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Biomedical subjects

C Q Mountjoy

Publications and source records attributed to C Q Mountjoy.

At least 37 records · Page 2Linked to original sources
PubMed1986

Decreased somatostatin immunoreactivity but not neuropeptide Y immunoreactivity in cerebral cortex in senile dementia of Alzheimer type.

The content of two neuropeptides, somatostatin (SRIF) and neuropeptide Y (NPY) has been determined in two cerebral cortical areas of Alzheimer's disease brain and in age-matched control brains. The content of SRIF-like immunoreactivity (SRIF-LI) was found to be decreased in Alzheimer temporal cortex (Brodmann area 21) compared to control temporal cortex. The decreased content of SRIF was significantly correlated with the observed number of neuritic plaques and neurofibrillary tangles. No difference was observed in NPY-LI between Alzheimer cerebral cortex and control cortex. Furthermore, no correlations were observed between NPY content and plaque count, neurofibrillary tangle estimate or SRIF content despite widespread reports of NPY/SRIF coexistence.

Aged↗
PubMed1986

Comparison of counts of neurons in the locus coeruleus made from serial sections and from a single section at the centre of the nucleus.

This paper describes the comparability of counts in the locus coeruleus made from serial sections and those made from a single section at the point of greatest density of neurons. Samples of the locus coeruleus neuronal population derived from single section counts though not exactly comparable, are of comparable utility to those obtained from more laborious total neuronal counts. The simpler method was used to examine the hypothesis that there are subtypes of senile dementia of the Alzheimer type. Separation into two groups was achieved when independent variables of cortical neuronal counts and tangle estimates were used. This finding adds to the growing evidence that Alzheimer's disease of the senile type is not a unitary disorder.

Alzheimer Disease↗
PubMed1986

Post-mortem neurochemical changes in Alzheimer's disease compared with normal ageing.

Selective neuronal degeneration with concomitant changes in neurotransmitter systems are features of both normal ageing and Alzheimer's disease. There are, however, important neurochemical differences in cerebral cortex. Choline acetyltransferase declines with age in frontal cortex in contrast to the prominent change in the temporal cortex in Alzheimer's disease. The loss of somatostatin, and the recently reported reciprocal change in corticotropin-releasing factor and receptors are not seen with ageing. However, age itself may have an important influence on the neurochemical deficits in Alzheimer's disease which are restricted in the older patients. The problems of post-mortem studies in the analysis of ageing and possible approaches to this are discussed.

Aging↗
PubMed1986

CAMDEX. A standardised instrument for the diagnosis of mental disorder in the elderly with special reference to the early detection of dementia.

A new interview schedule for the diagnosis and measurement of dementia in the elderly is described. The schedule named the Cambridge Mental Disorders of the Elderly Examination (CAMDEX), consists of three main sections: A structured clinical interview with the patient to obtain systematic information about the present state, past history and family history; a range of objective cognitive tests which constitute a mini-neuropsychological battery; a structured interview with a relative or other informant to obtain independent information about the respondent's present state, past history and family history. The CAMDEX is acceptable to patients, has a high inter-rater reliability and the cognitive section has been shown to have high sensitivity and specificity.

Aged↗
PubMed1984

Neurochemical characteristics of early and late onset types of Alzheimer's disease.

Brains of 49 patients who had died with Alzheimer's disease and 54 controls were examined. The Alzheimer group exhibited noticeably reduced activity of the cholinergic marker enzyme choline acetyltransferase in the cerebral cortex, but cortical concentrations of noradrenaline, gamma-aminobutyric acid, and somatostatin were also significantly reduced. Analysis of the results according to age at death showed that the older patients, dying in their 9th and 10th decades, had a relatively pure cholinergic deficit confined to temporal lobe and hippocampus, together with a reduced concentration of somatostatin confined to temporal cortex. By contrast, the younger patients, dying in their 7th and 8th decades, had a widespread and severe cholinergic deficit together with the abnormalities of noradrenaline, gamma-aminobutyric acid, and somatostatin, and the younger patients accounted for most of the abnormalities in these systems observed in the overall group. Comparison of the young subjects with Alzheimer's disease with the older controls did not support the concept of Alzheimer's disease representing an acceleration of the aging process. These results suggest that Alzheimer's disease in people aged under 80 may represent a distinct form of presenile dementia which differs in important respects from the dementia of old age.

Age Factors↗
PubMed1984

Reduced binding of [3H]ketanserin to cortical 5-ht2 receptors in senile dementia of the Alzheimer type.

Using [3H]ketanserin, a specific ligand for the 5-HT2 receptor, the amount of specific binding was measured in preparations of post-mortem frontal cortex from subjects diagnosed as suffering from dementia. A highly significant 42% loss of binding was observed which reflected a decrease in receptor density compared to psychiatrically normal controls. This was found to be independent of age in the demented patients and thus unlikely to be related to the cholinergic deficit. Measurement of 5-HT and its metabolite 5-HIAA indicated a smaller, non-significant decrease in presynaptic 5-HT function.

Age Factors↗
PubMed1984

Correlation of cortical cholinergic and GABA deficits with quantitative neuropathological findings in senile dementia.

The present paper examines the relationship between choline acetyltransferase (ChAT) activity and gamma aminobutyric acid (GABA) concentrations with neuronal counts, senile plaque counts and estimates of neurofibrillary tangles in a series of 25 cases of senile dementia of Alzheimer type (SDAT) with appropriate controls. ChAT activity was significantly positively correlated with neuronal counts in the frontal and temporal region for the whole group but not in the demented or control subgroups. Significant negative correlations were also found between plaque counts and ChAT activity in all areas studied in the total group of subjects and in most of the SDAT groups. Significant negative correlations between ChAT activity and estimates of neurofibrillary change occurred in the frontal area and midtemporal gyrus in the SDAT cases. All the above correlations were seen most prominently in the youngest dementia patients (less than 79 years of age) who exhibited the most severe neuropathological and neurochemical deficits. The neurochemical distinction between the young and elderly age group of SDAT cases was well illustrated by the paradoxical trends of significantly increased GABA and ChAT levels with increasing age. The few significant correlations observed between GABA and cell counts were positive and occurred in the temporal lobe in the younger age group. Plaque counts and neurofibrillary tangle estimates showed little correlation with GABA concentrations.

Alzheimer Disease↗
PubMed1983

Loss of pigmented dopamine-beta-hydroxylase positive cells from locus coeruleus in senile dementia of Alzheimer's type.

Serial sections of human brainstem were used to determine the total number of pigmented cells in locus coeruleus and, by immunohistochemical staining using an antiserum directed against human dopamine-beta-hydroxylase (DBH), the number of DBH-positive cells. In 12 brains from elderly control and dementia subjects there wer not significant differences in the total cell populations determined in the same brain by the two techniques. In 6 patients with senile dementia of Alzheimer's type there was a variable loss (average about 60% reduction) in locus coeruleus cells when compared to controls of similar age. The loss of noradrenergic neurones from locus coeruleus was accompanied by an average reduction of similar magnitude in noradrenaline concentration in temporal cortex, with no change or an increase in dopamine content. There was also a significant reduction in the cholinergic marker choline acetyltransferase in cortex samples from the dementia cases.

Aged↗
PubMed1983

Cortical neuronal counts in normal elderly controls and demented patients.

The purposes of the investigation were to determine whether there was significant neuronal loss in dementia, and if so, whether it was general or localised, and to examine the relationship between neuronal counts, senile plaques and neurofibrillary change. Neuronal counts were made in nine cortical areas in the brains of 25 patients with senile dementia of the Alzheimer type and twenty-five age-matched controls, with the aid of an image analysing computer. Neuronal counts per square millimetre were significantly lower in the demented group of patients in the inferior frontal and superior temporal gyri. Neuronal counts in four columns of cortex were significantly reduced in superior, middle and inferior frontal gyri, cingulate gyrus and superior and middle temporal gyri. There was no significant difference in the parietal (Brodmann area 7) or occipital (Brodmann area 17) cortex. Corresponding glial counts per square millimetre show a significant increase in the demented group only in the middle and inferior temporal gyri. Neuronal counts correlated weakly but significantly with plaque counts in the same cortical area in the middle frontal gyrus and the superior and middle temporal gyri. High correlations between neuronal counts and estimates of neurofibrillary change were found in superior, middle and inferior frontal gyri, cingulate gyrus and superior and middle temporal gyri.

Aged↗
PubMed1982

The substantia innominata in Alzheimer's disease: an histochemical and biochemical study of cholinergic marker enzymes.

Acetylcholinesterase staining was examined in the substantia innominata of 3 normal human brains. Large intensely stained neurones were seen within the region of the basal nucleus of Meynert which is believed to be the origin of the cholinergic projection to the neocortex in animals. On the basis of the acetylcholinesterase staining pattern, the substantia innominata was dissected from post-mortem brain tissue of 19 cases of Alzheimer's disease (AD) and 16 controls so as to include the basal nucleus. Choline acetyltransferase (ChAT) activity was found to be reduced in the substantia innominata and amygdala in AD but not in the adjacent lentiform nucleus and hypothalamus.

Acetylcholinesterase↗
PubMed1982

Studies in the relationship between depressive disorders and anxiety states. Part 1. Rating scales.

Systematic clinical examination, 7 rating scales for severity and the Newcastle Anxiety Depression Scale were applied in 117 patients with depressive, anxiety or phobic neurosis. "Endogenous" (autonomous) depressions were excluded. Principal component and discriminant function analysis were used to determine whether the depressive and anxiety syndromes could be differentiated from each other. With the aid of discriminant function analysis, separation of the 2 groups was achieved in the full sample and in 2 randomly derived sub-samples. The most powerful discriminators in all analyses were the Hamilton Depression Scale and the Newcastle Anxiety Depression Scale. Discriminant function analysis of the items from the Hamilton Depression Scale showed that it was possible to allocate 90% of the patients to the groups to which they had originally been classified by clinical diagnosis.

Adult↗
PubMed1982

Studies in the relationship between depressive disorders and anxiety states. Part 2. Clinical items.

A principal component analysis of the clinical items recorded on a standard proforma for 108 patients suffering from anxiety, depressive and phobic neurosis yielded 2 clinically important components. There was considerable overlap between diagnostic groups when patients' component scores were plotted but the degree of misclassification was reduced to about 18% following discriminant function analysis. For the first component the most important discriminators with depressive weighting were depressed mood and pessimistic outlook, whereas reactivity of depression and increased physiological responses carried anxiety weighting. In the second component depressed mood and pessimistic outlook were the highest depressive discriminators and highest positive anxiety ones were increased physiological responses, situational phobias and compulsive phenomena.

Adolescent↗
PubMed1982

Further investigations into the relationship between depressive disorders and anxiety state.

Results of two investigations into the relationship between anxiety states and depressive disorders are summarized. In the first study (117 patients), which was confined to neurotic forms of depressive and/or anxious affective disorder, analysis of the findings derived from systematic clinical examination and eight rating scales, seven of them supposedly unidimensional measures of the severity of emotional disturbance, made it possible to achieve clear separation of the patient population into two groups both in the full sample and in two randomly derived subsamples. A number of rating scales have been shown to be effective tools for diagnostic discrimination within the affective disorders. The second enquiry (152 patients) covered the entire range of disorders of affect. Multivariate analyses of data derived from Present State Examination (P.S.E.) differentiated the patient population into three main groups: 1) endogenous depression; 2) neurotic depression; and 3) anxiety neuroses. There was 84% agreement between the classification of patients into the groups "anxiety state" and "depressive disorder" and separation of the 152 patients also was achieved with the aid of ratings on the Maudsley Personality Inventory and the Cattell 16 PF Battery.

Anxiety Disorders↗
PubMed1982

A post-mortem study of the cholinergic and GABA systems in senile dementia.

Choline acetyltransferase (ChAT) activity and gamma-aminobutyric acid (GABA) concentration were measured in 19 cerebral cortical areas and 22 subcortical areas of brains from 26 control and 25 histologically proven cases of Alzheimer's disease. Reduced ChAt activity was observed in all the cortical areas examined in the Alzheimer cases dying before the median age of 79 years. In the Alzheimer cases aged greater than 79 years at death, 7 out of the 9 frontal cortical areas had a normal ChAT activity when compared with controls. Significant reductions in GABA concentrations in the Alzheimer cases were confined to the temporal cortex. Significant reductions in ChAT activity in subcortical areas were confined to 8 of the 22 regions examined. Notably these included the septal nuclei and substantia innominata, the proposed origins of the cholinergic projections to the hippocampus and neocortex, respectively. There were no reductions in GABA concentrations outside the cerebral cortex. Four multi-infarct cases and 6 cases with normal histology were found to have a small reduction in ChAT activity confined to only a few areas. The data are consistent with a predominant loss in Alzheimer's disease of the diffuse cholinergic projection from the brainstem and basal forebrain.

Aged↗