The assessment of proliferating cell nuclear antigen (PCNA) immunostaining in the uterine cervix and cervical squamous neoplasia.

This is a retrospective study, in which PC10, a monoclonal antibody against proliferating cell nuclear antigen (PCNA) was used in the assessment of 20 cases of FIGO stage IB cervical carcinoma, 30 cases of CIN, 10 cases of koilocytosis and 20 cases in which the transformation zone was histologically normal. The results showed that in the normal transformation zone the proliferative compartment was confined to the first 1-2 suprabasal cell layers. In CIN the pattern of staining corresponded to the grade of the lesion. In viral wart lesions occasional koilocytes demonstrated strong nuclear staining. In all cases of stage IB cervical carcinoma the PC10 index was high, irrespective of tumor grade response to treatment.

Glutathione S-transferase expression in the human testis and testicular germ cell neoplasia.

Glutathione S-transferase (GST) isoenzyme expression is altered in a variety of neoplasms and the enzymes are implicated in metabolism of carcinogens and resistance to drugs, including cisplatin. We have studied GST Alpha, Pi, Mu and microsomal isoenzyme expression by immunohistochemistry in normal and cryptorchid testes, intratubal germ cell neoplasia (ITGCN), seminoma and non-seminomatous germ cell tumours. In 16 stage II-IV malignant teratoma intermediate (MTI) both orchidectomy and post-treatment residual surgical masses were studied. All four isoenzymes were strongly expressed in Leydig and Sertoli cells. GST Pi was absent from normal spermatogonia but strongly expressed by the neoplastic germ cells of ITGCN and seminoma. GST Pi was strongly expressed in all elements of teratoma, irrespective of differentiation. There were no qualitative differences in expression between primary and post-chemotherapy metastases. GST Alpha expression in teratoma correlated with epithelial differentiation. GSTs may be important in normal spermatogenesis and protection of germ cells from teratogens and carcinogens. They may have a role in testicular tumour drug resistance but this role is not well defined. GST Pi is a new marker for ITGCN.

External quality assurance in histopathology: experience of the east of Scotland scheme.

AIMS: To examine the overall organisation of a voluntary external quality assurance scheme in histopathology, selection of case material and marking systems; and to assess the scheme in relation to contemporary histopathological practice. METHODS: Case material was derived from all participating departments and a positive marking system was used throughout the scheme. RESULTS: The mean response rate by those agreeing to participate was 66% and remains stable. The mean score of each set (n = 8) was high (63-80%) but scores about the mean varied widely in each set. The positive marking system was satisfactory and provided information equivalent to negative and weighted marking systems. The use of local coordinators providing the link between the central organiser and individuals has spread the administrative load and facilitated the introduction of small biopsy specimens. The selection of suitable case material has proved difficult at times. CONCLUSIONS: The scheme has an important role in histopathology quality assurance. It has been operative for four years and is widely accepted in the east of Scotland; it can be adapted to suit local circumstances.

The long-term retention of platinum in human tissues following the administration of cisplatin or carboplatin for cancer chemotherapy.

Mass spectrometry has been used to study the distribution and retention of platinum in the tissues of patients following the administration of cisplatin or carboplatin. Blood platinum was measured up to 2 years and renal excretion up to 5 years after treatment. Platinum concentrations in plasma and red cells fell according to a power function, approximately as the inverse square of the time after administration. The concentration in the urine fell more slowly. Necropsy samples were used to examine the distribution of platinum in various human organs up to 17 months after treatment. The highest concentrations were found in the liver, which retained approximately 2% of the dose. Although the results were scattered between patients, there was little loss of platinum after about 1 month. The prolonged retention of platinum may be relevant to long-term toxicity.

Prospective study of quantitative aspects of audit in a large general histopathology laboratory.

A non-computerised method of accurate prospective analysis of the quantitative aspects of the work of a general histopathology laboratory was devised. The method entails monitoring the progress of all biopsy and cytology specimens through the laboratory during selected monthly periods of study. The data collected include details of specimen type, block/section/stain details for each specimen, and information about the timed progress through technical, medical, and secretarial stages of specimen/report handling. The results give a detailed breakdown of the biopsy and cytology workload of this department. They give information about the rate of passage of specimens through the system and identify reasons for delay in the reporting of some cases. The method is easy to operate and will allow for the analysis of specific effects--for example, staff changes--on the efficiency of the department. The data will also provide some of the information required for the costing of histopathology laboratory services, and the type of information obtained will probably become a necessary requirement for laboratory accreditation.

Paradoxical embolisation of a catheter fragment to a coronary artery in an infant with congenital heart disease.

Six weeks after cardiac catheterisation via the right femoral vein an infant underwent an anatomical correction for transposition of the great vessels and closure of a large ventricular septal defect. The patient died intraoperatively as a result of severe left ventricular dysfunction. Necropsy showed an old myocardial infarction associated with thrombosis of the circumflex coronary artery. Electron probe x ray analysis showed that foreign refractile material within the thrombus contained bismuth, an element used in the construction of some cardiac catheters. This is believed to be the first report of "paradoxical" coronary embolisation of catheter-derived material and highlights the usefulness of electron probe x ray analysis.