Intestinal Lymph Research Articles

Incidence of Mycobacterium avium Subsp. paratuberculosis (MAP) Infection in slaughtered buffaloes (Bubalus bubalis) of Malwa Region of Madhya Pradesh

The study was undertaken to assess the incidence of subclinical and clinical paratuberculosis in slaughtered buffaloes of Malwa region of Madhya Pradesh. They were unproductive buffaloes (1- 10 years old) slaughtered in Mhow and Indore examined for subclinical and clinical Mycobacterium avium subsp. paratuberculosis (MAP) infection. Study of gross lesions of intestine and respective mesenteric lymph nodes (MLNs) showed overall 87.33% (131/150) incidence of paratuberculosis. Out of these 131 cases of paratuberculosis, 18.21% (24/131) buffaloes suffered from subclinical and 81.68% (107/131) from clinical paratuberculosis, whereas impression smear examination revealed clinical and subclinical paratuberculosis up to 25.77 and 74.33% in intestine and 13.51 and 86.49% in MLNs, respectively.

Sepsis-induced multi-organ dysfunction syndrome—a mechanistic approach

Sepsis-associated mortality is highly related to the development of the multi-organ dysfunction syndrome (MODS). MODS represents a virulent and often incremental assault on virtually all organ systems. Interestingly, the pathogenetic mechanisms that underlie MODS in sepsis are complex and not entirely elucidated. Most implicated molecular culprits are overshooting of the host immune response to the infectious trigger, endothelial cell activation and glycocalyx destruction, alterations at the mitochondrial level, and uncontrolled apoptosis. In addition, microcirculatory dysfunction characterized by perfusion heterogeneity, thrombosis, and intravascular blood cell clogging significantly decreases tissue oxygen delivery. In the background, the gut may continuously fuel MODS by sustaining systemic inflammatory processes either by propagating transmural bacterial translocation or by shedding inflammatory molecules through the intestinal lymph system. From a holistic viewpoint, all proposed pathways leading to sepsis-induced MODS probably are closely intertwined which renders a single therapeutic approach for sepsis-induced MODS irrelevant.

Bilateral Chylothorax Secondary to Cirrhosis and Chylous Ascites

SESSION TITLE: Disorders of the Pleura SESSION TYPE: Affiliate Case Report Poster PRESENTED ON: Tuesday, October 31, 2017 at 01:30 PM - 02:30 PM INTRODUCTION: Chylothorax is commonly caused by injury or obstruction of the thoracic duct within the thorax. Rarely, chylothorax can occur as a manifestation of decompensated liver disease with chylous ascites. CASE PRESENTATION: A 61 year old male with decompensated alcoholic liver disease was hospitalized for progressive dyspnea and abdominal distension. Physical examination and radiographic imaging identified large, bilateral pleural effusions and ascites. He did not respond to diuresis and therapeutic paracentesis, so bilateral thoracentesis was performed. Gross appearance of the bilateral pleural fluid was milky and amber in color, contrary to the expected appearance seen with transudative hepatic hydrothorax. Pleural fluid analysis was consistent with bilateral exudative chylothorax (triglycerides of 183 mg/dl and 197 mg/dl from the right and left, respectively). Pleural fluid to serum triglyceride ratio was 4.925 and cholesterol ratio was 0.333, definitively characterizing the pleural fluid as chyle. Although basic initial ascites fluid studies were consistent with portal hypertension as the mechanism, retrospective analysis was consistent with chylous ascites (triglycerides 148 mg/dl). Based on a MELD-Na of 26 and lack of responsiveness with aggressive medical management including diuretics, dietary modification, and abstinence from alcohol, the patient was referred for liver transplantation. DISCUSSION: The mechanism for chylothorax secondary to cirrhosis is due to portal hypertension causing rupture of small lymphatics and leakage of whole intestinal lymph into ascitic fluid, which then passes through diaphragmatic recesses. This mechanism is akin to the more commonly encountered hepatic hydrothorax which is typically transudative in nature. Management of chylothorax resulting from decompensated liver disease is similar to that of hepatic hydrothorax, although there are some additional considerations including use of octreotide to decrease lymphatic flow and post-prandial triglycerides, bowel rest with TPN, and use of orlistat. Medium-chain triglyceride supplementation, used in post-surgical chylous ascites, leads to increased hepatic encephalopathy and death in cirrhotic patients. CONCLUSIONS: For patients with cirrhosis, ascites, and pleural effusions, thoracentesis with thorough pleural fluid analysis can lead to accurate diagnosis of chylothorax, leading to appropriate identification and treatment. When suspected in patients with cirrhosis and ascites, pleural fluid studies should include triglycerides, cholesterol, and chylomicrons, in addition to serum cholesterol and triglycerides to allow for accurate recognition of chylothorax and the underlying etiology. Reference #1: Doerr, CH. “Etiology of Chylothorax in 203 Patients.” Mayo Clin Proc 80.7 (2005): 867-70. Print. Reference #2: Romero, S, and C Martin. “Chylothorax in Cirrhosis of the Liver: Analysis of Its Frequency and Clinical Characteristics.” Chest 114.1 (July 1998): 154-59. Print. DISCLOSURE: The following authors have nothing to disclose: Mark Nau, David Ferraro No Product/Research Disclosure Information

Pharmacokinetic and Toxicodynamic Characterization of a Novel Doxorubicin Derivative.

Doxorubicin (Dox) is an effective anti-cancer medication with poor oral bioavailability and systemic toxicities. DoxQ was developed by conjugating Dox to the lymphatically absorbed antioxidant quercetin to improve Dox’s bioavailability and tolerability. The purpose of this study was to characterize the pharmacokinetics and safety of Dox after intravenous (IV) and oral (PO) administration of DoxQ or Dox (10 mg/kg) and investigate the intestinal lymphatic delivery of Dox after PO DoxQ administration in male Sprague–Dawley rats. Drug concentrations in serum, urine, and lymph were quantified by HPLC with fluorescence detection. DoxQ intact IV showed a 5-fold increase in the area under the curve (AUC)—18.6 ± 1.98 compared to 3.97 ± 0.71 μg * h/mL after Dox—and a significant reduction in the volume of distribution (Vss): 0.138 ± 0.015 versus 6.35 ± 1.06 L/kg. The fraction excreted unchanged in urine (fe) of IV DoxQ and Dox was ~5% and ~11%, respectively. Cumulative amounts of Dox in the mesenteric lymph fluid after oral DoxQ were twice as high as Dox in a mesenteric lymph duct cannulation rat model. Oral DoxQ increased AUC of Dox by ~1.5-fold compared to after oral Dox. Concentrations of β-N-Acetylglucosaminidase (NAG) but not cardiac troponin (cTnI) were lower after IV DoxQ than Dox. DoxQ altered the pharmacokinetic disposition of Dox, improved its renal safety and oral bioavailability, and is in part transported through intestinal lymphatics.

Review article: the diagnostic approach and current management of chylous ascites.

Chylous ascites is rare, accounting for less than 1% of cases. An appropriate and stepwise approach to its diagnosis and management is of key importance. To review the current diagnostic approach and management of chylous ascites. A literature search was conducted using PubMed using the key words 'chylous', 'ascites', 'cirrhosis', 'pathophysiology', 'nutritional therapy', 'paracentesis", "transjugular intrahepatic portosystemic shunt" and "TIPSS'. Only articles in English were included. Chylous ascites is caused by the traumatic or obstructive disruption of the lymphatic system that leads to extravasation of thoracic or intestinal lymph into the abdominal space and the accumulation of a milky fluid rich in triglycerides. The most common causes are malignancy, cirrhosis and trauma after abdominal surgery. This condition can lead to chyle depletion, which results in nutritional, immunologic and metabolic deficiencies. An ascitic triglyceride concentration above 200mg/dL is consistent with chylous ascites. Treatment is based on management of the underlying cause and nutritional support. Chylous ascites is mostly due to malignancy and cirrhosis in adults, and congenital lymphatic disorders in children. Treatment with nutritional optimization and management of the underlying etiology are the cornerstones of therapy. When conservative measures fail, other interventions such as octreotide/somatostatin analogues, surgical ligation, embolization and transjugular intrahepatic portosystemic shunt in patients with cirrhosis can be considered.

Scintigraphic History of Arthritis in Whipple’s Disease

The article describes a year clinical observation of a year old male with Whipple s disease The diagnosis was established based on the progressive diarrhea with malabsorbtion detection by CT a low density retroperitoneal infiltrate and mesenterial lymphadenopathy abundant PAS positive macrophages in the biopsy specimens of the small intestine and mesenterial lymph nodes Arthropathy had started years before the appearance of intestinal symptoms regressed with its development and resumed when clinical remission was achieved

Intestinal lymphatic vasculature: structure, mechanisms and functions.

The mammalian intestine is richly supplied with lymphatic vasculature, which has functions ranging from maintenance of interstitial fluid balance to transport of antigens, antigen-presenting cells, dietary lipids and fat-soluble vitamins. In this Review, we provide in-depth information concerning the organization and structure of intestinal lymphatics, the current view of their developmental origins, as well as molecular mechanisms of intestinal lymphatic patterning and maintenance. We will also discuss physiological aspects of intestinal lymph flow regulation and the known and emerging roles of intestinal lymphatic vessels in human diseases, such as IBD, infection and cancer.

Progress of the application of optical coherence tomography in gastrointestinal tumor surgery

Optical coherence tomography (OCT) is a real-time, cross-sectional optical imaging technology. It is analogous to ultrasonography, except that OCT uses light waves instead of sound waves, and can provide three-dimensional morphological images of living tissues with a micrometer resolution. Through the use of endoscopes, needles, catheters and laparoscopes, OCT has demonstrated tremendous imaging potential in tumor surgery. The current studies suggest that OCT has potential for clinical applications in the following fields of gastrointestinal tumor surgery: (1) Early tumor detection and diagnosis: OCT can distinguish differences between polyp tissue, normal tissue and malignant tissue. It could possibly identify premalignant lesions or conditions potentially predisposing to malignancy, such as gastric and intestinal metaplasia, gastritis associated with Helicobacter pylori, and early gastric cancer involving the mucosa or submucosa. In addition, OCT can differentiate between adenomatous polyps and hyperplastic polyps. (2) Optical biopsy of lymph nodes: As a high-resolution, near-IR imaging modality, OCT is capable of visualizing microscopic features within tissue, distinguishing lymph node tissue from surrounding adipose tissue, revealing nodal structures such as germinal centers and intra-nodal vessels. Consequently, OCT has the ability to show changes in node microarchitecture during metastatic tumor infiltration. (3) Intraoperative guidance for real-time determination of surgical margins: In other tumors such as oral squamous cell carcinoma and breast cancer, it has been demonstrated that OCT can be used to rapidly scan large areas of tissue, to guide at the cellular level the surgical resection of neoplastic disease, and to scan tumor margins for the presence of residual disease, tumor foci, and potentially even metastasizing tumor cells. It implies that colorectal neoplasms surgeons can possibly use the laparoscopic OCT to detect the intestinal tumor margin and lymph nodes during operation in the future, so as to determine the appropriate range of bowel resection and lymph node dissection. At present, there are few reports about the intra-operative application of OCT in the field of gastrointestinal tumor surgery. Thus there is a tremendous opportunity for further research in this field.

Value of CT lymphangiography combined with direct lymphangiography in diagnosing primary intestinal lymphangiectasia

Objective To investigate the clinical value of CT lymphangiography (CTL) combined with direct lymphangiography (DLG) in primary intestinal lymphangiectasia (PIL). Methods Sixteen patients diagnosed as PIL with intestinal enteroscopy were recruited in this retrospective study. All the patients were performed DLG and CTL one week before exploratory laparotomy. Subjective assessment in DLG included weak lymphatic fluid drainage, lymphangiectasia, lymphatic reflux, fistula and thoracic outlet reflux or obstruction. While for CTL combined with DLG, the intestinal and extra-intestinal lesions were evaluated, including lymph node, edema, lymphangiectasia and abnormal distribution, fistula, and lymphangiomatosis. All the diagnosis was compared with intestinal endoscopy results. Results For DLG, 16 weak lymphatic fluid drainages, 9 lymphangiectasia, 1 fistula with abdomen and 14 thoracic outlets weak lymphatic fluid drainage or obstruction were found. For DLG combined with CTL, 16 intestinal lumens dilatation and 14 circumferential intestinal thickening were found in intestinal lesions. While for extra-intestinal lesions, the imaging features included edematous findings (12 in mesentery, 7 ascites only, 2 hydrothorax and ascites, and 3 pericardial, thoracic and abdominal effusions), abdominal lymph nodes (6 cases), lymphangiectasia and abnormal distributions (14 cases), fistulas (lymph-intestinal luminal fistula in 4 cases, and lymph-abdominal fistula in 3 cases), lymphangiomatosis (3 cases), and thoracic duct outlet dysfunction and reflux (14 cases).The number of cases diagnosed as intestinal lymphangiectasia, intestinal luminal lymph exudation and lymph fistula were 16, 10 and 6 with intestinal endoscopy, while the number were 11, 0, and 4 with CTL combination with DLG. Conclusion Combination of CTL with DLG is valuable in the diagnosis of PIL. Key words: Lymphangiectasis, intestinal; Tomography,X-ray computed; Lymphography; Endoscopy, digestive system

The differentiation and maintenance of RORγt+ Tregs respectively require integrin αvβ8 expression by dendritic cells and commensal microbiota

Abstract The generation of RORγt+ regulatory T cells (Tregs), which regulate type 2 immune respond, is dependent on dendritic cells and microbiota, but mechanisms are poorly understood. Here we show that the differentiation of RORγt+ Tregs was critically dependented on integrin αvβ8 expressed in DCs. In mice, lack of αvβ8 in DCs resulted in loss of RORγt+ Tregs in the small intestine and mesenteric lymph nodes. Moreover, we also report that the maintenance of RORγt+ Tregs needs the existence of commensal bacteria but not DCs in small intestine. The percentage and the proliferation of RORγt+ Tregs were decreased after treated with antibiotic while these were unaffected by the absence of DCs in a short time. These date demonstrate that αvβ8 expressed in small intestinal DCs play a critical role in the induction of RORγt+ Tregs and microbiota act as a key factor on maintenance of RORγt+ Tregs, respectively. Our results may help to explain the mechanisms of oral tolerance via αvβ8 in DCs and commensal microbiota regulate the generation of RORγt+ Tregs to suppress type 2 immune respond.

Effect of dietary fatty acid and micronutrient intake/energy ratio on serum diamine oxidase activity in healthy women.

Serum diamine oxidase (DAO) activity varies to a greater extent in women than in men. DAO activity during the luteal phase was higher than that during the follicular phase in healthy women. Recent reports have indicated that duodenal lipid infusion increased DAO activity in the intestinal lymph in rats. The aim of this study was to elucidate the effect of dietary nutrient intake on serum DAO activity in healthy women. Thirty-four healthy Japanese women were recruited. Food surveys were performed using dietary records for 3d during both the follicular and luteal phases. Nutrient intake was calculated and expressed as the energy intake ratio. The correlation between DAO activity and nutrient intake was analyzed. Serum DAO activity in both phases was positively correlated with intake of long-chain fatty acids, saturated fatty acids, and monounsaturated fatty acids (P<0.05). Intake of phosphorus, calcium, zinc, magnesium, iron, and vitamin B12 during the luteal phase was positively correlated with serum DAO activity (P<0.05). In healthy women, serum DAO activity was influenced by dietary fatty acid and micronutrient intake.

A method of establishing orthotopic transplantable hepatocellular carcinoma in mice

Objective To establish a method for preparing orthotropic transplantable hepatocellular carcinoma in mice. Methods According to the liver detailed anatomical structure of the mouse, 50 μl mouse ascites containing 1×106 and 5×105 mouse hematoma H22 cells was input to liver in 12 Kunming mice through percutaneous intraperitoneal injection by syringe, respectively, to establish orthotopic transplantable hepatocellular carcinoma model. The growth status of mice was observed, and the pathological changes of liver and tumor metastasis tissues were detected. The tumor formation and metastasis were analyzed. Results The tumor formation rate was 100% (12/12) by direct injection of mouse hematoma H22 cells in 2 groups. The inoculated mice started to appear ascites at the 6th day, and all mice produced ascites at the 10th day. The survival time was (16.17±3.07) d and (18.08±3.34) d in 1×106 group and 5×105 group, respectively. Some mice emerged tumor metastasis in kidney, intestine, spleen and mesenteric lymph nodes. Conclusion The method of direct injection could establish orthotropic transplantable hepatocellular carcinoma model in mice, which can be used for antitumor drug research. Key words: Liver neoplasms; Orthotopic transplantion tumor; Models, animal

Intestinal Mononuclear Phagocytes in Health and Disease.

The intestine is the tissue of the body with the highest constitutive exposure to foreign antigen and is also a common entry portal for many local and systemic pathogens. Therefore, the local immune system has the unenviable task of balancing efficient responses to dangerous pathogens with tolerance toward beneficial microbiota and food antigens. As in most tissues, the decision between tolerance and immunity is critically governed by the activity of local myeloid cells. However, the unique challenges posed by the intestinal environment have necessitated the development of several specialized mononuclear phagocyte populations with distinct phenotypic and functional characteristics that have vital roles in maintaining barrier function and immune homeostasis in the intestine. Intestinal mononuclear phagocyte populations, comprising dendritic cells and macrophages, are crucial for raising appropriate active immune responses against ingested pathogens. Recent technical advances, including microsurgical approaches allowing collection of cells migrating in intestinal lymph, intravital microscopy, and novel gene-targeting approaches, have led to clearer distinctions between mononuclear phagocyte populations in intestinal tissue. In this review, we present an overview of the various subpopulations of intestinal mononuclear phagocytes and discuss their phenotypic and functional characteristics. We also outline their roles in host protection from infection and their regulatory functions in maintaining immune tolerance toward beneficial intestinal antigens.

BACTERIAL MICROBIOTA IN HARBOR SEALS (PHOCA VITULINA) FROM THE NORTH SEA OF SCHLESWIG-HOLSTEIN, GERMANY, AROUND THE TIME OF MORBILLIVIRUS AND INFLUENZA EPIDEMICS

We present microbiologic findings in harbor seal (phoca; Phoca vitulina ) carcasses collected from the North Sea of Schleswig-Holstein, Germany, 1996-2014, and interpret results in relation to potential variations caused by phocine distemper virus and influenza A virus mass mortalities. We conducted microbiologic investigations on 2,124 tissue samples from lung, liver, kidney, spleen, intestine, and mesenteric lymph nodes from 549 dead harbor seals of the German North Sea. A large variety of bacteria, including potentially pathogenic species such as Bordetella bronchiseptica , Brucella spp., Clostridium perfringens , Escherichia coli , Erysipelothrix rhusiopathiae , β-hemolytic streptococci, and Staphylococcus aureus , were isolated. These bacteria were associated with bronchopneumonia, gastroenteritis, hepatitis, polyarthritis, nephritis, myositis, myocarditis, and septicemia. Bordetella bronchiseptica and Streptococcus equi subsp. zooepidemicus were significantly associated with the seal die-offs from phocine distemper in 2002 and influenza in 2014. Many bacteria were detected in tissues of dead harbor seals, of which E. coli , β-hemolytic streptococci, and Brucella spp. might be responsible for pathologic changes. Zoonotic bacteria such as Brucella spp. and E. rhusiopathiae are frequently isolated from harbor seals. Brucella spp. was less and Vibrio spp. more frequently found in summer. Erysipelothrix rhusiopathiae showed an almost regular 4-yr oscillating trend. We found C. perfringens less frequently and E. coli more frequently in harbor seals from St. Peter-Ording. Because zoonotic bacteria are regularly found, handling of dead and live harbor seal specimens should be conducted carefully to prevent transmission to humans. Further investigations are needed to understand microbiota changes in relation to increasing seal populations, reintroduction of rehabilitated seals to the wild, and increasing pressure from anthropogenic activities.

Molecular characterization and expression analysis of the NLR family CARD containing five transcripts in the pig.

The NOD-like receptor (NLR) family caspase recruitment domain-containing 5 (NLRC5) is one of the newly discovered and largest NLR family members. The NLRC5 has recently received extensive attention because of its important role in regulating innate and adaptive immune responses. The NLRC5 in many vertebrates, such as humans, mice, cattle, and horses, has already been proven and studied. However, the NLRC5 gene characteristics of pigs remain unclear. Thus, we completely cloned the NLRC5 cDNA sequence of the pig using the rapid amplification of cDNA ends(RACE) technology. A characteristic and tissue expression analysis was also conducted on the pig sequence. The sequence analysis showed that the complete cDNA sequence of the NLRC5 of the pig is 6638 bp, and the open reading frame is 5538 bp which encoded 1846 amino acids. The protein prediction analysis indicates that the overall performance of the NLRC5 protein of the pig is hydrophilic and possesses a typical nucleotide binding and oligomerization domain(NBD) and 20 leucine-rich repeats(LRRs). The homology analysis result indicates that the NLRC5 transcript in pigs is highly homologous to cattle, sheep, macaques, and humans, and accounts for around 80%. The genetic evolutionary tree analysis shows that the NLRC5 transcript in pigs has the closest evolutionary relationship with cattle and sheep. Further tissue expression analysis shows that immune organ systems (e.g., lymph node and spleen) and mucosa organs (e.g., intestinal lymph node, stomach, and lungs) possess high expressions with NLRC5 mRNA. The result of this study indicates that the NLRC5 transcript in pigs is relatively conservative among mammals and may play a vital role in immune reaction, which provides a basis for further studies on the NLRC5 function in the pig immune system and the role in comparative immunity.

ГІСТОЛОГІЧНІ ЗМІНИ В ТЕЛЯТ ЗА ГОСТРОГО ПЕРЕБІГУ САЛЬМОНЕЛЬОЗУ

The results of study of histological changes in calves by age of 20 – 40 days at acute salmonellosis infection are presented. At a histological research the most expressed changes were registered in the liver, thin intestine and lymphoid organs that contingently reproduction here of the causative agent. At acute form of salmonellosis in calves of this age-grade characteristic histological changes include: submilliar, intralobular, coagulativ, areactive foci of necrosis in a liver; cell granuloma in a liver; the acute diffusive serous-catarrhal enteritis with a hemorrhagic accent; serous lymphadenitis of intestinal lymph nodes; the acute diffusive catarrhal abomasitis. Also nonspecific, but constant morphological signs of salmonellosis are hyperplasia Peyer’s patches of a small intestine, intestinal lymph nodes, spleen and dystrophic changes of parenchymal organs.An analysis and theoretical ground of pathogenetic mechanisms of the educed microstructural changes are conducted. It is shown that in pathogenesis of salmonellosis an important role is played bacteriaemia and toxinaemia, which result to the defeat of endothelia of vessels and blood cells with subsequent violation of mechanisms of haemostasis гand development of the infectiously-toxic shock.

Glyceride‐Mimetic Prodrugs Incorporating Self‐Immolative Spacers Promote Lymphatic Transport, Avoid First‐Pass Metabolism, and Enhance Oral Bioavailability

AbstractFirst‐pass hepatic metabolism can significantly limit oral drug bioavailability. Drug transport from the intestine through the lymphatic system, rather than the portal vein, circumvents first‐pass metabolism. However, the majority of drugs do not have the requisite physicochemical properties to facilitate lymphatic access. Herein, we describe a prodrug strategy that promotes selective transport through the intestinal lymph vessels and subsequent release of drug in the systemic circulation, thereby enhancing oral bioavailability. Using testosterone (TST) as a model high first‐pass drug, glyceride‐mimetic prodrugs incorporating self‐immolative (SI) spacers, resulted in remarkable increases (up to 90‐fold) in TST plasma exposure when compared to the current commercial product testosterone undecanoate (TU). This approach opens new opportunities for the effective development of drugs where oral delivery is limited by first‐pass metabolism and provides a new avenue to enhance drug targeting to intestinal lymphoid tissue.

Glyceride-Mimetic Prodrugs Incorporating Self-Immolative Spacers Promote Lymphatic Transport, Avoid First-Pass Metabolism, and Enhance Oral Bioavailability.

First-pass hepatic metabolism can significantly limit oral drug bioavailability. Drug transport from the intestine through the lymphatic system, rather than the portal vein, circumvents first-pass metabolism. However, the majority of drugs do not have the requisite physicochemical properties to facilitate lymphatic access. Herein, we describe a prodrug strategy that promotes selective transport through the intestinal lymph vessels and subsequent release of drug in the systemic circulation, thereby enhancing oral bioavailability. Using testosterone (TST) as a model high first-pass drug, glyceride-mimetic prodrugs incorporating self-immolative (SI) spacers, resulted in remarkable increases (up to 90-fold) in TST plasma exposure when compared to the current commercial product testosterone undecanoate (TU). This approach opens new opportunities for the effective development of drugs where oral delivery is limited by first-pass metabolism and provides a new avenue to enhance drug targeting to intestinal lymphoid tissue.

Antibiotics Suppress Activation of Intestinal Mucosal Mast Cells and Reduce Dietary Lipid Absorption in Sprague-Dawley Rats

The gut microbiota affects intestinal permeability and mucosal mast cells (MMCs) responses. Activation of MMCs has been associated with absorption of dietary fat. We investigated whether the gut microbiota contributes to the fat-induced activation of MMCs in rats, and how antibiotics might affect this process. Adult male Sprague-Dawley rats were given streptomycin and penicillin for 4 days (n= 6-8) to reduce the abundance of their gut flora, or normal drinking water (controls, n= 6-8). They underwent lymph fistula surgery and after an overnight recovery were given an intraduodenal bolus of intralipid. We collected intestinal tissues and lymph fluid and assessed activation of MMCs, intestinal permeability, and fat transport parameters. Compared with controls, intestinal lymph from rats given antibiotics had reduced levels of mucosal mast cell protease II (produced by MMCs) and decreased activity of diamine oxidase (produced by enterocytes) (P < .05). Rats given antibiotics had reduced intestinal permeability in response to dietary lipid compared with controls (P < .01). Unexpectedly, antibiotics also reduced lymphatic transport of triacylglycerol and phospholipid (P < .01), concomitant with decreased levels of mucosal apolipoproteins B, A-I, and A-IV (P < .01). No differences were found in intestinal motility or luminal pancreatic lipase activity between rats given antibiotics and controls. These effects were not seen with an acute dose of antibiotics or 4 weeks after the antibiotic regimen ended. The intestinal microbiota appears to activate MMCs after the ingestion of fat in rats; this contributes to fat-induced intestinal permeability. We found that the gut microbiome promotes absorption of lipid, probably by intestinal production of apolipoproteins and secretion of chylomicrons.

Abstract 835: Comparison of direct transplantation of colon cancer cells vs. tumor xenografts using orthotopic mouse model for colon cancer progression and metastasis

Abstract Orthotopic transplantation is the process of implantation of cancer cells or tumor xenograft tissues into the organ of origin of the cancer. This procedure enables cells to grow and proliferate in their natural microenvironment. The orthotopic transplantation model has been observed to be highly amenable to cancer cells and recapitulates the human disease with high fidelity. Orthotopic transplantation is very common in clinical cancer research using athymic nude mouse as a model system. A major advantage of the orthotopic transplantation model is its ability to study the development and progression of cancer metastasis. The identification and therapeutic validation of anti-metastatic agents is of urgent need since till date there are no effective anti-metastatic therapies available for colon cancer. The procedure of xenograft transplant is time consuming and costly because of the involvement of more number of mice. Popular method for orthotopic transplant is to grow a subcutaneous tumor injecting human cancer cells and then transplant a small piece of xenograft to the immune deficient mouse for clinical study. In this study, we directly injected the tumor cells below the sub-serosal layer of the caecum to develop colorectal cancer bypassing the formation of xenograft and its subsequent transplantation. We compared the effectiveness in tumor progression and metastasis between the cell transplant and xenograft implant to the caecum. GFP labelled HCT116 cells were used for this study to develop colorectal cancer. First, we injected 8 million cells subcutaneously to the athymic nude mice to generate xenograft for further transplant to the caecum. On another set of experimental animals, a total of 2 million cells were directly injected below the sub-serosal membrane to develop primary tumor on the colon. Whole body GFP imaging revealed that within a week of transplantation of cancer cells or xenografts, primary tumor starts to develop to the colon and metastasized within 4-5 weeks after implantation. In both the cases, we record a 100% of primary tumor formation with 50-60% liver and 75-80% lung metastasis. To confirm the metastasis in liver and lung we studied GAPDH expression on the tissues and conduct H&amp;E /immunofluorescence staining. Whole body or organ GFP imaging also reveals that pancreas, kidney and associated intestinal lymph glands are severely affected by both the orthotopic transplantation methods. In conclusion, direct sub-serosal injection of cells to develop colorectal cancer primary and metastatic deposits is cost effective and time saving and thus seems to potentially have an advantage over xenograft transplant method. Citation Format: Anathbandhu Chaudhuri, Liying Geng, Jing Wang. Comparison of direct transplantation of colon cancer cells vs. tumor xenografts using orthotopic mouse model for colon cancer progression and metastasis. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 835.