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PubMed2026

Adding Rib Mobilization to Diaphragm Release Techniques in Patients With Non-Specific Neck Pain: Randomized Controlled Trial.

BACKGROUND: Non-specific neck pain (NSNP) is a frequent issue that can negatively affect both mobility and function. Recently, there has been growing interest in newer therapeutic approaches, including rib mobilization and diaphragm release techniques, as potential ways to address NSNP and support better outcomes for those affected. PURPOSE: To find out the immediate effects of how (DRT) combined with (RMT) affects the level of pain and the extent to which patients' functional abilities are improved in cases of NSNP. METHODS: For this prospective RCT, 96 participants aged 20 to 45 years were randomly assigned to one of three equal groups based on their pain score (VAS). Group B engaged in (DRT) for 40 minutes, three times weekly for 8 weeks, in contrast to Group A, which got both RMT combined with DRT. Group C (active control) received advice and some exercises. Measurements were collected before and after the intervention; the primary outcomes included pain severity, evaluated using a visual analog scale (VAS); active neck range of motion (ROM), measured with a cervical range of motion (CROM) device; and neck flexion endurance. Additionally, the secondary outcome of neck-related disability was assessed using the Neck Disability Index (NDI). RESULTS: No statistically significant difference was identified among the three groups at baseline; nevertheless, a treatment effect emerged after 8 weeks (p = 0.001 and f-value = 4.15, ƞ2 = 0.306). A statistically significant time-treatment interaction was seen when comparing the pre- and post-treatment periods in groups A and B (p = 0.001, f-value = 3.16, ƞ2 = 0.251). CONCLUSION: The addition of rib mobilization to diaphragm release techniques in patients with non-specific neck pain resulted in statistically significant improvements in pain intensity, cervical flexion, right lateral rotation, left lateral rotation, right rotation, and neck flexor endurance, with moderate to large effect sizes for pain reduction and cervical motion. However, no statistically significant differences were observed between groups for cervical extension, left rotation, or the Neck Disability Index (NDI), and only a marginal clinical improvement in NDI was noted in Group A. The observed benefits in the combined intervention group may not be attributable solely to rib mobilization. The increased treatment complexity and greater therapist interaction inherent in the combined approach could also have influenced the outcomes. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT07133646.

Humans↗
PubMed1982

Drugs affecting the tetrodotoxin-sensitive ("fast") sodium mechanism in the cardiac cell membrane.

Prostacyclin, a newer member of the prostaglandin family, has been shown to stimulate the fast sodium system in the heart. A stimulatory effect of celluline-A, a biological Ca complex obtained from frog skin, has been demonstrated on both the fast and slow depolarization mechanisms. Prostacyclin and celluline-A are capable of restoring the electrical excitability of the isolated cat auricle poisoned with 3.5 mM MnCl2, i.e., in a situation when epinephrine is ineffective. We conclude that the normal cardiac cell membrane is tuned in such a way that the contribution of both the fast and slow depolarization mechanisms is necessary to generate an action potential, which is the result of their synergistic action. But both of them have remarkable reserve capacity which can be mobilized by their respective stimulators. With this reserve capacity mobilized, either of the two mechanisms can generate an action potential on its own, without the contribution of the other. Epinephrine can mobilize the reserve capacity of the slow mechanism, and prostacyclin that of the fast one. Celluline-A is a potent stimulator of both depolarization mechanisms.

Animals↗
PubMed2005

Augmented mobilization and collection of CD34+ hematopoietic cells from normal human volunteers stimulated with granulocyte-colony-stimulating factor by single-dose administration of AMD3100, a CXCR4 antagonist.

BACKGROUND: AMD3100, a selective antagonist of CXCR4, rapidly mobilizes CD34+ hematopoietic progenitor cells (HPCs) from marrow to peripheral blood with minimal side effects. STUDY DESIGN AND METHODS: To further investigate potential clinical utility of AMD3100 for CD34+ cell mobilization and collection, a Phase I study in normal volunteers was performed examining single-dose administration of AMD3100 alone and in combination with a standard 5-day granulocyte-colony-stimulating factor (G-CSF) regimen. RESULTS: AMD3100 (160 microg/kg x 1 on Day 5) significantly increased both G-CSF-stimulated (10 microg/kg/day) mobilization of CD34+ cells (3.8-fold) and leukapheresis yield of CD34+ cells. Moreover, collection of CD34+ cells was comparable between individuals mobilized by a single-dose regimen of AMD3100 (240 microg/kg) and individuals mobilized with a 5-day regimen of G-CSF. AMD3100-mobilized leukapheresis products contained significantly greater numbers of T and B cells compared to G-CSF-stimulated leukapheresis products. CONCLUSION: These findings indicate that AMD3100 can be used alone or as an adjunct to G-CSF to mobilize cells for HPC transplantation.

Anti-HIV Agents↗
PubMed1992

Synergism between cAMP and ATP in signal transduction in cardiac myocytes.

ATP transiently increases the intracellular Ca2+ concentration in cardiac myocyte suspensions. Pretreatment with norepinephrine (NE) greatly potentiates the ATP response. We performed experiments on adult rat myocyte suspensions loaded with fura-2 to investigate the mechanism of NE potentiation. We found that forskolin (an activator of adenylate cyclase), 3-isobutyl-1-methylxanthine (an inhibitor of phosphodiesterase), and permeative adenosine 3',5'-cyclic monophosphate (cAMP) analogues potentiate the increase in cytosolic Ca2+ concentration induced by ATP. NE, forskolin, and 8-(4-chlorophenylthio)-cAMP all increase Vmax of the Ca2+ response curve of ATP. Measurement of cAMP by radioimmunoassay confirmed that the changes in the ATP response were accompanied by an increase in cAMP. These results suggest that the noradrenergic potentiation of the ATP-induced Ca2+ mobilization involves cAMP as a second messenger. Patch-clamp studies of isolated myocytes showed that neither NE nor forskolin alters the inward current elicited by ATP, but rather they increase the duration of secondary slow action potentials elicited by ATP. NE also increases the Ca2+ current through L-type Ca2+ channels in the myocytes. We conclude that NE potentiates the ATP-induced Ca2+ transient by increasing cAMP levels and that one of the early events is the increase of the inward Ca2+ current during the action potential.

Adenosine Triphosphate↗
PubMedDate not supplied

Venous pressure dynamics of the healthy human leg. Role of muscle activity, joint mobility and anthropometric factors.

The delicate interplay between the muscle-joint unit and intact venous valves is mandatory for normal venous blood return from the human leg. We have investigated the potential role of (1) muscle activity and joint mobility, and (2) anthropometric factors for peripheral venous pressure physiology. 20 healthy young subjects (10 males, 10 females; mean age: 25.6 +/- 3.1 years) underwent direct venous blood pressure measurements during walking on a treadmill in 12 experimental conditions (duration, 1 min each): these resulted from a combination of two different walking velocities, two different degrees of ascent, and three different walking conditions. Anthropometric parameters (e.g., body height, weight and calf circumference) were also measured in all subjects. Outcome measures were the pressures (mm Hg) during quiet standing (resting pressure, P(0)), the maximal activity-induced pressure reduction (Delta P(max)), i.e., the difference between the resting pressure (P(0)) and minimal pressure during exercise (P(min)), the times (s) to minimal pressure during exercise (T(Pmin)) and to half-maximal recovery of P(0) after exercise (T(max1/2)). We found that the maximal venous pressure reduction (Delta P(max)) during walking increased at the higher walking speed and decreased with restricted joint mobility (p = 0.0001). Taller and heavier subjects, or subjects with a greater calf circumference had higher P(0) (p = 0.0001), showed greater Delta P(max) (p < 0.010), and took longer to achieve minimal pressure during exercise (T(Pmin); p < 0.010) than their corresponding counterparts. Females had lower levels of P(0) (p = 0.0001), but not of Delta P(max), and shorter T(Pmin) (p = 0.0076) than males. These gender effects largely result from differences in body height, weight, and calf circumference (p = 0.0001 for the appropriate ANOVA interaction terms). We conclude that during walking, a higher degree of muscle activity and a greater muscle mass enhance venous emptying of the healthy human leg. Conversely, impairments of joint mobility reduce the efficacy of the muscle-vein pump. Moreover, body height and weight significantly influence venous pressure physiology under both resting and activity-related conditions. These anthropometric factors also largely explain sex differences in peripheral venous hemodynamics.

Adult↗
PubMed1976

Resting and stimulated values of model parameters governing transmitter release at a synapse in Aplysia californica.

Transmitter release (R) at a synpase in Aplysia californica can be analyzed in terms of a model with the following parameters: A, the available pool of transmitter; F, the fraction of available pool released by a presynaptic action potential; M, the rate of transmitter mobilization into the available pool; D, the rate constant of demobilization of transmitter from the available pool. In the present paper we show that: (1) beginning with an analysis of the recovery from depression of the second of a pair of disolated EPSPs separated by a series of intervals of about 10-60 sec, and assuming that the recovery is due to refilling of a depleted A, it is possible to estimate resting equilibrium values of these parameters; (2) changes in these parameters when a new equilbrium state is reached after prolonged stimulation (e.g., 300 stimuli at 1/sec) can then be quantitatively determined; (3) the increased rate of transmitter release observed during and after repetitive stimulation is the consequence of increases in F and M with changes in A passively following; and (4) there are significant correlations among certain resting parameters and between the values of certain resting parameters and these parameters upon stimulation. Preparations with a large resting F tend to have a relatively small resting A. Preparations with a large resting F or M tend to increase these less with stimulation than preparations with smaller resting values of these parameters. Preparations with large stimulus-dependent increases in F tend to have large stimulus-dependent increases in M.

Animals↗
PubMed2005

The electrokinetic properties of latex particles: comparison of electrophoresis and dielectrophoresis.

A comprehensive study of the AC and DC electrokinetic properties of submicrometre latex particles as a function of particle size and suspending medium conductivity and viscosity is presented. Electrophoretic mobility and dielectrophoretic cross-over results were measured for particle diameters ranging from 44 to 2000 nm. The zeta potentials of the particles were calculated from the electrophoretic mobility data for different suspending medium conductivities, using various models, with and without the inclusion of surface conduction. The dielectrophoretic data was analysed to derive values for the Stern layer conductance and zeta potentials.

Journal Article↗
PubMed2000

Modeling the influence of settlement structure on the spread of influenza among communities.

Several factors play critical roles in the geographic spread of infectious diseases, including the movement of people between communities and the social and economic structure of groups of communities. A mathematical model has been developed to examine the individual and shared impact of these factors. This model was applied to the spread of the 1918-1919 influenza epidemic in three Aboriginal communities in central Canada. Previously published results from simulations of the model used parameter estimates for mobility patterns that were derived from historical documents from the study communities, especially Hudson's Bay Company post journals. We have termed this model the Frontier pattern. In this paper we extend that work to consider the consequences of three additional travel scenarios, which represent idealized trade and travel relationships between different communities. The three patterns include (a) the Central Marketplace scenario, an idealization of relations between a central community and its satellites in which a single central community satisfies all needs of the satellite communities; (b) the Sister Towns scenario, which allows travel among all communities and overemphasizes communication between satellites so that the ramifications of small town interactions are easier to observe; and (c) the Circuit scenario, which represents a hypothetical trade network that is a series of unidirectional dyad relationships linking all communities within a region. Results from simulations of the four mobility patterns are compared to assess the potential impact different social and economic relationships among communities may have had on the geographic spread of the 1918 influenza epidemic in central Canada and in other regions. These results reinforce conclusions that show that variation in patterns of mobility significantly influences the timing of epidemic peaks but only minimally alters the number of cases within a community. In addition, comparisons of the different models indicate that a central location in the social and political hierarchy of a region may be more important in influencing patterns of epidemic spread than just a central location with regard to travel patterns. Furthermore, who was actually travelling and where they were travelling had important consequences for epidemic spread. Am. J. Hum. Biol. 12:736-748, 2000. Copyright 2000 Wiley-Liss, Inc.

Journal Article↗
PubMed1999

Electrokinetic Phenomena in Homogeneous Cylindrical Pores.

The electrokinetic phenomena occurring in homogeneous cylindrical pores containing symmetric electrolytes are studied. The local relations for flow in the pores (Nernst-Planck and Navier-Stokes equations) are developed. The analysis includes a numerical solution of the nonlinear Poisson-Boltzmann equation. The integral expressions of the phenomenological coefficients coupling the solvent flow and the electrical current with the hydrostatic pressure and the electrical potential gradients are established and calculated numerically. The mobilities of anions and cations are individually specified and the electroviscous effects as well as the surface conductance are taken into account. Streaming potentials obtained from numerical calculations are compared with results given by classical relations in a range of zeta potentials and electrokinetic radii that may commonly occur in experimental investigation of micro- and ultrafiltration membranes. In this work, it is shown that classical approximated relations can give rise to very misleading conclusions and that the determination of the true zeta potential requires a full analysis (including numerical calculations) of the basic relations for flow and potential distribution in charged pores. Copyright 1999 Academic Press.

Journal Article↗
PubMed1995

Harvesting and enrichment of hematopoietic progenitor cells mobilized into the peripheral blood of normal donors by granulocyte-macrophage colony-stimulating factor (GM-CSF) or G-CSF: potential role in allogeneic marrow transplantation.

To explore the use of stem/progenitor cells from peripheral blood (PB) for allogeneic transplantation, we have studied the mobilization of progenitor cells in normal donors by growth factors. Normal subjects were administered either granulocyte-macrophage colony-stimulating factor (GM-CSF) at 10 micrograms/kg/d, or G-CSF at 10 micrograms/kg/d, or a combination of G- and GM-CSF at 5 micrograms/kg/d each, administered subcutaneously for 4 days, followed by leukapheresis on day 5. Mononuclear cells expressing CD34 (CD34+ cells) were selectively enriched by affinity labeling using Dynal paramagnetic microspheres (Baxter Isolex; Baxter Healthcare Corp, Santa Ana, CA). The baseline CD34+ cells in peripheral blood before mobilization was 0.07% +/- 0.05% (1.6 +/- 0.7/microL; n = 18). On the fifth day after stimulation (24 hours after the fourth dose), the CD34+ cells were 0.99% +/- 0.40% (61 +/- 14/microL) for the 8 subjects treated with G-CSF, 0.25% +/- 0.25% (3 +/- 3/microL, both P < .01 v G-CSF) for the 5 subjects administered GM-CSF, and for the 5 subjects treated with G- and GM-CSF, 0.65% +/- 0.28% (41 +/- 18/microL, P < .5 v GM-CSF). Parallel to this increase in CD34+ cells, clonogenic assays showed a corresponding increase in CFU-GM and BFU-E. The total number of CD34+ cells collected from the G-CSF group during a 3-hour apheresis was 119 +/- 65 x 10(6) and was not significantly different from that collected from the group treated with G- and GM-CSF (101 +/- 35 x 10(6) cells), but both were greater than that from the group treated with GM-CSF (12.6 +/- 6.1 x 10(6); P < .01 for both comparisons). Analysis of the CD34+ subsets showed that a significantly higher percentage of cells with the CD34+/CD38- phenotype is found after mobilization with G- and GM-CSF. In the G-CSF group, immunomagnetic selection of CD34+ cells permitted the enrichment of the CD34+ cells in the apheresis product to 81% +/- 11%, with a 48% +/- 12% yield and to a purity of 77% +/- 21% with a 51% +/- 15% recovery in the G- and GM-CSF group. T cells were depleted from a mean of 4.5 +/- 2.0 x 10(9) to 4.3 +/- 5.2 x 10(6) after selection, representing 99.9% depletion. We conclude that it is feasible to collect sufficient numbers of PB progenitor cells from normal donors with one to two leukapheresis procedures for allogeneic transplantation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed2001

Local vasodilator response to mobile phones.

OBJECTIVES: The use of mobile phones with the resulting generation of potentially harmful electromagnetic fields (EMF) is the focus of public interest. Heat generation and the activation of the inducible form of nitric oxide (NO) synthase may be possible causes of the biological effects of EMF exposure. We investigated if a mobile telephone conversation can modify skin temperature, NO, and nasal resistance. METHODS: We studied the effect of an EMF (900 MHz) generated by a commercially available cellular phone during a 30-minute telephone conversation on skin temperature, nasal NO measured by chemiluminescence, and nasal minimal cross-sectional area (MCA) measured by rhinometry. Eleven normal subjects (mean age +/- standard error of mean [SEM], 32 +/- 5 y; 10 male) were studied. RESULTS: There was a similar and significant increase in skin temperature of the nostril and occipital area on the same side as the telephone (maximal increase 2.3 +/- 0.2 degrees C at 6 min) as well as a tendency for higher nasal NO levels (maximal increase 12.9 +/- 4.9% at 10 min), whereas the MCA was significantly reduced (maximal decrease -27 +/- 6% at 15 min). Such changes were not recorded when an earpiece was used to avoid the direct exposure to the electromagnetic field. There were no changes in the skin temperature and nasal NO measured on the opposite side to the mobile phone, whereas the MCA was significantly increased (38 +/- 10%). CONCLUSIONS: Exposure to EMF produced by a mobile phone produces biological effects that can be easily measured. Microwaves may increase skin temperature and therefore cause vasodilation and reduce MCA. Further studies are needed to study the long-term effects of mobile phone use and the relation among NO production, vasodilation, and temperature.

Acoustics↗
PubMed2004

Training mobility tasks after stroke with combined mental and physical practice: a feasibility study.

This study examines the potential of using mental practice (MP) to promote the learning of 2 mobility tasks in persons with stroke. Twelve patients were trained with MP to increase the loading of the affected limb while standing up from a chair and sitting down. Vertical forces were recorded using force plates under each foot and the chair. Changes in the loading of the affected limb and in task duration, immediately after 1 training session and 24 h later, served as outcomes. After training, the loading of the affected limb had increased (P < 0.001) during standing up (16.2%) and sitting down (17.9%), and the improvement remained significant 24 h later, indicating a learning effect. In contrast, the duration of the performance did not change with training. The results indicate that, in the early stage of learning with MP, changes in limb-loading strategies are a more sensitive measure of performance than is speed.

Adult↗
PubMed1974

The lysosome periphery: biochemical and electrokinetic properties of the tritosome surface.

Normal rat liver lysosomes were isolated by the technique of loading with Triton WR-1339. Purity of the preparation was monitored with marker enzymes; a high enrichment in acid hydrolases was obtained in the tritosome fraction. In 0.0145 M NaCl, 4.5% sorbitol, 0.6 mM NaHCO(3), pH 7.2 at 25 degrees C the tritosomes had an electrophoretic mobility of -1.77 +/- 0.02 microm/s/V/cm, a zeta potential of 23.2 mV, a surface charge of 1970 esu/cm(2), and 33,000 electrons per particle surface assuming a tritosome diameter of 5 x 10(-7) m. Treatment of the tritosomes with 50 microg neuraminidase/mg tritosome protein lowered the electrophoretic mobility of the tritosome to -1.23 +/- 0.02 microm/s/V/cm under the same conditions and caused the release of 2.01 microg sialic acid/mg tritosome protein. Treatment of the tritosomes with hyaluronidase did not affect their electrophoretic mobility, while trypsin treatment elevated the net negative electrophoretic mobility of the tritosomes. Tritosome electrophoretic mobilities indicated a homogeneous tritosome population and varied greatly with ionic strength of the suspending media. pH vs. electrophoretic mobility curves indicated the tritosome periphery to contain an acid-dissociable group which likely represents the carboxyl group of N-acetylneuraminic acid; this was not conclusively proven, however, since the tritosomes lysed below a pH of 4 in the present system. Total tritosome carbohydrate (anthrone-positive material as glucose equivalents) was 0.19 mg/mg tritosome protein while total sialic acid was 3.8 microg (11.4 nmol)/mg tritosome protein. A tritosome "membrane" fraction was prepared by osmotic shock, homogenization, and sedimentation. Approximately 25% of the total tritosome protein was present in this fraction. Analysis by gas-liquid chromatography and amino acid analyzer showed the following carbohydrate composition of the tritosome membrane fraction (in microgram per milligram tritosome membrane protein): N-acetylneuraminic acid, 14.8 +/- 3; glucosamine, 24 +/- 3; galactosamine, 10 +/- 2; glucose, 21 +/- 2; galactose, 26 +/- 2; mannose, 31 +/- 5; fucose, 7 +/- 1; xylose, 0; and arabinose, 0. The results indicate that the tritosome periphery is characterized by external terminal sialic acid residues and an extensive complement of glycoconjugates. Essentially all the tritosome N-acetylneuraminic acid is located in the membrane and about 53% of it is neuraminidase susceptible.

Animals↗
PubMed1999

Capillary electrochromatography using a fluoropolymer as the chromatographic support material.

Fused-silica capillary columns were packed with ethylene chlorotrifluoroethylene (ECTFE) particles for use in capillary electrochromatography (CEC). Electroosmotic flow (EOF) was generated in these columns using acetonitrile-water mixtures as the mobile phase. Electroosmotic mobilities of 1.6 x 10(-4) cm2 V(-1) s(-1) (linear velocities of 1 mm s(-1)) were observed using a mobile phase without an electrolyte present. The EOF in the ECTFE-packed columns is enhanced when using trifluoroacetic acid (TFA) as a mobile phase additive; electroosmotic mobilities of 3.65 x 10(-4) cm2 (V-1) s(-1) (linear velocity of 2.5 mm s(-1)) were observed. This enhancement of EOF is attributed to dynamic coating of the ECTFE particles by TFA. Other electrolytes (i.e., Tris/Tris-HCl buffer and H3PO4) in the mobile phase did not have such an enhancement of EOF. However, a slight enhancement of EOF is observed, for example, if small quantities of TFA are added to the mobile phase containing Tris buffer. The potential of ECTFE for CEC is demonstrated by separating a mixture of amino acids.

Amino Acids↗
PubMed2026

Turnip Mosaic Virus-Based gRNA Delivery System for Plant Genome Editing.

Plant virus-based gRNA delivery systems offer a rapid alternative to stable transformation for CRISPR-mediated genome editing, but potyvirus-based platforms in Cas9-expressing plants are still underexplored. Here, we developed a turnip mosaic virus (TuMV)-based system for gRNA delivery in Cas9-expressing Nicotiana benthamiana and tested whether Csy4-mediated gRNA processing could improve editing efficiency. A TuMV construct carrying a gRNA targeting PHYTOENE DESATURASE (NbPDS) induced detectable editing in both infiltrated and systemic tissues, although editing frequencies were low. Incorporation of the bacterial endoribonuclease Csy4 increased editing efficiencies in the two NbPDS genes, raising editing in infiltrated leaves to 7.1%-13.8% for NbPDSa and 7.6%-23.0% for NbPDSb, whereas lower but reproducible editing was detectable in systemic leaves. The TuMV-Csy4 platform also supported editing of a second endogenous target, MAGNESIUM CHELATASE SUBUNIT H (NbChlH), and enabled multiplex editing of NbPDS and NbChlH regardless of guide order. Editing efficiencies were consistently higher in infiltrated leaves than in systemic leaves, and no visible photobleaching or chlorosis was observed in systemic tissues despite confirmed molecular editing. To assess the potential for heritable editing, a tRNAIle mobility element was fused to the NbPDS gRNA. Although this construct increased somatic editing, no albino progeny were recovered after screening approximately 20,000 seedlings, demonstrating that heritable editing was not achieved under these conditions or did not result in mutations in all copies of the two NbPDS genes. Together, these results establish TuMV as a platform for Cas9-based gRNA delivery and show that Csy4-mediated processing improves editing efficiency, supports multiplex targeting, and demonstrates the feasibility of potyvirus-based genome editing systems in plants.

genome editing platform↗
PubMed1999

The Electrochemistry of Nonaqueous Copper Phthalocyanine Dispersions in the Presence of a Metal Soap Surfactant: A Simple Equilibrium Site Binding Model.

The electrophoretic mobilities of copper phthalocyanine particles, dispersed in isoparaffin solutions containing zirconium octanoate, have been determined using phase-analysis light scattering. All the samples studied contained trace concentrations of water. The mobility values were converted to zeta potentials using the Hückel equation. All the systems studied exhibited a pronounced maximum in zeta potential as the zirconium octanoate concentration increased. The maximum occurred at a bulk zirconium octanoate concentration equivalent to that required for complete coverage of the particles. The zeta potential data were converted to surface charge density values through the use of the Poisson-Boltzmann equation. The latter were in the range 0.4 to 2.5 µC m-2. A simple two equation site binding theory, which considered the dissociation of zirconium octanoate and the subsequent adsorption of ions at a generic surface site, was successfully applied to the surface charge data. It is proposed that the maximum in the zeta potential and surface charge as a function of zirconium octanoate concentration was observed due to the preferential location of ZrO2+ ions at the particle surface, followed by charge neutralization with octanoate anions. It is suggested that water facilitates the dissociation process of the zirconium octanoate, although it does not directly contribute to the surface charge itself. Two plausible qualitative mechanisms are described. The first involves the presence of water at the particle-solution interface, whilst the second considers the formation of micelles in the bulk isoparaffin phase. Copyright 1999 Academic Press.

Journal Article↗
PubMedDate not supplied

Deviation of the rectosigmoid colon simulating a presacral tumor: report of a case.

The rectosigmoid colon has a potential for a great deal of mobility and variation of position. This is partially due to the wide variation in length and distal attachment of the sigmoid mesocolon. When anterior or lateral deviations of the distal sigmoid and rectum are found on barium-enema examinations, the possibility of anomalous fixation of the rectosigmoid should be considered.

Abdominal Neoplasms↗
PubMed2001

Transcriptional regulation of the nitrate reductase gene in Chlorella vulgaris: identification of regulatory elements controlling expression.

Nitrate reductase (NR), the rate-limiting and primary control point of the nitrate assimilation pathway, is regulated at transcriptional and post-transcriptional levels. To better understand how NR is regulated at the transcriptional level in Chlorella vulgaris, studies were performed to identify the factors regulating NR expression. Sequence analysis of the NR promoter identified a number of potential sites that were investigated by mobility shift assays. Of the protein-binding sites found, several., such as USF and E2F are likely involved in the basal NR gene transcription. An indirect repeat sequence with similarity to the sequence recognized by the common plant regulatory factor was identified and shown to bind a Chlorella protein in vitro. Mobility shift assays of a consensus GATA element indicated that proteins able to specifically bind this element are constitutive, regardless of the nitrogen source. Mutational analysis revealed that the GATA core is required for protein binding in vitro. Additionally, a NIT2 zinc-finger domain/glutathione S-transferase fusion protein was found to bind in a sequence-specific manner to this site. In Neurospora crassa and Aspergillus nidulans, consensus GATA elements are bound by the NIT2 protein, which has a major role in the expression of nitrogen-metabolizing genes. The ability of the GATA element to function as a nitrogen response element (NRE) was further examined by in vivo foot-printing. The protection of guanines in the GATA core and surrounding region was observed only in cells grown in the presence of nitrate. These data confirm that a single GATA element has a role in regulating the expression of NR in C. vulgaris.

Binding Sites↗