Institut Perubatan & Pergigian Termaju - Tesis
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- PublicationThe Effects Of 940 Nm Diode Laser On Morphology And Temperature Of Human Extracted Teeth(2018-06)Ahmed Ghazal, Rehab MahmoudTooth sensitivity is a totally common dental condition that could cause a huge obstacle for dentist and patient, due to the short, sharp pain arising as a response to stimulation applied on uncovered dentine. The aim of this investigation is to evaluate the effectiveness of 940 nm diode laser as a treatment modality for dentine hypersensitivity. The laser is expected to cause ultrastructural changes of dentine such as narrowing and plugging the wide dentinal tubules. The safest parameters to be used on the dental tissues to provoke the melting of dentine layer without damaging the pulp tissue by heat will be defined. Seven sound, caries free upper premolar teeth with two roots were collected. The teeth were extracted for orthodontic purpose or periodontal disease. Dentine surface were irradiated with a 940 nm diode laser at different output power settings: 1.5 W, 2.0 W and 2.5 W, continuously for 10 seconds. Each tooth had been divided into 4 groups: Group A (control), Group B (1.5 W), Group C (2.0 W) and Group D (2.5 W). Diode laser irradiations at 2.0 W and 2.5 W led to effectively narrowing or sealing of dentinal tubules without provoking carbonisation or any destruction on the dentine surface. Samples that had been irradiated with 1.5 W showed partially narrowing of the dentinal tubules. The pulp temperature increased during irradiation, within a range of 2.6°C to 7.3°C. The temperature increment for all samples was statistically significant (p-value < 0.001). From this study, it is observed that irradiation of 940 nm diode laser at 2.0 W and 2.5 W settings, for 10 seconds in a continuous mode, is able to seal the dentinal tubules. Additionally, these parameters are within the safe range as assessed by the morphology and changes in temperature of the samples, which will not cause a harmful effect to the pulp tissues, and could be effective in the treatment of dentinal hypersensitivity.
- PublicationSeroprevalence Of Hepatitis B In First- Time Blood Donors Of National Blood Centre After Implementation Of National Vaccination Programmе(2018)SOW, EMMYBackground: Malaysia's prevalence of hepatitis B is about 5% with the related mortality rate of 0.04 in 2013. Transmission preventive measures were implemented via national vaccination programme since 1989 with vaccine coverage of 99.3%. In Malaysia, universal blood donor screening for hepatitis B virus (HBV) using serology method was implemented since 1974 while nucleic acid testing (NAT) began since 2007 in National Blood Centre. Objective: To determine the seroprevalence of hepatitis B among first-time blood donors after implementation of national hepatitis B vaccination programme. Methods: A cross sectional study involving review of 215 Malaysian first time donors records that was screened positive for HBV and donated between 1st January 2010 to 31st December 2015 at National Blood Centre. Results: The overall prevalence of hepatitis B among the first-time blood donors of NBC from 1st January 2010 to 31st December 2015 was 0.15%. The prevalence of hepatitis B was higher at 0.23% among donors born before year 1989 (pre-vaccination era) compared to 0.05% among donors born in and after year 1989 (post-vaccination era). More donors born pre-vaccination era have known risk factors compared to the other group of donors. The stages of infection were highest for non-replicating followed by replicating and convalescence regardless year of birth. Among donors born pre-vaccination era, majority (97.2%) were HBsAg+, all were anti-HBc+, 30.3% were HBeAg+ and 71% were antiHBe+. For donors born post-vaccination era, 98.6% were HBsAg+ and anti-HBc+, 50% were HBeAg+ and 48.6% were antiHBe+. All donors were NAT+ irrespective of year of birth. There was significant association of the seroprevalence for HBeAg and anti-HBe with year of birth (p < 0.05). There was no association between stages of infection with risk factors and demographic characteristics of donors (p > 0.05). Conclusions: The prevalence of HBV among donors who received birth vaccination was lower than those who did not. Occult infection (anti-HBc+, NAT+ with HBsAg-) was also reduced in donors who received birth vaccination. Implementation of national vaccination programme for HBV infection has contributed to the reduction of HBV infection and in minimizing the risk of transfusion-related transmission.
- PublicationPolymeric Nano-encapsulation Of Наемоglobin Isolated From Expired Human Redblood Cells For Use As Blood Substitute(2018)Mahmud, KhadijahTo date, blood scarcity in transfusion service demand vigorous scientific works looking for possible red blood cells alternatives. In this study, we aim to isolate and purify human haemoglobin (hb) from expired red cells by multiple washing, sonication, organic extraction and dialysis method. Analysis of the UV-Vis spectrum comparing hb and red blood cells (RBC) showed that the protein has been isolated successfully. Subsequently, the hb was encapsulated by polymeric micelle upon hydrophobic interaction (micellisation) of the methoxy poly (ethylene glycol)-b-poly (E-caprolactone) (PEG-PCL), a diblock copolymer in an aqueous buffer. The hb-micelle complex was then further analysed for half-life, oxygen reversibility, and cell-viability assay. Average encapsulation efficiency of the hb within the polymeric micelle achieved 45%. This is due to the high solubility of free hb in aqueous solution limiting the entry of hb into the polymer. However, the result indicated that the average of two units hb were successfully encapsulated by each polymer micelle. The hbmicelle recorded a higher half-life of 112,242 mins as compared to 30 mins of the free hb alone during oxygen stability study. The hb-micelle system also showed the ability to bind oxygen reversibly. Oxygenation and deoxygenation processes recorded average of six cycles before the sample was evaporated due to oxygenation, in contrast with only one cycle at average for free hb as a control. In cell viability study, the hb-micelle sample with concentrations of 1.89 x10³mg/mL in two preparations of micelles at 1.0 and 2.0 mg/mL while as a control, free hb sample from human and free bovine at 0.1 mg/mL and 0.2 mg/mL concentrations and also bovine hb-micelle (hb concentration at 2.21 ×105 mg/mL) have been tested on murine macrophage cells (RAW 264.7), incubated for 24 hours before treatments. Treated cells were then incubated further for 48 hours where the cell viability analysed at time points of 4, 8, 24 and 48 h. Generally, the free hb recorded reduction in cell growth approximately by 10% and 18% as early as 4h compared to hb-micelle which showed no toxic effects on the cells until 24 hours onwards. This result probably due to the free hb from human used in the test may have contained lipid debris from the membrane lysis during extraction process. However, it showed that hb-micelle system can safely interact with normal cells for potential future use compared to free hb without encapsulation by polymer. These findings indicated the potential of the hb 'harvested' from expired human red cells encapsulated by the diblock copolymer for development as red blood cells substitute.
- PublicationElucidating The Effect Of Kratom On Striatal Dopamine Transporter Level Using 99mtc Trodat-1 Spect-ct In Kratom Users(2023-05)Zulkifli, Nurul NadiahObjective: To evaluate and compare striatal dopamine transporter (DAT) level in kratom users and healthy controls utilizing 99mTc-TRODAT-1 single photon emission computed tomography with computed tomography (SPECT-CT) and brain MRI. Methods: A cross-sectional study involving 12 kratom users and 13 healthy controls was done at Unit Perubatan Nuklear, Institut Perubatan dan Perubatan Termaju (IPPT) USM. All subjects were male, aged between 18 to 55 years old without neurological or psychological diseases. kratom users were dependent on kratom for more than a year period and were free from illicit drugs abuse. Urine toxicology was done to exclude illicit drug abuse. They were also screened using DSM-V criteria for opioid dependence along with PHQ-9 and MMSE questionnaires. All subjects underwent 99mTc-TRODAT-1 SPECT-CT and brain MRI. The standard uptake value corrected with body weight (SUVbw) of bilateral caudate, putamen and striatum as well as occipital were drawn guided structurally by brain MRI images which were co-registered with processed SPECT-CT images. SUVr was calculated by dividing the target SUV with the occipital SUV. Results: Qualitative evaluation by two nuclear medicine physician showed almost perfect agreement that there were reduced tracer uptake in the right putamen (κ=0.824, p=0.004) and left caudate (κ=0.824, p=0.004), consequently abnormal finding in the overall image (κ=1.0, p<0.001). Semiquantitative evaluation revealed significantly higher right caudate SUVr of 2.06±0.67 in kratom users compared to 1.51±0.31 in healthy controls (p=0.019), accordingly higher right striatum SUVr of 1.98±0.50 in kratom user compared to 1.62±0.37 in healthy controls (p=0.055). The right caudate to putaminal ratio was also significantly higher at 1.09±0.25 compared to 0.89±0.14 (p=0.026) accordingly. The caudate AI% was high at 32.97% in kratom users versus 14.37% in healthy controls (p=0.04). The questionnaires parameter showed no significant difference between group. Conclusions:In conclusion, chronic kratom usage causes significantly higher right caudate SUVr, mimicking a pattern more like a cocaine-stimulant effect rather than the chronic heroin pioid effect. Although the effect of smoking in kratom users on striatal DAT binding is inevitable in this study, 99mTc-TRODAT-1 SPECT-CT-MRI may still be used as a potential imaging modality to assess the effect of chronic kratom use with further investigations in the future.
- PublicationIdentifying The Effect Of Biosynthesized Agnp From Garcinia Atroviridis Aqueous Extract On Induced T-regulatory Cells From Non-obese Resistance (Nor) Mouse Model(2018-08)MD Yusof, Nur AzirahCD4+CD25+ Foxp3+ T regulatory cells (Tregs) are important for maintenance of immune homeostasis. Thus, harnessing their function as immune modulator may be coupled with the rapid advancement of nanotechnology development. In the current study, biosynthesized silver nanoparticle (AgNP) from aqueous extract of Garcinia Atroviridis (GA) was used to identify its synergistic effect on modulatory properties of induced Treg (iTreg) cells from Non-Obese Resistance (NOR) Mice Model. Conventional CD4+ T cells were isolated using magnetic separation from NOR mice spleen and then cultured. Next, 1x105cells/mL were stimulated with anti CD3/CD28, TGF-B and IL-2 to induce CD4+Foxp3+ cells (iTreg). The cells were treated with or without GA-AgNP and were cultured for 120 hours. Expression of extracellular and intracellular markers were evaluated by using fluorochrome dye to detect CD4+, Foxp3,IL-17R, ICOS, TIGIT, P38, STAT5 and ERK1/2. Cells were analysed using BD FACS DIVA Cell analysis system. Control group was set as CD4+IL17Rhigh and stimulated with anti-CD3/CD28 and IL-2 only. Treated groups were designated as following: Group 1. anti-CD3/CD28, IL-2, TGF- ẞ Group 2. anti-CD3/CD28, IL-2, TGF- ẞ, GAAgNP and 3. anti-CD3/CD28, IL-2, GA-AgNP. Current results showed that GA-AgNP modulated the expressions of several molecules on isolated CD4+IL17Rhigh T cell population. Levels of CD4+ expression were significantly reduced in Group and Group 3 which were treated with GA-AgNPs as compared to control group. Similarly, Group 1 expressed almost similar patterns of molecular expression with control group. In contrast, transcription factor Foxp3 was not significantly induced in all groups as compared to control group. The expression of ICOS and TIGIT markers in CD4+IL17Rhigh cells in all groups remained unchanged as compared to control group.In contrast, transcription factor Foxp3 in all groups was not significantly induced compared to control group. The phosphorylation of p38 protein and ERK1/2 of MAPК pathways did not significantly detected in all groups of cells as compared to control group. None of the cell groups showed significant STAT5 phosphorylation level compared to control group. These findings may suggest GA-AgNP in modulating CD4+IL-17Rhigh cell population and did not significantly induce the formation of CD4+Foxp3+ cells. Thus, the addition of GA-AgNP in TGF-B/IL2 environment may trigger the plasticity of CD4+ cells into different population. Further studies are necessary to identify the molecular mechanisms involved. Current findings may serve as a basis for immunotoxicity study of nanomaterial used in therapeutic bio-products.