http://dspace.fsktm.um.edu.my/handle/1812/469 Search the Channel search http://dspace.fsktm.um.edu.my/simple-search http://dspace.fsktm.um.edu.my/handle/1812/627 Title: Influence of zinc in the sustenance prostate cell cancerous properties <br/> <br/>Authors: Pooi-Fong, Wong http://dspace.fsktm.um.edu.my/handle/1812/626 Title: Development of a novel polymeric gemcitabine derivative for brest cancer treatment <br/> <br/>Authors: Kiew, Lik Voon <br/> <br/>Description: Thesis (PhD) -- Faculty of Medicine, Universiti Malaya, 2008. http://dspace.fsktm.um.edu.my/handle/1812/622 Title: Thrombophilia investigations in Malaysian women with recurrent pregnancy loss <br/> <br/>Authors: Thiruchelvam Ayadurai <br/> <br/>Abstract: BACKGROUND: The status of thrombophilia in Asian women with recurrent abortions and stillbirths is obscure and poorly understood. Collectively known as recurrent pregnancy loss (RPL), it is now apparent that thrombophilia is responsible for a large number of failed pregnancies. Thrombophilia exerts a thrombotic risk at the placental-microvasculature, compromising the well-being of the developing fetus and culminating in poor pregnancy outcome. The common thrombophilia risk factors are: Factor V Leiden (FVL) and Prothrombin G20210A (PT G20210A) mutations of the haemostasis system, activated protein C resistance (APCR) and protein C and S deficiencies of the protein C pathway, autoimmune antibodies of antiphospholipids and lupus anticoagulant, and Methylene Tetrahydrofolate Reductase (MTHFR C677T) mutation of the homocysteine metabolic pathway. The two most common thrombophilia markers, FVL and PT G20210A, have been identified in Caucasian subjects with a prevalence of between 8.0% to 48.0% and 1.0% to 8.0%, respectively. However, numerous studies have documented the non-existence or extreme rarity of these two important thrombophilia markers in patients with Asian ancestries - hence, the basis for the overwhelming assumption among the local clinicians that thrombophilia is rare among Asians and therefore, laboratory investigations are irrelevant. Consequently, the diagnosis of thrombophilia-induced RPL and its management with antithrombotic therapy in Malaysian women with unexplained RPL is rare in clinical-practice. The Maternity Hospital in Kuala Lumpur registered a high prevalence of unexplained pregnancy losses among young “healthy” Malaysian women. These subjects were free from all known pathologies, except for thrombophilia, which was never investigated. This study attempts to test the hypothesis that a significant number of Malaysian women with RPL, like their Caucasian counterparts, have thrombophilia abnormalities. In doing so, the study would also be determining the relationship between thrombophilia and unexplained RPL, in otherwise healthy Malaysian women (RPL-subjects). METHOD: 402 RPL-subjects and 160 healthy parous-controls from three main ethnic groups of the Malaysian population (Malays, Chinese and Indians) were investigated for thrombophilia. FVL, PT G20210A and MTHFR C677T were identified by polymerase chain reactions. APCR, protein C (PC), protein S (PS), antithrombin (AT) and antiphospholipid (aPL) antibodies were identified using clot-based, chromogenic and enzyme-linked immunosorbent assays. RESULTS: Thrombophilia was identified in 27.4% (110/402; p<0.001) of the RPL-subjects, compared to 1.25% (2/160) in the parous-controls. APCR occurred in 21.6% (87/402; p<0.001) of the RPL-subjects. The abnormalities in the PC pathway was caused by FVL (9.2%=8/87), PS deficiency (51.7%=45/87), PC deficiency (6.9%=6/87), combined PS and PC deficiencies (6.9%=6/87) and unidentifiable “Non-specific” abnormalities (25.3%=22/87). FVL (2% vs 0%) and PT G20210A (0.5% vs 0%) were identified in the Malay and Indian ethnic RPL-subjects. The Chinese ethnic group was free from the FVL and PT G20210A mutations. MTHFR C677T occurred with a higher prevalence in the RPL-subjects compared to the parous-controls (35.3% vs 23.1%; p=0.002). Antiphospholipid antibodies were detected in 5.0% (p=0.019) of the RPL-subjects, however only one RPL-subject had AT deficiency (0.25%). CONCLUSION: Thrombophilia was identified in more than one-quarter (27.4%) of the so-called “healthy” Malaysian women with unexplained RPL, thereby confirming the hypothesis that thrombophilia is indeed a significant abnormality in the RPL-subjects. APCR was the most common thrombophilia marker - being identified in more than one-fifth (21.6%) of the RPL-subjects investigated. Acquired APCR was more prevalent in the Asians, whereas in the Caucasians it was the Inherited form. FVL and PT G20210A were identified in the Malay and Indian ethnic groups, disputing all previous studies on the non-occurrence of both these mutations in patients with Asian ancestries. Thrombophilia is an important pathology to be reckoned with and should no longer be considered a rare disorder among Malaysian women with RPL. In light of the present evidence, local clinicians should now re-consider thrombophilia investigations for Malaysian women with unexplained RPL, with the option of extending this investigation to other thromboembolic disorders in Malaysian patients. <br/> <br/>Description: Thesis (PhD) -- Faculty of Medicine, Universiti Malaya, 2008. http://dspace.fsktm.um.edu.my/handle/1812/591 Title: Pathology and pathogenesis of Nipah virus infection in humans and animal model <br/> <br/>Authors: Wong, Kum Thong <br/> <br/>Abstract: In 1998, an outbreak of acute encephalitis in Malaysia led to the discovery of a novel paramyxovirus named Nipah virus (NiV). Subsequently, outbreaks were also reported in Bangladesh and India. So far, the number of people infected is more than 500 with mortality between 40-70%. NiV is closely related to Hendra virus (HeV), both belonging to the new genus, Henipavirus (family Paramyxoviridae). The natural host of henipaviruses is the pteropid or fruit bat whose range includes Africa, Asia- ceania and Australia. In the NiV outbreaks in Malaysia and Singapore, the intermediate host was the pig, while in Bangladesh and India, direct bat-to-human and human-to-human transmission occurred. Acute NiV infection may be asymptomatic; symptomatic cases present with fever and headache or acute encephalitis often associated with coma. Most patients recovered without serious sequelae but a small percentage developed relapsed/late-onset NiV encephalitis. HeV infection is also associated with relapsed encephalitis but acute encephalitis has not been previously reported. To study the human pathology of NiV infection, 31 cases of acute infections and 3 cases of relapsed/late-onset encephalitis were examined. These findings were compared with human HeV, and infections in a hamster model (Mesocricetus auratus). Tissues were examined by histology, immunohistochemistry, electron microscopy, in situ hybridisation and other molecular techniques. In acute NiV infection, there were systemic vasculitis and discrete, plaque-like, parenchymal necrosis and inflammation in most organs, particularly in the central nervous system (CNS). Vascular endothelial damage, multinucleated syncytia and vasculitis resulted in thrombosis, vascular occlusion, ischaemia and microinfarction. Viral antigens were immunolocalised to the vascular wall. Viral inclusions, nucleocapsids, antigens and RNA were also detected in extravascular parenchymal cells especially in neurons. The pathogenesis of acute NiV infection appears to be a unique dual mechanism of vasculitis-induced thrombosis, ischaemia/microinfarction, and direct parenchymal cell infection. In relapsed/late-onset NiV encephalitis, CNS-limited lesions consisted of mildly inflamed, vacuolated necrotic lesions merging with confluent areas of more extensive neuronal necrosis and increasing inflammation. Some lesions had a distinctive concentric or wave-like morphology. There were neuronal viral inclusions, antigen/RNA and nucleocapsids but vasculitis was absent throughout. These findings suggest that relapsed/late-onset encephalitis is a recurrent infection rather than post-infectious encephalitis, and that reinfection is unlikely to have arisen from extraneural foci. The case of acute HeV infection that had no clinical encephalitis showed evidence of systemic vasculitis and parenchymal cell involvement. Virus inclusions and antigens/RNA were found especially in neurons. Relapsed HeV encephalitis was characterised by severe meningoencephalitis with neuronal infection, inflammatory cells and reactive blood vessels. Vasculitis was absent. Hence, human HeV infection appears to be similar to acute and relapsed NiV encephalitis, respectively. Hamsters with acute henipavirus infections demonstrated vasculitis, thrombosis and the rare endothelial syncytia in blood vessels of multiple organs. Viral antigens/RNA and nucleocapsids were localized in vascular and extravascular tissues in the CNS and other organs. Infectious virus and/or RNA could be recovered from tissues and urine. The pathology and pathogenesis of acute henipavirus infection in humans and hamsters appears to be very similar. Human relapsed/late-onset NiV encephalitis and relapsed HeV encephalitis are both recurrent infections. Thus, the henipaviruses share common biological characteristics including the ephrin B2 virus entry receptor, pathology and pathogenesis. <br/> <br/>Description: Thesis (PhD) -- Faculty of Medicine, University of Malaya, 2008. http://dspace.fsktm.um.edu.my/handle/1812/590 Title: Activity and polymorphism of Paraoxonase 1 in the Malaysian population <br/> <br/>Authors: Rozaida Poh, Yuen Ying <br/> <br/>Abstract: PON1 is an esterase that is associated with HDL. Polymorphisms at positions 55 and 192 of the PON1 gene have been associated with accelerated atherosclerosis that leads to development of premature cardiovascular disease. However the role of PON1 in cardiovascular disease complications in type 2 DM has not been not fully understood. The variation in gene frequencies in a Malaysian population comprising three ethnic groups for the polymorphisms at PON1 was determined using conventional PCRbased genotyping and two-substrate activity assays. The pooled observed frequencies in a sample of 353 subjects for the L, M, Q and R alleles were 0.901, 0.099, 0.459 and 0.541, respectively. The most common genotype was LL/QR (37%) followed by LL/RR (31%). A higher frequency of the M allele was found in subjects of Indian ethnicity compared to other ethnic groups (p<0.001). A strong linkage disequilibrium between L/55 and R/192 alleles was observed (P<0.0001). These analyses suggested that polymorphisms of PON1 observed are associated with ethnicity. The association of polymorphisms in PON1 with complications in type 2 DM was examined in a sample of 188 non-diabetic and 140 diabetic subjects using association tests adjusted for age. The polymorphisms of PON1 at positions 55 and 192 were not associated with complications in type 2 DM (p=0.218, p=0.847, respectively). Univariate analysis of PON1 activity towards paraoxon in these subjects using general linear models adjusting for age revealed that reduced PON1 activity towards paraoxon was associated with increased risk of CVD complications in type 2 DM (p=0.023) compared to diabetics without complications. Multivariate analysis of two plasma measures of PON1 activity using paraoxon and diazoxon also showed that a reduced PON1 activity towards paraoxon was associated with increased risk of CVD complications in type 2 DM (p=0.045). These analyses revealed that both activity measures were independent of PON1 polymorphisms. In addition, these analyses also showed that a reduced PON1 activity towards paraoxon was associated with ethnicity. Similarly, ethnicity was associated with PON1 polymorphisms (p<0.001). Based on multivariate analysis, subjects of Malay ethnic origin were expected to have higher activity towards paraoxon than subjects of Chinese origin (p=0.008, compared to Indians). Chinese subjects in turn were expected to have higher PON1 activity than Indian subjects (p=0.028, compared to Indians). Discordance between genotype and phenotype was found in three subjects in the sample population and was resolved using DNA sequencing of the PON1 polymorphism at position 192. Hence, the PON1192Q or –R allele was predicted to be inactive in heterozygotes. The effect of PON1 polymorphisms on kinetics of PON1 was examined. KM values between genotypes was not significantly different (p>0.05). However, Vmax was significantly increased according to the polymorphisms in both basal (p<0.05) and saltstimulated assays (p<0.001). Ki was not significantly different between genotypes (p>0.05). The inhibition of paraoxon by phenylacetate was of the linear mixed type. <br/> <br/>Description: Thesis (PhD) -- Faculty of Medicine, University of Malaya, 2009. http://dspace.fsktm.um.edu.my/handle/1812/574 Title: Mechanisms of resistance to Carbapenems in Acinetobacter species <br/> <br/>Authors: Wong, Eng Hwa <br/> <br/>Abstract: Carbapenem-resistant Acinetobacter spp. have gained increasing significance as opportunistic pathogens in hospitalized patients. Reports of multidrug-resistant isolates have increased considerably over the last decade, partly due to the extensive use of broad-spectrum antibiotics. Carbapenem resistance is often associated with the loss and or decrease in outer membrane proteins and overexpression of multidrug efflux systems. However, carbapenem-hydrolyzing β-lactamases of Ambler Class B (metallo-enzymes) and Ambler Class D (oxacillinases) have also been detected in Acinetobacter spp. In this study, we describe a study on carbapenem resistance mechanisms involved in Acinetobacter spp. isolated from University Malaya Medical Centre (UMMC). A total of 39 carbapenem-resistant clinical isolates of Acinetobacter spp. were obtained from inpatients of UMMC from August 2003 until March 2004. All 39 strains were identified as Acinetobacter baumannii-calcoaceticus complex using the API20NE system and Fluorescent in-situ hybridization (FISH). Growth at 44°C distinguished the 36 A. baumannii strains from the 3 A. calcoaceticus. The antibiotic susceptibility profiles to β-lactams were determined by the minimum inhibitory concentration (MIC) using the agar dilution method as described by the Clinical and Laboratory Standards Institute, CLSI. ATCC strains of Escherichia coli 25922 and Pseudomonas aeruginosa 27853 were used as controls. Out of the 39 imipenem-resistant strains screened by the IMP-EDTA-double disk synergy test and Modified Hodge test, only two strains, S26 and S90 were positive for the presence of metallo-β-lactamases, whereby these enzymes were inhibited by EDTA or 2-mercaptopropanoic acid. Both these strains had similar MIC values for imipenem, and cefotaxime at 32 and 512 μg/ml, respectively. IEF analysis showed that both strains had a band of pI 8.0 which corresponded to that of blaIMP-4, while an additional band of pI 7.0 was present in strain S90. The two strains, S26 and S90, were PCR positive for blaIMP. Amplification and subsequent nucleotide sequencing of the entire coding region of blaIMP confirmed the identity of the blaIMP amplicon to be blaIMP-4. However, none of the 39 isolates harbored blaVIM. Besides that, 37 out of the 39 strains harboured blaOXA-23. Plasmid analysis revealed that the two imipenem-metallo-β-lactamase-producing strains (MBLs), S26 and S90, carried plasmids: 147 kb, 50 kb, 36 kb in both strains with an additional 7 kb plasmid in S26. Southern blot hybridization showed that the blaIMP-4 gene was located on the 50 kb plasmid. Screening for Class 1 integrons revealed two bands of 2.5 kb and 3 kb in 31 out of the 39 carbapenem-resistant strains of Acinetobacter spp. Restriction enzyme analysis with AluI revealed 3 fingerprint profiles. Sequencing of the entire gene cassette representatives of each profile revealed that strains with profile 1 (2.5kb) contained the aacC1 gene, whereas the larger (3kb) integron cassette (profile 2) was identical to that of profile 1 with the exception of an additional copy of the orfX gene. Both the blaIMP-4 producing A. calcoaceticus strains, S26 and S90, had a unique profile 3. Nucleotide sequencing of the inserted gene cassettes revealed identical genes: blaIMP4, qacG, aacA4, and catB3. Although identical cassette arrays were found in integrons of the IMP-4 producing strains, PFGE analyses showed that S26 and S90 had different genotypes. Southern blot hybridization using blaIMP-4 probe showed positive hybridization of the Class 1 integron. Screening of efflux pump genes among the 39 strains showed that 36 strains carried all the 3 genes (adeA, adeB, and adeC), while the remainder 3 strains had one or two of the genes detected. Inactivation of adeB gene has led to decreased MIC levels to meropenem indicating its contribution towards the development of carbapenem resistance. Besides that, all the strains showed loss of a 29-kDa OMP. The polyclonal antibodies produced showed bactericidal effect against the organism tested and it specifically killed the bacteria grown in iron deficit medium, suggesting a potential target for antimicrobial therapy. Overall, in this study, the clinical isolates of A. baumannii and A. calcoaceticus posses several characteristics that make it well equipped to emerge as significant nosocomial pathogen in the hospital settings of UMMC. Majority strains of about 36 that were identified as A. baumannii harboured the blaOXA-23 (Class D enzyme). This enzyme belongs to the three unrelated groups of clavulanic acid-resistant β-lactamases, represented by OXA-23, OXA-24, and OXA-58, those posses as intrinsic carbapenem-hydrolyzing oxacillinases and may play a role in carbapenem resistance. However, blaOXA-23 gene was not detected in the two A. calcoaceticus, S26 and S90 which harboured the blaIMP-4 gene. The blaIMP-4 gene that harboured by these strains was found to be carried on the Class 1 integron which is located in the plasmid and this may assist in development of resistance. Besides the enzymatic based mechanisms, broad-spectrum antimicrobial resistance can also be due to a variety of intrinsic and acquired mechanisms. One such important feature is loss or decreased permeability of the outer cell membrane. In this study, a 29-kDa OMP has been identified to be the major outer membrane protein in A. baumannii / A. calcoaceticus and loss of this porin has contributed to carbapenem resistance. Finally, efflux pumps belonging to the Resistance Nodulation Cell Division (RND) family has also been determined in these strains and was found to be associated with resistance to aminoglycosides, fluoroquinolones, cefotaxime and also to meropenem. These suggest that, multiple mechanisms are involved for carbapenem resistance in Acinetobacter spp. and therefore, understanding carbapenem resistance mechanisms might be crucial for the development of novel therapeutic strategies. However, it will be an important approach in the near future if one attempts to determine possible targets for new agents to control antimicrobial resistance in nosocomial pathogens such as Acinetobacter spp. <br/> <br/>Description: Thesis (PhD) -- Faculty of Medicine, University of Malaya, 2008. http://dspace.fsktm.um.edu.my/handle/1812/497 Title: Quality of life, interpersonal relationships and coping strategies of the women with breast cancer and their husbands <br/> <br/>Authors: Mohd Nasir B Che Mohd Yusoff <br/> <br/>Abstract: Psychosocial morbidity such as the quality of life impairment; change in the pattern of interpersonal relationship and coping behavior are consequences of breast cancer on women’s life and their significant other, i.e. husband. The first objective of this study was to examine the effects of the treatment phases (prior-to, during and post-chemotherapy) on the quality of life (QOL), interpersonal relationship (IR) and coping strategies (C) of women with breast cancer and their husbands, as well as to examine the patterns and levels of QOL, IR and C among these couples, following breast cancer surgery. Secondly, it was done to observe the effects of the medical factors (types of surgery and breast cancer stages) and bio/socio-demographic factors (menopausal status and ethnicity) on the QOL, IR and C of the women with breast cancer and their husbands. Thirdly, it was done to determine factors predictive of women’s global health status, sexual attractiveness, relationship satisfaction and coping strategy post-chemotherapy. This study was carried out prospectively with three times evaluation: Phase one/ prior-chemotherapy following breast cancer surgery (seven weeks after diagnosis or three weeks after surgery), Phase two/ during chemotherapy (14 weeks after diagnosis or 10 weeks after surgery) and Phase three/ post-chemotherapy (23 weeks after diagnosis or 19 weeks after surgery). One hundred and fifty seven women with breast cancer (mean age: 48.29±8.85sd) and 157 husbands (52.21±9.01sd) participated in this study. Majority of the women had undergone mastectomy (79.4%, n=127). Over half of the women were diagnosed with stage two of breast cancer (56.9%, n=91). Various standardized self-administrated scales were used: Quality of life evaluation [European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC-QLQ C30), Breast Module (QLQ BR-23), Hospital Anxiety and Depression Scale (HADS), Blatt Menopausal Index (BMI)], Sexuality evaluation [Body Image Scale (BIS) and Sexual Attractiveness: Body Esteem Scale (SABES)], interpersonal relationship evaluation [Inventory of Socially Supportive Behaviour (ISSB), Level of Disclosure, Helpfulness of Disclosure, Criticism, Withdrawal, Empathy: Revised Barrett-Lennard Relationship Inventory (E-RBLRI), Dyadic Satisfaction: Dyadic Adjustment Scale (DS-DAS)] and coping strategy evaluation [Brief COPE]. Husbands answered similar scales for HADS, DS-DAS and Brief COPE and some scales were modified for this purpose. All scales were translated and validated locally to cater for the multicultural ethnicity of the Malaysian population. Medical and bio/socio-demographic data were also gathered. Results showed that couples’ psychological aspect (anxiety and depression), relationship satisfaction and most of the coping strategies (Active Coping, Planning, Positive Reframing, Acceptance, Using Emotional Support, Using Instrumental Support, Denial, Venting, Self-blame, Emotion-focused Strategies and Problem-focused Strategies) exhibited significant effects of time, where women obtained higher scores in all aspects than their husbands. Nevertheless, the types of surgery and breast cancer stages did not affect couples’ psychological aspect, relationship satisfaction and their coping strategies, the fact which contradicts with the menopausal status and ethnicity. The significant effect of time was also observed for the main domains of quality of life i.e. Global Health Status, Physical Functioning, Role Functioning, Emotional Functioning and Social Functioning, sexuality (body image and attractiveness), as well as their interpersonal relationship aspects (Perceived Husband Support, Level of Disclosure, Empathy, Criticism and Withdrawal). The regression model indicated that women’s depression was predictive of their global health status. Women’s sexual attractiveness was predicted by their body image and anxiety; as well as their husbands’ view on their sexual attractiveness and body image. Meanwhile, women’s relationship satisfaction was predicted by their depression, perceived husband’s support, empathy, helpfulness of disclosure, husbands’ relationship satisfaction and husbands’ perceived providing support. Women’s age and their perceived husband’s support are predictive of their problemfocused strategy. In conclusions, the treatment phases of chemotherapy, following breast cancer surgery, were revealed to have significant impacts on the quality of life, interpersonal relationship and coping strategies of women with breast cancer and their husbands, with the similar patterns over the time. Bio/socio-demographic factors such as menopausal status and ethnicity are important determinants in these psychosocial aspects of breast cancer. Healthcare organizations should implement broaden breast health-related programmes targeting the family of women with breast cancer. <br/> <br/>Description: Thesis (PhD) -- Faculty of Medicine, University of Malaya, 2009. http://dspace.fsktm.um.edu.my/handle/1812/494 Title: Implications of the Glycoxidation product, Nε- (Carboxymethyl) lysine in the altered metabolism of low density lipoprotein in patients with type 2 diabetes mellitus and coronary artery disease <br/> <br/>Authors: Khaled Abdul-Aziz Ahmed <br/> <br/>Abstract: Hyperglycemia has been implicated as a major risk factor for development of the complications of diabetes. Recent investigations have shown that advanced glycation end products (AGEs) are thought to play a crucial role in this process. Nε- (carboxymethyl)lysine (CML), the predominant antigenic advanced glycation end product in vivo, is known to be a product of both glycation and oxidative modification of glycated proteins. Glycation and oxidation of low density lipoproteins (LDL) are known to increase the atherogenic potential of LDL in type 2 diabetes mellitus (T2DM) by reducing its affinity for the LDL receptor, thus leading to reduced hepatic catabolism and increased accumulation of cholesteryl esters in macrophages and subsequently result in endothelial dysfunction. The purpose of this study was to determine the levels of CML in patients with T2DM with and without coronary artery disease (CAD) and to find for a possible use of CML measurements as a prognostic biomarker of CAD in T2DM. This study aimed to clarify the role of Nε-(Carboxymethyl)lysine in the uptake of LDL by classic LDL receptors which can potentially give rise to increased risks of cardiovascular disease such as CAD in T2DM. Polyclonal anti-CML antibodies, developed in female New Zealand white rabbit, were used for measurement of serum CML. CML levels were measured by competitive ELISA in the serum of T2DM patients (with and without CAD), nondiabetic CAD patients, and age-and sex-matched healthy subjects. Serum levels of the lipid peroxidation product; malondialdehyde (MDA), lipid profile, and hemoglobin A1c (HbA1c) tests were also assessed in the study groups. Correlations studies between CML levels and lipids, HbA1c, and lipid peroxidation were performed for the study populations. LDL fractions from the T2DM groups were isolated and labeled with the fluorescent 3,3'- dioctadecyloxa-carbocyanine perchlorate (DiI) dye. LDL particles from healthy subjects were subjected to oxidation, glycation, glycoxidation and carboxymethylation. Receptormediated uptake of labeled native-LDL and in vivo and in vitro modified-LDL was evaluated in human hepatoma (HepG2) cell line. Serum levels of CML were significantly higher in T2DM with CAD patients than diabetic patients without CAD, nondiabetic CAD patients, and healthy control individuals. CML levels were highly correlated with MDA and strongly predicted CAD in patients with type 2 diabetes. In addition, LDL isolated from T2DM patients suffering from CAD complications revealed enhanced susceptibility to oxidation and had higher CML contents than T2DM subjects not having CAD. The cellular uptake of DiI-LDL from T2DM patients with CAD, glycoxidized-LDL and CML-LDL was significantly lower than that for LDL from diabetic patients without CAD, oxidized-, or glycated-LDL. In conclusion, this study has demonstrated the effect of both diabetes and oxidative stress on the higher levels of circulating CML and showed that CML levels are associated with the development of CAD in patients with T2DM. It is also concluded that CML-LDL, rather than either AGE-LDL or oxidized-LDL, may be largely responsible for the defective uptake of LDL by the LDL receptor. Hence, CML may be used as an endogenous marker for early detection of CAD events in T2DM patients and may be considered as a new goal for the glycemic control in these patients. <br/> <br/>Description: Thesis (PhD) -- Faculty of Medicine, University of Malaya, 2008. http://dspace.fsktm.um.edu.my/handle/1812/481 Title: Molecular detection and characterization of antibiotic resistance genes in clinical Malaysian S. aureus isolates <br/> <br/>Authors: Shafiei Sabet, Negar <br/> <br/>Abstract: This study aimed to utilize molecular techniques to develop rapid molecular methods for detection of Staphylococcus aureus (S. aureus) and subsequently to study important antibiotic determinants and characterize S. aureus isolates from Malaysia. 152 clinical isolates from University Malaya Medical Center (UMMC) were used in this study. Conventional and real-time multiplex PCR assays for simultaneous identification and detection of major antibiotic resistant genes were developed to enable rapid confirmation of resistance patterns within these isolates. The first assay was a conventional gel-based quadruplex PCR assay that targeted four genes mecA (methicillin resistance) Coa (coagulase) Sa442 fragment (species specific) and 16S rRNA (internal control). Inclusion of CoA gene along with the Sa442 marker, which is specific for S. aureus, increased the specificity of the assay by being able to simultaneously detect two specific markers for the identification of S. aureus. Subsequently, a triplex real-time PCR assay was developed using three of the primer pairs utilized in conventional assay which enabled a more curate comparison on the specificity and sensitivity of these assays. Both assays enabled the detection of Sa442 fragment in all S. aureus isolates. The next part of the study focused on designing the more complete assays for simultaneous identification of the organism and detection of antibiotic resistance genes and this resulted in the development of two new triplex real-time PCR assays. The first of these assays enabled identification of S. aureus using femA gene and detection of two important antibiotic resistant genes mecA, (methicillin resistance) and aacA-aphD (aminoglycoside resistance) thereby ombining the detection of MRSA (methicillin-resistant S. aureus) and aminoglycoside resistance in single real-time PCR assay. Evaluation of this assay correlated well with the results of the phenotypic antibiotic susceptibility testing. The second real-time PCR assay combined the detection of MRSA (mecA and femA), and erythromycin resistance (ermA) in a single assay. All the three genes were detected in all MRSA isolates tested. The triplex real-time PCR assays that were developed are rapid (performed within three hours) sensitive and specific assays which enable the detection of S. aureus as well as antibiotic resistance pattern. The high incidence of MRSA isolates in our center led to the next part of our study which was to determine the clonality, if any, of these isolates. The coagulase gene, which was used in the identification of S. aureus and other staphylococci, was used in a simple typing assay using restriction fragment length polymorphism (RFLP) to analyze 40 S. aureus isolates. This coagulase gene RFLP analysis showed that all the MRSA that were digested with two restriction enzymes, AluI and CfoI, showed the same pattern for each enzyme used which is suggestive of the presence of a single clone of MRSA in our hospital setting. The MSSA (methicillin-sensitive S. aureus) strains, however, showed seven distinct patterns, none of which resembled the pattern generated by the MRSA strains. The next part of our study focused on whether the transfer of mecA occurred from MRSA to MSSA strains in vitro. Liquid cultures consisting of donor strains harboring the mecA gene (mecA+) and recipient strains (mecA-) were combined prior to being plated out on selective antibiotic plates. Two types of ransconjugants (transconjugants A and B) were obtained which were analyzed using PCR to detect the presence of mecA and ccrAB (transfer factor) genes. The mecA gene was present in donor and both transconjugants A and B. The ccrAB gene was present in the donor, and both the transconjugants A and B. To study molecular basis of the mechanisms involved in development of resistance to the cell wall active antibiotic oxacillin, microarray study were performed. The retrospective analysis helped to identify a subset of genes that were differentially expressed in methicillin-resistant strains upon exposure to antibiotic oxacillin. Genetic determinants involved in various functional groups such as stress response, regulatory function, cell envelope/cell wall biogenesis, DNA replication, recombination and repair mechanism were found to be strongly expressed in MRSA strain during oxacillin treatment. These findings indicate a possible change in regulation of transcription as contributory factor in the development of antibiotic resistance in S. aureus. <br/> <br/>Description: Thesis (PhD) -- Faculty of Medicine, University of Malaya, 2008. http://dspace.fsktm.um.edu.my/handle/1812/479 Title: Common misconceptions and attitudes toward psychology and mental health: a Malaysian context <br/> <br/>Authors: Yeap Kah, Min Reiko <br/> <br/>Abstract: This study examines the Malaysian public’s knowledge and attitude towards psychology and mental health. The study aims to help improve the public understanding of the diversity of psychology, which is far beyond just simply common sense or limited to the study of mental illness. In addition, it is also the objective of this study to examine how much the general public knows about mental health as well as to explore effective tools to promote good mental health. This research consists of two studies. Study one, a household survey, involved face to face interviews with a representative sample of the Malaysian population residing in Klang Valley. A total of 587 respondents aged 18 and above (90% response rate) responded to a series of questions in relation to psychology and mental health issues developed based on previously published studies and interviews with psychologists/ psychology instructors, sociologists, social workers, and psychology graduates. Respondents were requested to answer ‘Yes’, ‘No’, ‘I don’t know’, as well as to specify how they learned about the information. Following that, an attitude scale was presented to the participants, in which respondents were requested to rate how much they agree to the statements. The findings indicated that the majority of the respondents (90%) did not have good knowledge of psychology and mental health issues. However, all respondents displayed a more or less neutral attitude towards psychology (the profession) as well as mental health issues. The results seemed to suggest that respondents’ knowledge level is not related to their attitude level. Factors predicting good mental health knowledge, attitude, and help-seeking tendency for mental health issues were explored. Regression analysis indicated that age, ethnic background, religion, education level, and residential location are the few demographic characteristics found to be significantly related to either respondent’s knowledge, attitude towards mental health issues or help seeking behaviour. The second study was conducted using a cross-sectional quantitative survey of 246 university/ college students enrolled in psychology courses at the undergraduate level in four universities/ colleges in Klang Valley. A scale, similar to the first study, with additional items included, was developed to examine students’ attitude and knowledge about psychology and mental health. The findings indicated that undergraduate students harbor misconceptions about psychology regardless of their declared major (psychology and non-psychology major) and demographic characteristics. Interestingly, students’ knowledge level in both psychology and mental health were significantly better than the general public. Among the 246 student participants, 83 student participants who were enrolled in the Introductory Psychology course agreed to take part in a longitudinal study. The same questionnaires were redistributed to the students upon completion of the course. The pre- and post-course design was conducted to examine if introductory psychology course would help dispel misconceptions. Results indicate that the number of correct responses increased significantly suggesting that misconceptions about psychology and mental health can be dispelled. Based on the research findings, it is obvious that the knowledge of psychology and mental health among general public is very limited. Although students enrolled in psychology courses are better informed, misconceptions prevailed. Steps should be taken to improve public’s understanding and attitude; some suggestions include positive image presentation, dissemination of accurate information by the mass media, which was rated as the primary source for information on psychology and mental health. <br/> <br/>Description: Thesis (PhD) -- Faculty of Medicine, University of Malaya, 2008.