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Posted by on May 18, 2013 in Explain To Me, In progress |

Explain To Me: Immunohistochemical Detection

This post is still under construction.

Disregard its content, if any, as it only contains raw reference material for the future post.

Do you have any questions about Immunohistochemical Detection? Then please head for the “Why Is It All So Confusing?” forum and we'll try and help.

Need post header picture
explain using stuff in ImunCytoChem.pdf

Immunohistochemistry is a method of detecting the presence of specific proteins in cells or tissues. It is widely used in basic research to understand the distribution and localization of biomarkers and differentially expressed proteins in different parts of a biological tissue.

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Posted by on May 17, 2013 in In progress, Uncategorized |

What is the Difference Between SM and MCAS?

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Posted by on May 17, 2013 in Genetics, In progress |

How To Use The Genetics Association Database?

This post is still under construction.

Disregard its content, if any, as it only contains raw reference material for the future post.

 If you have any genetics questions, head for the Ninja Mutant Mastos (genetics) forum and ask away. 

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Explain use of
http://geneticassociationdb.nih.gov/cgi-bin/index.cgi

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Posted by on May 15, 2013 in In progress |

The Histamine Lifecycle

Histamine intolerance can develop through both increased availability of histamine and impaired
histamine degradation. Underlying conditions for increased
availability may be an endogenous histamine overproduction
caused by allergies, mastocytosis, bacterias, gastrointestinal
bleeding, or increased exogenous ingestion of histidine or histamine
by food or alcohol. Other biogenic amines, such as putrescine,
may also be involved in displacing histamine from its
mucosal mucine linkage, which results in an increase of free
absorbable histamine in circulation. However, the main cause of
histamine intolerance is an impaired enzymatic histamine degradation
caused by genetic or acquired impairment of the enzymatic
function ofDAOor HNMT. Gastrointestinal diseases with
altered enterocytes also may cause decreased production ofDAO
(17, 33, 39). Yet another cause can be competitive inhibition of
histamine degradation ofDAOby other biogenic amines, alcohol
(7–9), or drugs (10, 12, 40). Acquired histamine intolerance may
be transient and therefore reversible after the elimination of
causes, such as by discontinuing DAO-blocking drugs. DAO
inhibits the transepithelial permeation of exogenous histamine
(41, 42), and impaired DAO activity results in increased enteral
histamine uptake with consequent increased plasma histamine
concentrations (10, 41) and corresponding symptoms. Increased
amounts of histamine metabolites may also inhibit HNMT, the
second enzyme metabolizing histamine (6, 43).

Thus, histamine intolerance seems to be
acquired mostly through the impairment ofDAOactivity caused
by gastrointestinal diseases or through the inhibition ofDAO,but
the high interindividual variations in the expression of DAO in
the gut and the association of SNPs in the DAO gene with gastrointestinal
diseases provide evidence for a genetic predisposition
in a subgroup of patients with histamine intolerance (27).

Histamine and other biogenic amines are present to various
degrees in many foods, and their presence increases with maturation
(1, 72)

In addition to histamine-rich food, many foods such as citrus
foods are considered to have the capacity to release histamine
directly from tissue mast cells, even if they themselves contain
only small amounts of histamine

Alcohol, especially red wine, is rich in histamine and is a
potent inhibitor of DAO

The relation between the ingestion
of wine, an increase in plasma histamine, and the occurrence
of sneezing, flushing, headache, asthma attacks, and other anaphylactoid
reactions and a reduction of symptoms by antihistamines
has been shown in various studies

Histamine and drugs
The effect of drugs as specific DAO inhibitors and their capacity
to induce histamine intolerance have been shown in various
studies with human placental DAO and in animal experiments
(10, 40, 97, 98).Aclinically relevant activity via histamine
release or inhibition ofDAOhas been observed for various drugs
(10, 40, 97, 98) (Table 5). Therefore, the intake of drugs,
especially long-term medication, should be considered in interpretation
of histamine intolerance symptoms and DAO concentrations.

Reduced DAO activity has also been
shown in patients with chronic urticaria as a typical histaminemediated
disease (60) combined with a reduced tolerance for
infused histamine (16) and an improvement of urticaria by maintaining
a histamine-free diet (103).

Reduction of both
the symptoms of histamine intolerance and the severity score
of atopic dermatitis (SCORAD) has been shown in a subgroup
of patients with AE and low DAO serum activity who were
following a histamine-free diet for 2 wk (111).

Therapy is based on the consequent conduction of a histaminefree
diet. Alcohol and long-ripened or fermented (and therefore
histamine-rich) food, such as aged cheese, cured meat, and yeast
products; histamine-rich food, such as spinach or tomatoes; or
histamine liberators, such as citrus fruit, should be avoided (65,
134); the histamine-free diet can be complemented with adjuvant
administration of H1 and H2 antagonists. Most antihistamines
have no influence on DAO activity, although inhibition of DAO
by cimetidine and dihydralazine and increased activity by diphenhydramine
have been observed (97). In patients consuming
a strictly histamine-free diet, no additional benefit due to an
intake of antihistamines could be observed

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Posted by on May 15, 2013 in In progress |

What is HMNT and DAO?

This post is still under construction.

Disregard its content, if any, as it only contains raw reference material for the future post.


Video of the German guy + video transcript of the whole series !! YAY!

histamine-N-methyltransferase (HNMT) the second most important enzyme inactivating histamine, is a cytosolic protein (30), which can convert histamine only in the intracellular space of cells. (DAO works on extracellular histamine)

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Posted by on May 15, 2013 in In progress |

What Is Diamine Oxidase?

The main enzyme for metabolism of ingested histamine is diamine oxidase (DAO) (1–5). An impaired histamine degradation based on a reduced DAO activity and the resulting excess of histamine may cause numerous symptoms mimicking an allergic reaction. In mammals, DAO expression is restricted to specific
tissues; the highest activities are shown for small bowel and
colon ascendens (4, 5, 33) and for placenta and kidney (28, 31).
Lower DAO activity has been discussed as a potential indicator
of intestinal mucosa damage in inflammatory and neoplastic
diseases

Extracellular scavenger of histamine and other diamines by
oxidative deamination of the primary amino group of
histamine

pdf is here http://ajcn.nutrition.org/content/85/5/1185.full.pdf

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