Liver inflammatory cells, apoptosis, regeneration and stellate cell activation in non-alcohol steatohepatitis

Background, The pathogenesis of non-alcoholic steatohepatitis remains unclear from several points of view. Minimal diagnostic criteria are still not defined. Aim. To gather information useful for diagnosis and to improve the understanding of pathogenic mechanisms.

Patients. A series of 14 patients with non-alcoholic steatohepatitis, identified among liver outpatients, were paired for age, sex and alanine amino transferase values with 14 patients with hepatitis C virus infection without steatosis.

Methods. Clinical, biochemical and immunohistological examination, including characterisation of inflammatory cell population, evaluation of type 111 collagen and tenascin deposition, activation of stellate cells, hepatocellular apoptosis and proliferation.

Results. Patients with non-alcoholic steatohepatitis were more frequently obese, had higher triglyceride concentrations and lower gamma-globulins. T lymphocytes outnumbered polymorphonuclear cells, both in hepatitis C and in steatohepatitis, with a larger number of CD8 lymphocytes in patients with viral hepatitis but a comparable number of granulocytes. This resulted in a higher granulocytes to T cells ratio in steatohepatitis, possibly making these cells more easily detectable in spite of similar absolute numbers. Portal fibrosis and piecemeal necrosis were prevalent in hepatitis C virus infection, pericentral fibrosis was similar. Hepatocellular, apoptosis and proliferation as well as stellate cell activation were less relevant in steatohepatitis than in hepatitis C virus infection in spite of similar alanine amino transferase levels.

Conclusions. These data provide a possible explanation for the relatively low tendency to progression of non-alcoholic steatohepatitis in most patients despite increased alanine amino transferase and suggest that non-death-related release of alanine amino transferase might occur in non-alcoholic steatohepatitis. This makes liver biopsy an essential part of the clinical setting supporting diagnosis, evaluation of severity and possibly definition of the evolutionary trend.     

A comparison of the effects of oral prednisone and inhaled beclomethasone dipropionate on circulating leukocytes

Background: While the side effects of oral glucocorticoids are well recognised there is debate about the systemic effects of high doses of inhaled glucocorticoids such as beclomethasone dipropionate and how these compare with the effects of oral prednisone. Aim: To compare the effects of different doses of oral prednisone and inhaled beclomethasone dipropionate (BDP) on changes in circulating leukocytes. Methods: Changes in different subsets of circulating leukocytes were measured as an index of the systemic effects of inhaled BDP and oral prednisone. We compared the effects of inhaled placebo and 500 and 1000 μg of inhaled BDP with oral placebo and 2.5, 5 and 10 mg of prednisone in eight healthy volunteers. Leukocyte numbers were measured before and four hours after each dose of medicine. Results: Compared with inhaled placebo, 1000 (xg of inhaled BDP led to a significant increase in neutrophils as a percentage of the total white count (ρ<0.05) and a significant decrease in the total lymphocyte number (ρ<0.05) and in the number of CD4 lymphocytes (ρ<0.05). For 1000 μg BDP the increase in the % neutrophil count was 8.55% (95% CI 5.17 to 11.93) and the fall in lymphocyte numbers was -0.14X107L (95% CI 0.06 to -0.34) while 2.5mg prednisone led to an increase in the % neutrophil count of 9.31% (95% CI 5.82 to 12.80) and a fall in lymphocyte numbers of -0.07X 107L (95% CI 0.05 to -0.19). Conclusions: The systemic effects of 1000 μg inhaled BDP and 2.5 mg of prednisone are similar.     

Toxicology of 3-epi-deoxynivalenol,a deoxynivalenol-transformation product by Devosia mutans 17-2-E-8

Microbial detoxification of deoxynivalenol (DON) represents a new approach to treating DON-contaminated grains. A bacterium Devosia mutans 17-2-E-8 was capable of completely transforming DON into a major product 3-epi-DON and a minor product 3-keto-DON. Evaluation of toxicities of these DON-transformation products is an important part of hazard characterization prior to commercialization of the biotransformation application. Cytotoxicities of the products were demonstrated by two assays: a MTT bioassay assessing cell viability and a BrdU assay assessing DNA synthesis. Compared with DON, the IC₅₀ values of 3-epi-DON and 3-keto-DON were respectively 357 and 3.03 times higher in the MTT bioassay, and were respectively 1181 and 4.54 times higher in the BrdU bioassay. Toxicological effects of 14-day oral exposure of the B6C3F₁ mouse to DON and 3-epi-DON were also investigated. Overall, there were no differences between the control (free of toxin) and the 25 mg/kg bw/day or 100 mg/kg bw/day 3-epi-DON treatments in body and organ weights, hematology and organ histopathology. However, in mice exposed to DON (2 mg/kg bw/day), white blood cell numbers and serum immunoglobulin levels were altered relative to controls, and lesions were observed in adrenals, thymus, stomach, spleen and colon. Taken together, in vitro and in vivo studies indicate that 3-epi-DON is substantially less toxic than DON.     

Evidence for a neutrophil-mediated protective response in malaria

Zymosan-activated and non-activated human polymorphonuclear neutrophils (PMN) were added to in-vitro cultures of the human malaria parasite Plasmodium falciparum in microtitre wells. Microscopic counting of parasites in Giemsa-stained smears showed that at a PMN:RBC ratio of 1:150, the same as occurs in human malaria, parasites in wells with zymosan-activated neutrophils were suppressed 65%. Determination of parasite nucleic acid synthesis by 3H-hypoxanthine incorporation showed that in wells with PMN:RBC ratio of 1:150 parasite viability was only 22% of control. Various oxygen scavengers were tested for ability to reverse the effects of activated neutrophils on parasite development. Superoxide dismutase (20 mg/ml) and catalase (50 mg/ml) had no effect; tryptophan protected the parasites to a moderate degree while histidine alleviated suppression of parasite development to the greatest extent. This suggests that singlet oxygen is the most effective neutrophil product in killing or suppressing the growth of parasites. We also observed that non-activated neutrophils were activated by parasites and/or their products resulting in killing of newly-released parasites.     

特发性肺纤维化患者支气管肺泡灌洗液中白细胞介素13的水平及意义

目的　探讨特发性肺纤维化 (IPF)患者支气管肺泡灌洗液 (BALF)和外周血中白细胞介素 13 (IL 13 )水平的变化及其意义。方法　选择 17例IPF患者 (IPF组 )和 8名无器质性肺疾病者 (对照组 )。采用IL 13特异的酶联免疫吸附法测定 (ELISA)法检测 2组BALF和外周血中IL 13的水平 ,分析患者IL 13水平与其肺功能、血气之间的关系。结果　IPF组BALF和外周血中IL 13水平分别为(3 0 1± 86)ng/L、(178± 3 6)ng/L ;对照组分别为 (10 3± 2 4)ng/L、(55± 15)ng/L ,两者比较差异均有显著性 (P <0 0 1)。IPF组BALF中IL 13水平与BALF中性粒细胞数呈正相关 (r =0 786,P <0 0 1) ,与用力肺活量、一秒钟用力呼气容积、肺一氧化碳弥散量及动脉血氧分压均呈一定的等级负相关 (r分别为 -0 898、-0 878、-0 874、-0 890 ,P均 <0 0 1)。结论　IL 13可能在IPF的发病过程中起一定作用 ,并有可能作为判断病变进展情况的一项指标     

Releasability of human hypereosinophilic eosinophils is related to the density of the cells

The activity of eosinophils and neutrophils with respect to the release of granule proteins was studied in 11 patients with the hypereosinophilic syndrome (HES). Granulocytes or purified eosinophils were stimulated with serum-opsonized Sephadex particles (C3b-induced release), and the released amounts of eosinophil cationic protein (ECP), eosinophils protein-X (EPX) and myeloperoxidase (MPO) were measured by means of specific radioimmunoassays (RIA). Eosinophils obtained from patients with HES released significantly more ECP ( P <0·002) and EPX ( P <0·01) after 20 min of incubation than cells from the control group. The cellular content of ECP and EPX in eosinophils obtained from the patients with HES was significantly reduced to 50% and 62%, respectively, of the content of these granule proteins of eosinophils from the control group. In separated eosinophils light-density eosinophils released more of both ECP and EPX than normal density eosinophils. There was no difference in MPO release between the patients and the control group. We conclude that the eosinophils from patients with HES have an increased propensity to release their granule proteins and the releasability seems to be related to the density of the cells.     

Cellular immune reactions in the lung

The lung constantly interacts with the environment through thousands of liters of air that are inhaled daily. This continually transports toxic chemicals and particles or pathogenic microorganisms deep into the respiratory system, posing a challenge to physicochemical barriers and the local immune system. Thus, complex structures and mechanisms have evolved to recognize and fend off environmental dangers while at the same time allowing efficient gas exchange. Here we review our current knowledge regarding cellular mechanisms of the immune system in context with the highly specialized anatomical features of the airways and especially the alveolar compartment. The focus is on fungal and viral infections, merging anatomical aspects well known to pulmonologists with fundamental immunological concepts. We discuss the specialized morphological constraints of immune cells compressed under a continuous layer of the surfactant lining within alveoli as well as the importance of functional polarization of respiratory tract epithelia. Furthermore, we summarize the different types of innate and adaptive immune cells and their relative contribution to lung homeostasis with respect to localization. Finally, we provide a list of currently unresolved questions with high relevance for the field that might serve as food for thought regarding future research directions.     

TNF-α and IL-1β sensitize human MSC for IFN-γ signaling and enhance neutrophil recruitment

During inflammatory processes, tissue environmental cues are influencing the immunoregulatory properties of tissue-resident mesenchymal stem/stromal cells (MSC). In this study, we elucidated one of the molecular and cellular responses of human MSC exposed to combinations of inflammatory cytokines. We showed that during multi-cytokine priming by TNF-α, IL-1β, and IFN-γ, IL-1β further augmented the well-established immunoregulatory activity induced by TNF-α/IFN-γ. On the molecular level, TNF-α and IL-1β enhanced the expression of IFN-γ receptor (IFN-γR) via NF 'kappa-light-chain-enhancer' of activated B-cells (NF-κΒ) signaling. In turn, enhanced responsiveness to IFN-γ stimulation activated STAT5 and p38-MAPK signaling. This molecular feedback resulted in an increased IL-8 release and augmented recruitment of polymorphonuclear granulocytes (PMN). Our study suggests the possibility that responses of MSC to multi-cytokine priming regimens may be exploited therapeutically to fine-tune inflammatory activity in tissues. This study elucidates molecular mechanisms underlying the immunological priming of mesenchymal stromal cells (MSC) and their interaction with neutrophils.