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The safety and pharmacokinetics of the two neutralizing human IgG1 monoclonal antibodies to cytomegalovirus (CMV) SDZ 89-104 and 89-109 in bone marrow transplant (BMT) recipients was assessed in an open phase I trial. Thirteen patients, 8 seropositive and 5 seronegative for CMV, were treated with allogeneic or autologous bone marrow transplantation. SDZ 89-104 was given to 5 and SDZ 89-109 to 8 patients. Patients were divided into high- and low-dose groups. A fixed prestudy dose of 0.1 mg/kg was given 4 days before BMT. On days 3, 17, 31, 45, 59, and 73, patients were treated with either 0.5 or 2 mg/kg of the respective antibody. Results indicate that doses of 2 mg/kg of SDZ 89-104 or SDZ 89-109 in alternating weeks can be safely administered to BMT patients. Serum trough levels measured by antiidiotype ELISA were approximately 10 micrograms/ml after administration of 0.5 mg/kg and approximately 50 micrograms/ml after treatment with 2 mg/kg of SDZ 89-104 or SDZ 89-109. High serum levels defined by antiidiotype ELISA techniques closely paralleled increased neutralizing activity. Serum half-lives calculated from these data were approximately 6 days.

Summary: Sodium diethyldithiocarbamate (DTC) was evaluated for its ability to combat four different species of fungi in vitro. Using a microtiter-broth-dilution method we were able to demonstrate an antifungal activity against Candida albicans, Cryptococcus neoformans, Aspergillus Qmigatus and Mucor mucedo in doses achievable by intravenous administration in man. Zusammenfassung: Die antimyzetische Wirkung von Diethyldithiocarbamate (DTC) wurde fur Candida albicans, Cryptococcus neoformans, Aspergillus fimigatus und Mucor mucedo in vitro mittels eines Bouillon-Reihenverdunnungstestes ge-pruft. Das Wachstum dieser Pilze wurde in vitro von DTC in Konzentrationsbereichen gehemmt, die beim Menschen nach intra-venoser Applikation erreichbar sind.

A total of 38 isolates of Candida albicans were collected from clinical specimens and tested for minimum inhibitory concentrations (MICs) and minimum fungicidal concentrations (MFCs) of amphotericin B, flucytosine and fluconazole. For amphotericin B and flucytosine all patients had isolates with MICs < or = 2 micrograms ml-1 and < or = 8 micrograms ml-1 respectively. For fluconazole all but two isolates had MICs < or = 16 micrograms ml-1. In vitro susceptibility testing remains problematic since standardized methods have not been established and the susceptibility and resistance ranges of MIC/MFC values still have to be defined in relation to in vivo data. Nevertheless, these results indicate that topical application of amphotericin B (more than 1 kg of amphotericin B per year at an intensive care unit performing selective digestive tract decontamination on certain trauma patients) had no major impact on the resistance patterns of C. albicans. In contrast, in this study both fluconazole-resistant isolates were from AIDS patients who were known to have received fluconazole therapy. Treatment with fluconazole--quite common in patients with AIDS--may produce resistant fungal isolates.

Since October 1986, all volunteer blood donors in the Tirol of Austria have been tested for neopterin. Serum neopterin levels were raised in 1242 donors (1.6%), 650 of whom (52.3%) consented to another test four weeks after the donation. In retrospect, 148 of these donors (22.8%) had an illness or abnormal symptoms at the time of donation or within a few days of it: according to the "guidelines for blood group testing and blood transfusion" of the Federal German Chamber of Doctors (Deutsche Bundesarztekammer) 25 of these (16.9%) should be permanently excluded as blood donors. The other 123 donors would have been temporarily excluded, according to the guidelines, if their illness had been known at the time of donation. Since the beginning of 1988, all donated blood with increased serum neopterin levels also had an IgM test for cytomegalovirus (CMV): nine of 243 samples tested (3.7%) indicated an acute CMV infection. The neopterin assay thus detects a variety of potentially harmful diseases or conditions which would not be revealed by the usually employed battery of routine tests.

Antibodies against HTLV-III, neopterin levels in blood and urine, TH/TS ratio and hepatitis marker were determined in 34 clinically symptom-free persons known to be intravenous drug abusers. 15 persons were positive in the ELISA and Western-blot tests. There was a strong reaction to protein p24 compared with that to protein p41. In 12 of 14 persons who were antibody-positive the neopterin level in morning urine was elevated; an abnormal TH/TS ratio was present in nine of 13 persons. In future, determination of neopterin and of antibodies against certain proteins of HTLV-III may make it possible to provide a simple way of prognosticating on the course of an HTLV-III infection.

This study investigated the in vitro effects of amphotericin B and amphotericin B colloidal dispersion (ABCD) on phagocytosis and inhibition of germination of clinical isolates of Aspergillus spp. by monocyte-derived macrophages (MDMs).Both amphotericin B and ABCD caused significant reductions in uptake of conidia of Aspergillus spp. by MDMs (p

Ovarian cancer is potentially well suited for local monoclonal antibody (mAb) immunotherapy, because it remains within the peritoneal cavity for a long period of time before giving rise to distant metastases. At the stage of minimal residual disease, the cells appear to be in a state of dormancy (G(0)) or at least have lower rates of tumour cell proliferation. They should be a promising target for immunotherapy. Here we first examined the cell-cycle expression of CD59 and decay-accelerating factor (DAF; CD55) on four different ovarian carcinoma cell lines, using simultaneous flow cytometric analysis of DNA content or the cell-cycle-specific nuclear proliferation protein Ki67 and CD59 or DAF surface expression. We found that CD59 and DAF are stably expressed throughout the cell cycle. The polyvalent approach to target-independent antigens to improve the efficiency of mAb complement (C)-mediated damages was promising, and tumour cells become sensitive to C damage, when incubated with cross-linked mAb against different tumour-associated antigens. Although, such immune complex-mediated C activation was rather ineffective in killing the cells, it could be potentiated by the addition of blocking mAb against CD59 and DAF. Our results suggest that the activities of intrinsic C regulators must be neutralized to make minimal residual disease a promising target for antibody therapy.

Summary We evaluated the utility of Aspergillus PCR as a tool in diagnosing invasive aspergillosis in patients at risk. Aspergillosis was assessed according to the European Organization for Research and Treatment of Cancer (EORTC), Mycosis Study Group definitions. Nine and seven patients with proven and probable aspergillosis respectively were evaluated. Whole blood samples prior (n = 41) and during antifungal treatment (n = 67), and tissue specimens (n = 9) and/or bronchoalveolar lavage fluids (n = 7) were investigated. In patients with proven infections, the sensitivities of PCR of lung samples were 100%, of blood samples prior treatment were 66%, and during treatment 55%. Clearance of fungal DNA from blood was associated with resolution of clinical symptoms in two of four patients with proven infection. Consecutive positive PCR results for Aspergillus are fatal as two of five patients died. In patients with probable infections, the sensitivities of PCR of lung fluids were 85%, of blood samples prior treatment were 57%, and during treatment 42%. The benefits of PCR diagnosing and screening of whole blood are limited if sampling takes place once treatment has started. The performance of Aspergillus PCR from tissue samples should be recommended in addition to microscopic examination and culture technique for sensitive detection of fungal infection. Zusammenfassung Um die Diagnostik von Aspergillus-Infektionen mittels Aspergillus-PCR zu bewerten wurde bei Risikopatienten mit hamatologischen Grunderkrankungen ein Aspergillus-Screening sowie die gezielte Untersuchung aus Biopsien durchgefuhrt. Evaluiert wurden neun Patienten mit nachgewiesener Aspergillose und sieben Patienten mit wahrscheinlicher Aspergillose. Die Bewertung der Pilzinfektionen erfolgte entsprechend der Klassifikation der European Organization for Research and Treatment of Cancer EORTC. Insgesamt wurden 108 Blutproben sowie 16 Lungenmateralien untersucht. Bei Patienten mit gesicherter Aspergillose betrug die Sensitivitat der PCR aus Lungengeweben 100%, aus Blut vor bzw. wahrend antimykotischer Therapie 66 und 55%. Eine Korrelation zwischen PCR-negativen Ergebnissen und Ansprechen einer antimykotischen Therapie zeigte sich bei zwei von funf Patienten. Eine Korrelation zwischen konsekutiv positiven PCR Ergebnissen und todlichem Ausgang zeigte sich ebenfalls bei 2 von 4 Patienten. Bei Patienten mit wahrscheinlicher Aspergillose betrug die Sensitivitat der PCR aus Lungengeweben 85%, aus Blut vor bzw. wahrend antifungaler Therapie 57 und 42%. Zusammenfassend ergibt sich, dass eine serielle Blutabnahme zur Diagnostik von invasiven Aspergillosen notwendig ist. Zur Beurteilung einer Infektion sollten zumindest zwei Blutproben vor Beginn einer antimykotischen Therapie vorhanden sein, um den Pilztrager eindeutig zu identifizieren. Unter antimykotischer Therapie korrelieren die Ergebnisse nicht immer mit den klinischen Befunden. Die Untersuchung aus Biopsien zeigt jedoch eine sehr hohe Sensitivitat und ermoglicht eine Speziesdiagnostik bei negativem kulturellem Ergebnis.

In order to ascertain the epidemiology of rubella infections in Austria, a seroepidemiological study was performed. Data collected from 115 cases diagnosed at the Institute of Hygiene and Social Medicine of the University of Innsbruck during 2001 were evaluated. The results indicate this infection can no longer be categorised as a paediatric disease (mean age, 18.5 years), and several other findings were particularly striking: (i) 47% of the patients had elevated C-reactive protein levels and 50% had increased anti-streptolysin O titres; (ii) only a few patients complained of fever, while symptoms such as rash and lymphadenopathy, which are also associated with several other viral infections, including HIV, were found frequently; and (iii) the 115 rubella cases detected in the 1-year study period represented an incidence of >13 per 100,000 population. This high incidence of infection underlines the need for further improvement of diagnostic tests and more successful vaccine strategies.

In den letzten Jahren ist eine Zunahme von opportunistischen Pilzinfektionen bei Patienten mit hamatoonkologischen Erkrankungen registriert worden. Eine zentrale Rolle spielen Infektionen durch Hefepilze wie Candida albicans und sog. Candida-non-albicans-Hefen, insbesondere jedoch durch Fadenpilze wie Aspergillus fumigatus und andere Aspergillus-Arten. Die Aspergillose stellt ein multifaktorielles Problem dar. Es muss davon ausgegangen werden, dass diese Pilzinfektionen nie vollstandig vermieden werden konnen, da Aspergillen ubiquitar vorkommen. Viele Erfahrungen zeigen jedoch, dass das Risiko einer Aspergillus-Infektion durch optimale Praventionsmasnahmen gemindert werden kann. Schutz pradisponierter Patienten vor einer Exposition gegenuber Pilzsporen, die Reduktion von Infektionsquellen und die fruhzeitige Erfassung einer Kolonisation sind Teil des Managements in der Infektionspravention. Als besondere Streuquellen gelten Baumasnahmen im Krankenhaus. Voraussetzung fur die zielgerichtete Etablierung von Schutzmasnahmen ist die genaue Kenntnis der Risikogruppen und der wichtigsten Risikofaktoren. Die Umsetzung spezieller Isoliereinrichtungen (high-efficiency air filtration system) zum Schutz der Patienten sollte Voraussetzung fur die Behandlung von Risikopatienten sein. Die umzusetzenden Masnahmen sollen die Pravention und fruhzeitige Erkennung von Infektionen entsprechend § 1 des Infektionsschutzgesetzes unterstutzen.

In order to evaluate the seroprevalence of human granulocytic ehrlichiosis in western Austria, sera from 357 Tyrolean blood donors were tested by an immunofluorescence assay. To assess the concomitant seroreactivity against Borrelia burgdorferi sensu lato, sera were further investigated by enzyme-linked immunoassay and Western blot. Thirty-two sera (9.0%) showed antibodies to Anaplasma phagocytophilum at a titre of 1:128 or higher, and 30 (8.4%) were seroreactive against Borrelia burgdorferi sensu lato. Infection with these two pathogens seems to occur in all Tyrolean districts except Landeck, the most upstream district of the Inn River Valley.

The aim of this study was to establish the incidence of fecal carriage of Listeria monocytogenes in healthy adults. A total of 868 stool specimens from three healthy volunteers (1 male and 2 females; ages 44, 39, and 60 years) were collected between 1 October 2000 and 30 September 2001. Culture was performed using Fraser broth and Palcam selective agar plates. Polymerase chain reaction (PCR) was performed using Probelia Listeria monocytogenes (BioRad, France). Overall, Listeria monocytogenes was detected in 31 of the 868 (3.57%) stool specimens using PCR. Sixteen of the 31 positive results were single events, i.e., samples collected from the same patient the day before and the day after the positive result were both negative. Positive results on two consecutive days were found four times, on three consecutive days one time, and on four consecutive days one time. Listeria monocytogenes was cultured from 10 of 868 (1.15%) stool specimens. These culture-positive samples, all positive by PCR as well, accounted for five independent episodes. Using automated ribotyping on up to 40 single colonies per stool specimen, 9 of 10 culture-positive samples yielded more than one strain. There was no obvious seasonal clustering of positive results. None of the documented episodes of Listeria monocytogenes carriage, all of which involved serotypes 1/2a and 1/2b, coincided with overt illness. The results of PCR indicate an incidence of five to nine exposures to Listeria monocytogenes per person per year. On average, the incidence of culture-confirmed fecal carriage in healthy adults is two episodes of Listeria monocytogenes carriage per person per year. Fecal shedding was of short duration (maximum 4 days), which argues against the appropriateness of routine stool screening in dairy workers as a tool for prevention of listeriosis.

This study investigated the fungicidal activity of selective serotonin reuptake inhibitors (SSRIs) against clinical isolates of Aspergillus fumigatus (n = 11), Aspergillus flavus (n = 9), Aspergillus terreus (n = 10) and Candida parapsilosis (ATCC 22019). The common drugs fluoxetine, seroxate, sertraline, paroxetine and reboxetine were applied in a broth microdilution test. In addition, we examined whether a post-antibiotic effect occurs following short exposure to the drugs. The various SSRIs showed time- and dose-dependent effects and were fungicidal towards the organisms tested. Sertraline and fluoxetine were the most active drugs, yet there were differences in the susceptibility of the various isolates tested. A lag of regrowth was dependent on the various SSRIs tested and their concentration. Treatment for 4 h at concentrations of sertraline below and equipotent to the minimal fungicidal concentration resulted in a lag of regrowth of 8-24 h for isolates of A. fumigatus and A. flavus. In conclusion, our in vitro studies clearly demonstrate antifungal effects of SSRIs. Animal studies are needed to evaluate the potential role of these psychotropic drugs in the management of fungal infections.

This review focuses on interactions of HIV with the first-line defence of native immunity, the complement system. In all body compartments tested so far, HIV meets complement. Activation of the complement system results in deposition of C3 fragments on the viral surface, but in contrast to other pathogens, most of HIV is not or is only poorly lysed by membrane attack complexes. To survive complement-mediated lysis, HIV has not only developed resistance mechanisms, but uses opsonisation with complement fragments for its own advantage. Opsonised virions interact with complement receptor-expressing cells, which are either subsequently infected with high efficiency or retain viral particles on their surface, which promotes transmission of virus to other permissive cells. Our knowledge of these mechanisms has increased enormously over the past few years. A complete understanding of these complex interactions of HIV with the complement system opens new perspectives for development of alternative therapeutic strategies.

The examples discussed above show the profound influence of HIV infection on expression pattern of cell surface proteins and the functional relevance thereof. Altered cell surface pattern is involved in all aspects of HIV-induced pathogenesis such as viral spreading viral adhesion and cellular apoptosis and is an important parameter for therapeutical approaches. The regulatory mechanism is not homogenous for all proteins but includes divergent effects like modulation of gene transcription and proteolytic cleavage. Modulation by viral infection might be either a direct or an indirect effect. Various viral proteins have been implicated in direct modulation like the regulatory proteins Tat, Nef and Vpu, but also the envelope proteins gp 120 and gp41. In addition, infection by HIV-1 has been shown to modulate expression of various cytokines including IL-10 and IFN-gamma. The altered expression of various surface proteins might be an indirect effect of cytokines acting on B cells, T cells and monocytic cells. By virus capture assays the presence of further proteins on viral surface was demonstrated indicating a possible function for viral life cycle. To study the modulation of expression of those additional important surface molecules by HIV and its biological function for the pathogenesis will be the aim of further studies in our laboratory.

Our previous results show that recombinant gp41 (aa565-647), the extracellular domain of HIV-1 transmembrane glycoprotein, stimulates interleukin-10 (IL-10) production in human monocytes. The signal cascade transducing this effect is not yet clear. In this study, we examined whether gp41-induced IL-10 up-regulation is mediated by the previously described synergistic activation of cAMP and NF-kappaB pathways. gp41 induced cAMP accumulation in monocytes in a time- and concentration-dependent manner and the adenylate cyclase inhibitor SQ 22536 suppressed gp41-induced IL-10 production in monocytes. In contrast, gp41 failed to stimulate NF-kappaB binding activity in as much as no NF-kappaB bound to the main NF-kappaB-binding site 2 of the IL-10 promoter after addition of gp41. We also examined the involvement of other signal transduction pathways. Specific inhibitors of p70(S6)-kinase (rapamycin), and Gi protein (pertussis toxin), prevented induction of IL-10 production by gp41 in monocytes, while inhibitors of the phosphatidylinositol 3-kinase (PI 3-kinase) (wortmannin) and mitogen-activated protein kinase (MAPK) pathway (PD 98059) did not. Thus HIV-1 gp41-induced IL-10 up-regulation in monocytes may not involve NF-kappaB, MAPK, or PI 3-kinase activation, but rather may operate through activation of adenylate cyclase and pertussis-toxin-sensitive Gi/Go protein to effect p70(S6)-kinase activation.

A set of 47 Austrian human, food, and veterinary Escherichia coli O157:H7 isolates was used to evaluate five different epidemiological typing methods. Ribotyping using an automated microbial characterization system (RiboPrinter ™ ) was not suitable for detection of epidemiological relatedness. All but one E. coli strain were typeable by phage typing. Random amplified polymorphic DNA-PCR fingerprinting was performed using primer M13 containing the sequence 5′-GAG GGT GGC GGT TCT-3′ and primer 1247 (5′-AAGAGCCCGT-3′). Although both methods recognized only two clusters, both dendrograms grouped most of the EHEC O157 isolates into epidemiologically related subgroups. Pulsed-field gel electrophoresis of Xba I digested total DNA was a valuable subtyping system. We found that major differences can exist between results of multiple subtyping methods. E. coli O157 isolates should not be classified as epidemiologically related or nonrelated on the basis of a single typing method alone.

Neopterin is a biochemical marker for the activation of the cell-mediated immune system. We measured neopterin, beta 2-microglobulin, and acute phase proteins in 31 HIV-seropositive and -seronegative Zambian patients with tuberculosis, using stored sera that had been obtained at the beginning and at end of antituberculosis treatment. In both HIV-seropositive and -seronegative patients neopterin and acute phase proteins were elevated when tuberculosis was initially diagnosed and fell during treatment. In contrast, the mean beta 2-microglobulin level increased during antituberculous therapy in the HIV-seropositive group. Serum neopterin levels at diagnosis were correlated with other parameters of disease activity (fever, anemia, and weight loss). In both groups, patients with persistently elevated neopterin levels at the end of treatment were more likely to suffer relapse of tuberculosis or other adverse health events in the subsequent follow-up period. Neopterin can be used to monitor the response to antituberculous therapy in both HIV-seropositive and -seronegative patients and may have a prognostic value for the patients' wellbeing in the follow-up period.

Complement receptor type 2 (CD21, CR2), the receptor for the C3 fragment C3dg, activates complement via the alternative pathway and also serves as a preferential acceptor site for C3 fragments. The molecular basis for this phenomenon, which has recently been demonstrated for B lymphocytes in vivo, is currently not understood. Here we present a model for this CR2-dependent complement activation. The inactive C3 (iC3), which forms spontaneously in serum in low amounts by reaction of native C3 with H2O, binds noncovalently to the N-terminal part of CR2. Subsequent association of properdin and factor B, and cleavage of factor B by factor D lead to formation of a C3 convertase associated with CR2, thus focussing covalent C3 deposition to CR2 itself. This model is supported by the following experimental findings. 1) By FACS analysis and radioreceptor assays we showed that iC3, properdin, and factor B bound to CR2 on Raji B cells, MT2 T cells, and peripheral blood B cells. 2) Both binding of these proteins and complement activation by CR2-expressing cells were reduced in parallel by Abs against CR2. 3) 125I-labeled C3b was covalently deposited on CR2, when hemolytically active 125I-labeled C3 was added to Raji cells preincubated with iC3, factor B, properdin, and factor D, thus proving functionality of CR2-bound C3 convertase. This model of C3 convertase activity formed on CR2 domains inaccessible for decay-accelerating factor offers an explanation for the deposition of C3 found on CR2-expressing cells.

We investigated the potential of CD21, the complement receptor type 2, to form receptor complexes with other membrane molecules on T cell lines. CD21 from T cell lines transformed with human T cell leukemia virus type I (MT2, HUT-102, C5.MJ, Mondi, and C91.PL) and T cell lines that were not virus transformed was analyzed by coprecipitation following cell lysis with digitonin. mAbs binding to functional and nonfunctional epitopes of CD21 and a polyclonal antiserum against its intracellular portion precipitated CD21, which was indistinguishable from CD21 on B cell lines. In contrast to B cells, where CD21 is complexed with CD19 and CD81 (target of anti-proliferative Ab 1) or, alternatively, with CD35 (CR1), no surface molecules could be coprecipitated with three of four mAbs from these T cell lines. Therefore, we assume that CD21 is not part of a preformed complex in T cell lines. OKB7, the only mAb directed against the functional C3d binding site, coprecipitated two proteins of 105 and 55 Mr with CD21 from MT2 and Mondi cells and from the T cell lines Jurkat E6-1 and SupT1. These bands were also recovered with CD21 precipitated from MT2 cells with C3d bound to Sepharose via the internal thioester, but were absent in CD21-expressing B cell lines. As C3d and OKB7 are functional ligands for B cells, we propose that upon ligation on T cells, CD21 associates with molecules of 105/55 Mr in the plasma membrane. Whether this is the first event of a signal delivered to the T cell is under current investigation.

The outer membrane glycoprotein gp120 and the transmembrane glycoprotein gp41 are predominant targets of the humoral immune response to infection by human immunodeficiency virus type 1. The third hypervariable region (V3 loop) is the principal neutralizing domain and is the primary target of neutralizing antibodies directed against the envelope proteins of HIV-1. The V3 loop is also the major determinant for HIV-1 cell-specific tropism. To further characterize the humoral immune response directed against the gp120 envelope proteins, we expressed two prototypic gp120 envelope proteins (LAI/HXB2 and ADA) and chimeric gp120 envelope proteins in stable transfected Drosophila melanogaster Schneider 2 cells. Sera from four infected adults over the course of infection [McNearney et al. (1992) Proc. natn. Acad. Sci. U.S.A. 89, p. 10,242] were assayed for reactivity with the respective envelope proteins. Sera obtained at early stages preferentially recognized the gp120 envelope protein ADA, whereas in later stages of infection the sera showed diminished reactivity with both gp120 LAI/HXB2 and gp120 ADA. Chimeric envelope proteins revealed that the humoral response was directed primarily against the V3 loop of gp120 ADA. Furthermore, 22 sera from HIV-1 infected individuals in different stages of the disease were tested. Reactivity of sera with the gp120 envelope protein ADA was seven-fold higher than with the gp120 envelope protein LAI/HXB2. Our results suggest that the humoral immune response is preferentially elicited against the V3 loop of the prototypic macrophage-tropic gp120 envelope protein ADA.

Tumor necrosis factor-alpha and the formation of reactive oxygen intermediates are central mediators of apoptosis. Recent data indicated a role of neopterin and 7,8-dihydroneopterin in oxygen radical mediated processes. We have therefore investigated the effect of neopterin-derivatives on TNF alpha induced apoptosis of the monocyte-like cell line U937. At an elevated concentration 7,8-dihydroneopterin was found to superinduce TNF alpha mediated programmed cell death due to the formation of reactive oxygen intermediates. Our results imply that in combination with TNF alpha high concentrations of 7,8-dihydroneopterin enhances apoptosis due to oxidative stress on cells.

Secretion of the C factors C7, C6, and C3 by human polymorphonuclear leukocytes (PMNs) and PBMCs was studied by ELISA and immunoblot. The release of C7 and C6 by PMNs during 24 h of culture was 16-fold and 6-fold higher, respectively, than the C3 release, with median concentrations of 50.2 ng/ml, 18.3 ng/ml, and 3.1 ng/ml, respectively. In PBMC cultures, C release was considerably lower, and there was a different secretory pattern with a 6-fold higher release of C3 compared with C7 and C6. Stimulation with PMA led to a more rapid and complete secretion of the components to the culture media, whereas treatment with unopsonized Candida species did not affect the release. PMN release of C factors was not dependent on protein biosynthesis, and there was no indication of a selective uptake of C7 from serum as demonstrated by incubating PMNs from a subject with allotype C7 N in C7 M serum. Thus, the C components were probably produced by the PMNs or their bone marrow precursors before ex vivo culture. In cell lysates of freshly isolated cells, median C7, C6, and C3 contents of 1 x 10(7) PMNs were 149.7, 60.1, and 10.4 ng/ml, respectively, whereas the corresponding values for 1 x 10(7) PBMCs were 3.2, 2.6, and 14.6 ng/ml, respectively. The C6 and C7 were shown to incorporate into the terminal complement complex, and their molecular integrity was supported by identical m.w. to C6 and C7 present in normal serum. PMNs may represent a major source of C7 and C6 and may be more important than monocytes or macrophages in contributing terminal C components at a site of inflammation. This suggests a new role for the PMN as a C membrane attack modulator.

Alterations in the expression of cell-surface receptors have been reported in HIV-infected cells for CD4, CD25 (IL-2 receptor), CD2, CD3 and CD8 and CD26. In the present study we provide evidence that CD21 is down-regulated in the human T-lymphoblastoid cell line MT2 after infection with HIV-1 and -2 isolates. The same effect was observed with ICAM-1 (CD54). CD21 expression was monitored by means of fluorescence intensity, its functional ability to bind to C3d and by quantitative measurement of CD21-antigen in supernatants and cell lysates using an immunoassay. In addition, the decrease of CD21 and ICAM-1-specific mRNA suggests a mechanism at a transcriptional level. Our data suggest that HIV might have a direct influence on the receptor expression.

Infection with Legionella is often encountered in immunosuppressed patients, especially in recipients of renal allografts. From January 1985 until April 1993 14 cases of nosocomial legionella pneumonia were diagnosed (four by culture, 10 by serological methods) on the surgical transplantation unit of Innsbruck University Hospital. All isolates from patients and from the building's hot water were found to be Legionella pneumophila serogroup 1. They were indistinguishable from each other by monoclonal antibody subtyping and restriction fragment length polymorphism pattern and thus indicated a series of infections originating from the same source during a period of more than 8 years. Repeated efforts to control Legionella by raising the temperature in the hot water lines failed to bring permanent success. Replacing the central hot water supply with small electric water heaters installed in the patient rooms on the transplant ward now seems to have reduced the incidence of legionellosis on this unit. However, further infections occurring in transplant patients in other surgical departments in the same building indicate that a major renovation of the whole surgical building's hot water system is necessary.

Gp41, the transmembrane glycoprotein of HIV-1, has been shown to be non-covalently associated with gp120. We have shown that it also binds human C1q. To analyze the interaction site(s) of gp41 with these two molecules, we established an enzyme-linked immunosorbent assay (ELISA) system using recombinant soluble gp41 [amino acids (aa) 539–684] and peptides thereof. In the cell-external part of gp41 three sites (aa 526–538, aa 590–613 and aa 625–655) were found to bind both gp120 and C1q. That gp120 and C1q use the same sites was evidenced by the fact that these proteins competed with each other for the same sites in recombinant soluble gp41 and gp41 peptides. It could be demonstrated by ELISA, that rabbit antibodies against human C1q recognized gp120, and rabbit antibodies against gp120 cross-reacted with C1q. Rabbit anti-gp120, HIV-1-positive human sera and anti-gp120 obtained from such sera agglutinated sensitized sheep erythrocytes with human C1q (EAC1q). These data suggest that in addition to functional homology between C1q and gp120 structural homology between these two molecules exists. This molecular mimicry might become the basis for immunologically relevant autoimmune phenomena.

The incidence of pulmonary tuberculosis among newspaper vendors, tram operators, and other exposed groups leads to repeated discussions about the importance of single cases for the spread of tuberculous infection. We subjected 36 strains of Mycobacterium tuberculosis, isolated in 1992 from 31 patients, to restriction fragment length polymorphism analysis using PvuII and an insertion element 986 probe. Only two isolates obtained from a married couple showed the same DNA fingerprinting pattern, all the other strains had unique and clearly distinguishable banding patterns. Our investigation revealed no dominating strains except in the case of one married couple, where the chain of infection was obvious (the wife being diagnosed during the course of testing of her alcoholic and tuberculous husband's contacts). The main emphasis in the fight against tuberculosis still rests on securing the availability of diagnostic and therapeutic means for all patients with tuberculosis. The importance of single infected source cases for the spread of tuberculosis should not be overestimated.

In the last several years, West Nile virus (WNV) was proven to be present especially in the neighboring countries of Austria, such as Italy, Hungary, and the Czech Republic, as well as in eastern parts of Austria, where it was detected in migratory and domestic birds. In summer 2010, infections with WNV were reported from Romania and northern Greece with about 150 diseased and increasingly fatal cases. We tested the sera of 1,607 blood donors from North Tyrol (Austria) and South Tyrol (Italy) for antibodies against WNV by using IgG enzyme-linked immunosorbent assay (ELISA). Initial results of the ELISA tests showed seroprevalence rates of 46.2% in North Tyrol and 0.5% in South Tyrol, which turned out to be false-positive cross-reactions with antibodies against tick-borne encephalitis virus (TBEV) by adjacent neutralization assays. These results indicate that seropositivity against WNV requires confirmation by neutralization assays, as cross-reactivity with TBEV is frequent and because, currently, WNV is not endemic in the study area.

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.

An in vitro model was used to study whether and how catheter infections can be cured. Silastic catheters were "infected" with Staphylococcus aureus ATCC 25923 and Staphylococcus epidermidis KH11 and V2; these "infections" were then treated with 24, 48 and 96 h continuous infusions of various antimicrobial agents administered both as monotherapy and in combination. The Staphylococcus aureus strain was considerably more difficult to eliminate from catheters than were the Staphylococcus epidermidis strains. This experience gained in the laboratory was then applied in vivo to 16 episodes of catheter sepsis in seven children. Treatment for at least six days with imipenem/cilastatin combined with fosfomycin or an aminoglycoside successfully eliminated the pathogens isolated from 11 of the 16 episodes of infection. The broad-spectrum combination was chosen because it could not be assumed that individual pathogens would be sensitive to a single substance. Nine of the infected catheters could be retained in the patients. This experience suggests that it may be possible to successfully eliminate the colonization of central venous catheters by coagulase-negative staphylococci using the antimicrobial agents employed here.

Antibodies against human immunodeficiency virus, other infectious agents and neopterin levels were determined in 253 patients in a rural area of North-West Tanzania. Seroprevalence for HIV was 3.2%. In one case serology was positive for HIV-1 and HIV-2 antibodies and questions whether there was a real double infection or a cross reaction not only concerning core region proteins but also transmembrane protein. The specificity in the diagnosis of HIV-infection is markedly increased with newer serological methods using recombinant peptides but did not improve sensitivity on African sera. Neopterin was determined as a sensitive indirect marker for the activation of T-cells and is therefore correlated with the susceptibility of HIV infection and with progression of disease. High seroprevalence rates for various infectious agents were determined and may explain the high rate of elevated neopterin levels in 80% of the Africans. Neopterin levels were even higher in HIV patients. Viral p24 antigen was found only in two persons, one of whom had no antibodies detectable.

Die Mehrheit der mit dem humanen Immundefizienzvirus Typ 1 (HIV-1) infizierten Personen ist frei von Symptomen oder weist nur persistierende Lymphadenopathie auf. Es ist notwendig, Risikokriterien für das Fortschreiten der Erkrankung zu erstellen, um zeitgerecht prophylaktische Maßnahmen einleiten zu können. Die Zahl der CD4-positiven Zellen ist ein geeigneter Prognoseparameter. Die Zellzählung ist jedoch aufwendig, teuer und Speziallabors vorbehalten, sodaß zusätzliche einfache Untersuchungen erwünscht sind, um die Risikoabschätzung weiter zu verbessern. Wissenschaftliche Untersuchungen ergaben, daß Neopterin und [beta]2- Mikroglobulin bei der HIV-1 Infektion gleich gute Prognoseparameter sind wie die Zahl der CD4-positiven Zellen; beide Parameter liefern darüber hinaus zusätzliche Infromation. Die Bestimmung der Meßgrößen erfolgt aus Serum (Neopterin und [beta]2-Mikroglobulin) oder Urin (Neopterin), wodurch das Risiko einer eventuellen HIV-1 Übertragung bei der Testdurchführung im Vergleich zur Bearbeitung von Vollblut, wie es zur Zellzählung benötigt wird, verringert wird. Auch wenn noch weitere Untersuchungen vor allem in Entwicklungsländern und in mit Zidovudin behandelten HIV-1 Infizierten notwendig sind, können Neopterin und [beta]2-Mikroglobulin als zusätzliche Parameter zur Abschätzung des AIDS-Risikos bei HIV-1 Infizierten empfohlen werden. Beide Meßgrößen sind auch dazu geeignet, die Bestimmung von CD4- positiven Zellen zu ersetzen, wenn die Möglichkeiten der Zellquantifizierung nicht gegeben sind., The great majority of individuals with human immunodeficiency virus type 1 (HIV-1) infection presents with no signs or symptoms, or only lymphadenopathy. To initiate prophylactic measures in time it is necessary to establish risk criteria. CD4+ cell counts are significant predictors. Supplementary methods to improve the predictive information of CD4+ cell counts are still required. In addition, CD4+ cell counting is laborious, expensive, and restricted to specialized laboratories. Thus, there is also a place for more easily performed laboratory tests with similar predictive value as CD4+ cell counts. Neopterin and [beta]2-microglobulin levels proved to be significant predictors of AIDS risk in HIV-1 seropositives. The predictive value of both parameters is equal to CD4+ cell counts and both markers are significant joint predictors in addition to CD4+ cell counts. Measurement of the parameters is done in serum (neopterin and [beta]2-microglobulin) or urine (neopterin) specimens which reduces the risk of HIV-1 transmission compared to handling of whole-blood samples as it is required for cell counting. Although more studies are needed, especially in developing countries and in persons receiving zidovudine, it can be recommended to use neopterin and [beta]2-microglobulin as additional marker to estimate AIDS risk in HIV-1 seropositive individuals. Moreover, both markers may be useful for this purpose without CD4+ cell counts if cell counting is not available.

Aspergillus terreus appears to have become an increasingly frequent cause of opportunistic infections in the University Hospital of Innsbruck (UHI) and is of serious concern because of in vivo and in vitro resistance to amphotericin B. In order to determine the possible relationship between environmental contamination by A. terreus and the occurrence of invasive aspergillosis, a 1-year prospective study (2004–2005) was carried out in the UHI. Isolates obtained from air samples of various high-risk settings and those from surveillance cultures of proven and probable aspergillosis (EORTC/MSG criteria) were examined by genotyping. Within 1 year, 34 and 15 A. terreus isolates were collected from the environment and from patients, respectively. Genotypic analysis with rapid amplification of polymorphic DNA (RAPD) PCR and the combination of three different primers (R108, CII, P4) revealed 46 distinct genotypic profiles (types 1–46). No strain similarity was detected among and within the patients and environmental areas, indicating a great genomic diversity in A. terreus, which is common in the environment of Innsbruck and a source of invasive infections in immunosuppressed patients. Genotypical diversity was found in clinical and environmental A. terreus isolates.

We investigated the ability of urinary neopterin concentrations and T-cell subset data, and their ratios to discriminate between anti-HIV-1 seronegatives, seropositives, and AIDS cases. Using receiver-operated-characteristics curves, neopterin levels were shown to provide the best discrimination. Of the ratios derived from the single variables, neopterin per CD4+ cell counts and neopterin per CD4+/CD8+ cell ratio were superior to the CD4+/CD8+ cell ratio. Multivariate analyses were performed using a generalized likelihood ratio approach as well as linear discriminant analysis. The combination of neopterin concentration and CD4+ T-cell count is well suited to discriminate between various stages of HIV-1 infection and, therefore, we recommend using more than one assay to evaluate disease progression.