Blood:

The life saving donation

By Carol Aloysius

Voluntary blood donations have become increasingly important today, living as we are in a world where road accidents have soared to new heights with victims requiring immediate transfusion support with compatible blood that matches their blood group and pregnant women whose very lives depend on whether or not they get the badly needed blood transfusion during a specially complicated delivery. With the aim of commemorating the humanitarian act of voluntary blood donors and promoting the awareness on blood safety the WHO has declared June 14th as the World Blood Donor Day, which is celebrated world over every year.

Blood donations have also assumed special significance in the light of a surge in infectious diseases that could have serious impacts on the recipient if the donor happened to be infected by an infectious disease, such as HIV / AIDS or Hepatitis. To face this looming challenge the Health Ministry is currently introducing new technologies to further improve and strengthen the blood transfusion services in the country.

For its contribution in this field, the National Blood Transfusion Services (NBTS) Sri Lanka recently won global recognition and was awarded the Best Developing Country Award in 2012 .

In an interview with the Sunday Observer, Head of Quality Management/NBTS, Dr Kumudu Kuruppu discusses strategies put in place for ensuring safe blood and explains why this year's World Blood Donor day campaign focuses on the theme of ' Saving mothers with Safe blood'.

Excerpts ...

Q. Your organisation - the National Blood Transfusion Service (NBTS) was recently selected as the winner of the Developing County Award by the International Society of Blood Transfusion (ISBT). Tell us something of how your organisation functions.

A. National Blood Transfusion Service (NBTS) Sri Lanka is a state organisation which comes under the Ministry of Health and is dedicated to provision of blood and blood products and related laboratory, clinical, academic and research services for the country, extended to both state and private health sectors. Director NBTS is the executive head of the NBTS which functions with a centrally coordinated system comprising the National Blood Centre (NBC) and a network of 90 Hospital Based Blood Banks (HBBs) operationally categorised into 16 Clusters. NBC coordinates the key activities of formulating NBTS standards and guidelines, staff education and training, provision of resources for HBBs, statistical monitoring of HBB performance, introducing new technologies etc. to ensure safe and adequate supply of blood and blood products for the requirement of the country.

Q. Your organisation was recently selected as the winner of the Developing County Award by the International Society of Blood Transfusion (ISBT). Your comments?

A. NBTS Sri Lanka was awarded the Best Developing Country Award in 2012 at the 32nd International Congress of the ISBT in Cancún, Mexico.

This was awarded in recognition of its contribution in improving blood transfusion services within the country as well as its role in strengthening of regional and global collaboration in the field of blood transfusion.

NBTS has also won a number of National awards in the recent past which include Akimoto 5S award, National Quality Award, National Health Excellence Award, National Green award as well as the ISO 15189 Accreditation for its laboratory services.

Q. What are your main services to the public?

A. Main services provided by the NBTS are as follows:

Maintenance of an adequate and safe blood supply for the requirements of all needy patients through collection of blood from voluntary non-remunerated blood donors, Testing of all donated blood, for blood grouping to determine the ABO and RhD type of the donated blood, Testing of all donated blood for Transfusion Transmissible Infections (TTIs), Preparation of various blood components as required for clinical transfusion needs of the patients, Blood grouping and Blood Group Serology testing of patients, Storage and issue of blood products for clinical use, Provision of special laboratory services such as, red cell Immunohaematology testing and Histo compatibility testing, Provision of clinical advisory services and therapeutic services such as Therapeutic Plasma Exchange (TPE) and Cytapheresis.

Q. Is donated blood hundred percent tested?

A. In Sri Lanka 100 percent of the donated blood are mandatorily tested for HIV1 and 2, Hepatitis B, Hepatitis C, Syphilis and Malaria.

Q. Can anyone donate blood? Or are there any special eligibility criteria for blood donation?

A. NBTS has laid down selection criteria for blood donations based on WHO recommendations and other international standards.

For healthy individuals basic requirements for blood donation are;

• Age between 18 - 60 years.

• Weight;50 kg.

• Haemoglobin;12 g/d.Additional requirements will be addressed during donor counselling sessions.

Q. Your comments on self sufficiency of blood supply in Sri Lanka?

A. One of the main recommendations of WHO is achieving self sufficiency of blood and blood products based on voluntary non-remunerated blood donations (VNRBD) to ensure availability and accessibility of safe blood for the needy patients.

Presently with an annual blood collection of more than 350 000, it can be said we are self sufficient in our Red Cell requirements.

However due to five day short shelf life of platelets, and the need for ensuring ABO and RhD compatibility, fulfilling the demand for platelets would be a continuous challenge for NBTS, as for any other transfusion service.

Q. Do you see any fluctuations in the demand for blood? Is the blood donated now sufficient to meet the demand in the country?

A. During the war period there had been acute episodes of high demand for blood. NBTS managed to fulfil this demand effectively by increasing blood collection throughout the country and through effective mobilisation of existing blood stocks from the blood banks of unaffected areas. As a contingency plan, NBTS increased the duration of mobile campaigns and also facilitated and promoted in-house blood donations in HBBs.

In the recent past, there were episodes of high demand for platelets during dengue epidemics which were met successfully through increasing the number of platelet apheresis donations. However after the revision of dengue management protocols with minimum blood product usage, fluctuations in the demand of blood and blood products were not experienced recently.

Q. Do you foresee an increase in blood demand in the country?

A. Increase in the demand for blood and blood products is anticipated with developments of the new technologies and expansion of facilities in the health care system in Sri Lanka. With the improvements in organ transplantation facilities (eg: liver, heart - lung transplantation etc.), open heart surgeries and other related fields in the state and private health sectors, NBTS has to foresee an increase in demand for blood and blood products.

Q. Will our fast ageing population pose a problem in blood donations in future?

A. In most developed countries with ageing populations, the upper age limit for a regular blood donor is 70 years. It is unlikely a shortage of blood supply will occur due to special medical demand of ageing population as our collection program is well established with preparedness plans to meet changing trends of demand.

History

Q. Briefly tell us about the history of blood transfusion services in Sri Lanka.

A. The history of blood banking in Sri Lanka goes back to the 1950s. During that period it was confined to a small room in the present National Hospital of Sri Lanka. In those days, blood was collected into glass bottles and transfused as whole blood. Later after 1960s, with the introduction of PVC blood collection bag systems blood component preparation was started. During the initial period blood donors were given a payment for their donations. However since 1970s paid blood donations have been prohibited in Sri Lanka. During that period majority of the donations were collected from relatives of the hospitalised patients (Replacement Donors). From that era it has come a long way to the present status in which almost 100 percent donation are collected from Voluntary Non Remunerated Blood Donors (VNRBD).

Q. With HIV/AIDS now showing a slight increase compared to previous years, can a person with this disease pass it on to another through a blood transfusion? What precautions do you take to prevent the transmission of HIV and other diseases through blood transfusions?

A. HIV/AIDS can be transmitted through transfusion of blood and blood products. However though there may be an increase in HIV/AIDS infected population in Sri Lanka, this is comparatively low in the blood donor population.

This could be due to our practice of stringent donor selection through proper counselling making Sri Lanka one of the few countries with low prevalence of HIV in the donor population.

However, with a large migration populations and expansion in tourism there is a potentially increasing risk in HIV/AIDS infection rates in the general population.

Combating HIV/AIDS, malaria and other communicable disease is one of the millennium developments goals (MDGs) set by the UN. Recognising the role of a blood transfusion service in achieving this goal NBTS has strengthened the blood donation testing with the introduction of NAT (Nucleic Acid Testing) technology. By this the serological window period of the TTIs will be reduced markedly, thus maximizing the safety of the blood and blood products.

Furthermore, NBTS is in the process of introducing another advanced technology called "Pathogen Inactivation" by which any infective organism present in certain blood products such as platelets and plasma can be inactivated to further reduce the risk of infection transmission.

Q. NBTS is collaborating with the Health Ministry to organise a special 'Blood Donor Week' this year in relation to the celebrations of World Blood Donor Day which falls on June 14, with a theme of 'Saving Mothers with Safe Blood'. Why giving emphasis on mothers particularly?

A. WHO has given priority to this theme with the objective of improving maternal care in the global setting because of the rising number of deaths caused by bleeding during pregnancy or at delivery worldwide.

How the genetic blueprints for limbs came from fish

The transition from water to land is one of the most fascinating enigmas of evolution. In particular, the evolution of limbs from ancestral fish fins remains a mystery. Both fish and land animals possess clusters of Hoxa and Hoxd genes, which are necessary for both fin and limb formation during embryonic development. Denis Duboule's team, at the UNIGE and the EPFL, Switzerland, compared the structure and behavior of these gene clusters in embryos from mice and zebra-fish.

The researchers discovered similar three-dimensional DNA organisation of the fish and mouse clusters, which indicates that the main mechanism used to pattern tetrapod limbs was already present in fish.

However, when inserted into transgenic mouse embryos, the fish Hox genes were only active in the mouse arm but not in the digits, showing that the fish DNA lacks essential genetic elements for digit formation.

The study, thus concludes that, although the digital part of the limbs evolved as a novelty in land animals, this happened by elaborating on an ancestral, pre-existing DNA infrastructure.

Our first four-legged land ancestor came out of the sea some 350 million years ago.

Watching a lungfish, our closest living fish relative, crawl on its four pointed fins gives us an idea of what the first evolutionary steps on land probably looked like.

However, the transitional path between fin structural elements in fish and limbs in tetrapods remains elusive.

In animals, the Hox genes, often referred to as 'architect genes', are responsible for organising the body structures during embryonic development. Both fish and mammals possess clusters of Hoxa and Hoxd genes, which are necessary for fin and limb formation.

The team of Denis Duboule, professor at the University of Geneva (UNIGE) and the Ecole polytechnique fédérale de Lausanne (EPFL), Switzerland, had recently shown that, during mammalian development, Hoxd genes depend on a 'bimodal' 3-dimensional DNA structure to direct the development of the characteristic subdivision of the limbs into arm and paw, a division which is absent from fish fins.

'To determine where the genetics behind this subdivision into 'hand' and 'arm' came from during evolution, we decided to closely compare the genetic processes at work in both fin and limb development', says Joost Woltering, researcher at the Department of Genetics and Evolution of the UNIGE Faculty of Science and lead author of the study.

Surprisingly, the researchers found a similar bimodal 3-dimensional chromatin architecture in the Hoxd gene region in zebra-fish embryos.

These findings indicate that the regulatory mechanism used to pattern tetrapod limbs probably predates the divergence between fish and tetrapods.

"In fact this finding was a great surprise as we expected that this 'bimodal' DNA conformation was exactly what would make all the difference in the genetics for making limbs or making fins" adds Joost Woltering.

Does this imply that digits are homologous to distal fin structures in fish? To answer this question, the geneticists inserted into mice embryos the genomic regions that regulate Hox gene expression in fish fins. 'As another surprise, regulatory regions from fish triggered Hox gene expression predominantly in the arm and not in the digits.

Altogether, this suggests that our digits evolved during the fin to limb transition by modernising an already existing regulatory mechanism', explains Denis Duboule.

'A good metaphor for what has probably happened would be the process of 'retrofitting', as is done in engineering to equip outdated machine frames with new technology.

Only, in this case, it was a primitive DNA architecture which evolved new 'technology' to make the fingers and toes', says Joost Woltering. The researchers conclude that, although fish possess the Hox regulatory toolkit to produce digits, this potential is not utilised as it is in tetrapods.

Therefore, they propose that fin radials, the bony elements of fins, are not homologous to tetrapod digits, although they rely in part on a shared regulatory strategy.

- medicalXpress

Older people don't lose cognitive power they just know too much, say scientists

Researchers claim that brains function like hard drives - the more information we put in them, the longer it takes to recall it

A new study of memory recall in older people suggests that our brains don't lose cognitive power with age they just recall information more slowly, like a computer filled to bursting with data.

"The human brain works slower in old age but only because we have stored more information over time," said Dr Michael Ramscar of Tübingen University in Germany and lead author of the study. "The brains of older people do not get weak. On the contrary, they simply know more."

Dr Ramscar's research focused on re-evaluating the standard measures for cognitive performances, methods that he and his team claim are flawed. Using computers, the researchers modelled memory recall from different stages in an adult's lifetime, finding that when the computers' memory bank was smaller their performance resembled a young adult. When the computer was asked to recall information from a larger data set the performance looked more like that of an older adult.

"Imagine someone who knows two people's birthdays and can recall them almost perfectly," said Dr Ramscar. "Would you really want to say that person has a better memory than a person who knows the birthdays of 2,000 people, but can 'only' match the right person to the right birthday nine times out of ten?"

Calibrating their computer models to work with linguistic datasets, Ramscar's team found that tests of memory recall do not take into account the difference in vocabulary sizes between older and younger people.

"Forget about forgetting," said fellow researcher Peter Hendrix, "if I wanted to get the computer to look like an older adult, I had to keep all the words it learned in memory and let them compete for attention."

Another test conducted by the team asked volunteers to remember pairs of un-related words such as 'necktie' and 'cracker', a task that young people perform better at than older individuals.

- The Independent