Mycotic keratitis: profile of Fusarium species and their mycotoxins.

In this study, Fusarium species isolated from 29 patients with mycotic keratitis were identified and tested for their ability to produce mycotoxins. Members of the F. solani species complex (Fs complex) were the predominant species isolated, followed by F. verticillioides, F. dimerum, members of the F. oxysporum species complex Fo complex), F. incarnatum, F. chlamydosporum and F. lateritium. Of these, 76% of the Fusarium isolates produced fusaric acid, moniliformin or fumonisin B1. Many of the fusaria isolated are common aetiological agents of mycotic keratitis infections. However, F. incarnatum, F. chlamydosporum and F. lateritium have previously not been found in this infection. These findings indicate that a greater variety of fusarial species are becoming associated with mycotic keratitis infections. This paper further demonstrates the mycotoxin-producing ability of these clinical isolates and assesses cellular cytotoxicity.

P53 codon 72 polymorphism and human papillomavirus type in relation to cervical cancer in South African women.

The usefulness of the arginine (Arg) residue at codon 72 of the p53 tumor suppressor gene as a marker for the risk of cervical cancer remains unclear. Studies to date have focused mainly on Caucasian subjects despite marked ethnic variations in both the p53 polymorphism and the frequency of cervical carcinoma. Furthermore, not all studies have taken into account the type of human papillomavirus (HPV) infection present. In this study, undertaken at King Edward VIII Hospital, Durban, South Africa, we determined the p53 codon 72 status in 281 black South African women with cervical cancer and 340 ethnically matched healthy control subjects. In addition, HPV DNA was confirmed in 190 cervical tumors and the viral type determined. Results showed that overall more cancer patients than control subjects had an Arg allele at codon 72 with respect to both genotype and allelotype (P < 0.05). A significantly higher (P < 0.001) Arg allele frequency (55%) was also observed in patients whose tumors contained low or intermediate risk HPV DNA compared with control subjects (31%); the Arg homozygosity rate was 34% and 9% in patients and controls, respectively (P < 0.001). In contrast, patients harboring HPV 16/18 infections showed no differences in p53 status compared with controls. It would appear that, in the absence of HPV 16/18 infections, the Arg allele at codon 72 of the p53 tumor suppressor gene may constitute a risk factor for carcinogenesis of the cervix.

Immunolocalisation and endothelin-1 values In pre-eclampsia: an immunocytochemical study.

Maternal plasma ET-1 levels and the immunolocalisation of ET1 in the fetal membranes of pre-eclamptic primigravidae at >/=28 weeks, gestation were studied. The levels of maternal plasma ET1 and immunoreactive ET-1 were increased in pre-eclampsia. Immunoreactive ET-1 was localised in the amnion, chorion and decidua of normal pregnant women as well as those with preeclampsia-eclampsia. Intense labelling was observed in moderate pre-eclampsia (BP 140/90 - 170/110 mmHg) with very intense labelling in severe pre-eclampsia (BP >170/110 mmHg), especially in the amniotic epithelium, chorionic villi, maternal blood vessels, cytotrophoblasts and giant cells of the decidua. The increased ET-1 levels demonstrated in fetal membranes of pre-eclamptic women are probably produced in a paracrine and/or autocrine manner, contributing to the hypertension, vasospasm and fetal growth restriction characteristic of the syndrome. A larger study would be required to show significant change in endothelin production in pre-eclampsia.

The p53 codon 72 polymorphism in black South African women and the risk of cervical cancer.

The p53 codon 72 genotype was examined in blood samples taken from 121 Zulu-speaking black South African women with histologically proven squamous carcinoma of the cervix. Freshly biopsied tumour tissue was also available for human papillomavirus subtyping from 100 of these women. A control group consisted of 251 healthy race-matched women attending a contraceptive service facility. The results show that there were no statistically significant differences in the frequency of the homozygous arginine genotype between patients with cancer of cervix, irrespective of human papillomavirus status, and healthy controls. This finding suggests that the arginine allele does not predispose towards viral tumour genesis in this population, and supports the findings of research done in other ethnic groups.