Browsing by Author "Silva, N."

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Accumulation of toxic metals in ectopic endometrial tissue
(Sri Lanka Medical Association, 2011) Silva, N.; Senanayaka, H.; Peiris-John, R.; Wickremasinghe, R.; Waduge, V.
INTRODUCTION AND OBJECTIVES: Aim of this study was to determine the association between heavy metals and endometriosis. METHODS: A case-control study was conducted in a tertiary care hospital comparing 50 cases of endometriosis with 50 age matched controls confirmed by laparoscopy or laparotomy. Blood samples and ectopic endometrial tissue samples were obtained and digested with supra pure 65% HNO3. Samples were analysed for cadmium by graphite furnace atomic absorption spectroscopy (GFASS). In a subset of cases (n=30) and controls (n=40) samples were analyzed for nickel, lead and zinc by Total Reflection X-ray Fluorescence (TXRF) technique. T-tests and Spearman's correlation coefficient were used for analysis. RESULTS: Cases had significantly higher (p=0.011) mean (+SD) blood nickel levels (1.69+1.18 ug/1) as compared to controls (0.96+0.94 ug/1). Blood levels of cadmium (0.75±0.46 ug/I vs 0.77 ±0.37 ug/1) lead (5.8S±1.25 ug/1 vs 3.45±1.25 ug/1) and zinc (123.02±2.49 ug/1 vs151.35 ±2.46 ug/1) were similar in the two groups (p=0.289, p=0.123s and p=0.339, respectively). Tissue samples had significantly higher (p=0.001, p<0.001, p=0.049 respectively) mean (+SD) levels of cadmium (2.86±0.61 ug/1 vs 0.8±0.48 ug/1) nickel (8.64±0.4.12 ug/Lvsl.58±1.21ug/l) and lead (11.22±4.67 ug/1 vs 5.86±3.38 ug/1) compared to blood levels. Mean (+SD) blood levels of zinc (117.48 ±2.64 ug/1) was higher (p<0.001) than that in tissues (27.54±6.65 ug/1). There was a positive correlation between blood zinc levels and tissue zinc levels (r=0.417;p= 0.034) but there was no correlation between blood and tissue levels of cadmium, nickel and lead (r=0.237,p=0.085; r=0.372,^=0.113; r=0.70,/?=0.067, respectively). CONCLUSIONS: Cadmium, nickel and lead but not zinc accumulate in ectopic endometrial tissue.
Cadmium a metalloestrogen: are we convinced?
(Wiley, 2012) Silva, N.; Peiris-John, R.; Wickremasinghe, R.; Senanayake, H.; Sathiakumar, N.
Metalloestrogens are inorganic metal ions that bind to and activate oestrogen receptors. They are implicated in the aetiology of oestrogen-dependent diseases such as cancers of the breast and endometrium as well as endometriosis. Cadmium is one of the most studied metalloestrogens. In this review, scientific evidence for the oestrogenic effects of cadmium is critically evaluated to determine if there is sufficient evidence to support cadmium as an aetiological factor of oestrogen-dependent disease in humans. Results of the review indicated that, although the in vitro and in vivo evidence of the oestrogenic properties of cadmium was persuasive, evidence from population-based human studies remains conflicting. Considerable knowledge gaps exist on the potential oestrogenic effect of cadmium in humans. Research that focuses on bridging these knowledge gaps would be useful in preventing and managing oestrogen-dependent disease in humans
Demographic, biological and dietary characteristics associated with endometriosis in a group of Sri Lankan women
(Sri Lanka College of Obstetricians and Gynaecologists, 2011) Silva, N.; Senanarake, H.; Peiris-John, R.; Wickremasinghe, R.
OBJECTIVE: To identify demographic, biological and dietary factors associated with endometriosis in a group of Sri Lankan women. METHODS: A case-control study was conducted at two tertiary care hospitals. Women with endometriosis (n=150) were compared with age-matched controls (n=150) with no evidence of endometriosis, both confirmed by laparoscopy or laparotomy. Data were collected using an interviewer-administered questionnaire and a food frequency questionnaire. Means were compared using paired t-tests and chi square tests and odds ratios (OR) were used to determine associations between dichotomous variables. Conditional logistic regression analysis was done to adjust for potential confounding variables. RESULTS: The ethnic distribution, age at menarche, average length of the menstrual cycle and body mass index were similar in the two groups. The mean (+SD) duration of menstruation in the cases (4.11±0.11 days) was significantly higher than in the controls (3.47±0.16 days, p=0.01). Endometriosis was commoner among those with regular menstrual cycles (OR=3.108; 95% CI=1.473-9.627) and those having an education above Advanced Level (OR=1.729; 95% CI=1.041- 2.87). None of the food items was significantly associated with endometriosis. The risk of endometriosis was 2.084 times greater among those with an education above Advanced Level as compared to those having an education below Advanced Level (p=0.021) after adjusting for confounding factors. CONCLUSION: Among Sri Lankan women, endometriosis is commoner among those who are more educated.
Establishment of human endometriai stromal cell cultures as in-vitro models to test the effects of metalloestrogens in women with or without endometriosis
(Sri Lanka Medical Association, 2012) Silva, N.; Tennekoon, K.; Senanayake, H.; Samarakoon, S.; Fernando, S.; Wickremasinghe, A.R.; John, R.P.
INTRODUCTION: Effects of metalloestrogens like cadmium (Cd), lead (PbJ and nickel (Ni) are difficult to demonstrate in-vivo due to toxicity and therefore requires suitable in-vitro models. AIMS: To establish endometriai stromal cell (ESC) cultures as in-vitro models to demonstrate the effects of metalloestrogens in women with and without endometriosis. METHODS: Stromal cells were isolated from eutopic endometriai samples from five women with endometriosis (patients) and five women without endometriosis (controlsj. ESC cultures were established and maintained in RPMI medium. Cultures were treated with Cd, Pb and Ni at concentrations of 10-6M, 10-9M and 10-9M respectively. At 24 h and 48 h, cell number was counted using the Neubauer haemocytometer. Sulphorhodamine(SRB) cytotoxicity assay was used to test the effect of different concentrations of metals on ESC cultures. After 24 h of treatment, caspase levels in ESC cultures were evaluated with a commercially available ELISA kit Relative cell proliferation, SRB assay results and caspase levels were analyzed with ANOVA. RESULTS: ESC cultures were maintained up to 30 days. In both patients and controls Cd, but not Pb or Ni increased the relative proliferation in ESC cultures (p<0.05). At 48 h, Cd induced ESC proliferation was higher in patients than in controls (p=0.02). SRB assay results and caspase levels were similar in the two groups. CONCLUSIONS: Established ESC cultures served as stable in-vitro models. Cd induced the proliferation of ESC from women with endometriosis which appears to be independent of reduced apoptosis. Similar effects of Pb and Ni could not be demonstrated in this in vitro model.