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1.
Immunopharmacol Immunotoxicol ; 46(5): 685-694, 2024 Oct.
Article in English | MEDLINE | ID: mdl-39164801

ABSTRACT

OBJECTIVE: Inflammatory diseases are influenced by oxidative stress. Oxidatively damaged 8-oxoG in DNA is linked to inflammation. The enzyme OGG1 is responsible for repairing the damaged base in the DNA which is linked to pro-inflammatory signaling and severe inflammation. This study aims to explore the potential of targeting OGG1 as a therapeutic strategy in inflammatory disease conditions. METHODS: A comprehensive search and review of literature were conducted using appropriate scientific databases such as Google Scholar, Scopus, PubMed, Web of Science, and other references to obtain relevant information that suited the title and content of this article. RESULTS: Compelling pieces of evidence from many previous studies have shown the crucial role of the OGG1/8oxoG pathway in inflammatory disease conditions, leading to severe inflammatory response and death. Therefore, based on these pieces of evidence, targeting this enzyme (OGG1) using specific pharmacological inhibitors or interventions might lead to downregulation and amelioration of severe inflammation to reduce the morbimortality related to several disease conditions. CONCLUSION: This review highlighted the molecular mechanism of OGG1 activity via the 8-oxo/OGG1 pathway and its role in inflammation and inflammatory disease conditions. Due to the paucity of studies involving OGG1in inflammatory infectious diseases, further research projects are needed to explore the therapeutic potential of various OGG1 inhibitors to serve as novel therapeutic strategies in infectious inflammatory diseases of medical importance in developing countries such as malaria, meningitis, tuberculosis among others.


Subject(s)
DNA Glycosylases , Inflammation , Humans , DNA Glycosylases/antagonists & inhibitors , DNA Glycosylases/metabolism , Inflammation/drug therapy , Inflammation/immunology , Animals , Oxidative Stress/drug effects
2.
Adv Pharm Bull ; 14(1): 105-119, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38585461

ABSTRACT

Phytochemicals are compounds found in plants that possess a variety of bioactive properties, including antioxidant and immunomodulatory properties. Recent studies have highlighted the potential of phytochemicals in targeting specific signalling pathways involved in cytokine storm, a life-threatening clinical condition resulting from excessive immune cell activation and oversupply of proinflammatory cytokines. Several studies have documented the immunomodulatory effects of phytochemicals on immune function, including their ability to regulate essential cellular and molecular interactions of immune system cells. This makes them a promising alternative for cytokine storm management, especially when combined with existing chemotherapies. Furthermore, phytochemicals have been found to target multiple signalling pathways, including the TNF-α/NF-κB, IL-1/NF-κB, IFN-γ/JAK/STAT, and IL-6/JAK-STAT. These pathways play critical roles in the development and progression of cytokine storm, and targeting them with phytochemicals represents a promising strategy for controlling cytokine release and the subsequent inflammation. Studies have also investigated certain families of plant-related constituents and their potential immunomodulatory actions. In vivo and in vitro studies have reported the immunomodulatory effects of phytochemicals, which provide viable alternatives in the management of cytokine storm syndrome. The collective data from previous studies suggest that phytochemicals represent a potentially functional source of cytokine storm treatment and promote further exploration of these compounds as immunomodulatory agents for suppressing specific signalling cascade responses. Overall, the previous research findings support the use of phytochemicals as a complementary approach in managing cytokine storm and improving patient outcomes.

3.
Article in English | MEDLINE | ID: mdl-36361393

ABSTRACT

AIM: The COVID-19 pandemic has led to adaptation in teaching and learning methods. There is a possibility that this shift from the classroom to online learning will persist post-pandemic with implications to all involved. We explored the contribution of personal, academic stressors and environmental factors contributing to musculoskeletal pain among undergraduates due to online learning by integrating data from an online survey and one-to-one in-depth interviews. The association between musculoskeletal pain, personal, academic stressors and environmental factors among undergraduates due to online learning was also investigated. METHODS: Both quantitative and qualitative methods were used. A questionnaire was completed by 179 undergraduates (34 males and 145 females) aged between 18 to 25 years old. This was followed by an online, in-depth, one-to-one interview among 10 female undergraduates who reported severe musculoskeletal pain. The two sets of findings were integrated using a triangulation protocol. RESULT: The three most common musculoskeletal pains experienced by undergraduates due to online learning were low back (73.2%), followed by neck (68.7%) and shoulder (58.7%) pain. The six main themes identified from the interviews were: (1) Musculoskeletal pain characteristics; (2) academic issues; (3) difficulties faced by undergraduates due to teaching and learning; (4) emotions towards work/study; (5) work environment; and (6) time spent working at a workstation. Upper back pain was identified to be associated with personal (p < 0.05) and most environmental factors (p < 0.05). From the triangulation model, it was shown that personal, academic stressors and environmental factors were mainly from the workstation, uncomfortable environment, working posture and time spent at the workstation, which all contributed to musculoskeletal pain. CONCLUSIONS: This study showed that exercise, academic stressors, and environmental factors were associated with musculoskeletal pain among undergraduates due to online teaching and learning sessions. There may be a need to integrate an online prevention of musculoskeletal pain education package based on a biopsychosocial model with online teaching and learning for undergraduates.


Subject(s)
COVID-19 , Education, Distance , Musculoskeletal Pain , Male , Female , Humans , Adolescent , Young Adult , Adult , Musculoskeletal Pain/epidemiology , Musculoskeletal Pain/etiology , Pandemics , Students
4.
Malays J Med Sci ; 29(2): 8-17, 2022 Apr.
Article in English | MEDLINE | ID: mdl-35528818

ABSTRACT

In the vascular wall, defence against pathogenic damage requires a group of monocytes, the endothelium, dendritic cells, macrophages and a subsequent involvement of pattern recognition receptors anticipating damage-associated molecular patterns (DAMPs) to initiate an innate immune response. The endothelium plays a crucial role in regulating the duration, location and extent of the inflammatory cascade to ensure a definitive immune defence. Molecular changes in the expression of chemokines and cell adhesion molecules ensure protective responses against infection and injury. The multiprotein oligomer complex nucleotide-binding oligomerisation domain (NOD)-like receptor pyrin domain 3 (NLRP3) inflammasome plays a key role in the activation of inflammatory processes in response to DAMPs and pattern-associated molecular patterns. As a result of NLRP3 inflammasome activation, caspase-1 is activated and interleukin-1ß (IL-1ß) is produced. Caspase-1 is the main mediator of inflammatory feedback to tissue injury, and it is engaged both in the initiation of the inflammatory response and in the induction of cell death. NLRP3 inflammasome promotes further inflammatory responses and pyroptosis in the vascular endothelium; thus, its optimum regulation is crucial in cardiovascular homeostasis. This review outlines our current perception of the role of NLRP3 in vascular endothelial cells.

5.
Mediators Inflamm ; 2021: 6609143, 2021.
Article in English | MEDLINE | ID: mdl-34931116

ABSTRACT

The most prevalent cause of mortality and morbidity worldwide is acute coronary syndrome (ACS) and its consequences. Exposure to particulate matter (PM) from air pollution has been shown to impair both. Various plausible pathogenic mechanisms have been identified, including microRNAs (miRNAs), an epigenetic regulator for gene expression. Endogenous miRNAs, average 22-nucleotide RNAs (ribonucleic acid), regulate gene expression through mRNA cleavage or translation repression and can influence proinflammatory gene expression posttranscriptionally. However, little is known about miRNA responses to fine PM (PM2.5, PM10, ultrafine particles, black carbon, and polycyclic aromatic hydrocarbon) from air pollution and their potential contribution to cardiovascular consequences, including systemic inflammation regulation. For the past decades, microRNAs (miRNAs) have emerged as novel, prospective diagnostic and prognostic biomarkers in various illnesses, including ACS. We wanted to outline some of the most important studies in the field and address the possible utility of miRNAs in regulating particulate matter-induced ACS (PMIA) on inflammatory factors in this review.


Subject(s)
Acute Coronary Syndrome/chemically induced , Inflammation Mediators/metabolism , MicroRNAs/physiology , Particulate Matter/adverse effects , Humans
6.
Nurs Rep ; 11(4): 859-880, 2021 Oct 26.
Article in English | MEDLINE | ID: mdl-34968274

ABSTRACT

BACKGROUND: While the global maternal mortality ratio (MMR) shows a decreasing trend, there is room for improvement. Midwifery education has been under scrutiny to ensure that graduates acquire knowledge and skills relevant to the local context. OBJECTIVE: To review the basic professional midwifery qualification and pre-practice requirements in countries with lower MMR compared with Malaysia. METHODS: A rapid review of country-specific Ministry of Health and Midwifery Association websites and Advanced Google using standardised key words. English-language documents reporting the qualifications of midwives or other requirements to practise midwifery from countries with a lower MMR than Malaysia were included. RESULTS: Sixty-three documents from 35 countries were included. The minimum qualification required to become a midwife was a bachelor's degree. Most countries require registration or licensing to practise, and 35.5% have implemented preregistration national midwifery examinations. In addition, 13 countries require midwives to have nursing backgrounds. CONCLUSION: In countries achieving better maternal outcomes than Malaysia, midwifes often have a degree or higher qualification. As such, there is a need to reinvestigate and revise the midwifery qualification requirements in Malaysia.

7.
Front Cell Dev Biol ; 8: 564648, 2020.
Article in English | MEDLINE | ID: mdl-33324632

ABSTRACT

Colorectal cancer (CRC) is one of the most widely diagnosed cancers worldwide. It has been shown that the body-mass index (BMI) of the patients could influence the tumor microenvironment, treatment response, and overall survival rates. Nevertheless, the mechanism on how BMI affects the tumorigenesis process, particularly the tumor microenvironment is still elusive. Herein, we postulate that extracellular vesicles (EVs) from CRC patients and non-CRC volunteers with different BMI could affect immune cells differently, in CD8 T cells particularly. We isolated the EVs from the archived serum of CRC patients with high and low BMI, as well as healthy controls with similar BMI status. The EVs were further characterized via electron microscopy, western blot and dynamic light scattering. Then, functional analysis was performed on CD8 T cells including apoptosis, cell proliferation, gene expression profiling and cytokine release upon co-incubation with the different EVs. Our results suggest that CRC-derived EVs were able to regulate the CD8 T cells. In some assays, low BMI EVs were functionally different than high BMI EVs. This study highlights the possible difference in the regulatory mechanism of cancer patients-derived EVs, especially on CD8 T cells.

8.
Plant Dis ; 2020 Sep 23.
Article in English | MEDLINE | ID: mdl-32967557

ABSTRACT

Watermelon (Citrullus lanatus L.) is widely cultivated and consumed in Malaysia for its nutritional value. In June 2018, nearly 40% of the 'Red Rocky' watermelon plants in experimental plots of the research farm at Faculty of Agriculture, UPM Serdang, Selangor, Malaysia had leaf spot symptoms. Leaf spots were small, ranging 5 to 30 mm, yellow to brown, and circular to irregular in shape. With ages, the leafspots gradually enlarged and coalesced. To investigate the disease, ten symptomatic leaves were collected from the experimental plots. Diseased tissues (5 x 5 mm) were excied and surface sterilized with 0.5% sodium hypochlorite (NaOCl) for 2 min, rinsed twice with sterile distilled water, plated on potato dextrose agar (PDA), and incubated at 25 °C for 5 days. A total of ten isolates with similar colony morphologies were obtained from tissue samples. A single representative isolate "F" was further characterized by molecular analysis. All colonies were initially white in color, but later turned gray to black upon sporulation after 7 days. Conidia were produced in culture and were single-celled, black, smooth-walled, spherical in shape measuring 11.4 to 14 µm x 13.8 to 19 µm in diameter (n=40). These were borne on hyaline vesicles at the tip of a conidiophore. For molecular identification, genomic DNA was extracted from fresh mycelium of isolate F using DNeasy Plant Mini kit (Qiagen, Germantown, MD, USA). The internal transcribed spacer (ITS) region of rDNA and the translation elongation factor 1-alpha (TEF1-α) gene were amplified using the ITS5/ITS4 (White et al. 1990) and EF1-728F/EF1-986R primer sets (Carbone and Kohn 1999), respectively. BLASTn analysis of the ITS sequence revealed 100% identity (526 bp out of 526 bp) to Nigrospora sphaerica (GenBank Accession no. HQ608063). TEF1-α sequence had 100% identity (494 bp out 494 bp) with N. sphaerica (GenBank Accession no. MN995332). The resulting sequences were deposited in GenBank (ITS: Accession no. MK544066; TEF1-α Accession no. MT708197). Based on morphological and molecular characteristics, isolate "F" was identified as Nigrospora sphaerica (Sacc.) Mason (Chen et al. 2018). A pathogenicity test was conducted on five healthy leaves of five one-month-old watermelon 'Red Rocky' plants grown in a greenhouse. Leaves were wounded using a 34-mm-diameter florist pin frog and spray-inoculated until runoff with a conidial suspension (1 × 106 conidia/ml) of a 7-day-old culture. Five leaves from additional 2 plants were sprayed with sterile distilled water to serve as controls. Inoculated plants were covered with polyethylene bags for 48 h to maintain high humidity. Ten days post-inoculation, symptoms on inoculated leaves developed brown-to-black lesions similar to those observed in the field, while control leaves remained asymptomatic. N. sphaerica was re-isolated from all symptomatic tissues confirming Koch's postulates. N. sphaerica is distributed on a wide range of hosts and has been reported from 40 different host genera including monocotyledonous and dicotyledonous hosts (Wang et al. 2017). N. sphaerica has been reported to cause leaf spot of date palm in Pakistan (Alam et al. 2020) and kiwifruit in China (Chen et al. 2016). To our knowledge, this is the first report of N. sphaerica causing leaf spot of watermelon in Malaysia. This new disease could reduce fruit quality since sweetness and ripening are dependent on healthy foliage. Additionally, this disease can cause premature defoliation which would also reduce watermelon productivity.

9.
Int J Mol Sci ; 21(17)2020 Aug 26.
Article in English | MEDLINE | ID: mdl-32858859

ABSTRACT

Rhodococci are renowned for their great metabolic repertoire partly because of their numerous putative pathways for large number of specialized metabolites such as biosurfactant. Screening and genome-based assessment for the capacity to produce surface-active molecules was conducted on Rhodococcus sp. ADL36, a diesel-degrading Antarctic bacterium. The strain showed a positive bacterial adhesion to hydrocarbon (BATH) assay, drop collapse test, oil displacement activity, microplate assay, maximal emulsification index at 45% and ability to reduce water surface tension to < 30 mN/m. The evaluation of the cell-free supernatant demonstrated its high stability across the temperature, pH and salinity gradient although no correlation was found between the surface and emulsification activity. Based on the positive relationship between the assessment of macromolecules content and infrared analysis, the extracted biosurfactant synthesized was classified as a lipopeptide. Prediction of the secondary metabolites in the non-ribosomal peptide synthetase (NRPS) clusters suggested the likelihood of the surface-active lipopeptide production in the strain's genomic data. This is the third report of surface-active lipopeptide producers from this phylotype and the first from the polar region. The lipopeptide synthesized by ADL36 has the prospect to be an Antarctic remediation tool while furnishing a distinctive natural product for biotechnological application and research.


Subject(s)
Hydrocarbons/metabolism , Lipopeptides/metabolism , Rhodococcus/growth & development , Antarctic Regions , Bacterial Adhesion , Biodegradation, Environmental , Hydrogen-Ion Concentration , Rhodococcus/metabolism , Secondary Metabolism , Soil Microbiology , Temperature
10.
Front Oncol ; 9: 1113, 2019.
Article in English | MEDLINE | ID: mdl-31803605

ABSTRACT

Chemotherapy is the standard go-to treatment for cancer besides surgery and radiation. It has recently come to light that the interaction between chemotherapy and the immune system is important in maintaining tumor immunity as well as influencing the efficacy of the therapy. However, ample preclinical studies have shown that in addition to direct cytotoxic effects on cancer cells, a fraction of chemotherapeutic agents may promote immunogenic cell death, and alter the inflammatory milieu of the tumor microenvironment. Extracellular vesicles (EV) have been shown to interact with the tumor microenvironment by delivering alterative signals to the surrounding cells; as a result, this results in interference with each cell's capability to eradicate tumors or gives advantages to cancer cells so as to survive therapy. Chemotherapy-induced extracellular vesicles (chemo-EVs) have been theorized to be carrying different cargo loads than non-chemotherapy-induced EVs. Aside from chemoresistance, there is growing evidence to suggest that chemo-EVs could dictate tumor behavior, especially in terms of metastasis, immune response, and cancer stemness. This mini-review attempts to summarize and evaluate recent developments on the role of chemo-EVs in other aspects of tumor-related processes.

11.
BMC Public Health ; 19(1): 1454, 2019 Nov 05.
Article in English | MEDLINE | ID: mdl-31690296

ABSTRACT

BACKGROUND: Cervical cancer is the third most common cancer affecting women around the world in which the Human Papillomavirus (HPV) is the one of the recognized causative agent affecting women health. In response to this health issue, the Malaysian government had officially implemented the HPV immunisation programme for secondary schoolchildren in 2010 at the age of 13 years old and above. The purpose of this study is to investigate the sociodemographic determinants of knowledge and attitude among students of Universiti Tunku Abdul Rahman (UTAR) towards the HPV vaccination programme. METHODS: A cross-sectional study was conducted using self-administered questionnaires, recruiting 374 UTAR's students as the respondents by using convenience sampling method. Respondents were categorized as having good/poor level of knowledge and positive/negative attitude towards HPV vaccination. RESULTS: Over half of the respondents were females (64.5%) and the majority were aged 20 years old and below (55.8%). Generally, 54.7% of the total respondents had a high level of knowledge towards HPV vaccine while 57.5% of the total respondents showed a negative attitude towards HPV vaccine. Female respondents aged 20 years old and below showed good knowledge (56.4%) and a more positive attitude (55.8%) towards HPV vaccine. Students from the Faculty of Medicine and Health Sciences (FMHS) exhibited higher knowledge (67.3%) and positive attitude (62.4%) as compared to the Faculty of Accountancy and Management (FAM) which showed only 32.7% of knowledge and 37.6% of positive attitude towards the HPV vaccination. CONCLUSION: The majority of UTAR students possess good knowledge regarding HPV vaccination. Nonetheless, they demonstrated a negative attitude towards HPV vaccination, depicting the necessity to impart and further intensify the sense of health awareness among all students, especially among male students. The judicious use of social media apart from the conventional mass media should be an advantage as to enhance the practice of HPV vaccination among them and thereafter minimize the health and economic burdens of cervical cancer.


Subject(s)
Health Knowledge, Attitudes, Practice , Papillomavirus Vaccines , Students/psychology , Uterine Cervical Neoplasms/prevention & control , Adolescent , Adult , Cross-Sectional Studies , Female , Humans , Immunization Programs , Malaysia , Male , Papillomavirus Infections/prevention & control , Papillomavirus Vaccines/administration & dosage , Primary Prevention , Socioeconomic Factors , Students/statistics & numerical data , Surveys and Questionnaires , Universities , Young Adult
12.
J Biol Methods ; 4(2): e71, 2017.
Article in English | MEDLINE | ID: mdl-31453229

ABSTRACT

Endotoxin has been one of the topical chemical contaminants of major concern to researchers, especially in the field of bioprocessing. This major concern of researchers stems from the fact that the presence of Gram-negative bacterial endotoxin in intracellular products is unavoidable and requires complex downstream purification steps. For instance, endotoxin interacts with recombinant proteins, peptides, antibodies and aptamers and these interactions have formed the foundation for most biosensors for endotoxin detection. It has become imperative for researchers to engineer reliable means/techniques to detect, separate and remove endotoxin, without compromising the quality and quantity of the end-product. However, the underlying mechanism involved during endotoxin-biomolecule interaction is still a gray area. The use of quantitative molecular microscopy that provides high resolution of biomolecules is highly promising, hence, may lead to the development of improved endotoxin detection strategies in biomolecule preparation. Förster resonance energy transfer (FRET) spectroscopy is one of the emerging most powerful tools compatible with most super-resolution techniques for the analysis of molecular interactions. However, the scope of FRET has not been well-exploited in the analysis of endotoxin-biomolecule interaction. This article reviews endotoxin, its pathophysiological consequences and the interaction with biomolecules. Herein, we outline the common potential ways of using FRET to extend the current understanding of endotoxin-biomolecule interaction with the inference that a detailed understanding of the interaction is a prerequisite for the design of strategies for endotoxin identification and removal from protein milieus.

13.
Int J Mol Sci ; 15(8): 14728-42, 2014 Aug 22.
Article in English | MEDLINE | ID: mdl-25153628

ABSTRACT

In this work, biodegradable composites from poly(lactic acid) (PLA) and oil palm empty fruit bunch (OPEFB) fiber were prepared by melt blending method. Prior to mixing, the fiber was modified through bleaching treatment using hydrogen peroxide. Bleached fiber composite showed an improvement in mechanical properties as compared to untreated fiber composite due to the enhanced fiber/matrix interfacial adhesion. Interestingly, fiber bleaching treatment also improved the physical appearance of the composite. The study was extended by blending the composites with commercially available masterbatch colorant.


Subject(s)
Hydrogen Peroxide/chemistry , Lactic Acid/chemistry , Plant Oils/chemistry , Polymers/chemistry , Biocompatible Materials/chemistry , Microscopy, Electron, Scanning , Palm Oil , Polyesters , Spectroscopy, Fourier Transform Infrared , Thermogravimetry , X-Ray Diffraction
14.
Foodborne Pathog Dis ; 11(7): 529-36, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24749488

ABSTRACT

Shiga toxin-producing Escherichia coli (STEC) are a major family of foodborne pathogens of public health, zoonotic, and economic significance in the United States and worldwide. To date, there are no published reports on use of recombinase polymerase amplification (RPA) for STEC detection. The primary goal of this study was to assess the potential application of RPA in detection of STEC. This study focused on designing and evaluating RPA primers and fluorescent probes for isothermal (39°C) detection of STEC. Compatible sets of candidate primers and probes were designed for detection of Shiga toxin 1 and 2 (Stx1 and 2), respectively. The sets were evaluated for specificity and sensitivity against STEC (n=12) of various stx genotypes (stx1/stx2, stx1, or stx2, respectively), including non-Stx-producing E. coli (n=28) and other genera (n=7). The primers and probes that were designed targeted amplification of the subunit A moiety of stx1 and stx2. The assay detected STEC in real time (within 5-10 min at 39°C) with high sensitivity (93.5% vs. 90%; stx1 vs. stx2), specificity (99.1% vs. 100%; stx1 vs. stx2), and predictive value (97.9% for both stx1 vs. stx2). Limits of detection of ∼ 5-50 colony-forming units/mL were achieved in serially diluted cultures grown in brain heart infusion broth. This study successfully demonstrated for the first time that RPA can be used for isothermal real-time detection of STEC.


Subject(s)
Real-Time Polymerase Chain Reaction/methods , Shiga-Toxigenic Escherichia coli/isolation & purification , Colony Count, Microbial , Culture Media , DNA Primers , DNA, Bacterial/genetics , Food Contamination/analysis , Food Microbiology , Limit of Detection , Recombinases , Sensitivity and Specificity , Shiga Toxin 1/genetics , Shiga Toxin 2/genetics , Shiga-Toxigenic Escherichia coli/genetics
15.
Molecules ; 19(3): 2957-68, 2014 Mar 07.
Article in English | MEDLINE | ID: mdl-24609017

ABSTRACT

Bleaching treatment of kenaf fiber was performed in alkaline medium containing hydrogen peroxide solution maintained at pH 11 and 80 °C for 60 min. The bleached kenaf fiber was analyzed using Fourier Transform Infrared (FTIR) and X-ray Diffraction (XRD) analysis. The bleached kenaf fiber was then compounded with poly-(lactic acid) (PLA) via a melt blending method. The mechanical (tensile, flexural and impact) performance of the product was tested. The fiber treatment improved the mechanical properties of PLA/bleached kenaf fiber composites. Scanning electron micrograph (SEM) morphological analysis showed improvement of the interfacial adhesion between the fiber surface and polymer matrix.


Subject(s)
Biocompatible Materials/chemistry , Hibiscus/chemistry , Hydrogen Peroxide/chemistry , Lactic Acid/chemistry , Mechanical Phenomena , Polymers/chemistry , Polyesters , Spectroscopy, Fourier Transform Infrared , Surface Properties , X-Ray Diffraction
16.
J Environ Public Health ; 2012: 758349, 2012.
Article in English | MEDLINE | ID: mdl-22536276

ABSTRACT

Heavy metals, particularly cadmium, lead, and arsenic, constitute a significant potential threat to human health. This study was conducted to determine the levels of cadmium, lead, and arsenic in nail samples from farmers at Muda Agricultural Development Authority (MADA), Kedah, Malaysia, and evaluate factors that can contribute to their accumulations. A total of 116 farmers participated in this study. Inductively coupled plasma mass spectrometry (ICP-MS) was used to analyze concentration of heavy metals in the nail samples and questionnaires were given to participants to get demographic, health status, and their agricultural activities data. In this paper, the level of heavy metals was within the normal range and varies according to demographic factors. We found that there were significant correlations between working period with level of lead and arsenic (r=0.315 and r=0.242, resp., P<0.01) and age with lead level (r=0.175, P<0.05). Our findings suggested that agricultural activities could contribute to the accumulation of heavy metals in farmers. Hence, the control of environmental levels of and human exposure to these metals to prevent adverse health effects is still an important public health issue.


Subject(s)
Arsenic/metabolism , Cadmium/metabolism , Environmental Exposure , Environmental Pollutants/metabolism , Lead/metabolism , Nails/metabolism , Adult , Age Factors , Agriculture , Environmental Monitoring , Humans , Malaysia , Male , Mass Spectrometry , Statistics, Nonparametric , Surveys and Questionnaires
17.
Biochemistry ; 51(13): 2785-94, 2012 Apr 03.
Article in English | MEDLINE | ID: mdl-22369627

ABSTRACT

Halorhodopsin is a retinal protein with a seven-transmembrane helix and acts as an inward light-driven Cl(-) pump. In this study, structural state of the solubilized halorhodopsin (NpHR) from the biomembrane of mutant strain KM-1 of Natronomonas pharaonis in nonionic detergent was investigated. A gel filtration chromatography monitored absorbances at 280 and 504 nm corresponding to the protein and a lipid soluble pigment of bacterioruberin (BR), respectively, has clearly detected an oligomer formation of the NpHRs and a complex formation between the NpHR and BR in the solubilized system. A molar ratio of NpHR:BR in the solubilized complex was close to 1:1. Further SDS-PAGE analysis of the solubilized NpHR cross-linked by 1% glutaraldehyde has revealed that the NpHR forms homotrimer in detergent system. Although this trimeric structure was stable in the presence of NaCl, it was dissociated to the monomer by the heat treatment at 45 °C in the desalted condition. The same tendency has been reported in the case of trimeric NpHR expressed heterologously on the E. coli membrane, leading to a conclusion that the change of strength of the trimeric association dependent on the ion binding is a universal feature of the NpHR. Interestingly, the trimer dissociation on the NpHR was accompanied by the complete dissociation of the BR molecule from the protein, indicated that the cavity formed by the NpHR protomers in the trimeric conformation is important for tight binding of the BR. Because the binding affinity for Cl(-) and the resistance to hydroxylamine under light illumination showed only minor differences between the NpHR in the solubilized state and that on the biomembrane, the influences of solubilization to the tertiary structure and function of the protein are thought to be minor. This NpHR-BR complex in the solubilized system has a potential to be a good model system to investigate the intermolecular interaction between the membrane protein and lipid.


Subject(s)
Carotenoids/chemistry , Euryarchaeota/chemistry , Halorhodopsins/chemistry , Chromatography, Gel , Electrophoresis, Polyacrylamide Gel , Solubility
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