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Biomedical subjects

R A Clarke

Publications and source records attributed to R A Clarke.

At least 19 recordsLinked to original sources
PubMed1997

Production and verification of an anti-ovine IgE monoclonal antibody.

Recombinant mouse/sheep IgE was used in the production of an anti-IgE monoclonal using conventional hybridoma techniques. The specificity of hybridomas secreting anti sheep IgE monoclonal antibodies was verified using a number of assays including competitive ELISAs, ability to induce mediator release from mast cells, and IgE binding using western blotting. Immunohistochemical staining demonstrated the binding of putative anti-IgE monoclonals to the sheep mast cell surface. The isotype of the antibody was IgG1:K.

Animals↗
PubMed1996

Patterned expression in familial Klippel-Feil syndrome.

Klippel-Feil syndrome (KFS) is characterised by congenital fusion of vertebrae within the rostral spine. The first KFS gene (SGM1) locus identified on chromosome 8 segregates with vertebral fusions and associated vocal impairment within the KF2-01 family (Clarke et al., '94, '95). Here, we describe the unique pattern of variable phenotypic expression within the KF2-01 family. The pattern of anomalies revealed a cumulative, rostrocaudal graded sequence of skipped vertebral fusions. This fusion pattern presents striking similarities with the mutant phenotype and gene expression profile of the Drosophila segment polarity gene engrailed.

Adolescent↗
PubMed1995

Midwives, their employers and the UKCC: an eternally unethical triangle.

The majority of midwives in the UK are employed within the NHS. They are legally bound to fulfil their contractual obligations to their employers. At the same time they are professionally mandated to interpret and act on the UKCC's Code of professional conduct. Midwives have always maintained that they are autonomous practitioners, and the Code is written in a way that endorses this belief. Underlying the Code is the assumption that midwives have moral and professional freedom to act on its imperatives. However, midwives' claim to autonomy is flawed, and therefore the Code's claim to be a source of empowerment is also flawed. Underlying the difficulties is a conflict derived from the imposition of a deontologically-based professional Code on to a workforce that is constrained within and employed by the utilitarian-based NHS.

Employment↗
PubMed1995

Familial Klippel-Feil syndrome and paracentric inversion inv(8)(q22.2q23.3).

Klippel-Feil Syndrome (KFS) is characterized by congenital vertebral fusion believed to result from faulty segmentation along the embryo's developing axis. KFS appears to be a heterogeneous disease often associated with craniofacial malformation. Here we provide the first evidence of a familial KFS gene locus on 8q, where an inv(8)(q22.2q23.3) has been found segregating with congenital vertebral fusion. The four-generation KF2-01 family present with dominant form of the KFS where the sequence of vertebral fusion was confined to the cervical spine (always including the C2-3 fusion and reduced expression of the C4-5 and C6-7 fusions) in association with malformation of laryngeal cartilages and mild-to-severe vocal impairment.

Chromosome Inversion↗
PubMed1994

Cellular inflammatory responses in skin of sheep selected for resistance or susceptibility to fleece rot and fly strike.

Leucocyte populations were examined in normal and inflamed skin of sheep bred for resistance (R) or susceptibility (S) to bacterial fleece rot and the common sequela, body strike caused by the dipteran parasite Lucilia cuprina. No differences between R and S lines were found in numbers of neutrophils accumulating in acute inflammatory lesions induced by activated complement, leukotriene B4, interleukin (IL)-1 beta, tumour necrosis factor-alpha, IL-8 or endotoxin from Pseudomonas aeruginosa. T19+ (alpha gamma delta T cell subset) lymphocytes and eosinophils were more prevalent in skin of sheep from the S line whereas IgE+ cells were more prevalent in skin of sheep from the R line. In an unrelated population of sheep, animals with low fleece rot scores had more intense neutrophil migration into inflammatory lesions induced by all the mediators examined than did animals with high fleece rot scores. IgE+ cells were more prevalent in animals with low fleece rot scores, although in contrast to R and S lines, T19+ cells tended to be elevated in this group of animals. The results suggest that defence mechanisms associated with IgE+ cells in skin may play an important role in resistance to fleece rot and fly strike.

Animals↗
PubMed1994

Klippel-Feil syndrome associated with malformed larynx. Case report.

We report a case of a 45-year-old man with Klippel-Feil syndrome with fusion of the C2-3 and C4-5 cervical vertebrae and severe voice impairment associated with malformation of the laryngeal cartilages. The condition was also complicated by bilateral inflexibility of the arms and legs and external malformation of the ears. This case broadens the spectrum of anomalies, of branchial arch derivation, now identified in association with Klippel-Feil syndrome. We discuss the possibility that perturbation of segmentation, distinct from somitogenesis, may be linked to Klippel-Feil syndrome-associated craniofacial abnormalities.

Humans↗
PubMed1994

Expression of a recombinant sheep IgE gene.

An ovine cosmid library was screened with a bovine C epsilon gene probe. IgE and IgA constant region genes (C epsilon and C alpha, respectively) were isolated within a single 26 kb cosmid insert. The C epsilon gene was cloned into an expression vector which contained the rearranged VDJ genomic segment encoding an anti-(4-hydroxy-3-iodo-5-nitrophenyl) acetic acid (anti-NIP) VH chain. This chimeric construct was transfected into murine hybridoma cells producing L chain with anti-NIP antibody specificity and stable transfectomas secreting chimeric ovine-murine IgE anti-NIP antibodies were obtained. Chimeric antibody, affinity purified from culture supernatants of transfected cells on a NIP-sepharose column, was characterised by SDS-PAGE and shown to contain H and L chains of expected size. These experiments demonstrated the power of advanced molecular genetic techniques to generate immunological reagents against low abundance immunoglobulin isotypes thus facilitating monoclonal antibody production for further immunological studies.

Animals↗
PubMed1994

Adenosine triphosphate bioluminescence as a method to determine microbial levels in scald and chill tanks at a poultry abattoir.

According to Hazard Analysis of Critical Control Points (HACCP) programs developed for the poultry industry, poultry processing waters should be actively monitored to minimize cross-contamination between chicken carcasses. In order to monitor HACCP programs, a test is required that provides results on a real time basis. A modified adenosine triphosphate (ATP) bioluminescence test has been developed that can assess microbial levels in poultry processing waters within 15 min. A study was conducted to determine the effectiveness of this test for examining scald, prechill, and chill tank waters. The results showed that the modified ATP bioluminescence method gave results comparable to plate counts. The microbial levels were dependent on the tank and the time of sampling. The highest microbial levels were detected in the scald tank. In all three tanks, the microbial levels increased over time during the day.

Abattoirs↗
PubMed1993

Organisation of the ovine immunoglobulin C epsilon gene locus: evidence for a deletion 5' of the gene.

A cosmid clone containing the ovine and C epsilon and C alpha immunoglobulin heavy chain genes was isolated and characterised. Restriction mapping and sequence analysis showed a high degree of similarity between the bovine and ovine C epsilon loci. Restriction fragment length polymorphism (RFLP) analysis of sheep genomic DNA revealed Mendelian inheritance of polymorphisms with identical variation in allele size for various restriction enzymes. This identical variation suggested that a deletion of approximately 100 bp existed at the 5' end of the smaller alleles.

Alleles↗