PURSE 2004
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- ItemChronic Renal Failure in the Medawachchiya-Padaviya Areas: A Geo-Environmental Study(University of Peradeniya, 2004-11-10) Ileperuma, O. A.; Dharmagunawardhane, H. A.; Herath, K. R. P. K.While the etiology of the chronic renal failure in the Medawachchiya-Padaviya areas still remains a mystery, some results on the geo-environmental factors of the region reveal some significant findings. A chance discovery made during field studies was that people exclusively use aluminium utensils and that holes were observed in these utensils after continuous use. Water used by these people mostly come from dug wells and they generally have high fluoride content in the range of 1.00-4.00 ppm with a median of around 1.3 ppm. Fluoridation of drinking water is in the midst of a controversy owing to studies, which have shown a direct link between aluminium and fluoride to Alzheimer like symptoms in experimental animals. A cocktail of aluminium and fluoride laced water given to rats showed that the animals develop Alzheimer like symptoms but their premature deaths were attributed to kidney failure. The ability of the aluminofluoride complexes to penetrate the blood-brain barrier has been forwarded as a possible explanation for this observation. The present study aims to establish any relationship between fluoride, aluminium utensils and chronic renal failure. In this study pieces of aluminium from a used aluminium pot were treated with fluoride water containing at different levels of 1.0-4.0 ppm. After two days of standing at room temperature, the amount of aluminium leached was measured by a colorimetric technique (aluminon reagent) to determine uncomplexed aluminium and atomic absorption spectrophotometry to determine total aluminium. The amount of aluminium leached out in the absence of fluoride was 0.43 ppm while in 1 ppm fluoride medium the free aluminium observed was 3.00 ppm where the total aluminium was 11.87 ppm. Surprisingly, the amount of aluminium leached was lower at hgher concentrations of aluminium. This observation is similar to the results from studies on rats where lower concentrations of aluminum fluoride produced more toxic effects than at higher concentrations. In the presence of an acidic medium, using 2g/l of tartaric acid and I ppm fluoride, the aluminium leached was around 56 ppm which is a five-fold increase in the dissolution of aluminium. This experiment was performed owing to the widespread use of acidic ingredients like tomatoes, tamarind, vinegar and limejuice during cooking in aluminium pots. Aluminium leaching under high fluoride stress and acidic spices results in the formation of aluminofluoride complexes such as AlF63., which are soluble and penetrates the blood brain barrier. This stable AlF₆³⁻. complex has an overall formation constant of 6.9 x 10¹⁹ . The observation of both dental and skeletal fluorosis amongst the affected patients gives further credence to the hypothesis that aluminium and fluoride in combination could be a possible reason for the occurrence of chronic renal failure in areas with high fluoride content in water.
- ItemCIM System Expansion With Minimal Changes to Installed Source Code(University of Peradeniya, 2004-11-10) Dewasurendra, S. D.The need to upgrade the CIM (Computer Integrated Manufacturing) Systems to provide increased capability in the face of rapid change in product/process specifications has been identified: integration of mechatronic devices such as CNC machines, robot manipulators, automatic assembly systems is a major effort in manufacturing and automation systems, particularly in the face of an increasing demand for these systems to be agile. Agility implies the capability of responding to production changes, both in volume and variety, rapidly, effectively and reliably with low cost. Due to differences in user interfaces to these equipment significant recoding is often needed in response to changes required in production systems. The code that can run into thick volumes has to be verified before installation. Hence, modifying the installed control software to facilitate extension or modification of the system to suit current needs is not straight forward. The present problem is to provide a suitable framework which would facilitate such extension and improvement. In the proposed approach, we wrap already installed software modules in CGI script thus making it possible for them to cooperate with new control modules. The system control is designed and specified using the Universal Modelling Language (UML). In order to provide re-configurability we define port structures between each pair of communicating classes. Verification is localised by having to verify a module using only the information contained in the ports to which it is connected.
- ItemClinical Aspects of Oral Lichen Planus in a Group of Sri Lankan Patients(University of Peradeniya, 2004-11-10) Ariyawardana, A.; Seneviratne, C. J.; Sitheeque, M. A. M.; Ranasinghe, A. W.The aim of this study was to determine clinical characteristics of oral lichen planus (OLP) in a group of Sri Lankan patients who attended the Dental Hospital for treatment. A total of 104 patients with oral lichen planus who attended the Oral Medicine clinic, Faculty of Dental Sciences, during the period from January 2001 to December 2003 were included in the study. Information pertaining to demographic data, duration of oral lesions and existence of skin lesions were obtained and site and types of the lesions were recorded. Patients with the history of current usage of drugs known to cause lichenoid reactions and with amalgam fillings associated with lesions were excluded from the study. Incisional biopsies were taken from lesions of all the patients in order to confirm the diagnosis. The mean age of the study population at the time of presentation was 45 years and the highest number of cases was found in the age group of 45-55 years (χ²=20.26, df=5, P=O.OO1). Females outnumbered males (1.5: 1). The mean period of experience of the disease before seeking treatment was 4.4 months. 16.3% (n=17) had no symptoms and the rest had feelings of roughness, burning sensation at meal times and spontaneous mucosal burning. There was no gender difference with respect to symptoms (χ²=3.323, df=3, P=O.344). Fourteen patients (13.5%) had shown skin lesions. Six clinical types were identified namely reticular (58.7%), papular (1.9%), plaque like (3.8%), atrophic (2.9%), ulcerative or erosive (6.7%) and lesions with combination of different morphological variants (26%). There was no gender difference with regards to the different clinical types (χ²=5.769, df=5, P=O.329). All patients with atrophic and erosive/ulcerative types had burning sensation as the main symptom. Forty-eight out of 61 patients (78.6%) with reticular type and 19 patients out of 27 (70.3%) with mixed types had burning sensation at meal times. Common sites of affliction were left buccal mucosa (76.9%), right buccal mucosa (75%), dorsum of the tongue (16.3%), lower vermilion border (10.6%) and gingiva (7.7%). The most frequent mucosal combination was the left and right buccal mucosa affecting 66 patients (63.5%). Eighty-seven patients (83.6%) needed therapeutic management and the mainstay of treatment was corticosteroids. Only eight patients (7.7%) needed the use of systemic steroids to control their symptoms. The age and sex distribution of the present cohort resembles that of the other studies on OLP patients. Reticular type was the commonest in the present study and similar results were found in other studies. Buccal mucosa was the commonest site of affliction. There were no cases with evidence of dysplasia or transformed to malignancy. Furthermore, it was not possible to comment on the treatment outcome or the malignant transformation at this stage of the study as the present group of patients is on follow up.
- ItemChemistry of Two Leprarioid Lichens from Sri Lanka(University of Peradeniya, 2004-11-10) Kathiragamanathar, S.; Karunaratne, V.; Kumar, V.We reported the two species of lichens 𝘓𝘦𝘱𝘳𝘰𝘭𝘰𝘮𝘢 𝘴𝘪𝘱𝘮𝘢𝘯𝘪𝘢𝘯𝘶𝘮 and 𝘓𝘦𝘱𝘳𝘢𝘳𝘪𝘢 𝘢𝘵𝘳𝘰𝘵𝘰𝘮𝘦𝘯𝘵𝘰𝘴𝘢 from Sri Lanka in 2000. The former which was collected from Beragala, was previously reported from South Africa, Colombia and Brazil while the latter, collected from Ramboda, is a new species. The compounds, atranorin 1, β-sitosterol 2, (+)-usnic acid 3, zeorin 4 and a C₋₄₃ fatty acid ester 5 have been isolated previously from the hexane and dichloromethane extracts of 𝘓 𝘴𝘪𝘱𝘮𝘢𝘯𝘪𝘢𝘯𝘶𝘮. In the present study the methanol extract and the lichen powder of this lichen yielded compounds 1-5 in addition to glyceryl trilinolate 6, 3, 6-dimethyl-2-hydroxy-4- methoxybenzoic acid 7 and a triterpenoid 3β-acetoxyfem-9(11)-ene 8. Chromatography of the lichen powder of 𝘓 𝘢𝘵𝘳𝘰𝘵𝘰𝘮𝘦𝘯𝘵𝘰𝘴𝘢 led to the isolation of five compounds, including compounds 1-4 along with methyl-β-orcinolcarboxylate 9. All compounds were characterized by the physical data (mp, TLC and co-TLC) and spectroscopic methods (UV, ¹H NMR, ¹³C NMR, ²D NMR and MS) [The abstract also includes scientific formulas and symbols to represent key concepts and findings].
- ItemChemical Constituents of 𝘈𝘳𝘵𝘰𝘤𝘢𝘳𝘱𝘶𝘴 𝘈𝘭𝘵𝘪𝘭𝘪𝘴(University of Peradeniya Sri Lanka, 2004-11-10) Jayasinghe, U. L. B.; Amarasinghe, N. R.In a continuation of our studies on search for biologically active compounds from Sri Lankan plants the present study was carried out on the fruits of 𝘈𝘳𝘵𝘰𝘤𝘢𝘳𝘱𝘶𝘴 𝘈𝘭𝘵𝘪𝘭𝘪𝘴 (Park.) Fosb .. 𝘈. 𝘢𝘭𝘵𝘪𝘭𝘪𝘴 of the family Moraceae is a tree of moderate size, commonly known as bread fruit growing in tropical countries[The abstract also includes scientific formulas and symbols to represent key concepts and findings]. The dried powdered fruits of 𝘈𝘳𝘵𝘰𝘤𝘢𝘳𝘱𝘶𝘴 𝘢𝘭𝘵𝘪𝘭𝘪𝘴 were defatted with n-hexane and extracted with ethyl acetate and methanol at room temperature. Preliminary investigation indicated the presence of antifungal active compounds against 𝘊𝘭𝘢𝘥𝘰𝘴𝘱𝘰𝘳𝘪𝘶𝘮 𝘤𝘭𝘢𝘥𝘰𝘴𝘱𝘰𝘳𝘪𝘰𝘪𝘥𝘦𝘴 in both ethyl acetate and methanol extracts in the same Rf region by TLC bioautography method. In order to isolate antifungal active compounds, both ethyl acetate and methanol extracts were combined and separated by a combination of chromatographies over column of silica gel, Sephadex LH-20, reverse phase silica gel and reverse phase HPLC to give seven compounds. Four of them were identified as (𝘌)-4-(3-methyl-E-but-1-enyl)-3,5,2', 4'- tetrahydroxystilbene (1), (𝘌)-3,5,2',4' -tetrahydroxystilbene (2), 2-(2,4-dihydroxyphenyl)- 5,7-dihydroxychroman-4-one (3) and 2-(3,5-dihydroxyphenyl) benzofuran-4, 6-diol (4). Structure elucidation of isolates was based on the detailed analysis of ¹HNMR, ¹³CNMR, MS and direct comparison of the reported data. All these compounds showed radical scavenging properties towards 2,2' -diphenyl-I-picrylhydrazyl (DPPH) radical by TLC bio-autography method. Structure elucidation of the other three compounds and determination of antioxidant activity (IC₅₀) and antifungal activity (MIC) of isolates are in progress.