Pure cell populations

Key Words Mieroarrays gene expression RNA amplification laser capture mierodisseetion eaneer stem eell theory pure cell populations diagnostics prognostics... 

Laser Capture Microdissection (LCM) is a technique for isolating pure cell populations from a heterogeneous tissue section or cytological preparation through direct visuahzation of the cells. This technique is applicable to molecular profiling of diseased and disease-free tissue, permitting correlation of cellular molecular signatures with specific cell populations. DNA, RNA, or protein analysis may be performed with the microdissected tissue by any method with adequate sensitivity. 

The fields of genomics and proteomics have been enhanced hy cellular isolation techniques such as Laser Capture Microdissection (LCM), which enables the isolation and molecular investigation of pure cell populations through direct... 

Perrin FE, Boisset G, Lathuiliere A, Kato AC. Cell death pathways differ in several mouse models with motoneurone disease Analysis of pure motoneurone populations at a presymptomatic age. J Neurochem 2006 98(6) 1959-1972. 

To be retained, cell population retention ratio (R) (i.e., species velocity to average flow velocity ratio) must be <1. As already described, cells shouldi not be eluted according to a pure steric elution mode whose R, for a monodisperse population of size a, is... 

Dissociated brain cells from newborn rat cultured for 24 days on a plastic surface developed into a pure glial cell population (Fig. lA). In agreement with previous observations (43) the neuronal cells degenerated during the first 2 days and some oligodendrocytes survived for about a week. On the other hand, the flat polygonal shaped cells multiplied actively and formed a monolayer within 2 weeks. The cells contained in these astrocyte primary cultures were identified by their positive immunoreaction with anti-GFAP antiserum (38, 39). As shown in Fig. IB,... 

The reason for this varied behaviour is not difficult to find. A population of bacteria does not possess the uniformity of properties inherent in pure chemical substances. This fact, together with the varied manner in which bactericides exert their effect and the complex nature of the bacterial cell, should provide adequate and satisfying reasons why the precise theories of reaction kinetics should have failed to explain the disinfeclion process. 

On the other hand, more recent studies have been designed to evaluate these hypotheses as they relate to (1) natural communities as contrasted to pure cultures, (2) cell densities more characteristic of natural ecosystems than those bacterial densities commonly used in tests of pure cultures, (3) synthetic compounds acted on by only a few rather than a diversity of microbial genera or species, and (4) compound concentrations which are characteristic of environmental pollutants rather than organic nutrients included in culture media. In general, all these explanations are related mainly to (1) proliferation of small populations, (2) presence of toxins, (3) predation by protozoa, and (4) appearance of new genotypes [ 101,104,106 -108,110,111 ]. 

In summary, these three approvals with the noncytotoxic monoclonal antibodies demonstrated activity based on survival (Avastin), TIP in an enriched population (Avastin in renal cell cancer), a pure response with endpoint (Campath), and a clever response rate to a combination vs. a reference point response rate with that new agent alone (Cetuximab). 

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