Biomedical subjects

D P Magennis

Publications and source records attributed to D P Magennis.

4 recordsLinked to original sources

PubMed1999

Malignant melanoma: death by image and ignorance, diagnosis by surgical excision and laboratory investigation.

Malignant melanoma is now one of the most common cancers in the western world. Across Europe, the rise in annual incidence is 4-7%. The criteria for clinical and histological diagnosis are well established; however, an elaborate range of laboratory investigations can provide valuable supplementary information in difficult cases. In this essay, we highlight the incidence and impact of malignant melanoma worldwide, and outline the range of laboratory investigations that can be performed and are so vital in the diagnosis of problematic cases.

Biomarkers, Tumor↗

PubMed1998

Vascular patterns in the normal and pathological human adrenal cortex.

The vasculature of the adrenal gland has been studied by microinjection techniques in a variety of species. While there is general agreement about the overall patterns, some uncertainty still exists over the structure of medullary arteries and the connections between the sinusoids of the cortex and medulla. We have taken a new approach to these problems by applying immunohistochemical techniques to the human adrenal gland, identifying overall vascular patterns by endothelial expression of CD34 and muscular channels by smooth muscle actin. We have also examined adrenal nodules, adenomas and carcinomas to see whether these can be differentiated on the basis of their vascular patterns. The general pattern in the normal gland was similar to that found in injection studies, but there appeared to be more connections between sinusoids of the zona fasciculata than previously reported. There was direct continuity between cortical and medullary sinusoids. Medullary arteries were demonstrated as thin-walled vessels. Immunopositivity for smooth muscle actin was present in sinusoids, apparently in endothelial cells, suggesting that they may express this protein and thus have a contractile function. Macronodules and adenomas could not be reliably distinguished, both showing a rich network of sinusoidal vessels. Carcinomas showed marked disorganization, with large-calibre vessels interspersed with irregular networks of vessels of very small calibre.

Adrenal Cortex↗

PubMed1998

Angiogenesis: a new prognostic marker for breast cancer.

The past two decades have seen a huge increase in the study of angiogenesis or neovascularisation. With it has come realisation of the crucial role that angiogenesis plays in the growth and metastatic potential of carcinoma. One area where there has been particular interest is in the measurement of angiogenesis in breast carcinoma, with the hope that it may prove to be an independent prognostic indicator. As advances in breast cancer treatment have increased, so has the importance of assigning a patient to the optimal treatment regime. A number of studies have assessed tumour vascularity on sections immunostained with endothelial markers. Of these, the majority have found that highly vascular carcinomas have a poorer prognosis than those with low vascularity, although several studies have reported no correlation. These discrepancies may, in large part, be due to variations in the methods employed by different laboratories. At present, microvessel quantification in breast carcinoma has yet to prove it can reliably add a measurable amount of information to that already available from established prognostic indicators such as tumour size, nodal status, histological grade, and hormone receptor status. Although promising, further study is needed to establish the true value of measuring angiogenesis in breast cancer.

Breast Neoplasms↗

PubMed1997

Nuclear DNA in histological and cytological specimens: measurement and prognostic significance.

In recent years molecular biology techniques have provided new insights into the nuclear mechanisms associated with carcinogenesis. These have led to renewed interest in the measurement of nuclear DNA for diagnosis, prediction of prognosis, and assessing tumour response to therapy. Cytogenetics has been used successfully for this purpose for several decades, but technical problems have largely restricted this to haematological malignancies. However, technological improvements in flow cytometry and image analysis, together with new molecular biology techniques for measuring nuclear DNA, are providing useful information on nuclear ploidy and proliferative activity in solid tumours. Although many problems remain in this field, these new and improved techniques for measuring nuclear DNA are beginning to find a role in diagnostic pathology.

DNA, Neoplasm↗