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R Baer

Publications and source records attributed to R Baer.

116 records · Page 7Linked to original sources
PubMedDate not supplied

A novel solid-phase approach to 2,4-diaminothiazoles.

A novel solid-phase synthesis of a 2,4-diaminothiazole library starting from a polymer-bound thiouronium salt is described. The synthetic strategy involves formation of polymer-bound thioureido-thiourea intermediates [5] which by treatment with alpha-bromo-ketones [6] undergoes S-alkylation, followed by a base-catalyzed intramolecular-ring closure/cleavage to give 2,4-diaminothiazoles [8]. This strategy tolerates a wide range of functionality and protecting groups. The novel feature of our method is a polymer-supported auto-scavenging strategy (PSAS), which provides a clean, high-yielding, and traceless synthesis to 2,4-diaminothiazoles.

Alkylation↗
PubMedDate not supplied

Altered nucleotide sequences of a translocated c-myc gene in Burkitt lymphoma.

The nucleotide sequence of a translocated c-myc gene in a Burkitt lymphoma reveals multiple base changes in the coding region. Twenty-five base changes, generating 16 codon alterations, were found in the first coding exon; no changes occur in the second coding exon. These changes are probably the result of somatic mutations that occurred during and after translocation, and may contribute to oncogenesis by allowing synthesis of an altered c-myc gene product.

Amino Acid Sequence↗
PubMedDate not supplied

Transcription enhancer identified near the human C mu immunoglobulin heavy chain gene is unavailable to the translocated c-myc gene in a Burkitt lymphoma.

In Burkitt lymphoma the c-myc gene, the cellular homologue of the viral oncogene v-myc, has been implicated in the aetiology of this human B-cell malignancy. Burkitt lymphoma cells possess specific chromosomal rearrangements involving the region proximal to the c-myc gene and one of the three human immunoglobulin loci. The nature of the effect exerted by the immunoglobulin loci on the translocated c-myc gene is controversial: whereas some reports have suggested c-myc transcription is elevated in Burkitt lymphoma cells, others have suggested the level of transcription is unaffected by the translation. Recently, transcription enhancer elements have been identified in the intron between the JH and C mu segments of the heavy-chain immunoglobulin gene in mice. If similar enhancers exist in humans they may lead to increased transcription of the translocated c-myc gene and thus contribute to oncogenesis in Burkitt lymphoma. We report here the identification of an enhancer element adjacent to the human C mu gene on normal chromosome 14, but this enhancer does not remain on the abnormal chromosome 14 to which the c-myc gene has been translocated in the Burkitt lymphoma cell line Raji. This element is, therefore, not available for control of the translocated c-myc gene in this case.

Base Sequence↗
PubMedDate not supplied

Effect of somatic mutation within translocated c-myc genes in Burkitt's lymphoma.

Our previous studies of a translocated c-myc gene in the Raji Burkitt's lymphoma cell showed somatic mutations in exons 1 and 2. We have extended these observations to two other translocated c-myc genes and find a common occurrence of mutation in the noncoding exon 1. We also found that in Raji cells, unlike other Burkitt's lymphoma cell lines, the normal allele of the c-myc gene is transcribed as well as the translocated gene. These results support a model in which c-myc oncogene activation in Burkitt's lymphoma occurs by disruption of a normal transcriptional control mechanism in which the c-myc protein is itself involved.

Base Sequence↗
PubMedDate not supplied

DNA sequence and expression of the B95-8 Epstein-Barr virus genome.

The complete (172,282 base pairs) nucleotide sequence of the B95-8 strain of Epstein-Barr virus has been established using the dideoxynucleotide/M13 sequencing procedure. Many RNA polymerase II promoters have been mapped and the mRNAs from these promoters have been assigned to the latent or early/late productive virus cycles. Likely protein-coding regions have been identified and three of these have been shown to encode a ribonucleotide reductase, a DNA polymerase and two surface glycoproteins.

Base Sequence↗