Pusat Pengajian Sains Perubatan - Tesis

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Microvascular Endothelial Function In Obesity; And The Effect Of Pharmacological Intervention With Orlistat And Sibutramine On Microvascular Endothelial Function And Selected Cardiovascular Risk Markers
(2012)
Al-Tahami, Belqes Abdullah Mohammad
Obesity increases the risk of a variety of medical problems and cardiovascular diseases. Endothelial dysfunctionis one of the earliest vascular changes that occur in the pathogenesis.. Of cardiovascular diseases. This phd work is composed of three studies. The first study aimed to optimize a technique used to assess microvascular endothelial function, using laser doppler fluximetry (ldf) and the process of iontophoresis. Ldf measures skin perfusion, while iontophoresis is a non-invasive method of introducing charged substances across skin by means of a small electric current to evaluate both endotheliumdependent and endothelium independent vasodilatation. Firstly, the effect of sodium chloride used as a vehicle to dilute the iontophoresis drugs acetylcholine (ach) and sodium nitroprusside (snp) on non-specific vasodilatation was assessed. Secondly, to determine the number of electrical pulses needed to reach the maximum response during iontophoresis of ach and snp using low current strength. Thirdly, the reproducibility of different parameters during iontophoresis of ach and snp) were also determined. The initial iontophoresis protocol used consisted of 7 electrical pulses of2 minutes each separated by l minute current free interval.
Laparoscopic cholecystectomy; intraoperative cholangiography versus no intraoperative cholangiography. a multi center randomized control trial
(2019)
Zainudin, Nur Zawani
Introduction: Intraoperative cholangiography (IOC) is not something new in the world of laparoscopic cholecystectomy (LC). However it is still not a favorite method to be applied as a routine procedure in LC. Objectives: To determine the feasibility and safety of performing IOC during LC, to detect the incidence of undiagnosed pre-operative bile duct stone and to identify whether IOC can prevent bile duct injury. Method: Multi-center, double blinded randomize controlled trial done from 2016-2018. Total of 308 patients recruited and divided into 2 arms; with IOC and without IOC. Exclusion criteria includes in situ biliary stent placement, history of multiple laparotomies, performed. Out of 308 patients, 154 patients were assigned to IOC group and 154 patients were assigned to no IOC group. Results: There was a statistically significant difference of mean operation time between the group with IOC and no IOC (mean operation time for IOC group was 66.0 minutes (SD ±28.20) compared to no IOC group 55.6 minutes (SD±23.15), t statistics (df) = 306 (6.78), p-value <0.001). The successful rates for IOC was 98.1%. From 12 cases with presence of filling defects detected during IOC, 4 cases were confirmed CBD stones. Two were confirmed after conversion to CBDE and the other 2 cases were confirmed during ERCP performed. There was only 1 case of bile duct injury noted during IOC. No patients developed allergic reaction to contrast media and the post-operative complications were similar in both groups. Conclusion: IOC is a useful tool to delineate anatomy of bile duct during surgery. It also can easily been done by any surgeon with lots of practices and a proper guidance. Its use may be beneficial in selected cases.
Screening of the anti-proliferative effects of baicalein and carbon nanodot combination on hela cancer cells
(2025-01)
Partheeban, Yugaashini
This study identifies the anti-proliferative effects of a novel combination therapy using baicalein, a flavonoid, and carbon nanodots (CDs) on HeLa cervical cancer cells. Baicalein, known for its potent anti-cancer properties, has shown limitations in clinical applications due to low bioavailability. Carbon nanodots, with their excellent biocompatibility, solubility, and drug delivery potential, were used as a carrier to enhance the therapeutic efficacy of baicalein. The study evaluated the anti-proliferative effects of the baicalein-carbon nanodot (Bai-CDs) combination in comparison to standalone treatments of baicalein, CDs, and cisplatin on HeLa cells using the MTT assay. Results demonstrated that the combination therapy significantly inhibited cell proliferation in a dose-dependent manner with the IC50 69.85 ± 4.145μg/ml and p-value less than 0.05. These findings highlight the potential of the Bai-CDs combination as a new therapeutic strategy for cervical cancer, providing enhanced bioavailability and targeted anti-cancer effects while minimizing adverse outcomes associated with conventional chemotherapy
Anticancer effects of apis cerana and heterotrigona itama honeys on temozolomide-resistant glioblastoma cells
(2025-01)
Hui, You Ying
Glioblastoma is characterized by high aggressiveness and poor prognosis with median survival rate of less than 15 months. Due to the complexity of surgery to remove whole tumour and rapid development of chemoresistance towards temozolomide (TMZ), apitherapy using honey emerges as potential alternative treatment for glioblastoma due to its rich phenolic compounds with high antioxidant properties. However, the difference between Apis cerana honey and Heterotrigona itama honey for anti-glioblastoma effects has not been extensively studied. In this study, the phytochemical composition of A. cerana and H. itama honey were compared using phytochemical screening test and fourier transform infrared spectroscopy (FTIR) analysis. Their antioxidant capabilities were also compared using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay. Then, the half-maximal inhibitory concentration (IC50) values of both honeys on TMZ-resistant glioblastoma cell line (DBTRG-05MG cells) were determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, while the analysis of cancer invasiveness and recurrence were determined through scratch assay and clonogenic assay respectively. After that, gene expressions between both honey-treated DBTRG-05MG cells were compared using quantitative reverse transcription polymerase chain reaction (qRT-PCR) to elucidate their effects towards apoptosis (MDM2 gene), metastasis (WNT5A gene) and chemoresistance (YTHDF2 gene). The analysis revealed that A. cerana honey contained higher levels of alkaloid and saponin as compared to H. itama honey, which contributed to its higher antioxidant activity as evidenced via the DPPH assay. This data was also supported by its lower IC50 value (130.5 ± 33.1 mg/mL) than H. itama honey (185.8 ± 27.6 mg/mL) in 72-hour treatment on DBTRG-05MG cells. In contrast, H. itama honey contained higher levels of flavonoid than A. cerana honey. Both honeys shared similar functional groups as indicated in FTIR analysis. A. cerana honey exerted strong inhibitory effect towards invasiveness and migration of DBTRG-05MG cells with its lowest closure percentage up to 72 hours while H. itama honey exerted strong prophylactic effect towards recurrence of DBTRG-05MG cells with its lowest colony number formed. However, there was no significant difference in MDM2, WNT5A and YTHDF2 expressions between honey-treated DBTRG-05MG cells. These findings suggest that A. cerana honey could be more effective in killing TMZ-resistant glioblastoma cells while H. itama honey could be more effective in preventing glioblastoma recurrence. The anticancer effect of each phytochemical in both honeys should be further investigated in future for better elucidation towards apoptotic, metastasis and chemoresistance mechanisms
Evaluation of etlingera elatior flower aqueous extract (EEAE) as treatment of colon cancer in rat model (pilot study)
(2025-01)
Shuang, Wee Lu
Colon cancer is a type of cancer that occurs in the colon or rectum. Therefore, sometimes it is also known as colorectal cancer (CRC). It is a leading cause of cancer-related deaths worldwide, even though there are available treatments for colon cancer, undesirable side effects often accompany it. Etlingera elatior, known as bunga kantan in Malaysia, is a traditional medicinal plant with high potential therapeutic effects with excellent antimicrobial, antioxidant, anticancer, antidiabetic, anti-inflammation, and anti-ageing properties. However, limited scientific research has been conducted on its antitumour effects against colon cancer. Therefore, this study investigates the in vivo antitumour effects of E. elatior flower aqueous extract (EEAE). EEAE is extracted using the sonication method. Toxicological assessment was performed using the brine shrimp lethality assay (BSLA) with a series of concentrations including concentrations of 10 mg/ml, 1 mg/ml, 3 mg/ml, 300 μg/ml, 100 μg/ml, 30 μg/ml, and 10 μg/ml. The LC50 of EEAE determined after the 24-hour incubation period was 2286 ppm (μg/ml), classifying EEAE as non-toxic based on Meyer and Clarkson toxicity standards. The antitumour efficacy of EEAE was further evaluated in an Azoxymethane-induced colon cancer model using male Sprague-Dawley rats. Histological analysis with Hematoxylin and Eosin (H&E) and Masson-Trichrome (MT) staining demonstrated substantial improvements in colon morphology upon treatment with EEAE. These findings suggest that EEAE is a promising natural product with antitumour properties against colon cancer, with no observed toxicity in vivo. Further research is warranted to explore its therapeutic potential and underlying mechanisms

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