PubMed Health⌕ Search

Biomedical subjects

G Keen

Publications and source records attributed to G Keen.

At least 19 recordsLinked to original sources
PubMed1998

Retinoic acid as a chemotactic molecule in neuronal development.

We describe the results of experiments on dissociated cultures of embryonic chick neural tissue which were designed to investigate further the role of all-trans-retinoic acid (tRA) on neurite outgrowth and, by inference, on the developing nervous system in vivo. We show that tRA increases both the number of neurites and the length of neurites extending from these chick neural tube cells at nM concentrations. Secondly, using the newly designed Dunn chamber in which stable gradients of compounds can be generated, we show that neurites respond to a gradient of tRA by growing up the gradient. These observations indicate a role for RA in vivo, not only in the initial outgrowth of neurites, but also in their guidance to the appropriate targets.

Animals↗
PubMed1997

The Genome Sequence DataBase version 1.0 (GSDB): from low pass sequences to complete genomes.

The Genome Sequence DataBase (GSDB) has completed its conversion to an improved relational database. The new database, GSDB 1.0, is fully operational and publicly available. Data contributions, including both original sequence submissions and community annotation, are being accomplished through the use of a graphical client-server interface tool, the GSDB Annotator, and via GIO (GSDB Input/Output) files. Data retrieval services are being provided through a new Web Query Tool and direct SQL. All methods of data contribution and data retrieval fully support the new data types that have been incorporated into GSDB, including discontiguous sequences, multiple sequence alignments, and community annotation.

Animals↗
PubMed1997

Apoptosis in cerebellar granule neurones: involvement of interleukin-1 beta converting enzyme-like proteases.

Proteases of the interleukin-1 beta converting enzyme (ICE) family have been implicated as mediators of apoptosis in several cell types. Here we report the ability of peptide inhibitors of ICE-like proteases to inhibit apoptosis of cultured cerebellar granule neurones caused by reduction of extracellular K+ levels and by the broad-spectrum protein kinase inhibitor staurosporine. Unlike apoptosis induced by K+ deprivation, staurosporine-induced neuronal death does not require new protein synthesis. The ICE-like protease inhibitor benzyloxycarbonyl-Val-Ala-Asp (O-methyl)fluoromethyl ketone (zVAD-fmk) was found to be extremely effective at preventing staurosporine-induced death of cerebellar granule neurones and yet was completely ineffective in preventing K+ deprivation-induced death. Staurosporine induced cleavage of the 116-kDa poly (ADP-ribose) polymerase enzyme, a substrate of ICE-like proteases, to the 85-kDa product, and this cleavage was also blocked by zVAD. By comparison, K+ deprivation led to the disappearance of the 116-kDa protein, with no detectable increase in level of the 85-kDa cleavage product. Taken together, these results imply the existence of divergent ICE-like protease pathways in a CNS model of neuronal apoptosis.

Amino Acid Chloromethyl Ketones↗
PubMed1996

The Genome Sequence DataBase (GSDB): meeting the challenge of genomic sequencing.

The genome sequence database (GSDB) is a complete, publicly available relational database of DNA sequences and annotation maintained by the National Center for Genome Resources (NCGR) under a Cooperative Agreement with the US Department of Energy (DOE). GSDB provides direct, client- server access to the database for data contributions, community annotation and SQL queries. The GSDB Annotator, a multi-platform graphic user interface, is freely available. Automatically updated relational replicates of GSDB are also freely available.

Amino Acid Sequence↗
PubMed1987

Spinal cord damage and operations for coarctation of the aorta: aetiology, practice, and prospects.

An inquiry was made into the clinical practice and paraplegia rate associated with operations for coarctation of the aorta conducted by surgeons in the United Kingdom and Ireland. Paraplegia occurred in 16 patients in a total of 5492 operations, an incidence of 0.3%, or once in 343 operations. The aetiology and measures that may be taken to avoid this complication are discussed. The medicolegal consequences need no emphasis and it is recommended that finger palpation alone as a method of assessing the adequacy of distal aortic pressure should be abandoned in favour of continuous electromanometric visual display of the aortic pressure in all patients. In the long term, serious consideration must be given to developing spinal cord monitoring using somatosensory evoked potentials.

Aortic Coarctation↗
PubMed1986

Onset of right-to-left shunting through a foramen ovale in a 70-year-old woman: successful surgical treatment.

A 70-year-old woman presented with disabling breathlessness. She was found to have severe arterial hypoxaemia due to isolated right-to-left shunting through a patent foramen ovale. In the absence of pulmonary hypertension or evidence of right ventricular dysfunction this is attributed to reduced right atrial compliance. The phasic nature of the shunt, which occurred only during atrial filling, supports this view. Surgical closure of the foramen abolished the hypoxaemia and her symptoms.

Aged↗
PubMed1982

Management of closed injuries of the innominate artery.

Two cases of closed traumatic rupture of the innominate artery are described. Both patients underwent surgical reconstruction, for which one patient was cooled to 15 degrees C on cardiopulmonary bypass. In the management of these rare and severe injuries, which almost invariably need surgical repair, protection of the cerebral circulation is vital; cerebral blood flow and function should be monitored during the operation, for which cardiopulmonary bypass, hypothermia, or local shunting should be available. Failure to recognise the features of these injuries lead to a high death rate, and aortography should be performed whenever there is clinical or radiological suspicion.

Adolescent↗
PubMed1978

Secondary leiomyosarcoma of the right ventricle. A surgical report.

A 48-year-old woman developed symptoms related to a tumour attached to the outflow tract of the right ventricle. Eleven years earlier she had undergone hysterectomy for leiomyosarcoma, and 4 years later a retroperitoneal mass was removed. One year later a further retroperitoneal mass was removed, and after a further 4 years a cutaneous tumour was removed from her back. Histologically these three tumours were identical with the leiomyosarcoma removed with the uterus at the primary operation. A confident preoperative diagnosis of recurrent leiomyosarcoma within the pericardium was made, and it was possible to remove this tumour using cardiopulmonary bypass with relief of symptoms. The patient remains well 15 months after surgery.

Female↗
PubMed1974

Chest injuries.

Explore the source record for details and available documents.

Accidents, Traffic↗