en.aazsante.fr

The Largest Portal Of Health And Quality Of Life.

Stem Cells: Understand How They Are Used

Stem Cells: Understand How They Are Used

Stem cells are cells that have the ability to self-renew, that is, to give rise to other stem cells equal to it, and which also have the potential to become other cells

To better understand the concept, we must take into account that the human body is made up of a trillion cells and some of them have specific functions. An example is the neurons, cells of the nervous system, that have different performance of the cells that make up the muscles. We say that these cells with specific functions are differentiated cells

However, there are the so-called stem cells that do not yet have a defined specification in the body and can transform into other cell types. This potential has been used to create different types of treatments.

Stem Cell Types

Not every stem cell can turn any type of differentiated cell. Therefore, they are classified according to this potential. They are three types: Totipotent: they are the original cells of the embryo, which has the potential to become both cells of the body and to form extra-embryonic tissues (such as the placenta, for example). They are the cells that give birth to the embryo at the beginning of gestation. Pluripotent: cells that can become any tissue of the body, but do not form extra-embryonic structures. They are found only in the embryo in early stages of multipotent formation: they are adult stem cells, which lose the potential to become any type of cell, but still manage to differentiate into a wide range of differentiated cells. Many types of multipotent stem cells remain in the human organism when it is already developed (ie, from birth, even though they are called adults) while totipotent and pluripotent stem cells are found in many tissues of the body. found only in the embryo. Among the multipotents, there are two more well-known types:

  • Mesenchymal: stem cells are able to differentiate into solid tissue cells, such as muscles, bones, cartilage and fat. However, depending on where they originate, they differ in distinct cell types.
  • Hematopoietic: stem cells present in blood and bone marrow, which are only capable of differentiating into blood cells (red blood cells, white blood cells , etc.).
  • In addition, scientists today are able to transform already differentiated cells into pluripotent stem cells, which have the potential to transform into any type of cell (except extra-embryonic tissues) - are so-called induced pluripotent stem cells . This process is called cell reprogramming.

Uses of stem cells

  • Stem cells are currently used in cell therapies as well as for the creation of research models for understanding diseases and drug development. Here are some approved and developing uses of stem cells.
  • Approved uses of stem cells

Hematopoietic stem cell transplantation:

Also known as bone marrow transplantation, this is the oldest use of stem cells. When the transplant is done, the idea is just to replace these stem cells, so that the new cells produced by the bone marrow are healthy. This treatment is used for diseases such as acute leukemia, chronic myeloid leukemia, chronic myelomonocytic leukemia, lymphomas, severe anemias, congenital anemia, hemoglobinopathies, congenital immunodeficiencies, multiple myeloma, hypocellular myelodysplastic syndrome, severe combined immunodeficiency, osteopetrosis, primary myelofibrosis, myelodysplastic syndrome undergoing transformation, thalassemia major, among others.

Lipoenxertia without reabsorption:

In some countries the plastic procedures of lipoenxertia (in which the fat of the body is grafted in other regions) has fat enriched with stem cells. This prevents the reabsorption of this fatty tissue, a process that occurs due to an understanding of the body that the fat is "out of place" and needs to be reallocated. Stem cells reduce the chances of resorption by up to 90%.

Research using stem cells Medications using stem cells:

There are already some medicines that use stem cells in cell therapies. The first to be approved for commercialization in the world was Prochymal® (remestemcel-L), already approved in Canada, South Korea, New Zealand and Japan and in the process of evaluation in the United States. It has potential to be used in the treatment of some diseases, such as Crohn's disease, acute myocardial infarction, COPD and diabetes, among others, with studies still in the initial phase. Bone reconstruction in cleft lip and palate:

Hospital Sírio-Libanês (in São Paulo), in partnership with Hospital Infantil Menino Jesus, have conducted a research using milk stem cells for bone reconstruction in children with cleft lip and palate (popularly known as cleft lip). When the fissure engulfs the bone in the alveolar region and / or palate (roof of the mouth), it is usually necessary to make a graft with the hip bone, which causes postoperative pain. However, the research uses stem cells to stimulate bone remodeling on the spot. In addition, they stimulate these cells with laser applications, which makes the process even faster.

Understanding autism spectrum disorders: Brazilian studies also study autism spectrum disorders with the help of stem cells . In this case, the purpose is not to use them for treatment in itself, but to help the specialists to understand better how the neurons of the autistics work. To do so, they do cell reprogramming of cells from the tooth pulp or blood cells of people with autism, turning them back into pluripotent cells (induced pluripotent cells). Then, these cells are induced to become neurons. With this, it is possible to reproduce exactly how the neurons of children with and without autism are. Researchers are testing how to use stem cells to help the pancreas recover its function of producing insulin, lost ability. by people with type 1 diabetes. They are injecting stem cells into capsules that are placed in the pancreas and perform the functions of the beta cells of that organ without being attacked by the immune system.

Treatment of macular degeneration: Recent studies conducted in the United States have treated patients who had lost vision with macular degeneration or Stargardt's disease . In it, the scientists differentiated stem cells into cells of the retinal pigment epithelium and applied them to patients who showed significant improvements, even in more advanced cases.

Cancer treatment: Some studies in the UK have looked at ways to turn stem cells into cancer-destroying cancer-destroying potentials. To do so, scientists activate the TRAIL gene in these cells, which makes them similar to immune cells. These cells become attracted to the tumors and cause tumor cells to "commit suicide". For the time being this therapy was only studied in rats, but managed to cure some of them completely from lung cancer.Organ Creation for Transplantation:

Many scientists study how to create whole organs by directing stem cells to differentiate into tissue for specific organs. If the patient's own cells are used, there is no risk of rejection of this new organ. However, the challenge of this line of research is to make the cells differentiate into different tissues that can make up the same organ, since they are complex structures. Where Stem Cells Are Found

Cells embryonic stem cells (totipotent and pluripotent) are found only in embryos and can often be withdrawn from discarded embryos in in vitro fertilization processes (a process that has already caused controversy and discussion since it is not established if these embryos are alive) Multipotent stem cells can be removed from various tissues in the body. See the most common regions for each subtype of these cells:

Mesenchymal cells can be removed from the milk teeth, the umbilical cord wall or adipose tissue Hematopoietic cells are usually removed from the bone marrow or from the umbilical cord blood.

How Stem Cells Are Stored With so many therapies under development, many people have stored stem cells to conserve the resource in the future. In general, this storage is done by freezing. The cells are collected from their region of origin (the collection changes according to the origin of the cell) and taken to the laboratory in a culture medium, which prevents them from being contaminated by bacteria. In the laboratory the stem cells are separated, multiplied and then stored in tanks with liquid nitrogen at - 196 ° C.

See below how each type of stem cell is collected:

Milk tooth

Milk tooth cells are usually not removed from a tooth that has already fallen. This is because this tooth comes in contact with bacteria and also has been for some time without receiving blood, which can cause the death of the cells. Generally speaking, parents who wish to store stem cells from their children's milk teeth should take them to a dentist accredited with this type of treatment. He will evaluate the teeth that still conserve one or two thirds of the root through an x-ray and then mark the extraction of that tooth. After extraction, the tooth will be placed in a special culture medium and taken to the laboratory.

  • Umbilical cord cells
  • Umbilical cord cells are removed soon after delivery when the baby is already under the care of the pediatrician . The blood should be collected shortly after the cord is cut, and the wall cells can be stored soon after. It is okay to make both stores in the same operation.

Bone marrow cells

Bone marrow cells can be removed in two ways: one is through a puncture in the bone of the pelvis (made through the buttocks ). The procedure lasts 60 minutes and is done with anesthesia, with observation after the end.

Another form is withdrawal through the vein, in which the donor takes a medicine for five days, which increases the production of stem cells. On the sixth day, the blood is filtered by a machine, which isolates the stem cells. The process lasts four to six hours and the medicine can cause some side effects as a side effect.

Adipose tissue cells

Adipose tissue cells can be removed after some procedure (such as liposuction or even after a cesarean delivery, where the doctor takes the cut to remove some fat). In addition, the procedure can be done through a simple biopsy in a doctor's office.

Who can take advantage of stem cell therapies?

When a stem cell is stored, it is for the purpose of using it future in someone. But the people who can benefit from these cells vary by cell type:

Mesenchymal Stem Cells

In the case of mesenchymal cells, current studies are done using the patient's own stem cells. This is because the markers that indicate the compatibility of such a stem cell with the recipient are not known.

Hematopoietic stem cells

Hematopoietic stem cells, however, are not normally used in the stem cell itself. donor. This is because some diseases, such as leukemia, occur due to genetic problems, which will certainly be present in the cells of the umbilical cord of the sick person. In these cases, it is safer to use the hematopoietic stem cell from a healthy donor.


Confirmed the first death due to yellow fever in RJ

Confirmed the first death due to yellow fever in RJ

The State of Health of Rio de Janeiro confirmed the first death due to wild yellow fever in the region, with transmission within the State. Exams pointed to positive results for the virus in two men: one died last Saturday (11) and the other is still hospitalized. Both were residents of the rural area of ​​the municipality of Casimiro de Abreu (Coastal Baixadas Region) and had no history of travel to other areas affected by the disease.

(Health)

Kate Middleton presents pregnancy complication due to hyperemesis gravidarum

Kate Middleton presents pregnancy complication due to hyperemesis gravidarum

Kate Middleton is recently announced that she is expecting her third son. The Duchess of Cambridge is already the mother of four-year-old George and two-year-old Charlotte, the fruit of her marriage to Prince William. Despite the good news, Kate's health worries the British crown. This is because she suffers from hyperemesis gravidarum.

(Health)