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Biomedical subjects

M Griffiths

Publications and source records attributed to M Griffiths.

At least 37 records · Page 2Linked to original sources
PubMed1994

Implicit memory.

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Anesthesia, General↗
PubMed1994

Warts in butchers.

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Disease Susceptibility↗
PubMed1994

Neocortical cholinergic activities differentiate Lewy body dementia from classical Alzheimer's disease.

Activity of the enzyme which synthesizes acetylcholine, choline acetyltransferase, was estimated in the neocortex of three series of control and demented cases. Clinically demented cases were divided into those with the classical neuropathological features of Alzheimer's disease (numerous neocortical plaques and tangles) and those with Lewy bodies in the brain stem and cortex (together with plaques and variable neurofibrillary pathology). In the Lewy body cases neocortical choline acetyltransferase was consistently lower than in the classical Alzheimer-type cases. Two of the Lewy body cases with extremely low cholinergic activity were responders in therapeutic trials of the cholinesterase inhibitor, tacrine, and the combined data suggest that cholinergic therapy may be particularly relevant to patients with Lewy body type dementia.

Alzheimer Disease↗
PubMed1994

Cardiac hypertrophy alters myocardial response to ischaemia and reperfusion in vivo.

The impact of cardiac hypertrophy on myocardial biochemical and physiological responses to ischaemia-reperfusion (I-R) was investigated in vivo. Hypertrophy was produced by aortic constriction (PH) or swimming training (TH). Open-chest rat hearts in PH, TH and a sedentary control group (SC) were subjected: (1) to ischaemia, by surgical occlusion of the main descending branch of the left coronary artery for 30 min; (2) to I-R, by releasing the occluded blood vessel for 15 min; or (3) to a sham operation. Ischaemia per se had little effect on heart oxidative and antioxidant status, or lipid peroxidation. However, I-R significantly decreased glutathione (GSH) content, increased glutathione disulfide (GSSG) content, and reduced GSH/GSSG ratio in the SC hearts. These alterations were associated with decreased activities of GSH peroxidase and GSSG reductase, and an increase in lipid peroxidation. Myocardial ATP, total adenine nucleotide content and energy charge in SC were significantly decreased after ischaemia, whereas levels of purine nucleotide derivatives, particularly adenosine, were elevated. No significant alteration of GSH status of adenine nucleotide metabolism occurred after ischaemia or I-R in hypertrophied hearts. In both PH and TH, glutathione content was significantly higher than in SC, whereas activities of GSH peroxidase and GSSG reductases were lower. TH rats maintained a higher heart rate (HR), peak systolic pressure, and energy charge during I-R. These data indicate that hypertrophied but well-functioned hearts may be more resistant to I-R induced disturbances of myocardial oxidative and antioxidant functions.

Adenine Nucleotides↗
PubMed1994

IgG2 associated hypergammaglobulinaemia in some Nigerians with HIV infection.

Concentrations of immunoglobulins (IgA, IgG and IgM) were measured in Nigerians with (HIV) infection. Considerable elevations up to two-fold the reference values were observed for IgG and IgM in the patient group as a whole but elevations in IgA concentration were least marked albeit significantly different from the healthy subjects. Elevation of a particular isotype was not always concomitant with elevation of the other major classes in the same patient. Overall, these elevations were observed in both symptomatic and asymptomatic infected subjects. Further analysis of IgG hyperglobulinemia showed that increases in this major class may be due to increased IgG2 subclass concentrations. It is suggested that elevation of IgG2 subclass in Nigerians with HIV infection and not IgG1 or IgG3 may be due to genetic and environmental factors rather than variation in the strain of the virus.

Case-Control Studies↗
PubMed1993

The phylogeny of the genus Yersinia based on 16S rDNA sequences.

The inter- and intrageneric relationships of the genus Yersinia were investigated by sequence analysis of the 16S rRNA gene. A stretch of approximately 1450 nucleotides was sequenced from representatives of ten of the eleven validly described species. Phylogenetic analysis revealed that yersinae form a coherent cluster within the gamma subgroup of Proteobacteria. The intrageneric relationship was characterized by five sublines with Y. enterocolitica, Y. rohdei, and Y. ruckeri forming separate sublines each represented by a single species. A separate subline was formed by Y. pestis, Y pseudotuberculosis and Y. kristensenii, while Y. mollaretii, Y. intermedia, Y. bercovieri, Y. aldovae, and Y. kristensenii formed a fifth subline. The phylogenetic distinctness of the yersiniae sublines is compared to published phenotypic properties and results of DNA-DNA similarity studies.

Base Sequence↗
PubMed1993

Isolation, partial characterisation, and amino acid sequence of alpha-lactalbumin from platypus (Ornithorhynchus anatinus) milk.

alpha-Lactalbumin was isolated from the whey fraction of platypus (Ornithorhynchus anatinus) milk by successive ion-exchange, hydrophobic interaction and gel-permeation chromatography. The purified protein modified the action of partially-purified galactosyltransferase from platypus milk to promote the synthesis of lactose, but had very little modifier effect on bovine galactosyltransferase. Platypus alpha-lactalbumin has 126 amino-acid residues (molecular mass about 14.3 kDa), including a three-residue insertion not found in other alpha-lactalbumins or c-type lysozymes. It appears to have two sites of post-translational modification, of which at least one is N-glycosylated, to give an apparent molecular mass of 23 kDa on SDS-PAGE. The platypus sequence shows a high degree of positional identity (41-48%) with the alpha-lactalbumins of other species. Although it has no lysozyme activity, platypus alpha-lactalbumin is more similar to mammalian lysozymes than is any eutherian or marsupial alpha-lactalbumin, suggesting that this monotreme protein has evolved more slowly than other alpha-lactalbumins.

Amino Acid Sequence↗