Iron mobilization in three animal models of inflammation

The effect of acute, subchronic, and chronic experimental models of inflammation upon hematocrit, hemoglobin, serum iron and ferritin iron and nonheme iron concentration in the liver and spleen has been studied in the rat. In the acute model (carrageenan oedema) no iron mobilization took place, whereas in the chronic models differences in iron mobilization were observed, related to their different chronicity and to the time elapsed from induction. The carrageenan-induced granuloma (from 12 h to 8 days) (subchronic model) was accompanied by a decrease of plasma iron (12 and 24 h), a later decrease of the hematocrit values (2 and 4 days) and high ferritin and nonheme iron concentrations in the liver and spleen for 4 days, followed by a tendency to return to the control values. The anemia in the adjuvant arthritis (from 1 to 4 weeks after induction) (chronic model) was observed at 7 days and is related to increased iron stores in the liver and spleen. However, the iron store levels in liver decreased and fell later below control values. The increase of ferritin and nonheme iron concentrations may be responsible for the reduced availability of iron release from tissue.     

Respiratory muscle injury in animal models and humans

Respiratory muscle injury may result from excessive loading due to a decrease in respiratory muscle strength, an increase in the work of breathing, or an increase in the rate of ventilation. Other conditions such as hypoxemia, hypercapnia, aging, decreased nutrition, and immobilization may potentiate respiratory muscle injury. Respiratory muscle injury has been shown in animal models using direct muscle or phrenic nerve stimulation, acute inspiratory resistive loading, tracheal banding, corticosteroids, phrenic nerve section, and the mdx mouse. Although numerous examples of diaphragm injury have been shown in animal models, evidence in humans is sparse. Potential mechanisms which may contribute to respiratory muscle injury include high levels of intracellular calcium-activated degradative enzymes, non-uniformity of stresses and strains, plasma membrane disruptions, and activation of the inflammatory process.     

Anidulafungin: experimental therapy of fungal infections in animal models

We have reviewed the existing data on the efficacy of anidulafungin, which is the most recent echinocandin in the experimental treatment of fungal infections. The scarce published data practically only refers to disseminated and pulmonary aspergillosis and to disseminated candidiasis. Anidulafungin shows fungistatic activity against Aspergillus fumigatus, and fungicidal activity against Candida albicans and Candida glabrata.     

丙型肝炎病毒感染实验动物模型的研究进展

丙型肝炎病毒（HCV）感染是导致人类慢性病毒性肝炎、肝硬化和肝癌的最主要病因之一。由于缺乏合适的HCV感染实验动物模型,使得针对HCV感染更为有效的疗法及疫苗的研发滞后。黑猩猩是HCV感染研究的最佳实验动物,但由于其来源有限、价格昂贵及临床症状等诸多问题,其应用受限,因此发展新的实验动物模型用于HCV感染相关的基础和应用研究迫在眉睫。近年来,以啮齿类等动物为替代模型取得了不少进展,应用转基因等实验技术使替代动物感染了HCV,并成功应用于多个学科领域的研究。本文分析了HCV自然感染的实验动物、自然感染和非自然感染的替代实验动物在致病机制研究、药物评价和疫苗研发应用中的优缺点及未来研究趋势。     

Imaging of experimental osteoarthritis in small animal models

Normally, tissue alterations in small animal models for osteoarthritis (OA) are assessed by time-consuming and destructive histology or biochemical assays. Some high resolution imaging modalities are used for longitudinal monitoring of the OA disease process in vivo. microCT is one of these imaging modalities, which is known for superb high-resolution imaging of bone architecture alterations. A major drawback of microCT is that it has low soft-tissue contrast, which makes direct imaging of cartilage impossible. The use of microCT in combination with negatively charged radiopaque contrast agents enables imaging of cartilage degeneration. We demonstrate the possibility of microCT to image cartilage degeneration as a consequence of experimental OA, by the use contrast enhanced microCT in vivo in a rat model for OA. Furthermore, for the assessment of alterations in molecular processes involved in OA we used the recently developed technique of multi pinhole SPECT. This enables us to assess molecular processes involved in experimental OA in a rat at sub-millimeter level. Here we show quantification of subchondral bone turnover in an OA rat knee. These new techniques demonstrate the possibilities of quantitative experimental OA assessment in small animal models such as mice and rats and might enable substitution of the conventional destructive methods.     

Cellular and molecular pathogenesis of systemic lupus erythematosus: lessons from animal models

Systemic lupus erythematosus (SLE) is a complex disease characterized by the appearance of autoantibodies against nuclear antigens and the involvement of multiple organ systems, including the kidneys. The precise immunological events that trigger the onset of clinical manifestations of SLE are not yet well understood. However, research using various mouse strains of spontaneous and inducible lupus in the last two decades has provided insights into the role of the immune system in the pathogenesis of this disease. According to our present understanding, the immunological defects resulting in the development of SLE can be categorized into two phases: (a) systemic autoimmunity resulting in increased serum antinuclear and antiglomerular autoantibodies and (b) immunological events that occur within the target organ and result in end organ damage. Aberrations in the innate as well as adaptive arms of the immune system both play an important role in the genesis and progression of lupus. Here, we will review the present understanding - as garnered from studying mouse models - about the roles of various immune cells in lupus pathogenesis.     

Animal models of ischemic stroke: balancing experimental aims and animal care

Animal models of ischemic stroke are examples of an induced model that can present challenges from the perspectives of protocol review and animal management. The review presented here will include a brief summary of the current state of knowledge about clinical stroke; a general synopsis of important unanswered research questions that justify use of animal stroke models; an overview of various animal models of ischemic stroke, including strengths and limitations; and a discussion of animal care issues relative to ischemic stroke models. Good communication and interactive education among primary investigators, laboratory animal veterinarians and caretakers, and institutional animal care and use committee members are critical in achieving a balance between research objectives and animal care issues when using animal stroke models.     

Effect of ricinoleic acid in acute and subchronic experimental models of inflammation

Observational studies indicate that topical application of ricinoleic acid (RA), the main component of castor oil, exerts remarkable analgesic and anti-inflammatory effects. Pharmacological characterization has shown similarities between the effects of RA and those of capsaicin, suggesting a potential interaction of this drug on sensory neuropeptide-mediated neurogenic inflammation. The aim of this study was to assess RA anti-inflammatory activities in comparison with capsaicin in several models of acute and subchronic inflammation. The acute inflammation was induced by intradermal injection of carrageenan in the mouse or by histamine in the guinea-pig eyelid. In either experiment, the extent of the oedema thickness was measured. Subchronic oedema was induced by complete Freund's adjuvant injection in the ventral right paw of mice. Tissue substance P (SP) was measured in the carrageenan experiments by radioimmunoassay (RIA). It was found that the acute topical application of RA (0.9 mg/mouse) or capsaicin (0.09 mg/mouse) significantly increased the mouse paw oedema induced by carrageenan, while an 8-day repeated topical treatment with the same doses of both compounds resulted in a marked inhibition of carrageenan-induced paw oedema matched by a reduction in SP tissue levels. Similar effects were found against histamine-induced eyelid oedema in guinea-pigs after acute or repeated application of RA or capsaicin. RA and capsaicin given for 1-3 weeks reduced the established oedema induced by Freund's adjuvant, a subchronic model of inflammation, particularly if given by the intradermal route. Either in mouse paw or in guinea-pig eyelid, capsaicin but not RA by itself produced a slight hyperemia and activation of a behavioural response (e.g. scratching of the eyelids). On the basis of the present results, RA may be seen as a new capsaicin-like, non-pungent anti-inflammatory agent suitable for peripheral application.     

Periods of systemic partial hypoxia induces apoptosis and inflammation in rat skeletal muscle

Critical illness myopathy (CIM) causes significant morbidity. In this study, we investigated the effect of repeated mild hypoxia on the skeletal muscle inflammation. Sprague–Dawley rats anesthetized with 2% inhaled isoflurane were divided into two groups (n = 6 each), normoxia and hypoxia (12.5% for 12 min followed by 35% for 12 min, at which point the cycle was repeated for three times). We measured the tissue oxygen tension and perfusion (simultaneously) in hind limb skeletal muscle. Inflammation in skeletal muscle was assessed by light microcopy (Hematoxylin-Eosin staining) and apoptosis (Fluorescein-FragEL DNA fragmentation detection) and expressed as percent normoxia. Compared to the control group, hypoxia significantly (P < 0.001) altered histomorphometrics. Similarly, DNA fragmentation analysis revealed that hypoxia significantly (P < 0.001) induced apoptosis. We conclude that after a mild but repeated hypoxic insult there is marked histological alterations and induced apoptosis in skeletal muscle. We postulate that variable periods of hypoxia in the critically ill may be playing a role in the etiology of CIM.     

Ultrastructural study of experimental muscle degeneration and regeneration in the adult rat

Summary Methyl-bupivacaine is a local anaesthetic with a selective myotoxic action. A single subcutaneous injection of the drug into the hind leg of adult rats produces a uniform, complete and irreversible destruction of superficial layers of fibres in the underlying extensor digitorum longus muscle. The degeneration of muscle fibres is followed by phagocytosis and a rapid and complete regeneration.The first stage in the regeneration process is the appearance of presumptive myoblasts within the original basement membrane of the sarcolemmal tube. On the second day after injury aggregates of myoblasts are present and fusion is observed between the cells. The myotubes thus formed increase in size by fusing with additional myoblasts. Myotubes are also observed to fuse with one another. On the fifth day after injury the regeneration process has proceeded to the stage of early muscle fibres with fully differentiated myofibrils with typical sarcomere structures. By ten days only mature muscle fibres of about normal size are present and regeneration appears complete.In previously denervated and methyl-bupivacaine treated muscles the stages of regeneration are similar to those observed in innervated muscles, the only apparent difference being a slowing of cell differentiation and incomplete maturation.An electrophysiological study shows that the motor nerve at the third day after injury forms synaptic contacts with regenerating muscle cells. At that stage of myogenesis the myotubes are highly sensitive to applied acetylcholine.1 (1-n-butyl-DL-piperidine-2-carboxylic acid-2,6-dimethyl-anilide-hydrochloride); Marcaine®, manufactured by AB Bofors, Nobel-Pharma, Mölndal, Sweden.The study was carried out under the auspicies of The Czechoslovak Academy of Sciences and the Royal Academy of Sciences in Sweden.     

Effect of incremental exercise on airway and systemic inflammation in patients with COPD

Airway and systemic inflammation are features of chronic obstructive pulmonary disease (COPD), and there is growing interest in clarifying the inflammatory processes. Strenuous exercise induces an intensified systemic inflammatory response in patients with COPD, but no study has investigated the airway inflammatory and anti-inflammatory responses to exercise. Twenty steroid-na?ve, ex-smokers with diagnosed COPD (forced expired volume in 1 s = 66 ± 12%) underwent baseline collection of venous blood and induced sputum followed by an incremental exercise test to symptom limitation 48 h later. Additional venous blood samples were collected following exercise at 0, 2, and 24 h, while induced sputum was collected 2 and 24 h after exercise. Sputum and blood samples were analyzed for differential cell count, CD4(+) and CD8(+) T lymphocytes (serum only), interleukin (IL)-6, IL-8, IL-10, chemokine (C-C motif) ligand 5 (CCL5), and high sensitivity C-reactive protein (serum only). There was an increase in the number of sputum eosinophils (cells/gram, P = 0.012) and a reduction in sputum IL-6 (P = 0.01) 24 h postexercise. Sputum IL-8 and CCL5 were also persistently decreased after exercise (P = 0.0098 and P = 0.0012, respectively), but sputum IL-10 did not change. There was a decrease in serum eosinophils 2 h after exercise (P = 0.0014) and a reduction in serum CCL5 immediately following and 2 h postexercise (P < 0.0001). Both serum eosinophils and CCL5 returned to baseline levels within 24 h. An acute bout of exercise resulted in a significant increase in the number of sputum eosinophils, which may be mediated by serum CCL5. However, there was also a reduction in sputum proinflammatory cytokines, suggesting some anti-inflammatory effect of exercise in the lungs of steroid-na?ve patients with COPD.     

Functional characteristics of dystrophic skeletal muscle: insights from animal models.

Muscular dystrophies are a clinically and genetically heterogeneous group of disorders that show myofiber degeneration and regeneration. Identification of animal models of muscular dystrophy has been instrumental in research on the pathogenesis, pathophysiology, and treatment of these disorders. We review our understanding of the functional status of dystrophic skeletal muscle from selected animal models with a focus on 1) the mdx mouse model of Duchenne muscular dystrophy, 2) the Bio 14.6 delta-sarcoglycan-deficient hamster model of limb-girdle muscular dystrophy, and 3) transgenic null mutant murine lines of sarcoglycan (alpha, beta, delta, and gamma) deficiencies. Although biochemical data from these models suggest that the dystrophin-sarcoglycan-dystroglycan-laminin network is critical for structural integrity of the myofiber plasma membrane, emerging studies of muscle physiology suggest a more complex picture, with specific functional deficits varying considerably from muscle to muscle and model to model. It is likely that changes in muscle structure and function, downstream of the specific, primary biochemical deficiency, may alter muscle contractile properties.     

Animal models of infection and inflammation and their role in experimental nuclear medicine

In this review, basic aspects of nuclear medicine are described. One of the fields of research in nuclear medicine is the development of new radiopharmaceuticals for imaging infection and inflammation in humans. For this development, animal models are identified and modified to needs of a particular research question. In this review, a wide variety of models that are available in our laboratory are presented and the strengths and pitfalls are discussed.     

Inhibition of AMPK expression in skeletal muscle by systemic inflammation in COPD rats

Background

Analysis of exhaled breath condensates (EBC) is a non-invasive technique to evaluate biomarkers such as antioxidants in the pediatric population, but limited data exists of its use in intubated patients, particularly newborns. Currently, tracheal aspirate (TA) serves as the gold standard collection modality in critically ill newborns, but this method remains invasive. We tested the hypothesis that glutathione status would positively correlate between EBC and TA collections in intubated newborns in the Newborn Intensive Care Unit (NICU). We also hypothesized that these measurements would be associated with alveolar macrophage (AM) glutathione status in the newborn lung.

Methods

Reduced glutathione (rGSH), glutathione disulfide (GSSG), and total GSH (rGSH + (2 X GSSG)) were measured in sequential EBC and TA samples from 26 intubated newborns via high performance liquid chromatography (HPLC). Additionally, AM glutathione was evaluated via immunofluorescence. Pearson’s correlation coefficient and associated 95% confidence intervals were used to quantify the associations between raw and urea-corrected concentrations in EBC and TA samples and AM staining. Statistical significance was defined as p ≤ 0.05 using two-tailed tests. The sample size was projected to allow for a correlation coefficient of 0.5, with 0.8 power and alpha of 0.05.

Results

EBC was obtainable from intubated newborns without adverse clinical events. EBC samples demonstrated moderate to strong positive correlations with TA samples in terms of rGSH, GSSG and total GSH. Positive correlations between the two sampling sites were observed in both raw and urea-corrected concentrations of rGSH, GSSG and total GSH. AM glutathione staining moderately correlated with GSSG and total GSH status in both the TA and EBC.

Conclusions

GSH status in EBC samples of intubated newborns significantly correlated with the GSH status of the TA sample and was reflective of cellular GSH status in this cohort of neonatal patients. Non-invasive EBC sampling of intubated newborns holds promise for monitoring antioxidant status such as GSH in the premature lung. Further studies are necessary to evaluate the potential relationships between EBC biomarkers in the intubated premature newborn and respiratory morbidities.     

Inhibition of AMPK expression in skeletal muscle by systemic inflammation in COPD rats

Background

Chronic obstructive pulmonary disease (COPD) is a disease characterized by airflow limitation and inflammation. Meanwhile, COPD also is associated with metabolic disorders, such as skeletal muscle weakness. Strikingly, activation of AMP-activated protein kinase (AMPK) exerts critical roles in energy metabolism. However, it remains unclear whether and how the expression levels of AMPK are affected in the COPD model rats which may lead to the dysfunction of the skeletal muscle in these rats.

Methods

Here we developed a rat model of COPD, and we investigated the morphological changes of peripheral skeletal muscle and measured the levels of tumor necrosis factor -α (TNF-α) and AMPK in skeletal muscle by using approaches that include immunohistochemistry and polymerase chain reaction (PCR).

Results

We found that the expression levels of both AMPK mRNA and protein in skeletal muscles were significantly reduced in the COPD model rats, in comparison to those from the control rats, the COPD model rats that received treatments with AICAR and resveratrol, whereas the expression levels of TNF-α were elevated in COPD rats.

Conclusion

Such findings indicate that AMPK may serve as a target for therapeutic intervention in the treatment of muscle weakness in COPD patients.     

实验性自身免疫性心肌炎动物模型的建立与评价

实验性自身免疫性心肌炎动物模型（ experimental autoimmune myocarditis, EAM）作为自身免疫性心肌炎机制、诊断、药物治疗等实验研究的重要载体,在心肌炎科学研究中发挥着重要的作用。本文针对EAM模型的建立及评价予以综述,分别对心肌自身抗原、心肌自身抗原表位、活化自身免疫细胞、干酪乳杆菌细胞壁成分等介质诱导的EAM模型进行整理总结,分析比较各造模方法的特点并阐述EAM模型的评价方法,为建立客观的EAM模型提供有效依据。