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Biomedical subjects

Keith Porter

Publications and source records attributed to Keith Porter.

10 recordsLinked to original sources
PubMed2006

High resolution array-CGH analysis of single cells.

Heterogeneity in the genome copy number of tissues is of particular importance in solid tumor biology. Furthermore, many clinical applications such as pre-implantation and non-invasive prenatal diagnosis would benefit from the ability to characterize individual single cells. As the amount of DNA from single cells is so small, several PCR protocols have been developed in an attempt to achieve unbiased amplification. Many of these approaches are suitable for subsequent cytogenetic analyses using conventional methodologies such as comparative genomic hybridization (CGH) to metaphase spreads. However, attempts to harness array-CGH for single-cell analysis to provide improved resolution have been disappointing. Here we describe a strategy that combines single-cell amplification using GenomePlex library technology (GenomePlex) Single Cell Whole Genome Amplification Kit, Sigma-Aldrich, UK) and detailed analysis of genomic copy number changes by high-resolution array-CGH. We show that single copy changes as small as 8.3 Mb in single cells are detected reliably with single cells derived from various tumor cell lines as well as patients presenting with trisomy 21 and Prader-Willi syndrome. Our results demonstrate the potential of this technology for studies of tumor biology and for clinical diagnostics.

Carcinoma, Renal Cell↗
PubMed2006

Accurate and reliable high-throughput detection of copy number variation in the human genome.

This study describes a new tool for accurate and reliable high-throughput detection of copy number variation in the human genome. We have constructed a large-insert clone DNA microarray covering the entire human genome in tiling path resolution that we have used to identify copy number variation in human populations. Crucial to this study has been the development of a robust array platform and analytic process for the automated identification of copy number variants (CNVs). The array consists of 26,574 clones covering 93.7% of euchromatic regions. Clones were selected primarily from the published "Golden Path," and mapping was confirmed by fingerprinting and BAC-end sequencing. Array performance was extensively tested by a series of validation assays. These included determining the hybridization characteristics of each individual clone on the array by chromosome-specific add-in experiments. Estimation of data reproducibility and false-positive/negative rates was carried out using self-self hybridizations, replicate experiments, and independent validations of CNVs. Based on these studies, we developed a variance-based automatic copy number detection analysis process (CNVfinder) and have demonstrated its robustness by comparison with the SW-ARRAY method.

Algorithms↗
PubMed2006

Microdeletion encompassing MAPT at chromosome 17q21.3 is associated with developmental delay and learning disability.

Recently, the application of array-based comparative genomic hybridization (array CGH) has improved rates of detection of chromosomal imbalances in individuals with mental retardation and dysmorphic features. Here, we describe three individuals with learning disability and a heterozygous deletion at chromosome 17q21.3, detected in each case by array CGH. FISH analysis demonstrated that the deletions occurred as de novo events in each individual and were between 500 kb and 650 kb in size. A recently described 900-kb inversion that suppresses recombination between ancestral H1 and H2 haplotypes encompasses the deletion. We show that, in each trio, the parent of origin of the deleted chromosome 17 carries at least one H2 chromosome. This region of 17q21.3 shows complex genomic architecture with well-described low-copy repeats (LCRs). The orientation of LCRs flanking the deleted segment in inversion heterozygotes is likely to facilitate the generation of this microdeletion by means of non-allelic homologous recombination.

Adolescent↗
PubMed2006

Acute exertional compartment syndrome of the superficial posterior compartment of the leg.

Acute exertional compartment syndrome of the superficial posterior compartment of the leg secondary to minor soft tissue injury is rare. This case series highlights the risk of misdiagnosis as deep venous thrombosis, followed by inadvertent anticoagulation. The delay in management did fortunately not lead to catastrophic consequences. Clinicians must not dismiss the possibility of an acute exertional compartment syndrome in the absence of direct trauma or after minor closed soft tissue injury.

Acute Disease↗
PubMed2004

Consensus on the pre-hospital approach to burns patient management.

Burns patients form a large group of trauma patients cared for by first-aiders, ambulance staff, nurses and doctors before reaching specialist care in hospital. Guidance for these important carers is often poor or confused and this engenders anxiety and detracts from optimal patient care. This paper outlines nine key steps in the initial management of burn patients in the pre-hospital environment based on current available evidence and a consensus of specialists all disciplines caring for burns patients. The basis of care should be that simple things should always be performed well.

Analgesia↗
PubMed2004

Consensus on the pre-hospital approach to burns patient management.

Burns patients form a large group of trauma patients cared for by first aiders, ambulance staff, nurses and doctors before reaching specialist care in hospital. Guidance for these important carers is often poor or confused and this engenders anxiety and detracts from optimal patient care. This paper outlines nine key steps in the initial management of burn patients in the pre-hospital environment based on current available evidence and a consensus of specialists from all disciplines caring for burns patients. The basis of care should be that simple things should always be performed well.

Analgesia↗
PubMed2003

How do you size a nasopharyngeal airway.

OBJECTIVE: To measure an appropriately sized nasopharyngeal airway, it is taught that the size is related to the patients little finger or nostril (anterior nares). This study has been designed to identify whether these comparisons are valid. METHOD: Direct comparison of the dimensions of ten subjects' little fingers and anterior nares with the internal anatomy of their nose as visualised on coronal MRI scans. RESULTS: Neither method correlated statistically with the nasal anatomy of that subject. CONCLUSIONS: The methods used traditionally to size a nasopharyngeal airway do not correlate with the airway anatomy and are unreliable. It is more appropriate to size the airway dependent upon the patient's size, sex and race.

Adult↗
PubMed2003

Endpoints for fluid resuscitation in hemorrhagic shock.

Vigorous intravenous fluid resuscitation has become widely accepted as the optimum management of hemorrhagic shock in trauma. There is now, however, sufficient evidence for this position to be reviewed. Hypotensive or delayed resuscitation has been postulated as a means by which the mortality associated with treatment can be reduced. It has been suggested that overresuscitation with intravenous fluids may worsen hemorrhage. This article discusses the possible adverse effects of "conventional" resuscitation and examines the evidence to support alternative treatment modalities.

Animals↗
PubMed2003

Crush injury and crush syndrome: a consensus statement.

Crush syndrome remains rare in European practice but is common in areas of civil disorder and where society has given way to civil war or natural disaster. Clinicians in the west are becoming increasingly involved in such situations and there is no reason to believe that the few instances due to conventional causes, such as an elderly person collapsing or road traffic accidents, will cease. Therefore, it is important that clinicians who deal rarely with crush syndrome have access to appropriate guidelines. This consensus report seeks to provide such advice.

Adult↗