1.Environmental and Occupational Health Impact of Bauxite Mining in Malaysia: A Review
Lee KYa, Ho LY ; Tan KH ; Tham YY ; Ling SP ; Qureshi AM ; Ponnudurai T ; Nordin R ; Jeffrey Cheah
The International Medical Journal Malaysia 2017;16(2):137-150
In the perspective of recent bauxite mining in Malaysia, this review aims to identify the potential
environmental and health impacts on miners and surrounding communities. The environmental issues of
bauxite mining include, air, water and soil pollution due to bauxite dust; leaching of bauxite into water
sources resulting in reduced soil fertility as well as affecting agricultural food products and aquatic life.
Bauxite occupational exposure affects the health of miners, and has negative consequences on the health of
surrounding communities, such as increased respiratory symptoms, contamination of drinking water, other
potential health risks from ingestion of bauxite and heavy metals, including noise-induced hearing loss and
mental stress. This review discusses the processes of bauxite mining, its constituents and residual trace
elements, and their impact on the environment and health of exposed workers and communities. It also
explores the Malaysian legal requirements and standards of occupational exposure to bauxite.
2.Maternal Obesity and Its Associated Factors and Outcomes in Klang Valley, Malaysia: Finding from National Obstetric Registry
Rohana Abdul Jalil ; Nurul Farehah Shahrir ; J. Ravichandran R Jeganathan ; Shamala Devi Karalasingam ; Noraihan Mohd Nordin ; Mohamad Farouk Abdullah ; Nadiah Sa&rsquo ; at
Malaysian Family Physician 2021;16(3):56-67
Introduction: Maternal obesity presents significant health risks to mothers and their fetuses. This study aimed to determine the proportion, associated factors and outcomes of maternal obesity among pregnant women in Klang Valley, Malaysia.
Methods: A retrospective cross-sectional study was conducted between January 2018 and March 2018 using secondary data from the Malaysian National Obstetric Registry (NOR) for the year 2015. All pregnant women with first-trimester booking at 12 weeks and below that were registered with the NOR and met the inclusion and exclusion criteria were included in the study. Descriptive statistics and multiple logistic regression analysis were used. Data were analysed using SPSS version 22.0. A total of 2113 respondents were included in this study to determine the proportion, associated factors and outcomes of maternal obesity. Regarding the univariate and multivariate analyses, respondents were classified into two groups: normal and obese. The obese group comprised overweight and obese mothers. The underweight group was excluded in the subsequent analysis.
Results: Out of the 2113 respondents, 7.1% were underweight, 41.7% were of normal weight, 28.6% were overweight, 15.9% were in obese class I, 4.6% were in obese class II, and 2.1% were in obese class III according to the WHO (1995) reference. However, when the MOH (2003) cutoff point was used, there was a marked increase in the proportion of respondents in the overweight categories by 2.7% and obesity class I by 12.8%. The Indian (AdjOR 2.06, 95% CI: 1.11, 3.83, p=0.021) and Malay (AdjOR 1.75, 95% CI: 1.02, 3.00, p=0.040) ethnicities, as well as both multiparity (AdjOR 1.46, 95% CI: 1.23, 1.73, p <0.001) and grand multiparity (AdjOR 2.41, 95% CI: 1.78, 3.26, p <0.001), were significantly associated with maternal obesity. There were significant association between maternal obesity with hypertensive disorder in pregnancy (p=0.025), caesarean section delivery (p=0.002) and macrosomic infant (p <0.001).
Conclusion: The identification of risk factors for maternal obesity is important to facilitate intervention programmes focused on improving the pregnancy outcomes for a high-risk group of women.
3.Interleukin-27 exhibited anti-inflammatory activity during Plasmodium berghei infection in mice.
Fazalul Rahiman, S S ; Basir, R ; Talib, H ; Tie, T H ; Chuah, Y K ; Jabbarzare, M ; Chong, W C ; Mohd Yusoff, M A ; Nordin, N ; Yam, M F ; Abdullah, W O ; Abdul Majid, R
Tropical Biomedicine 2013;30(4):663-80
Interleukin-27 (IL-27) has a pleiotropic role either as a pro-inflammatory or anti-inflammatory cytokine in inflammatory related diseases. The role and involvement of IL-27 during malaria was investigated and the effects of modulating its release on the production of major inflammatory cytokines and the histopathological consequences in major affected organs during the infection were evaluated. Results showed that IL-27 concentration was significantly elevated throughout the infection but no positive correlation with the parasitaemia development observed. Augmentation of IL-27 significantly elevated the release of anti-inflammatory cytokine, IL-10 whereas antagonising and neutralising IL-27 produced the opposite. A significant elevation of pro-inflammatory cytokines (IFN-γ and IL-6) was also observed, both during augmentation and inhibition of IL-27. Thus, it is suggested that IL-27 exerts an anti-inflammatory activity in the Th1 type response by signalling the production of IL-10 during malaria. Histopathological examination showed sequestration of PRBC in the microvasculature of major organs in malarial mice. Other significant histopathological changes include hyperplasia and hypertrophy of the Kupffer cells in the liver, hyaline membrane formation in lung tissue, enlargement of the white and red pulp followed by the disappearance of germinal centre of the spleen, and tubular vacuolation of the kidney tissues. In conclusion, it is suggested that IL-27 may possibly acts as an anti-inflammatory cytokine during the infection. Modulation of its release produced a positive impact on inflammatory cytokine production during the infection, suggesting its potential in malaria immunotherapy, in which the host may benefit from its inhibition.
4. An update on Gardneralla vaginalis associated bacterial vaginosis in Malaysia
Nada Khairi YOUNUS ; Syafinaz Amin NORDIN ; Narcisse MARY ; Vasantha Kumari NEELA ; Renu GOPINATH ; Ravindran JEGASOTHY ; Alex VAN BELKUM
Asian Pacific Journal of Tropical Biomedicine 2017;7(9):831-835
Objective To update the status of Gardnerella vaginalis (G. vaginalis) as a causative agent of bacterial vaginosis (BV) in Malaysia and to define its epidemiology, metronidazole resistance and virulence properties. Methods It is a single-centre (Gynaecology clinic at the Hospital Kuala Lumpur, Malaysia) prospective study with laboratory-based microbiological follow up and analyses. Vaginal swabs collected from the patients suspected for BV were subjected to clinical BV diagnosis, isolation and identification of G. vaginalis, metronidazole susceptibility testing, vaginolysin and sialidase gene PCR, Piot's biotyping and amplified ribosomal DNA restriction analysis (ARDRA) genotyping. Results Among the 207 patients suspected for BV, G. vaginalis was isolated from 47 subjects. G. vaginalis coexisted with Trichomonas vaginalis and Candida albicans in 26 samples. Three G. vaginalis isolates were resistant to metronidazole. Biotyping revealed 1 and 7 as the common types. ARDRA genotype II was found to be more common (n = 22; 46%) than I (n = 12; 25.53%) and III (n = 13; 27.6%). All genotype I and III isolates carried the sialidase gene, while 91.6% and 84.6% contained the vaginolysin gene. Genotype I was significantly associated with post-gynaecological surgical complications and abortions (P = 0.002). Conclusions The existence of pathogenic G. vaginalis clones in Malaysia including drug resistant strains should not be taken lightly and needs to be monitored as these may bring more complications especially among women of child bearing age and pregnant women.
5.Evaluation of in vitro antifungal effects of synthetic and herbal mouth rinses on oral Candida albicans and Candida glabrata
Nordin, R. ; Roslan, M.A. ; Fathilah, A.R. ; Ngui, R. ; Musa, S.
Tropical Biomedicine 2022;39(No.3):302-314
Mouth rinses which function as breath fresheners, medicaments, and antiseptics can also deliver oral
therapeutic agents. This study evaluated and compared the antifungal effects of synthetic and herbal
mouth rinses on oral C. albicans and C. glabrata via disk diffusion, minimal inhibition concentration (MIC),
minimum fungicidal concentration (MFC), time-kill assay, and growth profile tests. The four chemical
mouth rinses, namely Brand O (A), Brand M (B), Brand H (C), and Brand B (D) used in the study showed
positive antifungal activity in these two species. The average diameter of the inhibition zones obtained
from the disk diffusion test was higher in mouth rinse B (C. albicans = 12.0 ± 0.9 mm, C. glabrata =
13.5 ± 0.8 mm) compared to those in C, A and D. Both Candida species exhibited similar MIC and MFC
values, ranging from 1.63 ± 0.5 to 18.75 ± 0.0 µg/mL and 6.51 ± 2.01 to 50.00 ± 9.36 µg/mL, respectively.
These synthetic mouth rinses had efficient killing activity eliminating 50% of the growing population
of both Candida spp. following 15 seconds exposure time. Analyses of the growth profile curves showed
that mouth rinses B and A resulted in rapid growth depletion of both Candida spp. Meanwhile, three
herbal mouth rinses, namely Brand S (E), Brand C (F), and Brand P (G), were less effective against C.
albicans and C. glabrata. Mouth rinses B and A contained cetylpyridinium chloride and chlorhexidine,
respectively, and could be an effective alternative for controlling and preventing oral candidiasis.
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.Time-kill and post-antibiotic effect of colistin at different static concentrations in in vitro Acinetobacter baumannii
Rasidin, R.S.M. ; Suhaili, Z. ; Mohamed, A.F.S. ; Hod, R. ; Neela, V. ; Amin-Nordin, S.
Tropical Biomedicine 2020;37(No.2):471-481
Nosocomial infection caused by Acinetobacter baumannii is common among immunocompromised patients. Treatment strategy is limited due to rapid resistance development and lack of novel antibiotic. Colistin has been the last line therapy with good in vitro activity against infections caused by multi-drug resistance A. baumannii. However, pharmacological updates are required to support dosing optimisation. This study aimed to determine the time-kill kinetic and resistance development after antibiotic exposure as well as post-antibiotic effect of colistin at different static concentrations in in vitro A. baumannii system. The static in vitro time-kill and post-antibiotic effect experiments were conducted against two clinical isolates as well as one reference isolate ATCC 19606. Time-kill and postantibiotic effect were studied at colistin concentrations ranging from 0.25MIC to 16.0MIC and 0.5MIC to 4.0MIC, respectively. Post-exposure resistance development was examined in time-kill study. Killing activity and post-antibiotic effect were in a concentration-dependent manner. However, delayed killing activity indicates colistin tolerance. Development of resistance after exposure was not detected except for the ATCC 19606 strain. Dosing suggestion based on the observations include administration of supplemental dose 3 MIU at 12 hours after loading dose, administration of maintenance dose 9 MIU in two divided doses and application of extended interval in renal adjustment dose. However, the information is applicable for non-colistin-heteroresistance A. baumannii with colistin MIC < 1.0 mg/L. As for heteroresistance and strain with colistin MIC > 1.0 mg/L, combination therapy would be the more appropriate treatment strategy.
8.Influence of citronella and chlorpyrifos on Chrysomya megacephala (Fabricius) and Chrysomya rufifacies (Macquart) (Diptera: Calliphoridae) infesting rabbit carcasses
Denis, C.I. ; Nordin, N.H. ; Azman, A.R. ; Abdul Wahab, R. ; Ismail, D. ; Omar, B. ; Mahat, N.A.
Tropical Biomedicine 2018;35(3):755-768
Influence of citronella and chlorpyrifos on oviposition and duration for completing
life cycles for Chrysomya megacephala and Chrysomya rufifacies infesting decomposing
rabbit carcasses was studied. Male rabbit carcasses (n = 12) were equally divided into
control, citronella- and chlorpyrifos–treated groups, and left to decompose for 14 consecutive
days. C. megacephala was the first necrophagous fly oviposited in all control and citronellatreated
carcasses followed by C. rufifacies. Although initial oviposition of C. megacephala
was delayed (4-6 hours) in citronella-treated carcasses (P < 0.05), prolongation in completing
its life cycle was not observed. Neither delayed initial oviposition nor prolonged life cycle for
C. rufifacies in citronella-treated carcasses was observed. Oviposition was delayed for
chlorpyrifos-treated carcasses (0.42 g/L), and eclosion of eggs remained unsuccessful. The
findings deserve consideration because these chemicals are easily accessible and can be
used by cunning criminals to confuse forensic entomologists while estimating minimum postmortem
interval.
9.Inhibition of Activin A suppressed tumor necrosis factor-α secretion and improved histopathological conditions in malarial mice
Chin, V.K. ; Tie, T.H. ; Abd Majid, R. ; Hassan, H. ; Nordin, N. ; Abas, R. ; Basir, R.
Tropical Biomedicine 2021;38(No.1):187-204
Malaria infection still remains as one of the most prominent parasitic diseases afflicting
mankind in tropical and subtropical regions. The severity of malaria infection has often
been associated to exuberant host immune inflammatory responses that could possibly
lead to severe immunopathological conditions and subsequent death of host tissues. Activin
A is a protein belonging to the transforming growth factor-beta (TGF-β) family that regulates
multiple physiological processes and pathological-associated diseases. The biological
roles of activin A have been associated with manipulation of inflammation-related processes
and modulation of host immune responses. This implies that activin A protein could play a
role in malaria pathogenesis since malaria infection has been closely linked to severe
immune responses leading to death, However, the actual in vivo role of activin A in malaria
infection remains elusive. Hence, this study was undertaken to investigate the involvement
of activin A in malaria infection as well as to assess the modulating effects of activin A on
the cytokine releases (TNF-α, IFN-γ and IL-10) and histopathological changes in major affected
organs (kidney, liver, lung, brain and spleen) in malarial mice infected with Plasmodium
berghei ANKA. Our results showed that the concentrations of plasma activin A were significantly
increased in malarial mice throughout the study periods. Also. the systemic activin A level
was positively correlated with malaria parasitemia. This indicates that activin A could play
a role in malaria pathogenesis and malaria parasitemia development. Plasma TNF-α,
IFN-γ and IL-10 cytokine levels were significantly increased in malarial mice at day-5 post
infection, suggesting that these cytokines attributed to severe malaria pathogenesis.
Histopathological features such as sequestration of parasitized red blood cells (pRBCs)
and hemozoin formation were amongst the most common pathological conditions observed
in tissues of major affected organs (kidney, liver, lung, brain and spleen) in malarial mice.
Neutralization of activin A production via recombinant mouse activin RIIA Fc chimera (rmActivin
RIIA Fc chimera) had significantly reduced the parasitemia levels in malarial mice. The
release of TNF-α cytokine was significantly reduced as well as the sequestration of
parasitized pRBCs and hemozoin formation in major affected organs in malarial mice were
also alleviated following inhibition of activin A production. Overall, this preliminary study
suggests that activin A could play an immune modulation role in malaria pathogenesis
through modulation of TNF-α release that benefits host from severe pathological destructions
provoked by intensified inflammatory responses. Further studies are warranted to elucidate
the precise mechanism of immune modulation mediated by activin A and its associated
immune-modulation mediators in regulating the inflammatory responses elicited during
the course of malaria infection.
10.Development patterns of necrophagous flies infesting rabbit carcasses decomposing in Mount Kapur Cave and its surrounding primary forest in Kuching, Sarawak
Nordin, N.H. ; Ahmad, U.K. ; Abdul Rahim, N.A. ; Kamaluddin, M.R. ; Ismail, D. ; Muda, N.W. ; Abdul Wahab, R. ; Mahat, N.A.
Tropical Biomedicine 2020;37(No.2):333-356
In addition to the scarcity of forensic entomology baseline data on oviposition of necrophagous insects and completion of their life cycles in the Borneo region, similar data derived from caves remain unreported. Since entomological baseline data can differ from one biogeoclimatic region to another, the lack of such data would limit the practical values of applying entomological evidence in estimating minimum postmortem interval (mPMI). Therefore, this present research that investigated oviposition and completion of life cycles of necrophagous flies infesting rabbit carcasses decomposing in Mount Kapur Cave and its surrounding forest habitat in Kuching, Sarawak merits forensic consideration. In general, 13 taxa of necrophagous flies were identified viz. Hypopygiopsis violacea, Hypopygiopsis fumipennis, Hemipyrellia ligurriens, Hemipyrellia tagaliana, Chrysomya megacephala, Chrysomya villeneuvi, Chrysomya rufifacies, Chrysomya chani, Chrysomya pinguis, Chrysomya nigripes, Ophyra spinigera and Ophyra chalcogaster, as well as unidentified Sarcophagidae. In addition, Hyp. violacea and Hyp. fumipennis were the two earlier necrophagous flies that oviposited in all rabbit carcasses decomposing in both habitats. While all these necrophagous flies were observed infesting carcasses in Mount Kapur Cave, Hem. ligurriens and Hem. tagaliana were not found infesting carcasses in the surrounding forest habitat. Complete life cycles for six and five different necrophagous fly species were successfully observed in Mount Kapur Cave and its surrounding forest habitat, respectively. Significant delay in oviposition, as well as longer durations for completing the life cycles in several necrophagous fly species were observed in Mount Kapur Cave when compared with those of surrounding forest habitat (p < 0.05). These findings deserve consideration as the first ever forensic empirical baseline data on oviposition and completion of life cycles for necrophagous flies in Sarawak as well as in a cave habitat, in view of its practical values for estimating mPMI for forensic practical caseworks.