Question: What could cause a stem cell to become isolated?
About the article "Stem cell", section "Identification".

Candidate passages:
Adult stem cell lines isolated from mature tissues are commonly used in stem cell research, as are cells isolated from umbilical cord blood.
However, these cells have a genetic imprint of the host they were taken from, thus limiting their therapeutic use in genetic disorders.
Also, adult stem cells are not totipotent or pluripotent like embryonic stem cells, but rather more specialized cells that are multipotent.
Another source of stem cells is the iPS (induced pluripotent stem) cell.
This process involves reversing the differentiating cell signals that cause a stem cell to specialize.
In this way, a somatic cell can be worked backwards (induced) into a stem cell.
One added advantage of this type of stem cell is that the pluripotent cell has the same DNA as the donor and can be used therapeutically towards that end without painful bone marrow and spinal cord extraction techiques.
It also contributes to pain relief. 
The origin of cancer stem cells is still an area of ongoing research.
Several camps have formed within the scientific community regarding the issue, and it is possible that several answers are correct, depending on the tumor type and the phenotype the tumor presents.
One important distinction that will often be raised is that the cell of origin for a tumor can not be demonstrated using the cancer stem cell as a model.
This is because cancer stem cells are isolated from end-stage tumors.
Therefore, describing a cancer stem cell as a cell of origin is often an inaccurate claim, even though a cancer stem cell is capable of initiating new tumor formation.
With that caveat mentioned, various theories define the origin of cancer stem cells.
In brief, CSC can be generated as: mutants in developing stem or progenitor cells, mutants in adult stem cells or adult progenitor cells, or mutant differentiated cells that acquire stem like attributes.
These theories often do focus on a tumor's cell of origin and as such must be approached with skepticism.
Some researchers favor the theory that the cancer stem cell is generated by a mutation in stem cell niche populations during development.
The logical progression claims that these developing stem populations are mutated and then expand such that the mutation is shared by many of the descendants of the mutated stem cell.
These daughter stem cells are then much closer to becoming tumors, and since there are many of them there is more chance of a mutation that can cause cancer.
Another theory associates adult stem cells with the formation of tumors.
This is most often associated with tissues with a high rate of cell turnover (such as the skin or gut).
In these tissues, it has long been expected that stem cells are responsible for tumor formation.
This is a consequence of the frequent cell divisions of these stem cells (compared to most adult stem cells) in conjunction with the extremely long lifespan of adult stem cells.
This combination creates the ideal set of circumstances for mutations to accumulate; accumulation of mutations is the primary factor that drives cancer initiation.
In spite of the logical backing of the theory, only recently has any evidence appeared showing association represents an actual phenomenon.
It is important to bear in mind that due to the heterogeneous nature of evidence it is possible that any individual cancer could come from an alternative origin.
A third possibility often raised is the potential de-differentiation of mutated cells such that these cells acquire stem cell like characteristics.
This is often used as a potential alternative to any specific cell of origin, as it suggests that any cell might become a cancer stem cell.
Another related concept is the concept of tumor hierarchy.
This concept claims that a tumor is a heterogeneous population of mutant cells, all of which share some mutations but vary in specific phenotype.
In this model, the tumor is made up of several types of stem cells, one optimal to the specific environment and several less successful lines.
These secondary lines can become more successful in some environments, allowing the tumor to adapt to its environment, including adaptation to tumor treatment.
If this situation is accurate, it has severe repercussions on cancer stem cell specific treatment regime.
Within a tumor hierarchy model, it would be extremely difficult to pinpoint the cancer stem cell's origin. 
Brassinolide is a plant hormone.
The first isolated brassinosteroid, it was discovered when it was shown that pollen from rapeseed ("Brassica napus") could promote stem elongation and cell division.
The biologically active component was isolated and named brassinolide. 
The demand for treatments on diseases has sparked a controversy among those involved with stem cell research.
Since stem cells have the ability to differentiate into any type of cell, they offer something in the development of medical treatments for a wide range of conditions.
Treatments that have been proposed include treatment for physical trauma, degenerative conditions, and genetic diseases (in combination with gene therapy).
The hope for a treatment for myelomalacia lies in the hands of stem cell research.
Further treatments using stem cells could potentially be developed thanks to their ability to repair extensive tissue damage.
Much success and potential has been demonstrated from research using adult stem cells.
There are no approved treatments or human trials using embryonic stem cells.
Nevertheless, some researchers are of the opinion that the differentiation potential of embryonic stem cells is broader than most adult stem cells.
Embryonic stem cells can become all cell types of the body because they are Totipotent.
Adult stem cells are generally limited to differentiating into different cell types of their tissue of origin.
However, some evidence suggests that adult stem cell plasticity may exist, increasing the number of cell types a given adult stem cell can become.
In addition, embryonic stem cells are considered more useful for nervous system therapies, because researchers have struggled to identify and isolate from adult tissues.
Embryonic stem cells, however, might be rejected by the immune system - a problem which wouldn't occur if the patient received his or her own stem cells.
Medical scientists believe that these stem cell therapies have the ability to change the treatment of human diseases tremendously.
Stem cell therapies are currently being conducted in patients with bone marrow transplants, used to treat leukemia.
The future use of this treatment looks to be able to treat diseases such as cancer, spinal cord injury, Lou Gehrig's disease, multiple sclerosis, and a number of other muscular conditions. 
Recent studies have shown that there is a decrease in neurogenesis in the hippocampus after irradiation therapy.
The decrease in neurogenesis is the result of a reduction in the stem cell pool due to apoptosis.
However, the question remains whether radiation therapy results in a complete ablation of the stem cell pool in the hippocampus or whether some stem cells survive.
Animal studies have been performed by Monje and Palmer to determine if there is an acute ablation of the stem cell pool.
In the study, rats were subjected to 10 Gy dosage of radiation.
The 10 Gy radiation dosage is comparable to that used in irradiation therapy in humans.
One month after the reception of the dosage, living precursor cells from these rats’ hippocampus were successfully isolated and cultured.
Therefore, a complete ablation of the precursor cell pool by irradiation does not occur otherwise no living precursor cells could be isolated.