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Biomedical subjects

L Vass

Publications and source records attributed to L Vass.

At least 19 recordsLinked to original sources

Fine needle aspiration cytology: a survey of current European practice.

Fine needle aspiration cytology (FNAC) is practised widely throughout Europe. The majority of countries have dedicated cytopathologists as well as histopathologists practicing cytology. Despite this, FNAC is performed mostly by clinicians and radiologists except in the larger centres with dedicated staff with a special interest in cytopathology. The advent of One-Stop diagnostic services and image-guided procedures are prompting further development of FNAC clinics where cytopathologists take their own samples, issue reports in the same clinical session and take extra material for ancillary tests to complete the diagnosis. The volume of FNAC work varies accordingly; in dedicated centres FNAC represents up to 80% of the workload whilst, in the majority of countries, it represents one quarter or less. Hence, the rate of inadequate FNAC varies widely, depending on the local sampling policies and the organ, but does not exceed 25% in any of the countries. The most sampled organs are breast and thyroid, followed by lymph nodes. Most countries have dedicated training in cytopathology for pathology trainees, the duration varying between 6 months and 2 years of the total training time. This discussion, focusing on European practices, highlights the heterogeneity of FNAC activity but also its success in many centres where it is practiced to a high standard, particularly in breast, thyroid and lymph node pathology. The relatively high rate of inadequate material in some centres reflects local policies and calls for greater uniformity of FNAC practice, particularly specimen sampling. To achieve this, the future direction should concentrate on specialist training, to include performing as well as interpreting FNAC, as part of the curriculum. Current emphasis on web-based training may not provide first hand experience of the FNAC procedure and should be supplemented by attending FNAC clinics and developing the technique to its full potential.

Biopsy, Fine-Needle↗

Immunohistochemical evaluation of versican, in relation to chondroitin sulphate, in canine mammary tumours.

The expression of increased amounts of versican, a chondroitin sulphate proteoglycan, in neoplastic tissues may play a role in promoting tumour cell proliferation and migration. This study investigated the immunolocalization of versican in normal and neoplastic canine mammary tissues, using antibodies 12C5 and 2B1, against different epitopes of the protein core of versican. Antibody CS56, recognising chondroitin sulphate (CS), was used to investigate the relation between versican and CS, which accumulates in canine mammary tumours. We found enhanced versican expression in both benign and malignant tumours, appearing in three main patterns: in periductal tissues, probably in association with basement membranes of ducts; in peripheral invasive areas of malignant tumours; and in spindle cell proliferations and myxoid areas of complex and mixed tumours. The 12C5 and 2B1 immunoreactivities co-localised in all types of tumours, and could be improved by chondroitinase digestion. The only exception was the abundant extracellular matrix (ECM) of spindle cell proliferations, particularly in myxoid areas of complex and mixed tumours, which displayed intense and diffuse 12C5 immunoreactivity and patchy or absent 2B1 and CS56 immunoreactivities; versican immunoreactivity could not be enhanced by chondroitinase digestion. The results indicate that versican is one of the extracellular matrix components characteristic of canine mammary tumours. It appears likely that in complex and mixed tumours versican exists in at least two forms, one of them lacking the CS attachment domain and the 2B1 epitope. Furthermore, the enhanced versican expression in the invasive areas of malignant tumours indicates the involvement of this proteoglycan in tumour cell invasion.

Animals↗

[Results of irradiation using different radiation sources in the treatment of malignant parotid tumors].

Patients with malignant parotid tumors were treated at two different centres with slightly ionizing radiation (110 patients) and neutron therapy (15 patients). The treatment results are compared. The principles of comparison applied in this analysis are identical. The histologic classification was made according to the W.H.O. recommendation of 1972 and the staging according to Becske. Local tumor control is the criterion applied in the comparative assessment of both methods. The analysis has shown that there is no significant difference in the treatment results within the individual stages of tumor's advancement after application of an orthovolt therapy and a telecobalt therapy. Patients treated in early stages (stages I and III) had a substantially higher rate of local tumor control (72%) than patients in advanced stages (46%, stages III and IV). A more favorable treatment results was achieved by neutron therapy in all stages of tumor's advancement. In this case the rate of patients with local tumor control (87%) was significantly higher than after radiotherapy with slightly ionizing radiation (46%).

Adenocarcinoma↗

Thyroid-bound Y-chromatin-like fluorescence in the nuclei of thyroid adenomas.

Brilliantly fluorescent supernumerary chromocenters indistinguishable from the Y-chromatin have been often found electively in the thyroid nuclei. The authors compared the occurrence of this Y-chromatin-like fluorescence in 31 thyroid adenomas obtained from 30 autopsy cases (10 males, 20 females) with non-adenomatous thyroid tissues of the same cases. All adenomas had follicular structure but one with papillary structure. The frequency class of Y-chromatin-like fluorescence of adenomas was lower in 15 cases out of 31 than that of the same non-adenomatous thyroid tissue. The Y-chromatin-like fluorescence had a negative count in 13 cases of 31 adenomas but only in 3 cases of normal thyroid tissues from 30 persons. The disappearance of the nuclei with Y-chromatin-like chromocenters is supposedly connected with cellular dedifferentiation of thyroid adenomas.

Adenoma↗

Non-random appearance of Y-chromatin-like fluorescence in the nuclei of thyroid and brain and its chromosomal background.

Non-random distribution of fluorescing chromatin bodies resembling Y chromatin was observed among the cell populations of various organs obtained by autopsy of 52 adults. This type of Y-chromatin-like fluorescence is more frequent in thyroid and brain than in other organs. The Y-chromatin-like bodies of thyroid nuclei are not closely correlated with the brilliantly fluorescing autosomal blocks of lymphocyte mitoses of the same persons, as it was demonstrated in surgical cases.

Cerebral Cortex↗