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The Veterinary Clinics of North... Aug 1997Strangulating large colon volvulus presents the surgeon with the dilemma of determining the extent of compromise to the affected tissue and the most appropriate surgical... (Review)
Review
Strangulating large colon volvulus presents the surgeon with the dilemma of determining the extent of compromise to the affected tissue and the most appropriate surgical treatment of this tissue. This decision is complicated because there is a significant volvulus recurrence rate. Large colon resection and anastomosis is the most aggressive treatment option but prevents recurrence and may provide an alternative to euthanasia for some horses.
Topics: Anastomosis, Surgical; Animals; Colon; Colonic Diseases; Horse Diseases; Horses; Postoperative Complications; Prognosis
PubMed: 9290187
DOI: 10.1016/s0749-0739(17)30243-2 -
Journal of Controlled Release :... Jan 2023Colonic drug delivery can facilitate access to unique therapeutic targets and has the potential to enhance drug bioavailability whilst reducing off-target effects.... (Review)
Review
Colonic drug delivery can facilitate access to unique therapeutic targets and has the potential to enhance drug bioavailability whilst reducing off-target effects. Delivering drugs to the colon requires considered formulation development, as both oral and rectal dosage forms can encounter challenges if the colon's distinct physiological environment is not appreciated. As the therapeutic opportunities surrounding colonic drug delivery multiply, the success of novel pharmaceuticals lies in their design. This review provides a modern insight into the key parameters determining the effective design and development of colon-targeted medicines. Influential physiological features governing the release, dissolution, stability, and absorption of drugs in the colon are first discussed, followed by an overview of the most reliable colon-targeted formulation strategies. Finally, the most appropriate in vitro, in vivo, and in silico preclinical investigations are presented, with the goal of inspiring strategic development of new colon-targeted therapeutics.
Topics: Drug Delivery Systems; Colon; Pharmaceutical Preparations; Administration, Oral; Biological Availability
PubMed: 36528195
DOI: 10.1016/j.jconrel.2022.12.029 -
Endoscopy Jun 2021Large prolapse-related lesions (LPRL) of the sigmoid colon have been documented histologically but may not be readily recognized endoscopically.
BACKGROUND
Large prolapse-related lesions (LPRL) of the sigmoid colon have been documented histologically but may not be readily recognized endoscopically.
METHODS
Colonic lesions referred for endoscopic mucosal resection (EMR) were enrolled prospectively. Endoscopic features were carefully documented prior to resection. Final diagnosis was made based on established histologic criteria, including vascular congestion, hemosiderin deposition, fibromuscular hyperplasia, and crypt distortion.
RESULTS
Of 134 large ( ≥ 20 mm) sigmoid lesions, 12 (9.0 %) had histologic features consistent with mucosal prolapse. Distinct endoscopic features were: broad-based morphology; vascular pattern obscured by dusky hyperemia; blurred crypts of varying size and shape; and irregular spacing of sparse crypts. Focal histologic dysplasia was identified in 6 of 12 lesions (50.0 %).
CONCLUSIONS
LPRL of the sigmoid colon exhibit a distinct endoscopic profile. Although generally non-neoplastic, dysplasia may be present, warranting consideration of EMR.
Topics: Colon; Colon, Sigmoid; Colonic Diseases; Endoscopic Mucosal Resection; Humans; Hyperplasia; Intestinal Mucosa; Prolapse
PubMed: 32961578
DOI: 10.1055/a-1248-2175 -
The Veterinary Clinics of North... Aug 1997Displacements and intraluminal obstructions of the large colon carry a good to excellent prognosis for long-term recovery, and surgery for these diseases is rarely... (Review)
Review
Displacements and intraluminal obstructions of the large colon carry a good to excellent prognosis for long-term recovery, and surgery for these diseases is rarely followed by short-term or long-term complications. Entrapment of the large colon over the renosplenic ligament is amenable to medical therapies so that surgery can be avoided in many cases. However, preoperative diagnosis of all nonstrangulating diseases of the large colon can be difficult. Vascular diseases of the large colon, such as thromboembolic diseases and large colon volvulus, are more difficult to treat and carry a poorer prognosis for survival.
Topics: Animals; Bezoars; Colitis; Colon; Colonic Diseases; Horse Diseases; Horses; Infarction; Intestinal Obstruction; Postoperative Care; Prognosis
PubMed: 9290186
DOI: 10.1016/s0749-0739(17)30242-0 -
European Journal of Gastroenterology &... Jul 2020
Topics: Colon; Colonic Polyps; Humans; Polyps; Schistosomiasis
PubMed: 32472818
DOI: 10.1097/MEG.0000000000001727 -
World Journal of Gastroenterology Oct 2003Colonic diverticular disease (diverticulosis) is one of the most common gastrointestinal disorders in Western countries. This disorder is strictly related to aging and... (Review)
Review
Colonic diverticular disease (diverticulosis) is one of the most common gastrointestinal disorders in Western countries. This disorder is strictly related to aging and fibre intake, and still bears a discrete amount of morbidity. Numerous etiological co-factors have to date been implicated in the pathogenesis of the disease, yet the supporting evidence is still far from absolute. The present review considers the pathophysiology of colonic diverticular disease, with a special emphasis on factors related to abnormal colonic motility.
Topics: Colon; Diverticulosis, Colonic; Gastrointestinal Motility; Humans
PubMed: 14562365
DOI: 10.3748/wjg.v9.i10.2140 -
Alimentary Pharmacology & Therapeutics Jan 2008Butyrate, a short-chain fatty acid, is a main end-product of intestinal microbial fermentation of mainly dietary fibre. Butyrate is an important energy source for... (Review)
Review
BACKGROUND
Butyrate, a short-chain fatty acid, is a main end-product of intestinal microbial fermentation of mainly dietary fibre. Butyrate is an important energy source for intestinal epithelial cells and plays a role in the maintenance of colonic homeostasis.
AIM
To provide an overview on the present knowledge of the bioactivity of butyrate, emphasizing effects and possible mechanisms of action in relation to human colonic function.
METHODS
A PubMed search was performed to select relevant publications using the search terms: 'butyrate, short-chain fatty acid, fibre, colon, inflammation, carcinogenesis, barrier, oxidative stress, permeability and satiety'.
RESULTS
Butyrate exerts potent effects on a variety of colonic mucosal functions such as inhibition of inflammation and carcinogenesis, reinforcing various components of the colonic defence barrier and decreasing oxidative stress. In addition, butyrate may promote satiety. Two important mechanisms include the inhibition of nuclear factor kappa B activation and histone deacetylation. However, the observed effects of butyrate largely depend on concentrations and models used and human data are still limited.
CONCLUSION
Although most studies point towards beneficial effects of butyrate, more human in vivo studies are needed to contribute to our current understanding of butyrate-mediated effects on colonic function in health and disease.
Topics: Animals; Butyrates; Carbohydrate Metabolism; Child, Preschool; Colon; Colonic Neoplasms; Dietary Fiber; Enema; Fatty Acids, Volatile; Humans; Infant, Newborn; Inflammation; Intestinal Mucosa; Oxidative Stress; Rabbits; Rats; Satiation
PubMed: 17973645
DOI: 10.1111/j.1365-2036.2007.03562.x -
Nutrients Jan 2015Globally, zinc deficiency is widespread, despite decades of research highlighting its negative effects on health, and in particular upon child health in low-income... (Review)
Review
Globally, zinc deficiency is widespread, despite decades of research highlighting its negative effects on health, and in particular upon child health in low-income countries. Apart from inadequate dietary intake of bioavailable zinc, other significant contributors to zinc deficiency include the excessive intestinal loss of endogenously secreted zinc and impairment in small intestinal absorptive function. Such changes are likely to occur in children suffering from environmental (or tropical) enteropathy (EE)-an almost universal condition among inhabitants of developing countries characterized by morphologic and functional changes in the small intestine. Changes to the proximal gut in environmental enteropathy will likely influence the nature and amount of zinc delivered into the large intestine. Consequently, we reviewed the current literature to determine if colonic absorption of endogenous or exogenous (dietary) zinc could contribute to overall zinc nutriture. Whilst we found evidence that significant zinc absorption occurs in the rodent colon, and is favoured when microbially-fermentable carbohydrates (specifically resistant starch) are consumed, it is unclear whether this process occur in humans and/or to what degree. Constraints in study design in the few available studies may well have masked a possible colonic contribution to zinc nutrition. Furthermore these few available human studies have failed to include the actual target population that would benefit, namely infants affected by EE where zinc delivery to the colon may be increased and who are also at risk of zinc deficiency. In conducting this review we have not been able to confirm a colonic contribution to zinc absorption in humans. However, given the observations in rodents and that feeding resistant starch to children is feasible, definitive studies utilising the dual stable isotope method in children with EE should be undertaken.
Topics: 6-Phytase; Animals; Biological Availability; Colon; Homeostasis; Humans; Hydrolysis; Intestine, Small; Models, Animal; Phytic Acid; Zinc
PubMed: 25594440
DOI: 10.3390/nu7010572 -
Spectrochimica Acta. Part A, Molecular... Mar 2020A new large-area germanium ATR crystal is utilised with an FTIR microscope to improve the acquired images of de-paraffinized colon biopsy sections, without recourse to a...
A new large-area germanium ATR crystal is utilised with an FTIR microscope to improve the acquired images of de-paraffinized colon biopsy sections, without recourse to a synchrotron source. The large crystal (⌀ = 28 mm) offers significant improvements compared to slide-on small germanium crystal (⌀ = 3.5 mm); for example, it facilitates more uniform distribution of higher signal intensity within the field of view and more rapid acquisition time. Mapping of a larger sample area up to ca. 350 × 350 μm with this new set-up, coupled with imaging using an FPA detector, is demonstrated for the first time on biological specimens. The performance of k-means clustering algorithm applied to classify the different anatomical structures of the colon biopsies is greatly improved with mapping. Comparison of H&E stained adjacent tissue sections with false-colour k-means images strongly support differentiation of five distinct regions within tissues. The efficiency of the methodology to categorise colon tissues at various stages of malignancy is analysed via multivariate chemometrics. The second derivative spectra extracted from the crypt region of the colon were subjected to Partial Least Squares classification. Good separation between data in clusters occurs when projecting spectra on a PLS score plot on a plane made by the first 3 principal components. Important spectral biomarkers for colon malignancy classification were identified to exist mostly in the fingerprint region of the FTIR spectrum based on the chemometrics analysis.
Topics: Biomarkers, Tumor; Biopsy; Cluster Analysis; Colon; Colonic Neoplasms; Crystallization; Germanium; Humans; Least-Squares Analysis; Principal Component Analysis; Signal Processing, Computer-Assisted; Signal-To-Noise Ratio; Spectroscopy, Fourier Transform Infrared; Vibration
PubMed: 31753650
DOI: 10.1016/j.saa.2019.117695 -
Physiological Reviews Jul 2001Resistant starch (RS) is starch and products of its small intestinal digestion that enter the large bowel. It occurs for various reasons including chemical structure,... (Review)
Review
Resistant starch (RS) is starch and products of its small intestinal digestion that enter the large bowel. It occurs for various reasons including chemical structure, cooking of food, chemical modification, and food mastication. Human colonic bacteria ferment RS and nonstarch polysaccharides (NSP; major components of dietary fiber) to short-chain fatty acids (SCFA), mainly acetate, propionate, and butyrate. SCFA stimulate colonic blood flow and fluid and electrolyte uptake. Butyrate is a preferred substrate for colonocytes and appears to promote a normal phenotype in these cells. Fermentation of some RS types favors butyrate production. Measurement of colonic fermentation in humans is difficult, and indirect measures (e.g., fecal samples) or animal models have been used. Of the latter, rodents appear to be of limited value, and pigs or dogs are preferable. RS is less effective than NSP in stool bulking, but epidemiological data suggest that it is more protective against colorectal cancer, possibly via butyrate. RS is a prebiotic, but knowledge of its other interactions with the microflora is limited. The contribution of RS to fermentation and colonic physiology seems to be greater than that of NSP. However, the lack of a generally accepted analytical procedure that accommodates the major influences on RS means this is yet to be established.
Topics: Colon; Dietary Fiber; Digestion; Fatty Acids, Volatile; Fermentation; Humans; Intestinal Absorption; Intestine, Small; Polysaccharides; Starch
PubMed: 11427691
DOI: 10.1152/physrev.2001.81.3.1031