Search PubMed⌕ Search

Biomedical subjects

H Wolf

Publications and source records attributed to H Wolf.

At least 253 records · Page 14Linked to original sources
PubMed1995

Nucleoprotein complexes and DNA 5'-ends at oriP of Epstein-Barr virus.

Understanding protein-DNA interactions in vivo at origins of DNA replication throughout the cell cycle may shed further insight on the mechanisms of initiation and replication control. The Burkitt's lymphoma cell line Raji harbors multiple copies of latent Epstein-Barr virus. Once per cell cycle the origin of plasmid replication of Epstein-Barr virus provides replication function in cis for the viral DNA. Here we examined in vivo nucleoprotein complexes on the initiator element of the origin before and after DNA synthesis. For this purpose Raji cells were synchronously growth arrested in G1 phase by mimosine and in mitosis by colchicine, respectively. The association of the initiator element with proteins was visualized by footprinting with dimethyl sulfate and ligation mediated polymerase chain reaction. Methylation patterns indicated a novel binding activity within each element of a nonamer repeated three times at the initiator element. This activity was strongly diminished in mitotic cells. Furthermore, 5'-ends of Epstein-Barr virus DNA were mapped to the nonamers by ligation mediated polymerase chain reaction, suggesting potential initiation sites for replication from DS.

Antigens, Viral↗
PubMed1995

Protection against EHV-1 challenge infection in the murine model after vaccination with various formulations of recombinant glycoprotein gp14 (gB).

Four formulations of the equine herpesvirus type 1 (EHV-1) glycoprotein gp 14 (gB), were tested for their ability to protect mice against intranasal (inas) EHV-1 challenge infection. The preparations tested included (i) a truncated gp14 produced in Escherichia coli or (ii) a truncated gp14 expressed in insect cells by a recombinant baculovirus, (iii) truncated gp14 coexpressed with human immunodeficiency virus type 1 (HIV-1) gag virus-like particles (VLP) in insect cells, and (iv) a gp14-DNA vaccine under the control of the cytomegalovirus immediate early promoter. All antigen preparations and the DNA vaccine elicited a humoral and delayed-type hypersensitivity (DTH) immune response to EHV-1 after intramuscular (im) immunization. After inas immunization, only the VLP-gp14 preparation produced both a good humoral and a prominent DTH immune response; gp14 expressed by insect cells elicited high titers of EHV-1-specific antibodies, whereas gp14 produced in E. coli and the DNA vaccine elicited only low antibody titers. Glycoprotein gp14 expressed by bacteria, however, induced a strong DTH reaction after inas application. Mice were completely protected against EHV-1 challenge infection after both the im and the inas immunization with the VLP-gp14 preparation. Protection was less efficient after immunization with the E. coli and insect cell gp14s as well as after DNA vaccination. Although the transmembrane domain of EHV-1 gp14 was deleted, recombinant gp14 could be demonstrated in insect cell membranes at late times postinfection and aggregated with the VLPs. It is suggested that the transmembrane domain is not required for gp14-association with membranes in that system.

Administration, Intranasal↗
PubMed1995

Natural killer cell activity in long-term survivors of testicular cancer. Influence of cytostatic therapy and initial stage of disease.

BACKGROUND: Patients with testicular cancer can be cured by cisplatin-based chemotherapy in many cases. Thus, concern about possible late toxicities of treatment is warranted. METHODS: In this investigation, the absolute number of natural killer (NK) cells according to their CD56+ phenotype, NK cell activity, and antibody dependent cellular cytotoxicity (ADCC) were investigated in 29 patients with seminomas or nonseminomatous germ cell tumors (NSGCT) a median of 31 months (range, 5-73 months) after termination of chemotherapeutic treatment. RESULTS: No difference in the absolute number of NK cells, NK cell activity, and ADCC was found between patients with testicular cancer after either standard polychemotherapy consisting of bleomycin, etoposide, and cisplatin (BEP) or monotherapy with carboplatin and healthy control subjects. When patients were analyzed further using multivariate analysis, a significant (P < 0.05) detrimental influence of BEP polychemotherapy versus carboplatin monotherapy on NK cell activity was found. Moreover, NK cell activity also depended significantly (P < 0.05) on the time elapsed after chemotherapy was administered, but normalized with time. Because the absolute number of NK cells was not affected, is was assumed that polychemotherapy induced a functional defect. In a subanalysis of patients with NSGCTs, metastases at diagnosis resulted in a significant (p < 0.05) and persistent stimulation of NK cell activity but not of ADCC. CONCLUSION: Cytostatic chemotherapy in patients with testicular cancer did not lead to compromised lytic effector cell function as assessed by NK cell activity and ADCC. However, a short, time-dependent reduction was found that also depended on the intensity of chemotherapeutic treatment. This finding related to the observation of a long-lasting stimulus of NK cell activity by initial metastases in patients with NSGCTs.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1995

Molecular profiling and weight determination of heparins and depolymerized heparins.

The recently proposed calibrant LHN-1 (lot F537; henceforth designated F537), for the molecular weight (MW) determination by high-performance size-exclusion chromatography of heparins, is shown here to have a range too narrow to allow for the accurate MW determination of all low molecular weight heparins (LMWHs). We have recently demonstrated, by this same methodology, that a chemically degraded benzyl ester of unfractionated heparin, heparin mass calibrator (HMC), is a better calibrant. Weight-average MW, number-average MW, peak MW, and dispersity values were calculated with F537, HMC, and by a reference narrow-range-calibration method for various LMWHs and unfractionated heparins. Values for these parameters determined with HMC were not significantly different from those determined by the reference method until the MW of the substance exceeded 15.0 kDa. In contrast, the MW profile obtained with F537 was appreciably different from that obtained by the reference method for samples with MWs > 7.5 kDa. The range exhibited by HMC should allow this calibrant to be used for both LMWHs and unfractionated heparins.

Heparin↗
PubMed1995

Pregnancy outcome after transcervical CVS with a flexible biopsy forceps: evaluation of risk factors.

The pregnancy outcome of 1936 women who had transcervical chorionic villus sampling (CVS) with a flexible biopsy forceps was evaluated. Follow-up until 4 weeks after delivery was 99.4 per cent. Various patient- and procedure-related risk factors for spontaneous loss (fetal or neonatal death) were analysed using stepwise logistic regression analysis. The overall spontaneous loss rate was 4.5 per cent. Factors found to be significantly associated with spontaneous loss were quantity of villi < or = 15 mg (relative risk (RR) 2.13), a history of first-trimester miscarriage (RR 1.87) or delivery between 16 and 27 weeks (RR 3.87), cervical culture positive for anaerobes (RR 4.52) or group B streptococcus (RR 3.62), post-procedural bleeding > 3 days (RR 1.99), and multiple insertions (RR 2.64). Significant differences in loss rates between individual operators were found. A learning effect was not present. There were no infants born with terminal transversal limb anomalies in our series. We conclude that knowledge about significant risk factors for spontaneous loss after CVS is important both for obstetricians carrying out CVS procedures and for women seeking prenatal diagnosis.

Adult↗
PubMed1995

Anti-ischemic effects of first and second dose of 20 mg isosorbide dinitrate administered 5 hours apart: attenuation of effects despite rising plasma concentration.

Based on evidence that there may be early tolerance development even within the first daily cycle of treatment, this study was undertaken to evaluate the duration and extent of the antiischemic effects of two 20 mg doses of isosorbide dinitrate as used in a well-established regimen documented to maintain effectiveness during long-term treatment. Ischemia parameters were analyzed at 2 and 4 1/2 hours after the first dose as well as at 2 and 7 hours after the second dose given 5 hours later. The studies were performed in 10 male patients with documented coronary artery disease using bicycle ergometry and a double-blind, randomized, placebo-controlled, crossover protocol. ST-segment depression was reduced by 59% (p < 0.0005) at 2 hours and by 42% (p < 0.01) at 4 1/2 hours after the first tablet and by 38% (p < 0.005) at 2 hours and by 15% (p < 0.05) at 7 hours after the second tablet. Increments in ischemia-free workload capacity amounted to 112% (p < 0.005) and to 41% (p < 0.05) after the first tablet and 68% (p < 0.05) and 38% (p < 0.05) at 2 and 7 hours after the second tablet. At 2 and 4 1/2 hours after the first tablet, plasma concentrations of isosorbide dinitrate were 8.4 and 5.9 ng/ml, and those of isosorbide-5-mononitrate were 166.6 and 130.3 ng/ml. At 2 and 7 hours after the second tablet, the concentrations of isosorbide dinitrate were 9.1 and 5.9 ng/ml, and those of isosorbide-5-mononitrate were 224.5 and 148.1 ng/ml.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1995

Malignant lymphomas induced by an Epstein-Barr virus-related herpesvirus from Macaca arctoides--a rabbit model.

Animal models for Epstein-Barr virus (EBV) are restricted to some species of new-world monkeys which develop malignant lymphoid tumours or benign lymphoproliferative diseases after virus inoculation. Similar pathological features were induced in rabbits by the EBV-related herpesvirus of Macaca arctoides (HVMA). In this study 17 of 32 rabbits infected with varying amounts of HVMA produced from MAL-1 cells developed lymphoproliferative disorders. In 13 rabbits high-grade malignant lymphomas were detected, 4 rabbits revealed the histopathological feature of lymphoid hyperplasia. These lymphoproliferations were shown to be associated with HVMA by PCR and by the expression of EBV-like RNAs (EBER) in 14 and 10 cases, respectively. The homology in the polymerase gene region between DNA from EBV and HVMA, and from HVMA and the malignant tissue was found to be 94.8% and 100%, respectively. All the infected animals produced antibodies to antigens corresponding to early and late EBV proteins. By studying the HVMA expression in MAL-1 cells EBV-like proteins expressed in latency (EBNA1 and EBNA2) and in the lytic cycle (VCA, EA) were detected. Our findings suggested that HVMA caused a symptomatic infection in rabbits with pathological features that fit the conditions of an animal model suitable for testing antiviral drugs and vaccines against EBV.

Animals↗
PubMed1995

A non-radioactive multiprime sequencing method for HIV genomes.

A manual non-radioactive DNA sequencing protocol was developed for rapid analysis of variable HIV-1 genomes. Sets of up to ten primers were used in one sequencing reaction. After polyacrylamide gel electrophoresis and blotting onto nylon membranes the individual sequences were detected by hybridization with digoxigenin-labelled oligonucleotides and chemiluminescence. The method is applicable to any sequencing project where numerous variants of DNA fragments of several 1000 bp of length are to be analysed.

DNA Primers↗
PubMed1995

Priming of class I-restricted cytotoxic T lymphocytes by vaccination with recombinant protein antigens.

We investigated the specific priming of MHC class I-restricted cytotoxic T lymphocytes (CTL) by different protein antigen preparations in mice. The recombinant viral protein antigens tested are of potential relevance for the design of subunit vaccines. They include the hepatitis B virus (HBV) surface antigen (S-antigen), the HIV-1 gp160 envelope protein, and a chimeric HIV-1 Pr55-gag/V3-3 retrovirus-like particle. In addition, ovalbumin (OVA) was tested. The native or denatured particulate (multimeric) or monomeric form of these protein antigens was injected by various routes into mice. Class I-restricted CTL were efficiently primed by a single low-dose injection of HBV S-antigen particles or the chimeric HIV-1 Pr55-gag/V3-3 particles. After SDS-denaturation, gel-purified monomeric S-antigen and monomeric Pr55-gag/V3-3 fusion protein were still very efficient in priming CTL. CTL sensitization was not detected in a (primary or boosted) response to even high doses of native OVA or native HIV-1 gp160. Denaturation of these two antigens by detergent strikingly increased their immunogenicity for CTL. Immunization of mice with non-treated or SDS-denatured antigenic peptides representing the relevant CTL-defined epitopes of the tested protein antigens did not prime CTL. These data indicate that native, particulate and denatured, monomeric protein antigens efficiently stimulate a class I-restricted CTL response.

Amino Acid Sequence↗
PubMed1995

Can finasteride reverse the progress of benign prostatic hyperplasia? A two-year placebo-controlled study. The Scandinavian BPH Study Group.

OBJECTIVES: To study if placebo-induced improvement in men with symptomatic benign prostatic hyperplasia (BPH) is maintained over 2 years, and to study the efficacy and safety from intervention with finasteride 5 mg for 24 months. METHODS: This was a multicenter, double-blind, placebo-controlled study involving 707 patients with moderate symptoms of BPH enrolled at 59 centers in five Scandinavian countries. Following enrollment and a 4-week single-blind placebo run-in period, patients were randomized to receive finasteride 5 mg once daily or placebo for 24 months. Urinary symptoms, urinary flow rate, prostate volume, postvoiding residual urinary volume, and serum concentrations of prostate-specific antigen together with laboratory safety parameters were measured at entry and at months 12 and 24. Interim physical and laboratory examinations were performed when indicated clinically. RESULTS: In finasteride-treated patients the total symptom score improved throughout the study, with a significant difference between the two groups at 24 months (P < or = 0.01), whereas in placebo-treated patients, there was an initial improvement in the symptom score but no change from baseline at 24 months. The maximum urinary flow rate decreased in the placebo group, but improved in the finasteride group, resulting in a between-group difference of 1.8 mL/s at 24 months (P < or = 0.01). The mean change in prostate volume was +12% in the placebo group versus -19% in the finasteride-treated group (P < 0.01). Finasteride was generally well tolerated throughout the 2-year study period. CONCLUSIONS: The efficacy of therapy with finasteride 5 mg in improving both symptoms and maximum urinary flow rate and reducing prostate volume has been shown to be maintained during 24 months while patients receiving placebo experienced a return to baseline or deterioration of these parameters during the study. These results demonstrate that finasteride can reverse the natural progression of BPH.

Aged↗
PubMed1995

The placental cause of fetal growth retardation in twin gestations.

The retardation of fetal growth in twin as compared to singleton gestations may be due to maternal and/or placental factors. The separate birthweights and related placental weights of 487 dichorial twin pairs were recorded, and the heavier placental weights of firstborns in comparison with second-borns were found to be related to the heavier birthweights of firstborns compared to second-borns. The lighter placental weights of firstborns compared to second-borns were found to be related to the lighter birthweights of firstborns compared to second-borns. Obviously, the placenta itself may may very well be the cause of the retardation of fetal growth in twin gestations.

Birth Order↗
PubMed1995

Antibodies to the nonstructural protein of parvovirus B19 in persistently infected patients: implications for pathogenesis.

Three patients with persistent parvovirus B19 infection, as documented by the prolonged presence of IgM directed to the viral capsid proteins and detection of viral DNA in serum by dot-blot hybridization or polymerase chain reaction (PCR), were investigated for the presence of antibodies to the nonstructural protein NS-1 of parvovirus B19. This was done by using an ELISA based on recombinant NS-1 protein. Whereas control sera displayed no reactivity, sera from persistently infected patients showed a strong specific antibody response to NS-1. Patients were followed for 3-18 months, during which IgM titers declined but IgG directed to the nonstructural protein remained detectable. The appearance of NS-1-specific antibodies might indicate an altered course of viral infection leading to the establishment of persistently active infection and subsequent destruction of cells of nonerythroid lineage.

Adult↗
PubMed1995

HLA-A0201 and HLA-B7 binding peptides in the EBV-encoded EBNA-1, EBNA-2 and BZLF-1 proteins detected in the MHC class I stabilization assay. Low proportion of binding motifs for several HLA class I alleles in EBNA-1.

B lymphocytes immortalized with EBV in vitro, lymphoblastoid cell lines (LCL), express eight EBV-encoded proteins, EBV nuclear antigens -1 to -6 (EBNA-1 to -6), and latent membrane proteins 1 and 2 (LMP 1 and 2). After appropriate stimulations of blood lymphocytes from seropositive individuals, MHC-restricted cytotoxic T cells (CTL), which lyse LCL cells, can be generated in vitro. Such CTLs can recognize EBNA-2 to -6, and LMP 1 and 2, but not EBNA-1-derived peptides presented on the cell surfaces. We posed the question whether this exceptional feature of EBNA-1 is due to lack of MHC class I binding peptides. A computer search for 11 human leukocyte antigen (HLA) alleles showed that EBNA-1 has a lower number and lower proportion of relevant binding motifs to several alleles than EBNA-2 to -6 and LMP 1 and 2. The low motif numbers in EBNA-1 is in line with its apparent failure to generate a CTL response, and it may be the consequence of immunoselection allowing the existence of EBV genome-carrying B cells in the immunocompetent hosts. The binding capacities of synthetic peptides of EBNA-1 and -2 and of the immediate early lytic cycle protein BZLF-1 to HLA-A0201 (A2) and HLA-B7 molecules were tested in an MHC stabilization assay. The peptide transporter-deficient T2 line, which expresses a low level of HLA-A2 and its HLA-B7 transfectant subline, were used for this purpose because specifically bound peptides elevate the surface expression of these MHC molecules. Of five synthetic nonamer EBNA-1 peptides which include the relevant binding motif, four bound to A2. In a series of 20-amino acid-long overlapping EBNA-1 peptides none showed binding to A2, while eight peptides bound to B7. Two 20-amino acid-long EBNA-2 and seven BZLF-1 peptides were identified as A2 binders, and four EBNA-2 and eight BZLF-1 peptides bound to B7. Thus, we have exclude the possibility that the inability of the EBNA-1 protein to generate HLA-restricted CTLs could be due to the lack of HLA class I binding peptides in its sequence. The finding that several EBNA-1 peptides could bind to these two HLa molecules does not, however, necessarily reflect the natural situation because the peptides may not be processed and/or transported to the cell surfaces. We have stimulated lymphocytes of healthy donors with relevant HLA types with the autologous LCL.(ABSTRACT TRUNCATED AT 400 WORDS)

Alleles↗
PubMed1995

In vivo P-31-MR-spectroscopy of focal hepatic lesions. Effectiveness of tumor detection in clinical practice and experimental studies of surface coil characteristics and localization technique.

RATIONALE AND OBJECTIVES: The influence of partial tumor sampling in a volume of interest (VOI) on the ratios of phosphorus metabolites was examined by localized phosphorus magnetic resonance spectroscopy (P-31-MRS). Experiments were performed to investigate the characteristics of the surface coil used and precession of spatial localization. METHODS: A total of 24 patients with liver metastases and 20 volunteers were studied by P-31-MRS. Patients were divided in two groups: VOI < 50% (n = 8) and VOI > 50% (n = 16) occupied by tumor. For evaluation of the surface coil and localization method (image selected in vivo spectroscopy), phantom studies were performed. RESULTS: Superficial focal liver tumors were detectable with a surface coil at a distance within the coil radius. The image selected in vivo spectroscopy permitted the study of phosphorus metabolism in a defined VOI, phosphomonoester/beta-adenosine triphosphate and phosphodiester/beta-adenosine triphosphate were elevated significantly in spectra of both patient groups. CONCLUSIONS: Detection of small tumor volumes within a VOI filled by less than 50% of the tumor is possible, with results statistically different from that in normal volunteers.

Adult↗
PubMed1995

111In-octreotide imaging in patients with long-standing Graves' ophthalmopathy.

The aim of this study was to examine patients with long-standing Graves' ophthalmopathy using 111In-octreotide scintigraphy. Sixteen patients with inactive ophthalmopathy of up to 114 months duration and 14 normals were investigated for 48 h following an injection of 200 MBq 111In-octreotide. No significant tracer accumulation in the orbital region could be identified in any of the patients with long-standing Graves' ophthalmopathy. The orbit to brain (O/B) ratios after 24 and 48 h were 2.39 +/- 0.36 and 2.15 +/- 0.44 versus 2.17 +/- 0.33 and 2.20 +/- 0.37 for the patients and normals, respectively (N.S.). 111In-octreotide accumulation in ophthalmopathy described in the literature may thus be a passing event limited to its active stage, which is consistent with the concept of imaging a lymphocytic infiltration. In this study, the lack of accumulation of 111In-octreotide in the orbital region during the inactive stage demonstrates an absence of somatostatin receptors in orbital tissue itself. Thus, in patients with inactive Graves' ophthalmopathy, there is no basis for a diagnostic approach with somatostatin.

Case-Control Studies↗
PubMed1995

Value of quantitative salivary gland scintigraphy in the early stage of Sjögren's syndrome.

The aim of this study was to test the impact of quantitative salivary gland scintigraphy in patients with suspected Sjögren's syndrome. Thirteen patients with suspected Sjögren's syndrome were investigated. During clinical work-up, three had severe and four had mild Sjögren's syndrome, while six were normal. Quantitative salivary gland scintigraphy was performed using a standardized method. The normal data-base consisted of 172 patients without any evidence of salivary gland malfunction. Visual and quantitative comparisons of the patients' scintigrams were made. In the patients with severe Sjögren's syndrome, uptake was 0.10 +/- 0.04% and 0.09 +/- 0.03% in the parotid and submandibular glands respectively, confirming the visual diagnosis. In the patients without Sjögren's syndrome, concordance between the visual and quantitative evaluations could also be shown. In contrast, among the patients with mild Sjögren's syndrome, uptake was diminished (P < 0.05), amounting to 0.21 +/- 0.05% and 0.16 +/- 0.02% in the parotid and submandibular glands respectively, while visual analysis indicated normal parenchymatous function. In conclusion, quantitative salivary gland scintigraphy is essential for the reliable detection of parenchymatous malfunction at an early stage of Sjögren's syndrome, which may be missed by visual analysis alone.

Adult↗