Assessment of in vivo experiments: The newly synthesized porphyrin with proper light source enhanced effectiveness of PDT comparing to 5-ALA-mediated PDT

Publication date: June 2017
Source:Photodiagnosis and Photodynamic Therapy, Volume 18
Author(s): Kamil Jurczyszyn, Marta Woźniak, Krzysztof Symonowicz, Natasza Sprutta, Lechosław Latos-Grażyński, Piotr Ziółkowski, Yurij Ivonyak, Piotr Tuchowski, Witold Trzeciakowski
BackgroundThe search for new photosensitizers for application in photodynamic therapy has quite a long history. In the past, a large number of potent photosensitizers were used in both basic and clinical studies; however, only a few turned out to be effective and safe.MethodsIn the present study, two compounds were used: 5-aminolevulinic acid in two formulations (free and liposomal), and the newly synthesized porphyrin, 5,10,15,20-tetra-p-tolyl-22,24-dithiadibenzocarbaporphyrin, termed DTDB. Two different light sources, a halogen lamp (wavelength 450+/−20nm) and a diode laser (wavelength 450nm), were used to sensitize the compounds. The entire experiment was performed on mice bearing mouse mammary carcinoma, 4T1.ResultsThe results showed that the DTDB-PDT applied by means of a laser proved to be most effective and caused the 83.3% necrosis of treated tumors. The overall effect of laser PDT was more potent than that of the halogen lamp-mediated PDT.ConclusionsIn the present study, we would like to show that modifications of porphyrins lead to an increase in the effectiveness of PDT and that this effect could also be potentiated by using a proper light source.



http://ift.tt/2mfr3ez

Comparison of photoinactivation of T. rubrum by new methylene blue (NMB) and indocyanine green (EmunDo®)

Publication date: June 2017
Source:Photodiagnosis and Photodynamic Therapy, Volume 18
Author(s): Reza Fekrazad, Arash Poorsattar Bejeh Mir, Mina Kahyaie Aghdam, Vadood Ghasemi Barghi
BackgroundSuperficial mycotic skin infections which are predominantly caused by Trichophyton rubrum, poorly responsd to conventional therapies. A great amount of attention has focused on finding more effective treatments. The current work is aimed to compare the effectiveness of phoinactivation of Trichophyton rubrum by two relatively new photosensitizers: a phenothiazinium dye(New methylene blue) and Indocyanine green (EmunDo^®).Materials and methodsA Final inoculum of T. rubrum which corresponded to 10⁶ colony forming unit per milliliter (CFUml⁻¹) was prepared. Antimicrobial Photodynamic treatment (aPDT) of T. rubrum was carried out by either EmunDo^® (1mg/ml, Infra-red laser (IRL, λ=810nm, Energy Density 55J/cm²)) or NMB (10μM, Red laser (RL), λ=630nm, Energy Density of 5J/cm²). The suspensions thereafter were subcultured on Sabouraud dextrose agar (SDA) and were counted on due time. based on colony-forming unit per milliliter (CFU/ml).ResultsaPDT with either EmunDo^® (E) or NMB (N) considerably diminished the viability of inoculated T. rubrum with respective reduction of 0.64 log and 0.4 log compared to the control group (P<0.001). No significant difference was found between two laser only groups (P=0.79) and two aPDT groups (P=0.73), however significant reduction of T. rubrum in red laser only group (P=0.04) and EmunDo^® only group (P=0.04) was found as compared to the control group (P<0.05).ConclusionThe study provides evidence regarding satisfactory photodynamic inactivation of T. rubrum with EmunDo^® or NMB as photosensitizers. Irradiation by only red laser source was found superior to only infra-red laser source. Dark toxicity of EmunDo^® was more successful than new methylene blue dye.



http://ift.tt/2mVuHHJ

A quantitative study of in vivo protoporphyrin IX fluorescence build up during occlusive treatment phases

Publication date: June 2017
Source:Photodiagnosis and Photodynamic Therapy, Volume 18
Author(s): C Louise Campbell, C Tom A Brown, Kenneth Wood, Ana Gabriela Salvio, Natalia M Inada, Vanderlei S Bagnato, Harry Moseley
BackgroundTopical photodynamic therapy (PDT) is a non-invasive light based therapy used to treat non-melanoma skin cancer (NMSC) and dysplasia. During PDT, the light sensitive molecule protoporphyrin IX (PpIX) is activated, resulting in the production of singlet oxygen, which subsequently leads to cell death. PpIX is metabolised from a topically applied pro-drug and the strong fluorescence signal associated with PpIX can be utilised as an indicator of the amount of PpIX present within the tumour tissue. In this work we measure the build up PpIX during the occlusive treatment phase and investigate how the PpIX production rate is affected by different lesion and patient characteristics.MethodsFluorescence measurements were used to investigate the build up of PpIX within the tumour tissue during the 3h long occlusive treatment prior to irradiation. The study included in vivo measurements of 38 lesions from 38 individual patients. Actinic keratosis (AK) and basal cell carcinoma (BCC) were the lesion types included in this study. The resulting data from the study was analysed using generalised linear mixed effects models.ResultsIt was found that the surface fluorescence signal linearly increased with occlusive treatment time. The predictive models suggest that there is a significant difference in PpIX production between lesion location, however no significant difference is demonstrated between different lesion types, gender and skin type.ConclusionsThe study extends and supports previous knowledge of PpIX production during the occlusive treatment phase.



http://ift.tt/2mfwjiv

Influence of iron oxide nanoparticles (Fe3O4) on erythrocyte photohemolysis via photofrin and Rose Bengal sensitization

Publication date: June 2017
Source:Photodiagnosis and Photodynamic Therapy, Volume 18
Author(s): M-Ali H. Al-Akhras, Khaled Aljarrah, Borhan Albiss, Duaa Al-Khalili
BackgroundIron oxide (Fe3O4) nanoparticles (IO-NP) were recently employed in medical applications as a diagnostic tool and drug carrier. Photofrin (PF) is a photosensitizer that clinically is used in Photodynamic therapy (PDT).Study designThe photosensitivity of PF and Rose Bengal (RB) mixed with (IO-NP) on red blood cells (RBCs) lysis was investigated. Second, Photohemolysis for post-irradiation (delayed) and during irradiation (continuous) with PF, RB and IO-NP combinations at different concentrations was investigated. Third, the photohemolysis rate, relative lysis steepness and power-concentration dependant parameter were evaluated by modeling and fitting the data using Gompertz function and power law.MethodsRBCs were isolated from healthy male human volunteer. Washed cells (7.86×10⁶ cells/mm³) were incubated with PF only or with IO-NP for 45min at 37°C then irradiated to a range of temperatures (4–41°C). CPH results were recorded and evaluated using Gompertz function.ResultsThe relative steepness of the photohemolysis curves was approximately independent on light dose for delayed irradiation. The presence of IO-NP increases the rupturing time for 50% of the RBCs. Photohemolysis rate for delayed irradiation using the power law, led to 1.7 and 2.3 power dependence, respectively, for PF only and PF mixed with IO-NP. The power dependence of continuous irradiation measurements showed inverse proportionality for different concentrations of IO-NP combined with 2μg/ml PF concentration and 1.5μg/ml for RB concentration.ConclusionPhotosensitization of RBC with PF or RB mixed with IO-NP inhibited rupturing erythrocyte membrane and therefore a consideration should be taken against their combination in clinical applications.



http://ift.tt/2mVpjVd

ALA—Photodynamic treatment in Lichen sclerosus—clinical and immunological outcome focusing on the assesment of antinuclear antibodies

Publication date: June 2017
Source:Photodiagnosis and Photodynamic Therapy, Volume 18
Author(s): Anita Olejek, Iwona Gabriel, Anna Bilska-Janosik, Iwona Kozak-Darmas, Aleksandra Kawczyk-Krupka
BackgroundLichen sclerosus (LS) is a difficult to treat, often relapsing disease with unknown background. Autoimmune diseases also coexist with LS. Over recent years photodynamic therapy (PDT) has been shown to be a noninvasive and successful therapeutic approach for the effective treatment of many conditions. However, the change of immune status of the patients based on ANA antibodies has not been yet reported. Our aim was to observe the clinical response followed by possible changes in autoimmune antibodies levels before and after PDT for LS.Material and MethodsWe enrolled 100 women with Lichen sclerosus with or without a concomitant autoimmune disease. All patients received 10 cycles of PDT (65 treated with DIOMED Light, 35 with PhotoDYN Light). We assessed autoimmune antibodies before and after PDT in addition to the clinical response evaluation.Two-year prospective controlled before-and-after study.ResultsFollowing PDT, patients showed a significant attenuation in symptoms' intensity (itching, pruritus, vulvar discomfort). After therapy 41% of patients had partial response, 51% of patients had no symptoms and 8% had persistent or worsened symptoms. The most frequent autoimmune disease were thyroid disorders, followed by vitiligo and arthritis. 57% patients with an additional autoimmune disease before PDT had ANA antibodies. The mean level of ANA in this group diminished significantly after PDT treatment (261.74 IU/ml before vs. 123.20 IU/ml after treatment).ConclusionBased on our results, we assume that PDT may influence the immune status of patients with Lichen sclerosus.



http://ift.tt/2n1E1vx

Photodynamic therapy enhances the efficacy of gene-directed enzyme prodrug therapy

Publication date: June 2017
Source:Photodiagnosis and Photodynamic Therapy, Volume 18
Author(s): Catherine Christie, Aftin Pomeroy, Rohit Nair, Kristian Berg, Henry Hirschberg
IntroductionGene-directed enzyme prodrug therapy (GDEPT) employing the cytosine deaminase (CD) gene, which encodes an enzyme that converts the nontoxic agent 5-fluorocytosine (5-FC) into the chemotherapeutic drug 5-fluorouracil (5-FU), has shown promise both in experimental animals and in clinical trials. Nevertheless, with the transfection systems available presently the percentage of tumor cells incorporating the desired gene is usually too low for successful therapy. We have examined the ability of photodynamic therapy (PDT) to enhance the efficacy of the metabolites, converted from 5-FC by CD gene transfected rat glioma cells.MethodsHybrid tumor cell spheroids consisting of CD poitive and CD negative F98 glioma cells in varying ratios were used as in vitro tumor models. PDT was performed with the photosensitizer AlPcS2a and λ=670nm laser irradiance, both before and after confrontation with 5-FC.ResultsPDT increased the toxicity of 5-FU either as pure drug or derived from monolayers of CD positive cells chalanged with 5-FC. PDT in combination with 5-FC resulted in a significantly enhanced inhibition of hybrid spheroid growth compared to non light treated controls. This was the case even at tumor to producer cell ratios as high as 40:1.ConclusionThe results of the present study show that GDEPT and PDT interact in a synergistic manner over a range of prodrug concentration and tumor to transfected cell ratios. The degree of synergy was significant regardless if PDT treatment was given before or after 5-FC administration. The highest degree of interaction was observed though, when PDT was delivered prior to prodrug exposure.



http://ift.tt/2n1KM0o

In silico identification of a therapeutic target for photo-activated disinfection with indocyanine green: Modeling and virtual screening analysis of Arg-gingipain from Porphyromonas gingivalis

Publication date: June 2017
Source:Photodiagnosis and Photodynamic Therapy, Volume 18
Author(s): Maryam Pourhajibagher, Abbas Bahador
BackgroundPorphyromonas gingivalis is a momentous bacterial etiological agent associated with periodontitis, peri-implantitis as well as endodontic infections. The potential advantage of Photo-activated disinfection (PAD) as a promising novel approach is the choice of a suitable target site, specific photosensitizer, and wavelength of light for delivery of the light from source to target. Since Arg-gingipain is a cysteine proteinase that is involved in the virulence of P. gingivalis, it was evaluated as a target site for PAD with indocyanine green (ICG) as a photosensitizer.MethodsIn this study, we used a range of in silico strategies, bioinformatics tools, biological databases, and computer simulation molecular modeling to evaluate the capacity of Arg-gingipain.ResultsThe predicted structure of Arg-gingipain indicated that it is located outside the cell and has nine domains and 17 ligands, including two calcium ions and three sodium ions with positive charges which can be a site of interaction for anionic ICG.ConclusionBased on the results of this study, anionic ICG desires to bind and interact with residues of Arg-gingipain during PAD as a main site to enhance the yield of treatment of endo-periodontal lesions.



http://ift.tt/2mftL42

Real-time light dosimetry for intra-cavity photodynamic therapy: Application for pleural mesothelioma treatment

Publication date: June 2017
Source:Photodiagnosis and Photodynamic Therapy, Volume 18
Author(s): Nacim Betrouni, Camille Munck, Wael Bensoltana, Grégory Baert, Anne-Sophie Dewalle-Vignion, Arnaud Scherpereel, Serge Mordon
Complete and homogeneous illumination of the target is necessary for the success of a photodynamic therapy (PDT) procedure. In most applications, light dosimetry is done using detectors placed at strategic locations of the target. In this study we propose a novel approach based on the combination of light distribution modeling with spatial localization of the light applicator for real time estimation and display of the applied dose on medical images. The feasibility approach is demonstrated for intrapleural PDT of malignant pleural mesothelioma.



http://ift.tt/2mVuILD

Liposomal delivery of ferrous chlorophyllin: A novel third generation photosensitizer for in vitro PDT of melanoma

Publication date: June 2017
Source:Photodiagnosis and Photodynamic Therapy, Volume 18
Author(s): Iman Gomaa, Aya Sebak, Nagia Afifi, Mahmoud Abdel-Kader
BackgroundCutaneous melanoma (CM) has substantially increased among Caucasian populations in the past few decades. This increased the number of CM deaths throughout the world. Pigmentation of melanoma reduces the efficacy of photodynamic therapy (PDT). Third generation photosensitizers (PSs) are characterized by improved targeting to the diseased tissue and reduced systemic side effects. This study is directed towards synthesis and characterization of liposomes encapsulating sodium ferrous chlorophyllin (Fe-CHL) and assessing its efficacy as a PS in PDT of melanoma.MethodsPhenylthiourea (PTU) was used as a melanin synthesis inhibitor. PDT has been applied on de-pigmented melanoma cells using liposomes-encapsulated Fe-CHL. Cell death mechanisms after PDT were evaluated.ResultsTreatment of melanoma cells with 200μM of PTU for 48h provided 49.9% melanin inhibition without significant cytotoxicity. Transmission electron microscope (TEM) results proved an increase in the cellular uptake of liposomes by increasing incubation period from 6 to 24h via endocytosis with preferential accumulation in the mitochondria and the nucleus. Following de-pigmentation, PDT was applied resulting in LC50 of 18.20 and 1.77μM after 24 and 48h incubation with liposomes-encapsulated Fe-CHL respectively and exposure to 56.2J/cm² monochromatic red laser of wavelength of 652nm. Mechanism of cell death of Fe-CHL mediated PDT was found to be a combination of both apoptosis and necrosis.ConclusionsLiposomes could be efficiently employed as a potential sustained release delivery system in the Fe-CHL-mediated PDT of de-pigmented melanoma.

Graphical abstract

http://ift.tt/2mfCMKf

Risk factors for overweight and obesity in children aged 2–6 years

Journal Name: Journal of Pediatric Endocrinology and Metabolism
Issue: Ahead of print


http://ift.tt/2n9EZpJ

Anonymity and Electronics

Publication date: Available online 18 March 2017
Source:Academic Radiology
Author(s): Teresa Chapman, Janet R. Reid, Erin E. O'Conner
Rationale and ObjectivesDiagnostic radiology resident assessment has evolved from a traditional oral examination to computerized testing. Teaching faculty struggle to reconcile the differences between traditional teaching methods and residents' new preferences for computerized testing models generated by new examination styles. We aim to summarize the collective experiences of senior residents at three different teaching hospitals who participated in case review sessions using a computer-based, interactive, anonymous teaching tool, rather than the Socratic method.Materials and MethodsFeedback was collected from radiology residents following participation in a senior resident case review session using Nearpod, which allows residents to anonymously respond to the teaching material.ResultsSubjective resident feedback was uniformly enthusiastic. Ninety percent of residents favor a case-based board review incorporating multiple-choice questions, and 94% favor an anonymous response system.ConclusionsNearpod allows for inclusion of multiple-choice questions while also providing direct feedback to the teaching faculty, helping to direct the instruction and clarify residents' gaps in knowledge before the Core Examination.



http://ift.tt/2nlWeVz

The rationale of indoleamine 2,3-dioxygenase inhibition for cancer therapy

Publication date: May 2017
Source:European Journal of Cancer, Volume 76
Author(s): Lieve Brochez, Ines Chevolet, Vibeke Kruse
Indoleamine 2,3-dioxygenase (IDO, also referred to as IDO1) has been demonstrated to be a normal endogenous mechanism of acquired peripheral immune tolerance in vivo.In the field of oncology, IDO expression and/or activity has been observed in several cancer types and has usually been associated with negative prognostic factors and worse outcome measures.This manuscript reviews current available data on the role of IDO in cancer and the current results obtained with IDO inhibition, both in animal models and in phase 1 and 2 clinical trials in humans. Preliminary results with IDO inhibitors, usually combined with other anti-cancer drugs, seem encouraging. Further studies are needed to clarify the conditions in which IDO inhibitors can be of value as an anti-cancer strategy. In addition, further research should address whether the expression of IDO in tissue or blood can be a marker to select patients who can benefit most from IDO inhibition.



http://ift.tt/2mVn97U

Biological mechanisms of immune escape and implications for immunotherapy in head and neck squamous cell carcinoma

Publication date: May 2017
Source:European Journal of Cancer, Volume 76
Author(s): Jennifer D. Moy, Jessica M. Moskovitz, Robert L. Ferris
Head and neck squamous cell carcinoma (HNSCC) is an aggressive malignancy with high morbidity and mortality. Despite advances in cytotoxic therapies and surgical techniques, overall survival (OS) has not improved over the past few decades. This emphasises the need for intense investigation into novel therapies with good tumour control and minimal toxicity. Cancer immunotherapy has led this endeavour, attempting to improve tumour recognition and expand immune responses against tumour cells. While various forms of HNSCC immunotherapy are in preclinical trials, the most promising direction thus far has been with monoclonal antibodies (mAbs), targeting growth factor and immune checkpoint receptors. Preclinical and early phase trials have shown unprecedented efficacy with minimal adverse effects. This article will review biological mechanisms of immune escape and implications for immunotherapy in HNSCC.



http://ift.tt/2mfkx7R

Impaired quality of life in patients with treated acromegaly despite long-term biochemically stable disease: results from a 5-year prospective study

Abstract

Objective

Patients with acromegaly demonstrate impaired quality of life (QoL), but data on long-term QoL changes in treated acromegaly are limited. This study evaluates and identifies factors that influence QoL in patients with long-term biochemical remission.

Design

The study consists of a cross-sectional arm comparing QoL between patients with treated and controlled acromegaly and healthy controls; and a longitudinal arm assessing QoL changes in patients with biochemically stable disease during 5.7±0.6yrs of follow-up.

Patients

58 patients and 116 matched controls were recruited for the cross-sectional arm; 28 patients completed the longitudinal arm.

Measurements

Three generic questionnaires [Psychological General Well-Being Schedule (PGWBS), 36-item Short-Form (SF-36), EuroQoL (EQ-5D)] and the disease-specific acromegaly QoL questionnaire (AcroQoL) were applied.

Results

QoL assessment was performed 11.6±8.2yrs following diagnosis and treatment of acromegaly. Patients with treated acromegaly had lower QoL scores compared with controls in all questionnaires with the exception of the PGWBS "Anxiety" subscale. The AcroQoL "Appearance" subscale and the "physical function" subscales of the remaining questionnaires were the most underscored domains. No difference in the total and subscale scores of all questionnaires was observed between baseline and follow-up, with the exception of the SF-36 "Physical Function", where a decline was found (58.5±24.7% vs. 43.1±31.1%; p=0.002). However, after adjusting for covariates, no significant change in any of the QoL scores was seen. Duration of IGF-1/GH control was positively correlated with QoL scores in most questionnaires at baseline, whereas use of GH lowering therapy at the time of QoL assessment was a negative predictive factor of QoL.

Conclusions

Patients with biochemically controlled acromegaly demonstrate impaired QoL, which persists despite long-term disease control. This primarily consists of impaired physical function and secondly of impaired psycho-social well-being. Duration of biochemical disease control and current use of GH lowering therapy were the predominant factors determining patients' QoL.

This article is protected by copyright. All rights reserved.

http://ift.tt/2n1Gt55

The effects of DASH diet on weight loss, anti-Müllerian hormone and metabolic profiles in women with polycystic ovary syndrome: a randomized clinical trial

Summary

Objective

This study was designed to evaluate the effects of the Dietary Approaches to Stop Hypertension (DASH diet) on weight loss, anti-Müllerian hormone (AMH) and metabolic profiles in women with polycystic ovary syndrome (PCOS).

Design, Patients and Measurements

A randomized controlled clinical trial was conducted among 60 overweight or obese patients with PCOS. Patients were randomly assigned to receive either low-calorie DASH (N=30) or control diet (N=30) for 12 weeks. The DASH and control diets were consisted of 52-55% carbohydrates, 16-18% proteins and 30% total fats; however, the DASH diet was designed to be rich in fruits, vegetables, whole grains, low-fat dairy products, cholesterol and refined grains. Both diets were equicaloric.

Results

Adherence to the DASH diet, compared to the control diet, resulted in a significant decrease in BMI (-1.6±0.5 vs. -1.2±0.7 kg/m², P=0.02). Significant decreases in AMH (-1.1±3.1 vs. +0.3±0.7 ng/mL, P=0.01), insulin (-25.2±51.0 vs. -1.2±28.8 pmol/L, P=0.02), homeostasis model of assessment-estimated insulin resistance (-0.9±2.0 vs. -0.1±1.0, P=0.02), free androgen index (FAI) (-0.03±0.09 vs. +0.06±0.21, P=0.02) and malondialdehyde (MDA) levels (-0.5±0.4 vs. +0.2±0.3 μmol/L, P<0.001), and significant increases in quantitative insulin sensitivity check index (+0.01±0.03 vs. -0.004±0.01, P=0.02), sex hormone-binding globulin (SHBG) (+3.7±8.5 vs. -1.5±7.2 nmol/L, P=0.01) and nitric oxide (NO) (+9.0±4.9 vs. +0.6±2.3 μmol/L, P<0.001) were also seen in the DASH group compared with the control group .

Conclusions

Adherence to the DASH diet for 12 weeks among PCOS women had beneficial effects on BMI, AMH, insulin metabolism, SHBG, FAI, NO and MDA levels.

This article is protected by copyright. All rights reserved.

http://ift.tt/2mHnJ8g

Biological predictors of radiosensitivity in head and neck squamous cell carcinoma

Abstract

Objectives

The aim of this study is to investigate the influence of prognostic biomarkers on radiosensitivity and survival of advanced head and neck squamous cell carcinomas treated by primary (chemo)radiation.

Material and methods

The clinicopathological data and immunohistochemical staining of p16, c-Met, survivin, PD-1, and PD-L1 of 82 primarily (chemo)irradiated patients with head and neck squamous cell carcinoma were analyzed. Associations with local and locoregional radiation response, overall survival (OS), disease-free (DFS), and disease-specific survival (DSS) were assessed.

Results

Complete tumor response was associated with increased patient age (p = 0.007), N0-status (p = 0.022), M0-status (p = 0.007), and p16-positivity (p = 0.022). High PD-L1 was associated with M0-status (p = 0.026) and indicated tumor response to irradiation (p = 0.057); survivin expression showed higher rates of response failure (p = 0.073). Low PD-1 was associated with increased T-stage (p = 0.029) and local recurrence (p = 0.014). High PD-1 was strongly correlated with PD-L1-positive tumor infiltrating lymphocytes (p < 0.001). Low PD-L1 showed a significant correlation with high c-Met expression (p = 0.01). Significant predictors for unfavorable univariate survival were incomplete tumor response (DSS, p < 0.001), single radiotherapy (DSS, p = 0.002), M1-status (DSS, p < 0.001), decreased radiation dose (DSS, p = 0.014), high survivin (DSS, p = 0.045), and high c-Met (OS, p < 0.05). Survivin and c-Met also showed prognostic significance in multivariate survival analysis.

Conclusions

P16 and PD-L1 indicate radiosensitivity, whereas survivin and c-Met implicate radioresistance in primarily (chemo)irradiated head and neck squamous cell carcinomas. The role of the PD-1/PD-L1 immune checkpoints in radiation response and survival merits further investigation.

Clinical relevance

The findings may improve patient-specific therapy according to individual tumor characteristics.

http://ift.tt/2mDBwMh

Exogenous application of plant growth regulators (PGRs) induces chilling tolerance in short-duration hybrid maize

Abstract

Chilling stress hampers the optimal performance of maize under field conditions precipitously by inducing oxidative stress. To confer the damaging effects of chilling stress, the present study aimed to investigate the effects of some natural and synthetic plant growth regulators, i.e., salicylic acid (SA), thiourea (TU), sorghum water extract (SWE), and moringa leaf extract (MLE) on chilling stress tolerance in autumn maize hybrid. Foliar application of growth regulators at low concentrations was carried out at six leaf (V6) and tasseling stages. An increase in crop growth rate (CGR), leaf area index (LAI), leaf area duration (LAD), plant height (PH), grain yield (GY), and total dry matter accumulation (TDM) was observed in exogenously applied plants as compared to control. In addition, improved physio-biochemical, phenological, and grain nutritional quality attributes were noticed in foliar-treated maize plots as compared to non-treated ones. SA-treated plants reduced 20% electrolyte leakage in cell membrane against control. MLE and SA were proved best in improving total phenolic, relative water (19–23%), and chlorophyll contents among other applications. A similar trend was found for photosynthetic and transpiration rates, whereas MLE and SWE were found better in improving CGR, LAI, LAD, TDM, PH, GY, grains per cob, 1000 grain weight, and biological yield among all treatments including control. TU and MLE have significantly reduced the duration in phenological events of crop at the reproductive stage. MLE, TU, and SA also improved the grain protein, oil, and starch contents as compared to control. Enhanced crop water productivity was also observed in MLE-treated plants. Economic analysis suggested that MLE and SA applications were more economical in inducing chilling stress tolerance under field conditions. Although eliciting behavior of all growth regulators improved morpho-physiological attributes against suboptimal temperature stress conditions, MLE and SA acted as leading agents which proved to be better stress alleviators by improving plant physio-biochemical attributes and maize growth.

http://ift.tt/2mGLL3g

Toxic elements and bio-metals in Cantharellus mushrooms from Poland and China

Abstract

Data on multi-trace element composition and content relationships have been obtained for Cantharellus cibarius, C. tubaeformis, and C. minor mushrooms from Poland and China by inductive coupled plasma–dynamic reaction cell–mass spectroscopy. There is no previous data published on As, Li, V, Tl, and U in chanterelles from Poland and on Ba, Co, Cr, Ni, Rb, and Sr in chanterelles from China. The results implied a role of the soil background geochemistry at the collection site with the occurrence of Ag, As, Ba, Cr, Cs, Li, Mn, Pb, Rb, Sr, U, and V in the fruiting bodies. Both geogenic Cd and anthropogenic Cd can contribute in load of this element in chanterelles from the Świetokrzyskie Mts. region in Poland, while geogenic source can be highly dominant in the background areas of Yunnan. An essentiality of Cu and Zn and effort by mushroom to maintain their physiological regulation could be reflected by data for Cantharellus mushrooms from both regions of the world, but its geogenic source (and possibly anthropogenic) can matter also in the region of the Świetokrzyskie Mountains in Poland. The elements Co, Ni, and Tl were at the same order of magnitude in contents in C. cibarius in Poland and Yunnan, China. C. tubaeformis differed from C. cibarius by a lower content of correlated Co, Ni, and Zn. Soil which is polymetallic and highly weathered in Yunnan can be suggested as a natural geogenic source of greater concentrations of As, Ba, Cr, Li, Pb, Sr, U, and V in the chanterelles there while lower of Mn and Rb, when related to chanterelles in Poland. A difference in Cs content between the sites can be attributed as an effect of the ¹³⁷Cs release from the Chernobyl accident, in which Poland was much more affected than Yunnan, where deposition was negligible.

http://ift.tt/2n0PD1Q

Biodegradation of 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47) by Phanerochaete chrysosporium in the presence of Cd 2+

Abstract

Aerobic biodegradation of 2,2′,4,4′-tetrabrominated diphenyl ether (BDE-47) by Phanerochaete chrysosporium in the presence of Cd²⁺ was investigated in this study. The results showed that P. chrysosporium could effectively degrade BDE-47, and its extracellular enzyme played an important role in the process of decomposition. BDE-47 biodegradation by fungi was more tolerant than extracellular enzyme in the presence of Cd²⁺. Also, both of the activity of two typical enzymes, MnP and LiP, descended with ascended Cd²⁺ concentration. Based on the four mono-hydroxylated PBDEs (5-OH-BDE-47, 4′-OH-BDE-17, 6-OH-BDE-47, and 2′-OH-BDE-28) and two bromophenols (2,4-DBP, 4-BP) detected, three possible degradation pathways were proposed, inferring that BDE-47 was more easily to transform via hydroxylation. With addition of Cd²⁺, the types of degradation products did not change, merely a variation of the content of these products observed. Meanwhile, the major metabolites of BDE-47, bromophenol compounds, have been found to be transformed or even mineralized by P. chrysosporium quickly, which also helped better explain why the amounts of BDE-47 decomposed did not match with that of the metabolites detected.

http://ift.tt/2mGLJZc

Changes and relations of photosynthesis and iron cycling in anoxic paddy soil amended with high concentrations of sulfate

Abstract

Sulfate contamination is an increasingly serious environmental problem related to microbial reduction processes in anoxic paddy soil. This study revealed the changes and interrelations of ferric iron [Fe(III)] reduction, ferrous iron [Fe(II)] oxidation, and oxygenic photosynthesis in an anoxic paddy soil (Fe-accumuli-Stagnic Anthrosols) amended with a range of high sulfate concentrations. Soil slurries mixed with 0 (control), 50, 100, 200, and 400 mmol kg⁻¹ Na₂SO₄ were incubated anaerobically under dark and light conditions. The changes in chlorophyll a (Chl a), Fe(II), pH levels, and the chlorophyll absorption spectrum were determined over a 42-day period. Fe(II) concentrations increased with the addition of sulfate under dark conditions, while Fe(III) reduction potential was enhanced by increasing sulfate addition. The effect of light on Fe(II) concentration was observed after 16 days of incubation, when Fe(II) started to decrease markedly in the control. The decrease in Fe(II) slowed with increasing sulfate addition. The concentrations of Chl a increased in all treatments after 16 days of incubation under light conditions. There was a reduction in Chl a accumulation with increasing sulfate at the same incubation time. The absorption peaks of chlorophyll remained shorter than the 700-nm wavelength throughout the incubation period. The pH of all treatments decreased in the first week and then increased thereafter. The pH increased with sulfate addition and light conditions. In conclusion, contamination with high concentrations of sulfate could accelerate Fe(III) reduction while inhibiting oxygenic photosynthesis, which correspondingly slows chemical Fe(II) oxidation in an anoxic paddy soil.

http://ift.tt/2n13x3Q