Preliminary validation of a prediction model for the short-term growth response to growth hormone therapy in children with idiopathic short stature

A discriminant scoring system, using multivariate analysis, has been developed for pretreatment prediction of responsiveness to a 6-month trial of growth hormone (GH) treatment in short children with subnormal growth velocity, but without GH deficiency. Inclusion criteria included a birth weight above 2.5 kg, height below the 3rd centile for chronological age, height velocity below the 25th centile for bone age, no signs of puberty, a maximal GH response to pharmacological stimulation of above 10 μg/l and treatment with GH at a dose of 12–16 IU/m²/week. Children with an increase in height velocity greater than 2.5 cm/year after therapy were considered to be responders. Pretreatment clinical data from 67 patients were employed in a discriminant analysis in order to establish the model. The scoring system developed was as follows: score = -0.4 + 0.92X₁– 0.87X₂, where X₁ is the height velocity SD score (SDS) for chronological age, and X₂ is the bone age SDS for chronological age. This model had a specificity of 96.3% and a sensitivity of 92.5% in predicting the responsiveness to GH. The model has subsequently been applied to a group of 14 patients in order to establish its validity; in this group its sensitivity was 83.3% and its specificity 100%. These preliminary data suggest that the model can be used as a guideline for selecting short, slowly growing, non-GH-deficient children who will respond to short-term GH therapy.     

Tendon echogenicity: ex vivo study

Recent publications discussing the echogenicity of normal tendon have described it variously as hyperechoic or hypoechoic. Since the echogenicity of tendon has been used to define normality and abnormality, certain knowledge of the normal echogenicity of tendon is crucial. Fresh tendon and muscle from beef hock was scanned with sector- and linear-array-transducer imaging at multiple angles and distances. The echogenicity of tendon was found to be very angle-dependent, a characteristic known as anisotropy. Scanned perpendicular to its long axis with a linear-array transducer, tendon was significantly more echogenic than muscle. With a change in angle, echogenicity of tendon decreased relative to that of muscle (the echogenicity of muscle remained the same), becoming isoechoic at angles of 2 degrees -7 degrees and hypoechoic at greater angles. Tendon studied with a sector transducer exhibited varying echogenicity. If echogenicity is used as a diagnostic criterion, the angle of the interrogating ultrasound beam must be very specifically defined.     

TCR V alpha chain expression influences reactivity to the hapten TNP

We have recently demonstrated a remarkable selection of in vitro cultivated, TNP-specific polyclonal T cell lines for the expression of a TCR beta chain encoded by the V beta 8.2 gene. The goal of the present study was to analyse V alpha usage in V beta 8.2 T cells responsive to TNP, using TNP-specific T cell lines derived from three common strains of mice, as well as from V beta 8.2 transgenic mice. Results indicate that in vitro TNP stimulation of T cells from TNP- immune mice results in significant skewing of V alpha usage among responding V beta 8.2+ T cells, with overexpression observed for V alpha 3.2 and V alpha 8. These results indicate that V alpha expression influences recognition of TNP by T cells, and suggest that the hapten TNP might be recognized like typical peptide antigens by combinatorial TCR alpha and beta contact sites.      

The effects of benzodiazepines on hormones in women with idiopathic hirsutism

A single blind study was planned to investigate whether benzodiapines would reduce androgens in women with idiopathic hirsutism. Placebo was given for the first month followed by four months of a benzodiazepine (chlorazepate 15 mg nocte or diazepam 10 mg nocte ). Plasma samples were collected during the follicular and luteal phases of each therapy month. Hair growth was assessed monthly. Eighteen women concluded the five months of the trial of whom ten received chlorazepate and eight diazepam. Comparison of follicular plasma samples during the placebo phase and fourth month of benzodiazepine found a significant increase in sex hormone binding globulin and a significant decrease in dehydroepiandrosterone sulphate with benzodiazepine therapy. No significant effects on hair growth were observed. A longer therapy time may be needed to demonstrate effects of benzodiapines on hirsutism. Further studies are needed to determine whether benzodiazepines affect hormonal parameters in normal men and women.