Pusat Pengajian Sains Kesihatan - Tesis
Browse
Recent Submissions
- PublicationIn vitro anti-proliferative mechanism of combination therapy with tannic acid and cisplatin against human osteosarcoma cell line U2OS(2024-06)Kasiram, Mohamad Zahid MohdOsteosarcoma is most common primary bone malignancy that affects children and young adults. The survival rate remains low, especially in metastatic cases. Tannic acid (TA), a phenolic compound found in medicinal plants, has shown promising efficacy in enhancing chemotherapeutic drugs against various cancers. Hence, this study aimed to investigate the effect of TA treatment combined with cisplatin on human osteosarcoma cell line (U2OS). The half-maximal inhibitory concentration (IC50) values of TA and its combination with cisplatin against U2OS cells were determined using MTT assay. MTT assay also assessed TA cytotoxicity on normal human foetal osteoblast (hFOB 1.19) cell line. The pharmacological interaction between TA and cisplatin was evaluated using CompuSyn software. The anti-proliferative activity was evaluated by using trypan blue exclusion assay. The morphological and ultramorphological alteration of the U2OS cells were examined using phase contrast inverted microscope and scanning electron microscope (SEM), respectively. The nuclear morphological changes were evaluated by Hoechst 33258 nuclear staining and observed under fluorescence microscope. The percentage of apoptotic cells was measured using flow cytometer after conducting annexin V/propidium iodide (PI) assay. A mechanistic study was conducted by evaluating mRNA expression of mitogen-activated protein kinase (MAPK) and apoptotic pathway using reverse transcriptase quantitative polymerase chain reaction (RT-qPCR). The IC50 values of TA and cisplatin were determined at 4.47 and 16.25 μg/mL, respectively. TA induced no significant inhibitory effect on hFOB 1.19 cells, but potent proliferative effect was indicated. The combination of TA with cisplatin at percentage ratios of 90:10 and 85:15 induced synergistic interaction, while the combination at 75:25 and 50:50 induced antagonistic interaction. The combination at 90:10 showed the highest potency with the lowest IC50 value at 3.56 μg/mL. A significant anti-proliferative effect with prominent morphological and ultramorphological alteration was detected in the combination-treated cells. The cells appeared shrunk, with blebbed membrane and reduced appearance of lamellipodia and filopodia. Additionally, prominent nuclear morphological alteration and highest percentage of apoptotic cells were noted in the combination-treated cells. RT-qPCR analysis indicated the significant upregulation of ERK2, BAX, caspase-9, and caspase-3 and downregulation of JNK1 and BCL2 mRNA expression in the TA- and combination-treated cells. Mechanistically, anti-proliferative and apoptotic effect of TA and its combination with cisplatin on U2OS cells were suggested to be modulated via JNK1 inhibition, ERK2 activation, and intrinsic apoptotic pathways. The findings suggest the potential inclusion of TA in cisplatin-based chemotherapy for osteosarcoma and warrant further investigation
- PublicationEffectiveness of clinical virtual simulation on knowledge retention, self-directed learning ability and learning effect among nursing students in Xi’an Fanyi university, China(2024-09)Han, NanWith the rapid development of information teaching, clinical virtual simulation has been widely used as a new teaching method in nursing teaching. However, in-depth longitudinal research on self-directed learning ability and knowledge retention is lacking. This study aims to identify the effect of clinical virtual simulation on knowledge retention, self-directed learning ability and the learning effect among nursing students. This work is a quasi-experimental study that was conducted in two months, from October to November 2023. Sophomore nursing students from Xi'an Fanyi University were randomly divided into two groups: the control group (n=43), in which the traditional teaching method was used, and an experimental group (n=41), in which a combination of traditional teaching and clinical virtual simulation was employed. The students in the control group attended a theoretical course, followed by clinical practice courses, and received practice guidance in a laboratory. The students in the experimental group attended a theoretical course, learned and practiced the simulation project on a virtual simulation platform, and then attended clinical practice courses and received practice guidance in a laboratory. The knowledge retention of the students was assessed immediately, two weeks, and one month after the intervention using a multiple-choice test. The self-rating scale of the self-directed learning ability questionnaire was used to determine the self-directed learning ability of the students.
- PublicationA standardised fraction 1 (SF1) from clinacanthus nutans attenuates the stemness of cervical cancer stem-like cells via inhibition of notch1 signalling(2024-09)Ismail, FaridahCancer stem cells (CSCs) represent a tiny subset of cancer cells characterised by deregulated self-renewal, aberrant stemness signalling pathways, and a high tumorigenic potential. Mounting evidence indicates that CSCs play a critical role in cancer growth, metastasis, relapse, and resistance to radiotherapy and chemotherapy. Hence, targeting CSCs will provide novel treatments for cancer. Clinacanthus nutans (C. nutans), or locally known as Sabah snake grass (‘daun belalai gajah’), is a well reputed medicinal herb in East Asia that has shown promising anticancer activities in a range of cancer cell types. However, no study has reported its effect on CSCs. Therefore, this study was conducted to determine the antitumour effect of SF1, a semi-purified fraction from C. nutans, on CSCs derived from cervical cancer (CCSCs) and the underlying mechanisms. Bioassay guided fractionation was employed for the isolation of SF1 from C. nutans leaf extract. The SiHa cell line was used for the enrichment of CCSCs by culturing the cells in CSC-conditioned medium (cervospheres). Stemness characterisation of the cervospheres was performed using a sphere formation assay and flow cytometric analysis of the stem-related markers, including CD49f, CK17, Sox2, Nanog, and Oct4. The cervospheres were then subjected to SF1 treatment, and cisplatin was used as a positive control. The antitumour effects of SF1 on cervospheres were evaluated by assessing cell viability, sphere-forming efficiency, and tumorigenic capacity using the OZ blue cell viability kit, sphere formation assay, and in vivo tumorigenicity assay, respectively. The mechanisms by which SF1 eliminated CCSCs were determined by evaluating the selected stemness marker expressions via flow cytometry. Additionally, Notch1 signalling activity, a key regulator for CSC self-renewal and tumorigenicity was examined using the Western blot, quantitative reverse transcriptase PCR (RT-qPCR), and immunohistochemistry staining assays. The results of the study showed that SiHa derived cervospheres exhibited high sphere-forming efficiency, and increased expressions of the stemness markers. In addition, further investigation revealed that these cells possessed higher tumorigenicity in nude mice and increased levels of Notch1 protein and gene expression compared to the parental SiHa monolayer cells. SF1 effectively inhibited the cervosphere viability and stemness phenotypes in vitro and in vivo. SF1 was found to induce a concentration-dependent cytotoxicity in the cells, with a half-maximal inhibitory concentration (IC50) of 17.07 µg/ml. Additionally, treatment of cervospheres with SF1 at the IC50 dose for 72 hours resulted in a significant reduction in the sphere-forming efficiency and a suppression of tumour growth in xenotransplant mice. Besides, SF1 decreased the expression of stemness markers in the cervospheres, primarily CK17 and Sox2 expressions. Nevertheless, Nanog expression remained unaffected. Apart from that, the inhibition of cervosphere stemness properties was accompanied by a marked decrease in the level of Notch1 protein expression. In contrast, increased expression of the Notch1 gene was noted. This implies that SF1 may act by promoting proteasomal degradation of Notch1 protein or disrupting its translation process. In conclusion, SF1 possesses antitumor activity against SiHa derived CSCs, which was achieved through attenuation of their stemness properties and inhibition of the Notch1 signalling. Hence, SF1 may serve as a prospective therapeutic agent for improving cervical cancer management.
- PublicationDevelopment of a new hybrid model and its application in biostatistics(2024-09)Farooqi, Faraz AhmedLinear regression, a fundamental tool in statistical analysis, enables the exploration of relationships between variables. Despite its widespread use, traditional regression analysis encounters challenges when handling qualitative predictive variables (QPV), Multilayer Layer Feedforward Neural Network (MLFFNN), and Fuzzy Linear Regression. There is a significant gap in understanding how to integrate multiple linear regression with other approaches to enhance model accuracy and predictability. This highlights the need for the development of hybrid models. Integrating Multiple Linear Regression (MLR) with advanced techniques, such as fuzzy regression and neural networks, addresses MLR's limitations in handling complex data and improves model accuracy and generalizability. This hybrid approach is crucial for overcoming challenges in biostatistics and enhancing predictive performance. This study utilizes a comprehensive methodology that integrates several techniques, such as transforming QPV, bootstrapping, MLFFNN, and employing fuzzy regression. The utility of the developed methodology is demonstrated using three secondary datasets. All obtained results demonstrate statistical significance, with high accuracy reflected in the R2 values. Additionally, small mean squared errors confirm a close alignment between predicted and actual values. All cases show the method's superiority, offering researchers precise tools for biostatistical inferences and forecasts. Future work will adapt this approach for other regression types and explore its application across various domains.
- PublicationBiospectroscopy with chemometrics analysis of blood for species identification and age estimation(2024-08)Sandran, Durga DeviAccurate species identification and age estimation of bloodstains are indispensable tools in forensic investigations, providing invaluable information that can significantly impact case outcomes. However, existing methods are challenging due to their destructive and strenuous procedures. This thesis explores the effectiveness of biospectroscopic techniques and multivariate chemometrics integration for species and age determination of bloodstains, using samples from eight species: humans, cattle, chicken, deer, duck, fish, goat, and swine. The present study deployed tandem analysis of attenuated total reflection-Fourier transform infrared (ATR-FTIR) and ultraviolet-visible (UV/Vis) spectroscopy, complemented by principal component analysis and linear discriminant analysis (PCA-LDA) to determine bloodstain species. The PCA-LDA models for infrared and visible spectroscopy were built and showed complete differentiation between human and animal spectra. The results demonstrated that the ATR-FTIR spectroscopy significantly outperformed visible spectroscopy in discriminating human and animal blood. With a classification accuracy of 98.3%, the infrared PCA-LDA model effectively distinguished between various species, including a perfect classification for humans, chickens, cattle, ducks, and fish. For in-situ bloodstain age analysis, human and animal blood spots were prepared and stored under two conditions: indoors and outdoors. The blood spots were deposited on ten porous and non-porous substrates over one year to simulate a crime scene. Utilising ATR-FTIR spectroscopy, two major blood protein bands (Amides I and II) can be successfully detected in fresh and aged blood spectra for up to one year. A total of 160 partial least squares regression (PLSR) models were developed, with superior predictive performance observed for outdoor bloodstains (RMSE: ~0.29-2.42; R2: ~0.56-0.99) compared to indoor ones (RMSE: ~0.51-3.28; R2: ~0.20-0.98). Lower predictive Root Mean Squared Error (RMSE) and high R² scores for bloodstains on all ten substrates, irrespective of species, enhanced this research's practicality. These models were further applied to create partial least squares-discriminant analysis (PLS-DA) models, demonstrating outstanding categorisation ability up to ~99% (indoors) and ~98% (outdoors) for aged blood spots on porous and non-porous surfaces. Both validation results showed prominent potential and statistically reliable discrimination for estimating the bloodstain age on various substrates, notably for outdoor and longer ageing terms. In summary, this research proves that integrating ATR-FTIR spectroscopy with multivariate chemometrics provides a non-invasive, conclusive and rapid strategy for determining the species and age of bloodstains in forensic investigations with promising practical applications in real cases benefiting the forensic and law enforcement communities.