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W Zeller

Publications and source records attributed to W Zeller.

At least 73 records · Page 4Linked to original sources
PubMed1990

Mode of replication of lymphocytic choriomeningitis virus in persistently infected cultivated mouse L cells.

During persistent infection of mouse L cells with strain Armstrong lymphocytic choriomeningitis virus, the latter undergoes characteristic changes, including loss of mouse pathogenicity and failure to form plaques on cultivated cells. We call this virus L(Arm) and have analyzed transcription and translation of its S-RNA, which codes for the viral nucleoprotein (NP) and the glycoprotein precursor (GP-C). In L(Arm) virus-infected L cells, S-RNA and genomic-sized viral complementary S-RNA (VC-S-RNA) were detected and, in addition, considerable quantities of shortened molecules of either species. The cells' content of NP was high, but they contained little GP-C; instead, a viral glycoprotein with MW 65,000 was present. We propose a hypothesis in which it is assumed that along the VC-S-RNA there is more than one recognition site for the viral RNA-dependent RNA polymerase, which leads to the generation of truncated forms of S-RNA, VC-S-RNA, and mRNA for GP-C; this, in turn, results in relative overproduction of NP and relative underproduction of GP-C as well as the emergence of a new form of viral glycoprotein.

Animals↗
PubMed1990

Sequential versus alternating chemotherapy for high-grade non-Hodgkin's lymphomas: preliminary results of a phase III multicentre trial.

In a multicentre phase III trial 105 previously untreated patients with high-grade non-Hodgkin's lymphomas stage II-IV were randomized to receive either 4 cycles of CHOEP (cyclophosphamide 750 mg/m2 i.v. day 1, doxorubicin 50 mg/m2 i.v. day 1, vincristine 2 mg i.v. day 1, etoposide 100 mg/m2 i.v. days 3-5, prednisolone 100 mg p.o. days 1-5) (treatment arm A), or 4 cycles of chemotherapy with hCHOP (cyclophosphamide 1,200 mg/m2 i.v. day 1, doxorubicin 40 mg/m2 i.v. days 1 + 2, vincristine 2 mg i.v. day 1, prednisolone 100 mg p.o. days 1-5) alternating with IVEP (ifosfamide 1,500 mg/m2 i.v. days 1-5, vindesine 3 mg/m2 i.v. day 1, etoposide 120 mg/m2 i.v. days 3-5, prednisolone 100 mg p.o. days 1-5) in treatment arm B. After 4 cycles of chemotherapy an involved field irradiation with a total dose of 35 Gy was given to all patients demonstrated to be in complete or partial remission without persisting extranodal disease. A complete response (CR) was seen in 86/105 patients (82%) with 88% CR in arm A vs. 76% CR in arm B. During a median follow-up of 11 months (range 2-31 months) 13 patients relapsed (6 patients arm A, 7 patients arm B). The overall survival at 30 months is projected to be 72% vs. 83% for arm A and B respectively. Disease-free survival is projected to be 78% in arm A and 45% in arm B at 28 months. So far, the differences in CR, survival and disease-free survival are not statistically significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1989

[The humanitarian stunning of fowl for slaughter with microwaves (2450 MHz)].

Chickens can be killed in less than one second by exposing their heads to microwave irradiation with a frequency of 2450 MHz. Positioning the head exactly is necessary. The only way to avoid this handling is the exposure of the whole body. But because of a particular high rate of absorption the wings are heated so that the meat is not edible any more. Before slaughtering the chickens are hung up headlong. This causes increased cardiac and respiratory frequencies while the blood pressure is not altered yet. This handling is a considerable stress. Animal-prevention arguments suggest to prefer anaesthesia before hanging the chickens in the conveyor belt.

Abattoirs↗
PubMed1988

Lymphocytic choriomeningitis virus. X. Demonstration of nucleoprotein on the surface of infected cells.

Of a total of 17 monoclonal antibodies (MAb) directed against structural proteins of the lymphocytic choriomeningitis (LCM) virus, 3 were specific for the viral nucleoprotein (p63) and attached to the plasma membrane of infected cells, as disclosed by the indirect immunofluorescence procedure and complement-mediated cytolysis. We had previously demonstrated that a portion of the nucleoprotein (p63E) was part of the envelope of the intact virion (M. Bruns, W. Zeller, H. Rohdewohld, and F. Lehmann-Grube (1986) Virology 151, 77-85), and we now show that after external iodination of virions followed by limited proteolysis the label was attached to the smallest peptide thus obtained. If purified nucleocapsids were labeled with 125I, digested as before, and incubated with an anti-p63 MAb that has the ability to bind the surface of the infected cell, a similarly small peptide was precipitated; an antibody specific for p63 but not recognizing it on the cell surface precipitated the largest peptide and failed to bring down the small one. We conclude that the epitopes complementary to a few of our anti-p63 MAb are represented on both the virion and the surface of virus-infected cells.

Antibodies, Monoclonal↗
PubMed1988

Identification of Erwinia amylovora, the Fireblight Pathogen, by Colony Hybridization with DNA from Plasmid pEA29.

All strains of Erwinia amylovora characterized carry a medium-size plasmid of 29 kilobases (pEA29). We mapped this plasmid with various restriction enzymes, cloned the whole DNA into an Escherichia coli plasmid, and subcloned restriction fragments. These DNA species were used for identification of E. amylovora after handling of strains in the laboratory and also in field isolates. About 70 strains of E. amylovora and 24 strains from nine other species, mainly found in plant habitats, were checked in a colony hybridization test. Virulent and avirulent E. amylovora strains reacted positively, whereas the other species were negative. Apart from the hybridization assay, the positive strains were additionally tested for ooze production on rich agar with 5% sucrose and on immature-pear slices. Unspecific background hybridization of non-E. amylovora strains found for hybridization with the whole E. amylovora plasmid was almost eliminated when a 5-kilobase SalI fragment from pEA29 was used as a probe and when the washes after the hybridization procedure were done with high stringency. Under these conditions, E. amylovora could be readily identified from field isolates.

Journal Article↗
PubMed1986

Lymphocytic choriomeningitis virus. IX. Properties of the nucleocapsid.

Nucleocapsids (NC) of lymphocytic choriomeningitis (LCM) virus were obtained by treatment of purified infectious virus with detergent and salt at high concentrations, followed by gradient centrifugation. NC thus prepared contained 31 S RNA, 23 S RNA, and a protein with an apparent mol wt 63,000 and an isoelectric point pH 5.7 (p63), assumed to be the nucleoprotein. We had previously observed that the intact LCM virus contained two kinds of protein with mol wt 63,000 separable by their isoelectric points which were pH 5.7 and 7.7, respectively. We now found that the latter component was removed from the NC together with the glycoproteins, and labeling studies revealed that it was closely associated with the viral envelope. We have named the protein with a mol wt of 63,000 and an isoelectric point pH 7.7 p63E (E for envelope). By limited proteolysis both viral components of mol wt 63,000 could not be distinguished, indicating that they are basically identical. It appears that p63E is the phosphorylated form of p63.

Capsid↗
PubMed1985

The sensitizing capacity of Compositae plants. VI. Guinea pig sensitization experiments with ornamental plants and weeds using different methods.

Experimental studies in guinea pigs using ether extracts of 20 different species of the Compositae plant family were carried out with the open epicutaneous method (OET) and the guinea pig maximization test (GPMT). The results demonstrate that Cnicus benedictus (blessed thistle), Chrysanthemum leucanthemum (marguerite, ox-eye daisy) and Helianthus debilis (dwarf sunflower) are strong sensitizers while Helenium amarum (bitterweed), Gaillardia amblyodon (blanket flower), Artemisia ludoviciana (prairie sage), Ambrosia trifida (giant ragweed) and Solidago virgaurea (goldenrod) are medium sensitizers. Twelfe species revealed only a weak or no sensitizing capacity; among those were corn flower, wormwood, mugwort, coltsfoot and dandelion. Cross-reactivities were observed in a considerable number of the investigated plant species. The sensitizing power as well as the observed cross-reactions depend on the occurrence of sesquiterpene lactones which have an alpha-methylene group exocyclic to the lactone in common ("immunologic requisite"). As a practical consequence, patients suffering from allergic contact dermatitis due to Compositae species are strictly requested to avoid contact with the offending species and all related species to prevent recurrences of their skin lesions.

Allergens↗
PubMed1983

Age-dependent susceptibility of murine T lymphocytes to lymphocytic choriomeningitis virus.

In neonatal or congenital lymphocytic choriomeningitis (LCM) virus carrier mice, low numbers of T lymphocytes were always infected, but attempts to infect resting or stimulated T lymphocytes in previously uninfected adult mice have consistently failed. Only T cells in newborn mice were susceptible to LCM virus and their infection persisted when the animals grew older. Infectibility declined with increasing age of the mice. Initially, the majority was demonstrated among thymocytes, but later more splenic cells were infected. In contrast to neonatal carrier mice, in drug-induced carriers (in which persistent infection had been established later in life by immuno-suppression after infection) spleens and thymi contained initially no or a few infectious T lymphocytes; their numbers increased with the age of the mice but remained relatively low and erratic. We follow the hypothesis that LCM virus-specific immunological tolerance of carrier mice is due to age-dependent virus susceptibility of T lymphocytes and propose that murine T lymphocytes in general lack viral receptors for LCM virus, but that the few that carry LCM virus-specific immunological receptors bind the virus. If this occurs during an early stage of cellular development, infection results and functional inactivation is the consequence.

Age Factors↗