Scalp electrical recording during paralysis: quantitative evidence that EEG frequencies above 20 Hz are contaminated by EMG.

OBJECTIVE: To identify the possible contribution of electromyogram (EMG) to scalp electroencephalogram (EEG) rhythms at rest and induced or evoked by cognitive tasks. METHODS: Scalp EEG recordings were made on two subjects in presence and absence of complete neuromuscular blockade, sparing the dominant arm. The subjects undertook cognitive tasks in both states to allow direct comparison of electrical recordings. RESULTS: EEG rhythms in the paralysed state differed significantly compared with the unparalysed state, with 10- to 200-fold differences in the power of frequencies above 20 Hz during paralysis. CONCLUSIONS: Most of the scalp EEG recording above 20 Hz is of EMG origin. Previous studies measuring gamma EEG need to be re-evaluated. SIGNIFICANCE: This has a significant impact on measurements of gamma rhythms from the scalp EEG in unparalysed humans. It is to be hoped that signal separation methods will be able to rectify this situation.     

Social competence and head injury: a practical approach

Social competence assessment and training has long focused on specific skills within the clinical setting. In addition, emphasis has been placed on identifying deficits relative to an arbitrary, often idiosyncratic metric. In this article, we discuss the importance of the principles that underlie communication and which are reflected in the range of behaviours described as social competence . We review methods we have found productive in the training of these principles with persons who have suffered traumatic brain injuries.     

Endocrine tumors of the ileum. Cytochemical and clinical aspects

Sixteen patients with endocrine ileal tumors and liver metastases were analyzed with regard to the size, multicentricity, and growth pattern of the primary tumor, the occurrence of carcinoid syndrome, as well as the concentrations of serotonin and substance P (SP) in blood, 5-hydroxy-indole-acetic acid (5-HIAA) in urine, and the course of the disease. Excised specimens from the tumors were immediately processed for immunocytochemical investigations of the presence of neurohormonal peptides, using a broad spectrum of antisera and optimal histoprocessing techniques. In all patients the serotonin levels in blood and/or the 5-HIAA in urine were high. The SP concentration in plasma was markedly elevated in all but two of the ten patients investigated in this respect. A mixed growth pattern prevailed in the tumors of 7 patients with fatal disease. Serotonin cells were found in all tumors and SP-immunoreactive tumor cells in all but one; one of the carcinoids also contained a few tumor cells displaying enkephalin immunoreactivity. In conventionally fixed and paraffin embedded specimens of the same tumors usually no immunoreactive tumor cells at all could be demonstrated, showing that SP is among the peptides vulnerable to poor histotechniques. Nevertheless, SP, together with serotonin, constitute reliable clinical tumor markers for ileal carcinoids.     

Immunization with glycosylated Kb-binding peptides generates carbohydrate-specific,unrestricted cytotoxic T cells

Cytotoxic T cells (CTL) recognize target proteins as short peptides presented by major histocompatibility complex (MHC) class I restriction elements. However, there is also evidence for peptide-independent T cell receptor (TCR) recognition of target proteins and non-protein structures. How such T cell responses are generated is presently unclear. We generated carbohydrate (CHO)-specific, MHC-unrestricted CTL responses by coupling di- and trisaccharides to K^b- or D^b-binding peptides for direct immunization in mice. Four peptides and three CHO have been analyzed with the CHO either in terminal or central positions on the carrier peptide. With two of these glycopeptides, with galabiose (Galα1-4Gal; Gal₂) bound to a homocysteine (via an ethylene spacer arm) in position 4 or 6 in a vesicular stomatitis virus nucleoprotein-derived peptide (RGYVYQGL binding to K^b), CTL were generated which preferentially killed target cells treated with glycopeptide compared to those treated with the core peptide. Polyclonal CTL were also found to kill target cells expressing the same Gal₂ epitope in a glycolipid. By fractionation of CTL, preliminary data indicate that glycopeptide-specific K^b-restricted CTL and unrestricted CHO-specific CTL belong to different T cell populations with regard to TCR expression. The results demonstrate that hapten-specific unrestricted CTL responses can be generated with MHC class I-binding carrier peptides. Different models that might explain the generation of such responses are discussed.     

Demonstration of pro-opiomelanocortin mRNA in pituitary adenomas and para-adenomatous gland in cushing's disease and Nelson's syndrome

Pro-opiomelanocortin (POMC) mRNA was demonstrated in pituitary adenomas from 16 patients with Cushing's disease and 10 with Nelson's syndrome. The intensity of signal was significantly greater in Nelson's syndrome than in Cushing's disease and there was a trend towards a greater proportion of positive cells. This probably reflects inhibition of POMC gene expression by the high circulating levels of cortisol in Cushing's disease. In the para-adenomatous gland, the intensity of signal was variable in cells showing Crooke's hyaline change, ranging from negative to strongly positive, in keeping with the functional heterogeneity of corticotrophs. In one case, junctional corticotrophs were present and these were more intensely stained than anterior lobe corticotrophs in the same gland. This supports the concept that these cells are subject to different regulatory influences from corticotrophs in the anterior lobe. Whether this is related to differences in embryological origins or to local factors is at present unclear.     

Immunohistochemical localization of chondroitin sulfate proteoglycan and tenascin in the human eye compared with the HNK-1 epitope

Background: A previous study revealed the HNK-1 epitope in the human ciliary body beneath the ciliary epithelium. The molecules bearing this 3-sulphoglucuronic acid-containing oligosaccharide epitope in the eye remain unknown. As chondroitin sulphate proteoglycan (CSPG) and tenascin are potential candidates as bearers of the HNK-1 epitope, their distribution in the human eye was compared with that of the HNK-1 epitope. Methods: Fifty-five formalin-fixed, paraffin-embedded human eyes, including 20 normal eyes and 35 eyes with exfoliation syndrome or glaucoma, were studied immunohistochemically with monoclonal antibody (MAb) CS-56 to CSPG, MAb TN2 to tenascin, and MAbs HNK-I and VC1.1 to the HNK-1 epitope. Additionally, four frozen lens capsules with exfoliation material were studied by indirect immunofluoresence. Results: A population of dendritic cells in the inner connective tissue layer of the ciliary body and exfoliation material were immunoreactive with antibodies to the HNK-1 epitope, but no labelling for CSPG and tenascin was seen in them, including frozen sections. The inner surface of the nonpigmented ciliary epithelium was reactive for the HNK-1 epitope, and at the ora serrata also for CSPG. In some eyes with glaucoma, immunoreaction for CSPG and tenascin was seen beneath the epithelium and endothelium of the cornea. The nerve fibre layer of the retina was labelled for tenascin. In the sclera, all antibodies labelled the ground substance, and in some large blood vessels immunoreaction for CSPG and tenascin was seen subendothelially. Conclusion: Apart from the sclera, the distribution of CSPG and tenascin was different from that of the HNK-1 epitope, suggesting that this carbohydrate epitope may not be borne by these molecules in the human ciliary body.     

Sexual Knowledge,Experience and Feelings Among People with Disability

The current study was designed to evaluate the sexual knowledge, experience, feelings and needs of people with intellectual disability or physical disability, and compare them to people from the general population. Sixty people with mild intellectual disability (28 males, 32 females, mean age=27.62 years), 60 people with physical disability (33 males, 27 females, mean age=28.65 years) and 100 people from the general population (40 males, 60 females, mean age=30.10 years) participated in the study. Each respondent completed the Sexual Knowledge, Experience and Needs Scale (SexKen). This scale assesses levels of knowledge, experience, feelings and needs in 12 different areas of sexuality. The results demonstrated that people with intellectual disability experienced lower levels of sexual knowledge and experience, more negative attitudes to sex and stronger sexual needs than people with physical disability, in all areas of sexuality. People with physical disability demonstrated these same trends when they were compared to people from the general population. An interpretation of these results as they relate to the sexuality of people with intellectual or physical disability is provided.