Benign intracranial hypertension and recombinant growth hormone therapy in Australia and New Zealand

Benign intracranial hypertension (BIH) is reported in three children from Australia and one from New Zealand, who were being treated with recombinant human growth hormone (rhGH). Three males and one female, aged between 10.5 and 14.2 y, developed intracranial hypertension within 2 weeks to 3 months of starting treatment. A national database, OZGROW, has been prospectively collecting data on all 3332 children treated with rhGH in Australia and New Zealand from January 1986 to 1996. The incidence of BIH in children treated with growth hormone (GH) is small, 1.2 per 1000 cases overall, but appears to be greater with biochemical GHD (<10IUml ^-1), i.e. 6.5/1000 (3 in 465 cases), relative risk 18.4, 95% confidence interval 1.9-176.1, than in all other children on the database. The incidence in patients with Turner's syndrome was 2.3/1000 (1 in 428 cases). No cases in patients with partial GHD (10–20 IUml ^-1) or chronic renal failure were identified. Possible causative mechanisms are discussed. The authors'practice is now to start GH replacement at less than the usual recommended dose of 14IUm-² week^-1 in those children considered to be at high risk of developing BIH. Ophthalmological evaluation is recommended for children before and during the first few months following commencement of rhGH therapy and is mandatory in the event of peripheral or facial oedema, persistent headaches, vomiting or visual symptoms. The absence of papilledema does not exclude the diagnosis.     

O,O′-二烷基-O″-(5-取代-3-苯并噻吩乙腈肟)磷酸酯及硫代磷酸酯的合成

合成了18个O,O′-二烷基-O″-(5-取代-3-苯并噻吩乙腈肟)磷酸酯及硫代磷酸酯类化合物(Ⅰ_1～18)。初步杀螺试验结果表明,其中5个化合物,即Ⅰ_2,3,7,11,12有明显的杀螺增效作用。     

Care of diabetic patients in hospital clinics and general practice clinics: a study in Dudley.

A five year retrospective casenote review was undertaken of 452 patients attending 11 different general practice diabetic clinics, and 506 patients attending a diabetic clinic at hospital A and 210 patients attending a diabetic clinic at hospital B. The populations attending the clinics, the degree of glycaemic control achieved and the monitoring for the development of diabetic complications were investigated. Insulin dependent patients comprised 57.9% of patients attending the diabetic clinic at hospital A, 35.7% at hospital B and 25.0% of patients attending the diabetic clinics at general practices. Of these 55.6%, 37.3% and 30.1% respectively received multiple daily insulin injections. Hospital A had a higher proportion of patients under 40 years old than hospital B or the general practice clinics. The ages of diabetic patients attending the general practice diabetic clinics were broadly similar to those attending hospital B. Significantly more general practice patients, both insulin and non-insulin dependent, had a mean blood glucose level of less than 11 mmol l-1 compared with patients attending clinics at hospitals A and B (P < 0.001). Glycosylated haemoglobin levels did not differ between patients attending hospital A and the general practice clinics. More non-insulin dependent and insulin dependent diabetic patients attending the general practice clinics and hospital A had been monitored satisfactorily for diabetic retinopathy (general practice clinic 68.8% and 39.7% respectively, hospital A 61.7% and 43.5%) than at hospital B (43.0% and 19.4%). Referral rates among all groups for ophthalmological assessment were similar.(ABSTRACT TRUNCATED AT 250 WORDS)     

Con A activates an Akt/PKB dependent survival mechanism to modulate TCR induced cell death in double positive thymocytes

While low avidity ligation of the T cell receptor (TCR) leads to positive selection and further maturation of developing thymocytes providing the immune system with mature CD4(+) and CD8(+) (single positive) T cells, high avidity ligation triggers negative selection by apoptotic cell death and therefore the TCR repertoire is purged of autoreactive T cells. On peripheral T cells, however, high avidity ligation of the TCR triggers activation and survival not death. In the present study we used concanavalin A (Con A) and alpha-CD3 epsilon antibody to investigate a possible survival mechanism in connection with TCR ligation. Con A and alpha-CD3 epsilon were used in the study for the following reasons: (1) they both mimic the effects of high avidity TCR ligation by activating peripheral T cells, and (2) they trigger distinctively different physiological changes in developing thymocytes. While Con A supports events associated with cellular survival, alpha-CD3 epsilon induces apoptotic cell death. In our experimental system the TCR was cross-linked by Con A and alpha-CD3 epsilon in thymocytes of major histocompatibility complex (MHC) deficient thymus organ cultures, where signals from the TCR can be triggered on zero background signal level. We have found that TCR cross-linking by Con A and not by alpha-CD3 epsilon decreases the gene and protein expression of the pro-apoptotic molecule, Bad; and that Con A is capable of the activation of the survival signalling pathway including protein kinase B (Akt/PKB) independently of phosphatidyl inositol kinase (PI3K).     

Binding of gluten-derived peptides to the HLA-DQ2 (α1*0501, β1*0201) molecule,assessed in a cellular assay

The nature of the immunopathogenic relationship underlying the very strong association of coeliac disease (CD) to the HLA-DQ (A1*0501, B1*0201) genotype is not known, but probably relates to binding of gluten-derived epitopes to the HLA-DQ (α1*0501, β1*0201) heterodimer (DQ2). These epitopes have not yet been defined. In this study we have tested the binding of various gluten-derived peptides to DQ2 in a cellular assay using Epstein–Barr virus (EBV)-transformed B lymphocytes and murine fibroblast transfectants. One of these peptides (peptide A), which has previously been shown to exacerbate the CD lesion in vitro and in vivo, was found to bind to DQ2, albeit only moderately, lending further credence to its possible role in the pathogenesis of CD. The nature of peptide A's binding to DQ2 was explored with truncated and conservative point substituted analogues and compared with the published DQ2 binding motif, the results of which explain the observed level of binding.     

Recombinant mouse monoclonal antibodies with single amino acid substitutions affecting Clq and high affinity Fc receptor binding have identical serum half-lives in the BALB/c mouse.

The serum half-lives of three recombinant mouse monoclonal antibodies, differing radically in their ability to bind to Clq or FcRI but only minimally in structure, were determined in the BALB/c mouse following intravenous administration. The wild-type antibody, a chimaeric antibody comprising variable domains binding 3-iodo-4-hydroxy-5-nitrophenylacetate and constant domains of the mouse IgG2b isotype, was eliminated from the bloodstream with biphasic kinetics: alpha-phase, 0.5 days; beta-phase, 7.0 days. The alpha- and beta-phase half-lives of mutant recombinant antibodies with single amino acid substitutions, either Glu 235-Leu allowing binding to the mouse FcRI, or Lys 322-Ala reducing Clq binding 30-fold, were indistinguishable from those of the wild-type antibody demonstrating that the biological half-life of intact mouse IgG is independent of the ability to bind Clq or FcRI. The major implication of the present study is that IgG molecules which have been genetically engineered to eliminate interaction with other components of the immune system should retain the long half-life typical of natural antibodies.