John Casey was born in Brisbane on 30 March 1934, the eldest of five boys. His earliest years were spent in North Queensland, with a year in evacuation in Herberton during the threat of invasion following Pearl Harbor. His family moved South in 1943, and John finished his primary schooling in Woodford, in the care of the Sisters of St Joseph, founded by St Mary MacKillop. Then came four years of secondary school at Downlands College in Toowoomba, with the Missionaries of the Sacred Heart. John won a State Open Scholarship to the University of Queensland in 1950, and started in Medicine. There was no family background in Medicine, but his father, a country publican, was friendly with the local doctor who exerted the most influence on John's choice of career.

John spent the six years of Medicine at St Leo's College then situated on Wickham Terrace. The medical faculty was scattered over many locations in the city and suburbs including William and George Streets, St Lucia and Herston.

In 1956, John passed MB BS with first class honours, and spent the next six years of hospital residency shared between the Brisbane General (now the Royal Brisbane and Womens) Hospital, and the newly completed Princess Alexandra Hospital. He passed the Membership examination for the Royal Australasian College of Physicians in 1961, and was granted the Fellowship in 1971.

An interest in Endocrinology was fostered by his association with Dr Alf Steinbeck, Reader in Medicine, and with Dr Martyn Lloyd. Correspondence with Dr (later Sir) John Nabarro at the Middlesex Hospital London led to an invitation to start training in Endocrinology there in 1963, incorporating a PhD in medical research supervised by Dr Alex Kellie in the Courtauld Laboratory of the Middlesex Hospital Medical School. The thesis was based on a newly developed assay of plasma testosterone by a double isotope dilution derivative technique, applied particularly to hyperandrogenism in women with hirsutism and polycystic ovarian disease. Sir John Nabarro had earlier fostered the careers of a succession of Australians, with Skip Martin, Henry Burger and Les Lazarus having preceded John at the Middlesex Hospital.

Recommended by Sir John Nabarro, John undertook training in clinical endocrinology at the McGill University Clinic of the Royal Victoria Hospital in Montreal from 1965 to 1967. Prominent endocrinologists there included John Beck, Martin Hoffman and Max McKenzie with busy clinics and wards. Laboratory work with steroids continued with Sam Solomon and with Beverley Murphy who had recently developed the technique of competitive protein binding for steroid hormone analysis, the forerunner of radioimmuno­ assay. Medical student teaching was part of his role at the Mc Gill University Clinic, similar to his duties at the Brisbane General four years earlier.

At the end of 1967, John was pleased to return to Australia to succeed Les Lazarus as staff endocrinologist at St Vincent's Hospital in Sydney, after Les had become Director of the Garvan Institute. They had a useful collaboration for several years, and John introduced the new assays for steroid hormones (particularly for cortisol, progesterone and testosterone) based on competitive protein binding. He also measured the metabolic clearance rate (and hence the production rate) of testosterone in a series of women with hyperandrogenism during various hormonal suppressive regimens, and demonstrated the benefit of combined ovarian/adrenocortical suppression. The response of cortisol and testosterone to exercise in fit and unfit subjects was also studied with John Sutton over several years.

Collaborative work at the Garvan Institute (with Warren Kidson, Ted Kraegen and Les Lazarus), established the low dose insulin infusion treatment for diabetic keto-acidosis This went on to become standard therapy worldwide for this condition.

The measurement of the mid cycle hormone profiles in practitioners of the Ovulation Method (Billings), showed for the first time that their days of perceived fertility closely correlated with the time of ovulation as determined by hormone analysis. This often quoted study contributed to the Scientific Basis of Natural Family Planning.

After ten years as staff endocrinologist, John began private consultant practice in 1977, the first in Sydney, while continuing as visiting medical officer at St Vincent's Hospital. This continued until he reached the retirement age of 65 in 1999, and highlights of those years included undergraduate and postgraduate teaching, and work in the Department of Medicine as Quality Improvement Coordinator. The Department of Endocrinology expanded with the appointments of Don Chisholm, John Eisman, Lesley Campbell and Ken Ho. Over the years there were many Research Fellows associated with the Garvan Institute: Cres Eastman, Warren Kidson, John Carter, David Chipps, Steven Judd, Margaret Zacharin and Peter Pullen.

John's other visiting medical officer appointments were at Lewisham Hospital, St Margaret's Hospital and the Royal Hospital for Women. For over 30 years, John had been consultant endocrinologist with the Australian Council of Natural Family Planning.

Since leaving the General Hospital in 1999, John's consultant practice had been confined to St Vincent's Clinic and St Vincent's Private Hospital, but he retired completely from both on his 75th birthday in March 2009.

John never had a family of his own, but kept a close attachment to his brothers and their children in Brisbane. Two nephews graduated in Pharmacy, before going on to graduate in Medicine and specialize in Haematology and in Anaesthetics. Others are involved in air conditioning, in the Navy, in psychotherapy, in nursing and in games technology. Two brothers have been priests of the Catholic Archdiocese of Brisbane, the younger still active in an inner city parish.

John retired to join his family in Brisbane in 2012, and settled into the Holy Spirit Retirement Village in Carseldine, where he was soon joined by two of his brothers. His interests are mainly related to music, and Wagner in particular. He has in past years made overseas trips devoted to art and architecture, with a Wagner Festival in Berlin in 2002, a tour 'In the Footsteps of Richard Wagner' in 2007, and possibly more to come. John has been able to index his extensive library, now also able to read those books purchased in the past and put aside until there was time to read!