Serum lipid abnormalities in a chemical/viral mouse model for Reye's syndrome

Neonatal mice given nontoxic dermal applications of an industrial surfactant, Toximul MP8 (Tox), and subsequently infected with sublethal doses of mouse-adapted human Influenza B (Lee) virus (FluB) develop many of the biochemical features of Reye's Syndrome (RS). To determine whether these also include abnormal circulating lipid, we examined serum lipid profiles in the mouse model throughout the treatment course using Iatroscan-TH10. Following 10 days of exposure to surfactant, serum phospholipid and cholesterol levels were significantly reduced relative to control animals. These reductions were transient; however, four days following virus administration, significant differences in serum lipid were again evident. These abnormalities coincided and correlated with increased animal mortality. Animals that received combined Tox + virus treatment had significant decreases in serum total lipids relative to control animals, a reflection of a reduction in all lipid classes, including phospholipid, cholesterol, neutral glycerides (triglycerides plus diglycerides) and free fatty acids. Phospholipid (specifically phosphatidylcholine and lysophosphatidylcholine) and free fatty acid levels in the Tox + virus group were also significantly lower than those in animals that received virus alone. This study has demonstrated that suckling mice given chemical/viral treatment have the serum hypopanlipidemia but not the freefattyacidemia that are characteristic of RS.     

Hepatic lipid abnormalities in a chemical/viral mouse model for Reye's Syndrome

We have examined hepatic lipid profiles in a mouse model for Reye's Syndrome (RS) in which young animals are exposed to nontoxic doses of an industrial pesticide emulsifier and subsequently are infected with sublethal doses of mouse-adapted human Influenza B (Lee) virus (FluB). The purpose of this study was to determine whether liver lipid content was altered in the mice, the time course of any changes, and whether lipid changes were consistent with liver pathology. Neonatal mice exposed dermally to the emulsifier, Toximul MP8 (Tox), had significantly elevated levels of hepatic cholesterol, with otherwise normal lipid composition. Subsequent inoculation of the mice with FluB significantly increased mortality rate. The combined Tox+FluB treatment had several significant effects on liver lipids, including a transient increase in phospholipid (PL) content, a reduction in neutral glycerides and persistently high cholesterol levels. Abnormalities in fatty acid profiles included an apparent elevation in medium chain fatty acids and increased ratios of PL arachidonic to docosahexaenoic acids. Histologically, there was no evidence of fat accumulation in the liver; however, hepatic mitochondria had severe structural abnormalities characteristic of RS. These studies demonstrate that chemical-dependent enhancement of viral virulence is associated with significant alterations of hepatic lipids. We believe that these abnormalities are related to mitochondrial structural damage in RS despite the absence of hepatic steatosis.     

Studies on anti-tumor and antimetastatic activities of fullerenol in a mouse breast cancer model

The purpose was to examine the anti-tumor and antimetastatic activities of fullerenol and their related mechanisms. Thirty EMT-6 tumor-bearing mice were injected intraperitoneally with 0.1 ml saline or 0.1 ml saline containing fullerenol C₆₀(OH)₂₀ (0.08 and 0.4 mg/ml) daily for 16 days. Using tumor tissues, we investigated imbalances in the oxidative defense system and the expression of several angiogenesis factors. C₆₀(OH)₂₀ exhibits anti-tumor and antimetastatic activities in EMT-6 breast cancer metastasis model. Treatment with C₆₀(OH)₂₀ was found to modulate oxidative stress significantly. The expression of several angiogenesis factors was reduced in tumor tissues after treatment with fullerenol. Importantly, CD31 (also known as PECAM-1, platelet endothelial cell adhesion molecule) expression and vessel density were markedly reduced in tumors from fullerenol-treated mice compared with controls. Modulation of oxidative stress in tumor tissues, inhibition of the formation of angiogenesis factors, and subsequent reduction in tumor vessel density and the nutrient supply to tumor cells could be important mechanisms by which fullerenol aggregates inhibit tumor growth and suppress carcinoma metastasis in vivo.     

Interleukin-12 is not essential for silicosis in mice

Background  

Silicosis features foci of inflammation where macrophages and lymphocytes precede and accompany fibroblast proliferation, alveolar epithelial hyperplasia, and increased deposition of connective tissue matrix material. In the mouse following silica inhalation there is recruitment of natural killer-, B-, and CD4⁺ and CD8⁺ lymphocytes to the alveolar spaces, enlargement of bronchial-associated lymphoid tissues (BALT), and aggregation of lymphocytes surrounding small airways and blood vessels. A substantial fraction of the recruited lung lymphocytes produce interferon-γ (IFN-γ), and IFN-γ gene-deleted mice develop less silicosis than wild-type mice. Interleukin-12 (IL-12) is an important pathway for driving the adaptive immune response towards a TH1-like phenotype. We hypothesized that IL-12 might stimulate lymphocyte activation and the up-regulation of IFN-γ, and consequently be an essential mediator for silicosis.     

Magnesia blocks formed on a 3000-ton hydraulic press

Conclusions A production line containing a 3000-ton hydraulic press is used for manufacturing unfired chrome magnesite and forsterite concrete blocks for repairing the lining of heat-consuming plant by mechanical means.An analysis was carried out of the variation of the properties and chemical composition through the block and with the heat treatment temperature, and of the deformation and thermophysical properties and slag resistance of the blocks. The blocks can be recommended as lining material for the walls of the slag pockets and vertical channels of open-hearth furnaces of varied capacity, and for the floor and lower part of the walls of soaking pits.With these blocks the process of lining metallurgical equipment can be mechanized, labor productivity is higher, and the useful life of the individual lining elements longer. The savings achieved from using the blocks as lining material amount to 13–15 rubles/ton blocks.Translated from Ogneupory, No. 6, pp. 4–9, June, 1976.     

森林脑炎病毒不同感染途径对小鼠模型的感染性分析

目的分析森林脑炎病毒不同感染途径对小鼠模型的致病性、病毒分布及增殖动态。方法将适应原代地鼠肾(primary hamster kidney,PHK)细胞的森林脑炎病毒进行10倍系列稀释,取4个连续稀释度的病毒液,分别通过脑腔注射、灌胃、滴鼻、肌肉注射、腹腔注射的感染方式,对昆明小鼠进行攻毒,逐日连续观察14 d,计算半数致死量(median lethal dose,LD₅₀);并分别取攻毒后第3、5、7天发病典型的腹腔感染组小鼠脑、肺、肾脏、肝脏、心脏、小肠、血液7种组织器官,采用蚀斑法检测病毒滴度。结果脑腔、灌胃、滴鼻、肌肉注射和腹腔注射攻毒方式的LD₅₀分别为10、10^5.1、10⁵、10^1.2和10²PFU/mL。所有攻毒途径小鼠的脑腔中病毒滴度最高,达10⁹PFU/mL,肺组织为10^6.5PFU/mL,肾脏为10⁵PFU/mL,心脏和肝脏中病毒滴度较低,分别为10²     

Highly efficient ceramic catalytic blocks with a honeycomb structure

Compositions and technologies are suggested for preparing highly efficient catalyst blocks with a honeycomb structure to be used for reducing nitrogen oxides with ammonia in flue gases from thermal power plants. The blocks have high structural strength and catalytic activity.     

Testing carbon blocks in the iron runner channel of a blast furnace

Conclusions The physical properties of worked carbon blocks correspond to the technical conditions for carbon blocks before their operation.Tests and investigations made show the advantages of widely using carbon-block linings in blast-furnace runners.It is necessary to develop a special design for runners with block linings which will ensure reliable fitting of the blocks, since the existing design of runners does not do away with the danger of floating.Iron runners should be lined with large blocks and the joints filled with carbon paste.After each iron tapping it is necessary to apply a protective coating of grog-clay or clay paste to the block lining by mechanical means with the aim of reducing the oxidation of the blocks when they react with atmospheric oxygen.Restorative repairs of the lining of the runners should be done by applying grog-carbon or purely carbon bodies to the repaired place.Production of carbon blocks for lining blast-furnace runners should be organized in plant conditions.     

Tests on dinas concrete blocks in soaking pits of a blooming mill

Conclusions Dinas brick in the lining of soakingpits at 1400 – 1450 showed the same resistance as dinas brick, to the separating wall under the refractory layer the dinas concrete did not fuse and after 8 months of service was still suitable for further use.Temperature measurements show that the surface of the brickwork below the refractory lining heats up to 1200. This excludes the possibility of using heat-resistant concrete with a portland cement base and a chamotte filler in the brickwork of the basic walls of pits.Dinas concrete blocks can be used to replace dinas brick in the working lining of soaking pits and chamotte in the     

同型半胱氨酸致神经管畸形小鼠模型的建立及其作用机制

目的 建立同型半胱氨酸(homocysteine,Hcy)致神经管畸形(neural tube defect,NTD)的小鼠模型,并探讨其作用机制.方法 以单独使用同型半胱氨酸硫代内酯(homocysteine thiolactone,HTL)及联合胱硫醚-β-合成酶(cystathio-nine-β-synthase...     

Capillary alginate gel (Capgel™) for the treatment of full-thickness dermal wounds in a hypoxic mouse model

Abstract

In this study, capillary alginate gel (Capgel^?), a collagen and alginate based self-assembling biomaterial, was used as a cellular scaffold for the treatment of ischemic, full-thickness dermal wounds in mice. Capgel^? was synthesized using copper sulfate to form the initial sol before rinsing and stabilizing the patent capillary structures with carbodiimide chemistry. This crosslinked hydrogel was then injected into ischemic, full-thickness dermal wounds and analyzed via histology after 7 and 10 days to assess wound contracture, granulation bed tissue and vascular structures. Capgel^? showed good resorbability and was well-invested with infiltrating host cells and vascular structures during and after resorption.     

Effect of antioxidant in an acute lung injury animal model

The objective of this study was to scrutinize the involvement of nitric oxide (NO) and the diagnosis of blood in ARDS in a rat model determined by the sequential exposure to lipopolysaccharide (LPS). Also, the present study was designed to evaluate the effects of taurine and dexamethasone on ARDS induced by LPS. Measurements of nitrite/nitrate were elevated in BAL of LPS challenged rats, indicative of an induction of the NO synthase. Taurine and dexamethasone abrogated the extent of endotoxin-induced ARDS, as evidenced by the decreases BAL nitrate/nitrite, BALF protein and lung pathology. T+L+D-group had higher PaO₂ and lower PaCO₂ values than L-group and T+Lgroup. But, ionized Ca²⁺ and Mg²⁺ both were not shown significant change. Also, T+L and T+L+D-group showed significant increase compared with L-group, but for the other side no significant difference was seen between T+L and T+L+D group. We suggest that taurine and dexamethasone may be a drug of choice for preventing ARDS.     

Acute exposure to silica nanoparticles enhances mortality and increases lung permeability in a mouse model of Pseudomonas aeruginosa pneumonia

Background

The lung epithelium constitutes the first barrier against invading pathogens and also a major surface potentially exposed to nanoparticles. In order to ensure and preserve lung epithelial barrier function, the alveolar compartment possesses local defence mechanisms that are able to control bacterial infection. For instance, alveolar macrophages are professional phagocytic cells that engulf bacteria and environmental contaminants (including nanoparticles) and secrete pro-inflammatory cytokines to effectively eliminate the invading bacteria/contaminants. The consequences of nanoparticle exposure in the context of lung infection have not been studied in detail. Previous reports have shown that sequential lung exposure to nanoparticles and bacteria may impair bacterial clearance resulting in increased lung bacterial loads, associated with a reduction in the phagocytic capacity of alveolar macrophages.

Results

Here we have studied the consequences of SiO₂ nanoparticle exposure on Pseudomonas aeruginosa clearance, Pseudomonas aeruginosa-induced inflammation and lung injury in a mouse model of acute pneumonia. We observed that pre-exposure to SiO₂ nanoparticles increased mice susceptibility to lethal pneumonia but did not modify lung clearance of a bioluminescent Pseudomonas aeruginosa strain. Furthermore, internalisation of SiO₂ nanoparticles by primary alveolar macrophages did not reduce the capacity of the cells to clear Pseudomonas aeruginosa. In our murine model, SiO₂ nanoparticle pre-exposure preferentially enhanced Pseudomonas aeruginosa-induced lung permeability (the latter assessed by the measurement of alveolar albumin and IgM concentrations) rather than contributing to Pseudomonas aeruginosa-induced lung inflammation (as measured by leukocyte recruitment and cytokine concentration in the alveolar compartment).

Conclusions

We show that pre-exposure to SiO₂ nanoparticles increases mice susceptibility to lethal pneumonia but independently of macrophage phagocytic function. The deleterious effects of SiO₂ nanoparticle exposure during Pseudomonas aeruginosa-induced pneumonia are related to alterations of the alveolar-capillary barrier rather than to modulation of the inflammatory responses.

Electronic supplementary material

The online version of this article (doi:10.1186/s12989-014-0078-9) contains supplementary material, which is available to authorized users.