The distal colon provides reserve storage capacity during colonic fluid overload.
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ABSTRACT:
SUBMITTER: Hammer J
PROVIDER: S-EPMC1891583 | biostudies-other | 1997 Nov
REPOSITORIES: biostudies-other
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Project description:BackgroundRecovery after colonic surgery is invariably delayed by disturbed gut motility. It is commonly assumed that colonic motility becomes quiescent after surgery, but this hypothesis has not been evaluated rigorously. This study quantified colonic motility through the early postoperative period using high-resolution colonic manometry.MethodsFibre-optic colonic manometry was performed continuously before, during and after surgery in the left colon and rectum of patients undergoing right hemicolectomy, and in healthy controls. Motor events were characterized by pattern, frequency, direction, velocity, amplitude and distance propagated.ResultsEight patients undergoing hemicolectomy and nine healthy controls were included in the study. Colonic motility became markedly hyperactive in all operated patients, consistently dominated by cyclic motor patterns. Onset of cyclic motor patterns began to a minor extent before operation, occurring with increasing intensity nearer the time of surgery; the mean(s.d.) active duration was 12(7) per cent over 3 h before operation and 43(17) per cent within 1 h before surgery (P = 0.024); in fasted controls it was 2(4) per cent (P < 0·001). After surgery, cyclic motor patterns increased markedly in extent and intensity, becoming nearly continuous (active duration 94(13) per cent; P < 0·001), with peak frequency 2-4 cycles per min in the sigmoid colon. This postoperative cyclic pattern was substantially more prominent than in non-operative controls, including in the fed state (active duration 27(20) per cent; P < 0·001), and also showed higher antegrade velocity (P < 0·001).ConclusionDistal gut motility becomes markedly hyperactive with colonic surgery, dominated by cyclic motor patterns. This hyperactivity likely represents a novel pathophysiological aspect of the surgical stress response. Hyperactive motility may contribute to gut dysfunction after surgery, potentially offering a new therapeutic target to enhance recovery.
| S-EPMC7938810 | biostudies-literature
Project description:Accelerated loss of adipose tissue in cancer is associated with shorter survival, and reduced quality of life. Evidence is emerging suggesting tumour association with alterations in adipose tissue, but much less is known about drug-related mechanisms contributing to adipose atrophy. Identification of mechanisms by which tumour and cancer treatments, such as chemotherapy, affect adipose tissue are required to develop appropriate therapeutic interventions to prevent fat depletion in cancer. This pre-clinical study aimed to assess alterations in adipose tissue during the clinical course of cancer.Fischer 344 rats bearing the Ward colorectal tumour were euthanized before chemotherapy, after 1- cycle, or 2-cycles of a combination chemotherapy consisting of Irinotecan (CPT-11) combined with 5-fluorouracil (5-FU), which recapitulates first line treatment for human colorectal cancer. Periuterine adipose tissue was isolated. Healthy rats served as a reference group. Histological analysis (hematoxylin and eosin), Real-time PCR (TaqMan) and proteomic analysis (LC-MS/MS) were performed.Larger adipocytes (3993.7?±?52.6 ?m2) in tumour-bearing animals compared to the reference group (3227.7?±?36.7 ?m2; p?<?0.001) was associated with reduced expression of proteins involved in mitochondrial fatty acid oxidation. The presence of a tumour has a significant effect on phospholipid but not triglyceride fatty acid composition. There were greater proportions of saturated fatty acids concurrent with lower monounsaturated fatty acids within the PL fraction of adipocytes in tumour-bearing animals. Chemotherapy treatment decreased the size of adipocytes (2243.9?±?30.4 ?m2; p?<?0.001) and led to depletion of n-3 polyunsaturated fatty acids in adipose tissue triglyceride. Evaluation of the proteome profile revealed decreased expression of proteins involved in ATP generation, ?-oxidation, and lipogenesis. Overall, adipose tissue may not be able to efficiently oxidize fatty acids to provide energy to maintain energy demanding pathways like lipogenesis inside the tissue.In conclusion, metabolic adaptations to mitochondrial impairment may contribute to diminished lipid storage capacity of adipose tissue following chemotherapy delivery.
| S-EPMC5735884 | biostudies-other
Project description:BackgroundIntradialytic hypertension (IDH) increases morbidity and mortality. The prevalence in South Africa is unknown. The pathogenesis is unclear, but it has been suggested that IDH may be due to subclinical fluid overload. The objective of this study was to determine the prevalence of IDH and to evaluate its association with fluid overload using bioimpedance spectroscopy (BIS).MethodsA cross-sectional study involving 190 chronic haemodialysis patients in the Western Cape province of South Africa was conducted between January 2013 and May 2014. IDH was defined as a >10 mmHg increase in systolic blood pressure in at least four of six prior consecutive haemodialysis sessions.ResultsThe prevalence of IDH was 28.4% (n = 54). There was a trend towards pre-dialysis overhydration in the IDH group when compared with controls {2.6 L [95% confidence interval (CI) 1.7-3.4] versus 1.8 L [95% CI 1.4-2.1], respectively; P = 0.06} as measured by BIS, but no difference in mean ultrafiltration (UF) volume (2.4 versus 2.6 L; P = 0.30). A trend towards greater use of antihypertensive drugs was noted in the IDH group [2.5 drugs (95% CI 2.15-2.87) versus 2.1 (95% CI 1.82-2.30); P = 0.05]. More participants in the IDH group received calcium channel blockers (54 versus 36; P = 0.03).ConclusionsThe prevalence of IDH in our treatment centres is much higher than previously reported. Subclinical fluid overload may be a major contributing factor to the mechanism of this condition. The use of BIS identifies patients who may benefit from additional UF.
| S-EPMC4957728 | biostudies-literature
Project description:Sustained fluid overload (FO) is considered a major cause of hypertension, heart failure, and mortality in patients with ESRD on maintenance hemodialysis. However, there has not been a cohort study investigating the relationship between chronic exposure to FO and mortality in this population. We studied the relationship of baseline and cumulative FO exposure over 1 year with mortality in 39,566 patients with incident ESRD in a large dialysis network in 26 countries using whole-body bioimpedance spectroscopy to assess fluid status. Analyses were applied across three discrete systolic BP (syst-BP) categories (<130, 130-160, and >160 mmHg), with nonoverhydrated patients with syst-BP=130-160 mmHg as the reference category; >200,000 FO measurements were performed over follow-up. Baseline FO value predicted excess risk of mortality across syst-BP categories (<130 mmHg: hazard ratio [HR], 1.51; 95% confidence interval [95% CI], 1.38 to 1.65; 130-160 mmHg: HR, 1.25; 95% CI, 1.16 to 1.36; >160 mmHg: HR, 1.30; 95% CI, 1.19 to 1.42; all P<0.001). However, cumulative 1-year FO exposure predicted a higher death risk (P<0.001) across all syst-BP categories (<130 mmHg: HR, 1.94; 95% CI, 1.68 to 2.23; 130-160 mmHg: HR, 1.51; 95% CI, 1.35 to 1.69; >160 mmHg: HR, 1.62; 95% CI, 1.39 to 1.90). In conclusion, chronic exposure to FO in ESRD is a strong risk factor for death across discrete BP categories. Whether treatment policies that account for fluid status monitoring are preferable to policies that account solely for predialysis BP measurements remains to be tested in a clinical trial.
| S-EPMC5533242 | biostudies-literature
Project description:Intestinal microbiota influences the progression of colitis-associated colorectal cancer. With diet being a key determinant of the gut microbial ecology, dietary interventions are an attractive avenue for the prevention of colitis-associated colorectal cancer. Curcumin is the most active constituent of the ground rhizome of the Curcuma longa plant, which has been demonstrated to have anti-inflammatory, antioxidative, and antiproliferative properties.Il10 mice on 129/SvEv background were used as a model of colitis-associated colorectal cancer. Starting at 10 weeks of age, wild-type or Il10 mice received 6 weekly intraperitoneal injections of azoxymethane (AOM) or phosphate-buffered saline (PBS) and were started on either a control or a curcumin-supplemented diet. Stools were collected every 4 weeks for microbial community analysis. Mice were killed at 30 weeks of age.Curcumin-supplemented diet increased survival, decreased colon weight/length ratio, and, at 0.5%, entirely eliminated tumor burden. Although colonic histology indicated improvement with curcumin, no effects of mucosal immune responses have been observed in PBS/Il10 mice and limited effects were seen in AOM/Il10 mice. In wild-type and in Il10 mice, curcumin increased bacterial richness, prevented age-related decrease in alpha diversity, increased the relative abundance of Lactobacillales, and decreased Coriobacterales order. Taxonomic profile of AOM/Il10 mice receiving curcumin was more similar to those of wild-type mice than those fed control diet.In AOM/Il10 model, curcumin reduced or eliminated colonic tumor burden with limited effects on mucosal immune responses. The beneficial effect of curcumin on tumorigenesis was associated with the maintenance of a more diverse colonic microbial ecology.
| S-EPMC4615313 | biostudies-literature
Project description:BACKGROUND:Bulbs of the ornamental flower Lilium pumilum enter a period of dormancy after flowering in spring, and require exposure to cold for a period of time in order to release dormancy. Previous studies focused mainly on anatomical, physiological and biochemical changes during dormancy release. There are no dormancy studies of the northern cold-hardy wild species of Lilium at the molecular level. This study observed bulb cell and starch granule ultrastructures during cold storage; and analysed the transcriptome using sequencing. The combination of morphological and transcriptomic methods provides valuable insights into dormancy release during cold storage of Lilium pumilum. RESULTS:Ultrastructural changes reflected dormancy release during cold storage of the bulbs. We compared gene expression levels among samples at 0 (S1 stage), 30 (S2 stage), 60 (S3 stage) and 90 (S4 stage) d of cold storage, with 0 d as the control. The data showed that some regulatory pathways such as carbohydrate metabolism and plant hormone signal transduction were activated to break dormancy. Some differentially expressed genes (DEGs) related to antioxidant activity, epigenetic modification and transcription factors were induced to respond to low temperature conditions. These genes constituted a complex regulatory mechanism of dormancy release. CONCLUSIONS:Cytological data related to dormancy regulation was obtained through histomorphological observation; transcriptome sequencing provided comprehensive sequences and digital gene expression tag profiling (DGE) data, and bulb cell ultrastructural changes were closely related to DEGs. The novel Lilium pumilum genetic information from this study provides a reference for the regulation of dormancy by genetic engineering using molecular biology tools.
| S-EPMC6389108 | biostudies-literature
Project description:Aim To identify genes specifically involved in the storage reserve mobilisation programme in Arabidopsis. Background During germination and early post-germinative growth in Arabidopsis seed storage reserves are broken down to provide energy and nutrients for the developing seedling. Genes encoding enzymes involved in the mobilisation of both storage lipid and protein are expressed strongly 1-2 days following imbibition and then fall to very low levels. The regulatory mechanisms controlling expression of these genes are poorly understood. Although germination and reserve mobilisation occur at the same time we have obtained evidence using Abscisic Acid (ABA) treated seeds that the events are regulated by two separate programmes. Arabidopsis seeds treated with 10mM ABA still express genes involved in the mobilisation of storage reserves and break down storage lipid even though germination is blocked. ABA treated seeds therefore provide a powerful system for the identification of genes involved specifically in the reserve mobilisation programme. Microarray analysis will allow us to gain a global undertanding of the processes involved in storage reserve mobilisation and should also result in the identification of regulatory genes involved in this process. Experimental Set-up All seeds are Col-4 imbibed on plates containing 1/2 MS media for 4 days in the dark. All plant material will be grown in controlled environment growth rooms under defined light and temperature regimes. There are two parts to the experimental design. 1. Time course to identify genes involved in both seed storage reserve and germination programmes Comparison of mRNAs from seeds immediately after imbibition (storage reserve and germination programme genes being induced) with 2 day (storage reserve genes maximally expressed) and 7 day old seedlings (storage reserve and germination programme genes off, photoautotrophic genes on) will allow the identification of genes exclusively presentor present at enhanced levels at the peak of reserve mobilisation (day 2). 2. ABA treatment experiment to identify genes involved in the storage reserve programme ABA treatment blocks germination but does not block reserve mobilisation. Microarray analysis will be performed on RNA isolated from 2 day old seed imbibed in the presence of 10mM ABA. Comparison of the results of this experiment with those of the time course experiment should allow us to distinguish between genes involved in the two major programmes that we have uncovered. Keywords: development_or_differentiation_design
2007-01-22 | GSE6173 | GEO
Project description:ObjectivesAerobic reserve capacity reflects the available energy for performing everyday life tasks, and it has been studied in older adult populations. This preliminary study examined proof of concept and measurement of aerobic reserve capacity in multiple sclerosis (MS).Materials & methodsTwenty-one fully ambulatory people with MS performed a maximal, cardiopulmonary exercise test (CPET). We calculated aerobic reserve capacity based on the difference between peak aerobic power (VO2peak ) and first stage oxygen consumption (VO2 ). Participants completed assessments for disability (Expanded Disability Status Scale, EDSS), cognition (Symbol Digit Modalities Test, SDMT), mood (Beck Depression Inventory, BDI), walking endurance (six-minute walk distance, 6MWD), walking speed (Timed Twenty-Foot Walk, T25FW), impact of MS (Multiple Sclerosis Impact Scale, MSIS-29), and anthropometric measurements (height and weight).ResultsAerobic reserve capacity was 9.3 ± 3.7 ml/kg/min. Aerobic reserve capacity was positively associated with VO2peak (ρ = .67, p < .01), time to exhaustion (ρ = .63, p < .01), and SDMT (ρ = .51, p < .05). Aerobic reserve capacity was negatively associated with BMI (ρ = -.62, p < .01) and RHR (ρ = -0.47, p < .05).ConclusionWe provide preliminary evidence that aerobic reserve capacity is a feasible outcome derived from maximal CPET (eg, modified Balke protocol) in MS. Aerobic reserve capacity was associated with clinically relevant outcomes and could become an important outcome for rehabilitation in future research.
| S-EPMC9270568 | biostudies-literature
Project description:The colon is densely innervated by nociceptor neurons. Single cell RNA sequencing (scRNA-seq) of colon epithelial cells was performed to analyze the role of nociceptor neurons and Ramp1 signaling in regulating colonic epithelial cells.
2022-10-01 | GSE208762 | GEO
Project description:BackgroundContinuous agitation during storage slows down the platelet storage lesions. However, in special circumstances, manual-mixing can be alternatively used to store products for short time periods without compromising platelet quality. Based on this finding, and given the role of shear stress in modulating receptor expression, we were interested in comparing the levels of platelet adhesion receptor, GPVI and platelet adhesion capacity under each storage condition.MethodsPlatelet concentrates (PCs) were divided into three groups: continuously-agitated PCs (CAG-PCs) with or without PP2 (Src kinase inhibitor) and manually-mixed PCs (MM-PCs). Platelet count/MPV, swirling, GPVI and P-selectin expression, GPVI shedding, platelet adhesion/spreading to collagen were examined during 5 days of storage.ResultsWhile MM- and CAG-PCs showed similar levels of P-selectin expression, GPVI expression was significantly elevated in MM-PCs with lower GPVI shedding/expression ratios, enhanced platelet adhesion/spreading and swirling in manually-mixed PCs. Of note, CAG-PCs treated with PP2 also demonstrated lower P-selectin expression and GPVI shedding, higher GPVI expression and attenuated swirling and spreading capability.ConclusionGiven the comparable platelet activation state in MM and CAG-PCs as indicated by P-selectin expression, enhanced platelet adhesion/spreading in MM-PCs, along with relatively higher GPVI expression here, supports previous studies demonstrating a role for biomechanical forces in modulating GPVI-dependent function. Thus, lower GPVI expression in CAG-PCs may be due to shear forces induced by agitation, which keeps this receptor down-regulated while also attenuating platelet adhesion/spreading capacities during storage. Low platelet function in PP2-CAG-PCs also highlights the importance of Src-kinases threshold activity in maintaining platelets quality.
| S-EPMC8756730 | biostudies-literature