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W Roeder

Publications and source records attributed to W Roeder.

8 recordsLinked to original sources
PubMed1995

[Rupture of lateral ligaments of the ankle joint: MR imaging before and after functional therapy].

PURPOSE: Documentation via MRI of the healing of ruptured lateral collateral ankle ligaments after functional therapy. PATIENTS AND METHODS: 35 patients with ankle sprain were examined by MRI and stress radiographs, 13 were operated afterwards, 22 patients underwent a functional conservative therapy and were examined by MRI and stress radiographs and second time after three months. RESULTS: MRI reports were correct in 12 of 13 operated cases. After conservative therapy we did not find any disrupted ankle ligament. MRI showed intact ligaments thickened by scar. CONCLUSION: MRI is able to show injuries of the lateral collateral ankle ligaments and demonstrates the healing by scar after conservative therapy.

Adolescent↗
PubMed1988

Murine B lymphoma cell lines release functionally active interleukin 2 after stimulation with Staphylococcus aureus.

In this study it is shown that an IL-2-like functional lymphokine activity derived from the murine B cell lines 2PK-3 and L10A2J after stimulation with Staphylococcus aureus can be blocked with anti-IL-2 mAb such as 9B11, DMS-1, and S4B6. Experiments demonstrate that the stimulation of the IL-2-sensitive cell line CTLL-2 by the IL-2-like functional activity derived from murine B cell tumors can also be blocked with the anti-IL-2R mAb PC61. Additionally, in RNA-RNA hybridization experiments with radiolabeled SP6-derived ssRNA probes developed from murine IL-2 genomic DNA sequences and specific for IL-2 mRNA, quantitatively significant amounts of IL-2-specific mRNA in both 2PK-3 and L10A2J are shown subsequent to stimulating the cells with S. aureus. These results suggest the murine B cell tumor lines 2PK-3 and L10A2J synthesize and release IL-2 after stimulation with selected polyclonal activators such as S. aureus.

Animals↗
PubMed1981

The role of DNA rearrangement and alternative RNA processing in the expression of immunoglobulin delta genes.

We have established the exon-intron structure of the gene coding for the constant (C) region of the mouse immunoglobulin delta heavy chain, using DNA clones isolated from BALB/c embryos and the delta mRNA extracted from two delta-producing hybridomas, B1-8. delta 1 and GCL2.8. At least three types of C delta gene structures are identified. A 2.7 kb delta mRNA reveals six exons. This delta mRNA may code for a membrane-bound delta chain. A second delta mRNA of 1.8 kb shares the first (5' side relative to direction of transcription) three exons with the 2.7 kb delta mRNA and in addition contains a fourth exon unique to this mRNA species. This delta mRNA most likely codes for a secreted delta chain. A third delta mRNA, also of 1.8 kb, shares the first four exons and a part of the fifth exon with the 2.7 kb mRNA. Its function, if any, remains unclear. We investigated the question of how a lymphocyte can produce the mu and delta heavy chains simultaneously, using the hybridoma GCL 2.8, which makes both IgM and IgD. Results of Southern gel blot analysis and gene cloning experiments indicate that this cell utilizes the same rearranged VH gene for the synthesis of the mu and delta chains, and yet maintains the embryonic configuration for the C mu and C delta genes and for the intervening region. Based on these results, we conclude that the VH sequence is spliced alternatively to the C mu or C delta sequence during processing of the primary RNA transcript. An alternative mechanism for the expression of the delta gene is found in hybridoma B1-8. delta 1, which actively secretes delta chains and synthesizes no mu chain. This mechanism involves deletion of the C mu gene, which brings the complete VH gene closer to the C delta gene.

Animals↗
PubMed1981

Linkage of the four gamma subclass heavy chain genes.

The genes for the heavy-chain constant regions of the four gamma subclass immunoglobulins were identified in a set of overlapping mouse DNA fragments representing about 100 kilobase pairs (kb) of the mouse genome that was cloned from bacteriophage lambda libraries of BALB/c mouse embryo DNA. R-loop mapping studies show that the genes are located 5'-C gamma 3-34 kb-C gamma 1-21 kb-C gamma 2b-15 kb-C gamma 2a-3' and lie in the same transcriptional orientation. Two DNA segments, one of 19 kb and another of 15 kb, that surround the C gamma 2b and C gamma 2a genes, respectively, show considerable homology and implicate a tandem duplication mechanism in the evolution of this gene cluster.

Animals↗
PubMed1980

Two types of somatic recombination are necessary for the generation of complete immunoglobulin heavy-chain genes.

At least two types of somatic recombination are necessary for the generation of a complete immunoglobulin gamma 2b gene from germ-line DNA sequences. The first type of recombination consists of the assembly of three separate DNA segments, each encoding a different part of the variable region. The second type of recombination replaces the exons coding for the constant region of the mu chain with those coding for the same region of the gamma 2b chain. The DNA sequencing studies suggest that the two types of recombination operate by different mechanisms.

Animals↗
PubMed1980

Exon shuffling generates an immunoglobulin heavy chain gene.

From endonuclease EcoRI partial libraries of DNAs from mouse embryo and MOPC 141, a gamma 2b-producing myeloma, clones were isolated by using a DNA fragment carrying the gamma 2b constant (C) region gene as a hybridization probe. One clone from MOPC 141 contained a heavy chain variable (V) gene and the C gamma 2b gene, as demonstrated by R-loop mapping. The V gene and C gene in this clone were separated by a 3.9-kilobase intron. The characterization of this clone as well as the embryonic clones suggest that at least two recombination events occurred to create the gamma 2b gene in MOPC 141. One of the events is analogous to the V-J joining previously demonstrated in the light chain genes, which brings the major part of the V gene next to a short coding sequence (J). The other event we refer to as "C mu-C gamma 2b switch recombination" because a portion of the intron between the V gene and C gene of the rearranged gamma 2b gene is derived from the 5' flanking sequence of the embryonic C mu gene. A model suggesting how the phenomenon of switch seen in lymphocytes may occur is presented.

Animals↗
PubMed1979

Cloning the trpR gene.

In Escherichia coli, the structural gene for purine nucleoside phosphorylase, deoD, is subject to insertional inactivation by prophage lambda. From one such secondary site lambda lysogen, strain SP265, one may isolate deletions that remove all or part of the trpR gene and other genes in the deo-thr sector of the E. coli chromosome. Specialized transducing phages harboring serB+ and trpR+ were liberated following induction of SP265. All such phages were N-defective, bio-type pseudolysogens whose DNA persisted in the form of plasmids. A collection of transducing phages, differing in their complement of bacterial DNA, was used to locate cleavage sites for BamHI, SalI, and PvuI within the deoD-trpR region of the E. coli genome. The trpR gene lies within a specific 950 base pair BamHI-PvuI segment. A 1250 base pair BamHI fragment carrying a functional trpR gene was cloned into the amplifiable plasmid pBR322. A single SalI site in this fragment was shown to lie within the TrpR gene. In two situations where increased gene dosage might generate elevated amounts of Trp repressor (N-defective trpR+ pseudolysogens and strains harboring pBR322 trpR+ plasmids) neither tryptophan auxotrophy, enhanced sensitivity to DL-5-methyl-tryptophan, nor super repression of the tryptophan biosynthetic enzymes was observed.

Bacteriophage lambda↗