A qualitative study exploring why adults with intellectual disabilities and obesity want to lose weight and views of their carers.

BACKGROUND: Obesity is more prevalent in adults with intellectual disabilities (ID) compared to the general population. Motivations for weight loss may influence engagement with weight management programmes and have only been studied in adults without ID. AIMS: To determine reasons given by adults with ID and obesity for seeking weight loss and whether these reasons differ from those of their carers. METHODS: Prior to a multi-component weight management intervention, participants were asked "why do you want to lose weight?" Carers were asked their views and these were compared to the answers given by the adult with ID. Responses were themed. The Fisher's Exact analysis was used to test for any relationship between reasons for seeking weight loss and participants' level of ID, age, gender and BMI. RESULTS: Eighteen men and 32 women; age 41.6 SD 14.6 years; BMI 40.8 SD 7.5 kg/m(2); Level ID Mild (28 %), Moderate (42 %), Severe (22 %), Profound (8 %). Eleven were unable to respond. Six themes emerged; Health; Fitness / Activity / Mobility; Appearance / Clothes; Emotional / Happiness; For Others; Miscellaneous. The most frequent reason given overall and by women was "appearance." Carers cited "health" most frequently and "appearance" least, rarely agreeing with participants. "Health" was given as a reason more from older adults and those with milder ID. No statistically significant associations were found between reasons for seeking weight loss and BMI age, gender or level of ID but the differing views of adults with ID and their carers were clear. CONCLUSIONS: Views of adults with obesity and mild or moderate ID can be collected. The opposing views of adults and their carers may affect motivation for weight loss.

Association of somatic action potential shape with sensory receptive properties in guinea-pig dorsal root ganglion neurones.

1. Intracellular voltage recordings were made from the somata of L6 and S1 dorsal root ganglion (DRG) neurones at 28.5-31 C in young guinea-pigs (150-300 g) anaesthetized with sodium pentobarbitone. Action potentials (APs) evoked by dorsal root stimulation were used to classify conduction velocities (CVs) as C, Adelta or Aalpha/beta. Units with overshooting APs and membrane potentials (Vm) more negative than -40 mV were analysed: 40 C-, 45 Adelta- and 94 Aalpha/beta-fibre units. 2. Sensory receptive properties were characterized as: (a) low-threshold mechanoreceptive (LTM) units (5 C-, 10 Adelta- and 57 Aalpha/beta-fibre units); (b) nociceptive units, responding to noxious mechanical stimuli, some also to noxious heat (40 C-, 27 Adelta- and 27 Aalpha/beta-fibre units); (c) unresponsive units that failed to respond to a variety of tests; and (d) C-fibre cooling-sensitive units (n = 4). LTM units made up about 8 % of identified C-fibre units, 36 % of identified Adelta-fibre units and > 73 % of identified Aalpha/beta-fibre units. Compared with LTM units, the nociceptive units had APs that were longer on average by 3 times (C-fibre units), 1.7 times (Adelta-fibre units) and 1.4 times (Aalpha/beta-fibre units). They also had significantly longer rise times (RTs) and fall times (FTs) in all CV ranges. Between Aalpha/beta-nociceptors and Aalpha/beta-LTMs there was a proportionately greater difference in RT than in FT. The duration of the afterhyperpolarization measured to 80 % recovery (AHP80) was also significantly longer in nociceptive than LTM neurones in all CV ranges: by 3 times (C-fibre units), 6.3 times (Adelta-fibre units) and 3.6 times (Aalpha/beta-fibre units). The mean values of these variables in unresponsive units were similar to those of nociceptive units in each CV range; in C- and Adelta-fibre groups their mean AHP duration was even longer than in nociceptive units. 3. A-fibre LTM neurones were divided into Adelta- (D hair units, n = 8), and Aalpha/beta- (G hair/field units, n = 22; T (tylotrich) hair units, n = 6; rapidly adapting (RA) glabrous units, n = 6; slowly adapting (SA) hairy and glabrous units, n = 2; and muscle spindle (MS) units n = 17). MS and SA units had the shortest duration APs, FTs and AHP80s of all these groups. The mean RT in D hair units was significantly longer than in all Aalpha/beta LTM units combined. T hair units had the longest mean FT and AHP of all the A-LTM groups. The mean AHP was about 10 times longer in T hair units than in all other A-LTM units combined (significant), and was similar to that of A-fibre nociceptive neurones. 4. These differences in somatic AP shape may aid in distinguishing between LTM and nociceptive or unresponsive C- and Adelta-fibre units but probably not between nociceptive and unresponsive units. The differences seen may reflect differences in expression or activation of different types of ion channel.

The correlation between the distribution of the NK1 receptor and the actions of tachykinin agonists in the dorsal horn of the rat indicates that substance P does not have a functional role on substantia gelatinosa (lamina II) neurons.

The presence of substance P in primary afferents that terminate in the outer laminae of the spinal cord has led to considerable interest in the function of this neuropeptide in nociception. We have examined the actions of tachykinin agonists on the membrane potential of neurons in lamina II of a neonatal spinal cord slice preparation in vitro. Only 10.5% (n = 75) of these neurons showed any response to the application of a selective NK1 receptor agonist while 48.3% (n = 60) of neurons in deeper dorsal horn laminae responded to this agonist. Lamina II neurons were equally insensitive to selective NK2 and NK3 agonists. Synaptic potentials evoked in lamina II neurons by peripheral nerve stimulation were similarly not altered by the NK1 agonist. Immunocytochemical studies using an antibody raised against the C-terminal of the NK1 receptor revealed that very few lamina II neurons express NK1 receptors, and this offers an explanation for our findings.

The effects of cholinoceptor agonists and antagonists on C-fibre evoked responses in the substantia gelatinosa of neonatal rat spinal cord slices.

1. The effects of cholinoceptor agonists and antagonists were studied on neurones in the substantia gelatinosa (SG) of an in vitro spinal cord slice and nerve preparation from neonatal rats. 2. Bath application of carbachol (1-50 microM) reduced, in a dose-related manner, the amplitude and duration of the excitatory postsynaptic potentials (e.p.s.ps) evoked in response to nerve stimulation. 3. The latencies and stimulation thresholds required to evoke these e.p.s.ps suggested that the majority were due to C-fibre activation. 4. The reduction in e.p.s.p. amplitude and duration produced by carbachol was reversed by the muscarinic antagonists, atropine (in 8 out of 11 cells), pirenzepine (in 7 out of 9 cells) and methoctramine (in 8 out of 9 cells) and by the nicotinic antagonist mecamylamine (in 3 out of 7 cells). 5. Injection of small hyperpolarizing or depolarizing pulses was associated with no change in conductance in 19 out of 26 (73%) of cells tested, suggesting that an action at a site presynaptic to the neurone studied could account for part of the effect of carbachol. 6. It is proposed that some of the cholinoceptors associated with the e.p.s.p. depression are located on C-fibres.