Browse publications by year: 2021

  1. Choudhari OK, Rani A, Kampani G, Kaur C, Sengupta A
    Malays J Med Sci, 2021 Dec;28(6):32-41.
    PMID: 35002488 DOI: 10.21315/mjms2021.28.6.4
    Background: Genetic and environmental factors, along with hypertension, diabetes mellitus and smoking cause accelerated atherosclerosis and, eventually, stroke. Matrix metalloproteinase-9 (MMP-9) are inflammatory mediators of the endoproteinase family, and their polymorphism and methylation are associated with the development of atherosclerosis and stroke. This study explores this association in the Indian population.

    Objective: To study the association of MMP gene polymorphism and methylation with the risk of stroke.

    Methods: A case-control study was conducted on 100 admitted patients (both genders) diagnosed with ischaemic stroke. Another 100 healthy subjects, not suffering from any chronic illness or stroke, were taken as controls. All participants were genotyped for rs3918242 (MMP-9) by polymerase chain reaction (PCR) and restriction fragment length polymorphism. Methylation of the MMP-9 gene-promoter region was assessed by methylation-specific PCR.

    Results: The case (mean age = 61.3 ± 7.36 years old) and control (mean age = 60.68 ± 7.1 years old) groups were age-matched. Among cases, 61 patients were smokers, 55 were diabetic and 53 were hypertensive. A significant risk of ischaemic stroke was associated with the CT genotype (adjusted odds ratio [aOR] = 7.09; P < 0.001), TT genotype (aOR = 19.75; P < 0.001) and T allele (aOR = 10.71; P < 0.001). MMP-9 methylation decreased the risk of stroke (aOR = 0.23; P < 0.001).

    Conclusion: MMP-9 gene-1562C/T polymorphism (SNP rs3918242) (single-nucleotide polymorphism [SNP] rs3918242) is a potential marker to predict ischaemic stroke and constitutes a significant proportion of the general population. Its polymorphism predisposes to ischaemic stroke, while its methylation is protective.

  2. Kho GS, Kandasamy R, Bujang MA, Swammy M, Mustapha M, Abdullah JM
    Malays J Med Sci, 2021 Dec;28(6):42-54.
    PMID: 35002489 DOI: 10.21315/mjms2021.28.6.5
    BACKGROUND: Nitric oxide (NO) is involved in a multitude of physiological processes in the central nervous system (CNS). Given the ubiquitous nature of NO and its involvement in various vital processes, nitric oxide metabolite (NOx) has been investigated as a biomarker in CNS diseases. This study aims to investigate the ratio of NOx levels and serum in cerebrospinal fluid (CSF) in patients with spontaneous subarachnoid haemorrhage (SAH). The associations among these markers with clinical outcomes were also studied.

    METHODS: A prospective cohort study was conducted over a 2-year period (May 2013-May 2015) to investigate the levels of NOx in the CSF and serum of patients with radiologically confirmed aneurysmal SAH. NOx samples and all relevant data were collected from the patients on admission and serially over 5 days. On admission, NOx levels were compared between the groups of patients, who were divided as per the World Federation Neurosurgeons Score (WFNS) grading scale, Fisher scale, occurrence of vasospasm on transcranial doppler (TCD), and Glasgow outcome scale (GOS) upon discharge and at 6 months follow-up. The ratios of CSF-to-serum were calculated and correlated with SAH severity and the outcome parameters listed above.

    RESULTS: The patients (N = 40) had a mean (SD) age of 58.2 (11.8) years old. The majority (65%) had a higher severity of SAH (WFNS score 3-5). On evaluation of the CT scan findings, 74% had outcomes equivalent to 4 on the Fisher scale. Vasospasm was detected via TCD in nearly half (45%) of the cohort during the study period; 80% were noted to have a poor outcome (GOS 1-3) at discharge; this persisted at 6 months follow-up. Comparison of NOx levels in the CSF/serum ratio was based on the incidence of vasospasm and severity of outcome (GOS) for day-1 and day-4. Statistically significant results were evident for patients with better outcomes, high severity grading, and the presence of vasospasm (P-values: 0.031, 0.034 and 0.043, respectively).

    CONCLUSION: Elevated NOx levels in CSF and serum and reductions in the ratio of NOx in CSF/serum were found to be associated with severity, occurrence of vasospasm and clinical outcome in aneurysmal SAH patients. This indicates the possible role of NOx as a biomarker to assess severity and prognosis in patients with SAH.

  3. Abdul Rahim R, Eng Hong G, Nik Ismail NA, Zakaria R
    Malays J Med Sci, 2021 Dec;28(6):55-63.
    PMID: 35002490 DOI: 10.21315/mjms2021.28.6.6
    Background: Benign prostatic hyperplasia (BPH) is associated with severe lower urinary tract symptoms (LUTS). The severity of LUTS is assessed by the International Prostate Symptoms Score (IPSS). Prostate artery embolisation (PAE) is a newly available method for combating LUTS. This study aims to assess the outcomes of PAE in reducing LUTS and prostate volume in patients with BPH.

    Methods: Patients diagnosed with BPH with severe LUTS who had undergone PAE were included. Their IPSS score was ≥ 20 despite medical therapy. PAE was performed via the unilateral femoral artery using various types of embolic material. Bilateral or unilateral embolisation of the prostate artery was considered a technical success. The severity of LUTS pre- and post-PAE were assessed using IPSS while prostate volume pre- and post-PAE were assessed by ultrasound and magnetic resonance imaging (MRI).

    Results: Ninety percent of patients had technical success and one required transurethral resection of the prostate (TURP). The mean IPSS reduction at the final follow-up was 12.9 (P < 0.028). The mean reduction of prostate volume at the last follow-up by ultrasound was 114.99 mL (P < 0.028) and by MRI was 29.17 mL (P < 0.028).

    Conclusion: PAE is safe and effective in reducing severe LUTS and prostate gland volume in BPH patients.

  4. Zarei Yazdeli M, Ghazaei C, Tasallot Maraghi E, Bakhshi A, Shukohifar M
    Malays J Med Sci, 2021 Dec;28(6):64-75.
    PMID: 35002491 DOI: 10.21315/mjms2021.28.6.7
    BACKGROUND: Chemical preservatives are now used in various foods to increase shelf life and maintain quality instead of its natural extracts with anti-bacterial properties from plants can be used. Hence this research was planned to evaluate and study the synergistic antibacterial effect of the methanolic extracts of Dracocephalum kotschyi (D. kotschyi) and Trachyspermum ammi (T. ammi) against standard pathogenic bacteria like: Pseudomonas aeruginosa (P. aeruginosa), Shigella dysenteriae (S. dysenteriae), Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus).

    METHODS: The methanolic extract of D. kotschyi and T. ammi was prepared by the Soxhlet method. The minimum inhibitory concentration (MIC) of this methanolic extracts were determined by the microdilution method. Thus, by determining the amount of fractional inhibitory concentration index (FICI), the interaction between the methanolic extracts of D. kotschyi and T. ammi on the pathogenic bacteria was determined.

    RESULTS: In this study, the MIC of the extracts of D. kotschyi and T. ammi on the pathogen; S. aureus was equal to 6.25 mg/mL and 12.5 mg/mL for S. dysenteriae, E. coli and P. aeruginosa. Hence, the combination of methanolic extracts of these plants shows a synergistic antibacterial effect (FICI < 0.5), on all tested pathogenic microorganisms was proved.

    CONCLUSION: Due to the antimicrobial synergistic effect and cost-effective production process of methanolic extracts of D. kotschyi and T. ammi, they are used as natural preservatives and flavouring agents to preserve foods.

  5. Azri N, Norsa'adah B, Hassan NB, Naing NN
    Malays J Med Sci, 2021 Dec;28(6):76-87.
    PMID: 35002492 DOI: 10.21315/mjms2021.28.6.8
    Background: Insulin therapy is necessary for patients with type 2 diabetes mellitus (T2DM) to reach the targeted glycaemic level and prevent complications. This study aimed to determine the proportion of adherence to insulin therapy and the associated factors in patients with T2DM.

    Methods: A cross-sectional study was conducted among 249 patients with T2DM who had been on insulin therapy for at least 2 months in primary care centres of the Ministry of Health in Klang, Malaysia. A validated insulin adherence questionnaire for diabetes mellitus (DM) was used to assess insulin adherence. Data on the sociodemographic characteristics, disease-related factors, treatment-related factors and clinical parameters were extracted from medical records and interviews with patients.

    Results: The adherence to insulin therapy was 8.43%. The factors associated with insulin adherence were self-monitoring of blood glucose (SMBG) (adjusted odds ratio [AOR]: 5.39; 95% confidence interval (CI): 1.20, 24.13; P = 0.028), exercise (AOR: 3.38; 95% CI: 1.37, 10.03; P = 0.029) and the number of daily insulin injections (AOR: 1.63; 95% CI: 1.09, 2.44; P = 0.017).

    Conclusion: The adherence to insulin therapy in primary health care centres in Malaysia was very poor. Patients who practiced SMBG, exercised and frequent daily insulin injections were significantly more adherent to insulin therapy.

  6. Lim OW, Liew HH, Eng XR, Yong CK, Lim LH
    Malays J Med Sci, 2021 Dec;28(6):88-99.
    PMID: 35002493 DOI: 10.21315/mjms2021.28.6.9
    Background: Raised blood pressure, also known as hypertension (HPT), has been a distressing health concern among Malaysians. An upward trend is found on the prevalence of newly-diagnosed HPT, contributing to the high number of overall hypertensive patients in Malaysia. To understand the cause and reduce the economic burden caused by HPT, current research aims to examine the dependency among sociodemographic and behavioural determinants of newly-diagnosed HPT among Malaysians.

    Methods: The current study uses secondary data from the Fifth National Health and Morbidity Survey (NHMS V) 2015, a population based cross-sectional study. This study uses the Bayesian Network (BN) modelling to design and build a 'causal' model and identify potential determinants and their respective conditional probability on the prevalence of newly-diagnosed HPT among Malaysians.

    Results: This study shows that Malaysians with newly-diagnosed HPT are directly affected by the age and body mass index (BMI). Additionally, household income, sex, marital status, ethnicity, strata, education levels, occupation, fruit intake, vegetable intake, smoking status, physical activity and plain water intake indirectly affect the incidence of the newly-diagnosed HPT.

    Conclusion: These results may be helpful in implementing appropriate policies to prevent and monitor the increasing prevalence of newly-diagnosed HPT among adults in Malaysia.

  7. Aljindan RY, Alnimr AM, Al Dossary RA, Al Haddad AJ, Alturki FA, Al-Romihi NM, et al.
    Malays J Med Sci, 2021 Dec;28(6):100-107.
    PMID: 35002494 DOI: 10.21315/mjms2021.28.6.10
    Background: Pooled specimen screening for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can improve laboratory testing capacity. This study assessed the impact of pooling and retesting individual swabs on the overall detection rate and reduction in the frequency of retesting.

    Methods: One hundred respiratory swabs specimens were tested individually and in pools of three or five samples using the Cepheid's Xpert® Xpress SARS-CoV-2 test kit. The optimum number of samples per pool was calculated using the application 'A Shiny App for Pooled Testing'.

    Results: Twenty-five pools were generated from 101 samples. Out of 13 pools that contained five samples each, three pools gave true positive results. While out of the 12 pools that contained three samples each, five pools gave true positive results. Four samples gave a false negative pool result. The overall sensitivity and specificity of the assay in the pools were 66.6% and 100%, respectively. The cycle threshold was reduced in most of the pools compared to individual sample tests.

    Conclusion: The overall pooled test had a remarkable impact on laboratory resources. Yet, caution is warranted when selecting the cases for pooled testing, since the reduction in sensitivity can significantly impact and increase the risk of exposure to infection.

  8. Hashmi SI, Ah Gang GC, Sombuling A, Md Nawi NH, Megat Ahmad PH
    Malays J Med Sci, 2021 Dec;28(6):108-120.
    PMID: 35002495 DOI: 10.21315/mjms2021.28.6.11
    Introduction: The Malay autism spectrum quotient, children's version (AQ-Child) is a translated and reduced version of the autism spectrum disorder (ASD) screening instrument. The aim of this study was to test the reliability and validity of the translated Malay version of the questionnaire.

    Methods: The instrument is a 41-item Likert scale form parental questionnaire designed to screen ASD among children aged 6 years old-12 years old. It was filled out by the parents of 700 children (children with ASD = 47; typically developing children = 653) who were contacted through five special education schools and seven mainstream primary schools.

    Results: Findings showed that Malay AQ-Child has an internal consistency of 0.82 as a whole scale for 41-items. Receiver operator characteristic analysis showed that the cut score of 63 for the translated, reduced version of the AQ-Child with 41 items had 99% area (95% confidence interval [CI]) under receiver operating characteristic (ROC) curve, and sensitivity and specificity of 93% and 99%, respectively. As for factor structure, principal component analysis (PCA) showed good loading values for most of the items in the instrument.

    Conclusion: The translated version of the Malay AQ-Child for screening ASD can further facilitate the process of surveillance and early intervention for children who need it.

  9. Fadzil NA, Heong WO, Kueh YC, Phang CK
    Malays J Med Sci, 2021 Dec;28(6):121-128.
    PMID: 35002496 DOI: 10.21315/mjms2021.28.6.12
    Background: Among healthcare workers, nurses have a particularly high risk of stress. Stressful conditions in the workplace increase the possibility of burnout and psychological distress. Short mindfulness-based interventions can help to decrease stress, anxiety and depression. This study aimed to explore the effectiveness of a mindfulness-based intervention in reducing perceived stress, anxiety and depression among public teaching hospital staff nurses.

    Methods: Thirty-five nurses from various specialities were recruited from Hospital Universiti Sains Malaysia (HUSM). The intervention comprised a 1-day brief mindfulness-based intervention workshop and 1 h group practice session each month for 3 months together with daily follow-up via WhatsApp group. All the participants completed a self-administered sociodemographic questionnaire validated for use in a Malay population. The Depression, Anxiety and Stress Scale 21 (DASS 21) and Perceived Stress Scale 10 (PSS 10) were used to measure perceived stress, anxiety and depression before the intervention, and 3 months later upon completion of the intervention.

    Results: There was a statistically significant reduction in the scores for stress perception (95% confidence interval [CI]: 0.06, 2.92; P = 0.04) and anxiety (95% CI: 0.06, 2.34; P = 0.04) post-intervention.

    Conclusion: A brief mindfulness-based intervention was effective in reducing perceived stress and anxiety among nurses.

  10. Abdullah FC, Zakaria Z, Thambinayagam HC, Kandasamy R, Alias A, Abu Bakar A, et al.
    Malays J Med Sci, 2021 Dec;28(6):129-185.
    PMID: 35002497 DOI: 10.21315/mjms2021.28.6.13
    The history of neurosurgery in Malaysia traces back to 1962 and is filled with stories of vibrant and humble neurosurgeons who have dedicated their life to patients and professions. The early development of neurological and neurosurgical services begins from the establishment of the neurosurgery unit at Hospital Kuala Lumpur (HKL), followed by the foundation of the Tunku Abdul Rahman Neuroscience Institute (IKTAR). Due to the exponentially increased demand for the care of neurosurgical patients, many universities and government hospitals have opened their neurosurgical units. In 2001, the formal residency training programme (USM Masters in Neurosurgery) started and since then has produced qualified neurosurgeons that empowered and shaped the present generation. The formation of the Neurosurgical Association of Malaysia (NAM) is another turning point towards bidirectional collaboration with the World Federation of Neurosurgical Societies (WFNS). Many opportunities were created for educational activities and the expansion of subspecialties in neurosurgery. This article describes the impact of the past neurosurgeons and the endeavors that they had gone through; the present neurosurgeons who pioneered the current neurosurgical services in Malaysia, and the future neurosurgeons that will continue the legacy and bring neurosurgery further ahead in this country.
  11. Zulkifli KK, Tan PO, Mustaffa N, Chuah YY, Muthukaruppan R, Ma ZF, et al.
    Malays J Med Sci, 2021 Dec;28(6):186-193.
    PMID: 35002498 DOI: 10.21315/mjms2021.28.6.14
    Digestive disorder symptoms in COVID-19 may be similar in form to post-infectious functional gastrointestinal disorder (PI-FGID). To cause clinical effects, SARS-CoV-2 must reach the bowels and gastric hypochlorhydria may facilitate such transit. Asian elderly are predisposed to greater infection rate and severity of COVID-19, and the high prevalence of gastric atrophy and intake of proton-pump inhibitor in this aged group might explain the risk. Persistence shedding of SARS-CoV-2 in stools indicates that faecal transmission should not be disregarded. Gut involvement in COVID-19 is mediated by angiotensin-converting enzyme 2 (ACE2) receptor, which serves as the entry point for SARS-CoV-2 in the small bowel. ACE2 dysregulation has an impact on the homeostasis of gut microbiota and altered inflammatory response. Liver injury is variable in COVID-19 and is likely a result of by-stander effects rather than actual viropathic process. Further research is needed to understand if gut involvement is a cause or effect of SARS-CoV-2.
  12. Pooke TG, Kioh SH, Lee Y
    J Chiropr Humanit, 2021 Dec;28:1-8.
    PMID: 35002572 DOI: 10.1016/j.echu.2021.09.003
    Objective: This study aimed to explore the value of interprofessional learning in developing interprofessional relationships, as perceived by medical students participating as simulated patients for chiropractic students.

    Methods: A cross-sectional study of university medical students, using an online survey and interview sessions, was conducted at the International Medical University, Malaysia, from July 2020 to October 2020. Only students who had previously participated as a simulated patient within a chiropractic examination setting were included; this involved interacting with chiropractic students in observed structured clinical examinations, including history taking, physical examination or motion palpation, and adjustment setups for end-of-semester examinations. Survey responses focused on themes of interprofessional learning, with values of reduction of prejudice, increase in understanding, and improved collaborative attitude. These responses were grouped as positive, neutral, or negative based on Likert scores. Interview responses were analyzed and categorized according to the survey themes.

    Results: Fifteen male medical students aged 23 to 26 years completed the questionnaire and interview. Respondents perceived that their experience helped clarify doubts on the scope of chiropractic (66.7%), the role of a chiropractor (80%), and chiropractic professional practices (80%). A majority of respondents (80%) felt that being a simulated patient increased their willingness to learn collaboratively with chiropractic students. Most (93.3%) responded positively to being more willing to work with other health care professionals.

    Conclusion: This study showed an overall positive perception among medical students of developing interprofessional relationships with chiropractors and other health care professionals. The results suggest that opportunities for interprofessional learning between chiropractic and other health care programs may assist with the long-term goal of promoting patient-centered care.

  13. Kioh SH, Pooke TG, Chong SV
    J Chiropr Humanit, 2021 Dec;28:9-14.
    PMID: 35002573 DOI: 10.1016/j.echu.2021.09.002
    Objective: The aim of this study was to identify the number and type of indications for radiographs ordered in a chiropractic teaching clinic in Malaysia.

    Methods: A cross-sectional retrospective analysis was conducted using the medical health records of new patients who presented to the International Medical University Bukit Jalil teaching clinic for chiropractic care between August 2018 and July 2019. Data about sociodemographic characteristics, region of presenting complaint, radiography ordering rates, and referral indications were collected. We compared indications reported in the patient records with those listed in the International Medical University Chiropractic Clinical Manual. We conducted χ2 and logistic regression analysis to identify the association between radiography indications and the number of radiographs ordered.

    Results: Data were collected for 1451 patients (741 [51.1%] women and 700 [48.9%] men). The most common body region for the presenting complaint was the lumbar/pelvic region (39.0%), and the overall radiograph use rate was 2.7%, with the highest number of radiographs for the lumbar spine.

    Conclusion: For the patient files sampled in this study, the overall radiograph order rate in the International Medical University Bukit Jalil Chiropractic teaching clinic was 2.7%.

  14. Palasuberniam P, Chan YW, Tan KY, Tan CH
    Front Pharmacol, 2021;12:727756.
    PMID: 35002690 DOI: 10.3389/fphar.2021.727756
    The Samar Cobra, Naja samarensis, is endemic to the southern Philippines and is a WHO-listed Category 1 venomous snake species of medical importance. Envenomation caused by N. samarensis results in neurotoxicity, while there is no species-specific antivenom available for its treatment. The composition and neutralization of N. samarensis venom remain largely unknown to date. This study thus aimed to investigate the venom proteome of N. samarensis for a comprehensive profiling of the venom composition, and to examine the immunorecognition as well as neutralization of its toxins by a hetero-specific antivenom. Applying C18 reverse-phase high-performance liquid chromatography (RP-HPLC) and tandem mass spectrometry (LC-MS/MS), three-finger toxins (3FTx) were shown to dominate the venom proteome by 90.48% of total venom proteins. Other proteins in the venom comprised snake venom metalloproteinases, phospholipases A2, cysteine-rich secretory proteins, venom nerve growth factors, L-amino acid oxidases and vespryn, which were present at much lower abundances. Among all, short-chain alpha-neurotoxins (SαNTX) were the most highly expressed toxin within 3FTx family, constituting 65.87% of the total venom proteins. The SαNTX is the sole neurotoxic component of the venom and has an intravenous median lethal dose (LD50) of 0.18 μg/g in mice. The high abundance and low LD50 support the potent lethal activity of N. samarensis venom. The hetero-specific antivenom, Philippine Cobra Antivenom (PCAV, raised against Naja philippinensis) were immunoreactive toward the venom and its protein fractions, including the principal SαNTX. In efficacy study, PCAV was able to cross-neutralize the lethality of SαNTX albeit the effect was weak with a low potency of 0.20 mg/ml (defined as the amount of toxin completely neutralized per milliliter of the antivenom). With a volume of 5 ml, each vial of PCAV may cross-neutralize approximately 1 mg of the toxin in vivo. The findings support the potential para-specific use of PCAV in treating envenomation caused by N. samarensis while underscoring the need to improve the potency of its neutralization activity, especially against the highly lethal alpha-neurotoxins.
  15. Sontate KV, Rahim Kamaluddin M, Naina Mohamed I, Mohamed RMP, Shaikh MF, Kamal H, et al.
    Front Psychol, 2021;12:699726.
    PMID: 35002823 DOI: 10.3389/fpsyg.2021.699726
    Alcohol has been associated with violent crimes and domestic violence across many nations. Various etiological factors were linked to chronic alcohol use and violence including psychiatric comorbidities of perpetrators such as personality disorders, mood disorders, and intermittent explosive disorders. Aggression is the precursor of violence and individuals prone to aggressive behaviors are more likely to commit impulsive violent crimes, especially under the influence of alcohol. Findings from brain studies indicate long-term alcohol consumption induced morphological changes in brain regions involved in self-control, decision-making, and emotional processing. In line with this, the inherent dopaminergic and serotonergic anomalies seen in aggressive individuals increase their susceptibility to commit violent crimes when alcohol present in their system. In relation to this, this article intends to investigate the influence of alcohol on aggression with sociopsychological and neuroscientific perspectives by looking into comorbidity of personality or mood disorders, state of the mind during alcohol consumption, types of beverages, environmental trigger, neurochemical changes, and gender differences that influence individual responses to alcohol intake and susceptibility to intoxicated aggression.
  16. Linfang Z, Khalid R, Raza M, Chanrawang N, Parveen R
    Front Psychol, 2021;12:796272.
    PMID: 35002890 DOI: 10.3389/fpsyg.2021.796272
    The worth of women's entrepreneurship is accepted globally, but there is less focus on it in developing countries, and societal expectations mean women often lack the confidence to start their own business. The core purpose of this research is to investigate the influence of personality traits on women's inclination toward entrepreneurship. The personality traits are measured through the dimensions of openness, neuroticism, extraversion, conscientiousness, and agreeableness. Further, the study introduced the mediator of self-leadership on personality traits and entrepreneurial intentions of women. The study is quantitative in nature and used a questionnaire survey to collect the data by convenience sampling technique. The data was collected in the context of Pakistan, and Smart PLS was chosen for further analysis. The findings revealed the significance of the relationship between personality traits and entrepreneurial intention. Furthermore, the study also highlighted the significance of self-leadership as a mediator and proposed significant relationships. The study suggested that personality issues should be considered and used from a business perspective, and self-leadership is important for women. The study provides room for policymakers and institutes to inform educational policies to motivate women entrepreneurs for the future.
  17. Koh YS, Wong SK, Ismail NH, Zengin G, Duangjai A, Saokaew S, et al.
    Front Plant Sci, 2021;12:791205.
    PMID: 35003181 DOI: 10.3389/fpls.2021.791205
    Glutathione (GSH; γ-glutamyl-cysteinyl-glycine), a low-molecular-weight thiol, is the most pivotal metabolite involved in the antioxidative defense system of plants. The modulation of GSH on the plant in response to environmental stresses could be illustrated through key pathways such as reactive oxygen species (ROS) scavenging and signaling, methylglyoxal (MG) detoxification and signaling, upregulation of gene expression for antioxidant enzymes, and metal chelation and xenobiotic detoxification. However, under extreme stresses, the biosynthesis of GSH may get inhibited, causing an excess accumulation of ROS that induces oxidative damage on plants. Hence, this gives rise to the idea of exploring the use of exogenous GSH in mitigating various abiotic stresses. Extensive studies conducted borne positive results in plant growth with the integration of exogenous GSH. The same is being observed in terms of crop yield index and correlated intrinsic properties. Though, the improvement in plant growth and yield contributed by exogenous GSH is limited and subjected to the glutathione pool [GSH/GSSG; the ratio of reduced glutathione (GSH) to oxidized glutathione (GSSG)] homeostasis. Therefore, recent studies focused on the sequenced application of GSH was performed in order to complement the existing limitation. Along with various innovative approaches in combinatory use with different bioactive compounds (proline, citric acid, ascorbic acid, melatonin), biostimulants (putrescine, Moringa leaf extract, selenium, humic acid), and microorganisms (cyanobacteria) have resulted in significant improvements when compared to the individual application of GSH. In this review, we reinforced our understanding of biosynthesis, metabolism and consolidated different roles of exogenous GSH in response to environmental stresses. Strategy was also taken by focusing on the recent progress of research in this niche area by covering on its individualized and combinatory applications of GSH prominently in response to the abiotic stresses. In short, the review provides a holistic overview of GSH and may shed light on future studies and its uses.
  18. Mamat N, Abu A, Yusoff NR
    Zool Stud, 2021;60:e47.
    PMID: 35003341 DOI: 10.6620/ZS.2021.60-47
    Studies on Odonata have gained attention worldwide as well as locally in Malaysia. Although there is a wealth of data available to be utilized for solving taxonomic problems, ecological and behavioural research areas are more favoured than taxonomy and systematics. Thus, there are confusions over how to correctly identify closely related and sympatric species, especially in female odonates. One such example is in the genus Rhinocypha. Consequently, the present study focuses on taxonomic work, employing multi-approaches in the form of morphological (morphological diagnostics, Field Emission Scanning Electron Microscope (FESEM) and geometric morphometric analysis), applying the molecular technique. Seventeen morphological characteristics were created to differentiate between the females of Rhinocypha spp. A FESEM was used on the female's ovipositor to focus on the anal appendages and sheathing valve (V3). Also, the phylogenetic patterns expressed by COI and 16S rRNA genes, and canonical variate analysis for the wing geometric morphometric revealed three clusters that supported the distinction of the Rhinocypha group. In summary, this study effectively developed an integrated approach of classic morphological and trendy molecular, combined with FESEM microscopy techniques, which provided corroborative evidence and resolved taxonomic uncertainties.
  19. Abdul-Latiff MAB, Md-Zain BM
    Zool Stud, 2021;60:e50.
    PMID: 35003344 DOI: 10.6620/ZS.2021.60-50
    The pig-tailed macaque, Macaca nemestrina, which is distributed in Peninsular Malaysia, Thailand, Borneo, and Sumatra, has been the subject of unstable and changing taxonomic entity in the M. nemestrina group. This species is involved with a human-macaque conflict in Malaysia and at the same time played an important role in the ethnozoological culture of Malaysian. Even so, comprehensive phylogenetic, population genetics and biogeographical analysis of M. nemestrina in Malaysia are non-existent after decades of intensive research on the genus itself. Thus, we conducted the first comprehensive genetic study of M. nemestrina in Malaysia, based on three mitochondrial loci-Cytochrome b (567 bp), D-loop (398 bp), and COI (577 bp)-from 27 individuals representing Malaysia, plus an additional 26 sequences of Southeast Asian macaques from Genbank. Comparative biogeographical analysis in this study supports the positions of M. nemestrina in M. nemestrina groups as opposed to the silenus or Sulawesi groups. Results from this study also indicate that Bornean populations are the first extant lineages to separate from the other examined lineages of M. nemestrina, M. leonina, M. pagensis, and M. siberu in Southeast Asia. Molecular clock analysis suggested that M. nemestrina arrived in the Malay Peninsula about 0.32 million years ago (MYA). Our results indicate that the population of pig-tailed macaque from Perak (west Peninsular Malaysia) differs genetically based on all phylogenetic and population genetic analyses. Morphologically, Perak's pig-tailed macaque shows brighter coloration than M. n. nemestrina. Thus, we proposed a new subspecies for Perak's pig-tailed macaque as Macaca nemestrina perakensis distributed in the state of Perak, Peninsular Malaysia. This research helps resolve the taxonomic position and population genetics of pig-tailed macaque in Malaysia, which contribute directly to conservation and management of the species in Malaysia.
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