Changes In Ionic Composition Research Articles

5 Properties of real phototherapy laser and LED devices

Much of our understanding of dendritic and synaptic physiology comes from in vitro experimentation, where the afforded mechanical stability and convenience of applying drugs allowed patch-clamping based recording techniques to investigate ion channel distributions, their gating kinetics, and to uncover dendritic integrative and synaptic plasticity rules. However, with current efforts to study these questions in vivo, there is a great need to translate existing knowledge between in vitro and in vivo experimental conditions. In this review, we identify discrepancies between in vitro and in vivo ionic composition of extracellular media and discuss how changes in ionic composition alter dendritic excitability and plasticity induction. Here, we argue that under physiological in vivo ionic conditions, dendrites are expected to be more excitable and the threshold for synaptic plasticity induction to be lowered. Consequently, the plasticity rules described in vitro vary significantly from those implemented in vivo.

Modeling the seasonal variability of the plasma environment in Saturn's magnetosphere between main rings and Mimas

The detection of O2+ and O+ ions over Saturn's main rings by the Cassini INMS and CAPS instruments at Saturn orbit insertion (SOI) in 2004 confirmed the existence of the ring atmosphere and ionosphere. The source mechanism was suggested to be primarily photolytic decomposition of water ice producing neutral O2 and H2 (Johnson et al., 2006). Therefore, we predicted that there would be seasonal variations in the ring atmosphere and ionosphere due to the orientation of the ring plane to the sun (Tseng et al., 2010). The atoms and molecules scattered out of the ring atmosphere by ion–molecule collisions are an important source for the inner magnetosphere (Johnson et al., 2006; Martens et al., 2008; Tseng et al., 2010, 2011). This source competes with water products from the Enceladus' plumes, which, although possibly variable, do not appear to have a seasonal variability (Smith et al., 2010). Recently, we found that the plasma density, composition and temperature in the region from 2.5 to 3.5RS exhibited significant seasonal variation between 2004 and 2010 (Elrod et al., submitted for publication). Here we present a one-box ion chemistry model to explain the complex and highly variable plasma environment observed by the CAPS instrument on Cassini. We combine the water products from Enceladus with the molecules scattered from a corrected ring atmosphere, in order to describe the temporal changes in ion densities, composition and temperature detected by CAPS. We found that the observed temporal variations are primarily seasonal, due to the predicted seasonal variation in the ring atmosphere, and are consistent with a compressed magnetosphere at SOI.

Stabilization and Structure Determination of the Recombinant C-Terminal Domain of Nephila Clavipes Dragline Silk

Spider silk, as simple as it may look, holds a secret which lies in the processing of the silk proteins from a highly concentrated soluble state to the insoluble fiber. The conserved C-terminal domain of MaSp1, the dragline silk main protein, appears to play a key role in the control of solubility and fiber formation initiated by changes in ionic composition, mechanical stimuli or pH variations along the secretory gland ducts. Therefore, the study of its structure is necessary to understand this remarkable molecular behaviour. We have established a purification protocol to prevent the aggregation of the recombinant Nephila clavipes MaSp1 C-terminal domain. We have also investigated the structure of the protein using solution nuclear magnetic resonance (NMR), dynamic light scattering (DLS) and fluorescence spectroscopy. NMR diffusion and DLS experiments provide information about the oligomerization and aggregation of the protein. Further NMR experiments with the doubly 13C/15N labelled protein will lead to the complete determination of the protein structure.

Variation in the Changes Induced by Different Forms of Tobacco in Dental Hard Tissues-A SEM-EDAX Study

Objective: Tobacco, which annually kills 4.9 million people worldwide at present, is estimated to take 10 million lives every year by 2020 and India has been cited as the country with highest incidence. Multiple studies have been done to study the effects of tobacco on soft tissue with very few on hard tissues. So, in this study we evaluated the effects of tobacco on teeth by determining the weight % of various ions. Material & Methods: This preliminary study was designed including various categories according to habits. The samples of teeth were analyzed under the advanced SEM-Energy Dispersive Analysis of X-rays to examine the change in ionic composition of enamel in tobacco users and non-users. Results: Increase in weight % of ions like Sulphur (S), Magnesium (Mg) and Aluminium (Al) was noted depending on the habit. The weight % of these ions was highest in category II with a mixed habit of gutka, kharra, tobacco lime quid and smoking as compared to other groups. The weight % of these ions was also significantly more in category III and IV as compared to category I of unstained teeth. Conclusion: The results showed that there is a chemical alteration induced by tobacco in teeth, i. e., increase in levels of Al, S, Mg. It is postulated that this may result in the increase of these ions in saliva in due course of time. Ions like Al and S are known to make a cell more prone towards carcinogenesis. So, increase in concentration of these ions in saliva may make a cell prone towards carcinogens.

Variation in the Changes Induced by Different Forms of Tobacco in Dental Hard Tissues—A SEM-EDAX Study

Objective: Tobacco, which annually kills 4.9 million people worldwide at present, is estimated to take 10 million lives every year by 2020 and India has been cited as the country with highest incidence. Multiple studies have been done to study the effects of tobacco on soft tissue with very few on hard tissues. So, in this study we evaluated the effects of tobacco on teeth by determining the weight % of various ions. Material & Methods: This preliminary study was designed including various categories according to habits. The samples of teeth were analyzed under the advanced SEM-Energy Dispersive Analysis of X-rays to examine the change in ionic composition of enamel in tobacco users and non-users. Results: Increase in weight % of ions like Sulphur (S), Magnesium (Mg) and Aluminium (Al) was noted depending on the habit. The weight % of these ions was highest in category II with a mixed habit of gutka, kharra, tobacco lime quid and smoking as compared to other groups. The weight % of these ions was also significantly more in category III and IV as compared to category I of unstained teeth. Conclusion: The results showed that there is a chemical alteration induced by tobacco in teeth, i.e., increase in levels of Al, S, Mg. It is postulated that this may result in the increase of these ions in saliva in due course of time. Ions like Al and S are known to make a cell more prone towards carcinogenesis. So, increase in concentration of these ions in saliva may make a cell prone towards carcinogens.

Ion flux and the function of endosomes and lysosomes: pH is just the start

The ionic nature of endosomes varies considerably in character along the endocytic pathway. Counter-ion flux across the limiting membrane of endosomes has long been considered essential for full acidification and normal endosome/lysosomal function. The proximal functions of luminal ions, however, have been difficult to assess. The recent development of transgenic mice carrying mutations in the intracellular chloride channels (ClCs) has provided a tool to uncouple Cl(-) influx from endosomal acidification. Intriguingly, many of the defects of the endo-lysomal system attributed to aberrant pH persist in the Cl(-)-deficient mice implying a direct regulatory role for Cl(-) influx in endosome function. These observations may begin to explain the abundance of endosomal ion transporters, including ClCs, sodium-proton exchangers, two-pore channels and mucolipins, that have been localized to endo-lysosomes, and the extensive changes in luminal ion composition therein. In this review, we summarize what is known regarding the mediators of endosomal ion flux, and discuss the implications of changing ionic content on endo-lysosomal function.

Gelation of casein micelles in β-casein reduced milk prepared using membrane filtration

Pasteurized skim milk was subjected to membrane filtration using a molecular weight cut-off of 80 kDa and a plate and frame pilot scale system at temperatures below 10 °C. Via this process, transmission of whey proteins and β-casein through the membrane was achieved. The milk was concentrated to two times (based on volume reduction), and whey protein-free permeate was added to return to the original volume fraction of casein micelles in milk. This diafiltration process was carried out four times, and the retentate obtained was nearly free of whey proteins and with approximately 20% of β-casein removed. The same membrane filtration was also carried out at 25 °C to achieve transmission of whey protein but not of β-casein, and to obtain whey protein-depleted milk without depletion of β-casein. The gelling behaviour of these samples, reconstituted to the original casein volume fraction, was examined using rheology and diffusing wave spectroscopy. When compared to the original skim milk it was found that there were no statistically significant differences in gelation behaviour during acidification, but differences were noted in gelation time and final stiffness modulus for samples undergoing renneting. These differences were attributed mostly to the changes in ionic composition, as when the serum composition of the retentates was re-equilibrated against the original skim milk by dialysis; the gelation behaviour of the samples was comparable to that of skim milk. The results clearly indicate the importance of the milk's overall ionic balance in the early stages of aggregation of rennet-induced gelation of milk.

Characterization of particle cloud droplet activity and composition in the free troposphere and the boundary layer during INTEX-B

Abstract. Measurements of cloud condensation nuclei (CCN), aerosol size distributions, and submicron aerosol composition were made as part of the Intercontinental Chemical Transport Experiment Phase B (INTEX-B) campaign during spring 2006. Measurements were conducted from an aircraft platform over the northeastern Pacific and western North America with a focus on how the transport and evolution of Asian pollution across the Pacific Ocean affected CCN properties. A broad range of air masses were sampled and here we focus on three distinct air mass types defined geographically: the Pacific free troposphere (FT), the marine boundary layer (MBL), and the polluted continental boundary layer in the California Central Valley (CCV). These observations add to the few observations of CCN in the FT. CCN concentrations showed a large range of concentrations between air masses, however CCN activity was similar for the MBL and CCV (κ~0.2–0.25). FT air masses showed evidence of long-range transport from Asia and CCN activity was consistently higher than for the boundary layer air masses. Bulk chemical measurements predicted CCN activity reasonably well for the CCV and FT air masses. Decreasing trends in κ with organic mass fraction were observed for the combination of the FT and CCV air masses and can be explained by the measured soluble inorganic chemical components. Changes in hygroscopicity associated with differences in the non-refractory organic composition were too small to be distinguished from the simultaneous changes in inorganic ion composition in the FT and MBL, although measurements for the large organic fractions (0.6–0.8) found in the CCV showed values of the organic fraction hygroscopicity consistent with other polluted regions (κorg~0.1–0.2). A comparison of CCN-derived κ (for particles at the critical diameter) to H-TDMA-derived κ (for particles at 100 nm diameter) showed similar trends, however the CCN-derived κ values were significantly higher.

Editorial [ Hot topic: Aquaporins and Nervous System: from Bench to Bedside (Guest Editors: Rita Rezzani and Luigi F. Rodella)

Water is the single most abundant substance in cells and organisms and is an important molecule involved in several biochemical processes present in living cells. In humans 60-70% of body weight is water which equilibrates across the lipid bilayer in cell membranes. Forty years ago, a small number of scientists argued that specialized water-selective pores are necessary to explain the high water permeability of red blood cells and renal tubules. Therefore, the molecular identification of a 28 kDa integral membrane protein in these cells has characterized a new stream of research. Aquaporins (AQPs) are membrane proteins that transport water and, in some cases, also small solutes such as glycerol and urea. Each subtype has its own cellular distribution and distinct regulatory mechanisms of their expression. Their classical role in facilitating trans-epithelial fluid transport is well understood, as in the urinary concentrating mechanism and gland fluid secretion, while the molecular mechanisms to regulate water permeability in the nervous system are still unclear. Maintenance of the ionic and osmotic composition and volume of interstitial, glial and neuronal compartments within the nervous system is essential for normal function. Small changes in intracellular or extracellular ion or solute composition can dramatically modify bi-directional water pathway between the brain and blood vessels and alter cerebrospinal fluid formation, neural signal transduction and information processing. To date, only some AQP isoforms (AQP1, 3, 4, 5, 8, 9) have been reported in the central nervous system being identified in choroidal cells (AQP1), astrocytes (AQP1, 3, 4, 5, 8, 9), oligodendrocytes (AQP8), neurons (AQP1, 5, 8), tanycytes (AQP9) and ependymal cells (AQP1, 4, 9). In contrast to numerous studies of AQP localization and function in the central nervous system, little information is available on the expression and function of AQPs in peripheral nervous system. This issue includes six review articles in which the authors report and explore the recent findings about the involvement of AQPs both in peripheral and central nervous system. The paper by B. Buffoli summarizes the data about the structure, regulation and function of AQPs, giving more importance to their involvement in the nervous system and underlying the development of new methods for diagnosis and therapy diseases. The review of R. Albertini and R. Bianchi is focused on the different isoforms of AQP protein that have been identified in glial cells in central and peripheral nervous system and in reactive microglial. The chapter supports the idea that AQPs are involved in water homeostasis during different glial cell functions, such as differentiation, metabolism and excitability of neurons. F. Bonomini and R. Rezzani emphasize the role of some AQPs present in glial cells in the maintenance or/and in the regulatory mechanisms of blood brain barrier. On the basis of the role of AQPs in brain edema, a personal account of the role of AQPs is then presented by C. Loreto and E. Reggio, who summarized the implication of different isoforms of these proteins in relation with vascular diseases and nervous system. In the literature, there is a lot of evidence that indicates a correlation between the expression of AQPs and the development of neurodegenerative diseases in which preservation of brain homeostasis is at risk. The review of E. Foglio and L.F. Rodella was to consider this topic concentrating on some neurodegenerative diseases, such as Neuromyielitis Optica, Alzheimer’s Diseases, Parkinson’s Diseases, Amyotrophic lateral sclerosis, Transmissible Spongiform Encephalopathies. Recent evidence suggests a novel role of AQPs in pain transmission both in the central and peripheral nervous system. In this issue, E. Borsani reports the modulation of AQPs both in inflammatory and neuropathic pain considering different animal models and knock-out animals. In the future, the numerous ongoing studies will certainly reveal other multifunctional roles of these proteins in humans. These roles might be exploited clinically by the development of drugs to alter AQP expression or function that could serve in the treatment of different diseases associated to peripheral and central nervous system.

A conserved spider silk domain acts as a molecular switch that controls fibre assembly

A huge variety of proteins are able to form fibrillar structures, especially at high protein concentrations. Hence, it is surprising that spider silk proteins can be stored in a soluble form at high concentrations and transformed into extremely stable fibres on demand. Silk proteins are reminiscent of amphiphilic block copolymers containing stretches of polyalanine and glycine-rich polar elements forming a repetitive core flanked by highly conserved non-repetitive amino-terminal and carboxy-terminal domains. The N-terminal domain comprises a secretion signal, but further functions remain unassigned. The C-terminal domain was implicated in the control of solubility and fibre formation initiated by changes in ionic composition and mechanical stimuli known to align the repetitive sequence elements and promote beta-sheet formation. However, despite recent structural data, little is known about this remarkable behaviour in molecular detail. Here we present the solution structure of the C-terminal domain of a spider dragline silk protein and provide evidence that the structural state of this domain is essential for controlled switching between the storage and assembly forms of silk proteins. In addition, the C-terminal domain also has a role in the alignment of secondary structural features formed by the repetitive elements in the backbone of spider silk proteins, which is known to be important for the mechanical properties of the fibre.

Role of pH regulatory components in the transduction response of central CO2 chemoreceptors

Increased levels of CO2 (hypercapnic acidosis, HA) acidify central CO2 chemoreceptors resulting in a change in neuronal excitability that drives ventilation. Recently, we developed a mathematical model that combines a minimal Hodgkin‐Huxley (HH)‐based expression of neuronal excitability with a robust transport model based on the Goldman‐Hodgkin‐Katz (GHK) equation, and used this model to study excitability in response to HA. We found that HA induced small passive changes in ionic composition that modulated membrane potential (Vm), but the firing rate changes observed were not wholly consistent to those reported in the literature, suggesting that pH‐sensitive currents may be required. Although previous HH‐based single‐compartment neuron models have been developed to investigate CO2 chemoreception, these models contain only an estimate of pH regulatory fluxes. To overcome the limitations of the existing models, we have (1) expanded our model to include pH‐sensitive currents proposed to participate in CO2 chemoreception and (2) identified the role of each current in modulation of Vm. We found that the expanded model with kinetic descriptions for pH regulatory mechanisms, HA‐induced small passive changes in ionic composition, and pH‐sensitive currents best captures the neuronal response to HA. We suggest that all components be included in transduction models of CO2 chemoreception. Supported by NS045321

Developmental changes in the ENaC channel of the chick chorioallantoic membrane

Confined to the closed system of the egg, the chick embryo deposits its renal wastes into the chorioallantoic sac, an outgrowth of its hindgut. The allantoic fluid undergoes changes in both volume and ion composition throughout the development of the embryo. These changes are most likely the result of Na+ reabsorption from the allantoic fluid. In previous experiments we demonstrated that short‐circuit current across the epithelia increases five‐fold between embryonic days 9–19. This current is inhibitable by ouabain and amiloride, indicating that Na+‐K+‐ATPase and ENaC channels play a role. Aldosterone increased the amiloride‐inhibitable current from day 9 to day 18, suggesting that the ENaC channels may be up‐regulated by the hormone. The slow (100 min) aldosterone response appears to be the classic gene‐regulated response to a steroid hormone. In this study we are investigating the role of the epithelial sodium channel ENaC in allantoic short‐circuit current. We used RT‐PCR to measure normal developmental changes in the RNA message of the three ENaC subunits in the allantoic epithelium. The RNA message of all subunits increased two‐fold from day 9 to day 11, and then slowly decreased from days 11 to 17. These data were confirmed using Western blots. Subsequent experiments will investigate the role of aldosterone in inducing ENaC protein synthesis.

Residues Important for Nitrate/Proton Coupling in Plant and Mammalian CLC Transporters

Members of the CLC gene family either function as chloride channels or as anion/proton exchangers. The plant AtClC-a uses the pH gradient across the vacuolar membrane to accumulate the nutrient NO(3)(-) in this organelle. When AtClC-a was expressed in Xenopus oocytes, it mediated NO(3)(-)/H(+) exchange and less efficiently mediated Cl(-)/H(+) exchange. Mutating the "gating glutamate" Glu-203 to alanine resulted in an uncoupled anion conductance that was larger for Cl(-) than NO(3)(-). Replacing the "proton glutamate" Glu-270 by alanine abolished currents. These could be restored by the uncoupling E203A mutation. Whereas mammalian endosomal ClC-4 and ClC-5 mediate stoichiometrically coupled 2Cl(-)/H(+) exchange, their NO(3)(-) transport is largely uncoupled from protons. By contrast, the AtClC-a-mediated NO(3)(-) accumulation in plant vacuoles requires tight NO(3)(-)/H(+) coupling. Comparison of AtClC-a and ClC-5 sequences identified a proline in AtClC-a that is replaced by serine in all mammalian CLC isoforms. When this proline was mutated to serine (P160S), Cl(-)/H(+) exchange of AtClC-a proceeded as efficiently as NO(3)(-)/H(+) exchange, suggesting a role of this residue in NO(3)(-)/H(+) exchange. Indeed, when the corresponding serine of ClC-5 was replaced by proline, this Cl(-)/H(+) exchanger gained efficient NO(3)(-)/H(+) coupling. When inserted into the model Torpedo chloride channel ClC-0, the equivalent mutation increased nitrate relative to chloride conductance. Hence, proline in the CLC pore signature sequence is important for NO(3)(-)/H(+) exchange and NO(3)(-) conductance both in plants and mammals. Gating and proton glutamates play similar roles in bacterial, plant, and mammalian CLC anion/proton exchangers.

Evolutionary conditioning of response to changes in ionic composition of water in hydrobionts: An example of freshwater zooplankton

The situation in Karelian water bodies polluted with mining waste has been analyzed. As a result of technogenic wastewater discharge, the total ion content in lake waters has increased tens of times, and the concentration of potassium ions (the main component of wastewater), hundreds of times. Pollution tolerance of hydrobiont populations depends on the historically developed adaptation potential of species. The lowest tolerance to mineral pollution is characteristic of crustaceans representing mesolimnic families Polyphemidae, Sididae, Leptodoridae, Holopedidae, Diaptomidae, and Temoridae. Representatives of paleolimnic cristacean families Daphniidae, Bosminidae, and Cycopidae as well rotifer (Rotatoria) species of freshwater origin are highly tolerant of changes in the ionic composition of water.

Ongoing Changes of Ionic Composition and Dissolved Gases in the Aral Sea

Starting from 1961, the Aral Sea, a major saline lake in Central Asia, has been continuously shrinking because of deficiency in its water budget. Accordingly, the salinity of the once brackish lake increased by a factor of magnitude. During the desiccation, the salt composition of the Aral Sea has been subject to continuous changes because of chemical precipitation accompanying the salinity buildup. This paper provides a summary of these changes based on water samples collected from the so-called Large Aral Sea during the field surveys of 2002–2007. Once fully ventilated, the lake developed anoxic conditions and H2S contamination is frequently observed in the bottom layers. However, hydrogen sulfide is a variable rather than a permanent feature of the present Aral Sea. Because of the precipitation of calcium carbonate, gypsum, and, possibly, mirabilite, which successively occurred as the salinity increased, the relative content of SO4− and Ca2+ ions decreased. Accordingly, compared with the pre-desiccation period before 1960, the sulfate-to-chloride mass ratio decreased by 10–30%, while the relative content of calcium decreased almost 7-fold. The depletion in calcium is more pronounced in the shallow eastern part of the lake, where salinity is much higher. However, the reduction of the sulfate-to-chloride ratio in the eastern basin is smaller than that for the western basin of the Aral Sea. Hypothetically, this could be explained through precipitation of halite already taking place in the eastern basin, but not yet in the western basin. Vertical profiles of the ionic content in the relatively deep western part of the lake reveal a decrease of calcium content and relative increase of sulfate ion content toward the bottom, which is consistent with the previously published concept that the bottom layers of the western trench contain a significant admixture of the water advected from the eastern basin.

Ionic composition of seawaters and derived saline solutions determined by ion chromatography and its relation to other water quality parameters

Ion chromatography (IC) presents new possibilities for assessing information about environmental samples, namely waters of various compositions, ranging from high-purity water to highly saline ones. Constant proportion between major ions present in seawater, has been assumed in the past, from which the first practical equation relating chlorinity and salinity has been developed, being later substituted by a practical salinity scale, derived from conductivity measurements relative to a standard seawater, according to internationally accepted recommended procedures. Seawaters are characterized by salinity values around 35 while derived saline solutions may present considerable changes in ionic composition, conductivity, hence on salinity. Natural and anthropogenic phenomena may introduce new issues requiring clarification for which qualitative and quantitative information from additional sources is useful, e.g. ionic composition from IC. The different ranges of concentration of major and minor species present in seawater and derived saline solutions are a challenge for the optimization of a practical methodology for composition assessment in two single IC runs, one for anions and another one for cations, which has been attained in this work. Composition of saline solutions determined by IC was critically assessed in terms of anion–cation balance and further related to conductivity and salinity measurements aiming to evaluate the quality/completeness of ion chromatographic analyses performed at preselected conditions and to search for other meaningful relations for efficient recognition/distinction between saline solutions of different types.

Changes in interstitial K+ and pH during exercise: implications for blood flow regulation

The analysis of blood samples has clearly demonstrated that exercise is associated with the release of K+ and H+ from muscle. However, blood samples give only incomplete information about the ion changes in the muscle interstitium. Interstitial changes in ion composition may affect the transport properties of the sarcolemmal membrane, may affect fibre excitability and induce fatigue, and may affect sensory nerve endings. Therefore, to better understand muscle function, it is important to quantify the exercise-induced interstitial ion changes. Both interstitial K+ and H+ changes have been quantified with the microdialysis technique. Interstitial K+ accumulation is dependent on the intensity and duration of muscle activity and may reach 10 mmol/L during intense exercise, and the concentration in T-tubules may be even higher. Thus, interstitial K+ can reach a level that affects fibre excitability and the development of fatigue. It has also been demonstrated with microdialysis that the interstitial decrease in pH during muscle activity is larger than the reduction in blood pH. Ion changes in the interstitium may affect blood flow directly or indirectly. Infusion of K+ into the femoral artery in humans has demonstrated that blood flow is affected by changes in K+ as low as 0.1 mmol/L. The vasodilatory effect of K+ can be inhibited with simultaneous barium infusion, indicating that inward rectifier potassium (Kir)channels are involved. Acidosis has a direct effect on blood flow and an indirect effect, mediated by changes in other vasoactive compounds.

Metabolic stress as a contributor to physiological opening of TRP channels in blowfly (Calliphora vicina)

Abstract Purpose: TRP channels in blowflies can be reversibly activated by metabolic stress. Activation can be caused by hypoxia or mitochondrial uncoupling and results in membrane depolarization. The changes where traced as changes in extracellular ionic composition, photoreceptor membrane currents and changes in membrane potential. Idea of specific signaling pathway opening TRP channels was rejected with findings that impairment of PIP2 under lack of ATP, results in activation of TRP channels. Even though the mechanism of metabolic stress TRP channel activation is elucidated, it remained unanswered what rate of metabolic stress is needed to open the channels and whether under physiological conditions photoreceptor cells encounter the rate of metabolic stress that can significantly contribute to opening of TRP channels. Methods: Extracellular concentrations of [K+]o, [Na+]o and [Ca2+]o were measured using the ion‐selective microelectrodes. The redox states of respiratory pigments (flavoproteins and cytochromes) in the eyes of blowflies (Calliphora vicina) were measured with time‐resolved absorption spectroscopy and use of principal components analysis. Anoxia was reached in under 2s time. Results: Changes in [K+]o, [Na+]o and [Ca2+]o appeared with latency of 8.06 ± 1.38 s, 10.38 ± 2.48 s and 13.11 ± 3.09 s, respectively (mean ± s.e.m., n=7). First detectable changes in redox state of cytochrome c respiratory pigment started at 1.79 ± 0.19 s and reached 39.4% ± 5.4 % of the maximal reduction by the time changes in ionic composition were detectable. Conclusions: Our conclusion was that high degree of maximal redox state change is needed (39.4%) to open TRP channels, what is unlikely to happen under physiological conditions.

The role of the inflammasome in cellular responses to toxins and bacterial effectors

Invading pathogens are recognized by mammalian cells through dedicated receptors found either at the cell surface or in the cytoplasm. These receptors, like the trans-membrane Toll-like Receptors (TLR) or the cytosolic Nod-like Receptors (NLR), initiate innate immunity after recognition of molecular patterns found in bacteria or viruses, such as LPS, flagellin, or double-stranded RNA. Recognition of molecules produced only by a specific pathogen, such as a viral envelop protein or a bacterial adhesin does not appear to occur. Bacterial protein toxins, however, might compose an intermediate class. Considering the diversity of toxins in terms of structure, it is unlikely that cells respond to them via specific molecular recognition. It rather appears that different classes of toxins trigger cellular changes that are sensed by the cells as danger signals, such as changes in cellular ion composition after membrane perforation by pore-forming toxins or type III secretion systems. The signaling pathways triggered through toxin-induced cell alterations will likely play a role in modulating host responses to virulent bacteria. We will here describe the few studied cases in which detection of the toxin by the host cell was addressed. The review will include not only toxins but also bacteria effectors secreted by the bacterium in to the host cell cytoplasm.

Temporal variations in osmoregulatory solutes with reference to saline habitat and habits in two species ofTrianthema

Highly significant temporal variations of salinity, Na + and Cl − content were observed in the habitat. Although quantity of major amino acids was significantly different in leaves, stems and roots of Trianthema monogyna L. and T. triquetra Rott. ex Willd., their concentrations did not reflect any temporal effects. Accumulation of sugars in vegetative organs and their fluctuations were not significant for thin leaved species T. monogyna , but their content in T. triquetra was affected by temporal changes. Amounts of Na + , Cl − , Ca 2+ and K + in plant organs were positively related with changes in salinity and mineral ion composition of the habitat. Two species remarkably differed in accumulating amino acids, sugars and mineral ions.