The outgrowth of neurites from rat PC12 cells stimulated by combined treatment of nerve growth factor (NGF) with cAMP is significantly more rapid and extensive than the outgrowth induced by either factor alone. We have compared the responses of PC12 cells under three different growth conditions, NGF alone, cAMP alone, and combined treatment, with respect to surface morphology, rapidity of neurite outgrowth, and stability of neurite microtubules, to understand the synergistic action of NGF and cAMP on PC12. Surface events at early times in these growth conditions varied, suggesting divergent pathways of action of NGF and cAMP. This suggestion is strongly supported by the finding that cells exposed to saturating levels of dibutyryl cAMP without substantial neurite outgrowth initiated neurites within 5 min of NGF. This response has been adopted as a convenient assay for NGF. Neurites that regenerated in the three growth conditions showed marked differences in stability to treatments that depolymerize microtubules. The results indicate that microtubules in cells treated with both NGF and cAMP are significantly more stable than in either growth factor alone. We suggest that a shift of the assembly equilibrium favoring tubulin assembly is a necessary prerequisite for the initiation of neurites by PC12.The cytoskeleton is known to play a crucial role in the specification and maintenance of cell shape. The factors that organize the cytoskeleton and integrate the various filamentous components are poorly understood. The neuron is an unusually interesting system for the study of cytoskeleton function underlying cellular morphology. The exaggerated processes, axons and dendrites, of neurons are critically important for the function of the cells. The outgrowth of the axon is dependent upon the actin-based motility of the growth cone (24, 37, 38) and can be altered by a number of factors in the environment, including substrate adhesion (25) and nerve growth factor (NGF) ~ gradients (8). In addition, the advance of the growth cone requires the presence of the axonal microtubules (MTs) (1 l, 24, 37). The mechanism by which Abbreviations used in this paper, dbcAMP, N 6, O2-dibutyryl 3', 5'-cyclic adenosine monophosphate; MT, microtubule; N-cultures, containing NGF; NC-cultures, containing NGF and chloroadenosine or dbcAMP; NGF, nerve growth factor. growth cone motility is appropriately integrated with axonal MT assembly is unknown. Indeed, the spatial organization of axonal MTs is intriguing in other ways. In most cells, MT organization depends on a microtubule organizing center (27). Although axonal MTs are discontinuous (4, 36) and of uniform polarity orientation (7,20), no clear candidate exists for an axonal-microtubule organizing center.PC 12 cells are a clonal cell line derived from a rat pheochromocytoma of the adrenal medulla (14). PC12 can be induced to differentiate into cells with typical neuronal morphology by a number of substances, including NGF (14, 26) and cAMP (33, 34). Addition of both substances to P...

The second King’s College London Symposium on Ageing and Long-term Care in China was convened from 4 to 5th July 2019 at King’s College London in London. The aim of the Symposium was to have a better understanding of health and social challenges for aging and long-term care in China. This symposium draws research insights from a wide range of disciplines, including economics, public policy, demography, gerontology, public health and sociology. A total of 20 participants from eight countries, seek to identify the key issues and research priorities in the area of aging and long-term care in China. The results published here are a synthesis of the top four research areas that represent the perspectives from some of the leading researchers in the field.

The destigmatisation of dementia through awareness raising campaigns and associated activities has become a key pillar of dementia studies and related activism. This anti-stigma agenda is undermined by a poor evidence base and inadequate operationalisations of stigma. Scambler's distinction between felt stigma and enacted stigma provides a conceptual basis for improvement. Felt stigma encompasses negative self-appraisals and fears regarding the reactions of others, while enacted stigma describes active discriminatory behaviours. Awareness campaigns based around high-profile spokespeople and pathology-based models of dementia may effectively tackle enacted stigma, but they may also unintentionally exacerbate felt stigma. Distinguishing people with dementia as an exceptional group to elicit public sympathies promotes benevolent othering, unwittingly implying their negative otherness. This is problematic because felt stigma is typically more prevalent and deleterious to wellbeing than enacted stigma.

The Mental Capacity Act (MCA) has been in force in England and Wales for over a decade. Although often considered in relation to health and social care, the MCA also governs the inclusion of people with cognitive impairment in research. This includes procedures for establishing whether prospective participants are able to consent to participation. Despite its importance in research, there is little literature detailing accounts of researcher's experiences of working with the MCA's decision-making capacity procedures when conducting research. To address this deficit, we present our experiences when conducting three separate studies involving people with dementia and therefore falling within the MCA's research provisions. Study A (data collected between September 2016 and April 2017) discusses the subjectivity of capacity assessment; Study B (data collected between July and November 2017) details the negotiation of different opinions on capacity; and Study C (data collected between January and October 2013) considers tensions between legality and the principle of non-maleficence. Each of these experiences indicates a problematic degree of uncertainty within the MCA's decision-making capacity provisions. We suggest two solutions. First, more detailed guidance is required, responding to uncertainties emerging in practice. Second, researchers should be encouraged to publish their experiences of working with the MCA. In outlining our own experiences, we hope to initiate such a body of work.

In March 2020, the government of the United Kingdom advised all people aged 70 and above to self-isolate stringently for a minimum of 12 weeks in response to COVID-19. The British Society of Gerontology criticised the government for ignoring individual differences, deeming the approach ageist. Former British Geriatrics Society president David Oliver contested accusations of ageism, arguing that the approach was pragmatic discrimination based on epidemiological evidence. This debate catalyses core gerontological tensions regarding ageism, discrimination, categorisation and heterogeneity. A critical realist perspective reveals that both the government and gerontology are struggling to negotiate these irresolvable tensions. Contrary to the binary debate, age-based isolation simultaneously represents pragmatic discrimination and value-driven ageism. However, it does so partly because it relies on a chronologic epistemology that positions age as a potent biosocial axis of meaningful difference, thereby reflecting gerontology's own ageism. The ethical purism of gerontological accusations of ageism is thus somewhat misplaced, potentially obscuring an opportunity for reflection on value-laden engagements with age in social research.