Genetic determinants of sex in placental mammals developed by the evolution of primordial autosomes into the male and female sex chromosomes. The Y chromosome determines maleness by the action of the gene SRY, which encodes a protein that initiates a sequence of events prompting the embryonic gonads to develop into testes. The X chromosome in the absence of a Y chromosome results in a female by permitting the conversion of the embryonic gonads into ovaries. We trace the historical progress that resulted in the discovery that one X chromosome in the female is randomly inactivated in early embryogenesis, accomplishing approximate equivalency of X chromosome gene dosage in both sexes. This event results in half of the somatic cells in a tissue containing proteins encoded by the genes of the maternal X chromosome and half having proteins encoded by the genes of the paternal X chromosome, on average, accounting for the phenotype of a female heterozygote with an X chromosome mutation. The hypothesis of X chromosome inactivation as a random event early in embryogenesis was first described as a result of studies of variegated coat color in female mice. Similar results were found in women using the X chromosome-linked gene, glucose-6-phosphate dehydrogenase, studied in red cells. The random inactivation of the X chromosome-bearing genes for isoenzyme types A and B of glucose-6-phosphate dehydrogenase was used to establish the clonal origin of neoplasms in informative women with leiomyomas. Behind these discoveries are the stories of the men and women scientists whose research enlightened these aspects of X chromosome function and their implication for medicine.
This paper examines the morality of schemes of payment to live donors/sellers of organs for transplantation. Following empirical and historical evidence it is argued that consent to sell organs is substantially different from consent to ordinary business transactions and that legalization of exchanges of organs with financial benefits deviates significantly from the scope of liberal toleration and human rights. Although altruistic giving is commendable, it is immoral for society to benefit from them without conferring to the donors benefits such as health and nursing insurance for life. Non-alienable and non-fungible benefits of this kind are moral as incentives to organ donation/giving
The effects of genomic medicine on child health promise to be profound. Medical applications will eventually include characterizing patients’ genomes to detect predictive mutations for pre-symptomatic counseling where treatment exists; to search for causes of diseases of unknown etiology, and to detect carriers for prenatal counseling; to define cancer and other disease-based genomes to design individualized therapy; and to understand our microbiomes to modify these in health and disease. Rapid advances in technology and bioinformatics has reduced the cost and the time and increased the accuracy necessary to sequence whole genomes or whole exomes. However, complete understanding of disease will also require correlation of genomic information with high-quality phenotypic data. In addition, several critical ethical, psycho-social, and public policy issues will require clarity in the coming years. Ultimately these advances will improve the effectiveness of health care for children and for society.
Hereditary, environmental, and stochastic factors determine a child’s growth in his unique environ-ment, but their relative contribution to the phenotypic outcome and the extent of stochastic pro-gramming that is required to alter human phenotypes is not known because few data are available. This is an attempt to use evolutionary life-history theory in understanding child growth in a broad evolutionary perspective, using the data and theory of evolutionary predictive adaptive growth-related strategies. Transitions from one life-history phase to the next have inherent adaptive plasticity in their timing. Humans evolved to withstand energy crises by decreasing their body size, and evolutionary short-term adaptations to energy crises utilize a plasticity that modifies the timing of transition from infancy into childhood, culminating in short stature in times of energy crisis. Transition to juvenility is part of a strategy of conversion from a period of total dependence on the family and tribe for provision and security to self-supply, and a degree of adaptive plasticity is provided and determines body composition. Transition to adolescence entails plasticity in adapting to energy resources, other environmental cues, and the social needs of the maturing adolescent to determine life-span and the period of fecundity and fertility. Fundamental questions are raised by a life-history approach to the unique growth pattern of each child in his given genetic background and current environment.
Objective. To understand high-performing front-line employees’ values as reflected in their narratives of day-to-day interactions in a large health care organization.
Methods. A total of 150 employees representing various roles within the organization were interviewed and asked to share work-life narratives (WLNs) about value-affirming situations (i.e. situations in which they believed their actions to be fully aligned with their values) and value-challenging situations (i.e. when their actions or the actions of others were not consistent with their values), using methods based on appreciative inquiry.
Results. The analysis revealed 10 broad values. Most of the value-affirming WLNs were about the story-teller and team providing care for the patient/family. Half of the value-challenging WLNs were about the story-teller or a patient and barriers created by the organization, supervisor, or physician. Almost half of these focused on “treating others with dis/respect”. Only 15% of the value-challenging WLNs contained a resolution reached by the participants, often leaving them describing unresolved and frequently negative feelings.
Conclusions. Appreciative inquiry and thematic analysis methods were found to be an effective tool for understanding the important and sometimes competing role personal and institutional values play in day-to-day work. There is remarkable potential in using WLNs as a way to surface and reinforce shared values and, perhaps more importantly, respectfully to identify and discuss conflicting personal and professional values.
We review three decades of unsuccessful efforts by public policy-makers in the United States to develop programs to lower the rate of preterm birth. We analyze why these efforts had been unsuccessful. Finally, we will speculate about whether something has changed in the last few years that might finally bend the curve and reverse the trend of a steadily rising preterm birth rate.
The work presented in this review describes the use of large cortical networks developing ex-vivo, in a culture dish, to study principles underlying synchronization, adaptation, learning, and representation in neuronal assemblies. The motivation to study neuronal networks ex-vivo is outlined together with a short description of recent results in this field. Following a short description of the experimental system, a set of basic results will be presented that concern self-organization of activity, dynamical and functional properties of neurons, and networks in response to external stimulation. This short review ends with an outline of future questions and research directions.
Crohn's disease (CD) is a heterogeneous disorder that can involve any segment of the gastrointestinal tract.The pathogenesis of CD is unknown but is thought to involve an uncontrolled immune response triggered by an environmental factor in a genetically susceptible host.The heterogeneity of disease pathogenesis and clinical course, combined with the variable response to treatment and its associated side effects creates an environment of complex therapeutic decisions.
Despite this complexity, significant progress has been made which allows physicians to start and predict disease behavior and natural course, response to therapy and factors associated with significant side effects.
In this manuscript the data pertaining to these variables including clinical, endoscopic and the various biological and genetic markers are reviewed and the possibility of tailoring personal treatment is discussed.
The evolution of production systems is tightly linked to the story of Toyota Motor Company (TMC) that has its roots around 1918. The term “lean” was coined in 1990 following the exploration of the Toyota model that led to the “transference” thesis sustaining the concept that manufacturing problems and technologies are universal problems faced by management and that these concepts can be emulated in non-Japanese enterprises.
Lean is a multi-faceted concept and requires organizations to exert effort along several dimensions simultaneously; some consider a successful implementation either achieving major strategic components of lean, implementing practices to support operational aspects, or providing evidence that the improvements are sustainable in the long term.
The article explores challenges and opportunities faced by organizations that intend incorporating lean management principles and presents the specific context of the healthcare industry. Finally, the concepts of “essential few” and customer value are illustrated through a simple example of process change following lean principles, which was implemented in a dental school in the United States.
The Cox maze III and Cox maze IV procedures are surgical solutions for the treatment of symptomatic stand-alone atrial fibrillation. Despite their proven efficacy, these procedures have not gained widespread acceptance because of the invasiveness, complexity, and technical difficulty. Endocardial pulmonary vein isolation is the cornerstone of percutaneous catheter ablation for atrial fibrillation. It is currently accepted as an invasive therapy, if rhythm control has failed using antiarrhythmic drugs or electrical cardioversions. Pulmonary vein isolation is reported to be effective in 60%–85% of patients with paroxysmal atrial fibrillation and in 30%–50% of patients with persistent atrial fibrillation. A second or third ablation is often necessary to achieve these results, and complications may occur in up to 6% of patients.
Surgical treatment of atrial fibrillation has seen important improvements in the last decade. New technologies have simplified creation of transmural lesions on the beating heart through a less-invasive, thoracoscopic procedure. This allows for pulmonary vein isolation, isolation of the posterior wall, and left atrial appendage exclusion—usually combined with ganglionic plexi evaluation and destruction. Nonethe¬less, it is still uncertain whether these procedures are effective in restoring permanent sinus rhythm since transmurality of a lesion set cannot be guaranteed with current ablation catheters on the beating heart.
In an attempt to limit the shortcomings of an endo- or an epicardial technique, a hybrid approach has recently been introduced. This approach is based on a close collaboration between the surgeon and the electrophysiologist, employing a patient-tailored procedure which is adapted to the origin of the patient’s atrial fibrillation and takes into consideration triggers and substrate. Using a mono- or bilateral energy source, a thoracoscopic epicardial approach is combined with a percutaneous endocardial ablation in a single-step or in a sequential-step procedure.
This article provides our experience and an overview of the current knowledge in the hybrid treatment of stand-alone atrial fibrillation.
