Sunday, July 19, 2015

Acronym in biology: HHO for Havers-Halberg oscillation

Biological rhythms in animals have fascinated observers of nature for a long time. An example is the circadian rhythm, a diurnal rhythm synchronized with the day/night circle. In mammals, metabolic product rhythms with a twenty-four-hour oscillation pattern are known as the mammalian circadian clock [1]. The concentration of molecular components in body fluids rises and falls on a twenty-four hour cycle.

What about metabolites cycling according to a multidien schedule (multi-day schedule)?  Timothy G. Bromage of the Hard Tissue Research Unit of the New York University College of Dentistry describes findings of his research group showing that certain metabolites in the blood of domestic pigs cycled on a five-day rhythm. Those metabolites belong to two distinct groups: metabolites of one group reached their peak three days later than the other [2,3].

Until recently, such synchronized multi-day rhythms have commonly been overlooked in mammalian chronobiology studies. Most strikingly, the five-day rhythm leaves its marks in enamel and bone structures. The Bromage team found that the pig's teeth show the striae-of-Retzius pattern with a repeat period of exactly five. This evidence suggests a multidien rhythm that regulates growth and body size, which is called the Havers-Halberg oscillation (HHO) by Bromage and his colleagues [2]:

We call this rhythm the Havers-Halberg oscillation (HHO), after Clopton Havers who in 1691 described what we now know are lamellae in bone and striae of Retzius in enamel, and Franz Halberg, father of modern chronobiology. 

Periodic layer structures in hard tissue are documented for various mammal species. Rhythm & stria relationships, which will be similar to the reported correlation between biochemical oscillations and linear marks in pig teeth, can be expected to exist in other mammal species. For humans, the better understanding of such repeat patterns may eventually help to design individual health and healing plans in rhythm with metabolic cycles—think rhythmically tuned diet and medication.    

The English physician Clopton Havers was a pioneer in osteogeny. Anatomists are familiar with Haversian canals traversing compact bone tissue. Havers was born in 1657 in Stambourne, Essex. He is best known for his work on the microstructure of bone. In 1686, he was elected a Fellow of the Royal Society. Havers died in Essex in 1702 [3,4].

Franz Halberg was born in 1919 in Bistriz in Romania. In the 1940s, Halberg performed medicinal research at the University of Innsbruck and became a citizen of Austria. In 1948, he immigrated to the United States, where he continued his inqueries in biology and medicine.  Halberg  founded the fields of  quantitative chronobiolgy, chronomics and chronobioethics. He died in 2013 [5].

The term “Havers-Halberg oscillation” honors two outstanding scientists living in different epochs and gaining insight within until recently unconnected domains, which now find their synthesis in a more holistic view in the science community, deepening and advancing cross-subdiscipline understanding in life science.

Keywords: quantitative chronobiology, biological cycles, chronomics, osteogeny, stria of Retzius, life history.

References and more to explore
[1] Caroline H. Ko and Joseph S. Takahashi: Molecular components of the mammalian circadian clock. Human Molecular Genetics 2006, R271-R277 [].
[2] Timothy G. Bromage: Long in the Tooth: Striation in teeth reveal the pace of life. Natural History June 2015, 123 (5),16-21.
[3] Timothy G. Bromage and Malvin N. Janai: The Havers-Halberg oscillation regulates primate tissue and organ masses across the life-history continuum. Biological Journal of the Linnean Society August 2014, 112 (4), 649-656 [].
[4] Jessie Dobson: Clopton Havers [].
[5] The Blog of Funny Names: Clopton Havers, Bone Master [].
[6] Germaine Cornelissen, Francine Halberg, Julia Halberg and Othild Schwartzkopff: Obituary. Franz Halberg, MD (5 July 1919-9 June 2013) - In Appreciation. Chronobiology International 2013, 1-3 [].

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