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Although at the global level the incidence of HIV has declined there are contrary trends gaining momentum. Unimpressed by public prevention campaigns certain groups belonging to the 'at-risk' population are engaging in risky sexual behaviour and concomitant misuse of illicit drugs thereby potentiating the odds of spreading HIV and other sexually transmitted infections (STIs). The blending of drug misuse with substantial risky sexual behaviour increases those risks and creates an almost inseparable complexity. Group-sex settings of this kind are partly organised via national and international social networks. Those people engaged in this modern trend mostly present with various health impairments thereafter, such as unconsciousness or confusion, often rendering them unable to adhere to combined antiretroviral therapy (cART) if they are HIV-infected. These people staunchly refuse to cooperate with prevention messages. Thereby public prevention efforts to curb the spread of HIV are largely wasted. But it is not just the individual's issue; if developments of this kind are not contained serious challenges with HIV and other STIs might arise for these communities. [ABSTRACT FROM AUTHOR]

Objective: To reconstruct the nucleotide sequence of Leptospira interrogans lipL21 gene for increasing the output of prokaryotic expression and to understand the changes on immunogenicity of the expression products before and after reconstruction, and to determine the position of envelope lipoprotein LipL21 on the surface of leptospiral body., Methods: According to the preferred codons of E.coli, the nucleotide sequence of lipL21 gene was designed and synthesized, and then its prokaryotic expression system was constructed. By using SDS-PAGE plus BioRad agarose image analysor, the expression level changes of lipL21 genes before and after reconstruction were measured. A Western blot assay using rabbit anti-TR/Patoc I serum as the first antibody was performed to identify the immunoreactivity of the two target recombinant proteins rLipL21s before and after reconstruction. The changes of cross agglutination titers of antisera against two rLipL21s before and after reconstruction to the different leptospiral serogroups were demonstrated using microscope agglutination test (MAT). Immuno-electronmicroscopy was applied to confirm the location of LipL21s., Result: The expression outputs of original and reconstructed lipL21 genes were 8.5 % and 46.5 % of the total bacterial proteins, respectively. Both the two rLipL21s could take place immune conjugation reaction with TR/Patoc I antiserum. After immunization with each of the two rLipL21s in rabbits, the animals could produce specific antibody. Similar MAT titers with 1:80 - 1:320 of the two antisera against rLipL21s were present. LipL21 was confirmed to locate on the surface of leptospiral envelope., Conclusion: LipL21 is a superficial antigen of Leptospira interrogans. The expression output of the reconstructed lipL21 gene is remarkably increased. The expression rLipL21 maintains fine antigenicity and immunoreactivity and its antibody still shows an extensive cross immunoagglutination activity. The high expression of the reconstructed lipL21 gene will offer a favorable condition to use its product for further developing a novel universal vaccine as well as detection kit of leptospirosis.

Despite the introduction of campaigns to prevent the continued spread of HIV/AIDS in Germany, the number of annual firsttime HIV-diagnoses is continuing steadily. The concepts behind the current campaigns are largely based on models of New Public Health, of which social learning strategies are an essential element. The established personal and individual rights should be unimpeachable but the right not to know the status of HIV infection should be questioned for those people who spread their HIV infection intentionally and wilfully. Confronted with more than 10,000 people in Germany unconscious of their HIV infection, easy access to HIV testing and access of opportune therapy should be offered with the goal of reducing the number of new infections. Expanded strategies on the responsibility to one's personal health and that of the partner, understandable and adapted to special groups of the society, should be established and maintained at a high level of awareness. All measures must be performed voluntarily.

Aim: To determine whether the nucleotide sequences homologous to GBV-C genome exist in the DNA from cell lines of human origin and from peripheral blood mononuclear cells (PBMC) of human and chimpanzee., Methods: DNA of MT2 cell, HeLa cell, and PBMC from six human and one chimpanzee were prepared by using PCR Temperate Preparation Kit. All of the DNA preparations were digested with DNase-free RN ase and then were extracted by phenol-chloroform method. By using these DNA as templates, direct nested-PCR (dPCR) respectively amplified with GBV-C 5'-NCR and NS3 primers were carried out. Nucleotide sequences of the dPCR products were analyzed and positions in chromosomes of the amplification fragments were detected by using primed in situ (PRINS) sequence-specific labeling with fluorescein., Results: DNA fragments amplified with GBV-C 5'-NCR primers were obtained from the DNA of MT2 and HeLa cells and the DNA in 4 of 6 human PBMC samples. DNA fragments amplified with GBV-C NS3 primers were obtained from MT2 and HeLa cells and the DNA in 5 of 6 human PBMC samples and one chimpanzee PBMC sample. The homology of the nucleotide sequences from these amplification products compared with the reported GBV-C genome sequence was from 73.80 % to 79.15 %. Fluorescence staining spots by using PRINS were shown in the PBMC and their chromosomes with positive dPCR results., Conclusion: The nucleotide sequences with high homology to GBV-C genome at the 5'-NCR and/or NS3 region exist in the DNA of MT2 and HeLa cells and the PBMC DNA of human and chimpanzee. These sequences locate in the chromosomes of PBMC with positive dPCR results.

This study aimed to look for further HCV-specific sequences at the DNA level of healthy, HCV-negative individuals. Here, the sequence section from nt 57 to nt 328 within the 5'-NCR was assayed. Different combinations of primers were used in the nested PCR without a preceding reverse transcriptase step, resulting in fragments of the expected molecular weight size and also shorter and longer ones. It shows that the major part of the 5'-non-coding region (5'-NCR) of the hepatitis C virus genome is present in the DNA fraction from peripheral blood mononuclear cells (PBMCs) of healthy, anti-HCV-negative individuals tested. Furthermore we designed experiments to prove the specificity of these findings, by using restriction enzymes for digest assays of the target DNA before PCR (pre-PCR digest) and of the products after PCR (post-PCR digest). In conclusion, our study indicates that the main part of the internal ribosome entry site (IRES) structure of HCV at least is contained in the DNA of the individuals tested.

A series of 118 serum samples tested positive in the anti-hepatitis C virus (HCV) 2nd-generation enzyme immunoassay (EIA-2), and indeterminate (93 samples) or negative (25 samples) in the supplementary 2nd-generation recombinant immunoblot assay (RIBA-2). These sera were further evaluated by three additional tests: 3rd-generation RIBA (RIBA-3), MATRIX, and AMPLICOR HCV-PCR. For the 93 RIBA-2 indeterminate serum samples, the results of the immunoassays had a concordance of 69%. Twenty-one and 34 samples remained anti-HCV indeterminate in the RIBA-3 test and the MATRIX, respectively. Among the 25 RIBA-2-negative samples, only seven samples remained anti-HCV negative, while five samples tested anti-HCV positive in both RIBA-3 and MATRIX. The reactivity of the RIBA-3 antigen NS5 was not crucial for the result of any sample. Positive to negative contradictions between the results of MATRIX and RIBA-3 were never observed. Altogether, the MATRIX tested a significantly lower number of samples anti-HCV negative than did the RIBA-3. HCV RNA was detectable in 54/93 RIBA-2 indeterminate and 7/25 RIBA-2 negative samples. High percentages of PCR positive results among RIBA-3-indeterminate and among MATRIX-indeterminate samples indicate an increased possibility of detecting HCV RNA if at least one antigen is reactive. The type of antigen, the pattern of antigen reactivity, or the level of reactivity had no prognostic value in predicting the presence of HCV RNA. Our findings show the necessity of being cautious in the interpretation of RIBA-2-negative results.

The sequence 'GOR47-1' is a consistent part of human DNA; the expressed polypeptide of it 'GOR' is accepted to be an autoantigen, and the anti-GOR an autoantibody. However, GOR47-1 was originally isolated through a cDNA clone from blood of a chimpanzee. This animal belonged to a series of chimpanzees, in which human plasma of a patient with non-A, non-B hepatitis had been passaged. To date, nothing is known how it is that this 'sequence GOR47-1' without recognizable self-replicating properties and allocated to the human genome could be isolated from a chimpanzee plasma. The aim of this study was to detect by polymerase chain reaction GOR47-1 sequences in healthy, anti-HCV-negative humans, HCV-positive patients, chimpanzee, snake, and in maize and tobacco plants. The GOR47-1 sequence is present not only in human DNA but also with a high degree of homology in chimpanzee DNA. Essential parts of this sequence are also present in DNA of a snake and the two plants listed above. Our findings reveal that the GOR47-1 sequence isolated from a chimpanzee was probably of the chimpanzee origin. This fact has not yet been considered up until now, when discussing the role of GOR/anti-GOR in humans particularly suffering from chronic hepatitis C.

No convincing support has been provided so far for the existence of extrahepatic hepatitis C virus particles that should correspond to the sometimes extremely high concentration of 'HCV-RNA' in serum or plasma. If a naturally occurring HCV-specific DNA were to be found, a concept for at least some phenomena in terms of the pathophysiology of HCV should become conceivable. DNA was extracted from peripheral blood mononuclear cells of eleven healthy, anti-HCV-negative individuals, including five long term blood donors, and cells from different cell lines. DNA was subjected to nested polymerase chain reaction omitting a reverse transcriptase step with primers of the 5'NC as well as part of the core region of HCV. Direct polymerase chain reaction, i.e. without a reverse transcriptase step, revealed HCV-specific sequences in the DNA fraction of peripheral blood mononuclear cells of different origin: healthy anti-HCV negative individuals, furthermore in HeLa and MT2 cells. The fragments found were of expected length as well as of shorter and of longer than expected length with respect to the sequence of the HCV genome framed by the primers applied. The results derived from additional hybridization, restriction endonuclase analysis, and sequencing demonstrated HCV-specific sequences in the expected fragments with both a high degree of homology and deletions, respectively, substitutions, as compared to a prototype strain. However, the longer than expected fragments also contained sequences not specific for HCV.

Several lines of evidence suggest a dysregulation of the complement system in human immunodeficiency virus-1 (HIV-1) infected patients. The aim of this study was to elucidate whether CD4+ alveolar lymphocytes from HIV-1 infected patients show a loss of complement regulatory proteins that would render these cells susceptible to antibody-dependent complement-mediated cytotoxicity. We investigated the expression of complement regulatory (CD46, CD55, CD59) and complement receptor (CR1, CR2, CR3, CR4) proteins on alveolar cells by flow cytometry. Cells were obtained by bronchoalveolar lavage from 17 HIV-1 infected and 12 HIV-1 negative individuals. Expression of adhesion molecules (leucocyte functional associated antigen-1 (LFA-1), intercellular adhesion molecule-1 (ICAM-1)) and CD30 were evaluated in patient subgroups. In addition, interleukin (IL)-1beta, tumour necrosis factor alpha (TNF-alpha), IL-4 and interferon gamma (IFN-gamma) concentrations were measured in supernatants of alveolar cells. We found a significantly reduced expression of CD46 and CD59 on CD4+ alveolar lymphocytes from HIV-1 infected individuals, whereas the expression of CR3, CR4, ICAM-1 and CD30 was increased. IL-1beta and TNF-alpha concentration in supernatants of alveolar cells was augmented in HIV-1 infected patients, but did not correlate with the expression of surface molecules. IFN-gamma concentration was also increased and showed an inverse relationship to the surface expression of CD30 on CD4+. Our data suggest that in human immunodeficiency virus-1 infection an increased level of activation is associated with a diminished expression of complement regulatory proteins on CD4+ alveolar lymphocytes. This phenomenon might contribute to the depletion of CD4+ lymphocytes and the local immunodeficiency in the pulmonary compartment.

There have been repeated discussions as to whether the implementation of anti-HBc screening of blood donations in Germany would be useful. We present several cases of HBsAg-negative patients and blood donors in whose plasma HBV-DNA was mainly found only after enrichment of virus particles by ultracentrifugation. In the case of a seroconverting blood donor, 3 of 4 HBsAg tests could not detect HBsAg. 90% of our HBsAg-negative, but HBV-DNA containing samples (n = 10) were positive for anti-HBc. The 'nested' PCR without previous ultracentrifugation was positive in only under 30% of the samples. Ultracentrifugation is an expensive method and will not be practicable for the testing of all blood donations. We conclude that the HBsAg tests which are available should be subjected to improvement. In addition, the implementation of anti-HBc screening could decrease the risk of posttransfusion HBV infection more effectively than PCR testing from nonenriched serum.