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Biomedical subjects

G W Roberts

Publications and source records attributed to G W Roberts.

134 records · Page 8Linked to original sources
PubMedDate not supplied

Immunocytochemistry of neurofibrillary tangles in dementia pugilistica and Alzheimer's disease: evidence for common genesis.

A battery of antisera that specifically stained the tangles of Alzheimer's disease also stained the tangles in all of 8 cases of dementia pugilistica (punch-drunk syndrome). Since the paired helical filament antigens found in Alzheimer type neurofibrillary degeneration are present in the tangles of dementia pugilistica the pathogenesis of tangle formation in these conditions is likely to be the same; thus head injury may be a predisposing factor or environmental trigger for Alzheimer's disease.

Adult↗
PubMedDate not supplied

Life-long overexpression of S100beta in Down's syndrome: implications for Alzheimer pathogenesis.

Chronic overexpression of the neurite growth-promoting factor S100beta has been implicated in the pathogenesis of neuritic plaques in Alzheimer's disease. Such plaques are virtually universal in middle-aged Down's syndrome, making Down's a natural model of Alzheimer's disease. We determined numbers of astrocytes overexpressing S100beta, and of neurons overexpressing beta-amyloid precursor protein (beta-APP), and assayed for neurofibrillary tangles in neocortex of 20 Down's syndrome patients (17 weeks gestation to 68 years). Compared to controls, there were twice as many S100beta-immunoreactive (S100beta+) astrocytes in Down's patients at all ages: fetal, young, and adult (p = 0.01, or better, in each age group). These were activated (i.e., enlarged), and intensely immunoreactive, even in the fetal group. There were no neurofibrillary changes in fetal or young Down's patients. The numbers of S100beta+ astrocytes in young and adult Down's patients correlated with the numbers of neurons overexpressing beta-APP (p < 0.05). Our findings are consistent with the idea that conditions--including Down's syndrome--that promote chronic overexpression of S100beta may confer increased risk for later development of Alzheimer's disease.

Adult↗
PubMedDate not supplied

Neuropeptide Y distribution in human brain.

Tatemoto and Mutt recently used the presence of a C-terminal NH2 group to identify and isolate a new peptide, neuropeptide Y (NPY), from porcine brain. This 36 amino acid peptide was subsequently shown to be active on isolated vas deferens, vascular smooth muscle and pancreatic acinar cells in very low molar concentrations. In view of these potent effects we have now investigated its distribution in the human brain by radioimmunoassay and immunocytochemistry. High concentrations of NPY have been found, exceeding those of cholecystokinin and somatostatin, hitherto considered to be the most abundant neuropeptides. The distribution of NPY was different from that of any other peptide system described, being particularly concentrated in the basal ganglia, amygdala and nucleus accumbens. Immunocytochemistry demonstrated a large number of NPY neuronal cell bodies especially in the caudate and putamen. Immunoreactive neuronal cell bodies were also clearly localized in cortical areas, particularly layers V and VI. NPY, a newly discovered peptide with potent biological activity, thus seems to be among the most abundant of human neuropeptides. The massive numbers of NPY neurones in the basal ganglia suggest NPY to be of fundamental importance in the control of human motor function.

Brain Chemistry↗
PubMedDate not supplied

Location of neuronal tangles in somatostatin neurones in Alzheimer's disease.

Senile dementia of the Alzheimer type is a chronic, progressive neuropsychiatric condition characterized clinically by global intellectual impairment and neuropathologically by the presence of numerous argyrophilic plaques and tangles. Neurochemical investigations have established loss of the cholinergic and aminergic projections to the cerebral cortex and a loss of the content of somatostatin, with preservation of cholecystokinin and vasoactive intestinal polypeptide, neuropeptides also located in cells intrinsic to the cortex. We describe here the relationship between cortical somatostatin immunoreactivity and the plaques and tangles of diseased tissue by immunocytochemical and silver impregnation techniques on paraffin-embedded tissue. In sections of Alzheimer's tissue, cortical somatostatin-immunoreactive perikarya exhibited morphological changes consistent with neuronal degeneration. Silver-stained material immunostained subsequently showed that many neurones containing tangles were also somatostatin positive. No such colocalization was observed using antisera to other neuropeptides. Our findings indicate that a subclass of somatostatin-positive neurones are affected selectively in Alzheimer's disease and that these neurones also contain neuronal tangles. Thus, destruction of somatostatin-containing neurones is an early and perhaps critical event in the disease process.

Aged↗
PubMedDate not supplied

Nurse/patient communication within a bilingual health care setting.

Communication and the interactions that take place between nurse and patient are the foundation of nursing care. However, in practice, cross-cultural communication is often inadequate and therefore the health care needs of many cultural groups are not being met. An examination of language switching within nurse/patient interaction in a bilingual setting provides a further dimension for the study of cross-cultural communication.

Communication Barriers↗
PubMedDate not supplied

The power of language in a bilingual community.

Recent language policy in Wales has helped ensure that issues such as nurse-patients interactions, particularly at a cross-cultural level, are examined from a new perspective. This paper focuses on the significance of promoting cultural and linguistic sensitivity in health care to promote effective clinical practice and the implications that this has for developing nursing education programmes in Wales.

Communication Barriers↗