Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 20
Filter
1.
Clin Med Insights Oncol ; 18: 11795549241233692, 2024.
Article in English | MEDLINE | ID: mdl-38482163

ABSTRACT

Background: The reported complication rates of neck dissection are not specific patients with papillary thyroid cancer` with metastatic lymph nodes. This study aimed to describe the complication profile of neck dissection and the effect of concurrent lateral neck dissection on complication rates. Methods: This single-center prospective cohort study analyzed the data of 52 patients who underwent a total thyroidectomy and therapeutic lymph node dissection between March 2021 and March 2023. The clinicopathologic characteristics of patients and surgical complications were analyzed. Results: The transient recurrent laryngeal nerve palsy (RLNP) and hypoparathyroidism rates were 55.8% and 51.9%, respectively. The chyle leakage rate was 5.8%. Tracheostomy was performed on 1 patient (1.9%). Patients with transient RLNP had more retrieved lymph nodes than patients without RLNP (5.5 ± 2.7 vs 3.9 ± 1.5, P = .013). The rates of transient RLNP and hypoparathyroidism were higher in the total thyroidectomy with central and lateral neck dissection group than the total thyroidectomy with central neck dissection group (62.2% vs 14.3%, P = .035 and 57.8% vs 14.3%, P = .046). Multivariate analysis showed that the increased number of retrieved lymph nodes in the central compartment and the addition of lateral neck dissection were independent risk factors for transient RLNP, with odds ratio (OR) (95% confidence interval) of 0.72 (0.53-0.98) and 9.42 (1.02-87.34). Conclusion: The rates of transient RLNP and hypoparathyroidism after lymph node dissection in patients with papillary thyroid cancer with metastatic lymph nodes were high, and a greater number of retrieved lymph nodes in the central neck and the addition of lateral neck dissection were predictors for transient RLNP. These data may be used to discuss preoperatively with patients and make surgeons more cautious and meticulous during surgery to minimize complications.

2.
Nano Lett ; 24(4): 1145-1152, 2024 Jan 31.
Article in English | MEDLINE | ID: mdl-38194429

ABSTRACT

We present a novel technique of genetic transformation of bacterial cells mediated by high frequency electromagnetic energy (HF EME). Plasmid DNA, pGLO (5.4 kb), was successfully transformed into Escherichia coli JM109 cells after exposure to 18 GHz irradiation at a power density between 5.6 and 30 kW m-2 for 180 s at temperatures ranging from 30 to 40 °C. Transformed bacteria were identified by the expression of green fluorescent protein (GFP) using confocal scanning microscopy (CLSM) and flow cytometry (FC). Approximately 90.7% of HF EME treated viable E. coli cells exhibited uptake of the pGLO plasmid. The interaction of plasmid DNA with bacteria leading to transformation was confirmed by using cryogenic transmission electron microscopy (cryo-TEM). HF EME-induced plasmid DNA transformation was shown to be unique, highly efficient, and cost-effective. HF EME-induced genetic transformation is performed under physiologically friendly conditions in contrast to existing techniques that generate higher temperatures, leading to altered cellular integrity. This technique allows safe delivery of genetic material into bacterial cells, thus providing excellent prospects for applications in microbiome therapeutics and synthetic biology.


Subject(s)
Escherichia coli , Transformation, Bacterial , Plasmids/genetics , DNA/metabolism , Bacteria/genetics , Electromagnetic Radiation
3.
RSC Adv ; 13(36): 25007-25017, 2023 Aug 21.
Article in English | MEDLINE | ID: mdl-37614787

ABSTRACT

The electronic, magnetic, optical and elastic properties of nanomaterials are governed partially by the crystallite size and crystal defects. Here, the crystalline size of hexagonal La1-xSrxMnO3 (x = 0.3) nanoparticles was determined using various methods. Single-phase La0.7Sr0.3MnO3 nanopowders were produced after 10 h of milling in a commercial high-energy SPEX 8000D shaker mill, and then they were heated at 700 °C and 800 °C to study the effect of calcined temperature on the crystallization of nanoparticles. The modified Scherrer, Williamson-Hall, size-strain, and Halder-Wagner methods were used to determine the crystallite sizes and the elastic properties, such as intrinsic strain, stress, and energy density, from the X-ray diffraction peak broadening analysis. The obtained results were then compared with one another. The difference in crystallite sizes calculated from the different methods was due to the different techniques.

4.
J Synchrotron Radiat ; 30(Pt 4): 780-787, 2023 Jul 01.
Article in English | MEDLINE | ID: mdl-37338043

ABSTRACT

The routes by which foreign objects enter cells is well studied; however, their fate following uptake has not been explored extensively. Following exposure to synchrotron-sourced (SS) terahertz (THz) radiation, reversible membrane permeability has been demonstrated in eukaryotic cells by the uptake of nanospheres; nonetheless, cellular localization of the nanospheres remained unclear. This study utilized silica core-shell gold nanospheres (AuSi NS) of diameter 50 ± 5 nm to investigate the fate of nanospheres inside pheochromocytoma (PC 12) cells following SS THz exposure. Fluorescence microscopy was used to confirm nanosphere internalization following 10 min of SS THz exposure in the range 0.5-20 THz. Transmission electron microscopy followed by scanning transmission electron microscopy energy-dispersive spectroscopic (STEM-EDS) analysis was used to confirm the presence of AuSi NS in the cytoplasm or membrane, as single NS or in clusters (22% and 52%, respectively), with the remainder (26%) sequestered in vacuoles. Cellular uptake of NS in response to SS THz radiation could have suitable applications in a vast number of biomedical applications, regenerative medicine, vaccines, cancer therapy, gene and drug delivery.


Subject(s)
Adrenal Gland Neoplasms , Nanospheres , Pheochromocytoma , Humans , Terahertz Radiation , Nanospheres/chemistry , Synchrotrons
5.
Infect Genet Evol ; 112: 105438, 2023 08.
Article in English | MEDLINE | ID: mdl-37105346

ABSTRACT

Outer inflammatory protein A (OipA), which is encoded by the oipA gene, can induce interleukin-8 secretion in gastric epithelial cells. The functional status of the oipA gene is regulated by the slipped-strand mispairing mechanism based on the CT dinucleotide repeat number in the 5' region. This study aimed to investigate the oipA functional status ("on/off") of Helicobacter pylori (H. pylori) and its association with gastroduodenal diseases in southwestern Vietnam. The cross-sectional study was conducted on 173H. pylori isolates from 173 patients with gastroduodenal diseases. Sanger sequencing was used to determine the functional status of oipA. Multivariable logistic regression analysis was performed to identify the association between oipA status and gastroduodenal diseases. The oipA "on" status accounted for 96% of H. pylori isolates. Twenty-five CT repeat patterns of the oipA 5' signal region were observed, five of which were novel CT repeat patterns. The oipA "on" status was found in 100%, 97.8%, and 86.8% of H. pylori isolates from patients with peptic ulcer, precancerous lesions, and chronic gastritis, respectively (p < 0.01). The oipA "on" status was related to gastric precancerous lesions versus chronic gastritis (adjusted OR = 7.39, 95% CI: 1.35-40.59, p = 0.021) and peptic ulcers versus chronic gastritis (adjusted OR = 12.79, 95% CI: 1.19-1760.32, p = 0.033). Our data show a high prevalence of the oipA "on" status, which was associated with precancerous gastric lesions and peptic ulcers. Moreover, genetic diversity in the number and pattern of CT dinucleotide repeat of oipA among Vietnamese H. pylori strains was identified.


Subject(s)
Gastritis , Helicobacter Infections , Helicobacter pylori , Peptic Ulcer , Humans , Bacterial Outer Membrane Proteins/genetics , Helicobacter pylori/genetics , Helicobacter pylori/metabolism , Cross-Sectional Studies , Vietnam/epidemiology , Peptic Ulcer/pathology , Genetic Variation , Helicobacter Infections/epidemiology , Helicobacter Infections/pathology , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Antigens, Bacterial/genetics
6.
RSC Adv ; 12(52): 33825-33834, 2022 Nov 22.
Article in English | MEDLINE | ID: mdl-36505679

ABSTRACT

In this paper, a novel bimetallic Fe-Cu metal-organic framework combined with 1,3,5-benzenetricarboxylic acid (Fe-Cu-BTC) are synthesized using hydrothermal reaction. The bimetallic Fe-Cu-BTC with high BET (1504 cm3 g-1) and high Langmuir surface area (1831 cm3 g-1) is composited by gold nanoparticles to improve the conductivity and to develop their synergistic effect. A novel bisphenol A (BPA) sensor was prepared by dropcasting Fe-Cu-BTC on glassy carbon electrodes (GCE) followed by AuNPs electrodeposition. The Fe-Cu-BTC framework were characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy studies (TEM), FT-IR, BET measurements and EDX spectra. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were carried out for surveying the electrochemical properties of the sensors and for the quantification of BPA. Two linear ranges of BPA concentrations 0.1-1.0 µM and 1.0-18 µM with 18 nM limit of detection were obtained. The developed sensor was used to measure the concentration of BPA in samples extracted from rain coat with the recovery ranging from 85.70 to 103.23%.

7.
ACS Appl Mater Interfaces ; 14(28): 31933-31941, 2022 Jul 20.
Article in English | MEDLINE | ID: mdl-35802813

ABSTRACT

Gas-fed zero-gap electrolyzers have recently emerged as attractive systems for limiting ohmic losses and costs associated with electrolytes and for optimizing energy efficiencies. Here, we report that using a dendritic Cu oxide (D-CuO) material deposited on a gas diffusion layer as the cathode of a gas-fed zero-gap membrane electrode assembly (MEA) system results in a very selective conversion of CO to ethylene. More specifically, CO reduction yielded ethylene with an FE up to 68% at 100-125 mA·cm-2 with H2 as the only other gaseous product and the electrolysis could be carried out for several hours with good stability. Ethylene was also the major product during CO2 electrolysis (FE = 41%) at 125-150 mA·cm-2, reflecting the high selectivity of D-CuO for ethylene production. Such systems are relevant for tandem CO2 electroreduction processes, allowing energy efficiencies above 30%.

8.
Arch Microbiol ; 204(5): 252, 2022 Apr 12.
Article in English | MEDLINE | ID: mdl-35411478

ABSTRACT

A widely used herbicide for controlling weeds, glyphosate, is causing environmental pollution. It is necessary to remove it from environment using a cost-effective and eco-friendly method. The aims of this study were to isolate glyphosate-degrading bacteria and to optimize their degradative conditions required for bioremediation. Sixteen bacterial strains were isolated through enrichment and one strain, Rhodococcus soli G41, demonstrated a high removal rate of glyphosate than other strains. Response surface methodology was employed to optimize distinct environmental factors on glyphosate degradation of G41 strain. The optimal conditions for the maximum glyphosate degradation were found to have the NH4Cl concentration of 0.663% and glyphosate concentration of 0.115%, resulting in a maximum degradation of 42.7% after 7 days. Bioremediation analysis showed 47.1% and 40% of glyphosate in unsterile soil and sterile soil was removed by G41 strain after 14 days, respectively. The presence of soxB gene in G41 strain indicates that the glyphosate is degraded via the eco-friendly sarcosine pathway. The results indicated that G41 strain has the potential to serve as an in-situ candidate for bioremediation of glyphosate polluted environments.


Subject(s)
Herbicides , Rhodococcus , Biodegradation, Environmental , Glycine/analogs & derivatives , Herbicides/metabolism , Rhodococcus/genetics , Rhodococcus/metabolism , Soil , Soil Microbiology , Glyphosate
9.
J Racial Ethn Health Disparities ; 9(5): 1818-1827, 2022 10.
Article in English | MEDLINE | ID: mdl-34378172

ABSTRACT

Pacific Islander (PI) young adults (age 18 to 30 years) experience elevated rates of hazardous drinking, AUDs, and alcohol-related harms. Yet, we know little about the risk and protective factors that drive, or can prevent, PI young adult hazardous drinking behaviors and AUDs due to a lack of targeted alcohol disparities research. This large qualitative study presents data from 8 focus groups with 69 PIs (51 young adults, 18 informal providers) to explore the major risk factors, protective factors, and negative consequences associated with PI young adult hazardous drinking and AUDs. Findings revealed (1) major risk factors including the presence of significant life stressors that trigger alcohol self-medication, peer/social pressure to drink, permissive drinking norms, and frequent access to alcohol and (2) negative consequences involving physical fights, health and relationship problems, harm to personal reputation, and community harms including driving-under-the-influence and sexual violence. Protective factors against hazardous drinking and AUDs included the cultural norm of protecting the family's reputation by avoiding AUDs, church/religious faith, family responsibilities, and culturally relevant prosocial activities (e.g., sports, dance, choir). Obtaining this in-depth data revealed that an effective culturally grounded AUD prevention intervention for PI young adults-which does not currently exist-should (1) target these identified major risk factors for AUDs, while (2) integrating culturally responsive strategies that incorporate their reported protective factors.


Subject(s)
Alcoholism , Adolescent , Adult , Alcohol Drinking , Ethanol , Humans , Protective Factors , Risk Factors , Young Adult
10.
J Anal Methods Chem ; 2021: 6613154, 2021.
Article in English | MEDLINE | ID: mdl-33708452

ABSTRACT

The present paper reports the fabrication of inverse opal photonic crystals (IOPCs) by using SiO2 spherical particles with a diameter of 300 nm as an opal photonic crystal template and poly(ethylene glycol) diacrylate (PEGDA) as an inverse opal material. Characteristics and fluorescence properties of the fabricated IOPCs were investigated by using the Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), reflection spectroscopy, and fluorescence microscopy. The results clearly showed that the IOPCs were formed comprising of air spheres with a diameter of ∼270 nm. The decrease in size led to a decrease in the average refractive indexes from 1.40 to 1.12, and a remarkable stopband blue shift for the IOPCs was thus achieved. In addition, the obtained results also showed a fluorescence enhancement over 7.7-fold for the Fluor® 488 dye infiltrated onto the IOPCs sample in comparison with onto the control sample.

11.
RSC Adv ; 11(50): 31408-31420, 2021 Sep 21.
Article in English | MEDLINE | ID: mdl-35496859

ABSTRACT

Membrane model systems capable of mimicking live cell membranes were used for the first time in studying the effects arising from electromagnetic fields (EMFs) of 18 GHz where membrane permeability was observed following exposure. A present lack of understanding of the mechanisms that drive such a rapid change in membrane permeabilization as well as any structural or dynamic changes imparted on biomolecules affected by high-frequency electromagnetic irradiation limits the use of 18 GHz EMFs in biomedical applications. A phospholipid, 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) labelled with a fluorescent marker 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-N-(lissamine rhodamine B sulfonyl) (rhodamine-DOPE) was used in constructing the giant unilamellar vesicles (GUVs). After three cycles of exposure, enhanced membrane permeability was observed by the internalisation of hydrophilic silica nanospheres of 23.5 nm and their clusters. All-atom molecular dynamics simulations of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) membranes exposed to high frequency electric fields of different field strengths showed that within the simulation timeframe only extremely high strength fields were able to cause an increase in the interfacial water dynamics characterized by water dipole realignments. However, a lower strength, high frequency EMF induced changes of the water hydrogen bond network, which may contribute to the mechanisms that facilitate membrane permeabilization in a longer timeframe.

12.
RSC Adv ; 11(36): 22317-22326, 2021 Jun 21.
Article in English | MEDLINE | ID: mdl-35480800

ABSTRACT

Magnetically separable core/shell Fe3O4/ZnO heteronanostructures (MSCSFZ) were synthesized by a facile approach, and their application for enhanced solar photodegradation of RhB was studied. The formation mechanism of MSCSFZ was proposed, in which Fe3O4 nanoparticles served as a template for supporting and anchoring the ZnO crystal layer as the shells. The morphology of MSCSFZ can be varied from spherical to rice seed-like structures, and the bandgap was able to be narrowed down to 2.78 eV by controlling the core-shell ratios. As a result, the MSCSFZ exhibited excellent visible-light photocatalytic activity for degradation of rhodamine B (RhB) in aqueous solution as compared to the controlled ZnO nanoparticles. Moreover, MSCSFZ could be easily detached from RhB solution and maintained its performance after 4 cycles of usage. This work provides new insights for the design of high-efficient core/shell recyclable photocatalysts with visible light photocatalytic performance.

13.
Adv Mater ; 32(52): e2005679, 2020 Dec.
Article in English | MEDLINE | ID: mdl-33179362

ABSTRACT

It is commonly accepted that nanoparticles (NPs) can kill bacteria; however, the mechanism of antimicrobial action remains obscure for large NPs that cannot translocate the bacterial cell wall. It is demonstrated that the increase in membrane tension caused by the adsorption of NPs is responsible for mechanical deformation, leading to cell rupture and death. A biophysical model of the NP-membrane interactions is presented which suggests that adsorbed NPs cause membrane stretching and squeezing. This general phenomenon is demonstrated experimentally using both model membranes and Pseudomonas aeruginosa and Staphylococcus aureus, representing Gram-positive and Gram-negative bacteria. Hydrophilic and hydrophobic quasi-spherical and star-shaped gold (Au)NPs are synthesized to explore the antibacterial mechanism of non-translocating AuNPs. Direct observation of nanoparticle-induced membrane tension and squeezing is demonstrated using a custom-designed microfluidic device, which relieves contraction of the model membrane surface area and eventual lipid bilayer collapse. Quasi-spherical nanoparticles exhibit a greater bactericidal action due to a higher interactive affinity, resulting in greater membrane stretching and rupturing, corroborating the theoretical model. Electron microscopy techniques are used to characterize the NP-bacterial-membrane interactions. This combination of experimental and theoretical results confirm the proposed mechanism of membrane-tension-induced (mechanical) killing of bacterial cells by non-translocating NPs.


Subject(s)
Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Cell Membrane/drug effects , Gold/chemistry , Gold/pharmacology , Mechanical Phenomena/drug effects , Metal Nanoparticles , Biomechanical Phenomena/drug effects , Cell Membrane/metabolism , Pseudomonas aeruginosa/cytology , Pseudomonas aeruginosa/drug effects , Staphylococcus aureus/cytology , Staphylococcus aureus/drug effects
14.
Chem Biol Interact ; 317: 108930, 2020 Feb 01.
Article in English | MEDLINE | ID: mdl-31866335

ABSTRACT

Ferroptosis is recently identified form of regulated cell death which differs from previously identified cell death in a way that it is driven by iron-dependent lipid peroxide accumulation. Morphologically, cell volume shrinkage and increased mitochondrial membrane density are main features which characterize this form of cell death. Molecular mechanism of ferroptosis induction involved suppression of the phospholipid glutathione peroxidase 4 (GPX4) and further intracellular accumulation of lipid reactive oxygen species (ROS), a process in which iron is involved; either via inhibition of system Xc- (cystine/glutamate antiporter) or direct inhibition of GPX4. Several other pathways like RAS/MAPK and NRF2 are found to be involved in ferroptosis regulation. However, the precise mechanism of ferroptosis induction is not revealed till date. Like other regulated cell deaths, ferroptosis plays important role in tumor suppression and progression as revealed by several scientific reports. This review summarizes basic information about discovery of this novel cell death mechanism including molecular mechanism of its induction and further explains the roles of ferroptosis in human cancers.


Subject(s)
Antineoplastic Agents/pharmacology , Ferroptosis/physiology , Neoplasms/metabolism , Gene Expression Regulation, Neoplastic/drug effects , Humans , Neoplasms/drug therapy
15.
Int J Nanomedicine ; 13: 8429-8442, 2018.
Article in English | MEDLINE | ID: mdl-30587969

ABSTRACT

BACKGROUND: Effects of man-made electromagnetic fields (EMF) on living organisms potentially include transient and permanent changes in cell behaviour, physiology and morphology. At present, these EMF-induced effects are poorly defined, yet their understanding may provide important insights into consequences of uncontrolled (e.g., environmental) as well as intentional (e.g., therapeutic or diagnostic) exposure of biota to EMFs. In this work, for the first time, we study mechanisms by which a high frequency (18 GHz) EMF radiation affects the physiology of membrane transport in pheochromocytoma PC 12, a convenient model system for neurotoxicological and membrane transport studies. METHODS AND RESULTS: Suspensions of the PC 12 cells were subjected to three consecutive cycles of 30s EMF treatment with a specific absorption rate (SAR) of 1.17 kW kg-1, with cells cooled between exposures to reduce bulk dielectric heating. The EMF exposure resulted in a transient increase in membrane permeability for 9 min in up to 90 % of the treated cells, as demonstrated by rapid internalisation of silica nanospheres (diameter d ≈ 23.5 nm) and their clusters (d ≈ 63 nm). In contrast, the PC 12 cells that received an equivalent bulk heat treatment behaved similar to the untreated controls, showing lack to minimal nanosphere uptake of approximately 1-2 %. Morphology and growth of the EMF treated cells were not altered, indicating that the PC 12 cells were able to remain viable after the EMF exposure. The metabolic activity of EMF treated PC 12 cells was similar to that of the heat treated and control samples, with no difference in the total protein concentration and lactate dehydrogenase (LDH) release between these groups. CONCLUSION: These results provide new insights into the mechanisms of EMF-induced biological activity in mammalian cells, suggesting a possible use of EMFs to facilitate efficient transport of biomolecules, dyes and tracers, and genetic material across cell membrane in drug delivery and gene therapy, where permanent permeabilisation or cell death is undesirable.


Subject(s)
Adrenal Gland Neoplasms/metabolism , Electromagnetic Fields , Nanospheres/chemistry , Pheochromocytoma/metabolism , Adrenal Gland Neoplasms/pathology , Adrenal Gland Neoplasms/ultrastructure , Animals , Biological Transport , Cell Membrane Permeability , Nanospheres/ultrastructure , PC12 Cells , Pheochromocytoma/pathology , Pheochromocytoma/ultrastructure , Rats , Silicon Dioxide/chemistry
16.
Sci Rep ; 7(1): 10798, 2017 09 07.
Article in English | MEDLINE | ID: mdl-28883444

ABSTRACT

The effect of red blood cells (RBC) exposed to an 18 GHz electromagnetic field (EMF) was studied. The results of this study demonstrated for the first time that exposure of RBCs to 18 GHz EMF has the capacity to induce nanospheres uptake in RBCs. The uptake of nanospheres (loading efficiency 96% and 46% for 23.5 and 46.3 nm nanospheres respectively), their presence and locality were confirmed using three independent techniques, namely scanning electron microscopy, confocal laser scanning microscopy and transmission electron microscopy. It appeared that 23.5 nm nanospheres were translocated through the membrane into the cytosol, while the 46.3 nm-nanospheres were mostly translocated through the phospholipid-cholesterol bilayer, with only some of these nanospheres passing the 2D cytoskeleton network. The nanospheres uptake increased by up to 12% with increasing temperature from 33 to 37 °C. The TEM analysis revealed that the nanospheres were engulfed by the cell membrane itself, and then translocated into the cytosol. It is believed that EMF-induced rotating water dipoles caused disturbance of the membrane, initiating its deformation and result in an enhanced degree of membrane trafficking via a quasi-exocytosis process.


Subject(s)
Electromagnetic Fields , Erythrocytes/radiation effects , Microwaves , Animals , Erythrocytes/cytology , Erythrocytes/ultrastructure , Microscopy, Electron, Scanning , Rabbits
17.
PLoS One ; 11(7): e0158135, 2016.
Article in English | MEDLINE | ID: mdl-27391488

ABSTRACT

The mechanisms by which various biological effects are triggered by exposure to an electromagnetic field are not fully understood and have been the subject of debate. Here, the effects of exposing typical representatives of the major microbial taxa to an 18 GHz microwave electromagnetic field (EMF)were studied. It appeared that the EMF exposure induced cell permeabilisation in all of the bacteria and yeast studied, while the cells remained viable (94% throughout the exposure), independent of the differences in cell membrane fatty acid and phospholipid composition. The resulting cell permeabilisation was confirmed by detection of the uptake of propidium iodine and 23 nm fluorescent silica nanospheres using transmission electron microscopy (TEM) and confocal laser scanning microscopy (CLSM). Upon EMF exposure, the bacterial cell membranes are believed to become permeable through quasi-endocytosis processes. The dosimetry analysis revealed that the EMF threshold level required to induce the uptake of the large (46 nm) nanopsheres was between three and six EMF doses, with a specific absorption rate (SAR) of 3 kW/kg and 5 kW/kg per exposure, respectively, depending on the bacterial taxa being studied. It is suggested that the taxonomic affiliation and lipid composition (e.g. the presence of phosphatidyl-glycerol and/or pentadecanoic fatty acid) may affect the extent of uptake of the large nanospheres (46 nm). Multiple 18 GHz EMF exposures over a one-hour period induced periodic anomalous increases in the cell growth behavior of two Staphylococcus aureus strains, namely ATCC 25923 and CIP 65.8T.


Subject(s)
Electromagnetic Fields , Saccharomyces cerevisiae/radiation effects , Staphylococcus aureus/radiation effects , Cell Membrane/metabolism , Fatty Acids/chemistry , Lipids/chemistry , Microscopy, Confocal , Microscopy, Electron, Transmission , Microwaves , Nanospheres/chemistry , Permeability , Propidium/chemistry , Radiation Dosage
19.
Sci Rep ; 5: 10980, 2015 Jun 16.
Article in English | MEDLINE | ID: mdl-26077933

ABSTRACT

The effect of electromagnetic field (EMF) exposures at the microwave (MW) frequency of 18 GHz, on four cocci, Planococcus maritimus KMM 3738, Staphylococcus aureus CIP 65.8(T), S. aureus ATCC 25923 and S. epidermidis ATCC 14990(T), was investigated. We demonstrate that exposing the bacteria to an EMF induced permeability in the bacterial membranes of all strains studied, as confirmed directly by transmission electron microscopy (TEM), and indirectly via the propidium iodide assay and the uptake of silica nanospheres. The cells remained permeable for at least nine minutes after EMF exposure. It was shown that all strains internalized 23.5 nm nanospheres, whereas the internalization of the 46.3 nm nanospheres differed amongst the bacterial strains (S. epidermidis ATCC 14990(T) ~ 0%; Staphylococcus aureus CIP 65.8(T) S. aureus ATCC 25923, ~40%; Planococcus maritimus KMM 3738, ~ 80%). Cell viability experiments indicated that up to 84% of the cells exposed to the EMF remained viable. The morphology of the bacterial cells was not altered, as inferred from the scanning electron micrographs, however traces of leaked cytosolic fluids from the EMF exposed cells could be detected. EMF-induced permeabilization may represent an innovative, alternative cell permeability technique for applications in biomedical engineering, cell drug delivery and gene therapy.


Subject(s)
Electromagnetic Radiation , Planococcus Bacteria/radiation effects , Staphylococcus aureus/radiation effects , Staphylococcus epidermidis/radiation effects , Biological Transport , Cell Membrane Permeability/radiation effects , Electromagnetic Fields , Microbial Viability/radiation effects , Microscopy, Electron, Transmission , Nanospheres/chemistry , Nanospheres/metabolism , Nanospheres/ultrastructure , Particle Size , Planococcus Bacteria/metabolism , Planococcus Bacteria/ultrastructure , Propidium , Silicon Dioxide/chemistry , Silicon Dioxide/metabolism , Staphylococcus aureus/metabolism , Staphylococcus aureus/ultrastructure , Staphylococcus epidermidis/metabolism , Staphylococcus epidermidis/ultrastructure
20.
Article in Vietnamese | WPRIM (Western Pacific) | ID: wpr-5789

ABSTRACT

In early 2004, following an epidemic of avian influenza A/H5N1 in human, an outbreak of influenza A/H3 occurred in 5 communes at Hung Yen province with 887 cases and no deaths. This outbreak developed quickly but only in medium geographical range (inter-commune). Most cases are of school-age (from 5 to 19 years old) which comprise over 85% of the total number and focus mainly in primary and secondary schools. Owing to discovered early the outbreak, consisted of determinate the reasons and response to outbreak quickly and strongly and applied routinely to prevention the spread through the respiratory, and it also the good lesson to the prevention of outbreak


Subject(s)
Disease Outbreaks , Influenza, Human , Epidemiology
SELECTION OF CITATIONS
SEARCH DETAIL
...