It has been argued that human evolution has stopped because humans now adapt to their environment via cultural evolution and not biological evolution. However, all organisms adapt to their environment, and humans are no exception. Culture defines much of the human environment, so cultural evolution has actually led to adaptive evolution in humans. Examples are given to illustrate the rapid pace of adaptive evolution in response to cultural innovations. These adaptive responses have important impli-cations for infectious diseases, Mendelian genetic diseases, and systemic diseases in current human populations. Moreover, evolution proceeds by mechanisms other than natural selection. The recent growth in human population size has greatly increased the reservoir of mutational variants in the hu-man gene pool, thereby enhancing the potential for human evolution. The increase in human popula-tion size coupled with our increased capacity to move across the globe has induced a rapid and ongoing evolutionary shift in how genetic variation is distributed within and among local human populations. In particular, genetic differences between human populations are rapidly diminishing and individual het-erozygosity is increasing, with beneficial health effects. Finally, even when cultural evolution eliminates selection on a trait, the trait can still evolve due to natural selection on other traits. Our traits are not isolated, independent units, but rather are integrated into a functional whole, so selection on one trait can cause evolution to occur on another trait, sometimes with mildly maladaptive consequences.
Complex disorders are common in the human population and are caused by interplay between genetic and environmental factors. Therefore the quest for the genetic basis of such disorders has much similar-ity to deciphering the genetic basis of macro-evolutionary processes, such as speciation. Here I discuss conceptual connections between the principles underlying and processes occurring in disease and evo-lution. Special focus is given to the tremendous mitochondrial genetic variability in the population and within individuals and the impact of both types of variability on evolutionary processes and diseases.
The contributions of Jewish American surgeons in the nineteenth and early twentieth century at a time in which prejudice against ethnic and religious minorities was commonplace in the United States are detailed. The contributions of Jewish American surgeons and the positions they attained subsequent to a change in attitude toward religious minorities in the United States are presented as a comparison.
This paper describes the rapid evolution of modern liver surgery, starting in the middle of the twentieth century. Claude Couinaud studied and described the segmental anatomy of the liver, Thomas Starzl performed the first liver transplantations, and Henri Bismuth introduced the concept of anatomical resections. Hepatic surgery has developed significantly since those early days. To date, innovative techniques are applied, using cutting-edge technologies: Intraoperative ultrasound, techniques of vascular exclusion of the liver, new devices for performing homeostasis and dissection, laparoscopy for resections, and new drugs that allow the resection of previously unresectable tumors. The next stage in liver surgery will probably be the implementation of a multidisciplinary holistic approach to the liver-diseased patient that will ensure the best and most efficient treatments in the future.
I present a realistic view of what Darwinian evolution is in its current form and what it is not. I argue that the Torah is not a source of scientific knowledge and all attempts to reconcile its plain text with the data of science are an exercise in futility. The article argues the position that science and the Torah are incommensurable. I argue against using the Torah for attaining knowledge about the nature of the world, or using science for enhancing or denying the truth of the Torah.
After direct impact of the trauma, crush syndrome is the second most frequent cause of death after mass disasters. However, since crush syndrome is quite rare in daily practice, mistakes are frequent in the treatment of these cases. This paper summarizes the etiopathogenesis of traumatic rhabdomyolysis and of crush syndrome-based acute kidney injury. The clinical and laboratory features, prophylaxis, and treatment of crush cases are summarized as well. The importance of early and energetic fluid resuscitation is underlined for prophylaxis of acute kidney injury. Since there is chaos, and an overwhelming number of victims, logistic drawbacks create a specific problem in the treatment of crush victims after mass disasters. Potential solutions for logistic hurdles and disaster preparedness scenarios have also been provided in this review article.
Background—Bedside rounds have long been a time-honored component of medical education. Recently, there have been various recommendations that residency training programs further incorporate bedside teaching into clinical curricula.
Objectives—To compare these current attitudes regarding bedside education with the position of traditional Jewish law and ethics.
Methods—Relevant medical journal articles and traditional Jewish sources were reviewed.
Results—Halakha (the corpus of traditional Jewish law and ethics) gives greater focus to a patient-centered rather than student-centered bedside education experience.
Conclusion—Residency training programs should give greater consideration to the importance of a patient-centered bedside education experience.
Bone structural integrity and shape are maintained by removal of old matrix by osteoclasts and in-situ synthesis of new bone by osteoblasts. These cells comprise the basic multicellular unit (BMU). Bone mass maintenance is determined by the net anabolic activity of the BMU, when the matrix elaboration of the osteoblasts equals or exceeds the bone resorption by the osteoclasts. The normal function of the BMU causes a continuous remodeling process of the bone, with deposition of bony matrix (osteoid) along the vectors of the generated force by gravity and attached muscle activity. The osteoblasts are derived from mesenchymal stem cells (MSCs). Circulating hormones and locally produced cytokines and growth factors modulate the replication and differentiation of osteoclast and osteoblast progenitors. The appropriate number of the osteoblasts in the BMU is determined by the differentiation of the precursor bone-marrow stem cells into mature osteoblasts, their proliferation with subsequent maturation into metabolically active osteocytes, and osteoblast degradation by apoptosis. Thus, the two crucial points to target when planning to control the osteoblast population are the processes of cell proliferation and apoptosis, which are regulated by cellular hedgehog and Wnt pathways that involve humoral and mechanical stimulations. Osteoblasts regulate both bone matrix synthesis and mineralization directly by their own synthetic activities, and bone resorption indirectly by its paracrinic effects on osteoclasts. The overall synthetic and regulatory activities of osteoblasts govern bone tissue integrity and shape.
A very troubling issue for health care systems today is that of life-sustaining treatment for patients who have permanently lost their cognitive capacities. These include patients in persistent vegetative state (PVS), or minimally conscious state (MCS), as well as a growing population of patients at the very end stage of dementia. These patients are totally dependent on life-sustaining treatments and are, actually, kept alive “artificially.” This phenomenon raises doubts as to the ethics of sustaining the life of patients who have lost their consciousness and cognitive capacities, and whether there is a moral obligation to do so. The problem is that the main facts concerning the experiences and well-being of such patients and their wishes are unknown. Hence the framework of the four principles—beneficence, non-maleficence, autonomy, and justice—is not applicable in these cases; therefore we examined solidarity as another moral value to which we may resort in dealing with this dilemma.
This article shows that the source of the dilemma is the social attitudes towards loss of cognitive capacities, and the perception of this state as loss of personhood. Consequently, it is suggested that the principle of solidarity—which both sets an obligation to care for the worst-off, and can be used to identify obligations that appeal to an ethos of behavior—can serve as a guiding principle for resolving the dilemma. The value of solidarity can lead society to care for these patients and not deny them basic care and life-sustaining treatment when appropriate.
The randomized controlled trial is the fundamental study design to evaluate the effectiveness of medications and receive regulatory approval. Observational studies, on the other hand, are essential to address post-marketing drug safety issues but have also been used to uncover new indications or new benefits for already marketed drugs. For example, hormone replacement therapy (HRT), effective for menopausal symptoms, was reported in several observational studies during the 1980s and 1990s to also significantly reduce the incidence of coronary heart disease. This hypothesis was disproved in 2002 by the large-scale Women’s Health Initiative randomized trial. An example of a new indication for an old drug is that of metformin, an anti-diabetic medication, which is being hailed as a potential anti-cancer agent, primarily on the basis of several recent observational studies that reported impressive reductions in cancer incidence and mortality. These observational studies have also sparked the conduct of large-scale randomized controlled trials in cancer. We show in this paper that the spectacular effects on new indications or new outcomes reported in many observational studies in chronic obstructive pulmonary disease (COPD), HRT, and cancer are the result of time-related biases, such as immortal time bias, that tend to seriously exaggerate the benefits of a drug and that eventually disappear with the proper statistical analysis.
In all, while observational studies are central to assess the effects of drugs, their proper design and analysis are essential to avoid bias. The scientific evidence on the potential beneficial effects in new indications of existing drugs will need to be more carefully assessed before embarking on long and expensive unsubstantiated trials.
