Small Bowel

2017 ◽  
Author(s):  
Vincent E Mortellaro

The small intestine is where multiple cell types combine to achieve the complex interaction between our bodies and ingested material from the outside world. As a highly specialized organ, the small intestine has a role in digestion, absorption of nutrients and electrolytes, and innate immunity to thwart exogenous pathogens and as host to a symbiotic environment where our immune system successfully interacts with a resident microbiome. This review covers the embryology, gross and microscopic anatomy, physiology of nutritional absorption, immune function, and advances in examining new discoveries in the interplay between the host and the resident microbiome. Key words: duodenum, ileum, jejunum, microbiota, midgut, migrating motor complex, nutritional absorption, villi

2017 ◽  
Author(s):  
Vincent E Mortellaro

The small intestine is where multiple cell types combine to achieve the complex interaction between our bodies and ingested material from the outside world. As a highly specialized organ, the small intestine has a role in digestion, absorption of nutrients and electrolytes, and innate immunity to thwart exogenous pathogens and as host to a symbiotic environment where our immune system successfully interacts with a resident microbiome. This review covers the embryology, gross and microscopic anatomy, physiology of nutritional absorption, immune function, and advances in examining new discoveries in the interplay between the host and the resident microbiome. Key words: duodenum, ileum, jejunum, microbiota, midgut, migrating motor complex, nutritional absorption, villi


2017 ◽  
Author(s):  
Eric A Schinnerer ◽  
Jayleen M Grams

This review focuses on the normal anatomy and physiology of the spleen. The spleen functions as a hematologic organ, filtering blood, metabolizing iron, and acting as a reservoir for blood cells. The spleen, the largest lymphatic organ, also plays a key role in adaptive and innate immunity.    This review contains 7 figures of highly rendered artwork and 26 references. Key words: immune system, spleen, spleen anatomy, spleen physiology, splenectomy vaccine guidelines


eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Jeff M Bernitz ◽  
Kateri A Moore

Multiple cell types that share a common origin cooperate to form a supportive niche for stem cells that give rise to blood and to the cells of the immune system.


Science ◽  
2017 ◽  
Vol 358 (6359) ◽  
pp. 58-63 ◽  
Author(s):  
Michael J. T. Stubbington ◽  
Orit Rozenblatt-Rosen ◽  
Aviv Regev ◽  
Sarah A. Teichmann

The immune system varies in cell types, states, and locations. The complex networks, interactions, and responses of immune cells produce diverse cellular ecosystems composed of multiple cell types, accompanied by genetic diversity in antigen receptors. Within this ecosystem, innate and adaptive immune cells maintain and protect tissue function, integrity, and homeostasis upon changes in functional demands and diverse insults. Characterizing this inherent complexity requires studies at single-cell resolution. Recent advances such as massively parallel single-cell RNA sequencing and sophisticated computational methods are catalyzing a revolution in our understanding of immunology. Here we provide an overview of the state of single-cell genomics methods and an outlook on the use of single-cell techniques to decipher the adaptive and innate components of immunity.


Vaccines ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 558
Author(s):  
Kali F. Crofts ◽  
Martha A. Alexander-Miller

The initial months of life reflect an extremely challenging time for newborns as a naïve immune system is bombarded with a large array of pathogens, commensals, and other foreign entities. In many instances, the immune response of young infants is dampened or altered, resulting in increased susceptibility and disease following infection. This is the result of both qualitative and quantitative changes in the response of multiple cell types across the immune system. Here we provide a review of the challenges associated with the newborn response to respiratory viral pathogens as well as the hurdles and advances for vaccine-mediated protection.


2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Rolf Spirig ◽  
Janice Tsui ◽  
Sidney Shaw

Cardiovascular disease is a complex disorder involving multiple pathophysiological processes, several of which involve activation of toll-like receptors (TLRs) of the innate immune system. As sentinels of innate immunity TLRs are nonclonally germline-encoded molecular pattern recognition receptors that recognize exogenous as well as tissue-derived molecular dangers signals promoting inflammation. In addition to their expression in immune cells, TLRs are found in other tissues and cell types including cardiomyocytes, endothelial and vascular smooth muscle cells. TLRs are differentially regulated in various cell types by several cardiovascular risk factors such as hypercholesterolemia, hyperlipidemia, and hyperglycemia and may represent a key mechanism linking chronic inflammation, cardiovascular disease progression, and activation of the immune system. Modulation of TLR signaling by specific TLR agonists or antagonists, alone or in combination, may be a useful therapeutic approach to treat various cardiovascular inflammatory conditions such as atherosclerosis, peripheral arterial disease, secondary microvascular complications of diabetes, autoimmune disease, and ischemia reperfusion injury. In this paper we discuss recent developments and current evidence for the role of TLR in cardiovascular disease as well as the therapeutic potential of various compounds on inhibition of TLR-mediated inflammatory responses.


2019 ◽  
Vol 317 (4) ◽  
pp. C737-C748
Author(s):  
Tiane Chen ◽  
Ruxian Lin ◽  
Leela Avula ◽  
Rafiquel Sarker ◽  
Jianbo Yang ◽  
...  

Enterotoxigenic Escherichia coli (ETEC) is a leading cause of childhood death from diarrhea and the leading cause of Traveler’s diarrhea. E. coli heat-stable enterotoxin (ST) is a major virulence factor of ETEC and inhibits the brush border Na/H exchanger NHE3 in producing diarrhea. NHE3 regulation involves multiprotein signaling complexes that form on its COOH terminus. In this study, the hypothesis was tested that ST signals via members of the Na/H exchanger regulatory factor (NHERF) family of scaffolding proteins, NHERF2, which had been previously shown to have a role, and now with concentration on a role for NHERF3. Two models were used: mouse small intestine and Caco-2/BBe cells. In both models, ST rapidly increased intracellular cGMP, inhibited NHE3 activity, and caused a quantitatively similar decrease in apical expression of NHE3. The transport effects were NHERF3 and NHERF2 dependent. Also, mutation of the COOH-terminal amino acids of NHERF3 supported that NHERF3-NHERF2 heterodimerization was likely to account for this dual dependence. The ST increase in cGMP in both models was partially dependent on NHERF3. The intracellular signaling pathways by which ST-cGMP inhibits NHE3 were different in mouse jejunum (activation of cGMP kinase II, cGKII) and Caco-2 cells, which do not express cGKII (elevation of intracellular Ca2+ concentration [Ca2+]i). The ST elevation of [Ca2+]i was from intracellular stores and was dependent on NHERF3-NHERF2. This study shows that intracellular signaling in the same diarrheal model in multiple cell types may be different; this has implications for therapeutic strategies, which often assume that models have similar signaling mechanisms.


2021 ◽  
Vol 15 ◽  
Author(s):  
Omar Mossad ◽  
Thomas Blank

The immune system is crucial for defending against various invaders, such as pathogens, cancer cells or misfolded proteins. With increasing age, the diminishing immune response, known as immunosenescence, becomes evident. Concomitantly, some diseases like infections, autoimmune diseases, chronic inflammatory diseases and cancer, accumulate with age. Different cell types are part of the innate immunity response and produce soluble factors, cytokines, chemokines, and type I interferons. Improper maturation of innate immune cells or their dysfunction have been linked to numerous age-related diseases. In parallel to the occurrence of the many functional facets of the immune response, a symbiotic microbiota had been acquired. For the relevant and situation-dependent function of the immune system the microbiome plays an essential role because it fine-tunes the immune system and its responses during life. Nevertheless, how the age-related alterations in the microbiota are reflected in the innate immune system, is still poorly understood. With this review, we provide an up-to-date overview on our present understanding of the gut microbiota effects on innate immunity, with a particular emphasis on aging-associated changes in the gut microbiota and the implications for the brain innate immune response.


Author(s):  
А.А. Коваленко ◽  
Г.П. Титова ◽  
В.К. Хугаева

Оперативное лечение различных заболеваний кишечника сопровождается осложнениями в виде нарушений микроциркуляции в области анастомоза кишки. Ранее нами показана способность лимфостимуляторов пептидной природы восстанавливать нарушенную микроциркуляцию, что послужило основой для настоящего исследования. Цель работы - оценка влияния стимуляции лимфотока в стенке кишки на процессы восстановления микроциркуляции, структуры и функции тонкой кишки в области оперативного вмешательства. Методика. В экспериментах на наркотизированных крысах (хлоралгидрат в дозе 0,6 г/кг в 0,9% растворе NaCl) моделировали различные поражения тонкой кишки (наложение лигатуры, перевязка 1-3 брыжеечных артерий, перекрут петли кишки вокруг оси брыжейки, сочетание нескольких видов повреждений). Резекция поврежденного участка через 1 сут. с последующим созданием тонкокишечного анастомоза завершалась орошением операционного поля раствором пептида-стимулятора лимфотока (40 мкг/кг массы животного в 1 мл 0,9% раствора NaCl). На 7-е сут. после операции проводили гистологическое исследование фрагмента кишки в области анастомоза. Результаты. На 7-е сут. после резекции у выживших животных (летальность вследствие кишечной непроходимости составляла 30%) имеют место морфологические признаки острых сосудистых нарушений стенки кишки, изменений кровеносных и лимфатических микрососудов, интерстициальный отек всех слоев стенки кишки, дилатация просвета кишки, повреждение всасывающего эпителия ворсин с истончением щеточной каемки клеток, морфологические признаки гиперфункции бокаловидных клеток. Использование лимфостимулятора пептидной природы после операции увеличивало выживаемость животных на 24%. У части животных отмечалось уменьшение расширения просвета кишки, у других практически полная его нормализация. Восстанавливалась форма кишечных ворсин и распределение бокаловидных клеток. Отсутствовали признаки внутриклеточного и межмышечного отека. Отмечено умеренное полнокровие венул. Заключение. Использование лимфостимулятора при хирургическом лечении кишечной непроходимости увеличивает выживаемость животных на 24% по сравнению с контролем, способствует более раннему восстановлению структуры и функции тонкой кишки. Полученные результаты свидетельствуют о перспективности использования стимуляции лимфотока при операциях на кишечнике. Surgical treatment of bowel diseases is associated with complications that cause microcirculatory disturbances in the anastomosis area and may lead to a fatal outcome. This study was based on our previous finding that peptide-type lymphatic stimulators are able to restore impaired microcirculation. The aim of this work was stimulating the lymph flow in the intestinal wall to facilitate recovery of microcirculation, structure and function of the small intestine in the area of surgical intervention. Methods. In experiments on anesthetized rats (0.6 g/kg chloral hydrate in 0.9% NaCl), various small bowel lesions were modeled (bowel ligation, ligation of 1-3 mesenteric arteries, gut torsion, combination of several lesion types). In 24 h, the damaged area was resected, and a small intestine anastomosis was creased. The surgery was completed with irrigation of the operative field with a solution of lymph flow stimulating peptide (40 мg/kg body weight in 1 ml of 0.9% NaCl). A gut fragment from the anastomosis area was examined histologically on day 7 after the surgery. Results. On the 7th day after removing the intestinal obstruction, the surviving animals (lethality 30%) had morphological signs of acute vascular disorders in the intestinal wall; changes in blood and lymphatic microvessels; interstitial edema of all intestinal wall layers; dilatation of the intestinal lumen; damage to the absorptive epithelium of villi with thinning of the brush border, and hyperfunction of mucous (goblet) cells. The use of the peptide after surgery increased the survival rate of animals by 24% and provided a smaller dilatation of the intestinal lumen in some animals. In other animals, the lumen recovered. The shape of intestinal villi and distribution of goblet cells were restored. Signs of intracellular and intermuscular edema were absent. Moderate venular congestion was noticed. Conclusion. Using the lymphatic stimulator in surgical treatment of intestinal obstruction increases the survival rate of animals by 24% compared to the control, facilitates earlier restoration of the small intestine structure and function. The obtained results indicated the effectiveness of lymphatic stimulation in intestinal surgery.


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