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Days Post-infection (day + post-infection)
Selected AbstractsA new panel of NS1 antibodies for easy detection and titration of influenza A virus,JOURNAL OF MEDICAL VIROLOGY, Issue 3 2010Zhihao Tan Abstract The non-structural protein NS1 of the influenza A virus is a good target for the development of diagnostic assays. In this study, three NS1 monoclonal antibodies (mAbs) were generated by using recombinant NS1 protein of H5N1 virus and found to bind both the native and denatured forms of NS1. Two of the mAbs, 6A4 and 2H6, bind NS1 of three different strains of influenza A virus, namely H1N1, H3N2, and H5N1. Epitope mapping revealed that residues 42,53 of H5N1 NS1 are essential for the interaction with both mAbs. Between the three strains, there is only one amino acid difference in this domain, which is consistent with the observed cross-reactivities. On the other hand, mAb 1G1 binds to residues 206,215 of H5N1 NS1 and does not bind NS1 of H1N1 or H3N2. Furthermore, all three mAbs detected NS1 proteins expressed in virus infected MDCK cells and indirect immunofluorescence staining with mAbs 6A4 and 2H6 provided an alternative method for viral titer determination. Quantifying the numbers of fluorescent foci units yielded viral titers for three different isolates of H5N1 virus that are highly comparable to that obtained by observing cytopathic effect induced by virus infection. Importantly, this alternative method yields results at 1 day post-infection while the conventional method using cytopathic effect yields results at 3 days post-infection. The results showed that this new panel of NS1 antibodies can detect NS1 protein expressed during viral infection and can be used for fast and easy titration of influenza A virus. J. Med. Virol. 82:467,475, 2010. © 2010 Wiley-Liss, Inc. [source] Dynamics of gonococcal type IV pili during infectionCHEMPHYSCHEM, Issue 9-10 2009Dirk Opitz Abstract Keep that motor running: Type IV pili are among the strongest molecular motors characterized to date. Herein it is reported that pilus motors of the human pathogen Neisseria gonorrhoeae are very active for at least one day post-infection of epithelial cells. They generate force in the range on 70 pN and retract at a higher velocity as compared to abiotic environments (see picture). Type IV pili are important bacterial virulence factors that mediate attachment to mammalian host cells and elicit downstream signals. When adhered to abiotic surfaces, the human pathogen Neisseria gonorrhoeae generates force by retracting these polymeric cell appendages. We recently found that single pili generate stalling forces that exceed 100 pN, but it is unclear whether bacteria generate force once they adhere to their human host cells. Here, we report that pili retract very actively during infection of human epithelial cells. The retraction velocity is bimodal and the high velocity mode persisted at higher forces in contrast to an abiotic environment. Bacteria generate considerable force during infection, but the maximum force is reduced from 120±40 pN on abiotic surfaces to 70±20 pN on epithelial cells, most likely due to elastic effects. Velocity and maximum force of pilus retraction are largely independent of the infection period within 1 h and 24 h post-infection. Thus, the force generated by type IV pili during infection is high enough to induce cytoskeletal rearrangements in the host cell. [source] Transient viral-mediated overexpression of ,-calcium/calmodulin-dependent protein kinase II in the nucleus accumbens shell leads to long-lasting functional upregulation of ,-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate receptors: dopamine type-1 receptor and protein kinase A dependenceEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 7 2010B. F. Singer Abstract Calcium/calmodulin-dependent protein kinase II (CaMKII) activity is necessary for the long-lasting expression of locomotor sensitization and enhanced drug-taking observed in rats previously exposed to psychostimulants. Exposure to these drugs also transiently increases ,CaMKII levels in the nucleus accumbens (NAcc), an effect that, when mimicked by transient viral-mediated overexpression of ,CaMKII in NAcc shell neurons, leads to long-lasting enhancement in locomotor responding to amphetamine and NAcc ,-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate (AMPA). The present experiments characterized the dopamine (DA) dependence of the functional AMPA receptor upregulation observed long after transient overexpression of ,CaMKII. Rats infected with herpes simplex virus-,CaMKII in the NAcc shell showed a transient increase in ,CaMKII levels that peaked at 4 days post-infection and returned to baseline 8 days later. When challenged with AMPA (0.8 nmol/side) in the NAcc shell at 20 days post-infection, these rats showed enhanced locomotion compared with controls. This sensitized locomotor response was blocked when AMPA was coinfused with either the DA type-1 receptor antagonist SCH23390 (0.8 nmol/side) or the protein kinase A inhibitor Rp-cAMPS (80 nmol/side). Neither SCH23390 nor Rp-cAMPS produced locomotor effects when infused by itself into the NAcc shell. Furthermore, these antagonists did not block the acute non-sensitized locomotor response to AMPA observed in control rats. These findings show that transient viral-mediated overexpression of ,CaMKII in neurons of the NAcc shell leads to long-lasting functional upregulation of AMPA receptors that is DA type-1 receptor and protein kinase A dependent. Thus, transient increases in levels of ,CaMKII in the NAcc shell produce long-lasting changes in the way that DA and glutamate interact in this site to generate locomotor behavior. [source] Antibody response to influenza infection of mice: different patterns for glycoprotein and nucleocapsid antigensIMMUNOLOGY, Issue 4 2003Robert Sealy Summary Our previous studies of C57BL/6 mice intranasally infected with influenza virus (A/PR8) revealed a spike of virus-specific immunoglobulin A (IgA)-secreting antibody-forming cells (AFC) in the mediastinal lymph node (MLN) 7 days post-infection. Here we show that these AFC are directed only against viral glycoprotein, and not nucleocapsid antigens. The early IgA spike associates with a decline in glycoprotein-specific AFC during week 2 post-infection. In contrast to the glycoprotein-specific AFC, nucleocapsid-specific, IgA-secreting AFC develop gradually in the MLN and persist for more than 3 weeks post-infection. As peripheral lymph node reactions wane, the nucleocapsid-specific AFC appear as long-sustained populations in the bone marrow. Microanatomical examination of the respiratory tract in infected mice shows foci of infection established in the lung 2 days post-infection, from which virus spreads to infect the entire lining of the trachea by day 3. At this time, viral haemagglutinin can be seen within the MLN, probably on projections from infected dendritic cells. This feature disappears within a day, though viral antigen expression continues to spread throughout the respiratory tract. Total IgA- and IgG-secreting AFC appear histologically in large numbers during the first week post-infection, significantly preceding the appearance of germinal centres (revealed by peanut agglutinin staining in week 2). To explain these results, we suggest that the initial immunogenic encounter of B cells with viral antigens occurs about 3 days post-infection in the MLN, with antigens transported by dendritic cells from airway mucosa, the only site of viral replication. Viral glycoproteins expressed as integral membrane components on the surface of infected dendritic cells [probably in the absence of cognate T helper (Th) cells] promote members of expanding relevant B-cell clones to undergo an IgA switch and terminal local plasmacytoid differentiation. Anti-glycoprotein specificities are thus selectively depleted from progeny of activated B-cell clones which are channelled to participate in germinal centre formation (perhaps by cognate T helper cells when they become sufficiently frequent). One product of the germinal centre reaction is the long-sustained, bone marrow-resident population, which is accordingly rich in anti-nucleoprotein, but not anti-glycoprotein specificities. Of note, we find that AFC responses toward influenza virus and Sendai virus differ, even though viral replication is limited to the airway mucosa in each case. The response towards Sendai virus exhibits neither the early appearance of anti-glycoprotein AFC expressing IgA in draining lymph nodes, nor the subsequent relative deficit of this specificity from bone marrow AFC populations. [source] Morphological features of Murray Valley encephalitis virus infection in the central nervous system of swiss miceINTERNATIONAL JOURNAL OF EXPERIMENTAL PATHOLOGY, Issue 1 2000Vance Matthews We have examined the histological and ultrastructural features of CNS infection with Murray Valley encephalitis (MVE) virus in mice inoculated with a virulent parental strain (BH3479). Light microscopic examination revealed neuronal necrosis in the olfactory bulb and hippocampus of MVE-infected brains by 5 days post-infection (pi). Electron microscopy of these regions showed endoplasmic reticulum membrane proliferation, and tubular and spherical structures in the cisternae of the endoplasmic reticulum, Golgi complex and nuclear envelope. At seven to eight days pi, infected neurones exhibited chromatin condensation and extrusion, nuclear fragmentation, loss of segments of the nuclear envelope, reduced surface contact with adjacent cells and loss of cytoplasmic organelles. This cell injury was particularly noticeable in the proximal CA3 and distal CA1 regions of the hippocampus. The inflammatory cell profile consisted of macrophages, lymphocytes and especially neutrophils, and many of these inflammatory cells were apoptotic. High mortality rates in the BH3479-infected population of mice correlated with the intense polymorphonuclear and mononuclear leucocyte inflammatory infiltrate in the CNS. [source] Strain-dependent activation of the mouse immune response is correlated with Porphyromonas gingivalis -induced experimental periodontitisJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 11 2009Asaf Wilensky Abstract Aims: To evaluate the effect of oral infection with three Porphyromonas gingivalis strains on alveolar bone loss (ABL) and its correlation with the mouse immune response. Materials and Methods: Mice were orally infected with P. gingivalis strains 381, 33277 and 53977. After 42 days, maxillae were analysed for ABL using micro-computed tomography and the serum for anti- P.gingivalis IgG1 and IgG2a levels. The cytokine response to P. gingivalis was tested using the subcutaneous chamber model. Results: The P. gingivalis 53977-infected group showed the highest ABL, which was significantly different from all other groups (p<0.001). In addition, the humoral response to P. gingivalis 53977 was significantly lower than the response to P. gingivalis 381 and 33277 (p0.01). The IgG2a/IgG1 ratio was higher in the P. gingivalis 33277-infected group (1.6) compared with the P. gingivalis 381-infected group (0.51). Four days post-infection, interleukin (IL)-1, levels remained significantly higher in the P. gingivalis 53977-infected group only (1198.2±260.0, p<0.05), while IL-4 levels remained significantly higher in the P. gingivalis 381-infected group (265.8±131.6, p<0.05). Conclusions: The high levels of ABL induced by P. gingivalis 53977 were inversely correlated with the humoral response to this bacterium. In addition, ABL was correlated with an elevated pro-inflammatory response. [source] Pre-exposure to infectious hypodermal and haematopoietic necrosis virus or to inactivated white spot syndrome virus (WSSV) confers protection against WSSV in Penaeus vannamei (Boone) post-larvaeJOURNAL OF FISH DISEASES, Issue 10 2006J Melena Abstract Larvae and post-larvae of Penaeus vannamei (Boone) were submitted to primary challenge with infectious hypodermal and haematopoietic necrosis virus (IHHNV) or formalin-inactivated white spot syndrome virus (WSSV). Survival rate and viral load were evaluated after secondary per os challenge with WSSV at post-larval stage 45 (PL45). Only shrimp treated with inactivated WSSV at PL35 or with IHHNV infection at nauplius 5, zoea 1 and PL22 were alive (4.7% and 4%, respectively) at 10 days post-infection (p.i.). Moreover, at 9 days p.i. there was 100% mortality in all remaining treatments, while there was 94% mortality in shrimp treated with inactivated WSSV at PL35 and 95% mortality in shrimp previously treated with IHHNV at N5, Z1 and PL22. Based on viral genome copy quantification by real-time PCR, surviving shrimp previously challenged with IHHNV at PL22 contained the lowest load of WSSV (0,1 × 103 copies ,g,1 of DNA). In addition, surviving shrimp previously exposed to inactivated WSSV at PL35 also contained few WSSV (0,2 × 103 copies ,g,1 of DNA). Consequently, pre-exposure to either IHHNV or inactivated WSSV resulted in slower WSSV replication and delayed mortality. This evidence suggests a protective role of IHHNV as an interfering virus, while protection obtained by inactivated WSSV might result from non-specific antiviral immune response. [source] Experimental transmission of sleeping disease in one-year-old rainbow trout, Oncorhynchus mykiss (Walbaum), induced by sleeping disease virusJOURNAL OF FISH DISEASES, Issue 5 2006S Kerbart Boscher Abstract Sleeping disease (SD) is a serious disease of rainbow trout, Oncorhynchus mykiss, reared in fresh water caused by sleeping disease virus (SDV). In this study a detailed clinical, histological, virological and serological description of the experimental reproduction of SD in 1-year-old rainbow trout exposed to SDV was carried out. Two hundred disease-free fish were intraperitoneally inoculated with a SDV isolate and 100 fish were inoculated with an uninfected cell culture lysate as a negative control. Infected and control fish were randomly removed at days 4, 7, 14, 21, 42 and 70 post-infection. Blood and tissues were collected for virus isolation, histopathological examination and serum neutralization. SDV was detected in serum, kidney and brain of infected fish from 4 to 21 days post-infection (dpi). Characteristic pathological lesions were observed in infected fish as early as 7 dpi. Lesions were first detected in exocrine pancreas and subsequently observed in heart and skeletal muscle. Neutralizing antibodies to SDV were detected in infected fish from 14 to 70 dpi. Infected fish displayed typical signs of SD 1-month pi and the mortality reached 18.7% within 44 days. This study experimentally reproduced all the pathognomonic features of natural outbreaks of SD in 1-year-old rainbow trout. [source] Detection of nodavirus in barramundi, Lates calcarifer (Bloch), using recombinant coat protein-based ELISA and RT,PCRJOURNAL OF FISH DISEASES, Issue 3 2001Huang The coat protein encoded by the nodavirus RNA2 gene originally isolated from greasy grouper, Epinephelus tauvina, was cloned, expressed as a recombinant polyhistidine-tailed fusion protein and characterized by immunoblot analysis. The purified recombinant protein was used to develop an indirect enzyme-linked immunosorbent assay (ELISA) to detect body exudate and plasma antibodies against the coat protein in both experimentally infected and commercial barramundi. In addition, the nucleotide sequence was employed to develop a RT,PCR detection assay based on the T4 region. The results showed that the virus could be detected as early as 3 days post-infection by RT,PCR while antibodies against the recombinant coat protein were detectable on day 6 post-infection. Among 112 commercial barramundi samples collected from October 1999 to April 2000, 9% showed positive ELISA results which were further verified by Western blot. [source] The effect of temperature and salinity on the settlement and survival of copepodids of Lepeophtheirus salmonis (Krřyer, 1837) on Atlantic salmon, Salmo salar L.JOURNAL OF FISH DISEASES, Issue 5 2000C S Tucker The effects of temperature and salinity on the settlement, subsequent survival and development of the copepodids of Lepeophtheirus salmonis on Atlantic salmon were investigated experimentally. There was a significantly greater settlement and survival of copepodids at 10 days post-infection (dpi) at 12 °C compared with at 7 °C at a constant salinity of 34,. Development of L. salmonis was also more rapid at 12 °C. Settlement was significantly greater at a salinity of 34, than at 24,. In one experiment, survival at 10 dpi was significantly greater at 34,; however, a second experiment found that there was no significant difference between the two saline levels. This may have been because of a rise in water temperature for 2 dpi, which appears to have overridden the effect of low salinity. Development of L. salmonis was more rapid at 34,. Copepodids settled on all of the external surfaces of the salmon, although the proportion on different surfaces varied between experiments. The gills, particularly at low temperatures, the body surface, and the pectoral and dorsal fins were especially favoured. [source] Effects of infection with the ectoparasite Argulus japonicus (Thiele) and administration of cortisol on cellular proliferation and apoptosis in the epidermis of common carp, Cyprinus carpio L., skinJOURNAL OF FISH DISEASES, Issue 3 2000A L Van Der Salm The host-parasite interaction between juvenile carp, Cyprinus carpio, and the ectoparasitic branchiuran, Argulus japonicus, together with the role of cortisol in this interaction, was examined at the level of the host skin epidermis. Epidermal mucous cell numbers, and proliferation and apoptosis of the epithelial cells were studied over 32 days. Apoptotic cell numbers in the uppermost epidermis were reduced at 26 days post-infection with A. japonicus, while the other parameters were unaffected. Administration of cortisol-containing food resulted in reduced apoptosis in the cells in the upper skin epidermis at 24 h and at 28 days post-feeding. Cortisol feeding combined with A. japonicus infection reduced numbers of apoptotic cells in the upper epidermis more than either individual treatment. Further, combining the treatments also significantly increased apoptosis in the lower epidermis in cells morphologically identified as leucocytes apparently migrating macrophages and lymphocytes. Using immunohistochemistry, we demonstrated cortisol receptor presence and cellular localization in the teleost epidermis. Receptors only occurred in pavement cells in the upper epidermis and in leucocytes in the lower parts of the epidermis. The ectoparasites, or administered cortisol, induced effects which may be functionally adaptive in the upper pavement cells, while combining the two treatments also induced changes indicative of immunosuppression. [source] Longitudinal follow up of SIVmac pathogenesis in rhesus macaques of Chinese origin: emergence of B cell lymphomaJOURNAL OF MEDICAL PRIMATOLOGY, Issue 4-5 2002B. Ling Abstract: Two subspecies of rhesus (Rh) macaques, the Chinese (Ch) and Indian (Ind) subspecies were infected intravenously with 100TCID50 SIVmac239. CD4+, CD8+ T cells, plasma viral loads, depletion of intestinal lymphocytes with memory phenotype, humoral immune responses and clinical courses were monitored for 600 days. The pathogenesis of SIVmac was also compared with primary human immunodeficiency virus (HIV) infection of humans. Plasma viral loads in Ch Rh were lower in the acute and chronic phases compared with Ind Rh. SIVmac pathogenesis in Ch Rh was closer to virus loads in untreated HIV infected humans. Ch Rh had higher CD4/CD8 ratios, stronger antibody responses and interestingly, less depletion of intestinal memory CCR5+ CD4+ T lymphocytes compared with Ind Rh. One Ch Rh developed B cell origin lymphoma at 570 days post-infection, the first such report in this subspecies. Three of four Ind Rh developed AIDS within 6 months. The findings indicate that Ch Rh are more resistant to SIVmac pathogenesis compared with Ind Rh and that Ch Rh paralleled HIV-1 infections in untreated adult humans. The SIVmac infected Ch Rh subspecies are an acceptable model for HIV/AIDS. [source] A new panel of NS1 antibodies for easy detection and titration of influenza A virus,JOURNAL OF MEDICAL VIROLOGY, Issue 3 2010Zhihao Tan Abstract The non-structural protein NS1 of the influenza A virus is a good target for the development of diagnostic assays. In this study, three NS1 monoclonal antibodies (mAbs) were generated by using recombinant NS1 protein of H5N1 virus and found to bind both the native and denatured forms of NS1. Two of the mAbs, 6A4 and 2H6, bind NS1 of three different strains of influenza A virus, namely H1N1, H3N2, and H5N1. Epitope mapping revealed that residues 42,53 of H5N1 NS1 are essential for the interaction with both mAbs. Between the three strains, there is only one amino acid difference in this domain, which is consistent with the observed cross-reactivities. On the other hand, mAb 1G1 binds to residues 206,215 of H5N1 NS1 and does not bind NS1 of H1N1 or H3N2. Furthermore, all three mAbs detected NS1 proteins expressed in virus infected MDCK cells and indirect immunofluorescence staining with mAbs 6A4 and 2H6 provided an alternative method for viral titer determination. Quantifying the numbers of fluorescent foci units yielded viral titers for three different isolates of H5N1 virus that are highly comparable to that obtained by observing cytopathic effect induced by virus infection. Importantly, this alternative method yields results at 1 day post-infection while the conventional method using cytopathic effect yields results at 3 days post-infection. The results showed that this new panel of NS1 antibodies can detect NS1 protein expressed during viral infection and can be used for fast and easy titration of influenza A virus. J. Med. Virol. 82:467,475, 2010. © 2010 Wiley-Liss, Inc. [source] Basal replication of hepatitis C virus in nude mice harboring human tumorJOURNAL OF MEDICAL VIROLOGY, Issue 3 2002Patrick Labonté Abstract Hepatitis C virus (HCV) can infect and propagate in humans and chimpanzees. Whereas the chimpanzee has been used as an animal model for infection, ethical considerations, conservation, and the prohibitively high cost preclude progress for experimental research on the biology of the virus. The development of a small animal model for HCV infection is thus desirable to facilitate studies on the infectious cycle of the virus and for the evaluation of drugs for the treatment of HCV infections in humans. As an alternative to the chimpanzee model, we have established a model based on ex vivo infection of orthotopically-implanted human hepatocellular carcinoma cells (HCC) in athymic nude mice. The results show that up to 42 days post-infection, HCV RNA was present in the tumor cells as well as in the liver and serum of infected mice. Furthermore, a direct correlation between size of the tumor and the presence of HCV RNA in the liver was observed, which is concordant with the finding that HCV RNA was detectable only in mice harboring human tumor. Immunohistochemistry analysis of infected liver specimens showed cells expressing the HCV encoded NS5B protein. A few mice developed a humoral response against the nonstructural viral proteins, providing further evidence for expression of these proteins during viral infection. In summary, these results suggest that mice harboring orthotopic tumors support a basal level of HCV replication in vivo. J. Med. Virol. 66:312-319, 2002. © 2002 Wiley-Liss, Inc. [source] Expression of ,re,y luciferase gene in Erwinia amylovoraLUMINESCENCE: THE JOURNAL OF BIOLOGICAL AND CHEMICAL LUMINESCENCE, Issue 4 2003Giovanna Gentilomi Abstract In this study we describe an ef,cient stable genetic transformation of the phytopathogenic bacterium Erwinia amylovora using a recombinant expression vector encoding the ,re,y luciferase gene of Photinus pyralis, which is further controlled by IPTG-inducible promoter. Stably transformed E. amylovora cells maintain the same infectivity as the wild-type strain and, after induction with IPTG, produce luciferase. Luminescence produced by the action of luciferase on an exogenous substrate was easily detectable by a simple and rapid bioluminescent assay (BL). The transformed E. amylovora strain maintains the same high emission level, even after passage in pears, until about 15 days post-infection. Our ,ndings therefore show that the luciferase assay can be conveniently used to follow the bacterial movement in plant tissue and its dissemination in controlled environments. [source] Phlebotomus (Adlerius) halepensis vector competence for Leishmania major and Le. tropicaMEDICAL AND VETERINARY ENTOMOLOGY, Issue 3 2003J. Sádlová Abstract., In Eurasia, phlebotomine sandflies of the subgenus Adlerius (Diptera: Psychodidae) comprise about 20 known species. Some are suspected vectors of visceral leishmaniasis (VL) and at least one species has been implicated as a vector of cutaneous leishmaniasis (CL). We tested Phlebotomus (Adlerius) halepensis Theodor (Jordan strain) for CL vector competence, compared with three standard vectors: Phlebotomus (Phlebotomus) duboscqi N-L. from Senegal, Phlebotomus (Paraphlebotomus) sergenti Parrot from Turkey and the Neotropical Lutzomyia longipalpis (L. & N) (Jacobina strain). Sandfly females were membrane-fed on amastigote suspensions of Leishmania major Y. & S. and Le. tropica (Wright) (Kinetoplastida: Trypanosomatidae) and examined for parasite development 3, 6 and 10 days post-infection. Phlebotomus halepensis showed high susceptibility to both leishmanias, supporting typical suprapylarian parasite development similar to the other vectors. Phlebotomus halepensis infection rates were ,90% for Le. major and ,80% for Le. tropica, with high parasite densities. Development of infections was relatively fast, colonizing the thoracic midgut by 6 days post-bloodmeal in every case and reaching the stomodeal valve in >80% of flies. In late-stage infections, 10 days post-bloodmeal, nearly all P. halepensis females had cardia and stomodeal valve filled with very high numbers of parasites and some Le. tropica -infected females had promastigotes in the pharynx and proboscis. Host choice experiments in the laboratory showed that P. halepensis females fed readily on rat or rabbit and preferred the human forearm. In view of its vector competence and partial anthropophily, we infer that P. halepensis is a potential vector of cutaneous as well as visceral leishmaniases. [source] Differences in immune parameters are associated with resistance to Haemonchus contortus in Caribbean hair sheepPARASITE IMMUNOLOGY, Issue 7 2010K. M. MacKINNON Summary Caribbean hair sheep are more resistant to gastrointestinal nematodes than conventional wool breeds, but mechanisms that confer resistance are not fully understood. This study compared immune effector cell populations and antibody concentrations in 12 hair and 12 wool lambs infected with the abomasal parasite Haemonchus contortus and sacrificed at 3 or 27 days post-infection (p.i.) and 14 uninfected animals of each breed. Faecal egg counts were over 2·5-fold higher (P = 0·12) and packed cell volumes approximately 8% lower (P < 0·10) in infected wool lambs. Abomasal lymph nodes were heavier in infected animals (P < 0·05) and infected hair sheep had larger lymph nodes than infected wool sheep (P < 0·05). Tissue eosinophil concentrations were likewise larger (P = 0·07) in hair compared with wool sheep at 3 days p.i. Circulating levels of IgE and IgA in uninfected lambs were higher in hair sheep (P < 0·05) and during infection, hair sheep had higher serum IgA than wool sheep at 3, 5, and 21 days p.i. (P < 0·05). Serum IgE in infected lambs did not differ between breeds, but concentrations of IgE in lymph nodes were higher (P < 0·01) at 27 days p.i. in infected hair sheep. [source] Enhanced protection by melatonin and meloxicam combination in experimental infection by Trypanosoma cruziPARASITE IMMUNOLOGY, Issue 4 2010L. G. R. OLIVEIRA Summary The aim of this study was to evaluate a possible synergism between melatonin and meloxicam in up-regulating the immune response in male Wistar rats infected with Trypanosoma cruzi during immunosuppression phenomenon, which characterizes the acute phase of the Chagas' disease. Male Wistar rats were infected with the Y strain of T. cruzi. Experiments were performed on 7, 14 and 21 days post-infection. Several immunological parameters were evaluated including ,-interferon (IFN-,), interleukin-2 (IL-2), nitric oxide (NO) and prostaglandin E2 (PGE2). The combined treatment with melatonin and meloxicam significantly enhanced the release of IL-2 and INF-, into animals' serum, when compared with the infected control groups during the course of infection. Furthermore, the blockade of PGE2 synthesis and the increased release of NO by macrophage cells from T. cruzi -infected animals contributed to regulate the production of Th1 subset cytokines significantly reducing the parasitaemia in animals treated with the combination of both substances. Therefore, our results suggest that the association of melatonin and meloxicam was more effective in protecting animals against the harmful actions of T. cruzi infection as compared with the treatments of meloxicam or melatonin alone. [source] Expulsion of the gastrointestinal cestode, Hymenolepis diminuta by tolerant rats: evidence for mediation by a Th2 type immune enhanced goblet cell hyperplasia, increased mucin production and secretionPARASITE IMMUNOLOGY, Issue 1 2007R. A. WEBB SUMMARY The processes underlying expulsion of Hymenolepis diminuta in rats are not known. Expression levels of mRNAs of several cytokines revealed a Th2 response that differed between worm infection levels. IL-4 protein levels decreased while IL-13 levels increased in a 50-worm infection by 30 dpi; the converse was seen with a five-worm infection. A negative correlation was found between IL-4 or IL-13 mRNA expression and worm biomass, between IL-13 protein levels and worm number or worm biomass, and between IL-4 protein levels and worm biomass in 50-worm infections. A negative correlation between IL-4 mRNA or protein expression and worm biomass was observed with five-worm infections. A strong correlation between Muc2 mRNA expression and decreased worm number or biomass in a 50-worm infection was observed. Muc2 protein, goblet cell numbers and mucin decreased in a 50-worm infection by 20 days post-infection. These changes were not seen with five-worm infections where worms are not expelled. The data show that rats infected with 50 H. diminuta mount a Th2 response leading to high levels of IL-13, increased goblet cell numbers and increased mucin2 production and release. The mucus traps the worms, which are progressively expelled from the small intestine. [source] Prion protein is ubiquitinated after developing protease resistance in the brains of scrapie-infected miceTHE JOURNAL OF PATHOLOGY, Issue 1 2004Shin-Chung Kang Abstract Although the key event in the pathology of prion diseases is thought to be the conversion of cellular prion protein (PrPC) to the protease-resistant scrapie species termed PrPSc, the factors that contribute to neurodegeneration in scrapie-infected animals are poorly understood. One probable determinant could be when the accumulation of PrPSc in infected brain overwhelms the ubiquitin,proteasome system and triggers the degenerative cascade. In the present study, it was found that in mouse brains infected with the ME7 scrapie strain, the level of ubiquitin protein conjugates increased significantly at ,144 days post-infection (pi) when clinical signs first become apparent. This elevation correlated with the detection of protease-resistant PrPSc and a decline in two endopeptidase activities associated with proteasome function. However, ubiquitination of PrP was only detected at the terminal stage, 3 weeks after the development of clinical symptoms (,165 days pi). These results suggest that ubiquitination of PrP is a late event phenomenon and this conjugation occurs after the formation of protease-resistant PrPSc. Whether this post-translational modification and the impairment of proteasome function are pivotal events in the pathogenesis of prion diseases remains to be determined. Copyright © 2004 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. [source] Effect of caffeic acid phenethyl ester on treatment of experimentally induced methicillin-resi,stant Staphylococcus epidermidis endophthalmitis in a rabbit modelCELL BIOCHEMISTRY AND FUNCTION, Issue 6 2007Özlem Y Abstract This study investigated the anti-inflammatory effects of caffeic acid phenethyl ester (CAPE), a natural bee-produced compound, and compared it with corticosteroids in the treatment of experimentally induced methicillin-resistant Staphylococcus epidermidis (MRSE) endophthalmitis in addition to intravitreal antibiotics. An experimental endophthalmitis model was produced in 24 New Zealand albino rabbits by unilateral intravitreal injection of 0.1,ml of 4.7,×,104 colony-forming units (CFU) methicillin-resistant S. epidermidis. The animals were then divided randomly into three treatment groups and a control group, group 1 (six rabbits), received only intravitreal vancomycin (1.0,mg/0.1,ml); group 2 (six rabbits), received both intravitreal vancomycin (1.0,mg/0.1,ml) and intravitreal dexamethasone (400,µg/0.1,ml) and group 3 (six rabbits), received both intravitreal vancomycin (1.0,mg/0.1,ml) and subtenon CAPE (10,mg/0.3,ml) after 24,h post-infection. No treatment was given to the control group. Treatment efficacy was assessed by clinical examination, vitreous culture and histopathology. There were no statististically significant differences between clinical scores of all groups in examinations at 24 and 48,h post-infection (p,=,0.915 and p,=,0.067 respectively), but in examinations at 72,h post-infection and after 7 days post-infection, although the clinical scores of treatment groups were not significantly different from each other, they were significantly lower than the control group (p,<,0.05). The culture results of all groups were sterile. As a result, CAPE was found to be as effective as dexamethasone in reducing inflammation in the treatment of experimental MRSE endophthalmitis when used with antibiotics. More studies are needed to determine the optimal administration route and effective dosage of this compound. Copyright © 2006 John Wiley & Sons, Ltd. [source] Differential regulation of nitric oxide synthase isoforms in experimental acute Chagasic cardiomyopathyCLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 1 2000B. Chandrasekar We have previously demonstrated induction and high level expression of IL-1,, IL-6 and tumour necrosis factor-alpha in the myocardium during the acute stage of experimental Trypanosoma cruzi infection (Chagas' disease). The myocardial depressive effects of these cytokines are mediated in part by the induction of nitric oxide synthase (NOS), production of nitric oxide (NO) and formation of peroxynitrite. In this study we investigated the expression, activity and localization of NOS isoforms, and the levels of NO, malondialdehyde (a measure of oxidative stress), and peroxynitrite in rats at 1·5, 5, 10 and 15 days after infection with T. cruzi trypomastigotes. The myocardial inflammatory infiltrate and number of amastigote nests increased over the course of infection. A significant increase in tissue nitrate + nitrite levels, NOS2 mRNA, and NOS2 enzyme activity was observed at all time points in the infected compared with uninfected animals. The enzyme activity of constitutive NOS, tissue malondialdehyde levels, and NOS3 mRNA levels was only transiently increased after infection. The protein levels of the NOS isoforms paralleled their mRNA expression. While no positive nitrotyrosine immunoreactivity was detected in control myocardium, its levels increased in infected animals over time. Thus, by 1·5 days post-infection, when no parasite or immune cell infiltration could be detected, the myocardium expressed high levels of NOS and NO metabolites. Nevertheless, the early production of NO in the myocardium was not sufficient to clear the parasites. [source] | ||||||||||||||||