https://ir.kdu.ac.lk/handle/345/8352 Wed, 08 Apr 2026 13:41:36 GMT 2026-04-08T13:41:36Z https://ir.kdu.ac.lk/handle/345/8459 Is Discrete Incremental Meta Docking (DIMD) the Key to Success in Molecular Docking-Based Drug Discovery? A Comparison of the Results of the Novel Vinca Derivative VADRPA01 Halahakoon, HMAJ Determining the crystal structure of vinca-site inhibitors in complex with the tubulin heterodimer is crucial for understanding binding modes and guiding the design of novel microtubule inhibitors targeting the vinca binding domain. However, the lack of a universally validated methodology for dataset preparation and protein-ligand validation complicates the comparison and reproduction of docking results. The present study addresses this issue by evaluating the molecular docking results using the Discrete Incremental Meta Docking (DIMD) technique. The DIMD method facilitated the identification of the best docking pose for a novel vinblastine derivative, VADRPA01, with a binding affinity of -15.416 kcal/mol (a 47.74% enhancement) and an inhibition constant of 0.0051 nM, compared to its best rigid docking pose (-10.8 kcal/mol) obtained through a general docking procedure. Crystallized water at the vinca binding site of the native vinblastine-5J2T (tubulin) complex was found to stabilize VADRPA01 within the binding domain. Molecular dynamics studies revealed that flexible amino acid residues in the receptor binding pocket contributed to the reduction of binding energy by forming hydrogen bonds with PHE351, LYS336, ALA333, and ASN329 on the alpha chain of the tubulin heterodimer. Additionally, the calculated protein-ligand binding affinities using MMPB(GB)SA indicated a total binding energy of -27.15 kcal/mol, confirming the stability of the 5J2T-VADRPA01 complex. The optimal docking pose of VADRPA01, derived from the hydrated flexible docking procedure, showed an RMSD of 1.5020 Å compared to the native vinblastine-5J2T complex. These advancements in the docking procedure have identified the most favourable docking pose for VADRPA01, supporting further drug discovery studies of vinca derivatives. Thu, 26 Sep 2024 00:00:00 GMT https://ir.kdu.ac.lk/handle/345/8459 2024-09-26T00:00:00Z https://ir.kdu.ac.lk/handle/345/8458 Evaluation of Inter-fractional Geometric and Dosimetric Variations in Gynaecology Brachytherapy based on C-arm X-ray Images in Carcinoma of Cervix at Apeksha Hospital Maharagama Hapugoda, SP; Dharmasiri, HKA; Tudugala, R; Balawardane, J Treatment reproducibility is a key aspect of accurate radiotherapy to achieve better target coverage and normal organ sparing. Uniform protocols for these procedures should be maintained to achieve this. Partial coverage of the target leads to recurrence of the tumour and over exposure of Organs at risk (OAR) results in severe complications. Therefore, close consideration of the doses and volumes during the planning process and consideration of inter-fractional treatment variations are essential to minimize such complications. The aim of this study is to assess the relationship among inter-fractional technical, geometrical, and dosimetric variations and to determine the causes for these variations in gynaecology brachytherapy for carcinoma of cervix. A total of 211 subjects who have completed High Dose Rate (HDR) brachytherapy between January 2022 and January 2023 at Apeksha Hospital Maharagama were selected for this study. Data were obtained from the logbook and daily dose profile which is available in the HDRplus 3.0 software. The data included treated volumes, delivered doses, number of activated dwell points, applicator distances and number of packs utilized. The data were further analysed using IBM SPSS statistics software (version 28.0). According to the results, correlations between treated volume variations and applicator variations are mostly significant, and the correlation with tandem is highly significant. Correlations between bladder dose variations and applicator variations are mostly insignificant while the correlations between rectal dose variations and applicator variations are totally insignificant. The relationship between dosimetric variations of both the bladder and the rectum are highly significant with the variations in the number of gauze packs utilized inter-fractionally. In conclusion, geometric variations were predominantly affected by applicator variations of the tandem while bladder and rectal doses were less affected by applicator variations and were mostly affected by gauze packs. Thu, 26 Sep 2024 00:00:00 GMT https://ir.kdu.ac.lk/handle/345/8458 2024-09-26T00:00:00Z https://ir.kdu.ac.lk/handle/345/8456 Evaluation of the Level of Knowledge and Awareness of Radiation Protection among Radiation Therapists in Sri Lanka Anaas, MRM; Nethmini, WWT; Dharmasiri, HKA; Tudugala, R Radiation therapists are exposed to ionizing radiation during treatments making it essential for them to understand and apply radiation protection principles to safeguard their health. Inadequate training or knowledge can lead to unsafe practices and increased exposure risks. This study aims to assess knowledge and awareness on radiation protection among radiation therapists in Sri Lanka, identify existing knowledge gaps, and guide targeted training to enhance safety protocols and improve care quality. A descriptive cross-sectional study was conducted to analyze characteristics and factors associated with radiation therapists. Data were summarized by frequency and in terms of mean and standard deviation, and normality was assessed using the Kolmogorov-Smirnov test. Nonparametric tests, namely Spearman’s correlation and Kruskal-Wallis H-test were used for statistical analysis since the data did not follow normal distribution. The criterion for statistical significance was set at a p-value less than 0.05. The study included a sample size of 91, from which 52 responses were successfully collected. The Kruskal-Wallis test showed significant differences in general radiation protection knowledge (p = 0.03) and the total score of knowledge and awareness of radiation protection based on educational qualifications (p =0.05). However, no significant differences were found in the mean rank scores of radiation protection knowledge related to working experience (p > 0.05). This study verified that the overall score of knowledge and awareness on radiation protection among radiation therapists in Sri Lanka was quite satisfactory. Thu, 26 Sep 2024 00:00:00 GMT https://ir.kdu.ac.lk/handle/345/8456 2024-09-26T00:00:00Z