Browse publications by year: 2021

  1. Chia WY, Kok H, Chew KW, Low SS, Show PL
    Bioengineered, 2021 12;12(1):1226-1237.
    PMID: 33858291 DOI: 10.1080/21655979.2021.1910432
    The world at large is facing a new threat with the emergence of the Coronavirus Disease 2019 (COVID-19) pandemic. Though imperceptible by the naked eye, the medical, sociological and economical implications caused by this newly discovered virus have been and will continue to be a great impediment to our lives. This health threat has already caused over two million deaths worldwide in the span of a year and its mortality rate is projected to continue rising. In this review, the potential of algae in combating the spread of COVID-19 is investigated since algal compounds have been tested against viruses and algal anti-inflammatory compounds have the potential to treat the severe symptoms of COVID-19. The possible utilization of algae in producing value-added products such as serological test kits, vaccines, and supplements that would either mitigate or hinder the continued health risks caused by the virus is prominent. Many of the characteristics in algae can provide insights on the development of microalgae to fight against SARS-CoV-2 or other viruses and contribute in manufacturing various green and high-value products.
    MeSH terms: Anti-Inflammatory Agents; DNA Viruses; Humans; Problem Solving; Serologic Tests; Vaccines; Coronavirus; Coronavirus Infections; Microalgae; Pandemics
  2. McMahon DE, Semeere A, Laker-Oketta M, Byakwaga H, Mugglin C, Duda SN, et al.
    J Invest Dermatol, 2021 Apr 14.
    PMID: 33864771 DOI: 10.1016/j.jid.2021.02.758
  3. Le Ho Y, Ahmad Zaidi NA, Salleh A, Abdul Kareem BA
    J Cardiothorac Surg, 2021 Apr 17;16(1):92.
    PMID: 33865405 DOI: 10.1186/s13019-021-01458-2
    BACKGROUND: Antiphospholipid syndrome is an antibody mediated pro-thrombotic state leading to various arterial and venous thromboses. The syndrome can be either primary or secondary to other autoimmune diseases, commonly systemic lupus erythematosus. Cardiac involvement, in particular valvular disease is common in patients with antiphospholipid syndrome, occurring in about a third of these patients. Valvular diseases associated with antiphospholipid syndrome often occur as valve thickening and non-bacterial vegetation or Libman-Sacks endocarditis. Deposits of antiphospholipid immunoglobulin and complement components are commonly observed in the affected valves, suggesting an inflammatory process resulting in valvular vegetation and thickening. Libman-Sacks endocarditis has a high propensity towards mitral valve, although haemodynamically significant valvular dysfunction is rare.

    CASE PRESENTATION: We present a successful aortic valve replacement with cardiopulmonary bypass in a 48 years old lady with antiphospholipid syndrome, who has severe aortic regurgitation as a result of Libman-sacks endocarditis. Antiphospholipid antibodies were positive and the clinical data showed both negative cultures and infective parameters. Surgically resected vegetations revealed sterile fibrinous and verrucous vegetations on aortic valve. Valve replacement and the course of cardiopulmonary bypass was uneventful, and the patient was discharged well.

    CONCLUSIONS: Classically Libman-Sacks endocarditis is often and more commonly associated with autoimmune diseases such as systemic lupus erythematosus, although it can occur in both primary and secondary antiphospholipid syndrome. It is not a common entity, and it is a frequent underestimated disease as most clinicians do not routinely screen for valvular lesion in patients with antiphospholipid syndrome unless they are symptomatic. However, due to its high prevalence of cardiac involvement, clinicians should have a high index of suspicion in the attempt to minimize cardiovascular and haemodynamic complications. Valve surgery in patients with antiphospholipid syndrome carries considerable early and late morbidity and mortality, usually caused by thromboembolic and bleeding events. The perioperative anticoagulation management and haemostatic aspect of antiphospholipid syndrome present an exceptional challenges to clinicians, surgeons, anaesthetists and laboratory personnel.

    MeSH terms: Anticoagulants; Aortic Valve; Aortic Valve Insufficiency; Cardiopulmonary Bypass; Endocarditis; Female; Heart Valve Prosthesis; Hemodynamics; Hemostatics; Humans; Lupus Erythematosus, Systemic; Middle Aged; Mitral Valve; Patient Discharge; Prevalence; Antiphospholipid Syndrome; Antibodies, Antiphospholipid; Venous Thrombosis; Laboratory Personnel; Surgeons; Anesthetists
  4. Samsuddin MF, Karim J, Salim AA
    Front Psychiatry, 2021;12:571027.
    PMID: 33868035 DOI: 10.3389/fpsyt.2021.571027
    Introduction: Stress level among the caregivers is often related to caregivers' lack of knowledge and skill to care for the patients. A health education program to the caregivers is one of the important elements in increasing the knowledge and skills in managing patients at home. The specific objectives of this study were to determine caregiver's stress level in managing post total knee replacement (TKR) patients pre and post of a health education program. Materials and Methods: A clinical intervention trial design was conducted in Hospital Universiti Sains Malaysia (HUSM) with a sample size of 32 caregivers. A validated Zarit Burden Interview (ZBI) questionnaire was used to measure the stress level pre and post of the health education program on the management of patients post-TKR surgery which was adopted from Fresno Surgical Hospital in California. Results: The findings showed that there was a significant difference between pre and post level of stress (p ≤ 0.001). Conclusion: This study revealed the positive outcome of the health education program. It reduced the stress level among the caregivers in caring for their relatives with post-TKR surgery.
    MeSH terms: California; Educational Status; Health Education; Health Promotion; Hospitals; Humans; Malaysia; Surveys and Questionnaires; Caregivers; Sample Size; Arthroplasty, Replacement, Knee
  5. Yang J, Peng MY, Wong S, Chong W
    Front Psychol, 2021;12:584976.
    PMID: 33868072 DOI: 10.3389/fpsyg.2021.584976
    The COVID-19 pandemic at the beginning of 2020 has changed the conventional learning mode for most students at schools all over the world, and the e-learning at home has become a new trend. Taking Chinese college students as the research subject and drawing on the stimulus-organism-response (S-O-R) model, this paper examines the relationship between the peer referent, perceived closeness, and perceived control and the learning engagement. Using data from 377 college students who have used e-learning, this study shows that perceived closeness, perceived control, and peer referents in e-learning have a positive effect on the self-efficacy and well-being of students, thus improving students' enthusiasm for learning. Our intent is to assist researchers, instructors, designers, and others in identifying effective methods to conceptualize and measure student engagement in e-learning.
    MeSH terms: Computer-Assisted Instruction; Humans; Learning; Schools; Students; Self Efficacy; Research Subjects; Asian Continental Ancestry Group; Pandemics; Educational Personnel
  6. Feio MJ, Hughes RM, Callisto M, Nichols SJ, Odume ON, Quintella BR, et al.
    Water (Basel), 2021 Jan 31;13(3):371.
    PMID: 33868721 DOI: 10.3390/w13030371
    The biological assessment of rivers i.e., their assessment through use of aquatic assemblages, integrates the effects of multiple-stressors on these systems over time and is essential to evaluate ecosystem condition and establish recovery measures. It has been undertaken in many countries since the 1990s, but not globally. And where national or multi-national monitoring networks have gathered large amounts of data, the poor water body classifications have not necessarily resulted in the rehabilitation of rivers. Thus, here we aimed to identify major gaps in the biological assessment and rehabilitation of rivers worldwide by focusing on the best examples in Asia, Europe, Oceania, and North, Central, and South America. Our study showed that it is not possible so far to draw a world map of the ecological quality of rivers. Biological assessment of rivers and streams is only implemented officially nation-wide and regularly in the European Union, Japan, Republic of Korea, South Africa, and the USA. In Australia, Canada, China, New Zealand, and Singapore it has been implemented officially at the state/province level (in some cases using common protocols) or in major catchments or even only once at the national level to define reference conditions (Australia). In other cases, biological monitoring is driven by a specific problem, impact assessments, water licenses, or the need to rehabilitate a river or a river section (as in Brazil, South Korea, China, Canada, Japan, Australia). In some countries monitoring programs have only been explored by research teams mostly at the catchment or local level (e.g., Brazil, Mexico, Chile, China, India, Malaysia, Thailand, Vietnam) or implemented by citizen science groups (e.g., Southern Africa, Gambia, East Africa, Australia, Brazil, Canada). The existing large-extent assessments show a striking loss of biodiversity in the last 2-3 decades in Japanese and New Zealand rivers (e.g., 42% and 70% of fish species threatened or endangered, respectively). A poor condition (below Good condition) exists in 25% of South Korean rivers, half of the European water bodies, and 44% of USA rivers, while in Australia 30% of the reaches sampled were significantly impaired in 2006. Regarding river rehabilitation, the greatest implementation has occurred in North America, Australia, Northern Europe, Japan, Singapore, and the Republic of Korea. Most rehabilitation measures have been related to improving water quality and river connectivity for fish or the improvement of riparian vegetation. The limited extent of most rehabilitation measures (i.e., not considering the entire catchment) often constrains the improvement of biological condition. Yet, many rehabilitation projects also lack pre-and/or post-monitoring of ecological condition, which prevents assessing the success and shortcomings of the recovery measures. Economic constraints are the most cited limitation for implementing monitoring programs and rehabilitation actions, followed by technical limitations, limited knowledge of the fauna and flora and their life-history traits (especially in Africa, South America and Mexico), and poor awareness by decision-makers. On the other hand, citizen involvement is recognized as key to the success and sustainability of rehabilitation projects. Thus, establishing rehabilitation needs, defining clear goals, tracking progress towards achieving them, and involving local populations and stakeholders are key recommendations for rehabilitation projects (Table 1). Large-extent and long-term monitoring programs are also essential to provide a realistic overview of the condition of rivers worldwide. Soon, the use of DNA biological samples and eDNA to investigate aquatic diversity could contribute to reducing costs and thus increase monitoring efforts and a more complete assessment of biodiversity. Finally, we propose developing transcontinental teams to elaborate and improve technical guidelines for implementing biological monitoring programs and river rehabilitation and establishing common financial and technical frameworks for managing international catchments. We also recommend providing such expert teams through the United Nations Environment Program to aid the extension of biomonitoring, bioassessment, and river rehabilitation knowledge globally.
    MeSH terms: Animals; Australia; Brazil; Chile; DNA; European Union; Gambia; Goals; Japan; Licensure; Malaysia; Mexico; New Zealand; Singapore; South Africa; Thailand; United Nations; Vietnam; Water; Ecosystem; Biodiversity; Rivers; Republic of Korea; Water Quality
  7. Sathian B, Asim M, Banerjee I, Roy B, Pizarro AB, Mancha MA, et al.
    Nepal J Epidemiol, 2021 Mar;11(1):959-982.
    PMID: 33868742 DOI: 10.3126/nje.v11i1.36163
    Background: To date, there is no comprehensive systematic review and meta-analysis to assess the suitability of COVID-19 vaccines for mass immunization. The current systematic review and meta-analysis was conducted to evaluate the safety and immunogenicity of novel COVID-19 vaccine candidates under clinical trial evaluation and present a contemporary update on the development and implementation of a potential vaccines.

    Methods: For this study PubMed, MEDLINE, and Embase electronic databases were used to search for eligible studies on the interface between novel coronavirus and vaccine design until December 31, 2020.

    Results: We have included fourteen non-randomized and randomized controlled phase I-III trials. Implementation of a universal vaccination program with proven safety and efficacy through robust clinical evaluation is the long-term goal for preventing COVID-19. The immunization program must be cost-effective for mass production and accessibility. Despite pioneering techniques for the fast-track development of the vaccine in the current global emergency, mass production and availability of an effective COVID-19 vaccine could take some more time.

    Conclusion: Our findings suggest a revisiting of the reported solicited and unsolicited systemic adverse events for COVID-19 candidate vaccines. Hence, it is alarming to judiciously expose thousands of participants to COVID-19 candidate vaccines at Phase-3 trials that have adverse events and insufficient evidence on safety and effectiveness that necessitates further justification.

    MeSH terms: Cost-Benefit Analysis; Electronics; Goals; Humans; Motivation; Vaccines; MEDLINE; Coronavirus; Mass Vaccination
  8. Ismail MA, Norhayati MN, Mohamad N
    PeerJ, 2021;9:e11173.
    PMID: 33868820 DOI: 10.7717/peerj.11173
    Background: This systematic review and meta-analysis aimed to determine the effectiveness of olive leaf extract on cardiometabolic profiles among prehypertensive and hypertensive groups.

    Methodology: The Cochrane central register of controlled trials, Medline (1966 to April week 1, 2020), Embase (1966 to April week 1, 2020) and trial registries for relevant randomized clinical trials were used. Published and unpublished randomized clinical trials were reviewed and evaluated. Random effects models were used to estimate the continuous outcomes and mean differences (MDs); both with 95% confidence intervals (CIs). The primary outcomes were changes in systolic and diastolic BP. The secondary outcomes were changes in lipid profile, glucose metabolism, inflammatory markers for CVD, kidney and liver functions safety parameters. We assessed the data for risk of bias, heterogeneity, sensitivity, reporting bias and quality of evidence.

    Results: Five trials were included involving 325 patients aged 18-80 years. Two trials involved high-income countries and three trials involved moderate-income countries. The analysis performed was based on three comparisons. No significant changes were found between systolic or diastolic blood pressure (BP) for the first comparison, 1,000 mg per day for a combined formulation of olive leaf extract versus a placebo. The second comparison, 500 mg per day of olive leaf extract versus placebo or no treatment, showed a significant reduction in systolic BP over a period of at least 8 weeks of follow up (MD -5.78 mmHg, 95% CI [-10.27 to -1.30]) and no significant changes on diastolic BP. The third comparison, 1,000 mg per day of olive leaf extract versus placebo shows no significant difference but an almost similar reduction in systolic BP (-11.5 mmHg in olive leaf extract and -13.7 mmHg in placebo, MD 2.2 mmHg, 95% CI [-0.43-4.83]) and diastolic BP (-4.8 mmHg in olive leaf extract and -6.4 mmHg in placebo, MD 1.60 mmHg, 95% CI [-0.13-3.33]). For secondary outcomes, 1,000 mg per day of olive leaf extract versus captopril showed a reduction in LDL (MD -6.00 mg/dl, 95% CI [-11.5 to -0.50]). The 500 mg per day olive leaf extract versus placebo showed a reduction in inflammatory markers for CVD IL-6 (MD -6.83 ng/L, 95% CI [-13.15 to -0.51]), IL-8 (MD -8.24 ng/L, 95% CI [-16.00 to -0.48) and TNF-alpha (MD -7.40 ng/L, 95% CI [-13.23 to -1.57]).

    Conclusions: The results from this review suggest the reduction of systolic BP, LDL and inflammatory biomarkers, but it may not provide a robust conclusion regarding the effects of olive leaf extract on cardiometabolic profile due to the limited number of participants in the included trials.

    Review registrations: PROSPERO CDR 42020181212.

    MeSH terms: Adolescent; Adult; Aged; Aged, 80 and over; Blood Pressure; Captopril; Follow-Up Studies; Glucose; Humans; Hypertension; Kidney; Lipids; Liver; Middle Aged; Plant Extracts; Registries; Systole; Tumor Necrosis Factor-alpha; Biomarkers; Interleukin-6; Confidence Intervals; Randomized Controlled Trials as Topic; Interleukin-8; Developed Countries; Olea; Young Adult
  9. Behrooz AB, Syahir A
    Front Oncol, 2021;11:642719.
    PMID: 33869033 DOI: 10.3389/fonc.2021.642719
    Glioblastoma multiforme (GBM) is one of the most lethal forms of primary brain tumors. Glioblastoma stem cells (GSCs) play an undeniable role in tumor development by activating multiple signaling pathways such as Wnt/β-catenin and PI3K/AKT/mTOR that facilitate brain tumor formation. CD133, a transmembrane glycoprotein, has been used to classify cancer stem cells (CSCs) in GBM. The therapeutic value of CD133 is a biomarker of the CSC in multiple cancers. It also leads to growth and recurrence of the tumor. More recent findings have confirmed the association of telomerase/TERT with Wnt/β-catenin and the PI3K/AKT/mTOR signaling pathways. Advance studies have shown that crosstalk between CD133, Wnt/β-catenin, and telomerase/TERT can facilitate GBM stemness and lead to therapeutic resistance. Mechanistic insight into signaling mechanisms downstream of surface biomarkers has been revolutionized by facilitating targeting of tumor-specific molecular deregulation. This review also addresses the importance of interplay between CD133, Wnt/β-catenin and TERT signaling pathways in GSCs and outlines the future therapeutic goals for glioblastoma treatment.
    MeSH terms: Brain Neoplasms; Glioblastoma; Glycoproteins; Goals; Neoplasm Recurrence, Local; Neoplastic Stem Cells; Signal Transduction; Biomarkers; Drug Resistance, Neoplasm; Telomerase; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; beta Catenin; TOR Serine-Threonine Kinases
  10. Zamram QAZM, Mohsin HF, Mohamad MM, Nor Hazalin NAM, Hamid KA
    Curr Drug Deliv, 2021 Apr 18.
    PMID: 33874872 DOI: 10.2174/1567201818666210419114809
    AIM: Formulating topical products for skin delivery has always been a challenge for pharmaceutical scientists to fulfil good formulation criteria. Despite the challenges, gel-based drug delivery offers some advantages such that it is non-invasive, painless, avoidance of the first-pass metabolism and has satisfactory patient compliance.

    OBJECTIVES: In this study, Chromolaena odorata gel and quercetin gel (bioactive flavonoid compound) were successfully formulated and compared with placebo and conventional wound aid gel. The chromatographic profilling was conducted to screen the presence of phytoconstituents. Subsequently, all formulated gels were subjected to physical characteristic and stability study.

    METHODS: Reverse Phase High-Performance Liquid Chromatography (RP-HPLC) of C.odorata methanolic leaves extract shows a distinct compound separation at retention time 8.4min to 34.8 min at 254nm. All gels were characterised by evaluating their rheological properties including storage modulus, loss modulus and plastic viscosity. Besides, texture analysis was performed to measure the gels' firmness, consistency, cohesiveness, and viscosity index.

    RESULTS: From the observation, C. odorata gel demonstrated better spreadability as compared to the other gels, which acquired less work and favourable to be applied onto the skin. Moreover, C. odorata gel showed no changes in organoleptic properties and proven to be stable after 30 days of accelerated stability study at 40°C ± 2°C with relative humidity (RH) of 75%± 5%.

    CONCLUSION: C. odorata gel has shown to be stable, reflecting the combination of materials used in the formulation, which did not degrade throughout the study. This work suggests the potential of this gel as a vehicle to deliver the active ingredients of C. odorata to the skin, which can be further explored as a topical application in antimicrobial wound management or other skin diseases study.

    MeSH terms: Methanol; Anti-Infective Agents; Chromatography, High Pressure Liquid; Excipients; Flavonoids; Gels; Humans; Humidity; Patient Compliance; Plant Extracts; Plastics; Quercetin; Sensation; Skin; Skin Diseases; Viscosity; Plant Leaves; Chromolaena
  11. Adnan M, Rasul A, Shah MA, Hussain G, Asrar M, Riaza A, et al.
    PMID: 33874875 DOI: 10.2174/1871520621666210419095829
    The identification and development of radioprotective agents has emerged as a subject matter of research during recent years due to the growing usage of ionizing radiation in different areas of human life. Previous work on synthetic radioprotectors has achieved limited progress because of the numerous issues associated with toxicity. Compounds extracted from plants have potential to serve as lead candidates for developing ideal radioprotectors due to their low cost, safety and selectivity. Polyphenols are the most abundant and commonly dispersed group of biologically active molecules possessing broad range of pharmacological activities. Polyphenols have displayed efficacy for radioprotection during various investigations and can be administered at high doses with lesser toxicity. Detoxification of free radicals, modulating inflammatory responses, DNA repair, stimulation of hematopoietic recovery, and immune functions are the main mechanisms for radiation protection with polyphenols. Epicatechin, epigallocatechin-3-gallate, apigenin, caffeic acid phenylethylester, and silibinin provide cytoprotection together with the suppression of many pro-inflammatory cytokines owing to their free radical scavenging, anti-oxidant, and anti-inflammatory properties. Curcumin, resveratrol, quercetin, gallic acid, and rutin's radioprotective properties are regulated primarily by direct or indirect decline in cellular stress. Thus, polyphenols may serve as potential candidates for radioprotection in the near future, however, extensive investigations are still required to better understand their protection mechanisms.
    MeSH terms: Anti-Inflammatory Agents; Antioxidants; Catechin; Curcumin; DNA Repair; Free Radicals; Gallic Acid; Humans; Quercetin; Radiation Protection; Radiation-Protective Agents; Radiation, Ionizing; Rutin; Cytokines; Oxidants; Hematopoietic Stem Cell Transplantation; Cytoprotection; Apigenin; Polyphenols
  12. Khamalrudin N, Goh BS
    BMJ Case Rep, 2021 Apr 19;14(4).
    PMID: 33875496 DOI: 10.1136/bcr-2020-235936
    Infantile haemangioma represents a congenital vascular anomaly commonly observed in the head and neck region. Such an occurrence over the postcricoid region, however, is rather unusual. Herein, the authors report a case of a synchronous postcricoid haemangioma in a 7-week-old newborn diagnosed with severe laryngomalacia. In addition to the floppy redundant arytenoid mucosa, flexible laryngoscopy revealed a lobulated bluish mass at the postcricoid. The lesion was hyperintense on T1-weighted sequence and was enhanced with contrast, supporting the diagnosis of a haemangioma. She underwent surgical excision of the haemangioma with intralesional steroid injection. Surveillance at 6-month postoperation did not show disease recurrence.
    MeSH terms: Female; Hemangioma; Humans; Infant, Newborn; Laryngoscopy; Mucous Membrane; Neck; Neoplasm Recurrence, Local; Steroids; Injections, Intralesional; Hemangioma, Capillary; Laryngomalacia
  13. Wong HK, Estudillo AJ, Stephen ID, Keeble DRT
    Sci Rep, 2021 Apr 19;11(1):8507.
    PMID: 33875735 DOI: 10.1038/s41598-021-87933-1
    It is widely accepted that holistic processing is important for face perception. However, it remains unclear whether the other-race effect (ORE) (i.e. superior recognition for own-race faces) arises from reduced holistic processing of other-race faces. To address this issue, we adopted a cross-cultural design where Malaysian Chinese, African, European Caucasian and Australian Caucasian participants performed four different tasks: (1) yes-no face recognition, (2) composite, (3) whole-part and (4) global-local tasks. Each face task was completed with unfamiliar own- and other-race faces. Results showed a pronounced ORE in the face recognition task. Both composite-face and whole-part effects were found; however, these holistic effects did not appear to be stronger for other-race faces than for own-race faces. In the global-local task, Malaysian Chinese and African participants demonstrated a stronger global processing bias compared to both European- and Australian-Caucasian participants. Importantly, we found little or no cross-task correlation between any of the holistic processing measures and face recognition ability. Overall, our findings cast doubt on the prevailing account that the ORE in face recognition is due to reduced holistic processing in other-race faces. Further studies should adopt an interactionist approach taking into account cultural, motivational, and socio-cognitive factors.
    MeSH terms: Facial Recognition; Australia; Cognition; Cross-Cultural Comparison; Humans; Motivation; Asian Continental Ancestry Group
  14. Poorthuis MHF, Morris DR, de Borst GJ, Bots ML, Greving JP, Visseren FLJ, et al.
    Br J Surg, 2021 Apr 19.
    PMID: 33876207 DOI: 10.1093/bjs/znab040
    BACKGROUND: Recommendations for screening patients with lower-extremity arterial disease (LEAD) to detect asymptomatic carotid stenosis (ACS) are conflicting. Prediction models might identify patients at high risk of ACS, possibly allowing targeted screening to improve preventive therapy and compliance.

    METHODS: A systematic search for prediction models for at least 50 per cent ACS in patients with LEAD was conducted. A prediction model in screened patients from the USA with an ankle : brachial pressure index of 0.9 or less was subsequently developed, and assessed for discrimination and calibration. External validation was performed in two independent cohorts, from the UK and the Netherlands.

    RESULTS: After screening 4907 studies, no previously published prediction models were found. For development of a new model, data for 112 117 patients were used, of whom 6354 (5.7 per cent) had at least 50 per cent ACS and 2801 (2.5 per cent) had at least 70 per cent ACS. Age, sex, smoking status, history of hypercholesterolaemia, stroke/transient ischaemic attack, coronary heart disease and measured systolic BP were predictors of ACS. The model discrimination had an area under the receiver operating characteristic (AUROC) curve of 0.71 (95 per cent c.i. 0.71 to 0.72) for at least 50 per cent ACS and 0.73 (0.72 to 0.73) for at least 70 per cent ACS. Screening the 20 per cent of patients at greatest risk detected 12.4 per cent with at least 50 per cent ACS (number needed to screen (NNS) 8] and 5.8 per cent with at least 70 per cent ACS (NNS 17). This yielded 44.2 and 46.9 per cent of patients with at least 50 and 70 per cent ACS respectively. External validation showed reliable discrimination and adequate calibration.

    CONCLUSION: The present risk score can predict significant ACS in patients with LEAD. This approach may inform targeted screening of high-risk individuals to enhance the detection of ACS.

    MeSH terms: Ankle; Calibration; Ischemic Attack, Transient; Coronary Disease; Humans; Hypercholesterolemia; Netherlands; Risk Factors; ROC Curve; Smoking; Carotid Stenosis; Area Under Curve; Stroke
  15. Chua LS, Segaran A, Wong HJ
    J Chromatogr Sci, 2021 Apr 20.
    PMID: 33876232 DOI: 10.1093/chromsci/bmab041
    The objective of the study was to fractionate the crude extract of Eurycoma longifolia (E. longifolia) roots and identify the intense peaks using HPLC-PDA-MS/MS, UPLC-MS/MS and H-NMR. Column chromatography was used to fractionate the crude extract into individual fractions using six solvent systems ranged from ethyl acetate, methanol and water in increasing polarity. Two fractions with nearly pure and intense peaks were selected for compound identification. Chromenone (coumarin) and chromone derivatives were putatively identified, besides several previously reported quassinoid glycosides (eurycomanone derived glycoside, 2,3-dehydro-4α-hydroxylongilactone glucoside, eurycomanol glycoside and eurycomanol trimer) in the fraction 11 of 100% methanol. A newly reported compound, namely hydroxyl glyyunanprosapogenin D (838 g/mol) was proposed to be the compound detected in the fraction 11 of 50% ethyl acetate and 50% methanol. This is also the first study to report the identification of chromenones and chromones in E. longifolia extract.
    MeSH terms: Methanol; Chromatography, High Pressure Liquid; Chromatography, Liquid; Chromones; Coumarins; Glucosides; Glycosides; Plant Extracts; Solvents; Water; Eurycoma; Quassins; Tandem Mass Spectrometry
  16. Li Y, Van Toan N, Wang Z, Samat KFB, Ono T
    Nanoscale Res Lett, 2021 Apr 20;16(1):64.
    PMID: 33877472 DOI: 10.1186/s11671-021-03524-z
    Porous silicon (Si) is a low thermal conductivity material, which has high potential for thermoelectric devices. However, low output performance of porous Si hinders the development of thermoelectric performance due to low electrical conductivity. The large contact resistance from nonlinear contact between porous Si and metal is one reason for the reduction of electrical conductivity. In this paper, p- and n-type porous Si were formed on Si substrate by metal-assisted chemical etching. To decrease contact resistance, p- and n-type spin on dopants are employed to dope an impurity element into p- and n-type porous Si surface, respectively. Compared to the Si substrate with undoped porous samples, ohmic contact can be obtained, and the electrical conductivity of doped p- and n-type porous Si can be improved to 1160 and 1390 S/m, respectively. Compared with the Si substrate, the special contact resistances for the doped p- and n-type porous Si layer decreases to 1.35 and 1.16 mΩ/cm2, respectively, by increasing the carrier concentration. However, the increase of the carrier concentration induces the decline of the Seebeck coefficient for p- and n-type Si substrates with doped porous Si samples to 491 and 480 μV/K, respectively. Power factor is related to the Seebeck coefficient and electrical conductivity of thermoelectric material, which is one vital factor that evaluates its output performance. Therefore, even though the Seebeck coefficient values of Si substrates with doped porous Si samples decrease, the doped porous Si layer can improve the power factor compared to undoped samples due to the enhancement of electrical conductivity, which facilitates its development for thermoelectric application.
    MeSH terms: Biochemical Phenomena; Electric Conductivity; Fibrinogen; Metals; Silicon; Thermal Conductivity; Porosity; Refractive Surgical Procedures
  17. Ayinla AY, Othman WAM, Rabiu M
    Acta Biotheor, 2021 Apr 20.
    PMID: 33877474 DOI: 10.1007/s10441-020-09406-8
    Tuberculosis has continued to retain its title as "the captain among these men of death". This is evident as it is the leading cause of death globally from a single infectious agent. TB as it is fondly called has become a major threat to the achievement of the sustainable development goals (SDG) and hence require inputs from different research disciplines. This work presents a mathematical model of tuberculosis. A compartmental model of seven classes was used in the model formulation comprising of the susceptible S, vaccinated V, exposed E, undiagnosed infectious I1, diagnosed infectious I2, treated T and recovered R. The stability analysis of the model was established as well as the condition for the model to undergo backward bifurcation. With the existence of backward bifurcation, keeping the basic reproduction number less than unity [Formula: see text] is no more sufficient to keep TB out of the community. Hence, it is shown by the analysis that vaccination program, diagnosis and treatment helps to control the TB dynamics. In furtherance to that, it is shown that preference should be given to diagnosis over treatment as diagnosis precedes treatment. It is as well shown that at lower vaccination rate (0-20%), TB would still be endemic in the population. As such, high vaccination rate is required to send TB out of the community.
    MeSH terms: Cause of Death; Communicable Diseases; Goals; Humans; Male; Models, Theoretical; Tuberculosis; Vaccination; Immunization Programs; Basic Reproduction Number
  18. Kong ZX, Karunakaran R, Abdul Jabar K, Ponnampalavanar S, Chong CW, Teh CSJ
    Microb Drug Resist, 2021 Apr 20.
    PMID: 33877888 DOI: 10.1089/mdr.2020.0096
    Background:
    Hypermucoviscous carbapenem-resistant Klebsiella pneumoniae (hmCRKp) is emerging globally and approaching the worst-case scenario in health care system.
    Aims:
    The main objective in this study was to determine the hypermucoviscous characteristics among the carbapenem-resistant K. pneumoniae (CRKp) isolated from a teaching hospital in Malaysia. The association of hypermucoviscous phenotype with the virulence traits and clinical presentations were also investigated.
    Methods:
    A retrospective study was conducted in University Malaya Medical Centre (UMMC). The presence of hypermucoviscous K. pneumoniae was identified among a collection of CRKp clinical isolates (first isolate per patient) from 2014 to 2015 using string test. Correlation between clinical and microbial characteristics of the hmCRKp was investigated.
    Results:
    A total of nine (7.5%) hmCRKp were detected among 120 CRKp isolates. Majority of the isolates were hospital acquired or health care-associated infections. None of the patients had typical pyogenic liver abscess. All of the hmCRKp isolates harbored carbapenemase genes and were multidrug resistant. K1/K serotype, peg-344, allS, and magA were not identified among hmCRKp isolates, whereas aerobactin siderophore receptor gene (iutA), iroB, rmpA, and rmpA2 were detected. Only three hmCRKp isolates were resistant to serum bactericidal.
    Conclusions:
    All the isolates presented inconclusive evidence for the interpretation of hypervirulence. Therefore, more study should be performed in the future to have a better understanding of the virulence mechanisms in correlation with the clinical and microbial determinants.
    MeSH terms: Bacterial Proteins; beta-Lactamases; Delivery of Health Care; Hospitals, Teaching; Humans; Hydroxamic Acids; Klebsiella pneumoniae; Malaysia; Retrospective Studies; Universities; Virulence; Carbapenems; Siderophores; Liver Abscess, Pyogenic; Serogroup
  19. Schönrath I, Tsvetkov VB, Barceló-Oliver M, Hebenbrock M, Zatsepin TS, Aralov AV, et al.
    J Inorg Biochem, 2021 Jan 27;219:111369.
    PMID: 33878529 DOI: 10.1016/j.jinorgbio.2021.111369
    The artificial nucleobase 7,8-dihydro-8-oxo-1,N6-ethenoadenine (X) was investigated with respect to its ability to engage in Ag(I)-mediated base pairing in DNA. Spectroscopic data indicate the formation of dinuclear X-Ag(I)2-X homo base pairs and mononuclear X-Ag(I)-C base pairs (C, cytosine). Density functional theory calculations and molecular dynamics simulations indicate that the nucleobase changes from its lactam tautomeric form prior to the formation of the Ag(I)-mediated base pair to the lactim form after the incorporation of the Ag(I) ions. Fluorescence spectroscopy indicates that the two Ag(I) ions of the homo base pair are incorporated sequentially. Isothermal titration calorimetry confirms that the affinity of one of the Ag(I) ions is about tenfold higher than that of the other Ag(I) ion. The computational analysis by means of density functional theory confirms a much larger reaction energy for the incorporation of the first Ag(I) ion. The thermal stabilization upon the formation of the dinuclear Ag(I)-mediated homo base pair exceeds the one previously observed for the closely related nucleobase 1,N6-ethenoadenine by far, despite very similar structures. This additional stabilization may stem from the presence of water molecules engaged in hydrogen bonding with the additional oxygen atom of the artificial nucleobase X. The highly stabilizing Ag(I)-mediated base pair is a valuable addition to established dinuclear metal-mediated base pairs.
    MeSH terms: Calorimetry; Cytosine; DNA; Hydrogen Bonding; Ions; Lactams; Oxygen; Silver; Spectrometry, Fluorescence; Water; Base Pairing; Physical Phenomena; Molecular Dynamics Simulation
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