[Maurice Raynaud (1834-1881) and the Mystery of "Raynaud's Phanomenon"]. / Maurice Raynaud (1834­1881) und das Mysterium "Raynaud-Phänomen".

Maurice Raynaud first described color changes and symptoms of the fingers due to cold-induced vasospasm and restricted blood flow in his medical school thesis in 1862. Raynaud's phenomenon is common and exists as an uncomplicated primary Raynaud phenomenon and a Raynaud phenomenon secondary to underlying diseases and medication. Mechanisms contributing to altered vasoconstrictor activity are endothelial and not-endothelial. Cold-induced vasospasm is probably a thermoregulatory problem and effects are mediated by sympathetic activity and selective stimulation of alpha2c-adrenoreceptors.

[Maurice Raynaud (1834-1881) and the syndrome named after him]. / Maurice Raynaud (1834-1881) und das nach ihm benannte Syndrom.

Approximately 150 years ago Maurice Raynaud described in his doctoral thesis a set of symptoms characterized by intermittent pallor and cyanosis of the extremities which in severe cases could lead to the development of gangrene. Because the symptoms could be triggered by spasms in small blood vessels the exclusion of an organic vascular disease is a prerequisite of the diagnosis. Raynaud had not yet recognized that this often observed syndrome could sometimes be advance or initial symptoms of a severe general disease. This is the reason why nowadays these are referred to as primary and secondary Raynaud syndromes. Simultaneously to his doctoral thesis Raynaud had submitted his PhD thesis with two noteworthy publications on the history of medicine. His postdoctoral thesis encompassed a comprehensive study of the"efferent process". Raynaud worked in various Paris clinics, occupied himself with many problems and was considered to be a good academic teacher. For political reasons he was neither promoted to professor nor did he receive a chair in the history of medicine.

A restrospective perspective.

Venous occlusion plethysmography is a simple but elegant technique that has contributed to almost every major area of vascular biology in humans. The general principles of plethysmography were appreciated by the late 1800s, and the application of these principles to measure limb blood flow occurred in the early 1900s. Plethysmography has been instrumental in studying the role of the autonomic nervous system in regulating limb blood flow in humans and important in studying the vasodilator responses to exercise, reactive hyperemia, body heating, and mental stress. It has also been the technique of choice to study how human blood vessels respond to a variety of exogenously administered vasodilators and vasoconstrictors, especially those that act on various autonomic and adrenergic receptors. In recent years, plethysmography has been exploited to study the role of the vascular endothelium in health and disease. Venous occlusion plethysmography is likely to continue to play an important role as investigators seek to understand the physiological significance of newly identified vasoactive factors and how genetic polymorphisms affect the cardiovascular system in humans.

From Belfast to Mayo and beyond: the use and future of plethysmography to study blood flow in human limbs.

Venous occlusion plethysmography is a simple but elegant technique that has contributed to almost every major area of vascular biology in humans. The general principles of plethysmography were appreciated by the late 1800s, and the application of these principles to measure limb blood flow occurred in the early 1900s. Plethysmography has been instrumental in studying the role of the autonomic nervous system in regulating limb blood flow in humans and important in studying the vasodilator responses to exercise, reactive hyperemia, body heating, and mental stress. It has also been the technique of choice to study how human blood vessels respond to a variety of exogenously administered vasodilators and vasoconstrictors, especially those that act on various autonomic and adrenergic receptors. In recent years, plethysmography has been exploited to study the role of the vascular endothelium in health and disease. Venous occlusion plethysmography is likely to continue to play an important role as investigators seek to understand the physiological significance of newly identified vasoactive factors and how genetic polymorphisms affect the cardiovascular system in humans.

Effect of the air hammer on the hands of stonecutters. The limestone quarries of Bedford, Indiana, revisited.

In the limestone quarries of Indiana, USA, pneumatic percussive hammers replaced the mallet and hammer around 1900. By 1917 the air hammer was being used exclusively for periods of eight to ten hours a shift. In 1918 Alice Hamilton investigated an unusual "disease" in these stonecutters of Bedford, Indiana, who complained of "attacks of numbness and blanching of the fingers coming on suddenly under the influence of cold and then disappearing." The prevalence of vibration induced white finger (VWF) found in this population of 38 stonecutters was 89%, with decreased light touch, pain, and temperature appreciation in advanced cases. In 1978 a VWF research team revisited these limestone quarries. During the 60 year interval the stonecutting industry had contracted from 4000 workers in 40 quarries in 1918 to 3-400 in 10 quarries in 1978, with only 50 employees remaining in the Bedford area. In a population of 30 stonecutters the prevalence of VWF in 1978 was 80%, with similar sensory loss in light touch, pain, and temperature appreciation. Between 1918 and 1978 no change had taken place in the design of the air hammers used for stonecutting. Vibration levels of 4859 metres/s2 on the chisel, and 2010 metres/s2 on the barrel were measured over a frequency range 6.3 to 1000 Hz. The fundamental frequency was 75 Hz. These measured vibration levels are outside the ISO/DIS/5349 (1979) recommended limits for human exposure to vibration transmitted to the hand. The VWF data presented in this paper, and those originally reported by Hamilton in 1918, call for an immediate redesign of stonecutting pneumatic hammers in order to remove one cause of Raynaud's phenomenon of occupational origin.