Showing posts with label Cell Biology. Show all posts

Saturday, March 26, 2011

Stem Cell Therapy in India

Stem Cells
Stem cells are the building blocks of our blood and immune systems.

They form the white cells (white blood corpuscles) that fight infection, red cells (red blood corpuscles) that carry oxygen and platelets that promote healing.

Stem cells are present in our bone marrow and they generate new cells throughout our lives.

Other than bone marrow, the blood in the umbilical cord also has stem cells (and this is why the reference to India’s childbirth).

It can be also used as a source of cells for transplants quite like the bone marrow stem cells.

The major advantage is that umbilical cord blood stem cells are easier to gather than stem cells from the bone marrow.

They have the unique ability to regenerate/reproduce into over 200 types of tissues. Above all, such stem cells, collected from the umbilical cord of your child, can be frozen and kept in a bank, which can be used later.

There are two types of stem cells in mammals
- Embryonic stem cells
- Adult stem cells
Stem cells are mainly found in blood from the umbilical cord and the bone marrow
Due to their self-renewing nature, stem cells are very important for treatment of diseases

Importance of stem cells

For a cell to be characterised as a stem cell, it must exhibit the following properties
- Self renewal: the ability to go through numerous cycles of cell division while maintaining the undifferentiated state
- Potency: the capacity to differentiate into specialised cell types
In developing embryos, stem cells can differentiate into all of the specialised embryonic tissues
In adult organisms, stem cells act as a repair system for the body, replenishing specialised cells
Stem cells also maintain the normal turnover of regenerative organs such as blood, skin or tissues
Stem cells can be grown and transformed into specialised cells of various tissues such as muscles and nerves using cell culture
Stem cell treatment holds the potential of transforming human medicine, wherein stem cells introduce new cells into damaged tissue in order to treat a disease or injury
The ability of stem cells to self renew and differentiate offers the potential to replace diseased and damaged tissue without the risk of rejection or side effects
What is special about stem cells compared to other cells in the body (the somatic cells)?

Somatic cells have become specialized for the jobs they have to perform to keep the “body machine” working properly. Stem cells have the ability to become a variety of cell types in a lineage with embryonic stem cells being able to become all cell types. New methods have led to re-programming of cells to be “stem-like” in their behavior, biomarkers, and their ability to become other cell types.

How are Stem Cells stored?

Stem cells, which hold the promise of new cell-based therapies to treat critical medical conditions, have to be effectively stored until it’s time to use them. The method is called cryopreservation: it freezes stem cells at temperatures below -150 o C, by immersing them in nitrogen vapour. But if the cells are to survive this process, they need to be frozen using a protective compound called a cryoprotectant, which is found to be toxic and can cause serious side-effects when administered. Research is on to find alternative, non-toxic compounds as protective agents of a technology which could rid the world of many diseases. In the past few years, it has become a norm to harvest the umbilical cord blood just after birth, as a guarantee of health for the child.

Current stem cell treatments

Currently, stem cell treatment is available to treat the side effects of chemotherapy on cancer patients, such as leukaemia or lymphoma
During chemotherapy most growing cells are killed by cytotoxic agents
These agents kill not only the leukaemia cells but also healthy haematopoietic stem cells in adjacent bone marrows.
Using stem cell therapy, healthy bone marrow stem cells are used to reintroduce healthy stem cells to replace those lost in the treatment

In Jan 2009, the US Food and Drug Administration (FDA) gave clearance to Geron Corporation for the first clinical trials of an embryonic stem cell therapy on humans. The trial will evaluate the efficacy of the drug GRNOPC1 on patients with spinal cord injury

Public stem cell bank

In Europe and in the United States many private stem cell banks like LifeCell operate as dual banks; that is as a private bank where individuals keep their stem cells by paying an amount, and also a public stem cell bank from where anybody can buy stem cells if they can.

LifeCell is India’s first such private stem cell bank, where you can store the umbilical cord of your child for a fee, for future use. They are planning for the first time in the country to have a public stem cell bank also.

Important milestones in stem cell research

1963: Ernest McCullogh (Canada) and James Till (Canada) illustrate the presence of self renewing cells in the bone marrow
1968: Bone marrow transplant between two siblings successfully treats Severe Combined Immunodeficiency (SCID)
1978: haematopoietic stem cells discovered in human blood
1998: James Thomson (USA) derives the first human embryonic stem cell line
2001: Scientists at Advanced Cell Technology (USA) clone first early human embryos for the purpose of generating embryonic stem cells
2006: Scientists at Newcastle University (England) create first every artificial liver cells using umbilical cord blood cells
2008: Robert Lanza and colleagues at ACT create first human embryonic stem cells without destruction of the embryo

India is one of the most advanced nations in the world in terms of their aggressive research and implementation of stem cell therapy. The Indian parliament is debating their laws, but stem cell therapy is currently minimally regulated and is legal. There are numerous diseases that are treated with stem cell therapy in India, ranging from heart disease to cancer and spinal cord injuries.

Overview of stemcell treatments in India

Is stemcell therapy legal in India?

According to the Indian Council of Medical Research, all stem cell therapy in India is considered to be experimental, with the exception of bone marrow transplants. However, the guidelines that were put into place in 2007 are largely non-enforceable. Regardless, stem cell therapy is legalized in India.

Umbilical cord and adult stem cell treatment are considered permissible.

Embryonic stem cell therapy and research is restricted.

Diseases being treated with stemcell therapy in India

The following is a partial list of diseases treated with stem cell therapy in India:

Spinal Cord Injury
Vitiligo
End Stage Liver Disease
Critical Limb Ischemia
Parkinson’s Disease
Psoriasis
Avascular Necrosis
Motor Neuron Disease (MND)
Alzheimer's
Cancer
Arthritis
Cerebral Palsy (CP)
Diabetes
Autism
Orthopedic degenerative disorders

Success rates of stemcell treatment in India

There is about a 60% to 80% overall success rate in the use of stem cell therapy in both India and around the world. However, success rates vary depending on the disease being treated, the institute conducting the procedures, and the condition of the patient.

In order to receive complete information you will have to contact the medical institutes and ask specific questions concerning the patient's condition.

Thursday, October 1, 2009

This is a scanning electron microscope image f...

Image via Wikipedia

Each adult human consist of about 10¹³ (10,000,000,000,000) cells. These cells live in a gigantic "commune".
The human body contains about 200 different types of cells. Each cell has a very specialized role. Some examples:
- Unicellular blood cells:
  1. Some "tissues" in humans are populations of single cells that circulate throughout the body via the circulatory system. Examples:
    Erythrocytes: red blood cells transport oxygen and carbon dioxide [Image link: light micrograph].
    Phagocytic white blood cells: "eat" foreign materials, infectious agents, debris [Movie link: 509K 'mov.' file, from Cells Alive! Web site. Used with permission.]
- Multicellular tissue cells:
  1. Look at any human organ, such as the liver [Image link: light micrograph]. Then look at higher magnification -- it is made of individual liver cells [Image link: light micrograph]. View an electron micrograph of one liver cell [Image link: electron micrograph]. These are often used in textbooks as examples of "typical" cells, because they lack specialized structures that make other cells so distinctively recognizable. Actually, liver cells are biochemical specialists, converting thousands of chemicals into other chemicals so that your body can either digest or excrete them. Think "detoxification center" and you'll have a good image of a liver cell.
    Liver cells can be damaged by excess alcohol. Look at the liver cells [Image link: light micrograph] in this image -- can you spot any changes from the healthy cells seen above?
Each cell type has a characteristic lifetime, after which it commits suicide (apoptosis). Some examples:
- Neutrophils live about 1 day. [Image: light micrographs, including animation]
- Intestinal epithelial cells live about 3 days.
- Red blood cells live about 90 days
- Neurons live as long as 90 years
Each cell is totally responsible for it's own "housekeeping" duties:
- maintenance and repair
- acquiring food from blood or lymph
- disposal of wastes into blood or lymph
- synthesis and regulation of all its large biomolecules
- dividing (when allowed to do so) to create new cells by the process of mitosis, and not dividing unless properly signaled (cells that divide without responding to normal signals produce CANCER).
- carrying out its own specialized tasks, such as: contracting, making antibodies, firing nerve impulses, secreting digestive enzymes, etc.
  Examples: (1) nerve cells (communications specialists); (2) heart muscle cells (contraction specialists) [electron micrographs from Dennis Kunkel Microscopy. Used with permission].
Each cell must be able to communicate with other cells and respond appropriately to signals that regulate its activity.
Certain specialized cells must undergo a meiotic (sexual) cell division, produce eggs or sperm, and at least one such cell must find a partner if cellular life is to survive this particular individual.
Example: human egg and sperm cell [Scanning electron micrograph, from Dennis Kunkel Microscopy. Used with permission].
Each cell must differentiate from one common ancestral cell, the fertilized egg, by a complex process of differentiation and development. Example: Developing embryo, starting from single fertilized egg. [Movie: 3.1 meg 'mov.' file, from Univ. of Penn. Health System Web site]

What is Biology?

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"Biology" is not one science -- it is dozens of different sciences, each with its own set of tools and techniques, theories and questions, puzzles and paradigms. Here are some examples of biological sciences:

Biochemistry: biological molecules and their interactions; metabolism
Microbiology: bacteria, viruses, and other microscopic organisms, and their interactions with other organisms
Cytology and Histology: cell structures and their functions
Physiology: functions of tissues, organs and organ systems, such as the muscular system, the nervous system, etc.
Botany: plant diversity, structure, and functions
Zoology: animal diversity, structure, and functions
Genetics: the mechanisms of heredity, including its molecular machinery (DNA) and its observable consequences (e.g., genetic diseases).
Evolution: the mechanisms by which populations change over time
Ecology: the interactions of organisms with each other and their environments.

Botany

An agricultural scientist records corn (maize)...

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Civil Services Examination Strategy For Botany

Paper I

This paper in Botany is high-scoring provided your answers are simple, diagrammatic, and focuses on evolutionary aspects of questions.
Stay simple and give diagrams with Indian-centric views. This will help you to score good marks. You should summarize tables for last minute revision.

Microbiology in Section I is important for the 200-word short notes and you should practice accordingly. Applied aspects of queries are more important. In Plant Pathology you can safely leave description of diseases but should focus on physiological aspects.

In Cryptogams, the syllabus tells you to study plant group for their structure and reproduction with evolutionary viewpoint. The question in the examination however, does not mention the word evolution explicitly but examiners expect evolutionary treatment of questions.

Phanerogams is divided into various sub-groups. The key areas are:
Gymnosperms: Emphasis on fossil types
Angiosperms: Skip the families which were asked last year. Practice floral diagrams and formulas as much as possible
Anatomy: Not a consistent portion. It can be ignored if other portions are well prepared
Embryology: Stick to prescribed topics. Draw neat diagrams. The preparation of this portion can be clubbed with Morphogenesis.

Paper II

The strategy for this paper should revolve around providing updated information, colored illustrations and focus on applications.

In Cell Biology; focus should be on molecular aspect. Any long process should be discussed only with diagrams showing all the steps. Genetics, Molecular Biology and Evolution is a high scoring area in Paper II. The focus thus should be on making notes and writing crisp answers. Students should always highlight applications in agriculture and human welfare.

During the past three years, questions from Plant Breeding, Biotechnology and Biostatistics have been asked in compulsory section of the paper. The preparation strategy should revolve around making short notes and give stepwise crosses. They should also focus on "Role of Breeding in Crop Improvement in India".

In Physiology and Biochemistry; biochemical physiology is most important. In this year's examination, photosynthesis and nitrogen metabolism are more important than respiration. Students need to cover hormones and developmental physiology in areas like flowering, seed germination and fruit ripening.

In Ecology and Plant Geography; students can do with preparing just short notes. They can however afford to skip this section if they have covered other parts well.