Th1 Th2 ; early brain development

[Guest guest]

Regarding your second article. Would this explain why so many spectrum

disordered kids seem to look so different in their second decade of life as

compared with their first? Kathy

[Guest guest]

These cites were sent me in one post.

I'm not implying a connection between the two topics.

This Week in SCIENCE, Volume 287, Issue 5454,

dated February 4 2000, is now available at:

http://www.sciencemag.org/content/vol287/issue5454/twis.shtml

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Manipulating T Cell Types

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T cells can help the immune response generate either a cell-mediated

(type-1) or an allergic (type-2) response. The cytokines that heavily influence

one pathway or another are interleukin-12 (IL-12) and IL-10, respectively.

Ashkar et al. (p. 860) now find that the cytokine Eta-1 (also known as

osteopondin) is critical for directing the increased production of IL-12,

through binding to an integrin, and the decreased production of IL-10,

through binding to CD44. Through the use of mice genetically deficient in

Eta-1, IL-12, or IL-10, the authors found that Eta-1 was necessary to

protect mice from Listeria infections and to aid in granuloma formation.

The effects of Eta-1 on the IL-12:IL-10 ratio provide another possible

therapeutic target for manipulation of the immune response.

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Almost Assembling the Brain

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The development of an organ as complex as the brain depends on a sequence

of precisely controlled events. Is synaptic communication between neurons

a requirement for the proper assembly of the brain? Verhage et al. (p. 864)

describe a new mouse mutant, with a deletion of the munc 18-1 gene, where

neurotransmitter secretion is completely blocked. The brains of these mice

are nevertheless normally assembled, major pathways are present, and

structural elements of synapses form. Neurotransmission seems thus not to

be necessary for synapses to form and connections to be established

initially. At later stages, however, neurons die by apoptosis, tremendous

cell loss occurs, and brain integrity is compromised.