Search PubMed⌕ Search

Biomedical subjects

H W Doerr

Publications and source records attributed to H W Doerr.

At least 145 records · Page 8Linked to original sources
PubMed1994

Suspension culture of HeLa cells in protein-free medium: sensitivity to human pathogenic viruses.

Human adherent HeLa-PF cells grown for 5 years in a protein-free 1:1 nutrient mixture of Dulbecco's modified MEM and Ham's F12 (DMEM-F12) were established in suspension culture. The cells grew in protein-free DMEM-F12 (using magnetically stirred flasks) as a monodisperse suspension with a population doubling time of 28 h. The cells were infected with poliovirus types 2 and 3, herpes simplex virus types 1 and 2 (HSV-1 and HSV-2), respiratory syncytial virus (RSV), echovirus 6 and adenoviruses 3 and 7. Polioviruses replicated in suspension culture of HeLa-PF cells to a similar extent as in protein-free and serum-supplemented adherent cultures. RSV and HSV developed significantly lower titers while adenoviruses and echovirus 6 developed significantly higher titers in suspension than in adherent cultures. The results show that suspension culture of HeLa-PF may both provide the advantage of a high virus yield and enable cultivation of viruses which are not contaminated by serum or other proteins usually added to the culture medium.

Cell Culture Techniques↗
PubMed1994

Diagnosis and epidemiology of transfusion-associated human cytomegalovirus infection: recent developments.

OBJECTIVE: The prevention and diagnosis of transfusion-associated HCMV infection has to address different questions: Is the blood donor potentially infections? Is the transfused recipient undergoing an active primary or secondary infection? DATA SOURCES: International literature (Current Contents Life Sciences) and reports of our study-group. SELECTION CRITERIA: Original articles in English and German. RESULTS: Monocytes have been identified as the major site of latency of human cytomegalovirus (HCMV) in peripheral blood. High seropositivity rates are observed in polytransfused individuals, intravenous drug users, organ transplant recipients, maintenance hemodialysis patients, homo/bisexuals and prostitutes. Although, there have been important developments in order to improve the sensitivity of the ELISAs for the diagnosis of active HCMV infection, serologic testing often fails to detect IgM and IgA antibodies in immunocompromised patients. Rapid virus isolation, structural antigen detection and DNA amplification by PCR in peripheral blood monocytes have considerably improved diagnosis of acute HCMV infection in neonates, organ transplant recipients and AIDS patients. Due to the low correlation of HCMV DNA detection and HCMV disease, PCR testing is actually not recommended for the monitoring of high risk patients and screening of infectiosity of blood components. CONCLUSIONS: As a consequence numerous improvements in serological, virological and molecular methods, a more efficient prevention and diagnosis of transfusion-associated HCMV infection has become possible.

Blood Donors↗
PubMed1994

In vitro anti-human cytomegalovirus activity of liposome-encapsulated foscarnet.

Foscarnet is a pyrophosphate analogue that possesses substantial activity against human cytomegalovirus (HCMV) in patients with CMV retinitis. In this in vitro study we tested whether liposome encapsulation of foscarnet would provide the drug with anti-HCMV activity comparable with that of nonencapsulated foscarnet. The drug was entrapped in large unilamellar vesicles of homogeneous size at a concentration of 10 mg/ml. The vesicles were prepared by the method of fast and controlled dialysis of mixed detergent-lipid micelles using N-Octyl--D-glucopyranoside as the detergent. The activity of drugs against two laboratory HCMV strains (AD169 and Towne) was tested in a plaque-reduction assay using monolayers of human foreskin fibroblasts. The dose of encapsulated or nonencapsulated foscarnet required for a 50% reduction in the number of plaques (IC50) for the AD169 strain was 106 and 113 mumol/l, respectively. For the HCMV Towne strain the dose was 112 and 109 mumol/l, respectively. Treatment with concentrations of up to 400 mumol/l (maximal concentration tested) demonstrated that foscarnet is released at efficient doses from liposomes and that it is not toxic in the range of concentrations tested.

Cells, Cultured↗
PubMed1993

[Incidence of Lyme borreliosis in a rheumatologic patient sample. Study of 153 patients of an internal medicine-rheumatologic ambulatory clinic].

PROBLEM: Arthritis of the large joints is considered a typical manifestation of Lyme disease. With an estimated incidence in the population of about 2%, Lyme disease arthritis would be expected to be a fairly common diagnosis in a rheumatology unit. METHODS: In 153 successive patients seen in a rheumatology clinic of the University Hospital Frankfurt am Main, who had historical or clinical evidence of arthritis, the IgG antibody titers against Borrelia burgdorferi in the serum were compared with the clinical presentation. RESULTS: Twelve patients had positive or borderline positive antibodies titers. In three of the 153 patients, the diagnosis of Lyme disease-associated arthritis appears possible, although not probable. CONCLUSIONS: At least in the greater area of Frankfurt, Lyme disease as a differential diagnosis of arthritis is apparently of no great significance.

Adolescent↗
PubMed1993

In vitro differentiation of human neuroblastoma cells induced by sodium phenylacetate.

Sodium phenylacetate (NaPA) at concentrations ranging from 2 to 6 mM stimulated morphological differentiation of two human neuroblastoma cell lines IMR-32 and UKF-NB-3. These concentrations inhibited growth and DNA synthesis of the cells in a dose dependent manner without significant effect on cell viability. The differentiated cells showed pseudoganglia formation and extension of cellular processes. The morphological differentiation in both cell lines was accompanied by decreased expression of N-myc oncoprotein. These results suggest that NaPA at concentrations, which have been achieved in humans with no significant adverse effects, promotes differentiation of cultured human neuroblastoma cells in association with the reduced expression of the malignant phenotype.

Cell Differentiation↗
PubMed1993

Detection of neutralizing antibodies against human cytomegalovirus: influence of strain variation.

The influence of human cytomegalovirus (HCMV) strain variation on neutralizing antibody titers was investigated in sequential sera obtained from 12 organ transplant recipients (11 renal transplant recipients, 1 liver transplant patient) suffering from primary or secondary HCMV infection. Cross-neutralization assays using either the international HCMV reference strain AD169 or individual clinical isolates from patients showed congruent results. Restriction enzyme analysis of the hypervariable alpha-sequence of the L-S junction of AD169 and HCMV isolates amplified by polymerase chain reaction (PCR) were carried out to confirm the expected strain differences. At least 6 groups of clinical strains were differentiated. The results of this study demonstrated that despite the strain heterogenicity of HCMV, the neutralization assay using AD169 permitted a reliable and quantitative serologic detection of neutralizing antibodies against HCMV.

Antibodies, Viral↗
PubMed1993

Contamination of genetically engineered CHO-cells by epizootic haemorrhagic disease virus (EHDV).

The characterization of a contaminating virus which was detected in genetically-engineered Chinese hamster ovary (CHO) cells during the production of biologicals is described in the present paper. Under electron microscopy, the contaminating virus had a morphology resembling that of an orbivirus. The relationship was confirmed by nucleic acid analysis which showed a RNA segment pattern characteristic of orbiviruses. With an immunoperoxidase staining of monolayer cells and through sero-neutralization tests the virus was identified as being identical to Epizootic Haemorrhagic Disease Virus (EHDV), isolate 318 (untyped) from Bahrain. Potential sources of the contaminating virus and feasible procedures to avoid adventitous virus infections in cell cultures are discussed.

Animals↗
PubMed1993

Protein-free culture of Vero cells: a substrate for replication of human pathogenic viruses.

A protein-free chemically defined medium designated PFEK-1 was developed for culture of VERO cells on polyvinyl formal (PVF) culture surface without serum or other macromolecular supplements. VERO cells proliferated in PFEK-1 medium on PVF surface to a similar extent as cells in serum-supplemented medium without previous adaptation from serum-containing conditions. The protein-free culture infected with coxsackievirus B4, herpes simplex virus types 1 and 2, measles virus and poliovirus types 1, 2 and 3 developed viral titers comparable to those found in conventionally grown cells. The results demonstrated that VERO cells in protein-free culture provide a sensitive substrate for the production of human pathogenic viruses which are not contaminated by serum or other protein factors usually added to a culture medium.

Animals↗
PubMed1993

Humoral immune response to human cytomegalovirus infection: diagnostic potential of immunoglobulin class and IgG subclass antibody response to human cytomegalovirus early and late antigens.

For the development of effective prophylaxis (hyperimmune globulins) and improvement of serological testing for human cytomegalovirus (HCMV) infection in immunocompromised patients it is essential to characterize the viral encoded proteins and the humoral immune response in terms of neutralizing antibodies and immunoglobulin class and IgG subclass reactivity to "early" and "late" HCMV proteins. The major neutralizing epitopes have been identified and screening of donor sera for neutralizing antibody by either conventional neutralization assays or enzyme-linked immunosorbent assay using recombinant antigens may help to improve the efficacy of hyperimmune globulin prophylaxis. The humoral response to individual HCMV proteins has been thoroughly investigated in immunocompromised patients. Antibodies against HCMV induced "early" antigens are not exclusively associated with active infection but may indicate an elevated risk for cytomegalic inclusion disease in immunocompromised patients. With a sensitive western blot technique. IgM and IgA antibodies against HCMV "late" proteins can be detected in sera from healthy seropositive individuals. Serum samples from subjects suffering from cytomegalic inclusion disease show significantly larger broader immune responses compared with healthy HCMV antibody carriers. Promising results using recombinant antigens corresponding to immunodominant epitopes for the detection of HCMV specific antibodies have been published.

Antibodies, Viral↗
PubMed1993

Evaluation of the automated 'Enzymen-Test Anti HIV-1 + 2' and 'Enzymen-Test Anti HIV-1/2 selective' for the combined detection and differentiation of anti-HIV-1 and anti-HIV-2 antibodies.

A new, modular automated ELISA (test 1) for HIV-1 and HIV-2 antibody detection and differentiation (Enzymun-Test Anti HIV-1 + 2; anti HIV 1/2 selective, Boehringer Mannheim) was compared with 3 alternative enzyme immunoassays (Abbott recombinant HIV-1/HIV-2 3rd generation EIA, Abbott (test 2); Enzygnost HIV 1 + 2, Behringwerke (test 3); and Wellcozyme HIV recombinant, Murex (test 4)) and Western blot (New LAV I Blot and New LAV II Blot; Diagnostics Pasteur). 380 serum samples from HIV-1 and HIV-2 seropositive patients at different stages of disease, high risk individuals, patients with conditions unrelated to AIDS and from healthy blood donors were used in this evaluation along with 6 seroconversion panels, 6 serum dilution series and 'tricky' sera (repeatedly positive results in ELISA, but negative or undeterminate in Western blot; n = 67). Using the Western blot as reference assay, the overall sensitivity of the four ELISAs was 100%. Test 4 showed the highest sensitivity for antibody detection in seroconversion and dilution series. A high specificity was achieved with test 1 (100%) and test 2 (99.4%). A relatively high rate of false positive results were obtained with test 2 (n = 12) and test 3 (n = 10) by testing 'tricky' sera or samples obtained from healthy blood donors. In comparison to Western blot, a clear differentiation between HIV-1 and HIV-2 antibody serum samples was achieved with the Enzymun-Test. The results of the present study show that the Enzymun-Test provides reliable selective HIV-1 and HIV-2 antibody detection at a cost which is significantly lower than the costs of Western blot tests. Furthermore, the evaluation of test 1 suggests, that it is a highly specific assay for HIV antibody detection.

AIDS Serodiagnosis↗
PubMed1993

Immunoglobulin A and M patterns to human cytomegalovirus during recurrent infection in patients with AIDS using a modified western blot.

Immunoglobulin A and M patterns to human cytomegalovirus (HCMV) were investigated in sera from actively HCMV infected AIDS patients (n = 61) and healthy HCMV seropositive controls (n = 28) by a Western blot method (modi-blotting) and ELISA. The Western blot showed a higher detection rate for both IgA (78.7% vs. 52.5%) and IgM (83.6% vs. 13.1%) than ELISA in the immunocompromised patients suffering from active HCMV infection. Of the healthy seropositive individuals, 35.7% and 21.4% had a weak positive IgA- and IgM-class antibody reactivity respectively with HCMV-specific bands in the immunoblot. Immunoglobulins M and A were not detected by ELISA in the healthy control group. Immunoreactions in this group were restricted to viral polypeptides with M(r) of 68 kDa and 123 kDa. Additional bands were found in the actively infected patients only and were observed more frequently with IgA than IgM (47.5% vs. 29.5%). Results from the present study indicate, that using a sensitive Western blot technique, a higher serologic detection rate of active recurrent infection is achieved in AIDS patients. Nevertheless, immunoglobulin A and M are detected in a certain percentage of HCMV-seropositive healthy individuals not suffering from active HCMV infection. Broader immune reactions of HCMV-IgA as determined by HCMV Western blot assay are associated with an active infection, but were not present in all the actively infected patients.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Evaluation of the automated VIDAS system for the detection of anti-HIV-1 and anti-HIV-2 antibodies.

A new, modular 'walk away' system for HIV 1 and HIV 2 antibody detection (VIDAS HIV 1 + 2 enzyme linked fluorescent assay) was compared with EIAs (Wellcozyme HIV recombinant, Wellcome; and Enzygnost HIV 1 + 2, Behringwerke) and Western blot (New LAV I Blot; Pasteur). 434 serum samples from HIV seropositive patients at different stages of disease, individuals at high risk, patients with conditions unrelated to AIDS and healthy blood donors were used for this evaluation together with 4 seroconversion panels, 4 serum dilution series and 'difficult' sera (repeatedly positive results in EIA, but negative or indeterminate by Western blot; n = 87). With the Western blot as the reference assay, the overall sensitivity of VIDAS HIV 1 + 2 and the alternative EIAs was 100%. Significant differences in sensitivity between the 3 EIAs were not observed for the antibody detection in the seroconversion panels and the dilution series. The specificity of VIDAS HIV 1 + 2, Enzygnost and Wellcozyme were 93.5%, 89.6% and 92.4% respectively if Western blot strips were interpreted according to CDC-criteria. A high rate of false positive results was obtained with the 3 EIAs since serum samples were not selected randomly and a large collective of 'difficult sera' was investigated. So-called 'walk away' systems like VIDAS HIV 1 + 2 offer a rapid screening for HIV antibody detection for routine laboratory diagnosis.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Detection of IgM antibodies against coxsackie B viruses by a western blot technique.

We report the application of a modified Western blot (WB) micromethod basically relying on a diffusion-blotting technique (Modi-blot) combined with an immunological detection system using monoclonal antibodies and a biotinavidin amplification step for the detection of IgM antibodies against coxsackieviruses B1 (CBV1), CBV2 and CBV4. Fifty-one adult patients with clinical signs of coxsackievirus B infection (e.g. myocarditis and meningitis) were investigated. The test revealed a total of 31 (60%) IgM positives. The majority of IgM antibodies were group reactive (22/31). Type-specific antibodies could be recognized in 9 cases (3 with CBV1, 5 with CBV2 and 1 with CBV4). The highest rate of antibody prevalence was found in sera from patients with acute meningitis (12/14). Controls [healthy adults (n = 13) and individuals with other infections (n = 13)] were all negative for specific IgM against coxsackievirus B1, B2 and B4. Further WB tests of 8 IgM positive specimens with coxsackievirus B4 revealed specific IgA responses in all cases, reinforcing the evidence for a recent infection. In addition, the patterns of IgG antibody subclasses, also investigated in this group, showed a clear predominance of specific IgG1 and IgG3 antibodies.

Acute Disease↗
PubMed1993

Decreased anti-human immunodeficiency virus type-1 activities of 2',3'-dideoxynucleoside analogs in MOLT-4 cell sublines resistant to 2',3'-dideoxynucleoside analogs.

Human T-lymphoid MOLT-4 cells were grown continuously for more than 1 year in medium containing either 3'-azido-2',3'-dideoxythymidine (AZT), 2',3'-dideoxyinosine (ddI) or 2',3'-dideoxycytidine (ddC) at concentrations similar to peak plasma levels found in clinical trials in patients with AIDS. To test antiviral activities of the nucleoside analogs against HIV-1 in the cell sublines designated MOLT-4r-AZT, MOLT-4r-ddI and MOLT-4r-ddC, the number of infected cells, p24 HIV-1 antigen in culture medium and syncytium formation of infected cultures were determined. The results showed that anti-HIV-1 activities of AZT, ddI and ddC were significantly decreased in the resistant MOLT-4 cell sublines grown continuously with the respective nucleoside analog, probably due to the development of cell populations resistant to the drugs.

Cell Line↗
PubMed1993

In vitro anti-human immunodeficiency virus activity of 2',3'-dideoxynucleosides and their effect on clonal growth of hemopoietic cells from human bone marrow.

Seven 2',3'-dideoxynucleosides synthesized by substitution of nucleosides using nucleoside deoxyribosyltransferase from Lactobacillus leichmanii were tested for their anti-human immunodeficiency virus (HIV) activity. Two of them, including 2,6-diaminopurine-2',3'-dideoxyriboside (DAPDDR) and 6-chlorpurine-2',3'-dideoxyriboside (CPDDR) demonstrated high antiviral activity against several strains of HIV-1 and one strain of HIV-2. The selectivity index of the drugs (SI; ratio of the drug concentration required for 50% of cell killing to drug concentration required to inhibit 50% of virus-induced cell killing) was established by application of tetrazolium (MTT) colorimetric assay. SI ranged for different HIV strains from 501 to 850 and from 60 to 118 for DAPDDR and CPDDR, respectively. Both DAPDDR and CPDDR retained their antiviral activity against HIV-1 strain D148/88 which was resistant to Zidovudine (3'-azido-3'-deoxythymidine, AZT). Assays for clonal growth of human bone marrow cells in semisolid fibrin clot culture medium demonstrated that DAPDDR possesses significantly lower inhibitory activity for erythroid (BFU-E), multipotent (GEMM-CFC) and granulocyte-monocyte (GM-CFC) bone marrow progenitor cells than CPDDR or AZT. These results suggest that DAPDDR is a nucleoside analog which should be further tested as an anti-HIV compound especially in combination with other anti-retroviral drugs.

Antiviral Agents↗
PubMed1993

[Results of studies from the AIDS counseling center of the Frankfurt/M. city health office January 1990 to December 1991].

Between January 1990 and December 1991 5854 clients entered the AIDS-Counselling Service of the Municipal Health Department in Frankfurt/M; 1997 (34%) of them were female and 3857 (66%) male. In 5228 cases blood samples were examined for HIV-antibodies and the prevalence of positive tests was 84 (1.6%). Among the subjects who were seropositive for HIV, 51 (61%) were homosexual, 9 (11%) bisexual and 11 (13%) heterosexual men, furthermore 5 (6%) heterosexual women. 8 (9%) seropositive persons were intravenous drug abusers (5 male, 3 female). With the aid of an anonymous questionnaire that was filled in voluntarily by the clients, information about the sexual anamnesis, reasons for wanting the test, and whether they had been already tested for HIV in the past, could be gained. During the examined period, safer sex has been practiced by 414 (58%) of 712 homosexual men and by 1183 (24%) of 4867 heterosexuals (2923 male, 1944 female). By reason of a new partner 141 (19%) homosexuals and 1261 (26%) heterosexuals wanted to be tested for HIV; 529 (74%) homosexuals and 1806 (37%) heterosexuals had been already tested for HIV in the past. Summing up we can state, that the large attendance of the AIDS-Counselling Service, now as before, could be traced back to great acceptance and trust placed the population in the Municipal Health Department. HIV-testing is accepted by heterosexual and homosexual couples as well, and often performed at the beginning or at the end of a partnership. Safer-sex plays, now as before, a subordinate role among heterosexuals in comparison to homosexuals.

AIDS Serodiagnosis↗