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Biomedical subjects

L Gürtler

Publications and source records attributed to L Gürtler.

At least 91 records · Page 5Linked to original sources
PubMed1994

[Possibilities of virus inactivation of pooled fresh plasma with tri-n-butylphosphate (TNBP) detergents (SD procedure)].

Treatment with tri-n-butyl-phosphate and detergent (SD-treatment) leads to efficient inactivation of viruses having a lipid enveloped surface, like hepatitis B virus, hepatitis C virus and human immunodeficiency virus, that are presently the most transfusion relevant viruses in Germany. Other lipid enveloped viruses of the herpes group like cytomegalovirus and Epstein-Barr virus are inactivated as well. Non-enveloped viruses like parvovirus B19 and picornaviruses are not inactivated by SD-treatment. Future inactivation of blood components like plasma and blood products will be a combination of SD- and heat-treatment. Keeping single plasma units in quarantine for 6 months is one of the alternatives in elevating transfusion safety. For transfused blood the safety against infectious agent will continue to depend on the effectiveness of donor selection and the efficacy of testing.

Acquired Immunodeficiency Syndrome↗
PubMed1993

A critical analysis of human immunodeficiency virus transmission using human cartilage allografts.

Allogeneic cartilage represents an important source of tissue for reconstructive surgery in the head and neck. The use of allografts is now being discussed because of the possible transmission of the human immunodeficiency virus (HIV). The receptor for HIV in most cell types is the CD-4 molecule. Since cartilage is a popular homograft source, the purpose of this study was to investigate the presence of CD-4 molecules on cartilage tissue as detected with an immunoperoxidase staining and immunofluorescence flow cytometric analysis using a monoclonal antibody. Our results indicate clearly the absence of the HIV receptor on human cartilage tissue. We have concluded therefore that normal cartilage tissue cannot be infected by HIV, at least not through a CD-4-dependent mechanism.

CD4 Antigens↗
PubMed1993

[In vitro studies of possible transmission of human immunodeficiency virus (HIV) by allogeneic cartilage transplants].

With the increasing prevalence of the human immunodeficiency virus (HIV), the possibility of a transmission of HIV via allogenic transplants has increased. To assess the risk of transferring HIV with allogenic cartilage grafts we investigated the susceptibility of chondrocytes to the virus. Our results indicate the absence of the HIV receptor (CD-4-molecule) on chondrocytes by immunohistochemistry and FACS analyses. Furthermore cultures from chondrocytes and high doses of HIV-1 did not show an active replication. Hence, we conclude that normal cartilage cells cannot be infected by HIV. This means that the risk of HIV transmission by cartilage allografts is very low if no contaminating tissues like blood, perichondrium and calcifications etc. are present.

CD4 Antigens↗
PubMed1993

HIV-1 and HIV-2 isolates differ in their ability to activate the complement system on the surface of infected cells.

OBJECTIVE: To analyse the ability of different HIV-1 and HIV-2 isolates to activate the complement system. DESIGN: H9 cells chronically infected with various HIV isolates and the corresponding purified viruses were tested for complement activation. To identify the molecules responsible for complement activation on the surface of infected cells, the expression of complement inhibitors/regulators and viral proteins on the cell surface was analysed. METHODS: C3 deposition on the cell surface and the expression of viral and cellular antigens were determined by flow cytometry analysis. Complement activation by purified viruses was measured using a complement consumption assay and a C1 activation assay. RESULTS: H9 cells infected with different HIV-1 and HIV-2 isolates showed varying degrees of complement activation on the cell surface, ranging from strong activation and deposition of large amounts of C3 to no increased C3 deposition compared to uninfected cells. The C3 deposition was eliminated by EDTA and reduced in the presence of EGTA. In contrast, all purified viral isolates tested activated the complement system in a comparable manner. While the expression of MCP, DAF and CD59 was not modified after infection with different viral isolates, the reaction of the infected cells with a monoclonal antibody (3D6) directed against a gp41 epitope (amino acids 601-620) was found to correlate with the complement activation on the cell surface. CONCLUSIONS: Some HIV-1 as well as HIV-2 isolates activate the complement system on the surface of infected cells independent of anti-HIV antibodies, while other isolates fail to do so. Complement activation on the cell surface is mediated by the alternative and, to a lesser extent, the classical pathway. The differences in complement activation on the cell surface are not caused by a modified expression of membrane-bound complement inhibitors/regulators. C3 deposition on the cell surface correlates with the expression of an epitope lying within the major complement activating domain of gp41 (amino acids 591-620). These results suggest a role of gp41 for complement activation on HIV-infected cells as has been described previously for purified HIV.

Antigens, CD↗
PubMed1992

The monoclonal CD4 antibody M-T413 inhibits cellular infection with human immunodeficiency virus after viral attachment to the cell membrane: an approach to postexposure prophylaxis.

Infectious cellular uptake of human immunodeficiency virus (HIV) is initiated by a complex sequence of interactions between the viral envelope gp120/gp41 complex and the cellular CD4 receptor resulting in the exposure of a hydrophobic region of gp41 that mediates the irreversible fusion of the virus with the cell membrane. Here we show that viral penetration into a susceptible cell can be inhibited by the high-affinity monoclonal CD4 antibody (CD4 mAb) M-T413 even when it is added as late as 30-120 min after the initial contact of virus with the cell membrane. Inhibition of infection was assessed by monitoring cultures for 34 days after exposure to virus using four different methods simultaneously, including detection of viral DNA by PCR. The interval during which HIV remains sensitive to postbinding neutralization by CD4 mAb depends on strain of virus and type of target cell. Preparations of recombinant soluble CD4 (and the immunoadhesin CD4-IgG1) were much less efficient when compared with mAb M-T413, particularly in blocking infection by fresh HIV-1 isolates. Also cellular transmission of HIV, as determined by syncytia formation within 24 hr, was prevented by mAb M-T413 when added within 45 min of contact of infected H9 cells with uninfected C8166 cells. Together with the favorable clinical experience obtained with CD4 mAbs as immunomodulatory drugs, these data suggest that infusion of CD4 mAb M-T413 may be a therapeutic modus for immediate prophylactic intervention after occupational exposure to HIV and for prevention of intrapartum mother-to-infant HIV transmission.

Animals↗
PubMed1992

Inter-alpha-trypsin inhibitor polymorphism in African blacks.

The inter-alpha-trypsin inhibitor (ITI) polymorphism was analyzed in an African Negroid population using polyacrylamide gel isoelectric focusing and subsequent immunoblotting. Gene frequencies of ITI*1, ITI*2, ITI*3 and ITI*4 were calculated to be 0.564, 0.083, 0.337 and 0.004, respectively. One unknown rare allele, ITI*6, determines further phenotypes in combination with the alleles ITI*1 and ITI*3. Gene frequency of ITI*6 was calculated to be 0.012. The common alleles are represented by ITI*1 and ITI*3. The allele distribution is therefore different from European and Asian populations.

Alpha-Globulins↗
PubMed1992

[Differences in detectability of human immunodeficiency virus type 1 in tears and blood lymphocytes].

Reported data on the isolation of the human immunodeficiency virus type 1 (HIV-1) from tears are controversial. The purpose of the study was to try to isolate HIV-1 from tears in a large sample of HIV-1-positive patients at different stages of infection. 53 tear samples were obtained from 50 patients. Additionally isolation of HIV-1 from peripheral blood lymphocytes (PBL) was attempted. HIV-1 was isolated from none (= 0%) of the 53 tear samples. Isolation from PBL was successful depending on absolute CD4+ lymphocyte count and Walter Reed staging (Walter Reed stage 6: 83%; stage 2 to 5: 11%; p less than 0.0001). Treatment with zidovudine was not related to the frequency of HIV-1 isolation. These results suggest that tears of patients infected with HIV-1 contain low or no quantities of tissue-culture-infectious units of HIV-1. Nosocomial infection with HIV-1 from tears appears to be unlikely. The known precautions for the prevention of spread of viral disease in ophthalmological practice are sufficient and should be strictly followed.

Adolescent↗