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PubMed1997

The history of urology on postage stamps and cancellations.

PURPOSE: Many important phases and personalities in the history of urology have been depicted on postage stamps, stationery and cancellations. MATERIALS AND METHODS: The article gives a short recounting of several notable events that contributed to the development of urology as chronicled by philatelic material. RESULTS: Beginning with the Egyptian papyri and ending with a recently acknowledged urologist, the historical survey covers uroscopy, lithotomy, lithotrity, anatomy, pathology, instruments, surgical techniques in urology, imaging techniques of the urinary tract, dialysis and renal transplantation. Personalities whose accomplishments have made a deep imprint in the history of urology, if honored on philatelic items, are described in this article. CONCLUSIONS: Although the resulting picture does not necessarily present a continuity, it does emphasize certain peaks and high points in the evolution of this specialty.

History, 15th Century↗

PubMed1998

The units of selection.

Darwin's idea of evolution by natural selection is almost universally accepted by biologists, but debate continues about the units of selection. The history of this debate starts with Wynne-Edwards' arguments for group selection, and Hamilton's explantation of social behaviour in terms of the inclusive fitness of individuals. Hamilton's approach differs from the gene-centred approach pioneered by Williams and Dawkins, although both the problem and its solution are essentially the same. The choice of approach depends on conceptual and mathematical simplicity, and on one's attitude to the causal efficacy of genes. The problem of selection on units above the species level is discussed. Today, we are in the main concerned with cases in which selection acts simultaneously at two levels. This is true of current research on intragenomic conflict and of the suggestion by Maynard Smith and Szathmáry that in the major transitions in evolution, entities that were capable of independent replication before the transition can only replicate as part of a larger whole after it.

Animals↗

PubMed2001

Human ageing and the origins of religion.

During the evolution of hominids, the population could be sustained even with an expectation of life at birth of less than 20 years. Under these circumstances very few individuals reached old age. In these hunter-gatherer communities, altruistic behaviour was encouraged because it increased the likelihood of survival, whereas self-interest did not. An early moral code benefited the community as a whole. As social evolution progressed, the chances of survival increased, and for the first time very elderly individuals appeared. However, the reward for survival to old age was merely decrepitude and death. Under these circumstances, new incentives became a social necessity, and these took the form of a belief in an eternal afterlife. Religion then became the basis for the moral code, and it provided an assurance of continual survival after death.

Aging↗

PubMed1980

Carotenoid transformations underlying the blue absorbance change in flashed leaves during the induction of oxygen evolution.

The blue absorbance change occurring in flashed bean (Phaseolus vulgaris L.) leaves when exposed to continuous light (first observed by Strasser; Strasser, R.J. (1973) Arch. Int. Physiol. Biochem. 81, 935--955) is caused by the conversion of the following xanthophylls: violaxanthine leads to antheraxanthine leads to zeaxanthine. This conclusion is derived from the simultaneous occurrence of both reactions: (a) In flashed leaves, blue absorbance change and xanthophyll conversion take place under strong (2 mW . cm-2) but not under weak (0.02 mW . cm-2) white light. (b) In chloroplasts isolated from flashed leaves, the blue absorbance change occurs in the dark under conditions that also induce the xanthophyll conversion. (c) Blue absorbance change and xanthophyll conversion are both inhibited by dithiothreitol. In addition, the light-induced blue absorbance change is reversed in the dark if aerobic conditions are maintained, i.e. under conditions that in normal leaves favor the reversal of the above reaction sequence. The significance of the xanthophyll conversion is discussed in relation to other phenomena occurring in flashed leaves after exposure to continuous illumination.

Ascorbic Acid↗

PubMed1994

Ecosystem theory of evolution and social ethics.

Ecosystem evolution is driven by general laws for open systems aiming at immortality (first genetical then also cultural) of its components. Evolutionary impulses spread downward from ecosystem disturbances to population strategies to genome structures (opposite to the upward causation of traditional theory). Environmental cycles work as winding engine pushing evolution a step further at each round. Natural selection is being slackened with time while memory elaborates to conscious level. General trend is from unsustained growth to stability, individuation, increased diversity, standing biomass to productivity to dead mass ratios. Progressive evolution is interrupted by biospheric crises, or backward developments. Human activities contribute to the latter while for sustainable existence it will be necessary to switch from the crisis to the progress scheme. Human morals are grounded in million years of pre-human and pre-historic human evolution. However to be taught by nature means to comply with its progressive rather than backward tendencies. Human history as a continuation of the animal history is a perpetual struggle against natural selections.

Biological Evolution↗

PubMedDate not supplied

The evolution of surgery at the New York Hospital.

Surgery evolved from colonial times through many innovations and developments. During this time it was transformed from a dangerous practice to a delicate and scientific art. Many of these early developments continue to be a part of modern surgical therapy. Although European discoveries have had a profound effect on this evolution, American advances solidified the link between the laboratory and the operating room. The New York Hospital-Cornell Medical Center, like other medical centers around the country, made important contributions to this evolution. Because the hospital has spanned American history, it also has paralleled surgical development in the United States.

Education, Medical↗

PubMed2005

Pediatric sedation outside the operating room: the year in review.

PURPOSE OF REVIEW: This review is a survey of the recent literature concerning issues and trends in the rapidly changing field of pediatric sedation. RECENT FINDINGS: Clinical guidelines for the safe provision of sedation to children continue to be developed and revised. Systems for providing sedation are evolving, and the most successful models emerging are those that involve a dedicated team, either mobile or stationary, of physicians and nurses. A variety of drugs is used, and potent drugs that were designed as anesthetics, such as propofol and ketamine, are being administered outside the operating room by anesthesiologists and non-anesthesiologists. The safety of this practice continues to be debated. The reported incidence of adverse events is different in various settings and systems; however, outcome data are difficult to compare because of differences in study design and outcome definition. There is agreement that sedation is a continuum, and evidence that the depth of sedation attained during procedural sedation in children is often consistent with general anesthesia. Capnography and processed electroencephalogram monitoring have been described in sedation studies, may enhance safety during pediatric sedation, and should be investigated further. SUMMARY: The evolution of systems, drugs, and monitors for the provision of pediatric sedation is continuing. An accurate assessment of safety and other outcomes will be enhanced through the establishment of multicenter collaborative databases.

Journal Article↗

PubMed1987

Adaptation, plant evolution, and the fossil record.

The importance of adaptation in determining patterns of evolution has become an important focus of debate in evolutionary biology. As it pertains to paleobotany, the issue is whether or not adaptive evolution mediated by natural selection is sufficient to explain the stratigraphic distributions of taxa and character states observed in the plant fossil record. One means of addressing this question is the functional evaluation of stratigraphic series of plant organs set in the context of paleoenvironmental change and temporal patterns of floral composition within environments. For certain organ systems, quantitative estimates of biophysical performance can be made on the basis of structures preserved in the fossil record. Performance estimates for plants separated in time or space can be compared directly. Implicit in different hypotheses of the forces that shape the evolutionary record (e.g. adaptation, mass extinction, rapid environmental change, chance) are predictions about stratigraphic and paleoenvironmental trends in the efficacy of functional performance. Existing data suggest that following the evolution of a significant structural innovation, adaptation for improved functional performance can be a major determinant of evolutionary changes in plants; however, there are structural and development limits to functional improvement, and once these are reached, the structure in question may no longer figure strongly in selection until and unless a new innovation evolves. The Silurian-Devonian paleobotanical record is consistent with the hypothesis that the succession of lowland floodplain dominants preserved in the fossil record of this interval was determined principally by the repeated evolution of new taxa that rose to ecological importance because of competitive advantages conferred by improved biophysical performance. This does not seem to be equally true for Carboniferous-Jurassic dominants of swamp and lowland floodplain environments. In these cases, environmental disruption appears to have been a major factor in shaping the fossil record. This does not mean that continuing adaptation was not important during this interval, but it may indicate that adaptive evolution was strongest in environments other than those best represented in the paleobotanical record.

Adaptation, Biological↗

PubMed2001

Evolution and current use of the tuberculin test.

Since it was first introduced in the late 1800s, the tuberculin test has undergone continual refinement in its formulation, standardization, and dosage, as well as its interpretation and indications for use. New guidelines have replaced universal screening with targeted testing and rigid definitions of positivity with individualized criteria formulated from a Bayesian approach. This review summarizes the evolution of the test and provides information to help gauge its predictive value.

Animals↗

PubMed1999

Evolution of microcirculatory disturbances after permanent middle cerebral artery occlusion in rats.

Nonischemic brain capillaries show a continuous and heterogeneous plasma perfusion. In the current study, plasma perfusion was investigated in rats during 2 to 168 hours of permanent middle cerebral artery occlusion. Perfused capillaries were detected in brain cryosections by fluorescein isothiocyanate (FITC) dextran after 10 minutes of circulation time. Heterogeneity of capillary perfusion was identified by Evans blue (EB), which circulated for 3 seconds. In this setting, the heterogeneity of intracapillary EB concentrations reflects heterogeneities in capillary flow velocities. The CBF was quantified by simultaneous iodo[14C]antipyrine autoradiography. When moving from normal flow to low-flow areas in the ischemic hemisphere, three states of capillary filling could be distinguished: state 1--fast perfusion, filling by FITC dextran and EB (CBF 0.33 mL x g(-1) x min(-1)); state 2--delayed perfusion, only FITC dextran filling (CBF 0.104 mL x g(-1) x min(-1)); state 3--minimal perfusion, no dye filling (CBF 0.056 mL x g(-1) x min(-1)). In tissue of state 1 at the borderline to ischemic tissue, a higher heterogeneity of intracapillary EB concentration (85.7%) was found than in the contralateral nonischemic hemisphere (76.4%) (P < 0.05), indicating a compromised microcirculation. The adjacent ischemic areas were filled by FITC dextran (state 2) 2 to 4 hours after middle cerebral artery occlusion, indicating a maintained, although slow, perfusion at this time. Later, minimal perfused areas (state 3) progressively replaced the delayed perfused areas (state 2). This study shows, for the first time, the evolution of microvascular disturbances in relation to CBF. In the low-flow areas, an early residual plasma perfusion is later followed by a lack of perfusion or minimal perfusion. In areas of higher, although reduced flow at the border between normal and ischemic tissue, an extreme capillary perfusion heterogeneity indicates permanent microcirculatory abnormalities.

Animals↗

PubMed1994

Superinfection, metapopulation dynamics, and the evolution of diversity.

Using both analytic and numerical methods, we elucidate the dynamical properties of a class of metapopulation models in which many different species/strains contend for persistence, with local extinction of subpopulations being balanced by colonization of other patches. The species/strains have a strict competitive hierarchy with a given species/strain "taking over" any patch occupied by a lower-ranking species/strain; competitively inferior species/strains compensate by having higher colonization rates and/or lower patch death rates. New species/strains keep appearing, so that we can follow the evolution of the system. Such models may be metaphors for multispecies metapopulations, or for the evolution of virulence (where the patches are hosts, who are infected with various strains of a pathogen, and then die or recover at strain-dependent rates). Our emphasis is on a set of questions relating to the evolution of diversity. How many species/strains are present after a long time, t? Asymptotically, this number continues to increase very slowly, as ln t. What are the relative abundances of the species/strains? Under a broad range of assumptions about the mutations which produce new species/strains, the rank-abundance distribution is roughly geometric (as is commonly observed in early succession and other "ecologically one-dimensional" situations); some of our analysis here is based in part on an interesting but unproved mathematical conjecture about a new kind of probabilistic/combinatorial problem. If the number of patches/hosts is permanently reduced--by habitat destruction or vaccination--what happens? Characteristically, there is an initial sharp loss of species/strains (with selective removal of the competitive dominants), with subsequent slow recovery as new mutants continue to partition the now-diminished "niche space" (but the pristine levels of virulence are not regained).

Animals↗

PubMed1988

Stabilization procedures for thoracic and lumbar fractures.

New concepts regarding the biomechanics of spinal instability, new technology for spinal and neurodiagnostic imaging, further evolution of the role of neurological decompression, and the development of improved systems and techniques for achieving anatomical reconstruction and fixation of the spine continue to improve the care of patients suffering injuries of the thoracic and lumbar spine. This field of medicine is in rapid evolution, and newer improved methods will be forthcoming in the near future. An understanding of all of these developments as well as their limitations and potential complications is requisite if we are to optimize the functional capability of patients suffering these catastrophic injuries.

Bone Wires↗

PubMed2005

Positive and negative selection on mammalian Y chromosomes.

Y chromosomes are genetically degenerate in most organisms studied. The loss of genes from Y chromosomes is thought to be due to the inefficiency of purifying selection in nonrecombining regions, which leads to the accumulation of deleterious mutations via the processes of hitchhiking, background selection, and Muller's ratchet. As the severity of these processes depends on the number of functional genes linked together on the nonrecombining Y, it is not clear whether these processes are still at work on the old, gene-poor mammalian Y chromosomes. If purifying selection is indeed less efficient in the Y-linked, compared to the X-linked genes, deleterious nonsynonymous substitutions are expected to accumulate faster on the Y chromosome. However, positive selection on Y-linked genes could also increase the rate of amino acid-changing substitutions. Thus, the previous reports of an elevated nonsynonymous substitution rate in Y-linked genes are still open to interpretation. Here, we report evidence for positive selection in two out of three studied mammalian Y-linked genes, suggesting that adaptive Darwinian evolution may be common on mammalian Y chromosomes. Taking positive selection into account, we demonstrate that purifying selection is less efficient in mammalian Y-linked genes compared to their X-linked homologues, suggesting that these genes continue to degenerate.

Animals↗

PubMed2006

Making glucose oxidase fit for biofuel cell applications by directed protein evolution.

Progress in miniature chip-design raises demands for implantable power sources in health care applications such as continuous glucose monitoring of diabetic patients. Pioneered by Adam Heller, miniaturized enzymatic biofuel cells (mBCs) convert blood sugars into electrical energy by employing for example glucose oxidase (GOx) on the anode and bilirubin oxidase on the cathode. To match application demands it is crucial to increase lifetime and power output of mBCs. The power output has been limited by the performance of GOx on the anode. We developed a glucose oxidase detection assay (GODA) as medium-throughput screening system for improving GOx properties by directed protein evolution. GODA is a reaction product detection assay based on coupled enzymatic reactions leading to NADPH formation which is recorded at 340 nm. The main advantage of the assay is that it detects the production of d-gluconolactone instead of the side-product hydrogen peroxide and enables to improve bioelectrochemical properties of GOx. For validating the screening system, a mutagenic library of GOx from Aspergillus niger (EC 1.1.3.4) was generated and screened for improved activity using Saccharomyces cerevisiae as host. Directed evolution resulted in a GOx mutant I115V with 1.4-1.5-fold improved activity for beta-d-glucose (Vmax from 7.94 to 10.81 micromol min(-1) mg(-1); Km approximately 19-21 mM) and oxygen consumption kinetics correlate well [Vmax (O2) from 5.94 to 8.34 micromol min(-1) mg(-1); Km (O2) from 700 to 474 microM]. The developed mutagenic protocol and GODA represent a proof-of-principle that GOx can be evolved by directed evolution in S. cerevisiae for putative use in biofuel cells.

Bioelectric Energy Sources↗

PubMed2004

Sexual function after rectal excision.

BACKGROUND: Rectal excision is associated with a risk of autonomic nerve damage and associated sexual dysfunction (SD). The evolution of our understanding of the anatomy and physiology of sexual function together with continual refinement of surgery for both benign and malignant disease has led to a decrease in the incidence of SD after rectal surgery. A knowledge of the degree of risk of postoperative SD is important both for the patient and as a benchmark for audit of individual colorectal practice. METHODS: The available literature on the anatomy, physiology and surgical aspects of this topic has been researched through the Medline database. The more recently available data are reviewed in the context of the historical evolution of surgery for benign and malignant rectal disease. RESULTS AND CONCLUSIONS: In the best hands, permanent impotence occurs in less than 2% of patients following restorative proctocolectomy and at a similarly low rate after proctocolectomy and ileostomy. Isolated ejaculatory dysfunction is also numerically a minor problem post operation for benign disease. Patient age is the most important predictor of SD after surgery for rectal cancer. The incidence of permanent impotence remains high (>40%) after abdomino-perineal excision of the rectum (APE) but the continued decline in the use of this operation in favour of low anterior resection (LAR), which carries about half the risk of impotence compared to sphincter ablating surgery, is likely to have resulted in a fall in the absolute number of patients rendered impotent as a result of rectal cancer surgery. Anatomical dissection of the pelvis with preservation of the named autonomic fibres results in a low and predictable rate of sexual morbidity. Surgeons could profitably spend more time with their patients discussing the possible effects of surgery on sexual function. Further research is required to determine the effects of adjuvant therapy for rectal cancer on sexual function.

Autonomic Nervous System Diseases↗

PubMed1994

Hormone replacement therapy and estrogen-dependent cancers.

Until a few years ago, every treated breast cancer was an absolute contraindication to hormonal replacement therapy (HRT). However, the very high five-year survival rate in stage I breast cancer observed today brings more and more apparently healthy early postmenopausal women who have been treated for breast cancer in the past and who are suffering from heavy vasomotor symptoms due to estrogen deficiency to gynecological consultation. Usually well informed, the same group of women starts to worry about an increased risk of postmenopausal osteoporosis and of cardiovascular diseases. What attitude should be adopted today? Our approach should be differentiated and respect the staging, the estrogen-receptor status, and the presence or absence of axillary lymph-node metastasis of every patient. In estrogen receptor-negative women, there is no contraindication to continuous combined HRT by a fixed estrogen-progestin combination. In estrogen receptor-positive and lymph-node-negative patients, treatment by a nonaromatizable progestin, such as medrogestone or medroxyprogesterone acetate (MPA), can be introduced to relieve the patient from her postmenopausal syndrome. After 2-3 years of a favorable evolution of the treated cancer, the substitution might be shifted to a fixed-combined continuous HRT. Because estrogen receptor-positive and lymph-node-positive patients today are usually receiving adjuvant treatment with tamoxifen, they profit already from prophylaxis for postmenopausal osteoporosis and, very likely, from decreased cardiovascular risk. If women out of this group continue to suffer from heavy vasomotor symptoms, MPA might be added. However, it must be stressed that every administration of sexual steroids to women who have been treated for breast cancer has to be started only in full agreement with the treating oncologist concerned with the case and only after having obtained the informed consent of the patient. The new ethical dilemma will be our attitude to quality of life in relation to life prolongation.

Breast Neoplasms↗

PubMed2003

The critical role played by animal source foods in human (Homo) evolution.

Wild primates take most of the daily diet from plant sources, eating moderate to small amounts of animal source foods (ASF). Plant materials make up from 87% to >99% of the annual diet of great apes, the closest living relatives of modern humans (Homo sapiens sapiens). Reflecting their close genetic relationship, gut form and nutrient requirements of apes and humans (Hominoidea) are very similar, as is their pattern of digestive kinetics-one predicated on a relatively slow turnover of ingesta. In plant-eating mammals, in contrast to carnivorous mammals, greater body size is associated with lower dietary quality. Turning to ASF as a routine rather than occasional dietary component would have permitted the evolving human lineage to evade the nutritional constraints placed on body size increases in apes. Without routine access to ASF, it is highly unlikely that evolving humans could have achieved their unusually large and complex brain while simultaneously continuing their evolutionary trajectory as large, active and highly social primates. As human evolution progressed, young children in particular, with their rapidly expanding large brain and high metabolic and nutritional demands relative to adults would have benefited from volumetrically concentrated, high quality foods such as meat. Today, many humans, particularly those in high income nations, have a variety of high quality, non-ASF dietary alternatives, but such foods were not generally available to paleolithic human ancestors nor to many people today in low income nations.

Animals↗

PubMed1975

[Histochemical and histoenzymatic study of experimental myocardial infarction in the rat by temporary and permanent ligation of the left coronary artery (author's transl)].

The evolution of experimental myocardial infarction in the Rat with or without revascularization has been studied histochemically and histoenzymatically in 56 animals sacrified after 1, 6, 12, 24, 48 hrs and 7 days. Following permanent ischemis (14 animals), there appeared an extended transversal infarction marked by the complete disappearance of all phosphorylase activity (P-ase) after the first hour. During the first 6 hrs, changes appeared in succinodeshydrogenase (SHD) and cytochrome oxydase (Cyt-Ox). Glucose-6-phosphodeshydrogenase (G6PDH) presisted until lysis of the necrotic focus. It was possible to define a perinecrotic marginal area in which Pase activity is absent and SDH is granular "G3 in nature, characterized by continuous remodeling in the first 48 hrs. Following temporary ischemia (42 animals) the evolution was marked by rapid tissue reactions and early regression of the marginal zones. After 48 hrs and 7 days of survival, the planimetric evaluation of the infarcted area shows a definite reduction in the size of the infarctus in 50% of cases following removal of the ligature after 6 hrs, and in 66% of cases following removal of the ligature after 1 hr. It would appear probable that the revitalization of certain myocardial areas may extend from the marginal zones as is suggested by the reappearance in these zones several hrs after revascularization of P-ase and SDH activity. On the other hand, it is also true that the early restoration of blood flow does not always prevent the occurrence of an extended infarction. Certain recent observations have shown microcirculatory changes which are secondary to anoxia and should be studied further.

Animals↗