Decrease In Membrane Permeability Research Articles

Whole-Genome Sequencing of Russian Neisseria Gonorrhoeae Isolates Related to ST 1407 Genogroup

The whole-genome sequencing data of three N. gonorrhoeae strains isolated in the Russian Federation in 2015 are presented. According to the NG-MAST protocol, these strains are related to the globally spread ST 1407 genogroup. The analysis of their resistomes showed the absence of ermA/B/C/F genes and the presence of wild-type alleles of rpsE, rrs, rrl, rplD, rplV, macAB, and mefA genes, and these patterns explain the susceptibility of the sequenced strains to aminocyclitols (spectinomycin) and macrolides (azithromycin). Conjugative resistance determinants (blaTEM, tetM) were absent in the genomes, and the penC/ pilQ, parE, and norM alleles were shown to be wild-type, whereas single or multiple nucleotide substitutions were identified in the genes encoding targets for -lactams (ponA, penA), tetracyclines (rpsJ), and fluoroquinolones (gyrA, parC). The additional mutations were found in porB gene and the promoter of mtrR gene, which nonspecifically reduced the susceptibility to antimicrobials due to the membrane permeability decrease and efflux pump overexpression. The diversity of mutations observed in the analyzed genomes prompted a revision of the phylogenetic relationships between the strains by comparing more than 790 groups of housekeeping genes. A high homology between the N. gonorrhoeae ST 1407 and N. gonorrhoeae ST 12556 genomes was confirmed; the latter had probably diverged from a common ancestor as a result of single mutation events. On the other hand, N. gonorrhoeae ST 12450 was an example of phenotypic convergence which appeared in the emergence of new drug resistance determinants that partially coincide with those of the ST 1407 genogroup.

Полногеномное секвенирование российских штаммов Neisseria Gonorrhoeae, отнесенных к геногруппе ST 1407

The whole-genome sequencing data of three N. gonorrhoeae strains isolated in the Russian Federation in 2015 are presented. According to the NG-MAST protocol, these strains are related to the globally spread ST 1407 genogroup. The analysis of their resistomes showed the absence of ermA/B/C/F genes and the presence of wild-type alleles of rpsE, rrs, rrl, rplD, rplV, macAB, and mefA genes, and these patterns explain the susceptibility of the sequenced strains to aminocyclitols (spectinomycin) and macrolides (azithromycin). Conjugative resistance determinants (blaTEM, tetM) were absent in the genomes, and the penC/ pilQ, parE, and norM alleles were shown to be wild-type, whereas single or multiple nucleotide substitutions were identified in the genes encoding targets for β-lactams (ponA, penA), tetracyclines (rpsJ), and fluoroquinolones (gyrA, parC). The additional mutations were found in porB gene and the promoter of mtrR gene, which nonspecifically reduced the susceptibility to antimicrobials due to the membrane permeability decrease and efflux pump overexpression. The diversity of mutations observed in the analyzed genomes prompted a revision of the phylogenetic relationships between the strains by comparing more than 790 groups of housekeeping genes. A high homology between the N. gonorrhoeae ST 1407 and N. gonorrhoeae ST 12556 genomes was confirmed; the latter had probably diverged from a common ancestor as a result of single mutation events. On the other hand, N. gonorrhoeae ST 12450 was an example of phenotypic convergence which appeared in the emergence of new drug resistance determinants that partially coincide with those of the ST 1407 genogroup.

Facile and efficient in situ synthesis of silver nanoparticles on diverse filtration membrane surfaces for antimicrobial performance

Membrane biofouling remains a major limiting factor for the membrane-based water purification technology. The development of antibacterial membrane surfaces is very important for membrane biofouling mitigation. In this study, we developed a one-pot method of synthesizing silver nanoparticles (Ag NPs) and immobilizing them onto membranes via simply soaking the membranes in a mixture solution of silver nitrate, poly (ethylene glycol) methyl ether thiol (mPEG-SH) and dopamine. Results illustrate that mPEG-SH works as a ligand to slow down the reduction process of silver ions by dopamine for the synthesis of Ag NPs in a controllable manner and also the prevention of Ag NPs aggregation in solution. Moreover, the Ag NPs could be in situ immobilized onto polysulfone ultrafiltration membrane, glass fiber membrane and stainless steel, regardless of their surface properties, but the size of Ag NPs was affected by the substrates. In addition, the Ag NPs immobilization on the polysulfone ultrafiltration membranes increased the bovine serum albumin rejection rate of membrane by 16%, but decreased membrane permeability by 14% compared to that of the pristine membranes. The Ag NPs containing membranes exhibited outstanding antibacterial properties with more than 90% antibacterial efficiency against both Gram-negative bacteria Escherichia coli and Gram-positive bacteria Staphylococcus aureus. During the filtration test, the silver release from the Ag NPs containing polysulfone ultrafiltration membranes was very slow and the total accumulation of silver ions released from the membranes was only 7% of its initial Ag NPs loading after 24 h filtration operation. The silver ion concentration in the permeate water was 0.35 ± 0.16 ppb, far below the maximal contaminant limit of silver ions in drinking water with no risk for the application of Ag NPs incorporated membranes to treat water. Our work provides a facile and universal approach of synthetizing and simultaneously immobilizing Ag NPs onto diverse membranes for antibacterial properties.

Mode of action of nanoparticles against insects.

The employment of nanoparticles obtained through various synthesis routes as novel pesticides recently attracted high research attention. An impressive number of studies have been conducted to test their toxic potential against a wide number of arthropod pests and vectors, with major emphasis on mosquitoes and ticks. However, precise information on the mechanisms of action of nanoparticles against insects and mites are limited, with the noteworthy exception of silica, alumina, silver, and graphene oxide nanoparticles on insects, while no information is available for mites. Here, I summarize current knowledge about the mechanisms of action of nanoparticles against insects. Both silver and graphene oxide nanoparticles have a significant impact on insect antioxidant and detoxifying enzymes, leading to oxidative stress and cell death. Ag nanoparticles also reduced acetylcholinesterase activity, while polystyrene nanoparticles inhibited CYP450 isoenzymes. Au nanoparticles can act as trypsin inhibitors and disrupt development and reproduction. Metal nanoparticles can bind to S and P in proteins and nucleic acids, respectively, leading to a decrease in membrane permeability, therefore to organelle and enzyme denaturation, followed by cell death. Besides, Ag nanoparticles up- and downregulate key insect genes, reducing protein synthesis and gonadotrophin release, leading to developmental damages and reproductive failure. The toxicity of SiO2 and Al2O3 nanoparticles is due to their binding to the insect cuticle, followed by physico-sorption of waxes and lipids, leading to insect dehydration. In the final section, insect nanotoxicology research trends are critically discussed, outlining major challenges to predict the ecotoxicological consequences arising from the real-world use of nanoparticles as pesticides.

Membrane Stabilizing Effects of Calcium in Salt-induced Hypertensive Pregnancy

Though Calcium is involved in the mechanisms of increase contractility, it has been shown that at high concentration, calcium ions may cause membrane stabilization in which case the smooth muscle responsiveness decreases. Theoretically, a decrease in membrane permeability to calcium ions caused by increased extracellular calcium concentration stabilizes membranes. Apparently, administration of high level of calcium ion may become useful either by way of preventing or diminishing pregnancy induced hypertension (preeclampsia). The goal of this study was to examine the effect of calcium ion on the sensitivity of blood vessels during pregnancy, especially in salt induced hypertensive pregnancy. The isolated aorta of Forty adult Sprague Dawley rats [four groups of ten rats each; with Group 1=non pregnant fed with normal rat chow, Group 2=normal rat chow + 5% CaCl2 prior to and during 6 weeks feeding on 1.6% NaCl, Group 3=normal rat chow + 8% NaCl for 6 weeks, and Group 4=pregnant rats (350-380) fed on normal rat chow] was cut into 2 mm ring segments and each segment was suspended between two L-shaped holders. The lower holder was fixed to the base of 20 ml organ baths containing physiological salt solution, while the upper holder was connected to isometric transducer coupled to Ugo Bassile recorder. The presence of functional endothelium was ascertained before the start of the experiment by the observation of at least, 42% relaxation to 10-7 M acetylcholine in blood vessels contracted with 10-7 M noradrenaline. Concentration response tests to phenylephrine, KCl, and CaCl2 were done and result compared. Results show that the maximum contraction to phenylephrine of rings from pregnant rats fed on calcium chloride diets were insignificantly different from those of rats fed only with sodium chloride diet. Their sensitivities were however significantly (p<0.05) different. This observation suggests that the effect of Ca2+ feeding may be limited to the sensitivity, rather than the maximum contraction. Prior calcium feeding along with simultaneous high salt (sodium chloride) intake appears to interfere with the enhancement of vascular contractility associated with high salt intake. Ca2+ would therefore be relevant in the prevention and treatment of salt-induced hypertension in pregnancy.

Mixed-matrix membranes containing an azine-linked covalent organic framework: Influence of the polymeric matrix on post-combustion CO2-capture

The use of an azine-linked covalent organic framework (ACOF-1) as filler in mixed-matrix membranes (MMMs) has been studied for the separation of CO2 from N2. To better understand the mechanisms that govern separation in complex composites, MMMs were prepared with different loadings of ACOF-1 and three different polymers as continuous phase: low flux-mid selectivity Matrimid®, mid flux-high selectivity Polyactive™ and high flux-low selectivity 6FDA:DAM. The homogeneous distribution of ACOF-1 together with the good adhesion between the ACOF-1 particles and the polymer matrices were confirmed by scanning electron microscopy. In mixed-gas CO2/N2 separation a clear influence of the polymer used was observed on the performance of the composite membranes. While for Matrimid® and 6FDA:DAM an overall enhancement of the polymer's separation properties could be achieved, in case of Polyactive™ penetration of the more flexible polymer into the COF porosity resulted in a decreased membrane permeability. The best improvement was obtained for Matrimid®-based MMMs, for which a selectivity increase from 29 to 35, together with an enhancement in permeability from 9.5 to 17.7 Barrer for 16wt% COF loading, was observed. Our results demonstrate that the combination of the filler-polymeric matrix pair chosen is crucial. For a given filler the polymer performance improvement strongly depends on the polymeric matrix selected, where a good match between the discontinuous and continuous phase, both in the terms of compatibility and gas separation properties, is necessary to optimize membrane performance.

Polydimethylsiloxane Membranes Containing Multi-walled Carbon Nanotubes for Gas Separation

Polydimethylsiloxane (PDMS) membranes with different concentrations of multi-walled carbon nanotubes were prepared in order to evaluate their gas separation performances. Mixed matrix membranes were characterized by scanning electron microscopy, thermogravimetric analysis, Fourier transformed infrared, positron annihilation lifetime and Raman spectroscopies and X-ray diffraction. The permeabilities to CO2, CH4, N2 and O2 were determined. No phase separation was noticed. For carbon nanotubes content of 1 wt%, it was shown a decrease in membrane permeability with slight increase in ideal selectivity, compared to pure PDMS. However, the increase in the filler load up to 6.7 wt% increased the free volume average size of the membranes, improving the contribution of the diffusion to the transport and decreasing ideal selectivities of CO2/CH4, CO2/N2 and O2/N2.

Effect of NaHS on ATP-induced P2X receptor expression in rat microglia

To observed the effect of sodium hydrosulphide (NaHS), a donor of H2S on the cell viability,the membrane permeability and the expression of P2X7 receptor induced by adenosine triphosphate(ATP) in rat microglia. Rat microglia in logarithmic growth phase was randomly divided into 4 groups. In control group, the cells were cultured without ATP treatment. In ATP group, the cells were treatment with ATP after cultured for 24 hours. In NaHS+ATP group, the cells were incubated with NaHS for 30 min before ATP, and NaHS always existed in the reaction system. In KN-62+ATP group, the cells were pretreated with KN-62 for 30 min, the others were as the same as NaHS+ATP group. The cell viability was detected by MTT. Fluorescent dyes YO-PRO-1 was used to observe the membrane permeability. The expression of P2X7 receptor was examined by immunofluorescence staining. ① Compared with control group, the cell viability dropped after treatment with ATP (1、3、5、10 mmol/L) for 3 hours. When pre-incubation with NaHS(200 μmol/L), the cell viability was apparently higher than that of ATP alone group(P<0.01), while 400 μmol/L had no further beneficial.②The YO-PRO-1 fluorescence intensity was obviously elevated by ATP in rat microglia, but this effect was counteracted by NaHS pretreatment (P<0.01). ③ The expression of P2X7 receptor protein was significantly increased after ATP(3 mmol/L) for 3 h. While the expression upregulation of P2X7 receptor protein induced by ATP was significantly counteracted by pretreating with NaHS(200 μmol/L) (P<0.01). NaHS could reduce the expression of P2X7 receptor, decrease membrane permeability, and increase the cell viability in rat microglia injured by ATP. So the cytoprotection of hydrogen sulfide may be related to the expression and function of P2X7 receptor.

Determination of Permeability Coefficients of Polymersomal Membranes for Hydrophilic Molecules.

Polymer vesicles, so-called polymersomes, can be applied as carrier-systems and universal reaction compartments, due to the possibility to encapsulate guest molecules. Compared to common lipid vesicles, polymersomes show an increased stability and decreased membrane permeability. Control of the mass transport across the membrane is necessary for any application, requiring the precise knowledge of the permeability. So far, data on permeability coefficients of polymersomal membranes are scarce because commonly applied release assays are confronted with the challenge of high detection limits and alternative methods developed so far are either restricted to the use of a certain permeating molecule or rely on the use of nuclear magnetic resonance measurements. In contrast, an influx assay that is broadly applicable to hydrophilic molecules and does not involve specialized equipment was developed in this work, which is based on the passive diffusion of compounds into initially empty vesicles. The method is valid for hydrophilic molecules that show no membrane retention and, thus, do not accumulate within the membrane. Using this method, the permeability of polymersomes made of poly(2-methyloxazoline)15-poly(dimethylsiloxane)68-poly(2-methyloxazoline)15 for seven model compounds was investigated under varying conditions. Permeability coefficients as low as 1.9 × 10-14 cm s-1 could be measured.

Silicon alleviates salt and drought stress of Glycyrrhiza uralensis seedling by altering antioxidant metabolism and osmotic adjustment.

This study was conducted to determine effect and mechanism of exogenous silicon (Si) on salt and drought tolerance of Glycyrrhiza uralensis seedling by focusing on the pathways of antioxidant defense and osmotic adjustment. Seedling growth, lipid peroxidation, antioxidant metabolism, osmolytes concentration and Si content of G. uralensis seedlings were analyzed under control, salt and drought stress [100mM NaCl with 0, 10 and 20% of PEG-6000 (Polyethylene glycol-6000)] with or without 1mM Si. Si addition markedly affected the G. uralensis growth in a combined dose of NaCl and PEG dependent manner. In brief, Si addition improved germination rate, germination index, seedling vitality index and biomass under control and NaCl; Si also increased radicle length under control, NaCl and NaCl-10% PEG, decreased radicle length, seedling vitality index and germination parameters under NaCl-20% PEG. The salt and drought stress-induced-oxidative stress was modulated by Si application. Generally, Si application increased catalase (CAT) activity under control and NaCl-10% PEG, ascorbate peroxidase (APX) activity under all treatments and glutathione (GSH) content under salt combined drought stress as compared with non-Si treatments, which resisted to the increase of superoxide radicals and hydrogen peroxide caused by salt and drought stress and further decreased membrane permeability and malondialdehyde (MDA) concentration. Si application also increased proline concentration under NaCl and NaCl-20% PEG, but decreased it under NaCl-10% PEG, indicating proline play an important role in G. uralensis seedling response to osmotic stress. In conclusion, Si could ameliorate adverse effects of salt and drought stress on G. uralensis likely by reducing oxidative stress and osmotic stress, and the oxidative stress was regulated through enhancing of antioxidants (mainly CAT, APX and GSH) and osmotic stress was regulated by proline.

Application of powdered activated carbon (PAC) for membrane fouling control in a pilot-scale MBR system.

Membrane fouling is considered to be the most serious drawback in wastewater treatment when using membrane bioreactors (MBRs), leading to membrane permeability decrease and efficiency deterioration. This work aims to develop an integrated methodology for membrane fouling control, using powdered activated carbon (PAC), which will enhance the adsorption of soluble microbial products (SMP) and improve membrane filterability, by altering the mixed liquor's characteristics. Reversible fouling was assessed in terms of sludge filterability measurements, according to the standard time-to-filter (TTF) method, while irreversible fouling was assessed in terms of SMP removal. Results showed that the addition of PAC at the concentration of 3 g/L in the mixed liquor reduced SMP concentration and enhanced substantially the sludge filterability. Furthermore, the TTFPAC/TTFno PAC ratios were lower, than the corresponding SMPPAC./SMPno PAC ratios, indicating that the batch-mode, short-term addition of PAC promotes the reversible, rather than the irreversible fouling mitigation.

Dynamical Model of Drug Accumulation in Bacteria: Sensitivity Analysis and Experimentally Testable Predictions.

We present a dynamical model of drug accumulation in bacteria. The model captures key features in experimental time courses on ofloxacin accumulation: initial uptake; two-phase response; and long-term acclimation. In combination with experimental data, the model provides estimates of import and export rates in each phase, the time of entry into the second phase, and the decrease of internal drug during acclimation. Global sensitivity analysis, local sensitivity analysis, and Bayesian sensitivity analysis of the model provide information about the robustness of these estimates, and about the relative importance of different parameters in determining the features of the accumulation time courses in three different bacterial species: Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. The results lead to experimentally testable predictions of the effects of membrane permeability, drug efflux and trapping (e.g., by DNA binding) on drug accumulation. A key prediction is that a sudden increase in ofloxacin accumulation in both E. coli and S. aureus is accompanied by a decrease in membrane permeability.

Integrating highly quantitative proteomics and genome-scale metabolic modeling to study pH adaptation in the human pathogen Enterococcus faecalis.

Genome-scale metabolic models represent the entirety of metabolic reactions of an organism based on the annotation of the respective genome. These models commonly allow all reactions to proceed concurrently, disregarding the fact that at no point all proteins will be present in a cell. The metabolic reaction space can be constrained to a more physiological state using experimentally obtained information on enzyme abundances. However, high-quality, genome-wide protein measurements have been challenging and typically transcript abundances have been used as a surrogate for protein measurements. With recent developments in mass spectrometry-based proteomics, exemplified by SWATH-MS, the acquisition of highly quantitative proteome-wide data at reasonable throughput has come within reach. Here we present methodology to integrate such proteome-wide data into genome-scale models. We applied this methodology to study cellular changes in Enterococcus faecalis during adaptation to low pH. Our results indicate reduced proton production in the central metabolism and decreased membrane permeability for protons due to different membrane composition. We conclude that proteomic data constrain genome-scale models to a physiological state and, in return, genome-scale models are useful tools to contextualize proteomic data.

Development and application of a procedure for evaluating the long-term integrity of membranes for the anaerobic fluidized membrane bioreactor (AFMBR).

A bench-scale short-term test, developed to predict the long-term integrity of membranes with potential for use in anaerobic fluidized-bed membrane bioreactors, was used to evaluate several commercial hollow-fiber membranes. It was found that membrane performance varied widely, some membranes failing much more rapidly than others. Also found was that larger sizes of the fluidized media, in this case granular activated carbon (GAC), severely affected membrane structural integrity more than did smaller sizes, as did the method used for membrane attachment. Within the limits studied, the GAC packing ratio had only a minor impact. A decrease in membrane permeability that sometimes resulted during the testing and was caused by the deposition of fine GAC particles could be eliminated without membrane damage through simultaneous chemical cleaning and sonication. This new testing procedure should be useful for selecting membranes and reactor operating conditions to better ensure long-term operating performance of anaerobic fluidized-bed membrane bioreactors.

Effect of humidity and flue gas impurities on CO2 permeation of a polymer of intrinsic microporosity for post-combustion capture

The impact of humidity and flue gas impurities on PIM-1 membrane performance for post combustion capture, i.e. CO2 permeability and CO2/N2 selectivity, is investigated in this study. The presence of humidity in the feed stream induces a decrease in the permeability coefficients of both CO2 and N2, from 7010 Barrer (dry state) to 4135 Barrer (%RH=50%) and 360 Barrer (dry state) to 250 Barrer (%RH=50%) respectively. PIM-1 shows also a high water permeability (58800 Barrer) which increases with the relative humidity of the feed. The interaction with flue gas contaminants (NOx, SOx, Water) leads to a dramatic decrease of the membrane performance even after short exposure and FTIR analysis confirmed modifications of the chemical structure of PIM-1 caused by the acid environment. These results indicate that test with flue gases have to be considered for all novel materials proposed for carbon capture applications since the decrease in membrane permeability in presence of water and other impurities has to be taken into account during the design of the separation process.

Solid State NMR Investigations of Lipid Bilayers in Interaction with Amphiphilic Triblock Copolymers

Pluronics are triblock copolymers consisting of hydrophilic poly(ethylene oxide) end blocks and a hydrophobic poly(propylene oxide) middle block. They are widely used in pharmacological industry. Depending on the lengths of the different blocks, Pluronics can influence membrane properties in a variety of ways, e.g., increase or decrease membrane permeability. This variable influence could be explained by different ways of incorporation1, i.e., spanning the membrane or just penetrating it as hairpin.Our work focuses on Pluronics as well as its variations, obtained by replacing the PEO-blocks by the more bulky poly(glycerol monomethacrylate) (PGMA) blocks. The latter have a higher propensity to act as hydrogen bond donor and acceptor, potentially increasing the interaction with the lipid head group.2 Using solid state MAS NMR, we investigate structure and dynamics of model membranes consisting of phosphatidylcholines with variable bilayer thickness and saturation, in mixture with copolymers of variable block length. 1H-1H Nuclear Overhauser Enhancement (2D-NOESY) experiments were applied to confirm the insertion of the copolymer into the bilayer. Motionally averaged dipolar couplings yield information on molecular dynamics.For the lipids, heteronuclear 13C-1H dipolar coupling constants were determined by the R-PDLF experiment, obtaining similar results for all samples and the pure lipids, confirming a weak influence of the polymers on lipid dynamics. Homonuclear 1H-1H residual couplings were measured with the Back-to-Back (BaBa) double-quantum recoupling pulse sequence3, which is suitable for measuring the very small coupling constants of the polymers. In this way, we were able to quantify the relative amount of inserted vs. non-inserted polymer and conclude on its conformation.[1] H. Rabbel et al., Macromolecules, 48, 4724, 2015.[2] C. Schwieger et al., Matter,10, 6147, 2014.[3] K. Saalwachter et al., J. Magn. Reson., 212, 204, 2011.

Helicobacter pylori and Antibiotic Resistance, A Continuing and Intractable Problem.

Helicobacter pylori, a human pathogen with a high global prevalence, is the causative pathogen for multiple gastrointestinal diseases, especially chronic gastritis, peptic ulcers, gastric mucosa-associated lymphoid tissue lymphoma, and gastric malignancies. Antibiotic therapies remain the mainstay for H. pylori eradication; however, this strategy is hampered by the emergence and spread of H. pylori antibiotic resistance. Exploring the mechanistic basis of this resistance is becoming one of the major research questions in contemporary biomedical research, as such knowledge could be exploited to devise novel rational avenues for counteracting the existing resistance and devising strategies to avoid the development of a novel anti-H. pylori medication. Encouragingly, important progress in this field has been made recently. Here, we attempt to review the current state and progress with respect to the molecular mechanism of antibiotic resistance for H. pylori. A picture is emerging in which mutations of various genes in H. pylori, resulting in decreased membrane permeability, altered oxidation-reduction potential, and a more efficient efflux pump system. The increased knowledge on these mechanisms produces hope that antibiotic resistance in H. pylori can ultimately be countered.

Mapping Cd2+-induced membrane permeability changes of single live cells by means of scanning electrochemical microscopy

Scanning Electrochemical Microscopy (SECM) is a powerful, non-invasive, analytical methodology that can be used to investigate live cell membrane permeability. Depth scan SECM imaging allowed for the generation of 2D current maps of live cells relative to electrode position in the x-z or y-z plane. Depending on resolution, one depth scan image can contain hundreds of probe approach curves (PACs). Individual PACs were obtained by simply extracting vertical cross-sections from the 2D image. These experimental PACs were overlaid onto theoretically generated PACs simulated at specific geometry conditions. Simulations were carried out using 3D models in COMSOL Multiphysics to determine the cell membrane permeability coefficients at different locations on the surface of the cells. Common in literature, theoretical PACs are generated using a 2D axially symmetric geometry. This saves on both compute time and memory utilization. However, due to symmetry limitations of the model, only one experimental PAC right above the cell can be matched with simulated PAC data. Full 3D models in this article were developed for the SECM system of live cells, allowing all experimental PACs over the entire cell to become usable. Cd2+-induced membrane permeability changes of single human bladder (T24) cells were investigated at several positions above the cell, displaced from the central axis. The experimental T24 cells under study were incubated with Cd2+ in varying concentrations. It is experimentally observed that 50 and 100 μM Cd2+ caused a decrease in membrane permeability, which was uniform across all locations over the cell regardless of Cd2+ concentration. The Cd2+ was found to have detrimental effects on the cell, with cells shrinking in size and volume, and the membrane permeability decreasing. A mapping technique for the analysis of the cell membrane permeability under the Cd2+ stress is realized by the methodology presented.

Promotive effects of 5-Aminolevulinic acid on growth, photosynthetic gas exchange, chlorophyll, and antioxidative enzymes under salinity stress in Prunnus persica (L.) Batseh Seedling

The physiological characteristics of peach seedlings (Prunnus persica L. Batseh) under salt stress were investigated to ameliorate the effects of 5-aminolevulinic acid (ALA). Physiological indices of salt-stressed peach seedlings treated with exogenous ALA were investigated; these indices included stem diameter, plant height, leaf area, aboveground and underground weights, net photosynthetic rate (Pn), transpiration rate (Tr), intercellular CO2 concentration (Ci), stomatal conductance (Gs), root vitality, and membrane permeability. The contents of chlorophyll, malondialdehyde (MDA), soluble sugars, soluble proteins, and proline as well as the activities of antioxidant enzymes were evaluated. Results showed that the physiological characteristics of peach seedlings under NaCl stress (100 mM) were inhibited. Peach seedlings treated with100 mM NaCl and 200mg/l ALA for every germination index recovered. Moreover, peach seedlings treated with 200mg/l ALA exhibited enhanced physiological characteristics. Treatment with exogenous ALA increased stem diameter, plant height, leaf area, aboveground and underground weights, net photosynthetic rate (Pn), transpiration rate (Tr), intercellular CO2 concentration (Ci), stomatal conductance (Gs), and root vitality. The treatment also increased the contents of chlorophyll, soluble sugars, soluble proteins, and proline but decreased membrane permeability and MDA content. Furthermore, treatment with ALA significantly enhanced the activities of superoxide dismutase, peroxidase, and catalase. These findings indicate that exogenous ALA treatment could improve the growth and relieve the salt stress injury of peach seedlings by increasing photochemical efficiency, osmotic content, and antioxidant enzyme activity.

Efficacy of goreisan for asymptomatic bilateral and unilateral chronic subdural hematoma

Aim Chronic subdural hematoma (CSDH) is a common neurosurgical clinical entity but the complication rates are not well established. Almost all CSDH patients undergo surgical intervention, but some patients are treated pharmacologically. In this study, we investigated the medical treatment of asymptomatic or mild symptomatic CSDH using only goreisan. Methods Eight patients with unilateral/bilateral CSDH without neurological disorder were given goreisan. Maximum vertical thickness of CSDH slice was measured on neuroradiological imaging. Treatment duration was defined as the period from when goreisan was first prescribed to the last visit, when either resolution of CSDH or neurosurgical intervention were indicated. Results Eight patients with 11 lesions (three patients had bilateral CSDH) were enrolled in this study and treated with only goreisan. The median treatment duration was 10 weeks. Two patients required surgery because of hematoma increase with neurological deterioration. Six of eight patients did not require surgery. Conclusions Medical treatment using goreisan for asymptomatic CSDH was effective. Some studies have demonstrated that aquaporin-4 (AQP4) plays an important role in CSDH. In recent studies, goreisan was found to inhibit AQP4 expressed on the outer membrane of CSDH. In the present patients, goreisan may have inhibited AQP4 on the outer membrane of CSDH, thereby decreasing membrane permeability. Therefore, we speculate that goreisan causes a decrease in CSDH hematoma volume. Furthermore, we speculate that goreisan may be associated with the inflammation process, thereby resolving CSDH.