"FoxP3 Hunting" during infection with Francisella tularensis

Francisella tularensis is a Gram-negative intracellular bacterium that can cause acute disease in mouse models of infection when administered via the inhalational route. The immune response to a pulmonary infection is typified by an initial lack of pro-inflammatory cytokines, followed by hypercytokinemia prior to host death. It remains unclear what causes this delay in the host immune response. In this study we determine the presence of FoxP3 regulatory T cells in the lung, liver and spleen following intranasal infection with F. tularensis SCHU S4. In the lung, the site of initial infection, there is an increase in FoxP3+ cells during the first few days of infection and a notable absence of these cells at the point of cytokine storm and death (day 4 post-infection). This coincides with a decrease in the anti-inflammatory cytokine TGF-β and increases of chemokines MIP-1α, MIP-1β and RANTES. In our model, we also observed an overall decrease in the number of regulatory T cells in the spleen, which was not as evident in the liver. Overall, this data suggests that early on in an acute F. tularensis SCHUS4 infection regulatory T cells contribute to a dampening of the pro-inflammatory response, allowing for bacterial replication and spread.

Cytokine Expression at Different Stages of Influenza A(H1N1)pdm09 Virus Infection in the Porcine Lung, Using Laser Capture Microdissection

Pandemic influenza A(H1N1)pdm09 virus has retained its ability to infect swine whilst developing the ability to transmit effectively between humans, thus making the pig a valuable model for studying disease pathogenesis in both species. Lung lesions in pigs caused by infection with influenza A viruses vary in both their severity and distribution with individual lung lobes exhibiting lesions at different stages of infection pathogenic development and disease resolution. Consequently, investigating interactions between the virus and host and their implications for disease pathogenesis can be complicated. Studies were undertaken to investigate the discrete expression of pro- and anti-inflammatory mediators during lung lesion formation in pigs during infection with influenza A(H1N1)pdm09 (A/Hamburg/05/09) virus. Laser capture microdissection was used to identify and select lung lobules containing lesions at different stages of development. Dissected samples were analysed using quantitative RT-PCR to assess pro- and anti-inflammatory cytokine mRNA transcripts. Differential expression of the immune mediators IL-8, IL-10 and IFN-γ was observed depending upon the lesion stage assessed. Upregulation of IFN-γ, IL-8 and IL-10 mRNA was observed in stage 2 lesions, whereas decreased mRNA expression was observed in stage 3 lesions, with IL-8 actively downregulated when compared with controls in both stage 3 and stage 4 lesions. This study highlighted the value of using laser capture microdissection to isolate specific tissue regions and investigate subtle differences in cytokine mRNA expression during lesion development in pigs infected with influenza A(H1N1)pdm09.

Differential chemokine responses in the murine brain following lyssavirus infection

The hallmark of lyssavirus infection is lethal encephalomyelitis. Previous studies have reported distinct lyssavirus isolate-related differences in severity of cellular recruitment into the encephalon in a murine model of infection following peripheral inoculation with rabies virus (RABV) and European bat lyssavirus (EBLV)-1 and -2. In order to understand the role of chemokines in this process, comparative studies of the chemokine pattern, distribution and production in response to infection with these lyssaviruses were undertaken. Expression of CCL2, CCL5 and CXCL10 was observed throughout the murine brain with a distinct caudal bias in distribution, similar to both inflammatory changes and virus antigen distribution. CCL2 immunolabelling was localized to neuronal and astroglial populations. CCL5 immunolabelling was only detected in the astroglia, while CXCL10 labelling, although present in the astroglia, was more prominent in neurons. Isolate-dependent differences in the amount of chemokine immunolabelling in specific brain regions and chemokine production by neurons in vitro were observed, with a greater expression of CCL5 in vivo and CXCL10 production in vitro after EBLV infection. Additionally, strong positive associations between chemokine immunolabelling and perivascular cuffing and, to a lesser extent, virus antigen score were also observed. These differences in chemokine expression may explain the variation in severity of encephalitic changes observed in animals infected with different lyssavirus isolates.

Pathobiology of rabies virus and the European bat lyssaviruses in experimentally infected mice

A comparison of the clinicopathology of European bat lyssavirus (EBLV) types-1 and -2 and of rabies virus was undertaken. Following inoculation of mice at a peripheral site with these viruses, clinical signs of rabies and distribution of virus antigen in the mouse brain were examined. The appearance of clinical signs of disease varied both within and across the different virus species, with variation in incubation periods and weight loss throughout disease progression. The distribution of viral antigen throughout the regions of the brain examined was similar for each of the isolates during the different stages of disease progression, suggesting that antigen distribution was not associated with clinical presentation. However, specific regions of the brain including the cerebellum, caudal medulla, hypothalamus and thalamus, showed notable differences in the proportion of virus antigen positive cells present in comparison to other brain regions suggesting that these areas are important in disease development irrespective of virus species.

Disposable sensors for rapid screening of mutated genes

A screening method for rapid detection of gene mutations directly in polymerase chain reaction (PCR) of genomic DNA is described. The method involves the development of a disposable screen-printed gold electrode modified with a thiolated capture probe directly obtained from denaturated PCR genomic DNA, which recognizes (by hybridization) its fully complementary sequence (wild type), giving a signal, whereas no signal is obtained for single-mismatched target (mutant). The detection of the hybridization event is achieved by changes in the metal redox center electroactivity of the complex [Ru(NH(3))(5) L](2+), where L is [3-(2-phenanthren-9-yl-vinyl)-pyridine], at -0.200 V. This complex binds to double-stranded DNA in a very selective form. The method allows discrimination between the wild type and the mutant of gene MRP3 directly in large PCR amplicons extracted from blood cells, without the need to use either synthetic probes or labeled targets. The mutation involves the presence of a single-nucleotide polymorphism (SNP) at base 54 of a 145-base-pair sequence from exon 21 of gene MRP3. Since the presence of this SNP might lead to a variety of hereditary liver disorders, its identification in a rapid and easy form may provide novel therapeutic targets for the future. The screening method proposed has excellent signal reproducibility, with a relative standard deviation of 10%. In addition, with the method developed as little as 6.6 ng/muL PCR product can be detected.

Kounis syndrome secondary to amoxicillin use in an asthmatic patient

A sixty-four year old man with a past history of hypercholesterolemia, asthma, food allergy, epilepsy and myocardial infarction was admitted to the emergency department because of a generalized erythema, nausea, vomiting, and chest pain after taking an oral dose of amoxicillin. Electrocardiography showed ST segment elevation in anterior leads. After coronary angiography, type 2 variant of Kounis syndrome was diagnosed. We present the first case of oral amoxicillin induced Kounis syndrome in an asthmatic patient with severe anaphylactic shock. The present report also shows that atopic people expressing an amplified mast cell degranulation may have more serious hemodynamic decompensation during hypersensitivity reactions. Case selective mast cell surface membrane stabilization should be considered a potential therapeutic strategy for people with food induced allergy, for atopic patients and for patients who have already experienced a first Kounis syndrome.

Effect of low doses of atorvastatin on the urinary peptide profile of kidney transplant patients

Statins are prescribed to reduce posttransplant dyslipidemia, which is frequent among kidney graft recipients. Their efficacy to reduce cholesterol levels has been accompanied by pleiotropic effects. Proteomics is the study of the expressed complement of proteins in tissues or biological fluids. It includes the identification of changes in proteins that occur in various states, eg, after drug administration. Our study objectives were: (1) to analyze the effect of atorvastatin (10 mg/d) on lipid profile, renal function, proteinuria, and inflammation parameters, such as C-reactive protein (CRP), and (2) to use proteomics to ascertain whether this treatment modified the patients' urinary peptide profiles seeking to understand the molecular actions of the drug. Urinary peptide profiles, lipids, renal function parameters (creatinine clearance), proteinuria, and CRP were determined in 39 patients at baseline and at 12 weeks after atorvastatin treatment (10 mg/d). The peptide fraction of each sample acquired using magnetic beads was analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Our results showed that treatment with atorvastatin produced a significant reduction in lipid profile, but did not modify renal function (creatinine clearance), proteinuria, or CRP. The proteomic study showed that statin treatment did not produce significant changes in the urinary peptidome, although there was a tendency for some peptides to increase or decrease after the treatment.

[Peripheral vitreoretinal traction exploration by Staurenghi 230 lens and HRA-II]

PURPOSE

To report a new technique to explore peripheral vitreous-retinal tractions in patients with acute posterior vitreous detachment.

MATERIAL AND METHODS

A population of 65 patients with acute posterior vitreous detachment was studied by panfunduscopic SLO 230 lens and HRA-II to detect peripheral retinal tears and vitreous-retinal tractions.

RESULTS

In our study, using indirect ophthalmoscopic exploration, we identified eleven patients with at least one retinal tear. HRA-II combined with the Staurenghi SLO 230 lens was capable of detecting 100% of these lesions. In addition, by means of this technology, we identified dark retinal zones that corresponded to peripheral retinal traction in six patients. None of the 65 patients complained of pain or photophobia during the exploration with this contact lens. Retinal tears and peripheral vitreous-retinal traction were treated by argon laser photocoagulation to create a firm chorioretinal adhesion. In two patients we found new retinal tears in the follow-up, with these new lesions detected by indirect ophthalmoscopy and HRA-II with SLO 230 lens.

CONCLUSION

HRA-II with the panfunduscopic Staurenghi SLO 230 lens can complement the exploration of patients with acute posterior vitreous detachment and can help to detect tractional zones that could develop into retinal tears.

Prevalence of serum antibodies to bovine herpesvirus-1 and bovine viral diarrhea virus in beef cattle in Uruguay

Our objective was to determine the prevalence of serum antibodies to bovine herpesvirus-1 (BHV-1) and bovine viral diarrhea (BVD) virus in beef cattle in Uruguay. A random sample of 230 herds selected with probability proportional to population size based on the number of cattle was chosen from a list frame of all registered livestock farms as of June 1999. Sera from up to 10 heifers, cows and bulls (up to 30 sera total per herd) were collected on selected farms between March 2000 and March 2001 and evaluated by means of enzyme-linked immunosorbent assays (ELISAs). Overall, 6358 serum samples were evaluated. We also collected data on previous diagnosis of BHV-1 or BVD infections and on the use of vaccines against these agents. The estimated prevalence of exposure to BHV-1 and BVD at the herd level for the Uruguayan beef population was 99% and 100%, respectively. Approximately 37% of beef cattle in Uruguay have been exposed to BHV-1 and 69% to BVD virus. Only 3% of beef herds in Uruguay regularly (typically, annually) use vaccines against either of these agents.

An immunohistochemical study of the tonsils in pigs with acute African swine fever virus infection

An immunohistochemical study of the tonsils was carried out to gain further insight in the pathogenesis of acute African swine fever (ASF). Twenty-one pigs were inoculated by intramuscular route with a highly virulent isolate of ASF virus and painlessly killed at 1-7dpi. Viral antigen was highly distributed in the tonsil from 3 to 4dpi and an increase in the number of monocyte-macrophages was very evident at the same days post inoculation. This phenomenon was observed together with an increase of the expression of proinflammatory cytokines (Tumour necrosis factor alpha and Interleukin-1 alpha) and the apoptosis of lymphocytes studied by the terminal deoxynucleotidyltransferase-mediated dUTP nick end labelling (TUNEL) technique and haemorrhages. With these results, we can conclude that the tonsil is suffering similar lesions than those observed in other lymphoid organs in acute African swine fever, even when the route of inoculation is the intramuscular and not oral-nasal.

[Exploration of the anterior segment by optical coherence tomography-3]

PURPOSE

To show the utility of optical coherence tomography (OCT) for studying the anterior segment and to explain its potential advantages as compared to ultrasonic biomicroscopy (UBM).

MATERIALS AND METHODS

We have described the findings in 5 patients with different pathologies of the anterior segment, all of whom were studied with UBM and OCT-3 adjusted for the anterior segment. There were 2 cases of an acute attack of closed angle glaucoma, 1 case of rubeosis iridis, 1 case of penetrating ocular trauma and 1 case of a primary stromal iris cyst.

RESULTS

OCT was found to be as useful as UBM in detecting angle closure in patients affected by an acute attack of glaucoma. In addition, OCT was more comfortable for the patient and faster than UBM in obtaining images, with the exploration mean time using OCT being less than five minutes while that with UBM was over ten minutes. OCT has also been demonstrated to be a safe and valuable non-contact examination in other iris pathologies such as rubeosis iridis, for checking the permeability of iridotomies and even for studying iris masses such as primary stromal iris cysts. In these entities OCT may reach a higher resolution than ultrasonic biomicroscopy.

CONCLUSION

OCT-3, with an adjustable focus, can obtain images from the scleral angle, as well as from other ocular structures like the iris, thus assisting in the diagnosis of numerous pathologies.

Cytokine Expression in Paraffin Wax-embedded Tissues from Conventional Calves

The cross-reactivity of antibodies against human tumour necrosis factor (TNF)alpha, interleukin (IL)-1alpha, IL-1beta and porcine IL-6, and the distribution of immunolabelled cells were evaluated on paraffin wax-embedded tissues from five healthy calves. The tissues were fixed in 10% buffered formalin or Bouin's solution and processed for structural studies and immunohistochemical studies by the avidin-biotin-peroxidase technique. Bouin's solution proved to be the more suitable fixative and Tween 20 the most effective antigen unmasking technique for increasing detectable antigenicity. Constitutive expression of TNFalpha, IL-1alpha, IL-1beta and IL-6 by different cell populations, mainly macrophage-like cells, was detected. Lymphoid organs displayed a higher presence of immunolabelled cells than did lung, liver or kidney. TNFalpha and IL-1alpha appeared as the predominant cytokines, especially in the gut-associated lymphoid tissue of the ileum and in the regional mesenteric lymph nodes. The results will facilitate investigation of the role of these cytokine-producing cells in inflammatory disease processes in calves.

Solubilization and characterization of a cell wall-bound trehalase from ascospores of the fission yeast Schizosaccharomyces pombe

The genome of the fission yeast Schizosaccharomyces pombe lacks sequence homologs to ath1 genes coding for acid trehalases in other yeasts or filamentous fungi. However, acid trehalase activity is present at the spore stage in the life cycle of the fission yeast. The enzyme responsible for this activity behaves as a surface enzyme covalently linked to the spore cell walls in both wild-type and ntp1 mutant strains devoid of neutral trehalase. Lytic treatment of particulated cell wall fractions allowed the solubilization of the enzyme into an active form. We have characterized this soluble enzyme and found that its kinetic parameters, optimum pH and temperature, thermal denaturation and salt responses are closely similar to other conventional acid trehalases. Hence, this rather unusual enzyme can be recognized as acid trehalase by its biochemical properties although it does not share genetic homology with other known acid trehalases. The potential role of such acid trehalase in the mobilization of trehalose is discussed.

Laser microdissection and microarray analysis of the hippocampus of Ras-GRF1 knockout mice reveals gene expression changes affecting signal transduction pathways related to memory and learning

We used manual macrodissection or laser capture microdissection (LCM) to isolate tissue sections of the hippocampus area of Ras-GRF1 wild type and knockout mice brains, and analyzed their transcriptional patterns using commercial oligonucleotide microarrays. Comparison between the transcriptomes of macrodissected and microdissected samples showed that the LCM samples allowed detection of significantly higher numbers of differentially expressed genes, with higher statistical rates of significance. These results validate LCM as a reliable technique for in vivo genomic studies in the brain hippocampus, where contamination by surrounding areas (not expressing Ras-GRF1) increases background noise and impairs identification of differentially expressed genes. Comparison between wild type and knockout LCM hippocampus samples revealed that Ras-GRF1 elimination caused significant gene expression changes, mostly affecting signal transduction and related neural processes. The list of 36 most differentially expressed genes included loci concerned mainly with Ras/G protein signaling and cytoskeletal organization (i.e. 14-3-3gamma/zeta, Kcnj6, Clasp2) or related, cross-talking pathways (i.e. jag2, decorin, strap). Consistent with the phenotypes shown by Ras-GRF1 knockout mice, many of these differentially expressed genes play functional roles in processes such as sensory development and function (i.e. Sptlc1, antiquitin, jag2) and/or neurological development/neurodegeneration processes affecting memory and learning. Indeed, potential links to neurodegenerative diseases such as Alzheimer disease (AD) or Creutzfeldt-Jacobs disease (CJD), have been reported for a number of differentially expressed genes identified in this study (Ptma, Aebp2, Clasp2, Hebp1, 14-3-3gamma/zeta, Csnk1delta, etc.). These data, together with the previously described role of IRS and insulin (known Ras-GRF1 activators) in AD, warrant further investigation of a potential functional link of Ras-GRF1 to neurodegenerative processes.

[Multidetector row CT in assessment of coronary artery calcification on hemodialisis]

Vascular calcification is a strong predictor of cardiovascular and all-cause mortality. Coronary artery calcification is more frequent, more extensive and progresses more rapidly in CKD than in general population. They are also considered a marker of coronary heart disease, with high prevalence and functional significance. It suggests that detection and surveillance may be worthwhile in general clinical practice. New non-invasive image techniques, like Multi-detector row CT, a type of spiral scanner, assess density and volume of calcification at multiple sites and allow quantitative scoring of vascular calcification using calcium scores analogous to those from electron-beam CT. We have assessed and quantified coronary artery calcification with 16 multidetector row CT in 44 patients on hemodialysis and their relationship with several cardiovascular risk factors. Coronary artery calcification prevalence was of 84 % with mean calcium score of 1580 +/- 2010 ( r 0-9844) with calcium score > 400 in 66% of patients. It was usually multiple, affecting more than two vessels in more than 50%. In all but one patient, left anterior descending artery was involved with higher calcium score level at right coronary artery. Advanced age, male, diabetes, smoking, more morbidity, cerebrovascular disease previous, and calcium-binders phosphate and analogous vitamin D treatment would seem to be associated with coronary artery calcification. Coronary artery calcification is very frequent and extensive, usually multiple and associated to modifiable risk factors in hemodialysis patients. Multi-detector-row CT seems an effective, suitable, readily applicable method to assess and quantify coronary artery calcification.

Proprioception in the ACL-ruptured knee: the contribution of the medial collateral ligament and patellar ligament. An in vivo experimental study in the cat

In the absence of anterior cruciate ligament (ACL), secondary restraints such as menisci, ligaments, and tendons restrict anterior knee laxity. Strain detection at these sites could define the contribution of this alternative signalling system to knee proprioception after ACL injury. The hypothesis in this study questions if measurements of anterior tibial translation (ATT) from surface strain gauges on the insertions of the medial collateral ligament (MCL) and the patellar tendon (PT) are sufficiently sensitive and specific to differentiate normal, stable knees from acutely unstable knees due to ACL section. Twelve cats received miniaturized strain gauges on the surface of MCL and PT distal insertions. A purpose-made receiver transformed into measurements any voltage variation obtained during passive knee flexion-extension and anterior tibial translation manoeuvres. Variables under evaluation included first peak latency, normalized amplitude, and slope of voltage along time. Femorotibial displacements were video recorded, digitized, and used as the ATT reference. The proposed system detected significant changes in the slope of the voltage/time signal, with higher specificity and sensitivity during ATT after experimental ACL section. Changes were not significant during flexion or extension. It was found that a pattern of earlier and more intense strain in MCL and PT distal insertions was found during ATT in the ACL deficient knee. Enhanced pattern recognition learning from these structures could be a future target for proprioceptive training after ACL injury.

[Good virological response to pegylated interferon alfa monotherapy of chronic hepatitis C infection in hemodialysis patient]

Liver disease caused by hepatitis C virus infection is associated to significant morbidity and mortality among patient with end stage renal disease on maintenance hemodialysis (HD). Therapy in these patients consists of Interferon, preferably pegylated Interferon (pIFN), thus Ribavirin (RBV) is not recommended for patients with impaired renal function, outside its use in controlled trials. We report a case of 35 years young woman on HD treatment, renal transplantation candidate with chronic hepatitis C virus infection, HCV RNA positive (by PCR), genotype 3a, moderate viral load, light increase of aminotransferases. Pegylated Interferon alfa-2a (135 mcg/weekly/SC) was initiated. She achieved HVC RNA negative within 12 weeks, following with pINF as monotherapy to complete 24 weeks (6 months). Sustained virologic response persisted to 24 and 48 weeks. Most important side effects were light detriment of anemia, moderate neutropenia and thombocytopenia, transitory elevation of transaminases and "flu-like" syndrome. Adverse events were well tolerated with total compliance with pIFN dose, no requiring reduce or stop the treatment. These findings confirm that hemodialysis patients with chronic hepatitis C respond well to pegylated IFN monotherapy and a long-term sustained virologic response is achieved, appears to be better tolerated with less side effects, so combination therapy with pINF plus ribavirin is not necessary in all cases.

Neuropathologic study of experimental classical swine fever

The aim of this study was to report on the lesions occurring in the central nervous system (CNS) during experimental classical swine fever (CSF) to clarify the spatial and chronologic distribution of the lesions and virus antigen in the CNS. To learn more about the pathogenetic mechanisms of the lesions during CSF in the CNS and to investigate the role of the virus in these mechanisms, cellular infiltrates and infected cells have been characterized. Twenty-eight pigs were inoculated with the virulent CSF virus isolate Alfort 187 and slaughtered from 2 to 15 postinoculation days; 4 animals of similar background served as a control group. Immunohistochemistry, electron microscopy, and the transferase-mediated deoxyuridine triphosphate nick-end labeling method were used to detect viral antigens and apoptosis. The results showed the presence of nonpurulent meningoencephalitis, occasional microhemorrhages, and apoptosis of the lymphocytes forming the perivascular and interstitital infiltrate in swine with CSF. Macrophages appeared to display little involvement in CNS lesions. The infected cells observed at the early stage of disease were lymphocytes and microglial cells in the rostral portion of the telencephalon, with infection of these cells in other areas in the next stages. The relationship between these lesions and the presence of viral antigen varied according to the type of lesion: hemorrhages were not associated with the presence of antigen in endothelial cells, but infiltrate-cell apoptosis was temporally and spacially associated to viral infection. However, the link between viral infection and the presence of cell infiltrate was far from clear.

Endogenous Lipid Pneumonia in a Dog

Endogenous lipid pneumonia has previously been diagnosed in dogs only once. This report describes a case in a dog with a persistent cough, in which the histological diagnosis was based on the presence of numerous foamy macrophages that filled the alveoli and contained small sudanophilic vacuoles. The appearance of endogenous lipid pneumonia in this animal was accompanied by Dirofilaria immitis infection and chronic bronchitis.