Medicine

Medicine

Having destroyed the foetal pituitary, the pregnancy in that sheep just went on and on and on, and I can remember as those days passed, that sheep went past term and I got more and more excited. I finally interrupted it weeks past term by a Caesarian section.

Sir Graham (Mont) Liggins remembers his first experiments, which led to the discovery that foetal cortisol controls the timing of birth, broadcast in Eureka, National Radio, 3 February 2001

In 1926, Muriel Bell (1898-1974) became the first woman to be awarded a medical doctorate by the University of Otago. A farmer’s daughter from Murchison, Bell was one of New Zealand’s first female academics and soon established a reputation for her work in nutrition. Her thesis on the metabolism in goitre led to the introduction of iodised salt, and she was also responsible for the provision of free school milk. During the Second World War she campaigned for the use of fish oils as a source of vitamin D and came up with a recipe for rosehip syrup to supply vitamin C.

During the 1950s, after returning from a sabbatical at Harvard University, she fought for water fluoridation in New Zealand, a campaign that earned her the nickname ‘Battle-axe Bell’. Such was her reputation that she prepared the food rations for the men and dogs on Sir Edmund Hillary’s trans-Antarctic expedition in 1956/57.

Baby hearts

Most babies suffering from heart blood flow problems had little chance of survival until 1965, when Sir Brian Barratt-Boyes (1924-2006) devised a method of diverting the blood to its proper course through their hearts. Among his other advances was a method for cooling the body so the heart could be stopped to allow delicate surgery, and he was the first surgeon in New Zealand to replace diseased heart valves and to carry out pulmonary bypass operations.

Timing of birth

Another important medical discovery to come from New Zealand happened in an old shed on the grounds of Auckland’s National Women’s Hospital during the 1960s. It was about the timing of birth and about reducing the dangers of being born too early, and it made the name Sir Graham Liggins – Mont Liggins to his colleagues – famous in medical circles around the world.

Liggins followed his father into medicine and trained as an obstetrician/gynaecologist, delivering hundreds of babies between 1948 and 1989. However, he had another life – that of the scientist – squeezed into weekends and evenings.

One of the biggest killers of newborns is respiratory distress, the result of immature lungs. Liggins knew of a herd of cattle in California that had poorly developed pituitary glands and tended to experience prolonged pregnancies, so he started working on sheep, using his surgical skills to destroy the gland in lambs while they were still in the uterus. These experiments proved that the foetal pituitary controlled the timing of birth in sheep, but Liggins also worked out which hormone was responsible: cortisol.

A landmark study of mothers at imminent risk of early delivery, who were randomly assigned standard treatment or the same treatment plus two doses of steroids, showed a marked lowering of the incidence of respiratory distress in their premature babies. Confirmed by subsequent trials, the research changed medical practice and thus saved hundreds of thousands of lives.

Best start

The Liggins Institute in Auckland continues research into pregnancy, premature labour and foetal diet, under the leadership of Peter Gluckman, whose research focus is on the hormonal control of growth before and after birth and infant brain injury resulting from oxygen deprivation. Much of the research activity at the Liggins Institute is based around the concept that a person’s experience as a foetus affects his or her health throughout life. The groundbreaking theory that poor foetal development is a risk factor for some major diseases, including heart disease, stroke, diabetes and obesity, was in part proven by Liggins Institute scientists.

Meningococcal epidemic

New Zealand has one of the highest rates of meningococcal B disease in the developed world. Between 1991 and 2006 more than 5800 New Zealanders developed the disease, and 238 died. The epidemic could have continued for more than 20 years, but thanks to 13 years of extensive international collaboration and effort by principal ESR scientist Diana Martin, the actions of the Ministry of Health and committed medical personnel, a vaccine was developed, trialled and then delivered to New Zealanders under the age of 20. Martin identified the particular strain that was causing most of the cases in New Zealand, which helped Chiron Vaccines to manufacture and supply the vaccine, MeNZB. The nationwide immunisation programme began in the Counties- Manukau area in 2004. ESR tracks all cases of meningococcal disease and analyses the results from the vaccination programme and has reported a significant drop in cases caused by the epidemic strain since the introduction of the vaccine.

Nature via nurture

In 1972, families of 1037 newborns at Dunedin’s Queen Mary Maternity Hospital were asked to enrol their offspring in a longitudinal study that would follow their development right through to adulthood and beyond.

Since then most participants in the Dunedin Multidisciplinary Health and Development Study have long flown from their nest, but every few years they flock back to Dunedin for the next round of comprehensive health and lifestyle assessments.

When the cohort reached the age of 26, they were also asked to provide blood samples and swabs for DNA analysis – and it is this combination of genetic profiles and a rich database of health information that has allowed the researchers to investigate links between a person’s genetic make-up and environmental triggers.

The study’s director, Richie Poulton, says the research is beginning to makes sense of how genes and the environment interact to shape us.

By Veronika Meduna

Medals and awards

Muriel Bell: FRSNZ, CBE

Brian Barratt-Boyes: KBE

Mont Liggins: FRS

Peter Gluckman: FRS

Further reading and websites

Muriel Emma Bell biography – Dictionary of New Zealand Biography website

Liggins Institute website

Dunedin Multidisciplinary Health and Development Study website

Image courtesy Courtesy of the University of Otago

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