Comparison of polymerase chain reaction and Chlamydiazyme for the detection ofChlamydia trachomatis in clinical specimens

An attempt was made to improve laboratory diagnosis ofChalmydia trachomatis and to validate the Abbott Chlamydiazyme confirmatory test used at present by comparing the polymerase chain reaction (PCR) procedure and the Abbott enzyme immunoassay. A total of 275 routine clinical specimens representing a range of positive and negative findings by Chlamydiazyme were retested by PCR. The procedures demonstrated 99 % concordance for specimens with optical density (OD) readings above the Chlamydiazyme cut-off of 0.1, but PCR was confirmed to be significantly more sensitive (p<0.025) for specimens with OD values between 0.05 and 0.09. Specimens in this range should be retested routinely by PCR.     

Pituitary macroadenomas associated with hyperprolactinaemia: immunocytochemical and in-situ hybridization studies

OBJECTIVE: We have assessed whether in-situ hybridization for prolactin messenger RNA (mRNA) provides additional information for the classification of pituitary macroadenomas associated with hyperprolactinaemia. DESIGN: In-situ hybridization for PRL mRNA was performed on surgical biopsies of pituitary adenomas and the results correlated with serum PRL levels and PRL immunoreactivity. PATIENTS: Twenty-one patients (11 men, 10 women) were included; five had normal serum PRL levels, 11 mild hyperprolactinaemia (less than 3000 mU/l) and five marked hyperprolactinaemia (greater than 3000 mU/l). MEASUREMENTS: Immunocytochemistry for PRL and in-situ hybridization for PRL mRNA were performed on surgical biopsies. RESULTS: Immunoreactivity for PRL was detected in tumours from all patients with serum PRL greater than 3000 mU/l and in one of 11 patients with mild hyperprolactinaemia. Positive signal for PRL mRNA was detected in four of five immunopositive cases studied, in a further two cases with mild hyperprolactinaemia, and in one tumour associated with normal serum PRL level. CONCLUSIONS: In-situ hybridization provides evidence of PRL gene activation in the absence of immunoreactivity for prolactin. This may reflect low levels of hormone storage or defective translation of the mRNA.     

Platelet function in hairy-cell leukaemia

A quantitative study of various aspects of platelet function was carried out in eight patients with typical hairy-cell leukaemia (HCL). In at least two patients platelet aggregation was convincingly reduced to more than one aggregating agent (ADP, adrenaline, collagen, thrombin, and ristocetin). Granular storage capacity for {(14)C} 5-HT was reduced in five of the six patients tested. The two patients with definitely abnormal aggregation had the greatest reduction in granular storage pool and the longest bleeding times of those tested but, like the other patients, they did not have a clinical haemostatic defect. It was concluded that a granular storage pool defect (SPD) was at least partly responsible for aggregation abnormalities in HCL since the platelet release reaction in response to thrombin appeared to be normal. All our patients ran a chronic course uncomplicated by any of the factors known to predispose to a platelet SPD acquired in the circulation. Although in the one patient tested before and after splenectomy there was some improvement in platelet aggregation after operation, there was no clear general relationship between defective platelet function and either previous splenectomy or platelet count. Since a direct involvement of the megakaryocytic series in the underlying cell proliferation of HCL seems unlikely, it is concluded that the platelet defect can most reasonably be attributed to the production of abnormal platelets as a result of marrow fibrosis and/or infiltration by hairy cells.