Physical aggression towards others in adults with learning disabilities: prevalence and associated factors

Background Many people with learning disabilities (LD) show aggressive behaviour, but the extent of the problem and its associated factors and effects are unclear. Methods A cross‐sectional analysis was carried out using interview data from 3065 adults with LD on the Leicestershire LD Register. Physical aggression towards others was defined as carers reporting frequent (more than three times per week) and/or severe episodes. Individuals with and without aggression were compared using multiple logistic regression models for potential physical and psychological factors. Results Carers reported that 443 (14%) of adults were physically aggressive towards others. Men (P = 0.001), younger individuals (P < 0.001), people with more severe LD (P < 0.001) and those in institutional settings (P < 0.001) had a significantly higher prevalence of physical aggression. People with Down syndrome had a lower prevalence of physical aggression (P < 0.001). After adjustment, we found no relationship between aggression and the presence of epilepsy or autism. Among psychological factors, symptoms of frustration (P < 0.001) and mood swings (P < 0.001) were associated with higher levels of aggression. Failure to cope among carers was reported by 14% overall: 42% of people caring for adults with aggression said they were unable to cope compared with 10% of those caring for adults without aggression. Conclusions Physical aggression towards other people presents a significant challenge to carers of adults with LD. Further research is needed to identify aetiological factors with a view to finding effective interventions to reduce, and improve management of, this behaviour.     

Direct inactivation of herpes simplex virus type-2 by rat epidermal protein.

Proteins were extracted from corneocytes of skin of 2-day-old rats and fractionated by gel filtration and cation exchange column chromatography. The different protein fractions were tested for direct inactivation of herpes simplex virus infectivity as determined by reduction of plaque formation. The most effective protein fractions against herpes simplex virus were a neutral pH buffer soluble and mol. wts. ranging from 20 K to 30 K. Amino acid composition of the proteins were virtually identical to epidermal histidine-rich proteins. The activity was significantly (P less than 0.001) stronger against type-2 than type-1. The activity was most stable at pH 7.2 and the rate of inhibition increased in a time-dependent manner up to 4 h. The 50% effective dose was estimated as 1.1 micrograms protein/ml.     

Post-herpetic neuralgia and topical capsaicin

Topical 0.025% capsaicin was used to treat 33 patients with post-herpetic neuralgia (PHN). Thirty-nine percent of those entering the trial achieved at least a good result and 55% were improved or better. Fifty-six percent of the 23 patients completing the study had good or excellent pain relief after 4 weeks. Seventy-eight percent of the 23 noted at least some improvement in pain. Post-capsaicin burning was a common, untoward effect in most patients and in about one-third was so unbearable that the trial was terminated prematurely. This treatment appears to be a useful modality in PHN, particularly in the elderly in whom oral medications are often poorly tolerated; however, it does require supervision. A double-blind, controlled trial is now necessary.     

A new model of embolic stroke produced by photochemical injury to the carotid artery in the rat

We report a new model of embolic stroke in the rat, based on endothelial disruption and platelet aggregation in the carotid artery, which leads to distal embolization and focal brain infarction. The common carotid artery was irradiated for 6.5 minutes with the focused beam of an argon laser operated at a wavelength of 514.5 nm with a peak power of 2 W and an average power of 400 mw. Ipsilateral cerebral infarcts, ranging in size from 0.1 to 1.7 mm, were produced by platelet emboli in 12 of 13 rats. A total of 44 infarcts were observed in the 12 rats: 29 in the cortex, 6 in the hippocampus, 5 in the thalamus, and 4 in the basal ganglia. Scanning electron microscopy identified platelet aggregates in the carotid artery and in a deep cortical arteriole 50 minutes after the photochemical lesion. Twenty-four hours after the experiment, scanning electron microscopy of the carotid artery revealed damaged endothelium but few remaining adherent platelets. More intense laser irradiation in 8 rats, leading to carotid occlusion, produced an infarct in only 1. This new model can be used to study the acute and chronic pathological changes in the brain associated with platelet embolism.     

Gastrin: growth enhancing effects on human gastric and colonic tumour cells

Two colorectal (HT29, LoVo) and one gastric (MKN45) human tumour cell lines were examined for their in vitro trophic response to human gastrin-17. MKN45 and HT29 responded by increased 75Se selenomethionine uptake to exogenous gastrin (139 +/- 5.5% and 123 +/- 3% of control values respectively) whereas LoVo showed no significant response to this hormone. When these same cell lines were grown as xenografts in nude mice, similar responses were seen to exogenously administered human gastrin-17 (10 micrograms mouse-1 day-1, subcutaneous injection). MKN45 xenografts showed a greater response to continuously administered gastrin (osmotic mini-pumps, (10 micrograms mouse-1 day-1) when compared to the same dose given via a subcutaneous bolus injection. The hormone-treated xenografts had a two-fold increase in tumour cross-sectional area and growth rate when compared to saline-treated controls. Dose-response studies revealed that 0.4 micrograms gastrin mouse-1 day-1 appeared to be the minimally effective dose. As gastric and colorectal tumour cells show a trophic response to gastrin, antagonists of the gastrin receptor may prevent this effect causing tumour stasis. The gastric tumour cell line, MKN45, is gastrin-responsive and would be an ideal model for screening potent receptor antagonists.     

Effects of angiotensin converting enzyme inhibition in adult polycystic kidney disease.

The pathogenesis of hypertension in autosomal-dominant polycystic kidney disease (ADPKD) is unclear, but increased activity of the renin-angiotension system may contribute. The renal and systemic hemodynamic response to lisinopril, an angiotension converting enzyme (ACE) inhibitor, in patients with ADPKD without renal failure was compared with the response in matched unaffected family members. Mean blood pressure and renal vascular resistance decreased in the affected group after lisinopril, with no significant change in the unaffected group. Glomerular filtration rate (GFR) was unchanged and therefore filtration fraction fell significantly. Changes in urinary excretion of 6-keto-PGF1 alpha and kallikrein suggested that increased renal synthesis of PGI2 or activation of the renal kallikrein-kinin system were not likely to be responsible for the hemodynamic effects. The acute decrease in renal vascular resistance without change in GFR suggests that ACE inhibition may have a particular value in the treatment of hypertension associated with ADPKD which should be assessed by further long-term studies.     

Neurological problems presenting to an ophthalmic casualty department.

All patients presenting with neurological problems to an eye hospital casualty department over one year were prospectively studied. A total of 119 patients were identified. The most frequent diagnoses were retrobulbar neuritis (34; 28.5%), sixth cranial nerve palsy (22; 18.5%), third cranial nerve palsy (15; 12.6%) and Adie's tonic pupil (11; 9%). Cranial nerve palsies were most commonly due to diabetes or hypertension (16; 43.2%). Only one intracranial aneurysm was found. Symptoms included blurred vision (52; 43.7%), binocular diplopia (51; 42.8%), and eye pain (27; 22.7%). Fifty patients (42.0%) were referred by a general medical practitioner. Twenty-two (18.5%) were admitted to hospital. Forty-nine skull X-rays were requested and all were normal. Twenty-nine chest X-rays were requested. One (3.4%) showed an abnormality (carcinoma of the bronchus). Neurological patients present to ophthalmic casualty departments because of ophthalmic symptoms. Ophthalmic casualty officers are able to make working diagnoses and to direct patients appropriately. The use of investigations in the casualty department, however, is unlikely to be productive.     

Distribution of input synapses from processes exhibiting GABA- or glutamate-like immunoreactivity onto terminals of prosternal filiform afferents in the locust

The locust prosternum carries a population of long filiform hairs that are very sensitive to air currents. The sensory afferent neurons that innervate the hairs make strong monosynaptic connections with an identified intersegmental interneuron (A4I1) which is known to contact motor neurons that supply muscles controlling wing angle during flight. In order discover how the synapse between the afferents and interneuron A4I1 might be modulated, the afferents were labelled intracellularly by backfilling with horseradish peroxidase to reveal their central terminals which lie in the prothoracic ganglion. A postembedding immunogold method was used to make a quantitative assessment of the prevalence of immunoreactivity for GABA and glutamate in processes presynaptic to the afferent terminals. In one afferent neuron, where 77 synapses were examined, 40 (52%) of the presynaptic processes were immunoreactive for GABA. When adjacent sections through the same terminal branches were labelled with the two antibodies, it was demonstrated that GABA- and glutamate-like immunoreactivity was present in different populations of presynaptic processes. A series of 110 ultrathin sections was cut through one set of afferent terminal branches and alternate grids were stained with GABA and glutamate antibodies. From these sections, the terminals were reconstructed and the position of 35 input and 21 output synapses mapped. Of the 35 input synapses, 18 (51%) were immunoreactive for GABA, 14 (40%) were immunoreactive for glutamate and 3 (9%) were unlabelled by either antibody. On these terminals, the different classes of input synapses appeared to be intermingled at random with the output synapses made by the afferent, and no pattern govering synapse distribution could be discerned. © 1994 Wiley-Liss, Inc.