Wilhelm Conrad Röntgen: The scientist and his discovery

Röntgen’s discovery of a new type of radiation is the epochal event in a series of highlights of physics emerging within only a few decades of the late 19th century. As these discoveries are directly or indirectly rooting in the study of the phenomenon of electric discharge in gases a brief look at the physics scenario in the immediate pre-X-ray era is presented in the first section. Rather than just the fortune with the bold it is Röntgen’s character as a diligent, self-critical and ingenious scientist which made his discovery possible. This will be illustrated in the sections on Röntgen’s personal life and some specific details of his experiments leading to the discovery of X-rays. Finally, a short overview is given on the potential and the large variety of applications of X-rays.     

D’une « nouvelle sorte de rayonnement » à la tomodensitométrie : une histoire du scanner

In this article, the authors present the evolution of radiology, from the discovery of X-rays until the invention of the CT scan. Since the invention of X-rays by W.C. Röntgen, the search for the third dimension in medical imaging has provided a lot of developments both in physics and in mathematics. This third dimension has finally occurred in the early 1970s when CT was put forward by G.N. Hounsfield. This paper places the developments in their historical context.     

The relative biological effectiveness of densely ionizing heavy-ion radiation for inducing ocular cataracts in wild type versus mice heterozygous for the ATM gene

The accelerated appearance of ocular cataracts at younger ages has been recorded in both astronauts and airline pilots, and is usually attributed to high-energy heavy ions in galactic cosmic ray radiation. We have previously shown that high-LET 1-GeV/nucleon ⁵⁶Fe ions are significantly more effective than X-rays in producing cataracts in mice. We have also shown that mice haploinsufficient for ATM develop cataracts earlier than wild-type animals, when exposed to either low-LET X-rays or high-LET ⁵⁶Fe ions. In this paper we derive quantitative estimates for the relative biological effectiveness (RBE) of high energy ⁵⁶Fe ions compared with X-rays, both for wild type and for mice haploinsufficient for ATM. There is a clear trend toward higher RBE’s in haploinsufficient animals, both for low- and high-grade cataracts. Haploinsufficiency for ATM results in an enhanced sensitivity to X-rays compared with the wild type, and this enhancement appears even larger after exposure to high-LET heavy ions.Dedicated to the memory of Professor Basil V. Worgul, who passed away in January 2006, much missed by all his colleagues.     

Biochemistry of the Infarcted Heart

I am honored by the invitation to contribute to a volume in Neuroscience, dedicated to Professor Galoyan, whose accomplishments in the field of neuroscience and circulation have been unique. In his book, Dr. Galoyan has summarized the results of his discovery of cardioactive neurohormones. His discovery of biosynthesis of cytokines in the neurosecretory cells of the hypothalamus have opened a new page in immunology.     

Focus: 50 Years of DNA Repair: The Yale Symposium Reports: The Awakening of DNA Repair at Yale

As a graduate student with Professor Richard Setlow at Yale in the late 1950s, I studied the effects of ultraviolet and visible light on the syntheses of DNA, RNA, and protein in bacteria. I reflect upon my research in the Yale Biophysics Department, my subsequent postdoctoral experiences, and the eventual analyses in the laboratories of Setlow, Paul Howard-Flanders, and myself that constituted the discovery of the ubiquitous pathway of DNA excision repair in the early 1960s. I then offer a brief perspective on a few more recent developments in the burgeoning DNA repair field and their relationships to human disease.     

Anecdote of the Ōmura laboratory and the discovery of avermectin†

I first met Professor ōmura, Distinguished Emeritus Professor, at The Kitasato Institute (Kitaken) when I was 28 years old. Since then, he has been my respectful supervisor as well as mentor. Looking back on those memories, I am deeply honored to write about the discovery and development of avermectin.     

Pursuing the unlimited potential of microorganisms—progress and prospect of a fermentation company†

Production of pharmaceuticals and chemicals using microbial functions has bestowed numerous benefits onto society. The Nobel Prize awarded to Professor ōmura, Distinguished Emeritus Professor of Kitasato University, showed the world the importance of the discovery and practical application of microorganisms. Now, increasing attention is turned toward the future path of this field. As people involved in the microorganism industry, we will review the industrial activities thus far and consider the possible future developments in this field and its potential contribution to society.     

The quest for industrial enzymes from microorganisms†

Satoshi ōmura, Professor Emeritus at Kitasato University, was awarded the Nobel Prize for his discovery of a substance of tremendous value to mankind from a microorganism. As a researcher who regularly deals with enzymes produced by microorganisms and a person engaged in microorganism-based business, Professor ōmura’s Nobel Prize fills me with great pride and joy. It is perhaps not surprising that this Nobel Prize-winning research would emerge from Asia, specifically Japan, where people live in harmony with nature rather than try to conquer it. At Amano Enzyme Inc., we devote ourselves to searching for novel enzymes from microorganisms. While incorporating my own experiences, I will recount the stories of a few discoveries of valuable enzyme-producing microbes in soil and bacterial strain libraries. I will also briefly introduce microbial strain library construction as a tool for facilitating the identification of the desired producing bacteria.     

Novel eicosanoid pathways

This article reviews a lecture I was honored to present at the Leon Wolfe Symposium in Montreal on March 25, 2004. The lecture described my research career, which started with my interaction with Wolfe at the Montreal Neurological Institute as a postdoctoral fellow and research associate and was followed by additional research discoveries after I left Montreal for my first academic position at the Research Institute, The Hospital for Sick Children and University of Toronto. The article consists of two parts. The first part involves the discovery (in Wolfe’s laboratory) of a new pathway of arachidonic acid, in which a bicyclic prostanoid structure (later called prostacyclin by John Vane and his group) was described, and its further development in Toronto, which led to the discovery of the conversion of the bicyclic prostanoid into 6-keto prostaglandin F_1α. The second part deals with the hepoxilin pathway, a pathway I discovered during a sabbatical leave in Japan with Professor Shozo Yamamoto, which was followed by a stay of several months in the laboratory of Professor Bengt Samuelsson in Sweden. I deal with the historical aspects of both pathways and end with interesting novel aspects of hepoxilin stable antagonist analogs in the treatment of solid tumors in experimental animals.     

Gene silencing by double-stranded RNA

Thanks to the Nobel Foundation for permission to publish this Lecture. We report here the Nobel Lecture delivered by Professor Andrew Z Fire. Together with the accompanying lecture by Professor Mello this lecture describes the exciting years leading to the discovery of RNA interference (RNAi) and some of the underlying molecular mechanisms. Professor Fire nicely points out his own contribution and the contribution of other research groups to the development of this field. He also presents an interesting discussion on the role of RNAi in immunity and challenges us with a number of open questions. The lecture ends presenting the great potential of exploiting RNAi for therapeutical purposes.     

Henry Dale and the discovery of acetylcholine

In 1936 Sir Henry Dale of London and Professor Otto Loewi from Graz shared the Nobel Prize in Physiology or Medicine for their work on chemical neurotransmission. This paper uses much unpublished archival material to augment an examination of Dale's work, from his discovery of naturally occurring acetylcholine in 1913, through to evidence of its role as a neurotransmitter at autonomic ganglia, post-ganglionic parasympathetic nerve terminals and the neuromuscular junction.     

From metabolism to comparative biochemistry of toxic organophosphorus compounds. To the 100th anniversary from the birth of V. I. Rozengart

The main stages of the scientific biography of Professor Victor losifovich Rozengart are exposed: his works on muscle bioenergetics, discovery of the pathway of creatinine synthesis, his development of novel concepts of pathways of metabolism of organophosphorus xenobiotics, creation of biochemical grounds of selective toxicity as well as studies in the new field whose one of its founders he is--comparative biochemistry of toxic organophosphorus compounds.     

Selman A. Waksman,Winner of the 1952 Nobel Prize for Physiology or Medicine

The history of the discovery and development of streptomycin is reviewed here from the personal standpoint of a member of Dr. Selman Waksman''s antibiotic screening research team. The team approach of eight individuals illustrates how the gradual enhancement of the screening methodology was developed. I illustrate three study periods with key aspects in the development of streptomycin which led to a Nobel Prize being granted to Professor Waksman. One item not previously emphasized is the employment of a submerged culture technique for large-scale production of streptomycin, thus enabling rapid animal testing and human clinical trials with Mycobacterium tuberculosis. Another is that purified streptomycin was shown by Dr. Waksman to be distinctly different from the substances called natural products, which are no longer patentable in the United States; therefore, streptomycin was found to be patentable. A third item not previously emphasized is his emphasis on the screening of actinomycetes, including the newly named Streptomyces genus. All of these factors contributed to the success of streptomycin in the treatment of tuberculosis. In combination, their successes led to Dr. Waksman''s department becoming a new pharmacological research area, specializing in drug discovery. These unique accomplishments all burnish the prior rationales used by the Karolinska Institute in granting Dr. Waksman alone the 1952 Nobel Prize for Physiology or Medicine.     

Fluorescence lifetime,yield, energy transfer and spectrum in photosynthesis, 1950–1960*

The fluorescence lifetime of chlorophyll agives information about the primary photo-physical events in photosynthesis. Most of the light energy absorbed by chlorophylls is utilized for photochemistry. There are two main additional pathways competing for the absorbed light energy: fluorescence and radiationless internal conversion (heat). Only a few percent of the absorbed energy proceeds along these two pathways. This historical minireview focuses on the first direct measurements of the lifetime of chlorophyll fluorescence, the time it takes to transfer energy from phycoerythrin to chlorophyll a, and the discovery of the fluorescence band at 720 nm (F720; then attributed to a dimer of chlorophyll). These works were carried out during the the late 1950s to the early 1960s in the laboratory of Professor Eugene Rabinowitch at the University of Illinois, Urbana-Champaign [Brody (1995) Photosynth Res 43: 67–74]. This Minireview is dedicated to Professor Eugene Rabinowitch (1901–1973), mentor of the author (Steve Brody) as well as of the editor, and authors classmate (Govindjee). The career and contributions of Eugene Rabinowitch are available in a dedication by Bannister (1972). This revised version was published online in June 2006 with corrections to the Cover Date.     

G2 phase cell cycle disturbance as a manifestation of genetic cell damage

The predominant cell cycle change induced by X-rays and clastogens in peripheral blood mononuclear cells is the accumulation of cells in the G2 phase of the cell cycle. We show that this accumulation consists of cells that are either delayed or arrested within the G2 phase. Since both X-rays and DNA crosslinking chemicals are known to damage DNA, the G2 phase inhibition caused by these agents is thought to be one of the primary manifestations of (unrepaired) DNA damage. This interpretation is supported by two additional findings. (1) Older individuals have elevated baseline levels of mononuclear blood cells that are delayed and/or arrested in the G2 phase of the cell cycle. This coincides with the increased chromosomal breakage rates reported for older individuals. (2) Irrespective of their age, individuals with inherited genetic instability syndromes (such as Fanconi anemia and Bloom syndrome) exhibit elevated G2 phase cell fractions. We show that the method used to detect such induced or spontaneous cell cycle changes, viz. BrdU-Hoechst flow cytometry, is a rapid and highly sensitive technique for the assessment of genetic cell damage.Dedicated to Professor Ulrich Wolf on the occasion of his 60th birthday