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.
In Alzheimer’s disease (AD), premature demise of acetylcholine-producing neurons and the consequent decline of cholinergic transmission associate with the prominent cognitive impairments of affected individuals. However, the enzymatic activities of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) are altered rather late in the disease progress. This raised questions regarding the causal involvement of AChE and BChE in AD. Importantly, single nucleotide polymorphisms (SNPs), alternative splicing, and alternate promoter usage generate complex expression of combinatorial cholinesterase (ChE) variants, which called for testing the roles of specific variants in AD pathogenesis. We found accelerated amyloid fibril formation in engineered mice with enforced over-expression of the AChE-S splice variant which includes a helical C-terminus. In contrast, the AChE-R variant, which includes a naturally unfolded C-terminus, attenuated the oligomerization of amyloid fibrils and reduced amyloid plaque formation and toxicity. An extended N-terminus generated by an upstream promoter enhanced the damage caused by N-AChE-S, which in cell cultures induced caspases and GSK3 activation, tau hyperphosphorylation, and apoptosis. In the post-mortem AD brain, we found reduced levels of the neuroprotective AChE-R and increased levels of the neurotoxic N-AChE-S, suggesting bimodal contribution to AD progress. Finally, local unwinding of the α-helical C-terminal BChE peptide and loss of function of the pivotal tryptophan at its position 541 impair amyloid fibril attenuation by the common BChE-K variant carrying the A539T substitution, in vitro. Together, our results point to causal yet diverse involvement of the different ChEs in the early stages of AD pathogenesis. Harnessing the neuroprotective variants while reducing the levels of damaging ones may hence underlie the development of novel therapeutics.
KEY WORDS: Acetylcholinesterase, Alzheimer’s disease, apoptosis, beta-amyloid, butyrylcholinesterase
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.
Celiac disease (CD) is an autoimmune disorder occurring in genetically susceptible subjects. The incidence of CD is around 1%, and it is much more common in first-degree relatives of CD patients, 10%–18%. However, the pattern of the genetic inheritance is still obscure. Environmental factors are undoubtedly affecting the disease’s clinical presentation, time at presentation, and maybe effect on the characteristics of the disease. The clinical presentation of CD has shifted during the previous decades from the classical presentation in which the toddler suffers from diarrhea, constipation, vomiting, failure to thrive, abdominal distension, etc., to the child with a monosymptomatic presentation, such as anemia, as well as an enlarged list of extra-intestinal disorders. The diagnosis of CD is being established by symptoms consistent with CD and positive serology. The ultimate diagnosis should be made upon histological evaluation of the small bowel mucosa. The treatment of CD is a lifelong, strict gluten-free diet (GFD). Compliance with a GFD is quite difficult. Therefore, new strategies for prevention and treatment modalities other than GFD are greatly needed. Recently several promising therapeutic modalities have been developed; these include resuming traditional baking techniques. Another methodology is using probiotic-driven prolylendopeptidase. Another pathway to tackle the therapeutic option in CD is by down-regulation of the activity of zonulin—the active pump enabling gluten to enter the enterocytes. We are facing an era where other modalities beyond a GFD might allow CD patients to be able to tolerate occasionally a small amount of gluten in their diet.
The term sociotype has been introduced to describe the dynamic relationship of an individual with his/her social environment throughout life. The sociotype is a conceptual framework to highlight, in addition to bio-medical pathways, the psycho-social and environmental factors necessary to understand responses to life stresses and patient self-management for chronic illness. The sociotype interacts with genotype expression through mate selection and metabolic programming, and with the phenotype to determine adaptation throughout life from birth to old age. Following on the work of Antonovsky, Engel, and McEwen, and others in the life and social sciences, the sociotype details and expands the many factors generally included in the environmental influences on a person’s life identified here as the domains of health, relationships, and environment. Physiological mediators for sociotypic influences include: adrenal steroids and the sympathetic nervous system (allostatic load), and oxytocin (social neuroscience). The biological pathways are multiple through nutrition (essential dietary-derived amino- and fatty acids for neurotransmitter synthesis, caloric restriction, and diet–gene interactions), epigenesis, and metabolic programming. Nutrition influences growth and development, fertility and longevity, and also determines susceptibility to non-communicable diseases such as cardiovascular disease and cancer, and particularly diabetes and obesity, through in-utero effects, the development of intestinal flora (microbiome), and chronic stress. Thus the sociotype and nutrition are reciprocally related in both health and disease.
Late onset is a key unifying feature of human neurodegenerative maladies such as Alzheimer’s and Parkinson’s diseases and prion disorders. While sporadic cases typically emerge during the patient’s seventh decade of life or later, mutation-linked, familial cases manifest during the fifth or sixth decade. This common temporal emergence pattern raises the prospect that slowing aging may prevent the accumulation of toxic protein aggregates that lead to the development of these disorders, postpone the onset of these maladies, and alleviate their symptoms once emerged. Invertebrate-based studies indicated that reducing the activity of insulin/IGF signaling (IIS), a prominent aging regulatory pathway, protects from neurodegeneration-linked toxic protein aggregation. The validity of this approach has been tested and confirmed in mammals as reducing the activity of the IGF-1 signaling pathway protected Alzheimer’s model mice from the behavioral and biochemical impairments associated with the disease. Here I review the recent advances in the field, describe the known mechanistic links between toxic protein aggregation and the aging process, and delineate the future therapeutic potential of IIS reduction as a treatment for various neurodegenerative disorders.
The oldest-old are the fastest growing segment of the Western population. Over half of the oldest-old will have dementia, but the etiology is yet unknown. Age is the only risk factor consistently associated with dementia in the oldest-old. Many of the risk and protective factors for dementia in the young elderly, such as ApoE genotype, physical activity, and healthy lifestyle, are not relevant for the oldest-old. Neuropathology is abundant in the oldest-old brains, but specific pathologies of Alzheimer’s disease (AD) or vascular dementia are not necessarily correlated with cognition, as in younger persons. It has been suggested that accumulation of both AD-like and vascular pathologies, loss of synaptic proteins, and neuronal loss contribute to the cognitive decline observed in the oldest-old. Several characteristics of the oldest-old may confound the diagnosis of dementia in this age group. A gradual age-related cognitive decline, particularly in executive function and mental speed, is evident even in non-demented oldest-old. Hearing and vision losses, which are also prevalent in the oldest-old and found in some cases to precede/predict cognitive decline, may mechanically interfere in neuropsychological evaluations. Difficulties in carrying out every-day activities, observed in the majority of the oldest-old, may be the result of motor or physical dysfunction and of neurodegenerative processes. The oldest-old appear to be a select population, who escapes major illnesses or delays their onset and duration toward the end of life. Dementia in the oldest-old may be manifested when a substantial amount of pathology isaccumulated, or with a composition of a variety of pathologies. Investigating the clinical and pathological features of dementia in the oldest-old is of great importance in order to develop therapeutic strategies and to provide the most elderly of our population with good quality of life.
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.
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.
