Modulatory influences on antegrade and retrograde tonic reflexes in the colon and rectum

2004 ◽  
Vol 287 (5) ◽  
pp. G962-G966 ◽  
Author(s):  
Clinton Ng ◽  
Mark Danta ◽  
Gillian Prott ◽  
Caro-Anne Badcock ◽  
John Kellow ◽  
...  
Keyword(s):  
Volume Change ◽  
Random Order ◽  
Tonic Contraction ◽  
Fasting State ◽  
Rectal Distension ◽  
Tonic Response ◽  
Rectal Volume ◽  
Before And After ◽  
Colon And Rectum ◽  
Colonic Distension

Tonic reflexes in the colon and rectum are likely to be important in health and in disorders of gastrointestinal function. The aim of this study was to evaluate the fasting and postprandial “colorectal” and “rectocolic” reflexes in response to 2-min isobaric distensions of the colon and rectum, accounting for enteric sensation, compliance, and distending balloon volume. In 14 healthy fasting subjects, a dual barostat assembly was positioned (descending colon and rectum). A 2-min phasic distension was performed in the colon and rectum in random order while the opposing balloon volume was recorded. Sensation (phasic distension) and compliance (ramp distension) were also determined. The experiment was repeated postprandially. Colonic distension resulted in significant rectal tonic contraction in the fasting (rectal volume change: −35.4 ± 8.4 ml, P < 0.01) and postprandial (−22.2 ± 8.4 ml, P < 0.01) states. After adjustment for colonic sensitivity, for compliance, and for distending balloon volume, the rectal volume change remained significant; the extent of the tonic response, however, correlated significantly with increasing pain score ( P < 0.01). In contrast, rectal distension did not produce a significant tonic response in the colon (fasting: −6.5 ± 7.3 ml; postprandial: 2.7 ± 7.3 ml), either unadjusted or adjusted for rectal sensitivity, compliance, and distending balloon volume. In conclusion, the colorectal reflex, but not the rectocolic reflex, can be readily demonstrated both before and after a meal in response to a 2-min isobaric distension in the colon and rectum, respectively. Although the presence of the colorectal reflex does not depend on colonic sensitivity or the volume of the distending colonic balloon, these factors modulate the reflex, especially in the fasting state.

scholarly journals Acute effects of tea on fasting and non-fasting plasma total homocysteine concentrations in human subjects

2007 ◽  
Vol 97 (5) ◽  
pp. 842-846 ◽  
Author(s):  
Jonathan M. Hodgson ◽  
Ian B. Puddey ◽  
Frank M. van Bockxmeer ◽  
Valerie Burke
Keyword(s):  
Human Subjects ◽  
Random Order ◽  
Black Tea ◽  
Acute Effect ◽  
Hot Water ◽  
Fasting State ◽  
Cvd Risk ◽  
Acute Increase ◽  
Total Homocysteine ◽  
Plasma Total Homocysteine

Plasma total homocysteine concentrations (tHcy) are a putative risk factor for CVD. Tea is a rich dietary source of polyphenols and caffeine, both of which may raise tHcy. However, it is possible that much of any effect is transitory and may be influenced by the consumption of food. Our objective was to investigate the acute effect of tea, at a dose representative of ordinary population intakes, on tHcy and to determine whether consumption of a meal influences the magnitude of any effect. Measurements of tHcy were performed in twenty participants at baseline and 3.5 h after drinking three cups of black tea or hot water (consumed at time 0, 1.5 and 3 h) with and without a meal: a total of four treatments administered in random order. Drinking tea resulted in an acute increase in tHcy (0·30 (95 % CI 0·04, 0·56) μmol/l, P = 0·022). The meal resulted in an acute decrease in tHcy ( − 0·42 (95 % CI − 0·68, − 0·16) μmol/l, P = 0·002). There was no interaction between tea and meal on tHcy (P = 0·40); that is, the effect of tea on tHcy was not different in the fasting and non-fasting state. Our results suggest that drinking black tea can cause a small acute increase in tHcy and that this effect is not enhanced in the non-fasting state. Given that results of population studies have generally shown a negative association between tea intake and tHcy, the significance of these findings to CVD risk remains uncertain.

scholarly journals ACUTE CARDIOVASCULAR RESPONSE TO PRE-PRANDIAL AND POSTPRANDIAL EXERCISE IN ACTIVE MEN

2017 ◽  
Vol 23 (5) ◽  
pp. 380-384
Author(s):  
Márcio Rabelo Mota ◽  
Sandro Nobre Chaves ◽  
Maurílio Tiradentes Dutra ◽  
Ricardo Jacó de Oliveira ◽  
Renata Aparecida Elias Dantas ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Cardiovascular Response ◽  
Rate Pressure Product ◽  
Fasting State ◽  
Physically Active ◽  
Significance Level ◽  
Factorial Anova ◽  
Before And After ◽  
Cardiovascular Variables ◽  
Male Subjects

ABSTRACT Introduction: Pre-prandial exercise promotes greater mobilization of fat metabolism due to the increased release of catecholamines, cortisol, and glucagon. However, this response affects how the cardiovascular system responds to exercise. Objective: To evaluate the response of systolic, diastolic, and mean blood pressure, heart rate (HR) and rate-pressure product (RPP) to pre- and postprandial exercise. Methods: Ten physically active male subjects (25.50 ± 2.22 years) underwent two treadmill protocols (pre- and postprandial) performed for 36 minutes at 65% of VO2max on different days. On both days, subjects attended the laboratory on a 10-hour fasting state. For the postprandial session, volunteers ingested a pre-exercise meal of 349.17 kcal containing 59.3 g of carbohydrates (76.73%), 9.97 g of protein (12.90%), and 8.01 g of lipids (10.37%). Blood pressure, HR and RPP were measured before and after exercise. The 2x2 factorial Anova with the multiple comparisons test of Bonferroni was applied to analyze cardiovascular variables in both moments (pre- vs. postprandial). The significance level was set at p<0.05. Results: Systolic (121.70 ± 7.80 vs. 139.78 ± 12.91 mmHg) and diastolic blood pressure (66.40 ± 9.81 vs. 80.22 ± 8.68 mmHg) increased significantly after exercise only in the postprandial session (p<0.05). HR increased significantly (p<0.05) after both protocols (64.20 ± 15.87 vs. 141.20 ± 10.33 bpm pre-prandial and 63.60 ± 8.82 vs. 139.20 ± 10.82 bpm postprandial). RPP had a similar result (8052.10 ± 1790.68 vs. 18382.60 ± 2341.66 mmHg.bpm in the pre-prandial session and 7772.60 ± 1413.76 vs. 19564.60 ± 3128.99 mmHg.bpm in the postprandial session). Conclusion: These data suggest that fasted exercise does not significantly alter the blood pressure. Furthermore, the meal provided before the postprandial exercise may promote a greater blood pressure responsiveness during exercise.

scholarly journals Effects of Adding Small Combat Games to Regular Taekwondo Training on Physiological and Performance Outcomes in Male Young Athletes

2021 ◽  
Vol 12 ◽  
Author(s):  
Ibrahim Ouergui ◽  
Emerson Franchini ◽  
Hamdi Messaoudi ◽  
Hamdi Chtourou ◽  
Anissa Bouassida ◽  
...  
Keyword(s):  
Perceived Exertion ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Random Order ◽  
Performance Outcomes ◽  
Rating Of Perceived Exertion ◽  
Control Group ◽  
Metabolic Demand ◽  
Before And After ◽  
Post Hoc

This study investigated the effect of area sizes (4 × 4, 6 × 6, and 8 × 8 m) and effort-pause ratios (free combat vs. 1:2) variation on the physiological and perceptive responses during taekwondo combats (Study 1). In a second study, the effects on physical performance of 8 weeks of small combat-based training added to regular taekwondo training were investigated (Study 2). In random order, 32 male taekwondo athletes performed six (i.e., two effort-to-pause ratios × three area sizes conditions) different 2-min taekwondo combats (Study 1). Thereafter (Study 2), they were randomly assigned to three experimental groups (4 × 4, 6 × 6, and 8 × 8 m) and an active control group (CG). Regarding Study 1, blood lactate concentration [La] before and after each combat, mean heart rate (HRmean) during each combat, and rating of perceived exertion (CR-10) immediately after each combat were assessed. Regarding Study 2, progressive specific taekwondo (PSTT) to estimate maximum oxygen consumption (VO2max), taekwondo-specific agility, and countermovement jump (CMJ) tests were administered before and after 8 weeks of training. Study 1 results showed that 4 × 4 m elicited lower HRmean values compared with 6 × 6 m (d = −0.42 [small], p = 0.030) and free combat induced higher values compared with the 1:2 ratio (d = 1.71 [large], p &lt; 0.001). For [La]post, 4 × 4 m area size induced higher values than 6 × 6 m (d = 0.99 [moderate], p &lt; 0.001) and 8 × 8 m (d = 0.89 [moderate], p &lt; 0.001) and free combat induced higher values than 1:2 ratio (d = 0.69 [moderate], p &lt; 0.001). Higher CR-10 scores were registered after free combat compared with 1:2 ratio (d = 0.44 [small], p = 0.007). For Study 2, VO2max increased after training [F(1, 56) =30.532, p &lt; 0.001; post-hoc: d = 1.27 [large], p &lt; 0.001] with higher values for 4 × 4 m compared with CG (d = 1.15 [moderate], p = 0.009). Agility performance improved after training [F(1, 56) = 4.419, p = 0.04; post-hoc: d = −0.46 [small], p = 0.04] and 4 × 4 m induced lower values in comparison with 6 × 6 m (d = −1.56 [large], p = 0.001) and CG (d = −0.77 [moderate], p = 0.049). No training type influenced CMJ performance. Smaller area size elicited contrasting results in terms of metabolic demand compared with larger sizes (i.e., lower HRmean but higher [La] and CR-10), whereas free combat induced variables' consistently higher values compared with imposed 1:2 ratio (Study 1). Taekwondo training is effective to improve VO2max and agility (Study 2), but small combat training modality should be investigated further.

Effect of mannitol on globe and orbital volumes in humans

2018 ◽  
Vol 28 (2) ◽  
pp. 163-167 ◽  
Author(s):  
Adam C. Weber ◽  
Alexander D. Blandford ◽  
Bryan R. Costin ◽  
Julian D. Perry
Keyword(s):  
Volume Change ◽  
Cleveland Clinic ◽  
Retrospective Chart Review ◽  
Consecutive Series ◽  
Orbital Volume ◽  
Computed Tomographic ◽  
Before And After ◽  
Pressure Lowering ◽  
Volume Measurements

Purpose: To determine the effect of intravenous mannitol on globe and orbital volumes. Methods: Retrospective chart review of a consecutive series of Cleveland Clinic Neurosurgical Intensive Care Unit patients who underwent computed tomographic imaging before and after intravenous mannitol administration. Volume measurements were performed according to a previously described technique by averaging axial image areas. Measurements before and after mannitol administration were compared using paired t-test. Results: Fourteen patients (28 eyes) met inclusion criteria. Average globe volume decreased 186 mm3 (-2.5%, p = 0.02) after mannitol administration, while average orbital volume increased 353 mm3 (+3.5%, p = 0.04). Average globe volume change for subjects with follow-up scan less than 4.7 hours (mean 1.9 hours; range 0.2-4.5 hours) after mannitol administration was -125 mm3 (-1.7%, p = 0.24) and average orbital volume change was +458 mm3 (+5.1%, p = 0.11). Average globe volume change after mannitol administration for those with follow-up more than 4.7 hours (average 13.9 hours, range 4.9-24.7 hours) was -246 mm3 (-3.3%, p = 0.05) and orbital volume change was +248 mm3 (+2.2%, p = 0.24). Dividing the study population into groups based on mannitol dose did not yield any statistically significant change. Conclusions: Human globe volume decreases after intravenous mannitol administration, while orbital volume increases. These volume changes occur during the time period when intraocular pressure normalizes, after the pressure-lowering effects of the drug. This novel volumetric information improves our understanding of mannitol’s mechanism of action and its effects on human ocular and periocular tissues.

scholarly journals Dexamethasone in resting and exercising men. I. Effects on bioenergetics, minerals, and related hormones

1999 ◽  
Vol 87 (1) ◽  
pp. 175-182 ◽  
Author(s):  
P. Marquet ◽  
G. Lac ◽  
A. P. Chassain ◽  
G. Habrioux ◽  
F. X. Galen
Keyword(s):  
Ventilatory Threshold ◽  
Exercise Bout ◽  
Random Order ◽  
Blood Levels ◽  
High Dose ◽  
Double Blind ◽  
Men I ◽  
Before And After ◽  
Blood Pressures ◽  
Rest And Exercise

A placebo and a low and a high dose of dexamethasone (Dex) were administered for 4.5 days, at 3-wk intervals, to 24 healthy men, following a double-blind, random-order, crossover procedure. After the last dose the subjects performed a maximal cycling exercise, during which respiratory exchanges, electrocardiogram, and blood pressures were monitored. Blood was sampled just before and after each exercise bout. Dex showed no significant effect on fitness, sleep, exhaustion during exercise, maximal O2 consumption, ventilatory threshold, maximal blood lactate, or rest and exercise blood pressures. On the contrary, both doses of Dex significantly decreased heart rate at rest and during maximal exercise. Blood glucose at rest was higher after both doses of Dex than after placebo; the opposite was found during exercise. Blood levels of ACTH, β-endorphin, cortisol, and cortisol-binding globulin were lowered by Dex at rest and after exercise. Dex stimulated the increase in atrial natriuretic factor during exercise and lowered rest and postexercise aldosterone. Finally, no difference between “fit or trained” and “less fit or untrained” subjects could be found with respect to Dex effects.

Insulin resistance of skeletal muscle produced by hepatic parasympathetic interruption

1996 ◽  
Vol 270 (5) ◽  
pp. E858-E863 ◽  
Author(s):  
H. Xie ◽  
W. W. Lautt
Keyword(s):  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Liver Disease ◽  
Portal Vein ◽  
Combined Treatment ◽  
Random Order ◽  
Acute Effect ◽  
Parasympathetic Nerves ◽  
Before And After ◽  
Insulin Dependent

The objective was to determine the site of insulin resistance produced by intraportal atropine or surgical hepatic denervation. A modified euglycemic clamp was used in fasted cats to test the acute effect of insulin (100 mU/kg) on arteriovenous glucose gradients across the hindlimbs (mainly reflecting skeletal muscle), the guts (all organs draining into the portal vein), and the liver. Responses to insulin were determined before and after hepatic denervation and after 3 mg/kg intraportal atropine. The interventions were done in random order. Responses after either intervention were similar and were not potentiated by the combined treatment. Regional insulin resistance was assessed by comparing the change in glucose gradients in response to insulin before and after treatments. Hepatic and gut responses to insulin were unaltered, but hindlimb responses were significantly impaired after denervation or atropine. We speculate that the hepatic parasympathetic nerves regulate release of a liver-generated factor that selectively controls insulin effectiveness in skeletal muscle. This mechanism may be involved with insulin resistance in non-insulin-dependent diabetes and chronic liver disease.

Time-dependent dose distribution changes in prostate brachytherapy with iodine seeds.

2018 ◽  
Vol 36 (6_suppl) ◽  
pp. 115-115
Author(s):  
Charles Teyssier ◽  
Magali Quivrin ◽  
Julie Blanc ◽  
Aurelie Petitfils ◽  
Fabienne Bidault ◽  
...  
Keyword(s):  
Ct Scan ◽  
Dose Distribution ◽  
Half Life ◽  
Time Dependent ◽  
Prostate Brachytherapy ◽  
Rectal Distension ◽  
Cross Sectional ◽  
Rectal Volume ◽  
Dose Metrics ◽  
Over Time

115 Background: Prostate brachytherapy with iodine seeds has a lasting dose delivery due to a long half life of I125 (i.e. 2 months). To assess changes in dose metrics over time in low-dose rate prostate brachytherapy with iodine seeds and its relationship with rectal distension. Methods: One hundred and twenty-one post-implant CT scans performed every 2 weeks over 2 months after the treatment procedure were analyzed for dosimetry. Each CT-scan was performed without and with rectal enema. The following rectal parameters were collected to evaluate the influence of rectal distension over time: rectal volume, cross-sectional surface area (CSA) and relative CSA calculated from the first CT-scan chosen as reference (CTref). Results: Mean V150% and V200% of the prostate volume increased significantly over time (p < 0.0001) and were significantly higher on postimplant CT scan performed at day 45 (CT45) (p = 0.024 and p = 0.003, respectively) and CT scan performed at day 60 (CT60) (p = 0.0005 and p < 0.0001, respectively) compared with CTref. All dosimetric parameters for the rectum were significantly increased over time. No rectal parameters were significantly different after rectal enema and there was no difference in doses delivered to the prostate and the rectum after rectal emptying. Conclusions: Increased hot spots in the prostate and the rectum during the 2 months following the procedure with iodine seeds may be related to prostate shrinkage rather than rectal distension. We hypothesize that radioelements with shorter half-life (Pd103 or Cs131) or HDR may give less toxicity, as dose distribution is less time-dependent.

scholarly journals Evaluative Conditioning with Facial Stimuli in Dementia Patients

2013 ◽  
Vol 2013 ◽  
pp. 1-6
Author(s):  
Andreas Blessing ◽  
Jacqueline Zöllig ◽  
Roland Weierstall ◽  
Gerhard Dammann ◽  
Mike Martin
Keyword(s):  
Random Order ◽  
Evaluative Conditioning ◽  
Control Group ◽  
Healthy Controls ◽  
Conditioning Paradigm ◽  
Facial Stimuli ◽  
Dementia Patients ◽  
Before And After ◽  
Rating Changes ◽  
Unfamiliar Faces

We present results of a study investigating evaluative learning in dementia patients with a classic evaluative conditioning paradigm. Picture pairs of three unfamiliar faces with liked, disliked, or neutral faces, that were rated prior to the presentation, were presented 10 times each to a group of dementia patients (N = 15) and healthy controls (N = 14) in random order. Valence ratings of all faces were assessed before and after presentation. In contrast to controls, dementia patients changed their valence ratings of unfamiliar faces according to their pairing with either a liked or disliked face, although they were not able to explicitly assign the picture pairs after the presentation. Our finding suggests preserved evaluative conditioning in dementia patients. However, the result has to be considered preliminary, as it is unclear which factors prevented the predicted rating changes in the expected direction in the control group.

scholarly journals Circulating levels of incretin hormones and amylin in the fasting state and after oral glucose in GH-deficient patients before and after GH replacement: a placebo-controlled study

2000 ◽  
pp. 593-599 ◽  
Author(s):  
JO Jorgensen ◽  
AM Rosenfalck ◽  
S Fisker ◽  
B Nyholm ◽  
MS Fineman ◽  
...  
Keyword(s):  
Placebo Group ◽  
Pancreatic Beta Cells ◽  
Plasma Concentrations ◽  
Controlled Study ◽  
Oral Glucose ◽  
Fasting State ◽  
Gh Treatment ◽  
Double Blind ◽  
Gh Replacement ◽  
Before And After

OBJECTIVE: Hyperinsulinemia in association with GH excess is considered a compensatory response to insulin resistance, but the possibility of alternative insulinotropic mechanisms has not been investigated in vivo. It is also unknown how GH influences the secretion from pancreatic beta-cells of amylin, a peptide which regulates prandial glucose homeostasis and may be linked to development of beta-cell dysfunction. We therefore measured plasma concentrations of two gut insulinotropic hormones, glucagon-like peptide 1 (GLP-1) and glucose-dependent insulin-releasing peptide (GIP), and total as well as non-glycosylated amylin, in 24 GH-deficient adults before and after 4 months of GH replacement (daily evening injections of 2 IU GH/m). DESIGN: Double-blind, placebo-controlled, parallel study. METHODS: All participants underwent an oral glucose tolerance test (OGTT) at 0 and 4 months. RESULTS: A 33% suppression of fasting GLP-1 concentrations was measured in the GH group at 4 months (P=0.02), whereas a non-significant increase occurred in the placebo group (P=0.08). Fasting levels of GIP and amylin did not change significantly after 4 months in either group. The incremental response in GLP-1 during the OGTT was significantly lower after GH treatment as compared with both baseline (P=0.02) and the response in the placebo group (P=0. 03). The stimulation of GIP secretion following OGTT was similar on all occasions. The OGTT-induced incremental response in non-glycosylated amylin was moderately elevated after GH treatment as compared with placebo (P=0.05). Plasma concentrations of glucose and insulin, both in the fasting state and after the OGTT, were higher after GH treatment, but the ratio between amylin and insulin remained unchanged. CONCLUSIONS: GH-induced hyperinsulinemia is accompanied by proportionate elevations in amylin concentrations and a blunting of gut GLP-1 secretion. The mechanisms underlying the suppression of GLP-1 remain to be elucidated.

scholarly journals Anorectal manometry in children with chronic functional constipation

2005 ◽  
Vol 42 (3) ◽  
pp. 178-181 ◽  
Author(s):  
Rosa Helena Monteiro Bigélli ◽  
Maria Inez Machado Fernandes ◽  
Yvone Avalloni de Moraes Villela de Andrade Vicente ◽  
Roberto Oliveira Dantas ◽  
Lívia Carvalho Galvão ◽  
...  
Keyword(s):  
Anal Sphincter ◽  
Anorectal Manometry ◽  
External Anal Sphincter ◽  
Standard Treatment ◽  
Functional Constipation ◽  
Residual Pressure ◽  
Rectal Distension ◽  
Normal Children ◽  
Basal Pressure ◽  
Before And After

BACKGROUND: The anorectal manometry is a very utilized and well recognized examination in children with chronic funcional constipation. The major manometric findings in these children are: anal hypotonia, anal hypertonia, paradoxal contraction of the external anal sphincter, decreased ability of internal anal sphincter to relax during rectal distension and alterations in rectal contractility, sensibility and compliance. AIMS: To evaluate the anal basal pressure and the relaxation reflex before and after standard treatment for a better understanding of the physiopathologic mechanisms involved in pediatric chronic functional constipation. METHODS: Anorectal manometry was performed before treatment on 20 children with chronic functional constipation aged 4 to 12 years and the results were compared to those obtained after standard treatment, with a good outcome. RESULTS: There was a reduction in anal basal pressure after treatment, but no differences were detected between the anorectal manometries performed before and after treatment in terms of amplitude and duration of relaxation, residual pressure, latency time, or descent and ascent angle. CONCLUSIONS: We conclude that the anal basal pressure decreased in children recovering from chronic functional constipation, but the standard treatment did not provide all the conditions necessary for the relaxation reflex of constipated children to return to the values described in normal children.

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