Degree Of Translocation Research Articles

Cadmium Accumulation Characteristics of Different Heat Varieties Under Cadmium Stress

In order to provide technical support for the safe utilization of heavy metal-polluted farmland, we screened wheat varieties with a low accumulation of Cd in grain via a pot experiment. For this purpose, we respectively investigated the enrichment and transport characteristics of Cd in various plant parts of 119 wheat varieties under the conditions of 1.5 mg·kg-1 (low content) and 4.0 mg·kg-1 (high content) Cd-contaminated soil and explored the correlation between the Cd content of different organs of wheat and the relationship between Cd content in soil and the uptake of Cd by wheat. The results showed that:① there were significant differences in the ability to accumulate and transport Cd in roots, stems, leaves, and grains of tested wheat varieties (P<0.05). Under the condition of low Cd content, the Cd enrichment ability of each part of the wheat plant was as follows:leaf>stem ≈root>grain; under high-content stress conditions, the Cd enrichment ability of each part of the wheat plant was:leaf>root>stem>grain; under different content conditions, the Cd transport ability of each part of the wheat plant was:leaf>stem>grain. Cd content in the wheat shoot was positively correlated with total Cd content and ion-exchangeable Cd content in soil (P<0.01) and was closely related to strong transpiration under the pot experiment. ② The correlation coefficient r of BCFCd of wheat roots, stems, leaves, and grain was -0.267 to -0.645, showing a very significant negative correlation (P<0.01), indicating that with the increase in soil Cd content, the migration and accumulation degree of Cd in wheat plant organs showed a downward trend. Moreover, the negative correlation between BCFCd and soil Cd content in stems was significantly higher than that in roots, leaves, and grains, indicating that the enrichment of Cd in wheat plants largely depended on the accumulation and transportation of stems. ③ The correlation coefficient r of Cd content between the root and stem, root and leaf, root and grain, stem and leaf, stem and grain, and leaf and grain in low-and high-content groups was 0.450-0.763, showing a very significant positive correlation (P<0.01), indicating that there was a close transport relationship among the wheat organs, and the degree of translocation from the root to stem and stem to leaf was higher than that from the stem to grain and leaf to grain. ④ Using cluster analysis and enrichment and translocation coefficient sequencing, this study screened 16 and 11 wheat varieties with low Cd accumulation under the soil cadmium content of 1.5 mg·kg-1and 4.0 mg·kg-1, respectively. Among them, Luohan 7 could be used as the optimal wheat variety with low Cd accumulation under the conditions of low-, medium-, and high-Cd content.

Effects of short-term arsenic exposure in Arabidopsis thaliana: tolerance versus toxicity responses

The metalloid arsenic (As) is highly phytotoxic, in part due to the similarity of the arsenates to phosphates, but also due to its ability to induce reactive oxygen species (ROS) formation, and in the form of arsenite directly interact with certain enzymes. Here we aimed to determine the effects of a short period of As exposure on Arabidopsis thaliana. Particular focus was given to shoot responses, which have received less attention in previous studies. A. thaliana (ecotype Col-0) plants (28-d-old) were cultivated hydroponically in the presence of 0, 27, 108, and 216 µM arsenic in the form of sodium arsenate for five days. Translocation of As from root to shoot increased with increasing As concentration in the medium and caused a reduction in growth. Photosynthesis was severely affected due to stomatal closure, increased ROS accumulation, and alterations in expression of genes involved in oxidative stress responses and As detoxification. Primary metabolism was also perturbed, suggesting both the direct inhibition of certain enzymes as well as active defensive responses. Overall the effects of As toxicity depended greatly on the degree of translocation from root to shoot and involved both direct effects on biological processes and secondary effects caused by the accumulation of ROS.

Invasion and translocation of uropathogenic Escherichia coli isolated from urosepsis and patients with community-acquired urinary tract infection.

Uropathogenic Escherichia coli (UPEC) strains are found in high numbers in the gut of patients with urinary tract infections (UTIs). We hypothesised that in hospitalised patients, UPEC strains might translocate from the gut to the blood stream and that this could be due to the presence of virulence genes (VGs) that are not commonly found in UPEC strains that cause UTI only. To test this, E. coli strains representing 75 dominant clonal groups of UPEC isolated from the blood of hospitalised patients with UTI (urosepsis) (n = 22), hospital-acquired (HA) UTI without blood infection (n = 24) and strains isolated from patients with community-acquired (CA)-UTIs (n = 29) were tested for their adhesion to, invasion and translocation through Caco-2 cells, in addition to the presence of 34 VGs associated with UPEC. Although there were no differences in the rate and degree of translocation among the groups, urosepsis and HA-UTI strains showed significantly higher abilities to adhere (P = 0.0095 and P < 0.0001 respectively) and invade Caco-2 cells than CA-UTI isolates (P = 0.0044, P = 0.0048 respectively). Urosepsis strains also carried significantly more VGs than strains isolated from patients with only UTI and/or CA-UTI isolates. In contrast, the antigen 43 allele RS218 was found more commonly among CA-UTI strains than in the other two groups. These data indicate that UPEC strains, irrespective of their source, are capable of translocating through gut epithelium. However, urosepsis and HA-UTI strains have a much better ability to interact with gut epithelia and have a greater virulence potential than CA-UPEC, which allows them to cause blood infection.

Comparison of sperm parameters and fertility between sperm cryopreserved from ejaculated semen and from the epididymis of subfertile stallions

Despite the benefits provided by seminal plasma during natural cover, its function is questionable when a biotechnology such artificial insemination is used. Studies employing spermatozoa from the cauda epididymis with or without the addition of seminal plasma showed no difference in conception rates. Furthermore, studies have reported deleterious effects of secretions from accessory glands on sperm viability and conception rate (Aurich et al., Theriogenology, 1996; 46, 791-797), especially in stallions with poor semen quality. Thus the aims of this study were: 1) compare the sperm kinetic parameters, viability and fertility of sperm recovered from the ejaculate (G1) and from the cauda epididymis (G2) of subfertile stallions (pregnancy rate<35%). For G1, one ejaculate from each of eight subfertile stallions was collected and then subjected to cryopreservation using the extender BotuCrioTM. One week after the last semen collection, the stallions underwent bilateral orchiectomy. Sperm from the cauda epididymis were harvested immediately after castration by retrograde flushing the caudal portion (G2) of the epididymis using a skim milk-based extender (BotuSemenTM). The recovered sperm were then cryopreserved using BotuCrioTM extender. The sperm samples were analyzed for kinetic parameters by computer-assisted analyses (CASAHTM-IVOS) and plasma membrane integrity (Propidium iodide, Sigma; Hoechst 33345, Sigma), acrosome integrity (FITC-PSA, Sigma; Hoechst 33345, Sigma) and degree of translocation of phosphatidylserine (Annexin-V–APC, Pharmingen; Hoechst 33345, Sigma) by flow cytometry (BD-LSRFortessa ). For analysis, straws were thawed in a 46 C water bath for 20 sec. Artificial insemination was performed in the tip of the uterine horn ipsilateral to

Potentials of Synedrella nodiflora and Sida fallax growing naturally around an abandoned railway station for phytoextraction of heavy metals

Phytoextraction is a non-destructive, cost-effective and safe alternative to conventional cleanup techniques of contaminated soils. In this study, the ability of two plants species Synedrella nodiflora and Sida fallax growing naturally around the abandoned Asafo Railway Station in Kumasi for selective extraction and accumulation of four heavy metals (Pb, Cu, Fe and Zn) were studied using Atomic Absorption Spectroscope. The degree of translocation of these metals by the plants was also calculated. High translocation indices greater than one in the case of Fe and Zn were recorded in S. nodiflora and S. fallax, respectively. However Cu and Pb examined in this study were not effectively extracted nor transported within the plants, hence these plants are excluders of Cu and Pb. The soil plant transfer coefficient for both plant species were calculated for each metal. The highest translocation coefficient value in this study for both plants was recorded for Zn. The translocation coefficient values for Pb and Cu were not significant in both plants, hence these plants can be described as Pb and Cu extruders but potential candidates for Fe bioaccumulation using phytoextraction.

Biodistribution of gold nanoparticles in mouse lung following intratracheal instillation

BackgroundThe fate of gold nanoparticles, 2, 40 and 100 nm, administered intratracheally to adult female mice was examined. The nanoparticles were traced by autometallography (AMG) at both ultrastructural and light microscopic levels. Also, the gold content was quantified by inductively coupled plasma mass spectrometry (ICP-MS) and neutron activation analysis (NAA). The liver is the major site of deposition of circulating gold nanoparticles. Therefore the degree of translocation was determined by the hepatic deposition of gold. Mice were instilled with 5 intratracheal doses of gold nanoparticles distributed over a period of 3 weeks and were killed 24 h after the last dose. One group of mice were given a single intratracheal dose and were killed after 1 h.ResultsThe instilled nanoparticles were found in lung macrophages already 1 h after a single instillation. In mice instilled treated repeatedly during 3 weeks, the load was substantial. Ultrastructurally, AMG silver enhanced gold nanoparticles were found in lysosome-/endosome-like organelles of the macrophages and analysis with AMG, ICP-MS and NAA of the liver revealed an almost total lack of translocation of nanoparticles. In mice given repeated instillations of 2 nm gold nanoparticles, 1.4‰ (by ICP-MS) to 1.9‰ (by NAA) of the instilled gold was detected in the liver. With the 40 nm gold, no gold was detected in the liver (detection level 2 ng, 0.1‰) except for one mouse in which 3‰ of the instilled gold was found in the liver. No gold was detected in any liver of mice instilled with 100 nm gold (detection level 2 ng, 0.1‰) except in a single animal with 0.39‰ of the dose in the liver.ConclusionWe found that that: (1) inert gold nanoparticles, administered intratracheally are phagocytosed by lung macrophages; (2) only a tiny fraction of the gold particles is translocated into systemic circulation. (3) The translocation rate was greatest with the 2 nm gold particles.

Three Sets of Translocation Intermediates Are Formed during the Early Stage of Protein Import into Chloroplasts

During the early stage of protein import into chloroplasts, precursor proteins synthesized in the cytosol irreversibly bind to chloroplasts to form the early translocation intermediate under stringent energy conditions. Many efforts have been made to identify the components involved in protein import by analyzing the early intermediate. However, the state of the precursor within the intermediate has not been well investigated so far. In this study, an attempt was made to evaluate the extent of translocation of the precursor by determining the state of the precursor in the early intermediate under various conditions and analyzing the fragments generated by limited proteolysis of the precursors docked to chloroplasts. Our results indicate that three different sets of early intermediate are formed based on temperature and the hydrolysis of GTP/ATP. These have been identified based on the size of proteolytic fragments of the precursor as "energy-dependent association," "insertion," and "penetration" states. These findings suggest two individual ATP-hydrolyzing steps during the early stage of protein import, one of which is temperature-sensitive. Our results also demonstrate that translocation through the outer envelope membrane is mainly dependent on internal ATP.

Prevalence of environmental Aeromonas in South East Queensland, Australia: a study of their interactions with human monolayer Caco-2 cells

To investigate the prevalence of Aeromonas in a major waterway in South East Queensland, Australia, and their interactions with a gut epithelial model using Caco-2 cells. A total of 81 Aeromonas isolates, collected from a major waterway in South East Queensland, Australia, were typed using a metabolic fingerprinting method, and tested for their adhesion to HEp-2 and Caco-2 cells and for cytotoxin production on Vero cells and Caco-2 cells. Aeromonas hydrophila had the highest (43%) and Aeromonas veronii biovar sobria had the lowest (25%) prevalence. Four patterns of adhesion were observed on both HEp-2 and Caco-2 cell lines. Representative isolates having different phenopathotypes (nine strains) together with two clinical isolates were tested for their translocation ability and for the presence of virulence genes associated with pathogenic Escherichia coli. The rate and degree of translocation across Caco-2 monolayers varied among strains and was more pronounced with LogA pattern. Translocation was associated with the adherence of strains to Caco-2 cells microvilli, followed by internalization into Caco-2 cells. Two Aer. veronii biovar sobria strains were positive for the presence of heat-labile toxin genes, with one strain also positive for Shiga-like toxin gene. Pathogenic strains of Aeromonas carrying one or more virulence characteristics are highly prevalent in the waterways studied and are capable of translocating across a human enterocyte cell model. This study indicates that Aeromonas strains carrying one or more virulence properties are prevalent in local waterways and are capable of translocating in a human enterocyte cell culture model. However, their importance in human gastrointestinal disease has yet to be verified under competitive conditions of the gut.

Characterization of protein kinase C isoforms in primary cultured cerebellar granule cells

Protein kinase C (PKC) is a family of serine/threonine kinases comprised of 10 isoforms. Although commercial antibodies are available for all 10 isoforms, the specificity of these antibodies has been questioned. We have identified immunoblot conditions in which commercially purchased PKC antibodies are specific for their respective isoform. We then used these conditions to determine that PKC isoforms α, βI, βII, δ, ε, γ, λ, θ, and ζ are present in rat primary cultured cerebellar granule cells (CGCs) 6–14 days in vitro (DIV). This PKC profile is identical to that observed in cerebellar homogenates taken from 6-, 14- and 21-day-old rats. Western blot analysis indicated that the classical and the atypical PKC isoforms were more prevalent in the cytosolic subcellular fraction compared to the particulate fraction under basal conditions. Immunoreactivity for the novel isoforms tended to be higher in the particulate fraction under basal conditions. Phorbol 12-myristate 13-acetate (PMA) treatment resulted in translocated immunoreactivity from the cytosolic to the particulate fraction for all of the classical and novel PKC isoforms, but not for the atypical isoforms. However, the degree of translocation as well as the speed of translocation varied among the isoforms. The stability of the individual isoforms after PMA-induced activation also varied among the isoforms. Differences in these parameters were dependent upon culture batches and PKC isoform groups. We have identified experimental conditions in which reproducible results can be obtained with primary cultured CGCs in the study of PKC. We discuss possible solutions for problems encountered when utilizing primary cultured neurons to study PKC-mediated signal transduction.

Factors determining the growth curve of the foliose lichen Parmelia conspersa

SUMMARYGrowth curves of the foliose lichen Parmelia conspersa (Ehrh. ex Ach.) Ach. were obtained by plotting radial growth rate (RGR, mm yr‐1) of the fastest measured lobe, the slowest measured lobe, a randomly selected lobe, and by averaging a sample of lobes from each thallus against thallus diameter. Growth curves derived from the fastest‐growing lobe and by averaging lobes were asymptotic and could be fitted by the growth model of Aplin and Hill. Mean lobe width increased with thallus size, reaching a maximum at approx. 4· cm thallus diameter. In four out of six thalli, radial growth of lobes over 4 months was positively correlated with initial lobe width or area. The RGR of isolated lobes was unaffected until the base of the lobe was removed to within 1–2 mm of the tip. The concentration (μg mg‐1 biomass) of ribitol, arabitol and mannitol was greater in the marginal lobes of large than in small thalli. These results suggested that the growth curve of P. conspera is determined by processes that occur within individual marginal lobes and can be explained by the Aplin and Hill model. Changes in lobe width and in the productive capacity of individual lobes with thallus size are likely to be more important factors than the degree of translocation within the lobe in determining the growth curve.

Possible domains responsible for intracellular targeting and insulin-dependent translocation of glucose transporter type 4.

Translocation of the type 4 glucose transporter (GLUT4) to the cell surface from an intracellular pool is the major mechanism of insulin-stimulated glucose uptake in insulin-target cells. We developed a highly sensitive and quantitative method to detect GLUT4 immunologically on the surface of intact cells, using c-myc epitope-tagged GLUT4 (GLUT4myc). We constructed c-myc epitope-tagged glucose transporter type 1 (GLUT1myc) and found that the GLUT1myc was also translocated to the cell surface of Chinese hamster ovary cells, 3T3-L1 fibroblasts and NIH 3T3 cells, in response to insulin, but the degree of translocation was less than that of GLUT4myc. Since GLUT1 and GLUT4 have different intracellular distributions and different degrees of insulin-stimulated translocation, we examined the domains of GLUT4, using c-myc epitope-tagged chimeric glucose transporters between these two isoforms. The results indicated that, (1) all the cytoplasmic N-terminal region, middle intracellular loop and cytoplasmic C-terminal region of GLUT4 have independent intracellular targeting signals, (2) these sequences for intracellular targeting of GLUT4 were not sufficient to determine GLUT4 translocation in response to insulin, and (3) the N-terminal half of GLUT4 devoid both of cytoplasmic N-terminus and of middle intracellular loop seems to be necessary for insulin-stimulated GLUT4 translocation.

Composition and diversity of intestinal coliform flora influence bacterial translocation in rats after hemorrhagic stress

Coliform bacteria are the most frequently reported bacteria to translocate after hemorrhage. We investigated the correlation between composition and diversity of the cecal coliform flora and the degree of translocation in a rat model of hemorrhagic stress. Two groups of nine rats each were bled to 60 and 50 mm Hg mean arterial blood pressure, respectively. A sham-operated group without bleeding (n = 9) and a noninstrumented group (n = 6) served as controls. From each rat, 40 coliform isolates from the cecum and up to 16 from positive mesenteric lymph node (MLN) cultures were tested with an automated biochemical fingerprinting method. The phenotypic diversity of coliforms in each cecal sample was calculated as Simpson's diversity index (DI), and similarities between bacterial types in different samples were calculated as population similarity coefficients. Three rats in the sham-operated group and seven in each of the bled groups showed bacterial translocation. Of the different biochemical phenotypes (BPTs) found in the cecum of bled rats (mean, 6.5 BPTs), only a few were detected in MLNs (mean, 1.9 BPTs per MLN), with Escherichia coli being the dominant species. The translocating E. coli strains were mainly of two BPTs. Rats showing no translocation either did not carry these strains or had a high diversity of coliforms in the cecum. Furthermore, translocation of these coliform types was independent of their proportion in the cecum. In bled rats, the diversity of coliforms (mean DI, 0.53) was significantly higher than that in control groups (mean DI, 0.30; P = 0.004), suggesting that hemorrhage stimulates an increase in diversity of cecal coliforms. Rats with similar coliform flora and subjected to the same treatment showed similar patterns of translocation. Our results suggest that the composition of the coliform flora is an important factor in translocation and that certain coliform strains have the ability to translocate and survive in MLNs more easily than others.

IFN-γ Decreases Translocation and Improves Survival Following Transfusion and Thermal Injury

The effects of recombinant murine interferon-γ (rmIFN-γ) on survival and host defense were studied during gut-derived sepsis that included transfusion-induced immunosuppression. Balb/c mice (n = 153) were transfused with allogeneic blood and then treated with different doses of rmIFN-γ: 10, 100, 1000, 10,000 U, or sterile saline as control once daily for 3 days. Five days after transfusion they were gavaged with 1010Escherichia coli and given a 20% TBSA burn injury. Survival was significantly higher in groups receiving 10 U compared to control and the group receiving 10,000 U (P < 0.0001 and P - 0.02, respectively). Groups receiving 100 or 1000 U also showed an improvement of survival compared to nontreated control animals (P = 0.02). The effect of rmIFN-γ on the degree of translocation and the host's ability to kill translocated organisms was also investigated. Mice were treated as described above, except they were gavaged with 111In oxine-labeled E. coli and then subjected to a 20% TBSA burn. Mesenteric lymph nodes (MLN), liver, and spleen were harvested aseptically. Less translocation to the liver was observed compared to the nontreated group (P = 0.002) to the MLNs and spleen of the group treated with 100 U rmIFN-γ compared to controls and the group treated with 10 U (P < 0.005). Animals receiving 1000 U showed fewer bacteria in the liver and spleen compared to the control group (P < 0.005). Moreover, the ability to kill translocated organisms was significantly enhanced in the liver of the animals receiving 10 or 100 U rmIFN-γ compared to all other groups (P < 0.0001). In conclusion, the study suggests that treatment with 10 and 100 U of rmIFN-γ positively affects the outcome in gut-derived sepsis, mainly by enhancing killing of translocated bacteria. The beneficial effect in animals receiving 100 or 1000 U was related to an improved gut barrier function.

Anterior translocation of the tibia at MR imaging: a secondary sign of anterior cruciate ligament tear.

The authors evaluated measurement of the degree of anterior subluxation ("translocation") of the tibia in regard to the femur as a predictor of anterior cruciate ligament (ACL) tear. Eighty-nine magnetic resonance (MR) imaging studies of patients with either an arthroscopically confirmed intact (n = 29), acutely torn (n = 27), or chronically torn (n = 33) ACL were retrospectively reviewed. The degree of translocation was measured on hard-copy images by using two methods. Buckling of the posterior cruciate ligament (PCL) was also evaluated. Anterior tibial translocation, when measured at the midsagittal plane of the lateral femoral condyle with regard to a plane parallel to the cephalocaudal axis of the image, was a relatively specific indicator of ACL disruption. Subluxation of 5 mm or more had 58% sensitivity, 93% specificity, and 69% accuracy for an ACL tear. All knees with subluxation of 7 mm or more had torn ACLs. Buckling of the PCL was less sensitive and less accurate than anterior translocation as an indicator of ACL disruption.

The degree of bacterial translocation is a determinant factor for mortality after burn injury and is improved by prostaglandin analogs.

Bacterial translocation and related mortality rates were examined in previously transfused BALB/c mice that were gavaged with 14C radioisotope-labeled Escherichia coli before inflicting a 20% full-thickness flame burn. Radionuclide counts were measured in blood obtained by retro-orbital puncture 4 hours postburn, and survival was recorded for 10 days. Radionuclide counts in the blood correlated well with both radionuclide counts and numbers of viable bacterial in the tissues. Survivors had significantly less bacterial translocation as evidenced by blood radionuclide counts compared with nonsurvivors, and there was a significant inverse correlation between the degree of translocation and the length of survival. In the next experiment, the prostaglandin E (PGE) analogs misoprostol, enisoprost, or 16,16-dimethyl PGE2 were administered to transfused animals for 3 days before burn. Prostaglandin E analogs significantly reduced bacterial translocation as measured by blood radionuclide counts 4 hours postburn and improved survival. The data demonstrate that the intensity of bacterial translocation after burn injury is significantly associated with subsequent death. Improvement of survival by PGE analogs is associated with decreased bacterial translocation.

INFLUENCE OF DISCONTINUITIES IN PARTICLE SIZE ON THE GENESIS OF TWO SOILS OF THE HONEYWOOD CATENA

Particle-size discontinuities were located in two soil profiles of the Honeywood catena. Discontinuities in the distribution of clay, Na-dithionite and NH4-oxalate extractable Fe, Al, and Mn indicated varying degrees of translocation of these elements across the established particle-size discontinuities. The particle-size discontinuities appeared to have influenced the movement and accumulation of clay and extractable Fe, Al, and Mn through their effects on the vertical movement of water within the profiles. The degree of pedogenesis within the profiles was assessed by matching soil horizon boundaries and pedogenesis breaks with the established discontinuities. It was concluded that soil development had progressed more in the Embro profile than in the Honeywood profile. Dithionite-Fe breaks appeared to be useful in identifying the lower boundaries of Ae and Bt horizons, whereas oxalate-Fe breaks appeared to be associated with the illuvial B horizons.