Virus reproduction and the time course of changes in liver and kidney functions and in the blood clotting system were studied in the visceral organs of green monkeys and baboons infected with Ebola virus (subtype Zaire). It was shown that monocytes and macrophages were the first cells to be infected with the virus, followed by hepatocytes, adrenocorticocytes, fibroblasts, and endotheliocytes. The early and late pathologic changes in the monkey organs are described. Biochemical data on changes in blood clotting and liver and kidney functions in the course of the infection are presented. The responses of blood clotting and vascular permeability were species specific: Fibrin deposited in blood vessels in green monkeys, while hemorrhages developed in baboons. The results show that species-specific features of monkeys must be taken into account when choosing an experimental model for studying Ebola virus infection. immune complexes, malonic dialdehyde, fibrin, fibrinogen, thrombin, prothrombin, and fibrin degradation products [7][8][9].
Materials and MethodsEBO (subtype Zaire) that was passaged two times in monkeys was used. The virus stock was a 10% suspension of green monkey Results liver, with an activity of 10 5 LD 50 for newborn mice. Suspension was prepared in Eagle MEM with antibiotics.
Target cells for EBO in monkeys. Electron microscopicGreen monkeys (Cercopithecus aethiops), baboons (Papio haexamination showed that monocytes and macrophages were the madryas), and outbred newborn mice were used. Twelve green primary targets for EBO in green monkeys (figure 1). Infected macrophages were first detected in liver sinusoids 2 days after infection. On day 3, infected Kupffer's cells were observed in liver sections. EBO virus reproduction in hepatocytes and adre-
An approach combining virology with light and electron microscopy was used to study the organs of guinea pigs during nine serial passages of Ebola virus, strain Zaire. It was observed that the wild type of Ebola virus causes severe granulomatous inflammation in the liver and reproduces in the cells of the mononuclear phagocyte system (MPS). Based on morphological characterization, two types of virus-cell interactions were demonstrated. The obtained data evidenced for heterogeneity of the population of wild type of Ebola virus. The virus accumulated in the liver of the infected animals, and the lesions became more pronounced with passage. Degenerative changes appeared, and their severity was increased with passage in the other organs as well. The set of target cells diversified and, as a result, not only the MPS cells, but also hepatocytes, spongiocytes, endotheliocytes and fibroblasts became involved in the reproduction of Ebola virus. The possible role of granulomatous inflammation in the development of the adaptive mechanism of Ebola virus to guinea pigs is discussed.
In sharp contrast to human and nonhuman primates, guinea pigs and some other mammals resist Ebola virus (EBOV) replication and do not develop illness upon virus inoculation. However, serial passaging of EBOV in guinea pigs results in a selection of variants with high pathogenicity. In this report, using a reverse genetics approach, we demonstrate that this dramatic increase in EBOV pathogenicity is associated with amino acid substitutions in the structural protein VP24. We show that although replication of recombinant EBOV carrying wild-type VP24 is impaired in primary peritoneal guinea pig macrophages and in the liver of infected animals, the substitutions in VP24 allow EBOV to replicate in guinea pig macrophages and spread in the liver of infected animals. Furthermore, we demonstrate that both VP24/wild type and the guinea pig-adapted VP24/8mc are similar in their ability to block expression of interferon-induced host genes, suggesting that the increase in EBOV virulence for guinea pigs is not associated with VP24 interferon antagonist function. This study sheds light on the mechanism of resistance to EBOV infection and highlights the critical role of VP24 in EBOV pathogenesis.
The review presents modern views about the role of oxidative stress reactions in the pathogenesis of types 1 and 2 diabetes mellitus and their complications based on the analysis of experimental and clinical studies. The sources of increased ROS generation in diabetes are specified, including the main pathways of altered glucose metabolism, oxidative damage to pancreatic β-cells, and endothelial dysfunction. The relationship between oxidative stress, carbonyl stress, and inflammation is described. The significance of oxidative stress reactions associated with hyperglycemia is considered in the context of the “metabolic memory” phenomenon. The results of our studies demonstrated significant ethnic and age-related variability of the LPO—antioxidant defense system parameters in patients with diabetes mellitus, which should be considered during complex therapy of the disease. Numerous studies of the effectiveness of antioxidants in diabetes mellitus of both types convincingly proved that antioxidants should be a part of the therapeutic process. Modern therapeutic strategies in the treatment of diabetes mellitus are aimed at developing new methods of personalized antioxidant therapy, including ROS sources targeting combined with new ways of antioxidant delivery.
Marburg virus (MV) reproduction in organs, hematological and pathological changes were studied by virological and clinical methods, light and electron microscopy in guinea pigs respiratory challenged by the virus. Liver and spleen were most affected by MV, as in parenteral infection. The sequential involvement of cells in virus replication was also the same as in parenteral infection, with monocytoid-macrophagal cells infected first, followed by hepatocytes, spongiocytes, endotheliocytes and fibroblasts. Hemopoietic cells showed evidence of severe damage in respiratory infected guinea pigs. A distinguishing feature of the respiratory infection was close contact of leucocytes with MV infected cells. It is suggested that the entrapment and accumulation of MV in the lungs of respiratory infected guinea pigs makes possible the enfoldment leucocyte attack which does not, however, result in destruction of the infected cells.
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