Biomedical subjects

C Bourque

Publications and source records attributed to C Bourque.

7 recordsLinked to original sources

PubMed2003

Medium- versus long-chain triglycerides for 27 days increases fat oxidation and energy expenditure without resulting in changes in body composition in overweight women.

OBJECTIVE: To determine the effects of long-term consumption of medium chain (MCT) versus long chain triglycerides (LCT) on energy expenditure (EE), substrate oxidation and body composition. HYPOTHESIS: MCT consumption will not result in greater EE, substrate oxidation, and body weight loss compared with LCT consumption. RESEARCH METHODS AND PROCEDURES: Seventeen healthy obese women participated in this randomized, crossover inpatient trial. Meals were prepared and consumed on site for two periods of 27 days. Diets containing 40% of energy as fat, with treatment fat comprising 75% of the total fat, were designed to supply each subject with their individual weight-maintaining energy needs. The MCT diet contained 67% of treatment fat as MCT oil (49% octanoate, 50% decanoate) whereas the LCT diet contained exclusively beef tallow as treatment fat. Body composition was assessed by magnetic resonance imaging (MRI) on day 1 and 28 of each phase while energy expenditure was measured on day 2 and 27. RESULTS: Changes in total and subcutaneous adipose tissue volumes following consumption of MCT and LCT were not different (-0.61+/-0.38 l vs -0.54+/-0.48 l and -0.58+/-0.35 l vs -0.48+/-0.40 l, respectively). Average EE and fat oxidation were greater (P<0.05) during MCT than LCT consumption (0.95+/-0.019 vs 0.90+/-0.024 kcal/min, respectively, for EE and 0.080+/-0.0026 vs 0.075+/-0.0022 g/min, respectively for fat oxidation). DISCUSSION: These results show that long-term consumption of MCT enhances EE and fat oxidation in obese women, when compared to LCT consumption. The difference in body composition change between MCT and LCT consumption, although not statistically different, was consistent with differences predicted by the shifts in EE. It can be concluded that substitution of MCT for LCT in a targeted energy balance diet may prevent long-term weight gain via increased EE.

Adipose Tissue↗

PubMed1997

Specialized membrane domains for water transport in glial cells: high-resolution immunogold cytochemistry of aquaporin-4 in rat brain.

Membrane water transport is critically involved in brain volume homeostasis and in the pathogenesis of brain edema. The cDNA encoding aquaporin-4 (AQP4) water channel protein was recently isolated from rat brain. We used immunocytochemistry and high-resolution immunogold electron microscopy to identify the cells and membrane domains that mediate water flux through AQP4. The AQP4 protein is abundant in glial cells bordering the subarachnoidal space, ventricles, and blood vessels. AQP4 is also abundant in osmosensory areas, including the supraoptic nucleus and subfornical organ. Immunogold analysis demonstrated that AQP4 is restricted to glial membranes and to subpopulations of ependymal cells. AQP4 is particularly strongly expressed in glial membranes that are in direct contact with capillaries and pia. The highly polarized AQP4 expression indicates that these cells are equipped with specific membrane domains that are specialized for water transport, thereby mediating the flow of water between glial cells and the cavities filled with CSF and the intravascular space.

Animals↗

PubMed1985

NH2-terminal specificity and axonal localization of adrenocorticotropin binding sites in rat median eminence.

Adrenocorticotropin binding sites in the rat median eminence have been localized in vivo. These binding sites occur in the basalar zone, which is rich in axonal endings. Using competitive binding and quantitative light-microscope radioautography, we found that the median-eminence binding site, in contradistinction to the adrenal receptor, binds specifically the residue 4-10 region of the adrenocorticotropin molecule. Using quantitative electron-microscope radioautography and median-eminence deafferentation, we localized the binding sites to axon terminals in this region. In time-delayed uptake studies using light-microscope radioautography, we failed to observe concentration of radiolabel in neurons of the medial basal hypothalamus after the direct injection of radioiodinated adrenocorticotropin(1-24) into the median eminence.

Adrenal Glands↗

PubMed1982

An investigation of the mechanisms of action of 5-hydroxytryptamine in the suppression of ethanol intake.

The effect of blockage of 5-hydroxytryptamine and norepinephrine uptake on voluntary ethanol consumption in rats was investigated. It was demonstrated that attenuation of ethanol intake occurred only as a result of treatment with specific 5-hydroxytryptamine uptake inhibitors. These results suggested that increasing the availability of central 5-hydroxytryptamine may in some way interfere with the positive reinforcing properties of ethanol. The second phase was designed to determine whether the attenuation of ethanol intake following blockade of 5-hydroxytryptamine uptake may be due to increased post-synaptic activity. Ethanol-preferring animals were pretreated with methergoline, a post-synaptic receptor blocker, followed by treatment with zimelidine, a 5-hydroxytryptamine uptake inhibitor. The results indicate that treatment with methergoline did not alter the zimelidine-induced attenuation of ethanol intake. Based on these results it is suggested that blockade of 5-hydroxytryptamine uptake produces an attenuation of ethanol intake but not as a result of increased post-synaptic activity.

Alcohol Drinking↗

PubMed1980

Reduction of voluntary morphine consumption following treatment with zimelidine.

Male Wistar rats were presented with an everyday free choice between water and a morphine-sucrose solution. Following a 5-day baseline period animals were injected with either zimelidine (10 or 20 mg/kg, i.p.), a neuronal serotonin uptake inhibitor, or Ringer's solution (2 ml/kg, i.p.) for 5 consecutive days. Treatment with zimelidine was shown to significantly attenuate morphine drinking suggesting that an increased availability of serotonin may interfere with the positive reinforcing properties of morphine. The results are also discussed in terms of a possible interaction with brain norepinephrine. The possibility that the reinforcing effects of both morphine and ethanol are subserved by common mechanisms is suggested.

Animals↗

PubMed1977

Cholera-like diarrhea in Canada. Report of a case associated with enterotoxigenic Escherichia coli and a toxin-producing Aeromonas hydrophila.

A 67-year-old Indian patient was admitted with an acute cholera-like illness. Toxigenic Escherichia coli producing both heat-stable and heat-labile enterotoxins grew from cultures of feces. In addition, an Aeromonas hydrophila producing a cytotoxic toxin was also isolated from this patient's feces. The unusual severity of this patient's illness may have resulted from coinfection with these two toxigenic organisms, although any role of the toxin produced by a hydrophila is speculative.

Aeromonas↗

PubMedDate not supplied

[Acute sarcoidosis].

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Acute Disease↗