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Biomedical subjects

N P Burrows

Publications and source records attributed to N P Burrows.

At least 37 records · Page 2Linked to original sources
PubMed2000

Dispersal of radioisotope labelled solution following deep dermal injection in Ehlers-Danlos syndrome.

Ehlers-Danlos syndrome (EDS) is the commonest inherited disorder of connective tissue, affecting around 10 000 patients in the UK. Patients with EDS have reported that local anaesthetic is often ineffective. Patients with less severe skin laxity often have the most problems. We have postulated that this resistance to local anaesthetics is not due to the lax connective tissues as is often assumed. This study used radioactively labelled solution ((99m)Tc-pertechnetate) administered as a deep dermal injection in the forearm. The rate of dispersal of isotope was measured over 60 min and found to be identical between six patients with EDS and three controls. The effects of local anaesthetics are complex and depend on the individual chemical properties of the agent and a number of tissue factors. This study would suggest that the lack of effectiveness of local anaesthetic solutions is not due to rapid dispersal of solution. It is unlikely therefore that its lack of effect can be compensated for by simply increasing the amount used. The diagnosis of EDS should be considered in any patient who complains unexpectedly of pain during their procedure, particularly when the surgeon knows that an adequate volume of local anaesthetic has been used.

Administration, Cutaneous↗
PubMed1999

The molecular genetics of the Ehlers-Danlos syndrome.

The identification and investigation of many inherited disorders has an importance out of proportion to their frequency because of the insights they provide into physiological, pathological and molecular mechanisms. This is true of the heritable disorders of connective tissue which are a diverse group of conditions involving cutaneous, musculoskeletal, cardiovascular, ocular, gastrointestinal and pulmonary systems. The Ehlers-Danlos syndrome (EDS), which shows great clinical variability and genetic heterogeneity, is one example which has particular relevance to the dermatologist and is the focus of this review.

Collagen↗
PubMed1998

A point mutation in an intronic branch site results in aberrant splicing of COL5A1 and in Ehlers-Danlos syndrome type II in two British families.

Ehlers-Danlos syndrome (EDS) is a heterogeneous group of connective-tissue disorders characterized by skin fragility, joint laxity, and skeletal deformities. Type V collagen appears to have a causal role in EDS types I and II, which show phenotypic overlap and may sometimes be allelic. Type V collagen can exist as a heterotrimer, [alpha1(V)]2alpha2(V), and it both coassembles with and regulates type I collagen-fibril diameter. Using an intragenic COL5A1 polymorphism, we have demonstrated linkage, at zero recombination, to the same allele in two large British EDS type II families (LOD scores 4.1 and 4.3). Affected members from each family were heterozygous for a point mutation in intron 32 (IVS32:T-25G), causing the 45-bp exon 33 to be lost from the mRNA in approximately 60% of transcripts from the mutant gene. This mutation lies only 2 bp upstream of a highly conserved adenosine in the consensus branch-site sequence, which is required for lariat formation. Although both families shared the same marker allele, we have been unable to identify a common genealogy. This is the first description of a mutation at the lariat branch site, which plays a pivotal role in the splicing mechanism, in a collagen gene. Very probably, the resulting in-frame exon skip has a dominant-negative effect due to incorporation of the mutant proalpha chain into the triple-helical molecule. These findings further confirm the importance of type V collagen in the causation of EDS type II, and the novel collagen mutation indicates the importance of the lariat branch site in splicing.

Alternative Splicing↗
PubMed1998

A single base mutation in COL5A2 causes Ehlers-Danlos syndrome type II.

Ehlers-Danlos syndrome (EDS) is a heterogeneous group of connective tissue disorders. Recently mutations have been found in the genes for type V collagen in a small number of people with the most common forms of EDS, types I and II. Here we characterise a COL5A2 mutation in an EDS II family. Cultured dermal fibroblasts obtained from an affected subject synthesised abnormal type V collagen. Haplotype analysis excluded COL5A1 but was concordant with COL5A2 as the disease locus. The entire open reading frame of the COL5A2 cDNA was directly sequenced and a single base mutation detected. It substituted a glycine residue within the triple helical domain (G934R) of alpha2(V) collagen, typical of the dominant negative changes in other collagens, which cause various other inherited connective tissue disorders. All three affected family members possessed the single base change, which was absent in 50 normal chromosomes.

Base Sequence↗
PubMed1997

Systemic involvement in scleredema of Buschke associated with IgG-kappa paraproteinaemia.

Scleredema is a rare primary cutaneous mucinosis. Systemic involvement is uncommon and histological confirmation is often lacking. We report a case of a 60-year-old man with scleredema and evidence of mucin deposition on biopsies from multiple extracutaneous sites. The bone marrow, nerve, hepatic and salivary gland involvement seen on histology in our patient has not, to our knowledge, been previously reported in this condition.

Bone Marrow↗
PubMed1997

Genetic linkage to the collagen alpha 1 (V) gene (COL5A1) in two British Ehlers-Danlos syndrome families with variable type I and II phenotypes.

To investigate the role of COL5A1 as a candidate gene for Ehlers-Danlos syndrome (EDS), we have carried out linkage studies in two large British families with EDS type I/II and type II, respectively. Fourteen living, affected individuals were identified by family history, clinical examination and ultrastructural analysis. A polymorphic intragenic simple sequence repeat at the COL5A1 locus showed linkage to EDS without recombination to give a combined lod score of 5.7. We have previously reported linkage to COL5A1 in an EDS type I/II family which brings the total lod score to 9.8 at zero recombination. Taken together, these data implicate COL5A1 as an important cause of EDS and confirm that types I and II are allelic.

Collagen↗
PubMed1996

The gene encoding collagen alpha1(V)(COL5A1) is linked to mixed Ehlers-Danlos syndrome type I/II.

The Ehlers-Danlos syndrome (EDS) is a heterogeneous group of inherited connective tissue disorders in which cutaneous fragility and ligamentous laxity often combine with vascular, gastrointestinal, and skeletal deformities. There is considerable phenotypic overlap between the more common forms of EDS (types I and II), in which specific molecular defects have not yet been identified. Recently, genetic linkage has been demonstrated between the COL5A1 gene, which encodes the alphal chain of type V collagen, and EDS type II in a large British kindred. Using a polymorphic intragenic simple sequence repeat at the COL5A1 locus, we now demonstrate tight linkage to EDS type I/II in a three-generation family, giving a LOD score (log10 of the odds for linkage) of 4.07 at zero recombination. The variation in expression in this family suggests that EDS types I and II are allelic, and the linkage data support the hypothesis that mutation in COL5A1 can cause both phenotypes.

Aged↗
PubMed1996

ANCA associated with Behçet's disease.

Behçet's disease is a multisystem disorder affecting primarily mucocutaneous and ocular sites although the gastrointestinal, cardiovascular, central nervous and respiratory systems may also be involved. Hulusi Behçet, a Turkish dermatologist, first described Behçet's disease in 1937 and suggested a possible infectious aetiology. The pathogenesis of this condition still remains unclear although it is likely that infection acts as a trigger in genetically susceptible individuals. We report a patient with unusual cutaneous manifestations of Behçet's disease and antineutrophil cytoplasmic antibodies (ANCA) directed against the cytotoxic protein, bactericidal/permeability-increasing protein (BPI). This is the first report of Behçet's disease associated with this autoantibody.

Adult↗
PubMed1995

Antineutrophil cytoplasmic antibodies and their relevance to the dermatologist.

The term vasculitis embraces a heterogeneous group of conditions which may occur as primary phenomena or secondary to disorders such as rheumatoid arthritis or systemic lupus erythematosus. Classification of vasculitis is often difficult in the absence of identifiable aetiological factors or specific serological markers. However, the primary systemic vasculitides can be segregated morphologically, according to the size of blood vessels involved and the presence of granulomata (Table 1). Recently, the discovery of circulating antineutrophil cytoplasmic antibodies (ANCA) in many patients with these disorders, whose differing specificities substantiate the histological classification, has led to interest being focused on their relevance in the development of vasculitis. This paper reviews the historical aspects of the detection of ANCA, and the value of these antibodies in the diagnosis and management of the primary systemic vasculitides likely to be encountered by the dermatologist. The clinical features in patients with these vasculitides are also outlined.

Antibodies, Antineutrophil Cytoplasmic↗
PubMed1995

Treatment of extramammary Paget's disease by radiotherapy.

Extramammary Paget's disease (EMPD) is a rare cutaneous malignancy, which usually occurs in the elderly. Wide local excision is the recommended treatment, although this may not always be feasible. We report our experience of EMPD treated by radiotherapy in five patients. The radiotherapy was well tolerated in each case, and there were no signs of recurrence during follow-up (6 months-8 years). This study shows that radiotherapy is a useful alternative therapy for EMPD, and should be considered particularly in elderly patients who may not tolerate surgery.

Aged↗