1.Mechanical And Surface Properties Of Initial And Working Aesthetic Orthodontic Archwires
Tang YC ; Peh XL ; Zakaria N N ; Radzi Z
Annals of Dentistry 2016;23(1):17-28
The study aimed to compare mechanical properties and surface characteristics of initial and workingaesthetic archwires with their conventional counterparts. High Aesthetic Sentalloy (full rhodium coatingnickel-titanium; Dentsply GAC) represented the initial aesthetic archwires; and FLI TRU-CHROME(labial PTFE-coated stainless steel; RMO) as the working aesthetic archwires; together with theirconventional counterparts were analysed. A three point bending test was conducted using a universaltesting machine (AGS-X SERIES, Shimadzu, Japan) to determine the load-deflection characteristics ofarchwires. Surface hardness was evaluated by Vickers microhardness test (HMV-FA, Shimadzu, Japan).A 3D Optical Surface Texture Analyzer (ALICONA, InfiniteFocus Real3D, Belgium) and a Field EmissionScanning Electron Microscope (FESEM, FEI Quanta 250, USA) were used for surface evaluation.Results showed that load-deflection characteristics of High Aesthetic Sentalloy archwires did not differfrom its control, whereas FLI TRU-CHROME archwires exhibited higher loading and unloading forcesthan its counterpart. No statistically significant difference in surface hardness was found between FLITRU-CHROME and its control archwires. The coating surfaces of both aesthetic archwires were rougherthan the non-coated conventional archwires, with similar roughness between non-coated surface of FLITRU-CHROME archwires and its counterpart. FLI TRU-CHROME archwires showed a distinct coatingthickness but coating layer is undefined in High Aesthetic Sentalloy archwires. In conclusion, the aestheticrhodium coated nickel titanium archwire has similar mechanical properties as control nickel titaniumarchwire without being adversely affected by the addition of the coating layer. The aesthetic coated PTFEstainless steel archwire has higher load response which could be an advantage as rigid wire in workingstage of orthodontic treatment. Based on their performance, their use could be recommended in caseswhere aesthetic aspect is crucial and where the friction aspect is not critical as their surface roughnessvalues increased.
2.Presence of methicillin resistance and heteroresistance among Coagulase Negative Staphylococci (CoNS) isolates obtained from Health Sciences students at a Public University
Pung, H.P. ; Mat Azis, N. ; Abdul Rachman, A.R. ; Zakaria, Z.A. ; Mohd Desa, M.N.
Tropical Biomedicine 2017;34(1):84-88
This study was carried out to investigate the Coagulase Negative Staphylococci
(CoNS) nasal carriage and the presence of methicillin resistant Coagulase Negative
Staphylococci (MR-CoNS) among health sciences students at Faculty of Medicine and Health
Sciences, Universiti Putra Malaysia. A total of 120 isolates of CoNS (62.5%) was isolated from
192 student volunteers. The mecA gene was detected in 15 isolates of CoNS (12.5%). Eight
out of the 15 isolates of mecA positive CoNS were resistant to cefoxitin in disc diffusion test
whereas the remaining seven isolates of mecA positive CoNS were susceptible to cefoxitin.
Analysis of questionnaires showed no significant association between CoNS nasal carriage
and the socio-demographic and risk factors except for the genders and history of cold
(P < 0.050). Generally, this finding showed a relatively low level of methicillin resistance
among CoNS nasal carriage from student volunteers.
3.Haemoglobin Sickle D Punjab: - A Case Report
Rahimah Ahmad ; Syahira Lazira Omar ; Siti Hida H M Arif ; Faidatul Syazlin A Hamid ; Nur Aisyah Aziz ; Nik Hafidzah N Mustapha ; Zubaidah Zakaria
The Medical Journal of Malaysia 2014;69(1):42-43
Haemoglobin S D-Punjab is a rare compound heterozygous
haemoglobinopathy characterised by the presence of two β
globin gene variants: β6(GAG→GTG) and β121(GAA→CAA).
These patients’ clinical and haematological features mimic
haemoglobin S disease. We describe the first case of doubly
heterozygous HbSD-Punjab from Malaysia managed with
regular blood transfusion at the age of one. This case
highlights the propensity for occurrence of rare phenotypes
within our multi-ethnic population and emphasises the
importance of accurate genotyping to avoid erroneous
counselling, and to plan an effective patient management
strategy before complication evolves.
4.The acetone crude extract of Quercus infectoria (Olivier) galls alters pH of the digestive vacuole of the malaria parasite, Plasmodium falciparum
Nik Mat Zin, N.N.I. ; Ibrahim, N. ; Zakaria, Y. ; Abu-Bakar, N.
Tropical Biomedicine 2021;38(No.2):40-47
The reduced efficacy of the mainstay antimalarial drugs due to the widespread of drugresistant
Plasmodium falciparum has necessitated efforts to discover new antimalarial drugs
with new targets. Quercus infectoria (Olivier) has long been used to treat various ailments
including fever. The acetone extract of the plant galls has recently been reported to have a
promising antimalarial activity in vitro. This study was aimed to determine the effect of the
Q. infectoria gall acetone crude extract on pH of the digestive vacuole of Plasmodium falciparum.
A ratiometric fluorescent probe, fluorescein isothiocyanate-dextran (FITC-dextran) was used
to facilitate a quantitative measurement of the digestive vacuole pH by flow cytometry. Mid
trophozoite stage malaria parasites grown in resealed erythrocytes containing FITC-dextran
were treated with different concentrations of the acetone extract based on the 50% inhibitory
concentration (IC50). Saponin-permeabilized parasites were analyzed to obtain the ratio of
green/yellow fluorescence intensity (Rgy) plotted as a function of pH in a pH calibration
curve of FITC-dextran. Based on the pH calibration curve, the pH of the digestive vacuole of
the acetone extract-treated parasites was significantly altered (pH values ranged from 6.35-
6.71) in a concentration-dependent manner compared to the untreated parasites (pH = 5.32)
(p < 0.001). This study provides a valuable insight into the potential of the Q. infectoria galls
as a promising antimalarial candidate with a novel mechanism of action.
5.Steroids from Diplazium esculentum: Antiplasmodial activity and molecular docking studies to investigate their binding modes
Safar, H.F. ; Ali, A.H. ; Zakaria, N.H. ; Kamal, N. ; Hassan, N.I. ; Agustar, H.K. ; Talip, N. ; Latip, J.
Tropical Biomedicine 2022;39(No.4):552-558
Diplazium esculentum is an edible fern commonly consumed by the local community in Malaysia either
as food or medicine. Isolation work on the ethyl acetate extract of the stem of D. esculentum resulted in
the purification of two steroids, subsequently identified as stigmasterol (compound 1) and ergosterol5,8-endoperoxide (compound 2). Upon further testing, compound 2 displayed strong inhibitory activity
against the Plasmodium falciparum 3D7 (chloroquine-sensitive) strain, with an IC50 of 4.27±1.15 µM,
while compound 1 was inactive. In silico data revealed that compound 2 showed good binding affinity
to P. falciparum-Sarco endoplasmic reticulum calcium-dependent ATPase (PfATP6); however, compound
1 did not show an antiplasmodial effect due to the lack of a peroxide moiety in the chemical structure.
Our data suggested that the antiplasmodial activity of compound 2 from D. esculentum might be due
to the inhibition of PfATP6, which resulted in both in vitro and in silico inhibitory properties.
6.COMPARISON OF PATHOGENESIS OF P. BERGHEIINFECTION IN MOUSE AND RAT MODELS
Chin VK ; Chong WC ; Nordin N ; Lee TY ; Zakaria ZA ; Hassan H ; Basir R
Journal of University of Malaya Medical Centre 2019;22(2):4-12
Background: The cytokine cascade in the immunopathogenesis of malaria infection had been widely studied. However, their specific association with survival and severe infection remained obscure.Methods: Thestudy investigated the cytokine profiles and histopathological features of malaria in the severe infection and survival models by using male ICR mice and male Sprague Dawley rats respectively.Results: The severe model, the infected ICR mice, exhibited a high parasitemia with 100% mortality after peak parasitemia at day 5 post-infection. The survival model, the infected Sprague Dawley rats, showed mild parasitemia with full recovery by day 14 of infection. Both severe and survival models showed similar histopathological severity during peak parasitemia. The severe model produced highly elevated levels of pro-inflammatory cytokines, TNF-α and IL-1α, and low levels of the anti-inflammatory cytokine, IL-4; while the survival model showed low levels of TNF-α and IL-1α with high levels of IL-4.Conclusion: There were differences in the pathogenesis of the severe and survival models of malaria infection. These could be a basis for immunotherapy of malaria in the future
7.Management of Organochlorine Exposure to Health Risks in Asia – A Review
Muhammad Azmi Maruf ; R. Azizah ; Lilis Sulistyorini ; Zainul Amiruddin Zakaria ; Najihah Hanisah Marmaya ; Aditya S. Pawitra ; Arif Sumantri ; Siti N. A. Jauharoh
Malaysian Journal of Medicine and Health Sciences 2021;17(No.4):332-340
Organochlorine organic pesticides used on a large scale still pose a great health hazard to humans and animals.
Organochlorine pesticides contribute to reduced disease, higher yields and increased production. This research was
to review various articles on management of organochlorine exposure and health risks. This research used multiple
search engines (Scholar, PubMed). A few significant keywords were chosen to discover considers that fit this theme.
Organochlorine as Persistent Organic Pollutants are difficult to remove from the environment. There are several
health-causing effects of organochlorine most of which are chronic diseases (i.e., pulmonary function, cancer, reproductive issue). Organochlorine control in the environment is needed to reduce health effects, especially in farming
communities, personal protective equipment including masks and gloves is also necessary. Local government may
also promote and doing a prevention program from the danger of the use of pesticides in agriculture.