a brown color, and it is believed that this melanin production may be an important virulance factor.

Inflation theory posits that an inflaton field in the first 10 < sup >- 30 </ sup > seconds of the universe produces strong repulsive gravity, and the universe and space-time expand by a factor of 10 < sup > 30 </ sup >.

One of the primary concerns in internal combustion emissions is a factor called the NOx fraction, or the amount of nitrogen / oxygen compounds the engine produces.

Compute the GCD of n with the difference ( or sum ) of a and b. This produces a factor, although it may be a trivial factor ( n or 1 ).

A PTAS is an algorithm which takes an instance of an optimization problem and a parameter ε > 0 and, in polynomial time, produces a solution that is within a factor 1 + ε of being optimal ( or 1-ε for maximization problems ).

A PRAS is an algorithm which takes an instance of an optimization or counting problem and a parameter ε > 0 and, in polynomial time, produces a solution that has a high probability of being within a factor ε of optimal.

Purification of protein from bovine-derived stromal cell supernatants produces a substantially homogeneous factor, free of extraneous materials.

This occurs through activation of dopamine receptors in these areas which produces glutamate release and subsequent elevation of local basic fibroblast growth factor ( bFGF ) concentrations.

Or P may be defined as the midpoint of P < sub > 1 </ sub > and P < sub > 2 </ sub >; this produces the curve generated by the previous curve scaled by a factor of 1 / 2.

In addition to the conscious role people are aware of memory and experience playing in dreaming, unconscious effects such as health of relationships factor into the types of dreams the brain produces.

A magnification of factor 10, for example, produces an image as if one were 10 times closer to the object.