Potential infectivity of blood from HBsAG asymptomatic carriers due to the presence of HBV-DNA and comparison with other markers of hbv infection

Serum samples from 356 HBsAg positive asymptomatic carriers, which were titrated by reverse passive hemagglutination, were analysed for the presence of HBV-DNA, HBsAg and IgM anti-HBc. The samples were divided in three classes, according to the titers of HBsAg and IgM anti-HBc and the distribution of HBV-DNA and HBsAg among these classes was studied. In the high titer class of HBsAg, 65% of samples have one or both markers against only 19% in the low titer class. From the total of 356 samples, 121 gave positive results for IgM anti-HBc (33.9%). From these, 38.9% of HBV-DNA and 47.9% of HBeAg were observed, whereas in samples with absence of IgM anti-HBc, 18.3% and 16.6% were respectively found. A higher frequency of agreement between all these markers was found in the class of high titers of HBsAg; however, HBV-DNA was detected in the low titer class of HBsAg and little or no IgM anti-HBc, showing potential blood infectivity even in HBsAg positive borderline samples.

Simultaneous identification of Trypanosoma cruzi surface and internal antigens reactive to different immunoglobulin classes (radio-immunoblotting)

A radioactive Western-blotting technique was developed by which the reactivity of Immunoglobulins (Igs) from different classes to both membrane radiolabelled and internal parasite antigens is simultaneously identified. The method includes radioiodination of parasites, polypeptide fractionation by SDS-PAGE, Western-blot transfer and autoradiography of the immunoblots developed with anti-Igs conjugates labelled with enzymes. The analysis is then performed by the comparison of common bands on the autoradiograms and the respective substrate stained nitrocellulose blots. This technique was used to analyse T. cruzi trypomastigote surface labelled antigens reactive to IgM, IgA and IgG specific antibodies. A different pattern of reactivity with acute Chagas' disease patients sera was thus obtained.

Perspectives of the Internal Public in a Cultural Event: the Case of Noc Noc, Guimarães - Portugal

Given the significant impact that cultural events may have in local communities and the inherent organization complexity, it is important to understand their specificities. Most of the times cultural events disregard marketing and often marketing is distant from art. Thus an analysis of an inside perspective might bring significant returns to the organization of such an event. This paper considers the three editions (2011, 2012 and 2013) of a cultural event – Noc Noc – organized by a local association in the city of Guimarães, Portugal. Its format is based in analogous events, as Noc Noc intends to convert everyday spaces (homes, commercial outlets and a number of other buildings) into cultural spaces, processed and transformed by artists, hosts and audiences. By interviewing a sample of people (20) who have hosted this cultural event, sometimes doubling as artists, and by experiencing the three editions of the event, this paper illustrates how the internal public understands this particular cultural event, analyzing specifically their motivations, ways of acting and participating, as well as their relationship with the public, with the organization of the event and with art in general. Results support that artists and hosts motivations must be identified in a timely and appropriate moment, as well as their views of this particular cultural event, in order to keep them participating, since low budget cultural events such as this one may have a key role in small scale cities.

Foraging at the Edge of Chaos: Internal Clock versus External Forcing

Activity rhythms in animal groups arise both from external changes in the environment, as well as from internal group dynamics. These cycles are reminiscent of physical and chemical systems with quasiperiodic and even chaotic behavior resulting from “autocatalytic” mechanisms. We use nonlinear differential equations to model how the coupling between the self-excitatory interactions of individuals and external forcing can produce four different types of activity rhythms: quasiperiodic, chaotic, phase locked, and displaying over or under shooting. At the transition between quasiperiodic and chaotic regimes, activity cycles are asymmetrical, with rapid activity increases and slower decreases and a phase shift between external forcing and activity. We find similar activity patterns in ant colonies in response to varying temperature during the day. Thus foraging ants operate in a region of quasiperiodicity close to a cascade of transitions leading to chaos. The model suggests that a wide range of temporal structures and irregularities seen in the activity of animal and human groups might be accounted for by the coupling between collectively generated internal clocks and external forcings.

P53 and Cancer-Associated Sialylated Glycans Are Surrogate Markers of Cancerization of the Bladder Associated with Schistosoma haematobium Infection

BACKGROUND: Bladder cancer is a significant health problem in rural areas of Africa and the Middle East where Schistosoma haematobium is prevalent, supporting an association between malignant transformation and infection by this blood fluke. Nevertheless, the molecular mechanisms linking these events are poorly understood. Bladder cancers in infected populations are generally diagnosed at a late stage since there is a lack of non-invasive diagnostic tools, hence enforcing the need for early carcinogenesis markers. METHODOLOGY/PRINCIPAL FINDINGS: Forty-three formalin-fixed paraffin-embedded bladder biopsies of S. haematobium-infected patients, consisting of bladder tumours, tumour adjacent mucosa and pre-malignant/malignant urothelial lesions, were screened for bladder cancer biomarkers. These included the oncoprotein p53, the tumour proliferation rate (Ki-67>17%), cell-surface cancer-associated glycan sialyl-Tn (sTn) and sialyl-Lewisa/x (sLea/sLex), involved in immune escape and metastasis. Bladder tumours of non-S. haematobium etiology and normal urothelium were used as controls. S. haematobium-associated benign/pre-malignant lesions present alterations in p53 and sLex that were also found in bladder tumors. Similar results were observed in non-S. haematobium associated tumours, irrespectively of their histological nature, denoting some common molecular pathways. In addition, most benign/pre-malignant lesions also expressed sLea. However, proliferative phenotypes were more prevalent in lesions adjacent to bladder tumors while sLea was characteristic of sole benign/pre-malignant lesions, suggesting it may be a biomarker of early carcionogenesis associated with the parasite. A correlation was observed between the frequency of the biomarkers in the tumor and adjacent mucosa, with the exception of Ki-67. Most S. haematobium eggs embedded in the urothelium were also positive for sLea and sLex. Reinforcing the pathologic nature of the studied biomarkers, none was observed in the healthy urothelium. CONCLUSION/SIGNIFICANCE: This preliminary study suggests that p53 and sialylated glycans are surrogate biomarkers of bladder cancerization associated with S. haematobium, highlighting a missing link between infection and cancer development. Eggs of S. haematobium express sLea and sLex antigens in mimicry of human leukocytes glycosylation, which may play a role in the colonization and disease dissemination. These observations may help the early identification of infected patients at a higher risk of developing bladder cancer and guide the future development of non-invasive diagnostic tests.

Evaluation of phenotypic markers associated with pathogenicity in the genus Listeria

A total of 130 Listeria strains were tested in order to evaluate lecithinase production and capacity for Congo red adsorption as markers of pathogenicity. The strains were identified according to acid production from sugars and by the CAMP test and the data were correlated with the ability to produce keratoconjunctivitis in guinea pigs. L. monocytogenes cultures presented 51.8% and 88.8% positivity rates for Congo red adsorption and lecithinase production, respectively, whereas 80.8% and 100% for L. innocua cultures were negative for the two test, respectively

Virtual Power Players Internal Negotiation and Management in MASCEM

Electricity Markets are not only a new reality but an evolving one as the involved players and rules change at a relatively high rate. Multi-agent simulation combined with Artificial Intelligence techniques may result in very helpful sophisticated tools. This paper presents a new methodology for the management of coalitions in electricity markets. This approach is tested using the multi-agent market simulator MASCEM (Multi-Agent Simulator of Competitive Electricity Markets), taking advantage of its ability to provide the means to model and simulate Virtual Power Players (VPP). VPPs are represented as coalitions of agents, with the capability of negotiating both in the market and internally, with their members in order to combine and manage their individual specific characteristics and goals, with the strategy and objectives of the VPP itself. A case study using real data from the Iberian Electricity Market is performed to validate and illustrate the proposed approach.

PREVALENCE OF HEPATITIS B AND HEPATITIS C MARKERS IN ALCOHOLICS WITH AND WITHOUT CLINICALLY EVIDENT HEPATIC CIRRHOSIS

We assessed the frequency of serological markers of hepatitis B virus (HBV) and hepatitis C virus (HCV) infections in 365 alcoholics by determining, by ELISA, the presence of HBsAg, anti-HBc, anti-HBs and anti-HCV. Fifty patients were cirrhotics and 315 had no evidence of hepatic cirrhosis; of the latter HBsAg was assessed in all, anti-HBc and anti-HBs in 130, and anti-HCV in 210. Among the alcoholics the frequencies of HBsAg (1.9%), anti-HBc (28.3%) and anti-HCV (3.8%) were higher (p<0.001) than among the controls (N=17,059), 0.4%, 4.0% and 0.4% respectively. The frequency of positive HBsAg was higher (p<0.001) in the cirrhotic patients (8.0%) than in alcoholics without cirrhosis (0.95%) and in controls (0.4%), and similar between the latter; of anti-HBc in alcoholics without cirrhosis (28.5%) was similar in cirrhotics patients (28.0%) and higher (p<0.001) than in the controls (4.0%); of anti-HBs in alcoholics without cirrhosis (20.8%) was similar to that of the cirrhotic patients (10.0%), and the anti-HCV was similar between alcoholics with (6.0%) and without cirrhosis (3.3%) and higher (p<0.001) than in controls (0.4%). We concluded that: a) alcoholics with or without cirrhosis have similar frequencies of infection with HBV and HCV between them, and higher than in nonalcoholics; b) alcoholics without cirrhosis had a frequency of HBV active infection (HBsAg+) which was similar to the controls, whereas among those who progressed to cirrhosis this frequency was significantly higher, what suggests that HBV may be implicated in the pathogenesis of cirrhosis in a few alcoholic individuals.

Diagnosis of plague and identification of virulence markers in Yersinia pestis by multiplex-PCR

We have developed a procedure for the rapid diagnosis of plague that also allows the identification of prominent virulence markers of Y. pestis strains. This procedure is based upon the use of a single polymerase chain reaction with multiple pairs of primers directed at genes present in the three virulence plasmids as well as in the chromosomal pathogenicity island of the bacterium. The technique allowed the discrimination of strains which lacked one or more of the known pathogenic loci, using as template total DNA obtained from bacterial cultures and from simulated blood cultures containing diluted concentration of bacteria. It also proved effective in confirming the disease in a blood culture from a plague suspected patient. As the results are obtained in a few hours this technique will be useful in the methodology of the Plague Control Program.

Hepatitis B and C virus markers among patients with hepatosplenic mansonic schistosomiasis

PURPOSE: To evaluate the frequency and the consequences of the co-infection of hepatitis B and C viruses in patients with hepatosplenic schistosomiasis (HSS). METHODS: B and C serologic markers, exposure to risk factors, biochemical assays, upper gastrointestinal endoscopies, and abdominal ultrasonograms were evaluated in 101 patients with HSS from 1994 to 1997. Whenever possible, PCR was tested and histopathological studies were reviewed. RESULTS: At least one HBV virus marker was found in 15.8%, and anti-HCV was detected in 12.9% of the subjects. The seropositive subjects tended to be older than the seronegative ones. A history of blood transfusion was significantly related to the presence of anti-HCV. Three (18.75%) out of 16 subjects exposed to B virus were HBsAg positive. Eleven (84.6%) out of thirteen patients who were anti-HCV positive demonstrated viral activity. Patients with ongoing viral infection presented a higher average level of liver aminotransferases, a higher frequency of cell decompensation and a higher rate of chronic hepatitis. Portal hypertension parameters were not influenced by viral exposure. CONCLUSIONS: The rate of hepatitis B and C viruses serologic markers observed in the patients with HSS was higher than the control group. The co-infection was responsible for a higher frequency of cell decompensation.

Evaluation of surrogate markers for human immunodeficiency virus infection among blood donors at the blood bank of "Hospital Universitário Regional Norte do Paraná", Londrina, PR, Brazil

This study evaluated the usefulness of the anti-HBc, hepatitis C virus antibodies (anti-HCV), human T cell lymphotropic virus I and II antibodies (anti-HTLV I/II), serologic tests for syphilis, and surface antigen of hepatitis B virus (HBsAg) as surrogate markers for the risk for HIV infection in 80,284 serum samples from blood donors from the Blood Bank of "Hospital Universitário Regional Norte do Paraná", Londrina, Paraná State, Brazil, analyzed from July 1994 to April 2001. Among 39 blood donors with positive serology for HIV, 12 (30.8%) were anti-HBc positive, 10 (25.6%) for anti-HCV, 1 (2.6%) for anti-HTLV I/I, 1 (2.6%) was positive for syphilis, and 1 (2.6%) for HBsAg. Among the donors with negative serology for HIV, these markers were detected in 8,407 (10.5%), 441 (0.5%), 189 (0.2%), 464 (0.6%), and 473 (0.6%) samples, respectively. The difference was statistically significant (p < 0.001) for anti-HBc and anti-HCV. Although the predictive positive value for these surrogate markers were low for HIV infection, the results confirmed the anti-HBc and anti-HCV as useful surrogate markers for HIV infection thus reinforcing the maintenance of them in the screening for blood donors contributing to the prevention of the small number of cases in which HIV is still transmitted by transfusion.

The biological meaning of anti-HBC positive result in blood donors: relation to HBV-DNA and to other serological markers

In order to assess the potential risk of anti-HBc-positive blood donors for post-transfusional hepatitis and to investigate whether other HBV serological markers are capable of identifying the presence of the virus, 1000 first-time blood donors were enrolled between June and July 1997. These donors were screened using routine Brazilian blood center tests (HIV 1 and 2, HTLV 1 and 2, Chagas disease, Syphilis, HCV, HBsAg, anti-HBc and ALT ). The 120 (12%) found to be anti-HBc-positive underwent further tests: HBe, anti-HBe, anti-HBs and HBV-DNA by PCR. Ten cases were HBsAg positive and all were HBV-DNA positive by PCR. Three HBsAg-negative donors were HBV-DNA-positive. Two HBV-DNA-positive donors were also anti-HBs-positive. All the HBV-positive donors had at least one HBV marker other than anti-HBc. Anti-HBc is an important cause of blood rejection. Testing for HBsAg alone is not fully protective and anti-HBc remains necessary as a screening test. The presence of anti-HBs is not always indicative of absence of the virus. The addition of other HBV serological markers could represent an alternative in predicting the presence of the virus when compared with PCR. It is recommended that other studies should be carried out to confirm this finding.