Conferences and Symposia
Permanent URI for this communityhttp://repository.kln.ac.lk/handle/123456789/10376
Conference papers presented at Conferences and Symposia organized by the Faculty of Medicine are collected under this subcommunity
Browse
6 results
Search Results
Item Awareness on dengue and solid waste management among selected school students in Gampaha District of Sri Lanka(Moleclar Medicine Unit, Faculty of Medicine, University of Kelaniya, Sri Lanka, 2015) Radhika, N.M.L.; Gunathilaka, P.A.D.H.N.; Abeyewickreme, W.; Kasturiratne, K.T.A.A.BACKGROUND: Community mobilization is often respected as a powerful tool in ensuring the effective controlling of dengue via promoting effective and sustainable dengue vector control strategies. The current study attempts to investigate the level of awareness on dengue and solid waste management, among selected school students in Gampaha District which is the second highest dengue reported district in Sri Lanka. METHODOLOGY: Awareness programmes on dengue (transmission, vector ecology and preventive measures) and solid waste management were conducted in 10 schools belong to Kelaniya Medical Officer of Health (MOH) area selecting a minimum group of 200 students from each school within the age of 13 - 15 years. Tools such audio-visual presentations, leaflets and videos were used for the awareness programmes. A questionnaire was given to each student prior to the awareness and after the awareness programs as pre and post evaluations respectively in order to assess the general awareness on dengue and solid waste management before and after the awareness programme. One-Way ANOVA, paired t-test and multiple regression techniques were utilized in evaluation of the degree of awareness and key factors affecting the level of awareness, prior and after the conducting the awareness programmes. RESULTS: The degree of initial awareness on dengue and solid waste management of the target school community was recognized to be significantly characterized by the grade of the students and the Education Zonal Category [EZU] (into which their school belongs to) in accordance with One-Way ANOVA (p < 0.05). A significant increment in post awareness of the target school community was recognized due to the conducting of awareness programmes in accordance with the statistics of paired t-test (p < 0.05). Furthermore, based on the multiple linear regression modelling, the post awareness was significantly influenced by the grade of the students and the initial awareness (p < 0.05), regardless of the EZU (p > 0.05). CONCLUSIONS: The awareness of school students on dengue and solid waste management is significantly affected by the grade of the students and EZCs. Awareness programmes are an effective media of raising the awareness of school communities on dengue and solid waste management, while motivating them to actively contribute for the controlling of dengue, via establishing a strong inter sectorial network among schools and other relevant institutions within the Gampaha District.Item Emerging spatio-temporal trends of dengue incidence in Colombo and Kandy Districts, Sri Lanka(Moleclar Medicine Unit, Faculty of Medicine, University of Kelaniya, Sri Lanka, 2015) Udayanga, N.W.B.A.L.; Gunathilaka, P.A.D.H.N.; Iqbal, M.C.M.; Kusumawathie, P.H.D.; Abeyewickreme, W.BACKGROUND: Dengue has become a prominent challenge to the health sector in Sri Lanka. Prior identification/prediction of possible risk areas with high susceptibility to dengue, could be of major importance in ensuring the effective regulation of dengue epidemics. Therefore, the current study attempts to investigate the spatio-temporal trends in dengue incidence and priority risk factors that characterize dengue epidemics, aiming to stratify the Colombo and Kandy Districts into high, moderate and low risk areas via development of dengue risk maps by devising a statistical and geo-informatics based approach. METHODOLOGY: Socio-economic data of dengue patients and healthy volunteers in selected high risk MOH areas of Colombo (5) and Kandy (5) Districts were obtained through an interviewer administrated questionnaire. Previously reported dengue cases from 2009 to 2014 in each MOH were acquired. The spatio-temporal trends in dengue incidence of studied MOHs, were investigated at the Grama Niladhari Division (GND) level by using Arc GIS (version 10.2). The impacts of gender and age of the community on the disease prevalence were investigated by using normal Chi square test and Paired-Chi square test in SPSS (version 23). RESULTS: At present, 95% and 81% of the overall socio-economic surveillance has been completed in Kandy and Colombo Districts, respectively. Spatial maps on disease outbreaks have been developed for Akurana, Doluwa, Gampola, Gangawatakorale, Kandy Municipal Council (KMC), Kundasale and Poojapitiya MOH areas. According to results of the Paired-Chi square test, the emergence of dengue outbreaks indicated a significantly declining trend in recorded dengue cases in most of the GNDs within the studied MOHs, during the recent years. The Percentage Infected Male:Female Ratio (PIMFR) remained significantly altered throughout the period of study (p=0.001<0.05 at 95% of significance). Within the studied MOHs, males tend to indicate relatively high susceptibility for dengue infection than females (with 58.6: 41.5 of average PIMFR). The age group of 11 – 20 and 21 – 30 years were identified as with highest vulnerability to dengue, while the age > 61 years indicated the least vulnerability in all the MOHs. According to the Paired-Chi square test, the vulnerability of age groups was found to shift significantly throughout the study period [>Χ2 (7, 0.95) = 14.067]. CONCLUSIONS: The KMC and Gampola MOHs indicate relatively high susceptibility to dengue within the district of Kandy. Within all the studied MOHs, males tend to indicate relatively high susceptibility to dengue. Age groups of 11 - 20 and 21 – 30 denote relatively higher vulnerability to dengue, while age group of > 61 emerge as the least vulnerable group for the infection of dengue in the studied MOHs.Item Encapsulation of essential oil blend in β-CD nanoparticles as a repellent for slow release(Moleclar Medicine Unit, Faculty of Medicine, University of Kelaniya, Sri Lanka, 2015) Jayaweera, V.; Eliyapura, A.; Gunasekara, D.; Weerasinghe, L.; Gunathilaka, P.A.D.H.N.; Abeyewickreme, W.; Karunaratne, V.BACKGROUND: Malaria, dengue, and other tropical diseases carried by arthropods such as mosquitoes, ticks and fleas have greatly affected life expectancy, infant mortality, quality of life and work productivity. Essential oils such as citronella, lemon eucalyptus, peppermint, lemon, eucalyptus, lemongrass, geranium, and lavender are known for their mosquito repellency. Due to high volatility of essential oils, these are needed to be reapplied to the skin every 30–60 minutes. Therefore, development of a long lasting mosquito repellent is needed for effective repellent activity. The aim of this experiment is to develop a new blend which encompasses citronella, lemon eucalyptus, lemon and lavender. This oil blend is encapsulated using β-Cyclodextrin (β-CD) to decrease the volatility of the oil blend and increases the long-lasting repellency. METHODS: Citronella, lemon eucalyptus, lemon and lavender were obtained in 15% v/v, 15% v/v, 1% v/v and 1% v/v respectively for a total volume of 100 ml. These oils were mixed with 0.2% w/v of β-Cyclodextrin for encapsulation. The blend was sonicated for 20 min and dissolved in ethanol. This final encapsulated mixture was subjected to bioassays using 110 adult Aedes albopictus mosquitoes against the control. Sitting and biting mosquito behavior patterns were studied against the releasing time. RESULTS: The bioassay results indicated that the encapsulated repellent product is effective against the mosquitos up to 6 hours with zero sitting and biting comparatively to the control. In the 7th hour showed single mosquito sitting with zero biting. CONCLUSION: The encapsulated repellent is effective against the Ae, albopictus mosquitoes for 6 hour time period. Therefore, it is a long-lasting repellent that protect against dengue fever caused by mosquitoes.Item Synthesis of Fe2O3 nanoparticles for the development of a rapid diagnostic test kit for dengue detection(Moleclar Medicine Unit, Faculty of Medicine, University of Kelaniya, Sri Lanka, 2015) Jayarathna, I.P.L.; Gunathilaka, P.A.D.H.N.; Athapaththu, A.M.M.H.; Abeyewickreme, W.BACKGROUND: Hybrid nanoparticles have great potential for biotechnological and biomedical applications. It was recently proposed that biopolymer/co-shell nano-materials could be easily obtained by adapting traditional routes used in pharmaceutical science to design drug delivery system. Most of the case, super-paramagnetic nanoparticles of iron oxides, magnetite (Fe3O4) and maghemite (ᵧ -Fe2O3) have been employed and these interesting magnetic properties are due to finite-size effects and high surface/volume ratio. METHOD: Iron oxide was synthesized by using modified co-precipitation method and resulting particles were characterized using X-ray diffraction (XRD), Transmission Electron Microscopy (TEM) and Diffused Reflectance Fourier Transform-Infrared Spectroscopy (DRIFT-IR). RESULTS: The XRD pattern matches well that of ᵧ -Fe2O3. Six characteristic peaks for ᵧ -Fe2O3 (2θ = 31.7°, 36.7°, 41.1°, 53.4°, 57.0° and 62.6°) marked by their Miller indices [(220), (311), (400), (422), (511) and (440)] were observed for sample. The TEM images reveal that the particles are in 5 – 20 nm range, and well fitted with spaniel cubic structure, but when particles are dry it prefer to agglomerate with neighboring particles to reduce their surface charges. The spectrum of ᵧ -Fe2O3 nanoparticles shows a characteristic broad band at 3410 cm-1 is due to the stretching vibration of H2O molecules. The band corresponding to the bending vibrations of H2O molecules is positioned at 1633 cm-1. Two intense IR bands at 627 and 451 cm-1 are typical for ferrihydrite or ᵧ -Fe2O3 nanoparticles. The spectrum of this sample showed the presence of carbonate groups on the basis of IR bands at 1508, 1340 and 1069 cm-1. The presence of carbonate groups is due to the adsorption of atmospheric carbon dioxide by ᵧ -Fe2O3 nanoparticles. The bands of Fe–O stretching vibrations of ᵧ -Fe2O3 appeared at 627 and 451 cm-1 and the bands at 892 and 796 cm-1 can be assigned to Fe-OH···H bending vibrations. CONCLUSION: Magnetic ᵧ -Fe2O3 nanoparticles were synthesized by the co-precipitation method and this work confirmed that magnetic ᵧ -Fe2O3 nanoparticles are in nano-scale and well matches with spaniel cubic structureItem Designing of immunogenic peptides from Dengue Virus NS1 region for production of monoclonal antibodies as diagnostic intermediates(Molecular Medicine Unit, Faculty of Medicine, University of Kelaniya, Sri Lanka, 2015) Munasinghe, M.M.E.; Chandrasekharan, N.V.; Korbakis, D.; Soosaipillai, A.; Diamandis, E.P.; Athapaththu, A.M.M.H.; Gunathilaka, P.A.D.H.N.; Abeyewickreme, W.BACKGROUND: Small peptide antigens have become an essential tool for antibody production in the recent life science research applications. The immunogenicity of peptide antigens is a critical factor to induce the immune response in order to produce desired antibodies. METHODS: In the current study, we have previously determined four Dengue (DEN) serotype specific peptides, containing 28 Amino Acid (AA) residues were re-designed. The peptides were re-designed considering many factors, for instance, sequence of the Sri Lankan isolates, abundance of Cysteine residues, solubility and the length of the peptide, carrier protein to be used and several other factors such as the N-terminal and C- terminal AAs and multiple AA residues. The peptide sequences were analysed using Antigen Profiler Peptide Tool (Thermo-scientific), Peptide Property Calculator (Genscript) and Swiss-Model (Biozentrum). RESULTS: The protein sequence of the peptides were changed according to the Sri Lankan isolates (AEB98757.1, ACS32038.1, AHG23239.1 and AHN50410.1). Oxidation of Cysteine residues results in significant conformational changes. Replacement of Cysteine with Serine prevents such oxidation reactions and it often retains full biological activity. Generally, peptides with a high number of hydrophobic AA (>50%) may result insoluble peptides. Similarly, to obtain a soluble peptide, it is important to contain at least one charged AA in every five AAs. Hence, the number of hydrophobic residues in the peptides were maintained below 50% and ensured that one out of every five amino acids is charged. The length of the peptide is an important factor as long peptide increases immunogenicity, but also increases the chance for cross-reactivity while a short peptide improves the specificity, but may not be immunogenic. In order to obtain both highly conserved and variable regions among four serotypes, the peptide length was determined as 29 residues. A terminal Cysteine was added to allow peptide conjugation with carrier protein. Keyhole Limpet Hemocyanin was selected as the carrier protein due to its higher immunogenicity. N-terminal Glutamine or Aspargine and C-terminal Proline or Glycine in the sequences were avoided. Finally, the peptides sequences were determined as: DEN1; CPESSDDQRA WNIWEVEDYGFGIFTTNIW,DEN2; CAESPN TNRA WNSLEVEDYGFGVFTTNIW, DEN3;CPESPSASRAWNVWEVEDYGFGVFTTNIW and .DEN4;CSESPNERRAWNSLEVEDYGFGMFTTNIW. CONCLUSION: These peptides have a high potential to be used as peptide antigens for Monoclonal Antibody production.Item Laboratory studies on larvivorous potential of five fish species against Aedes ageypti (Linnaeus) and Ae. albopictus (Skuse)(Molecular Medicine Unit, Faculty of Medicine, University of Kelaniya, Sri Lanka, 2015) Kusumawathie, P.H.D.; Jayasooriya, G.A.J.S.K.; Gunathilaka, P.A.D.H.N.; Hapugoda, M.; Abeyewickreme, W.BACKGROUND: The dengue vectors, namely, Aedes aegypti (Linnaeus) and Ae. albopictus (Skuse) are container breeders, thus, container management is a key element for elimination of vector breeding sites. Use of predator fish is a potential tool for dengue vector control in some container habitats. However, in order to select suitable fish species, larvivorous potential of different fish species needs to be determined. Therefore, the objective of the study was to determine the larvivorous potential of some fresh water fish species against the dengue vectors. METHODOLOGY: Five fish species, namely: Poecilia reticulata, Aplocheilus dayi, Oreochromis niloticus, Rasbora daniconius and Puntius bimaculatus were collected from their natural breeding places during the field surveillance conducted from January-October, 2015. Each fish species was placed in separate fish stock cement tanks at the Regional Office of the Anti- Malaria Campaign in Kandy until they were used for the study. In order to determine the larvivorous potential of the fish, each species was placed in separate enamel trays containing de-chlorinated water and allowed to acclimatize for 30 minutes. A batch of 25 Ae. aegypti and Ae. albopictus larvae was introduced to each tray superlatively and the number of larvae remaining was counted after 24 hours of observation period. Once all the batch of larvae consumes by the fish species, another batch of 25 larvae from respective species was introduced during the observation period. The whole experiment was repeated for 6 times. RESULTS: The mean values of Ae. aegypti larvae consumed by one fish of O. niloticus, P. reticulata, A. dayi, R. daniconius and P. bimaculatus were 97.6, 66.9, 49.3, 62.5 and 47.5 respectively while, one fish of O. niloticus, P. reticulata, A. dayi, R. daniconius and P. bimaculatus consumed 98.4, 62.3, 51.2, 62.5 and 45.4 of mean Ae. albopictus larvae respectively. CONCLUSIONS: All five fish species showed larvivorous activity. However, O. niloticus showed the highest larvivorous potential followed by P. reticulata. Therefore, these two fish species may be considered as a supplementary method to control immature stages of dengue vectors.