Pretreatment with enteral cholestyramine prevents suppression of the cellular immune system after partial hepatectomy

A review of the mechanism of injury and treatment approaches for illness resulting from exposure to water-damaged buildings, mold, and mycotoxins

Physicians are increasingly being asked to diagnose and treat people made ill by exposure to water-damaged environments, mold, and mycotoxins. In addition to avoidance of further exposure to these environments and to items contaminated by these environments, a number of approaches have been used to help persons affected by exposure to restore their health. Illness results from a combination of factors present in water-damaged indoor environments including, mold spores and hyphal fragments, mycotoxins, bacteria, bacterial endotoxins, and cell wall components as well as other factors. Mechanisms of illness include inflammation, oxidative stress, toxicity, infection, allergy, and irritant effects of exposure. This paper reviews the scientific literature as it relates to commonly used treatments such as glutathione, antioxidants, antifungals, and sequestering agents such as Cholestyramine, charcoal, clay and chlorella, antioxidants, probiotics, and induced sweating.

Effects of treatment with Tongfu Granules on intestinal cytokine levels in rats with endotoxemia

AIM: To observe the changes in the levels of intestinal cytokines in rats with endotoxemia and to investigate the effects of treatment with Tongfu Granules on intestinal cytokine levels.

METHODS: One hundred and twenty male Wistar rats were randomly divided into three groups: control group, endotoxemia group and treatment group. Endotoxemia was induced by a single injection of LPS via the caudal vein. The levels of intestinal cytokines were measured by ELISA and radioimmunoassay.

RESULTS: The level of IFN-γ at 24 h was significantly lower in the endotoxemia group than in the control and treatment groups (32.93 ng/L ± 13.17 ng/L, 37.14 ng/L ± 6.70 ng/L vs 23.21 ng/L ± 8.65 ng/L, both P < 0.05). The level of IFN-γ at 12 h was significantly higher in the treatment group than in the control group (39.96 ng/L ± 8.26 ng/L vs 29.64 ng/L ± 10.78 ng/L, P < 0.05). The level of IL-4 significantly decreased in the endotoxemia group at 6 h but increased at 24 h compared with the control and treatment groups (115.56 ng/L ± 17.67 ng/L, 124.39 ng/L ± 26.02 ng/L vs 83.36 ng/L ± 27.24 ng/L, both P < 0.05 or 0.01). IL-4 level at 24 h was significantly higher in the endotoxemia group than in the control group (107.96 ng/L ± 10.86 ng/L vs 92.21 ng/L ± 17.62 ng/L, P < 0.05). The levels of Foxp3 at 12 and 24 h were significantly higher in the endotoxemia group than in the control group (0.28 g/L ± 0.037 g/L vs 0.24 g/L ± 0.041 g/L; 0.26 g/L ± 0.029 g/L vs 0.22 g/L ± 0.041 g/L, both P < 0.05). The level of Foxp3 at 24 h was significantly lower in the treatment group than in the endotoxemia group (0.23 g/L ± 0.030 g/L vs 0.26 g/L ± 0.029 g/L, P < 0.05). The levels of sIgA at 2, 12 and 24 h was significantly lower in the endotoxemia group than in the control and treatment groups (2.43 × 10^-11 ± 0.23 × 10^-11, 2.18 × 10^-11 ± 0.27 × 10^-11vs 1.66 × 10^-11 ± 0.25 × 10^-11; 2.76 × 10^-11 ± 0.22 × 10^-11, 2.64 × 10^-11 ± 0.22 × 10^-11vs 2.09 × 10^-11 ± 0.20 × 10^-11; 2.48 × 10^-11 ± 0.31 × 10^-11, 2.25 × 10^-11 ± 0.44 × 10^-11vs 1.88 × 10^-11 ± 0.45 × 10^-11, all P < 0.05). The level of sIgA at 2 h was significantly lower in the treatment group than in the control group.

CONCLUSION: Small intestinal mucosa injury and deregulated inflammatory reaction can result in intestinal immunodepression in rats with endotoxemia. Treatment with Tongfu Granules can protect intestinal immune function in rats with endotoxemia by reducing small intestinal mucosa injury and bidirectionally regulating inflammatory reaction.

Decreased IgA+ plasma cells and IgA expression in acute liver necrosis mice

AIM: To investigate the number of intestinal immunoglobulin A (IgA+) plasma cells and expression of intestinal IgA in mice with acute liver necrosis.

METHODS: A model of acute liver necrosis was established by intraperitoneal injection of galactosamine (GalN) and lipopolysaccharide (LPS). Sixty mice were randomly divided into one of 4 equal groups: normal control, acute liver necrosis, LPS, or GalN. Hematoxylin and eosin staining, immunohistochemistry, and an enzyme-linked immunosorbent assay were employed to assess liver and intestinal injury, count intestinal IgA+ plasma cells, and measure the expression level of IgA and interferon γ (IFN-γ) in the small intestinal mucosa of mice.

RESULTS: Injured intestinal mucosa was observed in the acute liver necrosis group but not in the normal, LPS or GalN groups. Compared with the normal group, intestinal IgA+ plasma cells were slightly decreased in the LPS and GalN groups [429 ± 20 per high power field (HPF), 406 ± 18/HPF, respectively], whereas they were markedly decreased in the acute liver necrosis group (282 ± 17/HPF vs 495 ± 26/HPF in normal group, P < 0.05). The expression of intestinal IgA was also slightly decreased in LPS and GalN groups, but was markedly reduced in the acute liver necrosis group as determined by enzyme-linked immunosorbent assay (P < 0.05). In contrast, the level of IFN-γ was slightly increased in LPS, GalN and acute liver necrosis groups, but with no statistical significance (P > 0.05).

CONCLUSION: Intestinal IgA+ plasma cells and IgA expression levels indicating that mucosal immune barrier dysfunction, does exist in acute liver necrosis.

Changes in intestinal mucosal immune barrier in rats with endotoxemia

AIM: To investigate the dysfunction of the immunological barrier of the intestinal mucosa during endotoxemia and to elucidate the potential mechanism of this dysfunction.

METHODS: Male Wistar rats were randomly distributed into two groups: control group and lipopolysaccharide (LPS) group. Endotoxemia was induced by a single caudal venous injection of LPS. Animals were sacrificed in batches 2, 6, 12 and 24 h after LPS infusion. The number of microfold (M)-cells, dendritic cells (DCs), CD4⁺ T cells, CD8⁺ T cells, regulatory T (Tr) cells and IgA⁺ B cells in the intestinal mucosa were counted after immunohistochemical staining. Apoptotic lymphocytes were counted after TUNEL staining. The levels of interleukin (IL)-4, interferon (IFN)-γ and forkhead box P3 (Foxp3) in mucosal homogenates were measured by ELISA. The secretory IgA (sIgA) content in the total protein of one milligram of small intestinal mucus was detected using a radioimmunological assay.

RESULTS: This research demonstrated that LPS-induced endotoxemia results in small intestinal mucosa injury. The number of M-cells, DCs, CD8⁺ T cells, and IgA⁺ B cells were decreased while Tr cell and apoptotic lymphocyte numbers were increased significantly. The number of CD4⁺ T cells increased in the early stages and then slightly decreased by 24 h. The level of IL-4 significantly increased in the early stages and then reversed by the end of the study period. The level of IFN-γ increased slightly in the early stages and then decreased markedly by the 24 h time point. Level of Foxp3 increased whereas sIgA level decreased.

CONCLUSION: Mucosal immune dysfunction forms part of the intestinal barrier injury during endotoxemia. The increased number and function of Tr cells as well as lymphocyte apoptosis result in mucosal immunodeficiency.

Mitochondrial membrane potential is reduced in peripheral natural killer cells following partial hepatectomy

The mechanism underlying immunosuppression after partial hepatectomy remains unclear. Hepatectomy induces lymphopenia, which is related to immunomodulation. The aim of this study was to determine whether peripheral blood lymphocytes (PBL) are susceptible to mitochondria-mediated apoptosis after hepatic resection. We compared the changes in mitochondrial membrane potential in lymphocytes from hepatectomized patients with metastatic liver tumor with the corresponding changes in lymphocytes from cholechystectomized patients, because changes in mitochondrial membrane potential have been reported to frequently occur during the early stages of apoptosis. Mitochondrial membrane potential, subpopulation, and apoptosis of lymphocytes were estimated with flow cytometry. Hepatectomy significantly (P<0.001) reduced postoperative mitochondrial membrane potential, while cholecystectomy slightly decreased it. Apoptosis of lymphocytes was increased on post-hepatectomy day, and this increase was correlated with the extent of mitochondrial membrane potential reduction. The major subset of lymphocytes with low mitochondrial membrane potential consisted of CD56(+) natural killer (NK) cells, and NK cell activity and cell counts significantly decreased after hepatectomy. Mitochondrial membrane potential of PBL was reduced after hepatectomy, and some lymphocytes underwent apoptosis through the mitochondrial pathway, which was one of the causes for lymphopenia. NK cells were more responsible for the decrease of mitochondrial membrane potential after hepatectomy than other lymphocytes, and the reduction in mitochondrial membrane potential in NK cells appeared to reflect modulation of the innate immune system.

Perioperative anti-endotoxin strategies

Lipopolysaccharides from the outer membrane of Gram-negative bacteria are potent stimuli for the production of numerous cytokines by the immune cells. The systemic inflammatory response to these gut-derived endotoxins is therefore dependent on the responsiveness of the immune system. This paper presents results on anti-endotoxin strategies and the responsiveness to endotoxin in animal models of liver failure. Following partial hepatectomy in the normal rat, anti-endotoxin treatment using the enteral endotoxin binder cholestyramine and the bactericidal permeability-increasing protein showed beneficial effects in terms of reducing the exaggerated metabolic and inflammatory responses. Similar beneficial effects of gut endotoxin restriction were found in bile duct ligated rats subjected to a laparotomy. The beneficial effects of anti-endotoxin strategies in these models were explained by completely different mechanisms. In partial hepatectomized rats the effects were explained by the direct inhibition of the stimulatory action of endotoxin on immune cells preventing an exaggerated inflammatory response. In contrast, in postoperative BDL rats the effects of anti-endotoxin therapy were explained by the restoration of endotoxin sensitivity of the immune cells resulting in an inflammatory response necessary for an adequate reaction to surgery. These different mechanism will be discussed in the light of the phenomenon of endotoxin tolerance.