PubMed Health⌕ Search

Biomedical subjects

G Bruce

Publications and source records attributed to G Bruce.

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

Cholinergic innervation displays strikingly different laminar preferences in several cortical areas.

A new rabbit polyclonal antiserum against choline acetyltransferase (ChAT) reveals that cholinergic innervation of the cortex varies strikingly among different cytoarchitecturally defined areas in the rat neocortex. These findings suggest that cholinergic transmission may be integrated differently into the local circuitries of various regions of the cerebral cortex. In addition, the pattern of staining observed with acetylcholinesterase histochemistry, which has been used for many years to demonstrate putative cholinergic fibers, only partially matches the staining pattern obtained with the more specific cholinergic marker, ChAT.

Acetylcholinesterase↗
PubMed1985

Immunohistochemical staining of cholinergic neurons in the human brain using a polyclonal antibody to human choline acetyltransferase.

Antibodies against human placental choline acetyltransferase (ChAT) were used to immunohistochemically stain cholinergic neurons in the neostriatum and nucleus basalis of Meynert in human brain. Cells in both regions were intensely stained as were nerve fibers. Comparable cells were stained in these same brain regions in the rat. This anti-human ChAT antibody will enable the further detailed characterization of cholinergic neurons in the human brain in both health and disease.

Animals↗
PubMed1985

A comparative study of choline acetyltransferase from normal and Alzheimer brain.

A comparative study was made of the enzyme choline acetyltransferase (ChAT) from normal and Alzheimer (senile dementia of the Alzheimer type) brain. The number of molecular weight and charge forms of the enzyme were determined in the caudate region of both brains. Efficient purification of active ChAT was achieved using immuno-affinity purification. It was shown that the purified enzyme was identical in both cases, exhibiting a single charge (apparent pI approximately 8.2) and a single molecular weight (mol. wt. = 68,000). The idea of a selective loss of one particular isoform to explain the reduced levels of ChAT observed in Alzheimer's disease can be ruled out.

Alzheimer Disease↗
PubMed1985

Immunoaffinity purification of human choline acetyltransferase: comparison of the brain and placental enzymes.

A rapid and efficient immunoaffinity purification procedure has been developed for human placental choline acetyltransferase (ChAT). Using this procedure, human placental ChAT was purified to homogeneity with high recovery of enzyme activity (50-60%). Purified ChAT was used to raise a monospecific anti-human ChAT polyclonal antibody in rabbits. A comparison of the physical properties of ChAT was made between the enzymes purified from human brain and human placenta. Only one form of the enzyme exists in either tissue, having identical molecular weights of 68,000 and a single apparent pI of 8.1. A more detailed comparison of the two enzymes using peptide mapping and epitope mapping indicates identity between the brain and placental enzymes.

Amino Acids↗
PubMed1984

Breakdown of gliadin peptides by intestinal brush borders from coeliac patients.

The 'missing peptidase' hypothesis to explain the aetiology of coeliac disease has never been satisfactorily resolved and recent reports suggest that coeliac brush borders may have depressed levels of specific peptidase enzymes. It has been inferred from these studies that the subsequent brush border digestion of gliadin peptides may therefore be defective. In this present study a sensitive fluorometric assay was used to measure the hydrolysis of a peptic-tryptic digest of gliadin by both normal and coeliac brush borders. The coeliac brush borders were as efficient as the normals in hydrolysing gliadin peptides and showed no depression of any specific peptidase activity.

Celiac Disease↗
PubMed1983

Vitamin status in patients on maintenance haemodialysis.

The vitamin status (vitamins A, E, C, Carotene, B1, B2 and B6) of 18 patients receiving maintenance haemodialysis was assessed. All patients were receiving vitamin B1, B2 and B6 supplements and the effect of stopping these supplements on subsequent vitamin status was further studied. Apart from vitamin A, which was significantly increased in all patients, the mean level of all other vitamins was similar to the control group. Despite these normal group means, individual patients could be identified with low or marginally low vitamin C and B2 levels. When the vitamin B complex supplements were stopped, vitamin B2 and B6 remained normal over the subsequent six months maintenance haemodialysis but there was deterioration in vitamin B2 status. Leucocyte vitamin C levels responded well to oral supplements of 400 mg vitamin C per day. This study suggests that vitamin C and B2 supplements are necessary in patients receiving maintenance haemodialysis, other vitamin supplements being unnecessary.

Avitaminosis↗
PubMed1982

Textual aspects of prosody in Swedish.

The present paper explores the textual function of intonation in indicating coherence and boundaries between successive utterances of speech. An informal listening test showed how such prosodic coupling can be used to mark coherence between sentences of a text unit. The coherence is expressed as a downdrift of F0 peaks and valleys characterizing the whole text unit. The boundary between two text units is signalled by terminating one and beginning another downdrift ramp. The characteristic features of the downdrift pattern seem to be (1) an adjustment of F0 values to the length of the text unit, and (2) an adaptation of the F0 of the beginning of a succeeding sentence to that of the later part of a preceding one in the same unit. Some preliminary implications of these results for speech planning are discussed.

Humans↗
PubMed1981

An accurate fluorometric method to measure the breakdown of gliadin and gliadin peptides.

A simple and accurate method is described to measure the breakdown of gliadin and gliadin peptides. It involves measuring the release of the predominant amino acids glutamine and glutamic acid using a fluorometric double enzyme assay and contains none of the problems normally associated with previously used techniques. The assay is highly accurate in that small concentrations of the free amino acids can be measured with no interference from the peptide bound amino acids. The assay system was used to study the breakdown of: whole gliadin, a peptic/tryptic digest of gliadin (PT gliadin), and a peptic/tryptic/chymotryptic digest of gliadin (PTC gliadin) using a rat intestinal brush border fraction. Both PT and PTC gliadin are hydrolysed at higher rates than is whole gliadin. Exhaustive hydrolysis shows that a brush border fraction can totally break down PT gliadin while an initial linear rate of breakdown is observed (up to 60 min).

Animals↗
PubMed1981

Vitamin status in treated patients with cystic fibrosis.

The water-soluble (B1, B2, B6, C, folic acid) and fat-soluble vitamin (A, carotene, E, and D) status of 36 patients with cystic fibrosis was assessed and compared with a control group of 21 age-matched normal children. Twenty-seven of the patients were receiving vitamin supplements (except folic acid and vitamin E) at the time of investigation. Vitamin B1, B2, and B6 status was adequate in all patients, and there was little evidence of folic acid deficiency. Vitamin C stores might not have been adequate in some of these patients, despite daily supplements with 50 mg of the vitamin. Steatorrhoea, often severe, was present in most of them. Serum carotene and vitamin E concentrations were low in over 90% of patients and were related to the severity of steatorrhoea. Vitamin A was low in over 40% of the patients despite daily vitamin supplements of 4000 IU and correlated with the serum retinol-binding protein level. Serum 25-OH cholecalciferol was low in some patients whether or not they were receiving a daily supplement of 400 IU vitamin D. In a short-term supplementation trial with water-miscible preparations of vitamin A and E in 14 patients, the serum levels of both vitamins responded well to 2 weeks of treatment with 50 mg vitamin E and 4000 IU vitamin A. Except for serum vitamin A, which was lowest in patients with the poorest clinical grading, the other vitamins were not influenced by the clinical grade of the patients.

Adolescent↗