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Hugh Morgan

Publications and source records attributed to Hugh Morgan.

7 recordsLinked to original sources
PubMed2003

Epigenetic asymmetry in the mammalian zygote and early embryo: relationship to lineage commitment?

Epigenetic asymmetry between parental genomes and embryonic lineages exists at the earliest stages of mammalian development. The maternal genome in the zygote is highly methylated in both its DNA and its histones and most imprinted genes have maternal germline methylation imprints. The paternal genome is rapidly remodelled with protamine removal, addition of acetylated histones, and rapid demethylation of DNA before replication. A minority of imprinted genes have paternal germline methylation imprints. Methylation and chromatin reprogramming continues during cleavage divisions, but at the blastocyst stage lineage commitment to inner cell mass (ICM) or trophectoderm (TE) fate is accompanied by a dramatic increase in DNA and histone methylation, predominantly in the ICM. This may set up major epigenetic differences between embryonic and extraembryonic tissues, including in X-chromosome inactivation and perhaps imprinting. Maintaining epigenetic asymmetry appears important for development as asymmetry is lost in cloned embryos, most of which have developmental defects, and in particular an imbalance between extraembryonic and embryonic tissue development.

Animals↗
PubMed2003

Fits, faints and funny turns. Could it be a mental disorder?

BACKGROUND: Patients who present to primary care with symptoms of fainting and dizziness, for which there is no adequate physical explanation, are frequently suffering from an undiagnosed psychiatric disorder. OBJECTIVE: This article aims to improve the recognition of common mental disorders presenting as 'fits, faints and funny turns' (FFFTs) and to encourage general practitioners to view these disorders as a positive diagnosis in need of treatment. DISCUSSION: Psychiatric disorders, particularly panic attacks and depression, are common in the setting of FFFTs and should be a positive diagnosis rather than a diagnosis of exclusion. A detailed description of the episode, with corroborating information from a witness if possible, and psychiatric rating scales can assist in this process. Identifying a physical cause for the episode does not exclude a psychiatric diagnosis and vice versa. Specific psychological and pharmacological therapies are effective for anxiety and depression.

Adult↗
PubMed2002

Clostridium thermobutyricum: growth studies and stimulation of butyrate formation by acetate supplementation.

Clostridium thermobutyricum produces butyrate as the main fermentation product from glucose, and from yeast extract, which is required for substantial growth. After sequential transfer in the presence of increasing butyrate concentrations, strain JW 171 K grew in the presence of up to 350 mM butyrate either at pH 5.5 or at pH 8.0 and at 40 degrees C as well as at 60 degrees C. This result indicated that butyrate-dependent growth inhibition was independent from the concentration of undissociated butyric acid. Increased butyrate concentration decreased the level of tolerated glucose from above 15% to below 10%. At 0.05 and 2.0% (wt/vol) yeast extract, the Y(Glucose) was 30 and 55 g dry weight cells per mole glucose, respectively. Y(ATP) values between 18 and 21 g weight cells per mole ATP, obtained after growth in the presence of 2% yeast extract, indicate that the butyrate fermentation under thermophilic growth conditions is as energy efficient as it is under mesophilic conditions. Externally added acetate stimulated the production of butyrate. Supplemented 14C-acetate was converted to butyrate, resulting in the formation of 44% labeled butyrate (i.e. formed from 14C-acetate) and 56% unlabeled butyrate (formed from glucose and yeast extract). Continuous removal of H2 in batch cultures led to a shift in the fermentation products from more butyrate to the more oxidized and more energy yielding acetate.

Acetic Acid↗