Significant Tissue Differences Research Articles

Experimental DVC validation of heterogeneous micro finite element models applied to subchondral trabecular bone of the humeral head.

Subchondral trabecular bone (STB) undergoes adaptive changes during osteoarthritic (OA) disease progression. These changes alter both the mineralization patterns and structure of bone and may contribute to variations in the mechanical properties. Similarly, when images are downsampled - as is often performed in micro finite element model (microFEM) generation - the morphological and mineralization patterns may further alter the mechanical properties due to partial volume effects. MicroFEMs accounting for material heterogeneity can account for these tissue variations, but no studies have validated these with robust full-field testing methods. As such, this study compared homogeneous and heterogeneous microFEMs to experimentally loaded trabecular bone cores from the humeral head combined with digital volume correlation (DVC). These microFEMs were used to compare apparent mechanical properties between normal and OA STB. Morphological and mineralization patterns between groups were also compared. There were no significant differences in tissue or bone mineral density between groups. The only significant differences in morphometric parameters were in trabecular thickness between groups. There were no significant differences in linear regression parameters between normal and OA STB apparent mechanical properties estimated using heterogeneous microFEMs with an element-wise bilinear elastic-plastic constitutive model. Clinical significance: Validated heterogeneous microFEMs applied to STB of the humeral head have the potential to significantly improve our understanding of mechanical variations in the bone that occur during OA progression.

Striatal and cortical metabotropic glutamate 5 receptor expression and behavioral effects of the positive allosteric modulator CDPPB in a model of DYT1 dystonia

The metabotropic glutamate 5 (mGlu5) receptor is critically involved in corticostriatal plasticity which is disturbed in various animal models of dystonia. Recently, the positive allosteric modulator 3-cyano-N-(1,3-diphenyl-1H-pyrazol-5-yl)benzamide (CDPPB) exerted prodyskinetic effects in a phenotypic model of episodic dystonia. In the DYT1 knock-in (KI) mouse, a model for a persistent type of dystonia, previous ex vivo electrophysiological experiments indicated that mGlu5 receptors are involved in abnormal striatal plasticity. Therefore, in the present study we examined the mGlu5 receptor expression in the striatum and cortex of DYT1 KI mice in comparison with wildtype littermates. By immunohistochemistry (IHC) we found a lower expression of mGlu5 receptors in the cortex (16%) and ventral striatum (10%) but not in the whole striatum of DYT1 KI mice, while mRNA levels were merely lower in the striatum of DYT1 KI mice (43%). However, mGlu5 receptor protein levels measured by western blotting showed no significant differences in tissue of the whole striatum and in the cortex between both genotypes. Since DYT1 KI mice do not exhibit dystonic symptoms, we investigated if CDPPB provokes dystonia or dyskinesia. CDPPB (10, 20 and 30 mg/kg intraperitoneal, i.p.) did not induce abnormal movements and the locomotor activity did not differ between DYT1 KI and wildtype mice. The present data do not provide evidence for a crucial role of the mGlu5 receptor in the pathophysiology of DYT1 dystonia, but corticostriatal changes are in line with the hypothesis of maladaptive plasticity in dystonia.

4 The Effects of Rapid Rewarming on Tissue Salvage in Severe Frostbite Injury

Abstract Introduction Frostbite is a high morbidity, high cost injury caused by soft tissue freezing, which can lead to digit or limb necrosis requiring amputation. Many severe frostbite injuries are initially assessed at healthcare facilities outside of dedicated burn centers. Rapid rewarming is the widely accepted first line treatment and is typically performed by placing the affected body parts in a 40–42 C water bath for 15–30 minutes. The aim of this study is to ascertain the clinical practices at the referring facilities before transferring patients with severe frostbite to regional burn centers, as well as any impact on clinical outcomes. Methods Upon IRB approval, retrospective chart review identified severe frostbite patients admitted to our ABA verified burn center between 2014 and 2019. Records were reviewed to identify initial rewarming strategy from referring facilities. Time to thrombolytics after initial admission was also noted. Amputation and salvage rates were calculated. Results Seventy-four severe frostbite patients presented to outside facilities and 96 were direct admissions (N=170). There was no significant difference in age, gender, social and comorbid characteristics between transfer and direct admit groups. We found that a significantly greater number of transfer patients received tPA versus direct admit patients (82.4% v 66.7%, P=0.023). On average, tPA was given 1.5 hours earlier in the direct admit patients (5.8 vs 7.3 hours, P=0.004). There was no significant difference in tissue at risk scores (10.2 v 9.1, P=0.465), percentage of patients requiring amputation (35.1% v 24.0%, P=0.126), or tissue salvage rates (76.8 v 84.2, P=0.207) between the two groups. In the cohort of patients presenting to outside hospitals, 66% received rapid rewarming. Other warming modalities at referring centers included warm intravenous fluids, heated blankets, heated oxygen, catheter-based warming, bladder irrigation, and heat packs. On regression analysis, the use of rapid rewarming was not a significant predictor for poor outcomes for limb salvage (P=0.578). The early use of thrombolytics had a positive outcome on limb salvage (P=0.013). Conclusions Initial rewarming practices for frostbite vary dramatically at outside centers. While rapid rewarming was not statistically associated with improved outcomes, variations in specific treatment modalities and limited sample size decrease the likelihood of identifying differences in a retrospective study. Outreach efforts are needed to educate outside centers about the importance of rapid rewarming and early transfer of severe frostbite patients to burn centers for thrombolytic therapy. Applicability of Research to Practice This study shows the need for outreach and education of frostbite management for non-burn centers.

Genome-wide association analysis of potassium uptake and translocation rates under low K stress in Tibetan wild barley

A low level of available potassium (K) in soils is a major factor restricting crop growth and production. In earlier studies we found that Tibetan wild barley has a wider variation in low K stress tolerance than cultivated barley. In this study, we performed a genome-wide association analysis of 179 Tibetan wild barley (Hordeum vulgare L.) accessions exposed to low K stress and investigated the associations of K uptake rate (KUR), K translocation rate (KTR) and other K metabolism traits with 11,013 diversity arrays technology markers. The results showed that there were significant differences in tissue K concentration and content, KUR and KTR among the wild barley accessions analyzed. Scores for all traits showed a normal distribution. Three significant quantitative trait loci (QTLs) for KUR and KTR were identified and located on 6H and 1H. These QTLs were found to be associated with the cation/H(+) antiporter and cyclic nucleotide gated channel. A number of unique candidate genes associated with K-related signals, including K channels, K transporters and ethylene-related genes, were also identified. The K channels and K transporters involved in K uptake and translocation, respectively, were closely associated with KUR in response to low K stress. The present study highlights the potential of Tibetan wild barley to provide elite candidate genes for the improvement of K use efficiency of barley.

The Ability to Regulate Transmembrane Potassium Transport in Root Is Critical for Drought Tolerance in Barley.

In this work, the effect of drought on K+ uptake in root and its translocation from root to shoot was investigated using six barley genotypes contrasting in drought tolerance. Results showed that drought conditions caused significant changes in K+ uptake and translocation in a time- and genotype-specific manner, which consequently resulted in a significant difference in tissue K+ contents and drought tolerance levels between the contrasting barley genotypes. The role of K+ transporters and channels and plasma membrane (PM) H+-ATPase in barley’s adaptive response to drought stress was further investigated at the transcript level. The expression of genes conferring K+ uptake (HvHAK1, HvHAK5, HvKUP1, HvKUP2 and HvAKT1) and xylem loading (HvSKOR) in roots were all affected by drought stress in a time- and genotype-specific manner, indicating that the regulation of these K+ transporters and channels is critical for root K+ uptake and root to shoot K+ translocation in barley under drought stress. Furthermore, the barley genotypes showed a strong correlation between H+ efflux and K+ influx under drought stress, which was further confirmed by the significant up-regulation of HvHA1 and HvHA2. These results suggested an important role of plasma membrane H+-ATPase activity and/or expression in regulating the activity of K+ transporters and channels under drought stress. Taken together, it may be concluded that the genotypic difference in drought stress tolerance in barley is conferred by the difference in the ability to regulate K+ transporters and channels in root epidermis and stele.

NMR quantification of lactate production and efflux and glutamate fractional enrichment in living human prostate biopsies cultured with [1,6-13 C2 ]glucose.

Image-guided prostate biopsies are routinely acquired in the diagnosis and treatment monitoring of prostate cancer, yielding useful tissue for identifying metabolic biomarkers and therapeutic targets. We developed an optimized biopsy tissue culture protocol in combination with [1,6-13 C2 ]glucose labeling and quantitative high-resolution NMR to measure glycolysis and tricarboxcylic acid (TCA) cycle activity in freshly acquired living human prostate biopsies. We acquired 34 MRI-ultrasound fusion-guided prostate biopsies in vials on ice from 22 previously untreated patients. Within 15 min, biopsies were transferred to rotary tissue culture in 37°C prostate medium containing [1,6-13 C2 ]glucose. Following 24 h of culture, tissue lactate and glutamate pool sizes and fractional enrichments were quantified using quantitative 1 H high resolution magic angle spinning Carr-Purcell-Meiboom-Gill (CPMG) spectroscopy at 1°C with and without 13 C decoupling. Lactate effluxed from the biopsy tissue was quantified in the culture medium using quantitative solution-state high-resolution NMR. Lactate concentration in low-grade cancer (1.15 ± 0.78 nmol/mg) and benign (0.74 ± 0.15 nmol/mg) biopsies agreed with prior published measurements of snap-frozen biopsies. There was substantial fractional enrichment of [3-13 C]lactate (≈70%) and [4-13 C]glutamate (≈24%) in both low-grade cancer and benign biopsies. Although a significant difference in tissue [3-13 C]lactate fractional enrichment was not observed, lactate efflux was significantly higher (P < 0.05) in low-grade cancer biopsies (0.55 ± 0.14 nmol/min/mg) versus benign biopsies (0.31 ± 0.04 nmol/min/mg). A protocol was developed for quantification of lactate production-efflux and TCA cycle activity in single living human prostate biopsies, allowing metabolic labeling on a wide spectrum of human tissues (e.g., metastatic, post-non-surgical therapy) from patients not receiving surgery.

Comparative Transcriptome Analysis Revealed the Tissue-Specific Accumulations of Taxanes among Three Experimental Lines of Taxus yunnanensis

Taxus yunnanensis (Yew) is known for natural anticancer metabolite paclitaxel (Taxol) and its biosynthesis pathway in yew species still needs to be completely elucidated. In the current study, productions of paclitaxel and 10-DAB III from three different tissues (needle, branch, and root) of T. yunnanensis wild type (WT) and two new cultivars Zhongda-1 (Zd1) and Zhongda-2 (Zd2) were determined, and significant tissue differences in contents of the taxanes were observed among the three experimental lines. The much higher 10-DAB III and lower paclitaxel contents in needle of Zd2 when compared with that of Zd1 indicated the low conversion from 10-DAB III to paclitaxel in the needle of Zd2. In order to uncover the mechanisms of the tissue-specific biosynthesis of the taxanes, transcriptome analysis of cultivar Zd2 was conducted, and the previously reported transcriptome data of Zd1 and WT were used to perform a comparison. The enhancement of TDAT and T10βH side biosynthetic pathway in roots of Zd2 in early taxane synthesis might lead to the biosynthesis of other toxoids, while the preference of T13αH route in the needle and branch of Zd2 was mainly responsible for the tissue-specific reinforced biosynthesis of 10-DAB III and paclitaxel in Zd2. Different from Zd1, the tissue-specific pattern of paclitaxel biosynthesis genes in Zd2 was similar to WT. However, the lower transcript abundance of final steps genes (TBT, DBAT, BAPT, and DBTNBT) of the paclitaxel biosynthesis pathway in Zd2 than in Zd1 might further promote 10-DAB III accumulation in Zd2.

Protective effects of Rutin against methanol induced acute toxic optic neuropathy: an experimental study.

To determine the effects of Rutin on methanol induced optic neuropathy and compare the results with the effects of ethanol. Totally 30 rats were divided into 5 groups, with 6 rats in each group as follows: healthy controls (C), methotrexate (MTX), methotrexate+methanol (MTM), methotrexate+methanol+ethanol (MTME) and methotrexate+ methanol+Rutin (MTMR). In all rabbits except those of the control group, MTX, diluted in sterile serum physiologic, 0.3 mg/kg per oral was applied for 7d by the aid of a tube. After this procedure to the rats of MTM, MTME and MTMR groups, 20% methanol with a dose of 3 g/kg per oral was given by the aid of a tube. In MTME group, 4h after the application of methanol, 20% ethanol was applied by the same way with a dose of 0.5 g/kg. On the other hand, in MTMR group 4h after the application of methanol, Rutin, which was dissolved in distilled water, was applied by the same way with a dose of 50 mg/kg. There were statistically significant differences in tissue 8-hydroxy-2 deoxyguanine (8-OHdG), interleukin-1β (IL-1β), tumor necrosis factor-alpha (TNF-α), malondialdehyde (MDA), myeloperoxidase (MPO). glutathione peroxidase (tGSH) and superoxide dismutase (SOD) levels between groups (P<0.001). In MTMR group tissue 8-OHdG, IL-1β, MDA, and MPO levels were similar with the healthy controls but significantly different than the other groups. In histopathological evaluations, in MTX group there was moderate focal destruction, hemorrhage and decrease in number of astrocytes and oligodendrocytes; in MTM group there was severe destruction and edema with decrease in number of astrocytes and oligodendrocytes; in MTME group there was mild hemorrhage, mild edema, mildly dilated blood vessels with congestion while in MTMR group, optic nerve tissue was resembling the healthy controls. Rutin may prevent methanol-induced optic neuropathy via anti-inflammatory effects and decreasing the oxidative stress. New treatment options are warranted in this disease to avoid loss of vision in patients.

Molecular cloning and expression of peptidoglycan recognition protein (PGRPs) gene from freshwater mussel Hyriopsis cumingii

Peptidoglycan recognition proteins (PGRPs) are innate immune molecules which are structurally conserved through evolution in both invertebrate and vertebrate animals. In this paper, we reported the identification and characterization of two short (HcPGRP-S1 and HcPGRP-S2) and a long (HcPGRP-L) forms of PGRP from freshwater mussel Hyriopsis cumingii. The deduced amino acid sequences of HcPGRP-S1, HcPGRP-S2 and HcPGRP-L encoded 218, 285 and 420 amino acids, respectively, and contained the conserved PGRP domain. The multiple sequences alignment showed that the amino acids sites which could bind with Zn and maintain amidase activity were partly conserved in HcPGRP-S1 and HcPGRP-L, but highly conserved in HcPGRP-S2. Real-time quantitative PCR analysis showed that the trend of expression patterns were from high to low in hepatopancreas, gill, mantle, adductor muscle and hemocytes of H. cumingii. The highest level of expression quantity of HcPGRP-S1, HcPGRP-L and HcPGRP-S2 mRNA in hepatopancreas was 6.61, 11.29 and 4.95 times as the lowest level of expression quantity in hemocytes, respectively. After PGN and Aeromonas hydrophila stimulation, the expression of these genes had significant difference in tissues of hepatopancreas, hemocytes and gill except for HcPGRP-L in hemocytes. These results suggested HcPGRP could involved in the immune recognition of H. cumingii and against gram-negative bacteria infection.

Clinical Significance of Joint Detection of CD44v6 and CD62P in Nasopharyngeal Carcinoma

Aim: The aim of this study was to investigate the expression and clinical prognostic significance of adhesion molecules in nasopharyngeal carcinoma (NPC) tissues and peripheral blood. Materials and Methods: Flow cytometry assays for the expression levels of CD44v6 and CD62P protein in peripheral blood and tissues from controls and NPC patients were performed. Clinical and pathological features were reported and analyzed, and a survival study was carried out. Results: The expression of CD44v6 and CD62P in NPC tissues and peripheral blood was higher than that of the control group (p < 0.05). Expression levels in peripheral blood of stage III/IV NPC patients was markedly higher than that of patients in stage I/II (p < 0.05), while it had no statistically significant difference in tissues (p > 0.05). The expression levels of CD44v6 and CD62P in the lymph gland metastasis and distant metastasis group were higher than groups without such metastasis (p < 0.05), and there was no statistical difference in NPC tissues (p > 0.05). The survival rates of NPC groups with low expression in the peripheral blood were higher than those of high-expression groups (p < 0.05). Conclusion: Joint detection of CD44v6 and CD62P in the peripheral blood or tissues of NPC patients has diagnostic and prognostic value as a marker of poor clinical outcome.

Important impacts of tissue selection and lipid extraction on ecological parameters derived from stable isotope ratios

Summary The nitrogen (δ15N) and carbon (δ13C) isotope ratios of animal tissues can help identify the composition of diets and open up a myriad of ecological applications. However, consumers do not ingest or assimilate all components of food items, and it is not well understood how sampling different tissues of sources and consumers may affect isotopic values ascribed, and thereby how such variation affects derived ecological measures. Utilizing a simple prey–predator feeding relationship in insects, we examined isotopic differences in soft, exoskeleton and whole tissues using samples with and without lipid extraction. As a derived ecological measure, we calculated trophic discrimination factors, changes in δ15N or δ13C between source and consumer, for the different prey–predator tissue combinations. Lipid extraction did not affect δ15N values, and we found significant tissue differences in δ15N that varied between prey and predator. Lipid extraction enriched δ13C values in most instances, and it was only after extraction of lipids that we observed consistent depletion of δ13C in exoskeleton relative to soft tissues in prey and predator. Isotopic differences between tissue types propagated marked variation in derived ecological parameters. Common sampling practice using whole tissue for prey and predator (whole/whole) resulted in a trophic discrimination factor of 0·48‰ for δ15N, compared with correct factors of 0·97‰ (soft/whole) and 2·18‰ (soft/soft) using prey soft tissue actually ingested by the predator. For δ13C, variation across discrimination factors was less, with whole/whole tissue of −0·14‰, whilst correct factors were −0·55‰ (soft/whole) and −0·04‰ (soft/soft). Our results indicate that tissue selection and preparation are important considerations for isotopic studies using arthropods. Lipid extraction is necessary to derive accurate δ13C values based on proteins, whilst consequences of tissue selection are likely context‐dependent: In poorly defined systems where sources are isotopically similar or have larger variance, our results indicate that tissue selection within sources is important to avoid significant error, whether estimating trophic positions or dietary proportions using mixing models. In such cases, we strongly recommend exclusion of source materials not assimilated in consumers.

Brain Characterization Using Normalized Quantitative Magnetic Resonance Imaging

ObjectivesTo present a method for generating reference maps of typical brain characteristics of groups of subjects using a novel combination of rapid quantitative Magnetic Resonance Imaging (qMRI) and brain normalization. The reference maps can be used to detect significant tissue differences in patients, both locally and globally.Materials and MethodsA rapid qMRI method was used to obtain the longitudinal relaxation rate (R1), the transverse relaxation rate (R2) and the proton density (PD). These three tissue properties were measured in the brains of 32 healthy subjects and in one patient diagnosed with Multiple Sclerosis (MS). The maps were normalized to a standard brain template using a linear affine registration. The differences of the mean value ofR1, R2 and PD of 31 healthy subjects in comparison to the oldest healthy subject and in comparison to an MS patient were calculated. Larger anatomical structures were characterized using a standard atlas. The vector sum of the normalized differences was used to show significant tissue differences.ResultsThe coefficient of variation of the reference maps was high at the edges of the brain and the ventricles, moderate in the cortical grey matter and low in white matter and the deep grey matter structures. The elderly subject mainly showed significantly lower R1 and R2 and higher PD values along all sulci. The MS patient showed significantly lower R1 and R2 and higher PD values at the edges of the ventricular system as well as throughout the periventricular white matter, at the internal and external capsules and at each of the MS lesions.ConclusionBrain normalization of rapid qMRI is a promising new method to generate reference maps of typical brain characteristics and to automatically detect deviating tissue properties in the brain.

Ischemia/reperfusion injury of porcine limbs after extracorporeal perfusion

BackgroundRevascularization of amputated extremities after prolonged ischemia is complicated by reperfusion injury. We assessed ischemia/reperfusion (I/R) injury of porcine extremities after prolonged preservation using extracorporeal circulation (ECC). MethodsForelimbs of 32 pigs were divided into four groups based on ischemia times: group I: 6 h, group II: 12 h, group III: 0 h plus replantation, and group IV: 6 h plus replantation. Limbs were perfused with autologous blood using ECC for 12 h except group II with only 5 h perfusion. Limbs from groups III and IV were heterotopically replanted with a 7-d follow-up. Contralateral limbs served as controls in all groups. Tissue, plasma, and serum were analyzed for the extent of I/R injury. ResultsNo significant differences in tissue wet/dry ratios were found within or between groups. This finding was confirmed by histology, except for an increased damage in group IV muscles compared with baseline (P = 0.016). Complement C3 deposition was only increased in group IV muscle (P = 0.031), group II nerves (P = 0.046), and group II vessels (P = 0.037). Group IV muscle and nerve tissues were the only ones with significant IgM antibody deposition (P = 0.031) at end of perfusion. Values were normal again after replantation. Reduced complement activity and elevated IL-6, IL-8, MCP-1, VEGF, PDGF-bb, bFGF, and complement split products were found during perfusion but were normal again after replantation. Staining for heparin sulfate proteoglycans and von Willebrand factor confirmed minimal activation of endothelial cells. ConclusionThe results demonstrate that prolonged limb preservation using ECC has minimal impact on I/R-induced tissue injury. Extracorporeal perfusion is a potential limb-preserving technique encouraging further studies for use in limb revascularization.

Systematic review: temporary stent placement for benign rupture or anastomotic leak of the oesophagus

Placement of self-expanding metal stents (SEMS) or plastic stents (SEPS) has emerged as a minimally invasive treatment option for benign oesophageal ruptures and leaks; however, it is not clear which stent type should be preferred. To assess clinical effectiveness and safety of treating benign oesophageal ruptures and anastomotic leaks with temporary placement of a stent with special emphasis on different stent designs. A pooled analysis was performed after searching PubMed and EMBASE databases for studies regarding placement of fully covered and partially covered SEMS (FSEMS and PSEMS) and SEPS for this indication. Data were pooled and evaluated for clinical outcome, complications and survival. Twenty-five studies, including 267 patients with complete follow-up on outcome, were identified. Clinical success was achieved in 85% of patients and was not different between stent types (SEPS 84%, FSEMS 85% and PSEMS 86%, P = 0.97). Time of stent placement was longest for SEPS (8 weeks) followed by FSEMS and PSEMS (both 6 weeks). In total, 65 (34%) patients had a stent-related complication. Stent migration occurred more often with SEPS [n = 47 (31%)] and FSEMS [n = 7 (26%)] than with PSEMS [n = 2 (12%), P ≤ 0.001], whereas there was no significant difference in tissue in- and overgrowth between PSEMS [12% vs. 7% (FSEMS) and 3% (SEPS), P = 0.68]. Although there is a lack of randomised controlled trials, it seems that covered stent placement for a period of 6-8 weeks is safe and effective for benign oesophageal ruptures and anastomotic leaks to heal. As efficacy between different stent types is not significantly different, stent choice should depend on expected risk of stent migration (self-expanding plastic stents and fully covered self-expanding metal stents) and, to a minor degree, on expected risk of tissue in- or overgrowth (partially covered self-expanding metal stents).

MRI of the neck at 3 Tesla using the periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) (BLADE) sequence compared with T2‐weighted fast spin‐echo sequence

To evaluate motion artifacts, tissue contrasts, and lesion detectability in the neck with the periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) (BLADE) technique. A total of 46 patients referred for MRI of the neck were included in a comparison of T2-weighted BLADE (T2W-BLADE) sequence and T2W fast spin-echo (T2W-FSE) sequence. All examinations were performed at 3T using the same parameters. Two observers evaluated unlabelled images for motion artifacts, the preferred image quality, and lesion detectability. Region of interest (ROI)-based quantitative measurements were performed to assess tissue contrasts. The frequency of occurrence of the different assessed artifacts and the lesion detectability was tested using McNemar's test. Tissue contrasts were compared using the Wilcoxon paired test. Reader agreement was assessed using kappa test. T2W-BLADE showed less ghosting and pulsation artifacts than T2W-FSE (P < 0.01). T2W-BLADE images were rated as better than or equal to T2W-FSE images in majority cases (93.5%; kappa = 0.64). There was not significant difference in tissue contrasts between T2W-BLADE and T2W-FSE. A total of 32 lesions were present in 32 patients and equally well seen on T2W-BLADE and T2W-FSE. T2W-BLADE can reduce motion artifacts and provide tissue contrasts and lesion detectability equivalent to T2W-FSE.

Interspecific competition enhances nitrogen fixation in an actinorhizal shrub

In forest understory restoration, the establishment of reintroduced species may be strongly linked to their ability to compete for belowground resources. In this study, we provide isotopic and morphological evidence for competition-induced increases in nitrogen fixation by Morella cerifera (L.) Small (wax myrtle) when planted with Pinus palustris Mill (longleaf pine). Compared to a competition-free treatment, we found no significant differences in tissue N concentrations for M. cerifera. However, 15N enrichment in leaves, stems and roots, as well as whole-plant values for nitrogen derived from fertilizer were significantly lower when the plants were subject to interspecific competition from P. palustris. Plants in the competition treatment also allocated a significantly greater percentage of belowground biomass to root nodules than those in the competition-free treatment (0.65 vs. 0.41%). This strongly suggests that M. cerifera is capable of upregulating nitrogen fixation in response to interspecific competition. This may help explain why M. cerifera outperformed non-nitrogen-fixing species reintroduced on the same site.

Growth, Oxidative Damage and Antioxidant Responses in Greengram (Vigna radiata L.) under Short‐term Salinity Stress and its Recovery

AbstractSpatio‐temporal differences under short‐term NaCl‐salinity (0, 50, 100, 150 mm l−1) stress for 24 h and post‐NaCl recovery after 24 h on the growth, water relations, ionic composition, proline and antioxidants of 12‐day‐old roots, stem and leaves of Vigna radiata were observed. Fresh and dry weight, relative water content and K+ ion decreased, whereas, Na+ ion and Na+/K+ ratio increased significantly in roots, stem and leaves. Post‐NaCl recovered roots, stem and leaves showed similar results with lower values. Chlorophyll and carotenoid pigments decreased significantly in the leaves. Peroxide and lipid peroxidation level increased significantly with higher ratio in stressed compared to recovered leaves. Ascorbate and proline content increased significantly with no significant change in glutathione content in stressed roots, stem and leaves. Significant decrease in protein content, SOD, CAT, POX, APX and GR activities was observed in roots with no significant change in stem and leaves. The recovered parts showed similar results except increased POX and GR activities showing a tissue‐specific response to NaCl‐salinity stress. Improved tolerance to salt stress may be accomplished by increased capacity of antioxidative defence system and by lower level of lipid peroxidation and improvement in the plant water status, activities of some of the antioxidants in the recovered parts suggest that significant tissue differences in response to salt stress in V. radiata is closely related to differences in the activities of antioxidants, ion and proline content.

PP111 Examination of the expression profiles of PGIS and TXS in NSCLC: Regulation of tumor cell growth and invasive potential

We have performed double-label immunofluorescence microscopy studies to evaluate the extent of co-localization of prostacyclin synthase (PGIS) and thromboxane synthase (TXS) with cyclooxygenase (COX)-1 and COX-2 in normal aortic endothelium. In dogs, COX-2 expression was found to be restricted to small foci of endothelial cells while COX-1, PGIS and TXS were widely distributed throughout the endothelium. Quantification of the total cross-sectioned aortic endothelium revealed a 6- to 7-fold greater expression of COX-1 relative to COX-2 (55 vs. 8%) and greater co-distribution of PGIS with COX-1 compared to COX-2 (19 vs. 3%). These results are in contrast to the extensive co-localization of PGIS and COX-2 in bronchiolar epithelium. In rat and human aortas, immunofluorescence studies also showed significant COX-1 and PGIS co-localization in the endothelium. Only minor focal COX-2 expression was detected in rat endothelium, similar to the dog, while COX-2 was not detected in human specimens. Inhibition studies in rats showed that selective COX-1 inhibition caused a marked reduction of 6-keto-PGF1α and TXB2 aortic tissue levels, while COX-2 inhibition had no significant effect, providing further evidence for a functionally larger contribution of COX-1 to the synthesis of prostacyclin and thromboxane in aortic tissue. The data suggest a major role for COX-1 in the production of both prostacyclin and thromboxane in normal aortic tissue. The extensive co-localization of PGIS and COX-2 in the lung also indicates significant tissue differences in the co-expression patterns of these two enzymes.

Double-label expression studies of prostacyclin synthase, thromboxane synthase and COX isoforms in normal aortic endothelium

We have performed double-label immunofluorescence microscopy studies to evaluate the extent of co-localization of prostacyclin synthase (PGIS) and thromboxane synthase (TXS) with cyclooxygenase (COX)-1 and COX-2 in normal aortic endothelium. In dogs, COX-2 expression was found to be restricted to small foci of endothelial cells while COX-1, PGIS and TXS were widely distributed throughout the endothelium. Quantification of the total cross-sectioned aortic endothelium revealed a 6- to 7-fold greater expression of COX-1 relative to COX-2 (55 vs. 8%) and greater co-distribution of PGIS with COX-1 compared to COX-2 (19 vs. 3%). These results are in contrast to the extensive co-localization of PGIS and COX-2 in bronchiolar epithelium. In rat and human aortas, immunofluorescence studies also showed significant COX-1 and PGIS co-localization in the endothelium. Only minor focal COX-2 expression was detected in rat endothelium, similar to the dog, while COX-2 was not detected in human specimens. Inhibition studies in rats showed that selective COX-1 inhibition caused a marked reduction of 6-keto-PGF 1α and TXB 2 aortic tissue levels, while COX-2 inhibition had no significant effect, providing further evidence for a functionally larger contribution of COX-1 to the synthesis of prostacyclin and thromboxane in aortic tissue. The data suggest a major role for COX-1 in the production of both prostacyclin and thromboxane in normal aortic tissue. The extensive co-localization of PGIS and COX-2 in the lung also indicates significant tissue differences in the co-expression patterns of these two enzymes.

Experimental Study of Fibrinolytic Factors and Its Inhibitors in Rabbits' Tissues Extract.

Objective: To study the expression character of fibrinolytic factors and its inhibitors in rabbits' tissues extract.Methods: Tissue plasminogen activator ( tPA ), Plasminogen activator inhibitor-1 ( PAI-1 ), Plasminogen ( Plg ), Plasmin ( Pl ) and α2 Plasmin inhibitor ( α2PI ) were measured by colorimetric assay.Results: The tissues extract in renal, small intestine, lung, brain and spleen showed strong fibrinolytic function, and expressed markedly high activity levels of tPA, Plg and Pl. But striped muscle, tongue and stomach expressed markedly high activity levels of PAI-1 and α2PI, and showed low fibrinolytic character. There were linear correlation between levels of tPA and PAI-1 ( r=−0.8076, P<0.01 ), Pl and αPI ( r=−0.3278, P<0.05 ), Plg and Pl ( r=0.6811, P<0.01 ) in tissues extract fibrinolytic targets. In relative tissues, renal cortex and renal marrow were significantly high level of tPA and low level of PAI-1, but levels of Plg and Pl in cortex renalis were higher than in renal marrow, the α 2PI level in renal marrow were higher than in renal cortex ( P<0.05~0.01 ). The levels of tPA, Plg and Pl in small intestine were higher than tin large intestine ( P<0.05~0.01 ), but the levels of PAI-1 and α 2PI in small intestine were markedly lower than in large intestine ( P<0.01 ). These indicated that fibrinolytic function in small intestine was stronger than in large intestine. Although the fibrinolytic function in muscle tissue was low, but the levels of tPA, Plg, and Pl in cardiac muscle were obviously higher than in striped muscles, and the levels of PAI-1 and α 2PI were obviously lower than in striped muscle ( P<0.05~0.01 ). These indicated that the fibrinolytic function in cardiac muscle were stronger than in the striped muscle.Conclusion: The fibrinolytic character existed significant difference in tissues, it has profound significance in the function of heamostasis and thrombosis and physiologic function in tissues.