Conservation of receptor antagonist anti-tumor activity by epidermal growth factor receptor antibody expressed in transgenic corn seed

Recombinant protein production in plants such as corn is a promising means to generate high product yields at low comparable production cost. The anti-EGFR monoclonal antibody C225, cetuximab, is a well-characterized receptor antagonist antibody recently approved for the treatment of refractory colorectal cancer. We initiated a study to test and compare the functional activity of glycosylated and aglycosylated C225 produced in stable transgenic corn seed. Both corn antibodies were shown to be functionally indistinguishable from mammalian-derived C225 in demonstrating high-affinity binding to the EGF receptor, blocking of ligand-dependent signaling, and inhibiting cell proliferation. In addition, consistent with cetuximab, both corn antibodies possessed strong anti-tumor activity in vivo. Acute dose primate pharmacokinetic studies, however, revealed a marked increase in clearance for the glycosylated corn antibody, while the aglycosylated antibody possessed in vivo kinetics similar to cetuximab. This experimentation established that corn-derived receptor blocking monoclonal antibodies possess comparable efficacy to mammalian cell culture-derived antibody, and offer a cost effective alternative to large-scale mammalian cell culture production.     

An analysis of relative costs and potential benefits of different policies for antenatal screening for beta thalassaemia trait and variant haemoglobins

AIMS: To investigate the costs and potential benefits of different policies for antenatal screening for haemoglobinopathies in two multiethnic London communities. METHODS: 1000 consecutive antenatal patient samples referred to each of two London teaching hospital laboratories for haemoglobinopathy testing were investigated using the standard procedures of the laboratory in question. When the standard procedures did not include high performance liquid chromatography (HPLC), this technique was added, in order to assess its diagnostic value and cost-effectiveness. A comparison was made between the costs and potential benefits of universal testing for variant haemoglobins and beta thalassaemia trait using HPLC and the costs and potential benefits of universal testing for variant haemoglobins and selective testing for beta thalassaemia trait using the mean cell haemoglobin (MCH) as a screening test and less automated techniques than HPLC for definitive diagnosis. RESULTS: The costs of the two policies were found to be comparable, as the higher reagent/instrument costs of HPLC were offset by the lower labour costs. Universal testing of 2000 consecutive samples did not disclose any extra cases of beta thalassaemia trait which would not have been detected by universal screening and selective testing. However, six patients were found to have a haemoglobin A2 variant which can interfere with the diagnosis of beta thalassaemia trait. CONCLUSIONS: The introduction of universal testing by HPLC into British laboratories could be cost neutral and has potential benefits. If a higher cost is accepted then the greater degree of automation could be used to release skilled staff for other tasks within the laboratory.     

Autosomal dominant inheritance of left ventricular outflow tract obstruction

Most nonsyndromic congenital heart malformations (CHMs) in humans are multifactorial in origin, although an increasing number of monogenic cases have been reported recently. We describe here four new families with presumed autosomal dominant inheritance of left ventricular outflow tract obstruction (LVOTO), consisting of hypoplastic left heart (HLHS) or left ventricle (HLV), aortic valve stenosis (AS) and bicuspid aortic valve (BAV), hypoplastic aortic arch (HAA), and coarctation of the aorta (CoA). LVOTO in these families shows a wide clinical spectrum with some family members having severe anomalies such as hypoplastic left heart, and others only minor anomalies such as mild aortic valve stenosis. This supports the suggestion that all anomalies of the LVOTO spectrum are developmentally related and can be caused by a single gene defect.     

Regulation of T-cell receptor signalling by membrane microdomains

There is now considerable evidence suggesting that the plasma membrane of mammalian cells is compartmentalized by functional lipid raft microdomains. These structures are assemblies of specialized lipids and proteins and have been implicated in diverse biological functions. Analysis of their protein content using proteomics and other methods revealed enrichment of signalling proteins, suggesting a role for these domains in intracellular signalling. In T lymphocytes, structure/function experiments and complementary pharmacological studies have shown that raft microdomains control the localization and function of proteins which are components of signalling pathways regulated by the T-cell antigen receptor (TCR). Based on these studies, a model for TCR phosphorylation in lipid rafts is presented. However, despite substantial progress in the field, critical questions remain. For example, it is unclear if membrane rafts represent a homogeneous population and if their structure is modified upon TCR stimulation. In the future, proteomics and the parallel development of complementary analytical methods will undoubtedly contribute in further delineating the role of lipid rafts in signal transduction mechanisms.     

Prevalence and risk factors for latex allergy: a cross sectional study in a United Kingdom hospital

OBJECTIVES: To determine the prevalence and risk factors for symptoms related to gloves, and the relation between symptoms and immunological evidence of type 1 hypersensitivity to latex in a United Kingdom health care setting. METHODS: A cross sectional survey was carried out among 773 employees at a British hospital. A self administered questionnaire was used to collect information about symptoms related to gloves and associated risk factors in a sample of hospital staff who were likely to use gloves at work. All of those who reported symptoms suggestive of type 1 hypersensitivity were invited for skin prick testing and measurement of specific IgE to latex (RAST). RESULTS: Among the 372 responders, symptoms related to gloves were common, 49% reported redness or itching of the hands, 14% reported urticaria, and 6% reported chest tightness. However, the frequency of positive skin prick tests and RASTs was surprisingly low (only two subjects tested positive). CONCLUSIONS: These findings indicate the need for caution in the interpretation of symptoms related to gloves even when they seem to suggest type 1 hypersensitivity.

 

     

Lamotrigine in add-on therapy: assessment of efficacy in drug resistant epilepsy

The authors presented the results of treatment with lamotrigine (LTG, Lamictal) in 13 patients with drug resistant epilepsy (add-on therapy). There were 8f, 5m. aged 16-60 years, mean age 28.8 years. Generalized seizures occurred in 8 patients (62%). In this group there was 1 patient (aged 16 years) with the Lennox-Gastaut syndrome and 1 patient (aged 20 years) with valproate resistant juvenile myoclonic epilepsy. Complex partial seizures and complex partial with secondary generalization occurred in 5 patients (38%). Before LTG addition mean seizure frequency was from 3/month to several times/day. The mean duration of epilepsy was 16.6 years. The 8 patients were treated with CBZ and VPA, one with PHT and VPA, one CBZ and VGB. Monotherapy with VPA was introduced in 3 patients. After 6 months of treatment with LTG the efficacy was evaluated. 12 patients took LTG with VPA, 1 LTG with CBZ. Complete reduction of seizures was achieved in 3 cases (23%), at least 50% reduction in 3 patients (23%), reduction below 50% in 4 patients (31%). In 3 cases (23%) the results of treatment were negative (increase or no change in seizure frequency). Beneficial psychotropic effect was observed in 9 patients (69%). Adverse effects occurred in 2 patients (15%). Headache, vertigo, sleepness were observed in one case. Rash occurred in 1 patient (treated with LTG and VPA). After 6 months 3 patients were excluded from the study because of negative effects of treatment. LTG is helpful and well tolerated in drug-resistant epilepsy.     

Comorbidity in young patients with juvenile systemic lupus erythematosus: how can we improve management?

Clinical Rheumatology -     

Haplotype analysis in simplex families and novel analytic approaches in a case-control cohort reveal no evidence of association of the CTLA-4 gene with rheumatoid arthritis

OBJECTIVE: Cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) is a negative regulator of T cells and is, therefore, a strong candidate susceptibility gene for T cell-mediated autoimmune diseases. The association of CTLA-4 single-nucleotide polymorphisms (SNPs) with rheumatoid arthritis (RA) has been investigated previously, with inconsistent results. Recently, SNPs mapping to the gene (and not previously investigated in RA) have been associated with both type 1 diabetes mellitus and Graves' disease. The aim of this study was to investigate the association of the CTLA-4 polymorphism with RA. METHODS: Primer extension methods were used to genotype 5 haplotype-tagging SNPs (htSNPs) (-1722 T/C, -1661 A/G, -658 C/T, -319 C/T, and +49 A/G), and the TaqMan 5' allelic discrimination assay was used to genotype an additional 2 SNPs (CT60 and rs1863800) mapping to the CTLA-4 gene. Association to the 5 htSNPs was investigated using the transmission disequilibrium test in RA simplex families (n = 122). Allele frequencies for the htSNPs were also investigated in affected sibling pairs (n = 96) and unrelated controls (n = 173). For the SNPs CT60 and rs1863800, unrelated patients with RA (n = 759) were compared with controls (n = 755). RESULTS: No evidence for association to single markers or haplotypes of the 5 htSNPs was detected in either RA simplex families or the affected sibling-control cohort. Neither of the 2 SNPs recently associated with Graves' disease showed evidence for association in the unrelated patient-control cohort. CONCLUSION: No evidence for association of CTLA-4 with RA was detected using family or case-control methods.