Displaying publications 61 - 80 of 106 in total

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  1. Shamsiah A. Rahman, Mohd Suhaimi Hamzah, Abdul Khalik Wood, Md Suhaimi Elias, Nazaratul Ashifa Abdullah Salim, Ezwiza Sanuri
    MyJurnal
    Chemical composition of fine (PM2.5) aerosol samples collected for the 5 years period (2001- 2005) using Gent Stacked filter unit sampler at Klang Valley (3 o 10 ’ 30 ’’ N, 101 o 43 ’ 24 ’’ E) were analysed using Neutron Activation Analysis (NAA) and Proton Induced X-ray Emission (PIXE). Results of the study show that the major component of the fine aerosol was black carbon and sulfur with the mass concentration ranged from 4.4 - 6.7µg m -3 and 1.2 - 1.9µg m -3 , respectively. The total fine aerosol mass concentration were in the ranged of 25 - 31µg m -3 with the reconstructed mass was about 50% as relative to the gravimetric mass. Statistical method, factor analysis with varimax approach has been applied to the aerosol composition data for the fingerprint identification. The analysis produces five identified fingerprint represent soil, industry, motor vehicles/biomass burning and Pb and Zn sources. There is also an unidentified source that could be related to unknown industrial activities.
    Matched MeSH terms: Aerosols
  2. Yap HH, Lee YW, Zairi J, Jahangir K, Adanan CR
    J Am Mosq Control Assoc, 2001 Mar;17(1):28-32.
    PMID: 11345415
    Indoor bioefficacy of the thermal fogging application of Pesguard FG 161, a formulation containing both knockdown and killing agents (active ingredient [AI]: d-tetramethrin 4% [w/w] and cyphenothrin 12% [w/w]) was compared with Resigen5 (AI: s-bioallethrin 0.8% [w/w], permethrin 125/75] 18.7% [w/w], and piperonyl butoxide 16.8% [w/w]), another pyrethroid formulation, as larvicides and adulticides against Aedes aegypti, Aedes albopictus, Anopheles sinensis, and Culex quinquefasciatus using a portable Agrofog AF35 sprayer indoors in houses on Penang Island, Malaysia. Pesguard FG 161 at the concentrations tested was effective against all 4 mosquito species tested. The water-based Pesguard FG 161 performed far better as a larvicide than the diesel-based formulation. Resigen was also effective as a larvicide and adulticide against all 4 mosquito species tested. Larvae of Ae. aegypti were most susceptible to water-based Pesguard FG 161, followed by Cx. quinquefasciatus, An. sinensis, and Ae. albopictus. Even at the lowest concentrations tested, Pesguard FG 161 showed adequate adulticidal properties. At higher dosages, water-based Pesguard FG 161 proved effective as a larvicide against all 4 mosquito species.
    Matched MeSH terms: Aerosols
  3. Yi X, Yin S, Huang L, Li H, Wang Y, Wang Q, et al.
    Sci Total Environ, 2021 Jun 01;771:144644.
    PMID: 33736175 DOI: 10.1016/j.scitotenv.2020.144644
    Chlorine radical plays an important role in the formation of ozone and secondary aerosols in the troposphere. It is hence important to develop comprehensive emissions inventory of chlorine precursors in order to enhance our understanding of the role of chlorine chemistry in ozone and secondary pollution issues. Based on a bottom-up methodology, this study presents a comprehensive emission inventory for major atomic chlorine precursors in the Yangtze River Delta (YRD) region of China for the year 2017. Four primary chlorine precursors are considered in this study: hydrogen chloride (HCl), fine particulate chloride (Cl-) (Cl- in PM2.5), chlorine gas (Cl2), and hypochlorous acid (HClO) with emissions estimated for twelve source categories. The total emissions of these four species in the YRD region are estimated to be 20,424 t, 15,719 t, 1556 and 9331 t, respectively. The emissions of HCl are substantial, with major emissions from biomass burning and coal combustion, together accounting for 68% of the total HCl emissions. Fine particulate Cl- is mainly emitted from industrial processing, biomass burning and waste incineration. The emissions of Cl2 and HClO are mainly associated with usage of chlorine-containing disinfectants, for example, water treatment, wastewater treatment, and swimming pools. Emissions of each chlorine precursor are spatially allocated based on the characteristics of individual source category. This study provides important basic dataset for further studies with respect to the effects of chlorine chemistry on the formation of air pollution complex in the YRD region.
    Matched MeSH terms: Aerosols
  4. Storey M, Roberts RG, Saidin M
    Proc Natl Acad Sci U S A, 2012 Nov 13;109(46):18684-8.
    PMID: 23112159 DOI: 10.1073/pnas.1208178109
    The Toba supereruption in Sumatra, ∼74 thousand years (ka) ago, was the largest terrestrial volcanic event of the Quaternary. Ash and sulfate aerosols were deposited in both hemispheres, forming a time-marker horizon that can be used to synchronize late Quaternary records globally. A precise numerical age for this event has proved elusive, with dating uncertainties larger than the millennial-scale climate cycles that characterized this period. We report an astronomically calibrated (40)Ar/(39)Ar age of 73.88 ± 0.32 ka (1σ, full external errors) for sanidine crystals extracted from Toba deposits in the Lenggong Valley, Malaysia, 350 km from the eruption source and 6 km from an archaeological site with stone artifacts buried by ash. If these artifacts were made by Homo sapiens, as has been suggested, then our age indicates that modern humans had reached Southeast Asia by ∼74 ka ago. Our (40)Ar/(39)Ar age is an order-of-magnitude more precise than previous estimates, resolving the timing of the eruption to the middle of the cold interval between Dansgaard-Oeschger events 20 and 19, when a peak in sulfate concentration occurred as registered by Greenland ice cores. This peak is followed by a ∼10 °C drop in the Greenland surface temperature over ∼150 y, revealing the possible climatic impact of the eruption. Our (40)Ar/(39)Ar age also provides a high-precision calibration point for other ice, marine, and terrestrial archives containing Toba sulfates and ash, facilitating their global synchronization at unprecedented resolution for a critical period in Earth and human history beyond the range of (14)C dating.
    Matched MeSH terms: Aerosols
  5. Mansoor MA, Ismail A, Yahya R, Arifin Z, Tiekink ER, Weng NS, et al.
    Inorg Chem, 2013 May 20;52(10):5624-6.
    PMID: 23627942 DOI: 10.1021/ic302772b
    Perovskite-structured lead titanate thin films have been grown on FTO-coated glass substrates from a single-source heterometallic molecular complex, [PbTi(μ2-O2CCF3)4(THF)3(μ3-O)]2 (1), which was isolated in quantitative yield from the reaction of tetraacetatolead(IV), tetrabutoxytitanium(IV), and trifluoroacetic acid from a tetrahydrofuran solution. Complex 1 has been characterized by physicochemical methods such as melting point, microanalysis, FTIR, (1)H and (19)F NMR, thermal analysis, and single-crystal X-ray diffraction (XRD) analysis. Thin films of lead titanate having spherical particles of various sizes have been grown from 1 by aerosol-assisted chemical vapor deposition at 550 °C. The thin films have been characterized by powder XRD, scanning electron microscopy, and energy-dispersive X-ray analysis. An optical band gap of 3.69 eV has been estimated by UV-visible spectrophotometry.
    Matched MeSH terms: Aerosols
  6. Omar NY, Mon TC, Rahman NA, Abas MR
    Sci Total Environ, 2006 Oct 1;369(1-3):76-81.
    PMID: 16766020
    The concentrations and distributions of particle bound polycyclic aromatic hydrocarbons (PAHs) collected over a 10 month period in ambient environment, at street levels as well as during a hazy episode are reported. Ambient and street level distributions of PAHs were similar and their occurrence was attributed to vehicular emissions. However, in haze particles, a different pattern of PAHs was observed, characterized by relatively low levels of benzo[a]pyrene (BaP) and high levels of benzofluoranthenes (BFs). The BaP equivalency results showed that the potential health risk associated with haze smoke particles was 4 times higher than that of street level particles whereas the lowest health risk was associated with ambient atmospheric particles.
    Matched MeSH terms: Aerosols
  7. Khan MF, Latif MT, Amil N, Juneng L, Mohamad N, Nadzir MS, et al.
    Environ Sci Pollut Res Int, 2015 Sep;22(17):13111-26.
    PMID: 25925145 DOI: 10.1007/s11356-015-4541-4
    Principal component analysis (PCA) and correlation have been used to study the variability of particle mass and particle number concentrations (PNC) in a tropical semi-urban environment. PNC and mass concentration (diameter in the range of 0.25->32.0 μm) have been measured from 1 February to 26 February 2013 using an in situ Grimm aerosol sampler. We found that the 24-h average total suspended particulates (TSP), particulate matter ≤10 μm (PM10), particulate matter ≤2.5 μm (PM2.5) and particulate matter ≤1 μm (PM1) were 14.37 ± 4.43, 14.11 ± 4.39, 12.53 ± 4.13 and 10.53 ± 3.98 μg m(-3), respectively. PNC in the accumulation mode (<500 nm) was the most abundant (at about 99 %). Five principal components (PCs) resulted from the PCA analysis where PC1 (43.8 % variance) predominates with PNC in the fine and sub-microme tre range. PC2, PC3, PC4 and PC5 explain 16.5, 12.4, 6.0 and 5.6 % of the variance to address the coarse, coarser, accumulation and giant fraction of PNC, respectively. Our particle distribution results show good agreement with the moderate resolution imaging spectroradiometer (MODIS) distribution.
    Matched MeSH terms: Aerosols
  8. Jaafar SA, Latif MT, Razak IS, Shaharudin MZ, Khan MF, Wahid NBA, et al.
    Mar Pollut Bull, 2016 Aug 15;109(1):480-489.
    PMID: 27230987 DOI: 10.1016/j.marpolbul.2016.05.017
    This study determined the effect of monsoonal changes on the composition of atmospheric surfactants in coastal areas. The composition of anions (SO4(2-), NO3(-), Cl(-), F(-)) and the major elements (Ca, K, Mg, Na) in aerosols were used to determine the possible sources of surfactants. Surfactant compositions were determined using a colorimetric method as methylene blue active substances (MBAS) and disulphine blue active substances (DBAS). The anion and major element compositions of the aerosol samples were determined by ion chromatography (IC) and inductively coupled plasma mass spectrometry (ICP-MS), respectively. The results indicated that the concentrations of surfactant in aerosols were dominated by MBAS (34-326pmolm(-3)). Monsoonal changes were found to significantly affect the concentration of surfactants. Using principal component analysis-multiple linear regressions (PCA-MLR), major possible sources for surfactants in the aerosols were motor vehicle emissions, secondary aerosol and the combustion of biomass along with marine aerosol.
    Matched MeSH terms: Aerosols
  9. Mori M, Sagara K, Arai K, Nakatani N, Ohira S, Toda K, et al.
    J Chromatogr A, 2016 Jan 29;1431:131-7.
    PMID: 26755416 DOI: 10.1016/j.chroma.2015.12.064
    Selective separation and sensitive detection of dissolved silicon and boron (DSi and DB) in aqueous solution was achieved by combining an electrodialytic ion isolation device (EID) as a salt remover, an ion-exclusion chromatography (IEC) column, and a corona charged aerosol detector (CCAD) in sequence. DSi and DB were separated by IEC on the H(+)-form of a cation exchange resin column using pure water eluent. DSi and DB were detected after IEC separation by the CCAD with much greater sensitivity than by conductimetric detection. The five-channel EID, which consisted of anion and cation acceptors, cathode and anode isolators, and a sample channel, removed salt from the sample prior to the IEC-CCAD. DSi and DB were scarcely attracted to the anion accepter in the EID and passed almost quantitatively through the sample channel. Thus, the coupled EID-IEC-CCAD device can isolate DSi and DB from artificial seawater and hot spring water by efficiently removing high concentrations of Cl(-) and SO4(2-) (e.g., 98% and 80% at 0.10molL(-1) each, respectively). The detection limits at a signal-to-noise ratio of 3 were 0.52μmolL(-1) for DSi and 7.1μmolL(-1) for DB. The relative standard deviations (RSD, n=5) of peak areas were 0.12% for DSi and 4.3% for DB.
    Matched MeSH terms: Aerosols
  10. Foo CY, Lim HN, Pandikumar A, Huang NM, Ng YH
    J Hazard Mater, 2016 Mar 5;304:400-8.
    PMID: 26595899 DOI: 10.1016/j.jhazmat.2015.11.004
    A newly developed CdS/rGO/CC electrode was prepared based on a flexible carbon cloth (CC) substrate with cadmium sulfide (CdS) nanoparticles and reduced graphene oxide (rGO). The CdS was synthesized using an aerosol-assisted chemical vapor deposition (AACVD) method, and the graphene oxide was thermally reduced on the modified electrode surface. The existence of rGO in the CdS-modified electrode increased the photocurrent intensity of the CdS/rGO/CC-modified electrode by three orders of magnitude, compared to that of the CdS/ITO electrode and two orders of magnitude higher than the CdS/CC electrode. A new visible-light-prompt photoelectrochemical sensor was developed based on the competitive binding reaction of Cu(2+) and CdS on the electrode surface. The results showed that the effect of the Cu(2+) on the photocurrent response was concentration-dependent over the linear ranges of 0.1-1.0 μM and 1.0-40.0 μM with a detection limit of 0.05 μM. The results of a selectivity test showed that this modified electrode has a high response toward Cu(2+) compared to other heavy metal ions. The proposed CdS/rGO/CC electrode provided a significantly high potential current compared to other reported values, and could be a practical tool for the fast, sensitive, and selective determination of Cu(2+).
    Matched MeSH terms: Aerosols
  11. Gong QQ, Tay JYS, Veronica N, Xu J, Heng PWS, Zhang YP, et al.
    Pharm Dev Technol, 2023 Feb;28(2):164-175.
    PMID: 36683577 DOI: 10.1080/10837450.2023.2171434
    Surface roughness of carrier particles can impact dry powder inhaler (DPI) performance. There are opposing views on the effect of roughness on DPI performance. Hence, a systematic approach is needed to modify carrier surfaces and evaluate the impact on drug delivery. Carrier particle surfaces were modified by fluid bed coating with saturated lactose containing micronized lactose of different sizes (2, 5 and 8 μm) and coated to different levels (20, 40, 60 and 80%). Their drug delivery performance was assessed by the fine particle fraction (FPF). Roughness parameters, mean arithmetic roughness (Ra) and arithmetic mean height (Sa), of the carrier particles, were also evaluated using optical profilometry and scanning laser microscopy. Generally, particles of higher Ra had higher FPF. Higher Sa resulted in higher FPF only for particles with 60 and 80% coat levels. Reduced contact surface area between the drug particle and rougher carrier particle resulted in easier drug detachment during aerosolization. The 5 µm micronized lactose produced optimal carrier particles with respect to FPF and surface roughness. The study highlighted that with the ideal particles for surface roughening and coating level, surface roughening could be efficiently achieved by fluid bed coating for superior DPI performance.
    Matched MeSH terms: Aerosols
  12. Ganapathy V, Jaganathan R, Chinnaiyan M, Chengizkhan G, Sadhasivam B, Manyanga J, et al.
    Food Chem Toxicol, 2025 Feb;196:115216.
    PMID: 39736445 DOI: 10.1016/j.fct.2024.115216
    Electronic cigarettes (e-cigarettes) have emerged as a potential alternative to traditional smoking and may aid in tobacco harm reduction and smoking cessation. E-cigarette use has notably increased, especially among young non-tobacco users, raising concerns due to the unknown long-term health effects. The oral cavity is the first and one of the most crucial anatomical sites for the deposition of e-cigarette aerosols. E-cigarette aerosols contain nicotine, flavors, volatile organic compounds, heavy metals, carcinogens, and other hazardous substances. These aerosols impact the oral cavity, disrupting host-microbial interactions and triggering gingivitis and systemic diseases. Furthermore, oral inflammation and periodontitis can be caused by proinflammatory cytokines induced by e-cigarette aerosols. The toxic components of e-cigarette aerosols increase the cellular reactive oxygen species (ROS) levels, reduce antioxidant capacity, increase DNA damage, and disrupt repair processes, which may further contribute to harmful effects on oral epithelum, leading to inflammatory and pre-malignant oral epithelial lesions. In this review, we analyze the toxicological properties of compounds in e-cigarette aerosols, exploring their cytotoxic, genotoxic, and inflammatory effects on oral health and delving into the underlying molecular mechanisms. Further research is essential to understand the impact of e-cigarettes on oral health and make informed regulatory decisions based on reliable scientific evidence.
    Matched MeSH terms: Aerosols
  13. Sailis AB
    Arch Toxicol, 2026 Nov;100(11):5247-5260.
    PMID: 42362750 DOI: 10.1007/s00204-026-04486-w
    E-cigarette use has increased substantially, particularly among adolescents and young adults, yet its long-term respiratory effects remain incompletely understood. E-cigarette aerosol contains biologically active constituents, including nicotine, propylene glycol, vegetable glycerin, flavoring chemicals, aldehydes, metals, particles, and reactive oxygen species, which may disrupt respiratory epithelial homeostasis. This review synthesizes experimental, preclinical, and human-relevant evidence linking e-cigarette aerosol exposure to respiratory epithelial injury, with emphasis on ferroptosis-related mechanisms. Available evidence indicates that e-cigarette aerosol can impair epithelial barrier integrity, alter mucociliary defense, increase MUC5AC expression, induce oxidative stress, and promote inflammatory signaling. Emerging preclinical data suggest that electronic nicotine delivery system exposure may induce ferroptosis-associated lung injury through increased CD71/TFR1 and ACSL4 expression, reduced GPX4, altered lipid profiles, BODIPY-C11-positive lipid peroxidation, epithelial cell death, inflammation, mucus accumulation, emphysema-like pathology, and fibrosis. Mechanistically, e-cigarette aerosol may create a ferroptosis-permissive epithelial environment by promoting redox imbalance, GPX4/GSH/SLC7A11 antioxidant defense impairment, altered iron handling, ACSL4-mediated PUFA-phospholipid remodeling, NRF2/ARE stress responses, mitochondrial dysfunction, and lipid peroxide accumulation. Ferroptotic epithelial injury may further amplify airway inflammation and remodeling through DAMP release, macrophage recruitment, cytokine production, barrier disruption, mucus dysregulation, and extracellular matrix deposition. However, direct human evidence remains limited, and many mechanistic links are extrapolated from cigarette smoke, particulate matter, and broader lung injury models. Future studies should use standardized exposure systems, human-relevant airway and alveolar models, comprehensive ferroptosis markers, and ferroptosis-specific rescue experiments to determine whether ferroptosis is a driver, amplifier, or downstream marker of e-cigarette-associated respiratory injury.
    Matched MeSH terms: Aerosols
  14. Kardia E, Ch'ng ES, Yahaya BH
    J Tissue Eng Regen Med, 2018 02;12(2):e995-e1007.
    PMID: 28105760 DOI: 10.1002/term.2421
    Aerosol-based cell therapy has emerged as a novel and promising therapeutic strategy for treating lung diseases. The goal of this study was to determine the safety and efficacy of aerosol-based airway epithelial cell (AEC) delivery in the setting of acute lung injury induced by tracheal brushing in rabbit. Twenty-four hours following injury, exogenous rabbit AECs were labelled with bromodeoxyuridine and aerosolized using the MicroSprayer® Aerosolizer into the injured airway. Histopathological assessments of the injury in the trachea and lungs were quantitatively scored (1 and 5 days after cell delivery). The aerosol-based AEC delivery appeared to be a safe procedure, as cellular rejection and complications in the liver and spleen were not detected. Airway injury initiated by tracheal brushing resulted in disruption of the tracheal epithelium as well as morphological damage in the lungs that is consistent with acute lung injury. Lung injury scores were reduced following 5 days after AEC delivery (AEC-treated, 0.25  ±  0.06 vs. untreated, 0.53  ±  0.05, P  
    Matched MeSH terms: Aerosols/pharmacology*
  15. Armstrong RW, Rood MJ, Sani S, Mohamed M, Rashid M, Jab AT, et al.
    Asia Pac J Public Health, 2001;13(1):24-9.
    PMID: 12109256 DOI: 10.1177/101053950101300106
    The objective of this study was to establish baseline data about air pollutants potentially related to nasopharyngeal carcinoma (NPC) in the Federal Territory and Selangor, Malaysia. During 1991-1993, ambient air quality was monitored at 42 work sites representing ten industrial sectors: adhesive manufacturing, foundries, latex processing, metalworking, plywood/veneer milling, ricemilling, rubber tire manufacturing, sawmilling, shoemaking, and textile related industries. At each work site, aerosol particle size distributions and concentrations of formaldehyde, benzene, toluene, isopropyl alcohol, and furfural were measured. Mean aerosol particle concentrations ranged from 61 micrograms/m3 in foundries to 5,578 micrograms/m3 in ricemills, with five industries (adhesives, metalworking, ricemilling, sawmilling, and shoemaking) exceeding the US EPA 24-hr ambient air standard for PM-10. Formaldehyde concentrations exceeded the threshold limit value (TLV) in adhesives factories. Other vapours and elements measured were well below TLVs.
    Matched MeSH terms: Aerosols/adverse effects*
  16. Wahid NB, Latif MT, Suratman S
    Chemosphere, 2013 Jun;91(11):1508-16.
    PMID: 23336924 DOI: 10.1016/j.chemosphere.2012.12.029
    This study was conducted to determine the composition and source apportionment of surfactant in atmospheric aerosols around urban and semi-urban areas in Malaysia based on ionic compositions. Colorimetric analysis was undertaken to determine the concentrations of anionic surfactants as Methylene Blue Active Substances (MBAS) and cationic surfactants as Disulphine Blue Active Substances (DBAS) using a UV spectrophotometer. Ionic compositions were determined using ion chromatography for cations (Na(+), NH4(+), K(+), Mg(2+), Ca(2+)) and anions (F(-), Cl(-), NO3(-), SO4(2-)). Principle component analysis (PCA) combined with multiple linear regression (MLR) were used to identify the source apportionment of MBAS and DBAS. Results indicated that the concentrations of surfactants at both sampling sites were dominated by MBAS rather than DBAS especially in fine mode aerosols during the southwest monsoon. Three main sources of surfactants were identified from PCA-MLR analysis for MBAS in fine mode samples particularly in Kuala Lumpur, dominated by motor vehicles, followed by soil/road dust and sea spray. Besides, for MBAS in coarse mode, biomass burning/sea spray were the dominant source followed by motor vehicles/road dust and building material.
    Matched MeSH terms: Aerosols/analysis*
  17. Laila L, Febriyenti F, Salhimi SM, Baie S
    Int Wound J, 2011 Oct;8(5):484-91.
    PMID: 21722317 DOI: 10.1111/j.1742-481X.2011.00820.x
    Haruan (Channa striatus) is a type of fresh water fish in Malaysia that is known to promote wound healing. Haruan water extract has been formulated in an aerosol system which can produce a film for wound dressing. As topical preparation, Haruan spray needs to be evaluated in terms of the possibility to cause irritation reaction or toxic response. Three experiments were carried out to evaluate the safety of Haruan spray which are Primary Skin Irritation test, Intracutaneous test and Systemic Injection test. The result shows that Haruan spray gave no significant responses to all the above tests. The investigation of the effect of Haruan spray as wound dressing in the healing process was performed in Sprague-Dawley rats where 6-cm long full-thickness incision wound and burn wound were made on the back of the animals. Haruan spray was tested and compared with blank formula as control. Tensile strength test of treated wound was carried out at the 3rd, 6th, 9th and 12th day after wounding and treatment. The burn wounds contraction was measured daily for 21 days. Results showed that haruan water extract spray formula is not only effective but also safe for application to both incision and burn wounds.
    Matched MeSH terms: Aerosols/administration & dosage*
  18. Kardia E, Halim NSSA, Yahaya BH
    Methods Mol Biol, 2016;1516:243-255.
    PMID: 27062596 DOI: 10.1007/7651_2016_327
    Aerosol-based cell delivery technique via intratracheal is an effective route for delivering transplant cells directly into the lungs. An aerosol device known as the MicroSprayer(®) Aerosolizer is invented to transform liquid into an aerosol form, which then can be applied via intratracheal administration for drug delivery. The device produces a uniform and concentrated distribution of aerosolized liquid. Using the capability of MicroSprayer(®) Aerosolizer to transform liquid into aerosol form, our group has designed a novel method of cell delivery using an aerosol-based technique. We have successfully delivered skin-derived fibroblast cells and airway epithelial cells into the airway of a rabbit with minimum risk of cell loss and have uniformly distributed the cells into the airway. This chapter illustrates the application of aerosol device to deliver any type of cells for future treatment of lung diseases.
    Matched MeSH terms: Aerosols/therapeutic use
  19. Lara A, Cong Y, Jahrling PB, Mednikov M, Postnikova E, Yu S, et al.
    PLoS Negl Trop Dis, 2019 06;13(6):e0007454.
    PMID: 31166946 DOI: 10.1371/journal.pntd.0007454
    The ability to appropriately mimic human disease is critical for using animal models as a tool for understanding virus pathogenesis. In the case of Nipah virus (NiV), infection of humans appears to occur either through inhalation, contact with or consumption of infected material. In two of these circumstances, respiratory or sinusoidal exposure represents a likely route of infection. In this study, intermediate-size aerosol particles (~7 μm) of NiV-Malaysia were used to mimic potential routes of exposure by focusing viral deposition in the upper respiratory tract. Our previous report showed this route of exposure extended the disease course and a single animal survived the infection. Here, analysis of the peripheral immune response found minimal evidence of systemic inflammation and depletion of B cells during acute disease. However, the animal that survived infection developed an early IgM response with rapid development of neutralizing antibodies that likely afforded protection. The increase in NiV-specific antibodies correlated with an expansion of the B cell population in the survivor. Cell-mediated immunity was not clearly apparent in animals that succumbed during the acute phase of disease. However, CD4+ and CD8+ effector memory cells increased in the survivor with correlating increases in cytokines and chemokines associated with cell-mediated immunity. Interestingly, kinetic changes of the CD4+ and CD8bright T cell populations over the course of acute disease were opposite from animals that succumbed to infection. In addition, increases in NK cells and basophils during convalescence of the surviving animal were also evident, with viral antigen found in NK cells. These data suggest that a systemic inflammatory response and "cytokine storm" are not major contributors to NiV-Malaysia pathogenesis in the AGM model using this exposure route. Further, these data demonstrate that regulation of cell-mediated immunity, in addition to rapid production of NiV specific antibodies, may be critical for surviving NiV infection.
    Matched MeSH terms: Aerosols*
  20. Sathiamurthy N, Balasubbiah N, Dharmaraj B
    Asian Cardiovasc Thorac Ann, 2020 Oct;28(8):495-499.
    PMID: 32787442 DOI: 10.1177/0218492320950898
    BACKGROUND: The Covid-19 pandemic has caused changes in the surgical treatment of non-Covid patients, especially in thoracic surgery because most procedures are aerosol generating. Hospital Kuala Lumpur, where thoracic procedures are performed, was badly affected. We describe our experience in performing aerosol generating procedures safely in thoracic surgery during the Covid-19 era.

    METHODS: Medical records of patients who underwent thoracic surgery from March 18, 2020 to May 17, 2020 were reviewed retrospectively. All patients undergoing thoracic surgery were tested for Covid-19 using the reverse transcriptase polymerase chain reaction method. Patients with malignancy were observed for 10 to 14 days in the ward after testing negative. The healthcare workers donned personal protective equipment for all the cases, and the number of healthcare workers in the operating room was limited to the minimum required.

    RESULTS: A total of 44 procedures were performed in 26 thoracic surgeries. All of these procedures were classified as aerosol generating, and the mean duration of the surgery was 130 ± 43 minutes. None of the healthcare workers involved in the surgery were exposed or infected by Covid-19.

    CONCLUSION: Covid-19 will be a threat for a long time and thoracic surgeons must continue to provide their services, despite having to deal with aerosol generating procedures, in the new normal. Covid-19 testing of all surgical candidates, using the reverse transcriptase polymerase chain reaction, donning full personal protective equipment for healthcare workers, and carefully planned procedures are among the measures suggested to prevent unnecessary Covid-19 exposure in thoracic surgery.

    Matched MeSH terms: Aerosols*
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