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Biomedical subjects

S Snelling

Publications and source records attributed to S Snelling.

6 recordsLinked to original sources

Genetic association analysis of LRCH1 as an osteoarthritis susceptibility locus.

OBJECTIVE: A genetic association with knee osteoarthritis (OA) of a single nucleotide polymorphism (SNP) in intron 1 of the LRCH1 gene was recently reported in a UK Caucasian case-control sample and confirmed in a Newfoundland Caucasian sample. Our objective was to assess whether the SNP was associated with OA in our large UK Caucasian sample. METHODS: The SNP was genotyped in 1521 cases that had undergone elective joint replacement of the hip (1098 cases), of the knee (340 cases) or of the hip and knee (83 cases) due to end-stage primary OA. The SNP was also genotyped in 736 controls of similar ages in the cases. RESULTS: There was no significant difference (all P-values >0.05) in genotype or allele frequencies between our cases and our controls. There was also no significant difference when the cases were stratified by sex, by joint replaced or by sex combined with joint replaced. CONCLUSION: Our data on 2257 individuals implies that the LRCH1 intron 1 SNP is not a risk factor for OA aetiology of the knee or of the hip in our UK Caucasian sample.

Aged↗

Allelic expression analysis suggests that cis-acting polymorphism of FRZB expression does not contribute to osteoarthritis susceptibility.

OBJECTIVE: The FRZB gene codes for secreted frizzled-related protein 3 (sFRP3), a soluble antagonist of wnt signalling that is required for maintaining cartilage integrity. Two common single nucleotide polymorphisms (SNPs) that code for the substitution of conserved arginine residues have previously been identified in FRZB and found to be associated with osteoarthritis (OA). Functional studies revealed that the arginine substitutions lead to a loss-of-function of sFRP3 activity. We set out to assess whether cis-acting polymorphism in the regulation of FRZB expression exists, as this may be an additional mechanism through which sFRP3 activity could be modulated. METHODS: RNA was extracted from the articular cartilage chondrocytes of 25 individuals who had undergone joint replacement for OA and who were heterozygous for one of the two FRZB SNPs. Allelic output was measured by single base extension in to the SNPs and deviations from the expected 1:1 pattern were assessed using the Mann-Whitney U test. RESULTS: Differential allelic expression was observed in six of the 25 individuals. However, the average fold difference in allelic expression in the six was only 1.19. CONCLUSIONS: The presence of a small degree of differential allelic expression in a low proportion (24%) of the individuals studied suggests that polymorphism in FRZB cis-acting regulatory elements can be discounted as a major factor that could influence the development of OA.

Aged↗

The influence of tumour microenvironmental factors on the efficacy of cisplatin and novel platinum(IV) complexes.

The chemotherapeutic drug cisplatin is an important treatment for many types of solid tumours, in particular non-small cell lung cancer (NSCLC). Platinum(IV) complexes offer several advantages to cisplatin due to their requirement for reduction to the active platinum(II) form to elicit cytotoxicity. This should minimise non-specific effects and facilitate higher amounts of the active complexes reaching the target DNA. Hypoxia and a quiescent cell population are features of the tumour microenvironment known to lead to resistance to many chemotherapeutic agents. It is unclear how these microenvironmental factors will impact on the efficacy of novel platinum(IV) complexes. Consequently, the cytotoxicities of several platinum drugs were determined in monolayer and tumour spheroid cultures derived from NSCLC lines. Platinum(IV) reduction potential correlated well with cytotoxicity. The complex containing a chloro axial ligand demonstrated the greatest potency and the drug with the hydroxy ligand was the least effective. Although drug cytotoxicity was not enhanced under hypoxic conditions, both cisplatin and the platinum(IV) complexes retained full potency. In addition, all of the platinum drugs retained the ability to evoke apoptosis in quiescent cells. In summary, unlike many anticancer drugs, the platinum(IV) complexes retain cytotoxic potency under resistance-inducing tumour microenvironmental conditions and warrant further investigation as more selective alternatives to current platinum-based therapy for the treatment of solid tumours.

Antineoplastic Agents↗

Ceftazidime or gentamicin plus benzylpenicillin in neonates less than forty-eight hours old.

A clinical trial was conducted to assess the value of ceftazidime as a first-line antibiotic in a neonatal intensive care unit. Fifty-five infants less than 48 h old with suspected sepsis were randomly treated with ceftazidime or penicillin and gentamicin. A full septic screen was performed in all infants before treatment. Treatment was stopped after 48 h if cultures were sterile. A further 22 infants more than 48 h old, with clinical evidence of sepsis, were treated with ceftazidime in an open trial. Ceftazidime proved effective against all but two of the septicaemias. A group D beta-haemolytic streptococcus and a coagulase-negative staphylococcus proved resistant, but were also resistant to penicillin and gentamicin. No adverse response to ceftazidime was noted, and the incidence of later candidiasis was similar to that after other broad-spectrum antibiotic combinations. The avoidance of gentamicin assay in the ceftazidime group was an advantage in this age group.

Bacterial Infections↗