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1.
Sci Rep ; 12(1): 1724, 2022 02 02.
Article in English | MEDLINE | ID: mdl-35110635

ABSTRACT

This study introduces localized surface plasmon resonance (L-SPR) mediated heating filter membrane (HFM) for inactivating universal viral particles by using the photothermal effect of plasmonic metal nanoparticles (NPs). Plasmonic metal NPs were coated onto filter membrane via a conventional spray-coating method. The surface temperature of the HFM could be controlled to approximately 40-60 °C at room temperature, owing to the photothermal effect of the gold (Au) NPs coated on them, under irradiation by visible light-emitting diodes. Due to the photothermal effect of the HFMs, the virus titer of H1Npdm09 was reduced by > 99.9%, the full inactivation time being < 10 min, confirming the 50% tissue culture infective dose (TCID50) assay. Crystal violet staining showed that the infectious samples with photothermal inactivation lost their infectivity against Mardin-Darby Canine Kidney cells. Moreover, photothermal inactivation could also be applied to reduce the infectivity of SARS-CoV-2, showing reduction rate of 99%. We used quantitative reverse transcription polymerase chain reaction (qRT-PCR) techniques to confirm the existence of viral genes on the surface of the HFM. The results of the TCID50 assay, crystal violet staining method, and qRT-PCR showed that the effective and immediate reduction in viral infectivity possibly originated from the denaturation or deformation of membrane proteins and components. This study provides a new, simple, and effective method to inactivate viral infectivity, leading to its potential application in various fields of indoor air quality control and medical science.


Subject(s)
COVID-19/virology , Hot Temperature , Light , Metal Nanoparticles , Micropore Filters , SARS-CoV-2 , Surface Plasmon Resonance/methods , Virion , Virus Inactivation , Air Pollution, Indoor , Animals , Cells, Cultured , Dogs , Gold/chemistry , SARS-CoV-2/genetics , SARS-CoV-2/pathogenicity
2.
BMC Microbiol ; 22(1): 33, 2022 01 20.
Article in English | MEDLINE | ID: mdl-35057747

ABSTRACT

BACKGROUND: Sequential membrane filtration as a pre-processing step for capturing sediment-associated microorganisms could provide good quality and integrity DNA that can be preserved and kept at ambient temperatures before community profiling through culture-independent molecular techniques. However, the effects of sample pre-processing via filtration on DNA-based profiling of sediment-associated microbial community diversity and composition are poorly understood. Specifically, the influences of pre-processing on the quality and quantity of extracted DNA, high-throughput DNA sequencing reads, and detected microbial taxa need further evaluation. RESULTS: We assessed the impact of pre-processing freshwater sediment samples by sequential membrane filtration (from 10, 5 to 0.22 µm pore size) for 16S rRNA-based community profiling of sediment-associated microorganisms. Specifically, we examined if there would be method-driven differences between non- and pre-processed sediment samples regarding the quality and quantity of extracted DNA, PCR amplicon, resulting high-throughput sequencing reads, microbial diversity, and community composition. We found no significant difference in the qualities and quantities of extracted DNA and PCR amplicons, and the read abundance after bioinformatics processing (i.e., denoising and chimeric-read filtering steps) between the two methods. Although the non- and pre-processed sediment samples had more unique than shared amplicon sequence variants (ASVs), we report that their shared ASVs accounted for 74% of both methods' absolute read abundance. More so, at the genus level, the final collection filter identified most of the genera (95% of the reads) captured from the non-processed samples, with a total of 51 false-negative (2%) and 59 false-positive genera (3%). We demonstrate that while there were differences in shared and unique taxa, both methods revealed comparable microbial diversity and community composition. CONCLUSIONS: Our observations highlight the feasibility of pre-processing sediment samples for community analysis and the need to further assess sampling strategies to help conceptualize appropriate study designs for sediment-associated microbial community profiling.


Subject(s)
Bacteria/genetics , Bacteria/isolation & purification , DNA, Bacterial/genetics , Geologic Sediments/microbiology , Microbiota/genetics , RNA, Ribosomal, 16S/genetics , Bacteria/classification , Computational Biology , DNA, Bacterial/isolation & purification , DNA, Bacterial/standards , High-Throughput Nucleotide Sequencing , Micropore Filters , Phylogeny , Sequence Analysis, DNA/methods , Specimen Handling/methods
3.
Eur J Pharm Biopharm ; 169: 113-124, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34637918

ABSTRACT

Innovative technologies have been designed to improve efficacy and safety of chemical UV filters. Encapsulation can enhance efficacy and reduce transdermal permeation and systemic exposure. The aims of this work were (i) to determine the cutaneous biodistribution of avobenzone (AVO), oxybenzone (OXY), and octyl methoxycinnamate (OMC) incorporated in mesoporous silica SBA-15 and (ii) to perform preclinical (in vitro) and (iii) clinical safety studies to demonstrate their innocuity and to evaluate sun protection factor (SPF) in humans. Skin penetration studies showed that deposition of OXY and AVO in porcine and human skin after application of stick formulation with incorporated filters (stick incorporated filters) was significantly lower than from a marketed (non-encapsulated) stick. Cutaneous deposition and transdermal permeation of OXY in and across human skin were 3.8-and 13.4- fold lower, respectively, after application of stick entrapped filters. Biodistribution results showed that encapsulation in SBA-15 decreased AVO and OXY penetration reaching porcine and human dermis. Greater deposition (and permeation) of OXY in porcine skin than in human skin, pointed to the role of follicular transport. Stick incorporated filters had good biocompatibility in vivo and safety profiles, even under sun-exposed conditions. Entrapment of UV filters improved the SPF by 26% and produced the same SPF profile as a marketed stick. Overall, the results showed that SBA-15 enabled safety and efficacy of UV filters to be increased.


Subject(s)
Benzophenones/pharmacokinetics , Cinnamates/pharmacokinetics , Propiophenones/pharmacokinetics , Silicon Dioxide/pharmacology , Tissue Distribution , Administration, Cutaneous , Animals , Drug Compounding/methods , Drug Evaluation, Preclinical , Humans , Micropore Filters , Skin Absorption , Sun Protection Factor , Sunscreening Agents/pharmacokinetics , Swine
4.
J Clin Apher ; 36(6): 841-848, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34486748

ABSTRACT

BACKGROUND AND OBJECTIVES: Therapeutic plasma exchange (TPE) is a blood purification treatment capable of removing large molecular weight substances from plasma. It is commonly used for the removal of circulating pathogenic immunoglobulins presumed to be the cause of many autoimmune diseases. TPE can be performed with a membrane-based system (mTPE) or a centrifugal-based system (cTPE). When plasma separation is performed with a membrane, filter clotting can lead to longer treatment time, higher cost and can negatively impact patient satisfaction. In this study, we examine the operational characteristics that might influence filter life. DESIGN, SETTING, PARTICIPANTS, & MEASURES: We report on 24 patients, with a total of 135 mTPE treatments in a single tertiary care academic center using the NxStage machine. The study focuses on treatment specific parameters that may lead to procedure failure. The main parameters of interest were transmembrane pressure (TMP) and the filtration fraction as displayed on the machine (FFd) compared to the calculated filtration fraction (FFc). Primary outcome was to measure whether TMP, FFc, and FFd influenced filter survival. Secondary outcomes included factors that might have indirectly resulted in filter failure, including hematocrit (Hct), platelet count, heparin use, and intra-treatment calcium administration. RESULTS: In this study, we demonstrated that machine displayed filtration fractions (FFd) were lower than FFc and this difference was significantly larger in TPE sessions that experienced a clotting event (7.58 vs 6.22, P = .031). TPE sessions that clotted had a higher mean TMP (57.48 mmHg vs 44.43 mmHg, P = .001) and clotting events tended to have a lower mean blood flow rate (175.83 mL/min vs 189.55 mL/min, P = .002). In TPE sessions that received prefilter calcium administration, a higher mean dose of calcium gluconate was found in the sessions that experienced clotting (3.27 g vs 2.70 g, P = .013). Patients who experienced at least one clotting event were noted to be heavier than those patients without any clotting events (91.52 kg vs 72.15 kg, P = .040). Prefilter heparin administration was not associated with a lower incidence of filter clotting. We did not find a statistically significant difference in clotting events based upon type of intravenous access, pretreatment hematocrit, or pretreatment platelet counts. CONCLUSION: Among patients undergoing mTPE, machine FFd on the NxStage system are consistently lower than FFc. Treatments where there was a greater difference between displayed and FFc had a greater likelihood of filter clotting. Treatments with higher TMP were associated with failed treatments. Prefilter calcium administration during treatment was associated with increased filter clotting. Lower blood flow rates and higher patient weight were also associated with increased filter clotting. Prefilter heparin administration did not reduce the incidence of filter clotting.


Subject(s)
Filtration/methods , Hemodynamics , Micropore Filters , Plasma Exchange/adverse effects , Plasma Exchange/methods , Treatment Failure , Adult , Aged , Aged, 80 and over , Calcium/administration & dosage , Female , Filtration/instrumentation , Hematocrit , Heparin/administration & dosage , Humans , Male , Middle Aged , Plasma Exchange/instrumentation , Platelet Count , Tertiary Care Centers , Young Adult
5.
Crit Care ; 25(1): 299, 2021 08 19.
Article in English | MEDLINE | ID: mdl-34412667

ABSTRACT

BACKGROUND: Coronavirus disease 2019 (COVID-19) may predispose patients to thrombotic events. The best anticoagulation strategy for continuous renal replacement therapy (CRRT) in such patients is still under debate. The purpose of this study was to evaluate the impact that different anticoagulation protocols have on filter clotting risk. METHODS: This was a retrospective observational study comparing two different anticoagulation strategies (citrate only and citrate plus intravenous infusion of unfractionated heparin) in patients with acute kidney injury (AKI), associated or not with COVID-19 (COV + AKI and COV - AKI, respectively), who were submitted to CRRT. Filter clotting risks were compared among groups. RESULTS: Between January 2019 and July 2020, 238 patients were evaluated: 188 in the COV + AKI group and 50 in the COV - AKI group. Filter clotting during the first filter use occurred in 111 patients (46.6%). Heparin use conferred protection against filter clotting (HR = 0.37, 95% CI 0.25-0.55), resulting in longer filter survival. Bleeding events and the need for blood transfusion were similar between the citrate only and citrate plus unfractionated heparin strategies. In-hospital mortality was higher among the COV + AKI patients than among the COV - AKI patients, although it was similar between the COV + AKI patients who received heparin and those who did not. Filter clotting was more common in patients with D-dimer levels above the median (5990 ng/ml). In the multivariate analysis, heparin was associated with a lower risk of filter clotting (HR = 0.28, 95% CI 0.18-0.43), whereas an elevated D-dimer level and high hemoglobin were found to be risk factors for circuit clotting. A diagnosis of COVID-19 was marginally associated with an increased risk of circuit clotting (HR = 2.15, 95% CI 0.99-4.68). CONCLUSIONS: In COV + AKI patients, adding systemic heparin to standard regional citrate anticoagulation may prolong CRRT filter patency by reducing clotting risk with a low risk of complications.


Subject(s)
Acute Kidney Injury/drug therapy , Citric Acid/pharmacology , Continuous Renal Replacement Therapy/instrumentation , Heparin/pharmacology , Micropore Filters/standards , Acute Kidney Injury/epidemiology , Acute Kidney Injury/etiology , Adult , COVID-19/complications , COVID-19/epidemiology , Citric Acid/adverse effects , Citric Acid/therapeutic use , Cohort Studies , Continuous Renal Replacement Therapy/methods , Continuous Renal Replacement Therapy/statistics & numerical data , Female , Heparin/adverse effects , Heparin/therapeutic use , Humans , Kaplan-Meier Estimate , Male , Micropore Filters/statistics & numerical data , Middle Aged , Proportional Hazards Models , Retrospective Studies
6.
Nat Nanotechnol ; 16(8): 918-925, 2021 08.
Article in English | MEDLINE | ID: mdl-34083772

ABSTRACT

Minimizing the spread of viruses in the environment is the first defence line when fighting outbreaks and pandemics, but the current COVID-19 pandemic demonstrates how difficult this is on a global scale, particularly in a sustainable and environmentally friendly way. Here we introduce and develop a sustainable and biodegradable antiviral filtration membrane composed of amyloid nanofibrils made from food-grade milk proteins and iron oxyhydroxide nanoparticles synthesized in situ from iron salts by simple pH tuning. Thus, all the membrane components are made of environmentally friendly, non-toxic and widely available materials. The membrane has outstanding efficacy against a broad range of viruses, which include enveloped, non-enveloped, airborne and waterborne viruses, such as SARS-CoV-2, H1N1 (the influenza A virus strain responsible for the swine flu pandemic in 2009) and enterovirus 71 (a non-enveloped virus resistant to harsh conditions, such as highly acidic pH), which highlights a possible role in fighting the current and future viral outbreaks and pandemics.


Subject(s)
Amyloid/chemistry , Antiviral Agents/pharmacology , Ferric Compounds/chemistry , Micropore Filters , Nanoparticles/chemistry , Amyloid/pharmacology , Antiviral Agents/chemistry , Ferric Compounds/pharmacology , Humans , Lactoglobulins/chemistry , Micropore Filters/virology , Virus Inactivation/drug effects , Viruses/classification , Viruses/drug effects , Viruses/isolation & purification , Water Purification
7.
Pharm Res ; 38(1): 155-163, 2021 Jan.
Article in English | MEDLINE | ID: mdl-33438097

ABSTRACT

PURPOSE: Sterile filtration can be a particular challenge when processing very large glycoconjugate vaccines. The objective of this study was to examine the sterile filtration performance of a series of glycoconjugate vaccines produced by coupling different polysaccharide serotypes to an immunogenic protein. METHODS: Sterile filtration was performed at constant filtrate flux using 0.22 µm pore size Durapore® polyvinylidene fluoride membranes. Glycoconjugates were characterized by dynamic light scattering, rheological measurements, and nanoparticle tracking analysis (NTA). Confocal microscopy was used to examine glycoconjugate capture profiles within the membrane. Transmembrane pressure data were analyzed using a recently developed fouling model. RESULTS: All glycoconjugates deposited in a narrow band near the entrance of the Durapore® membranes. The rate of fouling varied significantly for the different serotypes, with the fouling parameter correlated with the fraction of glycoconjugates larger than 200 nm in size. CONCLUSIONS: The fouling behavior and sterile filter capacity of the different glycoconjugate serotypes are determined primarily by the presence of large species (>200 nm in size) as determined by nanoparticle tracking analysis. The modified intermediate pore blockage model provides a framework for predicting the sterile filtration performance for these glycoconjugate vaccines.


Subject(s)
Drug Compounding/standards , Drug Contamination/prevention & control , Glycoconjugates/standards , Vaccines, Conjugate/standards , Drug Compounding/instrumentation , Drug Compounding/methods , Filtration/instrumentation , Filtration/standards , Glycoconjugates/chemistry , Membranes, Artificial , Micropore Filters , Particle Size , Vaccines, Conjugate/chemistry
8.
J Thromb Thrombolysis ; 51(4): 966-970, 2021 May.
Article in English | MEDLINE | ID: mdl-33026569

ABSTRACT

Coronavirus disease 2019 (COVID-19) appears to be associated with increased arterial and venous thromboembolic disease. These presumed abnormalities in hemostasis have been associated with filter clotting during continuous renal replacement therapy (CRRT). We aimed to characterize the burden of CRRT filter clotting in COVID-19 infection and to describe a CRRT anticoagulation protocol that used anti-factor Xa levels for systemic heparin dosing. Multi-center study of consecutive patients with COVID-19 receiving CRRT. Primary outcome was CRRT filter loss. Sixty-five patients were analyzed, including 17 using an anti-factor Xa protocol to guide systemic heparin dosing. Fifty-four out of 65 patients (83%) lost at least one filter. Median first filter survival time was 6.5 [2.5, 33.5] h. There was no difference in first or second filter loss between the anti-Xa protocol and standard of care anticoagulation groups, however fewer patients lost their third filter in the protocolized group (55% vs. 93%) resulting in a longer median third filter survival time (24 [15.1, 54.2] vs. 17.3 [9.5, 35.1] h, p = 0.04). The rate of CRRT filter loss is high in COVID-19 infection. An anticoagulation protocol using systemic unfractionated heparin, dosed by anti-factor Xa levels is reasonable approach to anticoagulation in this population.


Subject(s)
Biomarkers, Pharmacological/analysis , COVID-19 , Continuous Renal Replacement Therapy , Critical Illness/therapy , Drug Monitoring/methods , Heparin , Micropore Filters/adverse effects , Anticoagulants/administration & dosage , Anticoagulants/adverse effects , Blood Coagulation/drug effects , COVID-19/blood , COVID-19/physiopathology , COVID-19/therapy , Clinical Protocols , Continuous Renal Replacement Therapy/adverse effects , Continuous Renal Replacement Therapy/methods , Dose-Response Relationship, Drug , Equipment Failure Analysis , Factor Xa/analysis , Female , Heparin/administration & dosage , Heparin/adverse effects , Humans , Male , Middle Aged , SARS-CoV-2
9.
Small GTPases ; 12(4): 294-310, 2021 07.
Article in English | MEDLINE | ID: mdl-32569510

ABSTRACT

As normal cells become cancer cells, and progress towards malignancy, they become progressively softer. Advantages of this change are that tumour cells become more deformable, and better able to move through narrow constraints. We designed a positive selection strategy that enriched for cells which could move through narrow diameter micropores to identify cell phenotypes that enabled constrained migration. Using human MDA MB 231 breast cancer and MDA MB 435 melanoma cancer cells, we found that micropore selection favoured cells with relatively higher Ras/Raf/MEK/ERK mitogen-activated protein kinase (MAPK) signalling, which affected actin cytoskeleton organization, focal adhesion density and cell elasticity. In this follow-up study, we provide further evidence that selection through micropores enriched for cells with altered cell morphology and adhesion. Additional analysis of RNA sequencing data revealed a set of transcripts associated with small cell size that was independent of constrained migration. Gene set enrichment analysis identified the 'matrisome' as the most significantly altered gene set linked with small size. When grown as orthotopic xenograft tumours in immunocompromised mice, micropore selected cells grew significantly faster than Parent or Flow-Sorted cells. Using mathematical modelling, we determined that there is an interaction between 1) the cell to gap size ratio; 2) the bending rigidity of the cell, which enable movement through narrow gaps. These results extend our previous conclusion that Ras/Raf/MEK/ERK MAPK signalling has a significant role in regulating cell biomechanics by showing that the selective pressure of movement through narrow gaps also enriches for increased tumour growth in vivo.


Subject(s)
Breast Neoplasms/pathology , Melanoma/pathology , Micropore Filters , Mitogen-Activated Protein Kinase Kinases/metabolism , Mitogen-Activated Protein Kinases/metabolism , Proto-Oncogene Proteins c-raf/metabolism , ras Proteins/metabolism , Animals , Apoptosis , Biomarkers, Tumor/genetics , Biomarkers, Tumor/metabolism , Breast Neoplasms/genetics , Breast Neoplasms/metabolism , Cell Proliferation , Female , Gene Expression Regulation, Neoplastic , Humans , MAP Kinase Signaling System , Melanoma/genetics , Melanoma/metabolism , Mice , Mitogen-Activated Protein Kinase Kinases/genetics , Mitogen-Activated Protein Kinases/genetics , Proto-Oncogene Proteins c-raf/genetics , Tumor Cells, Cultured , Xenograft Model Antitumor Assays , ras Proteins/genetics
10.
Rev. bras. oftalmol ; 80(4): e0018, 2021. tab, graf
Article in English | LILACS | ID: biblio-1288632

ABSTRACT

ABSTRACT Objective: To describe ocular surface findings in impression cytology obtained from healthy rabbit conjunctiva treated with interferon alpha-2b eyedrop, and compare them to findings after use of mitomycin C 0.02%. Methods: An experimental study using a rabbit model was performed between September 2013 and October 2014 at the Faculdade de Medicina de Marília, Universidade Federal de São Paulo, Clínica de Olhos Moacir Cunha. Thirty New Zealand white rabbits were divided into 6 groups and received interferon alpha-2b or mitomycin C 0.02%. Impression cytology (IC) was performed prior to topical applications and at15, 30 and 60 days of use. The following variables were analyzed in impression cytology: goblet cells, cellularity, cell-to-cell adhesion, nucleus/cytoplasm ratio, nuclear chromatin, inflammatory cells keratinization, and cytomegaly. Results: The major findings in impression cytology after us of interferon alpha-2b included loss of goblet cells (50.8%), reduced cell-to-cell adhesion (26.2%), abnormal nucleus/cytoplasm ratio (20%) and reduced cellularity (15.4%). After use of mitomycin C 0.02%, the most common changes included loss of goblet cells (46.2%), abnormal nucleus/cytoplasm ratio (25.6%), less cell-to-cell adhesion (23.1%), and reduced cellularity (20.5%). There were no significant differences in any variable when comparing impression cytology after interferon alpha-2b and after mitomycin C 0.02%. Goblet cell loss was more pronounced at days 30 and 60, as compared to impression cytology at day 15 for both drugs. Conclusion: The loss of goblet cells, reduced cell-to-cell adhesion and cellularity, along with abnormal nucleus/cytoplasm ratio were the most common findings in impression cytology after use of interferon alpha-2b. These findings are similar to those described for use of mitomycin C 0.02%. ..


RESUMO Objetivo: Descrever os achados em citologia de impressão de conjuntiva sadia de coelho submetida ao uso de colírio de interferon alfa-2b e compará-los ao que foi encontrado após uso da mitomicina C 0,02%. Métodos: Estudo experimental realizado em modelo animal no período entre setembro de 2013 e outubro de 2014 nas dependências da Faculdade de Medicina de Marília, da Universidade Federal de São Paulo e da Clínica de Olhos Moacir Cunha. Trinta coelhos albinos da raça Nova Zelândia foram divididos em seis grupos e receberam interferon alfa-2b ou mitomicina C. A citologia de impressão foi realizada antes do início dos colírios e após 15, 30, 60 dias de seu uso. As seguintes variáveis foram analisadas na citologia de impressão: células caliciformes, celularidade, adesão intercelular, razão núcleo/citoplasma, cromatina, células inflamatórias, queratinização e citomegalia. Resultados: Os principais achados na citologia de impressão após o uso do interferon alfa-2b foram a redução de células caliciformes (50,8%), a diminuição da adesão intercelular (26,2%), a alteração da razão N/C (20%) e a redução da celularidade (15,4%). Após o uso da mitomicina C 0,02%, foram mais frequentes a redução das células caliciformes (46,2%), a alteração da razão N/C (25,6%), a adesão intercelular (23,1%) e a redução da celularidade (20,5%). Não houve diferença estatisticamente significante para nenhuma das variáveis estudas quando se compararam as citologias de impressão após interferon alfa-2b com as citologias de impressão após mitomicina C 0,02%. Independentemente da substância utilizada, as citologias colhidas 30 e 60 dias após início das drogas apresentaram maior redução de células caliciformes quando comparadas com as citologias de impressão colhidas após 15 dias. Conclusão: A redução das células caliciformes, a diminuição da adesão intercelular, a alteração da razão N/C e a diminuição da celularidade foram as alterações mais frequentes na citologia de impressão colhida após o uso de interferon alfa-2b. Os achados em citologias de impressão após o uso de interferon alfa-2b são semelhantes àqueles encontrados após o uso da mitomicina C 0,02%.


Subject(s)
Animals , Rabbits , Mitomycin/pharmacology , Conjunctiva/cytology , Cornea/cytology , Interferon alpha-2/pharmacology , Carcinoma, Squamous Cell/drug therapy , Cellulose , Cytological Techniques , Mitomycin/therapeutic use , Conjunctiva/drug effects , Conjunctiva/ultrastructure , Conjunctival Neoplasms/drug therapy , Cell Culture Techniques , Cornea/drug effects , Cornea/ultrastructure , Cytodiagnosis/methods , Interferon alpha-2/therapeutic use , Micropore Filters
11.
Biocontrol Sci ; 25(4): 223-230, 2020.
Article in English | MEDLINE | ID: mdl-33281180

ABSTRACT

Tap water contamination is a growing concern in healthcare facilities, and despite chlorination, tap water in these facilities contains several pathogenic microorganisms causing healthcare-associated waterborne infections or nosocomial outbreaks. Shower units are particularly prone to contamination as they are conducive for bacterial growth and can even produce bioaerosols containing pathogenic bacteria. Shower units coupled with point-of-use (POU) water filters are a simple and safe option; however, their efficacy has been under-reported. Therefore, we determined the efficacy of showerheads attached with a POU filter capsule in preventing infections in our hospital. We investigated the presence of pathogenic bacteria in water sampled from three shower units. After replacing the original shower units with new ones incorporated with a sterile-grade water filter capsule (0.2 µm; QPoint™), the water samples were analyzed for up to 2 months. The POU filters removed several pathogenic bacteria (Mycobacterium, Pseudomonas, Stenotrophomonas, Aeromonas, and Klebsiella spp.). Filter effectiveness depends on regional water quality and we believe that effective tap water treatment combined with the use of POU filters (introduced at a reasonable cost in healthcare facilities) can considerably minimize waterborne diseases in hospitals and improve patient care.


Subject(s)
Capsules , Cross Infection/prevention & control , Micropore Filters , Water Microbiology , Waterborne Diseases/prevention & control , Filtration/methods , Hospitals , Humans , Japan , Water Purification
12.
J Bioenerg Biomembr ; 52(6): 495-504, 2020 12.
Article in English | MEDLINE | ID: mdl-33190172

ABSTRACT

The light-induced functioning of photosynthetic pigment-protein complex of photosystem II (PSII) is linked to the vectorial translocation of charges across the membrane, which results in the formation of voltage. Direct measurement of the light-induced voltage (∆V) generated by spinach oxygen-evolving PSII core complexes adsorbed onto a Millipore membrane filter (MF) on an indium tin oxide (ITO) electrode under continuous illumination has been performed. PSII was shown to participate in electron transfer from water to the ITO electrode, resulting in ∆V generation. No photovoltage was detected in PSII deprived of the water-oxidizing complex. The maximal and stable photoelectric signal was observed in the presence of disaccharide trehalose and 2,6-dichloro-1,4-benzoquinone, acting as a redox mediator between the primary quinone acceptor QA of PSII and electrode surface. Long time preservation of the steady-state photoactivity at room temperature in a simple in design ITO|PSII-MF|ITO system may be related to the retention of water molecules attached to the PSII surface in the presence of trehalose.


Subject(s)
Electron Transport/physiology , Micropore Filters/standards , Photosystem II Protein Complex/metabolism , Tin Compounds/metabolism , Electrodes , Humans
13.
J Dairy Sci ; 103(11): 9992-10000, 2020 Nov.
Article in English | MEDLINE | ID: mdl-32921470

ABSTRACT

Current cleaning and sanitation protocols may not be adequately effective in cleaning separation membranes and can result in the formation of resilient multispecies biofilms. The matured biofilms may result in a bacterial predominance with resilient strains on membranes with a prolonged use. In our previous study, we isolated organisms such as Bacillus subtilis, Bacillus licheniformis, Exiguobacterium aurantiacum, and Acinetobacter radioresistens from an 18-mo-old reverse osmosis membrane. The competitive exclusion studies revealed the predominance of B. subtilis within the membrane biofilm microflora. This study investigated the antimicrobial activity of the B. subtilis isolate as a potential cause of its predominance. The culture isolate was propagated in tryptic soy broth at 37°C, and microfiltered to prepare cell-free extracts (CFE) at 8-, 10-, 12-, 14-, 16-, and 18-h intervals. The CFE were freeze-dried and suspended in minimum quantities of HPLC-grade water to prepare concentrated solutions. The antimicrobial activities of CFE were tested using the agar-well assay against the biofilm constitutive microflora. The experiments were conducted in triplicates and means were compared for significant differences using a general linear mixed model procedure. The results indicated the highest antimicrobial activity of 12-h CFE of B. subtilis against other constitutive microflora such as Exiguobacterium sp., E. auranticum, and A. radioresistens, with average inhibition zone sizes of 16.5 ± 0.00, 16.25 ± 0.66, and 20.6 ± 0.00 mm, respectively. Upon treatment with proteinase K, the CFE completely lost its antimicrobial activity, establishing it to be a proteinaceous compound. The AA profiling revealed the total crude protein in CFE to be 51% (wt/wt), with its major constituent as glutamic acid (11.30% wt/wt). The freeze-dried CFE was thermally stable on exposure to the common temperature used for sanitizer applications (23.8°C for 5 and 10 min) and over a pH range of 3.0 to 6.3. The study helped us understand the role of the antimicrobial compound produced by B. subtilis as a potential cause of its predominance within the biofilm constitutive microflora.


Subject(s)
Anti-Infective Agents/pharmacology , Bacillus subtilis/chemistry , Biofilms/growth & development , Whey/microbiology , Acinetobacter/growth & development , Acinetobacter/isolation & purification , Anti-Infective Agents/isolation & purification , Bacillus licheniformis/growth & development , Bacillus licheniformis/isolation & purification , Bacillus subtilis/growth & development , Bacillus subtilis/isolation & purification , Bacillus subtilis/physiology , Biofilms/drug effects , Caseins , Micropore Filters/microbiology , Osmosis , Protein Hydrolysates
14.
Sci Rep ; 10(1): 15525, 2020 09 23.
Article in English | MEDLINE | ID: mdl-32968098

ABSTRACT

A rapid method for screening pathogens can revolutionize health care by enabling infection control through medication before symptom. Here we report on label-free single-cell identifications of clinically-important pathogenic bacteria by using a polymer-integrated low thickness-to-diameter aspect ratio pore and machine learning-driven resistive pulse analyses. A high-spatiotemporal resolution of this electrical sensor enabled to observe galvanotactic response intrinsic to the microbes during their translocation. We demonstrated discrimination of the cellular motility via signal pattern classifications in a high-dimensional feature space. As the detection-to-decision can be completed within milliseconds, the present technique may be used for real-time screening of pathogenic bacteria for environmental and medical applications.


Subject(s)
Bacterial Infections/diagnosis , Biosensing Techniques/methods , Machine Learning , Bacillus cereus/ultrastructure , Bacterial Infections/microbiology , Electronics , Escherichia coli/ultrastructure , Micropore Filters , Microscopy, Electron, Scanning , Pseudomonas fluorescens/ultrastructure , Salmonella enterica/ultrastructure , Staphylococcus aureus/ultrastructure
15.
J Virol Methods ; 284: 113939, 2020 10.
Article in English | MEDLINE | ID: mdl-32673640

ABSTRACT

Among the enteric viruses implicated in waterborne outbreaks, human norovirus and hepatitis A virus (HAV) are a serious public health issue. Most foodborne viruses are difficult or currently unlikely to cultivate. Because of the lack of a cell culture method, real-time reverse transcriptase PCR is commonly used for the detection of norovirus in foodstuffs and environmental samples. Due to low infectious doses in humans and low virus concentration in water sample, filter adsorption methods were used for concentrating viruses from water. The ISO (Anonymous, ISO 15216-1, 2017) describes standardized molecular methods for detecting HAV and norovirus in bottled water. This method includes a two-step procedure: concentrating the virus using a microporous electropositive filter (47 mm diameter, 0.45 µm pore size) then molecular detection. The Zetapor filter, which had a charged membrane with a pore size of 0.45 µm, was commonly used in the past to concentrate viruses from water or from salad leaves following virus elution. But, unfortunately, the Zetapor filter is no longer marketed and it is therefore necessary to assess an alternative filter. The aim of this study was to compare the ability of two electropositive filters with a pore size of 0.45 µm or 0.22 µm and one uncharged filter (0.45 µm) to recover norovirus and HAV from two different types of drinking water (bottled water and tap water) with the adsorption-elution method proposed by ISO (Anonymous, ISO 15216-1, 2017) (method A) and with direct viral extraction using filters (method B). The mean extraction yields for norovirus and HAV calculated with RNA extracts ranged from 0.2 % - 4.81 % with method A and from 5.05 % - 53.58 % with method B, and did not differ significantly between the two types of drinking water tested. For method B, the mean extraction yields for HAV and norovirus were evaluated according to results from the three filters used. The recovery rate of HAV and norovirus ranged between 3.47 % and 62.41 % with the 0.45 µm electropositive filter and were higher than the other filters. The 0.45 µm electropositive filter could be used to concentrate viruses for routine viral monitoring of drinking water for researchers who want to adopt the method in their lab routine.


Subject(s)
Drinking Water/virology , Filtration/instrumentation , Filtration/methods , Viruses/isolation & purification , Adsorption , Food Microbiology , Humans , Micropore Filters , RNA, Viral/analysis , RNA, Viral/genetics , Reverse Transcriptase Polymerase Chain Reaction , Viruses/classification , Viruses/genetics
16.
J Biomater Appl ; 35(1): 49-58, 2020 07.
Article in English | MEDLINE | ID: mdl-32223499

ABSTRACT

Here, we describe a novel microfilter device to capture circulating tumor cells in an efficient and low-cost manner. Then, we validated the safety and clinical utility of the novel microfilter device. We next performed mutation analysis from circulating tumor cells collected from lung cancer patients using this new device. Our results indicate that this microfilter system can be used to investigate the genome landscape of circulating tumor cells collected from lung cancer patients. Further, our results highlight a proof-of-concept demonstration indicating that circulating tumor cell can be used for mutation profiling during tumor evolution, therapy prediction, and monitoring, with immediate clinical applicability.


Subject(s)
Cell Separation/instrumentation , Lung Neoplasms/pathology , Neoplastic Cells, Circulating/pathology , Cell Line, Tumor , Equipment Design , Humans , Lung Neoplasms/blood , Lung Neoplasms/genetics , Micropore Filters , Mutation , Neoplastic Cells, Circulating/metabolism
17.
Indian Pediatr ; 56(11): 974-976, 2019 11 15.
Article in English | MEDLINE | ID: mdl-31729332

ABSTRACT

A 6-year-old girl presented with rhabdomyolysis following a febrile illness. Polymerase chain reaction (PCR) for Influenza B and enterovirus was positive. Her serum creatine kinase (CK) and myoglobin levels were very high. She developed myoglobinuria with oliguria leading to acute kidney injury. Continuous renal replacement therapy along with Cytosorb filter resulted in good outcome.


Subject(s)
Acute Kidney Injury , Continuous Renal Replacement Therapy/methods , Enterovirus/isolation & purification , Influenza B virus/isolation & purification , Renal Replacement Therapy/methods , Rhabdomyolysis , Virus Diseases , Acute Kidney Injury/blood , Acute Kidney Injury/etiology , Acute Kidney Injury/physiopathology , Acute Kidney Injury/therapy , Child , Creatine Kinase/blood , Female , Humans , Micropore Filters , Myoglobin/blood , Rhabdomyolysis/diagnosis , Rhabdomyolysis/etiology , Treatment Outcome , Virus Diseases/complications , Virus Diseases/diagnosis
18.
Am J Vet Res ; 80(9): 852-861, 2019 Sep.
Article in English | MEDLINE | ID: mdl-31449450

ABSTRACT

OBJECTIVE: To determine whether passage of whole blood through a microaggregate filter by use of a syringe pump would damage canine erythrocytes. SAMPLE: Blood samples obtained from 8 healthy client-owned dogs. PROCEDURES: Whole blood was passed through a standard microaggregate filter by use of a syringe pump at 3 standard administration rates (12.5, 25, and 50 mL/h). Prefilter and postfilter blood samples were collected at the beginning and end of a simulated transfusion. Variables measured at each time point included erythrocyte osmotic fragility, mean corpuscular fragility, RBC count, hemoglobin concentration, RBC distribution width, and RBC morphology. In-line pressure when blood passed through the microaggregate filter was measured continuously throughout the simulated transfusion. After the simulated transfusion was completed, filters were visually analyzed by use of scanning electron microscopy. RESULTS: Regardless of administration rate, there was no significant difference in mean corpuscular fragility, RBC count, hemoglobin concentration, or RBC distribution width between prefilter and postfilter samples. Additionally, there were no differences in in-line pressure during the simulated transfusion among administration rates. Echinocytes were the erythrocyte morphological abnormality most commonly observed at the end of the transfusion at administration rates of 12.5 and 25 mL/h. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that regardless of the administration rate, the microaggregate filter did not alter fragility of canine RBCs, but may have altered the morphology. It appeared that the microaggregate filter would not contribute to substantial RBC damage for transfusions performed with a syringe pump.


Subject(s)
Blood Transfusion/veterinary , Dogs/blood , Erythrocytes/ultrastructure , Micropore Filters/veterinary , Animals , Female , In Vitro Techniques/veterinary , Male , Microscopy, Electron, Scanning , Syringes/veterinary
19.
Carbohydr Polym ; 222: 114970, 2019 Oct 15.
Article in English | MEDLINE | ID: mdl-31320043

ABSTRACT

Herein, we report novel macroporous membranes doped with micro-mesoporous ß-cyclodextrin polymers (ß-CDP), named ß-CDP membranes, for water decontamination by the flow-through process. These membranes combine excellent adsorption behavior of ß-CDP and the advantages of membranes filtration including low energy consumption and easy scale-up. Filtration adsorption results demonstrated that the optimal ß-CDP membrane removed > 99.9% of bisphenol A with ultrahigh water flux (3000 L m-2 h-1) or high concentration (50 mg L-1). The dynamic adsorption capacity of the membrane was close to the static maximum adsorption capacity of membrane, suggesting the effective accessibility of adsorption sites. The outstanding adsorption performance was attributed to the synergistic effect of the fast adsorption of ß-CDP, abundant ß-CDP nanoparticles and large contact area offered by spongy pores. Furthermore, not only single other organic micropollutants but also mixture was completely removed by the ß-CDP membranes. In addition, the membranes were easily regenerated by simple ethanol filtration.


Subject(s)
Cellulose/chemistry , Cyclodextrins/chemistry , Filtration/methods , Micropore Filters , Water Purification/methods , beta-Cyclodextrins/chemistry , Adsorption , Benzhydryl Compounds/chemistry , Phenols/chemistry , Water Pollutants, Chemical/analysis
20.
J Cell Sci ; 132(11)2019 05 31.
Article in English | MEDLINE | ID: mdl-31152052

ABSTRACT

Cancer cells are softer than the normal cells, and metastatic cells are even softer. These changes in biomechanical properties contribute to cancer progression by facilitating cell movement through physically constraining environments. To identify properties that enabled passage through physical constraints, cells that were more efficient at moving through narrow membrane micropores were selected from established cell lines. By examining micropore-selected human MDA MB 231 breast cancer and MDA MB 435 melanoma cancer cells, membrane fluidity and nuclear elasticity were excluded as primary contributors. Instead, reduced actin cytoskeleton anisotropy, focal adhesion density and cell stiffness were characteristics associated with efficient passage through constraints. By comparing transcriptomic profiles between the parental and selected populations, increased Ras/MAPK signalling was linked with cytoskeleton rearrangements and cell softening. MEK inhibitor treatment reversed the transcriptional, cytoskeleton, focal adhesion and elasticity changes. Conversely, expression of oncogenic KRas in parental MDA MB 231 cells, or oncogenic BRaf in parental MDA MB 435 cells, significantly reduced cell stiffness. These results reveal that MAPK signalling, in addition to tumour cell proliferation, has a significant role in regulating cell biomechanics.This article has an associated First Person interview with the first author of the paper.


Subject(s)
Actin Cytoskeleton/physiology , Biomechanical Phenomena/physiology , Cell Movement/physiology , MAP Kinase Signaling System/physiology , Melanoma/physiopathology , Anisotropy , Cell Line, Tumor , Cell Plasticity/physiology , Cell Proliferation , Focal Adhesions/physiology , Humans , Micropore Filters , Neoplasm Invasiveness/pathology , Neoplasm Metastasis/pathology , Proto-Oncogene Proteins B-raf/metabolism , Proto-Oncogene Proteins p21(ras)/metabolism
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