bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of the Modulatory Influence of Maize and Olive Oils and Butter on Metabolic Responses to Endotoxin in Rats
Authors: Besler H. T. , Grimble R. F. 
Published: August 2015

1. n-3 polyunsaturated fatty acids decrease responses to cytokines and inflammatory agents. The present study examines how different intakes of n-6 and n-9 fatty acids influence the metabolic response to endotoxin in Wistar rats.
2. Weanling male rats were, for 4 weeks, fed diets containing 50, 100 or 200 g/kg fat in the form of maize oil (rich in linoleic acid), butter (poor in linoleic acid, rich in oleic acid) or olive oil (adequate in linoleic acid, rich in oleic acid) or standard laboratory chow. All butter and olive oil diets included 10 g/kg maize oil, in total fat, to avoid essential fatty acid deficiency.
3. Rats subsequently received 800 μg/kg Escherichia coli endotoxin or sterile saline subcutaneously. Twenty-four hours after injection, the rate of tissue protein synthesis was measured in liver, lung, kidney, tibialis muscle and spleen by the ‘flooding dose’ method. Protein and zinc concentrations were assayed in all tissues and serum albumin and caeruloplasmin measured.
4. In animals fed chow, protein synthetic rate increased by 18%, 29% and 27% in liver, lung and kidney respectively. Tissue zinc concentrations increased by 33% in kidney, and tissue protein increased by 17%, 23% and 17% in liver, lung and kidney respectively. Serum caeruloplasmin increased by 60% and albumin concentration fell by 14%.
5. In animals consuming the 50 g/kg maize oil diet, protein synthetic rate increased by 56%, 36% and 34% in liver, lung and kidney respectively. Tissue zinc concentration increased by 14%, 15% and 17% in the three tissues respectively, and tissue protein concentration increased by 7%, 9% and 51% respectively. Serum caeruloplasmin increased by 172% and albumin concentrations fell by 22%.
6. No change in any parameter occurred in response to endotoxin in rats given diets containing fat predominantly as butter (50 and 100 g/kg), or olive oil (50, 100 and 200 g/kg).
7. In animals fed maize oil diets, responses increased in magnitude in parallel with dietary intake.
8. Responses in rats fed fat (200 g/kg) predominantly as butter were similar to those seen when diets contained 50 g/kg fat as maize oil.
9. The data suggest that the metabolic response to endotoxin is enhanced by n-6 and suppressed by n-9 unsaturated fatty acids. The modulatory influence of fats on responses to inflammatory agents may depend on the relative proportions of these substances.
Effect of Head-Down Tilt on Cardiovascular Control in Healthy Subjects: A Spectral Analytic Approach
Authors: Weise F. , London G. M. , Guerin A. P. , Pannier B. M. , Elghozi J.-L. 
Published: August 2015

1. The purpose of this investigation was to determine non-invasively the changes in autonomic cardiovascular control observed in normal subjects submitted to acute cardiopulmonary blood volume expansion by 100° head-down tilt. The effect of head-down tilt on finger blood pressure and heart rate fluctuations was studied by means of power spectral analysis in 12 healthy men.
2. Amplitude spectra of heart rate and blood pressure rhythmicity were estimated at the low-frequency (60–140 mHz, 10-s rhythm) and high-frequency (area under the curve at mean respiration rate ± 50 mHz) component. Transfer gain and phase were calculated between systolic blood pressure and heart rate. Forearm vascular resistance was estimated to validate the head-down procedure.
3. Forearm vascular resistance decreased significantly from 19.82 (16.34–26.46) mmHg ml−1 min 100 ml to 18.05 (13.69–22.88) mmHg ml−1 min 100 ml (P &lt; 0.01) during head-down tilt (values are medians and 25 and 75 percentiles). The overall variability (total area under the curve of the spectrum from 20 to 500 mHz) of blood pressure and heart rate time series was consistently reduced with head-down tilt.
4. The spectral pattern of systolic blood pressure showed a diminution of the absolute and relative low-frequency component during head-down tilt: absolute log-transformed values, 2.86 (2.80–2.94) mmHg/Hz1/2 versus 2.77 (2.72–2.82) mmHg/Hz1/2 (P &lt; 0.05); relative values, 35% (32–37%) versus 32% (29–32%) (P &lt; 0.05). In heart rate spectra only the absolute low-frequency component decreased. There was no change in the high-frequency component in all time series or in the transfer gain and phase during head-down tilt.
5. It is concluded that head-down tilt is a simple manoeuvre to diminish the 10-s rhythm in systolic blood pressure, which may reflect the reduced sympathetic vasomotor control after cardiopulmonary baroreceptor loading.
Acute Effect of Parathyroid Hormone on Urine Concentration in the Rat
Authors: Carney S. L. , Gillies A. H. B. 
Published: August 2015

1. It has been demonstrated that parathyroid hormone can increase adenylate cyclase activity in the rat papilla, produce a small antidiuretic effect and in vitro can interfere with the action of arginine vasopressin on water transport. Clearance studies were performed in the anaesthetized water diuretic thyroparathyroidectomized rat to evaluate further the effect of parathyroid hormone on urine concentration in the presence and absence of arginine vasopressin.
2. A maximal phosphaturic concentration of rat parathyroid hormone (2 μg/kg) reduced urine flow from 125 ± 7 to 81 ± 9 μl/min within 10 min (P &lt; 0.01). Addition of a maximal antidiuretic concentration of arginine vasopressin (100 ng/kg) produced a delayed and diminished antidiuretic response when compared with a group of rats not pretreated with parathyroid hormone (47 ± 5 compared with 27 ± 5 μl/min; P &lt; 0.01). However, a supramaximal arginine vasopressin concentration (1000 ng/kg) produced a maximal antidiuretic effect in the presence of parathyroid hormone.
3. To evaluate further the inhibitory effect of parathyroid hormone on arginine vasopressin-induced anti-diuresis, parathyroid hormone (2 μg/kg) was administered to one group of rats and a minimally effective arginine vasopressin concentration (7.5 ng/kg) to another group, which produced a similar antidiuretic effect. However, the subsequent effect of a maximal antidiuretic arginine vasopressin concentration (100 ng/kg) was again significantly blunted in the group pretreated with parathyroid hormone.
4. Parathyroid hormone produced only a small increase in mean plasma calcium concentration, and glomerular filtration rate was not altered by either hormone.
5. These results demonstrate that high physiological concentrations of parathyroid hormone do have a significant antidiuretic effect and can interfere with the action of arginine vasopressin. This suggests that parathyroid hormone may act as a partial agonist to arginine vasopressin in the collecting system.
Effects of Dietary Polyunsaturated Fatty Acids on Small Intestinal Secretory and Absorptive Function: Studies in Rat Jejunum In Vitro
Authors: Lindley K. J. , Muller D. P. R. , Milla P. J. 
Published: August 2015

1. Recent initiatives which advocate an increase in dietary polyunsaturated fat intake have led to the study of the effects of this upon gastrointestinal function.
2. Weanling rats were for 21 weeks fed diets containing 10% fat that were either high or low in polyunsaturated fats. Jejunal function was studied in vitro in an Ussing chamber.
3. Basal intestinal short-circuit was similar in both groups.
4. A decreased EC50 for the non-neural electrogenic secretory responses to acetylcholine, bethanecol and isobutylmethylxanthine was apparent in the jejuna of rats fed a diet high in polyunsaturated fatty acids.
5. Submaximal electrogenic galactose absorption was increased in the rats fed a diet high in polyunsaturated fatty acids.
6. Changing the composition of dietary lipid resulted in a change in the fatty composition of the apical enterocyte membrane.
7. Diets high in polyunsaturated fatty acids may be both prosecretory and proabsorptive in the small intestine.
A Map of the Heart: Gap Junctions, Connexin Diversity and Retroviral Studies of Conduction Myocyte Lineage
Authors: Gourdie Robert G. 
Published: August 2015

1. The heartbeat is co-ordinated by organized propagation of electrical excitation through cardiac muscle. Intercellular conduction and propagation of the cardiac action potential is dependent on electrical connections between myocytes, termed gap junctions.
2. In the last few years, our conception of the structure and function of cardiac gap junctions has been revised substantially. It seems that these structures show unexpected levels of specialization within the myocardium and they can no longer be viewed simply as passive conduits for the regulated movement of electrical current between heart muscle cells.
3. In this article, some of the contributions to this field by the author and his collaborators are summarized. Studies using confocal microscopy and digital imaging techniques to characterize the three-dimensional organization of electrical contacts between myocytes in the mature and developing heart are described, data on the unique expression and spatial distribution patterns of gap-junctional subunit proteins (connexins) are given, and finally the author's current work on the differentiation of cardiac conduction tissues, and how this work arose from studies of gap junctions in the heart, is introduced.
Circulating Antibodies to Cardiac Protein—Acetaldehyde Adducts in Alcoholic Heart Muscle Disease
Authors: Harcombe A. A. , Ramsay L. , Kenna J. G. , Koskinas J. , Why H. J. F. , Richardson P. J. , Weissberg P. L. , Alexander G. J. M. 
Published: August 2015

1. Serum samples from patients with alcoholic heart muscle disease and from control subjects with and without heart disease who did not drink to excess were screened by Western immunoblotting for antibodies to acetaldehyde-modified cardiac cytosolic proteins.
2. Two of the 64 control samples (from subjects with and without heart disease who were not drinking and from subjects with alcoholic liver disease) had detectable (IgG) antibody to acetaldehyde-modified cardiac proteins.
3. By contrast, 7 of 21 (33%) patients with alcoholic heart muscle disease had antibodies against cyanoborohydride-stabilized, acetaldehyde-modified human cardiac cytosolic protein antigens (P &lt; 0.001).
4. Antibodies were of IgG class in six patients and IgA class in five. The molecular sizes of the protein antigens observed ranged from 58 to 120 kDa.
5. These results suggest that a proportion of patients with alcoholic heart muscle disease develop immunogenic cardiac protein—acetaldehyde adducts. The presence of antibodies to these adducts may be a marker for the diagnosis of this heart disease, or possibly for its pathogenesis.
Impaired Platelet Aggregation after Cardiopulmonary Bypass in Man: Enhancement of Collagen-Induced Aggregation in whole Blood and Plasma by Adrenaline Ex Vivo
Authors: Menys Valentine C. , Belcher Philip R. , Noble Mark I. M. , Drossos George E. , Pillai Ravi , Westaby Steve 
Published: August 2015

1. We tested the effect of intravenous adrenaline at 0.55–1.10 nmol min−1 kg−1 (for 3–8 min, at 7–10 min post bypass; n = 7) on both microaggregation in hirudinized whole blood, using platelet counting, and macroaggregation in platelet-rich plasma, using optical aggregometry. Control (n = 12) blood samples were taken before and at 10 and 20 min after bypass.
2. Post-bypass plasma adrenaline levels (nmol/l) increased slightly in controls (1.0 versus 0.7 at 10 min, medians; P = 0.05) and markedly with adrenaline infusion (36 versus 0.5 before infusion, P = 0.02). Microaggregation (percentage decrease in single platelets) in stirred blood, reflecting largely ADP-dependent ‘spontaneous’ aggregation, was not influenced by adrenaline infusion. In contrast, collagen (0.2 μg/ml)-induced microaggregation in blood was enhanced by adrenaline (92% versus 41%, P = 0.02), with no change in controls (60% versus 53%, P = 0.61).
3. In controls, collagen (0.6 μg/ml)-induced macroaggregation in platelet-rich plasma (extent of increase in light transmission, cm) was impaired at 10 min post bypass (5.3 versus 12.1 before bypass, P = 0.01), but was enhanced by adrenaline (7.0 versus 3.6 before infusion, P = 0.02). Platelet counts (×109/1) were decreased postbypass (155 versus 220, P = 0.02) and were not influenced by adrenaline infusion (167, P = 0.93).
4. In conclusion, following bypass and at normocalcaemia, adrenaline enhances collagen-induced aggregation in both plasma and whole blood ex vivo, independently of any change in platelet counts, but has no effect on stirring-induced ‘spontaneous’ aggregation in blood.
Human Erythrocyte Membrane Fluidity and Calcium Pump Activity in Primary Combined Hyperlipidaemia
Authors: Muzulu S. I. , Bing R. F. , Norman R. I. 
Published: August 2015

1. Human erythrocyte membrane cholesterol, fluidity and basal and calmodulin-stimulated calcium pump (Ca2+-Mg2+-ATPase) activities were compared in 24 patients with primary combined hyperlipidaemia and 20 age-matched normolipidaemic control subjects.
2. There was no correlation between serum and membrane cholesterol. Despite the differences in serum cholesterol levels between the two groups, membrane cholesterol levels were similar.
3. 1,6-Diphenyl-1,3,5-hexatriene anisotropy was lower in the hyperlipidaemic group, suggesting increased fluidity in the hydrocarbon core of the phospholipid membrane bilayer.
4. Basal calcium pump activity was lower in the hyperlipidaemic group with increased membrane fluidity.
5. These results suggest that membrane adaptive mechanisms can maintain membrane cholesterol within a narrow range, that serum triacylglycerol is more important than serum cholesterol in determining membrane fluidity and that increased membrane fluidity reduces basal calcium pump activity.
Combined Intestinal Trefoil Factor and Epidermal Growth Factor is Prophylactic against Indomethacin-Induced Gastric Damage in the Rat
Authors: Chinery Rebecca , Playford Raymond J. 
Published: August 2015

1. The availability of recombinant epidermal growth factor provides a potentially exciting development for the treatment of gastrointestinal ulceration. However, because of its potent mitogenic activity, there is a need for strategies which reduce the dose required. Intestinal trefoil factor stimulates mucosal healing without increasing proliferation. Studies were undertaken to examine the biological effects of rat intestinal trefoil factor and/or human epidermal growth factor upon gastrointestinal epithelial cell functions pertinent to mucosal protection, using two wounding models.
2. The study of epithelial restitution in vitro demonstrated a marked synergistic effect on the rate of migration of the wound edge when intestinal trefoil factor was used in combination with epidermal growth factor. There was no increased cellular proliferation due to the addition of intestinal trefoil factor to the cells when given alone, or to the stimulatory effect of cells treated with epidermal growth factor. In the rat model of gastric ulceration, the presence of both epidermal growth factor and intestinal trefoil factor protected against the development of indomethacin-induced gastric lesions.
3. We conclude that combination therapy of epidermal growth factor with intestinal trefoil factor could provide a more potent, safer approach to the treatment of human gastrointestinal ulceration.
Relationship between Plasma Volume, Carotid Baroreceptor Sensitivity and Orthostatic Tolerance
Authors: El-Sayed H. , Hainsworth R. 
Published: August 2015

1. Studies were carried out on 43 otherwise healthy patients referred for investigation for attacks of syncope of unknown cause and on six healthy volunteers.
2. Plasma volume was determined by Evans Blue dye dilution and blood volume was estimated using haematocrit. Carotid baroreceptor sensitivity was determined from the changes in pulse interval in response to subatmospheric pressures applied to the neck overlying the carotid sinuses, and orthostatic tolerance was assessed as the time to presyncope in a test of head-up tilt, followed by the addition of graded lower body suction.
3. Eight patients and one volunteer fainted during head-up tilt alone, 23 patients and two volunteers fainted during tilt with lower body suction at −20 mmHg and 12 patients and three volunteers either fainted during suction at −40 mmHg or tolerated the entire procedure.
4. Although plasma and blood volumes were higher in males than females, the values normalized for either body weight or for calculated lean body mass were not different between male and female patients and asymptomatic volunteers. The subjects showing the greatest resistance to syncope were found to have significantly larger plasma and blood volumes (P &lt; 0.0001) and significantly smaller baroreceptor sensitivities (P &lt; 0.0002) than those who fainted earlier.
5. There was a highly significant positive correlation in all subjects between orthostatic tolerance (time to onset of syncope) and plasma and blood volumes (r = 0.60, P &lt; 0.0001; r = 0.53, P &lt; 0.0002), and highly significant negative correlations between time to syncope and baroreceptor sensitivity (r = −0.61, P &lt; 0.0001) and between baroreceptor sensitivity and plasma and blood volumes (r = −0.54, P &lt; 0.0001; r = −0.31, P &lt; 0.03).
6. These results show that tolerance to orthostatic stress is favoured by large plasma and blood volumes and a low sensitivity of the carotid baroreceptor—heart rate reflex.
Demonstration of Hypomethylation of Proteins in the Brain of Pigs (but Not in Rats) Associated with Chronic Vitamin B12 Inactivation
Authors: McKeever M. , Molloy A. , Young P. , Kennedy S. , Kennedy D. G. , Scott J. M. , Weir D. G. 
Published: August 2015

1. Pigs treated with nitrous oxide for periods of 1, 2 and 4 months demonstrated markedly reduced levels of methionine synthase and concomitant reduction in the ratio of S-adenosylmethionine to S-adenosylhomocysteine, the methylation ratio, at all time intervals.
2. Both ‘O’ and ‘N’ methylations were significantly reduced in pigs after 4 months in nitrous oxide but not after shorter periods.
3. Hypomethylation correlated with the development of clinical ataxia, but was absent when the pigs were clinically normal. It also only occurred when the S-adenosylmethionine level fell.
4. Rats maintained in nitrous oxide for 4 months showed a marked reduction of methionine synthase but no reduction in the methylation ratio or in brain hypomethylation. None of the rats became clinically ataxic.
5. Using an exogenous protein as a methyl group acceptor, it was demonstrated in an in vitro assay that the methyltransferase enzymes responsible for brain ‘O’ and ‘N’ methylation were not affected per se by nitrous oxide treatment.
6. It is concluded that reduction of the methylation ratio in the brain of pigs as a consequence of methionine synthase inhibition leads to brain hypomethylation. This hypomethylation could affect critical components of nerve tissue, inducing the vacuolar myelopathic changes seen in the spinal cord of these animals, which mimic those of subacute combined degeneration in man.
n-Butyrate Mediation of Ganglioside Expression of Human and Murine Cancer Cells Demonstrates Relative Cell Specificity
Authors: Berenson Charles S. , Patterson Melissa A. , Miqdadi Jehad A. , Lance Peter 
Published: August 2015

1. n-Butyrate, a short chain fatty acid produced by colonic fermentation, induces differentiation in human neoplastic cell lines, and reduces expression in vitro of a sialyltransferase that glycosylates N-linked glycoproteins in hepatoblastoma cells. Gangliosides are amphipathic, sialylated glycosphingolipids that undergo profound changes in many transformed cells and may protect neoplastic cells from host immune surveillance. Colonic mucosal cells are exposed to luminal short-chain fatty acid concentrations of up to 80 mmol/l, and there is some evidence that short-chain fatty acids may alter ganglioside expression in colon cancer cells.
2. Because of the importance of gangliosides in cancer pathogenesis, we investigated the effects of n-butyrate on ganglioside expression of colonic (human and murine) and non-colonic cancer cells.
3. Three separate colon cancer cell lines (LS174T, T84 and MCA-38), when butyrate treated, demonstrated striking amplification of specific individual gangliosides. However, the total lipid-bound sialic acid content of gangliosides of butyrate-treated LS174T cells diminished. In contrast to earlier reports, n-butyrate did not mediate expression of all gangliosides and specifically did not mediate expression of GM3. This effect persisted even after removal of butyrate.
4. In contrast, exposure of extracolonic cells to butyrate, including cervical cancer (HeLa) and laryngeal cancer (HEp-2) cell lines in this study and hepatoblastoma cells (Hep G2) in our previous work, caused no detectable changes in ganglioside expression.
5. In conclusion, our results indicate a relative tissue specificity of butyrate-mediated alterations in ganglioside expression that is not universal but is limited to specific gangliosides.
A New Non-Invasive Statistical Method to Assess the Spontaneous Cardiac Baroreflex in Humans
Authors: Ducher Michel , Fauvel Jean Pierre , Gustin Marie Paule , Cerutti Catherine , Najem Robert , Cuisinaud Guy , Laville Maurice , Pozet Nicole , Paultre Christian Zacharie 
Published: August 2015

1. A new method was developed to evaluate cardiac baroreflex sensitivity. The association of a high systolic blood pressure with a low heart rate or the converse is considered to be under the influence of cardiac baroreflex activity. This method is based on the determination of the statistical dependence between systolic blood pressure and heart rate values obtained non-invasively by a Finapres device. Our computerized analysis selects the associations with the highest statistical dependence. A ‘Z-coefficient’ quantifies the strength of the statistical dependence. The slope of the linear regression, computed on these selected associations, is used to estimate baroreflex sensitivity.
2. The present study was carried out in 11 healthy resting male subjects. The results obtained by the ‘Z-coefficient’ method were compared with those obtained by cross-spectrum analysis, which has already been validated in humans. Furthermore, the reproducibility of both methods was checked after 1 week.
3. The results obtained by the two methods were significantly correlated (r = 0.78 for the first and r = 0.76 for the second experiment, P &lt; 0.01). When repeated after 1 week, the average results were not significantly different. Considering individual results, test—retest correlation coefficients were higher with the Z-analysis (r = 0.79, P &lt; 0.01) than with the cross-spectrum analysis (r = 0.61, P &lt; 0.05).
4. In conclusion, as the Z-method gives results similar to but more reproducible than the cross-spectrum method, it might be a powerful and reliable tool to assess baroreflex sensitivity in humans.