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Biomedical subjects

J Crocker

Publications and source records attributed to J Crocker.

At least 109 records · Page 6Linked to original sources
PubMed1990

Hemangioblastoma and renal clear cell carcinoma distinguished by means of the AgNOR method.

In view of the difficulty encountered in distinguishing between 2 degrees renal cell carcinoma (RCC) and hemangioblastoma (HBl) in the central nervous system, the AgNOR technique has been applied empirically to a series of 16 specimens of HBl, 5 primary RCC, and 6 specimens of secondary RCC in the CNS. To avoid tautology, the nature of these was confirmed by immunostaining for epithelial membrane antigen (EMA) and factor VIII-related antigen (FVII RAg). It was found that mean nuclear AgNOR counts in the stromal and endothelial cells of HBl exceeded significantly the counts in the tumor and endothelial cells of RCC, with no overlap in values. It is suggested that the AgNOR method is a useful adjunct in achieving the differential diagnosis of HBl and RCC in the nervous system.

Adult↗
PubMed1990

Sequential demonstration of nucleolar organizer regions and Ki67 immunolabelling in non-Hodgkin's lymphomas.

In order to investigate the relationship between the numbers of interphase silver-stained nucleolar organizer regions (AgNORs) and cell proliferation, we have studied prospectively a small series of non-Hodgkin's lymphomas (NHL). We applied the recently described double staining technique for sequential immunostaining and the AgNOR reaction to the same sections of tumour from each case. The immunostaining was performed with the antibody Ki67, known to demonstrate the nuclei of proliferating cells. A significant difference was found between the AgNOR scores in Ki67+ and Ki67- cells, the counts being much higher in the former than the latter. This was the case for both high- and low-grade NHL and is further evidence that interphase AgNOR counts reflect cell proliferation level, at least in lymphomas.

Antibodies, Monoclonal↗
PubMed1990

Detection of HPV 6 and 11 in tumours of the upper respiratory tract using the polymerase chain reaction.

We have applied the polymerase chain-reaction (PCR) technique to benign and malignant squamous tumours of the pharynx and larynx and to nasal inverted papillomas to detect evidence of infection with human papillomavirus (HPV) 6 and 11. Each of these lesions tended to be infected with either or both of these but the prevalence of infection when compared with that of histologically normal biopsies from the nasopharynx was not significantly increased.

DNA, Viral↗
PubMed1990

Immunohistochemical staining with monoclonal antibody 32-2B to desmosomal glycoprotein 1. Its role in the histological assessment of urothelial carcinomas.

A series of transitional cell carcinomas of bladder were stained immunohistochemically with the monoclonal antibody, 32-2B, to desmosomal glycoprotein 1. All of the sections showed positive staining with the antibody. Assessment of staining intensity, by 3 independent examiners, revealed a strong negative correlation between density of desmosomal staining and degree of invasion (P = 0.012). Nests of strongly staining cells were identified in several invasive tumours, possibly indicating early squamous differentiation. Invasive tumour cells in the subepithelial stroma also stained strongly with the antibody. Correlation with clinical course, however, revealed no significant association between desmosomal staining and the incidence of recurrence or progression. It is suggested that staining with this antibody may be of value in detecting both stromal invasion and early squamous differentiation of transitional cell carcinomas. Both this and previous studies emphasise the value of this antibody as an epithelial marker in neoplasia.

Antibodies, Monoclonal↗
PubMed1990

Lamina propria eosinophils and mast cells in ulcerative colitis: comparison between Asians and Caucasians.

To investigate the theory of hypersensitivity in the colonic mucosa of Asian patients with ulcerative colitis the rectal biopsy specimens of Asian and Caucasian patients presenting with colitis were selectively stained for both eosinophils and mast cells. Comparisons between ethnic groups were made as well as the correlation to the blood eosinophil count and two variables of active ulcerative colitis--the blood leucocyte count and serum orosomucoid concentration. No correlation was found in either group between circulating and tissue eosinophils and no ethnic difference was identified in the lamina propria differential cell densities. The leucocyte count and serum orosomucoid concentrations, however, were significantly higher in the Caucasians. In the Asian group a strong negative association was found between the lamina propria eosinophil density and serum orosomucoids; in the Caucasian group there was a positive association between all blood variables. It is concluded that different mechanisms occur in the two ethnic groups and in Asians these might not be reflected by the more orthodox indices of colonic inflammation.

Adult↗
PubMed1990

Nucleolar organiser regions in kidney tumours and xanthogranulomatous pyelonephritis.

The AgNOR argyrophil technique was applied to clear cut examples of renal adenoma (n = 7), clear cell carcinoma (n = 9), and xanthogranulomatous pyelonephritis (n = 5). There was no significant difference between mean AgNOR counts per cell in adenomas and carcinomas, supporting the idea that there is a continuous spectrum of kidney tumours. Xanthogranulomatous pyelonephritis and clear cell carcinoma showed significant differences in mean AgNOR counts per cell, suggesting that the technique may be of use in distinguishing between these conditions, although further cases may need to be examined to confirm this.

Adenocarcinoma↗
PubMed1990

Lack of prognostic value of nucleolar organizer region enumeration in transitional cell carcinoma of the bladder.

Enumeration of silver-stained nucleolar organizer regions is of limited use in grading transitional cell tumors of the bladder. We attempted in this article to establish whether or not such a technique would be helpful in predicting the prognosis of such tumors within rather than between grades. In the study population of 11 high-grade transitional cell carcinomas of the bladder, no correlation was found between clinical outcome and mean nucleolar organizer region count.

Carcinoma, Transitional Cell↗
PubMed1989

Application of the AgNOR method to cell imprints of lymphoid tissue.

The argyrophil (AgNOR) staining technique for nucleolar organizer regions was applied to both cell imprint preparations and 3 microns sections of 40 specimens of lymphoid tissue (10 normal tonsil, 10 reactive follicular hyperplasia, and 10 low-grade and 10 high-grade non-Hodgkin's lymphomas). The mean AgNOR count per nucleus was higher for imprint preparations than for 3 microns sections for each group of specimens (P less than 0.01). The difference was particularly evident for specimens with high AgNOR counts, that is, the high-grade non-Hodgkin's lymphomas (pooled mean AgNOR count/cell 16.3 for imprints as opposed to 6.0 for 3 microns sections, P less than 0.0001). Furthermore, individual AgNOR dots were much more readily discerned in cell imprints than in sections, and this appears to be the method of choice if pathologists wish to at least approach absolute rather than relative AgNOR counts.

Humans↗
PubMed1989

The relationship between number of interphase nors and nor-bearing chromosomes in non-Hodgkin's lymphoma.

The ribosomal genes (located on the acrocentric chromosomes 13-15, 21-22) may be identified by their silver stained gene products, i.e. NOR related proteins. The NOR bearing chromosome activity can be observed at metaphase with the potential for all ten chromosomes to be positively stained. On the other hand, during interphase they fuse so that eventually only a single silver positive structure is seen in resting normal cells. Investigations of histopathological sections of non-Hodgkin's lymphoma (NHL) have demonstrated a correlation between the numbers of interphase NORs and the grade of tumour. There is generally a higher number of interphase in high-grade, and a lower number in low-grade tumours. This histopathological and cytogenetic study of 13 patients with NHL shows that the higher numbers of interphase NORs in the high-grade tumours is not necessarily a reflection of increased numbers of NOR-bearing chromosomes. Examples were found of high-grade neoplasms, showing the expected high numbers of interphase NORs, but not an increased number of NOR-bearing chromosomes. Conversely, some low-grade tumours, with the expected low number of interphase NORs, had increased numbers of NOR-bearing chromosomes. Our conclusion is that the interphase NOR number is related to factors other than chromosome numbers. We suggest that NOR numbers at interphase may be related to cell turnover. This is supported by previous investigations using DNA flow cytometry and the monoclonal antibody Ki67.

Chromosomes, Human↗
PubMed1989

How should we count AgNORS? Proposals for a standardized approach.

There is interest currently in the AgNOR technique, for NOR-associated proteins. In some cases, this technique enables the distinction to be made between certain grades of malignancy and may enable prognostic assessment. This paper attempts to suggest a standardized means for the enumeration of NORs in histological sections. Attention should be paid to rigorous technique and careful resolution of intranucleolar AgNOR dots. The timing of the reaction and fixation methods are also most important.

Humans↗
PubMed1989

Sequential demonstration of antigens and AgNORs in frozen and paraffin sections.

A technique has been designed which enables the sequential demonstration of nucleolar organizer regions (NORs) and various antigens, in both frozen and paraffin wax-embedded sections. The NORs were demonstrated by the standard argyrophil (AgNOR) method and the antigens were shown by either immunoperoxidase (PAP) or immunoalkaline phosphatase (alkaline phosphatase-anti-alkaline phosphatase or avidin-biotin-alkaline phosphatase) methodology. Clear, reproducible results were obtained and AgNOR sites were enumerated with ease. It is suggested that the sequential method may be of great use in the evaluation of AgNOR numbers in neoplasms, where cell populations are heterogeneous. Cell populations may be demarcated with accuracy prior to the counting the AgNORs.

Antigens↗
PubMed1989

Nucleolar organiser regions as indicators of post-surgical prognosis in canine spontaneous mast cell tumours.

The average number of nucleolar organiser regions per cell has previously been shown to correlate well with histological grading techniques for a variety of neoplasms in man, and may thus be of value as an aid to post-surgical prognosis. In this study 50 spontaneously arising, subcutaneous canine mast cell tumours were graded and the histological grade compared with the mean AgNOR count. For well differentiated neoplasms the mean count was 1.4 per cell compared with 6.3 for poorly differentiated neoplasms, while tumours of intermediate differentiation had a mean count of 3.2 per cell. Subsequent follow up studies revealed that the AgNOR count was an accurate prognostic indicator, 73% of dogs with a high mean count (greater than 4.9) being destroyed from tumour related disease compared with 33% with an intermediate count (1.7-4.8). No dog with a count of less than 1.7 has been destroyed because of tumour recurrence to date and the AgNOR count has proved to be a better and more objective prognostic indicator than either histological tumour grade or mitotic index. Since most dogs which develop recurrent mast cell tumours do so within 6 months of initial surgery, an assessment of the predictive value of AgNORs can be obtained more quickly in canine tumours than for comparable human neoplasms.

Animals↗