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Biomedical subjects

J Hurst

Publications and source records attributed to J Hurst.

At least 55 records · Page 3Linked to original sources
PubMed1991

Germinomas and teratoid siphon anomalies in softshell clams, Mya arenaria, environmentally exposed to herbicides.

Seminomas and dysgerminomas are epizootic in softshell clams, Mya arenaria, from three Maine estuaries contaminated with herbicides. The first epizootic was discovered in 22% of clams collected as Searsport near Long Cove Brook and three culverts that conveyed heating oil and jet fuel spilled from a tank farm in 1971. Data from subsequent epizootiological studies and a series of long-term experimental exposures of softshell clams to no. 2 fuel oil, JP-4, and JP-5 jet fuel at the U.S. EPA, Environmental Research Laboratory in Narragansett, Rhode Island, and in the field did not support an etiology by these petroleum products. In the two recent epizootics reported here, the germinomas have been observed in 3% of the softshell clams collected from Roque Bluffs near Machiasport and from 35% of softshell clams collected from Dennysville. Mya collected at Dennysville had pericardial mesotheliomas and teratoid siphon anomalies in addition to gonadal neoplasms. Estuaries at Dennysville had been contaminated by herbicides in a 1979 accidental spray overdrift during aerial application of Tordon 101 to adjacent forests. Further investigation determined widespread use of the herbicides Tordon 101, 2,4-D,2,4,5-T, and other agrochemicals in an extensive forestry and blueberry industry in both the Roque Bluffs and the Dennysville areas. Herbicide applications at Searsport were confirmed for railroad property bordering Long Cove estuary and for Long Cove Brook adjacent to the estuary where a highway department reportedly cleans its spray equipment. Herbicide contamination is the only common denominator identified at all three sites where Mya have been found with gonadal neoplasms.(ABSTRACT TRUNCATED AT 250 WORDS)

Abnormalities, Drug-Induced↗
PubMed1990

DNaseI hypersensitive sites 1, 2 and 3 of the human beta-globin dominant control region direct position-independent expression.

The human beta-globin dominant control region (DCR) which flanks the multigene beta-globin locus directs high level, site of integration independent, copy number dependent expression on a linked human beta-globin gene in transgenic mice and stably transfected mouse erythroleukemia (MEL) cells. We have assayed each of the individual DNaseI hypersensitive regions present in the full 15kb DCR for position independence and copy number dependence of a linked beta-globin gene in transgenic mice. The results show that at least three of the individual DNaseI hypersensitive site regions (sites 1, 2 and 3), though expressing at lower levels than the full DCR, are capable of position independent, copy number dependent expression. Site 2 alone directs the highest level of expression of the single site constructs, producing nearly 70% of the level of the full DCR. Sites 1 and 3 each provide 30% of the full activity. Deletion of either site 2 or 3 from the complete set significantly reduces the level of expression, but does not effect position independence or copy number dependence. This demonstrates that sites 2 and 3 are required for full expression and suggests that all the sites are required for the full expression of even a single gene from this multigene locus.

Animals↗
PubMed1990

Two brothers with heart defects and limb shortening: case reports and review.

Two male Arab sibs are reported with congenital heart disease and skeletal malformations. Other published case reports sharing some features in common with these brothers are considered. However, clinical and radiological features in these boys are distinct enough to represent a new cardioskeletal syndrome.

Abnormalities, Multiple↗
PubMed1988

Cost of achieving a balance in the anaesthetic department of a district general hospital.

In Achieving a Balance the Department of Health published requirements for medical staffing in hospitals. To review the effect that these would be likely to have a study was undertaken in the anaesthetic department of a district general hospital. The results were then validated with staffing levels in a new district general hospital with only one tier of junior staff. It was found that over the next 10 years a massive expansion in the numbers of consultants would be needed at a cost of 108,000 pounds in salaries and employer's contributions alone.

Anesthesia Department, Hospital↗
PubMed1987

The human beta-globin gene contains a downstream developmental specific enhancer.

The human beta-globin gene is part of a multigene family and is expressed specifically in adult human erythroid tissue (for review, 1). When the human beta-globin is introduced into fertilized mouse eggs, it is first activated in foetal liver and remains expressed in adult erythroid tissues. It therefore mimicks the pattern of expression of its murine counterpart. It has previously been shown in tissue culture and transgenic mice that sequences downstream from the beta-globin promoter are involved in this regulation. We now show that at least part of these sequences are located 0.5-1.2kb downstream from the poly A addition site and constitute a transcriptional enhancer element that is erythroid and developmental specific.

Animals↗
PubMed1987

The regulation of expression of human beta-globin genes.

We have analyzed the regulation of expression of the human beta-globin gene by DNA mediated gene transfer in MEL cells and microinjection in fertilized mouse eggs. The results show that the beta-globin gene contains two regulatory elements: one element in the promoter, that is required for full transcriptional activity and, secondly, a tissue and developmental specific enhancer 3' to the gene.

Animals↗
PubMed1986

Gamma delta beta-thalassaemias 1 and 2 are the result of a 100 kbp deletion in the human beta-globin cluster.

The DNA spanning two large deletions in the human beta-globin gene cluster (gamma beta-thalassaemia 1 and 2) has been cloned by cosmid cloning and chromosomal walking. The entire region was mapped and analyzed for the presence of repetitive sequences. The results show that the affected loci have lost almost 100 kb of DNA in a deletion event not involving homologous or repetitive sequences.

Chromosome Deletion↗
PubMed1986

Regulated expression of human A gamma-, beta-, and hybrid gamma beta-globin genes in transgenic mice: manipulation of the developmental expression patterns.

We have introduced the human fetal gamma- and adult beta-globin genes into the germ line of mice. Analysis of the resulting transgenic mice shows that the human gamma-globin gene is expressed like an embryonic mouse globin gene; the human beta-globin gene is expressed (as previously shown) like an adult mouse globin gene. These results imply that the regulatory signals for tissue- and developmental stage-specific expression of the globin genes have been conserved between man and mouse but that the timing of the signals has changed. Because the two genes are expressed differently, we introduced a hybrid gamma beta-globin gene construct. The combination of the regulatory sequences resulted in the expression of the hybrid gene at all stages in all the murine erythroid tissues.

Animals↗
PubMed1986

Cloning and developmental expression of the murine neurofilament gene family.

DNA clones encoding the 3 mouse neurofilament (NF) genes have been isolated by cross-hybridization with a previously described NF-L cDNA probe from the rat. Screening of a lambda gt10 cDNA library prepared from mouse brain RNA led to the cloning of an NF-L cDNA of 2.0 kb that spans the entire coding region of 541 amino acids and of an NF-M cDNA that covers 219 amino acids from the internal alpha-helical region and the carboxy-terminal domains of the protein. These cDNA clones were used as probes to screen mouse genomic libraries, and cosmid clones containing both NF-L and NF-M sequences were isolated as well as overlapping cosmids containing the NF-H gene. This strongly suggests that the 3 neurofilament genes are organised in a cluster and derived by gene duplication of a common ancestral gene. RNA blot analyses using specific DNA probes for each of the genes indicate that NF mRNAs are differentially expressed during brain development. The NF-L and NF-M mRNAs are detected early in the embryonal brain, with a progressive increase in their levels during development, while the NF-H mRNA is barely detectable at embryonal stages and accumulates later in the postnatal brain.

Animals↗
PubMed1985

Chromosomal localization of the human Thy-1 gene.

We have isolated the gene coding for human Thy-1. Introduction of this gene into HeLa cells by DNA-mediated transfer results in the expression of Thy-1 antigen on the cell surface. Chromosomal mapping of the Thy-1 gene by hybridization to metaphase chromosomes and Southern blots of DNA from hybrid cells indicate that the Thy-1 gene is located on the long arm of chromosome 11.

Antigens, Surface↗