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Biomedical subjects

K Cooper

Publications and source records attributed to K Cooper.

At least 109 records · Page 6Linked to original sources
PubMed1995

Human papillomavirus DNA in oesophageal carcinomas in South Africa.

Using morphological criteria, the presence of human papillomavirus (HPV) in oesophageal carcinomas has been inferred in patients from Finland and South Africa. However, studies to demonstrate the viral antigen in tissue sections of these tumours have proved disappointing. This study investigates 48 archival oesophageal carcinoma biopsies from South Africa for the presence of HPV DNA using non-isotopic in situ hybridization (NISH) with HPV DNA probes to HPV 6, 11, 16, 18, 31, and 33. HPV DNA sequences were detected in 25/48 (52 per cent) oesophageal cancers. HPV 16 was present in 84 per cent of the HPV-positive cancers. A NISH type 2 signal pattern (punctate/dot) was present in all HPV-positive tumours. This signal pattern was previously shown to represent integrated HPV DNA within host chromosome. Integrated HPV DNA in oesophageal cancers has also been demonstrated in patients from China and Japan. In addition, the prevalence of HPV DNA in oesophageal cancers from high-risk countries like South Africa (52 per cent) and China (49 per cent) would appear to be consistent.

Base Sequence↗
PubMed1995

Interphase cytogenetics: analysis of numerical chromosome aberrations in isolated cells.

Probes which recognize pericentromeric repetitive sequences can be used to determine numerical chromosome aberrations in interphase nuclei. Under appropriate stringency conditions, these probes decorate only the chromosome from which they were derived. It has been assumed that abnormalities of signal number in interphase nuclei reflect aneuploidy rather than proliferation, but this has not been clearly demonstrated. In this paper, three alphoid probes (D3Z1, D11Z1, and DXZ1) were localized to the appropriate chromosomes and the factors governing the production of reproducible signal distributions from three aneuploid cervical carcinoma-derived epithelial cell lines were investigated. Abnormalities of signal number represent numerical chromosome aberrations rather than changes associated with proliferation. Using four simple rules of interpretation, reproducible results can be obtained with minimal technical variation and selection bias. These results demonstrate that pericentromeric repetitive probes can be used reproducibly to determine numerical chromosome aberrations independent of cell proliferation in interphase nuclei, a necessary prerequisite for the application of this approach to the analysis of human tumours.

Aneuploidy↗
PubMed1995

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.

Abortion, Spontaneous↗
PubMed1995

The hematotoxic effects of 6-hydroxy-trans,trans-2,4-hexadienal, a reactive metabolite of trans,trans-muconaldehyde, in CD-1 mice.

6-Hydroxy-trans,trans-2,4-hexadienal (CHO-M-OH) is a metabolite of trans,trans-muconaldehyde (muconaldehyde or MUC), a microsomal hematotoxic ring-opened metabolite of benzene. In the present study, the toxicity of CHO-M-OH was examined. In order to assess potential toxic effects of CHO-M-OH on the maturation of erythroid cells in the bone marrow, 10-week-old male CD-1 mice were administered CHO-M-OH intraperitoneally and 59Fe incorporation into erythrocytes was measured. The uptake of 59Fe by erythroid cells was significantly inhibited at doses of 20, 25, and 30 mg/kg. There was no inhibition of 59Fe incorporation at a dose of 15 mg/kg. In other hematotoxicity studies, bone marrow cellularity, peripheral blood cells, and sulfhydryl contents in bone marrow cells were examined in mice administered CHO-M-OH intraperitoneally. An increase in the white blood cell count was observed in mice treated with 5 mg/kg/day for 16 consecutive days, while bone marrow cellularity and red blood cell parameters were not changed. Administration of 10 mg/kg/day for 16 consecutive days caused a significant decrease in sulfhydryls of bone marrow cells but no changes in bone marrow cellularity and peripheral blood parameters compared with controls. At a dose of 25 mg/kg/day for 4 days, there was a significant decrease in nucleated bone marrow cells. The white blood cell count, mainly lymphocytes, also significantly decreased. Our results indicate that CHO-M-OH is a hematotoxin in mice and conceivably could play a role in benzene toxicity.

Aldehydes↗
PubMed1995

Immunohistochemical detection of oncogene proteins and neuroendocrine differentiation in different stages of prostate cancer.

The progression of prostatic adenocarcinoma from localized disease to metastatic carcinoma appears to be a multi-step sequence. The expression of common oncogenes/oncosuppressor genes and the mediating effect of neuroendocrine tumor cells may play a role in this progression. The expression of the more frequently investigated oncogenes/oncosuppressor genes (p53, c-myc, c-erbB-2, bcl-2) and the presence of neuroendocrine cells were assessed in prostatic cancer tissue from patients with localized and metastatic cancer. These oncogenes/oncosuppressor genes were evaluated according to tumor stage and grade and their relationship to one another. Grade was not related to any of the oncogene markers or to the presence of neuroendocrine cells. Advancing stage was associated with a significant increase in p53 expression, while other markers remained constant in all stages. Neuroendocrine cells, p53, c-myc, c-erbB-2 and bcl-2 were rarely co-expressed at any stage of prostate cancer.

Carcinoma↗
PubMed1995

Schistosomiasis and prostate cancer.

In endemic geographical areas schistosomiasis has been implicated as an etiological agent in the pathogenesis of bladder, colorectal and renal carcinoma. In particular bladder cancer commonly occurs in such geographic locations almost 2 decades earlier than in non-endemic areas. A relationship between prostate cancer and bilharzial infestation is not established. This is a report of 3 cases of co-existent schistosomiasis and prostatic adenocarcinoma occurring in unusually young patients.

Adenocarcinoma↗
PubMed1995

Botryomycosis of the liver.

A case of visceral botryomycosis of the liver in a 50-year-old man is reported. The clinical diagnosis was hepatocellular carcinoma. Pathological examination of the surgically resected specimen demonstrated microabscesses containing gram- positive microorganisms with surrounding fibrosis replacing liver parenchyma. An immune deficiency state was not demonstrated. Recognition of this condition is important because of its clinical confusion with malignancy and its histological similarity to actinomycosis, nocardia, and eumycotic infections.

Carcinoma, Hepatocellular↗
PubMed1995

Rheumatic Aschoff nodules revisited: an immunohistological reappraisal of the cellular component.

Rheumatic fever is still the leading cause of acquired heart disease in children and young adults in developing countries. Recent reports have documented a rising incidence of rheumatic fever in both the USA and Europe. The disease is characterized by specific lesions in the heart muscle and valves called Aschoff nodules. The Aschoff nodule has been neglected in the last few decades as most of the studies were conducted in the 1960s on autopsy tissues. This study examines Aschoff nodules using heart valve material obtained at valve surgery with updated commercially available immunohistochemical antibodies to determine the phenotypic characteristics of the cells involved in the formation of these lesions. Fifteen cases of rheumatic valvulitis, as indicated by the presence of Aschoff nodules, were examined. The Anitschkow and Aschoff cells stained prominently with macrophage markers. Three stages of nodules with Aschoff and Anitschkow cells were identified: stage 1, central fibrinoid necrosis without lymphocytes, stage 2 with occasional T lymphocytes (< 10) and stage 3 with lymphoid aggregates containing both T- and B-lymphocytes (with occasional admixed macrophages). We propose that the stage 1 lesion is the earliest granulomatous stage with the lymphoid aggregates being a later stage in the development of Aschoff nodules. The Aschoff and Anitschkow cells demonstrated mitotic activity and stained with antibodies to the proliferation cell nuclear antigen (PCNA) suggesting that the multinucleated giant cells may be formed, at least partially, by nuclear division rather than fusion.

Biomarkers↗
PubMed1995

HPV typing of vulvovaginal condylomata in children.

OBJECTIVE: To determine the human papillomavirus (HPV) subtypes in vulvovaginal warts in prepubescent children. DESIGN: Histopathology case series. SETTING: Outpatient and gynaecology clinics of hospitals in the greater Johannesburg area. PATIENTS: All cases of vulvovaginal warts diagnosed in children under the age of 12 years received at the South African Institute for Medical Research, Johannesburg, during the period 1 January 1991 to 31 December 1993. MAIN OUTCOME MEASURES: Positivity for "genital' HPV types 6, 11, 16, 18, 31, 33 and 35 using non-isotopic in situ hybridisation (NISH) and polymerase chain reaction (PCR). RESULTS: Eight of the 9 vulvovaginal warts contained HPV 11 when assessed by means of NISH (89%). PCR amplified HPV DNA in all 9 (100%) of the biopsies. CONCLUSION: Detection of genital subtypes of HPV in childhood condylomata acuminata points strongly to sexual abuse, but should only be used as a guide to further investigation by a multidisciplinary team.

Child↗