M. Noguchi

Effects of Adding Butyric Acid to PN on Gut-Associated Lymphoid Tissue and Mucosal Immunoglobulin A Levels

BACKGROUNDnParenteral nutrition (PN) causes intestinal mucosal atrophy, gut-associated lymphoid tissue (GALT) atrophy and dysfunction, leading to impaired mucosal immunity and increased susceptibility to infectious complications. Therefore, new PN formulations are needed to maintain mucosal immunity. Short-chain fatty acids have been demonstrated to exert beneficial effects on the intestinal mucosa. We examined the effects of adding butyric acid to PN on GALT lymphocyte numbers, phenotypes, mucosal immunoglobulin A (IgA) levels, and intestinal morphology in mice.nnnMETHODSnMale Institute of Cancer Research mice (n = 103) were randomized to receive either standard PN (S-PN), butyric acid-supplemented PN (Bu-PN), or ad libitum chow (control) groups. The mice were fed these respective diets for 5 days. In experiment 1, cells were isolated from Peyers patches (PPs) to determine lymphocyte numbers and phenotypes (αβTCR(+), γδTCR(+), CD4(+), CD8(+), B220(+) cells). IgA levels in small intestinal washings were also measured. In experiment 2, IgA levels in respiratory tract (bronchoalveolar and nasal) washings were measured. In experiment 3, small intestinal morphology was evaluated.nnnRESULTSnLymphocyte yields from PPs and small intestinal, bronchoalveolar, and nasal washing IgA levels were all significantly lower in the S-PN group than in the control group. Bu-PN moderately, but significantly, restored PP lymphocyte numbers, as well as intestinal and bronchoalveolar IgA levels, as compared with S-PN. Villous height and crypt depth in the small intestine were significantly decreased in the S-PN group vs the control group, however Bu-PN restored intestinal morphology.nnnCONCLUSIONSnA new PN formula containing butyric acid is feasible and would ameliorate PN-induced impairment of mucosal immunity.

Enteral nutrition rapidly reverses total parenteral nutrition-induced impairment of hepatic immunity in a murine model

BACKGROUND & AIMSnTotal parenteral nutrition (TPN) impairs host immunocompetence, a mechanism possibly underlying the high morbidity of infectious complications in critically ill patients. Our recent study demonstrated TPN to reduce the number and function of hepatic mononuclear cells (MNCs) and to worsen survival after intraportal Pseudomonas challenge in mice. The present study examined the duration of enteral nutrition (EN) needed to reverse TPN-induced changes in hepatic MNCs in a murine model.nnnMETHODSnMale ICR mice (6 weeks) received 5 days of TPN followed by 0 (TPN), 12 (EN12), 24 (EN24), 48 (EN48) or 72 (EN72)h of chow feeding. Control mice (Control) were given chow with intravenous saline infusions for 5 days. After nutritional support, hepatic MNCs were isolated and counted. Lipopolysaccharide (LPS) receptor expressions (CD14 and TLR4/MD2) on Kupffer cells were analyzed by flowcytometry. In addition, TPN, EN12, EN48 and control mice were given intraportal Pseudomonas challenge and survival was monitored.nnnRESULTSnThe TPN group was significantly lower in hepatic MNC number and LPS receptor expressions than the Control group. However, EN quickly reversed TPN-induced hepatic impairments in MNC loss within 12h, CD14 expression within 48 h and TLR4/MD2 expression within 24h. Survival of the EN48 group was significantly improved as compared with the TPN and EN12 groups.nnnCONCLUSIONSnEN rapidly reverses TPN-induced impairment of hepatic immunity along with increased hepatic MNC numbers and LPS receptor expressions on Kupffer cells.

Enteral Refeeding Rapidly Restores PN-Induced Reduction of Hepatic Mononuclear Cell Number Through Recovery of Small Intestine and Portal Vein Blood Flows

BACKGROUNDnAbsence of enteral nutrition (EN) reduces hepatic mononuclear cell (MNC) numbers and impairs their functions. However, enteral refeeding (ER) for as little as 12 hours following parenteral nutrition (PN) rapidly restores hepatic MNC numbers. We hypothesized that changes in small intestine and portal vein blood flows related to feeding route might be responsible for this phenomenon.nnnMETHODSnIn experiment 1, mice (n = 19) were randomized to Chow (n = 5), PN (n = 7) or ER (n = 7) groups. The Chow group was given chow ad libitum with intravenous (IV) saline for 5 days. The PN group was fed parenterally for 5 days, while the ER group was re-fed with chow for 12 hours following 5 days of PN. Then, small intestine and portal vein blood flows were monitored and hepatic MNCs were isolated and counted. In experiment 2, the effects of intravenous administration of prostaglandin E(1) (PGE(1)) on hepatic MNC numbers were examined in fasted mice for 12 hours. Mice (n = 28) were randomized to Control (n = 8), PG0 (n = 10), or PG1 (n = 10) groups. The Control group was fed chow ad libitum with IV saline, while the PG0 and PG1 groups were fasted for 12 hours with infusions, respectively, of saline and PGE(1) at 1 microg/kg/minute. Blood flows and hepatic MNC numbers were examined.nnnRESULTSnExperiment 1: ER restored PN-induced reductions in small intestine and portal vein blood flows and hepatic MNC number to the levels in the Chow group. Small intestine and portal vein blood flows correlated positively with hepatic MNC number. Experiment 2: Fasting decreased small intestine and portal vein blood flows and hepatic MNC number. However, PGE(1) restored portal vein blood flow to the level of the Control group, and moderately increased hepatic MNC number. There was a positive correlation between portal blood flow and hepatic MNC number.nnnCONCLUSIONSnReduced small intestine and portal vein blood flows may contribute to impaired hepatic immunity in the absence of EN. ER quickly restores hepatic MNC number through recovery of blood flow in both the small intestine and the portal vein.

Effects of semielemental diet containing whey peptides on Peyer's patch lymphocyte number, immunoglobulin A levels, and intestinal morphology in mice

BACKGROUNDnEnteral nutrition (EN) is the gold standard of nutritional therapy for critically ill or severely injured patients, because EN promotes gut and hepatic immunity, thereby preventing infectious complications as compared with parenteral nutrition. However, there are many EN formulas with different protein and fat contents. Their effects on gut-associated lymphoid tissue remain unclear. Recently, semielemental diets (SEDs) containing whey peptides as a nitrogen source have been found to be beneficial in patients with malabsorption or pancreatitis. Herein, we examined the influences of various dietary formulations on gut immunity to clarify the advantages of SEDs over elemental diets.nnnMETHODSnForty-four male Institute of Cancer Research mice were randomized to four groups: chow (CH: nxa0=xa05), intragastric total parenteral nutrition (IG-TPN: nxa0=xa013), elemental diet (ED: nxa0=xa013), and SED (nxa0=xa013). The CH group received CH diet ad libitum, whereas the IG-TPN, ED (Elental, Ajinomoto, Japan), and SED (Peptino, Terumo, Japan) groups were given their respective diets for 5xa0day via gastrostomy. After 5xa0days, the mice were killed to obtain whole small intestines. Peyers patch (PP) lymphocytes were harvested and counted. Their subpopulations were evaluated by flow cytometry. Immunoglobulin A (IgA) levels in intestinal and respiratory tract washings were measured with enzyme-linked immunosorbent assay. Villous height (VH) and crypt depth in the distal intestine were measured by light microscopy.nnnRESULTSnSED increased the PP cell number and intestinal or respiratory IgA levels to those of CH mice, while ED partially restored these parameters. The IG-TPN group showed the lowest PP cell number and IgA levels among the four groups. VH was significantly greater in the CH than in the other groups. VH in the ED and SED groups also exceeded in the IG-TPN group, while being similar in these two groups. No significant crypt depth differences were observed among the four groups.nnnCONCLUSIONSnSED administration can be recommended for patients unable tolerate complex enteral diets or a normal diet in terms of not only absorption and tolerability but also maintenance of gut immunity.

The influence of dietary restriction on hepatic mononuclear cell numbers and functions in mice

BACKGROUNDnSurgical patients with gastrointestinal malignancies are at increased risk for malnutrition. However, the mechanism by which dietary restriction (DR), one form of malnutrition, impairs hepatic immunity remains to be clarified. The present study was designed to examine the influence of DR on hepatic mononuclear cell (MNC) numbers, subpopulations, and cytokine productions (tumor necrosis factor α [TNF-α], interferon gamma [IFN-γ], and interleukin 10 [IL-10]) in response to lipopolysaccharide (LPS) in mice. Immunoglobulin (Ig) A levels in the gallbladder and histopathologic changes in the liver were also assessed.nnnMATERIAL AND METHODSnMale Institute of Cancer Research mice were randomly assigned to three dietary groups: ad libitum (AD), mild restriction (MR), and severe restriction (SR). The AD, MR, and SR groups received daily mouse chow in amounts of 190, 133, and 76 g/kg, respectively, for 7 d. After the mice had been fed for 7 d, hepatic MNCs were isolated. Total hepatic MNCs were counted and subpopulations were determined by flow cytometry. Cytokine productions (TNF-α, IFN-γ, and IL-10) by hepatic MNCs in response to LPS were measured. Blood samples were analyzed for hepatobiliary biochemical parameters. IgA levels in gallbladder bile were measured with enzyme-linked immunosorbent assay. In addition, liver histologies were examined.nnnRESULTSnHepatic MNC numbers were significantly lower in the MR and SR groups than in the AD group, with no significant difference between the MR and SR groups. The percentage of B cells was significantly lower in the SR group than in the MR and AD groups, whereas the T-cell percentage was higher in the SR group than in the MR and AD groups. The percentage of Kupffer cells was significantly lower in the SR group than in the AD group, whereas that in the MR group was midway between those in the SR and AD groups. TNF-α and IL-10 levels in hepatic MNC culture supernatants were increased LPS-dose dependently in the AD group. However, the increase was slight in the MR group and absent in the SR group. The IgA levels in gallbladder bile were significantly lower in the SR and MR groups than in the AD group. On the basis of hematoxylin and eosin staining of hepatic sections, livers from the SR group showed atrophic hepatocytes and sinusoidal dilatation, whereas these changes were absent in the AD group.nnnCONCLUSIONSnDR decreases hepatic MNC number with subpopulation changes, reduces IgA levels in gallbladder bile, blunts cytokine production by hepatic MNCs, and induces pathologic damage in the liver, which may be an important mechanism underlying the impaired host defense associated with malnutrition.

Influence of fish to soybean oil ratio on hepatic mononuclear cell function and survival after intraportal bacterial challenge in parenterally fed mice

BACKGROUNDnParenteral nutrition (PN) is indispensable for meeting the caloric and substrate needs of patients who cannot receive adequate amounts of enteral nutrition. However, PN decreases hepatic mononuclear cell (MNC) numbers and impairs their functions. We examined the effects of various ratios of ω-3 to ω-6 polyunsaturated fatty acids on hepatic MNC number and function in a murine model. We focused on serum liver enzymes, lipid metabolism, cytokine production, histopathology, and the outcomes of an intraportal bacterial challenge.nnnMATERIAL AND METHODSnIn experiment 1, male Institute of Cancer Research mice were randomized to CHOW, 67%, 33%, 16%, 8%, 4%, and 0% fish oil (FO)-PN groups. After receiving their respective diets for 5 days, 1.0 × 10(7) Pseudomonas aeruginosa were delivered by intraportal injection. Survival was observed ≤ 7 days after injection. Liver histologies after intraportal bacterial challenge were examined in the CHOW, 33%, 8%, and 0% FO-PN groups. In experiment 2, the mice were divided into 4 groups: CHOW, 33%, 8%, and 0% FO-PN. After the mice had been fed for 5 days, MNC were isolated. Hepatic MNC were counted and cytokine productions (tumor necrosis factor [TNF]-α and interleukin [IL]-10) by MNC in response to lipopolysaccharide (LPS) were measured. Blood samples were analyzed for lipid metabolism and hepatobiliary biochemical parameters. Liver histologies were also examined.nnnRESULTSnIn experiment 1, survival times were significantly shorter in the 4% and 0% FO-PN groups than in the CHOW group. Survival rates at 168 hours were 100%, 64%, 86%, 73%, 67%, 11%, and 13% in the CHOW, 67%, 33%, 16%, 8%, 4%, and 0% FO-PN groups, respectively. At 72 hours after intraportal bacterial challenge, the 0% FO-PN group showed severe tissue damage, whereas such damage was reduced in the 8% and 33% FO-PN groups. In experiment 2, the CHOW, 33%, 8%, and 0% FO-PN groups showed LPS dose-dependent increases in TNF-α levels. IL-10 levels were also LPS dose-dependently increased in the CHOW and 33% FO-PN groups. However, no marked changes were observed in response to LPS stimulation in either the 8% or the 0% FO-PN group. There were no differences in serum levels of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, or total bilirubin among these 4 groups. In the 0% FO-PN group, serum total cholesterol levels were greater than those in the 8% and 33% FO-PN groups. Without bacterial challenge, livers from the 0% FO-PN group showed steatosis, but these changes were attenuated in the 8% and 33% FO-PN groups.nnnCONCLUSIONnThe 30-40% ratio of FO to soybean oil with 20% of total calories supplied by lipid seems to be the best PN for preservation of hepatic MNC number and function.

Parenteral nutrition rapidly reduces hepatic mononuclear cell numbers and lipopolysaccharide receptor expression on Kupffer cells in mice.

BACKGROUNDnParenteral nutrition (PN) reduces the number of hepatic mononuclear cell (MNCs) and impairs their function, resulting in poor survival after intraportal bacterial challenge in mice. Our recent animal study demonstrated resumption of enteral nutrition after PN to rapidly restore hepatic MNC numbers (in 12 hours) and lipopolysaccharide (LPS) receptor expression on Kupffer cells (in 48 hours). The present study examined the time courses of hepatic MNC number reductions and LPS receptor expression changes in mice receiving PN.nnnMETHODSnMale mice (n = 49) from the Institute of Cancer Research were divided into chow (n = 8), PN0.5 (n = 8), PN1 (n = 8), PN2 (n = 9), PN3 (n = 9), and PN5 (n = 7) groups. The chow group was given chow with an intravenous saline infusion. The PN groups were fed parenterally for 0.5, 1, 2, 3, or 5 days following the chow-feeding courses. After 7 days of nutrition support, hepatic MNCs were isolated and counted. The expression of LPS receptors on Kupffer cells was analyzed by flow cytometry.nnnRESULTSnHepatic MNC numbers rapidly reached their lowest level in the PN0.5 and PN1 groups but were somewhat restored thereafter and remained stable after the third day, without significant differences between any 2 of the PN groups. CD14 and Toll-like receptor 4/MD-2 expressions both showed significant reductions in the PN1 group compared with the chow group and gradually decreased to their lowest levels in the PN5 group.nnnCONCLUSIONSnPN administration rapidly reduces hepatic MNC numbers and LPS receptor expression on Kupffer cells.

Noradrenalin effectively rescues mice from blast lung injury caused by laser-induced shock waves

BackgroundBlast lung injuries (BLI) caused by blast waves are extremely critical in the prehospital setting, and hypotension is thought to be the main cause of death in such cases. The present study aimed to elucidate the pathophysiology of severe BLI using laser-induced shock wave (LISW) and identify the initial treatment.MethodsThe current investigation comprised two parts. For the validation study, mice were randomly allocated to groups that received a single shot of 1.2, 1.3, or 1.4xa0J/cm2 LISW to both lungs. The survival rates, systolic blood pressure (sBP), heart rate (HR), peripheral oxyhemoglobin saturation (SpO2), and shock index were monitored for 60xa0min, and lung tissues were analyzed histopathologically. The study evaluated the effects of catecholamines as follows. Randomly assigned mice received 1.4xa0J/cm2 LISW followed by the immediate intraperitoneal administration of dobutamine, noradrenalin, or normal saline. The primary outcome was the survival rate. Additionally, sBP, HR, SpO2, and the shock index were measured before and 5 and 10xa0min after LISW, and the cardiac output, left ventricular ejection fraction, and systemic vascular resistance (SVR) were determined before and 1xa0min after LISW.ResultsThe triad of BLI (hypotension, bradycardia, and hypoxemia) was evident immediately after LISW. The survival rates worsened with increasing doses of LISW (100xa0% in 1.2xa0J/cm2 vs. 60xa0% in 1.3xa0J/cm2, 10xa0% in 1.4xa0J/cm2). The histopathological findings were compatible with those of human BLI. The survival rate in LISW high group (1.4xa0J/cm2) was highest in the group that received noradrenalin (100xa0%), with significantly elevated SVR values (from 565 to 1451xa0dynxa0s/min5). In contrast, the survival rates in the dobutamine and normal saline groups were 40 and 10xa0%, respectively, and the SVR values did not change significantly after LISW in either group.ConclusionsThe main cause of death during the initial phase of severe BLI is hypotension due to the absence of peripheral vasoconstriction. Therefore, the immediate administration of noradrenalin may be an effective treatment during the initial phase of severe BLI.

0919. Effect of catecholamine immediately after blast lung injury caused by laser-induced shock wave in a mouse model

The physical damage inflicted by blast waves is called primary blast injury, and lungs are vulnerable to blast waves [1]. Blast lung injuries (BLI) can be extremely critical during the super-acute phase, and hypotension is supposed to be the main cause of death (1) , but its etiology has not been elucidated. Recent studies have demonstrated that hypotension is mediated by the absence of vasoconstriction [2]. However, research investigated the effectiveness of catecholamine for BLI during the super-acute phase was not identified.