Reproduction and longevity among the British peerage: the effect of frailty and health selection.
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Whether a cost of reproduction exists among humans is still questionable. A major study of aristocratic British families finds a significant positive correlation between parity and late-life mortality, which indicates a trade-off between reproduction and longevity. This result is supported by four other studies, while earlier studies have not found a relationship or came to the opposite conclusion. We show that in natural fertility populations the relationship between fertility and late-life mortality cannot be studied correctly without considering the effects of differences in health and of mortality selection during childbearing ages because these two effects lead to a dampening of the true relationship. If these effects are controlled in Hollingsworth's genealogy of the British peerage a significant trade-off between reproduction and longevity exists for females but not for males. (+info)
The interchange of disease and health between the Old and New Worlds.
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A review of the five centuries since Columbus discovered America helps us understand the mutual contributions of the Old and the New Worlds to the history of diseases and their treatment. It also shows the consequences of this "mutual discovery" as they are currently emerging in the fields of health, culture, and the environment. To evaluate the multiple aspects of the interchange between the Old and New Worlds, this paper discusses the following: the causes of the rapid decline of the original American populations; the diffusion of communicable diseases between the two civilizations; the health consequences of nutritional changes on both sides of the Atlantic; drug addictions, as they developed through the centuries and as they exist today; the ways diseases were and are evaluated, prevented, diagnosed, and treated; and the mutual impact of different models of health services. Arguing that a major global change following the discovery of America was the transition from isolation of the two worlds to communication, and, more recently, to global interdependence, the paper also discusses some problems of bioethical relevance and the possible impact of new epidemics. Finally, it suggests that a critical analysis of the past may help stimulate future cooperation and solidarity. (+info)
ANTONY VAN LEEUWENHOEK.
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This is an essay about the Dutch linen-draper of the seventeenth century who made more than 500 microscopes and used them to observe the tail of an eel, the sting of a bee, the nose of a louse, the brain of a fly, the spinning apparatus of a spider, the bacteria from his own mouth, etc., and who wrote enthusiastic letters to the Royal Society of London carefully describing what he saw. (+info)
Resurrecting Van Leeuwenhoek's rotifers: a reappraisal of the role of disaccharides in anhydrobiosis.
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In 1702, Van Leeuwenhoek was the first to describe the phenomenon of anhydrobiosis in a species of bdelloid rotifer, Philodina roseola. It is the purpose of this review to examine what has been learned since then about the extreme desiccation tolerance in rotifers and how this compares with our understanding of anhydrobiosis in other organisms. Remarkably, much of what is known today about the requirements for successful anhydrobiosis, and the degree of biostability conferred by the dry state, was already determined in principle by the time of Spallanzani in the late 18th century. Most modern research on anhydrobiosis has emphasized the importance of the non-reducing disaccharides trehalose and sucrose, one or other sugar being present at high concentrations during desiccation of anhydrobiotic nematodes, brine shrimp cysts, bakers' yeast, resurrection plants and plant seeds. These sugars are proposed to act as water replacement molecules, and as thermodynamic and kinetic stabilizers of biomolecules and membranes. In apparent contradiction of the prevailing models, recent experiments from our laboratory show that bdelloid rotifers undergo anhydrobiosis without producing trehalose or any analogous molecule. This has prompted us to critically re-examine the association of disaccharides with anhydrobiosis in the literature. Surprisingly, current hypotheses are based almost entirely on in vitro data: there is very limited information which is more than simply correlative in the literature on living systems. In many species, disaccharide accumulation occurs at approximately the same time as desiccation tolerance is acquired. However, several studies indicate that these sugars are not sufficient for anhydrobiosis; furthermore, there is no conclusive evidence, through mutagenesis or functional knockout experiments, for example, that sugars are necessary for anhydrobiosis. Indeed, some plant seeds and micro-organisms, like the rotifer, exhibit excellent desiccation tolerance in the absence of high intracellular sugar concentrations. Accordingly, it seems appropriate to call for a re-evaluation of our understanding of anhydrobiosis and to embark on new experimental programmes to determine the key molecular mechanisms involved. (+info)
CT manifestations and features of solid cystic tumors of the pancreas.
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OBJECTIVE: To study retrospectively the manifestations and characteristics of solid cystic tumor of the pancreas(SCTP)on CT. METHODS: Nine patients with solid cystic tumor of the pancreas underwent resection with pathological and immunohistochemical confirmation. All the patients were female, aged 27.7 years on average at onset of the disease. CT scan was performed in patients with or without intravenous injection of contrast medium; it was also performed in the arterial phase in 4 patients. RESULTS: Solid and cystic structures were observed in tumors of the pancreas. Solid structure demonstrated low or iso-density on unenhanced CT, poor enhancement in the arterial phase and marked enhancement in the portal venous phase on contrast material-enhanced CT. Cystic structure showed low density on both pre- and pro-contrast views. The CT findings of tumors with predominantly cystic or equal proportion of solid and cystic structure: mural nodules for solid structure, "floating cloud" signs, or solid and cystic crossing distributions. Cystic structure of tumors predominately solid presenting as a beading appearance under capsule. In round, oval and completely encapsulated tumors in the pancreas, the greater vessel enhanced with well-defined margins on pro-contrast images. No dilatation was observed of the common bile and pancreatic ducts. CONCLUSION: The characteristics of solid cystic tumor of the pancreas revealed by CT could confirm the diagnosis of the disease in combination with onset age and sex of patients. (+info)
Gunther von Hagens and Body Worlds Part 1: the anatomist as prosektor and proplastiker.
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Recent calls to reintegrate the sciences and humanities are challenged by the contemporary work of anatomist Gunther von Hagens and his Body Worlds exhibits of plastinated cadavers. The anatomical quest to understand our physical interior has long been in tension both with aesthetic ideals and religious sensitivities regarding the metaphysical significance of the human body. Part I of this two-part Historical Note examines tensions epitomized by Goethe's figures of the prosektor and proplastiker. The former, driven by scientific curiosity, is willing to destroy, even desecrate, the human form to obtain knowledge. The latter demurs at such mutilation of our physical body, wondrous even in death--seeking instead to rejoin what the prosektor has pulled apart, to restore human dignity. In the confrontation between prosektor and proplastiker, roles disturbingly fused in the person of von Hagens himself, questions arise regarding the authenticity of models as well as the appropriate recipients of such mediated yet intimate anatomical knowledge. Part II will focus on religious perspectives on the human body, variously interpreted as God's handiwork, habitation for the soul, and vehicle of resurrection. Consideration also is given to the role of anatomist as priest, prophet, and Promethean creator, roles self-consciously embraced by von Hagens. (+info)
The worshipful Society of Apothecaries of London.
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The Society of Apothecaries is both a City livery company and an examining authority for the medical profession. Founded in 1617 by the royal apothecary Gideon de Laune leading a breakaway group from the Grocers' Company, the Society was instrumental in raising the status of apothecaries as general practitioners. Under the Apothecaries' Act (1815) the Society examined for the LSA and it now awards the LMSSA (Licence in Medicine and Surgery of the Society of Apothecaries) and postgraduate diplomas, while maintaining the civic, charitable, and ceremonial traditions of a livery company of the City of London. (+info)
Being there: the library as place.
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The value of the library as place is examined in this Janet Doe Lecture. The lecture, which is intended to focus on the history or philosophy of health sciences librarianship, presents an overview of the library as a place in society from ancient times to the present. The impact of information technology and changes in the methods of scholarly publication from print to digital are addressed as well as the role of the library as the repository of the written historical record of cultures. Functions and services of libraries are discussed in light of the physical library facility of the future. Finally, librarians are asked to remember the enduring values of librarianship in planning libraries of the future. (+info)