bcl-2 immunoreactivity, human papillomavirus DNA, and cervical intraepithelial neoplasia.

The aim of this study was to identify the role of bcl-2 protein expression in precancerous lesions of the cervix in patients from Johannesburg, South Africa and to correlate this expression with human papillomavirus (HPV) status. Archival cervical biopsy specimens (n = 107) of normal squamous epithelia (n = 18), pure HPV squamous epithelial lesions (n = 15), cervical intraepithelial neoplasia (CIN) I lesions (n = 17), CIN II lesions (n = 26), and CIN III lesions (n = 31) underwent bcl-2 immunohistochemical analysis with use of the streptavidin-biotin complex/horseradish peroxidase system and nonisotopic in situ hybridization for the detection of HPV DNA. Although 45 (61%) of the 74 CIN lesions demonstrated bcl-2 protein expression in the epithelia, most seemed to be in a patchy basal cell distribution, with a 1+ to 2+ intensity. Furthermore, comparison of bcl-2 immunoreaction between the low and high grades of the CIN lesions did not reveal significant differences. In addition, there was no apparent link between the presence of HPV DNA and bcl-2 expression in the CIN lesions. In contrast to previous studies that showed an increase in bcl-2 immunostaining intensity with increasing severity of CIN, only 4 (5.4%) of our 74 CIN specimens satisfied this pattern. Hence, we suggest that bcl-2 protein expression might not play a significant role in the majority of CIN lesions in this population group and that it might not correlate with HPV status.

Distribution of glutathione S-transferases in the human ovary: an immunohistochemical study.

The glutathione S-transferases (GSTs) are a family of isoenzymes with several functions. These include the metabolism of endogenous and exogenous toxic compounds, an isomerase activity in steroidogenesis and intracellular transport. This study has used immunohistochemistry to demonstrate the distribution of the three classes of GST (alpha, mu and pi) in the human ovary at different stages of the menstrual cycle. Alpha-GST was found in cells related to steroid hormone production and probably acts as a delta4-5 isomerase. Mu-GST was predominantly found in the non-luteinized stromal cells and its function is obscure. Pi-GST was found in surface 'epithelial' inclusions and the media of arteries where it is thought to play a detoxifying role.

Sclerosing stromal tumors, thecomas, and fibromas of the ovary: an immunohistochemical profile.

The immunohistochemistry of 11 sclerosing stromal tumors (SSTs), 11 fibromas, and 5 thecomas was studied to determine criteria for the assessment of 5 densely sclerotic, calcified ovarian tumors of uncertain diagnosis occurring in young women. The results indicate that the staining pattern for alpha glutathione S-transferase can be used to distinguish SSTs, fibromas, and thecomas. CD34, by highlighting the vascular pattern and density, can be used to distinguish between SSTs and other tumors in the thecoma-fibroma group. Alpha-inhibin and calretinin mirrored the alpha glutathione S-transferase staining. Vimentin, smooth muscle actin, and muscle specific actin were generally positive, but desmin was negative in all but one tumor. These results suggest that at least four of the five tumors of uncertain diagnosis were SSTs that had undergone end-stage sclerosis and calcification.

bcl-2 and p53 protein expression in follicular lymphoma.

Recent studies have shown bcl-2 to be regulated by p53. Other studies have suggested an inverse relationship between p53 and bcl-2 protein expression in breast and colonic cancers and in a variety of subtypes of non-Hodgkin's lymphoma. This study investigates the relationship between bcl-2 and p53 protein expression and the correlation between these findings and the grade and cell type of follicular lymphomas according to the REAL classification. Paraffin-embedded nodal follicular lymphomas (n = 37) were subjected to bcl-2 and p53 immunohistochemistry on tissue sections using a three-step ABC system. Positive immunostaining for both oncoproteins was scored using a three-tiered scale: +, < 10 per cent cells; ++, 10-50 per cent cells; and ++(+), > 50 per cent cells (< 10 per cent was used as a cut-off to define negative tumours). Ninety-seven per cent (36/37) of follicular lymphomas expressed bcl-2 protein in all three grades, manifesting in the small cell (grade 1) through to the large cell (grade 3). p53 protein expression showed a pattern of increasing immunostaining with progression towards the high-grade follicular lymphoma: grade 1 = 6 per cent (1/16); grade 2 = 48 per cent (10/21); grade 3 = 100 per cent (6/6). Five cases comprised varying combinations of grades. This latter finding suggests a role for p53 mutation in the progression/transformation of follicular lymphoma. The mechanism, however, differs from that suggested in breast and colonic cancers, since an inverse relationship between bcl-2 and p53 was not demonstrated in the present study.

Human papillomavirus and schistosomiasis associated bladder cancer.

AIMS: To determine the human papillomavirus DNA status of schistosomal associated squamous cell carcinoma of the urinary bladder in South Africa. METHODS: Twenty five archival samples of bladder squamous cell carcinoma associated with Schistosoma haematobium were subjected to non-isotopic in situ hybridisation and the polymerase chain reaction for the detection of human papillomavirus 6, 11, 16, 18, 31, and 33 genotypes. RESULTS: Using these two techniques, none of the 25 cases was shown to harbour human papillomavirus DNA. CONCLUSIONS: This study abrogates the role of human papillomavirus in schistosoma associated bladder carcinoma in South Africa. It is suggested that other factors including nitrosamine exposure, p53 mutation, and additional unknown chromosomal events play a major role in the development of this parasite associated neoplasm.

Comparative analysis of biotin intranuclear inclusions of gestational endometrium using the APAAP, ABC and the PAP immunodetection systems.

AIMS/BACKGROUND: Intranuclear inclusions have been observed in gestational endometrial glands. Although resembling Herpes simplex virus infected cells, these nuclei have been shown to contain endogenous biotin. Hence, immunohistochemical systems using the avidin-biotin complex will result in cross reaction and false positivity. This study investigates a series of 10 gestational endometria (formalin fixed and paraffin wax embedded) with intranuclear inclusions using three different immunodetection systems with primary anti-biotin. RESULTS: Both the alkaline phosphatase anti-alkaline phosphatase (APAAP) and peroxidase anti-peroxidase (PAP) systems confirmed that the intranuclear inclusions were endogenous biotin. The streptavidin biotin complex (StreptABC) system produced a positive reaction in both test sections and controls (omitting primary anti-biotin) in the presence of prior blocking with free avidin and biotin. In addition, aberrant immunoreactivity was observed in adjacent nuclei/cytoplasm of endometrial glands and decidualised stroma in the negative control of the PAP system. This was subsequently eliminated using microwave pretreatment prior to immunohistochemistry. CONCLUSION: The use of either the APAAP or PAP immunodetection systems (the latter with microwave pretreatment) is recommended for any immunohistochemical or non-isotopic in situ hybridisation investigation undertaken on gestational endometria.

Detection of herpes simplex virus DNA in spontaneous abortions from HIV-positive women using non-isotopic in situ hybridization.

The purpose of this study was to determine the prevalence of Herpes simplex virus (HSV) endometritis in spontaneous abortions in HIV-positive women using non-isotopic in situ hybridization (NISH). Post-abortal endometrial curettings from 18 HIV-positive women were investigated for the presence of HSV-1 and HSV-2 DNA with NISH. In addition, 18 unselected post-abortal endometrial curettings in HIV-negative women were used as controls, together with samples of normal proliferative and secretory endometrium. Thirteen of the 18 specimens (72 per cent) from the HIV-positive study group demonstrated the presence of HSV DNA, while 2 of the 18 HIV-negative group (11 per cent) showed a positive signal. Although the prevalence of HSV endometritis in the HIV-positive group was significantly higher than in the HIV-negative group (P < 0.05), a causal role for the virus in inducing the abortion remains to be determined. In addition, the significance of HSV endometritis with regard to the clinical management of HIV-positive patients is as yet uncertain.

Colonic cell proliferation in two different ethnic groups with contrasting incidence of colon cancer: is there a difference in carcinogenesis?

Most studies on colorectal carcinogenesis suggest a field defect, preceding overt development of cancer. The low incidence of adenomatous polyps in the African population, however, suggests that there may be an alternative route for cancer development. The aim of the study was to discover if the difference in incidence of colorectal cancer in Africans compared with the white population is reflected in a different pattern of cell proliferation. Histological normal mucosa from 30 patients (15 white South African (W), 15 South African Africans (A)) with confirmed colon cancer were examined. Proliferating cells were detected using the Ki-67 antigen. In addition, cell proliferation data were obtained, from 30 age matched controls (15 Africans, 15 white South Africans), without colorectal disease. The African controls were significantly younger (mean (SD) (A: 42 (20), W: 66 (13), p < 0.05)) than the white controls. The second control group had a significantly higher mean (SD) total labelling index (W: 11 (3), A: 6 (4), p < 0.05). In addition the proliferative pattern of the white group without evidence of colorectal cancer showed a comparatively large amount of dividing cells in compartment 2, compared with African controls (mean (SD) (W: 21 (8), A: 9 (8), p < 0.05)). Mucosa from Africans with cancer showed a proliferative pattern with the same increased total labelling index (A: 15 (5), W: 16 (6), p = NS, phase II proliferative lesion) and an even more pronounced upward expansion (phase I proliferative lesion) compared with white cancer patients. This suggests that the mechanism of colorectal carcinogenesis is similar in Africans and the white population. The lack of clinical evidence of the adenoma-carcinoma sequence, and the incidence of cancer at a comparatively young age in Africans may be explained by the fact that colorectal cancer in this ethnic group behaves more aggressively and that adenomatous polyps are rapidly converted into overt cancer before detection.