Antibodies to ubiquitin have been used to search for evidence of abnormal protein degradation in amyotrophic lateral sclerosis--motor neuron disease (ALS). Anterior horn cell ubiquitin-immunoreactive (IR) inclusions were present in all of 31 ALS cases but in none of 23 neurologically normal and in only 1 of 22 neurologically abnormal controls. These inclusions, which were present in familial and sporadic ALS cases, and in cases with dementia, took the form of dense rounded or irregular ubiquitin-IR cytoplasmic inclusions (dense bodies), or loosely arranged bundles ('skeins') of filamentous-appearing material. The presence of ubiquitin-IR inclusions corresponded to the pattern of selective neuronal vulnerability in ALS, although inclusions in pyramidal neurons of the motor cortex were infrequent and were noted in only a minority of cases. Ubiquitin-IR inclusions were more prevalent than Bunina bodies. The latter were present in 67% of ALS cases but were seldom labelled by antibodies to ubiquitin. Intraneuronal inclusions resembling Lewy bodies were present in 23% of ALS cases and were often identified by antibodies to ubiquitin. We conclude that the presence of ubiquitin-IR inclusions in lower motor neurons represents a characteristic pathological feature of ALS in its various clinical forms. Ubiquitin-IR inclusions in ALS differ from ubiquitinated inclusions in other neuronal degenerations in that they are not readily identified by antibodies to cytoskeletal proteins. They may represent accumulations of altered or abnormal neuronal proteins resistant to degradation via the ubiquitin proteolytic pathway.

The function of the kidney, as well as its morphology, changes markedly with age. The glomerular filtration rate falls progressively, independent of overt pathology. Glomerular, vascular and accompanying parenchymal changes occur and other disorders associated with ageing, such as diabetes and hypertension, have a stochastic deleterious effect on both form and function. Declining renal function with age has important implications, not only for individual homeostasis but also for the use of drug therapy and for the receipt and donation of organs for transplantation. Molecular mechanisms and cellular changes underlying some of the functional and structural changes associated with ageing are becoming clearer, as are some of the ways in which genetic background, age and disease can combine to produce functional damage.

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BACKGROUND AND PURPOSEDelayed gastric emptying is poorly managed. Motilin agonists are potential treatments but inadequate understanding into how enteric nerve functions are stimulated compromises drug/dose selection. Resolution is hampered by extreme species dependency so methods were developed to study human gastrointestinal neuromuscular activities and the neurobiology of motilin. EXPERIMENTAL APPROACHProtocols to study neuromuscular activities were developed for different regions of human stomach and intestine (71 patients) using circular muscle preparations and electrical field stimulation (EFS) of intrinsic nerves. Other tissues were fixed for immunohistochemistry. KEY RESULTSEFS evoked contractions and/or relaxations via cholinergic and nitrergic neurons, with additional tachykinergic activity in colon; these were consistent after 154 min (longer if stored overnight). Motilin 1-300 nM and the selective motilin agonist GSK962040 0.1-30 mM acted pre-junctionally to strongly facilitate cholinergic contractions of the antrum (Emax ª 1000% for motilin), with smaller increases in fundus, duodenum and ileum; high concentrations increased baseline muscle tension in fundus and small intestine. There were minimal effects in the colon. In the antrum, cholinergic facilitation by motilin faded irregularly, even with peptidase inhibitors, whereas facilitation by GSK962040 was long lasting. Motilin receptor immunoreactivity was identified in muscle and myenteric plexus predominantly in the upper gut, co-expressed with choline acetyltransferase in neurons. CONCLUSIONS AND IMPLICATIONSMotilin and GSK962040 strongly facilitated cholinergic activity in the antrum, with lower activity in fundus and small intestine only. Facilitation by motilin was short lived, consistent with participation in migrating motor complexes. Long-lasting facilitation by GSK962040 suggests different receptor interactions and potential for clinical evaluation. LINKED ARTICLE AbbreviationsChAT, choline acetyltransferase; EFS, electrical field stimulation; Emax, maximum response to agonist; L-NAME, Nw-nitro-L-arginine methyl ester; MMC, migrating motor complex; NK, neurokinin; TTX, tetrodotoxin BJP British Journal of Pharmacology