I can understand Thai Airways International's refusal to return to Don Mueang. Their investment at Suvarnabhumi is heavy. On the other hand, I can understand that a split between domestic and international flights is highly impractical for travellers.
I also realise that many travellers would love to use Don Mueang again. I have used Suvarnabhumi once and all I can say is that it is hugely impractical in all respects. Parking is far away, walking distances in the building are enormous, architecture is cold and the long concrete corridor near the gates is claustrophobia-inducing. Reminds me of a bomb shelter.
As Suvarnabhumi is doomed to be a white elephant, it would be a smart move to return all passenger operations to an updated and improved Don Mueang and convert Suvarnabhumi to a cargo-only airport. This would be a very logical solution as the Eastern Seaboard is not only highly industrialised, but is also home to Thailand's largest deep-sea port not far away.
W STREULI
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The stem cell debate
I read with interest the article on "The stem cell debate" and, once again, the major ethical and moral issue in the stem cell debate is allowing people without basic scientific knowledge to write about stem cells.
From the article, it is intentionally unclear what type of stem cells we are talking about! Is it embryonic stem cells, fetal stem cells or adult stem cells from the person's own bone marrow, own umbilical cord blood, or own peripheral blood?
The first two categories of embryonic and fetal stem cells respectively raise ethical and moral concerns, and if the article is about those, then it should be clearly stated from the beginning. At all times when the public is addressed, the author must clearly define what kinds of stem cells are being debated to avoid confusion and conscious or unconscious misleading of the readers - unless the aim of the article is indeed to create confusion!
We develop from one single totipotent stem cell and our human body harbours adult stem cells since the first day of our lives and into long age. Those adult stem cells participate in the homeostasis of all our tissues and organs, aiding and promoting repair and regeneration. Initially and immediately at birth, blood from the umbilical cord can be collected and adult stem cells can be separated and cryo-preserved in the form of umbilical cord blood (UCB) stem cells. Those UCB stem cells are the source most readily available worldwide without pain or risk for the involved parties, most cost-effective and without ethical considerations.
Other stem cell sources available throughout life are the bone marrow (BM) and peripheral blood (PB) as a G-CSF stimulated extension of the former. Today, an estimated 45,000 to 50,000 hematopoietic stem cell transplants (blood or marrow transplants BMT), using predominantly autologous (patient's own) and related allogeneic (from within the patient's family) rather than unrelated allogeneic (unrelated donor), are performed annually worldwide to treat patients with life-threatening malignant and non-malignant diseases. Sixty per cent of all bone marrow transplants worldwide are autologous (patient's own stem cells) and similarly 80% of all allogeneic transplants come from within the greater family of the patient.
Cord blood stem cells have now surpassed the use of bone marrow and peripheral blood according to the April 2007 issue of the British Journal of Hematology. In Thailand, 80% of all transplants in children between 1997 and 2005 were either autologous or related allogeneic; that means either the patient's own stem cells or stem cells from within the family - the reason being tissue compatibility.
Our bone marrow is a magnificent factory regularly and constantly renewing the constituents of our blood system throughout life and increasingly appears to be a reservoir of immature cells that possibly take part in various regenerative and repair functions in our body.
Decreased levels of circulating endothelial progenitor cells (EPC)/CD34+ stem cells are now recognised as important indicators of cardiovascular disease and may have initiating roles in the pathogenesis of all diabetic complications and cardiovascular disease, and seem to convey cumulative cardiovascular risks better than Body Mass Index, diastolic blood pressure and total cholesterol.
Those observations inevitably and intuitively lead us to innovative therapeutic thoughts. Will modulation of EPC/CD34+ levels and function aid us to overcome the clinical needs and challenges in the 21st century created by changes in longevity and lifestyle, notably diabetes, cardio- and cerebrovascular disease, neurodegenerative diseases (Parkinson's and Alzheimer's) and joint ailments? In that case, is replacement with autologous ex vivo expanded/enriched EPC or pharmacological stimulation of the endogenous cells the best way to go?
The former would be possible if previous autologous storage at birth or at a young age before the development of the disease, was available to avoid the profound impairment of EPC in established diabetes and cardiovascular disease.
The latter could happen in two ways, one being physical exercise and administration of ACE inhibitors, statins and glitazones all known to stimulate EPC generation. Alternatively, classic G-CSF stimulation, autologous PBSC collection and consequent implantation around the areas needing regeneration and vasculogenesis could happen in both established disease or with previously stored autologous healthy and non-diseased PBSCs.
Future research on all the above-mentioned parameters will show us the way to proceed. Cord blood stem cells are now increasingly viewed as the capital ingredient for future cellular therapies in regenerative medicine, and may revolutionise the way we treat our society's major ailments and medical threats without causing any heated ethical debates.
The discussion should focus on early parental education regarding available alternatives and on the ethical dilemma created by the possibility of discarding cord blood stem cells rather than on whether or who should store it.
DR KOSTAS I PAPADOPOULOS
Specialist in Endocrinology and Diabetes
MD, PhD in Immunology and Endocrinology
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