Prehabilitation Ameliorates Gut Ischemia Reperfusion Injury in Mice.

INTRODUCTION: We previously demonstrated that prehabilitation by running on a treadmill leads to improved survival after gut ischemia reperfusion (I/R) in mice. The purpose of this research was to examine whether prehabilitation attenuates inflammatory responses after gut I/R in mice. MATERIALS AND METHODS: Male C57BL/6J mice (n = 92) were assigned to the sedentary (n = 46) or the exercise (n = 46) group. The exercise group ran on a treadmill for 4 wk, while the sedentary mice did not exercise. After the 4-week pretreatment, all mice underwent gut I/R and the blood, urine, small intestine, lung, liver, and gastrocnemius were harvested prior to ischemia or at 0, 3, 6, or 24 h after reperfusion. Histologically demonstrated organ damage, cytokine levels in the blood, gut and gastrocnemius, myeloperoxidase activity in the gut, 8-hydroxy-2'-deoxyguanosine levels in urine and the gut, and adenosine triphosphate (ATP) and ATP + ADP + adenosine monophosphate levels in the gut and gastrocnemius were evaluated. RESULTS: The treadmill exercise reduced gut and lung injuries at 3 h and liver injury at 6 h after reperfusion. Running on the treadmill also decreased proinflammatory cytokine levels in the blood at 6 h, gut at 3 h and gastrocnemius at 6 h after reperfusion, myeloperoxidase activity in the gut prior to ischemia, and 6 h after reperfusion and the urinary 8-hydroxy-2'-deoxyguanosine level at 24 h after reperfusion, while ATP levels in exercised mice prior to ischemia and 3 h after reperfusion were increased in the intestine as compared to the levels in sedentary mice. CONCLUSIONS: Prehabilitation with treadmill exercise reduces inflammatory responses after gut I/R and may exert protective actions against gut I/R.

Influence of a Low-Carbohydrate High-Fat Diet on Peritoneal Inflammation, Cancer-Associated Lymphocytes, and Survival in a Murine Carcinomatous Peritonitis Model.

BACKGROUND: Low-carbohydrate high-fat diets (LCHFDs) are thought to be beneficial for metabolic support in patients with advanced cancer. However, whether LCHFDs affect the progression of carcinomatous peritonitis (CP) remains unclear. Our study examined the influence of a lard-based LCHFD on host immunity and survival in a murine CP model. METHODS: Mice were fed either a normal diet (ND) or an LCHFD ad libitum. On day 7, Panc02 cancer cells were inoculated intraperitoneally. Mice were killed on days 7, 21, and 35, and cytokine levels in the peritoneal fluid, as well as the number and phenotypes of peritoneal, splenic, and tumor-infiltrating lymphocytes were measured. Survival studies were performed with both ad libitum and isocaloric feeding in other sets of mice. RESULTS: The levels of all cytokines significantly increased in the LCHFD group compared with those in the ND group on day 21. The tumor necrosis factor α and interleukin-10 levels were higher in the LCHFD group than in the ND group on day 35. In the LCHFD group, the regulatory T-cell (Treg) number was significantly higher in the peritoneal cavity and tumor. The survival times were worse in the LCHFD group than in the ND group. CONCLUSION: The ad libitum, lard-based LCHFD feeding of CP mice increases the peritoneal cytokine levels, which may reduce splenic, anticancer lymphocytes and increase the number of Tregs in the peritoneal cavity and tumor. The detrimental effects of LCHFD are linked to dietary composition rather than overfeeding.

Influences of Short-Term Fasting and Carbohydrate Supplementation on Gut Immunity and Mucosal Morphology in Mice.

BACKGROUND: Preoperative carbohydrate (CHO) supplementation has been recommended in enhanced recovery after surgery protocols. However, the effects of CHO supplementation on gut and systemic immunity are not well understood. METHODS: Mice (n = 60) were randomized to 1 of the following 5 groups: control (ad lib feeding), 12-hour fasting without CHO administration (fasting), and 12 hours of fasting with CHO administration at 2, 4, and 8 hours before sacrifice. Then, lymphocytes were isolated from gut-associated lymphoid tissue, that is, Peyer's patches, the intraepithelial space, and the lamina propria of the small intestine. These lymphocyte numbers and phenotypes were evaluated. IgA levels in respiratory and small-intestinal washings were determined by ELISA. Morphology, proliferation, and apoptosis of the intestinal epithelium were also evaluated histologically. RESULTS: Although there were no significant differences in IgA levels among the 5 groups, fasting decreased intraepithelial and lamina propria, but not Peyer's patches lymphocyte numbers. CHO at 2 hours prevented lymphocyte loss in intraepithelial, whereas CHO at 4 hours reversed lamina propria lymphocytes numbers. Percentages of lymphocyte phenotypes were similar in each site among the 5 groups. Fasting caused villous atrophy; however, CHO at 2 hours restored villous structure along with maintenance of epithelial cell proliferation rate. CONCLUSIONS: Only 12 hours of fasting causes marked gut-associated lymphoid tissue cell loss along with gut atrophy. However, CHO at 2 hours preserves gut immunity and morphology not completely but moderately.

Cystine and Theanine Improve Survival after Gut Ischemia-Reperfusion.

BACKGROUND AND AIM: Oral administration of cystine and theanine (CT) may modulate antioxidant glutathione (GSH) metabolism, thereby improving outcomes after gut ischemia reperfusion. METHODS: Experiment 1: Institute of Cancer Research mice (n = 35) were assigned to a Vehicle (n = 11), a CT140 (n = 14), or a CT280 (n = 10) group. The CT140 and 280 groups were given CT at respective dosages of 140 and 280 mg/kg (cystine: theanine = 5: 2) once daily via gavage for 5 days. All mice underwent 75-min occlusion of the superior mesenteric artery (SMA). Survival after reperfusion was observed. Experiment 2: Mice (n = 67) were pretreated for 5 days (Vehicle: n = 24, CT280: n = 20, vehicle/sham: n = 23). The Vehicle and CT280 groups underwent 60-min SMA occlusion. Levels of GSH, the oxidized form of GSH, Glutathione-S-S-Glutathione (GSSG), and GSH-related amino acids (cysteine and glutamic acid) in the small intestine, and plasma cytokine (IL-6, IL-1ß, TNFα) levels, were evaluated before (0 h), 3, 6, or 9 h after reperfusion. RESULTS: Experiment 1: The CT280 group showed significantly better survival than the Vehicle group. Experiment 2: Gut GSSG, cysteine, and glutamic acid levels were higher in the CT280 than in the Vehicle group after reperfusion. Plasma IL-6 and TNFα levels rose more rapidly in the CT280 than in the Vehicle group. CONCLUSION: Oral administration of CT improves survival after gut I/R, possibly through the modulation of the GSH-redox cycle and cytokine responses.

Influences of Vagotomy on Gut Ischemia-Reperfusion Injury in Mice.

BACKGROUND: How vagotomy affects host responses to gut ischemia-reperfusion (I/R) is unclear. MATERIALS AND METHODS: Experiment 1: male Institute of Cancer Research mice (n = 22) were assigned to the I/R or the vago-I/R group. The I/R mice underwent 45-min superior mesenteric artery (SMA) occlusion. The vago-I/R mice received vagotomy before SMA occlusion. Survival was observed for 48 h.Experiment 2: mice (n = 55) were divided into four groups (Sham, vago, I/R, vago-I/R). Sham and vago groups did not undergo gut I/R. Mice were killed at 3 or 6 h after reperfusion, and cytokine levels in the plasma, jejunum, and ileum were evaluated. In addition, gut histology at 6 h was examined.Experiment 3: mice (n = 24) were divided into four groups as in Experiment 2. The small intestine was harvested at 3 h after reperfusion and the tissue was cultured ex vivo for 3 h. Cytokine levels of the culture supernatant were then measured. RESULTS: Experiment 1: survival was significantly worse with vago-I/R than I/R.Experiment 2: along with severe gut injury, vago-I/R increased IL-6 and monocyte chemoattractant protein-1 (MCP-1) in plasma, IFN-γ in the jejunum and MCP-1 in the ileum, as compared with I/R. Significant positive correlations were noted between plasma and intestinal levels of pro-inflammatory cytokines (IL-6, MCP-1, and TNF-α).Experiment 3: MCP-1 in the jejunal culture medium was higher in the vago-I/R than in the I/R group. CONCLUSIONS: Vagotomy worsens survival after gut I/R, together with increases in pro-inflammatory cytokines in both plasma and the gut in association with severe intestinal tissue damage.

Challenging Residual Contamination of Instruments for Robotic Surgery in Japan.

BACKGROUND Recently, robotic surgery has been introduced in many hospitals. The structure of robotic instruments is so complex that updating their cleaning methods is a challenge for healthcare professionals. However, there is limited information on the effectiveness of cleaning for instruments for robotic surgery. OBJECTIVE To determine the level of residual contamination of instruments for robotic surgery and to develop a method to evaluate the cleaning efficacy for complex surgical devices. METHODS Surgical instruments were collected immediately after operations and/or after in-house cleaning, and the level of residual protein was measured. Three serial measurements were performed on instruments after cleaning to determine the changes in the level of contamination and the total amount of residual protein. The study took place from September 1, 2013, through June 30, 2015, in Japan. RESULTS The amount of protein released from robotic instruments declined exponentially. The amount after in-house cleaning was 650, 550, and 530 µg/instrument in the 3 serial measurements. The overall level of residual protein in each measurement was much higher for robotic instruments than for ordinary instruments (P<.0001). CONCLUSIONS Our data demonstrated that complete removal of residual protein from surgical instruments is virtually impossible. The pattern of decline differed depending on the instrument type, which reflected the complex structure of the instruments. It might be necessary to establish a new standard for cleaning using a novel classification according to the structural complexity of instruments, especially for those for robotic surgery. Infect Control Hosp Epidemiol 2017;38:143-146.

Time-dependent influence on assessment of contaminated environmental surfaces in operating rooms.

BACKGROUND: There is no established method to assess the contamination of environmental surfaces because the results change with time. We evaluated current methods for assessment of contamination of environmental surfaces in the operating room (OR). METHODS: Contamination of environmental surfaces in the OR was assessed using an adenosine triphosphate (ATP) test and bacterial culture. We collected 480 ATP test samples from 17 surfaces in 6 ORs to determine the influence of surface features, including frequency of touching and surface orientation on contamination, after completion of daily scheduled operations. Another 54 pairs of ATP and microbial samples were taken from 3 surfaces in each of the same OR except 1 to determine the time course of the results of ATP and microbial tests when ORs were not used. RESULTS: Multivariate analysis demonstrated that the ATP results were strongly influenced by frequency of touching and orientation of environmental surfaces. The microbial counts declined over time, whereas the ATP results remained at a high level. CONCLUSION: The ATP test result could be used as a relatively stable trace of contamination of environmental surfaces; however, it is not a surrogate indicator of the number of viable microbes which declines over time.

Occult risk of broken instruments for endoscopy-assisted surgery.

BACKGROUND: The influence of broken sophisticated surgical instruments on the safety of surgery has yet to be determined, in spite of an assumption that breakage of surgical instruments is not associated with critical incidents. The purpose of the present study was to delineate the risk from breakage of surgical instruments used in surgery assisted by endoscopy. METHODS: A retrospective analysis was conducted to determine the frequency of breakage of instruments used in 39,817 operations from 2007 to 2011. Data of breakage were collected using incident/near-incident reports and the request forms for repair of broken instruments. RESULTS: During the study period, 441 instruments were reported to be broken intraoperatively, and 7,541 were found to be broken on inspection. The incidence of breakage adjusted by the number of operations and the number of uses suggested that instruments for endoscopy-assisted surgery are broken more frequently intraoperatively than are any other type of instruments (visceral surgery: 0.039 versus 0.017, P = 0.0002, RR = 2.318; obstetrics/gynecology: 0.023 versus 0.0067, P < 0.0001, RR = 3.461; thoracic surgery: 0.019 versus 0.004, P = 0.0772, RR = 5.212). Inappropriate use and wearing out were two major possible causes of breakage of instruments. The predominant adverse events were suggested to be attributable to parts falling off broken instruments because of inappropriate use. CONCLUSIONS: Our results demonstrated that surgery assisted by endoscopy has its own occult risk, which has not been previously highlighted. Minimally invasive surgery is not necessarily safe with respect to breakage of surgical instruments. Our data provide substantial evidence for higher risk of instrument breakage in endoscopy-assisted surgery, as well as its possible detrimental effect on patient safety.

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

BACKGROUND: Parenteral 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. MATERIAL AND METHODS: In 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. RESULTS: In 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. CONCLUSION: The 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.

Intravenous administration of high-dose Paclitaxel reduces gut-associated lymphoid tissue cell number and respiratory immunoglobulin A concentrations in mice.

BACKGROUND: Chemotherapy remains a mainstay of treatment for cancer patients. However, anti-cancer drugs frequently cause a wide range of side effects, including leukopenia and gastrointestinal toxicity. These adverse effects can lead to treatment delays or necessitate temporary dose reductions. Although chemotherapy-related changes in gut morphology have been demonstrated, the influences of chemotherapeutic regimens on gut immunity are understood poorly. This study aimed to examine whether the anti-cancer drug paclitaxel (PTX) impairs gut immunity in mice. METHODS: Male ICR mice were randomized into three groups: Control, low-dose PTX (low PTX; 2 mg/kg), or high-dose PTX (high PTX; 4 mg/kg). A single intravenous dose was given. On day seven after the injection, lymphocytes from Peyer patches (PP), intraepithelial (IE) spaces, and the lamina propria (LP) were counted and analyzed by flow cytometry (CD4(+), CD8(+), αßTCR(+), γδTCR(+), B220(+)). Immunoglobulin A (IgA) concentrations were measured in small intestinal and respiratory tract washings. RESULTS: Total, CD4(+) and γδTCR(+) lymphocyte numbers in PPs were significantly lower in the high PTX than in the control group. The CD4(+) lymphocyte numbers in the IE spaces were significantly lower in both PTX groups than in the control group. Respiratory tract IgA concentrations were lower in the high PTX than in the control group. CONCLUSION: The present data suggest high-dose PTX impairs mucosal immunity, possibly rendering patients more vulnerable to infection. Careful dose selection and new therapies may be important for maintaining mucosal immunity during PTX chemotherapy.

Truncal vagotomy temporarily decreases the pro- and anti-inflammatory cytokine levels in the small intestine.

PURPOSE: The vagus nerve exerts immunomodulatory functions by inhibiting pro-inflammatory cytokine overproduction. Because vagotomy is a standard procedure during the radical operation for esophageal or gastric cancer, the postoperative clinical course might be related to vagotomy-associated changes in the cytokine milieu. We herein examined the gut cytokine kinetics after vagotomy in mice. METHODS: Thirty-eight male Institute of Cancer Research mice underwent sham or sub-diaphragmatic truncal vagotomy. The whole small intestine was harvested on postoperative day (POD) 14 (sham: vagotomy, n = 9:10) or 20 (n = 9:10). The pro- and anti-inflammatory cytokine levels in the plasma, jejunum, ileum and whole small intestine were evaluated. RESULTS: The plasma cytokine levels were similar in the vagotomy and sham groups on POD 14 and 20. However, both the pro- and anti-inflammatory cytokine levels tended to be lower on POD 14 and higher on POD 20 in the vagotomy group than in the sham group. With regard to the cytokine kinetics, the jejunal IL-12p70, TNF-α, MCP-1 and IL-10, ileal IL-12p70, TNF-α, IL-6, MCP-1 and IL-10, and whole small intestinal IL-12p70, TNF-α, IFN-γ, MCP-1 and IL-10 of the vagotomy group all significantly increased on POD 20 as compared to POD 14. CONCLUSION: Vagotomy has a major impact on the gut cytokine milieu. Vagotomy may initially inhibit both pro- and anti-inflammatory cytokine production, while both later increase.

Interleukin-7 treatment reverses parenteral nutrition-induced impairment of resistance to bacterial pneumonia with increased secretory immunoglobulin A levels.

BACKGROUND: Absence of enteral delivery of nutrients causes gut associated lymphoid tissue (GALT) atrophy and an imbalance between immunoglobulin A (IgA)-inhibiting Th1 and IgA-stimulating Th2 cytokine levels in the gut, leading to impaired mucosal immunity. We previously demonstrated exogenous IL-7 to reverse parenteral nutrition (PN)-induced GALT cell loss but not to normalize the gut cytokine imbalance or reduce secretory IgA levels, in uninjured mice. Herein, we examined effects of exogenous IL-7 during PN on survival and IgA levels after intra-tracheal bacterial challenge. METHODS: Sixty-five male Institute of Cancer Research (ICR) mice were randomized to chow, PN or PN+IL-7 (1 µg/kg, administered i.v. twice a day), and jugular vein catheters were inserted. The chow and PN mice received normal saline i.v. infusions instead of IL-7. After 5 d of feeding (chow or PN) and treatment, 8 × 10(7)Pseudomonas aeruginosa were instilled intra-tracheally. Survival was observed in 41 mice, while 24 were killed at 6 h after challenge and small intestinal, nasal and bronchoalveolar washings were obtained for IgA measurement. RESULTS: PN significantly reduced survival time and IgA levels in small intestine and bronchoalveolar washings compared with chow feeding. IL-7 treatment restored these parameters. Therefore, no significant differences in survival or secretory IgA levels were found between the chow and PN+IL-7 groups. CONCLUSIONS: Exogenous IL-7 reverses PN-induced impairment of resistance to respiratory tract infections associated with increased secretory IgA levels.

Effects of adding butyric acid to PN on gut-associated lymphoid tissue and mucosal immunoglobulin A levels.

BACKGROUND: Parenteral 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. METHODS: Male 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 Peyer's patches (PPs) to determine lymphocyte numbers and phenotypes (αßTCR(+), 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. RESULTS: Lymphocyte 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. CONCLUSIONS: A new PN formula containing butyric acid is feasible and would ameliorate PN-induced impairment of mucosal immunity.

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

BACKGROUND: Parenteral 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. METHODS: Male 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. RESULTS: Hepatic 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. CONCLUSIONS: PN administration rapidly reduces hepatic MNC numbers and LPS receptor expression on Kupffer cells.