Search PubMed⌕ Search

Biomedical subjects

A G Nicholson

Publications and source records attributed to A G Nicholson.

96 records · Page 6Linked to original sources
PubMed1994

Effect on lymph node status of triple levelling and immunohistochemistry with CAM 5.2 on node negative colorectal carcinomas.

Several papers have recently assessed whether immunohistochemistry increases the accuracy of staging in node negative colorectal carcinomas, by showing micrometastases. The results have been contradictory. In this paper 542 nodes which were negative for tumour on routine sectioning, were stained with CAM 5.2. In addition, the tissue was levelled three times, this technique being more economical, to see if either or both techniques increased the pick up of micrometastases. Six nodes showed positive staining of occasional cells in the subcapsular and paracortical sinuses, but these were cytologically benign on review and were not thought to represent metastatic tumour. Triple levelling did not show any additional micrometastases.

Colorectal Neoplasms↗
PubMed1993

Chemically induced cosmetic alopecia.

Cosmetic causes of scarring alopecia are poorly documented. They include traction alopecia and hot-combing. Recently, another group has presented in the South London area, related to misuse of chemical hair straightening agents. Affected patients are young, female, of Afro-Caribbean origin, and typically display hair loss on the vertex of the scalp. Histology shows a pattern of fibrosis and inflammation characteristic of the physical damage seen with other cosmetic procedures. This histological pattern is distinguishable from other non-cosmetic causes of scarring alopecia.

Adult↗
PubMed1993

Primary malignant melanoma of the rectum.

The diagnosis of a primary rectal malignant melanoma has been the subject of considerable argument for many years, principally on the grounds that extension from a primary anal lesion was often impossible to exclude. This paper provides evidence that certain melanomas can be recognized as primary rectal tumours, not only from careful anatomical assessment of the site of the tumour, but also by showing that they arise on a background of benign melanocytic proliferation in the rectal mucosa. The clinical presentation of these lesions, their possible mechanism of origin and their treatment is discussed.

Aged↗
PubMedDate not supplied

Interaction between mycobacteria and mucus on a human respiratory tissue organ culture model with an air interface.

Mycobacteria adhere specifically to extracellular matrix (ECM) and mucus with a fibrous, but not globular, appearance, in organ cultures of human respiratory mucosa examined by scanning electron microscopy. Previously, light microscopy sections made of tissue infected for 7 days demonstrated mycobacteria associated with mucus on the organ culture surface, and within submucosal glands in areas of damaged epithelium. The authors have now investigated the interactions between Mycobacterium avium complex (MAC), Mycobacterium tuberculosis (MTB), and Mycobacterium smegmatis (MS) and mucus by preincubating bacteria with purified mucins MUC5AC and MUC5B prior to inoculation onto the organ culture mucosal surface. They have also measured mucin production by the organ culture after mycobacterial infection. Mucus did not cause clumping of mycobacteria. There was a significant (P=.03) increase in the amount of fibrous mucus, but not globular mucus, observed on tissue inoculated with mucins compared to controls. The number of bacteria adhering to ECM was markedly reduced after incubation with mucins, which could indicate a protective effect. Mycobacterial infection did not increase mucin production by the organ culture. Mycobacterial adherence to mucins may play a role in the pathogenicity of mycobacteria in diseases such as cystic fibrosis, bronchiectasis, and chronic obstructive pulmonary disease (COPD), in which there are changes in mucus composition and clearance.

Air↗