HEART OF THE MATTER – Human/Pig..Monkey/Pig

A CHIMERA IS AN ORGANISM OR TISSUE WITH AT LEAST TWO SOURCES OF DNA. GENETIC MODIFICATION IS CREATING LABORATORY DESIGNED ANIMALS TO MEET HUMAN NEEDS

An international team of researchers has created embryos containing both human and monkey cells (July 2019) Spanish scientist Juan Carlos Izpisua Belmonte of the Salk Institute in San Diego  is spearheading the project with scientists from his own lab and those from the Murcia Catholic University in Murcia, Spain. The purpose of the experiment is to use chimeras to investigate ways of using animals to grow human organs for transplants. The research was conducted in China “to avoid legal issues”,

Monkey-Pig: New Scientist reported the birth of two chimera piglets in December 2019. Tang Hai State Key Laboratory of Stem Cell and Reproductive Biology in Beijing conducts research into the growth of human organs in animals for human transplantation. The piglets had been  injected with genetically modified monkey cells five days after embryo fertilization.  The piglets died but were found to have DNA from macaque monkeys in their heart, liver, spleen, lung and skin. The scientists aim to repeat the experiments ‘to create healthy animals with a higher concentration of monkey DNA, eventually reproducing a ‘pig’ with an organ containing only monkey DNA.’ The research paper, published in Protein and Cell, said the results brought the team “one step closer to producing tissue-specific functional cells and organs in a large animal model.”A Human-Pig hybrid embryo containing cells from humans and pigs was created in January 2017, at the Salk Institute in San Diego, but died 28 days later.

IN DEVELOPED COUNTRIES HEART DISEASE IS THE LEADING CAUSE OF DEATH WITH OVER 17 MILLION DEATHS WORLDWIDE- LIFE STYLE CHOICES ARE A MAJOR PART OF PREVENTATIVE CARE.

Zenotransplantation is the grafting or transplantation of organs or tissues between different species. Transplant surgery began some sixty years ago using ape and baboon hearts. In 1963, doctors at Tulane University attempted chimpanzee-to-human renal transplantations in six people, all died. The first heart transplant using a chimpanzee as a donor took place in 1964 at the University of Mississippi. An American child Stephanie Fae Beauclair was the first infant recipient when she received a baboon heart in 1984, she died a month later.  All the procedures were unsuccessful and due to public opposition, later research focussed on valve transplantation as an alternative. Pigs were then seen as a more acceptable donor than apes or monkeys, being already bred for consumption.

Valve transplantation started  in 1965, replacement of a heart valve can be accomplished using mechanical valves, or biological tissue, e.g. an autograft (from the patient’s own tissues), a homograft ( from a human cadaver), or a xenograft (from an animal).

Mechanical valves are made of strong, durable materials and are the most long-lasting type of replacement valve generally lasting throughout a patient’s life. Patients who receive a manufactured valve will almost always require a blood-thinning medication for the rest of their lives to avoid clots forming as a result of immune response to a foreign body.

Tissue valves (bioprosthetic)  are harvested from pig heart valves (porcine) or (bovine) from the sac surrounding the heart of a cow and can last 10 to 20 years. The introduction of the engineered Porcine (pig) Valve in 1972 revolutionised valve surgery. Specially bred donor pigs are genetically modified to minimise immune response allowing patients to avoid long-term use of medication. Calcification due to immune reaction does eventually cause tissue valve deterioration, valve replacement later in life is therefore highly likely for younger patients. Tissue valves have been gaining popularity over alternative mechanical valves, in 2011 82% of valve replacement surgery used tissue valves  according to the US Society of Thoracic Surgeons.

RESEARCHERS ARE NOW PREDICTING PIG-TO-HUMAN WHOLE ORGAN TRANSPLANTS OF HEART, KIDNEY AND LUNGS.

In 2015 the discovery that a pig virus could infect human cells in the laboratory was considered to pose an unacceptable risk and the FDA placed a hold on clinical trials involving cellular xenotransplant. The biggest area of concern to both doctors and patients is the possibility that xenotransplantation might create a new infectious disease epidemic, heightened by the current corona-19 pandemic, itself of zoonotic origin.  Retroviruses are found in the genetic material of mammals and cannot be ‘bred out’ of transplanted tissue, scientists view genetic modification as the answer. Dr Jeffrey Platt, an immunologist at Duke University Medical Centre in the US states: “We are walking a fine line between asking the immune system to accept an organ from an animal, but still protect us from other threats, such as infectious disease”.

  • A number of animal studies have suggested a link between the inflammatory response, clotting /coagulation and calcification which can occur in tissue valve transplant.(Vincentelli et al)  provided data suggesting  the transplanted tissue being the primary factor;  a further study supported this conclusion.) The layperson might be forgiven for feeling uneasy that ‘inflammatory response, clotting /coagulation and calcification’ are  reminiscent of the anti inflammatory symptoms now being identified in the most severe cases of the covid-19 viral pandemic.

Human organs have been grafted into animals for decades as a research technique for studying human biology – eg the mouse with an ear.

  • Hiromitsu Nakauchi plans to insert human stem cells into mice or rats in an attempt to grow a human pancreas in the animal. He states that as a safeguard, if too many human cells infiltrate the rat’s brains, the experiment will be stopped.
  • In July China announced research to create monkeys with partially human-derived brains in order to better study diseases like alzheimer’s.

FUTURE EXPERIMENTS IN THE FIELD MAY SAVE LIVES BUT CREATE A MORAL DILEMMA AND SURELY DEMAND THE INFORMED CONSENT OF THE PUBLIC  IF WE ARE TO AVOID A FURTHER DESCENT INTO THE AMORAL WORLD OF UNFETTERED SCIENCE.

At this unprecedented point in human history, humanity is being confronted with its shortcomings, an opportunity to consider ethical dimensions previous generations could not have envisaged. In its highest expression science is noble, humbly acknowledging humanity as one part of a vast cosmology. Those who elevate  humanity as the epitome of evolution may feel justified in using ‘lesser species’ to ensure their own survival, for  science without a soul sees the world as little more than a giant laboratory. The mythological figure of the lamassu , the bull/man has been selected  to represent the International Xenotransplantation Association and its official scientific journal, Xenotransplantation

As humanity hurtles towards destruction or spiritual renewal we are confronted from all angles with the opportunity to change direction. We each bear responsibility for the consequence of our choices and for what we allow in our name. Sadly the manipulation and decimation of numberless species will not ease our hearts or heal our souls.

See: A Step too Far?

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