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Biomedical subjects

K Wynne

Publications and source records attributed to K Wynne.

9 recordsLinked to original sources
PubMed2006

Oxyntomodulin increases energy expenditure in addition to decreasing energy intake in overweight and obese humans: a randomised controlled trial.

BACKGROUND: Oxyntomodulin has recently been found to decrease body-weight in obese humans and may be a potential anti-obesity therapy. OBJECTIVE: To determine whether oxyntomodulin alters energy expenditure, in addition to reducing energy intake, in 'free-living' overweight and obese volunteers. DESIGN: Randomized double-blind controlled cross-over trial. SETTING: Community and hospital-based. PARTICIPANTS: Fifteen healthy overweight and obese men and women (age: 23-49 years, BMI: 25.1-39.0 kg/m(2)). All volunteers completed the study protocol. INTERVENTIONS: Four-day subcutaneous self-administration of pre-prandial oxyntomodulin, three times daily. Participants were advised to maintain their normal dietary and exercise regimen. MEASUREMENTS: (1) Energy expenditure, measured by indirect calorimetry and combined heart rate and movement monitoring; (2) energy intake, measured during a study meal. RESULTS: Oxyntomodulin administration reduced energy intake at the study meal by 128+/-29 kcal (P=0.0006) or 17.3+/-5.5% (P=0.0071), with no change in meal palatability. Oxyntomodulin did not alter resting energy expenditure; but increased activity-related energy expenditure by 143+/-109 kcal/day or 26.2+/-9.9% (P=0.0221); total energy expenditure by 9.4+/-4.8% (P=0.0454) and physical activity level by 9.5+/-4.6% (P=0.0495). A reduction in body weight of 0.5+/-0.2% was observed during the oxyntomodulin administration period (P=0.0232). CONCLUSION: Oxyntomodulin increases energy expenditure while reducing energy intake resulting in negative energy balance. This data supports the role of oxyntomodulin as a potential anti-obesity therapy.

Adult↗
PubMed2000

Noncausal time response in frustrated total internal reflection?

Tunneling of photons in frustrated total internal reflection has been studied in the time domain with single-cycle femtosecond pulses. It is seen that both the phase and energy of the pulse travel faster than the speed of light in vacuum. Theoretical analysis of the experiments shows that the time-response function for electromagnetic waves propagating in the air gap is noncausal. However, it is found that superluminal signal propagation is not possible in this case because of the inevitable diffractive spreading of the signal beam.

Journal Article↗
PubMed1999

Dissociable deficits in the decision-making cognition of chronic amphetamine abusers, opiate abusers, patients with focal damage to prefrontal cortex, and tryptophan-depleted normal volunteers: evidence for monoaminergic mechanisms.

We used a novel computerized decision-making task to compare the decision-making behavior of chronic amphetamine abusers, chronic opiate abusers, and patients with focal lesions of orbital prefrontal cortex (PFC) or dorsolateral/medial PFC. We also assessed the effects of reducing central 5-hydroxytryptamine (5-HT) activity using a tryptophan-depleting amino acid drink in normal volunteers. Chronic amphetamine abusers showed suboptimal decisions (correlated with years of abuse), and deliberated for significantly longer before making their choices. The opiate abusers exhibited only the second of these behavioral changes. Importantly, both sub-optimal choices and increased deliberation times were evident in the patients with damage to orbitofrontal PFC but not other sectors of PFC. Qualitatively, the performance of the subjects with lowered plasma tryptophan was similar to that associated with amphetamine abuse, consistent with recent reports of depleted 5-HT in the orbital regions of PFC of methamphetamine abusers. Overall, these data suggest that chronic amphetamine abusers show similar decision-making deficits to those seen after focal damage to orbitofrontal PFC. These deficits may reflect altered neuromodulation of the orbitofrontal PFC and interconnected limbic-striatal systems by both the ascending 5-HT and mesocortical dopamine (DA) projections.

Adult↗
PubMed1999

Macroamylasaemia--a prognostic marker in a syndrome of malabsorption and complete villous atrophy? An uncommon clinical condition.

We report a rare case of chronic persistent hyperamylasaemia secondary to macroamylasaemia in association with coeliac disease in a 56-year-old woman. Her symptoms, including macroamylasaemia, ebbed away following commencement of a gluten free diet. Only four cases of a similar nature have been described in the literature. The differential diagnosis of macroamylasaemia should include coeliac disease, and an awareness of this association might obviate a variety of unnecessary diagnostic investigations.

Amylases↗
PubMed1990

A comparison of teicoplanin vs. cephradine and metronidazole in surgical prophylaxis: an interim analysis.

The preliminary results of a trial to examine and compare the safety, tolerability and efficacy of a single dose of teicoplanin with three doses of cephradine combined with metronidazole are presented in a series of 113 patients undergoing elective vascular surgery. There were no obvious differences in the infection rates and sepsis indicators in either group. Neither drug regimen produced any evidence of renal or hepatic damage, though the levels of three hepatocellular enzymes, aspartate aminotransferase (AST), alanine aminotransferase (ALT) and gamma-glutamyl-transferase (GGT), were seen to be transiently elevated, peaking 7 days post-operatively. The trial continues.

Administration, Rectal↗
PubMed1982

Effects of 2-hydroxyoestradiol-17 beta on plasma luteinizing hormone, follicle-stimulating hormone and prolactin, and nuclear translocation of pituitary oestrogen receptors in ovariectomized ewes.

The ability of oestradiol-17 beta (OE2) and 2-hydroxyoestradiol (2OH-OE2) to translocate pituitary oestrogen receptors to the nuclear compartment and to affect plasma concentrations of LH, FSH and prolactin was studied in ovariectomized ewes. Mean (+/- S.E.M.) nuclear oestrogen receptor levels (% of total pituitary oestrogen receptors) after intracarotid injections of 1.25 micrograms OE2, 400 micrograms 2OH-OE2 or vehicle were 8.7 +/- 2.3, 16.9 +/- 3.2 and 0.8 +/- 0.1% respectively. Whereas 1.25 or 12.5 micrograms OE2 significantly lowered plasma LH and FSH, 400 micrograms 2OH-OE2 did not affect plasma LH or FSH levels. Injection of 4000 micrograms 2OH-OE2 however, significantly affected plasma LH and FSH. Plasma prolactin levels were not significantly affected by the treatments. These data indicate a discrepancy between oestrogen receptor occupancy and effects on gonadotrophin and prolactin secretion after injection of catechol oestrogen.

Animals↗
PubMed1978

19-Nor deoxycorticosterone (19-nor DOC): mineralocorticoid receptor affinity higher than aldosterone, electrolyte activity lower.

By screening urine extracts from rats with adrenal regeneration hypertension, Gomez-Sanchez et al. found a steroid, subsequently identified as 19-nor DOC, with high affinity for tritiated aldosterone (3HA) binding sites in rat kidney cytosol. We here report studies on the affinity of authentic 19-nor DOC for mineralocorticoid receptors, its binding in plasma and its activity in the rat urinary mineralocorticoid assay. When kidney slices from adrenalectomized rats were incubated in protein-free buffer with 3HA, 19-nor DOC consistently competed better (approximately 140%) for 3HA binding sites than did equivalent concentrations of non-radioactive aldosterone. Under identical conditions, save for the inclusion of 20% adrenalectomized rat plasma in the incubation medium, 19-nor DOC shows only approximately 40% the potency of aldosterone in displacing 3HA. Determination of renal binding of 3HA after injection of 3HA +/- aldosterone +/- 19-nor DOC in vivo similarly shows 19-nor DOC to be approximately one third as potent a competitor for 3HA binding sites as aldosterone. In the rat urinary bioassay, 19-nor DOC shows no antagonist activity when injected with aldosterone; in the absence of aldosterone, 19-nor DOC acts as a mineralocorticoid agonist, with an apparent potency 10-30% that of aldosterone. Conclusions of the study are therefore (i) at a molecular level, 19-nor DOC has a higher affinity than aldosterone for mineralocorticoid receptors, (ii) in vivo, its potency in terms of receptor occupancy is markedly lower than that of aldosterone, due to higher levels of plasma binding, (iii) in effector terms, 19-nor DOC is a full agonist without antagonist activity.

Aldosterone↗