The paper proposes moral and ethical guidelines for medical treatment at the edge of viability. The proposed principles are defended on the grounds of a general conceptual framework presented by elucidating the notions of viability, the edge of viability, person, sanctity of human life, dignity, and the slope of dignity protection, as well as the distinction between ethics and morality.
Heparanase that was cloned from and is abundant in the placenta is implicated in cell invasion, tumor metastasis, and angiogenesis. Recently we have demonstrated that heparanase may also affect the hemostatic system in a non-enzymatic manner. Heparanase was shown to up-regulate tissue factor (TF) expression and interact with tissue factor pathway inhibitor (TFPI) on the cell surface, leading to dissociation of TFPI from the cell membrane of endothelial and tumor cells, resulting in increased cell surface coagulation activity. More recently, we have shown that heparanase directly enhances TF activity, resulting in increased factor Xa production and activation of the coagulation system. Data indicate increased levels and possible involvement of heparanase in vascular complications in pregnancy. Taking into account the prometastatic and proangiogenic functions of heparanase, overexpression in human malignancies, and abundance in platelets and placenta, its involvement in the coagulation machinery is an intriguing novel arena for further research.
Advancements in computers, prototyping, and imaging, especially over the last 10 years, have permitted the adoption of three-dimensional imaging protocols in the health care field. In this article, the authors present an integrated simulation system for craniofacial surgical planning and treatment. Image fusion technology, which involves combining different imaging modalities, was utilized to create a realistic prototype and virtual image that can be manipulated in real time. The resultant data can then be shared over the Internet with distantly located practitioners.
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.
Heart failure is a leading cause of morbidity and mortality with a prevalence that is rising throughout the world. Currently the pharmaceutical therapy of heart failure is mainly based on inhibition of the neurohumoral pathways that are activated secondary to the deterioration of cardiac function, and diuretics to alleviate the salt and water overload. With our increasing understanding of the pathophysiology of heart failure, it is now clear that the macroscopic and functional changes in the failing heart result from remodeling at the cellular, interstitial, and molecular levels. Therefore, emerging therapies propose to intervene directly in the remodeling process at the cellular and the molecular levels. Here, several experimental strategies that aim to correct the abnormalities in receptor and post-receptor-function, calcium handling, excitation and contraction coupling, signaling, and changes in the extra-cellular matrix in the failing heart will be discussed. These novel approaches, aiming to reverse the remodeling process at multiple levels, may appear on the clinical arena in the coming years.
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 term sarcopenia describes the loss of skeletal muscle mass, strength, and function in old age. As the world population continues to grow older, more attention is given to the phenomena of sarcopenia and the search for strategies of prevention and treatment. The progression of sarcopenia is affected by age-related physiological and systemic changes in the body, including alterations in skeletal muscle tissue, hormonal changes, increased inflammatory activities, and oxidative stress. Sarcopenia progression is also affected by lifestyle factors which are far more controllable. These factors include various aspects of nutrition, physical activity, exercise, alcohol intake, and tobacco use. Raising the public awareness regarding the impact of these factors, as causes of sarcopenia and potential strategies of prevention and treatment, is of great importance. In this review we aim to describe various lifestyle factors that affect the etiology, prevention, and treatment of sarcopenia.
Life expectancy has been increasing in the last few decades in the Western world and is accompanied by higher occurrence of age-related diseases like metabolic, cardiovascular, and renal diseases and also with a decline in immune functions. In HIV-infected people, due to the use of combination antiretroviral therapy cART, life expectancy has increased. As a result, non-AIDS conditions which are age-associated have become more prevalent and appear earlier, resulting in accelerated aging in HIV patients. These non-AIDS conditions in HIV patients are associated with CD4+ T cell counts: lower counts are associated with higher rates of liver, cardiovascular, renal, and neurocognitive disorders. The effect of viral load and cART on the earlier occurrence of age-associated diseases is less significant than the CD4 count effect. Thus, the loss of immune functions in HIV-infected patients may enhance aging.
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.
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.
