Demented patients and the quandaries of identity: setting the problem, advancing a proposal

Advance directives need full legal status in persons with dementia

Currently, in the United States, there is no legal obligation for medical professionals or civil courts to uphold patients' Advance Directives (ADs) regarding end-of-life care. The applicability and standing of ADs prepared by Alzheimer's patients is a persistent issue in bioethics. Those who argue against giving ADs full status take two main approaches: (1) appealing to beneficence on behalf of the Alzheimer's patient and (2) claiming that there is no longer any personal equivalence between the AD's creator and the subject of the AD. In this paper, I present profound arguments against both approaches. Firstly, I argue that the principle of beneficence cannot apply in the case of Alzheimer's patients, and, secondly, that the moral and legal authority of the AD need not depend on strict equivalence of personal identity. I conclude by arguing that valid ADs protect the dignity and autonomy of Alzheimer's patients and that, therefore, there are moral obligations to uphold ADs which should be reflected in public policy and legislation.

Impact of frailty, mild cognitive impairment and cognitive frailty on adverse health outcomes among community-dwelling older adults: A systematic review and meta-analysis

Aims

This study analyzes the impact of frailty, mild cognitive impairment, and cognitive frailty on adverse outcomes in community-dwelling older adults.

Methods

This systematic review and meta-analysis were conducted using the PRISMA guidelines and MOOSE statement. We developed a specific search strategy for each electronic database and searched PubMed, Web of Science, MEDLINE, and Embase from initial records to July 2021. The studies on adverse outcomes of frailty, pre-frailty, mild cognitive impairment, and mild cognitive impairment with pre-frailty and cognitive frailty were included. Two researchers independently extracted data based on a spreadsheet and assessed the risk of bias. The primary outcomes were mortality, dementia, disability, and hospitalization. The second outcome included quality of life and falls. All analysis was conducted by using Review Manager (RevMan) 5.3 software.

Results

A total of 22 cohort studies (71,544 older adults with mean age ranging from 65.1 to 93.6 years) were included with a low risk of bias and high methodological quality with a NOS score ≥7. Compared to robust elders, individuals identified as frailty were associated with a higher risk of mortality (RR = 2.11, 95% CI: 1.57–2.83) and disability (RR = 5.91, 95% CI: 2.37–14.74). Mild cognitive impairment with pre-frailty was associated with mortality (RR = 1.74, 95% CI: 1.48–2.05) and dementia (RR = 4.15, 95% CI: 1.87–9.20). Pre-frailty was associated with a higher risk of mortality (RR = 1.29, 95% CI: 1.11–1.50). Cognitive frailty was associated with higher risk of incident mortality (RR = 2.41, 95% CI: 1.97–2.94), dementia (RR = 3.67, 95% CI: 2.81–4.78), disability (RR = 11.32, 95% CI: 4.14–30.97), and hospitalization (RR = 2.30, 95% CI: 1.60–3.32), as well as poor quality of life.

Conclusion

Cognitive frailty could be a comprehensive psychosomatic predictor for adverse outcomes among older people. Interactions between frailty, mild cognitive impairment, and cognitive frailty on adverse outcomes must be further explored.

Systematic review registration

[https://inplasy.com/inplasy-2022-5-0064/], identifier [INPLASY202250064].

Synthesis, in vitro biological evaluation and molecular modelling of new 2-chloro-3-hydrazinopyrazine derivatives as potent acetylcholinesterase inhibitors‏ on PC12 cells

Background

The loss of cholinergic neurotransmission in Alzheimer's disease (AD) patients' brain is accompanied by a reduced concentration of Acetylcholine (ACh) within synaptic clefts. Thus, the use of acetylcholinesterase inhibitors (AChEIs) to block the cholinergic degradation of ACh is a promising approach for AD treatment. In the present study, a series of 2-chloro-3-hydrazinopyrazine derivatives (CHP1-5) were designed, synthesized, and biologically evaluated as potential multifunctional anti-AD agents.

Methods

In addition, the chemical structures and purity of the synthesized compounds were elucidated through using IR, ¹H and ¹³C NMR, and elemental analyses. Further, the intended compounds were assessed in vitro for their AChE inhibitory and neuroprotective effects. Furthermore, DPPH, FRAP and ABTS assays were utilized to determine their antioxidant activity. The statistical analysis was performed using one-way ANOVA.

Results

Based on the results, CHP4 and CHP5 exhibited strong AChE inhibitory effects with the IC₅₀ values of 3.76 and 4.2 µM compared to the donepezil (0.53 µM), respectively. The study examined the effect and molecular mechanism of CHP4 on the Ab1–42-induced cytotoxicity in differentiated PC12 cells. At concentrations of 0–100 μM, CHP4 was non-toxic in PC12. Additionally, Ab1–42 significantly stimulated tau hyperphosphorylation and induced differentiated PC12 cell death. Further, CHP4 resulted in diminishing the Ab1–42-induced toxicity in PC12 cell significantly. CHP4 at 30 μM concentration significantly increased the Ab1–42-induced HSP70 expression and decreased tau hyperphosphorylation.

Conclusions

According to the results of our studies CHP4 can be considered as safe and efficient AChEI and employed as a potential multifunctional anti-AD agent.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13065-022-00799-w.

Medawar and Hamilton on the selective forces in the evolution of ageing

Both Medawar and Hamilton contributed key ideas to the modern evolutionary theory of ageing. In particular, they both suggested that, in populations with overlapping generations, the force with which selection acts on traits declines with the age at which traits are expressed. This decline would eventually cause ageing to evolve. However, the biological literature diverges on the relationship between Medawar's analysis of the force of selection and Hamilton's. Some authors appear to believe that Hamilton perfected Medawar's insightful, yet ultimately erroneous analysis of this force, while others see Hamilton's analysis as a coherent development of, or the obvious complement to Medawar's. Here, the relationship between the two analyses is revisited. Two things are argued for. First, most of Medawar's alleged errors that Hamilton would had rectified seem not to be there. The origin of these perceived errors appears to be in a misinterpretation of Medawar's writings. Second, the mathematics of Medawar and that of Hamilton show a significant overlap. However, different meanings are attached to the same mathematical expression. Medawar put forth an expression for the selective force on age-specific fitness. Hamilton proposed a full spectrum of selective forces each operating on age-specific fitness components, i.e. mortality and fertility. One of Hamilton's expressions, possibly his most important, is of the same form as Medawar's expression. But Hamilton's selective forces on age-specific fitness components do not add up to yield Medawar's selective force on age-specific fitness. It is concluded that Hamilton's analysis should be considered neither as a correction to Medawar's analysis nor as its obvious complement.

Can aging research generate a theory of health?

While aging research and policy aim to promote 'health' at all ages, there remains no convincing explanation of what this 'health' is. In this paper, I investigate whether we can find, implicit within the sciences of aging, a way to know what health is and how to measure it, i.e. a theory of health. To answer this, I start from scientific descriptions of aging and its modulators and then try to develop some generalizations about 'health' implicit within this research. After discussing some of the core aspects of aging and the ways in which certain models describe spatial and temporal features specific to both aging and healthy phenotypes, I then extract, explicate, and evaluate one potential construct of health in these models. This suggests a theory of health based on the landscape of optimized phenotypic trajectories. I conclude by considering why it matters for more candidate theories to be proposed and evaluated by philosophers and scientists alike.

Between hoping to die and longing to live longer

Drawing on Ezekiel Emanuel's controversial piece 'Why I hope to die at 75,' I distinguish two types of concern in ethical debates about extending the human lifespan. The first focusses on the value of living longer from prudential and social perspectives. The second type of concern, which has received less attention, focusses on the value of aiming for longer life. This distinction, which is overlooked in the ethical literature on life extension, is significant because there are features of human psychology and the structure of a life that should give pause when considering how long one should aim to live, but which do not neatly coincide with considerations about how valuable additional life is likely to be. I argue that, while Emanuel's case for hoping to die at 75 is unconvincing, he nonetheless provides weak pro tanto considerations in favour of taking a moderate life span as a prudential aim around which to base at least some significant life plans.

Does anybody really know what time it is? : From biological age to biological time

During his celebrated 1922 debate with Bergson, Einstein famously proclaimed: "the time of the philosopher does not exist, there remains only a psychological time that differs from the physicist's." Einstein's dictum, I maintain, has been metabolized by the natural sciences, which typically presuppose, more or less explicitly, the existence of a single, univocal, temporal substratum, ultimately determined by physics. This reductionistic assumption pervades much biological and biomedical practice. The chronological age allotted to individuals is conceived as an objective quantity, allowing one to straightforwardly assign and compare the biological age of organisms. This essay argues that the standard practice of assessing the age and aging of organisms against the backdrop of a physical conception of time is problematic. This becomes especially evident in light of recent discoveries of various levels of senescence underlying the development of individual organisms-a phenomenon known as 'age mosaicism.' The bottom line is that the study of age and aging requires a biological conception of time, as opposed to a physical one. Einstein clearly wasn't wrong about his operationalization of time in relativity theory. Still time may be less monolithic than he surmised.

The time of one's life: views of aging and age group justice

This paper argues that we can see our lives as a snapshot happening now or as a moving picture extending across time. These dual ways of seeing our lives inform how we conceive of the problem of age group justice. A snapshot view sees age group justice as an interpersonal problem between distinct age groups. A moving picture view sees age group justice as a first-person problem of prudential choice. This paper explores these different ways of thinking about age group justice and illustrates them using a principle of respect for human dignity, understood in terms of reasonable support for floor level central human capabilities at each stage of life. I argue that different frames are suitable for different kinds of decisions, and each provides a true, but partial, picture of aging and age group justice.