The class I major histocompatibility antigen gene activated in a line of SV40-transformed mouse cells is H-2Dd, not Qa/Tla.

We have previously described several complementary DNA clones isolated because they correspond to messenger RNAs present at higher levels in the simian virus 40 (SV40)-transformed BALB/c 3T3 cell line SV3T3 Cl38 than in the normal, parental BALB/c 3T3 line. One of these clones, pAG64, hybridizes to RNAs which, while present in BALB/c 3T3 cells, are 10-20-fold more abundant in SV3T3 Cl38 and are found at high levels in a wide variety of transformed cell lines. Nucleotide sequence analysis showed that pAG64 encodes a class I antigen of the major histocompatibility complex.

Transcripts from an aberrantly re-arranged human T-cell receptor beta-chain gene.

A number of cDNA clones homologous to the human T-cell receptor beta-chain gene have been isolated from a library constructed from the human leukaemic cell line Jurkat. The nucleotide sequences of two of these clones demonstrate that Jurkat synthesizes an RNA, probably derived from an aberrantly rearranged C beta 1 gene, which cannot encode a functional beta-chain. This transcript contains a novel joining region and similar transcripts appear to be relatively abundant in several T-cell lines.

Isolation and characterization of an alphoid centromeric repeat family from the human Y chromosome.

A collection of human Y-derived cosmid clones was screened with a plasmid insert containing a member of the human X chromosome alphoid repeat family, DXZ1. Two positive cosmids were isolated and the repeats they contained were investigated by Southern blotting, in situ hybridization and sequence analysis. On hybridization to human genomic DNAs, the expected cross-hybridization characteristic of all alphoid sequences was seen and, in addition, a 5500 base EcoRI fragment was found to be characteristic of a Y-specific alphoid repeat.

The activation of cellular genes in transformed cells.

We have used differential cDNA cloning techniques to isolate a number of genes that are activated as a result of transformation by the DNA tumour virus Simian virus 40. From the nucleotide sequences of the cDNA clones we have been able to identify some of these genes. One of them derives from the major histocompatibility complex and contains a repetitive element that identifies a large number of RNAs present in pluripotential embryonic cells.

High efficiency gene transfer into mammalian cells.

We have generalized the protocol of gene transfer, greatly increasing the variety of cells that can be used as recipients of foreign genes. Our approach has been to use a transient assay system that allows rapid screening of expression of foreign DNA. When the initial steps of gene transfer have been optimized with the transient system, these defined conditions are used to yield efficient stable transformation.

Cosmid clones derived from both euchromatic and heterochromatic regions of the human Y chromosome.

Clones containing sequences derived from the human Y chromosome have been isolated from cosmid libraries of a human-mouse hybrid cell line. These libraries were constructed in the new expression vectors Homer V and Homer VI. The collection of cosmids isolated is enriched for unique sequence DNA and only a few of the cosmids contain the tandemly repeated sequences which constitute a major portion of the Y chromosome.

Regional localization of 3 Y-derived sequences on the human X and Y chromosomes.

The structure of the Y chromosome and the relationship between the human sex chromosomes have been studied using Y-derived sequences cloned in cosmids. Two probes recognize different unique sequences which map to the heterochromatic part of the long arm of the Y chromosome. A third sequence is shared by the long arm of the X chromosome and the euchromatic part of the Y chromosome.

An acute intervention trial: the research nurse coordinator's role.

A multicenter randomized clinical trial can offer exciting and challenging opportunities to the clinical coordinators and other health professionals who participate in the conduct of a clinical trial at the clinical units. This article will address an acute intervention trial, the Multicenter Investigation of the Limitation of Infarct Size, and demonstrate some of the important responsibilities of the clinical unit research nurse coordinators in the conduct and operation of this trial.

Cytoskeletal control of nuclear arrangement in Langhans multinucleate giant cells.

Examination of the role of the cytoskeleton in macrophage polykarya (multinucleate giant cells) has established that microfilaments and microtubules are interrelated and contractile cytoskeletal components with opposing actions; when critically maintained at equilibrium, they are responsible for maintenance of the highly organized cellular architecture characteristic of Langhans type syncytia. Disruption of the function of these structures by in vitro incubation with cytochalasin B and/or colchicine can result in reversion to a cytoarchitecture which is more typical of the 'foreign body' multinucleate giant cell. These observations strongly reinforce previous suggestions that Langhans multinucleate giant cells are special, more highly organized forms than are 'foreign body' multinucleate giant cells.

Simian virus 40 specific cytotoxic lymphocyte clones localize two distinct TSTA sites on cells synthesizing a 48 kD SV40 T antigen.

Simian virus 40 specific antigenic sites (TSTA) which react with SV40 specific cytotoxic lymphocytes (CTL) were localized on the surface of mouse embryo fibroblasts (H-2b) transformed with a recombinant plasmid which contain SV40 large T antigen coding DNA sequences (0.65-0.37 map units).

Activation of a Qa/Tla class I major histocompatibility antigen gene is a general feature of oncogenesis in the mouse.

A cDNA clone corresponding to a mRNA present at elevated levels in transformed fibroblasts encodes a Qa/Tla class I major histocompatibility complex (MHC) antigen. High levels of this mRNA are found in all tumour cells tested; the transcript can undergo alternative splicing; and a repetitive sequence within the transcription unit has the characteristics of a transposable element. The immunological implications of MHC gene activation in tumour cells are discussed.

Aspirin and recurrent hyphema after blunt ocular trauma.

Recurrent hyphema after traumatic blunt injury to the eye is associated with a more serious prognosis than that occurring from the initial trauma, resulting in a higher risk of glaucoma, corneal staining, surgical intervention, poor visual acuity, and enucleation. Risk factors associated with the development of recurrent bleeding are not well defined, but recent evidence suggests a high association with concurrent aspirin ingestion. Of 25 consecutive patients with hyphemas (20 males and five females, ranging in age from 2 to 53 years), 12 took aspirin after the initial trauma and seven had recurrent hyphemas.

Transcripts regulated during normal embryonic development and oncogenic transformation share a repetitive element.

We have previously isolated cDNA clones homologous to mRNAs present at elevated levels in transformed mouse fibroblasts. Clones of Set 1 contain a dispersed repetitive element present thousands of times in the mouse genome. This repeat identifies in mouse embryos a large number of transcripts that are quantitatively regulated during development.

Activation of mouse genes in transformed cells.

We have used molecular hybridization and cDNA cloning techniques to isolate mouse cellular genes activated in SV40-transformed cells and we show that many of the clones belong to one of four sets. We characterize the cytoplasmic transcripts and genomic sequences homologous to two of these sets. The Set 1 transcription unit(s) is activated in all SV40-transformed cell lines analyzed, and experiments with tsA-mutant-transformed lines show that activation appears to require functional large T-antigen.

The structure and expression of the preproenkephalin gene.

Enkephalins are pentapeptides with opioid activity which are found in a wide variety of tissues. Studies of enkephalin-containing peptides from the adrenal gland have established that the mature pentapeptides are derived by proteolytic processing of a precursor protein. We have shown that human adrenal medullary tumours contain mRNA which can be translated in vitro to yield a single major enkephalin precursor.

Functional analysis of a simian virus 40 super T-antigen.

The SV3T3 C120 line of simian virus 40-transformed mouse cells synthesizes no large T-antigen of molecular weight 94,000 but instead a super T-antigen of molecular weight 145,000. In the accompanying paper (Lovett et al., J.

Structure and synthesis of a simian virus 40 super T-antigen.

Mouse cells transformed by simian virus 40 often contain virus-coded tumor antigens distinct from those synthesized in productively infected permissive cells. The SV3T3 C120 cell line produces no large T-antigen of apparent molecular weight 94,000 but instead a super T-antigen of apparent molecular weight 145,000. We used recombinant DNA techniques to isolate the template for this super T-antigen and determined its structure by DNA sequencing.

Cloning of DNA fragments from the left end of the adenovirus type 12 genome: transformation by cloned early region 1.

The human adenovirus serotype 12 (Ad-12) EcoRI-C DNA fragment (0 to 16.5 map units) was cloned in the plasmid vector pAT153. This cloned Ad-12 EcoRI-C DNA fragment was subcloned generating recombinant plasmids which contained the Ad-12 SalI-C fragment (0 to 10.

The construction of cosmid libraries of eukaryotic DNA using the Homer series of vectors.

We have constructed and characterised a series of approved, disabled cosmid vectors which we call Homer cosmids and have examined the optimal conditions for the construction of libraries of eukaryotic DNA segments using these vectors. Analysis of these libraries shows that most of the sequences we have tested for are present at the expected frequency and that the libraries can be stably propagated. We have also directly tested the stability of cosmid clones carrying tandemly repeated inserts.