Binding of lithium and boron to human plasma proteins II

We report further measurements of lithium and boron bound to human plasma proteins using the techniques of gel chromatography, thermal-neutron activation, and high-sensitivity helium isotope mass spectrometry. The plasma sample was donated by a bipolar patient who had never been on lithium therapy. The plasma lithium-binding pattern for the bipolar patient is distinctly different from that previously observed in this laboratory for plasma donated by a normal individual. In the bipolar case, virtually all of the lithium is bound to low-molecular-weight proteins (approx 1000 amu), whereas in the normal case, most of the lithium eluted from the gel column was bound to five high-molecular-weight proteins (approx 50,000 amu to approx 1,000,000 amu). The gel elution profiles for boron were roughly similar for the normal and bipolar cases. The lithium results are in agreement with our previous speculation that lithium-binding plasma proteins are missing or exist in very low concentrations in some individuals suffering from affective disorders.     

Distribution of selenium-containing proteins in human serum

This study was undertaken to compare endogenous lithium concentrations in human blood and its components from normal donors versus bipolar patients. The patients were not on lithium therapy at the time that the blood samples were donated and had not received any lithium therapy for at least 2 yr. Blood components were separated by centrifugation. The analytical method for lithium as developed in this laboratory consists of thermal-neutron activation of freeze-dried samples. ³H is produced via the reaction ⁶Li+n=³H+⁴He, and high-sensitivity rare gas mass spectrometry is used to measure ³He formed from β-decay of ³H. Boron measurements are made concurrently using ⁴He from the reaction ¹⁰B+n=⁴He+⁷Li. Seven normal donors and seven patients with a diagnosis of bipolar disorder participated in this study. Measurements of lithium and boron were made in whole blood, plasma, and red cells. Red cell-plasma ratios R(Li) and R(B) were calculated after corrections were made for trapped plasma in the red cells. The results show that bipolar patients may have higher concentrations of lithium in blood, plasma, and red cells (p=0.08, 0.02, and 0.02, respectively) and may have higher R(Li) values than normal donors (p=0.01). No evidence was found for bipolar-normal differences in these four parameters for boron. Although our sample size is admittedly very small, the results clearly show that the endogenous red cell ratio R(Li) and plasma or red cell lithium concentrations may become useful diagnostic indicators for bipolar illness if the analytical methods are further developed. Certain commercial equipment, instruments, or materials are identified in this article to specify adequately the experimental procedure. Such identification does not imply recommendation or endorsement by the National Institute of Standards and Technology, nor does it imply that the materials or equipment identified are necessarily the best available for the purpose. Prof. Clarke died unexpectedly on September 3, 2002.     

Determination of Boron Contents in Water Samples Collected from the Neelum valley,Azad Kashmir,Pakistan

Intake of boron from food and drinking water may pose a risk to the public health above a certain concentration level. Therefore, knowledge of boron concentration in drinking water and food items is essential. In this context, samples of drinking water were collected from natural springs of the Neelum valley, Azad Kashmir, hit by devastating earthquake in 2005. In these samples, boron concentration was determined using neutron-induced radiography technique. To do so, unknown water samples, along with standard of known boron dried on CR-39 detectors, were irradiated with thermal neutrons. After exposure, CR-39 detectors were etched in 6 M NaOH at 70°C. The tracks produced due to the alpha particles and ⁷Li ions as a result of ¹⁰B(n,α)⁷Li reaction were counted under an optical microscope. The tracks produced in theses samples were then related to the boron contents. The measured boron concentration in water samples was found to vary from 0.105 ± 0.005 to 0.247 ± 0.013 mg/l with an average value of 0.17 ± 0.04 mg/l, which are within the acceptable limits.     

Deposition and cycling of carbon and nitrogen in carbonate mud of the lagoons of Arlington and Sudbury Reefs, Great Barrier Reef

The dynamics of carbon and nitrogen in carbonate mud were examined in the lagoons of Arlington and Sudbury Reefs, Great Barrier Reef. Most (89–93%) of the organic carbon and total nitrogen depositing to the carbonate mud zones was mineralized over a sediment depth of 1 m, with ∼50% of CO₂ produced during microbial decomposition involved in carbonate precipitation/dissolution reactions. There was proportionally little burial of organic carbon (10–11%) or nitrogen (7–10%). Nitrogen budgets suggest rapid turnover of porewater inorganic N pools on the order of hours to a few days. Incubation experiments indicate carbonate dissolution in surface deposits (≤20 cm depth) and carbonate precipitation in deeper sediments. Depth-integrated reaction rates indicate net carbonate precipitation of 7–10 mol CaCO₃ m² year⁻¹ over a depth of 1 m. Budget calculations at the whole-reef scale imply that deposition of CaCO₃ in the mud zones of both lagoons may equate to 50–90% of total reef carbonate production, with organic carbon fluxes equating to nearly all net primary production on each reef. These biogeochemical estimates point to the functional importance of carbonate mud zones in the lagoons of the shelf reefs of the Great Barrier Reef.     

Altered expression and glycosylation of plasma proteins in rheumatoid arthritis

Altered glycosylation of plasma proteins has been directly implicated in the pathogenesis of rheumatoid arthritis (RA). The present study investigated the changes in the Concanavalin-A (Con-A)-bound plasma proteins in the RA patients in comparison to that of the healthy controls. Two proteins (MW ∼32 kDa and ∼62 kDa) showed an alteration in expression while an altered monosaccharide profile (high mannose) was observed in the ∼62 kDa protein in the samples collected from RA patients. The 2-dimensional polyacrylamide gel electrophoresis analysis of the Con-A-bound plasma samples showed a large number of protein spots, a few of which were differentially expressed in the RA patients. Some unidentified proteins were detected in the RA patients which were absent in the control samples. The present study, therefore, enunciates the role of carbohydrates as well as that of the acute phase response in the disease pathogenesis.     

Diagnostics of plasma produced by femtosecond laser pulse impact upon a target with an internal nanostructure

X-ray diagnostics of the interaction of femtosecond laser pulses with intensities of 10¹⁶–10¹⁸ W/cm² with CO₂ clusters and frozen nanosize water particles is carried out. The stage of cluster expansion and the formation of a plasma channel, which governs the parameters of the formed X-ray radiation source and accelerated ion flows, is studied. The measurements are based on recording spatially resolved X-ray spectra of H- and He-like oxygen ions. Utilization of Rydberg transitions for spectra diagnostics makes it possible to determine plasma parameters on a time scale of t ∼ 10 ps after the beginning of a femtosecond pulse. The role of the rear edge of the laser pulse in sustaining the plasma temperature at a level of ∼100 eV in the stage of a nonadiabatic cluster expansion is shown. The analysis of the profiles and relative intensities of spectral lines allows one to determine the temperature and density of plasma electrons and distinguish the populations of “thermal” ions and ions that are accelerated up to energies of a few tens of kiloelectronvolts. It is shown that the use of solid clusters made of frozen nanoscale water droplets as targets leads to a substantial increase in the number of fast He-like ions. In this case, however, the efficiency of acceleration of H-like ions does not increase, because the time of their ionization in plasma exceeds the time of cluster expansion.     

Differential response of chloride binding sites to elevated temperature: a comparative study in spinach thylakoids and PSII-enriched membranes

A study of heat effects was performed in thylakoids and photosystem II (PSII)-enriched membranes isolated from spinach in relation to Cl⁻-induced activation of PSII catalyzed oxygen evolution and the retention of Cl⁻ in the PSII complex. For this, Cl⁻-sufficient membranes and low-Cl⁻ membranes were used. The presence of Cl⁻ in the reaction medium did accelerate oxygen evolution, which remained unaffected by heat treatment up to 40°C in PSII membranes and up to 42.5°C in thylakoids. Heat resistance of Cl⁻-induced activation of oxygen evolution was found to be independent of the presence of ‘bound Cl⁻’ in the preparations. However, the functional stability of the PSII complex during heat treatment showed a marked dependence on the presence of bound Cl⁻ in PSII. Electron paramagnetic resonance study of manganese (Mn) release per reaction center/Y_D⁺ showed that there was little loss of Mn²⁺ up to 42°C in our preparations, although the PSII activity was significantly lowered. These observations together with data from steady state chlorophyll a fluorescence imply that the site of action of Cl⁻ causing direct activation of oxygen evolution was different from the site of primary heat damage. A differential response of chloride binding sites to heat stress was observed. The high-affinity (tightly bound, slow exchanging) site of chloride is affected earlier (∼37°C) while low-affinity (loosely bound, fast exchanging) site gets affected at higher temperatures (42.5°C in thylakoids and 40°C in the case of PSII-enriched membranes). Prasanna Mohanty is an INSA Honorary Scientist and Professor on Courtesy, DAVV, Indore.     

The use of13C/12C isotope abundance ratio for characterization of the origin of ethyl alcohol

The carbon isotope composition of ethyl alcohol produced during alcohol fermentation depended on the substrate used and was characterized by the value of δ¹³C equal to −24.7 ± 0.8%. (wheat grain), −22 ± 0.1%. (rye grain), −22 ± 0.5%. (products of wood hydrolysis), −15.3 ±0.3%. (maize grain) and −10 ± 0.1%. (sugar cane). The isotope composition of carbon of ethyl alcohol obtained during catalytic hydroxylation of ethylene has a δ¹³C of −30.6 ± 0.3%.. The possibility of quantitative determination of specific components in mixtures of ethanol samples with various isotope compositions (chemical synthesis and alcohol fermentation of raw material from C₃ or C₄ plants) was shown.     

Visualization of plasma-induced processes by a projection system with a Cu-laser-based brightness amplifier

A novel method for visualization of the process of interaction of high-power energy fluxes with various surfaces is proposed. The possibility of the dynamic visualization of a surface covered with a ∼3-cm-thick plasma layer with a linear density of ∼10¹⁶ cm⁻² is demonstrated experimentally. A scheme of intracavity shadowgraphy of phase objects with the use of a laser projection microscope is developed. Shadow images illustrating the development of the plasma torch of an erosion capillary discharge in air are presented.     

Endogenous lithium and boron red cell-plasma ratios: normal subjects versus bipolar patients not on lithium therapy

This study was undertaken to compare endogenous lithium concentrations in human blood and its components from normal donors versus bipolar patients. The patients were not on lithium therapy at the time that the blood samples were donated and had not received any lithium therapy for at least 2 yr. Blood components were separated by centrifugation. The analytical method for lithium as developed in this laboratory consists of thermal-neutron activation of freeze-dried samples. 3H is produced via the reaction 6Li + n = 3H + 4He, and high-sensitivity rare gas mass spectrometry is used to measure 3He formed from beta-decay of 3H. Boron measurements are made concurrently using 4He from the reaction 10B + n = 4He + 7Li. Seven normal donors and seven patients with a diagnosis of bipolar disorder participated in this study. Measurements of lithium and boron were made in whole blood, plasma, and red cells. Red cell-plasma ratios R(Li) and R(B) were calculated after corrections were made for trapped plasma in the red cells. The results show that bipolar patients may have higher concentrations of lithium in blood, plasma, and red cells (p = 0.08, 0.02, and 0.02, respectively) and may have higher R(Li) values than normal donors (p = 0.01). No evidence was found for bipolar-normal differences in these four parameters for boron. Although our sample size is admittedly very small, the results clearly show that the endogenous red cell ratio R(Li) and plasma or red cell lithium concentrations may become useful diagnostic indicators for bipolar illness if the analytical methods are further developed.     

Study of the glow dynamics in a laser-produced plasma jet expanding across the magnetic field

Results are presented from experimental studies of the glow dynamics of a plasma jet generated during the irradiation of a plane aluminum target by an iodine laser pulse with the wavelength 1.315 μm. The laser pulse energy was 330–480 J, the pulse duration was 0.5 ns, and the focal spot diameter was 3 mm, the laser intensity on the target surface being ∼10¹³ W/cm². The jet expanded across an external magnetic field with the strength ∼1 kOe. The residual air pressure in the vacuum chamber was ∼10⁻⁵ Torr. The spatiotemporal behavior of the jet glow was investigated using a nine-frame camera in two mutually perpendicular directions (along and across the magnetic field). The results of measurements indicate azimuthal asymmetry of the jet expansion.     

Concentrations and fluxes of dissolved organic carbon in an age-sequence of white pine forests in Southern Ontario,Canada

We determined concentrations and fluxes of dissolved organic carbon (DOC) in precipitation, throughfall, forest floor and mineral soil leachates from June 2004 to May 2006 across an age-sequence (2-, 15-, 30-, and 65-year-old) of white pine (Pinus strobus L.) forests in southern Ontario, Canada. Mean DOC concentration in precipitation, throughfall, leachates of forest floor, Ah-horizon, and of mineral soil at 1 m depth ranged from ∼2 to 7, 9 to 18, 32 to 88, 20 to 66, and 2 to 3 mg DOC L⁻¹, respectively, for all four stands from April (after snowmelt) through December. DOC concentration in forest floor leachates was highest in early summer and positively correlated to stand age, aboveground biomass and forest floor carbon pools. DOC fluxes via precipitation, throughfall, and leaching through forest floor and Ah-horizon between were in the range of ∼1 to 2, 2 to 4, 0.5 to 3.5, and 0.1 to 2 g DOC m⁻², respectively. DOC export from the forest ecosystem during that period through infiltration and groundwater discharge was estimated as ∼7, 4, 3, and 2 g DOC m⁻² for the 2-, 15-, 30-, and 65-year-old sites, respectively, indicating a decrease with increasing stand age. Laboratory DOC sorption studies showed that the null-point DOC concentration fell from values of 15 to 60 mg DOC L⁻¹ at 0 to 5 cm to <15 mg DOC L⁻¹ at 50 cm. Specific ultraviolet light absorption at 254 nm (SUVA₂₅₄) increased from precipitation and throughfall to a maximum in forest floor and decreased with mineral soil depth. No age-related pattern was observed for SUVA₂₅₄ values. DOC concentration in forest floor soil solutions showed a positive exponential relationship with soil temperature, and a negative exponential relationship with soil moisture at all four sites. Understanding the changes and controls of DOC concentrations, chemistry, and fluxes at various stages of forest stand development is necessary to estimate and predict DOC dynamics on a regional landscape level and to evaluate the effect of land-use change.     

<Emphasis Type="Italic">Neurospora crassa</Emphasis> FKS Protein Binds to the (1,3)β-Glucan Synthase Substrate,UDP-Glucose

The essential fungal cell-wall polymer (1,3)β-glucan is synthesized by the enzyme (1,3)β-glucan synthase. This enzyme, which is the target of the echinocandin and pneumocandin families of fungicidal antibiotics, is a complex composed of at least two proteins, Rho1p and Fks1p. Homologs of the yeast FKS1 gene have been discovered in numerous fungi, and existing evidence points to, but has not yet proved, Fks1p being the catalytic subunit of (1,3)β-glucan synthase. We have purified (1,3)β-glucan synthase from Neurospora crassa ∼400-fold enrichment and labeled the substrate-binding protein by using a UDP-glucose analog, 5-azido-[β-³²P]-UDP-glucose. UDP-glucose-binding proteins were photo-crosslinked to the substrate analog and identified from SDS-PAGE gels by Quadrupole time-of-flight mass spectrometry by sequencing the tryptic peptides. Two plasma membrane proteins were labeled FKS and H⁺-ATPase. These results suggest that FKS appears to be the substrate-binding subunit of (1,3)β-glucan synthase. Received: 31 May 2002 / Accepted: 27 July 2002     

Hydrologic Variability of Small, Northern Michigan Lakes Measured by the Addition of Tracers

The hydraulic residence time (or flushing rate of water) is a key variable for any aquatic ecosystem and is used in many types of models and calculations. Rather than being measured directly, the hydraulic residence time is usually inferred from estimates of watershed size, precipitation, and water yield. Such estimates can be problematic in any environment but are especially so in environments in which flat or complex topography makes delineations of mapped watershed boundaries difficult to discern. We added lithium bromide, (LiBr) to three small seepage lakes in the flat topography of the Upper Peninsula of Michigan to provide an independent estimate of the water residence time. Water residence time [volume/(outflow + evaporation)] averaged 921 ± 381 (SD) days among lakes and years and ranged from 400 to 1661 days at the extremes. This variation was not clearly related to year-to-year variation in precipitation, which was relatively constant [0.26 ± 0.06 (SD) cm day (d)^{− 1}]. The addition of the tracer (along with measurements of lake volume) enabled us to estimate, independent from other hydrologic information, the flow of water leaving the lakes in seepage plus surface outflow. This value, in conjunction with measurement of precipitation and evaporation, enabled us to calculate complete water budgets for these lakes. Among lakes and years, the groundwater input averaged 0.48 ± 0.36 cm d^{− 1} and accounted for 57%± 19% of total water input. This estimate was larger by 150% than that obtained by multiplying precipitation (minus estimated evapotranspiration) times a mapped value of the watershed areas. Our analysis enables us to calculate the relative significance of groundwater and precipitation for solutes such as phosphorus, hydrogen ion, and dissolved organic carbon. Received 17 February 1998; accepted 19 February 1998.     

Home range and habitat use of male Reeves’s pheasant (Syrmaticus reevesii) during winter in Dongzhai National Nature Reserve, Henan Province, China

Home range and habitat use of male Reeves’s pheasant (Syrmaticus reevesii) were studied during winter of 2001∼2002 and 2002∼2003 in the Dongzhai National Nature Reserve, Henan Province. Results from five individuals of Reeves’s pheasant with over 30 relocations, indicated that the average size of home range was 10.03 ± 1.17 hm² by Minimum Convex Polygon method, 8.60 ± 0.35 hm² by 90% Harmonic Mean Transformation method, and 9.50 ± 1.90 hm² by 95% Fixed Kernel method. It was observed that the winter range is smaller than that in the breeding season. The mean core area of the home range was found to be 1.88 ± 0.37 hm². Although the habitat composition of the core area varied greatly for individuals, a large part of the habitats used were composed of confier and broadleaf mixed forests, masson pine forests, fir forests, and shrubs. Habitat use within the study area was non-random, while habitats within home ranges were randomly used. Habitat use was dictated by tree diameter at breast height, shrub height and coverage at 2.0 m. The proximity between forests and shrubs were also found to be important in providing refuge for the birds during winter. Recommendations for conservation management include protecting the existing habitats in Dongzhai National Nature Reserve, increasing suitable habitat for Reeves’s Pheasant through artificial plantations (e.g. firs), and restoring some parts of the large shrub area into forests. __________ Translated from Biodiversity Science, 2005, 13 (5) [译自: 生物多样性, 2005,13(5)]     

Evidence for Multidrug Resistance-1 P-Glycoprotein-dependent Regulation of Cellular ATP Permeability

The mechanisms responsible for regulating epithelial ATP permeability and purinergic signaling are not well defined. Based on the observations that members of the ATP-binding cassette (ABC)¹ family of proteins may contribute to ATP release, the purpose of these studies was to assess whether multidrug resistance-1 (MDR1) proteins are involved in ATP release from HTC hepatoma cells. Using a bioluminescence assay to detect extracellular ATP, increases in cell volume increased ATP release ∼3-fold. The MDR1 inhibitors cyclosporine A (10 μm) and verapramil (10 μm) inhibited ATP release by 69% and 62%, respectively (p < 0.001). Similarly, in whole-cell patch-clamp recordings, intracellular dialysis with C219 antibodies to inhibit MDR1 decreased ATP-dependent volume-sensitive Cl⁻ current density from −33.1 ± 12.5 pA/pF to −2.0 ± 0.3 pA/pF (−80 mV, p≤ 0.02). In contrast, overexpression of MDR1 in NIH 3T3 cells increased ATP release rates. Inhibition of ATP release by Gd³⁺ had no effect on transport of the MDR1 substrate rhodamine-123; and alteration of MDR1-substrate selectivity by mutation of G185 to V185 had no effect on ATP release. Since the effects of P-glycoproteins on ATP release can be dissociated from P-glycoprotein substrate transport, MDR1 is not likely to function as an ATP channel, but instead serves as a potent regulator of other cellular ATP transport pathways. Received: 20 November 2000/Revised: 25 May 2001     

Runaway electron beams in the gas discharge for UV nitrogen laser excitation

The review of the methods for obtaining the runaway electron beams in the gas discharge is performed. The new method is offered, using which the beam is first formed in a narrow gap (∼1 mm) between the cathode and the grid and then it is accelerated by the field of the plasma column of the anomalous self-sustained discharge in the main gap (10–20 mm long). The electron beams with an energy of about 10 keV and current density of 10³ A/cm² at a molecular nitrogen pressure of up to 100 Torr have been obtained experimentally. The results of research of the UV nitrogen laser with an excitation via runaway electron beam and radiation of energy of ∼1 mJ are given. The UV nitrogen laser generation with the energy of ∼1 mJ has been obtained by the runaway electron beams.     

Magnesium and methionine deprivation affect the response of rats to boron deprivation

A series of nine experiments were done to obtain further evidence that boron might be involved in major mineral metabolism (Ca, P, and Mg), thus indicating that boron is an essential nutrient for animals. Eight factorially arranged experiments of 6–10 wk durations were done with weanling Sprague-Dawley male rats. One factorially arranged experiment was done with weanling spontaneously hypertensive rats. The variables in each experiment were dietary boron supplements of 0 and 3 μg/g, and dietary magnesium supplements of either 200 (Experiments 1–3) or 100 (Experiments 4–9) and 400 μg/g. In Experiments 7 and 9, a third variable was dietary manganese supplements of 25 and 50 μg/g. Methionine status was varied throughout the series of experiments by supplementing the casein-based diet with methionine and arginine. Findings were obtained indicating that the severity of magnesium deprivation and the methionine status of the rat strongly influence the extent and nature of the interaction between magnesium and boron, and the response to boron deprivation. When magnesium deprivation was severe enough to cause typical signs of deficiency, a significant interaction between boron and magnesium was found. Generally, the interaction was characterized by the deprivation of one of the elements making the deficiency signs of the other more marked. The interaction was most evident when the diet was not supplemented with methionine and especially when the diet contained luxuriant arginine. Signs of boron deprivation were also more marked and consistent when the diet contained marginal methionine and luxuriant arginine. Among the signs of boron deprivation exhibited by rats fed marginal methionine were depressed growth and bone magnesium concentration, and elevated spleen wt/body wt and kidney wt/body wt ratios. Because the boron supplement of 3 μg/g did not make the dietary intake of this element unusual, it seems likely that the response of the rats to dietary boron in the present study were manifestations of physiological, not pharmacological, actions, and support the hypothesis that boron is an essential nutrient for the rat. Mentions of a trademark or proprietary product does not consitute a guarantee or warranty of the product by the US Department of Agriculture and does not imply its approval to the exclusion of other products that may also be suitable.     

The effect of different levels of the B800-850 light-harvesting complex on intracytoplasmic membrane development in Rhodobacter sphaeroides

A role for the peripheral (B800-850) light-harvesting complex in vesicularization of the Rhodobacter sphaeroides intracytoplasmic membrane (ICM), suggested from studies in mutant strains lacking one or more of the pigment-protein complexes, was examined further in the wild-type strain NCIB 8253 grown at high (∼1000 W m^–2), moderate (∼300 W m^–2), and low (∼100 W m^–2) light intensities. The resulting ICM vesicles (chromatophores) had B800-850 levels related inversely to irradiance and banded in rate-zone sedimentation at ∼1.10, 1.09, and 1.07 g ml^–1, respectively. Equilibrium centrifugation on iso-osmotic gradients indicated that this distinct sedimentation behavior resulted solely from differences in hydrodynamic radii. These size differences were confirmed by gel-exclusion chromatography and in electron micrographs of thin-sectioned cells. A pulse-chase study of ICM growth following a tenfold reduction in light intensity showed a relatively slow equilibration of membrane proteins during adaptation, and that new protein was incorporated largely into additional ICM formed at the lowered illumination level, giving rise to chromatophores of reduced size and elevated B800-850 content. These results provide further evidence for a model in which the B800-850 complex both drives development of vesicular ICM in Rba. sphaeroides and determines the size of resulting vesicles. Received: 12 October 1995 / Accepted: 21 December 1995     

DomSVR: domain boundary prediction with support vector regression from sequence information alone

Protein domains are structural and fundamental functional units of proteins. The information of protein domain boundaries is helpful in understanding the evolution, structures and functions of proteins, and also plays an important role in protein classification. In this paper, we propose a support vector regression-based method to address the problem of protein domain boundary identification based on novel input profiles extracted from AAindex database. As a result, our method achieves an average sensitivity of ∼36.5% and an average specificity of ∼81% for multi-domain protein chains, which is overall better than the performance of published approaches to identify domain boundary. As our method used sequence information alone, our method is simpler and faster.