The Adrenal

Caregiver bodywork: family members' experiences of caring for a person with motor neurone disease

AIM

This paper reports a study of how family members caring for people living with motor neurone disease managed the deteriorating body, their own bodywork and the associated emotional labour.

BACKGROUND

People living with the neurodegenerative condition of motor neurone disease face the prospect of dying in 3-5 years from progressive loss of voluntary muscle mass and function, culminating in respiratory failure. Theories concerning the body in illness have been used to illustrate patient perspectives; however, family caregivers' experiences of the body have been neglected.

METHOD

An ethnographic case study was undertaken with 18 primary family caregivers and six peripheral caregivers. Primary caregivers participated over 10 months in three face-to-face, semi-structured interviews which included mapping their support networks using ecomaps. Observational data were also recorded as field notes. Peripheral caregivers were interviewed once during the same time period. The data were generated between 2003 and 2004.

FINDINGS

Informal caregiving requires engagement in various aspects of bodywork. Three body concepts were identified: the visible body--how the disease affected the patient and caregivers; the dependent body--the resulting care requirements; and the social body--how living with motor neurone disease affected their social support networks. The visible body is a continual reminder of the ravages of the disease, while the dependent body demands physical and emotional care. Social interactions decline over time, depriving family caregivers of the much needed support for sustaining their commitment to the bodywork required in caregiving.

CONCLUSION

The demands of bodywork for family caregivers are increased by the continual presence of emotional labour as they seek to implement the best way to support their relative with motor neurone disease. Nurses and allied healthcare workers need to assess each family situation, asking appropriate questions to establish the most appropriate interventions to facilitate supportive care.

Unique neuronal functions of cathepsin L and cathepsin B in secretory vesicles: biosynthesis of peptides in neurotransmission and neurodegenerative disease

Proteases are required for the production of peptide neurotransmitters and toxic peptides in neurodegenerative diseases. Unique roles of the cysteine proteases cathepsin L and cathepsin B in secretory vesicles for the production of biologically active peptides have been demonstrated in recent studies. Secretory vesicle cathepsin L participates in the proteolytic conversion of proenkephalin into the active enkephalin, an opioid peptide neurotransmitter that mediates pain relief. Moreover, recent findings provide evidence that cathepsin B in regulated secretory vesicles participates in the production of toxic beta-amyloid peptides that are known to accumulate extracellularly in Alzheimer's disease brains. The neurobiological functions of cathepsins L and B demonstrate that these secretory vesicle cysteine proteases produce biologically active peptides. These results demonstrate newly identified roles for cathepsins L and B in neurosecretory vesicles in the production of biologically active peptides.

Advances in the delivery of treatments for Parkinson's disease

Innovative drug delivery in Parkinson's disease (PD) has the potential to reduce or avoid many side effects of current treatment, such as wearing-off type fluctuations, dyskinesia, on-off phenomena or bouts of motor freezing. The traditional orally administered formulations of l-dihydroxyphenylalanine combined with a peripheral aromatic acid decarboxylase inhibitor remain the mainstay of treatments for PD. However, such combination therapies have been further formulated to extend their duration of action by including a catechol-O-methyltransferase inhibitor. Preventing the breakdown of dopamine has also been achieved by monoamine oxidase-B inhibition; this approach now having been formulated for sublingual use (Zelapar, Valeant Pharmaceuticals). An alternative approach bypasses the oral route of administration and instead relies on continuous duodenal infusion (Duodopa, Solvay, NeoPharma AB) for better therapeutic effect. The clinical use of dopamine agonists as antiparkinsonian drugs now incorporates a variety of delivery techniques. For example, apomorphine, which relies on parenteral administration for maximum bioavailability, may be delivered via rectal, intranasal, sublingual and subcutaneous (e.g., Apokyn, Mylan Bertek) routes. Meanwhile, rotigotine and lisuride have both been formulated for delivery via skin patches. Finally, the authors examine more experimental delivery techniques, including the delivery of genes via viral vectors or liposomes, intracranial transplant of a variety of cells and of L-dihydroxyphenylalanine by prodrug-dispensing liposomes or pulmonary delivery (AIR, Alkermes). The advent and application of these varied technologies will help encourage patient-specific means of treatment for PD.

Protease pathways in peptide neurotransmission and neurodegenerative diseases

1. Recent research demonstrates the critical importance of neuroproteases for the production of peptide neurotransmitters, and for the production of toxic peptides in major neurodegenerative diseases that include Alzheimer's (AD) and Huntington's diseases. This review describes the strategies utilized to identify the appropriate proteases responsible for producing active peptides for neurotransmission, with application of such approaches for defining protease mechanisms in neurodegenerative diseases. 2. Integration of multidisciplinary approaches in neurobiology, biochemistry, chemistry, proteomics, molecular biology, and genetics has been utilized for neuroprotease studies. These investigations have identified secretory vesicle cathepsin L for the production of the enkephalin opioid peptide neurotransmitter and other neuropeptides. Furthermore, new results using these strategies have identified secretory vesicle cathepsin B for the production of beta-amyloid (Abeta) in the major regulated secretory pathway that provides activity-dependent secretion of Abeta peptides, which accumulate in AD. 3. CNS neuroproteases that participate in peptide neurotransmission and in neurodegenerative diseases represent new candidate drug targets that may be explored in future research for the development of novel therapeutic agents for neurological conditions.

Why is 11beta-hydroxysteroid dehydrogenase type 1 facing the endoplasmic reticulum lumen? Physiological relevance of the membrane topology of 11beta-HSD1

11Beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) is essential for the local activation of glucocorticoid receptors (GR). Unlike unliganded cytoplasmic GR, 11beta-HSD1 is an endoplasmic reticulum (ER)-membrane protein with lumenal orientation. Cortisone might gain direct access to 11beta-HSD1 by free diffusion across membranes, indirectly via intracellular binding proteins or, alternatively, by insertion into membranes. Membranous cortisol, formed by 11beta-HSD1 at the ER-lumenal side, might then activate cytoplasmic GR or bind to ER-lumenal secretory proteins. Compartmentalization of 11beta-HSD1 is important for its regulation by hexose-6-phosphate dehydrogenase (H6PDH), which regenerates cofactor NADPH in the ER lumen and stimulates oxoreductase activity. ER-lumenal orientation of 11beta-HSD1 is also essential for the metabolism of the alternative substrate 7-ketocholesterol (7KC), a major cholesterol oxidation product found in atherosclerotic plaques and taken up from processed cholesterol-rich food. An 11beta-HSD1 mutant adopting cytoplasmic orientation efficiently catalyzed the oxoreduction of cortisone but not 7KC, indicating access to cortisone from both sides of the ER-membrane but to 7KC only from the lumenal side. These aspects may be relevant for understanding the physiological role of 11beta-HSD1 and for developing therapeutic interventions to control glucocorticoid reactivation.

Who's there and who cares: age as an indicator of social support networks for caregivers among people living with motor neurone disease

This paper explores the social support networks available to the informal carers of people living with motor neurone disease (MND). An ethnographic case study was undertaken using eco mapping, observation and conversational interviews to collect data from 18 primary carers of people living with MND. Interviews took place in participants' homes in metropolitan, regional and rural locations. Participants discussed the content of their support network and drew lines between individuals to indicate the type and strength of relationship. Changes to the network were depicted on eco maps during subsequent interviews. While health policy-makers assume that healthy social capital exists in Australian communities and that social cohesion will ensure active and available support networks in times of illness or disability, data from this exploratory study indicated that this was not consistently the case. Support networks varied in size and composition; however, age was identified as a discriminator of the availability and consistency of support. People in older age groups identified more diverse but consistent support systems while people in younger age groups reported more fluctuations in the strength of relationships and declines in support as caregiving became more demanding. Individual assessment of support networks at regular intervals in the caregiving trajectory is vital for all carers. However carers in younger age groups may need specific support to manage the psychological crises that occur and more access to paid care. Older carers may need consistent support to handle more of the instrumental aspects of care and assistance to mobilise their support networks. Community workers should be alert to the possible need for crisis intervention when tensions in relationships threaten carers' ability to provide effective care.